A major winter storm is going to affect the chicagoland area starting late weds night and lasting all the way into friday. This will only add to the harsh winter we have had already and most likely push my winter snow total above 30" and its only early january.
Lets start things off by looking at a WV loop.
http://weather.cod.edu/loops/US-WV.loop.html
Currently, our shortwave, or alberta clipper is moving southeast across canada and will be in north dakota by tomorrow morning/afternoon. from there it will continue to slide southeast into IA and make a turn more to the east as it moves across IL/IN. This is a very impressive storm system is going to have a ton of dynamics with it. One of the problems or things that is going to hamper even more snow accumulations is this thing is going to be completely cut off from any gulf moisture due to a high pressure out ahead of it.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_ten_024l.gif
The strong dynamics plus the high snow ratios, possibly nearing 30:1, due to the artic air associated with this system, will help off set the moisture problems and still will allow for significant snow accumulations.
LOT has all of the chicago area under a winter storm watch starting tomorrow night and going until thursday evening for snow accumulations of 7-9". another problem that is going to be a factor is the wind on the backside of this storm. there could be gusts to 25-30mph. And with 6" of very fluffy snow, there is going to be alot of blowing and drifting of the snow which will create ground blizzards, espcially out in rural area.
another impressive point is that there is going to be a fairly deep DGZ which will allow for really good snow growth to occur and with such impressive dynamics, wouldn't be suprised to have some convective snow due to the good lapse rates that will be in place.
right now I think the heaviest snow totals will be along and north of the track of the H7 low, which looks to be from around cedar rapids, IA to chicago where lake enhancement should aid in higher totals as well as the possible lake effect snow on our side of the lake thursday night and friday. I know some other people and I have been talking about the LES setup on 1/22/05 on the backside of strong clipper that brought widespred lake effect snow to the chicagoland area and gave me the most I have got from LE. Still hard to say exactly what will happen but I think someone in IN, west of the friday night/saturday event, could get rick rolled from a nasty band.
most models are spitting out around .35"-.45" liquid eqv. and with 20-30:1, you can do the math. for now I am going to go with 6-10" across all of the area with more the closer you get to the lake as lake enhancement will have more of an effect. wouldn't be suprised to see some totals near a foot close to the lake and down towards the southern tip of lake michigan near the IL/IN border.
will most likely do another post tomorrow afternoon or evening. new 0z NAM putting out .40"-.50" QPF with a nice lake band on the backside.
http://www.twisterdata.com/index.php?prog=forecast&model=NAM&grid=221&model_yyyy=2010&model_mm=01&model_dd=06&model_init_hh=00&fhour=57¶meter=PCPIN&level=48&unit=HR&maximize=n&mode=singlemap&sounding=n&output=image&archive=false
Matt
Tuesday, January 5, 2010
Monday, December 7, 2009
here comes the big daddy!!
well looking at a WV loop our upper level wave is continuing to dig southeast across CA and will soon kick out and start moving east as now the main jet energy is now at the base of the trof. currently, the best pressure falls are across southern CA where as of 0z the sfc low sitting over southeast NV right now. with the best pressure falls down there you could wonder if it will track southeast towards the Grand Canyon across northern AZ and NM could verify instead of going through UT and CO.
ICT has been saying all day that the jet energy with this wave has been underdone by the models which could mean it could dig further south then progged. WV imagery looks to be supporting them for the time being. either way, an area of low pressure will emerge tomorrow and probably end up riding east across northern OK and then turning northeast going through MO to between quincy IL and STL to somewhere between gary and south bend, IN.
snow should begin here in the morning as the WAA kicks in and gets thrown over some pretty cold air. it will get heavier as the afternoon goes on and there could be some impressive rates nearing a 1"/hr in some spots. what happens next will be key. if the low can track alittle bit further southeast then most areas should stay snow due to alot of insentropic lift and some intense precip rates with a mix possible down near joliet and kankakee. I think it will come down to a nowcast event tomorrow but right now for amounts. I will go with a foot possible out by RFD. 6-9" from sugar grove to the elgin/streamwood area to 3-6 for the plainfield/bolingbrook area tampering to 2-4 for MDW. subject to change and will try to do another post late tonight after the 0z runs or in the morning.
all in all. a major winter storm is going to affect the area beginning the morning and lasting to weds afternoon with wind gusts nearing 45mph and creating possible blizzard conditions for a time weds morning.
Matt
ICT has been saying all day that the jet energy with this wave has been underdone by the models which could mean it could dig further south then progged. WV imagery looks to be supporting them for the time being. either way, an area of low pressure will emerge tomorrow and probably end up riding east across northern OK and then turning northeast going through MO to between quincy IL and STL to somewhere between gary and south bend, IN.
snow should begin here in the morning as the WAA kicks in and gets thrown over some pretty cold air. it will get heavier as the afternoon goes on and there could be some impressive rates nearing a 1"/hr in some spots. what happens next will be key. if the low can track alittle bit further southeast then most areas should stay snow due to alot of insentropic lift and some intense precip rates with a mix possible down near joliet and kankakee. I think it will come down to a nowcast event tomorrow but right now for amounts. I will go with a foot possible out by RFD. 6-9" from sugar grove to the elgin/streamwood area to 3-6 for the plainfield/bolingbrook area tampering to 2-4 for MDW. subject to change and will try to do another post late tonight after the 0z runs or in the morning.
all in all. a major winter storm is going to affect the area beginning the morning and lasting to weds afternoon with wind gusts nearing 45mph and creating possible blizzard conditions for a time weds morning.
Matt
Sunday, December 6, 2009
Major winter storm on the way!!
first wave with snow associated with it is currently moving across the central plains with a band of 2-4 inches possibly setting up from parts of NE to southern WI. really dont think this will have a big play with the monster but maybe we'll get lucky and it will push the baroclinic zone a tad further south for the 2nd system to ride along.
current radar of the snow....
http://radar.weather.gov/Conus/full_loop.php
now we get into the fun stuff. A long wave trof will dive into the western U.S. with a piece of energy associated with it and will be in the four corners region getting its act together tuesday morning.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_500_048l.gif
This piece of energy will kick out of the rockies as a surface low develops nicely and moves out of CO and will likely run along the KS/OK border.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_500_060l.gif
The surface low will then track ENE across southern MO and then into northwest IN by wednesday. heavy snow will be likely on the northwest side of the sfc low. also, WAA precip will fall out ahead of the low in the midwest during the day tuesday and will fall mostly in the form of snow and accumulate several inches before switching over to a mix during the evening in some locations.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_pcp_066l.gif
DSM,LSX,DVN,MKX, and LOT have all put out headlines for this storm with the afternoon packages with LOT going with WSW's for the fox river on west for accumulations of 10 inches near the rock river and 6 inches for the fox river valley, I am right along the fox river and on the southeast most edge of the winter storm watches.
I believe there is going to be a large spread of accumulations ranging from 1-2 far southeast to possibly over a foot out by RFD. all of this will depend on the track and a 50 mile shift will have major implications. a big player in the precip type further south will be the amount of WAA and if precip can stay snow in spots due to the amount of lift and precip rates or if the warming will overcome that and switch places over to a mix.
all in all, a very dynamic and very strong storm system. some models bringing it down to 980mb in northern IN with some insane with gusts nearing 50mph creating blizzard conditions in spots. wouldn't be suprised to see DVN and MKX go with blizzard watches/warnings as we near closer to the event.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_pcp_078l.gif
current radar of the snow....
http://radar.weather.gov/Conus/full_loop.php
now we get into the fun stuff. A long wave trof will dive into the western U.S. with a piece of energy associated with it and will be in the four corners region getting its act together tuesday morning.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_500_048l.gif
This piece of energy will kick out of the rockies as a surface low develops nicely and moves out of CO and will likely run along the KS/OK border.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_500_060l.gif
The surface low will then track ENE across southern MO and then into northwest IN by wednesday. heavy snow will be likely on the northwest side of the sfc low. also, WAA precip will fall out ahead of the low in the midwest during the day tuesday and will fall mostly in the form of snow and accumulate several inches before switching over to a mix during the evening in some locations.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_pcp_066l.gif
DSM,LSX,DVN,MKX, and LOT have all put out headlines for this storm with the afternoon packages with LOT going with WSW's for the fox river on west for accumulations of 10 inches near the rock river and 6 inches for the fox river valley, I am right along the fox river and on the southeast most edge of the winter storm watches.
I believe there is going to be a large spread of accumulations ranging from 1-2 far southeast to possibly over a foot out by RFD. all of this will depend on the track and a 50 mile shift will have major implications. a big player in the precip type further south will be the amount of WAA and if precip can stay snow in spots due to the amount of lift and precip rates or if the warming will overcome that and switch places over to a mix.
all in all, a very dynamic and very strong storm system. some models bringing it down to 980mb in northern IN with some insane with gusts nearing 50mph creating blizzard conditions in spots. wouldn't be suprised to see DVN and MKX go with blizzard watches/warnings as we near closer to the event.
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_pcp_078l.gif
Tuesday, December 1, 2009
Here comes the storm and possible snow
Upper level low is currently moving slowly east over TX with the northern stream energy continuing to dig further south across the northern plains. seems as low the northern stream is diggind further south then some models and the RUC has picked up on that as well as developing a low near the gulf coast later on in a location a bit east of the NAM, pretty far west of the GFS and in line the best with the Euro run of last night.
here is a WV 24 loop where you can clearly see the ULL spinning in TX with the northern stream energy diving south....http://weather.cod.edu/loops/US-WV24.loop.html
There is already a 1000mb low in the gulf off the LA/TX coastline. there was not supposed to be a 1000mb for atleast another 12 hours. if the southern and northern stream can come together sooner then progged, we could end up with a slightly stronger solution with a track farther west.
Have the feeling some people could be suprised with a 2-4 inch snow band from MO through parts of IL into MI from late tomorrow night into thursday. the surface will track NNE across the OV, most likely from northern LA up through western TN then along the IN/OH border. along the way it will continue to deepen and should get down near 992 going into OH. this will aid in a defo band forming on the northwest side of the low and with CAA and heavy precip, that should help cool the column for all snow and possibly some nice rates for a time.
will try to have more later after the 0z runs come in.
Matt
here is a WV 24 loop where you can clearly see the ULL spinning in TX with the northern stream energy diving south....http://weather.cod.edu/loops/US-WV24.loop.html
There is already a 1000mb low in the gulf off the LA/TX coastline. there was not supposed to be a 1000mb for atleast another 12 hours. if the southern and northern stream can come together sooner then progged, we could end up with a slightly stronger solution with a track farther west.
Have the feeling some people could be suprised with a 2-4 inch snow band from MO through parts of IL into MI from late tomorrow night into thursday. the surface will track NNE across the OV, most likely from northern LA up through western TN then along the IN/OH border. along the way it will continue to deepen and should get down near 992 going into OH. this will aid in a defo band forming on the northwest side of the low and with CAA and heavy precip, that should help cool the column for all snow and possibly some nice rates for a time.
will try to have more later after the 0z runs come in.
Matt
Monday, November 30, 2009
accumulating snow weds night/thursday??
Currently our system is spinning across mexico and will move into TX over the next 24-36 hours. the last few runs of the assorted models have moved the track of the low back further west, with the NAM being the farthest west and GFS/Euro back east with the Euro being the most consistent. HPC is also going with the Euro for now. Seems that most of the time with these split flow regimes that has the southern stream ejecting out and taking on a negative tilt. It will also depend on how far south the northern stream can dig south and if it can slow down allowing for the southern stream wave to catch it and phase with it. the earlier it can phase and the stronger it is, the farther west the low pressure will track. later phase/no phase, then the storm could run east of the Apps near the east coast.
All the models have got away for the ladder and most have a low going from northern AL up through KY/TN and then through OH/PA with the NAM taking it from west of memphis into IN then MI. if that verified then it would be slighty to west for us to get all snow, would probably go from rain to heavy snow. there is a pretty big spread between the models but hopefully by tomorrow night there will be a better agreement on the track as the northern stream energy getting sampled better with it being completely on shore.
looks to be a pretty dynamic system with it being able to draw in colder air than the previous one. I keep thinking of the 11/30/06 snowstorm that hit us pretty good with near 8 inches of snow. the NAM was the first to jump on the westward track a few days before and the other models picked up on it at the last minute. the pre-thanksgiving storm of 2004 also comes to mind as it was a setup like this with the northern stream energy running along the canada/US border and the a wave from the southern stream heading northeast. that was also forecasted by the models to end up further southeast of here but verified back northwest giving the area 4-6 inches of snow.
really dont see lack of cold air being a problem with this in the snow band, the crystal growth layers between 700-500 mb with this are pretty stinkin cold, temps range from -10 to -20C, which means good size flakes with this and the surface temps should cool rapidly with good precip rates falling into it. the snow shouldn't have any problems sticking. another thing to watch is how much moisture can be thrown back into the cold sector, GFS putting out alot of storms along the gulf coast and southeast U.S. along the CF, although im sure some of that is convective feedfack. very fun having a interesting storm to watch and forecast.
Still to early to say much about amounts but would think a general 3-6 in the defo band/trowal on the northwest side of the low. the speed of the system will not help the big accumulations. If I were to bet, id say the band ends up being from STL to ORD to western MI, would need to see more of a NW trend from the models.
Matt
All the models have got away for the ladder and most have a low going from northern AL up through KY/TN and then through OH/PA with the NAM taking it from west of memphis into IN then MI. if that verified then it would be slighty to west for us to get all snow, would probably go from rain to heavy snow. there is a pretty big spread between the models but hopefully by tomorrow night there will be a better agreement on the track as the northern stream energy getting sampled better with it being completely on shore.
looks to be a pretty dynamic system with it being able to draw in colder air than the previous one. I keep thinking of the 11/30/06 snowstorm that hit us pretty good with near 8 inches of snow. the NAM was the first to jump on the westward track a few days before and the other models picked up on it at the last minute. the pre-thanksgiving storm of 2004 also comes to mind as it was a setup like this with the northern stream energy running along the canada/US border and the a wave from the southern stream heading northeast. that was also forecasted by the models to end up further southeast of here but verified back northwest giving the area 4-6 inches of snow.
really dont see lack of cold air being a problem with this in the snow band, the crystal growth layers between 700-500 mb with this are pretty stinkin cold, temps range from -10 to -20C, which means good size flakes with this and the surface temps should cool rapidly with good precip rates falling into it. the snow shouldn't have any problems sticking. another thing to watch is how much moisture can be thrown back into the cold sector, GFS putting out alot of storms along the gulf coast and southeast U.S. along the CF, although im sure some of that is convective feedfack. very fun having a interesting storm to watch and forecast.
Still to early to say much about amounts but would think a general 3-6 in the defo band/trowal on the northwest side of the low. the speed of the system will not help the big accumulations. If I were to bet, id say the band ends up being from STL to ORD to western MI, would need to see more of a NW trend from the models.
Matt
Tuesday, November 24, 2009
two waves, second with snow.
well the first wave is moving through the area with a sfc low now on the IA/IL border southwest of the davenport area, looks almost stationary but barely moving off the northeast it looks like. we have been socked under some descent rain all afternoon as well as northwest IL, eastern IA, and southern WI. there were some thunderstorms earlier today down near macomb and still a slight chance of a rumble of thunder.
looking at upper air data off meso-analysis, the low is vertically stacked all the way up. what will be interesting to watch is what goes on around here tomorrow night into thanksgiving on thursday. the 2nd wave is still up in canada but will begin to dive southeast into the U.S. and will be in the dakotas by morning and in MN in the afternoon. this 2nd wave looks to be a tad stronger then the one moving through the area now. this will slow down the departing first low and a trough will develop and rotate around the west side of the low. it will reinforce the cold air with the upper low moving into eastern IA by late tomorrow night and bringing 850 temps down to -3 and colder.
progs are showing very nice UVV and the possibility of a trowal like feature developing tomorrow evening with the best lift setting up from eastern IA to southwest/southern WI. most models do have the defo band/trowal on them but the exact location of it is the challenge. DVN also mentioned some convective development possible due to the steep mid-level lapse rates. the question is when the changeover from rain to snow occurs. the last few runs the GFS has been a tad warmer with the boundary layer temperatures, where the NAM and EURO are colder. with as much lift associated with this system and the really cold air aloft, I would think to go with the NAM and EURO and the faster changeover, but will have to be monitored.
MKX did put out a SWS for their CWA with the possiblity of 3-4 inches of snow in a small area saying the most snow should accumulate south and west of a line from the dells down to burlington. right now think the best area for the most snow would be from the DBQ/CWI/freeport area on northeast to south of MKX but we will have to see. wouldn't be suprised to see an inch or so down this way on grassy surfaces if the band can make it this far south. some models are showing that, here is an example...
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/hiresw/12/images/hiresw_slp_048l.gif
with this being the 12hr QPF forecast
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/hiresw/12/images/hiresw_p12_048l.gif
going to interesting to see what the 0z NAM says as well as the new short range models later on. wouldn't be suprised to see a 4 inch amount somewhere if a nice band can set itself up and drop some moderate to heavy snow for a short period. nice having something exciting to watch and forecast and getting giddy with winter getting underway.
Matt
looking at upper air data off meso-analysis, the low is vertically stacked all the way up. what will be interesting to watch is what goes on around here tomorrow night into thanksgiving on thursday. the 2nd wave is still up in canada but will begin to dive southeast into the U.S. and will be in the dakotas by morning and in MN in the afternoon. this 2nd wave looks to be a tad stronger then the one moving through the area now. this will slow down the departing first low and a trough will develop and rotate around the west side of the low. it will reinforce the cold air with the upper low moving into eastern IA by late tomorrow night and bringing 850 temps down to -3 and colder.
progs are showing very nice UVV and the possibility of a trowal like feature developing tomorrow evening with the best lift setting up from eastern IA to southwest/southern WI. most models do have the defo band/trowal on them but the exact location of it is the challenge. DVN also mentioned some convective development possible due to the steep mid-level lapse rates. the question is when the changeover from rain to snow occurs. the last few runs the GFS has been a tad warmer with the boundary layer temperatures, where the NAM and EURO are colder. with as much lift associated with this system and the really cold air aloft, I would think to go with the NAM and EURO and the faster changeover, but will have to be monitored.
MKX did put out a SWS for their CWA with the possiblity of 3-4 inches of snow in a small area saying the most snow should accumulate south and west of a line from the dells down to burlington. right now think the best area for the most snow would be from the DBQ/CWI/freeport area on northeast to south of MKX but we will have to see. wouldn't be suprised to see an inch or so down this way on grassy surfaces if the band can make it this far south. some models are showing that, here is an example...
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/hiresw/12/images/hiresw_slp_048l.gif
with this being the 12hr QPF forecast
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/hiresw/12/images/hiresw_p12_048l.gif
going to interesting to see what the 0z NAM says as well as the new short range models later on. wouldn't be suprised to see a 4 inch amount somewhere if a nice band can set itself up and drop some moderate to heavy snow for a short period. nice having something exciting to watch and forecast and getting giddy with winter getting underway.
Matt
Tuesday, October 27, 2009
Impressive first system?? maybe weaker with strong 2nd wave...
huge storm system in the early stages dumping a ton of snow in the WY/CO area this evening and should continue into thursday with some areas possibly picking up 2-3 feet of snow!! this is being cause by a very large trof carved out over the western US. something pretty rare for this time of the year with numbers of -4.5 standard deviations. the sfc low then begins to head northeast through the dakotas into MN and really intensify along the way. not fast enough to throw out bombogenesis but impressive to say the least and could drop to near 976 once it passes over lake superior into canada.
as for the warm side of the storm, and some severe weather will be the main threat with this and alot of gulf moisture will work its way north and with a strong CF, people are going to get some heavy rain the mississippi valley down through the southern plains. right now AR is the QPF bullseye with possibly 6 inches of rain in some spots. it wont be as bad here but we could see possibly 1-2 inches and some thunder thursday night into friday morning before the CF passes through.
We could of been looking at a huge severe weather/tornado outbreak if we had some dam instability but that is not going to happen. lapse rates are going to suck. wind fields are very impressive in the plains and midwest and with a tad amount of instability, damaging winds in any thunderstorm/squall line would be the main threat. with near 60kts at 850mb, wouldnt take much here to mix down a severe gust in a thunderstorm late thursday night. TX/OK look to be the area for tomorrow and then all up and down the CF thursday from IL to LA.
the interesthing thing tonight on the 0z GFS run is how the first system comes out a bit weaker and a good amount of energy gets left behind and rounds the base of the trof and sits in TX/OK at 90 hours. it then organizes itself into a nice area of low pressure and runs northeast west of the apps into OH. the models have been trying to develop a second wave for days but this is by far the most aggressive run yet with it. It would be pretty hard to get snow but not impossible and with a stronger wave and better UVV, it could create its own cold air and maybe produce some snow. interesting to see how everything plays out.
Matt
as for the warm side of the storm, and some severe weather will be the main threat with this and alot of gulf moisture will work its way north and with a strong CF, people are going to get some heavy rain the mississippi valley down through the southern plains. right now AR is the QPF bullseye with possibly 6 inches of rain in some spots. it wont be as bad here but we could see possibly 1-2 inches and some thunder thursday night into friday morning before the CF passes through.
We could of been looking at a huge severe weather/tornado outbreak if we had some dam instability but that is not going to happen. lapse rates are going to suck. wind fields are very impressive in the plains and midwest and with a tad amount of instability, damaging winds in any thunderstorm/squall line would be the main threat. with near 60kts at 850mb, wouldnt take much here to mix down a severe gust in a thunderstorm late thursday night. TX/OK look to be the area for tomorrow and then all up and down the CF thursday from IL to LA.
the interesthing thing tonight on the 0z GFS run is how the first system comes out a bit weaker and a good amount of energy gets left behind and rounds the base of the trof and sits in TX/OK at 90 hours. it then organizes itself into a nice area of low pressure and runs northeast west of the apps into OH. the models have been trying to develop a second wave for days but this is by far the most aggressive run yet with it. It would be pretty hard to get snow but not impossible and with a stronger wave and better UVV, it could create its own cold air and maybe produce some snow. interesting to see how everything plays out.
Matt
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