afterimage Posted February 24, 2011 Share Posted February 24, 2011 MESOSCALE DISCUSSION 0128 NWS STORM PREDICTION CENTER NORMAN OK 0520 PM CST THU FEB 24 2011 AREAS AFFECTED...SERN IA...NERN MO...PORTIONS OF NRN/CNTRL IL/IN CONCERNING...HEAVY SNOW VALID 242320Z - 250515Z SNOWFALL WILL SPREAD E-NEWD ACROSS SERN IA...NERN MO...AND PORTIONS OF NRN/CNTRL IL/IN THIS EVENING. RATES WILL INCREASE TO 1 INCH PER HOUR...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. STRONG ASCENT IN ASSOCIATION WITH THE INTENSE EXTRATROPICAL CYCLONE APPROACHING THE MISSISSIPPI VALLEY REGION WILL ALLOW PRECIPITATION TO EXPAND E-NEWD ACROSS THE DISCUSSION AREA. WHILE THERMAL PROFILES WILL INITIALLY BE SUPPORTIVE OF RAIN ACROSS PORTIONS OF IL/IN... RUC/NAM FORECAST SOUNDINGS INDICATE SUFFICIENT LOWER TROPOSPHERIC COOLING THROUGH THE EVENING FOR THE PRECIPITATION TO CHANGE TO SNOW. THIS WILL BE IN RESPONSE TO COLD AIR ADVECTION WEST OF THE CYCLONE AND WILL BE AUGMENTED BY ADIABATIC COOLING ASSOCIATED WITH INTENSE FORCING. SNOWFALL RATES ARE EXPECTED TO REACH 1 INCH PER HOUR THROUGH THE EVENING...AS LOW/MID-LEVEL FRONTOGENESIS QUICKLY STRENGTHENS INVOF THE BAROCLINIC ZONE DRAPED ACROSS THE OHIO VALLEY REGION. ACROSS SRN PORTIONS OF THE DISCUSSION AREA...SNOWFALL RATES TO 2 INCHES PER HOUR WILL BE POSSIBLE. IN THIS REGION...THE JUXTAPOSITION OF AN AXIS OF DEEPER MOISTURE PER RECENT TPW IMAGERY WITH INCREASING SLANTWISE INSTABILITY WILL LIKELY SUPPORT PRECIPITATION BANDING AND LOCALLY HIGHER RATES...ESPECIALLY IF AN ISOLATED THUNDERSTORM WERE TO OCCUR. ..COHEN.. 02/24/2011 bring it on Link to comment Share on other sites More sharing options...
KokomoWX Posted February 24, 2011 Share Posted February 24, 2011 Here is s guy who is going to bust.... Chad from TV 18 Link to comment Share on other sites More sharing options...
snowstormcanuck Posted February 24, 2011 Share Posted February 24, 2011 Here is s guy who is going to bust.... Chad from TV 18 TV mets should have access to better map making software than that. Looks like an ms paint job. Link to comment Share on other sites More sharing options...
Hoosier Posted February 25, 2011 Share Posted February 25, 2011 Here is s guy who is going to bust.... Chad from TV 18 Wow. Haven't been reading the blog lately but I'd like to know the thought process behind that. In case anyone is wondering, that map came from here: http://blogs.wlfi.com/category/chads-wlfi-weather-blog/ Link to comment Share on other sites More sharing options...
afterimage Posted February 25, 2011 Share Posted February 25, 2011 TV mets should have access to better map making software than that. Looks like an ms paint job. I can't disagree with that, as a person who has spent 20+ years making maps, and doing analysis with various map pkgs/GIS, there is a wide array available to them. Link to comment Share on other sites More sharing options...
Stebo Posted February 25, 2011 Share Posted February 25, 2011 TV mets should have access to better map making software than that. Looks like an ms paint job. Yeah and whats with the randomness of the lines. Link to comment Share on other sites More sharing options...
Chicago WX Posted February 25, 2011 Share Posted February 25, 2011 Wow. Haven't been reading the blog lately but I'd like to know the thought process behind that. In case anyone is wondering, that map came from here: http://blogs.wlfi.com/category/chads-wlfi-weather-blog/ Dude is a chop. Look at his snowfall map from last night. Alas it is small market TV here... Link to comment Share on other sites More sharing options...
Powerball Posted February 25, 2011 Share Posted February 25, 2011 18z NAM cobb for Detroit shows 10" with only .44" of QPF. Only on the 18z runs. Link to comment Share on other sites More sharing options...
kab2791 Posted February 25, 2011 Share Posted February 25, 2011 18z NAM cobb for Detroit shows 10" with only .44" of QPF. Only on the 18z runs. Link to comment Share on other sites More sharing options...
Powerball Posted February 25, 2011 Share Posted February 25, 2011 I can see how fluffier/higher totals would be possible if we can somehow align the moisture with the intense omega around 500mb (smack dab in the DGZ). Otherwise, yeah, typical BS from the 18z NAM. Link to comment Share on other sites More sharing options...
Hoosier Posted February 25, 2011 Share Posted February 25, 2011 Dude is a chop. Look at his snowfall map from last night. Alas it is small market TV here... Yeah, looks like last night's had the heaviest south of here. Here's what I think. Precip begins later this evening, possibly as a period of rain or mix. Surface temps should still be above freezing when precip begins but it shouldn't take long for them to cool to near and then just below freezing. 6-8" with higher amounts over 8 to possibly near a foot wherever the heavier banding is most persistent. Link to comment Share on other sites More sharing options...
cyclone77 Posted February 25, 2011 Share Posted February 25, 2011 Looking to me like the northern edge of this system in Iowa may bust. There is a heavy band from southeast Nebraska into southern Iowa, but it is not making any progress northward. Omaha was supposed to get 2-4 inches, but the northern half of the city apparently hasn't received a flake and the snow is pulling away. Des Moines has 2-5 for their metro and it appears they are only getting brushed by the band with nothing being reported north of Des Moines. Yeah it looks like a big bust is in the making for areas north of I-80. The donut hole around the DVN radar looks the same as it did a few hours ago. Starting to wonder if we'll get any accumulation at all now. Oh well, at least we had our fun already this season. Link to comment Share on other sites More sharing options...
Chicago Storm Posted February 25, 2011 Author Share Posted February 25, 2011 1" or less seems to be a good call here. Link to comment Share on other sites More sharing options...
Powerball Posted February 25, 2011 Share Posted February 25, 2011 DTX says around 1" per hour rates before/during the morning rush hour, and there's even a marginal chance for convection. This is per the 00z Aviation Update. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted February 25, 2011 Share Posted February 25, 2011 Yeah and whats with the randomness of the lines. Maybe he had coffee induced caffeine twitches as he drew the lines. Link to comment Share on other sites More sharing options...
Chicago WX Posted February 25, 2011 Share Posted February 25, 2011 Yeah, looks like last night's had the heaviest south of here. Here's what I think. Precip begins later this evening, possibly as a period of rain or mix. Surface temps should still be above freezing when precip begins but it shouldn't take long for them to cool to near and then just below freezing. 6-8" with higher amounts over 8 to possibly near a foot wherever the heavier banding is most persistent. Done deal then. I'll defer to you with this one. Still worried about the changeover, or how much rain/mix falls before the flip to snow, but I can see what you're seeing. Let's go out with a bang. Link to comment Share on other sites More sharing options...
Powerball Posted February 25, 2011 Share Posted February 25, 2011 GRR provides some hope yet... 000FXUS63 KGRR 250008 AFDGRR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 705 PM EST THU FEB 24 2011 LATEST UPDATE...AVIATION... MVFR CIGS DOMINATE THE WEATHER MAP OVER SOUTHERN LOWER MICHIGAN AT 7 PM THIS EVENING. HOWEVER THERE SEEMS TO BE SOME BREAKS IN THOSE CLOUDS OVER THE CENTRAL AND EASTERN SECTIONS SINCE JXN REPORTS CLEAR. MOST OF THE OTHER OBS AROUND JXN SHOW VFR CIGS AROUND 3500 FT AGL. WITH A NORTH NORTHEAST WIND IN THE BOUNDARY LAYER I EXPECT THE CLOUDS TO REMAIN (HELP FROM LAKE HURON) THOUGH THE NIGHT AND THROUGH FRIDAY IN FACT. THE TOUGH QUESTION IS HOW FAR NORTH THE SNOW FROM THE SYSTEM TO OUR SOUTH GETS TONIGHT. I WONDER IF THE FACT THAT THE SYSTEM DOES NOT HAVE A CLOSED CIRCULATION AT 500 MB WILL KEEP THE SNOW FROM REACHING THE I-96 TAF SITES. I DID NOT PUT SNOW AT MKG FOR THAT REASON. EVEN AT GRR AND LAN I HAVE TO WONDER IF THE FGEN WILL CAUSE NARROW BUT MORE INTENSE BANDS OF SNOW THAT WILL KEEP THE SNOW SOUTH OF THOSE TAF SITES TOO. FOR THAT I PLAYED THE SNOW DOWN AT GRR AND LAN. IT WOULD SEEM AZO...BTL AND JXN SHOULD GET A PERIOD OF HEAVY SNOW. I USED THE HRRR 21Z RADAR FORECAST AND HOURLY SNOWFALL RATES TO TIME THE HEAVY SNOW INTO THOSE TAF SITES. WE SHALL SEE HOW WELL THAT WORKS BUT I HAVE NOTED THIS WINTER THAT THE HRRR DOES A VERY GOOD JOB WITH THIS SORT OF FEATURE. (I HAVE ABOUT 5 EVENTS IN MY IN HOUSE CASE STUDY SO FAR). Link to comment Share on other sites More sharing options...
afterimage Posted February 25, 2011 Share Posted February 25, 2011 Done deal then. I'll defer to you with this one. Still worried about the changeover, or how much rain/mix falls before the flip to snow, but I can see what you're seeing. Let's go out with a bang. Anything that involves "bangin'" or going out with "bangin" is Oh, wait, snow, yes, that is gr8 too. Link to comment Share on other sites More sharing options...
Chicago Storm Posted February 25, 2011 Author Share Posted February 25, 2011 1000mb SLP along the AR/TN border, just north of Memphis. Best pressure falls are in C. Kentucky. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted February 25, 2011 Share Posted February 25, 2011 1000mb SLP along the AR/TN border, just north of Memphis. Best pressure falls are in C. Kentucky. NW trend fail. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted February 25, 2011 Share Posted February 25, 2011 Looks like we could end up with more snow saturday than tonight lol 18z NAM has .25"+ from just of DVN to DKB. Link to comment Share on other sites More sharing options...
KeenerWx Posted February 25, 2011 Share Posted February 25, 2011 Done deal then. I'll defer to you with this one. Still worried about the changeover, or how much rain/mix falls before the flip to snow, but I can see what you're seeing. Let's go out with a bang. Looks like we'll snag 5th with this one. 3rd and 4th not far off, especially if we overperform, and we get a little present in March (although after the warm up 2 weeks ago, I'm pretty ready for spring). Link to comment Share on other sites More sharing options...
hawkeye_wx Posted February 25, 2011 Share Posted February 25, 2011 1000mb SLP along the AR/TN border, just north of Memphis. Best pressure falls are in C. Kentucky. Yep, that's WAY down there. We will rarely get snow with a track so far south... and the Quad Cities just took out all snow accumulation from CR north. Des Moines is already done before they ever got started. Link to comment Share on other sites More sharing options...
dmc76 Posted February 25, 2011 Share Posted February 25, 2011 Yeah and whats with the randomness of the lines. Link to comment Share on other sites More sharing options...
cyclone77 Posted February 25, 2011 Share Posted February 25, 2011 Yep, that's WAY down there. We will rarely get snow with a track so far south... and the Quad Cities just took out all snow accumulation from CR north. Des Moines is already done before they ever got started. Yep. A big miss northwest last weekend, and now southeast tonight. Hopefully early next week we split the difference lol. Link to comment Share on other sites More sharing options...
Stevo6899 Posted February 25, 2011 Share Posted February 25, 2011 Was banking on the nw trend, like we had with the feb 1st storm. Was that wave stronger coming out of the 4 corners? Or was there just a more impressive baroclinic zone with that one that was facing more NE and less zonal (like this storm). Link to comment Share on other sites More sharing options...
Chicago WX Posted February 25, 2011 Share Posted February 25, 2011 Looks like we'll snag 5th with this one. 3rd and 4th not far off, especially if we overperform, and we get a little present in March (although after the warm up 2 weeks ago, I'm pretty ready for spring). Yeah 5th place looks doable. Which reminds me, the list I sent you a couple of months ago had some additions errors by yours truly. The list in my sig is now the correct one (notably 07-08 lost 4"...must have been drinking at the time when I added up the snowfall from that winter). Link to comment Share on other sites More sharing options...
baroclinic_instability Posted February 25, 2011 Share Posted February 25, 2011 Was banking on the nw trend, like we had with the feb 1st storm. Was that wave stronger coming out of the 4 corners? Or was there just a more impressive baroclinic zone with that one that was facing more NE and less zonal (like this storm). A lot of reasons--but convection played a huge role--so it does seem it was not negative convective feedback that the NCEP (NAM/GFS) were hitting on. It was such a tough forecast for this reason. We knew convection would play a role in strong pressure falls--just how much that would "drive" storm track was unclear. It does seem convection is playing a large role with this storm heading a bit more E though. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted February 25, 2011 Share Posted February 25, 2011 Was banking on the nw trend, like we had with the feb 1st storm. Was that wave stronger coming out of the 4 corners? Or was there just a more impressive baroclinic zone with that one that was facing more NE and less zonal (like this storm). That was a much more vigorous upper level system that was able to curl the sfc system NW as it intensified. H5 with this system is fairly meager, which has allowed that deep convection developing over the lower MS valley to dictate the direction of the sfc low. That's my layman's interpretation of what b_i was saying yesterday. Maybe he could illuminate you further. Link to comment Share on other sites More sharing options...
Chicago Storm Posted February 25, 2011 Author Share Posted February 25, 2011 0z DVN sounding: Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.