Saturday, December 1, 2007

Winter Storm: Dec. 1-2 -- Live Updates

5:45 PM Update: Small band of showers working through central Iowa currently, another small area in northwest Iowa and the strongest band of showers in southwestern Iowa. These patches of precip will put down a wide variety, ranging from mostly rain in the south to freezing rain in the north. Expect other patches of precip to develop throughout the overnight as the low pressure begins to make its' way into the state; there should however not be any significant amounts. General under a tenth of an inch of rain or freezing rain and an inch or so of snow/sleet at most. Some areas of the state due have problems with driving conditions and there are scattered areas without power; current estimates are ~15,000 people without power across the state, a majority of them in eastern Iowa.

Road conditions are mainly wet for the southern third of the state, partially covered in the central, mostly covered in the northwest. Completely covered in north-central and northeast Iowa, with travel still not advised for areas of east-central Iowa including Cedar Rapids, Iowa City and the Quad Cities. Storm has hampered some areas, but definitely not as widespread as forecasted and the hardest hit areas were luckily not as bad as the worst case scenario. Possibly one more update late tonight, otherwise may work on a recap of the storm tomorrow that will be posted.

3:30 PM Update - Light freezing rain still falling in Ames, has really slowed down for the past hour or so and it looks like it will remain light if at all for the remainder of the evening/night. East of I-35 is the only portion of the state that is currently showing reflectivities on radar, small area of precip on the wrap around for the low in northeast NE. That may track over parts of northwest Iowa and give them an extra shot at frozen precip. Warm air is still slowly pushing into the state, may be able to melt off some of the ice on the roadways, especially in southern half of Iowa. East-central Iowa is the only portion of the state that has 'travel not advised' posted; this will likely continue for eastern Iowa through the evening.

The ice storm warning has been cancelled for much of south-central Iowa; the winter storm warning for portions of northwest Iowa has also been canceled. Expect the remainder of the state to slowly see the warnings continue to expire into the evening as this line passes through. For now I'll cease the updates to only every couple of hours, leaving you with a few pictures I grabbed near my apartment here in Ames:

Fallen Tree Branch -- Small Icicle -- Several Small Icicles

2:00 PM - Currently experiencing freezing rain, heavy at times in the past half hour; accumulations occurred quickly on all of the trees, etc. Looks like a good tenth of an inch of frozen rain, slightly less on some trees. This rain did manage to melt into the sleet that was already there, creating somewhat of a frozen slush mixture. This band centered over I35 currently, continuing to move northeast into the mid-afternoon; behind this band it seems to have cleared off precip wise as a dry slot move in ahead of the low. Unsure on any precip chances after this current band works through, likely done in Ames by 3 PM. That update at 3 PM or just before will have the totals thus far, which may end up to be the final totals depending on how the rest of the system moves through.

1:15 PM - Warm air has made its' way into southwest Iowa, as well as southeast NE and the portions of KS/MO. This has prompted the Omaha NWS to cancel the ice storm warning for portions of the state, due to rain likely falling for the remainder of the afternoon and only light precip likely during the overnight hours when some freezing may occur. Much of the ice in the area that has been dropped will likely melt over the next couple of hours as the rain falls. This warm air has however allowed for a large complex of showers and potential rumbles of thunder to move into southern Iowa and is currently working east-northeast into central Iowa. This will have the potential to bring copious amounts of ice/sleet to the area in very little time. Check out the latest radar image on my homepage to view the location of this next round of precipitation... Temperatures are near freezing in front of the complex, sleet or freezing rain potentially turning over to rain if temperatures continue to rise with the system. Either way it is likely to be a mess over the next couple of hours for areas of central/eastern Iowa as it makes its' way through. Next update likely in an hour or so as this round is overhead...

Noon Update: Light sleet still occurring here in Ames, not sure on additionally accumulation as I haven't gotten back outside yet; will likely do that before next update. Warmer air continuing to make its' way into the state from the southwest, air temperatures and surface temperatures are both rising with its' appearance. Not much for additional reports in the past hour, been fairly quiet actually as a band moves into northeastern/eastern Iowa and moves out of the area; looks like western Iowa is fairly precip free for the time being. The next wave of precip is currently working through along the southwestern corner of Iowa and will likely continue east and north; mainly affecting southern Iowa with a round of rain/frz rain or sleet depending on the temperature profile.

11:00 AM: Moderate to Heavy sleet/graupel was coming down in Ames, seems to have let up a bit in the past couple of minutes. Nearly an inch of sleet accumulation on the ground, a couple of hundredths of an inch of ice on cars and other surfaces. Trees don't seem to have much for accumulation, although I'm sure some may accumulate better than others. Roads are slick however, several accidents have been reported throughout the morning with a couple of injuries possible (ambulances on scene, actual extents unknown). Travel is not advised for areas of southcentral, central and eastcentral Iowa currently; the remainder of the state has roads mostly or completely covered. Essentially travel should not be advised no matter where you are in the state, as conditions are likely to worsen into the afternoon. Power outages in some areas of the state have been reported, this may likely continue into the afternoon; latest estimates have total houses in the thousands. Several reports coming in as far as totals go, however conditions changing so rapidly I'm not going to go through a listing; check out the links to the right for the latest local storm reports.

Expecting sleet/frz rain to continue for much of the state, however the warm air has already made its' way into southwestern Iowa with surface temperatures above freezing now. Rain beginning to be reported at some of the stations along the IA/MO and IA/NE borders. This warm air is likely to slowly make its' way into the rest of the state, we'll have to watch closely as this could really improve conditions as areas where rain has begun in eastern NE report that the ice was melting fairly quick even with the cold rain.

9:30 AM: Freezing rain and light snow accumulating on the ground, a couple of hundredths of ice accumulation on trees and other surfaces. Up to a half an inch of the sleet/snow and ice on the ground however. Road conditions continue to deteriorate, however no complete closures as of yet. Highest snowfall reports out of northwest Iowa where up to 1.5 inches of snow in Spirit Lake & Estherville; sleet now the main form of precipitation as of latest reports; freezing rain occurring and accumulations over a tenth of an inch reports in several areas across the state. Next update likely at 11 AM.

8:45 AM: Freezing rain and sleet mixture began ~15 minutes ago in Ames again, quickly accumulating on the surfaces. This is actually occurring quicker than originally forecasted, thus expect travel conditions to deteriorate rapidly this morning and have roads in some areas closed before Noon. Areas now around Des Moines and Ames are now also under 'Travel Not Advised'; I believe I80 in eastern NE is closed already in some areas due to several jack-knifed semis. Ice accumulation fairly rapidly, next update likely ~9:30 AM.

8:25 AM: A good dusting of snow has occurred in Ames with the light precipitation that has been over the area for the past couple of hours. Some freezing rain has also been falling across the state, checking out the webcams across the state you can tell which areas have really received this as the cameras are iced over already. Surface temperatures over southwest Iowa are already near freezing and a couple of readings above freezing, this may likely cause the changeover to rain within the next hour or two. Thus far for road conditions, south-central Iowa is already indicating that travel is not advised, this includes I-35 south of Des Moines (Towing services prohibited). Storm already underway and thus far making a decent impact within hours...

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