Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 252 AM EST Wed Jan 10 2024 Valid 12Z Wed Jan 10 2024 - 12Z Fri Jan 12 2024 ...Strong storm affects New England on Wednesday, followed by improving conditions... ...Unsettled weather conditions continue for the Western U.S. with much colder temperatures arriving for the Northern Plains... A very potent mid-upper level trough over the Northeast U.S. is sustaining a very strong surface low over southern Ontario early Wednesday morning, and this low will continue lifting toward the northeast across southern Quebec by Wednesday evening. The strong cold front trailing south from the parent low will exit New England by Wednesday afternoon. Widespread hazardous weather impacts are expected for the Northeast U.S. in association with this low pressure system on Wednesday, and numerous warnings and advisories are now in effect from the local NWS forecast offices. One of the big things making weather headlines will be the heavy rain capable of producing flooding from southern New England to southern Maine. There is a Slight Risk of excessive rainfall now highlighted by the Weather Prediction Center for Wednesday across southern portions of Maine, where the combination of 1 to 3 inch rainfall totals over highly saturated, and in some cases snow covered ground, along with swollen creeks and streams, will elevate the potential for flooding across this region. It will also be quite windy across this region as well, with winds gusting over 50 mph, especially near the coast and for elevated areas where gusts will likely exceed 60 mph. Therefore, high wind warnings are in effect for many areas near the coast and the higher terrain of the Northeast, and storm warnings for the open waters. This will also cause instances of coastal flooding where strong onshore flow piles up water into rivers and bays. For the Western U.S., the weather pattern will also be active with a strong Pacific front moving inland with very heavy snow for the Cascades and Sierra, and then across the higher mountain ranges of Nevada, with snow levels dropping over time. This disturbance then settles southeastward across the Desert Southwest and this brings valley rain and mountain snow across Arizona and New Mexico going into Thursday. Meanwhile, a potent arctic front drops southward from Canada on Wednesday and this will herald the arrival of the coldest temperatures so far this season for the Northern Plains, with subzero lows becoming a reality for Montana and the Dakotas, and highs remaining below freezing as far south as Oklahoma by Friday. This arctic airmass will likely persist well beyond this forecast period. The combination of this front and the storm system from the southwestern U.S. will eventually result in a much larger low pressure system developing over the Southern Plains by the end of the week. The initial set-up for this next event is quite similar to the ongoing event that is now concluding over the Eastern U.S. with a comparable track for the surface low, but the main difference is a greater supply of arctic air northwest of the low track. Blizzard conditions are becoming increasingly likely for portions of the Midwest as the low quickly deepens, and a return to severe thunderstorms and heavy rain for the Gulf Coast region. This storm system will continue to be monitored closely since it will likely be highly impactful once again for the east-central U.S. on Friday. Hamrick Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php