A slow-moving, but quickly strengthening, low pressure storm system makes its way across the southern half of the country today before reaching the Northeast by Thursday. This system will drop snow, rain, and ice over regions in its path.
This is the Wednesday edition of your Morning Briefing. Let’s dive right in.
Heavy Rainfall and Potential Flash Flooding for the Southeast today and Thursday:
- TX and the Lower and Central Mississippi Valleys can expect two rounds of rainfall this week. The first, today, will be heavier and slow-moving. The second, tomorrow, will likely be much weaker with lighter rains.
- Totals for TX are expected to reach 1-3″ across the area by the end of the day today. For Lower and Central Mississippi Valleys, totals will be higher, near 5″. Any developing thunderstorms over the region will enhance rainfall totals and rates as well.
- Rainfall tomorrow will not be nearly as high, but flooding and flash flooding possible today will only be enhanced by even moderate rainfall tomorrow.
- Flood and flash flood watches will be in effect over the area until noon on Thursday.
As this low pressure system develops today, jet dynamics and flow from the Gulf work together to bring high amounts of precipitable water into the storm’s path. Parts of SE TX and the Lower and Central Mississippi Valleys are under flood and flash flood watches today. Rainfall across TX is expected to be around 1-3″, while further east, totals along the Central Mississippi will likely get up to 5″. Saturation from previous rains will exacerbate the effects of any moderate to heavy rainfall during this period. Minor to moderate flooding can be expected in many of these areas, with parts of the region watching for flash floods. Any developing thunderstorms in the affected region will increase local rainfall totals, and increase chances for flooding and flash flooding. After the initial rain is over, another period of rain is set to begin around midday Thursday. Although this will likely be much less intense than today’s downpours, flooding from today will be worsened by even moderate rainfall tomorrow.
Snow and Ice to Cause Dangerous Conditions for NM, TX, and OK:
- Snow and ice will accumulate across NM, TX, and OK today causing hazardous traveling and outdoor conditions until Thursday afternoon.
- Precipitation will likely start as freezing rain/rain to the east, and light snow to the west. As these air masses collide, precipitation rates will increase, and the switch to all frozen precipitation types begins. This afternoon, a slushy mess of snow and freezing rain is expected, and by tonight, most precipitation will have switched to all snow.
- Ice accretion totals will likely be light (>0.25″) but can still worsen road conditions when combined with rain and snow.
- Snowfall totals across the region are expected to be up to 5″ by Thursday afternoon.
While heavy rains flood further east, a wintry mix of snow and ice will mean dangerous conditions throughout parts of the Southern Rockies and Plains. Precipitation will start as snow over NM, and ice over parts of Central TX. As snow moves further east, it collides with the slightly warmer air mass over Eastern TX, increasing overall precipitation amounts over northern Central TX. Rain will quickly switch to either freezing rain or snow this afternoon, causing dangerous conditions for the evening rush. Ice accretion totals are expected to be light, but will still cause slippery roads in combination with rain and snow. By tonight, there will be a switch to almost all snow. Snowfall will remain relatively light, but likely fall well into Thursday, allowing up to 4″ to accumulate over much of the region.
Snow and Rain Reach the Northeast Thursday:
- A weak clipper system will interact with the incoming low pressure system from the south early Thursday morning.
- All rain will be seen by the Mid-Atlantic, but as we get further north to where these air masses interact, we will see some brief mixing of snow and rain near Southern NY, Eastern PA, and Interior CT. Snowfall here could be anywhere from a dusting to an inch, but likely will quickly melt away from rain and warming.
- Further north, Upstate NY could see about an inch as well, but no rain to wash it out. VT and NH will likely see 1-3″ with the passage of this system.
As rain from the surface low moves into the Northeast early Thursday, it will interact with an upper-level clipper system. For the most part, they will only graze each other, but some interaction over eastern PA and southern NY could mean some mixed precipitation as snow or snow/rain mix at the systems’ onset. Up to an inch of snow could be seen for Interior CT and eastern LI, but will likely melt away soon as rain begins and temperatures continue to warm. As we move further north, snow totals will increase and the chance for any rain dramatically decreases. Upstate NY could see an inch or two by Thursday morning, while VT and NH can expect up to 3″. Overall, this should be a very low-impact event for the Northeast, with strong model consensus for low available moisture and light winds. However, following close behind this system is another weekend system that could bring even more rain to the region.
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Also remember to lookout for The Sunday Storm this upcoming Sunday evening as well as Five Things to Watch This Week on Monday.