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May the 4th Overview: Clouds, Rain, Drizzle…Cut-off Low Woes by Friday

In a galaxy far, far away the weather is probably 1000 times better than it has been here this week. It’s about as miserable as it gets out there. Cold, damp and raw. This all due to omega block, which we’ve been discussing since Sunday, that has set up across over North America this week. While complete washouts aren’t still anticipated, there will be little to force these damp and dreary weather conditions out of the region until the blocking pattern begins to break down this weekend.

Through the day on Thursday, waves of low pressure are expected to develop along the coast. These waves will not interact or form a bigger storm along the coast, but a potent mid-level disturbance could come underneath a favorable position of an upper-level jet. This would  enhancing more widespread showers or periods of rain. Other models show the aforementioned upper-level jet further east of the region, supporting less rainfall. Cloud cover and onshore winds will keep temperatures from rising out of the lower to middle 50s.

Afterward, it may get more complicated with the energy associated with the  upper-level trough forming a cut-off low over the Carolinas on Thursday night. This cut-off will expand and slowly head northward into our region on Friday. Shortwave energy and surface low pressure consolidating underneath this upper-level low will lead to opportunities for more steady, heavier rainfall on Friday. Various model solutions still continue, offeringlow confidence on timing and rainfall totals at this time. But chances for a significant rainfall on Friday appear to be gradually increasing with models trending toward a more organized system as a whole.

6z GFS 66hr

Large cut-off low on GFS that is

This cut-off low is likely to slowly weaken Friday night and Saturday, but still could affect the area with some lingering showers. Temperatures are likely to average cooler than normal both Friday and Saturday with cloud cover and east to northeast winds. A persistent onshore flow out of the east or northeast and a new moon cycle will lead to an increasing threat of coastal flooding during high tides through Friday and perhaps Saturday.

A cold front approaching from the west will be the necessary force to push the cut-off low away from our regions with some showers Saturday night into Sunday morning marking its passage. Clearing is expected on Sunday with more reasonable weather conditions on Mothers Day.

May the 4th be with you.