Chesapeake Bay From Pooles Island to Sandy Point MD Marine Forecast
|Today...S Winds 25 Kt With Gusts To 35 Kt...Becoming Sw With Gusts To 30 Kt Late This Morning, Then Becoming Nw 5 To 10 Kt With Gusts To 25 Kt This Afternoon. Waves 4 Ft...Subsiding To 1 To 2 Ft This Afternoon. Scattered Tstms. Rain This Morning, Then Showers This Afternoon. Vsby 1 Nm Or Less.|
|Tonight...Nw Winds 10 To 15 Kt. Gusts Up To 20 Kt. Waves 2 Ft.|
|Fri...Nw Winds 10 Kt. Waves 1 Ft.|
|Fri Night...Nw Winds 5 To 10 Kt. Waves 1 Ft.|
|Sat...W Winds 5 Kt. Waves Less Than 1 Ft.|
|Sat Night...Sw Winds 5 Kt. Waves Less Than 1 Ft.|
|Sun...W Winds 5 To 10 Kt. Waves 1 To 2 Ft.|
|Mon...W Winds 5 To 10 Kt. Waves 1 Ft. Winds And Waves Higher And Visibilities Lower In And Near Tstms.|
| Area Forecast Discussion|
National Weather Service Baltimore MD/Washington DC
401am EDT Thu September 23 2021
A strong cold front associated with an area of low pressure over the Great Lakes will continue to push through the region this morning through this afternoon, resulting in periods of heavy rainfall, gusty showers, and embedded thunderstorms. High pressure returns Friday into the weekend.
Near Term - Through Tonight
A strong, negatively tilted, trough is pushing east out of the Great Lakes/Ohio Valley, with an occluding surface low over Lake Erie. The attendant cold front is gradually working its way across our region. Frontal progression has been a couple hours quicker than originally anticipated, with the current position from north-central MD extending southward towards Richmond. This is clearly evident on radar imagery as well as surface obs with an obvious wind shift and much cooler temps in its wake. This should help speed up the end of precipitation today, and perhaps limit severe potential for portions of the area.
Regarding the flood threat, some very impressive north-south training elements along/ahead of the front have been developing this morning amidst the very moist air mass ahead of the front. Flooding has been the main threat with the convective line at this time, but only in isolated spots. Expect tropical downpours to continue as the front passes this morning, with potential for more isolated instances of flooding/flash flooding. Have allowed the Flash Flood Watch for areas south and west to end early, with northern/eastern areas remaining in for now. These will gradually be pulled from west to east today.
As for severe potential, it remains non-zero. There is an abundance of shear along/ahead of the front, as well as a tongue of around 500 J/kg of MUCAPE along/east of the I-95 corridor, so will have to watch that area in particular for severe potential. Already seeing a few of the stronger cells trying to tap into this shear and spin a little aloft. Will see how this evolves as this line pushes east. This is expected to gradually increase through the morning and push further up into northeast MD. Think this is where the greatest severe potential lies today. Given the impressive low- level shear and just enough CAPE, can't rule out an isolated tornado or some damaging wind gusts.
Think the worst of this system departs by late morning/early afternoon at the latest. However, lingering anafrontal showers will remain behind the front for several more hours into the evening perhaps for areas east of I-95. High pressure will then start to build into the region this afternoon into tonight, with dry conditions returning for all by the late afternoon/early evening. In the wake of the cold front, much cooler temperatures are expected overnight tonight, with lows dipping into the upper 40s to mid 50s (with lower values closer to 40 out west).
Short Term - Friday Through Saturday Night
Dry and seasonably cool on Friday with highs in the low to mid 70s as high pressure builds towards the region. This will continue into Friday night as well, with temps even a touch cooler than Thursday night.
Temps start to moderate a bit on Saturday as high pressure sets of to our southwest. Temperatures won't increase much, with highs closer to the mid 70s. With winds out of the southwest, temps overnight will trend upwards as well, increasing a few degrees compared to previous nights.
Long Term - Sunday Through Wednesday
High pressure will dominate over the region early next week with near or slightly below normal temperatures and dry conditions. Temperatures will moderate Tuesday as the aforementioned high shifts offshore and winds turning a touch more southerly. Tuesday will also feature our next chance of precipitation as a weak cold front drops southward toward the region. Latest guidance depicts scant moisture with this front, so will maintain low end chance POPs in the forecast for now. Cooler conditions return toward the middle of next behind the front as Canadian high pressure builds to our north.
Gale Warnings continue through the early afternoon for the lower Tidal Potomac and the Chesapeake Bay. A Small Craft Advisory remains in effect for the upper and middle Tidal Potomac. As a strong cold front continues to track eastward, gusty showers and thunderstorms are likely where the issuance of SMWs may be required, and even the potential for an isolated waterspout.
Northerly winds are expected to develop after the front moves through the region by Thursday afternoon and persist into Friday. Additional SCA (Small Craft Advisory) was issued to cover this threat starting late tonight. SCA (Small Craft Advisory) gusts possible in S channeling ahead of a front Satpm before becoming NW with SCA (Small Craft Advisory) gusts possible thru Sun.
Borderline SCA (Small Craft Advisory) conditions possible Sunday under a westerly wind regime as high pressure builds mainly south of the waters. The gradient will relax Sunday night into Monday with continued light westerly breezes.
Tides / Coastal Flooding
Tidal anomalies continue to run high thanks to strong onshore winds ahead of an approaching cold front. As a result, minor to moderate tidal flooding is occurring or forecast this morning at all tidal locations. Confidence in additional tidal flooding with subsequent high tide cycles this afternoon and evening decreases as winds will turn offshore as the front slowly crosses the area today. Additional updates to the forecast will certainly be needed later this morning as the timing of the front and wind shift becomes clearer, allowing anomalies to back off.
NOAA Baltimore MD/Washington DC Office: Watches - Warnings - Advisories
DC...Flash Flood Watch until 2pm EDT this afternoon for DCZ001. Coastal Flood Advisory until noon EDT today for DCZ001. MD...Flash Flood Watch until 2pm EDT this afternoon for MDZ005-006- 008-011-503>508. Flash Flood Watch until 8am EDT this morning for MDZ003-004. Coastal Flood Advisory until 8am EDT this morning for MDZ016. Coastal Flood Warning until 7am EDT this morning for MDZ017. Coastal Flood Advisory until 7am EDT this morning for MDZ018. Coastal Flood Advisory until 4pm EDT this afternoon for MDZ508. Coastal Flood Warning until noon EDT today for MDZ014. Coastal Flood Advisory until 2pm EDT this afternoon for MDZ011. VA...Flash Flood Watch until 2pm EDT this afternoon for VAZ053-054- 506. Flash Flood Watch until 8am EDT this morning for VAZ505. Coastal Flood Advisory until 8am EDT this morning for VAZ057. Coastal Flood Advisory until noon EDT today for VAZ054. WV...Flash Flood Watch until 8am EDT this morning for WVZ051>053.
Small Craft Advisory until 9pm EDT this evening for ANZ535- 536. Flash Flood Watch until 2pm EDT this afternoon for ANZ535. Small Craft Advisory from noon today to 5am EDT Friday for ANZ530>533-538>542. Gale Warning until noon EDT today for ANZ530>534-537>543. Small Craft Advisory from noon today to 10am EDT Friday for ANZ534-537-543.