»

Boston/Norton MA Field Office

FXUS61 KBOX 072320

Forecasters: BW, KP, KJC

Active Alerts: Warning Advisory
Local Alerts: (Western Plymouth, Eastern Plymouth, Southern Plymouth)
Snow is coming to an end for eastern MA in the next 2-5 hours after some hyper localized snowfall this morning. Parts of northeast MA and southern RI where received around 12 and 9 inches respectively. Expected snow amounts have been lowered for the south shore of MA, while there have been no significant changes to the forecast dangerously cold wind chills tonight.
1 Key Message 1
After some hyper localized snowfall this morning, snow tapers off through 7pm except for Cape Cod and Nantucket where ocean effect snow continues overnight.
2 Key Message 2
Dangerous cold tonight into Sunday. Gusty winds produce wind chills as cold as 10 to 30 degrees below zero. High confidence in hazardous freezing spray over the waters.
3 Key Message 3
Quiet to start next week then another disturbance could bring unsettled weather mid to late week.
Key Message 1... After some hyper localized snowfall this morning, snow tapers off through 7pm except for Cape Cod and Nantucket where ocean effect snow continues overnight.

Well the very dynamic system we expected has lived up to expectations with hyper localized maxima over northeast MA and southern RI. A small strip in Essex county has received over a foot of snow while the immediate coast of RI received 8 inches by 10 am. The combination of mesoscale banding from surface convergence associated with the inverted trough, the arctic front, and ocean effect enhancement will continue to drop light to moderate snow for locations generally east of Worcester through 4-7 PM dropping an additional 1 to 3 inches between 1 PM and 7PM. The only place expected to see snow continue beyond around 7pm is Cape Cod and Nantucket where the favorable wind trajectory will lead to continued ocean effect showers through midnight, and even off and on through mid day Sunday. By the time all is said and 2 to 4 inches of snow is likely on Cape Cod with even some localized amounts over 4 inches.

Key Message 2... Dangerous cold tonight into Sunday. Gusty winds produce wind chills as cold as 10 to 30 degrees below zero. High confidence in hazardous freezing spray over the waters.

We continue to have high confidence that today's arctic front ushers in an anomalously cold airmass (925 mb temps as cold as -16°C (3°F)), accompanied by a strong LLJ (40-45 kts at 925mb), 30-40mph of which should mix down as strong gusts this evening into the overnight hours. The combination of strong winds and cold air will lead to dangerous wind chill temperatures on the order of -10 to -15F in eastern MA/RI and between -15 and -30 F in the highest elevations of the Worcester Hills and Berkshires. While these temperatures will bottom out around 7 am (with actual temps in the single digits +/- 0F) it will be a slow warm up, never feeling above the single digits during the afternoon. Some locations may not crack a wind chill above zero.

Key Message 3... Quiet to start next week then another disturbance could bring unsettled weather mid to late week.

The distant offshore low to our southeast continues its way out to sea for the start of the week and high pressure over the eastern Great Lakes builds in. Gusty winds from 20 to 30 mph persist through Sunday before the pressure gradient starts to weaken, and high pressure takes control of the pattern over southern New England Monday into Tuesday. Dry conditions make a return with continued below-normal temperatures, though Wednesday could see highs in the mid 30s. These are still below normal, but may feel much warmer than what we've dealt with lately.

We are continuing to monitor another possible system that could impact southern New England sometime midweek. Latest guidance still doesn't have a solid grasp on track or exact timing, which is not expected this far out. But generally, 925 mb temperatures could climb to around -5°C (23°F) and even 0°C (32°F) by Wednesday morning. A low from the NW may cross over the northeast that could lead to showers across southern New England. But again, it is too far out to know for certain and much can and will change between now and then.
CT: Extreme Cold Warning until 1 PM EST Sunday for CTZ002>004.

MA: Extreme Cold Warning until 1 PM EST Sunday for MAZ002>004-008>012. Winter Weather Advisory until 7 PM EST this evening for MAZ004-005-012>021-026. Cold Weather Advisory until 1 PM EST Sunday for MAZ005>007-013>023-026. Winter Storm Warning until 7 PM EST this evening for MAZ006-007. Winter Weather Advisory until 1 AM EST Sunday for MAZ022>024.

RI: Winter Weather Advisory until 7 PM EST this evening for RIZ001>008. Cold Weather Advisory until 1 PM EST Sunday for RIZ001>008.

MARINE: Gale Warning until 7 AM EST Sunday for ANZ230-236. Freezing Spray Advisory until 7 PM EST Sunday for ANZ230. Gale Warning until 1 PM EST Sunday for ANZ231-232-250-251-254>256. Heavy Freezing Spray Warning until 7 AM EST Monday for ANZ231>237-250-251-254>256. Gale Warning until 10 AM EST Sunday for ANZ233>235-237.

j/k prev/next day | / prev/next issuance | Ctrl+E expand/collapse all