Mesoscale Discussion 1366

Issued

Jul 27, 2021, 4:36 PM EDT (20:36 UTC)

Expired

Jul 27, 2021, 6:00 PM EDT

In force

84 min

Issued by

the Storm Prediction Center

Concerning

Severe thunderstorm watch 395...396

The Albany radar (KENX), 65 km from the middle of the area, began a volume at 20:41 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

943 
ACUS11 KWNS 272036
SWOMCD
SPC MCD 272036 
MAZ000-NHZ000-RIZ000-CTZ000-NYZ000-VTZ000-NJZ000-PAZ000-272200-

Mesoscale Discussion 1366
NWS Storm Prediction Center Norman OK
0336 PM CDT Tue Jul 27 2021

Areas affected...Eastern NY...Southern New England

Concerning...Severe Thunderstorm Watch 395...396...

Valid 272036Z - 272200Z

The severe weather threat for Severe Thunderstorm Watch 395, 396
continues.

SUMMARY...Severe potential continues across eastern NY and adjacent
southern New England. Current trends suggest some severe potential
may extend into far southeast NY, far northern NJ, and southern CT.
A watch may need to be considered.

DISCUSSION...Recent radar and satellite imagery show that the main
convective line extends from about 20 miles west of ALB
southwestward into far northeast PA (about 25 miles northeast of
IPT). Updraft strength and duration has varied within the this line,
likely as a result of somewhat modest instability. Estimated storm
motion within the southern end of the line is southeastward around
31 kt, which places it at the southern edge of Severe Thunderstorm
Watch 396 near 22Z. Given the current storm trends and the warm and
moist downstream air mass, some isolated severe threat may persist
into far southern NY and southern CT. Northern portion of the line
continues to move more eastward, with an estimated storm motion
closer to 35 kt. As with areas southwestward, the downstream air
mass is warm, moist, and modestly buoyant, suggesting severe
potential will continue downstream.

In addition to the convective line, some more discrete development
has occurred on the southern edge of a previously decayed cluster of
showers and thunderstorm. More discrete storm character has allowed
for stronger updrafts and a relatively greater chance for a strong
downburst.

..Mosier.. 07/27/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...GYX...BOX...BTV...OKX...ALY...PHI...BGM...

LAT...LON   43077442 43247395 43487267 43177131 42577081 41857096
            41377178 40757358 40887475 41727660 42497521 43077442

Mesoscale Discussions in New York, 2021Mesoscale Discussions in Connecticut, 2021Mesoscale Discussions in Massachusetts, 2021Every mesoscale discussion in 2021

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.