Tropical Depression Laura Approaches The Region

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WTNT33 KWNH 290252

TCPAT3

BULLETIN

Tropical Depression Laura Advisory Number  37

NWS Weather Prediction Center College Park MD   AL132020

1000 PM CDT Fri Aug 28 2020

...LAURA CONTINUING TO LOSE TROPICAL CHARACTERISTICS...

...FLOOD THREAT CONTINUES INTO SATURDAY...

...A FEW TORNADOES REMAIN POSSIBLE...

SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION

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LOCATION...37.7N 86.9W

ABOUT 250 MI...400 KM NE OF MEMPHIS TENNESSEE

ABOUT 110 MI...180 KM ENE OF PADUCAH KENTUCKY

MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H

PRESENT MOVEMENT...E OR 80 DEGREES AT 24 MPH...39 KM/H

MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES

WATCHES AND WARNINGS

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Flash Flood Watches are posted for portions of the Tennessee

Valley and Mid Atlantic.

No coastal watches or warnings in effect.

For storm information specific to your area, including possible

inland watches and warnings, please monitor products issued by your

local National Weather Service forecast office.

DISCUSSION AND OUTLOOK

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At 1000 PM CDT (0300 UTC), the center of Tropical Depression Laura

was located near latitude 37.7 North, longitude 86.9 West. The

depression is moving toward the east near 24 mph (39 km/h), and this

motion is expected to continue through the overnight.

Maximum sustained winds are near 30 mph (45 km/h) with higher gusts.

Eventually, the remains of Laura will cross the central

Appalachians Saturday, before becoming absorbed by an approaching

cold front that is forecast to move off the mid-Atlantic coastline

by late Saturday.

The estimated minimum central pressure is 1003 mb (29.62 inches).

HAZARDS AFFECTING LAND

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RAINFALL: Additional rainfall of 1 to 3 inches, with maximum

amounts to 5 inches forecast across western and central Kentucky

and Tennessee, and south into northern Alabama and Mississippi.

One to 2 inches, with isolated totals to 4 inches will be

possible over southern Louisiana, Mississippi, and

Alabama.

One to 3 inches possible over the central and southern Appalachians

and the mid-Atlantic states through Saturday.

This rainfall will continue to cause isolated flash and urban

flooding, and small streams and creeks to overflow their banks

across the aforementioned regions. Minor to moderate river flooding

is occurring or forecast in Louisiana, Arkansas, and northern

Mississippi.

WIND:  Gusty winds will accompany the tropical depression as it

moves along the Lower Ohio Valley through tonight.

TORNADOES:  A few tornadoes remain possible overnight, mainly over

the Tennessee Valley. The risk for a couple of tornadoes should

redevelop Saturday afternoon and evening over parts of the

mid-Atlantic from Virginia to North Carolina.

NEXT ADVISORY

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Next complete advisory at 400 AM CDT.

$$

Forecaster Wpc Forecaster

FORECAST POSITIONS AND MAX WINDS

INIT  29/0300Z 37.7N  86.9W   25 KT  30 MPH...INLAND

 12H  29/1200Z 38.2N  82.8W   25 KT  30 MPH...INLAND/REMNT LOW

 24H  30/0000Z 38.3N  74.8W   35 KT  40 MPH...INLAND/REMNT LOW

 36H  30/1200Z 38.5N  69.5W   35 KT  40 MPH...POST-TROP/INLAND

 48H  31/0000Z 41.5N  62.0W   35 KT  40 MPH...POST-TROP/EXTRATROP

 60H  31/1200Z 43.5N  53.4W   35 KT  40 MPH...POST-TROP/EXTRATROP

 72H  01/0000Z...POST-TROP/EXTRATROP

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FXUS61 KCAR 290118

AFDCAR

Area Forecast Discussion

National Weather Service Caribou ME

918 PM EDT Fri Aug 28 2020

.SYNOPSIS...

High pressure will cross the region overnight. Low pressure

will cross the region later Saturday into Sunday. High pressure

will build across the region Monday into Tuesday. A cold front

will approach Wednesday.

&&......

Previous discussion:

High pressure will cross the region tonight while low pressure

tracks east from the Great Lakes. After a mostly clear evening,

clouds will increase from southwest to northeast across the forecast

area overnight. The low will track east toward the forecast area

Saturday while drawing a warm front north across the Gulf of

Maine toward the Downeast coast late. Overrunning rain will

expand northeast across the forecast area Saturday, with

increasing isentropic lift to the north of the warm front. The

heavier rains Saturday will occur across Downeast areas where

moisture convergence and lift is better focused near the

approaching low and warm front. Have also included the chance

of afternoon thunderstorms across central and Downeast portions

of the forecast area. Moisture from the remnants of Laura will

also be drawn north toward Downeast regions where precipitable

water values approach 2 inches later Saturday. Across northern

areas, a steadier rain will develop during the afternoon. Low

temperatures tonight will be dependent on how rapidly the clouds

thicken. Skies should remain mostly clear across northern Maine

through much of the night along with light winds which will

support favorable radiational cooling conditions. Generally

expect low temperatures across northern areas to range from the

upper 30s to lower 40s tonight. However, locally colder mid 30s

are possible across the normally colder northwest valley

locations. Localized mid 30s could also occur in the normally

coldest valley and low lying locations across the remainder of

northern Maine. Localized patchy frost could occur in the

normally coldest areas across northern Maine later tonight.

High temperatures Saturday will range from the lower to mid 60s

north, to the mid 60s Downeast.

SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

Upr trof wl be digging into ern Quebec Sat evening while at the sfc

assoc sfc low wl be nr Montreal. Locally hvy rainfall wl hv come to

an end by that point, though moderate rain may continue acrs sern

areas as RRQ of H2 jet streak lifts thru Downeast thru about

midnight. Showers shut off pretty quickly as drier air works in fm

the west by late evening. Low-level moisture remains acrs the region

until drier dwpts are able to sneak in aft 12z. This leads to a

soupy airmass Sat night with patchy-areas of fog expected. Min temps

wl drop into the u40s acrs the northwest, closest to the drier air,

with nr 60s over Downeast.

Sunday wl feature just slightly warmer temps than Sat as little cold

air advection exists bhnd fropa with winds rmng out of the west. Upr

lvl low crosses the Crown Sun aftn and upr lvl cold pool wl lead to

chc showers onsetting drg the day. Low shifts to the northeast

overnight with showers coming to and end twd midnight Sun night.

Skies wl begin to clr late and depending on timing of clearing,

cannot rule out u30s in the North Woods with temps elsewhere

dropping into the 40s.

For Monday ridge wl be building in fm the west with mosunny skies

expected everywhere. Maxes wl be warmer than Sun`s with mid-60s acrs

nrn areas and continuing nr 70 over Downeast.....

9:53 PM ADT Friday 28 August 2020

Special weather statement in effect for:

Halifax Metro and Halifax County West

Total rainfall: 30 to 40 mm except locally higher amounts possibly reaching 60 mm.

Locations: Nova Scotia, particularly southwestern regions as well as areas along the Atlantic Coast.

Time span: Saturday night until Sunday afternoon.

Remarks: Rain is expected to begin early Saturday night and may become heavy, at times, especially over southwestern regions and areas along the Atlantic Coast. The rain will taper off later in the day on Sunday.

Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to NSstorm@canada.ca or tweet reports using #NSStorm.