Possible Severe Weather Outbreak

URGENT - WEATHER MESSAGE

National Weather Service Gray ME

1016 PM EDT Wed Jul 26 2023

MEZ018-019-023-024-NHZ007>015-271430-

/O.CON.KGYX.HT.Y.0002.230727T1500Z-230728T0000Z/

/O.CON.KGYX.HT.Y.0003.230728T1500Z-230729T0000Z/

Interior York-Central Interior Cumberland-Coastal York-Coastal

Cumberland-Sullivan-Merrimack-Belknap-Strafford-Cheshire-Eastern

Hillsborough-Interior Rockingham-Coastal Rockingham-Western And

Central Hillsborough-

Including the cities of Hollis, Alfred, Lebanon, Sanford, Goodwins

Mills, Buxton, Limington, Berwick, New Gloucester, Gray, North

Windham, Gorham, Biddeford, Saco, Old Orchard Beach, Kittery,

Portland, Cape Elizabeth, South Portland, Westbrook, Yarmouth,

Brunswick, Claremont, Cornish, Unity, Croydon, Goshen, Grantham,

Lempster, Newport, Charlestown, Boscawen, Canterbury, Concord,

Dunbarton, Loudon, Hooksett, Laconia, Gilford, Meredith, Barrington,

Rochester, Dover, Rollinsford, Somersworth, Durham, Madbury, Gilsum,

Keene, Marlow, Sullivan, Surry, Jaffrey, Manchester, Pelham, Nashua,

Salem, Atkinson, Newton, Plaistow, Chester, Derry, Hampstead,

Exeter, Greenland, Portsmouth, Rye, Hampton, Hampton Falls, North

Hampton, Seabrook, Amherst, Milford, Mont Vernon, Goffstown,

Peterborough, Sharon, and Weare

1016 PM EDT Wed Jul 26 2023

...HEAT ADVISORY REMAINS IN EFFECT FROM 11 AM TO 8 PM EDT THURSDAY...

...HEAT ADVISORY REMAINS IN EFFECT FROM 11 AM TO 8 PM EDT FRIDAY...

* WHAT...For the first Heat Advisory, heat index values up to 98

  expected. For the second Heat Advisory, heat index values up to 98

  expected.

* WHERE...Portions of southwest Maine. Portions of central and

  southern New Hampshire.

* WHEN...For the first Heat Advisory, from 11 AM to 8 PM EDT

  Thursday. For the second Heat Advisory, from 11 AM to 8 PM EDT

  Friday.

* IMPACTS...Hot temperatures and high humidity may cause heat

  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of

the sun, and check up on relatives and neighbors.

&&

$$

DS

Flood Watch

National Weather Service Gray ME

1014 PM EDT Wed Jul 26 2023

.A storm system will approach the region Thursday bringing another

chance for showers and thunderstorms with heavy rainfall. There is

the potential for storms to train or persist over the same area for

a period of time while producing torrential rainfall. With wet

ground conditions already in place, runoff will be rapid and capable

of producing flash flooding.

MEZ012-013-018>020-023>025-033-NHZ002>015-271415-

/O.CON.KGYX.FA.A.0017.230727T1600Z-230728T0100Z/

/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

Southern Oxford-Southern Franklin-Interior York-Central Interior

Cumberland-Androscoggin-Coastal York-Coastal Cumberland-Sagadahoc-

Interior Cumberland Highlands-Southern Coos-Northern Grafton-

Northern Carroll-Southern Grafton-Southern Carroll-Sullivan-

Merrimack-Belknap-Strafford-Cheshire-Eastern Hillsborough-

Interior Rockingham-Coastal Rockingham-Western And Central

Hillsborough-

Including the cities of Bethel, Bryant Pond, Hanover, Locke Mills,

Milton, Newry, Rumford, Norway, Fryeburg, Oxford, Farmington, New

Sharon, New Vineyard, Temple, Wilton, Chesterville, Jay, Hollis,

Alfred, Lebanon, Sanford, Goodwins Mills, Buxton, Limington,

Berwick, New Gloucester, Gray, North Windham, Gorham, Greene,

Lewiston, Sabattus, Wales, Minot, Turner, Auburn, Livermore Falls,

Biddeford, Saco, Old Orchard Beach, Kittery, Portland, Cape

Elizabeth, South Portland, Westbrook, Yarmouth, Brunswick, Arrowsic,

Bath, Phippsburg, Bowdoinham, Topsham, Bowdoin, Bridgton, Harrison,

Naples, Berlin, Dummer, Milan, York Pond, Lancaster, Bethlehem,

Lincoln, Littleton, Sugar Hill, Thornton, Waterville Valley,

Woodstock, Jackson, North Conway, Albany, Conway, Chatham, Crawford

Notch, Lyme, Ashland, Ellsworth, Holderness, Plymouth, Rumney,

Wakefield, Bridgewater, Brookfield, Ossipee, Tuftonboro, Wolfeboro,

Moultonborough, Claremont, Cornish, Unity, Croydon, Goshen,

Grantham, Lempster, Newport, Charlestown, Boscawen, Canterbury,

Concord, Dunbarton, Loudon, Hooksett, Laconia, Gilford, Meredith,

Barrington, Rochester, Dover, Rollinsford, Somersworth, Durham,

Madbury, Gilsum, Keene, Marlow, Sullivan, Surry, Jaffrey,

Manchester, Pelham, Nashua, Salem, Atkinson, Newton, Plaistow,

Chester, Derry, Hampstead, Exeter, Greenland, Portsmouth, Rye,

Hampton, Hampton Falls, North Hampton, Seabrook, Amherst, Milford,

Mont Vernon, Goffstown, Peterborough, Sharon, and Weare

1014 PM EDT Wed Jul 26 2023

...FLOOD WATCH REMAINS IN EFFECT FROM THURSDAY AFTERNOON THROUGH

THURSDAY EVENING...

* WHAT...Flooding caused by excessive rainfall continues to be

  possible.

* WHERE...Portions of Maine, including the following areas,

  Androscoggin, Central Interior Cumberland, Coastal Cumberland,

  Coastal York, Interior Cumberland Highlands, Interior York,

  Sagadahoc, Southern Franklin and Southern Oxford. Portions of New

  Hampshire, including the following areas, Belknap, Cheshire,

  Coastal Rockingham, Eastern Hillsborough, Interior Rockingham,

  Merrimack, Northern Carroll, Northern Grafton, Southern Carroll,

  Southern Coos, Southern Grafton, Strafford, Sullivan and Western

  And Central Hillsborough.

* WHEN...From Thursday afternoon through Thursday evening.

* IMPACTS...Excessive runoff may result in flooding of rivers,

  creeks, streams, and other low-lying and flood-prone locations.

* ADDITIONAL DETAILS...

  - Following morning showers and thunderstorms, additional

    scattered and strong thunderstorms will be capable of

    producing heavy rainfall in excess of 2 inches in an hour.

    Saturated soil conditions will cause rainfall to runoff into

    rivers and streams, which remain high.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor the latest forecast and be alert for possible

Flood Warnings. Those living in areas prone to flooding should be

prepared to take action should flooding develop.

&&

$$

DS

000

FXUS61 KCAR 270155

AFDCAR

Area Forecast Discussion

National Weather Service Caribou ME

955 PM EDT Wed Jul 26 2023

.SYNOPSIS...

High pressure shifts south of the area tonight. Low pressure

will cross the region Thursday night. Another cold front will

move through the area on Saturday, with high pressure returning

on Sunday. A weak cold front will cross the area on Monday.......

..........Thursday...

Main concern on Thursday is potential for severe storms and

heavy rainfall Downeast. Low pressure and an existing MCS will

be moving east out of the Great Lakes and into our region. We

will be on the far NE end of the activity, with really only

Downeast being impacted by this system. The big question is does

the low pressure center and MCS track far enough north to bring

us into the more unstable and higher shear air south of the low

pressure, or do we stay far enough north to where we just get

some rain on the north side of the system. Right now, think that

the severe threat will mainly be from Bar Harbor to Bangor and

mainly from straight line winds, with more stable air being

north and east of this area. Heavy rain threat does extend

further east to Eastport though. Opted not to issue a flash

flood watch because antecedent conditions are actually fairly

dry over Downeast, with the recent heavier downpours having been

west of our area. Still, can`t rule out some local nuisance

flooding. Again, will need to watch closely to make sure the

system doesn`t track any further north than most models

indicate, which would put us in a higher shear and more unstable

environment and more susceptible to damaging winds and isolated

tornadoes. The far north could be unstable enough for a few

storms, especially if the system passes far enough south and

some breaks in the clouds can form. Don`t expect any stronger

storms in the north, though.

Lowered high temps some for Thursday due to increased

cloud cover, with low to mid 80s. Breezy from the S/SW and

muggy.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...

A trough will be sliding through during the evening hours

bringing an end to the thunderstorm activity. A weak wave of

low pressure will slide overhead and track into New Brunswick

before midnight. Showers will end by midnight with patchy fog to

develop across the area with the moist boundary layer and

shallow inversion developing. Expect this to be the last full

state muggy night with low to mid 60s and near full saturation

at the surface. Friday will be the last hot and humid day in

this long stretch of incredible humidity for the month of July.

A cold front will be approaching from the northwest on Friday

with strong westerly flow aloft. A piece of the big heat dome

will push overhead with 925mb temps warming to between +20C

north and +24C south. This will result in highs in the mid 80s

across the north and 89-92F highs in the Highlands, Bangor

region to interior Downeast. Dew points will increase to between

67-70F across the Downeast and Bangor will result in Heat Index

values 93-95F. We are just short of Heat Index Advisory criteria

so opted to hold off issuing one for now. There remains

significant uncertainty with much of the model guidance slowing

the arrival of the cold front. Have opted to keep slight chance

thunderstorms mainly confined to the northern 1/2 of the CWA for

Friday afternoon. If any storm can develop it will work with

decent SBCAPE but mid level lapse rates will be poor and the

surface forcing will be delayed. That being said we will have

decent shear in the 35-45kt range so anything that can develop

may become robust.

Friday night the front will begin its very slow push southeast

through Maine. Intially overnight expecting winds to shift west

before going northwest across the northern 1/3rd of the CWA. The

drier air with 50s dew points works into the North Woods in the

evening and then into the Caribou to Houlton area by daybreak

Saturday. Central Highlands into the Downeast expecting another

muggy night with upper 60s and high humidity.

Saturday expecting the front to sink south as a wave of low

pressure develops along it. Expecting a mostly cloudy day except

across the far north where the drier air is well in place. Showers

to increase in the AM and will begin to decrease by late day as

the wave of low pressure tracks east. There remains uncertainty

where the front will be and how much activity over the area.

Took a blend of operational runs and NBM to get the front

cleared of the CWA by late day. Bringing a complete end of the

humidity across the CWA by evening with northern areas seeing

dew points into the upper 40s by sunset........

Hazardous Weather Outlook

National Weather Service Caribou ME

312 PM EDT Wed Jul 26 2023

MEZ010-015>017-029>031-271915-

Central Piscataquis-Southern Penobscot-Interior Hancock-

Central Washington-Coastal Hancock-Coastal Washington-

Southern Piscataquis-

312 PM EDT Wed Jul 26 2023

This Hazardous Weather Outlook is for Central Highlands Maine,

Coastal DownEast Maine, Interior DownEast Maine and Penobscot

Valley Maine.

.DAY ONE...This afternoon and tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

There is a marginal threat for severe thunderstorms on Thursday.

Storms may produce gusty winds and locally heavy rainfall Thursday

afternoon into early evening.

Heat indices could reach into the mid 90s on Friday.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather

conditions according to Standard Operating Procedures.

$$