Flash Flood Warning 5, NWS Gray, ME

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
707 AM EDT THU JUL 2 2009

.SYNOPSIS...
A UPPER LEVEL LOW PRESSURE SYSTEM ACROSS THE GREAT LAKES WILL
REMAIN NEARLY STATIONARY TONIGHT AND FRIDAY. THE LOW WILL
GRADUALLY MOVE SOUTHEAST ACROSS THE AREA SATURDAY AND THEN EAST OF
THE REGION SUNDAY. AN UPPER TROUGH WILL LIKELY DEVELOP ACROSS THE
AREA BY EARLY NEXT WEEK MARKING A RETURN TO COOLER AND
INCREASINGLY UNSETTLED WEATHER.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...
THROUGH 600 AM...WATER VAPOR SHOWS A SHORTWAVE ENTERING SOUTHERN
NEW ENGLAND AS IT PIVOTS AROUND AN UPPER LOW ACROSS THE GREAT
LAKES. THIS APPEARS TO BE THE SPARK FOR SHOWERS AND THUNDERSTORMS
ENTERING THE SAME REGION. CONVECTION IS ONCE AGAIN ELEVATED...WITH
THE 06Z GFS SHOWING BEST LI/S OF -1 TO -3 NEAR BOSTON...THEN
BECOMING MORE STABLE EAST OF PORTLAND. 06Z NAM BUFKIT PAINTS A
SIMILAR PICTURE...WITH ELEVATED CAPES DROPPING OFF NORTH OF LEB-
PWM. MUCH AS HAPPENED YESTERDAY...CONVECTION SHOULD FLATTEN AND
DIMINISH IN INTENSITY AS IT MOVES INTO MORE STABLE REGIONS TODAY.

RADAR ONCE AGAIN SHOWS SHOWERS AND THUNDERSTORMS TRAINING...THIS
TIME IN EASTERN CONNECTICUT. WHILE THE 00Z GFS/NAM DID NOT HAVE A
GOOD HANDLE ON THE SHORTWAVE...AND THUS QPFS WERE SUSPECT...THE
06Z RUNS APPEAR TO MATCH OBSERVATIONS MUCH BETTER. EACH NOW
CAPTURE THE ONGOING CONVECTION...AND DIMINISH IT AS THE SHORTWAVE
MOVES FURTHER NORTH WHERE THERE IS LESS ELEVATED CAPE. WHILE
PREVIOUS FORECAST ATTEMPTED TO SHOW A SIMILAR TREND...WAS ABLE TO
NUDGE TOWARDS THE 06Z RUNS...BETTER FOCUSING THE HIGHEST QPF
ACROSS SOUTHEASTERN NEW HAMPSHIRE AND FAR SOUTHERN MAINE.

FOCUS THIS MORNING WILL CONTINUE TO BE IN SOUTHEASTERN NEW
HAMPSHIRE...WHERE THE REMNANTS OF THE MOISTURE TRAINING INTO
CONNECTICUT WILL TRACK. SEE HYDROLOGY SECTION FOR MORE ON THE
POTENTIAL FOR FLOODING.

THE WATER VAPOR DOES NOT SHOW ANY ADDITIONAL SHORTWAVES...
SUGGESTING CONVECTION THIS AFTERNOON MAY LARGELY BE LIMITED TO
DAYTIME HEATING. YESTERDAY...STRATUS STAYED IN PLACE ACROSS ALMOST
THE ENTIRE CWA...WITH SIMILAR EXPECTATIONS FOR TODAY.
HOWEVER...COULD SEE BREAKS ON THE FRINGES (AS OCCURRED
TUESDAY)...SO WILL INCLUDE A MENTION OF AFTERNOON THUNDERSTORMS IN
WESTERN NEW HAMPSHIRE. NAM/GFS BUFKIT CONTINUE TO SHOW LONG-THIN
ELEVATED CAPES...SO WILL HOLD ONTO CHANCE POPS FOR THE REMAINDER
OF THE CWA.

USE A BLEND OF NAM MOS AND YESTERDAY/S HIGHS FOR THE HIGH
TEMPERATURE FORECAST. THE GFS SEEMS (AND HAS BEEN) TOO WARM.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM FRIDAY/...
THE FOCUS FOR PRECIPITATION TONIGHT...SEEMS THE SURFACE TROF
ITSELF. HERE...FEEL MODELS DO A FAIRLY GOOD JOB KEYING IN ON
THIS...WITH A LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS LIKELY
LIFTING ACROSS THIS EVENING. GENERALLY EXPECT RAINFALL AMOUNTS
TONIGHT TO RUN FROM .25 TO .50...WITH LOCALLY HIGHER AMOUNTS. THE
FEATURE WILL LIFT FROM SOUTH TO NORTH...WITH POPS FOLLOWING THAT
TREND. IT APPEARS THE BEST CHANCE FOR HEAVY RAIN...IS TO THE
WEST TONIGHT.

EXPECT FOG TO ONCE AGAIN THICKEN AHEAD OF AND ALONG THIS BOUNDARY.
TEMPERATURES WILL AGAIN VARY LITTLE...STRUGGLING TO DROP AT ALL
AS THE BOUNDARY MOVES THROUGH.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
CHANGES ARE COMING TO THE 500MB PATTERN...AND ALTHOUGH MODELS VARY
SOMEWHAT AS TO EXACTLY HOW THOSE CHANGES PAN OUT...IT LOOKS LIKE
THERE WILL BE SOME LEVEL OF IMPROVEMENT OVER THE WEEKEND AND INTO
THE THE FIRST HALF OF NEXT WEEK.

FOR FRI/SAT...WE WILL STILL BE DEALING WITH THE 500MB CLOSED LOW
THAT HAS BEEN THE SOURCE OF ALL THE MISERABLE WX DURING THIS
WEEK...BUT IT WILL FINALLY ON THE MOVE...AS TWO WAVES DIG INTO ITS
TROUGH...AND BEGIN TO SHIFT IT EAST ACROSS NRN NEW ENGLAND. FIRST
WAVE ACTUALLY ROTATES OUT OF BASE TROUGH EARLY FRI MORNING...AND
THIS WILL SHIFT LOW-MID LVL FLOW TO THE SW...WHICH IS EXPECTED TO
BRING AN END TO THE PERSISTENT ONSHORE FLOW. THIS WILL ALLOW FOR
SOME CLEARING...EVEN ON THE COAST BY FRIDAY AFTERNOON.
HOWEVER...COOL AIR ALOFT AND SUNSHINE AT THE SFC WILL LEAD TO
INSTABILITY...AND THE THREAT OF CONVECTION. SOME DRIER AIR IS
EXPECTED TO SHIFT IN BEHIND THIS EAVE AS WELL...WHICH WILL HELP TO
MINIMIZE THE HEAVY RAIN SOMEWHAT...BUT NOT COMPLETELY...AS UPPER
LVL FLOW CONTINUES TO REMAIN LIGHT...WITH CLOSED LOW STILL JUST
OUR WEST. SHOULD SEE A BIT OF A BREAK LATE FRI NIGHT...THEN 500MB
LOW AND COLD CORE ALOFT MOVE OVER CWA ON SAT. HOWEVER...LOW-MID
FLOW BECOMES W...WHICH SHOULD ALLOW FOR SOME SUNSHINE IN DOWNSLOPE
AREAS...WITH MORE CLOUDS IN THE MOUNTAINS. CONVECTION WILL ONCE
AGAIN BE A THREAT...BUT SHOULD BE MORE WIDELY SCATTERED ON THE
COASTAL PLAIN GIVEN THE WESTERLY FLOW. MORE CLOUDS AND A BETTER
CHC FOR SHRA IN THE MTNS.

500MB CLOSED LOW MOVES OVER THE MARITIMES ON SUN...AND THE MTNS
WILL LKLY BE DEALING WITH SOME WRAPAROUND MOISTURE IN THE FORM OF
SCT SHRA. TO THE SOUTH IT LOOKS MAINLY DRY WITH SCT CLOUDS. DURING THE
FIRST HALF OF NEXT WEEK THE FLOW LOOKS TO TRANSITION TO
NW...ZONAL...OR EVEN RIDGING BY MID-WEEK...DEPENDING ON WHICH
MODEL YOU CHOOSE. STILL...ALL POINT TO A PROLONGED PERIOD OF FLOW
WITH A WESTERLY COMPONENT...WHICH WOULD PREVENT ANY ONSHORE FLOW
OTHER THAN SEA BREEZE. SO...WHILE THERE MAY BE SOME UNSETTLED
PERIODS...THERE WILL ALSO BE SOME SUNSHINE AND WARMER TEMPS.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
SHORT TERM...AGAIN TREND TOWARDS PESSIMISTIC END OF
GUIDANCE...WITH GOOD CONFIDENCE THAT STRATUS WILL REMAIN IN PLACE
THROUGH TONIGHT AT CON-PSM-PWM-AUG. BREAKS AN/OR LIFTING ARE
POSSIBLE AT LEB. VSBY A BIT MORE TRICKY...WITH LOWEST VSBY ALONG
THE COAST...BUT IN GENERAL IT HAS BEEN VERY SENSITIVE TO SUBTLE
FEATURES. GENERALLY EXPECT VSBY TO RISE DURING THE DAYTIME
HOURS...WITH SOME VARIATIONS LIKELY.

AT CON-PWM-PSM-AUG FEEL THERE IS A CHANCE OF THUNDERSTORMS THIS
MORNING EMBEDDED IN CONVECTION...BUT THIS CHANCE FOR ANY
PARTICULAR SITE IS STILL RELATIVELY SMALL. WILL MONITOR AND ADJUST
AS CONFIDENCE IN UPSTREAM CONVECTION GROWS. LEB MAY SEE AN
AFTERNOON -TSRA...BUT AGAIN CHANCES TOO LOW FOR A MENTION AT THIS
TIME.

FOR TONIGHT...EXPECT VSBY TO DROP ALONG THE BOUNDARY...WITH
PERHAPS A PERIOD OF 1/4SM VSBY AT SEVERAL SITES. UNCERTAIN IN
TIMING...AND SHOWER ACTIVITY...SO TAFS NOT QUITE AS PESSIMISTIC
HERE...BUT A 3 - 6 HR PERIOD OF 1/4SM VSBY IS POSSIBLE TONIGHT
WITH THAT FEATURE.

LONG TERM...ALL IN ALL EXPECTING IMPROVE TO VFR AT
ALL TERMINALS DURING THE DAY ON FRI...HOWEVER SCT TSRA ARE
POSSIBLE FRI AFT/EVE. AFTER THAT SHOULD BE MAINLY VFR THRU THE
WEEKEND.

&&

.MARINE...
SHORT TERM...NO HEADLINES...THOUGH DID NOTE ISLES OF SHOALS WAS
RUNNING ABOVE BOTH MOS AND MODEL DATA FOR ITS WINDS. THUS WENT
ABOVE GUIDANCE IN THE NE FLOW...WHICH STILL KEEPS WINDS BELOW SCA.
SEAS MAY APPROACH 5 FT OFF THE NH COAST...BUT KEEP SEAS SUB-SCA.

LONG TERM...SEAS TO NEAR 5 FT WILL LINGER INTO FRI...AND
WIDESPREAD FOG WILL PROBABLY NOT TO BEGIN TO BREAK UP UNTIL FRI
AFTERNOON...BUT SEAS DIMINISH FRI NIGHT...WITH IMPROVED CONDITIONS
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK.

&&

.HYDROLOGY...
RAINFALL AMOUNTS WILL VARY GREATLY BY LOCATION...WITH LOCALIZED
HEAVY RAIN A POSSIBILITY TODAY AND TONIGHT.

THE GREATEST CHANCE FOR HEAVY RAIN TODAY APPEARS TO BE ACROSS
SOUTHEASTERN NEW HAMPSHIRE. THE CONCERN IS IF SHOWERS AND
THUNDERSTORMS FOCUS ON ONE AREA. FOLLOWING RADAR TRENDS
UPSTREAM...AM CONCERNED THAT STORMS TRAINING INTO EASTERN
CONNECTICUT WILL EVENTUALLY MAKE IT INTO SOUTHEASTERN NEW
HAMPSHIRE AND FAR SOUTHERN MAINE...PROMPTING THE FLASH FLOOD
WATCH. LOCALIZED RAINFALL AMOUNTS IN EXCESS OF TWO INCHES ARE
POSSIBLE IN THE WATCH AREA. IN GENERAL...RAINFALL AMOUNTS IN
EXCESS OF TWO INCHES WOULD PUT STREAMS AND SOME RIVER BASINS CLOSE
TO BANKFULL.

FOR TONIGHT...ANOTHER ROUND OF PRECIPITATION IS EXPECTED TO MOVE
ACROSS THE REGION. THIS WILL PRESENT SIMILAR CONCERNS...THOUGH THE
HEAVIEST RAIN APPEARS TO BE MORE LIKELY TO THE WEST.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...FLASH FLOOD WATCH UNTIL 5 PM EDT THIS AFTERNOON FOR MEZ018-023.
NH...FLASH FLOOD WATCH UNTIL 5 PM EDT THIS AFTERNOON FOR NHZ006-
     008>010-013-014.
MARINE...NONE.

&&

SYNOPSIS...
NEAR TERM...APFFEL
SHORT TERM...APFFEL
LONG TERM...CEMPA
AVIATION...APFFEL
MARINE...APFFEL/CEMPA
HYDROLOGY...APFFEL

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE GRAY ME
707 AM EDT THU JUL 2 2009

ANZ153-MEZ007>009-012>014-019>022-024>028-NHZ001>005-007-031115-
CASCO BAY-NORTHERN OXFORD-NORTHERN FRANKLIN-CENTRAL SOMERSET-
SOUTHERN OXFORD-SOUTHERN FRANKLIN-SOUTHERN SOMERSET-
INTERIOR CUMBERLAND-ANDROSCOGGIN-KENNEBEC-INTERIOR WALDO-
COASTAL CUMBERLAND-SAGADAHOC-LINCOLN-KNOX-COASTAL WALDO-
NORTHERN COOS-SOUTHERN COOS-NORTHERN GRAFTON-NORTHERN CARROLL-
SOUTHERN GRAFTON-SULLIVAN-
707 AM EDT THU JUL 2 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CASCO BAY...WESTERN
MAINE...CENTRAL NEW HAMPSHIRE AND NORTHERN NEW HAMPSHIRE.

.DAY ONE...TODAY AND TONIGHT

THE GREATEST CHANCE FOR HEAVY RAIN TODAY APPEARS TO BE ACROSS
SOUTHEASTERN NEW HAMPSHIRE AND FAR SOUTHERN MAINE. THE CONCERN IS IF
SHOWERS AND THUNDERSTORMS FOCUS ON ONE AREA. AT THIS TIME...THE
HEAVIEST RAIN IS MOST LIKELY TO FALL ACROSS SOUTHEASTERN NEW
HAMPSHIRE...AND POINTS SOUTH. THEREFORE...DO NOT HAVE THE
CONFIDENCE TO ISSUE A FLOOD WATCH OUTSIDE OF THAT AREA. IF
EXPECTATIONS CHANGE...A FLOOD WATCH...AND/OR FLOOD WARNINGS MAY BE
NEEDED.

FOR TONIGHT...ANOTHER ROUND OF PRECIPITATION IS EXPECTED TO MOVE
ACROSS THE REGION. THIS WILL PRESENT SIMILAR CONCERNS...THOUGH THE
HEAVIEST RAIN APPEARS TO BE MORE LIKELY TO THE WEST.

IN GENERAL...RAINFALL AMOUNTS IN EXCESS OF TWO INCHES WOULD PUT
STREAMS AND SOME RIVER BASINS CLOSE TO BANKFULL.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

ALTHOUGH SOME DRIER AIR WILL WORK IN FOR FRIDAY...REDUCING THE
THREAT FOR HEAVY RAINFALL...THERE IS STILL IS A POSSIBILITY THAT
BACK BUILDING STORMS COULD PRODUCE LOCALIZED HEAVY RAINFALL. ALSO
SOME STORMS COULD PRODUCE SMALL HAIL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

MEZ018-023-NHZ006-008>010-013-014-031115-
INTERIOR YORK-COASTAL YORK-SOUTHERN CARROLL-MERRIMACK-BELKNAP-
STRAFFORD-INTERIOR ROCKINGHAM-COASTAL ROCKINGHAM-
707 AM EDT THU JUL 2 2009

...FLASH FLOOD WATCH IN EFFECT UNTIL 5 PM EDT THIS AFTERNOON...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN MAINE...CENTRAL NEW
HAMPSHIRE...NORTHERN NEW HAMPSHIRE AND SOUTHEASTERN NEW HAMPSHIRE.

.DAY ONE...TODAY AND TONIGHT

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   FLASH FLOOD WATCH.

THE GREATEST CHANCE FOR HEAVY RAIN TODAY APPEARS TO BE ACROSS
SOUTHEASTERN NEW HAMPSHIRE AND FAR SOUTHERN MAINE. THE CONCERN IS IF
SHOWERS AND THUNDERSTORMS FOCUS ON ONE AREA. RAINFALL TOTALS IN
EXCESS OF TWO INCHES ARE POSSIBLE IN THE WATCH AREA.

FOR TONIGHT...ANOTHER ROUND OF PRECIPITATION IS EXPECTED TO MOVE
ACROSS THE REGION. THIS WILL PRESENT SIMILAR CONCERNS...THOUGH THE
HEAVIEST RAIN APPEARS TO BE MORE LIKELY TO THE WEST.

IN GENERAL...RAINFALL AMOUNTS IN EXCESS OF TWO INCHES WOULD PUT
STREAMS AND SOME RIVER BASINS CLOSE TO BANKFULL.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

ALTHOUGH SOME DRIER AIR WILL WORK IN FOR FRIDAY...REDUCING THE
THREAT FOR HEAVY RAINFALL...THERE IS STILL IS A POSSIBILITY THAT
BACK BUILDING STORMS COULD PRODUCE LOCALIZED HEAVY RAINFALL. ALSO
SOME STORMS COULD PRODUCE SMALL HAIL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

ANZ150>152-154-031115-
STONINGTON ME TO PORT CLYDE ME OUT TO 25 NM-PENOBSCOT BAY-
PORT CLYDE ME TO CAPE ELIZABETH ME OUT TO 25 NM-
CAPE ELIZABETH ME TO MERRIMACK RIVER MA OUT TO 25 NM-
707 AM EDT THU JUL 2 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PENOBSCOT BAY...THE COASTAL
WATERS FROM CAPE ELIZABETH ME TO MERRIMACK RIVER MA...THE COASTAL
WATERS FROM PORT CLYDE ME TO CAPE ELIZABETH ME AND THE COASTAL
WATERS FROM STONINGTON ME TO PORT CLYDE ME.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.