Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/27/14
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
820 PM MST FRI SEP 26 2014
...SEVERE WEATHER THREAT OVER SOUTH-CENTRAL ARIZONA FROM LATE
MORNING INTO THE EVENING HOURS ON SATURDAY...
.SYNOPSIS...
A STRONG PACIFIC STORM IS FORECAST TO MOVE THROUGH THE REGION ON
SATURDAY. THIS STORM...COMBINED WITH AMPLE LEFTOVER MONSOON
MOISTURE...IS EXPECTED TO PRODUCE WIDESPREAD SHOWER AND THUNDERSTORM
ACTIVITY ACROSS THE REGION. SOME OF THE STRONGER STORMS WILL BE
CAPABLE OF PRODUCING LOCALLY STRONG...EVEN DAMAGING WINDS...HEAVY
RAIN...AND HAIL. AFTER A COLD FRONTAL PASSAGE SATURDAY NIGHT...DRIER
WEATHER WITH BELOW NORMAL TEMPERATURES ARE FORECAST TO SPREAD
EASTWARD OVER THE REGION FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...
CONVECTION HAS LARGELY DIED OFF ACROSS THE DESERTS THIS EVENING AND
HAS SINCE SHIFTED NORTHWARD INTO ARIZONA AND NEVADA. RADAR AND
SATELLITE TRENDS INDICATE NEW ISOLATED CONVECTION IS BEGINNING TO
FORM ACROSS EASTERN ARIZONA...ALONG THE COLORADO RIVER...AND SOUTH
OF YUMA OVER SONORA IN AN AREA OF LEFTOVER ELEVATED INSTABILITY.
THE UPPER LOW FORECAST TO MOVE THROUGH THE REGION ON SATURDAY AND
ITS ASSOCIATED FORCING AND SHEAR REMAIN WELL TO OUR WEST THIS
EVENING...STILL LOCATED OVER CENTRAL CALIFORNIA AS OF 03Z.
CONVECTION IS STILL EXPECTED TO DEVELOP LATE TONIGHT/EARLY SATURDAY
MORNING WITH THE PRIMARY FOCUS ALONG THE LOWER COLORADO RIVER...THEN
TRANSITION EASTWARD INTO THE PHOENIX AREA DURING THE DAY ON
SATURDAY. THE INCOMING 00Z MODELS ARE STILL ON TRACK AND NO MAJOR
CHANGES WERE MADE TO THE FORECAST. ONLY NOTEWORTHY REVISIONS WERE A
SLIGHT REDUCTION IN POPS FOR THE REST OF THIS EVENING WITH ACTIVITY
PICKING UP ONCE AGAIN AFTER MIDNIGHT. HRRR SEEMS TO BE HANDLING THE
PRESENT SITUATION THE BEST OF ANY OPERATIONAL MODEL AND WAS LEANED
UPON HEAVILY FOR THE REST OF THE EVENING/OVERNIGHT HOURS.
&&
.PREVIOUS DISCUSSION...
SATURDAY...
THE MAIN EVENT...WHICH IS A STRONG PACIFIC LOW CENTER...IS STILL
EXPECTED TO BEGIN TO IMPACT OUR CWA BEGINNING LATE TONIGHT...THEN
CONTINUE INTO EARLY SUNDAY. THE COMBINATION OF A VERY RICH MOISTURE
ENVIRONMENT AND STRONG VERTICAL WIND SHEAR THROUGH THE COLUMN...WITH
SFC-6KM BULK SHEAR VALUES OF UP TO 50KTS IS EXPECTED TO GENERATE
WIDESPREAD THUNDERSTORM ACTIVITY ACROSS THE WESTERN PORTION OF OUR
CWA LATE TONIGHT...MAINLY ACROSS THE CO RIVER VALLEY AND OVER LA PAZ
COUNTY. THE MAIN ISSUE WITH THESE STORMS WILL AGAIN BE HEAVY RAIN
AND GUST WINDS...AND LOCAL FLOODING.
DEVELOPING STORM DYNAMICS...WITH INCREASING MONSOON MOISTURE ARE
THEN EXPECTED TO BE STRONGEST OVER SOUTH CENTRAL AZ...INCLUDING
PHOENIX...FROM LATE MORNING THROUGH THE MID-EVENING HOURS ON
SATURDAY...WITH THE STORM PREDICTION CENTER KEEPING SOUTH-CENTRAL AZ
IN A SLIGHT RISK AREA FOR SEVERE THUNDERSTORMS. AGAIN...THE
COMBINATION OF FAVORABLE DIFLUENT FLOW...SFC-6KM BULK SHEAR VALUES
AS HIGH AS 50KTS...AND FAVORABLE TIME-OF-DAY...DURING THE AFTERNOON
HOURS...IS EXPECTED TO MAXIMIZE THE POTENTIAL FOR ORGANIZED SEVERE
STORM ACTIVITY. THE MAIN THREATS WILL BE HEAVY RAIN AND LARGE HAIL.
ALTHOUGH AN ISOLATED TORNADO IS POSSIBLE WITH THE STRONGEST
CONVECTION...THERE IS NOT A GREAT DEAL OF DIRECTIONAL SHEAR THROUGH
THE COLUMN...WHICH SHOULD MINIMIZE THE TORNADO THREAT...WITH LARGE
HAIL AND DAMAGING WINDS BEING THE MAIN THREATS.
SOME COMPARISONS HAVE ALREADY BEEN MADE BETWEEN THIS UPCOMING EVENT
AND THE ONE THAT OCCURRED BACK ON 05 OCT 2010...WHICH BROUGHT SEVERE
HAIL...UP TO 3 INCHES IN DIAMETER...HEAVY RAIN AND STRONG WINDS TO
THE GREATER PHOENIX AREA. ALTHOUGH THE OVERALL UPPER AIR PATTERNS
APPEAR TO BE SIMILAR FOR BOTH EVENTS...THE OCT 2010 EVENT HAD COLDER
AIR AT THE MID-LEVELS TO WORK WITH...500MB TEMPS DURING THAT EVENT
WERE AROUND -14C...WHILE 500MB TEMPS ON SATURDAY ARE EXPECTED TO BE
AROUND -9C. THE PARENT UPPER LOW CENTER DURING THE 2010 EVENT ALSO
TRACKED A BIT FURTHER TO THE SOUTH...FROM PALMDALE CA TO LAS
VEGAS...THEN INTO SOUTH-CENTRAL UT. THIS EVENT IS TAKING THE UPPER
LOW CENTER FROM THE SFO BAY AREA ESE-WARD ACROSS SOUTH-CENTRAL
NV...THEN INTO SOUTHERN UT. ON THE OTHER HAND...SATURDAY/S EVENT
LOOKS LIKE IT WILL HAVE MORE AVAILABLE MOISTURE...WITH PWATS IN THE
1.50-1.75 INCH RANGE...AS COMPARED TO AMOUNTS IN THE 1.25-1.50 INCH
DURING THE 2010 EVENT.
SHOWER/THUNDERSTORM ACTIVITY IS THEN EXPECTED TO RAPIDLY DIMINISH
SATURDAY NIGHT ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL ARIZONA AS
THE SFC FRONT PASSES THOUGH AND DRIER AIR WORKS ITS WAY IN FROM THE
WEST. ISOLATED TO SCATTERED SHOWER ACTIVITY WILL LIKELY LINGER INTO
SUNDAY OVER THE HIGHER TERRAIN OF SOUTHERN GILA COUNTY DUE TO LOCAL
UPSLOPE FLOW AND ANOTHER WEAK DISTURBANCE MOVING THROUGH THE REGION.
MONDAY THROUGH THURSDAY...
DRY WEATHER WITH NEAR...TO SLIGHTLY BELOW SEASONAL TEMPERATURES ARE
EXPECTED ACROSS THE ENTIRE FORECAST AREA.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
SHOWERS HAVE DIED OFF AS OF 03Z BUT WILL REDEVELOP OVERNIGHT.
CONFIDENCE IN EXACTLY WHERE/WHEN STORMS WILL FORM IS LOW BUT SUFFICE
TO SAY THAT ANY STORMS THAT DEVELOP DURING THE DAY ON SATURDAY WILL
BE MORE THAN CAPABLE OF PRODUCING STRONG WINDS AND IMPACTING THE
TERMINALS. STORMS WILL BE MOST LIKELY ACROSS THE WESTERN TERMINALS
OVERNIGHT...SHIFTING EASTWARD INTO THE PHOENIX METRO SATURDAY
MORNING/AFTERNOON. ACTIVITY WILL QUIET DOWN SATURDAY EVENING AS THE
UPPER LOW EXITS THE AREA.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
DRIER AIR WILL BEGIN MOVING INTO THE AREA ON MONDAY...WITH LITTLE TO
NO CHANCE OF CONVECTION THE REMAINING PORTION OF THE FORECAST
PERIOD. MINIMUM HUMIDITY LEVELS WILL TREND DOWN TO AROUND 15 PERCENT
BY THURSDAY. IN ADDITION TO THE DRIER AIR...COOLER TEMPERATURES ARE
EXPECTED THE ENTIRE PERIOD. SOME GUSTY WEST TO SOUTHWEST WINDS ARE
POSSIBLE ALONG AND BEHIND THE TROUGH EARLY SUNDAY...ALTHOUGH WIND
SPEEDS WILL BE GENERALLY LIGHT AND FOLLOW TYPICAL DIURNAL PATTERNS
MONDAY THROUGH THURSDAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS/PERCHA
AVIATION...LEINS
FIRE WEATHER...MEYERS/MCLANE
AREA FORECAST DISCUSSION...CORRECTION
NWS PHOENIX AZ
300 PM MST THU SEP 25 2014
.SYNOPSIS...
STRONG HIGH PRESSURE...COMBINED WITH A RELATIVELY DRY AIRMASS KEEP
MOST OF THE DESERT SOUTHWEST UNDER MOSTLY CLEAR SKIES WITH ABOVE
NORMAL TEMPERATURES THROUGH THE DAYLIGHT HOURS ON FRIDAY...WITH JUST
A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS OVER THE HIGHER
TERRAIN EAST OF PHOENIX DURING THE AFTERNOON AND EARLY EVENING
HOURS. A STRONG PACIFIC STORM IS THEN FORECAST TO MOVE INTO THE
WESTERN STATES LATE FRIDAY AND INTO THE WEEKEND...AND WILL PROVIDE A
GOOD CHANCE OF SHOWERS AND THUNDERSTORMS...WITH THE STRONGER STORMS
POSSIBLY PRODUCING LOCALLY GUSTY WINDS...HEAVY RAIN...AND HAIL.
AFTER A COLD FRONTAL PASSAGE... DRIER WEATHER WITH BELOW NORMAL
TEMPERATURES IS THEN FORECAST FROM LATE SUNDAY NIGHT THROUGH AT
LEAST THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...
NOTE...FORECAST CONFIDENCE IS CONTINUING TO INCREASE WITH REGARDS TO
A GOOD CHANCE OF SHOWERS/THUNDERSTORMS OVER SOUTH CENTRAL
AZ...INCLUDING PHOENIX ON SATURDAY MORNING AND AFTERNOON...WITH
POSSIBLE LOCALLY HEAVY RAIN...STRONG WINDS...AND HAIL.
TONIGHT THROUGH FRIDAY...
THE APPROACH OF STRONG PACIFIC SYSTEM...WHICH IS EXPECTED TO MOVE
INLAND OVER CENTRAL CA ON FRIDAY...HAS ALREADY BEGAN TO TURN THE
WINDS THROUGH THE LOWER PORTION OF THE ATMOSPHERE TO A MORE
SOUTHERLY DIRECTION THIS AFTERNOON. THIS HAS RESULTED IN A SURGE
UPWARDS IN SFC DEWPOINTS ACROSS THE LOWER DESERTS...WITH MANY
LOCATIONS ACROSS THE LOWER COLORADO RIVER VALLEY AND SE CA NOW
SEEING 70+F DEWPOINTS. THE LATEST GFS FORECAST SOUNDINGS ARE SHOWING
A GRADUAL INCREASE IN MID-LEVEL MOISTURE THROUGH TONIGHT AND INTO
THE DAYLIGHT HOURS ON FRIDAY...WHICH WILL LIKELY ALLOW MID-LEVEL
CLOUDINESS TO INCREASE THROUGH THE PERIOD...WITH THE HRRR AND GFS
ALSO SHOWING THE DEVELOPMENT OF ISOLATED SHOWERS/THUNDERSTORMS OVER
THE HIGHER TERRAIN EAST OF PHOENIX LATER THIS AFTERNOON...AND AGAIN
ON FRIDAY AFTERNOON/EVENING. THE OTHER IMPACT FROM THE APPROACHING
TROF ON FRIDAY WILL BE AN INCREASE OF THE WINDS ACROSS SE CA...WITH
SUSTAINED SOUTHERLY TO SOUTHWESTERLY WINDS AROUND 15KTS...WITH GUSTS
TO 25 KNOTS LIKELY.
FRIDAY NIGHT THROUGH SUNDAY...
LATEST MODEL SUITES CONTINUE TO ADVERTISE A MAJOR EARLY FALL
STORM...WHICH WILL BE MOVING INTO THE DESERT SOUTHWEST BEGINNING
LATE FRIDAY NIGHT...AND CONTINUING INTO SUNDAY. THIS MORNING/S 12Z
MODEL SUITES ARE VERY SIMILAR TO LAST NIGHT/S 00Z...WHICH BEGIN TO
INCREASE POPS ACROSS THE REGION LATE FRIDAY/EARLY SAT MORNING AS
UPPER-LEVEL DIFLUENCE INCREASES AND WINDS ALOFT INCREASE...WITH BULK
SHEAR VALUES RISING INTO THE 30-50KT RANGE ACROSS THE REGION BY
EARLY SATURDAY. THESE DYNAMICS...COMBINED WITH PWATS IN THE 1.50-175
INCH RANGE ARE EXPECTED TO PRODUCE SCATTERED-NUMEROUS
SHOWERS/TSTMS ACROSS THE REGION...WITH A FEW OF THESE CELLS
APPROACHING/REACHING SEVERE LIMITS. SHOWER/TSTM COVERAGE IS THEN
EXPECTED TO CONTINUE TO INCREASE THROUGH THE DAY ON SATURDAY AS THE
UPPER LOW MOVES INTO SOUTHERN NV. ALTHOUGH MOISTURE AND WIND SHEAR
PARAMETERS ARE LOOKING FAVORABLE FOR THE DEVELOPMENT OF SEVERE
STORMS...ONLY MINIMAL COOLING IS EXPECTED IN THE MID LEVELS...WITH
500MB TEMP FORECAST TO FALL ONLY ABOUT 3 DEGREES C...FROM AROUND -6C
TO -9C....WHICH WILL LIKELY PUT A CAP ON THE AMOUNT OF SEVERE STORM
ACTIVITY THAT WE WILL SEE. THE FLAGSTAFF CWA...ON THE OTHER
HAND...IS EXPECTED TO SEE MUCH BETTER COOLING ALOFT...WITH 500MB
TEMPS FALLING INTO THE -10-15C RANGE...GIVING THAT REGION A MUCH
BETTER CHANCE FOR WIDESPREAD SEVERE STORM ACTIVITY.
AS FAR AS RAINFALL AMOUNT ARE CONCERNED...THE MODELS SEEMS TO BE
CONVERGING TOWARDS AMOUNTS IN THE 0.50-1.00 INCH RANGE OVER THE
LOWER ELEVATIONS OF SOUTH-CENTRAL ARIZONA...WITH HIGHER AMOUNTS TO
THE NORTH AND EAST. AFTER SOME LINGERING SHOWER ACTIVITY ACROSS
SOUTH-CENTRAL AZ EARLY SUNDAY MORNING...A FAIRLY RAPID CLEARING
TREND FROM WEST TO EAST IS THEN EXPECTED TO OCCUR DURING THE DAY ON
SUNDAY AS THE SFC FRONT MOVES THROUGH AND DRIER AIR MOVES IN FROM
THE WEST. HOWEVER...ISOLATED TO SCATTERED SHOWER ACTIVITY COULD
LINGER INTO SUNDAY NIGHT OVER THE HIGHER TERRAIN OF SOUTHERN GILA
COUNTY DUE TO FAVORABLE UPSLOPE FLOW AND A WEAK SHORTWAVE ROTATING
AROUND THE MAIN UPPER LOW CENTER ACROSS THE REGION.
.MONDAY THROUGH THURSDAY...
DRY WEATHER WITH NEAR...OR SLIGHTLY BELOW NORMAL TEMPERATURES ARE
EXPECTED ACROSS THE ENTIRE FORECAST AREA AS WESTERLY FLOW ALOFT
CONTINUES TO IMPORT DRY AIR INTO THE REGION.
&&
AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
AFTERNOON AND EARLY EVENING FROM THE EASTERN PORTION OF THE PHOENIX
METRO AREA EASTWARD THROUGH THE HIGHER TERRAIN AREAS. LOW CONFIDENCE
IN ANY STORMS DIRECTLY AFFECTING THE PHOENIX TERMINALS...BUT CAN/T
RULE OUT STORM OUTFLOWS POTENTIALLY CAUSING WIND SHIFTS THIS
EVENING. WINDS OVERALL WILL MAINTAIN DIURNAL DIRECTIONS DURING THE
PERIOD AND REMAIN BELOW 10 KNOTS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
SHOWERS AND THUNDERSTORMS...MAINLY EAST OF PHOENIX...ARE POSSIBLE ON
SUNDAY AS AN UPPER LEVEL TROUGH LINGERS OVER THE REGION. DRIER AIR
WILL BEGIN MOVING INTO THE AREA ON MONDAY...WITH LITTLE TO NO CHANCE
OF CONVECTION THE REMAINING PORTION OF THE FORECAST PERIOD.
AFTERNOON MINIMUM HUMIDITY LEVELS WILL AVERAGE AROUND 20 PERCENT ON
SUNDAY...AND THEN TREND TO AROUND 15 PERCENT BY THURSDAY. IN
ADDITION TO THE DRIER AIR...COOLER TEMPERATURES ARE EXPECTED THE
ENTIRE PERIOD. SOME GUSTY WEST TO SOUTHWEST WINDS ARE POSSIBLE ALONG
AND BEHIND THE TROUGH ON SUNDAY...THOUGH WIND SPEEDS WILL BE
GENERALLY LIGHT AND FOLLOW TYPICAL DIURNAL PATTERNS MONDAY THROUGH
THURSDAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/VASQUEZ
AVIATION...MCLANE/KUHLMAN
FIRE WEATHER...MCLANE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
203 PM MST THU SEP 25 2014
.UPDATE...AVIATION AND FIRE WEATHER DISCUSSIONS UPDATED.
&&
.SYNOPSIS...
STRONG HIGH PRESSURE...COMBINED WITH A RELATIVELY DRY AIRMASS KEEP
MOST OF THE DESERT SOUTHWEST UNDER MOSTLY CLEAR SKIES WITH ABOVE
NORMAL TEMPERATURES THROUGH THE DAYLIGHT HOURS ON FRIDAY...WITH JUST
A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS OVER THE HIGHER
TERRAIN EAST OF PHOENIX DURING THE AFTERNOON AND EARLY EVENING
HOURS. A STRONG PACIFIC STORM IS THEN FORECAST TO MOVE INTO THE
WESTERN STATES LATE FRIDAY AND THE WEEKEND...AND WILL PROVIDE A GOOD
CHANCE OF SHOWERS AND THUNDERSTORMS...WITH THE STRONGER STORMS
POSSIBLY PRODUCING LOCALLY GUSTY WINDS AND HEAVY RAIN. AFTER A COLD
FRONTAL PASSAGE... DRIER WEATHER WITH BELOW NORMAL TEMPERATURES IS
THE FORECAST FROM LATE SUNDAY THROUGH THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...
NOTE...FORECAST CONFIDENCE IS CONTINUING TO INCREASE WITH REGARDS TO
A GOOD CHANCE OF SHOWERS/THUNDERSTORMS OVER SOUTH CENTRAL
AZ...INCLUDING PHOENIX ON SATURDAY MORNING AND AFTERNOON...WITH
POSSIBLE LOCALLY HEAVY RAIN.
TONIGHT THROUGH FRIDAY...
THE APPROACH OF STRONG PACIFIC SYSTEM...WHICH IS EXPECTED TO MOVE
INLAND OVER CENTRAL CA ON FRIDAY...HAS ALREADY BEGAN TO TURN THE
WINDS THROUGH THE LOWER PORTION OF THE ATMOSPHERE TO A MORE
SOUTHERLY DIRECTION THIS AFTERNOON. THIS HAS RESULTED IN AN INCREASE
IN SFC DEWPOINTS ACROSS THE LOWER DESERTS...WITH MANY LOCATIONS IN
THE LOWER COLORADO RIVER VALLEY AND SE CA SEEING 70+F DEWPOINTS. THE
LATEST GFS FORECAST SOUNDINGS ARE SHOWING A GRADUAL INCREASE IN
MID-LEVEL MOISTURE THROUGH TONIGHT AND THE DAYLIGHT HOURS ON
FRIDAY...WHICH WILL LIKELY ALLOW MID-LEVEL CLOUDINESS TO INCREASE
THROUGH THE PERIOD...WITH THE HRRR AND GFS SHOWING THE DEVELOPMENT
OF ISOLATED SHOWERS/THUNDERSTORMS OVER THE HIGHER TERRAIN EAST OF
PHOENIX THIS AFTERNOON...AND AGAIN ON FRIDAY AFTERNOON/EVENING. THE
OTHER IMPACT FROM THE APPROACHING TROF ON FRIDAY WILL BE AN INCREASE
OF THE WINDS ACROSS SE CA...WITH SUSTAINED SOUTHERLY TO
SOUTHWESTERLY WINDS AROUND 15KTS...WITH GUSTS TO 25 KNOTS LIKELY.
FRIDAY NIGHT THROUGH SUNDAY...
LATEST MODEL SUITES CONTINUE TO ADVERTISE A MAJOR EARLY FALL STORM
WILL BE MOVING INTO THE DESERT SOUTHWEST BEGINNING LATE FRIDAY
NIGHT...AND CONTINUING INTO SUNDAY. THIS MORNING/S 12Z MODEL SUITES
ARE VERY SIMILAR TO LAST NIGHT/S 00Z...WHICH BEGIN TO INCREASE POPS
ACROSS THE REGION LATE FRIDAY/EARLY SAT MORNING AS UPPER-LEVEL
DIFLUENCE INCREASES AND WINDS ALOFT INCREASE...WITH BULK SHEAR
VALUES RISING INTO THE 30-50KT RANGE ACROSS THE REGION. THESE
DYNAMICS...COMBINED WITH PWATS IN THE 1.50-175 INCH RANGE ARE
EXPECTED TO PRODUCE SCATTERED-NUMEROUS SHOWERS/TSTORMS ACROSS THE
REGION...WITH A FEW OF THESE CELLS APPROACHING SEVERE LIMITS.
SHOWER/TSTORM COVERAGE IS THEN EXPECTED TO GRADUALLY INCREASE
THROUGH THE DAY ON SATURDAY
AS MENTIONED ABOVE...A LARGE COOL EARLY FALL SEASON STORM WILL
CONTINUE TO EVOLVE SOUTH ALONG THE WEST COAST TODAY AND FRIDAY. THE
EUROPEAN MODEL HAS NOW COME AROUND TO THE MORE PROGRESSIVE GFS
SOLUTION...WITH NEARLY IDENTICAL MASS FIELD FORECASTS. THEREFORE
CONFIDENCE IS INCREASING FOR A GOOD CHANCE OF PRECIP OVER AZ ON
SATURDAY.
STRONG 500/300 HEIGHT FALLS ARE FORECAST TO DEVELOP OVER PARTS OF
SOUTHERN CA FRIDAY EVENING...AND OVER SOUTHERN NEVADA SATURDAY
MORNING. THIS PORTENDS INCREASED LOW LEVEL SOUTHERLY WINDS AND
STRONG MOISTURE ADVECTION FRIDAY NIGHT INTO SATURDAY. INCREASINGLY
CYCLONIC SOUTHWESTERLY JETSTREAM WINDS OVER CENTRAL AND WESTERN AZ
BY 18Z SATURDAY...COMBINED WARM MOIST ADVECTION PORTEND A GOOD
CHANCE OF SHOWERS AND THUNDERSTORMS WITH POSSIBLY HEAVY RAIN IN
SOUTHWEST AND SOUTH-CENTRAL AZ...INCLUDING PHOENIX. ADDITIONALLY...
THE GFS IS STILL FORECASTING ENOUGH VERTICAL WIND SHEAR FOR THE
POSSIBILITY OF ORGANIZED THUNDERSTORMS NEAR PHOENIX WITH STRONG
WINDS AND HAIL. THEREFORE PRECIP PROBABILITIES FOR SATURDAY WERE
ADJUSTED HIGHER.
SHOWER POTENTIAL WILL MOVE INTO EASTERN AZ SATURDAY EVENING WITH THE
THE COLD FRONT...I.E. OVER SOUTHERN GILA COUNTY ZONE 24...WITH
CLEARING OVER SOUTHWEST AND SOUTH CENTRAL AZ.
SUNDAY...
A MUCH DRIER AIRMASS FOLLOWING THE COLD FRONT WILL SPREAD ACROSS
SOUTHEAST CA...SOUTHWEST AND SOUTH CENTRAL AZ SUNDAY. HOWEVER...
DEEP MOISTURE WILL CONTINUE TO REMAIN ALONG THE EASTERN AZ BORDER
UNTIL SUNDAY NIGHT. A THREAT OF SHOWERS AND THUNDERSTORMS WILL
LINGER OVER THE MOUNTAINS OF SOUTHERN GILA COUNTY ON SUNDAY.
MONDAY THROUGH WEDNESDAY...
DRY WEATHER WITH NEAR SEASONAL TEMPERATURES ARE EXPECTED ACROSS THE
ENTIRE FORECAST AREA.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
AFTERNOON AND EARLY EVENING FROM THE EASTERN PORTION OF THE PHOENIX
METRO AREA EASTWARD THROUGH THE HIGHER TERRAIN AREAS. LOW CONFIDENCE
IN ANY STORMS DIRECTLY AFFECTING THE PHOENIX TERMINALS...BUT CAN/T
RULE OUT STORM OUTFLOWS POTENTIALLY CAUSING WIND SHIFTS THIS
EVENING. WINDS OVERALL WILL MAINTAIN DIURNAL DIRECTIONS DURING THE
PERIOD AND REMAIN BELOW 10 KNOTS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
SHOWERS AND THUNDERSTORMS...MAINLY EAST OF PHOENIX...ARE POSSIBLE ON
SUNDAY AS AN UPPER LEVEL TROUGH LINGERS OVER THE REGION. DRIER AIR
WILL BEGIN MOVING INTO THE AREA ON MONDAY...WITH LITTLE TO NO CHANCE
OF CONVECTION THE REMAINING PORTION OF THE FORECAST PERIOD.
AFTERNOON MINIMUM HUMIDITY LEVELS WILL AVERAGE AROUND 20 PERCENT ON
SUNDAY...AND THEN TREND TO AROUND 15 PERCENT BY THURSDAY. IN
ADDITION TO THE DRIER AIR...COOLER TEMPERATURES ARE EXPECTED THE
ENTIRE PERIOD. SOME GUSTY WEST TO SOUTHWEST WINDS ARE POSSIBLE ALONG
AND BEHIND THE TROUGH ON SUNDAY...THOUGH WIND SPEEDS WILL BE
GENERALLY LIGHT AND FOLLOW TYPICAL DIURNAL PATTERNS MONDAY THROUGH
THURSDAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/VASQUEZ
AVIATION...MCLANE/KUHLMAN
FIRE WEATHER...MCLANE
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
830 AM PDT THU SEP 25 2014
.SYNOPSIS...AN EARLY SEASON PACIFIC WEATHER SYSTEM WILL SPREAD RAIN
ACROSS THE BAY AREA THIS MORNING...REACHING AS FAR SOUTH AS
MONTEREY COUNTY. RAINFALL WILL MOSTLY END BY LATE IN THE MORNING...
BUT ISOLATED SHOWERS ARE POSSIBLE FROM MIDDAY TODAY THROUGH AT
LEAST FRIDAY EVENING. THERE IS ALSO A SLIGHT CHANCE OF
THUNDERSTORMS OVER THE COASTAL WATERS AND ADJOINING COASTAL LAND
AREAS NORTH OF POINT REYES TODAY. THIS WEATHER SYSTEM WILL ALSO
RESULT IN COOLER THAN NORMAL DAYTIME TEMPERATURES THROUGH THE
WEEKEND. DRY WEATHER WILL RETURN OVER THE WEEKEND...BUT
TEMPERATURES WILL REMAIN BELOW NORMAL INTO EARLY NEXT WEEK.
&&
.DISCUSSION...AS OF 8:30 AM THURSDAY...MAIN FRONTAL BAND NICELY
PICKED UP BY KMUX RADAR THIS MORNING. HEAVIEST RAINFALL CURRENTLY
STRETCHING TO THE NNE FROM MONTEREY BAY UP TO THE FAR EAST BAY.
TOTALS HAVE BEEN GOOD FOR THIS TIME OF YEAR WITH SAN FRANCISCO UP
TO 1/2" WHILE MANY SPOTS IN THE NORTH AND EAST BAY HAVE PICKED UP
BETWEEN 2 AND 4 TENTHS. WILL BE ISSUING UPDATED RAINFALL NUMBERS
LATER THIS MORNING. ENOUGH MOISTURE AND INSTABILITY WILL BE
AROUND, SO SCATTERED SHOWERS CAN BE EXPECTED THROUGH THE DAY,
ALTHOUGH POST-FRONTAL RAINFALL AMOUNTS SHOULD GENERALLY BE LIGHT.
ALSO WORTH NOTING THAT LIGHTNING HAS BEEN DETECTED WELL TO OUR
WEST (300 PLUS MILES). HOWEVER, THAT AREA OF CONVECTION IS HEADING
TOWARD OUR AREA SO WILL KEEP A CLOSE EYE ON IT. CURRENTLY FORECAST
MENTIONS A CHANCE FOR THUNDERSTORMS ALONG THE NORTHERN WATERS AND
TO THE NORTH COAST.
WILL BE DOING UPDATES TO THE FORECAST THIS MORNING AS NECESSARY.
.PREVIOUS DISCUSSION...LATEST RADAR IMAGERY SHOWS RAINFALL ECHOES
ASSOCIATED WITH AN APPROACHING FRONTAL BAND NOW EXTENDING FROM
OVER SONOMA AND MARIN COUNTIES SOUTHWARD OVER THE COASTAL WATERS.
THE RAINFALL IS EXPECTED TO SPREAD INTO THE SAN FRANCISCO BAY AREA
WITHIN THE NEXT COUPLE OF HOURS AND THE HEAVIEST RAIN IS EXPECTED
TO OCCUR DURING THE MORNING COMMUTE HOURS. RAINFALL IS EXPECTED TO
REACH AS FAR SOUTH AS THE BIG SUR COAST LATER THIS MORNING AS THE
FRONTAL BAND MOVES THROUGH. RAINFALL AMOUNTS THROUGH THIS MORNING
ARE EXPECTED TO RANGE FROM A TENTH TO A HALF INCH ACROSS THE BAY
AREA...EXCEPT AS MUCH AS THREE-QUARTERS OF AN INCH IN THE NORTH
BAY MOUNTAINS. FROM MONTEREY BAY SOUTHWARD RAINFALL AMOUNTS WILL
MOSTLY BE A TENTH OF AN INCH OR LESS EXCEPT LOCALLY A QUARTER INCH
IN THE HILLS ABOVE BIG SUR.
RAIN IS EXPECTED TO TAPER OFF THIS MORNING AS THE FRONTAL BAND
MOVES THROUGH. HOWEVER ISOLATED SHOWERS WILL REMAIN POSSIBLE
THROUGH FRIDAY AS AN UPPER TROUGH REMAINS OVER THE AREA KEEPING AN
UNSTABLE AIRMASS IN PLACE. A SLIGHT CHANCE OF THUNDERSTORMS IS
ALSO INDICATED TODAY ACROSS THE NORTHERN COASTAL WATERS AND NORTH
BAY ZONES...AND AGAIN ON FRIDAY ACROSS PORTIONS OF THE NORTH BAY
IN RESPONSE TO THIS UNSTABLE AIRMASS.
SHOWER ACTIVITY IS EXPECTED TO END BY LATE FRIDAY EVENING. COOLER
THAN NORMAL CONDITIONS WILL PERSIST THROUGH THE WEEKEND...BUT
BUILDING HIGH PRESSURE OVER THE AREA BY NEXT WEEK WILL BRING A
GRADUAL WARMING TREND TO THE DISTRICT.
&&
.AVIATION...AS OF 04:11 AM PDT THURSDAY...COLD FRONT IS CLEARLY
DISCERNIBLE ON RADAR AND MAKING ITS WAY THROUGH THE BAY AREA EARLY
THIS MORNING. THE FROPA WILL BRING IFR/MVFR CIGS...-RA AND REDUCED
VSBY. THE TIMING FROM THE HRRR MODEL SEEMS PRETTY GOOD...MEANING
CONDITIONS WILL GRADUALLY IMPROVE 15-18Z FROM KSTS TO KSFO/KOAK.
SOUTHERN TERMINALS WILL HOLD ONTO CIGS AND RAIN CHANCES A LITTLE
LONGER. BEHIND THE FRONT...AFTERNOON SCT CIGS WITH A CONVECTIVE
SHOWER WILL BE POSSIBLE. RESIDUAL MOISTURE WILL ALSO ALLOW FOR
SOME CIGS TONIGHT. CONF IS MEDIUM.
VICINITY OF KSFO...IFR/MVFR CONDITIONS THIS MORNING WITH WET
RUNWAYS. PRECIP/CIGS LIFTING 16-17Z. MAINLY VFR THIS AFTERNOON.
PATCHY CIGS TONIGHT.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR CIGS AHEAD OF FRONT THIS
MORNING. THE TAIL END OF THE FRONT WILL BRING SOME SCT SHOWERS
LATER THIS MORNING INTO EARLY THIS AFTERNOON. VFR THIS AFTERNOON.
&&
.MARINE...AS OF 04:11 AM PDT THURSDAY...A COLD FRONT WILL MOVE
THROUGH THE COASTAL WATERS TODAY BRINGING A CHANCE FOR RAIN AND
POSSIBLY AFTERNOON THUNDERSTORMS. AS THE COLD FRONT EXITS THE
REGION NORTHWEST FLOW WILL INCREASE ALONG THE CENTRAL COAST ON
FRIDAY. THE INCREASING WINDS WILL PRODUCE BUILDING WIND WAVES AND
LOCALLY HAZARDOUS CONDITIONS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...ROUGH BAR ADVISORY FOR SF BAR UNTIL 3 PM
&&
$$
PUBLIC FORECAST: BELL/SIMS
AVIATION/MARINE: MM
VISIT US AT WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
420 AM PDT THU SEP 25 2014
.SYNOPSIS...AN EARLY SEASON PACIFIC WEATHER SYSTEM WILL SPREAD RAIN
ACROSS THE BAY AREA THIS MORNING...REACHING AS FAR SOUTH AS
MONTEREY COUNTY. RAINFALL WILL MOSTLY END BY LATE IN THE MORNING...
BUT ISOLATED SHOWERS ARE POSSIBLE FROM MIDDAY TODAY THROUGH AT
LEAST FRIDAY EVENING. THERE IS ALSO A SLIGHT CHANCE OF
THUNDERSTORMS OVER THE COASTAL WATERS AND ADJOINING COASTAL LAND
AREAS NORTH OF POINT REYES TODAY. THIS WEATHER SYSTEM WILL ALSO
RESULT IN COOLER THAN NORMAL DAYTIME TEMPERATURES THROUGH THE
WEEKEND. DRY WEATHER WILL RETURN OVER THE WEEKEND...BUT
TEMPERATURES WILL REMAIN BELOW NORMAL INTO EARLY NEXT WEEK.
&&
.DISCUSSION...AS OF 2:56 AM THURSDAY...LATEST RADAR IMAGERY SHOWS
RAINFALL ECHOES ASSOCIATED WITH AN APPROACHING FRONTAL BAND NOW
EXTENDING FROM OVER SONOMA AND MARIN COUNTIES SOUTHWARD OVER THE
COASTAL WATERS. THE RAINFALL IS EXPECTED TO SPREAD INTO THE SAN
FRANCISCO BAY AREA WITHIN THE NEXT COUPLE OF HOURS AND THE HEAVIEST
RAIN IS EXPECTED TO OCCUR DURING THE MORNING COMMUTE HOURS.
RAINFALL IS EXPECTED TO REACH AS FAR SOUTH AS THE BIG SUR COAST
LATER THIS MORNING AS THE FRONTAL BAND MOVES THROUGH. RAINFALL
AMOUNTS THROUGH THIS MORNING ARE EXPECTED TO RANGE FROM A TENTH TO A
HALF INCH ACROSS THE BAY AREA...EXCEPT AS MUCH AS THREE-QUARTERS
OF AN INCH IN THE NORTH BAY MOUNTAINS. FROM MONTEREY BAY SOUTHWARD
RAINFALL AMOUNTS WILL MOSTLY BE A TENTH OF AN INCH OR LESS EXCEPT
LOCALLY A QUARTER INCH IN THE HILLS ABOVE BIG SUR.
RAIN IS EXPECTED TO TAPER OFF THIS MORNING AS THE FRONTAL BAND
MOVES THROUGH. HOWEVER ISOLATED SHOWERS WILL REMAIN POSSIBLE
THROUGH FRIDAY AS AN UPPER TROUGH REMAINS OVER THE AREA KEEPING AN
UNSTABLE AIRMASS IN PLACE. A SLIGHT CHANCE OF THUNDERSTORMS IS
ALSO INDICATED TODAY ACROSS THE NORTHERN COASTAL WATERS AND NORTH
BAY ZONES...AND AGAIN ON FRIDAY ACROSS PORTIONS OF THE NORTH BAY
IN RESPONSE TO THIS UNSTABLE AIRMASS.
SHOWER ACTIVITY IS EXPECTED TO END BY LATE FRIDAY EVENING. COOLER
THAN NORMAL CONDITIONS WILL PERSIST THROUGH THE WEEKEND...BUT
BUILDING HIGH PRESSURE OVER THE AREA BY NEXT WEEK WILL BRING A
GRADUAL WARMING TREND TO THE DISTRICT.
&&
.AVIATION...AS OF 04:11 AM PDT THURSDAY...COLD FRONT IS CLEARLY
DISCERNABLE ON RADAR AND MAKING ITS WAY THROUGH THE BAY AREA EARLY
THIS MORNING. THE FROPA WILL BRING IFR/MVFR CIGS...-RA AND REDUCED
VSBY. THE TIMING FROM THE HRRR MODEL SEEMS PRETTY GOOD...MEANING
CONDITIONS WILL GRADUALLY IMPROVE 15-18Z FROM KSTS TO KSFO/KOAK.
SOUTHERN TERMINALS WILL HOLD ONTO CIGS AND RAIN CHANCES A LITTLE
LONGER. BEHIND THE FRONT...AFTERNOON SCT CIGS WITH A CONVECTIVE
SHOWER WILL BE POSSIBLE. RESIDUAL MOISTURE WILL ALSO ALLOW FOR
SOME CIGS TONIGHT. CONF IS MEDIUM.
VICINITY OF KSFO...IFR/MVFR CONDITIONS THIS MORNING WITH WET
RUNWAYS. PRECIP/CIGS LIFTING 16-17Z. MAINLY VFR THIS AFTERNOON.
PATCHY CIGS TONIGHT.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR CIGS AHEAD OF FRONT THIS
MORNING. THE TAIL END OF THE FRONT WILL BRING SOME SCT SHOWERS
LATER THIS MORNING INTO EARLY THIS AFTERNOON. VFR THIS AFTERNOON.
&&
.MARINE...AS OF 04:11 AM PDT THURSDAY...A COLD FRONT WILL MOVE
THROUGH THE COASTAL WATERS TODAY BRINGING A CHANCE FOR RAIN AND
POSSIBLY AFTERNOON THUNDERSTORMS. AS THE COLD FRONT EXITS THE
REGION NORTHWEST FLOW WILL INCREASE ALONG THE CENTRAL COAST ON
FRIDAY. THE INCREASING WINDS WILL PRODUCE BUILDING WIND WAVES AND
LOCALLY HAZARDOUS CONDITIONS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...ROUGH BAR ADVISORY FOR SF BAR UNTIL 3 PM
&&
$$
PUBLIC FORECAST: SIMS
AVIATION/MARINE: MM
VISIT US AT WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS TAUNTON MA
723 PM EDT FRI SEP 26 2014
.SYNOPSIS...
HIGH PRESSURE BUILDS OVER SOUTHERN NEW ENGLAND THROUGH THE
WEEKEND...BRINGING WARM AND DRY CONDITIONS. A COLD FRONT SWEEPS
THE REGION WITH POSSIBLE SHOWERS FOR THE EARLY WEEK. A COASTAL
STORM IS POSSIBLE MIDWEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
7 PM UPDATE...
NOTING THE LOW- TO MID-50 DEWPOINTS ALONG WITH THE ANTICIPATION OF
LIGHT AND VARIABLE WINDS OVERNIGHT ALLOWING FOR DECENT OVERNIGHT
RADIATIONAL COOLING WITH LOWS FALLING INTO THE MID- TO UPPER-40S.
THIS RAISES THE CONCERN OVER FOG ACROSS THE REGION...POTENTIALLY
DENSE IN SPOTS /ESPECIALLY IN SHELTERED VALLEY REGIONS/ WITH
VISIBILITIES OF A QUARTER-MILE OR LESS. HIGHEST CONFIDENCE IN THE
CT-RIVER VALLEY FROM SPRINGFIELD NORTHWARD...AND FOR THOSE AREAS
THROUGHOUT THE MERRIMACK-RIVER VALLEY WHICH SAW FOG LAST NIGHT.
A LOT OF THE MODEL GUIDANCE SUGGESTS FOG WILL NOT BE SO WIDESPREAD
INCLUDING THE HRRR /THOUGH IT DID NOT CAPTURE THE FOG AT ALL LAST
NIGHT/. BUT TEMPERATURES PRESENTLY ARE DROPPING FAST WHILE
DEWPOINTS REMAIN UNCHANGED. LENDS FOR A LOT OF NAIL-BITING. IT
APPEARS FOG IS GOING TO DEVELOP AS THERE IS NOT MUCH INDICATION OF
DRIER AIR WORKING INTO THE REGION. HAVE CONTENDED WITH THE
FORECAST AS BEST AS POSSIBLE TO HIGHLIGHT THOSE AREAS WHERE FOG
DEVELOPMENT IS OF HIGHEST CONFIDENCE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
HIGH PRESSURE SURFACE AND ALOFT WITH HIGHER THAN NORMAL HEIGHTS
FOR THE UPPER RIDGE. THIS POINTS TO WARMER THAN NORMAL
TEMPERATURES.
THIS MEANS CLEAR SKIES AND LIGHT WIND. TEMPS AT THE TOP OF THE
DAYTIME MIXED LAYER...AROUND 875-900 MB...WILL BE AROUND 17C.
THIS WILL SUPPORT MAX SFC TEMPS 80-83F...A FEW DEGREES COOLER IN
THE HILLS AND ALONG THE COAST. THE LIGHT PRESSURE GRADIENT WILL
ALLOW FOR A SEA BREEZE LATE MORNING THROUGH THE EVENING.
CLEAR SKIES AND LIGHT WIND SATURDAY NIGHT WILL MEAN TEMPS AGAIN
COOLING TO NEAR DEW POINT...AS WELL AS FOG LATE AT NIGHT IN THE
USUAL LOCATIONS.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
*/ HIGHLIGHTS...
- DRY AND UNSEASONABLY WARM FOR SUNDAY
- A SLIGHT CHANCE OF SHOWERS MONDAY INTO TUESDAY WITH A COLD FRONT
- ANOTHER COASTAL LOW SETUP POSSIBLE BY MIDWEEK
- UNCERTAIN LATE-WEEK FORECAST
*/ OVERVIEW AND MODEL PREFERENCE...
ATMOSPHERIC TELECONNECTIONS SIGNAL A SHIFT TOWARDS A LESS-ZONAL MORE
AMPLIFIED PATTERN AS FLOW BUCKLES CONSEQUENTIAL OF COLDER AIR OVER
GREENLAND BROUGHT S BY A BLOCKING ANOMALOUS LOW PRESSURE TOWARDS THE
S-TIP. THIS RESULTS IN SUPPORT OF UPSTREAM RIDGING AND A WARMER-THAN-
NORMAL PATTERN ACROSS THE E CONUS. NOTABLY...ENSEMBLE SOLUTIONS ALL
SUPPORT H5 POSITIVE-HEIGHT ANOMALIES AND CONSIDERABLY WARMER H85
TEMPERATURES SURGING N INTO THE S HUDSON BAY REGION AND E CANADA AT
TIMES. WOULD BELIEVE THE OVERALL THEME INTO EARLY OCTOBER TO BE DRY
WITH WARM TEMPERATURES...BUT CUT-OFF DISTURBANCES REARWARD OF THE S-
GREENLAND LOW ACROSS THE NE-CONUS LEND TO UNCERTAINTY WITHIN THE
OVERALL FORECAST.
VERY WARM FOR LATE SEPTEMBER ON SUNDAY UNDER HIGH PRESSURE...BUT THE
ATTENDANT RIDGE DEAMPLIFIES AS A W-CONUS DISTURBANCE EVOLVES INTO A
CLOSED LOW. ALLOWING A CUT-OFF IMPULSE TO DIVE SE...AN OPEN-WAVE
TROUGH INTRUSION PUSHES A COLD FRONT GRADUALLY ACROSS THE REGION
MONDAY INTO TUESDAY. SOME SYNOPTIC FORCING IS EVIDENT WHICH WILL
LIKELY GENERATE SHOWERS. GREATER CONCERN IS THE EVOLUTION OF THE CUT-
OFF IMPULSE WITH TROPICAL-ORIGIN ENERGY FROM THE GULF MEETING ALONG
THE COLD FRONT NOW PUSHED SE AND OFFSHORE OF NEW ENGLAND BY MIDWEEK.
LOTS OF ENSEMBLE MEMBER SPREAD AS TO A LIKELY AREA OF LOW PRESSURE
DEVELOPING ALONG THE STALLED FRONTAL BOUNDARY OFF THE MID-ATLANTIC
SE OFFSHORE OF NEW ENGLAND /LIKELY BECAUSE ENSEMBLE MEANS SIGNAL A
RRQ OF THE UPPER-LEVEL-JET COLLOCATED WITH THE FRONT/. POSITION OF
THE LOW RELATIVE TO THE S-COASTLINE AND ITS STRENGTH ARE IN QUESTION
LENDING TO UNCERTAINTY IN THE FORECAST...AS WELL AS NEIGHBORING HIGH
PRESSURE TO THE N. A SIMILAR SETUP POSSIBLE AS THIS PAST THURSDAY
WITH THE POTENTIAL FOR A TIGHT-GRADIENT OF PRECIPITATION SETTING UP
OVER OR S OF THE S-TIER OF NEW ENGLAND. ONLY CERTAINTY IS THAT WITH
HIGH PRESSURE SITUATED N AND THE STALLED FRONTAL BOUNDARY S THAT A
TIGHTENING PRESSURE-GRADIENT WILL LEND TO BLUSTERY E/NE WINDS DURING
THE MIDWEEK TIMEFRAME. SHOULD A STRONG LOW DEVELOP AS EXPECTED WOULD
ONLY EXACERBATE THE WINDS.
HAVE HIGHER CONFIDENCE OF A MIDWEEK COASTAL STORM SETUP. INCREASED
POPS ACCORDINGLY FOR AREAS OF S/SE NEW ENGLAND. SHOULD TURN BLUSTERY
WITH WINDS OUT OF E/NE. CONDITIONS IMPROVING TOWARDS THE END OF THE
WEEK BUT WILL HAVE TO WATCH THE EVOLUTION OF THE W-CONUS DISTURBANCE
TO THE E AND AS TO WHETHER THE BLOCK OVER S-GREENLAND HOLDS.
CONTINUED HIGH CONFIDENCE WITH ENSEMBLE MEANS OVER DETERMINISTIC
SOLUTIONS. EVIDENCE TO SUGGEST BASED ON RUN-TO-RUN MODEL COMPARISONS
THAT THE POTENTIAL MERGING OF CUT-OFF IMPULSES WITH TROPICAL ENERGY
TOWARDS MIDWEEK IS STILL NOT BEING WELL-HANDLED.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...HIGH CONFIDENCE.
23Z UPDATE...
ASIDE FROM SE-SHORES WITH NE-WIND GUSTS AROUND 10 KTS POSSIBLE...
WINDS OVERALL SHOULD BE LIGHT AND VRB OVERNIGHT. HIGH CONFIDENCE
OF AREAS OF IFR-VLIFR DENSE FOG THROUGH THE CT-RIVER VALLEY FROM
KORE NORTHWARD WITH 1/2SM VV002...THIS INCLUDES S NH. AS TO ELSE-
WHERE...TERMINALS WHICH SAW FOG LAST NIGHT ARE LIKELY TO REPEAT
AGAIN THIS EVENING.
SATURDAY...VFR. SEA BREEZES DEVELOP LATE MORNING THROUGH EVENING.
SATURDAY NIGHT...VFR. LIGHT WIND. AREAS OF IFR/LIFR IN LOCALLY
DENSE VALLEY FOG AFTER MIDNIGHT.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF. MODERATE CONFIDENCE IN
DEVELOPMENT OF FOG LATE TONIGHT.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY...HIGH CONFIDENCE. VFR. LIGHT WINDS. SEA-BREEZES ALONG THE
SHORES.
MONDAY...HIGH CONFIDENCE. VFR. COLD FRONT SWEEPING THROUGH THE
TERMINALS AND OFFSHORE. SLIGHT CHANCE -SHRA.
TUESDAY INTO WEDNESDAY...MODERATE CONFIDENCE. HIGH PRESSURE TO THE N
WITH A POTENTIAL COASTAL LOW TO THE S WILL RESULT IN BREEZY E/NE
WINDS. MIX OF LOW-END VFR TO IFR CONDITIONS POSSIBLE FOR THE S-COAST
TERMINALS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...HIGH CONFIDENCE.
7 PM UPDATE...
NE-WINDS CONTINUE TO TAPER...THE STRONGEST OF WHICH ARE ACROSS
THE SE WATERS WITH GUSTS UP TO 15 KTS. THIS HAS ALLOWED WIND-WAVE
ACTIVITY TO SUBSIDE. INNER-WATER BUOYS HAVE DROPPED BELOW 5-FEET
ALLOWING SMALL-CRAFT ADVISORIES TO CONCLUDE. WILL CONTINUE WITH
SMALL-CRAFT ADVISORIES ON THE S-OUTER WATERS AS BUOY 44097 AND
44017 ARE REPORTING SEAS AROUND 5-FEET. ADVISORIES WILL DROP OFF
BY SATURDAY MORNING AS WAVES COMPLETELY DIMINISH.
SATURDAY AND SATURDAY NIGHT...
HIGH PRESSURE BUILDS OVER THE WATERS. NORTH WINDS DIMINISH AND
BECOME LIGHT/VARIABLE. LOCAL SEA BREEZES LIKELY SATURDAY LATE
MORNING AND AFTERNOON NEAR SHORE.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY...HIGH CONFIDENCE. GOOD BOATING WEATHER UNDER SW WINDS AND
HIGH PRESSURE.
MONDAY...HIGH CONFIDENCE. COLD FRONT GRADUALLY SWEEPS THE WATERS
BEHIND WHICH THE CHANCE OF SHOWERS INCREASES ALONG WITH BLUSTERY NE-
WINDS. SEAS BEGINNING TO BUILD BUT INITIAL THINKING IS THAT THEY
WILL REMAIN BELOW 5-FEET.
TUESDAY INTO WEDNESDAY...MODERATE CONFIDENCE. OFFSHORE COASTAL STORM
LIKELY YET ITS PROXIMITY AND STRENGTH TO THE WATERS UNCERTAIN. E/NE
WINDS WITH GUSTS OF AROUND 25 KTS POSSIBLE. SEAS BUILDING 5-7 FEET
ON THE OUTER WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR ANZ254-255.
SMALL CRAFT ADVISORY UNTIL 3 AM EDT SATURDAY FOR ANZ256.
&&
$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...WTB/SIPPRELL
SHORT TERM...WTB
LONG TERM...SIPPRELL
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
305 PM EDT THU SEP 25 2014
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWING A COMPLEX AND SLOW
MOVING UPPER LEVEL PATTERN ACROSS THE CONUS. DEFINED NORTHERN STREAM
FLOW ARRIVES ALONG THE PACIFIC COAST AND RIDGES WELL UP INTO WESTERN
CANADA BEFORE FLATTENING OUT AND BECOME MORE ZONAL TO THE NORTH OF
THE GREAT LAKES AND NEW ENGLAND. A DISPLACED SHORTWAVE TROUGH
CONTINUES TO PIVOT NORTHWARD THROUGH THE OHIO VALLEY/NE STATES
AROUND THE WESTERN PERIPHERY OF A LARGE UPPER RIDGE ACROSS THE
WESTERN ATLANTIC. OUR FORECAST AREA ALSO RESIDES WITHIN THE WESTERN
CIRCULATION OF THIS UPPER RIDGE ALLOWING ABUNDANT MID/UPPER LEVEL
MOISTURE TO STREAM BACK NORTHWARD OVERHEAD.
AT THE SURFACE...AS MENTIONED ABOVE...LOOKING AT NE FLOW BETWEEN A
LARGE RIDGE OF HIGH PRESSURE OVER THE DEEP SOUTH...AND AN INVERTED
SURFACE TROUGH OFF THE FL EAST COAST. THIS GRADIENT WILL KEEP THE NE
FLOW GOING INTO TONIGHT.
25/12Z SOUNDING PROFILE CERTAINLY MOISTENED UP IN THE MIDDLE
LEVELS COMPARED TO WEDNESDAY MORNING...WITH PW VALUES BACK UP NEAR
2". THE STRATUS DECK WHICH WAS WELL SAMPLED BY THE MORNING SOUNDING
WAS QUITE STUBBORN...BUT HAS FINALLY ERODED INTO A MAINLY SCT-BKN
CUMULUS FIELD. NUMEROUS SHOWERS AND STORMS ARE NOW BREAKING OUT OVER
THE SOUTH-CENTRAL PENINSULA AND WILL BE EVOLVING WEST AND NORTHWEST
INTO THE LATER AFTERNOON AND EARLY EVENING HOURS. STILL FEEL
CONFIDENT IN LIKELY TO CATEGORICAL RAIN CHANCES TO THE SOUTH OF
TAMPA BAY...WHERE GOOD DIURNAL HEATING HAS OCCURRED TO THE SOUTH OF
A ILL-DEFINED SURFACE BOUNDARY. EXPECT LITTLE TO NO RAINFALL TO THE
NORTH OF TAMPA BAY GIVEN THE SIGNIFICANT REDUCTION IN DIURNAL
HEATING AS A RESULT OF THE LATE BURN OFF OF THE LOWER LEVEL STRATUS.
TEMPERATURES ARE STILL STUCK IN THE 70S IN PORTIONS OF THE NATURE
COAST. THE TRANSITION ZONE IS THE TAMPA BAY AREA / I-4 CORRIDOR.
THERE SHOULD BE A FEW STORMS ROLLING ACROSS THIS AREA LATE
TODAY...BUT STILL FEEL COVERAGE WILL NOT BE SUFFICIENT ENOUGH TO
CONSIDER RAIN CHANCES "LIKELY". LATEST HIRES HRRR SEEMS TO AGREE
THAT THE I-4 CORRIDOR WILL BE THE WET VS DRY BOUNDARY...AND IS VERY
AGGRESSIVE WITH RAIN COVERAGE OVER THE SOUTHERN HALF OF THE FORECAST
AREA INTO THE EVENING HOURS.
&&
.SHORT TERM (TONIGHT AND FRIDAY)...
TONIGHT...
IF THE LATEST HRRR IS CORRECT...THEN SHOWERS/AREAS OF RAIN WOULD
LINGER ALONG THE SUNCOAST ZONES THROUGH 2-4Z THIS EVENING. MAY MAKE
A FEW FINAL ADJUSTMENT TO EXTEND THE END OF RAIN CHANCE FOR THESE
ZONES IF NEXT LOCAL HIRES RUN AGREES WITH THE HRRR. OTHERWISE...
AFTER THE EVENING ACTIVITY DISSIPATES...A GENERALLY DRY AND QUIET
OVERNIGHT PERIOD IS EXPECTED. THE SETUP AGAIN LOOKS FAVORABLE FOR
THE DEVELOPMENT AND SOUTHWARD ADVECTION OF LOW LEVEL STRATUS INTO
THE NORTHERN FLORIDA PENINSULA. QUESTION WILL BE JUST HOW FAR IT
MIGRATES SOUTHWARD BEFORE SUNRISE. WOULD THINK WE WOULD NOT SEE ITS
PROGRESS BE AS EXTENSIVE AS WAS SEEN THIS MORNING...GIVEN THE
EVOLUTION OF A SURFACE TROUGH ACROSS THE SOUTHERN HALF OF THE
PENINSULA WHICH KEEPS CONDITIONS UNFAVORABLE FOR STRATUS. FOLLOWED
A BLEND OF THE LOCAL HIRES GUIDANCE MEMBERS AND THE SREF FOR SKY
COVER AND CLOUD CEILING FORECASTS. BOTH OF THESE GUIDANCE SUITES
SUGGEST THE WIDESPREAD STRATUS REACHES DOWN TO ABOUT THE I-4
CORRIDOR...AND THEN RETREATS AGAIN FRIDAY MORNING. THIS STRATUS WILL
NOT MAKE MUCH OF AN IMPACT TO THE SENSIBLE WEATHER...BUT WILL BE
MORE OF AN AVIATION CONCERN.
FRIDAY...
SURFACE TROUGH TO OUR EAST TODAY WILL MIGRATE ACROSS THE PENINSULA
AND BE ALIGNED OVER THE EASTERN GULF AND FL WEST COAST BY THE SECOND
HALF OF FRIDAY. THIS SURFACE TROUGH WILL PROVIDE THE FOCUS FOR WHAT
APPEARS TO BE AN ACTIVE AFTERNOON OF SHOWERS AND STORMS ACROSS THE
ENTIRE FORECAST AREA. OVERALL THE MORNING HOURS ARE EXPECTED TO BE
MAINLY DRY. EVEN IF THE STRATUS DOES SET IN OVER OUR NORTHERN ZONES
TONIGHT...WOULD EXPECT IT TO BURN OFF/DISSIPATE EARLIER THAN TODAY
AND ALLOW FOR GOOD DIURNAL HEATING. THIS HEATING WILL COMBINE WITH
WHAT IS FORECAST BY THE NWP GUIDANCE TO BE A VERY MOIST COLUMN (PW
VALUES WELL OVER 2")...AND THE LOW LEVEL FOCUS ALONG THE SURFACE
TROUGH TO FIRE OFF NUMEROUS SHOWERS AND STORMS AFTER 1-2PM. THESE
STORMS WILL MIGRATE WESTWARD TOWARD THE COAST...AND AREAL COVERAGE
WHEN LOOKING AT THE ENTIRE AFTERNOON LOOKS LIKE IT WILL BE HIGH. SO
ANTICIPATE A ROUND OR 2 OF SHOWERS DURING THE SECOND HALF OF FRIDAY
IF FOR ANY OUTDOOR PLANS. THE VERY MOIST COLUMN DOES RESULT IN POOR
LAPSE RATES...SO UNLIKELY THAT STRONG STORMS WILL BE AN ISSUE...BUT
RATHER HEAVY RAINFALL POTENTIAL IS THE LARGER THREAT. THIS THREAT IS
ESPECIALLY TRUE GIVEN THE LOCALIZED HEAVY RAINFALL TOTALS THAT HAVE
FALLEN THE PAST SEVERAL DAYS IF PLACES LIKE HIGHLANDS AND LEVY
COUNTIES.
&&
.LONG TERM (FRIDAY NIGHT - NEXT THURSDAY)...
MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT SHOWING UPPER
LEVEL RIDGING BUILDING OVER THE PENINSULA LATE IN THE WEEK AND OVER
THE UPCOMING WEEKEND. THE UPPER LEVEL RIDGING WILL THEN BREAK
DOWN EARLY NEXT WEEK IN RESPONSE TO UPPER LEVEL TROUGHING MOVING
ACROSS THE DEEP SOUTH AND INTO THE SOUTHEAST STATES...WITH UPPER
LEVEL RIDING REBUILDING ACROSS THE AREA DURING THE MIDDLE OF NEXT
WEEK. AT THE SURFACE...A FRONTAL BOUNDARY WILL REMAIN ACROSS NORTH
FLORIDA AND THE NORTHERN GULF COAST REGION OVER THE UPCOMING WEEKEND
AND INTO EARLY NEXT WEEK. THE FRONTAL BOUNDARY WILL THEN SLOWLY
SHIFT BACK SOUTHWARD AND INTO CENTRAL PORTION OF THE PENINSULA BY
THE MIDDLE OF NEXT WEEK.
AS FOR FORECAST DETAILS...PLENTY OF DEEP LAYER MOISTURE WILL REMAIN
IN PLACE THROUGH THE PERIOD...RESULTING IN SCATTERED TO NUMEROUS
MAINLY AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS EACH DAY.
TEMPERATURES ARE EXPECTED TO REMAIN CLOSE TO NORMAL THROUGH THE
PERIOD.
&&
.AVIATION...
STRATUS WAS STUBBORN BUT HAS MOSTLY BROKEN DOWN INTO A SCT-BKN
CUMULUS FIELD AROUND THE TERMINALS. SHOWERS AND STORMS ARE
DEVELOPING EAST OF THE TERMINALS AND WILL BE APPROACHING INTO THE
LATER AFTERNOON HOURS. AWAY FROM ANY STORMS...VFR CONDITIONS WILL
PREVAIL. LOOKS LIKE A CLOSE CALL FOR ANOTHER ROUND OF STRATUS
BUILDING DOWN TOWARD KTPA/KLAL OVERNIGHT. HAVE INCLUDED MVFR CIGS IN
THE TAFS LATE TONIGHT FOR KSRQ/KTPA/KPIE/KLAL TO START A TREND DOWN.
CONFIDENCE IN THE EVENT REACHING THE CENTRAL PENINSULA IS NOT HIGH
ENOUGH AT THIS TIME TO INCLUDE IFR MENTION. HOWEVER...IF THE STRATUS
DOES OCCUR...THEN CONDITIONS ARE MORE LIKELY TO BE IN THE IFR RANGE
THROUGH MID MORNING FRIDAY.
&&
.MARINE...
AN INVERTED TROUGH MOVING WESTWARD OVER SOUTHERN FLORIDA COMBINED
WITH A WEAKENING FRONTAL BOUNDARY OVER FLORIDA WILL PRODUCE
SCATTERED TO NUMEROUS SHOWERS AND STORMS OVER THE COASTAL WATERS.
WINDS WILL REMAIN OUT OF A NORTHEAST THROUGH EAST DIRECTION LESS
THAN 15 KNOTS AND SEAS LESS THAN 3 FEET. THE ONLY EXPECTED HAZARDS
FOR THE REMAINDER OF THE WEEK AND INTO THE WEEKEND WILL BE HIGHER
WINDS AND SEAS IN THE VICINITY OF THUNDERSTORMS.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS ARE EXPECTED THROUGH THE
WEEKEND. THE PATTERN WILL BECOME MORE SUMMER-LIKE OVER THE NEXT FEW
DAYS WITH MAINLY AFTERNOON AND EVENING SHOWERS AND STORMS. RELATIVE
HUMIDITY VALUES WILL REMAIN WELL ABOVE CRITICAL LEVELS.
PATCHY GROUND FOG IS POSSIBLE EACH OF THE NEXT FEW MORNING...HOWEVER
NO WIDESPREAD FOG OR VISIBILITY ISSUES ARE ANTICIPATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 74 88 75 90 / 40 70 50 60
FMY 74 89 75 92 / 20 70 40 70
GIF 73 88 74 91 / 20 60 30 50
SRQ 74 88 74 90 / 40 70 40 50
BKV 72 88 71 90 / 20 70 50 70
SPG 77 88 77 89 / 40 70 50 50
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/FIRE WX...MROCZKA
LONG TERM...JELSEMA
MARINE...WYNN
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
139 PM EDT THU SEP 25 2014
.AVIATION...
SHOWERS AND EVEN A FEW THUNDERSTORMS HAVE DEVELOPED OVER THE EAST
COAST METRO AREAS EARLY THIS AFTERNOON. THIS ACTIVITY WILL MOVE
WEST INTO THE INTERIOR AREAS AND WEST COAST METRO AREAS LATE THIS
AFTERNOON INTO THE EARLY EVENING HOURS. SO WILL KEEP VCTS IN ALL
OF THE TAF SITES FOR THIS AFTERNOON EXCEPT FOR VCSH FOR
KMIA...KFLL...AND KOPF TAF SITES DUE TO THE WORK OVER ATMOSPHERE
FROM THE EARLIER THUNDERSTORMS. VCSH WILL CONTINUE AT ALL OF THE
EAST COAST TAF SITES TONIGHT DUE TO THE POSSIBLE SHOWERS WORKING
INTO THE THESE TAF SITES FROM THE ATLANTIC WATERS. THE WINDS WILL
ALSO BE FROM THE EASTERLY DIRECTION AT 5 TO 10 KNOTS THIS
AFTERNOON DECREASING TO AROUND 5 KNOTS TONIGHT.
THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR CONDITIONS THIS
AFTERNOON INTO TONIGHT...AS ANY SHOWERS AND THUNDERSTORMS THAT DO
MOVE OVER THE TAF SITES WILL BE VERY SHORT IN TIME. HOWEVER...WHEN
THE SHOWERS AND THUNDERSTORMS MOVE OVER THE TAF SITES THE CEILING
WILL FALL DOWN INTO THE MVFR CONDITIONS.
KAPF TAF SITE COULD ALSO SEE MVFR OR EVEN IFR CONDITIONS IN THE
CEILING AND VIS TOWARD SUNRISE ON FRIDAY...DUE TO THE LOW CLOUDS
OR EVEN FOG COMING FROM THE INTERIOR AREAS ON THE EASTERLY WIND
FLOW. HOWEVER...WILL NOT REDUCED THE VIS OR CEILING AT KAPF TAF
SITE AT THIS TIME AS THE UNCERTAINLY IS HIGH AT THIS TIME.
&&
.AVIATION...54/BNB
.PREV DISCUSSION... /ISSUED 929 AM EDT THU SEP 25 2014/
UPDATE...MORNING ANALYSIS OF SOUNDING, SYNOPTIC ENVIRONMENT AND
ASSESSMENT OF THE LATEST TRENDS IN THE HIGH RESOLUTION MODELS
WARRANTS A LOWERING OF POPS FOR THE EAST COAST METROPOLITAN AREAS
FOR TODAY. FOCUS OF CONVECTION LOOKS TO BE ACROSS THE INTERIOR-
GULF COAST. LATEST HRRR RUN SHOWS ALMOST NO ACTIVITY AFFECTING THE
EAST COAST METRO AREAS. WHILE POSSIBLE, DECIDED IT PRUDENT TO
LOWER POPS JUST A CATEGORY TO SCATTERED FOR THE EAST COAST METRO.
THERE IS AN AREA OF CONVECTION OFF THE SOUTHERN MIAMI-DADE COAST
MOVING WESTWARD. THIS COULD MOVE ONSHORE AND/OR SPAWN OUTFLOW TO
IGNITE SCATTERED ACTIVITY, SO AM KEEPING SCATTERED TSTORMS IN THE
FORECAST THERE WITH MORE NUMEROUS ACTIVITY LATER THIS AFTERNOON
FURTHER WEST. MAIN POTENTIAL IMPACT FROM THE TSTORMS TODAY WILL BE
ISOLATED STREET FLOODING DUE TO HIGH RAINFALL RATES. /GREGORIA
&&
PREV DISCUSSION... /ISSUED 806 AM EDT THU SEP 25 2014/
UPDATE...UPDATED THE FORECAST TO REFLECT DELAYED SHOWER AND
THUNDERSTORM ACTIVITY AS KAMX RADAR IS QUIET THIS MORNING.
HOWEVER, THIS IS EXPECTED TO CHANGE BY AFTERNOON WITH CONVERGENCE
BEHIND A SURFACE TROUGH CURRENTLY SITUATED JUST OFF THE SE
FLORIDA COAST. THIS TROUGH WILL MOVE WEST WITH A PREVAILING MOIST
(GPS MET DATA SHOWING PW AROUND 2 INCHES) ESE STEERING WIND FLOW
THIS AFTERNOON. ALTHOUGH SHOWER/TSTORMS LOO TO CONCENTRATE ACROSS
THE INTERIOR- GULF COAST THIS AFTERNOON, DID KEEP HIGH POPS FOR
THE EAST COAST AS WELL AS THE ACTIVITY WILL BE ON THE MOVE
POTENTIALLY COVERING A WIDER AREA. UPDATES OUT. /GREGORIA
&&
PREV DISCUSSION... /ISSUED 730 AM EDT THU SEP 25 2014/
UPDATE...
THE WINDS OVER SOUTH FLORIDA TAF SITES WILL BE EASTERLY AT 5 TO 10
KNOTS THIS MORNING BEFORE INCREASING TO AROUND 10 KNOTS THIS
AFTERNOON. SHOWERS SHOULD START TO DEVELOP OVER THE TAF SITES
BETWEEN 13Z AND 16Z THIS MORNING BEFORE THE TREAT OF THUNDERSTORMS
COME INTO PLAY FOR THE AFTERNOON HOURS. SO WILL PUT IN VCSH FOR
ALL OF THE TAF SITES FROM 13Z UNTIL 16Z...THEN VCTS FROM 16Z UNTIL
23Z.
THE CEILING AND VIS WILL REMAIN IN THE VFR CONDITIONS FOR ALL OF
THE TAF SITES FOR TODAY...AS THE TIMING OF THE SHOWERS AND
THUNDERSTORMS IS NOT KNOWN AT THIS TIME. ONCE THE SHOWERS AND
THUNDERSTORMS TO START TO FORM THEN A TEMPO GROUP WILL BE ADDED
FOR THE TAF SITES FOR THE REDUCED VIS AND CEILING.
THE ONLY EXCEPTION TO THIS IS THAT THERE IS CURRENTLY IFR
CONDITIONS IN THE CEILING AT KAPF TAF SITE EARLY THIS MORNING.
THESE LOW CEILINGS SHOULD BURN OFF DURING THE NEXT HOUR. SO WILL
PUT IN A TEMPO GROUP FOR IFR CEILINGS UNTIL 13Z.
&&
AVIATION...54/BNB
PREV DISCUSSION... /ISSUED 255 AM EDT THU SEP 25 2014/
SHORT TERM (TODAY-SATURDAY)...
THE CLOSED MID/UPPER LEVEL LOW THAT HAS BEEN MEANDERING AROUND THE
SOUTHEAST STATES IS BEGINNING TO OPEN UP EARLY THIS MORNING IN
RESPONSE TO A DEEPENING TROUGH OVER THE NORTHERN PLAINS STATES. THE
LOW IS LIFTING TO THE NORTHEAST AND AS OF 06Z WAS CENTERED OVER WEST
VIRGINIA WITH ITS TRAILING AXIS STILL EXTENDING SOUTHWARD ACROSS THE
FLORIDA PENINSULA. A SURFACE TROUGH WAS LOCATED JUST EAST OF THE
PENINSULA FROM NEAR GRAND BAHAMA TO THE DELMARVA PENINSULA. THESE
FEATURES ARE COMBINING TO AID IN THE CONTINUATION OF NUMEROUS SHOWERS
AND A FEW THUNDERSTORMS OVER THE WESTERN BAHAMAS TO JUST OFF OUR
SOUTHEAST COAST. AS THE LOW LIFTS TO THE NORTHEAST TODAY, AN
ATLANTIC RIDGE WILL BEGIN TO BUILD TO THE WEST WITH FORECAST
SOUNDINGS SHOWING DEEP EAST-SOUTHEAST FLOW DEVELOPING BY 12Z THIS
MORNING. THIS ALREADY APPARENT WITH A SLOW WESTWARD SHIFT TO THE
RAIN SHIELD TO OUR EAST AND THERE COULD BE SOME LOCALIZED HEAVY
RAINS EARLY THIS MORNING OVER PORTIONS OF THE EAST COAST METRO
AREAS, ESPECIALLY FROM EXTREME NORTHEAST MIAMI-DADE COUNTY NORTH
TO PALM BEACH COUNTY. THE SURFACE TROUGH WILL BEGIN TO SHIFT TO
THE NORTHWEST THROUGH FRIDAY AND WITH THE DEEP SOUTHEAST FLOW
BEGINNING TO TAKE SHAPE, MOST ACTIVITY WILL ALSO SHIFT TO THE WEST
WITH THE INTERIOR AND WEST COAST REGIONS SEEING MORE ACTION BOTH
TODAY AND FRIDAY.
BY SATURDAY, THE UPPER RIDGE WILL BE WELL ESTABLISHED OVER THE
FLORIDA PENINSULA WITH THE SURFACE TROUGH DRAPED ACROSS THE
NORTHEAST GULF AND INTO NORTH FLORIDA. WITHIN THE EASTERLY
CIRCULATION AROUND THE RIDGE, DRIER AIR FROM THE CENTRAL AND EASTERN
BAHAMAS WILL WORK ITS WAY TOWARDS SOUTH FLORIDA WITH FORECAST
SOUNDINGS SHOWING PWAT LOWERING TO A RANGE OF 1.65-1.75 INCHES ON
SATURDAY. THIS WILL LIMIT THE CONVECTIVE ACTIVITY ALONG THE EAST
COAST WITH MORE TYPICAL AFTERNOON STORMS ACROSS THE INTERIOR AND
SOUTHWEST COAST.
LONG TERM (SUNDAY-WEDNESDAY)...
LITTLE CHANGE IS FORESEEN ON SUNDAY WITH THE UPPER RIDGE REMAINING
NEARLY STATIONARY ACROSS THE PENINSULA. THE MID/UPPER TROUGH
CURRENTLY IN THE NORTHERN PLAINS AREA WILL CONTINUE TO DEEPEN INTO
THE SOUTHEAST STATES ON MONDAY AND INTO THE FIRST PART OF NEXT WEEK.
THE RIDGE AS A RESULT WILL RAPIDLY SHIFT BACK TO THE EAST AND SOUTH
ALLOWING FOR A RETURN TO DEEP WESTERLY FLOW. THIS WILL SHIFT THE
SHOWERS AND STORMS BACK TO THE INTERIOR AND EAST COAST. AT THIS
TIME, IT IS A LITTLE UNCERTAIN HOW MUCH RETURN MOISTURE OCCURS BUT
FORECAST SOUNDINGS FROM BOTH THE GFS AND ECMWF SHOW PWAT CLIMBING
BACK CLOSE TO 2" SO THERE COULD BE SOME THREAT FOR LOCALLY HEAVY
RAINS ONCE AGAIN OVER THE EAST COAST METRO AREAS EARLY NEXT WEEK.
MARINE...
A LIGHT TO MODERATE EASTERLY WIND FLOW WILL CONTINUE FOR THE REST
OF THIS WEEK INTO THE UPCOMING WEEKEND. SEAS WILL GENERALLY BE 2-3
FEET IN THE ATLANTIC WATERS AND 2 FEET OR LESS OVER THE GULF.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 76 86 78 / 40 40 50 20
FORT LAUDERDALE 87 78 88 79 / 40 40 50 20
MIAMI 87 77 87 79 / 40 40 50 20
NAPLES 88 76 88 76 / 70 50 70 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...54/BNB
LONG TERM....57/DG
AVIATION...54/BNB
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1000 AM EDT THU SEP 25 2014
.UPDATE (REST OF TODAY AND TONIGHT)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWING A COMPLEX AND SLOW
MOVING UPPER LEVEL PATTERN ACROSS THE CONUS. DEFINED NORTHERN STREAM
FLOW ARRIVES ALONG THE PACIFIC COAST AND RIDGES WELL UP INTO WESTERN
CANADA BEFORE FLATTENING OUT AND BECOME MORE ZONAL TO THE NORTH OF
THE GREAT LAKES AND NEW ENGLAND. A DISPLACED SHORTWAVE TROUGH
CONTINUES TO PIVOT NORTHWARD THROUGH THE OHIO VALLEY/NE STATES
AROUND THE WESTERN PERIPHERY OF A LARGE UPPER RIDGE ACROSS THE
WESTERN ATLANTIC. OUR FORECAST AREA ALSO RESIDES WITHIN THE WESTERN
CIRCULATION OF THIS UPPER RIDGE ALLOWING ABUNDANT MID/UPPER LEVEL
MOISTURE TO STREAM BACK NORTHWARD OVERHEAD.
25/12Z SOUNDING PROFILE HAS CERTAINLY MOISTENED UP IN THE MIDDLE
LEVELS COMPARED TO WEDNESDAY MORNING...WITH PW VALUES BACK UP NEAR
2". SEEING PLENTY OF LOWER STRATUS AROUND THE REGION THIS MORNING
WITHIN THE NE FLOW. THIS STRATUS LAYER IS VERY SHALLOW PER SOUNDING
PROFILE...BUT IS CHARACTERIZED BY A WELL DEFINED INVERSION. THE
STATUS WAS TOUGH TO BREAK ON WEDNESDAY IN SOME SPOTS AND LIKELY WILL
SEE A SIMILAR SCENARIO TODAY...ESPECIALLY FROM THE I-4 CORRIDOR AND
NORTHWARD.
AT THE SURFACE...AS MENTIONED ABOVE...LOOKING AT NE FLOW BETWEEN A
LARGE RIDGE OF HIGH PRESSURE OVER THE DEEP SOUTH...AND AN INVERTED
SURFACE TROUGH OFF THE FL EAST COAST. THIS GRADIENT WILL KEEP THE NE
FLOW GOING AND GIVES SOME CONFIDENCE TO THE SLOW MODIFICATION OF THE
LOW LEVEL AIRMASS OVER THE NORTHERN HALF OF THE FORECAST AREA.
WITH ALL THIS IN MIND...HAVE DECIDED TO MAKE SOME CHANGES TO THE
RAINFALL FORECAST CHANCES TO THE NORTH OF MANATEE/HARDEE/HIGHLANDS
COUNTIES. SOUTH OF HILLSBOROUGH/POLK COUNTIES...THE AIRMASS SHOULD
BE ABLE TO BEGIN MODIFYING THIS MORNING (ALREADY SEEING THIS DOWN
TOWARD FORT MYERS)...AND FEEL CONVECTIVE CHANCES ARE STILL QUITE
HIGH FOR THIS AFTERNOON (ALTHOUGH BEST CHANCES WILL BE LATE
AFTERNOON/EARLY EVENING). THE FORECAST GRIDS WILL SHOW A FAIRLY
TIGHT GRADIENT IN THE RAINFALL CHANCES FURTHER NORTH AS WE GET
DEEPER INTO THE STABLE LOW LEVEL AIRMASS. HAVE REMOVED THE LIKELY
POPS FROM THE TAMPA BAY AREA IN FAVOR OF 30-50% RAIN CHANCES AND
CONTINUED THAT TREND UP INTO PASCO AND HERNANDO COUNTIES. LARGER
SCALE GUIDANCE OFTEN STRUGGLES IN THESE SCENARIOS WHEN MUCH OF THE
COLUMN IS FAVORABLE FOR CONVECTION...BUT THE LOWEST LEVELS ARE NOT.
THE CONVECTIVE SCHEMES STILL FIRE...AND THE MODEL APPEARS MUCH MORE
AGGRESSIVE THAN IS LIKELY TO HAPPEN IN REALITY. FEEL THIS IS
HAPPENING ACROSS TAMPA BAY TODAY. THE ENSEMBLE SUITE OF HIRES
CONVECTION ALLOWING MODELS AGREES WITH THIS TIGHT RAINFALL CHANCE
GRADIENT ALONG AND JUST SOUTH OF THE I-4 CORRIDOR AND WAS FOLLOWED
MORE CLOSELY FOR THIS UPDATE FORECAST PACKAGE. IN FACT...IF THIS
SUITE OF GUIDANCE WERE TO VERIFY...THEN WE HAVE NOT DECREASED RAIN
CHANCES ENOUGH NORTH OF MANATEE AND HARDEE COUNTIES. WE WILL ALL
KNOW IF THIS FORECAST TREND IS CORRECT IN A FEW HOURS...BUT BASED ON
PAST EXPERIENCES AND HOW WELL THE CONVECTIVE ALLOWING GUIDANCE DID
ON WEDNESDAY...FEEL THIS IS THE APPROPRIATE DIRECTION TO GO WITH THE
FORECAST.
TONIGHT...
SCT SHOWERS AND STORMS PUSH OFF THE COAST THIS EVENING WITH MOST OF
THE AREA SEEING A DRY OVERNIGHT AFTER 1-2Z. THE SETUP AGAIN LOOKS
FAVORABLE FOR THE DEVELOPMENT AND SOUTHWARD ADVECTION OF LOW LEVEL
STRATUS. FOLLOWED THE LOCAL HIRES GUIDANCE MEMBERS CLOSELY AS
THEY ALL ARE QUITE AGGRESSIVE WITH WIDESPREAD IFR CIGS DEVELOPING
NORTH OF TAMPA BAY...AND AREAS OF IFR CIGS FURTHER SOUTH.
&&
.AVIATION...
LOWER STRATUS HANGING IN TO THE NORTH OF KPGD THIS MORNING. THE
STRATUS HAS BROKEN FURTHER SOUTH...AND GENERALLY LOOKING AT VFR
CONDITIONS FOR KFMY/KRSW UNTIL NUMEROUS SHOWERS AND STORMS ARRIVE
LATE IN THE DAY. MAY TAKE ANOTHER COUPLE OF HOURS TO ERODE THE
STRATUS FURTHER NORTH INTO KSRQ/KTPA/KLAL...AND WILL BE EXTENDING
THE TEMPO IFR CONDITIONS THROUGH MIDDAY FOR THESE TERMINALS.
THEREAFTER...SHOULD SEE CONTINUES GO VFR FOR THE AFTERNOON FOLLOWED
BY SCT STORMS LATE IN THE DAY. UNDER ROUND OF AREAS OF LOWER STRATUS
SEEMS LIKELY FOR TONIGHT...ESPECIALLY NORTH OF KPGD.
&&
.MARINE...
A TROPICAL WAVE MOVING WEST THROUGH THE FLORIDA STRAITS WILL
COMBINE WITH A WEAK FRONTAL BOUNDARY LINGERING OVER FLORIDA. THIS
WILL CREATE IDEAL CONDITIONS FOR NUMEROUS SHOWERS AND THUNDERSTORMS
FOR THE NEXT COUPLE OF DAYS. WIND AND SEAS WILL REMAIN GENERALLY
UNDER 15 KNOTS AND THE MAIN HAZARDS WILL CONTINUE TO BE HIGHER WINDS
AND SEAS IN THE VICINITY OF THUNDERSTORMS.
&&
.HYDROLOGY...
POTENTIAL FOR LOCALLY HEAVY RAIN NEXT COUPLE OF DAYS WILL
INCREASE THE THREAT FOR RIVER FLOODING TO DEVELOP ACROSS WEST
CENTRAL FLORIDA. THE LITTLE MANATEE AND MYAKKA RIVERS ALONG WITH
CYPRESS CREEK ARE ALL RUNNING WITHIN 2 FEET OF FLOOD STAGE...AND
ADDITIONAL HEAVY RAIN COULD CAUSE THESE RIVERS TO RISE ABOVE FLOOD
STAGE OVER THE NEXT COUPLE OF DAYS. FLOODING COULD ALSO DEVELOP ON
THE MANATEE...ALAFIA...OR PEACE RIVERS IF HEAVY RAIN BECOMES
FOCUSED IN THOSE RIVER BASIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 88 74 88 75 / 40 40 70 50
FMY 88 74 89 75 / 80 20 70 40
GIF 88 73 88 74 / 50 20 60 30
SRQ 87 74 88 74 / 50 40 70 40
BKV 88 72 88 71 / 30 20 70 50
SPG 88 77 88 77 / 30 40 70 50
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
MARINE...DOUGHERTY
HYDROLOGY...OGLESBY
AREA FORECAST DISCUSSION
NWS MIAMI FL
929 AM EDT THU SEP 25 2014
.UPDATE...MORNING ANALYSIS OF SOUNDING, SYNOPTIC ENVIRONMENT AND
ASSESSMENT OF THE LATEST TRENDS IN THE HIGH RESOLUTION MODELS
WARRANTS A LOWERING OF POPS FOR THE EAST COAST METROPOLITAN AREAS
FOR TODAY. FOCUS OF CONVECTION LOOKS TO BE ACROSS THE INTERIOR-
GULF COAST. LATEST HRRR RUN SHOWS ALMOST NO ACTIVITY AFFECTING THE
EAST COAST METRO AREAS. WHILE POSSIBLE, DECIDED IT PRUDENT TO
LOWER POPS JUST A CATEGORY TO SCATTERED FOR THE EAST COAST METRO.
THERE IS AN AREA OF CONVECTION OFF THE SOUTHERN MIAMI-DADE COAST
MOVING WESTWARD. THIS COULD MOVE ONSHORE AND/OR SPAWN OUTFLOW TO
IGNITE SCATTERED ACTIVITY, SO AM KEEPING SCATTERED TSTORMS IN THE
FORECAST THERE WITH MORE NUMEROUS ACTIVITY LATER THIS AFTERNOON
FURTHER WEST. MAIN POTENTIAL IMPACT FROM THE TSTORMS TODAY WILL BE
ISOLATED STREET FLOODING DUE TO HIGH RAINFALL RATES. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 806 AM EDT THU SEP 25 2014/
UPDATE...UPDATED THE FORECAST TO REFLECT DELAYED SHOWER AND
THUNDERSTORM ACTIVITY AS KAMX RADAR IS QUIET THIS MORNING.
HOWEVER, THIS IS EXPECTED TO CHANGE BY AFTERNOON WITH CONVERGENCE
BEHIND A SURFACE TROUGH CURRENTLY SITUATED JUST OFF THE SE
FLORIDA COAST. THIS TROUGH WILL MOVE WEST WITH A PREVAILING MOIST
(GPS MET DATA SHOWING PW AROUND 2 INCHES) ESE STEERING WIND FLOW
THIS AFTERNOON. ALTHOUGH SHOWER/TSTORMS LOO TO CONCENTRATE ACROSS
THE INTERIOR- GULF COAST THIS AFTERNOON, DID KEEP HIGH POPS FOR
THE EAST COAST AS WELL AS THE ACTIVITY WILL BE ON THE MOVE
POTENTIALLY COVERING A WIDER AREA. UPDATES OUT. /GREGORIA
PREV DISCUSSION... /ISSUED 730 AM EDT THU SEP 25 2014/
UPDATE...
THE WINDS OVER SOUTH FLORIDA TAF SITES WILL BE EASTERLY AT 5 TO 10
KNOTS THIS MORNING BEFORE INCREASING TO AROUND 10 KNOTS THIS
AFTERNOON. SHOWERS SHOULD START TO DEVELOP OVER THE TAF SITES
BETWEEN 13Z AND 16Z THIS MORNING BEFORE THE TREAT OF THUNDERSTORMS
COME INTO PLAY FOR THE AFTERNOON HOURS. SO WILL PUT IN VCSH FOR
ALL OF THE TAF SITES FROM 13Z UNTIL 16Z...THEN VCTS FROM 16Z UNTIL
23Z.
THE CEILING AND VIS WILL REMAIN IN THE VFR CONDITIONS FOR ALL OF
THE TAF SITES FOR TODAY...AS THE TIMING OF THE SHOWERS AND
THUNDERSTORMS IS NOT KNOWN AT THIS TIME. ONCE THE SHOWERS AND
THUNDERSTORMS TO START TO FORM THEN A TEMPO GROUP WILL BE ADDED
FOR THE TAF SITES FOR THE REDUCED VIS AND CEILING.
THE ONLY EXCEPTION TO THIS IS THAT THERE IS CURRENTLY IFR
CONDITIONS IN THE CEILING AT KAPF TAF SITE EARLY THIS MORNING.
THESE LOW CEILINGS SHOULD BURN OFF DURING THE NEXT HOUR. SO WILL
PUT IN A TEMPO GROUP FOR IFR CEILINGS UNTIL 13Z.
AVIATION...54/BNB
PREV DISCUSSION... /ISSUED 255 AM EDT THU SEP 25 2014/
SHORT TERM (TODAY-SATURDAY)...
THE CLOSED MID/UPPER LEVEL LOW THAT HAS BEEN MEANDERING AROUND THE
SOUTHEAST STATES IS BEGINNING TO OPEN UP EARLY THIS MORNING IN
RESPONSE TO A DEEPENING TROUGH OVER THE NORTHERN PLAINS STATES. THE
LOW IS LIFTING TO THE NORTHEAST AND AS OF 06Z WAS CENTERED OVER WEST
VIRGINIA WITH ITS TRAILING AXIS STILL EXTENDING SOUTHWARD ACROSS THE
FLORIDA PENINSULA. A SURFACE TROUGH WAS LOCATED JUST EAST OF THE
PENINSULA FROM NEAR GRAND BAHAMA TO THE DELMARVA PENINSULA. THESE
FEATURES ARE COMBINING TO AID IN THE CONTINUATION OF NUMEROUS SHOWERS
AND A FEW THUNDERSTORMS OVER THE WESTERN BAHAMAS TO JUST OFF OUR
SOUTHEAST COAST. AS THE LOW LIFTS TO THE NORTHEAST TODAY, AN
ATLANTIC RIDGE WILL BEGIN TO BUILD TO THE WEST WITH FORECAST
SOUNDINGS SHOWING DEEP EAST-SOUTHEAST FLOW DEVELOPING BY 12Z THIS
MORNING. THIS ALREADY APPARENT WITH A SLOW WESTWARD SHIFT TO THE
RAIN SHIELD TO OUR EAST AND THERE COULD BE SOME LOCALIZED HEAVY
RAINS EARLY THIS MORNING OVER PORTIONS OF THE EAST COAST METRO
AREAS, ESPECIALLY FROM EXTREME NORTHEAST MIAMI-DADE COUNTY NORTH
TO PALM BEACH COUNTY. THE SURFACE TROUGH WILL BEGIN TO SHIFT TO
THE NORTHWEST THROUGH FRIDAY AND WITH THE DEEP SOUTHEAST FLOW
BEGINNING TO TAKE SHAPE, MOST ACTIVITY WILL ALSO SHIFT TO THE WEST
WITH THE INTERIOR AND WEST COAST REGIONS SEEING MORE ACTION BOTH
TODAY AND FRIDAY.
BY SATURDAY, THE UPPER RIDGE WILL BE WELL ESTABLISHED OVER THE
FLORIDA PENINSULA WITH THE SURFACE TROUGH DRAPED ACROSS THE
NORTHEAST GULF AND INTO NORTH FLORIDA. WITHIN THE EASTERLY
CIRCULATION AROUND THE RIDGE, DRIER AIR FROM THE CENTRAL AND EASTERN
BAHAMAS WILL WORK ITS WAY TOWARDS SOUTH FLORIDA WITH FORECAST
SOUNDINGS SHOWING PWAT LOWERING TO A RANGE OF 1.65-1.75 INCHES ON
SATURDAY. THIS WILL LIMIT THE CONVECTIVE ACTIVITY ALONG THE EAST
COAST WITH MORE TYPICAL AFTERNOON STORMS ACROSS THE INTERIOR AND
SOUTHWEST COAST.
LONG TERM (SUNDAY-WEDNESDAY)...
LITTLE CHANGE IS FORESEEN ON SUNDAY WITH THE UPPER RIDGE REMAINING
NEARLY STATIONARY ACROSS THE PENINSULA. THE MID/UPPER TROUGH
CURRENTLY IN THE NORTHERN PLAINS AREA WILL CONTINUE TO DEEPEN INTO
THE SOUTHEAST STATES ON MONDAY AND INTO THE FIRST PART OF NEXT WEEK.
THE RIDGE AS A RESULT WILL RAPIDLY SHIFT BACK TO THE EAST AND SOUTH
ALLOWING FOR A RETURN TO DEEP WESTERLY FLOW. THIS WILL SHIFT THE
SHOWERS AND STORMS BACK TO THE INTERIOR AND EAST COAST. AT THIS
TIME, IT IS A LITTLE UNCERTAIN HOW MUCH RETURN MOISTURE OCCURS BUT
FORECAST SOUNDINGS FROM BOTH THE GFS AND ECMWF SHOW PWAT CLIMBING
BACK CLOSE TO 2" SO THERE COULD BE SOME THREAT FOR LOCALLY HEAVY
RAINS ONCE AGAIN OVER THE EAST COAST METRO AREAS EARLY NEXT WEEK.
MARINE...
A LIGHT TO MODERATE EASTERLY WIND FLOW WILL CONTINUE FOR THE REST
OF THIS WEEK INTO THE UPCOMING WEEKEND. SEAS WILL GENERALLY BE 2-3
FEET IN THE ATLANTIC WATERS AND 2 FEET OR LESS OVER THE GULF.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 76 86 78 / 40 40 50 20
FORT LAUDERDALE 87 78 88 79 / 40 40 50 20
MIAMI 87 77 87 79 / 40 40 50 20
NAPLES 88 76 88 76 / 70 50 70 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
110 AM EDT THU SEP 25 2014
.PREV DISCUSSION... /ISSUED 1054 PM EDT WED SEP 24 2014/
UPDATE...
WITH EXTENSIVE CLOUD COVER MOVING INTO THE AREA AND OVERRUNNING ON
THE ISENTROPIC LEVELS SEEING SOME MOISTENING OF THE LOW LEVEL BL.
AS A RESULT OVERNIGHT TEMPERATURES IN THE CLOUD COVER SHOULD BE
SLIGHTLY HIGHER THAN FORECAST. WENT AND RAISED THE LOWS ANYWHERE
FROM A DEGREE TO 4 DEGREES IN THIS AREA. ALSO HAD TO CHANGE THE
DEWPOINT TEMPERATURES. AT THIS TIME THE 00Z RUC SEEMED TO HAVE THE
BEST HANDLE ON THE DEWPOINTS AND OVERNIGHT LOW TEMPERATURES. USED
THAT MODEL AND INHOUSE WRF ALONG WITH TRENDS TO DECIDE AN INCREASE
IN THE TEMPS WAS WARRANTED. NO OTHER CHANGES OR UPDATES TO THE
FORECAST ARE EXPECTED AT THIS TIME.
ARG
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
WHILE MAIN FORECAST CONCERNS OF SHOWER CHANCES AND TEMPS ARE
RELATIVELY LOW IMPACT...SUBTLE DISCREPANCIES IN THE MODELS AND LACK
OF STRONG FORCING MAKES FOR A TRICKY OUTCOME. UPPER LOW AND BETTER
MOISTURE FIELD WILL CONTINUE TO DAMPEN AND LIFT NORTHEAST THOUGH
WAVES OF EASTWARD LOW LEVEL ATLANTIC MOISTURE ADVECTION WILL KEEP
EASTERN PORTIONS OF THE AREA CLOUDY WITH LIGHT SHOWERS POSSIBLE
THROUGH MUCH OF THE PERIOD. MAIN FORCING FOR ANY PRECIP WILL BE WITH
ISENTROPIC UPGLIDE AGAINST A STRONG CLASSICAL CAD WEDGE FROM A
1038MB PARENT HIGH SET TO PUSH EAST AND WEAKEN OFF THE NEW ENGLAND
COAST. HAVE GONE WITH SLIGHT POPS IN PORTIONS OF THE EAST FOR
THURSDAY AND THURSDAY NIGHT TRENDING BASED ON UPGLIDE ALONG THE NAM
300K THETA LEVEL AS HI-RES SOLUTIONS DO NOT HELP IN CONFIDENCE.
WOULD NOT BE SURPRISED IF TIMING AND EXTENT OF ANY SHOWERS CHANGES.
AT LEAST NO THUNDER CONCERNS GIVEN STABLE WEDGE ENVIRONMENT.
FOR TEMPS...WEDGE AND CLOUD COVERAGE SHOULD CONTINUE TO ALLOW FOR
BELOW NORMAL TEMPS ESPECIALLY FOR EASTERN PORTIONS OF THE AREA.
BLEND OF GUIDANCE PICKS UP ON SOME OF THIS...BUT THURSDAY HIGHS MAY
BE STILL TOO HIGH BASED ON HOW PORTIONS OF THE SOUTHEAST WAS
STRUGGLING TO GET EVEN OUT OF THE 60S TODAY.
BAKER
LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NO MAJOR CHANGES MADE IN THE EXTENDED FORECAST. MODELS ARE ARE
VERY SIMILAR TO WHAT WAS BEING ADVERTISED YESTERDAY AND THUS
CONFIDENCE IS INCREASING IN A DECENT RAIN EVENT VERY LATE INTO THE
WEEKEND INTO EARLY NEXT WEEK. LEADING UP TO THIS EVENT...BIG
QUESTION WILL BE HOW MUCH OF THE SE GEORGIA AND NE FLORIDA COASTAL
CONVERGENCE ACTIVITY WILL TRANSLATE INTO THE LOCAL AREA IN LOW
LEVEL EASTERLY FLOW REGIME. MOST OF THE TIME IN SUCH
PATTERNS...THE SHOWERS REMAIN CLOSER TO THE COAST THAN MODELS
SUGGEST AND FOR THIS FORECAST WILL FOLLOW SUIT AND LIMIT AREAL
COVERAGE TO THE FAR SOUTHEAST CORNER OF THE FORECAST AREA AND
LIMIT POPS TO 20 PERCENT IN GENERAL.
NORMALLY WOULD NOT HAVE MUCH CONFIDENCE IN SUCH A COMPLICATED
SETUP WITH CLOSED UPPER LOW TRAPPED WITHIN LARGE SCALE UPPER
RIDGE. BUT IN THIS CASE...THINKING THE ONLY VARIABLE WHICH COULD
RADICALLY CHANGE THE FORECAST IS THE TIMING OF THE UPPER LOW
EJECTING OUT. WHETHER THIS IS SUNDAY OR MONDAY OR LATER...IT
APPEARS LIKELY IT WILL HAPPEN EVENTUALLY AND WHEN IT DOES WE CAN
EXPECT A DEVELOPING UPPER LEVEL DIFFLUENT PATTERN TO DEVELOP ALONG
WITH A GOOD FETCH OFF HE GULF PRODUCING PWATS IN EXCESS OF 2
INCHES. THIS COMBINATION SHOULD LEAD TO AT LEAST LIKELY COVERAGE
WITH MOST MODELS INDICATING CATEGORICAL POPS WITH SUSTAINED
MODERATE RAINFALL OVER A 24 HOUR PERIOD. WILL FOLLOW SUIT WITH 60
POPS FOR A WIDE EXPANSE AND FAVOR SLIGHTLY THE GFS QUICKER
PROGRESSION AS LATEST ECMWF HAS ACTUALLY TRENDED TOWARD THIS
SOLUTION.
DEESE/01
&&
.AVIATION...
06Z UPDATE...
IFR-MVFR CEILINGS INCREASING ACROSS THE TAF AREA. IMPROVEMENT TO
VFR IS EXPECTED TOWARD MIDDAY AND EARLY AFTERNOON. CONCERN FOR
SOME VSBY RESTRICTIONS OVER THE EASTERN AREA DUE TO DRIZZLE AND
POSSIBLY FOG. MAINLY NE WINDS 10 KTS OR LESS.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE FOR CEILINGS AND IMPROVEMENT TIMES TODAY.
HIGH CONFIDENCE ALL OTHER ELEMENTS.
BDL
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 77 62 78 63 / 20 20 20 10
ATLANTA 78 65 79 65 / 10 20 20 10
BLAIRSVILLE 77 58 77 58 / 10 20 20 5
CARTERSVILLE 81 60 81 63 / 10 10 10 10
COLUMBUS 80 65 82 67 / 10 10 10 20
GAINESVILLE 76 63 77 63 / 10 20 20 10
MACON 78 64 82 65 / 10 10 20 20
ROME 81 58 82 62 / 10 10 10 5
PEACHTREE CITY 78 60 80 62 / 10 10 10 10
VIDALIA 78 67 83 69 / 20 20 20 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AVIATION...BDL
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
302 PM CDT THU SEP 25 2014
.DISCUSSION...
239 PM CDT
MEAN TROUGHING ACROSS THE WESTERN CONUS WILL CONTINUE TO PROMOTE
DOWNSTREAM RIDING AND POSITIVE HEIGHT ANOMALIES ACROSS THE MUCH OF
THE EASTERN HALF OF THE COUNTRY INTO THE MIDDLE OF NEXT WEEK.
OVERALL...THIS WILL CONTINUE TO PRODUCE A LONG STRETCH OF DRY AND
MILD WEATHER THROUGH MUCH OF THE PERIOD.
WATER VAPOR IMAGERY EARLY THIS AFTERNOON INDICATES THE PRESENCE OF A
MID/UPPER LEVEL CIRCULATION ACROSS IOWA...WHICH REMAINS CUTOFF FROM
THE MAIN BELT OF WESTERLIES ACROSS SOUTHERN CANADA. THIS FEATURE HAS
ONLY LEAD TO SOME MID AND HIGHER LEVEL CLOUDINESS ACROSS THE AREA
TODAY. HOWEVER...THE LOWER LEVELS ARE TO DRY FOR MORE THAN AN
ISOLATED SPRINKLE TO REACH THE SURFACE.
TEMPERATURES TOMORROW LOOK TO BE A COUPLE OF DEGREES WARMER THAN
TODAY...PRIMARILY IN THE UPPER 70S TO LOW 80S...WITH THE EXCEPTION OF
SLIGHTLY COOLER CONDITIONS NEAR LAKE MICHIGAN DUE TO THE AFTERNOON
ONSHORE FLOW/LAKE BREEZE. IT APPEARS THAT WE WILL MAINLY BE ON
REPEAT MODE FOR SATURDAY THROUGH AT LEAST WEDNESDAY OF NEXT WEEK...AS
TEMPERATURES REMAIN ABOVE AVERAGE...NEAR TO SLIGHTLY ABOVE 80
DEGREES AT TIMES. DUE TO THE DRYNESS OF THE ATMOSPHERE UNDER THE
UPPER RIDGE...I HAVE RAISED TEMPERATURES A COUPLE OF DEGREES THROUGH
THE PERIOD...WITH TEMPERATURES LIKELY TO GET A BIT WARMER THAN THAT
ADVERTISED BY MOST RAW MODEL GUIDANCE.
ONE CAVEAT TO THIS REPEATED WEATHER COULD BE ON TUESDAY. SOME MODEL
GUIDANCE IS ADVERTISING A COLD FRONT SLIPPING DOWN THE LAKE OVER THE
AREA IN RESPONSE TO A DIGGING UPPER LEVEL DISTURBANCE OVER THE GREAT
LAKES. HOWEVER...MODELS AND ENSEMBLES SHOW A GOOD AMOUNT OF SPREAD
WITH THE TIMING AND THE STRENGTH OF THIS DISTURBANCE...SO CONFIDENCE
IS LOW AT THIS TIME. EVEN IF THIS WERE TO MATERIALIZE...IT WOULD ONLY
RESULT IN SOME COOLER CONDITIONS DURING THE DAY TUESDAY UNDER
NORTHEASTERLY ONSHORE FLOW.
OTHERWISE...THE WEATHER PATTERN DOES LOOK TO BECOME MORE ACTIVE
LATER NEXT WEEK...WITH GUIDANCE AND ENSEMBLES ADVERTISING A STOUT
DISTURBANCE DIGGING OVER THE PLAINS STATES. THIS LOOKS TO RESULT IN
OUR NEXT CHANCES FOR SHOWERS/STORMS. HOWEVER...WITH A DECENT
POSSIBILITY OF THIS SYSTEM RUNNING SLOWER THAN WHAT THE GFS CURRENTLY
INDICATES...THE SYSTEM MAY NOT IMPACT THE REGION UNTIL VERY LATE
NEXT WEEK...RIGHT AT OR JUST BEYOND THE CURRENT 7 DAY FORECAST
PERIOD. HOWEVER...DUE TO TIMING UNCERTAINTIES I WILL CONTINUE WITH
SOME LOWER END CHANCES LATE WED THROUGH THURSDAY.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE THIS AFTN WITH EAST WINDS BEHIND IT. ANOTHER LAKE
BREEZE TOMORROW AFTN.
KMD/IZZI
//DISCUSSION...UPDATED 18Z...
WINDS BEHIND THE LAKE BREEZE HAVE ALL GENERALLY BEEN 6-8 KT...AND
HAVE NO REASON TO BELIEVE THAT WINDS WILL GET ANY STRONGER ONCE
THE LAKE BREEZE PUSHES INTO ORD/MDW. LESS CLOUD COVER IS EXPECTED
TOMORROW WHICH MAY ENCOURAGE A BIT STRONGER LAKE BREEZE...BUT AT
THIS TIME IT STILL LOOKS LIKE WINDS STAY BELOW 10 KT.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM-HIGH CONFIDENCE IN WIND SPEEDS BELOW 10 KT BEHIND THE
LAKE BREEZE THIS AFTERNOON
KMD/IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT THROUGH TUESDAY...VFR. LAKE BREEZES FAIRLY LIKELY EACH
AFTERNOON.
WEDNESDAY...SCHC SHRA. MVFR CIGS PSBL.
JEE
&&
.MARINE...
224 PM CDT
CONTINUED QUIET CONDITIONS WILL REMAIN OVER LAKE MICHIGAN THROUGH
THE WEEKEND WITH PERSISTENT HIGH PRESSURE OVER THE REGION.
AFTERNOON LAKE BREEZES WITH ONSHORE FLOW WILL OCCUR IN NEARSHORE
AREAS. APART FROM THESE LAKE BREEZES...THERE WILL BE VARIABLE WIND
DIRECTIONS AT TIMES. A COLD FRONT WILL INCH SOUTHWARD ACROSS THE
LAKE ON MONDAY. AS THIS WEAKENS...IT WILL ALLOW FOR SOUTHERLY
WINDS TO RETURN OVER THE LAKE BY THE MIDDLE OF NEXT WEEK.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
300 PM CDT Thu Sep 25 2014
.SHORT TERM...(Tonight)
ISSUED AT 257 PM CDT THU SEP 25 2014
A weak upper low evident on satellite in southeast Iowa, and an
associated shortwave trough rotating to the east of the low will be
responsible for a patch of mid level clouds in west central IL this
evening. Persistent radar returns are associated with these clouds,
but plenty of low level dry air is resulting in nothing more than
scattered sprinkles. These will persist in a few areas west of I-55
early this evening, but are expected to fade quickly.
The upper low will slowly drift toward the southwest, into NW
Missouri by daybreak. Many of the short range models have finally
latched on to the idea that mid level clouds will increase with the
upper low overnight in west central IL. The rest of central and
eastern IL will be mostly clear overnight with low temperatures in
the lower to middle 50s. Slightly warmer temperatures are
anticipated west of a Peoria-Springfield line where more clouds are
expected.
&&
.LONG TERM...(Friday through Thursday)
ISSUED AT 300 PM CDT THU SEP 25 2014
A large scale high pressure ridge centered over the plains states
through the Midwest and a 500 mb closed low centered just west of
Illinois will be the main weather features through the weekend.
The 500 mb low is expected to remain stalled through the weekend
providing weak lift and low level convergence. The result will be
above normal temperatures and periods of cloudiness but very
little if any chance for precipitation. The warm air mass over the
region will remain well into next week with high temperatures
reaching near 80 degrees each day. The large scale pattern is
expected to shift toward the middle of next week providing the
first opportunity for any significant chance of precipitation. The
bulk of operational and ensemble models shift the high pressure
ridge to the east coast with low pressure troughing pushing into
the Rockies or northern Plains by midweek. As a result...a plume
of moist air will be able to approach the Midwest in southerly
return flow. A chance of precipitation returns to the forecast by
Wednesday and thursday as a result...although temperatures
continue above normal with no significant cooling likely by then.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1201 PM CDT THU SEP 25 2014
Stagnent pattern over region this afternoon with weak upper wave over
Mississippi Valley becoming cutoff and embedded in strong mid-
level ridging. Just enough lift and moisture with this wave to
produce mid-level clouds with occasional CIGs mostly above 8 Kft.
A few sprinkles were noted at KBRL this morning, but associated
cloud and reflectivity band is slowly pushing east into drier air
and will likely not produce pcpn as far east as KPIA or KSPI.
NAM and HRRR move cloud band east to U.S. 51 overnight and will
reflect a high CIG at KBMI and KDEC after 03z. As low cuts off and
retrogrades southwest, lift weakens over Illinois and mid-level
clouds begin to dissipate on Friday.
Some minor concerns with potential for reduced vsbys in BR toward
sunrise, particularly at KCMI where cloudiness should be
scattered. For now will leave out, but will monitor incoming model
data closely.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...ONTON
AVIATION...BARKER/MILLER
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
113 PM CDT THU SEP 25 2014
.DISCUSSION...
913 AM CDT
FORECAST UPDATED TO HOLD ONTO MORE CLOUD COVER THROUGH TODAY AND TO
NUDGE DOWN TEMPERATURES AS A RESULT...NAMELY IN FAR NORTHERN AND
NORTHEAST IL. GOES WATER VAPOR IMAGERY SHOWS A WELL-DEFINED SHORT
WAVE CIRCULATION DROPPING SOUTHWARD ACROSS IA THIS MORNING. A POCKET
OF WARM-AIR ADVECTION ABOVE 10KFT IS SUPPORTING A BLANKET OF
MID-LEVEL CLOUDS AND EVEN SOME WIDELY PATCHY SPRINKLES. THE 12Z
DVN SOUNDING REVEALED THIS SATURATION AROUND 7KFT THICK. THAT
GREAT OF DEPTH ALONG WITH THE CONTINUED LIFT SHOULD SUPPORT THE
CLOUDS THROUGH AT LEAST EARLY AFTERNOON BEFORE SOME THINNING AS
THE SHORT WAVE DAMPENS AND LIFT WEAKENS.
TEMPERATURES IN SOME PLACES HAVE BEEN SLOW TO RISE BUT IT WONT
TAKE MUCH THINNING FOR THAT TO EASILY BE MADE UP...SO HAVE ONLY
INCHED DOWN HIGHS WHERE WE EXPECT THE CLOUDS THE LONGEST. A LAKE
BREEZE WILL DEVELOP AGAIN THIS AFTERNOON SUCH AS RECENT DAYS.
MTF
//PREV DISCUSSION...
248 AM CDT
SYNOPSIS...ANOTHER DAY WITH HIGHS IN THE MID TO UPPER 70S EXCEPT FOR
ALONG THE LAKE WHERE A LAKE BREEZE WILL KEEP TEMPS AROUND 70. THE
FORECAST LOOKS SIMILAR THROUGH THE WEEKEND...THEN COOLER EARLY NEXT
WEEK. DRY CONDITIONS CONTINUE INTO NEXT WEEK.
TODAY THROUGH FRIDAY...
AN UPPER LEVEL CLOSED LOW FORMS OVERHEAD TODAY AND RETROGRADES WEST
THROUGH THE WEEKEND. AT THE SURFACE HIGH PRESSURE CONTINUES TO RULE
WITH CONTINUED DRY CONDITIONS. SCT TO BKN CIRRUS IS EXPECTED WHICH
MAY LIMIT HIGH TEMPS. KNOCKED TEMPS DOWN BY A DEGREE OR SO...BUT
STILL THINKING WE WILL SEE MID TO UPPER 70S. A LAKE BREEZE IS
EXPECTED WHICH WILL KEEP TEMPS ALONG THE LAKE IN THE UPPER 60S TO
AROUND 70. OUTSIDE OF THE LAKE BREEZE...WINDS WILL BE WEAK AND
VARIABLE.
CIRRUS THINS OVERNIGHT AND LOWS WILL BE IN THE MID TO UPPER 50S
DOWNTOWN...AND THEN IN THE LOWER 50S OUTSIDE OF THE CITY.
FRIDAY LOOKS PRETTY SIMILAR TO TODAY WITH ANOTHER LAKE BREEZE
EXPECTED. WIND SPEEDS WILL BE A TOUCH STRONGER AND OUT OF THE SE OR
E. WITH THE UPPER LEVEL LOW SHIFTING WEST...SKIES WILL BE CLEAR AND
THEREFORE LOOKING AT SLIGHTLY WARMER TEMPS. COULD SEE 80S ALONG AND
SOUTH OF I-80.
JEE
FRIDAY NIGHT THROUGH WEDNESDAY...
BROAD MID-LVL RIDGING REMAINS IN PLACE THROUGH THE WEAKEN. GUIDANCE
CONTINUES TO INDICATE A CUTOFF MID-LVL FEATURE ACROSS THE CENTRAL
CONUS FRI/SAT...THEN WEAKENS BY SUN. ENSEMBLES CONTINUE TO SUGGEST A
TROUGH DEVELOPING BY EARLY NEXT WEEK ACROSS THE CANADIAN
MARITIME...WHICH COULD ACT AS A BLOCK TO THE RIDGING OVER THE GREAT
LAKES REGION FROM DISSOLVING TOO MUCH. NONETHELESS...THE CONTINUED
PATTERN OF DRY WITH SEASONAL TO SLIGHTLY ABOVE SEASONAL TEMPS WILL
PERSIST THROUGH AT LEAST TUE. WEAK FLOW NEAR THE SFC WILL ALSO AID
IN THE DEVELOPMENT OF FREQUENT AFTN LAKE BREEZES AND HELP TO KEEP
ADJACENT LAND SLIGHTLY COOLER. THERE IS SOME INDICATION THAT SOME
PRECIP COULD RETURN MID NEXT WEEK...BUT THIS IS CURRENTLY A VERY LOW
CONFIDENCE SETUP.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE BREEZE THIS AFTN WITH EAST WINDS BEHIND IT. ANOTHER LAKE
BREEZE TOMORROW AFTN.
KMD
//DISCUSSION...UPDATED 18Z...
WINDS BEHIND THE LAKE BREEZE HAVE ALL GENERALLY BEEN 6-8 KT...AND
HAVE NO REASON TO BELIEVE THAT WINDS WILL GET ANY STRONGER ONCE
THE LAKE BREEZE PUSHES INTO ORD/MDW. LESS CLOUD COVER IS EXPECTED
TOMORROW WHICH MAY ENCOURAGE A BIT STRONGER LAKE BREEZE...BUT AT
THIS TIME IT STILL LOOKS LIKE WINDS STAY BELOW 10 KT.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM-HIGH CONFIDENCE IN WIND SPEEDS BELOW 10 KT BEHIND THE
LAKE BREEZE THIS AFTERNOON
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT THROUGH TUESDAY...VFR. LAKE BREEZES FAIRLY LIKELY EACH
AFTERNOON.
WEDNESDAY...SCHC SHRA. MVFR CIGS PSBL.
JEE
&&
.MARINE...
248 AM CDT
DAILY LAKE BREEZES ARE EXPECTED THROUGH THE WEEKEND. FOR THE OPEN
WATERS...LIGHT AND VARIABLE FLOW IS EXPECTED TODAY AND FRIDAY WITH
WINDS BECOMING E TO SE TONIGHT AND FRIDAY NIGHT LESS THAN 10 KT.
S TO SE WINDS ARND 10 KT ESTABLISH THEMSELVES ACROSS THE LAKE
SATURDAY AND SUNDAY. A WEAK FRONT MOVES DOWN THE LAKE EARLY NEXT
WEEK WITH WINDS BECOMING E TO NE 10-15 KT EARLY NEXT WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1201 PM CDT Thu Sep 25 2014
.UPDATE...
ISSUED AT 1007 AM CDT THU SEP 25 2014
Updated the forecast to reflect the trends in satellite and radar.
The latest water vapor satellite loop shows an upper low in
northeast Iowa slowly retrograding toward south central Iowa. The
short range models handle this feature fairly well, but their
associated mid level moisture fields are not the best at depicting
the mid level clouds across much of central and eastern IL this
morning - with the exception of the new 12z NAM. Thus, increased the
cloud cover through early tonight and shaved a few degrees off
temperatures.
Also introduced scattered sprinkles into the forecast west of a
Peoria-Springfield line for this afternoon. Radar indicated a
rather persistant area of showers associated with a mid-level
shortwave trough. However, with the retrograding upper low the
eastward extent of this will be limited to mainly west central IL.
The 12z ILX sounding was also quite dry in the lower levels of the
atmosphere, so very little rain will make it to the ground, so
scattered sprinkles was mentioned instead of showers.
&&
.SHORT TERM...(Today)
ISSUED AT 340 AM CDT THU SEP 25 2014
Mid and high clouds continue to move across the western half of the
CWA early this morning. While this area of clouds moves across the
area, the mid clouds scatter out and dissipate, so clouds are a
little thinner in the east and southeast. These clouds could hinder
any warm up but still expecting high temps today to be the same as
yesterday, in the upper 70s. Light southeast winds will also
continue.
&&
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 340 AM CDT THU SEP 25 2014
Energy associated with the wave currently over the Midwest lingering
over the region and keeping an unsettled disturbance aloft just to
the west but remaining rather quiet through the end of the week.
Warm days and cool overnights continue as the max temps hover in the
upper 70s/near 80. The solution for the pattern shift at the end of
the weekend is slowly coming into focus. Models persist in keeping
the disturbance over the region into the weekend...developing more
precip as an interaction with that wave and warm and higher RH air
pushing in to the southern rim of the sfc high for the first part of
next week. ECMWF and GFS coming together with slowly with the GFS
developing more precip like the ECMWF, but ECMWF is also following
suit with the GFS for keeping the majority of the precip south of
ILX. Other than some slights and low chance pops in the southeast,
the forecast remains mainly dry until the kicker wave/trof moves
into the Plains on Thurs night. The extended starting to look a bit
messy for the end of next week with some pretty significant timing
differences. Since well out in Day 8, forecast will remain
conservative.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1201 PM CDT THU SEP 25 2014
Stagnent pattern over region this afternoon with weak upper wave over
Mississippi Valley becoming cutoff and embedded in strong mid-
level ridging. Just enough lift and moisture with this wave to
produce mid-level clouds with occasional CIGs mostly above 8 Kft.
A few sprinkles were noted at KBRL this morning, but associated
cloud and reflectivity band is slowly pushing east into drier air
and will likely not produce pcpn as far east as KPIA or KSPI.
NAM and HRRR move cloud band east to U.S. 51 overnight and will
reflect a high CIG at KBMI and KDEC after 03z. As low cuts off and
retrogrades southwest, lift weakens over Illinois and mid-level
clouds begin to dissipate on Friday.
Some minor concerns with potential for reduced vsbys in BR toward
sunrise, particularly at KCMI where cloudiness should be
scattered. For now will leave out, but will monitor incoming model
data closely.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MILLER
SHORT TERM...AUTEN
LONG TERM...HJS
AVIATION...BARKER/MILLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
228 AM MDT THU SEP 25 2014
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 221 AM MDT THU SEP 25 2014
A RIDGE WILL BE OVER THE PLAINS TODAY AND TONIGHT AND THEN SHIFT
EASTWARD THROUGH SATURDAY AS LOW PRESSURE MOVE INTO NEVADA. SURFACE
HIGH PRESSURE WILL CONTINUE OVER THE CENTRAL PLAINS TODAY AND
TONIGHT. A TROUGH WILL START DEVELOPING OVER WYOMING FRIDAY AND INTO
EASTERN COLORADO SATURDAY AND SATURDAY NIGHT.
SUBSIDENCE AND OR LACK OF ANY SIGNIFICANT FORCING WILL KEEP DRY
CONDITIONS ONGOING THROUGH SATURDAY NIGHT. THE WARM FRONT APPEARS
TO BE TOO FAR SOUTH OF THE FA TO WARRANT ANY CONCERN FOR STORM
DEVELOPMENT OVER THE SOUTHERN FA THIS AFTERNOON/EVENING. POPS WILL
BE NIL FROM TODAY THROUGH SATURDAY NIGHT.
BOUNDARY LAYER RH DOES INCREASE OVER THE EASTERN FA BUT ARE AROUND
70 PERCENT. THIS IS CONSIDERABLY UNDER THE 90 PERCENT THAT IS
MORE FAVORABLE FOR STRATUS OR FOG DEVELOPMENT. HOWEVER, WINDS WILL
BE CALM. FOR NOW WILL MONITOR ANY DEVELOPMENT PRIOR TO ISSUANCE.
MAX TEMPERATURES WILL RANGE FROM THE LOWER TO MID 80S. MIN
TEMPERATURES WILL BE IN THE MID TO UPPER 50S.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 221 AM MDT THU SEP 25 2014
PRIMARY FOCUS FOR THE EXTENDED PERIOD REMAINS AN UPPER LOW/MID-LEVEL
TROUGH MOVING THROUGH THE CENTRAL GREAT BASIN REGION...BRINGING
MOISTURE AND LARGE SCALE FORCING FOR PRECIP EARLY NEXT WEEK. NO
SIGNIFICANT CHANGES FROM PREVIOUS FORECASTS AS GUIDANCE IS SLOWLY
BECOMING MORE CONSISTENT RUN-TO-RUN AND ACROSS DIFFERENT MODELS.
OVERALL TREND HAS BEEN FOR A SLOWER AND DEEPER EVOLUTION OF THE
TROUGH...WHICH MEANS A SLIGHT DELAY ON PRECIP BUT A BETTER SHOT AT
FORCING/MOISTURE.
SUN/MON...HIGHS IN THE UPPER 70S TO LOW 80S. RAINFALL CHANCES BEST
MONDAY INTO MONDAY NIGHT AS THE BEST FORCING DEVELOPS ACROSS THE
CENTRAL HIGH PLAINS. LATEST ECMWF IS PARTICULARLY WET...PAINTING A
WIDESPREAD HALF-INCH PLUS QPF ACROSS EASTERN COLORADO...NORTHWEST
KANSAS...AND ALMOST THE ENTIRE WESTERN HALF OF NEBRASKA. AS IN
PREVIOUS RUNS IT STILL APPEARS THE BEST INGREDIENTS FOR HEAVY RAIN
WILL DEVELOP NORTH OF THE CWA IN WESTERN NEBRASKA...BUT GIVEN THE
SLOWER/DEEPER TREND WOULD NOT BE SURPRISED IF THIS MAXIMA DRIFTS
SOUTH IN FUTURE RUNS. PWATS ARE IN THE 1.0 TO 1.3 INCH RANGE...NOT
PARTICULARLY IMPRESSIVE BUT ABOVE NORMAL FOR THIS TIME OF THE YEAR
NONETHELESS. INSTABILITY APPEARS A BIT MORE IMPRESSIVE THAN PREVIOUS
MODEL RUNS...UP TO 1000 J/KG MUCAPE LATE MONDAY. 0-6KM SHEAR IN THE
20 TO 30 KT RANGE INDICATES THUNDERSTORMS WOULD BE MAINLY ORGANIZED
MULTICELLULAR...AND WITH A 50KT LLJ DEVELOPING EARLY MONDAY EVENING
ORGANIZED CONVECTION SHOULD BE ABLE TO SUSTAIN INTO THE OVERNIGHT
HOURS WITH STORM MOTIONS NORTH-NORTHEAST AT AROUND 15 KTS.
TUES...DRY WITH HIGHS REACHING THE MID 70S. AS MID-LEVEL TROUGH AXIS
SWINGS EAST THE BEST CHANCE FOR PRECIP WILL BE ALONG CENTRAL AND
EASTERN NEBRASKA/KANSAS...REMAINING OUTSIDE THE CWA.
WED/THURS...WITH A LONGWAVE TROUGH PARKED ACROSS THE WESTERN THIRD
OF THE CONUS THE REGION WILL BE UNDER SOUTHWESTERLY FLOW AT
MID/UPPER LEVELS. AS THE MAIN UPPER LOW CIRCULATION THAT BROUGHT
RAIN MONDAY/MONDAY NIGHT MOVES NORTH ANOTHER UPPER LOW/SHORTWAVE
TROUGH DIPS OUT OF THE PACIFIC NORTHWEST AND SWINGS ACROSS THE
CENTRAL ROCKIES LATE WEDNESDAY INTO EARLY THURSDAY. THIS WILL BRING
ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE REGION. HIGHS A
BIT COOLER AS LOW-LEVEL WINDS TURN OUT OF THE NORTH BEHIND A WEEK
COLD FRONT...IN THE LOW 70S TO PERHAPS AS COOL AS THE MID 60S ON
THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1050 PM MDT WED SEP 24 2014
KGLD...VFR THROUGH THE PERIOD UNDER A GENERALLY CLEAR SKY. MAY SEE
SOME HIGH BASED FAIR WEATHER CUMULUS CLOUDS IN THE 19Z-23Z TIME
FRAME. WINDS AT TAF ISSUANCE FROM THE SOUTH NEAR 10KTS BECOMING
SOUTHWEST AROUND 06KTS BY 09Z THEN SOUTHEAST AT 05KTS BY 14Z. FROM
18Z THROUGH THE REST OF THE TAF PERIOD SOUTHEAST WINDS AROUND
11KTS EXPECTED...THERE WILL BE A PERIOD FROM 19Z-23Z WHERE SOME
GUSTS NEAR 18KTS POSSIBLE.
KMCK...VFR EXPECTED TONIGHT THROUGH 10Z AND AFTER 16Z. IN THE
11Z-15Z TIME FRAME SOME INCREASE IN LOW LEVEL MOISTURE REACHES
THE TERMINAL FROM THE EAST PRODUCING SOME MVFR VISIBILITIES. WILL
HAVE TO WATCH FOR SOME IFR VIS IF THE LATEST HRRR MODEL RUN
VERIFIES. WINDS AT TAF ISSUANCE FROM THE SOUTHEAST AROUND 07KTS
BECOMING VRB03KTS OR LESS IN THE 08Z-17Z TIME FRAME. FROM 18Z
THROUGH THE REST OF THE TAF PERIOD WINDS FROM THE SOUTHEAST NEAR
10KTS...SOME GUSTS TO 16KTS POSSIBLE IN THE 19Z-23Z TIME FRAME.
SIMILAR TO KGLD MAY SEE SOME HIGH BASED FAIR WEATHER CUMULUS
CLOUDS IN THE 19Z-23Z TIME FRAME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...JJM
AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1050 PM MDT WED SEP 24 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 220 PM MDT WED SEP 24 2014
LATEST SATELLITE AND UPPER AIR ANALYSIS INDICATE MOSTLY CLEAR SKIES
OVER THE HIGH PLAINS BEHIND THE UPPER LEVEL SHORT WAVE TROUGH THAT
MOVED THROUGH YESTERDAY AFTERNOON AND AHEAD OF THE UPPER LEVEL RIDGE
TO THE WEST. CUMULUS CLOUDS ARE DEVELOPING OVER SOUTHEAST COLORADO
AND SOUTHWEST KANSAS WHERE WEAK ISENTROPIC LIFT...CONVERGENCE WITH
THE 850MB JET AND SURFACE TROUGH...AND ON THE NORTHERN EDGE OF THE
HIGHER 0-1KM MIXED LAYER CAPE.
FOR THE REST OF THE AFTERNOON EXPECT THE STORMS DEVELOPING OVER
SOUTHWEST TO INCREASE IN COVERAGE AS THE MEAN WIND DIRECTS THEM
SOUTH. DESPITE CUMULUS CLOUDS DEVELOPING OVER EAST CENTRAL
COLORADO...DO NOT ANTICIPATE THEM TO BECOME STORMS DUE TO 0-1KM
MIXED LAYER CAPE LESS THAN 500J/KG. FURTHER EAST NEAR GOVE AND HILL
CITY MIXED LAYER CAPE INCREASES TO AROUND 700J/KG BUT THE SURFACE
TROUGH WILL BE SOUTHEAST OF THE AREA. THEREFORE ANTICIPATE STORMS
TO REMAIN SOUTH OF THE AREA THROUGH THE REST OF THE AFTERNOON.
TONIGHT LIGHT AND VARIABLE WINDS WITH CLEAR SKIES ARE EXPECTED. THE
SURFACE TROUGH MOVES BACK NORTH BUT THE ENVIRONMENT WILL BE TOO DRY
AND STABLE FOR STORMS TO DEVELOP. DEW POINTS WILL INCREASE OVER THE
EAST 1/3 OF THE AREA AS THE SURFACE TROUGH MOVES BACK NORTHWEST
ACROSS THE AREA. THIS WILL ALLOW FOR FOG TO DEVELOP EAST OF HWY 25
AROUND SUNRISE.
THURSDAY MORNING THE FOG SHOULD BURN OFF A COUPLE HOURS AFTER
SUNRISE. DURING THE AFTERNOON A WARM FRONT WILL MOVE INTO THE FAR
SOUTHERN PART OF THE AREA. BEHIND THE FRONT INSTABILITY WILL
INCREASE. THE MAJORITY OF THE MODELS KEEP THE INSTABILITY SOUTH
OF THE AREA SO WILL KEEP THE FORECAST DRY FOR THE AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 220 PM MDT WED SEP 24 2014
THURSDAY NIGHT-SATURDAY...UPPER LEVEL RIDGE WILL DOMINATE MUCH OF
THE PLAINS THROUGH THE PERIOD AS STRONG TROUGH DIGS INTO THE FOUR
CORNERS AREA. WHILE THERE IS SOME DISAGREEMENT IN THE NEAR TERM
MODELS ABOUT DEVELOPING A WARM FRONT THURSDAY AFTERNOON WHICH COULD
PROVIDE A FOCUS FOR DEEP MOIST CONVECTION...SREF DATA ALONG WITH
OTHER OPERATIONAL MODELS SUGGEST MOST LIKELY SCENARIO WOULD BE FOR
ANY POTENTIAL PRECIPITATION TO REMAIN SOUTH OF THE AREA ACROSS SOUTH
CENTRAL KANSAS. OTHERWISE...DRY WEATHER IS EXPECTED THROUGH THE REST
OF THE PERIOD.
ALTHOUGH H5 TROUGH WILL REMAIN TO THE WEST OF THE AREA...WILL SEE AN
INCREASING INFLUENCE ON THE SFC PATTERN ACROSS THE CWA. SOUTHERLY
WINDS WILL GRADUALLY INCREASE ON FRIDAY...AND WILL BE EVEN STRONGER
ON SATURDAY. CURRENTLY LOOKS LIKE IT WILL NOT BE WARNING
SPEEDS...BUT WOULD NOT BE SURPRISED TO SEE SUSTAINED 30 GUST 45 MPH
TYPE WINDS IN THE AFTERNOON.
IN THE EXTENDED (SATURDAY NIGHT-WEDNESDAY)...STRONG H5 TROUGH
MENTIONED PREVIOUSLY WILL BE MAJOR FORECAST CONCERN THROUGH THE
EXTENDED PERIOD AS IT POTENTIALLY WILL HAVE A LARGE IMPACT ON
SENSIBLE WEATHER ACROSS THE CWA. GFS AND ECMWF HAVE COME INTO A
LITTLE BETTER AGREEMENT WITH RESPECT TO MAGNITUDE OF THE TROUGH
ALTHOUGH SOME SIG DIFFERENCES REMAIN. GEFS H5 MEAN/STD DEV PLOTS
SUGGEST MAIN ISSUE IN THE ENSEMBLES IS THE SPEED OF THE SYSTEM AS
OPPOSED TO STRENGTH...AND THEREFORE THINK A PERIOD OF HIGHER POPS IS
WARRANTED DURING THE START OF THE WEEK. THINK MOISTURE RETURN MAY BE
SOMEWHAT LIMITED WHICH COULD IMPACT STRENGTH OF RESPONSE TO
TROUGH...BUT OVERALL THINK SOME PRECIPITATION LOOKS LIKELY.
OTHERWISE...THINK MEAN VALUES LOOK REPRESENTATIVE FOR THE TIME BEING
AND DID NOT MAKE ANY LARGE CHANGES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1050 PM MDT WED SEP 24 2014
KGLD...VFR THROUGH THE PERIOD UNDER A GENERALLY CLEAR SKY. MAY SEE
SOME HIGH BASED FAIR WEATHER CUMULUS CLOUDS IN THE 19Z-23Z TIME
FRAME. WINDS AT TAF ISSUANCE FROM THE SOUTH NEAR 10KTS BECOMING
SOUTHWEST AROUND 06KTS BY 09Z THEN SOUTHEAST AT 05KTS BY 14Z. FROM
18Z THROUGH THE REST OF THE TAF PERIOD SOUTHEAST WINDS AROUND
11KTS EXPECTED...THERE WILL BE A PERIOD FROM 19Z-23Z WHERE SOME
GUSTS NEAR 18KTS POSSIBLE.
KMCK...VFR EXPECTED TONIGHT THROUGH 10Z AND AFTER 16Z. IN THE
11Z-15Z TIME FRAME SOME INCREASE IN LOW LEVEL MOISTURE REACHES
THE TERMINAL FROM THE EAST PRODUCING SOME MVFR VISIBILITIES. WILL
HAVE TO WATCH FOR SOME IFR VIS IF THE LATEST HRRR MODEL RUN
VERIFIES. WINDS AT TAF ISSUANCE FROM THE SOUTHEAST AROUND 07KTS
BECOMING VRB03KTS OR LESS IN THE 08Z-17Z TIME FRAME. FROM 18Z
THROUGH THE REST OF THE TAF PERIOD WINDS FROM THE SOUTHEAST NEAR
10KTS...SOME GUSTS TO 16KTS POSSIBLE IN THE 19Z-23Z TIME FRAME.
SIMILAR TO KGLD MAY SEE SOME HIGH BASED FAIR WEATHER CUMULUS
CLOUDS IN THE 19Z-23Z TIME FRAME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JTL
LONG TERM...JRM
AVIATION...99
AREA FORECAST DISCUSSION
NWS GRAY ME
1252 PM EDT THU SEP 25 2014
.SYNOPSIS...
HIGH PRESSURE WILL HOLD OFF THE EAST COAST THROUGH THURSDAY AS
LOW PRESSURE APPROACHES FROM THE SOUTH. LOW PRESSURE SOUTH OF NEW
ENGLAND TONIGHT WILL GRADUALLY DRIFT OFF TO THE EAST THROUGH
FRIDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST FRIDAY NIGHT AND
WILL HOLD OVER THE REGION SATURDAY THROUGH SUNDAY. A COLD FRONT
WILL APPROACH FROM THE NORTH SUNDAY NIGHT AND WILL DROP SOUTH
THROUGH THE REGION ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1245 PM UPDATE...MADE SOME CHANGES TO THE CLOUD COVER AND POP. IT
APPEARS THAT ALL PRECIP IS GOING TO STAY TO THE SOUTH OF THE CWA
WITH DRY AIR IN PLACE HERE IN THE LOW-MID LEVELS. I STILL KEPT A
SLIGHT CHANCE IN THERE FOR TONIGHT ALTHOUGH IF ANY RETURNS DO MAKE
IT THAT FAR NORTH IT WILL MOST LIKELY JUST BE VIRGA. MAIN IMPACT
FOR THIS STORM FOR US IS THE MID LEVEL CLOUDS AND THE
CIRROSTRATUS.
1000 AM UPDATE...JUST MADE SOME MINOR CHANGES BASED ON CURRENT OBS
AND TRENDS. MID-HIGH LEVEL CLOUDS WILL CONTINUE TO INCREASE ACROSS
THE SOUTHERN HALF OF THE CWA AS LOW PRESSURE OFF THE MID ATLANTIC
COAST PUSHES NORTHWARD.
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS THIS MORNING. HAVE
INCREASED CLOUD GRIDS AND MAKE MINOR ADJUSTMENTS TO DEW POINTS.
OTHERWISE...DRY CONDITIONS CONTINUE ACROSS THE REGION WITH ANY
PRECIP THIS EVENING REMAINING TO OUR SOUTH PER LATEST
TRENDS...OBSERVATIONS AND NUMERICAL GUIDANCE.
PREV DISC...
MESOSCALE MODELS REMAIN IN RELATIVELY GOOD AGREEMENT
EARLY THIS MORNING WITH THE TRACK AND MOISTURE ASSOCIATED WITH THE
COASTAL LOW ALONG THE MID ATLANTIC COASTLINE. WILL KEEP VERY LOW
POPS ALONG OUR SOUTHERNMOST BORDER IN GOOD AGREEMENT WITH ADJACENT
OFFICES. MOISTURE FROM SURFACE LOW PRESSURE WILL CROSS OUR REGION
TODAY AND TONIGHT IN THE FORM OF MAINLY AC AND CS. HAVING SAID
THAT...VERY DRY AIR CONTINUES TO DOMINATE OUR REGION AS NOTED BY
THE 00Z GYX SOUNDING AND THE EXTREMELY LOW DEW POINTS ON THE
SUMMIT OF MOUNT WASHINGTON.
EXPECT INLAND VALLEYS TO CONTINUE TO HAVE FOG EARLY THIS
MORNING...BEFORE THE WEAKENING SEPTEMBER SUN MIXES THINGS OUT.
&&
.SHORT TERM /FRIDAY/...
LATEST HRRR RUN BRINGS MOISTURE IN THE FORM OF VERY LIGHT RAIN
INTO NORTHERN MASSACHUSETTS...JUST SOUTH OF OUR BORDER THIS
EVENING...BEFORE BEGINNING TO SETTLE SOUTHWARD ONE AGAIN LATER
TONIGHT AND FRIDAY. WILL CONTINUE TO KEEP VERY LOW POPS OVER
SOUTHERNMOST AREAS NEAR THE MASS BORDER THIS PACKAGE ONCE AGAIN.
ON FRIDAY...EXPECT A GRADUAL MODERATING TREND IN TEMPERATURES TO
BEGIN. WIDESPREAD 70S WILL BE THE RULE...EVEN ALONG THE COAST AS
HIGH PRESSURE AND MORE DRY AIR BEGINS TO ENTER THE REGION FROM THE
GREAT LAKES AREA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
SURFACE HIGH PRESSURE MOVES SLOWLY EAST ACROSS THE NORTHEAST
SATURDAY AND SUNDAY. UPPER RIDGE ALSO SLIDES EAST WITH WARMING
TEMPERATURES EXPECTED BENEATH THE RIDGE. EXPECT DAILY HIGH AND LOW
TEMPERATURES TO BE RISING THROUGH SUNDAY... WITH HIGHS POSSIBLY
REACHING 80 DEGREES IN A FEW PLACES.
COLD FRONT DROPS SOUTH THROUGH THE REGION ON MONDAY WITH COOLER
TEMPERATURES BEHIND IT. THERE WILL BE AN OUTSIDE CHANCE OF A
SHOWER ALONG THE FRONT BUT OVERALL THE MOISTURE CONNECTION AHEAD
OF THE FRONT IS LIMITED SO DO NOT EXPECT WIDESPREAD SHOWERS OR
HEAVY RAIN. EASTERLY FLOW ON TUESDAY KEEPS TEMPERATURES EVEN
COOLER... BUT PRECIPITATION ASSOCIATED WITH WEAK LOW PRESSURE WELL
TO THE SOUTH SHOULD STAY SOUTH OF MAINE AND NEW HAMPSHIRE. ECMWF
SEEMS TO BE DOING A BETTER JOB DURING THIS TIME PERIOD THAN THE
GFS. SURFACE HIGH PRESSURE BUILDS SOUTH OUT OF EASTERN CANADA AND
INTO THE CANADIAN MARITIMES... KEEPING SEASONABLY COOL CONDITIONS
OVER NORTHERN NEW ENGLAND FOR MUCH OF THE WEEK.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SHORT TERM...VFR CONDITIONS WILL PERSIST EXCEPT FOR SOME VALLEY
FOG WITH A PERIOD OF LIFR CONDITIONS DURING THE EARLY MORNING
HOURS THIS MORNING AND EARLY FRIDAY MORNING.
LONG TERM...WILL HAVE NIGHTLY FOG AT LEBANON AND WHITEFIELD (AND
OCCASIONALLY CONCORD) BUT OTHERWISE EXPECT VFR CONDITIONS THROUGH
MONDAY.
&&
.MARINE...
SHORT TERM...NO FLAGS WITH LOW PRESSURE AND STRONGEST GRADIENT
REMAINING WELL SOUTH OF OUR COASTAL WATERS.
LONG TERM...HIGH PRESSURE AND WEAK PRESSURE GRADIENT KEEP WINDS
LIGHT THROUGH EARLY NEXT WEEK.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
KISTNER
AREA FORECAST DISCUSSION
NWS GRAY ME
1003 AM EDT THU SEP 25 2014
.SYNOPSIS...
HIGH PRESSURE WILL HOLD OFF THE EAST COAST THROUGH THURSDAY AS
LOW PRESSURE APPROACHES FROM THE SOUTH. LOW PRESSURE SOUTH OF NEW
ENGLAND TONIGHT WILL GRADUALLY DRIFT OFF TO THE EAST THROUGH
FRIDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST FRIDAY NIGHT AND
WILL HOLD OVER THE REGION SATURDAY THROUGH SUNDAY. A COLD FRONT
WILL APPROACH FROM THE NORTH SUNDAY NIGHT AND WILL DROP SOUTH
THROUGH THE REGION ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 AM UPDATE...JUST MADE SOME MINOR CHANGES BASED ON CURRENT OBS
AND TRENDS. MID-HIGH LEVEL CLOUDS WILL CONTINUE TO INCREASE ACROSS
THE SOUTHERN HALF OF THE CWA AS LOW PRESSURE OFF THE MID ATLANTIC
COAST PUSHES NORTHWARD.
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS THIS MORNING. HAVE
INCREASED CLOUD GRIDS AND MAKE MINOR ADJUSTMENTS TO DEW POINTS.
OTHERWISE...DRY CONDITIONS CONTINUE ACROSS THE REGION WITH ANY
PRECIP THIS EVENING REMAINING TO OUR SOUTH PER LATEST
TRENDS...OBSERVATIONS AND NUMERICAL GUIDANCE.
PREV DISC...
MESOSCALE MODELS REMAIN IN RELATIVELY GOOD AGREEMENT
EARLY THIS MORNING WITH THE TRACK AND MOISTURE ASSOCIATED WITH THE
COASTAL LOW ALONG THE MID ATLANTIC COASTLINE. WILL KEEP VERY LOW
POPS ALONG OUR SOUTHERNMOST BORDER IN GOOD AGREEMENT WITH ADJACENT
OFFICES. MOISTURE FROM SURFACE LOW PRESSURE WILL CROSS OUR REGION
TODAY AND TONIGHT IN THE FORM OF MAINLY AC AND CS. HAVING SAID
THAT...VERY DRY AIR CONTINUES TO DOMINATE OUR REGION AS NOTED BY
THE 00Z GYX SOUNDING AND THE EXTREMELY LOW DEW POINTS ON THE
SUMMIT OF MOUNT WASHINGTON.
EXPECT INLAND VALLEYS TO CONTINUE TO HAVE FOG EARLY THIS
MORNING...BEFORE THE WEAKENING SEPTEMBER SUN MIXES THINGS OUT.
&&
.SHORT TERM /FRIDAY/...
LATEST HRRR RUN BRINGS MOISTURE IN THE FORM OF VERY LIGHT RAIN
INTO NORTHERN MASSACHUSETTS...JUST SOUTH OF OUR BORDER THIS
EVENING...BEFORE BEGINNING TO SETTLE SOUTHWARD ONE AGAIN LATER
TONIGHT AND FRIDAY. WILL CONTINUE TO KEEP VERY LOW POPS OVER
SOUTHERNMOST AREAS NEAR THE MASS BORDER THIS PACKAGE ONCE AGAIN.
ON FRIDAY...EXPECT A GRADUAL MODERATING TREND IN TEMPERATURES TO
BEGIN. WIDESPREAD 70S WILL BE THE RULE...EVEN ALONG THE COAST AS
HIGH PRESSURE AND MORE DRY AIR BEGINS TO ENTER THE REGION FROM THE
GREAT LAKES AREA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
SURFACE HIGH PRESSURE MOVES SLOWLY EAST ACROSS THE NORTHEAST
SATURDAY AND SUNDAY. UPPER RIDGE ALSO SLIDES EAST WITH WARMING
TEMPERATURES EXPECTED BENEATH THE RIDGE. EXPECT DAILY HIGH AND LOW
TEMPERATURES TO BE RISING THROUGH SUNDAY... WITH HIGHS POSSIBLY
REACHING 80 DEGREES IN A FEW PLACES.
COLD FRONT DROPS SOUTH THROUGH THE REGION ON MONDAY WITH COOLER
TEMPERATURES BEHIND IT. THERE WILL BE AN OUTSIDE CHANCE OF A
SHOWER ALONG THE FRONT BUT OVERALL THE MOISTURE CONNECTION AHEAD
OF THE FRONT IS LIMITED SO DO NOT EXPECT WIDESPREAD SHOWERS OR
HEAVY RAIN. EASTERLY FLOW ON TUESDAY KEEPS TEMPERATURES EVEN
COOLER... BUT PRECIPITATION ASSOCIATED WITH WEAK LOW PRESSURE WELL
TO THE SOUTH SHOULD STAY SOUTH OF MAINE AND NEW HAMPSHIRE. ECMWF
SEEMS TO BE DOING A BETTER JOB DURING THIS TIME PERIOD THAN THE
GFS. SURFACE HIGH PRESSURE BUILDS SOUTH OUT OF EASTERN CANADA AND
INTO THE CANADIAN MARITIMES... KEEPING SEASONABLY COOL CONDITIONS
OVER NORTHERN NEW ENGLAND FOR MUCH OF THE WEEK.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
SHORT TERM...VFR CONDITIONS WILL PERSIST EXCEPT FOR SOME VALLEY
FOG WITH A PERIOD OF LIFR CONDITIONS DURING THE EARLY MORNING
HOURS THIS MORNING AND EARLY FRIDAY MORNING.
LONG TERM...WILL HAVE NIGHTLY FOG AT LEBANON AND WHITEFIELD (AND
OCCASIONALLY CONCORD) BUT OTHERWISE EXPECT VFR CONDITIONS THROUGH
MONDAY.
&&
.MARINE...
SHORT TERM...NO FLAGS WITH LOW PRESSURE AND STRONGEST GRADIENT
REMAINING WELL SOUTH OF OUR COASTAL WATERS.
LONG TERM...HIGH PRESSURE AND WEAK PRESSURE GRADIENT KEEP WINDS
LIGHT THROUGH EARLY NEXT WEEK.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
KISTNER
AREA FORECAST DISCUSSION
NWS GRAY ME
645 AM EDT THU SEP 25 2014
.SYNOPSIS...
HIGH PRESSURE WILL HOLD OFF THE EAST COAST THROUGH THURSDAY AS
LOW PRESSURE APPROACHES FROM THE SOUTH. LOW PRESSURE SOUTH OF NEW
ENGLAND TONIGHT WILL GRADUALLY DRIFT OFF TO THE EAST THROUGH
FRIDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST FRIDAY NIGHT AND
WILL HOLD OVER THE REGION SATURDAY THROUGH SUNDAY. A COLD FRONT
WILL APPROACH FROM THE NORTH SUNDAY NIGHT AND WILL DROP SOUTH
THROUGH THE REGION ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS THIS MORNING. HAVE
INCREASED CLOUD GRIDS AND MAKE MINOR ADJUSTMENTS TO DEW POINTS.
OTHERWISE...DRY CONDITIONS CONTINUE ACROSS THE REGION WITH ANY
PRECIP THIS EVENING REMAINING TO OUR SOUTH PER LATEST
TRENDS...OBSERVATIONS AND NUMERICAL GUIDANCE.
PREV DISC...
MESOSCALE MODELS REMAIN IN RELATIVELY GOOD AGREEMENT
EARLY THIS MORNING WITH THE TRACK AND MOISTURE ASSOCIATED WITH THE
COASTAL LOW ALONG THE MID ATLANTIC COASTLINE. WILL KEEP VERY LOW
POPS ALONG OUR SOUTHERNMOST BORDER IN GOOD AGREEMENT WITH ADJACENT
OFFICES. MOISTURE FROM SURFACE LOW PRESSURE WILL CROSS OUR REGION
TODAY AND TONIGHT IN THE FORM OF MAINLY AC AND CS. HAVING SAID
THAT...VERY DRY AIR CONTINUES TO DOMINATE OUR REGION AS NOTED BY
THE 00Z GYX SOUNDING AND THE EXTREMELY LOW DEW POINTS ON THE
SUMMIT OF MOUNT WASHINGTON.
EXPECT INLAND VALLEYS TO CONTINUE TO HAVE FOG EARLY THIS
MORNING...BEFORE THE WEAKENING SEPTEMBER SUN MIXES THINGS OUT.
&&
.SHORT TERM /FRIDAY/...
LATEST HRRR RUN BRINGS MOISTURE IN THE FORM OF VERY LIGHT RAIN
INTO NORTHERN MASSACHUSETTS...JUST SOUTH OF OUR BORDER THIS
EVENING...BEFORE BEGINNING TO SETTLE SOUTHWARD ONE AGAIN LATER
TONIGHT AND FRIDAY. WILL CONTINUE TO KEEP VERY LOW POPS OVER
SOUTHERNMOST AREAS NEAR THE MASS BORDER THIS PACKAGE ONCE AGAIN.
ON FRIDAY...EXPECT A GRADUAL MODERATING TREND IN TEMPERATURES TO
BEGIN. WIDESPREAD 70S WILL BE THE RULE...EVEN ALONG THE COAST AS
HIGH PRESSURE AND MORE DRY AIR BEGINS TO ENTER THE REGION FROM THE
GREAT LAKES AREA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
SURFACE HIGH PRESSURE MOVES SLOWLY EAST ACROSS THE NORTHEAST
SATURDAY AND SUNDAY. UPPER RIDGE ALSO SLIDES EAST WITH WARMING
TEMPERATURES EXPECTED BENEATH THE RIDGE. EXPECT DAILY HIGH AND LOW
TEMPERATURES TO BE RISING THROUGH SUNDAY... WITH HIGHS POSSIBLY
REACHING 80 DEGREES IN A FEW PLACES.
COLD FRONT DROPS SOUTH THROUGH THE REGION ON MONDAY WITH COOLER
TEMPERATURES BEHIND IT. THERE WILL BE AN OUTSIDE CHANCE OF A
SHOWER ALONG THE FRONT BUT OVERALL THE MOISTURE CONNECTION AHEAD
OF THE FRONT IS LIMITED SO DO NOT EXPECT WIDESPREAD SHOWERS OR
HEAVY RAIN. EASTERLY FLOW ON TUESDAY KEEPS TEMPERATURES EVEN
COOLER... BUT PRECIPITATION ASSOCIATED WITH WEAK LOW PRESSURE WELL
TO THE SOUTH SHOULD STAY SOUTH OF MAINE AND NEW HAMPSHIRE. ECMWF
SEEMS TO BE DOING A BETTER JOB DURING THIS TIME PERIOD THAN THE
GFS. SURFACE HIGH PRESSURE BUILDS SOUTH OUT OF EASTERN CANADA AND
INTO THE CANADIAN MARITIMES... KEEPING SEASONABLY COOL CONDITIONS
OVER NORTHERN NEW ENGLAND FOR MUCH OF THE WEEK.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
SHORT TERM...VFR CONDITIONS WILL PERSIST EXCEPT FOR SOME VALLEY
FOG WITH A PERIOD OF LIFR CONDITIONS DURING THE EARLY MORNING
HOURS THIS MORNING AND EARLY FRIDAY MORNING.
LONG TERM...WILL HAVE NIGHTLY FOG AT LEBANON AND WHITEFIELD (AND
OCCASIONALLY CONCORD) BUT OTHERWISE EXPECT VFR CONDITIONS THROUGH
MONDAY.
&&
.MARINE...
SHORT TERM...NO FLAGS WITH LOW PRESSURE AND STRONGEST GRADIENT
REMAINING WELL SOUTH OF OUR COASTAL WATERS.
LONG TERM...HIGH PRESSURE AND WEAK PRESSURE GRADIENT KEEP WINDS
LIGHT THROUGH EARLY NEXT WEEK.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
347 AM EDT THU SEP 25 2014
.SYNOPSIS...
HIGH PRESSURE WILL HOLD OFF THE EAST COAST THROUGH THURSDAY AS
LOW PRESSURE APPROACHES FROM THE SOUTH. LOW PRESSURE SOUTH OF NEW
ENGLAND TONIGHT WILL GRADUALLY DRIFT OFF TO THE EAST THROUGH
FRIDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST FRIDAY NIGHT AND
WILL HOLD OVER THE REGION SATURDAY THROUGH SUNDAY. A COLD FRONT
WILL APPROACH FROM THE NORTH SUNDAY NIGHT AND WILL DROP SOUTH
THROUGH THE REGION ON MONDAY.
&&
.NEAR TERM /TODAY/...
MESOSCALE MODELS IN RELATIVELY GOOD AGREEMENT EARLY THIS MORNING
WITH THE TRACK AND MOISTURE ASSOCIATED WITH THE COASTAL LOW ALONG
THE MID ATLANTIC COASTLINE. WILL KEEP VERY LOW POPS ALONG OUR
SOUTHERNMOST BORDER IN GOOD AGREEMENT WITH ADJACENT OFFICES.
MOISTURE FROM SURFACE LOW PRESSURE WILL CROSS OUR REGION TODAY AND
TONIGHT IN THE FORM OF MAINLY AC AND CS. HAVING SAID THAT...VERY
DRY AIR CONTINUES TO DOMINATE OUR REGION AS NOTED BY THE 00Z GYX
SOUNDING AND THE EXTREMELY LOW DEW POINTS ON THE SUMMIT OF MOUNT
WASHINGTON.
EXPECT INLAND VALLEYS TO CONTINUE TO HAVE FOG EARLY THIS
MORNING...BEFORE THE WEAKENING SEPTEMBER SUN MIXES THINGS OUT.
&&
.SHORT TERM /TONIGHT AND FRIDAY/...
LATEST HRRR RUN BRINGS MOISTURE IN THE FORM OF VERY LIGHT RAIN
INTO NORTHERN MASSACHUSETTS...JUST SOUTH OF OUR BORDER THIS
EVENING...BEFORE BEGINNING TO SETTLE SOUTHWARD ONE AGAIN LATER
TONIGHT AND FRIDAY. WILL CONTINUE TO KEEP VERY LOW POPS OVER
SOUTHERNMOST AREAS NEAR THE MASS BORDER THIS PACKAGE ONCE AGAIN.
ON FRIDAY...EXPECT A GRADUAL MODERATING TREND IN TEMPERATURES TO
BEGIN. WIDESPREAD 70S WILL BE THE RULE...EVEN ALONG THE COAST AS
HIGH PRESSURE AND MORE DRY AIR BEGINS TO ENTER THE REGION FROM THE
GREAT LAKES AREA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
SURFACE HIGH PRESSURE MOVES SLOWLY EAST ACROSS THE NORTHEAST
SATURDAY AND SUNDAY. UPPER RIDGE ALSO SLIDES EAST WITH WARMING
TEMPERATURES EXPECTED BENEATH THE RIDGE. EXPECT DAILY HIGH AND LOW
TEMPERATURES TO BE RISING THROUGH SUNDAY... WITH HIGHS POSSIBLY
REACHING 80 DEGREES IN A FEW PLACES.
COLD FRONT DROPS SOUTH THROUGH THE REGION ON MONDAY WITH COOLER
TEMPERATURES BEHIND IT. THERE WILL BE AN OUTSIDE CHANCE OF A
SHOWER ALONG THE FRONT BUT OVERALL THE MOISTURE CONNECTION AHEAD
OF THE FRONT IS LIMITED SO DO NOT EXPECT WIDESPREAD SHOWERS OR
HEAVY RAIN. EASTERLY FLOW ON TUESDAY KEEPS TEMPERATURES EVEN
COOLER... BUT PRECIPITATION ASSOCIATED WITH WEAK LOW PRESSURE WELL
TO THE SOUTH SHOULD STAY SOUTH OF MAINE AND NEW HAMPSHIRE. ECMWF
SEEMS TO BE DOING A BETTER JOB DURING THIS TIME PERIOD THAN THE
GFS. SURFACE HIGH PRESSURE BUILDS SOUTH OUT OF EASTERN CANADA AND
INTO THE CANADIAN MARITIMES... KEEPING SEASONABLY COOL CONDITIONS
OVER NORTHERN NEW ENGLAND FOR MUCH OF THE WEEK.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
SHORT TERM...VFR CONDITIONS WILL PERSIST EXCEPT FOR SOME VALLEY
FOG WITH A PERIOD OF LIFR CONDITIONS DURING THE EARLY MORNING
HOURS THIS MORNING AND EARLY FRIDAY MORNING.
LONG TERM...WILL HAVE NIGHTLY FOG AT LEBANON AND WHITEFIELD (AND
OCCASIONALLY CONCORD) BUT OTHERWISE EXPECT VFR CONDITIONS THROUGH
MONDAY.
&&
.MARINE...
SHORT TERM...NO FLAGS WITH LOW PRESSURE AND STRONGEST GRADIENT
REMAINING WELL SOUTH OF OUR COASTAL WATERS.
LONG TERM...HIGH PRESSURE AND WEAK PRESSURE GRADIENT KEEP WINDS
LIGHT THROUGH EARLY NEXT WEEK.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
721 PM EDT FRI SEP 26 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 356 PM EDT FRI SEP 26 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH NEAR
THE WEST COAST AND A PROMINENT RIDGE ACROSS THE PLAINS INTO NRN
ONTARIO. AT THE SFC...WEAK SRLY FLOW WAS OBSERVED THROUGH WI AND
UPPER MI BETWEEN HIGH PRES OVER LAKE HURON AND A TROUGH THROUGH THE
WRN PLAINS. VIS LOOP INDICATED SCT CU UPSTREAM OVER THE UPPER MS
VALLEY AS LOW LEVEL MOISTURE INCREASES. OTHERWISE...COMPLETELY CLEAR
SKIES PREVAILED ACROSS UPPER MICHIGAN. DEWPOINTS WERE GENERALLY IN
THE LOWER 50S...WITH SOME HIGHER VALUES IN THE MID 50S OVER THE EAST
DOWNWIND OF LAKE MICHIGAN.
TONIGHT...WITH THE UPPER AND SFC RIDGE NEARLY STATIONARY OVER THE
AREA...EXPECT FOG TO REDEVELOP IN AREAS SIMILAR TO THU NIGHT...WITH
THE LOWEST VISIBILITIES OVER THE CNTRAL AND EAST AND ESPECIALLY
NEAR LAKE MICHIGAN.
SAT...A MID LEVEL TROUGH AND ASSOCIATED SFC LOW WILL MOVE THROUGH
FAR NRN ONTARIO TO SRN HUDSON BAY DRAGGING A COLD FRONT TO NEAR
CYPL. SRLY FLOW AHEAD OF FRONT WILL KEEP THE WARM AIR ACROSS THE
CWA. AFTER ANY MORNING FOG BURNS OFF...SUNNY SKIES WILL AGAIN
DOMINATE THE AREA. FCST SOUNDINGS SUGGEST THAT MIXING TO AROUND 850
MB (TEMPS AROUND 14C) WILL SUPPORT MAX READINGS INT THE UPPER 70S TO
NEAR 80.
&
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 332 PM EDT FRI SEP 26 2014
THE RELATIVELY WARM STREAK SEEN OVER THE PAST WEEK WILL COME TO AN
END EARLY NEXT WEEK AS A MORE PROGRESSIVE PATTERN DEVELOPS OVER THE
CENTRAL U.S.
SATURDAY NIGHT...WEAK MID-LEVEL RIDGING WILL BE OVER THE REGION AT
THE BEGINNING OF THE PERIOD AS A SLOW MOVING COLD FRONT STRETCHES
FROM NORTH DAKOTA TO HUDSON BAY. THIS FRONT WILL BE THE MAIN PLAYER
IN PRECIP CHANCES EARLY NEXT WEEK.
WITH THE LIGHT SOUTHERLY FLOW AND A CONTINUED INCREASE OF SFC
MOISTURE SATURDAY NIGHT...FOG WILL BE POSSIBLE ONCE AGAIN ACROSS THE
INTERIOR CENTRAL AND EAST. HOWEVER...DAYTIME MIXING ON SATURDAY MAY
LOWER DEWPOINTS FARTHER THAN MODELS ARE INDICATING. THIS LIKELY WILL
NOT BE REALIZED UNTIL SATURDAY AFTERNOON...SO WILL CONTINUE WITH THE
MENTION OF AREAS OF FOG.
SUNDAY...THE COLD FRONT WILL INCH CLOSER TO THE REGION ON
SUNDAY...BUT SHOULD HOLD OFF REACHING THE KEWEENAW UNTIL SUNDAY
EVENING. SUNDAY WILL BE THE LAST DAY IN THIS WARM STRETCH. WITH 850
HPA TEMPS STILL 12 TO 14C ACROSS THE CWA...HIGHS WILL BE WELL INTO
THE 70S FOR MUCH OF THE AREA. THESE VALUES ARE 15-20F ABOVE AVERAGES
IN THE LOW 60S THIS TIME OF YEAR. SEVERAL MODELS ARE INDICATING SOME
AFTERNOON DIURNAL SHOWERS ALONG THE LAKE BREEZE NORTH-CENTRAL. AM
STILL HAVING A HARD TIME BUYING INTO THIS AS LOW-LEVEL MOISTURE
APPEARS TO BE OVERDONE BY THE MODELS AND DEEP-LAYER MOISTURE IS
MARGINAL. DAYTIME MIXING ALONG WITH QUICKLY DIMINISHING
EVAPOTRANSPIRATION THIS TIME OF YEAR SHOULD LIMIT THE OVERALL SFC
MOISTURE AND INSTABILITY.
SUNDAY NIGHT AND MONDAY...THE COLD FRONT WILL ARRIVE ACROSS
THE KEWEENAW EARLY SUNDAY EVENING AND CONTINUE SINKING SOUTHWARD
THROUGH THE NIGHT. A DECENT AMOUNT OF LINEAR FORCING WILL BE
AVAILABLE THROUGH LOW-LEVEL FGEN...MID-LEVEL Q-VECTOR CONV...AND THE
RIGHT ENTRANCE OF AN UPPER JET. THIS SUGGESTS CONTINUING WITH LIKELY
POPS FOR MUCH OF THE AREA. TIMING OF THE PRECIP REMAINS A
SIGNIFICANT CHALLENGE DUE TO MODEL DIFFERENCE AND INCONSISTENCY. THE
12Z NAM SOLUTION HAS COME IN MUCH DIFFERENT FROM PREVIOUS RUNS AND
OTHER MODELS. THE SLOWER PROGRESSION OF THE TROUGH BY THE NAM DELAYS
PRECIP UNTIL LATE SUNDAY NIGHT. WITH THAT SAID MONDAYS FORECAST
BECOMES QUITE TRICKY AS THE TEMP AND PRECIP FORECAST HINGES ON HOW
FAR SOUTH THE FRONT MAKES IT SUNDAY NIGHT. A FASTER SOLUTION /ECMWF/
WOULD RESULT IN A MUCH COOLER DAY WITH SHOWERS FOR THE ENTIRE CWA. A
SLOWER SOLUTION /NAM/ WOULD ALLOW DIABATIC HEATING ACROSS THE
SOUTH-CENTRAL TO STALL THE FRONT EVEN MORE...BRINGING MUCH COOLER
CONDITIONS AND SHOWERS TO JUST THE NORTHERN CWA. HAVE OPTED TO TREND
TOWARD THE SLOWER IDEA AS EVEN THE 12Z GFS SLOWED THE PROGRESSION OF
THE FRONT. OVERALL...CONFIDENCE IS FAIRLY HIGH ON THE LIKELIHOOD OF
RAIN...BUT LOW ON THE TIMING.
MONDAY NIGHT AND TUESDAY...MID-LEVEL RIDGING WILL BEGIN BUILDING
ACROSS THE UPPER GREAT LAKES MONDAY NIGHT AS THE SFC FRONT CONTINUES
SSE OUT OF THE AREA. LOW-LEVEL MOISTURE WILL LINGER WELL INTO
TUESDAY WITH WEAK NE FLOW OFF LAKE SUPERIOR. THIS SHOULD LEAD TO AT
LEAST SOME UPSLOPE SHOWERS/DRIZZLE CENTRAL AND EAST ALONG LAKE
SUPERIOR THROUGH MONDAY NIGHT. THEN...AN INVERSION AROUND 3KFT
COMBINED WITH THE WEAKENING IMPACT OF THE SUN FOR MIXING...MAY KEEP
THE AREA SOCKED IN WITH LOW CLOUDS THROUGHOUT THE DAY TUESDAY. HAVE
THUS CONTINUED THE TREND OF LOWERING HIGH TEMPS FOR TUESDAY...WITH
HIGHS GENERALLY IN THE 50S CWA-WIDE. ALSO...WITH LOW-LEVEL HIGH
PRESSURE SHIFTING EASTWARD NORTH OF LAKE SUPERIOR AND INITIATING
RETURN SOUTHERLY FLOW ACROSS THE AREA...IT MAY EVEN BE DIFFICULT TO
COMPLETELY RID THE AREA OF LOW CLOUDS BY TUESDAY NIGHT.
WEDNESDAY THROUGH FRIDAY...DEEP TROUGHING OVER THE NORTHERN ROCKIES
WILL BE LIFTING NORTHEASTWARD AS MID-LEVEL RIDGING OVER THE UPPER
GREAT LAKES SHIFTS EASTWARD. MODEL GUIDANCE IS IN FAIRLY GOOD
AGREEMENT WITH THE SYNOPTIC PATTERN...BUT DIFFERS SOMEWHAT WITH THE
OVERALL INTENSITY OF THE TROUGH AND ASSOCIATED SFC LOW. ATTM...A
COLD FRONT IS PROGGED TO SLOWLY TRACK EASTWARD ACROSS THE CWA
WEDNESDAY MORNING THROUGH THURSDAY NIGHT AS THE SFC LOW MOVES
NORTHWARD OVER MANITOBA. WILL MAINTAIN CONSENSUS POPS...WITH AN
EMPHASIS FOR BETTER CHANCES ON THURSDAY WITH THE ARRIVAL OF
UPPER-LEVEL SUPPORT FROM THE RIGHT ENTRANCE OF A JET.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 721 PM EDT FRI SEP 26 2014
PLENTY OF DRY AIR ASSOCIATED WITH HI PRES CENTERED NEAR LK HURON
WILL BRING PREDOMINANT VFR CONDITIONS AND GENERALLY LIGHT WINDS AT
ALL 3 SITES THIS FCST PERIOD. FOG...WITH MVFR OR EVEN LOWER
VSBYS...IS POSSIBLE AT SAW TOWARD SUNRISE. A BIT STRONGER SSW FLOW
WILL LIMIT THE POTENTIAL FOR FOG AT CMX AND IWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 356 PM EDT FRI SEP 26 2014
A HIGH PRESSURE CENTERED OVER THE LOWER GREAT LAKES WILL REMAIN
STATIONARY THROUGH SUNDAY WHILE STRETCHING A RIDGE NORTHWEST ACROSS
THE UPPER GREAT LAKES. THIS WILL LEAD TO LIGHT SOUTHERLY FLOW
(BELOW 20KTS) INTO SUNDAY. A COLD FRONT DROPPING SOUTHEAST ACROSS
THE UPPER GREAT LAKES SUNDAY NIGHT INTO MONDAY MORNING WILL SHIFT
WINDS AROUND TO THE NORTHEAST WITH GUSTS TO 30KTS. HIGH PRESSURE
CENTERED OVER EASTERN CANADA WILL THEN PLACE A RIDGE OVER THE UPPER
GREAT LAKES FOR MONDAY NIGHT AND TUESDAY...LEADING TO DIMINISHING
WINDS.
WITH MORE MOIST AIR BEGINNING TO WORK NORTH OVER LAKE
SUPERIOR...THERE IS THE POTENTIAL FOR PATCHY/AREAS OF FOG OVER
NORTHERN PORTIONS OF LAKE SUPERIOR OVER THE NEXT COUPLE OF DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
247 AM EDT THU SEP 25 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 301 PM EDT WED SEP 24 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW AN UPR TROF FM
SCENTRAL CANADA THRU THE PLAINS IN BTWN A RDG OVER THE ROCKIES AND
ANOTHER CENTERED OVER THE ERN GREAT LKS. THERE ARE SEVERAL SHRTWVS
EMBEDDED WITHIN THE UPR TROF. ONE OF THESE IS MOVING NEWD THRU MN
AND IS CAUSING SCT SHOWERS IN WRN WI WHERE SOME DEEP LYR QVECTOR
CNVGC IN THE DPVA IS INTERACTING WITH SOME DEEP MSTR SHOWN ON THE
12Z MPX RAOB...WHERE THE PWAT WAS ABOUT 1.15 INCH OR 160 PCT OF
NORMAL. BUT THE RAOBS SHOW MUCH DRIER AIR IS PRESENT JUST TO THE E
OF THIS MOIST AIRMASS...WITH 12Z PWATS AS LO AS 0.46 INCH AT QUAD
CITIES IOWA /55 PCT OF NORMAL/ AND 0.62 INCH AT GRB /85 PCT OF
NORMAL/. THE 12Z H85 AND H7 DEWPT DEPRESSIONS AT THOSE 2 SITES WERE
20-30C. BECAUSE OF THE PRESENCE OF THIS DRY AIR...ONLY MID/HI CLDS
SO FAR HAVE INVADED UPR MI AHEAD OF THE UPR TROF. SOME OF THE
SHOWERS IN NW WI ARE APRCHG IRONWOOD.
MAIN FCST CONCERNS IN THE SHORT TERM REVOLVE ARND CLDS/POPS
ASSOCIATED WITH TROF TO THE W AND THE CLDS IMPACT ON TEMPS.
AS A DEEP UPR TROF OFF THE W COAST PRESSES TO THE E...THE TROF OVER
CENTRAL NAMERICA IS FCST TO WEEKEN STEADILY THRU THU UNDER THE
LARGER SCALE HGT RISES TO THE E OF THE TROF...INCLUDING IN THE GREAT
LKS. THE RESULT WL BE DIMINISHING DEEP LYR QVECTOR CNVGC...WITH DEEP
LYR QVECTOR DVGC DOMINATING THE ENTIRE CWA ON THU. SINCE THE LLVL
FLOW IS FCST TO VEER ONLY SLOWLY FM THE S TO THE SW...THE ADVECTION
OF THE VERY DRY LLVL AIR SHOWN ON THE QUAD CITIES/GRB RAOBS WL
AFFECT THE E HALF OF THE CWA THRU THU. SO IN THIS AREA...EXPECT ONLY
SOME MID/HI CLDS INTO THU. OVER THE W HALF...THE SLOWLY WEAKENING
DYNAMIC FORCING THRU THE NGT WL INTERACT WITH MOISTER AIR SHOWN ON
THE MPX RAOB AND FCST PWAT UP TO 160-170 PCT OF NORMAL TO GENERATE
SOME SCT LGT SHOWERS BEGINNING THIS AFTN. BUT THESE WL BEGIN TO FADE
ON THU IN THE FACE OF THE INCRSG DEEP LYR QVECTOR DVGC. AS FOR
TEMPS...THE GREATER INFLUX OF MSTR AND A STEADY SSW FLOW UNDER
SHARPENING PRES GRADIENT WL GREATLY RESTRICT THE DIURNAL TEMP DROP
OVER THE W AND HOLD MIN TEMPS IN THE 50S. WITH DRIER AIR/A BIT
WEAKER H925 FLOW OVER THE E...EXPECT TEMPS TO BOTTOM OUT IN THE 40S
ACROSS THE INTERIOR...LO ENUF TO ALLOW FOR SOME PATCHY FOG AS SHOWN
IN CURRENT FCST. WITH A GOOD DEAL OF LINGERING CLD COVER ON THU
ESPECIALLY OVER THE W...OPTED TO LOWER FCST HI TEMPS AT MOST PLACES
THERE INTO THE 60S. THE HIEST TEMPS ON THU INTO THE 70S ARE MOST
LIKELY OVER THE CENTRAL AND E AWAY FM THE MODERATING INFLUENCE OF LK
MI IN THE LLVL SLY FLOW AND WHERE THERE WL A BIT MORE SUNSHINE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 247 AM EDT THU SEP 25 2014
NAM SHOWS A 500 MB RIDGE IN THE UPPER GREAT LAKES 12Z FRI WITH A
TROUGH ON THE WEST COAST AND A WEAK TROUGH EMBEDDED IN THE RIDGE
OVER THE CENTRAL PLAINS. THIS WEAK TROUGH WILL FORM A CLOSED 500 MB
LOW FRI NIGHT AND THIS LOW WILL HEAD SLOWLY BACK TO THE NORTH AS THE
RIDGE GETS PUSHED SLOWLY TO THE EAST WITH A DEEP 500 MB TROUGH AND
CLOSED LOW THAT MOVES FROM THE WEST COAST INTO THE ROCKIES SAT NIGHT.
DRY AND QUIET WEATHER FOR THIS FORECAST PERIOD WITH TEMPERATURES
ABOVE NORMAL. WILL SEE SOME PATCHY FOG AT NIGHT AND EARLY IN THE
MORNING FOR FRI AND FRI NIGHT AS WINDS ARE LIGHT AND GOOD
RADIATIONAL COOLING SETS UP TO ALLOW RADIATION FOG TO FORM.
OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB CLOSED LOW AND TROUGH
OVER THE WESTERN U.S. 12Z SUN WITH A WEAK TROUGH AND UPPER LOW
EMBEDDED IN A RIDGE OVER THE CENTRAL AND EASTERN U.S. THIS TROUGH
SLOWLY MOVES TO THE EAST 12Z MON WITH A BACKDOOR COLD FRONT COMING
DOWN INTO THE AREA ON MON. THE 500 MB RIDGE BUILDS BACK INTO THE
UPPER GREAT LAKES 12Z TUE IN RESPONSE TO THE WESTERN U.S. TROUGH
DIGGING AND MOVING EASTWARD INTO THE ROCKIES. THE ROCKIES TROUGH
STARTS TO MOVE INTO THE PLAINS ON WED. THIS WILL MEAN ABOVE NORMAL
TEMPERATURES WILL CONTINUE THIS FORECAST PERIOD. WITH THE FRONT IN
THE AREA...CANNOT RULE OUT SOME POPS...BUT NOT A LOT OF MOISTURE TO
WORK WITH SO SLIGHT CHANCE POPS LOOK GOOD FOR NOW FOR MON AND TUE
NIGHT AND CHANCE POPS FOR WED AS THE FRONT DISSIPATES OVER THE
AREA...BUT A COLD FRONT DEVELOPS TO THE WEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 119 AM EDT THU SEP 25 2014
ALTHOUGH MID AND HIGH CLOUDS WILL PERSIST WITH THE APPROACH OF A
WEAKENING UPPER LEVEL DISTURBANCE...VFR CONDITIONS SHOULD PREVAIL AT
THE TAF SITES WITH A PERSISTENT FEED OF LOW LEVEL DRIER AIR. THE
ONLY EXCEPTION MAY BE AT IWD...WHICH IS CLOSER TO GREATER LOW LEVEL
MOISTURE. AS THE WINDS SLOWLY VEERS TOWARD THE SW...THE ARRIVAL OF
THE HIGHER MOISTURE SHOULD BRING A PERIOD OF MVFR CIGS THU MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 301 PM EDT WED SEP 24 2014
WITH A WEAK PRES GRADIENT DOMINATING THE UPPER GREAT LAKES INTO
EARLY NEXT WEEK AND COOL LAKE WATERS/HI STABILITY...EXPECT WINDS NO
HIER THAN 20 KTS THRU MON. WITH THE ARRIVAL OF MORE HUMID AIR OVER
THE UNUSUALLY COOL LK WATERS...SOME FOG MAY FORM LATE THU NIGHT INTO
FRI AND LATE FRI NIGHT INTO SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...07
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
120 AM EDT THU SEP 25 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 301 PM EDT WED SEP 24 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW AN UPR TROF FM
SCENTRAL CANADA THRU THE PLAINS IN BTWN A RDG OVER THE ROCKIES AND
ANOTHER CENTERED OVER THE ERN GREAT LKS. THERE ARE SEVERAL SHRTWVS
EMBEDDED WITHIN THE UPR TROF. ONE OF THESE IS MOVING NEWD THRU MN
AND IS CAUSING SCT SHOWERS IN WRN WI WHERE SOME DEEP LYR QVECTOR
CNVGC IN THE DPVA IS INTERACTING WITH SOME DEEP MSTR SHOWN ON THE
12Z MPX RAOB...WHERE THE PWAT WAS ABOUT 1.15 INCH OR 160 PCT OF
NORMAL. BUT THE RAOBS SHOW MUCH DRIER AIR IS PRESENT JUST TO THE E
OF THIS MOIST AIRMASS...WITH 12Z PWATS AS LO AS 0.46 INCH AT QUAD
CITIES IOWA /55 PCT OF NORMAL/ AND 0.62 INCH AT GRB /85 PCT OF
NORMAL/. THE 12Z H85 AND H7 DEWPT DEPRESSIONS AT THOSE 2 SITES WERE
20-30C. BECAUSE OF THE PRESENCE OF THIS DRY AIR...ONLY MID/HI CLDS
SO FAR HAVE INVADED UPR MI AHEAD OF THE UPR TROF. SOME OF THE
SHOWERS IN NW WI ARE APRCHG IRONWOOD.
MAIN FCST CONCERNS IN THE SHORT TERM REVOLVE ARND CLDS/POPS
ASSOCIATED WITH TROF TO THE W AND THE CLDS IMPACT ON TEMPS.
AS A DEEP UPR TROF OFF THE W COAST PRESSES TO THE E...THE TROF OVER
CENTRAL NAMERICA IS FCST TO WEEKEN STEADILY THRU THU UNDER THE
LARGER SCALE HGT RISES TO THE E OF THE TROF...INCLUDING IN THE GREAT
LKS. THE RESULT WL BE DIMINISHING DEEP LYR QVECTOR CNVGC...WITH DEEP
LYR QVECTOR DVGC DOMINATING THE ENTIRE CWA ON THU. SINCE THE LLVL
FLOW IS FCST TO VEER ONLY SLOWLY FM THE S TO THE SW...THE ADVECTION
OF THE VERY DRY LLVL AIR SHOWN ON THE QUAD CITIES/GRB RAOBS WL
AFFECT THE E HALF OF THE CWA THRU THU. SO IN THIS AREA...EXPECT ONLY
SOME MID/HI CLDS INTO THU. OVER THE W HALF...THE SLOWLY WEAKENING
DYNAMIC FORCING THRU THE NGT WL INTERACT WITH MOISTER AIR SHOWN ON
THE MPX RAOB AND FCST PWAT UP TO 160-170 PCT OF NORMAL TO GENERATE
SOME SCT LGT SHOWERS BEGINNING THIS AFTN. BUT THESE WL BEGIN TO FADE
ON THU IN THE FACE OF THE INCRSG DEEP LYR QVECTOR DVGC. AS FOR
TEMPS...THE GREATER INFLUX OF MSTR AND A STEADY SSW FLOW UNDER
SHARPENING PRES GRADIENT WL GREATLY RESTRICT THE DIURNAL TEMP DROP
OVER THE W AND HOLD MIN TEMPS IN THE 50S. WITH DRIER AIR/A BIT
WEAKER H925 FLOW OVER THE E...EXPECT TEMPS TO BOTTOM OUT IN THE 40S
ACROSS THE INTERIOR...LO ENUF TO ALLOW FOR SOME PATCHY FOG AS SHOWN
IN CURRENT FCST. WITH A GOOD DEAL OF LINGERING CLD COVER ON THU
ESPECIALLY OVER THE W...OPTED TO LOWER FCST HI TEMPS AT MOST PLACES
THERE INTO THE 60S. THE HIEST TEMPS ON THU INTO THE 70S ARE MOST
LIKELY OVER THE CENTRAL AND E AWAY FM THE MODERATING INFLUENCE OF LK
MI IN THE LLVL SLY FLOW AND WHERE THERE WL A BIT MORE SUNSHINE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 320 PM EDT WED SEP 24 2014
...WARMER THAN NORMAL INTO THE WEEKEND WITH QUIET WEATHER CONDITIONS...
SHORTWAVE TROUGH MOVING TOWARD THE UPPER GREAT LAKES THIS AFTN WILL
BE EXITING EAST OF THE REGION BY THURSDAY EVENING. HEIGHT RISES
SHOULD END ANY LGT RAIN SHOWERS EARLIER IN THE DAY...THOUGH A LOWER
MID CLOUD DECK 3-8KFT COULD REMAIN STUCK OVER AT LEAST WESTERN CWA
PER NAM AND GFS BUFKIT FORECAST SOUNDINGS. THESE CLOUDS SHOULD BEGIN
TO FADE LATER THURSDAY NIGHT OR MAYBE AS LATE AS FRIDAY MORNING
WITH SUBSIDENCE INCREASING AND SOME WEAK DRY ADVECTION BELOW THE
SUBSIDENCE INVERSION. WHILE THE WESTERN CWA WILL BE AFFECTED BY THE
CLOUDS THURSDAY NIGHT...EASTERN CWA SHOULD CLEAR OUT FM MID CLOUDS
EARLY IN THE EVENING...ALLOWING FOR BETTER RADIATIONAL COOLING AS
PWATS ARE BLO 50 PCT OF NORMAL. LOWERED MINS INTO THE MID 40S FOR
INTERIOR EAST AND ALSO ADDED FOG. WINDS ABOVE SHALLOW MOIST LAYER
ARE 10-15 KT FM THE SW...SO THERE IS POTENTIAL THAT FOG WOULD TURN
OUT TO BE VERY LOW LEVEL STRATUS DECK. BUILDING UPPER RIDGE AND
CLEARING OF THE LOW-MID CLOUDS BY MIDDAY FRIDAY SHOULD ALLOW MIXING
TO AT LEAST H875 AND POSSIBLY H85. EXPECT HIGHS WELL INTO THE 70S
OVER ALL CWA...EXCEPT NEAR LK MICHIGAN.
FRIDAY NIGHT INTO SATURDAY...QUIET CONDITIONS PREVAIL. UPPER RIDGE
SLIDES ACROSS. THERE IS SOME POTENTIAL THAT A REMNANT OF MID TO
UPPER TROUGH OVERHEAD INTO THURSDAY MAY TRY TO LIFT BACK TOWARD
AREA ON SATURDAY. MAY SEE REPEAT PERFORMANCE OF RADIATIONAL COOLING
LEADING TO FOG OR STRATUS ON FRIDAY NIGHT...ESPECIALLY FOR THE
INTERIOR CENTRAL AND EAST CWA WITH LIGHTER WINDS CLOSER TO SFC RIDGE
AXIS. ONLY SCT MID CLOUDS WOULD RESULT FM THE MID LEVEL ENERGY WEAK
AS IT IS...AND AT THIS POINT DO NOT EXPECT A BIG IMPACT TO THE
TEMPERATURE FORECAST. CAVEAT THOUGH IS WE ARE IN THAT TIME OF YEAR
WHERE SUN ANGLE IS LOWER SO IF LOW CLOUDS ARE MORE WIDESPREAD AND
THICKER THAN EXPECTED BASED ON FORECAST SOUNDINGS...THEY COULD TAKE
A WHILE TO BURN OFF /LATE MORNING INTO EARLY AFTN INSTEAD OF MID
MORNING EARLIER IN THE SUMMER/. OVERALL THOUGH...AT THE LEAST...MOST
AREAS AWAY FM LK MICHIGAN SHOULD SEE A DAY WITH HIGHS INTO THE MID
TO UPPER 70S AS H85 TEMPS PUSH 12-14C BY AFTN. NORMAL HIGHS FOR LATE
SEPTEMBER ARE LOW TO MID 60S.
WEAK UPPER TROUGH SHOULD BE IN THE VICINITY SATURDAY NIGHT INTO
SUNDAY...BUT MOISTURE IS LACKING /H7-H5 RH LESS THAN 50 PCT/ SO
ONLY EXPECT SCATTERED MID CLOUDS. SFC RIDGE STILL CLOSE BY WITH WEST
TO EAST AXIS MAINLY AFFECTING EASTERN CWA. PWATS ON THE INCREASE
WITH THE UPPER LOW REMNANT NEARBY...SO RADIATIONAL COOLING POTENTIAL
SEEMS LESS THAN PREVIOUS TWO NIGHTS. MINS SHOULD STAY MOSTLY IN THE
50S FOR THE CWA. INTO SUNDAY...DIFFERENCES BEGIN TO APPEAR WITH
REGARD TO HOW QUICKLY THE UPPER LEVEL FLATTENS OUT ALLOWING FOR A
BACK DOOR COLD FRONT TO WORK IN AS HIGH PRESSURE BUILDS FROM THE
CANADIAN PRAIRIES TO NORTHERN ONTARIO AND NORTHWEST QUEBEC. GEM-NH
AND ECMWF ARE QUICKER BRINGING THIS FRONT THROUGH...FAVORING A FROPA
ON SUNDAY NIGHT. MEANWHILE...GFS INSISTS ON A STRONGER SHORTWAVE
DROPPING THROUGH AND MORE OF A SFC TROUGH FORMING...KEEPING SW WINDS
OVER UPR MICHIGAN THROUGH MUCH OF MONDAY BEFORE FROPA OCCURS. WPC
AND CONSENSUS BLEND GOES AWAY FM THE GFS AND THIS FORECAST WILL DO
LIKEWISE. RESULT WILL BE MORE MAX TEMPS IN THE 70S AHEAD OF THE
FRONT ON SUNDAY...THEN A COOLING TREND FOR EARLY NEXT WEEK. RAIN
CHANCES SEEM SMALL AS STRONGER FORCING STAYS TO NORTH OF LK SUPERIOR
THROUGH MONDAY AND THERE IS MINIMAL THETA-E ADVECTION FOR FRONT TO
WORK WITH AS IT MOVES THROUGH. MAIN IMPACT WILL BE THE COOLING TREND
AND PROBABLY DECENT AMOUNT OF LOWER CLOUDS FOR MONDAY.
NEXT FRONTAL BOUNDARY ARRIVES BY MIDWEEK. MOISTURE ADVECTION BETTER
WITH THIS FRONT AS SOUTH WINDS BRING MORE MOISTURE INTO THE REGION.
COUPLE OF STRONGER SHORTWAVES SHOULD LIFT ACROSS AHEAD OF LARGER
SCALE TROUGHING SETTING UP OVER THE WESTERN HALF OF THE CONUS. TSRA
CHANCES SMALL AS AXIS OF HIGHER MLCAPES ARE FORECAST TO STAY TO WEST
OF CWA...CLOSER TO FRONT SIDE OF LARGER SCALE TROUGHING ALOFT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 119 AM EDT THU SEP 25 2014
ALTHOUGH MID AND HIGH CLOUDS WILL PERSIST WITH THE APPROACH OF A
WEAKENING UPPER LEVEL DISTURBANCE...VFR CONDITIONS SHOULD PREVAIL AT
THE TAF SITES WITH A PERSISTENT FEED OF LOW LEVEL DRIER AIR. THE
ONLY EXCEPTION MAY BE AT IWD...WHICH IS CLOSER TO GREATER LOW LEVEL
MOISTURE. AS THE WINDS SLOWLY VEERS TOWARD THE SW...THE ARRIVAL OF
THE HIGHER MOISTURE SHOULD BRING A PERIOD OF MVFR CIGS THU MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 301 PM EDT WED SEP 24 2014
WITH A WEAK PRES GRADIENT DOMINATING THE UPPER GREAT LAKES INTO
EARLY NEXT WEEK AND COOL LAKE WATERS/HI STABILITY...EXPECT WINDS NO
HIER THAN 20 KTS THRU MON. WITH THE ARRIVAL OF MORE HUMID AIR OVER
THE UNUSUALLY COOL LK WATERS...SOME FOG MAY FORM LATE THU NIGHT INTO
FRI AND LATE FRI NIGHT INTO SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
844 PM MDT FRI SEP 26 2014
.UPDATE...
COLD FRONT HAS PUSHED THROUGH THE FORECAST AREA THIS EVENING AND
IS LOCATED FROM THE WESTERN DAKOTAS SOUTHWEST INTO CENTRAL WYOMING
AT 8 PM. COOLER AIR AND NORTHEASTERLY WINDS HAVE DEEPENED UP TO
AROUND 5000 FEET OVER THE PAST FEW HOURS. OVER THE TOP OF THIS
FRONTAL BOUNDARY JET DYNAMICS COMBINED WITH THE FRONTAL
CONVERGENCE ARE PRODUCING ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WEST OF A ROUNDUP TO BILLINGS LINE. THESE CELLS ARE
MOVING TO THE NORTH AT 20 TO 30 MPH. ANOTHER AREA OF STRONGER JET
DYNAMICS IS LOCATED OVER EASTERN IDAHO AT THIS TIME AND THIS WILL
PUSH INTO THE WESTERN HALF OF THE FORECAST AREA OVERNIGHT INTO
TOMORROW MORNING. HI-RES MODELS HINTING AT A GOOD AREA OF SHOWER
ACTIVITY ALONG THE WESTERN FOOTHILLS AND MOUNTAINS...AS WELL AS A
PERSISTENT NORTH/SOUTH ORIENTED BAND OF SHOWERS SETTING UP
SOMEWHERE BETWEEN BILLINGS AND BIG TIMBER AROUND SUNRISE.
INCREASED POPS 10 TO 20 PERCENT FROM ROUNDUP AND BILLINGS WEST TO
THE FOOTHILLS TO ACCOUNT FOR THIS EXPECTED ACTIVITY. LATEST MODELS
PUSH JET FORCING A BIT FURTHER EAST IN THE MORNING AND LATE
AFTERNOON TOMORROW. ADDED SOME LOW POPS AS FAR EAST AS ROSEBUD
COUNTY TO ACCOUNT FOR THIS VARIABILITY AND SPREAD LIKELY POPS AS
FAR EAST AS A ROUNDUP TO NYE LINE. BUMPED CLOUD COVER SOME TO
ACCOUNT FOR INCREASE IN PRECIPITATION POTENTIAL AND COVERAGE. REST
OF THE FORECAST IS IN GOOD SHAPE. CHAMBERS
&&
.SHORT TERM...VALID FOR SAT AND SUN...
COLD FRONT HAS OOZED THROUGH MOST OF THE AREA BUT WITH STRONGER
COLD ADVECTION NOT OCCURRING UNTIL TONIGHT. TEMPS HAVE WARMED INTO
THE 80S AND LOWER 90S THIS AFTERNOON...WITH 2PM TEMP OF 93F AT
SHERIDAN TYING A RECORD FOR THE DAY. BILLINGS WINDS HAVE SHIFTED
TO THE NE AND LOW LEVEL CONVERGENT AREA LONG WITH WEAK ENERGY FROM
THE SW ALLOWING FOR A CU FIELD TO FORM FROM BILLINGS WEST...WITH
LATEST RADAR SHOWING WEAK ECHOES IN PARK AND SWEET GRASS
COUNTIES. AREAS FROM BILLINGS WEST CAN EXPECT ISOLATED SHOWERS/
TSTMS THROUGH THE EARLY EVENING HOURS...THIS REMAINS CONSISTENT
WITH RECENT HRRR RUNS...WITH THE EAST REMAINING DRY/CLEAR. MAIN
FORECAST ISSUE CONTINUES TO REVOLVE AROUND DEEP PACIFIC TROF WHICH
IS PUSHING SLOWLY INLAND AND WILL BEGIN TO IMPACT OUR WEST LATER
TONIGHT.
OVERALL THEME OF FORECAST REMAINS UNCHANGED TODAY. PCPN CHANCES
WILL INCREASE WEST OF BILLINGS LATER TONIGHT...WITH RAIN LIKELY
WEST OF BILLINGS SATURDAY...THEN BECOMING LIKELY ACROSS THE CWA
SATURDAY NIGHT THROUGH SUNDAY NIGHT AS UPPER LOW SHIFTS TO OUR
SOUTH LEAVING OUR REGION IN A FAVORABLE DIFFLUENT REGION ALOFT.
HAVE ADJUSTED POPS A BIT...WITH THE MAIN CHANGE BEING TO DRY OUT
BILLINGS ON SATURDAY. STRONGER FORCING SHOULD STAY TO OUR WEST...
WITH COOLER LOW LEVEL NE WINDS KEEPING OUR AIRMASS STABLE WITH
WITH A 5-6KFT CLOUD DECK. THIS MAY SUPPORT A FEW SPRINKLES BUT
SHOULD NOT BE ANYTHING MORE THAN THAT IF YOU ARE PLANNING TO BE
OUTDOORS IN BILLINGS ON SATURDAY. OTHER CHANGE WAS TO RAISE POPS
NEAR SHERIDAN AND LAME DEER SUNDAY NIGHT AS ALL MODELS SHOW
STRONGER PIECE OF ENERGY LIFTING OUT OF WYOMING. COULD ALSO BE
SOME TSTMS WITH ELEVATED INSTABILITY IN OUR SOUTHEAST.
IMPACTS WITH THIS SYSTEM WILL NOT BE GREAT. COULD SEE SOME WET
SNOW OVER THE HIGHEST PEAKS INCLUDING BEARTOOTH PASS BY SATURDAY
NIGHT...BUT SNOW LEVELS LOOK TO STAY UP NEAR 10KFT. OTHERWISE WE
ARE TALKING ABOUT A COUPLE DAYS OF MUCH COOLER AND OCCASIONALLY
WET WEATHER...WITH PCPN TOTALS NEAR AN INCH IN PLACES BY SUNDAY
NIGHT ESPECIALLY IN OUR WESTERN UPSLOPE AREAS...ALONG WITH A
HEALTHY NE WIND. THOUGH IT WILL BE A COLD RAIN...DO NOT THINK
FOOTHILL LOCATIONS SUCH AS RED LODGE AND STORY WILL SEE SNOW THIS
TIME.
AFTER NEAR RECORD HEAT AGAIN TODAY WE WILL SEE TEMPS DROP
SIGNIFICANTLY FOR SATURDAY AND CLOSER TO LATE SEPTEMBER NORMALS.
SUNDAY WILL BE EVEN COOLER WITH HIGHS ONLY IN THE UPPER 40S AND
50S ACROSS MOST LOWER ELEVATIONS.
JKL
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
LARGE UPPER TROUGH WILL BE TRACKING THROUGH THE NORTHERN AND
CENTRAL ROCKIES TO START THE EXTENDED. MODELS HAVE COME INTO GOOD
AGREEMENT THROUGH MONDAY NIGHT...BUT HAVE SOME SIGNIFICANT AND
CRITICAL DIFFERENCES THROUGH TUESDAY EVENING.
A STRONG SHORT WAVE WILL LIFT ACROSS THE FORECAST AREA FROM THE
SOUTH ON THE FRONT SIDE OF THE TROUGH MONDAY. MODELS VERY MUCH IN
AGREEMENT SO ADJUSTED POPS FOR THIS FEATURE WHICH HITS MAINLY
EASTERN ZONES. GFS THEN HAS UPPER CLOSED LOW THAT LIFTS THROUGH SE
MONTANA MONDAY NIGHT INTO TUESDAY WHILE ECMWF KEEPS SYSTEM OPEN
AND TRACKS IT FURTHER SOUTH. THE GFS SOLUTION IS THUS MUCH MORE
BULLISH WITH SIGNIFICANT QPF OVER OUR EAST TUESDAY DUE TO TROWAL
TYPE DEVELOPMENT...BUT THE ECMWF SCENARIO KEEPS THE FORCING IN
THE DAKOTAS. GEM ALSO KEEPS WAVE OPEN SIMILAR TO THE ECMWF. I HAVE
THEREFORE USED A BLEND WHILE LEANING TOWARD THE LESS AGGRESSIVE
ECMWF SOLUTION.
THE LONG WAVE PATTERN REMAINS CYCLONIC THE REST OF THE WORK WEEK
WITH THE MODELS HAVING DIFFERENCES TRYING TO TIME SOME SHORT WAVES
WITHIN THE MEAN FLOW. SO SOME UNSETTLED WEATHER IS EXPECTED WITH
SEASONABLE TEMPERATURES. BT
&&
.AVIATION...
VFR CONDITIONS WILL GENERALLY PREVAIL THROUGH THIS EVENING.
HOWEVER...LOCAL MVFR CONDITIONS ARE POSSIBLE TONIGHT DUE TO
LOWERED VISIBILITY IN SHOWERS AND THUNDERSTORMS...MAINLY ALONG AND
WEST OF A ROUNDUP TO BILLINGS LINE. GUSTY NORTHEASTERLY WINDS
WILL CONTINUE THROUGH THE DAY SATURDAY. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 055/065 045/054 043/064 049/066 045/060 042/057 042/064
23/T 66/W 63/W 22/W 22/W 02/W 20/U
LVM 050/059 045/055 040/064 044/064 037/058 035/057 036/065
67/T 87/W 63/W 33/W 32/W 12/W 21/B
HDN 051/070 047/057 043/066 048/068 044/061 041/060 040/066
12/T 66/W 63/W 22/W 22/W 02/W 20/U
MLS 055/073 047/057 043/064 050/066 046/062 041/059 041/065
00/B 35/W 55/T 33/W 22/W 12/W 21/B
4BQ 055/076 049/060 044/065 051/064 044/059 039/058 039/063
00/U 24/T 64/T 33/T 22/W 12/W 21/U
BHK 055/077 048/058 041/061 050/064 044/060 039/057 037/060
00/U 24/W 55/T 74/T 22/W 12/W 21/B
SHR 052/073 048/057 042/066 046/065 042/056 037/057 036/064
00/B 35/T 73/W 23/W 22/W 02/W 20/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1016 AM EDT THU SEP 25 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL BE MOVING UP THE EASTERN SEABOARD TODAY
AND SPREAD HIGH LEVEL CLOUDS INTO THE REGION...BUT NO PRECIPITATION.
HIGH TEMPERATURES WILL BE A FEW DEGREES ABOVE SEASONAL NORMALS...BUT
SLIGHTLY COOLER THAN YESTERDAY. A WARMING TREND WILL TAKE PLACE
FRIDAY THROUGH SUNDAY AS A LARGE UPPER LEVEL RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION. EXPECT PLENTY OF SUNSHINE AND HIGH
TEMPERATURES ON THE ORDER OF 10 TO 15 DEGREES ABOVE NORMAL FOR THIS
TIME OF YEAR.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 1016 AM EDT THURSDAY...A FEW SLIGHT MODIFICATIONS TO CLOUD
COVER TODAY BASED ON MORNING VISIBLE SATELLITE PRESENTATION AND
LATEST RAP RH FIELDS. THIS CHANGE ESSENTIALLY KEEPS PARTLY CLOUDY
SKIES /MAINLY MID-HIGH CLOUDS/ ACROSS RUTLAND/WINDSOR COUNTIES
THROUGH THE AFTN. TEMPS IN THE ST. LAWRENCE VALLEY WERE ALSO
SEVERAL DEGREES WARMER THAN INHERITED HOURLY TEMPS...AND WITH
MOSTLY CLEAR SKIES TODAY I`VE ADJUSTED HIGHS UP TO THE UPPER 70S
THERE. FINALLY...KEPT RIVER VALLEY FOG GOING A LITTLE WHILE LONGER
ACROSS EASTERN VT. THE CLOUDS LIMITING CONVECTIVE MIXING MAY
ACTUALLY HELP MAINTAIN THE RIVER VALLEY FOG ALONG THE LOWER CT
RIVER VALLEY. DRY FORECAST STILL LOOKS GOOD AS RAIN SHIELD OVER
SOUTHERN NEW ENGLAND HAS A SUBSTANTIAL LAYER OF LOW-LEVEL DRY AIR
UNLIKELY TO BE OVERCOME - EVIDENT IN 12Z GYX/ALB RAOBS.
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 644 AM EDT FOLLOWS...
GOING FORECAST IN GOOD SHAPE WITH JUST A FEW TWEAKS TO THE
TEMPERATURES AND DEW POINTS IN ORDER TO MATCH A BIT BETTER WITH
CURRENT CONDITIONS. OTHERWISE...OTHER THAN SOME FOG EARLY THIS
MORNING...JUST LOOKING AT INCREASING HIGH CLOUDS ACROSS THE REGION
TODAY AS A LOW PRESSURE SYSTEM MOVES UP THE EASTERN SEABOARD. THE
CLOUDS WILL BE THICK ENOUGH OVER THE SOUTHERN HALF OF THE AREA TO
HAVE SOME OBSTRUCTION TO THE SUN WITH MOSTLY SUNNY CONDITIONS
EXPECTED OVER THE NORTHERN AREAS. THIS WILL HAVE SOME IMPACT ON
HIGH TEMPERATURES TODAY WITH READINGS A DEGREE OR TWO COOLER THAN
YESTERDAY...BUT STILL A FEW DEGREES ABOVE NORMAL. TRENDS IN THE
NEW DATA SUGGEST ANY PRECIPITATION SHOULD REMAIN SOUTH OF THE AREA
TODAY...SO HAVE REMOVED ANY MENTION OF SHOWERS ACROSS PORTIONS OF
SOUTH CENTRAL VERMONT TODAY.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY/...
AS OF 245 AM EDT THURSDAY...THE HIGH CLOUDS WILL GRADUALLY EXIT THE
AREA AND FOG SHOULD ONCE AGAIN DEVELOP IN THE FAVORED LOCATIONS.
LARGE UPPER LEVEL RIDGE DEVELOPS OVER THE AREA FRIDAY THROUGH
SATURDAY. SO DRY WEATHER WILL CONTINUE...THERE WILL BE PLENTY OF
SUNSHINE...AND LOW LEVEL TEMPERATURES WARM A COUPLE OF DEGREES
EACH DAY FOR A WARMING TREND DURING THE PERIOD. HIGHS BY SATURDAY
SHOULD RANGE FROM THE LOWER 70S TO LOWER 80S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 320 AM EDT THURSDAY...LITTLE CHANGE FROM THE PREVIOUS COUPLE
OF FORECAST WITH REGARDS TO DAYS 4 THROUGH 7. STILL ANTICIPATING MUCH
ABOVE NORMAL TEMPS FOR SUNDAY INTO MONDAY...WITH A COOLING TREND
BY EARLY NEXT WEEK. ALSO...NOT EXPECTING MUCH QPF OVER THE NEXT 7
TO 10 DAYS...VERY DRY PATTERN CONTINUES WITH NORTHWEST FLOW ALOFT.
FOR SUNDAY...MID/UPPER LEVEL RIDGE DIRECTLY OVERHEAD AND PROGGED 85H
TEMPS NEAR 15C....SUPPORT HIGHS WELL INTO THE M/U 70S MTNS TO L/M
80S WARMER VALLEYS. HAVE BUMPED TEMPS ANOTHER DEGREE OR TWO FROM
PREVIOUS FORECASTER BASED ON LATEST LLVL THERMAL PROFILES. A QUICK
REVIEW OF RECORD HIGHS ON SUNDAY SHOW 82 AT BTV...80 AT MPV...AND
85 AT MSS...A FEW OF THESE RECORDS MAYBE IN JEOPARDY. LOWS SAT
NIGHT AND SUNDAY NIGHT WILL RANGE FROM THE M40S COLDER MOUNTAIN VALLEYS
TO M/U 50S WARMER VALLEYS AND MID SLOPE AREAS....AS STRONG
NOCTURNAL LLVL INVERSIONS DEVELOP EACH NIGHT. WINDS WILL BE TERRAIN
DRIVEN WITH DOWNSLOPE FLOW ASSOCIATED WITH THERMAL DIFFERENCES AND
IMPACT OF TERRAIN ON FLOW. ON MONDAY...A WEAK BACK DOOR COLD FRONT
DROPS INTO OUR REGION...WITH A WIND SHIFT AND SLIGHTLY COOLER
TEMPS. ECMWF STILL IS THE MOST AGGRESSIVE WITH LLVL CAA AND RIBBON
OF DEEPER 850 TO 500MB RH. HAVE CONTINUED WITH SLIGHT CHANCE WORDING FOR
PRECIPITATION ON MONDAY...WITH GREATEST CHANCES ACROSS THE NORTHERN MTNS. QPF
WILL BE VERY LIGHT...IF ANY AT ALL. TEMPS MONDAY INTO EARLY NEXT
WEEK WILL BE TRICKY...AS A NOTICEABLE DIFFERENCE OCCURS IN THE LATEST
GUIDANCE. ECMWF IS MUCH COOLER...WHILE GFS SHOWS VERY LITTLE
CHANGE IN LLVL THERMAL PROFILES. HAVE USED A BLEND/COMPROMISE BETWEEN
PREVIOUS FORECAST AND LATEST GUIDANCE...WHICH SUPPORT HIGHS IN THE 60S
TO L70S AND LOWS MAINLY IN THE 40S TO MID 50S...STILL SEVERAL
DEGREES ABOVE NORMAL FOR LATE SEPT/EARLY OCT. NO SIGNIFICANT PRECIPITATION
IS ANTICIPATED OVER THE NEXT 7 TO 10 DAYS ACROSS OUR AREA.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
THROUGH 12Z FRIDAY...VLIFR CONDITIONS IN FOG WL PREVAIL AT SLK
THRU 13Z AND MPV THRU 14 THIS MORNING...BASED ON PREVIOUS MORNING
TRENDS. OTHERWISE...MID/UPPER LVL CLOUDS WL SPREAD FROM SOUTH TO
NORTH ACRS OUR TAF SITES THIS MORNING...BEFORE DISSIPATING BY
MIDDAY. LOOK FOR VFR CONDITIONS WITH LIGHT SOUTHERLY WINDS AT 3
TO 7 KNOTS TODAY. ONCE AGAIN FOG/BR WL DEVELOP AT SLK/MPV BTWN
04Z-06Z WITH LIFR CONDITIONS LIKELY BTWN 06Z-12Z FRIDAY. IN
ADDITION...SOME PERIODS OF IFR CONDITIONS ARE POSSIBLE AT
MSS/PBG...WITH LIGHT WINDS PREVAILING. SKIES WL REMAIN MOSTLY CLR
AWAY FROM AREAS OF FOG/BR.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...SFC HIGH PRES WILL RESULT IN
VFR CONDITIONS WITH EXCEPTION OF MORNING IFR/LIFR CONDITIONS IN
FOG/BR AT MPV/SLK AND MSS BETWEEN 06Z-12Z.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...EVENSON
NEAR TERM...EVENSON/LOCONTO
SHORT TERM...EVENSON
LONG TERM...TABER
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
258 PM EDT THU SEP 25 2014
.SYNOPSIS...
CLOUDY AND DAMP WEATHER WILL CONTINUE THIS AFTERNOON AND EVENING
AS A COASTAL TROUGH LINGERS NEAR THE COAST. A WARMER AND DRIER
PERIOD OF WEATHER IS EXPECTED AS HIGH PRESSURE BUILDS SOUTH INTO
THE CAROLINAS OVER THE WEEKEND. MOISTURE WILL RETURN NORTHWARD
EARLY NEXT WEEK BRINGING A RETURN TO MORE CLOUDINESS AND INCREASED
RAIN CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM THURSDAY...COASTAL TROUGH REMAINS STALLED OFFSHORE WITH
WEAK SURFACE WAVE/LOW EXITING NORTHEAST. ANOTHER WEAK LOW IS
APPARENT OFF THE EAST COAST OF FL...ALSO ASSOCIATED WITH THE
COASTAL TROUGH. AS THIS LOW MOVES NORTH ALONG THE TROUGH IT WILL
TRY TO PUSH THE BOUNDARY ONSHORE...BUT A FEW FACTORS MAKE THIS
UNLIKELY. HIGH PRESSURE CONTINUES TO BUILD DOWN THE EAST COAST
FROM NEW ENGLAND WITH NORTHERLY FLOW...AND AT TIMES EVEN A LITTLE
WEST OF DUE NORTH...HELPING KEEP THE BOUNDARY AWAY FROM THE COAST.
DEEPENING SURFACE LOW EAST OF THE DELMARVA PENINSULA AND THE WEAK
SURFACE WAVE EXITING NORTHEAST WILL ALSO WORK TO ENHANCE NORTHERLY
FLOW.
WITH SURFACE BOUNDARY EXPECTED TO REMAIN FARTHER OFFSHORE THE
POTENTIAL FOR HEAVY RAIN DECREASES. LIGHT RAIN AND DRIZZLE WILL
REMAIN A POSSIBILITY CLOSER TO THE COAST...BUT HEAVY STRATIFORM
RAIN IS LESS LIKELY. IT APPEARS THE AREA MOST FAVORABLE FOR HEAVY
RAIN WILL REMAIN OFFSHORE. AS THE HIGH BUILDS DOWN THE COAST THE
GRADIENT BECOMES MORE DEFINED...INCREASING BOUNDARY LAYER WINDS.
THIS WILL LIMIT FOG POTENTIAL AS WELL AS KEEP TEMPERATURES IN THE
LOW TO MID 60S WITH POTENTIAL FOR UPPER 60S ALONG THE IMMEDIATE
COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WILL BUILD SOUTH THROUGH THE
SHORT TERM...VERY GRADUALLY PUSHING THE COASTAL TROUGH AND ITS
ATTENDANT MOISTURE AND PRECIPITATION OUT OF THE PICTURE AS WE MOVE
INTO THE WEEKEND. THE FRONT WILL ALSO BEGIN TO WASH OUT DURING
THIS PERIOD AS IT PUSHES SOUTH. MODEL SOUNDINGS DO CONTINUE TO
SHOW A NEARLY SATURATED COLUMN ON FRIDAY...SO EXPECT CONTINUED
EXTENSIVE CLOUD COVER THROUGHOUT THE CWA AND A GRADIENT OF POPS
WITH THE BEST CHANCES NEARER THE COAST AND SLIGHT CHANCE WELL
INLAND. WEATHER CONTINUES TO IMPROVE ON SATURDAY AS P/W VALUES
FINALLY DIP BACK BELOW 2 INCHES. HOWEVER...MODEL SOUNDINGS DO SHOW
SUBSTANTIAL LOW LEVEL MOISTURE ON SATURDAY THOUGH...SO EXPECT
EXTENSIVE FIELDS OF CU TO TO DEVELOP IN THE AFTERNOON WHEREVER WE
DO GET BREAKS IN THE STRATUS...ALONG WITH THE SLIGHT CHANCE OF
SHOWERS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...HIGH PRESSURE EXTENDING SOUTH INTO THE
CAROLINAS WILL WEAKEN THROUGH EARLY NEXT WEEK. UPPER RIDGE ALIGNED
UP THE EAST COAST ON SUNDAY WILL PRODUCE INCREASED SUBSIDENCE AND
DRY AIR ALOFT THROUGH SUNDAY. DRY AIR SHOULD PUSH FAR ENOUGH SOUTH
TO CLEAR THE LOCAL FORECAST AREA LEAVING ANY LINGERING MOISTURE TO
THE SOUTH. THEREFORE EXPECT PLENTY OF SUNSHINE WITH TEMPS WARMING
INTO THE 80S MOST PLACES.
BY MONDAY THE RIDGE WILL SLIP SOUTH AND WEAKEN AS SHORTWAVE
APPROACHES FROM THE WEST. THIS WILL PRODUCE DEEPER LAYER SW FLOW
OF MOISTURE AND INCREASED UPPER LEVEL SUPPORT. PCP WATER VALUES AS
LOW AS AN INCH ON SUNDAY WILL BE BACK UP TO 2 INCHES PLUS BY LATER
ON MONDAY. THEREFORE EXPECT INCREASING CLOUDS FROM THE SOUTH AND
POTENTIAL FOR SHOWERS BY LATE MONDAY INTO TUES. SFC LOW ASSOCIATED
WITH THIS SHORTWAVE WILL MOVE ACROSS THE SOUTHEAST THROUGH TUESDAY
FINALLY SHIFTING OFF SHORE BY WED MORNING. EXPECT BEST CHC OF MORE
WIDESPREAD PCP THROUGH TUES AS THIS LOW PRESSURE MOVES THROUGH.
SHOULD SEE DRYING ON BACK END OF THIS SYSTEM THROUGH WED...AT
LEAST THROUGH THE MID LEVELS. AS SFC HIGH BUILDS DOWN FROM THE
NORTH SHOULD SEE SOME CLEARING OUT BUT ECMWF IS HINTING AT ANOTHER
WEDGE SETTING UP FOR MID WEEK. TEMPS WILL REMAIN AT OR SLIGHTLY
ABOVE CLIMO TO START BUT OVERALL NOT STRAYING TO FAR FROM
NORMAL...WITH HIGHS AROUND 80 AND LOWS CLOSER TO 60.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...IFR CIGS WILL BRIEFLY IMPROVE TO MVFR LATER THIS AFTN
BEFORE DROPPING BACK DOWN BELOW 1KFT TONIGHT. SURFACE OBS INDICATE
CIGS ARE GRADUALLY LIFTING...SO WOULD EXPECT TO START SEEING TAF
SITES IMPROVE TO MVFR BY 19-20Z. DEVELOPING LOW PRESSURE IS
KEEPING THE COASTAL TROUGH OFFSHORE...AND THUS HAVE REMOVED -RA
FROM THE TAFS. THE HRRR SHOWS LITTLE TO NO ADDITIONAL PCPN FOR THE
TERMINALS TODAY...EVEN ALONG THE COAST. NORTHEAST WINDS AOB 10 KT
WILL PREVAIL THROUGH THE DAY. THE WEDGE REASSERTS ITSELF TONIGHT
AS HIGH PRESSURE BUILDS SOUTHWARD AND THE GRADIENT TIGHTENS.
EXPECT NORTHEAST WINDS INCREASING TO 6-10 KT OVERNIGHT...WHICH
SIGNIFICANTLY LOWERS THE FOG THREAT AS COMPARED TO THIS MORNING.
BUT IFR STRATUS WILL FILL BACK IN AFTER MIDNIGHT AND PERSIST
THROUGH MUCH OF FRI MORNING...WITH LIFR CONDITIONS POSSIBLE IN THE
PRE-DAWN HOURS.
EXTENDED OUTLOOK...MVFR/IFR CIGS POSSIBLE SAT MORNING. OTHERWISE
VFR SAT/SUN. CHANCE OF SHOWERS ON MON AND TUE. MON.
&&
.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 2 PM THURSDAY...NORTHERLY FLOW WILL START INCREASING LATER
THIS AFTERNOON...EVENTUALLY REACHING 15 TO 20 KT...AS HIGH PRESSURE
BUILDING DOWN THE COAST STRENGTHENS. THE STRONGER HIGH WILL HELP
PUSH THE COASTAL TROUGH EAST OF THE WATERS OVERNIGHT. THIS WILL
SPREAD 15 TO 20 KT NORTHERLY FLOW OVER ALL ZONES. THE ENHANCED
NORTHERLY FLOW COULD PUSH SEAS IN SOME AREAS TO 5 FT...MAINLY IN THE
VICINITY OF FRYING PAN SHOALS AND EAST OF CAPE ROMAIN. AT THIS POINT
WILL NOT RAISE A SCEC FOR ANY ZONE...BUT SHOULD NORTHERLY SURGE END
UP A LITTLE STRONGER...EITHER DUE TO INCREASED STRENGTH OF SURFACE
HIGH OR MORE INTENSIFICATION OF WEAK LOW MOVING NORTH ALONG THE
TROUGH...SCEC HEADLINES MAY BE REQUIRED.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...NORTHEAST WINDS IN THE 15 KT RANGE WILL
CONTINUE THROUGH THE PERIOD AS HIGH PRESSURE PRESSES DOWN FROM THE
NORTH. A SMALL CRAFT ADVISORY MAY BE REQUIRED ON FRIDAY NIGHT FOR
6 FT SEAS TOUCHING OUR OUTER WATERS...OTHERWISE MOST PLACES WILL
SEE 3 TO 5 FT THROUGH THE PERIOD.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...HIGH PRESSURE SPREADS SOUTH AND EAST THROUGH
SUNDAY INTO MONDAY WITH GRADIENT RELAXING ALLOWING WINDS TO SHIFT
FROM N-NE AROUND 15 KTS TO A MORE EASTERLY DIRECTION....10 KTS OR
LESS. BY MONDAY LOW PRESSURE MOVES UP FROM THE SOUTHWEST WITH A
TROUGH ALIGNED ALONG THE SOUTHEAST COAST BY MONDAY
NIGHT...SHIFTING WINDS TO THE S-SE AHEAD OF TROUGH AND N-NE TO THE
WEST OF TROUGH AXIS. TROUGH SHOULD MOVE TO THE EAST TO NORTHEAST
THROUGH TUES WITH WINDS BECOMING MORE NORTHERLY ON THE BACK END BY
LATE TUES AND CONTINUING THROUGH MID WEEK. SEAS 2 TO 4 FT EARLY
SUNDAY WILL SUBSIDE IN LIGHTER WINDS THROUGH MONDAY. MAY SEE A
SLIGHT INCREASE IN SEAS IN INCREASED NORTHERLY WINDS BY WED
MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...REK
NEAR TERM...III
SHORT TERM...REK/MBB
LONG TERM...RGZ
AVIATION...BJR
MARINE...REK/III/RGZ
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
210 PM EDT THU SEP 25 2014
.SYNOPSIS...
CLOUDY AND DAMP WEATHER WILL CONTINUE THIS AFTERNOON AS A COASTAL
TROUGH LINGERS NEAR THE COAST. AS THE HIGH BUILDS WEST INTO THE
CAROLINAS OVER THE WEEKEND...A WARMER AND DRIER PERIOD OF WEATHER
IS EXPECTED. THIS MOISTURE WILL RETURN NORTHWARD EARLY NEXT WEEK
BRINGING A RETURN OF MORE CLOUDINESS AND RAIN CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM THURSDAY...COASTAL TROUGH REMAINS STALLED OFFSHORE WITH
WEAK SURFACE WAVE/LOW EXITING NORTHEAST. ANOTHER WEAK LOW IS
APPARENT OFF THE EAST COAST OF FL...ALSO ASSOCIATED WITH THE COASTAL
TROUGH. AS THIS LOW MOVES NORTH ALONG THE TROUGH IT WILL TRY TO PUSH
THE BOUNDARY ONSHORE...BUT A FEW FACTORS MAKE THIS UNLIKELY. HIGH
PRESSURE CONTINUES TO BUILD DOWN THE EAST COAST FROM NEW ENGLAND
WITH NORTHERLY FLOW...AND AT TIMES EVEN A LITTLE WEST OF DUE
NORTH...HELPING KEEP THE BOUNDARY AWAY FROM THE COAST. DEEPENING
SURFACE LOW EAST OF THE DELMARVA PENINSULA AND THE WEAK SURFACE WAVE
EXITING NORTHEAST WILL ALSO WORK TO ENHANCE NORTHERLY FLOW.
WITH SURFACE BOUNDARY EXPECTED TO REMAIN FARTHER OFFSHORE THE
POTENTIAL FOR HEAVY RAIN DECREASES. LIGHT RAIN AND DRIZZLE WILL
REMAIN A POSSIBILITY CLOSER TO THE COAST...BUT HEAVY STRATIFORM RAIN
IS LESS LIKELY. IT APPEARS THE AREA MOST FAVORABLE FOR HEAVY RAIN
WILL REMAIN OFFSHORE. AS THE HIGH BUILDS DOWN THE COAST THE GRADIENT
BECOMES MORE DEFINED...INCREASING BOUNDARY LAYER WINDS. THIS WILL
LIMIT FOG POTENTIAL AS WELL AS KEEP TEMPERATURES IN THE LOW TO MID
60S WITH POTENTIAL FOR UPPER 60S ALONG THE IMMEDIATE COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...MID LEVEL RIDGE OVER THE GREAT LAKES STARTS
MEETING UP WITH SAME OVER BAHAMAS ON FRIDAY WHILE WEAK TROUGHINESS
SITS OFF THE NORTHEAST AND A WEAK FEATURE CUT OFF FROM THE FLOW
MEANDERS OVER IOWA. THIS CAUSES A MAINLY LATE-DAY WEAK PUSH OF
SURFACE HIGH PRESSURE FURTHER INTO THE CAROLINAS LEADING TO SOME LOW
LEVEL DRY AIR ADVECTION. SOME MINOR RAIN CHANCES ARE TOUGH TO RULE
OUT AND THEY SHOULD FAVOR COASTAL AS WELL AS SOUTHERN ZONES.
TEMPERATURES WILL BE FAIRLY CLOSE TO SEASONABLE NORMS IN WHAT SHOULD
BE A TREND TOWARDS DECREASING CLOUD COVER ALBEIT SOMEWHAT GRADUAL.
A CONTINUATION OF ALL OF THESE TRENDS HEADING INTO SATURDAY SHOULD
YIELD SOME PLEASANT WEATHER WITH AMPLE SUNSHINE AND A BIT OF A BOOST
TO THE WARMTH. WIND WILL REMAIN QUITE LIGHT AND OUT OF THE NORTH TO
NORTHEAST. THERE WILL BE JUST ENOUGH LINGERING MOISTURE ALONG MAYBE
THE SC COASTAL ZONES FOR A SPRINKLE OR TWO.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...A WEAKENING AND VERY NARROW RIDGE ALOFT UP AND
DOWN THE EAST COAST PAIRED WITH SURFACE HIGH PRESSURE TO OUR NORTH
ON SUNDAY SHOULD MEAN ONE LAST DAY WITHOUT MEANINGFUL RAIN CHANCES.
BY MONDAY THE DISTURBANCE THAT HAD BEEN OVER IOWA DURING THE SHORT
TERM PROGRESSES EASTWARD WHILE STRINGING SOUTH TO THE SOUTH. THIS
INDUCES A GRADUAL SOUTHWESTERLY FLOW INTO THE CAROLINAS WHILE THE
LOW LEVEL MOISTURE ASSOC WITH THE COLD FRONT WASHES NORTHWARD. LOOK
FOR A SOUTH-TO-NORTH INCREASE IN CLOUDINESS AND MINOR RAIN CHANCES.
SHOULD HIGH PRESSURE START WEDGING EAST OF THE APPALACHIANS AS
IMPLIED BY THE 00Z GFS AND THE (OLD) 12Z ECMWF THEN A STATIONARY
FRONT MAY DEVELOP ACROSS THE CAROLINAS AND THE LATE PERIOD/MID WEEK
MAY TURN QUITE RAINY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...IFR CIGS WILL BRIEFLY IMPROVE TO MVFR LATER THIS AFTN
BEFORE DROPPING BACK DOWN BELOW 1KFT TONIGHT. SURFACE OBS INDICATE
CIGS ARE GRADUALLY LIFTING...SO WOULD EXPECT TO START SEEING TAF
SITES IMPROVE TO MVFR BY 19-20Z. DEVELOPING LOW PRESSURE IS KEEPING
THE COASTAL TROUGH OFFSHORE...AND THUS HAVE REMOVED -RA FROM THE
TAFS. THE HRRR SHOWS LITTLE TO NO ADDITIONAL PCPN FOR THE TERMINALS
TODAY...EVEN ALONG THE COAST. NORTHEAST WINDS AOB 10 KT WILL PREVAIL
THROUGH THE DAY. THE WEDGE REASSERTS ITSELF TONIGHT AS HIGH PRESSURE
BUILDS SOUTHWARD AND THE GRADIENT TIGHTENS. EXPECT NORTHEAST WINDS
INCREASING TO 6-10 KT OVERNIGHT...WHICH SIGNIFICANTLY LOWERS THE FOG
THREAT AS COMPARED TO THIS MORNING. BUT IFR STRATUS WILL FILL BACK
IN AFTER MIDNIGHT AND PERSIST THROUGH MUCH OF FRI MORNING...WITH
LIFR CONDITIONS POSSIBLE IN THE PRE-DAWN HOURS.
EXTENDED OUTLOOK...MVFR/IFR CIGS POSSIBLE SAT MORNING. OTHERWISE VFR
SAT/SUN. CHANCE OF SHOWERS ON MON AND TUE.
MON.
&&
.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 2 PM THURSDAY...NORTHERLY FLOW WILL START INCREASING LATER
THIS AFTERNOON...EVENTUALLY REACHING 15 TO 20 KT...AS HIGH PRESSURE
BUILDING DOWN THE COAST STRENGTHENS. THE STRONGER HIGH WILL HELP
PUSH THE COASTAL TROUGH EAST OF THE WATERS OVERNIGHT. THIS WILL
SPREAD 15 TO 20 KT NORTHERLY FLOW OVER ALL ZONES. THE ENHANCED
NORTHERLY FLOW COULD PUSH SEAS IN SOME AREAS TO 5 FT...MAINLY IN THE
VICINITY OF FRYING PAN SHOALS AND EAST OF CAPE ROMAIN. AT THIS POINT
WILL NOT RAISE A SCEC FOR ANY ZONE...BUT SHOULD NORTHERLY SURGE END
UP A LITTLE STRONGER...EITHER DUE TO INCREASED STRENGTH OF SURFACE
HIGH OR MORE INTENSIFICATION OF WEAK LOW MOVING NORTH ALONG THE
TROUGH...SCEC HEADLINES MAY BE REQUIRED.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...A VERY WEAK COASTAL TROUGH WASHES OUT ON
FRIDAY ALLOWING FOR A BIT OF PENETRATION BY HIGH PRESSURE FURTHER
INTO THE CAROLINAS. RESULT LOCALLY IS A NORTHEASTERLY FLOW GENERALLY
IN THE 10 TO 15 KT RANGE. SEAS WILL RUN 3 TO 4 FT FOR THE MOST PART
SAVE FOR ABOUT A FOOT LOWER FOR AMZ254 DUE TO WAVE SHADOWING. TOUGH
TO RULE OUT THE STRAY 5 FT WAVE OUT ALONG FRYING PAN SHOALS BUT NOT
EXPECTING ANY CAUTIONARY HEADLINES. HIGH REMAINS ON SATURDAY WELL TO
OUR NORTH WHILE THE GRADIENT OFF THE COAST BECOMES A LITTLE POORLY
DEFINED. WIND MAY LIGHTEN AND VEER EVER SO SLIGHTLY ESPECIALLY LATE
IN THE DAY AS WELL AS HEADING INTO SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...NORTHEASTERLY GRADIENT WINDS TO WEAKEN ON
SUNDAY AS HIGH PRESSURE WELL TO THE NORTH PULLS BACK JUST A BIT
WHILE LOW PRESSURE DEVELOPS OVER THE MS VALLEY. THIS LOW WILL NEVER
DIRECTLY BE A PLAYER LOCALLY BUT ITS WARM ADVECTION ZONE MAY LEAD TO
A FRONT DEVELOPING ALONG THE SOUTHERN PERIPHERY OF THE
AFOREMENTIONED AREA OF HIGH PRESSURE. AS THIS BOUNDARY TRIES-BUT
LARGELY FAILS-TO ADVANCE NORTHWARD THE LOCAL FLOW MAY BACK FROM SE
TO A MORE EASTERLY/ONSHORE DIRECTION. THE TROUGHINESS ASSOCIATED
WITH THE FRONT MAY EAST THE GRADIENT TO WHERE WIND SPEEDS FALL TO
AROUND 10 KT. SEAS COULD RELAX TO JUST 2 FT ACROSS MOST OF THE
REGION LATE IN THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...III
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
348 AM EDT THU SEP 25 2014
.SYNOPSIS...LOW PRESSURE WILL LIFT UP THE MIDDLE ATLANTIC COAST
TODAY...BUT A WEDGE OF COOL AND DAMP HIGH PRESSURE WILL BE LEFT
BEHIND OVER OUR REGION THROUGH AT LEAST EARLY FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 325 AM THURSDAY...
SATELLITE AND SFC OBSERVATIONS REVEAL A LARGE AREA OF LOW CLOUDS
FROM VA TO FL...BANKED AGAINST THE APPALACHIANS...WITHIN A
PRONOUNCED CAD SFC RIDGE AXIS EXTENDING WSW FROM A PARENT 1035 MB
HIGH CENTERED SEVERAL HUNDRED MILES OFF THE NEW ENGLAND COAST. WHILE
A 1020 MB COASTAL LOW (A CAD EROSION SCENARIO) OFF THE VA CAPES WILL
CONTINUE TO LIFT NORTH ALONG THE MIDDLE ATLANTIC COAST...MOIST NNE
FLOW...TRAPPED BENEATH A LOW LEVEL INVERSION...WILL OTHERWISE FAVOR
A CONTINUED LOW OVERCAST AND ASSOCIATED COOL TEMPERATURES. LOW LEVEL
ISENTROPIC LIFT...WHICH WAS DRIVING PERIODS OF DRIZZLE AND BARELY
MEASURABLE LIGHT RAIN ACROSS CENTRAL NC THIS MORNING...IS FORECAST
TO SUBSIDE ACROSS ALL BUT THE FAR EASTERN SANDHILLS AND CENTRAL AND
SOUTHERN COASTAL PLAIN BETWEEN 12-15Z. THE LIGHT RAIN AND DRIZZLE
SHOULD DIMINISH BY NOON ACROSS ALL BUT THE FAR SE...WHERE BOTH LOW
LEVEL UPGLIDE AND A RENEWED SLUG OF MID LEVEL MOISTURE - IN THE
RIGHT ENTRANCE REGION OF A NEARLY STATIONARY UPPER JET AXIS - IS
FORECAST TO REMAIN. THERE...A SOLID CHANCE OF MEASURABLE RAIN WILL
CONTINUE THROUGHOUT THE DAY. PROJECTED LOW LEVEL THICKNESS VALUES
BETWEEN 1385-1395 METERS WITH WIDESPREAD LOW CLOUDS SUPPORTS HIGHS
ONLY IN THE MIDDLE 60S TO LOWER 70S.
TONIGHT: CONTIUED NE LOW LEVEL FLOW AROUND A 1026 MB SFC HIGH
FORECAST TO BECOME RE-ESTABLISHED OVER THE EASTERN GREAT
LAKES...BENEATH A BUILDING RIDGE ALOFT...WILL FAVOR CONTINUED LOW
OVERCAST. A SMALL DIURNAL TEMPERATURE RANGE WILL ALSO CONTINUE OWING
TO THE CAD...WITH LOWS IN THE UPPER 50S TO LOWER 60S.
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 345 AM THURSDAY...
1026-1028 MB SFC HIGH PRESSURE CENTERED OVER THE EASTERN GREAT LAKES
WILL CONTINUE TO RIDGE SOUTH...EAST OF THE APPALACHIANS...THROUGH
FRIDAY NIGHT. CLOUDY OR MOSTLY SO CONDITIONS WILL CONSEQUENTLY
CONTINUE THROUGH AT LEAST FRI EVENING...WITH ASSOCIATED CONTINUED
BELOW GUIDANCE TEMPERATURES - IN THE LOWER TO MIDDLE 70S. THERE ARE
INDICATIONS THAT THE NORTHEASTERLY FLOW WILL DRIVE AN AREA OF LOW
LEVEL DRYING SOUTH THROUGH VA LATE FRI AND INTO AT LEAST THE
NORTHERN PIEDMONT OF NC FRI NIGHT...WITH LINGERING LOW CLOUDS OVER
THE SOUTHERN HALF OF THE RAH CWFA THROUGH LATE FRI NIGHT. LOWS AGAIN
IN THE UPPER 50S TO LOWER 60S ON AVERAGE...THOUGH SOME LOWER TO
MIDDLE 50S WILL BE POSSIBLE TOWARD ROXBORO AND HENDERSON WHERE A
RELATIVE MINIMUM IN NE FLOW (CALM)...IN CLOSEST PROXIMITY TO THE SFC
RIDGE AXIS)...WOULD SUPPORT GOOD RADIATIONAL COOLING CONDITIONS IF
THE LOW LEVEL DRYING/CLEARING INDEED ARRIVES AS SCHEDULED.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...
HIGH PRESSURE RIDGE REMAINS OVER THE EAST COAST... WITH SURFACE HIGH
PRESSURE OVER THE EASTERN GREAT LAKES ON SATURDAY INTO SUNDAY. RIDGE
BEGINS TO BREAK DOWN MONDAY... AS A SHORTWAVE OVER THE MISSISSIPPI
VALLEY BEGINS TO MOVE EASTWARD... INCREASING OUR RAIN CHANCES BY
TUESDAY WITH THE POTENTIAL FOR THE DEVELOPMENT OF A COASTAL
TROUGH/LOW. WILL CONTINUE TO HOLD POPS AT CHANCE AT THIS POINT...
ALTHOUGH IF MODEL TRENDS CONTINUE TO LOCK IN ON THIS PATTERN...
LIKELY WOULD BE WARRANTED FOR TUESDAY. HIGH TEMPERATURES WILL BE
NEAR TO A FEW DEGREES BELOW NORMAL... WITH NEAR NORMAL LOWS THROUGH
THE PERIOD... IN PERSISTENT NORTHEASTERLY FLOW.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 225 AM THURSDAY...
IN A MATURE COLD AIR DAMMING REGIME OVER CENTRAL NC...LIFR-IFR
CONDITIONS THIS MORNING WILL ONLY SLOWLY IMPROVE TO IFR-MVFR THIS
AFTERNOON. WHILE THERE IS A SMALL CHANCE THAT LOW CLOUDS COULD LIFT
AND SCATTER TO VFR LATE THIS AFTERNOON AND EVENING...AS SUGGESTED BY
GFS BUFR SOUNDINGS...PAST EXPERIENCE AND NAM AND RAP BUFR SOUNDINGS
WOULD FAVOR CONTINUED SUB-VFR CONDITIONS THROUGHOUT THE TAF PERIOD.
IN FACT...ANY IMPROVEMENT TO IFR-MVFR THIS AFTERNOON AND EVENING
WILL LIKELY TREND BACK INTO THE LIFR-IFR RANGE WITH NOCTURNAL
COOLING - AMIDST CONTINUED NORTHEASTERLY FLOW - TONIGHT. THE
PRESENCE OF THE COLD AIR DAMMING SFC HIGH WILL ALSO RESULT IN
CONTINUED NORTHEASTERLY WINDS - STRONGEST IN THE 5-12 KT RANGE
THROUGH MIDDAY...THEN DIMINISHING TO BETWEEN 3-7 KTS THIS AFTERNOON
AND TONIGHT.
OUTLOOK: NORTHEASTERLY FLOW AROUND HIGH PRESSURE TO OUR NORTH WILL
MAINTAIN A GOOD CHANCE OF A SLOW LIFTING AND SCATTERING TO MVFR-VFR
EACH AFTERNOON...FOLLOWED BY THE RE-DEVELOPMENT OF LOW CLOUDS EACH
NIGHT. A LOW PRESSURE SYSTEM WILL BRING THE NEXT CHANCE OF
MEASURABLE RAIN (AFTER TODAY) ON MONDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...SEC
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
303 AM EDT THU SEP 25 2014
.SYNOPSIS...LOW PRESSURE WILL LIFT UP THE MIDDLE ATLANTIC COAST
TODAY...BUT A WEDGE OF COOL AND DAMP HIGH PRESSURE WILL BE LEFT
BEHIND OVER OUR REGION THROUGH AT LEAST EARLY FRIDAY.
&&
.NEAR TERM /TONIGHT THROUGH THURSDAY NIGHT/...
AS OF 1025 PM WEDNESDAY...
THROUGH TONIGHT...LIGHT RAIN CONTINUES ACROSS PORTIONS OF CENTRAL NC
THIS EVENING. UPPER AIR ANALYSES FROM 00Z SHOW THE LOW OVER WESTERN
NC AND HIGH PRESSURE OVER NEW ENGLAND. THE LOW WILL START TO LIFT
NORTHWARD OVERNIGHT...WHILE THE TROUGH LINGERS OVER THE CAROLINAS
AND VIRGINIA INTO THURSDAY. EXPECT LIGHT RAIN TO CONTINUE...MAINLY
ACROSS THE NORTH AND EAST...THROUGH THE OVERNIGHT HOURS. THE 00Z
SURFACE ANALYSIS SHOWS THE LOW OFF THE CAROLINA COAST...WITH THE
TROUGH EXTENDING SSW TO NNE ALONG THE COAST. BEST CHANCES FOR
CONVECTIVE SHOWERS WILL BE IN CLOSE PROXIMITY TO THE TROUGH...WHICH
SHOULD REMAIN ALONG THE COAST INTO THURSDAY WHILE THE LOW MOVES
NORTHWARD. GIVEN THE GOOD LOW TO MID LEVEL MOISTURE PRESENT...EXPECT
OVERCAST SKIES TO CONTINUE THROUGH THE OVERNIGHT PERIOD. AS A
RESULT...EXPECT LOWS TO ONLY DECREASE A DEGREE OR TWO FROM CURRENT
TEMPS...GENERALLY UPPER 50S NW TO MID 60S EAST EXPECTED. -KC
THURSDAY AND THURSDAY NIGHT...AS OF 305 PM WEDNESDAY...THURSDAY
WILL START OFF WITH WIDESPREAD LOW CLOUDS AND SOME MIST. A SHOWER IS
POSSIBLE IN THE MORNING...MAINLY ACROSS THE COASTAL PLAIN DRIVEN BY
A MID LEVEL WAVE SKIRTING THE CAROLINA COAST. THE NAM IS MORE
BULLISH WITH PRECIPITATION CHANCES ON THURSDAY THAN ITS PEERS WHICH
APPEARS TO DRIVEN BY ITS ENHANCED 925-850 MB SOUTHEAST FLOW. WILL
NOT BITE ON THIS FEATURE AT THIS TIME. NO WELL DEFINED COLD AIR
DAMMING EROSION MECHANISM WILL BE AROUND ON THURSDAY TO EFFICIENTLY
ERODE THE CAD. BUT THE STRENGTH OF THE CAD IS SOMEWHAT IN DOUBT...
ESPECIALLY ACROSS THE WESTERN PIEDMONT WHERE BOTH KGSO AND KINT ONLY
REPORTED 0.01 INCHES OF RAIN. FORESEE THE CAD BEING ERODED SLOWLY
AROUND ITS PERIPHERY BY INSOLATION BUT BEING MOST STUBBORN IN THE
NORTHEAST PIEDMONT IN THE RALEIGH-HENDERSON REGION. HIGHS TOMORROW
WILL BE PROBLEMATIC WITH A NORTHEAST WIND AND THE POTENTIAL FOR SOME
BREAKS OF SUNSHINE LATE. WILL UNDERCUT GUIDANCE GIVEN THE PATTERN
WITH HIGHS RANGING FROM THE MID 60S IN THE NORTHERN PIEDMONT TO
LOWER 70S AROUND THE PERIPHERY OF THE IN-SITU CAD WEDGE.
MOSTLY CLOUDY SKIES AND COOL CONDITIONS ARE EXPECTED ON THURSDAY
NIGHT. SOME SHOWERS WILL MOVE ACROSS THE COASTAL REGION BUT AT THIS
POINT THEY APPEAR AS THOUGH THEY WILL REMAIN EAST OF THE RAH CWA.
LOWS SHOULD RANGE IN THE UPPER 50S TO LOWER 60S. -BLAES
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 315 PM WEDNESDAY...
IN THE WAKE OF THE DEPARTING LOW PRESSURE SYSTEM...MID/UPPER LEVEL
HEIGHTS WILL BUILD ACROSS CENTRAL NC FRIDAY INTO SATURDAY. THIS IN
TURN WILL SUPPORT THE SOUTHWARD EXTENSION OF A DRY AIR SURFACE RIDGE
INTO THE CAROLINAS FROM A PARENT HIGH THAT WILL DRIFT EAST FROM THE
GREAT LAKES INTO SOUTHERN NEW ENGLAND. FRIDAY WILL START OUT
OVERCAST WITH SPOTTY DRIZZLE POSSIBLE...MAINLY SOUTH OF HIGHWAY 64.
THE ADVECTION OF DRIER AIR WORKING IN TANDEM WITH SUBSIDENCE
ASSOCIATED WITH THE RIDGING ALOFT WILL GRADUALLY EAT AWAY AT THE
CLOUD COVERAGE WITH PARTLY SUNNY SKIES EXPECTED ACROSS THE NORTH BY
EARLY AFTERNOON...AND EVENTUALLY TOWARD THE SOUTH CAROLINA BORDER
LATE IN THE DAY. EXPECT A LOT MORE SUN ON SATURDAY AS THE HIGH NEAR
THE SURFACE AND ALOFT WILL BE MORE FIRMLY IN CONTROL OF OUR WEATHER.
NOT FULLY CONFIDENT THAT SPOTTY DRIZZLE WILL OCCUR FRIDAY MORNING SO
WILL OMIT FROM FORECAST AT THIS TIME. SINCE DECREASING CLOUD TREND
WILL OCCUR NORTH-TO-SOUTH...SHOULD SEE A UNIFORM MAX TEMP FIELD FOR
FRIDAY. MAX TEMPS GENERALLY IN THE MID 70S.
POTENTIAL FOR AREAS OF FOG LATE FRIDAY NIGHT/EARLY SATURDAY ACROSS
THE SOUTH...ESPECIALLY IF CLOUDS DO NOT DEPART UNTIL CLOSE TO OR
AFTER SUNSET. MIN TEMPS UPPER 50S NORTH TO LOWER 60S SOUTH. A STEADY
NE SFC WIND COUPLED WITH MOSTLY SUNNYS SKIES SHOULD RESULT IN TEMPS
NEAR OR SLIGHTLY COOLER THAN AVERAGE FOR LATE SEPTEMBER. MAX TEMPS
LOW-MID 70S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...
HIGH PRESSURE RIDGE REMAINS OVER THE EAST COAST... WITH SURFACE HIGH
PRESSURE OVER THE EASTERN GREAT LAKES ON SATURDAY INTO SUNDAY. RIDGE
BEGINS TO BREAK DOWN MONDAY... AS A SHORTWAVE OVER THE MISSISSIPPI
VALLEY BEGINS TO MOVE EASTWARD... INCREASING OUR RAIN CHANCES BY
TUESDAY WITH THE POTENTIAL FOR THE DEVELOPMENT OF A COASTAL
TROUGH/LOW. WILL CONTINUE TO HOLD POPS AT CHANCE AT THIS POINT...
ALTHOUGH IF MODEL TRENDS CONTINUE TO LOCK IN ON THIS PATTERN...
LIKELY WOULD BE WARRANTED FOR TUESDAY. HIGH TEMPERATURES WILL BE
NEAR TO A FEW DEGREES BELOW NORMAL... WITH NEAR NORMAL LOWS THROUGH
THE PERIOD... IN PERSISTENT NORTHEASTERLY FLOW.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 225 AM THURSDAY...
IN A MATURE COLD AIR DAMMING REGIME OVER CENTRAL NC...LIFR-IFR
CONDITIONS THIS MORNING WILL ONLY SLOWLY IMPROVE TO IFR-MVFR THIS
AFTERNOON. WHILE THERE IS A SMALL CHANCE THAT LOW CLOUDS COULD LIFT
AND SCATTER TO VFR LATE THIS AFTERNOON AND EVENING...AS SUGGESTED BY
GFS BUFR SOUNDINGS...PAST EXPERIENCE AND NAM AND RAP BUFR SOUNDINGS
WOULD FAVOR CONTINUED SUB-VFR CONDITIONS THROUGHOUT THE TAF PERIOD.
IN FACT...ANY IMPROVEMENT TO IFR-MVFR THIS AFTERNOON AND EVENING
WILL LIKELY TREND BACK INTO THE LIFR-IFR RANGE WITH NOCTURNAL
COOLING - AMIDST CONTINUED NORTHEASTERLY FLOW - TONIGHT. THE
PRESENCE OF THE COLD AIR DAMMING SFC HIGH WILL ALSO RESULT IN
CONTINUED NORTHEASTERLY WINDS - STRONGEST IN THE 5-12 KT RANGE
THROUGH MIDDAY...THEN DIMINISHING TO BETWEEN 3-7 KTS THIS AFTERNOON
AND TONIGHT.
OUTLOOK: NORTHEASTERLY FLOW AROUND HIGH PRESSURE TO OUR NORTH WILL
MAINTAIN A GOOD CHANCE OF A SLOW LIFTING AND SCATTERING TO MVFR-VFR
EACH AFTERNOON...FOLLOWED BY THE RE-DEVELOPMENT OF LOW CLOUDS EACH
NIGHT. A LOW PRESSURE SYSTEM WILL BRING THE NEXT CHANCE OF
MEASURABLE RAIN (AFTER TODAY) ON MONDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...KC/BLAES
SHORT TERM...WSS
LONG TERM...SEC
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
229 AM EDT THU SEP 25 2014
.SYNOPSIS...LOW PRESSURE WILL LIFT UP THE MIDDLE ATLANTIC COAST
TODAY...BUT A WEDGE OF COOL AND DAMP HIGH PRESSURE WILL BE LEFT
BEHIND OVER OUR REGION THROUGH AT LEAST EARLY FRIDAY.
&&
.NEAR TERM /TONIGHT THROUGH THURSDAY NIGHT/...
AS OF 1025 PM WEDNESDAY...
THROUGH TONIGHT...LIGHT RAIN CONTINUES ACROSS PORTIONS OF CENTRAL NC
THIS EVENING. UPPER AIR ANALYSES FROM 00Z SHOW THE LOW OVER WESTERN
NC AND HIGH PRESSURE OVER NEW ENGLAND. THE LOW WILL START TO LIFT
NORTHWARD OVERNIGHT...WHILE THE TROUGH LINGERS OVER THE CAROLINAS
AND VIRGINIA INTO THURSDAY. EXPECT LIGHT RAIN TO CONTINUE...MAINLY
ACROSS THE NORTH AND EAST...THROUGH THE OVERNIGHT HOURS. THE 00Z
SURFACE ANALYSIS SHOWS THE LOW OFF THE CAROLINA COAST...WITH THE
TROUGH EXTENDING SSW TO NNE ALONG THE COAST. BEST CHANCES FOR
CONVECTIVE SHOWERS WILL BE IN CLOSE PROXIMITY TO THE TROUGH...WHICH
SHOULD REMAIN ALONG THE COAST INTO THURSDAY WHILE THE LOW MOVES
NORTHWARD. GIVEN THE GOOD LOW TO MID LEVEL MOISTURE PRESENT...EXPECT
OVERCAST SKIES TO CONTINUE THROUGH THE OVERNIGHT PERIOD. AS A
RESULT...EXPECT LOWS TO ONLY DECREASE A DEGREE OR TWO FROM CURRENT
TEMPS...GENERALLY UPPER 50S NW TO MID 60S EAST EXPECTED. -KC
THURSDAY AND THURSDAY NIGHT...AS OF 305 PM WEDNESDAY...THURSDAY
WILL START OFF WITH WIDESPREAD LOW CLOUDS AND SOME MIST. A SHOWER IS
POSSIBLE IN THE MORNING...MAINLY ACROSS THE COASTAL PLAIN DRIVEN BY
A MID LEVEL WAVE SKIRTING THE CAROLINA COAST. THE NAM IS MORE
BULLISH WITH PRECIPITATION CHANCES ON THURSDAY THAN ITS PEERS WHICH
APPEARS TO DRIVEN BY ITS ENHANCED 925-850 MB SOUTHEAST FLOW. WILL
NOT BITE ON THIS FEATURE AT THIS TIME. NO WELL DEFINED COLD AIR
DAMMING EROSION MECHANISM WILL BE AROUND ON THURSDAY TO EFFICIENTLY
ERODE THE CAD. BUT THE STRENGTH OF THE CAD IS SOMEWHAT IN DOUBT...
ESPECIALLY ACROSS THE WESTERN PIEDMONT WHERE BOTH KGSO AND KINT ONLY
REPORTED 0.01 INCHES OF RAIN. FORESEE THE CAD BEING ERODED SLOWLY
AROUND ITS PERIPHERY BY INSOLATION BUT BEING MOST STUBBORN IN THE
NORTHEAST PIEDMONT IN THE RALEIGH-HENDERSON REGION. HIGHS TOMORROW
WILL BE PROBLEMATIC WITH A NORTHEAST WIND AND THE POTENTIAL FOR SOME
BREAKS OF SUNSHINE LATE. WILL UNDERCUT GUIDANCE GIVEN THE PATTERN
WITH HIGHS RANGING FROM THE MID 60S IN THE NORTHERN PIEDMONT TO
LOWER 70S AROUND THE PERIPHERY OF THE IN-SITU CAD WEDGE.
MOSTLY CLOUDY SKIES AND COOL CONDITIONS ARE EXPECTED ON THURSDAY
NIGHT. SOME SHOWERS WILL MOVE ACROSS THE COASTAL REGION BUT AT THIS
POINT THEY APPEAR AS THOUGH THEY WILL REMAIN EAST OF THE RAH CWA.
LOWS SHOULD RANGE IN THE UPPER 50S TO LOWER 60S. -BLAES
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 315 PM WEDNESDAY...
IN THE WAKE OF THE DEPARTING LOW PRESSURE SYSTEM...MID/UPPER LEVEL
HEIGHTS WILL BUILD ACROSS CENTRAL NC FRIDAY INTO SATURDAY. THIS IN
TURN WILL SUPPORT THE SOUTHWARD EXTENSION OF A DRY AIR SURFACE RIDGE
INTO THE CAROLINAS FROM A PARENT HIGH THAT WILL DRIFT EAST FROM THE
GREAT LAKES INTO SOUTHERN NEW ENGLAND. FRIDAY WILL START OUT
OVERCAST WITH SPOTTY DRIZZLE POSSIBLE...MAINLY SOUTH OF HIGHWAY 64.
THE ADVECTION OF DRIER AIR WORKING IN TANDEM WITH SUBSIDENCE
ASSOCIATED WITH THE RIDGING ALOFT WILL GRADUALLY EAT AWAY AT THE
CLOUD COVERAGE WITH PARTLY SUNNY SKIES EXPECTED ACROSS THE NORTH BY
EARLY AFTERNOON...AND EVENTUALLY TOWARD THE SOUTH CAROLINA BORDER
LATE IN THE DAY. EXPECT A LOT MORE SUN ON SATURDAY AS THE HIGH NEAR
THE SURFACE AND ALOFT WILL BE MORE FIRMLY IN CONTROL OF OUR WEATHER.
NOT FULLY CONFIDENT THAT SPOTTY DRIZZLE WILL OCCUR FRIDAY MORNING SO
WILL OMIT FROM FORECAST AT THIS TIME. SINCE DECREASING CLOUD TREND
WILL OCCUR NORTH-TO-SOUTH...SHOULD SEE A UNIFORM MAX TEMP FIELD FOR
FRIDAY. MAX TEMPS GENERALLY IN THE MID 70S.
POTENTIAL FOR AREAS OF FOG LATE FRIDAY NIGHT/EARLY SATURDAY ACROSS
THE SOUTH...ESPECIALLY IF CLOUDS DO NOT DEPART UNTIL CLOSE TO OR
AFTER SUNSET. MIN TEMPS UPPER 50S NORTH TO LOWER 60S SOUTH. A STEADY
NE SFC WIND COUPLED WITH MOSTLY SUNNYS SKIES SHOULD RESULT IN TEMPS
NEAR OR SLIGHTLY COOLER THAN AVERAGE FOR LATE SEPTEMBER. MAX TEMPS
LOW-MID 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 315 PM WEDNESDAY...
SUNDAY INTO MONDAY...UPPER LEVEL RIDGE AND ATTENDANT SFC RIDGE
MAINTAINS ITS INFLUENCE FOR MOST OF SUNDAY. BY LATE SUNDAY INTO
MONDAY...THE UPPER LEVEL RIDGE BREAKS DOWN...CAUSING THE SURFACE
RIDGE TO ALSO WEAKEN AND DRIFT EAST. THIS WILL INITIATE A RETURN
FLOW IN RESPONSE TO AN AREA OF LOW PRESSURE EXITING THE LOWER MS
VALLEY INTO THE TN VALLEY. THIS FLOW WILL BEGIN A MOISTURE ADVECTION
REGIME...LEADING TO INCREASING/THICKENING CLOUD COVER SUNDAY NIGHT
INTO MONDAY. SUNDAY SHOULD BE THE WARMEST DAY IN THE EXTENDED UNDER
PARTLY-MOSTLY SUNNY SKIES. MAX TEMPS IN THE MID-UPPER 70S. MIN TEMPS
SUNDAY NIGHT UPPER 50S TO AROUND 60. INCREASING CLOUDS MONDAY WILL
LIMIT INSOLATION...LEADING TO SLIGHTLY COOLER TEMPS. MAX TEMPS
GENERALLY IN THE MID 70S. IF CLOUDS THICKER THAN ANTICIPATED...COULD
SEE MAX TEMPS 3-4 DEGREES COOLER...ESPECIALLY IN THE WEST.
WEATHER PATTERN MONDAY INTO TUESDAY LOOKS FAIRLY SIMILAR TO CURRENT
PATTERN. MODEL GUIDANCE GIVING A STRONG SIGNAL OF AN OVERRUNNING
SCENARIO (POTENTIAL HYBRID DAMMING EVENT). UNLIKE CURRENT
EVENT....MONDAY NIGHT-TUESDAY SCENARIO SUGGESTS BETTER POTENTIAL FOR
HEAVY RAIN OVER WESTERN SECTIONS OF NC IN A FAVORED UPSLOPE
ENVIRONMENT. MODEL MOS TEMP GUIDANCE HAS TRENDED COOLER AND HAVE
FOLLOWED SUIT. WOULD NOT BE SURPRISED IF MAX TEMPS END UP BEING 5-8
DEGREES COOLER THAN FORECAST....ESPECIALLY ACROSS THE PIEDMONT. PLAN
TO HAVE SOLID/HIGH CHANCE POPS FOR TUESDAY. IF MODEL TRENDS REMAIN
CONSISTENT...LIKELY/CATEGORICAL POPS WILL BE NECESSARY.
IMPROVING WEATHER PATTERN CURRENTLY ANTICIPATED FOR MID WEEK AS
MID/UPPER LEVEL LOW PRESSURE SYSTEM DEPARTS REGION THOUGH DRY AIR
ADVECTION LACKING AS RESIDUAL CAD HIGH REMAINS IN PLACE. MAX TEMPS
STILL SLIGHTLY COOLER THAN NORMAL. IF RESIDUAL CAD OCCURS...MAX
TEMPS IN THE PIEDMONT MAY END UP 4-6 DEGREES COOLER.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 225 AM THURSDAY...
IN A MATURE COLD AIR DAMMING REGIME OVER CENTRAL NC...LIFR-IFR
CONDITIONS THIS MORNING WILL ONLY SLOWLY IMPROVE TO IFR-MVFR THIS
AFTERNOON. WHILE THERE IS A SMALL CHANCE THAT LOW CLOUDS COULD LIFT
AND SCATTER TO VFR LATE THIS AFTERNOON AND EVENING...AS SUGGESTED BY
GFS BUFR SOUNDINGS...PAST EXPERIENCE AND NAM AND RAP BUFR SOUNDINGS
WOULD FAVOR CONTINUED SUB-VFR CONDITIONS THROUGHOUT THE TAF PERIOD.
IN FACT...ANY IMPROVEMENT TO IFR-MVFR THIS AFTERNOON AND EVENING
WILL LIKELY TREND BACK INTO THE LIFR-IFR RANGE WITH NOCTURNAL
COOLING - AMIDST CONTINUED NORTHEASTERLY FLOW - TONIGHT. THE
PRESENCE OF THE COLD AIR DAMMING SFC HIGH WILL ALSO RESULT IN
CONTINUED NORTHEASTERLY WINDS - STRONGEST IN THE 5-12 KT RANGE
THROUGH MIDDAY...THEN DIMINISHING TO BETWEEN 3-7 KTS THIS AFTERNOON
AND TONIGHT.
OUTLOOK: NORTHEASTERLY FLOW AROUND HIGH PRESSURE TO OUR NORTH WILL
MAINTAIN A GOOD CHANCE OF A SLOW LIFTING AND SCATTERING TO MVFR-VFR
EACH AFTERNOON...FOLLOWED BY THE RE-DEVELOPMENT OF LOW CLOUDS EACH
NIGHT. A LOW PRESSURE SYSTEM WILL BRING THE NEXT CHANCE OF
MEASURABLE RAIN (AFTER TODAY) ON MONDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...KC/BLAES
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1234 AM CDT THU SEP 25 2014
.UPDATE...
ISSUED AT 1235 AM CDT THU SEP 25 2014
PATCHY STRATUS AND FOG CONTINUED IN THE JAMES RIVER VALLEY...ON THE
WESTERN EDGE OF A LARGE AREA OF IFR/MVFR/VFR CLOUD SHIELD OVER MOST
OF MINNESOTA INTO THE RED RIVER VALLEY. HRRR MODEL INDICATES STRATUS
AND FOG SPREADING ACROSS THE JAMES RIVER BASIN THROUGH THE MORNING
HOURS...THUS KEPT MENTION OF FOG IN THROUGH MID MORNING. OTHERWISE
CURRENT FORECAST ON TRACK.
UPDATE ISSUED AT 938 PM CDT WED SEP 24 2014
A LITTLE PATCH OF STRATUS HAS MOVED THROUGH KJMS BUT BASED ON
SATELLITE TRENDS EXPECT THIS TO BE TRANSITORY. BUT AM CONCERNED
THE FOG WILL START EARLIER THERE (STUTSMAN/FOSTER) COUNTIES SO
ADDED FOG THERE. THEN EXPANDED NORTH AND SOUTH FROM THERE AFTER
05Z. OTHERWISE CURRENT FORECAST TRENDS OK.
UPDATE ISSUED AT 643 PM CDT WED SEP 24 2014
HIGH LEVEL CLOUDS ASSOCIATED WITH A POSITIVELY TILTED RIDGE AXIS
OVER WESTERN NORTH DAKOTA. LOW CLOUDS HAVE NEARLY CLEARED OUT OF
THE JAMES RIVER VALLEY THIS EVENING. WILL ADD SOME SKY COVER FOR
THE HIGH CLOUDS AS THEY APPEAR SOMEWHAT OPAQUE. HRRR MODEL HITS
THE JAMES RIVER VALLEY PRETTY GOOD WITH FOG AFTER 06Z SO RAISED
THE FOG THERE FROM PATCHY TO AREAS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 330 PM CDT WED SEP 24 2014
POTENTIALLY RECORD BREAKING WARMTH ON THURSDAY HIGHLIGHTS THE
SHORT TERM FORECAST.
STRATUS HAS CLEARED ALL OF WESTERN AND CENTRAL NORTH DAKOTA THIS
AFTERNOON EXCEPT FOR THE FAR SOUTHERN JAMES RIVER VALLEY...WHICH
IS EXPECTED BY 21-22 UTC. THE 15 UTC SREF CEILING PROBABILITIES
AND 19 UTC RAP LOW LEVEL RH FIELDS SUGGEST THE STRATUS WILL REMAIN
ACROSS THE RED RIVER VALLEY AND POINTS EAST TONIGHT. DID ADD A
PATCHY FOG MENTION TO THE JAMES RIVER VALLEY TONIGHT WHERE
RESIDUAL MID 50S DEWPOINTS WILL REMAIN.
FOR THURSDAY...ANOMALOUS 850 MB TEMPERATURES 2 STANDARD
DEVIATIONS ABOVE NORMAL ARE FORECAST UNDER THE BUILDING UPPER
LEVEL RIDGE. THIS SUPPORTS THE POTENTIAL FOR RECORD BREAKING
TEMPERATURES IN A WELL MIXED BOUNDARY LAYER.
LOCATION.........FORECAST HIGH........RECORD
BISMARCK.............90...............92 IN 1902
MINOT................89...............93 IN 1938
WILLISTON............93...............89 IN 2011
DICKINSON............91...............89 IN 1990
JAMESTOWN............85...............95 IN 1938
FOLLOWED THE WARMER EDGE OF THE 12 UTC GUIDANCE SUITE WHICH HAS
VERIFIED BEST THIS MONTH.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 PM CDT WED SEP 24 2014
THE TREND CONTINUES...WARM AND DRY THROUGH LATE WEEKEND.
THE RIDGE...CURRENTLY OVER EASTERN MONTANA...WILL NOSE INTO
WESTERN NORTH DAKOTA TOMORROW AND REMAIN OVER THE AREA THROUGH THE
EARLY PART OF THE WEEKEND. THIS WILL LEAD TO WARMER...POTENTIALLY
RECORD BREAKING...TEMPERATURES OVER THE NEXT COUPLE OF DAYS.
LATEST GUIDANCE CONTINUES TO SLOW DOWN THE PROGRESSION OF THE LONGWAVE
TROUGH OUT WEST. THE MAIN TROUGH AXIS ISN`T PROGGED TO SWING
THROUGH UNTIL SOMETIME TUESDAY. HOWEVER...A WARM FRONT IS FORECAST
TO SET UP ACROSS NORTHERN NORTH DAKOTA SUNDAY MORNING. THIS WILL
BE THE MAIN FOCUS FOR ANY PRECIPITATION SUNDAY INTO MONDAY. THE
MAIN WAVE AND ASSOCIATED COLD FRONT IS FORECAST TO ENTER WESTERN
NORTH DAKOTA MONDAY NIGHT. THE MODELS HAVE WAVERED BACK AND FORTH
OVER THE PREVIOUS RUNS. THERE ARE STILL DISCREPANCIES IN THE
TIMING AND LOCATION OF THE LOW TRACK...BUT IT STILL LOOKS LIKE AT
LEAST MOST OF THE AREA HAS A GOOD CHANCE AT SEEING SOME RAIN EARLY
NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1235 AM CDT THU SEP 25 2014
THE COMMS OUTAGE THAT WAS IMPACTING NORTHWESTERN NORTH DAKOTA
WEDNESDAY EVENING APPEARS TO BE OVER. THEREFORE KISN TAF WILL BE
ISSUED AND AMENDED AS NEEDED AS USUAL. OTHERWISE...PATCHY STRATUS
AND FOG IN THE JAMES VALLEY CONTINUED EARLY THIS MORNING. THUS KJMS
TAF REFLECTS DETERIORATING CIGS AND VSBYS THROUGH THE MORNING...THEN
BECOMING VFR BY AROUND 15Z. OTHERWISE VFR ALL TAF SITES WITH SOUTH
TO SOUTHEAST WINDS INCREASING BETWEEN 15Z-18Z WITH SOME GUSTS OVER
20 KNOTS POSSIBLE BETWEEN 18Z-00Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...JV
AREA FORECAST DISCUSSION
NWS PENDLETON OR
820 PM PDT FRI SEP 26 2014
.UPDATE...THE LARGE UPPER LEVEL TROUGH IS CONTINUING TO SPLIT WITH
CUT OFF LOW MOVING INTO NORTHERN CALIFORNIA TONIGHT. THERE IS A
BAND OF CIRRUS CLOUDS EXTENDING FROM THE LOW NORTH ACROSS EASTERN
OREGON...WHILE MOST OF THE CUMULUS CLOUDS FROM DAYTIME HEATING HAVE
DISSIPATED WITH PARTLY CLOUDY SKIES OVER THE REST OF THE REGION.
THERE WILL CONTINUE TO BE SLIGHT CHANCE OF SHOWERS ON SATURDAY ALONG
THE EAST SLOPES OF THE BLUE AND WALLOWA MOUNTAINS AS THE UPPER LEVEL
LOW MOVES INTO NEVADA WITH MOISTURE WRAPPING BACK AROUND THE LOW. I
ADJUSTED OVERNIGHT TEMPERATURES AND CLOUDS BASED ON CURRENT
CONDITIONS. ML
&&
.PREV DISC... /ISSUED 230 PM PDT FRI SEP 26 2014/
SHORT TERM...TONIGHT THROUGH MONDAY...A LARGE UPPER LEVEL TROUGH
HAS MOVED OVER THE PACIFIC NORTHWEST TODAY. A SPLIT FLOW IS
DEVELOPING IN THE TROUGH WITH A CLOSED LOW FORMING IN THE BASE OF
THE TROUGH IN NORTHERN CALIFORNIA AND ANOTHER LOW OVER THE CANADIAN
ROCKIES. THIS IS LEADING TO A WEST TO SOUTHWEST FLOW OVER THE AREA.
THE WESTERLY FLOW BROUGHT SHOWERS TO THE WASHINGTON CASCADE CREST
TODAY AND THAT SHOULD CONTINUE THIS EVENING THOUGH THE INTENSITY IS
LESSENING. ELSEWHERE SHOWERS HAVE BEEN SLOW TO DEVELOP AND HAVE CUT
BACK ON THE POPS FOR TONIGHT, LIMITING IT TO A SLIGHT CHANCE AND
REMOVING THEM FROM A FEW PLACES, MAINLY THE BLUE MOUNTAIN FOOTHILLS.
THE HRRR MODEL SHOWS A BAND OF SHOWERS DEVELOPING AFTER MIDNIGHT IN
SOUTHEAST OREGON AND PROGRESSING TO THE SOUTHERN EDGE OF OUR AREA SO
HAVE LEFT A SLIGHT CHANCE OF SHOWERS IN NORTHEAST OREGON WHILE THE
REST OF THE AREA DRIES OUT. ON SATURDAY THE SOUTHERN LOW WILL COME
ASHORE AND WILL BE CENTERED NEAR RENO IN THE AFTERNOON. IT WILL THEN
MOVE INTO CENTRAL NEVADA ON SUNDAY AND INTO UTAH AND WEAKEN BY
MONDAY. CIRCULATION AROUND THE LOW WILL BRING A NORTH TO NORTHEAST
WRAP AROUND FLOW INTO OUR AREA SATURDAY AND SUNDAY. THIS WILL LEAD
TO A SLIGHT CHANCE OF SHOWERS IN THE EASTERN OREGON MOUNTAINS MAINLY
IN THE AFTERNOON AND EVENING ON SATURDAY AND SUNDAY. BY MONDAY THE
FLOW WILL HAVE TURNED BACK TO WESTERLY AND ANOTHER SYSTEM WILL BE
APPROACHING THE COAST IN THE AFTERNOON WITH A SLIGHT CHANCE OF
SHOWERS DEVELOPING ALONG THE WASHINGTON CASCADE CREST WHILE A FEW
LINGERING SHOWERS WILL REMAIN OVER THE EASTERN OREGON MOUNTAINS.
TEMPERATURES WILL BE IN THE UPPER 60S TO MID 70S WITH 60S IN THE
MOUNTAINS WHILE LOWS WILL BE IN THE MID 40S TO MID 50S WITH MID 30S
TO MID 40S IN THE MOUNTAINS. PERRY
LONG TERM...MONDAY NIGHT THROUGH FRIDAY. A DISTURBANCE IS EXPECTED
TO PASS ACROSS THE REGION MONDAY NIGHT AND A FEW SHOWERS ARE
POSSIBLE ACROSS THE AREA MOUNTAINS. OTHERWISE A RETURN TO DRIER
CONDITIONS IS LIKELY TUESDAY AND WEDNESDAY AS A RIDGE OF HIGH
PRESSURE DRIFTS THROUGH THE AREA. ANOTHER WEAK DISTURBANCE IS
POSSIBLE THURSDAY THAT COULD INCREASE MID AND HIGH LEVEL CLOUDS
MAINLY ACROSS THE NORTHERN PARTS OF THE REGION ALONG WITH A FEW
SHOWERS ALONG THE EAST SLOPES OF THE WA CASCADES. BY FRIDAY A
STRONGER RIDGE OF HIGH PRESSURE IS EXPECTED WITH A SLIGHT WARMING
TREND EXPECTED TOWARD THE END OF THE WEEK.
AVIATION...MAINLY VFR CONDITIONS WILL PERSIST ACROSS THE AREA.
HOWEVER LCL MVFR CEILINGS...THAT MAY DIP TO 5000 FEET COULD OCCUR IN
AND NEAR SHOWERS UNTIL 18Z SATURDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 50 73 52 72 / 10 10 10 10
ALW 54 74 55 74 / 10 10 10 10
PSC 48 77 53 76 / 0 0 10 10
YKM 48 73 51 75 / 10 10 0 0
HRI 50 75 50 75 / 0 10 10 10
ELN 48 74 49 76 / 10 10 0 0
RDM 39 66 39 67 / 10 10 10 10
LGD 47 66 45 68 / 10 10 20 20
GCD 43 64 44 68 / 10 10 20 20
DLS 54 76 53 78 / 10 10 10 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
93/97/97
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
839 PM CDT FRI SEP 26 2014
.DISCUSSION...CURRENT FORECAST PACKAGE IN GOOD SHAPE WITH ONLY
MINOR CHANGES NEEDED THIS EVENING. PATTERN OVER THE REGION STILL
DOMINATED BY CLOSED UPPER LOW NEAR THE TX BIG BEND WHICH WILL
CONTINUE TO SPREAD MID/HIGH LEVEL MOISTURE NNEWD INTO SERN/CENTRAL
TX OVERNIGHT. HAVE BUMPED POPS A LITTLE TO ACCOUNT FOR A FEW STRAY
SHOWERS/TSTMS WHICH MAY MOVE INTO SOUTHERN/WESTERN COUNTIES LATE
TONIGHT. HOWEVER...EXPECT ANY ENSUING QPF TO REMAIN LIGHT.
OTHERWISE...FORECAST OVERNIGHT LOWS REMAIN ON TRACK WITH PARTLY TO
MOSTLY CLOUDY SKIES AND LIGHT ENE WINDS. 48
MARINE...
MODEST EASTERLY WINDS WILL PERSIST ACROSS THE COASTAL WATERS
THROUGH SATURDAY. WINDS AND WAVES ARE BORDER-LINE FOR SCA THIS
EVENING AT BUOY 19, SO WILL CERTAINLY CONTINUE EXERCISE CAUTION
WORDING INTO THE EARLY MORNING HOURS FOR THE OUTER WATERS. WINDS
WILL GRADUALLY WEAKEN AND BECOME MORE NORTHEASTERLY SUNDAY, WITH
LIGHT WINDS EXPECTED THROUGH THE FIRST HALF OF NEXT WEEK. RETURN
FLOW SETS UP ON WEDNESDAY IN RESPONSE TO A DEEPENING SURFACE LOW
ACROSS THE SOUTHERN PLAINS. 48
&&
.PREV DISCUSSION... /ISSUED 638 PM CDT FRI SEP 26 2014/
AVIATION...
VFR CONDITIONS MOSTLY EXPECTED FOR THE NEXT 24 HOURS W/ MAINLY
HIGH LEVEL CLOUDINESS MOVING OVERHEAD FROM THE WSW. ONE THING
WE`LL BE KEEPING AN EYE ON IN THE LATE EVENING HOURS IS FOR ANY
PROLONGED BREAKS IN THE CIGS WHICH MAY ALLOW FOR SOME SHALLOW
PATCHY FOG TO DEVELOP AT THE NON-METRO AIRPORTS. HRRR IS ALSO
DEPICTING A FEW WEAK SHRA EDGING FURTHER EWD AND INTO WRN HARRIS
CO JUST BEFORE DAYBREAK. WILL KEEP MENTION OF PRECIP OUT OF THE
00Z TAFS FOR NOW AS OVERALL CHANCES LOOK BETTER W & SW OF THE TAF
SITES OUT AND CLOSER TOWARD THE UPPER LOW CURRENTLY SITUATED OVER
THE BIG BEND REGION. 47
PREV DISCUSSION... /ISSUED 325 PM CDT FRI SEP 26 2014/
AREA RADAR SHOW SOME LIGHT SHOWERS ALONG THE COAST TOWARDS
MATAGORDA BAY WITH STRONGER RETURNS THROUGH THE RIO GRANDE VALLEY
TOWARDS BIG BEND. WATER VAPOR IMAGERY SHOWS PRONOUNCED UPPER LOW
OVER THE BIG BEND AREA WITH ANOTHER UPPER LOW OVER THE MIDWEST.
WATER VAPOR IMAGERY ALSO SHOWS THE NEXT UPSTREAM TROUGH DEVELOPING
OVER THE PAC COAST OF CALIFORNIA. GULF MOISTURE HAS PUSHED WEST
TOWARDS THE RIO GRANDE SUPPORT THE THUNDERSTORMS ACTIVITY THROUGH
S TX. OVERALL EXPECT THERE TO BE ONLY MINIMAL RAIN CHANCES TONIGHT
GOING INTO SATURDAY.
OVER THE WEEKEND FORECAST MODELS HAVE THE UPPER LOW OVER THE BIG
BEND MOVING EAST SHEARING OUT AS IT DOES. UPPER LOW TO THE WEST
MOVES TOWARDS THE GREAT BASIN WHICH ALLOWS FOR UPPER LEVEL RIDGING
TO BUILD OVER TX. THIS ALONG WITH SOMEWHAT DRIER MOISTURE PROFILES
WILL KEEP RAIN CHANCES AT A MINIMUM WITH A DRY FORECAST SUN GOING
INTO MON/TUE. MAX TEMPS SHOULD REACH UPPER 80S FOR THE BEGINNING
OF NEXT WEEK.
MEDIUM RANGE GFS/ECMWF/CANADIAN KEEP AN OVERALL MEAN TROUGH OVER
MUCH OF THE WESTERN U.S. BY MID WEEK. THIS ALLOWS FOR A WEAKER
RIDGE OVER TX BUT STILL SUPPORT ABOVE NORMAL TEMPS. THIS MEAN
TROUGH THEN DEEPENS OVER THE PLAINS THU/FRI. THE ECMWF IS NOW
DEEPER AND SLOWER WITH THE TROUGH THAN THE GFS. STILL THE NW FLOW
ALOFT ON THE BACK SIDE OF THE TROUGH WILL SUPPORT A FRONT PUSHING
INTO THE AREA LATE NEXT FRI. FORECAST WILL KEEP SOME 20/30 POPS
FOR THE END OF THE WEEK AS MOISTURE RETURNS AND THE FRONT IMPACTS
THE AREA. THE FRONT AT THIS POINT DOES NOT LOOK PARTICULARLY
STRONG BUT IF THE ECMWF SCENARIO DEVELOPS WITH THE DEEPER
TROUGH...COULD SEE TEMPS DROP MORE THAN FORECAST. FRONT COULD ALSO
MOVE INTO THE AREA FASTER THAN EXPECTED. BUT STILL HAVE A GOOD
SOLID WEEK TO WORK OUT THESE DETAILS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 87 68 87 67 89 / 20 10 20 10 10
HOUSTON (IAH) 86 69 87 68 88 / 20 20 20 10 10
GALVESTON (GLS) 85 75 85 75 85 / 20 20 30 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 1 AM CDT SATURDAY FOR
THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA
SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
638 PM CDT FRI SEP 26 2014
.AVIATION...
VFR CONDITIONS MOSTLY EXPECTED FOR THE NEXT 24 HOURS W/ MAINLY
HIGH LEVEL CLOUDINESS MOVING OVERHEAD FROM THE WSW. ONE THING
WE`LL BE KEEPING AN EYE ON IN THE LATE EVENING HOURS IS FOR ANY
PROLONGED BREAKS IN THE CIGS WHICH MAY ALLOW FOR SOME SHALLOW
PATCHY FOG TO DEVELOP AT THE NON-METRO AIRPORTS. HRRR IS ALSO
DEPICTING A FEW WEAK SHRA EDGING FURTHER EWD AND INTO WRN HARRIS
CO JUST BEFORE DAYBREAK. WILL KEEP MENTION OF PRECIP OUT OF THE
00Z TAFS FOR NOW AS OVERALL CHANCES LOOK BETTER W & SW OF THE TAF
SITES OUT AND CLOSER TOWARD THE UPPER LOW CURRENTLY SITUATED OVER
THE BIG BEND REGION. 47
&&
.PREV DISCUSSION... /ISSUED 325 PM CDT FRI SEP 26 2014/
AREA RADAR SHOW SOME LIGHT SHOWERS ALONG THE COAST TOWARDS
MATAGORDA BAY WITH STRONGER RETURNS THROUGH THE RIO GRANDE VALLEY
TOWARDS BIG BEND. WATER VAPOR IMAGERY SHOWS PRONOUNCED UPPER LOW
OVER THE BIG BEND AREA WITH ANOTHER UPPER LOW OVER THE MIDWEST.
WATER VAPOR IMAGERY ALSO SHOWS THE NEXT UPSTREAM TROUGH DEVELOPING
OVER THE PAC COAST OF CALIFORNIA. GULF MOISTURE HAS PUSHED WEST
TOWARDS THE RIO GRANDE SUPPORT THE THUNDERSTORMS ACTIVITY THROUGH
S TX. OVERALL EXPECT THERE TO BE ONLY MINIMAL RAIN CHANCES TONIGHT
GOING INTO SATURDAY.
OVER THE WEEKEND FORECAST MODELS HAVE THE UPPER LOW OVER THE BIG
BEND MOVING EAST SHEARING OUT AS IT DOES. UPPER LOW TO THE WEST
MOVES TOWARDS THE GREAT BASIN WHICH ALLOWS FOR UPPER LEVEL RIDGING
TO BUILD OVER TX. THIS ALONG WITH SOMEWHAT DRIER MOISTURE PROFILES
WILL KEEP RAIN CHANCES AT A MINIMUM WITH A DRY FORECAST SUN GOING
INTO MON/TUE. MAX TEMPS SHOULD REACH UPPER 80S FOR THE BEGINNING
OF NEXT WEEK.
MEDIUM RANGE GFS/ECMWF/CANADIAN KEEP AN OVERALL MEAN TROUGH OVER
MUCH OF THE WESTERN U.S. BY MID WEEK. THIS ALLOWS FOR A WEAKER
RIDGE OVER TX BUT STILL SUPPORT ABOVE NORMAL TEMPS. THIS MEAN
TROUGH THEN DEEPENS OVER THE PLAINS THU/FRI. THE ECMWF IS NOW
DEEPER AND SLOWER WITH THE TROUGH THAN THE GFS. STILL THE NW FLOW
ALOFT ON THE BACK SIDE OF THE TROUGH WILL SUPPORT A FRONT PUSHING
INTO THE AREA LATE NEXT FRI. FORECAST WILL KEEP SOME 20/30 POPS
FOR THE END OF THE WEEK AS MOISTURE RETURNS AND THE FRONT IMPACTS
THE AREA. THE FRONT AT THIS POINT DOES NOT LOOK PARTICULARLY
STRONG BUT IF THE ECMWF SCENARIO DEVELOPS WITH THE DEEPER
TROUGH...COULD SEE TEMPS DROP MORE THAN FORECAST. FRONT COULD ALSO
MOVE INTO THE AREA FASTER THAN EXPECTED. BUT STILL HAVE A GOOD
SOLID WEEK TO WORK OUT THESE DETAILS.
39
MARINE...
EASTERLY WINDS WILL PERSIST ACROSS THE COASTAL WATERS THROUGH
SATURDAY. WAVE HEIGHTS AT BUOY 19 HAVE COME DOWN SLIGHTLY SINCE
THIS MORNING BUT WILL CONTINUE THE SCEC FOR OFFSHORE WATERS
THROUGH TONIGHT. WINDS WILL BECOME NORTHEASTERLY AND WEAKEN ON
SUNDAY. EXPECT LIGHT WINDS THROUGH THE FIRST HALF OF NEXT WEEK
BEFORE RETURN FLOW SETS UP ON WEDNESDAY IN RESPONSE TO A DEEPENING
SURFACE LOW ACROSS THE SOUTHERN PLAINS. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 68 87 67 89 67 / 10 20 10 10 10
HOUSTON (IAH) 69 87 68 88 68 / 10 20 10 10 10
GALVESTON (GLS) 75 85 75 85 74 / 10 30 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 1 AM CDT SATURDAY FOR
THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA
SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
939 PM CDT FRI SEP 26 2014
.UPDATE...
PATCHY FOG IS DROPPING VSBYS AT KSBM...KRAC AND KENW...THOUGH WEB
CAMS SHOW IT IS NOT YET WIDESPREAD. CURRENT FORECAST HAS POTENTIAL
AREAS OF FOG WELL OUTLINED PER SREF VSBY PROBABILITY FORECAST AND
LATEST NAM VSBY PROG...AFFECTING THE LAKE SHORE COUNTIES AND
ADJACENT PORTIONS OF THE NEXT TIER OF COUNTIES TO THE WEST.
WILL KEEP AN EYE ON OBS AND SATELLITE FOG PRODUCT FOR ANY CHANGES
BUT PLAN TO HOLD ON TO CURRENT FORECAST...WITH SOME MINOR
TEMPS/DEW POINT TWEAKS.
&&
.AVIATION/06Z TAFS/...
PATCHY FOG BEGINNING TO DEVELOP IN THE EASTERN FORECAST AREA NEAR
LAKE MICHIGAN...WITH VSBYS DROPPING AT KSBM...KRAC AND KENW IN
GROUND FOG...WITH OTHER OBS AND WEB CAMS SHOWING FOG IS NOT
WIDESPREAD. EXPECT IFR CONDITIONS OVERNIGHT AT KENW...AND AT KMSN
FOR A FEW HOURS AROUND DAWN. OTHER TAF SITES EXPECTED TO GO NO
LOWER THAN MVFR. MOST FOG DISSIPATES BY 13Z-14Z SATURDAY...BUT MAY
BE SLOWER TO CLEAR NEAR THE LAKE. VFR CONDITIONS THROUGH THE
REMAINDER OF THE FORECAST...THOUGH AREAS OF FOG EXPECTED IN THE
EAST AGAIN LATE SATURDAY NIGHT WITH PATCHY FOG ELSEWHERE.
&&
.PREV DISCUSSION... /ISSUED 328 PM CDT FRI SEP 26 2014/
TONIGHT - CONFIDENCE...MEDIUM
SURFACE HIGH CONTINUES TO DOMINATE. BROAD 500 MILLIBAR CIRCULATION
ACRS NRN MO/SRN IA PROGGD TO RETROGRADE A BIT TO THE NORTHWEST. MAIN
CONCERN WILL BE FOG DEVELOPMENT. NOT MUCH CHANGE FROM LAST NIGHT
OTHER THAN SLIGHTLY HIGHER DEWPOINTS. ALSO NOTICING AN INCREASE IN
SE WINDS WITHIN A FEW OF THE LOWER GATES ON RAP SOUNDINGS. FOG WILL
BE QUITE SHALLOW AS COLUMN IS MOISTURE STARVED. NAM MOS A LITTLE
MORE ROBUST THAN THE GFS MOS BUT THIS IS TYPICAL. SREF PROBS NOT TOO
EXCITED BUT OVERALL PERSISTENCE SEEMS PRUDENT GIVEN THE OVERALL
STAGNANT PATTERN. WILL NOT HOIST AN ADVISORY AT THIS TIME AS
CONFIDENCE IN WIDESPREAD DENSE NOT HIGH AT THIS TIME...BUT POTENTIAL
THERE FOR AT LEAST PATCHY DENSE FOG.
SATURDAY - CONFIDENCE...HIGH
UPPER LOW PROGGD TO BE AROUND NW IA/SW MN. HIGH PRESSURE RIDGE
DOMINATES WITH THE DRY AND STABLE AIRMASS PERSISTING. MORNING FOG
TRENDS WILL BE THE MAIN FOCUS WITH ANY LINGERING FOG LIKELY TO BURN
OFF IN MUCH THE SAME FASHION AS FRIDAY MORNING. 925 TEMPS AROUND 17-
18C...SO HIGHS WELL INTO THE 70S.
SATURDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE - MEDIUM.
MORE FOG POSSIBLE SATURDAY NIGHT AS BOUNDARY LAYER WINDS REMAIN
AROUND 10 KNOTS OR LESS. SFC DEWPTS CONTINUE TO SLOWLY RISE EACH
DAY DUE TO THE STAGNATING AIR MASS. HENCE THE LIGHT WINDS AND
MOSTLY CLEAR SKIES SHOULD ALLOW OVERNIGHT TEMPS TO FALL BELOW THE
DAYTIME CROSS OVER TEMP ONCE AGAIN.
OTHERWISE...THE QUIET CONDITIONS WILL CONTINUE THROUGH MONDAY
MORNING. MOST OF THE SHORT TERM GUIDANCE SHOWING AN AMPLIFYING
SHORT WAVE TROUGH FURTHER STRENGTHENING ALONG BAROCLINIC ZONE DRAPED
ACROSS NORTHERN GTLAKES SUN NGT AND MON. THIS HIGHER AMPLITUDE WAVE
AND LOW PRESSURE RESULTS IN QUICKER SOUTHWARD MOVEMENT OF BACKDOOR
COLD FRONT ACROSS WESTERN GTLAKES ON MONDAY. ELEVATED MOISTURE
STILL LIMITED AS FRONT CROSSES REGION SO FOR NOW...WL CONTINUE SCHC
WORDING IN THE NORTHEAST CWA...CLOSER TO UPPER LEVEL CIRCULATION.
LATER PERIODS OF NAM REMAIN OUTLIER WITH ITS SLOWER SWD MOVEMENT.
IF THIS TREND CONTINUES WL NEED TO BUMP UP WINDS AND SPEED UP MORE
ABRUPT WIND CHANGE LATER MONDAY INTO MONDAY EVENING.
MONDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE - MEDIUM TRENDING
TOWARD LOW.
AS MENTIONED ABOVE...MEDIUM RANGE GUIDANCE IN GOOD AGREEMENT ON
AMPLIFYING SHORT WAVE TROUGH OVER WESTERN GTLAKES CONTINUING TO
STRENGTHEN AS IT TRACKS EWD MONDAY AND MONDAY NIGHT. STRONGER SHORT
WAVE WILL PULL BACKDOOR CDFNT SWD ACROSS SRN WI ABOUT 12 HOURS
EARLIER THAN THOUGHT 24 HOURS AGO. HENCE CDFNT NOW EXPECTED TO
ADVANCE SOUTH OF SRN WI/LAKE MI BY 00Z/TUE. WL KEEP A CHANCE FOR -
SHRA IN THE EVE IN PARTS OF EAST BUT DRIER...COOLER AIR WILL END
THREAT OVERNIGHT. LIKELY SOME LOW CLOUDS/STRATUS WL ACCOMPANY PUSH
OF COLDER AIR POST FRONTAL PASSAGE.
SHORT WAVE RIDGING SHOULD RESULT IN QUIET AND DRY CONDITIONS
RETURNING AT LEAST TEMPORARILY TUE/TUE NGT.
MEANWHILE...BROADENING LONG WAVE TROUGH OVER WRN CONUS WILL RESULT
IN INCREASING SLY WINDS OVER THE WRN GTLAKES AROUND MID WEEK AS
SEVERAL PIECES OF SHORT WAVE ENERGY ROTATE NORTHWARD ACROSS THE
NORTHERN PLAINS/UPPER MIDWEST. AS A RESULT...COLUMN PRECIPITABLE
WATER INCREASES TO AROUND 1.5 INCHES BY 00Z/THU. INITIAL SURGE OF
MOISTURE MAY SET OFF PRECIPITATION ON WED...WITH BETTER CHANCE IN
THU/THU NGT TIME FRAME WHEN STRONG CDFNT AND SHARP MID-LEVEL SHORT
WAVE PASS ACROSS THE REGION. 00Z MEDIUM RANGE GUIDANCE RAPIDLY
DIVERGED AFTER THAT AS GFS CONTINUED TO CARVE OUT COLD LONG WAVE
TROUGH OVER THE REGION...WHILE ECMWF RETURNS TO WARMER...MORE ZONAL
FLOW FOR THE WEEKEND. HOWEVER 12Z ECMWF/GFS FLIP FLOPPED SOMEWHAT
WITH ECMWF NOW SHOWING COLD AIR SURGING INTO SRN WI FOR THE
WEEKEND...WHILE GFS TRENDS TOWARD MORE ZONAL FLOW. HENCE LOW
CONFIDENCE IN LATE PERIODS
DISAGREEMENT BEGINS UPSTREAM OVER WRN CONUS AND NORTHERN PACIFIC WRT
AMOUNT OF AMPLIFICATION OF NORTHERN PACIFIC TROF AND RIDGING OVER
WRN CONUS. GFS ENSEMBLE MEMBERS SHOWING LARGE VARIABILITY IN UPPER
LEVEL FEATURES DURING THIS PERIOD...SO WOULD OPT FOR AN AVERAGE OF
ALL GUIDANCE FOR NEXT WEEKEND.
AVIATION/00Z TAFS/...MOSTLY VFR PERIOD WITH SURFACE HIGH HAVING
STRONG INFLUENCE WITH DRY AND STABLE AIRMASS. WATER VAPOR/RAP SHOWS
RATHER BROAD CIRCULATION CENTER VCNTY NW MO/SE IA. WILL WATCH FOR
MORE FOG DEVELOPMENT TONIGHT WITH SOME IFR VSBYS POSSIBLE. ANY FOG
WILL DISSIPATE SATURDAY MORNING AS HEATING KICKS IN.
MARINE...FOG WILL LIKELY DEVELOP ONCE AGAIN OVER EASTERN WI THIS
EVENING AND OVERNIGHT AND SOME OF THIS FOG MAY DEVELOP OVER THE
NEARSHORE WATERS AS WELL.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...REM
TONIGHT/SATURDAY AND AVIATION/MARINE...COLLAR
SATURDAY NIGHT THROUGH FRIDAY...MBK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
442 AM EDT SAT SEP 27 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM EDT SAT SEP 27 2014
...ANOTHER UNSEASONABLY WARM LATE SEPT DAY IS ON THE WAY TODAY...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A STRONG RIDGE OVER MUCH
OF THE E HALF OF THE CONUS. CORE OF THE POSITIVE ANOMALIES WITH THE
RIDGE IS OVER NRN ONTARIO WHERE ANOMALIES ARE 2.5 STANDARD
DEVIATIONS ABOVE THE LONG TERM LATE SEPT AVG. WITHIN THE RIDGE...A
WEAK MID LEVEL LOW CENTERED ROUGHLY ALONG THE IA/MO BORDER IS
GENERATING ISOLD SHRA/TSRA OVER IA INTO SW MN. CLOSER TO HOME...THE
WEATHER REMAINS QUIET. TYPICAL FOR THIS TIME OF YEAR WITH THIS TYPE
OF WEATHER PATTERN THAT FEATURES QUIET/CLEAR NIGHTS...SHALLOW FOG
HAS AGAIN FORMED...MAINLY OVER SCNTRL AND ERN UPPER MI AND
ESPECIALLY NEAR RIVERS/LAKES/STREAMS.
WITH LITTLE OVERALL CHANGE IN AIR MASS TODAY COMPARED TO YESTEDAY...
TODAY WILL BE A CARBON COPY OF YESTERDAYS WEATHER. MIXING TO
AROUND 850MB SUPPORTS MAX TEMPS WELL INTO THE 70S TO THE LWR 80S
AWAY FROM LAKE MODERATION WHICH SHOULD BE CONFINED MAINLY TO AREAS
NEAR LAKE MICHIGAN. GIVEN THE SIMILAR AIR MASS CHARACTERISTICS...
SIMPLY USED YESTERDAYS OBSERVED MAX TEMPS FOR TODAYS FCST WITH A FEW
MINOR ADJUSTMENTS. DIURNAL TEMP RISE SHOULD BE NEARLY IDENTICAL TO
YESTERDAYS AS WELL...SO UTILIZED YESTERDAYS DIURNAL TEMP CURVE FOR
HOURLY TEMPS. SHALLOW FOG WILL QUICKLY DISSIPATE AFTER SUNRISE.
ANOTHER QUIET/CLEAR NIGHT IS EXPECTED TONIGHT. MIN TEMPS SHOULD BE A
LITTLE HIGHER THAN THIS MORNINGS MINS DUE TO SOME INCREASE IN
PRECIPITABLE WATER. SHALLOW FOG SHOULD MAKE ANOTHER APPEARANCE IN
GENERALLY THE SAME AREAS THAT IT HAS APPEARED IN RECENT NIGHTS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 354 AM EDT SAT SEP 27 2014
GOOD AGREEMENT IN OVERALL LOOK OF LARGER SCALE PATTERN INTO NEXT
WEEK. MAIN ISSUE REMAINS TIMING OF FRONT ON SUNDAY NIGHT INTO
MONDAY. ECMWF HAS STEADILY TRENDED TOWARD QUICKER FROPA ON SUNDAY
NIGHT WITH NNE WINDS OVER ALL OF UPR MICHIGAN BY 12Z MONDAY. NAM AND
GFS NOT AS AGGRESSIVE AND TREND FROM GFS IS MAINLY SLOWER...THOUGH
00Z RUN IS FARTHER SOUTH WITH FRONT BUT KEEPS MOST RAIN OUT OF CWA
UNTIL AFTER 12Z MONDAY. DIFFERENCES IN TIMING OF FROPA IS TIED TO
HOW MUCH JET ENERGY DIGS INTO BACKSIDE OF SHORTWAVE TROUGH CROSSING
NORTHERN ONTARIO. ECMWF SHOWS STRONGER JET/MORE AMPLFIED TROUGH
WHILE GFS AND GEM-NH SHOW MORE OF THE JET ENERGY AHEAD OF THE TROUGH
AND THUS A FLATTER MORE PROGRESSIVE TROUGH ALOFT. TOUGH TO SAY WHICH
IDEA IS RIGHT. MORE AMPLIED IDEA SEEMS GOOD AS MAIN SHORTWAVE
CURRENTLY OVER NORTHERN ALBERTA IS QUITE SHARP PER WV LOOP AND 00Z
RAOBS...BUT A MORE STRUNG OUT SHORTWAVE COULD ALSO OCCUR AS THE
RIDGE IT WILL BE DROPPING TOWARDS IS UNSEASONABLY STRONG WITH
590DAM HEIGHTS FM DAKOTAS OVER NORTHERN ONTARIO AND OVER SOUTHERN
QUEBEC AND LOWER GREAT LAKES.
CONSENSUS OF ALL MODELS AND THE CURRENT FORECAST POINTS TO FROPA LATE
SUNDAY NIGHT INTO MONDAY MORNING. WILL HEAD THIS WAY AS WELL. RESULT
WILL BE INCREASING RAIN CHANCES INTO MONDAY...LIKELY TURNING INTO
MORE OF A STRATIFORM RAIN BOOSTED BY H7-H5 Q-VECTOR CONVERGENCE WITH
THE SHORTWAVE AND ADDITIONAL LIFT WITHIN RIGHT ENTRANCE REGION OF JET
STREAK FM NORTHERN ONTARIO TO QUEBEC. SHALLOW COOL/MOIST FLOW
UPSLOPING INTO HIGHER TERRAIN NEAR LK SUPERIOR ONLY ADDS TO THE RAIN
CHANCES. TEMPS WILL EXHIBIT SHARP GRADIENT BTWN WHERE THE SUB H9 FLOW
IS STIFF ONSHORE AND WHERE MIXING TO H9 AND OFFSHORE WINDS WILL ALLOW
FOR TEMPS TO REACH NEAR 70 OVER THE SCNTRL. RAIN SHOULD DIMINISH TO
PROBABLY AREAS OF DRIZZLE LATER MONDAY NIGHT AS HIGH
PRESSURE/ANTICYCLONIC FLOW ADVANCES FURTHER INTO THE AREA. COOL TEMPS
PERSIST INTO TUESDAY...ESPECIALLY NEAR LK SUPERIOR WHERE WINDS STAY
ONSHORE ALL DAY.
RIDGING BUILDS BACK ALOFT BY WEDNESDAY AS TROUGHING EXPANDS OVER
WESTERN CONUS. WEDNESDAY WILL BE AN IN BTWN DAY AND COULD SEE AT
LEAST SOME SUNSHINE...AT LEAST IN THE EAST HALF. HIGH TEMPS WARMING
BACK INTO THE 60S AND POSSIBLY...WITH ENOUGH SUNSHINE...TOUCHING 70
DEGREES. LEADING SHORTWAVE EMERGING FM WEST CONUS TROUGH COULD BRING
SOME SHOWERS TO PARTS OF CWA BY WEDNESDAY EVENING. GREATEST CHANCES
OF RAIN LIKELY HOLD OFF TIL THURSDAY AS STRONGER FORCING ALOFT
COMBINES WITH MORE OF A LOW-LEVEL FRONTAL BOUNDARY. MODEL CONSISTENCY
IS SHAKY SO WILL NOT ALTER THE CONSENSUS POPS. INCLUDED SMALL CHANCES
FOR THUNDER ON THURSDAY AS THERE IS AT LEAST A BRIEF INTERLUDE OF
INSTABILITY WORKING ACROSS THE REGION AHEAD OF THE FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 110 AM EDT SAT SEP 27 2014
PLENTY OF DRY AIR ASSOCIATED WITH HI PRES CENTERED NEAR LK HURON
WILL BRING PREDOMINANT VFR CONDITIONS AT ALL 3 SITES THIS FCST
PERIOD. FOG...WITH POSSIBLE IFR VSBYS...IS POSSIBLE AT SAW TOWARD
SUNRISE. A BIT STRONGER SSW FLOW WILL LIMIT THE POTENTIAL FOR FOG AT
CMX AND IWD. GUSTY SSW WINDS WILL DVLP AT IWD AND PERHAPS SAW IN THE
AFTN WITH SOME DAYTIME HEATING/MIXING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 AM EDT SAT SEP 27 2014
LIGHT WINDS PERSIST THROUGH SUNDAY...THEN CHANGES ARE EXPECTED BY
MONDAY MORNING AS A FRONT WORKS NORTH TO SOUTH ACROSS LK SUPERIOR.
EXPECT WINDS TO SHIFT TO THE NORTHEAST AND QUICKLY RAMP UP TO 25-30
KTS AFTER MIDNIGHT SUNDAY NIGHT WITH STRONGER WINDS CONTINUING INTO
MIDDAY MONDAY. WINDS WILL DIMINISH MONDAY NIGHT INTO TUESDAY AS HIGH
PRESSURE SETTLES OVERHEAD. SOUTHEAST TO SOUTH WINDS INCREASE
WEDNESDAY INTO THURSDAY AHEAD OF THE NEXT LOW PRESSURE SYSTEM. WINDS
WILL BE STRONGEST OVER EASTERN HALF OF LK SUPERIOR.
WITH MORE MOIST AIR BEGINNING TO WORK NORTH OVER LAKE SUPERIOR...
THERE IS THE POTENTIAL FOR PATCHY/AREAS OF FOG OVER MAINLY NORTHERN
PORTIONS OF LAKE SUPERIOR LATER TONIGHT THROUGH SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...KC
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
357 AM EDT SAT SEP 27 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 356 PM EDT FRI SEP 26 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH NEAR
THE WEST COAST AND A PROMINENT RIDGE ACROSS THE PLAINS INTO NRN
ONTARIO. AT THE SFC...WEAK SRLY FLOW WAS OBSERVED THROUGH WI AND
UPPER MI BETWEEN HIGH PRES OVER LAKE HURON AND A TROUGH THROUGH THE
WRN PLAINS. VIS LOOP INDICATED SCT CU UPSTREAM OVER THE UPPER MS
VALLEY AS LOW LEVEL MOISTURE INCREASES. OTHERWISE...COMPLETELY CLEAR
SKIES PREVAILED ACROSS UPPER MICHIGAN. DEWPOINTS WERE GENERALLY IN
THE LOWER 50S...WITH SOME HIGHER VALUES IN THE MID 50S OVER THE EAST
DOWNWIND OF LAKE MICHIGAN.
TONIGHT...WITH THE UPPER AND SFC RIDGE NEARLY STATIONARY OVER THE
AREA...EXPECT FOG TO REDEVELOP IN AREAS SIMILAR TO THU NIGHT...WITH
THE LOWEST VISIBILITIES OVER THE CNTRAL AND EAST AND ESPECIALLY
NEAR LAKE MICHIGAN.
SAT...A MID LEVEL TROUGH AND ASSOCIATED SFC LOW WILL MOVE THROUGH
FAR NRN ONTARIO TO SRN HUDSON BAY DRAGGING A COLD FRONT TO NEAR
CYPL. SRLY FLOW AHEAD OF FRONT WILL KEEP THE WARM AIR ACROSS THE
CWA. AFTER ANY MORNING FOG BURNS OFF...SUNNY SKIES WILL AGAIN
DOMINATE THE AREA. FCST SOUNDINGS SUGGEST THAT MIXING TO AROUND 850
MB (TEMPS AROUND 14C) WILL SUPPORT MAX READINGS INT THE UPPER 70S TO
NEAR 80.
&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 354 AM EDT SAT SEP 27 2014
GOOD AGREEMENT IN OVERALL LOOK OF LARGER SCALE PATTERN INTO NEXT
WEEK. MAIN ISSUE REMAINS TIMING OF FRONT ON SUNDAY NIGHT INTO
MONDAY. ECMWF HAS STEADILY TRENDED TOWARD QUICKER FROPA ON SUNDAY
NIGHT WITH NNE WINDS OVER ALL OF UPR MICHIGAN BY 12Z MONDAY. NAM AND
GFS NOT AS AGGRESSIVE AND TREND FROM GFS IS MAINLY SLOWER...THOUGH
00Z RUN IS FARTHER SOUTH WITH FRONT BUT KEEPS MOST RAIN OUT OF CWA
UNTIL AFTER 12Z MONDAY. DIFFERENCES IN TIMING OF FROPA IS TIED TO
HOW MUCH JET ENERGY DIGS INTO BACKSIDE OF SHORTWAVE TROUGH CROSSING
NORTHERN ONTARIO. ECMWF SHOWS STRONGER JET/MORE AMPLFIED TROUGH
WHILE GFS AND GEM-NH SHOW MORE OF THE JET ENERGY AHEAD OF THE TROUGH
AND THUS A FLATTER MORE PROGRESSIVE TROUGH ALOFT. TOUGH TO SAY WHICH
IDEA IS RIGHT. MORE AMPLIED IDEA SEEMS GOOD AS MAIN SHORTWAVE
CURRENTLY OVER NORTHERN ALBERTA IS QUITE SHARP PER WV LOOP AND 00Z
RAOBS...BUT A MORE STRUNG OUT SHORTWAVE COULD ALSO OCCUR AS THE
RIDGE IT WILL BE DROPPING TOWARDS IS UNSEASONABLY STRONG WITH
590DAM HEIGHTS FM DAKOTAS OVER NORTHERN ONTARIO AND OVER SOUTHERN
QUEBEC AND LOWER GREAT LAKES.
CONSENSUS OF ALL MODELS AND THE CURRENT FORECAST POINTS TO FROPA LATE
SUNDAY NIGHT INTO MONDAY MORNING. WILL HEAD THIS WAY AS WELL. RESULT
WILL BE INCREASING RAIN CHANCES INTO MONDAY...LIKELY TURNING INTO
MORE OF A STRATIFORM RAIN BOOSTED BY H7-H5 Q-VECTOR CONVERGENCE WITH
THE SHORTWAVE AND ADDITIONAL LIFT WITHIN RIGHT ENTRANCE REGION OF JET
STREAK FM NORTHERN ONTARIO TO QUEBEC. SHALLOW COOL/MOIST FLOW
UPSLOPING INTO HIGHER TERRAIN NEAR LK SUPERIOR ONLY ADDS TO THE RAIN
CHANCES. TEMPS WILL EXHIBIT SHARP GRADIENT BTWN WHERE THE SUB H9 FLOW
IS STIFF ONSHORE AND WHERE MIXING TO H9 AND OFFSHORE WINDS WILL ALLOW
FOR TEMPS TO REACH NEAR 70 OVER THE SCNTRL. RAIN SHOULD DIMINISH TO
PROBABLY AREAS OF DRIZZLE LATER MONDAY NIGHT AS HIGH
PRESSURE/ANTICYCLONIC FLOW ADVANCES FURTHER INTO THE AREA. COOL TEMPS
PERSIST INTO TUESDAY...ESPECIALLY NEAR LK SUPERIOR WHERE WINDS STAY
ONSHORE ALL DAY.
RIDGING BUILDS BACK ALOFT BY WEDNESDAY AS TROUGHING EXPANDS OVER
WESTERN CONUS. WEDNESDAY WILL BE AN IN BTWN DAY AND COULD SEE AT
LEAST SOME SUNSHINE...AT LEAST IN THE EAST HALF. HIGH TEMPS WARMING
BACK INTO THE 60S AND POSSIBLY...WITH ENOUGH SUNSHINE...TOUCHING 70
DEGREES. LEADING SHORTWAVE EMERGING FM WEST CONUS TROUGH COULD BRING
SOME SHOWERS TO PARTS OF CWA BY WEDNESDAY EVENING. GREATEST CHANCES
OF RAIN LIKELY HOLD OFF TIL THURSDAY AS STRONGER FORCING ALOFT
COMBINES WITH MORE OF A LOW-LEVEL FRONTAL BOUNDARY. MODEL CONSISTENCY
IS SHAKY SO WILL NOT ALTER THE CONSENSUS POPS. INCLUDED SMALL CHANCES
FOR THUNDER ON THURSDAY AS THERE IS AT LEAST A BRIEF INTERLUDE OF
INSTABILITY WORKING ACROSS THE REGION AHEAD OF THE FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 110 AM EDT SAT SEP 27 2014
PLENTY OF DRY AIR ASSOCIATED WITH HI PRES CENTERED NEAR LK HURON
WILL BRING PREDOMINANT VFR CONDITIONS AT ALL 3 SITES THIS FCST
PERIOD. FOG...WITH POSSIBLE IFR VSBYS...IS POSSIBLE AT SAW TOWARD
SUNRISE. A BIT STRONGER SSW FLOW WILL LIMIT THE POTENTIAL FOR FOG AT
CMX AND IWD. GUSTY SSW WINDS WILL DVLP AT IWD AND PERHAPS SAW IN THE
AFTN WITH SOME DAYTIME HEATING/MIXING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 AM EDT SAT SEP 27 2014
LIGHT WINDS PERSIST THROUGH SUNDAY...THEN CHANGES ARE EXPECTED BY
MONDAY MORNING AS A FRONT WORKS NORTH TO SOUTH ACROSS LK SUPERIOR.
EXPECT WINDS TO SHIFT TO THE NORTHEAST AND QUICKLY RAMP UP TO 25-30
KTS AFTER MIDNIGHT SUNDAY NIGHT WITH STRONGER WINDS CONTINUING INTO
MIDDAY MONDAY. WINDS WILL DIMINISH MONDAY NIGHT INTO TUESDAY AS HIGH
PRESSURE SETTLES OVERHEAD. SOUTHEAST TO SOUTH WINDS INCREASE
WEDNESDAY
INTO THURSDAY AHEAD OF THE NEXT LOW PRESSURE SYSTEM. WINDS WILL BE
STRONGEST OVER EASTERN HALF OF LK SUPERIOR.
WITH MORE MOIST AIR BEGINNING TO WORK NORTH OVER LAKE SUPERIOR...
THERE IS THE POTENTIAL FOR PATCHY/AREAS OF FOG OVER MAINLY NORTHERN
PORTIONS OF LAKE SUPERIOR LATER TONIGHT THROUGH SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...KC
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
113 AM EDT SAT SEP 27 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 356 PM EDT FRI SEP 26 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH NEAR
THE WEST COAST AND A PROMINENT RIDGE ACROSS THE PLAINS INTO NRN
ONTARIO. AT THE SFC...WEAK SRLY FLOW WAS OBSERVED THROUGH WI AND
UPPER MI BETWEEN HIGH PRES OVER LAKE HURON AND A TROUGH THROUGH THE
WRN PLAINS. VIS LOOP INDICATED SCT CU UPSTREAM OVER THE UPPER MS
VALLEY AS LOW LEVEL MOISTURE INCREASES. OTHERWISE...COMPLETELY CLEAR
SKIES PREVAILED ACROSS UPPER MICHIGAN. DEWPOINTS WERE GENERALLY IN
THE LOWER 50S...WITH SOME HIGHER VALUES IN THE MID 50S OVER THE EAST
DOWNWIND OF LAKE MICHIGAN.
TONIGHT...WITH THE UPPER AND SFC RIDGE NEARLY STATIONARY OVER THE
AREA...EXPECT FOG TO REDEVELOP IN AREAS SIMILAR TO THU NIGHT...WITH
THE LOWEST VISIBILITIES OVER THE CNTRAL AND EAST AND ESPECIALLY
NEAR LAKE MICHIGAN.
SAT...A MID LEVEL TROUGH AND ASSOCIATED SFC LOW WILL MOVE THROUGH
FAR NRN ONTARIO TO SRN HUDSON BAY DRAGGING A COLD FRONT TO NEAR
CYPL. SRLY FLOW AHEAD OF FRONT WILL KEEP THE WARM AIR ACROSS THE
CWA. AFTER ANY MORNING FOG BURNS OFF...SUNNY SKIES WILL AGAIN
DOMINATE THE AREA. FCST SOUNDINGS SUGGEST THAT MIXING TO AROUND 850
MB (TEMPS AROUND 14C) WILL SUPPORT MAX READINGS INT THE UPPER 70S TO
NEAR 80.
&
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 332 PM EDT FRI SEP 26 2014
THE RELATIVELY WARM STREAK SEEN OVER THE PAST WEEK WILL COME TO AN
END EARLY NEXT WEEK AS A MORE PROGRESSIVE PATTERN DEVELOPS OVER THE
CENTRAL U.S.
SATURDAY NIGHT...WEAK MID-LEVEL RIDGING WILL BE OVER THE REGION AT
THE BEGINNING OF THE PERIOD AS A SLOW MOVING COLD FRONT STRETCHES
FROM NORTH DAKOTA TO HUDSON BAY. THIS FRONT WILL BE THE MAIN PLAYER
IN PRECIP CHANCES EARLY NEXT WEEK.
WITH THE LIGHT SOUTHERLY FLOW AND A CONTINUED INCREASE OF SFC
MOISTURE SATURDAY NIGHT...FOG WILL BE POSSIBLE ONCE AGAIN ACROSS THE
INTERIOR CENTRAL AND EAST. HOWEVER...DAYTIME MIXING ON SATURDAY MAY
LOWER DEWPOINTS FARTHER THAN MODELS ARE INDICATING. THIS LIKELY WILL
NOT BE REALIZED UNTIL SATURDAY AFTERNOON...SO WILL CONTINUE WITH THE
MENTION OF AREAS OF FOG.
SUNDAY...THE COLD FRONT WILL INCH CLOSER TO THE REGION ON
SUNDAY...BUT SHOULD HOLD OFF REACHING THE KEWEENAW UNTIL SUNDAY
EVENING. SUNDAY WILL BE THE LAST DAY IN THIS WARM STRETCH. WITH 850
HPA TEMPS STILL 12 TO 14C ACROSS THE CWA...HIGHS WILL BE WELL INTO
THE 70S FOR MUCH OF THE AREA. THESE VALUES ARE 15-20F ABOVE AVERAGES
IN THE LOW 60S THIS TIME OF YEAR. SEVERAL MODELS ARE INDICATING SOME
AFTERNOON DIURNAL SHOWERS ALONG THE LAKE BREEZE NORTH-CENTRAL. AM
STILL HAVING A HARD TIME BUYING INTO THIS AS LOW-LEVEL MOISTURE
APPEARS TO BE OVERDONE BY THE MODELS AND DEEP-LAYER MOISTURE IS
MARGINAL. DAYTIME MIXING ALONG WITH QUICKLY DIMINISHING
EVAPOTRANSPIRATION THIS TIME OF YEAR SHOULD LIMIT THE OVERALL SFC
MOISTURE AND INSTABILITY.
SUNDAY NIGHT AND MONDAY...THE COLD FRONT WILL ARRIVE ACROSS
THE KEWEENAW EARLY SUNDAY EVENING AND CONTINUE SINKING SOUTHWARD
THROUGH THE NIGHT. A DECENT AMOUNT OF LINEAR FORCING WILL BE
AVAILABLE THROUGH LOW-LEVEL FGEN...MID-LEVEL Q-VECTOR CONV...AND THE
RIGHT ENTRANCE OF AN UPPER JET. THIS SUGGESTS CONTINUING WITH LIKELY
POPS FOR MUCH OF THE AREA. TIMING OF THE PRECIP REMAINS A
SIGNIFICANT CHALLENGE DUE TO MODEL DIFFERENCE AND INCONSISTENCY. THE
12Z NAM SOLUTION HAS COME IN MUCH DIFFERENT FROM PREVIOUS RUNS AND
OTHER MODELS. THE SLOWER PROGRESSION OF THE TROUGH BY THE NAM DELAYS
PRECIP UNTIL LATE SUNDAY NIGHT. WITH THAT SAID MONDAYS FORECAST
BECOMES QUITE TRICKY AS THE TEMP AND PRECIP FORECAST HINGES ON HOW
FAR SOUTH THE FRONT MAKES IT SUNDAY NIGHT. A FASTER SOLUTION /ECMWF/
WOULD RESULT IN A MUCH COOLER DAY WITH SHOWERS FOR THE ENTIRE CWA. A
SLOWER SOLUTION /NAM/ WOULD ALLOW DIABATIC HEATING ACROSS THE
SOUTH-CENTRAL TO STALL THE FRONT EVEN MORE...BRINGING MUCH COOLER
CONDITIONS AND SHOWERS TO JUST THE NORTHERN CWA. HAVE OPTED TO TREND
TOWARD THE SLOWER IDEA AS EVEN THE 12Z GFS SLOWED THE PROGRESSION OF
THE FRONT. OVERALL...CONFIDENCE IS FAIRLY HIGH ON THE LIKELIHOOD OF
RAIN...BUT LOW ON THE TIMING.
MONDAY NIGHT AND TUESDAY...MID-LEVEL RIDGING WILL BEGIN BUILDING
ACROSS THE UPPER GREAT LAKES MONDAY NIGHT AS THE SFC FRONT CONTINUES
SSE OUT OF THE AREA. LOW-LEVEL MOISTURE WILL LINGER WELL INTO
TUESDAY WITH WEAK NE FLOW OFF LAKE SUPERIOR. THIS SHOULD LEAD TO AT
LEAST SOME UPSLOPE SHOWERS/DRIZZLE CENTRAL AND EAST ALONG LAKE
SUPERIOR THROUGH MONDAY NIGHT. THEN...AN INVERSION AROUND 3KFT
COMBINED WITH THE WEAKENING IMPACT OF THE SUN FOR MIXING...MAY KEEP
THE AREA SOCKED IN WITH LOW CLOUDS THROUGHOUT THE DAY TUESDAY. HAVE
THUS CONTINUED THE TREND OF LOWERING HIGH TEMPS FOR TUESDAY...WITH
HIGHS GENERALLY IN THE 50S CWA-WIDE. ALSO...WITH LOW-LEVEL HIGH
PRESSURE SHIFTING EASTWARD NORTH OF LAKE SUPERIOR AND INITIATING
RETURN SOUTHERLY FLOW ACROSS THE AREA...IT MAY EVEN BE DIFFICULT TO
COMPLETELY RID THE AREA OF LOW CLOUDS BY TUESDAY NIGHT.
WEDNESDAY THROUGH FRIDAY...DEEP TROUGHING OVER THE NORTHERN ROCKIES
WILL BE LIFTING NORTHEASTWARD AS MID-LEVEL RIDGING OVER THE UPPER
GREAT LAKES SHIFTS EASTWARD. MODEL GUIDANCE IS IN FAIRLY GOOD
AGREEMENT WITH THE SYNOPTIC PATTERN...BUT DIFFERS SOMEWHAT WITH THE
OVERALL INTENSITY OF THE TROUGH AND ASSOCIATED SFC LOW. ATTM...A
COLD FRONT IS PROGGED TO SLOWLY TRACK EASTWARD ACROSS THE CWA
WEDNESDAY MORNING THROUGH THURSDAY NIGHT AS THE SFC LOW MOVES
NORTHWARD OVER MANITOBA. WILL MAINTAIN CONSENSUS POPS...WITH AN
EMPHASIS FOR BETTER CHANCES ON THURSDAY WITH THE ARRIVAL OF
UPPER-LEVEL SUPPORT FROM THE RIGHT ENTRANCE OF A JET.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 110 AM EDT SAT SEP 27 2014
PLENTY OF DRY AIR ASSOCIATED WITH HI PRES CENTERED NEAR LK HURON
WILL BRING PREDOMINANT VFR CONDITIONS AT ALL 3 SITES THIS FCST
PERIOD. FOG...WITH POSSIBLE IFR VSBYS...IS POSSIBLE AT SAW TOWARD
SUNRISE. A BIT STRONGER SSW FLOW WILL LIMIT THE POTENTIAL FOR FOG AT
CMX AND IWD. GUSTY SSW WINDS WILL DVLP AT IWD AND PERHAPS SAW IN THE
AFTN WITH SOME DAYTIME HEATING/MIXING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 356 PM EDT FRI SEP 26 2014
A HIGH PRESSURE CENTERED OVER THE LOWER GREAT LAKES WILL REMAIN
STATIONARY THROUGH SUNDAY WHILE STRETCHING A RIDGE NORTHWEST ACROSS
THE UPPER GREAT LAKES. THIS WILL LEAD TO LIGHT SOUTHERLY FLOW
(BELOW 20KTS) INTO SUNDAY. A COLD FRONT DROPPING SOUTHEAST ACROSS
THE UPPER GREAT LAKES SUNDAY NIGHT INTO MONDAY MORNING WILL SHIFT
WINDS AROUND TO THE NORTHEAST WITH GUSTS TO 30KTS. HIGH PRESSURE
CENTERED OVER EASTERN CANADA WILL THEN PLACE A RIDGE OVER THE UPPER
GREAT LAKES FOR MONDAY NIGHT AND TUESDAY...LEADING TO DIMINISHING
WINDS.
WITH MORE MOIST AIR BEGINNING TO WORK NORTH OVER LAKE
SUPERIOR...THERE IS THE POTENTIAL FOR PATCHY/AREAS OF FOG OVER
NORTHERN PORTIONS OF LAKE SUPERIOR OVER THE NEXT COUPLE OF DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
421 AM EDT SAT SEP 27 2014
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE REGION FROM THE
NORTH THROUGH THE WEEKEND. A TROUGH OF LOW PRESSURE IS FORECAST
TO SLOWLY MOVE ACROSS THE REGION EARLY NEXT WEEK.
&&
.NEAR TERM /TODAY/...
AS OF 310 AM SATURDAY...SURFACE HIGH PRESSURE WILL CONTINUE TO
RIDGE INTO NORTH CAROLINA FROM THE NORTH TODAY. IR SATELLITE
IMAGERY INDICATES OCEANIC STRATOCUMULUS CLOUDS MOVING INLAND
ACROSS THE NORTHERN OUTER BANKS AND ALBEMARLE SOUND REGION AND
REMNANT CLOUDS OVER THE CRYSTAL COAST REGION. WILL HAVE TO WATCH
PROGRESS OF NORTHERN CLOUD DECK SPREADING INLAND AS IF THEY BECOME
WIDESPREAD/PERSISTENT THEY WILL HAVE AN EFFECT ON FOG POTENTIAL
WEST OF HIGHWAY 17 EARLY THIS MORNING WHERE WINDS HAVE DECOUPLED.
EAST OF HIGHWAY 17 WINDS LIKELY TO KEEP MIXING OVERNIGHT
INHIBITING RADIATIONAL FOG DEVELOPMENT BUT POSSIBLY CONTRIBUTING
TO LOW STRATUS CLOUD FORMATION AROUND SUNRISE.
ANY CLOUDS/FOG THAT FORM WILL MIX OUT BY MID MORNING. SHALLOW
MOISTURE PROFILES AND AND LACK OF FORCING WITH UPPER RIDGING OVER
THE AREA WILL PRECLUDE PRECIPITATION DEVELOPMENT TODAY AND WILL
CONTINUE WITH A DRY FORECAST. TEMPERATURES WILL BE WARMER TODAY
WITH MORE SUNSHINE WITH HIGHS AROUND 80 INLAND AND THE MIDDLE 70S
BEACHES.
&&
.SHORT TERM /TONIGHT/...
AS OF 310 AM SATURDAY...HIGH PRESSURE WILL CONTINUE TO RIDGE INTO
THE AREA FROM THE NORTH TONIGHT WITH CONTINUED DRY WEATHER
EXPECTED. LOOKS LIKE LIGHT WINDS WILL BE MORE WIDESPREAD WITH A
WEAKER PRESSURE GRADIENT FORECAST AND WITH LESS CLOUD COVER THERE
WILL BE A POTENTIAL FOR PATCHY RADIATIONAL FOG TO DEVELOP LATE.
LOWS WILL RANGE FROM AROUND 60 INLAND TO THE UPPER 60S BEACHES.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 420 AM SAT...NO SIGNIFICANT CHANGES MADE TO PREVIOUS
FORECAST. SFC HIGH PRESSURE WILL REMAIN TO THE NORTH SUNDAY AND
WITH MID LEVEL RIDGE OVER THE AREA EXPECT PRED DRY WEATHER. LOW
LEVEL THICKNESS VALUES AND NE FLOW SUPPORT HIGHS IN THE UPPER
70S/LOW 80S. THE HIGH WILL WEAKEN SUN NIGHT AND MON...AS WEAK AREA
OF LOW PRESSURE DEVELOPS IN THE DEEP SOUTH AND MOVES THROUGH THE
SE STATES. MODELS CONTINUE TO DIFFER SLIGHTLY IN STRENGTH AND
RELATED SFC LOW TRACK. ECMWF TRACK OF LOW ALONG COAST PREFERRED
WITH LOW DEEPENING OFF MID ATLC COAST TUE NIGHT-WED NIGHT AS UPR
LOW MOVES FROM GREAT LAKES ACROSS SRN NEW ENGLAND. THIS WILL
RESULT IN INCREASING POPS OVER ERN NC LATE MONDAY AND MONDAY NIGHT
WITH LIKELY POPS ACROSS AREA LATE MON NIGHT AND EARLY
TUESDAY...AND SC TSTMS ALONG COAST WITH PSBL WARM SECTOR CONDITIONS.
PERIODS OF HEAVY RAIN WILL BE POSSIBLE WITH PWATS OVER 2 INCHES.
PRECIP THREAT WILL DIMINISH TUE NIGHT AND WED AS LOW MOVES TO NE BUT
KEPT LINGERING SLGT CHC NE SECTIONS WED NIGHT.
SFC RIDGING AND ZONAL FLOW ALOFT ON SRN PERIPHERY OF UPR LOW WILL
PRODUCE DRY CONDITIONS THU-FRI. TEMPS NEAR NORMAL MON-FRI...WITH
HIGHS IN THE 70S AND OVERNIGHT LOWS IN THE LOW 60S/AROUND 70
DEGREES.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1245 AM SATURDAY...DIFFICULT FORECAST WITH REGARDS TO IFR
POTENTIAL TONIGHT AS DRY INTRUSION THIS EVENING HAS LED TO MUCH
SHALLOWER LOW LEVEL MOISTURE PROFILES THAN PREVIOUS FEW NIGHTS.
THINK BEST POTENTIAL FOR SUB VFR CONDITIONS WILL BE AT KPGV AND
KISO WHERE WINDS HAVE ALREADY DECOUPLED AND WHERE THE HIGH
RESOLUTION GUIDANCE IS INDICATING THE BEST POTENTIAL FOR FOG. AT
KEWN AND KOAJ THE ATMOSPHERE IS LIKELY TO REMAIN MIXED INHIBITING
FOG FORMATION BUT POSSIBLY LEADING TO THE DEVELOPMENT OF IFR
CEILINGS IN STRATUS AFTER 10Z AS DEPICTED IN THE BUFKIT PROFILES
AND THE HRRR AND NARRE GUIDANCE. THE LOW CLOUDS AND FOG WILL
DISSIPATE BY 15Z SATURDAY WITH PREVAILING VFR THEN EXPECTED
THROUGH SATURDAY EVENING. LATE SATURDAY CONDITIONS WILL FAVORABLE
FOR A BRIEF PERIOD OF SUB VFR CONDITIONS IN FOG AT ALL THE TAF
SITES.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 315 AM SAT...LINGERING SUB-VFR CONDITIONS POSSIBLE INTO MID
MORNING SUNDAY...IMPROVING TO VFR. PERIODS OF SUB-VFR EXPECTED
LATE MON THROUGH TUE AS WEAK SFC LOW MOVES ALONG THE COAST WITH
PERIODS OF RAIN. CONDITIONS IMPROVING ON WED WITH HIGH PRESSURE
BUILDING INTO THE REGION.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 310 AM SATURDAY...SMALL CRAFT ADVISORIES WILL CONTINUE FOR
ALL OF THE COASTAL WATERS. HIGH PRESSURE WILL REMAINED CENTERED
NORTH OF THE WATERS THROUGH TONIGHT PRODUCING NE FLOW 15-20 KT
ACROSS THE WATERS TODAY...DIMINISHING TO 10 TO 15 KT TONIGHT.
WAVEWATCH AND SWAN CONTINUE TO BE IN GOOD AGREEMENT IN FORECASTING
SEAS OF 4 TO 7 FT TODAY TO SUBSIDE TO 3 TO 5 FT LATE TONIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 315 AM SAT...HIGH PRESSURE WILL REMAIN TO THE NORTH SUN
RESULTING IN CONTINUED NE FLOW 10-15KT AND SEAS 3-5FT. HIGH WILL
WEAKEN SUN NIGHT AND MON...AS WEAK SFC LOW APPROACHES FROM THE
SW...AND IS PROGGED TO MOVE ALONG COAST MON NIGHT AND
TUE...DEEPENING OFF MID-ATLANTIC COAST TUE NIGHT AND WED. THIS
WILL RESULT IN STRONGEST WINDS FROM N-NW OVER NRN AND CENTRAL
WATERS TUE NIGHT AND WED....MAINLY 15-20 KTS. PERIOD OF SCA
CONDITIONS POSSIBLE TUE NIGHT INTO WED WITH SEAS BUILDING TO 4-6FT
IN STRONGER N/NW WINDS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR AMZ156-
158.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR AMZ150.
&&
$$
SYNOPSIS...JME
NEAR TERM...JME
SHORT TERM...JME
LONG TERM...JBM/CQD
AVIATION...JME/CQD
MARINE...JME/CQD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
323 AM EDT SAT SEP 27 2014
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE REGION FROM THE
NORTH THROUGH THE WEEKEND. A TROUGH OF LOW PRESSURE IS FORECAST
TO SLOWLY MOVE ACROSS THE REGION EARLY NEXT WEEK.
&&
.NEAR TERM /TODAY/...
AS OF 310 AM SATURDAY...SURFACE HIGH PRESSURE WILL CONTINUE TO
RIDGE INTO NORTH CAROLINA FROM THE NORTH TODAY. IR SATELLITE
IMAGERY INDICATES OCEANIC STRATOCUMULUS CLOUDS MOVING INLAND
ACROSS THE NORTHERN OUTER BANKS AND ALBEMARLE SOUND REGION AND
REMNANT CLOUDS OVER THE CRYSTAL COAST REGION. WILL HAVE TO WATCH
PROGRESS OF NORTHERN CLOUD DECK SPREADING INLAND AS IF THEY BECOME
WIDESPREAD/PERSISTENT THEY WILL HAVE AN EFFECT ON FOG POTENTIAL
WEST OF HIGHWAY 17 EARLY THIS MORNING WHERE WINDS HAVE DECOUPLED.
EAST OF HIGHWAY 17 WINDS LIKELY TO KEEP MIXING OVERNIGHT
INHIBITING RADIATIONAL FOG DEVELOPMENT BUT POSSIBLY CONTRIBUTING
TO LOW STRATUS CLOUD FORMATION AROUND SUNRISE.
ANY CLOUDS/FOG THAT FORM WILL MIX OUT BY MID MORNING. SHALLOW
MOISTURE PROFILES AND AND LACK OF FORCING WITH UPPER RIDGING OVER
THE AREA WILL PRECLUDE PRECIPITATION DEVELOPMENT TODAY AND WILL
CONTINUE WITH A DRY FORECAST. TEMPERATURES WILL BE WARMER TODAY
WITH MORE SUNSHINE WITH HIGHS AROUND 80 INLAND AND THE MIDDLE 70S
BEACHES.
&&
.SHORT TERM /TONIGHT/...
AS OF 310 AM SATURDAY...HIGH PRESSURE WILL CONTINUE TO RIDGE INTO
THE AREA FROM THE NORTH TONIGHT WITH CONTINUED DRY WEATHER
EXPECTED. LOOKS LIKE LIGHT WINDS WILL BE MORE WIDESPREAD WITH A
WEAKER PRESSURE GRADIENT FORECAST AND WITH LESS CLOUD COVER THERE
WILL BE A POTENTIAL FOR PATCHY RADIATIONAL FOG TO DEVELOP LATE.
LOWS WILL RANGE FROM AROUND 60 INLAND TO THE UPPER 60S BEACHES.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 315 AM SAT...NO SIGNIFICANT CHANGES MADE TO PREVIOUS
FORECAST. SFC HIGH PRESSURE WILL REMAIN TO THE NORTH SUNDAY AND
WITH MID LEVEL RIDGE OVER THE AREA EXPECT PRED DRY WEATHER. LOW
LEVEL THICKNESS VALUES AND NE FLOW SUPPORT HIGHS IN THE UPPER
70S/LOW 80S. THE HIGH WILL WEAKEN SUN NIGHT AND MON...AS WEAK AREA
OF LOW PRESSURE DEVELOPS IN THE DEEP SOUTH AND MOVES THROUGH THE
SE STATES. MODELS CONTINUE TO DIFFER SLIGHTLY IN STRENGTH AND
RELATED SFC LOW TRACK. ECMWF TRACK OF LOW ALONG COAST PREFERRED
WITH LOW DEEPENING OFF MID ATLC COAST TUE NIGHT-WED NIGHT AS UPR
LOW MOVES FROM GREAT LAKES ACROSS SRN NEW ENGLAND. THIS WILL
RESULT IN INCREASING POPS OVER ERN NC LATE MONDAY AND MONDAY NIGHT
WITH LIKELY POPS ACROSS AREA LATE MON NIGHT AND EARLY
TUESDAY...AND SC TSTMS ALONG COAST WITH PSBL WARM SECTOR
CONDITIONS. PRECIP THREAT WILL DIMINISH TUE NIGHT AND WED AS LOW
MOVES TO NE BUT KEPT LINGERING SLGT CHC NE SECTIONS WED NIGHT.
SFC RIDGING AND ZONAL FLOW ALOFT ON SRN PERIPHERY OF UPR LOW WILL
PRODUCE DRY CONDITIONS THU-FRI. TEMPS NEAR NORMAL MON-FRI...WITH
HIGHS IN THE 70S AND OVERNIGHT LOWS IN THE LOW 60S/AROUND 70
DEGREES.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1245 AM SATURDAY...DIFFICULT FORECAST WITH REGARDS TO IFR
POTENTIAL TONIGHT AS DRY INTRUSION THIS EVENING HAS LED TO MUCH
SHALLOWER LOW LEVEL MOISTURE PROFILES THAN PREVIOUS FEW NIGHTS.
THINK BEST POTENTIAL FOR SUB VFR CONDITIONS WILL BE AT KPGV AND
KISO WHERE WINDS HAVE ALREADY DECOUPLED AND WHERE THE HIGH
RESOLUTION GUIDANCE IS INDICATING THE BEST POTENTIAL FOR FOG. AT
KEWN AND KOAJ THE ATMOSPHERE IS LIKELY TO REMAIN MIXED INHIBITING
FOG FORMATION BUT POSSIBLY LEADING TO THE DEVELOPMENT OF IFR
CEILINGS IN STRATUS AFTER 10Z AS DEPICTED IN THE BUFKIT PROFILES
AND THE HRRR AND NARRE GUIDANCE. THE LOW CLOUDS AND FOG WILL
DISSIPATE BY 15Z SATURDAY WITH PREVAILING VFR THEN EXPECTED
THROUGH SATURDAY EVENING. LATE SATURDAY CONDITIONS WILL FAVORABLE
FOR A BRIEF PERIOD OF SUB VFR CONDITIONS IN FOG AT ALL THE TAF
SITES.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 315 AM SAT...LINGERING SUB-VFR CONDITIONS POSSIBLE INTO MID
MORNING SUNDAY...IMPROVING TO VFR. PERIODS OF SUB-VFR EXPECTED
LATE MON THROUGH TUE AS WEAK SFC LOW MOVES ALONG THE COAST WITH
PERIODS OF RAIN. CONDITIONS IMPROVING ON WED WITH HIGH PRESSURE
BUILDING INTO THE REGION.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 310 AM SATURDAY...SMALL CRAFT ADVISORIES WILL CONTINUE FOR
ALL OF THE COASTAL WATERS. HIGH PRESSURE WILL REMAINED CENTERED
NORTH OF THE WATERS THROUGH TONIGHT PRODUCING NE FLOW 15-20 KT
ACROSS THE WATERS TODAY...DIMINISHING TO 10 TO 15 KT TONIGHT.
WAVEWATCH AND SWAN CONTINUE TO BE IN GOOD AGREEMENT IN FORECASTING
SEAS OF 4 TO 7 FT TODAY TO SUBSIDE TO 3 TO 5 FT LATE TONIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 315 AM SAT...HIGH PRESSURE WILL REMAIN TO THE NORTH SUN
RESULTING IN CONTINUED NE FLOW 10-15KT AND SEAS 3-5FT. HIGH WILL
WEAKEN SUN NIGHT AND MON...AS WEAK SFC LOW APPROACHES FROM THE
SW...AND IS PROGGED TO MOVE ALONG COAST MON NIGHT AND
TUE...DEEPENING OFF MID-ATLANTIC COAST TUE NIGHT AND WED. THIS
WILL RESULT IN STRONGEST WINDS FROM N-NW OVER NRN AND CENTRAL
WATERS TUE NIGHT AND WED....MAINLY 15-20 KTS. PERIOD OF SCA
CONDITIONS POSSIBLE TUE NIGHT INTO WED WITH SEAS BUILDING TO 4-6FT
IN STRONGER N/NW WINDS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR AMZ156-
158.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR AMZ150.
&&
$$
SYNOPSIS...JME
NEAR TERM...JME
SHORT TERM...JME
LONG TERM...JBM/CQD
AVIATION...JME/CQD
MARINE...JME/CQD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1245 AM EDT SAT SEP 27 2014
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE REGION FROM THE
NORTH THROUGH THE WEEKEND. A TROUGH OF LOW PRESSURE IS FORECAST
TO SLOWLY MOVE ACROSS THE REGION EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1245 AM SATURDAY...SURFACE HIGH PRESSURE CONTINUE TO RIDGE
INTO NORTH CAROLINA FROM THE NORTH WITH THE DRY INTRUSION FINALLY
WORKING ITS WAY THROUGH THE REGION THIS EVENING HELPING TO ERODE
MOST OF THE LOW CLOUD DECK WHICH HAS BEEN PLAGUING THE REGION FOR
THE PAST SEVERAL DAYS. IR SATELLITE IMAGERY INDICATES OCEANIC
STRATOCUMULUS CLOUDS MOVING INLAND ACROSS THE NORTHERN OUTER BANKS
AND ALBEMARLE SOUND REGION AND REMNANT CLOUDS OVER THE CRYSTAL
COAST REGION. WILL HAVE TO WATCH PROGRESS OF NORTHERN CLOUD DECK
SPREADING INLAND AS IF THEY BECOME WIDESPREAD/PERSISTENT THEY WILL
HAVE AN EFFECT ON FOG POTENTIAL WEST OF HIGHWAY 17 WHERE WIND
SHOULD DECOUPLE OVERNIGHT. EAST OF HIGHWAY 17 WINDS LIKELY TO KEEP
MIXING OVERNIGHT INHIBITING RADIATIONAL FOG DEVELOPMENT BUT
POSSIBLY CONTRIBUTING TO LOW STRATUS CLOUD FORMATION AROUND
SUNRISE. SHALLOW MOISTURE PROFILES AND AND LACK OF FORCING WITH
UPPER RIDGING OVER THE AREA WILL PRECLUDE PRECIPITATION AND WILL
CONTINUE WITH A DRY FORECAST. LOWS GENERALLY IN THE LOW TO MID
60S (UPPER 60S COAST) WITH SOME UPPER 50S INLAND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM SUNDAY/...
AS OF 315 PM FRIDAY...HIGH PRES WILL CONTINUE TO DOMINATE ACROSS
THE REGION BRINGING NE FLOW. EXPECT TO SEE SIGNIFICANTLY MORE
SUNSHINE THAN THE PREVIOUS COUPLE DAYS WITH SHOWERS REMAINING
OFFSHORE BUT EXPECT SCT CU THROUGH THE AFTERNOON. LOW LEVEL
THICKNESSES CHANGE LITTLE BUT MORE SUN WILL ALLOW TEMPS TO WARM
INTO THE UPPER 70S.
&&
.LONG TERM /SUNDAY THROUGH SATURDAY/...
AS OF 300 PM FRIDAY...MODEL CONSENSUS BLEND USED FOR SAT NIGHT
THROUGH MON PERIOD...THEN LEAN TO 12Z ECMWF/WPC FOR REST OF PERIOD.
SFC AND MID LVL RIDGE WILL PRODUCE DRY WX FOR AREA SAT NIGHT...THEN
MOVE E SUN AND SUN NIGHT WITH A SLIGHT CHANCE OF SHOWERS ALONG COAST
WITH GRADUALLY VEERING ONSHORE FLOW.
MODELS GENERALLY AGREE ON MID LVL TROF MOVING IN MONDAY AND MON
NIGHT BUT SOME DIFFERENCE IN STRENGTH AND RELATED SFC LOW TRACK.
ECMWF TRACK OF LOW ALONG COAST PREFERRED WITH LOW DEEPENING OFF MID
ATLC COAST TUE NIGHT-WED NIGHT AS UPR LOW MOVES FROM GREAT LAKES
ACROSS SRN NEW ENGLAND. THIS WILL RESULT IN INCREASING POPS OVER ERN
NC LATE LATE MONDAY AND MONDAY NIGHT WITH LIKELY POPS ACROSS AREA
LATE MON NIGHT AND EARLY TUESDAY...AND CHC TSTMS ALONG COAST WITH
PSBL WARM SECTOR CONDITIONS.
PCPN THREAT WILL DIMINISH TUE NIGHT AND WED AS LOW MOVES TO NE BUT
KEPT LINGERING SLGT CHC NE SECTIONS WED NIGHT. SFC RIDGING AND ZONAL
FLOW ALOFT ON SRN PERIPHERY OF UPR LOW WILL PRODUCE DRY CONDITIONS
THU-FRI.
TEMPS SLIGHTLY ABOVE NORMAL FOR SAT NIGHT INTO MON...THEN NEAR
NORMAL REST OF PERIOD WITH NO SIGNIFICANT ARCTIC TAP EXPECTED BEHIND
DEPARTING SFC LOW MID WEEK.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH SATURDAY EVENING/...
AS OF 1245 AM SATURDAY...DIFFICULT FORECAST WITH REGARDS TO IFR
POTENTIAL TONIGHT AS DRY INTRUSION THIS EVENING HAS LED TO MUCH
SHALLOWER LOW LEVEL MOISTURE PROFILES THAN PREVIOUS FEW NIGHTS.
THINK BEST POTENTIAL FOR SUB VFR CONDITIONS WILL BE AT KPGV AND
KISO WHERE WINDS HAVE ALREADY DECOUPLED AND WHERE THE HIGH
RESOLUTION GUIDANCE IS INDICATING THE BEST POTENTIAL FOR FOG. AT
KEWN AND KOAJ THE ATMOSPHERE IS LIKELY TO REMAIN MIXED INHIBITING
FOG FORMATION BUT POSSIBLY LEADING TO THE DEVELOPMENT OF IFR
CEILINGS IN STRATUS AFTER 10Z AS DEPICTED IN THE BUFKIT PROFILES
AND THE HRRR AND NARRE GUIDANCE. THE LOW CLOUDS AND FOG WILL
DISSIPATE BY 15Z SATURDAY WITH PREVAILING VFR THEN EXPECTED
THROUGH SATURDAY EVENING. LATE SATURDAY CONDITIONS WILL FAVORABLE
FOR A BRIEF PERIOD OF SUB VFR CONDITIONS IN FOG AT ALL THE TAF
SITES.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...VFR CONDITIONS EXPECTED TO PREVAIL THROUGH
EARLY MONDAY AS HIGH PRES OVER AREA GRADUALLY MOVES OFFSHORE.
PERIODS OF SUB-VFR EXPECTED LATE MON THROUGH TUE WITH SFC LOW
MOVING ALONG COAST. CONDITIONS IMPROVING ON WED WITH HIGH PRES
BUILDING IN.
&&
.MARINE...
SHORT TERM /THROUGH SATURDAY/...
AS OF 1245 AM SATURDAY...HIGH PRES WILL REMAINED CENTERED NORTH OF
THE AREA THROUGH THE SHORT TERM PERIOD PRODUCING NE FLOW 10-20 KT
ACROSS THE WATERS. WAVEWATCH AND SWAN IN GOOD AGREEMENT INDICATING
4-7 FT SEAS NORTH OF OCRACOKE INLET THROUGH SAT AND 3-6 FT SOUTH
TONIGHT SUBSIDING TO 3-5 FT SAT. ADJUSTED THE SCA TO END AT 7 AM
SAT SOUTH OF OCRACOKE INLET BUT WILL KEEP TO THE NORTH THROUGH
SAT.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...MODEL BLEND USED FOR SAT NIGHT THROUGH EARLY
MON PERIOD...THEN LEANED TO ECMWF FOR LATE MON-WED. MODERATE NE
WINDS WILL PERSIST SAT NIGHT AND SUN...THEN WEAKEN SUN NIGHT. SFC
LOW WILL APPROACH FROM SW LATE MONDAY...AND MOVE ALONG COAST MON
NIGHT AND TUE...DEEPENING OFF MID ATLC COAST TUE NIGHT AND WED. THIS
WILL RESULT IN STRONGEST WINDS FROM N-NW OVER NRN AND CENTRAL WATERS
TUE NIGHT AND WED....MAINLY 15-20 KTS.
SEAS EXPECTED TO SUBSIDE BELOW 6 FT OVER NRN AND CENTRAL WATERS
SUNDAY...AND GENERALLY 2-4 FT ACROSS WATERS SUN NIGHT-MON NIGHT.
HEIGHTS BUILDING TO 4-6 FT NRN AND CENTRAL WATERS WITH STRONGER N-NW
WINDS TUE NIGHT AND WED.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR AMZ156-
158.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR AMZ150.
&&
$$
SYNOPSIS...SK
NEAR TERM...BTC/JME/SK
SHORT TERM...SK
LONG TERM...JBM
AVIATION...JBM/JME
MARINE...JBM/JME/SK
AREA FORECAST DISCUSSION
NWS PENDLETON OR
132 AM PDT SAT SEP 27 2014
.SHORT TERM...TODAY THROUGH MONDAY...UNSETTLED WEATHER WILL CONTINUE
TODAY AND MONDAY AS AN UPPER TROUGH MOVES ACROSS THE REGION. THE
OVERALL FLOW WILL BE SPLIT WITH A SUBTLE TROUGH OVER NORTHERN
WASHINGTON AND A CLOSED UPPER LOW OVER NORTHERN CALIFORNIA AND
SOUTHERN OREGON. THE MODELS ARE ADVERTISING WRAP AROUND MOISTURE ON
THE NORTH SIDE OF THE UPPER LOW TO MOVE INTO THE EAST AND SOUTHEAST
PORTION OF THE CWA TODAY THROUGH MONDAY. THE HRRR MODEL IS SHOWING
PRECIPITATION INCREASING FROM THE SOUTHEAST INTO THE EASTERN AND
NORTHEAST MOUNTAINS OF THE CWA TODAY. AS SUCH WILL KEEP A SLIGHT
CHANCE TO CHANCE POPS IN THE FORECAST FOR THE EASTERN AND SOUTHEAST
BORDER REGION OF THE CWA. THE ECMWF CONTINUES TO BE FURTHER TO THE
NORTH AND WEST WITH THE PRECIPITATION WHILE THE GFS SHOWS MUCH LESS.
IT WILL REMAIN DRY TODAY AND SUNDAY FOR THE REMAINDER OF THE CWA.
THEN ON MONDAY THE NEXT WEATHER SYSTEM BEGINS TO MOVE INTO THE
WASHINGTON CASCADES WITH SOME INCREASE IN PRECIPITATION THERE.
TEMPERATURES WILL REMAIN NEAR NORMAL THROUGH THE PERIOD AND WINDS
WILL BE FAIRLY LIGHT...WITH THE HIGHEST GUSTS OF 15-20 KTS IN THE
AFTERNOONS AND EARLY EVENING. 88
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...A BROAD UPPER LEVEL
TROUGH WILL MOVE ACROSS THE REGION MONDAY NIGHT AND TUESDAY WITH A
SLIGHT CHANCE FOR MAINLY MOUNTAIN SHOWERS AND BREEZY WINDS. A COOL
PRIMARILY DRY NW FLOW WILL WILL FOLLOW FOR WEDNESDAY AND THURSDAY AS
AN UPPER LEVEL RIDGE AMPLIFIES OFFSHORE. AS THE RIDGE MOVES OVER THE
AREA FOR FRIDAY AND SATURDAY...WARMING TEMPERATURES ARE EXPECTED. IT
SHOULD REMAIN MOSTLY DRY. THE ECMWF DOES SHOW A DISTURBANCE PASSING
TO THE NORTH OF THE REGION WITH PRECIPITATION IN WASHINGTON. FOR NOW
HAVE KEPT THE FORECAST AREA DRY EXCEPT FOR SLGT CHC POPS WA CASCADE
CREST. TEMPERATURES WILL START OUT NEAR TO SLIGHTLY BELOW NORMAL BUT
END UP ABOVE NORMAL BY FRIDAY AND SATURDAY. IT WILL BE QUITE COLD IN
THE MOUNTAIN VALLEYS WITH WIDESPREAD FREEZING TEMPERATURES. 78
&&
.AVIATION...12Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH 12Z
SUNDAY. MID AND HIGH CLOUDS ARE EXPECTED AT THE EASTERN TAF SITES
WITH MOSTLY CLEAR SKIES AT THE WESTERN SITES AS AN UPPER LEVEL LOW
PRESSURE SYSTEM MOVES TO OUR SE. WINDS WILL INCREASE FROM THE NW-N
THIS AFTERNOON AT 10-20 KT AND DIMINISH THIS EVENING. 78
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 71 52 72 52 / 10 10 10 10
ALW 74 55 74 56 / 10 10 10 10
PSC 77 53 77 52 / 0 10 10 10
YKM 74 51 76 49 / 10 0 0 10
HRI 76 50 76 50 / 10 10 10 10
ELN 72 49 73 48 / 10 0 0 10
RDM 66 39 68 39 / 10 10 10 10
LGD 67 45 68 45 / 20 20 20 20
GCD 66 44 68 43 / 20 20 20 20
DLS 75 53 77 54 / 10 10 10 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
88/78/78
AREA FORECAST DISCUSSION...UPDATED AVIATION DISCUSSION
NWS PENDLETON OR
1012 PM PDT FRI SEP 26 2014
.UPDATE...THE LARGE UPPER LEVEL TROUGH IS CONTINUING TO SPLIT WITH
CUT OFF LOW MOVING INTO NORTHERN CALIFORNIA TONIGHT. THERE IS A
BAND OF CIRRUS CLOUDS EXTENDING FROM THE LOW NORTH ACROSS EASTERN
OREGON...WHILE MOST OF THE CUMULUS CLOUDS FROM DAYTIME HEATING HAVE
DISSIPATED WITH PARTLY CLOUDY SKIES OVER THE REST OF THE REGION.
THERE WILL CONTINUE TO BE SLIGHT CHANCE OF SHOWERS ON SATURDAY ALONG
THE EAST SLOPES OF THE BLUE AND WALLOWA MOUNTAINS AS THE UPPER LEVEL
LOW MOVES INTO NEVADA WITH MOISTURE WRAPPING BACK AROUND THE LOW. I
ADJUSTED OVERNIGHT TEMPERATURES AND CLOUDS BASED ON CURRENT
CONDITIONS. ML
&&
.PREV DISC... /ISSUED 230 PM PDT FRI SEP 26 2014/
SHORT TERM...TONIGHT THROUGH MONDAY...A LARGE UPPER LEVEL TROUGH
HAS MOVED OVER THE PACIFIC NORTHWEST TODAY. A SPLIT FLOW IS
DEVELOPING IN THE TROUGH WITH A CLOSED LOW FORMING IN THE BASE OF
THE TROUGH IN NORTHERN CALIFORNIA AND ANOTHER LOW OVER THE CANADIAN
ROCKIES. THIS IS LEADING TO A WEST TO SOUTHWEST FLOW OVER THE AREA.
THE WESTERLY FLOW BROUGHT SHOWERS TO THE WASHINGTON CASCADE CREST
TODAY AND THAT SHOULD CONTINUE THIS EVENING THOUGH THE INTENSITY IS
LESSENING. ELSEWHERE SHOWERS HAVE BEEN SLOW TO DEVELOP AND HAVE CUT
BACK ON THE POPS FOR TONIGHT, LIMITING IT TO A SLIGHT CHANCE AND
REMOVING THEM FROM A FEW PLACES, MAINLY THE BLUE MOUNTAIN FOOTHILLS.
THE HRRR MODEL SHOWS A BAND OF SHOWERS DEVELOPING AFTER MIDNIGHT IN
SOUTHEAST OREGON AND PROGRESSING TO THE SOUTHERN EDGE OF OUR AREA SO
HAVE LEFT A SLIGHT CHANCE OF SHOWERS IN NORTHEAST OREGON WHILE THE
REST OF THE AREA DRIES OUT. ON SATURDAY THE SOUTHERN LOW WILL COME
ASHORE AND WILL BE CENTERED NEAR RENO IN THE AFTERNOON. IT WILL THEN
MOVE INTO CENTRAL NEVADA ON SUNDAY AND INTO UTAH AND WEAKEN BY
MONDAY. CIRCULATION AROUND THE LOW WILL BRING A NORTH TO NORTHEAST
WRAP AROUND FLOW INTO OUR AREA SATURDAY AND SUNDAY. THIS WILL LEAD
TO A SLIGHT CHANCE OF SHOWERS IN THE EASTERN OREGON MOUNTAINS MAINLY
IN THE AFTERNOON AND EVENING ON SATURDAY AND SUNDAY. BY MONDAY THE
FLOW WILL HAVE TURNED BACK TO WESTERLY AND ANOTHER SYSTEM WILL BE
APPROACHING THE COAST IN THE AFTERNOON WITH A SLIGHT CHANCE OF
SHOWERS DEVELOPING ALONG THE WASHINGTON CASCADE CREST WHILE A FEW
LINGERING SHOWERS WILL REMAIN OVER THE EASTERN OREGON MOUNTAINS.
TEMPERATURES WILL BE IN THE UPPER 60S TO MID 70S WITH 60S IN THE
MOUNTAINS WHILE LOWS WILL BE IN THE MID 40S TO MID 50S WITH MID 30S
TO MID 40S IN THE MOUNTAINS. PERRY
LONG TERM...MONDAY NIGHT THROUGH FRIDAY. A DISTURBANCE IS EXPECTED
TO PASS ACROSS THE REGION MONDAY NIGHT AND A FEW SHOWERS ARE
POSSIBLE ACROSS THE AREA MOUNTAINS. OTHERWISE A RETURN TO DRIER
CONDITIONS IS LIKELY TUESDAY AND WEDNESDAY AS A RIDGE OF HIGH
PRESSURE DRIFTS THROUGH THE AREA. ANOTHER WEAK DISTURBANCE IS
POSSIBLE THURSDAY THAT COULD INCREASE MID AND HIGH LEVEL CLOUDS
MAINLY ACROSS THE NORTHERN PARTS OF THE REGION ALONG WITH A FEW
SHOWERS ALONG THE EAST SLOPES OF THE WA CASCADES. BY FRIDAY A
STRONGER RIDGE OF HIGH PRESSURE IS EXPECTED WITH A SLIGHT WARMING
TREND EXPECTED TOWARD THE END OF THE WEEK.
.AVIATION...06Z TAFS...VFR CONDITIONS WILL PERSIST ACROSS THE AREA
OVER THE NEXT 24 HOURS. AN UPPER LEVEL LOW MOVING INTO NORTH CENTRAL
NEVADA WILL HELP TO BRING SOME HIGH CLOUDS MAINLY TO KALW AND KPDT
TAF SITES ON SATURDAY. A FEW CU COULD ALSO DEVELOP...MAINLY OVER AND
INVOF THE BLUE MOUNTAINS SATURDAY AFTERNOON. WINDS WILL BE LIGHT
OVERNIGHT BUT WILL INCREASE AND BECOME NORTHWEST AT 10 TO 15KTS
GUSTING TO 20-25KTS AFTER 19Z AT MOST TAF SITES...BEFORE DECREASING
AGAIN AFTER SUNSET. 77
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 50 73 52 72 / 10 10 10 10
ALW 54 74 55 74 / 10 10 10 10
PSC 48 77 53 76 / 0 0 10 10
YKM 48 73 51 75 / 10 10 0 0
HRI 50 75 50 75 / 0 10 10 10
ELN 48 74 49 76 / 10 10 0 0
RDM 39 66 39 67 / 10 10 10 10
LGD 47 66 45 68 / 10 10 20 20
GCD 43 64 44 68 / 10 10 20 20
DLS 54 76 53 78 / 10 10 10 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
93/97/97
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
711 AM CDT SAT SEP 27 2014
.AVIATION...
EXPECTING VFR FLIGHT CATEGORIES FOR TERMINAL SITES ACROSS THE ARKLATEX
THROUGH THE FORECAST PERIOD ENDING 28/12Z. MAINLY HIGH AND MIDDLE CLOUDS
SPREADING OVER THE REGION WITH SOME LIGHT SPRINKLES FROM SOME OF THE
MIDDLE LEVEL CLOUDS TODAY AND INTO THE EVENING WITH INFLUENCE FROM AN
UPPER LEVEL DISTURBANCE SHIFTING INTO THE REGION. SCATTERED TO
BROKEN CUMULUS CLOUDS AROUND 4-5 KFT DEVELOPING DURING THE DAY AND
LINGERING INTO THE OVERNIGHT HOURS. WINDS NORTHEAST TO EAST 5-10
KNOTS. /06/
&&
.PREV DISCUSSION... /ISSUED 530 AM CDT SAT SEP 27 2014/
DISCUSSION...
PARTLY TO MOSTLY CLOUDY SKIES WITH LOTS OF TEMPERATURES RANGING IN
THE 60S...BUT THERE ARE A FEW UPPER 50S NORTH OF I-30. OUR DEW
POINTS ARE COMING UP A BIT...BUT STILL A GOOD SPREAD WITH NO FOG
ISSUES EXCEPT AT THE COOLER SITE IN DEQUEEN. LAST NIGHT/S
SOUNDING IS RIGHT AT AN INCH OF PWAT AND THERE ARE A FEW SHOWERS
ARE SHOWING UP ON THE SHV 88D JUST OUTSIDE OF OUR CWA. THE RADAR
HAS BEEN OUT OF CLEAR AIR AND IN PRECIP MODE FOR MORE THAN A HALF
HOUR NOW WITH RAIN ON THE GROUND OUT OF MOSTLY MID DECK FROM SAT
TO ATT. THE UPPER LOW OVER THE RIO GRANDE IS BEING KICKED OUT A
BIT THIS MORNING BY THE LONG WAVE OVER THE WEST COAST. THE TEXAS
LOW IS IN FUJIWHARA MODE WITH THE MIDWEST LOW ALL ROTATING UNDER
THE BIG RIDGE OVER THE NORTHERN TIER AND SE CANADA. THE DIGGING
UPPER LOW OVER CALIFORNIA IS STILL TRYING TO MOVE SE...BUT APPEARS
TO HAVE MORE AN EASTWARD PUSH. AS THE LOW TO OUR SW CONTINUES TO
ROTATE UNDER THE MID WEST LOW IS SHOULD CONTINUE EASTWARD INTO OUR
PERIOD OF HEATING AND EDGE EASTWARD OVERNIGHT WHILE WASHING OUT ON
THE RIDGE. A MIX OF SHOWERS AND ISOLATED THUNDERSTORMS SHOULD
RESULT DESPITE LIMITED MODEL QPF.
THE HRRR WAS THE MOST INTERESTING AND WAS THE MODEL OF CHOICE FOR
TODAY. THE NAM WAS THE WARMEST AND MOS PERHAPS TOO COOL SO WE HAVE
SETTLED SOMEWHERE IN BETWEEN IN OUR FORECAST. THE MODELS REALLY DO
NOT PICK ON MUCH OF ANY QPF AND MAY PLAY CATCH UP WITH THIS NEXT
RUN FOLLOWING OUR ASCENT IN THE COMING HOUR.
AT ANY RATE THE FORECAST CONTINUES AS PLANNED WITH MORE TYPICALLY
DRY LATE SUMMER READINGS IN THE COMING DAYS. THE MEX IS LOOKING AT
A COUPLE OR FEW DAYS OF LOWER 90S. THE NEXT REAL DEAL COLD FRONT
IS MODELED WELL ON THE GFS AND IS OUR MODEL OF CHOICE FOR THE LONG
RANGE WITH NORTHERLY WINDS FILTERING IN LATE IN THE WEEK FOR A
FANTASTIC FOOTBALL FRIDAY NIGHT. HOPEFULLY THE WPC 1 TO TWO INCH
RAIN FOR OUR AREAS HOLDS TRUE OTHERWISE WE MAY BE LOOKING AT MORE
BURN BANS FOR THE FALL SEASON.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 89 66 89 66 89 / 20 20 10 10 10
MLU 87 66 85 64 87 / 10 20 20 10 10
DEQ 85 63 86 61 87 / 10 10 10 10 10
TXK 85 64 86 63 87 / 20 10 10 10 10
ELD 86 63 86 62 86 / 10 20 10 10 10
TYR 87 66 88 65 88 / 20 10 10 10 10
GGG 88 65 88 63 89 / 20 10 10 10 10
LFK 88 66 89 65 91 / 20 10 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
06
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
530 AM CDT SAT SEP 27 2014
.DISCUSSION...
PARTLY TO MOSTLY CLOUDY SKIES WITH LOTS OF TEMPERATURES RANGING IN
THE 60S...BUT THERE ARE A FEW UPPER 50S NORTH OF I-30. OUR DEW
POINTS ARE COMING UP A BIT...BUT STILL A GOOD SPREAD WITH NO FOG
ISSUES EXCEPT AT THE COOLER SITE IN DEQUEEN. LAST NIGHT/S
SOUNDING IS RIGHT AT AN INCH OF PWAT AND THERE ARE A FEW SHOWERS
ARE SHOWING UP ON THE SHV 88D JUST OUTSIDE OF OUR CWA. THE RADAR
HAS BEEN OUT OF CLEAR AIR AND IN PRECIP MODE FOR MORE THAN A HALF
HOUR NOW WITH RAIN ON THE GROUND OUT OF MOSTLY MID DECK FROM SAT
TO ATT. THE UPPER LOW OVER THE RIO GRANDE IS BEING KICKED OUT A
BIT THIS MORNING BY THE LONG WAVE OVER THE WEST COAST. THE TEXAS
LOW IS IN FUJIWHARA MODE WITH THE MIDWEST LOW ALL ROTATING UNDER
THE BIG RIDGE OVER THE NORTHERN TIER AND SE CANADA. THE DIGGING
UPPER LOW OVER CALIFORNIA IS STILL TRYING TO MOVE SE...BUT APPEARS
TO HAVE MORE AN EASTWARD PUSH. AS THE LOW TO OUR SW CONTINUES TO
ROTATE UNDER THE MID WEST LOW IS SHOULD CONTINUE EASTWARD INTO OUR
PERIOD OF HEATING AND EDGE EASTWARD OVERNIGHT WHILE WASHING OUT ON
THE RIDGE. A MIX OF SHOWERS AND ISOLATED THUNDERSTORMS SHOULD
RESULT DESPITE LIMITED MODEL QPF.
THE HRRR WAS THE MOST INTERESTING AND WAS THE MODEL OF CHOICE FOR
TODAY. THE NAM WAS THE WARMEST AND MOS PERHAPS TOO COOL SO WE HAVE
SETTLED SOMEWHERE IN BETWEEN IN OUR FORECAST. THE MODELS REALLY DO
NOT PICK ON MUCH OF ANY QPF AND MAY PLAY CATCH UP WITH THIS NEXT
RUN FOLLOWING OUR ASCENT IN THE COMING HOUR.
AT ANY RATE THE FORECAST CONTINUES AS PLANNED WITH MORE TYPICALLY
DRY LATE SUMMER READINGS IN THE COMING DAYS. THE MEX IS LOOKING AT
A COUPLE OR FEW DAYS OF LOWER 90S. THE NEXT REAL DEAL COLD FRONT
IS MODELED WELL ON THE GFS AND IS OUR MODEL OF CHOICE FOR THE LONG
RANGE WITH NORTHERLY WINDS FILTERING IN LATE IN THE WEEK FOR A
FANTASTIC FOOTBALL FRIDAY NIGHT. HOPEFULLY THE WPC 1 TO TWO INCH
RAIN FOR OUR AREAS HOLDS TRUE OTHERWISE WE MAY BE LOOKING AT MORE
BURN BANS FOR THE FALL SEASON.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 89 66 89 66 89 / 20 20 10 10 10
MLU 87 66 85 64 87 / 10 20 20 10 10
DEQ 85 63 86 61 87 / 10 10 10 10 10
TXK 85 64 86 63 87 / 20 10 10 10 10
ELD 86 63 86 62 86 / 10 20 10 10 10
TYR 87 66 88 65 88 / 20 10 10 10 10
GGG 88 65 88 63 89 / 20 10 10 10 10
LFK 88 66 89 65 91 / 20 10 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
24
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
740 AM EDT SAT SEP 27 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM EDT SAT SEP 27 2014
...ANOTHER UNSEASONABLY WARM LATE SEPT DAY IS ON THE WAY TODAY...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A STRONG RIDGE OVER MUCH
OF THE E HALF OF THE CONUS. CORE OF THE POSITIVE ANOMALIES WITH THE
RIDGE IS OVER NRN ONTARIO WHERE ANOMALIES ARE 2.5 STANDARD
DEVIATIONS ABOVE THE LONG TERM LATE SEPT AVG. WITHIN THE RIDGE...A
WEAK MID LEVEL LOW CENTERED ROUGHLY ALONG THE IA/MO BORDER IS
GENERATING ISOLD SHRA/TSRA OVER IA INTO SW MN. CLOSER TO HOME...THE
WEATHER REMAINS QUIET. TYPICAL FOR THIS TIME OF YEAR WITH THIS TYPE
OF WEATHER PATTERN THAT FEATURES QUIET/CLEAR NIGHTS...SHALLOW FOG
HAS AGAIN FORMED...MAINLY OVER SCNTRL AND ERN UPPER MI AND
ESPECIALLY NEAR RIVERS/LAKES/STREAMS.
WITH LITTLE OVERALL CHANGE IN AIR MASS TODAY COMPARED TO YESTEDAY...
TODAY WILL BE A CARBON COPY OF YESTERDAYS WEATHER. MIXING TO
AROUND 850MB SUPPORTS MAX TEMPS WELL INTO THE 70S TO THE LWR 80S
AWAY FROM LAKE MODERATION WHICH SHOULD BE CONFINED MAINLY TO AREAS
NEAR LAKE MICHIGAN. GIVEN THE SIMILAR AIR MASS CHARACTERISTICS...
SIMPLY USED YESTERDAYS OBSERVED MAX TEMPS FOR TODAYS FCST WITH A FEW
MINOR ADJUSTMENTS. DIURNAL TEMP RISE SHOULD BE NEARLY IDENTICAL TO
YESTERDAYS AS WELL...SO UTILIZED YESTERDAYS DIURNAL TEMP CURVE FOR
HOURLY TEMPS. SHALLOW FOG WILL QUICKLY DISSIPATE AFTER SUNRISE.
ANOTHER QUIET/CLEAR NIGHT IS EXPECTED TONIGHT. MIN TEMPS SHOULD BE A
LITTLE HIGHER THAN THIS MORNINGS MINS DUE TO SOME INCREASE IN
PRECIPITABLE WATER. SHALLOW FOG SHOULD MAKE ANOTHER APPEARANCE IN
GENERALLY THE SAME AREAS THAT IT HAS APPEARED IN RECENT NIGHTS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 354 AM EDT SAT SEP 27 2014
GOOD AGREEMENT IN OVERALL LOOK OF LARGER SCALE PATTERN INTO NEXT
WEEK. MAIN ISSUE REMAINS TIMING OF FRONT ON SUNDAY NIGHT INTO
MONDAY. ECMWF HAS STEADILY TRENDED TOWARD QUICKER FROPA ON SUNDAY
NIGHT WITH NNE WINDS OVER ALL OF UPR MICHIGAN BY 12Z MONDAY. NAM AND
GFS NOT AS AGGRESSIVE AND TREND FROM GFS IS MAINLY SLOWER...THOUGH
00Z RUN IS FARTHER SOUTH WITH FRONT BUT KEEPS MOST RAIN OUT OF CWA
UNTIL AFTER 12Z MONDAY. DIFFERENCES IN TIMING OF FROPA IS TIED TO
HOW MUCH JET ENERGY DIGS INTO BACKSIDE OF SHORTWAVE TROUGH CROSSING
NORTHERN ONTARIO. ECMWF SHOWS STRONGER JET/MORE AMPLFIED TROUGH
WHILE GFS AND GEM-NH SHOW MORE OF THE JET ENERGY AHEAD OF THE TROUGH
AND THUS A FLATTER MORE PROGRESSIVE TROUGH ALOFT. TOUGH TO SAY WHICH
IDEA IS RIGHT. MORE AMPLIED IDEA SEEMS GOOD AS MAIN SHORTWAVE
CURRENTLY OVER NORTHERN ALBERTA IS QUITE SHARP PER WV LOOP AND 00Z
RAOBS...BUT A MORE STRUNG OUT SHORTWAVE COULD ALSO OCCUR AS THE
RIDGE IT WILL BE DROPPING TOWARDS IS UNSEASONABLY STRONG WITH
590DAM HEIGHTS FM DAKOTAS OVER NORTHERN ONTARIO AND OVER SOUTHERN
QUEBEC AND LOWER GREAT LAKES.
CONSENSUS OF ALL MODELS AND THE CURRENT FORECAST POINTS TO FROPA LATE
SUNDAY NIGHT INTO MONDAY MORNING. WILL HEAD THIS WAY AS WELL. RESULT
WILL BE INCREASING RAIN CHANCES INTO MONDAY...LIKELY TURNING INTO
MORE OF A STRATIFORM RAIN BOOSTED BY H7-H5 Q-VECTOR CONVERGENCE WITH
THE SHORTWAVE AND ADDITIONAL LIFT WITHIN RIGHT ENTRANCE REGION OF JET
STREAK FM NORTHERN ONTARIO TO QUEBEC. SHALLOW COOL/MOIST FLOW
UPSLOPING INTO HIGHER TERRAIN NEAR LK SUPERIOR ONLY ADDS TO THE RAIN
CHANCES. TEMPS WILL EXHIBIT SHARP GRADIENT BTWN WHERE THE SUB H9 FLOW
IS STIFF ONSHORE AND WHERE MIXING TO H9 AND OFFSHORE WINDS WILL ALLOW
FOR TEMPS TO REACH NEAR 70 OVER THE SCNTRL. RAIN SHOULD DIMINISH TO
PROBABLY AREAS OF DRIZZLE LATER MONDAY NIGHT AS HIGH
PRESSURE/ANTICYCLONIC FLOW ADVANCES FURTHER INTO THE AREA. COOL TEMPS
PERSIST INTO TUESDAY...ESPECIALLY NEAR LK SUPERIOR WHERE WINDS STAY
ONSHORE ALL DAY.
RIDGING BUILDS BACK ALOFT BY WEDNESDAY AS TROUGHING EXPANDS OVER
WESTERN CONUS. WEDNESDAY WILL BE AN IN BTWN DAY AND COULD SEE AT
LEAST SOME SUNSHINE...AT LEAST IN THE EAST HALF. HIGH TEMPS WARMING
BACK INTO THE 60S AND POSSIBLY...WITH ENOUGH SUNSHINE...TOUCHING 70
DEGREES. LEADING SHORTWAVE EMERGING FM WEST CONUS TROUGH COULD BRING
SOME SHOWERS TO PARTS OF CWA BY WEDNESDAY EVENING. GREATEST CHANCES
OF RAIN LIKELY HOLD OFF TIL THURSDAY AS STRONGER FORCING ALOFT
COMBINES WITH MORE OF A LOW-LEVEL FRONTAL BOUNDARY. MODEL CONSISTENCY
IS SHAKY SO WILL NOT ALTER THE CONSENSUS POPS. INCLUDED SMALL CHANCES
FOR THUNDER ON THURSDAY AS THERE IS AT LEAST A BRIEF INTERLUDE OF
INSTABILITY WORKING ACROSS THE REGION AHEAD OF THE FRONT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 739 AM EDT SAT SEP 27 2014
DRY AIR ASSOCIATED WITH HIGH PRES CENTERED NEAR LAKE HURON WILL
CONTINUE TO BRING PREVAILING VFR CONDITIONS TO KIWD/KCMX/KSAW THRU
THIS FCST PERIOD. HOWEVER...AS HAS BEEN THE CASE THE LAST FEW
NIGHTS...SHALLOW RADIATIONAL FOG WILL DEVELOP AT NIGHT AND AFFECT
KSAW. LIFR CONDITIONS EARLY THIS MORNING AT KSAW WILL QUICKLY
IMPROVE TO VFR WITHIN AN HR OR TWO OF SUNRISE. LOW-LEVEL WINDS
TONIGHT WILL HAVE MORE OF A DOWNSLOPE WESTERLY COMPONENT...SO AT
THIS POINT...NOT ANTICIPATING KSAW TO DROP BLO MVFR LATE TONIGHT.
THIS AFTN...GUSTY SSW WINDS WILL DEVELOP AT KIWD AND PERHAPS KSAW
WITH DAYTIME HEATING/MIXING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 AM EDT SAT SEP 27 2014
LIGHT WINDS PERSIST THROUGH SUNDAY...THEN CHANGES ARE EXPECTED BY
MONDAY MORNING AS A FRONT WORKS NORTH TO SOUTH ACROSS LK SUPERIOR.
EXPECT WINDS TO SHIFT TO THE NORTHEAST AND QUICKLY RAMP UP TO 25-30
KTS AFTER MIDNIGHT SUNDAY NIGHT WITH STRONGER WINDS CONTINUING INTO
MIDDAY MONDAY. WINDS WILL DIMINISH MONDAY NIGHT INTO TUESDAY AS HIGH
PRESSURE SETTLES OVERHEAD. SOUTHEAST TO SOUTH WINDS INCREASE
WEDNESDAY INTO THURSDAY AHEAD OF THE NEXT LOW PRESSURE SYSTEM. WINDS
WILL BE STRONGEST OVER EASTERN HALF OF LK SUPERIOR.
WITH MORE MOIST AIR BEGINNING TO WORK NORTH OVER LAKE SUPERIOR...
THERE IS THE POTENTIAL FOR PATCHY/AREAS OF FOG OVER MAINLY NORTHERN
PORTIONS OF LAKE SUPERIOR LATER TONIGHT THROUGH SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
547 AM CDT SAT SEP 27 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 404 AM CDT SAT SEP 27 2014
UPPER LOW CENTERED NEAR DES MOINES THIS MORNING WILL BE MAIN
HEADACHE IN THE SHORT TERM. THIS LOW IS STILL WELL DETACHED FROM
THE MAIN FLOW...WHICH IS STILL WELL NORTH OF THE INTERNATIONAL
BORDER IN CANADA EAST OF THE ROCKIES. THIS WAVE WILL BE TAKING THE
SCENIC ROUTE ACROSS THE PLAINS...COMING UP INTO SRN MN THIS
AFTERNOON...BEFORE HEADING BACK TO THE SOUTHEAST TONIGHT INTO
SUNDAY. PERSISTENT MOIST SRLY FLOW HAS ALLOWED FOR PLENTY OF ACCAS
TO DEVELOP FROM IOWA UP INTO MN...WITH A COUPLE OF THUNDERSTORMS
PERSISTING THROUGH THE NIGHT UNDER THE CENTER OF THE LOW SOUTH OF
I-80 IN CENTRAL IA. REGIONAL RADAR IMAGERY THE PAST COUPLE OF HOURS
HAS SHOWED LIGHT ISOLATED RETURNS PULSING UP AND DOWN FROM NRN IA
INTO SRN MN. WE EXPECT THIS TREND OF ISOLATED SHOWERS TO CONTINUE
THROUGH THE DAY AS THE UPPER LOW SLOWLY LIFTS NORTH. PRECIP CHANCES
BY THE AFTERNOON WILL BE AIDED BY THE DEVELOPMENT OF 500-1500 J/KG
OF MLCAPE THAT THE NAM SHOWS DEVELOPING FROM SOUTH CENTRAL MN UP
INTO THE ST. CROIX VALLEY. THE CAMS ARE RELATIVELY QUIET WITH THE
DEVELOPMENT OF ANY SHOWERS OUTSIDE OF THE HRRR...BUT THE
GFS/ECMWF/GEM/SREF ALL SHOW SOME LIGHT QPF DEVELOPING UNDER THE
UPPER LOW WITHIN THE INSTABILITY PLUME...SO MAINTAINED THE SLIGHT
CHANCE POPS WE HAD GOING. THE VAST MAJORITY OF PEOPLE WILL GO
THROUGH THE DAY DRY...BUT FEEL THERE IS ENOUGH SUPPORT /ESPECIALLY
WITH WHAT WE HAVE SEEN IN IOWA OVERNIGHT/ TO CONTINUE THE ISOLATED
SHOWER MENTION. ONLY CHANGE MADE TO THESE POPS WAS TO PULL THEM OUT
OF THE NRN CWA...AS THESE SHOWERS LOOK TO REMAIN CLOSE TO THE UPPER
LOW.
VERY LITTLE CHANGE IN THE AIRMASS HAS HAPPENED OVERNIGHT...SO EXPECT
VERY SIMILAR CONDITIONS IN TERMS OF TEMPS/DEWPS/WINDS TO WHAT WAS
SEEN FRIDAY. AGAIN...BUFR SOUNDINGS SHOW MOST LOCATIONS MIXING UP TO
BETWEEN 850-825 MB. MIXING TO 825MB WORKED WELL FOR HIGHS
YESTERDAY...SO THE MAGIC BLEND USED FOR HIGHS TODAY WAS TO USE 2
PARTS MIX DOWN TEMPS TO 825MB...WITH 1 PART HIGHS FROM YESTERDAY.
THIS YIELDED HIGHS IN THE 80S FOR JUST ABOUT EVERYONE...ENJOY!
QUIET WEATHER IS EXPECTED FOR TONIGHT...WITH ONLY CLOUD COVER
EXPECTED TO BE A CONTINUATION OF SCT CLOUDS IN THE 5K TO 7K FT
RANGE. WE WILL SEE A COLD FRONT ENTER NW MN TONIGHT...BUT ALL PRECIP
ASSOCIATED WITH IT IS LOOKING TO BE POST FRONTAL. WILL BE A FEW
DEGREES COOLER SATURDAY NIGHT THOUGH...AS WINDS LOOK TO BE WEAKER
WITH A LITTLE LESS CLOUD COVER AS WELL...BUT LOWS WILL STILL BE A
GOOD 10 DEGREES ABOVE NORMAL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 404 AM CDT SAT SEP 27 2014
THE LONG TERM REMAINS AN ACTIVE PERIOD WITH MUCH BETTER AGREEMENT
WITH THE INDIVIDUAL FEATURES ON THE 27.00Z GFS/ECMWF RUNS ACROSS
THE UPPER MISSISSIPPI VALLEY. BETWEEN THE TWO...THE GFS HAS SHOWN
THE BEST CONSISTENCY OVER THE PAST FOUR NIGHTS WITH THE PROJECTED
UPPER AIR PATTERN FOR THE WEEK AHEAD.
A WEAK UPPER LOW WILL BE CENTERED OVER SOUTHERN MN SUNDAY MORNING
WITH THIS FEATURE DRIFTING SOUTHEAST DURING THE DAY. A DRY
FORECAST REMAINS IN PLACE WITH A FEW SHOWERS POSSIBLY DEVELOPING
OUTSIDE OF OUR NW CWA SUNDAY AFTERNOON AS A COLD FRONT APPROACHES
FROM THE NORTH. SUNDAY WILL BE ANOTHER WARM DAY WITH HIGHS IN THE
UPPER 70S TO LOWER 80S. AS IN THE SHORT TERM...MIX-DOWN FROM 825MB
WAS THE FOUNDATION FOR THE HIGH TEMPERATURE FORECAST.
A COLD FRONT WILL DRIFT SOUTHWARD ACROSS THE CWA SUNDAY NIGHT AND
EARLY MONDAY. THE FORCING AND DEEP LAYER MOISTURE REMAINS BEST
WELL TO OUR NORTHEAST WITH JUST SMALL POPS INDICATED ACROSS
CENTRAL MN AND ADJOINING PORTIONS OF WEST CENTRAL WI. HIGHS ON
MONDAY WILL BE MUCH COOLER ACROSS THE NORTHERN HALF OF THE FA WITH
HIGHS FROM 60 TO 70 FORECAST. HIGHS WILL BE IN THE LOWER TO MIDDLE
70S FOR SOUTHERN MN.
THE FIRST IN A SERIES OF SHORT WAVES WILL MOVE INTO THE CENTRAL PLAINS
ON TUESDAY AND THEN LIFT NORTHEAST ACROSS THE UPPER MISSISSIPPI
VALLEY TUESDAY NIGHT AND WEDNESDAY. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL ACCOMPANY THIS FEATURE WITH RAINFALL AMOUNTS
FROM A QUARTER TO HALF INCH POSSIBLE.
ONE BIG CHANCE WITH THE 27.00Z RUNS WAS WITH THE ECMWF BACKING
DOWN FROM PHASING ENERGY STREAMS TO OUR WEST FROM WEDNESDAY INTO
THURSDAY. THIS IS NOW PROJECTED TO BE OVER AND TO THE EAST OF US
FROM THURSDAY INTO FRIDAY...WHICH IS SIMILAR TO PREVIOUS RUNS OF
THE GFS. THIS PATTERN WILL LIKELY RESULT IN WIDESPREAD RAIN
AMOUNTS NEAR AN INCH FROM SOUTH CENTRAL MN THROUGH THE SOUTH METRO
AND ACROSS WEST CENTRAL WI WEDNESDAY NIGHT AND THURSDAY. BLENDED
POPS WERE RAISED TO ACHIEVE THE LIKELY STATUS.
YET ANOTHER SHORT WAVE AND COLDER AIR WILL FOLLOW ON FRIDAY.
SHOWER CHANCES REMAIN ACROSS THE REGION WITH HIGHS ONLY REACHING
THE MIDDLE 50S TO AROUND 60. IF THE TIMING HOLDS...HIGH PRESSURE
WILL BE OVER THE FA ON SATURDAY WITH MORNING LOWS IN THE 30S TO
LOWER 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 538 AM CDT SAT SEP 27 2014
SHRA/TSRA CONTINUE TO LIFT NORTH ACROSS IOWA AND WILL MOVE INTO MN
THIS MORNING. HRRR SHOWS ISO SHOWERS WORKING UP INTO THE TWIN
CITIES...BUT STILL APPEARS COVERAGE WILL BE PRETTY SPARSE AT
BEST...SO HAVE MAINTAINED DRY TAFS. SIMILAR DIURNAL INCREASE IS
EXPECTED WITH WINDS TODAY GIVEN SIMILAR PRESSURE GRADIENT TO
FRIDAY...BUT TONIGHT WE WILL LOSE THAT GRADIENT...WHICH MEANS WE
WILL HAVE TO START THINKING ABOUT FOG AGAIN. WITH HIGHS EXPECTED
TO GET INTO THE 80S...WILL TAKE QUITE A BIT OF WORK THROUGH
RADIATIONAL COOLING TO GET FOG FORMATION...BUT WI TERMINALS MAY
HAVE ISSUES...AS THEY WILL SEE AN INCREASE IN MOISTURE TODAY AND
WILL BE CLOSER TO THE SFC RIDGE...WHICH WILL BE PROTRUDING WEST
FROM THE GREAT LAKES. BESIDE THE WARM STARTING POINT
TONIGHT...THESE CLOUDS BETWEEN 5K AND 7K FT WILL LIKELY STILL BE
AROUND TONIGHT...ADDING ANOTHER LAYER OF UNCERTAINTY ON FOG
POTENTIAL. FOR NOW...HAVE SOME MVFR VIS RESTRICTION AT EAU/RNH.
KMSP...CAN NOT COMPLETELY RULE OUT A STRAY SHOWER THIS
AFTERNOON...BUT COVERAGE AND CONFIDENCE ARE BOTH STILL PLENTY LOW
ENOUGH TO KEEP THE TAF DRY. MAY ALSO HAVE TO WATCH FOR SOME VSBY
RESTRICTIONS SATURDAY MORNING...BUT GIVEN HOW WARM WE ARE EXPECTED
TO GET TODAY...WILL BE TOUGH TO GET VIS RESTRICTIONS GOING.
/OUTLOOK FOR KMSP/
SUN...VFR. WINDS S 10KTS.
MON...VFR. WINDS NE 5 KTS.
TUE...VFR. CHANCE MVFR/SHRA OVERNIGHT. WINDS SE 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS PENDLETON OR
831 AM PDT SAT SEP 27 2014
.SHORT TERM...THROUGH MONDAY. NO CHANGES PLANNED IN FORECAST. WRAP
AROUND MOISTURE FROM SLOW MOVING UPPER LOW IN NEVADA WILL CONTINUE
TO AFFECT THE AREA EAST OF WALLA WALLA...PENDLETON...AND JOHN
DAY. TEMPERATURES WILL CONTINUE COOLER IN THESE AREAS UNDER MORE
EXTENSIVE CLOUD COVER. REST OF AREA WILL HAVE NEAR NORMAL
TEMPERATURES...LIGHT WINDS...AND FREQUENT PERIODS OF SUNSHINE.
&&
.PREV DISC... /ISSUED 132 AM PDT SAT SEP 27 2014/
SHORT TERM...TODAY THROUGH MONDAY...UNSETTLED WEATHER WILL CONTINUE
TODAY AND MONDAY AS AN UPPER TROUGH MOVES ACROSS THE REGION. THE
OVERALL FLOW WILL BE SPLIT WITH A SUBTLE TROUGH OVER NORTHERN
WASHINGTON AND A CLOSED UPPER LOW OVER NORTHERN CALIFORNIA AND
SOUTHERN OREGON. THE MODELS ARE ADVERTISING WRAP AROUND MOISTURE ON
THE NORTH SIDE OF THE UPPER LOW TO MOVE INTO THE EAST AND SOUTHEAST
PORTION OF THE CWA TODAY THROUGH MONDAY. THE HRRR MODEL IS SHOWING
PRECIPITATION INCREASING FROM THE SOUTHEAST INTO THE EASTERN AND
NORTHEAST MOUNTAINS OF THE CWA TODAY. AS SUCH WILL KEEP A SLIGHT
CHANCE TO CHANCE POPS IN THE FORECAST FOR THE EASTERN AND SOUTHEAST
BORDER REGION OF THE CWA. THE ECMWF CONTINUES TO BE FURTHER TO THE
NORTH AND WEST WITH THE PRECIPITATION WHILE THE GFS SHOWS MUCH LESS.
IT WILL REMAIN DRY TODAY AND SUNDAY FOR THE REMAINDER OF THE CWA.
THEN ON MONDAY THE NEXT WEATHER SYSTEM BEGINS TO MOVE INTO THE
WASHINGTON CASCADES WITH SOME INCREASE IN PRECIPITATION THERE.
TEMPERATURES WILL REMAIN NEAR NORMAL THROUGH THE PERIOD AND WINDS
WILL BE FAIRLY LIGHT...WITH THE HIGHEST GUSTS OF 15-20 KTS IN THE
AFTERNOONS AND EARLY EVENING. 88
LONG TERM...MONDAY NIGHT THROUGH SATURDAY...A BROAD UPPER LEVEL
TROUGH WILL MOVE ACROSS THE REGION MONDAY NIGHT AND TUESDAY WITH A
SLIGHT CHANCE FOR MAINLY MOUNTAIN SHOWERS AND BREEZY WINDS. A COOL
PRIMARILY DRY NW FLOW WILL WILL FOLLOW FOR WEDNESDAY AND THURSDAY AS
AN UPPER LEVEL RIDGE AMPLIFIES OFFSHORE. AS THE RIDGE MOVES OVER THE
AREA FOR FRIDAY AND SATURDAY...WARMING TEMPERATURES ARE EXPECTED. IT
SHOULD REMAIN MOSTLY DRY. THE ECMWF DOES SHOW A DISTURBANCE PASSING
TO THE NORTH OF THE REGION WITH PRECIPITATION IN WASHINGTON. FOR NOW
HAVE KEPT THE FORECAST AREA DRY EXCEPT FOR SLGT CHC POPS WA CASCADE
CREST. TEMPERATURES WILL START OUT NEAR TO SLIGHTLY BELOW NORMAL BUT
END UP ABOVE NORMAL BY FRIDAY AND SATURDAY. IT WILL BE QUITE COLD IN
THE MOUNTAIN VALLEYS WITH WIDESPREAD FREEZING TEMPERATURES. 78
AVIATION...12Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH 12Z
SUNDAY. MID AND HIGH CLOUDS ARE EXPECTED AT THE EASTERN TAF SITES
WITH MOSTLY CLEAR SKIES AT THE WESTERN SITES AS AN UPPER LEVEL LOW
PRESSURE SYSTEM MOVES TO OUR SE. WINDS WILL INCREASE FROM THE NW-N
THIS AFTERNOON AT 10-20 KT AND DIMINISH THIS EVENING. 78
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 71 52 72 52 / 10 10 10 10
ALW 74 55 74 56 / 10 10 10 10
PSC 77 53 77 52 / 0 10 10 10
YKM 74 51 76 49 / 10 0 0 10
HRI 76 50 76 50 / 10 10 10 10
ELN 72 49 73 48 / 10 0 0 10
RDM 66 39 68 39 / 10 10 10 10
LGD 67 45 68 45 / 20 20 20 20
GCD 66 44 68 43 / 20 20 20 20
DLS 75 53 77 54 / 10 10 10 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
79/89/89
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1002 AM CDT SAT SEP 27 2014
.MORNING UPDATE...
REMOVED MORNING FOG WORDING FROM THE GRIDS/ZONES. MOST OF THE
FORECAST SEEMS TO BE ON TRACK THEREAFTER. HOWEVER...THE HRRR AND
OTHER WRF MODELS SHOW SOME AFTERNOON SHOWERS DEVELOPING ACROSS
SOUTHERN MIDDLE TN. RIGHT NOW LAPS SOUNDINGS HAVE US CAPPED AROUND
600MB BUT COULD SEE SOME SHALLOW SHOWERS DEVELOP GIVEN THE STEEP
LAPSE RATES BELOW THAT. THUS INSERTED A SLIGHT CHC OF SHOWERS OVER
THE FAR SOUTH THIS AFTERNOON. ONLY MINOR CHANGES MADE ELSEWHERE.
UPDATE ALREADY SENT.
&&
.PREV DISCUSSION... /ISSUED 709 AM CDT SAT SEP 27 2014/
UPDATE...FOR 12Z AVIATION FORECAST
AVIATION...
LOW LEVEL MOISTURE BEGINNING TO STREAM NORTHWARD UP THROUGH
ALABAMA...GEORGIA INTO SOUTHEAST MIDDLE TENNESSEE AND ALONG THE
SOUTH END OF THE CUMBERLAND PLATEAU...WHERE STRATOCUMULUS EVIDENT
IN LATEST 11U-3.9 MICRON SATELLITE LOOP. WITH CROSSVILLE ALREADY
BROKEN AM EXPECTING NASHVILLE AND CLARKSVILLE TO GO BROKEN BY 18Z
BUT REMAIN IN THE VFR RANGE NEXT 24 HOURS. CROSSVILLE LIKELY TO
BOUNCE BETWEEN MVFR AND VFR OVER THE NEXT 24 HOURS AS MOISTURE
CONTINUES TO STREAM NORTHWARD. THINK FOR THE MOST PART ANY SHOWERS
WILL HOLD OFF AT THE TERMINAL SITES UNTIL AFTER 12Z SUNDAY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AL
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1129 AM CDT SAT SEP 27 2014
.DISCUSSION...
CLOUD COVER RAPIDLY OVERTAKING THE REGION THIS MORNING...AS A
PAIR OF UPPER DISTURBANCES /ONE OVER S TX AND THE OTHER OVER THE
ERN HIGH PLAINS/ CONTINUE TO INCH EWD. MODELS NOT SHOWING MUCH EWD
MOVEMENT ON THE SRN LOW UNTIL TONIGHT/SUNDAY...BUT WV IMAGERY
SEEMS TO INDICATE THAT IT IS ALREADY MAKING A MOVE. THIS COULD
BRING A FEW SHWRS...SO 20 POPS HAVE BEEN MAINTAINED. 24-HOUR TEMP
TRENDS A FEW DEGREES ON THE NEGATIVE SIDE OVER PARTS OF E
TX...LIKELY DUE TO CLOUD COVER. HAVE ADJUSTED DOWN OVER THESE
AREAS AND LEFT THE REMAINDER OF THE AREAS AS IS. HAVE ALSO MADE A
FEW TWEAKS TO THE SKY GRIDS. OTHERWISE...GRIDS ARE IN GOOD SHAPE. /12/
&&
.PREV DISCUSSION... /ISSUED 711 AM CDT SAT SEP 27 2014/
AVIATION...
EXPECTING VFR FLIGHT CATEGORIES FOR TERMINAL SITES ACROSS THE ARKLATEX
THROUGH THE FORECAST PERIOD ENDING 28/12Z. MAINLY HIGH AND MIDDLE CLOUDS
SPREADING OVER THE REGION WITH SOME LIGHT SPRINKLES FROM SOME OF THE
MIDDLE LEVEL CLOUDS TODAY AND INTO THE EVENING WITH INFLUENCE FROM AN
UPPER LEVEL DISTURBANCE SHIFTING INTO THE REGION. SCATTERED TO
BROKEN CUMULUS CLOUDS AROUND 4-5 KFT DEVELOPING DURING THE DAY AND
LINGERING INTO THE OVERNIGHT HOURS. WINDS NORTHEAST TO EAST 5-10
KNOTS. /06/
PREV DISCUSSION... /ISSUED 530 AM CDT SAT SEP 27 2014/
DISCUSSION...
PARTLY TO MOSTLY CLOUDY SKIES WITH LOTS OF TEMPERATURES RANGING IN
THE 60S...BUT THERE ARE A FEW UPPER 50S NORTH OF I-30. OUR DEW
POINTS ARE COMING UP A BIT...BUT STILL A GOOD SPREAD WITH NO FOG
ISSUES EXCEPT AT THE COOLER SITE IN DE QUEEN. LAST NIGHT/S
SOUNDING IS RIGHT AT AN INCH OF PWAT AND THERE ARE A FEW SHOWERS
ARE SHOWING UP ON THE SHV 88D JUST OUTSIDE OF OUR CWA. THE RADAR
HAS BEEN OUT OF CLEAR AIR AND IN PRECIP MODE FOR MORE THAN A HALF
HOUR NOW WITH RAIN ON THE GROUND OUT OF MOSTLY MID DECK FROM SAT
TO ATT. THE UPPER LOW OVER THE RIO GRANDE IS BEING KICKED OUT A
BIT THIS MORNING BY THE LONG WAVE OVER THE WEST COAST. THE TEXAS
LOW IS IN FUJIWHARA MODE WITH THE MIDWEST LOW ALL ROTATING UNDER
THE BIG RIDGE OVER THE NORTHERN TIER AND SE CANADA. THE DIGGING
UPPER LOW OVER CALIFORNIA IS STILL TRYING TO MOVE SE...BUT APPEARS
TO HAVE MORE AN EASTWARD PUSH. AS THE LOW TO OUR SW CONTINUES TO
ROTATE UNDER THE MID WEST LOW IS SHOULD CONTINUE EASTWARD INTO OUR
PERIOD OF HEATING AND EDGE EASTWARD OVERNIGHT WHILE WASHING OUT ON
THE RIDGE. A MIX OF SHOWERS AND ISOLATED THUNDERSTORMS SHOULD
RESULT DESPITE LIMITED MODEL QPF.
THE HRRR WAS THE MOST INTERESTING AND WAS THE MODEL OF CHOICE FOR
TODAY. THE NAM WAS THE WARMEST AND MOS PERHAPS TOO COOL SO WE HAVE
SETTLED SOMEWHERE IN BETWEEN IN OUR FORECAST. THE MODELS REALLY DO
NOT PICK ON MUCH OF ANY QPF AND MAY PLAY CATCH UP WITH THIS NEXT
RUN FOLLOWING OUR ASCENT IN THE COMING HOUR.
AT ANY RATE THE FORECAST CONTINUES AS PLANNED WITH MORE TYPICALLY
DRY LATE SUMMER READINGS IN THE COMING DAYS. THE MEX IS LOOKING AT
A COUPLE OR FEW DAYS OF LOWER 90S. THE NEXT REAL DEAL COLD FRONT
IS MODELED WELL ON THE GFS AND IS OUR MODEL OF CHOICE FOR THE LONG
RANGE WITH NORTHERLY WINDS FILTERING IN LATE IN THE WEEK FOR A
FANTASTIC FOOTBALL FRIDAY NIGHT. HOPEFULLY THE WPC 1 TO TWO INCH
RAIN FOR OUR AREAS HOLDS TRUE OTHERWISE WE MAY BE LOOKING AT MORE
BURN BANS FOR THE FALL SEASON. /24/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 86 66 89 66 89 / 20 20 10 10 10
MLU 86 66 85 64 87 / 10 20 20 10 10
DEQ 85 63 86 61 87 / 10 10 10 10 10
TXK 85 64 86 63 87 / 20 10 10 10 10
ELD 85 63 86 62 86 / 10 20 10 10 10
TYR 85 66 88 65 88 / 20 10 10 10 10
GGG 86 65 88 63 89 / 20 10 10 10 10
LFK 86 66 89 65 91 / 20 10 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
12
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
349 PM EDT SAT SEP 27 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 347 PM EDT SAT SEP 27 2014
...ONE MORE UNSEASONABLY WARM DAY IN STORE FOR SUNDAY...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A STRONG RIDGE OVER MUCH
OF THE E HALF OF THE CONUS. 585-588 DECAMETER 5H HIGHS OVER THE UPPER
GREAT LAKES HAVE RESULTED IN INLAND HIGH TEMPS IN THE UPPER 70S TO
LOWER 80S ACROSS MUCH OF THE FORECAST AREA THIS AFTERNOON UNDER
MOSTLY SUNNY SKIES.
ANOTHER QUIET/CLEAR NIGHT IS EXPECTED TONIGHT UNDER THE INFLUENCE OF
THE HIGH PRESSURE RIDGE. MIN TEMPS SHOULD BE A LITTLE BIT HIGHER
THAN SATURDAY MORNINGS MINS DUE TO SOME INCREASE IN PRECIPITABLE
WATER. EXPECT MORE SHALLOW FOG FORMATION MAINLY WELL INLAND FROM
LAKE SUPERIOR. DOWNSLOPING SOUTHERLY WIND AND ASSOC MIXING SHOULD
GENERALLY PROHIBIT FOG FORMATION NEAR LAKE SUPERIOR.
EXPECT ONE MORE UNSEASONABLY WARM DAY ON SUNDAY. MIXING 850 MB OF
13-14C TO SFC SHOULD AGAIN YIELD HIGH TEMPS MAINLY IN THE UPPER 70S
AND LOWER 80S. ONSHORE SOUTH WINDS WILL RESULT IN COOLER TEMPS
AROUND 70S ALONG THE LAKE MI SHORELINE. KEPT IN SLIGHT CHC POPS FOR
SHRA OVER THE NCNTRL FCST AREA WHERE MODELS HINT THAT DEVELOPMENT OF
LAKE BREEZE OFF LAKE BREEZE COULD PROVIDE FOCUS FOR ISOLD
CONVECTION. MODIFIED NAM SOUNDINGS FOR 78/58 YIELD SBCAPE 200-300
J/KG WITH MINIMAL CIN.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 347 PM EDT SAT SEP 27 2014
A MORE ACTIVE AND TYPICAL FALL PATTERN WILL AFFECT THE AREA THROUGH
THE UPCOMING WEEK...WITH SIGNIFICANTLY COOLER WEATHER FOR MONDAY AND
EARLY NEXT WEEKEND.
SUNDAY NIGHT AND MONDAY...A SHORTWAVE TROUGH OVER MANITOBA WILL BE
INTERACTING WITH A RESIDUAL SFC TROUGH/COLD FRONT STRETCHING FROM
NORTH DAKOTA TO JUST NORTH OF LAKE SUPERIOR SUNDAY EVENING. MODEL
GUIDANCE HAD BEEN RATHER INCONSISTENT WITH THE STRENGTH AND TIMING
OF THE FRONT OVER THE PAST COUPLE DAYS...BUT SOME OF THE 12Z RUNS
TODAY APPEAR TO BE CONVERGING ON A SOLUTION. THE RECENT NAM AND GEM
RUNS ARE ADVERTISING A SHARPER TROUGH AXIS AND QUICKER PASSAGE MORE
IN LINE WITH THE ECMWF OVER THE PAST COUPLE DAYS. HAD ORIGINALLY
THOUGHT GUIDANCE WAS TRENDING SLOWER WITH YESTERDAYS RUNS...BUT AM
NOW MORE CONVINCED OF THE FASTER SOLUTION GIVEN THE ECMWF
PERSISTENCE. FRONTAL PASSAGE TIME LOOKS TO BE AROUND 00Z MONDAY
ALONG LAKE SUPERIOR. THE FRONT WILL CONTINUE SOUTHWARD THROUGH THE
NIGHT...CLEARING THE SOUTH CENTRAL AND EAST CWA SHORTLY AFTER 12Z
MONDAY.
ACTIVE LOW-LEVEL FGEN COMBINED WITH THE SHARP TROUGH AXIS WILL ALLOW
FOR DECENT PRECIP COVERAGE ALONG THE FRONT. THE ONE LIMITING FACTOR
TO MORE WIDESPREAD COVERAGE WILL BE LESSENING UPPER-LEVEL SUPPORT AS
THE RIGHT-ENTRANCE OF THE JET SHIFTS EASTWARD. THIS WILL KEEP THE
BEST COVERAGE ACROSS EASTERN LAKE SUPERIOR AND UPPER MI. ONLY MADE
SOME SMALL CHANGES TO THE POPS FOR MONDAY...KEEPING LIKELY POPS
CONFINED TO MAINLY THE NORTHEAST HALF OF THE CWA. IN THE MORNING AND
ALONG NE UPSLOPE AREAS OF LAKE SUPERIOR. BLUSTERY NE WINDS WILL
COMMENCE BEHIND THE FRONT ACROSS THE NORTH HALF. HIGHS TEMPS MONDAY
WILL BE IN THE MORNING FOR MUCH OF THE CWA....WITH TEMPS NORTHWEST
IN THE 40S AND SOUTHEST IN THE 50S BY THE AFTERNOON.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE FRONTAL PRECIP WILL CLEAR
THE CWA BY MONDAY EVENING WHILE MID-LEVEL RIDHING SHIFT ACROSS THE
UPPER GREAT LAKES AND A SFC HIGH BUILDS ACROSS NORTHERN ONTARIO AND
QUEBEC. THE AREA SHOULD REMAIN SOCKED IN WITH LOW CLOUDS THROUGH THE
NIGHT GIVEN PLENTY OF RESIDUAL LOW-LEVEL MOISTURE AND A DECENT
SUBSIDENCE INVERSION. CONTINUED NE UPSLOPE FLOW COMBINED WITH THE
MOISTURE WILL RESULT IN LINGER SHOWERS/DRIZZLE CENTRAL AND EAST
ALONG LAKE SUPERIOR THROUGH THE NIGHT. HOW LONG IT TAKES TO RID
THESE CLOUDS ON TUESDAY IS IN QUESTION. MORNING INVERSION
HEIGHTS OF 2-3KFT WILL TRAP REMAINING LOW-LEVEL MOISTURE BEFORE
MIXING AND THE ARRIVAL OF SOMEWHAT DRIER LOW-LEVEL AIR HELP ERODE
CLOUDS THROUGHOUT THE DAY. CLOUDS WOULD LIKELY REMAIN ACROSS THE
EAST LONGER GIVEN THE CLOSER PROXIMITY TO MOIST NE FLOW FROM THE
MOISTURE POOL.
WEDNESDAY THROUGH THURSDAY...DEEP TROUGHING OVER THE ROCKIES WILL BE
SHIFTING NORTHEASTWARD ACROSS THE NORTHERN PLAINS BY WEDNESDAY. A
LEAD SHORTWAVE WILL BE TRACKING ACROSS MANITOBA AS AN ASSOCIATED SFC
LOW SEND A COLD FRONT EASTWARD ACROSS THE UPPER MS VALLEY. THE FRONT
WILL BE ON THE DOORSTEP OF THE WESTERN CWA 12Z WEDNESDAY. WITH THE
MID-LEVEL RIDGE STILL OVER THE LOWER GREAT LAKES...INITIAL MID AND
UPPER-LEVEL SUPPORT WILL BE MARGINAL. THEREFORE...PRECIP COVERAGE
SHOULD BE MINIMAL WITH THE FRONT ON WEDNESDAY.
A QUICK-MOVING SHORTWAVE OVER BRITISH COLUMBIA WEDNESDAY WILL
REINFORCE THE DEEP TROUGH OVER THE NORTHERN PLAINS. COMBINED WITH
THE APPROACH OF THE RIGHT ENTRANCE OF AN UPPER JET AND INCREASING
LOW TO MID-LEVEL FGEN...THIS SHOULD ALLOW FOR A SUBSTANTIAL INCREASE
IN PRECIP COVERAGE ON THURSDAY AND THURSDAY NIGHT. THE ECMWF IS A
TOUCH SLOWER WITH THE TROUGH AND MORE WIDESPREAD WITH PRECIP THAN
THE GFS...BUT CONFIDENCE IS HIGH ENOUGH TO INTRODUCE LIKELY POPS
ACROSS THE WEST HALF THURSDAY AND THE EAST HALF THURSDAY NIGHT.
THURSDAY NIGHT THROUGH SATURDAY...MODEL SOLUTIONS DIVERGE AFTER
THURSDAY NIGHT AS THE GFS FORMS A STRONG LOW OVER LAKE HURON WHILE
THE ECMWF FORMS THE LOW CLOSER TO HUDSON BAY. EITHER WAY...THE
OVERALL PICTURE IS A SERIES OF RAW...CHILLY FALL DAYS BEGINNING ON
FRIDAY WITH BLUSTERY NW WINDS AND PLENTY OF WRAP-AROUND MOISTURE
BEHIND THE SYSTEM TO THE EAST. IN ADDITION...THE MID-LEVEL TROUGH
AXIS WILL REMAIN WEST OF THE AREA THROUGH FRIDAY...SO HAVE INCREASED
PRECIP CHANCES FOR FRIDAY. THIS IS ESPECIALLY TRUE ALONG LAKE
SUPERIOR WITH INCREASED LAKE MOISTURE AND UPSLOPE SUPPORT. THE
ARRIVAL OF 850 HPA TEMPS OF -3 TO -1C WILL SUPPORT SOME LAKE EFFECT
RAIN SHOWERS AS SFC-H8 DELTA T VALUES INCREASE TO AROUND 10C. THE
COOLEST WIDESPREAD TEMPS OF THE SEASON ARE ALSO EXPECTED AS HIGHS
STRUGGLE TO GET OUT OF THE 40S...A STARK DIFFERENCE FROM HIGHS IN
THE 70S THIS SATURDAY/TODAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 251 PM EDT SAT SEP 27 2014
DRY AIR ASSOCIATED WITH HIGH PRES CENTERED NEAR LAKE HURON WILL
CONTINUE TO BRING PREVAILING VFR CONDITIONS TO KIWD/KCMX/KSAW THRU
THIS FCST PERIOD. HOWEVER...AS HAS BEEN THE CASE THE LAST FEW
NIGHTS...SHALLOW RADIATIONAL FOG WILL DEVELOP AT NIGHT AND AFFECT
KSAW. LOW-LEVEL WINDS TONIGHT WILL HAVE MORE OF A DOWNSLOPE WESTERLY
COMPONENT...SO AT THIS POINT...NOT ANTICIPATING KSAW TO DROP BLO MVFR
LATE TONIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 347 PM EDT SAT SEP 27 2014
LIGHT WINDS PERSIST THROUGH SUNDAY...THEN CHANGES ARE EXPECTED BY
MONDAY MORNING AS A FRONT WORKS NORTH TO SOUTH ACROSS LK SUPERIOR.
EXPECT WINDS TO SHIFT TO THE NORTHEAST AND QUICKLY RAMP UP TO 25-30
KTS AFTER MIDNIGHT SUNDAY NIGHT WITH STRONGER WINDS CONTINUING INTO
MIDDAY MONDAY. WINDS WILL DIMINISH MONDAY NIGHT INTO TUESDAY AS HIGH
PRESSURE SETTLES OVERHEAD. SOUTHEAST TO SOUTH WINDS INCREASE
WEDNESDAY INTO THURSDAY AHEAD OF THE NEXT LOW PRESSURE SYSTEM. WINDS
WILL BE STRONGEST OVER EASTERN HALF OF LK SUPERIOR. WHILE THERE IS
STILL UNCERTAINTY IN TIMING...AN EXTENDED NW GALE EVENT WILL BE
POSSIBLE SOMETIME FRIDAY INTO SATURDAY MORNING.
WITH MORE MOIST AIR BEGINNING TO WORK NORTH OVER LAKE SUPERIOR...
THERE IS THE POTENTIAL FOR PATCHY/AREAS OF FOG OVER MAINLY NORTHERN
PORTIONS OF LAKE SUPERIOR LATER TONIGHT THROUGH SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KLUBER
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
252 PM EDT SAT SEP 27 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM EDT SAT SEP 27 2014
...ANOTHER UNSEASONABLY WARM LATE SEPT DAY IS ON THE WAY TODAY...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A STRONG RIDGE OVER MUCH
OF THE E HALF OF THE CONUS. CORE OF THE POSITIVE ANOMALIES WITH THE
RIDGE IS OVER NRN ONTARIO WHERE ANOMALIES ARE 2.5 STANDARD
DEVIATIONS ABOVE THE LONG TERM LATE SEPT AVG. WITHIN THE RIDGE...A
WEAK MID LEVEL LOW CENTERED ROUGHLY ALONG THE IA/MO BORDER IS
GENERATING ISOLD SHRA/TSRA OVER IA INTO SW MN. CLOSER TO HOME...THE
WEATHER REMAINS QUIET. TYPICAL FOR THIS TIME OF YEAR WITH THIS TYPE
OF WEATHER PATTERN THAT FEATURES QUIET/CLEAR NIGHTS...SHALLOW FOG
HAS AGAIN FORMED...MAINLY OVER SCNTRL AND ERN UPPER MI AND
ESPECIALLY NEAR RIVERS/LAKES/STREAMS.
WITH LITTLE OVERALL CHANGE IN AIR MASS TODAY COMPARED TO YESTEDAY...
TODAY WILL BE A CARBON COPY OF YESTERDAYS WEATHER. MIXING TO
AROUND 850MB SUPPORTS MAX TEMPS WELL INTO THE 70S TO THE LWR 80S
AWAY FROM LAKE MODERATION WHICH SHOULD BE CONFINED MAINLY TO AREAS
NEAR LAKE MICHIGAN. GIVEN THE SIMILAR AIR MASS CHARACTERISTICS...
SIMPLY USED YESTERDAYS OBSERVED MAX TEMPS FOR TODAYS FCST WITH A FEW
MINOR ADJUSTMENTS. DIURNAL TEMP RISE SHOULD BE NEARLY IDENTICAL TO
YESTERDAYS AS WELL...SO UTILIZED YESTERDAYS DIURNAL TEMP CURVE FOR
HOURLY TEMPS. SHALLOW FOG WILL QUICKLY DISSIPATE AFTER SUNRISE.
ANOTHER QUIET/CLEAR NIGHT IS EXPECTED TONIGHT. MIN TEMPS SHOULD BE A
LITTLE HIGHER THAN THIS MORNINGS MINS DUE TO SOME INCREASE IN
PRECIPITABLE WATER. SHALLOW FOG SHOULD MAKE ANOTHER APPEARANCE IN
GENERALLY THE SAME AREAS THAT IT HAS APPEARED IN RECENT NIGHTS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 354 AM EDT SAT SEP 27 2014
GOOD AGREEMENT IN OVERALL LOOK OF LARGER SCALE PATTERN INTO NEXT
WEEK. MAIN ISSUE REMAINS TIMING OF FRONT ON SUNDAY NIGHT INTO
MONDAY. ECMWF HAS STEADILY TRENDED TOWARD QUICKER FROPA ON SUNDAY
NIGHT WITH NNE WINDS OVER ALL OF UPR MICHIGAN BY 12Z MONDAY. NAM AND
GFS NOT AS AGGRESSIVE AND TREND FROM GFS IS MAINLY SLOWER...THOUGH
00Z RUN IS FARTHER SOUTH WITH FRONT BUT KEEPS MOST RAIN OUT OF CWA
UNTIL AFTER 12Z MONDAY. DIFFERENCES IN TIMING OF FROPA IS TIED TO
HOW MUCH JET ENERGY DIGS INTO BACKSIDE OF SHORTWAVE TROUGH CROSSING
NORTHERN ONTARIO. ECMWF SHOWS STRONGER JET/MORE AMPLFIED TROUGH
WHILE GFS AND GEM-NH SHOW MORE OF THE JET ENERGY AHEAD OF THE TROUGH
AND THUS A FLATTER MORE PROGRESSIVE TROUGH ALOFT. TOUGH TO SAY WHICH
IDEA IS RIGHT. MORE AMPLIED IDEA SEEMS GOOD AS MAIN SHORTWAVE
CURRENTLY OVER NORTHERN ALBERTA IS QUITE SHARP PER WV LOOP AND 00Z
RAOBS...BUT A MORE STRUNG OUT SHORTWAVE COULD ALSO OCCUR AS THE
RIDGE IT WILL BE DROPPING TOWARDS IS UNSEASONABLY STRONG WITH
590DAM HEIGHTS FM DAKOTAS OVER NORTHERN ONTARIO AND OVER SOUTHERN
QUEBEC AND LOWER GREAT LAKES.
CONSENSUS OF ALL MODELS AND THE CURRENT FORECAST POINTS TO FROPA LATE
SUNDAY NIGHT INTO MONDAY MORNING. WILL HEAD THIS WAY AS WELL. RESULT
WILL BE INCREASING RAIN CHANCES INTO MONDAY...LIKELY TURNING INTO
MORE OF A STRATIFORM RAIN BOOSTED BY H7-H5 Q-VECTOR CONVERGENCE WITH
THE SHORTWAVE AND ADDITIONAL LIFT WITHIN RIGHT ENTRANCE REGION OF JET
STREAK FM NORTHERN ONTARIO TO QUEBEC. SHALLOW COOL/MOIST FLOW
UPSLOPING INTO HIGHER TERRAIN NEAR LK SUPERIOR ONLY ADDS TO THE RAIN
CHANCES. TEMPS WILL EXHIBIT SHARP GRADIENT BTWN WHERE THE SUB H9 FLOW
IS STIFF ONSHORE AND WHERE MIXING TO H9 AND OFFSHORE WINDS WILL ALLOW
FOR TEMPS TO REACH NEAR 70 OVER THE SCNTRL. RAIN SHOULD DIMINISH TO
PROBABLY AREAS OF DRIZZLE LATER MONDAY NIGHT AS HIGH
PRESSURE/ANTICYCLONIC FLOW ADVANCES FURTHER INTO THE AREA. COOL TEMPS
PERSIST INTO TUESDAY...ESPECIALLY NEAR LK SUPERIOR WHERE WINDS STAY
ONSHORE ALL DAY.
RIDGING BUILDS BACK ALOFT BY WEDNESDAY AS TROUGHING EXPANDS OVER
WESTERN CONUS. WEDNESDAY WILL BE AN IN BTWN DAY AND COULD SEE AT
LEAST SOME SUNSHINE...AT LEAST IN THE EAST HALF. HIGH TEMPS WARMING
BACK INTO THE 60S AND POSSIBLY...WITH ENOUGH SUNSHINE...TOUCHING 70
DEGREES. LEADING SHORTWAVE EMERGING FM WEST CONUS TROUGH COULD BRING
SOME SHOWERS TO PARTS OF CWA BY WEDNESDAY EVENING. GREATEST CHANCES
OF RAIN LIKELY HOLD OFF TIL THURSDAY AS STRONGER FORCING ALOFT
COMBINES WITH MORE OF A LOW-LEVEL FRONTAL BOUNDARY. MODEL CONSISTENCY
IS SHAKY SO WILL NOT ALTER THE CONSENSUS POPS. INCLUDED SMALL CHANCES
FOR THUNDER ON THURSDAY AS THERE IS AT LEAST A BRIEF INTERLUDE OF
INSTABILITY WORKING ACROSS THE REGION AHEAD OF THE FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 251 PM EDT SAT SEP 27 2014
DRY AIR ASSOCIATED WITH HIGH PRES CENTERED NEAR LAKE HURON WILL
CONTINUE TO BRING PREVAILING VFR CONDITIONS TO KIWD/KCMX/KSAW THRU
THIS FCST PERIOD. HOWEVER...AS HAS BEEN THE CASE THE LAST FEW
NIGHTS...SHALLOW RADIATIONAL FOG WILL DEVELOP AT NIGHT AND AFFECT
KSAW. LOW-LEVEL WINDS TONIGHT WILL HAVE MORE OF A DOWNSLOPE WESTERLY
COMPONENT...SO AT THIS POINT...NOT ANTICIPATING KSAW TO DROP BLO MVFR
LATE TONIGHT. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 AM EDT SAT SEP 27 2014
LIGHT WINDS PERSIST THROUGH SUNDAY...THEN CHANGES ARE EXPECTED BY
MONDAY MORNING AS A FRONT WORKS NORTH TO SOUTH ACROSS LK SUPERIOR.
EXPECT WINDS TO SHIFT TO THE NORTHEAST AND QUICKLY RAMP UP TO 25-30
KTS AFTER MIDNIGHT SUNDAY NIGHT WITH STRONGER WINDS CONTINUING INTO
MIDDAY MONDAY. WINDS WILL DIMINISH MONDAY NIGHT INTO TUESDAY AS HIGH
PRESSURE SETTLES OVERHEAD. SOUTHEAST TO SOUTH WINDS INCREASE
WEDNESDAY INTO THURSDAY AHEAD OF THE NEXT LOW PRESSURE SYSTEM. WINDS
WILL BE STRONGEST OVER EASTERN HALF OF LK SUPERIOR.
WITH MORE MOIST AIR BEGINNING TO WORK NORTH OVER LAKE SUPERIOR...
THERE IS THE POTENTIAL FOR PATCHY/AREAS OF FOG OVER MAINLY NORTHERN
PORTIONS OF LAKE SUPERIOR LATER TONIGHT THROUGH SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...VOSS
MARINE...JLA
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
310 PM CDT SAT SEP 27 2014
.SYNOPSIS...
ISSUED AT 310 PM CDT SAT SEP 27 2014
AT 19Z...WATER VAPOR IMAGERY SHOWED A DEEP TROUGH OVER THE WEST
COAST WITH A CLOSED LOW CENTERED OVER CENTRAL CALIFORNIA. MOISTURE
STREAMED NORTHWARD ON THE DOWNSTREAM SIDE OF THE TROUGH WHERE LOTS
OF CLOUD COVER AND THUNDERSTORMS WERE OBSERVED FROM ARIZONA INTO
MONTANA. STRONG RIDGING WAS IN PLACE ACROSS THE REMAINDER OF THE
COUNTRY WHILE A CUTOFF UPPER LOW SPUN OVER WESTERN IOWA.
TEMPERATURES ACROSS THE PLAINS HAVE SOARED TO WELL ABOVE NORMAL
LEVELS AS WARM AIR STREAMS NORTH UNDER THE RIDGE. BY EARLY
AFTERNOON...READINGS IN THE LOW TO MID 80S WERE COMMON FOR MUCH OF
THE DAKOTAS THROUGH THE SOUTHERN PLAINS...WITH LOCAL AREAS RANGING
FROM 80 TO 85 DEGREES.
SLIGHTLY COOLER AIR ALOFT WAS OBSERVED FROM THE VICINITY OF THE IOWA
UPPER LOW DOWN INTO TEXAS. THIS LED TO STEEPER LAPSE RATES...AND
THEREFORE HAVE OBSERVED DECENT CUMULUS FIELD DEVELOP THIS
AFTERNOON.
THE UPPER LEVEL LOW ACROSS CA/NV THIS AFTN WILL LIFT THROUGH THE
ROCKIES AND INTO THE NRN PLAINS BY TUESDAY. A STRONG PACIFIC FRONT
WILL SWEEP THE FCST AREA MONDAY NIGHT AND TUESDAY PRODUCING HEAVY
RAIN ACROSS WRN NEB WITH LIGHTER AMOUNTS EAST. COOLER WEATHER
PREVAILS WEDNESDAY THROUGH SATURDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 310 PM CDT SAT SEP 27 2014
THE UPPER LOW OVER IOWA WILL STAY FAIRLY STATIONARY OR MAY EVEN
MEANDER WESTWARD SLIGHTLY TONIGHT. MODELS ARE SHOWING A WEAK IMPULSE
OF ENERGY ROTATING AROUND THE LOW...WHICH WOULD MOVE ACROSS THE
NORTHEAST PART OF THE FORECAST AREA AFTER 06Z TONIGHT. AT THE SAME
TIME...IT IS PROJECTED THAT THE LOW LEVEL JET WILL BE VEERING TO THE
NORTHEAST INTO THIS SAME AREA WHICH COULD BRING ENOUGH LIFT TO
DEVELOP SOME SHOWERS LATE TONIGHT AND EARLY SUNDAY MORNING.
TIME-FRAME LOOKS TO BE 09Z TO 15Z CURRENTLY. BELIEVE THERE WILL BE
DEVELOPMENT IN A NORTH TO SOUTH LINE SOMEWHERE FROM NORTH CENTRAL
INTO CENTRAL NEBRASKA. CONFIDENCE ISN/T REAL HIGH THOUGH IN
PLACEMENT AND AS COVERAGE WILL LIKELY BE ISOLATED TO
SCATTERED...HAVE SLIGHT CHANCES FOR SHOWERS IN THE FORECAST
CURRENTLY.
ALSO LOOKING AT POTENTIAL FOR FOG TONIGHT OVER THE WESTERN PART OF
THE FORECAST AREA. THE NAM IS HIGHLIGHTING A STRONG INCREASE IN LOW
LEVEL MOISTURE MAINLY WEST OF HIGHWAY 83 WHILE THE GFS IS FURTHER
EAST. THAT BEING SAID...THE RAP KEEPS MINIMAL LOW LEVEL MOISTURE
OVER THE LOCAL AREA...AS IT KEEPS THE POTENTIAL BETTER OVER WESTERN
KANSAS. THESE DIFFERENCES MAINLY RELY ON THE PLACEMENT OF THE
SURFACE LOW. WITH LOWER CONFIDENCE...HAVE NOT ADDED FOG INTO THE
FORECAST AT THIS TIME...BUT WILL PASS ON POTENTIAL TO ONCOMING
SHIFT.
LOOKING THEN INTO SUNDAY...WITH THE THOUGHT THAT ANY FOG AND/OR
CLOUD COVER THAT MAY LINGER INTO THE MORNING HOURS WILL QUICKLY
DISSIPATE...TEMPERATURES ALOFT WILL BE SIMILAR TO TODAY...AND WITH
DEEP MIXING EXPECTED...SHOULD ONCE AGAIN SEE HIGHS IN THE 80S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 310 PM CDT SAT SEP 27 2014
SUNDAY NIGHT THROUGH TUESDAY...THE ECM AND NAM ARE THE SLOWEST SOLNS
WITH THE PASSAGE OF THE PACIFIC FRONT MONDAY NIGHT AND TUESDAY. THUS
RAIN CHANCES ARE DELAYED UNTIL EARLY MONDAY MORNING. IT IS POSSIBLE
THE FASTER AND STRONGER GFS/GEM SOLNS ARE A BETTER FCST BUT GIVEN
THE MODELS HAVE BEEN TRENDING SLOWER OVERALL...THE NAM/ECM APPEARS TO
BE THE BEST FIT.
A SOLID PV ANOMALY WILL BE APPROACHING THE FCST AREA MONDAY AFTN AND
THIS SHOULD PROVIDE AMPLE SUPPORT FOR SCATTERED TO NUMEROUS TSTMS
INTO THE EVENING. COLD AIR ALOFT AND PWS OVER 200 PERCENT OF NORMAL
ARE EXPECTED TO PRODUCE HEAVY RAIN...MAINLY ALONG AND WEST OF
HIGHWAY 61. THE NAM/ECM SOLN PRODUCES 1 TO 1.5 INCHES OF RAIN IN THE
WEST DOWN TO 1/4 INCH IN THE EAST. POPS ARE LIMITED TO THE LIKELY
CATEGORY FOR THIS FORECAST AS MODEL TIMING IS THE MAIN CONCERN FOR
THE FORECAST.
SOUTHEAST WINDS MONDAY INCREASE TO 25 MPH WITH GUSTS TO 35 MPH. THE
GFS/GEM MODELS SUGGEST 30 MPH WINDS GUSTING TO 40 MPH. THE MAX
TEMPERATURE FORECAST COOLS INTO THE UPPER 70S TO LOWER 80S. AN
INCREASE IN MID LEVEL CLOUDINESS IS EXPECTED WITH THE APPROACH OF
THE UPPER LOW.
SPC SUGGESTED AMPLE SHEAR WILL DEVELOP MONDAY AFTN AS SOUTHERLY
H500MB WINDS INCREASE TO 60 KT. THIS IS TRUE BUT COUPLED WITH THE
STRONG LOWER LEVEL SOUTHERLY WINDS...20 TO 30 KT...THE EFFECTIVE
SHEAR APPEARS WEAK NEAR 20 TO 30 KT AND THE NAM SOUNDINGS SUGGEST
NARROW CAPE. THE SIGNIFICANT SEVERE PARAMETER IN ALL SOLNS SEEMS TO
SUPPORT THE 5 PERCENT SEVERE WEATHER POTENTIAL MONDAY.
THE PACIFIC FRONT MOVES THROUGH THE FCST AREA TUESDAY. THE H500MB
COLD POOL CENTERED OVER SD SHOULD CONTINUE TO SUPPORT CONVECTION
ACROSS NRN NEB WITH HIGHS IN THE 60S TO LOWER 70S. THE 500M AGL
WINDS IN THE GFS...ECM AND GEM INCREASE TO OVER 30 KT ACROSS NRN NEB
DURING THE AFTN WHICH WOULD SUPPORT A WIND ADVISORY. THE 12Z ECM HAS
TRENDED TOWARD THE DEEPER GFS/GEM LOW PRESSURE SYSTEM SOLN. THE
STRONG WINDS DEVELOP IN CONJUNCTION WITH THE PV ANOMALY AND H700MB
WINDS OF 45 TO 55 KT SHOWN IN THESE MODELS.
TUESDAY NIGHT THROUGH SATURDAY...STRONG COLD FRONTS MOVE THROUGH
WEDNESDAY NIGHT AND THURSDAY NIGHT. BOTH SUGGEST A CHANCE OF
SHOWERS. THE SECOND COLD FRONT SENDS H850MB TEMPERATURES TO NEAR 0C
FRIDAY MORNING. HIGHS FRIDAY RISE INTO JUST THE 50S TO LOWER 60S
WHICH WOULD SUPPORT FROST SATURDAY MORNING BUT THIS HIGH MOVES OFF
VERY QUICKLY AND WARM AIR RETURNS TO THE FCST AREA FRIDAY NIGHT.
OTHERWISE HIGHS RISE INTO THE 60S AND 70S EACH DAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 128 PM CDT SAT SEP 27 2014
VFR CONDITIONS WILL CONTINUE INTO TONIGHT...THEN WITH SOUTHERLY
FLOW THERE IS POTENTIAL FOR SOME FOG EARLY SUNDAY MORNING AS LOW
LEVEL MOISTURE INCREASES. AT THIS TIME CONFIDENCE ISN/T REAL HIGH
WITH THE FOG DEVELOPING AND WITH MODELS SHOWING THE AXIS OF
MOISTURE WEST OF HIGHWAY 83 CONFIDENCE IS LESS THAT ANY VISIBILITY
RESTRICTION WILL BE REALIZED AT EITHER KLBF OR KVTN. FOR THIS
FORECAST CYCLE ADDED IN A 4SM IN LIGHT FOG FOR KLBF...WHILE
KEEPING VFR CONDITIONS AT KVTN DUE TO UNCERTAINTY TO HOW FAR NORTH
THE MOISTURE WILL GET. WINDS TODAY WILL DIMINISH THIS EVENING TO
UNDER 10KTS THEN ARE EXPECTED TO PICK UP AGAIN SUNDAY AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BROOKS/CDC
SHORT TERM...BROOKS
LONG TERM...CDC
AVIATION...BROOKS
AREA FORECAST DISCUSSION...UPDATE
NWS PENDLETON OR
1031 AM PDT SAT SEP 27 2014
UPDATED FOR AVIATION DISCUSSION
.SHORT TERM...THROUGH MONDAY. NO CHANGES PLANNED IN FORECAST. WRAP
AROUND MOISTURE FROM SLOW MOVING UPPER LOW IN NEVADA WILL CONTINUE
TO AFFECT THE AREA EAST OF WALLA WALLA...PENDLETON...AND JOHN
DAY. TEMPERATURES WILL CONTINUE COOLER IN THESE AREAS UNDER MORE
EXTENSIVE CLOUD COVER. REST OF AREA WILL HAVE NEAR NORMAL
TEMPERATURES...LIGHT WINDS...AND FREQUENT PERIODS OF SUNSHINE.
&&
.AVIATION...18Z TAFS...VFR CONDITIONS WILL PREVAIL OVER THE NEXT 24
HOURS...WITH SCATTERED CLOUDS 08-15KFT AT THE SOUTHEAST TAF SITES
AND MOSTLY CLEAR SKIES FOR THE WESTERN TAF SITES. WINDS WILL BE
MAINLY OUT OF THE NORTH 5-15KTS...WITH GUSTS AROUND 15-20KTS.
WEBER
&&
.PREV DISC... /ISSUED 132 AM PDT SAT SEP 27 2014/
SHORT TERM...TODAY THROUGH MONDAY...UNSETTLED WEATHER WILL CONTINUE
TODAY AND MONDAY AS AN UPPER TROUGH MOVES ACROSS THE REGION. THE
OVERALL FLOW WILL BE SPLIT WITH A SUBTLE TROUGH OVER NORTHERN
WASHINGTON AND A CLOSED UPPER LOW OVER NORTHERN CALIFORNIA AND
SOUTHERN OREGON. THE MODELS ARE ADVERTISING WRAP AROUND MOISTURE ON
THE NORTH SIDE OF THE UPPER LOW TO MOVE INTO THE EAST AND SOUTHEAST
PORTION OF THE CWA TODAY THROUGH MONDAY. THE HRRR MODEL IS SHOWING
PRECIPITATION INCREASING FROM THE SOUTHEAST INTO THE EASTERN AND
NORTHEAST MOUNTAINS OF THE CWA TODAY. AS SUCH WILL KEEP A SLIGHT
CHANCE TO CHANCE POPS IN THE FORECAST FOR THE EASTERN AND SOUTHEAST
BORDER REGION OF THE CWA. THE ECMWF CONTINUES TO BE FURTHER TO THE
NORTH AND WEST WITH THE PRECIPITATION WHILE THE GFS SHOWS MUCH LESS.
IT WILL REMAIN DRY TODAY AND SUNDAY FOR THE REMAINDER OF THE CWA.
THEN ON MONDAY THE NEXT WEATHER SYSTEM BEGINS TO MOVE INTO THE
WASHINGTON CASCADES WITH SOME INCREASE IN PRECIPITATION THERE.
TEMPERATURES WILL REMAIN NEAR NORMAL THROUGH THE PERIOD AND WINDS
WILL BE FAIRLY LIGHT...WITH THE HIGHEST GUSTS OF 15-20 KTS IN THE
AFTERNOONS AND EARLY EVENING. 88
LONG TERM...MONDAY NIGHT THROUGH SATURDAY...A BROAD UPPER LEVEL
TROUGH WILL MOVE ACROSS THE REGION MONDAY NIGHT AND TUESDAY WITH A
SLIGHT CHANCE FOR MAINLY MOUNTAIN SHOWERS AND BREEZY WINDS. A COOL
PRIMARILY DRY NW FLOW WILL WILL FOLLOW FOR WEDNESDAY AND THURSDAY AS
AN UPPER LEVEL RIDGE AMPLIFIES OFFSHORE. AS THE RIDGE MOVES OVER THE
AREA FOR FRIDAY AND SATURDAY...WARMING TEMPERATURES ARE EXPECTED. IT
SHOULD REMAIN MOSTLY DRY. THE ECMWF DOES SHOW A DISTURBANCE PASSING
TO THE NORTH OF THE REGION WITH PRECIPITATION IN WASHINGTON. FOR NOW
HAVE KEPT THE FORECAST AREA DRY EXCEPT FOR SLGT CHC POPS WA CASCADE
CREST. TEMPERATURES WILL START OUT NEAR TO SLIGHTLY BELOW NORMAL BUT
END UP ABOVE NORMAL BY FRIDAY AND SATURDAY. IT WILL BE QUITE COLD IN
THE MOUNTAIN VALLEYS WITH WIDESPREAD FREEZING TEMPERATURES. 78
AVIATION...12Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH 12Z
SUNDAY. MID AND HIGH CLOUDS ARE EXPECTED AT THE EASTERN TAF SITES
WITH MOSTLY CLEAR SKIES AT THE WESTERN SITES AS AN UPPER LEVEL LOW
PRESSURE SYSTEM MOVES TO OUR SE. WINDS WILL INCREASE FROM THE NW-N
THIS AFTERNOON AT 10-20 KT AND DIMINISH THIS EVENING. 78
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 71 52 72 52 / 10 10 10 10
ALW 74 55 74 56 / 10 10 10 10
PSC 77 53 77 52 / 0 10 10 10
YKM 74 51 76 49 / 10 0 0 10
HRI 76 50 76 50 / 10 10 10 10
ELN 72 49 73 48 / 10 0 0 10
RDM 66 39 68 39 / 10 10 10 10
LGD 67 45 68 45 / 20 20 20 20
GCD 66 44 68 43 / 20 20 20 20
DLS 75 53 77 54 / 10 10 10 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
79/89/89
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
434 PM EDT SAT SEP 27 2014
.SYNOPSIS...
COOL HIGH PRESSURE WILL PERSIST ACROSS THE REGION TONIGHT AND WEAKEN
ON SUNDAY. A LOW PRESSURE SYSTEM WILL MOVE NORTHWARD FROM THE GULF
OF MEXICO SUNDAY NIGHT AND MONDAY AND SPREAD RAIN ACROSS THE REGION.
THE LOW SHOULD MOVE SLOWLY AWAY TO THE NORTHEAST MONDAY NIGHT AND
TUESDAY WITH COOL HIGH PRESSURE BUILDING IN FROM THE NORTHEAST ON
WEDNESDAY. A COLD FRONT WILL ARRIVE FROM THE NORTHWEST LATE IN THE
WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 430 PM EDT SATURDAY...MOSTLY SUNNY SKIES AND TEMPERATURES IN
THE LOWER/MID 70S CONTINUE TO PREVAIL AMONGST DRIER NORTHEASTERLY
FLOW. ON THE CONTRARY...WEDGE BOUNDARY DRAPED SOUTH OF INTERSTATE
85 IN PROXIMITY TO THE SAVANNAH RIVER VALLEY CONTINUES TO YIELD
PARTLY/MOSTLY CLOUDY SKIES. MADE SLIGHT TWEAKS TO THE SKY FORECAST
TO ACCOUNT FOR MOST RECENT SATELLITE AND OBSERVATIONAL TRENDS. ALSO
ADJUSTED TEMPERATURES AND DEWPOINTS IN THE EXTREME NEAR TERM TO
REFLECT LATEST OBS FROM AROUND THE REGION.
PREVIOUS DISCUSSION...
AS OF 220 PM...DRY AIR CONTINUES TO MIX IN FROM THE NE ALIGNED IN A
PERSISTENT SFC WEDGE. THE MAJORITY OF HIGHER MOISTURE AND CLOUD
COVER HAS PUSHED OUT OF THE CWFA WITH LINGER BKN/OVC CONDS ACROSS
THE SW/RN ZONES. TEMPS WILL CONTINUE TO RISE A FEW MORE DEGREES
THROUGH MAX HEATING...REMAINING A CAT OR SO BELOW NORMAL.
A QUIET OVERNIGHT PERIOD IS IN STORE WITH A SUBTROPICAL HIGH
REMAINING OVER THE SE CONUS. RAP SOUNDINGS ARE SHOWING A DECOUPLED
ATMOS OVERNIGHT...ALLOWING MINS TO REACH NORMAL LEVELS NORTH AND A
COUPLE DEGREES ABOVE NORMAL SOUTH WITH LINGERING CLOUDS. THERE COULD
BE SOME MTN VALLEY FG DEVELOPING ARND SUNRISE...BUT TDDS WILL REMAIN
FAIRLY HIGH FOR MUCH OF A DENSE THREAT.
LOW TO MID LEVEL ATL MOISTURE BEGINS PUSHING IN EARLY SUN MORNING
AND THE SRN ZONES WILL SEE THE BEST CLOUD COVER AFT DAYBREAK. THE
NAM IS MORE AGGRESSIVE WITH THIS SCENARIO THAN THE GFS...WHICH KEEPS
THE DEEPER MOISTURE ALIGNED ALONG THE WEDGE BNDRY. SRN FA SOUNDINGS
SHOW NEARLY SATURATED COLUMNS BY THE AFTERNOON AS A WEAK COASTAL LOW
BEGINS ADVECTING GOM MOISTURE INTO THE REGION. STILL...THE MAIN FLOW
WILL BE ATL...WHICH WILL INSTIGATE GOOD MECH LIFT ACROSS THE SRN
ESCARPMENT...NE GA AND SW NC MTNS BY THE AFTERNOON. POPS WILL RISE
QUICKLY INTO THE HIGH CHANCE AND LOW/END LIKELY RANGE SUN AFTERNOON
ACROSS THE FAR WEST...HOWEVER PRECIP AMOUNTS WILL REMAIN FAIRLY LOW
THROUGH THE NRT PERIOD AS INSTABILITY REMAINS LOW KEEPING CONVEC
PRECIP WELL SOUTH. POPS WILL REMAIN NIL OUTSIDE THE MTNS AND SW/RN
ZONES. MAX TEMPS WILL FEATURE A SW/NE COOL/WARM GRADIENT DUE TO
CLOUD COVER AND DIFF HEATING.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 245 PM SATURDAY...AN H5 SHORTWAVE WILL LIFT FROM THE GULF
COAST TO THE EXTREME SRN APPALACHIANS SUNDAY NIGHT AND MERGE WITH A
NRN STREAM SHORTWAVE SWINGING EAST THROUGH THE OH VALLEY. AT LOWER
LEVELS...AN INCREASINGLY MOIST SOUTHEAST UPSLOPE FLOW WILL SET UP
OVER THE FORECAST AREA SUNDAY NIGHT TO ALLOW PRECIPITATION TO BECOME
WIDESPREAD BY DAYBREAK MONDAY...ACROSS AT LEAST THE SW HALF OF THE
AREA. DEEP LAYER FORCING WILL THEN CROSS THE REGION MON WITH THE
MERGING UPPER WAVES AND PASSING UPPER LEVEL JET DIVERGENCE. AN 850
MB LOW CENTER WILL LIKELY RIDE NE THROUGH THE SOUTHEAST PART OF THE
FORECAST AREA...SETTING UP ADDITIONAL WEAK FRONTOGENESIS OVER THE
AREA. THESE FEATURES WILL BE VERY SLOW TO MOVE E OR NE TO THE COAST
MON NIGHT THROUGH TUE...WITH CONTINUED LIGHT PRECIPITATION WRAPPING
BACK OVER THE REGION ON THE W SIDE OF THE LOW.
THE MAIN LIMITING FACTORS FOR HEAVY QPF ARE A FAIRLY DRY BOUNDARY
LAYER IN THE NC PIEDMONT AT ONSET...AS WELL AS THE STRONG POTENTIAL
FOR GULF COASTAL CONVECTION AND CONVECTION NEAR A WEAK WEDGE
BOUNDARY IMPEDING THE INFLUX OF MOISTURE. SO..THE QUESTION IS NOT
WHETHER IT WILL RAIN...BUT HOW MUCH. THE 12Z GFS IS PRODUCING A
BULLSEYE OF NEARLY 6 INCHES ALONG THE INTERSTATE 85 CORRIDOR...BUT
IT FEATURES LITTLE TO NO GULF COASTAL CONVECTION. THIS SOLUTION
SEEMS UNLIKELY...AND THE FORECAST WILL CONTINUE TO LEAN HEAVILY ON A
MODEL BLEND WITH A HEAVY NOD TOWARD THE DRIER SREF MEAN AND LATEST
ECM QPF. IN ADDITION...WITH A WEAK SURFACE CAD LAYER PERSISTING OR
REDEVELOPING AS THE RAIN ARRIVES...INSTABILITY SHOULD BE LARGELY
SHUNTED SOUTH OF THE REGION FOR THE UPCOMING EVENT. WITH 850 TO 500
MB LAPSE RATES RATHER WEAK OVER THE SFC HIGH...RAINFALL RATES SHOULD
NOT BE HIGH ENOUGH TO SUPPORT FLASH FLOODING. DURATION RAINFALL
ALONG MAIN STEMS AND THE MOST FLOOD PRONE AREAS WILL NEED TO BE
MONITORED...BUT ANTECEDENT CONDITIONS ARE UNFAVORABLE FOR MUCH OF A
HYDRO THREAT GIVEN EXPECTED QPF/DURATION. STILL...AN HWO MENTION
SEEMS WARRANTED FOR AT LEAST THE HEAVY RAINFALL MONDAY. A SMALLER
THAN MOS DIURNAL RANGE ON TEMPS WILL BE FEATURED WITH CAD CONDITIONS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM EDT SAT...A WEAK UPPER RIDGING WILL BUILD IN FROM THE
WEST TUE NIGHT INTO WED AS A DEAMPLIFYING SHORTWAVE PUSHES OFF THE
ATLANTIC COAST. THE UPPER RIDGE AXIS SHOULD CROSS THE REGION
THU...WITH SWLY FLOW ALOFT SETTING UP BY FRI IN LIGHT OF A DEEP
UPPER TROUGH APPROACHING FROM THE CENTRAL CONUS. THIS TROUGH IS
EXPECTED TO MOVE ACROSS THE EASTERN STATES LATE SAT INTO SUN.
AT THE SURFACE...A SURFACE WEDGE WILL SET UP ACROSS THE REGION BY
TUE NIGHT AND PERSIST THROUGH THU...YIELDING CONSIDERABLE LLVL
CLOUDINESS AND COOL NE WINDS DURING THIS PERIOD. NE WINDS SHOULD
VEER TO THE SE BY THU NIGHT AS THE SURFACE RIDGE WEAKENS AND SHIFT
EAST WHILE AN ACTIVE COLD FRONT APPROACHES FROM THE MISSISSIPPI
VALLEY. BOTH THE NEW 12Z GFS/ECMWF AGREE THAT THE FRONT WILL REACH
THE SOUTHERN APPALACHIANS BY AROUND SAT 00Z AND OFF TO OUR EAST BY
AROUND 12Z SAT. THE THREAT FOR SEVERE WEATHER LOOKS MINIMAL GIVEN
THE LATE OF GOOD UPPER FORCING/BOUNCY. IN FACT...MODELS HAVE TRENDED
A BIT DRIER AS THE FRONT WEAKENS AS IT CROSS THE FORECAST AREA.
HENCE...HAVE INHERITED LOW END CHANCE POPS DURING THE FROPA.
CONDITIONS SHOULD DRY OUT BY SAT AFTERNOON AS THE FRONT PUSHES
OFFSHORE AND A COOL DRY HIGH PRESSURE BUILDS IN FROM THE NW.
TEMPERATURES WILL REMAIN 3-7 DEGREES BELOW NORMAL THROUGHOUT THE
MEDIUM RANGE PERIOD.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
AT KCLT...VFR CONDS EXPECTED THROUGH THE PERIOD. FEW TO SCT CU WILL
PERSIST THIS AFTERNOON...BUT REMAIN ABV 030. LOW TO MID LEVEL ATL
MOISTURE FLUX WILL COMMENCE OVERNIGHT WHICH WILL BRING IN
CLOUDS...BUT NOT ENOUGH FOR A RESTRICTIVE CIG MENTION. THESE CLOUDS
WILL ALSO OFFSET MUCH A VSBY CONCERN ARND DAYBREAK.
ELSEWHERE...VFR CONDS WILL PERSIST THROUGH MOST OF THE TAF PERIOD
WITH LINGER LOW VFR CU THROUGH THE AFTERNOON. ATL MOISTURE FLUX WILL
BRING IN MVFR CLOUDS FAIRLY LATE...ARND DAYBREAK WHICH SHOULD AFFECT
ALL TERMINALS THROUGHOUT THE MORNING...WITH CIGS LIFTING TO VFR
PROBABLE NEAR THE END OF THE TAF PERIOD.
OUTLOOK...HIGH LEVELS MOISTURE WILL RETURN FOR THE START OF THE WORK
WEEK ASSOCIATED WITH AN AREA OF UNSETTLE WEATHER MOVING NORTH OUT OF
THE GULF OF MEXICO. PERIODS OF CONTINUOUS MODERATE TO HEAVY RAINFALL
WILL AFFECT THE AREA MON/TUE PRODUCING LOW CIGS AND VSBY.
CONFIDENCE TABLE...
20-02Z 02-08Z 08-14Z 14-20Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 94% MED 69%
KAVL HIGH 100% HIGH 88% MED 67% MED 60%
KHKY HIGH 100% HIGH 100% HIGH 84% MED 75%
KGMU HIGH 100% HIGH 100% HIGH 94% MED 69%
KAND HIGH 100% HIGH 100% HIGH 93% MED 78%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...CDG/SBK
SHORT TERM...HG
LONG TERM...JOH
AVIATION...SBK
AREA FORECAST DISCUSSION...CORRECTED
NWS GREENVILLE-SPARTANBURG SC
259 PM EDT SAT SEP 27 2014
.SYNOPSIS...
COOL HIGH PRESSURE WILL PERSIST ACROSS THE REGION TONIGHT AND WEAKEN
ON SUNDAY. A LOW PRESSURE SYSTEM WILL MOVE NORTHWARD FROM THE GULF
OF MEXICO SUNDAY NIGHT AND MONDAY AND SPREAD RAIN ACROSS THE REGION.
THE LOW SHOULD MOVE SLOWLY AWAY TO THE NORTHEAST MONDAY NIGHT AND
TUESDAY WITH COOL HIGH PRESSURE BUILDING IN FROM THE NORTHEAST ON
WEDNESDAY. A COLD FRONT WILL ARRIVE FROM THE NORTHWEST LATE IN THE
WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 220 PM...DRY AIR CONTINUES TO MIX IN FROM THE NE ALIGNED IN A
PERSISTENT SFC WEDGE. THE MAJORITY OF HIGHER MOISTURE AND CLOUD
COVER HAS PUSHED OUT OF THE CWFA WITH LINGER BKN/OVC CONDS ACROSS
THE SW/RN ZONES. TEMPS WILL CONTINUE TO RISE A FEW MORE DEGREES
THROUGH MAX HEATING...REMAINING A CAT OR SO BELOW NORMAL.
A QUIET OVERNIGHT PERIOD IS IN STORE WITH A SUBTROPICAL HIGH
REMAINING OVER THE SE CONUS. RAP SOUNDINGS ARE SHOWING A DECOUPLED
ATMOS OVERNIGHT...ALLOWING MINS TO REACH NORMAL LEVELS NORTH AND A
COUPLE DEGREES ABOVE NORMAL SOUTH WITH LINGERING CLOUDS. THERE COULD
BE SOME MTN VALLEY FG DEVELOPING ARND SUNRISE...BUT TDDS WILL REMAIN
FAIRLY HIGH FOR MUCH OF A DENSE THREAT.
LOW TO MID LEVEL ATL MOISTURE BEGINS PUSHING IN EARLY SUN MORNING
AND THE SRN ZONES WILL SEE THE BEST CLOUD COVER AFT DAYBREAK. THE
NAM IS MORE AGGRESSIVE WITH THIS SCENARIO THAN THE GFS...WHICH KEEPS
THE DEEPER MOISTURE ALIGNED ALONG THE WEDGE BNDRY. SRN FA SOUNDINGS
SHOW NEARLY SATURATED COLUMNS BY THE AFTERNOON AS A WEAK COASTAL LOW
BEGINS ADVECTING GOM MOISTURE INTO THE REGION. STILL...THE MAIN FLOW
WILL BE ATL...WHICH WILL INSTIGATE GOOD MECH LIFT ACROSS THE SRN
ESCARPMENT...NE GA AND SW NC MTNS BY THE AFTERNOON. POPS WILL RISE
QUICKLY INTO THE HIGH CHANCE AND LOW/END LIKELY RANGE SUN AFTERNOON
ACROSS THE FAR WEST...HOWEVER PRECIP AMOUNTS WILL REMAIN FAIRLY LOW
THROUGH THE NRT PERIOD AS INSTABILITY REMAINS LOW KEEPING CONVEC
PRECIP WELL SOUTH. POPS WILL REMAIN NIL OUTSIDE THE MTNS AND SW/RN
ZONES. MAX TEMPS WILL FEATURE A SW/NE COOL/WARM GRADIENT DUE TO
CLOUD COVER AND DIFF HEATING.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 245 PM SATURDAY...AN H5 SHORTWAVE WILL LIFT FROM THE GULF
COAST TO THE EXTREME SRN APPALACHIANS SUNDAY NIGHT AND MERGE WITH A
NRN STREAM SHORTWAVE SWINGING EAST THROUGH THE OH VALLEY. AT LOWER
LEVELS...AN INCREASINGLY MOIST SOUTHEAST UPSLOPE FLOW WILL SET UP
OVER THE FORECAST AREA SUNDAY NIGHT TO ALLOW PRECIPITATION TO BECOME
WIDESPREAD BY DAYBREAK MONDAY...ACROSS AT LEAST THE SW HALF OF THE
AREA. DEEP LAYER FORCING WILL THEN CROSS THE REGION MON WITH THE
MERGING UPPER WAVES AND PASSING UPPER LEVEL JET DIVERGENCE. AN 850
MB LOW CENTER WILL LIKELY RIDE NE THROUGH THE SOUTHEAST PART OF THE
FORECAST AREA...SETTING UP ADDITIONAL WEAK FRONTOGENESIS OVER THE
AREA. THESE FEATURES WILL BE VERY SLOW TO MOVE E OR NE TO THE COAST
MON NIGHT THROUGH TUE...WITH CONTINUED LIGHT PRECIPITATION WRAPPING
BACK OVER THE REGION ON THE W SIDE OF THE LOW.
THE MAIN LIMITING FACTORS FOR HEAVY QPF ARE A FAIRLY DRY BOUNDARY
LAYER IN THE NC PIEDMONT AT ONSET...AS WELL AS THE STRONG POTENTIAL
FOR GULF COASTAL CONVECTION AND CONVECTION NEAR A WEAK WEDGE
BOUNDARY IMPEDING THE INFLUX OF MOISTURE. SO..THE QUESTION IS NOT
WHETHER IT WILL RAIN...BUT HOW MUCH. THE 12Z GFS IS PRODUCING A
BULLSEYE OF NEARLY 6 INCHES ALONG THE INTERSTATE 85 CORRIDOR...BUT
IT FEATURES LITTLE TO NO GULF COASTAL CONVECTION. THIS SOLUTION
SEEMS UNLIKELY...AND THE FORECAST WILL CONTINUE TO LEAN HEAVILY ON A
MODEL BLEND WITH A HEAVY NOD TOWARD THE DRIER SREF MEAN AND LATEST
ECM QPF. IN ADDITION...WITH A WEAK SURFACE CAD LAYER PERSISTING OR
REDEVELOPING AS THE RAIN ARRIVES...INSTABILITY SHOULD BE LARGELY
SHUNTED SOUTH OF THE REGION FOR THE UPCOMING EVENT. WITH 850 TO 500
MB LAPSE RATES RATHER WEAK OVER THE SFC HIGH...RAINFALL RATES SHOULD
NOT BE HIGH ENOUGH TO SUPPORT FLASH FLOODING. DURATION RAINFALL
ALONG MAIN STEMS AND THE MOST FLOOD PRONE AREAS WILL NEED TO BE
MONITORED...BUT ANTECEDENT CONDITIONS ARE UNFAVORABLE FOR MUCH OF A
HYDRO THREAT GIVEN EXPECTED QPF/DURATION. STILL...AN HWO MENTION
SEEMS WARRANTED FOR AT LEAST THE HEAVY RAINFALL MONDAY. A SMALLER
THAN MOS DIURNAL RANGE ON TEMPS WILL BE FEATURED WITH CAD CONDITIONS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM EDT SAT...A WEAK UPPER RIDGING WILL BUILD IN FROM THE
WEST TUE NIGHT INTO WED AS A DEAMPLIFYING SHORTWAVE PUSHES OFF THE
ATLANTIC COAST. THE UPPER RIDGE AXIS SHOULD CROSS THE REGION
THU...WITH SWLY FLOW ALOFT SETTING UP BY FRI IN LIGHT OF A DEEP
UPPER TROUGH APPROACHING FROM THE CENTRAL CONUS. THIS TROUGH IS
EXPECTED TO MOVE ACROSS THE EASTERN STATES LATE SAT INTO SUN.
AT THE SURFACE...A SURFACE WEDGE WILL SET UP ACROSS THE REGION BY
TUE NIGHT AND PERSIST THROUGH THU...YIELDING CONSIDERABLE LLVL
CLOUDINESS AND COOL NE WINDS DURING THIS PERIOD. NE WINDS SHOULD
VEER TO THE SE BY THU NIGHT AS THE SURFACE RIDGE WEAKENS AND SHIFT
EAST WHILE AN ACTIVE COLD FRONT APPROACHES FROM THE MISSISSIPPI
VALLEY. BOTH THE NEW 12Z GFS/ECMWF AGREE THAT THE FRONT WILL REACH
THE SOUTHERN APPALACHIANS BY AROUND SAT 00Z AND OFF TO OUR EAST BY
AROUND 12Z SAT. THE THREAT FOR SEVERE WEATHER LOOKS MINIMAL GIVEN
THE LATE OF GOOD UPPER FORCING/BOUNCY. IN FACT...MODELS HAVE TRENDED
A BIT DRIER AS THE FRONT WEAKENS AS IT CROSS THE FORECAST AREA.
HENCE...HAVE INHERITED LOW END CHANCE POPS DURING THE FROPA.
CONDITIONS SHOULD DRY OUT BY SAT AFTERNOON AS THE FRONT PUSHES
OFFSHORE AND A COOL DRY HIGH PRESSURE BUILDS IN FROM THE NW.
TEMPERATURES WILL REMAIN 3-7 DEGREES BELOW NORMAL THROUGHOUT THE
MEDIUM RANGE PERIOD.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
AT KCLT...VFR CONDS EXPECTED THROUGH THE PERIOD. FEW TO SCT CU WILL
PERSIST THIS AFTERNOON...BUT REMAIN ABV 030. LOW TO MID LEVEL ATL
MOISTURE FLUX WILL COMMENCE OVERNIGHT WHICH WILL BRING IN
CLOUDS...BUT NOT ENOUGH FOR A RESTRICTIVE CIG MENTION. THESE CLOUDS
WILL ALSO OFFSET MUCH A VSBY CONCERN ARND DAYBREAK.
ELSEWHERE...VFR CONDS WILL PERSIST THROUGH MOST OF THE TAF PERIOD
WITH LINGER LOW VFR CU THROUGH THE AFTERNOON. ATL MOISTURE FLUX WILL
BRING IN MVFR CLOUDS FAIRLY LATE...ARND DAYBREAK WHICH SHOULD AFFECT
ALL TERMINALS THROUGHOUT THE MORNING...WITH CIGS LIFTING TO VFR
PROBABLE NEAR THE END OF THE TAF PERIOD.
OUTLOOK...HIGH LEVELS MOISTURE WILL RETURN FOR THE START OF THE WORK
WEEK ASSOCIATED WITH AN AREA OF UNSETTLE WEATHER MOVING NORTH OUT OF
THE GULF OF MEXICO. PERIODS OF CONTINUOUS MODERATE TO HEAVY RAINFALL
WILL AFFECT THE AREA MON/TUE PRODUCING LOW CIGS AND VSBY.
CONFIDENCE TABLE...
19-01Z 01-07Z 07-13Z 13-19Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% MED 65%
KAVL HIGH 100% HIGH 100% LOW 59% LOW 54%
KHKY HIGH 100% HIGH 100% HIGH 97% MED 61%
KGMU HIGH 100% HIGH 100% HIGH 100% MED 65%
KAND HIGH 100% HIGH 100% HIGH 98% MED 72%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...SBK
SHORT TERM...HG
LONG TERM...JOH
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1240 PM CDT SAT SEP 27 2014
.UPDATE...FOR 18Z AVIATION
&&
.AVIATION...
A WEAK SFC TROUGH ACROSS MIDDLE TN WILL KEEP THE CLOUDS AROUND
TODAY BUT ALL SHOULD BE VFR FOR THE MOST PART. MAYBE A FEW BKN
MVFR CIGS IN AND OUT OF CSV THROUGH THE AFTERNOON. ANY ISOLATED
SHRA THAT POP UP THIS AFTERNOON WILL NOT AFFECT VSBYS/CIGS AT
TERMINALS.
OVERNIGHT MOISTURE WILL CONTINUE TO PUSH INTO THE REGION AND WITH
LIGHT WINDS IN STORE...SOME MVFR BR MAY BE POSSIBLE AROUND DAWN.
HINTED AT THAT IN ALL TAF SITES. SHOWERS WILL BE POSSIBLE FROM
LATE MORNING ON BUT MAY NOT AFFECT TAF SITES. BEST CHC LOOKS TO BE
ALONG WEAK SFC TROUGH AND THUS CKV/BNA. INSERTED VCSH TOWARD THE
END OF THIS TAF PERIOD FOR BOTH SITES.
&&
.PREV DISCUSSION... /ISSUED 1002 AM CDT SAT SEP 27 2014/
MORNING UPDATE...
REMOVED MORNING FOG WORDING FROM THE GRIDS/ZONES. MOST OF THE
FORECAST SEEMS TO BE ON TRACK THEREAFTER. HOWEVER...THE HRRR AND
OTHER WRF MODELS SHOW SOME AFTERNOON SHOWERS DEVELOPING ACROSS
SOUTHERN MIDDLE TN. RIGHT NOW LAPS SOUNDINGS HAVE US CAPPED AROUND
600MB BUT COULD SEE SOME SHALLOW SHOWERS DEVELOP GIVEN THE STEEP
LAPSE RATES BELOW THAT. THUS INSERTED A SLIGHT CHC OF SHOWERS OVER
THE FAR SOUTH THIS AFTERNOON. ONLY MINOR CHANGES MADE ELSEWHERE.
UPDATE ALREADY SENT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AL