Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/24/13
AREA FORECAST DISCUSSION
NWS TUCSON AZ
213 AM MST SUN SEP 22 2013
.SYNOPSIS...AN UPPER LEVEL TROUGH ALONG THE WEST COAST COUPLED WITH
A BIT OF MOISTURE OVER THE AREA WILL BE ENOUGH TO GENERATE A FEW
SHOWERS AND THUNDERSTORMS ACROSS SOUTHEAST ARIZONA TODAY. GUSTY
WINDS ALSO DEVELOPING AHEAD OF THIS SYSTEM TODAY. THE WESTERLY FLOW
BEHIND THIS TROUGH WILL START TO PUSH DRIER AIR ACROSS THE AREA LATE
TODAY AND KNOCK TEMPERATURES BACK TO NEAR OR BELOW AVERAGE FOR THE
NEW WEEK.
&&
.DISCUSSION...WATER VAPOR IMAGERY SHOWS A TROUGH MAKING ITS WAY
THROUGH SOUTHERN CALIFORNIA...WITH A RIDGE CENTERED WELL TO THE
SOUTH OVER THE SOUTHERN GULF OF CALIFORNIA WITH THE RIDGE AXIS
EXTENDING NORTHEAST ACROSS WEST TEXAS AND WESTERN OKLAHOMA. IR
SATELLITE IMAGERY SHOWS MID LEVEL CLOUDS OVER MAINLY THE CENTRAL AND
EASTERN PORTIONS OF THE FORECAST AREA. THE MODELS...INCLUDING THE U
OF A WRF NAM...WRF GFS AND HRRR INDICATE THAT ISOLATED TO SCATTERED
SHOWERS AND/OR THUNDERSTORMS WILL DEVELOP OVER CENTRAL LOCATIONS
INITIALLY...THEN DEVELOP OVER AREAS MAINLY TO THE NORTHEAST AND EAST
OF THE TUCSON AREA...WITH THE BEST POTENTIAL OVER THE WHITE
MOUNTAINS OF NORTHERN GREENLEE COUNTY. THIS SYSTEM IS EXPECTED TO
SWEEP THROUGH THE REGION QUICKLY WITH THE TROUGH MOVING INTO
NORTHWEST ARIZONA THIS MORNING AND THEN OVER THE FOUR CORNERS AREA
BY LATE THIS AFTERNOON AND OVER SOUTHERN COLORADO AND NORTHERN NEW
MEXICO LATE THIS EVENING.
ON MONDAY DRY NORTHWEST FLOW ALOFT WILL BRING COOLER HIGH TEMPS TO
THE REGION WITH HIGH PRESSURE BUILDING IN BEHIND THE TROUGH DURING
THE DAY ON TUESDAY...AND WILL MOVE INTO THE SOUTHERN PLAINS BY LATE
TUESDAY/EARLY WEDNESDAY AS THE TAIL END OF ANOTHER MUCH STRONGER
PACIFIC TROUGH SWEEPS THROUGH THE NORTHERN PART OF THE STATE DURING
THE LATTER PART OF THE WEEK AND INTO THE EARLY PART OF THE
WEEKEND.
BREEZY CONDITIONS WILL DEVELOP TODAY AHEAD OF THE TROUGH. WINDS WILL
INCREASE AGAIN INTO THE BREEZY CATEGORY WEDNESDAY AND THURSDAY AHEAD
OF THE NEXT TROUGH.
THE BOTTOM LINE IS A DRY FORECAST THROUGH THE REMAINDER OF THE
FORECAST PERIOD...AFTER THE THREAT FOR SHOWERS ENDS LATE TODAY.
HIGH AND LOW TEMPERATURES GENERALLY HOVERING WITHIN A FEW DEGREES
EITHER SIDE OF NORMAL THROUGH THE ENTIRE FORECAST PERIOD. MOLLERE
&&
.AVIATION...VALID THROUGH 23/12Z. FEW070 SCT-BKN100 WITH ISOLD
SHRA/TSRA...22/19Z SCT-BKN070 BKN100 SCT TSRA...AFT 23/03Z CONDS
BECMG SKC. S-SE WIND 5 TO 12 KT BECMG SW 10 TO 18 KTS WITH GUSTS TO
30 KT AFT 22/17Z. WIND EASING TO W-SW 6 TO 10 KT AFT 23/03Z.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. CERNIGLIA
&&
.FIRE WEATHER...A SIGNIFICANT UPPER LEVEL TROUGH WILL CROSS THE
STATE TODAY GENERATING SCATTERED THUNDERSTORMS...MAINLY THE TUCSON
REGION AND EAST. SOME OF THE STORMS COULD BE STRONG. THIS SYSTEM
WILL ALSO KICK UP A DECENT SW WIND LATE THIS MORNING...CONTINUING
THROUGH THE AFTERNOON. THEN MUCH DRIER AIR WILL INVADE THE REGION
TONIGHT RESULTING IN DRY WEATHER AND MUCH LOWER HUMIDITY LEVELS
MONDAY THROUGH THE COMING WEEK WITH TEMPERATURES DROPPING TO AROUND
SEASONAL NORMS. ANOTHER PASSING UPPER LEVEL SYSTEM WILL KICK UP
SOUTHWEST BREEZES WEDNESDAY AND THURSDAY AFTERNOONS BUT IT IS
EXPECTED TO PASS BY DRY. CERNIGLIA
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1226 PM MDT SUN SEP 22 2013
.UPDATE...
&&
.SHORT TERM...WEAK SHOWER BAND DEVELOPING OVER THE FRONT RANGE AT
THIS TIME. LITTLE CAPE TO WORK WITH BUT MOISTENING AND COOLING
ALOFT ARE SETTING IN. LOW LEVEL WIND SHIFT AND ASSOCIATED DRYING
HAS PUSHED EAST OF AKRON...STILL COULD HAVE SOME STRONGER STORMS
DEVELOP OVER SEDGWICK AND PHILLIPS COUNTIES THIS AFTERNOON...THERE
MAY BE A LITTLE CONVERGENCE CENTER NEAR HOLYOKE AHEAD OF THE
BETTER MOISTURE COMING UP FROM THE SOUTH. A SMALL RISK OF SEVERE
HAIL OR WIND WITH ANYTHING THAT WOULD FORM OUT THERE...IT WOULD
MOVE PRETTY QUICKLY EASTWARD. MORE SIGNIFICANT WEATHER IS THE
DEVELOPING THUNDERSTORM BAND CURRENTLY NEAR RIFLE...THIS SHOULD
DEVELOP AN ORGANIZED WIND FIELD AND IT IS ALREADY PRODUCING 40-50
MPH WIND GUSTS. THIS WILL MOVE OVER THE MOUNTAINS THIS AFTERNOON
REACHING DENVER IN THE 5 TO 7 PM TIME FRAME. SOME POTENTIAL FOR
SEVERE WIND GUSTS WITH THIS...WILL BE WATCHING THAT. NOT A LOT OF
CAPE BUT ORGANIZED LIFT COULD PRODUCE STRONG UPDRAFTS ON THIS
BOUNDARY...SMALLER THREAT OF HAIL. AS FAR AS THE RAIN
THREAT...GOOD UPDRAFTS COULD PROVIDE A BAND OF HEAVY RAIN...BUT
PROBABLY LASTING LESS THAN AN HOUR...MORE LIKELY A HALF INCH IN 30
MINUTES...SO THE FLASH FLOOD THREAT LOOKS LOW. MORE BANDS OF
THUNDERSTORMS BEHIND THAT THIS EVENING...TRANSITIONING INTO MORE
OF A STEADY LIGHTER RAIN ON THE PLAINS OVERNIGHT AS THE SYSTEM
DEVELOPS. AT THIS TIME NOT EXPECTING ENOUGH RAIN TO HAVE MUCH
IMPACT ON RIVERS...THOUGH SOME RISES ON SMALL CREEKS CAN BE
EXPECTED AS THE RUNOFF WILL BE PRETTY EFFICIENT.
&&
.AVIATION...EXPECT SOUTH WINDS TO DOMINATE THIS AFTERNOON. THERE
MAY BE A BIT OF AN EASTERLY COMPONENT IN THE EARLY AFTERNOON...BUT
MIXING AND OUTFLOW FROM MOUNTAIN CONVECTION SHOULD PRODUCE SW
WINDS LATER.
AN ORGANIZED N-S BAND OF THUNDERSTORMS WILL MOVE ACROSS THE
MOUNTAINS THIS AFTERNOON AND PASS THROUGH DENVER AROUND 00Z WITH
A PERIOD OF WEST WINDS. STRONG WEST WIND GUSTS IN THE 30-50 KNOT
RANGE MAY ACCOMPANY THIS AND COULD IMPACT LANDINGS AT KDEN...BUT
FOR AN HOUR OR LESS. THIS LINE WILL CONTINUE TO MOVE EAST AND BE
FOLLOWED BY WEAKER SHOWER BANDS OVERNIGHT. WINDS WILL
PREDOMINANTLY BE FROM THE WEST AT LESS THAN 20 KNOTS OVERNIGHT
THOUGH THERE COULD BE A FEW GUSTY PERIODS WITH SHOWERS. INSTRUMENT
APPROACHES TO KDEN MAY BE NEEDED DUE TO CEILINGS. THE SHOWERS WILL
MOVE EAST BY MONDAY MORNING...WINDS WILL BECOME NORTHWEST AND
INCREASE DURING THE DAY WITH GUSTS IN THE 20-30 KNOT RANGE
EXPECTED AT KDEN DURING THE AFTERNOON...A BIT LESS AT KAPA/KBJC.
&&
.PREV DISCUSSION... /ISSUED 340 AM MDT SUN SEP 22 2013/
SHORT TERM...A RATHER POTENT SHORTWAVE TROUGH CURRENTLY OVER THE
WESTERN GREAT BASIN ALONG WITH A MID-LEVEL CIRCULATION CENTER
EVIDENT ON H20 VAPOR SAT IMAGERY SOUTHEAST OF RENO NV ARE PROGGED
TO MOVE EAST-SOUTHEAST FAIRLY QUICKLY THIS MORNING. DETERMINISTIC
MODELS AND ENSEMBLE MEMBERS ARE IN REASONABLY GOOD AGREEMENT AS
THEY SHOW THIS SYSTEM INTENSIFYING/DEEPENING SOME AS IT
APPROACHES WESTERN COLORADO. MODEL CONSENSUS HAS THE 500MB LOW
NEARING THE 4-CORNERS AREA BY 00Z/TODAY. FROM THERE MODELS SHOW
THE LOW TRACKING NORTHEASTWARD ACROSS CENTRAL AND NORTHEAST
COLORADO OVERNIGHT. A VIGOROUS PACIFIC COLD FRONT TRAILING
SOUTHWESTWARD ACROSS NEVADA FROM A SFC LOW IN SOUTHEAST IDAHO IS
ALSO FCST TO TRACK EAST WITH THE UPPER TROUGH. MODELS SHOW THIS
SHARP BAROCLINIC ZONE MOVING INTO WESTERN COLORADO NOT TOO LONG
AFTER 18Z/TODAY...AND THEN MOVING OUT ONTO THE NERN PLAINS OF
COLORADO EARLY THIS EVENING. MODELS/ENSEMBLE MEMBERS SHOW A SFC
LOW FORMING ON THE FRONT SOMEWHERE BETWEEN DENVER AND GREELEY.
STEEP MID-LEVEL LAPSE RATES AND RATHER ROBUST DEEP LAYER QG
ASCENT WITH THE UPPER LOW PASS OVER THE NORTH CENTRAL CO MTNS
THIS AFTERNOON RESULTING IN SCATTERED TO NUMEROUS SHOWERS AND
ISOLATED TO SCATTERED T-STORMS. WETBULB ZERO EXPECTED TO REMAIN
ABOVE MTN TOP LEVEL DURING THE DAYLIGHT HOURS...BUT STG
EVAPORATIVE COOLING WITH CONVECTION COULD GENERATE A BRIEF BUT
INTENSE SNOW SHOWER ABOVE TIMBERLINE. IT NOW APPEARS AS THOUGH THE
PLAINS WILL SEE ITS BEST SHOT AT PRECIP THIS EVENING...OR PERHAPS
AS EARLY AS LATE THIS AFTERNOON. THE HRRR SHOWS WEAK TO MODERATE
REFLECTIVITIES OVER THE I-25 URBAN CORRIDOR AS EARLY AS 21Z/TODAY...
WHILE AT THE SAME TIME THE WRF AND NAM ONLY INDICATE WIDELY
SCATTERED WEAK ECHOS OVER THE FOOTHILLS AND PALMER DIVIDE.
HOWEVER ALL 3 MODELS INDICATE SEVERAL AREAS OF LIGHT TO MODERATE
REFLECTIVITY/QPF OVER THE FRONT RANGE AND OUT ACROSS THE NERN
PLAINS THIS EVENING. COULD SEE A FEW STRONG T-STORMS POP ON THE
PLAINS AROUND 00Z/MON JUST AHEAD OF THE COLD FRONT. NAM AND RAP
INDICATE AN ELONGATED AREA OF 750-1000 J/KG CAPE EXTENDING FROM
ELBERT COUNTY TO LOGAN COUNTY AROUND 00Z.
NAM AND GFS INDICATE THE GREATEST REFLECTIVITIES/QPF IN THE
N-CENTRAL MTNS AROUND SUMMIT COUNTY FROM 00Z-06Z THIS EVENING
WITH CAA FOLLOWING THE PASSAGE OF THE 700-500 TROUGH AXIS. QPF
TOTALS UP ALONG THE CONTINENTAL DIVIDE ON THE ORDER OF 0.35 TO
0.60 INCH BY MORNING. MODEL SNOW TOTALS RANGE FROM 1-4 INCHES IN
AREAS ROUGHLY ABOVE 9500 FEET. ELSEWHERE...SHOULD SEE AN END TO
THE SHOWERY PRECIP OVER AND NEAR THE EAST FACE OF THE FRONT RANGE
BY AROUND MIDNIGHT WITH THE DRYING EFFECTS OF DOWNSLOPE FLOW.
HOWEVER...FARTHER OUT ON THE PLAINS A TIGHT BAROCLINIC ZONE AND
LINGERING QG ASCENT ON THE BACKSIDE OF THE UPPER LOW WILL PROBABLY
KEEP LIGHT TO MODERATE PRECIP GOING THROUGHOUT THE NIGHT. RAIN
AMOUNTS IN THIS AREA BY MORNING GENERALLY UNDER A HALF INCH...WITH
LESSER AMOUNTS CLOSER IN TO THE FOOTHILLS. FLOODING IS NOT A
CONCERN AT THIS TIME.
TEMPERATURES TODAY ARE EXPECTED TO BE SLIGHTLY COOLER THAN YESTERDAY
BUT STILL SLIGHTLY ABOVE AVERAGE FOR THE DATE. HIGHS ON THE PLAINS
WILL RANGE FROM THE MID-70S NEAR THE FOOTHILLS TO THE MID-80S NEAR
THE NORTHEAST CORNER OF THE STATE. HIGH COUNTRY MAX TEMPS WILL RANGE
FROM THE MID-60S IN THE VALLEYS AND FOOTHILLS...TO AROUND 50 DEGS
ABOVE TIMBERLINE. TONIGHTS LOWS WILL RANGE FROM THE MID 40S/LOWER
50S ON THE PLAINS TO THE 20S/30S IN THE HIGH COUNTRY. GUSTY NWLY
WINDS OVER THE NRN FRONT RANGE OVERNIGHT MAY MAKE IT FEEL EVEN
COLDER THAN THAT.
LONG TERM...RATHER POTENT UPPER LEVEL TROUGH WILL MOVE QUICKLY ACROSS
THE AREA MON MORNING. LOOKS LIKE THIS SYSTEM MAY CLOSE OFF OVER
ERN CO AND THEN MOVE INTO SWRN NE BY MIDDAY. WILL HAVE SOME
FAVORABLE MID LVL QG ASCENT MON MORNING OVER NERN CO WHICH SHOULD
LEAD TO A GOOD CHC OF SHOWERS OVER THE PLAINS. ALONG THE FRONT
RANGE THE LOW LVL FLOW WILL BE STG NWLY WHICH WILL LIMIT PCPN
CHANCES. IN THE MTNS WILL SEE SOME LINGERING SNOW SHOWERS IN THE
MORNING BUT ACTIVITY SHOULD END BY MIDDAY AS DRIER AIR SPREADS
ACROSS. AS THE UPPER LEVEL LOW INTENSIFIES OVER SWRN NE AND DECENT
SFC GRADIENT OCCURS WILL SEE GUSTY NWLY WINDS IN THE NRN FOOTHILLS
AND ACROSS THE PLAINS. FOR NOW WILL KEEP SPEEDS BLO HIGH WIND
CRITERIA. AS FOR HIGHS WILL KEEP READINGS IN THE UPPER 60S TO
LOWER 70S OVER NERN CO.
BY MON EVENING THE UPPER LEVEL SYSTEM WILL MOVE QUICKLY EASTWARD
WITH DIMINISHING WINDS AND PCPN ENDING OVER THE FAR NERN PLAINS.
FOR TUE AND WED THE FLOW ALOFT WILL BECOME MORE SWLY AS ANOTHER
UPPER LEVEL TROUGH DEVELOPS OVER THE WRN US. THIS WILL LEAD TO A
DRY WX PTRN WITH WARMER TEMPS. HIGHS BY WED WILL BE IN THE LOWER TO
MID 80S OVER NERN CO.
BY THU ONE PIECE OF THE UPPER LEVEL TROUGH OVER THE WRN US WILL
MOVE ACROSS THE NRN ROCKIES WHILE A SECOND PIECE OF ENERGY MOVES
INTO THE GREAT BASIN. THIS WILL LEAVE NRN CO IN SWLY FLOW ALOFT.
SOME MOISTURE WILL INCREASE IN THE MTNS HOWEVER IT APPEARS BEST
CHC OF PCPN THU AFTN WILL STAY MAINLY OVER WRN CO THRU THU NIGHT.
HIGHS ON THU WILL REMAIN ABV NORMAL OVER NERN CO.
FOR FRI THE UPPER LEVEL TROUGH OVER THE GREAT BASIN WILL BEGIN TO
MOVE EAST AS A COLD FRONT MOVES INTO NERN CO. SHOULD SEE A GOOD
CHANCE OF RAIN AND SNOW IN THE MTNS WITH A CHC OF RAIN OVER NERN CO.
HIGHS ON FRI WILL TURN COOLER WITH READINGS IN THE 60S OVER THE
PLAINS. THE UPPER LEVEL TROUGH WILL MOVE EAST OF THE AREA BY SAT
WITH DRIER WEATHER AND SEASONAL TEMPERATURES.
AVIATION...SCATTERED HIGH CLOUDS EARLY THIS MORNING OVER THE
DENVER METRO AREA WILL GRADUALLY LOWER AS CLOUDS INCREASE IN
ADVANCE OF A PACIFIC COLD FRONT AND UPPER LEVEL LOW PRESSSURE
TROUGH TO OUR WEST. SOUTH-SOUTHWEST SFC WINDS OF 6-13KTS THIS
MORNING WILL GRADUALLY TURN EAST-SOUTHEASTERLY LATE MORNING/EARLY
AFTERNOON AS THE SURFACE TROUGH ALONG THE FOOTHILLS DEEPENS AHEAD
OF THE COLD FRONT. WESTERN PORTIONS OF THE DENVER METRO AREA
INCLUDING APA COULD SEE ISOLATED TO SCATTERED RAIN SHOWERS/
T-STORMS FORMING AFTER 21Z TODAY WITH THE ATMOSPHERE BECOMING
INCREASINGLY UNSTABLE. HOWEVER IT APPEARS THAT DENVER AREA
TERMINALS WILL SEE THEIR BEST CHANCE FOR SHOWERS/T-SHOWERS THIS
EVENING FROM 00Z-06Z JUST PRIOR TO AND SHORTLY AFTER PASSAGE OF
THE PACIFIC COLD FRONT. THE STRONGEST STORMS WILL LIKELY FORM
EAST OF THE METRO AREA WHERE THE LOWER ATMOSPHERE WILL BE MORE
MOIST AND UNSTABLE. CLOUD CEILINGS COULD BRIEFLY LOWER TO AROUND
5000 FT AGL WITH MODERATE RAINFALL THIS EVENING. EXPECT WINDS
AROUND SHOWERS/T-SHOWERS TO ALSO BE QUITE GUSTY AND VARIABLE IN
DIRECTION. CEILINGS SHOULD BEGIN RISING WITH SHOWERS ENDING AFTER
MIDNIGHT AS DRIER AIR MOVES IN BEHIND THE COLD FRONT.
HOWEVER...DIA COULD POSSIBLY SEE CIGS LOWERING AGAIN TO AROUND
3000 FT AGL WITH STRATUS TOWARDS MORNING. THE STRATUS WILL BE A
PRODUCT OF MOIST OUTFLOW FROM SHOWERS FARTHER OUT ON THE PLAINS.
HYDROLOGY...SCATTERED TO LIKELY SHOWERS AND ISOLATED TO SCATTERED
THUNDERSTORMS IN THE HIGH COUNTRY THIS AFTERNOON COULD PRODUCE
RAINFALL AMOUNTS RANGING FROM A QUARTER TO ONE-HALF INCH. SIMILAR
RAIN AMOUNTS ARE POSSIBLE ON THE PLAINS AND OVER THE FOOTHILLS
LATE THIS AFTERNOON AND EVENING. SHOWERS AND STORMS WILL MOVE
FAIRLY QUICKLY TODAY AND SO THE RISK OF HEAVY RAINFALL LEADING TO
FLASH FLOODING IS LOW. IN THE HIGH COUNTRY...ELEVATIONS ABOVE
AROUND 9500 FEET COULD SEE 2-4 INCHES OF SNOW ACCUMULATE BY
MORNING. AREAS ABOVE TIMBERLINE AS WELL AS WEST AND NORTHWEST
FACING SLOPES ARE IN THE BEST POSITION TO SEE THIS ACCUMULATION.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....RPK
AVIATION/UPDATE...GIMMESTAD
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
340 AM MDT SUN SEP 22 2013
.SHORT TERM...A RATHER POTENT SHORTWAVE TROUGH CURRENTLY OVER THE
WESTERN GREAT BASIN ALONG WITH A MID-LEVEL CIRCULATION CENTER
EVIDENT ON H20 VAPOR SAT IMAGERY SOUTHEAST OF RENO NV ARE PROGGED
TO MOVE EAST-SOUTHEAST FAIRLY QUICKLY THIS MORNING. DETERMINISTIC
MODELS AND ENSEMBLE MEMBERS ARE IN REASONABLY GOOD AGREEMENT AS
THEY SHOW THIS SYSTEM INTENSIFYING/DEEPENING SOME AS IT
APPROACHES WESTERN COLORADO. MODEL CONSENSUS HAS THE 500MB LOW
NEARING THE 4-CORNERS AREA BY 00Z/TODAY. FROM THERE MODELS SHOW
THE LOW TRACKING NORTHEASTWARD ACROSS CENTRAL AND NORTHEAST
COLORADO OVERNIGHT. A VIGOROUS PACIFIC COLD FRONT TRAILING
SOUTHWESTWARD ACROSS NEVADA FROM A SFC LOW IN SOUTHEAST IDAHO IS
ALSO FCST TO TRACK EAST WITH THE UPPER TROUGH. MODELS SHOW THIS
SHARP BAROCLINIC ZONE MOVING INTO WESTERN COLORADO NOT TOO LONG
AFTER 18Z/TODAY...AND THEN MOVING OUT ONTO THE NERN PLAINS OF
COLORADO EARLY THIS EVENING. MODELS/ENSEMBLE MEMBERS SHOW A SFC
LOW FORMING ON THE FRONT SOMEWHERE BETWEEN DENVER AND GREELEY.
STEEP MID-LEVEL LAPSE RATES AND RATHER ROBUST DEEP LAYER QG
ASCENT WITH THE UPPER LOW PASS OVER THE NORTH CENTRAL CO MTNS
THIS AFTERNOON RESULTING IN SCATTERED TO NUMEROUS SHOWERS AND
ISOLATED TO SCATTERED T-STORMS. WETBULB ZERO EXPECTED TO REMAIN
ABOVE MTN TOP LEVEL DURING THE DAYLIGHT HOURS...BUT STG
EVAPORATIVE COOLING WITH CONVECTION COULD GENERATE A BRIEF BUT
INTENSE SNOW SHOWER ABOVE TIMBERLINE. IT NOW APPEARS AS THOUGH THE
PLAINS WILL SEE ITS BEST SHOT AT PRECIP THIS EVENING...OR PERHAPS
AS EARLY AS LATE THIS AFTERNOON. THE HRRR SHOWS WEAK TO MODERATE
REFLECTIVITIES OVER THE I-25 URBAN CORRIDOR AS EARLY AS 21Z/TODAY...
WHILE AT THE SAME TIME THE WRF AND NAM ONLY INDICATE WIDELY
SCATTERED WEAK ECHOS OVER THE FOOTHILLS AND PALMER DIVIDE.
HOWEVER ALL 3 MODELS INDICATE SEVERAL AREAS OF LIGHT TO MODERATE
REFLECTIVITY/QPF OVER THE FRONT RANGE AND OUT ACROSS THE NERN
PLAINS THIS EVENING. COULD SEE A FEW STRONG T-STORMS POP ON THE
PLAINS AROUND 00Z/MON JUST AHEAD OF THE COLD FRONT. NAM AND RAP
INDICATE AN ELONGATED AREA OF 750-1000 J/KG CAPE EXTENDING FROM
ELBERT COUNTY TO LOGAN COUNTY AROUND 00Z.
NAM AND GFS INDICATE THE GREATEST REFLECTIVITIES/QPF IN THE
N-CENTRAL MTNS AROUND SUMMIT COUNTY FROM 00Z-06Z THIS EVENING
WITH CAA FOLLOWING THE PASSAGE OF THE 700-500 TROUGH AXIS. QPF
TOTALS UP ALONG THE CONTINENTAL DIVIDE ON THE ORDER OF 0.35 TO
0.60 INCH BY MORNING. MODEL SNOW TOTALS RANGE FROM 1-4 INCHES IN
AREAS ROUGHLY ABOVE 9500 FEET. ELSEWHERE...SHOULD SEE AN END TO
THE SHOWERY PRECIP OVER AND NEAR THE EAST FACE OF THE FRONT RANGE
BY AROUND MIDNIGHT WITH THE DRYING EFFECTS OF DOWNSLOPE FLOW.
HOWEVER...FARTHER OUT ON THE PLAINS A TIGHT BAROCLINIC ZONE AND
LINGERING QG ASCENT ON THE BACKSIDE OF THE UPPER LOW WILL PROBABLY
KEEP LIGHT TO MODERATE PRECIP GOING THROUGHOUT THE NIGHT. RAIN
AMOUNTS IN THIS AREA BY MORNING GENERALLY UNDER A HALF INCH...WITH
LESSER AMOUNTS CLOSER IN TO THE FOOTHILLS. FLOODING IS NOT A
CONCERN AT THIS TIME.
TEMPERATURES TODAY ARE EXPECTED TO BE SLIGHTLY COOLER THAN YESTERDAY
BUT STILL SLIGHTLY ABOVE AVERAGE FOR THE DATE. HIGHS ON THE PLAINS
WILL RANGE FROM THE MID-70S NEAR THE FOOTHILLS TO THE MID-80S NEAR
THE NORTHEAST CORNER OF THE STATE. HIGH COUNTRY MAX TEMPS WILL RANGE
FROM THE MID-60S IN THE VALLEYS AND FOOTHILLS...TO AROUND 50 DEGS
ABOVE TIMBERLINE. TONIGHTS LOWS WILL RANGE FROM THE MID 40S/LOWER
50S ON THE PLAINS TO THE 20S/30S IN THE HIGH COUNTRY. GUSTY NWLY
WINDS OVER THE NRN FRONT RANGE OVERNIGHT MAY MAKE IT FEEL EVEN
COLDER THAN THAT.
.LONG TERM...RATHER POTENT UPPER LEVEL TROUGH WILL MOVE QUICKLY ACROSS
THE AREA MON MORNING. LOOKS LIKE THIS SYSTEM MAY CLOSE OFF OVER
ERN CO AND THEN MOVE INTO SWRN NE BY MIDDAY. WILL HAVE SOME
FAVORABLE MID LVL QG ASCENT MON MORNING OVER NERN CO WHICH SHOULD
LEAD TO A GOOD CHC OF SHOWERS OVER THE PLAINS. ALONG THE FRONT
RANGE THE LOW LVL FLOW WILL BE STG NWLY WHICH WILL LIMIT PCPN
CHANCES. IN THE MTNS WILL SEE SOME LINGERING SNOW SHOWERS IN THE
MORNING BUT ACTIVITY SHOULD END BY MIDDAY AS DRIER AIR SPREADS
ACROSS. AS THE UPPER LEVEL LOW INTENSIFIES OVER SWRN NE AND DECENT
SFC GRADIENT OCCURS WILL SEE GUSTY NWLY WINDS IN THE NRN FOOTHILLS
AND ACROSS THE PLAINS. FOR NOW WILL KEEP SPEEDS BLO HIGH WIND
CRITERIA. AS FOR HIGHS WILL KEEP READINGS IN THE UPPER 60S TO
LOWER 70S OVER NERN CO.
BY MON EVENING THE UPPER LEVEL SYSTEM WILL MOVE QUICKLY EASTWARD
WITH DIMINISHING WINDS AND PCPN ENDING OVER THE FAR NERN PLAINS.
FOR TUE AND WED THE FLOW ALOFT WILL BECOME MORE SWLY AS ANOTHER
UPPER LEVEL TROUGH DEVELOPS OVER THE WRN US. THIS WILL LEAD TO A
DRY WX PTRN WITH WARMER TEMPS. HIGHS BY WED WILL BE IN THE LOWER TO
MID 80S OVER NERN CO.
BY THU ONE PIECE OF THE UPPER LEVEL TROUGH OVER THE WRN US WILL
MOVE ACROSS THE NRN ROCKIES WHILE A SECOND PIECE OF ENERGY MOVES
INTO THE GREAT BASIN. THIS WILL LEAVE NRN CO IN SWLY FLOW ALOFT.
SOME MOISTURE WILL INCREASE IN THE MTNS HOWEVER IT APPEARS BEST
CHC OF PCPN THU AFTN WILL STAY MAINLY OVER WRN CO THRU THU NIGHT.
HIGHS ON THU WILL REMAIN ABV NORMAL OVER NERN CO.
FOR FRI THE UPPER LEVEL TROUGH OVER THE GREAT BASIN WILL BEGIN TO
MOVE EAST AS A COLD FRONT MOVES INTO NERN CO. SHOULD SEE A GOOD
CHANCE OF RAIN AND SNOW IN THE MTNS WITH A CHC OF RAIN OVER NERN CO.
HIGHS ON FRI WILL TURN COOLER WITH READINGS IN THE 60S OVER THE
PLAINS. THE UPPER LEVEL TROUGH WILL MOVE EAST OF THE AREA BY SAT
WITH DRIER WEATHER AND SEASONAL TEMPERATURES.
&&
.AVIATION...SCATTERED HIGH CLOUDS EARLY THIS MORNING OVER THE
DENVER METRO AREA WILL GRADUALLY LOWER AS CLOUDS INCREASE IN
ADVANCE OF A PACIFIC COLD FRONT AND UPPER LEVEL LOW PRESSSURE
TROUGH TO OUR WEST. SOUTH-SOUTHWEST SFC WINDS OF 6-13KTS THIS
MORNING WILL GRADUALLY TURN EAST-SOUTHEASTERLY LATE MORNING/EARLY
AFTERNOON AS THE SURFACE TROUGH ALONG THE FOOTHILLS DEEPENS AHEAD
OF THE COLD FRONT. WESTERN PORTIONS OF THE DENVER METRO AREA
INCLUDING APA COULD SEE ISOLATED TO SCATTERED RAIN SHOWERS/
T-STORMS FORMING AFTER 21Z TODAY WITH THE ATMOSPHERE BECOMING
INCREASINGLY UNSTABLE. HOWEVER IT APPEARS THAT DENVER AREA
TERMINALS WILL SEE THEIR BEST CHANCE FOR SHOWERS/T-SHOWERS THIS
EVENING FROM 00Z-06Z JUST PRIOR TO AND SHORTLY AFTER PASSAGE OF
THE PACIFIC COLD FRONT. THE STRONGEST STORMS WILL LIKELY FORM
EAST OF THE METRO AREA WHERE THE LOWER ATMOSPHERE WILL BE MORE
MOIST AND UNSTABLE. CLOUD CEILINGS COULD BRIEFLY LOWER TO AROUND
5000 FT AGL WITH MODERATE RAINFALL THIS EVENING. EXPECT WINDS
AROUND SHOWERS/T-SHOWERS TO ALSO BE QUITE GUSTY AND VARIABLE IN
DIRECTION. CEILINGS SHOULD BEGIN RISING WITH SHOWERS ENDING AFTER
MIDNIGHT AS DRIER AIR MOVES IN BEHIND THE COLD FRONT.
HOWEVER...DIA COULD POSSIBLY SEE CIGS LOWERING AGAIN TO AROUND
3000 FT AGL WITH STRATUS TOWARDS MORNING. THE STRATUS WILL BE A
PRODUCT OF MOIST OUTFLOW FROM SHOWERS FARTHER OUT ON THE PLAINS.
&&
.HYDROLOGY...SCATTERED TO LIKELY SHOWERS AND ISOLATED TO SCATTERED
THUNDERSTORMS IN THE HIGH COUNTRY THIS AFTERNOON COULD PRODUCE
RAINFALL AMOUNTS RANGING FROM A QUARTER TO ONE-HALF INCH. SIMILAR
RAIN AMOUNTS ARE POSSIBLE ON THE PLAINS AND OVER THE FOOTHILLS
LATE THIS AFTERNOON AND EVENING. SHOWERS AND STORMS WILL MOVE
FAIRLY QUICKLY TODAY AND SO THE RISK OF HEAVY RAINFALL LEADING TO
FLASH FLOODING IS LOW. IN THE HIGH COUNTRY...ELEVATIONS ABOVE
AROUND 9500 FEET COULD SEE 2-4 INCHES OF SNOW ACCUMULATE BY
MORNING. AREAS ABOVE TIMBERLINE AS WELL AS WEST AND NORTHWEST
FACING SLOPES ARE IN THE BEST POSITION TO SEE THIS ACCUMULATION.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....RPK
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS NEW YORK NY
137 PM EDT SUN SEP 22 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE CONTROLS OF OUR WEATHER THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BASIC FORECAST ON TRACK. MINOR CHANGES TO SKY COVER AND DEW POINT
TEMPERATURES WITH THIS UPDATE. CLOUDS FROM LOW LEVEL INSTABILITY
ARE SOMEWHAT MORE THAN EXPECTED. INCREASED SKY COVER GRIDS ABOUT
20 PERCENT ON AVERAGE USING LATEST 15Z RAP AS THE BASELINE.
TEMPS ON TRACK FOR HOLDING NEARLY STEADY THIS AFTERNOON IN THE
UPPER 60S TO LOWER 70S. DEW POINTS IN THE MID 40S SPREADING EAST
ACROSS LI AND CT.
RIP CURRENT RISK WAS LOWERED TO MODERATE BASED ON LATEST
OBSERVATIONS AND FORECAST DATA. LIFEGUARDS ARE NOT ON DUTY AT MOST,
IF NOT ALL OCEAN BEACHES. SWIMMING IS NOT RECOMMENDED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
UPPER TROUGH CLOSES OFF AND GETS BLOCKED OVER THE CANADIAN
MARITIMES. UPPER RIDGE BUILDS TO THE WEST OF THE AREA...AS SFC HIGH
BUILDS ACROSS THE GREAT LAKES.
INSTABILITY CLOUDS DISSIPATE WITH THE LOSS OF HEATING THIS
EVENING. WINDS STAY UP OVERNIGHT AS CAA CONTINUES WITH A SLIGHTLY
STRONGER PRESSURE GRADIENT FORCE. THIS KEEPS TEMPS IN THE 40S TO
AROUND 50 IN NYC.
THE FIRST FULL DAY OF FALL FEATURES TEMPS 5-7 DEGREES BELOW NORMAL
UNDER COBALT BLUE SKIES AND A FEW WEATHER STRATO-CU.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
UPPER LEVEL BLOCKED ACROSS THE CANADIAN MARITIMES THROUGH MID WEEK.
THERE WILL BE A SPLIT IN THE FLOW WITH A WEAKENING RIDGE MOVING
ACROSS THE REGION FROM EARLY TO MID WEEK WITH CANADIAN HIGH PRESSURE
BUILDING IN AT THE SURFACE. THEN A DAMPENED UPPER LEVEL SHORTWAVE
PUSHES TO THE SOUTH OF THE REGION WEDNESDAY AND THURSDAY WITH A
WEAKENING OF THE SURFACE PRESSURE FIELD. THIS WILL RESULT IN SOME
MORE CLOUDS FOR THAT TIME FRAME. ANOTHER RIDGE BUILDS IN FROM THE
WEST THURSDAY NIGHT THROUGH EARLY NEXT WEEKEND...REINFORCING
SUBSIDENCE WITH ANOTHER CANADIAN HIGH PRESSURE AREA AT THE SURFACE
BUILDING IN.
THIS WILL BE A QUIET WEATHER PERIOD WITH DRY CONDITIONS AND NEAR TO
SLIGHTLY BELOW NORMAL TEMPERATURES MUCH OF THE TIME. HOWEVER...THE
END OF THE WEEK WILL SEE A SLIGHT WARMING TREND TO SLIGHTLY ABOVE
NORMAL TEMPS. EXPECTING THE NIGHT TIME PERIODS TO EXPERIENCE GOOD
RADIATIONAL COOLING CONDITIONS MONDAY NIGHT THROUGH WEDNESDAY
NIGHT...WITH MONDAY NIGHT BEING THE COLDEST NIGHT. INTERIOR
AREAS...WHERE WINDS WILL BE LIGHTER...COULD SEE SOME PATCHY FROST
LATE MONDAY NIGHT INTO EARLY TUESDAY MORNING.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
HIGH PRES BUILDS INTO THE REGION.
NW WINDS AT AROUND 15 KT WITH GUSTS UP TO 20 KT. FOR
KJFK/KLGA/KEWR...WINDS WILL BE TO THE RIGHT OF 310 MAGNETIC
THROUGH THIS EVENING.
GUSTS END AFT 23Z. NW WINDS AROUND 15 KT WITH GUSTS UP TO 20 KT
AFT 14Z MONDAY.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
.MONDAY AFTERNOON...VFR. NW WINDS GUSTING TO 20 KT.
.TUESDAY THROUGH FRIDAY...VFR.
&&
.MARINE...
NW WINDS SHOULD BELOW SCA CONDITIONS THIS AFTERNOON WITH NW GUSTS
TO AROUND 20 KT. THIS SUBSIDE SLIGHTLY TOWARD LATE AFTN.
A TIGHTENING OF THE PRESSURE GRADIENT THIS EVENING RESULTS IN 25
KT GUSTS ALL WATERS (SCA ADVISORY UP FOR THIS)...THEN WINDS
DIMINISH BELOW SCA LEVELS BY SUNRISE.
TRANQUIL WEATHER CONDITIONS ARE FCST FOR MONDAY THROUGH THURSDAY WITH
WINDS AND SEAS REMAINING BELOW SMALL CRAFT ADVISORY LEVELS.
&&
.HYDROLOGY...
DRY THROUGH THE WEEK.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY BROADCAST
CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION
KWO35 REMAINS OUT OF SERVICE. THE NATIONAL WEATHER SERVICE IS WORKING
WITH SEVERAL U.S. GOVERNMENT AGENCIES TO ISOLATE AND RESOLVE THIS TECHNICAL
PROBLEM.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE INTERMITTENTLY
FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO DURING POTENTIALLY DANGEROUS
WEATHER SITUATIONS...FOR ROUTINE WEEKLY TESTS OF THE WARNING SYSTEM...AND
TO DETERMINE IF THE INTERFERENCE ISSUE HAS BEEN RESOLVED.
THE KOKX WSR-88D DUAL POLE RAINFALL ESTIMATES WERE INFLATED BY A
FACTOR OF 3 OR MORE DURING LAST NIGHT`S PCPN EVENT. TECHNICIANS
WILL INVESTIGATE THIS ON MONDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EDT MONDAY
FOR ANZ330-335-338-340-345-355.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...TONGUE
NEAR TERM...TONGUE
SHORT TERM...TONGUE/PW
LONG TERM...JM/PW
AVIATION...MPS
MARINE...TONGUE
HYDROLOGY...TONGUE
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1252 PM EDT SUN SEP 22 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE CONTROLS OF OUR WEATHER THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BASIC FORECAST ON TRACK. MINOR CHANGES TO SKY COVER AND DEW POINT
TEMPERATURES WITH THIS UPDATE. CLOUDS FROM LOW LEVEL INSTABILITY
ARE SOMEWHAT MORE THAN EXPECTED. INCREASED SKY COVER GRIDS ABOUT
20 PERCENT ON AVERAGE USING LATEST 15Z RAP AS THE BASELINE.
TEMPS ON TRACK FOR HOLDING NEARLY STEADY THIS AFTERNOON IN THE
UPPER 60S TO LOWER 70S. DEW POINTS IN THE MID 40S SPREADING EAST
ACROSS LI AND CT.
RIP CURRENT RISK WAS LOWERED TO MODERATE BASED ON LATEST
OBSERVATIONS AND FORECAST DATA. LIFEGUARDS ARE NOT ON DUTY AT MOST,
IF NOT ALL OCEAN BEACHES. SWIMMING IS NOT RECOMMENDED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
UPPER TROUGH CLOSES OFF AND GETS BLOCKED OVER THE CANADIAN
MARITIMES. UPPER RIDGE BUILDS TO THE WEST OF THE AREA...AS SFC HIGH
BUILDS ACROSS THE GREAT LAKES.
INSTABILITY CLOUDS DISSIPATE WITH THE LOSS OF HEATING THIS
EVENING. WINDS STAY UP OVERNIGHT AS CAA CONTINUES WITH A SLIGHTLY
STRONGER PRESSURE GRADIENT FORCE. THIS KEEPS TEMPS IN THE 40S TO
AROUND 50 IN NYC.
THE FIRST FULL DAY OF FALL FEATURES TEMPS 5-7 DEGREES BELOW NORMAL
UNDER COBALT BLUE SKIES AND A FEW WEATHER STRATO-CU.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
UPPER LEVEL BLOCKED ACROSS THE CANADIAN MARITIMES THROUGH MID WEEK.
THERE WILL BE A SPLIT IN THE FLOW WITH A WEAKENING RIDGE MOVING
ACROSS THE REGION FROM EARLY TO MID WEEK WITH CANADIAN HIGH PRESSURE
BUILDING IN AT THE SURFACE. THEN A DAMPENED UPPER LEVEL SHORTWAVE
PUSHES TO THE SOUTH OF THE REGION WEDNESDAY AND THURSDAY WITH A
WEAKENING OF THE SURFACE PRESSURE FIELD. THIS WILL RESULT IN SOME
MORE CLOUDS FOR THAT TIME FRAME. ANOTHER RIDGE BUILDS IN FROM THE
WEST THURSDAY NIGHT THROUGH EARLY NEXT WEEKEND...REINFORCING
SUBSIDENCE WITH ANOTHER CANADIAN HIGH PRESSURE AREA AT THE SURFACE
BUILDING IN.
THIS WILL BE A QUIET WEATHER PERIOD WITH DRY CONDITIONS AND NEAR TO
SLIGHTLY BELOW NORMAL TEMPERATURES MUCH OF THE TIME. HOWEVER...THE
END OF THE WEEK WILL SEE A SLIGHT WARMING TREND TO SLIGHTLY ABOVE
NORMAL TEMPS. EXPECTING THE NIGHT TIME PERIODS TO EXPERIENCE GOOD
RADIATIONAL COOLING CONDITIONS MONDAY NIGHT THROUGH WEDNESDAY
NIGHT...WITH MONDAY NIGHT BEING THE COLDEST NIGHT. INTERIOR
AREAS...WHERE WINDS WILL BE LIGHTER...COULD SEE SOME PATCHY FROST
LATE MONDAY NIGHT INTO EARLY TUESDAY MORNING.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
VFR AS HIGH PRESSURE BUILDS IN WITH NW FLOW.
FOR JFK...LGA AND EWR: WINDS STAY RIGHT OF 310 MAGNETIC THROUGH
THIS EVENING WITH GUSTS TO AROUND 20 KT.
OUTLOOK FOR 18Z MONDAY THROUGH THURSDAY...
.MON AFTN...VFR WITH NNW WND AROUND 15 KT.
.TUE THROUGH THU...VFR.
&&
.MARINE...
NW WINDS SHOULD BELOW SCA CONDITIONS THIS AFTERNOON WITH NW GUSTS
TO AROUND 20 KT. THIS SUBSIDE SLIGHTLY TOWARD LATE AFTN.
A TIGHTENING OF THE PRESSURE GRADIENT THIS EVENING RESULTS IN 25
KT GUSTS ALL WATERS (SCA ADVISORY UP FOR THIS)...THEN WINDS
DIMINISH BELOW SCA LEVELS BY SUNRISE.
TRANQUIL WEATHER CONDITIONS ARE FCST FOR MONDAY THROUGH THURSDAY WITH
WINDS AND SEAS REMAINING BELOW SMALL CRAFT ADVISORY LEVELS.
&&
.HYDROLOGY...
DRY THROUGH THE WEEK.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY BROADCAST
CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION
KWO35 REMAINS OUT OF SERVICE. THE NATIONAL WEATHER SERVICE IS WORKING
WITH SEVERAL U.S. GOVERNMENT AGENCIES TO ISOLATE AND RESOLVE THIS TECHNICAL
PROBLEM.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE INTERMITTENTLY
FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO DURING POTENTIALLY DANGEROUS
WEATHER SITUATIONS...FOR ROUTINE WEEKLY TESTS OF THE WARNING SYSTEM...AND
TO DETERMINE IF THE INTERFERENCE ISSUE HAS BEEN RESOLVED.
THE KOKX WSR-88D DUAL POLE RAINFALL ESTIMATES WERE INFLATED BY A
FACTOR OF 3 OR MORE DURING LAST NIGHT`S PCPN EVENT. TECHNICIANS
WILL INVESTIGATE THIS ON MONDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EDT MONDAY
FOR ANZ330-335-338-340-345-355.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...TONGUE
NEAR TERM...TONGUE
SHORT TERM...TONGUE/PW
LONG TERM...JM/PW
AVIATION...MPS
MARINE...TONGUE
HYDROLOGY...TONGUE
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
450 AM EDT SUN SEP 22 2013
.SYNOPSIS...
WIDESPREAD RAIN WITH EMBEDDED HEAVIER SHOWERS AND AN ISOLATED
THUNDERSTORM WILL SWEEP ACROSS SOUTHERN NEW ENGLAND TODAY INTO
THIS EVENING ALONG AND AHEAD OF A COLD FRONT. OTHERWISE...HIGH
PRESSURE WILL RESULT IN AN EXTENDED PERIOD OF DRY WEATHER FOR THE
REST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
4 AM UPDATE...
SURFACE COLD FRONT...AS DISCERNED FROM DISTINCT FINE-LINE WITHIN
RADAR REFLECTIVITY...IS QUICKLY PRESSING EAST. CONTINUE TO MONITOR
WIDESPREAD RAIN WITH EMBEDDED HEAVIER SHOWERS ALONG AND AHEAD OF
THE FRONT WHICH ARE ALLOWING THE EFFECTIVE MIX-DOWN OF MOMENTUM TO
THE SURFACE THROUGH THE MORE STABLE BOUNDARY LAYER. WITNESSING
GUSTS AROUND 25 MPH PRIOR TO AND DURING PASSAGE OF THE COLD FRONT
WITH BREEZY SOUTHERLY FLOW BACKING OUT OF THE WEST AND IMMEDIATELY
BECOMING BLUSTERY.
ALSO CLOSELY WATCHING RADAR DERIVED ONE-HOUR RAINFALL AMOUNTS.
CONSIDERING NOTHING EXCEEDING ONE-INCH IN AN HOUR...COMBINED WITH
THE FACT THAT IT HASN/T RAINED FOR SEVERAL DAYS AND THE SYSTEM
ITSELF IS QUICKLY PROGRESSING THROUGH THE REGION...FEEL THE THREAT
OF ANY FLOODING IS SUBSTANTIALLY REDUCED AND SO WILL REMOVE ANY
FURTHER MENTION FROM THIS DISCUSSION. STILL CAN NOT RULE OUT TOTAL
RAINFALL AMOUNTS WITH CONCLUSION OF THE SYSTEM TO EXCEED ONE INCH.
FAVORING THE 23.0Z NAM WITH THE 22.21Z SREF...AND INCORPORATING
THE LATEST HRRR THOUGH ADJUSTING IT 2 HOURS FASTER...HAVE UPDATED
POP AND RAINFALL ACCUMULATION GRIDS ACCORDINGLY. CONTINUE AN
ISOLATED MENTION OF THUNDER.
TODAY...
CONTINUED STRONG DYNAMICS AND SUBSTANTIAL DEEP-LAYER MOISTURE ALONG
AND AHEAD OF A SURFACE COLD FRONT EXPECTED TO PUSH OFF CAPE COD BY
THE LATE AFTERNOON HOURS. SHOWERS LINGERING LONGEST ACROSS SOUTHEAST
NEW ENGLAND WITH THE POSSIBILITY OF A SECONDARY WEAK AREA OF LOW
PRESSURE IN VICINITY OF THE REGION ALONG THE COLD FRONT. WILL NEED
TO CLOSELY WATCH FOR AN INFLECTION POINT WITHIN THE WATER VAPOR
SATELLITE LOOP.
CONSIDERING PWATS UP TO 1.75 INCHES AND WEAK INSTABILITY SNEAKING
NORTHWARD INTO SOUTHERN NEW ENGLAND...EXPECT POCKETS OF HEAVY RAIN
WITH ISOLATED THUNDERSTORMS. THIS PRESENTS THE THREAT OF LOCALIZED
URBAN AND POOR DRAINAGE FLOODING MAINLY FOR AREAS EAST OF THE
CONNECTICUT RIVER VALLEY.
DRY SLOT WORKING INTO THE REAR OF THE MID-LEVEL LOW AS WINDS BACK
OUT OF THE WEST-NORTHWEST IMMEDIATELY BEHIND THE FRONT BECOMING
BLUSTERY. WILL SEE CONDITIONS CLEAR RATHER QUICKLY WITH COLD AIR
ADVECTION PROCEEDING WITHIN THE LOW- TO MID-LEVELS. THIS WILL KEEP
HIGHS AROUND THE UPPER-60S TO LOW-70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY MORNING/...
NORTHWESTERLY FLOW DIMINISHING...BUT CAN/T RULE OUT CONTINUED
BLUSTERY CONDITIONS ALONG THE NEAR-SHORE AND ADJACENT WATERS. MOSTLY
CLEAR CONDITIONS PREVAIL WITH THE POSSIBILITY OF SOME LOW- TO MID-
LEVEL CLOUDS ACROSS N/W NEW ENGLAND IN PROXIMITY TO THE CYCLONIC
DEEP LOW /OROGRAPHIC UPSLOPE OF REMNANT MOISTURE/.
COLDER AIMASS BUILDING SOUTH AND EAST OVER THE REGION /H85 AROUND
+4C/. WESTERLY FLOW AIDING COLD AIR ADVECTION PROCESSES. FAIRLY
CHILLY NIGHT...BUT NOT RECORD BREAKING. LOWS AROUND THE LOW- TO MID-
40S...WITH HIGHER ELEVATIONS INTO THE UPPER 30S.
MINIMUM TEMPERATURE RECORDS FOR SEPTEMBER 23RD:
BOSTON 35 /1904/
HARTFORD 34 /1974/
PROVIDENCE 38 /1974/
WORCESTER 32 /1904/
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
HIGHLIGHTS...
* DRY WEATHER THROUGH NEXT SATURDAY
* BELOW NORMAL TEMPS MON/TUE MODERATE TO NEAR NORMAL BY MID WEEK
DETAILS...
MONDAY...
CLOSED LOW OVER THE CANADIAN MARITIMES WILL RESULT IN A NORTHWEST
FLOW OF DRY BUT COOL WEATHER. 850 MB TEMPS DROPPING TO BELOW +4C
SHOULD KEEP HIGHS IN THE UPPER 50S ACROSS THE INTERIOR HIGH
TERRAIN...TO THE LOWER TO MIDDLE 60S ELSEWHERE UNDER A MIXTURE OF
CLOUDS AND SUNSHINE. THESE HIGHS ARE AROUND 10 DEGREES BELOW NORMAL
FOR LATE SEPTEMBER.
MONDAY NIGHT...
WINDS DIMINISH AND WITH MOSTLY CLEAR SKIES IN
PLACE...EXPECT A GOOD NIGHT OF RADIATIONAL COOLING. LOW TEMPS
SHOULD BOTTOM OUT IN THE MIDDLE 30S ACROSS THE NORMALLY COOLEST
OUTLYING LOCATIONS...TO THE LOWER TO MIDDLE 40S IN MANY OF THE URBAN
CENTERS. THE MILD SPOT WILL LIKELY BE THE URBAN HEAT ISLAND OF
BOSTON WITH EXPECTED LOWS IN THE UPPER 40S. THERE IS A MODERATE
PROBABILITY WILL NEED FROST ADVISORIES FOR PORTIONS OF SOUTHWEST
NH/WESTERN MA LATE MON NIGHT/EARLY TUE AM...BUT ITS A 4TH PERIOD
EVENT SO NO HEADLINES AT THIS TIME.
TUESDAY....
DESPITE A CHILLY EARLY START...SUNSHINE AND SOME MID LEVEL WARMING
WILL ALLOW FOR A NICE RECOVERY IN TEMPS BY AFTERNOON. HIGHS SHOULD
TOP OUT WELL INTO THE 60S ACROSS MOST LOCATIONS.
WEDNESDAY THROUGH SATURDAY...
CLOSED UPPER LEVEL LOW ACROSS THE
CANADIAN MARITIMES WILL LIFT A BIT FURTHER TO THE NORTH. THIS WILL
ALLOW TEMPS TO MODERATE BACK TO NEAR NORMAL LEVELS...WITH HIGHS
MAINLY IN THE UPPER 60S AND LOWER 70S. HOWEVER...THE TRUE
SUMMERLIKE TEMPS SHOULD REMAIN TO OUR WEST WHERE HEIGHT FIELDS WILL
BE HIGHER. AS FOR PRECIP CHANCES...UPPER LEVEL TROUGH AXIS WILL
REMAIN EAST OF OUR REGION SO EXPECT AN EXTENDED PERIOD OF DRY
WEATHER OVER THIS TIME.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...
8Z UPDATE...
MVFR/IFR PREVAILING WITH RAIN. COULD SEE ISOLATED POCKETS OF
LIFR/VLIFR WITH DENSE FOG AND/OR +RA ALONG AND AHEAD OF A COLD
FRONT SWEEPING ACROSS THE TERMINALS...EXPECCTED TO BE OFFSHORE OF
CAPE COD BY LATE AFTERNOON. BREEZY SOUTHERLY WINDS WILL BACK OUT
OF THE WEST WITH FRONTAL PASSAGE AND IMMEDIATELY BECOME BLUSTERY.
GUSTS AROUND 25 KTS. LLWS ISSUES CONTINUE AS WINDS JUST 2 KFT AGL
REMAIN AROUND 40 KTS PER TAUNTON RADAR WIND PROFILER.
WILL SEE IMMEDIATE IMPROVEMENT THROUGH THE DAY AS THE COLD FRONT
AND ATTENDANT WET WEATHER SLIDE EAST. VFR EXPECTED BY EVENING AND
OVERNIGHT. LIGHTER WESTERLY WINDS COULD PRESENT THE OPPORTUNITY
FOR PATCHY DENSE FOG IN SHELTERED VALLEY REGIMES /CONNECTICUT
RIVER VALLEY...MONADNOCKS...WORCESTER HILLS/.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY DUE TO TIMING.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY DUE TO TIMING.
OUTLOOK...MONDAY THROUGH THURSDAY...
HIGH CONFIDENCE IN MAINLY VFR CONDITIONS. THE EXCEPTION WILL BE
PATCHY LATE NIGHT/EARLY MORNING GROUND FOG IN THE TYPICALLY PRONE
LOCATIONS AT TIMES.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.
4 AM UPDATE...
SURFACE COLD FRONT SLIDING THROUGH THE WATERS DURING THE COURSE OF
TODAY INTO THIS EVENING. BREEZY SOUTHERLY FLOW AHEAD OF THE FRONT
WITH HEAVY /VISIBILITY REDUCING/ RAIN AND GUSTS UP TO AROUND 25
KTS...WHICH WILL BE IMMEDIATELY FOLLOWED BY BLUSTERY WESTERLY
WINDS WITH GUSTS UP TO 25 KTS DURING FRONTAL PASSAGE. WESTERLY
WINDS DIMINISH AS THE FRONT PROGRESSES FURTHER EAST.
HAVE EXTENDED THE SMALL CRAFT ADVISORIES ACCORDINGLY THROUGH
MONDAY MORNING FOR THE OUTER WATERS. WILL SEE THE INNER WATERS
DROP OFF IN STAGES AS THE COLD FRONT MOVES FURTHER TO THE EAST.
EXPECT THE THREATS OF WIND GUSTS UP TO AROUND 25 KTS AND SEAS AS
HIGH AS 7 FEET ON THE OUTER WATERS.
OUTLOOK...MONDAY THROUGH THURSDAY...
HIGH CONFIDENCE. MARGINAL 5 FOOT SEAS AND LOW 20 KNOT NORTHWEST
WIND GUSTS MAY FLIRT WITH OUT EASTERN ATLANTIC WATERS AT TIMES MON
INTO EARLY TUE. THIS A RESULT OF COOL ADVECTION PROMOTING GOOD
MIXING OVER THE RELATIVELY MILD OCEAN. OTHERWISE...WINDS/SEAS
SHOULD REMAIN BELOW SCA THE REST OF THIS PERIOD.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR
ANZ231>234-236-251.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ235-
237.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ250-254>256.
&&
$$
SYNOPSIS...FRANK/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...FRANK
AVIATION...FRANK/SIPPRELL
MARINE...FRANK/SIPPRELL
AREA FORECAST DISCUSSION
NWS ALBANY NY
142 AM EDT SUN SEP 22 2013
.SYNOPSIS...
WIDESPREAD SHOWERS ARE EXPECTED TONIGHT AS A COLD FRONT
APPROACHES AND CROSSES THE REGION. THE RAIN MAY BE HEAVY AT TIMES
TONIGHT. HIGH PRESSURE WILL BEGIN TO BUILD INTO THE REGION BY SUNDAY
NIGHT AND IS THEN EXPECTED TO DOMINATE THE WEATHER MUCH OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1225 AM EDT...A COLD FRONT IS MOVING TOWARDS OUR FORECAST
AREA FOR THE OVERNIGHT HOURS. AHEAD OF THIS BOUNDARY IS A BAND OF
LIGHT TO MODERATE RAIN SHOWERS ALONG WITH A NARROW PRE FRONTAL
RAIN BAND CONTAINING HEAVY RAIN. THE LATEST 3KM HRRR SHOWS THIS
RAIN BAND NICELY AS IT MOVES EASTWARD FROM THE HUDSON VALLEY INTO
WESTERN NEW ENGLAND...AND THIS IS THE AREA MOST LIKELY TO SEE THE
HEAVIEST RAIN DURING THE REMAINDER OF THE OVERNIGHT HOURS. WE WILL
MENTION WIDESPREAD MODERATE RAIN SHOWERS FOR THE ENTIRE
REGION...ESP CONSIDERING HOW OUR PWATS HAVE RISEN TO 1.37 INCHES
ON THE 00Z KALY SOUNDING. MOST AREAS LOOK TO SEE A HALF INCH TO
ONE INCH OF RAIN...WITH LOCALLY HIGHER AMOUNTS OVER THE HIGH
TERRAIN OF WESTERN NEW ENGLAND. WITH LIMITED INSTABILITY AND NO
LTG STRIKES OVER THE LAST 6 HOURS...HAVE REMOVED MENTION OF
THUNDER FROM THE FORECAST AS WELL. RAIN SHOWERS LOOK TO END FROM
WEST TO EAST LATER TONIGHT AS THE FRONT CROSSES THE REGION AND THE
WINDS TURN WEST.
FLOODING OF RIVERS AND STREAMS IS NOT EXPECTED AT THIS TIME...HOWEVER
WITHIN BANK RISES OF SEVERAL FEET ARE POSSIBLE ON MAJOR RIVERS.
WHAT IS MORE LIKELY IS PONDING OF WATER AND FLOODING OF POOR
DRAINAGE AND LOW LYING AREAS...MAINLY ACROSS WESTERN NEW ENGLAND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
TROUGH AXIS WILL SWING THROUGH SUNDAY AS SHORT WAVE ROTATES THROUGH
BASED OF UPPER LEVEL LOW MOVING ACROSS EASTERN CANADA. PRECIPITATION
WILL TAPER OFF FROM SOUTHWEST TO NORTHEAST DURING THE MORNING HOURS.
THE PRESSURE GRADIENT WILL TIGHTEN UP ACROSS THE REGION SUNDAY AND
WESTERLY WINDS WILL BECOME BRISK USHERING IN A COLDER AIRMASS
AIRMASS. CONDITIONS WILL REALLY BEGIN TO IMPROVE LATER IN THE
AFTERNOON INTO EVENING WITH DECREASING CLOUDS AND WEAKENS WINDS AS
THE PRESSURE GRADIENT LOOSENS ACROSS THE REGION AND HEIGHTS BEGIN TO
RISE.
IT WILL GET COLD AT NIGHT WITH LOWS BOTTOMING OUT MAINLY IN THE 30S.
DESPITE THE COLD TEMPERATURES CONDITIONS WILL BE FAVORABLE FOR
WIDESPREAD FROST DEVELOPMENT AS WE MAINTAIN A NORTHWEST WIND THROUGH
THE OVERNIGHT...WEAKEN TO 5 TO 10 MPH. COLDER TEMPERATURES WILL BE
ACROSS THE HIGHER TERRAIN WHERE SOME CLOUDS COVER WILL LINGER.
RIDGING BUILDS IN AT SURFACE AND HEIGHTS WILL BE RISING ALOFT
MONDAY. HOWEVER...A STACKED LOW DEVELOPS OVER NORTHERN NEW ENGLAND
AND IT WILL MOVE LITTLE THROUGH TUESDAY. THIS WILL MAINTAIN A
NORTHWESTERLY FLOW OVER THE REGION.
DESPITE LOTS OF SUNSHINE MONDAY...THE FIRST FULL OF DAY OF FALL WILL
BE CHILLY. HIGHS ARE ONLY EXPECTED TO BE IN THE LOWER 50S TO LOWER
60S...AROUND 10 DEGREES BELOW NORMAL. IN ADDITION...WE WILL HAVE A
BRISK NORTHWESTERLY WINDS WHICH WILL MAKE IT FEEL EVEN COLDER.
CONDITIONS WILL BE MORE FAVORABLE FOR WIDESPREAD FROST MONDAY NIGHT
WITH MOSTLY CLEAR SKIES AND WINDS DIMINISHING LATE AT NIGHT. LOOKING
FOR LOWS IN THE 30S WITH THE COLDER TEMPERATURES ACROSS THE HIGHER
TERRAIN.
TEMPERATURES WILL MODERATE CLOSER TO SEASONABLE LEVELS TUESDAY...BUT
REMAIN BELOW NORMAL BY 5 TO 10 DEGREES. OUR REGION WILL BE
SANDWICHED BETWEEN THE RIDGE AXIS TO OUR WEST ACROSS THE OHIO VALLEY
AND GREAT LAKES REGION AND THE LARGE STACKED LOW WOBBLING OVER
NORTHERN NEW ENGLAND.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MUCH OF THE EXTENDED PERIOD WILL FEATURE QUIET WEATHER WITH
TEMPERATURES MODERATING ABOVE NORMAL.
AT THE START OF THE EXTENDED PERIOD...A CUTOFF UPPER LEVEL LOW OVER
ATLANTIC CANADA WILL BE DEPARTING OUT TO SEA...WHILE AN UPPER LEVEL
RIDGE WILL BE SITUATED OVER THE MIDWEST AND GREAT LAKES REGION. WITH
CLEAR SKIES AND LIGHT WINDS...TEMPS WILL BE COOL ON TUES NIGHT/WED
MORNING...WITH 30S TO LOW 40S OVER MUCH OF THE AREA. THERE MAY BE
SOME FROST ISSUES FOR THOSE AREAS WHERE THE GROWING SEASON IS STILL
ONGOING...SUCH AS THE CATSKILLS OR SOUTHERN VT.
A WEAK UPPER LEVEL DISTURBANCE WILL ATTEMPT TO MOVE AROUND THE UPPER
RIDGING OVER THE GREAT LAKES FOR WED AND THURS...AND THE MODELS SHOW
DIFFERENCES IN EXACTLY WHERE IT MOVES. THE 12Z ECMWF SHOWS THIS
FEATURE SLIDING UNDER THE RIDGE TOWARDS THE SOUTHEAST...WHILE THE
12Z GFS WEAKENS AND FLATTENS THE RIDGE ENOUGH TO MOVE THE
DISTURBANCE ACROSS THE NORTHEAST. WITH THIS FEATURE BEING RATHER
WEAK AND MOISTURE STARVED...EITHER SCENARIO WOULD KEEP OUR REGION
DRY. MAX TEMPS WILL BE IN THE UPPER 60S TO LOW 70S FOR VALLEY
AREAS...WHICH IS NEAR TO SLIGHTLY ABOVE NORMAL.
BEHIND THAT WEAK UPPER LEVEL DISTURBANCE...BOTH MODELS SHOWS STRONG
RIDGING REESTABLISHING ITSELF ALONG THE EASTERN SEABOARD FOR FRIDAY
INTO SATURDAY. UNDER PLENTY OF SUNSHINE AND CONTINUED DRY
CONDITIONS...THIS SHOULD ALLOW MAX TEMPS TO REACH INTO THE 70S
ACROSS MOST OF THE REGION...WITH MID 70S FOR THE CAPITAL REGION AND
MID HUDSON VALLEY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 145 AM EDT...A BAND OF LIGHT TO MODERATE RAINFALL...WITH AN
EMBEDDED NARROW LINE OF HEAVY SHOWERS...CONTINUES TO AFFECT THE
REGION...WITH THE HEAVIER LINE OF SHOWERS NOW ENTERING WESTERN NEW
ENGLAND. CONDITIONS IN THE WAKE OF THE HEAVIER LINE OF SHOWERS WAS
MAINLY VFR TO MVFR. THE COLD FRONT WAS CURRENTLY CROSSING CENTRAL NYS.
THIS BAND OF SHOWERS WILL END FROM W TO E OVER THE NEXT 1-2 HOURS.
BETWEEN THIS BAND...AND THE COLD FRONT...A LIGHT SOUTHWEST WIND
WILL OCCUR WITH MAINLY MVFR CIGS. THERE IS A SLIGHT CHC THAT SOME
IFR CIGS COULD DEVELOP...ESP AT KPSF BEFORE THE COLD FRONT MOVES
ACROSS BETWEEN 08Z-10Z...AND FOR NOW...HAVE ONLY INDICATED IFR
CONDITIONS AT KPSF...WHICH COULD LINGER EVEN AFTER THE FRONTAL
PASSAGE DUE TO A DEVELOPING UPSLOPE WESTERLY FLOW OF MOIST AIR.
SOME SPOTTY LIGHT SHOWERS MAY PERSIST AT KGFL AND KALB THROUGH
SUNRISE IN THE WAKE OF THE FRONT.
AFTER SUNRISE...ANY MVFR/IFR CIGS SHOULD BECOME MAINLY VFR THROUGH
THE DAY. CONDITIONS SHOULD BECOME MOSTLY CLEAR LATER SUNDAY INTO
SUNDAY NIGHT AT KPOU...ALTHOUGH SOME PATCHY CLOUDS MAY LINGER
ELSEWHERE.
WINDS BRIEFLY SHIFTING INTO THE WEST AND GUSTED UP TO 25-30 KT
WITH THE INITIAL LINE OF HEAVIER SHOWERS. IN ITS WAKE...WINDS
SHIFT BACK INTO THE SOUTH TO SOUTHWEST AHEAD OF THE INCOMING COLD
FRONT...WITH SPEEDS GENERALLY LESS THAN 8 KT. EXPECT WINDS TO
SHIFT BACK INTO THE WEST TO NORTHWEST ONCE THE FRONT PASSES
BETWEEN 08Z-10Z AT 8-12 KT. WEST TO NORTHWEST WINDS WILL PERSIST
THROUGH SUNDAY AT 8-12 KT...WITH OCCASIONAL GUSTS OF 20-25
KT...ESP AT KALB AND KPSF. WIND SPEEDS SHOULD GRADUALLY DIMINISH
AFTER SUNSET TO 10 KT OR LESS.
OUTLOOK...
SUNDAY NIGHT-THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
WIDESPREAD PRECIPITATION TONIGHT INTO SUNDAY AS A COLD FRONT
APPROACHES AND CROSSES THE REGION. HIGH PRESSURE WILL BEGIN TO
BUILD INTO THE REGION SUNDAY NIGHT AND IS THEN EXPECTED TO
DOMINATE THE WEATHER MUCH OF NEXT WEEK.
&&
.HYDROLOGY...
WIDESPREAD PRECIPITATION TONIGHT AS A COLD FRONT APPROACHES AND
CROSSES THE REGION. PRECIPITABLE WATERS VALUES ARE EXPECTED TO
INCREASE TO AROUND 1 1/2 INCHES AHEAD OF THE FRONTAL BOUNDARY WHICH
IS ABOUT 1 1/2 STANDARD DEVIATIONS ABOVE NORMAL. RAINFALL AMOUNTS OF
1 TO 1 1/2 INCHES ARE EXPECTED WITH LOCALLY HIGHER AMOUNTS OF 2 TO
POSSIBLY 3 INCHES. FLOODING OF RIVERS AND STREAMS IS NOT EXPECTED AT
THIS TIME...HOWEVER WITHIN BANK RISES OF SEVERAL FEET ARE POSSIBLE
ON MAJOR RIVERS. WHAT IS LIKELY IS PONDING OF WATER AND FLOODING OF
POOR DRAINAGE AND LOW LYING AREAS. CAN NOT RULE OUT ISOLATED FLASH
FLOODING.
THE UPPER LOW AND TROUGH AXIS WILL MOVE ACROSS THE REGION SUNDAY.
THE STEADY PRECIPITATION WILL TAPER OFF FROM SOUTHWEST TO
NORTHEAST DURING THE MORNING HOURS. HIGH PRESSURE WILL BEGIN TO
BUILD INTO THE REGION SUNDAY NIGHT AND IS THEN EXPECTED TO
DOMINATE THE WEATHER MUCH OF NEXT WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/FRUGIS
NEAR TERM...IAA/FRUGIS/11
SHORT TERM...IAA
LONG TERM...FRUGIS
AVIATION...KL/FRUGIS
FIRE WEATHER...IAA
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1228 AM EDT SUN SEP 22 2013
.SYNOPSIS...
WIDESPREAD SHOWERS ARE EXPECTED TONIGHT AS A COLD FRONT
APPROACHES AND CROSSES THE REGION. THE RAIN MAY BE HEAVY AT TIMES
TONIGHT. HIGH PRESSURE WILL BEGIN TO BUILD INTO THE REGION BY SUNDAY
NIGHT AND IS THEN EXPECTED TO DOMINATE THE WEATHER MUCH OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1225 AM EDT...A COLD FRONT IS MOVING TOWARDS OUR FORECAST
AREA FOR THE OVERNIGHT HOURS. AHEAD OF THIS BOUNDARY IS A BAND OF
LIGHT TO MODERATE RAIN SHOWERS ALONG WITH A NARROW PRE FRONTAL
RAIN BAND CONTAINING HEAVY RAIN. THE LATEST 3KM HRRR SHOWS THIS
RAIN BAND NICELY AS IT MOVES EASTWARD FROM THE HUDSON VALLEY INTO
WESTERN NEW ENGLAND...AND THIS IS THE AREA MOST LIKELY TO SEE THE
HEAVIEST RAIN DURING THE REMAINDER OF THE OVERNIGHT HOURS. WE WILL
MENTION WIDESPREAD MODERATE RAIN SHOWERS FOR THE ENTIRE
REGION...ESP CONSIDERING HOW OUR PWATS HAVE RISEN TO 1.37 INCHES
ON THE 00Z KALY SOUNDING. MOST AREAS LOOK TO SEE A HALF INCH TO
ONE INCH OF RAIN...WITH LOCALLY HIGHER AMOUNTS OVER THE HIGH
TERRAIN OF WESTERN NEW ENGLAND. WITH LIMITED INSTABILITY AND NO
LTG STRIKES OVER THE LAST 6 HOURS...HAVE REMOVED MENTION OF
THUNDER FROM THE FORECAST AS WELL. RAIN SHOWERS LOOK TO END FROM
WEST TO EAST LATER TONIGHT AS THE FRONT CROSSES THE REGION AND THE
WINDS TURN WEST.
FLOODING OF RIVERS AND STREAMS IS NOT EXPECTED AT THIS TIME...HOWEVER
WITHIN BANK RISES OF SEVERAL FEET ARE POSSIBLE ON MAJOR RIVERS.
WHAT IS MORE LIKELY IS PONDING OF WATER AND FLOODING OF POOR
DRAINAGE AND LOW LYING AREAS...MAINLY ACROSS WESTERN NEW ENGLAND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
TROUGH AXIS WILL SWING THROUGH SUNDAY AS SHORT WAVE ROTATES THROUGH
BASED OF UPPER LEVEL LOW MOVING ACROSS EASTERN CANADA. PRECIPITATION
WILL TAPER OFF FROM SOUTHWEST TO NORTHEAST DURING THE MORNING HOURS.
THE PRESSURE GRADIENT WILL TIGHTEN UP ACROSS THE REGION SUNDAY AND
WESTERLY WINDS WILL BECOME BRISK USHERING IN A COLDER AIRMASS
AIRMASS. CONDITIONS WILL REALLY BEGIN TO IMPROVE LATER IN THE
AFTERNOON INTO EVENING WITH DECREASING CLOUDS AND WEAKENS WINDS AS
THE PRESSURE GRADIENT LOOSENS ACROSS THE REGION AND HEIGHTS BEGIN TO
RISE.
IT WILL GET COLD AT NIGHT WITH LOWS BOTTOMING OUT MAINLY IN THE 30S.
DESPITE THE COLD TEMPERATURES CONDITIONS WILL BE FAVORABLE FOR
WIDESPREAD FROST DEVELOPMENT AS WE MAINTAIN A NORTHWEST WIND THROUGH
THE OVERNIGHT...WEAKEN TO 5 TO 10 MPH. COLDER TEMPERATURES WILL BE
ACROSS THE HIGHER TERRAIN WHERE SOME CLOUDS COVER WILL LINGER.
RIDGING BUILDS IN AT SURFACE AND HEIGHTS WILL BE RISING ALOFT
MONDAY. HOWEVER...A STACKED LOW DEVELOPS OVER NORTHERN NEW ENGLAND
AND IT WILL MOVE LITTLE THROUGH TUESDAY. THIS WILL MAINTAIN A
NORTHWESTERLY FLOW OVER THE REGION.
DESPITE LOTS OF SUNSHINE MONDAY...THE FIRST FULL OF DAY OF FALL WILL
BE CHILLY. HIGHS ARE ONLY EXPECTED TO BE IN THE LOWER 50S TO LOWER
60S...AROUND 10 DEGREES BELOW NORMAL. IN ADDITION...WE WILL HAVE A
BRISK NORTHWESTERLY WINDS WHICH WILL MAKE IT FEEL EVEN COLDER.
CONDITIONS WILL BE MORE FAVORABLE FOR WIDESPREAD FROST MONDAY NIGHT
WITH MOSTLY CLEAR SKIES AND WINDS DIMINISHING LATE AT NIGHT. LOOKING
FOR LOWS IN THE 30S WITH THE COLDER TEMPERATURES ACROSS THE HIGHER
TERRAIN.
TEMPERATURES WILL MODERATE CLOSER TO SEASONABLE LEVELS TUESDAY...BUT
REMAIN BELOW NORMAL BY 5 TO 10 DEGREES. OUR REGION WILL BE
SANDWICHED BETWEEN THE RIDGE AXIS TO OUR WEST ACROSS THE OHIO VALLEY
AND GREAT LAKES REGION AND THE LARGE STACKED LOW WOBBLING OVER
NORTHERN NEW ENGLAND.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MUCH OF THE EXTENDED PERIOD WILL FEATURE QUIET WEATHER WITH
TEMPERATURES MODERATING ABOVE NORMAL.
AT THE START OF THE EXTENDED PERIOD...A CUTOFF UPPER LEVEL LOW OVER
ATLANTIC CANADA WILL BE DEPARTING OUT TO SEA...WHILE AN UPPER LEVEL
RIDGE WILL BE SITUATED OVER THE MIDWEST AND GREAT LAKES REGION. WITH
CLEAR SKIES AND LIGHT WINDS...TEMPS WILL BE COOL ON TUES NIGHT/WED
MORNING...WITH 30S TO LOW 40S OVER MUCH OF THE AREA. THERE MAY BE
SOME FROST ISSUES FOR THOSE AREAS WHERE THE GROWING SEASON IS STILL
ONGOING...SUCH AS THE CATSKILLS OR SOUTHERN VT.
A WEAK UPPER LEVEL DISTURBANCE WILL ATTEMPT TO MOVE AROUND THE UPPER
RIDGING OVER THE GREAT LAKES FOR WED AND THURS...AND THE MODELS SHOW
DIFFERENCES IN EXACTLY WHERE IT MOVES. THE 12Z ECMWF SHOWS THIS
FEATURE SLIDING UNDER THE RIDGE TOWARDS THE SOUTHEAST...WHILE THE
12Z GFS WEAKENS AND FLATTENS THE RIDGE ENOUGH TO MOVE THE
DISTURBANCE ACROSS THE NORTHEAST. WITH THIS FEATURE BEING RATHER
WEAK AND MOISTURE STARVED...EITHER SCENARIO WOULD KEEP OUR REGION
DRY. MAX TEMPS WILL BE IN THE UPPER 60S TO LOW 70S FOR VALLEY
AREAS...WHICH IS NEAR TO SLIGHTLY ABOVE NORMAL.
BEHIND THAT WEAK UPPER LEVEL DISTURBANCE...BOTH MODELS SHOWS STRONG
RIDGING REESTABLISHING ITSELF ALONG THE EASTERN SEABOARD FOR FRIDAY
INTO SATURDAY. UNDER PLENTY OF SUNSHINE AND CONTINUED DRY
CONDITIONS...THIS SHOULD ALLOW MAX TEMPS TO REACH INTO THE 70S
ACROSS MOST OF THE REGION...WITH MID 70S FOR THE CAPITAL REGION AND
MID HUDSON VALLEY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
FLYING CONDITIONS ARE CURRENTLY VFR OR HIGH END MVFR WITH
INCREASING CLOUDS ACROSS THE REGION. A COLD FRONT WILL CURRENTLY
MOVING ACROSS WESTERN NEW YORK.
A BAND OF STEADY RAINFALL AHEAD OF THE BOUNDARY IS PROGRESSING
ACROSS CENTRAL NY AND WILL REACH THE HUDSON VALLEY AND WESTERN NEW
ENGLAND TAF SITES LATER THIS EVENING...PROBABLY BY AROUND 01Z-02Z.
FLYING CONDITIONS WILL QUICKLY DROP TO MVFR WITHIN THE RAIN
SHOWERS...AND SOME IFR CONDITIONS ARE EXPECTED WITHIN HEAVIER
BURSTS THROUGH ABOUT 05Z-06Z OR SO. AFTERWARD...SOME LINGERING SHOWERS ARE
EXPECTED THROUGH ABOUT SUNRISE...BUT IFR CONDITIONS LOOK TO
CONTINUE DUE TO LOW CIGS.
FLYING CONDITIONS SHOULD IMPROVE BACK TO VFR ON SUNDAY MORNING AS
THE SHOWERS END...AND CIGS BEGIN TO CLEAR OUT. VFR CONDITIONS ARE
EXPECTED THROUGH THE DAY SUNDAY.
SOUTHERLY WINDS OF AROUND 10 KTS AHEAD OF THE RAINFALL WILL BECOME
WESTERLY LATER TONIGHT AS THE COLD FRONT CROSSES THE REGION. THERE
MAY BE A FEW HIGHER GUSTS...ESP WITHIN THE HEAVIER BURSTS OF
RAINFALL. ON SUNDAY...WESTERLY WINDS WILL CONTINUE TO BE AROUND 10
KTS WITHIN DAYTIME MIXING...AND A FEW HIGHER GUSTS ARE POSSIBLE AT
KALB/KPSF.
OUTLOOK...
SUN NIGHT-MON NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. PATCHY FG
LATE NIGHT/EARLY MORNING.
TUE-THU: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
WIDESPREAD PRECIPITATION TONIGHT INTO SUNDAY AS A COLD FRONT
APPROACHES AND CROSSES THE REGION. HIGH PRESSURE WILL BEGIN TO
BUILD INTO THE REGION SUNDAY NIGHT AND IS THEN EXPECTED TO
DOMINATE THE WEATHER MUCH OF NEXT WEEK.
&&
.HYDROLOGY...
WIDESPREAD PRECIPITATION TONIGHT AS A COLD FRONT APPROACHES AND
CROSSES THE REGION. PRECIPITABLE WATERS VALUES ARE EXPECTED TO
INCREASE TO AROUND 1 1/2 INCHES AHEAD OF THE FRONTAL BOUNDARY WHICH
IS ABOUT 1 1/2 STANDARD DEVIATIONS ABOVE NORMAL. RAINFALL AMOUNTS OF
1 TO 1 1/2 INCHES ARE EXPECTED WITH LOCALLY HIGHER AMOUNTS OF 2 TO
POSSIBLY 3 INCHES. FLOODING OF RIVERS AND STREAMS IS NOT EXPECTED AT
THIS TIME...HOWEVER WITHIN BANK RISES OF SEVERAL FEET ARE POSSIBLE
ON MAJOR RIVERS. WHAT IS LIKELY IS PONDING OF WATER AND FLOODING OF
POOR DRAINAGE AND LOW LYING AREAS. CAN NOT RULE OUT ISOLATED FLASH
FLOODING.
THE UPPER LOW AND TROUGH AXIS WILL MOVE ACROSS THE REGION SUNDAY.
THE STEADY PRECIPITATION WILL TAPER OFF FROM SOUTHWEST TO
NORTHEAST DURING THE MORNING HOURS. HIGH PRESSURE WILL BEGIN TO
BUILD INTO THE REGION SUNDAY NIGHT AND IS THEN EXPECTED TO
DOMINATE THE WEATHER MUCH OF NEXT WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/FRUGIS
NEAR TERM...IAA/FRUGIS/11
SHORT TERM...IAA
LONG TERM...FRUGIS
AVIATION...FRUGIS
FIRE WEATHER...IAA
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS MIAMI FL
957 AM EDT SUN SEP 22 2013
.UPDATE...
LOW LEVEL MOISTURE CONTINUES TO INCREASE THIS MORNING AS THE
SURFACE HIGH PRESSURE HAS SHIFTED TO THE EAST WITH COLD FRONT
MOVING INTO THE FLORIDA PANHANDLE. THIS PROCESS WILL EVOLVE
THROUGH THE AFTERNOON WITH FORECAST SOUNDINGS SHOWING PWAT
INCREASING FROM NEAR 1.5 INCHES TO A RANGE OF 1.7-1.85 BY LATE IN
THE DAY. LOW LEVEL CU HAS ALREADY BEGUN TO DEVELOP IN THIS
MOISTENING ENVIRONMENT AND A FEW SHRA SHOWING UP ON RADAR ACROSS
THE FAR SOUTH PENINSULA. THE LATEST HRRR RUN INDICATES SCATTERED
CONVECTION TAKING SHAPE BY 17Z AND THEN CONTINUING TO DEVELOP AS
THE CELLS MOVE TO THE NORTH-NORTHEAST THROUGH THE AFTERNOON. SO
THE CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE AT THIS TIME AND NO
MAJOR CHANGES ARE PLANNED. HOWEVER, WILL NEED TO TAKE A CLOSER
LOOK AT OVERNIGHT POPS FOR THE AFTERNOON PACKAGE AS THE 12Z MODEL
GUIDANCE BECOMES AVAILABLE BUT THE CURRENT HRRR BEGINS TO HINT AT
GULF DEVELOPMENT IN THE 01-02Z TIME FRAME AND THIS ALSO WOULD BE ON
TARGET WITH THE CURRENT FORECAST.
KOB
&&
.PREV DISCUSSION... /ISSUED 940 AM EDT SUN SEP 22 2013/
AVIATION...
VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH MUCH OF THE 24 HR
PERIOD OVER THE TAF SITES. THE LOW-LEVEL FLOW WILL STEADILY VEER
TOWARD THE SOUTHWEST THROUGH THE PERIOD. THE BEST CHANCE FOR SHOWERS
WILL BE LATER THIS AFTERNOON/EVENING ACROSS THE NORTHERN AREAS FROM
LAKE OKEECHOBEE TO SITE PBI...WHICH COULD RESULT IN PERIODS WITH SUB
VFR CONDITIONS IN AND AROUND ANY SHRA/TSTM THAT DEVELOPS.
OVERNIGHT...THE BEST CHANCE FOR SHOWERS WILL REMAIN ALONG THE GULF
COAST AS A FRONTAL BOUNDARY STALLS NORTH OF THE AREA AND PLENTY OF
MOISTURE OVERSPREADS THE REGION FROM THE SOUTH. /85
PREV DISCUSSION... /ISSUED 347 AM EDT SUN SEP 22 2013/
.WET WEATHER ON THE WAY FOR SOUTH FLORIDA THROUGH MIDDLE OF THIS WEEK...
SHORT TERM...
HIGH PRESSURE OVER THE WESTERN ATLANTIC WATERS WILL DISSIPATE
TODAY ALLOWING FOR A COLD FRONT OVER THE SOUTHEAST UNITED STATES
TO MOVE SOUTH INTO NORTH FLORIDA. THIS WILL ALLOW FOR THE STEERING
FLOW OVER SOUTH FLORIDA TO BE SOUTHERLY TODAY BRINGING IN SOME LOW
LEVEL MOISTURE TO THE AREA. SO ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE THIS AFTERNOON OVER SOUTH FLORIDA
WITH THE BEST COVERAGE OVER THE NORTHERN AREAS.
THE COLD FRONT WILL CONTINUE TO SLOWLY MOVE SOUTH TONIGHT AND
SHOULD BE OVER CENTRAL FLORIDA ON MONDAY. THIS WILL SWING THE
STEERING FLOW TO A SOUTHWEST DIRECTION OVER SOUTH FLORIDA ON
MONDAY...AND ALLOW FOR DEEP TROPICAL MOISTURE TO WORK INTO THE
AREA FROM THE CARIBBEAN SEA. SO WILL KEEP THE LIKELY POPS IN PLACE
OVER SOUTH FLORIDA ON MONDAY.
THE FRONT WILL THEN STALL OUT OVER CENTRAL FLORIDA MONDAY NIGHT
INTO WEDNESDAY KEEPING THE SOUTHWEST STEERING FLOW IN PLACE OVER
THE AREA ALONG WITH THE DEEP TROPICAL MOISTURE. SO WILL CONTINUE
THE LIKELY POPS OVER SOUTH FLORIDA FOR TUESDAY AND WEDNESDAY.
THE DEEP TROPICAL MOISTURE WILL ALSO ALLOW FOR THE POSSIBILITY OF
HEAVY RAINFALL OVER SOUTH FLORIDA EARLY TO MIDDLE PART OF THIS
WEEK. MORE ON THIS IN THE HYDRO SECTION BELOW.
LONG TERM...
A STRONG HIGH PRESSURE SYSTEM IS FORECAST BY THE LONG RANGE MODELS
TO DEVELOP OVER THE MID ATLANTIC STATES AND EXTEND SOUTHWEST INTO
THE SOUTHEAST UNITED STATES. THIS HIGH WILL PUSH THE STATIONARY
FRONT OVER CENTRAL FLORIDA SOUTHWARD THROUGH SOUTH FLORIDA LATE
THIS WEEK AND INTO THE FLORIDA STRAITS NEXT WEEKEND. SO THE DEEP
TROPICAL MOISTURE OVER SOUTH FLORIDA WILL GET PUSH SOUTH INTO THE
FLORIDA STRAITS THIS WEEKEND WITH DRY AIR OVER THE SOUTHEAST
UNITED STATES WORKING INTO THE AREA. SO THE POPS LATE THIS WEEK
WILL BE IN THE SCATTERED RANGE BEFORE DROPPING DOWN TO ISOLATED
RANGE NEXT WEEKEND...EXCEPT LOW END SCATTERED FOR THE WEST COAST
METRO AREAS OF SOUTH FLORIDA.
MARINE...
THE WINDS WILL BE 10 TO 15 KNOTS THROUGH EARLY THIS WEEK AS THE
WINDS SWING FROM A SOUTHERLY DIRECTION TODAY TO A SOUTHWEST
DIRECTION BY MONDAY. THIS WILL KEEP THE SEAS IN THE ATLANTIC
WATERS AT 1 TO 3 FEET WHILE THE GULF WATERS WILL BE AT 2 FEET OR
LESS. SO BOATING CONDITIONS SHOULD BE GOOD OUTSIDE OF THE SHOWERS
AND THUNDERSTORMS OVER SOUTH FLORIDA WATERS.
HYDROLOGY...
THE LATEST MODELS ARE STILL SHOWING THE PWAT VALUES TO BE 2.2 TO
2.4 INCHES OVER SOUTH FLORIDA FOR EARLY TO MIDDLE PART OF THIS
WEEK. THIS MEANS THAT THERE IS THE POTENTIAL OF HEAVY RAINFALL
ACROSS SOUTH FLORIDA DURING THIS TIME. SO HAVE KEPT THE HEAVY
RAINFALL WORDING IN THE ZONES FOR MONDAY THROUGH WEDNESDAY. AT
THIS TIME...RAINFALL TOTALS ARE EXPECTED TO BE BETWEEN 2 TO 4
INCHES ACROSS THE AREA. HOWEVER...IF ANY TRAINING OF SHOWERS AND
THUNDERSTORMS SETS UP OVER THE AREA THEN THESE RAINFALL AMOUNTS
WILL BE MUCH HIGHER.
METRO COLLIER COUNTY HAS SEEN CLOSE TO 10 INCHES OF RAINFALL FOR
THE MONTH OF SEPTEMBER. THIS AMOUNT OF RAINFALL HAS MADE THE
GROUNDS OVER METRO COLLIER COUNTY VERY SATURATED. SO WILL
CONTINUE TO MONITOR THE LATEST MODEL RUNS ON RAINFALL AMOUNTS OVER
METRO COLLIER COUNTY THROUGH MIDDLE PART OF THIS WEEK TO SEE IF A
FLOOD WATCH WILL BE NEEDED FOR METRO COLLIER COUNTY IN LATER
FORECAST PACKAGES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 90 76 89 76 / 40 40 60 50
FORT LAUDERDALE 90 78 89 78 / 30 30 60 50
MIAMI 90 78 89 78 / 20 20 60 50
NAPLES 89 76 87 77 / 20 40 70 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
148 PM EDT SUN SEP 22 2013
.SYNOPSIS...
ISSUED AT 358 AM EDT SUN SEP 22 2013
HIGH PRESSURE BEGIN TO TAKE CONTROL OF THE WEATHER ACROSS THE
GREAT LAKES TODAY AND WILL PERSIST INTO THE UPCOMING WEEK. LAKE
EFFECT CLOUDS WILL SLOWLY BREAK UP TODAY WITH ALL AREAS BECOMING
MOSTLY CLEAR BY TONIGHT. HIGH TEMPERATURES WILL BE COOL AGAIN TODAY
AND REMAIN IN THE 60S. LOWS TONIGHT WILL DROP INTO THE UPPER 30S
AND LOWER 40S.
&&
.UPDATE...
ISSUED AT 120 PM EDT SUN SEP 22 2013
HAVE MADE SOME RELATIVELY MINOR UPDATES AT MIDDAY. UPSTREAM CLOUD
COVER WAS ALREADY SPREADING INTO FAR SOUTHERN LOWER MICHIGAN AND
SPILLING OVER INTO NW INDIANA. RAPID REFRESH ABOUT THE ONLY MODEL
THAT APPEARS TO BE HANDLING THIS SCENARIO WHERE UPSTREAM MOISTURE
FLUX FROM LAKE SUPERIOR AND NRN LAKE MICHIGAN WAS REALLY HAVING A
IMPACT ON CLOUD COVER. CLOUD COVER OVER 80 PERCENT OVER WESTERN
LOWER MICHIGAN WITH CLOUDS NEAR THE BASE OF THE SUBSIDENCE INVERSION.
A 1540Z ACFT SOUNDING FROM GRR SHOWS CLOUD DEPTH QUITE LIMITED.
THE LATEST SATELLITE SHOWS SUBSIDENCE APPARENTLY ENOUGH FOR SOME
CLEARING NORTH OF BEH. FOR NOW...INCREASED CLOUD MAINLY NORTH AND
NORTHEAST AREAS...BUT HAVE CLEARING EARLY TONIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT SUN SEP 22 2013
LAKE EFFECT CLOUDS HAVE MOVED WELL INLAND THANKS TO A STRONG
TRAPPING SUBSIDENCE INVERSION AND A NNW LOW LEVEL WIND. SATELLITE
SHOWS A RATHER LARGE AREA OF STRATOCUMULUS AS FAR SOUTH AS MUNCIE
AT 07Z AND STILL EXPANDING SOUTHWARD. ONLY MODEL TO HAVE A DECENT
HANDLE ON THESE CLOUDS IS THE HRRR WITH RUC13 PLAYING CATCHUP.
DELTA T VALUES INTO THE MID TEENS OVER SOUTHERN LAKE MICHIGAN WITH
850MB TEMPS DOWN TO ABOUT +3C AND MID LAKE TEMP RUNNING AROUND
20C. LACK OF DEEP MOISTURE AND THE STRONG INVERSION SEEMS TO BE
KEEPING ANY SHOWERS FROM DEVELOPING PER REGIONAL RADAR MOSAIC.
WILL RELY ON SATELLITE AND HRRR TRENDS FOR CLOUD COVER THIS
MORNING WHILE KEEPING PCPN OUT OF FORECAST.
SHOULD SEE SUBSIDENCE AND VEERING LOW LEVEL WINDS HELP ERODE EASTERN
FLANK OF CLOUD SHIELD THIS MORNING. ALREADY SEEING A LITTLE BIT OF
THIS WITH THINNING AND A FEW BREAKS DEVELOPING ON SATELLITE OVER
SOUTH CENTRAL MI AND NE INDIANA AT 08Z. TRAJECTORIES SUGGEST CLOUDS
WILL PERSIST OVER WESTERN THIRD OF CWA THROUGH THE MORNING WITH A
LIKELY TREND TOWARD BECOMING CELLULAR WITH MORE BREAKS BY AFTERNOON.
THIS SEEMS REASONABLE GIVEN SHALLOW NATURE OF MOISTURE AND CLOUDS.
SKIES EXPECTED TO BECOME MOSTLY CLEAR TONIGHT WITH HIGH PRESSURE
MOVING OVERHEAD ALONG WITH UPPER LEVEL RIDGE.
TEMPS WILL BE COOL AGAIN TODAY WITH HIGHS ONLY REACHING THE LOW TO
MID 60S ACROSS THE AREA. LOWS TONIGHT WILL DROP INTO THE UPPER 30S
TO LOWER 40S WITH CLEAR SKIES AND LIGHT WINDS. SIDED TOWARD COOLER
GUIDANCE NUMBERS GIVEN EXPECTED RADIATIONAL COOLING.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM EDT SUN SEP 22 2013
SLOW WARMING TREND REMAINS IN STORE FOR MUCH OF THE UPCOMING WEEK AS
UPPER LEVEL RIDGING MOVES INTO THE REGION. TROUGH OVER THE PLAINS
WILL MOVE EAST WITH MAIN UPPER SUPPORT REMAINING WELL NORTH OF THE
AREA. MODELS DO SHOW AN ORPHANED TROUGH THAT MIGRATES ACROSS THE
LOWER GREAT LAKES TUES NGT/WEDS...BUT LIMITED FORCING AND MSTR WITH
THE FEATURE SHOULD KEEP AWAY ANY PRECIP.
UPPER FLOW WILL RESPOND TO DEEPENING TROUGH IN THE WESTERN STATES AS
RIDGING BUILDS ACROSS THE EASTERN PLAINS INTO THE GREAT LAKES INTO
AT LEAST FRIDAY WITH TEMPS CLIMBING TO ABOVE NORMAL LEVELS IN THE
MID 70S. FORECAST DETAILS FOR SATURDAY AND BEYOND REMAIN MUDDLED AS
DEEP TROUGH EJECTS TOWARDS THE REGION WITH MODELS CONTINUING TO VARY
ON TIMING/STRENGTH/IMPACT TO THE AREA. ALL MED RANGE MODELS LIFT
BULK OF THE ENERGY NE INTO THE UPPER PLAINS/NORTHERN GREAT LAKES
WITH SOUTHERN EXTENT OF THE ENERGY RATHER VARIABLE. GFS/GEFS REMAIN
MOST AGGRESSIVE WITH TROUGH SWEEPING ACROSS SAT NGT INTO SUNDAY WITH
SHOWERS/STORMS...ALTHOUGH PROBS FOR PRECIP WITH GEFS STILL 60% OR
LESS. 12Z RUN OF ECMWF HAD A RATHER DRAMATIC SHIFT WITH ENERGY
SHIFTING NORTH AND THEN WAVE DROPPING BACK INTO THE WESTERN GREAT
LAKES AS A CUT OFF UPPER LOW. 00Z SOLUTION HAS BACKED OFF FROM THIS
AND SIMPLY FLATTENS THE RIDGE ACROSS THE REGION WITH NO PRECIP.
CONFIDENCE LOW DURING THIS PERIOD...WARRANTING CONTINUED BUCKING OF
TRENDS TO ADD POPS BY CR ALLBLEND WHICH IS HEAVILY BIASED TOWARDS
THE GFS SOLUTIONS...THE WETTEST SOLUTION AS NOTED ABOVE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 120 PM EDT SUN SEP 22 2013
UPSTREAM CLOUD COVER WAS ALREADY SPREADING INTO FAR SOUTHERN
LOWER MICHIGAN AND SPILLING OVER INTO NRN INDIANA WHERE SBN WAS
BKN 037. RAPID REFRESH ABOUT THE ONLY MODEL THAT APPEARS TO BE
HANDLING THIS SCENARIO WHERE UPSTREAM MOISTURE FLUX FROM LAKE
SUPERIOR AND NRN LAKE MICHIGAN WAS REALLY HAVING A IMPACT ON CLOUD
COVER. CLOUD COVER OVER 80 PERCENT OVER WESTERN LOWER MICHIGAN
WITH CLOUDS NEAR THE BASE OF THE SUBSIDENCE INVERSION. A 1540Z
ACFT SOUNDING FROM GRR SHOWS CLOUD DEPTH QUITE LIMITED. THE LATEST
SATELLITE SHOWS SUBSIDENCE APPARENTLY ENOUGH FOR SOME CLEARING
NORTH OF BEH. FOR NOW...INCREASED CLOUD COVER AT SBN...BUT KEPT
CONDITIONS VFR.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...SKIPPER
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...SKIPPER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
650 AM EDT SUN SEP 22 2013
.SYNOPSIS...
ISSUED AT 358 AM EDT SUN SEP 22 2013
HIGH PRESSURE BEGIN TO TAKE CONTROL OF THE WEATHER ACROSS THE
GREAT LAKES TODAY AND WILL PERSIST INTO THE UPCOMING WEEK. LAKE
EFFECT CLOUDS WILL SLOWLY BREAK UP TODAY WITH ALL AREAS BECOMING
MOSTLY CLEAR BY TONIGHT. HIGH TEMPERATURES WILL BE COOL AGAIN TODAY
AND REMAIN IN THE 60S. LOWS TONIGHT WILL DROP INTO THE UPPER 30S
AND LOWER 40S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT SUN SEP 22 2013
LAKE EFFECT CLOUDS HAVE MOVED WELL INLAND THANKS TO A STRONG
TRAPPING SUBSIDENCE INVERSION AND A NNW LOW LEVEL WIND. SATELLITE
SHOWS A RATHER LARGE AREA OF STRATOCUMULUS AS FAR SOUTH AS MUNCIE
AT 07Z AND STILL EXPANDING SOUTHWARD. ONLY MODEL TO HAVE A DECENT
HANDLE ON THESE CLOUDS IS THE HRRR WITH RUC13 PLAYING CATCHUP.
DELTA T VALUES INTO THE MID TEENS OVER SOUTHERN LAKE MICHIGAN WITH
850MB TEMPS DOWN TO ABOUT +3C AND MID LAKE TEMP RUNNING AROUND
20C. LACK OF DEEP MOISTURE AND THE STRONG INVERSION SEEMS TO BE
KEEPING ANY SHOWERS FROM DEVELOPING PER REGIONAL RADAR MOSAIC.
WILL RELY ON SATELLITE AND HRRR TRENDS FOR CLOUD COVER THIS
MORNING WHILE KEEPING PCPN OUT OF FORECAST.
SHOULD SEE SUBSIDENCE AND VEERING LOW LEVEL WINDS HELP ERODE EASTERN
FLANK OF CLOUD SHIELD THIS MORNING. ALREADY SEEING A LITTLE BIT OF
THIS WITH THINNING AND A FEW BREAKS DEVELOPING ON SATELLITE OVER
SOUTH CENTRAL MI AND NE INDIANA AT 08Z. TRAJECTORIES SUGGEST CLOUDS
WILL PERSIST OVER WESTERN THIRD OF CWA THROUGH THE MORNING WITH A
LIKELY TREND TOWARD BECOMING CELLULAR WITH MORE BREAKS BY AFTERNOON.
THIS SEEMS REASONABLE GIVEN SHALLOW NATURE OF MOISTURE AND CLOUDS.
SKIES EXPECTED TO BECOME MOSTLY CLEAR TONIGHT WITH HIGH PRESSURE
MOVING OVERHEAD ALONG WITH UPPER LEVEL RIDGE.
TEMPS WILL BE COOL AGAIN TODAY WITH HIGHS ONLY REACHING THE LOW TO
MID 60S ACROSS THE AREA. LOWS TONIGHT WILL DROP INTO THE UPPER 30S
TO LOWER 40S WITH CLEAR SKIES AND LIGHT WINDS. SIDED TOWARD COOLER
GUIDANCE NUMBERS GIVEN EXPECTED RADIATIONAL COOLING.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM EDT SUN SEP 22 2013
SLOW WARMING TREND REMAINS IN STORE FOR MUCH OF THE UPCOMING WEEK AS
UPPER LEVEL RIDGING MOVES INTO THE REGION. TROUGH OVER THE PLAINS
WILL MOVE EAST WITH MAIN UPPER SUPPORT REMAINING WELL NORTH OF THE
AREA. MODELS DO SHOW AN ORPHANED TROUGH THAT MIGRATES ACROSS THE
LOWER GREAT LAKES TUES NGT/WEDS...BUT LIMITED FORCING AND MSTR WITH
THE FEATURE SHOULD KEEP AWAY ANY PRECIP.
UPPER FLOW WILL RESPOND TO DEEPENING TROUGH IN THE WESTERN STATES AS
RIDGING BUILDS ACROSS THE EASTERN PLAINS INTO THE GREAT LAKES INTO
AT LEAST FRIDAY WITH TEMPS CLIMBING TO ABOVE NORMAL LEVELS IN THE
MID 70S. FORECAST DETAILS FOR SATURDAY AND BEYOND REMAIN MUDDLED AS
DEEP TROUGH EJECTS TOWARDS THE REGION WITH MODELS CONTINUING TO VARY
ON TIMING/STRENGTH/IMPACT TO THE AREA. ALL MED RANGE MODELS LIFT
BULK OF THE ENERGY NE INTO THE UPPER PLAINS/NORTHERN GREAT LAKES
WITH SOUTHERN EXTENT OF THE ENERGY RATHER VARIABLE. GFS/GEFS REMAIN
MOST AGGRESSIVE WITH TROUGH SWEEPING ACROSS SAT NGT INTO SUNDAY WITH
SHOWERS/STORMS...ALTHOUGH PROBS FOR PRECIP WITH GEFS STILL 60% OR
LESS. 12Z RUN OF ECMWF HAD A RATHER DRAMATIC SHIFT WITH ENERGY
SHIFTING NORTH AND THEN WAVE DROPPING BACK INTO THE WESTERN GREAT
LAKES AS A CUT OFF UPPER LOW. 00Z SOLUTION HAS BACKED OFF FROM THIS
AND SIMPLY FLATTENS THE RIDGE ACROSS THE REGION WITH NO PRECIP.
CONFIDENCE LOW DURING THIS PERIOD...WARRANTING CONTINUED BUCKING OF
TRENDS TO ADD POPS BY CR ALLBLEND WHICH IS HEAVILY BIASED TOWARDS
THE GFS SOLUTIONS...THE WETTEST SOLUTION AS NOTED ABOVE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 650 AM EDT SUN SEP 22 2013
CLOUDS HAVE BEGUN TO DISSIPATE IN LAST FEW HOURS AND EXPECT THIS
TREND TO CONTINUE AS SUBSIDENCE IS FINALLY TAKING CONTROL WITH
HIGH PRESSURE MOVING INTO AREA. KSBN MAY SEE AN OCCASIONAL BKN CIG
BUT WILL BE VFR IF IT DOES OCCUR. WINDS GENERALLY UNDER 10 KNOTS
THROUGH THE PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
404 AM EDT SUN SEP 22 2013
.SYNOPSIS...
ISSUED AT 358 AM EDT SUN SEP 22 2013
HIGH PRESSURE BEGIN TO TAKE CONTROL OF THE WEATHER ACROSS THE
GREAT LAKES TODAY AND WILL PERSIST INTO THE UPCOMING WEEK. LAKE
EFFECT CLOUDS WILL SLOWLY BREAK UP TODAY WITH ALL AREAS BECOMING
MOSTLY CLEAR BY TONIGHT. HIGH TEMPERATURES WILL BE COOL AGAIN TODAY
AND REMAIN IN THE 60S. LOWS TONIGHT WILL DROP INTO THE UPPER 30S
AND LOWER 40S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT SUN SEP 22 2013
LAKE EFFECT CLOUDS HAVE MOVED WELL INLAND THANKS TO A STRONG
TRAPPING SUBSIDENCE INVERSION AND A NNW LOW LEVEL WIND. SATELLITE
SHOWS A RATHER LARGE AREA OF STRATOCUMULUS AS FAR SOUTH AS MUNCIE
AT 07Z AND STILL EXPANDING SOUTHWARD. ONLY MODEL TO HAVE A DECENT
HANDLE ON THESE CLOUDS IS THE HRRR WITH RUC13 PLAYING CATCHUP.
DELTA T VALUES INTO THE MID TEENS OVER SOUTHERN LAKE MICHIGAN WITH
850MB TEMPS DOWN TO ABOUT +3C AND MID LAKE TEMP RUNNING AROUND
20C. LACK OF DEEP MOISTURE AND THE STRONG INVERSION SEEMS TO BE
KEEPING ANY SHOWERS FROM DEVELOPING PER REGIONAL RADAR MOSAIC.
WILL RELY ON SATELLITE AND HRRR TRENDS FOR CLOUD COVER THIS
MORNING WHILE KEEPING PCPN OUT OF FORECAST.
SHOULD SEE SUBSIDENCE AND VEERING LOW LEVEL WINDS HELP ERODE EASTERN
FLANK OF CLOUD SHIELD THIS MORNING. ALREADY SEEING A LITTLE BIT OF
THIS WITH THINNING AND A FEW BREAKS DEVELOPING ON SATELLITE OVER
SOUTH CENTRAL MI AND NE INDIANA AT 08Z. TRAJECTORIES SUGGEST CLOUDS
WILL PERSIST OVER WESTERN THIRD OF CWA THROUGH THE MORNING WITH A
LIKELY TREND TOWARD BECOMING CELLULAR WITH MORE BREAKS BY AFTERNOON.
THIS SEEMS REASONABLE GIVEN SHALLOW NATURE OF MOISTURE AND CLOUDS.
SKIES EXPECTED TO BECOME MOSTLY CLEAR TONIGHT WITH HIGH PRESSURE
MOVING OVERHEAD ALONG WITH UPPER LEVEL RIDGE.
TEMPS WILL BE COOL AGAIN TODAY WITH HIGHS ONLY REACHING THE LOW TO
MID 60S ACROSS THE AREA. LOWS TONIGHT WILL DROP INTO THE UPPER 30S
TO LOWER 40S WITH CLEAR SKIES AND LIGHT WINDS. SIDED TOWARD COOLER
GUIDANCE NUMBERS GIVEN EXPECTED RADIATIONAL COOLING.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM EDT SUN SEP 22 2013
SLOW WARMING TREND REMAINS IN STORE FOR MUCH OF THE UPCOMING WEEK AS
UPPER LEVEL RIDGING MOVES INTO THE REGION. TROUGH OVER THE PLAINS
WILL MOVE EAST WITH MAIN UPPER SUPPORT REMAINING WELL NORTH OF THE
AREA. MODELS DO SHOW AN ORPHANED TROUGH THAT MIGRATES ACROSS THE
LOWER GREAT LAKES TUES NGT/WEDS...BUT LIMITED FORCING AND MSTR WITH
THE FEATURE SHOULD KEEP AWAY ANY PRECIP.
UPPER FLOW WILL RESPOND TO DEEPENING TROUGH IN THE WESTERN STATES AS
RIDGING BUILDS ACROSS THE EASTERN PLAINS INTO THE GREAT LAKES INTO
AT LEAST FRIDAY WITH TEMPS CLIMBING TO ABOVE NORMAL LEVELS IN THE
MID 70S. FORECAST DETAILS FOR SATURDAY AND BEYOND REMAIN MUDDLED AS
DEEP TROUGH EJECTS TOWARDS THE REGION WITH MODELS CONTINUING TO VARY
ON TIMING/STRENGTH/IMPACT TO THE AREA. ALL MED RANGE MODELS LIFT
BULK OF THE ENERGY NE INTO THE UPPER PLAINS/NORTHERN GREAT LAKES
WITH SOUTHERN EXTENT OF THE ENERGY RATHER VARIABLE. GFS/GEFS REMAIN
MOST AGGRESSIVE WITH TROUGH SWEEPING ACROSS SAT NGT INTO SUNDAY WITH
SHOWERS/STORMS...ALTHOUGH PROBS FOR PRECIP WITH GEFS STILL 60% OR
LESS. 12Z RUN OF ECMWF HAD A RATHER DRAMATIC SHIFT WITH ENERGY
SHIFTING NORTH AND THEN WAVE DROPPING BACK INTO THE WESTERN GREAT
LAKES AS A CUT OFF UPPER LOW. 00Z SOLUTION HAS BACKED OFF FROM THIS
AND SIMPLY FLATTENS THE RIDGE ACROSS THE REGION WITH NO PRECIP.
CONFIDENCE LOW DURING THIS PERIOD...WARRANTING CONTINUED BUCKING OF
TRENDS TO ADD POPS BY CR ALLBLEND WHICH IS HEAVILY BIASED TOWARDS
THE GFS SOLUTIONS...THE WETTEST SOLUTION AS NOTED ABOVE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 148 AM EDT SUN SEP 22 2013
SATELLITE SHOWS LAKE CLOUDS BEING PUSHED SOUTHEAST AND HAVE
REACHED KFWA THIS HOUR. SHALLOW MOISTURE OFF LAKES BEING TRAPPED
BELOW STRONG SUBSIDENCE INVERSION AND ADVECTING SOUTH.
TRAJECTORIES AND MODEL SOUNDINGS SUGGEST THESE CLOUDS WILL LIKELY
CONTINUE THROUGH THE NIGHT AND EXPAND FURTHER SOUTHWARD AS
WELL...ESSENTIALLY LOCKING IN ACROSS MUCH OF THE AREA. OBS
INDICATE MOST CIGS IN THE VFR RANGE WITH KSBN COMING IN AT 35HFT.
ONLY HIRES GUIDANCE TO REALLY CAPTURE THESE CLOUDS SEEMS TO BE THE
HRRR WHICH HOLDS THEM IN AT KFWA THROUGH DAYBREAK BEFORE ALLOWING
SUBSIDENCE AND LOW LEVEL VEERING WINDS TO BREAK UP EASTERN FLANK
OF CLOUDS. KSBN TO LIKELY SEE AT LEAST BROKEN VFR CLOUDS THROUGH
MID TO LATE MORNING UNTIL NORTHEAST FLOW AND SUBSIDENCE FINALLY
WIN OUT. REGARDLESS...VFR CONDITIONS EXPECTED WITH LIGHT WINDS
BECOMING NORTH TO NORTHEAST AT 4 TO 9 KNOTS SUNDAY AND BECOMING
LIGHT AND VARIABLE AGAIN SUNDAY NIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
152 AM EDT SUN SEP 22 2013
.SYNOPSIS...
ISSUED AT 150 AM EDT SUN SEP 22 2013
HIGH PRESSURE WAS TAKING CONTROL ACROSS THE GREAT LAKES AND WILL
PERSIST THROUGH MUCH OF THE UPCOMING WEEK. LAKE EFFECT CLOUDS WILL
SLOWLY BREAK UP ON SUNDAY WITH ALL AREAS BECOMING MOSTLY CLEAR BY
SUNDAY NIGHT. HIGH TEMPERATURES WILL BE COOL AGAIN TODAY AND
REMAIN IN THE 60S. LOWS TONIGHT WILL DROP INTO THE LOWER AND MID
40S.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 354 PM EDT SAT SEP 21 2013
BROKEN STRATOCU DECK IS CONTINUING TO EXPAND ACROSS THE AREA AS COLD
AIR ADVECTION CONTINUES. THE COLDEST PORTION OF THIS AIRMASS WILL
ADVECT OVERHEAD TONIGHT WHICH WILL ALLOW TEMPERATURES TO DROP INTO
THE MID 40S. THE EXCEPTION WILL BE IN WESTERN AREAS WHERE LAKE
EFFECT CLOUD COVER WILL KEEP TEMPERATURES IN THE UPPER 40S. WENT
WITH A BLEND OF THE BCSREF AND BCEURO FOR OVERNIGHT LOWS AS THEY
WERE BOTH ON THE WARMER SIDE OF GUIDANCE. HAVE ELECTED FOR OVERNIGHT
LOWS A FEW DEGREES HIGHER DUE TO CONCERN OF SCATTERED CLOUDCOVER
PERSISTING ACROSS THE AREA TONIGHT AS WELL AS SLIGHTLY HIGHER
FORECAST DEWPOINTS. STRATOCU DECK ACROSS WISCONSIN HAS BEEN VERY
PERSISTENT TODAY AND BOTH THE RAP AND HRRR SHOW LITTLE DISSIPATION
AS IT ADVECTS OUR WAY OVERNIGHT. ON THE OTHER HAND...THE LAST FEW
FRAMES OF VISIBLE SATELLITE MAY BE HINTING AT SOME DRY AIR
ENTRAINMENT ON THE WESTERN EDGE OF THIS DECK. RAP/HRRR/NAM ARE ALL
INDICATING POTENTIAL FOR LAKE EFFECT RAIN SHOWERS AFTER MIDNIGHT AS
A SHORTWAVE DROPS THROUGH MICHIGAN...BUT HAVE KEPT FORECAST DRY
GIVEN LOWERING/STRENGTHENING INVERSION...DRY AIR ABOVE 850 MB...AND
SHALLOW FORECAST CLOUD DEPTH.
SUNDAY WILL BE COOL AND MOSTLY SUNNY AS HIGH PRESSURE SLIDES ACROSS
THE GREAT LAKES AND CYCLONIC FLOW ALOFT COMES TO AN END. CU RULE
VALUES IN THE WEST INDICATE THE POTENTIAL FOR SOME LAKE EFFECT CLOUD
COVER FOR THE FIRST PORTION OF THE DAY...BUT EVEN THIS WILL COME TO
AN END BY MID DAY ONCE WARM AIR ADVECTION ARRIVES.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 354 PM EDT SAT SEP 21 2013
UPR LEVEL RIDGE OVER THE PLAINS THIS AFTN WILL MOVE EAST TO THE WRN
GRTLKS SUNDAY NIGHT. THIS RIDGE SHOULD BECOME NRLY STNRY OVER THE
GRTLKS MON-TUE AS A DEEP CUT-OFF LOW FORMS OVER SERN CANADA. STRONG
SHRTWV MOVG ONTO THE WEST COAST THIS AFTN IS EXPECTED TO MOVE EAST
TO THE MS VALLEY TUE. COMBINATION OF ENCOUNTER WITH STALLED RIDGE
AND SHEARING ASSOCIATED WITH ANOTHER STRONG SHRTWV MOVG INTO THE
MEAN WRN TROF WILL WEAKEN THE LEAD SHRTWV AS IT APPROACHES OUR AREA.
SHOULD BE SOME INCREASE IN MOISTURE/CLOUDINESS AS THIS SYSTEM MOVES
THROUGH THE AREA TUE NGT/WED BUT AIRMASS EXPECTED TO REMAIN STABLE
WITH RATHER WARM MID/UPR LEVELS SO KEPT FCST DRY THROUGH THIS
TIMEFRAME.
RIDGE SHOULD REBUILD OVER THE AREA THU-FRI AS THE NEXT STRONG SHRTWV
CURRENTLY LOCATED OVER THE GULF OF ALASKA MOVES ACROSS THE ROCKIES.
12Z MEDIUM RANGE MODELS CONT TO HAVE CONSIDERABLE DIFFERENCE ON
TIMING/EVOLUTION OF THE TROF BY SATURDAY WITH ECMWF SHEARING SYSTEM
NE ACROSS THE NRN PLAINS/UPR GRTLKS INTO MANITOBA/ONTARIO WHILE
GFS/GEFS MAINTAIN A STRONGER UPR TROF/SFC CDFNT MOVG EAST INTO THE
MID/UPR MS VALLEY. BOTH MODELS HAVE TRENDED TOWARD A MORE PERSISTENT
RIDGE NEXT WEEKEND ACROSS THE GRTLKS OVER THE PAST 24HRS SO PREFER
ECMWF FARTHER WEST SOLUTION IN THIS REGARD AND THUS KEPT FCST FOR
SAT DRY FOR NOW.
TEMPS SHOULD BE A BIT BLO NORMAL AT THE START OF THE PERIOD WITH
LOWS IN THE L-M40S AND HIGHS IN THE M-U60S MONDAY. A SLOW WARMING
TREND EXPECTED THROUGH THE WEEK AS UPR RIDGE BUILDS INTO THE AREA
WITH ABOVE NORMAL TEMPS MID-LATE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 148 AM EDT SUN SEP 22 2013
SATELLITE SHOWS LAKE CLOUDS BEING PUSHED SOUTHEAST AND HAVE
REACHED KFWA THIS HOUR. SHALLOW MOISTURE OFF LAKES BEING TRAPPED
BELOW STRONG SUBSIDENCE INVERSION AND ADVECTING SOUTH.
TRAJECTORIES AND MODEL SOUNDINGS SUGGEST THESE CLOUDS WILL LIKELY
CONTINUE THROUGH THE NIGHT AND EXPAND FURTHER SOUTHWARD AS
WELL...ESSENTIALLY LOCKING IN ACROSS MUCH OF THE AREA. OBS
INDICATE MOST CIGS IN THE VFR RANGE WITH KSBN COMING IN AT 35HFT.
ONLY HIRES GUIDANCE TO REALLY CAPTURE THESE CLOUDS SEEMS TO BE THE
HRRR WHICH HOLDS THEM IN AT KFWA THROUGH DAYBREAK BEFORE ALLOWING
SUBSIDENCE AND LOW LEVEL VEERING WINDS TO BREAK UP EASTERN FLANK
OF CLOUDS. KSBN TO LIKELY SEE AT LEAST BROKEN VFR CLOUDS THROUGH
MID TO LATE MORNING UNTIL NORTHEAST FLOW AND SUBSIDENCE FINALLY
WIN OUT. REGARDLESS...VFR CONDITIONS EXPECTED WITH LIGHT WINDS
BECOMING NORTH TO NORTHEAST AT 4 TO 9 KNOTS SUNDAY AND BECOMING
LIGHT AND VARIABLE AGAIN SUNDAY NIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT UNTIL 3 AM CDT EARLY THIS MORNING FOR
INZ003.
MI...BEACH HAZARDS STATEMENT UNTIL 4 AM EDT EARLY THIS MORNING FOR
MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
LMZ043-046.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...BENTLEY
LONG TERM...JT
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
711 PM MDT MON SEP 23 2013
.UPDATE...
ISSUED AT 707 PM MDT MON SEP 23 2013
UPDATED TO EXPIRE THE WIND ADVISORY AND HIGH WIND WARNING ACROSS
THE FORECAST AREA. THE WINDS SHOULD CONTINUE TO DIMINISH ACROSS
THE REGION OVERNIGHT AND THROUGH THE DAY ON TUESDAY AS THE LOW
PRESSURE AREA MOVES EAST AND IS REPLACED BY HIGH PRESSURE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 239 PM MDT MON SEP 23 2013
UPPER FLOW WILL BE NORTHWEST TONIGHT AND TUESDAY AS THE UPPER LOW
MOVES NORTHEAST INTO IOWA. SURFACE HIGH PRESSURE WILL MOVE INTO THE
CENTRAL PLAINS.
AS THE UPPER LOW LIFTS OUTS THIS EVENING ANY REMAINING SHOWERS WILL
EXIT THE FA. SUBSIDENCE WILL FOLLOW AND CONTINUE THROUGH TUESDAY.
OTHER THAN SOME SLIGHT CHANCE POPS EARLY THIS EVENING, POPS WILL BE
NIL FOR THE REMAINDER OF THIS PART OF THE FORECAST.
HRRR AND RUC MODELS INDICATE STRONG WINDS WILL CONTINUE UNTIL AROUND
01Z. PLAN TO CONTINUE HIGH WIND WARNING AND WIND ADVISORY UNTIL 01Z
TUESDAY. GUSTY NORTHWEST WIND WILL DECREASE AROUND SUNSET.
MIN TEMPERATURES WILL BE COOL TONIGHT WITH READINGS RANGING FROM THE
MID 40S IN EASTERN COLORADO TO AROUND 50 IN THE EASTERN FA. MAX
TEMPERATURES TUESDAY WILL WARM INTO THE MID/UPPER 70S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 239 PM MDT MON SEP 23 2013
A BRIEF PERIOD OF SHORTWAVE RIDGING WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY...LEADING TO DRY WEATHER. AS STATED ABOVE...BRIEF IS THE
KEY WORD AS THE NEXT LARGE TROUGH OF LOW PRESSURE DEVELOPS OVER THE
WESTERN UNITED STATES AND HEADS EAST. AHEAD OF THE UPPER LEVEL
TROUGH...A WARMING TREND IS FORECAST UNDER A WARM AIR ADVECTION
REGIME OF SOUTH WINDS. HIGH TEMPERATURES ARE EXPECTED TO CLIMB INTO
THE MID 80S ON WEDNESDAY AND MID TO UPPER 80S...POSSIBLY NEAR
90...ON THURSDAY. ALSO...PRESSURE GRADIENTS ARE EXPECTED TO TIGHTEN
ON WEDNESDAY WHICH WILL RESULT IN A PERIOD OF BREEZY TO POSSIBLY
WINDY CONDITIONS DURING THE DAY AND EARLY EVENING. A LEE TROUGH IS
INDICATED BY MODELS TO MOVE IN ON THURSDAY...BRINGING A WIND SHIFT
AND COOLER TEMPERATURES TO NORTHEAST COLORADO. AHEAD OF THE LEE
TROUGH...IT IS POSSIBLE A FEW SHOWERS...POSSIBLY A
THUNDERSTORM...COULD DEVELOP FOR THURSDAY AFTERNOON AND THURSDAY
NIGHT.
AS THE UPPER LEVEL TROUGH EJECTS ACROSS THE NORTHERN PLAINS...A COLD
FRONT WILL BE FORCED DOWN ACROSS THE TRI-STATE AREA. THERE ARE SOME
LARGE TIMING DIFFERENCES BETWEEN MODELS AT THE PRESENT
TIME...LEADING TO WIND AND TEMPERATURE FIELDS LACKING IN AGREEMENT
AS WELL. THEREFORE...DID NOT STRAY TOO MUCH FROM THE MIDDLE GROUND
OF THE MODELS FOR THIS NEXT SYSTEM. THE MIDDLE GROUND PLACES FRONTAL
PASSAGE EARLY IN THE DAY ON FRIDAY. EITHER WAY...THERE WILL BE
A GOOD CHANCE FOR SHOWERS AND POSSIBLY A FEW RUMBLES OF THUNDER FOR
FRIDAY NIGHT BEHIND THE FRONT. A FEW ISOLATED SHOWERS AND STORMS ARE
POSSIBLE AHEAD OF THE FRONT BUT THE MAJORITY OF THE ACTIVITY SHOULD
STAY TO THE SOUTHEAST WHERE INSTABILITY IS PROJECTED TO BE HIGHER.
IN ADDITION...TEMPERATURES COOL DRAMATICALLY AGAIN BEHIND THE COLD
FRONT. HIGH TEMPERATURES ON FRIDAY WILL RANGE FROM THE LOW 60S TO
THE UPPER 70S FROM NORTHWEST TO SOUTHEAST. COOL...NEAR TO JUST BELOW
NORMAL TEMPERATURES WILL CONTINUE INTO THE WEEKEND AS SURFACE HIGH
PRESSURE BUILDS IN FROM THE WEST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 611 PM MDT MON SEP 23 2013
VFR CONDITIONS ARE EXPECTED AT GLD AND MCK THROUGH THE TAF PERIOD.
PARTLY CLOUDY SKIES WILL BECOME CLEAR BY 03Z AT GLD AND 07Z AT MCK.
GUSTY NORTHWEST WINDS WILL DECREASE AFTER SUNSET AND BECOME LIGHT
BY 11Z. LIGHT WINDS AND SUNNY SKIES WILL CONTINUE THROUGH THE DAY
ON TUESDAY AS HIGH PRESSURE MOVES INTO THE REGION.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...LOCKHART
SHORT TERM...FS
LONG TERM...RRH
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS GOODLAND KS
616 PM MDT MON SEP 23 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 239 PM MDT MON SEP 23 2013
UPPER FLOW WILL BE NORTHWEST TONIGHT AND TUESDAY AS THE UPPER LOW
MOVES NORTHEAST INTO IOWA. SURFACE HIGH PRESSURE WILL MOVE INTO THE
CENTRAL PLAINS.
AS THE UPPER LOW LIFTS OUTS THIS EVENING ANY REMAINING SHOWERS WILL
EXIT THE FA. SUBSIDENCE WILL FOLLOW AND CONTINUE THROUGH TUESDAY.
OTHER THAN SOME SLIGHT CHANCE POPS EARLY THIS EVENING, POPS WILL BE
NIL FOR THE REMAINDER OF THIS PART OF THE FORECAST.
HRRR AND RUC MODELS INDICATE STRONG WINDS WILL CONTINUE UNTIL AROUND
01Z. PLAN TO CONTINUE HIGH WIND WARNING AND WIND ADVISORY UNTIL 01Z
TUESDAY. GUSTY NORTHWEST WIND WILL DECREASE AROUND SUNSET.
MIN TEMPERATURES WILL BE COOL TONIGHT WITH READINGS RANGING FROM THE
MID 40S IN EASTERN COLORADO TO AROUND 50 IN THE EASTERN FA. MAX
TEMPERATURES TUESDAY WILL WARM INTO THE MID/UPPER 70S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 239 PM MDT MON SEP 23 2013
A BRIEF PERIOD OF SHORTWAVE RIDGING WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY...LEADING TO DRY WEATHER. AS STATED ABOVE...BRIEF IS THE
KEY WORD AS THE NEXT LARGE TROUGH OF LOW PRESSURE DEVELOPS OVER THE
WESTERN UNITED STATES AND HEADS EAST. AHEAD OF THE UPPER LEVEL
TROUGH...A WARMING TREND IS FORECAST UNDER A WARM AIR ADVECTION
REGIME OF SOUTH WINDS. HIGH TEMPERATURES ARE EXPECTED TO CLIMB INTO
THE MID 80S ON WEDNESDAY AND MID TO UPPER 80S...POSSIBLY NEAR
90...ON THURSDAY. ALSO...PRESSURE GRADIENTS ARE EXPECTED TO TIGHTEN
ON WEDNESDAY WHICH WILL RESULT IN A PERIOD OF BREEZY TO POSSIBLY
WINDY CONDITIONS DURING THE DAY AND EARLY EVENING. A LEE TROUGH IS
INDICATED BY MODELS TO MOVE IN ON THURSDAY...BRINGING A WIND SHIFT
AND COOLER TEMPERATURES TO NORTHEAST COLORADO. AHEAD OF THE LEE
TROUGH...IT IS POSSIBLE A FEW SHOWERS...POSSIBLY A
THUNDERSTORM...COULD DEVELOP FOR THURSDAY AFTERNOON AND THURSDAY
NIGHT.
AS THE UPPER LEVEL TROUGH EJECTS ACROSS THE NORTHERN PLAINS...A COLD
FRONT WILL BE FORCED DOWN ACROSS THE TRI-STATE AREA. THERE ARE SOME
LARGE TIMING DIFFERENCES BETWEEN MODELS AT THE PRESENT
TIME...LEADING TO WIND AND TEMPERATURE FIELDS LACKING IN AGREEMENT
AS WELL. THEREFORE...DID NOT STRAY TOO MUCH FROM THE MIDDLE GROUND
OF THE MODELS FOR THIS NEXT SYSTEM. THE MIDDLE GROUND PLACES FRONTAL
PASSAGE EARLY IN THE DAY ON FRIDAY. EITHER WAY...THERE WILL BE
A GOOD CHANCE FOR SHOWERS AND POSSIBLY A FEW RUMBLES OF THUNDER FOR
FRIDAY NIGHT BEHIND THE FRONT. A FEW ISOLATED SHOWERS AND STORMS ARE
POSSIBLE AHEAD OF THE FRONT BUT THE MAJORITY OF THE ACTIVITY SHOULD
STAY TO THE SOUTHEAST WHERE INSTABILITY IS PROJECTED TO BE HIGHER.
IN ADDITION...TEMPERATURES COOL DRAMATICALLY AGAIN BEHIND THE COLD
FRONT. HIGH TEMPERATURES ON FRIDAY WILL RANGE FROM THE LOW 60S TO
THE UPPER 70S FROM NORTHWEST TO SOUTHEAST. COOL...NEAR TO JUST BELOW
NORMAL TEMPERATURES WILL CONTINUE INTO THE WEEKEND AS SURFACE HIGH
PRESSURE BUILDS IN FROM THE WEST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 611 PM MDT MON SEP 23 2013
VFR CONDITIONS ARE EXPECTED AT GLD AND MCK THROUGH THE TAF PERIOD.
PARTLY CLOUDY SKIES WILL BECOME CLEAR BY 03Z AT GLD AND 07Z AT MCK.
GUSTY NORTHWEST WINDS WILL DECREASE AFTER SUNSET AND BECOME LIGHT
BY 11Z. LIGHT WINDS AND SUNNY SKIES WILL CONTINUE THROUGH THE DAY
ON TUESDAY AS HIGH PRESSURE MOVES INTO THE REGION.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY UNTIL 7 PM MDT /8 PM CDT/ THIS EVENING FOR KSZ001-
013-014-027-028-041-042.
HIGH WIND WARNING UNTIL 7 PM MDT /8 PM CDT/ THIS EVENING FOR
KSZ013-027-028-041-042.
CO...WIND ADVISORY UNTIL 7 PM MDT THIS EVENING FOR COZ090>092.
HIGH WIND WARNING UNTIL 7 PM MDT THIS EVENING FOR COZ091-092.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...RRH
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS CARIBOU ME
159 AM EDT SUN SEP 22 2013
.SYNOPSIS...
A STRONG COLD FRONT AND UPPER LEVEL LOW WILL APPROACH THE STATE
OVERNIGHT AND MOVE THROUGH THE FORECAST AREA ON SUNDAY. THE UPPER
LOW WILL THEN LINGER EAST OF THE REGION THROUGH MIDWEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
2 AM UPDATE...ADJUSTED THE SKY COVER TO ACCOUNT FOR SOME PARTIAL
CLEARING DOWNEAST ESPECIALLY ALONG THE COAST PER THE LATEST IR
SATL IMAGERY AND THE OBS. A LARGE AREA OF RAIN W/POCKETS OF
HEAVIER RAINFALL MOVING ACROSS EASTERN NYS INTO VT AND NH AS OF
05Z SFC ANALYSIS. BACKED UP THE TIMING OF THE RAINFALL BY A FEW
HRS GIVEN THIS ANALYSIS. THE LATEST RUN OF THE HRRR AND THE NAM
DOING QUITE WELL W/THE PLACEMENT. INCREASED THE WINDS/GUSTS
OVERNIGHT INTO EARLY SUNDAY W/LLVL JET OF 50 KTS PER THE LATEST
LAPS AND NAM SOUNDINGS. TEMPERATURES ALSO NEEDED ADJUSTMENT UPWARD
PER THE LATEST OBS SHOWING READINGS IN THE LOW TO MID 60S.
PREVIOUS DISCUSSION... FORECAST CHALLENGE FOR NEAR TERM WILL BE
FRONTAL SYSTEM DUE TO ARRIVE WITH RAIN LATE TONIGHT AND SUNDAY. IN
THE MEANTIME, A SOUTHERLY FLOW HAS ADVECTED IN MARINE STRATUS
ALONG MUCH OF THE COAST WITH MAINLY SUNNY SKIES ELSEWHERE. EXPECT
CLOUDS TO INCREASE ACROSS THE REMAINDER OF THE REGION LATER THIS
EVENING INTO THE OVERNIGHT. SOME LIGHT RAIN AND PATCHY DRIZZLE
WILL BE POSSIBLE BY THE LATE EVENING INTO THE EARLY PART OF THE
OVERNIGHT WITH HEAVIER AND STEADIER RAIN ARRIVING FROM WEST TO
EAST LATE TONIGHT INTO SUNDAY MORNING.
SUNDAY WILL FEATURE WET AND BREEZY CONDITIONS. EXPECT
RAIN, MODERATE TO EVEN HEAVY AT TIMES. THE HEAVIEST RAIN WILL FALL
IN THE MORNING OVER WESTERN PORTIONS OF THE CWA AND IN THE
AFTERNOON OVER EASTERN AREAS. OVERALL, FORECAST MODELS HAVE COME
INTO BETTER AGREEMENT SO UTILIZED A BLENDED SOLUTION OF THE 12Z
GFS, GEM REG, NAM, AND RFC GRIDS FOR QPF. RAINFALL TOTALS LOOK
TO GENERALLY BE AROUND AN INCH BY LATE DAY. HOWEVER MODELS
CONTINUE TO DEPICT SOME ELEVATED INSTABILITY SO KEPT THE MENTION
OF ISOLATED THUNDER IN THE GRIDS WHICH COULD RESULT IN LOCALLY
HIGHER RAINFALL AMOUNTS OF UP TO AN INCH AND A HALF OR MORE.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
THE SURFACE LOW AND COLD FRONT WILL MOVE EAST OF THE REGION EARLY
SUNDAY NIGHT...WITH THE UPPER LOW STARTING TO CROSS THE REGION
OVERNIGHT. THE MOST EXTENSIVE SHOWERS WILL OCCUR ACROSS EASTERN
AND NORTHERN PORTIONS OF THE FORECAST AREA DURING THE EVENING IN
ADVANCE OF THE COLD FRONT. SHOWERS WILL DIMINISH IN THE WAKE OF
THE COLD FRONT ACROSS CENTRAL AND DOWNEAST AREAS. HOWEVER...SHOWERS
WITH THE UPPER LOW WILL PERSIST ACROSS NORTHERN AREAS SUNDAY
NIGHT. THE UPPER LOW WILL BEGIN TO MOVE EAST OF THE REGION MONDAY.
THE BEST CHANCES FOR SHOWERS AND MOST EXTENSIVE CLOUD COVER MONDAY
WILL OCCUR ACROSS NORTHERN AREAS...WITH GENERALLY PARTLY SUNNY
SKIES DOWNEAST. WITH A BLOCKING PATTERN ALOFT...UNCERTAINTY THEN
EXISTS REGARDING HOW QUICKLY THE UPPER LOW MOVES EAST MONDAY
NIGHT THROUGH TUESDAY NIGHT AND THE TIMING OF ANY DISTURBANCES
WHICH MIGHT ROTATE AROUND THE UPPER LOW. GENERALLY EXPECT THE
MOST EXTENSIVE CLOUD COVER AND SLIGHT CHANCE OF SHOWERS ACROSS
NORTHERN AREAS MONDAY NIGHT INTO TUESDAY. THE COLD POOL
ALOFT...WILL SUPPORT DIURNAL CLOUD DEVELOPMENT ACROSS THE
REMAINDER OF THE FORECAST AREA. SURFACE HIGH PRESSURE WILL BEGIN
TO SLOWLY BUILD EAST TUESDAY NIGHT. TEMPERATURES WILL BE AT BELOW
NORMAL LEVELS MONDAY/TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE EXTENDED PERIOD WILL BE QUIET AS A RIDGE OF HIGH PRESSURE WILL
SETTLE ACROSS THE NORTHEAST MID-LATE NEXT WEEK. AN UPPER LOW OVER
THE CANADIAN MARITIMES WILL KEEP SOME CLOUDS AROUND, MAINLY OVER
NORTHEASTERN AREAS, ON WEDNESDAY, BUT MOSTLY CLEAR SKIES WILL BE THE
RULE MOST OF THE TIME. OVERNIGHT TEMPERATURES COULD BE A LITTLE CHILLY
GIVEN LIGHT WINDS AND CLEAR SKIES; HAVE TRENDED JUST A TAD COOLER
THAN GUIDANCE, BUT LATER SHIFTS WILL NEED TO MONITOR TO DETERMINE
IF LOWS MAY NEED TO BE LOWERED MORE. DAYTIME HIGHS WILL BE
PLEASANT AND SEASONABLE, WITH MOST LOCATIONS TOPPING OUT IN THE
60S.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: FOR THE NORTHERN TERMINALS, VFR WILL DROP TO MVFR AND
EVENTUALLY IFR OVERNIGHT AS LOW CLOUDS AND RAIN MOVE IN. SUNDAY
WILL BE WET AND BREEZY WITH CONTINUING IFR CONDITIONS. FOR KBHB
AND KBGR, MVFR LOWERS TO IFR TONIGHT WITH LIFR EVEN POSSIBLE BY
SUNDAY. SOUTHERLY WINDS INCREASE TONIGHT INTO SUNDAY MORNING AHEAD
OF A COLD FRONT WITH WIND SHEAR LIKELY BEING A CONCERN TONIGHT
INTO SUNDAY. THE 00Z KCAR SOUNDING HAD A SOUTH WIND OF 43 KT AT
2500 FT AGL AND WIND SPEEDS OF 50 KTS ARE EXPECTED OVERNIGHT AT 2K
FT AGL.
SHORT TERM: MVFR/IFR CONDITIONS ARE EXPECTED ACROSS THE ENTIRE
REGION EARLY SUNDAY NIGHT. CONDITIONS WILL IMPROVE TO VFR LEVELS
DOWNEAST LATER SUNDAY NIGHT WITH OCCASIONAL MVFR CONDITIONS
PERSISTING ACROSS NORTHERN AREAS. OCCASIONAL MVFR CONDITIONS ARE
POSSIBLE ACROSS NORTHERN AREAS MONDAY INTO TUESDAY...WITH
GENERALLY VFR CONDITIONS DOWNEAST. VFR CONDITIONS ARE EXPECTED
ACROSS THE ENTIRE REGION TUESDAY NIGHT. VFR CONDITIONS ARE
EXPECTED TO CONTINUE THROUGH MID WEEK AS HIGH PRESSURE SETTLES
OVER THE REGION.
&&
.MARINE...
NEAR TERM: SEAS HAVE BEEN SLOWLY BUILDING THIS EVENING AND ARE NOW
AROUND 4 FT AT THE EASTERN MAINE SHELF. THE SEAS WILL CONTINUE
TO BUILD AND SHOULD REACH SCA LEVELS BY LATE TONIGHT AND
CONTINUE INTO SUNDAY. WINDS MAY ABATE FOR A TIME BY LATE SUNDAY
WITH SEAS STAYING UP HOWEVER.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED SUNDAY
NIGHT THROUGH MONDAY NIGHT...WITH CONDITIONS BELOW SMALL CRAFT
ADVISORY LEVELS TUESDAY/TUESDAY NIGHT. VISIBILITIES WILL BE REDUCED
IN SHOWERS EARLY SUNDAY NIGHT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
619 PM EDT SUN SEP 22 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH THIS WEEK.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
615 PM UPDATE...
INCREASED CLOUDS ACROSS NORTHERN COUNTIES OVERNIGHT. CONTINUED NW
FLOW OFF THE LAKE. HRRR ALSO ADVERTISING CLOUDS TO ERODE EXCEPT
NW. AS A RESULT...DROPPED MENTION OF FROST FOR EXTREME NE AREA
TONIGHT WITH INCREASE IN CLOUDS. ALSO DROPPED VALLEY FOG ACROSS
NORTH AND KEPT IT ACROSS SOUTHERN ONE HALF TO TWO THIRDS OF CWA.
ADJUSTED TEMP AND TD TREND.
PREVIOUS DISCUSSION FOLLOWS...NW FLOW ACRS THE GT LKS AND COOL
AIR ALOFT WL CONT TO BRING BKN- OVC STRATOCU INTO THE EVE. THIS
SHOULD GRDLY SCT OUT AS FLOW EVENTUALLY TURNS MORE NE OVRNGT.
RIDGING WL STRENGTHEN THRU MON NGT AS WELL. TEMPS MAY BE COLD
ENOUGHT TNGT AND MON NGT FOR SOME PTCHY FROST INVOF N OF FKL-
DUJ...BUT COVG SHOULD BE PTCHY ENOUGH FOR NO ADVISORIES ATTM.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
H5 RDG AXIS OVER OHVLY WILL FLATTEN TUE AS SHRTWV TROF ADVCS EWD
FROM WRN GRTLKS RGN. MSTR RETURN XPCD TO RMN LMTD...WHICH WILL IN
TURN LMT PCPN POTL WITH THE PASSAGE OF THIS WAVE.
WITH HIPRES DOMINANT ON TUE...NIL POPS WERE CONTD. POPS INCR WED
IN SRN ZONES OWING TO THEIR PROXIMAL LOCATION TO LOW-LVL MSTR AMID
WAVE PASSAGE. GUIDANCE INDICATES AT LEAST LOW PSBLTY OF LGT PCPN
DURG THIS TIME...BUT NWD EXTENT OF ANY PCPN WILL BE RESTRICTED BY
WAVE TRAJECTORY AND MSTR.
TEMPS WILL RECOVER MODESTLY TUE AND WED. MAXIMA GENLY IN THE MID
60S-LWR 70S LKLY BOTH DAYS...PSBLY WARMING INTO THE MID 70S ON WED
IF CLD CVR RMNS SPARSE. KRAMAR
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
HIGH PRES WL REMAIN ACRS THE RGN THRU SAT WITH DRY WEA EXPD. AN
APRCHG CDFNT WL INCRS SHWR CHCS BY SUN. ABV SEASONAL AVG TEMPS ARE
EXPD THRU THE PD.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
NW FLOW ACRS THE GT LKS AND COOL AIR ALOFT WL BRING BKN VFR
CU/STRATOCU TDA. CIGS SHOULD GRDLY SCT OUT TNGT WITH LOSS OF
DAYTIME HEATING AND AS FLOW TURNS NE. MAINTAINED MVFR/IFR RIVER
VLY FG LT TNGT/MON MRNG AT SELECTED PORTS...OTRW ONLY SCT DIURNAL
CU EXPD MON.
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
VFR CONDS ARE EXPD THRU THE PD UNDER HIGH PRES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
752 PM EDT MON SEP 23 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 405 PM EDT MON SEP 23 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A MID LEVEL RIDGE OVER THE
WRN GREAT LAKES. UPSTREAM...A WELL-DEFINED MID LEVEL LOW WAS LIFTING
NE THRU WRN NEBRASKA. ALTHOUGH THE SFC HIGH PRES RIDGE IS EAST OF
THE AREA...EXTENDING FROM JAMES BAY TO LAKE HURON...STUBBORN
STRATOCU REMAINS DOWNWIND OF LAKE MICHIGAN...THOUGH THERE ARE SIGNS
THAT COVERAGE IS STARTING TO SHRINK DUE TO A COMBINATION OF FALLING
INVERSION HEIGHTS (PER RAOBS TRENDS) AND DAYTIME HEATING MIXING OUT
LOW-LEVEL MOISTURE. WARMING AIR MASS IS ALSO DIMINISHING THE LAKE
COMPONENT TO CLOUD COVER. ABUNDANT SUNSHINE HAS HELPED TO RAISE
TEMPS INTO MID 60S THIS AFTN OVER THE W HALF OF UPPER MI.
ALTHOUGH A WELL-DEFINED SHORTWAVE IS OVER THE WRN PLAINS...SHORT
TERM AND THE NEXT SEVERAL DAYS WILL BE QUIET WEATHER WISE. MAIN FCST
CONCERN WILL BE CLOUD COVER. WITH STRATOCU COVERAGE NEAR LAKE
MICHIGAN SHOWING SIGNS OF SHRINKING...THERE IS HOPE THAT THE CLOUDS
WILL CONTINUE TO DISSIPATE AND NOT REDEVELOP/EXPAND TONIGHT...
ESPECIALLY SINCE INVERSION BASE TEMPS OVER NRN LAKE MICHIGAN WILL BE
A COUPLE OF C HIGHER TONIGHT THAN LAST NIGHT. HOWEVER...SINCE
TRAJECTORIES LEAD SSE BACK TO THE STRATOCU/MOISTURE FIELD OVER SRN
LWR MI/NRN OH...STRATOCU PROBABLY WON`T CLEAR OUT FOR THE ENTIRE
NIGHT. THERE MAY BE A PERIOD THIS EVENING WHEN MUCH OF THE CLOUD
COVER DISSIPATES...BUT EXPECT SOME INCREASE IN STRATOCU AGAIN
OVERNIGHT GIVEN UPSTREAM CLOUD COVER/MOISTURE AS MENTIONED AND DUE
TO LAND BREEZE CONVERGENCE DEVELOPING OVER LAKE MICHIGAN. CLOUDS
SHOULDN`T BE AS EXTENSIVE LATE TONIGHT/TUE MORNING AS EARLIER TODAY.
AS FOR TEMPS...GENERALLY FAVORED THE LOW END OF GUIDANCE WITH
PRECIPITABLE WATER 50-60PCT OF NORMAL AND WEAKER PRES
GRADIENT/LOW-LEVEL WINDS LATER TONIGHT THAN EARLY THIS MORNING. WITH
MINS DOWN INTO THE MID 30S IN THE INTERIOR...EXPECT PATCHY FROST
OVERNIGHT.
MODELS ARE IN GOOD AGREEMENT TAKING THE CURRENTLY WELL-DEFINED MID
LOW OVER NEBRASKA E INTO THE MID MISSISSIPPI VALLEY TUE AND
WEAKENING IT AS IT CUTS INTO THE MID LEVEL RIDGE. FEATURE WILL HAVE
NO AFFECT ON THE WEATHER HERE TUE AS DRY AIR LINGERS OVER THE AREA.
AS WITH TONIGHT...MAIN CONCERN TUE WILL BE STRATOCU NEAR LAKE MI.
STRATOCU DOWNWIND OF THE LAKE MAY BRIEFLY EXPAND WESTWARD FOR A
COUPLE OF HRS TUE MORNING AS DAYTIME HEATING WORKS ON LOW-LEVEL
MOISTURE...BUT THERE SHOULD BE A SOMEWHAT QUICKER EROSION OF THE
CLOUDS FROM INLAND TOWARD THE LAKE THAN TODAY. OTHER THAN THE CLOUD
ISSUE...TUE IS SHAPING UP TO BE A NICE AUTUMN DAY. IF MIXING REACHES
850MB...MAX TEMPS IN THE LOW/MID 70S WOULD BE COMMON. MIXING DEPTH
MAY NOT GET QUITE THAT HIGH...SO UPPER 60S/LWR 70S LOOK MORE LIKELY
AWAY FROM MARINE INFLUENCE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 249 PM EDT MON SEP 23 2013
WILL START THE PERIOD AT 00Z WEDNESDAY WITH THE 500MB RIDGE STILL
SET UP ACROSS E UPPER MI AND LAKE HURON/E ONTARIO. THE MAIN STORY
WILL BE THE CONTINUALLY WEAKENING TROUGH STRETCHING FROM MN THROUGH
NW TN. A HIGHLY BROKEN LINE OF SHOWERS MAY BE SET UP ACROSS MN...BUT
WITH THE WEAKENING OF THE TROUGH AND SFC HIGH WITH LIGHT NE FLOW AT
THE SFC...LITTLE MORE THAN CLOUDS ARE ANTICIPATED ACROSS UPPER MI
LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. BEHIND THE 500MB
TROUGH...THE S-CENTRAL PLAINS RIDGE WILL QUICKLY BUILD BACK ACROSS
THE UPPER GREAT LAKES WEDNESDAY THROUGH THURSDAY.
LOOK FOR STRONGER SW FLOW TO TAKE OVER ALOFT AT AT THE SFC THURSDAY
NIGHT THROUGH FRIDAY NIGHT...AHEAD OF THE NEARING TROUGH TO OUT W.
COOLER AIRMASS IS ON THE WAY FOR THE WEEKEND. WE CAN GET A GLIMPSE
OF WHAT IS TO COME BY LOOKING AT THE 00Z SATURDAY 850MB TEMPS ACROSS
THE REGION. 850MB TEMPS WILL LIKELY RANGE FROM 14-16Z ACROSS UPPER
MI...WHILE A MUCH COOLER 4-6C ACROSS NW ND. ONLY MINIMAL TS
POTENTIAL ALONG THE FRONT...GIVEN ITS NOCTURNAL PASSAGE OVER THE W
CWA SATURDAY MORNING. THERE ARE ENOUGH SIGNIFICANT DIFFERENCES
BETWEEN THE ECMWF AND GFS AT THIS POINT TO GO WITH A CONSENSUS
SOLUTION. THE 23/12Z RUN OF THE GFS IS AROUND 6HRS FASTER THAN THE
23/00Z ECMWF WITH THE PASSAGE OF THE SHORTWAVE. STILL...THEY ARE
STARTING TO COME TO A BETTER AGREEMENT WHEN COMPARED TO THE MUCH
QUICKER 23/06Z RUN OF THE GFS.
THE ENTIRE SYSTEM LOOKS TO MODERATE QUITE A BIT...WITH THE COOLEST
AIR FILTERING INTO UPPER MI BEING AROUND 5-7C SATURDAY NIGHT THROUGH
MONDAY MORNING. AS AN ASIDE...THE 23/12Z RUN OF THE GFS ONLY HAS
850MB TEMPS COOLING TO AROUND 10C. MUCH OF THIS IS DUE TO THE
DIFFERENCE IN THE HANDLING OF THE MID-UPPER LEVEL WAVE. THE ECMWF IS
PERSISTENT IN HAVING THE TROUGH OVER THE UPPER GREAT LAKES THIS
WEEKEND CUT OFF FROM THE MAIN W-E FLOW AND FORM A LOW
OVERHEAD...BEFORE DROPPING IT INTO THE MID MS VALLEY THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 747 PM EDT MON SEP 23 2013
VFR CONDITIONS SHOULD PREVAIL AT KIWD/KCMX/KSAW THRU THIS FCST
PERIOD UNDER A GENERALLY DRY AIR MASS ASSOCIATED WITH HIGH PRES OVER
ONTARIO/WRN QUEBEC. HOWEVER...THERE IS SOME CONCERN THAT LOW CLOUDS
COULD DEVELOP AT KSAW LATE TONIGHT UNDER SSE UPSLOPE FLOW OFF LAKE
MICHIGAN. SINCE CURRENT DWPTS OVER NRN LAKE MICHIGAN AREN`T
SIGNIFICANTLY HIGHER THAN EXPECTED MIN TEMPS TONIGHT...WILL CONTINUE
TO HOLD OFF ON INCLUDING A LOW MVFR OR EVEN IFR CIG AT KSAW FOR
NOW...BUT IT WILL BE SOMETHING TO MONITOR. UNDER TIGHTER PRES
GRADIENT...MARGINAL LLWS IS EXPECTED AT KIWD TONIGHT AS WINDS
INCREASE ABOVE NOCTURNAL INVERSION. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EDT MON SEP 23 2013
SLOW MOVING WEATHER PATTERN THIS WEEK WILL FEATURE HIGH PRES TO THE
E AND LOW PRES TO THE W. EVENTUALLY...A LOW PRES SYSTEM WILL MOVE NE
TO HUDSON BAY LATE WEEK WITH ASSOCIATED COLD FRONT PASSING ACROSS
LAKE SUPERIOR SAT. THRU THE WEEK...RELATIVELY WEAK PRES GRADIENT
WILL RESULT IN WINDS MOSTLY UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
136 PM EDT SUN SEP 22 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 323 AM EDT SUN SEP 22 2013
HIGH PRESSURE WILL MOVE OVER THE REGION THROUGH THE FIRST PART OF
THIS WEEK. THIS SYSTEM WILL BRING SUNNY AND MILD DAYS AND CHILLY
NIGHTS. FROST WILL BE POSSIBLE TONIGHT NORTH OF I-96.
TEMPERATURES WILL SLOWLY WARM INTO THE LATTER PART OF THE WEEK. THE
NEXT CHANCE OF RAIN SHOULD HOLD OFF UNTIL SATURDAY.
&&
.UPDATE...
ISSUED AT 1040 AM EDT SUN SEP 22 2013
IT IS CLEAR TO ME (PUN INTENDED) THE SKIES WILL IN FACT NOT BE
CLEAR ANY TIME SOON. THE AREA OF STRATOCUMULUS CLOUDS CONTINUES TO
EXPAND SOUTHWARD OVER THE SOUTHERN AND SOUTHWEST CWA. GIVEN THE
LACK OF ANY TREND FOR THE CLOUDS TO BREAK UP SOON I HAVE UPDATED
THE ZONES TO KEEP THE CLOUDS AROUND INTO EARLY THIS AFTERNOON. THE
LATEST MODEL RUNS... LIKE THE RAP AND THE OUTGOING LONGWAVE
RADIATION FEATURE ON THE HRRR 12Z RUN SUGGEST THE CLEARING WILL BE
MORE IN THE 2 TO TO 5 PM TIME FRAME. SO THAT IS WHERE I NOW HAVE
IT IN THE GRIDS. IF THE CLOUDS DO HANG AROUND INTO MID AFTERNOON
THE HIGHS WILL ONLY BE THE 50S... I LOWERED THE AFTERNOON TEMPS
ABOUT 2 DEGREES BUT THAT MAY NOT BE ENOUGH. WE SHALL SEE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 323 AM EDT SUN SEP 22 2013
FIRST CHALLENGE IN THE SHORT TERM WAS DETERMINING WHEN THE CLOUDS
OVER THE REGION WILL FINALLY CLEAR. THEN FROST/FREEZE POTENTIAL
BECOMES A CONCERN TONIGHT.
THE UPPER LOW OVER WESTERN QUEBEC CONTINUES TO BRING CHILLY NW FLOW
OVER THE REGION. THE COMBINATION OF MOISTURE WRAPPING AROUND THIS
LOW AND LAKE DELTA T/S AROUND 18...HAS HELD IN A SC DECK INTO EARLY
THIS MORNING. HOWEVER AS THE LOW SHIFTS TO EASTERN QUEBEC LATER
TODAY...SURFACE AND UPPER RIDGING MOVES INTO THE WESTERN GREAT LAKES
ALONG WITH WARM ADVECTION ALOFT BY AFTERNOON. SO BELIEVE THE CLOUDS
WILL ERODE FAIRLY QUICKLY ONCE THE SUN IS UP...AND MOSTLY SUNNY
SKIES CAN BE EXPECTED CWA-WIDE BY LATE MORNING.
THE SURFACE RIDGE WILL SIT OVER THE CWA TONIGHT BRINGING CLEAR SKIES
AND LIGHT WINDS. THIS WILL BE IDEAL RADIATION CONDITIONS AND
FROST/FREEZE HEADLINES WILL BE POSTED ACROSS THE NORTHERN CWA.
PATCHY FROST WILL BE POSSIBLE OVER THE SOUTHERN HALF TOO...BUT IT
SHOULD BE ISOLATED ENOUGH TO NOT WARRANT HEADLINES.
LITTLE WEATHER TO SPEAK OF FOR MONDAY AND TUESDAY. THE UPPER FLOW
REMAINS FAIRLY AMPLIFIED WHICH WILL KEEP THE PATTEN BLOCKED AND KEEP
THE SURFACE AND UPPER RIDGE NEARBY. TEMPS SHOULD MODERATE EACH
DAY...TO 70 TO 75 BY TUESDAY. FROST SHOULD LESS OF A THREAT MONDAY
NIGHT WITH SE LOW LEVEL FLOW DEVELOPING.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 323 AM EDT SUN SEP 22 2013
WARM AND DRY IS THE MAIN MESSAGE IN THE LONG TERM PERIOD AS A HIGH
AMPLITUDE UPPER LEVEL RIDGE DOMINATES OUR WEATHER. THIS FEATURE WILL
LEAD TO TEMPERATURES ABOUT 10 DEGREES ABOVE NORMAL WITH HIGHS IN THE
MID TO UPPER 70S AND LOWS IN THE 50S.
HAVE REMOVED THE LOW CHANCE OF SHOWERS FOR FRIDAY NIGHT BUT LEFT
THEM IN FOR SATURDAY DUE TO THE WET LOOK OF THE GFS. THE EURO ON THE
OTHER HAND IS A DAY SLOWER WITH THE FRONT AND SUGGESTS THE BETTER
RAIN CHANCES WOULD HOLD OFF UNTIL SATURDAY NIGHT OR SUNDAY. THIS MAY
BE MORE REASONABLE GIVEN THE HIGHLY AMPLIFIED UPPER RIDGE SO PERHAPS
IN FUTURE FORECASTS WE CAN GO DRY ON SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 134 PM EDT SUN SEP 22 2013
MVFR CIGS WILL IMPROVE TO VFR LATER THIS AFTERNOON BEFORE SKIES
SCATTER OUT THIS EVENING.
&&
.MARINE...
ISSUED AT 1124 AM EDT SUN SEP 22 2013
THE SMALL CRAFT ADVISORY HAS EXPIRED. WINDS ARE NOW GENERALLY
UNDER 10 KNOTS AND WAVE FOR THE MOST PART UNDER 2 FEET.
&&
.HYDROLOGY...
ISSUED AT 323 AM EDT SUN SEP 22 2013
NO RAIN IS EXPECTED UNTIL NEXT WEEKEND.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FREEZE WARNING FROM 2 AM TO 9 AM EDT MONDAY FOR MIZ039-040.
FROST ADVISORY FROM 2 AM TO 9 AM EDT MONDAY FOR MIZ037-038-
044>046-051.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MEADE
AVIATION...93
HYDROLOGY...JK
MARINE...WDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1148 AM EDT SUN SEP 22 2013
.UPDATE...
ISSUED AT 1147 AM EDT SUN SEP 22 2013
CONTINUE TO TRACK THE LATEST SATELLITE AND RADAR TRENDS...WHICH SHOW
ONLY SOME IMPROVEMENT TO THE LINGERING MID CLOUDS ACROSS MUCH OF THE
CWA. FAVORABLE NNE WINDS CONTINUE TO STREAM A FEW BROKEN LINES OF
SHOWERS/DRIZZLE OVER MAINLY ALGER AND DELTA COUNTY LATE THIS
MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT SUN SEP 22 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A CONFLUENT NW
FLOW ALF OVER THE UPR GREAT LKS BTWN UPR RDG IN THE PLAINS AND DEEP
UPR TROF EXTENDING FM HUDSON BAY/WRN QUEBEC S THRU THE APPALACHIANS.
SINCE THE PATTERN IS SLOWLY PROGRESSIVE...00Z RAOBS SHOWED 12Z-24Z
H3/H5 HGT RISES UP TO 100M FM NW ONTARIO INTO THE WRN GREAT LKS. THE
LARGER SCALE SUBSIDENCE ASSOCIATED WITH THESE DYANMICS ARE
SUPPORTING A SFC HI PRES FM NW ONTARIO THRU WRN LK SUP AND INTO WI.
BUT SINCE THE 00Z YPL RAOB SHOWS MSTR TRAPPED WITHIN LLVL THERMAL
TROF DIPPING INTO THE GREAT LKS AND UNDER SUBSIDENCE INVRN NEAR
H85...THERE ARE AREAS OF LK EFFECT SC OVER PORTIONS OF UPR MI IN
SLOWLY VEERING LLVL NLY FLOW E OF THE RDG AXIS. H85 TEMPS AS LO AS
-3C OVER THE E HALF OF LK SUP ARE SUPPORTING ISOLD LK EFFECT -SHRA
AS WELL IN THAT AREA. THE WRN EDGE OF THE SC IS RIGHT UP TO RDG AXIS
NEAR IWD AT 06Z. TO THE W OF THIS LINE...MUCH DRIER AIR SHOWN ON THE
00Z INL RAOB IS BRING CLR SKIES. H85 TEMPS WARM FAIRLY STEADILY TO
THE W...WITH THE 00Z TEMP UP TO 13C AT ABERDEEM SDAKOTA AND BISMARCK
IN THE LARGE SCALE SLY FLOW W OF THE RDG AXIS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LK EFFECT CLD/-SHRA TRENDS.
FOCUS FOR TNGT SHIFTS TO THE PROSPECT OF MORE FROST WITH THE HI PRES
MOVING GRADUALLY TO THE E IN THE SLOWLY PROGRESSIVE UPR PATTERN.
TODAY...SFC HI PRES RDG AXIS IS PROGGED TO DRIFT SLOWLY E THRU THE
DAY...REACHING THE ERN CWA BY 00Z MON. WITH LARGER SCALE SUBSIDENCE
WARMING THE H85 TEMPS/STRENGTHENING INVRN...EXPECT ANY LINGERING LK
EFFECT -SHRA TO DIMINISH EARLY TODAY. AS OBSVD EARLY THIS MRNG...
PASSAGE OF RDG AXIS/MORE ACYC LLVL FLOW AS WELL AS DAYTIME HEATING/
MIXING SHOULD RESULT IN AN EROSION OF LINGERING LK CLDS AS WELL. THE
SC WL BE MOST RESILIENT OVER THE NCENTRAL THIS MRNG WITH UPSLOPE NNE
WIND COMPONENT...WITH LINGERING LLVL MSTR/THERMAL TROFFING TO THE E
OF THE ENCROACHING RDG AXIS ALLOWING FOR AT LEAST MORE DAYTIME CU/SC
OVER THE ERN CWA INTO THE AFTN. SUBSIDENCE WARMING/RETURN SLY FLOW
TO THE W OF THE HI PRES IS PROGGED TO LIFT H85 TEMPS NEAR 10C AT IWD
BY 00Z MON. WITH A GOOD DEAL OF SUNSHINE IN THIS AREA...EXPECT HI
TEMPS TO REACH 60 TO 65 OVER THE W AWAY FM LK MODERATION.
TNGT...THE SFC RDG AXIS IS FCST TO DRIFT ONLY SLOWLY E OF THE SAULT
TNGT. WITH CLEAR SKIES AND PWAT 0.33 TO 0.50 INCH /AS LO AS 60 PCT
OF NORMAL/...EXPECT A FAVORABLE SETUP FOR A SHARP DIURNAL TEMP FALL
OVER THE E HALF OF THE CWA...WHERE THE PRES GRADIENT IS FCST TO BE
RATHER FLAT AND H925 WINDS NO MORE THAN ABOUT 10 KTS THRU 12Z MON.
WL TEND TOWARD THE LO END OF GUIDANCE FOR MIN TEMPS OVER THE
INTERIOR E HALF...WHERE FROST IS LIKELY. OVER THE W...A STRONGER
RETURN FLOW WITH S H925 WINDS UP TO 20-25 KTS WL MITIGATE THE
DIURNAL DROP. PLAN TO ISSUE A FROST ADVY FOR THE E AND CENTRAL
PORTION OF THE CWA. BUT WL WAIT UNTIL THE CURRENT ADVY EXPIRES AT
12Z TO ISSUE THE HEADLINE/STATEMENT TO AVOID CONFUSION.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM EDT SUN SEP 22 2013
A DRY AND WARMER THAN NORMAL START TO FALL IS EXPECTED THIS WEEK.
THIS IS DUE TO THE UPPER TROUGH THAT MOVED THROUGH THE AREA THIS
MORNING SLOWLY MOVING THROUGH THE CANADIAN MARITIMES THIS WEEK.
THIS WILL SETUP A BLOCK AND KEEP THE UPSTREAM CONDITIONS LOCKED IN
PLACE FOR MUCH OF THE UPCOMING WORK WEEK. FOR THE UPPER GREAT LAKES
REGION...THIS MEANS AN UPPER RIDGE WILL BE OVER THE AREA WITH A
SURFACE HIGH JUST TO THE EAST OF THE AREA. THUS...EXPECT SOUTHERLY
FLOW TO PULL WARMER AIR NORTH AND LEAD TO A WEEK OF ABOVE NORMAL
TEMPERATURES AND REALLY NICE LATE SEPTEMBER WEATHER.
EXPECT MOSTLY CLEAR THROUGH MUCH OF THE WEEK...ALTHOUGH THERE
ARE SOME HINTS OF DIURNAL CU DEVELOPING OVER THE EAST WITH SOME
MOISTENING OFF LAKE MICHIGAN WHEN THE SOUTHERLY FLOW DEVELOPS. DID
TRY TO SHOW THAT POTENTIAL ON MONDAY/TUESDAY FOR A PERIOD DURING
PEAK AFTERNOON HEATING. HIGHS MOST DAYS THIS WEEK WILL BE IN THE
UPPER 60S AND LOWER 70S THIS WEEK WITH LOWS IN THE 40S/50S.
MAIN CONCERNS FOR WEATHER WILL BE A SHORTWAVE EXITING THE CENTRAL
PLAINS ON TUESDAY...BUT IS SHOULD FALL APART BEFORE REACHING THE
AREA AND KEEP THINGS DRY. 00Z GFS DOES TRY TO PUT SOME PRECIP
INTO IRONWOOD TUESDAY AFTERNOON/EVENING...BUT WITH 00Z NAM/GEM/ECMWF
AND OUR WRF-ARW KEEPING IT DRY...WILL FOLLOW THAT IDEA. ONLY AFFECT
IT SHOULD HAVE ON THE U.P. IS SOME MID-HIGH CLOUDS...MAINLY OVER THE
WESTERN THIRD OF THE CWA.
ANOTHER UPPER TROUGH WILL EXIT THE ROCKIES ON FRIDAY AND THIS ONE
ALSO LOOKS TO STRUGGLE WITH THE BLOCKING UPPER RIDGE IN THE GREAT
LAKES REGION. MODELS HAVE DIFFERING SOLUTIONS ON HOW THIS SYSTEM
WILL EVOLVE HEADING INTO THE WEEKEND...SO WILL FOLLOW A GENERAL
CONSENSUS OF PRECIPITATION CHANCE INCREASING FRIDAY NIGHT INTO
SATURDAY AS THE UPPER TROUGH SWEEPS EAST-NORTHEAST THROUGH THE
AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1147 AM EDT SUN SEP 22 2013
PESKY LOW VFR TO HIGH END MVFR CEILINGS ARE HAVING A DIFFICULT TIME
EXITING TODAY. EVEN IWD WHICH HAD BEEN CLEAR FROM 11Z-15Z QUICKLY
FILLED BACK WITH MVFR CEILINGS AS LINGERING LOW LEVEL MOISTURE AND
WSW WINDS WRAPPED CLOUDS BACK INTO THE AREA. WILL CONTINUE TO SEE
SLOW IMPROVEMENT IN THE CLOUD COVER THROUGH THE AFTERNOON
HOURS...WITH LITTLE TO NO CLOUDS REMAINING BY SUNSET. THE MAIN
CONCERN OVERNIGHT WILL BE INCREASING WINDS BETWEEN THE SLOWLY
EXITING HIGH PRESSURE SYSTEM...AND AN ELONGATED AREA OF LOW PRESSURE
ACROSS THE PLAINS. LLWS WILL REMAIN A POSSIBILITY AT IWD WITH
25-35KT WINDS POSSIBLE JUST ABOVE THE SFC FROM 03-15Z MONDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 AM EDT SUN SEP 22 2013
HIGH PRESSURE CURRENTLY OVER LAKE SUPERIOR WILL SLIDE EAST OVER
THE LOWER GREAT LAKES AND EASTERN ONTARIO TONIGHT AND THEN REMAINING
STATIONARY THROUGH MUCH OF THE UPCOMING WORK WEEK. WHILE THIS
OCCURS...SOUTHERLY FLOW WILL INCREASE SLIGHTLY STARTING
TONIGHT...BUT EXPECT THE WINDS TO BE BELOW 20KTS FOR MOST OF
THE PERIOD. THE PERIODS OF THE STRONGEST WINDS LOOK TO BE MONDAY
NIGHT (AS AN AREA OF LOW PRESSURE MOVES OUT OF THE PLAINS AND
DISSIPATES) AND ON THURSDAY NIGHT INTO FRIDAY NIGHT (AS ANOTHER LOW
MOVES OUT OF THE CENTRAL PLAINS AND INTO WESTERN ONTARIO). DURING
THOSE TIME PERIODS...THERE COULD BE SLIGHTLY HIGHER GUSTS TO
25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM 2 AM EDT /1 AM CDT/ TO 8 AM EDT /7 AM CDT/
MONDAY FOR MIZ004>007-010>014-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KF
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1124 AM EDT SUN SEP 22 2013
LATEST UPDATE...
MARINE
.SYNOPSIS...
ISSUED AT 323 AM EDT SUN SEP 22 2013
HIGH PRESSURE WILL MOVE OVER THE REGION THROUGH THE FIRST PART OF
THIS WEEK. THIS SYSTEM WILL BRING SUNNY AND MILD DAYS AND CHILLY
NIGHTS. FROST WILL BE POSSIBLE TONIGHT NORTH OF I-96.
TEMPERATURES WILL SLOWLY WARM INTO THE LATTER PART OF THE WEEK. THE
NEXT CHANCE OF RAIN SHOULD HOLD OFF UNTIL SATURDAY.
&&
.UPDATE...
ISSUED AT 1040 AM EDT SUN SEP 22 2013
IT IS CLEAR TO ME (PUN INTENDED) THE SKIES WILL IN FACT NOT BE
CLEAR ANY TIME SOON. THE AREA OF STRATOCUMULUS CLOUDS CONTINUES TO
EXPAND SOUTHWARD OVER THE SOUTHERN AND SOUTHWEST CWA. GIVEN THE
LACK OF ANY TREND FOR THE CLOUDS TO BREAK UP SOON I HAVE UPDATED
THE ZONES TO KEEP THE CLOUDS AROUND INTO EARLY THIS AFTERNOON. THE
LATEST MODEL RUNS... LIKE THE RAP AND THE OUTGOING LONGWAVE
RADIATION FEATURE ON THE HRRR 12Z RUN SUGGEST THE CLEARING WILL BE
MORE IN THE 2 TO TO 5 PM TIME FRAME. SO THAT IS WHERE I NOW HAVE
IT IN THE GRIDS. IF THE CLOUDS DO HANG AROUND INTO MID AFTERNOON
THE HIGHS WILL ONLY BE THE 50S... I LOWERED THE AFTERNOON TEMPS
ABOUT 2 DEGREES BUT THAT MAY NOT BE ENOUGH. WE SHALL SEE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 323 AM EDT SUN SEP 22 2013
FIRST CHALLENGE IN THE SHORT TERM WAS DETERMINING WHEN THE CLOUDS
OVER THE REGION WILL FINALLY CLEAR. THEN FROST/FREEZE POTENTIAL
BECOMES A CONCERN TONIGHT.
THE UPPER LOW OVER WESTERN QUEBEC CONTINUES TO BRING CHILLY NW FLOW
OVER THE REGION. THE COMBINATION OF MOISTURE WRAPPING AROUND THIS
LOW AND LAKE DELTA T/S AROUND 18...HAS HELD IN A SC DECK INTO EARLY
THIS MORNING. HOWEVER AS THE LOW SHIFTS TO EASTERN QUEBEC LATER
TODAY...SURFACE AND UPPER RIDGING MOVES INTO THE WESTERN GREAT LAKES
ALONG WITH WARM ADVECTION ALOFT BY AFTERNOON. SO BELIEVE THE CLOUDS
WILL ERODE FAIRLY QUICKLY ONCE THE SUN IS UP...AND MOSTLY SUNNY
SKIES CAN BE EXPECTED CWA-WIDE BY LATE MORNING.
THE SURFACE RIDGE WILL SIT OVER THE CWA TONIGHT BRINGING CLEAR SKIES
AND LIGHT WINDS. THIS WILL BE IDEAL RADIATION CONDITIONS AND
FROST/FREEZE HEADLINES WILL BE POSTED ACROSS THE NORTHERN CWA.
PATCHY FROST WILL BE POSSIBLE OVER THE SOUTHERN HALF TOO...BUT IT
SHOULD BE ISOLATED ENOUGH TO NOT WARRANT HEADLINES.
LITTLE WEATHER TO SPEAK OF FOR MONDAY AND TUESDAY. THE UPPER FLOW
REMAINS FAIRLY AMPLIFIED WHICH WILL KEEP THE PATTEN BLOCKED AND KEEP
THE SURFACE AND UPPER RIDGE NEARBY. TEMPS SHOULD MODERATE EACH
DAY...TO 70 TO 75 BY TUESDAY. FROST SHOULD LESS OF A THREAT MONDAY
NIGHT WITH SE LOW LEVEL FLOW DEVELOPING.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 323 AM EDT SUN SEP 22 2013
WARM AND DRY IS THE MAIN MESSAGE IN THE LONG TERM PERIOD AS A HIGH
AMPLITUDE UPPER LEVEL RIDGE DOMINATES OUR WEATHER. THIS FEATURE WILL
LEAD TO TEMPERATURES ABOUT 10 DEGREES ABOVE NORMAL WITH HIGHS IN THE
MID TO UPPER 70S AND LOWS IN THE 50S.
HAVE REMOVED THE LOW CHANCE OF SHOWERS FOR FRIDAY NIGHT BUT LEFT
THEM IN FOR SATURDAY DUE TO THE WET LOOK OF THE GFS. THE EURO ON THE
OTHER HAND IS A DAY SLOWER WITH THE FRONT AND SUGGESTS THE BETTER
RAIN CHANCES WOULD HOLD OFF UNTIL SATURDAY NIGHT OR SUNDAY. THIS MAY
BE MORE REASONABLE GIVEN THE HIGHLY AMPLIFIED UPPER RIDGE SO PERHAPS
IN FUTURE FORECASTS WE CAN GO DRY ON SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 732 AM EDT SUN SEP 22 2013
HIGH CONFIDENCE WIDESPREAD VFR CONDITIONS TODAY AND TONIGHT. NORTH
WINDS UNDER 10 KNOTS TODAY BECOMING LIGHT EAST TONIGHT.
&&
.MARINE...
ISSUED AT 1124 AM EDT SUN SEP 22 2013
THE SMALL CRAFT ADVISORY HAS EXPIRED. WINDS ARE NOW GENERALLY
UNDER 10 KNOTS AND WAVE FOR THE MOST PART UNDER 2 FEET.
&&
.HYDROLOGY...
ISSUED AT 323 AM EDT SUN SEP 22 2013
NO RAIN IS EXPECTED UNTIL NEXT WEEKEND.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FREEZE WARNING FROM 2 AM TO 9 AM EDT MONDAY FOR MIZ039-040.
FROST ADVISORY FROM 2 AM TO 9 AM EDT MONDAY FOR MIZ037-038-
044>046-051.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JK
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1040 AM EDT SUN SEP 22 2013
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 323 AM EDT SUN SEP 22 2013
HIGH PRESSURE WILL MOVE OVER THE REGION THROUGH THE FIRST PART OF
THIS WEEK. THIS SYSTEM WILL BRING SUNNY AND MILD DAYS AND CHILLY
NIGHTS. FROST WILL BE POSSIBLE TONIGHT NORTH OF I-96.
TEMPERATURES WILL SLOWLY WARM INTO THE LATTER PART OF THE WEEK. THE
NEXT CHANCE OF RAIN SHOULD HOLD OFF UNTIL SATURDAY.
&&
.UPDATE...
ISSUED AT 1040 AM EDT SUN SEP 22 2013
IT IS CLEAR TO ME (PUN INTENDED) THE SKIES WILL IN FACT NOT BE
CLEAR ANY TIME SOON. THE AREA OF STRATOCUMULUS CLOUDS CONTINUES TO
EXPAND SOUTHWARD OVER THE SOUTHERN AND SOUTHWEST CWA. GIVEN THE
LACK OF ANY TREND FOR THE CLOUDS TO BREAK UP SOON I HAVE UPDATED
THE ZONES TO KEEP THE CLOUDS AROUND INTO EARLY THIS AFTERNOON. THE
LATEST MODEL RUNS... LIKE THE RAP AND THE OUTGOING LONGWAVE
RADIATION FEATURE ON THE HRRR 12Z RUN SUGGEST THE CLEARING WILL BE
MORE IN THE 2 TO TO 5 PM TIME FRAME. SO THAT IS WHERE I NOW HAVE
IT IN THE GRIDS. IF THE CLOUDS DO HANG AROUND INTO MID AFTERNOON
THE HIGHS WILL ONLY BE THE 50S... I LOWERED THE AFTERNOON TEMPS
ABOUT 2 DEGREES BUT THAT MAY NOT BE ENOUGH. WE SHALL SEE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 323 AM EDT SUN SEP 22 2013
FIRST CHALLENGE IN THE SHORT TERM WAS DETERMINING WHEN THE CLOUDS
OVER THE REGION WILL FINALLY CLEAR. THEN FROST/FREEZE POTENTIAL
BECOMES A CONCERN TONIGHT.
THE UPPER LOW OVER WESTERN QUEBEC CONTINUES TO BRING CHILLY NW FLOW
OVER THE REGION. THE COMBINATION OF MOISTURE WRAPPING AROUND THIS
LOW AND LAKE DELTA T/S AROUND 18...HAS HELD IN A SC DECK INTO EARLY
THIS MORNING. HOWEVER AS THE LOW SHIFTS TO EASTERN QUEBEC LATER
TODAY...SURFACE AND UPPER RIDGING MOVES INTO THE WESTERN GREAT LAKES
ALONG WITH WARM ADVECTION ALOFT BY AFTERNOON. SO BELIEVE THE CLOUDS
WILL ERODE FAIRLY QUICKLY ONCE THE SUN IS UP...AND MOSTLY SUNNY
SKIES CAN BE EXPECTED CWA-WIDE BY LATE MORNING.
THE SURFACE RIDGE WILL SIT OVER THE CWA TONIGHT BRINGING CLEAR SKIES
AND LIGHT WINDS. THIS WILL BE IDEAL RADIATION CONDITIONS AND
FROST/FREEZE HEADLINES WILL BE POSTED ACROSS THE NORTHERN CWA.
PATCHY FROST WILL BE POSSIBLE OVER THE SOUTHERN HALF TOO...BUT IT
SHOULD BE ISOLATED ENOUGH TO NOT WARRANT HEADLINES.
LITTLE WEATHER TO SPEAK OF FOR MONDAY AND TUESDAY. THE UPPER FLOW
REMAINS FAIRLY AMPLIFIED WHICH WILL KEEP THE PATTEN BLOCKED AND KEEP
THE SURFACE AND UPPER RIDGE NEARBY. TEMPS SHOULD MODERATE EACH
DAY...TO 70 TO 75 BY TUESDAY. FROST SHOULD LESS OF A THREAT MONDAY
NIGHT WITH SE LOW LEVEL FLOW DEVELOPING.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 323 AM EDT SUN SEP 22 2013
WARM AND DRY IS THE MAIN MESSAGE IN THE LONG TERM PERIOD AS A HIGH
AMPLITUDE UPPER LEVEL RIDGE DOMINATES OUR WEATHER. THIS FEATURE WILL
LEAD TO TEMPERATURES ABOUT 10 DEGREES ABOVE NORMAL WITH HIGHS IN THE
MID TO UPPER 70S AND LOWS IN THE 50S.
HAVE REMOVED THE LOW CHANCE OF SHOWERS FOR FRIDAY NIGHT BUT LEFT
THEM IN FOR SATURDAY DUE TO THE WET LOOK OF THE GFS. THE EURO ON THE
OTHER HAND IS A DAY SLOWER WITH THE FRONT AND SUGGESTS THE BETTER
RAIN CHANCES WOULD HOLD OFF UNTIL SATURDAY NIGHT OR SUNDAY. THIS MAY
BE MORE REASONABLE GIVEN THE HIGHLY AMPLIFIED UPPER RIDGE SO PERHAPS
IN FUTURE FORECASTS WE CAN GO DRY ON SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 732 AM EDT SUN SEP 22 2013
HIGH CONFIDENCE WIDESPREAD VFR CONDITIONS TODAY AND TONIGHT. NORTH
WINDS UNDER 10 KNOTS TODAY BECOMING LIGHT EAST TONIGHT.
&&
.MARINE...
ISSUED AT 323 AM EDT SUN SEP 22 2013
EXTENDED THE SCA OVER THE LDM REGION THROUGH THE MORNING AS A NNE
FLOW WILL KEEP THE WAVES HIGHER IN THIS REGION. SOUTHERN AREAS WILL
BE MORE SHELTER FROM THE NNE WIND AND WILL SEE LOWER WAVES. WITH
HIGH PRESSURE MOVING IN...THE REST OF THE SHORT TERM LOOKS QUIET ON
THE LAKE.
&&
.HYDROLOGY...
ISSUED AT 323 AM EDT SUN SEP 22 2013
NO RAIN IS EXPECTED UNTIL NEXT WEEKEND.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FREEZE WARNING FROM 2 AM TO 9 AM EDT MONDAY FOR MIZ039-040.
FROST ADVISORY FROM 2 AM TO 9 AM EDT MONDAY FOR MIZ037-038-
044>046-051.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR LMZ849.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
725 AM EDT SUN SEP 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT SUN SEP 22 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A CONFLUENT NW
FLOW ALF OVER THE UPR GREAT LKS BTWN UPR RDG IN THE PLAINS AND DEEP
UPR TROF EXTENDING FM HUDSON BAY/WRN QUEBEC S THRU THE APPALACHIANS.
SINCE THE PATTERN IS SLOWLY PROGRESSIVE...00Z RAOBS SHOWED 12Z-24Z
H3/H5 HGT RISES UP TO 100M FM NW ONTARIO INTO THE WRN GREAT LKS. THE
LARGER SCALE SUBSIDENCE ASSOCIATED WITH THESE DYANMICS ARE
SUPPORTING A SFC HI PRES FM NW ONTARIO THRU WRN LK SUP AND INTO WI.
BUT SINCE THE 00Z YPL RAOB SHOWS MSTR TRAPPED WITHIN LLVL THERMAL
TROF DIPPING INTO THE GREAT LKS AND UNDER SUBSIDENCE INVRN NEAR
H85...THERE ARE AREAS OF LK EFFECT SC OVER PORTIONS OF UPR MI IN
SLOWLY VEERING LLVL NLY FLOW E OF THE RDG AXIS. H85 TEMPS AS LO AS
-3C OVER THE E HALF OF LK SUP ARE SUPPORTING ISOLD LK EFFECT -SHRA
AS WELL IN THAT AREA. THE WRN EDGE OF THE SC IS RIGHT UP TO RDG AXIS
NEAR IWD AT 06Z. TO THE W OF THIS LINE...MUCH DRIER AIR SHOWN ON THE
00Z INL RAOB IS BRING CLR SKIES. H85 TEMPS WARM FAIRLY STEADILY TO
THE W...WITH THE 00Z TEMP UP TO 13C AT ABERDEEM SDAKOTA AND BISMARCK
IN THE LARGE SCALE SLY FLOW W OF THE RDG AXIS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LK EFFECT CLD/-SHRA TRENDS.
FOCUS FOR TNGT SHIFTS TO THE PROSPECT OF MORE FROST WITH THE HI PRES
MOVING GRADUALLY TO THE E IN THE SLOWLY PROGRESSIVE UPR PATTERN.
TODAY...SFC HI PRES RDG AXIS IS PROGGED TO DRIFT SLOWLY E THRU THE
DAY...REACHING THE ERN CWA BY 00Z MON. WITH LARGER SCALE SUBSIDENCE
WARMING THE H85 TEMPS/STRENGTHENING INVRN...EXPECT ANY LINGERING LK
EFFECT -SHRA TO DIMINISH EARLY TODAY. AS OBSVD EARLY THIS MRNG...
PASSAGE OF RDG AXIS/MORE ACYC LLVL FLOW AS WELL AS DAYTIME HEATING/
MIXING SHOULD RESULT IN AN EROSION OF LINGERING LK CLDS AS WELL. THE
SC WL BE MOST RESILIENT OVER THE NCENTRAL THIS MRNG WITH UPSLOPE NNE
WIND COMPONENT...WITH LINGERING LLVL MSTR/THERMAL TROFFING TO THE E
OF THE ENCROACHING RDG AXIS ALLOWING FOR AT LEAST MORE DAYTIME CU/SC
OVER THE ERN CWA INTO THE AFTN. SUBSIDENCE WARMING/RETURN SLY FLOW
TO THE W OF THE HI PRES IS PROGGED TO LIFT H85 TEMPS NEAR 10C AT IWD
BY 00Z MON. WITH A GOOD DEAL OF SUNSHINE IN THIS AREA...EXPECT HI
TEMPS TO REACH 60 TO 65 OVER THE W AWAY FM LK MODERATION.
TNGT...THE SFC RDG AXIS IS FCST TO DRIFT ONLY SLOWLY E OF THE SAULT
TNGT. WITH CLEAR SKIES AND PWAT 0.33 TO 0.50 INCH /AS LO AS 60 PCT
OF NORMAL/...EXPECT A FAVORABLE SETUP FOR A SHARP DIURNAL TEMP FALL
OVER THE E HALF OF THE CWA...WHERE THE PRES GRADIENT IS FCST TO BE
RATHER FLAT AND H925 WINDS NO MORE THAN ABOUT 10 KTS THRU 12Z MON.
WL TEND TOWARD THE LO END OF GUIDANCE FOR MIN TEMPS OVER THE
INTERIOR E HALF...WHERE FROST IS LIKELY. OVER THE W...A STRONGER
RETURN FLOW WITH S H925 WINDS UP TO 20-25 KTS WL MITIGATE THE
DIURNAL DROP. PLAN TO ISSUE A FROST ADVY FOR THE E AND CENTRAL
PORTION OF THE CWA. BUT WL WAIT UNTIL THE CURRENT ADVY EXPIRES AT
12Z TO ISSUE THE HEADLINE/STATEMENT TO AVOID CONFUSION.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM EDT SUN SEP 22 2013
A DRY AND WARMER THAN NORMAL START TO FALL IS EXPECTED THIS WEEK.
THIS IS DUE TO THE UPPER TROUGH THAT MOVED THROUGH THE AREA THIS
MORNING SLOWLY MOVING THROUGH THE CANADIAN MARITIMES THIS WEEK.
THIS WILL SETUP A BLOCK AND KEEP THE UPSTREAM CONDITIONS LOCKED IN
PLACE FOR MUCH OF THE UPCOMING WORK WEEK. FOR THE UPPER GREAT LAKES
REGION...THIS MEANS AN UPPER RIDGE WILL BE OVER THE AREA WITH A
SURFACE HIGH JUST TO THE EAST OF THE AREA. THUS...EXPECT SOUTHERLY
FLOW TO PULL WARMER AIR NORTH AND LEAD TO A WEEK OF ABOVE NORMAL
TEMPERATURES AND REALLY NICE LATE SEPTEMBER WEATHER.
EXPECT MOSTLY CLEAR THROUGH MUCH OF THE WEEK...ALTHOUGH THERE
ARE SOME HINTS OF DIURNAL CU DEVELOPING OVER THE EAST WITH SOME
MOISTENING OFF LAKE MICHIGAN WHEN THE SOUTHERLY FLOW DEVELOPS. DID
TRY TO SHOW THAT POTENTIAL ON MONDAY/TUESDAY FOR A PERIOD DURING
PEAK AFTERNOON HEATING. HIGHS MOST DAYS THIS WEEK WILL BE IN THE
UPPER 60S AND LOWER 70S THIS WEEK WITH LOWS IN THE 40S/50S.
MAIN CONCERNS FOR WEATHER WILL BE A SHORTWAVE EXITING THE CENTRAL
PLAINS ON TUESDAY...BUT IS SHOULD FALL APART BEFORE REACHING THE
AREA AND KEEP THINGS DRY. 00Z GFS DOES TRY TO PUT SOME PRECIP
INTO IRONWOOD TUESDAY AFTERNOON/EVENING...BUT WITH 00Z NAM/GEM/ECMWF
AND OUR WRF-ARW KEEPING IT DRY...WILL FOLLOW THAT IDEA. ONLY AFFECT
IT SHOULD HAVE ON THE U.P. IS SOME MID-HIGH CLOUDS...MAINLY OVER THE
WESTERN THIRD OF THE CWA.
ANOTHER UPPER TROUGH WILL EXIT THE ROCKIES ON FRIDAY AND THIS ONE
ALSO LOOKS TO STRUGGLE WITH THE BLOCKING UPPER RIDGE IN THE GREAT
LAKES REGION. MODELS HAVE DIFFERING SOLUTIONS ON HOW THIS SYSTEM
WILL EVOLVE HEADING INTO THE WEEKEND...SO WILL FOLLOW A GENERAL
CONSENSUS OF PRECIPITATION CHANCE INCREASING FRIDAY NIGHT INTO
SATURDAY AS THE UPPER TROUGH SWEEPS EAST-NORTHEAST THROUGH THE
AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 723 AM EDT SUN SEP 22 2013
EXPECT LO CLDS...WITH MVFR CIGS AT SAW AND POSSIBLY CMX THIS
MRNG...TO CLR BY EARLY AFTN WITH SLOW PASSAGE OF SFC HI PRES RDG
MOVING INTO THE UPR GREAT LKS. THEN VFR WX WL PREVAIL AS DRY AIRMASS
NOTED ON THE 00Z INL RAOB SHIFTS E OVER UPR MI WITH THE HI PRES RDG.
A SHARPENING PRES GRADIENT ON THE WRN FLANK OF THIS SFC HI WL DVLP
OVER WRN UPR MI LATER TNGT. AS THE S WIND STRENGTHENS ABV RADIATION
INVRN/DECOUPLED NEAR SFC LYR...LLWS WL IMPACT IWD AFT 23/06Z.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 AM EDT SUN SEP 22 2013
HIGH PRESSURE CURRENTLY OVER LAKE SUPERIOR WILL SLIDE EAST OVER
THE LOWER GREAT LAKES AND EASTERN ONTARIO TONIGHT AND THEN REMAINING
STATIONARY THROUGH MUCH OF THE UPCOMING WORK WEEK. WHILE THIS
OCCURS...SOUTHERLY FLOW WILL INCREASE SLIGHTLY STARTING
TONIGHT...BUT EXPECT THE WINDS TO BE BELOW 20KTS FOR MOST OF
THE PERIOD. THE PERIODS OF THE STRONGEST WINDS LOOK TO BE MONDAY
NIGHT (AS AN AREA OF LOW PRESSURE MOVES OUT OF THE PLAINS AND
DISSIPATES) AND ON THURSDAY NIGHT INTO FRIDAY NIGHT (AS ANOTHER LOW
MOVES OUT OF THE CENTRAL PLAINS AND INTO WESTERN ONTARIO). DURING
THOSE TIME PERIODS...THERE COULD BE SLIGHTLY HIGHER GUSTS TO
25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM 2 AM EDT /1 AM CDT/ TO 8 AM EDT /7 AM CDT/
MONDAY FOR MIZ004>007-010>014-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
359 AM EDT SUN SEP 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT SUN SEP 22 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A CONFLUENT NW
FLOW ALF OVER THE UPR GREAT LKS BTWN UPR RDG IN THE PLAINS AND DEEP
UPR TROF EXTENDING FM HUDSON BAY/WRN QUEBEC S THRU THE APPALACHIANS.
SINCE THE PATTERN IS SLOWLY PROGRESSIVE...00Z RAOBS SHOWED 12Z-24Z
H3/H5 HGT RISES UP TO 100M FM NW ONTARIO INTO THE WRN GREAT LKS. THE
LARGER SCALE SUBSIDENCE ASSOCIATED WITH THESE DYANMICS ARE
SUPPORTING A SFC HI PRES FM NW ONTARIO THRU WRN LK SUP AND INTO WI.
BUT SINCE THE 00Z YPL RAOB SHOWS MSTR TRAPPED WITHIN LLVL THERMAL
TROF DIPPING INTO THE GREAT LKS AND UNDER SUBSIDENCE INVRN NEAR
H85...THERE ARE AREAS OF LK EFFECT SC OVER PORTIONS OF UPR MI IN
SLOWLY VEERING LLVL NLY FLOW E OF THE RDG AXIS. H85 TEMPS AS LO AS
-3C OVER THE E HALF OF LK SUP ARE SUPPORTING ISOLD LK EFFECT -SHRA
AS WELL IN THAT AREA. THE WRN EDGE OF THE SC IS RIGHT UP TO RDG AXIS
NEAR IWD AT 06Z. TO THE W OF THIS LINE...MUCH DRIER AIR SHOWN ON THE
00Z INL RAOB IS BRING CLR SKIES. H85 TEMPS WARM FAIRLY STEADILY TO
THE W...WITH THE 00Z TEMP UP TO 13C AT ABERDEEM SDAKOTA AND BISMARCK
IN THE LARGE SCALE SLY FLOW W OF THE RDG AXIS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LK EFFECT CLD/-SHRA TRENDS.
FOCUS FOR TNGT SHIFTS TO THE PROSPECT OF MORE FROST WITH THE HI PRES
MOVING GRADUALLY TO THE E IN THE SLOWLY PROGRESSIVE UPR PATTERN.
TODAY...SFC HI PRES RDG AXIS IS PROGGED TO DRIFT SLOWLY E THRU THE
DAY...REACHING THE ERN CWA BY 00Z MON. WITH LARGER SCALE SUBSIDENCE
WARMING THE H85 TEMPS/STRENGTHENING INVRN...EXPECT ANY LINGERING LK
EFFECT -SHRA TO DIMINISH EARLY TODAY. AS OBSVD EARLY THIS MRNG...
PASSAGE OF RDG AXIS/MORE ACYC LLVL FLOW AS WELL AS DAYTIME HEATING/
MIXING SHOULD RESULT IN AN EROSION OF LINGERING LK CLDS AS WELL. THE
SC WL BE MOST RESILIENT OVER THE NCENTRAL THIS MRNG WITH UPSLOPE NNE
WIND COMPONENT...WITH LINGERING LLVL MSTR/THERMAL TROFFING TO THE E
OF THE ENCROACHING RDG AXIS ALLOWING FOR AT LEAST MORE DAYTIME CU/SC
OVER THE ERN CWA INTO THE AFTN. SUBSIDENCE WARMING/RETURN SLY FLOW
TO THE W OF THE HI PRES IS PROGGED TO LIFT H85 TEMPS NEAR 10C AT IWD
BY 00Z MON. WITH A GOOD DEAL OF SUNSHINE IN THIS AREA...EXPECT HI
TEMPS TO REACH 60 TO 65 OVER THE W AWAY FM LK MODERATION.
TNGT...THE SFC RDG AXIS IS FCST TO DRIFT ONLY SLOWLY E OF THE SAULT
TNGT. WITH CLEAR SKIES AND PWAT 0.33 TO 0.50 INCH /AS LO AS 60 PCT
OF NORMAL/...EXPECT A FAVORABLE SETUP FOR A SHARP DIURNAL TEMP FALL
OVER THE E HALF OF THE CWA...WHERE THE PRES GRADIENT IS FCST TO BE
RATHER FLAT AND H925 WINDS NO MORE THAN ABOUT 10 KTS THRU 12Z MON.
WL TEND TOWARD THE LO END OF GUIDANCE FOR MIN TEMPS OVER THE
INTERIOR E HALF...WHERE FROST IS LIKELY. OVER THE W...A STRONGER
RETURN FLOW WITH S H925 WINDS UP TO 20-25 KTS WL MITIGATE THE
DIURNAL DROP. PLAN TO ISSUE A FROST ADVY FOR THE E AND CENTRAL
PORTION OF THE CWA. BUT WL WAIT UNTIL THE CURRENT ADVY EXPIRES AT
12Z TO ISSUE THE HEADLINE/STATEMENT TO AVOID CONFUSION.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM EDT SUN SEP 22 2013
A DRY AND WARMER THAN NORMAL START TO FALL IS EXPECTED THIS WEEK.
THIS IS DUE TO THE UPPER TROUGH THAT MOVED THROUGH THE AREA THIS
MORNING SLOWLY MOVING THROUGH THE CANADIAN MARITIMES THIS WEEK.
THIS WILL SETUP A BLOCK AND KEEP THE UPSTREAM CONDITIONS LOCKED IN
PLACE FOR MUCH OF THE UPCOMING WORK WEEK. FOR THE UPPER GREAT LAKES
REGION...THIS MEANS AN UPPER RIDGE WILL BE OVER THE AREA WITH A
SURFACE HIGH JUST TO THE EAST OF THE AREA. THUS...EXPECT SOUTHERLY
FLOW TO PULL WARMER AIR NORTH AND LEAD TO A WEEK OF ABOVE NORMAL
TEMPERATURES AND REALLY NICE LATE SEPTEMBER WEATHER.
EXPECT MOSTLY CLEAR THROUGH MUCH OF THE WEEK...ALTHOUGH THERE
ARE SOME HINTS OF DIURNAL CU DEVELOPING OVER THE EAST WITH SOME
MOISTENING OFF LAKE MICHIGAN WHEN THE SOUTHERLY FLOW DEVELOPS. DID
TRY TO SHOW THAT POTENTIAL ON MONDAY/TUESDAY FOR A PERIOD DURING
PEAK AFTERNOON HEATING. HIGHS MOST DAYS THIS WEEK WILL BE IN THE
UPPER 60S AND LOWER 70S THIS WEEK WITH LOWS IN THE 40S/50S.
MAIN CONCERNS FOR WEATHER WILL BE A SHORTWAVE EXITING THE CENTRAL
PLAINS ON TUESDAY...BUT IS SHOULD FALL APART BEFORE REACHING THE
AREA AND KEEP THINGS DRY. 00Z GFS DOES TRY TO PUT SOME PRECIP
INTO IRONWOOD TUESDAY AFTERNOON/EVENING...BUT WITH 00Z NAM/GEM/ECMWF
AND OUR WRF-ARW KEEPING IT DRY...WILL FOLLOW THAT IDEA. ONLY AFFECT
IT SHOULD HAVE ON THE U.P. IS SOME MID-HIGH CLOUDS...MAINLY OVER THE
WESTERN THIRD OF THE CWA.
ANOTHER UPPER TROUGH WILL EXIT THE ROCKIES ON FRIDAY AND THIS ONE
ALSO LOOKS TO STRUGGLE WITH THE BLOCKING UPPER RIDGE IN THE GREAT
LAKES REGION. MODELS HAVE DIFFERING SOLUTIONS ON HOW THIS SYSTEM
WILL EVOLVE HEADING INTO THE WEEKEND...SO WILL FOLLOW A GENERAL
CONSENSUS OF PRECIPITATION CHANCE INCREASING FRIDAY NIGHT INTO
SATURDAY AS THE UPPER TROUGH SWEEPS EAST-NORTHEAST THROUGH THE
AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 132 AM EDT SUN SEP 22 2013
VFR CONDITIONS WILL PREVAIL THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW
AS SFC HIGH PRES RIDGE BUILDS OVER THE AREA. INITIALLY...THERE WILL
BE LAKE EFFECT STRATOCU OFF LAKE SUPERIOR OVERNIGHT. CLOUD BASES
SHOULD BE ABOVE 3KFT...THOUGH THERE MAY BE BRIEF MVFR CIGS AT KSAW
AS NORTHERLY FLOW IS MORE SHARPLY UPSLOPING THERE. IN ADDITION...
THERE MAY BE A FEW LAKE EFFECT -SHRA AROUND KSAW FOR A PORTION OF
THE NIGHT. ANY LINGERING STRATOCU WILL DISSIPATE LATE MORNING/EARLY
AFTN...LEAVING CLEAR SKIES FOR THE REMAINDER OF THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 AM EDT SUN SEP 22 2013
HIGH PRESSURE CURRENTLY OVER LAKE SUPERIOR WILL SLIDE EAST OVER
THE LOWER GREAT LAKES AND EASTERN ONTARIO TONIGHT AND THEN REMAINING
STATIONARY THROUGH MUCH OF THE UPCOMING WORK WEEK. WHILE THIS
OCCURS...SOUTHERLY FLOW WILL INCREASE SLIGHTLY STARTING
TONIGHT...BUT EXPECT THE WINDS TO BE BELOW 20KTS FOR MOST OF
THE PERIOD. THE PERIODS OF THE STRONGEST WINDS LOOK TO BE MONDAY
NIGHT (AS AN AREA OF LOW PRESSURE MOVES OUT OF THE PLAINS AND
DISSIPATES) AND ON THURSDAY NIGHT INTO FRIDAY NIGHT (AS ANOTHER LOW
MOVES OUT OF THE CENTRAL PLAINS AND INTO WESTERN ONTARIO). DURING
THOSE TIME PERIODS...THERE COULD BE SLIGHTLY HIGHER GUSTS TO
25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING FOR MIZ004-
011.
FREEZE WARNING UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING FOR MIZ002-
009-010-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS DULUTH MN
916 PM CDT MON SEP 23 2013
.UPDATE...
ISSUED AT 915 PM CDT MON SEP 23 2013
ONLY SOME MINOR CHANGES WERE MADE TO THE GRIDS TONIGHT...WE MADE
SOME ADJUSTMENTS TO TEMPS BASED ON LATEST OBSERVATIONS...AND
TWEAKED SKY COVER AND WINDS. OTHERWISE...FORECAST WAS IN GOOD
SHAPE. WINDS HAVE DIMINISHED THIS EVENING...BUT REMAIN BRISK NOT
TOO FAR OFF THE SURFACE WHICH WILL LIMIT FOG POTENTIAL TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 330 PM CDT MON SEP 23 2013
CURRENT SAT IMAGERY SHOWS A WELL DEFINED VORT MAX/CLOSED LOW...AT THE
BASE OF A LONG WAVE TROUGH...ROTATING OVER NEBRASKA. THE LOW/TROUGH
WILL BEGIN TO FILL AS IT TRANSLATES EAST THROUGH TUESDAY. THE
REMNANTS OF THE H85/SFC TROUGH WILL PUSH EAST ACROSS WESTERN MN
TUESDAY MORNING...QUICKLY LOOSING STEAM AND DRYING OUT AS IT REACHES
NE MINN ZONES. HAVE KEPT MENTION OF AN ISOLATED SHOWER OVER NORTH-
CENTRAL MN ZONES TUESDAY AFTERNOON. HOWEVER...DUE TO LACK OF
MOISTURE SUSPECT MOST AREAS WILL ONLY SEE INCREASING CLOUDS WITH
THE FRONTAL PASSAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 PM CDT MON SEP 23 2013
MAJOR AMPLIFICATION OF ROCKIES MID LVL TROF WILL RESULT IN INCREASED
UPPER RIDGING OVER CTRL/WRN GT LAKES EARLY THIS PERIOD. THIS WILL
PRODUCE ABOVE NORMAL MAX TEMPS WITH DRY WX WED/THUR. LARGE SCALE
NATURE OF UPPER TROUGH AND FCST POSITIONING OF UPPER JET SUGGESTS
THAT CYCLOGENESIS WILL OCCUR WELL WEST OF REGION UNTIL FRIDAY. THIS
LEAVES A DEVELOPING WARM ADVECTION REGIME AS THE PRIMARY AGENT OF
FORCING FRIDAY. DPROG/DT ON EC/GFS HAVE SLOWED FORWARD PROGRESSION
OF DEEPER SATURATION/PRECIP. HAVE TRIMMED PREVIOUS SOLUTIONS
INCLUDING ALLBLEND FARTHER WEST. UPPER FCST BECOMES MORE COMPLICATED
BY FRIDAY EVENING AS MDLS SPLIT THE UPPER AIR INTO TWO DISTINCT
BRANCHES OF THE JET. THE PLACEMENT/INTERACTION OF THE TWO BRANCHES
DIFFER SIGNIFICANTLY AMONGST THE EC/GFS/GEM. ALL MDLS BRING
INCREASING POPS INTO REGION....HOWEVER TIMING IS QUITE DIFFERENT. EC
IS SLOWEST WITH GFS/GEN PUSHING PRECIP QUICKLY ACROSS CWA EARLIER IN
THE WEEKEND. A TREND TOWARDS INCREASING SFC HIGH PRESSURE AND FROPA
IS ESTABLISHED BY LATE SATURDAY WITH GRADUAL DIMINISHING OF PRECIP
SAT NIGHT IN MOST OF THE ERN CWA. POST FRONTAL REGIME MAY INDUCE
ADDITIONAL SHOWERS OVER NORTHWEST WISCONSIN SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 705 PM CDT MON SEP 23 2013
SURFACE WINDS HAVE DIMINISHED EARLY THIS EVENING...WITH HIGH
CLOUDS MOVING THROUGH. A LLJ WILL CREATE LLWS TONIGHT ACROSS MUCH
OF THE NORTHLAND THROUGH FROM ABOUT 05-06Z TO 12-13Z. DUE TO THE
DIMINISHING WINDS OBSERVED AT 00Z...CONFIDENCE HAS INCREASED IN
THE DEVELOPMENT OF LLWS.
WE KEPT THE MENTION OF SOME LOWER CLOUDS IN THE TAFS...AS SOME OF
THE GUIDANCE DOES SHOW SOME INDICATION THEY COULD DEVELOP LATE
TONIGHT. HOWEVER...LATEST RAP 925/900MB COND PRES DEFICITS ARE NOT
VERY SUPPORTIVE OF IT`S DEVELOPMENT...SO WE LIMITED THE MENTION TO
JUST SCT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 48 67 48 68 / 0 10 0 0
INL 51 70 46 74 / 10 20 10 0
BRD 52 70 48 75 / 10 20 10 0
HYR 44 73 45 72 / 0 10 0 0
ASX 46 70 46 70 / 0 10 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...MELDE
SHORT TERM...GRANING
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
706 PM CDT MON SEP 23 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 330 PM CDT MON SEP 23 2013
CURRENT SAT IMAGERY SHOWS A WELL DEFINED VORT MAX/CLOSED LOW...AT THE
BASE OF A LONG WAVE TROUGH...ROTATING OVER NEBRASKA. THE LOW/TROUGH
WILL BEGIN TO FILL AS IT TRANSLATES EAST THROUGH TUESDAY. THE
REMNANTS OF THE H85/SFC TROUGH WILL PUSH EAST ACROSS WESTERN MN
TUESDAY MORNING...QUICKLY LOOSING STEAM AND DRYING OUT AS IT REACHES
NE MINN ZONES. HAVE KEPT MENTION OF AN ISOLATED SHOWER OVER NORTH-
CENTRAL MN ZONES TUESDAY AFTERNOON. HOWEVER...DUE TO LACK OF
MOISTURE SUSPECT MOST AREAS WILL ONLY SEE INCREASING CLOUDS WITH
THE FRONTAL PASSAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 PM CDT MON SEP 23 2013
MAJOR AMPLIFICATION OF ROCKIES MID LVL TROF WILL RESULT IN INCREASED
UPPER RIDGING OVER CTRL/WRN GT LAKES EARLY THIS PERIOD. THIS WILL
PRODUCE ABOVE NORMAL MAX TEMPS WITH DRY WX WED/THUR. LARGE SCALE
NATURE OF UPPER TROUGH AND FCST POSITIONING OF UPPER JET SUGGESTS
THAT CYCLOGENESIS WILL OCCUR WELL WEST OF REGION UNTIL FRIDAY. THIS
LEAVES A DEVELOPING WARM ADVECTION REGIME AS THE PRIMARY AGENT OF
FORCING FRIDAY. DPROG/DT ON EC/GFS HAVE SLOWED FORWARD PROGRESSION
OF DEEPER SATURATION/PRECIP. HAVE TRIMMED PREVIOUS SOLUTIONS
INCLUDING ALLBLEND FARTHER WEST. UPPER FCST BECOMES MORE COMPLICATED
BY FRIDAY EVENING AS MDLS SPLIT THE UPPER AIR INTO TWO DISTINCT
BRANCHES OF THE JET. THE PLACEMENT/INTERACTION OF THE TWO BRANCHES
DIFFER SIGNIFICANTLY AMONGST THE EC/GFS/GEM. ALL MDLS BRING
INCREASING POPS INTO REGION....HOWEVER TIMING IS QUITE DIFFERENT. EC
IS SLOWEST WITH GFS/GEN PUSHING PRECIP QUICKLY ACROSS CWA EARLIER IN
THE WEEKEND. A TREND TOWARDS INCREASING SFC HIGH PRESSURE AND FROPA
IS ESTABLISHED BY LATE SATURDAY WITH GRADUAL DIMINISHING OF PRECIP
SAT NIGHT IN MOST OF THE ERN CWA. POST FRONTAL REGIME MAY INDUCE
ADDITIONAL SHOWERS OVER NORTHWEST WISCONSIN SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 705 PM CDT MON SEP 23 2013
SURFACE WINDS HAVE DIMINISHED EARLY THIS EVENING...WITH HIGH
CLOUDS MOVING THROUGH. A LLJ WILL CREATE LLWS TONIGHT ACROSS MUCH
OF THE NORTHLAND THROUGH FROM ABOUT 05-06Z TO 12-13Z. DUE TO THE
DIMINISHING WINDS OBSERVED AT 00Z...CONFIDENCE HAS INCREASED IN
THE DEVELOPMENT OF LLWS.
WE KEPT THE MENTION OF SOME LOWER CLOUDS IN THE TAFS...AS SOME OF
THE GUIDANCE DOES SHOW SOME INDICATION THEY COULD DEVELOP LATE
TONIGHT. HOWEVER...LATEST RAP 925/900MB COND PRES DEFICITS ARE NOT
VERY SUPPORTIVE OF IT`S DEVELOPMENT...SO WE LIMITED THE MENTION TO
JUST SCT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 51 67 48 68 / 0 10 0 0
INL 51 70 46 74 / 10 20 10 0
BRD 54 70 48 75 / 10 20 10 0
HYR 47 73 45 72 / 0 10 0 0
ASX 48 70 46 70 / 0 10 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GRANING
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
658 PM EDT SUN SEP 22 2013
.SYNOPSIS...
LAKE EFFECT SHOWERS WILL DISSIPATE THIS EVENING. OVERNIGHT LOWS
WILL DROP INTO THE 30S AND MAY ALLOW PATCHY FROST TO DEVELOP IN
THE CENTRAL SOUTHERN TIER AND WESTERN CATSKILLS OF NEW YORK. HIGH
PRESSURE WILL BUILD IN TOMORROW AND ALLOW AREAS OF FROST TO
DEVELOP ON TUESDAY MORNING. DRY WEATHER WILL BE IN PLACE INTO NEXT
WEEKEND WITH MODERATING TEMPERATURES.
&&
.NEAR TERM /THROUGH MONDAY/...
7 PM UPDATE...LATEST SATELLITE PICS SHOW STRATO CU HOLDING TUFF
ACROSS THE CWA. LATEST RAP SOUNDINGS SUGGEST MOSTLY CLOUDY SKIES
FOR MUCH OF THE FA OVERNIGHT WHILE THE NAM WOULD INDICATE SKIES
BECOMING PARTLY CLOUDY TO MAINLY CLEAR. LOW LEVEL FLOW IS EXPECTED
TO VEER OVERNIGHT TO A N/NNW DIRECTION. LAKE/T85 DIFFERENTIAL
ENOUGH TO SUPPORT LAKE CLOUDS, CURRENT THINKING IS MUCH OF THE AREA
WILL GRADUALLY BECOME PARTLY CLOUDY DURING THE EVENING WITH THE
MOST PERSISTENT CLOUDS ACROSS THE FINGER LAKES REGION INTO THE
CENTRAL SOUTHERN TIER DUE TO LOW LEVEL FLOW. ONLY ADJUSTMENT WAS
TO INCREASE CLOUD COVER INTO THE EARLY EVENING HOURS.
2 PM UPDATE...
LK EFFECT SHOWERS WL GRADUALLY WIND DOWN TONIGHT AS VORT MAX EXITS
THE CWA AND DRY AIR WORKS IN AFT MIDNIGHT. FAVORED LK REGIONS WL SEE
JUST ISOLD SHOWERS THRU ABOUT 03Z BFR DIMINISHING ALTOGETHER. CLOUDS
WL BEGIN TO VRY SLOWLY DECREASE AFT THIS TIME, ALLOWING TEMPS TO
FALL INTO THE 30S. CLDR VLY LOCATIONS IN THE CNTRL SRN TIER,
SUSQUEHANNA REGION AND THE WRN CATS MAY SEE PATCHY FROST TONIGHT AS
TEMPS PROGGED TO DROP TO 37F OR LWR. THAT IS, ASSUMING NO FOG DVLPS
TONIGHT. HV NOT ADDED IN PATCHY RVR VLY FOG TO THE GRIDS AT THIS
TIME AS WINDS SHUD STAY UP IN BL ARND 15KTS BUT CANNOT RULE OUT SOME
PATCHY DENSE FOG IN LOWEST VLY AREAS ARND ELMIRA AND SIDNEY. IF THAT
HAPPENS, PATCHY FROST WL BE INHIBITED IN THESE AREAS.
N-NW FLOW WL CONTINUE THRU THE DAY TOMORROW AS 1020MB HIPRES BEGINS
TO BUILD EAST. BL PROGGED TO DRY OUT AFT 18Z WITH MOSTLY-PARTLY SUNNY
SKIES EXPECTED THRU MRNG AS STRATOCU STARTS TO ERODE FM THE EDGES.
GFS H8 RH FIELDS EMULATING CLR SKIES UP NORTH OF LK SUPERIOR AT
PRESENT AND SLOWLY WORKS SOUTH AND EAST THRU 18Z MONDAY. HWVR, WL
NOT BE SO QUICK TO GO CLR DUE TO INFLUENCE OF LAKES AND WL KEEP
PCLDY CONDS THRU MID-MORNING THEN BEGIN CLRNG AFT 16Z AS UL RIDGE
BEGINS TO BUILD IN.
AFTN MAXES WILL TOP OUT ARND 60 ON MONDAY AND WITH MORE SUN EXPECTED
THAN TDA, WINDS SHUD GUST TO BTWN 15-20KTS DRG THE DAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
2 PM UPDATE...
TEMPS ON MON NGT WL QUICKLY FALL OFF UNDER CLR SKIES AND LGT WINDS
DUE TO SFC HIPRES GETTING EVER CLOSER. OVRNGT LOWS EXPECTED TO DROP
TO ARND FRZG IN NOTORIOUSLY CLD LOCATIONS OF SRN TIER AND WRN CATS.
HV ALLOWED FOR PATCHY FROST IN AREAS THAT DROP TO 37F AND AREAS OF
FROST BLO 34F. WL PASS ON TO MIDNIGHT SHIFT ABOUT POSSIBLE FREEZE
WATCH FOR TUE MRNG AND WL CONTINUE TO HIGHLIGHT THREAT IN HWO.
HIPRES RMNS OVR THE AREA THRU THE END OF THE SHORT TERM WITH HIGHS
ON TUE EXPECTED TO CLIMB INTO THE 60S AND LOWS IN THE U30S/ARND 40.
AVG TEMPS DRG THIS TIME WL RUN SLIGHTLY BLO NORMAL DUE TO OVRNGT
LOWS.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
130 PM EDT UPDATE...
MINOR ADJUSTMENTS WERE MADE TO THE PREVIOUS FCST AS THE CURRENT
FORECAST APPEARS TO REMAIN DRY. FORECAST ON TRACK WITH STRONG SFC
HIGH BUILDING OVER THE REGION. AND THE NEXT CHANCE FOR SHOWERS AND
THUNDERSTORMS BEING ON SUNDAY WITH ANOTHER APPROACHING STORM
SYSTEM.
230 AM UPDATE...
CURRENT FCST IN GOOD SHAPE...NO CHANGES NEEDED THIS MORNING.
MODEL GUIDANCE CONTINUING TO SUGGEST A FAIRLY DRY PERIOD FOR THE
UPCOMING WEEK AS HIGH PRESSURE REMAINS IN CONTROL. BY LATE
WEEK...EXPECT MODERATING TEMPS AS WARM AIR ADVECTION INCREASES IN
ADVANCE OF THE NEXT STORM SYSTEM PROGGED TO ARRIVE TOWARDS THE END
OF THE WEEKEND. IF CURRENT MODEL TRENDS HOLD TRUE...TEMPS BY NEXT
WEEKEND MAY WARM BACK UP INTO THE LOWER TO MIDDLE 70S FOR DAYTIME
HIGHS. STAY TUNED!
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
130 PM EDT UPDATE...
MVFR AND IFR CIGS CONTINUE TO PREVAIL ACROSS CENTRAL NEW YORK AND
NORTHEAST PENNSYLVANIA THIS AFTERNOON. VERY LIGHT RAIN SHOWERS ARE
ALSO MOVING SE AND EXPECT THESE TO CONTINUE THROUGH 00Z. EMBEDDED
IFR CIGS WITH IFR VSBYS ARE POSSIBLE WITH THESE SHOWERS. CLOUD
COVERAGE THIS AFTERNOON HAS BEEN VERY POTENT WHICH HAS KEPT WIND
GUSTS DOWN... HOWEVER SITES WHERE SUNSHINE MAKING ITS WAY THROUGH
THE DECK WILL SEE GUSTS NEAR 25 KNOTS. THE CLOUDS WILL SLOWLY
DIMINISH AND BECOME VFR BY THIS EVENING.
TONIGHT IS STILL A QUESTIONABLE FORECAST. CLOUD COVERAGE IS
EXPECTED TO DISSIPATE BUT THE QUESTION IS BY HOW MUCH. IF SKIES
CLEAR OUT DENSE FOG IS LIKELY AT KELM WITH IFR VSBYS BUT... IF THE
STRATUS STAYS STUBBORN THEN VSBYS WITH THE FOG MAY REMAIN MVFR.
ALSO... IFR CIGS MAY DEVELOP LATE TOMORROW MORNING FOR MUCH OF THE
AREA BUT CONFIDENCE IS LOW THUS KEPT IFR CIGS AS A TEMPO FOR NOW.
OUTLOOK...
MON-FRI...MAINLY VFR. LATE NIGHT/EARLY MORNING VALLEY FOG POSSIBLE
ESPECIALLY KELM.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN/RRM
SHORT TERM...PVN
LONG TERM...CMG/KAH
AVIATION...KAH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
245 PM EDT SUN SEP 22 2013
.SYNOPSIS...
THE COLD FRONT THAT MOVED THROUGH THE REGION EARLY THIS MORNING HAS
MOVED. HIGH PRESSURE WILL BUILD INTO THE REGION AND PERSIST THROUGH
LATE TUESDAY. THE NEXT STORM SYSTEM WILL APPROACH THE AREA ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 PM SUNDAY...
LATEST SURFACE ANALYSIS SHOWS A COLD FRONT AND A WEAK AREA OF LOW
PRESSURE MOVING AWAY FROM THE NC COAST WITH AN AREA OF HIGH PRESSURE
CENTERED OVER THE WESTERN GREAT LAKES. DEEP LAYER MOISTURE LOCATED
OVER THE COASTAL REGION GRADUALLY THINS ACROSS THE COASTAL PLAIN AND
ESPECIALLY THE EASTERN PIEDMONT. A 1708Z AMADAR AIRCRAFT SOUNDING AT
KRDU SHOWS A VERY SHALLOW LAYER OF MOISTURE TRAPPED BELOW THE
INVERSION. VISIBLE SATELLITE IMAGERY SUGGESTS THAT THE
STRATO-CUMULUS ACROSS THE WESTERN PERIPHERY OF THE MAIN CLOUD SHIELD
AND ACROSS THE NORTHERN PIEDMONT IS BEGINNING TO WANE AS THE
MOISTURE BEGINS TO MIX OUT. NWP GUIDANCE SUGGEST THAT THIS WILL BE
THE CASE INTO THE EVENING HOURS. NWP GUIDANCE...ESPECIALLY THE NAM
AND RAP SUGGEST THAT A SHALLOW LAYER OF MOISTURE WILL SPREAD INTO
THE WESTERN PIEDMONT OVERNIGHT AND WILL LIKELY RESULT IN SOME
STRATUS OVERNIGHT. IN FACT...A FEW OF THE SREF MEMBERS ACTUALLY SPIT
OUT A LITTLE PRECIP AT KGSO AND KROA. WILL KEEP THE FORECAST DRY AND
INCLUDE PARTLY CLOUDY SKIES IN THE TRIAD REGION OVERNIGHT. BOUNDARY
LAYER PROFILERS AT BOTH CLAYTON AND RESEARCH TRIANGLE PARK THIS
AFTERNOON NOTE THE STRONGER NORTHEAST FLOW BETWEEN 2-4KFT EARLIER
TODAY HAS WEAKENED SOMEWHAT DURING THE PAST FEW HOURS AND THIS
SHOULD ALLOW THE WIND GUSTS TO RELAX DURING THE NEXT FEW HOURS.
WHILE GUSTS WILL LINGER LONGER TO THE EAST IN THE COASTAL PLAIN MOST
LOCATIONS WILL SEE A LIGHT NORTHEAST WIND OVERNIGHT WHICH WILL
MITIGATE FOG DEVELOPMENT. MINIMUM TEMPERATURE GUIDANCE FOR TONIGHT
HAS GENERALLY TRENDED DOWNWARD DURING THE PAST DAY OR TWO. WILL
FORECAST LOWS IN THE UPPER 40S IN THE NE PIEDMONT AND N COASTAL
PLAIN WITH LOWS IN THE LOWER 50S ELSEWHERE INCLUDING THE TRIAD WHERE
CLOUDS AND A STIRRING WIND KEEPS TEMPERATURES ELEVATED. -BLAES
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 245 PM SUNDAY...
FAIR WEATHER WITH SLIGHTLY BELOW SEASONABLE TEMPERATURES IS EXPECTED
FOR MONDAY AND MONDAY NIGHT. HIGH PRESSURE CENTERED OVER THE EASTERN
GREAT LAKES WILL GRADUALLY SHIFT SOUTHEAST AND RIDGE INTO THE
CAROLINAS AND VIRGINIA AS A SHORT WAVE RIDGE OF HIGH PRESSURE BUILDS
EAST. SOME RESIDUAL LOW LEVEL MOISTURE WILL RESULT IN A FEW CUMULUS
CLOUDS DURING THE AFTERNOON ACROSS THE REGION AND SOME PATCHY
STRATUS ACROSS THE WESTERN PIEDMONT ON MONDAY NIGHT. HIGHS MONDAY
WILL RANGE IN THE 71-78 RANGE...COOLEST IN THE NORTHEAST. CHILLY
LOWS IN THE 47-54 RANGE ARE EXPECTED TUESDAY MORNING. -BLAES
&&
.LONG TERM /TUESDAY THROUGH SUNDAY...
AS OF 235 PM SUNDAY...
A FAIRLY DRY PERIOD IS EXPECTED FOR MOST OF THE LONG TERM WITH THE
EXCEPTION BEING SOME LIGHT STRATIFORM RAIN ASSOCIATED WITH A
SHORTWAVE LOW COMING OUT OF THE GULF OF MEXICO AND TRACKING ACROSS
THE DEEP SOUTH. SEASONAL MAXIMUM TEMPERATURES FROM THE MID 70S TO
NEAR 80S ARE EXPECTED FOR THE DURATION OF THE LONG TERM. LOWS WILL
GENERALLY RANGE FROM THE LOW TO UPPER 50S...NEAR OR SLIGHTLY BELOW
NORMAL FOR THIS TIME OF YEAR.
FOR TUESDAY...SURFACE HIGH WILL EXTEND INTO THE CAROLINAS FROM
SOUTHERN CANADA WITH A VERY SHARP UPPER LEVEL RIDGE ACROSS THE AREA.
EXPECT CLOUD COVER TO INCREASE LATE IN THE DAY FROM SOUTHWEST TO
NORTHEAST AS MOISTURE BEGINS TO BE ADVECTED NORTHWARD AHEAD OF THE
LOW.
ON WEDNESDAY AND THURSDAY THE LOW TO THE SOUTHWEST WILL BEGIN TO
DEEPEN WITH THE GFS COMING INTO BETTER AGREEMENT WITH THE ECMWF AND
BOTH MODELS NOW OPENING UP THE GULF OF MEXICO TO NORTHWARD MOISTURE
TRANSPORT. THE TIMING IS STILL A BIT OFF WITH THE ECMWF MORE
AGGRESSIVELY DEEPENING THE LOW AND MORE PROGRESSIVE WITH THE TIMING.
WILL STILL MORE CLOSELY FOLLOW THE ECMWF AND FORECASTED POPS AND
CLOUD COVER WILL ILLUSTRATE THIS...BRINGING CHANCE POPS INTO THE
SOUTH AND WEST ON WEDNESDAY AFTERNOON THROUGH TUESDAY MORNING. WILL
LEAVE SOME ROOM FOR THE POSSIBILITY OF THE GFS SOLUTION AND KEEP
SLIGHT CHANCE POPS THROUGH THURSDAY AFTERNOON. EXPECT RAIN TO BE
LIGHT AND STRATIFORM IN NATURE ALTHOUGH GFS FORECAST SOUNDINGS DO
HINT AT AN ELEVATED MIXED LAYER ABOVE A VERY STRONG CAP AT 950 MB.
ONE DIFFERENCE MAKER COULD BE A MUCH SMALLER SHORTWAVE IMPULSE IN
THE NORTHERN STREAM TRACKING THROUGH THE OHIO VALLEY. SLOWER GFS
TIMING ALLOWS THIS FEATURE TO INTERACT MORE WITH MOISTURE FROM THE
SOUTHERN STREAM AND TRACK ACROSS SOUTHERN VA. FOR NOW...WILL LEAVE
THE DETAILS OF THIS TO THE DAYS AHEAD.
AFTER THE LOW EXITS OFF OF THE COAST ON THURSDAY NIGHT...THINGS WILL
DRY OUT CONSIDERABLY FOR THE REST OF THE LONG TERM. A STRONG UPPER
LEVEL RIDGE WILL DOMINATE THE EASTERN CONUS ALONG WITH SURFACE HIGH
PRESSURE EXTENDING DOWN THE EAST COAST.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 200 PM SUNDAY...
LATEST OBSERVATIONS SHOW FAIRLY WIDESPREAD STRATUS WITH MVFR/VFR
CEILINGS ACROSS THE COASTAL PLAIN SITES (KFAY AND KRWI) WITH SCT-BKN
VFR STRATOCUMULUS ELSEWHERE. MODEL GUIDANCE SUGGESTS THE LOW STRATUS
IN THE EAST WILL GRADUALLY THIN THIS EVENING RESULTING IN VFR
CONDITIONS IN SCT STRATUS OVERNIGHT. FURTHER WEST...RESIDUAL CLOUDS
ENHANCED BY DAYTIME HEATING WILL THIN INITIALLY THIS EVENING WITH
SOME OF THE GUIDANCE IS DEPICTING ANOTHER AREA OF STRATUS DEVELOPING
AND MOVING INTO THE TRIAD TAF SITES (KINT AND KGSO) OVERNIGHT WITH
VFR CEILINGS. VFR CONDITIONS ARE EXPECTED TO DOMINATE ON MONDAY WITH
PERIODS OF SCT CUMULUS AT AROUND 4-5KFT. NORTHEAST WINDS AT 10-15
KTS WITH GUSTS AT TIMES EXCEEDING 22KTS THIS AFTERNOON WILL BECOME
LESS GUSTY TONIGHT BUT REMAIN BLOWING AT 5-10KTS OVERNIGHT. AS A
HIGH PRESSURE RIDGE BUILDS INTO THE REGION...WINDS WILL RELAX ON
MONDAY AFTERNOON AND BECOME NORTHEAST TO EASTERLY.
LOOKING BEYOND 18Z MONDAY... VFR CONDITIONS WILL PERSIST ON MONDAY
THROUGH EARLY WEDNESDAY ALTHOUGH SOME STRATUS WITH VFR CEILINGS MAY
DEVELOP MONDAY NIGHT AND TUESDAY NIGHT IN THE WESTERN PIEDMONT. THE
NEXT STORM SYSTEM WILL APPROACH THE REGION FROM THE SOUTHWEST ON
WEDNESDAY INTO THURSDAY WITH A CHANCE OF ADVERSE AVIATION
CONDITIONS...ESPECIALLY ACROSS THE SOUTH. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...ELLIS
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
247 PM EDT SUN SEP 22 2013
.SYNOPSIS...
THE COLD FRONT THAT MOVED THROUGH THE REGION EARLY THIS MORNING HAS
MOVED. HIGH PRESSURE WILL BUILD INTO THE REGION AND PERSIST THROUGH
LATE TUESDAY. THE NEXT STORM SYSTEM WILL APPROACH THE AREA ON
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 245 PM SUNDAY...
LATEST SURFACE ANALYSIS SHOWS A COLD FRONT AND A WEAK AREA OF LOW
PRESSURE MOVING AWAY FROM THE NC COAST WITH AN AREA OF HIGH PRESSURE
CENTERED OVER THE WESTERN GREAT LAKES. DEEP LAYER MOISTURE LOCATED
OVER THE COASTAL REGION GRADUALLY THINS ACROSS THE COASTAL PLAIN AND
ESPECIALLY THE EASTERN PIEDMONT. A 1708Z AMADAR AIRCRAFT SOUNDING AT
KRDU SHOWS A VERY SHALLOW LAYER OF MOISTURE TRAPPED BELOW THE
INVERSION. VISIBLE SATELLITE IMAGERY SUGGESTS THAT THE
STRATO-CUMULUS ACROSS THE WESTERN PERIPHERY OF THE MAIN CLOUD SHIELD
AND ACROSS THE NORTHERN PIEDMONT IS BEGINNING TO WANE AS THE
MOISTURE BEGINS TO MIX OUT. NWP GUIDANCE SUGGEST THAT THIS WILL BE
THE CASE INTO THE EVENING HOURS. NWP GUIDANCE...ESPECIALLY THE NAM
AND RAP SUGGEST THAT A SHALLOW LAYER OF MOISTURE WILL SPREAD INTO
THE WESTERN PIEDMONT OVERNIGHT AND WILL LIKELY RESULT IN SOME
STRATUS OVERNIGHT. IN FACT...A FEW OF THE SREF MEMBERS ACTUALLY SPIT
OUT A LITTLE PRECIP AT KGSO AND KROA. WILL KEEP THE FORECAST DRY AND
INCLUDE PARTLY CLOUDY SKIES IN THE TRIAD REGION OVERNIGHT. BOUNDARY
LAYER PROFILERS AT BOTH CLAYTON AND RESEARCH TRIANGLE PARK THIS
AFTERNOON NOTE THE STRONGER NORTHEAST FLOW BETWEEN 2-4KFT EARLIER
TODAY HAS WEAKENED SOMEWHAT DURING THE PAST FEW HOURS AND THIS
SHOULD ALLOW THE WIND GUSTS TO RELAX DURING THE NEXT FEW HOURS.
WHILE GUSTS WILL LINGER LONGER TO THE EAST IN THE COASTAL PLAIN MOST
LOCATIONS WILL SEE A LIGHT NORTHEAST WIND OVERNIGHT WHICH WILL
MITIGATE FOG DEVELOPMENT. MINIMUM TEMPERATURE GUIDANCE FOR TONIGHT
HAS GENERALLY TRENDED DOWNWARD DURING THE PAST DAY OR TWO. WILL
FORECAST LOWS IN THE UPPER 40S IN THE NE PIEDMONT AND N COASTAL
PLAIN WITH LOWS IN THE LOWER 50S ELSEWHERE INCLUDING THE TRIAD WHERE
CLOUDS AND A STIRRING WIND KEEPS TEMPERATURES ELEVATED. -BLAES
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 245 PM SUNDAY...
FAIR WEATHER WITH SLIGHTLY BELOW SEASONABLE TEMPERATURES IS EXPECTED
FOR MONDAY AND MONDAY NIGHT. HIGH PRESSURE CENTERED OVER THE EASTERN
GREAT LAKES WILL GRADUALLY SHIFT SOUTHEAST AND RIDGE INTO THE
CAROLINAS AND VIRGINIA AS A SHORT WAVE RIDGE OF HIGH PRESSURE BUILDS
EAST. SOME RESIDUAL LOW LEVEL MOISTURE WILL RESULT IN A FEW CUMULUS
CLOUDS DURING THE AFTERNOON ACROSS THE REGION AND SOME PATCHY
STRATUS ACROSS THE WESTERN PIEDMONT ON MONDAY NIGHT. HIGHS MONDAY
WILL RANGE IN THE 71-78 RANGE...COOLEST IN THE NORTHEAST. CHILLY
LOWS IN THE 47-54 RANGE ARE EXPECTED TUESDAY MORNING. -BLAES
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 235 PM SUNDAY...
A FAIRLY DRY PERIOD IS EXPECTED FOR MOST OF THE LONG TERM WITH THE
EXCEPTION BEING SOME LIGHT STRATIFORM RAIN ASSOCIATED WITH A
SHORTWAVE LOW COMING OUT OF THE GULF OF MEXICO AND TRACKING ACROSS
THE DEEP SOUTH. SEASONAL MAXIMUM TEMPERATURES FROM THE MID 70S TO
NEAR 80S ARE EXPECTED FOR THE DURATION OF THE LONG TERM. LOWS WILL
GENERALLY RANGE FROM THE LOW TO UPPER 50S...NEAR OR SLIGHTLY BELOW
NORMAL FOR THIS TIME OF YEAR.
FOR TUESDAY...SURFACE HIGH WILL EXTEND INTO THE CAROLINAS FROM
SOUTHERN CANADA WITH A VERY SHARP UPPER LEVEL RIDGE ACROSS THE AREA.
EXPECT CLOUD COVER TO INCREASE LATE IN THE DAY FROM SOUTHWEST TO
NORTHEAST AS MOISTURE BEGINS TO BE ADVECTED NORTHWARD AHEAD OF THE
LOW.
ON WEDNESDAY AND THURSDAY THE LOW TO THE SOUTHWEST WILL BEGIN TO
DEEPEN WITH THE GFS COMING INTO BETTER AGREEMENT WITH THE ECMWF AND
BOTH MODELS NOW OPENING UP THE GULF OF MEXICO TO NORTHWARD MOISTURE
TRANSPORT. THE TIMING IS STILL A BIT OFF WITH THE ECMWF MORE
AGGRESSIVELY DEEPENING THE LOW AND MORE PROGRESSIVE WITH THE TIMING.
WILL STILL MORE CLOSELY FOLLOW THE ECMWF AND FORECASTED POPS AND
CLOUD COVER WILL ILLUSTRATE THIS...BRINGING CHANCE POPS INTO THE
SOUTH AND WEST ON WEDNESDAY AFTERNOON THROUGH TUESDAY MORNING. WILL
LEAVE SOME ROOM FOR THE POSSIBILITY OF THE GFS SOLUTION AND KEEP
SLIGHT CHANCE POPS THROUGH THURSDAY AFTERNOON. EXPECT RAIN TO BE
LIGHT AND STRATIFORM IN NATURE ALTHOUGH GFS FORECAST SOUNDINGS DO
HINT AT AN ELEVATED MIXED LAYER ABOVE A VERY STRONG CAP AT 950 MB.
ONE DIFFERENCE MAKER COULD BE A MUCH SMALLER SHORTWAVE IMPULSE IN
THE NORTHERN STREAM TRACKING THROUGH THE OHIO VALLEY. SLOWER GFS
TIMING ALLOWS THIS FEATURE TO INTERACT MORE WITH MOISTURE FROM THE
SOUTHERN STREAM AND TRACK ACROSS SOUTHERN VA. FOR NOW...WILL LEAVE
THE DETAILS OF THIS TO THE DAYS AHEAD.
AFTER THE LOW EXITS OFF OF THE COAST ON THURSDAY NIGHT...THINGS WILL
DRY OUT CONSIDERABLY FOR THE REST OF THE LONG TERM. A STRONG UPPER
LEVEL RIDGE WILL DOMINATE THE EASTERN CONUS ALONG WITH SURFACE HIGH
PRESSURE EXTENDING DOWN THE EAST COAST.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
AS OF 200 PM SUNDAY...
LATEST OBSERVATIONS SHOW FAIRLY WIDESPREAD STRATUS WITH MVFR/VFR
CEILINGS ACROSS THE COASTAL PLAIN SITES (KFAY AND KRWI) WITH SCT-BKN
VFR STRATOCUMULUS ELSEWHERE. MODEL GUIDANCE SUGGESTS THE LOW STRATUS
IN THE EAST WILL GRADUALLY THIN THIS EVENING RESULTING IN VFR
CONDITIONS IN SCT STRATUS OVERNIGHT. FURTHER WEST...RESIDUAL CLOUDS
ENHANCED BY DAYTIME HEATING WILL THIN INITIALLY THIS EVENING WITH
SOME OF THE GUIDANCE IS DEPICTING ANOTHER AREA OF STRATUS DEVELOPING
AND MOVING INTO THE TRIAD TAF SITES (KINT AND KGSO) OVERNIGHT WITH
VFR CEILINGS. VFR CONDITIONS ARE EXPECTED TO DOMINATE ON MONDAY WITH
PERIODS OF SCT CUMULUS AT AROUND 4-5KFT. NORTHEAST WINDS AT 10-15
KTS WITH GUSTS AT TIMES EXCEEDING 22KTS THIS AFTERNOON WILL BECOME
LESS GUSTY TONIGHT BUT REMAIN BLOWING AT 5-10KTS OVERNIGHT. AS A
HIGH PRESSURE RIDGE BUILDS INTO THE REGION...WINDS WILL RELAX ON
MONDAY AFTERNOON AND BECOME NORTHEAST TO EASTERLY.
LOOKING BEYOND 18Z MONDAY... VFR CONDITIONS WILL PERSIST ON MONDAY
THROUGH EARLY WEDNESDAY ALTHOUGH SOME STRATUS WITH VFR CEILINGS MAY
DEVELOP MONDAY NIGHT AND TUESDAY NIGHT IN THE WESTERN PIEDMONT. THE
NEXT STORM SYSTEM WILL APPROACH THE REGION FROM THE SOUTHWEST ON
WEDNESDAY INTO THURSDAY WITH A CHANCE OF ADVERSE AVIATION
CONDITIONS...ESPECIALLY ACROSS THE SOUTH. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...RE
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1212 AM EDT SUN SEP 22 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT AND CROSS THE
REGION SUNDAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTH EARLY NEXT
WEEK. LOW PRESSURE WILL PASS SOUTH OF THE REGION WEDNESDAY WITH HIGH
PRESSURE RETURNING LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1205 AM SUNDAY...SO FAR ONLY VERY LIGHT RAIN HAS SPREAD OVER
ERN NC. RGNL RDRS SHOW MORE WIDESPREAD AND HEAVIER PRECIP TO THE W
MAINLY JUST NE OF SFC LOW ON COLD FRONT. MDLS SHOW THIS LOW TRACKING
E TWRD CST OVERNIGHT SO WIDESPREAD RAIN WILL OVERSPREAD REGION.
ALTHOUGH INSTAB IS VERY WEAK MAY BE JUST ENOUGH FOR ONE OR TWO
LIGHTNING STRIKES SO INCLUDED SLIGHT CHC TSRA. BASED ON RDR TRENDS
THINK HEAVIEST RAINFALL WILL BE OVER NRN TIER BUT ALL AREAS SHLD SEE
DECENT RAINFALL AND WILL CONT CAT POPS. MILD TEMPS WITH AREA
REMAINING ON WARM SIDE OF COLD FRONT...LOWS MAINLY UPR 60S TO LOWER
70S.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AS OF 300 PM SAT...MODELS INDICATE SLIGHTLY SLOWER FRONTAL
PROGRESSION WITH NAM AND ECMWF INDICATING STRONGER SFC WAVE ON SRN
END. HAVE ADJUSTED FCST SLIGHTLY TOWARD THIS SOLUTION WITH HIGHER
POPS LINGERING ALONG COAST THROUGH MORNING...DIMINISHING W TO E
DURING AFTN. MOS BLEND FOR TEMPS WITH PCPN AND CLOUD COVER EXPECTED
TO HOLD MAX TEMPS IN MID TO UPR 70S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
ANY LINGERING PRECIP WILL GRADUALLY BE MOVING OFF THE COAST SUNDAY
NIGHT, WITH COOLER/DRIER AIR FILTERING INTO THE REGION VIA SFC
HIGH PRES RIDGING SOUTH FROM THE GREAT LAKES AND DEVELOPING NW
FLOW ALOFT. LOWS WILL DIP INTO THE MID 50S INLAND BY EARLY MON
MORNING AND LOW TO MID 60S COAST UNDER GRADUALLY CLEARING SKIES.
PLEASANT WEATHER CONDITIONS WILL HIGHLIGHT THE EARLY WEEK PERIOD WITH
SFC HIGH AND UPPER RIDGE BUILDING OVER THE AREA. TEMPS WILL BE A
BIT BLO NORMAL WITH GOOD RADIATIONAL COOLING AT NIGHT, BUT WITH
LOTS OF SUNSHINE BOTH MONDAY AND TUESDAY
MODEL SOLUTIONS CONTINUE TO VARY WITH A SYSTEM (OR LACK THEREOF)
MOVING OFF THE SE COAST DURING MIDWEEK. WILL CONTINUE TO FOLLOW
WPC RECOMMENDATIONS FOR A BLEND OF ENSEMBLE MEANS WHICH MORE
CLOSELY FOLLOW THE DETERMINISTIC ECMWF SOLUTION, JUST NOT AS
AMPLIFIED. SO WITH THAT IN MIND WILL KEEP POPS AT SLIGHT TO LOW
THRU MIDWEEK AND FAVOR SOUTHERN AREAS FOR THE HIGHER PRECIP
CHANCES. CLOUD COVER SPREADING NORTH ON THE FRINGES OF THE
SOUTHERN SYSTEM WILL HELP HOLD HIGH TEMPS IN THE 70S ON
WEDNESDAY.
PRECIP CHANCES LINGER THRU WED NIGHT AND INTO EARLY THU ESPECIALLY
ALONG SE COASTAL AREAS. SHUD BEGIN TO SEE DECREASING CLOUDS THU
AFTN AS SFC LOW PRES MOVES WELL OFF THE SE COAST AND MID LEVEL
DRYING SWEEPS THRU THE FCST AREA. RIDGING AT THE SURFACE AND ALOFT
ENSURES DRY WEATHER RETURNING TO THE REGION LATE IN THE WEEK.
TEMPS WILL TREND BACK TO NEAR AND ABOVE NORMAL LEVELS INTO EARLY
NEXT WEEKEND.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH SUNDAY/...
AS OF 1205 AM SUNDAY...WIDESPREAD RAIN WILL OVERSPREAD REGION NEXT
SEVERAL HRS. AS THIS RAIN REACHES AREA EXPECT MAINLY MVFR VSBYS WITH
CIGS GRAD LOWERING TO IFR...MAY DELAY IFR CIGS A BIT BASED ON
UPSTREAM OBS. RAIN AND LOW CIGS WILL CONT INTO SUN MORN THEN SHLD
SEE PRECIP END WITH CIGS GRAD IMPROVING TO MVFR BY MIDDAY AND POSS
VFR LATE.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
POOR FLYING CONDITIONS SUNDAY EVENING WILL GRADUALLY IMPROVE THRU
EARLY MONDAY MORNING AS DRIER AIR WORKS INTO THE AREA. OTHER THAN
THE TYPICAL THREAT FOR SHALLOW EARLY MORNING FOG...GOOD FLYING
WEATHER EXPECTED MONDAY/TUESDAY WITH HIGH PRESSURE BUILDING INTO
THE AREA. WILL BEGIN TO SEE INCREASING CLOUDS, RAIN CHANCES AND
THREAT FOR SUB-VFR CONDITIONS WEDNESDAY INTO WED NIGHT AS LOW
PRESSURE MOVES SOUTH OF THE AREA. EXPECTED IMPROVING FLYING
CONDITIONS ON TUESDAY AS HIGH PRESSURE RETURNS.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY/...
AS OF 1205 AM SUN...PER LATEST 3KM HRRR AND RUC MODELS...EXPECT THE
CURRENT SOUTHERLY WINDS AT 10 TO 15 KNOTS TO BECOME SW LATE TONIGHT.
SPEEDS MAY INCREASE TO 15 TO 20 KNOTS OVER THE SOUTHERN WATERS AND
SURFACE LOW TRACKS INLAND LATE TONIGHT. SEAS SHOULD REMAIN RIGHT
AROUND 3 FEET WITH 10 SECOND SWELL PERIODS. ADJUSTED WINDS FOR
SLIGHTLY SLOWER FRONTAL/SFC LOW PASSAGE ON SUNDAY. EXPECT MAINLY
S/SE WINDS THRU SUN MORN WITH DIR BECOMING NE LATE AND INCREASING TO
15 TO 20 KTS MOST WTRS BY EVENING.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
CAA SURGE WILL PUSH NORTH WINDS AND SEAS TO NEAR SMALL CRAFT
ADVISORY LEVELS SUNDAY NIGHT INTO EARLY MONDAY. WINDS WILL THEN
GRADUALLY DIMINISH AND VEER TO THE NE/E AND SEAS SLOWLY SUBSIDE AS
HIGH PRESSURE BUILDS INTO THE MARINE AREA FROM THE NORTH THRU
TUESDAY. WINDS WILL BACK AGAIN TO THE NE/N AND INCREASE AS LOW
PRESSURE PASSES TO THE SOUTH WED NIGHT AND THURSDAY BUT NOT
EXPECTING ANY FLAGS WILL BE NEEDED.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JBM
NEAR TERM...RF
SHORT TERM...JBM
LONG TERM...BTC
AVIATION...RF/BM
MARINE...RF/CTC/BTC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1236 PM CDT SUN SEP 22 2013
.UPDATE...
ISSUED AT 1236 PM CDT SUN SEP 22 2013
UPDATED TO ADD AVIATION SECTION BELOW.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MAIN CHALLENGES WILL BE TEMPERATURES TODAY AND PRECIP CHANCES
TONIGHT INTO MONDAY. 00Z MODELS ARE IN DECENT AGREEMENT THROUGH
THIS PERIOD AND WILL USE A BLEND FOR DETAILS. 500MB LOW WILL
PROPAGATE FROM THE SOUTHWEST CONUS INTO THE CENTRAL PLAINS. THIS
WILL DEVELOP SOUTHWEST FLOW ALOFT BY TONIGHT...CONTINUING INTO
MONDAY. ALTHOUGH LOW LEVEL FLOW WILL SIGNIFICANTLY INCREASE...IT
WILL BE FROM MORE OF A SOUTHEAST DIRECTION...PROMOTING THE VERY
DRY LOW LEVEL AIRMASS. THIS WILL BE A HINDRANCE ON PRECIP
POTENTIAL. FOR TONIGHT...MODELS INDICATE A STRONG 850MB JET 40-50
KNOTS...WITH WEAK INSTABILITY QUICKLY ADVECTING NORTHWARD ALONG
THE WESTERN EDGE OF THIS FEATURE. COULD BE AN ISOLATED STORM
(ACROSS THE FAR WESTERN FA)...BUT INSTABILITY SEEMS TO BE IN AN
UNFAVORABLE AREA. FOR MONDAY...HIGHER MOISTURE AND LOW LEVEL
CONVERGENCE REMAINS WEST OF THE REGION...WITH AREAS ACROSS
WESTERN AND CENTRAL NORTH DAKOTA (POSSIBLY PORTIONS OF THE DEVILS
LAKE BASIN) MOST LIKELY TO EXPERIENCE SHOWERS.
MAX TEMPS TODAY SHOULD RANGE FROM THE UPPER 60S INTO THE UPPER
70S. THE 06Z RAP IS SHOWING A STRONG WARM FRONT MOVING INTO THE
SW FA...WITH TEMPS INTO THE UPPER 80S. MOST MODELS SHOW THIS
FEATURE...BUT NOT QUITE AS FAR NORTH BY 00Z MONDAY. WILL HAVE TO
MONITOR...FOR NOW STUCK WITH LOW TO MID 80S FOR THIS AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MONDAY NIGHT-TUESDAY NIGHT...THE LOW LEVEL CONVERGENCE SHIFTS
EASTWARD AND THROUGH THE FA. THE LOW LEVEL AIRMASS SHOULD REMAIN
DRY AS THE MAJORITY OF MODELS SHOW THE MAIN UPPER LOW WILL BE WELL
SOUTH OF THE REGION. ANTICIPATE A BAND OF SHOWERS THAT WILL WEAKEN
AS IT MOVES EAST AND FINALLY DIES BY TUESDAY AFTERNOON.
TEMPERATURES WILL DEPEND ON CLOUD COVER...BUT GENERALLY SLIGHTLY
ABOVE NORMAL VALUES.
WEDNESDAY-SATURDAY...500MB SOUTHWEST FLOW ALOFT WILL CONTINUE TO
ALLOW ABOVE NORMAL TEMPERATURES INTO THE NORTHERN PLAINS THRU THE
END OF THE WEEK. TIMING AND PLACEMENT OF SHORT WAVE ENERGY TO
TRACK FROM THE ROCKIES ACROSS THE DAKOTAS STILL UNCERTAIN...
THOUGH BEST CHANCES FOR MEASURABLE RAINFALL WILL BE WITH FROPA ON
FRIDAY. POPS IN THE FORECAST FOR WED AND THURS ARE LESS CERTAIN
ESPECIALLY FROM RED RIVER VALLEY AND EASTWARD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1236 PM CDT SUN SEP 22 2013
TIGHT PRESSURE GRADIENT IN ADIABATIC LAYER NEAR THE SFC WILL RESULT
IN GUSTY SOUTH-SOUTHEAST WINDS TODAY AND TONIGHT. EXPECT SOME LIGHT
TURBULENCE IN THE BOUNDARY LAYER WITH A BIT OF DIRECTIONAL AND SPEED
SHEAR. WINDS WILL WEAKEN A BIT AFTER SUNSET BUT WILL INCREASE AGAIN
WITH INVERSION BREAK NEAR END OF PERIOD. SKIES INITIALLY CLEAR BUT
EXPECT CIRRUS SHIELD TO MOVE INTO THE REGION THIS AFTERNOON AND
OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...GODON
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...HOPKINS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
951 AM CDT SUN SEP 22 2013
.UPDATE...
ISSUED AT 951 AM CDT SUN SEP 22 2013
CURRENTLY HAVE A LITTLE BIT OF THIN CIRRUS OR CONTRAILS ACROSS THE
FAR NORTHERN FA OTHERWISE SKIES ARE STILL CLEAR. MAIN WEATHER
STORY TODAY WILL BE THE GUSTY SOUTHEAST WINDS. CURRENT FORECAST
HAS THINGS WELL IN HAND AND SEE NO REASON FOR ANY UPDATE AT THIS
POINT.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MAIN CHALLENGES WILL BE TEMPERATURES TODAY AND PRECIP CHANCES
TONIGHT INTO MONDAY. 00Z MODELS ARE IN DECENT AGREEMENT THROUGH
THIS PERIOD AND WILL USE A BLEND FOR DETAILS. 500MB LOW WILL
PROPAGATE FROM THE SOUTHWEST CONUS INTO THE CENTRAL PLAINS. THIS
WILL DEVELOP SOUTHWEST FLOW ALOFT BY TONIGHT...CONTINUING INTO
MONDAY. ALTHOUGH LOW LEVEL FLOW WILL SIGNIFICANTLY INCREASE...IT
WILL BE FROM MORE OF A SOUTHEAST DIRECTION...PROMOTING THE VERY
DRY LOW LEVEL AIRMASS. THIS WILL BE A HINDRANCE ON PRECIP
POTENTIAL. FOR TONIGHT...MODELS INDICATE A STRONG 850MB JET 40-50
KNOTS...WITH WEAK INSTABILITY QUICKLY ADVECTING NORTHWARD ALONG
THE WESTERN EDGE OF THIS FEATURE. COULD BE AN ISOLATED STORM
(ACROSS THE FAR WESTERN FA)...BUT INSTABILITY SEEMS TO BE IN AN
UNFAVORABLE AREA. FOR MONDAY...HIGHER MOISTURE AND LOW LEVEL
CONVERGENCE REMAINS WEST OF THE REGION...WITH AREAS ACROSS
WESTERN AND CENTRAL NORTH DAKOTA (POSSIBLY PORTIONS OF THE DEVILS
LAKE BASIN) MOST LIKELY TO EXPERIENCE SHOWERS.
MAX TEMPS TODAY SHOULD RANGE FROM THE UPPER 60S INTO THE UPPER
70S. THE 06Z RAP IS SHOWING A STRONG WARM FRONT MOVING INTO THE
SW FA...WITH TEMPS INTO THE UPPER 80S. MOST MODELS SHOW THIS
FEATURE...BUT NOT QUITE AS FAR NORTH BY 00Z MONDAY. WILL HAVE TO
MONITOR...FOR NOW STUCK WITH LOW TO MID 80S FOR THIS AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MONDAY NIGHT-TUESDAY NIGHT...THE LOW LEVEL CONVERGENCE SHIFTS
EASTWARD AND THROUGH THE FA. THE LOW LEVEL AIRMASS SHOULD REMAIN
DRY AS THE MAJORITY OF MODELS SHOW THE MAIN UPPER LOW WILL BE WELL
SOUTH OF THE REGION. ANTICIPATE A BAND OF SHOWERS THAT WILL WEAKEN
AS IT MOVES EAST AND FINALLY DIES BY TUESDAY AFTERNOON.
TEMPERATURES WILL DEPEND ON CLOUD COVER...BUT GENERALLY SLIGHTLY
ABOVE NORMAL VALUES.
WEDNESDAY-SATURDAY...500MB SOUTHWEST FLOW ALOFT WILL CONTINUE TO
ALLOW ABOVE NORMAL TEMPERATURES INTO THE NORTHERN PLAINS THRU THE
END OF THE WEEK. TIMING AND PLACEMENT OF SHORT WAVE ENERGY TO
TRACK FROM THE ROCKIES ACROSS THE DAKOTAS STILL UNCERTAIN...
THOUGH BEST CHANCES FOR MEASURABLE RAINFALL WILL BE WITH FROPA ON
FRIDAY. POPS IN THE FORECAST FOR WED AND THURS ARE LESS CERTAIN
ESPECIALLY FROM RED RIVER VALLEY AND EASTWARD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 645 AM CDT SUN SEP 22 2013
GUSTY SOUTH-SOUTHEAST WINDS TODAY AND TONIGHT. CLEAR SKY WITH
CIRRUS MOVING INTO THE REGION THIS AFTERNOON AND OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...GODON
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
645 AM CDT SUN SEP 22 2013
.UPDATE...
ISSUED AT 645 AM CDT SUN SEP 22 2013
THE FORECAST IS ON TRACK AND NO UPDATE IS NEEDED. HOWEVER...FORGOT
TO MENTION THE WIND SPEED CHALLENGE IN THE 338 AM SHORT TERM
SECTION. AS OF 645AM...WIND SPEEDS ARE INCREASING AND SHOULD
CONTINUE TO INCREASE THROUGH THE MORNING HOURS. FROM MODEL
SOUNDINGS...EXPECT UNIDIRECTIONAL MIXING LAYER TO AROUND
850MB...WITH ABOUT 30 KNOTS AVAILABLE TO MIX THROUGH THIS LAYER.
THIS SHOULD LEAD TO SPEEDS AOA 20 MPH MOST AREAS...WITH GUSTS TO
30 MPH ALONG AND WEST OF THE VALLEY. DO NOT ANTICIPATE ADVISORY
CONDITIONS...BUT WILL MONITOR.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MAIN CHALLENGES WILL BE TEMPERATURES TODAY AND PRECIP CHANCES
TONIGHT INTO MONDAY. 00Z MODELS ARE IN DECENT AGREEMENT THROUGH
THIS PERIOD AND WILL USE A BLEND FOR DETAILS. 500MB LOW WILL
PROPAGATE FROM THE SOUTHWEST CONUS INTO THE CENTRAL PLAINS. THIS
WILL DEVELOP SOUTHWEST FLOW ALOFT BY TONIGHT...CONTINUING INTO
MONDAY. ALTHOUGH LOW LEVEL FLOW WILL SIGNIFICANTLY INCREASE...IT
WILL BE FROM MORE OF A SOUTHEAST DIRECTION...PROMOTING THE VERY
DRY LOW LEVEL AIRMASS. THIS WILL BE A HINDRANCE ON PRECIP
POTENTIAL. FOR TONIGHT...MODELS INDICATE A STRONG 850MB JET 40-50
KNOTS...WITH WEAK INSTABILITY QUICKLY ADVECTING NORTHWARD ALONG
THE WESTERN EDGE OF THIS FEATURE. COULD BE AN ISOLATED STORM
(ACROSS THE FAR WESTERN FA)...BUT INSTABILITY SEEMS TO BE IN AN
UNFAVORABLE AREA. FOR MONDAY...HIGHER MOISTURE AND LOW LEVEL
CONVERGENCE REMAINS WEST OF THE REGION...WITH AREAS ACROSS
WESTERN AND CENTRAL NORTH DAKOTA (POSSIBLY PORTIONS OF THE DEVILS
LAKE BASIN) MOST LIKELY TO EXPERIENCE SHOWERS.
MAX TEMPS TODAY SHOULD RANGE FROM THE UPPER 60S INTO THE UPPER
70S. THE 06Z RAP IS SHOWING A STRONG WARM FRONT MOVING INTO THE
SW FA...WITH TEMPS INTO THE UPPER 80S. MOST MODELS SHOW THIS
FEATURE...BUT NOT QUITE AS FAR NORTH BY 00Z MONDAY. WILL HAVE TO
MONITOR...FOR NOW STUCK WITH LOW TO MID 80S FOR THIS AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MONDAY NIGHT-TUESDAY NIGHT...THE LOW LEVEL CONVERGENCE SHIFTS
EASTWARD AND THROUGH THE FA. THE LOW LEVEL AIRMASS SHOULD REMAIN
DRY AS THE MAJORITY OF MODELS SHOW THE MAIN UPPER LOW WILL BE WELL
SOUTH OF THE REGION. ANTICIPATE A BAND OF SHOWERS THAT WILL WEAKEN
AS IT MOVES EAST AND FINALLY DIES BY TUESDAY AFTERNOON.
TEMPERATURES WILL DEPEND ON CLOUD COVER...BUT GENERALLY SLIGHTLY
ABOVE NORMAL VALUES.
WEDNESDAY-SATURDAY...500MB SOUTHWEST FLOW ALOFT WILL CONTINUE TO
ALLOW ABOVE NORMAL TEMPERATURES INTO THE NORTHERN PLAINS THRU THE
END OF THE WEEK. TIMING AND PLACEMENT OF SHORT WAVE ENERGY TO
TRACK FROM THE ROCKIES ACROSS THE DAKOTAS STILL UNCERTAIN...
THOUGH BEST CHANCES FOR MEASURABLE RAINFALL WILL BE WITH FROPA ON
FRIDAY. POPS IN THE FORECAST FOR WED AND THURS ARE LESS CERTAIN
ESPECIALLY FROM RED RIVER VALLEY AND EASTWARD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 645 AM CDT SUN SEP 22 2013
GUSTY SOUTH-SOUTHEAST WINDS TODAY AND TONIGHT. CLEAR SKY WITH
CIRRUS MOVING INTO THE REGION THIS AFTERNOON AND OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
338 AM CDT SUN SEP 22 2013
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MAIN CHALLENGES WILL BE TEMPERATURES TODAY AND PRECIP CHANCES
TONIGHT INTO MONDAY. 00Z MODELS ARE IN DECENT AGREEMENT THROUGH
THIS PERIOD AND WILL USE A BLEND FOR DETAILS. 500MB LOW WILL
PROPAGATE FROM THE SOUTHWEST CONUS INTO THE CENTRAL PLAINS. THIS
WILL DEVELOP SOUTHWEST FLOW ALOFT BY TONIGHT...CONTINUING INTO
MONDAY. ALTHOUGH LOW LEVEL FLOW WILL SIGNIFICANTLY INCREASE...IT
WILL BE FROM MORE OF A SOUTHEAST DIRECTION...PROMOTING THE VERY
DRY LOW LEVEL AIRMASS. THIS WILL BE A HINDRANCE ON PRECIP
POTENTIAL. FOR TONIGHT...MODELS INDICATE A STRONG 850MB JET 40-50
KNOTS...WITH WEAK INSTABILITY QUICKLY ADVECTING NORTHWARD ALONG
THE WESTERN EDGE OF THIS FEATURE. COULD BE AN ISOLATED STORM
(ACROSS THE FAR WESTERN FA)...BUT INSTABILITY SEEMS TO BE IN AN
UNFAVORABLE AREA. FOR MONDAY...HIGHER MOISTURE AND LOW LEVEL
CONVERGENCE REMAINS WEST OF THE REGION...WITH AREAS ACROSS
WESTERN AND CENTRAL NORTH DAKOTA (POSSIBLY PORTIONS OF THE DEVILS
LAKE BASIN) MOST LIKELY TO EXPERIENCE SHOWERS.
MAX TEMPS TODAY SHOULD RANGE FROM THE UPPER 60S INTO THE UPPER
70S. THE 06Z RAP IS SHOWING A STRONG WARM FRONT MOVING INTO THE
SW FA...WITH TEMPS INTO THE UPPER 80S. MOST MODELS SHOW THIS
FEATURE...BUT NOT QUITE AS FAR NORTH BY 00Z MONDAY. WILL HAVE TO
MONITOR...FOR NOW STUCK WITH LOW TO MID 80S FOR THIS AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MONDAY NIGHT-TUESDAY NIGHT...THE LOW LEVEL CONVERGENCE SHIFTS
EASTWARD AND THROUGH THE FA. THE LOW LEVEL AIRMASS SHOULD REMAIN
DRY AS THE MAJORITY OF MODELS SHOW THE MAIN UPPER LOW WILL BE WELL
SOUTH OF THE REGION. ANTICIPATE A BAND OF SHOWERS THAT WILL WEAKEN
AS IT MOVES EAST AND FINALLY DIES BY TUESDAY AFTERNOON.
TEMPERATURES WILL DEPEND ON CLOUD COVER...BUT GENERALLY SLIGHTLY
ABOVE NORMAL VALUES.
WEDNESDAY-SATURDAY...500MB SOUTHWEST FLOW ALOFT WILL CONTINUE TO
ALLOW ABOVE NORMAL TEMPERATURES INTO THE NORTHERN PLAINS THRU THE
END OF THE WEEK. TIMING AND PLACEMENT OF SHORT WAVE ENERGY TO
TRACK FROM THE ROCKIES ACROSS THE DAKOTAS STILL UNCERTAIN...
THOUGH BEST CHANCES FOR MEASURABLE RAINFALL WILL BE WITH FROPA ON
FRIDAY. POPS IN THE FORECAST FOR WED AND THURS ARE LESS CERTAIN
ESPECIALLY FROM RED RIVER VALLEY AND EASTWARD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1152 PM CDT SAT SEP 21 2013
EXPECT GUSTY SOUTH-SOUTHEAST WIND TO DEVELOP MID MORNING
SUNDAY...WITH SUSTAINED IN THE RED RIVER VALLEY AND ERN ND IN THE
15 TO 25 KT RANGE WITH GUSTS 25-30 KTS PSBL. LIGHTER WINDS IN
BEMIDJI. CLEAR SKY WITH SOME CIRRUS MOVING IN THE AFTN AND AT
NIGHT. SOUTHEAST WINDS TO STAY UP PAST SUNSET SUNDAY EVENING DUE
TO TIGHT PRESSURE GRADIENT AHD OF NEXT LOW MOVING NORTH.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
725 PM EDT MON SEP 23 2013
.SYNOPSIS...
LARGE AREA OF CANADIAN HIGH PRESSURE CENTERED OVER THE GREAT LAKES
WILL REMAIN NEARLY STATIONARY THROUGH LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A SURFACE RIDGE CONTINUES TO BUILD IN. THE BIG QUESTION IS HOW
COLD WILL IT GET AND HOW MUCH FROST WILL FORM. AT THIS TIME THE
CLOUDS ARE DEFINITELY ON THE DECREASE. THE HRRR AND MOST OF THE
MODELS INDICATE THAT MOST AREAS WILL BECOME MOSTLY
CLEAR...HOWEVER...SOME CLOUDS WILL LINGER OR REDEVELOP OVER THE
EXTREME NORTHWEST. THE MAIN AREA OF CONCERN FOR FROST IS IN THE
EAST. HAVE MADE NO CHANGES TO THE FROST ADVISORY OVER INLAND
AREAS OF NW PA AND EXTREME NE OH. OVER THE CENTRAL HIGHLANDS WILL
CONTINUE WITH PATCHY FROST. USED A BLEND OF GUIDANCE FOR THE
LOWS. WILL WATCH TO SEE WHETHER FROST NEEDS TO BE ADDED TO MORE
AREAS AND WHETHER THE ADVISORY NEEDS TO BE EXPANDED.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
THE RIDGE WILL BE NORTH TO SOUTH ACROSS THE AREA THROUGH THURSDAY
AND THEN IT WILL SLOWLY SHIFT TO THE EAST. ON TUESDAY MOSTLY SUNNY
SKIES EXCEPT NEAR TOLEDO. AN UPPER LOW WILL MOVE ACROSS THE OHIO
VALLEY TUESDAY NIGHT INTO WEDNESDAY EVENING. THE MAIN AFFECT FROM
THIS SYSTEM WILL BE SOME CIRRUS. WILL GO FOR PARTLY CLOUDY.
OTHERWISE MOSTLY CLEAR OR MOSTLY SUNNY. USED A BLEND OF GUIDANCE
FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH AMPLITUDE RIDGE ALOFT BUILDS OVER THE GREAT LAKES ON FRIDAY.
SURFACE HIGH PRESSURE WILL BE OVER THE EASTERN GREAT LAKES WITH AN
EASTERLY LOW LEVEL FLOW. EXPECTING TEMPERATURES TO CLIMB ABOVE
NORMAL INTO THE MID 70S MOST AREAS WITH FULL SUN. THE FLOW BACKS
AROUND TO MORE SOUTHERLY ON SATURDAY AS THE SURFACE HIGH SHIFTS
TOWARDS THE EAST COAST WITH ABOVE NORMAL TEMPERATURES MAKING A RUN
AT 80 DEGREES IN THE WEST.
THE NEXT TROUGH WILL LIFT OUT OF THE PLAINS TOWARDS THE AREA ON
SUNDAY. THE GFS WHICH HAS OFFERED A FASTER AND MORE PROGRESSIVE
SOLUTION IS SHOWING SIGNS OF SLOWING DOWN WITH A DEEPER
TROUGH...MORE IN LINE WITH THE ECMWF AND GEM. REMOVED THE LOW POP
FROM SATURDAY NIGHT IN THE EASTERN COUNTIES WITH A CHANCE OF SHOWERS
STILL IN THE FORECAST FOR SUNDAY AND SUNDAY NIGHT. POPS MAY NEED TO
BE SLOWED DOWN FURTHER GIVEN THE DEPTH OF THE WESTERN TROUGH WITH
SOME POTENTIAL FOR THE UPPER LOW TO CLOSE OFF OVER THE FOUR CORNERS
REGION.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
THE STRATO CU FIELD CONTINUES TO QUICKLY DISSIPATE AND SHOULD BE
GONE IN A COUPLE OF HOURS. AT THE SAME TIME...WINDS WILL BECOME
LIGHT AND VARIABLE WHICH WILL ALLOW SOME PATCHY MVFR FOG DEVELOP
OVERNIGHT AWAY FROM LAKE ERIE. PLACES LIKE KYNG EVEN HAVE A SHOT
OF A BRIEF PERIOD OF IFR TOWARD MORNING. A FEW CLOUDS COULD MOVE
OFF OF LAKE ERIE LATER TONIGHT AND AFFECT NW OHIO. JUST A FEW CU
ON TUESDAY WITH MAINLY LIGHT EASTERLY FLOW.
OUTLOOK...VFR.
&&
.MARINE...
GOOD MARINE CONDITIONS EXPECTED THIS WEEK WITH HIGH PRESSURE
REMAINING NEARLY STATIONARY OVER THE EASTERN GREAT LAKES. A LIGHT
NORTHEASTERLY FLOW WILL INCREASE SLIGHTLY ON WEDNESDAY AS A WEAK
SYSTEM MOVES THROUGH THE LOWER OHIO VALLEY. THE HIGH WILL STRENGTHEN
AGAIN FOR THE END OF THE WEEK BEFORE SHIFTING TOWARDS THE EAST
COAST. WINDS WILL GENERALLY BE 10 KNOTS OR LESS WITH WAVES OF 2 FEET
OR LESS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FROST ADVISORY FROM 3 AM TO 9 AM EDT TUESDAY FOR OHZ013-014-
022-023-033.
PA...FROST ADVISORY FROM 3 AM TO 9 AM EDT TUESDAY FOR PAZ002-003.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA/OUDEMAN
SHORT TERM...KIELTYKA
LONG TERM...KEC
AVIATION...KUBINA
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
617 PM EDT SUN SEP 22 2013
.SYNOPSIS...
COOL CANADIAN HIGH PRESSURE WILL BUILD EAST ACROSS THE GREAT LAKES
THROUGH MONDAY. THIS HIGH WILL REMAIN IN THE GREAT LAKES VICINITY
THROUGH MOST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE GREAT LAKES REGION REMAINS BETWEEN AN UPPER LEVEL TROUGH OVER
QUEBEC AND A RIDGE BUILDING OVER THE UPPER MIDWEST. ENOUGH
TROUGHINESS REMAINS ALONG WITH THE 850MB COLD POOL(TEMPS DOWN TO -2C
OVER ONTARIO) TO MAINTAIN CONSIDERABLE CLOUD COVER ACROSS THE
SOUTHERN ONTARIO AND QUEBEC THIS AFTERNOON. CLOUDS ALSO EXTEND
DOWNWIND OFF ALL OF THE GREAT LAKES...EVEN NEARLY OVERCAST SKIES
OVER LAKE MICHIGAN DIRECTLY BENEATH THE SURFACE HIGH. AS NOTED
EARLY...NAM SOUNDINGS ARE ALREADY RUNNING A LITTLE TOO OPTIMISTIC
WITH CLEARING WHILE RUC SOUNDINGS KEEP EASTERN AREAS CLOUDY ALL
NIGHT BENEATH THE LOWERING INVERSION. HRRR IS SIMILAR. WILL CARRY
A MOSTLY CLEAR FORECAST TOWARDS FINDLAY WITH MOSTLY CLOUDY SKIES
FOR MOST OF THE NIGHT ACROSS THE EASTERN HALF OF THE AREA. CAN
ALREADY SEE CLOUDS RETURNING WEST OF CLEVELAND WITH LITTLE MESO
LOW COMING ASHORE NEAR LAKE COUNTY. MOS GUIDANCE ALSO TOO QUICK
WITH THE CLEARING TREND SO WILL GO 2-5 DEGREES WARMER TONIGHT FOR
AREAS EAST OF A CLE-CAK LINE. TEMPERATURES WILL FALL QUICKLY WITH
ANY SIZABLE BREAKS IN THE CLOUDS. HAVE ADDED A FEW SHOWERS TO
LAKE/ASHTABULA/GEAUGA COUNTIES WITH THE MESO LOW. A FEW RADAR
RETURNS MIGHT ACTUALLY ACCUMULATE 0.01 INCHES EARLY THIS EVENING.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
A DRY STRETCH OF WEATHER WITH COOL NIGHTS TO FOLLOW DURING THE SHORT
TERM. HIGH PRESSURE WILL REMAIN OVER THE EASTERN GREAT LAKES THROUGH
TUESDAY...SHIFTING SLIGHTLY TO THE NORTH ON WEDNESDAY. DIURNAL CU
EXPECTED ONCE AGAIN ON MONDAY BEFORE WE FINALLY MIX OUT OUR MOISTURE
AND CLEAR FOR MONDAY NIGHT. THIS WILL SET UP FOR A CHILLY NIGHT ON
MONDAY WITH MOST INLAND AREAS DIPPING TO NEAR 40 DEGREES. SOME OF
THE COOLER SPOTS IN NE OHIO WILL DIP INTO THE UPPER 30S WITH MID 30S
FOR INTERIOR NW PA. HAVE INCLUDED AREAS OF FROST FOR THOSE COOLEST
SPOTS AND THERE IS POTENTIAL THAT WE MAY NEED A FROST ADVISORY FOR
ERIE AND CRAWFORD PA. A HEALTHY DIURNAL SPREAD WILL ALLOW HIGHS TO
RECOVER INTO THE LOW AND MID 60S FOR TUESDAY...THEN COOL BACK INTO
THE 40S FOR TUESDAY NIGHT. LEANED THE FORECAST TOWARDS THE RAW MODEL
TEMPERATURES WHICH ARE SLIGHTLY COOLER THAN MOS GUIDANCE THROUGH THE
SHORT TERM.
UPPER LEVEL LOW OVER THE GREAT BASIN WILL MOVE NORTHEAST ACROSS THE
PLAINS ON MONDAY AND ENCOUNTER SOME RESISTANCE BY THE HIGH AMPLITUDE
UPPER LEVEL RIDGE OVER THE GREAT LAKES REGION. THE UPPER LOW WILL
WEAKEN AS IT SLIDES EAST ACROSS THE OHIO VALLEY ON TUESDAY NIGHT AND
WEDNESDAY. MODELS KEEP THE QPF SOUTH OF THE FORECAST AREA AND GIVEN
THE RESIDENT DRY AIRMASS IN PLACE...WILL KEEP THE FORECAST DRY WITH
JUST SOME INCREASE IN CLOUDS ON WEDNESDAY. TEMPS WILL RETURN TO NEAR
70 MOST AREAS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A RIDGE OF HIGH PRESSURE WILL BE OVER THE AREA TO START THE FORECAST
PERIOD AND THEN IT WILL SHIFT SLOWLY EAST AS A WEAKENING COLD FRONT
ADVANCES TOWARDS THE REGION. SOME QUESTION AS TO THE TIMING OF THE
FRONT FOR LATE IN THE WEEKEND. THE 12Z GFS IS MUCH QUICKER THAN THE
ECMWF AND THE CANADIAN MODEL. AT THIS TIME LEANING MORE TOWARD THE
SLOWER MODELS. SO THE MAIN CHANCE OF PRECIPITATION WILL BE ON SUNDAY
INTO SUNDAY NIGHT. IT SEEMS STABLE SO ONLY FORECASTING SHOWERS. USED
A BLEND OF GUIDANCE FOR THE NEAR NORMAL TEMPERATURES.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE IS BUILDING IN AT THE SURFACE. THE LAKE AND 850 MB
TEMPERATURE DIFFERENCE IS NEAR 19C AND WILL SLOWLY WARM OVERNIGHT.
THE CLOUDS ARE THICKENING WITH SOME AFTERNOON SUN. THE BIG DILEMMA
IS HOW MUCH WILL THE CLOUDS DECREASE OVERNIGHT. WILL DECREASE THE
CLOUDS TO SCATTERED OVER NW OH AND AT INLAND LOCATIONS. TOO DRY
FOR FOG AT THE TAF SITES. ANY CLOUDS AT SUNRISE MONDAY WILL SLOWLY
DECREASE AS THE SUBSIDENCE AND DRIER AIR CONTINUE TO WORK IN.
OUTLOOK...MAINLY VFR.
&&
.MARINE...
A RIDGE OF HIGH PRESSURE WILL BE BUILDING IN TONIGHT. WILL LET THE
SMALL CRAFT ADVISORY AND RIP CURRENT RISK EXPIRE/CANCEL AS THE WINDS
AND WAVES ARE DECREASING. HOWEVER AS THE RIDGE IS BUILDING IN
TONIGHT THE NORTHEAST FLOW GRADIENT WILL INCREASE AND THAT COULD
CAUSE THE WAVES TO GET CLOSE TO SMALL CRAFT ADVISORY CRITERIA AND
AGAIN ON MONDAY. HOWEVER...AT THIS TIME IT SEEMS THAT 2 TO 4 FOOT
WAVES SHOULD HANDLE IT. AS THE RIDGE BECOMES STRONGER MONDAY NIGHT
AND TUESDAY THE WINDS WILL BE LIGHTER...THUS DECREASING THE WAVES.
THE RIDGE WILL BE AROUND THE LAKE THROUGH FRIDAY AND THAT WILL MEAN
AN EAST OR NORTHEAST FLOW. AT THIS TIME A SMALL CRAFT ADVISORY IS
NOT EXPECTED AS THE NORTHEAST FLOW SHOULD NOT BE STRONG ENOUGH TO
CAUSE 3 TO 5 FOOT WAVES BUT THIS WILL HAVE TO BE WATCHED AS
NORTHEAST FLOWS ARE NOTORIOUS FOR CAUSING HIGH WAVES ESPECIALLY ON
THE WEST END OF THE LAKE BECAUSE OF THE LONG FETCH.
A COLD FRONT WILL BE APPROACHING THE LAKE FOR LATE IN THE UPCOMING
WEEKEND SHIFTING THE WINDS TO SOUTHERLY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC/OUDEMAN
SHORT TERM...KEC
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
404 PM EDT SUN SEP 22 2013
.SYNOPSIS...
COOL CANADIAN HIGH PRESSURE WILL BUILD EAST ACROSS THE GREAT LAKES
THROUGH MONDAY. THIS HIGH WILL REMAIN IN THE GREAT LAKES VICINITY
THROUGH MOST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE GREAT LAKES REGION REMAINS BETWEEN AN UPPER LEVEL TROUGH OVER
QUEBEC AND A RIDGE BUILDING OVER THE UPPER MIDWEST. ENOUGH
TROUGHINESS REMAINS ALONG WITH THE 850MB COLD POOL(TEMPS DOWN TO -2C
OVER ONTARIO) TO MAINTAIN CONSIDERABLE CLOUD COVER ACROSS THE
SOUTHERN ONTARIO AND QUEBEC THIS AFTERNOON. CLOUDS ALSO EXTEND
DOWNWIND OFF ALL OF THE GREAT LAKES...EVEN NEARLY OVERCAST SKIES
OVER LAKE MICHIGAN DIRECTLY BENEATH THE SURFACE HIGH. AS NOTED
EARLY...NAM SOUNDINGS ARE ALREADY RUNNING A LITTLE TOO OPTIMISTIC
WITH CLEARING WHILE RUC SOUNDINGS KEEP EASTERN AREAS CLOUDY ALL
NIGHT BENEATH THE LOWERING INVERSION. WILL CARRY A MOSTLY CLEAR
FORECAST TOWARDS FINDLAY WITH MOSTLY CLOUDY SKIES FOR MOST OF THE
NIGHT ACROSS THE EASTERN HALF OF THE AREA. MOS GUIDANCE ALSO TOO
QUICK WITH THE CLEARING TREND SO WILL GO 2-5 DEGREES WARMER TONIGHT
FOR AREAS EAST OF A CLE-CAK LINE. TEMPERATURES WILL FALL QUICKLY
WITH ANY SIZABLE BREAKS IN THE CLOUDS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
A DRY STRETCH OF WEATHER WITH COOL NIGHTS TO FOLLOW DURING THE SHORT
TERM. HIGH PRESSURE WILL REMAIN OVER THE EASTERN GREAT LAKES THROUGH
TUESDAY...SHIFTING SLIGHTLY TO THE NORTH ON WEDNESDAY. DIURNAL CU
EXPECTED ONCE AGAIN ON MONDAY BEFORE WE FINALLY MIX OUT OUR MOISTURE
AND CLEAR FOR MONDAY NIGHT. THIS WILL SET UP FOR A CHILLY NIGHT ON
MONDAY WITH MOST INLAND AREAS DIPPING TO NEAR 40 DEGREES. SOME OF
THE COOLER SPOTS IN NE OHIO WILL DIP INTO THE UPPER 30S WITH MID 30S
FOR INTERIOR NW PA. HAVE INCLUDED AREAS OF FROST FOR THOSE COOLEST
SPOTS AND THERE IS POTENTIAL THAT WE MAY NEED A FROST ADVISORY FOR
ERIE AND CRAWFORD PA. A HEALTHY DIURNAL SPREAD WILL ALLOW HIGHS TO
RECOVER INTO THE LOW AND MID 60S FOR TUESDAY...THEN COOL BACK INTO
THE 40S FOR TUESDAY NIGHT. LEANED THE FORECAST TOWARDS THE RAW MODEL
TEMPERATURES WHICH ARE SLIGHTLY COOLER THAN MOS GUIDANCE THROUGH THE
SHORT TERM.
UPPER LEVEL LOW OVER THE GREAT BASIN WILL MOVE NORTHEAST ACROSS THE
PLAINS ON MONDAY AND ENCOUNTER SOME RESISTANCE BY THE HIGH AMPLITUDE
UPPER LEVEL RIDGE OVER THE GREAT LAKES REGION. THE UPPER LOW WILL
WEAKEN AS IT SLIDES EAST ACROSS THE OHIO VALLEY ON TUESDAY NIGHT AND
WEDNESDAY. MODELS KEEP THE QPF SOUTH OF THE FORECAST AREA AND GIVEN
THE RESIDENT DRY AIRMASS IN PLACE...WILL KEEP THE FORECAST DRY WITH
JUST SOME INCREASE IN CLOUDS ON WEDNESDAY. TEMPS WILL RETURN TO NEAR
70 MOST AREAS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A RIDGE OF HIGH PRESSURE WILL BE OVER THE AREA TO START THE FORECAST
PERIOD AND THEN IT WILL SHIFT SLOWLY EAST AS A WEAKENING COLD FRONT
ADVANCES TOWARDS THE REGION. SOME QUESTION AS TO THE TIMING OF THE
FRONT FOR LATE IN THE WEEKEND. THE 12Z GFS IS MUCH QUICKER THAN THE
ECMWF AND THE CANADIAN MODEL. AT THIS TIME LEANING MORE TOWARD THE
SLOWER MODELS. SO THE MAIN CHANCE OF PRECIPITATION WILL BE ON SUNDAY
INTO SUNDAY NIGHT. IT SEEMS STABLE SO ONLY FORECASTING SHOWERS. USED
A BLEND OF GUIDANCE FOR THE NEAR NORMAL TEMPERATURES.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE IS BUILDING IN AT THE SURFACE. THE LAKE AND 850 MB
TEMPERATURE DIFFERENCE IS NEAR 19C AND WILL SLOWLY WARM OVERNIGHT.
THE CLOUDS ARE THICKENING WITH SOME AFTERNOON SUN. THE BIG DILEMMA
IS HOW MUCH WILL THE CLOUDS DECREASE OVERNIGHT. WILL DECREASE THE
CLOUDS TO SCATTERED OVER NW OH AND AT INLAND LOCATIONS. TOO DRY
FOR FOG AT THE TAF SITES. ANY CLOUDS AT SUNRISE MONDAY WILL SLOWLY
DECREASE AS THE SUBSIDENCE AND DRIER AIR CONTINUE TO WORK IN.
OUTLOOK...MAINLY VFR.
&&
.MARINE...
A RIDGE OF HIGH PRESSURE WILL BE BUILDING IN TONIGHT. WILL LET THE
SMALL CRAFT ADVISORY AND RIP CURRENT RISK EXPIRE/CANCEL AS THE WINDS
AND WAVES ARE DECREASING. HOWEVER AS THE RIDGE IS BUILDING IN
TONIGHT THE NORTHEAST FLOW GRADIENT WILL INCREASE AND THAT COULD
CAUSE THE WAVES TO GET CLOSE TO SMALL CRAFT ADVISORY CRITERIA AND
AGAIN ON MONDAY. HOWEVER...AT THIS TIME IT SEEMS THAT 2 TO 4 FOOT
WAVES SHOULD HANDLE IT. AS THE RIDGE BECOMES STRONGER MONDAY NIGHT
AND TUESDAY THE WINDS WILL BE LIGHTER...THUS DECREASING THE WAVES.
THE RIDGE WILL BE AROUND THE LAKE THROUGH FRIDAY AND THAT WILL MEAN
AN EAST OR NORTHEAST FLOW. AT THIS TIME A SMALL CRAFT ADVISORY IS
NOT EXPECTED AS THE NORTHEAST FLOW SHOULD NOT BE STRONG ENOUGH TO
CAUSE 3 TO 5 FOOT WAVES BUT THIS WILL HAVE TO BE WATCHED AS
NORTHEAST FLOWS ARE NOTORIOUS FOR CAUSING HIGH WAVES ESPECIALLY ON
THE WEST END OF THE LAKE BECAUSE OF THE LONG FETCH.
A COLD FRONT WILL BE APPROACHING THE LAKE FOR LATE IN THE UPCOMING
WEEKEND SHIFTING THE WINDS TO SOUTHERLY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
936 PM CDT MON SEP 23 2013
.UPDATE...
SEE DISCUSSION FOR EVENING UPDATE.
&&
.DISCUSSION...
PARTLY CLOUDY SKIES ACROSS SOUTHEAST TEXAS THIS EVENING. CLOUDS
HAVE STARTED TO BREAK BUT COOLING WILL BE LIMITED TONIGHT AS
MOISTURE HAS STARTED TO WORK ITS WAY BACK INTO SOUTHEAST TEXAS.
DEEP MOISTURE HAS REMAINED OFF THE COAST THOUGH WHICH THE GFS HAS
DONE A PRETTY GOOD JOB FORECASTING. CURRENT PWATS ARE AROUND 2"
AT KGLS WHILE AROUND 1.7" IN THE CITY OF HOUSTON. ANOTHER FRONT
WILL WORK ITS WAY INTO THE AREA TUESDAY WHICH WILL MOST LIKELY BE
A DRY FRONTAL PASSAGE. BETTER MOISTURE LAYS OFF TO THE NORTHEAST
SO OUR FAR NORTHEASTERN COUNTIES MIGHT SEE SOME PRECIPITATION.
BEHIND THE FRONT MUCH DRIER AIR WILL BE USHERED IN. PWAT VALUES
FALL BELOW AN INCH AT KCLL BY 0Z WEDNESDAY IN BOTH GFS AND NAM
SOUNDINGS. DUE TO THIS DRIER AIR AND A RELATIVELY WARM START TO
THE DAY TOMORROW HIGH TEMPERATURES WILL LIKELY CLIMB INTO THE
LOWER TO MID 90S. CURRENT FORECAST HAS THIS COVERED ONLY MADE
MINOR TWEAKS TO GRIDS. 23
&&
.PREV DISCUSSION... /ISSUED 614 PM CDT MON SEP 23 2013/
DISCUSSION...
SEE 00Z AVIATION DISCUSSION.
AVIATION...
BOTH THE NAM AND GFS SHOW CONSIDERABLY LESS POTENTIAL FOR BKN CIGS
OVERNIGHT WITH PW VALUES LOWER THAN THIS TIME YESTERDAY. LIGHT
EAST WINDS WILL PREVAIL DURING THE OVERNIGHT PERIOD. BOTH THE HRRR
AND RAP SHOW SHRA DEVELOPING BETWEEN 09-11Z OVER THE EASTERN TAF
SITES. NOT SURE MOISTURE LEVELS WILL BE DEEP ENOUGH FOR THIS TO
OCCUR. WILL WATCH TREND AND ADD SHRA AT 06Z IF OTHER MODELS BEGIN
TO CATCH ON TO THIS. LAST NIGHT THE TEXAS TECH 3 KM WRF WAS THE
MODEL OF CHOICE AND TONIGHT THIS MODEL SHOWS THE PRECIP STAYING
OVER LOUISIANA. ON TUESDAY...DRIER AIR WILL FILTER INTO SE TX AND
AM EXPECTING CLEAR SKIES AREAWIDE BY 00Z WED. 43
PREV DISCUSSION... /ISSUED 319 PM CDT MON SEP 23 2013/
DISCUSSION...
SFC ANALYSIS HAS LOW PRESSURE A COUPLE HUNDRED MILES OFF THE
COAST SOUTH OF GALVESTON IN THE NW GULF. CONVECTION HAS BEEN A BIT
MORE ORGANIZED AROUND AN ELONGATED CIRCULATION SEEN ON VIS
SATELLITE IMAGERY. WATER VAPOR IMAGERY CONTINUES TO SHOW QUITE A
BIT OF DRY AIR AROUND THE SYSTEM SO DO NOT SEE THERE BEING ANY
TROPICAL DEVELOPMENT AT ALL WITH THIS SYSTEM. UPPER AIR ANALYSIS
HAS UPPER LOW OVER THE ROCKIES WHICH HAS NOW PULLED INTO THE
PLAINS PER WATER VAPOR IMAGERY. SUSPECT THIS ALONG WITH
CYCLOGENESIS IN THE PLAINS WILL HELP TO TRY AND DRAW THE GULF
CIRCULATION TOWARDS THE COAST TONIGHT INTO TOMORROW. FORECAST WILL
KEEP SOME SMALL RAIN CHANCES ALONG THE COAST OVERNIGHT INTO TUE
BUT REALLY NOT EXPECTED MUCH PRECIP FOR INLAND AREAS.
UPPER LOW IN PLAINS SHOULD SHEAR OUT AND WEAKEN WITH THE NEGATIVE
TILT TOMORROW INTO WED. THIS DOES ALLOW FOR A PACIFIC FRONT TO
PUSH INTO THE AREA TOMORROW AND TUE NIGHT. THE MAIN EFFECT WILL BE
TO PROVIDE SOME DRIER AIR FOR THE AREA SO LOOKS LIKE MAYBE A
COUPLE MORE COOL MORNINGS BEFORE MOISTURE RETURN FLOW OFF THE GULF
STARTS IN EARNEST BY THE END OF THE WEEK.
UPPER LEVEL RIDGE SHOULD DEVELOP OVER THE AREA MID WEEK WITH A
BROAD TROUGH DEVELOPING OVER THE GREAT BASIN AND ROCKIES. THE
ECMWF/GFS/CANADIAN ARE IN A LITTLE MORE AGREEMENT WITH THIS
TROUGHS EVOLUTION AND THIS WILL BE KEY WITH REGARDS TO THIS
WEEKEND`S POTENTIAL COLD FRONT. UPPER TROUGH HAS ONE PIECE OF
VORTICITY THAT MOVES INTO THE N PLAINS ON THUR WITH THE MAIN
TROUGH LAGGING BACK OVER THE SIERRA NEVADAS ON THUR. THE MAIN
UPPER LOW LAGS BACK OVER THE 4 CORNERS REGION INTO SAT BEFORE
MOVING INTO THE PLAINS SAT NIGHT. THIS IS ABOUT 12-24 HRS SLOWER
THAN THE PREVIOUS MODEL RUNS AND SEEMS LIKE ALL MODELS ARE
TRENDING SLOWER WITH THE UPPER LOW. SO WITH THAT LOOKS LIKE THE
COLD FRONT WILL BE SLOWER TO MOVE INTO THE AREA. WILL STILL KEEP
30 POPS AS THERE WILL BE GOOD MOISTURE AND THINK CONVECTION SHOULD
DEVELOP FRI/SAT BUT BEST CHANCES STILL LOOK TO BE MORE ON SUNDAY.
COLD FRONT IS SET TO PUSH THROUGH DURING THE DAY SUN PER
GFS/ECMWF. MAIN PROBLEM WILL BE TO WATCH AND SEE IF THE FRONT
STALLS BEFORE REACHING THE COAST. THIS MAY BE A POSSIBILITY SINCE
THERE WILL BE SOME UPPER LEVEL RIDGING AND THE FRONT COULD BECOME
MORE ORIENTED PARALLEL TO MEAN UPPER FLOW. THINK THIS MAY BE MORE
THE CASE AND EXPECT TO SEE MODELS TREND IN THIS DIRECTION.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 69 94 67 93 67 / 10 10 10 10 10
HOUSTON (IAH) 72 94 68 94 68 / 10 10 10 10 10
GALVESTON (GLS) 78 90 76 90 78 / 20 20 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 1 AM CDT TUESDAY FOR
THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA
SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 1 AM CDT TUESDAY 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.
&&
$$
DISCUSSION...23
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
614 PM CDT MON SEP 23 2013
.DISCUSSION...
SEE 00Z AVIATION DISCUSSION.
&&
.AVIATION...
BOTH THE NAM AND GFS SHOW CONSIDERABLY LESS POTENTIAL FOR BKN CIGS
OVERNIGHT WITH PW VALUES LOWER THAN THIS TIME YESTERDAY. LIGHT
EAST WINDS WILL PREVAIL DURING THE OVERNIGHT PERIOD. BOTH THE HRRR
AND RAP SHOW SHRA DEVELOPING BETWEEN 09-11Z OVER THE EASTERN TAF
SITES. NOT SURE MOISTURE LEVELS WILL BE DEEP ENOUGH FOR THIS TO
OCCUR. WILL WATCH TREND AND ADD SHRA AT 06Z IF OTHER MODELS BEGIN
TO CATCH ON TO THIS. LAST NIGHT THE TEXAS TECH 3 KM WRF WAS THE
MODEL OF CHOICE AND TONIGHT THIS MODEL SHOWS THE PRECIP STAYING
OVER LOUISIANA. ON TUESDAY...DRIER AIR WILL FILTER INTO SE TX AND
AM EXPECTING CLEAR SKIES AREAWIDE BY 00Z WED. 43
&&
.PREV DISCUSSION... /ISSUED 319 PM CDT MON SEP 23 2013/
DISCUSSION...
SFC ANALYSIS HAS LOW PRESSURE A COUPLE HUNDRED MILES OFF THE
COAST SOUTH OF GALVESTON IN THE NW GULF. CONVECTION HAS BEEN A BIT
MORE ORGANIZED AROUND AN ELONGATED CIRCULATION SEEN ON VIS
SATELLITE IMAGERY. WATER VAPOR IMAGERY CONTINUES TO SHOW QUITE A
BIT OF DRY AIR AROUND THE SYSTEM SO DO NOT SEE THERE BEING ANY
TROPICAL DEVELOPMENT AT ALL WITH THIS SYSTEM. UPPER AIR ANALYSIS
HAS UPPER LOW OVER THE ROCKIES WHICH HAS NOW PULLED INTO THE
PLAINS PER WATER VAPOR IMAGERY. SUSPECT THIS ALONG WITH
CYCLOGENESIS IN THE PLAINS WILL HELP TO TRY AND DRAW THE GULF
CIRCULATION TOWARDS THE COAST TONIGHT INTO TOMORROW. FORECAST WILL
KEEP SOME SMALL RAIN CHANCES ALONG THE COAST OVERNIGHT INTO TUE
BUT REALLY NOT EXPECTED MUCH PRECIP FOR INLAND AREAS.
UPPER LOW IN PLAINS SHOULD SHEAR OUT AND WEAKEN WITH THE NEGATIVE
TILT TOMORROW INTO WED. THIS DOES ALLOW FOR A PACIFIC FRONT TO
PUSH INTO THE AREA TOMORROW AND TUE NIGHT. THE MAIN EFFECT WILL BE
TO PROVIDE SOME DRIER AIR FOR THE AREA SO LOOKS LIKE MAYBE A
COUPLE MORE COOL MORNINGS BEFORE MOISTURE RETURN FLOW OFF THE GULF
STARTS IN EARNEST BY THE END OF THE WEEK.
UPPER LEVEL RIDGE SHOULD DEVELOP OVER THE AREA MID WEEK WITH A
BROAD TROUGH DEVELOPING OVER THE GREAT BASIN AND ROCKIES. THE
ECMWF/GFS/CANADIAN ARE IN A LITTLE MORE AGREEMENT WITH THIS
TROUGHS EVOLUTION AND THIS WILL BE KEY WITH REGARDS TO THIS
WEEKEND`S POTENTIAL COLD FRONT. UPPER TROUGH HAS ONE PIECE OF
VORTICITY THAT MOVES INTO THE N PLAINS ON THUR WITH THE MAIN
TROUGH LAGGING BACK OVER THE SIERRA NEVADAS ON THUR. THE MAIN
UPPER LOW LAGS BACK OVER THE 4 CORNERS REGION INTO SAT BEFORE
MOVING INTO THE PLAINS SAT NIGHT. THIS IS ABOUT 12-24 HRS SLOWER
THAN THE PREVIOUS MODEL RUNS AND SEEMS LIKE ALL MODELS ARE
TRENDING SLOWER WITH THE UPPER LOW. SO WITH THAT LOOKS LIKE THE
COLD FRONT WILL BE SLOWER TO MOVE INTO THE AREA. WILL STILL KEEP
30 POPS AS THERE WILL BE GOOD MOISTURE AND THINK CONVECTION SHOULD
DEVELOP FRI/SAT BUT BEST CHANCES STILL LOOK TO BE MORE ON SUNDAY.
COLD FRONT IS SET TO PUSH THROUGH DURING THE DAY SUN PER
GFS/ECMWF. MAIN PROBLEM WILL BE TO WATCH AND SEE IF THE FRONT
STALLS BEFORE REACHING THE COAST. THIS MAY BE A POSSIBILITY SINCE
THERE WILL BE SOME UPPER LEVEL RIDGING AND THE FRONT COULD BECOME
MORE ORIENTED PARALLEL TO MEAN UPPER FLOW. THINK THIS MAY BE MORE
THE CASE AND EXPECT TO SEE MODELS TREND IN THIS DIRECTION.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 69 93 67 93 67 / 10 10 10 10 10
HOUSTON (IAH) 72 93 68 94 68 / 10 10 10 10 10
GALVESTON (GLS) 78 90 76 90 78 / 20 20 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 1 AM CDT TUESDAY FOR
THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA
SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 1 AM CDT TUESDAY 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.
&&
$$
DISCUSSION...23
AVIATION/MARINE...43
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
119 PM CDT SUN SEP 22 2013
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...THE NEARLY STATIONARY SURFACE LOW SPINNING OVER NW
GULF OF MEX WILL MAINTAIN A FAIRLY DRY AND STABLE NORTHERLY LOW
LEVEL FLOW ACROSS THE LOWER RGV AIRPORTS THROUGHOUT THE NEXT 24
HOURS. SOME LINGERING RESIDUAL MOISTURE WILL PRODUCE SOME FAIR
WX CU THIS AFTERNOON AND TOMORROW AFTERNOON. HOWEVER EXPECT VFR
CEILINGS AND VSBYS TO PREVAIL THROUGH THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 635 AM CDT SUN SEP 22 2013/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...CEILINGS HAVE LIFTED TO AROUND 10KFT ACROSS THE
LOWER VALLEY. EXPECT THIS LAYER TO BREAK AND CLEAR OUT BY
THE EARLY MORNING HOURS WITH NORTHERLY WINDS INCREASING WITH
GUSTS UP 25 KNOTS POSSIBLE. THE LOW PRESSURE OVER THE GULF OF
MEXICO WILL CONTINUE TO SHIFT NORTHEAST WHICH WILL ALLOW FOR
WINDS TO DECOUPLE INTO THE EVENING. VFR CONDITIONS WILL PREVAIL
TONIGHT.
PREV DISCUSSION... /ISSUED 345 AM CDT SUN SEP 22 2013/
SHORT TERM /NOW THROUGH MONDAY/...UPPER LEVEL TROUGH MOVING
ACROSS NORTHERN CA INTO NEVADA WILL DEEPEN AND MIGRATE
EAST/SOUTHEAST INTO THE FOUR CORNERS REGION WHILE RIDGE BUILDS
OVER NORTH CENTRAL TEXAS. AN ELONGATED POSITIVE TILTED TROUGH OVER
THE TEXAS REGION WILL GRADUALLY SHIFT EASTWARD ADVECTING DRIER AIR
ACROSS SOUTH TEXAS FROM THE NORTH. SURFACE LOW OVER THE GULF
WATERS WILL STRENGTHEN THE GRADIENT ALONG THE RIO GRANDE VALLEY
AND KEEP A NORTH TO NORTHEAST FLOW ACROSS MUCH OF THE CWA TODAY.
WINDS WILL INCREASE BETWEEN 20 TO 25 MPH ESPECIALLY ALONG THE
COAST. AS DRIER AIR MOVES INTO S TEXAS...CLEAR SKIES WILL PREVAIL
ACROSS THE CWA WHILE AT THE COAST MOISTURE RAP AROUND THIS LOW
WILL INCREASE THE CLOUD COVER BETWEEN A FEW TO SCATTERED CLOUD
LAYER ALONG THE COAST. THE MOISTURE CONTENT WILL NOT BE VERY
SHALLOW WHICH WILL LIMIT CONVECTION TO DEVELOP. HIGH TEMPERATURES
TODAY WILL TREND 2 TO 3 DEG WARMER COMPARED TO YESTERDAYS
TEMPERATURES.
AS THIS LOW CONTINUES TO MOVE FURTHER FROM THE COAST OF TEXAS THIS
AFTERNOON..SFC GRADIENT WILL GRADUALLY RELAX AND REDUCE THE NORTH TO
NORTHEAST WINDS ACROSS THE AREA AND THE CHANCES OF RAIN LOWERS. A FEW
SHOWERS CAN NOT BE RULED OUT BUT WILL REMAIN OVER THE OFFSHORE WATERS
TODAY. TONIGHT...NORTHERLY FLOW WILL DIMINISH ACROSS THE CWA AN REMAIN
LIGHT AND VARIABLE DUE TO THE WEAKENING SURFACE GRADIENT. LOW TEMPS
WILL REMAIN WELL BELOW NORMAL...WITH THE WESTERN PORTION REACHING
THE MID TO UPPER 60S WHILE ALONG THE COAST REMAINING IN THE LOW 70S.
MONDAY...SURFACE LOW BEGINS TO MOVE PARALLEL TO THE TEXAS COAST INTO
THE NORTHWEST GULF WHILE DRIER AIR INDICATED BY THE NAM AND THE GFS
AT 1000 TO 500 MB RH LAYER MOVES INTO THE CWA FROM THE NORTHWEST. AS
THE DRY AIR INFILTRATES INTO THE CWA...THE CHANCE OR RAIN LOWERS
EVEN MORE TO LESS THAN 10 PERCENT ACROSS THE CWA. HIGH TEMPERATURES
WILL CONTINUE TO WARM INTO NEAR NORMAL TEMPERATURES FOR SEPTEMBER
WITH HIGHS NEAR THE MID 90S ALONG THE INTERNATIONAL BORDER. NORTH
WINDS WILL DECOUPLE QUICKLY AFTER SUNSET.
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...500MB TROUGH ACROSS
THE NORTH CENTRAL UNITED STATES MONDAY WILL SHIFT EASTWARD TUESDAY
AS A 500MB RIDGE BUILDS ACROSS THE SOUTHERN PLAINS. NORTHWEST FLOW
ALOFT WILL CONTINUE TO PROVIDE SUBSIDENCE ACROSS SOUTH TEXAS
TUESDAY INTO WEDNESDAY. LOW TO MID LEVEL MOISTURE IS EXPECTED TO
RETURN ACROSS THE RIO GRANDE VALLEY THURSDAY INTO FRIDAY AS A
500MB TROUGH DEVELOPS ACROSS THE WESTERN UNITED STATES AND THE
UPPER LEVEL RIDGE ACROSS TX SHIFTS EASTWARD. SURFACE LOW PRESSURE
IS PROGGED TO DEVELOP ACROSS THE CENTRAL PLAINS FRIDAY AHEAD OF
THE UPPER LEVEL TROUGH ACROSS THE WESTERN U.S. BRINGING A WEAK
COLD FRONT TOWARDS CENTRAL TX SATURDAY. THIS WILL PROVIDE A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE WEEKEND AS MOISTURE
POOLS ALONG AND AHEAD OF THE FRONT AS THE FRONT MOVES INTO SOUTH
TX SATURDAY INTO SUNDAY.
MARINE...
NOW THROUGH MONDAY...MARINE CONDITIONS REMAIN DETERIORATED FOR
MUCH OF THE SHORT TERM FORECAST. LATEST OBSERVATION SHOWS SEAS
BUILDING NEAR 9 FEET OVER THE GULF WATERS DUE TO THE SURFACE LOW
PRESSURE OVER THE GULF OF MX. THIS LOW WILL STRENGTHEN THE
GRADIENT ALONG THE GULF WATERS AND INCREASE WINDS BETWEEN 20 TO 25
KNOTS AND GUSTS UP TO 30 KNOTS AT TIMES. SEAS WILL BUILD TODAY
INCREASING CLOSE TO 10 FEET THROUGH THE DAY. THE SEAS BEGIN TO
LOWER OVER THE NEAR SHORE WATERS AS THE CENTER OF THE LOW BEGINS
TO MOVE FURTHER EAST EARLY TONIGHT. HOWEVER...A NORTHEAST FETCH
WILL KEEP SEAS HIGHER THROUGH THE EVENING OVER THE GULF SO THE SCA
HAS BEEN EXTENDED FOR THE WHOLE MARINE AREA WITH THE EXCEPTION OF
THE LAGUNA MADRE. ON THE BAY...CONDITIONS WILL BE MARGINAL TO
SMALL CRAFT ADVISORY BUT IT WILL LIKELY BE FOR AN HOUR AND QUICKLY
LOWER THE WINDS. THE NORTHEAST WINDS OVER THE OFFSHORE WATERS WILL
CONTINUE TO KEEP SEAS HIGH AS THE LOW PRESSURE MOVES NORTHWARD SO
EXTENDED THE SCA FOR THE OFFSHORE THROUGH MIDNIGHT. THE SEAS WILL
GRADUALLY LOWER TO SCEC BY EARLY MORNING MONDAY AND IMPROVE UNTIL
THE END OF THE DAY MONDAY WITH SEAS BETWEEN 2 TO 4 FEET. AN
ISOLATED SHOWER WILL BE POSSIBLE BUT WILL NOT LAST LONG AND
PRODUCE BRIEF DOWNPOURS.
MONDAY NIGHT THROUGH THURSDAY...LIGHT TO MODERATE NORTH TO
NORTHEAST WINDS ACROSS THE COASTAL WATERS MON NIGHT WILL BACK TO
THE WEST ON TUESDAY AS THE LOW PRESSURE ACROSS THE WESTERN GULF OF
MEXICO MOVES NORTHWARD. LIGHT WEST TO NORTHWEST WINDS SHOULD
PREVAIL ACROSS THE WESTERN GULF WEDNESDAY BEFORE FINALLY SHIFTING
TO THE SOUTHEAST ON THURSDAY AS LOW PRESSURE MOVES INTO THE
NORTHERN PLAINS AND THE LOW PRESSURE ACROSS THE NORTHERN GULF OF
MEXICO WEAKENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 72 87 72 91 / 10 10 0 0
BROWNSVILLE 70 90 70 92 / 10 10 0 0
HARLINGEN 69 90 70 94 / 10 10 0 0
MCALLEN 68 92 71 96 / 10 10 0 0
RIO GRANDE CITY 68 92 68 96 / 10 10 0 0
SOUTH PADRE ISLAND 74 85 75 87 / 10 10 0 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM CDT MONDAY FOR GMZ170-175.
SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR GMZ150-155.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
SHORT TERM...60
LONG TERM...55
GRAPHICAST/UPPER AIR...MARTINEZ
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
635 AM CDT SUN SEP 22 2013
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...CEILINGS HAVE LIFTED TO AROUND 10KFT ACROSS THE
LOWER VALLEY. EXPECT THIS LAYER TO BREAK AND CLEAR OUT BY
THE EARLY MORNING HOURS WITH NORTHERLY WINDS INCREASING WITH
GUSTS UP 25 KNOTS POSSIBLE. THE LOW PRESSURE OVER THE GULF OF
MEXICO WILL CONTINUE TO SHIFT NORTHEAST WHICH WILL ALLOW FOR
WINDS TO DECOUPLE INTO THE EVENING. VFR CONDITIONS WILL PREVAIL
TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 345 AM CDT SUN SEP 22 2013/
SHORT TERM /NOW THROUGH MONDAY/...UPPER LEVEL TROUGH MOVING
ACROSS NORTHERN CA INTO NEVADA WILL DEEPEN AND MIGRATE
EAST/SOUTHEAST INTO THE FOUR CORNERS REGION WHILE RIDGE BUILDS
OVER NORTH CENTRAL TEXAS. AN ELONGATED POSITIVE TILTED TROUGH OVER
THE TEXAS REGION WILL GRADUALLY SHIFT EASTWARD ADVECTING DRIER AIR
ACROSS SOUTH TEXAS FROM THE NORTH. SURFACE LOW OVER THE GULF
WATERS WILL STRENGTHEN THE GRADIENT ALONG THE RIO GRANDE VALLEY
AND KEEP A NORTH TO NORTHEAST FLOW ACROSS MUCH OF THE CWA TODAY.
WINDS WILL INCREASE BETWEEN 20 TO 25 MPH ESPECIALLY ALONG THE
COAST. AS DRIER AIR MOVES INTO S TEXAS...CLEAR SKIES WILL PREVAIL
ACROSS THE CWA WHILE AT THE COAST MOISTURE RAP AROUND THIS LOW
WILL INCREASE THE CLOUD COVER BETWEEN A FEW TO SCATTERED CLOUD
LAYER ALONG THE COAST. THE MOISTURE CONTENT WILL NOT BE VERY
SHALLOW WHICH WILL LIMIT CONVECTION TO DEVELOP. HIGH TEMPERATURES
TODAY WILL TREND 2 TO 3 DEG WARMER COMPARED TO YESTERDAYS
TEMPERATURES.
AS THIS LOW CONTINUES TO MOVE FURTHER FROM THE COAST OF TEXAS THIS
AFTERNOON..SFC GRADIENT WILL GRADUALLY RELAX AND REDUCE THE NORTH TO
NORTHEAST WINDS ACROSS THE AREA AND THE CHANCES OF RAIN LOWERS. A FEW
SHOWERS CAN NOT BE RULED OUT BUT WILL REMAIN OVER THE OFFSHORE WATERS
TODAY. TONIGHT...NORTHERLY FLOW WILL DIMINISH ACROSS THE CWA AN REMAIN
LIGHT AND VARIABLE DUE TO THE WEAKENING SURFACE GRADIENT. LOW TEMPS
WILL REMAIN WELL BELOW NORMAL...WITH THE WESTERN PORTION REACHING
THE MID TO UPPER 60S WHILE ALONG THE COAST REMAINING IN THE LOW 70S.
MONDAY...SURFACE LOW BEGINS TO MOVE PARALLEL TO THE TEXAS COAST INTO
THE NORTHWEST GULF WHILE DRIER AIR INDICATED BY THE NAM AND THE GFS
AT 1000 TO 500 MB RH LAYER MOVES INTO THE CWA FROM THE NORTHWEST. AS
THE DRY AIR INFILTRATES INTO THE CWA...THE CHANCE OR RAIN LOWERS
EVEN MORE TO LESS THAN 10 PERCENT ACROSS THE CWA. HIGH TEMPERATURES
WILL CONTINUE TO WARM INTO NEAR NORMAL TEMPERATURES FOR SEPTEMBER
WITH HIGHS NEAR THE MID 90S ALONG THE INTERNATIONAL BORDER. NORTH
WINDS WILL DECOUPLE QUICKLY AFTER SUNSET.
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...500MB TROUGH ACROSS
THE NORTH CENTRAL UNITED STATES MONDAY WILL SHIFT EASTWARD TUESDAY
AS A 500MB RIDGE BUILDS ACROSS THE SOUTHERN PLAINS. NORTHWEST FLOW
ALOFT WILL CONTINUE TO PROVIDE SUBSIDENCE ACROSS SOUTH TEXAS
TUESDAY INTO WEDNESDAY. LOW TO MID LEVEL MOISTURE IS EXPECTED TO
RETURN ACROSS THE RIO GRANDE VALLEY THURSDAY INTO FRIDAY AS A
500MB TROUGH DEVELOPS ACROSS THE WESTERN UNITED STATES AND THE
UPPER LEVEL RIDGE ACROSS TX SHIFTS EASTWARD. SURFACE LOW PRESSURE
IS PROGGED TO DEVELOP ACROSS THE CENTRAL PLAINS FRIDAY AHEAD OF
THE UPPER LEVEL TROUGH ACROSS THE WESTERN U.S. BRINGING A WEAK
COLD FRONT TOWARDS CENTRAL TX SATURDAY. THIS WILL PROVIDE A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE WEEKEND AS MOISTURE
POOLS ALONG AND AHEAD OF THE FRONT AS THE FRONT MOVES INTO SOUTH
TX SATURDAY INTO SUNDAY.
MARINE...
NOW THROUGH MONDAY...MARINE CONDITIONS REMAIN DETERIORATED FOR
MUCH OF THE SHORT TERM FORECAST. LATEST OBSERVATION SHOWS SEAS
BUILDING NEAR 9 FEET OVER THE GULF WATERS DUE TO THE SURFACE LOW
PRESSURE OVER THE GULF OF MX. THIS LOW WILL STRENGTHEN THE
GRADIENT ALONG THE GULF WATERS AND INCREASE WINDS BETWEEN 20 TO 25
KNOTS AND GUSTS UP TO 30 KNOTS AT TIMES. SEAS WILL BUILD TODAY
INCREASING CLOSE TO 10 FEET THROUGH THE DAY. THE SEAS BEGIN TO
LOWER OVER THE NEAR SHORE WATERS AS THE CENTER OF THE LOW BEGINS
TO MOVE FURTHER EAST EARLY TONIGHT. HOWEVER...A NORTHEAST FETCH
WILL KEEP SEAS HIGHER THROUGH THE EVENING OVER THE GULF SO THE SCA
HAS BEEN EXTENDED FOR THE WHOLE MARINE AREA WITH THE EXCEPTION OF
THE LAGUNA MADRE. ON THE BAY...CONDITIONS WILL BE MARGINAL TO
SMALL CRAFT ADVISORY BUT IT WILL LIKELY BE FOR AN HOUR AND QUICKLY
LOWER THE WINDS. THE NORTHEAST WINDS OVER THE OFFSHORE WATERS WILL
CONTINUE TO KEEP SEAS HIGH AS THE LOW PRESSURE MOVES NORTHWARD SO
EXTENDED THE SCA FOR THE OFFSHORE THROUGH MIDNIGHT. THE SEAS WILL
GRADUALLY LOWER TO SCEC BY EARLY MORNING MONDAY AND IMPROVE UNTIL
THE END OF THE DAY MONDAY WITH SEAS BETWEEN 2 TO 4 FEET. AN
ISOLATED SHOWER WILL BE POSSIBLE BUT WILL NOT LAST LONG AND
PRODUCE BRIEF DOWNPOURS.
MONDAY NIGHT THROUGH THURSDAY...LIGHT TO MODERATE NORTH TO
NORTHEAST WINDS ACROSS THE COASTAL WATERS MON NIGHT WILL BACK TO
THE WEST ON TUESDAY AS THE LOW PRESSURE ACROSS THE WESTERN GULF OF
MEXICO MOVES NORTHWARD. LIGHT WEST TO NORTHWEST WINDS SHOULD
PREVAIL ACROSS THE WESTERN GULF WEDNESDAY BEFORE FINALLY SHIFTING
TO THE SOUTHEAST ON THURSDAY AS LOW PRESSURE MOVES INTO THE
NORTHERN PLAINS AND THE LOW PRESSURE ACROSS THE NORTHERN GULF OF
MEXICO WEAKENS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM CDT MONDAY FOR GMZ170-175.
SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR GMZ150-155.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
67/61
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
345 AM CDT SUN SEP 22 2013
.SHORT TERM /NOW THROUGH MONDAY/...UPPER LEVEL TROUGH MOVING
ACROSS NORTHERN CA INTO NEVADA WILL DEEPEN AND MIGRATE
EAST/SOUTHEAST INTO THE FOUR CORNERS REGION WHILE RIDGE BUILDS
OVER NORTH CENTRAL TEXAS. AN ELONGATED POSITIVE TILTED TROUGH OVER
THE TEXAS REGION WILL GRADUALLY SHIFT EASTWARD ADVECTING DRIER AIR
ACROSS SOUTH TEXAS FROM THE NORTH. SURFACE LOW OVER THE GULF
WATERS WILL STRENGTHEN THE GRADIENT ALONG THE RIO GRANDE VALLEY
AND KEEP A NORTH TO NORTHEAST FLOW ACROSS MUCH OF THE CWA TODAY.
WINDS WILL INCREASE BETWEEN 20 TO 25 MPH ESPECIALLY ALONG THE
COAST. AS DRIER AIR MOVES INTO S TEXAS...CLEAR SKIES WILL PREVAIL
ACROSS THE CWA WHILE AT THE COAST MOISTURE RAP AROUND THIS LOW
WILL INCREASE THE CLOUD COVER BETWEEN A FEW TO SCATTERED CLOUD
LAYER ALONG THE COAST. THE MOISTURE CONTENT WILL NOT BE VERY
SHALLOW WHICH WILL LIMIT CONVECTION TO DEVELOP. HIGH TEMPERATURES
TODAY WILL TREND 2 TO 3 DEG WARMER COMPARED TO YESTERDAYS
TEMPERATURES.
AS THIS LOW CONTINUES TO MOVE FURTHER FROM THE COAST OF TEXAS THIS
AFTERNOON..SFC GRADIENT WILL GRADUALLY RELAX AND REDUCE THE NORTH TO
NORTHEAST WINDS ACROSS THE AREA AND THE CHANCES OF RAIN LOWERS. A FEW
SHOWERS CAN NOT BE RULED OUT BUT WILL REMAIN OVER THE OFFSHORE WATERS
TODAY. TONIGHT...NORTHERLY FLOW WILL DIMINISH ACROSS THE CWA AN REMAIN
LIGHT AND VARIABLE DUE TO THE WEAKENING SURFACE GRADIENT. LOW TEMPS
WILL REMAIN WELL BELOW NORMAL...WITH THE WESTERN PORTION REACHING
THE MID TO UPPER 60S WHILE ALONG THE COAST REMAINING IN THE LOW 70S.
MONDAY...SURFACE LOW BEGINS TO MOVE PARALLEL TO THE TEXAS COAST INTO
THE NORTHWEST GULF WHILE DRIER AIR INDICATED BY THE NAM AND THE GFS
AT 1000 TO 500 MB RH LAYER MOVES INTO THE CWA FROM THE NORTHWEST. AS
THE DRY AIR INFILTRATES INTO THE CWA...THE CHANCE OR RAIN LOWERS
EVEN MORE TO LESS THAN 10 PERCENT ACROSS THE CWA. HIGH TEMPERATURES
WILL CONTINUE TO WARM INTO NEAR NORMAL TEMPERATURES FOR SEPTEMBER
WITH HIGHS NEAR THE MID 90S ALONG THE INTERNATIONAL BORDER. NORTH
WINDS WILL DECOUPLE QUICKLY AFTER SUNSET.
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...500MB TROUGH ACROSS
THE NORTH CENTRAL UNITED STATES MONDAY WILL SHIFT EASTWARD TUESDAY
AS A 500MB RIDGE BUILDS ACROSS THE SOUTHERN PLAINS. NORTHWEST FLOW
ALOFT WILL CONTINUE TO PROVIDE SUBSIDENCE ACROSS SOUTH TEXAS
TUESDAY INTO WEDNESDAY. LOW TO MID LEVEL MOISTURE IS EXPECTED TO
RETURN ACROSS THE RIO GRANDE VALLEY THURSDAY INTO FRIDAY AS A
500MB TROUGH DEVELOPS ACROSS THE WESTERN UNITED STATES AND THE
UPPER LEVEL RIDGE ACROSS TX SHIFTS EASTWARD. SURFACE LOW PRESSURE
IS PROGGED TO DEVELOP ACROSS THE CENTRAL PLAINS FRIDAY AHEAD OF
THE UPPER LEVEL TROUGH ACROSS THE WESTERN U.S. BRINGING A WEAK
COLD FRONT TOWARDS CENTRAL TX SATURDAY. THIS WILL PROVIDE A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE WEEKEND AS MOISTURE
POOLS ALONG AND AHEAD OF THE FRONT AS THE FRONT MOVES INTO SOUTH
TX SATURDAY INTO SUNDAY.
&&
.MARINE...
NOW THROUGH MONDAY...MARINE CONDITIONS REMAIN DETERIORATED FOR
MUCH OF THE SHORT TERM FORECAST. LATEST OBSERVATION SHOWS SEAS
BUILDING NEAR 9 FEET OVER THE GULF WATERS DUE TO THE SURFACE LOW
PRESSURE OVER THE GULF OF MX. THIS LOW WILL STRENGTHEN THE
GRADIENT ALONG THE GULF WATERS AND INCREASE WINDS BETWEEN 20 TO 25
KNOTS AND GUSTS UP TO 30 KNOTS AT TIMES. SEAS WILL BUILD TODAY
INCREASING CLOSE TO 10 FEET THROUGH THE DAY. THE SEAS BEGIN TO
LOWER OVER THE NEAR SHORE WATERS AS THE CENTER OF THE LOW BEGINS
TO MOVE FURTHER EAST EARLY TONIGHT. HOWEVER...A NORTHEAST FETCH
WILL KEEP SEAS HIGHER THROUGH THE EVENING OVER THE GULF SO THE SCA
HAS BEEN EXTENDED FOR THE WHOLE MARINE AREA WITH THE EXCEPTION OF
THE LAGUNA MADRE. ON THE BAY...CONDITIONS WILL BE MARGINAL TO
SMALL CRAFT ADVISORY BUT IT WILL LIKELY BE FOR AN HOUR AND QUICKLY
LOWER THE WINDS. THE NORTHEAST WINDS OVER THE OFFSHORE WATERS WILL
CONTINUE TO KEEP SEAS HIGH AS THE LOW PRESSURE MOVES NORTHWARD SO
EXTENDED THE SCA FOR THE OFFSHORE THROUGH MIDNIGHT. THE SEAS WILL
GRADUALLY LOWER TO SCEC BY EARLY MORNING MONDAY AND IMPROVE UNTIL
THE END OF THE DAY MONDAY WITH SEAS BETWEEN 2 TO 4 FEET. AN
ISOLATED SHOWER WILL BE POSSIBLE BUT WILL NOT LAST LONG AND
PRODUCE BRIEF DOWNPOURS.
MONDAY NIGHT THROUGH THURSDAY...LIGHT TO MODERATE NORTH TO
NORTHEAST WINDS ACROSS THE COASTAL WATERS MON NIGHT WILL BACK TO
THE WEST ON TUESDAY AS THE LOW PRESSURE ACROSS THE WESTERN GULF OF
MEXICO MOVES NORTHWARD. LIGHT WEST TO NORTHWEST WINDS SHOULD
PREVAIL ACROSS THE WESTERN GULF WEDNESDAY BEFORE FINALLY SHIFTING
TO THE SOUTHEAST ON THURSDAY AS LOW PRESSURE MOVES INTO THE
NORTHERN PLAINS AND THE LOW PRESSURE ACROSS THE NORTHERN GULF OF
MEXICO WEAKENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 84 72 87 72 / 10 10 10 0
BROWNSVILLE 86 70 90 70 / 10 10 10 0
HARLINGEN 87 69 90 70 / 10 10 10 0
MCALLEN 89 68 92 71 / 10 10 10 0
RIO GRANDE CITY 89 68 92 68 / 10 10 10 0
SOUTH PADRE ISLAND 83 74 85 75 / 10 10 10 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM CDT MONDAY FOR GMZ170-175.
SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR GMZ150-155.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
67/61/VEGA
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
657 PM CDT MON SEP 23 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 258 PM CDT MON SEP 23 2013
AFTERNOON WATER VAPOR IMAGERY OVERLAID WITH RAP 500 MB ANALYSIS
SHOWS RATHER DEEP NEGATIVELY TITLED UPPER LEVEL SHORTWAVE TROUGH
EJECTING OUT INTO THE CENTRAL PLAINS. AT THE SURFACE...A 997 MB
LOW RESIDES IN NW KANSAS WITH A NICE CURL SEEN IN VISIBLE
SATELLITE IMAGERY. IT IS THIS SYSTEM THAT WILL BE LIFTING TOWARD
THE UPPER MIDWEST TONIGHT INTO TUESDAY.
23.12Z GUIDANCE REMAINS SUPPORTIVE OF A DRY FORECAST WITH THIS
SYSTEM AS A COMBINATION OF WEAKENING DYNAMICS AND LIMITED
MOISTURE TRANSPORT LEAVES A LOT TO BE DESIRED. ACROSS THE
BOARD...500-300 MB PV ADVECTION...300-310K ISENTROPIC LIFT...AND
850 MB MOISTURE TRANSPORT ALL WEAKEN OR BECOME NON-EXISTENT
BETWEEN 06Z AND 15Z TUESDAY. OUTSIDE OF MID TO HIGH LEVEL CLOUDS
SPREADING IN FROM THE WEST INITIALLY WITH THE WARM AIR ADVECTION
WING...LITTLE TO NO IMPACT EXPECTED WITH THIS SYSTEM. PLAN ON
ANOTHER PLEASANT AUTUMN DAY WITH MOSTLY TO PARTLY SUNNY SKIES AND
HIGHS A COUPLE DEGREES ON EITHER SIDE OF 70F.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 258 PM CDT MON SEP 23 2013
DRY/QUIET WEATHER TUESDAY NIGHT THROUGH FRIDAY AS RIDGE OF HIGH
PRESSURE INFLUENCES THE SENSIBLE WEATHER ACROSS THE UPPER MIDWEST.
BY WEDNESDAY...THE AFOREMENTIONED SYSTEM DECAYS AND SLOWS ACROSS
THE MID ATLANTIC MEANWHILE A WESTERN CONUS SHORTWAVE TROUGH DIGS
DOWN NEAR THE FOUR CORNERS REGION. THIS PUTS THE CENTRAL PLAINS
UNDER DRY...WARMING SOUTHWESTERLY FLOW. 925 MB TEMPERATURES ARE
EXPECTED TO CLIMB EACH DAY...FROM NEAR SEASONAL LEVELS WEDNESDAY
TO SLIGHTLY ABOVE NORMAL BY THURSDAY...AND TO NEAR 80 IN SOME
SPOTS BY FRIDAY.
WEDNESDAY MORNING CONDITIONS LOOK SOMEWHAT FAVORABLE FOR RIVER
VALLEY FOG AS HIGH PRESSURE CENTERS ITSELF ACROSS CENTRAL
WISCONSIN. FORECAST SOUNDINGS SHOW A VERY DEEP LAYER OF LIGHT
WINDS LESS THAN 10 KTS UP TO 600 MB...THOUGH THERE IS A LACK OF
LOW LEVEL SATURATION...BUT COULD BE ENOUGH TO PATCHY RIVER VALLEY
FOG. THE OTHER COMPETING FACTOR IS THE POSSIBILITY OF A
NORTH/SOUTH ORIENTED MID LEVEL STRATUS DECK SETTING UP ALONG OR
JUST WEST OF THE MS RIVER. THIS IS SEEN IN THE GFS/NAM RH FIELDS
AT 850 AND 700 MB. FOR NOW...HAVE ADDED PATCHY VALLEY FOG TO MS
AND WISCONSIN RIVER VALLEYS.
FOCUS TURNS TO LATE FRIDAY NIGHT INTO THE UPCOMING WEEKEND SYSTEM
AS THE WESTERN SHORTWAVE TROUGH MOVES INTO THE NORTHERN AND
CENTRAL PLAINS. AS PIECES OF ENERGY ROUND THE SHORTWAVE TROUGH...A
COUPLE OF SURFACE LOWS ARE EXPECTED TO FORM...AND EVENTUALLY DRAG
A COLD FRONT THROUGH THE AREA. MOISTURE AHEAD OF THE FRONT
INCREASES...AND BROAD BUT PERSISTENT ISENTROPIC LIFT ON THE
305-315K SURFACES IS SEEN. THERE IS WEAK INSTABILITY ASSOCIATED
WITH THE SYSTEM...BUT MOST OF THE PRECIPITATION LOOKS TO BE POST-
FRONTAL. THE POSITIVE TILTED NATURE OF THE SHORTWAVE TROUGH MAKES
TIMING DETAILS A BIT UNCERTAIN AND DIFFICULT...AS THERE REMAINS
SOME DISAGREEMENT BETWEEN THE 23.12Z GUIDANCE. HOWEVER...ALL
GUIDANCE DID TREND MUCH SLOWER THAN PREVIOUS RUNS...THOUGH WITH
VARYING DEGREES. THE GEM/ECMWF SUGGESTS MOST OF SATURDAY WOULD
REMAIN DRY...HOLDING PRECIPITATION BACK UNTIL SATURDAY NIGHT OR
SUNDAY. THE GFS IS A TOUCH FASTER BUT STILL SLOWER THAN ITS
PREVIOUS RUN. AS A RESULT...HAVE PUSHED BACK PRECIPITATION
TIMING...ESPECIALLY EAST OF THE MISSISSIPPI RIVER. STILL PLENTY OF
TIME TO IRON OUT THE SPECIFICS. IN THE WAKE OF THIS SYSTEM...A
RETURN TO SEASONABLY COOL AND DRY WEATHER THANKS TO CANADIAN HIGH
PRESSURE BUILDING INTO THE UPPER MIDWEST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 657 PM CDT MON SEP 23 2013
STRETCH OF NIL AVIATION WEATHER CONTINUES TONIGHT WITH HIGH PRESSURE
RIDGE OVER GREAT LAKES AND DRY AIRMASS IN PLACE. FOCUS HAS BEEN ON
SLOWLY APPROACHING STACKED UPPER LOW THAT IS MOVING THROUGH
NEBRASKA. MODEL GUIDANCE CONTINUES TO WEAKEN THIS SYSTEM AS IT
APPROACHES SO ONLY CONCERN IS IF AND WHEN DEBRIS CLOUDS MIGHT GET
INTO AREA ON TUESDAY. INTRODUCED SOME CEILINGS IN PARTS OF MINNESOTA
AND IOWA LATE IN PERIOD /TUESDAY AFTERNOON/ BUT STILL SHOULD BE VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZT
LONG TERM....ZT
AVIATION.....SHEA
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
209 PM CDT SUN SEP 22 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 209 PM CDT SUN SEP 22 2013
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POTENT SHORTWAVE TROUGH OVER UTAH AND ARIZONA...WHILE
RIDGING WAS STRENGTHENING DOWNSTREAM FROM TEXAS INTO MINNESOTA. THE
FORECAST AREA LIES ON THE EAST SIDE OF THE RIDGE...FAVORING
SUBSIDENCE...DRY CONDITIONS AND HIGH PRESSURE. 12Z GRB...DVN AND MPX
SOUNDINGS HAD PRECIPITABLE WATER VALUES OF 0.4-0.65 INCHES...
ANYWHERE FROM 50-100 PERCENT OF NORMAL. THE DRY AIR HAS ALLOWED FOR
SUNNY SKIES ACROSS THE AREA. TEMPERATURES VARY GREATLY ACROSS THE
FORECAST AREA...RESULTING FROM 12Z 925MB TEMPS RANGING FROM 4C AT
GRB TO 11C AT MPX AND DVN. READINGS RANGE FROM THE UPPER 50S AT
MEDFORD TO LOW 70S IN FAR WESTERN PORTIONS OF THE FORECAST AREA.
WINDS ARE INCREASING JUST OFF TO THE WEST OVER THE PLAINS AND
MINNESOTA...AHEAD OF LEE TROUGHING. WARMER AIR IS ACCOMPANYING THE
STRONGER WINDS WITH 925MB TEMPS AT 12Z OF 16C AT ABR AND 20C AT OAX.
SYNOPTIC OVERVIEW...
THE POTENT SHORTWAVE TROUGH IN THE SOUTHWESTERN U.S. IS PROGGED TO
LIFT UP INTO SOUTH DAKOTA AND NEBRASKA BY 00Z TUESDAY. THE APPROACH
OF THE TROUGH WILL HELP STRENGTHEN AND AMPLIFY THE RIDGE AS IT
PUSHES EAST INTO MICHIGAN BY 00Z.
DETAILS...
DRY CONDITIONS ARE GOING TO CONTINUE DESPITE AN INCREASE OF
SOUTHERLY WINDS OVER THE NEXT 24 HOURS. IN FACT...THERE ARE
INDICATIONS THAT PRECIPITABLE WATER VALUES WILL EVEN FALL AS DRY AIR
CENTERED OVER THE OZARKS AREA GETS ADVECTED NORTH ON THE SOUTH
WINDS. THE INCREASING PRESSURE GRADIENT AND SOUTH WINDS OVER THE
AREA TONIGHT WILL LIMIT BOTH TEMPERATURE FALL AND VALLEY FOG
POTENTIAL TONIGHT. COLDEST READINGS ARE EXPECTED TOWARDS CENTRAL
WISCONSIN WHERE GRADIENT IS LIGHTEST...WITH LOWS IN THE UPPER 30S.
MAYBE SOME VALLEY FOG CAN FORM IN THE WISCONSIN RIVER VALLEY BECAUSE
OF THE WIND BEING ORTHAGONAL TO THE VALLEY. COMBINATION OF DRIER
AIR...925MB TEMPS RANGING FROM 12C EAST TO 15C WEST AT 18Z
MONDAY...AND SOUTHERLY BREEZE SHOULD ALLOW TEMPERATURES TO CLIMB
INTO THE UPPER 60S TO LOW 70S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 209 PM CDT SUN SEP 22 2013
FIRST ITEM OF INTEREST IS THE SHORTWAVE TROUGH OVER SOUTH DAKOTA AND
NEBRASKA ON MONDAY. MODELS ARE IN GOOD AGREEMENT OF THE TROUGH
WEAKENING AS IT GETS LIFTED TOWARDS THE FORECAST AREA ON
TUESDAY...IN RESPONSE TO RUNNING INTO THE RIDGING AHEAD OF IT. WITH
THE TROUGH WEAKENING...THE 850MB MOISTURE TRANSPORT ACCOMPANYING IT
ALSO BEGINS TO FALL APART. HOW QUICK THE WEAKENING OF THE TROUGH AND
ASSOCIATED 850MB MOISTURE TRANSPORT OCCURS WILL DETERMINE WHETHER
ANY PRECIPITATION GETS INTO THE FORECAST AREA. THE 22.12Z GFS
CONTINUES TO SUGGEST THE TROUGH WILL STILL BE STRONG ENOUGH TO BRING
SOME SHOWERS TUESDAY AFTERNOON AND EVENING TO LOCATIONS WEST OF THE
MS RIVER. MEANWHILE THE 22.12Z NAM/CANADIAN/UKMET AND 22.00Z/12Z ECMWF
ARE ALL DRY DUE TO THEM WEAKENING THE TROUGH AND MOISTURE
TRANSPORT QUICKER. MODEL CONSENSUS WOULD POINT TO A DRY
FORECAST...BUT HONORED THE GFS AND PREVIOUS FORECAST WITH 20
PERCENT CHANCES WEST OF THE MS RIVER FOR TUESDAY AFTERNOON.
ANOTHER UPPER RIDGE IS FORECAST TO COME IN BEHIND THE TUESDAY TROUGH
BECAUSE OF A VERY DEEP TROUGH PROGGED TO FORM OVER THE WESTERN U.S.
ON WEDNESDAY. 500MB STANDARDIZED ANOMALIES OVER NEVADA AND
CALIFORNIA AT 00Z THU ARE 3 BELOW NORMAL. HEADING THROUGH THURSDAY
AND FRIDAY...THE TROUGH BEGINS TO LIFT OUT INTO THE NORTHERN
PLAINS...MOST LIKELY IN A POSITIVE TILT...CAUSING A HIGHLY AMPLIFIED
RIDGE TO DEVELOP OVER THE WESTERN GREAT LAKES REGION. SUBSIDENCE
WITH THIS RIDGE WILL KEEP THE FORECAST AREA DRY WEDNESDAY THROUGH
FRIDAY. EXPECT INCREASING SOUTHERLY WINDS AHEAD OF THE TROUGH TO
BRING WARMER AIR TO THE AREA AS WELL...WITH 925MB TEMPS PROGGED TO
CLIMB TO 14-17C ON WEDNESDAY AND THURSDAY...THEN TO 16-19C ON
FRIDAY. DPVA FORCING WITH THE TROUGH SHOULD APPROACH THE AREA FRIDAY
NIGHT...ALONG WITH A SURFACE COLD FRONT. ALL INDICATIONS ARE THAT
THE SOUTHERN PORTION OF THE TROUGH AND COLD FRONT WILL PASS THROUGH
THE FORECAST AREA EITHER SATURDAY OR SATURDAY NIGHT. ONCE THE TROUGH
AXIS PASSES...THE PRECIPITATION WILL END. PLAN ON A COOLER SATURDAY
DUE TO THE COMBINATION OF THE FRONTAL PASSAGE AND PRECIPITATION.
FOR SUNDAY AND EVEN HEADING INTO NEXT WEEK...GOOD MODEL CONTINUITY
EXISTS OF RIDGING STRENGTHENING ACROSS THE WESTERN U.S. AND INTO
SOUTHWEST CANADA. THIS WILL EVENTUALLY SET UP SOME TROUGHING
DOWNSTREAM OVER THE GREAT LAKES REGION. THE 22.12Z ECMWF IS VERY
QUICK AT DEVELOPING THIS TROUGHING...PHASING THE SOUTHERN PORTION OF
THE TROUGH ON SATURDAY WITH TROUGHING TRYING TO SET UP OVER THE
GREAT LAKES REGION. THE RESULT IS A WOUND UP LOW NEAR CHICAGO AT 12Z
SUNDAY. DO NOT HAVE MUCH CONFIDENCE OF THIS OCCURRING...BEING A
PHASING SCENARIO...THUS HAVE WENT WITH THE IDEA OF DRYING COMING IN
BEHIND THE SOUTHERN PORTION OF THE TROUGH. TEMPERATURES LOOK TO BE
JUST SLIGHTLY COOLER ON SUNDAY AS 925MB TEMPS FALL TO 10-13C.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1229 PM CDT SUN SEP 22 2013
HIGH PRESSURE WILL BE THE DOMINANT WEATHER FEATURE THROUGH MONDAY.
PRESSURE GRADIENT BETWEEN THE SURFACE HIGH CENTERED OVER THE GREAT
LAKES REGION AND AN AREA OF LOW PRESSURE MOVING INTO THE HIGH PLAINS
WILL PRODUCE SOUTHEAST WINDS IN THE 7-11KT RANGE THROUGH TONIGHT AND
IN THE 12-16KT RANGE BY LATER MONDAY MORNING WITH SOME HIGHER GUSTS.
WINDS OVERNIGHT SHOULD PREVENT FOG FORMATION IN THE MISSISSIPPI
RIVER VALLEY/KLSE TAF SITE...BUT MAY HAVE TO KEEP AN EYE ON THIS. IF
WINDS DO DECOUPLE MORE IN THE MISSISSIPPI RIVER VALLEY...SOME RIVER
FOG/STRATUS WILL BE POSSIBLE...BUT RIGHT NOW THIS HIGHLY DOUBTFUL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1146 PM MDT MON SEP 23 2013
.UPDATE...
ISSUED AT 707 PM MDT MON SEP 23 2013
UPDATED TO EXPIRE THE WIND ADVISORY AND HIGH WIND WARNING ACROSS
THE FORECAST AREA. THE WINDS SHOULD CONTINUE TO DIMINISH ACROSS
THE REGION OVERNIGHT AND THROUGH THE DAY ON TUESDAY AS THE LOW
PRESSURE AREA MOVES EAST AND IS REPLACED BY HIGH PRESSURE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 239 PM MDT MON SEP 23 2013
UPPER FLOW WILL BE NORTHWEST TONIGHT AND TUESDAY AS THE UPPER LOW
MOVES NORTHEAST INTO IOWA. SURFACE HIGH PRESSURE WILL MOVE INTO THE
CENTRAL PLAINS.
AS THE UPPER LOW LIFTS OUTS THIS EVENING ANY REMAINING SHOWERS WILL
EXIT THE FA. SUBSIDENCE WILL FOLLOW AND CONTINUE THROUGH TUESDAY.
OTHER THAN SOME SLIGHT CHANCE POPS EARLY THIS EVENING, POPS WILL BE
NIL FOR THE REMAINDER OF THIS PART OF THE FORECAST.
HRRR AND RUC MODELS INDICATE STRONG WINDS WILL CONTINUE UNTIL AROUND
01Z. PLAN TO CONTINUE HIGH WIND WARNING AND WIND ADVISORY UNTIL 01Z
TUESDAY. GUSTY NORTHWEST WIND WILL DECREASE AROUND SUNSET.
MIN TEMPERATURES WILL BE COOL TONIGHT WITH READINGS RANGING FROM THE
MID 40S IN EASTERN COLORADO TO AROUND 50 IN THE EASTERN FA. MAX
TEMPERATURES TUESDAY WILL WARM INTO THE MID/UPPER 70S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 239 PM MDT MON SEP 23 2013
A BRIEF PERIOD OF SHORTWAVE RIDGING WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY...LEADING TO DRY WEATHER. AS STATED ABOVE...BRIEF IS THE
KEY WORD AS THE NEXT LARGE TROUGH OF LOW PRESSURE DEVELOPS OVER THE
WESTERN UNITED STATES AND HEADS EAST. AHEAD OF THE UPPER LEVEL
TROUGH...A WARMING TREND IS FORECAST UNDER A WARM AIR ADVECTION
REGIME OF SOUTH WINDS. HIGH TEMPERATURES ARE EXPECTED TO CLIMB INTO
THE MID 80S ON WEDNESDAY AND MID TO UPPER 80S...POSSIBLY NEAR
90...ON THURSDAY. ALSO...PRESSURE GRADIENTS ARE EXPECTED TO TIGHTEN
ON WEDNESDAY WHICH WILL RESULT IN A PERIOD OF BREEZY TO POSSIBLY
WINDY CONDITIONS DURING THE DAY AND EARLY EVENING. A LEE TROUGH IS
INDICATED BY MODELS TO MOVE IN ON THURSDAY...BRINGING A WIND SHIFT
AND COOLER TEMPERATURES TO NORTHEAST COLORADO. AHEAD OF THE LEE
TROUGH...IT IS POSSIBLE A FEW SHOWERS...POSSIBLY A
THUNDERSTORM...COULD DEVELOP FOR THURSDAY AFTERNOON AND THURSDAY
NIGHT.
AS THE UPPER LEVEL TROUGH EJECTS ACROSS THE NORTHERN PLAINS...A COLD
FRONT WILL BE FORCED DOWN ACROSS THE TRI-STATE AREA. THERE ARE SOME
LARGE TIMING DIFFERENCES BETWEEN MODELS AT THE PRESENT
TIME...LEADING TO WIND AND TEMPERATURE FIELDS LACKING IN AGREEMENT
AS WELL. THEREFORE...DID NOT STRAY TOO MUCH FROM THE MIDDLE GROUND
OF THE MODELS FOR THIS NEXT SYSTEM. THE MIDDLE GROUND PLACES FRONTAL
PASSAGE EARLY IN THE DAY ON FRIDAY. EITHER WAY...THERE WILL BE
A GOOD CHANCE FOR SHOWERS AND POSSIBLY A FEW RUMBLES OF THUNDER FOR
FRIDAY NIGHT BEHIND THE FRONT. A FEW ISOLATED SHOWERS AND STORMS ARE
POSSIBLE AHEAD OF THE FRONT BUT THE MAJORITY OF THE ACTIVITY SHOULD
STAY TO THE SOUTHEAST WHERE INSTABILITY IS PROJECTED TO BE HIGHER.
IN ADDITION...TEMPERATURES COOL DRAMATICALLY AGAIN BEHIND THE COLD
FRONT. HIGH TEMPERATURES ON FRIDAY WILL RANGE FROM THE LOW 60S TO
THE UPPER 70S FROM NORTHWEST TO SOUTHEAST. COOL...NEAR TO JUST BELOW
NORMAL TEMPERATURES WILL CONTINUE INTO THE WEEKEND AS SURFACE HIGH
PRESSURE BUILDS IN FROM THE WEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1132 PM MDT MON SEP 23 2013
A FEW LOWER CLOUDS WITH OCCASIONAL MVFR CEILINGS CIRCULATING
AROUND THE LOW PRESSURE CENTER OVER SOUTH CENTRAL NEBRASKA MAY
MOVE THROUGH THE MCK TAF AREA BETWEEN 06Z-07Z...BUT SHOULD MOVE
OUT OF THE AREA QUICKLY FOR CLEAR SKIES AND VFR CONDITIONS THROUGH
THE REMAINDER OF THE TAF PERIOD AS THE LOW CENTER CONTINUES TO
MOVE EAST AND IS REPLACED BY HIGH PRESSURE.
GLD WILL START OUT AND REMAIN VFR THROUGH THE PERIOD. GLD WILL
FLIRT WITH LLWS WITH NORTH NORTHWEST WINDS OF 30-50KTS WITHIN
ABOUT 1K FT OFF THE SURFACE...BUT EXPECT WINDS AT THE SURFACE AND
ALOFT TO DECREASE THROUGH THE NIGHT AT BOTH MCK AND GLD WITH THE
DECREASING PRESSURE GRADIENT AS THE LOW MOVES OUT OF THE REGION.
WINDS AFTER 18Z WILL BECOME LIGHT AND VARIABLE AND TURN TO THE
SOUTHEAST AFTER 03Z AS A LEE TROUGH BEGINS TO DEEPEN ALONG THE
FRONT RANGE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...LOCKHART
SHORT TERM...FS
LONG TERM...RRH
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
337 AM EDT TUE SEP 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 336 AM EDT TUE SEP 24 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW AN UPR RDG OVER
THE GREAT LKS BTWN A CLOSED LO OVER THE CNDN MARITIMES AND A LARGER
SCALE TROF OFF THE W COAST. SFC HI PRES UNDER THE SLOWLY BLDG UPR
RDG IN THE GREAT LKS EXTENDS FM QUEBEC SWWD TO NEAR THE SAULT. WITH
THE LARGER SCALE SUBSIDENCE AND BONE DRY MID LVLS ABV THE SUBSIDENCE
INVRN SHOWN AT H9 ON THE 00Z GRB RAOB...SKIES ARE CURRENTLY MOCLR.
ALTHOUGH A LLVL SE FLOW IS PRESENT OVER NRN LK MI ON THE WRN FLANK
OF THE SFC RDG AXIS LIKE YESTERDAY MRNG...THERE IS SO FAR NO LO CLD
SHOWING UP OVER NRN LK MI DUE TO PRESENCE OF WARMER/DRIER AIR BLO A
LOWER INVRN BASE THAN WAS PRESENT 24 HRS AGO. SFC TEMPS HAVE STILL
DIPPED AS LO AS THE 30S AT SOME OF THE COLD SPOTS OVER THE INTERIOR
SCENTRAL AND E UNDER A FLATTER PRES GRADIENT CLOSER TO THE RDG AXIS.
A SHARPER PRES GRADIENT/STRONGER SW FLOW IS RESTRICTING THE DIURNAL
TEMP DROP OVER THE W AND NCENTRAL NEAR LK SUP. LOOKING FARTHER TO
THE W...A FAIRLY VIGOROUS NEGATIVELY TILTED SHRTWV IS PRESENT OVER
THE CENTRAL PLAINS AND LIFTING ENEWD E OF THE WRN TROF. PCPN AND
EVEN MUCH IN THE WAY OF CLDS IN ADVANCE OF THIS FEATURE AND
ACCOMPANYING SFC LO IN NEBRASKA ARE LIMITED BY VERY DRY AIR SHOWN ON
NEARBY 00Z RAOBS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE POTENTIAL LO CLDS NEAR LK
MI AND TEMPS. WITH CLOSED LO SPINNING OVER THE CNDN MARITIMES...THE
PATTERN WL REMAIN NEARLY STAGNANT THRU TNGT. WITH THE UPR RDG
REMAINING NEARLY STNRY OVER THE GREAT LKS...SHRTWV MOVING E THRU THE
PLAINS IS PROGGED TO WEAKEN AND PASS WELL TO THE S OF UPR MI AND
HAVE NO IMPACT ON THE CWA.
TODAY...ALTHOUGH NO CLDS HAVE FORMED AS OF 06Z...SOME OF THE SHORTER
TERM MODELS HINT SOME LK EFFECT LO CLDS WL FORM OVER NRN LK MI AND
THE SE CWA THRU SUNRISE AIDED BY NOCTURNAL COOLING OF SHALLOW SUB
INVRN LYR. ON THE OTHER HAND...SOME OF THE HIER RESOLUTION GUIDANCE
THAT HAS HAD A GOOD TRACK RECORD WITH THIS LO CLD IN RECENT DAYS...
SPECIFICALLY THE 00Z LOCAL WRF-ARW MODEL AND SOME RAPID UPDATE
MODELS...SHOW LIMITED LK EFFECT LO CLDS. GIVEN THE WARMER TEMPS
OBSVD AT THE INVRN BASE...SUSPECT FOG RELATED TO RADIATION COOLING
OVER LAND WL BE MORE LIKELY AT LEAST OVER THE INTERIOR SCENTRAL AND
E. SO ADDED SOME FOG/LO CLD IN THIS AREA INTO MID MRNG. WITH LOWER
SUN ANGLE...SOME LO CLD MIGHT LINGER INTO EARLY AFTN BEFORE BURNING
OFF. OVER THE W...ABUNDANT SUNSHINE IN THE PRESENCE OF H85 TEMPS
NEAR 12Z WL BOOST MAX TEMPS INTO THE 70S AWAY FM THE INFLUENCE OF LK
SUP IN LLVL E-SE FLOW. AREAS OVER THE E AND SCENTRAL WL BE COOLER...
ESPECIALLY IF ANY LO CLDS THAT FORM ARE MORE EXTENSIVE AND LINGER
LONGER.
TNGT...WITH A WEAKER PRES GRADIENT TNGT AS THE SFC HI PRES RDG
EXPANDS A BIT TO THE W AND MID LVL DRY AIR/PWAT NEAR 0.50 INCH
LINGERING...TENDED TOWARD THE LO END OF GUIDANCE FOR MIN TEMPS UNDER
MOCLR SKIES. EXPECT SOME FOG TO DVLP UNDER THESE CONDITIONS WITH
LENGTHENING DARKNESS. THERE MAY ALSO BE SOME FROST AT SOME OF THE
INTERIOR COLDER LOCATIONS... BUT THE EXPECTED COVERAGE SHOULD NOT BE
ENUF TO JUSTIFY A FROST ADVY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 336 AM EDT TUE SEP 24 2013
THE SECOND HALF OF THE WORK WEEK WILL SEE THE AREA REMAINING UNDER
THE INFLUENCE OF THE UPPER RIDGE OVER THE GREAT LAKES AND ONTARIO
AND A SURFACE HIGH STATIONED OVER EASTERN ONTARIO AND WESTERN
QUEBEC. THIS SETUP WILL CONTINUE WARM AND DRY CONDITIONS OVER THE
U.P. THROUGH FRIDAY. WILL CONTINUE THE MOSTLY SUNNY IDEA FOR THE
FORECAST WITH HIGHS IN THE UPPER 60S AND LOWER 70S EACH DAY.
FOR THE WEEKEND...THE UPPER TROUGH CURRENTLY APPROACHING THE
PACIFIC NORTHWEST WILL BEGIN TO MOVE OUT OF THE ROCKIES ON FRIDAY
AND THROUGH THE UPPER GREAT LAKES REGION THIS WEEKEND. LATEST
GFS/CANADIAN RUNS HAVE TRENDED TOWARDS THE SLOWER ECMWF RUN AND
WILL CONTINUE TO TREND THE POP FORECASTS TOWARDS THAT SLOWER
SOLUTION. THAT SEEMS REASONABLE WITH THE STRONG RIDGE OVER OUR
AREA AND THE SLOW TO EXIT LOW DEPARTING THE CANADIAN MARITIMES. NOW
INSTEAD OF THE FRONT AND UPPER TROUGH MOVING THROUGH FRIDAY NIGHT
AND SATURDAY (AS SHOWN THE LAST COUPLE OF NIGHTS)...THEY LOOK TO
MOVE ACROSS THE AREA SATURDAY NIGHT INTO SUNDAY. THERE COULD
STILL BE SOME SHOWERS OVER WESTERN LAKE SUPERIOR AND POTENTIALLY
WESTERN UPPER MICHIGAN FRIDAY NIGHT INTO SATURDAY...ASSOCIATED WITH
AN AREA OF FGEN ALONG THE ELONGATED SURFACE TROUGH THAT IS SETUP
OVER THE MN ARROWHEAD. THUS...WILL KEEP AT LEAST SOME SLIGHT CHANCE
POPS OVER THE WESTERN THIRD OF THE CWA FOR FRIDAY NIGHT INTO
SATURDAY BEFORE TRANSITIONING IT ACROSS THE REST OF THE CWA. WITH
THE LATEST TRENDS...THERE COULD BE A DECENT SOAKING RAIN FOR THE
WESTERN CWA DUE TO SLOW EASTWARD MOVEMENT AND SOUTHWESTERLY FLOW
AHEAD OF THE TROUGH. THAT AREA HAS BEEN DRY THIS MONTH...SO IT
WILL BE MUCH NEEDED. FINALLY...OPTED TO REMOVE THUNDER FROM ALL BUT
FAR WESTERN LAKE SUPERIOR (FRIDAY AFTERNOON/EVENING) AS
SHOWALTERS CONTINUE TO LOOK MARGINAL WITH VERY LIMITED MUCAPE VALUES
(LESS THAN 150 J/KG).
MODELS DIFFERENCES GROW HEADING INTO NEXT WEEK...AS THE
ECMWF/CANADIAN CONTINUE TO REINFORCE THE UPPER TROUGH IN THE
UPPER GREAT LAKES. MEANWHILE...THE 18Z GFS WAS VERY PROGRESSIVE AND
THE 00Z GFS IS HALFWAY BETWEEN THE PREVIOUS RUN AND THE
ECMWF/CANADIAN/GFS-ENS. LATE ARRIVING 00Z ECMWF HAS MOVED IN A
SLIGHTLY DIFFERENT DIRECTION...WITH WEAK RIDGING BEFORE ANOTHER
WAVE ON TUESDAY. THUS...WILL JUST GO WITH A SILENT 20 POP.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 130 AM EDT TUE SEP 24 2013
VFR CONDITIONS SHOULD PREVAIL AT KIWD/KCMX/KSAW THRU THIS FCST
PERIOD UNDER A GENERALLY DRY AIR MASS ASSOCIATED WITH HIGH PRES OVER
ONTARIO/WRN QUEBEC. AT THIS POINT...NOT ANTICIPATING LOW CLOUDS TO
FORM AT KSAW LATE TONIGHT UNDER SSE UPSLOPE FLOW OFF LAKE MICHIGAN
SINCE CURRENT DWPTS OVER NRN LAKE MICHIGAN AREN`T SIGNIFICANTLY
HIGHER THAN FORECAST MIN TEMPS OVERNIGHT. COULD SEE AN EASTERLY
LAKE BREEZE DEVELOP MID TUE AFTERNOON AT KCMX WITH SFC RDG NOSING IN
FROM THE EAST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 336 AM EDT TUE SEP 24 2013
WITH RELATIVELY WEAK PRES GRADIENT OVER THE UPPER GREAT LAKES...
EXPECT WINDS INTO FRI TO REMAIN UNDER 20 KTS. THE APPROACH OF A COLD
FRONT TOWARD SAT AND SHARPENING PRES GRADIENT MAY LEAD TO A BIT
STRONGER S WINDS UP TO 20-25 KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 AM EDT TUE SEP 24 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 405 PM EDT MON SEP 23 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A MID LEVEL RIDGE OVER THE
WRN GREAT LAKES. UPSTREAM...A WELL-DEFINED MID LEVEL LOW WAS LIFTING
NE THRU WRN NEBRASKA. ALTHOUGH THE SFC HIGH PRES RIDGE IS EAST OF
THE AREA...EXTENDING FROM JAMES BAY TO LAKE HURON...STUBBORN
STRATOCU REMAINS DOWNWIND OF LAKE MICHIGAN...THOUGH THERE ARE SIGNS
THAT COVERAGE IS STARTING TO SHRINK DUE TO A COMBINATION OF FALLING
INVERSION HEIGHTS (PER RAOBS TRENDS) AND DAYTIME HEATING MIXING OUT
LOW-LEVEL MOISTURE. WARMING AIR MASS IS ALSO DIMINISHING THE LAKE
COMPONENT TO CLOUD COVER. ABUNDANT SUNSHINE HAS HELPED TO RAISE
TEMPS INTO MID 60S THIS AFTN OVER THE W HALF OF UPPER MI.
ALTHOUGH A WELL-DEFINED SHORTWAVE IS OVER THE WRN PLAINS...SHORT
TERM AND THE NEXT SEVERAL DAYS WILL BE QUIET WEATHER WISE. MAIN FCST
CONCERN WILL BE CLOUD COVER. WITH STRATOCU COVERAGE NEAR LAKE
MICHIGAN SHOWING SIGNS OF SHRINKING...THERE IS HOPE THAT THE CLOUDS
WILL CONTINUE TO DISSIPATE AND NOT REDEVELOP/EXPAND TONIGHT...
ESPECIALLY SINCE INVERSION BASE TEMPS OVER NRN LAKE MICHIGAN WILL BE
A COUPLE OF C HIGHER TONIGHT THAN LAST NIGHT. HOWEVER...SINCE
TRAJECTORIES LEAD SSE BACK TO THE STRATOCU/MOISTURE FIELD OVER SRN
LWR MI/NRN OH...STRATOCU PROBABLY WON`T CLEAR OUT FOR THE ENTIRE
NIGHT. THERE MAY BE A PERIOD THIS EVENING WHEN MUCH OF THE CLOUD
COVER DISSIPATES...BUT EXPECT SOME INCREASE IN STRATOCU AGAIN
OVERNIGHT GIVEN UPSTREAM CLOUD COVER/MOISTURE AS MENTIONED AND DUE
TO LAND BREEZE CONVERGENCE DEVELOPING OVER LAKE MICHIGAN. CLOUDS
SHOULDN`T BE AS EXTENSIVE LATE TONIGHT/TUE MORNING AS EARLIER TODAY.
AS FOR TEMPS...GENERALLY FAVORED THE LOW END OF GUIDANCE WITH
PRECIPITABLE WATER 50-60PCT OF NORMAL AND WEAKER PRES
GRADIENT/LOW-LEVEL WINDS LATER TONIGHT THAN EARLY THIS MORNING. WITH
MINS DOWN INTO THE MID 30S IN THE INTERIOR...EXPECT PATCHY FROST
OVERNIGHT.
MODELS ARE IN GOOD AGREEMENT TAKING THE CURRENTLY WELL-DEFINED MID
LOW OVER NEBRASKA E INTO THE MID MISSISSIPPI VALLEY TUE AND
WEAKENING IT AS IT CUTS INTO THE MID LEVEL RIDGE. FEATURE WILL HAVE
NO AFFECT ON THE WEATHER HERE TUE AS DRY AIR LINGERS OVER THE AREA.
AS WITH TONIGHT...MAIN CONCERN TUE WILL BE STRATOCU NEAR LAKE MI.
STRATOCU DOWNWIND OF THE LAKE MAY BRIEFLY EXPAND WESTWARD FOR A
COUPLE OF HRS TUE MORNING AS DAYTIME HEATING WORKS ON LOW-LEVEL
MOISTURE...BUT THERE SHOULD BE A SOMEWHAT QUICKER EROSION OF THE
CLOUDS FROM INLAND TOWARD THE LAKE THAN TODAY. OTHER THAN THE CLOUD
ISSUE...TUE IS SHAPING UP TO BE A NICE AUTUMN DAY. IF MIXING REACHES
850MB...MAX TEMPS IN THE LOW/MID 70S WOULD BE COMMON. MIXING DEPTH
MAY NOT GET QUITE THAT HIGH...SO UPPER 60S/LWR 70S LOOK MORE LIKELY
AWAY FROM MARINE INFLUENCE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 249 PM EDT MON SEP 23 2013
WILL START THE PERIOD AT 00Z WEDNESDAY WITH THE 500MB RIDGE STILL
SET UP ACROSS E UPPER MI AND LAKE HURON/E ONTARIO. THE MAIN STORY
WILL BE THE CONTINUALLY WEAKENING TROUGH STRETCHING FROM MN THROUGH
NW TN. A HIGHLY BROKEN LINE OF SHOWERS MAY BE SET UP ACROSS MN...BUT
WITH THE WEAKENING OF THE TROUGH AND SFC HIGH WITH LIGHT NE FLOW AT
THE SFC...LITTLE MORE THAN CLOUDS ARE ANTICIPATED ACROSS UPPER MI
LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. BEHIND THE 500MB
TROUGH...THE S-CENTRAL PLAINS RIDGE WILL QUICKLY BUILD BACK ACROSS
THE UPPER GREAT LAKES WEDNESDAY THROUGH THURSDAY.
LOOK FOR STRONGER SW FLOW TO TAKE OVER ALOFT AT AT THE SFC THURSDAY
NIGHT THROUGH FRIDAY NIGHT...AHEAD OF THE NEARING TROUGH TO OUT W.
COOLER AIRMASS IS ON THE WAY FOR THE WEEKEND. WE CAN GET A GLIMPSE
OF WHAT IS TO COME BY LOOKING AT THE 00Z SATURDAY 850MB TEMPS ACROSS
THE REGION. 850MB TEMPS WILL LIKELY RANGE FROM 14-16Z ACROSS UPPER
MI...WHILE A MUCH COOLER 4-6C ACROSS NW ND. ONLY MINIMAL TS
POTENTIAL ALONG THE FRONT...GIVEN ITS NOCTURNAL PASSAGE OVER THE W
CWA SATURDAY MORNING. THERE ARE ENOUGH SIGNIFICANT DIFFERENCES
BETWEEN THE ECMWF AND GFS AT THIS POINT TO GO WITH A CONSENSUS
SOLUTION. THE 23/12Z RUN OF THE GFS IS AROUND 6HRS FASTER THAN THE
23/00Z ECMWF WITH THE PASSAGE OF THE SHORTWAVE. STILL...THEY ARE
STARTING TO COME TO A BETTER AGREEMENT WHEN COMPARED TO THE MUCH
QUICKER 23/06Z RUN OF THE GFS.
THE ENTIRE SYSTEM LOOKS TO MODERATE QUITE A BIT...WITH THE COOLEST
AIR FILTERING INTO UPPER MI BEING AROUND 5-7C SATURDAY NIGHT THROUGH
MONDAY MORNING. AS AN ASIDE...THE 23/12Z RUN OF THE GFS ONLY HAS
850MB TEMPS COOLING TO AROUND 10C. MUCH OF THIS IS DUE TO THE
DIFFERENCE IN THE HANDLING OF THE MID-UPPER LEVEL WAVE. THE ECMWF IS
PERSISTENT IN HAVING THE TROUGH OVER THE UPPER GREAT LAKES THIS
WEEKEND CUT OFF FROM THE MAIN W-E FLOW AND FORM A LOW
OVERHEAD...BEFORE DROPPING IT INTO THE MID MS VALLEY THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 130 AM EDT TUE SEP 24 2013
VFR CONDITIONS SHOULD PREVAIL AT KIWD/KCMX/KSAW THRU THIS FCST
PERIOD UNDER A GENERALLY DRY AIR MASS ASSOCIATED WITH HIGH PRES OVER
ONTARIO/WRN QUEBEC. AT THIS POINT...NOT ANTICIPATING LOW CLOUDS TO
FORM AT KSAW LATE TONIGHT UNDER SSE UPSLOPE FLOW OFF LAKE MICHIGAN
SINCE CURRENT DWPTS OVER NRN LAKE MICHIGAN AREN`T SIGNIFICANTLY
HIGHER THAN FORECAST MIN TEMPS OVERNIGHT. COULD SEE AN EASTERLY
LAKE BREEZE DEVELOP MID TUE AFTERNOON AT KCMX WITH SFC RDG NOSING IN
FROM THE EAST.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EDT MON SEP 23 2013
SLOW MOVING WEATHER PATTERN THIS WEEK WILL FEATURE HIGH PRES TO THE
E AND LOW PRES TO THE W. EVENTUALLY...A LOW PRES SYSTEM WILL MOVE NE
TO HUDSON BAY LATE WEEK WITH ASSOCIATED COLD FRONT PASSING ACROSS
LAKE SUPERIOR SAT. THRU THE WEEK...RELATIVELY WEAK PRES GRADIENT
WILL RESULT IN WINDS MOSTLY UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS HASTINGS NE
439 AM CDT TUE SEP 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM CDT TUE SEP 24 2013
ALTHOUGH MOST IF NOT ALL OF THE CWA IS LOOKING AT A DRY AND FAIRLY
UNEVENTFUL UPCOMING 24 HOURS...ESPECIALLY THE DAYTIME HOURS HAVE
BECOME TRICKIER-THAN-EXPECTED MAINLY REGARDING THE EVOLUTION OF
SKY COVER/TEMPERATURES...AS LOW CLOUDS COULD BE STUBBORNLY SLOW TO
DEPART MAINLY WITHIN THE EASTERN 1/2 OF THE CWA...BRINGING 5+ DEGREE
TEMP BUST POTENTIAL VERY MUCH INTO PLAY.
08Z OBJECTIVE SURFACE ANALYSIS HIGHLIGHTS A SLOWLY-WEAKENING 1004
MILLIBAR LOW PRESSURE CENTER...CENTERED OVER THE CLAY/FILLMORE
COUNTY AREA...WHILE IN ITS WAKE THE LEADING EDGES OF HIGH PRESSURE
AROUND 1016MB HAS WORKED INTO THE NEB PANHANDLE. WITH THE MAJORITY
OF THE CWA POSITIONED BEHIND THE DEPARTING LOW...EARLY MORNING
BREEZES ARE MAINLY FROM THE WEST-NORTHWEST...WITH THE STRONGEST
SPEEDS WITH GUSTS OF 20+ MPH FOCUSED ACROSS THE SOUTHWESTERN HALF
OF THE AREA...WITH LIGHTER SPEEDS STILL HOLDING ON FOR AT LEAST A
FEW MORE HOURS WITHIN MUCH OF THE NORTHEAST 1/2. ALOFT...WATER
VAPOR IMAGERY AND SHORT TERM MODEL DATA CLEARLY REVEAL A WELL-
DEFINED...NOT QUITE VERTICALLY STACKED LOW PRESSURE SYSTEM
DEPARTING EASTWARD ACROSS THE EASTERN 1/4 OF NEB...WITH A CLOSED
500MB CIRCULATION CENTERED NEAR NORFOLK. AS A RESULT...THE PRIMARY
MID LEVEL CONVERGENCE/DEFORMATION ZONE AT THIS HOUR IS FOCUSING
WIDESPREAD MAINLY LIGHT RAIN 50+ MILES NORTHEAST OF THE
CWA. CLOUD-WISE...11-3.9 MICRON SATELLITE IMAGERY DEPICTS A
FAIRLY COMPLEX AND EVER-CHANGING MIXTURE OF CLEAR SKIES ALONG WITH
PASSING BATCHES OF MID CLOUDS AND LOW STRATUS. WHILE MOST OF THESE
LOWER CEILINGS WITHIN THE CWA ARE AT/ABOVE 1500 FT...A CORRIDOR OF
LOWER CEILINGS BETWEEN 500-1000 FT SEEMS TO BE LURKING JUST
NORTHWEST OF THE CWA ALONG A BROKEN BOW-AINSWORTH AXIS...WITH
THESE LOW CLOUDS POSSIBLY EVEN SUPPORTING SOME PATCHY LIGHT
DRIZZLE. TEMP-WISE...MOST OF THE CWA APPEARS HEADED FOR OVERNIGHT
LOWS IN THE MID 50S...WITH ANY LOW 50S/UPPER 40S MOST FAVORED IN
FAR WESTERN COUNTIES.
AS THE EARLY MORNING/DAYTIME HOURS WEAR ON...THE BIG PICTURE ALOFT
INVOLVES THE MID LEVEL SHORTWAVE TROUGH/ASSOCIATED CLOSED LOW
CONTINUING ITS STEADY TREK EASTWARD...WITH THE 500MB CIRCULATION
CENTER INTO SOUTHWEST IA BY 18Z...AND THEN OVER NORTH CENTRAL MO
BY 00Z/7PM. AS THIS LOW DEPARTS...A BROAD AREA OF SHORTWAVE
RIDGING AND ASSOCIATED HEIGHT RISES WILL OVERSPREAD THE CENTRAL
PLAINS. AT THE SURFACE...THE LOW PRESSURE CENTER CURRENTLY OVER
SOUTHEAST NEB WILL CONTINUE TO WEAKEN AS IT SLIDES INTO CENTRAL MO
OVER THE COURSE OF THE DAY...ALLOWING A MODEST RIDGE AXIS TO BUILD
INTO THE LOCAL AREA WITH TIME AND RELAX THE SURFACE PRESSURE
GRADIENT. HOWEVER...BREEZES WILL STILL BE FAIRLY ELEVATED FOR
MUCH OF THE DAY TODAY...LARGELY OWING TO MIXING CLIMBING UP TO
AROUND 850MB...WHERE AN ENHANCED CORRIDOR OF 30-40KT NORTHERLY
WINDS WILL LINGER THROUGH MID-DAY BEFORE STEADILY WEAKENING IN THE
AFTERNOON. THE NET RESULT WILL BE SUSTAINED NORTH-NORTHWEST WIND
SPEEDS 15-20 MPH WITH GUSTS 25+ MPH THROUGH THIS MORNING...BEFORE
DIMINISHING TO MORE SO SUSTAINED 10-15 MPH SPEEDS THIS
AFTERNOON...AND ONLY 5-10 MPH CLOSER TO SUNSET. AS FOR PRECIP
CHANCES...ALTHOUGH RADAR TRENDS AND SHORT TERM MODEL DATA
INCLUDING THE HRRR PRETTY STRONGLY SUGGEST THAN ANY RISK OF
MEASURABLE LIGHT RAIN SHOULD BE OVER BY 12Z...WENT AHEAD AND
LINGERED A TOKEN 20 POP IN THE EXTREME NORTHEAST
NANCE/MERRICK/POLK AREA THROUGH 15Z IN CASE SOMETHING MANAGES TO
STILL WRAP AROUND THE BACK SIDE OF THE LOW. THE BIG CHALLENGE
TODAY SEEMS TO BE CENTERED AROUND SKY COVER. 24 HOURS AGO...IT WAS
ASSUMED THAT MID LEVEL CLOUDS WOULD QUICKLY MOVE OFF EAST OF THE
CWA TODAY WITH THE PARENT SYSTEM. HOWEVER...LATEST SATELLITE AND
SHORT TERM MODEL DATA INCLUDING THE HRRR LOW CLOUD PRODUCT NOW
SUGGEST THAT THE AREAL COVERAGE OF LOW STRATUS MAY IN FACT
INCREASE BEFORE SUNRISE FROM THE NORTHWEST...AND THEN POSSIBLY
HANG VERY STUBBORNLY MAINLY ACROSS THE CENTRAL/EASTERN CWA EVEN
INTO THE AFTERNOON HOURS. ALTHOUGH HAVE NOT BOUGHT FULL-BORE INTO
THE VERY PESSIMISTIC RUC/HRRR SOLUTIONS REGARDING LOW CLOUDS
TODAY...DID INCREASE SKY COVER PERCENTAGES VERSUS PREVIOUS...AND
ALSO DELAYED THE WEST-EAST CLEARING TREND. HOWEVER...PLEASE NOTE
THAT ESPECIALLY EASTERN COUNTIES ALONG/NEAR HIGHWAY 81 MAY REALLY
STRUGGLE TO SEE MUCH SUN UNTIL MAYBE LATE AFTERNOON...AND DAY
SHIFT MAY HAVE TO MAKE SOME PRETTY NOTICEABLE ADJUSTMENTS TO SKY
COVER AND RESULTANT HIGH TEMPS. FOR NOW THOUGH...OPTED TO ONLY
SHAVE 1-2 DEGREES OFF PREVIOUS HIGHS IN MOST AREAS...RANGING FROM
LOW 70S FAR EAST TO UPPER 70S FAR SOUTHWEST...AND AROUND 73 TRI-
CITIES. IF CLOUDS ARE SLOW TO DEPART HOWEVER...SOME EASTERN AREAS
MAY STRUGGLE TO LEAVE THE 60S. ON ONE FINAL DAYTIME
NOTE...ALTHOUGH HAVE DEWPOINTS DROPPING INTO THE LOW-MID 40S
ACROSS MUCH OF THE WESTERN CWA DURING THE AFTERNOON...THESE VALUES
ARE NOT QUITE AS LOW AS ANTICIPATED 24 HOURS AGO...AND THIS KEEPS
ANY AFTERNOON RELATIVE HUMIDITY VALUES AS LOW AS 25-30 PERCENT
CONFINED TO MAINLY JUST THE FURNAS COUNTY AREA.
FOR THE EVENING/NIGHT 00Z-12Z PERIOD...WILL RUN WITH THE
ASSUMPTION THAT EVEN IF LOW STRATUS LINGERS QUITE AWHILE INTO THE
AFTERNOON IN SOME AREAS...THAT IT SHOULD BE SAFELY EAST OF THE CWA
BY SUNSET...THUS RESULTING IN A CLEAR OVERNIGHT AREA-WIDE WITH
ESSENTIALLY ZERO RISK OF PRECIP. ON THE BIG PICTURE...THE HEART OF
THE AFOREMENTIONED MID/UPPER LEVEL SHORTWAVE RIDGE AXIS WILL PASS
DIRECTLY OVER THE CWA...VERY SIMILAR TO LAST FRIDAY NIGHT. ALSO
SIMILAR TO LAST FRIDAY AT THE SURFACE...VERY LIGHT/VARIABLE
BREEZES IN THE EVENING WILL GRADUALLY GIVE WAY TO LIGHT SOUTHEAST
BREEZES LATER IN THE NIGHT AS THE SURFACE RIDGE AXIS DRIFTS
EASTWARD ACROSS THE CWA. HOWEVER...COMPARED TO 24 HOURS AGO IT NOW
APPEARS THAT DEWPOINTS WILL NOT DROP OFF QUITE AS FAR...AND THUS
GUIDANCE/MODELS HAVE TRENDED A FEW DEGREES MILDER FOR OVERNIGHT
LOWS. AS A RESULT...NUDGED UP LOWS 1-2 DEGREES MOST AREAS VERSUS
PREVIOUS...AIMING MOST OF THE CWA BETWEEN 50-53...BUT WITH
PREDOMINANTLY MID-UPPER 40S IN A FEW OF THE FAR WESTERN
NORTHERN/COUNTIES. DESPITE THE LIGHT OVERNIGHT BREEZES...AM NOT
EXPECTING IMPACTFUL FOG TO BE AN ISSUE...ALTHOUGH SOME VERY LIGHT
FOG/HAZE IS PROBABLY NOT OUT OF THE QUESTION...BUT IS ALSO NOT
WORTH ADVERTISING IN THE FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM CDT TUE SEP 24 2013
PATTERN: THE CPC OBSERVED H5 HGT ANOMALY TOOLS SHOW THAT THE LOW
FREQUENCY /LGWV/ FLOW OF THE PAST 90 DAYS LARGELY REMAINS IN PLACE
OVER THE NRN HEMISPHERE. HOWEVER...WE HAVE RECENTLY SEEN
AMPLIFICATION ESPECIALLY WITH THE ERN PAC TROF. OTHER ADJUSTMENTS
SHOW THAT THE +HGT ANOMALY WHICH HAS RESIDED OVER WRN N AMERICA HAS
SHIFT TO THE E...ALLOWING THE TEMPORARY ESTABLISHMENT OF A WRN N
AMERICA TROF. THIS TROF WILL ONLY BE WITH US THIS WEEK AND OFFERS
ONE MORE SHOT AT DECENT RAINFALL. THE NAO HAS TURNED SHARPLY
NEGATIVE AS THE PERSISTENT -HGT ANOMALY OVER GREENLAND HAS BEEN
REPLACED WITH +HGT ANOMALIES. THIS COMBINED WITH THE A PAIR OF
STORMS CROSSING THE NRN PAC WILL RETURN RIDGING TO WRN N AMERICA
THIS WEEKEND. SO THE BOTTOM LINE IS...EXCEPT FOR A BRIEF WINDOW THU
NGT-FRI...DRY WX WILL CONT. TEMPS WILL BE VARIABLE BUT PROBABLY
AVERAGE PRETTY CLOSE TO NORMAL OVER THE NEXT 10 DAYS.
ALOFT: SW FLOW WILL DEVELOP OVER THE CNTRL PLAINS WED AND CONT THRU
FRI...AS THE WRN USA TROF FULLY RELOADS. CYCLOGENESIS WILL OCCUR
THU...WITH THE MAIN UPR LOW HEADING N INTO CANADA. THE MAIN UPR TROF
WILL BE LEFT BEHIND AND BEGIN LIFTING NE...CROSSING THE CNTRL PLAINS
SAT. NW FLOW FOLLOWS SUN-MON BUT THERE IS DISAGREEMENT/UNCERTAINTY
IN THE AMPLITUDE OF THE RIDGE MOVING INTO THE W.
SFC: A PAC COLD FRONT WILL EXTEND FROM THE NRN ROCKIES TO CNTRL CA
WED...WITH A LEE-SIDE TROF IN PLACE. THIS FRONT WILL ADVANCE E AND
EMERGE ONTO THE PLAINS BY DAWN THU. HOWEVER...THE SRN PORTION WILL
REMAIN STATIONARY DUE TO MINIMAL MOVEMENT OF THE BASE OF THE TROF.
THE SLOW EJECTION OF THE TROF MEANS THE FWD PROGRESS OF THE FRONT
WILL BE SLOW. WRN USA HIGH PRES BUILDS IN SAT THRU MON.
WITH SW FLOW ALOFT ON BOTH SIDES OF THIS FRONT...IT WILL HAVE AN
ANABATIC CHARACTER. THE SLOW MOVEMENT OFFERS THE OPPORTUNITY FOR
ENTRAINMENT OF GULF MSTR. WE ARE SEEING A NARROW RIBBON OF MSTR FCST
TO SURGE NWD FRI...WITH PW NEARING 1.6".
HAZARDS: NOTHING SUBSTANTIAL...BUT THERE IS A LATE-WEEK THUNDER
THREAT. RISK OF SVR LOOKS VERY LOW.
THE DAILY DETAILS...
WED: WARM SECTOR. BREEZY AND WARMER BY 7-10F.
WED NGT: A STRONG LLJ WILL DEVELOP /55-60 KTS/ WITH LOW-LVL WINDS
VEERING TO THE SW. THIS WILL ADVECT AN EML ONTO THE PLAINS...
IMPOSING A SUBSTANTIAL CAP.
THU: WARM SECTOR. VERY WARM. ADD ANOTHER 3-7F TO WED AND THIS WILL
PUT HIGHS 10F ABOVE NORMAL. HIGHS IN THE LWR 90S LOOK LIKE A GOOD
BET OVER N-CNTRL KS.
THU NGT: SOME ISOLATED HIGH-BASED SHWRS/TSTMS ARE POSSIBLE. THIS
REALLY DEPENDS ON WHERE THE LLJ CORE SETS UP. THE EC IS FURTHER N
THAN THE GFS AND NAM. IF SHWRS/TSTMS DEVELOP RAINFALL AMTS WILL BE
VERY LIGHT.
FRI: WARM SECTOR...BUT THE FRONT THREATENS THE NW FRINGE OF THE FCST
AREA DURING PEAK HEATING. MOST OF THE FCST AREA SHOULD REMAIN DRY
FOR MOST OF THE DAY. PCPN AND CLOUDS WILL BE MOST EXTENSIVE BEHIND
THE FRONT WHICH SHOULD RESULT IN A SUBSTANTIAL TEMP CONTRAST ACROSS
THE STATE. AHEAD OF THE FRONT EXPECT THE ATMS TO BE CAPPED. SCT
TSTMS SHOULD ONLY ERUPT IN THE IMMEDIATE VICINITY OF THE FRONT IN
THE LATE AFTN.
SEVERE?: PROBABLY NOT BUT IF THERE IS A THREAT IS LOOKS VERY
MARGINAL DUE TO WEAK INSTABILITY. HOWEVER...STRENGTH OF THE WIND
FIELDS AND THE DRY SUB-CLOUD LAYER COULD SUPPORT SOME DECENT WINDS
IF A STRONGER STORM OR TWO CAN DEVELOP.
FRI NGT: COLD FRONTAL PASSAGE. THE SETUP LOOKS GOOD FOR SOME DECENT
POST-FRONTAL RAINFALL IN SOME LOCATIONS.
SAT: MUCH COOLER! PROBABLY 20F COOLER THAN FRI. IN FACT...WITH
THE UPR TROF MOVING THRU...BELIEVE FUTURE FCSTS WILL END UP LOWERING
HIGHS ANOTHER 5F OR SO. CONSENSUS OF 2M TEMPS CURRENTLY OFFERS 57F
AT ORD AND 67F AT BELOIT. NOT MUCH DIFF FROM THE 12Z/18Z CYCLES.
SWEATSHIRTS AND JACKETS MAY BE NEEDED FOR OUTDOOR ACTIVITIES.
CLOUDY TO START WITH A COUPLE LEFTOVER SHWRS OR SOME PATCHY DRZL.
CLEARING PROGRESSES FROM W TO E IN THE AFTN.
SUN-MON: BACK TO NICER WX. TEMPS REBOUND AND WITH LOW PRES MOVING
THRU THE CANADIAN ROCKIES...A LEE-SIDE TROF WILL DEVELOP AND MAY
ACTUALLY PROGRESS THRU THE FCST AREA WITH AN ATTENDANT THERMAL
RIDGE. HIGHS SHOULD BE BACK INTO THE LOW-MID 70S SUN AND UPR 70S-80
MON?
&&
.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1230 AM CDT TUE SEP 24 2013
ALTHOUGH CONFIDENCE REMAINS HIGH IN VFR VISIBILITY THROUGH THE
NEXT 24 HOURS...CEILING TRENDS COULD BE A CHALLENGE ESPECIALLY
DURING THE NEXT 12 HOURS...AS THE LOCAL AREA IS CURRENTLY A MIXED
BAG OF CLEAR SKIES INTERSPERSED WITH PASSING BATCHES OF LOW
VFR...MVFR AND POSSIBLY EVEN IFR LOW CLOUDS. STRONGLY CONSIDERED
ADDING A PREVAILING MVFR CEILING FOR SEVERAL HOURS CENTERED
BETWEEN 12Z-18Z...BUT GIVEN LOW CONFIDENCE IN VARIOUS MODEL
SOLUTIONS AND OBSERVATIONAL TRENDS WILL ONLY RUN WITH A TEMPO MVFR
MENTION FROM 10Z-14Z FOR NOW...AND FURTHER EVALUATE PREVAILING
MVFR POTENTIAL WITH THE NEXT ROUTINE TAF ISSUANCE. IN GENERAL
HOWEVER...ANTICIPATE AT LEAST LOW-VFR CEILINGS TO REMAIN FAIRLY
PREVALENT THROUGH MID-DAY BEFORE LIFTING AND GRADUALLY SCATTERING
OUT DURING THE AFTERNOON HOURS...WITH HIGH CONFIDENCE IN NO WORSE
THAN CLEAR/MOSTLY CLEAR SKIES DURING AT LEAST THE FINAL 9 HOURS OF
THE PERIOD. AS FOR SURFACE WINDS...A PRONOUNCED SHIFT TO NORTHWEST
BREEZES WILL ARRIVE AT KGRI WITHIN THE NEXT FEW HOURS BEHIND A
PASSING COLD FRONT...WITH GUST POTENTIAL TO AT LEAST 22KT OR
HIGHER LASTING THROUGH MID-DAY BEFORE STEADILY DIMINISHING DURING
THE AFTERNOON AND BECOMING LIGHT/VARIABLE FOR TUESDAY EVENING.
&&
.HYDROLOGY...
ISSUED AT 438 AM CDT TUE SEP 24 2013
OVERALL LITTLE CHANGE IN EXPECTATIONS OVERNIGHT REGARDING PLATTE
RIVER FLOODING/FLOODING POTENTIAL. WE CONTINUE TO ADVERTISE TWO
OFFICIAL FLOOD WARNINGS AT THIS TIME...ONE FOR THE RIVER GAGE NEAR
COZAD...WHICH COVERS THE PLATTE RIVER REACH ACROSS DAWSON COUNTY
INTO FAR WESTERN BUFFALO...AND A SECOND FOR THE GAGE NEAR
KEARNEY...WHICH COVERS THE REACH OF THE RIVER ALONG THE
BUFFALO/PHELPS/KEARNEY COUNTY LINE...AND THEN ACROSS THE MAJORITY
OF HALL COUNTY. ALTHOUGH THE LATEST MISSOURI BASIN RIVER FORECAST
CENTER (MBRFC) FORECAST TAKES THE GRAND ISLAND GAGE A FEW MILES
EAST OF TOWN BARELY INTO MINOR FLOOD STAGE WEDNESDAY NIGHT...WE
CONTINUE TO HOLD OFF ON A FORMAL FLOOD WARNING FOR THIS EASTERN
HALL COUNTY AREA AND POINTS EAST...MAINLY TO GIVE A BIT MORE TIME
TO FINE TUNE THE FORECAST BASED ON UPSTREAM BEHAVIOR AT THE COZAD
AND KEARNEY GAGES...AND ALSO THE OVERTON GAUGE WHICH IS NOT AN
OFFICIAL FORECAST POINT.
OVER THE PAST SEVERAL HOURS...THE GAGE ALONG THE NORTH CHANNEL AT
COZAD FINALLY REACHED MINOR FLOOD STAGE OF 6.5 FT AT 9 PM MONDAY
EVENING...AND HAS CONTINUED A STEADY CLIMB TO JUST OVER 7.2 FT AS OF
330 AM. AS A RESULT...THE CREST WHICH IS EXPECTED TO OCCUR
SOMETIME TODAY HAS BEEN NUDGED UPWARD TO 7.3 FT. THIS IS
ANTICIPATED TO BE A PROLONGED CREST WITH ONLY A VERY SLOW FALL TO
BELOW FLOOD STAGE BY SOMETIME FRIDAY. MEANWHILE...THE LATEST
OVERNIGHT TRENDS ON THE OVERTON AND KEARNEY GAGES CONTINUE TO
REFLECT VERY SLOW RISES...AND IT IS YET TO BE SEEN WHETHER THE
KEARNEY GAGE IN FACT CAN BREACH THE MINOR FLOOD STAGE OF 6.0 FT BY
LATE THIS MORNING AS THE LATEST FORECAST SUGGESTS. AT ANY RATE...A
CREST OF 7.2 FT CONTINUES TO BE FORECAST FOR KEARNEY ON
WEDNESDAY...AND AGAIN THIS WILL BE A PROLONGED CREST WITH A VERY
SLOW FALL...POSSIBLY REMAINING IN FLOOD STAGE THROUGH THE END OF
THE MONTH.
PLEASE NOTE ONLY MINOR FLOOD STAGE...AND NOT MODERATE/MAJOR
CATEGORIES...ARE ANTICIPATED ALONG THE AFOREMENTIONED FORECAST
POINTS WITHIN THE NWS HASTINGS CWA...AND THUS THE VAST MAJORITY OF
IMPACTS SHOULD REMAIN CONFINED TO THE IMMEDIATE LOWLAND AREAS
NEAR THE RIVER CHANNEL/S. THESE RIVER FORECASTS ARE UPDATED
REGULARLY PER COORDINATION BETWEEN MBRFC AND NWS HASTINGS...AND
MINOR TWEAKS IN CREST HEIGHT AND TIMING REMAIN LIKELY OVER THE
COMING DAYS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...HALBLAUB
AVIATION...PFANNKUCH
HYDROLOGY...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1236 AM CDT TUE SEP 24 2013
.UPDATE...
ISSUED AT 1230 AM CDT TUE SEP 24 2013
PRIMARY CHANGE WITH THE LATEST SHORT-TERM UPDATE THROUGH THE REST
OF THE OVERNIGHT HOURS WAS TO RELEGATE ANY MENTION OF
ISOLATED/SCATTERED SHOWERS TO LOCATIONS GENERALLY NORTH OF A LOUP
CITY-CENTRAL CITY-YORK LINE...AND EVEN AT THAT THE MAJORITY OF
THAT AREA MAY BE LUCKY TO SEE MORE THAN A NON-MEASURABLE SPRINKLE
THROUGH THE REST OF THE NIGHT PER LATEST RADAR TRENDS.
OTHERWISE...SKY COVER WILL BE RATHER COMPLEX THROUGH THE NEXT 12
HOURS OR SO...WITH AREAS OF CLEAR SKIES INTERSPERSED WITH
MIGRATING BATCHES OF LOW AND MID LEVEL CLOUDS. IT IS STARTING TO
APPEAR HOWEVER THAT THE POST-SUNRISE TUESDAY MORNING HOURS COULD
START OUT CLOUDIER THAN EARLIER EXPECTED ACROSS PARTS OF THE
CENTRAL/EASTERN CWA PER LOW LEVEL RELATIVE HUMIDITY PROGS FROM THE
NAM AND ALSO THE HRRR LOW LEVEL CLOUD COVER PRODUCT...AND THESE
TRENDS WILL CONTINUE TO BE MONITORED AND DISCUSSED IN MORE DETAIL
IN THE PRIMARY MORNING DISCUSSION.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 410 PM CDT MON SEP 23 2013
PRIMARY FORECAST CONCERN LIES WITH PRECIPITATION CHANCES.
NOT HARD TO PICK OUT THE FEATURES OF INTEREST THIS
AFTERNOON...WITH WV SATELLITE IMAGERY SHOWING A WOUND UP UPPER
LEVEL LOW PRESSURE SYSTEM GRADUALLY MAKING ITS WAY THROUGH WRN
PORTIONS OF NEB AND FAR NWRN KS. ITS A WELL STACKED SYSTEM...AND
THE SFC LOW IS IN THE SAME AREA...WITH SFC OBS SHOWING THE MAIN
FRONTAL BOUNDARY EXTENDING NORTH THROUGH CHERRY CNTY NEB. THE
NARROW BAND OF SHOWERS/ISO THUNDER DRIVEN BY UPPER LEVEL JET
ENERGY IS FINALLY STARTING TO WORK ITS WAY THROUGH/OUT OF ERN
PORTIONS OF THE CWA...BUT THE NEXT ROUND OF PRECIPITATION IS
GEARING UP...ASSOCIATED WITH INCREASED LIFT WITH THE LOW ITSELF.
AT THE SURFACE...WITH THE TIGHTENED PRESSURE GRADIENT SET UP AHEAD
OF THE APPROACHING LOW...AND WITH INCREASED MIXING POTENTIAL...IT
HAS BEEN A BREEZY AFTERNOON. THIS HAS ESP BEEN THE CASE ACROSS
WRN/CENTRAL PORTIONS OF OUR NC KS COUNTIES /MAINLY SMITH
CENTER/...WHICH SAT UNDER LESS CLOUD COVER THAN THE REST OF THE
CWA...WAS ABLE TO TAP INTO THAT BETTER POTENTIAL FOR STRONGER
WINDS...AND AT TIMES BOUNCE AROUND/HIT ADV CRITERIA. WITH THE
FRONT APPROACHING AND THE NEXT BATCH OF CLOUDS STARTING TO MOVE
INTO THAT AREA...WHICH SHOULD KEEP WINDS DOWN A BIT.
THE MAIN FOCUS FOR THE SHORT TERM IS REALLY OVER THE NEXT 6-12
HRS...AS THIS UPPER LEVEL LOW CONTINUES TO DRIFT E/NE THROUGH THE
AREA. SPC MESO PAGE SHOWING AN AREA OF INCREASED LOWER LEVEL LAPSE
RATES OVER WRN PORTIONS OF THE CWA AND INTO WRN NEB/KS...THOUGH
OVERALL INSTABILITY IS PRETTY WEAK. JUST TO THE WEST OF THE
CWA...VIS SAT SHOWS A NARROW AREA WHERE THERE HAS BEEN A BIT MORE
SUN...AND INSTABILITY/LAPSE RATES VALUES A TOUCH HIGHER THERE.
THIS IS LOCATED IN THE SAME AREA AS THE MAIN LOW/SFC
BOUNDARY...AND RECENT RADAR TRENDS HAVE SHOWN MORE CONVECTIVE
ACTIVITY/LIGHTNING STRIKES THERE...VS THE MORE SHOWER ACTIVITY
MOVING INTO THE CWA. THINGS WILL BECOME MORE STABILIZED...BUT CANT
COMPLETELY RULE OUT A FEW RUMBLES OF THUNDER WITH THE SYSTEM
MOVING RIGHT THROUGH. EVENTUALLY THE MAIN SFC BOUNDARY WILL PUSH
THROUGH...WITH MODELS IN DECENT AGREEMENT SHOWING THE FRONT
STARTING TO MOVE INTO THE WEST ARND 00Z...AND BY 12Z TOMORROW IS
ACROSS FAR ERN PORTIONS OF THE CWA. EXPECTING THAT THE
NORTHWESTERLY WINDS BEHIND THE FRONT BUILDING INTO THE CWA WILL BE
ON THE GUSTY SIDE...BUT NOT AS GUSTY AS IT MIGHT HAVE BEEN HAD IT
OCCURRED DURING THE DAYTIME HOURS. SPEEDS IN THE 15 TO 20 MPH
RANGE AND GUSTS CLOSER TO 25 MPH WILL BE POSSIBLE...ESP ACROSS THE
WRN THIRD TO HALF OF THE CWA.
KEPT LINGERING POPS IN DURING THE 06-12Z PERIOD TONIGHT...AS MODELS
HAVE BEEN FAIRLY CONSISTENT LATELY SHOWING THE SLOWER END TO THE
PRECIPITATION. NOT EXPECTING ANYTHING THAT IS REMAINING DURING
THIS TIME FRAME TO AMOUNT TO MUCH.
SHORTWAVE RIDGING BUILDING IN FROM THE WEST WILL BRING DRY
CONDITIONS DURING THE DAYTIME HOURS TOMORROW...AND IS LOOKING TO BE
A DECENT DAY. WILL SEE WHATEVER CLOUDS MAY STILL BE LINGERING
AROUND THE EAST IN THE MORNING FINALLY MOVE OFF...LEAVING MOSTLY
CLEAR SKIES BEHIND. NORTHERLY WINDS THROUGH THE DAY MAY STILL BE
ON THE GUSTY SIDE FOR AT LEAST PART OF THE DAY...BUT ARE EXPECTED
TO START TO DIMINISH DURING THE AFTERNOON. OVERNIGHT LOWS TONIGHT
ARE FORECAST TO FALL INTO THE 50S...WITH MID 70S GOING FOR HIGHS
TOMORROW.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 410 PM CDT MON SEP 23 2013
A WEAK RIDGE OF HIGH PRESSURE WILL SLIDE ACROSS THE LOCAL AREA
WEDNESDAY AND THURSDAY...AHEAD OF THE NEXT UPPER LEVEL DISTURBANCE
EXPECTED TO IMPACT THE CENTRAL PLAINS LATE IN THE WEEK. WHILE
THE SURFACE PRESSURE GRADIENT WILL REMAIN FAIRLY RELAXED TUESDAY
NIGHT...ALLOWING FOR MINIMAL MIXING AND GOOD RADIATIONAL
COOLING...EXPECT WINDS TO ONCE AGAIN INCREASE ACROSS MUCH OF THE
LOCAL AREA WEDNESDAY AND THURSDAY...AS THE PRESSURE GRADIENT WILL
TIGHTEN AHEAD OF THE DEEPENING LOW ACROSS THE INTERMOUNTAIN WEST.
THIS WILL RESULT IN A COUPLE OF BREEZY DAYS ACROSS THE LOCAL AREA
BOTH WEDNESDAY AND THURSDAY AFTERNOONS WITH TEMPERATURES SURGING
SEVERAL DEGREES ABOVE SEASONAL NORMS FOR LATE SEPTEMBER. THIS
SURGE IN TEMPERATURES WILL BE FAIRLY SHORT LIVED...HOWEVER...AS
INCREASING CLOUDS AND THE CHANCE FOR SHOWERS AND THUNDERSTORMS
RETURN TO THE FORECAST LATE THURSDAY NIGHT...AS A COLD FRONT
APPROACHES THE LOCAL AREA.
WHILE THE GLOBAL MODELS BEGIN TO DIVERGE SOME WITH THEIR HANDLING
OF THE MAIN UPPER LEVEL TROUGH THURSDAY NIGHT...WITH THE GEM/EC
BEING A BIT LESS PROGRESSIVE WITH THE UPPER LEVEL LOW...WENT AHEAD
AND MAINTAINED A CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE
LOCAL AREA THURSDAY NIGHT THROUGH SATURDAY AFTERNOON...AS THE MAIN
UPPER TROUGH WILL TAKE A COUPLE OF DAYS TO EXIT THE PLAINS. BEHIND
THE MAIN COLD FRONT...WHICH IS EXPECTED LATE FRIDAY AFTERNOON OR
NIGHT...EXPECT TEMPERATURES TO DROP OFF SEVERAL DEGREES...WITH
HIGH TEMPERATURES STRUGGLING TO CLIMB OUT OF THE 60S IN MANY
LOCATIONS... DESPITE THE ANTICIPATED CLEARING SKIES...SATURDAY
AFTERNOON. THEREAFTER...DRY NORTHWESTERLY FLOW IS EXPECTED TO FOR
THE LAST COUPLE OF DAYS OF THE EXTENDED FORECAST...WITH NO NOTABLE
DISTURBANCES EMBEDDED IN THIS FLOW TO WARRANT THE MENTION OF
ADDITIONAL CHANCES FOR PRECIPITATION.
FOR THE FRIDAY NIGHT/EARLY SATURDAY TIME PERIOD WHEN PRECIP
CHANCES LOOK THE GREATEST...INSTABILITY LOOKS MEAGER...AND
DECIDED TO KEEP THUNDERSTORM ACTIVITY ISOLATED IN THE FORECAST FOR
THE TIME BEING...WITH THE BEST CHANCE FOR ANY STRONG OR MORE
WIDESPREAD THUNDERSTORM ACTIVITY EXPECTED TO LIE IN THE VICINITY
OR JUST AHEAD OF THE FRONT FRIDAY NIGHT...GENERALLY ACROSS THE
SOUTHEASTERN QUADRANT OF THE LOCAL AREA.
&&
.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1230 AM CDT TUE SEP 24 2013
ALTHOUGH CONFIDENCE REMAINS HIGH IN VFR VISIBILITY THROUGH THE
NEXT 24 HOURS...CEILING TRENDS COULD BE A CHALLENGE ESPECIALLY
DURING THE NEXT 12 HOURS...AS THE LOCAL AREA IS CURRENTLY A MIXED
BAG OF CLEAR SKIES INTERSPERSED WITH PASSING BATCHES OF LOW
VFR...MVFR AND POSSIBLY EVEN IFR LOW CLOUDS. STRONGLY CONSIDERED
ADDING A PREVAILING MVFR CEILING FOR SEVERAL HOURS CENTERED
BETWEEN 12Z-18Z...BUT GIVEN LOW CONFIDENCE IN VARIOUS MODEL
SOLUTIONS AND OBSERVATIONAL TRENDS WILL ONLY RUN WITH A TEMPO MVFR
MENTION FROM 10Z-14Z FOR NOW...AND FURTHER EVALUATE PREVAILING
MVFR POTENTIAL WITH THE NEXT ROUTINE TAF ISSUANCE. IN GENERAL
HOWEVER...ANTICIPATE AT LEAST LOW-VFR CEILINGS TO REMAIN FAIRLY
PREVALENT THROUGH MID-DAY BEFORE LIFTING AND GRADUALLY SCATTERING
OUT DURING THE AFTERNOON HOURS...WITH HIGH CONFIDENCE IN NO WORSE
THAN CLEAR/MOSTLY CLEAR SKIES DURING AT LEAST THE FINAL 9 HOURS OF
THE PERIOD. AS FOR SURFACE WINDS...A PRONOUNCED SHIFT TO NORTHWEST
BREEZES WILL ARRIVE AT KGRI WITHIN THE NEXT FEW HOURS BEHIND A
PASSING COLD FRONT...WITH GUST POTENTIAL TO AT LEAST 22KT OR
HIGHER LASTING THROUGH MID-DAY BEFORE STEADILY DIMINISHING DURING
THE AFTERNOON AND BECOMING LIGHT/VARIABLE FOR TUESDAY EVENING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...ADO
LONG TERM...SAR
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
318 AM EDT TUE SEP 24 2013
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE SITTING OVER THE REGION WILL GRADUALLY
WEAKEN TODAY AND TONIGHT. A LOW PRESSURE SYSTEM WILL CROSS THE
SOUTHEAST STATES WEDNESDAY AND WEDNESDAY NIGHT... AS AN UPPER LEVEL
TROUGH TRACKS ACROSS THE CAROLINAS. HIGH PRESSURE WILL BUILD BACK
INTO THE REGION THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 225 AM TUESDAY...
FOR TODAY: RESIDUAL MOISTURE BENEATH THE SUBSIDENCE INVERSION ALOFT
AND MOIST ISENTROPIC UPGLIDE AROUND 295K HAS RESULTED IN AREALLY
EXPANDING STRATUS OVER CENTRAL/WRN VA AND WRN NC THIS MORNING...
QUICKLY SPREADING INTO THE NRN AND WRN PORTIONS OF THE FORECAST
AREA... WHICH WAS NOT DEPICTED WELL AT ALL BY THE NAM/GFS MODELS.
TRENDS SUPPORT A CONTINUED EXPANSION THROUGH DAYBREAK IN AREAS OVER
AND JUST EAST OF THE HIGHER TERRAIN... SO EXPECT PARTLY TO MOSTLY
CLOUDY SKIES FOR MOST AREAS ALONG AND NW OF I-85 IN THE NRN/NW CWA.
THE LATEST RUNS OF THE HRRR MODEL SHOW LOWER STRATUS FORMING OVER
NEARLY ALL OF CENTRAL NC DURING THE PREDAWN HOURS THIS MORNING...
MIXING OUT BY MID MORNING. HAVE EVIDENCE OF THIS DEVELOPMENT AS
YET... BUT BASED ON THE LACK OF WIND AND DEW POINTS STILL SITTING IN
THE 50-55 DEGREE RANGE... THIS IS CERTAINLY POSSIBLE. AT ANY RATE...
EXPECT AT LEAST PARTLY CLOUDY SKIES FOR MUCH OF THE CWA AROUND DAWN.
ONCE THESE CLOUDS MIX OUT WITH HEATING... WE SHOULD SEE MOSTLY SUNNY
SKIES TODAY WITH SCATTERED FLAT DIURNAL CUMULUS IN THE AFTERNOON.
SURFACE HIGH PRESSURE CENTERED OVER SRN ONTARIO/LAKE HURON WILL
WEAKEN TODAY BUT CONTINUE TO EXTEND SSE INTO CENTRAL/ERN NC...
ANCHORED DIRECTLY BENEATH STATIONARY BUT WEAKENING MID LEVEL
RIDGING. DESPITE THE CLOUDS THIS MORNING AND SCATTERED CLOUDS THIS
AFTERNOON... VERY DRY/STABLE AIR ALOFT AND NEUTRAL OR SUBSIDING
COLUMN WILL MAKE FOR A QUIET AND DRY DAY. LOW LEVEL THICKNESSES ARE
EXPECTED TO START THE DAY IN THE 1360-1365 M RANGE (AROUND 20 M
BELOW NORMAL)... RISING TO NEAR 1380 M... SUGGESTING HIGHS OF 75-80.
FOR TONIGHT: THE VORTEX NOW SPINNING OVER ERN NE/KS WILL CROSS THE
MID MISS VALLEY TONIGHT... BRINGING INCREASING (BUT STILL MODEST)
MID-UPPER LEVEL DIVERGENT FLOW INTO THE WRN CAROLINAS... WHILE AT
THE SURFACE... THE WEAKENING RIDGE STILL NOSES SOUTHWARD INTO THE
AREA. THE OCCLUDING SURFACE FRONTAL SYSTEM WILL PUSH THROUGH THE
LOWER MISS VALLEY INTO MS/AL LATE TONIGHT WHILE SECONDARY LOW
PRESSURE BEGINS TO DEEPEN JUST OFF JAX... ALONG THE EAST-WEST
FRONTAL ZONE. THE TIGHTENING MSLP GRADIENT SHOULD HOLD MOSTLY TO OUR
SOUTH... LEAVING A PERSISTENT LIGHT/VARIABLE SURFACE FLOW OVER NC.
WITH SURFACE DEW POINTS STEADILY RISING... EXPECT ANOTHER ROUND OF
PATCHY STRATUS AND FOG DEVELOPMENT OVERNIGHT. THIS ALONG WITH THE
INCREASING MID-HIGH CLOUDS SPREADING IN FROM THE WEST WILL RESULT IN
A TREND TO PARTLY CLOUDY SKIES... WITH MOSTLY CLOUDY IN THE WRN CWA
NEAR THE BETTER POOLING OF LOW LEVEL MOISTURE JUST EAST OF THE
HIGHER TERRAIN. WILL STAY WITH A DRY FORECAST GIVEN THE STILL-LOW PW
VALUES AND LACK OF FORCING FOR ASCENT. EXPECT LOWS FROM 49 NE TO 57
WEST... A BLEND OF STATISTICAL GUIDANCE. -GIH
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 310 AM TUESDAY...
THE MID LEVEL VORTEX IS EXPECTED TO UNDERCUT THE ONTARIO-TO-
MIDATLANTIC RIDGE ALOFT... MOVING FROM SRN IL ACROSS KY AND OVER
VA/NC THROUGH WED NIGHT... BRINGING WEAK MID LEVEL DPVA AND WEAK
UPPER DIVERGENCE OVER AREA. MEANWHILE... AT THE SURFACE... THE
OCCLUDED FRONTAL SYSTEM OVER THE LOWER MISS VALLEY EXTENDING SOUTH
OF LA WED MORNING WEAKENS AND FILLS AS IT SHIFTS SLOWLY EAST...
WHILE THE LOW OFF JAX ALONG THE FRONT CONTINUES TO STRENGTHEN AS IT
TOO DRIFTS EASTWARD. DURING ALL OF THIS... CENTRAL NC REMAINS
INFLUENCED PRIMARILY BY THE LOW LEVEL RIDGE NOSING IN FROM THE
NORTH... WITH A WEAK BUT STEADY FEED OF LOW LEVEL DRY AIR VIA THE
NORTHEAST FLOW. THE RIDGE AXIS DOES ADJUST WITH THE SURFACE FLOW
BACKING TO MORE NORTHERLY AS THE LOW DEEPENS OFF THE SOUTHEAST
COAST... BUT FORECAST SOUNDINGS INDICATE CONTINUED FAIRLY DRY AIR
THROUGHOUT THE LOWEST 8000 FT OF THE COLUMN. WE ARE LIKELY TO SEE
OVERCAST MID LEVEL CLOUDINESS THROUGHOUT THE DAY AND NIGHT... AND
THE DPVA ALONG WITH STEEPENING LAPSE RATES ABOVE THE 0C LEVEL MAY
RESULT IN CONSIDERABLE VIRGA WED AFTERNOON THROUGH THE NIGHT. BUT
APART FROM THE FAR WRN CWA WHERE UP-TERRAIN FLOW MAY ALLOW FOR
ENOUGH LOWER LEVEL MOISTENING TO SUPPORT PATCHY LIGHT RAIN... IT
LOOKS LIKE THE REMAINDER OF CENTRAL NC WILL HAVE TOO MUCH DRY AIR
BELOW 8000 FT TO SUPPORT ANYTHING MORE THAN A FEW SPRINKLES. WILL
NUDGE POPS DOWN AREAWIDE... WITH CHANCE POPS CONFINED TO THE FAR
WEST AND SW CWA... TRENDING TO SLIGHT OR NO POPS FROM THE TRIANGLE
NORTH AND EAST WITH LITTLE TO NO MEASURABLE RAIN EXPECTED. THE
CLOUDS WILL LOWER THE DIURNAL TEMP RANGE... AND EXPECT HIGHS IN THE
LOW-MID 70S (IN LINE WITH THICKNESSES ABOUT 10 M BELOW NORMAL) AND
LOWS 54-60. -GIH
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 315 AM TUESDAY...
A SHORTWAVE TROUGH AXIS PASSING OVERHEAD EARLY THURSDAY WILL LEAD TO
INCREASING SUBSIDENCE AND DRYING DURING THE DAY...WITH LINGERING
LIGHT PRECIP MOVING TO THE COAST. LACK OF SIGNIFICANT PRECIP SHOULD
LIMIT THE STRENGTHEN OF A COLD AIR DAMMING-LIKE AIRMASS NEAR THE
SURFACE...SO THERE SHOULD BE CLEARING FROM THE NORTH THURSDAY
AFTERNOON/EVENING...WITH THE BULK OF THE CLOUD COVER ATTRIBUTABLE TO
THE UPPER TROUGH. TEMPS ARE A LITTLE TRICKY GIVEN THAT INITIAL
CLOUD COVER IS SOMEWHAT DEPENDENT ON PRECIP WEDNESDAY/WEDNESDAY
NIGHT AND A NORTHEASTERLY WIND WILL PREVAIL. HOWEVER...WITH
CLEARING...GUIDANCE SUGGESTS MID/UPPER 70S ARE POSSIBLE
WITH HEATING. WILL KEEP HIGHS A LITTLE BELOW GUIDANCE IN THE 73-77
RANGE. LOWS THURSDAY NIGHT IN THE LOW TO MID 50S.
FRIDAY THROUGH MONDAY...
MODELS ARE IN GOOD AGREEMENT REGARDING THE LONGWAVE PATTERN THIS
WEEKEND...WITH A HIGHLY AMPLIFIED RIDGE WEST OF THE MOUNTAINS AND AN
UPPER TROUGH/LOW OFF THE EAST COAST. BETWEEN THESE FEATURES...DEEP
NORTH-NORTHEASTERLY FLOW WILL PREVAIL...WITH DEEPER MOISTURE TO STAY
OFFSHORE. THE ECMWF HAS TRENDED STRONGER WITH AN UPPER LOW FORECAST
TO DEVELOP WITHIN THE TROUGH FRIDAY AND DRIFT NORTH ALONG THE EAST
COAST BY SUNDAY/MONDAY. THE ASSOCIATED SURFACE LOW WOULD BRING
BETTER MOISTURE WESTWARD INTO THE COASTAL PLAIN MONDAY...WHILE A
COLD FRONT OVER THE MIDWEST SLOWLY APPROACHES NC FROM THE WEST.
HOWEVER...MODELS STILL KEEP NC DRY BETWEEN THESE FEATURES THROUGH
MONDAY. PERSISTENT COLD ADVECTION ASSOCIATED WITH THE NORTHEASTERLY
FLOW WILL 850MB TEMPS DOWN TO 7-8C...WITH LOW LEVEL THICKNESSES IN
THE 1360-1365M RANGE EACH MORNING. THESE PARAMETERS SUGGEST TEMPS A
CATEGORY BELOW NORMAL...WITH LOW TO MID 70S LIKELY SATURDAY AND
SUNDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 1250 AM TUESDAY...
REST OF TONIGHT: VFR STRATUS CONTINUES TO EXPAND IN AREA OVER
CENTRAL VA INTO WRN NC... AND BASED ON THIS TREND APPEARS POISED TO
SPREAD INTO INT/GSO AND PERHAPS RDU AS WELL OVERNIGHT. PATCHY VFR
CLOUDS AFFECTED FAY EARLIER AND ADDITIONAL CLOUDS REMAIN POSSIBLE
THROUGH DAYBREAK. MEANWHILE... BANKS OF SHALLOW DENSE FOG HAVE
FORMED NEAR RWI -- PROMPTED BY THE NEARBY RIVER -- AND THIS FOG
SHOULD PERSIST OVERNIGHT... WITH VSBYS MOSTLY IFR BUT VARYING
BETWEEN LIFR AND MVFR THROUGH DAYBREAK. HRRR MODEL DEPICTS LOW IFR
STRATUS SPREADING ACROSS ALL OF CENTRAL NC OVERNIGHT... AND WHILE
THIS LOOKS OVERDONE... WE WILL KEEP A CLOSE EYE ON CLOUD TRENDS
THROUGH THE REST OF THE NIGHT.
AFTER 12Z: VFR THROUGH AT LEAST THIS EVENING. ANY MORNING STRATUS
WILL MIX OUT BY 14Z WITH THE ONSET OF HEATING... THEN ANOTHER ROUND
OF MOSTLY SCATTERED FLAT CUMULUS BASED AROUND 4000 FT AGL IS
EXPECTED THIS AFTERNOON... AS THE MID/UPPER LEVELS STAY STABLE AND
VERY DRY WHILE A THIN MOIST LAYER PERSISTS BENEATH THE SUBSIDENCE
INVERSION ALOFT. THEN AFTER SUNSET... STABILIZING LOW LEVELS (LOWEST
4000 FT) AND VERY LIGHT WINDS WITH INCREASING NEAR-SURFACE MOISTURE
WILL BRING A RISK OF MVFR FOG TONIGHT... ALTHOUGH THE BETTER CHANCE
OF ADVERSE AVIATION CONDITIONS WILL HOLD OFF UNTIL AFTER 06Z
TONIGHT. HIGH CLOUDS BASED ABOVE 15000 FT AGL WILL SPREAD IN FROM
THE WEST TONIGHT. WINDS WILL BE VARIABLE IN DIRECTION THROUGH THE
PERIOD AT SPEEDS UNDER 7 KTS.
LOOKING BEYOND 06Z EARLY WEDNESDAY MORNING: PATCHY LOW STRATUS AND
FOG ARE POSSIBLE THROUGH MID MORNING... PARTICULARLY NEAR BODIES OF
WATER WHERE SHALLOW DENSE GROUND FOG MAY FORM PRIOR TO DAYBREAK. ANY
SUCH CLOUDS SHOULD MIX OUT BEFORE 15Z WITH VFR CONDITIONS
RETURNING... ALTHOUGH WE WILL SEE AN INCREASE IN STRATOCUMULUS BASED
AROUND 3500 FT AGL ALONG WITH THICKENING AND LOWERING MID CLOUDS AS
A STORM SYSTEM APPROACHES WEDNESDAY. IN GENERAL... VFR CONDITIONS
WILL DOMINATE AS THIS SYSTEM CROSSES THE SOUTHEAST AND CAROLINAS...
WITH CLOUD BASES MOSTLY ABOVE 3500 FT WITH LIGHT SHOWERS. THIS
SYSTEM WILL EXIT ON THURSDAY WITH NEW HIGH PRESSURE RIDGING BUILDING
IN AT THE SURFACE. SHALLOW FOG IS POSSIBLE EARLY FRIDAY MORNING WITH
HIGH SURFACE RH AND LIGHT WINDS... BUT OTHERWISE EXPECT VFR
CONDITIONS FRIDAY THROUGH SATURDAY BENEATH THE HIGH PRESSURE RIDGE.
-GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...22
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
315 AM EDT TUE SEP 24 2013
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE SITTING OVER THE REGION WILL GRADUALLY
WEAKEN TODAY AND TONIGHT. A LOW PRESSURE SYSTEM WILL CROSS THE
SOUTHEAST STATES WEDNESDAY AND WEDNESDAY NIGHT... AS AN UPPER LEVEL
TROUGH TRACKS ACROSS THE CAROLINAS. HIGH PRESSURE WILL BUILD BACK
INTO THE REGION THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 225 AM TUESDAY...
FOR TODAY: RESIDUAL MOISTURE BENEATH THE SUBSIDENCE INVERSION ALOFT
AND MOIST ISENTROPIC UPGLIDE AROUND 295K HAS RESULTED IN AREALLY
EXPANDING STRATUS OVER CENTRAL/WRN VA AND WRN NC THIS MORNING...
QUICKLY SPREADING INTO THE NRN AND WRN PORTIONS OF THE FORECAST
AREA... WHICH WAS NOT DEPICTED WELL AT ALL BY THE NAM/GFS MODELS.
TRENDS SUPPORT A CONTINUED EXPANSION THROUGH DAYBREAK IN AREAS OVER
AND JUST EAST OF THE HIGHER TERRAIN... SO EXPECT PARTLY TO MOSTLY
CLOUDY SKIES FOR MOST AREAS ALONG AND NW OF I-85 IN THE NRN/NW CWA.
THE LATEST RUNS OF THE HRRR MODEL SHOW LOWER STRATUS FORMING OVER
NEARLY ALL OF CENTRAL NC DURING THE PREDAWN HOURS THIS MORNING...
MIXING OUT BY MID MORNING. HAVE EVIDENCE OF THIS DEVELOPMENT AS
YET... BUT BASED ON THE LACK OF WIND AND DEW POINTS STILL SITTING IN
THE 50-55 DEGREE RANGE... THIS IS CERTAINLY POSSIBLE. AT ANY RATE...
EXPECT AT LEAST PARTLY CLOUDY SKIES FOR MUCH OF THE CWA AROUND DAWN.
ONCE THESE CLOUDS MIX OUT WITH HEATING... WE SHOULD SEE MOSTLY SUNNY
SKIES TODAY WITH SCATTERED FLAT DIURNAL CUMULUS IN THE AFTERNOON.
SURFACE HIGH PRESSURE CENTERED OVER SRN ONTARIO/LAKE HURON WILL
WEAKEN TODAY BUT CONTINUE TO EXTEND SSE INTO CENTRAL/ERN NC...
ANCHORED DIRECTLY BENEATH STATIONARY BUT WEAKENING MID LEVEL
RIDGING. DESPITE THE CLOUDS THIS MORNING AND SCATTERED CLOUDS THIS
AFTERNOON... VERY DRY/STABLE AIR ALOFT AND NEUTRAL OR SUBSIDING
COLUMN WILL MAKE FOR A QUIET AND DRY DAY. LOW LEVEL THICKNESSES ARE
EXPECTED TO START THE DAY IN THE 1360-1365 M RANGE (AROUND 20 M
BELOW NORMAL)... RISING TO NEAR 1380 M... SUGGESTING HIGHS OF 75-80.
FOR TONIGHT: THE VORTEX NOW SPINNING OVER ERN NE/KS WILL CROSS THE
MID MISS VALLEY TONIGHT... BRINGING INCREASING (BUT STILL MODEST)
MID-UPPER LEVEL DIVERGENT FLOW INTO THE WRN CAROLINAS... WHILE AT
THE SURFACE... THE WEAKENING RIDGE STILL NOSES SOUTHWARD INTO THE
AREA. THE OCCLUDING SURFACE FRONTAL SYSTEM WILL PUSH THROUGH THE
LOWER MISS VALLEY INTO MS/AL LATE TONIGHT WHILE SECONDARY LOW
PRESSURE BEGINS TO DEEPEN JUST OFF JAX... ALONG THE EAST-WEST
FRONTAL ZONE. THE TIGHTENING MSLP GRADIENT SHOULD HOLD MOSTLY TO OUR
SOUTH... LEAVING A PERSISTENT LIGHT/VARIABLE SURFACE FLOW OVER NC.
WITH SURFACE DEW POINTS STEADILY RISING... EXPECT ANOTHER ROUND OF
PATCHY STRATUS AND FOG DEVELOPMENT OVERNIGHT. THIS ALONG WITH THE
INCREASING MID-HIGH CLOUDS SPREADING IN FROM THE WEST WILL RESULT IN
A TREND TO PARTLY CLOUDY SKIES... WITH MOSTLY CLOUDY IN THE WRN CWA
NEAR THE BETTER POOLING OF LOW LEVEL MOISTURE JUST EAST OF THE
HIGHER TERRAIN. WILL STAY WITH A DRY FORECAST GIVEN THE STILL-LOW PW
VALUES AND LACK OF FORCING FOR ASCENT. EXPECT LOWS FROM 49 NE TO 57
WEST... A BLEND OF STATISTICAL GUIDANCE. -GIH
&&
.SHORT TERM / /...
AS OF 325 PM MONDAY...
TO BE UPDATED SHORTLY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 315 AM TUESDAY...
A SHORTWAVE TROUGH AXIS PASSING OVERHEAD EARLY THURSDAY WILL LEAD TO
INCREASING SUBSIDENCE AND DRYING DURING THE DAY...WITH LINGERING
LIGHT PRECIP MOVING TO THE COAST. LACK OF SIGNIFICANT PRECIP SHOULD
LIMIT THE STRENGTHEN OF A COLD AIR DAMMING-LIKE AIRMASS NEAR THE
SURFACE...SO THERE SHOULD BE CLEARING FROM THE NORTH THURSDAY
AFTERNOON/EVENING...WITH THE BULK OF THE CLOUD COVER ATTRIBUTABLE TO
THE UPPER TROUGH. TEMPS ARE A LITTLE TRICKY GIVEN THAT INITIAL
CLOUD COVER IS SOMEWHAT DEPENDENT ON PRECIP WEDNESDAY/WEDNESDAY
NIGHT AND A NORTHEASTERLY WIND WILL PREVAIL. HOWEVER...WITH
CLEARING...GUIDANCE SUGGESTS MID/UPPER 70S ARE POSSIBLE
WITH HEATING. WILL KEEP HIGHS A LITTLE BELOW GUIDANCE IN THE 73-77
RANGE. LOWS THURSDAY NIGHT IN THE LOW TO MID 50S.
FRIDAY THROUGH MONDAY...
MODELS ARE IN GOOD AGREEMENT REGARDING THE LONGWAVE PATTERN THIS
WEEKEND...WITH A HIGHLY AMPLIFIED RIDGE WEST OF THE MOUNTAINS AND AN
UPPER TROUGH/LOW OFF THE EAST COAST. BETWEEN THESE FEATURES...DEEP
NORTH-NORTHEASTERLY FLOW WILL PREVAIL...WITH DEEPER MOISTURE TO STAY
OFFSHORE. THE ECMWF HAS TRENDED STRONGER WITH AN UPPER LOW FORECAST
TO DEVELOP WITHIN THE TROUGH FRIDAY AND DRIFT NORTH ALONG THE EAST
COAST BY SUNDAY/MONDAY. THE ASSOCIATED SURFACE LOW WOULD BRING
BETTER MOISTURE WESTWARD INTO THE COASTAL PLAIN MONDAY...WHILE A
COLD FRONT OVER THE MIDWEST SLOWLY APPROACHES NC FROM THE WEST.
HOWEVER...MODELS STILL KEEP NC DRY BETWEEN THESE FEATURES THROUGH
MONDAY. PERSISTENT COLD ADVECTION ASSOCIATED WITH THE NORTHEASTERLY
FLOW WILL 850MB TEMPS DOWN TO 7-8C...WITH LOW LEVEL THICKNESSES IN
THE 1360-1365M RANGE EACH MORNING. THESE PARAMETERS SUGGEST TEMPS A
CATEGORY BELOW NORMAL...WITH LOW TO MID 70S LIKELY SATURDAY AND
SUNDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 1250 AM TUESDAY...
REST OF TONIGHT: VFR STRATUS CONTINUES TO EXPAND IN AREA OVER
CENTRAL VA INTO WRN NC... AND BASED ON THIS TREND APPEARS POISED TO
SPREAD INTO INT/GSO AND PERHAPS RDU AS WELL OVERNIGHT. PATCHY VFR
CLOUDS AFFECTED FAY EARLIER AND ADDITIONAL CLOUDS REMAIN POSSIBLE
THROUGH DAYBREAK. MEANWHILE... BANKS OF SHALLOW DENSE FOG HAVE
FORMED NEAR RWI -- PROMPTED BY THE NEARBY RIVER -- AND THIS FOG
SHOULD PERSIST OVERNIGHT... WITH VSBYS MOSTLY IFR BUT VARYING
BETWEEN LIFR AND MVFR THROUGH DAYBREAK. HRRR MODEL DEPICTS LOW IFR
STRATUS SPREADING ACROSS ALL OF CENTRAL NC OVERNIGHT... AND WHILE
THIS LOOKS OVERDONE... WE WILL KEEP A CLOSE EYE ON CLOUD TRENDS
THROUGH THE REST OF THE NIGHT.
AFTER 12Z: VFR THROUGH AT LEAST THIS EVENING. ANY MORNING STRATUS
WILL MIX OUT BY 14Z WITH THE ONSET OF HEATING... THEN ANOTHER ROUND
OF MOSTLY SCATTERED FLAT CUMULUS BASED AROUND 4000 FT AGL IS
EXPECTED THIS AFTERNOON... AS THE MID/UPPER LEVELS STAY STABLE AND
VERY DRY WHILE A THIN MOIST LAYER PERSISTS BENEATH THE SUBSIDENCE
INVERSION ALOFT. THEN AFTER SUNSET... STABILIZING LOW LEVELS (LOWEST
4000 FT) AND VERY LIGHT WINDS WITH INCREASING NEAR-SURFACE MOISTURE
WILL BRING A RISK OF MVFR FOG TONIGHT... ALTHOUGH THE BETTER CHANCE
OF ADVERSE AVIATION CONDITIONS WILL HOLD OFF UNTIL AFTER 06Z
TONIGHT. HIGH CLOUDS BASED ABOVE 15000 FT AGL WILL SPREAD IN FROM
THE WEST TONIGHT. WINDS WILL BE VARIABLE IN DIRECTION THROUGH THE
PERIOD AT SPEEDS UNDER 7 KTS.
LOOKING BEYOND 06Z EARLY WEDNESDAY MORNING: PATCHY LOW STRATUS AND
FOG ARE POSSIBLE THROUGH MID MORNING... PARTICULARLY NEAR BODIES OF
WATER WHERE SHALLOW DENSE GROUND FOG MAY FORM PRIOR TO DAYBREAK. ANY
SUCH CLOUDS SHOULD MIX OUT BEFORE 15Z WITH VFR CONDITIONS
RETURNING... ALTHOUGH WE WILL SEE AN INCREASE IN STRATOCUMULUS BASED
AROUND 3500 FT AGL ALONG WITH THICKENING AND LOWERING MID CLOUDS AS
A STORM SYSTEM APPROACHES WEDNESDAY. IN GENERAL... VFR CONDITIONS
WILL DOMINATE AS THIS SYSTEM CROSSES THE SOUTHEAST AND CAROLINAS...
WITH CLOUD BASES MOSTLY ABOVE 3500 FT WITH LIGHT SHOWERS. THIS
SYSTEM WILL EXIT ON THURSDAY WITH NEW HIGH PRESSURE RIDGING BUILDING
IN AT THE SURFACE. SHALLOW FOG IS POSSIBLE EARLY FRIDAY MORNING WITH
HIGH SURFACE RH AND LIGHT WINDS... BUT OTHERWISE EXPECT VFR
CONDITIONS FRIDAY THROUGH SATURDAY BENEATH THE HIGH PRESSURE RIDGE.
-GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...
LONG TERM...22
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
228 AM EDT TUE SEP 24 2013
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE SITTING OVER THE REGION WILL GRADUALLY
WEAKEN TODAY AND TONIGHT. A LOW PRESSURE SYSTEM WILL CROSS THE
SOUTHEAST STATES WEDNESDAY AND WEDNESDAY NIGHT... AS AN UPPER LEVEL
TROUGH TRACKS ACROSS THE CAROLINAS. HIGH PRESSURE WILL BUILD BACK
INTO THE REGION THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 225 AM TUESDAY...
FOR TODAY: RESIDUAL MOISTURE BENEATH THE SUBSIDENCE INVERSION ALOFT
AND MOIST ISENTROPIC UPGLIDE AROUND 295K HAS RESULTED IN AREALLY
EXPANDING STRATUS OVER CENTRAL/WRN VA AND WRN NC THIS MORNING...
QUICKLY SPREADING INTO THE NRN AND WRN PORTIONS OF THE FORECAST
AREA... WHICH WAS NOT DEPICTED WELL AT ALL BY THE NAM/GFS MODELS.
TRENDS SUPPORT A CONTINUED EXPANSION THROUGH DAYBREAK IN AREAS OVER
AND JUST EAST OF THE HIGHER TERRAIN... SO EXPECT PARTLY TO MOSTLY
CLOUDY SKIES FOR MOST AREAS ALONG AND NW OF I-85 IN THE NRN/NW CWA.
THE LATEST RUNS OF THE HRRR MODEL SHOW LOWER STRATUS FORMING OVER
NEARLY ALL OF CENTRAL NC DURING THE PREDAWN HOURS THIS MORNING...
MIXING OUT BY MID MORNING. HAVE EVIDENCE OF THIS DEVELOPMENT AS
YET... BUT BASED ON THE LACK OF WIND AND DEW POINTS STILL SITTING IN
THE 50-55 DEGREE RANGE... THIS IS CERTAINLY POSSIBLE. AT ANY RATE...
EXPECT AT LEAST PARTLY CLOUDY SKIES FOR MUCH OF THE CWA AROUND DAWN.
ONCE THESE CLOUDS MIX OUT WITH HEATING... WE SHOULD SEE MOSTLY SUNNY
SKIES TODAY WITH SCATTERED FLAT DIURNAL CUMULUS IN THE AFTERNOON.
SURFACE HIGH PRESSURE CENTERED OVER SRN ONTARIO/LAKE HURON WILL
WEAKEN TODAY BUT CONTINUE TO EXTEND SSE INTO CENTRAL/ERN NC...
ANCHORED DIRECTLY BENEATH STATIONARY BUT WEAKENING MID LEVEL
RIDGING. DESPITE THE CLOUDS THIS MORNING AND SCATTERED CLOUDS THIS
AFTERNOON... VERY DRY/STABLE AIR ALOFT AND NEUTRAL OR SUBSIDING
COLUMN WILL MAKE FOR A QUIET AND DRY DAY. LOW LEVEL THICKNESSES ARE
EXPECTED TO START THE DAY IN THE 1360-1365 M RANGE (AROUND 20 M
BELOW NORMAL)... RISING TO NEAR 1380 M... SUGGESTING HIGHS OF 75-80.
FOR TONIGHT: THE VORTEX NOW SPINNING OVER ERN NE/KS WILL CROSS THE
MID MISS VALLEY TONIGHT... BRINGING INCREASING (BUT STILL MODEST)
MID-UPPER LEVEL DIVERGENT FLOW INTO THE WRN CAROLINAS... WHILE AT
THE SURFACE... THE WEAKENING RIDGE STILL NOSES SOUTHWARD INTO THE
AREA. THE OCCLUDING SURFACE FRONTAL SYSTEM WILL PUSH THROUGH THE
LOWER MISS VALLEY INTO MS/AL LATE TONIGHT WHILE SECONDARY LOW
PRESSURE BEGINS TO DEEPEN JUST OFF JAX... ALONG THE EAST-WEST
FRONTAL ZONE. THE TIGHTENING MSLP GRADIENT SHOULD HOLD MOSTLY TO OUR
SOUTH... LEAVING A PERSISTENT LIGHT/VARIABLE SURFACE FLOW OVER NC.
WITH SURFACE DEW POINTS STEADILY RISING... EXPECT ANOTHER ROUND OF
PATCHY STRATUS AND FOG DEVELOPMENT OVERNIGHT. THIS ALONG WITH THE
INCREASING MID-HIGH CLOUDS SPREADING IN FROM THE WEST WILL RESULT IN
A TREND TO PARTLY CLOUDY SKIES... WITH MOSTLY CLOUDY IN THE WRN CWA
NEAR THE BETTER POOLING OF LOW LEVEL MOISTURE JUST EAST OF THE
HIGHER TERRAIN. WILL STAY WITH A DRY FORECAST GIVEN THE STILL-LOW PW
VALUES AND LACK OF FORCING FOR ASCENT. EXPECT LOWS FROM 49 NE TO 57
WEST... A BLEND OF STATISTICAL GUIDANCE. -GIH
&&
.SHORT TERM / /...
AS OF 325 PM MONDAY...
TO BE UPDATED SHORTLY.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 245 PM MONDAY...
CONFIDENCE IN AN UNSETTLED PATTERN FOR WEDNESDAY INTO A PORTION OF
THURSDAY HAS INCREASED A BIT TODAY. MOST MODELS ARE INDICATING A
MID/UPPER TROUGH AMPLIFICATION OVER THE EASTERN STATES... SHIFTING
OFFSHORE LATE WEEK. THE IMPORTANT SURFACE WAVE IS STILL SUPPORTED TO
DEVELOP/TRACK WELL TO OUR SOUTH AND EAST... FROM THE GULF COAST 12Z
WEDNESDAY... EAST ACROSS NORTHERN FLORIDA EARLY THURSDAY... THEN OFF
THE SOUTH ATLANTIC COAST FRIDAY. THE EC CONTINUES TO BE THE FAVORED
MODEL OF CHOICE CONCERNING OPERATIONAL RUNS DUE TO ITS CONSISTENCY
WITH THE EVOLUTION OF THE SYSTEM IN RECENT DAYS THROUGH TODAY. MOST
OF THE HEAVY RAIN WITH THIS SYSTEM SHOULD BE CONFINED TO THE DEEP
SOUTH AND POSSIBLY INTO SC AS THE MAIN LOW LEVEL BOUNDARY WILL BE
HUNG UP THERE. HOWEVER... THERE IS STILL A GOOD CHANCE OF RAIN WITH
THE MID/UPPER SUPPORT ALONG WITH ISENTROPIC LIFT WED-WED NIGHT.
AFTER THE LOW MOVES OFFSHORE... ANOTHER MID/UPPER LOW MAY AGAIN
TARGET THE GREAT LAKES AND MIDWEST SUPPORTED BY TELECONNECTIONS WITH
THE NE PAC UPPER TROUGH... AND DOWNSTREAM UPPER RIDGE DEVELOPMENT
OVER THE ROCKIES. THIS MAY LEAD TO MORE IN THE WAY OF UNSETTLED
CONDITIONS LATER SUNDAY INTO EARLY NEXT WEEK.
SENSIBLE WEATHER FOR CENTRAL NC SHOULD CONSIST OF THE HIGHEST
CHANCES OF RAIN ON WEDNESDAY INTO WEDNESDAY NIGHT... ASSOCIATED WITH
THE MID/UPPER TROUGH. THEN THE HIGHEST POP IN THE EAST ON THURSDAY
(MAINLY MORNING) WITH THE SURFACE WAVE TRACKING TO OUR SOUTH AND
EAST AND OFFSHORE THEN. IT IS STILL TOO EARLY TO FORECAST A FULL
BLOWN COLD AIR DAMMING EVENT THAT WOULD BE OF IN-SITU OR POSSIBLY
HYBRID NATURE WED INTO THU... GIVEN THE LACK OF A SUPPORTING PARENT
SURFACE HIGH THAT WOULD BE STRONG ENOUGH... AND IN THE PREFERRED
LOCATION FOR ANYTHING MORE IN OUR REGION. THE DEVELOPMENT OF AN
IN-SITU OR WEAK HYBRID CAD EVENT SHOULD BE HIGHLY DEPENDENT BY THE
QPF ON WED... WHICH IS STILL VERY MUCH IN QUESTION... AND IS STILL
EXPECTED TO BE LESS THAN 0.25 OF AN INCH IN THE DAMMING REGION. DUE
TO THE LACK OF CONFIDENCE ON ANYTHING MORE THAN 0.25 OF AN INCH OF
RAIN WED-WED NIGHT AT THE CURRENT TIME... WE WILL MAINTAIN POP IN
THE CHANCE TO HIGH CHANCE CATEGORY... QPF OF LESS THAN 0.25 OF AN
INCH... AND TEMPERATURES (WHILE COOLER THAN NORMAL)... NOT BY MUCH
(2-5 DEGREES OR SO FOR DAYTIME HIGHS).
GIVEN THE EXPECTATION OF A WEAK CAD AT BEST... SKIES SHOULD CLEAR
MORE QUICKLY LATE THU AND FRI AS THE STORM SHIFTS WELL OFFSHORE.
LOWS WILL COOL INTO THE LOWER TO MID 50S FRI... WITH HIGHS IN THE
MID 70S WITH MOSTLY SUNNY SKIES FRI. SAT-SUN... SKIES SHOULD
CONTINUE MOSTLY CLEAR/MOSTLY SUNNY AS HIGH PRESSURE IS EXPECTED TO
EXTEND DOWN THE EASTERN SEABOARD INTO SUNDAY. LOWS IN THE LOWER TO
MID 50S AND HIGHS IN THE LOWER TO MID 70S ARE EXPECTED.
SUNDAY NIGHT AND MONDAY... EXPECT SOME INCREASE IN CLOUDINESS FOR
NOW... POSSIBLY A CHANCE OF RAIN AGAIN - BUT UNCERTAINTY THIS FAR
OUT SUPPORTS A SLIGHT CHANCE OF SHOWERS IN THE FORECAST MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 1250 AM TUESDAY...
REST OF TONIGHT: VFR STRATUS CONTINUES TO EXPAND IN AREA OVER
CENTRAL VA INTO WRN NC... AND BASED ON THIS TREND APPEARS POISED TO
SPREAD INTO INT/GSO AND PERHAPS RDU AS WELL OVERNIGHT. PATCHY VFR
CLOUDS AFFECTED FAY EARLIER AND ADDITIONAL CLOUDS REMAIN POSSIBLE
THROUGH DAYBREAK. MEANWHILE... BANKS OF SHALLOW DENSE FOG HAVE
FORMED NEAR RWI -- PROMPTED BY THE NEARBY RIVER -- AND THIS FOG
SHOULD PERSIST OVERNIGHT... WITH VSBYS MOSTLY IFR BUT VARYING
BETWEEN LIFR AND MVFR THROUGH DAYBREAK. HRRR MODEL DEPICTS LOW IFR
STRATUS SPREADING ACROSS ALL OF CENTRAL NC OVERNIGHT... AND WHILE
THIS LOOKS OVERDONE... WE WILL KEEP A CLOSE EYE ON CLOUD TRENDS
THROUGH THE REST OF THE NIGHT.
AFTER 12Z: VFR THROUGH AT LEAST THIS EVENING. ANY MORNING STRATUS
WILL MIX OUT BY 14Z WITH THE ONSET OF HEATING... THEN ANOTHER ROUND
OF MOSTLY SCATTERED FLAT CUMULUS BASED AROUND 4000 FT AGL IS
EXPECTED THIS AFTERNOON... AS THE MID/UPPER LEVELS STAY STABLE AND
VERY DRY WHILE A THIN MOIST LAYER PERSISTS BENEATH THE SUBSIDENCE
INVERSION ALOFT. THEN AFTER SUNSET... STABILIZING LOW LEVELS (LOWEST
4000 FT) AND VERY LIGHT WINDS WITH INCREASING NEAR-SURFACE MOISTURE
WILL BRING A RISK OF MVFR FOG TONIGHT... ALTHOUGH THE BETTER CHANCE
OF ADVERSE AVIATION CONDITIONS WILL HOLD OFF UNTIL AFTER 06Z
TONIGHT. HIGH CLOUDS BASED ABOVE 15000 FT AGL WILL SPREAD IN FROM
THE WEST TONIGHT. WINDS WILL BE VARIABLE IN DIRECTION THROUGH THE
PERIOD AT SPEEDS UNDER 7 KTS.
LOOKING BEYOND 06Z EARLY WEDNESDAY MORNING: PATCHY LOW STRATUS AND
FOG ARE POSSIBLE THROUGH MID MORNING... PARTICULARLY NEAR BODIES OF
WATER WHERE SHALLOW DENSE GROUND FOG MAY FORM PRIOR TO DAYBREAK. ANY
SUCH CLOUDS SHOULD MIX OUT BEFORE 15Z WITH VFR CONDITIONS
RETURNING... ALTHOUGH WE WILL SEE AN INCREASE IN STRATOCUMULUS BASED
AROUND 3500 FT AGL ALONG WITH THICKENING AND LOWERING MID CLOUDS AS
A STORM SYSTEM APPROACHES WEDNESDAY. IN GENERAL... VFR CONDITIONS
WILL DOMINATE AS THIS SYSTEM CROSSES THE SOUTHEAST AND CAROLINAS...
WITH CLOUD BASES MOSTLY ABOVE 3500 FT WITH LIGHT SHOWERS. THIS
SYSTEM WILL EXIT ON THURSDAY WITH NEW HIGH PRESSURE RIDGING BUILDING
IN AT THE SURFACE. SHALLOW FOG IS POSSIBLE EARLY FRIDAY MORNING WITH
HIGH SURFACE RH AND LIGHT WINDS... BUT OTHERWISE EXPECT VFR
CONDITIONS FRIDAY THROUGH SATURDAY BENEATH THE HIGH PRESSURE RIDGE.
-GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...
LONG TERM...BADGETT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1252 AM EDT TUE SEP 24 2013
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE SITTING OVER THE REGION WILL GRADUALLY
WEAKEN TODAY AND TONIGHT. A LOW PRESSURE SYSTEM WILL CROSS THE
SOUTHEAST STATES WEDNESDAY AND WEDNESDAY NIGHT... AS AN UPPER LEVEL
TROUGH TRACKS ACROSS THE CAROLINAS. HIGH PRESSURE WILL BUILD BACK
INTO THE REGION THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM MONDAY...
LAYER OF STRATOCU THAT WAS FAIRLY PREVALENT ACROSS CENTRAL NC THIS
AFTERNOON DISSIPATED WITH THE LOSS OF HEATING. AN AREA OF HIGH
PRESSURE AT THE SURFACE AND ALOFT WILL PERSIST ACROSS THE FORECAST
AREA OVERNIGHT INTO TUESDAY MORNING. THIS WEATHER PATTERN USUALLY
SIGNALS A SEASONABLY COOL AND DRY FORECAST. THIS SEEMS PLAUSIBLE AS
SFC DEWPOINTS THIS AFTERNOON WERE IN THE UPPER 40S TO LOWER 50S.
EXPECT COMPARABLE MIN TEMPS TONIGHT WITH MID 40S POSSIBLE IN THE
NORMALLY COLDER LOCATIONS (SUCH AS NEW HILL...LOUISBURG...
HENDERSON...ETC.) EXCEPTION TO THIS MAY BE THE FAR WESTERN PIEDMONT
WHERE MODEL GUIDANCE CONTINUES TO SUGGEST A SHALLOW LAYER OF
MOISTURE CENTERED JUST BELOW 850MB. 00Z GSO SOUNDING DEPICTS 2 DEG C
DEWPOINT SPREAD AT THAT LEVEL. THIS MOIST LAYER COUPLED WITH LIFT
GENERATED BY WEAK LOW LEVEL WAA WHICH MAY RESULT IN A LAYER OF
STRATUS OVERNIGHT. IF CLOUDS DO DEVELOP...THIS WILL ACT AS A BLANKET
AND REDUCE THE HEAT LOSS AT THE SURFACE RESULTING IN WARMER TEMPS.
INHERITED A FORECAST OF MID 50S ALONG YADKIN RIVER VALLEY/NW
PIEDMONT. DUE TO LACK OF CLOUDS EARLY THIS EVENING AND WINDS NEAR
CALM...POTENTIAL FOR TEMPS TO COOL A BIT LOWER. ADJUSTED MIN TEMPS
TO THE LOWER 50S IN THE TRIAD REGION.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 325 PM MONDAY...
THE SHORTWAVE RIDGE PROGRESSING INTO THE REGION TONIGHT WILL
GRADUALLY WEAKEN TUE/TUE NIGHT AS THE ROBUST UPPER LEVEL LOW
(CENTERED IN WESTERN NE THIS AFTERNOON) TRACKS TO THE CENTRAL MS
RIVER VALLEY BY SUNSET TUE AND TO THE DOORSTEP OF THE SOUTHERN
APPALACHIANS BY SUNRISE WED. DESPITE HEIGHT FALLS IN ADVANCE OF THE
APPROACHING UPPER LEVEL LOW LATE TUE INTO TUE NIGHT...WEAKENING
SURFACE HIGH PRESSURE WILL REMAIN ANCHORED IN PLACE ACROSS THE
MID-ATLANTIC STATES ON THE WESTERN (SUBSIDENT) SIDE OF A STALLED
UPPER LEVEL LOW OVER THE CANADIAN MARITIMES. WITH A DRY AND
SUBSIDENT COLUMN PERSISTING OVER CENTRAL NC...EXPECT MOSTLY SUNNY
SKIES (ASIDE FROM SCATTERED DIURNAL CU WITH BASES 3500-4500 FT AGL)
TO PREVAIL THROUGH TUE EVENING. TOP-DOWN MOISTENING /INCREASING
CIRRUS/ CAN BE EXPECTED TUE NIGHT AS THE UPPER LEVEL LOW APPROACHES
THE MOUNTAINS FROM THE WEST...THOUGH DRY CONDITIONS WILL PREVAIL
GIVEN THAT THE BEST UPPER LEVEL FORCING WILL REMAIN UPSTREAM OVER
THE TN VALLEY AND A DRY LOW-LEVEL AIRMASS /LITTLE OR NO WAA/ WILL
PERSIST OVER CENTRAL NC. EXPECT HIGHS SIMILAR TO ALBEIT SLIGHTLY
WARMER THAN TODAY...IN THE MID 70S...WITH LOWS TUE NIGHT RANGING
FROM THE MID 50S (WEST) TO UPPER 40S EAST...ONCE AGAIN DEPENDENT
PRIMARILY UPON CLOUD COVER. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 245 PM MONDAY...
CONFIDENCE IN AN UNSETTLED PATTERN FOR WEDNESDAY INTO A PORTION OF
THURSDAY HAS INCREASED A BIT TODAY. MOST MODELS ARE INDICATING A
MID/UPPER TROUGH AMPLIFICATION OVER THE EASTERN STATES... SHIFTING
OFFSHORE LATE WEEK. THE IMPORTANT SURFACE WAVE IS STILL SUPPORTED TO
DEVELOP/TRACK WELL TO OUR SOUTH AND EAST... FROM THE GULF COAST 12Z
WEDNESDAY... EAST ACROSS NORTHERN FLORIDA EARLY THURSDAY... THEN OFF
THE SOUTH ATLANTIC COAST FRIDAY. THE EC CONTINUES TO BE THE FAVORED
MODEL OF CHOICE CONCERNING OPERATIONAL RUNS DUE TO ITS CONSISTENCY
WITH THE EVOLUTION OF THE SYSTEM IN RECENT DAYS THROUGH TODAY. MOST
OF THE HEAVY RAIN WITH THIS SYSTEM SHOULD BE CONFINED TO THE DEEP
SOUTH AND POSSIBLY INTO SC AS THE MAIN LOW LEVEL BOUNDARY WILL BE
HUNG UP THERE. HOWEVER... THERE IS STILL A GOOD CHANCE OF RAIN WITH
THE MID/UPPER SUPPORT ALONG WITH ISENTROPIC LIFT WED-WED NIGHT.
AFTER THE LOW MOVES OFFSHORE... ANOTHER MID/UPPER LOW MAY AGAIN
TARGET THE GREAT LAKES AND MIDWEST SUPPORTED BY TELECONNECTIONS WITH
THE NE PAC UPPER TROUGH... AND DOWNSTREAM UPPER RIDGE DEVELOPMENT
OVER THE ROCKIES. THIS MAY LEAD TO MORE IN THE WAY OF UNSETTLED
CONDITIONS LATER SUNDAY INTO EARLY NEXT WEEK.
SENSIBLE WEATHER FOR CENTRAL NC SHOULD CONSIST OF THE HIGHEST
CHANCES OF RAIN ON WEDNESDAY INTO WEDNESDAY NIGHT... ASSOCIATED WITH
THE MID/UPPER TROUGH. THEN THE HIGHEST POP IN THE EAST ON THURSDAY
(MAINLY MORNING) WITH THE SURFACE WAVE TRACKING TO OUR SOUTH AND
EAST AND OFFSHORE THEN. IT IS STILL TOO EARLY TO FORECAST A FULL
BLOWN COLD AIR DAMMING EVENT THAT WOULD BE OF IN-SITU OR POSSIBLY
HYBRID NATURE WED INTO THU... GIVEN THE LACK OF A SUPPORTING PARENT
SURFACE HIGH THAT WOULD BE STRONG ENOUGH... AND IN THE PREFERRED
LOCATION FOR ANYTHING MORE IN OUR REGION. THE DEVELOPMENT OF AN
IN-SITU OR WEAK HYBRID CAD EVENT SHOULD BE HIGHLY DEPENDENT BY THE
QPF ON WED... WHICH IS STILL VERY MUCH IN QUESTION... AND IS STILL
EXPECTED TO BE LESS THAN 0.25 OF AN INCH IN THE DAMMING REGION. DUE
TO THE LACK OF CONFIDENCE ON ANYTHING MORE THAN 0.25 OF AN INCH OF
RAIN WED-WED NIGHT AT THE CURRENT TIME... WE WILL MAINTAIN POP IN
THE CHANCE TO HIGH CHANCE CATEGORY... QPF OF LESS THAN 0.25 OF AN
INCH... AND TEMPERATURES (WHILE COOLER THAN NORMAL)... NOT BY MUCH
(2-5 DEGREES OR SO FOR DAYTIME HIGHS).
GIVEN THE EXPECTATION OF A WEAK CAD AT BEST... SKIES SHOULD CLEAR
MORE QUICKLY LATE THU AND FRI AS THE STORM SHIFTS WELL OFFSHORE.
LOWS WILL COOL INTO THE LOWER TO MID 50S FRI... WITH HIGHS IN THE
MID 70S WITH MOSTLY SUNNY SKIES FRI. SAT-SUN... SKIES SHOULD
CONTINUE MOSTLY CLEAR/MOSTLY SUNNY AS HIGH PRESSURE IS EXPECTED TO
EXTEND DOWN THE EASTERN SEABOARD INTO SUNDAY. LOWS IN THE LOWER TO
MID 50S AND HIGHS IN THE LOWER TO MID 70S ARE EXPECTED.
SUNDAY NIGHT AND MONDAY... EXPECT SOME INCREASE IN CLOUDINESS FOR
NOW... POSSIBLY A CHANCE OF RAIN AGAIN - BUT UNCERTAINTY THIS FAR
OUT SUPPORTS A SLIGHT CHANCE OF SHOWERS IN THE FORECAST MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 1250 AM TUESDAY...
REST OF TONIGHT: VFR STRATUS CONTINUES TO EXPAND IN AREA OVER
CENTRAL VA INTO WRN NC... AND BASED ON THIS TREND APPEARS POISED TO
SPREAD INTO INT/GSO AND PERHAPS RDU AS WELL OVERNIGHT. PATCHY VFR
CLOUDS AFFECTED FAY EARLIER AND ADDITIONAL CLOUDS REMAIN POSSIBLE
THROUGH DAYBREAK. MEANWHILE... BANKS OF SHALLOW DENSE FOG HAVE
FORMED NEAR RWI -- PROMPTED BY THE NEARBY RIVER -- AND THIS FOG
SHOULD PERSIST OVERNIGHT... WITH VSBYS MOSTLY IFR BUT VARYING
BETWEEN LIFR AND MVFR THROUGH DAYBREAK. HRRR MODEL DEPICTS LOW IFR
STRATUS SPREADING ACROSS ALL OF CENTRAL NC OVERNIGHT... AND WHILE
THIS LOOKS OVERDONE... WE WILL KEEP A CLOSE EYE ON CLOUD TRENDS
THROUGH THE REST OF THE NIGHT.
AFTER 12Z: VFR THROUGH AT LEAST THIS EVENING. ANY MORNING STRATUS
WILL MIX OUT BY 14Z WITH THE ONSET OF HEATING... THEN ANOTHER ROUND
OF MOSTLY SCATTERED FLAT CUMULUS BASED AROUND 4000 FT AGL IS
EXPECTED THIS AFTERNOON... AS THE MID/UPPER LEVELS STAY STABLE AND
VERY DRY WHILE A THIN MOIST LAYER PERSISTS BENEATH THE SUBSIDENCE
INVERSION ALOFT. THEN AFTER SUNSET... STABILIZING LOW LEVELS (LOWEST
4000 FT) AND VERY LIGHT WINDS WITH INCREASING NEAR-SURFACE MOISTURE
WILL BRING A RISK OF MVFR FOG TONIGHT... ALTHOUGH THE BETTER CHANCE
OF ADVERSE AVIATION CONDITIONS WILL HOLD OFF UNTIL AFTER 06Z
TONIGHT. HIGH CLOUDS BASED ABOVE 15000 FT AGL WILL SPREAD IN FROM
THE WEST TONIGHT. WINDS WILL BE VARIABLE IN DIRECTION THROUGH THE
PERIOD AT SPEEDS UNDER 7 KTS.
LOOKING BEYOND 06Z EARLY WEDNESDAY MORNING: PATCHY LOW STRATUS AND
FOG ARE POSSIBLE THROUGH MID MORNING... PARTICULARLY NEAR BODIES OF
WATER WHERE SHALLOW DENSE GROUND FOG MAY FORM PRIOR TO DAYBREAK. ANY
SUCH CLOUDS SHOULD MIX OUT BEFORE 15Z WITH VFR CONDITIONS
RETURNING... ALTHOUGH WE WILL SEE AN INCREASE IN STRATOCUMULUS BASED
AROUND 3500 FT AGL ALONG WITH THICKENING AND LOWERING MID CLOUDS AS
A STORM SYSTEM APPROACHES WEDNESDAY. IN GENERAL... VFR CONDITIONS
WILL DOMINATE AS THIS SYSTEM CROSSES THE SOUTHEAST AND CAROLINAS...
WITH CLOUD BASES MOSTLY ABOVE 3500 FT WITH LIGHT SHOWERS. THIS
SYSTEM WILL EXIT ON THURSDAY WITH NEW HIGH PRESSURE RIDGING BUILDING
IN AT THE SURFACE. SHALLOW FOG IS POSSIBLE EARLY FRIDAY MORNING WITH
HIGH SURFACE RH AND LIGHT WINDS... BUT OTHERWISE EXPECT VFR
CONDITIONS FRIDAY THROUGH SATURDAY BENEATH THE HIGH PRESSURE RIDGE.
-GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...WSS
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1252 AM EDT MON SEP 23 2013
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE SITTING OVER THE REGION WILL GRADUALLY
WEAKEN TODAY AND TONIGHT. A LOW PRESSURE SYSTEM WILL CROSS THE
SOUTHEAST STATES WEDNESDAY AND WEDNESDAY NIGHT... AS AN UPPER LEVEL
TROUGH TRACKS ACROSS THE CAROLINAS. HIGH PRESSURE WILL BUILD BACK
INTO THE REGION THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM MONDAY...
LAYER OF STRATOCU THAT WAS FAIRLY PREVALENT ACROSS CENTRAL NC THIS
AFTERNOON DISSIPATED WITH THE LOSS OF HEATING. AN AREA OF HIGH
PRESSURE AT THE SURFACE AND ALOFT WILL PERSIST ACROSS THE FORECAST
AREA OVERNIGHT INTO TUESDAY MORNING. THIS WEATHER PATTERN USUALLY
SIGNALS A SEASONABLY COOL AND DRY FORECAST. THIS SEEMS PLAUSIBLE AS
SFC DEWPOINTS THIS AFTERNOON WERE IN THE UPPER 40S TO LOWER 50S.
EXPECT COMPARABLE MIN TEMPS TONIGHT WITH MID 40S POSSIBLE IN THE
NORMALLY COLDER LOCATIONS (SUCH AS NEW HILL...LOUISBURG...
HENDERSON...ETC.) EXCEPTION TO THIS MAY BE THE FAR WESTERN PIEDMONT
WHERE MODEL GUIDANCE CONTINUES TO SUGGEST A SHALLOW LAYER OF
MOISTURE CENTERED JUST BELOW 850MB. 00Z GSO SOUNDING DEPICTS 2 DEG C
DEWPOINT SPREAD AT THAT LEVEL. THIS MOIST LAYER COUPLED WITH LIFT
GENERATED BY WEAK LOW LEVEL WAA WHICH MAY RESULT IN A LAYER OF
STRATUS OVERNIGHT. IF CLOUDS DO DEVELOP...THIS WILL ACT AS A BLANKET
AND REDUCE THE HEAT LOSS AT THE SURFACE RESULTING IN WARMER TEMPS.
INHERITED A FORECAST OF MID 50S ALONG YADKIN RIVER VALLEY/NW
PIEDMONT. DUE TO LACK OF CLOUDS EARLY THIS EVENING AND WINDS NEAR
CALM...POTENTIAL FOR TEMPS TO COOL A BIT LOWER. ADJUSTED MIN TEMPS
TO THE LOWER 50S IN THE TRIAD REGION.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 325 PM MONDAY...
THE SHORTWAVE RIDGE PROGRESSING INTO THE REGION TONIGHT WILL
GRADUALLY WEAKEN TUE/TUE NIGHT AS THE ROBUST UPPER LEVEL LOW
(CENTERED IN WESTERN NE THIS AFTERNOON) TRACKS TO THE CENTRAL MS
RIVER VALLEY BY SUNSET TUE AND TO THE DOORSTEP OF THE SOUTHERN
APPALACHIANS BY SUNRISE WED. DESPITE HEIGHT FALLS IN ADVANCE OF THE
APPROACHING UPPER LEVEL LOW LATE TUE INTO TUE NIGHT...WEAKENING
SURFACE HIGH PRESSURE WILL REMAIN ANCHORED IN PLACE ACROSS THE
MID-ATLANTIC STATES ON THE WESTERN (SUBSIDENT) SIDE OF A STALLED
UPPER LEVEL LOW OVER THE CANADIAN MARITIMES. WITH A DRY AND
SUBSIDENT COLUMN PERSISTING OVER CENTRAL NC...EXPECT MOSTLY SUNNY
SKIES (ASIDE FROM SCATTERED DIURNAL CU WITH BASES 3500-4500 FT AGL)
TO PREVAIL THROUGH TUE EVENING. TOP-DOWN MOISTENING /INCREASING
CIRRUS/ CAN BE EXPECTED TUE NIGHT AS THE UPPER LEVEL LOW APPROACHES
THE MOUNTAINS FROM THE WEST...THOUGH DRY CONDITIONS WILL PREVAIL
GIVEN THAT THE BEST UPPER LEVEL FORCING WILL REMAIN UPSTREAM OVER
THE TN VALLEY AND A DRY LOW-LEVEL AIRMASS /LITTLE OR NO WAA/ WILL
PERSIST OVER CENTRAL NC. EXPECT HIGHS SIMILAR TO ALBEIT SLIGHTLY
WARMER THAN TODAY...IN THE MID 70S...WITH LOWS TUE NIGHT RANGING
FROM THE MID 50S (WEST) TO UPPER 40S EAST...ONCE AGAIN DEPENDENT
PRIMARILY UPON CLOUD COVER. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 245 PM MONDAY...
CONFIDENCE IN AN UNSETTLED PATTERN FOR WEDNESDAY INTO A PORTION OF
THURSDAY HAS INCREASED A BIT TODAY. MOST MODELS ARE INDICATING A
MID/UPPER TROUGH AMPLIFICATION OVER THE EASTERN STATES... SHIFTING
OFFSHORE LATE WEEK. THE IMPORTANT SURFACE WAVE IS STILL SUPPORTED TO
DEVELOP/TRACK WELL TO OUR SOUTH AND EAST... FROM THE GULF COAST 12Z
WEDNESDAY... EAST ACROSS NORTHERN FLORIDA EARLY THURSDAY... THEN OFF
THE SOUTH ATLANTIC COAST FRIDAY. THE EC CONTINUES TO BE THE FAVORED
MODEL OF CHOICE CONCERNING OPERATIONAL RUNS DUE TO ITS CONSISTENCY
WITH THE EVOLUTION OF THE SYSTEM IN RECENT DAYS THROUGH TODAY. MOST
OF THE HEAVY RAIN WITH THIS SYSTEM SHOULD BE CONFINED TO THE DEEP
SOUTH AND POSSIBLY INTO SC AS THE MAIN LOW LEVEL BOUNDARY WILL BE
HUNG UP THERE. HOWEVER... THERE IS STILL A GOOD CHANCE OF RAIN WITH
THE MID/UPPER SUPPORT ALONG WITH ISENTROPIC LIFT WED-WED NIGHT.
AFTER THE LOW MOVES OFFSHORE... ANOTHER MID/UPPER LOW MAY AGAIN
TARGET THE GREAT LAKES AND MIDWEST SUPPORTED BY TELECONNECTIONS WITH
THE NE PAC UPPER TROUGH... AND DOWNSTREAM UPPER RIDGE DEVELOPMENT
OVER THE ROCKIES. THIS MAY LEAD TO MORE IN THE WAY OF UNSETTLED
CONDITIONS LATER SUNDAY INTO EARLY NEXT WEEK.
SENSIBLE WEATHER FOR CENTRAL NC SHOULD CONSIST OF THE HIGHEST
CHANCES OF RAIN ON WEDNESDAY INTO WEDNESDAY NIGHT... ASSOCIATED WITH
THE MID/UPPER TROUGH. THEN THE HIGHEST POP IN THE EAST ON THURSDAY
(MAINLY MORNING) WITH THE SURFACE WAVE TRACKING TO OUR SOUTH AND
EAST AND OFFSHORE THEN. IT IS STILL TOO EARLY TO FORECAST A FULL
BLOWN COLD AIR DAMMING EVENT THAT WOULD BE OF IN-SITU OR POSSIBLY
HYBRID NATURE WED INTO THU... GIVEN THE LACK OF A SUPPORTING PARENT
SURFACE HIGH THAT WOULD BE STRONG ENOUGH... AND IN THE PREFERRED
LOCATION FOR ANYTHING MORE IN OUR REGION. THE DEVELOPMENT OF AN
IN-SITU OR WEAK HYBRID CAD EVENT SHOULD BE HIGHLY DEPENDENT BY THE
QPF ON WED... WHICH IS STILL VERY MUCH IN QUESTION... AND IS STILL
EXPECTED TO BE LESS THAN 0.25 OF AN INCH IN THE DAMMING REGION. DUE
TO THE LACK OF CONFIDENCE ON ANYTHING MORE THAN 0.25 OF AN INCH OF
RAIN WED-WED NIGHT AT THE CURRENT TIME... WE WILL MAINTAIN POP IN
THE CHANCE TO HIGH CHANCE CATEGORY... QPF OF LESS THAN 0.25 OF AN
INCH... AND TEMPERATURES (WHILE COOLER THAN NORMAL)... NOT BY MUCH
(2-5 DEGREES OR SO FOR DAYTIME HIGHS).
GIVEN THE EXPECTATION OF A WEAK CAD AT BEST... SKIES SHOULD CLEAR
MORE QUICKLY LATE THU AND FRI AS THE STORM SHIFTS WELL OFFSHORE.
LOWS WILL COOL INTO THE LOWER TO MID 50S FRI... WITH HIGHS IN THE
MID 70S WITH MOSTLY SUNNY SKIES FRI. SAT-SUN... SKIES SHOULD
CONTINUE MOSTLY CLEAR/MOSTLY SUNNY AS HIGH PRESSURE IS EXPECTED TO
EXTEND DOWN THE EASTERN SEABOARD INTO SUNDAY. LOWS IN THE LOWER TO
MID 50S AND HIGHS IN THE LOWER TO MID 70S ARE EXPECTED.
SUNDAY NIGHT AND MONDAY... EXPECT SOME INCREASE IN CLOUDINESS FOR
NOW... POSSIBLY A CHANCE OF RAIN AGAIN - BUT UNCERTAINTY THIS FAR
OUT SUPPORTS A SLIGHT CHANCE OF SHOWERS IN THE FORECAST MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 1250 AM TUESDAY...
REST OF TONIGHT: VFR STRATUS CONTINUES TO EXPAND IN AREA OVER
CENTRAL VA INTO WRN NC... AND BASED ON THIS TREND APPEARS POISED TO
SPREAD INTO INT/GSO AND PERHAPS RDU AS WELL OVERNIGHT. PATCHY VFR
CLOUDS AFFECTED FAY EARLIER AND ADDITIONAL CLOUDS REMAIN POSSIBLE
THROUGH DAYBREAK. MEANWHILE... BANKS OF SHALLOW DENSE FOG HAVE
FORMED NEAR RWI -- PROMPTED BY THE NEARBY RIVER -- AND THIS FOG
SHOULD PERSIST OVERNIGHT... WITH VSBYS MOSTLY IFR BUT VARYING
BETWEEN LIFR AND MVFR THROUGH DAYBREAK. HRRR MODEL DEPICTS LOW IFR
STRATUS SPREADING ACROSS ALL OF CENTRAL NC OVERNIGHT... AND WHILE
THIS LOOKS OVERDONE... WE WILL KEEP A CLOSE EYE ON CLOUD TRENDS
THROUGH THE REST OF THE NIGHT.
AFTER 12Z: VFR THROUGH AT LEAST THIS EVENING. ANY MORNING STRATUS
WILL MIX OUT BY 14Z WITH THE ONSET OF HEATING... THEN ANOTHER ROUND
OF MOSTLY SCATTERED FLAT CUMULUS BASED AROUND 4000 FT AGL IS
EXPECTED THIS AFTERNOON... AS THE MID/UPPER LEVELS STAY STABLE AND
VERY DRY WHILE A THIN MOIST LAYER PERSISTS BENEATH THE SUBSIDENCE
INVERSION ALOFT. THEN AFTER SUNSET... STABILIZING LOW LEVELS (LOWEST
4000 FT) AND VERY LIGHT WINDS WITH INCREASING NEAR-SURFACE MOISTURE
WILL BRING A RISK OF MVFR FOG TONIGHT... ALTHOUGH THE BETTER CHANCE
OF ADVERSE AVIATION CONDITIONS WILL HOLD OFF UNTIL AFTER 06Z
TONIGHT. HIGH CLOUDS BASED ABOVE 15000 FT AGL WILL SPREAD IN FROM
THE WEST TONIGHT. WINDS WILL BE VARIABLE IN DIRECTION THROUGH THE
PERIOD AT SPEEDS UNDER 7 KTS.
LOOKING BEYOND 06Z EARLY WEDNESDAY MORNING: PATCHY LOW STRATUS AND
FOG ARE POSSIBLE THROUGH MID MORNING... PARTICULARLY NEAR BODIES OF
WATER WHERE SHALLOW DENSE GROUND FOG MAY FORM PRIOR TO DAYBREAK. ANY
SUCH CLOUDS SHOULD MIX OUT BEFORE 15Z WITH VFR CONDITIONS
RETURNING... ALTHOUGH WE WILL SEE AN INCREASE IN STRATOCUMULUS BASED
AROUND 3500 FT AGL ALONG WITH THICKENING AND LOWERING MID CLOUDS AS
A STORM SYSTEM APPROACHES WEDNESDAY. IN GENERAL... VFR CONDITIONS
WILL DOMINATE AS THIS SYSTEM CROSSES THE SOUTHEAST AND CAROLINAS...
WITH CLOUD BASES MOSTLY ABOVE 3500 FT WITH LIGHT SHOWERS. THIS
SYSTEM WILL EXIT ON THURSDAY WITH NEW HIGH PRESSURE RIDGING BUILDING
IN AT THE SURFACE. SHALLOW FOG IS POSSIBLE EARLY FRIDAY MORNING WITH
HIGH SURFACE RH AND LIGHT WINDS... BUT OTHERWISE EXPECT VFR
CONDITIONS FRIDAY THROUGH SATURDAY BENEATH THE HIGH PRESSURE RIDGE.
-GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...WSS
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
307 AM CDT TUE SEP 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CDT TUE SEP 24 2013
LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH WORKING ITS
WAY FROM CENTRAL NORTH DAKOTA INTO EASTERN NORTH DAKOTA. LOCAL
RADAR AHEAD OF THIS TROUGH CONTINUES TO SHOW SCATTERED LIGHT
SHOWERS FROM NEAR JAMESTOWN SOUTH TO ASHLEY AND EAST TO OAKES.
THIS AREA WILL WANE THROUGH 12Z AS THE UPPER TROUGH EXITS THE
COUNTY WARNING AREA. THE FOG/STRATUS LOOP INDICATES AN AREA OF
FOG/LOW CLOUDS IN ADAMS AND HETTINGER COUNTIES. THE HRRR CLOUD
CEILING HEIGHT IS ADVERTISING THIS AREA TO EXPAND SLIGHTLY AND
SLIDE SOUTHEAST...BARELY CLIPPING BISMARCK THROUGH 15Z. HAVE
FOLLOWED IT FOR THE SKY/WEATHER TRENDS EARLY THIS MORNING. OTHERWISE
WARM AIR ADVECTION COMMENCES TODAY THROUGH TONIGHT. LARGE SCALE
CONVERGENCE ALOFT WILL ALLOW FOR PLENTY OF SUNSHINE TODAY. WITH
WARM AIR ADVECTION INCREASING TUESDAY NIGHT...A CHANGE TOWARD
DIVERGENCE ALOFT ENSUES...ESPECIALLY OVER THE WEST/NORTHWEST. THE
FAR NORTHWEST IS SUSCEPTIBLE TO AN ISOLATED SHOWER/THUNDERSTORM IN
AFTER MIDNIGHT...OTHERWISE DRY WEATHER PREVAILS ELSEWHERE THROUGH
THE SHORT TERM PERIOD. H85 TEMPS BETWEEN +12C TO +16C WILL YIELD
AFTERNOON HIGHS IN THE UPPER 60S NORTH TO LOWER 70S SOUTH AND
WEST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 307 AM CDT TUE SEP 24 2013
THE MAIN FORECAST ISSUES IN THE LONG TERM WILL BE ASSOCIATED WITH
A STRONG UPPER LEVEL TROUGH THAT TAKES SHAPE OVER THE NORTHWEST
U.S. OVER THE NEXT 24 HOURS...AND TRACKS INTO THE NORTHERN HIGH
PLAINS BY THE END OF THE WORK WEEK. CURRENTLY...UPPER LEVEL
CIRCULATION CAN BE SEEN OFF THE BRITISH COLUMBIA COAST WITH A
STRONG SHORTWAVE TROUGH OVER THE EASTERN PACIFIC...OFF THE
NORTHERN CALIFORNIA COAST AND MATCHES WITH DETERMINISTIC MODELS.
THE STRONG SHORTWAVE TROUGH WILL BE THE FIRST TO INFLUENCE OUR
WEATHER AS IT MOVES ACROSS THE NORTHERN ROCKIES. STRONG SURFACE LOW
PRESSURE DEVELOPS OVER EASTERN MONTANA BY TUESDAY NIGHT WITH
INCREASING SOUTHERLY WINDS OVER WESTERN AND CENTRAL NORTH DAKOTA.
THIS WILL BRING A SMALL CHANCE OF THUNDERSTORMS TO THE FAR WEST AND
NORTHWEST DURING THE DAY ON WEDNESDAY. THUNDERSTORM CHANCES WILL
INCREASE WEDNESDAY NIGHT INTO THURSDAY AS THE SURFACE LOW SLOWS DOWN
AND TRACKS FROM WESTERN INTO CENTRAL NORTH DAKOTA DUE TO A STRONG
UPPER LEVEL JET ROUNDING THE BASE OF THE MAIN UPPER LEVEL LOW AS
IT MOVES INTO THE NORTHERN ROCKIES. INCREASING UPPER LEVEL JET
DYNAMICS ACROSS THE NORTHERN HIGH PLAINS COULD SUPPORT SCATTERED
SEVERE STORMS THAT WOULD THEN TRACK INTO THE WESTERN DAKOTAS.
THUNDERSTORMS ARE EXPECTED TO BECOME ELEVATED LATE WEDNESDAY NIGHT
INTO THURSDAY MORNING WITH A STRONG LOW LEVEL JET LIFTING INTO
CENTRAL NORTH DAKOTA. THE GREATEST THREAT FOR THUNDERSTORMS WILL
BE ACROSS FAR WESTERN AND NORTH CENTRAL NORTH DAKOTA WEDNESDAY
NIGHT THROUGH THURSDAY MORNING...ALTHOUGH WITH SUCH STRONG
DYNAMICS...SCATTERED THUNDERSTORMS CANNOT BE RULED OUT OVER
CENTRAL NORTH DAKOTA.
DETERMINISTIC MODELS ARE ALL DEPICTING A BREAK IN THE ACTION BEHIND
THE INITIAL STRONG SHORTWAVE THURSDAY AFTERNOON INTO THURSDAY
EVENING...BEFORE THE MAIN UPPER LEVEL LOW LIFTS INTO THE NORTHERN
PLAINS. PRECIPITATION CHANCES THEN INCREASE LATE THURSDAY NIGHT
THROUGH FRIDAY AS THE UPPER LEVEL TROUGH MOVES INTO THE NORTHERN
PLAINS. THERE ARE SOME DIFFERENCES IN QPF BETWEEN THE WETTER ECMWF
AND DRIER GFS/GEM ON FRIDAY. BY THIS TIME THE LOW LEVEL FLOW HAS
SHIFTED NORTH OVER ALL BUT THE FAR SOUTHEAST CWA AND PRECIPITATION
IS EXPECTED TO BE SHOWERS WITH PERHAPS AN ISOLATED THUNDERSTORM.
THUNDERSTORM CHANCES WILL REMAIN OVER THE FAR SOUTHEAST FRIDAY
NIGHT BEHIND THE SURFACE BOUNDARY AND JUST AHEAD OF THE UPPER
LEVEL TROUGH.
UPPER LEVEL RIDGING THEN BUILDS OVER THE REGION BRINGING DRY
CONDITIONS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
TEMPERATURES MAINLY IN THE 70S AHEAD OF THE MAIN COLD FRONT
WEDNESDAY WILL COOL INTO THE 50S AND 60S ACROSS THE AREA BY FRIDAY.
THEN A WARM-UP BACK INTO THE 70S IS EXPECTED BY SUNDAY AND MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1230 AM CDT TUE SEP 24 2013
VCFG WAS ADDED TO KMOT/KBIS AND KJMS THROUGH 15Z TUESDAY. WILL
CONTINUE TO MONITOR BUT INDICATIONS ARE THAT LOW CLOUDS/FOG SHOULD
REMAIN JUST SOUTH OF KBIS/KJMS AND NORTH OF KMOT. WILL CONTINUE TO
MONITOR THE TRENDS AND ADJUST IF NECESSARY. OTHERWISE VFR CIGS/VSBYS
ARE EXPECTED THROUGH THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM...TWH
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1230 AM CDT TUE SEP 24 2013
.UPDATE...
ISSUED AT 1230 AM CDT TUE SEP 24 2013
LATEST FOG/STRATUS IMAGERY ALONG WITH THE HRRR CLOUD HEIGHT
FORECAST FOR THE REST OF THE NIGHT SHOWS AN AREA OF FOG/LOW CLOUDS
DEVELOPING OVER FAR WESTERN SOUTH DAKOTA AND INTO ADAMS COUNTY
NEAR HETTINGER. HAVE INCREASED CLOUDS AND ADDED IN A MENTION OF
FOG THROUGH 15Z FOR PORTIONS OF SOUTH CENTRAL...WHERE THE RAIN HAD
FALLEN EARLIER...AND ALSO OVER THE NORTH CENTRAL. ALSO DELAYED THE
ENDING OF THE SHOWERS IN THE JAMES RIVER VALLEY AS LIGHT SHOWERS CONTINUE
TO PERSIST. EXTENDED SHOWER CHANCES THROUGH 11Z TUESDAY BEFORE
ENDING THE MENTION OF PRECIPITATION.
UPDATE ISSUED AT 902 PM CDT MON SEP 23 2013
AT 9 PM CDT...BAND OF SHOWERS ACROSS CENTRAL NORTH DAKOTA
CONTINUED TO GRADUALLY SHRINK. FOR THIS FORECAST UPDATE...REFINED
THE SHOWER AREA. SHOWERS WILL PERSIST UNTIL MIDNIGHT CDT CENTRAL
SECTIONS...SHRINKING SLOWLY. CLEARING SKIES ARE ENTERING THE WEST
AT THIS TIME. TEMPERATURES AND WINDS LOOK GOOD SO FAR.
UPDATE ISSUED AT 635 PM CDT MON SEP 23 2013
RAIN BAND TENDING TO BE AROUND 75 MILES WIDE ACROSS CENTRAL NORTH
DAKOTA. THIS BAND IS TRANSLATING EAST AT THE SAME TIME IT IS
DIMINISHING SLOWLY IN COVERAGE AND INTENSITY. DO NOT BELIEVE A
SIGNIFICANT AMOUNT OF RAIN WILL REACH THE JAMES RIVER VALLEY
TONIGHT BUT A CHANCE DOES REMAIN FOR SOME LIGHT RAIN THERE. SEE
THE RAIN ENDING ACROSS THE CENTRAL BY 10 PM CDT. TRIED TO REFINE
THE RAIN REGION IN THE LIKELY CATEGORY CENTRAL THROUGH THE MID
EVENING, THEN QUICKLY DRY THE PRECIP AREA BY MIDNIGHT. OTHERWISE
WILL SEE GRADUAL CLEARING. ENOUGH NORTHWEST FLOW BEHIND THE FRONT
TO KEEP MIXING UP AND HAVE NOT CONSIDERED FOG LATER
TONIGHT...ALTHOUGH WILL CONTINUE TO MONITOR.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 310 PM CDT MON SEP 23 2013
THE MAIN FORECAST CHALLENGE WILL BE THE TIMING OF A BAND OF RAIN
SHOWERS MOVING EAST ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS
AFTERNOON AND EVENING.
THE LATEST SHORT RANGE MODEL GUIDANCE CONTINUES TO SLOW THE
PROGRESSION OF THIS SYSTEM ACROSS THE REGION THIS AFTERNOON AND
EVENING. RADAR TRENDS HAVE BEEN SUPPORTING THE LATEST MODEL PROGS SO
ADJUSTED THE FORECAST ACCORDINGLY. FURTHERMORE...THE PRIMARY UPPER
LEVEL LOW DRIVING THIS SYSTEM IS BEGINNING TO RACE AHEAD OF THIS
BAND OF PRECIP...CUTTING OFF MUCH OF THE UPPER LEVEL SUPPORT. GIVEN
THE SLOWER PROGRESSION AND SYNOPTIC EVOLUTION OF THE UPPER
LOW...DECIDED TO LOWER POPS BY A CATEGORY OVER CENTRAL NORTH DAKOTA
AS PRECIP INTENSITY AND COVERAGE IS NOW EXPECTED TO DECREASE AS THE
AFTERNOON AND EVENING PROGRESSES.
THE SURFACE TROUGH PROVIDING FOCUS FOR THIS PRECIPITATION SHOULD BE
IN EASTERN NORTH DAKOTA AFTER MIDNIGHT TONIGHT. DRIER AIR IS PROGGED
TO FILTER INTO WESTERN NORTH DAKOTA AFTER MIDNIGHT...WITH
RADIATIONAL COOLING CONDITIONS DEVELOPING. THE RELATIVE LOW-LYING
AREAS WEST COULD SEE LOWS IN THE UPPER 30S BY EARLY TUESDAY MORNING.
DRY CONDITIONS AND SLIGHTLY ABOVE NORMAL TEMPERATURES (HIGHS IN THE
LOW 70S) ARE FORECAST TUESDAY AS HIGH PRESSURE BUILDS INTO THE REGION.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 310 PM CDT MON SEP 23 2013
THE HIGHLIGHT OF THE EXTENDED PERIOD IS THE POSSIBLE RAIN AND WIND WEDNESDAY
THROUGH FRIDAY.
AN UPPER LEVEL LONGWAVE TROUGH...CURRENTLY ENTERING THE PACIFIC
NORTHWEST...SHOULD PUSH EAST INTO WESTERN MONTANA BY WEDNESDAY.
AHEAD OF THE TROUGH...QUASI ZONAL FLOW WILL TRANSITION TO SOUTHWEST
FLOW. THIS WILL IN TURN PROMOTE SURFACE LEE CYCLOGENESIS ACROSS THE
EASTERN ROCKY MOUNTAIN RANGE IN WYOMING AND MONTANA. THIS LEE
CYCLOGENESIS IS PROGGED TO DEVELOP INTO A LARGE INVERTED TROUGH
CENTERED ACROSS NORTH DAKOTA AND ENCOMPASS MOST OF THE NORTHERN
PLAINS.
AS A RESULT OF THIS INVERTED TROUGH A STEEP PRESSURE
GRADIENT IS PROGGED TO SETUP ACROSS THE DAKOTAS LATE WEDNESDAY INTO
THURSDAY. WARM AIR ADVECTION SHOULD FURTHER ENHANCE THE MAGNITUDE
OF PRESSURE DIFFERENCES FROM MONTANA TO MINNESOTA. THEREFORE WINDY
CONDITIONS...30 MPH GUSTS...ARE POSSIBLE ACROSS MOST OF THE NORTHERN
PLAINS WEDNESDAY THROUGH FRIDAY.
ADDITIONALLY...STRONG LOW LEVEL WARM MOIST AIR RETURN AHEAD OF THE
TROUGH SHOULD PROVIDE AMPLE MOISTURE RETURN TO FUEL WIDESPREAD
SHOWERS AND THUNDERSTORMS ALONG THE WESTERN PERIPHERY OF THE INVERTED
TROUGH. THE 12 UTC GFS AND ECMWF HAVE THE LONGWAVE TROUGH AND
ASSOCIATED 100+ KNOT JET IN A FAVORABLE RAIN PRODUCING POSITION WEST OF
NORTH DAKOTA THROUGH LATE FRIDAY. THEREFORE SCATTERED TO WIDESPREAD
PRECIP IS POSSIBLE STARTING WEDNESDAY NIGHT AND LASTING THROUGH
FRIDAY NIGHT. THE MOST LIKELY AREA FOR PROLONGED PRECIPITATION
APPEARS TO BE ON ACROSS NORTHWESTERN AND NORTH CENTRAL NORTH DAKOTA.
THIS IS THE AREA WHERE THE 12 UTC GFS/ECMWF/NAM HAVE THE BEST UPPER
LEVEL JET DYNAMICS INTERACTING WITH STRONG ISENTROPIC AND ISALLOBARIC
FORCING. SOME LOCATIONS ACROSS NORTHWEST AND NORTH CENTRAL NORTH
DAKOTA COULD SEE LOCALLY HEAVY RAINFALL WEDNESDAY NIGHT THROUGH
FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1230 AM CDT TUE SEP 24 2013
VCFG WAS ADDED TO KMOT/KBIS AND KJMS THROUGH 15Z TUESDAY. WILL
CONTINUE TO MONITOR BUT INDICATIONS ARE THAT LOW CLOUDS/FOG SHOULD
REMAIN JUST SOUTH OF KBIS/KJMS AND NORTH OF KMOT. WILL CONTINUE TO
MONITOR THE TRENDS AND ADJUST IF NECESSARY. OTHERWISE VFR CIGS/VSBYS
ARE EXPECTED THROUGH THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...TM
LONG TERM...AJ
AVIATION...KS
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1142 PM CDT MON SEP 23 2013
.DISCUSSION...
SEE 06Z AVIATION DISCUSSION.
&&
.AVIATION...
CIGS HAVE SCATTERED OUT THIS EVENING AND GENERALLY VFR CONDS
PREVAIL AREAWIDE. SOME SHOWERS OVER THE GULF ARE ROTATING INTO SE
TX FROM THE EAST. SHORT TERM MODELS CONTINUE TO SHOW SOME SHOWERS
MOVING TOWARD THE COASTAL TAF SITES THROUGH THE MORNING SO ADDED A
VCSH FOR KGLS. THE RAP CONTINUES TO SHOW AN EXPANDING AREA OF
PRECIP NEAR THE COAST BETWEEN 13-16Z AND THIS SOLN GETS SOME WEAK
SUPPORT FROM THE TEXAS TECH 3 KM WRF. THE HRRR AND HI RES NMM DO
NOT SHOW THIS AREA OF PRECIP. VFR CONDS EXPECTED ON TUESDAY AFTN
WITH CLEAR SKIES DEVELOPING AREA WIDE BY 00Z WEDNESDAY. 43
&&
.PREV DISCUSSION... /ISSUED 936 PM CDT MON SEP 23 2013/
UPDATE...
SEE DISCUSSION FOR EVENING UPDATE.
DISCUSSION...
PARTLY CLOUDY SKIES ACROSS SOUTHEAST TEXAS THIS EVENING. CLOUDS
HAVE STARTED TO BREAK BUT COOLING WILL BE LIMITED TONIGHT AS
MOISTURE HAS STARTED TO WORK ITS WAY BACK INTO SOUTHEAST TEXAS.
DEEP MOISTURE HAS REMAINED OFF THE COAST THOUGH WHICH THE GFS HAS
DONE A PRETTY GOOD JOB FORECASTING. CURRENT PWATS ARE AROUND 2"
AT KGLS WHILE AROUND 1.7" IN THE CITY OF HOUSTON. ANOTHER FRONT
WILL WORK ITS WAY INTO THE AREA TUESDAY WHICH WILL MOST LIKELY BE
A DRY FRONTAL PASSAGE. BETTER MOISTURE LAYS OFF TO THE NORTHEAST
SO OUR FAR NORTHEASTERN COUNTIES MIGHT SEE SOME PRECIPITATION.
BEHIND THE FRONT MUCH DRIER AIR WILL BE USHERED IN. PWAT VALUES
FALL BELOW AN INCH AT KCLL BY 0Z WEDNESDAY IN BOTH GFS AND NAM
SOUNDINGS. DUE TO THIS DRIER AIR AND A RELATIVELY WARM START TO
THE DAY TOMORROW HIGH TEMPERATURES WILL LIKELY CLIMB INTO THE
LOWER TO MID 90S. CURRENT FORECAST HAS THIS COVERED ONLY MADE
MINOR TWEAKS TO GRIDS. 23
&&
PREV DISCUSSION... /ISSUED 319 PM CDT MON SEP 23 2013/
DISCUSSION...
SFC ANALYSIS HAS LOW PRESSURE A COUPLE HUNDRED MILES OFF THE
COAST SOUTH OF GALVESTON IN THE NW GULF. CONVECTION HAS BEEN A BIT
MORE ORGANIZED AROUND AN ELONGATED CIRCULATION SEEN ON VIS
SATELLITE IMAGERY. WATER VAPOR IMAGERY CONTINUES TO SHOW QUITE A
BIT OF DRY AIR AROUND THE SYSTEM SO DO NOT SEE THERE BEING ANY
TROPICAL DEVELOPMENT AT ALL WITH THIS SYSTEM. UPPER AIR ANALYSIS
HAS UPPER LOW OVER THE ROCKIES WHICH HAS NOW PULLED INTO THE
PLAINS PER WATER VAPOR IMAGERY. SUSPECT THIS ALONG WITH
CYCLOGENESIS IN THE PLAINS WILL HELP TO TRY AND DRAW THE GULF
CIRCULATION TOWARDS THE COAST TONIGHT INTO TOMORROW. FORECAST WILL
KEEP SOME SMALL RAIN CHANCES ALONG THE COAST OVERNIGHT INTO TUE
BUT REALLY NOT EXPECTED MUCH PRECIP FOR INLAND AREAS.
UPPER LOW IN PLAINS SHOULD SHEAR OUT AND WEAKEN WITH THE NEGATIVE
TILT TOMORROW INTO WED. THIS DOES ALLOW FOR A PACIFIC FRONT TO
PUSH INTO THE AREA TOMORROW AND TUE NIGHT. THE MAIN EFFECT WILL BE
TO PROVIDE SOME DRIER AIR FOR THE AREA SO LOOKS LIKE MAYBE A
COUPLE MORE COOL MORNINGS BEFORE MOISTURE RETURN FLOW OFF THE GULF
STARTS IN EARNEST BY THE END OF THE WEEK.
UPPER LEVEL RIDGE SHOULD DEVELOP OVER THE AREA MID WEEK WITH A
BROAD TROUGH DEVELOPING OVER THE GREAT BASIN AND ROCKIES. THE
ECMWF/GFS/CANADIAN ARE IN A LITTLE MORE AGREEMENT WITH THIS
TROUGHS EVOLUTION AND THIS WILL BE KEY WITH REGARDS TO THIS
WEEKEND`S POTENTIAL COLD FRONT. UPPER TROUGH HAS ONE PIECE OF
VORTICITY THAT MOVES INTO THE N PLAINS ON THUR WITH THE MAIN
TROUGH LAGGING BACK OVER THE SIERRA NEVADAS ON THUR. THE MAIN
UPPER LOW LAGS BACK OVER THE 4 CORNERS REGION INTO SAT BEFORE
MOVING INTO THE PLAINS SAT NIGHT. THIS IS ABOUT 12-24 HRS SLOWER
THAN THE PREVIOUS MODEL RUNS AND SEEMS LIKE ALL MODELS ARE
TRENDING SLOWER WITH THE UPPER LOW. SO WITH THAT LOOKS LIKE THE
COLD FRONT WILL BE SLOWER TO MOVE INTO THE AREA. WILL STILL KEEP
30 POPS AS THERE WILL BE GOOD MOISTURE AND THINK CONVECTION SHOULD
DEVELOP FRI/SAT BUT BEST CHANCES STILL LOOK TO BE MORE ON SUNDAY.
COLD FRONT IS SET TO PUSH THROUGH DURING THE DAY SUN PER
GFS/ECMWF. MAIN PROBLEM WILL BE TO WATCH AND SEE IF THE FRONT
STALLS BEFORE REACHING THE COAST. THIS MAY BE A POSSIBILITY SINCE
THERE WILL BE SOME UPPER LEVEL RIDGING AND THE FRONT COULD BECOME
MORE ORIENTED PARALLEL TO MEAN UPPER FLOW. THINK THIS MAY BE MORE
THE CASE AND EXPECT TO SEE MODELS TREND IN THIS DIRECTION.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 69 94 67 93 67 / 10 10 10 10 10
HOUSTON (IAH) 72 94 68 94 68 / 10 10 10 10 10
GALVESTON (GLS) 78 90 76 90 78 / 20 20 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 1 AM CDT TUESDAY FOR
THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA
SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 1 AM CDT TUESDAY 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.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 AM CDT TUESDAY 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.
&&
$$
DISCUSSION...23
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS SPOKANE WA
228 AM PDT Tue Sep 24 2013
.SYNOPSIS...
An upper level low will be the dominant weather feature through
much of the week. this will result in rain showers and mountain
snow showers at times through Thursday. Temperatures are expected
to remain well below normal. A warming and drying trend is
expected by the weekend.
&&
.DISCUSSION...
Tuesday and Tuesday night: A deep trof of low pressure will
carve into the Pac NW bringing a continuation of below normal
temperatures and unsettled weather. The most persistent area of
precipitation will focus across far southeastern WA and the lower
ID Panhandle however showers will be common across all mountains
surrounding the deep Basin and expanding at times into the West
Plains.
As of 2AM...a line of showers has developed from Mullan to
Pullman/Lewiston to Pendleton very close to where model guidance
indicated over the last 48 hours. Rainfall rates under this band
have generally be around 0.01 to 0.04" per hour. Expect this band
to sit in place until late Tuesday afternoon/early evening with
rainfall amounts spanning from a quarter to half an inch. Locally
higher amounts could be possible over the Camas Prairie;
especially if a few sun-breaks on Tuesday aftn add a convective
element.
Further north into the northeastern mountains of WA...Nrn ID
Panhandle...and Spokane-CDA area...a combination of afternoon
heating...orographics...and especially a shortwave passage during
the afternoon will also bring the threat for widely scattered
showers. This should be a bit more widespread and wetter then
Tuesday given the potential shortwave dynamics and PoPs may need
to be further increased for locations like Spokane...Deer Park...
Coeur D Alene...Sandpoint...and Bonners Ferry. Will be taking a
look at incoming HRRR runs and 12z guidance before deciding.
By this evening and overnight...the upper-level trof will become
firmly entrenched over the Pac NW. Cooling 500mb temperatures
near -25C will promote steepening midlevel lapse rates. A pressure
trof at the surface will begin to weaken and sag south and a cool
high pressure cell slipping into BC will create northerly
gradients across the CWA. This will draw cooler but drier air
southward into the CWA leading to a decreasing shower trend and
potential for locally gusty winds through the Okanogan Valley. A
few of the northern valleys like Republic...Deer Park...and Priest
Lake will be close to the freezing mark while most other lowlands
dip into the upper 30`s to mid 40`s. /sb
Wednesday and Wednesday Night: A closed low continues to pass to
the south of our forecast area but will still present some
unsettled conditions. Best chances for precipitation look to be
Tomorrow Afternoon in the ID Panhandle pushing back west into the
Blue Mtns. Rain showers will be the most likely mode of
precipitation...but a couple claps of thunder cannot be ruled out
with some weak instability in the Panhandle associated with the
trof and closed low. Precip amounts look to be pretty limited with
this system...but convective enhanced showers could bring moderate
showers for localized areas. By Wednesday Night the trof will be
pushing to the east limiting the overall chance for precipitation
in our forecast area.
Winds will be the main factor during this period with gusty
conditions expected Wednesday for the Okanogan Valley. Winds from
the north will channel down the valley enhancing the winds with
gusts in the range of 25 to 30mph. The gusty conditions will continue
down into the western Basin with values more in the 20 to 25mph
range. The winds will be something to monitor throughout the day
for the north-south oriented valleys in north Washington. Temperatures with
the northerly flow will be below normal with upper 50s and low 60s
for most locations minus the deep basin and lower valleys.
Overnight lows will be in the 30s and low 40s for most of the region.
Patchy frost was added for Wednesday Night as cold conditions will
continue into the overnight hours. Main focus for frost will be
the Republic area along with the Priest Lake and Deer Park areas. Fog
will also be present in some valley locations. Any areas with fog
will likely not see the frost as the fog will prevent strong
radiational cooling. Snow levels will remain lower allowing high
elevations in the Cascades and ID Panhandle to see some
flurries...but no lasting accumulations are expected. /Fliehman
Thursday through Monday...Model agreement is good and consistent
Thursday through Saturday. The deep trough over the region will
move off to the east on Thursday but some lingering shower
activity will continue primarily over the Idaho Panhandle and
possibly far eastern Washington. Temperatures will continue to run
below normal and locally breezy north winds especially down the
Okanogan and Purcell trenches will make for a somewhat raw day.
hings are looking up for the end of the week as the trough kicks
east into Montana and makes way for a weak but perceptible upper
level ridge to build over the region for Friday and Saturday. The
polar storm track will remain close by to the north during this
period...so while generally dry conditions are expected with
warming temperatures (up to about normal by Saturday) at least
partly cloudy conditions and a remote threat of some northern
mountain showers will prevail.
Beyond Saturday models begin to diverge and the moderate to high
confidence of the Thursday through Saturday period degrades to
low to moderate confidence in the far reaches of the extended
forecast. The ECMWF is much more aggressive about building a ridge
which implied dry and progressively warmer conditions through the
beginning of the next work week...while the GFS maintains a flat
and weaker ridge subject to flattening by weak transient
disturbances implying significant clouds and a small threat of
showers particularly on Sunday night and Monday with continued
seasonably normal temperatures. In any event it does appear that
models are in agreement that there will be no significant or
organized storm systems through early next week...and in this
regime it is a safe bet that the basin will remain dry while any
threat of showers remains confined to the northern mountains and
Cascades. /Fugazzi
&&
.AVIATION...
06Z TAFS: VFR through this evening for most locations as spotty
shower activity subsides, however to the southeast a frontal zone
forms and intensifies near Blue Mountains and over KLWS and KPUW
and up to Shoshone County in North Idaho. This frontal zone will
straighten enough and move little with time so as to keep rain and
associated ceilings down to MVFR in that same area after 12Z and
on through 00Z Wednesday until it moves away to the east near 06Z
Wednesday. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 59 40 59 42 63 43 / 20 20 20 10 10 10
Coeur d`Alene 56 40 57 41 62 41 / 30 30 30 10 10 10
Pullman 54 39 57 39 62 39 / 70 40 30 20 10 10
Lewiston 59 47 62 48 67 45 / 90 50 40 30 10 10
Colville 62 40 64 40 67 39 / 20 30 20 10 10 10
Sandpoint 53 36 56 36 60 35 / 40 40 30 10 10 10
Kellogg 50 39 54 39 57 39 / 80 50 30 30 20 10
Moses Lake 65 40 67 42 69 43 / 10 20 10 0 0 0
Wenatchee 64 45 66 45 68 47 / 10 20 30 0 0 0
Omak 64 39 67 40 68 42 / 10 20 10 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1107 PM CDT MON SEP 23 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 258 PM CDT MON SEP 23 2013
AFTERNOON WATER VAPOR IMAGERY OVERLAID WITH RAP 500 MB ANALYSIS
SHOWS RATHER DEEP NEGATIVELY TITLED UPPER LEVEL SHORTWAVE TROUGH
EJECTING OUT INTO THE CENTRAL PLAINS. AT THE SURFACE...A 997 MB
LOW RESIDES IN NW KANSAS WITH A NICE CURL SEEN IN VISIBLE
SATELLITE IMAGERY. IT IS THIS SYSTEM THAT WILL BE LIFTING TOWARD
THE UPPER MIDWEST TONIGHT INTO TUESDAY.
23.12Z GUIDANCE REMAINS SUPPORTIVE OF A DRY FORECAST WITH THIS
SYSTEM AS A COMBINATION OF WEAKENING DYNAMICS AND LIMITED
MOISTURE TRANSPORT LEAVES A LOT TO BE DESIRED. ACROSS THE
BOARD...500-300 MB PV ADVECTION...300-310K ISENTROPIC LIFT...AND
850 MB MOISTURE TRANSPORT ALL WEAKEN OR BECOME NON-EXISTENT
BETWEEN 06Z AND 15Z TUESDAY. OUTSIDE OF MID TO HIGH LEVEL CLOUDS
SPREADING IN FROM THE WEST INITIALLY WITH THE WARM AIR ADVECTION
WING...LITTLE TO NO IMPACT EXPECTED WITH THIS SYSTEM. PLAN ON
ANOTHER PLEASANT AUTUMN DAY WITH MOSTLY TO PARTLY SUNNY SKIES AND
HIGHS A COUPLE DEGREES ON EITHER SIDE OF 70F.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 258 PM CDT MON SEP 23 2013
DRY/QUIET WEATHER TUESDAY NIGHT THROUGH FRIDAY AS RIDGE OF HIGH
PRESSURE INFLUENCES THE SENSIBLE WEATHER ACROSS THE UPPER MIDWEST.
BY WEDNESDAY...THE AFOREMENTIONED SYSTEM DECAYS AND SLOWS ACROSS
THE MID ATLANTIC MEANWHILE A WESTERN CONUS SHORTWAVE TROUGH DIGS
DOWN NEAR THE FOUR CORNERS REGION. THIS PUTS THE CENTRAL PLAINS
UNDER DRY...WARMING SOUTHWESTERLY FLOW. 925 MB TEMPERATURES ARE
EXPECTED TO CLIMB EACH DAY...FROM NEAR SEASONAL LEVELS WEDNESDAY
TO SLIGHTLY ABOVE NORMAL BY THURSDAY...AND TO NEAR 80 IN SOME
SPOTS BY FRIDAY.
WEDNESDAY MORNING CONDITIONS LOOK SOMEWHAT FAVORABLE FOR RIVER
VALLEY FOG AS HIGH PRESSURE CENTERS ITSELF ACROSS CENTRAL
WISCONSIN. FORECAST SOUNDINGS SHOW A VERY DEEP LAYER OF LIGHT
WINDS LESS THAN 10 KTS UP TO 600 MB...THOUGH THERE IS A LACK OF
LOW LEVEL SATURATION...BUT COULD BE ENOUGH TO PATCHY RIVER VALLEY
FOG. THE OTHER COMPETING FACTOR IS THE POSSIBILITY OF A
NORTH/SOUTH ORIENTED MID LEVEL STRATUS DECK SETTING UP ALONG OR
JUST WEST OF THE MS RIVER. THIS IS SEEN IN THE GFS/NAM RH FIELDS
AT 850 AND 700 MB. FOR NOW...HAVE ADDED PATCHY VALLEY FOG TO MS
AND WISCONSIN RIVER VALLEYS.
FOCUS TURNS TO LATE FRIDAY NIGHT INTO THE UPCOMING WEEKEND SYSTEM
AS THE WESTERN SHORTWAVE TROUGH MOVES INTO THE NORTHERN AND
CENTRAL PLAINS. AS PIECES OF ENERGY ROUND THE SHORTWAVE TROUGH...A
COUPLE OF SURFACE LOWS ARE EXPECTED TO FORM...AND EVENTUALLY DRAG
A COLD FRONT THROUGH THE AREA. MOISTURE AHEAD OF THE FRONT
INCREASES...AND BROAD BUT PERSISTENT ISENTROPIC LIFT ON THE
305-315K SURFACES IS SEEN. THERE IS WEAK INSTABILITY ASSOCIATED
WITH THE SYSTEM...BUT MOST OF THE PRECIPITATION LOOKS TO BE POST-
FRONTAL. THE POSITIVE TILTED NATURE OF THE SHORTWAVE TROUGH MAKES
TIMING DETAILS A BIT UNCERTAIN AND DIFFICULT...AS THERE REMAINS
SOME DISAGREEMENT BETWEEN THE 23.12Z GUIDANCE. HOWEVER...ALL
GUIDANCE DID TREND MUCH SLOWER THAN PREVIOUS RUNS...THOUGH WITH
VARYING DEGREES. THE GEM/ECMWF SUGGESTS MOST OF SATURDAY WOULD
REMAIN DRY...HOLDING PRECIPITATION BACK UNTIL SATURDAY NIGHT OR
SUNDAY. THE GFS IS A TOUCH FASTER BUT STILL SLOWER THAN ITS
PREVIOUS RUN. AS A RESULT...HAVE PUSHED BACK PRECIPITATION
TIMING...ESPECIALLY EAST OF THE MISSISSIPPI RIVER. STILL PLENTY OF
TIME TO IRON OUT THE SPECIFICS. IN THE WAKE OF THIS SYSTEM...A
RETURN TO SEASONABLY COOL AND DRY WEATHER THANKS TO CANADIAN HIGH
PRESSURE BUILDING INTO THE UPPER MIDWEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1107 PM CDT MON SEP 23 2013
VFR CONDITIONS LOOK TO CONTINUE EVEN AS SLOW MOVING UPPER LOW
APPROACHES FROM THE CENTRAL PLAINS. AIRMASS REMAINS VERY DRY AND
WITH SYSTEM WEAKENING AS IT APPROACHES...NOT ENOUGH LIFT EXPECTED TO
GENERATE MORE THAN MID LEVEL CLOUD DECK. TIMING THAT IN MAY TAKE
AWHILE AS RIDGE HOLDS TOUGH TO THE EAST BUT INTRODUCED VFR CEILINGS
ADVECTING IN FROM WEST TO EAST THROUGH THE DAY TUESDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZT
LONG TERM....ZT
AVIATION.....SHEA
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1013 AM EDT TUE SEP 24 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 313 AM EDT TUE SEP 24 2013
AN UPPER LEVEL LOW ACCOMPANIED BY A SURFACE LOW WILL MOVE THROUGH
THE OHIO VALLEY TONIGHT AND WEDNESDAY BRINGING A CHANCE FOR RAIN TO
THE AREA. HIGH PRESSURE AND DRY CONDITIONS WILL THEN PERSIST THROUGH
THE FIRST HALF OF THE WEEKEND...UNTIL A COLD FRONT BRINGS ANOTHER
CHANCE FOR RAIN SATURDAY NIGHT INTO SUNDAY NIGHT. ABOVE AVERAGE
TEMPERATURES WILL GIVE WAY TO NEAR AVERAGE READINGS BY SUNDAY.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 956 AM EDT TUE SEP 24 2013
.UPDATE...
CURRENT FORECAST IS ON TRACK AND NO UPDATES ARE PLANNED AT THIS TIME.
ONLY CHANGE TO THE GRIDS WAS TO TWEAK HIGH UP A DEGREE SOUTHWEST
AS RAP HAD TEMPERATURES THERE NEAR 80 LATER TODAY.
.PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
A DRY EASTERLY FLOW WILL CONTINUE ACROSS THE FORECAST AREA DURING
THE DAY WITH HIGH PRESSURE OFF TO THE NORTHEAST. THIS WILL KEEP LOW
LEVELS PRETTY DRY. MEANWHILE...MID AND HIGH CLOUDS WILL INCREASE
THIS AFTERNOON AS AN UPPER SYSTEM AND SURFACE LOW BEGIN THEIR
APPROACH.
FORCING REMAINS TO THE WEST OF THE AREA UNTIL VERY LATE IN THE TODAY
PERIOD. LOW LEVELS REMAIN QUITE DRY THOUGH...SO FEEL THAT ANY
CHANCES FOR RAIN ACROSS THE FAR SOUTHWEST FORECAST AREA ARE TOO LOW
TO MENTION. WILL CONTINUE WITH A DRY FORECAST ALL AREAS TODAY.
A BLEND OF MODEL TEMPERATURES LOOKS GOOD GIVEN EXPECTED
CONDITIONS...AND THIS ENDS UP PRETTY CLOSE TO MAV MOS.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 313 AM EDT TUE SEP 24 2013
FOCUS IS ON CHANCES FOR RAIN EARLY IN THE PERIOD. WITH THE BIG
PICTURE MODELS ARE CLOSE ENOUGH. HOWEVER NAM LOOKS TO OVERDO LOW
LEVEL MOISTURE AS SEEN IN ITS HIGHER DEWPOINT FORECAST. THIS DOESN/T
LOOK REASONABLE GIVEN AN EASTERLY COMPONENT TO THE WINDS ACROSS THE
AREA THROUGH THE PERIOD. WENT CLOSER TO GFS/ECMWF UNLESS NOTED BELOW.
THE SURFACE LOW WILL WEAKEN AS IT MOVES SOUTHWEST OF THE AREA
TONIGHT AND WEDNESDAY. MOST OF THE FORCING WILL BE ALOFT WITH THE
UPPER LOW. HOWEVER MODEL TIME SECTIONS SHOW THAT BEST MOISTURE
DOESN/T LINE UP WITH BEST LIFT.
MODEL REFLECTIVITY FORECASTS FROM THE NCEP AND NSSL WRF SHOW LITTLE
RAINFALL WITH THE SYSTEM AS WELL. THUS CONFIDENCE FOR GETTING
MEASURABLE RAIN IS LOW. WILL UNDERCUT MOS POPS AND GO SLIGHT CHANCE
TO LOW CHANCE POPS ACROSS THE SOUTHERN FORECAST AREA TONIGHT INTO
WEDNESDAY. INSTABILITY IS MEAGER AT BEST SO WILL CONTINUE TO LEAVE
OUT THUNDER MENTION.
UPPER RIDGING AND SURFACE HIGH PRESSURE WILL THEN BUILD INTO THE
AREA FOR THE REMAINDER OF THE SHORT TERM PROVIDING MOSTLY CLEAR
SKIES AND DRY CONDITIONS.
FOR TEMPERATURES...GENERALLY STUCK WITH A BLEND OF MODELS...WHICH
ENDS UP NOT TOO FAR OFF FROM MAV MOS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 243 AM EDT TUE SEP 24 2013
RIDGING ALOFT AND A STRONG SURFACE HIGH PRESSURE RIDGE WILL REMAIN
THE MAIN INFLUENCES ON WEATHER OVER THE OHIO VALLEY FRIDAY THROUGH
THE FIRST HALF OF THE WEEKEND. WARM DRY WEATHER WILL CONTINUE
ACROSS THE REGION...HIGHLIGHTED BY MAINLY CLEAR SKIES AND TEMPS IN
THE UPPER 70S AND LOWER 80S FRIDAY AND SATURDAY.
EXTENDED MODEL GUIDANCE HAS CONTINUED TO SLOW THE APPROACH AND
ARRIVAL OF A COLD FRONT...WITH THE ECMWF...OP GFS AND GFS ENSEMBLE
MEAN ALL FAVORING BULK OF THE PRECIP COMING SUNDAY AS THE FRONT
SWINGS INTO THE OHIO VALLEY. FAVOR THE SLOWER SOLUTION CONSIDERING
THE OVERALL STRENGTH OF THE RIDGING ALOFT AND SURFACE HIGH...AND
THE TENDENCY FOR MODELS TO UNDERESTIMATE THAT STRENGTH AND BREAK
DOWN RIDGING TOO QUICKLY THIS FAR OUT. HAVE CUT BACK ON ALLBLEND
POPS SUBSTANTIALLY FOR SATURDAY NIGHT...KEEPING ONLY LOW CHANCE
POPS OVER THE NORTHERN WABASH VALLEY. WILL CONTINUE WITH 40-50
POPS SUNDAY WITH POPS DIMINISHING FROM WEST TO EAST SUNDAY NIGHT
AS THE FRONT SHIFTS EAST. WITH LITTLE INSTABILITY ACCOMPANYING THE
BOUNDARY...WILL ONLY CARRY ISOLATED THUNDER ON SUNDAY.
HIGH PRESSURE WILL RETURN TO BEGIN NEXT WEEK. HIGH TEMPS ARE
LIKELY TO FALL BACK INTO THE UPPER 60S AND LOWER 70S FOR MONDAY
AND TUESDAY AS COLD ADVECTION DEVELOPS IN WAKE OF THE FRONTAL
PASSAGE.
&&
.AVIATION /DISCUSSION FOR THE 24/1500Z TAF UPDATE/...
ISSUED AT 1011 AM EDT TUE SEP 24 2013
UPDATE...
NO CHANGES.
PREVIOUS DISCUSSION...
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.
CLEAR SKIES EARLY THIS MORNING WITH LIGHT EASTERLY FLOW. HAVE
NOTICED AN INCREASE IN STRATOCU ACROSS THE LOWER OHIO VALLEY OVER
THE LAST COUPLE HOURS AS THE UPPER WAVE APPROACHING FROM THE WEST
BEGINS TO INTERACT WITH MOISTURE LIFTING NORTH OUT OF THE LOWER
MISSISSIPPI VALLEY. EXPECT THIS TREND TO CONTINUE WITH A GRADUAL
INCREASE IN CLOUDS ACROSS THE OHIO VALLEY INTO THE AFTERNOON AS
THE UPPER WAVE NEARS THE REGION. WITH THAT BEING SAID...BELIEVE
BULK OF THE MODEL DATA THIS MORNING IS OVERDOING MOISTURE
ADVECTION INTO CENTRAL INDIANA LATER TODAY. MODEL SOUNDINGS
SHOWING AN ABUNDANCE OF DRY AIR AND DEEP SUBSIDENCE WHICH WILL
BE DIFFICULT TO BUDGE WITH PERSISTENT LOW LEVEL EASTERLY FLOW.
EXPECT SCATTERED VFR CU/STRATOCU TO EXPAND NORTH BY MIDDAY WITH
MID LEVEL CLOUDS INCREASING BY LATE AFTERNOON AS WELL. CLOUD
COVERAGE WILL INCREASE FURTHER TONIGHT AS THE UPPER WAVE MOVES
INTO THE REGION. NOT ENTIRELY CONVINCED THAT THE BOUNDARY LAYER
WILL COMPLETELY MOISTEN...WITH THE PREDOMINANT DECK LIKELY TO BE
IN THE MID LEVELS WHERE MOISTURE WILL BE MORE PREVALENT. COULD
SEE A FEW SHOWERS...ESPECIALLY AT KBMG AND POSSIBLY AT KHUF.
COVERAGE TOO SPARSE TO INCLUDE A MENTION IN THE FORECASTS AT THIS
TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50/JH
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN/TDUD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
956 AM EDT TUE SEP 24 2013
.UPDATE...
NEAR TERM FOR THE REST OF TODAY HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 313 AM EDT TUE SEP 24 2013
AN UPPER LEVEL LOW ACCOMPANIED BY A SURFACE LOW WILL MOVE THROUGH
THE OHIO VALLEY TONIGHT AND WEDNESDAY BRINGING A CHANCE FOR RAIN TO
THE AREA. HIGH PRESSURE AND DRY CONDITIONS WILL THEN PERSIST THROUGH
THE FIRST HALF OF THE WEEKEND...UNTIL A COLD FRONT BRINGS ANOTHER
CHANCE FOR RAIN SATURDAY NIGHT INTO SUNDAY NIGHT. ABOVE AVERAGE
TEMPERATURES WILL GIVE WAY TO NEAR AVERAGE READINGS BY SUNDAY.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 956 AM EDT TUE SEP 24 2013
.UPDATE...
CURRENT FORECAST IS ON TRACK AND NO UPDATES ARE PLANNED AT THIS TIME.
ONLY CHANGE TO THE GRIDS WAS TO TWEAK HIGH UP A DEGREE SOUTHWEST
AS RAP HAD TEMPERATURES THERE NEAR 80 LATER TODAY.
.PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
A DRY EASTERLY FLOW WILL CONTINUE ACROSS THE FORECAST AREA DURING
THE DAY WITH HIGH PRESSURE OFF TO THE NORTHEAST. THIS WILL KEEP LOW
LEVELS PRETTY DRY. MEANWHILE...MID AND HIGH CLOUDS WILL INCREASE
THIS AFTERNOON AS AN UPPER SYSTEM AND SURFACE LOW BEGIN THEIR
APPROACH.
FORCING REMAINS TO THE WEST OF THE AREA UNTIL VERY LATE IN THE TODAY
PERIOD. LOW LEVELS REMAIN QUITE DRY THOUGH...SO FEEL THAT ANY
CHANCES FOR RAIN ACROSS THE FAR SOUTHWEST FORECAST AREA ARE TOO LOW
TO MENTION. WILL CONTINUE WITH A DRY FORECAST ALL AREAS TODAY.
A BLEND OF MODEL TEMPERATURES LOOKS GOOD GIVEN EXPECTED
CONDITIONS...AND THIS ENDS UP PRETTY CLOSE TO MAV MOS.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 313 AM EDT TUE SEP 24 2013
FOCUS IS ON CHANCES FOR RAIN EARLY IN THE PERIOD. WITH THE BIG
PICTURE MODELS ARE CLOSE ENOUGH. HOWEVER NAM LOOKS TO OVERDO LOW
LEVEL MOISTURE AS SEEN IN ITS HIGHER DEWPOINT FORECAST. THIS DOESN/T
LOOK REASONABLE GIVEN AN EASTERLY COMPONENT TO THE WINDS ACROSS THE
AREA THROUGH THE PERIOD. WENT CLOSER TO GFS/ECMWF UNLESS NOTED BELOW.
THE SURFACE LOW WILL WEAKEN AS IT MOVES SOUTHWEST OF THE AREA
TONIGHT AND WEDNESDAY. MOST OF THE FORCING WILL BE ALOFT WITH THE
UPPER LOW. HOWEVER MODEL TIME SECTIONS SHOW THAT BEST MOISTURE
DOESN/T LINE UP WITH BEST LIFT.
MODEL REFLECTIVITY FORECASTS FROM THE NCEP AND NSSL WRF SHOW LITTLE
RAINFALL WITH THE SYSTEM AS WELL. THUS CONFIDENCE FOR GETTING
MEASURABLE RAIN IS LOW. WILL UNDERCUT MOS POPS AND GO SLIGHT CHANCE
TO LOW CHANCE POPS ACROSS THE SOUTHERN FORECAST AREA TONIGHT INTO
WEDNESDAY. INSTABILITY IS MEAGER AT BEST SO WILL CONTINUE TO LEAVE
OUT THUNDER MENTION.
UPPER RIDGING AND SURFACE HIGH PRESSURE WILL THEN BUILD INTO THE
AREA FOR THE REMAINDER OF THE SHORT TERM PROVIDING MOSTLY CLEAR
SKIES AND DRY CONDITIONS.
FOR TEMPERATURES...GENERALLY STUCK WITH A BLEND OF MODELS...WHICH
ENDS UP NOT TOO FAR OFF FROM MAV MOS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 243 AM EDT TUE SEP 24 2013
RIDGING ALOFT AND A STRONG SURFACE HIGH PRESSURE RIDGE WILL REMAIN
THE MAIN INFLUENCES ON WEATHER OVER THE OHIO VALLEY FRIDAY THROUGH
THE FIRST HALF OF THE WEEKEND. WARM DRY WEATHER WILL CONTINUE
ACROSS THE REGION...HIGHLIGHTED BY MAINLY CLEAR SKIES AND TEMPS IN
THE UPPER 70S AND LOWER 80S FRIDAY AND SATURDAY.
EXTENDED MODEL GUIDANCE HAS CONTINUED TO SLOW THE APPROACH AND
ARRIVAL OF A COLD FRONT...WITH THE ECMWF...OP GFS AND GFS ENSEMBLE
MEAN ALL FAVORING BULK OF THE PRECIP COMING SUNDAY AS THE FRONT
SWINGS INTO THE OHIO VALLEY. FAVOR THE SLOWER SOLUTION CONSIDERING
THE OVERALL STRENGTH OF THE RIDGING ALOFT AND SURFACE HIGH...AND
THE TENDENCY FOR MODELS TO UNDERESTIMATE THAT STRENGTH AND BREAK
DOWN RIDGING TOO QUICKLY THIS FAR OUT. HAVE CUT BACK ON ALLBLEND
POPS SUBSTANTIALLY FOR SATURDAY NIGHT...KEEPING ONLY LOW CHANCE
POPS OVER THE NORTHERN WABASH VALLEY. WILL CONTINUE WITH 40-50
POPS SUNDAY WITH POPS DIMINISHING FROM WEST TO EAST SUNDAY NIGHT
AS THE FRONT SHIFTS EAST. WITH LITTLE INSTABILITY ACCOMPANYING THE
BOUNDARY...WILL ONLY CARRY ISOLATED THUNDER ON SUNDAY.
HIGH PRESSURE WILL RETURN TO BEGIN NEXT WEEK. HIGH TEMPS ARE
LIKELY TO FALL BACK INTO THE UPPER 60S AND LOWER 70S FOR MONDAY
AND TUESDAY AS COLD ADVECTION DEVELOPS IN WAKE OF THE FRONTAL
PASSAGE.
&&
.AVIATION /DISCUSSION FOR 241200Z TAF ISSUANCE/...
ISSUED AT 603 AM EDT TUE SEP 24 2013
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.
CLEAR SKIES EARLY THIS MORNING WITH LIGHT EASTERLY FLOW. HAVE
NOTICED AN INCREASE IN STRATOCU ACROSS THE LOWER OHIO VALLEY OVER
THE LAST COUPLE HOURS AS THE UPPER WAVE APPROACHING FROM THE WEST
BEGINS TO INTERACT WITH MOISTURE LIFTING NORTH OUT OF THE LOWER
MISSISSIPPI VALLEY. EXPECT THIS TREND TO CONTINUE WITH A GRADUAL
INCREASE IN CLOUDS ACROSS THE OHIO VALLEY INTO THE AFTERNOON AS
THE UPPER WAVE NEARS THE REGION. WITH THAT BEING SAID...BELIEVE
BULK OF THE MODEL DATA THIS MORNING IS OVERDOING MOISTURE
ADVECTION INTO CENTRAL INDIANA LATER TODAY. MODEL SOUNDINGS
SHOWING AN ABUNDANCE OF DRY AIR AND DEEP SUBSIDENCE WHICH WILL
BE DIFFICULT TO BUDGE WITH PERSISTENT LOW LEVEL EASTERLY FLOW.
EXPECT SCATTERED VFR CU/STRATOCU TO EXPAND NORTH BY MIDDAY WITH
MID LEVEL CLOUDS INCREASING BY LATE AFTERNOON AS WELL. CLOUD
COVERAGE WILL INCREASE FURTHER TONIGHT AS THE UPPER WAVE MOVES
INTO THE REGION. NOT ENTIRELY CONVINCED THAT THE BOUNDARY LAYER
WILL COMPLETELY MOISTEN...WITH THE PREDOMINANT DECK LIKELY TO BE
IN THE MID LEVELS WHERE MOISTURE WILL BE MORE PREVALENT. COULD
SEE A FEW SHOWERS...ESPECIALLY AT KBMG AND POSSIBLY AT KHUF.
COVERAGE TOO SPARSE TO INCLUDE A MENTION IN THE FORECASTS AT THIS
TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50/JH
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1058 AM CDT TUE SEP 24 2013
.DISCUSSION...
PRETTY STRAIGHT FORWARD BACK EDGE OF CLOUDS DRAPED FROM SE
AR...ACROSS NE/CEN LA AND DEEP E TX. AS FOR THE MORNING
RAINFALL...WE SEE THE BACK EDGE FROM JENA...TO JUST SOUTH OF
KISATCHIE. THE NAM 12Z IS DRY FOR THE REST OF THE DAY AND WOULD
TEND TO AGREE...BUT RAP DOES KEEP A SLIGHT BIT OF QPF OVER THE
AFORE MENTIONED CLOUD AREAS INTO THE MID AFTERNOON AS A SECONDARY
SHARP TROUGH DROPS QUICKLY INTO PLAY DUE TO THE NEGATIVE TILT OF
THE PARENT VORT OVER MO. IT/S INITIAL AXIS THAT DEVELOPED ALL OF THIS
MORNING/S RAIN IS LOCATED FROM MEMPHIS...TO VICKSBURG...TO LUFKIN.
THIS SECOND PUSH EXTENDS FROM NW AR INTO SE OK AND WILL SCOUR ANY
REMAINING MOISTURE SHORTLY. CLEARLY...THERE IS NOT MUCH MOISTURE IN
THE MID OR UPPER LEVELS...BUT SFC TDS REMAIN HIGH OVER OUR SE QUAD
THROUGH THE AFTERNOON WITH STRONGER SFC WINDS NOW OVER OKC
KNOCKING ON OUR NW DOOR. A SPOTTY CU FIELD MAY BE REVEALED LATER
THIS AFTERNOON. WE HAVE MADE SOME ADJUSTMENTS TO HIGHS CONSIDERING
CURRENT READINGS...AND IN THE LIGHT WIND ENVIRONMENT SHOULD TACK
ON ANOTHER 10 DEGREES OR SO BY MID AFTERNOON AHEAD OF ANY MIXING
LOW LEVEL WINDS. THE SLIGHT CHANCE OF ADDITIONAL SHOWERS OR
ISOLATED THUNDERSTORMS COULD END BEFORE OUR NEXT PRODUCT ISSUANCE.
/24/
&&
.AVIATION...
MAINLY VFR FLIGHT CONDITIONS EXPECTED DURING THE UPCOMING 24 HOUR
TAF PERIOD ENDING 25/18Z. NORTHWEST WINDS UP TO 10 KNOTS TODAY TO
DIMINISH TO AROUND 5 KNOTS OVERNIGHT AND INCREASE SLIGHTLY TO 5 TO
10 KNOTS ON WEDNESDAY. /05/
&&
.PREV DISCUSSION... /ISSUED 601 AM CDT TUE SEP 24 2013/
DISCUSSION...
CURRENT RADAR COVERAGE WARRANTS A QUICK UPDATE TO RAISE POPS
ACROSS N CENTRAL LA/SRN AR FOR TODAY. WITH RADAR TRENDS ON THE
UPTICK...LIKELY POPS SEEM TO BE A GOOD FIT. EXPECT THAT COVERAGE
WILL BEGIN DECREASING THIS AFTERNOON...AS THE UPPER LOW MOVES EWD
AWAY FROM THE REGION. UPDATED PRODUCTS ALREADY OUT. /12/
PREV DISCUSSION... /ISSUED 338 AM CDT TUE SEP 24 2013/
DISCUSSION...
MOISTURE FROM A SFC LOW IN THE COASTAL BEND REGION OF THE WRN GULF IS
INTERACTING WITH A NEGATIVELY TILTED UPPER TROF MOVING ACROSS THE
PLAINS THIS MORNING...PRODUCING SHOWERS AND ISOLD THUNDERSTORMS
ACROSS THE ERN HALF OF THE REGION. MODELS A BIT MORE AGGRESSIVE
THIS RUN WITH PRECIP FOR THESE AREAS TODAY...AND HAVE ADJUSTED
UPWARDS ACCORDINGLY...ESPECIALLY ACROSS N CENTRAL LA. UPPER TROF
IS FCST TO PUSH EWD TODAY...WITH RAIN ENDING BY THIS EVENING.
UPPER RIDGE WILL MOVE BACK OVHD BY MID WEEK...KEEPING US DRY AND
ABOVE NORMAL TEMP-WISE THROUGH FRIDAY...AHEAD OF ANOTHER
DISTURBANCE AND COLD FRONT SWEEPING ACROSS THE PLAINS. TIMING OF
THE ARRIVAL OF THE FRONT AND ASSOCIATED CONVECTION DIFFERS BETWEEN
THE GFS AND EURO...WITH THE EURO BRINGING IT IN A LITTLE EARLIER.
AT ANY RATE...BOTH MODELS SHOW DECENT QPF WITH THE FRONT AS
EARLY AS SATURDAY AFTERNOON...AND CONTINUING THROUGH AT LEAST THE
FIRST HALF OF MONDAY. HAVE PRETTY MUCH STUCK WITH THE ONGOING
CONSERVATIVE POPS FOR THIS TIMEFRAME DUE TO THE UNCERTAINTY IN
TIMING. IN THE WAKE OF THE FRONT...TEMPS ARE EXPECTED TO RETURN TO
NEAR OR JUST BELOW NORMAL FOR SUNDAY THROUGH THE END OF THE PD.
/12/
AVIATION...
MOSTLY VFR FLIGHT WEATHER EXPECTED DURING THE UPCOMING 24 HOUR TAF
PERIOD ENDING 25/12Z. HOWEVER...EARLY IN PERIOD THROUGH 18Z...
EXPECT SOME MARGINAL FLIGHT CONDITIONS FROM DEEP EAST TEXAS INTO
NORTH LOUISIANA DUE TO SCATTERED CONVECTION. CIGS AREA WIDE THIS
MORNING WILL RUN AROUND 5 KFT...HOWEVER IN THE CONVECTIVE AREA
EXPECT OCCASIONAL CIGS 1 TO 3 KFT WITH VSBYS 3 TO 5 MI IN RAIN AND
FOG. ALSO...POCKETS OF TURBULENCE COULD BE AN ISSUE FROM ISOLATED
TSTMS. AFTER 18Z...CLEAR SKIES SHOULD RETURN TO MOST OF EAST
TEXAS...SOUTHEAST OKLAHOMA AND ADJACENT SOUTHWEST ARKANSAS WITH
IMPROVING CIGS FARTHER EAST BY 25/00Z. /14/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 92 62 91 65 92 / 10 10 10 10 10
MLU 89 63 89 64 91 / 30 10 10 10 10
DEQ 87 58 88 59 90 / 10 10 10 10 10
TXK 89 61 87 62 89 / 10 10 10 10 10
ELD 89 60 88 61 89 / 20 10 10 10 10
TYR 90 61 90 64 93 / 10 10 10 10 10
GGG 91 59 89 62 92 / 10 10 10 10 10
LFK 93 62 92 63 94 / 10 10 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
24/05
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
729 AM EDT TUE SEP 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 336 AM EDT TUE SEP 24 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW AN UPR RDG OVER
THE GREAT LKS BTWN A CLOSED LO OVER THE CNDN MARITIMES AND A LARGER
SCALE TROF OFF THE W COAST. SFC HI PRES UNDER THE SLOWLY BLDG UPR
RDG IN THE GREAT LKS EXTENDS FM QUEBEC SWWD TO NEAR THE SAULT. WITH
THE LARGER SCALE SUBSIDENCE AND BONE DRY MID LVLS ABV THE SUBSIDENCE
INVRN SHOWN AT H9 ON THE 00Z GRB RAOB...SKIES ARE CURRENTLY MOCLR.
ALTHOUGH A LLVL SE FLOW IS PRESENT OVER NRN LK MI ON THE WRN FLANK
OF THE SFC RDG AXIS LIKE YESTERDAY MRNG...THERE IS SO FAR NO LO CLD
SHOWING UP OVER NRN LK MI DUE TO PRESENCE OF WARMER/DRIER AIR BLO A
LOWER INVRN BASE THAN WAS PRESENT 24 HRS AGO. SFC TEMPS HAVE STILL
DIPPED AS LO AS THE 30S AT SOME OF THE COLD SPOTS OVER THE INTERIOR
SCENTRAL AND E UNDER A FLATTER PRES GRADIENT CLOSER TO THE RDG AXIS.
A SHARPER PRES GRADIENT/STRONGER SW FLOW IS RESTRICTING THE DIURNAL
TEMP DROP OVER THE W AND NCENTRAL NEAR LK SUP. LOOKING FARTHER TO
THE W...A FAIRLY VIGOROUS NEGATIVELY TILTED SHRTWV IS PRESENT OVER
THE CENTRAL PLAINS AND LIFTING ENEWD E OF THE WRN TROF. PCPN AND
EVEN MUCH IN THE WAY OF CLDS IN ADVANCE OF THIS FEATURE AND
ACCOMPANYING SFC LO IN NEBRASKA ARE LIMITED BY VERY DRY AIR SHOWN ON
NEARBY 00Z RAOBS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE POTENTIAL LO CLDS NEAR LK
MI AND TEMPS. WITH CLOSED LO SPINNING OVER THE CNDN MARITIMES...THE
PATTERN WL REMAIN NEARLY STAGNANT THRU TNGT. WITH THE UPR RDG
REMAINING NEARLY STNRY OVER THE GREAT LKS...SHRTWV MOVING E THRU THE
PLAINS IS PROGGED TO WEAKEN AND PASS WELL TO THE S OF UPR MI AND
HAVE NO IMPACT ON THE CWA.
TODAY...ALTHOUGH NO CLDS HAVE FORMED AS OF 06Z...SOME OF THE SHORTER
TERM MODELS HINT SOME LK EFFECT LO CLDS WL FORM OVER NRN LK MI AND
THE SE CWA THRU SUNRISE AIDED BY NOCTURNAL COOLING OF SHALLOW SUB
INVRN LYR. ON THE OTHER HAND...SOME OF THE HIER RESOLUTION GUIDANCE
THAT HAS HAD A GOOD TRACK RECORD WITH THIS LO CLD IN RECENT DAYS...
SPECIFICALLY THE 00Z LOCAL WRF-ARW MODEL AND SOME RAPID UPDATE
MODELS...SHOW LIMITED LK EFFECT LO CLDS. GIVEN THE WARMER TEMPS
OBSVD AT THE INVRN BASE...SUSPECT FOG RELATED TO RADIATION COOLING
OVER LAND WL BE MORE LIKELY AT LEAST OVER THE INTERIOR SCENTRAL AND
E. SO ADDED SOME FOG/LO CLD IN THIS AREA INTO MID MRNG. WITH LOWER
SUN ANGLE...SOME LO CLD MIGHT LINGER INTO EARLY AFTN BEFORE BURNING
OFF. OVER THE W...ABUNDANT SUNSHINE IN THE PRESENCE OF H85 TEMPS
NEAR 12Z WL BOOST MAX TEMPS INTO THE 70S AWAY FM THE INFLUENCE OF LK
SUP IN LLVL E-SE FLOW. AREAS OVER THE E AND SCENTRAL WL BE COOLER...
ESPECIALLY IF ANY LO CLDS THAT FORM ARE MORE EXTENSIVE AND LINGER
LONGER.
TNGT...WITH A WEAKER PRES GRADIENT TNGT AS THE SFC HI PRES RDG
EXPANDS A BIT TO THE W AND MID LVL DRY AIR/PWAT NEAR 0.50 INCH
LINGERING...TENDED TOWARD THE LO END OF GUIDANCE FOR MIN TEMPS UNDER
MOCLR SKIES. EXPECT SOME FOG TO DVLP UNDER THESE CONDITIONS WITH
LENGTHENING DARKNESS. THERE MAY ALSO BE SOME FROST AT SOME OF THE
INTERIOR COLDER LOCATIONS... BUT THE EXPECTED COVERAGE SHOULD NOT BE
ENUF TO JUSTIFY A FROST ADVY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 336 AM EDT TUE SEP 24 2013
THE SECOND HALF OF THE WORK WEEK WILL SEE THE AREA REMAINING UNDER
THE INFLUENCE OF THE UPPER RIDGE OVER THE GREAT LAKES AND ONTARIO
AND A SURFACE HIGH STATIONED OVER EASTERN ONTARIO AND WESTERN
QUEBEC. THIS SETUP WILL CONTINUE WARM AND DRY CONDITIONS OVER THE
U.P. THROUGH FRIDAY. WILL CONTINUE THE MOSTLY SUNNY IDEA FOR THE
FORECAST WITH HIGHS IN THE UPPER 60S AND LOWER 70S EACH DAY.
FOR THE WEEKEND...THE UPPER TROUGH CURRENTLY APPROACHING THE
PACIFIC NORTHWEST WILL BEGIN TO MOVE OUT OF THE ROCKIES ON FRIDAY
AND THROUGH THE UPPER GREAT LAKES REGION THIS WEEKEND. LATEST
GFS/CANADIAN RUNS HAVE TRENDED TOWARDS THE SLOWER ECMWF RUN AND
WILL CONTINUE TO TREND THE POP FORECASTS TOWARDS THAT SLOWER
SOLUTION. THAT SEEMS REASONABLE WITH THE STRONG RIDGE OVER OUR
AREA AND THE SLOW TO EXIT LOW DEPARTING THE CANADIAN MARITIMES. NOW
INSTEAD OF THE FRONT AND UPPER TROUGH MOVING THROUGH FRIDAY NIGHT
AND SATURDAY (AS SHOWN THE LAST COUPLE OF NIGHTS)...THEY LOOK TO
MOVE ACROSS THE AREA SATURDAY NIGHT INTO SUNDAY. THERE COULD
STILL BE SOME SHOWERS OVER WESTERN LAKE SUPERIOR AND POTENTIALLY
WESTERN UPPER MICHIGAN FRIDAY NIGHT INTO SATURDAY...ASSOCIATED WITH
AN AREA OF FGEN ALONG THE ELONGATED SURFACE TROUGH THAT IS SETUP
OVER THE MN ARROWHEAD. THUS...WILL KEEP AT LEAST SOME SLIGHT CHANCE
POPS OVER THE WESTERN THIRD OF THE CWA FOR FRIDAY NIGHT INTO
SATURDAY BEFORE TRANSITIONING IT ACROSS THE REST OF THE CWA. WITH
THE LATEST TRENDS...THERE COULD BE A DECENT SOAKING RAIN FOR THE
WESTERN CWA DUE TO SLOW EASTWARD MOVEMENT AND SOUTHWESTERLY FLOW
AHEAD OF THE TROUGH. THAT AREA HAS BEEN DRY THIS MONTH...SO IT
WILL BE MUCH NEEDED. FINALLY...OPTED TO REMOVE THUNDER FROM ALL BUT
FAR WESTERN LAKE SUPERIOR (FRIDAY AFTERNOON/EVENING) AS
SHOWALTERS CONTINUE TO LOOK MARGINAL WITH VERY LIMITED MUCAPE VALUES
(LESS THAN 150 J/KG).
MODELS DIFFERENCES GROW HEADING INTO NEXT WEEK...AS THE
ECMWF/CANADIAN CONTINUE TO REINFORCE THE UPPER TROUGH IN THE
UPPER GREAT LAKES. MEANWHILE...THE 18Z GFS WAS VERY PROGRESSIVE AND
THE 00Z GFS IS HALFWAY BETWEEN THE PREVIOUS RUN AND THE
ECMWF/CANADIAN/GFS-ENS. LATE ARRIVING 00Z ECMWF HAS MOVED IN A
SLIGHTLY DIFFERENT DIRECTION...WITH WEAK RIDGING BEFORE ANOTHER
WAVE ON TUESDAY. THUS...WILL JUST GO WITH A SILENT 20 POP.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 728 AM EDT TUE SEP 24 2013
LO CLDS THIS MRNG AT SAW ASSOCIATED WITH AN UPSLOPE SSE FLOW ARND
STNRY HI PRES IN SE CANADA WL SLOWLY DSPT BY THIS AFTN WITH DAYTIME
HEATING/MIXING. SINCE IWD/CMX ARE DOMINATED BY A DOWNSLOPE S WIND
COMPONENT...THESE LOCATIONS WL EXPERIENCE VFR CONDITIONS THRU THE
DAY. MORE FOG/IFR CONDITIONS WL DVLP AT SAW TNGT WITH MOCLR SKIES/
LGT WINDS AS SFC HI PRES EXPANDS WWD BACK INTO THE UPR LKS. SOME FOG
MAY ALSO IMPACT CMX...BUT A BIT STRONGER S WIND EXPECTED AT IWD
SHOULD KEEP THAT LOCATION FOG FREE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 336 AM EDT TUE SEP 24 2013
WITH RELATIVELY WEAK PRES GRADIENT OVER THE UPPER GREAT LAKES...
EXPECT WINDS INTO FRI TO REMAIN UNDER 20 KTS. THE APPROACH OF A COLD
FRONT TOWARD SAT AND SHARPENING PRES GRADIENT MAY LEAD TO A BIT
STRONGER S WINDS UP TO 20-25 KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
911 AM CDT TUE SEP 24 2013
.UPDATE...
ISSUED AT 904 AM CDT TUE SEP 24 2013
LOW LEVEL STRATUS WILL BE SLOW TO CLEAR ACROSS THE AREA THIS
MORNING...WITH A FEW BREAKS ALREADY EVIDENT ACROSS THE WESTERN
FRINGES OF THE CWA. EXPECT THIS STRATUS TO CLEAR FROM WEST TO EAST
THROUGH THE AFTERNOON...WITH SOME PATCHY DRIZZLE POSSIBLE ACROSS
NORTHEASTERN AREAS THROUGH ABOUT NOON. OTHER THAN INCREASING
CLOUD COVER AND ADDING SOME PATCHY DRIZZLE PER REPORTS FROM AROUND
THE REGION...NO OTHER CHANGES NECESSARY TO THE INHERITED FORECAST
AS TEMPERATURES LOOK ON TRACK AND A MOSTLY SUNNY AFTERNOON WILL
EVENTUALLY EMERGE ACROSS MOST...IF NOT ALL...OF THE LOCAL FORECAST
AREA.
UPDATE ISSUED AT 700 AM CDT TUE SEP 24 2013
AS DISCUSSED IN GREATER DETAIL IN THE PRIMARY OVERNIGHT
DISCUSSION...LOW STRATUS TRENDS CONTINUE TO BE A HEADACHE.
ALTHOUGH A FEW CORRIDORS OF CLEARING REMAIN...MUCH OF THE CWA IS
NOW UNDER FAIRLY WIDESPREAD LOW CLOUDS...WITH THE HRRR SUGGESTING
THAT GENERALLY THE EASTERN 3/4 OF THE CWA COULD REMAIN FAIRLY
SOCKED IN THROUGH MID-DAY. AS A RESULT...YET AGAIN BUMPED UP SKY
COVER PERCENTAGES AND SLOWED THE RATE OF WEST-TO-EAST
CLEARING...BUT STILL THINKING THAT MOST AREAS SHOULD AVERAGE NO
WORSE THAN PARTLY CLOUDY THROUGH THE BALANCE OF THE AFTERNOON.
WILL STAY THE COURSE WITH PREVIOUS HIGH TEMPS FOR NOW...AS ANY
CLEARING SHOULD RESULT IN A QUICK RISE AND HELP OFFSET ANY POTENTIAL
DELAY IN WARMING FROM MORNING CLOUD COVER. ON ONE FINAL
NOTE...RADAR TRENDS SUPPORTED KILLING THE SLIGHT POPS THAT
ORIGINALLY LINGERED IN A FEW FAR NORTHEAST COUNTIES THROUGH
15Z/10AM...SO NOW THE FORECAST IS OFFICIALLY VOID OF ALL PRECIP
MENTION UNTIL THURS NIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM CDT TUE SEP 24 2013
ALTHOUGH MOST IF NOT ALL OF THE CWA IS LOOKING AT A DRY AND FAIRLY
UNEVENTFUL UPCOMING 24 HOURS...ESPECIALLY THE DAYTIME HOURS HAVE
BECOME TRICKIER-THAN-EXPECTED MAINLY REGARDING THE EVOLUTION OF
SKY COVER/TEMPERATURES...AS LOW CLOUDS COULD BE STUBBORNLY SLOW TO
DEPART MAINLY WITHIN THE EASTERN 1/2 OF THE CWA...BRINGING 5+ DEGREE
TEMP BUST POTENTIAL VERY MUCH INTO PLAY.
08Z OBJECTIVE SURFACE ANALYSIS HIGHLIGHTS A SLOWLY-WEAKENING 1004
MILLIBAR LOW PRESSURE CENTER...CENTERED OVER THE CLAY/FILLMORE
COUNTY AREA...WHILE IN ITS WAKE THE LEADING EDGES OF HIGH PRESSURE
AROUND 1016MB HAS WORKED INTO THE NEB PANHANDLE. WITH THE MAJORITY
OF THE CWA POSITIONED BEHIND THE DEPARTING LOW...EARLY MORNING
BREEZES ARE MAINLY FROM THE WEST-NORTHWEST...WITH THE STRONGEST
SPEEDS WITH GUSTS OF 20+ MPH FOCUSED ACROSS THE SOUTHWESTERN HALF
OF THE AREA...WITH LIGHTER SPEEDS STILL HOLDING ON FOR AT LEAST A
FEW MORE HOURS WITHIN MUCH OF THE NORTHEAST 1/2. ALOFT...WATER
VAPOR IMAGERY AND SHORT TERM MODEL DATA CLEARLY REVEAL A WELL-
DEFINED...NOT QUITE VERTICALLY STACKED LOW PRESSURE SYSTEM
DEPARTING EASTWARD ACROSS THE EASTERN 1/4 OF NEB...WITH A CLOSED
500MB CIRCULATION CENTERED NEAR NORFOLK. AS A RESULT...THE PRIMARY
MID LEVEL CONVERGENCE/DEFORMATION ZONE AT THIS HOUR IS FOCUSING
WIDESPREAD MAINLY LIGHT RAIN 50+ MILES NORTHEAST OF THE
CWA. CLOUD-WISE...11-3.9 MICRON SATELLITE IMAGERY DEPICTS A
FAIRLY COMPLEX AND EVER-CHANGING MIXTURE OF CLEAR SKIES ALONG WITH
PASSING BATCHES OF MID CLOUDS AND LOW STRATUS. WHILE MOST OF THESE
LOWER CEILINGS WITHIN THE CWA ARE AT/ABOVE 1500 FT...A CORRIDOR OF
LOWER CEILINGS BETWEEN 500-1000 FT SEEMS TO BE LURKING JUST
NORTHWEST OF THE CWA ALONG A BROKEN BOW-AINSWORTH AXIS...WITH
THESE LOW CLOUDS POSSIBLY EVEN SUPPORTING SOME PATCHY LIGHT
DRIZZLE. TEMP-WISE...MOST OF THE CWA APPEARS HEADED FOR OVERNIGHT
LOWS IN THE MID 50S...WITH ANY LOW 50S/UPPER 40S MOST FAVORED IN
FAR WESTERN COUNTIES.
AS THE EARLY MORNING/DAYTIME HOURS WEAR ON...THE BIG PICTURE ALOFT
INVOLVES THE MID LEVEL SHORTWAVE TROUGH/ASSOCIATED CLOSED LOW
CONTINUING ITS STEADY TREK EASTWARD...WITH THE 500MB CIRCULATION
CENTER INTO SOUTHWEST IA BY 18Z...AND THEN OVER NORTH CENTRAL MO
BY 00Z/7PM. AS THIS LOW DEPARTS...A BROAD AREA OF SHORTWAVE
RIDGING AND ASSOCIATED HEIGHT RISES WILL OVERSPREAD THE CENTRAL
PLAINS. AT THE SURFACE...THE LOW PRESSURE CENTER CURRENTLY OVER
SOUTHEAST NEB WILL CONTINUE TO WEAKEN AS IT SLIDES INTO CENTRAL MO
OVER THE COURSE OF THE DAY...ALLOWING A MODEST RIDGE AXIS TO BUILD
INTO THE LOCAL AREA WITH TIME AND RELAX THE SURFACE PRESSURE
GRADIENT. HOWEVER...BREEZES WILL STILL BE FAIRLY ELEVATED FOR
MUCH OF THE DAY TODAY...LARGELY OWING TO MIXING CLIMBING UP TO
AROUND 850MB...WHERE AN ENHANCED CORRIDOR OF 30-40KT NORTHERLY
WINDS WILL LINGER THROUGH MID-DAY BEFORE STEADILY WEAKENING IN THE
AFTERNOON. THE NET RESULT WILL BE SUSTAINED NORTH-NORTHWEST WIND
SPEEDS 15-20 MPH WITH GUSTS 25+ MPH THROUGH THIS MORNING...BEFORE
DIMINISHING TO MORE SO SUSTAINED 10-15 MPH SPEEDS THIS
AFTERNOON...AND ONLY 5-10 MPH CLOSER TO SUNSET. AS FOR PRECIP
CHANCES...ALTHOUGH RADAR TRENDS AND SHORT TERM MODEL DATA
INCLUDING THE HRRR PRETTY STRONGLY SUGGEST THAN ANY RISK OF
MEASURABLE LIGHT RAIN SHOULD BE OVER BY 12Z...WENT AHEAD AND
LINGERED A TOKEN 20 POP IN THE EXTREME NORTHEAST
NANCE/MERRICK/POLK AREA THROUGH 15Z IN CASE SOMETHING MANAGES TO
STILL WRAP AROUND THE BACK SIDE OF THE LOW. THE BIG CHALLENGE
TODAY SEEMS TO BE CENTERED AROUND SKY COVER. 24 HOURS AGO...IT WAS
ASSUMED THAT MID LEVEL CLOUDS WOULD QUICKLY MOVE OFF EAST OF THE
CWA TODAY WITH THE PARENT SYSTEM. HOWEVER...LATEST SATELLITE AND
SHORT TERM MODEL DATA INCLUDING THE HRRR LOW CLOUD PRODUCT NOW
SUGGEST THAT THE AREAL COVERAGE OF LOW STRATUS MAY IN FACT
INCREASE BEFORE SUNRISE FROM THE NORTHWEST...AND THEN POSSIBLY
HANG VERY STUBBORNLY MAINLY ACROSS THE CENTRAL/EASTERN CWA EVEN
INTO THE AFTERNOON HOURS. ALTHOUGH HAVE NOT BOUGHT FULL-BORE INTO
THE VERY PESSIMISTIC RUC/HRRR SOLUTIONS REGARDING LOW CLOUDS
TODAY...DID INCREASE SKY COVER PERCENTAGES VERSUS PREVIOUS...AND
ALSO DELAYED THE WEST-EAST CLEARING TREND. HOWEVER...PLEASE NOTE
THAT ESPECIALLY EASTERN COUNTIES ALONG/NEAR HIGHWAY 81 MAY REALLY
STRUGGLE TO SEE MUCH SUN UNTIL MAYBE LATE AFTERNOON...AND DAY
SHIFT MAY HAVE TO MAKE SOME PRETTY NOTICEABLE ADJUSTMENTS TO SKY
COVER AND RESULTANT HIGH TEMPS. FOR NOW THOUGH...OPTED TO ONLY
SHAVE 1-2 DEGREES OFF PREVIOUS HIGHS IN MOST AREAS...RANGING FROM
LOW 70S FAR EAST TO UPPER 70S FAR SOUTHWEST...AND AROUND 73 TRI-
CITIES. IF CLOUDS ARE SLOW TO DEPART HOWEVER...SOME EASTERN AREAS
MAY STRUGGLE TO LEAVE THE 60S. ON ONE FINAL DAYTIME
NOTE...ALTHOUGH HAVE DEWPOINTS DROPPING INTO THE LOW-MID 40S
ACROSS MUCH OF THE WESTERN CWA DURING THE AFTERNOON...THESE VALUES
ARE NOT QUITE AS LOW AS ANTICIPATED 24 HOURS AGO...AND THIS KEEPS
ANY AFTERNOON RELATIVE HUMIDITY VALUES AS LOW AS 25-30 PERCENT
CONFINED TO MAINLY JUST THE FURNAS COUNTY AREA.
FOR THE EVENING/NIGHT 00Z-12Z PERIOD...WILL RUN WITH THE
ASSUMPTION THAT EVEN IF LOW STRATUS LINGERS QUITE AWHILE INTO THE
AFTERNOON IN SOME AREAS...THAT IT SHOULD BE SAFELY EAST OF THE CWA
BY SUNSET...THUS RESULTING IN A CLEAR OVERNIGHT AREA-WIDE WITH
ESSENTIALLY ZERO RISK OF PRECIP. ON THE BIG PICTURE...THE HEART OF
THE AFOREMENTIONED MID/UPPER LEVEL SHORTWAVE RIDGE AXIS WILL PASS
DIRECTLY OVER THE CWA...VERY SIMILAR TO LAST FRIDAY NIGHT. ALSO
SIMILAR TO LAST FRIDAY AT THE SURFACE...VERY LIGHT/VARIABLE
BREEZES IN THE EVENING WILL GRADUALLY GIVE WAY TO LIGHT SOUTHEAST
BREEZES LATER IN THE NIGHT AS THE SURFACE RIDGE AXIS DRIFTS
EASTWARD ACROSS THE CWA. HOWEVER...COMPARED TO 24 HOURS AGO IT NOW
APPEARS THAT DEWPOINTS WILL NOT DROP OFF QUITE AS FAR...AND THUS
GUIDANCE/MODELS HAVE TRENDED A FEW DEGREES MILDER FOR OVERNIGHT
LOWS. AS A RESULT...NUDGED UP LOWS 1-2 DEGREES MOST AREAS VERSUS
PREVIOUS...AIMING MOST OF THE CWA BETWEEN 50-53...BUT WITH
PREDOMINANTLY MID-UPPER 40S IN A FEW OF THE FAR WESTERN
NORTHERN/COUNTIES. DESPITE THE LIGHT OVERNIGHT BREEZES...AM NOT
EXPECTING IMPACTFUL FOG TO BE AN ISSUE...ALTHOUGH SOME VERY LIGHT
FOG/HAZE IS PROBABLY NOT OUT OF THE QUESTION...BUT IS ALSO NOT
WORTH ADVERTISING IN THE FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM CDT TUE SEP 24 2013
PATTERN: THE CPC OBSERVED H5 HGT ANOMALY TOOLS SHOW THAT THE LOW
FREQUENCY /LGWV/ FLOW OF THE PAST 90 DAYS LARGELY REMAINS IN PLACE
OVER THE NRN HEMISPHERE. HOWEVER...WE HAVE RECENTLY SEEN
AMPLIFICATION ESPECIALLY WITH THE ERN PAC TROF. OTHER ADJUSTMENTS
SHOW THAT THE +HGT ANOMALY WHICH HAS RESIDED OVER WRN N AMERICA HAS
SHIFT TO THE E...ALLOWING THE TEMPORARY ESTABLISHMENT OF A WRN N
AMERICA TROF. THIS TROF WILL ONLY BE WITH US THIS WEEK AND OFFERS
ONE MORE SHOT AT DECENT RAINFALL. THE NAO HAS TURNED SHARPLY
NEGATIVE AS THE PERSISTENT -HGT ANOMALY OVER GREENLAND HAS BEEN
REPLACED WITH +HGT ANOMALIES. THIS COMBINED WITH THE A PAIR OF
STORMS CROSSING THE NRN PAC WILL RETURN RIDGING TO WRN N AMERICA
THIS WEEKEND. SO THE BOTTOM LINE IS...EXCEPT FOR A BRIEF WINDOW THU
NGT-FRI...DRY WX WILL CONT. TEMPS WILL BE VARIABLE BUT PROBABLY
AVERAGE PRETTY CLOSE TO NORMAL OVER THE NEXT 10 DAYS.
ALOFT: SW FLOW WILL DEVELOP OVER THE CNTRL PLAINS WED AND CONT THRU
FRI...AS THE WRN USA TROF FULLY RELOADS. CYCLOGENESIS WILL OCCUR
THU...WITH THE MAIN UPR LOW HEADING N INTO CANADA. THE MAIN UPR TROF
WILL BE LEFT BEHIND AND BEGIN LIFTING NE...CROSSING THE CNTRL PLAINS
SAT. NW FLOW FOLLOWS SUN-MON BUT THERE IS DISAGREEMENT/UNCERTAINTY
IN THE AMPLITUDE OF THE RIDGE MOVING INTO THE W.
SFC: A PAC COLD FRONT WILL EXTEND FROM THE NRN ROCKIES TO CNTRL CA
WED...WITH A LEE-SIDE TROF IN PLACE. THIS FRONT WILL ADVANCE E AND
EMERGE ONTO THE PLAINS BY DAWN THU. HOWEVER...THE SRN PORTION WILL
REMAIN STATIONARY DUE TO MINIMAL MOVEMENT OF THE BASE OF THE TROF.
THE SLOW EJECTION OF THE TROF MEANS THE FWD PROGRESS OF THE FRONT
WILL BE SLOW. WRN USA HIGH PRES BUILDS IN SAT THRU MON.
WITH SW FLOW ALOFT ON BOTH SIDES OF THIS FRONT...IT WILL HAVE AN
ANABATIC CHARACTER. THE SLOW MOVEMENT OFFERS THE OPPORTUNITY FOR
ENTRAINMENT OF GULF MSTR. WE ARE SEEING A NARROW RIBBON OF MSTR FCST
TO SURGE NWD FRI...WITH PW NEARING 1.6".
HAZARDS: NOTHING SUBSTANTIAL...BUT THERE IS A LATE-WEEK THUNDER
THREAT. RISK OF SVR LOOKS VERY LOW.
THE DAILY DETAILS...
WED: WARM SECTOR. BREEZY AND WARMER BY 7-10F.
WED NGT: A STRONG LLJ WILL DEVELOP /55-60 KTS/ WITH LOW-LVL WINDS
VEERING TO THE SW. THIS WILL ADVECT AN EML ONTO THE PLAINS...
IMPOSING A SUBSTANTIAL CAP.
THU: WARM SECTOR. VERY WARM. ADD ANOTHER 3-7F TO WED AND THIS WILL
PUT HIGHS 10F ABOVE NORMAL. HIGHS IN THE LWR 90S LOOK LIKE A GOOD
BET OVER N-CNTRL KS.
THU NGT: SOME ISOLATED HIGH-BASED SHWRS/TSTMS ARE POSSIBLE. THIS
REALLY DEPENDS ON WHERE THE LLJ CORE SETS UP. THE EC IS FURTHER N
THAN THE GFS AND NAM. IF SHWRS/TSTMS DEVELOP RAINFALL AMTS WILL BE
VERY LIGHT.
FRI: WARM SECTOR...BUT THE FRONT THREATENS THE NW FRINGE OF THE FCST
AREA DURING PEAK HEATING. MOST OF THE FCST AREA SHOULD REMAIN DRY
FOR MOST OF THE DAY. PCPN AND CLOUDS WILL BE MOST EXTENSIVE BEHIND
THE FRONT WHICH SHOULD RESULT IN A SUBSTANTIAL TEMP CONTRAST ACROSS
THE STATE. AHEAD OF THE FRONT EXPECT THE ATMS TO BE CAPPED. SCT
TSTMS SHOULD ONLY ERUPT IN THE IMMEDIATE VICINITY OF THE FRONT IN
THE LATE AFTN.
SEVERE?: PROBABLY NOT BUT IF THERE IS A THREAT IS LOOKS VERY
MARGINAL DUE TO WEAK INSTABILITY. HOWEVER...STRENGTH OF THE WIND
FIELDS AND THE DRY SUB-CLOUD LAYER COULD SUPPORT SOME DECENT WINDS
IF A STRONGER STORM OR TWO CAN DEVELOP.
FRI NGT: COLD FRONTAL PASSAGE. THE SETUP LOOKS GOOD FOR SOME DECENT
POST-FRONTAL RAINFALL IN SOME LOCATIONS.
SAT: MUCH COOLER! PROBABLY 20F COOLER THAN FRI. IN FACT...WITH
THE UPR TROF MOVING THRU...BELIEVE FUTURE FCSTS WILL END UP LOWERING
HIGHS ANOTHER 5F OR SO. CONSENSUS OF 2M TEMPS CURRENTLY OFFERS 57F
AT ORD AND 67F AT BELOIT. NOT MUCH DIFF FROM THE 12Z/18Z CYCLES.
SWEATSHIRTS AND JACKETS MAY BE NEEDED FOR OUTDOOR ACTIVITIES.
CLOUDY TO START WITH A COUPLE LEFTOVER SHWRS OR SOME PATCHY DRZL.
CLEARING PROGRESSES FROM W TO E IN THE AFTN.
SUN-MON: BACK TO NICER WX. TEMPS REBOUND AND WITH LOW PRES MOVING
THRU THE CANADIAN ROCKIES...A LEE-SIDE TROF WILL DEVELOP AND MAY
ACTUALLY PROGRESS THRU THE FCST AREA WITH AN ATTENDANT THERMAL
RIDGE. HIGHS SHOULD BE BACK INTO THE LOW-MID 70S SUN AND UPR 70S-80
MON?
&&
.AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 700 AM CDT TUE SEP 24 2013
ALTHOUGH CONFIDENCE REMAINS HIGH IN VFR VISIBILITY THROUGH THE
NEXT 24 HOURS...CEILING TRENDS WILL CONTINUE TO BE A CHALLENGE
ESPECIALLY THROUGH THE FIRST 6 HOURS TODAY...AS THE LOCAL AREA IS
CURRENTLY A MIXED BAG OF CLEAR SKIES INTERSPERSED WITH PASSING
BATCHES OF LOW VFR...MVFR AND EVEN IFR LOW CLOUDS. BASED ON LATEST
OBS AND SATELLITE TRENDS...WENT AHEAD AND INTRODUCED PREVAILING
HIGHER MVFR CEILING THROUGH THE NEXT 6 HOURS...WITH A TEMPO GROUP
FOR LOWER MVFR CEILING FOR THE FIRST 4 HOURS. SOMETIME EARLY-MID
AFTERNOON...ANTICIPATE ANY LOW CEILINGS TO SCATTER OUT OR MOVE OFF
TO THE EAST....WITH FAIRLY HIGH CONFIDENCE IN NO WORSE THAN
CLEAR/MOSTLY CLEAR SKIES DURING AT LEAST THE FINAL 15 HOURS OF THE
PERIOD. AS FOR SURFACE WINDS...STEADY NORTHWEST BREEZES WILL
PERSIST THROUGH THE NEXT SEVERAL HOURS...WITH GUST POTENTIAL TO
AT LEAST 22KT OR HIGHER LASTING THROUGH MID-DAY BEFORE STEADILY
DIMINISHING DURING THE AFTERNOON...AND BECOMING LIGHT/VARIABLE
TONIGHT.
&&
.HYDROLOGY...
ISSUED AT 438 AM CDT TUE SEP 24 2013
OVERALL LITTLE CHANGE IN EXPECTATIONS OVERNIGHT REGARDING PLATTE
RIVER FLOODING/FLOODING POTENTIAL. WE CONTINUE TO ADVERTISE TWO
OFFICIAL FLOOD WARNINGS AT THIS TIME...ONE FOR THE RIVER GAGE NEAR
COZAD...WHICH COVERS THE PLATTE RIVER REACH ACROSS DAWSON COUNTY
INTO FAR WESTERN BUFFALO...AND A SECOND FOR THE GAGE NEAR
KEARNEY...WHICH COVERS THE REACH OF THE RIVER ALONG THE
BUFFALO/PHELPS/KEARNEY COUNTY LINE...AND THEN ACROSS THE MAJORITY
OF HALL COUNTY. ALTHOUGH THE LATEST MISSOURI BASIN RIVER FORECAST
CENTER (MBRFC) FORECAST TAKES THE GRAND ISLAND GAGE A FEW MILES
EAST OF TOWN BARELY INTO MINOR FLOOD STAGE WEDNESDAY NIGHT...WE
CONTINUE TO HOLD OFF ON A FORMAL FLOOD WARNING FOR THIS EASTERN
HALL COUNTY AREA AND POINTS EAST...MAINLY TO GIVE A BIT MORE TIME
TO FINE TUNE THE FORECAST BASED ON UPSTREAM BEHAVIOR AT THE COZAD
AND KEARNEY GAGES...AND ALSO THE OVERTON GAUGE WHICH IS NOT AN
OFFICIAL FORECAST POINT.
OVER THE PAST SEVERAL HOURS...THE GAGE ALONG THE NORTH CHANNEL AT
COZAD FINALLY REACHED MINOR FLOOD STAGE OF 6.5 FT AT 9 PM MONDAY
EVENING...AND HAS CONTINUED A STEADY CLIMB TO JUST OVER 7.2 FT AS OF
330 AM. AS A RESULT...THE CREST WHICH IS EXPECTED TO OCCUR
SOMETIME TODAY HAS BEEN NUDGED UPWARD TO 7.3 FT. THIS IS
ANTICIPATED TO BE A PROLONGED CREST WITH ONLY A VERY SLOW FALL TO
BELOW FLOOD STAGE BY SOMETIME FRIDAY. MEANWHILE...THE LATEST
OVERNIGHT TRENDS ON THE OVERTON AND KEARNEY GAGES CONTINUE TO
REFLECT VERY SLOW RISES...AND IT IS YET TO BE SEEN WHETHER THE
KEARNEY GAGE IN FACT CAN BREACH THE MINOR FLOOD STAGE OF 6.0 FT BY
LATE THIS MORNING AS THE LATEST FORECAST SUGGESTS. AT ANY RATE...A
CREST OF 7.2 FT CONTINUES TO BE FORECAST FOR KEARNEY ON
WEDNESDAY...AND AGAIN THIS WILL BE A PROLONGED CREST WITH A VERY
SLOW FALL...POSSIBLY REMAINING IN FLOOD STAGE THROUGH THE END OF
THE MONTH.
PLEASE NOTE ONLY MINOR FLOOD STAGE...AND NOT MODERATE/MAJOR
CATEGORIES...ARE ANTICIPATED ALONG THE AFOREMENTIONED FORECAST
POINTS WITHIN THE NWS HASTINGS CWA...AND THUS THE VAST MAJORITY OF
IMPACTS SHOULD REMAIN CONFINED TO THE IMMEDIATE LOWLAND AREAS
NEAR THE RIVER CHANNEL/S. THESE RIVER FORECASTS ARE UPDATED
REGULARLY PER COORDINATION BETWEEN MBRFC AND NWS HASTINGS...AND
MINOR TWEAKS IN CREST HEIGHT AND TIMING REMAIN LIKELY OVER THE
COMING DAYS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...SAR
SHORT TERM...PFANNKUCH
LONG TERM...HALBLAUB
AVIATION...PFANNKUCH
HYDROLOGY...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
705 AM CDT TUE SEP 24 2013
.UPDATE...
ISSUED AT 700 AM CDT TUE SEP 24 2013
AS DISCUSSED IN GREATER DETAIL IN THE PRIMARY OVERNIGHT
DISCUSSION...LOW STRATUS TRENDS CONTINUE TO BE A HEADACHE.
ALTHOUGH A FEW CORRIDORS OF CLEARING REMAIN...MUCH OF THE CWA IS
NOW UNDER FAIRLY WIDESPREAD LOW CLOUDS...WITH THE HRRR SUGGESTING
THAT GENERALLY THE EASTERN 3/4 OF THE CWA COULD REMAIN FAIRLY
SOCKED IN THROUGH MID-DAY. AS A RESULT...YET AGAIN BUMPED UP SKY
COVER PERCENTAGES AND SLOWED THE RATE OF WEST-TO-EAST
CLEARING...BUT STILL THINKING THAT MOST AREAS SHOULD AVERAGE NO
WORSE THAN PARTLY CLOUDY THROUGH THE BALANCE OF THE AFTERNOON.
WILL STAY THE COURSE WITH PREVIOUS HIGH TEMPS FOR NOW...AS ANY
CLEARING SHOULD RESULT IN A QUICK RISE AND HELP OFFSET ANY POTENTIAL
DELAY IN WARMING FROM MORNING CLOUD COVER. ON ONE FINAL
NOTE...RADAR TRENDS SUPPORTED KILLING THE SLIGHT POPS THAT
ORIGINALLY LINGERED IN A FEW FAR NORTHEAST COUNTIES THROUGH
15Z/10AM...SO NOW THE FORECAST IS OFFICIALLY VOID OF ALL PRECIP
MENTION UNTIL THURS NIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM CDT TUE SEP 24 2013
ALTHOUGH MOST IF NOT ALL OF THE CWA IS LOOKING AT A DRY AND FAIRLY
UNEVENTFUL UPCOMING 24 HOURS...ESPECIALLY THE DAYTIME HOURS HAVE
BECOME TRICKIER-THAN-EXPECTED MAINLY REGARDING THE EVOLUTION OF
SKY COVER/TEMPERATURES...AS LOW CLOUDS COULD BE STUBBORNLY SLOW TO
DEPART MAINLY WITHIN THE EASTERN 1/2 OF THE CWA...BRINGING 5+ DEGREE
TEMP BUST POTENTIAL VERY MUCH INTO PLAY.
08Z OBJECTIVE SURFACE ANALYSIS HIGHLIGHTS A SLOWLY-WEAKENING 1004
MILLIBAR LOW PRESSURE CENTER...CENTERED OVER THE CLAY/FILLMORE
COUNTY AREA...WHILE IN ITS WAKE THE LEADING EDGES OF HIGH PRESSURE
AROUND 1016MB HAS WORKED INTO THE NEB PANHANDLE. WITH THE MAJORITY
OF THE CWA POSITIONED BEHIND THE DEPARTING LOW...EARLY MORNING
BREEZES ARE MAINLY FROM THE WEST-NORTHWEST...WITH THE STRONGEST
SPEEDS WITH GUSTS OF 20+ MPH FOCUSED ACROSS THE SOUTHWESTERN HALF
OF THE AREA...WITH LIGHTER SPEEDS STILL HOLDING ON FOR AT LEAST A
FEW MORE HOURS WITHIN MUCH OF THE NORTHEAST 1/2. ALOFT...WATER
VAPOR IMAGERY AND SHORT TERM MODEL DATA CLEARLY REVEAL A WELL-
DEFINED...NOT QUITE VERTICALLY STACKED LOW PRESSURE SYSTEM
DEPARTING EASTWARD ACROSS THE EASTERN 1/4 OF NEB...WITH A CLOSED
500MB CIRCULATION CENTERED NEAR NORFOLK. AS A RESULT...THE PRIMARY
MID LEVEL CONVERGENCE/DEFORMATION ZONE AT THIS HOUR IS FOCUSING
WIDESPREAD MAINLY LIGHT RAIN 50+ MILES NORTHEAST OF THE
CWA. CLOUD-WISE...11-3.9 MICRON SATELLITE IMAGERY DEPICTS A
FAIRLY COMPLEX AND EVER-CHANGING MIXTURE OF CLEAR SKIES ALONG WITH
PASSING BATCHES OF MID CLOUDS AND LOW STRATUS. WHILE MOST OF THESE
LOWER CEILINGS WITHIN THE CWA ARE AT/ABOVE 1500 FT...A CORRIDOR OF
LOWER CEILINGS BETWEEN 500-1000 FT SEEMS TO BE LURKING JUST
NORTHWEST OF THE CWA ALONG A BROKEN BOW-AINSWORTH AXIS...WITH
THESE LOW CLOUDS POSSIBLY EVEN SUPPORTING SOME PATCHY LIGHT
DRIZZLE. TEMP-WISE...MOST OF THE CWA APPEARS HEADED FOR OVERNIGHT
LOWS IN THE MID 50S...WITH ANY LOW 50S/UPPER 40S MOST FAVORED IN
FAR WESTERN COUNTIES.
AS THE EARLY MORNING/DAYTIME HOURS WEAR ON...THE BIG PICTURE ALOFT
INVOLVES THE MID LEVEL SHORTWAVE TROUGH/ASSOCIATED CLOSED LOW
CONTINUING ITS STEADY TREK EASTWARD...WITH THE 500MB CIRCULATION
CENTER INTO SOUTHWEST IA BY 18Z...AND THEN OVER NORTH CENTRAL MO
BY 00Z/7PM. AS THIS LOW DEPARTS...A BROAD AREA OF SHORTWAVE
RIDGING AND ASSOCIATED HEIGHT RISES WILL OVERSPREAD THE CENTRAL
PLAINS. AT THE SURFACE...THE LOW PRESSURE CENTER CURRENTLY OVER
SOUTHEAST NEB WILL CONTINUE TO WEAKEN AS IT SLIDES INTO CENTRAL MO
OVER THE COURSE OF THE DAY...ALLOWING A MODEST RIDGE AXIS TO BUILD
INTO THE LOCAL AREA WITH TIME AND RELAX THE SURFACE PRESSURE
GRADIENT. HOWEVER...BREEZES WILL STILL BE FAIRLY ELEVATED FOR
MUCH OF THE DAY TODAY...LARGELY OWING TO MIXING CLIMBING UP TO
AROUND 850MB...WHERE AN ENHANCED CORRIDOR OF 30-40KT NORTHERLY
WINDS WILL LINGER THROUGH MID-DAY BEFORE STEADILY WEAKENING IN THE
AFTERNOON. THE NET RESULT WILL BE SUSTAINED NORTH-NORTHWEST WIND
SPEEDS 15-20 MPH WITH GUSTS 25+ MPH THROUGH THIS MORNING...BEFORE
DIMINISHING TO MORE SO SUSTAINED 10-15 MPH SPEEDS THIS
AFTERNOON...AND ONLY 5-10 MPH CLOSER TO SUNSET. AS FOR PRECIP
CHANCES...ALTHOUGH RADAR TRENDS AND SHORT TERM MODEL DATA
INCLUDING THE HRRR PRETTY STRONGLY SUGGEST THAN ANY RISK OF
MEASURABLE LIGHT RAIN SHOULD BE OVER BY 12Z...WENT AHEAD AND
LINGERED A TOKEN 20 POP IN THE EXTREME NORTHEAST
NANCE/MERRICK/POLK AREA THROUGH 15Z IN CASE SOMETHING MANAGES TO
STILL WRAP AROUND THE BACK SIDE OF THE LOW. THE BIG CHALLENGE
TODAY SEEMS TO BE CENTERED AROUND SKY COVER. 24 HOURS AGO...IT WAS
ASSUMED THAT MID LEVEL CLOUDS WOULD QUICKLY MOVE OFF EAST OF THE
CWA TODAY WITH THE PARENT SYSTEM. HOWEVER...LATEST SATELLITE AND
SHORT TERM MODEL DATA INCLUDING THE HRRR LOW CLOUD PRODUCT NOW
SUGGEST THAT THE AREAL COVERAGE OF LOW STRATUS MAY IN FACT
INCREASE BEFORE SUNRISE FROM THE NORTHWEST...AND THEN POSSIBLY
HANG VERY STUBBORNLY MAINLY ACROSS THE CENTRAL/EASTERN CWA EVEN
INTO THE AFTERNOON HOURS. ALTHOUGH HAVE NOT BOUGHT FULL-BORE INTO
THE VERY PESSIMISTIC RUC/HRRR SOLUTIONS REGARDING LOW CLOUDS
TODAY...DID INCREASE SKY COVER PERCENTAGES VERSUS PREVIOUS...AND
ALSO DELAYED THE WEST-EAST CLEARING TREND. HOWEVER...PLEASE NOTE
THAT ESPECIALLY EASTERN COUNTIES ALONG/NEAR HIGHWAY 81 MAY REALLY
STRUGGLE TO SEE MUCH SUN UNTIL MAYBE LATE AFTERNOON...AND DAY
SHIFT MAY HAVE TO MAKE SOME PRETTY NOTICEABLE ADJUSTMENTS TO SKY
COVER AND RESULTANT HIGH TEMPS. FOR NOW THOUGH...OPTED TO ONLY
SHAVE 1-2 DEGREES OFF PREVIOUS HIGHS IN MOST AREAS...RANGING FROM
LOW 70S FAR EAST TO UPPER 70S FAR SOUTHWEST...AND AROUND 73 TRI-
CITIES. IF CLOUDS ARE SLOW TO DEPART HOWEVER...SOME EASTERN AREAS
MAY STRUGGLE TO LEAVE THE 60S. ON ONE FINAL DAYTIME
NOTE...ALTHOUGH HAVE DEWPOINTS DROPPING INTO THE LOW-MID 40S
ACROSS MUCH OF THE WESTERN CWA DURING THE AFTERNOON...THESE VALUES
ARE NOT QUITE AS LOW AS ANTICIPATED 24 HOURS AGO...AND THIS KEEPS
ANY AFTERNOON RELATIVE HUMIDITY VALUES AS LOW AS 25-30 PERCENT
CONFINED TO MAINLY JUST THE FURNAS COUNTY AREA.
FOR THE EVENING/NIGHT 00Z-12Z PERIOD...WILL RUN WITH THE
ASSUMPTION THAT EVEN IF LOW STRATUS LINGERS QUITE AWHILE INTO THE
AFTERNOON IN SOME AREAS...THAT IT SHOULD BE SAFELY EAST OF THE CWA
BY SUNSET...THUS RESULTING IN A CLEAR OVERNIGHT AREA-WIDE WITH
ESSENTIALLY ZERO RISK OF PRECIP. ON THE BIG PICTURE...THE HEART OF
THE AFOREMENTIONED MID/UPPER LEVEL SHORTWAVE RIDGE AXIS WILL PASS
DIRECTLY OVER THE CWA...VERY SIMILAR TO LAST FRIDAY NIGHT. ALSO
SIMILAR TO LAST FRIDAY AT THE SURFACE...VERY LIGHT/VARIABLE
BREEZES IN THE EVENING WILL GRADUALLY GIVE WAY TO LIGHT SOUTHEAST
BREEZES LATER IN THE NIGHT AS THE SURFACE RIDGE AXIS DRIFTS
EASTWARD ACROSS THE CWA. HOWEVER...COMPARED TO 24 HOURS AGO IT NOW
APPEARS THAT DEWPOINTS WILL NOT DROP OFF QUITE AS FAR...AND THUS
GUIDANCE/MODELS HAVE TRENDED A FEW DEGREES MILDER FOR OVERNIGHT
LOWS. AS A RESULT...NUDGED UP LOWS 1-2 DEGREES MOST AREAS VERSUS
PREVIOUS...AIMING MOST OF THE CWA BETWEEN 50-53...BUT WITH
PREDOMINANTLY MID-UPPER 40S IN A FEW OF THE FAR WESTERN
NORTHERN/COUNTIES. DESPITE THE LIGHT OVERNIGHT BREEZES...AM NOT
EXPECTING IMPACTFUL FOG TO BE AN ISSUE...ALTHOUGH SOME VERY LIGHT
FOG/HAZE IS PROBABLY NOT OUT OF THE QUESTION...BUT IS ALSO NOT
WORTH ADVERTISING IN THE FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM CDT TUE SEP 24 2013
PATTERN: THE CPC OBSERVED H5 HGT ANOMALY TOOLS SHOW THAT THE LOW
FREQUENCY /LGWV/ FLOW OF THE PAST 90 DAYS LARGELY REMAINS IN PLACE
OVER THE NRN HEMISPHERE. HOWEVER...WE HAVE RECENTLY SEEN
AMPLIFICATION ESPECIALLY WITH THE ERN PAC TROF. OTHER ADJUSTMENTS
SHOW THAT THE +HGT ANOMALY WHICH HAS RESIDED OVER WRN N AMERICA HAS
SHIFT TO THE E...ALLOWING THE TEMPORARY ESTABLISHMENT OF A WRN N
AMERICA TROF. THIS TROF WILL ONLY BE WITH US THIS WEEK AND OFFERS
ONE MORE SHOT AT DECENT RAINFALL. THE NAO HAS TURNED SHARPLY
NEGATIVE AS THE PERSISTENT -HGT ANOMALY OVER GREENLAND HAS BEEN
REPLACED WITH +HGT ANOMALIES. THIS COMBINED WITH THE A PAIR OF
STORMS CROSSING THE NRN PAC WILL RETURN RIDGING TO WRN N AMERICA
THIS WEEKEND. SO THE BOTTOM LINE IS...EXCEPT FOR A BRIEF WINDOW THU
NGT-FRI...DRY WX WILL CONT. TEMPS WILL BE VARIABLE BUT PROBABLY
AVERAGE PRETTY CLOSE TO NORMAL OVER THE NEXT 10 DAYS.
ALOFT: SW FLOW WILL DEVELOP OVER THE CNTRL PLAINS WED AND CONT THRU
FRI...AS THE WRN USA TROF FULLY RELOADS. CYCLOGENESIS WILL OCCUR
THU...WITH THE MAIN UPR LOW HEADING N INTO CANADA. THE MAIN UPR TROF
WILL BE LEFT BEHIND AND BEGIN LIFTING NE...CROSSING THE CNTRL PLAINS
SAT. NW FLOW FOLLOWS SUN-MON BUT THERE IS DISAGREEMENT/UNCERTAINTY
IN THE AMPLITUDE OF THE RIDGE MOVING INTO THE W.
SFC: A PAC COLD FRONT WILL EXTEND FROM THE NRN ROCKIES TO CNTRL CA
WED...WITH A LEE-SIDE TROF IN PLACE. THIS FRONT WILL ADVANCE E AND
EMERGE ONTO THE PLAINS BY DAWN THU. HOWEVER...THE SRN PORTION WILL
REMAIN STATIONARY DUE TO MINIMAL MOVEMENT OF THE BASE OF THE TROF.
THE SLOW EJECTION OF THE TROF MEANS THE FWD PROGRESS OF THE FRONT
WILL BE SLOW. WRN USA HIGH PRES BUILDS IN SAT THRU MON.
WITH SW FLOW ALOFT ON BOTH SIDES OF THIS FRONT...IT WILL HAVE AN
ANABATIC CHARACTER. THE SLOW MOVEMENT OFFERS THE OPPORTUNITY FOR
ENTRAINMENT OF GULF MSTR. WE ARE SEEING A NARROW RIBBON OF MSTR FCST
TO SURGE NWD FRI...WITH PW NEARING 1.6".
HAZARDS: NOTHING SUBSTANTIAL...BUT THERE IS A LATE-WEEK THUNDER
THREAT. RISK OF SVR LOOKS VERY LOW.
THE DAILY DETAILS...
WED: WARM SECTOR. BREEZY AND WARMER BY 7-10F.
WED NGT: A STRONG LLJ WILL DEVELOP /55-60 KTS/ WITH LOW-LVL WINDS
VEERING TO THE SW. THIS WILL ADVECT AN EML ONTO THE PLAINS...
IMPOSING A SUBSTANTIAL CAP.
THU: WARM SECTOR. VERY WARM. ADD ANOTHER 3-7F TO WED AND THIS WILL
PUT HIGHS 10F ABOVE NORMAL. HIGHS IN THE LWR 90S LOOK LIKE A GOOD
BET OVER N-CNTRL KS.
THU NGT: SOME ISOLATED HIGH-BASED SHWRS/TSTMS ARE POSSIBLE. THIS
REALLY DEPENDS ON WHERE THE LLJ CORE SETS UP. THE EC IS FURTHER N
THAN THE GFS AND NAM. IF SHWRS/TSTMS DEVELOP RAINFALL AMTS WILL BE
VERY LIGHT.
FRI: WARM SECTOR...BUT THE FRONT THREATENS THE NW FRINGE OF THE FCST
AREA DURING PEAK HEATING. MOST OF THE FCST AREA SHOULD REMAIN DRY
FOR MOST OF THE DAY. PCPN AND CLOUDS WILL BE MOST EXTENSIVE BEHIND
THE FRONT WHICH SHOULD RESULT IN A SUBSTANTIAL TEMP CONTRAST ACROSS
THE STATE. AHEAD OF THE FRONT EXPECT THE ATMS TO BE CAPPED. SCT
TSTMS SHOULD ONLY ERUPT IN THE IMMEDIATE VICINITY OF THE FRONT IN
THE LATE AFTN.
SEVERE?: PROBABLY NOT BUT IF THERE IS A THREAT IS LOOKS VERY
MARGINAL DUE TO WEAK INSTABILITY. HOWEVER...STRENGTH OF THE WIND
FIELDS AND THE DRY SUB-CLOUD LAYER COULD SUPPORT SOME DECENT WINDS
IF A STRONGER STORM OR TWO CAN DEVELOP.
FRI NGT: COLD FRONTAL PASSAGE. THE SETUP LOOKS GOOD FOR SOME DECENT
POST-FRONTAL RAINFALL IN SOME LOCATIONS.
SAT: MUCH COOLER! PROBABLY 20F COOLER THAN FRI. IN FACT...WITH
THE UPR TROF MOVING THRU...BELIEVE FUTURE FCSTS WILL END UP LOWERING
HIGHS ANOTHER 5F OR SO. CONSENSUS OF 2M TEMPS CURRENTLY OFFERS 57F
AT ORD AND 67F AT BELOIT. NOT MUCH DIFF FROM THE 12Z/18Z CYCLES.
SWEATSHIRTS AND JACKETS MAY BE NEEDED FOR OUTDOOR ACTIVITIES.
CLOUDY TO START WITH A COUPLE LEFTOVER SHWRS OR SOME PATCHY DRZL.
CLEARING PROGRESSES FROM W TO E IN THE AFTN.
SUN-MON: BACK TO NICER WX. TEMPS REBOUND AND WITH LOW PRES MOVING
THRU THE CANADIAN ROCKIES...A LEE-SIDE TROF WILL DEVELOP AND MAY
ACTUALLY PROGRESS THRU THE FCST AREA WITH AN ATTENDANT THERMAL
RIDGE. HIGHS SHOULD BE BACK INTO THE LOW-MID 70S SUN AND UPR 70S-80
MON?
&&
.AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 700 AM CDT TUE SEP 24 2013
ALTHOUGH CONFIDENCE REMAINS HIGH IN VFR VISIBILITY THROUGH THE
NEXT 24 HOURS...CEILING TRENDS WILL CONTINUE TO BE A CHALLENGE
ESPECIALLY THROUGH THE FIRST 6 HOURS TODAY...AS THE LOCAL AREA IS
CURRENTLY A MIXED BAG OF CLEAR SKIES INTERSPERSED WITH PASSING
BATCHES OF LOW VFR...MVFR AND EVEN IFR LOW CLOUDS. BASED ON LATEST
OBS AND SATELLITE TRENDS...WENT AHEAD AND INTRODUCED PREVAILING
HIGHER MVFR CEILING THROUGH THE NEXT 6 HOURS...WITH A TEMPO GROUP
FOR LOWER MVFR CEILING FOR THE FIRST 4 HOURS. SOMETIME EARLY-MID
AFTERNOON...ANTICIPATE ANY LOW CEILINGS TO SCATTER OUT OR MOVE OFF
TO THE EAST....WITH FAIRLY HIGH CONFIDENCE IN NO WORSE THAN
CLEAR/MOSTLY CLEAR SKIES DURING AT LEAST THE FINAL 15 HOURS OF THE
PERIOD. AS FOR SURFACE WINDS...STEADY NORTHWEST BREEZES WILL
PERSIST THROUGH THE NEXT SEVERAL HOURS...WITH GUST POTENTIAL TO
AT LEAST 22KT OR HIGHER LASTING THROUGH MID-DAY BEFORE STEADILY
DIMINISHING DURING THE AFTERNOON...AND BECOMING LIGHT/VARIABLE
TONIGHT.
&&
.HYDROLOGY...
ISSUED AT 438 AM CDT TUE SEP 24 2013
OVERALL LITTLE CHANGE IN EXPECTATIONS OVERNIGHT REGARDING PLATTE
RIVER FLOODING/FLOODING POTENTIAL. WE CONTINUE TO ADVERTISE TWO
OFFICIAL FLOOD WARNINGS AT THIS TIME...ONE FOR THE RIVER GAGE NEAR
COZAD...WHICH COVERS THE PLATTE RIVER REACH ACROSS DAWSON COUNTY
INTO FAR WESTERN BUFFALO...AND A SECOND FOR THE GAGE NEAR
KEARNEY...WHICH COVERS THE REACH OF THE RIVER ALONG THE
BUFFALO/PHELPS/KEARNEY COUNTY LINE...AND THEN ACROSS THE MAJORITY
OF HALL COUNTY. ALTHOUGH THE LATEST MISSOURI BASIN RIVER FORECAST
CENTER (MBRFC) FORECAST TAKES THE GRAND ISLAND GAGE A FEW MILES
EAST OF TOWN BARELY INTO MINOR FLOOD STAGE WEDNESDAY NIGHT...WE
CONTINUE TO HOLD OFF ON A FORMAL FLOOD WARNING FOR THIS EASTERN
HALL COUNTY AREA AND POINTS EAST...MAINLY TO GIVE A BIT MORE TIME
TO FINE TUNE THE FORECAST BASED ON UPSTREAM BEHAVIOR AT THE COZAD
AND KEARNEY GAGES...AND ALSO THE OVERTON GAUGE WHICH IS NOT AN
OFFICIAL FORECAST POINT.
OVER THE PAST SEVERAL HOURS...THE GAGE ALONG THE NORTH CHANNEL AT
COZAD FINALLY REACHED MINOR FLOOD STAGE OF 6.5 FT AT 9 PM MONDAY
EVENING...AND HAS CONTINUED A STEADY CLIMB TO JUST OVER 7.2 FT AS OF
330 AM. AS A RESULT...THE CREST WHICH IS EXPECTED TO OCCUR
SOMETIME TODAY HAS BEEN NUDGED UPWARD TO 7.3 FT. THIS IS
ANTICIPATED TO BE A PROLONGED CREST WITH ONLY A VERY SLOW FALL TO
BELOW FLOOD STAGE BY SOMETIME FRIDAY. MEANWHILE...THE LATEST
OVERNIGHT TRENDS ON THE OVERTON AND KEARNEY GAGES CONTINUE TO
REFLECT VERY SLOW RISES...AND IT IS YET TO BE SEEN WHETHER THE
KEARNEY GAGE IN FACT CAN BREACH THE MINOR FLOOD STAGE OF 6.0 FT BY
LATE THIS MORNING AS THE LATEST FORECAST SUGGESTS. AT ANY RATE...A
CREST OF 7.2 FT CONTINUES TO BE FORECAST FOR KEARNEY ON
WEDNESDAY...AND AGAIN THIS WILL BE A PROLONGED CREST WITH A VERY
SLOW FALL...POSSIBLY REMAINING IN FLOOD STAGE THROUGH THE END OF
THE MONTH.
PLEASE NOTE ONLY MINOR FLOOD STAGE...AND NOT MODERATE/MAJOR
CATEGORIES...ARE ANTICIPATED ALONG THE AFOREMENTIONED FORECAST
POINTS WITHIN THE NWS HASTINGS CWA...AND THUS THE VAST MAJORITY OF
IMPACTS SHOULD REMAIN CONFINED TO THE IMMEDIATE LOWLAND AREAS
NEAR THE RIVER CHANNEL/S. THESE RIVER FORECASTS ARE UPDATED
REGULARLY PER COORDINATION BETWEEN MBRFC AND NWS HASTINGS...AND
MINOR TWEAKS IN CREST HEIGHT AND TIMING REMAIN LIKELY OVER THE
COMING DAYS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...HALBLAUB
AVIATION...PFANNKUCH
HYDROLOGY...PFANNKUCH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
713 AM EDT TUE SEP 24 2013
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE SITTING OVER THE REGION WILL GRADUALLY
WEAKEN TODAY AND TONIGHT. A LOW PRESSURE SYSTEM WILL CROSS THE
SOUTHEAST STATES WEDNESDAY AND WEDNESDAY NIGHT... AS AN UPPER LEVEL
TROUGH TRACKS ACROSS THE CAROLINAS. HIGH PRESSURE WILL BUILD BACK
INTO THE REGION THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 225 AM TUESDAY...
FOR TODAY: RESIDUAL MOISTURE BENEATH THE SUBSIDENCE INVERSION ALOFT
AND MOIST ISENTROPIC UPGLIDE AROUND 295K HAS RESULTED IN AREALLY
EXPANDING STRATUS OVER CENTRAL/WRN VA AND WRN NC THIS MORNING...
QUICKLY SPREADING INTO THE NRN AND WRN PORTIONS OF THE FORECAST
AREA... WHICH WAS NOT DEPICTED WELL AT ALL BY THE NAM/GFS MODELS.
TRENDS SUPPORT A CONTINUED EXPANSION THROUGH DAYBREAK IN AREAS OVER
AND JUST EAST OF THE HIGHER TERRAIN... SO EXPECT PARTLY TO MOSTLY
CLOUDY SKIES FOR MOST AREAS ALONG AND NW OF I-85 IN THE NRN/NW CWA.
THE LATEST RUNS OF THE HRRR MODEL SHOW LOWER STRATUS FORMING OVER
NEARLY ALL OF CENTRAL NC DURING THE PREDAWN HOURS THIS MORNING...
MIXING OUT BY MID MORNING. HAVE EVIDENCE OF THIS DEVELOPMENT AS
YET... BUT BASED ON THE LACK OF WIND AND DEW POINTS STILL SITTING IN
THE 50-55 DEGREE RANGE... THIS IS CERTAINLY POSSIBLE. AT ANY RATE...
EXPECT AT LEAST PARTLY CLOUDY SKIES FOR MUCH OF THE CWA AROUND DAWN.
ONCE THESE CLOUDS MIX OUT WITH HEATING... WE SHOULD SEE MOSTLY SUNNY
SKIES TODAY WITH SCATTERED FLAT DIURNAL CUMULUS IN THE AFTERNOON.
SURFACE HIGH PRESSURE CENTERED OVER SRN ONTARIO/LAKE HURON WILL
WEAKEN TODAY BUT CONTINUE TO EXTEND SSE INTO CENTRAL/ERN NC...
ANCHORED DIRECTLY BENEATH STATIONARY BUT WEAKENING MID LEVEL
RIDGING. DESPITE THE CLOUDS THIS MORNING AND SCATTERED CLOUDS THIS
AFTERNOON... VERY DRY/STABLE AIR ALOFT AND NEUTRAL OR SUBSIDING
COLUMN WILL MAKE FOR A QUIET AND DRY DAY. LOW LEVEL THICKNESSES ARE
EXPECTED TO START THE DAY IN THE 1360-1365 M RANGE (AROUND 20 M
BELOW NORMAL)... RISING TO NEAR 1380 M... SUGGESTING HIGHS OF 75-80.
FOR TONIGHT: THE VORTEX NOW SPINNING OVER ERN NE/KS WILL CROSS THE
MID MISS VALLEY TONIGHT... BRINGING INCREASING (BUT STILL MODEST)
MID-UPPER LEVEL DIVERGENT FLOW INTO THE WRN CAROLINAS... WHILE AT
THE SURFACE... THE WEAKENING RIDGE STILL NOSES SOUTHWARD INTO THE
AREA. THE OCCLUDING SURFACE FRONTAL SYSTEM WILL PUSH THROUGH THE
LOWER MISS VALLEY INTO MS/AL LATE TONIGHT WHILE SECONDARY LOW
PRESSURE BEGINS TO DEEPEN JUST OFF JAX... ALONG THE EAST-WEST
FRONTAL ZONE. THE TIGHTENING MSLP GRADIENT SHOULD HOLD MOSTLY TO OUR
SOUTH... LEAVING A PERSISTENT LIGHT/VARIABLE SURFACE FLOW OVER NC.
WITH SURFACE DEW POINTS STEADILY RISING... EXPECT ANOTHER ROUND OF
PATCHY STRATUS AND FOG DEVELOPMENT OVERNIGHT. THIS ALONG WITH THE
INCREASING MID-HIGH CLOUDS SPREADING IN FROM THE WEST WILL RESULT IN
A TREND TO PARTLY CLOUDY SKIES... WITH MOSTLY CLOUDY IN THE WRN CWA
NEAR THE BETTER POOLING OF LOW LEVEL MOISTURE JUST EAST OF THE
HIGHER TERRAIN. WILL STAY WITH A DRY FORECAST GIVEN THE STILL-LOW PW
VALUES AND LACK OF FORCING FOR ASCENT. EXPECT LOWS FROM 49 NE TO 57
WEST... A BLEND OF STATISTICAL GUIDANCE. -GIH
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 310 AM TUESDAY...
THE MID LEVEL VORTEX IS EXPECTED TO UNDERCUT THE ONTARIO-TO-
MIDATLANTIC RIDGE ALOFT... MOVING FROM SRN IL ACROSS KY AND OVER
VA/NC THROUGH WED NIGHT... BRINGING WEAK MID LEVEL DPVA AND WEAK
UPPER DIVERGENCE OVER AREA. MEANWHILE... AT THE SURFACE... THE
OCCLUDED FRONTAL SYSTEM OVER THE LOWER MISS VALLEY EXTENDING SOUTH
OF LA WED MORNING WEAKENS AND FILLS AS IT SHIFTS SLOWLY EAST...
WHILE THE LOW OFF JAX ALONG THE FRONT CONTINUES TO STRENGTHEN AS IT
TOO DRIFTS EASTWARD. DURING ALL OF THIS... CENTRAL NC REMAINS
INFLUENCED PRIMARILY BY THE LOW LEVEL RIDGE NOSING IN FROM THE
NORTH... WITH A WEAK BUT STEADY FEED OF LOW LEVEL DRY AIR VIA THE
NORTHEAST FLOW. THE RIDGE AXIS DOES ADJUST WITH THE SURFACE FLOW
BACKING TO MORE NORTHERLY AS THE LOW DEEPENS OFF THE SOUTHEAST
COAST... BUT FORECAST SOUNDINGS INDICATE CONTINUED FAIRLY DRY AIR
THROUGHOUT THE LOWEST 8000 FT OF THE COLUMN. WE ARE LIKELY TO SEE
OVERCAST MID LEVEL CLOUDINESS THROUGHOUT THE DAY AND NIGHT... AND
THE DPVA ALONG WITH STEEPENING LAPSE RATES ABOVE THE 0C LEVEL MAY
RESULT IN CONSIDERABLE VIRGA WED AFTERNOON THROUGH THE NIGHT. BUT
APART FROM THE FAR WRN CWA WHERE UP-TERRAIN FLOW MAY ALLOW FOR
ENOUGH LOWER LEVEL MOISTENING TO SUPPORT PATCHY LIGHT RAIN... IT
LOOKS LIKE THE REMAINDER OF CENTRAL NC WILL HAVE TOO MUCH DRY AIR
BELOW 8000 FT TO SUPPORT ANYTHING MORE THAN A FEW SPRINKLES. WILL
NUDGE POPS DOWN AREAWIDE... WITH CHANCE POPS CONFINED TO THE FAR
WEST AND SW CWA... TRENDING TO SLIGHT OR NO POPS FROM THE TRIANGLE
NORTH AND EAST WITH LITTLE TO NO MEASURABLE RAIN EXPECTED. THE
CLOUDS WILL LOWER THE DIURNAL TEMP RANGE... AND EXPECT HIGHS IN THE
LOW-MID 70S (IN LINE WITH THICKNESSES ABOUT 10 M BELOW NORMAL) AND
LOWS 54-60. -GIH
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 315 AM TUESDAY...
A SHORTWAVE TROUGH AXIS PASSING OVERHEAD EARLY THURSDAY WILL LEAD TO
INCREASING SUBSIDENCE AND DRYING DURING THE DAY...WITH LINGERING
LIGHT PRECIP MOVING TO THE COAST. LACK OF SIGNIFICANT PRECIP SHOULD
LIMIT THE STRENGTHEN OF A COLD AIR DAMMING-LIKE AIRMASS NEAR THE
SURFACE...SO THERE SHOULD BE CLEARING FROM THE NORTH THURSDAY
AFTERNOON/EVENING...WITH THE BULK OF THE CLOUD COVER ATTRIBUTABLE TO
THE UPPER TROUGH. TEMPS ARE A LITTLE TRICKY GIVEN THAT INITIAL
CLOUD COVER IS SOMEWHAT DEPENDENT ON PRECIP WEDNESDAY/WEDNESDAY
NIGHT AND A NORTHEASTERLY WIND WILL PREVAIL. HOWEVER...WITH
CLEARING...GUIDANCE SUGGESTS MID/UPPER 70S ARE POSSIBLE
WITH HEATING. WILL KEEP HIGHS A LITTLE BELOW GUIDANCE IN THE 73-77
RANGE. LOWS THURSDAY NIGHT IN THE LOW TO MID 50S.
FRIDAY THROUGH MONDAY...
MODELS ARE IN GOOD AGREEMENT REGARDING THE LONGWAVE PATTERN THIS
WEEKEND...WITH A HIGHLY AMPLIFIED RIDGE WEST OF THE MOUNTAINS AND AN
UPPER TROUGH/LOW OFF THE EAST COAST. BETWEEN THESE FEATURES...DEEP
NORTH-NORTHEASTERLY FLOW WILL PREVAIL...WITH DEEPER MOISTURE TO STAY
OFFSHORE. THE ECMWF HAS TRENDED STRONGER WITH AN UPPER LOW FORECAST
TO DEVELOP WITHIN THE TROUGH FRIDAY AND DRIFT NORTH ALONG THE EAST
COAST BY SUNDAY/MONDAY. THE ASSOCIATED SURFACE LOW WOULD BRING
BETTER MOISTURE WESTWARD INTO THE COASTAL PLAIN MONDAY...WHILE A
COLD FRONT OVER THE MIDWEST SLOWLY APPROACHES NC FROM THE WEST.
HOWEVER...MODELS STILL KEEP NC DRY BETWEEN THESE FEATURES THROUGH
MONDAY. PERSISTENT COLD ADVECTION ASSOCIATED WITH THE NORTHEASTERLY
FLOW WILL 850MB TEMPS DOWN TO 7-8C...WITH LOW LEVEL THICKNESSES IN
THE 1360-1365M RANGE EACH MORNING. THESE PARAMETERS SUGGEST TEMPS A
CATEGORY BELOW NORMAL...WITH LOW TO MID 70S LIKELY SATURDAY AND
SUNDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 710 AM TUESDAY...
VFR THROUGH AT LEAST THIS EVENING. THE WIDESPREAD MORNING STRATUS
AFFECTING RWI/RDU/GSO/INT ARE EXPECTED TO MIX OUT AND BECOME
SCATTERED BY 15Z WITH THE ONSET OF HEATING. SCATTERED FLAT CUMULUS
BASED AROUND 4000 FT AGL IS EXPECTED THIS AFTERNOON... AS THE
MID/UPPER LEVELS STAY STABLE AND VERY DRY WHILE A THIN MOIST LAYER
PERSISTS BENEATH THE SUBSIDENCE INVERSION ALOFT. THEN AFTER
SUNSET... STABILIZING LOW LEVELS (LOWEST 4000 FT) AND VERY LIGHT
WINDS WITH INCREASING NEAR-SURFACE MOISTURE WILL BRING A RISK OF
MVFR FOG TONIGHT... ALTHOUGH THE BETTER CHANCE OF ADVERSE AVIATION
CONDITIONS WILL HOLD OFF UNTIL AFTER 06Z TONIGHT. HIGH CLOUDS BASED
ABOVE 15000 FT AGL WILL SPREAD IN FROM THE WEST TONIGHT. WINDS WILL
BE VARIABLE IN DIRECTION THROUGH THE PERIOD AT SPEEDS UNDER 7 KTS.
LOOKING BEYOND 12Z WEDNESDAY MORNING: PATCHY LOW STRATUS AND FOG ARE
POSSIBLE THROUGH MID MORNING... PARTICULARLY NEAR BODIES OF WATER
WHERE SHALLOW DENSE GROUND FOG MAY FORM PRIOR TO DAYBREAK. ANY SUCH
CLOUDS SHOULD MIX OUT BEFORE 15Z WITH VFR CONDITIONS RETURNING...
ALTHOUGH WE WILL SEE AN INCREASE IN STRATOCUMULUS BASED AROUND 3500
FT AGL ALONG WITH THICKENING AND LOWERING MID CLOUDS AS A STORM
SYSTEM APPROACHES WEDNESDAY. IN GENERAL... VFR CONDITIONS WILL
DOMINATE AS THIS SYSTEM CROSSES THE SOUTHEAST AND CAROLINAS... WITH
CLOUD BASES MOSTLY ABOVE 3500 FT WITH LIGHT SHOWERS. THIS SYSTEM
WILL EXIT ON THURSDAY WITH NEW HIGH PRESSURE RIDGING BUILDING IN AT
THE SURFACE. SHALLOW FOG IS POSSIBLE EARLY FRIDAY MORNING WITH HIGH
SURFACE RH AND LIGHT WINDS... BUT OTHERWISE EXPECT VFR CONDITIONS
FRIDAY THROUGH SATURDAY BENEATH THE HIGH PRESSURE RIDGE. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...22
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
947 AM CDT TUE SEP 24 2013
.UPDATE...
ISSUED AT 947 AM CDT TUE SEP 24 2013
FOG HAS DISSIPATED ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS
MORNING. AS A RESULT...REMOVED MORNING FOG WORDING FROM THE TEXT
PRODUCTS. OTHERWISE...SUNNY SKIES ARE EXPECTED TODAY WITH HIGHS
GENERALLY IN THE LOW 70S. THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 642 AM CDT TUE SEP 24 2013
LATEST SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE AREAS
OF FOG ALONG THE MISSOURI RIVER FROM BISMARCK SOUTH TO THE SOUTH
DAKOTA BORDER...AND EAST TOWARDS JAMESTOWN. ALSO AN AREA OF LOWER
CLOUDS NOTED NEAR THE TURTLE MOUNTAINS. WILL CONTINUE A MENTION
OF FOG FOR THESE AREAS THROUGH 15 UTC. OTHERWISE MAINLY CLEAR
SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA. SHOWERS THAT MOVED
THROUGH THE AREA LAST NIGHT HAVE ALL BUT EXITED THE FAR SOUTHEAST
CWA. UPDATED FORECAST LOWS WITH LATEST SENSIBLE WEATHER
OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CDT TUE SEP 24 2013
LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH WORKING ITS
WAY FROM CENTRAL NORTH DAKOTA INTO EASTERN NORTH DAKOTA. LOCAL
RADAR AHEAD OF THIS TROUGH CONTINUES TO SHOW SCATTERED LIGHT
SHOWERS FROM NEAR JAMESTOWN SOUTH TO ASHLEY AND EAST TO OAKES.
THIS AREA WILL WANE THROUGH 12Z AS THE UPPER TROUGH EXITS THE
COUNTY WARNING AREA. THE FOG/STRATUS LOOP INDICATES AN AREA OF
FOG/LOW CLOUDS IN ADAMS AND HETTINGER COUNTIES. THE HRRR CLOUD
CEILING HEIGHT IS ADVERTISING THIS AREA TO EXPAND SLIGHTLY AND
SLIDE SOUTHEAST...BARELY CLIPPING BISMARCK THROUGH 15Z. HAVE
FOLLOWED IT FOR THE SKY/WEATHER TRENDS EARLY THIS MORNING. OTHERWISE
WARM AIR ADVECTION COMMENCES TODAY THROUGH TONIGHT. LARGE SCALE
CONVERGENCE ALOFT WILL ALLOW FOR PLENTY OF SUNSHINE TODAY. WITH
WARM AIR ADVECTION INCREASING TUESDAY NIGHT...A CHANGE TOWARD
DIVERGENCE ALOFT ENSUES...ESPECIALLY OVER THE WEST/NORTHWEST. THE
FAR NORTHWEST IS SUSCEPTIBLE TO AN ISOLATED SHOWER/THUNDERSTORM IN
AFTER MIDNIGHT...OTHERWISE DRY WEATHER PREVAILS ELSEWHERE THROUGH
THE SHORT TERM PERIOD. H85 TEMPS BETWEEN +12C TO +16C WILL YIELD
AFTERNOON HIGHS IN THE UPPER 60S NORTH TO LOWER 70S SOUTH AND
WEST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 307 AM CDT TUE SEP 24 2013
THE MAIN FORECAST ISSUES IN THE LONG TERM WILL BE ASSOCIATED WITH
A STRONG UPPER LEVEL TROUGH THAT TAKES SHAPE OVER THE NORTHWEST
U.S. OVER THE NEXT 24 HOURS...AND TRACKS INTO THE NORTHERN HIGH
PLAINS BY THE END OF THE WORK WEEK. CURRENTLY...UPPER LEVEL
CIRCULATION CAN BE SEEN OFF THE BRITISH COLUMBIA COAST WITH A
STRONG SHORTWAVE TROUGH OVER THE EASTERN PACIFIC...OFF THE
NORTHERN CALIFORNIA COAST AND MATCHES WITH DETERMINISTIC MODELS.
THE STRONG SHORTWAVE TROUGH WILL BE THE FIRST TO INFLUENCE OUR
WEATHER AS IT MOVES ACROSS THE NORTHERN ROCKIES. STRONG SURFACE LOW
PRESSURE DEVELOPS OVER EASTERN MONTANA BY TUESDAY NIGHT WITH
INCREASING SOUTHERLY WINDS OVER WESTERN AND CENTRAL NORTH DAKOTA.
THIS WILL BRING A SMALL CHANCE OF THUNDERSTORMS TO THE FAR WEST AND
NORTHWEST DURING THE DAY ON WEDNESDAY. THUNDERSTORM CHANCES WILL
INCREASE WEDNESDAY NIGHT INTO THURSDAY AS THE SURFACE LOW SLOWS DOWN
AND TRACKS FROM WESTERN INTO CENTRAL NORTH DAKOTA DUE TO A STRONG
UPPER LEVEL JET ROUNDING THE BASE OF THE MAIN UPPER LEVEL LOW AS
IT MOVES INTO THE NORTHERN ROCKIES. INCREASING UPPER LEVEL JET
DYNAMICS ACROSS THE NORTHERN HIGH PLAINS COULD SUPPORT SCATTERED
SEVERE STORMS THAT WOULD THEN TRACK INTO THE WESTERN DAKOTAS.
THUNDERSTORMS ARE EXPECTED TO BECOME ELEVATED LATE WEDNESDAY NIGHT
INTO THURSDAY MORNING WITH A STRONG LOW LEVEL JET LIFTING INTO
CENTRAL NORTH DAKOTA. THE GREATEST THREAT FOR THUNDERSTORMS WILL
BE ACROSS FAR WESTERN AND NORTH CENTRAL NORTH DAKOTA WEDNESDAY
NIGHT THROUGH THURSDAY MORNING...ALTHOUGH WITH SUCH STRONG
DYNAMICS...SCATTERED THUNDERSTORMS CANNOT BE RULED OUT OVER
CENTRAL NORTH DAKOTA.
DETERMINISTIC MODELS ARE ALL DEPICTING A BREAK IN THE ACTION BEHIND
THE INITIAL STRONG SHORTWAVE THURSDAY AFTERNOON INTO THURSDAY
EVENING...BEFORE THE MAIN UPPER LEVEL LOW LIFTS INTO THE NORTHERN
PLAINS. PRECIPITATION CHANCES THEN INCREASE LATE THURSDAY NIGHT
THROUGH FRIDAY AS THE UPPER LEVEL TROUGH MOVES INTO THE NORTHERN
PLAINS. THERE ARE SOME DIFFERENCES IN QPF BETWEEN THE WETTER ECMWF
AND DRIER GFS/GEM ON FRIDAY. BY THIS TIME THE LOW LEVEL FLOW HAS
SHIFTED NORTH OVER ALL BUT THE FAR SOUTHEAST CWA AND PRECIPITATION
IS EXPECTED TO BE SHOWERS WITH PERHAPS AN ISOLATED THUNDERSTORM.
THUNDERSTORM CHANCES WILL REMAIN OVER THE FAR SOUTHEAST FRIDAY
NIGHT BEHIND THE SURFACE BOUNDARY AND JUST AHEAD OF THE UPPER
LEVEL TROUGH.
UPPER LEVEL RIDGING THEN BUILDS OVER THE REGION BRINGING DRY
CONDITIONS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
TEMPERATURES MAINLY IN THE 70S AHEAD OF THE MAIN COLD FRONT
WEDNESDAY WILL COOL INTO THE 50S AND 60S ACROSS THE AREA BY FRIDAY.
THEN A WARM-UP BACK INTO THE 70S IS EXPECTED BY SUNDAY AND MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 947 AM CDT TUE SEP 24 2013
VFR CIGS/VSBYS EXPECTED AT ALL AERODROMES FOR THE NEXT 24HR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...KS
LONG TERM...TWH
AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
642 AM CDT TUE SEP 24 2013
.UPDATE...
ISSUED AT 642 AM CDT TUE SEP 24 2013
LATEST SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE AREAS
OF FOG ALONG THE MISSOURI RIVER FROM BISMARCK SOUTH TO THE SOUTH
DAKOTA BORDER...AND EAST TOWARDS JAMESTOWN. ALSO AN AREA OF LOWER
CLOUDS NOTED NEAR THE TURTLE MOUNTAINS. WILL CONTINUE A MENTION
OF FOG FOR THESE AREAS THROUGH 15 UTC. OTHERWISE MAINLY CLEAR
SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA. SHOWERS THAT MOVED
THROUGH THE AREA LAST NIGHT HAVE ALL BUT EXITED THE FAR SOUTHEAST
CWA. UPDATED FORECAST LOWS WITH LATEST SENSIBLE WEATHER
OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CDT TUE SEP 24 2013
LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH WORKING ITS
WAY FROM CENTRAL NORTH DAKOTA INTO EASTERN NORTH DAKOTA. LOCAL
RADAR AHEAD OF THIS TROUGH CONTINUES TO SHOW SCATTERED LIGHT
SHOWERS FROM NEAR JAMESTOWN SOUTH TO ASHLEY AND EAST TO OAKES.
THIS AREA WILL WANE THROUGH 12Z AS THE UPPER TROUGH EXITS THE
COUNTY WARNING AREA. THE FOG/STRATUS LOOP INDICATES AN AREA OF
FOG/LOW CLOUDS IN ADAMS AND HETTINGER COUNTIES. THE HRRR CLOUD
CEILING HEIGHT IS ADVERTISING THIS AREA TO EXPAND SLIGHTLY AND
SLIDE SOUTHEAST...BARELY CLIPPING BISMARCK THROUGH 15Z. HAVE
FOLLOWED IT FOR THE SKY/WEATHER TRENDS EARLY THIS MORNING. OTHERWISE
WARM AIR ADVECTION COMMENCES TODAY THROUGH TONIGHT. LARGE SCALE
CONVERGENCE ALOFT WILL ALLOW FOR PLENTY OF SUNSHINE TODAY. WITH
WARM AIR ADVECTION INCREASING TUESDAY NIGHT...A CHANGE TOWARD
DIVERGENCE ALOFT ENSUES...ESPECIALLY OVER THE WEST/NORTHWEST. THE
FAR NORTHWEST IS SUSCEPTIBLE TO AN ISOLATED SHOWER/THUNDERSTORM IN
AFTER MIDNIGHT...OTHERWISE DRY WEATHER PREVAILS ELSEWHERE THROUGH
THE SHORT TERM PERIOD. H85 TEMPS BETWEEN +12C TO +16C WILL YIELD
AFTERNOON HIGHS IN THE UPPER 60S NORTH TO LOWER 70S SOUTH AND
WEST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 307 AM CDT TUE SEP 24 2013
THE MAIN FORECAST ISSUES IN THE LONG TERM WILL BE ASSOCIATED WITH
A STRONG UPPER LEVEL TROUGH THAT TAKES SHAPE OVER THE NORTHWEST
U.S. OVER THE NEXT 24 HOURS...AND TRACKS INTO THE NORTHERN HIGH
PLAINS BY THE END OF THE WORK WEEK. CURRENTLY...UPPER LEVEL
CIRCULATION CAN BE SEEN OFF THE BRITISH COLUMBIA COAST WITH A
STRONG SHORTWAVE TROUGH OVER THE EASTERN PACIFIC...OFF THE
NORTHERN CALIFORNIA COAST AND MATCHES WITH DETERMINISTIC MODELS.
THE STRONG SHORTWAVE TROUGH WILL BE THE FIRST TO INFLUENCE OUR
WEATHER AS IT MOVES ACROSS THE NORTHERN ROCKIES. STRONG SURFACE LOW
PRESSURE DEVELOPS OVER EASTERN MONTANA BY TUESDAY NIGHT WITH
INCREASING SOUTHERLY WINDS OVER WESTERN AND CENTRAL NORTH DAKOTA.
THIS WILL BRING A SMALL CHANCE OF THUNDERSTORMS TO THE FAR WEST AND
NORTHWEST DURING THE DAY ON WEDNESDAY. THUNDERSTORM CHANCES WILL
INCREASE WEDNESDAY NIGHT INTO THURSDAY AS THE SURFACE LOW SLOWS DOWN
AND TRACKS FROM WESTERN INTO CENTRAL NORTH DAKOTA DUE TO A STRONG
UPPER LEVEL JET ROUNDING THE BASE OF THE MAIN UPPER LEVEL LOW AS
IT MOVES INTO THE NORTHERN ROCKIES. INCREASING UPPER LEVEL JET
DYNAMICS ACROSS THE NORTHERN HIGH PLAINS COULD SUPPORT SCATTERED
SEVERE STORMS THAT WOULD THEN TRACK INTO THE WESTERN DAKOTAS.
THUNDERSTORMS ARE EXPECTED TO BECOME ELEVATED LATE WEDNESDAY NIGHT
INTO THURSDAY MORNING WITH A STRONG LOW LEVEL JET LIFTING INTO
CENTRAL NORTH DAKOTA. THE GREATEST THREAT FOR THUNDERSTORMS WILL
BE ACROSS FAR WESTERN AND NORTH CENTRAL NORTH DAKOTA WEDNESDAY
NIGHT THROUGH THURSDAY MORNING...ALTHOUGH WITH SUCH STRONG
DYNAMICS...SCATTERED THUNDERSTORMS CANNOT BE RULED OUT OVER
CENTRAL NORTH DAKOTA.
DETERMINISTIC MODELS ARE ALL DEPICTING A BREAK IN THE ACTION BEHIND
THE INITIAL STRONG SHORTWAVE THURSDAY AFTERNOON INTO THURSDAY
EVENING...BEFORE THE MAIN UPPER LEVEL LOW LIFTS INTO THE NORTHERN
PLAINS. PRECIPITATION CHANCES THEN INCREASE LATE THURSDAY NIGHT
THROUGH FRIDAY AS THE UPPER LEVEL TROUGH MOVES INTO THE NORTHERN
PLAINS. THERE ARE SOME DIFFERENCES IN QPF BETWEEN THE WETTER ECMWF
AND DRIER GFS/GEM ON FRIDAY. BY THIS TIME THE LOW LEVEL FLOW HAS
SHIFTED NORTH OVER ALL BUT THE FAR SOUTHEAST CWA AND PRECIPITATION
IS EXPECTED TO BE SHOWERS WITH PERHAPS AN ISOLATED THUNDERSTORM.
THUNDERSTORM CHANCES WILL REMAIN OVER THE FAR SOUTHEAST FRIDAY
NIGHT BEHIND THE SURFACE BOUNDARY AND JUST AHEAD OF THE UPPER
LEVEL TROUGH.
UPPER LEVEL RIDGING THEN BUILDS OVER THE REGION BRINGING DRY
CONDITIONS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
TEMPERATURES MAINLY IN THE 70S AHEAD OF THE MAIN COLD FRONT
WEDNESDAY WILL COOL INTO THE 50S AND 60S ACROSS THE AREA BY FRIDAY.
THEN A WARM-UP BACK INTO THE 70S IS EXPECTED BY SUNDAY AND MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 642 AM CDT TUE SEP 24 2013
AREAS OF FOG STRETCH FROM KBIS TO AROUND KJMS. ALTHOUGH VSBYS RANGE
BETWEEN LIFR/VLIFR...THE DEPTH OF THE FOG REMAINS SHALLOW. EXPECT A
QUICK RETURN TO SKC/P6SM BY 15Z. OTHERWISE VFR CIGS/VSBYS EXPECTED
AT ALL AERODROMES FOR THE NEXT 24HR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...KS
LONG TERM...TWH
AVIATION...KS
AREA FORECAST DISCUSSION
NWS SPOKANE WA
510 AM PDT Tue Sep 24 2013
.SYNOPSIS...
An upper level low will be the dominant weather feature through
much of the week. this will result in rain showers and mountain
snow showers at times through Thursday. Temperatures are expected
to remain well below normal. A warming and drying trend is
expected by the weekend.
&&
.DISCUSSION...
Morning update sent to fine tune Pops and QPF across the forecast
area. Steady stream of showers/rain has setup where
expected...generally from Pendleton to Pullman/Lewiston to Mullan.
Main updates to these areas was to increase QPF amts with some
heavier embedded cells producing 0.05" or more per hour.
Satellite and radar indicate showers filling across the Spokane-
CDA area and even as far northwest as Grand Coulee. Water Vapor
and model data confirm a weak shortwave embedded within the SW
flow and latest HRRR is handling the current situation. This would
suggest showers will continue to fill in across NE WA and Nrn ID
this morning impacting most communities from Republic to Bonners
Ferry. This activity is more scattered in nature so not every
point is a sure bet for rainfall. These showers are moving at a
good rate so most precipitation amts will be less then 0.05".
One other item of note via the latest HRRR is how convective
showers trend after 20z across the entire region. As the trof
settles into the region and 500mb cool...isolated showers will be
possible for just about every location and we have increased even
the lee of the Cascades to slight chance given the lack of a
strong rain shadow. This will need to be monitored closely across
the far southeast as any sunshine could deliver a few hundred
joules of CAPE and potential for isolated storms producing heavy
rainfall. /sb
&&
.AVIATION...
12Z TAFS: Wdsprd -shra and -ra will impact southeastern WA and the
the ID Panhandle through 00z with the most persistent band of pcpn
btwn KPUW and KLWS. MVFR cigs are anticipated under this band. Aft
20z...a cool upper-level trof sags into the region steepening
midlevel lapse rates and renewing the threat for showers just about
everywhere. A drying trend is expected to commence aft 06z along
the immediate Canadian Border and migrate south as drier...northerly
winds materialize. /sb
&&
.PREV DISCUSSION... /ISSUED 435 AM PDT Tue Sep 24 2013/
SYNOPSIS...
An upper level low will be the dominant weather feature through
much of the week. this will result in rain showers and mountain
snow showers at times through Thursday. Temperatures are expected
to remain well below normal. A warming and drying trend is
expected by the weekend.
DISCUSSION...
Tuesday and Tuesday night: A deep trof of low pressure will
carve into the Pac NW bringing a continuation of below normal
temperatures and unsettled weather. The most persistent area of
precipitation will focus across far southeastern WA and the lower
ID Panhandle however showers will be common across all mountains
surrounding the deep Basin and expanding at times into the West
Plains.
As of 2AM...a line of showers has developed from Mullan to
Pullman/Lewiston to Pendleton very close to where model guidance
indicated over the last 48 hours. Rainfall rates under this band
have generally be around 0.01 to 0.04" per hour. Expect this band
to sit in place until late Tuesday afternoon/early evening with
rainfall amounts spanning from a quarter to half an inch. Locally
higher amounts could be possible over the Camas Prairie;
especially if a few sun-breaks on Tuesday aftn add a convective
element.
Further north into the northeastern mountains of WA...Nrn ID
Panhandle...and Spokane-CDA area...a combination of afternoon
heating...orographics...and especially a shortwave passage during
the afternoon will also bring the threat for widely scattered
showers. This should be a bit more widespread and wetter then
Tuesday given the potential shortwave dynamics and PoPs may need
to be further increased for locations like Spokane...Deer Park...
Coeur D Alene...Sandpoint...and Bonners Ferry. Will be taking a
look at incoming HRRR runs and 12z guidance before deciding.
By this evening and overnight...the upper-level trof will become
firmly entrenched over the Pac NW. Cooling 500mb temperatures
near -25C will promote steepening midlevel lapse rates. A pressure
trof at the surface will begin to weaken and sag south and a cool
high pressure cell slipping into BC will create northerly
gradients across the CWA. This will draw cooler but drier air
southward into the CWA leading to a decreasing shower trend and
potential for locally gusty winds through the Okanogan Valley. A
few of the northern valleys like Republic...Deer Park...and Priest
Lake will be close to the freezing mark while most other lowlands
dip into the upper 30`s to mid 40`s. /sb
Wednesday and Wednesday Night: A closed low continues to pass to
the south of our forecast area but will still present some
unsettled conditions. Best chances for precipitation look to be
Tomorrow Afternoon in the ID Panhandle pushing back west into the
Blue Mtns. Rain showers will be the most likely mode of
precipitation...but a couple claps of thunder cannot be ruled out
with some weak instability in the Panhandle associated with the
trof and closed low. Precip amounts look to be pretty limited with
this system...but convective enhanced showers could bring moderate
showers for localized areas. By Wednesday Night the trof will be
pushing to the east limiting the overall chance for precipitation
in our forecast area.
Winds will be the main factor during this period with gusty
conditions expected Wednesday for the Okanogan Valley. Winds from
the north will channel down the valley enhancing the winds with
gusts in the range of 25 to 30mph. The gusty conditions will continue
down into the western Basin with values more in the 20 to 25mph
range. The winds will be something to monitor throughout the day
for the north-south oriented valleys in north Washington. Temperatures with
the northerly flow will be below normal with upper 50s and low 60s
for most locations minus the deep basin and lower valleys.
Overnight lows will be in the 30s and low 40s for most of the region.
Patchy frost was added for Wednesday Night as cold conditions will
continue into the overnight hours. Main focus for frost will be
the Republic area along with the Priest Lake and Deer Park areas. Fog
will also be present in some valley locations. Any areas with fog
will likely not see the frost as the fog will prevent strong
radiational cooling. Snow levels will remain lower allowing high
elevations in the Cascades and ID Panhandle to see some
flurries...but no lasting accumulations are expected. /Fliehman
Thursday through Monday...Model agreement is good and consistent
Thursday through Saturday. The deep trough over the region will
move off to the east on Thursday but some lingering shower
activity will continue primarily over the Idaho Panhandle and
possibly far eastern Washington. Temperatures will continue to run
below normal and locally breezy north winds especially down the
Okanogan and Purcell trenches will make for a somewhat raw day.
hings are looking up for the end of the week as the trough kicks
east into Montana and makes way for a weak but perceptible upper
level ridge to build over the region for Friday and Saturday. The
polar storm track will remain close by to the north during this
period...so while generally dry conditions are expected with
warming temperatures (up to about normal by Saturday) at least
partly cloudy conditions and a remote threat of some northern
mountain showers will prevail.
Beyond Saturday models begin to diverge and the moderate to high
confidence of the Thursday through Saturday period degrades to
low to moderate confidence in the far reaches of the extended
forecast. The ECMWF is much more aggressive about building a ridge
which implied dry and progressively warmer conditions through the
beginning of the next work week...while the GFS maintains a flat
and weaker ridge subject to flattening by weak transient
disturbances implying significant clouds and a small threat of
showers particularly on Sunday night and Monday with continued
seasonably normal temperatures. In any event it does appear that
models are in agreement that there will be no significant or
organized storm systems through early next week...and in this
regime it is a safe bet that the basin will remain dry while any
threat of showers remains confined to the northern mountains and
Cascades. /Fugazzi
AVIATION...
12Z TAFS: Wdsprd -shra and -ra will impact southeastern WA and the
the ID Panhandle through 00z with the most persistent band of pcpn
btwn KPUW and KLWS. MVFR cigs are anticipated under this band. Aft
20z...a cool upper-level trof sags into the region steepening
midlevel lapse rates and renewing the threat for showers just about
everywhere. A drying trend is expected to commence aft 06z along
the immediate Canadian Border and migrate south as drier...northerly
winds materialize. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 59 40 59 42 63 43 / 70 20 20 10 10 10
Coeur d`Alene 56 40 57 41 62 41 / 80 30 30 10 10 10
Pullman 54 39 57 39 62 39 / 100 40 30 20 10 10
Lewiston 59 47 62 48 67 45 / 100 50 40 30 10 10
Colville 62 40 64 40 67 39 / 40 30 20 10 10 10
Sandpoint 53 36 56 36 60 35 / 70 40 30 10 10 10
Kellogg 50 39 54 39 57 39 / 90 50 30 30 20 10
Moses Lake 65 40 67 42 69 43 / 20 20 10 0 0 0
Wenatchee 64 45 66 45 68 47 / 20 20 30 0 0 0
Omak 64 39 67 40 68 42 / 20 20 10 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
435 AM PDT Tue Sep 24 2013
.SYNOPSIS...
An upper level low will be the dominant weather feature through
much of the week. this will result in rain showers and mountain
snow showers at times through Thursday. Temperatures are expected
to remain well below normal. A warming and drying trend is
expected by the weekend.
&&
.DISCUSSION...
Tuesday and Tuesday night: A deep trof of low pressure will
carve into the Pac NW bringing a continuation of below normal
temperatures and unsettled weather. The most persistent area of
precipitation will focus across far southeastern WA and the lower
ID Panhandle however showers will be common across all mountains
surrounding the deep Basin and expanding at times into the West
Plains.
As of 2AM...a line of showers has developed from Mullan to
Pullman/Lewiston to Pendleton very close to where model guidance
indicated over the last 48 hours. Rainfall rates under this band
have generally be around 0.01 to 0.04" per hour. Expect this band
to sit in place until late Tuesday afternoon/early evening with
rainfall amounts spanning from a quarter to half an inch. Locally
higher amounts could be possible over the Camas Prairie;
especially if a few sun-breaks on Tuesday aftn add a convective
element.
Further north into the northeastern mountains of WA...Nrn ID
Panhandle...and Spokane-CDA area...a combination of afternoon
heating...orographics...and especially a shortwave passage during
the afternoon will also bring the threat for widely scattered
showers. This should be a bit more widespread and wetter then
Tuesday given the potential shortwave dynamics and PoPs may need
to be further increased for locations like Spokane...Deer Park...
Coeur D Alene...Sandpoint...and Bonners Ferry. Will be taking a
look at incoming HRRR runs and 12z guidance before deciding.
By this evening and overnight...the upper-level trof will become
firmly entrenched over the Pac NW. Cooling 500mb temperatures
near -25C will promote steepening midlevel lapse rates. A pressure
trof at the surface will begin to weaken and sag south and a cool
high pressure cell slipping into BC will create northerly
gradients across the CWA. This will draw cooler but drier air
southward into the CWA leading to a decreasing shower trend and
potential for locally gusty winds through the Okanogan Valley. A
few of the northern valleys like Republic...Deer Park...and Priest
Lake will be close to the freezing mark while most other lowlands
dip into the upper 30`s to mid 40`s. /sb
Wednesday and Wednesday Night: A closed low continues to pass to
the south of our forecast area but will still present some
unsettled conditions. Best chances for precipitation look to be
Tomorrow Afternoon in the ID Panhandle pushing back west into the
Blue Mtns. Rain showers will be the most likely mode of
precipitation...but a couple claps of thunder cannot be ruled out
with some weak instability in the Panhandle associated with the
trof and closed low. Precip amounts look to be pretty limited with
this system...but convective enhanced showers could bring moderate
showers for localized areas. By Wednesday Night the trof will be
pushing to the east limiting the overall chance for precipitation
in our forecast area.
Winds will be the main factor during this period with gusty
conditions expected Wednesday for the Okanogan Valley. Winds from
the north will channel down the valley enhancing the winds with
gusts in the range of 25 to 30mph. The gusty conditions will continue
down into the western Basin with values more in the 20 to 25mph
range. The winds will be something to monitor throughout the day
for the north-south oriented valleys in north Washington. Temperatures with
the northerly flow will be below normal with upper 50s and low 60s
for most locations minus the deep basin and lower valleys.
Overnight lows will be in the 30s and low 40s for most of the region.
Patchy frost was added for Wednesday Night as cold conditions will
continue into the overnight hours. Main focus for frost will be
the Republic area along with the Priest Lake and Deer Park areas. Fog
will also be present in some valley locations. Any areas with fog
will likely not see the frost as the fog will prevent strong
radiational cooling. Snow levels will remain lower allowing high
elevations in the Cascades and ID Panhandle to see some
flurries...but no lasting accumulations are expected. /Fliehman
Thursday through Monday...Model agreement is good and consistent
Thursday through Saturday. The deep trough over the region will
move off to the east on Thursday but some lingering shower
activity will continue primarily over the Idaho Panhandle and
possibly far eastern Washington. Temperatures will continue to run
below normal and locally breezy north winds especially down the
Okanogan and Purcell trenches will make for a somewhat raw day.
hings are looking up for the end of the week as the trough kicks
east into Montana and makes way for a weak but perceptible upper
level ridge to build over the region for Friday and Saturday. The
polar storm track will remain close by to the north during this
period...so while generally dry conditions are expected with
warming temperatures (up to about normal by Saturday) at least
partly cloudy conditions and a remote threat of some northern
mountain showers will prevail.
Beyond Saturday models begin to diverge and the moderate to high
confidence of the Thursday through Saturday period degrades to
low to moderate confidence in the far reaches of the extended
forecast. The ECMWF is much more aggressive about building a ridge
which implied dry and progressively warmer conditions through the
beginning of the next work week...while the GFS maintains a flat
and weaker ridge subject to flattening by weak transient
disturbances implying significant clouds and a small threat of
showers particularly on Sunday night and Monday with continued
seasonably normal temperatures. In any event it does appear that
models are in agreement that there will be no significant or
organized storm systems through early next week...and in this
regime it is a safe bet that the basin will remain dry while any
threat of showers remains confined to the northern mountains and
Cascades. /Fugazzi
&&
.AVIATION...
12Z TAFS: Wdsprd -shra and -ra will impact southeastern WA and the
the ID Panhandle through 00z with the most persistent band of pcpn
btwn KPUW and KLWS. MVFR cigs are anticipated under this band. Aft
20z...a cool upper-level trof sags into the region steepening
midlevel lapse rates and renewing the threat for showers just about
everywhere. A drying trend is expected to commence aft 06z along
the immediate Canadian Border and migrate south as drier...northerly
winds materialize. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 59 40 59 42 63 43 / 20 20 20 10 10 10
Coeur d`Alene 56 40 57 41 62 41 / 30 30 30 10 10 10
Pullman 54 39 57 39 62 39 / 70 40 30 20 10 10
Lewiston 59 47 62 48 67 45 / 90 50 40 30 10 10
Colville 62 40 64 40 67 39 / 20 30 20 10 10 10
Sandpoint 53 36 56 36 60 35 / 40 40 30 10 10 10
Kellogg 50 39 54 39 57 39 / 80 50 30 30 20 10
Moses Lake 65 40 67 42 69 43 / 10 20 10 0 0 0
Wenatchee 64 45 66 45 68 47 / 10 20 30 0 0 0
Omak 64 39 67 40 68 42 / 10 20 10 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1252 PM EDT TUE SEP 24 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 313 AM EDT TUE SEP 24 2013
AN UPPER LEVEL LOW ACCOMPANIED BY A SURFACE LOW WILL MOVE THROUGH
THE OHIO VALLEY TONIGHT AND WEDNESDAY BRINGING A CHANCE FOR RAIN TO
THE AREA. HIGH PRESSURE AND DRY CONDITIONS WILL THEN PERSIST THROUGH
THE FIRST HALF OF THE WEEKEND...UNTIL A COLD FRONT BRINGS ANOTHER
CHANCE FOR RAIN SATURDAY NIGHT INTO SUNDAY NIGHT. ABOVE AVERAGE
TEMPERATURES WILL GIVE WAY TO NEAR AVERAGE READINGS BY SUNDAY.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 956 AM EDT TUE SEP 24 2013
.UPDATE...
CURRENT FORECAST IS ON TRACK AND NO UPDATES ARE PLANNED AT THIS TIME.
ONLY CHANGE TO THE GRIDS WAS TO TWEAK HIGH UP A DEGREE SOUTHWEST
AS RAP HAD TEMPERATURES THERE NEAR 80 LATER TODAY.
.PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
A DRY EASTERLY FLOW WILL CONTINUE ACROSS THE FORECAST AREA DURING
THE DAY WITH HIGH PRESSURE OFF TO THE NORTHEAST. THIS WILL KEEP LOW
LEVELS PRETTY DRY. MEANWHILE...MID AND HIGH CLOUDS WILL INCREASE
THIS AFTERNOON AS AN UPPER SYSTEM AND SURFACE LOW BEGIN THEIR
APPROACH.
FORCING REMAINS TO THE WEST OF THE AREA UNTIL VERY LATE IN THE TODAY
PERIOD. LOW LEVELS REMAIN QUITE DRY THOUGH...SO FEEL THAT ANY
CHANCES FOR RAIN ACROSS THE FAR SOUTHWEST FORECAST AREA ARE TOO LOW
TO MENTION. WILL CONTINUE WITH A DRY FORECAST ALL AREAS TODAY.
A BLEND OF MODEL TEMPERATURES LOOKS GOOD GIVEN EXPECTED
CONDITIONS...AND THIS ENDS UP PRETTY CLOSE TO MAV MOS.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 313 AM EDT TUE SEP 24 2013
FOCUS IS ON CHANCES FOR RAIN EARLY IN THE PERIOD. WITH THE BIG
PICTURE MODELS ARE CLOSE ENOUGH. HOWEVER NAM LOOKS TO OVERDO LOW
LEVEL MOISTURE AS SEEN IN ITS HIGHER DEWPOINT FORECAST. THIS DOESN/T
LOOK REASONABLE GIVEN AN EASTERLY COMPONENT TO THE WINDS ACROSS THE
AREA THROUGH THE PERIOD. WENT CLOSER TO GFS/ECMWF UNLESS NOTED BELOW.
THE SURFACE LOW WILL WEAKEN AS IT MOVES SOUTHWEST OF THE AREA
TONIGHT AND WEDNESDAY. MOST OF THE FORCING WILL BE ALOFT WITH THE
UPPER LOW. HOWEVER MODEL TIME SECTIONS SHOW THAT BEST MOISTURE
DOESN/T LINE UP WITH BEST LIFT.
MODEL REFLECTIVITY FORECASTS FROM THE NCEP AND NSSL WRF SHOW LITTLE
RAINFALL WITH THE SYSTEM AS WELL. THUS CONFIDENCE FOR GETTING
MEASURABLE RAIN IS LOW. WILL UNDERCUT MOS POPS AND GO SLIGHT CHANCE
TO LOW CHANCE POPS ACROSS THE SOUTHERN FORECAST AREA TONIGHT INTO
WEDNESDAY. INSTABILITY IS MEAGER AT BEST SO WILL CONTINUE TO LEAVE
OUT THUNDER MENTION.
UPPER RIDGING AND SURFACE HIGH PRESSURE WILL THEN BUILD INTO THE
AREA FOR THE REMAINDER OF THE SHORT TERM PROVIDING MOSTLY CLEAR
SKIES AND DRY CONDITIONS.
FOR TEMPERATURES...GENERALLY STUCK WITH A BLEND OF MODELS...WHICH
ENDS UP NOT TOO FAR OFF FROM MAV MOS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 243 AM EDT TUE SEP 24 2013
RIDGING ALOFT AND A STRONG SURFACE HIGH PRESSURE RIDGE WILL REMAIN
THE MAIN INFLUENCES ON WEATHER OVER THE OHIO VALLEY FRIDAY THROUGH
THE FIRST HALF OF THE WEEKEND. WARM DRY WEATHER WILL CONTINUE
ACROSS THE REGION...HIGHLIGHTED BY MAINLY CLEAR SKIES AND TEMPS IN
THE UPPER 70S AND LOWER 80S FRIDAY AND SATURDAY.
EXTENDED MODEL GUIDANCE HAS CONTINUED TO SLOW THE APPROACH AND
ARRIVAL OF A COLD FRONT...WITH THE ECMWF...OP GFS AND GFS ENSEMBLE
MEAN ALL FAVORING BULK OF THE PRECIP COMING SUNDAY AS THE FRONT
SWINGS INTO THE OHIO VALLEY. FAVOR THE SLOWER SOLUTION CONSIDERING
THE OVERALL STRENGTH OF THE RIDGING ALOFT AND SURFACE HIGH...AND
THE TENDENCY FOR MODELS TO UNDERESTIMATE THAT STRENGTH AND BREAK
DOWN RIDGING TOO QUICKLY THIS FAR OUT. HAVE CUT BACK ON ALLBLEND
POPS SUBSTANTIALLY FOR SATURDAY NIGHT...KEEPING ONLY LOW CHANCE
POPS OVER THE NORTHERN WABASH VALLEY. WILL CONTINUE WITH 40-50
POPS SUNDAY WITH POPS DIMINISHING FROM WEST TO EAST SUNDAY NIGHT
AS THE FRONT SHIFTS EAST. WITH LITTLE INSTABILITY ACCOMPANYING THE
BOUNDARY...WILL ONLY CARRY ISOLATED THUNDER ON SUNDAY.
HIGH PRESSURE WILL RETURN TO BEGIN NEXT WEEK. HIGH TEMPS ARE
LIKELY TO FALL BACK INTO THE UPPER 60S AND LOWER 70S FOR MONDAY
AND TUESDAY AS COLD ADVECTION DEVELOPS IN WAKE OF THE FRONTAL
PASSAGE.
&&
.AVIATION /DISCUSSION FOR THE 24/1800Z TAF ISSUANCE/...
ISSUED AT 1242 PM EDT TUE SEP 24 2013
VFR CONDITIONS ARE EXPECTED TO BE THE PREDOMINANT FLIGHT CATEGORY
FOR MAJORITY OF TAF PERIOD. THE ONLY EXCEPTION WILL BE AT KHUF AND
KBMG LATE IN TAF PERIOD WHERE CONDITIONS WILL BE CLOSE TO THE
VFR/MVFR MARK AS AN UPPER LEVEL WAVE TRIGGERS LIGHT RAIN SHOWERS.
INCLUDED MENTION OF VCSH AT KBMG AND KHUF TOMORROW MORNING...BUT
CONFIDENCE IS LOW DUE TO LACK OF MOISTURE. WINDS WILL START OUT
SOUTHEASTERLY AT BEGINNING OF TAF PERIOD AND BACK SLIGHTLY TO THE
EAST/NORTHEAST THROUGH THE COURSE OF THE PERIOD. SUSTAINED SPEEDS
WILL RANGE BETWEEN 4 TO 8 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50/JH
SHORT TERM...50
LONG TERM....RYAN
AVIATION...TDUD
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FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS MARQUETTE MI
200 PM EDT TUE SEP 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 336 AM EDT TUE SEP 24 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW AN UPR RDG OVER
THE GREAT LKS BTWN A CLOSED LO OVER THE CNDN MARITIMES AND A LARGER
SCALE TROF OFF THE W COAST. SFC HI PRES UNDER THE SLOWLY BLDG UPR
RDG IN THE GREAT LKS EXTENDS FM QUEBEC SWWD TO NEAR THE SAULT. WITH
THE LARGER SCALE SUBSIDENCE AND BONE DRY MID LVLS ABV THE SUBSIDENCE
INVRN SHOWN AT H9 ON THE 00Z GRB RAOB...SKIES ARE CURRENTLY MOCLR.
ALTHOUGH A LLVL SE FLOW IS PRESENT OVER NRN LK MI ON THE WRN FLANK
OF THE SFC RDG AXIS LIKE YESTERDAY MRNG...THERE IS SO FAR NO LO CLD
SHOWING UP OVER NRN LK MI DUE TO PRESENCE OF WARMER/DRIER AIR BLO A
LOWER INVRN BASE THAN WAS PRESENT 24 HRS AGO. SFC TEMPS HAVE STILL
DIPPED AS LO AS THE 30S AT SOME OF THE COLD SPOTS OVER THE INTERIOR
SCENTRAL AND E UNDER A FLATTER PRES GRADIENT CLOSER TO THE RDG AXIS.
A SHARPER PRES GRADIENT/STRONGER SW FLOW IS RESTRICTING THE DIURNAL
TEMP DROP OVER THE W AND NCENTRAL NEAR LK SUP. LOOKING FARTHER TO
THE W...A FAIRLY VIGOROUS NEGATIVELY TILTED SHRTWV IS PRESENT OVER
THE CENTRAL PLAINS AND LIFTING ENEWD E OF THE WRN TROF. PCPN AND
EVEN MUCH IN THE WAY OF CLDS IN ADVANCE OF THIS FEATURE AND
ACCOMPANYING SFC LO IN NEBRASKA ARE LIMITED BY VERY DRY AIR SHOWN ON
NEARBY 00Z RAOBS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE POTENTIAL LO CLDS NEAR LK
MI AND TEMPS. WITH CLOSED LO SPINNING OVER THE CNDN MARITIMES...THE
PATTERN WL REMAIN NEARLY STAGNANT THRU TNGT. WITH THE UPR RDG
REMAINING NEARLY STNRY OVER THE GREAT LKS...SHRTWV MOVING E THRU THE
PLAINS IS PROGGED TO WEAKEN AND PASS WELL TO THE S OF UPR MI AND
HAVE NO IMPACT ON THE CWA.
TODAY...ALTHOUGH NO CLDS HAVE FORMED AS OF 06Z...SOME OF THE SHORTER
TERM MODELS HINT SOME LK EFFECT LO CLDS WL FORM OVER NRN LK MI AND
THE SE CWA THRU SUNRISE AIDED BY NOCTURNAL COOLING OF SHALLOW SUB
INVRN LYR. ON THE OTHER HAND...SOME OF THE HIER RESOLUTION GUIDANCE
THAT HAS HAD A GOOD TRACK RECORD WITH THIS LO CLD IN RECENT DAYS...
SPECIFICALLY THE 00Z LOCAL WRF-ARW MODEL AND SOME RAPID UPDATE
MODELS...SHOW LIMITED LK EFFECT LO CLDS. GIVEN THE WARMER TEMPS
OBSVD AT THE INVRN BASE...SUSPECT FOG RELATED TO RADIATION COOLING
OVER LAND WL BE MORE LIKELY AT LEAST OVER THE INTERIOR SCENTRAL AND
E. SO ADDED SOME FOG/LO CLD IN THIS AREA INTO MID MRNG. WITH LOWER
SUN ANGLE...SOME LO CLD MIGHT LINGER INTO EARLY AFTN BEFORE BURNING
OFF. OVER THE W...ABUNDANT SUNSHINE IN THE PRESENCE OF H85 TEMPS
NEAR 12Z WL BOOST MAX TEMPS INTO THE 70S AWAY FM THE INFLUENCE OF LK
SUP IN LLVL E-SE FLOW. AREAS OVER THE E AND SCENTRAL WL BE COOLER...
ESPECIALLY IF ANY LO CLDS THAT FORM ARE MORE EXTENSIVE AND LINGER
LONGER.
TNGT...WITH A WEAKER PRES GRADIENT TNGT AS THE SFC HI PRES RDG
EXPANDS A BIT TO THE W AND MID LVL DRY AIR/PWAT NEAR 0.50 INCH
LINGERING...TENDED TOWARD THE LO END OF GUIDANCE FOR MIN TEMPS UNDER
MOCLR SKIES. EXPECT SOME FOG TO DVLP UNDER THESE CONDITIONS WITH
LENGTHENING DARKNESS. THERE MAY ALSO BE SOME FROST AT SOME OF THE
INTERIOR COLDER LOCATIONS... BUT THE EXPECTED COVERAGE SHOULD NOT BE
ENUF TO JUSTIFY A FROST ADVY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 336 AM EDT TUE SEP 24 2013
THE SECOND HALF OF THE WORK WEEK WILL SEE THE AREA REMAINING UNDER
THE INFLUENCE OF THE UPPER RIDGE OVER THE GREAT LAKES AND ONTARIO
AND A SURFACE HIGH STATIONED OVER EASTERN ONTARIO AND WESTERN
QUEBEC. THIS SETUP WILL CONTINUE WARM AND DRY CONDITIONS OVER THE
U.P. THROUGH FRIDAY. WILL CONTINUE THE MOSTLY SUNNY IDEA FOR THE
FORECAST WITH HIGHS IN THE UPPER 60S AND LOWER 70S EACH DAY.
FOR THE WEEKEND...THE UPPER TROUGH CURRENTLY APPROACHING THE
PACIFIC NORTHWEST WILL BEGIN TO MOVE OUT OF THE ROCKIES ON FRIDAY
AND THROUGH THE UPPER GREAT LAKES REGION THIS WEEKEND. LATEST
GFS/CANADIAN RUNS HAVE TRENDED TOWARDS THE SLOWER ECMWF RUN AND
WILL CONTINUE TO TREND THE POP FORECASTS TOWARDS THAT SLOWER
SOLUTION. THAT SEEMS REASONABLE WITH THE STRONG RIDGE OVER OUR
AREA AND THE SLOW TO EXIT LOW DEPARTING THE CANADIAN MARITIMES. NOW
INSTEAD OF THE FRONT AND UPPER TROUGH MOVING THROUGH FRIDAY NIGHT
AND SATURDAY (AS SHOWN THE LAST COUPLE OF NIGHTS)...THEY LOOK TO
MOVE ACROSS THE AREA SATURDAY NIGHT INTO SUNDAY. THERE COULD
STILL BE SOME SHOWERS OVER WESTERN LAKE SUPERIOR AND POTENTIALLY
WESTERN UPPER MICHIGAN FRIDAY NIGHT INTO SATURDAY...ASSOCIATED WITH
AN AREA OF FGEN ALONG THE ELONGATED SURFACE TROUGH THAT IS SETUP
OVER THE MN ARROWHEAD. THUS...WILL KEEP AT LEAST SOME SLIGHT CHANCE
POPS OVER THE WESTERN THIRD OF THE CWA FOR FRIDAY NIGHT INTO
SATURDAY BEFORE TRANSITIONING IT ACROSS THE REST OF THE CWA. WITH
THE LATEST TRENDS...THERE COULD BE A DECENT SOAKING RAIN FOR THE
WESTERN CWA DUE TO SLOW EASTWARD MOVEMENT AND SOUTHWESTERLY FLOW
AHEAD OF THE TROUGH. THAT AREA HAS BEEN DRY THIS MONTH...SO IT
WILL BE MUCH NEEDED. FINALLY...OPTED TO REMOVE THUNDER FROM ALL BUT
FAR WESTERN LAKE SUPERIOR (FRIDAY AFTERNOON/EVENING) AS
SHOWALTERS CONTINUE TO LOOK MARGINAL WITH VERY LIMITED MUCAPE VALUES
(LESS THAN 150 J/KG).
MODELS DIFFERENCES GROW HEADING INTO NEXT WEEK...AS THE
ECMWF/CANADIAN CONTINUE TO REINFORCE THE UPPER TROUGH IN THE
UPPER GREAT LAKES. MEANWHILE...THE 18Z GFS WAS VERY PROGRESSIVE AND
THE 00Z GFS IS HALFWAY BETWEEN THE PREVIOUS RUN AND THE
ECMWF/CANADIAN/GFS-ENS. LATE ARRIVING 00Z ECMWF HAS MOVED IN A
SLIGHTLY DIFFERENT DIRECTION...WITH WEAK RIDGING BEFORE ANOTHER
WAVE ON TUESDAY. THUS...WILL JUST GO WITH A SILENT 20 POP.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 159 PM EDT TUE SEP 24 2013
VFR CONDITIONS ARE EXPECTED INTO THIS EVENING AT ALL SITES AS HIGH
PRESSURE REMAINS IN CONTROL. THE MAIN CONCERN IN THIS PERIOD WILL BE
FOG DEVELOPMENT AT SAW...AND POSSIBLY CMX OVERNIGHT. IWD SHOULD
REMAIN VFR WITH LIGHT DOWNSLOPING S WINDS.
PERSISTENT CONDITIONS FROM LAST NIGHT INTO TONIGHT AND CALM WINDS
UNDER HIGH PRESSURE WILL LEAD TO RADIATIONAL FOG DEVELOPMENT ACROSS
CENTRAL UPPER MI OVERNIGHT. LIGHT SE UPSLOPE FLOW WILL ALSO ASSIST
DEVELOPMENT AT SAW. CURRENTLY HAVE SAW FORECAST TO REACH THE
LIFR-VLIFR THRESHOLD LATE TONIGHT INTO WEDNESDAY MORNING...THOUGH
WOULD NOT BE SURPRISED IF VLIFR/LANDING MIN CONDITIONS ARE OBSERVED
FOR SEVERAL HOURS BEFORE 12Z. AS FOR CMX...SOME BRIEF GROUND FOG
DEVELOPMENT MAY BEGIN VERY LATE TONIGHT AS WAS SEEN EARLY THIS
MORNING...BUT EXPECTATION IS THAT MVFR CONDITIONS TO POSSIBLY IFR
CONDITIONS WILL OCCUR.
FOG/LOW STRATUS TOOK A BIT OF TIME TO MIX OUT THIS MORNING...AND DO
NOT SEE WHY THAT WILL NOT BE THE CASE WEDNESDAY MORNING. HAVE
INTRODUCED A SLOW IMPROVING TREND AT SAW THROUGH 18Z.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 336 AM EDT TUE SEP 24 2013
WITH RELATIVELY WEAK PRES GRADIENT OVER THE UPPER GREAT LAKES...
EXPECT WINDS INTO FRI TO REMAIN UNDER 20 KTS. THE APPROACH OF A COLD
FRONT TOWARD SAT AND SHARPENING PRES GRADIENT MAY LEAD TO A BIT
STRONGER S WINDS UP TO 20-25 KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KLUBER
MARINE...KC
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
234 PM CDT Tue Sep 24 2013
.SHORT TERM...(This Evening through Wednesday Night)
Issued at 231 PM CDT TUE SEP 24 2013
Relatively tranquil weather will prevail through much of the next 36
hours, with the one potential exception this afternoon.
As of early this afternoon, a surface low pressure center in the
process of occluding was analyzed near Kansas City, moving
east-southeastward. The shortwave trough aloft was nearly vertically
stacked, with the H85-H5 within 150 miles of the occluding surface
low. Visible satellite imagery has shown a gradual increase in
low-level cumulus, with clearing persistent ahead of the surface
low. A narrow corridor of weak instability has begun to develop
within a southeast to northwest arc. Short-term model guidance has
shown a forecasted increase in 0-3km CAPE of up to 200-400J/Kg by
late afternoon over northeast portions of the EAX forecast area.
While the forecasted instability is modest at best, this in
combination with strong vertical ascent may promote low-topped
convection to develop by mid to late afternoon. The RUC, NAM, GFS,
GEM, and HRRR outputs all suggest convection to develop in
northeastern sections of the CWA. With an environment characterized
by sufficient instability to maintain low-topped convection,
concomitant with moderate low-level (sfc-H85) directional wind shear
and moderate surface vorticity, the potential exists for a transient
funnel cloud or two underneath persistent updraft bases later this
afternoon in any mature convection that develops. The probability
for this to occur is relatively low, and any chance a vortex would
reach the surface is very low. Overall coverage of lightning
occurrence should be low as well due to the low-topped nature
anticipated with the convection. Much of this forecasted activity is
expected to wane shortly after sunset with the loss of diurnal
instability.
Otherwise, as the shortwave trough shifts east of the area tonight,
an upper ridge will build into the central CONUS on Wednesday. A
notable increase in high temperatures is expected tomorrow afternoon
with highs reaching the upper 70s to lower 80s under mostly clear
skies.
.LONG TERM...(Thursday through Tuesday)
Issued at 231 PM CDT TUE SEP 24 2013
For the later periods of the forecast, lovely late summer/early fall
conditions will dominate, though some thunderstorms might put a
damper on the beginning of the weekend. As Thursday dawns, an
amplified pattern will be in place across the nation, with a large
western CONUS trough juxtaposed against building eastern CONUS
ridge. This will leave our section of the country under rather
benign regime for Thursday and Friday. Models advertise 850mb
temperatures in the mid-teens late in the work week, leaving
expectations that highs will range in the 80s. These above
seasonally average temperatures late in the work week will be
occurring ahead of a frontal passage expected to occur Saturday.
Over the weekend the western CONUS trough will be filling and
lifting through the Plains States. The resulting frontal passage is
currently advertised to occur in our section of Kansas and Missouri
during the daylight hours of Saturday. Models are in decent
agreement on the evolution of the trough and timing of the
associated frontal passage, though given the jet streak noted diving
under the trough as it lifts out thoughts are that the eventual
timing will slow, leaving the frontal passage through our forecast
area lingering into the overnight hours of Saturday. Expectations
are that convection along the front will start Friday night across
areas from central Kansas into eastern Nebraska. These storms will
likely spread into eastern Kansas and far western Missouri towards
sunrise Saturday morning. Slow progress of the front might keep
storms percolating across western Missouri through much of the day,
while also slowly spreading east with the front. Have kept fairly
expansive likely POPs in place for Saturday night owing to low
confidence that the front will have completely cleared the forecast
area before nightfall.
Otherwise, beyond Saturday`s potential stormy weather, the remainder
of the weekend and into next work week (Sunday through Tuesday)
looks rather beautiful. Temperatures are currently expected to range
between highs in the 70s and lows in the 50s as a quasi-zonal upper
level pattern moves into the Plains in the wake of the exiting
trough.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1202 PM CDT TUE SEP 24 2013
Tricky ceiling forecast this afternoon/evening for terminals as
center of surface low passes nearby. Expect mainly high-end MVFR or
low-end VFR ceiling heights through early evening before cloud
coverage decreases and heights increase. As for precipitation,
expect TAF sites to remain dry. Winds will be somewhat variable as
surface flow veers with time.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Blair
LONG TERM...Cutter
AVIATION...Blair
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1254 PM CDT TUE SEP 24 2013
.UPDATE...
ISSUED AT 904 AM CDT TUE SEP 24 2013
LOW LEVEL STRATUS WILL BE SLOW TO CLEAR ACROSS THE AREA THIS
MORNING...WITH A FEW BREAKS ALREADY EVIDENT ACROSS THE WESTERN
FRINGES OF THE CWA. EXPECT THIS STRATUS TO CLEAR FROM WEST TO EAST
THROUGH THE AFTERNOON...WITH SOME PATCHY DRIZZLE POSSIBLE ACROSS
NORTHEASTERN AREAS THROUGH ABOUT NOON. OTHER THAN INCREASING
CLOUD COVER AND ADDING SOME PATCHY DRIZZLE PER REPORTS FROM AROUND
THE REGION...NO OTHER CHANGES NECESSARY TO THE INHERITED FORECAST
AS TEMPERATURES LOOK ON TRACK AND A MOSTLY SUNNY AFTERNOON WILL
EVENTUALLY EMERGE ACROSS MOST...IF NOT ALL...OF THE LOCAL FORECAST
AREA.
UPDATE ISSUED AT 700 AM CDT TUE SEP 24 2013
AS DISCUSSED IN GREATER DETAIL IN THE PRIMARY OVERNIGHT
DISCUSSION...LOW STRATUS TRENDS CONTINUE TO BE A HEADACHE.
ALTHOUGH A FEW CORRIDORS OF CLEARING REMAIN...MUCH OF THE CWA IS
NOW UNDER FAIRLY WIDESPREAD LOW CLOUDS...WITH THE HRRR SUGGESTING
THAT GENERALLY THE EASTERN 3/4 OF THE CWA COULD REMAIN FAIRLY
SOCKED IN THROUGH MID-DAY. AS A RESULT...YET AGAIN BUMPED UP SKY
COVER PERCENTAGES AND SLOWED THE RATE OF WEST-TO-EAST
CLEARING...BUT STILL THINKING THAT MOST AREAS SHOULD AVERAGE NO
WORSE THAN PARTLY CLOUDY THROUGH THE BALANCE OF THE AFTERNOON.
WILL STAY THE COURSE WITH PREVIOUS HIGH TEMPS FOR NOW...AS ANY
CLEARING SHOULD RESULT IN A QUICK RISE AND HELP OFFSET ANY POTENTIAL
DELAY IN WARMING FROM MORNING CLOUD COVER. ON ONE FINAL
NOTE...RADAR TRENDS SUPPORTED KILLING THE SLIGHT POPS THAT
ORIGINALLY LINGERED IN A FEW FAR NORTHEAST COUNTIES THROUGH
15Z/10AM...SO NOW THE FORECAST IS OFFICIALLY VOID OF ALL PRECIP
MENTION UNTIL THURS NIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM CDT TUE SEP 24 2013
ALTHOUGH MOST IF NOT ALL OF THE CWA IS LOOKING AT A DRY AND FAIRLY
UNEVENTFUL UPCOMING 24 HOURS...ESPECIALLY THE DAYTIME HOURS HAVE
BECOME TRICKIER-THAN-EXPECTED MAINLY REGARDING THE EVOLUTION OF
SKY COVER/TEMPERATURES...AS LOW CLOUDS COULD BE STUBBORNLY SLOW TO
DEPART MAINLY WITHIN THE EASTERN 1/2 OF THE CWA...BRINGING 5+ DEGREE
TEMP BUST POTENTIAL VERY MUCH INTO PLAY.
08Z OBJECTIVE SURFACE ANALYSIS HIGHLIGHTS A SLOWLY-WEAKENING 1004
MILLIBAR LOW PRESSURE CENTER...CENTERED OVER THE CLAY/FILLMORE
COUNTY AREA...WHILE IN ITS WAKE THE LEADING EDGES OF HIGH PRESSURE
AROUND 1016MB HAS WORKED INTO THE NEB PANHANDLE. WITH THE MAJORITY
OF THE CWA POSITIONED BEHIND THE DEPARTING LOW...EARLY MORNING
BREEZES ARE MAINLY FROM THE WEST-NORTHWEST...WITH THE STRONGEST
SPEEDS WITH GUSTS OF 20+ MPH FOCUSED ACROSS THE SOUTHWESTERN HALF
OF THE AREA...WITH LIGHTER SPEEDS STILL HOLDING ON FOR AT LEAST A
FEW MORE HOURS WITHIN MUCH OF THE NORTHEAST 1/2. ALOFT...WATER
VAPOR IMAGERY AND SHORT TERM MODEL DATA CLEARLY REVEAL A WELL-
DEFINED...NOT QUITE VERTICALLY STACKED LOW PRESSURE SYSTEM
DEPARTING EASTWARD ACROSS THE EASTERN 1/4 OF NEB...WITH A CLOSED
500MB CIRCULATION CENTERED NEAR NORFOLK. AS A RESULT...THE PRIMARY
MID LEVEL CONVERGENCE/DEFORMATION ZONE AT THIS HOUR IS FOCUSING
WIDESPREAD MAINLY LIGHT RAIN 50+ MILES NORTHEAST OF THE
CWA. CLOUD-WISE...11-3.9 MICRON SATELLITE IMAGERY DEPICTS A
FAIRLY COMPLEX AND EVER-CHANGING MIXTURE OF CLEAR SKIES ALONG WITH
PASSING BATCHES OF MID CLOUDS AND LOW STRATUS. WHILE MOST OF THESE
LOWER CEILINGS WITHIN THE CWA ARE AT/ABOVE 1500 FT...A CORRIDOR OF
LOWER CEILINGS BETWEEN 500-1000 FT SEEMS TO BE LURKING JUST
NORTHWEST OF THE CWA ALONG A BROKEN BOW-AINSWORTH AXIS...WITH
THESE LOW CLOUDS POSSIBLY EVEN SUPPORTING SOME PATCHY LIGHT
DRIZZLE. TEMP-WISE...MOST OF THE CWA APPEARS HEADED FOR OVERNIGHT
LOWS IN THE MID 50S...WITH ANY LOW 50S/UPPER 40S MOST FAVORED IN
FAR WESTERN COUNTIES.
AS THE EARLY MORNING/DAYTIME HOURS WEAR ON...THE BIG PICTURE ALOFT
INVOLVES THE MID LEVEL SHORTWAVE TROUGH/ASSOCIATED CLOSED LOW
CONTINUING ITS STEADY TREK EASTWARD...WITH THE 500MB CIRCULATION
CENTER INTO SOUTHWEST IA BY 18Z...AND THEN OVER NORTH CENTRAL MO
BY 00Z/7PM. AS THIS LOW DEPARTS...A BROAD AREA OF SHORTWAVE
RIDGING AND ASSOCIATED HEIGHT RISES WILL OVERSPREAD THE CENTRAL
PLAINS. AT THE SURFACE...THE LOW PRESSURE CENTER CURRENTLY OVER
SOUTHEAST NEB WILL CONTINUE TO WEAKEN AS IT SLIDES INTO CENTRAL MO
OVER THE COURSE OF THE DAY...ALLOWING A MODEST RIDGE AXIS TO BUILD
INTO THE LOCAL AREA WITH TIME AND RELAX THE SURFACE PRESSURE
GRADIENT. HOWEVER...BREEZES WILL STILL BE FAIRLY ELEVATED FOR
MUCH OF THE DAY TODAY...LARGELY OWING TO MIXING CLIMBING UP TO
AROUND 850MB...WHERE AN ENHANCED CORRIDOR OF 30-40KT NORTHERLY
WINDS WILL LINGER THROUGH MID-DAY BEFORE STEADILY WEAKENING IN THE
AFTERNOON. THE NET RESULT WILL BE SUSTAINED NORTH-NORTHWEST WIND
SPEEDS 15-20 MPH WITH GUSTS 25+ MPH THROUGH THIS MORNING...BEFORE
DIMINISHING TO MORE SO SUSTAINED 10-15 MPH SPEEDS THIS
AFTERNOON...AND ONLY 5-10 MPH CLOSER TO SUNSET. AS FOR PRECIP
CHANCES...ALTHOUGH RADAR TRENDS AND SHORT TERM MODEL DATA
INCLUDING THE HRRR PRETTY STRONGLY SUGGEST THAN ANY RISK OF
MEASURABLE LIGHT RAIN SHOULD BE OVER BY 12Z...WENT AHEAD AND
LINGERED A TOKEN 20 POP IN THE EXTREME NORTHEAST
NANCE/MERRICK/POLK AREA THROUGH 15Z IN CASE SOMETHING MANAGES TO
STILL WRAP AROUND THE BACK SIDE OF THE LOW. THE BIG CHALLENGE
TODAY SEEMS TO BE CENTERED AROUND SKY COVER. 24 HOURS AGO...IT WAS
ASSUMED THAT MID LEVEL CLOUDS WOULD QUICKLY MOVE OFF EAST OF THE
CWA TODAY WITH THE PARENT SYSTEM. HOWEVER...LATEST SATELLITE AND
SHORT TERM MODEL DATA INCLUDING THE HRRR LOW CLOUD PRODUCT NOW
SUGGEST THAT THE AREAL COVERAGE OF LOW STRATUS MAY IN FACT
INCREASE BEFORE SUNRISE FROM THE NORTHWEST...AND THEN POSSIBLY
HANG VERY STUBBORNLY MAINLY ACROSS THE CENTRAL/EASTERN CWA EVEN
INTO THE AFTERNOON HOURS. ALTHOUGH HAVE NOT BOUGHT FULL-BORE INTO
THE VERY PESSIMISTIC RUC/HRRR SOLUTIONS REGARDING LOW CLOUDS
TODAY...DID INCREASE SKY COVER PERCENTAGES VERSUS PREVIOUS...AND
ALSO DELAYED THE WEST-EAST CLEARING TREND. HOWEVER...PLEASE NOTE
THAT ESPECIALLY EASTERN COUNTIES ALONG/NEAR HIGHWAY 81 MAY REALLY
STRUGGLE TO SEE MUCH SUN UNTIL MAYBE LATE AFTERNOON...AND DAY
SHIFT MAY HAVE TO MAKE SOME PRETTY NOTICEABLE ADJUSTMENTS TO SKY
COVER AND RESULTANT HIGH TEMPS. FOR NOW THOUGH...OPTED TO ONLY
SHAVE 1-2 DEGREES OFF PREVIOUS HIGHS IN MOST AREAS...RANGING FROM
LOW 70S FAR EAST TO UPPER 70S FAR SOUTHWEST...AND AROUND 73 TRI-
CITIES. IF CLOUDS ARE SLOW TO DEPART HOWEVER...SOME EASTERN AREAS
MAY STRUGGLE TO LEAVE THE 60S. ON ONE FINAL DAYTIME
NOTE...ALTHOUGH HAVE DEWPOINTS DROPPING INTO THE LOW-MID 40S
ACROSS MUCH OF THE WESTERN CWA DURING THE AFTERNOON...THESE VALUES
ARE NOT QUITE AS LOW AS ANTICIPATED 24 HOURS AGO...AND THIS KEEPS
ANY AFTERNOON RELATIVE HUMIDITY VALUES AS LOW AS 25-30 PERCENT
CONFINED TO MAINLY JUST THE FURNAS COUNTY AREA.
FOR THE EVENING/NIGHT 00Z-12Z PERIOD...WILL RUN WITH THE
ASSUMPTION THAT EVEN IF LOW STRATUS LINGERS QUITE AWHILE INTO THE
AFTERNOON IN SOME AREAS...THAT IT SHOULD BE SAFELY EAST OF THE CWA
BY SUNSET...THUS RESULTING IN A CLEAR OVERNIGHT AREA-WIDE WITH
ESSENTIALLY ZERO RISK OF PRECIP. ON THE BIG PICTURE...THE HEART OF
THE AFOREMENTIONED MID/UPPER LEVEL SHORTWAVE RIDGE AXIS WILL PASS
DIRECTLY OVER THE CWA...VERY SIMILAR TO LAST FRIDAY NIGHT. ALSO
SIMILAR TO LAST FRIDAY AT THE SURFACE...VERY LIGHT/VARIABLE
BREEZES IN THE EVENING WILL GRADUALLY GIVE WAY TO LIGHT SOUTHEAST
BREEZES LATER IN THE NIGHT AS THE SURFACE RIDGE AXIS DRIFTS
EASTWARD ACROSS THE CWA. HOWEVER...COMPARED TO 24 HOURS AGO IT NOW
APPEARS THAT DEWPOINTS WILL NOT DROP OFF QUITE AS FAR...AND THUS
GUIDANCE/MODELS HAVE TRENDED A FEW DEGREES MILDER FOR OVERNIGHT
LOWS. AS A RESULT...NUDGED UP LOWS 1-2 DEGREES MOST AREAS VERSUS
PREVIOUS...AIMING MOST OF THE CWA BETWEEN 50-53...BUT WITH
PREDOMINANTLY MID-UPPER 40S IN A FEW OF THE FAR WESTERN
NORTHERN/COUNTIES. DESPITE THE LIGHT OVERNIGHT BREEZES...AM NOT
EXPECTING IMPACTFUL FOG TO BE AN ISSUE...ALTHOUGH SOME VERY LIGHT
FOG/HAZE IS PROBABLY NOT OUT OF THE QUESTION...BUT IS ALSO NOT
WORTH ADVERTISING IN THE FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM CDT TUE SEP 24 2013
PATTERN: THE CPC OBSERVED H5 HGT ANOMALY TOOLS SHOW THAT THE LOW
FREQUENCY /LGWV/ FLOW OF THE PAST 90 DAYS LARGELY REMAINS IN PLACE
OVER THE NRN HEMISPHERE. HOWEVER...WE HAVE RECENTLY SEEN
AMPLIFICATION ESPECIALLY WITH THE ERN PAC TROF. OTHER ADJUSTMENTS
SHOW THAT THE +HGT ANOMALY WHICH HAS RESIDED OVER WRN N AMERICA HAS
SHIFT TO THE E...ALLOWING THE TEMPORARY ESTABLISHMENT OF A WRN N
AMERICA TROF. THIS TROF WILL ONLY BE WITH US THIS WEEK AND OFFERS
ONE MORE SHOT AT DECENT RAINFALL. THE NAO HAS TURNED SHARPLY
NEGATIVE AS THE PERSISTENT -HGT ANOMALY OVER GREENLAND HAS BEEN
REPLACED WITH +HGT ANOMALIES. THIS COMBINED WITH THE A PAIR OF
STORMS CROSSING THE NRN PAC WILL RETURN RIDGING TO WRN N AMERICA
THIS WEEKEND. SO THE BOTTOM LINE IS...EXCEPT FOR A BRIEF WINDOW THU
NGT-FRI...DRY WX WILL CONT. TEMPS WILL BE VARIABLE BUT PROBABLY
AVERAGE PRETTY CLOSE TO NORMAL OVER THE NEXT 10 DAYS.
ALOFT: SW FLOW WILL DEVELOP OVER THE CNTRL PLAINS WED AND CONT THRU
FRI...AS THE WRN USA TROF FULLY RELOADS. CYCLOGENESIS WILL OCCUR
THU...WITH THE MAIN UPR LOW HEADING N INTO CANADA. THE MAIN UPR TROF
WILL BE LEFT BEHIND AND BEGIN LIFTING NE...CROSSING THE CNTRL PLAINS
SAT. NW FLOW FOLLOWS SUN-MON BUT THERE IS DISAGREEMENT/UNCERTAINTY
IN THE AMPLITUDE OF THE RIDGE MOVING INTO THE W.
SFC: A PAC COLD FRONT WILL EXTEND FROM THE NRN ROCKIES TO CNTRL CA
WED...WITH A LEE-SIDE TROF IN PLACE. THIS FRONT WILL ADVANCE E AND
EMERGE ONTO THE PLAINS BY DAWN THU. HOWEVER...THE SRN PORTION WILL
REMAIN STATIONARY DUE TO MINIMAL MOVEMENT OF THE BASE OF THE TROF.
THE SLOW EJECTION OF THE TROF MEANS THE FWD PROGRESS OF THE FRONT
WILL BE SLOW. WRN USA HIGH PRES BUILDS IN SAT THRU MON.
WITH SW FLOW ALOFT ON BOTH SIDES OF THIS FRONT...IT WILL HAVE AN
ANABATIC CHARACTER. THE SLOW MOVEMENT OFFERS THE OPPORTUNITY FOR
ENTRAINMENT OF GULF MSTR. WE ARE SEEING A NARROW RIBBON OF MSTR FCST
TO SURGE NWD FRI...WITH PW NEARING 1.6".
HAZARDS: NOTHING SUBSTANTIAL...BUT THERE IS A LATE-WEEK THUNDER
THREAT. RISK OF SVR LOOKS VERY LOW.
THE DAILY DETAILS...
WED: WARM SECTOR. BREEZY AND WARMER BY 7-10F.
WED NGT: A STRONG LLJ WILL DEVELOP /55-60 KTS/ WITH LOW-LVL WINDS
VEERING TO THE SW. THIS WILL ADVECT AN EML ONTO THE PLAINS...
IMPOSING A SUBSTANTIAL CAP.
THU: WARM SECTOR. VERY WARM. ADD ANOTHER 3-7F TO WED AND THIS WILL
PUT HIGHS 10F ABOVE NORMAL. HIGHS IN THE LWR 90S LOOK LIKE A GOOD
BET OVER N-CNTRL KS.
THU NGT: SOME ISOLATED HIGH-BASED SHWRS/TSTMS ARE POSSIBLE. THIS
REALLY DEPENDS ON WHERE THE LLJ CORE SETS UP. THE EC IS FURTHER N
THAN THE GFS AND NAM. IF SHWRS/TSTMS DEVELOP RAINFALL AMTS WILL BE
VERY LIGHT.
FRI: WARM SECTOR...BUT THE FRONT THREATENS THE NW FRINGE OF THE FCST
AREA DURING PEAK HEATING. MOST OF THE FCST AREA SHOULD REMAIN DRY
FOR MOST OF THE DAY. PCPN AND CLOUDS WILL BE MOST EXTENSIVE BEHIND
THE FRONT WHICH SHOULD RESULT IN A SUBSTANTIAL TEMP CONTRAST ACROSS
THE STATE. AHEAD OF THE FRONT EXPECT THE ATMS TO BE CAPPED. SCT
TSTMS SHOULD ONLY ERUPT IN THE IMMEDIATE VICINITY OF THE FRONT IN
THE LATE AFTN.
SEVERE?: PROBABLY NOT BUT IF THERE IS A THREAT IS LOOKS VERY
MARGINAL DUE TO WEAK INSTABILITY. HOWEVER...STRENGTH OF THE WIND
FIELDS AND THE DRY SUB-CLOUD LAYER COULD SUPPORT SOME DECENT WINDS
IF A STRONGER STORM OR TWO CAN DEVELOP.
FRI NGT: COLD FRONTAL PASSAGE. THE SETUP LOOKS GOOD FOR SOME DECENT
POST-FRONTAL RAINFALL IN SOME LOCATIONS.
SAT: MUCH COOLER! PROBABLY 20F COOLER THAN FRI. IN FACT...WITH
THE UPR TROF MOVING THRU...BELIEVE FUTURE FCSTS WILL END UP LOWERING
HIGHS ANOTHER 5F OR SO. CONSENSUS OF 2M TEMPS CURRENTLY OFFERS 57F
AT ORD AND 67F AT BELOIT. NOT MUCH DIFF FROM THE 12Z/18Z CYCLES.
SWEATSHIRTS AND JACKETS MAY BE NEEDED FOR OUTDOOR ACTIVITIES.
CLOUDY TO START WITH A COUPLE LEFTOVER SHWRS OR SOME PATCHY DRZL.
CLEARING PROGRESSES FROM W TO E IN THE AFTN.
SUN-MON: BACK TO NICER WX. TEMPS REBOUND AND WITH LOW PRES MOVING
THRU THE CANADIAN ROCKIES...A LEE-SIDE TROF WILL DEVELOP AND MAY
ACTUALLY PROGRESS THRU THE FCST AREA WITH AN ATTENDANT THERMAL
RIDGE. HIGHS SHOULD BE BACK INTO THE LOW-MID 70S SUN AND UPR 70S-80
MON?
&&
.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z WEDNESDAY
AFTERNOON) ISSUED AT 1240 PM CDT TUE SEP 24 2013
PREVAILING VFR CONDITIONS ARE EXPECTED AT KGRI FOR THE NEXT 24
HOURS...ALBEIT A BRIEF MVFR CIG WILL REMAIN POSSIBLE THROUGH ABOUT
20Z. THEREAFTER...WINDS WILL BE THE PRIMARY FOCUS AS GENERALLY
CLEAR SKIES ARE EXPECTED TO PREVAIL AS A WEAK RIDGE OF HIGH
PRESSURE BUILDS ACROSS THE REGION. SOME MODELS ARE HINTING AT
LIGHT BR FORMATION TOWARDS DAYBREAK WEDNESDAY DUE TO CLEAR SKIES
AND LIGHT WINDS...BUT EXPECT JUST ENOUGH MIXING BASED ON CURRENT
WIND FORECAST TO PREVENT ANY SIGNIFICANT VISIBILITY RESTRICTIONS.
OTHERWISE...BREEZY NORTHERLY WINDS ARE EXPECTED TO CONTINUE
THROUGH ABOUT 25/00Z AS THE DEPARTING SYSTEM EXITS THE
REGION...WITH BREEZY SOUTHERLY WINDS EXPECTED TO DEVELOP AROUND
DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT BEGINS TO TIGHTEN
AHEAD OF THE NEXT DISTURBANCE EXPECTED LATE IN THE WEEK.
&&
.HYDROLOGY...
ISSUED AT 438 AM CDT TUE SEP 24 2013
OVERALL LITTLE CHANGE IN EXPECTATIONS OVERNIGHT REGARDING PLATTE
RIVER FLOODING/FLOODING POTENTIAL. WE CONTINUE TO ADVERTISE TWO
OFFICIAL FLOOD WARNINGS AT THIS TIME...ONE FOR THE RIVER GAGE NEAR
COZAD...WHICH COVERS THE PLATTE RIVER REACH ACROSS DAWSON COUNTY
INTO FAR WESTERN BUFFALO...AND A SECOND FOR THE GAGE NEAR
KEARNEY...WHICH COVERS THE REACH OF THE RIVER ALONG THE
BUFFALO/PHELPS/KEARNEY COUNTY LINE...AND THEN ACROSS THE MAJORITY
OF HALL COUNTY. ALTHOUGH THE LATEST MISSOURI BASIN RIVER FORECAST
CENTER (MBRFC) FORECAST TAKES THE GRAND ISLAND GAGE A FEW MILES
EAST OF TOWN BARELY INTO MINOR FLOOD STAGE WEDNESDAY NIGHT...WE
CONTINUE TO HOLD OFF ON A FORMAL FLOOD WARNING FOR THIS EASTERN
HALL COUNTY AREA AND POINTS EAST...MAINLY TO GIVE A BIT MORE TIME
TO FINE TUNE THE FORECAST BASED ON UPSTREAM BEHAVIOR AT THE COZAD
AND KEARNEY GAGES...AND ALSO THE OVERTON GAUGE WHICH IS NOT AN
OFFICIAL FORECAST POINT.
OVER THE PAST SEVERAL HOURS...THE GAGE ALONG THE NORTH CHANNEL AT
COZAD FINALLY REACHED MINOR FLOOD STAGE OF 6.5 FT AT 9 PM MONDAY
EVENING...AND HAS CONTINUED A STEADY CLIMB TO JUST OVER 7.2 FT AS OF
330 AM. AS A RESULT...THE CREST WHICH IS EXPECTED TO OCCUR
SOMETIME TODAY HAS BEEN NUDGED UPWARD TO 7.3 FT. THIS IS
ANTICIPATED TO BE A PROLONGED CREST WITH ONLY A VERY SLOW FALL TO
BELOW FLOOD STAGE BY SOMETIME FRIDAY. MEANWHILE...THE LATEST
OVERNIGHT TRENDS ON THE OVERTON AND KEARNEY GAGES CONTINUE TO
REFLECT VERY SLOW RISES...AND IT IS YET TO BE SEEN WHETHER THE
KEARNEY GAGE IN FACT CAN BREACH THE MINOR FLOOD STAGE OF 6.0 FT BY
LATE THIS MORNING AS THE LATEST FORECAST SUGGESTS. AT ANY RATE...A
CREST OF 7.2 FT CONTINUES TO BE FORECAST FOR KEARNEY ON
WEDNESDAY...AND AGAIN THIS WILL BE A PROLONGED CREST WITH A VERY
SLOW FALL...POSSIBLY REMAINING IN FLOOD STAGE THROUGH THE END OF
THE MONTH.
PLEASE NOTE ONLY MINOR FLOOD STAGE...AND NOT MODERATE/MAJOR
CATEGORIES...ARE ANTICIPATED ALONG THE AFOREMENTIONED FORECAST
POINTS WITHIN THE NWS HASTINGS CWA...AND THUS THE VAST MAJORITY OF
IMPACTS SHOULD REMAIN CONFINED TO THE IMMEDIATE LOWLAND AREAS
NEAR THE RIVER CHANNEL/S. THESE RIVER FORECASTS ARE UPDATED
REGULARLY PER COORDINATION BETWEEN MBRFC AND NWS HASTINGS...AND
MINOR TWEAKS IN CREST HEIGHT AND TIMING REMAIN LIKELY OVER THE
COMING DAYS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...SAR
SHORT TERM...PFANNKUCH
LONG TERM...HALBLAUB
AVIATION...SAR
HYDROLOGY...PFANNKUCH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1245 PM CDT TUE SEP 24 2013
.UPDATE...
ISSUED AT 1245 PM CDT TUE SEP 24 2013
NO MAJOR UPDATES WERE REQUIRED TO THE ONGOING FORECAST. ONLY
ADJUSTED HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 947 AM CDT TUE SEP 24 2013
FOG HAS DISSIPATED ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS
MORNING. AS A RESULT...REMOVED MORNING FOG WORDING FROM THE TEXT
PRODUCTS. OTHERWISE...SUNNY SKIES ARE EXPECTED TODAY WITH HIGHS
GENERALLY IN THE LOW 70S. THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 642 AM CDT TUE SEP 24 2013
LATEST SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE AREAS
OF FOG ALONG THE MISSOURI RIVER FROM BISMARCK SOUTH TO THE SOUTH
DAKOTA BORDER...AND EAST TOWARDS JAMESTOWN. ALSO AN AREA OF LOWER
CLOUDS NOTED NEAR THE TURTLE MOUNTAINS. WILL CONTINUE A MENTION
OF FOG FOR THESE AREAS THROUGH 15 UTC. OTHERWISE MAINLY CLEAR
SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA. SHOWERS THAT MOVED
THROUGH THE AREA LAST NIGHT HAVE ALL BUT EXITED THE FAR SOUTHEAST
CWA. UPDATED FORECAST LOWS WITH LATEST SENSIBLE WEATHER
OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CDT TUE SEP 24 2013
LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH WORKING ITS
WAY FROM CENTRAL NORTH DAKOTA INTO EASTERN NORTH DAKOTA. LOCAL
RADAR AHEAD OF THIS TROUGH CONTINUES TO SHOW SCATTERED LIGHT
SHOWERS FROM NEAR JAMESTOWN SOUTH TO ASHLEY AND EAST TO OAKES.
THIS AREA WILL WANE THROUGH 12Z AS THE UPPER TROUGH EXITS THE
COUNTY WARNING AREA. THE FOG/STRATUS LOOP INDICATES AN AREA OF
FOG/LOW CLOUDS IN ADAMS AND HETTINGER COUNTIES. THE HRRR CLOUD
CEILING HEIGHT IS ADVERTISING THIS AREA TO EXPAND SLIGHTLY AND
SLIDE SOUTHEAST...BARELY CLIPPING BISMARCK THROUGH 15Z. HAVE
FOLLOWED IT FOR THE SKY/WEATHER TRENDS EARLY THIS MORNING. OTHERWISE
WARM AIR ADVECTION COMMENCES TODAY THROUGH TONIGHT. LARGE SCALE
CONVERGENCE ALOFT WILL ALLOW FOR PLENTY OF SUNSHINE TODAY. WITH
WARM AIR ADVECTION INCREASING TUESDAY NIGHT...A CHANGE TOWARD
DIVERGENCE ALOFT ENSUES...ESPECIALLY OVER THE WEST/NORTHWEST. THE
FAR NORTHWEST IS SUSCEPTIBLE TO AN ISOLATED SHOWER/THUNDERSTORM IN
AFTER MIDNIGHT...OTHERWISE DRY WEATHER PREVAILS ELSEWHERE THROUGH
THE SHORT TERM PERIOD. H85 TEMPS BETWEEN +12C TO +16C WILL YIELD
AFTERNOON HIGHS IN THE UPPER 60S NORTH TO LOWER 70S SOUTH AND
WEST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 307 AM CDT TUE SEP 24 2013
THE MAIN FORECAST ISSUES IN THE LONG TERM WILL BE ASSOCIATED WITH
A STRONG UPPER LEVEL TROUGH THAT TAKES SHAPE OVER THE NORTHWEST
U.S. OVER THE NEXT 24 HOURS...AND TRACKS INTO THE NORTHERN HIGH
PLAINS BY THE END OF THE WORK WEEK. CURRENTLY...UPPER LEVEL
CIRCULATION CAN BE SEEN OFF THE BRITISH COLUMBIA COAST WITH A
STRONG SHORTWAVE TROUGH OVER THE EASTERN PACIFIC...OFF THE
NORTHERN CALIFORNIA COAST AND MATCHES WITH DETERMINISTIC MODELS.
THE STRONG SHORTWAVE TROUGH WILL BE THE FIRST TO INFLUENCE OUR
WEATHER AS IT MOVES ACROSS THE NORTHERN ROCKIES. STRONG SURFACE LOW
PRESSURE DEVELOPS OVER EASTERN MONTANA BY TUESDAY NIGHT WITH
INCREASING SOUTHERLY WINDS OVER WESTERN AND CENTRAL NORTH DAKOTA.
THIS WILL BRING A SMALL CHANCE OF THUNDERSTORMS TO THE FAR WEST AND
NORTHWEST DURING THE DAY ON WEDNESDAY. THUNDERSTORM CHANCES WILL
INCREASE WEDNESDAY NIGHT INTO THURSDAY AS THE SURFACE LOW SLOWS DOWN
AND TRACKS FROM WESTERN INTO CENTRAL NORTH DAKOTA DUE TO A STRONG
UPPER LEVEL JET ROUNDING THE BASE OF THE MAIN UPPER LEVEL LOW AS
IT MOVES INTO THE NORTHERN ROCKIES. INCREASING UPPER LEVEL JET
DYNAMICS ACROSS THE NORTHERN HIGH PLAINS COULD SUPPORT SCATTERED
SEVERE STORMS THAT WOULD THEN TRACK INTO THE WESTERN DAKOTAS.
THUNDERSTORMS ARE EXPECTED TO BECOME ELEVATED LATE WEDNESDAY NIGHT
INTO THURSDAY MORNING WITH A STRONG LOW LEVEL JET LIFTING INTO
CENTRAL NORTH DAKOTA. THE GREATEST THREAT FOR THUNDERSTORMS WILL
BE ACROSS FAR WESTERN AND NORTH CENTRAL NORTH DAKOTA WEDNESDAY
NIGHT THROUGH THURSDAY MORNING...ALTHOUGH WITH SUCH STRONG
DYNAMICS...SCATTERED THUNDERSTORMS CANNOT BE RULED OUT OVER
CENTRAL NORTH DAKOTA.
DETERMINISTIC MODELS ARE ALL DEPICTING A BREAK IN THE ACTION BEHIND
THE INITIAL STRONG SHORTWAVE THURSDAY AFTERNOON INTO THURSDAY
EVENING...BEFORE THE MAIN UPPER LEVEL LOW LIFTS INTO THE NORTHERN
PLAINS. PRECIPITATION CHANCES THEN INCREASE LATE THURSDAY NIGHT
THROUGH FRIDAY AS THE UPPER LEVEL TROUGH MOVES INTO THE NORTHERN
PLAINS. THERE ARE SOME DIFFERENCES IN QPF BETWEEN THE WETTER ECMWF
AND DRIER GFS/GEM ON FRIDAY. BY THIS TIME THE LOW LEVEL FLOW HAS
SHIFTED NORTH OVER ALL BUT THE FAR SOUTHEAST CWA AND PRECIPITATION
IS EXPECTED TO BE SHOWERS WITH PERHAPS AN ISOLATED THUNDERSTORM.
THUNDERSTORM CHANCES WILL REMAIN OVER THE FAR SOUTHEAST FRIDAY
NIGHT BEHIND THE SURFACE BOUNDARY AND JUST AHEAD OF THE UPPER
LEVEL TROUGH.
UPPER LEVEL RIDGING THEN BUILDS OVER THE REGION BRINGING DRY
CONDITIONS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
TEMPERATURES MAINLY IN THE 70S AHEAD OF THE MAIN COLD FRONT
WEDNESDAY WILL COOL INTO THE 50S AND 60S ACROSS THE AREA BY FRIDAY.
THEN A WARM-UP BACK INTO THE 70S IS EXPECTED BY SUNDAY AND MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1245 PM CDT TUE SEP 24 2013
VFR CONDITIONS WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THE TAF PERIOD. A SOUTHERLY LOW-LEVEL JET UP TO 50 KNOTS
AT 3000 FT WILL SET UP OVER WESTERN NORTH DAKOTA (KDIK-KISN) AFTER
05Z TONIGHT. SINCE SOME OF THIS WIND IS FORECAST TO TRANSFER TO
THE SURFACE...DID NOT INCLUDE NON-CONVECTIVE LOW-LEVEL WIND SHEAR
IN THE KDIK-KISN TAFS. GUSTY SURFACE WINDS UP TO 25 KNOTS WILL
CONTINUE TO SPREAD EAST INTO KMOT-KBIS-KJMS THROUGH WEDNESDAY
MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...KS
LONG TERM...TWH
AVIATION...TM
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1136 AM PDT Tue Sep 24 2013
.SYNOPSIS...
An upper level low will be the dominant weather feature through
much of the week. this will result in rain showers and mountain
snow showers at times through Thursday. Temperatures are expected
to remain well below normal. A warming and drying trend is
expected by the weekend.
&&
.DISCUSSION...
Morning update sent to fine tune Pops and QPF across the forecast
area. Steady stream of showers/rain has setup where
expected...generally from Pendleton to Pullman/Lewiston to Mullan.
Main updates to these areas was to increase QPF amts with some
heavier embedded cells producing 0.05" or more per hour.
Satellite and radar indicate showers filling across the Spokane-
CDA area and even as far northwest as Grand Coulee. Water Vapor
and model data confirm a weak shortwave embedded within the SW
flow and latest HRRR is handling the current situation. This would
suggest showers will continue to fill in across NE WA and Nrn ID
this morning impacting most communities from Republic to Bonners
Ferry. This activity is more scattered in nature so not every
point is a sure bet for rainfall. These showers are moving at a
good rate so most precipitation amts will be less then 0.05".
One other item of note via the latest HRRR is how convective
showers trend after 20z across the entire region. As the trof
settles into the region and 500mb cool...isolated showers will be
possible for just about every location and we have increased even
the lee of the Cascades to slight chance given the lack of a
strong rain shadow. This will need to be monitored closely across
the far southeast as any sunshine could deliver a few hundred
joules of CAPE and potential for isolated storms producing heavy
rainfall. /sb
&&
.AVIATION...
18Z TAFS: Moisture associated with the Low continue to impact the
region. The locations of KEAT and KMWH can expect a continue
clearing as drier air fills in behind this system. This will keep
these locations VFR for the period. A wind shift to the NW is
expected around 11Z on Wednesday as this area will enter the
backside of the trough. The Eastern portion of Washington and ID
Panhandle will be the locations that are greatly impacted by the
moisture. These locations will receive intermittent showers and
ceilings and visibility varying from IFR to MVFR through the early
afternoon hours. As the period progresses, this area will begin to
be influence by the drier air moving into the region. /JDC
&&
.PREV DISCUSSION... /ISSUED 435 AM PDT Tue Sep 24 2013/
SYNOPSIS...
An upper level low will be the dominant weather feature through
much of the week. this will result in rain showers and mountain
snow showers at times through Thursday. Temperatures are expected
to remain well below normal. A warming and drying trend is
expected by the weekend.
DISCUSSION...
Tuesday and Tuesday night: A deep trof of low pressure will
carve into the Pac NW bringing a continuation of below normal
temperatures and unsettled weather. The most persistent area of
precipitation will focus across far southeastern WA and the lower
ID Panhandle however showers will be common across all mountains
surrounding the deep Basin and expanding at times into the West
Plains.
As of 2AM...a line of showers has developed from Mullan to
Pullman/Lewiston to Pendleton very close to where model guidance
indicated over the last 48 hours. Rainfall rates under this band
have generally be around 0.01 to 0.04" per hour. Expect this band
to sit in place until late Tuesday afternoon/early evening with
rainfall amounts spanning from a quarter to half an inch. Locally
higher amounts could be possible over the Camas Prairie;
especially if a few sun-breaks on Tuesday aftn add a convective
element.
Further north into the northeastern mountains of WA...Nrn ID
Panhandle...and Spokane-CDA area...a combination of afternoon
heating...orographics...and especially a shortwave passage during
the afternoon will also bring the threat for widely scattered
showers. This should be a bit more widespread and wetter then
Tuesday given the potential shortwave dynamics and PoPs may need
to be further increased for locations like Spokane...Deer Park...
Coeur D Alene...Sandpoint...and Bonners Ferry. Will be taking a
look at incoming HRRR runs and 12z guidance before deciding.
By this evening and overnight...the upper-level trof will become
firmly entrenched over the Pac NW. Cooling 500mb temperatures
near -25C will promote steepening midlevel lapse rates. A pressure
trof at the surface will begin to weaken and sag south and a cool
high pressure cell slipping into BC will create northerly
gradients across the CWA. This will draw cooler but drier air
southward into the CWA leading to a decreasing shower trend and
potential for locally gusty winds through the Okanogan Valley. A
few of the northern valleys like Republic...Deer Park...and Priest
Lake will be close to the freezing mark while most other lowlands
dip into the upper 30`s to mid 40`s. /sb
Wednesday and Wednesday Night: A closed low continues to pass to
the south of our forecast area but will still present some
unsettled conditions. Best chances for precipitation look to be
Tomorrow Afternoon in the ID Panhandle pushing back west into the
Blue Mtns. Rain showers will be the most likely mode of
precipitation...but a couple claps of thunder cannot be ruled out
with some weak instability in the Panhandle associated with the
trof and closed low. Precip amounts look to be pretty limited with
this system...but convective enhanced showers could bring moderate
showers for localized areas. By Wednesday Night the trof will be
pushing to the east limiting the overall chance for precipitation
in our forecast area.
Winds will be the main factor during this period with gusty
conditions expected Wednesday for the Okanogan Valley. Winds from
the north will channel down the valley enhancing the winds with
gusts in the range of 25 to 30mph. The gusty conditions will continue
down into the western Basin with values more in the 20 to 25mph
range. The winds will be something to monitor throughout the day
for the north-south oriented valleys in north Washington. Temperatures with
the northerly flow will be below normal with upper 50s and low 60s
for most locations minus the deep basin and lower valleys.
Overnight lows will be in the 30s and low 40s for most of the region.
Patchy frost was added for Wednesday Night as cold conditions will
continue into the overnight hours. Main focus for frost will be
the Republic area along with the Priest Lake and Deer Park areas. Fog
will also be present in some valley locations. Any areas with fog
will likely not see the frost as the fog will prevent strong
radiational cooling. Snow levels will remain lower allowing high
elevations in the Cascades and ID Panhandle to see some
flurries...but no lasting accumulations are expected. /Fliehman
Thursday through Monday...Model agreement is good and consistent
Thursday through Saturday. The deep trough over the region will
move off to the east on Thursday but some lingering shower
activity will continue primarily over the Idaho Panhandle and
possibly far eastern Washington. Temperatures will continue to run
below normal and locally breezy north winds especially down the
Okanogan and Purcell trenches will make for a somewhat raw day.
hings are looking up for the end of the week as the trough kicks
east into Montana and makes way for a weak but perceptible upper
level ridge to build over the region for Friday and Saturday. The
polar storm track will remain close by to the north during this
period...so while generally dry conditions are expected with
warming temperatures (up to about normal by Saturday) at least
partly cloudy conditions and a remote threat of some northern
mountain showers will prevail.
Beyond Saturday models begin to diverge and the moderate to high
confidence of the Thursday through Saturday period degrades to
low to moderate confidence in the far reaches of the extended
forecast. The ECMWF is much more aggressive about building a ridge
which implied dry and progressively warmer conditions through the
beginning of the next work week...while the GFS maintains a flat
and weaker ridge subject to flattening by weak transient
disturbances implying significant clouds and a small threat of
showers particularly on Sunday night and Monday with continued
seasonably normal temperatures. In any event it does appear that
models are in agreement that there will be no significant or
organized storm systems through early next week...and in this
regime it is a safe bet that the basin will remain dry while any
threat of showers remains confined to the northern mountains and
Cascades. /Fugazzi
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 59 40 59 42 63 43 / 70 20 20 10 10 10
Coeur d`Alene 56 40 57 41 62 41 / 80 30 30 10 10 10
Pullman 54 39 57 39 62 39 / 100 40 30 20 10 10
Lewiston 59 47 62 48 67 45 / 100 50 40 30 10 10
Colville 62 40 64 40 67 39 / 40 30 20 10 10 10
Sandpoint 53 36 56 36 60 35 / 70 40 30 10 10 10
Kellogg 50 39 54 39 57 39 / 90 50 30 30 20 10
Moses Lake 65 40 67 42 69 43 / 20 20 10 0 0 0
Wenatchee 64 45 66 45 68 47 / 20 20 30 0 0 0
Omak 64 39 67 40 68 42 / 20 20 10 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
256 PM CDT TUE SEP 24 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 256 CDT TUE SEP 24 2013
MINIMAL WEATHER IMPACTS FOR THE AREA UNTIL THE PASSAGE OF COLD
FRONT THIS WEEKEND. FOR THIS AFTERNOON...WATER VAPOR IMAGERY
OVERLAID WITH RAP 500 MB HEIGHTS CONTINUES TO SHOW DECAYING UPPER
LEVEL SHORTWAVE TROUGH ACROSS IOWA...WHICH HAS SPREAD MID/HIGH
LEVEL CLOUDS ACROSS NORTHEAST IOWA INTO SOUTHEAST MINNESOTA. A
DOWNSTREAM UPPER LEVEL RIDGE IS HOLDING STRONG...HELPING TO KEEP
THE DRY AIR MASS IN PLACE...AS SEEN BY THE 24.12Z MPX/GRB
SOUNDINGS.
FOR TONIGHT...THE SURFACE HIGH PRESSURE REMAINS TO OUR EAST AND
OVERALL THE SURFACE PRESSURE FIELDS ARE VERY BAGGY. FORECAST
SOUNDINGS INDICATE THAT THROUGH AROUND 400 MB THE WIND FIELD IS
LESS THAN 10 KTS. AS WAS THE CASE THIS MORNING...EXPECTING PATCHY
DENSE FOG TO DEVELOP ACROSS LOW LYING AREAS OF CENTRAL
WISCONSIN...AND POSSIBLY IN THE MS AND WISCONSIN RIVER VALLEYS.
THE MORE FAVORABLE SET UP EXISTS ACROSS CENTRAL WISCONSIN BUT
COULD NOT RULE PATCHY FOG ACROSS SOUTHEAST MINNESOTA AND NORTHEAST
IOWA DURING THE EARLY MORNING HOURS. OVERALL..THE MAIN LIMITING
FACTOR FOR A MORE WIDESPREAD DENSE EVENT LOOKS TO BE THE LACK OF
SATURATION IN THE BOUNDARY LAYER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 256 CDT TUE SEP 24 2013
SOUTHWESTERLY FLOW SETS UP WEDNESDAY THROUGH THE END OF THE WORK
WEEK AS THE UPPER LEVEL PATTERN BECOMES AMPLIFIED...PROVIDING A FEW
PLEASANT AND TRANQUIL EARLY AUTUMN DAYS. A WESTERN SHORTWAVE TROUGH
BEGINS TO DIG AND MOVE EASTWARD WHILE THE DOWNSTREAM RIDGE BUILDS
ACROSS MUCH OF THE EASTERN CONUS. MOSTLY SUNNY TO SUNNY SKIES
SHOULD PREVAIL EACH DAY...WITH A GRADUAL WARMING IN HIGH
TEMPERATURES. HIGHS RANGING FROM THE LOW TO MID 70S WEDNESDAY WILL
WARM TO THE UPPER 70S TO LOWER 80S BY FRIDAY.
THE 24.12Z MODEL GUIDANCE MORE OR LESS DID NOT CHANGE THE SPEED AND
PROGRESSION OF THE WEEKEND WEATHER SYSTEM...MAYBE A TOUCH FASTER
COMPARED TO THE 00Z AND 06Z RUNS. HOWEVER...THERE IS BETTER
AGREEMENT BETWEEN THE VARIOUS DETERMINISTIC MODELS THAN PREVIOUS
MODEL CYCLES. IT APPEARS THAT THROUGH 15Z SATURDAY THE FORECAST
AREA SHOULD BE DRY WITH INCREASING MID TO HIGH LEVEL CLOUDS.
INITIAL PRECIPITATION BAND LOOKS TO SPREAD IN FROM THE WEST DURING
THE LATE MORNING HOURS...MOVING INTO WESTERN WISCONSIN DURING THE
EARLY/MID AFTERNOON. THE 24.12Z GFS REMAINS A BIT FASTER THAN THE
24.12Z GEM...WHILE THE 24.12Z CONTINUES TO BE SLOWER SOLUTION. THE
24.12Z ECMWF ATTEMPTS TO TURN THE UPPER LEVEL WAVE MORE NEGATIVELY
TILTED SATURDAY AFTERNOON...HELPING TO PUSH THE WHOLE SYSTEM EAST
OF THE AREA BY EARLY SUNDAY...IN LINE WITH ITS FASTER
COUNTERPARTS. THIS SUGGESTS GOOD CONSISTENCY FOR A DRY
SUNDAY...SO HAVE REMOVED CHANCES ALONG AND WEST OF THE MISSISSIPPI
RIVER.
IN THE WAKE OF THIS SYSTEM...ZONAL UPPER LEVEL FLOW WILL PROVIDE A
COUPLE OF DAYS OF NEAR NORMAL TEMPERATURES AND TRANQUIL WEATHER.
INDICATIONS IN THE 24.12Z ECMWF OF AN ACTIVE PACIFIC NORTHWEST JET
SUGGESTS PIECES OF FAST MOVING ENERGY THROUGH THE FLOW...WITH A
COLD FRONTAL PASSAGE TUESDAY NEXT WEEK FOLLOWED BY A REINFORCING
SHOT OF COOLER AIR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1220 PM CDT TUE SEP 24 2013
GENERALLY GOOD VFR CONDITIONS EXPECTED THRU MUCH OF THE NEXT 24-48
HRS. THE ONE CONCERN IS THE RADIATIONAL FOG POTENTIAL CENTERED ON
12Z WED. LIGHT WINDS WILL EXTEND FROM THE SURFACE ON UP THROUGH THE
LOW LEVELS OF THE ATMOSPHERE...WHICH WHEN COMBINED WITH CLEAR SKIES
SHOULD LEAD TO SOME RADIATIONAL FOG DEVELOPMENT LATE TONIGHT. SFC
GRADIENT WINDS LOOK TO BE EAST-SOUTHEAST IN THE 3-5KT RANGE AROUND
12Z WED WITH THE CENTER OF THE SFC HIGH MORE OVER MICHIGAN. THESE
WINDS EXPECTED TO KEEP ANY BR/FG IN ROUGHLY THE 09-14Z TIME-FRAME
MOSTLY MVFR...AND ONLY CARRIED 4-5SM BR AT KLSE/KRST FOR NOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZT
LONG TERM....ZT
AVIATION.....RRS