Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/14/12
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
947 AM MST MON NOV 12 2012
.UPDATE...CURRENT FORECASTS STILL ON TRACK. SHORT WAVE RIDGE TO
MOVE ACROSS THE AREA TODAY. MODELS SHOW WINDS ALOFT WEAKENING THIS
MORNING...WITH THE GUSTY WINDS CONFINED TO THE MOUNTAINS AND HIGHER
FOOTHILLS. THERE MAY BE ENOUGH MIXING FOR SOME OF THE GUSTY WINDS
TO SPREAD ACROSS THE LOWER FOOTHILLS THIS AFTERNOON. FLOW ALOFT
THEN BECOMES SOUTHWEST TONIGHT AHEAD OF AN APPROACHING SHORT WAVE
TROUGH. WRF SYNTHETIC SATELLITE LOOPS INDICATE THE POTENTIAL FOR A WAVE
CLOUD ALONG FOOTHILLS AFTER 02Z.
&&
.AVIATION...CURRENT TAF TRENDS LOOKING REASONABLE...WILL CONTINUE
FOR UPCOMING ISSUANCE. LATEST HRRR AND RUC STILL INDICATING
SOUTHEAST WINDS BY 18Z. HIGH LEVEL CLOUDS TO INCREASE AFTER 02Z
AHEAD OF AN APPROACHING UPPER TROUGH...WITH POTENTIAL FOR A WAVE
CLOUD DEVELOPING ALONG FOOTHILLS.
&&
.PREV DISCUSSION... /ISSUED 410 AM MST MON NOV 12 2012/
SHORT TERM...WEAK UPPER LEVEL RIDGING WILL BE OVER THE AREA
TODAY GIVING WAY TO A DEVELOPING SHORT WAVE TROUGH TONIGHT
TRAVERSING THE AREA TONIGHT. QG VERTICAL VELOCITIES WILL BE
SUBSIDENT TODAY...GRADUALLY CHANGING SIGN AFTER 00Z AND
INTENSIFYING AS THE CORE OF THE ASCENT APPROACHES THE KANSAS
BORDER BY 12Z. NOT MUCH MOISTURE ASSOCIATED WITH THIS SYSTEM BUT
THERE WILL BE AN INCREASE IN CLOUD COVER AS THE SYSTEM PASSES.
FURTHERMORE...SYNTHETIC SATELLITE IMAGERY SUGGESTS THERE WILL BE
SOME MOUNTAIN WAVE CLOUD AROUND TO CONTEND WITH AS WELL.
TEMPERATURES SHOULD BE SEVERAL DEGREES WARMER BOTH TODAY AND
TONIGHT IN ALL AREAS. TYPICAL-FOR-THIS-FLOW-PATTERN ERRATIC WINDS
HAVE BEEN BUFFETING PARTS OF THE FOOTHILLS AND NEARBY PLAINS THIS
MORNING WITH SOME GUSTS IN EXCESS OF 50 MPH IN THE USUALLY WINDIER
SPOTS. THESE GUSTS SHOULD SETTLE DOWN AS THE MORNING WEARS ON.
LONG TERM...MODELS HAVE A WEAK UPPER TROUGH MOVE ACROSS THE CWA
TUESDAY MORNING WITH FAIRLY DECENT NORTHWESTERLY FLOW ALOFT
BEHIND IT. THEN THEY HAVE UPPER RIDGING TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...WITH NEARLY ZONAL FLOW ALOFT. DOWNWARD QG
VERTICAL VELOCITY IS PROGGED FOR THE CWA TUESDAY AND TUESDAY
NIGHT. FOR WEDNESDAY AND WEDNESDAY NIGHT...THE SYNOPTIC SCALE
ENERGY IS BENIGN. THE LOW LEVEL WINDS MAY GET NORTHERLY TUESDAY
AFTERNOON. NORMAL WIND PATTERNS ARE LIKELY TUESDAY NIGHT...WITH
SOUTHWESTERLY DOWNSLOPING ON WEDNESDAY. FOR MOISTURE...THERE IS
SOME IN THE MID AND UPPER LEVELS TUESDAY MORNING. THE REST OF
TUESDAY AND TUESDAY NIGHT ARE PRETTY DRY...MORE SO ON THE NAM. THE
GFS HAS SOME MID AND UPPER LEVEL MOISTURE ON WEDNESDAY AND
WEDNESDAY NIGHT. THE NAM IS WAY DRIER DURING THOSE PERIODS. THE
QPF FIELDS HAVE NO MEASURABLE PRECIPITATION TUESDAY THROUGH
WEDNESDAY EVENING...AND A TAD OVER THE FAR NORTHWEST CORNER OF THE
CWA EARLY THURSDAY MORNING. NO POPS TUESDAY THROUGH WEDNESDAY
NIGHT. FOR TEMPERATURES...TUESDAY`S HIGHS ARE 1-2 C WARMER THAN
MONDAY`S. WEDNESDAY`S HIGHS ARE 2-3 C WARMER THAN TUESDAY`S. FOR
THE LATER DAYS...THURSDAY THROUGH SUNDAY...MODELS HAVE WEST-
NORTHWESTERLY FLOW ALOFT ON THURSDAY. THEN UPPER RIDGING IS
PROGGED ON FRIDAY ACCORDING TO THE GFS...WITH WEAK UPPER TROUGHING
ON THE ECMWF. BOTH HAVE ZONAL FLOW ON SATURDAY. THE GFS HAS A
WEAK UPPER TROUGH ON SUNDAY...WITH ZONAL FLOW TO CONTINUE ON THE
ECMWF. EITHER WAY...THE UPPER TROUGHING PROGGED FOR THE WEEKEND ON
THE LAST TWO 00Z MODELS RUNS FROM BOTH THE GFS AND ECMWF HAVE
SEEMED TO NEARLY DISAPPEAR. WITH JUST SOME MID AND UPPER LEVEL
MOISTURE ON THE GFS...AND WAY LESS ON THE ECMWF AM RELUCTANT TO GO
WITH ANY POPS FOR THE 4 DAYS...BUT WILL LEAVE SOME MINOR VALUES IN
FRIDAY NIGHT THROUGH SATURDAY NIGHT. TEMPERATURES LOOK TO STAY
ABOVE SEASONAL NORMAL.
AVIATION...VFR CEILINGS AND VISIBILITIES TODAY AND TONIGHT AT THE
AREA TERMINALS. WINDS AT KBJC WILL CONTINUE TO BE GUSTY THROUGH
AT LEAST MID MORNING PRIOR TO SETTLING DOWN. KDEN AND KAPA WILL
HAVE LESS WIND THROUGH THE PERIOD WITH KDEN POSSIBLY EXPERIENCING
A FEW PUFFS OF 20 KNOT WESTERLIES THIS MORNING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RJK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1035 PM MST SUN NOV 11 2012
.UPDATE...
ISSUED AT 1035 PM MST SUN NOV 11 2012
STRONG RADIATIONAL COOLING HAS TAKEN HOLD AT KEEO AND KCAG AND
HAVE LOWERED THE MINIMUMS ACROSS THIS AREA. OTHERWISE FORECAST IS
ON TRACK AND APPEARS THAT SNOW HAS ENDED THIS EVENING...ALTHOUGH
SOME TERRAIN HUGGING STRATOCUMULUS STILL LINGER TOWARD THE NRN DIVIDE.
UPDATE ISSUED AT 625 PM MST SUN NOV 11 2012
RADAR LOOP STILL SUGGEST A FEW FLURRIES OR LIGHT SNOW SHOWERS
STILL PERSIST AFTER SUNSET...BUT OBSERVATIONS AND WEB CAMS DO NOT
INDICATE THAT ACCUMULATING SNOW HAS ENDED. THE HRRR MODEL SHOWS
LIGHT PRECIPITATION OVER THE MOUNTAINS OF ROUTT COUNTY WHERE
SPOTTY ACCUMULATIONS OF 1 INCH MAY OCCUR THIS EVENING. THIS DOES
NTO WARRANT THE CONTINUATION OF ANY WARNING OR ADVISORY. ALLOWED
THESE TO EXPIRE AT 6 PM. WITH CLEARING SKIES AND FRESH SNOW
COVER...WILL CHECK WHETHER OVERNIGHT MINIMUMS NEED TO BE ADJUSTED.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 250 PM MST SUN NOV 11 2012
FORECAST THINKING REMAINS ON TRACK AS NORTHWESTERLY
FLOW...INSTABILITY...AND CONVECTION HAVE ALLOWED SNOW SHOWERS TO
CONTINUE TODAY. LOCAL OBSERVATIONS AND WEBCAMS ARE SHOWING
WIDESPREAD SNOWSHOWERS ACROSS MOST MOUNTAIN SITES ALONG THE
CONTINENTAL DIVIDE WITH ANOTHER FEW INCHES OF NEW SNOW NOT OUT OF
THE QUESTION FOR THOSE AREAS. . AFTER SUNSET...STABILITY WILL
INCREASE AND SNOW OUTPUT WILL GRADUALLY END. HGT RISES ARE
EXPECTED EARLY MONDAY MORNING AS A SHORT WAVE RIDGE BUILDS IN FROM
THE WEST.
RADIATIONAL COOLING WILL BE AT A MAXIMUM TONIGHT AS MOSTLY CLEAR
SKIES ARE EXPECTED WHILE THE PREVIOUS DAYS SNOWFALL AND
NORTHWESTERLY FLOW KEPT DAYTIME HIGHS FAIRLY LOW. THIS
COMBINATION MAY PRODUCE SOME RECORD LOWS ACROSS UTAH AND COLORADO
TONIGHT.
A COLD FRONT IS CURRENTLY COMING ASHORE OVER THE PAC NORTHWEST AND
WILL QUICKLY BREAK DOWN OUR RIDGE AS EARLY AS TOMORROW AFTERNOON.
EVEN THROUGH THE RIDGE WILL BE BREAKING DOWN...IT WILL STILL FORCE
THE SYSTEM TO MOVE TO OUR NORTH. THUS...ANY PRECIP WITH THIS
SYSTEM WILL ALSO STAY OVER THE NRN ROCKIES DUE TO THE WEAKENING
RIDGING AND FAVORABLE UPPER LEVEL SUPPORT. AS FAR AS OUR WEATHER
IS CONCERNED THEN...SOME HIGH CLOUDS FOR NORTHERN PARTS OF FORECAST
AREA WHILE MOSTLY SUNNY SKIES EXPECTED FOR MIDDLE AND SOUTHERN
AREAS THROUGH TUESDAY. TEMPERATURES WILL SLOWLY WARM UP WITH
WINDS BECOMING MORE WESTERLY DUE TO ZONAL FLOW SETTING UP.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 250 PM MST SUN NOV 11 2012
A STRONG POLAR VORTEX OVER THE NORTHERN TERRITORIES OF CANADA WILL
CREATE AN EFFECTIVE BLOCK OF HIGH LATITUDE ENERGY THROUGH THE
EXTENDED PERIOD. THIS WILL CONTINUE TO FORCE PACIFIC ENERGY
SOUTHWARD ACROSS THE ALEUTIANS INTO THE EASTERN PACIFIC WHERE A
GENERAL TROUGH WILL BE SETTING UP OFF THE WEST COAST. AS ENERGY
DROPS INTO THE BACK OF THE TROF...ENERGY WILL BE EJECTED OUT OF THE
FRONT ACROSS THE WESTERN STATES. THE BULK OF THESE WAVES WILL BE
SENT ACROSS THE NORTHERN ROCKIES EARLY IN THE WEEK BEFORE THE
WESTERN TROF DEEPENS BY LATE WEEK. THE IMPACT TO OUR CWA WILL BE
MINIMAL THROUGH THURSDAY AS LIFT FROM THE WAVES WILL BE FOCUSED TO
OUR NORTH...AND JUST EXPECT HIGH LEVEL MOISTURE TO BE STREAMING
ALONG OUR NORTHERN BORDER IN THE PROGRESSIVE ZONAL FLOW. CROSS
SECTIONS AND BUFKIT SOUNDINGS SHOW THIS MOISTURE REMAINING JUST
ABOVE MOUNTAIN TOP LEVEL NEAR 600MB. THIS IS NEAR THE DENDRITIC
LAYER SO A FEW PASSING FLURRIES ARE POSSIBLE ATOP THE DIVIDE BUT
WITH MINIMAL LIFT INDICATED THROUGH THIS LAYER EVEN THIS SEEMS
UNLIKELY ATTM. TEMPERATURES LOOK TO POP UP TO NEAR NORMAL ON
WEDNESDAY THOUGH CONTINUED TO GO BELOW GUIDANCE THIS DAY. HIGHS
WILL CONTINUE TO WARM THROUGH THE LATE WEEK PERIOD AS MIXING
INCREASES AND SNOW COVER AT THE LOWER ELEVATIONS DECREASES.
AS FOR THE NEXT STORM SYSTEM THE EURO/GFS OPERATIONAL RUNS ARE IN
BETTER AGREEMENT TODAY IN PUSHING THIS BACK TO THE FRIDAY AND FRIDAY
NIGHT TIME FRAME. MOISTURE TRANSPORT VECTORS IN THE 300-310K RANGE
SHOW THE SOUTHERLY FLOW AHEAD OF THIS SYSTEM PICKING UP SUB TROPICAL
MOISTURE AND BRINGING IT TO THE 4 CORNERS REGION BY SUNRISE ON
FRIDAY. MIXING RATIO/S REACH 3 TO 4 G/KG FRIDAY AFTERNOON DURING
WHICH TIME THE LARGE SCALE ASCENT MOVES OVERHEAD. BOTH MODELS
HOWEVER INDICATE THIS ASCENT WEAKENING AS IT MOVE THROUGH THE GREAT
BASIN...SO QPF OUTPUT CONTINUES TO BE ON THE LOW SIDE. H7
TEMPERATURES INDICATE SNOW LEVEL AGAIN QUITE HIGH ON THE ONSET OF
PRECIPITATION BUT LOWERING THROUGH THE DAY AS THE SYSTEM AND
INSTABILITY MOVES OVERHEAD BY THE EVENING. A SECONDARY WAVE MOVES
THROUGH SATURDAY AND SATURDAY NIGHT BUT WITH COOLER TEMPERATURES
ALOFT AND A MORE NORTHERLY FLOW THE NORTHERN AND CENTRAL MOUNTAINS
MAY DO BETTER AS FAR AS SNOWFALL. OVERALL THIS SYSTEM NOT NEARLY AS
COLD...LEAVING TEMPERATURES AT THE SURFACE NEAR NORMAL THROUGH THE
WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1035 PM MST SUN NOV 11 2012
LOCAL PATCHY FOG ALONG RIVERS OR VALLEY BOTTOMS WILL OCCUR WITH
LOCAL VIS BLO 3SM CIGS AOB BKN010...ESPECIALLY IN THE VICINITY OF
KEGE. AFTER 17Z...ANY FOG OR LOW LYING STRATUS WILL HAVE DISSIPATED.
OTHERWISE WIDESPREAD VFR IS EXPECTED THROUGH THE FORECAST PERIOD.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...TGR
LONG TERM...15
AVIATION...PF
AREA FORECAST DISCUSSION
NWS MIAMI FL
1236 PM EST MON NOV 12 2012
.AVIATION...
PATCHES OF LOW LEVEL MOISTURE WILL AFFECT SOUTH FLORIDA OVER THE
NEXT 24 HOURS IN NE-E WIND FLOW. CURRENT AREA OF HIGHER MOISTURE
MOVING ACROSS SOUTHWEST FLORIDA WITH A BETTER CHANCE OF SHOWERS
AND BRIEF MVFR CONDITIONS AT KAPF, WITH EAST COAST TERMINALS
REMAINING MOSTLY DRY AND VFR THROUGH 00Z. NEXT AREA OF MOISTURE
CURRENTLY OVER THE NORTHERN BAHAMAS SHOULD AFFECT SOUTH FLORIDA
AFTER 00Z WITH VCSH INDICATED AT SE FLORIDA METRO TERMINALS ALONG
WITH POSSIBILITY OF BRIEF MVFR CONDITIONS. SOME DRIER AIR MAY
BEGIN TO MOVE OVER THE REGION AFTER 12Z TUESDAY WITH CONTINUED NE
WIND FLOW. /MOLLEDA
&&
.PREV DISCUSSION... /ISSUED 1006 AM EST MON NOV 12 2012/
UPDATE...
NO SIGNIFICANT CHANGES TO THE CURRENT FORECAST PACKAGE. ALTHOUGH
THE PATCHES OF SHOWERS THAT AFFECTED MAINLY BROWARD COUNTY EARLIER
THIS MORNING ARE CURRENTLY DISSIPATING...RECENT SATELLITE IMAGERY
INDICATES ADDITIONAL PATCHES OF MOISTURE AND CLOUDINESS ACROSS THE
REGION WITH ADDITIONAL ISOLATED PASSING SHOWERS POSSIBLE. THIS IS
CURRENTLY IN THE FORECAST. IN ADDITION THE 12Z SOUNDING INDICATED
THAT SOME ADDITIONAL LOW LEVEL MOISTURE HAS ENTERED THE REGION
WITH THE PWAT CURRENTLY NEAR 1.3 INCHES AND THE PROMINENT LOW
LEVEL INVERSION FROM PREVIOUS DAYS IS SLOWLY ERODING. AN UPPER
LEVEL TROUGH CURRENTLY IN THE NORTHWESTERN GULF IS FORECAST TO
CONTINUE MOVING EASTWARD INTO THE EASTERN GULF TONIGHT WHICH MAY
ALLOW FOR A FEW ISOLATED SHOWERS TONIGHT...ALSO INDICATED IN THE
FORECAST WITH NO CHANGES REQUIRED.
60
PREV DISCUSSION... /ISSUED 651 AM EST MON NOV 12 2012/
UPDATE...
WINDS OF 20-25 KTS OVER ATLANTIC WATERS EARLY THIS MORNING WARRANT
EXTENSION OF SMALL CRAFT ADVISORY THROUGH 18Z. HAVE ADJUSTED GRIDS
ACCORDINGLY.
PREV DISCUSSION... /ISSUED 638 AM EST MON NOV 12 2012/
AVIATION...
SLIGHTLY MORE EXTENSIVE AREAS OF LIGHT TO MODERATE RAIN SHOWERS
ARE PUSHING ONSHORE THE ATLANTIC COAST CURRENTLY. AS A RESULT...WENT
AHEAD AND MOVED UP VCSH MENTION TO THE CURRENT TIME AT ALL EAST
COAST SITES. LATEST HRRR SUGGESTS ADDITIONAL RAIN SHOWERS MOVING
ONSHORE THROUGH THE AFTERNOON HOURS WITH THE CONTINUED EASTERLY
LOW LEVEL FLOW. HEAVIER RAIN SHOWERS COULD REDUCE VISIBILITIES TO
MVFR LEVELS BRIEFLY...HOWEVER PREVAILED VFR THROUGH THE PERIOD.
PREV DISCUSSION... /ISSUED 402 AM EST MON NOV 12 2012/
SHORT TERM /TODAY THROUGH WEDNESDAY/...
STRONG HIGH PRESSURE CENTERED OFFSHORE MID-ATLANTIC UNITED STATES
WILL CONTINUE TO BRING EASTERLY LOW AND MID-LEVEL FLOW TO FLORIDA
PENINSULA. WITH DECENT MOISTURE BEHIND 700 MB INVERSION...A FEW
SHOWERS HAVE SPREAD EASTWARD ACROSS SOUTH FLORIDA LAST EVENING AND
EARLY THIS MORNING...WITH ISOLATED ACTIVITY LIKELY TO PERSIST
THROUGH DAYBREAK. SIMILAR PATTERN ON TAP FOR THIS AFTERNOON AND
TONIGHT...PRESSURE GRADIENT WILL REMAIN TIGHT AS COLD FRONT/LOW
PRESSURE MOVES THROUGH DEEP SOUTH AS ATLANTIC RIDGE GRADUALLY
WEAKENS. THUS...EASTERLY FLOW WILL MAINTAIN. FORECAST SOUNDINGS
SHOULD WEAKENING OF INVERSION...WHICH COULD LEAD TO GREATER SHOWER
COVERAGE THIS EVENING. OUTSIDE OF ANY PRECIPITATION...BREEZY
CONDITIONS EXPECTED ESPECIALLY TODAY MARINE ZONES AND ATLANTIC
BEACHES. EAST WINDS WILL AVERAGE 10 TO 20 MPH AND CREATE A HIGH
RISK FOR RIP CURRENTS ALONG THE ATLANTIC COAST BEACHES.
AFOREMENTIONED COLD FRONT DISSIPATES AS PARENT TROF LIFTS INTO
NORTHEASTERN UNITED STATES. ONLY IMPACT ON SOUTH FLORIDA WILL BE
ENFORCEMENT OF DRIER AIR...LEADING TO LOWER SHOWER CHANCES TUESDAY
AND WEDNESDAY. BREEZY CONDS WILL PERSIST AS WILL SEASONABLY MILD
TEMPERATURES. MAXIMA WILL BE IN UPPER 70S TO LOW 80S...WITH MINIMA
IN MID 60S TO AROUND 70F.
LONG TERM...
ANOTHER COLD FRONT WILL APPROACH TOWARD THE END OF THE WEEK...THOUGH
IT IS NOT LIKELY TO PASS THROUGH SOUTH FLORIDA AND WILL ONLY ACT TO
INCREASE SHOWER CHANCES SLIGHTLY. SEVERAL MODELS DEPICT SHORTWAVE
TROF CLOSING OFF ACROSS SOUTHEASTERN UNITED STATES WITH SURFACE LOW
PRESSURE FORMING ALONG DECAYING BOUNDARY NORTHEAST OF SOUTH FLORIDA
TOWARD THE WEEKEND. CONFIDENCE IN THIS OCCURRING IS LOW AT THE
MOMENT. OVERALL...LOW POPS CONTINUE AND TEMPERATURES REMAIN NEAR
AVERAGE FOR MID-NOVEMBER...THOUGH LOW TEMPERATURES WILL BE A FEW
DEGREES ABOVE NORMAL THROUGH MID-WEEK.
MARINE...
WITH DECENT PRESSURE GRADIENT TODAY...EAST WINDS OF NEAR 20 KTS ARE
EXPECTED FOR THE WATERS...AND A SMALL CRAFT ADVISORY WILL NEED TO BE
EXTENDED FOR WATERS OFF PALM BEACH COUNTY UNTIL 18Z. SMALL CRAFT
SHOULD EXERCISE CAUTION ELSEWHERE IN THE ATLANTIC AND OFFSHORE GULF
WATERS AS WINDS AND SEAS WILL BE SLOW TO SUBSIDE.
FIRE WEATHER...
EAST WINDS OF UP TO 20 MPH ARE FORECAST TODAY...BUT RELATIVE
HUMIDITY WILL BE FAIRLY HIGH...PRECLUDING ANY ENHANCED FIRE THREAT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 82 70 82 69 / 20 20 20 10
FORT LAUDERDALE 82 73 82 71 / 20 20 20 10
MIAMI 82 71 82 70 / 20 20 20 10
NAPLES 84 66 84 64 / 20 20 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH TUESDAY MORNING FOR COASTAL
BROWARD-COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR COASTAL
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-
COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL
EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF THE
BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
PUBLIC/MARINE...60/BD
AVIATION/RADAR/FIRE...59/MOLLEDA
AREA FORECAST DISCUSSION
NWS MIAMI FL
1006 AM EST MON NOV 12 2012
.UPDATE...
NO SIGNIFICANT CHANGES TO THE CURRENT FORECAST PACKAGE. ALTHOUGH
THE PATCHES OF SHOWERS THAT AFFECTED MAINLY BROWARD COUNTY EARLIER
THIS MORNING ARE CURRENTLY DISSIPATING...RECENT SATELLITE IMAGERY
INDICATES ADDITIONAL PATCHES OF MOISTURE AND CLOUDINESS ACROSS THE
REGION WITH ADDITIONAL ISOLATED PASSING SHOWERS POSSIBLE. THIS IS
CURRENTLY IN THE FORECAST. IN ADDITION THE 12Z SOUNDING INDICATED
THAT SOME ADDITIONAL LOW LEVEL MOISTURE HAS ENTERED THE REGION
WITH THE PWAT CURRENTLY NEAR 1.3 INCHES AND THE PROMINENT LOW
LEVEL INVERSION FROM PREVIOUS DAYS IS SLOWLY ERODING. AN UPPER
LEVEL TROUGH CURRENTLY IN THE NORTHWESTERN GULF IS FORECAST TO
CONTINUE MOVING EASTWARD INTO THE EASTERN GULF TONIGHT WHICH MAY
ALLOW FOR A FEW ISOLATED SHOWERS TONIGHT...ALSO INDICATED IN THE
FORECAST WITH NO CHANGES REQUIRED.
60
&&
.PREV DISCUSSION... /ISSUED 651 AM EST MON NOV 12 2012/
UPDATE...
WINDS OF 20-25 KTS OVER ATLANTIC WATERS EARLY THIS MORNING WARRANT
EXTENSION OF SMALL CRAFT ADVISORY THROUGH 18Z. HAVE ADJUSTED GRIDS
ACCORDINGLY.
PREV DISCUSSION... /ISSUED 638 AM EST MON NOV 12 2012/
AVIATION...
SLIGHTLY MORE EXTENSIVE AREAS OF LIGHT TO MODERATE RAIN SHOWERS
ARE PUSHING ONSHORE THE ATLANTIC COAST CURRENTLY. AS A RESULT...WENT
AHEAD AND MOVED UP VCSH MENTION TO THE CURRENT TIME AT ALL EAST
COAST SITES. LATEST HRRR SUGGESTS ADDITIONAL RAIN SHOWERS MOVING
ONSHORE THROUGH THE AFTERNOON HOURS WITH THE CONTINUED EASTERLY
LOW LEVEL FLOW. HEAVIER RAIN SHOWERS COULD REDUCE VISIBILITIES TO
MVFR LEVELS BRIEFLY...HOWEVER PREVAILED VFR THROUGH THE PERIOD.
PREV DISCUSSION... /ISSUED 402 AM EST MON NOV 12 2012/
SHORT TERM /TODAY THROUGH WEDNESDAY/...
STRONG HIGH PRESSURE CENTERED OFFSHORE MID-ATLANTIC UNITED STATES
WILL CONTINUE TO BRING EASTERLY LOW AND MID-LEVEL FLOW TO FLORIDA
PENINSULA. WITH DECENT MOISTURE BEHIND 700 MB INVERSION...A FEW
SHOWERS HAVE SPREAD EASTWARD ACROSS SOUTH FLORIDA LAST EVENING AND
EARLY THIS MORNING...WITH ISOLATED ACTIVITY LIKELY TO PERSIST
THROUGH DAYBREAK. SIMILAR PATTERN ON TAP FOR THIS AFTERNOON AND
TONIGHT...PRESSURE GRADIENT WILL REMAIN TIGHT AS COLD FRONT/LOW
PRESSURE MOVES THROUGH DEEP SOUTH AS ATLANTIC RIDGE GRADUALLY
WEAKENS. THUS...EASTERLY FLOW WILL MAINTAIN. FORECAST SOUNDINGS
SHOULD WEAKENING OF INVERSION...WHICH COULD LEAD TO GREATER SHOWER
COVERAGE THIS EVENING. OUTSIDE OF ANY PRECIPITATION...BREEZY
CONDITIONS EXPECTED ESPECIALLY TODAY MARINE ZONES AND ATLANTIC
BEACHES. EAST WINDS WILL AVERAGE 10 TO 20 MPH AND CREATE A HIGH
RISK FOR RIP CURRENTS ALONG THE ATLANTIC COAST BEACHES.
AFOREMENTIONED COLD FRONT DISSIPATES AS PARENT TROF LIFTS INTO
NORTHEASTERN UNITED STATES. ONLY IMPACT ON SOUTH FLORIDA WILL BE
ENFORCEMENT OF DRIER AIR...LEADING TO LOWER SHOWER CHANCES TUESDAY
AND WEDNESDAY. BREEZY CONDS WILL PERSIST AS WILL SEASONABLY MILD
TEMPERATURES. MAXIMA WILL BE IN UPPER 70S TO LOW 80S...WITH MINIMA
IN MID 60S TO AROUND 70F.
LONG TERM...
ANOTHER COLD FRONT WILL APPROACH TOWARD THE END OF THE WEEK...THOUGH
IT IS NOT LIKELY TO PASS THROUGH SOUTH FLORIDA AND WILL ONLY ACT TO
INCREASE SHOWER CHANCES SLIGHTLY. SEVERAL MODELS DEPICT SHORTWAVE
TROF CLOSING OFF ACROSS SOUTHEASTERN UNITED STATES WITH SURFACE LOW
PRESSURE FORMING ALONG DECAYING BOUNDARY NORTHEAST OF SOUTH FLORIDA
TOWARD THE WEEKEND. CONFIDENCE IN THIS OCCURRING IS LOW AT THE
MOMENT. OVERALL...LOW POPS CONTINUE AND TEMPERATURES REMAIN NEAR
AVERAGE FOR MID-NOVEMBER...THOUGH LOW TEMPERATURES WILL BE A FEW
DEGREES ABOVE NORMAL THROUGH MID-WEEK.
MARINE...
WITH DECENT PRESSURE GRADIENT TODAY...EAST WINDS OF NEAR 20 KTS ARE
EXPECTED FOR THE WATERS...AND A SMALL CRAFT ADVISORY WILL NEED TO BE
EXTENDED FOR WATERS OFF PALM BEACH COUNTY UNTIL 18Z. SMALL CRAFT
SHOULD EXERCISE CAUTION ELSEWHERE IN THE ATLANTIC AND OFFSHORE GULF
WATERS AS WINDS AND SEAS WILL BE SLOW TO SUBSIDE.
FIRE WEATHER...
EAST WINDS OF UP TO 20 MPH ARE FORECAST TODAY...BUT RELATIVE
HUMIDITY WILL BE FAIRLY HIGH...PRECLUDING ANY ENHANCED FIRE THREAT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 82 70 82 69 / 20 20 20 10
FORT LAUDERDALE 82 73 82 71 / 20 20 20 10
MIAMI 82 71 82 70 / 20 20 20 10
NAPLES 84 66 84 64 / 20 20 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH TUESDAY MORNING FOR COASTAL
BROWARD-COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR COASTAL
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-
COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL
EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF THE
BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...60/BD
AVIATION/RADAR...59/RM
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
651 AM EST MON NOV 12 2012
.UPDATE...
WINDS OF 20-25 KTS OVER ATLANTIC WATERS EARLY THIS MORNING WARRANT
EXTENSION OF SMALL CRAFT ADVISORY THROUGH 18Z. HAVE ADJUSTED GRIDS
ACCORDINGLY.
&&
.PREV DISCUSSION... /ISSUED 638 AM EST MON NOV 12 2012/
AVIATION...
SLIGHTLY MORE EXTENSIVE AREAS OF LIGHT TO MODERATE RAIN SHOWERS
ARE PUSHING ONSHORE THE ATLANTIC COAST CURRENTLY. AS A RESULT...WENT
AHEAD AND MOVED UP VCSH MENTION TO THE CURRENT TIME AT ALL EAST
COAST SITES. LATEST HRRR SUGGESTS ADDITIONAL RAIN SHOWERS MOVING
ONSHORE THROUGH THE AFTERNOON HOURS WITH THE CONTINUED EASTERLY
LOW LEVEL FLOW. HEAVIER RAIN SHOWERS COULD REDUCE VISIBILITIES TO
MVFR LEVELS BRIEFLY...HOWEVER PREVAILED VFR THROUGH THE PERIOD.
PREV DISCUSSION... /ISSUED 402 AM EST MON NOV 12 2012/
SHORT TERM /TODAY THROUGH WEDNESDAY/...
STRONG HIGH PRESSURE CENTERED OFFSHORE MID-ATLANTIC UNITED STATES
WILL CONTINUE TO BRING EASTERLY LOW AND MID-LEVEL FLOW TO FLORIDA
PENINSULA. WITH DECENT MOISTURE BEHIND 700 MB INVERSION...A FEW
SHOWERS HAVE SPREAD EASTWARD ACROSS SOUTH FLORIDA LAST EVENING AND
EARLY THIS MORNING...WITH ISOLATED ACTIVITY LIKELY TO PERSIST
THROUGH DAYBREAK. SIMILAR PATTERN ON TAP FOR THIS AFTERNOON AND
TONIGHT...PRESSURE GRADIENT WILL REMAIN TIGHT AS COLD FRONT/LOW
PRESSURE MOVES THROUGH DEEP SOUTH AS ATLANTIC RIDGE GRADUALLY
WEAKENS. THUS...EASTERLY FLOW WILL MAINTAIN. FORECAST SOUNDINGS
SHOULD WEAKENING OF INVERSION...WHICH COULD LEAD TO GREATER SHOWER
COVERAGE THIS EVENING. OUTSIDE OF ANY PRECIPITATION...BREEZY
CONDITIONS EXPECTED ESPECIALLY TODAY MARINE ZONES AND ATLANTIC
BEACHES. EAST WINDS WILL AVERAGE 10 TO 20 MPH AND CREATE A HIGH
RISK FOR RIP CURRENTS ALONG THE ATLANTIC COAST BEACHES.
AFOREMENTIONED COLD FRONT DISSIPATES AS PARENT TROF LIFTS INTO
NORTHEASTERN UNITED STATES. ONLY IMPACT ON SOUTH FLORIDA WILL BE
ENFORCEMENT OF DRIER AIR...LEADING TO LOWER SHOWER CHANCES TUESDAY
AND WEDNESDAY. BREEZY CONDS WILL PERSIST AS WILL SEASONABLY MILD
TEMPERATURES. MAXIMA WILL BE IN UPPER 70S TO LOW 80S...WITH MINIMA
IN MID 60S TO AROUND 70F.
LONG TERM...
ANOTHER COLD FRONT WILL APPROACH TOWARD THE END OF THE WEEK...THOUGH
IT IS NOT LIKELY TO PASS THROUGH SOUTH FLORIDA AND WILL ONLY ACT TO
INCREASE SHOWER CHANCES SLIGHTLY. SEVERAL MODELS DEPICT SHORTWAVE
TROF CLOSING OFF ACROSS SOUTHEASTERN UNITED STATES WITH SURFACE LOW
PRESSURE FORMING ALONG DECAYING BOUNDARY NORTHEAST OF SOUTH FLORIDA
TOWARD THE WEEKEND. CONFIDENCE IN THIS OCCURRING IS LOW AT THE
MOMENT. OVERALL...LOW POPS CONTINUE AND TEMPERATURES REMAIN NEAR
AVERAGE FOR MID-NOVEMBER...THOUGH LOW TEMPERATURES WILL BE A FEW
DEGREES ABOVE NORMAL THROUGH MID-WEEK.
MARINE...
WITH DECENT PRESSURE GRADIENT TODAY...EAST WINDS OF NEAR 20 KTS ARE
EXPECTED FOR THE WATERS...AND A SMALL CRAFT ADVISORY WILL NEED TO BE
EXTENDED FOR WATERS OFF PALM BEACH COUNTY UNTIL 18Z. SMALL CRAFT
SHOULD EXERCISE CAUTION ELSEWHERE IN THE ATLANTIC AND OFFSHORE GULF
WATERS AS WINDS AND SEAS WILL BE SLOW TO SUBSIDE.
FIRE WEATHER...
EAST WINDS OF UP TO 20 MPH ARE FORECAST TODAY...BUT RELATIVE
HUMIDITY WILL BE FAIRLY HIGH...PRECLUDING ANY ENHANCED FIRE THREAT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 82 70 82 69 / 20 20 20 10
FORT LAUDERDALE 82 73 82 71 / 20 20 20 10
MIAMI 82 71 82 70 / 20 20 20 10
NAPLES 84 66 84 64 / 20 20 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH TUESDAY MORNING FOR COASTAL
BROWARD-COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR COASTAL
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-
COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL
EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF THE
BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...23/SK
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
638 AM EST MON NOV 12 2012
.AVIATION...
SLIGHTLY MORE EXTENSIVE AREAS OF LIGHT TO MODERATE RAIN SHOWERS
ARE PUSHING ONSHORE THE ATLANTIC COAST CURRENTLY. AS A RESULT...WENT
AHEAD AND MOVED UP VCSH MENTION TO THE CURRENT TIME AT ALL EAST
COAST SITES. LATEST HRRR SUGGESTS ADDITIONAL RAIN SHOWERS MOVING
ONSHORE THROUGH THE AFTERNOON HOURS WITH THE CONTINUED EASTERLY
LOW LEVEL FLOW. HEAVIER RAIN SHOWERS COULD REDUCE VISIBILITIES TO
MVFR LEVELS BRIEFLY...HOWEVER PREVAILED VFR THROUGH THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 402 AM EST MON NOV 12 2012/
SHORT TERM /TODAY THROUGH WEDNESDAY/...
STRONG HIGH PRESSURE CENTERED OFFSHORE MID-ATLANTIC UNITED STATES
WILL CONTINUE TO BRING EASTERLY LOW AND MID-LEVEL FLOW TO FLORIDA
PENINSULA. WITH DECENT MOISTURE BEHIND 700 MB INVERSION...A FEW
SHOWERS HAVE SPREAD EASTWARD ACROSS SOUTH FLORIDA LAST EVENING AND
EARLY THIS MORNING...WITH ISOLATED ACTIVITY LIKELY TO PERSIST
THROUGH DAYBREAK. SIMILAR PATTERN ON TAP FOR THIS AFTERNOON AND
TONIGHT...PRESSURE GRADIENT WILL REMAIN TIGHT AS COLD FRONT/LOW
PRESSURE MOVES THROUGH DEEP SOUTH AS ATLANTIC RIDGE GRADUALLY
WEAKENS. THUS...EASTERLY FLOW WILL MAINTAIN. FORECAST SOUNDINGS
SHOULD WEAKENING OF INVERSION...WHICH COULD LEAD TO GREATER SHOWER
COVERAGE THIS EVENING. OUTSIDE OF ANY PRECIPITATION...BREEZY
CONDITIONS EXPECTED ESPECIALLY TODAY MARINE ZONES AND ATLANTIC
BEACHES. EAST WINDS WILL AVERAGE 10 TO 20 MPH AND CREATE A HIGH
RISK FOR RIP CURRENTS ALONG THE ATLANTIC COAST BEACHES.
AFOREMENTIONED COLD FRONT DISSIPATES AS PARENT TROF LIFTS INTO
NORTHEASTERN UNITED STATES. ONLY IMPACT ON SOUTH FLORIDA WILL BE
ENFORCEMENT OF DRIER AIR...LEADING TO LOWER SHOWER CHANCES TUESDAY
AND WEDNESDAY. BREEZY CONDS WILL PERSIST AS WILL SEASONABLY MILD
TEMPERATURES. MAXIMA WILL BE IN UPPER 70S TO LOW 80S...WITH MINIMA
IN MID 60S TO AROUND 70F.
LONG TERM...
ANOTHER COLD FRONT WILL APPROACH TOWARD THE END OF THE WEEK...THOUGH
IT IS NOT LIKELY TO PASS THROUGH SOUTH FLORIDA AND WILL ONLY ACT TO
INCREASE SHOWER CHANCES SLIGHTLY. SEVERAL MODELS DEPICT SHORTWAVE
TROF CLOSING OFF ACROSS SOUTHEASTERN UNITED STATES WITH SURFACE LOW
PRESSURE FORMING ALONG DECAYING BOUNDARY NORTHEAST OF SOUTH FLORIDA
TOWARD THE WEEKEND. CONFIDENCE IN THIS OCCURRING IS LOW AT THE
MOMENT. OVERALL...LOW POPS CONTINUE AND TEMPERATURES REMAIN NEAR
AVERAGE FOR MID-NOVEMBER...THOUGH LOW TEMPERATURES WILL BE A FEW
DEGREES ABOVE NORMAL THROUGH MID-WEEK.
MARINE...
WITH DECENT PRESSURE GRADIENT TODAY...EAST WINDS OF NEAR 20 KTS ARE
EXPECTED FOR THE WATERS...AND A SMALL CRAFT ADVISORY WILL NEED TO BE
EXTENDED FOR WATERS OFF PALM BEACH COUNTY UNTIL 18Z. SMALL CRAFT
SHOULD EXERCISE CAUTION ELSEWHERE IN THE ATLANTIC AND OFFSHORE GULF
WATERS AS WINDS AND SEAS WILL BE SLOW TO SUBSIDE.
FIRE WEATHER...
EAST WINDS OF UP TO 20 MPH ARE FORECAST TODAY...BUT RELATIVE
HUMIDITY WILL BE FAIRLY HIGH...PRECLUDING ANY ENHANCED FIRE THREAT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 82 70 82 69 / 20 20 20 10
FORT LAUDERDALE 82 73 82 71 / 20 20 20 10
MIAMI 82 71 82 70 / 20 20 20 10
NAPLES 84 66 84 64 / 20 20 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH TUESDAY MORNING FOR COASTAL
BROWARD-COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR COASTAL
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-
COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL
EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF THE
BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...23/SK
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION...CORRECTED
NWS TAMPA BAY RUSKIN FL
405 AM EST MON NOV 12 2012
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW AN AMPLIFIED
UPPER LEVEL PATTERN OVER THE CONUS THIS MORNING. FROM WEST TO EAST
THE PATTERN CONSISTS OF RIDGING MOVING ASHORE ALONG THE PACIFIC
COAST FOLLOWED DOWNSTREAM BY SHARP/AMPLIFIED TROUGHING THROUGH THE
MIDDLE OF THE CONTINENT...AND FINALLY LARGE SCALE RIDGING OVER THE
EASTERN SEABOARD/WESTERN ATLANTIC. OUR FORECAST AREA RESIDES
DIRECTLY UNDERNEATH THIS UPPER RIDGE AXIS...AND ITS INFLUENCE IS
WELL SAMPLED IN THE 00Z KTBW SOUNDING WITH A DEFINED SUBSIDENCE
INVERSION JUST ABOVE 800MB.
AT THE SURFACE...RIDGING CONTINUES TO EXTEND DOWN THE EASTERN
SEABOARD TO THE FL PENINSULA/EASTERN GULF. FLOW AROUND THIS HIGH IS
PROVIDING A STEADY EASTERLY FLOW THIS MORNING. PERIODS OF LOW LEVEL
CLOUDS ASSOCIATED WITH ATLANTIC MOISTURE ARE TRAVERSING THE STATE
WITHIN THE BOUNDARY LAYER FLOW. TEMPERATURES ARE WARMER COMPARED
TO PAST MORNINGS WITH MOST LOCATIONS STILL HOLDING IN THE
LOWER/MIDDLE 60S.
&&
.SHORT TERM (TODAY THROUGH WEDNESDAY)...
TODAY/TONIGHT...STACKED RIDGING OVER THE FORECAST AREA EARLY THIS
MORNING WILL BREAK DOWN THROUGH THE DAY AS THE UPPER TROUGH MIGRATES
EASTWARD THROUGH THE APPALACHIANS AND THE APPROACH OF AN ASSOCIATED
COLD FRONT WEAKENS THE SURFACE RIDGE. OVERALL TODAYS WEATHER WILL BE
FAIR AND WARM UNDER A MIX OF SUN AND CLOUDS. DO HAVE A 15-20% CHANCE
FOR A FEW ISOLATED LOW TOPPED SHOWERS/SPRINKLES IN THE THE GRIDS
THIS AFTERNOON. MOST GUIDANCE MEMBERS ARE SUPPORTING THE DEVELOPMENT
OF THESE ISOLATED CELLS ASSOCIATED WITH SPEED CONVERGENCE FOCUS
ALONG THE EAST COAST. IMPACT AND DURATIONS OF ANY SHOWERS WILL BE
SMALL. DECENT DIURNAL MIXING AND 850MB TEMPS OF 12-13C SHOULD EASILY
SUPPORT MOST LOCATIONS REACHING 80-83 BY MID AFTERNOON.
A FEW ISOLATED SPRINKLES DURING THE EVENING HOURS WILL DISSIPATE TO
SUPPORT A GENERALLY DRY OVERNIGHT FORECAST. TEMPERATURES WILL AGAIN
BE A BIT ABOVE NORMAL WITH MOST LOCATIONS HOLDING AT OR ABOVE 60
DEGREES. ONLY EXCEPTION WILL BE NORTH OF BROOKSVILLE WHERE READINGS
IN THE MID/UPPER 50S WILL BE POSSIBLE.
TUESDAY...DE-AMPLIFYING UPPER TROUGH WILL QUICKLY PIVOT AWAY FROM
THE REGION. WEAK SURFACE COLD FRONT WILL WASH OUT AS IT MOVES INTO
THE PENINSULA AS STRONG HIGH PRESSURE TO OUR NORTH ONCE AGAIN
TIGHTENS THE GRADIENT. MAY SEE JUST ENOUGH LOW LEVEL FOCUS ALONG
THIS BOUNDARY BEFORE IT IS COMPLETELY DISSIPATED TO SUPPORT ISOLATED
SHOWERS OVER THE NORTHERN HALF OF THE AREA...BUT OTHERWISE TUESDAY
WILL BE DRY AND WARM. TEMPERATURES WILL CLIMB INTO THE MIDDLE 70S TO
AROUND 80 NORTH AND INTO THE LOWER 80S SOUTH UNDER A MIX OF SUN AND
CLOUDS.
WEDNESDAY...GLOBAL GUIDANCE IS SHOWING VARIOUS DEGREES OF SHORTWAVE
ENERGY MOVING ALONG THE NORTHERN GULF COAST. THE GFS IS BROADER IN
SCOPE...WHILE THE 00Z ECMWF HAS A MORE POTENT BUT CONCENTRATED
SHORTWAVE. AT LEAST FOR THE DAYLIGHT HOURS OF WEDNESDAY...EITHER
SOLUTION WOULD HAVE THE BEST SYNOPTIC SUPPORT STAYING TO OUR WEST...
AND HENCE WILL KEEP ITS INFLUENCE OUT OF THE FORECAST REASONING. DO
HAVE A SLIGHT CHANCE POP FOR SHALLOW SHOWERS IN THE GRIDS...BUT
THESE ARE ONCE AGAIN ASSOCIATED WITH THE RENEWED SPEED CONVERGENCE
FOCUS ALONG THE FLORIDA EAST COAST...AND WILL NOT BE OF SIGNIFICANT
IMPACT.
&&
.LONG TERM (THURSDAY THROUGH NEXT SUNDAY)...
THE LONG TERM PERIOD BEGINS WITH AN UPPER LEVEL TROUGH MOVING
THROUGH THE MIDWEST...AND A RIDGE OF HIGH PRESSURE EXITING THE
EASTERN US. 00Z GFS...00Z CMC...AND 00Z ECMWF DECENTLY CONSISTENT
WITH 500 MB TROUGH DIGGING THROUGH EASTERN THIRD OF THE UNITED
STATES AROUND 00Z THURSDAY. IMPACTS TO WEST CENTRAL AND SOUTHWEST
FLORIDA ARE HEAVILY DEPENDENT ON AVAILABLE MOISTURE...THE AMPLITUDE
OF THE TROUGH...AND HOW QUICKLY NORTHWEST FLOW BRINGS IN DRIER AIR
IN THE MID AND UPPER LEVELS TO SHUT OFF PRECIPITATION CHANCES AND
CLEAR SKIES. EXPECT SOME MOISTURE AT THE LOWER LEVELS TO HELP
MODERATE OVERNIGHT TEMPS WHILE SUNNY SKIES TO ALLOW HIGHS IN THE 70S.
MODELS BEING TO DISAGREE HEADING INTO NEXT WEEKEND WITH THE 00Z
ECMWF DEVELOPING A DEEP 500 MB LOW OVER GEORGIA THAT SWINGS OFF THE
SOUTH ATLANTIC COAST AT THE VERY END OR JUST BEYOND THE FORECAST
PERIOD. WHILE THIS SOLUTION WOULD MEAN AT LEAST PRECIPITATION FOR
WEST CENTRAL AND SOUTHWEST FLORIDA...CONFIDENCE IN GUIDANCE THIS FAR
OUT IS NOT HIGH ENOUGH TO INCLUDE RAIN IN THE FORECAST. FOR
COMPARISON...THE 00Z GFS SHOWS A 500 MB SHORTWAVE TROUGH WITHOUT THE
DEEP LOW DEVELOPMENT. THE GFS SOLUTION MAINTAINS THE SYSTEMS IMPACTS
NORTH OF THE AREA...MORE INTO NORTH FLORIDA AND SOUTH GEORGIA. IF
ECMWF SOLUTION STAYS CONSISTENT HEADING FORWARD...NEXT WEEKEND WILL
BE ONE TO WATCH FOR MUCH OF FLORIDA...AND LIKELY THE ATLANTIC
SEABOARD.
&&
.AVIATION...
VFR THROUGH THE PERIOD. AVAILABLE MOISTURE AND CONTINUED EASTERLY
FLOW MAY ALLOW SOME SHOWERS AT FMY...RSW...AND PGD LATER THIS
AFTERNOON CLOSER TO PEAK HEATING. WINDS SHOULD REMAIN EASTERLY AT
ALL SITES.
&&
.MARINE...
LOCAL GRADIENT WILL WEAKEN THROUGH THE DAY WITH WINDS AND SEAS
DECREASING. A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST
TONIGHT AND EARLY TUESDAY BEFORE WASHING OUT OVER THE REGION BY
TUESDAY NIGHT. STRONG HIGH PRESSURE WILL THEN BUILD TO THE NORTH OF
REGION FOR THE MIDWEEK PERIOD RESULTING IN ENHANCED EASTERLY FLOW.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS ARE EXPECTED THE NEXT SEVERAL
DAYS WITH RELATIVE HUMIDITY LEVELS REMAINING ABOVE CRITICAL VALUES.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 81 65 82 64 / 20 10 10 10
FMY 83 65 84 63 / 20 10 10 10
GIF 83 62 84 61 / 20 10 10 10
SRQ 82 63 83 64 / 20 10 10 10
BKV 81 58 83 59 / 20 10 10 10
SPG 80 66 81 66 / 20 10 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...JILLSON/GARCIA
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
405 AM EST MON NOV 11 2012
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW AN AMPLIFIED
UPPER LEVEL PATTERN OVER THE CONUS THIS MORNING. FROM WEST TO EAST
THE PATTERN CONSISTS OF RIDGING MOVING ASHORE ALONG THE PACIFIC
COAST FOLLOWED DOWNSTREAM BY SHARP/AMPLIFIED TROUGHING THROUGH THE
MIDDLE OF THE CONTINENT...AND FINALLY LARGE SCALE RIDGING OVER THE
EASTERN SEABOARD/WESTERN ATLANTIC. OUR FORECAST AREA RESIDES
DIRECTLY UNDERNEATH THIS UPPER RIDGE AXIS...AND ITS INFLUENCE IS
WELL SAMPLED IN THE 00Z KTBW SOUNDING WITH A DEFINED SUBSIDENCE
INVERSION JUST ABOVE 800MB.
AT THE SURFACE...RIDGING CONTINUES TO EXTEND DOWN THE EASTERN
SEABOARD TO THE FL PENINSULA/EASTERN GULF. FLOW AROUND THIS HIGH IS
PROVIDING A STEADY EASTERLY FLOW THIS MORNING. PERIODS OF LOW LEVEL
CLOUDS ASSOCIATED WITH ATLANTIC MOISTURE ARE TRAVERSING THE STATE
WITHIN THE BOUNDARY LAYER FLOW. TEMPERATURES ARE WARMER COMPARED
TO PAST MORNINGS WITH MOST LOCATIONS STILL HOLDING IN THE
LOWER/MIDDLE 60S.
&&
.SHORT TERM (TODAY THROUGH WEDNESDAY)...
TODAY/TONIGHT...STACKED RIDGING OVER THE FORECAST AREA EARLY THIS
MORNING WILL BREAK DOWN THROUGH THE DAY AS THE UPPER TROUGH MIGRATES
EASTWARD THROUGH THE APPALACHIANS AND THE APPROACH OF AN ASSOCIATED
COLD FRONT WEAKENS THE SURFACE RIDGE. OVERALL TODAYS WEATHER WILL BE
FAIR AND WARM UNDER A MIX OF SUN AND CLOUDS. DO HAVE A 15-20% CHANCE
FOR A FEW ISOLATED LOW TOPPED SHOWERS/SPRINKLES IN THE THE GRIDS
THIS AFTERNOON. MOST GUIDANCE MEMBERS ARE SUPPORTING THE DEVELOPMENT
OF THESE ISOLATED CELLS ASSOCIATED WITH SPEED CONVERGENCE FOCUS
ALONG THE EAST COAST. IMPACT AND DURATIONS OF ANY SHOWERS WILL BE
SMALL. DECENT DIURNAL MIXING AND 850MB TEMPS OF 12-13C SHOULD EASILY
SUPPORT MOST LOCATIONS REACHING 80-83 BY MID AFTERNOON.
A FEW ISOLATED SPRINKLES DURING THE EVENING HOURS WILL DISSIPATE TO
SUPPORT A GENERALLY DRY OVERNIGHT FORECAST. TEMPERATURES WILL AGAIN
BE A BIT ABOVE NORMAL WITH MOST LOCATIONS HOLDING AT OR ABOVE 60
DEGREES. ONLY EXCEPTION WILL BE NORTH OF BROOKSVILLE WHERE READINGS
IN THE MID/UPPER 50S WILL BE POSSIBLE.
TUESDAY...DE-AMPLIFYING UPPER TROUGH WILL QUICKLY PIVOT AWAY FROM
THE REGION. WEAK SURFACE COLD FRONT WILL WASH OUT AS IT MOVES INTO
THE PENINSULA AS STRONG HIGH PRESSURE TO OUR NORTH ONCE AGAIN
TIGHTENS THE GRADIENT. MAY SEE JUST ENOUGH LOW LEVEL FOCUS ALONG
THIS BOUNDARY BEFORE IT IS COMPLETELY DISSIPATED TO SUPPORT ISOLATED
SHOWERS OVER THE NORTHERN HALF OF THE AREA...BUT OTHERWISE TUESDAY
WILL BE DRY AND WARM. TEMPERATURES WILL CLIMB INTO THE MIDDLE 70S TO
AROUND 80 NORTH AND INTO THE LOWER 80S SOUTH UNDER A MIX OF SUN AND
CLOUDS.
WEDNESDAY...GLOBAL GUIDANCE IS SHOWING VARIOUS DEGREES OF SHORTWAVE
ENERGY MOVING ALONG THE NORTHERN GULF COAST. THE GFS IS BROADER IN
SCOPE...WHILE THE 00Z ECMWF HAS A MORE POTENT BUT CONCENTRATED
SHORTWAVE. AT LEAST FOR THE DAYLIGHT HOURS OF WEDNESDAY...EITHER
SOLUTION WOULD HAVE THE BEST SYNOPTIC SUPPORT STAYING TO OUR WEST...
AND HENCE WILL KEEP ITS INFLUENCE OUT OF THE FORECAST REASONING. DO
HAVE A SLIGHT CHANCE POP FOR SHALLOW SHOWERS IN THE GRIDS...BUT
THESE ARE ONCE AGAIN ASSOCIATED WITH THE RENEWED SPEED CONVERGENCE
FOCUS ALONG THE FLORIDA EAST COAST...AND WILL NOT BE OF SIGNIFICANT
IMPACT.
&&
.LONG TERM (THURSDAY THROUGH NEXT SUNDAY)...
THE LONG TERM PERIOD BEGINS WITH AN UPPER LEVEL TROUGH MOVING
THROUGH THE MIDWEST...AND A RIDGE OF HIGH PRESSURE EXITING THE
EASTERN US. 00Z GFS...00Z CMC...AND 00Z ECMWF DECENTLY CONSISTENT
WITH 500 MB TROUGH DIGGING THROUGH EASTERN THIRD OF THE UNITED
STATES AROUND 00Z THURSDAY. IMPACTS TO WEST CENTRAL AND SOUTHWEST
FLORIDA ARE HEAVILY DEPENDENT ON AVAILABLE MOISTURE...THE AMPLITUDE
OF THE TROUGH...AND HOW QUICKLY NORTHWEST FLOW BRINGS IN DRIER AIR
IN THE MID AND UPPER LEVELS TO SHUT OFF PRECIPITATION CHANCES AND
CLEAR SKIES. EXPECT SOME MOISTURE AT THE LOWER LEVELS TO HELP
MODERATE OVERNIGHT TEMPS WHILE SUNNY SKIES TO ALLOW HIGHS IN THE 70S.
MODELS BEING TO DISAGREE HEADING INTO NEXT WEEKEND WITH THE 00Z
ECMWF DEVELOPING A DEEP 500 MB LOW OVER GEORGIA THAT SWINGS OFF THE
SOUTH ATLANTIC COAST AT THE VERY END OR JUST BEYOND THE FORECAST
PERIOD. WHILE THIS SOLUTION WOULD MEAN AT LEAST PRECIPITATION FOR
WEST CENTRAL AND SOUTHWEST FLORIDA...CONFIDENCE IN GUIDANCE THIS FAR
OUT IS NOT HIGH ENOUGH TO INCLUDE RAIN IN THE FORECAST. FOR
COMPARISON...THE 00Z GFS SHOWS A 500 MB SHORTWAVE TROUGH WITHOUT THE
DEEP LOW DEVELOPMENT. THE GFS SOLUTION MAINTAINS THE SYSTEMS IMPACTS
NORTH OF THE AREA...MORE INTO NORTH FLORIDA AND SOUTH GEORGIA. IF
ECMWF SOLUTION STAYS CONSISTENT HEADING FORWARD...NEXT WEEKEND WILL
BE ONE TO WATCH FOR MUCH OF FLORIDA...AND LIKELY THE ATLANTIC
SEABOARD.
&&
.AVIATION...
VFR THROUGH THE PERIOD. AVAILABLE MOISTURE AND CONTINUED EASTERLY
FLOW MAY ALLOW SOME SHOWERS AT FMY...RSW...AND PGD LATER THIS
AFTERNOON CLOSER TO PEAK HEATING. WINDS SHOULD REMAIN EASTERLY AT
ALL SITES.
&&
.MARINE...
LOCAL GRADIENT WILL WEAKEN THROUGH THE DAY WITH WINDS AND SEAS
DECREASING. A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST
TONIGHT AND EARLY TUESDAY BEFORE WASHING OUT OVER THE REGION BY
TUESDAY NIGHT. STRONG HIGH PRESSURE WILL THEN BUILD TO THE NORTH OF
REGION FOR THE MIDWEEK PERIOD RESULTING IN ENHANCED EASTERLY FLOW.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS ARE EXPECTED THE NEXT SEVERAL
DAYS WITH RELATIVE HUMIDITY LEVELS REMAINING ABOVE CRITICAL VALUES.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 81 65 82 64 / 20 10 10 10
FMY 83 65 84 63 / 20 10 10 10
GIF 83 62 84 61 / 20 10 10 10
SRQ 82 63 83 64 / 20 10 10 10
BKV 81 58 83 59 / 20 10 10 10
SPG 80 66 81 66 / 20 10 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...JILLSON/GARCIA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1127 PM CST SUN NOV 11 2012
.DISCUSSION...
ISSUED 917 PM CST SUN NOV 11 2012
HAVE ADJUSTED ZONES TO REFLECT PHASE CHANGE ON EDGE OF PRECIP AREA
AND TO SPEED UP CLEARING LATE TONIGHT AND EARLY MONDAY.
FRONT MOVING ACROSS AREA HAS TRANSITIONED INTO A BROAD FRONTAL
ZONE. WIND SHIFT NOW APPROACHING THE INDIANA BORDER...WHILE THE
COLD AIR LINGERS JUST PAST THE ILLINOIS RIVER. AS THE COLD AIR
FUNNELS INTO THE TRAILING EDGE OF THE PRECIP SOME PHASE CHANGE TO
SNOW AND SLEET IS OCCURRING. ACCUMULATIONS MOSTLY LIMITED TO
ELEVATED SURFACES AND GRASS WITH MELTING OCCURRING QUICKLY AFTER
THE PRECIP DIMINISHES.
CLEARING AREA NOW APPROACHING MISSISSIPPI RIVER AND SHOULD PUSH
EAST RELATIVELY QUICKLY GIVEN THE STRONG DVA EVIDENT IN 18Z GFS.
BARKER
&&
.AVIATION...
ISSUED 1127 PM CST SUN NOV 11 2012
IFR CONDITIONS SHOULD CONTINUE AT ALL TAF SITES OVERNIGHT DUE TO
LOTS OF LOW LEVEL MOISTURE BEHIND THE DEPARTING FRONT. SOME SITES
MIGHT SEE MVFR BUT BELIEVE CIGS WILL REMAIN BELOW 1KFT FOR
REMAINDER OF THE NIGHT. SKIES SHOULD THEN CLEAR DURING THE EARLY
MORNING HOURS...STARTING AROUND 10Z AT PIA...AND FINALLY 14Z AT
CMI. THEN CLEAR SKIES SHOULD CONTINUE REMAINDER OF THE TAF PERIOD.
WINDS WILL BE WESTERLY THROUGH THE PERIOD WITH SPEEDS OF 10-15KTS
OVERNIGHT AND TOMORROW...FOLLOWED BY SPEEDS LESS THAN 10KTS
TOMORROW EVENING.
AUTEN
&&
.PREV DISCUSSION...
ISSUED 300 PM CST SUN NOV 11 2012
VIGOROUS SYSTEM APPROACHING CENTRAL AND SOUTHEAST ILLINOIS HAS
RESULTED IN STRONG SOUTHERLY WINDS TODAY...WITH NUMEROUS GUSTS
OVER 40 MPH ACROSS CENTRAL ILLINOIS. A FEW GUSTS OF 50-55 MPH HAVE
BEEN REPORTED AS WELL. COLD FRONT IS ALREADY MAKING STEADY
PROGRESS ACROSS THE FORECAST AREA...CROSSING THE IL RIVER VALLEY
AT THE MOMENT. MAIN FORECAST CONCERN TODAY REVOLVES AROUND
WIND...PRECIPITATION...TEMPERATURES EITHER SIDE OF TONIGHT/S
FROPA. OTHERWISE...RATHER BENIGN...ALBEIT COOLER THAN NORMAL
CONDITIONS...ARE EXPECTED FOR THE NEXT SEVERAL DAYS.
12Z MODELS SHOW SPREAD IN THE MOISTURE/THERMAL FIELDS TONIGHT
INVOF FROPA...AND AGAIN WITH LOWER AMPLITUDE WAVES IN THE MOSTLY
ZONAL FLOW LATER IN THE WEEK. OTHERWISE...AGREEMENT IS GOOD. IN THE
NEAR TERM...PLAN TO USE ACTUAL OBSERVATIONS AND EXTRAPOLATION
RATHER THAN ANY ONE MODEL SOLUTION. FURTHER OUT...AN ENSEMBLE
BLEND SHOULD CONTINUE TO BE THE BEST COURSE OF ACTION UNTIL THE
SPREAD DIMINISHES A BIT.
SHORT TERM...TONIGHT THROUGH WEDNESDAY...FRONT IS CURRENTLY MOVING
MORE QUICKLY THAN MOST OF THE MODELS INDICATED AND SEE NO REASON
WHY THIS WILL NOT CONTINUE TO BE THE CASE. WILL BE CANCELING THE
WESTERN EXTENT OF THE WIND ADVISORY AT 4 PM AS WINDS HAVE BEEN AND
SHOULD CONTINUE TO FALL BELOW ADVISORY LEVELS WITH FROPA. THE BULK
OF THE PRECIPITATION IS STILL EXPECTED ALONG AND BEHIND THE
FRONT...ASSOCIATED WITH STRONG MID LEVEL FRONTOGENESIS AND THE
APPROACH OF THE MAIN UPPER WAVE/JET. WHILE IT STILL LOOKS AS
THOUGH THE BULK OF THE PRECIPITATION SHOULD BE OVER BY THE TIME IT
IS COLD ENOUGH TO SNOW...IT SHOULD BE NOTED THAT THE LATEST NAM
AND RAP HOLD ONTO DEEPER MOISTURE INTO THE OVERNIGHT HOURS AND
WOULD POSE A GREATER SNOW RISK. HOWEVER...UPSTREAM TRENDS CONTINUE
TO AGREE WITH PREVIOUS EXPECTATION THAT THE PRECIPITATION SHOULD
END FOR THE MOST PART BEFORE IT IS COLD ENOUGH FOR SNOW. WE WILL
NEED TO KEEP AN EYE ON THESE TRENDS THOUGH...ESPECIALLY DUE TO THE
FASTER MOVEMENT OF THE FRONT AND ARRIVAL OF THE COLD AIR.
PRECIPITATION WILL BE OVER BY EARLY MONDAY AND A CHILLY AREA OF
HIGH PRESSURE WILL BUILD ACROSS THE AREA INTO MID WEEK. THIS
SURFACE HIGH...ASSOCIATED DRY AIRMASS...AND MOSTLY NEUTRAL UPPER
LEVEL FLOW SHOULD PRODUCE QUIET WEATHER THROUGH THE PERIOD.
LONG TERM...THURSDAY THROUGH SUNDAY...FOR THE MOST PART...THE
MODELS SUPPORT PREDOMINANTLY HIGH PRESSURE AT THE SURFACE AND
ZONAL/NEUTRAL UPPER LEVEL FLOW THROUGH THE WEEKEND. THE LOW LEVEL
FLOW TURNING SOUTHERLY AND GRADUALLY RISING HEIGHTS SUPPORT A SLOW
MODERATION IN TEMPERATURES...ALTHOUGH THEY WILL STILL BE COOL.
SOME SHORT WAVE ENERGY MAY IMPACT THE AREA FROM TIME TO TIME...BUT
THERE IS NOT ENOUGH OF A MODEL CONSENSUS IN THE TIMING/TRACK OF
ANY OF THESE DISCRETE WAVES TO WARRANT CARRYING POPS AT ANY POINT
IN THE EXTENDED RANGE OF THE FORECAST.
BAK
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1121 PM CST SUN NOV 11 2012
.UPDATE 12/06Z AVIATION DISCUSSION...
.SHORT TERM /TONIGHT/...
HAVE UPDATED THE SKY GRIDS FOR INCREASING CLOUDS NORTHWEST WITH
PATCHY STRATUS FOLLOWED BY STRONG UPPER LEVEL SHORTWAVE AND
SECONDARY COLD FRONT DROPPING SOUTH OUT OF MINNESOTA INTO NORTHERN
IOWA BY MORNING. TIMING OF CLOUD COVER WILL PUT LEADING EDGE NEAR
KEST 04 TO 06Z TIME FRAME AND NEAR KMCW AND KALO BY 09-12Z. CLOUDS
MID LEVEL CLOUDS MAY REACH AS FAR SOUTH AS KDSM DURING THE MORNING
HOURS PRIOR TO SYSTEM PULLING EAST BY MIDDAY MOST LOCATIONS.
OVERNIGHT LOWS CONTINUE TO LOOK APPROPRIATE FROM EARLIER AFTERNOON
PACKAGE. STATE FORECAST AND ZONES ALREADY SENT. /REV
.PREVIOUS SHORT TERM /TONIGHT/...
EXTRAPOLATION AND RAP FORCING SUGGEST PRECIP WILL COME TO AN END IN
OUR FORECAST AREA BY 00Z SO NOTHING BEYOND LINGERING LIGHT
RAIN...LIGHT SLEET OR LIGHT SNOW FAR SE LATE THIS AFTERNOON AS COLD
AIR CONTINUES TO DEEPEN. HAVE HAD NO REPORTS OF ANYTHING BEYOND
TOKEN PERIODS OF LIGHT SLEET AS OF YET HOWEVER. CERTAINLY NO
ACCUMULATIONS.
SKIES SHOULD CLEAR THIS EVENING LEADING TO MIN TEMP CONCERNS.
ALTHOUGH MOS SHOWS LOWS IN THE MID TEENS AND LOWER 20S...FORECAST
SOUNDINGS SUGGEST AIRMASS WILL REMAIN MIXED THROUGH THE NIGHT WITH
PERSISTENT NW WINDS. THIS SEEMS REASONABLE SO HAVE BLENDED MOS AND
SOMEWHAT WARMER RAW MODEL TEMPS FOR LOWS.
.LONG TERM /MONDAY THROUGH /...
FEW CONCERNS WITH EXTENDED AS STRONG LOW PRESSURE SYSTEM
CONTINUES TO PUSH NE. BEHIND LOW...UPPER LEVEL FLOW WILL BE MOSTLY
ZONAL. TEMPERATURES WILL REMAIN COLD FOR MONDAY AND MONDAY NIGHT
AS COLD CANADIAN AIR REMAINS IN PLACE BEHIND STRONG COLD
FRONT...WITH LITTLE WARMING FOR MONDAY. HAVE LEFT MENTION OF
ISOLATED FLURRIES ACROSS THE NORTH MONDAY WITH WRAP AROUND OF LOW
CROSSING INTO MN. HAVE DROPPED OVERNIGHT LOWS MONDAY NIGHT AS
SKIES CLEAR AND WINDS BECOME LIGHT EXPECT GOOD RADIATIONAL
COOLING. WILL BE WAA INCREASING ACROSS THE WEST MONDAY NIGHT...BUT
WITH 850 TEMPS STILL BELOW 0C...EXPECT TEMPS TO DROP INTO THE
TEENS AND 20S. A WEAK WAVE WILL PUSH THROUGH FOR WEDNESDAY...WITH
SOUTHERLY FLOW INCREASING. WAVE WILL BRING LITTLE IMPACT WITH LACK
OF MOISTURE. TEMPERATURES WILL CONTINUE TO WARM WITH SOUTHERLY
FLOW THROUGH THE WEEK...AND WILL SEE A RETURN TO SLIGHTLY ABOVE
NORMAL TEMPERATURES FOR THE END OF THE WORK WEEK.
NEXT SYSTEM OF CONCERN REMAINS LOW PRESSURE SYSTEM DEVELOPING
ACROSS WESTERN PLAINS FOR END OF THE PERIOD. MODELS CONTINUE TO
WEAKEN AND SLOW THIS SYSTEM. HAVE CUT BACK ON POPS FOR THE
WEEKEND...KEEPING THEM CONFINED TO THE WEST AND SW FOR SATURDAY
AND SUNDAY. MODELS DO NOT HAVE GOOD AGREEMENT ON TRACK OR
PLACEMENT OF THE LOW HOWEVER...SO THIS COULD CONTINUE TO CHANCE.
STILL LOOKS LIKE BEST CHANCES FOR PRECIPITATION WILL BE BEYOND THE
FORECAST PERIOD NEXT WEEK AS LOW PUSHES EAST.
&&
.AVIATION...12/06Z
UPSTREAM COLD FRONT AND ASSOCIATED STRONG COLD AIR ADVECTION ALOFT
WILL RESULT IN STRATUS MOVING ACROSS ABOUT NORTH HALF OF FORECAST
SITES WITH BKN-OVC035-040 ARRIVING 09-13Z ACROSS THE AREA. WINDS
WILL DIMINISH OVERNIGHT AND THEN INCREASE AGAIN RAPIDLY AFT 15Z MON
WITH MIXING INCREASING THROUGH 21Z WHEN GUSTS WILL BE ABOVE 25KTS
MOST LOCATIONS. COLD AIR ADVECTION AND UPPER LEVEL WAVE WILL EXIT
REGION NEAR 00Z WITH DIMINISHING WINDS AFT 23Z UNDER 12KTS. HIGH
BUILDING INTO REGION AFT 00Z...WITH LIGHT TO VRBL WINDS OVER THE
AREA GRADUALLY BECOMING SOUTH. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...AWB
AVIATION...REV
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1219 AM MST MON NOV 12 2012
.UPDATE...
ISSUED AT 657 PM MST SUN NOV 11 2012
WITH SKIES CLEARING QUICKLY AND WINDS REMAINING LIGHT...TEMPS HAVE
DROPPED QUICKLY ACROSS THE CWA. WHILE DID LOWER TEMPS SEVERAL
DEGREES TO AROUND 10 IN SEVERAL LOCATIONS. TEMPERATURES HAVE
VARIED GREATLY THROUGH THE EVENING WITH TEMP SWINGS AROUND 8
DEGREES NOTED WITHIN THE HOUR AT GLD...SO CONFIDENCE IN REALLY
DROPPING TEMPS TO NEAR CURRENT TD VALUES IS LOW.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 115 PM MST SUN NOV 11 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW LARGE POSITIVELY TILTED
TROUGH OVER THE CENTRAL US WITH ITS AXIS EXTENDING SOUTH ALONG THE
KS/CO STATE LINE AND OVER THE TX/OK PANHANDLES. AT THE SURFACE A
COLD FRONT HAS PUSHED WELL SOUTH AND EAST OF THE CWA...NOW EXTENDING
FROM NORTHERN TX AND THEN BACK TO THE NE ACROSS THE CENTRAL
MISSISSIPPI RIVER VALLEY.
LIGHT SNOW ASSOCIATED WITH H7 FRONTOGENETICAL FORCING HAS ALL BUT
ENDED WITH ONLY A FEW LINGERING FLURRIES OVER OUR SW CWA. THIS
ACTIVITY SHOULD CONTINUE TO DIMINISH THIS AFTERNOON AS SUBSIDENCE AND
A STABLE AIRMASS CONTINUES TO MOVE IN FROM WYOMING AND THE NEBRASKA
PANHANDLE WHERE CLEARING IS ALREADY OBSERVED ON SATELLITE.
WHILE THERE WILL BE A SLIGHT MODERATION OF THE AIRMASS OVER THE CWA
OVERNIGHT WE WILL STILL SEE H85 TEMPS IN THE -4C TO -1C RANGE.
CONSIDERING HOW COLD MANY LOCATIONS GOT EARLY THIS MORNING WITH ONLY
A FEW BREAKS IN CLOUD COVER AND WINDS IN THE 10 TO 20 MPH...TONIGHT
WILL ACTUALLY BE MUCH BETTER FOR COOLING WITH CLEARING SKIES AND
RELATIVELY LIGHT WINDS. RIGHT NOW I HAVE TEMPS RANGING FROM 10 TO
18F ACROSS THE CWA TONIGHT...HOWEVER I WOULD NOT BE SURPRISED IF WE
SEE TEMPERATURES A FEW DEGREES COOLER THAN THIS.
THE AIR MASS WILL CONTINUE TO MODERATE MONDAY WITH HIGH TEMPERATURES
RECOVERING TO THE UPPER 40S/LOW 50S. A VERY DRY AIRMASS WILL REMAIN
IN PLACE WHICH WILL RESULT IN RH VALUES WITHIN RED FLAG CRITERIA.
WINDS APPEAR TO BE MARGINAL SO NO RFW IS PLANNED...HOWEVER THIS MAY
NEED TO BE WATCHED IN THE EVENT THAT WINDS ARE A LITTLE STRONGER.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 1213 AM MST MON NOV 12 2012
SHORTWAVE RIDGING WILL CONTINUE THROUGH FRIDAY WITH DRY CONDITIONS
AND TEMPERATURES NEAR NORMAL. UPPER FLOW TRANSITIONS TO ZONAL FOR
THE WEEKEND WITH A WEAK DISTURBANCE MOVING THROUGH IT. MOISTURE
WILL BE LACKING...SO WILL CARRY ONLY SLIGHT POPS FOR FRIDAY NIGHT
AND SATURDAY IN EASTERN COUNTIES. RIDGE REBUILDS FOR SUNDAY AND
MONDAY AHEAD OF THE NEXT SYSTEM ORGANIZING IN THE DESERT SOUTHWEST
HERALDING A RETURN OF DRY CONDITIONS AND TEMPERATURES NEAR TO
SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1028 PM MST SUN NOV 11 2012
VFR CONDITIONS WILL PREVAIL OVER THE NEXT 24 HOURS WITH WINDS
SHIFTING TO THE WEST OVERNIGHT AND INCREASING TO AROUND 14 KTS
TOMORROW AFTERNOON. A SMALL THREAT FOR PATCHY FOG EXISTS TONIGHT
IN AREAS THAT RAPIDLY COOLED OFF AS DOWNSTREAM DEWPOINTS HIGHER
THAN CURRENT TEMPS IN A FEW LOCATIONS. GIVEN THE OVERALL
PATCHINESS OF COLDER TEMPS AND SFC PATTERN...CONFIDENCE NOT HIGH
ENOUGH TO PUT INTO FORECAST ATTM.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...DR
LONG TERM...024
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1031 PM MST SUN NOV 11 2012
.UPDATE...
ISSUED AT 657 PM MST SUN NOV 11 2012
WITH SKIES CLEARING QUICKLY AND WINDS REMAINING LIGHT...TEMPS HAVE
DROPPED QUICKLY ACROSS THE CWA. WHILE DID LOWER TEMPS SEVERAL
DEGREES TO AROUND 10 IN SEVERAL LOCATIONS. TEMPERATURES HAVE
VARIED GREATLY THROUGH THE EVENING WITH TEMP SWINGS AROUND 8
DEGREES NOTED WITHIN THE HOUR AT GLD...SO CONFIDENCE IN REALLY
DROPPING TEMPS TO NEAR CURRENT TD VALUES IS LOW.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 115 PM MST SUN NOV 11 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW LARGE POSITIVELY TILTED
TROUGH OVER THE CENTRAL US WITH ITS AXIS EXTENDING SOUTH ALONG THE
KS/CO STATE LINE AND OVER THE TX/OK PANHANDLES. AT THE SURFACE A
COLD FRONT HAS PUSHED WELL SOUTH AND EAST OF THE CWA...NOW EXTENDING
FROM NORTHERN TX AND THEN BACK TO THE NE ACROSS THE CENTRAL
MISSISSIPPI RIVER VALLEY.
LIGHT SNOW ASSOCIATED WITH H7 FRONTOGENETICAL FORCING HAS ALL BUT
ENDED WITH ONLY A FEW LINGERING FLURRIES OVER OUR SW CWA. THIS
ACTIVITY SHOULD CONTINUE TO DIMINISH THIS AFTERNOON AS SUBSIDENCE AND
A STABLE AIRMASS CONTINUES TO MOVE IN FROM WYOMING AND THE NEBRASKA
PANHANDLE WHERE CLEARING IS ALREADY OBSERVED ON SATELLITE.
WHILE THERE WILL BE A SLIGHT MODERATION OF THE AIRMASS OVER THE CWA
OVERNIGHT WE WILL STILL SEE H85 TEMPS IN THE -4C TO -1C RANGE.
CONSIDERING HOW COLD MANY LOCATIONS GOT EARLY THIS MORNING WITH ONLY
A FEW BREAKS IN CLOUD COVER AND WINDS IN THE 10 TO 20 MPH...TONIGHT
WILL ACTUALLY BE MUCH BETTER FOR COOLING WITH CLEARING SKIES AND
RELATIVELY LIGHT WINDS. RIGHT NOW I HAVE TEMPS RANGING FROM 10 TO
18F ACROSS THE CWA TONIGHT...HOWEVER I WOULD NOT BE SURPRISED IF WE
SEE TEMPERATURES A FEW DEGREES COOLER THAN THIS.
THE AIR MASS WILL CONTINUE TO MODERATE MONDAY WITH HIGH TEMPERATURES
RECOVERING TO THE UPPER 40S/LOW 50S. A VERY DRY AIRMASS WILL REMAIN
IN PLACE WHICH WILL RESULT IN RH VALUES WITHIN RED FLAG CRITERIA.
WINDS APPEAR TO BE MARGINAL SO NO RFW IS PLANNED...HOWEVER THIS MAY
NEED TO BE WATCHED IN THE EVENT THAT WINDS ARE A LITTLE STRONGER.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 115 PM MST SUN NOV 11 2012
MONDAY NIGHT-WEDNESDAY...ONE UPPER DISTURBANCE MOVES ACROSS THE AREA
TUESDAY WITH NOTHING BUT AN INCREASE IN CLOUDINESS. ANOTHER BATCH OF
CLOUDS MOVE IN WEDNESDAY AFTERNOON AND CONTINUE THROUGH THE NIGHT AS
ANOTHER SYSTEM MOVES THROUGH THE NORTHERN AND CENTRAL PLAINS.
SEASONAL HIGH TEMPERATURES WITH BELOW NORMAL TEMPERATURES MONDAY
NIGHT AND TUESDAY NIGHT...NEAR TO SLIGHTLY ABOVE NORMAL WEDNESDAY
NIGHT.
THURSDAY-SUNDAY...NOT MUCH GOING ON TIL FRIDAY NIGHT THROUGH
SATURDAY NIGHT WHEN A WEATHER SYSTEM MOVES ACROSS THE AREA. NOT MUCH
IN THE WAY OF PRECIPITATION HOWEVER. OTHERWISE SEASONAL TEMPERATURES
FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1028 PM MST SUN NOV 11 2012
VFR CONDITIONS WILL PREVAIL OVER THE NEXT 24 HOURS WITH WINDS
SHIFTING TO THE WEST OVERNIGHT AND INCREASING TO AROUND 14 KTS
TOMORROW AFTERNOON. A SMALL THREAT FOR PATCHY FOG EXISTS TONIGHT
IN AREAS THAT RAPIDLY COOLED OFF AS DOWNSTREAM DEWPOINTS HIGHER
THAN CURRENT TEMPS IN A FEW LOCATIONS. GIVEN THE OVERALL
PATCHINESS OF COLDER TEMPS AND SFC PATTERN...CONFIDENCE NOT HIGH
ENOUGH TO PUT INTO FORECAST ATTM.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...DR
LONG TERM...99
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
133 PM EST MON NOV 12 2012
.Forecast Update...
Updated at 133 PM EST Mon Nov 12 2012
Precipitation and cloud shield quickly continue to push eastward.
Precipitation has ended in areas along and west of I-65. Had
several reports of sleet mixing in with the back edge of the rain
and this correlates fairly well to the dual pol data and to the
ACARS soundings out of KSDF. The rain shield will continue to push
east and some sleet will continue to mix in at times along the back
edge of the precipitation shield. Given the depth of the warm layer
near the surface, it appears that snow will not mix in and sleet
will be most likely. Thus, have removed the mention of snow from
the forecasts. Precipitation still looks to end across the forecast
district by 5 PM EST.
Temperatures continue to fall in the eastern sections with many
locations now into the upper 30s and lower 40s. However, out where
clearing has taken place, we are seeing temperatures warming back up
due to the insolation. So while temperatures in the central
sections will likely fall into the upper 30s early this afternoon, a
small rise back into the lower 40s looks very likely in areas along
and west of I-65. East of I-65, clouds will likely hamper
temperatures so, upper 30s to the lower 40s still look good. The
HRRR runs have captured this as well, so we have trended the updated
forecast close to its output.
Update issued at 1135 AM EST Mon Nov 12 2012
Surface cold front has now crossed the I-75 corridor and is heading
into the coalfields of eastern Kentucky. Post frontal showers
continue across much of the forecast area. Fairly sharp
precipitation cutoff is occurring to our west and is generally along
a line from near Brandenburg to Bowling Green. With the
precipitation shield moving east, it should clear the I-65 corridor
by 1 PM EST and then exit the I-75 corridor between 4-5 PM EST.
Colder air continues to pour in on the back side of the system and
there is a small chance that we could see a little snow mix in with
the rain as the precipitation departs the region. So, have gone
ahead and continued the slight chance of light snow mixing in from
time to time in the latest forecast.
Temperatures are falling rapidly across the eastern sections of the
forecast area, but the temperature drop across the far west has
stabilized a bit in the last couple of hours. In the east, we`ll
see temperatures in the low 50s fall into the lower 40s through the
afternoon hours. In the central sections, temperatures are likely
to cool a little more with readings generally in the upper 30s to
the lower 40s. Upper 30s are common out to our west, but with
clearing skies working in, we may see a small/brief spike in
temperatures later this afternoon. Latest runs of the HRRR seem to
have a good handle and we`ve incorporated the latest runs into the
updated forecast.
Update Issued at 832 AM EST Mon Nov 12 2012
Combination of surface observations and WSR-88D velocity data
indicate that the surface cold front currently stretches from Henry
County southwestward to Monroe County...or just east of the I-65
corridor. So far, we`ve seen temperatures drop about 7 degrees here
at the office in the last 2 hours and it will continue to drop
throughout the morning hours. Widespread showers are occurring
ahead and behind the front, and this rain is expected to continue
throughout the morning hours west of I-65 and then into the
afternoon hours for areas east of I-65.
Temperatures out in the far western CWA have dropped to around 40
degrees. Dual-pol radar data does show the melting layer coming
down quickly aloft and we`re starting to see lowering correlation
coefficients suggesting a change over to snow aloft. However, with
the warm layer near the surface, it is highly doubtful that snow is
reaching the surface at this time. However, with increasing time,
this low-level warm layer will decrease in depth and some light snow
may mix in as the precipitation comes to an end. Current
indications suggest that the best chances of this occurring would be
to our north/northwest where the deeper cold air resides. Depending
on how quick this warm layer scours out, have gone ahead and added
some light snow chances into the forecast for this morning and
afternoon. Precipitation is likely to remain mostly rain, but some
snow flakes mixing in from time to time will be possible...even into
the I-75 corridor later this afternoon. With surface temperatures
expected to remain above freezing, no accumulations are expected.
As mentioned earlier, temperatures are falling rapidly behind the
front. Latest HRRR guidance seems to have the best handle on this,
so we have trended the forecast close to it. We expect temperatures
to fall into the upper 30s/lower 40s later this morning in areas
west of I-65...and this afternoon in areas east of I-65.
Precipitation will also taper off from west to east and we expect
our forecast area to be dry by around 700 PM EST this evening.
&&
.Short Term (Today - Tuesday)...
Issued at 305 AM EST Mon Nov 12 2012
...A Breezy, Rainy Morning with Temperatures Falling into the 40s
Throughout the Day...
At 730Z, a good area of rain was overspreading the area from west to
east ahead of an approaching cold front. The area of rain stretched
back as far as central Illinois with the front position close to the
center of this wide area of rain from north central Indiana to
western Kentucky to central Mississippi. The front was identifiable
at times by a thicker band of reflectivity in radar data. All of
these features will continue to move eastward over our area through
the morning hours. Areas east of I-65 that have not seen rain yet
will likely see the beginning of the rain shield around or before
sunrise. Winds remain gusty this morning between 20-30 mph and will
continue through late morning or early afternoon. Higher gusts
around 30 mph were observed right along the front which will pass
through our region around sunrise and shortly after. Was able to
remove thunder wording from the forecast as the closest lightning
strikes were well to our south over northern Mississippi. Light to
moderate rains are expected to continue through the morning hours
and then taper off from west to east this afternoon. Total QPF
amounts will likely range from 0.5 to 1.25 inches. A few mesonet
locations over western KY have already tallied 0.9 inches of
rainfall with 1-3 more hours of steady rains still to come.
Besides the wind and the rain for the first half of the day,
temperatures will steadily fall into the 40s throughout the day.
Most locations will likely see high temperatures around sunrise this
morning in the mid 40s to upper 50s with declining temperatures
expected behind the cold front for the rest of the day. By early
afternoon, most all locations over southern Indiana and central
Kentucky will see temperatures in the low to mid 40s.
By this evening, all precipitation should be well east of our area.
Sfc high pressure and clearing skies will quickly work into the
area. With very light or calm winds expected tonight and a very
chilly airmass in place, lowered low temps a good amount. Think
that we should bottom out in the mid to upper 20s for lows with our
typical cool spots possibly dipping into the low 20s.
Tuesday will be sunny but chilly. With northerly winds in place and
h85 temps of -1 to -3 degrees C, think that highs will be limited to
mid 40s tops. A few locations may not even make it out of the low
40s.
.Long Term (Tuesday Night - Sunday)
Issued at 308 AM EST Mon Nov 12 2012
Tuesday Night - Wednesday Night...
The upper level pattern will feature zonal flow at the start of the
forecast period, with high pressure in control at the surface.
Medium range models are having trouble with the amplitude of a
shortwave that is progged to pass through Wednesday/Wednesday night.
The more progressive/less amplified solution offered by the GFS/NAM
lack any real moisture return ahead of the system. Therefore, the
forecast would remain dry with only an subtle increase in mid and
upper level clouds. The ECMWF, and to a lesser extent the GEM,
solution really amplifies this feature across the the Gulf Coast
states. Deep moisture advection is much greater ahead of the feature
with this solution and would bring heavier cloud cover across the
south. Will stick with a dry solution to maintain forecast
continuity for now as it has support from the majority of GFS
ensemble members.
Otherwise, sensible weather will feature lows Tuesday night and
Wednesday night mostly in the mid 20s. The coolest decoupled valleys
will likely drop into the lower 20s. These readings will be around
15 degrees below normal for this time of year. Wednesday will only
be slightly warmer than Tuesday as steady northeasterly flow at the
surface continues. Look for highs in the upper 40s to around 50,
about 10 degrees below normal.
Thursday - Sunday...
Thursday will bring continued dry conditions with broad southwest
flow aloft ahead of a developing full latitude and positively tilted
trough. Skies will feature only a few upper level clouds with
slightly warmer temperatures in the 49-54 degree range. Lows
Thursday night will be milder but still slightly below normal, in
the low 30s.
Confidence decreases for the weekend as models diverge due to split
upper level flow, and the handling of a closed low moving into the
Ohio Valley. Have continued to leave the forecast dry with this
feature as there does not appear to be any real deep moisture return
ahead of the system Friday or Saturday. Pops may eventually need
added for late in the weekend as closed low gets caught up in the
southern stream and moves toward the southeast Atlantic Coast. At
this point, Atlantic moisture may begin to wrap westward on the
north side of the system, potentially making it as far west as the
LMK CWA. Will hold off on any pops for now as deep moisture will
likely stay confined to the Appalachian chain and eastward. Highs
should generally be in the low and mid 50s through the weekend, with
lows in the low and mid 30s each night.
&&
.Aviation (18Z TAF Issuance)...
Issued at 1227 PM EST Mon Nov 12 2012
Surface cold front has pushed east of the terminals and post frontal
showers continue over a good portion of the area. Aviation
conditions will improve dramatically this afternoon as cold front
heads on to the east and drier air pushes in from the west.
For KBWG, MVFR ceilings will continue for the next couple of hours
as the back edge of the clouds work towards the terminal. Current
thinking is that skies will clear out by 12/20Z but surface winds
will remain a bit elevated through the remainder of the afternoon.
Sustained winds out of the NW at 10-12 with gusts to 18-20kts will
be possible. Winds will shift to the west and drop off after sunset
with clear skies expected through the overnight hours.
For KSDF, MVFR ceilings will prevail early in the TAF period with
clearing expected to take place after 12/19Z. Clouds look to
scatter out between 12/20-22Z with clear skies expected by 12/23Z.
Surface winds will remain out of the NW at 10-12 with gusts of
17-19kts being possible. Winds will slacken toward sunset with a
shift in direction mainly out of the west. Wind speeds overnight
look to remain at or below 5 kts.
For KLEX, MVFR visibilities and IFR ceilings are expected early in
the TAF period. Light rain will continue through at least 12/20Z
with clearing expected to take place between 12/22-13/00Z. Winds
will remain out of the NW at 15-17 with gusts up to 20-22kts this
afternoon. Those winds will diminish toward sunset and we should
also see a shift in direction to the west after 13/00Z. Clear skies
are expected overnight with wind speeds remaining at or below 5 kts.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........MJ
Short Term.......AMS
Long Term........BJS
Aviation.........MJ
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1227 PM EST MON NOV 12 2012
...Updated Aviation Discussion...
.Forecast Update...
Updated at 1135 AM EST Mon Nov 12 2012
Surface cold front has now crossed the I-75 corridor and is heading
into the coalfields of eastern Kentucky. Post frontal showers
continue across much of the forecast area. Fairly sharp
precipitation cutoff is occurring to our west and is generally along
a line from near Brandenburg to Bowling Green. With the
precipitation shield moving east, it should clear the I-65 corridor
by 1 PM EST and then exit the I-75 corridor between 4-5 PM EST.
Colder air continues to pour in on the back side of the system and
there is a small chance that we could see a little snow mix in with
the rain as the precipitation departs the region. So, have gone
ahead and continued the slight chance of light snow mixing in from
time to time in the latest forecast.
Temperatures are falling rapidly across the eastern sections of the
forecast area, but the temperature drop across the far west has
stabilized a bit in the last couple of hours. In the east, we`ll
see temperatures in the low 50s fall into the lower 40s through the
afternoon hours. In the central sections, temperatures are likely
to cool a little more with readings generally in the upper 30s to
the lower 40s. Upper 30s are common out to our west, but with
clearing skies working in, we may see a small/brief spike in
temperatures later this afternoon. Latest runs of the HRRR seem to
have a good handle and we`ve incorporated the latest runs into the
updated forecast.
Update Issued at 832 AM EST Mon Nov 12 2012
Combination of surface observations and WSR-88D velocity data
indicate that the surface cold front currently stretches from Henry
County southwestward to Monroe County...or just east of the I-65
corridor. So far, we`ve seen temperatures drop about 7 degrees here
at the office in the last 2 hours and it will continue to drop
throughout the morning hours. Widespread showers are occurring
ahead and behind the front, and this rain is expected to continue
throughout the morning hours west of I-65 and then into the
afternoon hours for areas east of I-65.
Temperatures out in the far western CWA have dropped to around 40
degrees. Dual-pol radar data does show the melting layer coming
down quickly aloft and we`re starting to see lowering correlation
coefficients suggesting a change over to snow aloft. However, with
the warm layer near the surface, it is highly doubtful that snow is
reaching the surface at this time. However, with increasing time,
this low-level warm layer will decrease in depth and some light snow
may mix in as the precipitation comes to an end. Current
indications suggest that the best chances of this occurring would be
to our north/northwest where the deeper cold air resides. Depending
on how quick this warm layer scours out, have gone ahead and added
some light snow chances into the forecast for this morning and
afternoon. Precipitation is likely to remain mostly rain, but some
snow flakes mixing in from time to time will be possible...even into
the I-75 corridor later this afternoon. With surface temperatures
expected to remain above freezing, no accumulations are expected.
As mentioned earlier, temperatures are falling rapidly behind the
front. Latest HRRR guidance seems to have the best handle on this,
so we have trended the forecast close to it. We expect temperatures
to fall into the upper 30s/lower 40s later this morning in areas
west of I-65...and this afternoon in areas east of I-65.
Precipitation will also taper off from west to east and we expect
our forecast area to be dry by around 700 PM EST this evening.
&&
.Short Term (Today - Tuesday)...
Issued at 305 AM EST Mon Nov 12 2012
...A Breezy, Rainy Morning with Temperatures Falling into the 40s
Throughout the Day...
At 730Z, a good area of rain was overspreading the area from west to
east ahead of an approaching cold front. The area of rain stretched
back as far as central Illinois with the front position close to the
center of this wide area of rain from north central Indiana to
western Kentucky to central Mississippi. The front was identifiable
at times by a thicker band of reflectivity in radar data. All of
these features will continue to move eastward over our area through
the morning hours. Areas east of I-65 that have not seen rain yet
will likely see the beginning of the rain shield around or before
sunrise. Winds remain gusty this morning between 20-30 mph and will
continue through late morning or early afternoon. Higher gusts
around 30 mph were observed right along the front which will pass
through our region around sunrise and shortly after. Was able to
remove thunder wording from the forecast as the closest lightning
strikes were well to our south over northern Mississippi. Light to
moderate rains are expected to continue through the morning hours
and then taper off from west to east this afternoon. Total QPF
amounts will likely range from 0.5 to 1.25 inches. A few mesonet
locations over western KY have already tallied 0.9 inches of
rainfall with 1-3 more hours of steady rains still to come.
Besides the wind and the rain for the first half of the day,
temperatures will steadily fall into the 40s throughout the day.
Most locations will likely see high temperatures around sunrise this
morning in the mid 40s to upper 50s with declining temperatures
expected behind the cold front for the rest of the day. By early
afternoon, most all locations over southern Indiana and central
Kentucky will see temperatures in the low to mid 40s.
By this evening, all precipitation should be well east of our area.
Sfc high pressure and clearing skies will quickly work into the
area. With very light or calm winds expected tonight and a very
chilly airmass in place, lowered low temps a good amount. Think
that we should bottom out in the mid to upper 20s for lows with our
typical cool spots possibly dipping into the low 20s.
Tuesday will be sunny but chilly. With northerly winds in place and
h85 temps of -1 to -3 degrees C, think that highs will be limited to
mid 40s tops. A few locations may not even make it out of the low
40s.
.Long Term (Tuesday Night - Sunday)
Issued at 308 AM EST Mon Nov 12 2012
Tuesday Night - Wednesday Night...
The upper level pattern will feature zonal flow at the start of the
forecast period, with high pressure in control at the surface.
Medium range models are having trouble with the amplitude of a
shortwave that is progged to pass through Wednesday/Wednesday night.
The more progressive/less amplified solution offered by the GFS/NAM
lack any real moisture return ahead of the system. Therefore, the
forecast would remain dry with only an subtle increase in mid and
upper level clouds. The ECMWF, and to a lesser extent the GEM,
solution really amplifies this feature across the the Gulf Coast
states. Deep moisture advection is much greater ahead of the feature
with this solution and would bring heavier cloud cover across the
south. Will stick with a dry solution to maintain forecast
continuity for now as it has support from the majority of GFS
ensemble members.
Otherwise, sensible weather will feature lows Tuesday night and
Wednesday night mostly in the mid 20s. The coolest decoupled valleys
will likely drop into the lower 20s. These readings will be around
15 degrees below normal for this time of year. Wednesday will only
be slightly warmer than Tuesday as steady northeasterly flow at the
surface continues. Look for highs in the upper 40s to around 50,
about 10 degrees below normal.
Thursday - Sunday...
Thursday will bring continued dry conditions with broad southwest
flow aloft ahead of a developing full latitude and positively tilted
trough. Skies will feature only a few upper level clouds with
slightly warmer temperatures in the 49-54 degree range. Lows
Thursday night will be milder but still slightly below normal, in
the low 30s.
Confidence decreases for the weekend as models diverge due to split
upper level flow, and the handling of a closed low moving into the
Ohio Valley. Have continued to leave the forecast dry with this
feature as there does not appear to be any real deep moisture return
ahead of the system Friday or Saturday. Pops may eventually need
added for late in the weekend as closed low gets caught up in the
southern stream and moves toward the southeast Atlantic Coast. At
this point, Atlantic moisture may begin to wrap westward on the
north side of the system, potentially making it as far west as the
LMK CWA. Will hold off on any pops for now as deep moisture will
likely stay confined to the Appalachian chain and eastward. Highs
should generally be in the low and mid 50s through the weekend, with
lows in the low and mid 30s each night.
&&
.Aviation (18Z TAF Issuance)...
Issued at 1227 PM EST Mon Nov 12 2012
Surface cold front has pushed east of the terminals and post frontal
showers continue over a good portion of the area. Aviation
conditions will improve dramatically this afternoon as cold front
heads on to the east and drier air pushes in from the west.
For KBWG, MVFR ceilings will continue for the next couple of hours
as the back edge of the clouds work towards the terminal. Current
thinking is that skies will clear out by 12/20Z but surface winds
will remain a bit elevated through the remainder of the afternoon.
Sustained winds out of the NW at 10-12 with gusts to 18-20kts will
be possible. Winds will shift to the west and drop off after sunset
with clear skies expected through the overnight hours.
For KSDF, MVFR ceilings will prevail early in the TAF period with
clearing expected to take place after 12/19Z. Clouds look to
scatter out between 12/20-22Z with clear skies expected by 12/23Z.
Surface winds will remain out of the NW at 10-12 with gusts of
17-19kts being possible. Winds will slacken toward sunset with a
shift in direction mainly out of the west. Wind speeds overnight
look to remain at or below 5 kts.
For KLEX, MVFR visibilities and IFR ceilings are expected early in
the TAF period. Light rain will continue through at least 12/20Z
with clearing expected to take place between 12/22-13/00Z. Winds
will remain out of the NW at 15-17 with gusts up to 20-22kts this
afternoon. Those winds will diminish toward sunset and we should
also see a shift in direction to the west after 13/00Z. Clear skies
are expected overnight with wind speeds remaining at or below 5 kts.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........MJ
Short Term.......AMS
Long Term........BJS
Aviation.........MJ
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1135 AM EST MON NOV 12 2012
.Forecast Update...
Updated at 1135 AM EST Mon Nov 12 2012
Surface cold front has now crossed the I-75 corridor and is heading
into the coalfields of eastern Kentucky. Post frontal showers
continue across much of the forecast area. Fairly sharp
precipitation cutoff is occurring to our west and is generally along
a line from near Brandenburg to Bowling Green. With the
precipitation shield moving east, it should clear the I-65 corridor
by 1 PM EST and then exit the I-75 corridor between 4-5 PM EST.
Colder air continues to pour in on the back side of the system and
there is a small chance that we could see a little snow mix in with
the rain as the precipitation departs the region. So, have gone
ahead and continued the slight chance of light snow mixing in from
time to time in the latest forecast.
Temperatures are falling rapidly across the eastern sections of the
forecast area, but the temperature drop across the far west has
stabilized a bit in the last couple of hours. In the east, we`ll
see temperatures in the low 50s fall into the lower 40s through the
afternoon hours. In the central sections, temperatures are likely
to cool a little more with readings generally in the upper 30s to
the lower 40s. Upper 30s are common out to our west, but with
clearing skies working in, we may see a small/brief spike in
temperatures later this afternoon. Latest runs of the HRRR seem to
have a good handle and we`ve incorporated the latest runs into the
updated forecast.
Update Issued at 832 AM EST Mon Nov 12 2012
Combination of surface observations and WSR-88D velocity data
indicate that the surface cold front currently stretches from Henry
County southwestward to Monroe County...or just east of the I-65
corridor. So far, we`ve seen temperatures drop about 7 degrees here
at the office in the last 2 hours and it will continue to drop
throughout the morning hours. Widespread showers are occurring
ahead and behind the front, and this rain is expected to continue
throughout the morning hours west of I-65 and then into the
afternoon hours for areas east of I-65.
Temperatures out in the far western CWA have dropped to around 40
degrees. Dual-pol radar data does show the melting layer coming
down quickly aloft and we`re starting to see lowering correlation
coefficients suggesting a change over to snow aloft. However, with
the warm layer near the surface, it is highly doubtful that snow is
reaching the surface at this time. However, with increasing time,
this low-level warm layer will decrease in depth and some light snow
may mix in as the precipitation comes to an end. Current
indications suggest that the best chances of this occurring would be
to our north/northwest where the deeper cold air resides. Depending
on how quick this warm layer scours out, have gone ahead and added
some light snow chances into the forecast for this morning and
afternoon. Precipitation is likely to remain mostly rain, but some
snow flakes mixing in from time to time will be possible...even into
the I-75 corridor later this afternoon. With surface temperatures
expected to remain above freezing, no accumulations are expected.
As mentioned earlier, temperatures are falling rapidly behind the
front. Latest HRRR guidance seems to have the best handle on this,
so we have trended the forecast close to it. We expect temperatures
to fall into the upper 30s/lower 40s later this morning in areas
west of I-65...and this afternoon in areas east of I-65.
Precipitation will also taper off from west to east and we expect
our forecast area to be dry by around 700 PM EST this evening.
&&
.Short Term (Today - Tuesday)...
Issued at 305 AM EST Mon Nov 12 2012
...A Breezy, Rainy Morning with Temperatures Falling into the 40s
Throughout the Day...
At 730Z, a good area of rain was overspreading the area from west to
east ahead of an approaching cold front. The area of rain stretched
back as far as central Illinois with the front position close to the
center of this wide area of rain from north central Indiana to
western Kentucky to central Mississippi. The front was identifiable
at times by a thicker band of reflectivity in radar data. All of
these features will continue to move eastward over our area through
the morning hours. Areas east of I-65 that have not seen rain yet
will likely see the beginning of the rain shield around or before
sunrise. Winds remain gusty this morning between 20-30 mph and will
continue through late morning or early afternoon. Higher gusts
around 30 mph were observed right along the front which will pass
through our region around sunrise and shortly after. Was able to
remove thunder wording from the forecast as the closest lightning
strikes were well to our south over northern Mississippi. Light to
moderate rains are expected to continue through the morning hours
and then taper off from west to east this afternoon. Total QPF
amounts will likely range from 0.5 to 1.25 inches. A few mesonet
locations over western KY have already tallied 0.9 inches of
rainfall with 1-3 more hours of steady rains still to come.
Besides the wind and the rain for the first half of the day,
temperatures will steadily fall into the 40s throughout the day.
Most locations will likely see high temperatures around sunrise this
morning in the mid 40s to upper 50s with declining temperatures
expected behind the cold front for the rest of the day. By early
afternoon, most all locations over southern Indiana and central
Kentucky will see temperatures in the low to mid 40s.
By this evening, all precipitation should be well east of our area.
Sfc high pressure and clearing skies will quickly work into the
area. With very light or calm winds expected tonight and a very
chilly airmass in place, lowered low temps a good amount. Think
that we should bottom out in the mid to upper 20s for lows with our
typical cool spots possibly dipping into the low 20s.
Tuesday will be sunny but chilly. With northerly winds in place and
h85 temps of -1 to -3 degrees C, think that highs will be limited to
mid 40s tops. A few locations may not even make it out of the low
40s.
.Long Term (Tuesday Night - Sunday)
Issued at 308 AM EST Mon Nov 12 2012
Tuesday Night - Wednesday Night...
The upper level pattern will feature zonal flow at the start of the
forecast period, with high pressure in control at the surface.
Medium range models are having trouble with the amplitude of a
shortwave that is progged to pass through Wednesday/Wednesday night.
The more progressive/less amplified solution offered by the GFS/NAM
lack any real moisture return ahead of the system. Therefore, the
forecast would remain dry with only an subtle increase in mid and
upper level clouds. The ECMWF, and to a lesser extent the GEM,
solution really amplifies this feature across the the Gulf Coast
states. Deep moisture advection is much greater ahead of the feature
with this solution and would bring heavier cloud cover across the
south. Will stick with a dry solution to maintain forecast
continuity for now as it has support from the majority of GFS
ensemble members.
Otherwise, sensible weather will feature lows Tuesday night and
Wednesday night mostly in the mid 20s. The coolest decoupled valleys
will likely drop into the lower 20s. These readings will be around
15 degrees below normal for this time of year. Wednesday will only
be slightly warmer than Tuesday as steady northeasterly flow at the
surface continues. Look for highs in the upper 40s to around 50,
about 10 degrees below normal.
Thursday - Sunday...
Thursday will bring continued dry conditions with broad southwest
flow aloft ahead of a developing full latitude and positively tilted
trough. Skies will feature only a few upper level clouds with
slightly warmer temperatures in the 49-54 degree range. Lows
Thursday night will be milder but still slightly below normal, in
the low 30s.
Confidence decreases for the weekend as models diverge due to split
upper level flow, and the handling of a closed low moving into the
Ohio Valley. Have continued to leave the forecast dry with this
feature as there does not appear to be any real deep moisture return
ahead of the system Friday or Saturday. Pops may eventually need
added for late in the weekend as closed low gets caught up in the
southern stream and moves toward the southeast Atlantic Coast. At
this point, Atlantic moisture may begin to wrap westward on the
north side of the system, potentially making it as far west as the
LMK CWA. Will hold off on any pops for now as deep moisture will
likely stay confined to the Appalachian chain and eastward. Highs
should generally be in the low and mid 50s through the weekend, with
lows in the low and mid 30s each night.
&&
.Aviation (12Z TAF Issuance)...
Issued at 605 AM EST Mon Nov 12 2012
Radar velocity imagery showed the cold front was just west of
BWG/SDF as of 11Z. The front will continue to move east this
morning with expected fropa times of just after 12Z at BWG/SDF and
around 1530Z at LEX. Winds will shift sharply from SSW to WNW when
the front passes through. Rains will continue ahead of and behind
the fropa. With the fropa, we`ll see wind gusts increase to around
25-30 mph with IFR conditions periodically for a few hours along and
behind the front. IFR conditions should improve to MVFR by mid-late
morning at the TAF sites and remain in the MVFR cat through early to
mid afternoon. The back end of the rain should reach the TAF sites
around 17-21Z this afternoon with flight conditions returning to VFR
shortly after.
Tonight skies should go clear with sfc winds becoming light.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........MJ
Short Term.......AMS
Long Term........BJS
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
832 AM EST MON NOV 12 2012
.Forecast Update...
Updated at 832 AM EST Mon Nov 12 2012
Combination of surface observations and WSR-88D velocity data
indicate that the surface cold front currently stretches from Henry
County southwestward to Monroe County...or just east of the I-65
corridor. So far, we`ve seen temperatures drop about 7 degrees here
at the office in the last 2 hours and it will continue to drop
throughout the morning hours. Widespread showers are occurring
ahead and behind the front, and this rain is expected to continue
throughout the morning hours west of I-65 and then into the
afternoon hours for areas east of I-65.
Temperatures out in the far western CWA have dropped to around 40
degrees. Dual-pol radar data does show the melting layer coming
down quickly aloft and we`re starting to see lowering correlation
coefficients suggesting a change over to snow aloft. However, with
the warm layer near the surface, it is highly doubtful that snow is
reaching the surface at this time. However, with increasing time,
this low-level warm layer will decrease in depth and some light snow
may mix in as the precipitation comes to an end. Current
indications suggest that the best chances of this occurring would be
to our north/northwest where the deeper cold air resides. Depending
on how quick this warm layer scours out, have gone ahead and added
some light snow chances into the forecast for this morning and
afternoon. Precipitation is likely to remain mostly rain, but some
snow flakes mixing in from time to time will be possible...even into
the I-75 corridor later this afternoon. With surface temperatures
expected to remain above freezing, no accumulations are expected.
As mentioned earlier, temperatures are falling rapidly behind the
front. Latest HRRR guidance seems to have the best handle on this,
so we have trended the forecast close to it. We expect temperatures
to fall into the upper 30s/lower 40s later this morning in areas
west of I-65...and this afternoon in areas east of I-65.
Precipitation will also taper off from west to east and we expect
our forecast area to be dry by around 700 PM EST this evening.
&&
.Short Term (Today - Tuesday)...
Issued at 305 AM EST Mon Nov 12 2012
...A Breezy, Rainy Morning with Temperatures Falling into the 40s
Throughout the Day...
At 730Z, a good area of rain was overspreading the area from west to
east ahead of an approaching cold front. The area of rain stretched
back as far as central Illinois with the front position close to the
center of this wide area of rain from north central Indiana to
western Kentucky to central Mississippi. The front was identifiable
at times by a thicker band of reflectivity in radar data. All of
these features will continue to move eastward over our area through
the morning hours. Areas east of I-65 that have not seen rain yet
will likely see the beginning of the rain shield around or before
sunrise. Winds remain gusty this morning between 20-30 mph and will
continue through late morning or early afternoon. Higher gusts
around 30 mph were observed right along the front which will pass
through our region around sunrise and shortly after. Was able to
remove thunder wording from the forecast as the closest lightning
strikes were well to our south over northern Mississippi. Light to
moderate rains are expected to continue through the morning hours
and then taper off from west to east this afternoon. Total QPF
amounts will likely range from 0.5 to 1.25 inches. A few mesonet
locations over western KY have already tallied 0.9 inches of
rainfall with 1-3 more hours of steady rains still to come.
Besides the wind and the rain for the first half of the day,
temperatures will steadily fall into the 40s throughout the day.
Most locations will likely see high temperatures around sunrise this
morning in the mid 40s to upper 50s with declining temperatures
expected behind the cold front for the rest of the day. By early
afternoon, most all locations over southern Indiana and central
Kentucky will see temperatures in the low to mid 40s.
By this evening, all precipitation should be well east of our area.
Sfc high pressure and clearing skies will quickly work into the
area. With very light or calm winds expected tonight and a very
chilly airmass in place, lowered low temps a good amount. Think
that we should bottom out in the mid to upper 20s for lows with our
typical cool spots possibly dipping into the low 20s.
Tuesday will be sunny but chilly. With northerly winds in place and
h85 temps of -1 to -3 degrees C, think that highs will be limited to
mid 40s tops. A few locations may not even make it out of the low
40s.
.Long Term (Tuesday Night - Sunday)
Issued at 308 AM EST Mon Nov 12 2012
Tuesday Night - Wednesday Night...
The upper level pattern will feature zonal flow at the start of the
forecast period, with high pressure in control at the surface.
Medium range models are having trouble with the amplitude of a
shortwave that is progged to pass through Wednesday/Wednesday night.
The more progressive/less amplified solution offered by the GFS/NAM
lack any real moisture return ahead of the system. Therefore, the
forecast would remain dry with only an subtle increase in mid and
upper level clouds. The ECMWF, and to a lesser extent the GEM,
solution really amplifies this feature across the the Gulf Coast
states. Deep moisture advection is much greater ahead of the feature
with this solution and would bring heavier cloud cover across the
south. Will stick with a dry solution to maintain forecast
continuity for now as it has support from the majority of GFS
ensemble members.
Otherwise, sensible weather will feature lows Tuesday night and
Wednesday night mostly in the mid 20s. The coolest decoupled valleys
will likely drop into the lower 20s. These readings will be around
15 degrees below normal for this time of year. Wednesday will only
be slightly warmer than Tuesday as steady northeasterly flow at the
surface continues. Look for highs in the upper 40s to around 50,
about 10 degrees below normal.
Thursday - Sunday...
Thursday will bring continued dry conditions with broad southwest
flow aloft ahead of a developing full latitude and positively tilted
trough. Skies will feature only a few upper level clouds with
slightly warmer temperatures in the 49-54 degree range. Lows
Thursday night will be milder but still slightly below normal, in
the low 30s.
Confidence decreases for the weekend as models diverge due to split
upper level flow, and the handling of a closed low moving into the
Ohio Valley. Have continued to leave the forecast dry with this
feature as there does not appear to be any real deep moisture return
ahead of the system Friday or Saturday. Pops may eventually need
added for late in the weekend as closed low gets caught up in the
southern stream and moves toward the southeast Atlantic Coast. At
this point, Atlantic moisture may begin to wrap westward on the
north side of the system, potentially making it as far west as the
LMK CWA. Will hold off on any pops for now as deep moisture will
likely stay confined to the Appalachian chain and eastward. Highs
should generally be in the low and mid 50s through the weekend, with
lows in the low and mid 30s each night.
&&
.Aviation (12Z TAF Issuance)...
Issued at 605 AM EST Mon Nov 12 2012
Radar velocity imagery showed the cold front was just west of
BWG/SDF as of 11Z. The front will continue to move east this
morning with expected fropa times of just after 12Z at BWG/SDF and
around 1530Z at LEX. Winds will shift sharply from SSW to WNW when
the front passes through. Rains will continue ahead of and behind
the fropa. With the fropa, we`ll see wind gusts increase to around
25-30 mph with IFR conditions periodically for a few hours along and
behind the front. IFR conditions should improve to MVFR by mid-late
morning at the TAF sites and remain in the MVFR cat through early to
mid afternoon. The back end of the rain should reach the TAF sites
around 17-21Z this afternoon with flight conditions returning to VFR
shortly after.
Tonight skies should go clear with sfc winds becoming light.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........MJ
Short Term.......AMS
Long Term........BJS
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1003 PM CST SUN NOV 11 2012
.DISCUSSION...
A STRONG COLD FRONT CONTINUES TO MAKE GOOD PROGRESS THIS EVENING
ACROSS NCNTRL LA...EXTENDING FROM NEAR A BQP /BASTROP/...TO MLU...TO
JUST SE OF IER...TO HEMPHILL AND CXO LINE AS OF 0330Z. THIS FRONTAL
POSITION IS ACTUALLY SEVERAL HOURS FASTER THAN THE SHORT TERM PROGS
HAVE IT NOW...WITH EXTRAPOLATION TAKING THIS BNDRY OUT OF THE AREA BY
06Z. TEMPS ARE COOLING QUICKLY WITH THE FROPA...WITH AREAS OF SHRA AND
EMBEDDED TSRA CONTINUING MAINLY BEHIND THE FRONT ALONG THE 850-700MB
TROUGH. REGIONAL PROFILERS IN DEQ AND LEDBETTER TX REVEAL THAT THE
700MB TROUGH REMAINS UPON THEM ATTM...BUT SHOULD GRADUALLY SHIFT E
ACROSS THE AREA OVERNIGHT. HAVE EVEN RECEIVED A COUPLE OF REPORTS OF
SMALL HAIL WITH ONE ISOLATED STORM OVER GREGG/HARRISON/MARION COUNTIES IN
NE TX EARLIER...WITH THIS POTENTIAL PERSISTING WHERE ELEVATED FORCING
REMAINS STRONG AHEAD OF THE LONGWAVE TROUGH BISECTING THE CNTRL
CONUS...AND THE AIR MASS HAVING COOLED SIGNIFICANTLY WITH THE SFC AND
850MB FRONT. ONLY MADE MINOR CHANGES TO POPS TONIGHT...MAINLY TO TAPER
THE RAIN OFF EARLIER ACROSS SE OK/WRN SECTIONS OF E TX...WHILE
MAINTAINING LIKELY/CATEGORICAL POPS FARTHER E FROM DEEP E TX INTO
SCNTRL AR/N LA. FORECAST MIN TEMPS STILL APPEAR WITHIN REACH...AND
ONLY MADE MINOR ADJUSTMENTS TO TEMPS...WITH NEAR FREEZING TEMPS
POSSIBLE ACROSS SE OK WHERE A FREEZE HAS ALREADY OCCURRED EARLIER THIS
FALL SEASON.
THE SHORT TERM PROGS MAY BE A LITTLE SLOWER IN GETTING THE 700MB TROUGH
OUT OF THE REGION EARLY MONDAY MORNING GIVEN CURRENT TRENDS AND THE
NEW RAP RUN...AND HAVE EXTENDED SLIGHT CHANCE AND LOW CHANCE POPS
FARTHER W INTO NCNTRL LA MONDAY MORNING. BUT THIS RAIN SHOULD QUICKLY
EXIT THE REGION BY MIDMORNING WITH THE TROUGH PASSAGE...WITH THE POSTFRONTAL
COULD COVER RAPIDLY DECREASING AS WELL AS COOLER AND MUCH DRIER AIR
FILTERS SE AHEAD OF THE CANADIAN SFC RIDGE ONCE IT BUILDS SE INTO OK/TX.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.AVIATION...
A COLD FRONT FROM KMLU TO KLFK PROGRESSING SOUTHEAST THIS EVENING.
IMPROVING CONDITIONS EXPECTED THROUGH 12/12Z AS SHOWERS AND ISOLATED
THUNDERSTORMS EXIT THE REGION. CEILINGS TO GRADUALLY IMPROVE TO VFR
FROM THE WEST BY 12/12Z ACROSS EAST TEXAS AND 12/18Z ACROSS
LOUISIANA AND ARKANSAS. OTHERWISE...NORTHERLY WINDS AROUND 10 KNOTS
TO PREVAIL THROUGH THE REMAINDER OF THE TERMINAL FORECAST PERIOD.
/05/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 46 62 36 64 37 / 70 10 0 0 0
MLU 51 61 35 61 35 / 80 20 0 0 0
DEQ 33 59 26 60 31 / 20 0 0 0 0
TXK 39 60 34 61 36 / 60 0 0 0 0
ELD 45 58 31 60 34 / 80 10 0 0 0
TYR 38 61 35 62 38 / 20 0 0 0 0
GGG 41 62 33 63 35 / 60 0 0 0 0
LFK 48 66 35 64 37 / 70 10 0 0 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15/05
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
339 PM EST MON NOV 12 2012
.SYNOPSIS...
A STRONG COLD FRONT WITH GUSTY WINDS AND SHOWERS WILL PUSH EAST OF
THE AREA THIS EVENING AND OVERNIGHT. BEHIND THE FRONT...A SHARP
TEMPERATURE DROP CAN BE EXPECTED WITH SNOW SHOWERS BRIEFLY MIXING IN
BEFORE SHOWERS COME TO AN END. HIGH PRESSURE WILL THEN PROVIDE DRY
AND CHILLY CONDITIONS THE REST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH ACROSS
THE UPPER MIDWEST WITH THE UPPER OHIO VALLEY IN A SOUTHWESTERLY FLOW
AHEAD OF THIS FEATURE. AT THE SURFACE...A STRONG COLD FRONT EXTENDS
FROM EASTERN LAKE ERIE INTO EASTERN OHIO. SHOWERS ARE MOSTLY POST-
FRONTAL...EXTENDING BACK INTO CENTRAL OHIO. WITH THE FRONTAL
PASSAGE...WINDS ARE SHIFTING FROM SOUTHERLY TO WESTERLY AND HAVE
BEEN GUSTING AT AROUND 30 MPH.
BEHIND THE FRONT...STRONG COLD AIR ADVECTION IS ALSO QUITE
EVIDENT...WITH TEMPS ALREADY DROPPING INTO THE MID 30S UPSTREAM AND
SNOW MIXING IN WITH SHOWERS ON THE BACK EDGE OF THE PRECIP IN
WESTERN OHIO. AHEAD OF THE FRONT...WESTERN PA...NORTH-CENTRAL
WV...AND WESTERN MD ARE STILL IN ENHANCED WARM AIR ADVECTION...WITH
TEMPS WARMING TO NEAR 70.
THIS EVENING...THE COLD FRONT WILL CONTINUE EASTWARD ACROSS THE
AREA...BRINGING SHOWERS TO THE AREA. WITH THIS IN
MIND...CATEGORICAL POPS ARE FORECAST INTO THE EVENING WITH
STRONG CAA PROVIDING FORCING ALONG THE FRONT. SHOWERS WILL PUSH
FROM EASTERN OHIO INTO WESTERN PA AND NORTHERN WV INTO THE EASTERN
RIDGES BY THIS EVENING. WIND GUSTS UP TO 30KTS WILL BE POSSIBLE
AHEAD OF THE FRONT...DIMINISHING TO 20KTS IN ITS WAKE. A QUARTER
TO A HALF OF AN INCH OF PRECIPITATION IS FORECAST INTO THE EVENING
WITH THE PASSAGE OF THE FRONT AND ITS ASSOCIATED POST-FRONTAL
SHOWERS.
TONIGHT...THE COLD FRONT WILL SLOW AS IT SHIFTS EAST OF THE RIDGES
WITH COLD AIR ADVECTION CONTINUING TO SUPPORT POST-FRONTAL SHOWERS
EARLY. SHOWERS WILL MOSTLY DIMINISH BY 06Z...WITH SNOW SHOWERS
LINGERING ACROSS THE RIDGES INTO DAWN. FOR PRECIP TYPE...RAP
850-700MB 1540M THICKNESS LINE AND -1C 850MB TEMP BOTH SEEM TO
LINE UP FAIRLY WELL WITH CHANGEOVER TO SNOW SHOWERS BEFORE PRECIP
ENDS. THUS...EXPECT A BRIEF CHANGEOVER FOR ZANESVILLE AROUND
00Z...DUBOIS/PITTSBURGH AT 03Z...AND NORTH-CENTRAL WV IF ANY
PRECIP LINGERS BY 06Z. ANY SNOW ACCUMULATION WILL BE LIMITED TO
THE EASTERN RIDGES WITH LESS THAN AN INCH FORECAST. WITH CAA
CONTINUING...850 TEMPS DROP TO AROUND -6C BY DAWN AND LOWS ARE
CLOSE TO A MAV/MET BLEND...IN THE MID TO UPPER 20S ACROSS MUCH OF
THE AREA.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
IN THE WAKE OF THE COLD FRONT...OPERATIONAL MODELS AGREE THAT COLD
AIR ADVECTION WILL CONTINUE ON TUESDAY. A THERMAL TROUGH WILL
REACH THE UPPER OHIO VALLEY TUESDAY NIGHT...BRINGING THE CORE OF
THE COOLEST AIR WITH 850 TEMPS DECREASING TO AROUND -8C. DESPITE CAA
AND TEMP DIFFERENTIAL SUFFICIENT FOR LAKE EFFECT SNOW
SHOWERS...THE FETCH (280-290 DEGREES AT 850MB) AND INVERSION
HEIGHTS (AROUND 5000FT) WILL LIMIT SNOW SHOWERS TO ONLY AREAS
ALONG THE I-80 CORRIDOR ON TUESDAY WITH LITTLE OR NO SNOW
ACCUMULATION EXPECTED. TEMPS WILL STRUGGLE TO REACH THE 40 DEGREE
MARK WITH HIGHS CLOSER TO THE COOLER MAV GUIDANCE.
FOR THE MID-WEEK...THERE IS MODEL AGREEMENT THAT THE UPPER OHIO
VALLEY WILL BE IN GENERALLY A DRY...SOUTHWESTERLY FLOW THROUGH
THIS PERIOD WITH HIGH PRESSURE CROSSING THE AREA. THE THERMAL
TROUGH WILL SHIFT NORTHEAST OF THE AREA ON WEDNESDAY...WITH WEAK
WAA AND MORE ABUNDANT SUNSHINE ALLOWING FOR MODERATING TEMPS INTO
THURSDAY. DESPITE SUNSHINE AND MODERATING TEMPS...HIGHS WILL
STILL WILL BE 5 TO 10 DEGREES BELOW NORMAL THROUGH THIS PERIOD.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL REMAIN NEARLY STATIONARY OVER THE NEW ENGLAND
STATES THROUGH THE WEEKEND...PROVIDING DRY WEATHER AND SLOWLY
MODERATING TEMPERATURES THROUGH MONDAY.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
A STRONG COLD FRONTAL PASSAGE CAN BE EXPECTED ACROSS THE FORECAST
AREA THIS EVENING. THE FRONT SHOULD PUSH EAST OF THE MOUNTAIN
RIDGES BY 02Z. AHEAD OF THE FRONT RAIN SHOWERS AND SOUTHERLY WIND
GUSTS TO 30 KNOTS ARE LIKELY. SHOWERS WILL CONTINUE BEHIND THE FRONT
WITH VFR CONDITIONS LOWERING TO MVFR. WINDS BEHIND THE FRONT WILL
SHIFT TO THE WEST WITH 25 TO 30 KNOT GUSTS INTO THE EVENING HOURS.
AS THE FRONT PUSHES WELL EAST OF THE DISTRICT DURING THE EARLY
MORNING RAIN SHOWERS WILL GIVE WAY TO SOME SNOW FLURRIES BEFORE
ENDING. WINDS WILL DIMINISH TOWARD DAYBREAK TUESDAY.
.OUTLOOK.../TUESDAY THOUGH FRIDAY/...
MVFR MAY STILL BE POSSIBLE FOR KFKL AND KDUJ TUESDAY DUE TO COLD
POOL LAKE-ENHANCED INSTABILITY CLOUDS AND SHOWERS. OTHERWISE VFR
WILL BE PREVALENT ACROSS THE UPPER OHO VALLEY INTO FRIDAY DUE TO
HIGH PRESSURE SUBSIDENCE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
SHORT TERM...WOODRUM
LONG TERM...RSD
AVIATION...RSD
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
139 PM EST MON NOV 12 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE AREA THIS AFTERNOON INTO THE
EVENING...BRINGING GUSTY WINDS AND SHOWERS. A SHARP TEMPERATURE
DROP CAN BE EXPECTED IN THE WAKE OF THE FRONT TONIGHT INTO TUESDAY.
HIGH PRESSURE WILL THEN PROVIDE DRY AND CHILLY CONDITIONS THE
REST OF THE WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AN EARLY AFTERNOON UPDATE HAS BEEN ISSUED TO ACCOUNT FOR THE
LATEST POSITION OF AN APPROACHING COLD FRONT.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH ACROSS
THE UPPER MIDWEST WITH THE UPPER OHIO VALLEY IN A SOUTHWESTERLY
FLOW AHEAD OF THIS FEATURE. AT THE SURFACE...A STRONG COLD FRONT
EXTENDS FROM EASTERN LAKE ERIE TO ZANESVILLE AND INTO SOUTH-
CENTRAL OHIO. THE FRONT IS WELL-DEFINED BY A NARROW ENHANCED BAND ON
RADAR. HOWEVER...A BROAD AREA OF SHOWERS HAS DEVELOPED JUST AHEAD
THE FRONT AND ALSO BEHIND THE FRONT. IN ADDITION...WITH THE
FRONTAL PASSAGE...WINDS ARE SHIFTING FROM SOUTHERLY TO WESTERLY IN
OHIO AND HAVE BEEN GUSTING AT AROUND 35 MPH.
BEHIND THE FRONT...STRONG COLD AIR ADVECTION IS ALSO QUITE
EVIDENT...WITH TEMPS ALREADY DROPPING INTO THE MID 30S UPSTREAM IN
WESTERN OHIO. AHEAD OF THE FRONT...THE UPPER OHIO VALLEY IS IN
ENHANCED WARM AIR ADVECTION...WITH TEMPS WARMING TO NEAR 70 IN
WESTERN PA.
THIS AFTERNOON...THE COLD FRONT WILL CONTINUE EASTWARD ACROSS THE
AREA...BRINGING WIDESPREAD SHOWERS TO THE FORECAST AREA. WITH THIS
IN MIND...100 POPS ARE FORECAST INTO THE EVENING WITH STRONG CAA
PROVIDING FORCING ALONG THE FRONT. SHOWERS WILL PUSH FROM EASTERN
OHIO INTO WESTERN PA AND NORTHERN WV INTO THE EARLY AFTERNOON AND
INTO WESTERN MD BY THIS EVENING. A QUARTER TO A HALF OF AN INCH
OF PRECIPITATION IS FORECAST INTO THE EVENING WITH THE PASSAGE OF THE
FRONT AND ITS ASSOCIATED BROAD AREA OF SHOWERS.
DIURNAL TIMING OF THE APPROACH AND PASSAGE OF THE FRONT ARE
FAVORABLE FOR WINDS GUSTS OF UP TO 35 TO 40 MPH ACROSS MUCH OF
THE AREA. THE RAP INDICATES A 65KT 850MB JET MAX SHIFTING FROM
NORTHERN OHIO INTO LAKE ERIE. WINDS THUS FAR HAVE BEEN MOSTLY SUB-
ADVISORY. HOWEVER...WITH LOCATIONS NORTHWEST OF PITTSBURGH ON THE
PERIPHERY OF THE STRONGEST WINDS WITH THE JET AND THE FRONT
BRINGING WINDS TO THE SURFACE...A LOW-END WIND ADVISORY REMAINS
IN EFFECT FOR A TIER OF COUNTIES NORTHWEST OF PITTSBURGH WITH
BRIEF GUSTS OF 45-50 MPH POSSIBLE.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH WEDNESDAY/...
COLD FRONT WILL MOVE EAST OF THE RIDGES LATE THIS EVENING. SHOWERS
WILL END QUICKLY...GENERALLY AROUND 01Z IN OHIO AND AROUND 04Z
ACROSS THE REST OF THE REGION. PRECIPITATION WILL BE HELD UP A BIT
LONGER IN THE RIDGES. WIND GUSTS WILL WANE DURING THE EVENING
HOURS.
MUCH COLDER AIR WILL RUSH IN BEHIND THE FRONT. THERE LIKELY WILL
BE A BRIEF PERIOD OF EITHER A MIX OF RAIN AND SNOW SHOWERS OR ALL
SNOW SHOWERS ALONG THE BACK EDGE OF THE PRECIPITATION SHIELD.
A MUCH DRIER AIR MASS WILL MOVE IN WITH THE COLDER TEMPS...SO ANY
MIX/SNOW SHOWERS WILL NOT LAST LONG. THE ATMOSPHERE IS NOT SETTING
UP WELL FOR MUCH IF ANY LAKE ENHANCED/ EFFECT SNOW. WINDS NEVER
LINE UP...WITH A GOOD DEAL OF DIRECTIONAL SHEAR BETWEEN THE SFC
AND 700MB. ADDITIONALLY...THE VERY DRY AIR MASS WILL LOWER
INVERSIONS. THERE LIKELY WILL BE SOME UP-SLOPE SNOW SHOWERS OVER
THE HIGHEST RIDGES LATE TONIGHT...BUT THESE WILL BE LIGHT AND
SHORT LIVED AS THE COLDEST AIR NEVER MAKES IT THAT FAR SOUTH.
COLDER DAY ON TUESDAY...WITH SOME LIKE EFFECT SNOW SHOWERS
POSSIBLE ACROSS THE FAR NORTH. CLOUD COVER TUESDAY WILL BE
TRICKY...AS ANOTHER SHOT OF COLD AIR MOVES IN DURING THE
AFTERNOON. FORECAST SOUNDINGS ARE SHOWING A PRETTY DRY ATMOSPHERE
ACROSS MUCH OF THE REGION UNTIL VERY LATE IN THE DAY.
SFC HIGH WILL MOVE THROUGH ON WEDNESDAY...AS THE COLD AIR IS
PUSHED NORTHWARD.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL REMAIN NEARLY STATIONARY OVER THE NEW ENGLAND
STATES THROUGH THE WEEKEND...PROVIDING DRY WEATHER AND SLOWLY
MODERATING TEMPERATURES INTO SUNDAY.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
A STRONG COLD FRONTAL PASSAGE CAN BE EXPECTED ACROSS THE FORECAST
AREA THIS EVENING. THE FRONT SHOULD PUSH EAST OF THE MOUNTAIN
RIDGES BY 02Z. AHEAD OF THE FRONT RAIN SHOWERS AND SOUTHERLY WIND
GUSTS TO 30 KNOTS ARE LIKELY. SHOWERS WILL CONTINUE BEHIND THE FRONT
WITH VFR CONDITIONS LOWERING TO MVFR. WINDS BEHIND THE FRONT WILL
SHIFT TO THE WEST WITH 25 TO 30 KNOT GUSTS INTO THE EVENING HOURS.
AS THE FRONT PUSHES WELL EAST OF THE DISTRICT DURING THE EARLY
MORNING RAIN SHOWERS WILL GIVE WAY TO SOME SNOW FLURRIES BEFORE
ENDING. WINDS WILL DIMINISH TOWARD DAYBREAK TUESDAY.
.OUTLOOK.../TUESDAY THOUGH FRIDAY/...
MVFR MAY STILL BE POSSIBLE FOR KFKL AND KDUJ TUESDAY DUE TO COLD
POOL LAKE-ENHANCED INSTABILITY CLOUDS AND SHOWERS. OTHERWISE VFR
WILL BE PREVALENT ACROSS THE UPPER OHO VALLEY INTO FRIDAY DUE TO
HIGH PRESSURE SUBSIDENCE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR OHZ039>041-048.
PA...WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR PAZ007-008-013.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1132 AM EST MON NOV 12 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE AREA THIS AFTERNOON INTO THE
EVENING...BRINGING GUSTY WINDS AND SHOWERS. A SHARP TEMPERATURE
DROP CAN BE EXPECTED IN THE WAKE OF THE FRONT TONIGHT INTO TUESDAY.
HIGH PRESSURE WILL THEN PROVIDE DRY AND CHILLY CONDITIONS THE
REST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A FORECAST UPDATE HAS BEEN ISSUED THIS MORNING TO INCREASE WINDS
NORTHWEST OF PITTSBURGH AND ACCOUNT FOR THE LATEST TRENDS AHEAD OF
A COLD FRONT.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH ACROSS
THE UPPER MIDWEST WITH THE UPPER OHIO VALLEY IN A SOUTHWESTERLY
FLOW AHEAD OF THIS FEATURE. AT THE SURFACE...A STRONG COLD FRONT
EXTENDS FROM LAKE ERIE SOUTH-SOUTHWESTWARD TO COLUMBUS AND INTO
SOUTH-CENTRAL OHIO. THE FRONT IS WELL-DEFINED BY A NARROW FRONTAL
BAND ON RADAR. HOWEVER...A BROAD AREA OF SHOWERS EXTENDS BOTH AHEAD
AND BEHIND THE FRONT. IN ADDITION...WITH THE FRONTAL PASSAGE...WINDS
ARE SHIFTING FROM SOUTHERLY TO WESTERLY IN OHIO AND HAVE BEEN
GUSTING AT AROUND 40 MPH.
BEHIND THE FRONT...STRONG COLD AIR ADVECTION IS ALSO QUITE
EVIDENT...WITH TEMPS ALREADY DROPPING INTO THE MID 30S UPSTREAM IN
INDIANA. AHEAD OF THE FRONT...THE UPPER OHIO VALLEY IS IN ENHANCED
WARM AIR ADVECTION,..WITH TEMPS WARMING TO NEAR 70 SOUTH OF
PITTSBURGH.
TODAY...THE COLD FRONT WILL CONTINUE EASTWARD INTO THE
AREA...BRINGING WIDESPREAD SHOWERS TO THE FORECAST AREA. WITH THIS
IN MIND 100 POPS ARE FORECAST INTO THE EVENING WITH STRONG CAA
PROVIDING FORCING ALONG THE FRONT. SHOWERS WILL PUSH FROM EASTERN
OHIO INTO WESTERN PA AND NORTHERN WV INTO THE EARLY AFTERNOON AND
INTO WESTERN MD BY LATE AFTERNOON. A QUARTER TO A HALF OF AN INCH
OF PRECIPITATION IS FORECAST TODAY WITH THE PASSAGE OF THE FRONT
AND ITS ASSOCIATED BROAD AREA OF SHOWERS. STRONG WAA ADVECTION
AHEAD OF THE FRONT WILL ALLOW FOR TEMPS TO WARM INTO THE UPPER 60S
TO LOWER 70S AHEAD OF THE FRONT WITH TEMPS TODAY CLOSEST TO A
LAMP/HRRR BLEND.
DIURNAL TIMING OF THE APPROACH AND PASSAGE OF THE FRONT WILL BE
FAVORABLE FOR WINDS GUSTS OF UP TO 35 TO 40 MPH ACROSS MUCH OF THE
AREA. THE RAP INDICATES A 65KT 850MB JET MAX SHIFTING FROM
NORTHERN OHIO INTO LAKE ERIE THROUGH THE EARLY AFTERNOON. WITH
LOCATIONS NORTHWEST OF PITTSBURGH ON THE PERIPHERY OF THE
STRONGEST WINDS WITH THIS FEATURE AND THE FRONT BRINGING WINDS TO
THE SURFACE...A WIND ADVISORY HAS BEEN ISSUED FOR A TIER OF
COUNTIES NORTHWEST OF PITTSBURGH WITH BRIEF GUSTS UP TO 50 MPH
POSSIBLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
COLD FRONT WILL MOVE EAST OF THE RIDGES LATE THIS EVENING. SHOWERS
WILL END QUICKLY...GENERALLY AROUND 01Z IN OHIO AND AROUND 04Z
ACROSS THE REST OF THE REGION. PRECIPITATION WILL BE HELD UP A BIT
LONGER IN THE RIDGES. WIND GUSTS WILL WANE DURING THE EVENING
HOURS.
MUCH COLDER AIR WILL RUSH IN BEHIND THE FRONT. THERE LIKELY WILL
BE A BRIEF PERIOD OF EITHER A MIX OF RAIN AND SNOW SHOWERS OR ALL
SNOW SHOWERS ALONG THE BACK EDGE OF THE PRECIPITATION SHIELD.
A MUCH DRIER AIR MASS WILL MOVE IN WITH THE COLDER TEMPS...SO ANY
MIX/SNOW SHOWERS WILL NOT LAST LONG. THE ATMOSPHERE IS NOT SETTING
UP WELL FOR MUCH IF ANY LAKE ENHANCED/ EFFECT SNOW. WINDS NEVER
LINE UP...WITH A GOOD DEAL OF DIRECTIONAL SHEAR BETWEEN THE SFC
AND 700MB. ADDITIONALLY...THE VERY DRY AIR MASS WILL LOWER
INVERSIONS. THERE LIKELY WILL BE SOME UP-SLOPE SNOW SHOWERS OVER
THE HIGHEST RIDGES LATE TONIGHT...BUT THESE WILL BE LIGHT AND
SHORT LIVED AS THE COLDEST AIR NEVER MAKES IT THAT FAR SOUTH.
COLDER DAY ON TUESDAY...WITH SOME LIKE EFFECT SNOW SHOWERS
POSSIBLE ACROSS THE FAR NORTH. CLOUD COVER TUESDAY WILL BE
TRICKY...AS ANOTHER SHOT OF COLD AIR MOVES IN DURING THE
AFTERNOON. FORECAST SOUNDINGS ARE SHOWING A PRETTY DRY ATMOSPHERE
ACROSS MUCH OF THE REGION UNTIL VERY LATE IN THE DAY.
SFC HIGH WILL MOVE THROUGH ON WEDNESDAY...AS THE COLD AIR IS
PUSHED NORTHWARD.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL REMAIN NEARLY STATIONARY OVER THE NEW ENGLAND
STATES THROUGH THE WEEKEND...PROVIDING DRY WEATHER AND SLOWLY
MODERATING TEMPERATURES INTO SUNDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
A STRONG COLD FRONTAL PASSAGE CAN BE EXPECTED AT KZZV BY 19Z AND
SHOULD PUSH EAST OF KPBZ BY 23Z. AHEAD OF THE FRONT SOME SOUTHERLY
WIND GUSTS TO 30 KNOTS ARE LIKELY. SHOWERS CAN BE EXPECTED AHEAD OF
AND BEHIND THE FRONT WITH VFR CONDITIONS BECOME MVFR BEHIND THE
FRONTAL ZONE WITH THE SHOWERS. WINDS BEHIND THE FRONT WILL SHIFT
TO THE WEST WITH 25 TO 30 KNOT GUSTS INTO THE EVENING HOURS.
AS THE FRONT PUSHES WELL EAST OF THE DISTRICT DURING THE EARLY
MORNING RAIN SHOWERS WILL GIVE WAY TO SOME SNOW FLURRIES BEFORE
ENDING. WINDS WILL DIMINISH TOWARD DAYBREAK TUESDAY.
.OUTLOOK.../TUESDAY THOUGH FRIDAY/...
MVFR MAY STILL BE POSSIBLE FOR KFKL AND KDUJ TUESDAY DUE TO COLD
POOL LAKE-ENHANCED INSTABILITY CLOUDS AND SHOWERS. OTHERWISE VFR
WILL BE PREVALENT ACROSS THE UPPER OHO VALLEY INTO FRIDAY DUE TO
HIGH PRESSURE SUBSIDENCE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR OHZ039>041-048.
PA...WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR PAZ007-008-013.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1057 AM EST MON NOV 12 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE AREA THIS AFTERNOON INTO THE
EVENING...BRINGING GUSTY WINDS AND SHOWERS. A SHARP TEMPERATURE
DROP CAN BE EXPECTED IN THE WAKE OF THE FRONT TONIGHT INTO TUESDAY.
HIGH PRESSURE WILL THEN PROVIDE DRY AND CHILLY CONDITIONS THE
REST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A FORECAST UPDATE HAS BEEN ISSUED THIS MORNING TO INCREASE WINDS
NORTHWEST OF PITTSBURGH AND ACCOUNT FOR THE LATEST TRENDS AHEAD OF
A COLD FRONT.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH ACROSS
THE UPPER MIDWEST WITH THE UPPER OHIO VALLEY IN A SOUTHWESTERLY
FLOW AHEAD OF THIS FEATURE. AT THE SURFACE...A STRONG COLD FRONT
EXTENDS FROM LAKE ERIE SOUTH-SOUTHWESTWARD TO COLUMBUS AND INTO
SOUTH-CENTRAL OHIO. THE FRONT IS WELL-DEFINED BY A NARROW FRONTAL
BAND ON RADAR. HOWEVER...A BROAD AREA OF SHOWERS EXTENDS BOTH AHEAD
AND BEHIND THE FRONT. IN ADDITION...WITH THE FRONTAL PASSAGE...WINDS
ARE SHIFTING FROM SOUTHERLY TO WESTERLY IN OHIO AND HAVE BEEN
GUSTING AT AROUND 40 MPH.
BEHIND THE FRONT...STRONG COLD AIR ADVECTION IS ALSO QUITE
EVIDENT...WITH TEMPS ALREADY DROPPING INTO THE MID 30S UPSTREAM IN
INDIANA. AHEAD OF THE FRONT...THE UPPER OHIO VALLEY IS IN ENHANCED
WARM AIR ADVECTION,..WITH TEMPS WARMING TO NEAR 70 SOUTH OF
PITTSBURGH.
TODAY...THE COLD FRONT WILL CONTINUE EASTWARD INTO THE
AREA...BRINGING WIDESPREAD SHOWERS TO THE FORECAST AREA. WITH THIS
IN MIND 100 POPS ARE FORECAST INTO THE EVENING WITH STRONG CAA
PROVIDING FORCING ALONG THE FRONT. SHOWERS WILL PUSH FROM EASTERN
OHIO INTO WESTERN PA AND NORTHERN WV INTO THE EARLY AFTERNOON AND
INTO WESTERN MD BY LATE AFTERNOON. A QUARTER TO A HALF OF AN INCH
OF PRECIPITATION IS FORECAST TODAY WITH THE PASSAGE OF THE FRONT
AND ITS ASSOCIATED BROAD AREA OF SHOWERS. STRONG WAA ADVECTION
AHEAD OF THE FRONT WILL ALLOW FOR TEMPS TO WARM INTO THE UPPER 60S
TO LOWER 70S AHEAD OF THE FRONT WITH TEMPS TODAY CLOSEST TO A
LAMP/HRRR BLEND.
DIURNAL TIMING OF THE APPROACH AND PASSAGE OF THE FRONT WILL BE
FAVORABLE FOR WINDS GUSTS OF UP TO 35 TO 40 MPH ACROSS MUCH OF THE
AREA. THE RAP INDICATES A 65KT 850MB JET MAX SHIFTING FROM
NORTHERN OHIO INTO LAKE ERIE THROUGH THE EARLY AFTERNOON. WITH
LOCATIONS NORTHWEST OF PITTSBURGH ON THE PERIPHERY OF THE
STRONGEST WINDS WITH THIS FEATURE AND THE FRONT BRINGING WINDS TO
THE SURFACE...A WIND ADVISORY HAS BEEN ISSUED FOR A TIER OF
COUNTIES NORTHWEST OF PITTSBURGH WITH BRIEF GUSTS UP TO 50 MPH
POSSIBLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
COLD FRONT WILL MOVE EAST OF THE RIDGES LATE THIS EVENING. SHOWERS
WILL END QUICKLY...GENERALLY AROUND 01Z IN OHIO AND AROUND 04Z
ACROSS THE REST OF THE REGION. PRECIPITATION WILL BE HELD UP A BIT
LONGER IN THE RIDGES. WIND GUSTS WILL WANE DURING THE EVENING
HOURS.
MUCH COLDER AIR WILL RUSH IN BEHIND THE FRONT. THERE LIKELY WILL
BE A BRIEF PERIOD OF EITHER A MIX OF RAIN AND SNOW SHOWERS OR ALL
SNOW SHOWERS ALONG THE BACK EDGE OF THE PRECIPITATION SHIELD.
A MUCH DRIER AIR MASS WILL MOVE IN WITH THE COLDER TEMPS...SO ANY
MIX/SNOW SHOWERS WILL NOT LAST LONG. THE ATMOSPHERE IS NOT SETTING
UP WELL FOR MUCH IF ANY LAKE ENHANCED/ EFFECT SNOW. WINDS NEVER
LINE UP...WITH A GOOD DEAL OF DIRECTIONAL SHEAR BETWEEN THE SFC
AND 700MB. ADDITIONALLY...THE VERY DRY AIR MASS WILL LOWER
INVERSIONS. THERE LIKELY WILL BE SOME UP-SLOPE SNOW SHOWERS OVER
THE HIGHEST RIDGES LATE TONIGHT...BUT THESE WILL BE LIGHT AND
SHORT LIVED AS THE COLDEST AIR NEVER MAKES IT THAT FAR SOUTH.
COLDER DAY ON TUESDAY...WITH SOME LIKE EFFECT SNOW SHOWERS
POSSIBLE ACROSS THE FAR NORTH. CLOUD COVER TUESDAY WILL BE
TRICKY...AS ANOTHER SHOT OF COLD AIR MOVES IN DURING THE
AFTERNOON. FORECAST SOUNDINGS ARE SHOWING A PRETTY DRY ATMOSPHERE
ACROSS MUCH OF THE REGION UNTIL VERY LATE IN THE DAY.
SFC HIGH WILL MOVE THROUGH ON WEDNESDAY...AS THE COLD AIR IS
PUSHED NORTHWARD.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL REMAIN NEARLY STATIONARY OVER THE NEW ENGLAND
STATES THROUGH THE WEEKEND...PROVIDING DRY WEATHER AND SLOWLY
MODERATING TEMPERATURES INTO SUNDAY.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
MAIN CONCERN ACROSS THE UPPER OHIO VALLEY THROUGH 15Z WILL BE LOW
LEVEL WIND SHEAR...AS INDICATED BY RECENT KPBZ DOPPLER RADAR AND
NAM MODEL PROFILES...AS STRONG TEMPERATURE INVERSION AT 1 TO 2 KFT
AGL WILL INITIALLY PREVENT SOUTHWEST WINDS OF 40 TO 50 KTS TO MIX
DOWN TO SURFACE.
CONCERN 15Z TO 22Z WILL BE ONCE VERTICAL MIXING DOES OCCUR THAT SURFACE
WIND GUSTS CAN REACH 30 TO 35 KTS. THE SOUTHWEST DIRECTION OF THE
WINDS CAN ALSO CREATE CROSSWIND ISSUES FOR RUNWAYS OF A MORE EAST-
WEST ORIENTATION.
BLEND OF RECENT WRF-NMM AND SREF MODEL OUTPUT NEXT SHOW A STRONG
COLD FRONTAL PASSAGE MONDAY AFTERNOON INTO EVENING...WHICH WILL
PROMOTE A BAND OF MVFR RAIN SHOWERS AND A SHARP WIND SHIFT INTO A
WESTERLY DIRECTION.
THERE CAN BE A SHORT PERIOD OF IFR CONDITIONS DUE TO RAIN-
SATURATION OF THE THE SHARPLY COOLING SURFACE LAYER. SOME
SNOWFLAKES MAY ALSO OCCUR. THEN EXPECT MAINLY MVFR CONDITIONS LATE
MONDAY NIGHT.
.OUTLOOK.../TUESDAY THOUGH FRIDAY/...
MVFR MAY STILL BE POSSIBLE FOR KFKL AND KDUJ TUESDAY DUE TO COLD
POOL LAKE-ENHANCED INSTABILITY CLOUDS AND SHOWERS. OTHERWISE VFR
WILL BE PREVALENT ACROSS THE UPPER OHO VALLEY INTO FRIDAY DUE TO
HIGH PRESSURE SUBSIDENCE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR OHZ039>041-048.
PA...WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR PAZ007-008-013.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
406 PM EST MON NOV 12 2012
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 405 PM EST MON NOV 12 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A HIGH AMPLITUDE BUT
WEAKENING TROF EXTENDING FROM NRN ONTARIO THRU THE MISSISSIPPI
VALLEY. UNDERNEATH TROF EARLIER TODAY...12Z SOUNDINGS AT KINL/KMPX
SHOWED A DEEP MOISTURE PROFILE WITH 850MB TEMPS AROUND -15C WHICH
WILL ALLOW FOR A NICE INTERSECTION OF LAKE CONVECTION THRU THE DGZ.
SO...CONDITIONS ARE FAVORABLE FOR MDT/HVY LAKE EFFECT/LAKE ENHANCED
SNOW AS MID LEVEL TROF CONTINUES TO MOVE ACROSS THE UPPER GREAT
LAKES LATE THIS AFTN/EVENING. AS EXPECTED...A DOMINANT LES BAND
DEVELOPED OVER WRN LAKE SUPERIOR EARLIER TODAY BTWN THE MN NORTH
SHORE AND WISCONSIN`S BAYFIELD PENINSULA. WITH MID LEVEL TROF
PASSING...WINDS OVER WRN LAKE SUPERIOR ARE NOW VEERING MORE WRLY...
SO THIS DOMINANT LES BAND IS ADJUSTING TO THE CHANGING WIND...BUT IT
IS ALSO BECOMING LESS ORGANIZED...WHICH MAY BE PARTLY DUE TO
NEGATIVE DIURNAL AFFECTS. KMQT/KDLH AND ENVIRONMENT CANADA RADAR
LOCATED JUST N OF THUNDER BAY ALL INDICATE AREAS OF HEAVY LES NOW
NEARING THE WRN SHORE OF THE KEWEENAW. KDLH RADAR IS STILL SHOWING
RETURNS AS HIGH AS AROUND 12KFT...SO LAKE EFFECT CONVECTION REMAINS
DEEP WITH POCKETS OF VERY HVY SNOW. AHEAD OF THE HEAVIER SNOW...SHSN
HAVE BEEN AFFECTING PORTIONS OF THE KEWEENAW TODAY. HOWEVER...ONLY
WEBCAM THAT HAS CONSISTENTLY SHOWN SHARPLY REDUCED VIS AT TIMES IS
LOCATED ALONG THE SHORE WEST OF EAGLE RIVER.
FCST THINKING HASN`T CHANGED MUCH WITH REGARD TO LES AND HEADLINES
TONIGHT. DEEP MOISTURE AND FAVORABLE TEMP PROFILE ARGUES FOR MDT TO
HVY SNOW AT TIMES AS MID LEVEL TROF PASSES TONIGHT. BULK OF SNOW
ACCUMULATIONS ON THE KEWEENAW PENINSULA WILL OCCUR OVER THE NEXT
SEVERAL HRS AS WIND SHIFT/CONVERGENCE ZONE OVER THE WRN LAKE DROP S
ACROSS THE PENINSULA. MAY SEE SNOWFALL RATES BRIEFLY AS HIGH AS
2-4IN/HR. AFTER THE CONVERGENCE ZONE PASSES...WIND PARALLEL BANDS
WITH MUCH MORE VARIABLE SNOW INTENSITY WILL SET UP FOR THE REMAINDER
OF THE EVENING. LES WILL THEN QUICKLY DIMINISH OVERNIGHT AS SHARP
HEIGHT RISES OCCUR IN THE WAKE OF MID LEVEL TROF (180-200M HEIGHT
RISES AT 500MB BTWN 00Z AND 12Z)...INVERSION QUICKLY DROPS TO 4-5KFT
AND CONVECTIVE LAYER BEGINS TO FALL BLO THE DGZ. GIVEN THE SHORT
RESIDENCE TIME OF THE CONVERGENCE ZONE OVER THE KEWEENAW...AND
RATHER QUICK DIMINISHING TREND THRU THE NIGHT...HAVE LOWERED SNOW
AMOUNTS BY AN INCH OR TWO. MAX AMOUNTS WILL PROBABLY BE IN THE 4-5
INCH RANGE OVER THE HIGH TERRAIN.
FARTHER S...CONVERGENCE ZONE WILL SINK S AND AFFECT ONTONAGON/SRN
HOUGHTON COUNTIES THIS EVENING. ALTHOUGH PREVIOUSLY DISCUSSED
NEGATIVE FACTORS TAKE HOLD DURING THE NIGHT TO DIMINISH LES
INTENSITY...LOW-LEVEL WINDS WILL MAINTAIN A CONVERGENT LOOK AS WSW
LAND BREEZE ENHANCED WINDS OFF NW WI CONVERGE WITH WNW FLOW OVER
LAKE SUPERIOR. THIS SHOULD HELP TO AT LEAST MAINTAIN MORE PERSISTENT
THOUGH WEAKENING LES ACROSS ONTONAGON/SRN HOUGHTON COUNTIES AND
PROBABLY A SMALL PART OF GOGEBIC COUNTY N OF M-28 THRU THE NIGHT.
WILL RETAIN ADVY FOR ONTONAGON/SRN HOUGHTON COUNTIES TONIGHT.
TO THE E...WIND SHIFT/CONVERGENT BAND WILL EVENTUALLY MOVE ONSHORE
OVER THE NE FCST AREA TONIGHT. HOWEVER...BY THE TIME IT DOES...DEEP
MOISTURE WILL BE EXITING WITH SHARP HEIGHT RISES OCCURRING. SO...
WHILE THERE WILL LIKELY BE A BRIEF PERIOD OF MDT/HVY SNOW ON WIND
SHIFT...LES THAT ORGANIZES BEHIND TROF WILL NOT BE SUBSTANTIAL. WILL
PAINT 1-3 INCH ACCUMULATIONS ACROSS ALGER COUNTY E OF MUNISING AND
NRN LUCE COUNTY TONIGHT.
LINGERING LES WILL QUICKLY WIND DOWN/END FROM W TO E TUE. MIGHT SEE
AN ADDITIONAL INCH OF SNOW OVER ERN ALGER/NRN LUCE COUNTY IN THE
MORNING. OTHERWISE...LOOK FOR DECREASING CLOUDS FROM SW TO NE AS
WINDS BACK TO THE SW.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 405 PM EST MON NOV 12 2012
UPPER TROUGH THAT HAS LED TO THE UNSETTLED WEATHER THIS WEEKEND AND
TODAY WILL BE SHIFTING EAST OF THE UPPER GREAT LAKES ON TUESDAY
NIGHT. THIS WILL LEAD TO THE START OF SPLIT FLOW ACROSS MUCH OF THE
COUNTRY...WHICH WILL REALLY BECOME ESTABLISHED ON BY THE WEEKEND
BEHIND A WEAKER TROUGH MOVING THROUGH THE NORTHERN STREAM WEDNESDAY
INTO FRIDAY. THIS WILL LEAD TO A FAIRLY QUIET PATTERN ACROSS THE
UPPER GREAT LAKES FOR THE LONG TERM PERIOD.
HIGH PRESSURE RIDGE WILL BE OVER THE AREA AT THE START OF THE LONG
TERM PERIOD FROM HIGH PRESSURE CENTERED OVER THE LOWER GREAT LAKES
AND OHIO RIVER VALLEY. MOSTLY CLEAR SKIES TO START THE EVENING WILL
QUICKLY GIVE WAY TO INCREASING CLOUDS OVER THE WEST/CENTRAL...WHILE
ANY LINGERING LAKE EFFECT SHOWERS SHOULD BE PUSHING NE OVER EASTERN
LAKE SUPERIOR. THESE CLOUDS ARE IN ADVANCE OF A WEAK SHORTWAVE AND
WARM AIR ADVECTION THAT WILL MOVE ACROSS THE WESTERN CWA WEDNESDAY.
MODELS ARE CONSISTENT ON MOST OF THE MOISTURE STAYING ABOVE
H800...WITH BROAD AND WEAK LIFT ASSOCIATED WITH IT. THERE IS SOME
DRY AIR BELOW H800...BUT NOTHING TOO SUBSTANTIAL...SO THINK THAT
ANY PRECIPITATION THAT DOES FALL WILL MAKE IT TO THE SURFACE. WITH
THE BEST FORCING OVER WESTERN LAKE SUPERIOR...EXPECT THAT AREA TO
HAVE THE BEST CHANCE OF SHOWERS...SO HAVE SPREAD THE SLIGHT CHANCES
FARTHER SOUTH TO COVER MUCH OF WESTERN LAKE SUPERIOR ON WEDNESDAY.
OTHERWISE...THE MID CLOUDS WILL COVER THE REST OF THE CWA WITH ONLY
AN ISOLATED FLURRY OVER WESTERN UPPER MICHIGAN.
ONE OTHER ITEM OF NOTE FOR LATE TUESDAY NIGHT AND INTO WEDNESDAY
IS THE POTENTIAL FOR LAKE EFFECT PRECIPITATION OFF LAKE MICHIGAN.
DELTA T VALUES AROUND 15 WOULD SUPPORT LAKE ENHANCED PRECIPITATION
UNDER THE SLOWLY BACKING WINDS FROM SW TO SOUTHERLY ON WEDNESDAY.
MAIN LIMITING FACTOR APPEARS TO BE INVERSION HEIGHTS AROUND
4-5KFT. THERE ARE SOME HINTS IN THE MODELS THAT THIS INVERSION COULD
WEAKEN AS THE DEEPER MOISTURE ARRIVES AND LEAD TO AN INCREASE IN
INTENSITY. THIS LOOKS TO BE FAIRLY SHORT LIVED...AS DRIER
AIR BETWEEN H875-700 AND WAA MOVES BACK IN DURING THE AFTERNOON AND
DIMINISHES THE CHANCES AGAIN. WILL CONTINUE TO MENTION THE SLIGHT
CHANCES FOR THIS POTENTIAL...BUT SEEMS TO BE FAIRLY LIMITED.
THE SHORTWAVE MOVES AWAY FROM THE AREA WHILE A LOW PRESSURE SYSTEM
MOVES INTO HUDSON BAY. THIS SHOULD LEAD TO INCREASING SOUTHERLY
FLOW AHEAD OF A WEAK COLD FRONT MOVING INTO WESTERN ONTARIO. EXPECT
MID CLOUDS TO INCREASE AHEAD OF THIS FRONT ON WEDNESDAY
NIGHT...ESPECIALLY OVER THE NORTH HALF OF THE CWA. BOTH NAM/SREF
INDICATING INCREASED PROBABILITIES OF FOG OVER THE WEST...BUT THE
NAM HAS THINNER MID CLOUDS...WHICH WOULD LEAD BETTER RADIATIONAL
COOLING AND FOG POTENTIAL. WITH THE DIFFERENCES DIFFERENCES
IN THE MID CLOUDS...WILL LEAVE FOG MENTION OUT OF THE FORECAST DUE
TO THE POTENTIAL FOR MID CLOUDS.
DECAYING FRONTAL BOUNDARY WILL BE MOVING ACROSS THE NORTHERN HALF OF
THE CWA ON THURSDAY. THIS WILL LARGELY BE MARKED BY A WIND SHIFT AND
CLOUDS WHILE THE PRECIPITATION WILL STAY TO THE NORTH OF LAKE
SUPERIOR AND CLOSER TO THE BETTER FORCING/MOISTURE.
BEHIND THIS FRONTAL BOUNDARY AND WEAK UPPER TROUGH...SPLIT FLOW
REALLY SETTLES OVER THE NORTHERN HALF OF THE CONUS. THE SOUTHERN
STREAM JET LOOKS TO REMAIN OVER THE SOUTHERN TIER OF STATES...WHILE
THE NORTHERN STREAM RIDGES OVER NORTHERN CANADA. THIS SHOULD LEAD TO
A VERY QUIET AND LIKELY ABOVE NORMAL TEMPERATURE PERIOD FOR UPPER
MICHIGAN INTO NEXT WEEK. AT THE SURFACE...HIGH PRESSURE WILL SETTLE
OVER THE GREAT LAKES REGION FOR THURSDAY NIGHT INTO SATURDAY BEFORE
MOVING EAST INTO QUEBEC FOR SUNDAY AND MONDAY. DRY AIR ASSOCIATED
WITH THIS HIGH SHOULD PRODUCE DECREASING CLOUDS ON THURSDAY NIGHT
AND FRIDAY AND THEN PARTLY CLOUDY TO MOSTLY CLEAR SKIES INTO NEXT
WEEK. BIGGEST QUESTION WILL BE THE TEMPERATURES...AS THEY WILL
DEPEND ON HOW DEEP THE MIXING WILL BE. BOTH GFS/ECMWF INDICATING
H850 TEMPS RISING TOWARDS 1-2C THIS WEEKEND...BUT BOTH ARE
STRUGGLING TO MIX THOSE TEMPS TO THE SURFACE. WILL GO WITH THE
MIDDLE GROUND SINCE IT IS SO FAR OUT...HIGHS IN THE MID-UPPER
40S...BUT IF WE CAN TAP INTO THE WARMER TEMPS ALOFT...COULD EASILY
SEE HIGHS IN THE 50S AT THE FIRST PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1259 PM EST MON NOV 12 2012
AFTER PASSAGE OF LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT
YESTERDAY...WINDS HAVE TURNED TO A PREDOMINATELY WSW DIRECTION
ACROSS UPPER MI. WITH ABUNDANT LLVL MOISTURE STILL IN PLACE...AND
STRONG GRADIENT WINDS...LAKE EFFECT SNOW SHOWERS HAVE DEVELOPED IN
FAVORED LOCATIONS /NAMELY KCMX/. THIS SET UP HAS ALSO PRODUCED LIGHT
SHSN ACROSS CENTRAL UPPER MI DIRECTLY IMPACTING KSAW. EXPECT SNOW
SHOWERS AT KSAW TO CONTINUE THROUGH THE DAY BASED ON LATEST RADAR
TRENDS...AND BEGIN TO CLEAR OUT OVERNIGHT AS DRIER AIRMASS MOVES IN
FROM THE SOUTH. KIWD AND KSAW WILL SCATTER OUT TO VFR THROUGH THE
MORNING HOURS. KCMX /ON THE OTHER HAND/ WILL SEE LAKE EFFECT SHSN
INTENSIFY THROUGHOUT THE DAY...WITH LIFR CONDITIONS POSSIBLE BY
EVENING. EXPOSED WINDS OFF LAKE SUPERIOR WILL PRODUCE BLSN AND LOW
VIS. MAY NEED TO MAKE UPDATES AS NEEDED FOR TIMING AND IMPACTS.
DRIER AIR WILL SLOWLY MOVE IN BY LATE TOMORROW MORNING...INCREASING
CONDITIONS TO MVFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EST MON NOV 12 2012
A TIGHT PRESSURE GRADIENT BETWEEN THE FRONT THAT MOVED THROUGH LAST
NIGHT AND ANOTHER SURFACE TROUGH MOVING THROUGH NORTHERN MN WILL
KEEP WINDS IN THE 20-30KT RANGE TONIGHT AS THEY SHIFT TO A MORE
NORTHWESTERLY DIRECTION. THERE COULD ALSO BE A FEW GALE FORCE GUSTS
TO 35 KNOTS TONIGHT...MAINLY OVER THE EASTERN HALF OF LAKE SUPERIOR.
A WEAK HIGH PRESSURE RIDGE WILL MOVE ACROSS LAKE SUPERIOR ON TUESDAY
NIGHT AND LEAD TO WINDS WEAKENING BELOW 25KTS. A LOW PRESSURE SYSTEM
MOVING INTO HUDSON BAY WILL BRING A TIGHTENING PRESSURE GRADIENT
OVER LAKE SUPERIOR...WHICH WILL INCREASE WINDS OUT OF THE SOUTHWEST
TO 20-30KTS OVER EASTERN LAKE SUPERIOR ON WEDNESDAY INTO WEDNESDAY
EVENING. HIGH PRESSURE WILL THEN SETUP OVER THE GREAT LAKES REGION
ON THURSDAY NIGHT AND SLOWLY DRIFT TO THE NORTHEAST THROUGH THE
FIRST PART OF NEXT WEEK. THIS WILL LEAD TO WINDS STAYING BELOW
20KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ084.
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ001>003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...JMW
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
100 PM EST MON NOV 12 2012
.UPDATE...
ISSUED AT 1011 AM EST MON NOV 12 2012
MAIN CONCERN THIS AFTN IS ADVY HEADLINES OVER THE NW FCST AREA. AS
EXPECTED...WSW FLOW HAS LED TO THE DEVELOPMENT OF A DOMINANT LES
BAND OVER WRN LAKE SUPERIOR. BAND SHOWS UP VERY NICELY ON KDLH RADAR
IMAGERY BTWN THE MN NORTH SHORE AND WISCONSIN`S BAYFIELD PENINSULA.
HIGHEST ELEVATION RADAR RETURNS IN THE BAND ARE UP AROUND 10KFT.
ATTM...WINDS ARE BACKED A LITTLE MORE TO THE SW THAN EXPECTED OVER
SRN PORTIONS OF WRN LAKE SUPERIOR. AS A RESULT...THIS DOMINANT LES
BAND IS STREAMING ENE DOWN THE ROUGHLY MIDLAKE PORTION BTWN THE
KEWEENAW AND ISLE ROYALE. 12Z SOUNDINGS AT KINL/KMPX SHOWED A DEEP
MOISTURE PROFILE WITH 850MB TEMPS AROUND -15C WHICH WILL ALLOW FOR A
NICE INTERSECTION OF LAKE CONVECTION THRU THE DGZ. SO...CONDITIONS
ARE VERY FAVORABLE FOR LAKE EFFECT/LAKE ENHANCED SNOW AS UPSTREAM
MID LEVEL TROF OVER ERN MN ARRIVES. ONLY CONCERN FOR THE KEWEENAW
PENINSULA IS THAT AS WINDS SHIFT MORE W AS TROF PASSES...THE
DOMINANT LES BAND WILL HAVE A SHORT RESIDENCE TIME ACROSS THE
KEWEENAW...WHICH MAY RESULT IN LWR SNOW TOTALS THAN CURRENTLY FCST.
HOWEVER...THE VERY FAVORABLE LES PARAMETERS WILL STILL RESULT IN A
PERIOD OF POTENTIALLY VERY HVY SNOW...PERHAPS 2-4IN/HR RATES...AS
THE DOMINANT BAND PASSES ACROSS KEWEENAW. AFTER THE BAND PASSES
DURING THE MID TO LATE AFTN PERIOD...WIND PARALLEL BANDS WITH MORE
VARIABLE SNOW INTENSITY WILL SET UP FOR THE EVENING. FOR NOW...WILL
LARGELY MAINTAIN PREVIOUS FCST SNOW TOTALS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EST MON NOV 12 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE UPR
RDG OVER THE PLAINS BTWN RDGS OVER THE E AND THE W. COLD FNT
ATTENDANT TO SFC LO MOVING THRU ONTARIO TOWARD HUDSON BAY AND UNDER
SSW FLOW ALF HAS PUSHED TO JUST E OF A P53-ESC LINE AS OF 06Z. BULK
OF PCPN IN THE FORM OF RA ALONG THIS BNDRY IS OVER THE E HALF OF THE
CWA FORCED BY VIGOROUS UPR DVGC IN RRQ OF 140KT H3 JET MAX OVER NW
ONTARIO AND SHARP LO-MID LVL FGEN LIFTING OF VERY WARM/MOIST AIRMASS
/00Z PWAT NEAR 1 INCH UP TO 250 PCT OF NORMAL/ JUST E OF THE FNT.
ARRIVAL OF COLDER AIR HAS CAUSED A MIX WITH SN OVER THE W HALF...BUT
DRYING ALF WITH 00Z INL/MPX RAOBS SHOWING VERY DRY AIR AOA H75-8 AND
SLGT ACYC SFC FLOW BEHIND THE FNT HAS KEPT THE WINTRY PCPN ON THE
LGT SIDE. FARTHER TO THE W UNDER THE UPR TROF AXIS...A VERY
PRONOUNCED H85-7 THERMAL TROF IS PRESENT WITHIN SHARP CYC FLOW. 00Z
H85/7 TEMPS ARE AS LO AS -17C/-20C IN THE NRN PLAINS...AND 00Z
BISMARCK RAOB SHOWS DEEP MSTR SFC THRU H6.
FCST CONCERNS IN THE SHORT TERM ARE RELATED TO TIMING THE EXIT OF
LARGER SCALE PCPN OVER THE E HALF AND THE DETAILS OF THE TRANSITION
TO AN LES REGIME TDAY THRU TNGT AS COLDER/MOISTER AIR IN THE NRN
PLAINS SWINGS THRU THE UPR LKS UNDER PASSING UPR TROF.
TDAY...WITH THE EXPECTED ARRIVAL OF DRIER AIR ALF...EXPECT ONGOING
SYNOPTIC SCALE PCPN OVER THE FAR E AT ERY TO END ARND 12Z. ARRIVAL
OF WEAK SFC HI PRES RDG UNDER THE DRY AXIS AT H7 SHOULD BRING A
MAINLY DRY PERIOD TO MOST OF THE CWA THIS AFTN...BUT THE ARRIVAL OF
THE DEEPER MSTR/COLDER H85 AIR OVER THE W LATE THIS MRNG WL BRING
INCRSG LES CHCS TO THAT AREA. WITH THE LLVL FLOW BACKING MORE WSW
WITH ARPCH OF SFC TROF...EXPECT A DOMINANT BAND TO FORM OVER THE
LENGTH OF WRN LK SUP WITH H85 TEMPS SINKING TO -13C TO -15C BY 12Z
AND LINGERING THRU THE DAY. IN FACT...A QUICK LOOK AT THE DLH RADAR
AT 0630Z SHOWS WHAT APPEARS TO BE THE START OF THIS LES BAND JUST N
OF THE APOSTLE ISLANDS. INITIALLY...THE BULK OF THE LOCAL HI RES
MODELS INDICATE THE BAND WL REMAIN JUST OFF THE W SHORE OF THE
KEWEENAW WITH SLGT LAND BREEZE COMPONENT/MORE SW FLOW OVER LAND
ASSOCIATED WITH WARMING OVER THE OPEN WATERS MAINTAINING THE SHARPER
LLVL CNVGC THERE AS THE LARGER SCALE FLOW BACKS A BIT AHEAD OF
APRCHG LO PRES TROF. BUT AS THE H925 WINDS BEGIN TO VEER OVER WRN LK
SUP WITH ARRIVAL OF THE TROF THIS AFTN...EXPECT THE HEAVIER BAND TO
COME ASHORE OVER THE W FM THE PORCUPINE MTNS TO THE KEWEENAW.
FAVORABLE OMEGA PROFILE SOLIDLY IN THE DGZ IN CONCERT WITH DEEP MSTR
TO AT LEAST H7/SHARP LLVL CNVGC WL ENHANCE SN RATES WITHIN THIS BAND
AND JUSTIFIES CURRENT ADVY...ESPECIALLY FOR THE W SIDE OF THE
KEWEENAW WHERE THE BAND RESIDENCE TIME MIGHT BE A BIT LONGER.
TNGT...WITH PASSAGE OF LO PRES TROF/VEERING H925 WINDS TO WNW...
EXPECT THE LES OVER THE W TO EVOLVE INTO A MULTIPLE BAND EVENT.
GRADUAL WARMING WITH THE PASSAGE OF THE H85 THERMAL TROF AS WELL AS
FCST SHARPENING/LOWERING INVRN THAT NEARLY DRIES OUT THE DGZ BY 09Z
AS WELL AS DVLPG MORE ACYC FLOW OVER THE W WL CAUSE THE INTENSITY OF
THE LES TO DIMINISH THERE DURING THE EARLY MRNG HRS ON TUE. BUT OVER
THE E...THE VEERING WIND WL ALLOW LES BANDS TO COME ASHORE AT LEAST
N OF M-28. OVER THE CENTRAL CWA...EXPECT NOTHING MORE THAN ISOLD-
SCT -SHSN...WITH JUST QUITE A BIT OF SC IN DOWNSLOPING FLOW OF
RELATIVELY UNMODIFIED COLDER AIRMASS.
AS FOR HEADLINES...THE EXPECTED TIMING OF THE START OF THE LES OVER
THE W INDICATES THE START OF THE GOING ADVY FOR THE THE KEWEENAW AT
12Z IS A BIT TOO EARLY...SO OPTED TO PUSH BACK THE BEGINNING OF THE
ADVY UNTIL 17Z. ALSO DECIDED TO INCLUDE ONTONAGON COUNTY IN THE
HEADLINE AS THE TOWN OF ONTONAGON WL BE IMPACTED BY THE DOMINANT
BAND. SOME OF THE HIER RES MODELS ALSO INDICATE ENHANCED LAND BREEZE
CNVGC TNGT IN THAT COUNTY WITH MORE SW FLOW OF THE COLDER SFC AIR
NEAR THE WI BORDER AND WNW LK MODIFIED WIND JUST TO THE N. SINCE ANY
SHSN WL NOT BEGIN UNTIL LATER IN THE 2ND PERIOD FOR THE E...WL NOT
POST ANY HEADLINE FOR THAT AREA ATTM.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 457 AM EST MON NOV 12 2012
UPPER TROUGH OVER THE GREAT LAKES TO START THE PERIOD MOVES INTO
EASTERN CANADA AND DE-AMPLIFIES BY WEDNESDAY. WHAT IS LEFT IN ITS
WAKE IS A ZONAL SPLIT FLOW PATTERN ALOFT. NORTHERN AND SOUTHERN JET
STREAMS AND RESULTING STORM TRACKS STAY AWAY FROM THE GREAT LAKES
REGION. NO REAL SIGNIFICANT SYSTEMS ARE EXPECTED FOR THE REST OF THE
WEEK AND INTO NEXT WEEKEND.
HAVE LINGERING LK EFFECT SNOW ISSUES TO DEAL WITH INITIALLY ON
TUESDAY. SHORT WINDOW OF MORE FAVORABLE CONDITIONS FOR LES THROUGH
MID-LATE MORNING WITH INVERSION HEIGHT STAYING AROUND 5-6KFT AND
TEMPS AT TOP OF INVERSION AOB -10C. CONVERGENT LOW-LEVEL FLOW ALSO
SUPPORTS POTENTIAL FOR A COUPLE OF DOMINANT BANDS OF SNOW TO AFFECT
EASTERN CWA...MAINLY OVER EASTERN ALGER COUNTY INTO LUCE COUNTY
NORTH OF M-28. A FEW INCHES OF SNOW MAY OCCUR IN THOSE AREAS DURING
THE MORNING HOURS. LOW-LEVEL WARM AIR ADVECTION/LOWERING INVERSION
AND INCREASING ANTI-CYCLONIC LOW-LEVEL FLOW WILL CONSIDERABLY
DIMINISH THE LK EFFECT BY EARLY-MID AFTN. AFT 18Z...925MB WINDS
BACK SOUTH OF WEST...WHICH WILL KICK WHATEVER LES REMAINS OFFSHORE
AND ACROSS CANADIAN SHORELINE NORTH OF WHITEFISH BAY. HIGHER
RESOLUTION MODELS INCLUDING NAM...GEM-REGIONAL AND NCEP WRF-ARW
SUPPORT GENERAL THEME FOR THE EVOLUTION OF THE LK EFFECT. EVEN WITH
DECREASING CLOUDS ELSEWHERE THROUGHOUT THE DAY...LIMITED MIXING AND
COLD NEAR SFC AIR WILL LIMIT RISE TO MAX TEMPS. DESPITE SUNSHINE
BY AFTN...HIGHS WILL ONLY TOP OUT IN THE LOW-MID 30S.
GFS STILL SHOWING POTENTIAL FOR LGT PRECIP ON WEDNESDAY AS H85-H7
WARM AIR ADVECTION TAKES HOLD AS UPPER TROUGH DEPARTS INTO EASTERN
CANADA. GEM-NHEM AND SREF ALSO INDICATE SOME LIGHT QPF. FORECAST
SOUNDINGS INDICATE A LOT OF MOISTURE EXTENDING AS LOW AS H7 BUT LIFT
WITHIN THE MOISTURE IS WEAK AND IT REMAINS QUITE DRY BLO H7.
INCLUDED SLIGHT CHANCES IN THE EAST AS SOUTH FLOW OFF LK MICHIGAN
MAY PROVIDE ENOUGH ADDITIONAL MOISTURE TO LEAD TO LGT RAIN/SNOW
SHOWERS. SREF PROBABILITIES POINTED TO GREATEST CHANCE FOR
MEASURABLE OVER FAR EAST IN THE AFTN. WENT THAT WAY FOR FCST.
MID CLOUDS PERSIST THROUGH WEDNESDAY NIGHT AND INTO THURSDAY AS
PARADE OF WEAK SHORTWAVES MOVE TROUGH IN THE ZONAL FLOW. EVEN
SHALLOW MIXING ON THURSDAY WOULD SUPPORT MAX TEMPS INTO THE LOWER
40S. WEAK SFC TROUGH TRIES TO MAKE IT ACROSS UPR MICHIGAN LATER
THURSDAY...BUT ONCE IT DOES PUSH ACROSS LK SUPERIOR THURSDAY NIGHT
IT ONLY ENDS UP BEING A SUBTLE WIND SHIFT WITH NO PRECIPITATION.
SINCE H85 TEMPS DO LOWER DOWN TO -4C OVR LK SUPERIOR BY FRIDAY
MORNING INCREASED SKY COVER SOME OVER CONSENSUS WITH SUFFICIENT
OVER-WATER INSTABILITY FOR LK EFFECT CLOUDS. ANY CLOUDS WILL BREAK
UP BY FRIDAY AFTN AS ONCE AGAIN WARMER AIR MOVES BACK IN AS HIGH
PRESSURE RE-ASSERTS ITS INFLUENCE OVER MUCH OF THE EASTERN CONUS.
RIDGE AXIS STAYS TO EAST OF UPR LAKES THROUGH NEXT WEEKEND...SO
EXPECT SOUTH TO SOUTHWEST WINDS AND CONTINUED WARMER THAN NORMAL
TEMPS OVER UPR MICHIGAN. OVERALL A QUIET STRETCH OF WEATHER IN STORE
ONCE EARLY WEEK TROUGHING/WINTRY WEATHER DEPARTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1259 PM EST MON NOV 12 2012
AFTER PASSAGE OF LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT
YESTERDAY...WINDS HAVE TURNED TO A PREDOMINATELY WSW DIRECTION
ACROSS UPPER MI. WITH ABUNDANT LLVL MOISTURE STILL IN PLACE...AND
STRONG GRADIENT WINDS...LAKE EFFECT SNOW SHOWERS HAVE DEVELOPED IN
FAVORED LOCATIONS /NAMELY KCMX/. THIS SET UP HAS ALSO PRODUCED LIGHT
SHSN ACROSS CENTRAL UPPER MI DIRECTLY IMPACTING KSAW. EXPECT SNOW
SHOWERS AT KSAW TO CONTINUE THROUGH THE DAY BASED ON LATEST RADAR
TRENDS...AND BEGIN TO CLEAR OUT OVERNIGHT AS DRIER AIRMASS MOVES IN
FROM THE SOUTH. KIWD AND KSAW WILL SCATTER OUT TO VFR THROUGH THE
MORNING HOURS. KCMX /ON THE OTHER HAND/ WILL SEE LAKE EFFECT SHSN
INTENSIFY THROUGHOUT THE DAY...WITH LIFR CONDITIONS POSSIBLE BY
EVENING. EXPOSED WINDS OFF LAKE SUPERIOR WILL PRODUCE BLSN AND LOW
VIS. MAY NEED TO MAKE UPDATES AS NEEDED FOR TIMING AND IMPACTS.
DRIER AIR WILL SLOWLY MOVE IN BY LATE TOMORROW MORNING...INCREASING
CONDITIONS TO MVFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EST MON NOV 12 2012
EXPECT WEST WINDS UP TO 30 KTS TO CONTINUE INTO TONIGHT UNDER SHARP
PRES GRADIENT BETWEEN HI PRES IN THE PLAINS AND LO PRES MOVING INTO
HUDSON BAY AND AS VERY COLD AIRMASS SPILLS OVER THE RELATIVELY WARM
WATERS OF LAKE SUPERIOR TO ENHANCE MIXING OF STRONGER WINDS TO THE
SURFACE. THE BEST CHANCE FOR ANY GALE FORCE GUSTS UP TO 35 KTS WILL
BE THRU THIS AFTERNOON ALONG THE W SHORE OF UPR MI...WHERE LOCAL
TERRAIN INFLUENCES WILL TEND TO ENHANCE WIND SPEEDS...AND OVER THE E
HALF THIS AFTERNOON AND TONIGHT. THE WINDS WILL TEND TO DIMINISH
OVER WESTERN LAKE SUPERIOR TONIGHT WITH THE CLOSER APPROACH OF HI
PRES FROM THE PLAINS.
PRESSURE GRADIENT RELAXES FURTHER TUESDAY AND TUESDAY NIGHT ALLOWING
WINDS TO DIMINISH BLO 25 KTS. EXPECT SOUTH WINDS TO INCREASE TO
25-30 KTS ON WEDNESDAY AS LOW PRESSURE TROUGH PUSHES TOWARD ONTARIO
AND HIGH PRESSURE LIFTS FROM OHIO VALLEY INTO QUEBEC. STRONGEST WINDS
ON WEDNESDAY WILL BE OVER EASTERN SECTIONS OF LK SUPERIOR. WINDS
DIMINISH BLO 25 KTS THURSDAY INTO NEXT WEEKEND AS HIGH PRESSURE
BUILDS OVER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
TUESDAY FOR MIZ084.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
TUESDAY FOR MIZ002.
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...KC
LONG TERM...JLA
AVIATION...JMW
MARINE...KC/JLA
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1015 AM EST MON NOV 12 2012
.UPDATE...
ISSUED AT 1011 AM EST MON NOV 12 2012
MAIN CONCERN THIS AFTN IS ADVY HEADLINES OVER THE NW FCST AREA. AS
EXPECTED...WSW FLOW HAS LED TO THE DEVELOPMENT OF A DOMINANT LES
BAND OVER WRN LAKE SUPERIOR. BAND SHOWS UP VERY NICELY ON KDLH RADAR
IMAGERY BTWN THE MN NORTH SHORE AND WISCONSIN`S BAYFIELD PENINSULA.
HIGHEST ELEVATION RADAR RETURNS IN THE BAND ARE UP AROUND 10KFT.
ATTM...WINDS ARE BACKED A LITTLE MORE TO THE SW THAN EXPECTED OVER
SRN PORTIONS OF WRN LAKE SUPERIOR. AS A RESULT...THIS DOMINANT LES
BAND IS STREAMING ENE DOWN THE ROUGHLY MIDLAKE PORTION BTWN THE
KEWEENAW AND ISLE ROYALE. 12Z SOUNDINGS AT KINL/KMPX SHOWED A DEEP
MOISTURE PROFILE WITH 850MB TEMPS AROUND -15C WHICH WILL ALLOW FOR A
NICE INTERSECTION OF LAKE CONVECTION THRU THE DGZ. SO...CONDITIONS
ARE VERY FAVORABLE FOR LAKE EFFECT/LAKE ENHANCED SNOW AS UPSTREAM
MID LEVEL TROF OVER ERN MN ARRIVES. ONLY CONCERN FOR THE KEWEENAW
PENINSULA IS THAT AS WINDS SHIFT MORE W AS TROF PASSES...THE
DOMINANT LES BAND WILL HAVE A SHORT RESIDENCE TIME ACROSS THE
KEWEENAW...WHICH MAY RESULT IN LWR SNOW TOTALS THAN CURRENTLY FCST.
HOWEVER...THE VERY FAVORABLE LES PARAMETERS WILL STILL RESULT IN A
PERIOD OF POTENTIALLY VERY HVY SNOW...PERHAPS 2-4IN/HR RATES...AS
THE DOMINANT BAND PASSES ACROSS KEWEENAW. AFTER THE BAND PASSES
DURING THE MID TO LATE AFTN PERIOD...WIND PARALLEL BANDS WITH MORE
VARIABLE SNOW INTENSITY WILL SET UP FOR THE EVENING. FOR NOW...WILL
LARGELY MAINTAIN PREVIOUS FCST SNOW TOTALS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EST MON NOV 12 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE UPR
RDG OVER THE PLAINS BTWN RDGS OVER THE E AND THE W. COLD FNT
ATTENDANT TO SFC LO MOVING THRU ONTARIO TOWARD HUDSON BAY AND UNDER
SSW FLOW ALF HAS PUSHED TO JUST E OF A P53-ESC LINE AS OF 06Z. BULK
OF PCPN IN THE FORM OF RA ALONG THIS BNDRY IS OVER THE E HALF OF THE
CWA FORCED BY VIGOROUS UPR DVGC IN RRQ OF 140KT H3 JET MAX OVER NW
ONTARIO AND SHARP LO-MID LVL FGEN LIFTING OF VERY WARM/MOIST AIRMASS
/00Z PWAT NEAR 1 INCH UP TO 250 PCT OF NORMAL/ JUST E OF THE FNT.
ARRIVAL OF COLDER AIR HAS CAUSED A MIX WITH SN OVER THE W HALF...BUT
DRYING ALF WITH 00Z INL/MPX RAOBS SHOWING VERY DRY AIR AOA H75-8 AND
SLGT ACYC SFC FLOW BEHIND THE FNT HAS KEPT THE WINTRY PCPN ON THE
LGT SIDE. FARTHER TO THE W UNDER THE UPR TROF AXIS...A VERY
PRONOUNCED H85-7 THERMAL TROF IS PRESENT WITHIN SHARP CYC FLOW. 00Z
H85/7 TEMPS ARE AS LO AS -17C/-20C IN THE NRN PLAINS...AND 00Z
BISMARCK RAOB SHOWS DEEP MSTR SFC THRU H6.
FCST CONCERNS IN THE SHORT TERM ARE RELATED TO TIMING THE EXIT OF
LARGER SCALE PCPN OVER THE E HALF AND THE DETAILS OF THE TRANSITION
TO AN LES REGIME TDAY THRU TNGT AS COLDER/MOISTER AIR IN THE NRN
PLAINS SWINGS THRU THE UPR LKS UNDER PASSING UPR TROF.
TDAY...WITH THE EXPECTED ARRIVAL OF DRIER AIR ALF...EXPECT ONGOING
SYNOPTIC SCALE PCPN OVER THE FAR E AT ERY TO END ARND 12Z. ARRIVAL
OF WEAK SFC HI PRES RDG UNDER THE DRY AXIS AT H7 SHOULD BRING A
MAINLY DRY PERIOD TO MOST OF THE CWA THIS AFTN...BUT THE ARRIVAL OF
THE DEEPER MSTR/COLDER H85 AIR OVER THE W LATE THIS MRNG WL BRING
INCRSG LES CHCS TO THAT AREA. WITH THE LLVL FLOW BACKING MORE WSW
WITH ARPCH OF SFC TROF...EXPECT A DOMINANT BAND TO FORM OVER THE
LENGTH OF WRN LK SUP WITH H85 TEMPS SINKING TO -13C TO -15C BY 12Z
AND LINGERING THRU THE DAY. IN FACT...A QUICK LOOK AT THE DLH RADAR
AT 0630Z SHOWS WHAT APPEARS TO BE THE START OF THIS LES BAND JUST N
OF THE APOSTLE ISLANDS. INITIALLY...THE BULK OF THE LOCAL HI RES
MODELS INDICATE THE BAND WL REMAIN JUST OFF THE W SHORE OF THE
KEWEENAW WITH SLGT LAND BREEZE COMPONENT/MORE SW FLOW OVER LAND
ASSOCIATED WITH WARMING OVER THE OPEN WATERS MAINTAINING THE SHARPER
LLVL CNVGC THERE AS THE LARGER SCALE FLOW BACKS A BIT AHEAD OF
APRCHG LO PRES TROF. BUT AS THE H925 WINDS BEGIN TO VEER OVER WRN LK
SUP WITH ARRIVAL OF THE TROF THIS AFTN...EXPECT THE HEAVIER BAND TO
COME ASHORE OVER THE W FM THE PORCUPINE MTNS TO THE KEWEENAW.
FAVORABLE OMEGA PROFILE SOLIDLY IN THE DGZ IN CONCERT WITH DEEP MSTR
TO AT LEAST H7/SHARP LLVL CNVGC WL ENHANCE SN RATES WITHIN THIS BAND
AND JUSTIFIES CURRENT ADVY...ESPECIALLY FOR THE W SIDE OF THE
KEWEENAW WHERE THE BAND RESIDENCE TIME MIGHT BE A BIT LONGER.
TNGT...WITH PASSAGE OF LO PRES TROF/VEERING H925 WINDS TO WNW...
EXPECT THE LES OVER THE W TO EVOLVE INTO A MULTIPLE BAND EVENT.
GRADUAL WARMING WITH THE PASSAGE OF THE H85 THERMAL TROF AS WELL AS
FCST SHARPENING/LOWERING INVRN THAT NEARLY DRIES OUT THE DGZ BY 09Z
AS WELL AS DVLPG MORE ACYC FLOW OVER THE W WL CAUSE THE INTENSITY OF
THE LES TO DIMINISH THERE DURING THE EARLY MRNG HRS ON TUE. BUT OVER
THE E...THE VEERING WIND WL ALLOW LES BANDS TO COME ASHORE AT LEAST
N OF M-28. OVER THE CENTRAL CWA...EXPECT NOTHING MORE THAN ISOLD-
SCT -SHSN...WITH JUST QUITE A BIT OF SC IN DOWNSLOPING FLOW OF
RELATIVELY UNMODIFIED COLDER AIRMASS.
AS FOR HEADLINES...THE EXPECTED TIMING OF THE START OF THE LES OVER
THE W INDICATES THE START OF THE GOING ADVY FOR THE THE KEWEENAW AT
12Z IS A BIT TOO EARLY...SO OPTED TO PUSH BACK THE BEGINNING OF THE
ADVY UNTIL 17Z. ALSO DECIDED TO INCLUDE ONTONAGON COUNTY IN THE
HEADLINE AS THE TOWN OF ONTONAGON WL BE IMPACTED BY THE DOMINANT
BAND. SOME OF THE HIER RES MODELS ALSO INDICATE ENHANCED LAND BREEZE
CNVGC TNGT IN THAT COUNTY WITH MORE SW FLOW OF THE COLDER SFC AIR
NEAR THE WI BORDER AND WNW LK MODIFIED WIND JUST TO THE N. SINCE ANY
SHSN WL NOT BEGIN UNTIL LATER IN THE 2ND PERIOD FOR THE E...WL NOT
POST ANY HEADLINE FOR THAT AREA ATTM.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 457 AM EST MON NOV 12 2012
UPPER TROUGH OVER THE GREAT LAKES TO START THE PERIOD MOVES INTO
EASTERN CANADA AND DE-AMPLIFIES BY WEDNESDAY. WHAT IS LEFT IN ITS
WAKE IS A ZONAL SPLIT FLOW PATTERN ALOFT. NORTHERN AND SOUTHERN JET
STREAMS AND RESULTING STORM TRACKS STAY AWAY FROM THE GREAT LAKES
REGION. NO REAL SIGNIFICANT SYSTEMS ARE EXPECTED FOR THE REST OF THE
WEEK AND INTO NEXT WEEKEND.
HAVE LINGERING LK EFFECT SNOW ISSUES TO DEAL WITH INITIALLY ON
TUESDAY. SHORT WINDOW OF MORE FAVORABLE CONDITIONS FOR LES THROUGH
MID-LATE MORNING WITH INVERSION HEIGHT STAYING AROUND 5-6KFT AND
TEMPS AT TOP OF INVERSION AOB -10C. CONVERGENT LOW-LEVEL FLOW ALSO
SUPPORTS POTENTIAL FOR A COUPLE OF DOMINANT BANDS OF SNOW TO AFFECT
EASTERN CWA...MAINLY OVER EASTERN ALGER COUNTY INTO LUCE COUNTY
NORTH OF M-28. A FEW INCHES OF SNOW MAY OCCUR IN THOSE AREAS DURING
THE MORNING HOURS. LOW-LEVEL WARM AIR ADVECTION/LOWERING INVERSION
AND INCREASING ANTI-CYCLONIC LOW-LEVEL FLOW WILL CONSIDERABLY
DIMINISH THE LK EFFECT BY EARLY-MID AFTN. AFT 18Z...925MB WINDS
BACK SOUTH OF WEST...WHICH WILL KICK WHATEVER LES REMAINS OFFSHORE
AND ACROSS CANADIAN SHORELINE NORTH OF WHITEFISH BAY. HIGHER
RESOLUTION MODELS INCLUDING NAM...GEM-REGIONAL AND NCEP WRF-ARW
SUPPORT GENERAL THEME FOR THE EVOLUTION OF THE LK EFFECT. EVEN WITH
DECREASING CLOUDS ELSEWHERE THROUGHOUT THE DAY...LIMITED MIXING AND
COLD NEAR SFC AIR WILL LIMIT RISE TO MAX TEMPS. DESPITE SUNSHINE
BY AFTN...HIGHS WILL ONLY TOP OUT IN THE LOW-MID 30S.
GFS STILL SHOWING POTENTIAL FOR LGT PRECIP ON WEDNESDAY AS H85-H7
WARM AIR ADVECTION TAKES HOLD AS UPPER TROUGH DEPARTS INTO EASTERN
CANADA. GEM-NHEM AND SREF ALSO INDICATE SOME LIGHT QPF. FORECAST
SOUNDINGS INDICATE A LOT OF MOISTURE EXTENDING AS LOW AS H7 BUT LIFT
WITHIN THE MOISTURE IS WEAK AND IT REMAINS QUITE DRY BLO H7.
INCLUDED SLIGHT CHANCES IN THE EAST AS SOUTH FLOW OFF LK MICHIGAN
MAY PROVIDE ENOUGH ADDITIONAL MOISTURE TO LEAD TO LGT RAIN/SNOW
SHOWERS. SREF PROBABILITIES POINTED TO GREATEST CHANCE FOR
MEASURABLE OVER FAR EAST IN THE AFTN. WENT THAT WAY FOR FCST.
MID CLOUDS PERSIST THROUGH WEDNESDAY NIGHT AND INTO THURSDAY AS
PARADE OF WEAK SHORTWAVES MOVE TROUGH IN THE ZONAL FLOW. EVEN
SHALLOW MIXING ON THURSDAY WOULD SUPPORT MAX TEMPS INTO THE LOWER
40S. WEAK SFC TROUGH TRIES TO MAKE IT ACROSS UPR MICHIGAN LATER
THURSDAY...BUT ONCE IT DOES PUSH ACROSS LK SUPERIOR THURSDAY NIGHT
IT ONLY ENDS UP BEING A SUBTLE WIND SHIFT WITH NO PRECIPITATION.
SINCE H85 TEMPS DO LOWER DOWN TO -4C OVR LK SUPERIOR BY FRIDAY
MORNING INCREASED SKY COVER SOME OVER CONSENSUS WITH SUFFICIENT
OVER-WATER INSTABILITY FOR LK EFFECT CLOUDS. ANY CLOUDS WILL BREAK
UP BY FRIDAY AFTN AS ONCE AGAIN WARMER AIR MOVES BACK IN AS HIGH
PRESSURE RE-ASSERTS ITS INFLUENCE OVER MUCH OF THE EASTERN CONUS.
RIDGE AXIS STAYS TO EAST OF UPR LAKES THROUGH NEXT WEEKEND...SO
EXPECT SOUTH TO SOUTHWEST WINDS AND CONTINUED WARMER THAN NORMAL
TEMPS OVER UPR MICHIGAN. OVERALL A QUIET STRETCH OF WEATHER IN STORE
ONCE EARLY WEEK TROUGHING/WINTRY WEATHER DEPARTS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 640 AM EST MON NOV 12 2012
FOR SAW/IWD...EXPECT VFR WITH OCNL MVFR CONDITIONS DURING THIS FCST
PERIOD IN AT TIMES GUSTY WSW FLOW OF RELATIVELY UNMODIFIED COLD...
BUT DRY LLVL AIRMASS. ALTHOUGH MVFR CIGS WL BE THE RULE AT CMX FOR
MUCH OF TODAY WITH THE FLOW TOO SW TO BRING IN SHSN OFF LK SUP...
THE APRCH/PASSAGE OF A LO PRES TROF/DOMINANT LES BAND LATER TODAY WL
RESULT IN A PERIOD OF LIFR CONDITIONS FOR AT LEAST A COUPLE OF HRS.
GUSTY WINDS AT THIS MORE EXPOSED SITE WL ALSO HAMPER VSBY. PLAN ON
IFR CONDITIONS TO THEN PREDOMINATE THRU THE NGT AT CMX AS LK EFFECT
-SHSN LINGER FOLLOWING THE TROF PASSAGE. THE WINDS/BLSN WL LIKELY
EASE A BIT LATE...WITH MVFR CONDITIONS PSBL AT CMX TOWARD DAYBREAK
ON TUE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EST MON NOV 12 2012
EXPECT WEST WINDS UP TO 30 KTS TO CONTINUE INTO TONIGHT UNDER SHARP
PRES GRADIENT BETWEEN HI PRES IN THE PLAINS AND LO PRES MOVING INTO
HUDSON BAY AND AS VERY COLD AIRMASS SPILLS OVER THE RELATIVELY WARM
WATERS OF LAKE SUPERIOR TO ENHANCE MIXING OF STRONGER WINDS TO THE
SURFACE. THE BEST CHANCE FOR ANY GALE FORCE GUSTS UP TO 35 KTS WILL
BE THRU THIS AFTERNOON ALONG THE W SHORE OF UPR MI...WHERE LOCAL
TERRAIN INFLUENCES WILL TEND TO ENHANCE WIND SPEEDS...AND OVER THE E
HALF THIS AFTERNOON AND TONIGHT. THE WINDS WILL TEND TO DIMINISH
OVER WESTERN LAKE SUPERIOR TONIGHT WITH THE CLOSER APPROACH OF HI
PRES FROM THE PLAINS.
PRESSURE GRADIENT RELAXES FURTHER TUESDAY AND TUESDAY NIGHT ALLOWING
WINDS TO DIMINISH BLO 25 KTS. EXPECT SOUTH WINDS TO INCREASE TO
25-30 KTS ON WEDNESDAY AS LOW PRESSURE TROUGH PUSHES TOWARD ONTARIO
AND HIGH PRESSURE LIFTS FROM OHIO VALLEY INTO QUEBEC. STRONGEST WINDS
ON WEDNESDAY WILL BE OVER EASTERN SECTIONS OF LK SUPERIOR. WINDS
DIMINISH BLO 25 KTS THURSDAY INTO NEXT WEEKEND AS HIGH PRESSURE
BUILDS OVER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
TUESDAY FOR MIZ084.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
TUESDAY FOR MIZ002.
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
640 AM EST MON NOV 12 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EST MON NOV 12 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE UPR
RDG OVER THE PLAINS BTWN RDGS OVER THE E AND THE W. COLD FNT
ATTENDANT TO SFC LO MOVING THRU ONTARIO TOWARD HUDSON BAY AND UNDER
SSW FLOW ALF HAS PUSHED TO JUST E OF A P53-ESC LINE AS OF 06Z. BULK
OF PCPN IN THE FORM OF RA ALONG THIS BNDRY IS OVER THE E HALF OF THE
CWA FORCED BY VIGOROUS UPR DVGC IN RRQ OF 140KT H3 JET MAX OVER NW
ONTARIO AND SHARP LO-MID LVL FGEN LIFTING OF VERY WARM/MOIST AIRMASS
/00Z PWAT NEAR 1 INCH UP TO 250 PCT OF NORMAL/ JUST E OF THE FNT.
ARRIVAL OF COLDER AIR HAS CAUSED A MIX WITH SN OVER THE W HALF...BUT
DRYING ALF WITH 00Z INL/MPX RAOBS SHOWING VERY DRY AIR AOA H75-8 AND
SLGT ACYC SFC FLOW BEHIND THE FNT HAS KEPT THE WINTRY PCPN ON THE
LGT SIDE. FARTHER TO THE W UNDER THE UPR TROF AXIS...A VERY
PRONOUNCED H85-7 THERMAL TROF IS PRESENT WITHIN SHARP CYC FLOW. 00Z
H85/7 TEMPS ARE AS LO AS -17C/-20C IN THE NRN PLAINS...AND 00Z
BISMARCK RAOB SHOWS DEEP MSTR SFC THRU H6.
FCST CONCERNS IN THE SHORT TERM ARE RELATED TO TIMING THE EXIT OF
LARGER SCALE PCPN OVER THE E HALF AND THE DETAILS OF THE TRANSITION
TO AN LES REGIME TDAY THRU TNGT AS COLDER/MOISTER AIR IN THE NRN
PLAINS SWINGS THRU THE UPR LKS UNDER PASSING UPR TROF.
TDAY...WITH THE EXPECTED ARRIVAL OF DRIER AIR ALF...EXPECT ONGOING
SYNOPTIC SCALE PCPN OVER THE FAR E AT ERY TO END ARND 12Z. ARRIVAL
OF WEAK SFC HI PRES RDG UNDER THE DRY AXIS AT H7 SHOULD BRING A
MAINLY DRY PERIOD TO MOST OF THE CWA THIS AFTN...BUT THE ARRIVAL OF
THE DEEPER MSTR/COLDER H85 AIR OVER THE W LATE THIS MRNG WL BRING
INCRSG LES CHCS TO THAT AREA. WITH THE LLVL FLOW BACKING MORE WSW
WITH ARPCH OF SFC TROF...EXPECT A DOMINANT BAND TO FORM OVER THE
LENGTH OF WRN LK SUP WITH H85 TEMPS SINKING TO -13C TO -15C BY 12Z
AND LINGERING THRU THE DAY. IN FACT...A QUICK LOOK AT THE DLH RADAR
AT 0630Z SHOWS WHAT APPEARS TO BE THE START OF THIS LES BAND JUST N
OF THE APOSTLE ISLANDS. INITIALLY...THE BULK OF THE LOCAL HI RES
MODELS INDICATE THE BAND WL REMAIN JUST OFF THE W SHORE OF THE
KEWEENAW WITH SLGT LAND BREEZE COMPONENT/MORE SW FLOW OVER LAND
ASSOCIATED WITH WARMING OVER THE OPEN WATERS MAINTAINING THE SHARPER
LLVL CNVGC THERE AS THE LARGER SCALE FLOW BACKS A BIT AHEAD OF
APRCHG LO PRES TROF. BUT AS THE H925 WINDS BEGIN TO VEER OVER WRN LK
SUP WITH ARRIVAL OF THE TROF THIS AFTN...EXPECT THE HEAVIER BAND TO
COME ASHORE OVER THE W FM THE PORCUPINE MTNS TO THE KEWEENAW.
FAVORABLE OMEGA PROFILE SOLIDLY IN THE DGZ IN CONCERT WITH DEEP MSTR
TO AT LEAST H7/SHARP LLVL CNVGC WL ENHANCE SN RATES WITHIN THIS BAND
AND JUSTIFIES CURRENT ADVY...ESPECIALLY FOR THE W SIDE OF THE
KEWEENAW WHERE THE BAND RESIDENCE TIME MIGHT BE A BIT LONGER.
TNGT...WITH PASSAGE OF LO PRES TROF/VEERING H925 WINDS TO WNW...
EXPECT THE LES OVER THE W TO EVOLVE INTO A MULTIPLE BAND EVENT.
GRADUAL WARMING WITH THE PASSAGE OF THE H85 THERMAL TROF AS WELL AS
FCST SHARPENING/LOWERING INVRN THAT NEARLY DRIES OUT THE DGZ BY 09Z
AS WELL AS DVLPG MORE ACYC FLOW OVER THE W WL CAUSE THE INTENSITY OF
THE LES TO DIMINISH THERE DURING THE EARLY MRNG HRS ON TUE. BUT OVER
THE E...THE VEERING WIND WL ALLOW LES BANDS TO COME ASHORE AT LEAST
N OF M-28. OVER THE CENTRAL CWA...EXPECT NOTHING MORE THAN ISOLD-
SCT -SHSN...WITH JUST QUITE A BIT OF SC IN DOWNSLOPING FLOW OF
RELATIVELY UNMODIFIED COLDER AIRMASS.
AS FOR HEADLINES...THE EXPECTED TIMING OF THE START OF THE LES OVER
THE W INDICATES THE START OF THE GOING ADVY FOR THE THE KEWEENAW AT
12Z IS A BIT TOO EARLY...SO OPTED TO PUSH BACK THE BEGINNING OF THE
ADVY UNTIL 17Z. ALSO DECIDED TO INCLUDE ONTONAGON COUNTY IN THE
HEADLINE AS THE TOWN OF ONTONAGON WL BE IMPACTED BY THE DOMINANT
BAND. SOME OF THE HIER RES MODELS ALSO INDICATE ENHANCED LAND BREEZE
CNVGC TNGT IN THAT COUNTY WITH MORE SW FLOW OF THE COLDER SFC AIR
NEAR THE WI BORDER AND WNW LK MODIFIED WIND JUST TO THE N. SINCE ANY
SHSN WL NOT BEGIN UNTIL LATER IN THE 2ND PERIOD FOR THE E...WL NOT
POST ANY HEADLINE FOR THAT AREA ATTM.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 457 AM EST MON NOV 12 2012
UPPER TROUGH OVER THE GREAT LAKES TO START THE PERIOD MOVES INTO
EASTERN CANADA AND DE-AMPLIFIES BY WEDNESDAY. WHAT IS LEFT IN ITS
WAKE IS A ZONAL SPLIT FLOW PATTERN ALOFT. NORTHERN AND SOUTHERN JET
STREAMS AND RESULTING STORM TRACKS STAY AWAY FROM THE GREAT LAKES
REGION. NO REAL SIGNIFICANT SYSTEMS ARE EXPECTED FOR THE REST OF THE
WEEK AND INTO NEXT WEEKEND.
HAVE LINGERING LK EFFECT SNOW ISSUES TO DEAL WITH INITIALLY ON
TUESDAY. SHORT WINDOW OF MORE FAVORABLE CONDITIONS FOR LES THROUGH
MID-LATE MORNING WITH INVERSION HEIGHT STAYING AROUND 5-6KFT AND
TEMPS AT TOP OF INVERSION AOB -10C. CONVERGENT LOW-LEVEL FLOW ALSO
SUPPORTS POTENTIAL FOR A COUPLE OF DOMINANT BANDS OF SNOW TO AFFECT
EASTERN CWA...MAINLY OVER EASTERN ALGER COUNTY INTO LUCE COUNTY
NORTH OF M-28. A FEW INCHES OF SNOW MAY OCCUR IN THOSE AREAS DURING
THE MORNING HOURS. LOW-LEVEL WARM AIR ADVECTION/LOWERING INVERSION
AND INCREASING ANTI-CYCLONIC LOW-LEVEL FLOW WILL CONSIDERABLY
DIMINISH THE LK EFFECT BY EARLY-MID AFTN. AFT 18Z...925MB WINDS
BACK SOUTH OF WEST...WHICH WILL KICK WHATEVER LES REMAINS OFFSHORE
AND ACROSS CANADIAN SHORELINE NORTH OF WHITEFISH BAY. HIGHER
RESOLUTION MODELS INCLUDING NAM...GEM-REGIONAL AND NCEP WRF-ARW
SUPPORT GENERAL THEME FOR THE EVOLUTION OF THE LK EFFECT. EVEN WITH
DECREASING CLOUDS ELSEWHERE THROUGHOUT THE DAY...LIMITED MIXING AND
COLD NEAR SFC AIR WILL LIMIT RISE TO MAX TEMPS. DESPITE SUNSHINE
BY AFTN...HIGHS WILL ONLY TOP OUT IN THE LOW-MID 30S.
GFS STILL SHOWING POTENTIAL FOR LGT PRECIP ON WEDNESDAY AS H85-H7
WARM AIR ADVECTION TAKES HOLD AS UPPER TROUGH DEPARTS INTO EASTERN
CANADA. GEM-NHEM AND SREF ALSO INDICATE SOME LIGHT QPF. FORECAST
SOUNDINGS INDICATE A LOT OF MOISTURE EXTENDING AS LOW AS H7 BUT LIFT
WITHIN THE MOISTURE IS WEAK AND IT REMAINS QUITE DRY BLO H7.
INCLUDED SLIGHT CHANCES IN THE EAST AS SOUTH FLOW OFF LK MICHIGAN
MAY PROVIDE ENOUGH ADDITIONAL MOISTURE TO LEAD TO LGT RAIN/SNOW
SHOWERS. SREF PROBABILITIES POINTED TO GREATEST CHANCE FOR
MEASURABLE OVER FAR EAST IN THE AFTN. WENT THAT WAY FOR FCST.
MID CLOUDS PERSIST THROUGH WEDNESDAY NIGHT AND INTO THURSDAY AS
PARADE OF WEAK SHORTWAVES MOVE TROUGH IN THE ZONAL FLOW. EVEN
SHALLOW MIXING ON THURSDAY WOULD SUPPORT MAX TEMPS INTO THE LOWER
40S. WEAK SFC TROUGH TRIES TO MAKE IT ACROSS UPR MICHIGAN LATER
THURSDAY...BUT ONCE IT DOES PUSH ACROSS LK SUPERIOR THURSDAY NIGHT
IT ONLY ENDS UP BEING A SUBTLE WIND SHIFT WITH NO PRECIPITATION.
SINCE H85 TEMPS DO LOWER DOWN TO -4C OVR LK SUPERIOR BY FRIDAY
MORNING INCREASED SKY COVER SOME OVER CONSENSUS WITH SUFFICIENT
OVER-WATER INSTABILITY FOR LK EFFECT CLOUDS. ANY CLOUDS WILL BREAK
UP BY FRIDAY AFTN AS ONCE AGAIN WARMER AIR MOVES BACK IN AS HIGH
PRESSURE RE-ASSERTS ITS INFLUENCE OVER MUCH OF THE EASTERN CONUS.
RIDGE AXIS STAYS TO EAST OF UPR LAKES THROUGH NEXT WEEKEND...SO
EXPECT SOUTH TO SOUTHWEST WINDS AND CONTINUED WARMER THAN NORMAL
TEMPS OVER UPR MICHIGAN. OVERALL A QUIET STRETCH OF WEATHER IN STORE
ONCE EARLY WEEK TROUGHING/WINTRY WEATHER DEPARTS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 640 AM EST MON NOV 12 2012
FOR SAW/IWD...EXPECT VFR WITH OCNL MVFR CONDITIONS DURING THIS FCST
PERIOD IN AT TIMES GUSTY WSW FLOW OF RELATIVELY UNMODIFIED COLD...
BUT DRY LLVL AIRMASS. ALTHOUGH MVFR CIGS WL BE THE RULE AT CMX FOR
MUCH OF TODAY WITH THE FLOW TOO SW TO BRING IN SHSN OFF LK SUP...
THE APRCH/PASSAGE OF A LO PRES TROF/DOMINANT LES BAND LATER TODAY WL
RESULT IN A PERIOD OF LIFR CONDITIONS FOR AT LEAST A COUPLE OF HRS.
GUSTY WINDS AT THIS MORE EXPOSED SITE WL ALSO HAMPER VSBY. PLAN ON
IFR CONDITIONS TO THEN PREDOMINATE THRU THE NGT AT CMX AS LK EFFECT
-SHSN LINGER FOLLOWING THE TROF PASSAGE. THE WINDS/BLSN WL LIKELY
EASE A BIT LATE...WITH MVFR CONDITIONS PSBL AT CMX TOWARD DAYBREAK
ON TUE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EST MON NOV 12 2012
EXPECT WEST WINDS UP TO 30 KTS TO CONTINUE INTO TONIGHT UNDER SHARP
PRES GRADIENT BETWEEN HI PRES IN THE PLAINS AND LO PRES MOVING INTO
HUDSON BAY AND AS VERY COLD AIRMASS SPILLS OVER THE RELATIVELY WARM
WATERS OF LAKE SUPERIOR TO ENHANCE MIXING OF STRONGER WINDS TO THE
SURFACE. THE BEST CHANCE FOR ANY GALE FORCE GUSTS UP TO 35 KTS WILL
BE THRU THIS AFTERNOON ALONG THE W SHORE OF UPR MI...WHERE LOCAL
TERRAIN INFLUENCES WILL TEND TO ENHANCE WIND SPEEDS...AND OVER THE E
HALF THIS AFTERNOON AND TONIGHT. THE WINDS WILL TEND TO DIMINISH
OVER WESTERN LAKE SUPERIOR TONIGHT WITH THE CLOSER APPROACH OF HI
PRES FROM THE PLAINS.
PRESSURE GRADIENT RELAXES FURTHER TUESDAY AND TUESDAY NIGHT ALLOWING
WINDS TO DIMINISH BLO 25 KTS. EXPECT SOUTH WINDS TO INCREASE TO
25-30 KTS ON WEDNESDAY AS LOW PRESSURE TROUGH PUSHES TOWARD ONTARIO
AND HIGH PRESSURE LIFTS FROM OHIO VALLEY INTO QUEBEC. STRONGEST WINDS
ON WEDNESDAY WILL BE OVER EASTERN SECTIONS OF LK SUPERIOR. WINDS
DIMINISH BLO 25 KTS THURSDAY INTO NEXT WEEKEND AS HIGH PRESSURE
BUILDS OVER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
TUESDAY FOR MIZ084.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
TUESDAY FOR MIZ002.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST TUESDAY FOR
MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
459 AM EST MON NOV 12 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EST MON NOV 12 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE UPR
RDG OVER THE PLAINS BTWN RDGS OVER THE E AND THE W. COLD FNT
ATTENDANT TO SFC LO MOVING THRU ONTARIO TOWARD HUDSON BAY AND UNDER
SSW FLOW ALF HAS PUSHED TO JUST E OF A P53-ESC LINE AS OF 06Z. BULK
OF PCPN IN THE FORM OF RA ALONG THIS BNDRY IS OVER THE E HALF OF THE
CWA FORCED BY VIGOROUS UPR DVGC IN RRQ OF 140KT H3 JET MAX OVER NW
ONTARIO AND SHARP LO-MID LVL FGEN LIFTING OF VERY WARM/MOIST AIRMASS
/00Z PWAT NEAR 1 INCH UP TO 250 PCT OF NORMAL/ JUST E OF THE FNT.
ARRIVAL OF COLDER AIR HAS CAUSED A MIX WITH SN OVER THE W HALF...BUT
DRYING ALF WITH 00Z INL/MPX RAOBS SHOWING VERY DRY AIR AOA H75-8 AND
SLGT ACYC SFC FLOW BEHIND THE FNT HAS KEPT THE WINTRY PCPN ON THE
LGT SIDE. FARTHER TO THE W UNDER THE UPR TROF AXIS...A VERY
PRONOUNCED H85-7 THERMAL TROF IS PRESENT WITHIN SHARP CYC FLOW. 00Z
H85/7 TEMPS ARE AS LO AS -17C/-20C IN THE NRN PLAINS...AND 00Z
BISMARCK RAOB SHOWS DEEP MSTR SFC THRU H6.
FCST CONCERNS IN THE SHORT TERM ARE RELATED TO TIMING THE EXIT OF
LARGER SCALE PCPN OVER THE E HALF AND THE DETAILS OF THE TRANSITION
TO AN LES REGIME TDAY THRU TNGT AS COLDER/MOISTER AIR IN THE NRN
PLAINS SWINGS THRU THE UPR LKS UNDER PASSING UPR TROF.
TDAY...WITH THE EXPECTED ARRIVAL OF DRIER AIR ALF...EXPECT ONGOING
SYNOPTIC SCALE PCPN OVER THE FAR E AT ERY TO END ARND 12Z. ARRIVAL
OF WEAK SFC HI PRES RDG UNDER THE DRY AXIS AT H7 SHOULD BRING A
MAINLY DRY PERIOD TO MOST OF THE CWA THIS AFTN...BUT THE ARRIVAL OF
THE DEEPER MSTR/COLDER H85 AIR OVER THE W LATE THIS MRNG WL BRING
INCRSG LES CHCS TO THAT AREA. WITH THE LLVL FLOW BACKING MORE WSW
WITH ARPCH OF SFC TROF...EXPECT A DOMINANT BAND TO FORM OVER THE
LENGTH OF WRN LK SUP WITH H85 TEMPS SINKING TO -13C TO -15C BY 12Z
AND LINGERING THRU THE DAY. IN FACT...A QUICK LOOK AT THE DLH RADAR
AT 0630Z SHOWS WHAT APPEARS TO BE THE START OF THIS LES BAND JUST N
OF THE APOSTLE ISLANDS. INITIALLY...THE BULK OF THE LOCAL HI RES
MODELS INDICATE THE BAND WL REMAIN JUST OFF THE W SHORE OF THE
KEWEENAW WITH SLGT LAND BREEZE COMPONENT/MORE SW FLOW OVER LAND
ASSOCIATED WITH WARMING OVER THE OPEN WATERS MAINTAINING THE SHARPER
LLVL CNVGC THERE AS THE LARGER SCALE FLOW BACKS A BIT AHEAD OF
APRCHG LO PRES TROF. BUT AS THE H925 WINDS BEGIN TO VEER OVER WRN LK
SUP WITH ARRIVAL OF THE TROF THIS AFTN...EXPECT THE HEAVIER BAND TO
COME ASHORE OVER THE W FM THE PORCUPINE MTNS TO THE KEWEENAW.
FAVORABLE OMEGA PROFILE SOLIDLY IN THE DGZ IN CONCERT WITH DEEP MSTR
TO AT LEAST H7/SHARP LLVL CNVGC WL ENHANCE SN RATES WITHIN THIS BAND
AND JUSTIFIES CURRENT ADVY...ESPECIALLY FOR THE W SIDE OF THE
KEWEENAW WHERE THE BAND RESIDENCE TIME MIGHT BE A BIT LONGER.
TNGT...WITH PASSAGE OF LO PRES TROF/VEERING H925 WINDS TO WNW...
EXPECT THE LES OVER THE W TO EVOLVE INTO A MULTIPLE BAND EVENT.
GRADUAL WARMING WITH THE PASSAGE OF THE H85 THERMAL TROF AS WELL AS
FCST SHARPENING/LOWERING INVRN THAT NEARLY DRIES OUT THE DGZ BY 09Z
AS WELL AS DVLPG MORE ACYC FLOW OVER THE W WL CAUSE THE INTENSITY OF
THE LES TO DIMINISH THERE DURING THE EARLY MRNG HRS ON TUE. BUT OVER
THE E...THE VEERING WIND WL ALLOW LES BANDS TO COME ASHORE AT LEAST
N OF M-28. OVER THE CENTRAL CWA...EXPECT NOTHING MORE THAN ISOLD-
SCT -SHSN...WITH JUST QUITE A BIT OF SC IN DOWNSLOPING FLOW OF
RELATIVELY UNMODIFIED COLDER AIRMASS.
AS FOR HEADLINES...THE EXPECTED TIMING OF THE START OF THE LES OVER
THE W INDICATES THE START OF THE GOING ADVY FOR THE THE KEWEENAW AT
12Z IS A BIT TOO EARLY...SO OPTED TO PUSH BACK THE BEGINNING OF THE
ADVY UNTIL 17Z. ALSO DECIDED TO INCLUDE ONTONAGON COUNTY IN THE
HEADLINE AS THE TOWN OF ONTONAGON WL BE IMPACTED BY THE DOMINANT
BAND. SOME OF THE HIER RES MODELS ALSO INDICATE ENHANCED LAND BREEZE
CNVGC TNGT IN THAT COUNTY WITH MORE SW FLOW OF THE COLDER SFC AIR
NEAR THE WI BORDER AND WNW LK MODIFIED WIND JUST TO THE N. SINCE ANY
SHSN WL NOT BEGIN UNTIL LATER IN THE 2ND PERIOD FOR THE E...WL NOT
POST ANY HEADLINE FOR THAT AREA ATTM.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 457 AM EST MON NOV 12 2012
UPPER TROUGH OVER THE GREAT LAKES TO START THE PERIOD MOVES INTO
EASTERN CANADA AND DE-AMPLIFIES BY WEDNESDAY. WHAT IS LEFT IN ITS
WAKE IS A ZONAL SPLIT FLOW PATTERN ALOFT. NORTHERN AND SOUTHERN JET
STREAMS AND RESULTING STORM TRACKS STAY AWAY FROM THE GREAT LAKES
REGION. NO REAL SIGNIFICANT SYSTEMS ARE EXPECTED FOR THE REST OF THE
WEEK AND INTO NEXT WEEKEND.
HAVE LINGERING LK EFFECT SNOW ISSUES TO DEAL WITH INITIALLY ON
TUESDAY. SHORT WINDOW OF MORE FAVORABLE CONDITIONS FOR LES THROUGH
MID-LATE MORNING WITH INVERSION HEIGHT STAYING AROUND 5-6KFT AND
TEMPS AT TOP OF INVERSION AOB -10C. CONVERGENT LOW-LEVEL FLOW ALSO
SUPPORTS POTENTIAL FOR A COUPLE OF DOMINANT BANDS OF SNOW TO AFFECT
EASTERN CWA...MAINLY OVER EASTERN ALGER COUNTY INTO LUCE COUNTY
NORTH OF M-28. A FEW INCHES OF SNOW MAY OCCUR IN THOSE AREAS DURING
THE MORNING HOURS. LOW-LEVEL WARM AIR ADVECTION/LOWERING INVERSION
AND INCREASING ANTI-CYCLONIC LOW-LEVEL FLOW WILL CONSIDERABLY
DIMINISH THE LK EFFECT BY EARLY-MID AFTN. AFT 18Z...925MB WINDS
BACK SOUTH OF WEST...WHICH WILL KICK WHATEVER LES REMAINS OFFSHORE
AND ACROSS CANADIAN SHORELINE NORTH OF WHITEFISH BAY. HIGHER
RESOLUTION MODELS INCLUDING NAM...GEM-REGIONAL AND NCEP WRF-ARW
SUPPORT GENERAL THEME FOR THE EVOLUTION OF THE LK EFFECT. EVEN WITH
DECREASING CLOUDS ELSEWHERE THROUGHOUT THE DAY...LIMITED MIXING AND
COLD NEAR SFC AIR WILL LIMIT RISE TO MAX TEMPS. DESPITE SUNSHINE
BY AFTN...HIGHS WILL ONLY TOP OUT IN THE LOW-MID 30S.
GFS STILL SHOWING POTENTIAL FOR LGT PRECIP ON WEDNESDAY AS H85-H7
WARM AIR ADVECTION TAKES HOLD AS UPPER TROUGH DEPARTS INTO EASTERN
CANADA. GEM-NHEM AND SREF ALSO INDICATE SOME LIGHT QPF. FORECAST
SOUNDINGS INDICATE A LOT OF MOISTURE EXTENDING AS LOW AS H7 BUT LIFT
WITHIN THE MOISTURE IS WEAK AND IT REMAINS QUITE DRY BLO H7.
INCLUDED SLIGHT CHANCES IN THE EAST AS SOUTH FLOW OFF LK MICHIGAN
MAY PROVIDE ENOUGH ADDITIONAL MOISTURE TO LEAD TO LGT RAIN/SNOW
SHOWERS. SREF PROBABILITIES POINTED TO GREATEST CHANCE FOR
MEASURABLE OVER FAR EAST IN THE AFTN. WENT THAT WAY FOR FCST.
MID CLOUDS PERSIST THROUGH WEDNESDAY NIGHT AND INTO THURSDAY AS
PARADE OF WEAK SHORTWAVES MOVE TROUGH IN THE ZONAL FLOW. EVEN
SHALLOW MIXING ON THURSDAY WOULD SUPPORT MAX TEMPS INTO THE LOWER
40S. WEAK SFC TROUGH TRIES TO MAKE IT ACROSS UPR MICHIGAN LATER
THURSDAY...BUT ONCE IT DOES PUSH ACROSS LK SUPERIOR THURSDAY NIGHT
IT ONLY ENDS UP BEING A SUBTLE WIND SHIFT WITH NO PRECIPITATION.
SINCE H85 TEMPS DO LOWER DOWN TO -4C OVR LK SUPERIOR BY FRIDAY
MORNING INCREASED SKY COVER SOME OVER CONSENSUS WITH SUFFICIENT
OVER-WATER INSTABILITY FOR LK EFFECT CLOUDS. ANY CLOUDS WILL BREAK
UP BY FRIDAY AFTN AS ONCE AGAIN WARMER AIR MOVES BACK IN AS HIGH
PRESSURE RE-ASSERTS ITS INFLUENCE OVER MUCH OF THE EASTERN CONUS.
RIDGE AXIS STAYS TO EAST OF UPR LAKES THROUGH NEXT WEEKEND...SO
EXPECT SOUTH TO SOUTHWEST WINDS AND CONTINUED WARMER THAN NORMAL
TEMPS OVER UPR MICHIGAN. OVERALL A QUIET STRETCH OF WEATHER IN STORE
ONCE EARLY WEEK TROUGHING/WINTRY WEATHER DEPARTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1236 AM EST MON NOV 12 2012
LOOK FOR PREVAILING MVFR CONDITIONS THROUGH MUCH OF THE TAF PD AT
KIWD. PREVAILING MVFR CONDITIONS AT KCMX WILL LIKELY GIVE WAY TO
LIFR CONDITIONS BY LATE MON AFTERNOON AS AN INTENSE LES BAND MOVES
ONSHORE REDUCING VBSYS TO AROUND 1/2MI IN SHSN AND BLSN. AS THE BAND
SAGS SE OF THE AREA VSBYS SHOULD IMPROVE TO IFR BY LATE EVENING. AT
KSAW EXPECT MVFR CONDITIONS TO IMPROVE TO VFR BY MIDDAY MONDAY WITH
INCREASING DRYING AND DIURNAL HEATING. WRLY WINDS WILL GUST AOA 25
KTS AT KCMX THROUGH MUCH OF THE TAF PD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EST MON NOV 12 2012
EXPECT WEST WINDS UP TO 30 KTS TO CONTINUE INTO TONIGHT UNDER SHARP
PRES GRADIENT BETWEEN HI PRES IN THE PLAINS AND LO PRES MOVING INTO
HUDSON BAY AND AS VERY COLD AIRMASS SPILLS OVER THE RELATIVELY WARM
WATERS OF LAKE SUPERIOR TO ENHANCE MIXING OF STRONGER WINDS TO THE
SURFACE. THE BEST CHANCE FOR ANY GALE FORCE GUSTS UP TO 35 KTS WILL
BE THRU THIS AFTERNOON ALONG THE W SHORE OF UPR MI...WHERE LOCAL
TERRAIN INFLUENCES WILL TEND TO ENHANCE WIND SPEEDS...AND OVER THE E
HALF THIS AFTERNOON AND TONIGHT. THE WINDS WILL TEND TO DIMINISH
OVER WESTERN LAKE SUPERIOR TONIGHT WITH THE CLOSER APPROACH OF HI
PRES FROM THE PLAINS.
PRESSURE GRADIENT RELAXES FURTHER TUESDAY AND TUESDAY NIGHT ALLOWING
WINDS TO DIMINISH BLO 25 KTS. EXPECT SOUTH WINDS TO INCREASE TO
25-30 KTS ON WEDNESDAY AS LOW PRESSURE TROUGH PUSHES TOWARD ONTARIO
AND HIGH PRESSURE LIFTS FROM OHIO VALLEY INTO QUEBEC. STRONGEST WINDS
ON WEDNESDAY WILL BE OVER EASTERN SECTIONS OF LK SUPERIOR. WINDS
DIMINISH BLO 25 KTS THURSDAY INTO NEXT WEEKEND AS HIGH PRESSURE
BUILDS OVER GREAT LAKES. &&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
TUESDAY FOR MIZ084.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
TUESDAY FOR MIZ002.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST TUESDAY FOR
MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...VOSS
MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1237 AM EST MON NOV 12 2012
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 442 PM EST SUN NOV 11 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A DEEP TROF EXTENDING FROM
SCNTRL CANADA THRU THE WRN PLAINS. DEEP SRLY FLOW THAT HAS BEEN
OCCURRING AHEAD OF THE TROF HAS TRANSPORTED ABUNDANT MOISTURE N INTO
THE WRN GREAT LAKES. 12Z RAOBS SHOW PRECIPITABLE WATER RUNNING
200-275PCT OF NORMAL OVER THE WRN GREAT LAKES. AT THE SFC...SHARP
COLD FRONT EXTENDS FROM CNTRL LAKE SUPERIOR TO JUST E OF THE
KEWEENAW AND THEN S TO THE W OF KIMT. SHARP FRONT PLOWING INTO DEEP
MOISTURE COMBINED WITH HEALTHY UPPER DIVERGENCE ASSOCIATED WITH
130-140KT UPPER JET STREAK LIFTING UP FRONT SIDE OF TROF HAS
RESULTED IN A SOLID BAND OF SHRA ALONG THE COLD FRONT TODAY. BEHIND
THE FRONT...TEMP HAS ALREADY PLUMMETED TO 37 AT KIWD WHERE RAIN IS
JUST ABOUT DONE.
THERE ARE PLENTY OF CONCERNS IN THE SHORT TERM...RANGING FROM
PROGRESSION OF RAIN BAND E ACROSS THE AREA TONIGHT...POSSIBLE BRIEF
WINTRY MIX ON THE BACKSIDE OF THE RAIN...AND THEN TRANSITION TO LES
AND POSSIBLE WINTER WX HEADLINE MON.
FCST FOR THIS EVENING IS LARGELY BASED ON EXTRAPOLATION OF SHRA.
SINCE UPPER DIVERGENCE OVERTOP SHARP COLD FRONT WILL ALLOW SHRA TO
PERSIST ALONG FRONT AS IT MOVES E...WILL SPREAD CATEGORICAL POPS
STEADILY E ACROSS THE CNTRL AND ERN FCST AREA TONIGHT IN ASSOCIATION
WITH SFC COLD FRONT WHICH SHOULD REACH THE SOO LATE TONIGHT. PCPN
ACROSS THE W AND CNTRL WILL END AS RIBBON OF PRONOUNCED MIDLEVEL
DRYING FOLLOWS UPPER JET STREAK TRANSLATING ACROSS THE AREA. BEFORE
PCPN ENDS...THERE IS A SMALL WINDOW FOR A LITTLE SLEET THEN SNOW TO
OCCUR AS INITIALLY SHALLOW COLD AIR UNDERCUTS THE LINGERING WARMER
AIR ALOFT. HOWEVER...THERE ISN`T MUCH SIGNAL FOR SUFFICIENT FORCING
TOO FAR W OF THE COLD FRONT TO COUNTER THE SHARP MID LEVEL DRYING
AND KEEP PCPN LINGERING IN THE COLD AIR FOR TOO LONG. ANY SLEET OR
SNOW THAT DOES OCCUR ON THE BACKSIDE OF THE MAIN FRONTAL SHRA BAND
SHOULDN`T AMOUNT TO MUCH IF ANYTHING. THE MIXED PCPN POTENTIAL WILL
SPREAD INTO THE ERN FCST AREA LATE TONIGHT AS MODELS ARE A LITTLE
FASTER WITH CAA. LINGERING LIGHT PCPN OVER THE E SHOULD END BY MID
MORNING MON.
AS MAIN SYNOPTIC PCPN EXITS...ATTENTION TURNS TO LAKE EFFECT SNOW.
WITH SFC WATER TEMPS OVER WRN LAKE SUPERIOR AROUND 6C...MODEL
CONSENSUS IS FOR 850MB TEMPS TO FALL SUFFICIENTLY FOR LES
DEVELOPMENT AFTER 06Z...BUT MORE SO BTWN 09-12Z AS TEMPS WILL BE
DOWN TO -12 TO -14C AT 12Z. MIDLEVEL DRY SLOT WILL INITIALLY WORK TO
KEEP COVERAGE MORE LIMITED. SO SCT COVERAGE POPS FOR -SHSN APPEAR ON
TRACK FOR THE OVERNIGHT.
LES FCST GETS MORE INTERESTING MON AS MID LEVEL TROF AXIS AND POOL
OF DEEP MOISTURE ARRIVES. THIS RESULTS IN INVERSION LIFTING TOWARD
10KFT. WITH 850MB TEMPS AVERAGING AROUND -13C THRU THE DAY...DGZ
ENDS UP WITHIN THE MOIST CONVECTIVE LAYER...AND AT LEAST WITH THE
NAM...THERE IS A NICE INTERSECTION OF UPWARD MOTION THRU THE DGZ.
WIND DIRECTION WILL BE CRITICAL. VARIOUS HIGH RES MODELS (LOCAL HIGH
RES WRF AND NCEP HIGH RES ARW/NMM) INCLUDING NAM/REGIONAL GEM ARE IN
GOOD AGREEMENT SHOWING MORE OF A WSW WIND OVER WRN LAKE SUPERIOR AND
ARE SUGGESTIVE OF A DOMINANT CONVERGENT BAND DEVELOPING NEAR THE
APOSTLE ISLANDS AND STREAMING TOWARD THE NRN PORTION OF THE KEWEENAW
PENINSULA MON...WHICH IS A COMMON OCCURRENCE FOR THIS TYPE OF
LOW-LEVEL WIND FLOW. GIVEN THE AGREEMENT...HAVE FOLLOWED THIS
SCENARIO. WITH POTENTIAL OF MDT TO PERHAPS HVY LAKE ENHANCED SNOW AT
TIMES GIVEN FAVORABLE TEMP/MOISTURE PROFILE...OPTED TO GO WITH A
WINTER WX ADVY FOR NRN HOUGHTON/KEWEENAW COUNTIES MON. EXPECT MAIN
FOCUS OF HEAVIER LES TO BE N OF HOUGHTON...PARTICULARLY IN THE AFTN
OVER THE HIGHER TERRAIN FROM AROUND CALUMET THRU DELAWARE WHERE SNOW
MAY ACCUMULATE TO AROUND 4 INCHES DURING THE DAY MON. VERY LATE IN THE
AFTN...WINDS WILL BEGIN TO SHIFT MORE TO THE W WHICH WILL PUSH
HEAVIER SNOW OVER MORE OF THE KEWEENAW PENINSULA. SINCE ONTONAGON
COUNTY WILL BE SOUTH OF THE HEAVIER SNOW AND POSSIBLY S OF MOST OF
THE LAKE ENHANCED SNOW...DID NOT INCLUDE ADVY FOR THAT AREA AT THIS
TIME. TO THE E...WINDS WILL PROBABLY HAVE ENOUGH OFFSHORE COMPONENT
TO KEEP MOST OF THE DEVELOPING LAKE ENHANCED SNOW OFFSHORE OF
ALGER/LUCE COUNTIES. ELSEWHERE...EXPECT SCT FLURRIES/-SHSN TO
ACCOMPANY ARRIVAL OF MIDLEVEL TROF OVER ROUGHLY THE W HALF OF UPPER
MI MON. WITH 850MB THERMAL TROF MOVING OVER THE AREA...TEMPS SHOULD
RISE VERY LITTLE. IN FACT...TO THE W...TEMPS THIS AFTN ARE ONLY IN
THE UPPER TEENS/LWR 20S IN THE ERN DAKOTAS/WRN MN. SO...TEMPS LIKELY
WON`T RISE OUT OF THE MID/UPPER 20S OVER WRN UPPER MI MON...AND
TEMPS MAY FALL SOME OVER THE E AS CAA CONTINUES THRU THE MORNING IN
THAT AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 442 PM EST SUN NOV 11 2012
NOT MUCH CHANGE TO PREVIOUS FORECAST THINKING IN THE LONG TERM WITH
MAIN FOCUS MON NIGHT INTO TUE WITH LES.
A SHARP UPPER TROUGH WILL BE OVER THE CENTRAL CWA /E OF THE
KEWEENAW/ AT 00Z TUE WITH A SLIGHTLY LAGGING SFC TROUGH OVER WRN
LAKE SUPERIOR. COLD AIR ASSOCIATED WITH THIS TROUGH CAUSES CONCERN
WITH CHANCES FOR LES PARTICULARLY OVER THE KEWEENAW PENINSULA. 850MB
TEMPS WILL BE AROUND -11C AT 00Z TUE...WITH THE TOP OF THE INVERSION
ABOVE THE DGZ AT AROUND 9500FT WITH TEMPS AROUND -24C. WHILE 850MB
TEMPS WILL BE A COUPLE OF DEGREES WARMER THAT A FEW HOURS
BEFORE...THE INVERSION LOOKS TO BE DEEPEST AROUND 00Z TUE...SO BEST
OVERALL AVG COVERAGE/INTENSITY SHOULD BE SEEN AROUND THIS TIME.
AFTER 00Z TUE...A SFC RIDGE WILL MOVE OVERHEAD BY 18Z TUE WITH 850MB
TEMPS STEADILY INCREASING TO AOA -5C BY 00Z WED. MOISTURE...WHICH
WILL BE AMPLE FOR LES AT 00Z...WILL DECREASE AFTER 00Z TUE. MOISTURE
FROM 850MB AND UP WILL DECREASE TO BELOW 60 PERCENT RH OVER THE WRN
HALF OF LAKE SUPERIOR BY 09Z TUE...AND OVER THE ENTIRE LAKE BY 15Z
TUE. 925MB-850MB RH DECREASES BELOW 60 PERCENT OVER THE WRN HALF OF
LAKE SUPERIOR BY 15Z TUE...AND THE MOST OF THE REST OF THE LAKE BY
00Z WED. AT LEAST FROM 00Z TUE TO 06Z WED...WINDS LOOK TO GUST TO
35-40MPH OVER THE KEWEENAW PENINSULA WITH THE W WINDS. COLD SECTOR
LIVING AT ITS BEST.
TAKING A CLOSER LOOKS AT SNOWFALL AMOUNTS AND OTHER HAZARDS FOR TUE
NIGHT...LOW LEVEL WINDS WILL BE FAIRLY UNIDIRECTIONAL...WHICH IS
GOOD FOR LES BANDING. HOWEVER...WINDS WILL BE SHIFTING FROM A WSW
DIRECTION MON EVENING...WHICH WILL FAVOR A DOMINANT BAND WITH
INTENSE SNOWFALL AMOUNTS LATE MON. THOSE WSW WINDS BECOME MORE WLY
BY 00Z TUE AND SLOWLY VEER INTO TUE AS THE RIDGE MOVES IN FROM THE
W. THIS WILL MOVE THE WEAKENING DOMINANT BAND FROM N TO S ACROSS THE
KEWEENAW AND INTO ONTONAGON COUNTY MON NIGHT...BUT THE FACT THAT
WINDS WILL STEADILY VEER WILL KEEP THE STRONGER BAND FROM SITTING
OVER ANY ONE PLACE FOR TOO LONG...HELPING TO KEEP SNOWFALL TOTALS
FROM GETTING TO HIGH. THE BEST AREA OF LIFT WILL SPAN THE
DGZ...WHICH WILL HELP MAKE SNOW TO LIQUID RATIOS HIGH...BUT GUSTY
WINDS WILL KNOCK THOSE DOWN SOME. EXPECT SLR VALUES AROUND 18-20 TO
1. ADDITIONAL SNOWFALL AMOUNTS MON NIGHT /ON TOP OF WHAT FALL MON/
LOOK TO BE UP TO AROUND 4 INCHES...HIGHEST OVER THE HIGHER TERRAIN
FROM ROCKLAND TO SOUTH RANGE. WITH THE WINDS...BLOWING SNOW WILL
ALSO BE AN ISSUE...BUT A LIMITED ONE GIVEN NO SNOW ON THE GROUND
YET. AS FOR THE TUE MORNING COMMUTE OVER THE KEWEENAW...BY 12Z TUE
WINDS WILL HAVE DIMINISHED TO 20MPH OR LESS AND SNOWFALL RATES
SHOULD BE GREATLY REDUCED...SO CONDITIONS WILL MAINLY DEPEND ON HOW
WELL ROAD CREWS CAN CLEAR EARLIER SNOW OFF THE ROADS...BUT AT LEAST
SLICK ROADS APPEAR LIKELY.
WITH THE WINDS BECOMING MORE WNW THROUGH THE NIGHT...THE ERN CWA
NEAR LAKE SUPERIOR /MAINLY E OF MUNISING/ SHOULD SEE SOME MODERATE
TO HEAVY SNOWFALL AS WELL. THE FORECAST IS A BIT TRICKIER OVER
THERE...MAINLY DUE TO UNCERTAINTY WITH WHEN AND HOW FAR LES BAND
WILL MOVE ONSHORE. SIMILAR TO THE KEWEENAW THERE SHOULD BE A MORE
DOMINANT BAND SITTING OVER ERN LAKE SUPERIOR THAT WILL PUSH ONSHORE
AS CONDITIONS START TO BECOME LESS FAVORABLE FOR LES. PUSH
CONDITIONS BACK A FEW HOURS FROM TIMING OVER THE KEWEENAW...SO THE
BAND SHOULD BEGIN TO VEER ONSHORE AROUND 06Z TUE...BUT SHOULD BEGIN
WEAKENING SHORTLY DUE TO DRIER AIR AND MORE ANTICYCLONIC FLOW
GRADUALLY MOVING IN. COULD SEE TOTAL SNOWFALL AMOUNTS OF 3-4 INCHES
MON NIGHT INTO TUE.
HAVE A WINTER WX ADV THAT EXTENDS TO 12Z TUE FOR NRN HOUGHTON AND
KEWEENAW COUNTIES. WILL POSSIBLY NEED AN ADV FOR ONTONAGON AND MAYBE
SOUTHERN HOUGHTON COUNTY MON NIGHT...BUT WILL LEAVE THOSE DETAILS TO
MIDNIGHT SHIFT AND HIGHLIGHT IN HWO. ALSO MAY NEED AN ADV FOR PARTS
OF THE ERN CWA CLOSE TO LAKE SUPERIOR...BUT THOSE DETAILS ARE EVEN
LESS CERTAIN.
WITH FAIRLY BENIGN...LOW IMPACT WEATHER AFTER CONDITIONS SUBSIDE
TUE...JUST USED A CONSENSUS OF THE MODELS FOR THE REST OF THE
FORECAST SO AS TO PLACE MOST TIME/EMPHASIS ON SHORTER TERM IMPACTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1236 AM EST MON NOV 12 2012
LOOK FOR PREVAILING MVFR CONDITIONS THROUGH MUCH OF THE TAF PD AT
KIWD. PREVAILING MVFR CONDITIONS AT KCMX WILL LIKELY GIVE WAY TO
LIFR CONDITIONS BY LATE MON AFTERNOON AS AN INTENSE LES BAND MOVES
ONSHORE REDUCING VBSYS TO AROUND 1/2MI IN SHSN AND BLSN. AS THE BAND
SAGS SE OF THE AREA VSBYS SHOULD IMPROVE TO IFR BY LATE EVENING. AT
KSAW EXPECT MVFR CONDITIONS TO IMPROVE TO VFR BY MIDDAY MONDAY WITH
INCREASING DRYING AND DIURNAL HEATING. WRLY WINDS WILL GUST AOA 25
KTS AT KCMX THROUGH MUCH OF THE TAF PD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 442 PM EST SUN NOV 11 2012
SHARP COLD FRONT IS IN THE PROCESS OF CROSSING LAKE SUPERIOR ATTM.
AHEAD OF THE FRONT...S WINDS OVER ERN LAKE SUPERIOR WILL GUST TO
GALE FORCE AT TIMES THIS EVENING...ESPECIALLY IN THE AREA AROUND
GRAND MARAIS WHICH IS FAVORED FOR STRONG WINDS IN SOUTHERLY FLOW.
ALTHOUGH CAA IS STRONG BEHIND COLD FRONT...LACK OF STRONGER SFC PRES
RISES WILL PROBABLY RESULT IN WESTERLY WINDS REMAINING BLO GALE
FORCE TONIGHT. PRESSURE GRADIENT TIGHTENS JUST A BIT ON MON AS
SECONDARY SFC TROF APPROACHES. WITH COLD AIR AND UNSTABLE
LOW-LEVELS...OCNL GALE FORCE GUSTS TO 35KT ARE POSSIBLE MON/MON
EVENING. PRESSURE GRADIENT THEN SLACKENS LATE MON NIGHT/TUE WITH
WINDS DIMINISHING BLO 25 KTS. A LOW PRES TROF WILL PUSH ACROSS
NORTHERN ONTARIO THU. S WINDS AHEAD OF THE TROF COULD REACH 25 KTS
OVER EASTERN SECTIONS OF LAKE SUPERIOR WED/WED NIGHT. WINDS TO
FINISH UP THE WEEK WILL BE BLO 20 KTS AS PRESSURE GRADIENT BECOMES
WEAK WITH SFC HIGH PRES PASSING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 7 AM EST
TUESDAY FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...VOSS
MARINE...ROLFSON
BELIEVE IT OR NOT...THE BIGGEST FORECAST DISCUSSION TOPIC TODAY
AMONGST DLH/ARX AND OUR OFFICE WAS WHETHER OR NOT TO INCLUDE
FLURRIES ...SPRINKLES OR FREEZING SPRINKLES FOR A 3-6 WINDOW
TONIGHT. THAT SHOULD BE SOME INDICATION AS TO HOW QUIET THE
PATTERN WILL BE OVER THE COMING DAYS. THE 12Z GEM/GFS BOTH AGREE
THERE WILL BE SATURATION OVER A DEEP ENOUGH LAYER TO PRODUCE LIGHT
PRECIP OUT AHEAD OF THE APPROACHING SHORTWAVE. THE 12Z NAM/ECMWF
DO NOT GENERATE PRECIP. THERE ARE PLENTY OF MID CLOUDS IN THE
DAKOTAS AND NEBRASKA OUT THERE NOW WITH THAT SHORTWAVE...BUT
LITTLE UNDER 7000 FT AND THAT HAS BEEN THE QUESTION THE PAST
COUPLE DAYS. CAN WE GET ANYTHING BESIDES VIRGA? WE DECIDED TO
THROW IN A FEW SPRINKLES/FLURRIES OVER A SMALL AREA IN EASTERN MN
AND WESTERN WI. THE REASON BEING...EVEN THE DRIER NAM/RUC DO SHOW
DECENT MOISTURE CONVERGENCE IN THE 850-700MB LAYER FROM 03-09Z
TONIGHT. A LITTLE LIGHT PRECIP SEEMS REASONABLE. DLH HAS FREEZING
DRIZZLE IN THE FORECAST TO ACCOUNT FOR A WARM LAYER ABOVE THE
SURFACE AND NEAR FREEZING TEMPS AT THE SURFACE. IT WOULD NOT BE
DRIZZLE DROPS GIVEN THE DRY LOWER ATMOSPHERE...IT WOULD ACTUALLY
BE LIGHT FREEZING RAIN. WE WENT WITH FLURRIES AND SPRINKLES...THE
WET BULB SHOULDN`T BE TOO MUCH OF A FACTOR GIVEN HOW LIGHT THE
PRECIP WOULD BE...BUT I SUPPOSE THERE COULD BE ENOUGH COOLING TO
KEEP THE PROFILE COLD ENOUGH FOR FLURRIES. I THINK MOST LIKELY
LITTLE TO NOTHING WILL HAPPEN SO PTYPE IS IRRELEVANT.
MILD AND DRY FROM WEDNESDAY THROUGH AT LEAST THE WEEKEND. THE
PATTERN DOES APPEAR TO BECOME MORE ACTIVE NEXT WEEK AS WE HEAD
TOWARD THE HOLIDAY...HOWEVER THE GFS/ECMWF SOLUTIONS REALLY START
TO DIVERGE 150 HOURS OUT...SO HARD TO PUT MUCH CONFIDENCE IN
ANYTHING PAST SUNDAY. THE SPREAD OFF THE GFS IS ALSO SIGNIFICANT
EARLY NEXT WEEK WITH 10-12 MB DIFFERENCES IN MSLP.
&&
.AVIATION.../00Z TAF ISSUANCE/
BROAD AREA OF MID LEVEL CLOUDS WITH CEILINGS 070-100 ASSOCIATED
WITH SHORT WAVE NOW OVER DAKOTAS AND MN. THIS WILL MOVE EAST AND
CLOUDS WILL SCATTER OUT BETWEEN 10Z IN WRN MN TO AROUND 16Z IN WRN
WISC. LIGHT SOUTH WINDS THROUGHOUT WITH SOME LIGHT SE OR SW AT
TIMES AS WEAK SURFACE TROUGH IN WRN MN WASHES OUT. JUST A SLIGHT
CHANCE OF LIGHT PRECIP IN WISC...MAYBE ZR...BUT NOT ENOUGH TO ADD
TO TAFS AT THIS POINT. WILL ONLY MENTION SOME LOWER CEILINGS
AROUND 050-060 FOR NOW AT KEAU AND KRNH.
KMSP...VFR THROUGHOUT PERIOD...WITH BKN-OVC MID CLOUDS SCATTERING
OUT AROUND 14Z. THERE IS A SLIGHT CHANCE OF VERY LIGHT ZR AFTER
06Z BUT THAT SHOULD REMAIN WELL NORTH/EAST OF KMSP.
/OUTLOOK FOR KMSP/
THU...VFR. WINDS SW 5-10 KTS BECOMING NW AFTER 18Z.
FRI...VFR. WINDS CALM BECOMING SE AROUND 5 KTS.
SAT...VFR. WINDS S 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/CLF/TDK
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1141 PM CST Sun Nov 11 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Short Range (Tonight through Tuesday):
Impressive upper trough moving east through the Plains late this
afternoon. Best lift/sensible weather occurring well downstream over
the mid MO River Valley where mixed precipitation is falling. The
combination of significant cold air advection through the entire
column, elevated frontogenesis and increasing upper level jet
dynamics has allowed sleet to form on the western edge of the rain
shield. Short range models, HRRR, RAP and NAM all clear out the
precipitation over the eastern counties by 03Z. Have slowed down the
end of the precipitation slightly due to the positive tilt of the
upper trough and the associated strong upper level jet dynamics.
Weather looking pretty tranquil after the upper trough axis passes
through the CWA early Monday. Strong subsidence on the back side of
the trough should greatly limit the effects of a secondary vorticity
lobe sliding through eastern NE/KS during the day. Although the
models show warm air advection occurring on Monday its effects will
be muted due to such a cold start to the day.
A semi-zonal flow pattern will ensue over the central U.S. by Monday
night and continue into mid week. A fast moving shortwave embedded
within this flow will streak through KS/NE/IA/MO on Tuesday,
However, moisture will be limited, especially within the boundary
layer so should only see a modest pick up in clouds with moderate
warm air advection resulting in seasonally average temperatures.
MJ
Medium Range (Wednesday through Sunday):
A few troughs may drop through primarily zonal flow during the
latter half of the week; however, with dry surface high pressure
sitting over the southeastern U.S, precipitation chances look very
low through at least Saturday. Temperatures should hover around to a
few degrees below normal in the absence of any amplified troughing
or ridging through the Plains, with highs mainly in the 50`s and
lows in the 30`s.
As the surface high weakens and gradually slides eastward Saturday,
both the EC and GFS bringing a shortwave trough into Nebraska and
eastern Kansas, potentially fueling widespread but light, scattered
precipitation especially across the western half of the CWA. Aloft,
temperatures look warm enough for a liquid precipitation type across
the region, especially without any deep cold air poised to filter in
behind the system.
Laflin
&&
.AVIATION...
For the 06Z TAFs...VFR conditions will prevail at the terminals over
the next 24 hours as cold and dry Canadian air sweeps through the
region. Otherwise, watch for light winds overnight to become gusty by
the afternoon hours Monday, only to go light and variable after sunset
Monday.
Cutter
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
600 PM EST MON NOV 12 2012
.SYNOPSIS...
UNSEASONABLE WARMTH WILL PERSIST TODAY EVEN THOUGH CLOUDS WILL
BE ON THE INCREASE. A COLD FRONT MOVES ACROSS THE EASTERN
CAROLINAS ON TUESDAY...BRINGING AN EXTENDED PERIOD OF CLOUDY AND
COOL WEATHER THAT MAY LAST INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6:00 PM MONDAY...THE CAROLINAS REMAIN SANDWICHED BETWEEN A
DEPARTING LARGE HIGH PRESSURE OFF TO THE NORTHEAST...AND AN
ADVANCING COLD FRONT FROM THE WEST. THIS IS CREATING WARM AND MOIST
ADVECTION INTO THE ILM CWA...WITH ISOLATED ADVECTION SHOWERS AND
TEMPS RISING WELL INTO THE 70S TO NEAR 80 DEGREES THIS AFTN.
SHOWERS DEVELOPING OVER THE MOIST ATLANTIC ON THE E/SE RETURN FLOW
WILL GRADUALLY DISSIPATE THROUGH THIS EVE AS WINDS BECOME MORE
SOUTHERLY...MEANING LESS OF A FETCH ACROSS THE OCEAN. WILL CONTINUE
SCHC POP...MAINLY ALONG THE COAST...THROUGH NIGHTFALL BEFORE
DECREASING INSTABILITY AND A MORE SOUTHERLY WIND TRAJECTORY WILL
HELP SQUELCH MOST SHOWERS. THIS IS SHOWN WELL BY THE HRRR AND ARW
THIS AFTN. BEST CHANCE FOR SHOWERS THROUGH TONIGHT WILL BE ALONG THE
CAPE FEAR COAST...BUT EVEN THESE WILL CARRY VERY LITTLE QPF.
SOUTHERLY WINDS WILL REMAIN ELEVATED TONIGHT AS GRADIENT TIGHTENS
AHEAD OF THE APPROACHING COLD FRONT. THIS WARM SOUTHERLY FLOW WILL
WORK IN TANDEM WITH INCREASING CLOUDINESS TO KEEP MINS QUITE
ELEVATED TONIGHT...ALTHOUGH A SHARP GRADIENT WILL EXIST IN THE FAR
NW DUE TO THE PROXIMITY OF THE FRONT. MINS WILL RANGE FROM NEAR 60
AT THE COAST...TO AS LOW AS 50 NEAR BENNETTSVILLE WHERE THE COLD
FRONT WILL BE AT THE END OF THE PERIOD. ALTHOUGH ADVECTION SHOWERS
WILL WIND DOWN DURING THE NIGHT...HAVE RAMPED POP BACK UP AGAIN
TOWARDS TUESDAY MORNING FROM WEST TO EAST ASSOCIATED WITH THE COLD
FRONT. BEST DYNAMICS DO GET SHEARED OFF TO THE NORTH IN CONJUNCTION
WITH WEAKENING 300MB DIFFLUENCE...BUT ENOUGH MOIST ADVECTION /LOW
LEVEL THETA-E RIDGING/ AHEAD OF THIS BOUNDARY WILL SUPPORT SCATTERED
SHOWERS ALONG AND JUST BEHIND THE FRONT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 2:00 PM MONDAY...COLD FRONT MOVES ACROSS THE FORECAST AREA
TUESDAY MORNING AND OFFSHORE RIGHT AROUND OR SHORTLY AFTER
DAYBREAK. PRETTY DECENT SURGE OF COLD AND MOIST AIR BEHIND FRONT
COMBINED WITH A WEDGE-TYPE SETUP ON WEDNESDAY MAKES FOR A DREARY
SHORT TERM. BEST CHANCE AT PRECIPITATION WILL BE EARLY ON TUESDAY
ACCOMPANYING AND IMMEDIATELY FOLLOWING FRONT. BEST UPPER SUPPORT
WILL PASS WELL TO THE NORTH AND WEST HOWEVER...SO WILL KEEP QPF
ON THE MODEST SIDE WITH HIGHEST VALUES WELL INLAND. MOST PLACES
WILL LIKELY SEE PRECIPITATION ONLY ON THE ORDER OF HUNDREDTHS OF
AN INCH THROUGH THE SHORT TERM...MAYBE A TENTH OF AN INCH OR SO
FOR OUR FAR INLAND COUNTIES. WEDGE TYPE PATTERN SETS UP ON
WEDNESDAY...LEADING TO A CLOUDY AND COOL DAY WITH PATCHY LIGHT
RAIN OR DRIZZLE POSSIBLE.
TEMPERATURES WILL RUN BELOW NORMAL BOTH DAYS. THE TRICKIER DAY TO
FORECAST TEMPERATURES WILL BE TUESDAY AS THIS WILL DEPEND ON THE
TIMING OF THE COLD SURGE POST-FROPA. EXPECTING A WIDE RANGE OF
TEMPERATURES...WITH MID 60S ALONG THE COAST AND UPPER 50S INLAND
FOR DAYTIME HIGHS. MID TO UPPER 50S FOR DAYTIME TEMPERATURES WILL
BE THE LIKELY SCENARIO FOR WEDNESDAY. OVERNIGHT LOWS BOTH DAYS
WILL BE IN THE LOWER TO MID 40S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...HIGH PRESSURE CONTINUES TO RIDGE DOWN FROM THE
NORTHEAST STATES IN A WEDGE LIKE PATTERN THROUGH EARLY THURS. A
MINOR PERTURBATION RIDES BY THURS AFTN IN AN OTHERWISE ZONAL MID
LEVEL FLOW. LOOKS LIKE THIS MAY INITIATE SOME PCP FARTHER TO THE
NORTH AND WEST OF LOCAL CWA WITH MORE IN THE WAY OF CLOUDS HANGING
OVER COASTAL CAROLINAS. SOME SUBSIDENCE BEHIND THIS SHORTWAVE WILL
PROVIDE SOME ENHANCED MID LEVEL DRYING AND MAY HELP TO PRODUCE SOME
BREAKS IN CLOUDS LATE THURS BUT DOES NOT LOOK LIKE WE WILL SCOUR OUT
THE LOW LEVEL MOISTURE STUCK UNDER INVERSION.
BY FRIDAY...MID TO UPPER TROUGH DIGS DOWN INTO THE GULF COAST AS
WAVE OF LOW PRESSURE DEVELOPS ALONG THE CAROLINA COAST. THIS LOW
PRESSURE WILL MOVE SLOWLY UP ALONG THE EASTERN SEA BOARD THROUGH THE
WEEKEND AND MAY DEEPEN AS H5 TROUGH SWINGS THROUGH. THIS WILL
INCREASE THE CHC OF PCP ESPECIALLY ALONG THE COAST FRI NIGHT THROUGH
MUCH OF THE WEEKEND. AS LOW LIFTS OFF TO THE NORTHEAST LATE SUNDAY
THROUGH MONDAY SHOULD SEE DEEPER LAYER NW FLOW SET UP WITH DRIER AIR
MAKING ITS WAY INTO THE AREA. MAY SEE SOME WRAP AROUND CLOUDS AND
PCP THROUGH MONDAY BUT OVERALL LOOKS LIKE AREA WILL FINALLY DRY OUT
BY LATE MONDAY INTO TUESDAY.
MAY NOT SEE MUCH OF THE SUN AS MOISTURE REMAINS LOCKED IN AT LOW
LEVELS. THE SHALLOW COOL AIR AND NORTHERLY WINDS COMBINED WITH
CLOUDS AND SOME PCP AT TIMES WILL KEEP TEMPS DOWN BELOW NORMAL
THROUGH THE EXTENDED PERIOD. THE CLOUDS AND MOISTURE WILL HOLD
OVERNIGHT LOWS AT OR ABOVE NORMAL AND DAYTIME HIGHS WELL BELOW
NORMAL. IT WILL BE TOUGH TO REACH 60 DEGREES DURING THE DAY ACROSS
MOST OF CWA THROUGH AT LEAST EARLY NEXT WEEK. TEMPS OVERNIGHT WILL
DROP INTO THE 40S.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...COLD FRONT APPROACHING FROM THE WEST TONIGHT. AHEAD OF
THE FRONT...LOOK FOR SOUTHEAST FLOW WITH SOME FOG POSSIBLE AFTER
MIDNIGHT. LOW LEVEL MOISTURE IS SOLID...BUT A DENSE CIRRUS OVERCAST
COULD HAMPER FOG FORMATION. SOME STRATUS IS POSSIBLE WITH THE HIGH
DEWPOINTS PASSING OVER THE COOL WATER. POST FRONTAL WEATHER...LOOK
FOR A FAIRLY RAPID WIND SHIFT TO THE NORTH...WITH LOWERING CEILINGS
AND SCATTERED LIGHT PRECIP. CEILINGS WILL LIKELY LOWER TO IFR AROUND
OR JUST AFTER DAYBREAK AT THE WESTERN TERMINALS WITH WIDESPREAD IFR
POSSIBLE BY AFTERNOON AT ALL TERMINALS. CONTINUED NORTH NORTHEAST FLOW
THROUGH THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR POST FRONTAL STRATUS WED
AND THURS...POSSIBLY INTO FRI AS WELL. ANOTHER CHANCE OF SHOWERS FRI
NIGHT THROUGH SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6:00 PM FRIDAY...LARGE SURFACE HIGH CONTINUES TO PULL OFF TO
THE NORTHEAST...LEAVING 10-15 KT E/SE WINDS OVER THE WATERS ON
RETURN FLOW. THESE WINDS ARE EXPECTED TO CONTINUE WHILE VEERING MORE
TO THE SOUTH TONIGHT AHEAD OF A STRONG COLD FRONT APPROACHING FROM
THE WEST...ALTHOUGH FROPA WILL OCCUR WELL AFTER THE NEAR TERM
PERIOD. SEAS CURRENTLY 2-4 FT IN THE COASTAL WATERS...WITH 5 FTERS
NOW SHOWING UP AT FRYING PAN SHOALS...DOMINATED BY A 6-7 SEC SE WIND
WAVE. WINDS WILL DROP OFF ONLY SLIGHTLY TONIGHT...WHICH WILL ALLOW
WAVE PERIODS TO INCREASE AS LONG EASTERLY FETCH FAVORS A SLIGHTLY
LONGER SWELL PERIOD...WITH SEAS REMAINING 2-4 FT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 2:00 PM MONDAY...A STRONG COLD FRONT WILL MOVE ACROSS THE
WATERS EARLY ON TUESDAY...SHIFTING WINDS TO THE NORTH BY NOON ON
TUESDAY AND THEN NE TUESDAY EVENING. WINDS WILL GRADUALLY PICK UP
TO 15 TO 20 KTS TUESDAY NIGHT AS A COLD SURGE MOVES ACROSS THE
WATERS. WINDS WILL STAY IN THAT RANGE FOR THE REMAINDER OF THE
SHORT TERM. SEAS WILL BUILD IN TURN...REACHING SMALL CRAFT
CRITERIA TUESDAY NIGHT. IT IS LIKELY THAT WE WILL BE ISSUING A
SMALL CRAFT ADVISORY VALID BEGINNING ON TUESDAY NIGHT. EXPECT BOTH
DAYS WILL BE COOL AND CLOUDY WITH PERIODS OF RAIN OR DRIZZLE.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...SFC HIGH PRESSURE CONTINUES TO RIDGE DOWN FROM
THE NORTH ON THURS WITH CONTINUED NE FLOW. A WAVE OF LOW PRESSURE
WILL DEVELOP ALONG THE CAROLINA COAST LATE FRI AND THIS WILL ACT TO
ENHANCE THE NE GRADIENT FLOW AS IT RIDES UP THE EASTERN SEA BOARD
THROUGH THE WEEKEND. SEAS WILL ACTUALLY TAKE A DIP DOWNWARD THROUGH
THURS IN DIMINISHING NE WINDS AROUND 15 KTS...BUT THIS WILL BE SHORT
LIVED. SEAS WILL BE DOWN TO 2 TO 4 FT BY THURS EVENING. EXPECT A
SHARP RISE IN SEAS IN TIGHTENED GRADIENT FLOW BRINGING NE WINDS UP
AS HIGH AS 25 TO 30 KTS IN OUTER WATERS FRI NIGHT THROUGH SATURDAY.
THEREFORE SEAS MAY DROP BELOW SCA THRESHOLDS THROUGH THURS INTO
EARLY FRI ONLY TO INCREASE AGAIN BY FRI NIGHT. NEWEST WNA MODEL RUNS
SHOW SEAS UP CLOSE TO 10 FT OUT NEAR FRYING PAN SHOALS BY SAT NIGHT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...REK
LONG TERM...RGZ
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
315 PM EST MON NOV 12 2012
.SYNOPSIS...
UNSEASONABLE WARMTH WILL PERSIST TODAY EVEN THOUGH CLOUDS WILL
BE ON THE INCREASE. A COLD FRONT MOVES ACROSS THE EASTERN
CAROLINAS ON TUESDAY...BRINGING AN EXTENDED PERIOD OF CLOUDY AND
COOL WEATHER THAT MAY LAST INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2:00 PM MONDAY...THE CAROLINAS REMAIN SANDWICHED BETWEEN A
DEPARTING LARGE HIGH PRESSURE OFF TO THE NORTHEAST...AND AN
ADVANCING COLD FRONT FROM THE WEST. THIS IS CREATING WARM AND MOIST
ADVECTION INTO THE ILM CWA...WITH ISOLATED ADVECTION SHOWERS AND
TEMPS RISING WELL INTO THE 70S TO NEAR 80 DEGREES THIS AFTN.
SHOWERS DEVELOPING OVER THE MOIST ATLANTIC ON THE E/SE RETURN FLOW
WILL GRADUALLY DISSIPATE THROUGH THIS EVE AS WINDS BECOME MORE
SOUTHERLY...MEANING LESS OF A FETCH ACROSS THE OCEAN. WILL CONTINUE
SCHC POP...MAINLY ALONG THE COAST...THROUGH NIGHTFALL BEFORE
DECREASING INSTABILITY AND A MORE SOUTHERLY WIND TRAJECTORY WILL
HELP SQUELCH MOST SHOWERS. THIS IS SHOWN WELL BY THE HRRR AND ARW
THIS AFTN. BEST CHANCE FOR SHOWERS THROUGH TONIGHT WILL BE ALONG THE
CAPE FEAR COAST...BUT EVEN THESE WILL CARRY VERY LITTLE QPF.
SOUTHERLY WINDS WILL REMAIN ELEVATED TONIGHT AS GRADIENT TIGHTENS
AHEAD OF THE APPROACHING COLD FRONT. THIS WARM SOUTHERLY FLOW WILL
WORK IN TANDEM WITH INCREASING CLOUDINESS TO KEEP MINS QUITE
ELEVATED TONIGHT...ALTHOUGH A SHARP GRADIENT WILL EXIST IN THE FAR
NW DUE TO THE PROXIMITY OF THE FRONT. MINS WILL RANGE FROM NEAR 60
AT THE COAST...TO AS LOW AS 50 NEAR BENNETTSVILLE WHERE THE COLD
FRONT WILL BE AT THE END OF THE PERIOD. ALTHOUGH ADVECTION SHOWERS
WILL WIND DOWN DURING THE NIGHT...HAVE RAMPED POP BACK UP AGAIN
TOWARDS TUESDAY MORNING FROM WEST TO EAST ASSOCIATED WITH THE COLD
FRONT. BEST DYNAMICS DO GET SHEARED OFF TO THE NORTH IN CONJUNCTION
WITH WEAKENING 300MB DIFFLUENCE...BUT ENOUGH MOIST ADVECTION /LOW
LEVEL THETA-E RIDGING/ AHEAD OF THIS BOUNDARY WILL SUPPORT SCATTERED
SHOWERS ALONG AND JUST BEHIND THE FRONT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 2:00 PM MONDAY...COLD FRONT MOVES ACROSS THE FORECAST AREA
TUESDAY MORNING AND OFFSHORE RIGHT AROUND OR SHORTLY AFTER
DAYBREAK. PRETTY DECENT SURGE OF COLD AND MOIST AIR BEHIND FRONT
COMBINED WITH A WEDGE-TYPE SETUP ON WEDNESDAY MAKES FOR A DREARY
SHORT TERM. BEST CHANCE AT PRECIPITATION WILL BE EARLY ON TUESDAY
ACCOMPANYING AND IMMEDIATELY FOLLOWING FRONT. BEST UPPER SUPPORT
WILL PASS WELL TO THE NORTH AND WEST HOWEVER...SO WILL KEEP QPF
ON THE MODEST SIDE WITH HIGHEST VALUES WELL INLAND. MOST PLACES
WILL LIKELY SEE PRECIPITATION ONLY ON THE ORDER OF HUNDREDTHS OF
AN INCH THROUGH THE SHORT TERM...MAYBE A TENTH OF AN INCH OR SO
FOR OUR FAR INLAND COUNTIES. WEDGE TYPE PATTERN SETS UP ON
WEDNESDAY...LEADING TO A CLOUDY AND COOL DAY WITH PATCHY LIGHT
RAIN OR DRIZZLE POSSIBLE.
TEMPERATURES WILL RUN BELOW NORMAL BOTH DAYS. THE TRICKIER DAY TO
FORECAST TEMPERATURES WILL BE TUESDAY AS THIS WILL DEPEND ON THE
TIMING OF THE COLD SURGE POST-FROPA. EXPECTING A WIDE RANGE OF
TEMPERATURES...WITH MID 60S ALONG THE COAST AND UPPER 50S INLAND
FOR DAYTIME HIGHS. MID TO UPPER 50S FOR DAYTIME TEMPERATURES WILL
BE THE LIKELY SCENARIO FOR WEDNESDAY. OVERNIGHT LOWS BOTH DAYS
WILL BE IN THE LOWER TO MID 40S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...HIGH PRESSURE CONTINUES TO RIDGE DOWN FROM THE
NORTHEAST STATES IN A WEDGE LIKE PATTERN THROUGH EARLY THURS. A
MINOR PERTURBATION RIDES BY THURS AFTN IN AN OTHERWISE ZONAL MID
LEVEL FLOW. LOOKS LIKE THIS MAY INITIATE SOME PCP FARTHER TO THE
NORTH AND WEST OF LOCAL CWA WITH MORE IN THE WAY OF CLOUDS HANGING
OVER COASTAL CAROLINAS. SOME SUBSIDENCE BEHIND THIS SHORTWAVE WILL
PROVIDE SOME ENHANCED MID LEVEL DRYING AND MAY HELP TO PRODUCE SOME
BREAKS IN CLOUDS LATE THURS BUT DOES NOT LOOK LIKE WE WILL SCOUR OUT
THE LOW LEVEL MOISTURE STUCK UNDER INVERSION.
BY FRIDAY...MID TO UPPER TROUGH DIGS DOWN INTO THE GULF COAST AS
WAVE OF LOW PRESSURE DEVELOPS ALONG THE CAROLINA COAST. THIS LOW
PRESSURE WILL MOVE SLOWLY UP ALONG THE EASTERN SEA BOARD THROUGH THE
WEEKEND AND MAY DEEPEN AS H5 TROUGH SWINGS THROUGH. THIS WILL
INCREASE THE CHC OF PCP ESPECIALLY ALONG THE COAST FRI NIGHT THROUGH
MUCH OF THE WEEKEND. AS LOW LIFTS OFF TO THE NORTHEAST LATE SUNDAY
THROUGH MONDAY SHOULD SEE DEEPER LAYER NW FLOW SET UP WITH DRIER AIR
MAKING ITS WAY INTO THE AREA. MAY SEE SOME WRAP AROUND CLOUDS AND
PCP THROUGH MONDAY BUT OVERALL LOOKS LIKE AREA WILL FINALLY DRY OUT
BY LATE MONDAY INTO TUESDAY.
MAY NOT SEE MUCH OF THE SUN AS MOISTURE REMAINS LOCKED IN AT LOW
LEVELS. THE SHALLOW COOL AIR AND NORTHERLY WINDS COMBINED WITH
CLOUDS AND SOME PCP AT TIMES WILL KEEP TEMPS DOWN BELOW NORMAL
THROUGH THE EXTENDED PERIOD. THE CLOUDS AND MOISTURE WILL HOLD
OVERNIGHT LOWS AT OR ABOVE NORMAL AND DAYTIME HIGHS WELL BELOW
NORMAL. IT WILL BE TOUGH TO REACH 60 DEGREES DURING THE DAY ACROSS
MOST OF CWA THROUGH AT LEAST EARLY NEXT WEEK. TEMPS OVERNIGHT WILL
DROP INTO THE 40S.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...VFR ACROSS THE CWA WITH SCT LOW/MID LEVEL CLOUDS AND
SOUTHEAST WINDS AROUND 10 KNOTS. VFR CONDITIONS SHOULD PREVAIL
THROUGH THE EVENING HOURS AS CLOUD COVER WILL INCREASE AHEAD OF AN
APPROACHING COLD FRONT. SOME ISOLATED SHOWERS EMBEDDED IN THE
ONSHORE FLOW CONTINUE TO MOVE INLAND...BUT SHOWERS ARE SO BRIEF AND
LIMITED IN COVERAGE THAT THEY ARE NOT MENTIONED IN THE TAFS. WITH
DEWPOINTS AROUND 60 DEGREES...MVFR VSBYS AND REDUCED CIGS ARE
POSSIBLE AGAIN IN THE EARLY MORNING HOURS. THE COLD FRONT SHOULD
ARRIVE AT THE INLAND TERMS AROUND 12Z...AND THEN THE COASTAL SITES A
COUPLE HOURS LATER. GFS AND NAM INDICATE THE BEST RAIN CHANCES WILL
BE INLAND...SO INCLUDED -SHRA FOR KLBT/KFLO AND VCSH ALONG THE
COAST. BEHIND THE FRONT...MVFR CIGS LIKELY WITH IFR CIGS POSSIBLE.
EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR POST FRONTAL STRATUS WED
AND THURS...POSSIBLY INTO FRI AS WELL. ANOTHER CHANCE OF SHOWERS
FRI NIGHT INTO SAT...MAINLY ALONG THE COAST.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2:00 PM FRIDAY...LARGE SURFACE HIGH CONTINUES TO PULL OFF TO
THE NORTHEAST...LEAVING 10-15 KT E/SE WINDS OVER THE WATERS ON
RETURN FLOW. THESE WINDS ARE EXPECTED TO CONTINUE WHILE VEERING MORE
TO THE SOUTH TONIGHT AHEAD OF A STRONG COLD FRONT APPROACHING FROM
THE WEST...ALTHOUGH FROPA WILL OCCUR WELL AFTER THE NEAR TERM
PERIOD. SEAS CURRENTLY 2-4 FT IN THE COASTAL WATERS...WITH 5 FTERS
NOW SHOWING UP AT FRYING PAN SHOALS...DOMINATED BY A 6-7 SEC SE WIND
WAVE. WINDS WILL DROP OFF ONLY SLIGHTLY TONIGHT...WHICH WILL ALLOW
WAVE PERIODS TO INCREASE AS LONG EASTERLY FETCH FAVORS A SLIGHTLY
LONGER SWELL PERIOD...WITH SEAS REMAINING 2-4 FT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 2:00 PM MONDAY...A STRONG COLD FRONT WILL MOVE ACROSS THE
WATERS EARLY ON TUESDAY...SHIFTING WINDS TO THE NORTH BY NOON ON
TUESDAY AND THEN NE TUESDAY EVENING. WINDS WILL GRADUALLY PICK UP
TO 15 TO 20 KTS TUESDAY NIGHT AS A COLD SURGE MOVES ACROSS THE
WATERS. WINDS WILL STAY IN THAT RANGE FOR THE REMAINDER OF THE
SHORT TERM. SEAS WILL BUILD IN TURN...REACHING SMALL CRAFT
CRITERIA TUESDAY NIGHT. IT IS LIKELY THAT WE WILL BE ISSUING A
SMALL CRAFT ADVISORY VALID BEGINNING ON TUESDAY NIGHT. EXPECT BOTH
DAYS WILL BE COOL AND CLOUDY WITH PERIODS OF RAIN OR DRIZZLE.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...SFC HIGH PRESSURE CONTINUES TO RIDGE DOWN FROM
THE NORTH ON THURS WITH CONTINUED NE FLOW. A WAVE OF LOW PRESSURE
WILL DEVELOP ALONG THE CAROLINA COAST LATE FRI AND THIS WILL ACT TO
ENHANCE THE NE GRADIENT FLOW AS IT RIDES UP THE EASTERN SEA BOARD
THROUGH THE WEEKEND. SEAS WILL ACTUALLY TAKE A DIP DOWNWARD THROUGH
THURS IN DIMINISHING NE WINDS AROUND 15 KTS...BUT THIS WILL BE SHORT
LIVED. SEAS WILL BE DOWN TO 2 TO 4 FT BY THURS EVENING. EXPECT A
SHARP RISE IN SEAS IN TIGHTENED GRADIENT FLOW BRINGING NE WINDS UP
AS HIGH AS 25 TO 30 KTS IN OUTER WATERS FRI NIGHT THROUGH SATURDAY.
THEREFORE SEAS MAY DROP BELOW SCA THRESHOLDS THROUGH THURS INTO
EARLY FRI ONLY TO INCREASE AGAIN BY FRI NIGHT. NEWEST WNA MODEL RUNS
SHOW SEAS UP CLOSE TO 10 FT OUT NEAR FRYING PAN SHOALS BY SAT NIGHT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...REK
LONG TERM...RGZ
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
216 PM EST MON NOV 12 2012
.SYNOPSIS...
UNSEASONABLE WARMTH WILL PERSIST TODAY EVEN THOUGH CLOUDS WILL
BE ON THE INCREASE. A COLD FRONT MOVES ACROSS THE EASTERN
CAROLINAS ON TUESDAY...BRINGING AN EXTENDED PERIOD OF CLOUDY AND
COOL WEATHER THAT MAY LAST INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2:00 PM MONDAY...THE CAROLINAS REMAIN SANDWICHED BETWEEN A
DEPARTING LARGE HIGH PRESSURE OFF TO THE NORTHEAST...AND AN
ADVANCING COLD FRONT FROM THE WEST. THIS IS CREATING WARM AND MOIST
ADVECTION INTO THE ILM CWA...WITH ISOLATED ADVECTION SHOWERS AND
TEMPS RISING WELL INTO THE 70S TO NEAR 80 DEGREES THIS AFTN.
SHOWERS DEVELOPING OVER THE MOIST ATLANTIC ON THE E/SE RETURN FLOW
WILL GRADUALLY DISSIPATE THROUGH THIS EVE AS WINDS BECOME MORE
SOUTHERLY...MEANING LESS OF A FETCH ACROSS THE OCEAN. WILL CONTINUE
SCHC POP...MAINLY ALONG THE COAST...THROUGH NIGHTFALL BEFORE
DECREASING INSTABILITY AND A MORE SOUTHERLY WIND TRAJECTORY WILL
HELP SQUELCH MOST SHOWERS. THIS IS SHOWN WELL BY THE HRRR AND ARW
THIS AFTN. BEST CHANCE FOR SHOWERS THROUGH TONIGHT WILL BE ALONG THE
CAPE FEAR COAST...BUT EVEN THESE WILL CARRY VERY LITTLE QPF.
SOUTHERLY WINDS WILL REMAIN ELEVATED TONIGHT AS GRADIENT TIGHTENS
AHEAD OF THE APPROACHING COLD FRONT. THIS WARM SOUTHERLY FLOW WILL
WORK IN TANDEM WITH INCREASING CLOUDINESS TO KEEP MINS QUITE
ELEVATED TONIGHT...ALTHOUGH A SHARP GRADIENT WILL EXIST IN THE FAR
NW DUE TO THE PROXIMITY OF THE FRONT. MINS WILL RANGE FROM NEAR 60
AT THE COAST...TO AS LOW AS 50 NEAR BENNETTSVILLE WHERE THE COLD
FRONT WILL BE AT THE END OF THE PERIOD. ALTHOUGH ADVECTION SHOWERS
WILL WIND DOWN DURING THE NIGHT...HAVE RAMPED POP BACK UP AGAIN
TOWARDS TUESDAY MORNING FROM WEST TO EAST ASSOCIATED WITH THE COLD
FRONT. BEST DYNAMICS DO GET SHEARED OFF TO THE NORTH IN CONJUNCTION
WITH WEAKENING 300MB DIFFLUENCE...BUT ENOUGH MOIST ADVECTION /LOW
LEVEL THETA-E RIDGING/ AHEAD OF THIS BOUNDARY WILL SUPPORT SCATTERED
SHOWERS ALONG AND JUST BEHIND THE FRONT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 2:00 PM MONDAY...COLD FRONT MOVES ACROSS THE FORECAST AREA
TUESDAY MORNING AND OFFSHORE RIGHT AROUND OR SHORTLY AFTER
DAYBREAK. PRETTY DECENT SURGE OF COLD AND MOIST AIR BEHIND FRONT
COMBINED WITH A WEDGE-TYPE SETUP ON WEDNESDAY MAKES FOR A DREARY
SHORT TERM. BEST CHANCE AT PRECIPITATION WILL BE EARLY ON TUESDAY
ACCOMPANYING AND IMMEDIATELY FOLLOWING FRONT. BEST UPPER SUPPORT
WILL PASS WELL TO THE NORTH AND WEST HOWEVER...SO WILL KEEP QPF
ON THE MODEST SIDE WITH HIGHEST VALUES WELL INLAND. MOST PLACES
WILL LIKELY SEE PRECIPITATION ONLY ON THE ORDER OF HUNDREDTHS OF
AN INCH THROUGH THE SHORT TERM...MAYBE A TENTH OF AN INCH OR SO
FOR OUR FAR INLAND COUNTIES. WEDGE TYPE PATTERN SETS UP ON
WEDNESDAY...LEADING TO A CLOUDY AND COOL DAY WITH PATCHY LIGHT
RAIN OR DRIZZLE POSSIBLE.
TEMPERATURES WILL RUN BELOW NORMAL BOTH DAYS. THE TRICKIER DAY TO
FORECAST TEMPERATURES WILL BE TUESDAY AS THIS WILL DEPEND ON THE
TIMING OF THE COLD SURGE POST-FROPA. EXPECTING A WIDE RANGE OF
TEMPERATURES...WITH MID 60S ALONG THE COAST AND UPPER 50S INLAND
FOR DAYTIME HIGHS. MID TO UPPER 50S FOR DAYTIME TEMPERATURES WILL
BE THE LIKELY SCENARIO FOR WEDNESDAY. OVERNIGHT LOWS BOTH DAYS
WILL BE IN THE LOWER TO MID 40S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 AM MONDAY...LOOKS LIKE THERE MAY END UP BEING VERY LITTLE
DAY-TO-DAY VARIATION OF HIGH TEMPS THROUGH THE PERIOD-MORE TYPICAL
OF THE WARM SEASON. HIGH PRESSURE WEDGE BEING RE-ENFORCED EARLY IN
THE PERIOD. BY SATURDAY A TROUGH SPLITS OFF FROM THE NORTHERN
BRANCH AND DECELERATES ACROSS THE CAROLINAS. FRONTAL BOUNDARY FROM
THE SHORT TERM STILL LURKING OFFSHORE AND PRESSURE PROGGED TO
START FALLING ALONG THE BOUNDARY AS MID LEVEL ASCENT OVERSPREADS.
SOME MOISTURE MAY BE FLUNG BACK TOWARDS THE COAST OVER THE WEEKEND
BUT MODEL CONSENSUS HAS BEEN PRETTY GOOD THAT MOST OF THE RAIN
REMAINS OFFSHORE. COASTAL LOCALES WILL BE ON THE FRINGE...ESP NC
COAST...WHERE SOME RAIN CHANCES STILL SEEM WARRANTED.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...VFR ACROSS THE CWA WITH SCT LOW/MID LEVEL CLOUDS AND
SOUTHEAST WINDS AROUND 10 KNOTS. VFR CONDITIONS SHOULD PREVAIL
THROUGH THE EVENING HOURS AS CLOUD COVER WILL INCREASE AHEAD OF AN
APPROACHING COLD FRONT. SOME ISOLATED SHOWERS EMBEDDED IN THE
ONSHORE FLOW CONTINUE TO MOVE INLAND...BUT SHOWERS ARE SO BRIEF AND
LIMITED IN COVERAGE THAT THEY ARE NOT MENTIONED IN THE TAFS. WITH
DEWPOINTS AROUND 60 DEGREES...MVFR VSBYS AND REDUCED CIGS ARE
POSSIBLE AGAIN IN THE EARLY MORNING HOURS. THE COLD FRONT SHOULD
ARRIVE AT THE INLAND TERMS AROUND 12Z...AND THEN THE COASTAL SITES A
COUPLE HOURS LATER. GFS AND NAM INDICATE THE BEST RAIN CHANCES WILL
BE INLAND...SO INCLUDED -SHRA FOR KLBT/KFLO AND VCSH ALONG THE
COAST. BEHIND THE FRONT...MVFR CIGS LIKELY WITH IFR CIGS POSSIBLE.
EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR POST FRONTAL STRATUS WED
AND THURS...POSSIBLY INTO FRI AS WELL. ANOTHER CHANCE OF SHOWERS
FRI NIGHT INTO SAT...MAINLY ALONG THE COAST.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2:00 PM FRIDAY...LARGE SURFACE HIGH CONTINUES TO PULL OFF TO
THE NORTHEAST...LEAVING 10-15 KT E/SE WINDS OVER THE WATERS ON
RETURN FLOW. THESE WINDS ARE EXPECTED TO CONTINUE WHILE VEERING MORE
TO THE SOUTH TONIGHT AHEAD OF A STRONG COLD FRONT APPROACHING FROM
THE WEST...ALTHOUGH FROPA WILL OCCUR WELL AFTER THE NEAR TERM
PERIOD. SEAS CURRENTLY 2-4 FT IN THE COASTAL WATERS...WITH 5 FTERS
NOW SHOWING UP AT FRYING PAN SHOALS...DOMINATED BY A 6-7 SEC SE WIND
WAVE. WINDS WILL DROP OFF ONLY SLIGHTLY TONIGHT...WHICH WILL ALLOW
WAVE PERIODS TO INCREASE AS LONG EASTERLY FETCH FAVORS A SLIGHTLY
LONGER SWELL PERIOD...WITH SEAS REMAINING 2-4 FT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 2:00 PM MONDAY...A STRONG COLD FRONT WILL MOVE ACROSS THE
WATERS EARLY ON TUESDAY...SHIFTING WINDS TO THE NORTH BY NOON ON
TUESDAY AND THEN NE TUESDAY EVENING. WINDS WILL GRADUALLY PICK UP
TO 15 TO 20 KTS TUESDAY NIGHT AS A COLD SURGE MOVES ACROSS THE
WATERS. WINDS WILL STAY IN THAT RANGE FOR THE REMAINDER OF THE
SHORT TERM. SEAS WILL BUILD IN TURN...REACHING SMALL CRAFT
CRITERIA TUESDAY NIGHT. IT IS LIKELY THAT WE WILL BE ISSUING A
SMALL CRAFT ADVISORY VALID BEGINNING ON TUESDAY NIGHT. EXPECT BOTH
DAYS WILL BE COOL AND CLOUDY WITH PERIODS OF RAIN OR DRIZZLE.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...A PROLONGED PERIOD OF MODERATELY STRONG NE
GRADIENT WIND REGIME CONTINUES. AFTER POSSIBLY A BRIEF DOWNWARD
TREND IN WINDS AND SEAS ON THURSDAY THE GRADIENT WILL BEGIN TO
TIGHTEN ON FRIDAY IN RESPONSE TO AN APPROACHING UPPER WAVE. ASCENT
ASSOCIATED WITH THIS TROUGH WILL CAUSE PRESSURE TO BEGIN FALLING
ALONG THE FRONTAL BOUNDARY SITTING WELL OFFSHORE WHILE HIGH PRESSURE
REMAINS ENTRENCHED OVER THE LANDMASS. THE COASTAL WATERS WILL THEN
BE FOUND IN BETWEEN IN THE BELT OF STRENGTHENING WINDS THAT WILL
LIKELY LAST INTO THE WEEKEND. TOO EARLY TO TELL THIS FAR OUT WHICH
ZONES WILL HAVE SCEC VS SCA BUT HEADLINES OF SOME SORT DO SEEM
LIKELY FOR MOST AREAS THROUGH THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...REK
AVIATION...BJR
MARINE...REK
AREA FORECAST DISCUSSION
NWS RALEIGH NC
110 PM EST MON NOV 12 2012
.SYNOPSIS...
A COLD FRONT MOVES ACROSS THE REGION TONIGHT AND EARLY TUESDAY...
REACHING THE CAROLINA COAST TUESDAY AFTERNOON. COOL HIGH PRESSURE
BUILDS INTO THE AREA BEHIND THE FRONT. AN UPPER LEVEL DISTURBANCE
WILL BRING ANOTHER CHANCE OF RAIN TO MUCH OF THE REGION BY THURSDAY.
&&
.NEAR TERM /TODAY/...
AS OF 945 AM MONDAY...
GOOD LOW-LEVEL MOISTURE IN AN ATLANTIC FLOW HELPING TO RESULT IN
JUST A FEW SHOWERS...WITH JUST ENOUGH LOW-LEVEL CONVERGENCE AS SHOWN
ON THE LATEST MSAS TO ALLOW FOR A FEW OF THESE SHOWERS TO DEVELOP
AND HAVE RAIN REACH THE GROUND. AREA SOUNDINGS ARE STABLE AND DRY BY
700MB...WITH A CAP THAT REMAINS AROUND 700MB THROUGHOUT THE DAY.
BUFR FORECAST SOUNDINGS AND UPPER-LEVEL MOISTURE ANALYSES SHOW THAT
CENTRAL NORTH CAROLINA ESPECIALLY TOWARD INTERSTATE 95 SHOULD REMAIN
PRETTY DRY IN THE MID-LEVELS THROUGHOUT THE DAY...SUCH THAT DESPITE
GRADUALLY INCREASING PRECIPITABLE WATER VALUES AND LIMITED
DIVERGENCE ALOFT...THE CHANCES FOR ANY MEASURABLE PRECIPITATION
SHOULD REMAIN BELOW SLIGHT CHANCE. FARTHER WEST...THE LATEST NAM
ACTUALLY SHOWS A SLIGHT DECREASE IN MID-LEVEL MOISTURE AS 18Z
APPROACHES...FOLLOWED BY RENEWED MOISTENING AGAIN DURING THE
AFTERNOON IN ADVANCE OF THE SURFACE FRONT REACHING THE MOUNTAINS.
850MB CONVERGENCE INCREASES LATE TODAY MAINLY IN THE NORTHWEST
PIEDMONT. THE CURRENT THINKING IS THAT MANY OF THE ISOLATED SHOWERS
IN THE SOUTHWEST PIEDMONT WILL DIMINISH DURING THE REST OF THE
MORNING...WITH A RENEWED CHANCE OF SHOWERS AGAIN MAINLY LATE TOWARD
THE IMMEDIATE TRIAD. MAINTAINED A SLIGHT CHANCE OF A SHOWER AS FAR
EAST AS ABOUT U.S. 1 OR SO AS PREVIOUSLY FORECAST DUE TO
UNCERTAINTY...AND IT SHOULD BE MENTIONED THAT THE LATEST HRRR WRF
HOLDS ONTO A COUPLE OF SHOWERS DURING THE AFTERNOON IN THE MOIST...
SOUTH-SOUTHEAST FLOW WEST OF INTERSTATE 95. GENERALLY LOWERED MAXES
JUST A LITTLE FOR THE AFTERNOON TOWARD THE YADKIN RIVER...AND
INCREASED MAXES A LITTLE IN THE INTERSTATE 95 CORRIDOR DUE TO MORE
SUNSHINE THERE. WHILE CLOUDS MAY THIN AT TIMES WEST...AMOUNT OF
CLOUDS ON VISIBLE SATELLITE IMAGERY AND MOISTURE FORECAST ALOFT WILL
MAKE FOR A MOSTLY CLOUDY DAY. DESPITE 925MB WIND FORECAST OF 20 TO
30KT...HIGHEST NORTHWEST...BELIEVE CLOUD COVER SHOULD TEMPER GUST
POTENTIAL AND HAVE SHOWN IN THE GRIDDED FORECASTS GUSTS AT TIMES
AROUND 20 MPH ON AVERAGE THROUGHOUT CENTRAL NORTH CAROLINA.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
AS OF 300 AM MONDAY...
TONIGHT INTO TUESDAY...MODEL GUIDANCE REMAIN IN GOOD CONSENSUS AS
FAR AS TIMING OF FRONTAL SYSTEM INTO/THROUGH CENTRAL NC OVERNIGHT
TONIGHT INTO TUESDAY MORNING. THIS FRONT WILL BE PROPELLED EASTWARD
AS A PAIR OF S/SW IN THE NORTHERN BRANCH OF UPPER JET CROSSES THE OH
VALLEY INTO THE NORTHERN MID ATLANTIC/SOUTHERN NEW ENGLAND. WHILE
BEST SUPPORT ALOFT WILL REMAIN WELL TO OUR NORTH. ENOUGH CONVERGENCE
IN THE 850-700MB LAYER EXISTS IN A MODERATELY MOIST AIR MASS TO
WARRANT LOW END CATEGORICAL POPS LATE TONIGHT INTO TUESDAY MORNING
ACROSS THE PIEDMONT. STILL EXPECT PRECIP AMOUNTS TO AVERAGE NO MORE
THAN A QUARTER TO A THIRD OF AN INCH...MAINLY ACROSS THE NW COUNTIES
WITH LESSER AMOUNTS PROJECTED FARTHER E-SE AS LIFT WEAKENS WITH
TIME. WHILE ENVIRONMENT WILL EXPERIENCE VERY IMPRESSIVE
SHEAR...BASED ON OVERNIGHT-EARLY MORNING FRONTAL PASSAGE AND LACK OF
LOW LEVEL INSTABILITY AND WEAK/MARGINAL MID LEVEL LAPSE
RATES...THREAT FOR THUNDER APPEARS TOO MINIMAL TO INCLUDE IN
FORECAST AT THIS TIME.
WITH FROPA EXPECTED OVERNIGHT INTO TUESDAY MORNING...LOW LEVEL CAA
WILL COMMENCE BY DAYBREAK IN THE WEST...AND IN THE MID-LATE MORNING
THROUGH AFTERNOON IN THE EAST. WITH OVERCAST SKIES AND SCATTERED TO
NUMEROUS SHOWERS...TEMPS TUESDAY WILL STRUGGLE TO RECOVER BEHIND THE
FRONT. CALENDER DAY HIGH TEMPS TUESDAY FOR MOST LOCALES IN CENTRAL
NC WILL OCCUR BETWEEN MIDNIGHT-6AM WITH STEADY OR FALLING TEMPS
DURING THE DAYLIGHT HOURS. PRIOR TO FROPA...EXPECT MILD EVENING
TEMPS WITH MOST PLACES REMAINING ABOVE 60 DEGREES UNTIL 10
PM-MIDNIGHT.
THREAT FOR SHOWERS WILL GRADUALLY END ACROSS THE COASTAL PLAIN
COUNTIES TUESDAY EVENING THOUGH PASSAGE OF THE 700MB TROUGH NOW NOT
EXPECTED UNTIL CLOSE TO DAYBREAK. THUS MAY SEE A FEW SHOWERS LINGER
SOUTH OF A GOLDSBORO-FAYETTEVILLE LINE PAST MIDNIGHT. EXPECT
DECREASING CLOUDINESS TO OCCUR NW-SE TUESDAY NIGHT. MUCH COOLER
TUESDAY NIGHT COMPARED TO TONIGHT. MIN TEMPS MID-UPPER 30S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...
WEDNESDAY THROUGH THURSDAY NIGHT:
LOW CONFIDENCE IN THE FORECAST SPECIFICS WED NIGHT INTO THU.
SHORTWAVE RIDGING WILL DEVELOP OVER THE CAROLINAS AND MID-ATLANTIC
EARLY WEDNESDAY IN THE WAKE OF A RAPIDLY DEAMPLIFYING UPPER LEVEL
TROUGH PROGRESSING NORTHEAST TO THE CANADIAN MARITIMES...HOWEVER...
BY LATE WED INTO WED NIGHT A SHORTWAVE TROUGH IS PROGGED TO APPROACH
THE CAROLINAS FROM THE WEST. FORECAST UNCERTAINTY IS LOW SINCE THE
AFOREMENTIONED SHORTWAVE ENERGY HAS YET TO MOVE ASHORE THE PAC NW
(THOUGH IT WILL DO SO LATER THIS MORNING)...RESULTING IN A WIDE
VARIETY OF MODEL SOLUTIONS WITH REGARD TO THE TIMING AND AMPLITUDE
OF THE SHORTWAVE TROUGH AS IT APPROACHES FROM THE WEST...AND
POTENTIAL INTERACTION WITH A REMNANT FRONTAL ZONE OVER PORTIONS OF
THE SOUTHEAST (I.E. GA/FL/SC). THE 00Z GFS/NAM INDICATE THE
AFOREMENTIONED SHORTWAVE ENERGY WILL BE MORE PROGRESSIVE...LESS
AMPLIFIED...AND TRACKING ACROSS THE MID-ATLANTIC...RESULTING IN
LITTLE OR NO INTERACTION WITH THE FRONTAL ZONE TO THE SOUTH AND
BASICALLY NO PRECIP OVER CENTRAL NC. HOWEVER...THE 00Z ECMWF SHOWS A
MORE AMPLIFIED SHORTWAVE TRACKING ACROSS THE DEEP SOUTH WED AND
INTERACTING WITH THE STALLED FRONTAL ZONE ALONG THE SOUTHEAST COAST
WED NIGHT THROUGH THU NIGHT...PRODUCING WIDESPREAD CLOUD COVER AND
PRECIPITATION...WITH A GOOD 0.50-1.00" OF QPF. GIVEN THE BETTER
TRACK RECORD OF THE ECMWF...ESPECIALLY IN RECENT WEEKS...FEEL THAT A
TREND TOWARD MORE CLOUD COVER...BETTER CHANCES FOR RAIN...AND COOLER
TEMPERATURES IS REQUIRED FOR THE THU/THU NIGHT TIME-FRAME.
FRIDAY THROUGH SUNDAY:
UNCERTAINTY INCREASES FRIDAY INTO NEXT WEEKEND...WITH LONG RANGE
MODEL GUIDANCE SHOWING A POTENTIAL FOR A CUT-OFF UPPER LEVEL LOW
DEVELOPING OVER THE CAROLINAS/MID-ATLANTIC. GIVEN THE INHERENT
UNCERTAINTY AT THIS RANGE...WHERE KEY FEATURES HAVE YET TO DEVELOP
OR BE SAMPLED...DO NOT FEEL CONFIDENT ENOUGH TO MAKE ANY MAJOR
CHANGES TO TEMPS OR PRECIP CHANCES FRI-SUN...AND THE PREVIOUS
FORECAST WILL BE MODIFIED ONLY BY LOWERING HIGH TEMPS A FEW
DEGREES...INCREASING CLOUD COVER...AND INTRODUCING A SLIGHT CHANCE
(20%) OF RAIN. THE 00Z ECMWF IS THE MORE INTERESTING OF THE LONG
RANGE MODELS...SHOWING A CUT-OFF UPPER LOW SLOWLY TRACKING EASTWARD
FROM THE DEEP SOUTH TO THE SOUTHEAST COAST AND EVENTUALLY OFFSHORE
BETWEEN SAT-TUE...WITH A GOOD 2" OF RAIN OVER CENTRAL NC...WHILE THE
GFS IS WEAKER WITH THIS FEATURE AND FURTHER EAST...CONFINING ANY
RAINFALL TO COASTAL PORTIONS OF THE STATE. -VINCENT
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 110 PM MONDAY...
MOSTLY VFR CONDITIONS WILL CONTINUE DURING THE REST OF THE
AFTERNOON...WITH ISOLATED MVFR CONDITIONS TOWARD KRWI IN ISOLATED
SHOWERS...AND AREAS OF MOSTLY MVFR CONDITIONS TOWARD THE TRIAD UNDER
SCATTERED SHOWERS. PERIODS OF WIND GUSTS TO NEAR 20KT WILL PERSIST
THIS AFTERNOON AHEAD OF A COLD FRONT...THAT WILL MOVE THROUGH MOST
OF THE CENTRAL NORTH CAROLINA AIRPORTS BY 12Z TUESDAY. NUMEROUS
SHOWERS WILL OCCUR IN VICINITY OF THE FRONT...AND EVEN BEHIND THE
FRONT UNTIL DRY AIR MOVES INTO CENTRAL NORTH CAROLINA FROM THE WEST.
WIDESPREAD IFR CONDITIONS AT LEAST IN TERMS OF LOW CLOUDS ARE
EXPECTED FOLLOWING THE FRONTAL PASSAGE...WITH IMPROVEMENT EXPECTED
TOWARD KINT AND KGSO TOWARD THE END OF THE 18Z VALID TAF PERIOD AS
THE DRIER AIR STARTS TO MOVE IN. CONDITIONS ARE EXPECTED TO IMPROVE
TO MVFR AT KRDU AND KFAY JUST AFTER THE 18Z VALID TAF PERIOD...A
LITTLE LATER IN THE AFTERNOON TOWARD KRWI. EXPECT A NORTHERLY WIND
AVERAGING 8 TO 15KT TUESDAY.
BEYOND THE 18Z VALID TAF PERIOD...VFR CONDITIONS SHOULD RETURN TO
ALL OF CENTRAL NORTH CAROLINA DURING TUESDAY EVENING. IT APPEARS
THAT CHANCES ARE INCREASING FOR AT LEAST A PERIOD OF LIGHT RAIN AND
MVFR CONDITIONS WEDNESDAY NIGHT AND THURSDAY AHEAD OF AN UPPER LEVEL
DISTURBANCE AND WEAK SURFACE LOW PRESSURE. MVFR CONDITIONS ARE ALSO
POSSIBLE SATURDAY DEPENDING ON THE LOCATION OF LOW PRESSURE OFF OF
THE CAROLINA COAST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF/WSS
SHORT TERM...WSS
LONG TERM...VINCENT
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
945 AM EST MON NOV 12 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TODAY...THEN CROSS CENTRAL
NORTH CAROLINA TONIGHT AND TUESDAY MORNING. COOL HIGH PRESSURE WILL
BUILD OVER THE AREA FOR THE MIDDLE OF THE WEEK...WITH AN UPPER LEVEL
DISTURBANCE BRINGING THE THREAT OF RAIN TO THE AREA BY THURSDAY.
&&
.NEAR TERM /TODAY/...
AS OF 945 AM MONDAY...
GOOD LOW-LEVEL MOISTURE IN AN ATLANTIC FLOW HELPING TO RESULT IN
JUST A FEW SHOWERS...WITH JUST ENOUGH LOW-LEVEL CONVERGENCE AS SHOWN
ON THE LATEST MSAS TO ALLOW FOR A FEW OF THESE SHOWERS TO DEVELOP
AND HAVE RAIN REACH THE GROUND. AREA SOUNDINGS ARE STABLE AND DRY BY
700MB...WITH A CAP THAT REMAINS AROUND 700MB THROUGHOUT THE DAY.
BUFR FORECAST SOUNDINGS AND UPPER-LEVEL MOISTURE ANALYSES SHOW THAT
CENTRAL NORTH CAROLINA ESPECIALLY TOWARD INTERSTATE 95 SHOULD REMAIN
PRETTY DRY IN THE MID-LEVELS THROUGHOUT THE DAY...SUCH THAT DESPITE
GRADUALLY INCREASING PRECIPITABLE WATER VALUES AND LIMITED
DIVERGENCE ALOFT...THE CHANCES FOR ANY MEASURABLE PRECIPITATION
SHOULD REMAIN BELOW SLIGHT CHANCE. FARTHER WEST...THE LATEST NAM
ACTUALLY SHOWS A SLIGHT DECREASE IN MID-LEVEL MOISTURE AS 18Z
APPROACHES...FOLLOWED BY RENEWED MOISTENING AGAIN DURING THE
AFTERNOON IN ADVANCE OF THE SURFACE FRONT REACHING THE MOUNTAINS.
850MB CONVERGENCE INCREASES LATE TODAY MAINLY IN THE NORTHWEST
PIEDMONT. THE CURRENT THINKING IS THAT MANY OF THE ISOLATED SHOWERS
IN THE SOUTHWEST PIEDMONT WILL DIMINISH DURING THE REST OF THE
MORNING...WITH A RENEWED CHANCE OF SHOWERS AGAIN MAINLY LATE TOWARD
THE IMMEDIATE TRIAD. MAINTAINED A SLIGHT CHANCE OF A SHOWER AS FAR
EAST AS ABOUT U.S. 1 OR SO AS PREVIOUSLY FORECAST DUE TO
UNCERTAINTY...AND IT SHOULD BE MENTIONED THAT THE LATEST HRRR WRF
HOLDS ONTO A COUPLE OF SHOWERS DURING THE AFTERNOON IN THE MOIST...
SOUTH-SOUTHEAST FLOW WEST OF INTERSTATE 95. GENERALLY LOWERED MAXES
JUST A LITTLE FOR THE AFTERNOON TOWARD THE YADKIN RIVER...AND
INCREASED MAXES A LITTLE IN THE INTERSTATE 95 CORRIDOR DUE TO MORE
SUNSHINE THERE. WHILE CLOUDS MAY THIN AT TIMES WEST...AMOUNT OF
CLOUDS ON VISIBLE SATELLITE IMAGERY AND MOISTURE FORECAST ALOFT WILL
MAKE FOR A MOSTLY CLOUDY DAY. DESPITE 925MB WIND FORECAST OF 20 TO
30KT...HIGHEST NORTHWEST...BELIEVE CLOUD COVER SHOULD TEMPER GUST
POTENTIAL AND HAVE SHOWN IN THE GRIDDED FORECASTS GUSTS AT TIMES
AROUND 20 MPH ON AVERAGE THROUGHOUT CENTRAL NORTH CAROLINA.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
AS OF 300 AM MONDAY...
TONIGHT INTO TUESDAY...MODEL GUIDANCE REMAIN IN GOOD CONSENSUS AS
FAR AS TIMING OF FRONTAL SYSTEM INTO/THROUGH CENTRAL NC OVERNIGHT
TONIGHT INTO TUESDAY MORNING. THIS FRONT WILL BE PROPELLED EASTWARD
AS A PAIR OF S/SW IN THE NORTHERN BRANCH OF UPPER JET CROSSES THE OH
VALLEY INTO THE NORTHERN MID ATLANTIC/SOUTHERN NEW ENGLAND. WHILE
BEST SUPPORT ALOFT WILL REMAIN WELL TO OUR NORTH. ENOUGH CONVERGENCE
IN THE 850-700MB LAYER EXISTS IN A MODERATELY MOIST AIR MASS TO
WARRANT LOW END CATEGORICAL POPS LATE TONIGHT INTO TUESDAY MORNING
ACROSS THE PIEDMONT. STILL EXPECT PRECIP AMOUNTS TO AVERAGE NO MORE
THAN A QUARTER TO A THIRD OF AN INCH...MAINLY ACROSS THE NW COUNTIES
WITH LESSER AMOUNTS PROJECTED FARTHER E-SE AS LIFT WEAKENS WITH
TIME. WHILE ENVIRONMENT WILL EXPERIENCE VERY IMPRESSIVE
SHEAR...BASED ON OVERNIGHT-EARLY MORNING FRONTAL PASSAGE AND LACK OF
LOW LEVEL INSTABILITY AND WEAK/MARGINAL MID LEVEL LAPSE
RATES...THREAT FOR THUNDER APPEARS TOO MINIMAL TO INCLUDE IN
FORECAST AT THIS TIME.
WITH FROPA EXPECTED OVERNIGHT INTO TUESDAY MORNING...LOW LEVEL CAA
WILL COMMENCE BY DAYBREAK IN THE WEST...AND IN THE MID-LATE MORNING
THROUGH AFTERNOON IN THE EAST. WITH OVERCAST SKIES AND SCATTERED TO
NUMEROUS SHOWERS...TEMPS TUESDAY WILL STRUGGLE TO RECOVER BEHIND THE
FRONT. CALENDER DAY HIGH TEMPS TUESDAY FOR MOST LOCALES IN CENTRAL
NC WILL OCCUR BETWEEN MIDNIGHT-6AM WITH STEADY OR FALLING TEMPS
DURING THE DAYLIGHT HOURS. PRIOR TO FROPA...EXPECT MILD EVENING
TEMPS WITH MOST PLACES REMAINING ABOVE 60 DEGREES UNTIL 10
PM-MIDNIGHT.
THREAT FOR SHOWERS WILL GRADUALLY END ACROSS THE COASTAL PLAIN
COUNTIES TUESDAY EVENING THOUGH PASSAGE OF THE 700MB TROUGH NOW NOT
EXPECTED UNTIL CLOSE TO DAYBREAK. THUS MAY SEE A FEW SHOWERS LINGER
SOUTH OF A GOLDSBORO-FAYETTEVILLE LINE PAST MIDNIGHT. EXPECT
DECREASING CLOUDINESS TO OCCUR NW-SE TUESDAY NIGHT. MUCH COOLER
TUESDAY NIGHT COMPARED TO TONIGHT. MIN TEMPS MID-UPPER 30S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...
WEDNESDAY THROUGH THURSDAY NIGHT:
LOW CONFIDENCE IN THE FORECAST SPECIFICS WED NIGHT INTO THU.
SHORTWAVE RIDGING WILL DEVELOP OVER THE CAROLINAS AND MID-ATLANTIC
EARLY WEDNESDAY IN THE WAKE OF A RAPIDLY DEAMPLIFYING UPPER LEVEL
TROUGH PROGRESSING NORTHEAST TO THE CANADIAN MARITIMES...HOWEVER...
BY LATE WED INTO WED NIGHT A SHORTWAVE TROUGH IS PROGGED TO APPROACH
THE CAROLINAS FROM THE WEST. FORECAST UNCERTAINTY IS LOW SINCE THE
AFOREMENTIONED SHORTWAVE ENERGY HAS YET TO MOVE ASHORE THE PAC NW
(THOUGH IT WILL DO SO LATER THIS MORNING)...RESULTING IN A WIDE
VARIETY OF MODEL SOLUTIONS WITH REGARD TO THE TIMING AND AMPLITUDE
OF THE SHORTWAVE TROUGH AS IT APPROACHES FROM THE WEST...AND
POTENTIAL INTERACTION WITH A REMNANT FRONTAL ZONE OVER PORTIONS OF
THE SOUTHEAST (I.E. GA/FL/SC). THE 00Z GFS/NAM INDICATE THE
AFOREMENTIONED SHORTWAVE ENERGY WILL BE MORE PROGRESSIVE...LESS
AMPLIFIED...AND TRACKING ACROSS THE MID-ATLANTIC...RESULTING IN
LITTLE OR NO INTERACTION WITH THE FRONTAL ZONE TO THE SOUTH AND
BASICALLY NO PRECIP OVER CENTRAL NC. HOWEVER...THE 00Z ECMWF SHOWS A
MORE AMPLIFIED SHORTWAVE TRACKING ACROSS THE DEEP SOUTH WED AND
INTERACTING WITH THE STALLED FRONTAL ZONE ALONG THE SOUTHEAST COAST
WED NIGHT THROUGH THU NIGHT...PRODUCING WIDESPREAD CLOUD COVER AND
PRECIPITATION...WITH A GOOD 0.50-1.00" OF QPF. GIVEN THE BETTER
TRACK RECORD OF THE ECMWF...ESPECIALLY IN RECENT WEEKS...FEEL THAT A
TREND TOWARD MORE CLOUD COVER...BETTER CHANCES FOR RAIN...AND COOLER
TEMPERATURES IS REQUIRED FOR THE THU/THU NIGHT TIME-FRAME.
FRIDAY THROUGH SUNDAY:
UNCERTAINTY INCREASES FRIDAY INTO NEXT WEEKEND...WITH LONG RANGE
MODEL GUIDANCE SHOWING A POTENTIAL FOR A CUT-OFF UPPER LEVEL LOW
DEVELOPING OVER THE CAROLINAS/MID-ATLANTIC. GIVEN THE INHERENT
UNCERTAINTY AT THIS RANGE...WHERE KEY FEATURES HAVE YET TO DEVELOP
OR BE SAMPLED...DO NOT FEEL CONFIDENT ENOUGH TO MAKE ANY MAJOR
CHANGES TO TEMPS OR PRECIP CHANCES FRI-SUN...AND THE PREVIOUS
FORECAST WILL BE MODIFIED ONLY BY LOWERING HIGH TEMPS A FEW
DEGREES...INCREASING CLOUD COVER...AND INTRODUCING A SLIGHT CHANCE
(20%) OF RAIN. THE 00Z ECMWF IS THE MORE INTERESTING OF THE LONG
RANGE MODELS...SHOWING A CUT-OFF UPPER LOW SLOWLY TRACKING EASTWARD
FROM THE DEEP SOUTH TO THE SOUTHEAST COAST AND EVENTUALLY OFFSHORE
BETWEEN SAT-TUE...WITH A GOOD 2" OF RAIN OVER CENTRAL NC...WHILE THE
GFS IS WEAKER WITH THIS FEATURE AND FURTHER EAST...CONFINING ANY
RAINFALL TO COASTAL PORTIONS OF THE STATE. -VINCENT
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AS OF 945 AM MONDAY...
EXPECT VFR CONDITIONS ACROSS THE REGION THROUGH MOST OF THE DAY...
WITH SPOTTY MVFR CONDITIONS AT TIMES NEAR THE TRIAD IN DECENT
LOW-LEVEL MOISTURE. NEAR SURFACE SLY WINDS WILL INCREASE TO AROUND
10KTS SUSTAINED WITH GUSTS 17-20KTS. THESE WINDS SHOULD SUBSIDE A
LITTLE BY SUNSET. ANY SHOWERS THAT OCCUR THROUGH EARLY AFTERNOON
WILL BE VERY ISOLATED AND MAINLY WEST OF KRDU AND KFAY. SHOWER
THREAT SHOULD INCREASE LATE IN THE DAY IN VICINITY OF THE TRIAD
TERMINALS.
A STRONG COLD FRONT WILL APPROACH FROM THE WEST LATE TODAY AND CROSS
CENTRAL NC TONIGHT INTO EARLY TUESDAY. CURRENTLY EXPECT FROPA IN THE
TRIAD REGION BETWEEN MIDNIGHT AND 3 AM...THE KRDU AND KFAY TERMINALS
BETWEEN 4 AND 7 AM...AND THE KRWI AND GSB VICINITIES BETWEEN 7 AND
10 AM. BULK OF PRECIP AND SUB VFR CEILINGS ASSOCIATED WITH THE FRONT
WILL OCCUR ALONG AND BEHIND THE FRONT IN THE FORM OF SCATTERED TO
NUMEROUS SHOWERS. THESE CONDITIONS EXPECTED TO PERSIST THROUGH MUCH
OF TUESDAY WITH GRADUAL IMPROVEMENT (SHOWERS DIMINISHING AND
CEILINGS LIFTING) OCCURRING FROM THE NW LATE TUESDAY AFTERNOON INTO
TUESDAY EVENING.
IN THE WAKE OF THE FRONT...SURFACE HIGH PRESSURE WILL BUILD INTO
CENTRAL NC FROM THE NNW WEDNESDAY...BRINGING VFR CONDITIONS. RESPITE
FROM ADVERSE AVIATION CONDITIONS EXPECTED TO BE BRIEF AS ANOTHER
LOW PRESSURE SYSTEM MAY AFFECT CENTRAL NC WEDNESDAY NIGHT INTO
THURSDAY CAUSING MVFR CEILINGS ALONG WITH THREAT OF RAIN. BROAD
CYCLONIC FLOW AND ANOTHER AREA OF LOW PRESSURE APPROACHING ON FRIDAY
WILL KEEP A LINGERING RISK FOR MVFR CONDITIONS DURING THE LATE-WEEK
PERIOD.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF/WSS
NEAR TERM...DJF/WSS
SHORT TERM...WSS
LONG TERM...VINCENT
AVIATION...DJF/WSS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
338 PM EST MON NOV 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL BEGIN BUILDING INTO THE AREA FROM THE
SOUTHWEST TONIGHT AND THEN MOVE OVER THE AREA TUESDAY AND
WEDNESDAY. THE HIGH PRESSURE CENTER WILL MOVE NORTHEAST OF THE
AREA...BUT WILL CONTINUE TO RIDGE OVER THE AREA THROUGH THE
SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE COLD FRONT THAT MOVED THROUGH THE AREA TODAY IS MOVING OUT OF
THE FORECAST AREA AS OF 20Z. RAIN WILL CONTINUE ESPECIALLY ACROSS
THE EASTERN HALF OF THE AREA THROUGH THE REMAINDER OF THE
AFTERNOON AND EVENING. MEANWHILE...THERE IS A SHARP CUTOFF TO BOTH
PRECIP AND CLOUDS ACROSS THE WEST WITH SATELLITE SHOWING CLEARING
MOVING INTO NW OH ALREADY THIS AFTERNOON. OBS HAVE SHOWN A MIX OF
RAIN AND SNOW ACROSS WESTERN COUNTIES BUT RAIN ELSEWHERE. MADE
ONLY SMALL ADJUSTMENTS TO POPS THROUGH EARLY TONIGHT WITH THE RAIN
CONTINUING TO PUSH EASTWARD AND DECREASING POPS FROM WEST TO EAST.
WITH THAT MENTION ONLY CHC POPS ACROSS THE WEST FOR EARLY
TONIGHT...THEN DRY AFTER MIDNIGHT.
ONCE THIS AREA OF SHOWERS DEPARTS TO THE EAST THE FOCUS WILL BE ON
LAKE EFFECT SNOW SHOWERS. WITH H850 TEMPS DROPPING DOWN TO -8C OR
SO AND INVERSIONS SHOWN ON BUFKIT SOUNDING STILL A BIT HIGH
EXPECTING LINGERING CLOUDS WITH WEST WINDS ACROSS NE OH AND NW PA
AFTER MIDNIGHT TONIGHT. THINKING THAT WITH THE AMOUNT OF DRIER AIR
BUILDING IN THIS WILL LIMIT LAKE EFFECT SNOW DEVELOPMENT AND WILL
HAVE TO WAIT FOR SOME ADDITIONAL SUPPORT LATE OVERNIGHT.
WATER VAPOR AND MODELS SHOWING SHARPER UPPER TROUGH THAT IS
EXPECTED TO SWING ACROSS THE SOUTHERN GREAT LAKES LATE OVERNIGHT
AND TUESDAY MORNING. EXPECTING THIS TO HELP IN GETTING SOME LAKE
EFFECT SNOW ACROSS NE OH AND NW PA. ELSEWHERE EXPECTING PARTLY
CLOUDY SKIES. USED A BLEND OF MET AND MAV TEMPS WITH HRRR TRENDS
IN THE VERY SHORT TERM ON HOURLY TEMPS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
GUIDANCE POPS NOT INDICATING MUCH WITH LAKE EFFECT SNOW
SHOWERS...BUT WENT WITH AT LEAST HIGH CHC POPS ACROSS NE OH AND NW
PA TUESDAY MORNING. WITH THE WEST FLOW NOT EXPECTING MUCH ACROSS
GREATER CLEVELAND AREA...WITH BEST ACCUMS STRETCHING FROM CENTRAL
ASHTABULA COUNTY INTO INTERIOR ERIE COUNTY. THINKING FURTHER SOUTH
THROUGH CRAWFORD COUNTIES AMOUNTS WILL DIMINISH. BETTER SFC
CONVERGENCE OFF THE LAKE APPEARS TO BE IN THIS AREA ALSO. OVERALL
THOUGH THINKING ACCUMS WILL RANGE AROUND AN INCH OR SO ACROSS
INTERIOR NW PA TO LESS THAN AN INCH BACK INTO FAR NE OH COUNTIES.
BY AFTERNOON THE TROUGH PUSHES TO THE EAST AND DRIER AIR OVERCOMES
THE LAKE EFFECT POTENTIAL. SOME LINGERING CLOUDS AND PERHAPS SOME
FLURRIES POSSIBLE ACROSS HIGHER ELEVATIONS OF NW PA...BUT NOT
EXPECTING ANY FURTHER ACCUMS. FOR THE REMAINDER OF THE AREA HIGH
PRESSURE INFLUENCE WILL HELP ALLOW FOR SUNSHINE. TEMPS EXPECTED TO
RANGE IN MID TO UPPER 30S ACROSS THE NORTHEAST WITH CLOUDS AND AM
SNOW SHOWERS...TO LOWER 40S ACROSS THE SOUTH AND WEST.
FROM TUESDAY NIGHT THROUGH THURSDAY NIGHT HIGH PRESSURE IS
EXPECTED TO BE IN CONTROL ACROSS THE AREA WITH DRY CONDITIONS.
SOME ISSUES WITH CLOUD COVER THROUGH THE PERIOD AS MODELS
CONTINUING TO SHOW SOME WEAK UPPER TROUGHS MOVING THROUGH THE
UPPER FLOW DURING THE PERIOD. DESPITE THAT MAINLY QUIET WEATHER
WITH TEMPS TRENDING TOWARD NORMAL ARE EXPECTED. LEANED TOWARD A
BLEND OF MET MAV AND MEX NUMBER THROUGH THE PERIOD AS SEEING NO
REASON TO DEVIATE MUCH WITH HIGH PRESSURE INFLUENCE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE WILL BE THE DOMINANT FEATURE THROUGH THE EXTENDED EVEN
AS THE CENTER OF IT DRIFTS INTO EASTERN QUEBEC PROVINCE. SO AT THIS
POINT WE EXPECT TO SEE DRY CONDITIONS. THERE MAY BE A SLIGHT
INCREASE IN CLOUD COVER ON SUNDAY AS A STORM SYSTEM TAKES SHAPE OFF
THE MIDDLE ATLANTIC COAST. OTHERWISE EXPECT TO SEE TEMPERATURES NEAR
TO SLIGHTLY BELOW AVERAGE THROUGH THE PERIOD.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
COLD FRONT IS SEEN WELL ON RADAR LOOP STRETCHING FROM JUST EAST OF
KCLE TO KBJJ AT 1740Z. THIS BOUNDARY WILL CONTINUE MOVING EASTWARD
THROUGH THE AFTERNOON. THERE HAVE BEEN SOME LIGHT SHOWERS AHEAD OF
THE FRONT WHICH HAVE BEEN ENOUGH TO STABILIZE THE LOWER LEVELS AND
KEEP THE STRONGEST WINDS FROM REACHING THE SURFACE. HOWEVER THERE
STILL HAVE BEEN A FEW GUSTS WITHIN A COUPLE KNOTS OF 35. AS THE
FRONT PASSES ACROSS THE EAST EXPECT A BRIEF PERIOD OF IFR BEFORE
SLIGHTLY IMPROVING BEHIND THE FRONT. AS THE AIR CHILLS CEILINGS
WILL REMAIN LOW END MVFR INTO THE EVENING. THERE COULD BE SOME
SNOW THAT BEGINS ACROSS THE REGION BY MID AFTERNOON ACROSS THE
WEST THEN PROGRESSING EASTWARD. THIS COUPLE HOUR PERIOD OF SNOW
WILL DRIFT EASTWARD INTO THE EVENING BUT IS NOT EXPECTED TO
PRODUCE ANY SIGNIFICANT ACCUMULATIONS.
CLOUD COVER WILL ATTEMPT TO LIFT AND MAYBE EVEN DISSIPATE ACROSS
THE SOUTHWESTERN COUNTY WARNING AREA DURING THE EVENING. WE WILL
THEN WATCH FOR ADDITIONAL CLOUD COVER TO DEVELOP OFF THE LAKES AS
SOME COLDER AIR SPILLS ACROSS THE GREAT LAKES. BELIEVE THE CLOUD
COVER OFF THE LAKES WILL BE MVFR WITH SOME SNOW SHOWERS POSSIBLE
EAST OF CLEVELAND INTO NW PA FOR LATE TONIGHT INTO TUESDAY MORNING.
OUTLOOK...AREAS OF NON VFR NE OH/NW PA ON TUESDAY...ESPECIALLY
CLOSE TO THE LAKE.
&&
.MARINE...
THE COLD FRONT IS JUST EAST OF THE FORECAST AREA. WINDS DIE DOWN
BEHIND THE FRONT BUT AS THE MUCH COLDER AIR MOVES OVER THE LAKE
INCREASED MIXING WILL OCCUR OVER THE LAKE. THE 850MB TEMPS FORECAST
TO DIP TO MINUS 10C BY DAYBREAK TUESDAY. AS A RESULT THE SMALL
CRAFT WILL BE NEEDED OVER MOST OF LAKE THROUGH THE OVERNIGHT HOURS.
THE WINDS WILL DIE DOWN SIGNIFICANTLY BY TOMORROW AFTERNOON AS HIGH
PRESSURE BUILDS OVER THE LAKE. EXPECT CONDITIONS TO REMAIN BELOW
SMALL CRAFT ADVISORY CRITERIA THROUGH THE WEEKEND AS HIGH PRESSURE
WILL REMAIN OVER THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST TUESDAY FOR LEZ145>149.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR
LEZ142>144.
&&
$$
SYNOPSIS...ABE
NEAR TERM...ABE
SHORT TERM...ABE
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...DJB
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1130 AM CST MON NOV 12 2012
.AVIATION 18Z DISCUSSION...
BACK EDGE OF THE CLOUDINESS CURRENTLY STRETCHES ROUGHLY ALONG THE
I-65 CORRIDOR AND IS MOVING EAST. LOW CLOUD AREA EXTENDS BACK TO
THE TN RIVER BUT IS ALSO MOVING QUICKLY EASTWARD. THUS...PRECIP TO
END DURING THE BEGINNING STAGES OF THE TAF PD. ALSO...CLOUDINESS
TO DECREASE AND SKC WILL PREVAIL FOR ALL AREAS BY 00Z. QUIET
CONDITIONS WITH NO CIG OR VSBYS ISSUES THEREAFTER.
&&
.PREV DISCUSSION... /ISSUED 1040 AM CST MON NOV 12 2012/
UPDATE...UPDATED ZONE PACKAGE TO ACCOUNT FOR CURRENT TRENDS.
PREV DISCUSSION... /ISSUED 534 AM CST MON NOV 12 2012/
UPDATE...FOR AVIATION.
AVIATION...
12Z TAFS...COLD FRONT CURRENTLY CROSSING THE AREA WITH WIDESPREAD
SHOWERS. MOSTLY MVFR CONDITIONS EXPECTED THIS MORNING WITH OCNL
IFR. FRONT HAS PASSED KCKV AND IS NEARLY ON KBNA...AND WILL REACH
KCSV ABOUT 17Z. CONDITIONS WILL IMPROVE THROUGH THE DAY WITH VFR
CONDITIONS AT KCKV AND KBNA BY 21Z. HIGH PRESSURE WILL MOVE IN
QUICKLY TONIGHT WITH CLEARING SKIES AND LIGHT N WINDS.
13
PREV DISCUSSION... /ISSUED 302 AM CST MON NOV 12 2012/
SHORT TERM...A COLD FRONT WAS LOCATED JUST WEST OF THE TENNESSEE
RIVER AT 08Z AND CONTINUING ITS EASTWARD PUSH. A BAND OF ELEVATED
CONVECTION EXISTED JUST AHEAD AND BEHIND THE FRONT. POTENTIAL FOR
THUNDER REMAINS PRETTY LOW, WITH POSITIVE CAPES ONLY IN THE 100-200
J/KG RANGE AHEAD OF THE FRONT. NEVERTHELESS, CAN`T RULE OUT A
ROGUE FLASH OF LIGHTNING FROM ONE OF THE HEAVIER SHOWERS/STORMS.
SO, WILL LEAVE THE POTENTIAL FOR ISOLATED THUNDER IN THE FORECAST
UNTIL THE FRONT PASSES.
EARLIER RUC MODEL RUNS SHOWED A BIT SLOWER MOVEMENT OF THE FRONT
THAN PREVIOUSLY EXPECTED, WITH FRONT EXPECTED TO BE NEAR A
SPRINGFIELD TO WAYNESBORO LINE AT 12Z, JUST EAST OF LEBANON AND
PULASKI AT 15Z, NEAR CSV AT 18Z, AND OFF THE CUMBERLAND PLATEAU BY 21Z.
WILL KEEP TEMPS A BIT ELEVATED IN AREAS WHERE RAIN WILL BE FALLING
THIS MORNING SINCE THE EDGE OF THE REALLY CHILLY AIR, WITH
TEMPERATURES IN THE 40S, IS LOCATED ON THE BACK EDGE OF THE POST-
FRONTAL RAIN AREA.
AFTER FRONT PASSES TODAY, DRIER AND COLDER AIR PUSHES INTO THE MID
STATE FOR A FEW DAYS, WITH HIGHS TUESDAY AND WEDNESDAY ONLY
EXPECTED TO BE IN THE UPPER 40S TO MIDDLE 50S. A WIDESPREAD FREEZE
IS EXPECTED TONIGHT AND AGAIN TUESDAY NIGHT, WITH LOWS RANGING MOSTLY
FROM THE UPPER 20S TO LOWER 30S.
ANOTHER SHORTWAVE MOVES IN ON WEDNESDAY, ENHANCING WEAK TROFFINESS
OVER THE SOUTHEASTERN GULF STATE AND TEMPORARY RETROGRESSION OF
SOME LOW LEVEL MOISTURE INTO OUR AREA. HOWEVER, DON`T EXPECT MUCH
MORE THAN AN INCREASE IN CU/STRATOCU OVER MAINLY THE EASTER HALF
OF OUR FORECAST AREA, WHICH WILL ONLY SERVE TO LIMIT THE AVAILABLE
SUNSHINE A BIT AND KEEP THINGS CHILLY. NO RAIN IS EXPECTED.
LONG TERM...YET ANOTHER SHORTWAVE DROPS SOUTHEASTWARD TOWARD OUR
AREA LATE IN THE WEEK, AND IS FORECAST TO CLOSE OFF INVOF THE OHIO
RIVER VALLEY. THIS MAY PRODUCE A CHANCE FOR SHOWERS IN OUR NECK OF
THE WOODS, ESPECIALLY SOUTHERN AND EASTERN AREAS...AND MAY ADD A
SLIGHT CHANCE FOR SHOWERS FOR SOME COUNTIES ON OR AROUND SATURDAY.
HOWEVER...MODELS SHOW THIS LOW PRESSURE AREA PULLING EAST OF OUR
AREA BY LATE WEEKEND AND EARLY NEXT WEEK AND PUSHING ANY SHOWERS
EAST OF OUR FORECAST AREA.
19
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1040 AM CST MON NOV 12 2012
.UPDATE...UPDATED ZONE PACKAGE TO ACCOUNT FOR CURRENT TRENDS.
&&
.PREV DISCUSSION... /ISSUED 534 AM CST MON NOV 12 2012/
UPDATE...FOR AVIATION.
AVIATION...
12Z TAFS...COLD FRONT CURRENTLY CROSSING THE AREA WITH WIDESPREAD
SHOWERS. MOSTLY MVFR CONDITIONS EXPECTED THIS MORNING WITH OCNL
IFR. FRONT HAS PASSED KCKV AND IS NEARLY ON KBNA...AND WILL REACH
KCSV ABOUT 17Z. CONDITIONS WILL IMPROVE THROUGH THE DAY WITH VFR
CONDITIONS AT KCKV AND KBNA BY 21Z. HIGH PRESSURE WILL MOVE IN
QUICKLY TONIGHT WITH CLEARING SKIES AND LIGHT N WINDS.
13
PREV DISCUSSION... /ISSUED 302 AM CST MON NOV 12 2012/
SHORT TERM...A COLD FRONT WAS LOCATED JUST WEST OF THE TENNESSEE
RIVER AT 08Z AND CONTINUING ITS EASTWARD PUSH. A BAND OF ELEVATED
CONVECTION EXISTED JUST AHEAD AND BEHIND THE FRONT. POTENTIAL FOR
THUNDER REMAINS PRETTY LOW, WITH POSITIVE CAPES ONLY IN THE 100-200
J/KG RANGE AHEAD OF THE FRONT. NEVERTHELESS, CAN`T RULE OUT A
ROGUE FLASH OF LIGHTNING FROM ONE OF THE HEAVIER SHOWERS/STORMS.
SO, WILL LEAVE THE POTENTIAL FOR ISOLATED THUNDER IN THE FORECAST
UNTIL THE FRONT PASSES.
EARLIER RUC MODEL RUNS SHOWED A BIT SLOWER MOVEMENT OF THE FRONT
THAN PREVIOUSLY EXPECTED, WITH FRONT EXPECTED TO BE NEAR A
SPRINGFIELD TO WAYNESBORO LINE AT 12Z, JUST EAST OF LEBANON AND
PULASKI AT 15Z, NEAR CSV AT 18Z, AND OFF THE CUMBERLAND PLATEAU BY 21Z.
WILL KEEP TEMPS A BIT ELEVATED IN AREAS WHERE RAIN WILL BE FALLING
THIS MORNING SINCE THE EDGE OF THE REALLY CHILLY AIR, WITH
TEMPERATURES IN THE 40S, IS LOCATED ON THE BACK EDGE OF THE POST-
FRONTAL RAIN AREA.
AFTER FRONT PASSES TODAY, DRIER AND COLDER AIR PUSHES INTO THE MID
STATE FOR A FEW DAYS, WITH HIGHS TUESDAY AND WEDNESDAY ONLY
EXPECTED TO BE IN THE UPPER 40S TO MIDDLE 50S. A WIDESPREAD FREEZE
IS EXPECTED TONIGHT AND AGAIN TUESDAY NIGHT, WITH LOWS RANGING MOSTLY
FROM THE UPPER 20S TO LOWER 30S.
ANOTHER SHORTWAVE MOVES IN ON WEDNESDAY, ENHANCING WEAK TROFFINESS
OVER THE SOUTHEASTERN GULF STATE AND TEMPORARY RETROGRESSION OF
SOME LOW LEVEL MOISTURE INTO OUR AREA. HOWEVER, DON`T EXPECT MUCH
MORE THAN AN INCREASE IN CU/STRATOCU OVER MAINLY THE EASTER HALF
OF OUR FORECAST AREA, WHICH WILL ONLY SERVE TO LIMIT THE AVAILABLE
SUNSHINE A BIT AND KEEP THINGS CHILLY. NO RAIN IS EXPECTED.
LONG TERM...YET ANOTHER SHORTWAVE DROPS SOUTHEASTWARD TOWARD OUR
AREA LATE IN THE WEEK, AND IS FORECAST TO CLOSE OFF INVOF THE OHIO
RIVER VALLEY. THIS MAY PRODUCE A CHANCE FOR SHOWERS IN OUR NECK OF
THE WOODS, ESPECIALLY SOUTHERN AND EASTERN AREAS...AND MAY ADD A
SLIGHT CHANCE FOR SHOWERS FOR SOME COUNTIES ON OR AROUND SATURDAY.
HOWEVER...MODELS SHOW THIS LOW PRESSURE AREA PULLING EAST OF OUR
AREA BY LATE WEEKEND AND EARLY NEXT WEEK AND PUSHING ANY SHOWERS
EAST OF OUR FORECAST AREA.
19
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
18
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
534 AM CST MON NOV 12 2012
.UPDATE...FOR AVIATION.
&&
.AVIATION...
12Z TAFS...COLD FRONT CURRENTLY CROSSING THE AREA WITH WIDESPREAD
SHOWERS. MOSTLY MVFR CONDITIONS EXPECTED THIS MORNING WITH OCNL
IFR. FRONT HAS PASSED KCKV AND IS NEARLY ON KBNA...AND WILL REACH
KCSV ABOUT 17Z. CONDITIONS WILL IMPROVE THROUGH THE DAY WITH VFR
CONDITIONS AT KCKV AND KBNA BY 21Z. HIGH PRESSURE WILL MOVE IN
QUICKLY TONIGHT WITH CLEARING SKIES AND LIGHT N WINDS.
13
&&
.PREV DISCUSSION... /ISSUED 302 AM CST MON NOV 12 2012/
SHORT TERM...A COLD FRONT WAS LOCATED JUST WEST OF THE TENNESSEE
RIVER AT 08Z AND CONTINUING ITS EASTWARD PUSH. A BAND OF ELEVATED
CONVECTION EXISTED JUST AHEAD AND BEHIND THE FRONT. POTENTIAL FOR
THUNDER REMAINS PRETTY LOW, WITH POSITIVE CAPES ONLY IN THE 100-200
J/KG RANGE AHEAD OF THE FRONT. NEVERTHELESS, CAN`T RULE OUT A
ROGUE FLASH OF LIGHTNING FROM ONE OF THE HEAVIER SHOWERS/STORMS.
SO, WILL LEAVE THE POTENTIAL FOR ISOLATED THUNDER IN THE FORECAST
UNTIL THE FRONT PASSES.
EARLIER RUC MODEL RUNS SHOWED A BIT SLOWER MOVEMENT OF THE FRONT
THAN PREVIOUSLY EXPECTED, WITH FRONT EXPECTED TO BE NEAR A
SPRINGFIELD TO WAYNESBORO LINE AT 12Z, JUST EAST OF LEBANON AND
PULASKI AT 15Z, NEAR CSV AT 18Z, AND OFF THE CUMBERLAND PLATEAU BY 21Z.
WILL KEEP TEMPS A BIT ELEVATED IN AREAS WHERE RAIN WILL BE FALLING
THIS MORNING SINCE THE EDGE OF THE REALLY CHILLY AIR, WITH
TEMPERATURES IN THE 40S, IS LOCATED ON THE BACK EDGE OF THE POST-
FRONTAL RAIN AREA.
AFTER FRONT PASSES TODAY, DRIER AND COLDER AIR PUSHES INTO THE MID
STATE FOR A FEW DAYS, WITH HIGHS TUESDAY AND WEDNESDAY ONLY
EXPECTED TO BE IN THE UPPER 40S TO MIDDLE 50S. A WIDESPREAD FREEZE
IS EXPECTED TONIGHT AND AGAIN TUESDAY NIGHT, WITH LOWS RANGING MOSTLY
FROM THE UPPER 20S TO LOWER 30S.
ANOTHER SHORTWAVE MOVES IN ON WEDNESDAY, ENHANCING WEAK TROFFINESS
OVER THE SOUTHEASTERN GULF STATE AND TEMPORARY RETROGRESSION OF
SOME LOW LEVEL MOISTURE INTO OUR AREA. HOWEVER, DON`T EXPECT MUCH
MORE THAN AN INCREASE IN CU/STRATOCU OVER MAINLY THE EASTER HALF
OF OUR FORECAST AREA, WHICH WILL ONLY SERVE TO LIMIT THE AVAILABLE
SUNSHINE A BIT AND KEEP THINGS CHILLY. NO RAIN IS EXPECTED.
LONG TERM...YET ANOTHER SHORTWAVE DROPS SOUTHEASTWARD TOWARD OUR
AREA LATE IN THE WEEK, AND IS FORECAST TO CLOSE OFF INVOF THE OHIO
RIVER VALLEY. THIS MAY PRODUCE A CHANCE FOR SHOWERS IN OUR NECK OF
THE WOODS, ESPECIALLY SOUTHERN AND EASTERN AREAS...AND MAY ADD A
SLIGHT CHANCE FOR SHOWERS FOR SOME COUNTIES ON OR AROUND SATURDAY.
HOWEVER...MODELS SHOW THIS LOW PRESSURE AREA PULLING EAST OF OUR
AREA BY LATE WEEKEND AND EARLY NEXT WEEK AND PUSHING ANY SHOWERS
EAST OF OUR FORECAST AREA.
19
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
302 AM CST MON NOV 12 2012
.SHORT TERM...A COLD FRONT WAS LOCATED JUST WEST OF THE TENNESSEE
RIVER AT 08Z AND CONTINUING ITS EASTWARD PUSH. A BAND OF ELEVATED
CONVECTION EXISTED JUST AHEAD AND BEHIND THE FRONT. POTENTIAL FOR
THUNDER REMAINS PRETTY LOW, WITH POSTIVE CAPES ONLY IN THE 100-200
J/KG RANGE AHEAD OF THE FRONT. NEVERTHELESS, CAN`T RULE OUT A
ROGUE FLASH OF LIGHTNING FROM ONE OF THE HEAVIER SHOWERS/STORMS.
SO, WILL LEAVE THE POTENTIAL FOR ISOLATED THUNDER IN THE FORECAST
UNTIL THE FRONT PASSES.
EARLIER RUC MODEL RUNS SHOWED A BIT SLOWER MOVEMENT OF THE FRONT
THAN PREVIOUSLY EXPECTED, WITH FRONT EXPECTED TO BE NEAR A
SPRINGFIELD TO WAYNESBORO LINE AT 12Z, JUST EAST OF LEBANON AND
PULASKI AT 15Z, NEAR CSV AT 18Z, AND OFF THE CUMBERLAND PLATEAU BY 21Z.
WILL KEEP TEMPS A BIT ELEVATED IN AREAS WHERE RAIN WILL BE FALLING
THIS MORNING SINCE THE EDGE OF THE REALLY CHILLY AIR, WITH
TEMPERATURES IN THE 40S, IS LOCATED ON THE BACK EDGE OF THE POST-
FRONTAL RAIN AREA.
AFTER FRONT PASSES TODAY, DRIER AND COLDER AIR PUSHES INTO THE MID
STATE FOR A FEW DAYS, WITH HIGHS TUESDAY AND WEDNESDAY ONLY
EXPECTED TO BE IN THE UPPER 40S TO MIDDLE 50S. A WIDESPREAD FREEZE
IS EXPECTED TONIGHT AND AGAIN TUESDAY NIGHT, WITH LOWS RANGING MOSTLY
FROM THE UPPER 20S TO LOWER 30S.
ANOTHER SHORTWAVE MOVES IN ON WEDNESDAY, ENHANCING WEAK TROFFINESS
OVER THE SOUTHEASTERN GULF STATE AND TEMPORARY RETROGRESSION OF
SOME LOW LEVEL MOISTURE INTO OUR AREA. HOWEVER, DON`T EXPECT MUCH
MORE THAN AN INCREASE IN CU/STRATOCU OVER MAINLY THE EASTER HALF
OF OUR FORECAST AREA, WHICH WILL ONLY SERVE TO LIMIT THE AVAILABLE
SUNSHINE A BIT AND KEEP THINGS CHILLY. NO RAIN IS EXPECTED.
.LONG TERM...YET ANOTHER SHORTWAVE DROPS SOUTHEASTWARD TOWARD OUR
AREA LATE IN THE WEEK, AND IS FORECAST TO CLOSE OFF INVOF THE OHIO
RIVER VALLEY. THIS MAY PRODUCE A CHANCE FOR SHOWERS IN OUR NECK OF
THE WOODS, ESPECIALLY SOUTHERN AND EASTERN AREAS...AND MAY ADD A
SLIGHT CHANCE FOR SHOWERS FOR SOME COUNTIES ON OR AROUND SATURDAY.
HOWEVER...MODELS SHOW THIS LOW PRESSURE AREA PULLING EAST OF OUR
AREA BY LATE WEEKEND AND EARLY NEXT WEEK AND PUSHING ANY SHOWERS
EAST OF OUR FORECAST AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 54 30 52 32 / 100 0 0 0
CLARKSVILLE 49 28 50 30 / 80 0 0 0
CROSSVILLE 58 28 49 29 / 100 20 0 0
COLUMBIA 56 30 53 32 / 100 0 0 0
LAWRENCEBURG 57 29 54 31 / 90 0 0 0
WAVERLY 50 29 52 30 / 80 0 0 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
19
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1119 PM CST SUN NOV 11 2012
.DISCUSSION...
SEE AVIATION DISCUSSION.
&&
.AVIATION...
A COLD FRONT IS IN THE PROCESS OF MOVING THROUGH THE REGION. SHRA
HAVE BEEN SPOTTY AT BEST AND SHOULD END AROUND 09Z AREAWIDE. WINDS
WILL INCREASE BRIEFLY BEHIND THE FRONT AND WILL INCREASE AGAIN
ONCE THE 850 FRONT CROSSES THE AREA AROUND SUNRISE. SKIES WILL
ALSO BEGIN TO CLEAR FROM WEST TO EAST OVERNIGHT AND VFR CONDS
EXPECTED THROUGH MONDAY NIGHT. 43
&&
.PREV DISCUSSION... /ISSUED 850 PM CST SUN NOV 11 2012/
UPDATE...
EVENING FORECAST UPDATE.
DISCUSSION...
COLD FRONT HAS PUSHED THROUGH A LUFKIN...CONROE...COLUMBUS LINE
THIS EVENING. TEMPS HAVE DROPPED INTO THE UPPER 50S BEHIND THE
FRONT FROM COLLEGE STATION TO HUNTSVILLE. THINK THE FRONT SHOULD
REACH THE HOUSTON AREA PROBABLY AROUND 9-10PM CST AND MAYBE THE
COAST BY MIDNIGHT. MAINLY EXPECTING SHOWERS WITH PERHAPS AN ISO
THUNDERSTORM SO TRIMMED BACK POPS OVER THE NEXT FEW HOURS TO 40
PERCENT. RAP AND OTHER MESO MODELS SHOW A MORE ROBUST LINE OF
SHOWERS AND THUNDERSTORMS ALONG AND OFF THE COAST SO LEFT SOME
HIGHER POPS FOR THE COASTAL AREAS THROUGH MONDAY MORNING.
SECONDARY COLD AIR PUSH HAS NOW PUSHED THROUGH A LONGVIEW TO WACO
LINE AND CATCH UP WITH CURRENT COLD FRONT PUSHING THROUGH THE
AREA. MIN TEMPS MON MORNING LOOK ON TRACK WITH UPPER 40S TO THE
NORTH AND 50S FOR THE REST OF THE AREA. UPDATED FORECAST AND
PRODUCTS HAVE BEEN SENT.
39
PREV DISCUSSION... /ISSUED 324 PM CST SUN NOV 11 2012/
DISCUSSION...
CF IS THROUGH WACO AND TEMPLE AND HEADED FOR CLL 5-6 PM. RAP AND
LOCAL WRF ARE IN GOOD AGREEMENT THAT THE FRONT WILL REACH IAH
AROUND 9 PM AND THEN NEAR THE COAST AROUND MIDNIGHT. THE CAP HAS
HELD STRONG ACROSS SE TX TODAY...WITH THE ONLY TSTMS NORTH OF THE
AREA SO FAR AND WITHIN THE SVR TSTM WATCH AREA. EXPECT TO SEE SOME
TSTMS DEVELOP ACROSS NORTHERN AREAS DURING THE NEXT COUPLE HOURS
AS THE FRONT APPROACHES. STILL A SLIGHT RISK OF SVR TSTMS ACROSS
NORTHERN AREAS AND THIS THREAT APPEARS TO BE UNTIL AROUND 9
PM...WITH ISOLATED STRONG WIND GUSTS A POSSIBILITY WITH ANY
STRONG/SEVERE STORM THAT DEVELOPS. LOWERED POPS A LITTLE ACROSS
SOUTHWEST AREAS THIS EVENING AS THE CAP MAY BE PROBLEMATIC FOR
PRECIP...EVEN WITH THE BOUNDARY.
PREFER THE GFS FOR THE FORECAST...ALTHOUGH NO SIGNIFICANT
DIFFERENCES BETWEEN THE ECMWF/GFS AS THE GFS HAS TRENDED COLDER
TOWARD THE END OF THE WEEK WITH NW FLOW ALOFT AND ANOTHER
REINFORCING COOL PUSH ON WED BEHIND A SHORT WAVE TROF. STILL DO
NOT THINK WE WILL SEE RAIN WITH THIS DISTURBANCE ACROSS SOUTHERN
AREAS ON TUE NIGHT AS THE ATMOSPHERE IS VERY DRY IN THE LOW-
LEVELS. WE WILL SEE SOME ADDITIONAL MID-LEVEL CLOUD COVER. MADE
SOME COOLER ADJUSTMENTS TO THE FORECAST ESPECIALLY FOR MIN TEMPS
THU...FRI...AND SAT. WILL SEE MIN TEMPS IN THE MID 30S ACROSS
NORTHERN AREAS TUE THROUGH THU MORNINGS.
THE NEXT RAIN CHANCE APPEARS TO BE NEXT WEEKEND AS MOISTURE
RETURNS AND A MID/UPPER TROUGH MOVES ACROSS. 33
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 47 66 37 64 39 / 40 0 0 0 0
HOUSTON (IAH) 56 69 41 66 42 / 40 0 0 0 0
GALVESTON (GLS) 61 71 50 66 49 / 40 0 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST TUESDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...39
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
538 PM CST TUE NOV 13 2012
.SHORT TERM...THROUGH FRIDAY
241 PM CST TUE NOV 13 2012
MAIN FORECAST CONCERN REMAINS ON CLOUDS AND TEMPERATURES...ALONG
WITH SMALL PRECIPITATION POTENTIAL...WITH THE GENERALLY QUIET
WEATHER PATTERN IN PLACE NOW.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHTS SHOWED
NEARLY ZONAL FLOW ACROSS THE U.S....WITH A PERTURBATION IN THE FLOW
OVER WESTERN PORTIONS OF NEBRASKA AND KANSAS ASSOCIATED WITH A
SHORTWAVE TROUGH. ANOTHER WEAKER SHORTWAVE WAS NOTED OVER NORTH
DAKOTA. THE ZONAL FLOW HAS HELPED TO SPREAD WARMER AIR INTO THE
FORECAST AREA...REFLECTED BY THE 12Z MPX SOUNDING 850MB TEMP WHICH
CLIMBED FROM -13C AT 00Z TO -6C AT 12Z. EVEN WARMER AIR WAS PRESENT
TO THE WEST AT BIS AND ABR WHICH WERE AROUND -1C. THE COMBINATION OF
THIS WARMER AIR ALOFT...FULL SUNSHINE FOR MUCH OF THE DAY...AND DRY
AIR SHOWN TOO ON THE 12Z MPX SOUNDING HAS HELPED TEMPERATURES
REBOUND INTO THE 30S AFTER A CHILLY DAY YESTERDAY. SATELLITE IMAGERY
AND SURFACE OBS SHOWED A MASS OF MID AND HIGH CLOUDS SPREADING EAST
FROM THE DAKOTAS INTO MINNESOTA AND IOWA....DOWNSTREAM OF THE TWO
SHORTWAVES IN THE PLAINS. RADAR IMAGERY EVEN HAS SOME LIGHT DBZ
ECHOES BUT ARE ALL JUST VIRGA DUE TO DRY LOW LEVEL AIR IN PLACE. AT
THE SURFACE...A RIDGE OF HIGH PRESSURE EXTENDED FROM CHICAGO TO
NORTHEAST TEXAS WHILE A SURFACE TROUGH EXTENDED FROM NORTHWEST
ONTARIO TO PIERRE SOUTH DAKOTA.
TONIGHT AND WEDNESDAY...THE WEAK SHORTWAVE OVER NORTH DAKOTA IS
SLATED TO CROSS NORTHERN MINNESOTA AND INTO WESTERN LAKE SUPERIOR BY
12Z WEDNESDAY. GIVEN THE TRACK...BEST UPPER LEVEL PV ADVECTION STAYS
OFF TO OUR NORTH. WE DO HAVE A WARM ADVECTION PATTERN IN PLACE...AND
285-295K ISENTROPIC LIFT PLOTS REFLECT THAT. THE BEST ISENTROPIC
LIFT IS FORECAST TO OCCUR OVER THE FORECAST AREA...BUT THE LOWER
CONDENSATION PRESSURE DEFICITS ARE MOSTLY TO THE NORTH OF THE LIFT.
IF THERE IS ANY JUXTAPOSITION OF THE LIFT AND MOISTURE IS ALONG A
STRETCH BETWEEN RED WING AND TAYLOR COUNTY INTO NORTHEAST WISCONSIN.
MOST 13.12Z MODEL QPF OUTPUT FROM THE NAM...GFS AND ECMWF AS WELL AS
THE 13.15Z SREF MEAN SUGGEST A DRY FORECAST LIKE WE HAD GOING...BUT
THE 13.12Z GEM REGIONAL DOES HAVE LIGHT QPF. THINK THERE IS ENOUGH
SUGGESTION FROM THE MODELS TO HAVE AT LEAST A FLURRY MENTION.
NOTE...THOUGH...THERE IS A WARM LAYER AROUND 2000 FT WHICH COULD
MELT THE FLURRIES INTO SPRINKLES. WET-BULBING IS POSSIBLE...BUT
WOULD NOT BE APPROPRIATE GIVEN THE WEAK LIFT. MAY HAVE TO WATCH FOR
THE SPRINKLES TO FREEZE IF THE SURFACE TEMPERATURE CANNOT CLIMB
ABOVE FREEZING. OUTSIDE OF THIS VERY SMALL PRECIPITATION
POTENTIAL...THE MID AND HIGH CLOUDS SEEN OVER THE DAKOTAS WILL
SPREAD INTO THE AREA TONIGHT...THOUGH...WITH PARTIAL CLEARING
PROGGED TO OCCUR WEST TO EAST DURING THE DAY WEDNESDAY IN THE WAKE
OF THE SHORTWAVE. EXPECT WARMER TEMPERATURES TONIGHT THANKS TO THE
CLOUDS...BUT THE SLIGHTLY LATER ARRIVAL FOR THEM IN WISCONSIN COULD
ALLOW THE TYPICAL COLD SPOTS TO DROP INTO THE MID 20S BEFORE
CLIMBING. MOST OTHER LOCATIONS SHOULD BE NEAR 30 FOR LOWS. WARMER
850MB TEMPS ON WEDNESDAY OF 0-2C COMBINED WITH SOME SUNSHINE SHOULD
YIELD WARMER HIGHS AS WELL. A BLEND OF GUIDANCE SEEMED
REASONABLE...YIELDING MID 40S TO LOW 50S.
WEDNESDAY NIGHT AND THURSDAY...MODELS DEPICT A POTENT SHORTWAVE
TROUGH...CURRENTLY NEAR THE ALASKA/YUKON BORDER...TO DROP DOWN INTO
SASKATCHEWAN AND MANITOBA BY LATE WEDNESDAY. THIS POTENT SHORTWAVE
HEADS UP INTO HUDSON BAY BY LATE THURSDAY. ALTHOUGH THE SHORTWAVE IS
FAR FROM US...THERE IS A WEAKER SOUTHERN EXTENSION OF THE SHORTWAVE
THAT DROPS SOUTHEAST THROUGH THE AREA ON THURSDAY. A WEAK COLD FRONT
LOOKS TO ACCOMPANY THIS SHORTWAVE AT THE SURFACE. SIMILAR TO THE
SHORTWAVE CROSSING NORTH DAKOTA TONIGHT...THERE IS A WARM ADVECTION
PATTERN IN PLACE WITH AN AREA OF MID AND HIGH CLOUDS LIKELY TO
SPREAD ACROSS AHEAD OF THE SHORTWAVE. HOWEVER...ISENTROPIC LIFT
FIELDS THIS TIME DO NOT DEPICT ANY LIFT. IN ADDITION...THE SUB-CLOUD
LAYER REMAINS DRY ACCORDING TO FORECAST SOUNDINGS. THUS...THE DRY
FORECAST REMAINS. ALSO SIMILAR TO TONIGHT...THERE IS A PERIOD OF
PARTIAL CLEARING WEDNESDAY EVENING BEFORE MORE EXTENSIVE CLOUDS COME
IN TO ALLOW TEMPERATURES TO DROP OFF. THUS...SOME SITES IN WESTERN
WISCONSIN AGAIN COULD DIP INTO THE UPPER 20S BEFORE CLIMBING WITH
THE CLOUD INCREASE. LOWER TO MID 30S LOWS SHOULD BE TYPICAL
ELSEWHERE. SOME AFTERNOON SUN ON THURSDAY COMBINED WITH 850MB TEMPS
AGAIN IN THE 0-2C RANGE SHOULD ALLOW FOR HIGHS AGAIN IN THE MID 40S
TO LOW 50S.
THURSDAY NIGHT AND FRIDAY...IN THE WAKE OF THE WEDNESDAY
NIGHT/THURSDAY SHORTWAVE TROUGH...GOOD MODEL AGREEMENT EXISTS OF
STRENGTHENING UPPER AND SURFACE RIDGING BUILDING INTO THE FORECAST
AREA. BY 12Z FRIDAY...MUCH OF THE AREA IS ENCOMPASSED BY A SURFACE
HIGH PRESSURE RIDGE. CLEARING SKIES AND SUBSIDENCE IN THE WAKE OF
THE SHORTWAVE TROUGH...COMBINED WITH DRY AIR NOTED BY PRECIPITABLE
WATER VALUES FALLING TO NEAR ONE THIRD OF AN INCH AND LIGHT WINDS
SHOULD SUPPORT GOOD RADIATIONAL COOLING CONDITIONS. THUS...STAYED
TOWARDS THE LOW END OF GUIDANCE...ESPECIALLY AT THE TYPICAL COLD
SPOTS IN WISCONSIN WHICH COULD DIP INTO THE LOWER 20S. SUNNY SKIES
ON FRIDAY COMBINED WITH DRY AIR AND 850MB TEMPS AROUND 0C SHOULD
LEAD TO A DECENT TEMPERATURE RISE. FOLLOWED A BLEND OF GUIDANCE WITH
HIGHS IN THE 40S WHICH SEEMED REASONABLE...WARMEST OVER THE SOUTHERN
HALF OF THE AREA WHERE SLIGHTLY WARMER 925MB TEMPS EXIST.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
241 PM CST TUE NOV 13 2012
13.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES CONTINUE TO SHOW UPPER
AND SURFACE RIDGING PRETTY MUCH DOMINATING THE AREA THROUGH THE
WEEKEND. THIS IS AHEAD OF A DEEP EAST PACIFIC TROUGH AND SOME WEAK
SUBTROPICAL SHORTWAVES LIFTING OUT OF THE FOUR CORNERS REGION AND
INTO THE NORTHERN PLAINS. THIS SETUP SHOULD KEEP THE AREA DRY WITH
TEMPERATURES GRADUALLY WARMING AS THE SURFACE HIGH FROM FRIDAY JUST
SLOWLY SHIFTS EAST. 850MB TEMPS TOP OUT IN THE 2C EAST TO 4C WEST
RANGE FOR THE WEEKEND WHICH SHOULD RESULT IN HIGHS IN THE MID 40S TO
LOWER 50S. LOWS ARE A LITTLE TRICKY...ESPECIALLY OVER WISCONSIN
WHERE LIGHT WINDS AT NIGHT ASSOCIATED WITH THE SURFACE RIDGE AND
MOSTLY CLEAR SKIES COULD ALLOW FOR QUICK TEMPERATURE DROPS.
FOR EARLY NEXT WEEK....THERE ARE ISSUES BEGINNING TO SHOW UP WITH
THE HANDLING OF THAT DEEP EAST PACIFIC TROUGH. ALL MODELS HAVE THE
TROUGH MOVING INLAND ON MONDAY...BUT THE 13.06Z/12Z GFS DRIVE MUCH
OF IT INTO THE WESTERN U.S. AS A BROAD TROUGH. COMPARE THIS TO THE
13.00Z ECMWF AND 13.12Z CANADIAN WHICH ARE MORE LIFT A LOT UP INTO
CANADA WHICH RESULTS IN A ZONAL FLOW PATTERN FROM THE PACIFIC
NORTHWEST INTO THE NORTHERN PLAINS BY TUESDAY. INTERESTINGLY...THE
NEW 13.12Z ECMWF HAS TRENDED TOWARDS THE GFS SCENARIO. GIVEN THE
ECMWF TREND...HAVE LEANED A LITTLE MORE IN THE GFS/ECMWF DIRECTION.
THIS SCENARIO WILL BRING A LOW PRESSURE SYSTEM AT US FROM THE
PLAINS...WITH VARYING INTENSITY DEPENDING ON HOW MUCH OF THAT UPPER
TROUGH DIGS INTO THE PLAINS. GULF OF MEXICO MOISTURE SHOULD RETURN
AHEAD OF IT...THUS HAVE PRECIPITATION CHANCES IN FOR SOUTH OF I-90
MONDAY NIGHT AND AREA WIDE ON TUESDAY. THE GENERAL WARM AIRMASS
SHOULD KEEP THE TYPE AS RAIN. REGARDING TEMPS...850MB TEMPS HOLD IN
THE 2-4C RANGE...YIELDING HIGHS STILL IN THE MID 40S TO LOW 50S.
LOOKING AHEAD TO THANKSGIVING...WITH THE MODEL TREND ON THE EAST
PACIFIC TROUGH NOW DIGGING INTO THE PLAINS...POTENTIAL EXISTS FOR A
LOW PRESSURE SYSTEM TO BE HANGING AROUND THE AREA WEDNESDAY INTO
THURSDAY. SOME PRECIPITATION THUS LOOKS ON TAP...WITH EITHER RAIN OR
A RAIN AND SNOW MIX THE TYPE. STAY TUNED TO LATER FORECASTS AS
THINGS IRON THEMSELVES OUT.
&&
.AVIATION...TONIGHT AND WEDNESDAY
538 PM CST TUE NOV 13 2012
VFR CONDITIONS EXPECTED AT KRST/KLSE THROUGH THE PERIOD AS A WEAK
SHORTWAVE TROUGH MOVES THROUGH THE UPPER MIDWEST OVERNIGHT. THE
BIG STORY IS AN INCREASE IN BROKEN/OVERCAST CLOUDS MAINLY AROUND 8
TO 9 KFT THROUGH MID-MORNING WEDNESDAY...THEN THOSE CLOUDS WILL EXIT
EAST. A RATHER DRY ATMOSPHERE IN THE LOWER LEVELS COMBINED WITH NO
MAJOR FORCING/LIFT SHOULD PRECLUDE PRECIPITATION. AT KRST...DECENT
MIXING IN AFTERNOON WILL LEAD TO GUSTS UP TO 20 KTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
241 PM CST TUE NOV 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
200 PM CST MON NOV 12 2012
.SHORT TERM...THROUGH THURSDAY
200 PM CST MON NOV 12 2012
MAIN FORECAST CONCERNS ARE ON TEMPERATURES AND IF ANY WEAK SHORTWAVE
TROUGHS IMPACTING THE AREA NEXT FEW DAYS CAN PRODUCE PRECIPITATION.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED WEAK RIDGING OVER THE NORTHERN U.S. ROCKIES AHEAD OF A
SHORTWAVE TROUGH IN EASTERN PORTIONS OF OREGON AND WASHINGTON...AND
PROGRESSIVE DEEP TROUGHING FROM HUDSON BAY SOUTHWARD THROUGH
WISCONSIN AND INTO MISSOURI. PLENTY OF COLD AIR UNDER THIS DEEP
TROUGHING...NOTED BY 12Z MPX SOUNDING REPORTING 925MB AND 850MB
TEMPS OF -11C AND -16C RESPECTIVELY. THE COLD AIR COMBINED WITH
PLENTY OF MOISTURE FROM 900-700MB ON THAT 12Z MPX SOUNDING IN THE
DENDRITIC GROWTH ZONE...AS WELL AS DAYTIME HEATING ADDING A LITTLE
INSTABILITY...HAS RESULTED IN PLENTY OF CLOUDS...FLURRIES AND SNOW
SHOWERS ACROSS MUCH OF THE FORECAST AREA. ONE NARROW BAND EVEN
BROUGHT THE VISIBILITY DOWN TO 1/4SM AT THE OFFICE AND KLSE AIRPORT
FOR ABOUT 10 MINUTES AROUND 18Z. SUBSIDENCE AND DRYING ON THE BACK
SIDE OF THE TROUGH...SEEN IN THE 12Z BIS SOUNDING...IS HELPING TO
CLEAR SKIES OUT ACROSS THE DAKOTAS AND SOUTHWEST MINNESOTA. AT THE
SURFACE...BREEZY CONDITIONS EXIST BETWEEN A RIDGE OF HIGH PRESSURE
OVER THE DAKOTAS AND YESTERDAYS COLD FRONT THAT IS OVER LAKE ERIE.
THE CLOUDS...COLD TEMPERATURES ALOFT AND WIND HAS HELD TEMPERATURES
DOWN IN THE 20S.
TONIGHT AND TUESDAY...MODELS PROG THE WEAK UPPER RIDGE OVER THE
NORTHERN U.S. ROCKIES TO SHIFT EAST INTO THE FORECAST AREA TUESDAY
AFTERNOON AS THE SHORTWAVE TROUGH IN ITS WAKE MOVES INTO NEBRASKA.
WITH THIS RIDGE APPROACHING AND THE DEEP TROUGHING DEPARTING...
EXPECT THE SUBSIDENCE...DRYING AND CLEARING SEEN OVER THE DAKOTAS TO
SHIFT INTO THE FORECAST AREA TONIGHT. THE SURFACE HIGH PRESSURE
RIDGE WILL ALSO ACCOMPANY THE CLEARING...ALLOWING WINDS TO DECOUPLE
AND SET UP FAVORABLE RADIATIONAL COOLING CONDITIONS. IF WE HAD A
SNOWPACK LIKE OVER THE DAKOTAS...CONCERN WOULD BE THERE FOR
TEMPERATURES FALLING AT OR BELOW ZERO. HOWEVER...THE MOSTLY BARE
GROUND SHOULD HELP TO LIMIT THE FALL. STAYED TOWARDS THE LOWER END
OF GUIDANCE...ESPECIALLY AT THE FAVORED COLD SPOTS. CIRRUS CLOUDS
SHOULD BE ON THE INCREASE TUESDAY AFTERNOON AHEAD OF THAT NEXT
SHORTWAVE TROUGH. OTHERWISE DRY AND WARMER CONDITIONS ARE EXPECTED
WITH 850MB TEMPS CLIMBING UP 0 TO -3C. GENERALLY FOLLOWED A BLEND OF
STATISTICAL GUIDANCE SINCE IT SEEMED REASONABLE.
TUESDAY NIGHT AND WEDNESDAY...MODELS HAVE TRENDED MUCH FARTHER SOUTH
WITH THE SHORTWAVE TROUGH COMING INTO NEBRASKA ON TUESDAY...WITH
MOST TAKING IT DOWN INTO ARKANSAS TUESDAY NIGHT. THERE IS ANOTHER
WEAKER SHORTWAVE SUGGESTED TO MOVE ACROSS NORTH DAKOTA AND
MINNESOTA...WHICH MODELS ARE PINGING ON PRODUCING A LITTLE LIGHT
QPF TO THE NORTH OF THE FORECAST AREA BETWEEN 06-18Z WEDNESDAY.
THIS WEAKER SHORTWAVE HAS A BROAD WARM ADVECTION ZONE TO WORK
WITH...BUT THE MOISTURE AVAILABILITY IS TERRIBLE DUE THE CURRENT
DEEP TROUGH SCOURING OUT MOISTURE. GIVEN ALL OF THE ABOVE...A DRY
FORECAST FOR THIS PERIOD REMAINS INTACT. MID AND HIGH LEVEL CLOUDS
STILL LOOK ON TAP TO MOVE THROUGH THE FORECAST AREA DURING THIS
PERIOD...CLEARING OUT IN THE AFTERNOON...ASSOCIATED BOTH WITH THAT
WEAKER SHORTWAVE AND THE BROAD WARM ADVECTION ZONE. THESE CLOUDS
SHOULD LIMIT THE TEMPERATURE FALL TO THE 20S TUESDAY NIGHT...AND
SOME LOCATIONS MAY ONLY DROP TO AROUND 30. WITH 850MB TEMPS AROUND
0C ON WEDNESDAY AND AFTERNOON SUNSHINE...HIGHS SHOULD REACH THE
MID 40S TO LOW 50S AS SUGGESTED BY MOST GUIDANCE.
WEDNESDAY NIGHT AND THURSDAY...A POTENT SHORTWAVE TROUGH IS PROGGED
TO DROP DOWN INTO SASKATCHEWAN LATE WEDNESDAY...MOVING EAST INTO
ONTARIO ON THURSDAY. 12.12Z GFS/ECMWF/CANADIAN HAVE BEEN VERY
CONSISTENT ON THIS AND WITH THE TIMING. THE WEAKER SOUTHERN
EXTENSION OF THIS SHORTWAVE LOOKS TO MOVE THROUGH THE FORECAST AREA
DURING THURSDAY AFTERNOON...WITH A VERY WEAK COLD FRONT AS ITS
SURFACE REFLECTION. SIMILAR TO THE TUESDAY NIGHTWEDNESDAY
SITUATION...THIS SHORTWAVE AND COLD FRONT IS MOISTURE STARVED. IF
THERE ARE ANY CLOUDS...THEY ARE MAINLY SOUTH OF I-90 AND OF THE
MID-LEVEL VARIETY...ASSOCIATED WITH THAT BROAD WARM ADVECTION ZONE
REFERENCED IN THE TUESDAY NIGHTWEDNESDAY DISCUSSION. THUS...DRY
CONDITIONS CONTINUE. PRESSURE GRADIENT IS WEAK WEDNESDAY NIGHT SO
CONCERN EXISTS ABOUT TEMPERATURES TANKING...PARTICULARLY NORTH OF
I-90 WHERE LESS CLOUDS EXIST. 30 DAY BIAS CORRECTED GUIDANCE DOES
SHOW THE TYPICAL WISCONSIN COLD SPOTS DROPPING INTO THE LOW 20S...SO
HAVE TRENDED TOWARDS THIS. READINGS FROM THE UPPER 20S TO AT MOST
MID 30S SHOULD BE THE RULE ELSEWHERE. COMBINATION OF SUN AND 850MB
TEMPS HOLDING UP IN THE 0-2C RANGE ON THURSDAY WILL ALLOW
TEMPERATURES TO CLIMB BACK INTO THE MID 40S TO LOW 50S AGAIN. 12.12Z
NAM 2 METER TEMPERATURE OUTPUT IS EVEN HIGHER...MID TO UPPER 50S
ALONG AND WEST OF THE MISSISSIPPI RIVER...BUT IT MIGHT BE MIXING TOO
DEEPLY GIVEN SOME CLOUD CONCERNS. CERTAINLY SOMETHING TO WATCH.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
200 PM CST MON NOV 12 2012
THE LONG TERM FORECAST CONTINUES TO REMAIN QUIET. 12.12Z
ECMWF/CANADIAN/GFS AND GFS ENSEMBLES ARE STILL PAINTING A SIMILAR
PICTURE...SHOWING A SPLIT FLOW PATTERN WITH THE NORTHERN STREAM
STAYING IN CANADA AND THE SOUTHERN STREAM CROSSING THE SOUTHERN
U.S.. IN ADDITION...DEEP TROUGHING IS PROGGED TO DEVELOP OVER THE
EAST PACIFIC...PERHAPS SLIDING INTO THE PACIFIC NORTHWEST ON MONDAY.
THIS TROUGH ONLY HELPS TO LIFT THE NORTHERN STREAM FARTHER NORTH
THROUGH CANADA AND MAY EVEN TRY TO BUILD A SOUTHERN STREAM RIDGE
INTO THE FORECAST AREA. THIS PATTERN KEEPS A FLOW OF PACIFIC AIR
INTO THE FORECAST AREA WHICH SHOULD RESULT IN SLIGHTLY ABOVE NORMAL
TEMPERATURES. 850MB TEMPS OF 0-2C ON FRIDAY LOOK TO CLIMB TO 2-4C
FOR THE WEEKEND AND AROUND 4C BY LATE MONDAY. WITH MOISTURE
EXTREMELY LIMITED ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI
RIVER VALLEY REGIONS...ALONG WITH A GENERAL LACK OF FORCING...HAVE
KEPT THE FORECAST DRY. MUCH OF THE TIME PERIOD IS ALSO DOMINATED BY
HIGH PRESSURE AT THE SURFACE...HELPING TO MAINTAIN A FEED OF LOW
LEVEL DRY AIR INTO THE AREA.
FOR THOSE LOOKING TOWARDS THANKSGIVING NEXT WEEK...IT APPEARS THE
DEEP EAST PACIFIC TROUGH WILL LIFT OUT ACCORDING TO THE 12.12Z
ECMWF/GFS AND LATEST CFS RUNS...RESULTING IN A ZONAL FLOW NEAR THE
U.S./CANADIAN BORDER. IF THIS DOES INDEED PAN OUT...EVEN WARMER
AIR SHOULD ADVECT INTO THE AREA. MAINLY DRY WEATHER PERSISTS TOO.
OF COURSE STAY TUNED TO LATER FORECASTS GIVEN THAT THANKSGIVING IS
STILL 9-10 DAYS OUT.
&&
.AVIATION...THROUGH 18Z TUESDAY
1125 AM CST MON NOV 12 2012
WEAK SHORTWAVE IS PRODUCING SCATTERED FLURRIES AND SNOW SHOWERS
ACROSS THE REGION. SOME VISIBILITY RESTRICTIONS WERE BEING SEEN IN
THE HEAVIER SNOW SHOWERS...DOWN TO AROUND A MILE FOR A BRIEF
PERIOD OF TIME. EXPECT THESE CONDITIONS TO CONTINUE THROUGH THE
AFTERNOON HOURS WITH MAINLY MVFR CEILINGS BETWEEN 015-025K FEET.
HIGH PRESSURE BEGINS TO NOSE IN THIS EVENING AND MODELS SHOW SKIES
SHOULD CLEAR DURING THE EARLY EVENING HOURS...MOSTLY LIKELY
BETWEEN 00Z-03Z...WITH JUST A FEW HIGH CLOUDS AFTER THAT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
200 PM CST MON NOV 12 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
301 AM CST MON NOV 12 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
301 AM CST MON NOV 12 2012
MAIN FORECAST CONCERNS ARE ON FLURRIES AND SNOW SHOWERS TODAY AND
TEMPERATURES THROUGH THE SHORT TERM.
LATEST WATER VAPOR IMAGERY SHOWED A DEEP UPPER LEVEL TROUGH
EXTENDING FROM ALONG THE MANITOBA/ONTARIO BORDER THROUGH WESTERN
MINNESOTA EXTENDING ALL THE WAY INTO THE SOUTHERN PLAINS. UPPER
RIDGING WAS NOTED ACROSS THE WESTERN CONUS. SURFACE OBSERVATIONS
SHOWED SURFACE LOW PRESSURE NEAR THE WESTERN SHORES OF JAMES BAY
WITH A COLD FRONT EXTENDING SOUTH THROUGH EASTERN ONTARIO THROUGH
LOWER MICHIGAN INTO THE WESTERN APPALACHIANS. A SURFACE TROUGH WAS
NOTED ACROSS NORTHWEST MINNESOTA INTO EASTERN SOUTH
DAKOTA...HEADED EAST TOWARD THE AREA.
THE UPPER TROUGH WILL MOVE INTO THE UPPER MISSISSIPPI RIVER VALLEY
TODAY BRINGING MOSTLY CLOUD SKIES AND SCATTERED SNOW SHOWERS AND
FLURRIES TO THE AREA THROUGH MUCH OF THE DAY. THINKING MUCH OF THE
ACTIVITY WILL BE FLURRIES THIS MORNING WITH A DEEP DENDRITIC GROWTH
ZONE OVER THE AREA...EXTENDING FROM AROUND 900MB THROUGH 700MB.
WEAK LIFT WORKING ON THIS NEARLY SATURATED LAYER WILL LIKELY YIELD
FLURRIES. THERE WILL BE A BETTER CHANCE OF SEEING SNOW SHOWERS
THIS AFTERNOON AS THE SURFACE TROUGH MOVES IN AND THE VORTICITY
MAX ASSOCIATED WITH THE UPPER TROUGH MOVES IN. THE STRONGEST PART
OF THE VORTICITY MAX LOOKS TO PASS ACROSS UPPER MICHIGAN/NORTHERN
WISCONSIN THIS AFTERNOON SO HAVE INCREASED SNOW SHOWER CHANCES
ACROSS CLARK AND TAYLOR COUNTIES THIS AFTERNOON. LAPSE RATES
STEEPEN THIS AFTERNOON WITH FORECAST SOUNDINGS SHOWING SOME LOW
LEVEL CAPE...AROUND 70 J/KG ACROSS CENTRAL WISCONSIN AND EXTENDING
SOUTHWEST TO ALONG AND SLIGHTLY WEST OF THE MISSISSIPPI RIVER.
THIS WILL BE ENOUGH INSTABILITY TO SUPPORT SNOW SHOWERS SO HAVE
ADDED ISOLATED SNOW SHOWERS FOR LOCATIONS ALONG AND SOUTH OF
INTERSTATE 94 INTO PORTIONS OF SOUTHEAST MINNESOTA AND EXTREME
NORTHEAST IOWA. LOCATIONS FURTHER SOUTHWEST WILL CONTINUE TO SEE
FLURRIES INTO THE AFTERNOON HOURS. SNOW ACCUMULATIONS AROUND 1/2
INCH ARE POSSIBLE TODAY MAINLY NORTH OF WISCONSIN HIGHWAY 29.
SNOW SHOWERS AND FLURRIES WILL TAPER OFF AND MOVE EAST OF THE AREA
THIS EVENING AS SURFACE HIGH PRESSURE BUILDS INTO THE REGION. PLAN
ON DECREASING CLOUD OVERNIGHT. A RATHER CHILLY NIGHT IS IN STORM FOR
THE FORECAST AREA WITH MOSTLY CLEAR SKIES AND LIGHT WINDS LEADING TO
TEMPERATURES PLUMMETING INTO THE TEENS TO AROUND 20. FLOW ALOFT
WILL TURN ZONAL AS THE UPPER RIDGE OVER THE WESTERN CONUS
FLATTENS. AN EMBEDDED SHORTWAVE IS EXPECTED TO MOVE ACROSS THE
DAKOTAS AND PUSH EAST INTO THE UPPER MISSISSIPPI RIVER VALLEY
TUESDAY NIGHT. THE SHORTWAVE WILL BRINGING INCREASING CLOUDS TO
THE AREA TUESDAY EVENING WITH CLOUDY SKIES EXPECTED DURING THE
OVERNIGHT HOURS. WILL HAVE TO KEEP A CLOSE WATCH ON ISENTROPIC
LIFT ON THE 280 THROUGH 290K SURFACES AS THE WAVE MOVES THROUGH.
CONDENSATION PRESSURE DEFICITS IN THIS LAYER ARE RUNNING AROUND
100 TO 120 MB THROUGH THE OVERNIGHT HOURS SO THINKING IT WILL BE
TOUGH TO SEE MUCH IF ANY PRECIPITATION OUT OF THIS SYSTEM.
FORECAST SOUNDINGS SUGGEST THERE COULD BE SOME LIGHT PRECIPITATION
WITH FAIRLY DEEP SATURATION ALOFT DESPITE THE RATHER DRY SUB CLOUD
LAYER BELOW 800 MB. WILL MAINTAIN DRY FORECAST AT THIS TIME. PLAN
ON SLIGHTLY WARMER TEMPERATURES ON TUESDAY AS THE TROUGH MOVES OFF
TO THE EAST AND THE ZONAL FLOW MOVES OVER THE AREA. LOOK FOR HIGHS
TO RANGE FROM THE MID 30S OVER NORTH CENTRAL WISCONSIN TO AROUND
40 ACROSS NORTHEAST IOWA. WARMER TEMPERATURES ARE EXPECTED ON
WEDNESDAY AS SOUTHERLY WINDS INCREASE AHEAD OF A TROUGH MOVING
ACROSS THE NORTHERN PLAINS. PLAN ON HIGHS RANGING FROM THE LOWER
40S ACROSS NORTHERN WISCONSIN TO THE UPPER 40S OVER NORTHEAST
IOWA.
.LONG TERM...THURSDAY THROUGH SUNDAY
301 AM CST MON NOV 12 2012
12.00 MEDIUM RANGE MODELS ARE IN REASONABLE AGREEMENT THURSDAY
SHOWING ANOTHER SHORTWAVE TROUGH MOVING ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY. AGAIN...MODELS STRUGGLE TO GENERATE ANY PRECIPITATION
WITH A SPLIT FLOW PATTERN DEVELOPING. THE NORTHERN 250 MB JET IS
EXPECTED TO BE ACROSS SOUTHERN CANADA WITH THE SOUTHERN JET OVER THE
SOUTHERN CONUS. THE FORECAST AREA WILL BE BETWEEN THESE TO JETS
WITH LITTLE UPPER LEVEL SUPPORT FOR SHORTWAVES EXPECTED TO MOVE
THROUGH THURSDAY INTO THURSDAY NIGHT. HIGH PRESSURE WILL RETURN
FRIDAY INTO SATURDAY WITH DRY AND QUIET CONDITIONS EXPECTED. PLAN
ON HIGHS ON FRIDAY IN THE 40S...WARMING INTO THE UPPER 40S TO
AROUND 50 ON SATURDAY. THE HIGH IS EXPECTED TO REMAIN IN CONTROL
INTO SUNDAY WITH HIGH TEMPERATURES IN THE 40S.
&&
.AVIATION...THROUGH 06Z TUESDAY
1127 PM CST SUN NOV 11 2012
MVFR STRATUS CONTINUES OVER THE TAF SITES. CLEAR SKIES WERE AS CLOSE
AS FAR NORTHEAST IOWA WITH THE BACK EDGE SLOWLY MOVING NORTHEAST.
12.03Z RAP BUFKIT SOUNDING AND LOW LEVEL RELATIVE HUMIDITY PROGS
INDICATE THIS CLEARING MAY APPROACH THE TAF SITES LATER
TONIGHT...FOR A BRIEF PERIOD OF SCATTERED CLOUDS. HOWEVER...MORE
STRATUS UPSTREAM OVER WESTERN AND NORTHERN MINNESOTA WILL DROP
ACROSS THE AREA AHEAD OF A WEAK SHORTWAVE. STILL EXPECTING MAINLY
MVFR CEILINGS THROUGH THE DAY MONDAY. THERE COULD BE A FEW FLURRIES
FROM TIME TO TIME...BUT DID NOT ADD TO THE TAFS. WEST WINDS WILL
CONTINUE AT GREATER THAN 12 KNOTS...AT LEAST THROUGH 00Z TUESDAY. MODELS
CONSISTENT IN SCATTERING THE CLOUDS OUT SHORTLY AFTER 00Z TUESDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
301 AM CST MON NOV 12 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
930 PM PST TUE NOV 13 2012
.SYNOPSIS...
HIGH PRESSURE ALOFT WILL BRING ANOTHER FAIR MILD DAY
WEDNESDAY...THEN ONSHORE FLOW WILL DEVELOP AND BRING PATCHY DENSE
FOG TO THE COAST WEDNESDAY NIGHT AND THURSDAY MORNING...WITH COOLING
ON THURSDAY. A LOW PRESSURE TROUGH WILL MOVE INTO CALIFORNIA FROM
THE EAST PACIFIC AND BRING SMALL CHANCES OF SHOWERS MAINLY THURSDAY
NIGHT AND AGAIN OVER THE WEEKEND. FAIR WEATHER WILL RETURN BY NEXT
TUESDAY WITH UNDER WEAK HIGH PRESSURE ALOFT.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
SKIES WERE CLEAR AND SHOULD CONTINUE THAT WAY OVERNIGHT EXCEPT FOR
AN INCREASE IN HIGH CLOUDS FROM THE SOUTHWEST. THE THREAT OF ANY FOG
FORMING ALONG THE COAST LOOKS MINIMAL...EVEN THOUGH SOME DEW POINTS
ARE IN THE 50S ALONG THE COAST NOW. THE HRRR AND LOCAL WRF SHOW
DRAINAGE FLOW OVERNIGHT...ESPECIALLY AROUND 09Z...WHICH WOULD BRING
LOWER DEW POINTS FROM INLAND AREAS BACK TO THE COAST. HENCE...HAVE
REMOVED DENSE FOG FROM THE FORECAST FOR TONIGHT AND WED MORNING. AN
EDDY SHOULD DEVELOP WED DURING THE DAY WHICH WOULD SET THE STAGE FOR
SOME DENSE FOG ALONG THE COAST WED NIGHT. REGARDING THE WINDS...THEY
HAVE DECREASED IN MOST AREAS WITH HIGHEST GUSTS AROUND 25 MPH IN THE
SAN DIEGO COUNTY MTNS/SANTA ANA MTNS. EXPECT THESE WINDS TO DECREASE
OVERNIGHT.
OTHERWISE...A HIGH PRESSURE RIDGE HAS A N-S AXIS OVER ARIZONA/NEVADA
WITH A TROUGH NEAR 140 W. THE TROUGH WILL MOVE TOWARDS CALIFORNIA
THROUGH THU...BUT...IT WILL FLATTEN OUT SOMEWHAT. SOME MOISTURE WILL
MOVE IN FROM THE SW FOR THU NIGHT...BUT 00Z NAM AND GFS ARE BOTH
SHOWING LESS MOISTURE THAN WITH PREVIOUS RUNS...AND ALSO THERE WILL
BE SOMEWHAT LIMITED MARINE LAYER MOISTURE. FOR NOW...HAVE KEPT
SLIGHT CHANCES FOR THU NIGHT...BUT ANY PRECIP AMOUNTS WILL BE QUITE
SMALL...GENERALLY A FEW HUNDREDTHS. AFTER THE FIRST SHORT WAVE MOVES
THROUGH FRI MORNING...PRECIP CHANCES LOOK RATHER SMALL NORTH OF SAN
DIEGO COUNTY...AND SAN DIEGO COUNTY HAS JUST PARTLY CLOUDY FOR
FRI/FRI NIGHT WITH NO MENTION OF PRECIP IN THE FORECAST. THE NEXT
SHORT WAVE SHOULD MOVE THROUGH AROUND SAT...THOUGH CONFIDENCE IS
FAIRLY LOW FOR TIMING AND IF ANY PRECIP WILL RESULT THIS FAR SOUTH
DUE TO SOMEWHAT LIMITED MOISTURE AND NOT MUCH OF A TRIGGER. THE LAST
SHORT WAVE WILL PROBABLY MOVE THROUGH SOMETIME AROUND SUN NIGHT/MON
WITH PERHAPS A BIT MORE MOISTURE WITH IT. AFTER THAT...THE LONG WAVE
TROUGH WILL MOVE EAST INTO THE CENTRAL US WITH WEAK RIDGING AND
POSSIBLY WEAK SURFACE OFFSHORE FLOW TUE...ALONG WITH WARMING.
&&
140400Z...A VERY LOW CLOUD DECK IS EXPECTED TO DEVELOP OVER THE
COASTAL WATERS AFTER 15/1200Z AND MOVE SLOWLY NORTHWARD OVER THE
COASTAL WATERS. CLOUD BASES AROUND 200 FT MSL WITH TOPS A COUPLE
HUNDRED FEET HIGHER. HOWEVER...COASTAL AIRPORTS SUCH AS
KSNA...KSAN...AND KCRQ SHOULD BE IN THE CLEAR. CONFIDENCE OF STRATUS
MAKING AN INLAND PUSH IS VERY LOW. OTHERWISE...SKC CONDITIONS
WEDNESDAY WITH A ONLY A FEW PASSING CLOUDS ABV 20000 FT MSL. LOW
CLOUDS/FOG WILL RETURN TO THE COAST AFT 15/0600Z AND ARE EXPECTED TO
PUSH A COUPLE MILES INLAND BY LATE THURSDAY NIGHT.
&&
.MARINE...
ONLY SIGNIFICANT MARINE WEATHER IS THREAT OF DENSE FOG WEDNESDAY
MORNING FORMING AND MOVING NORTH ACROSS INNER WATERS. DENSE FOG IS
AGAIN A THREAT WEDNESDAY EVENING INTO THURSDAY MORNING.
&&
.FIRE WEATHER...
MOST WIND GUSTS ARE NOW LESS THAN 25 MPH. ALTHOUGH THE OFFSHORE WINDS
WILL DIMINISH OVERNIGHT...HUMIDITY RECOVERIES ARE EXPECTED TO BE
POOR AT BEST. HUMIDITIES WILL BE LOW AGAIN ON WEDNESDAY...AND SO
ELEVATED FIRE WEATHER CONDITIONS WILL CONTINUE. HUMIDITIES WILL
GRADUALLY TREND UPWARD THURSDAY THROUGH EARLY NEXT WEEK AS A TROUGH
MOVES IN THROUGH SOUTHERN CALIFORNIA.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC/FIRE WEATHER...MAXWELL
AVIATION/MARINE...JT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
948 PM MST TUE NOV 13 2012
.UPDATE...
ISSUED AT 856 PM MST TUE NOV 13 2012
SURFACE TROUGH TAKING ITS TIME IN MOVING ACROSS THE AREA. NARROW
AREA OF LOW DEWPOINTS AND CALM/NEARLY CALM WINDS IN THE MIDDLE OF
THE FORECAST AREA IS ALLOWING TEMPERATURES TO KEEP FALLING. LATEST
RUC IS CATCHING THE WINDS/TROUGH WELL. HOWEVER...NOTHING IS
CATCHING THE EXTREMELY LOW DEWPOINTS. WINDS MAY NOT TURN TO
WESTERLY UNTIL BETWEEN 06Z AND 12Z SOMETIME. SO LOWERED MINS IN
THE ABOVE MENTIONED AREA AND USED THE RUC FOR THE WIND FORECAST
FOR THE REST OF TONIGHT INTO TOMORROW MORNING.
&&
.SHORT TERM...(THIS AFTERNOON-WEDNESDAY)
ISSUED AT 1145 AM MST TUE NOV 13 2012
CLOUDINESS WILL DECREASE FROM WEST TO EAST THROUGH THE REST OF THE
DAY WITH A CLEAR SKY THROUGH MIDNIGHT. CIRRUS WILL INCREASE AFTER
MIDNIGHT AND CONTINUE THROUGH THE DAY WEDNESDAY. SFC TROUGH WILL
SLOWLY MOVE EAST THROUGH THE REST OF THE DAY AND INTO TONIGHT WITH
NORTHWEST WINDS AROUND 10 MPH. TOWARD SUNRISE WEDNESDAY WINDS WILL
BACK TO THE WEST THEN SOUTH. MAY SEE SOME GUSTS ALONG THE CO/KS
BORDER TO 25 MPH. LOW TEMPERATURES IN THE UPPER TEENS TO MID 20S
TONIGHT WITH HIGH TEMPERATURES WEDNESDAY 55 TO 60.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 138 PM MST TUE NOV 13 2012
A WEAK COLD FRONT WILL PUSH THROUGH THE REGION ON WEDNESDAY NIGHT.
THIS FRONT WILL AMOUNT TO A WIND SHIFT AND SLIGHTLY COOLER
TEMPERATURES. NORTH WINDS WILL PICK UP TUESDAY AFTERNOON AND COULD
BECOME BREEZY. MAXIMUM TEMPERATURES ON THURSDAY WILL RANGE FROM
THE UPPER 40S TO THE UPPER 50S...ONLY A SLIGHT CHANGE FROM
WEDNESDAY.
TEMPERATURES ON FRIDAY WILL WARM BACK UP AS SOUTH WINDS RETURN. HIGH
TEMPERATURES WILL BE AT OR JUST ABOVE NORMAL FOR THIS TIME OF
YEAR. WINDS ON FRIDAY COULD BECOME GUSTY IN THE AFTERNOON AS A
SURFACE HIGH PRESSURE MOVES SLOWLY EAST AND A LEE TROUGH DEVELOPS
TO THE WEST. RELATIVE HUMIDITIES ARE EXPECTED TO BE IN THE LOW TO
MID 30S SO FIRE WEATHER IS NOT FORECAST TO BE A CONCERN AT THE
MOMENT.
THE WEATHER WILL CONTINUE TO BE QUIET INTO NEXT WEEK. MODELS HAVE
COME INTO BETTER AGREEMENT ON A DRY SOLUTION FOR THE WEEKEND.
MODELS HAVE ALSO PUSHED BACK THE SYSTEM THAT WAS ORIGINALLY
FORECAST TO MOVE THROUGH SATURDAY TO SUNDAY. THE CANADIAN STILL
SHOWS A DECENT SHORTWAVE...BUT FARTHER SOUTH AND THUS NO
PRECIPITATION HERE. THE EUROPEAN MODEL SHOWS A DECENT SHORTWAVE
MOVING RIGHT OVER THE TRI-STATE AREA ON SUNDAY...BUT ALL THE
PRECIPITATION DEVELOPS ACROSS THE EASTERN HALF OF KANSAS WHERE
THERE WILL BE MORE MOISTURE TO WORK WITH. THE GFS SHOWS A MUCH
WEAKER SYSTEM WITH NO PRECIPITATION TO SPEAK OF. THEREFORE...HAVE
KEPT CHANCES FOR PRECIPITATION OUT OF THE FORECAST.
AFTER THAT...MODELS BEGIN TO DISAGREE. THE GFS SHOWS A WEAK
DISTURBANCE WITH SOME POSSIBLE PRECIPITATION ON TUESDAY. THE
EUROPEAN IS SUGGESTING THE SAME DISTURBANCE AND ASSOCIATED
PRECIPITATION WILL BE MUCH FARTHER NORTH. HAVE CONTINUED A DRY
FORECAST THROUGH THIS TIME AS WELL DUE TO MODEL DISAGREEMENT AND
LOCAL COLLABORATION.
TEMPERATURES ARE FORECAST TO REMAIN FAIRLY CONSISTENT THROUGH THE
WEEKEND AND EARLY PART OF NEXT WEEK AS A RESULT OF THE CALM
WEATHER PATTERN. HIGHS WILL RANGE FROM THE MID 50S TO NEAR 60 EACH
DAY. LOW TEMPERATURES WILL SLOWLY WARM THROUGH THE FORECAST
PERIOD...REACHING THE MID 30S BY MONDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 945 PM MST TUE NOV 13 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH ONLY VARIABLE
AMOUNTS OF HIGH CLOUD COVER. WINDS WILL GRADUALLY SHIFT TO THE
SOUTH AND BECOME GUSTY AT KGLD DURING THE LATE MORNING AND
AFTERNOON HOURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...99
LONG TERM...RRH
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
901 PM MST TUE NOV 13 2012
.UPDATE...
ISSUED AT 856 PM MST TUE NOV 13 2012
SURFACE TROUGH TAKING ITS TIME IN MOVING ACROSS THE AREA. NARROW
AREA OF LOW DEWPOINTS AND CALM/NEARLY CALM WINDS IN THE MIDDLE OF
THE FORECAST AREA IS ALLOWING TEMPERATURES TO KEEP FALLING. LATEST
RUC IS CATCHING THE WINDS/TROUGH WELL. HOWEVER...NOTHING IS
CATCHING THE EXTREMELY LOW DEWPOINTS. WINDS MAY NOT TURN TO
WESTERLY UNTIL BETWEEN 06Z AND 12Z SOMETIME. SO LOWERED MINS IN
THE ABOVE MENTIONED AREA AND USED THE RUC FOR THE WIND FORECAST
FOR THE REST OF TONIGHT INTO TOMORROW MORNING.
&&
.SHORT TERM...(THIS AFTERNOON-WEDNESDAY)
ISSUED AT 1145 AM MST TUE NOV 13 2012
CLOUDINESS WILL DECREASE FROM WEST TO EAST THROUGH THE REST OF THE
DAY WITH A CLEAR SKY THROUGH MIDNIGHT. CIRRUS WILL INCREASE AFTER
MIDNIGHT AND CONTINUE THROUGH THE DAY WEDNESDAY. SFC TROUGH WILL
SLOWLY MOVE EAST THROUGH THE REST OF THE DAY AND INTO TONIGHT WITH
NORTHWEST WINDS AROUND 10 MPH. TOWARD SUNRISE WEDNESDAY WINDS WILL
BACK TO THE WEST THEN SOUTH. MAY SEE SOME GUSTS ALONG THE CO/KS
BORDER TO 25 MPH. LOW TEMPERATURES IN THE UPPER TEENS TO MID 20S
TONIGHT WITH HIGH TEMPERATURES WEDNESDAY 55 TO 60.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 138 PM MST TUE NOV 13 2012
A WEAK COLD FRONT WILL PUSH THROUGH THE REGION ON WEDNESDAY NIGHT.
THIS FRONT WILL AMOUNT TO A WIND SHIFT AND SLIGHTLY COOLER
TEMPERATURES. NORTH WINDS WILL PICK UP TUESDAY AFTERNOON AND COULD
BECOME BREEZY. MAXIMUM TEMPERATURES ON THURSDAY WILL RANGE FROM
THE UPPER 40S TO THE UPPER 50S...ONLY A SLIGHT CHANGE FROM
WEDNESDAY.
TEMPERATURES ON FRIDAY WILL WARM BACK UP AS SOUTH WINDS RETURN. HIGH
TEMPERATURES WILL BE AT OR JUST ABOVE NORMAL FOR THIS TIME OF
YEAR. WINDS ON FRIDAY COULD BECOME GUSTY IN THE AFTERNOON AS A
SURFACE HIGH PRESSURE MOVES SLOWLY EAST AND A LEE TROUGH DEVELOPS
TO THE WEST. RELATIVE HUMIDITIES ARE EXPECTED TO BE IN THE LOW TO
MID 30S SO FIRE WEATHER IS NOT FORECAST TO BE A CONCERN AT THE
MOMENT.
THE WEATHER WILL CONTINUE TO BE QUIET INTO NEXT WEEK. MODELS HAVE
COME INTO BETTER AGREEMENT ON A DRY SOLUTION FOR THE WEEKEND.
MODELS HAVE ALSO PUSHED BACK THE SYSTEM THAT WAS ORIGINALLY
FORECAST TO MOVE THROUGH SATURDAY TO SUNDAY. THE CANADIAN STILL
SHOWS A DECENT SHORTWAVE...BUT FARTHER SOUTH AND THUS NO
PRECIPITATION HERE. THE EUROPEAN MODEL SHOWS A DECENT SHORTWAVE
MOVING RIGHT OVER THE TRI-STATE AREA ON SUNDAY...BUT ALL THE
PRECIPITATION DEVELOPS ACROSS THE EASTERN HALF OF KANSAS WHERE
THERE WILL BE MORE MOISTURE TO WORK WITH. THE GFS SHOWS A MUCH
WEAKER SYSTEM WITH NO PRECIPITATION TO SPEAK OF. THEREFORE...HAVE
KEPT CHANCES FOR PRECIPITATION OUT OF THE FORECAST.
AFTER THAT...MODELS BEGIN TO DISAGREE. THE GFS SHOWS A WEAK
DISTURBANCE WITH SOME POSSIBLE PRECIPITATION ON TUESDAY. THE
EUROPEAN IS SUGGESTING THE SAME DISTURBANCE AND ASSOCIATED
PRECIPITATION WILL BE MUCH FARTHER NORTH. HAVE CONTINUED A DRY
FORECAST THROUGH THIS TIME AS WELL DUE TO MODEL DISAGREEMENT AND
LOCAL COLLABORATION.
TEMPERATURES ARE FORECAST TO REMAIN FAIRLY CONSISTENT THROUGH THE
WEEKEND AND EARLY PART OF NEXT WEEK AS A RESULT OF THE CALM
WEATHER PATTERN. HIGHS WILL RANGE FROM THE MID 50S TO NEAR 60 EACH
DAY. LOW TEMPERATURES WILL SLOWLY WARM THROUGH THE FORECAST
PERIOD...REACHING THE MID 30S BY MONDAY NIGHT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 423 PM MST TUE NOV 13 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH ONLY VARIABLE
HIGH CLOUD COVER EXPECTED. VARIABLE AND SHIFTING WINDS ARE
EXPECTED AS A COUPLE OF SURFACE TROUGHS MOVE THROUGH THE AREA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...99
LONG TERM...RRH
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
328 AM EST WED NOV 14 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BRING DRY AND COOL CONDITIONS
THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
BIGGEST ISSUE IN THE NEAR TERM WILL BE DETERMINING WHEN CLOUDS WILL
GO AWAY. 850MB COLD POOL DIDN/T ALLOW MUCH CLEARING YESTERDAY...AND
EROSION PROCESS IS VERY SLOW DURING THE OVERNIGHT HOURS TO THE SOUTH
AND WEST OF PITTSBURGH. NAM/GFS SHOW THIS EROSION HAPPENING DURING
THE MORNING HOURS...BUT RAP SHOWS LOW CLOUD DECK REMAINING ALL DAY.
CONSIDERING ALL GUIDANCE WAS TOO OPTIMISTIC YESTERDAY...WILL STICK
WITH PERSISTENCE THROUGH THE DAY AND SHOW ALMOST NO CHANGE IN CLOUD
COVER UNTIL EVENING. THIS IS A LOW CONFIDENCE FORECAST. NEEDLESS TO
SAY...TEMPERATURES TODAY WILL BE ENTIRELY DEPENDENT ON AMOUNT OF
CLOUD COVER. WILL UNDERCUT GUIDANCE IN LOCATIONS WITH CLOUDY SKIES
FORECAST (SINCE MODELS ARE EXPECTING SUN) AND GO NEAR GUIDANCE
ELSEWHERE.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
SURFACE HIGH PRESSURE WILL REMAIN THROUGHOUT THE FORECAST PERIOD.
UPPER LEVEL TROUGH WILL SWING THROUGH ON FRIDAY...BUT WITH VERY
LITTLE MOISTURE...WILL JUST KEEP SOME MID-HIGH LEVEL CLOUDS IN THE
FORECAST. TEMPERATURES WILL SLOWLY RISE...BUT STILL REMAIN SLIGHTLY
COLDER THAN NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
QUIET WEATHER IS FORECAST FOR THE EXTENDED PERIOD AS A BROAD AREA OF
HIGH PRESSURE CONTS TO DOMINATE THE REGION. AN INCREASE IN CLOUDS
IS ANTICIPATED FOR THE START OF THE NEXT WEEK AS AN UPR LOW IS
PROJECTED TO DEVELOP SOUTH OF THE UPPER OHIO VALLEY...AND MOVE TWD
THE EASTERN SEABOARD. TEMPERATURES WERE FORECAST CLOSE TO HPC
GUIDANCE.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
BLEND OF RECENT SURFACE SATELLITE AND UPPER AIR DATA SHOW THAT
REMAINING COLD POOL STRATOCUMULUS ACROSS THE UPPER OHIO VALLEY
WILL BE SLOW TO ERODE FROM SOUTH TO NORTH OVERNIGHT INTO DAYTIME
WEDNESDAY. MOST CEILINGS HAVE BEEN IN VFR RANGE EXCEPT FOR MVFR AT KFKL
AND KDUJ.
EDGE OF STRATOCUMULUS APPEARS CORRELATED WITH H8 -8C CIRCULAR ISOTHERM.
USED THIS COLD POOL IDEA COUPLED WITH NAM MODEL PROFILES AND GFS
LAMP TO PROJECT WHEN CLEARING WILL REACH REMAINING TAF SITES.
CLEARING COULD BE AS EARLY AS 08Z-10Z FOR PLACES LIKE KMGW AND
KPIT...BUT IT MAY NOT BE UNTIL 20Z-22Z FOR KFKL AND KDUJ.
SURFACE WINDS WILL BE FROM THE NORTHEAST AT ABOUT 5 KTS INTO THIS
AFTERNOON.
.OUTLOOK.../THURSDAY THROUGH SUNDAY/...
EXPECT PREVALENT VFR THIS PERIOD DUE TO CONTINUED HIGH PRESSURE
SUBSIDENCE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1105 PM CST TUE NOV 13 2012
.SHORT TERM...THROUGH FRIDAY
241 PM CST TUE NOV 13 2012
MAIN FORECAST CONCERN REMAINS ON CLOUDS AND TEMPERATURES...ALONG
WITH SMALL PRECIPITATION POTENTIAL...WITH THE GENERALLY QUIET
WEATHER PATTERN IN PLACE NOW.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHTS SHOWED
NEARLY ZONAL FLOW ACROSS THE U.S....WITH A PERTURBATION IN THE FLOW
OVER WESTERN PORTIONS OF NEBRASKA AND KANSAS ASSOCIATED WITH A
SHORTWAVE TROUGH. ANOTHER WEAKER SHORTWAVE WAS NOTED OVER NORTH
DAKOTA. THE ZONAL FLOW HAS HELPED TO SPREAD WARMER AIR INTO THE
FORECAST AREA...REFLECTED BY THE 12Z MPX SOUNDING 850MB TEMP WHICH
CLIMBED FROM -13C AT 00Z TO -6C AT 12Z. EVEN WARMER AIR WAS PRESENT
TO THE WEST AT BIS AND ABR WHICH WERE AROUND -1C. THE COMBINATION OF
THIS WARMER AIR ALOFT...FULL SUNSHINE FOR MUCH OF THE DAY...AND DRY
AIR SHOWN TOO ON THE 12Z MPX SOUNDING HAS HELPED TEMPERATURES
REBOUND INTO THE 30S AFTER A CHILLY DAY YESTERDAY. SATELLITE IMAGERY
AND SURFACE OBS SHOWED A MASS OF MID AND HIGH CLOUDS SPREADING EAST
FROM THE DAKOTAS INTO MINNESOTA AND IOWA....DOWNSTREAM OF THE TWO
SHORTWAVES IN THE PLAINS. RADAR IMAGERY EVEN HAS SOME LIGHT DBZ
ECHOES BUT ARE ALL JUST VIRGA DUE TO DRY LOW LEVEL AIR IN PLACE. AT
THE SURFACE...A RIDGE OF HIGH PRESSURE EXTENDED FROM CHICAGO TO
NORTHEAST TEXAS WHILE A SURFACE TROUGH EXTENDED FROM NORTHWEST
ONTARIO TO PIERRE SOUTH DAKOTA.
TONIGHT AND WEDNESDAY...THE WEAK SHORTWAVE OVER NORTH DAKOTA IS
SLATED TO CROSS NORTHERN MINNESOTA AND INTO WESTERN LAKE SUPERIOR BY
12Z WEDNESDAY. GIVEN THE TRACK...BEST UPPER LEVEL PV ADVECTION STAYS
OFF TO OUR NORTH. WE DO HAVE A WARM ADVECTION PATTERN IN PLACE...AND
285-295K ISENTROPIC LIFT PLOTS REFLECT THAT. THE BEST ISENTROPIC
LIFT IS FORECAST TO OCCUR OVER THE FORECAST AREA...BUT THE LOWER
CONDENSATION PRESSURE DEFICITS ARE MOSTLY TO THE NORTH OF THE LIFT.
IF THERE IS ANY JUXTAPOSITION OF THE LIFT AND MOISTURE IS ALONG A
STRETCH BETWEEN RED WING AND TAYLOR COUNTY INTO NORTHEAST WISCONSIN.
MOST 13.12Z MODEL QPF OUTPUT FROM THE NAM...GFS AND ECMWF AS WELL AS
THE 13.15Z SREF MEAN SUGGEST A DRY FORECAST LIKE WE HAD GOING...BUT
THE 13.12Z GEM REGIONAL DOES HAVE LIGHT QPF. THINK THERE IS ENOUGH
SUGGESTION FROM THE MODELS TO HAVE AT LEAST A FLURRY MENTION.
NOTE...THOUGH...THERE IS A WARM LAYER AROUND 2000 FT WHICH COULD
MELT THE FLURRIES INTO SPRINKLES. WET-BULBING IS POSSIBLE...BUT
WOULD NOT BE APPROPRIATE GIVEN THE WEAK LIFT. MAY HAVE TO WATCH FOR
THE SPRINKLES TO FREEZE IF THE SURFACE TEMPERATURE CANNOT CLIMB
ABOVE FREEZING. OUTSIDE OF THIS VERY SMALL PRECIPITATION
POTENTIAL...THE MID AND HIGH CLOUDS SEEN OVER THE DAKOTAS WILL
SPREAD INTO THE AREA TONIGHT...THOUGH...WITH PARTIAL CLEARING
PROGGED TO OCCUR WEST TO EAST DURING THE DAY WEDNESDAY IN THE WAKE
OF THE SHORTWAVE. EXPECT WARMER TEMPERATURES TONIGHT THANKS TO THE
CLOUDS...BUT THE SLIGHTLY LATER ARRIVAL FOR THEM IN WISCONSIN COULD
ALLOW THE TYPICAL COLD SPOTS TO DROP INTO THE MID 20S BEFORE
CLIMBING. MOST OTHER LOCATIONS SHOULD BE NEAR 30 FOR LOWS. WARMER
850MB TEMPS ON WEDNESDAY OF 0-2C COMBINED WITH SOME SUNSHINE SHOULD
YIELD WARMER HIGHS AS WELL. A BLEND OF GUIDANCE SEEMED
REASONABLE...YIELDING MID 40S TO LOW 50S.
WEDNESDAY NIGHT AND THURSDAY...MODELS DEPICT A POTENT SHORTWAVE
TROUGH...CURRENTLY NEAR THE ALASKA/YUKON BORDER...TO DROP DOWN INTO
SASKATCHEWAN AND MANITOBA BY LATE WEDNESDAY. THIS POTENT SHORTWAVE
HEADS UP INTO HUDSON BAY BY LATE THURSDAY. ALTHOUGH THE SHORTWAVE IS
FAR FROM US...THERE IS A WEAKER SOUTHERN EXTENSION OF THE SHORTWAVE
THAT DROPS SOUTHEAST THROUGH THE AREA ON THURSDAY. A WEAK COLD FRONT
LOOKS TO ACCOMPANY THIS SHORTWAVE AT THE SURFACE. SIMILAR TO THE
SHORTWAVE CROSSING NORTH DAKOTA TONIGHT...THERE IS A WARM ADVECTION
PATTERN IN PLACE WITH AN AREA OF MID AND HIGH CLOUDS LIKELY TO
SPREAD ACROSS AHEAD OF THE SHORTWAVE. HOWEVER...ISENTROPIC LIFT
FIELDS THIS TIME DO NOT DEPICT ANY LIFT. IN ADDITION...THE SUB-CLOUD
LAYER REMAINS DRY ACCORDING TO FORECAST SOUNDINGS. THUS...THE DRY
FORECAST REMAINS. ALSO SIMILAR TO TONIGHT...THERE IS A PERIOD OF
PARTIAL CLEARING WEDNESDAY EVENING BEFORE MORE EXTENSIVE CLOUDS COME
IN TO ALLOW TEMPERATURES TO DROP OFF. THUS...SOME SITES IN WESTERN
WISCONSIN AGAIN COULD DIP INTO THE UPPER 20S BEFORE CLIMBING WITH
THE CLOUD INCREASE. LOWER TO MID 30S LOWS SHOULD BE TYPICAL
ELSEWHERE. SOME AFTERNOON SUN ON THURSDAY COMBINED WITH 850MB TEMPS
AGAIN IN THE 0-2C RANGE SHOULD ALLOW FOR HIGHS AGAIN IN THE MID 40S
TO LOW 50S.
THURSDAY NIGHT AND FRIDAY...IN THE WAKE OF THE WEDNESDAY
NIGHT/THURSDAY SHORTWAVE TROUGH...GOOD MODEL AGREEMENT EXISTS OF
STRENGTHENING UPPER AND SURFACE RIDGING BUILDING INTO THE FORECAST
AREA. BY 12Z FRIDAY...MUCH OF THE AREA IS ENCOMPASSED BY A SURFACE
HIGH PRESSURE RIDGE. CLEARING SKIES AND SUBSIDENCE IN THE WAKE OF
THE SHORTWAVE TROUGH...COMBINED WITH DRY AIR NOTED BY PRECIPITABLE
WATER VALUES FALLING TO NEAR ONE THIRD OF AN INCH AND LIGHT WINDS
SHOULD SUPPORT GOOD RADIATIONAL COOLING CONDITIONS. THUS...STAYED
TOWARDS THE LOW END OF GUIDANCE...ESPECIALLY AT THE TYPICAL COLD
SPOTS IN WISCONSIN WHICH COULD DIP INTO THE LOWER 20S. SUNNY SKIES
ON FRIDAY COMBINED WITH DRY AIR AND 850MB TEMPS AROUND 0C SHOULD
LEAD TO A DECENT TEMPERATURE RISE. FOLLOWED A BLEND OF GUIDANCE WITH
HIGHS IN THE 40S WHICH SEEMED REASONABLE...WARMEST OVER THE SOUTHERN
HALF OF THE AREA WHERE SLIGHTLY WARMER 925MB TEMPS EXIST.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
241 PM CST TUE NOV 13 2012
13.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES CONTINUE TO SHOW UPPER
AND SURFACE RIDGING PRETTY MUCH DOMINATING THE AREA THROUGH THE
WEEKEND. THIS IS AHEAD OF A DEEP EAST PACIFIC TROUGH AND SOME WEAK
SUBTROPICAL SHORTWAVES LIFTING OUT OF THE FOUR CORNERS REGION AND
INTO THE NORTHERN PLAINS. THIS SETUP SHOULD KEEP THE AREA DRY WITH
TEMPERATURES GRADUALLY WARMING AS THE SURFACE HIGH FROM FRIDAY JUST
SLOWLY SHIFTS EAST. 850MB TEMPS TOP OUT IN THE 2C EAST TO 4C WEST
RANGE FOR THE WEEKEND WHICH SHOULD RESULT IN HIGHS IN THE MID 40S TO
LOWER 50S. LOWS ARE A LITTLE TRICKY...ESPECIALLY OVER WISCONSIN
WHERE LIGHT WINDS AT NIGHT ASSOCIATED WITH THE SURFACE RIDGE AND
MOSTLY CLEAR SKIES COULD ALLOW FOR QUICK TEMPERATURE DROPS.
FOR EARLY NEXT WEEK....THERE ARE ISSUES BEGINNING TO SHOW UP WITH
THE HANDLING OF THAT DEEP EAST PACIFIC TROUGH. ALL MODELS HAVE THE
TROUGH MOVING INLAND ON MONDAY...BUT THE 13.06Z/12Z GFS DRIVE MUCH
OF IT INTO THE WESTERN U.S. AS A BROAD TROUGH. COMPARE THIS TO THE
13.00Z ECMWF AND 13.12Z CANADIAN WHICH ARE MORE LIFT A LOT UP INTO
CANADA WHICH RESULTS IN A ZONAL FLOW PATTERN FROM THE PACIFIC
NORTHWEST INTO THE NORTHERN PLAINS BY TUESDAY. INTERESTINGLY...THE
NEW 13.12Z ECMWF HAS TRENDED TOWARDS THE GFS SCENARIO. GIVEN THE
ECMWF TREND...HAVE LEANED A LITTLE MORE IN THE GFS/ECMWF DIRECTION.
THIS SCENARIO WILL BRING A LOW PRESSURE SYSTEM AT US FROM THE
PLAINS...WITH VARYING INTENSITY DEPENDING ON HOW MUCH OF THAT UPPER
TROUGH DIGS INTO THE PLAINS. GULF OF MEXICO MOISTURE SHOULD RETURN
AHEAD OF IT...THUS HAVE PRECIPITATION CHANCES IN FOR SOUTH OF I-90
MONDAY NIGHT AND AREA WIDE ON TUESDAY. THE GENERAL WARM AIRMASS
SHOULD KEEP THE TYPE AS RAIN. REGARDING TEMPS...850MB TEMPS HOLD IN
THE 2-4C RANGE...YIELDING HIGHS STILL IN THE MID 40S TO LOW 50S.
LOOKING AHEAD TO THANKSGIVING...WITH THE MODEL TREND ON THE EAST
PACIFIC TROUGH NOW DIGGING INTO THE PLAINS...POTENTIAL EXISTS FOR A
LOW PRESSURE SYSTEM TO BE HANGING AROUND THE AREA WEDNESDAY INTO
THURSDAY. SOME PRECIPITATION THUS LOOKS ON TAP...WITH EITHER RAIN OR
A RAIN AND SNOW MIX THE TYPE. STAY TUNED TO LATER FORECASTS AS
THINGS IRON THEMSELVES OUT.
&&
.AVIATION...
1105 PM CST TUE NOV 13 2012
UPPER LEVEL TROUGH WILL SWING EASTWARD ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY OVERNIGHT. LATEST SATELLITE IMAGERY/SFC OBS DEPICTS A
BAND OF MOSTLY 8-10 KFT CLOUDS ASSOCIATED WITH THE TROUGH. RH FIELDS
AND BUFKIT SOUNDINGS SHOW A RELATIVELY DRY SUB CLOUD LAYER...AND
PCPN WILL HAVE A HARD TIME REACHING THE SFC. SOME INDICATION VIA
LATEST OBS OF A SMATTERING OF LIGHT PCPN THOUGH...BUT TRENDS WOULD
KEEP IT WELL NORTH OF KRST/KLSE...WITH SUPPORT FROM THE LATEST HRRR.
WILL KEEP KRST/KLSE TAFS WITH VFR MID CLOUDS OVERNIGHT. EXPECT THE
MID LEVEL CLOUD DECK TO EXIT EAST BY MID MORNING ON WED...WITH SOME
HIGH/MID LEVEL CLOUDS RETURNING LATER IN THE DAY AHEAD OF WEAK UPPER
LEVEL FEATURE. COULD HAVE SOME AFTERNOON GUSTINESS WED THANKS TO
MIXING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
241 PM CST TUE NOV 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS PUEBLO CO
438 AM MST WED NOV 14 2012
.SHORT TERM...
(TODAY AND TONIGHT)
CURRENTLY...LATEST SATELLITE IMAGERY AND RAP H5 ANALYSIS INDICATE
ZONAL FLOW ALOFT ACROSS THE REGION WITH A SMATTERING OF HIGH CLOUDS
MOVING INTO WESTERN CO. MOSTLY CLEAR SKIES AND LIGHT SFC WINDS HAVE
ALLOWED TEMPS TO DROP A BIT FASTER THIS MORNING AS COMPARED TO THE
LAST...WITH TEMPS AS OF 330 AM IN THE TEENS AND 20S FOR THE
PLAINS...AND 5 TO 15 F FOR THE HIGHER ELEVATIONS.
TODAY AND TONIGHT...WESTERLY FLOW ALOFT CONTINUES...SO MOSTLY SUNNY
SKIES AND DRY CONDITIONS ARE EXPECTED TO CONTINUE. MODELS INDICATE
THAT 850 AND 700 MB TEMPS WARM TODAY...SO LOOK FOR MAX TEMPS AROUND
60 F FOR THE PLAINS AND AROUND 50 F FOR THE HIGH VALLEYS. AN UPPER
WAVE CROSSING THE PAC NW EARLY THIS MORNING IS FORECAST TO CROSS THE
ROCKIES TODAY...PUSHING A COLD FRONT DOWN INTO THE EASTERN HALF OF
CO THIS AFTN AND EVE. THE INITIAL COOL PUSH LOOKS LIKE IT WILL CROSS
THE PALMER DVD SOME TIME BETWEEN 02Z AND 04Z...AND THE NORTHERLY
SHIFT IN SFC WINDS MAY SERVE TO ACTUALLY MIX THE LOWER LEVELS AND
SLOW THE COOL DOWN TONIGHT. THE LOCAL WRF MODEL SHOWS THE TRUE COLD
AIR FILTERING DOWN INTO THE CWA LATE TONIGHT...BETWEEN 10Z AND 12Z.
MOORE
.LONG TERM...
(THURSDAY THROUGH NEXT WEDNESDAY)
COOLER MOST AREAS THURSDAY AS SURFACE HIGH PRESSURE BUILDS SOUTH
THROUGH THE CENTRAL PLAINS. MOST PRONOUNCED COOLING WILL BE OVER
THE EASTERN MOUNTAINS AND PLAINS...WHILE WESTERN MOUNTAINS AND
VALLEYS SEE ONLY A SLIGHT DOWNTURN IN MAX TEMPS. WARMER AIR
RETURNS FRIDAY AS SOUTHWEST FLOW ALOFT INCREASES AHEAD OF WEAK
WAVE SHEARING EASTWARD THROUGH THE GREAT BASIN. MODEL DIFFERENCES
APPEAR LATE FRIDAY INTO SAT AS NAM PRODUCES AT LEAST A FEW INCHES
OF SNOW ALONG THE CONTINENTAL DIVIDE...WHILE GFS/ECMWF SHOW JUST A
FEW -SHSN. CURRENT FORECAST HAS SCATTERED POPS OVER THE HIGHER
PEAKS OF THE CENTRAL AND SOUTHWEST MOUNTAINS THOUGH ONLY MINOR
SNOW ACCUMS...WHICH LOOK FINE FOR NOW. OVER THE WEEKEND...ECMWF
MUCH MORE AGGRESSIVE BRINGING PRECIP TO THE CONTINENTAL DIVIDE
SUNDAY/SUNDAY NIGHT AS IT HAS MUCH MORE MOISTURE MOVING ONSHORE
THAN THE MAINLY DRY GFS. FORECAST HAS JUST SOME ISOLATED POPS OVER
THE PEAKS SUN/MON WHICH MAY NEED TO BE BEEFED UP IF TREND TOWARD
MORE MOISTURE IN THE EUROPEAN CONTINUES. OUTSIDE THE CONTINENTAL
DIVIDE...MILD AND DRY WX SHOULD CONTINUE THROUGH THE WEEKEND.
EARLY NEXT WEEK...BOTH GFS AND ECMWF SHOW UPPER RIDGE BUILDING
OVER THE AREA TUE/WED BEHIND DEPARTING UPPER WAVE...WHICH SHOULD
LEAD TO VERY WARM AND DRY CONDITIONS ACROSS ALL OF SOUTHERN
COLORADO.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HRS OVER
ALL OF SOUTHEAST AND SOUTH CENTRAL COLORADO...INCLUDING THE
THREE MAIN TAF SITES OF KCOS...KPUB AND KALS. LOOK FOR A N-NE
SHIFT IN THE SFC WINDS FOR KCOS BETWEEN 02Z AND 04Z TONIGHT...AND
FOR KPUB BETWEEN 06Z AND 08Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
27/10
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1048 AM EST WED NOV 14 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE ST LAWRENCE VALLEY THIS AFTERNOON DRIFTS
EAST TO THE CANADIAN MARITIME THROUGH THURSDAY. A NEW AREA OF
HIGH PRESSURE APPROACHES FROM THE WEST ON FRIDAY AND BUILDS OVER THE
CANADIAN MARITIMES THROUGH THE WEEKEND. A DEEPENING COASTAL LOW
WELL OFF THE MID ATLANTIC COASTAL IS EXPECTED LATE THIS WEEKEND
INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NNE LOW LEVEL FLOW AS 1038 HPA SFC HIGH PRESSURE IS CENTERED NEAR
MONTREAL. CLOUDS ACROSS LONG ISLAND AT 900 HPA LEVEL BELOW THE
SUBSIDENCE INVERSION WILL DISSIPATE AS DRIER AIR ADVECTS IN AT
THIS LEVEL AS SEEN IN TIME LAGGED RAP DATA. THUS...FCST IS FOR A
SUNNY AFTN FOR ALL LOCATIONS.
MAX TEMPS WERE LOWERED SLIGHTLY TO THE UPPER 40S TO NEAR 50 BASED
ON LATEST TRENDS AND LAMP GUIDANCE AS WINDS GUSTING TO 20 MPH
KEEP THE ATMOSPHERE WELL MIXED. WINDS SUBSIDE QUICKLY WITH LOSS OF
HEATING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TRANQUIL WEATHER CONTINUES TONIGHT INTO THURSDAY AS SURFACE HIGH
DRIFTS EAST TO THE CANADIAN MARITIMES. THE SOUTHERN STREAM SHORTWAVE
MOVES TO THE CAROLINA COAST AS A NORTHERN STREAM SHORTWAVE MOVES
INTO THE GREAT LAKES. ONLY REAL SENSIBLE WX CHANGE IS AN INCREASE
IN HIGH CLOUDS.
LOWS TONIGHT ARE A BLEND OF MAV/MET/ECMWF GUIDANCE. A PERSISTENT
NORTHEASTERLY FLOW WILL KEEP TEMPERATURES SIMILAR TO WEDNESDAYS
HIGHS AND LEANED TOWARD THE COOLER MAV.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
GLOBAL MODELS ARE COMING INTO BETTER AGREEMENT IN TAKING A STORM
SYSTEM OFF THE SOUTHEAST COAST EARLY NEXT WEEK TO THE NORTHEAST...
LARGELY SPARING THE REGION SIGNIFICANT IMPACTS. GUSTY NE WINDS...
LIGHT RAIN ON THE WESTERN PERIPHERY OF THE STORM...AND EPISODES OF
MINOR COASTAL FLOODING ARE ALL POSSIBLE IMPACTS. OF COURSE...THESE
TRENDS CAN CHANGE...ESPECIALLY AS THE SHORT WAVE ENERGY IN THE PAC
NW MOVES ONSHORE TODAY AND GETS BETTER SAMPLED. CLEARLY THOUGH...
OUTSIDE OF HIGH SEAS AND MARGINAL GALE FORCE WIND GUSTS...THE TREND
IS POINTING IN A POSITIVE DIRECTION.
BEFORE THEN...HIGH PRESSURE WILL LARGELY BE IN CONTROL AT THE
SURFACE WITH A PROGRESSIVE UPPER FLOW ACROSS THE NORTHERN HALF OF
THE COUNTRY. HEIGHTS BUILD OVER THE WEEKEND AS SURFACE HIGH PRESSURE
STRENGTHENS EAST OF THE GREAT LAKES. A FAST MOVING UPPER TROUGH AND
DYING COLD FRONT PROGRESS ACROSS THE EAST...LEAVING BEHIND SHORT
WAVE ENERGY AT THE BASE OF THE UPPER TROF ACROSS THE TN VLY AND SE.
THE GFS CONTINUES TO BE FARTHER NORTH THAN THE ECMWF WITH THIS
FEATURE...BUT CLEARLY HAS TRENDED SOUTH THE LAST 24H WITH BOTH THE
SHORT WAVE ENERGY AND OFFSHORE FRONTAL WAVE. THIS LOW NOW RAPIDLY
DEEPENS MON-WED...BUT WELL SOUTH AND EAST OF THE FORECAST AREA.
CLOUDS AND RAIN ON THE NW FRINGE WILL BE MAINTAINED ACROSS THE AREA
THIS FORECAST PACKAGE...BUT IT IS POSSIBLE THAT CONDITIONS COULD
EVEN IMPROVE MORE SO IN SUBSEQUENT MODEL RUNS.
ANY RAIN ASSOCIATED WITH THIS SYSTEM APPEARS TO BE LIGHT AT THIS
TIME WITH ONLY LOW CHANCE POPS SUN INTO TUE.
HIGHS AND LOWS WILL BE CLOSE TO SEASONABLE LEVELS DURING THIS TIME.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
HIGH PRESSURE BUILDS IN TODAY...PRODUCING VFR CONDITIONS.
WINDS GENERALLY NORTH TO NORTH-NORTHEAST AROUND 10 KTS. GUSTS
POSSIBLE BETWEEN 15 AND 18 KTS THROUGH 00Z TONIGHT. GUSTS MAY BE
MORE OCCASIONAL AT INLAND TAF SITES.
BROKEN-OVERCAST CLOUDS AROUND 4KFT OVER LONG ISLAND WILL
DISSIPATE BY AFTN. OTHERWISE...SKC...WITH A FEW HIGH LEVEL CLOUDS
MOVING IN LATE TONIGHT.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: HIGH CONFIDENCE IN WND FCST. WINDS SHOULD
REMAIN LEFT OF 040 MAGNETIC THROUGH THE AFTERNOON.
KLGA FCSTER COMMENTS: HIGH CONFIDENCE IN WND FCST. WINDS SHOULD
REMAIN LEFT OF 040 MAGNETIC THROUGH THE AFTERNOON.
KEWR FCSTER COMMENTS: HIGH CONFIDENCE IN WND FCST.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: HIGH CONFIDENCE IN WND FCST.
KHPN FCSTER COMMENTS: HIGH CONFIDENCE IN WND FCST.
KISP FCSTER COMMENTS: HIGH CONFIDENCE IN WND FCST.
.OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...
.THU-SAT NGT...VFR.
.SUN...MVFR POSSIBLE SUNDAY NIGHT. GUSTY NE WINDS POSSIBLE.
&&
.MARINE...
HIGH PRESSURE FROM SOUTHERN CANADA INTO THE OHIO VALLEY WILL BUILD
TOWARD THE CANADIAN MARITIME THROUGH THURSDAY. WIND GUSTS TO MINIMAL
SMALL CRAFT LEVELS CONTINUE THROUGH THE AFTN...BUT DIMINISH THIS
EVENING AND REMAIN SUCH ON THURSDAY. SEAS ON THE OCEAN WATERS
THOUGH REMAIN NEAR 5 FT...SMALL CRAFT LEVELS...THROUGH
THURSDAY DUE TO SOUTHEAST SWELL GENERATED BY A DISTANT ATLANTIC
LOW.
THUS...SMALL CRAFT ADVISORY IS POSTED THROUGH THURSDAY ON THE OCEAN.
A GRADUALLY STRENGTHENING NE FLOW THROUGH THE WEEKEND WILL RESULT IN
BUILDING SEAS ON THE OCEAN WATERS...WHICH ARE LIKELY TO REMAIN ABOVE
SCA CRITERIA INTO EARLY NEXT WEEK. THE POTENTIAL EXISTS FOR 8 TO
10 FT SEAS BY THE LATE SUN WITH GUSTS APPROACHING GALE FORCE. THE
REMAINING WATERS WILL LIKELY SEE MARGINAL SCA GUSTS BY SUN.
&&
.HYDROLOGY...
DRY WEATHER IS EXPECTED THROUGH SATURDAY NIGHT. NO SIGNIFICANT
PRECIPITATION IS EXPECTED SUNDAY AND MONDAY.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND A LIGHT TO MODERATE NORTHEASTERLY FLOW
WILL RESULT IN ANOTHER ROUND OF VERY MINOR COASTAL FLOODING ON
THURSDAY MORNING. ONLY A HALF A FOOT OR LESS IS NEEDED TO REACH
MINOR BENCHMARKS. A COASTAL STATEMENT IS PLANNED FOR ISSUANCE
LATE THIS AFTN FOR TIDES NEARING THE MINOR BENCHMARK LEVELS.
NOTE THAT THE EVENING TIDE CYCLE IS LOWER BY OVER A FOOT AND THUS
NO COASTAL FLOODING IS FCST FOR THESE CYCLES.
A PROLONGED NE FLOW THROUGH THE UPCOMING WEEKEND MAY LEAD TO
ADDITIONAL EPISODES OF MINOR COASTAL FLOODING...ESPECIALLY IN THOSE
LOCATIONS TYPICALLY MORE VULNERABLE.
&&
.EQUIPMENT...
THE NATIONAL WEATHER SERVICE DOPPLER WEATHER RADAR AT UPTON NEW YORK
/KOKX/ IS UNAVAILABLE. THE RADAR WILL BE OUT OF SERVICE FOR UP TO 2
WEEKS. ADDITIONAL UPDATES WILL BE MADE AS MORE INFORMATION BECOMES
AVAILABLE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THURSDAY FOR ANZ350-353-
355.
&&
$$
SYNOPSIS...MET/DW/JST
NEAR TERM...JST
SHORT TERM...MET/JST
LONG TERM...DW
AVIATION...BC/SEARS/JST
MARINE...MET/DW/JST
HYDROLOGY...MET
TIDES/COASTAL FLOODING...JST
EQUIPMENT...JST
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1004 AM EST WED NOV 14 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRING DRY AND COOL CONDITIONS THROUGH THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
ANOTHER UPDATE TO ADJUST FOR CLOUD TRENDS BUT NO MAJOR CHANGES.
AS STRATOCUMULUS DECK SLOWLY EDGES SOUTHWESTWARD.
THE STRATOCUMULUS DECK HAS STOPPED ERODING AND HAS ACTUALLY BEGAN TO
REBUILD SOUTHWESTWARD. NAM/GFS SHOW THE LAYER BEGINNING TO ERODE
AGAIN THIS MORNING...BUT RAP 925MB RH SHOWS LOW CLOUD DECK
REMAINING ALL DAY. 12Z KPIT SOUNDING INDICATES A STRONG INVERSION
AT 850MB KEEPING MOISTURE LOCKED IN BELOW THIS LAYER. WITH THE
STRENGTH OF THE INVERSION AND CURRENT STRAOTCU DECK IN PLACE...IT
WILL BE DIFFICULT FOR TEMPS TO WARM MUCH TODAY AND ERODE THE
INVERSION. THUS...ANTICIPATE CLOUDY SKIES OVER MOST OF THE
FORECAST AREA INTO AT LEAST THE EARLY AFTERNOON HOURS WHEN WAA
BEGINS TO AID THE EROSION FROM THE SOUTHWEST.
TEMPERATURES THIS AFTERNOON WILL BE ENTIRELY DEPENDENT ON AMOUNT
OF CLOUD COVER. WILL UNDERCUT GUIDANCE IN LOCATIONS WITH CLOUDY
SKIES FORECAST (SINCE MODELS ARE EXPECTING SUN) AND GO NEAR
GUIDANCE ELSEWHERE.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
SURFACE HIGH PRESSURE WILL REMAIN THROUGHOUT THE FORECAST PERIOD.
UPPER LEVEL TROUGH WILL SWING THROUGH ON FRIDAY...BUT WITH VERY
LITTLE MOISTURE...WILL JUST KEEP SOME MID-HIGH LEVEL CLOUDS IN THE
FORECAST. TEMPERATURES WILL SLOWLY RISE...BUT STILL REMAIN SLIGHTLY
COLDER THAN NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
QUIET WEATHER IS FORECAST FOR THE EXTENDED PERIOD AS A BROAD AREA OF
HIGH PRESSURE CONTS TO DOMINATE THE REGION. AN INCREASE IN CLOUDS
IS ANTICIPATED FOR THE START OF THE NEXT WEEK AS AN UPR LOW IS
PROJECTED TO DEVELOP SOUTH OF THE UPPER OHIO VALLEY...AND MOVE TWD
THE EASTERN SEABOARD. TEMPERATURES WERE FORECAST CLOSE TO HPC
GUIDANCE.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
BLEND OF RECENT SURFACE SATELLITE AND UPPER AIR DATA SHOW THAT
REMAINING COLD POOL MVFR STRATOCUMULUS ACROSS THE UPPER OHIO VALLEY
WILL SLOWLY BUILD SOUTHWESTWARD INTO KMGW/KHLG THIS MORNING BEFORE
BEGINNING TO ERODE THIS AFTERNOON.
MVFR CEILINGS WILL PREVAIL EARLY EVERYWHERE EXCEPT KZZV. CEILINGS
WILL SLOWLY LIFT TO VFR THIS MORNING...BUT WILL BE SLOW TO BREAK
UNTIL LATER THIS AFTERNOON. CLEARING IS NOT ANTICIPATED LIKELY NOT
UNTIL AFTER 21Z FOR KFKL AND KDUJ.
SURFACE WINDS WILL BE FROM THE NORTHEAST AT ABOUT 5 KTS INTO THIS
AFTERNOON.
.OUTLOOK.../THURSDAY THROUGH SUNDAY/...
EXPECT PREVALENT VFR THIS PERIOD DUE TO CONTINUED HIGH PRESSURE
SUBSIDENCE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
827 AM EST WED NOV 14 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BRING DRY AND COOL CONDITIONS
THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
A MORNING UPDATE HAS BEEN ISSUED TO ACCOUNT FOR THE LATEST
SATELLITE TRENDS IN SKY COVERAGE AS A STRATOCUMULUS DECK SLOWLY
EDGES SOUTHWESTWARD.
THE STRATOCUMULUS DECK HAS STOPPED ERODING AND HAS ACTUALLY BEGAN TO
REBUILD SOUTHWESTWARD. NAM/GFS SHOW THE LAYER BEGINNING TO ERODE
AGAIN THIS MORNING...BUT RAP 925MB RH SHOWS LOW CLOUD DECK
REMAINING ALL DAY. 12Z KPIT SOUNDING INDICATES A STRONG INVERSION
AT 850MB KEEPING MOISTURE LOCKED IN BELOW THIS LAYER. WITH THE
STRENGTH OF THE INVERSION AND CURRENT STRAOTCU DECK IN PLACE...IT
WILL BE DIFFICULT FOR TEMPS TO WARM MUCH TODAY AND ERODE THE
INVERSION. THUS...ANTICIPATE CLOUDY SKIES OVER MOST OF THE
FORECAST AREA INTO AT LEAST THE EARLY AFTERNOON HOURS WHEN WAA
BEGINS TO AID THE EROSION FROM THE SOUTHWEST.
TEMPERATURES TODAY WILL BE ENTIRELY DEPENDENT ON AMOUNT OF CLOUD
COVER. WILL UNDERCUT GUIDANCE IN LOCATIONS WITH CLOUDY SKIES
FORECAST (SINCE MODELS ARE EXPECTING SUN) AND GO NEAR GUIDANCE
ELSEWHERE.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
SURFACE HIGH PRESSURE WILL REMAIN THROUGHOUT THE FORECAST PERIOD.
UPPER LEVEL TROUGH WILL SWING THROUGH ON FRIDAY...BUT WITH VERY
LITTLE MOISTURE...WILL JUST KEEP SOME MID-HIGH LEVEL CLOUDS IN THE
FORECAST. TEMPERATURES WILL SLOWLY RISE...BUT STILL REMAIN SLIGHTLY
COLDER THAN NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
QUIET WEATHER IS FORECAST FOR THE EXTENDED PERIOD AS A BROAD AREA OF
HIGH PRESSURE CONTS TO DOMINATE THE REGION. AN INCREASE IN CLOUDS
IS ANTICIPATED FOR THE START OF THE NEXT WEEK AS AN UPR LOW IS
PROJECTED TO DEVELOP SOUTH OF THE UPPER OHIO VALLEY...AND MOVE TWD
THE EASTERN SEABOARD. TEMPERATURES WERE FORECAST CLOSE TO HPC
GUIDANCE.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
BLEND OF RECENT SURFACE SATELLITE AND UPPER AIR DATA SHOW THAT
REMAINING COLD POOL MVFR STRATOCUMULUS ACROSS THE UPPER OHIO VALLEY
WILL SLOWLY BUILD SOUTHWESTWARD INTO KMGW/KHLG THIS MORNING BEFORE
BEGINNING TO ERODE THIS AFTERNOON.
MVFR CEILINGS WILL PREVAIL EARLY EVERYWHERE EXCEPT KZZV. CEILINGS
WILL SLOWLY LIFT TO VFR THIS MORNING...BUT WILL BE SLOW TO BREAK
UNTIL LATER THIS AFTERNOON. CLEARING IS NOT ANTICIPATED LIKELY NOT
UNTIL AFTER 21Z FOR KFKL AND KDUJ.
SURFACE WINDS WILL BE FROM THE NORTHEAST AT ABOUT 5 KTS INTO THIS
AFTERNOON.
.OUTLOOK.../THURSDAY THROUGH SUNDAY/...
EXPECT PREVALENT VFR THIS PERIOD DUE TO CONTINUED HIGH PRESSURE
SUBSIDENCE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
613 AM EST WED NOV 14 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BRING DRY AND COOL CONDITIONS
THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
BIGGEST ISSUE IN THE NEAR TERM WILL BE DETERMINING WHEN CLOUDS WILL
GO AWAY.
850MB COLD POOL DID NOT ALLOW MUCH CLEARING YESTERDAY...AND EROSION
PROCESS CONTINUES TO BE VERY SLOW AND MAINLY TO THE SOUTH AND WEST
OF PITTSBURGH. NAM/GFS SHOW THIS EROSION HAPPENING DURING THE
MORNING HOURS...BUT RAP SHOWS LOW CLOUD DECK REMAINING ALL DAY.
CONSIDERING ALL GUIDANCE WAS TOO OPTIMISTIC YESTERDAY...WILL
STICK WITH PERSISTENCE THROUGH THE DAY AND SHOW ALMOST NO CHANGE
IN CLOUD COVER UNTIL EVENING. THIS IS A LOW CONFIDENCE FORECAST.
NEEDLESS TO SAY...TEMPERATURES TODAY WILL BE ENTIRELY DEPENDENT ON
AMOUNT OF CLOUD COVER. WILL UNDERCUT GUIDANCE IN LOCATIONS WITH
CLOUDY SKIES FORECAST (SINCE MODELS ARE EXPECTING SUN) AND GO NEAR
GUIDANCE ELSEWHERE.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
SURFACE HIGH PRESSURE WILL REMAIN THROUGHOUT THE FORECAST PERIOD.
UPPER LEVEL TROUGH WILL SWING THROUGH ON FRIDAY...BUT WITH VERY
LITTLE MOISTURE...WILL JUST KEEP SOME MID-HIGH LEVEL CLOUDS IN THE
FORECAST. TEMPERATURES WILL SLOWLY RISE...BUT STILL REMAIN SLIGHTLY
COLDER THAN NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
QUIET WEATHER IS FORECAST FOR THE EXTENDED PERIOD AS A BROAD AREA OF
HIGH PRESSURE CONTS TO DOMINATE THE REGION. AN INCREASE IN CLOUDS
IS ANTICIPATED FOR THE START OF THE NEXT WEEK AS AN UPR LOW IS
PROJECTED TO DEVELOP SOUTH OF THE UPPER OHIO VALLEY...AND MOVE TWD
THE EASTERN SEABOARD. TEMPERATURES WERE FORECAST CLOSE TO HPC
GUIDANCE.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
BLEND OF RECENT SURFACE SATELLITE AND UPPER AIR DATA SHOW THAT
REMAINING COLD POOL STRATOCUMULUS ACROSS THE UPPER OHIO VALLEY
WILL CONTINUE TO SLOWLY ERODE FROM SOUTHWEST TO NORTHEAST TODAY. MOST
CEILINGS HAVE BEEN IN VFR RANGE EXCEPT FOR MVFR AT KAGC KFKL AND
KDUJ.
EDGE OF STRATOCUMULUS APPEARS CORRELATED WITH H8 -4C CIRCULAR
ISOTHERM. USED THIS COLD POOL IDEA COUPLED WITH NAM MODEL PROFILES
AND GFS LAMP TO PROJECT WHEN CLEARING WILL REACH REMAINING TAF
SITES. CLEARING COULD OCCUR BY 15Z FOR KPIT AREA...BUT BE DELAYED
UNTIL PERHAPS 18Z AT KLBE AND LIKELY NOT UNTIL 20Z-23Z FOR KFKL
AND KDUJ.
SURFACE WINDS WILL BE FROM THE NORTHEAST AT ABOUT 5 KTS INTO THIS
AFTERNOON.
.OUTLOOK.../THURSDAY THROUGH SUNDAY/...
EXPECT PREVALENT VFR THIS PERIOD DUE TO CONTINUED HIGH PRESSURE
SUBSIDENCE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1029 AM MST WED NOV 14 2012
.AVIATION...
KALS...KCOS AND KPUB SHOULD CONTINUE TO EXPERIENCE VFR CONDITIONS
THROUGH TONIGHT. IN ADDITION...A NORTHERLY SURGE IS STILL
PROJECTED TO PUSH ACROSS KCOS BETWEEN 02Z AND 04Z TONIGHT...AND
ACROSS KPUB BETWEEN 06Z AND 08Z TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 438 AM MST WED NOV 14 2012/
SHORT TERM...
(TODAY AND TONIGHT)
CURRENTLY...LATEST SATELLITE IMAGERY AND RAP H5 ANALYSIS INDICATE
ZONAL FLOW ALOFT ACROSS THE REGION WITH A SMATTERING OF HIGH CLOUDS
MOVING INTO WESTERN CO. MOSTLY CLEAR SKIES AND LIGHT SFC WINDS HAVE
ALLOWED TEMPS TO DROP A BIT FASTER THIS MORNING AS COMPARED TO THE
LAST...WITH TEMPS AS OF 330 AM IN THE TEENS AND 20S FOR THE
PLAINS...AND 5 TO 15 F FOR THE HIGHER ELEVATIONS.
TODAY AND TONIGHT...WESTERLY FLOW ALOFT CONTINUES...SO MOSTLY SUNNY
SKIES AND DRY CONDITIONS ARE EXPECTED TO CONTINUE. MODELS INDICATE
THAT 850 AND 700 MB TEMPS WARM TODAY...SO LOOK FOR MAX TEMPS AROUND
60 F FOR THE PLAINS AND AROUND 50 F FOR THE HIGH VALLEYS. AN UPPER
WAVE CROSSING THE PAC NW EARLY THIS MORNING IS FORECAST TO CROSS THE
ROCKIES TODAY...PUSHING A COLD FRONT DOWN INTO THE EASTERN HALF OF
CO THIS AFTN AND EVE. THE INITIAL COOL PUSH LOOKS LIKE IT WILL CROSS
THE PALMER DVD SOME TIME BETWEEN 02Z AND 04Z...AND THE NORTHERLY
SHIFT IN SFC WINDS MAY SERVE TO ACTUALLY MIX THE LOWER LEVELS AND
SLOW THE COOL DOWN TONIGHT. THE LOCAL WRF MODEL SHOWS THE TRUE COLD
AIR FILTERING DOWN INTO THE CWA LATE TONIGHT...BETWEEN 10Z AND 12Z.
27
LONG TERM...
(THURSDAY THROUGH NEXT WEDNESDAY)
COOLER MOST AREAS THURSDAY AS SURFACE HIGH PRESSURE BUILDS SOUTH
THROUGH THE CENTRAL PLAINS. MOST PRONOUNCED COOLING WILL BE OVER
THE EASTERN MOUNTAINS AND PLAINS...WHILE WESTERN MOUNTAINS AND
VALLEYS SEE ONLY A SLIGHT DOWNTURN IN MAX TEMPS. WARMER AIR
RETURNS FRIDAY AS SOUTHWEST FLOW ALOFT INCREASES AHEAD OF WEAK
WAVE SHEARING EASTWARD THROUGH THE GREAT BASIN. MODEL DIFFERENCES
APPEAR LATE FRIDAY INTO SAT AS NAM PRODUCES AT LEAST A FEW INCHES
OF SNOW ALONG THE CONTINENTAL DIVIDE...WHILE GFS/ECMWF SHOW JUST A
FEW -SHSN. CURRENT FORECAST HAS SCATTERED POPS OVER THE HIGHER
PEAKS OF THE CENTRAL AND SOUTHWEST MOUNTAINS THOUGH ONLY MINOR
SNOW ACCUMS...WHICH LOOK FINE FOR NOW. OVER THE WEEKEND...ECMWF
MUCH MORE AGGRESSIVE BRINGING PRECIP TO THE CONTINENTAL DIVIDE
SUNDAY/SUNDAY NIGHT AS IT HAS MUCH MORE MOISTURE MOVING ONSHORE
THAN THE MAINLY DRY GFS. FORECAST HAS JUST SOME ISOLATED POPS OVER
THE PEAKS SUN/MON WHICH MAY NEED TO BE BEEFED UP IF TREND TOWARD
MORE MOISTURE IN THE EUROPEAN CONTINUES. OUTSIDE THE CONTINENTAL
DIVIDE...MILD AND DRY WX SHOULD CONTINUE THROUGH THE WEEKEND.
EARLY NEXT WEEK...BOTH GFS AND ECMWF SHOW UPPER RIDGE BUILDING
OVER THE AREA TUE/WED BEHIND DEPARTING UPPER WAVE...WHICH SHOULD
LEAD TO VERY WARM AND DRY CONDITIONS ACROSS ALL OF SOUTHERN
COLORADO.
AVIATION...
VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HRS OVER
ALL OF SOUTHEAST AND SOUTH CENTRAL COLORADO...INCLUDING THE
THREE MAIN TAF SITES OF KCOS...KPUB AND KALS. LOOK FOR A N-NE
SHIFT IN THE SFC WINDS FOR KCOS BETWEEN 02Z AND 04Z TONIGHT...AND
FOR KPUB BETWEEN 06Z AND 08Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1009 AM MST WED NOV 14 2012
.UPDATE...BULK OF THE WAVE CLOUD HAS MOVED ONTO THE FAR EASTERN
PLAINS WITH HIGH CLOUDS INCREASING FROM THE WEST. MODERATE WEST TO
NORTHWEST FLOW ALOFT OVER AREA...THOUGH WINDS ACROSS MOUNTAINS
AND HIGHER FOOTHILLS HAVE DECREASED WITH LACK OF MOUNTAIN WAVE.
AIRMASS SLIGHTLY WARMER BUT COULD BE OFFSET BY CLOUD COVER.
WEAK DISTURBANCE MOVING ACROSS WYOMING TONIGHT COULD BRING SOME
LIGHT SNOW SHOWERS TO THE NORTHERN MOUNTAINS...BUT ASCENT AND
OROGRAPHICS LOOKS MINIMAL FOR ANY ACCUMULATION. LATEST MODELS SHOW
WEAK FRONT MOVING ACROSS PLAINS DURING THE EVENING...MAIN IMPACT
TO BE A WIND SHIFT WITH PERHAPS MORE CLOUD COVER. OVERALL...
CURRENT FORECASTS LOOKING ON TRACK WITH SOME MINOR ADJUSTMENTS TO
CLOUD CLOVER.
&&
.AVIATION...WILL CONTINUE CURRENT TAF TRENDS FOR THE UPCOMING
ISSUANCE. LOOKING LIKE WINDS ACROSS AREA WANTING TO TREND TOWARD
WESTERLY...THOUGH LATEST RUC AND HRRR STILL SHOWING SOUTH TO
SOUTHEAST. LOOKING LIKE VARIABLE IS THE WAY TO GO AS SPEEDS WILL
REMAIN BELOW 8 KTS. RUC DOES INDICATE A NORTHERLY COMPONENT
AROUND 03Z BEHIND A WEAK FRONT. ANY WIND SHIFT MAY END UP BEING
MASKED WITH THE DEVELOPING DRAINAGE SO WILL HOLD OFF ON INCLUDING
A NORTHERLY COMPONENT IN THE TAFS.
&&
.PREV DISCUSSION... /ISSUED 405 AM MST WED NOV 14 2012/
SHORT TERM...HIGH CLOUDS ARE SPREADING OVER OUR AREA AT THIS
TIME...AND THEY APPEAR TO EXTEND FURTHER SOUTH THAN EARLIER
FORECAST. THERE WAS SUPPOSED TO BE SOME DECREASE LATER TODAY AS
THE WARM ADVECTION ALOFT DIMINISHED...BUT IT NOW LOOKS LIKE THIS
WILL BE LIMITED...PERHAPS STILL PARTLY TO MOSTLY CLOUDY THIS
AFTERNOON. TAIL END OF THE SHORTWAVE MOVING FROM THE NORTHERN
ROCKIES ONTO THE PLAINS WILL BRING A WIND SHIFT TO A MORE
NORTHERLY DIRECTION IN THE EVENING AND THICKER CLOUD COVER. WE
COULD HAVE CLOUDS BRUSHING THE MOUNTAINS ALONG THE NORTHERN BORDER
AGAIN...THOUGH FORCING IS WEAK AND WINDS WILL BE DIMINISHING BY
THAT TIME. CURRENT SLIGHT CHANCES WILL SUFFICE. CLOUDS WILL OFFSET
THE WARMER AIRMASS TODAY...FORECAST OF A FEW DEGREES WARMER STILL
LOOKS GOOD. I DID TRIM THE HIGHS IN AREAS WEST OF THE DIVIDE WHERE
A COLD POOL IN THE VALLEYS WILL PERSIST UNDER THE CLOUD DECK.
LONG TERM...WEST-NORTHWESTERLY FLOW ALOFT IS PROGGED FOR THE CWA
THURSDAY INTO THURSDAY NIGHT. BY FRIDAY...AN UPPER RIDGE AXIS
MOVES ACROSS...WITH THE FLOW ALOFT BECOMING ZONAL. BY LATER FRIDAY
IT BECOMES WEST-SOUTHWESTERLY...THEN A WEAK UPPER TROUGH IS
PROGGED ACROSS THE FORECAST AREA FRIDAY NIGHT. THE SYNOPTIC SCALE
ENERGY IS BENIGN THURSDAY INTO FRIDAY MORNING...THEN WEAK UPWARD
VERTICAL VELOCITY IS PROGGED THE REST OF FRIDAY INTO FRIDAY
EVENING. DOWNWARD MOTION FOLLOWS BY SATURDAY MORNING. THE LOW
LEVEL WIND FIELDS SHOW WEAK UPSLOPE FLOW ON THURSDAY...WITH A MORE
NORMAL WIND PATTERN THURSDAY NIGHT INTO FRIDAY. THE EASTERN HALF
OF THE PLAINS HAS FAILRY STRONG SOUTHERLY FLOW ON FRIDAY...WITH
DOWNSLOPING NORTHWESTERLIES FRIDAY NIGHT FOR ALL AREAS AS THE
UPPER TROUGH MOVES OVER. FOR MOISTURE...THURSDAY AND THURSDAY
NIGHT ARE PRETTY DRY...JUST A TAD IN THE MID AND UPPER LEVELS.
UPPER LEVEL MOISTURE INCREASES SOMEWHAT ON FRIDAY...WITH IT
LOWERS AND DEEPENS SOMEWHAT IN THE MOUNTAINS FRIDAY NIGHT. THE
QPF FIELDS SHOW A TAD OF MEASURABLE SNOWFALL FRIDAY NIGHT WEST OF
THE DIVIDE IN THE HIGH MOUNTAINS. FOR POPS WILL LEAVE IN THE
"SLIGHT CHANCE"S OF SNOW IN THE MOUNTAINS FRIDAY NIGHT...WITH THE
MOISTURE IN MIND. OROGRAPHIC ENHANCEMENT LOOKS WEAK AT THIS TIME.
FOR TEMPERATURES...THURSDAY`S HIGHS ARE 2-4 C COOLER THAN TODAY`S.
FRIDAY`S READINGS WARM UP 4-6 C OVER THURSDAY`S. FOR THE LATER
DAYS...SATURDAY THROUGH TUESDAY...MODELS SHOW WEST-SOUTHWESTERLY
FLOW ALOFT SATURDAY INTO SUNDAY. BY SUNDAY NIGHT...THE ECMWF HAS A
WEAK UPPER TROUGH TO MOVE ACROSS COLORADO. THE GFS SHOWS A WEAK
TROUGH LATE MONDAY INTO MONDAY NIGHT. EITHER WAY...MOISTURE IS
LIMITED...SO IS THE SYNOPTIC SCALE ENERGY. TEMPERATURES LOOK TO
STAY ABOVE NORMAL ALL FOUR DAYS.
AVIATION...VFR CONDITIONS AND LIGHT WINDS TODAY. TENDENCY WILL BE
TOWARD SE TO E WINDS THIS AFTERNOON. SOME UNCERTAINTY ABOUT A
POSSIBLE PERIOD OF NORTHERLY WINDS BEHIND A WEAK FRONT THIS
EVENING...AT THIS TIME IT LOOKS LIKE THIS MAY BE MASKED BY TERRAIN
EFFECTS AND THE NORMAL SOUTHERLY DRAINAGE SO THE WIND SHIFT MAY
NOT OCCUR IN THE DENVER AREA. IN ANY EVENT...SPEEDS SHOULD BE LESS
THAN 12 KNOTS THIS EVENING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RJK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1245 PM EST WED NOV 14 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE ST LAWRENCE VALLEY THIS AFTERNOON DRIFTS
EAST TO THE CANADIAN MARITIME THROUGH THURSDAY. A NEW AREA OF
HIGH PRESSURE APPROACHES FROM THE WEST ON FRIDAY AND BUILDS OVER THE
CANADIAN MARITIMES THROUGH THE WEEKEND. A DEEPENING COASTAL LOW
WELL OFF THE MID ATLANTIC COASTAL IS EXPECTED LATE THIS WEEKEND
INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NNE LOW LEVEL FLOW AS 1038 HPA SFC HIGH PRESSURE IS CENTERED NEAR
MONTREAL. CLOUDS ACROSS LONG ISLAND AND NYC AT 900 HPA LEVEL BELOW
THE SUBSIDENCE INVERSION WILL CONTINUE TO DISSIPATE AS DRIER AIR
ADVECTS IN AT THIS LEVEL AS SEEN IN TIME LAGGED RAP DATA.
THUS...FCST IS FOR A SUNNY AFTN FOR ALL LOCATIONS.
MAX TEMPS IN THE UPPER 40S TO NEAR 50 BASED ON LATEST TRENDS AND
LAMP GUIDANCE AS WINDS GUSTING TO 15-20 MPH KEEP THE ATMOSPHERE WELL
MIXED. WINDS SUBSIDE QUICKLY WITH LOSS OF HEATING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TRANQUIL WEATHER CONTINUES TONIGHT INTO THURSDAY AS SURFACE HIGH
DRIFTS EAST TO THE CANADIAN MARITIMES. THE SOUTHERN STREAM SHORTWAVE
MOVES TO THE CAROLINA COAST AS A NORTHERN STREAM SHORTWAVE MOVES
INTO THE GREAT LAKES. ONLY REAL SENSIBLE WX CHANGE IS AN INCREASE
IN HIGH CLOUDS ON THURSDAY WHICH HAS BEEN ADDED TO FCST.
LOWS TONIGHT ARE A BLEND OF MAV/MET GUIDANCE. A PERSISTENT NORTHEASTERLY
FLOW WILL KEEP TEMPERATURES SIMILAR TO WEDNESDAYS HIGHS AND
CONTINUE TO LEAN TOWARDS THE COOLER MAV.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
GLOBAL MODELS ARE COMING INTO BETTER AGREEMENT IN TAKING A STORM
SYSTEM OFF THE SOUTHEAST COAST EARLY NEXT WEEK TO THE NORTHEAST...
LARGELY SPARING THE REGION SIGNIFICANT IMPACTS. GUSTY NE WINDS...
LIGHT RAIN ON THE WESTERN PERIPHERY OF THE STORM...AND EPISODES OF
MINOR COASTAL FLOODING ARE ALL POSSIBLE IMPACTS. OF COURSE...THESE
TRENDS CAN CHANGE...ESPECIALLY AS THE SHORT WAVE ENERGY IN THE PAC
NW MOVES ONSHORE TODAY AND GETS BETTER SAMPLED. CLEARLY THOUGH...
OUTSIDE OF HIGH SEAS AND MARGINAL GALE FORCE WIND GUSTS...THE TREND
IS POINTING IN A POSITIVE DIRECTION.
BEFORE THEN...HIGH PRESSURE WILL LARGELY BE IN CONTROL AT THE
SURFACE WITH A PROGRESSIVE UPPER FLOW ACROSS THE NORTHERN HALF OF
THE COUNTRY. HEIGHTS BUILD OVER THE WEEKEND AS SURFACE HIGH PRESSURE
STRENGTHENS EAST OF THE GREAT LAKES. A FAST MOVING UPPER TROUGH AND
DYING COLD FRONT PROGRESS ACROSS THE EAST...LEAVING BEHIND SHORT
WAVE ENERGY AT THE BASE OF THE UPPER TROF ACROSS THE TN VLY AND SE.
THE GFS CONTINUES TO BE FARTHER NORTH THAN THE ECMWF WITH THIS
FEATURE...BUT CLEARLY HAS TRENDED SOUTH THE LAST 24H WITH BOTH THE
SHORT WAVE ENERGY AND OFFSHORE FRONTAL WAVE. THIS LOW NOW RAPIDLY
DEEPENS MON-WED...BUT WELL SOUTH AND EAST OF THE FORECAST AREA.
CLOUDS AND RAIN ON THE NW FRINGE WILL BE MAINTAINED ACROSS THE AREA
THIS FORECAST PACKAGE...BUT IT IS POSSIBLE THAT CONDITIONS COULD
EVEN IMPROVE MORE SO IN SUBSEQUENT MODEL RUNS.
ANY RAIN ASSOCIATED WITH THIS SYSTEM APPEARS TO BE LIGHT AT THIS
TIME WITH ONLY LOW CHANCE POPS SUN INTO TUE.
HIGHS AND LOWS WILL BE CLOSE TO SEASONABLE LEVELS DURING THIS TIME.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
HIGH PRESSURE NORTHWEST OF THE REGION WILL PRODUCE VFR CONDITIONS.
WINDS GENERALLY NORTH TO NORTH-NORTHEAST AROUND 10 KTS.
OCCASIONAL GUSTS POSSIBLE BETWEEN 15 AND 18 KTS THROUGH 00Z
TONIGHT.
JUST SOME HIGH LEVEL CLOUDS MOVING IN LATE TONIGHT...WHICH MAY
BECOME BROKEN DURING THE DAY TOMORROW.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: HIGH CONFIDENCE IN WIND FCST. WINDS SHOULD
REMAIN LEFT OF 040 MAGNETIC THROUGH THE AFTERNOON.
KLGA FCSTER COMMENTS: HIGH CONFIDENCE IN WIND FCST. WINDS SHOULD
REMAIN LEFT OF 040 MAGNETIC THROUGH THE AFTERNOON.
KEWR FCSTER COMMENTS: HIGH CONFIDENCE IN WIND FCST.
KTEB FCSTER COMMENTS: HIGH CONFIDENCE IN WIND FCST.
KHPN FCSTER COMMENTS: HIGH CONFIDENCE IN WIND FCST.
KISP FCSTER COMMENTS: HIGH CONFIDENCE IN WIND FCST.
.OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
.THU-SUN...VFR.
.SUN NIGHT-MONDAY...MVFR POSSIBLE. GUSTY NE WINDS POSSIBLE.
&&
.MARINE...
HIGH PRESSURE FROM SOUTHERN CANADA INTO THE OHIO VALLEY WILL BUILD
TOWARD THE CANADIAN MARITIME THROUGH THURSDAY. WIND GUSTS TO MINIMAL
SMALL CRAFT LEVELS CONTINUE THROUGH THE AFTN...BUT DIMINISH THIS
EVENING AND REMAIN SUCH ON THURSDAY. SEAS ON THE OCEAN WATERS
THOUGH REMAIN NEAR 5 FT...SMALL CRAFT LEVELS...THROUGH
THURSDAY DUE TO SOUTHEAST SWELL GENERATED BY A DISTANT ATLANTIC
LOW.
THUS...SMALL CRAFT ADVISORY IS POSTED THROUGH THURSDAY ON THE OCEAN.
A GRADUALLY STRENGTHENING NE FLOW THROUGH THE WEEKEND WILL RESULT IN
BUILDING SEAS ON THE OCEAN WATERS...WHICH ARE LIKELY TO REMAIN ABOVE
SCA CRITERIA INTO EARLY NEXT WEEK. THE POTENTIAL EXISTS FOR 8 TO
10 FT SEAS BY THE LATE SUN WITH GUSTS APPROACHING GALE FORCE. THE
REMAINING WATERS WILL LIKELY SEE MARGINAL SCA GUSTS BY SUN.
&&
.HYDROLOGY...
DRY WEATHER IS EXPECTED THROUGH SATURDAY NIGHT. NO SIGNIFICANT
PRECIPITATION IS EXPECTED SUNDAY AND MONDAY.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND A LIGHT TO MODERATE NORTHEASTERLY FLOW
WILL RESULT IN ANOTHER ROUND OF VERY MINOR COASTAL FLOODING ON
THURSDAY MORNING. ONLY A HALF A FOOT OR LESS IS NEEDED TO REACH
MINOR BENCHMARKS. A COASTAL STATEMENT IS PLANNED FOR ISSUANCE
LATE THIS AFTN FOR TIDES NEARING THE MINOR BENCHMARK LEVELS
THURSDAY MORNING.
NOTE THAT THE EVENING TIDE CYCLE IS LOWER BY OVER A FOOT AND THUS
NO COASTAL FLOODING IS FCST FOR THESE CYCLES.
A PROLONGED NE FLOW THROUGH THE UPCOMING WEEKEND MAY LEAD TO
ADDITIONAL EPISODES OF MINOR COASTAL FLOODING...ESPECIALLY IN THOSE
LOCATIONS TYPICALLY MORE VULNERABLE.
&&
.EQUIPMENT...
THE NATIONAL WEATHER SERVICE DOPPLER WEATHER RADAR AT UPTON NEW YORK
/KOKX/ IS UNAVAILABLE. THE RADAR WILL BE OUT OF SERVICE FOR UP TO 2
WEEKS. ADDITIONAL UPDATES WILL BE MADE AS MORE INFORMATION BECOMES
AVAILABLE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THURSDAY FOR ANZ350-353-
355.
&&
$$
SYNOPSIS...MET/DW
NEAR TERM...MET
SHORT TERM...MET
LONG TERM...DW
AVIATION...BC
MARINE...MET/DW
HYDROLOGY...MET
TIDES/COASTAL FLOODING...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS TOPEKA KS
328 PM CST WED NOV 14 2012
.DISCUSSION...
SHORT TERM FORECAST - TONIGHT AND THURSDAY...
21Z RAP SURFACE ANALYSIS INDICATES A WEAK AREA OF BROAD LOW PRESSURE
OVER THE HIGH PLAINS WITH ANOTHER BROAD AREA OF HIGH PRESSURE OVER
THE SE CONUS. BETWEEN THESE TWO FEATURES A WEAK SURFACE PRESSURE
GRADIENT HAS CAUSED SOUTHERLY WINDS AROUND 5 TO 10 MPH TO PERSIST
THROUGHOUT THE DAY. EXPECT THESE SOUTHERLY WINDS TO PERSIST
OVERNIGHT AROUND 5 MPH...WHICH MAY HELP TO KEEP TEMPS SLIGHTLY
WARMER THAN TUESDAY NIGHT AS LOWS ARE EXPECTED TO STAY IN THE LOWER
TO MID 30S. THURSDAY WILL LIKELY BE A REPEAT OF WEDNESDAY WITH SUNNY
SKIES...HOWEVER WINDS MAY BE SLIGHTLY MORE OUT OF THE WEST THAN
WEDNESDAY AND THIS MAY ALLOW FOR TEMPS TO RISE SLIGHTLY HIGHER THAN
WEDNESDAY...WITH HIGHS EXPECTED TO BE IN THE LOWER 60S.
JL
LONG TERM - THURSDAY NIGHT THROUGH WEDNESDAY...
THE LONG TERM PERIOD WILL BE ON THE QUIET SIDE WITH A RATHER DRY
AIRMASS REMAINING ENTRENCHED ACROSS THE PLAINS. THE FLOW PATTERN
ALOFT WILL SEE A FEW DISTURBANCES MOVE THROUGH THE REGION. THE
FIRST MOVES THROUGH ON THURSDAY NIGHT BUT IS A FAST MOVING SYSTEM
THROUGH A MOISTURE STARVED REGION...WHICH WILL RESULT IN A DRY
FRONTAL PASSAGE AND A SLIGHTLY COOLER AIRMASS FOR FRIDAY AND
SATURDAY. THE UPPER FLOW WILL BECOME MORE SOUTHWESTERLY FOR THE
WEEKEND WITH WARM ADVECTION ALOFT AND A WEAK DISTURBANCE SCHEDULED
TO AFFECT THE AREA BY SUNDAY EVENING. TEMPERATURES WILL BE ABOVE
NORMAL INTO SUNDAY NIGHT...AND CURRENT INDICATIONS SUGGEST THAT
SUFFICIENT MOISTENING WILL OCCUR IN ADVANCE OF THIS DISTURBANCE TO
PROVIDE A CHANCE FOR SCATTERED SHOWERS ON SUNDAY NIGHT AND EARLY
MONDAY IN A ZONE OF DEEP ASCENT IMMEDIATELY IN ADVANCE OF THE
SHORT WAVE. A SLIGHTLY DEEPER TROUGH WILL QUICKLY FOLLOW AND MERGE
WITH THE INITIAL SHORT WAVE TROUGH BY MONDAY NIGHT. WHILE THIS
WILL BE A DEEPER SYSTEM...ANY PRECIPITATION WILL LIKELY HOLD OFF
UNTIL THE TWO WAVES MERGE AND STRENGTHEN...EAST OF THE FORECAST
AREA. SO HAVE A DRY FORECAST BEYOND MONDAY WITH CONTINUED ABOVE
NORMAL TEMPERATURES AS UPPER RIDGING AND WARM ADVECTION BUILD INTO
THE REGION THROUGH MID WEEK.
BARJENBRUCH
&&
.AVIATION...
VFR CONDITIONS EXPECTED THROUGH NEXT 24 HOURS.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$