Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/08/13
AREA FORECAST DISCUSSION
NWS PUEBLO CO
318 PM MST WED NOV 6 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 249 PM MST WED NOV 6 2013
CURRENTLY...
BRISK NORTHWEST FLOW IS PRODUCING WIND GUSTS TO NEAR 40KTS
ACROSS THE MOUNTAINS AND I-25 CORRIDOR OF SOUTHEASTERN COLORADO THIS
AFTERNOON. WEAK INSTABILITY ALSO PRODUCED SOME VERY LIGHT SNOW
SHOWERS AT KLXV AROUND 19Z/20Z. ANY REMAINING SNOW SHOWERS AND
CLOUDS WILL DISSIPATE BY LATE THIS AFTERNOON.
TONIGHT...
NORTHWEST FLOW WILL CONTINUE TO PRODUCE CLEAR SKIES AND DRY
CONDITIONS ACROSS THE AREA. THE BIGGEST FORECAST CHALLENGE ARE LOW
TEMPERATURES AND WINDS ACROSS THE MOUNTAINS OVERNIGHT. LATEST HRRR
AND RAP RUNS KEEP WINDS AT 10-15KTS THROUGH EARLY THURSDAY MORNING
AROUND THE LEADVILLE AREA AND THE PIKE`S PEAK REGION. I HAVE
INCREASED LOW TEMPERATURES IN THESE AREAS TO MATCH EC/MET/MAV
GUIDANCE. VALLEY AND LOCATIONS ON THE PLAINS WILL HAVE A CLEAR/COLD
NIGHT.
THURSDAY...
AFTER A COLD START TEMPERATURES WILL WARM NICELY UNDER SUNNY SKIES.
700MB TEMPERATURES WARM UP TO 2-4C PER THE 18Z NAM12. UPPER LEVEL
FLOW WILL BE COME MORE ZONAL/WESTERLY THROUGHOUT THE DAY. BUFKIT
SOUNDINGS SHOW ALL LOCATIONS MIXING FAIRLY WELL...WITH WESTERLY
WINDS IN THE MOUNTAINS...AND SOUTHERLY WINDS ACROSS THE PLAINS. -PC
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 249 PM MST WED NOV 6 2013
THURSDAY NIGHT THROUGH SATURDAY...AN UPPER DISTURBANCE WILL TRACK
ACROSS THE NORTHERN ROCKIES ON FRI...TIGHTENING THE PRESSURE
GRADIENT ACROSS COLORADO AND PRODUCING GUSTY CONDITIONS FOR THE
MTS AND AT TIMES FOR THE E PLAINS. THE WESTERLY DOWNSLOPE FLOW
WILL HELP TEMPS WARM NICELY...WITH FORECAST MAX TEMPS IN THE UPPER
60S AND 70S FOR THE PLAINS...50S AND 60S FOR THE HIGH VALLEYS. AS
THE DISTURBANCE CONTINUE EAST THROUGH THE NIGHT...IT WILL PUSH
COLD AIR DOWN ACROSS WY AND INTO CO. A DRY COLD FRONT IS EXPECTED
TO CROSS THE PALMER DVD AND MOVE INTO THE CWA LATE FRI EVE...WITH
MUCH COOLER TEMPS THEN EXPECTED FOR SAT. AT THIS TIME...NO PCPN IS
EXPECTED.
SUNDAY THROUGH TUESDAY...ZONAL FLOW ALOFT WITH WEAK RIDGING WILL
CONTINUE TO BE THE CASE THROUGH THE FIRST HALF OF THE NEXT WORK
WEEK. DRY CONDITIONS WILL PREVAIL...WITH MAX TEMPS EACH DAY IN THE
50S TO LOWER 60S WHICH WILL BE RIGHT AT SEASONAL NORMS.
WEDNESDAY...GFS AND EC MODELS INDICATE THAT THE UPPER RIDGE WILL
BREAK DOWN STARTING LATE TUE NIGHT...WITH AN UPPER TROUGH CROSSING
MT AND WY ON WED AND BRINGING THE CHANCE FOR SOME PCPN TO THE CWA ON
WED. BEING SO FAR OUT...CONFIDENCE IS LOW ON THE TIMING...BUT
DECIDED TO DROP MAX TEMPS ABOUT 5 F AND INTRODUCED SOME ISOLATED
POPS. MOORE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 249 PM MST WED NOV 6 2013
VFR CONDITIONS ARE EXPECTED NEXT 24 HOURS AT ALL 3 TAF
SITES..KALS...KCOS...AND KPUB. WINDS AT KCOS AND KPUB SHOULD CALM
DOWN BY 02Z TONIGHT AND WILL BE LIGHT AND VARIABLE THROUGH 18Z
WEDNESDAY. -PC
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PJC
LONG TERM...MOORE
AVIATION...PJC
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1001 AM MST WED NOV 6 2013
.UPDATE...
&&
.SHORT TERM...FAIRLY STRONG NORTHWEST FLOW ALOFT CURRENTLY OVER
THE STATE WITH UPPER LEVEL JET NOSING INTO WYOMING. SATELLITE AND
WEB CAMS SHOWING FAIRLY GOOD MOISTURE WEST OF THE CONTINENTAL
DIVIDE. RADAR AND CAMS INDICATING SNOW SHOWERS ALONG THE
DIVIDE...MAINLY WEST FACING SLOPES...AND OVER THE GORE AND PARK
RANGES OF WESTERN JACKSON COUNTY. SHOWERS BEING GENERATED BY THE
COMBINATION OF OROGRAPHICS AND ASCENT. CROSS SECTIONS SHOW THE
MOISTURE CONTINUING THROUGH THE MORNING WITH SOME DECREASE DURING
THE AFTERNOON. ALSO ASCENT WEAKENS AND BECOMES SUBSIDENT AS
JET MAX MOVES OUT OF WYOMING. THUS SHOULD SEE SOME DECREASE IN THE
SHOWERS. LATEST RAP GENERATES SOME LIGHT SHOWERS AND QPF ACROSS
FAR NORTHEAST PLAINS THIS AFTERNOON...MAY BE A BIT OVERDONE GIVEN
THE AMOUNT OF DESCENT EXPECTED. WINDS HAVE BEEN A BIT GUSTY IN
AND NEAR FOOTHILLS AS GRADIENT BETWEEN UPPER RIDGE OVER THE GREAT
BASIN AND TROUGH ACROSS PLAINS INCREASES A BIT. 1500 METER
GRADIENT FROM GJT TO DEN HAS BEEN STEADILY INCREASING...CURRENTLY
AT 7.57 MB. BY AFTERNOON...COMBINATION OF MIXING AND INCREASING
SUBSIDENCE SHOULD HELP INCREASE WINDS ACROSS THE AREA. DID UPDATE
FOR MORE CLOUDS AND SHOWERS ACROSS THE MOUNTAINS THIS
MORNING...MAINLY ALONG THE DIVIDE. ALSO ADDED SOME LIGHT
ACCUMULATION. ALSO ADDED A BIT MORE WIND IN AND NEAR THE FOOTHILLS
BASED ON CURRENT TRENDS. REST OF FORECAST LOOK OKAY FOR NOW.
.AVIATION...WINDS BEGINNING TO MIX TO THE SURFACE...AS SHOWING BY
RECENT GUSTY WINDS AT KBJC. DID UPDATE FOR SOME GUSTS
THERE...THOUGH WINDS HAVE RECENTLY DECREASED. BY 19Z WINDS TO
BECOME MORE NORTHWEST AS MIXING CONTINUES. CURRENT GUSTS TO AROUND
25 KTS STILL LOOKING REASONABLE FOR KDEN AND KAPA...WITH GUSTS TO
30 KTS AT KBJC. WILL CONTINUE TREND OF CURRENT TAFS.
&&
.PREV DISCUSSION... /ISSUED 338 AM MST WED NOV 6 2013/
SHORT TERM...TODAY AND TONIGHT...NORTHWEST FLOW ALOFT WILL
PREVAIL. SHALLOW MOISTURE EMBEDDED IN THIS FLOW WILL PRODUCE
CLOUDS AND SCATTERED TO ISOLATED SNOW SHOWERS OVER THE NORTH
CENTRAL MOUNTAINS OF COLORADO. DOWNSLOPE WINDS WILL DRY THE AIR ON
THE EAST SIDE OF THE MOUNTAINS. WINDS ARE GUSTY IN SPOTS THIS
MORNING...LIKELY DUE TO MOUNTAIN WAVES. THE GUSTY WINDS WILL MIX
DOWN THIS AFTERNOON ACROSS THE FRONT RANGE AND EASTERN PLAINS.
THESE DOWNSLOPE WINDS WILL HELP INCREASE TEMPERATURES WITH HIGHS
AROUND 50 DEGREES OVER NORTHEAST COLORADO.
THE SNOW SHOWERS OVER THE MOUNTAINS WILL END THIS EVENING AS DRIER
MOVES INTO THE AREA. SKIES WILL BE MOSTLY CLEAR TONIGHT AND ALLOW
FOR GOOD RADIATIONAL COOLINGS. LOWS WILL FALL BELOW FREEZING
AGAIN FOR MOST LOCATIONS WHERE THE WIND IS NOT BLOWING.
LONG TERM...SWIFT NEARLY ZONAL JET FLOW OVER THE NORTHERN TIER
STATES THROUGH THE START OF NEXT WEEK MEANS TRANQUIL MID-AUTUMN
WEATHER CONDITIONS FOR THE FORECAST AREA. SEE LITTLE TO NO CHANCE
OF PRECIP AND NEAR TO ABOVE AVERAGE TEMPERATURES DURING THE
FRIDAY-TUESDAY TIME PERIOD. ONLY DISRUPTION IN THE TRANQUIL
PICTURE OCCURS FRIDAY WHEN THE PASSAGE OF A SHORTWAVE TROUGH
CAUSES THE NOSE OF A 100+ KNOT JET TO DIP SOUTH OVER SOUTHERN
WYOMING FRIDAY MORNING. NAM DERIVED CROSS SECTIONS INDICATE A
STEADY INCREASE IN THE CROSS MOUNTAIN WIND COMPONENT THURSDAY
NIGHT WITH A 73KT SPEED MAXIMA ABOVE THE CREST OF THE FRONT RANGE
(ABOUT 650 MBS) AS OF 15Z/FRIDAY. MODEL SHOWS SOME OF THIS
MOUNTAIN TOP MOMENTUM MIGRATING DOWN THE LEESIDE OF THE FRONT
RANGE FRIDAY MORNING/AFTERNOON WITH 30-40KTS DOWN TO AROUND THE
8500 FT LEVEL. BELOW THAT...WIND SPEEDS NO WHERE AS STRONG
ACCORDING TO BOTH THE NAM AND GFS. NOT READY TO ISSUE ANY HIGH
WIND HIGHLIGHTS AS MODELS CONTINUE TO TREND THIS SHORTWAVE TROUGH
AND JET STREAM A BIT FARTHER NORTH WITH EACH RUN CYCLE. FOR NOW
WILL CONTINUE TO INDICATE STRONG/GUSTY WESTERLY/DOWNSLOPE WINDS IN
THE THURSDAY NIGHT/FRIDAY FORECAST PERIOD...MAINLY FOR THE FRONT
RANGE AND ITS FOOTHILLS. WARMEST DAYS LOOK TO BE FRIDAY WITH
ADIABATIC WARMING AND SUNDAY WITH DIABATIC HEATING WITH PASSING
SHORTWAVE RIDGE. MONDAY AND TUESDAY OF NEXT WEEK LOOK NEARLY AS
WARM AS SUNDAY WITH FURTHER BUILDING OF THE UPPER RIDGE OVER
COLORADO. BY WEDNESDAY...MODELS HINTING AT A CHANGE TO
COOLER/WETTER WEATHER WITH THE APPROACH OF A SHORTWAVE TROUGH.
WILL TREND TOWARD THAT DIRECTION STARTING LATE ON TUESDAY.
AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH THE NEXT 24 HOURS
WITH ONLY SOME HIGH CLOUDS AT TIMES ACROSS THE DENVER AREA. NORMAL
SOUTHERLY DRAINAGE WINDS AT KDEN AND KAPA WILL BECOME NORTHWESTERLY
AROUND 17Z. GUSTS TO 25 KNOTS WILL BE POSSIBLE THROUGH THE
AFTERNOON. AT KBJC...WEST WINDS UP TO 30 KNOTS WILL PREVAIL THROUGH
THE EARLY MORNING AND TURN NORTHWESTERLY THIS AFTERNOON.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....BAKER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
940 AM CST WED NOV 6 2013
.DISCUSSION...
318 AM CST
PRIMARY FORECAST CHALLENGE THIS MORNING IS WRAPPING UP AND ESCORTING
THE CURRENT STORM SYSTEM OUT OF THE AREA.
WAVES OF RAIN ARE SPREADING NORTHEAST FROM MISSOURI INTO THE
AREA...WITH SOME EMBEDDED POCKETS OF HEAVIER RAIN...ESPECIALLY
UPSTREAM. FAIRLY WIDESPREAD RAIN WILL CONTINUE THROUGH THE EARLY
MORNING HOURS BEFORE ENDING FROM WEST TO EAST...ENDING FIRST IN
WESTERN CWA TOWARD MID MORNING...INTO CHGO METRO AROUND MIDDAY AND
NW INDY EARLY/MID AFTERNOON. STILL THINKING GENERALLY A HALF INCH TO
AN INCH OF RAIN WILL BE COMMON WITH LIGHTEST AMOUNTS OVER NC IL AND
PROBABLY SOME EMBEDDED AREAS PICKING UP OVER AN INCH WHERE THE
HEAVIEST ELEMENTS LINE UP. WILL NEED TO KEEP AN EYE OUT FOR SOME
POTENTIAL PONDING OF WATER TYPE ISSUES IN THE URBANIZED POOR
DRAINAGE AREAS FOR THIS MORNING`S RUSH HOUR...BUT OVERALL FLOOD
THREAT APPEARS MINIMAL.
ENDING OF THE RAIN SHOULD BE FAIRLY COINCIDENT WITH THE PASSAGE OF A
FAIRLY STRONG COLD FRONT THIS AFTERNOON. GUSTY NORTHWEST WIND SHIFT
SHOULD SEND TEMPS TUMBLING QUICKLY INTO THE 40S WITH THE FROPA AND
HAVE SHARPENED THERMAL GRADIENT IN THE GRIDS...THOUGH LIKELY NOT
ENOUGH WITH PROBABLY A GOOD 10F DROP WITHIN AN HOUR OF FROPA.
GUIDANCE CONTINUES TO STRONGLY SUGGEST A RAPID CLEARING AFTER THE
FRONT AND WHILE ITS NOT TYPICAL THIS TIME OF YEAR TO NOT HAVE POST
FRONTAL STRATUS...HARD TO DISPUTE SUCH STRONG MODEL AGREEMENT SO
HAVE SHARPENED UP THE CLEARING LINE AND SPED IT UP AS WELL.
WINDS DIMINISH TONIGHT AND ASSUMING WE CLEAR OUT AS ADVERTISED IT
SHOULD BE A FAIRLY COLD NIGHT. SIGNIFICANT ENOUGH DRY AIR ADVECTION
SHOULD TAKE PLACE TO LIMIT THE THREAT OF WIDESPREAD FOG...BUT SOME
SPOTTY VERY SHALLOW GROUND FOG IS CERTAINLY POSSIBLE IN THE FAVORED
LOW SPOTS.
PRETTY LAME WEATHER PATTERN SETTING UP LATE IN THE WEEK THROUGH
EARLY NEXT WEEK WITH WEST NORTHWEST FLOW ALOFT. MODELS DO BRING A
STRONG CLIPPER THROUGH THE UPPER GREAT LAKES LATE FRIDAY/EARLY
SATURDAY...BUT THE TRACK OF THE SYSTEM LOOKS TO BE FAR ENOUGH NORTH
THAT THE BETTER FORCING SHOULD MISS OUR CWA AND WITH SYSTEM HAVING
TO RELY ON SQUEEZING OUT WHAT LITTLE MOISTURE THERE IS ALREADY
PRESENT...THINKING OUR PRECIP CHANCES WILL BE VERY SLIM. INCREASING
SOUTH WINDS FRIDAY NIGHT SHOULD RESULT IN FAIRLY MILD NIGHT WITH
NEAR STEADY TEMPS...OR POSSIBLY AN EVENING LOW WITH SLOWLY RISING
TEMPS. THE MILD START TO THE DAY SHOULD ALLOW FOR A SOMEWHAT MILDER
DAY SATURDAY BEFORE NEXT COLD FRONT COOLS TEMPS DOWN A BIT SUNDAY.
HUGE MODEL DIFFERENCES EARLY NEXT WEEK MEANS LOW CONFIDENCE AND
LEAVES ME GUN SHY TO MAKE ANY CHANGES TO THE BLENDED MODEL
CONCOCTION THAT WE USE TO INITIALIZE THE FORECAST. IF ECMWF IS RIGHT
WE WOULD BE ABOVE AVERAGE TEMP-WISE MONDAY WHILE GFS HAS US SOLIDLY
BELOW AVERAGE...SO STAY TUNED!
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* TIMING OF COLD FRONTAL PASSAGE AND WIND SHIFT BETWEEN 17 AND
1730 UTC.
* TIMING LIFTING OF IFR/LOW MVFR CIGS THIS AFTERNOON.
TRS/KB
//DISCUSSION...UPDATED 12Z...
AT 11Z A DEEP UPPER TROUGH WAS FROM EASTERN MANITOBA SSW OVER THE
EASTERN DAKOTAS AND THEN SW BACK TO OVER THE SOUTHERN HIGH PLAINS.
WITHIN THE FAST SW FLOW OUT AHEAD OF THE TROUGH WERE MULTIPLE
SHORT WAVES LIFTING TOWARDS AND ACROSS THE MID MS VALLEY...ONE OF
WHICH HAD GENERATED SOME CONVECTIVE CELLS AND HEAVY DOWNPOURS
ACROSS THE LOCAL AREA. THIS HEAVIER RAINFALL IS EXPECTED TO BE
MOVING NE OUT THE AREA WITH THE DISTURBANCE MOVING FROM OVERHEAD
TO THE NE OF THE AREA.
THIS LEAVES A SATURATED COLUMN OVER THE AREA FOR THE MID AND LATE
MORNING SO EXPECT CIGS TO CONTINUE ON THE LOW SIDE WHILE -RA/-SHRA
HANG AROUND AS THE LEFT EXIT REGION RIGHT ENTRANCE REGION OF UPPER
JET MAXIMA MOVE OVER THE THE LOCAL AREA THIS MORNING.
TIMING OF CFP AT AROUND 18Z STILL LOOKS ON TRACK WITH HIGHER
RESOLUTION OF RAP OUTPUT MAINTAINING THE SHARPER WIND SHIFT THAT
IS CURRENTLY OBSERVED TO THE W AS OPPOSED TO THE MORE GRADUAL
VEERING DEPICTED BY THE COARSER MODELS. WHILE TREND UPSTREAM
DURING THE LATE EVENING AND OVERNIGHT HAD BEEN S WINDS QUICKLY
SHIFTING TO OUT OF THE N WITH THE FROPA BUT THIS HAS BECOME MORE
OF SSW TO NNW WSHFT EARLY THIS MORNING. WITH THE SURFACE LOW
CONTINUING TO MOVE OFF TO THE NE TODAY FELL THAT THIS WILL
CONTINUE TO TRANSITION TO SW TO NW WSHFT BY THE TIME THE COLD
FRONT MOVES INTO THE LOCAL AREA. WHILE THERE HAD BEEN A FAIRLY
STRONG PRESSURE RISE CENTER FROM N CENTRAL AND SW IA TO EASTERN
KS DURING THE OVERNIGHT THIS PRESSURE RISE CENTER HAS SHIFTED TO
SW MO BY PREDAWN. WHILE DO EXPECT THE NW WINDS BEHIND THE FRONT TO
BE MODERATELY GUSTY FEEL THAT THEY SHOULD GENERALLY STAY IN THE
20-25 KT RANGE.
WITH SOME DECOUPLING OF THE SURFACE TONIGHT UNDER MOSTLY CLEAR TO
CLEAR SKIES WINDS SHOULD SLACKEN TO 10 KT OR LESS DURING THE
OVERNIGHT...AND DIURNALLY DUE TO THE DECOUPLING...AS WELL AS DUE
TO A LARGE ANTICYCLONE BUILDING FROM THE ROCKIES TO THE PLAINS
DURING TODAY AND TONIGHT...BUT ALSO AHEAD OF A SURFACE
TROUGH/SECONDARY COLD FRONT ASSOCIATED WITH ANOTHER SHORT WAVE
PROGGED TO BE DROPPING ACROSS THE DAKOTAS TO THE UPPER MS AND MID
MO VALLEYS OVERNIGHT.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH ON FRONTAL PASSAGE TIMING WITH WIND SHIFT AT 1700 TO 1730
UTC.
* MEDIUM ON TIMING OF CIG IMPROVEMENTS THIS AFTERNOON.
* MEDIUM TO HIGH WITH WINDS.
TRS/KB
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR...NO SIG WX.
FRIDAY...VFR...NO SIG WX.
SATURDAY...VFR...MODERATE SW WINDS.
SUNDAY...VFR...NO SIG WX.
MONDAY...VFR...NO SIG WX.
TUESDAY...VFR. SLIGHT CHANCE SHOWERS.
TRS
&&
.MARINE...
411 AM CST
WINDS WILL GRADUALLY DIMINISH EARLY THIS MORNING BUT STILL BE
GUSTING TO 35 KT ON CENTRAL AND ESPECIALLY SOUTHERN LAKE MI
UNTIL MID MORNING AS LOW PRESSURE LIFTS NORTHEAST FROM WI INTO
ONTARIO BY MIDDAY. AS IT DOES IT WILL SWEEP A COLD FRONT ACROSS
LAKE MICHIGAN SHIFTING WINDS TO OUT OF THE NORTHWEST. THERE WILL
BE A SHORT LULL IN THE WINDS AS THE COLD FRONT PASSES. THEY WILL
WILL INCREASE AGAIN POST FRONTAL THOUGH ARE EXPECTED TO REMAIN
BELOW GALE FORCE THIS AFTERNOON AND TONIGHT AS HIGH PRESSURE
BUILDING SOUTHEASTWARD ACROSS THE ROCKIES AND INTO THE PLAINS
MAINTAINS A FAIRLY STRONG PRESSURE GRADIENT ACROSS THE REGION
DESPITE THE LOW MOVING NE TO THE CENTRAL QUEBEC BY EVENING.
WINDS DIMINISH AND BACK TO SOUTHWEST DURING FRIDAY BEFORE
STRENGTHENING AGAIN LATE FRIDAY AS ANTHER LOW DEEPENS AS IT MOVES
FROM SOUTHERN ALBERTA EAST TO WESTERN ONTARIO. GALE FORCE WINDS
ARE A POSSIBILITY LATER FRIDAY NIGHT INTO SATURDAY AS THE LOW
MOVES ACROSS S CENTRAL CANADA. AS THE LOW CONTINUES EASTWARD
ACROSS ONTARIO SATURDAY A TRAILING COLD FRONT WILL MOVE INTO THE
UPPER GREAT LAKES BRINGING ANOTHER WIND SHIFT TO OUT OF THE
NORTHWEST.
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ675-LMZ777-LMZ779-LMZ872-LMZ874-LMZ876-
LMZ878 UNTIL NOON WEDNESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM
WEDNESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 PM THURSDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
810 AM CST WED NOV 6 2013
.DISCUSSION...
318 AM CST
PRIMARY FORECAST CHALLENGE THIS MORNING IS WRAPPING UP AND ESCORTING
THE CURRENT STORM SYSTEM OUT OF THE AREA.
WAVES OF RAIN ARE SPREADING NORTHEAST FROM MISSOURI INTO THE
AREA...WITH SOME EMBEDDED POCKETS OF HEAVIER RAIN...ESPECIALLY
UPSTREAM. FAIRLY WIDESPREAD RAIN WILL CONTINUE THROUGH THE EARLY
MORNING HOURS BEFORE ENDING FROM WEST TO EAST...ENDING FIRST IN
WESTERN CWA TOWARD MID MORNING...INTO CHGO METRO AROUND MIDDAY AND
NW INDY EARLY/MID AFTERNOON. STILL THINKING GENERALLY A HALF INCH TO
AN INCH OF RAIN WILL BE COMMON WITH LIGHTEST AMOUNTS OVER NC IL AND
PROBABLY SOME EMBEDDED AREAS PICKING UP OVER AN INCH WHERE THE
HEAVIEST ELEMENTS LINE UP. WILL NEED TO KEEP AN EYE OUT FOR SOME
POTENTIAL PONDING OF WATER TYPE ISSUES IN THE URBANIZED POOR
DRAINAGE AREAS FOR THIS MORNING`S RUSH HOUR...BUT OVERALL FLOOD
THREAT APPEARS MINIMAL.
ENDING OF THE RAIN SHOULD BE FAIRLY COINCIDENT WITH THE PASSAGE OF A
FAIRLY STRONG COLD FRONT THIS AFTERNOON. GUSTY NORTHWEST WIND SHIFT
SHOULD SEND TEMPS TUMBLING QUICKLY INTO THE 40S WITH THE FROPA AND
HAVE SHARPENED THERMAL GRADIENT IN THE GRIDS...THOUGH LIKELY NOT
ENOUGH WITH PROBABLY A GOOD 10F DROP WITHIN AN HOUR OF FROPA.
GUIDANCE CONTINUES TO STRONGLY SUGGEST A RAPID CLEARING AFTER THE
FRONT AND WHILE ITS NOT TYPICAL THIS TIME OF YEAR TO NOT HAVE POST
FRONTAL STRATUS...HARD TO DISPUTE SUCH STRONG MODEL AGREEMENT SO
HAVE SHARPENED UP THE CLEARING LINE AND SPED IT UP AS WELL.
WINDS DIMINISH TONIGHT AND ASSUMING WE CLEAR OUT AS ADVERTISED IT
SHOULD BE A FAIRLY COLD NIGHT. SIGNIFICANT ENOUGH DRY AIR ADVECTION
SHOULD TAKE PLACE TO LIMIT THE THREAT OF WIDESPREAD FOG...BUT SOME
SPOTTY VERY SHALLOW GROUND FOG IS CERTAINLY POSSIBLE IN THE FAVORED
LOW SPOTS.
PRETTY LAME WEATHER PATTERN SETTING UP LATE IN THE WEEK THROUGH
EARLY NEXT WEEK WITH WEST NORTHWEST FLOW ALOFT. MODELS DO BRING A
STRONG CLIPPER THROUGH THE UPPER GREAT LAKES LATE FRIDAY/EARLY
SATURDAY...BUT THE TRACK OF THE SYSTEM LOOKS TO BE FAR ENOUGH NORTH
THAT THE BETTER FORCING SHOULD MISS OUR CWA AND WITH SYSTEM HAVING
TO RELY ON SQUEEZING OUT WHAT LITTLE MOISTURE THERE IS ALREADY
PRESENT...THINKING OUR PRECIP CHANCES WILL BE VERY SLIM. INCREASING
SOUTH WINDS FRIDAY NIGHT SHOULD RESULT IN FAIRLY MILD NIGHT WITH
NEAR STEADY TEMPS...OR POSSIBLY AN EVENING LOW WITH SLOWLY RISING
TEMPS. THE MILD START TO THE DAY SHOULD ALLOW FOR A SOMEWHAT MILDER
DAY SATURDAY BEFORE NEXT COLD FRONT COOLS TEMPS DOWN A BIT SUNDAY.
HUGE MODEL DIFFERENCES EARLY NEXT WEEK MEANS LOW CONFIDENCE AND
LEAVES ME GUN SHY TO MAKE ANY CHANGES TO THE BLENDED MODEL
CONCOCTION THAT WE USE TO INITIALIZE THE FORECAST. IF ECMWF IS RIGHT
WE WOULD BE ABOVE AVERAGE TEMP-WISE MONDAY WHILE GFS HAS US SOLIDLY
BELOW AVERAGE...SO STAY TUNED!
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* TIMING OF COLD FRONTAL PASSAGE AND WIND SHIFT AROUND MIDDAY.
* WIND SPEED AND GUSTS PRE AND POST FRONTAL.
* TIMING LIFTING OF IFR/LOW MVFR CIGS THIS AFTERNOON.
TRS/KB
//DISCUSSION...UPDATED 12Z...
AT 11Z A DEEP UPPER TROUGH WAS FROM EASTERN MANITOBA SSW OVER THE
EASTERN DAKOTAS AND THEN SW BACK TO OVER THE SOUTHERN HIGH PLAINS.
WITHIN THE FAST SW FLOW OUT AHEAD OF THE TROUGH WERE MULTIPLE
SHORT WAVES LIFTING TOWARDS AND ACROSS THE MID MS VALLEY...ONE OF
WHICH HAD GENERATED SOME CONVECTIVE CELLS AND HEAVY DOWNPOURS
ACROSS THE LOCAL AREA. THIS HEAVIER RAINFALL IS EXPECTED TO BE
MOVING NE OUT THE AREA WITH THE DISTURBANCE MOVING FROM OVERHEAD
TO THE NE OF THE AREA.
THIS LEAVES A SATURATED COLUMN OVER THE AREA FOR THE MID AND LATE
MORNING SO EXPECT CIGS TO CONTINUE ON THE LOW SIDE WHILE -RA/-SHRA
HANG AROUND AS THE LEFT EXIT REGION RIGHT ENTRANCE REGION OF UPPER
JET MAXIMA MOVE OVER THE THE LOCAL AREA THIS MORNING.
TIMING OF CFP AT AROUND 18Z STILL LOOKS ON TRACK WITH HIGHER
RESOLUTION OF RAP OUTPUT MAINTAINING THE SHARPER WIND SHIFT THAT
IS CURRENTLY OBSERVED TO THE W AS OPPOSED TO THE MORE GRADUAL
VEERING DEPICTED BY THE COARSER MODELS. WHILE TREND UPSTREAM
DURING THE LATE EVENING AND OVERNIGHT HAD BEEN S WINDS QUICKLY
SHIFTING TO OUT OF THE N WITH THE FROPA BUT THIS HAS BECOME MORE
OF SSW TO NNW WSHFT EARLY THIS MORNING. WITH THE SURFACE LOW
CONTINUING TO MOVE OFF TO THE NE TODAY FELL THAT THIS WILL
CONTINUE TO TRANSITION TO SW TO NW WSHFT BY THE TIME THE COLD
FRONT MOVES INTO THE LOCAL AREA. WHILE THERE HAD BEEN A FAIRLY
STRONG PRESSURE RISE CENTER FROM N CENTRAL AND SW IA TO EASTERN
KS DURING THE OVERNIGHT THIS PRESSURE RISE CENTER HAS SHIFTED TO
SW MO BY PREDAWN. WHILE DO EXPECT THE NW WINDS BEHIND THE FRONT TO
BE MODERATELY GUSTY FEEL THAT THEY SHOULD GENERALLY STAY IN THE
20-25 KT RANGE.
WITH SOME DECOUPLING OF THE SURFACE TONIGHT UNDER MOSTLY CLEAR TO
CLEAR SKIES WINDS SHOULD SLACKEN TO 10 KT OR LESS DURING THE
OVERNIGHT...AND DIURNALLY DUE TO THE DECOUPLING...AS WELL AS DUE
TO A LARGE ANTICYCLONE BUILDING FROM THE ROCKIES TO THE PLAINS
DURING TODAY AND TONIGHT...BUT ALSO AHEAD OF A SURFACE
TROUGH/SECONDARY COLD FRONT ASSOCIATED WITH ANOTHER SHORT WAVE
PROGGED TO BE DROPPING ACROSS THE DAKOTAS TO THE UPPER MS AND MID
MO VALLEYS OVERNIGHT.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH ON FRONTAL PASSAGE TIMING WITH WIND SHIFT AT 18Z +/- 1HR.
* MEDIUM ON TIMING OF CIG IMPROVEMENTS THIS AFTERNOON.
* MEDIUM TO HIGH WITH WINDS.
TRS/KB
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR...NO SIG WX.
FRIDAY...VFR...NO SIG WX.
SATURDAY...VFR...MODERATE SW WINDS.
SUNDAY...VFR...NO SIG WX.
MONDAY...VFR...NO SIG WX.
TUESDAY...VFR. SLIGHT CHANCE SHOWERS.
TRS
&&
.MARINE...
411 AM CST
WINDS WILL GRADUALLY DIMINISH EARLY THIS MORNING BUT STILL BE
GUSTING TO 35 KT ON CENTRAL AND ESPECIALLY SOUTHERN LAKE MI
UNTIL MID MORNING AS LOW PRESSURE LIFTS NORTHEAST FROM WI INTO
ONTARIO BY MIDDAY. AS IT DOES IT WILL SWEEP A COLD FRONT ACROSS
LAKE MICHIGAN SHIFTING WINDS TO OUT OF THE NORTHWEST. THERE WILL
BE A SHORT LULL IN THE WINDS AS THE COLD FRONT PASSES. THEY WILL
WILL INCREASE AGAIN POST FRONTAL THOUGH ARE EXPECTED TO REMAIN
BELOW GALE FORCE THIS AFTERNOON AND TONIGHT AS HIGH PRESSURE
BUILDING SOUTHEASTWARD ACROSS THE ROCKIES AND INTO THE PLAINS
MAINTAINS A FAIRLY STRONG PRESSURE GRADIENT ACROSS THE REGION
DESPITE THE LOW MOVING NE TO THE CENTRAL QUEBEC BY EVENING.
WINDS DIMINISH AND BACK TO SOUTHWEST DURING FRIDAY BEFORE
STRENGTHENING AGAIN LATE FRIDAY AS ANTHER LOW DEEPENS AS IT MOVES
FROM SOUTHERN ALBERTA EAST TO WESTERN ONTARIO. GALE FORCE WINDS
ARE A POSSIBILITY LATER FRIDAY NIGHT INTO SATURDAY AS THE LOW
MOVES ACROSS S CENTRAL CANADA. AS THE LOW CONTINUES EASTWARD
ACROSS ONTARIO SATURDAY A TRAILING COLD FRONT WILL MOVE INTO THE
UPPER GREAT LAKES BRINGING ANOTHER WIND SHIFT TO OUT OF THE
NORTHWEST.
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ567-LMZ669-LMZ671-LMZ673-LMZ868-LMZ870 UNTIL 9
AM WEDNESDAY.
GALE WARNING...LMZ080-LMZ675-LMZ777-LMZ779-LMZ872-LMZ874-LMZ876-
LMZ878 UNTIL NOON WEDNESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM
WEDNESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 PM THURSDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
655 AM CST WED NOV 6 2013
.DISCUSSION...
318 AM CST
PRIMARY FORECAST CHALLENGE THIS MORNING IS WRAPPING UP AND ESCORTING
THE CURRENT STORM SYSTEM OUT OF THE AREA.
WAVES OF RAIN ARE SPREADING NORTHEAST FROM MISSOURI INTO THE
AREA...WITH SOME EMBEDDED POCKETS OF HEAVIER RAIN...ESPECIALLY
UPSTREAM. FAIRLY WIDESPREAD RAIN WILL CONTINUE THROUGH THE EARLY
MORNING HOURS BEFORE ENDING FROM WEST TO EAST...ENDING FIRST IN
WESTERN CWA TOWARD MID MORNING...INTO CHGO METRO AROUND MIDDAY AND
NW INDY EARLY/MID AFTERNOON. STILL THINKING GENERALLY A HALF INCH TO
AN INCH OF RAIN WILL BE COMMON WITH LIGHTEST AMOUNTS OVER NC IL AND
PROBABLY SOME EMBEDDED AREAS PICKING UP OVER AN INCH WHERE THE
HEAVIEST ELEMENTS LINE UP. WILL NEED TO KEEP AN EYE OUT FOR SOME
POTENTIAL PONDING OF WATER TYPE ISSUES IN THE URBANIZED POOR
DRAINAGE AREAS FOR THIS MORNING`S RUSH HOUR...BUT OVERALL FLOOD
THREAT APPEARS MINIMAL.
ENDING OF THE RAIN SHOULD BE FAIRLY COINCIDENT WITH THE PASSAGE OF A
FAIRLY STRONG COLD FRONT THIS AFTERNOON. GUSTY NORTHWEST WIND SHIFT
SHOULD SEND TEMPS TUMBLING QUICKLY INTO THE 40S WITH THE FROPA AND
HAVE SHARPENED THERMAL GRADIENT IN THE GRIDS...THOUGH LIKELY NOT
ENOUGH WITH PROBABLY A GOOD 10F DROP WITHIN AN HOUR OF FROPA.
GUIDANCE CONTINUES TO STRONGLY SUGGEST A RAPID CLEARING AFTER THE
FRONT AND WHILE ITS NOT TYPICAL THIS TIME OF YEAR TO NOT HAVE POST
FRONTAL STRATUS...HARD TO DISPUTE SUCH STRONG MODEL AGREEMENT SO
HAVE SHARPENED UP THE CLEARING LINE AND SPED IT UP AS WELL.
WINDS DIMINISH TONIGHT AND ASSUMING WE CLEAR OUT AS ADVERTISED IT
SHOULD BE A FAIRLY COLD NIGHT. SIGNIFICANT ENOUGH DRY AIR ADVECTION
SHOULD TAKE PLACE TO LIMIT THE THREAT OF WIDESPREAD FOG...BUT SOME
SPOTTY VERY SHALLOW GROUND FOG IS CERTAINLY POSSIBLE IN THE FAVORED
LOW SPOTS.
PRETTY LAME WEATHER PATTERN SETTING UP LATE IN THE WEEK THROUGH
EARLY NEXT WEEK WITH WEST NORTHWEST FLOW ALOFT. MODELS DO BRING A
STRONG CLIPPER THROUGH THE UPPER GREAT LAKES LATE FRIDAY/EARLY
SATURDAY...BUT THE TRACK OF THE SYSTEM LOOKS TO BE FAR ENOUGH NORTH
THAT THE BETTER FORCING SHOULD MISS OUR CWA AND WITH SYSTEM HAVING
TO RELY ON SQUEEZING OUT WHAT LITTLE MOISTURE THERE IS ALREADY
PRESENT...THINKING OUR PRECIP CHANCES WILL BE VERY SLIM. INCREASING
SOUTH WINDS FRIDAY NIGHT SHOULD RESULT IN FAIRLY MILD NIGHT WITH
NEAR STEADY TEMPS...OR POSSIBLY AN EVENING LOW WITH SLOWLY RISING
TEMPS. THE MILD START TO THE DAY SHOULD ALLOW FOR A SOMEWHAT MILDER
DAY SATURDAY BEFORE NEXT COLD FRONT COOLS TEMPS DOWN A BIT SUNDAY.
HUGE MODEL DIFFERENCES EARLY NEXT WEEK MEANS LOW CONFIDENCE AND
LEAVES ME GUN SHY TO MAKE ANY CHANGES TO THE BLENDED MODEL
CONCOCTION THAT WE USE TO INITIALIZE THE FORECAST. IF ECMWF IS RIGHT
WE WOULD BE ABOVE AVERAGE TEMP-WISE MONDAY WHILE GFS HAS US SOLIDLY
BELOW AVERAGE...SO STAY TUNED!
IZZI
&&
//ORD AND MDW CONCERNS...UPDATED 12Z...
* LLWS INTO EARLY THIS MORNING.
* ENDING OF MODERATE TO OCNLY HEAVY RA WITHIN THE NEXT HR OR TWO.
* TIMING COLD FRONTAL PASSAGE.
* WIND SPEED AND GUSTS PRE AND POST FRONTAL.
* LIFTING OF IFR CIGS TO MVFR FOLLOWING CFP AND EVENTUALLY TO VFR
LATER THIS AFTERNOON.
TRS
//DISCUSSION...UPDATED 12Z...
AT 11Z A DEEP UPPER TROUGH WAS FROM EASTERN MANITOBA SSW OVER THE
EASTERN DAKOTAS AND THEN SW BACK TO OVER THE SOUTHERN HIGH PLAINS.
WITHIN THE FAST SW FLOW OUT AHEAD OF THE TROUGH WERE MULTIPLE
SHORT WAVES LIFTING TOWARDS AND ACROSS THE MID MS VALLEY...ONE OF
WHICH HAD GENERATED SOME CONVECTIVE CELLS AND HEAVY DOWNPOURS
ACROSS THE LOCAL AREA. THIS HEAVIER RAINFALL IS EXPECTED TO BE
MOVING NE OUT THE AREA WITH THE DISTURBANCE MOVING FROM OVERHEAD
TO THE NE OF THE AREA.
THIS LEAVES A SATURATED COLUMN OVER THE AREA FOR THE MID AND LATE
MORNING SO EXPECT CIGS TO CONTINUE ON THE LOW SIDE WHILE -RA/-SHRA
HANG AROUND AS THE LEFT EXIT REGION RIGHT ENTRANCE REGION OF UPPER
JET MAXIMA MOVE OVER THE THE LOCAL AREA THIS MORNING.
TIMING OF CFP AT AROUND 18Z STILL LOOKS ON TRACK WITH HIGHER
RESOLUTION OF RAP OUTPUT MAINTAINING THE SHARPER WIND SHIFT THAT
IS CURRENTLY OBSERVED TO THE W AS OPPOSED TO THE MORE GRADUAL
VEERING DEPICTED BY THE COARSER MODELS. WHILE TREND UPSTREAM
DURING THE LATE EVENING AND OVERNIGHT HAD BEEN S WINDS QUICKLY
SHIFTING TO OUT OF THE N WITH THE FROPA BUT THIS HAS BECOME MORE
OF SSW TO NNW WSHFT EARLY THIS MORNING. WITH THE SURFACE LOW
CONTINUING TO MOVE OFF TO THE NE TODAY FELL THAT THIS WILL
CONTINUE TO TRANSITION TO SW TO NW WSHFT BY THE TIME THE COLD
FRONT MOVES INTO THE LOCAL AREA. WHILE THERE HAD BEEN A FAIRLY
STRONG PRESSURE RISE CENTER FROM N CENTRAL AND SW IA TO EASTERN
KS DURING THE OVERNIGHT THIS PRESSURE RISE CENTER HAS SHIFTED TO
SW MO BY PREDAWN. WHILE DO EXPECT THE NW WINDS BEHIND THE FRONT TO
BE MODERATELY GUSTY FEEL THAT THEY SHOULD GENERALLY STAY IN THE
20-25 KT RANGE.
WITH SOME DECOUPLING OF THE SURFACE TONIGHT UNDER MOSTLY CLEAR TO
CLEAR SKIES WINDS SHOULD SLACKEN TO 10 KT OR LESS DURING THE
OVERNIGHT...AND DIURNALLY DUE TO THE DECOUPLING...AS WELL AS DUE
TO A LARGE ANTICYCLONE BUILDING FROM THE ROCKIES TO THE PLAINS
DURING TODAY AND TONIGHT...BUT ALSO AHEAD OF A SURFACE
TROUGH/SECONDARY COLD FRONT ASSOCIATED WITH ANOTHER SHORT WAVE
PROGGED TO BE DROPPING ACROSS THE DAKOTAS TO THE UPPER MS AND MID
MO VALLEYS OVERNIGHT.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH ON FRONTAL PASSAGE AND WIND SHIFT AT 18Z +/- 1HR.
* MEDIUM ON TIMING OF IFR LIFTING BACK TO MVFR WITH FROPA.
* HIGH ON WIND DIRECTIONS PRE AND POST FRONTAL...MODERATE IN
SUSTAINED AND GUST SPEEDS EITHER SIDE OF THE COLD FRONT.
* HIGH ON CLEARING SKY DURING LATE AFTERNOON-EARLY EVENING.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR...NO SIG WX.
FRIDAY...VFR...NO SIG WX.
SATURDAY...VFR...MODERATE SW WINDS.
SUNDAY...VFR...NO SIG WX.
MONDAY...VFR...NO SIG WX.
TUESDAY...VFR. SLIGHT CHANCE SHOWERS.
TRS
&&
.MARINE...
411 AM CST
WINDS WILL GRADUALLY DIMINISH EARLY THIS MORNING BUT STILL BE
GUSTING TO 35 KT ON CENTRAL AND ESPECIALLY SOUTHERN LAKE MI
UNTIL MID MORNING AS LOW PRESSURE LIFTS NORTHEAST FROM WI INTO
ONTARIO BY MIDDAY. AS IT DOES IT WILL SWEEP A COLD FRONT ACROSS
LAKE MICHIGAN SHIFTING WINDS TO OUT OF THE NORTHWEST. THERE WILL
BE A SHORT LULL IN THE WINDS AS THE COLD FRONT PASSES. THEY WILL
WILL INCREASE AGAIN POST FRONTAL THOUGH ARE EXPECTED TO REMAIN
BELOW GALE FORCE THIS AFTERNOON AND TONIGHT AS HIGH PRESSURE
BUILDING SOUTHEASTWARD ACROSS THE ROCKIES AND INTO THE PLAINS
MAINTAINS A FAIRLY STRONG PRESSURE GRADIENT ACROSS THE REGION
DESPITE THE LOW MOVING NE TO THE CENTRAL QUEBEC BY EVENING.
WINDS DIMINISH AND BACK TO SOUTHWEST DURING FRIDAY BEFORE
STRENGTHENING AGAIN LATE FRIDAY AS ANTHER LOW DEEPENS AS IT MOVES
FROM SOUTHERN ALBERTA EAST TO WESTERN ONTARIO. GALE FORCE WINDS
ARE A POSSIBILITY LATER FRIDAY NIGHT INTO SATURDAY AS THE LOW
MOVES ACROSS S CENTRAL CANADA. AS THE LOW CONTINUES EASTWARD
ACROSS ONTARIO SATURDAY A TRAILING COLD FRONT WILL MOVE INTO THE
UPPER GREAT LAKES BRINGING ANOTHER WIND SHIFT TO OUT OF THE
NORTHWEST.
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM
WEDNESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM
WEDNESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 PM THURSDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS TOPEKA KS
257 PM CST Wed Nov 6 2013
.SHORT TERM...(This Evening through Thursday)
Issued at 257 PM CST WED NOV 6 2013
The 20Z water vapor imagery shows a upper level trough progressing
east through the plains into the upper Midwest and MS river valley.
Weak ridging was noted over the inter-mountain west with another
shortwave trough approaching the pacific northwest coast. At the
surface, a cool and much dryer ridge of high pressure has settled
into the central plains.
For tonight and Thursday, dry and cool weather is expected to
persist as the surface ridge keeps dry air over the forecast area.
Additionally there is no obvious wave within the northwest flow
aloft to suggest any forcing for precip. The low level saturation
that has allowed the STRATOCU deck to linger over eastern KS through
the afternoon is expected to eventually mix out and/or move east.
Latest visible satellite seems to support the RAP and HRRR PROGS of
the low level saturation dissipating. So think tonight will
eventually become mostly clear. Am a little concerned about the
formation of fog overnight since the boundary layer moisture has not
mixed out and cross over temps are 3 to 5 degrees above the forecast
min temps. The one thing against a good radiational fog is that the
models keep the center of the surface ridge over western KS and the
winds never go calm with lower dewpoint temps advecting in from the
west through the night. Think this may be enough to limit any fog
development to the favored low spots near bodies of water where the
winds are most likely to be light and variable. Thursday should be
sunny with a dry northwest flow aloft and the surface ridge still
over eastern KS. Because of this there does not look to be a lot of
low level warm air advection tomorrow so highs may struggle to warm
into the mid 50s.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 257 PM CST WED NOV 6 2013
Winds and cloud cover should steadily increase late Thursday night
into Friday on the south end of a rather potent wave moving east
through the Dakotas. Clouds will be of the high variety with still
dry low to mid levels, limiting any precipitation chances. Specifics
on how fast and thick the clouds are Tuesday night will play a large
role in how cool temps will fall as southwest winds ramp up just off
the surface through the night. Expect winds and clouds to hold off
the longest in the south and east for the coolest temps there. A
quite windy Friday remains to be expected, though the strongest
winds may be a bit farther east, with near advisory levels possible
for much of the area. Overnight and early day warm air advection
should push temps well into the 60s. Elevated fire danger is still
anticipated in the warm, dry, and windy boundary layer. The modified
Pacific cold front with the Dakotas wave sinks in late Friday night
into Saturday and should bring little cooling and much lighter
winds.
Zonal flow aloft becomes more northwesterly by Monday as an upper
trof off the west coast deepens. Modest moisture return in
isentropic lift may still be enough for a few showers Monday night
into Tuesday. The main periods of question are for Tuesday night
into Wednesday. The 12Z GFS and ECMWF are in rather strong agreement
with a shortwave diving south into the Northern Plains and western
Great Lakes Tuesday and on southeast through the mid Mississippi
Valley Tuesday night and Wednesday. The source region of the airmass
is northern Alaska and Yukon, but does linger for 12-24 hours in
southern Canada before coming into the CONUS, and snowpack in this
area does not appear to be now or look likely to increase much
before its arrival. Still, the operational runs drop 850mb temps
well below 0 C with its passage and suggest one of the coldest days
of the cold season so far. The ensembles show a rather large spread
in temps and height fields however, and this is not unexpected with
this smaller scale wave coming through a somewhat complex pattern.
Will suggest a cooling trend and some chance for liquid
precipitation at this point but confidence is low.
&&
.AVIATION...(For the 18Z TAFs through 18Z Thursday Afternoon)
Issued at 1135 AM CST WED NOV 6 2013
RAP and HRRR solutions show the low level saturation hanging on
through much of the afternoon. With satellite imagery showing a
decent STRATOCU deck extending upstream into NEB, will hang onto
MVFR CIGS until the late afternoon. Am a little concerned for
some shallow ground fog developing late tonight. The main hiccup
in fog formation is the models indicating a weak surface trough
moving through northeast KS overnight implying some mixing could
occur. But if skies clear out and the boundary layer decouples it
may not matter that a trough propagates through the area.
Therefore think the chances for ground fog within the KS river
valley are high enough to include a mention in the TOP and MHK
terminals.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...65
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1135 AM CST Wed Nov 6 2013
...AVIATION UPDATE...
.SHORT TERM...(Today and Tonight)
Issued at 318 AM CST WED NOV 6 2013
Quiet weather is expected through tomorrow morning as the mid level
trough axis progresses through the region. Cooler air is working
into the CWA behind the front with temps in mid 30s already in north
central Kansas. Low temperatures this morning will range from the
low to upper 30s after all of the precipitation has exited the
region. Drier mid level air will began to filter in today from the
northwest although lower levels will be slower to dry out. Forecast
soundings show that cold air advection will prevent drying and low
level RH remains high in the form of a stratus deck. Therefore the
only issue today will be how fast the clouds can clear or scatter
out of the area. As of now it appears clearing will begin in north
central Kansas during mid morning. The clearing should reach far
northeast Kansas in the early afternoon hours. Northwest winds will
also decrease from west to east through out the day although the
eastern half of the CWA will remain gusty until around sunset. High
temperatures stay in the upper 40s in the northeast CWA while
southwest portions reach the low 50s. Later tonight high pressure
builds into the central plains leaving skies clear and winds light.
Low temperatures tomorrow morning drop into the upper 20s to low
30s.
.LONG TERM...(Thursday through Tuesday)
Issued at 318 AM CST WED NOV 6 2013
Thursday through Sunday night, the mid and upper level flow will
become zonal. An upper level trough will move east across the
northern plains on Friday. The stronger ascent ahead of this wave
will remain well northeast of the CWA along with any precip chances.
Highs Thursday will warm into the mid to upper 50s.
The increasing westerly mid level flow across the central Rockies
will cause a lees surface trough to deepen Friday. The resulting
pressure gradient across central KS will cause southerly winds to
increase to 20 to 30 MPH with some gusts to 40 MPH Friday
afternoon. The southerly winds may reach near wind advisory
criteria across the western CWA Friday afternoon. Given drier
vegetation and gusty southerly winds, there will be a very high
fire danger. The southerly winds will help high temperatures to
warm into the lower to mid 60s.
As the upper level trough moves east across the Great Lakes States
Friday night, a cold front will move southward across the CWA Saturday
morning. The airmass behind the front will only be slightly
cooler. Highs Saturday will reach around 60, with mid to upper 50s
on Sunday.
Monday through Tuesday, the weak cold front will stall out across
central OK and begin to move north as a warm front. Deeper moisture
advection and isentropic lift will cause clouds and a slight chance
for showers Monday night into Tuesday. Highs will reach the mid to
upper 50s on Monday, with lower to mid 50s on Tuesday.
&&
.AVIATION...(For the 18Z TAFs through 18Z Thursday Afternoon)
Issued at 1135 AM CST WED NOV 6 2013
RAP and HRRR solutions show the low level saturation hanging on
through much of the afternoon. With satellite imagery showing a
decent STRATOCU deck extending upstream into NEB, will hang onto
MVFR CIGS until the late afternoon. Am a little concerned for
some shallow ground fog developing late tonight. The main hiccup
in fog formation is the models indicating a weak surface trough
moving through northeast KS overnight implying some mixing could
occur. But if skies clear out and the boundary layer decouples it
may not matter that a trough propagates through the area.
Therefore think the chances for ground fog within the KS river
valley are high enough to include a mention in the TOP and MHK
terminals.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...Sanders
LONG TERM...Gargan
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1238 AM EST WED NOV 6 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY MOVE EAST OF THE REGION OVERNIGHT THROUGH
WEDNESDAY. A COLD FRONT WILL APPROACH WEDNESDAY NIGHT AND CROSS THE
REGION BY THURSDAY AFTERNOON. SURFACE HIGH PRES WILL THEN SLOWLY
BUILD FROM THE SOUTHWEST TOWARD THE REGION FRIDAY AND SATURDAY
WHILE AN UPPER LEVEL TROUGH CROSSES NORTHERN MAINE FROM QUEBEC ON
FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
1230 AM UPDATE...ADJUSTMENTS NEEDED FOR THE TEMPERATURES AS THEY
HAVE LEVELED OFF FOR THE TIME BEING GIVEN MID AND HIGH CLOUDS ARE
MOVING ACROSS THE CWA. THIS IS IN RESPONSE TO WARMING IN THE UPPER
LEVELS ESPECIALLY IN THE 800-700MB LAYER AS SEEN ON THE 00Z UA.
TEMPERATURES COULD FALL BACK SOME ESPECIALLY IN THE LOW LYING
AREAS BY 12Z AS SOME PARTIAL CLEARING SEEN ON THE IR SATL IMAGERY.
CONCERN IS THERE FOR SOME LIGHT PRECIP WHICH COULD BE IN THE FORM
OF SLEET OR -FZRA AS SEEN ON THE GFS SOUNDINGS W/A MOIST LAYER
FROM 850-700MBS. ATTM, THE RUC WAS DOING THE BEST OUT OF THE
MESOSCALE GUIDANCE IN SHOWING A GRADUAL WARMUP BY 7-8AM WHICH
WOULD ALLEVIATE ANY FREEZING PRECIP.
PREVIOUS DISCUSSION...
INCREASING CLOUDS OVER THE NORTH LATE TONIGHT AND TOMORROW
MORNING ASSOCIATED WITH A VERY WEAK UPPER LEVEL SHORTWAVE, THEN
DECREASING CLOUDS LATE MORNING TO EARLY AFTERNOON, AND FINALLY
INCREASING CLOUDS AGAIN LATE WEDNESDAY AFTERNOON AS THE SURFACE
COLD FRONT APPROACHES FROM THE WEST.
CONDITIONS LOOK TO BE DRY THROUGH WEDNESDAY AFTERNOON. CANNOT RULE
OUT A SPRINKLE OR FLURRY WEDNESDAY MORNING WITH THE VERY WEAK
SHORTWAVE. EXPECT MOST OF THE RAIN TO HOLD OFF UNTIL LATER
WEDNESDAY NIGHT WITH THE MAIN COLD FRONT.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
TDY`S 12Z MODELS WERE IN VERY GOOD AGREEMENT WITH THE ONSET...
DURATION AND EXIT OF SHWRS AHEAD OF A COLD FRONT THAT APCHS THE
FA LATE WED NGT AND CROSSES BETWEEN MIDDAY AND LATE AFTN THU.
TYPICAL...THE OPNL 12Z GFS IS ABOUT 3 TO 6 HRS FASTER THAN OTHER
MODELS SUCH AS THE 12Z ECMWF...SO WE BLENDED THESE TMG DIFFERENCES
RESULTING IN ERLY EVE EXIT POPS FOR OUR FA...WITH MEASURABLE
PRECIP WRAPPING UP SIG BEFORE SFC TEMPS FALL TO AND BLO FZG
LATE THU NGT AFT REACHING HI TEMPS OF 50S THU DYTM. TOTAL
EVENT QPF FOR THIS EVENT BY MODEL CONSENSUS IS BETWEEN 2 AND
4 TENTHS OF AN INCH...ENOUGH TO JUSTIFY CATEGORICAL POPS WITHE
CORE OF THIS EVENT...CAPPED TO 90 PERCENT TO REFLECT ANY REMAINING
TMG UNCERTAINTY ATTM.
AFT A BRIEF BREAK IN CLD CVR LATE THU NGT AND ERLY FRI MORN...AN
UPPER LVL TROF FROM QB WILL BRING CLDNS PARTICULARLY FOR NRN/CNTRL
PTNS OF THE FA...ALG WITH SCT AFTN/EVE SN SHWRS. BETWEEN THE LLVL
COLD ADVCN WHICH WILL BE ACCOMPANIED BY WNW WINDS OF 15 TO 25 MPH
AND CLD CVR...HI TEMPS FRI WILL BE AT LEAST 15 DEG COLDER THAN
THU.
.LONG TERM /LATE FRIDAY NIGHT THROUGH TUESDAY/...
SLOW CLRG IS XPCTD ACROSS THE FA LATE FRI NGT INTO SAT MORN WITH
SLOWLY DECREASING WINDS. NOT MUCH OPPORTUNITY FOR RADIATIONAL
COOLING ANYWHERE OVR THE FA FRI NGT...WITH HI TEMPS SAT RECOVERING
PERHAPS A DEG OR TWO WARMER THAN FRI DUE TO THE POTENTIAL OF
GREATER SUNSHINE.
AFT FAIR CONDITIONS SAT EVE...CLDS WILL BE ON THE INCREASE LATE SAT
NGT AND ERLY SUN MORN AHEAD OF A FAST ZONAL CLIPPER S/WV FROM S
CNTRL CAN. EITHER SN SHWRS OR A PD OF LGT SN WILL THEN COMMENCE
MID TO LATE SUN MORN...MIXING WITH OR CHANGE TO RN OVR CNTRL AND
SPCLY DOWNEAST AREAS SUN AFTN AS WEAK LLVL WARM ADVCN BRINGS A
SHALLOW LLVL BL OF MARINE AIR NWRD FROM THE GULF OF ME. LATEST
MODEL GUIDANCE SUGGESTS NOT MUCH MORE THAN A TENTH OF AN INCH OF
TOTAL LIQUID EQUIV WITH THIS SYSTEM ATTM...SO EVEN IF THIS EVENT
WERE ALL SN FOR NRN LOCATIONS...NOT MORE THAN AN INCH OF SNFL
WOULD RESULT...BUT CANNOT RULE OUT SLICK ROADWAYS LATE SUN MORN
IF THIS EVENT TMG HOLDS. AFT ANY REMAINING PRECIP ENDS ERLY SUN
EVE...MDT LLVL COLD ADVCN WILL BRING COLDER AIR TO THE REGION
BEGINNING LATE SUN NGT THRU TUE...PERHAPS COLDER THAN WHAT WE
INDICATE THAN THIS UPDATE...WHICH WE WILL REFINE BASED ON FUTURE
MODEL CONSISTENCY ON THE INTENSITY OF THE COLD AIRMASS.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: VFR CONDITIONS EXPECTED THROUGH WEDNESDAY AFTERNOON.
THERE ARE SOME 4000 FOOT CEILINGS THIS AFTERNOON OVER COASTAL
DOWNEAST, BUT EXPECT THESE TO RISE TONIGHT. ALSO, SITES FROM KPQI
NORTH MAY SEE SOME CEILINGS IN THE 4000 TO 6000 FOOT RANGE LATE
TONIGHT AND TOMORROW MORNING.
SHORT TO LONG TERM: CIGS AND VSBYS WILL LOWER FROM LOW VFR WED EVE
TO IFR BY THU MORN AS A PRE-COLD FRONTAL BAND OF SHWRS ENTERS THE
REGION FROM QB. CIGS AND VSBYS WILL REMAIN IFR THRU THU...IMPROVING
BACK TO VFR FOR DOWNEAST SITES AND TO MVFR NRN TAF SITES THU NGT
BEHIND THE COLD FRONT. MVFR BKN-OVC SC WILL CONT ACROSS NRN TAF
SITES FRI WHILE DOWNEAST SITES REMAIN VFR...THEN ALL SITES WILL BE
VFR FRI NGT THRU SAT NGT. THE NEXT CHC OF MVFR/IFR WILL BE WITH SN
SHWRS AND DOWNEAST RN/SN SHWRS ON SUN.
&&
.MARINE...
NEAR TERM: CONDITIONS WILL REMAIN BELOW SMALL CRAFT LEVELS THROUGH
WEDNESDAY AFTERNOON, ALTHOUGH SOUTH WINDS WILL INCREASE TO AROUND
15 KNOTS WEDNESDAY AFTERNOON WITH COMBINED SEAS TO 4 FEET AS THE
COLD FRONT APPROACHES.
SHORT TO LONG TERM: SCA CONDITIONS SHOULD CONT THU WITH LONG FETCH
SRLY COMPONENT SFC WINDS AND THEN BEHIND THE COLD FRONT LATER THU
NGT INTO FRI NGT WITH BRISK NW WINDS. WINDS AND SEAS SHOULD THEN
SUBSIDE BLO SCA CRITERIA LATER SAT...AND CONT SO THRU MON. WENT WITH
A BLEND OF 12Z WW3...SWAN GFS...SWAN NAM AND SOME OF THE PREV FCST
FOR WV HTS THIS UPDATE.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
702 PM EST THU NOV 7 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 344 PM EST THU NOV 7 2013
A SURFACE TROUGH IN COMBINATION WITH AN UPPER AIR DISTURBANCE WILL
BRING SHOWERS OF MIXED RAIN AND SNOW TO THE LAKE SHORE AREA...
MOSTLY SOUTH OF MUSKEGON THIS EVENING. THEN HIGH PRESSURE WILL
CLEAR THE SKIES AFTER MIDNIGHT. THE HIGH PRESSURE SYSTEM WILL MOVE
ACROSS SOUTHWEST MICHIGAN FRIDAY PROVIDING SOME SUNSHINE BUT
CHILLY TEMPERATURES.
FRIDAY NIGHT INTO SATURDAY A STORM SYSTEM MOVING EAST ALONG OR
JUST NORTH OF THE CANADIAN BOARDER WILL BRING A FRONTAL SYSTEM
THROUGH THE AREA EARLY SATURDAY MORNING. THAT SYSTEM WILL BRING A
PERIOD OF SHOWERS LATE FRIDAY NIGHT NIGHT INTO SATURDAY.
FINALLY A STRONG COLD FRONT COMES THROUGH THE AREA MONDAY WITH
SHOWERS OF MIXED RAIN AND SNOW.... THEN THE COLDEST AIR OF THE
SEASON MOVES INTO SOUTHWEST MICHIGAN FOR TUESDAY AND WEDNESDAY.
TEMPERATURES WILL STRUGGLE TO GET ABOVE FREEZING EVEN IN THE
AFTERNOON.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 344 PM EST THU NOV 7 2013
THERE ARE TWO ISSUES OF PRIMARY CONCERN FOR THIS FORECAST PERIOD.
FIRST IS THE LAKE EFFECT SHOWERS EXPECTED THIS EVENING... PRIMARILY
SOUTH AND WEST OF GRAND RAPIDS. THEN THERE IS THE PRECIPITATION
WITH THE WARM FRONT FOR THE SYSTEM TRACKING EAST ALONG THE
CANADIAN BORDER SATURDAY INTO SATURDAY NIGHT.
AS SEEN ON BOTH THE WATER VAPOR IMAGE LOOPS...IR AND VISIBLE
SATELLITE IMAGE LOOPS... THERE IS A SERIES OF THREE SHORTWAVES
BETWEEN CHICAGO AND MINNEAPOLIS TRACKING EAST SOUTHEAST. ALREADY
SOME LIGHT SHOWERS ARE SHOWING UP ON RADAR OVER WEST CENTRAL
ALLEGAN COUNTY THEN WEST OVER LAKE MICHIGAN. AS THE NEXT SHORTWAVE
MOVES INTO THE AREA INVERSION HEIGHTS RISE TO 10000 FT AND WITH
850 MB TEMPS NEAR -8C WHILE EASTERN LAKE MICHIGAN WATER
TEMPERATURES ARE STILL NEAR 11C... THAT WILL BE MORE THAN NEEDED
TO RESULT IN LAKE EFFECT SHOWERS FROM NOW THROUGH MIDNIGHT OR SO.
THE BIG QUESTION IS WHAT WILL THE PRECIPITATION TYPE BE? AT THE
START THE AIR IS WARM ENOUGH TO BE RAIN... BUT INLAND OF US-31
AFTER SAY 8 PM OR SO IT MAY JUST BE COLD ENOUGH OF SNOW TO REACH
THE GROUND. GIVEN AIR TEMPS SHOULD REMAIN ABOVE FREEZING I DO NOT
SEE ACCUMULATIONS AMOUNTING TO MORE THAN AN INCH OR SO ON GRASSY
SURFACES BUT THE RAP MODEL DOES GIVE NEARLY .30 OF IN OF QPF OVER
SOUTHERN VAN BUREN COUNTY. MOSTLY BETWEEN 8 PM AND 1 AM. THE WET
BULB ZERO HEIGHTS ARE NEAR 1000 AGL BY THEN SO IT JUST MAY END UP
BEING SNOW. WE WILL HAVE TO WATCH THIS. FOR NOW I HAVE TRACE
AMOUNTS OF SNOW IN THE GRIDS.
ONCE THIS SERIES OF SHORTWAVES MOVES EAST SKIES SHOULD FOR THE
MOST PART CLEAR AND HIGH PRESSURE RULES THROUGH FRIDAY.
THE NEXT SYSTEM TRACKS NORTH OF THE CANADIAN BOARDER NEAR LAKE
SUPERIOR FRIDAY NIGHT INTO SATURDAY. THE ISENTROPIC LIFT AHEAD OF
THE WARM FRONT WILL BRING SHOWERS TO THE AREA EARLY SATURDAY
MORNING BUT THE BEST LIFT AND MOISTURE IS NORTH OF I-96 SO THAT IS
WHERE THE HIGHEST POPS ARE. IT SHOULD BE WARM ENOUGH TO BE MOSTLY
RAIN.
THAT WRAPS IN WARMER AIR FOR SATURDAY SO LAKE EFFECT IS OUT OF
PLAY THUS EXPECT PARTLY CLOUDY SKIES FOR THE MOST PART AS SLIGHTLY
WARMER TEMPERATURES.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 344 PM EST THU NOV 7 2013
COLD IS THE OPERATIVE WORD IN THE EXTENDED WITH A BIG ARCTIC HIGH
BRINGING BELOW NORMAL TEMPERATURES FROM TUESDAY THROUGH THURSDAY. NO
BIG STORMS IN THE OFFING BUT SHOWERS OF RAIN MIXED WITH SNOW ARE
EXPECTED MONDAY AND INTO MONDAY NIGHT ALONG THE ARCTIC FRONT.
LAKE EFFECT SNOW BEHIND THE FRONT SHOULD BE LIMITED TO FAR WESTERN
ZONES AS FLOW IS EXPECTED TO BE NORTHERLY AND MAY EVEN GO OFFSHORE
BY TUESDAY NIGHT. THE 12Z GUIDANCE HAS SHIFTED WEST WITH THE PATH OF
THE ANTICYCLONE...BUT THE EURO STILL INDICATES LESS IN THE WAY OF
ONSHORE FLOW THROUGH THURSDAY MORNING AS SFC RIDGING REMAINS STRONG
OVER LOWER MICHIGAN. THIS WOULD MEAN LESS CLOUDS AND COLDER MIN
TEMPS ACROSS THE WESTERN FORECAST AREA THAN THE GFS. MIN TEMPS WERE
LOWERED THURSDAY MORNING TO ACCOUNT FOR THIS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 700 PM EST THU NOV 7 2013
FOR THE MOST PART VFR CONDITIONS ARE GOING TO PREVAIL TONIGHT AND
FRIDAY. BKN-OVC CLOUD BASES TONIGHT WILL BE MOSTLY IN THE 3-5K
FOOT RANGE ALTHOUGH SOME LOWER CIGS/VSBYS ARE LIKELY FROM TIME TO
TIME IN THE LAKE EFFECT RAIN AND SNOW SHOWERS SOUTH OF MKG AND GRR.
ICING IN THE CLOUD LAYER BETWEEN 2K FEET AND 10K FT IS LIKELY
WITHIN ANY OF THESE SHOWERS TONIGHT.
THE LOWER CLOUDS SHOULD SCATTER OUT ON FRIDAY AFTERNOON AS HIGH
PRESSURE MOVES IN AND WARMER AIR ALOFT ENDS THE THREAT OF LAKE
EFFECT CLOUDINESS. A BAND OF MID/HIGH LEVEL CLOUDS WITH BASES AOA
10K FEET IS EXPECTED TO SLIDE IN FROM THE WEST AFTER 18Z FRIDAY.
&&
.MARINE...
ISSUED AT 344 PM EST THU NOV 7 2013
I CONTINUED THE SMALL CRAFT ADVISORY THROUGH TONIGHT AND ISSUED A
GALE WARNING FOR FRIDAY NIGHT DUE TO THE STRONG SOUTHERLY FLOW
OVER LAKE MICHIGAN AHEAD OF THE SYSTEM. LAKE TEMPS OVER THE
EASTERN PART OF LAKE MICHIGAN ARE IN THE LOWER 50S BUT THE
SOUTHERLY WINDS WILL BE BRINGING SURFACE AIR ONLY IN THE 40S OVER
THAT LAKE SO THAT SHOULD BE ENOUGH TO ALLOW ENOUGH MIXING TO BRING
THE 40 TO 50 KNOT WINDS IN THE BOUNDARY LAYER DOWN CLOSE TO THE
LAKE SURFACE. THUS THE GALE WATCH FRIDAY NIGHT.
&&
.HYDROLOGY...
ISSUED AT 344 PM EST THU NOV 7 2013
EVEN WITH THE .5 TO 1.5 INCHES OF RAIN THAT FELL WEDNESDAY THE
RIVERS DID NOT RESPOND MUCH. SO WITH LITTLE IN THE WAY OF
SIGNIFICANT QPF EXPECTED OVER THE NEXT WEEK... I SEE NO SIGNIFICANT
ISSUES WITH AREA RIVERS AND STREAMS ON THE SHORT TERM.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WATCH FROM FRIDAY EVENING THROUGH SATURDAY MORNING FOR
LMZ844>849.
SMALL CRAFT ADVISORY UNTIL 7 AM EST FRIDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...OSTUNO
AVIATION...MEADE
HYDROLOGY...WDM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 PM EST WED NOV 6 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 400 PM EST WED NOV 6 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
HUDSON BAY THROUGH THE WRN GREAT LAKES TO THE SRN PLAINS. PCPN
ASSOCIATED WITH 800-600 MB FGEN AND DEEP LAYER QVECTOR CONV AHEAD OF
THE SHRTWV THROUGH CNTRL UPPER MI WAS QUICKLY EXITING THE CWA INTO
FAR ERN UPPER MI. 850 MB TEMPS TO AROUND -7C(LAKE TEMPS NEAR 8C)
ONLY PROVIDED MARGINAL INSTABILITY FOR ANY LAKE EFFECT PCPN WITH
SUBSIDENCE PREVAILING IN THE WAKE OF THE SHRTWV. RADAR INDICATED
ONLY ISOLATED FLURRIES/SPRINKLES INTO WEST UPPER MI AND S CNTRL LAKE
SUPERIOR.
TONIGHT...CAA DROPPING 850/700 MB TEMPS TO -9C/-15C AND
GRADUALLY CLIMBING INVERSION HEIGHTS WILL FAVOR INCREASE IN LES FOR
WNW FLOW SNOWBELTS. HOWEVER...ONLY MINOR ACCUMULATIONS OF AN INCH OR
LESS ARE EXPECTED FOR HIGHER TERRAIN LOCATIONS IN THE WEST NORTH OF
M-28 AND OVER THE EAST FROM MUNISING AND SHINGLETON EASTWARD.
THURSDAY...300-310 LOW LEVEL FLOW LES WILL CONTINUE AND MAY INCREASE
ESPECIALLY OVER THE EAST HALF AS A WEAK 850-700 MB TROUGH BRUSHES
THE ERN LAKE WITH CLIMBING INVERSION HEIGHTS(AN INCREASE IN 850-700
MB MOISTURE AND 700 MB TEMPS TO NEAR -18C). EVEN WITH NMRS
SHSN...EXPECT ONLY LIGHT ACCUMULATIONS OF AN INCH OR LESS AND A
RAIN/SNOW MIX AS SFC TEMPS CLIMB INTO THE MID TO UPPER 30S BY
AFTERNOON. OVER THE WEST...SOME LIGHT ACCUMULATIONS MAY ALSO BE
POSSIBLE BUT WILL BE LIMITED BY THE SHORTER FETCH LENGTH AND LESS
FAVORABLE LOW LEVEL CONVERGENCE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 400 PM EST WED NOV 6 2013
FOR THU NIGHT WILL INITIALLY SEE SLIGHTLY CYCLONIC NW WINDS ACROSS
LAKE SUPERIOR AS A WEAK SHORTWAVE WILL BE OVER THE ERN CWA...BUT
WINDS WILL BECOME INCREASINGLY ANTICYCLONIC THROUGH THE NIGHT AS A
SFC RIDGE MOVES TO THE FAR WRN CWA BY 12Z FRI. 850MB TEMPS WILL
GENERALLY STAY AROUND -8C TO -9C...SO LES IN NORTHWEST WIND
SNOWBELTS IS EXPECTED...ESPECIALLY OVER ERN UPPER MI WHERE THE
LONGER FETCH AND LONGER LASTING LOW LEVEL MOISTURE AND FAVORABLE LOW
LEVEL FLOW WILL BE. SNOWFALL AMOUNTS LOOK RELATIVELY MINOR...BUT
SHOULD BE GREATEST OVER THE NERN CWA WHERE A COUPLE OF INCHES ARE
POSSIBLE.
THE SFC RIDGE AXIS WILL BE E OF THE CWA BY 00Z SAT...CONFINING ANY
REMAINING ISOLATED LES TO NEAR WHITEFISH POINT BY FRI EVENING. SOME
PRECIP MAY BE MOVING INTO THE FAR WRN CWA BY 00Z SAT AHEAD OF A
SHORTWAVE THAT THE 12/06 GFS AND 00Z/06 ECMWF SHOW MOVING FROM ERN
SD AT 00Z SAT TO NRN LAKE MICHIGAN AT 12Z SAT THEN TO ONTARIO E OF
LAKE HURON BY 18Z SAT. AT THE SAME TIME...A MORE SUBSTANTIAL
SHORTWAVE WILL MOVE OVER THE SRN MANITOBA/ONTARIO BORDER. AHEAD OF
THE STRONGER SHORTWAVE IS WHERE THE SFC LOW WILL ORGANIZE...WITH A
SFC TROUGH EXTENDING SE TO THE WEAKER SHORTWAVE. STILL SOME MODEL
DISAGREEMENT ON THE STRENGTH/TRACK OF THE SHORTWAVES /MAINLY THE
WEAKER ONE/ SO CONFIDENCE IS SOMEWHAT LIMITED. DO AGREE WITH PREVIOUS
FORECASTER THAT LIKELY POPS ARE JUSTIFIED...SINCE MAIN LACK OF
CONFIDENCE IS WITH PTYPE AND EXACT AMOUNTS OF PRECIP. PTYPES LOOK TO
BE MOSTLY SNOW OVER THE WRN CWA /WITH SOME RAIN MIXED IN/ TO MOSTLY
RAIN OVER THE ERN CWA DUE TO WARMER AIR COMING OFF LAKE MICHIGAN.
EVEN THOUGH LOW LEVEL TEMPS WILL INITIALLY BE WARM...THE WARM LAYER
WILL ALSO BE DRY SO WET BULB TEMPS WILL BE SIGNIFICANTLY LOWER.
LOOKS AS THOUGH MOST SYNOPTIC PRECIP WILL BE DONE BY 00Z SUN. THINK
THAT UP TO 2 INCHES OF SNOW IS POSSIBLE OVER THE WRN CWA...BUT STILL
FAIRLY UNCERTAIN ON THAT NUMBER.
AFTER THE TROUGH/COLD FRONT MOVES THROUGH SAT...LOW LEVEL AIR COLD
ENOUGH FOR LES WILL MOVE IN THROUGH AT LEAST SAT NIGHT /MODEL
SOLUTIONS DIVERGE SIGNIFICANTLY AFTER THAT SO ENDING TIME IS VERY
UNCERTAIN/. THINK IT WILL BE A FAIRLY QUICK SHOT OF THE BEST
CONDITIONS AS FLOW BECOMES MORE ANTICYCLONIC THROUGH SAT NIGHT...SO
ACCUMULATIONS SHOULD BE FAIRLY MINOR.
SUN THROUGH NEXT WED IS VERY UNCERTAIN AS MODELS SHOW SIGNIFICANT
RUN TO RUN AND MODEL TO MODEL DISAGREEMENT WITH DETAILS OF UPPER
LEVEL ENERGY. ONE THING THAT DOES LOOK MORE CERTAIN IS THE ARRIVAL
OF MUCH COLDER TEMPS. THE ECMWF IS THE COLDER THAN THE GFS IN
BRINGING 850MB TEMPS OF -15C TO -20C OVER THE CWA FROM MON NIGHT
THROUGH NEXT WED. THE GFS IS COLD AS WELL...BUT NOT AS COLD AS THE
ECMWF...SHOWING 850MB TEMPS OF -10C TO -15C FROM SUN NIGHT THROUGH
NEXT WED. OF COURSE...LES WOULD OCCUR IN THIS SCENARIO DEPENDING ON
WIND DIRECTION...WHICH IS VERY UNCERTAIN...AND SYNOPTIC SNOWFALL
WOULD ALSO LIKELY OCCUR AT SOME POINT...BUT THIS IS EVEN MORE
UNCERTAIN. WILL GO WITH GENERAL CONSENSUS OF MODEL GUIDANCE RIGHT
NOW...BUT WILL INCREASE POPS TO AT LEAST CHANCE FOR LES MON NIGHT
INTO TUE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 102 PM EST WED NOV 6 2013
MVFR CIGSS EARLY THIS AFTERNOON ARE EXPECTED TO IMPROVE TO VFR BY
20Z-23Z...HOLDING OUT LONGEST AT CMX...AS MUCH DRIER AIR MOVES IN
FROM THE WEST. GUSTY NORTHWEST WINDS WILL ALSO DIMINISH THIS EVENING
AS HIGH PRES BUILDS TOWARD THE REGION
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EST WED NOV 6 2013
LOW PRESSURE OVER NRN LAKE HURON WILL QUICKLY EXIT INTO
QUEBEC THIS EVENING...LEAVING A TROUGH ACROSS LAKE SUPERIOR THROUGH
EARLY THURSDAY. HIGH PRESSURE ACROSS MUCH OF THE CENTRAL
PORTIONS OF THE NATION WILL TRACK EASTWARD ACROSS THE MISSISSIPPI
VALLEY THURSDAY NIGHT AND FRIDAY...PUSHING A RIDGE OVER LAKE
SUPERIOR. LOOK FOR LOW PRESSURE OVER THE NORTHERN AND CENTRAL PLAINS
ON FRIDAY TO CROSS ONTARIO SATURDAY AND SATURDAY NIGHT...PUSHING A
TROUGH OVER LAKE SUPERIOR ON SATURDAY. WHILE THE LOW DEEPENS OVER
HUDSON BAY...HIGH PRESSURE ACROSS THE NORTHERN AND CENTRAL PLAINS
SATURDAY NIGHT WILL SLOWLY MOVE ACROSS THE UPPER GREAT LAKES ON
SUNDAY. EXPECT INCREASED NW WINDS SATURDAY NIGHT INTO SUNDAY...WITH
GALES OF 35 TO 40KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
348 PM CST WED NOV 6 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 347 PM CST WED NOV 6 2013
MOST INTERESTING THING WITH THE WEATHER TO MONITOR TODAY IS THE
SHRINKING OF THE SNOWPACK LEFT OVER FROM LAST NIGHTS SNOW ON VISIBLE
SATELLITE. AS WE GET INTO THE BACK SIDE OF THE TROUGH THAT BROUGHT
US THIS SNOW...WE ARE SEEING OUR FLOW ALOFT TURN NW. WITH THE NW
FLOW COMES SOME WEAK MID LEVEL SHORTWAVE ENERGY THAT IS DROPPING
SOME CLOUD COVER DOWN ACROSS CENTRAL MN THIS AFTERNOON. OF MORE
CONCERN THOUGH ARE THE LOW CLOUDS ACROSS SE SODAK. THESE CLOUDS HAVE
BEEN DIMINISHING DURING THE DAY...BUT WITH THEM NOW MOVING OVER THE
SNOWPACK...THE DECREASED MIXING THERE WILL LIKELY MEAN WE DO NOT
COMPLETELY LOSE THEM BEFORE THE SUNSETS...SO WILL PROBABLY HAVE THEM
EXPAND IN ONE FASHION OR ANOTHER TONIGHT. THE HRRR MAY BE A LITTLE
AGGRESSIVE...BUT DOES SHOW THESE CLOUDS EXPANDING ACROSS MUCH OF
SOUTHERN MN TONIGHT. HAVE DOWNPLAYED THE FOG POTENTIAL SOME TONIGHT
AS MODELS SHOW ENOUGH OF A GRADIENT REMAINING TONIGHT TO KEEP WINDS
UP AROUND 5 KTS FOR ALL BUT CENTRAL MN...WHICH SHOULD KEEP THINGS
MORE OF A STRATUS THAN A FOG CONCERN. ONLY LEFT SOME PATCHY FOG OVER
THE SW CWA...MORE OR LESS WHERE THE DEEPER SNOWPACK EXISTS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 347 PM CST WED NOV 6 2013
THERE ARE TWO CHANCES FOR PRECIP IN THE EXTENDED. THE FIRST ON
FRIDAY WILL BRING MAINLY RAIN ACROSS THE REGION. THE SECOND WILL BE
MONDAY INTO MONDAY NIGHT...AND THIS WILL BE MAINLY A SNOW EVENT.
EARLY AFTERNOON WATER VAPOR IMAGERY AND GFS 500MB HEIGHTS AND WINDS
SHOWED A TROUGH OFF THE BRITISH COLUMBIA COAST. A SHORTWAVE WITHIN
THIS TROUGH WILL MOVE ACROSS THE MOUNTAIN WEST ON THURSDAY. H850
THETA_E ADVECTION WILL OVERSPREAD THE REGION ON FRIDAY...AND
TOGETHER WITH THE UPPER LEVEL DYNAMICS OF THIS SYSTEM WILL DEVELOP
PRECIP ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. FORECAST SOUNDINGS
STRUGGLE TO SATURATE THE LOWER LEVELS...BUT BASED ON THE FORCING
CONFIDENCE IS HIGH IN MEASURABLE PRECIP...ESPECIALLY NORTH OF
I-94.
THIS FAST MOVING SYSTEM WILL EXIT THE REGION BY SATURDAY...WITH HIGH
PRESSURE BUILDING IN FOR THE WEEKEND. HOWEVER...ANOTHER SHORTWAVE
WILL MOVE ACROSS THE REGION EARLY NEXT WEEK AND BRING CHANCES FOR
SNOW FOR MONDAY AND TUESDAY. AT THIS TIME ONLY HAVE CHANCE
POPS...BUT THE MODELS CONTINUE TO SHOW CONSISTENCY...WITH POTENTIAL
FOR A FEW INCHES OF SNOW BY THE TIME IT MOVES OFF LATE THURSDAY. IF
THIS TREND CONTINUES EXPECT THE POPS TO INCREASE ALONG WITH
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1147 AM CST WED NOV 6 2013
TWO ISSUES THIS TAF PERIOD REVOLVE AROUND 5K-7K FT CLOUDS
CURRENTLY MOVING INTO NW MN AND REMNANT IFR CIGS OVER SE SODAK.
FLOW BETWEEN 5K AND 7K FT WILL BRING THOSE CLOUDS SE INTO THE MPX
AREA...WHILE LOW LEVEL FLOW OUT OF THE WEST WILL BRING LOW LEVEL
MOISTURE INTO SRN MN BY TONIGHT. CURRENTLY FAVOR THE IDEA OF THE
RAP...WHICH HAS THE BKN TO OVC 5K-7K FT CLOUDS WORKING ABOUT AS
FAR SW AS THE MN RIVER AND STAYING IN PLACE THROUGH MOST OF THE
NIGHT. SOUTH OF THESE CLOUDS WILL BE THE POTENTIAL FOR IFR/LIFR
STRATUS TO FORM...WITH RWF HAVING THE BEST POTENTIAL FOR SEEING
THESE CLOUDS...ESPECIALLY GIVEN THE SNOW COVER IN PLACE. SHOULD BE
MAINLY A STRATUS ISSUE TONIGHT...AS GRADIENT LOOKS STRONG ENOUGH
TO MAINTAIN 5 KT WNW WINDS...WHICH SHOULD BE ENOUGH TO KEEP DENSE
FOG FROM FORMING ANYWHERE IN THE MPX AREA.
KMSP...BIGGEST QUESTION MARK FOR TAF REVOLVES AROUND CLOUDS
CURRENTLY NORTHWEST OF THE FIELD THAT WILL BE HEADING THIS
DIRECTION THIS AFTERNOON. MAIN QUESTION WITH THEM IS HOW LONG DO
THEY HANG AROUND. NAM INDICATES THAT ONCE THEY MOVE IN...THEY ARE
WITH US THROUGH THE REST OF THE TAF. IF THAT HAPPENS...THEN
STRATUS/FOG WILL NOT BE AN ISSUE TONIGHT. WITH THAT CLOUD
UNCERTAINTY...REMOVED THE MVFR VIS WE HAD GOING THU MORNING.
/OUTLOOK FOR KMSP/
FRI...CHC FOR MVFR CIGS AND -RA. WINDS SE 15G25 KTS.
SAT...VFR. WINDS W 10-15 KTS.
SUN...VFR. WINDS BCMG S 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JRB
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1100 PM CST TUE NOV 5 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 338 PM CST TUE NOV 5 2013
COLD FRONT THAT SWEPT ACROSS THE AREA YESTERDAY HAS BECOME A WARM
FRONT THIS AFTERNOON THAT STRETCHES FROM A 1010 MB SFC LOW OVER THE
OK PANHANDLE NORTHEAST TO ABOUT SHEBOYGAN IN WISCONSIN. SPLAYED WEST
TO EAST ACROSS THE CENTER OF THE MPX CWA IS 1025 MB RIDGE OF HIGH
PRESSURE. WE HAVE SEEN SOME VERY DRY AIR BUILD IN AT THE SFC WITH
THE HIGH...WITH DEW POINTS ACROSS WRN/CENTRAL MN DOWN INTO THE UPPER
TEENS TO LOWER 20S. A 0.5 DEG REFLECTIVITY IMAGE AT 21Z SHOWS THE
IMPACT OF THIS DRY LOW LEVEL AIR...WITH A NICE DONUT HOLE AROUND THE
MPX RADAR. HOWEVER...REFLECTIVITY SOUTH AND WEST OF THE RDA IS LOWER
THAN IT IS EAST AND NORTHEAST...SO YOU CAN GET THE SENSE OF HOW THE
ATMOSPHERE IS QUICKLY MOISTENING SOUTH AND WEST OF THE TWIN CITES.
REGIONAL RADAR RIGHT NOW SHOWS TWO ENHANCED AREAS OF REFLECTIVITY
THIS AFTERNOON AND MOST MODELS SHOW THIS CURRENT TREND OF TWO
ENHANCED AREAS OF QPF CONTINUING THROUGH MUCH OF THE EVENT. ONE AREA
CAN BE BEST DESCRIBED AS A BLOB OF PRECIPITATION THAT CAN BE FOUND
AT 21Z ACROSS MOST OF IOWA. THIS IS ON THE NOSE OF THE LLJ AND ITS
ASSOCIATED THE MAIN MOISTURE SURGE. THE SECOND IS A BAND OF RADAR
RETURNS THAT STRETCHES FROM NEAR NORTH PLATTE IN CENTRAL
NEB...NORTHEAST THROUGH SIOUX FALLS AND CONTINUES ON COMPOSITE
REFLECTIVITY NORTHEAST TO REDWOOD FALLS/BUFFALO/CAMBRIDGE AND
EVENTUALLY OVER TO THE SPOONER WI AREA. THIS IS IN ASSOCIATION WITH
ENHANCED FGEN ALONG WITH SOME CSI CENTERED AROUND 700 MB. YOU CAN
SEE THE IMPACTS OF THESE TWO PIECES OF FORCING IN SEVERAL OF THE
HI-RES MODELS. FOR INSTANCE...THE 05.18 HRRR SHOWS QPF OF 0.75-1.00
INCHES ACROSS SE MN WITH THE MAIN MOISTURE SURGE...A LULL IN TOTAL
QPF FROM MANKATO UP THROUGH HASTINGS WHERE ONLY A QUARTER INCH OF
QPF IS INDICATED...WITH THE CSI BAND SHOWING UP FROM REDWOOD FALLS
THROUGH MINNEAPOLIS AND UP TOWARD RICE LAKE WHERE RUN TOTAL QPF IS
UP MORE IN THE 0.5 INCH RANGE THANKS TO THE ENHANCED FGEN/CSI
FORCING. FOR THE WINTER WEATHER ADVISORY...IT IS WHERE THIS FGEN
BAND SETS UP THAT WILL RESULT IN THE 3-5 INCH SNOWFALL TOTALS THAT
ARE EXPECTED.
COUPLE OF THINGS THAT MAKE THIS SNOWFALL FORECAST DIFFICULT ARE
NARROW NATURE OF THE EXPECTED FGEN BAND /NOT MUCH MORE THAN 50 MILES
WIDE/ ALONG WITH HOW QUICKLY DO THE LOW LEVELS OF THE ATMOSPHERE COOL TO
ALLOW RAIN TO CHANGE TO SNOW. ALTHOUGH WE ARE SEEING MANY PLACES IN
THE TWIN CITIES WITH TEMPS IN THE 40S...IT IS THOSE DEW POINTS AND
THE ATTENDANT WET BULB TEMPERATURES THAT YOU REALLY NEED TO PAY
ATTENTION TO. BECAUSE OF THE DRY AIR...SFC WEB BULB TEMPS ARE IN THE
LOW TO MID 30S...WHICH MEANS AS THE PRECIP EVAPORATES WE WILL
QUICKLY SEE TEMPS FALL OFF TO NEAR THE FREEZING MARK...WITH A RAPID
CHANGEOVER TO SNOW EXPECTED WEST OF A BLUE EARTH/WASECA/LADYSMITH
LINE SHORTLY AFTER RAIN BEGINS. EAST OF THIS LINE...DEWPS ARE STILL
MAINLY IN THE MID 30S. A GOOD EXAMPLE OF THIS RAPID CHANGEOVER WAS
LITCHFIELD...WHICH FIRST REPORTED RAIN AT 230 PM AND WAS ALREADY
REPORTING SNOW 20 MINUTES LATER.
THE SPREAD AMONGST THE MODELS FOR WHERE THE 3-5 INCH BAND SETS UP
WAS NOT ALL THAT LARGE...RANGING ON THE 05.12 RUNS FROM BEING
CENTERED ALONG THE HENNEPIN/DAKOTA COUNTY LINE WITH THE NAM AND MORE
ALONG THE HENNEPIN/WRIGHT COUNTY LINE WITH THE GFS/GEM.
HRRR/HOPWRF/MPXWRF/ECMWF BASICALLY SPLIT THE DIFFERENCE BETWEEN THE
TWO...AND THE CURRENT FORECAST FAVORS A BLEND OF THESE MODELS. THE
ONE AREA IT LOOKS LIKE WILL NEED TO BE WATCHED FOR POSSIBLE WARNING
TYPE SNOW /GREATER THAN 6 INCHES/ IS SW MN...WHERE THE SNOW IS
ALREADY FLYING AND THE RESIDENCE TIME FOR THE FGEN BAND LOOKS TO BE
THE LONGEST.
HAVE LEFT THE WINTER WEATHER ADVISORY AS IS...THOUGH WOULD SAY THAT
MOST OF MN COULD BE ENDED AROUND 9Z...WITH WI ENDING AT 12Z...ABOUT
3 HOURS AHEAD OF WHAT WE CURRENTLY HAVE.
FOR AS MUCH FUN AS WE ARE GOING TO HAVE WITH THE PRECIP
TONIGHT...WEDNESDAY IS LOOKING QUIET AND BEAUTIFUL...WITH MOSTLY
SUNNY SKIES EXPECTED EVERYWHERE BY THE AFTERNOON. DID FAVOR THE
FORECAST HIGHS FOR TOMORROW TOWARD A BLEND OF THE DETERMINISTIC
MODELS...WHICH RESULTED IN THE COOLEST TEMPS /WITH HIGHS IN THE
UPPER 30S/ ALONG WHERE THE BAND OF SNOW IS EXPECTED FOR TONIGHT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 338 PM CST TUE NOV 5 2013
FOLLOWING WEDNESDAYS SYSTEM...ANOTHER WEAK CLIPPER SYSTEM RIDES
SOUTHEAST IN THE NORTHWEST FLOW OVER THE AREA WEDNESDAY NIGHT. THIS
WILL PROVIDE A FEW CLOUDS BUT IS EXPECTED TO MOVE THROUGH DRY.
HIGH PRESSURE WILL DOMINATE THE WEATHER FOR THURSDAY...WITH SOME
SUNSHINE AND NEAR NORMAL TEMPERATURES.
MORE ZONAL FLOW REGIME DEVELOPS AND ANOTHER FAST MOVING TROUGH
MOVES INTO THE AREA FOR FRIDAY INTO SATURDAY. THE 12Z ECMWF IS
MORE AMPLIFIED WITH THIS TROUGH WHILE THE GFS IS LESS SO AND
FARTHER NORTH. THE ECMWF HAS BEEN MORE CONSISTENT WITH THE DEEPER
NATURE OF THE TROUGH...SO WILL FOLLOW THIS FOR NOW. STILL
PROVIDES JUST A CHANCE OF MIXED TYPE PRECIPITATION FOR THE
EVENT...MAINLY OVER THE NORTHERN CWA.
LARGE HIGH PRESSURE SYSTEM FOLLOWS THIS TROUGH FOR SUNDAY...WITH
THE GFS AND ECMWF DIVERGING ON OVERALL MOVEMENT OF THE NEXT
WESTERN TROUGH INTO THE CWA. THE ECWMF IS FASTER WITH A STRONG
COLD FRONT SUNDAY NIGHT DRAWING IN MUCH COLDER AIR OVER THE AREA
INTO THE FIRST PART OF NEXT WEEK. THE GFS HOLDS OFF ON THIS COLD
AIR INTRUSION UNTIL WEDNESDAY. STILL TIME TO DECIPHER MODEL TRENDS
WITH THIS OVERALL DEVELOPMENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1032 PM CST TUE NOV 5 2013
SIGNIFICANT IMPROVEMENT TO THE CEILINGS AND VISIBILITIES WILL
OCCUR AT KRWF AND KSTC BY 09Z AS THE BACK EDGE OF THE SNOW MOVES
EAST ALONG WITH WINDS BECOMING NW. THE IMPROVEMENT WILL REACH INTO
THE TWIN CITIES IN THE 10Z-12Z TIME FRAME. CIGS BLO 010 WITH VSBYS
1-3SM -SN WILL BE COMMON OVERNIGTH FOR KRNH AND KEAU WITH
IMPROVEMENT BETWEEN 13Z AND 15Z. THEREAFTER VFR CONDITIONS WILL
PERSIST THROUGH THE END OF THE TAF PERIOD WITH WINDS BACKING TO
THE WSW BY EVENING.
KMSP...MOST INTENSE BAND OF SNOW EXTENDS NE-SW ACROSS THE AIRFIELD
ATTM WITH LIGHTER BANDS TO THE WEST. VSBYS PROBABLY WILL NOT DROP
BELOW 1 1/2SM THROUGH THE DURATION OF THE SNOW EVENT...WHICH IS
EXPECTED TO END AROUND 10Z. CEILINGS BETWEEN 500 AND 800 FEET
BECOMING MVFR AFTER 10Z AND VFR BY 12Z.
/OUTLOOK FOR KMSP/
THU...VFR. WINDS W 5-10 KTS.
FRI...CHC FOR MVFR CIGS AND -RA. WINDS SE 10-15 KTS.
SAT...VFR. WINDS NW 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST WEDNESDAY FOR MNZ051>053-
059>063-065>070-073>078-082>085-091-092.
WI...WINTER WEATHER ADVISORY UNTIL 9 AM CST WEDNESDAY FOR WIZ014>016-
023>025-027.
&&
$$
SHORT TERM...MPG
LONG TERM...DWE
AVIATION...RAH
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1145 PM CST Tue Nov 5 2013
.UPDATE:
Issued at 940 PM CST Tue Nov 5 2013
Tonight`s rain event is unfolding about as expected. Have made
tweaks to bring categorical pops further north and east more
quickly, but the general forecast is about the same. Should see
the rain overspread the rest of the area through the 06-08Z as
moderate to strong isentropic lift continues on the nose of the
low level jet. Am monitoring the line of thunderstorms now in
southeast Kansas to possibly bring thunder to the southern 1/2 of
the CWFA. RAP forecasts up to 100 J/kg MUCAPE moving in ahead of
the front so I can`t rule it out. However, lightning strikes are
relatively few and far between right now and am thinking that
ongoing rain will be enough to dampen any instability. Will leave
mention of thunder out for now and continue to monitor.
Carney
&&
.SHORT TERM: (Through Wednesday)
Issued at 205 PM CST Tue Nov 5 2013
Main shield of rain from this morning has lifted north as
forecast, with only small batches of light rain and sprinkles
streaming northeast within the warm sector. Low pressure currently
located in north central Kansas will continue to advance northeast
along the stalled front into Iowa and Wisconsin tonight. Trailing
cold front will sweep east across Missouri and Illinois late
tonight and Wednesday with a period of rain and falling
temperatures expected.
CVKING
.LONG TERM: (Wednesday Night through Next Tuesday)
Issued at 205 PM CST Tue Nov 5 2013
Pattern flattens out in the wake of this system with a dry and
seasonal forecast remaining in tact despite a frontal passage on
Saturday. Precipitation chances may eventually increase next week
if better moisture can return ahead of a front poised to move
across the Midwest on Monday.
CVKING
&&
.AVIATION: (For the 06z TAFs through 06z Wednesday Night)
Issued at 1128 PM CST Tue Nov 5 2013
MVFR/IFR cigs draped across the w 2/3 of Missouri this evening
have made very little ewd progression...with the leading edge of
these lower conditions remaining q-stationary near a KUNO-KUIN
line. Still expecting a general deterioration of conditions across
the CWA overnight as several more waves of showers push across the
region, but it may take several more hours before prevailing MVFR
conditions settle into STL metro area. Have attempted to tie
prevailing IFR cigs/vsbys to the time frame closer to fropa at
most locations. In addition, weakening convection has managed to
creep into west central MO, and believe some of this could reach
KCOU over the next few hours. Given the recent decease in
lightning strikes not certain how much of a thunder threat there
will be elsewhere, so Will let oncoming shift monitor trends to
determine if thunder should be added at other TAF locations in
later updates.
00z guidance continues to support thinking that there should be a
rapid improvement in conditions beginning several hours after
fropa, as increasing northwest winds end precip and begin
advecting in drier air that should erode low cloudiness.
Specifics for KSTL: Several rounds of light rain should cause
prevailing cigs and vsbys to dip into MVFR category during the
predawn hours and persist into early Wednesday morning, with a brief
drop to IFR cigs/vsbys occurring around the 15z fropa. A rapid
improvement should then begin several hours after fropa, with low
end MVFR cigs by midday, with these ceiling then lifting during
the afternoon and scattering out by early Wednesday evening.
Truett
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
243 PM CST WED NOV 6 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 242 PM CST WED NOV 6 2013
THE SHORT TERM PERIODS WILL CONTINUE TO FEATURE QUIET/DRY WEATHER
CONDITIONS. STRATUS HAS BEEN SLOW TO ERODE ACROSS THE EASTERN
THIRD OF OUR CWA EARLY THIS AFTN...HOLDING TEMPERATURES IN THE
MID/UPPER 30S...WHILE TO THE WEST IN INSOLATION...TEMPS HAVE CLIMBED
INTO THE 40S. THE LOW CLOUDS WILL CONTINUE TO DISSIPATE
TODAY...WITH AN INCREASE IN SCATTERED MID/HIGH CLOUDS INTO
THURSDAY.
A SUBTLE SFC TROUGH WILL CROSS OUR REGION THIS EVENING AS ENERGY
TRANSLATES ACROSS THE UPPER MIDWEST REGION...BEHIND THE TROUGH SFC HIGH
PRESSURE WILL WEAKEN AS IT BUILDS EAST OF THE ROCKIES AND SETTLES ON
TO THE PLAINS FOR THURSDAY. OF NOTE IS THAT THE SREF IS INDICATING
SOME POTENTIAL FOR FOG DEVELOPMENT TONIGHT...BUT THIS IS NOT
SUPPORTED BY THE RAP OR OTHER SHORT TERM MODELS ATTM. HAVE NOT
INCLUDED ANY MENTION IN FCST WITH WESTERLY WIND COMPONENT...VERY
LITTLE SNOWPACK ACROSS OUR CWA AND COLD/SUB FREEZING TEMPS FORECAST
FOR LOWS TONIGHT. THIS BEING SAID...IT IS SOMETHING TO KEEP AN EYE
ON AS WE HEAD INTO TONIGHT.
THURSDAY WILL FEATURE MILDER TEMPS WITH DAYTIME READINGS EDGING
CLOSER TO SEASONAL NORMALS WITH HIGHS IN THE LOW/MID 50S. WINDS
WILL BE FAIRLY LIGHT WITH SFC RIDGE IN PLACE.
.LONG TERM...(THURSDAY EVENING THROUGH WEDNESDAY)
ISSUED AT 242 PM CST WED NOV 6 2013
IN TERMS OF FORECAST CONFIDENCE IN BASIC ELEMENTS SUCH AS
TEMPERATURES/POPS...THIS 6-DAY PERIOD IS CURRENTLY A SPLIT
DECISION...FEATURING RATHER HIGH CONFIDENCE IN DRY AND SEASONABLY
WARM WEATHER THROUGH THE WEEKEND...BUT THEN CONSIDERABLY LOWER
CONFIDENCE ESPECIALLY REGARDING TEMPERATURES DURING THE MON-WED
TIME FRAME. AT ANY RATE...THE ONLY PERIODS CURRENTLY FEATURING
ONLY SLIGHT...STILL-HIGHLY UNCERTAIN CHANCES OF PRECIP ARE TUESDAY
IN THE EAST/SOUTH AND THEN WEDNESDAY ALL AREAS.
GETTING INTO GREATER DETAIL AND STARTING WITH THURSDAY
EVENING/NIGHT...UPPER FORCING REMAINS NEGLIGIBLE LOCALLY AS THE AREA
LIES IN BETWEEN A NORTHEAST CONUS LARGE-SCALE TROUGH AND AN
UPSTREAM SHORTWAVE TROUGH CROSSING THE NORTHERN ROCKIES.
HOWEVER...AM EXPECTING A FAIR AMOUNT OF PASSING MID-HIGH LEVEL
CLOUDS. AT THE SURFACE...THE EFFECT OF THE UPSTREAM DISTURBANCE WILL
BE HIGH PLAINS PRESSURE FALLS...WHICH WILL INDUCE A GRADUALLY
INCREASING SOUTHERLY WIND AS THE NIGHT WEARS ON...WITH MOST AREAS
10+ MPH AFTER MIDNIGHT. THE PASSING CLOUDS AND BREEZES SHOULD KEEP
TEMPS FROM FALLING TOO SHARPLY...AND KEPT LOWS A FEW DEGREES ABOVE
A BLEND OF 12Z MET/MAV GUIDANCE BUT DID NUDGE DOWN SLIGHTLY FROM
PREVIOUS FORECAST...AIMING MOST PLACES BETWEEN 32-35 AND SOME
UPPER 20S IN THE VALLEY/GREELEY/WESTERN DAWSON COUNTY AREA.
ALTHOUGH AM NOT EXPECTING MAJOR ISSUES WITH FOG DEVELOPMENT THANKS
TO INCREASING BREEZES...WILL HAVE TO KEEP AN EYE ON FAR NORTHERN
AREAS WHERE SNOW MELT WILL BE ONGOING BETWEEN NOW AND THEN.
FRIDAY/FRIDAY NIGHT...INCREASED SKY COVER PERCENTAGES FOR THE
DAYTIME HOURS...AND MAYBE NOT ENOUGH...AS AGAIN EXPECT PLENTY OF
PASSING MID-HIGH LEVEL CLOUDS ALONG THE SOUTHERN PERIPHERY OF THE
QUICK-MOVING SHORTWAVE TROUGH WILL TRACK FROM THE MT/WY AREA ON
SUNRISE FRIDAY...ALL THE WAY TO LAKE MICHIGAN BY SUNRISE SATURDAY.
AT THE SURFACE...THE DAYTIME HOURS CONTINUE TO LOOK RATHER BREEZY
ACROSS MAINLY THE SOUTHEAST HALF OF THE CWA...WITH SUSTAINED
SOUTH-SOUTHWEST SPEEDS AROUND 20 MPH GUSTING TO AROUND 30
MPH...WHILE WESTERN AREAS WILL REMAIN GENERALLY 5-10 MPH LIGHTER
IN CLOSER PROXIMITY TO A SURFACE TROUGH. FORTUNATELY FOR FIRE
WEATHER CONCERNS...EVEN IN THE WINDIER SOUTHEAST RELATIVE HUMIDITY
VALUES ARE FORECAST TO HOLD UP IN THE 25-30 PERCENT RANGE...OR
5-10 PERCENT ABOVE CRITICAL LEVELS. TEMP-WISE...DESPITE HIGH
CLOUDS EXPECT A NICE UPWARD BUMP FROM THURSDAY HIGHS. HAVE AIMED MOST
OF THE CWA INTO THE UPPER 50S-LOWER 60S RANGE...WITH MID 60S MOST
FAVORED IN KS ZONES AND THE DAWSON-FURNAS CORRIDOR IN THE WEST.
IN THESE WESTERN ZONES THIS IS ABOUT A 5-DEGREE UPWARD BUMP FROM
PREVIOUS FORECAST. ON FRI NIGHT...A VERY WEAK COLD FRONT NUDGES
INTO THE THE CWA...SIGNALED BY LITTLE MORE THAN A SHIFT TO FAIRLY
LIGHT NORTHERLY BREEZES. AGAIN...SUPPOSE SOME FOG DEVELOPMENT
CANNOT BE RULED OUT ESPECIALLY IN NORTHERN AREAS DUE TO
CONTRIBUTION FROM MELTED SNOW...BUT AT THIS TIME BELIEVE VISIBILITY
PRODUCT FORECASTS FROM THE NAM/SREF ARE OVER-DOING THINGS...AND
WILL LEAVE THE FORECAST FOG-FREE FOR NOW. CHANGED FRIDAY NIGHT
LOWS LITTLE WITH MOST PLACES MID-30S.
SATURDAY DAYTIME THROUGH SUNDAY NIGHT...DRY WEATHER PERSISTS WITH
GENERALLY SUNNIER CONDITIONS COMPARED TO FRIDAY. IN THE MID-UPPER
LEVELS...LOW AMPLITUDE RIDGING WILL DOMINATE MUCH OF THE
CENTRAL/WESTERN CONUS AS THE PRIMARY UPPER JET CORE AND ASSOCIATED
TRACK OF SHORTWAVE TROUGHS REMAINS WELL TO THE NORTH ALONG THE
U.S./CANADA BORDER. ON SATURDAY...BREEZES WILL AVERAGE ONLY AROUND
10 MPH FROM THE NORTH...AND THEN TURNING SOUTHERLY AGAIN FOR
SUNDAY. MADE LITTLE CHANGE TO TEMPS...WITH SATURDAY HIGHS RANGING
FROM LOW 50S FAR NORTH TO NEAR 60 SOUTH...AND SUNDAY MID-UPPER 50S
AREA-WIDE.
MONDAY-WEDNESDAY OF NEXT WEEK...CONFIDENCE IN FORECAST DETAILS
STEADILY DECREASES ALTHOUGH THAT BEING SAID...NO MAJOR
PRECIPITATION EVENTS APPEAR IN STORE. MONDAY-MONDAY NIGHT...THE
OFFICIAL FORECAST REMAINS DRY. IN THE MID-UPPER LEVELS...FLOW
TURNS MORE NORTHWESTERLY IN RESPONSE TO A BUILDING WESTERN CONUS
RIDGE. TEMPS ARE THE BIG QUESTION MARK. ALTHOUGH THE DEFAULT
MULTI-MODEL BLEND HAS PROVIDED WIDESPREAD 50S FOR HIGHS IN MOST
AREAS TO THE OFFICIAL FORECAST...THE LATEST ECMWF SOLUTION
PROVIDES A STRONGER COLD FRONTAL PUSH...WITH HIGHS ABOUT 5-10
DEGREES COLDER MAINLY IN THE 40S. THERE ARE ALSO HINTS OF SOME LOW
STRATUS...WHICH COULD RESULT IN SOME NUISANCE LIGHT DRIZZLE...SO
THIS BEARS WATCHING. GETTING INTO TUESDAY/TUESDAY NIGHT...THE 12Z
ECMWF/GFS ARE IN SURPRISINGLY GOOD AGREEMENT REGARDING A SHORTWAVE
TROUGH DIVING SOUTHEAST OVER THE LOCAL AREA ALONG A TRACK FROM THE
NORTHERN ROCKIES/NORTHERN PLAINS TO EASTERN KS/MO. HOWEVER...THE
BULK OF PRECIPITATION WITH THIS WAVE IS CURRENTLY SLATED TO PASS
JUST EAST AND/OR SOUTH OF THE CWA. ALTHOUGH SOME GENERALLY
LIGHT...NUISANCE PRECIP POSSIBLY IN THE FORM OF DRIZZLE COULD
OCCUR ALMOST ANYWHERE DURING THIS TIME...STUCK WITH THE
INITIALIZED BLENDED FORECAST FOR NOW...WHICH KEEPS LIGHT RAIN ONLY
IN FAR EASTERN ZONES DURING THE DAY...AND THEN NO MENTION OF
PRECIP TUESDAY NIGHT. TEMP-WISE TUESDAY...AGAIN LOW CONFIDENCE
REGARDING HIGHS...AS THE OFFICIAL FORECAST IS MID 40S TO MID
50S...WHILE THE LATEST ECMWF CAME IN 5-10 DEGREES COLDER THAN
THIS. FOR WEDNESDAY DAYTIME...HAVE A SLIGHT CHANCE OF RAIN OR
RAIN/SNOW IN ALL AREAS...BUT THIS WAS LARGELY BASED OFF THE 00Z
ECMWF...AND ITS WORTH NOTING THAT THE LATEST RUN HAS COME IN DRY
AS THE AFOREMENTIONED SHORTWAVE TROUGH TAKES THE MAJORITY OF
FORCING SOUTHEAST OF THE AREA WITH IT. THERE IS DECENT CONFIDENCE
THAT TEMPS WEDNESDAY WILL TAKE A COLDER TURN...ITS JUST A MATTER
OF HOW MUCH SO. THE OFFICIAL FORECAST AIMS FOR A MID 30S-LOW 40S
RANGE IN MOST SPOTS...BUT THE LATEST ECMWF IS COLDER WITH MID 30S
MOST ALL PLACES. PLENTY TO SORT OUT HERE IN THE DAY 5-7 PERIOD.
&&
.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1115 AM CST WED NOV 6 2013
BORDERLINE IFR TO MVFR CLOUDS WILL DEPART THE TERMINAL IN THE NEXT
COUPLE OF HOURS. CLOUDS THEREAFTER WILL BE AT VFR LEVELS. LOOK FOR
WINDS TO REMAIN FROM A WESTERLY TO NORTHWESTERLY DIRECTION.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...PFANNKUCH
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1136 PM CST TUE NOV 5 2013
.UPDATE...
ISSUED AT 813 PM CST TUE NOV 5 2013
AS OF 02Z...RADAR RETURNS FROM KUEX INDICATE LITTLE IF ANY
PRECIPITATION IS OCCURRING ACROSS OUR CWA. WATER VAPOR IMAGERY AND
RAP DATA SUGGEST THE 700MB MID LEVEL SHORTWAVE TROUGH AXIS IS
DIRECTLY OVERHEAD OUR CWA AT THIS HOUR...AND QUICKLY DEPARTING TO
THE NORTHEAST. RADAR DATA FROM KLNX DOES INDICATE LIGHT
PRECIPITATION OVER NORTH CENTRAL NEBRASKA...THE RESULT OF SUBTLE
MID LEVEL DEFORMATION TO THE NORTHWEST OF THE MID LEVEL TROUGH
AXIS. SOME OF THIS ACTIVITY COULD BRIEFLY MOVE ACROSS NORTHERN
PORTIONS OF OUR CWA IN THE FORM OF LIGHT SNOW THROUGH 06Z. THAT
BEING SAID...VERY LITTLE IF ANY SNOW ACCUMULATION IS EXPECTED WITH
THIS ACTIVITY AND AS A RESULT...THE WINTER WEATHER
ADVISORY...WHICH WAS IN EFFECT ACROSS OUR EXTREME NORTHWEST...WAS
CANCELLED.
UPDATED FORECAST GRIDS TO REMOVE POPS THROUGH THE REMAINDER OF THE
NIGHT. THE GOING FORECAST WAS IN GREAT SHAPE OTHERWISE...WITH ONLY
A FEW ADDITIONAL TWEAKS MADE TO HOURLY
TEMPERATURE...SKY...WIND...AND DEW POINT GRIDS TO BETTER REFLECT
CURRENT OBSERVATIONS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 255 PM CST TUE NOV 5 2013
THE PRECIPITATION EVENT TODAY IS GENERALLY UNFOLDING AS EXPECTED
WITH WIDESPREAD RAINFALL DURING THE MORNING...AND A CHANGE TO SNOW
IN OUR W/NW BY MID/LATE MORNING. SEVERAL LOCATIONS PICKED UP AT
LEAST ONE HALF OF AN INCH WHILE OTHER REPORTS OF OVER ONE INCH
HAVE BEEN RECEIVED. THE RAIN HAS MIXED WITH AND MADE THE SWITCH TO
SNOW FROM ROUGHLY THE GOTHENBURG AREA NORTHEASTWARD TO
ARCADIA/ORD/GREELEY EARLY THIS AFTERNOON.
THE RAP HAS BEEN HANDLING THE ONGOING/SHORT TERM TIME FRAME WELL AND
HAVE FOLLOWED CLOSE TO THIS THROUGH THE EVENING. THE MID LEVEL
TROUGH WILL CONTINUE TO TRANSLATE EASTWARD ACROSS THE INTERIOR CONUS
THROUGH THE REMAINDER OF THE AFTN/EARLY EVENING. ISENTROPIC LIFT
AHEAD OF THE SYSTEM WILL SHIFT EASTWARD DURING THE NEXT SEVERAL
HOURS WITH MAIN RAIN AREA SHIFTING OFF TO THE EAST ACROSS EASTERN KS
AND NEB. THE MID LEVEL H7 CIRCULATION TENDS TO INTERMITTENTLY CLOSE
AS IT LIFTS TO NORTHEAST NEBRASKA WITH THE MAIN SNOW BAND/PSEUDO
DEFORMATION REMAINING TO THE WEST/NORTHWEST OF OUR CWA. THIS BEING
SAID...A FRONTOGENETIC BAND OF PCPN IS STILL EXPECTED INTO THE EVENING
AS THE COLD FRONT ADVANCES SOUTHEASTWARD.
AS THE COLDER AIR WORKS SOUTH...THE LINGERING RAIN WILL MIX WITH
AND/OR CHANGE TO SNOW WITH THE TRANSITION TO ALL SNOW EXPECTED TO
AFFECT LOCATIONS WEST OF A LINE FROM GENOA TO HASTINGS TO
FRANKLIN FOR A BRIEF TIME. THE GREATER SNOW ACCUMULATIONS WILL
REMAIN ACROSS OUR NW/W CWA...WHERE CURRENTLY A WINTER WEATHER
ADVISORY IS IN EFFECT UNTIL MIDNIGHT. SNOWFALL IN THE ADVISORY
AREA IS EXPECTED TO RANGE FROM 1 TO 3 INCHES...MAINLY ON GRASSY
SURFACES AND LOCALLY HIGHER AMOUNTS CANNOT BE RULED OUT IF A SNOW
BAND SETS UP THIS EVENING. THE LAST SNOW REPORT RECEIVED FROM THE
ORD AREA EARLY THIS AFTERNOON HAD A SNOW ACCUMULATION OF JUST OVER
ONE INCH. OUTSIDE OF THE ADVISORY AREA...LITTLE IF ANY SNOW
ACCUMULATION IS EXPECTED.
THE SNOW WILL RAPIDLY WIND DOWN DURING THE EVENING BEHIND THE
PASSING MID LEVEL TROUGH AXIS. HAVE ENDED PCPN BY 06Z...BUT OUR FAR
NORTH MAY SEE A FEW FLURRIES FOR AN HOUR OR SO.
DRY AND COOLER CONDITIONS ARE FORECAST FOR WEDNESDAY IN THE WAKE OF
THIS SYSTEM.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 255 PM CST TUE NOV 5 2013
WEDNESDAY NIGHT THROUGH TUESDAY. MAIN CONCERN WILL BE
TEMPERATURES THROUGH PERIOD AND IF THERE WILL BE ANY PRECIPITATION
NEXT TUESDAY.
NORTHWEST FLOW WILL START THE PERIOD WITH A GRADUAL TRANSITION TO
ZONAL FLOW TOWARD THE WEEKEND. THERE ARE VERY FEW UPPER LEVEL WAVES
EXPECTED TO MOVE THROUGH THE AREA.
AT THE SURFACE THERE IS A HIGH PRESSURE SYSTEM FOR WEDNESDAY NIGHT
INTO THURSDAY THAT WILL MOVE TO THE EAST THURSDAY NIGHT. EXPECT DRY
CONDITIONS WITH COOL TEMPERATURES WEDNESDAY NIGHT AND THURSDAY. WHEN
THE SURFACE HIGH MOVES OFF TO THE EAST THURSDAY NIGHT THERE IS A
LITTLE WARM ADVECTION AND TEMPERATURES WILL BE A LITTLE WARMER FOR
THURSDAY NIGHT. THE WARMER TEMPERATURES WILL CONTINUE INTO
FRIDAY...BUT WILL BE TEMPERED BY BREEZY CONDITIONS. THE PRESSURE
GRADIENT TIGHTENS ON FRIDAY AND WITH WINDS ALOFT OF OVER 40 KTS
EXPECT AT LEAST BREEZY CONDITIONS.
A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA FRIDAY NIGHT AND
BRING A LITTLE BIT COOLER TEMPERATURES TO THE AREA FOR SATURDAY AND
SUNDAY.
EARLY NEXT WEEK THERE ARE VARYING SOLUTIONS WITH REGARD TO WHAT IS
EXPECTED. BOTH THE GFS AND THE ECMWF HAVE NEARLY ZONAL FLOW. WITH
SOUTH WINDS THE GFS BRINGS ADDITIONAL MOISTURE INTO THE AREA AND
WITH WARM ADVECTION THERE COULD BE SOME LIGHT RAIN ON TUESDAY. THE
ECMWF ON THE OTHER HAND HAS EAST WINDS AND KEEPS THE MOISTURE TO THE
SOUTH OF THE FORECAST AREA AND DRY CONDITIONS. HAVE WENT A LITTLE
CLOSER TO THE GFS AT THIS TIME AND HAVE A LITTLE LIGHT RAIN MAINLY
IN THE SOUTHEAST PART OF THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1126 PM CST TUE NOV 5 2013
MAIN FORECAST CONCERN LIES WITH LOW LEVEL STRATUS THROUGH THE
REMAINDER OF THE OVERNIGHT HOURS. MANY AREA OBS SHOWING MVFR
CEILINGS REMAINING IN PLACE...AND EXPECT THAT CONTINUE FOR AT
LEAST A FEW MORE HOURS...BUT THOSE CLOUDS SHOULD DRIFT EAST WITH
TIME. ONCE THEY DO...VFR CONDITIONS ARE FORECAST. NORTHWESTERLY
WINDS CURRENTLY IN PLACE WILL GRADUALLY BECOME MORE WESTERLY THIS
MORNING...WITH THOSE WESTERLY WINDS REMAINING IN PLACE THROUGH THE
END OF THE PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...BRYANT
SHORT TERM...FAY
LONG TERM...JCB
AVIATION...ADO
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1128 PM CST TUE NOV 5 2013
.AVIATION...06Z TAFS FOR KOFK...KLNK AND KOMA.
IFR CIGS WILL LINGER ACROSS EASTERN NEBRASKA INTO THE MORNING WITH
SOME IMPROVEMENT ABOVE FL010 BETWEEN 14Z AND 18Z. A BAND OF
DRIZZLE WILL AFFECT KOMA AND KLNK THROUGH 10-12Z...DROPPING VSBYS
TO 3 MILES AT TIMES. GUSTY NORTHWEST WINDS 15 TO 25KT WILL
GRADUALLY DIMINISH THROUGH THE MORNING AS WELL. EXPECT VFR
CONDITIONS AND CLEARING SKIES AFTER 20Z.
DERGAN
&&
.PREV DISCUSSION... /ISSUED 900 PM CST TUE NOV 5 2013/
UPDATE...
WITH SNOW PRETTY MUCH DISSIPATING ACROSS NORTHEAST NEBRASKA...HAVE
CANCELLED THE WINTER WEATHER ADVISORY. THERE COULD BE SOME LIGHT
SNOW THERE LATER THIS EVENING OR OVERNIGHT AS DEFORMATION ZONE
ROTATES IN FROM NORTH CENTRAL NEBRASKA...BUT WOULD EXPECT THIS
AREA TO DIMINISH AS IT MOVES EAST. ALSO...ADDITIONAL AMOUNTS
SHOULD BE MINIMAL.
DERGAN
PREV DISCUSSION... /ISSUED 303 PM CST TUE NOV 5 2013/
SHORT TERM...TONIGHT THROUGH FRIDAY.
UPPER TROUGH TO OUR WEST CONTINUES TO WORK SLOWLY EAST PER
AFTERNOON STLT IMAGERY. THIS SYSTEM HAS BEEN VERY EFFICIENT IN
GENERATING PRECIP ACROSS THE FORECAST AREA TODAY...SOME LIQUID
AMOUNTS HAVE PUSHED PAST 1 INCH...AS IT PRODUCED DECENT
FRONTOGENETICAL FORCING WHICH TAPPED DECENT LOWER LEVEL
MOISTURE. THIS IS/WAS DESPITE ANEMIC UPPER HGT FALLS...20-40M AT
H5. SHORT TERM QPF FROM 4KM WRF/RAP AND HRRR CONTINUE TO LIFT
PRECIP ENE WITH IT EXITING SWRN ZONES NOT TOO LONG AFTER THE
00Z-03Z TIME PERIOD WITH A DEFORMATION BAND OF DWINDLING PRECIP
PROBABLY LINGERING OVER NERN NEBR ALL NIGHT AND POSSIBLY SOME
TRACE FLURRIES YET IN THE MORNING. BASED ON CURRENT STLT/RADAR
TRENDS THIS LOOKS REASONABLE. WILL LEAVE WINTER WEATHER HEADLINE
ALONE FOR THIS EVENING ALTHOUGH ACCUMULATIONS THUS FAR ON SERN
EDGE OF ADVISORY HAVE BEEN MOSTLY LIMITED TO GRASSY SURFACES AND
GENERALLY LESS THAN FORECAST DUE TO WARM GROUND AND SFC TEMPS AT
OR A LITTLE ABOVE FREEZING. WITH APPROACHING NIGHTFALL...SNOW
ACCUMULATIONS SHOULD BE A LITTLE MORE EASILY TO COME BY BUT MOST
ADDITIONAL SHOULD BE AN INCH OR TWO...OR LESS...AFT 00Z. THE
RAIN/SNOW MIX MAY MAKE IT TO OMAHA/LINCOLN BUT IT APPEARS COLDER
AIR SUPPORTING THE CHANGEOVER WILL BE ARRIVING ABOUT THE SAME TIME
THE PRECIP ENDS AT THOSE CITIES.
OTHERWISE...FORECAST IN THE SHORTER TERM IS MAINLY TEMPERATURE
DRIVEN AND LITTLE CHANGES WERE MADE TO FORECAST HIGHS WED THROUGH
FRIDAY. DID BUMP THEM UP A FEW DEGREES SOUTH ON WED WHERE GROUND
WILL BE ABSENT ANY SNOW AS WIND DIRECTION...NW SHIFTING TO WSW
WILL BE FAVORABLE FOR MIXING. BUT IF CLOUDS FAIL TO CLEAR...WHICH
WAS NOT EXPECTED...HIGHS WOULD BE A BIT COOLER. ANY RESIDUAL SNOW
COVER WILL HAVE A DWINDLING IMPACT ON HIGHS THURSDAY AND
ESPECIALLY BY FRIDAY NORTH...WHICH WAS REFLECTED IN PREV FORECAST
AND LOOKED GOOD BASED ON LATEST FORECAST SOUNDINGS. MAIN CHANGE
BEYOND WEDNESDAY WAS TO LOWER LOWS A CATEGORY OR SO THURSDAY NIGHT
ESPECIALLY E...AS RETURN FLOW WILL PROBABLY SET UP TOO LATE TO
KEEP MANY TEMPS FROM DROPPING TOWARD THE MID/UPPER 20S THAT GUIDANCE
FORECAST.
CHERMOK
LONG TERM...FRIDAY NIGHT THROUGH TUESDAY.
MEDIUM RANGE MODELS LEAVE LITTLE TO BE DESIRED IN THE EXTENDED PDS
WITH GREAT VARIATION SEEN BTWN THE ECM/GFS/CMC. THUS MAKING TEMP
FCST AS WELL AS POTENTIAL PCPN MON NIGHT/TUES EXTREMELY
PROBLEMATIC AT BEST.
AS OF NOW...LATEST ECM PROGS LARGE SCALE FLOW TRANSITIONING FROM
ZONAL TO DEVELOPING TWO SIGNIFICANT SHORTWAVE TROFS...ONE OVER THE
PAC NW AND THE OTHER OVER THE GREAT LAKES THUS FAVORING A COLD
PATTERN ACROSS THE CNTRL CONUS. THE GFS ON THE OTHER BASICALLY
MAINTAINS RELATIVELY ZONAL FLOW. MEANWHILE THE CMC DIGS AN UPPER
TROF THRU THE GREAT BASIN WITH SW FLOW ALOFT PREVAILING. COMPARISON
OF MAX/MIN TEMPS BTWN THE 05/00Z ECMMOS AND 05/12Z MEX CLEARLY
SHOWING THE DISTINCTION. HIGHS PROGGED NEXT TUES AT KOMA...ECM MOS
36/MEX 49. GIVEN THAT THE ECM HAS PROVEN TO OUT PERFORM ON A REGULAR
BASIS...FEEL COMPELLED TO TREND TOWARD THE COOLER SOLUTION.
AS FOR POSSIBLE PCPN MON NIGHT/TUES...WILL AGAIN OPT TO GO WITH THE
DRIER ECM.
DEE
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1038 PM MST TUE NOV 5 2013
.AVIATION...
06Z TAF CYCLE
BACK DOOR COLD FRONT CONTINUES TO SLIDE DOWN THE EASTERN PLAINS
AND SHOULD BE REACHING ROSWELL SHORTLY...WITH SOME BRIEF GUSTS
POSSIBLE. OTHERWISE...QUIET NIGHT IN STORE WITH VFR CONDITIONS
PREVAILING. LOCALLY BREEZY CONDITIONS WITH GUSTS BTW 25-30KTS IN
NW FLOW POSSIBLE AROUND KCQC WEDNESDAY AFTN.
34
&&
.PREV DISCUSSION...247 PM MST TUE NOV 5 2013...
IMPRESSIVE WEATHER SYSTEM THAT HAS IMPACTED THE REGION OVER ROUGHLY
THE PAST 18 HOURS IS BEGINNING TO MOVE OUT OF THE AREA. INSTABILITY
SHOWERS CONTINUE OVER CENTRAL AND WESTERN NM HOWEVER THESE WILL
QUICKLY DIMINISH AROUND SUNSET AS A POTENT DRY SLOT SHIFTS EAST INTO
THE AREA. A BACK DOOR FRONTAL BOUNDARY HAS SHIFTED INTO THE NORTHEAST
AND TEMPS ARE PLUMMETING ON GUSTY NORTH WINDS. LATEST HRRR AND RUC
GUIDANCE WITH SUPPORT FROM SREF INDICATES THE POTENTIAL OR A SMALL
BAND OF SNOW ALONG THE EAST SLOPES OF THE SANGRES BETWEEN RED RIVER
AND RATON PASS...AND FROM NEAR DES MOINES/CAPULIN EAST TO CLAYTON FOR
A FEW HOURS THIS EVENING. HAVE FOCUSED CHANCE POPS IN THIS AREA.
THE MAIN FOCUS WILL SHIFT TO VERY COLD TEMPS TONIGHT AS A STRONG
1035MB HIGH PRESSURE CENTER BUILDS OVER COLORADO AND EXCEPTIONALLY
DRY AIR INVADES THE STATE. 20Z OBS ACROSS THE NW CORNER AND AROUND
SW COLORADO ALREADY HAVE FALLEN INTO THE LOWER TEENS. CLEAR SKIES ON
TAP WILL LEAD TO IMPRESSIVE RADIATIONAL COOLING. HIGH WEDNESDAY WILL
REMAIN NEAR 5 TO 10F WITH LIGHTER WINDS AND MORE SUN MAKING IT FEEL
A LITTLE WARMER THAN TODAY. WEDNESDAY NIGHT WILL SEE EVEN STRONGER
TEMPERATURE INVERSIONS ACROSS THE AREA. WOULD NOT BE SURPRISED TO
SEE THE RANGE OF MIN TEMPS WITHIN THE ABQ METRO ON THE ORDER OF 20+
DEGREES BETWEEN THE VALLEY AND FOOTHILLS.
A FAST MOVING DRY UPPER LEVEL TROUGH WILL SWING ACROSS COLORADO AND
INCREASE WESTERLY WINDS OVER EASTERN NM. DOWNSLOPING WILL LEAD TO
MODIFYING TEMPS WITH READINGS NOW 5 TO 10F ABOVE NORMAL. NEUTRAL TO
VERY WEAK COLD ADVECTION BEHIND THIS WAVE WILL BE QUICKLY REPLACED
BY WARM ADVECTION AS THE FLOWS SHIFTS MORE TO THE SOUTHWEST. THE
WEEKEND AND EARLY NEXT WEEK LOOK VERY NICE AS TEMPS MODIFYING ABOVE
NORMAL FOR THE ENTIRE AREA.
GUYER
.FIRE WEATHER...
A FEW SNOW SHOWERS WILL BE POSSIBLE FROM THE SANGRE DE CRISTO
MOUNTAINS EASTWARD THIS EVENING AS AN UPPER LEVEL TROUGH EXITS THE
AREA TO THE EAST. ONLY LIGHT ADDITIONAL ACCUMULATION IS EXPECTED. IN
ADDITION...A GUSTY BACK DOOR COLD FRONT WILL DROP SOUTHWARD THROUGH
THE EASTERN PLAINS TONIGHT.
WITH A LOW AMPLITUDE RIDGE OF HIGH PRESSURE ALOFT MOVING IN FROM THE
WEST...HIGH TEMPERATURES ALONG AND WEST OF I-25 ARE EXPECTED TO WARM
A FEW TO 11 DEGREES ON WEDNESDAY COMPARED TO TODAYS READINGS.
FARTHER EAST...READINGS SHOULD FALL A FEW TO 11 DEGREES DUE TO THE
BACK DOOR COLD FRONT. WIDESPREAD POOR VENTILATION IS ALSO EXPECTED
WEDNESDAY...EXCEPT FOR THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN
AND THE NORTHEAST PLAINS WHERE BETTER VENTILATION IS EXPECTED DUE TO
A WEAK LEE TROUGH. VENTILATION SHOULD IMPROVE IN MOST LOCATIONS
THURSDAY AS TEMPERATURES RISE A FEW TO 9 DEGREES...EXCEPT FROM
ALBUQUERQUE TO GALLUP...FARMINGTON AND CHAMA WHERE A BROAD AREA OF
POOR VENTILATION SHOULD PERSIST AS THE LOW AMPLITUDE RIDGE OF HIGH
PRESSURE CROSSES ALOFT.
ANOTHER UPPER LEVEL TROUGH WILL PASS NORTH OF NEW MEXICO FRIDAY
CAUSING WESTERLY MOUNTAIN TOP WINDS TO STRENGTHEN TO 20-35 KTS WHILE
A SHARP LEE TROUGH DEVELOPS AT THE SURFACE. SURFACE WINDS SHOULD
BECOME GUSTY WITH DECENT VENTILATION AREAWIDE. SURFACE WINDS SHOULD
BE BREEZIEST IN THE SANGRE DE CRISTO MOUNTAINS AND ACROSS PARTS OF
THE EAST CENTRAL AND NORTHEAST PLAINS. IN THE WAKE OF THIS UPPER
LEVEL TROUGH...TEMPERATURES SHOULD FALL A FEW TO 9 DEGREES ACROSS THE
EAST ON SATURDAY AS A WEAK BACK DOOR COLD FRONT SAGS SOUTHWARD
THROUGH THE PLAINS. POOR VENTILATION MAY ALSO BECOME WIDESPREAD
AGAIN ON SATURDAY AS WINDS WEAKEN ALOFT AND AT THE SURFACE.
POOR VENTILATION IS EXPECTED TO LINGER ACROSS NORTHERN...CENTRAL AND
WESTERN AREAS ON SUNDAY AS THE FLOW ALOFT BEGINS TO TURN A BIT OUT
OF THE SOUTHWEST IN RESPONSE TO A DEEPENING LOW PRESSURE SYSTEM OFF
THE PACIFIC NW COAST. TEMPERATURES SHOULD ALSO REBOUND ABOVE NORMAL
AGAIN AFTER SATURDAYS BRIEF COOL DOWN ON THE PLAINS.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
317 PM EST WED NOV 6 2013
.SYNOPSIS...
A TROUGH PUSHING WEST TOWARD THE COAST WILL PRODUCE SOME RAIN OVER
THE COASTAL CAROLINAS TONIGHT. A COLD FRONT WILL MOVE THROUGH ON
THURSDAY CLEARING OUT ALL OF THE CLOUDS AND SHOWERS AND BRINGING
COOLER WEATHER FOR FRIDAY. HIGH PRESSURE WILL BUILD IN THROUGH THE
WEEKEND MAINTAINING DRIER AND MORE SEASONABLE WEATHER INTO EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM WEDNESDAY...A WONDERFUL EARLY NOVEMBER DAY IN THE
CAROLINAS WILL CHANGE TONIGHT AS A HORIZONTALLY-CONVERGENT AND
VERTICALLY-ASCENDING FLOW DEVELOPS NEAR A COASTAL TROUGH MOVING
TOWARD THE CAROLINA COAST. THIS TROUGH...EASILY DISCERNIBLE ON
VISIBLE SATELLITE IMAGERY EXTENDING ALONG THE WESTERN EDGE OF THE
GULF STREAM...IS EXPECTED TO APPROACH THE COAST BY MIDNIGHT AND MAY
ACTUALLY PUSH ONSHORE IN SOUTHEASTERN NORTH CAROLINA.
MILD ATLANTIC AIR STREAMING UP AND OVER THE WARM FRONT-LIKE BOUNDARY
WILL BE LIFTED ALONG THE 300-305K ISENTROPIC SURFACES...LIKELY
YIELDING AROUND ONE-THIRD INCH OF SHOWERY RAIN FROM MYRTLE BEACH...
SOUTHPORT AND WILMINGTON THROUGH WHITEVILLE AND ELIZABETHTOWN. ONE
OR TWO TENTHS OF AN INCH OF RAIN IS EXPECTED FROM GEORGETOWN AND
MARION THROUGH DILLON AND LUMBERTON. FARTHER INLAND FOR AREAS WEST
OF FLORENCE...THE ATLANTIC MOISTURE FEED MAY HAVE TROUBLE REACHING
YOU AS VEERING WIND PROFILES BELOW 700 MB COULD CREATE A WESTERLY
COMPONENT WITHIN THE CLOUD-BEARING LAYER BEFORE THE ATLANTIC
MOISTURE IS ABLE TO PUSH THAT FAR INLAND. I HAVE LOWER RAIN CHANCES
HERE ONLY IN THE 20-30 PERCENT RANGE.
IN TERMS OF MODEL PREFERENCE...THE 12Z GFS LOOKS PRETTY GOOD AS DO
THE LATEST SEVERAL RUC AND HRRR RUNS. THE 12Z NAM REALLY EMPHASES
LOW PRESSURE ALONG THE SOUTHERN END OF THE COASTAL TROUGH JUST OFF
THE FLORIDA COAST. WHILE SATELLITE LOOPS SUGGEST THERE A WEAK LOW
ABOUT 200 MILES EAST OF JAX...THE NAM APPEARS TO BE TOO BULLISH
CLOSING THIS FEATURE OFF ALONG THE GEORGIA COAST OVERNIGHT. THE NAM
IS ALSO THE FARTHEST WEST WITH ITS QPF MAX COMPARED TO OTHER
GUIDANCE.
CLOUDS SHOULD HELP HOLD TEMPERATURES WELL ABOVE NORMAL TONIGHT WITH
FORECAST LOWS RANGING FROM THE LOWER 60S AT THE COAST TO THE UPPER
50S INLAND. KEEP IN MIND OUR CLIMATOLOGICAL NORMALS FOR LOWS HAVE
FALLEN TO THE MID TO UPPER 40S THIS LATE IN THE YEAR.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...COASTAL TROUGH RIGHT ALONG THE CAPE
FEAR COAST THURS MORNING WILL OPEN UP AND DISSIPATE AS COLD FRONT
PUSHES EAST ACROSS THE FORECAST AREA ON THURS. THE SOUTHERLY
RETURN FLOW WILL PUMP A GOOD DEAL OF ATLANTIC MOISTURE NORTHWARD
THROUGH EARLY THURS. THE BEST CONVERGENCE AND MOISTURE WILL RUN
NORTH FROM THE BRUNSWICK AND CAPE FEAR COAST UP THROUGH NORTH
CAROLINA. THE NAM SHOWS A DEEPER TROUGH AND PUSHES IT INLAND
FURTHER SO MAY KEEP POPS SLIGHTLY FARTHER INLAND FOR NOW. THIS AXIS
OF GREATEST PCP THURS MORNING WILL SHIFT EAST AND OFF SHORE BY
THURS AFTN AS WINDS VEER AROUND TO THE WEST TO NORTHWEST AS COLD
FRONT PROGRESSES THROUGH THE CAROLINAS.
THE ACTUAL COLD FRONT LOSES SOME OF ITS MOISTURE AS IT MOVES OVER THE
APPALACHIANS THURS MORNING BUT IT SHOULD HELP TO ENHANCE THE
CONVERGENCE AHEAD AND ALONG THE FRONT THURS AFTN. AS MENTIONED...LOOKS
LIKE GREATEST PCP WILL COME EARLIER IN THE DAY WITH TROUGH ALONG
THE COAST...BUT EXPECT SOME CONVECTIVE DEVELOPMENT JUST ALONG AND AHEAD OF
FRONT THROUGH LATE THURS AFTN.
DEEP COOL AND DRY NORTHWEST TO NORTHERLY FLOW WILL DEVELOP BEHIND
THE FRONT THROUGH THURS EVENING INTO FRIDAY. 850 TEMPS BEGIN TO
PLUMMET THURS AFTN DROPPING FROM AROUND 13C DOWN TO 3C TO 4C BY
FRI MORNING. PCP WATER VALUES UP TO 1.5 INCHES AHEAD OF THE FRONT
WILL DROP OUT TO A QUARTER OF INCH ON FRIDAY. TEMPS WILL DROP INTO
THE 40S FRI NIGHT IN CAA BEHIND FRONT. THE TIGHTENED GRADIENT WILL
PRODUCE COOLER BLUSTERY CONDITIONS FOR THE CAROLINAS ON FRIDAY
BUT THE NORTHERLY WINDS WILL DIMINISH AS HIGH PRESSURE BUILDS EAST
THROUGH FRI EVENING. HIGH TEMPS ON FRI WILL MAKE IT TO AROUND 60
IN CONTINUED CAA UNDER BRIGHT FALL SUNSHINE. BETTER RADIATIONAL
COOLING CONDITIONS WILL EXIST THROUGH FRI EVENING AS WINDS DROP
OFF AND CLEAR SKIES EXIST. EXPECT TEMPS TO DROP INTO THE 30S MOST
PLACES FRI NIGHT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...DRY AND SEASONABLE WEATHER FOR THE EXTENDED
THANKS TO A COMBINATION OF FLAT 5H FLOW AND SURFACE HIGH PRESSURE
PERSISTING ACROSS THE EAST.
NEARLY ZONAL FLOW ALOFT WILL KEEP THE COLD AIR WELL NORTH OF THE
AREA...BUT ALLOW REINFORCING AREAS OF HIGH PRESSURE TO ADVECT WEST
TO EAST FROM THE PLAINS TO THE CAROLINAS THROUGH THE PERIOD. OTHER
THAN A WEAK AND DRY COLD FRONT SUNDAY NIGHT/MONDAY MORNING...VERY
LITTLE IN THE WAY OF SIGNIFICANT FEATURES TO DISCUSS DURING NEXT
WEEK. THIS WILL KEEP SKY CONDITIONS PRIMARILY CLEAR (ALTHOUGH SOME
MID-LEVEL CLOUDINESS IS EXPECTED WITH THE FRONT SUNDAY NIGHT)...AND
TEMPS NEAR SEASONABLE LEVELS. THE EXCEPTION WILL BE SATURDAY WHEN
HIGHS WILL RISE ONLY INTO THE LOW/MID 60S...BUT SUN-WED WILL FEATURE
HIGHS APPROACHING 70 AND LOWS IN THE 40S. A STRONGER COLD FRONT WILL
APPROACH AT THE END OF THE PERIOD /WED NIGHT/ AS THE LEADING EDGE OF
MUCH COOLER AIR...BUT ATTM LOOKS LIKE IT MAY ALSO BE DRY. THUS...NO
PRECIP FOR THE EXTENDED.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...LOOK FOR INCREASING ALTOCUMULUS CEILINGS THROUGH THE
LATE AFTERNOON INTO THE EVENING HOURS. THE HRRR MODEL IS ADVERTISING
SOME LIGHT SHOWERS ALONG THE COAST LATE THIS AFTERNOON...ASSOCIATED
WITH A WEAK COASTAL TROUGH. BY LATE THIS EVENING...MODELS IN FAIRLY
GOOD AGREEMENT INTRODUCING IFR CEILINGS/VISIBILITIES CAUSED BY
INCREASING COVERAGE OF MAINLY LIGHT RAIN/SHOWER ACTIVITY. THE NAM
MODEL MAY BE A BIT EARLY...BUT MODERATE CONFIDENCE WE WILL SEE IFR
CONDITIONS AT ALL TERMINALS AFTER 06Z. MAINLY LIGHT WINDS
OVERNIGHT...EXCEPT ALONG THE COAST WHERE ONSHORE WINDS COULD REMAIN
IN THE 8-10 KNOT RANGE. THURSDAY...POSSIBILITY OF SHOWERS LATE AS A
SURFACE LOW RIDES NORTHWARD AHEAD OF A COLD FRONT. LOW CONFIDENCE ON
WIND DIRECTION THURSDAY...DUE TO THE LOW.
EXTENDED OUTLOOK...CHANCE OF SHOWERS THURSDAY AFTERNOON WITH A COLD
FRONT. VFR FRIDAY THROUGH SUNDAY. MORNING FOG POSSIBLE MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE OVER THE NORTHWESTERN
ATLANTIC (JUST SOUTH OF NEWFOUNDLAND) HAS MAINTAINED A HEALTHY
NORTHEASTERLY WIND ACROSS THE WESTERN ATLANTIC FOR SEVERAL DAYS. THE
HIGH IS BREAKING DOWN WHICH HAS CUT THE PRESSURE GRADIENT ACROSS THE
ATLANTIC ALMOST IN HALF OVER THE PAST 12 HOURS. A COASTAL TROUGH
CURRENTLY LINED UP NEAR THE WESTERN EDGE OF THE GULF STREAM FROM THE
OUTER BANKS TO JACKSONVILLE FLORIDA SHOULD APPROACH THE COAST
OVERNIGHT BEFORE STALLING AND SLOWLY DISSIPATING IN THE INCREASING
SOUTHERLY FLOW AHEAD OF A COLD FRONT. A ZONE OF ENHANCED
SOUTHEASTERLY FLOW JUST BEHIND OF (EAST OF) TROUGH SHOULD HELP
MAINTAIN 4-6 FOOT SEAS ACROSS THE CAPE FEAR AREA WATERS TONIGHT...
THEREFORE THE SMALL CRAFT ADVISORY HAS BEEN EXTENDED INTO THURSDAY
MORNING.
NORTHEAST WINDS WILL CONTINUE THROUGH THE EVENING...BUT SHOULD VEER
MORE SOUTHEASTERLY AROUND OR AFTER MIDNIGHT AS THE COASTAL TROUGH
MOVES CLOSER TO SHORE. WIND SPEEDS SHOULD AVERAGE 10-15 KNOTS EXCEPT
5 KNOTS STRONGER FOR AREAS THAT ACTUALLY GET INTO THE SOUTHEAST
WINDS BEHIND THE TROUGH.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...WITH TROUGH ALONG THE COAST OR JUST
INLAND...WINDS WILL BE SOUTHERLY UP TO 15 KTS TO START THE DAY ON
THURS. THE SOUTHERLY PUSH WILL KEEP SEAS AROUND 3 TO 6 FT
INITIALLY BUT DIMINISHING QUICKLY AS WINDS VEER AROUND THROUGH
THE DAY ON THURS AS COLD FRONT APPROACHES FROM THE WEST.
THIS COLD FRONT WILL PROGRESS THROUGH THE CAROLINAS THURS
AFTERNOON WITH WINDS VEERING AROUND TO WEST AND EVENTUALLY
NORTHWEST THROUGH THURS EVENING. WINDS WILL BECOME NORTHWEST TO
NORTH BEHIND FRONT AS IT MOVES EAST OF THE WATERS THURS NIGHT. PLENTY
OF COOL AND DRY AIR WILL PRODUCE A WELL MIXED MARINE ENVIRONMENT
AND EXPECT STRENGTHENING NORTHERLY WINDS UP TO 25 KTS WITH HIGHER
GUSTS THROUGH EARLY FRI MORNING IN DEEPER CAA. THIS WILL PRODUCE AN
INCREASE IN SEAS UP TO 4 TO 7 FT IN OUTER WATERS AFTER MIDNIGHT
THURS NIGHT INTO EARLY FRIDAY. WINDS ALONE WILL BE ENOUGH TO
WARRANT SCA LATE THU NIGHT INTO FRI MORNING...BUT SEAS WILL SHOOT
UP ALSO.
WINDS WILL DECREASE THROUGH LATE FRI INTO FRI NIGHT AND VEER TO
NORTHEAST AS CENTER OF HIGH PRESSURE MOVES CLOSER TO THE
CAROLINAS. THE DECREASE IN SPEED AND VEERING OF WINDS LATER FRI
AND FRI NIGHT WILL KNOCK SEAS BACK DOWN TO 2 TO 4 FT.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...A SERIES OF HIGH PRESSURES WILL MOVE
ACROSS THE WATERS DURING THE EXTENDED...AND WINDS BEGIN THE PERIOD
FROM THE NE AROUND 10 KTS BEFORE BACKING SLOWLY THROUGH SATURDAY
AS A SECONDARY HIGH PRESSURE BUILDS DOWN FROM THE NW. AS THIS HIGH
PRESSURE MOVES INTO THE AREA SUNDAY...IT DRIVES A DRY COLD FRONT
ACROSS THE WATERS...WITH WINDS INCREASING TO AROUND 15 KTS AND
TURNING BACK TO THE NE SUNDAY NIGHT. THESE NE WINDS PERSIST
MONDAY...WHILE ONLY SLOWLY EASING. SEAS WILL BE WIND-DRIVEN DURING
THE PERIOD...BUT THANKS TO THE LOW SPEEDS...AMPLITUDES WILL BE 1-3
FT EACH DAY...WITH A BRIEF INCREASE TO 2-4 FT LATE SUNDAY AND INTO
MONDAY WITH THE FROPA.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EST THURSDAY FOR AMZ250-252.
&&
$$
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...TRA/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1230 PM EST WED NOV 6 2013
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN NORTHEAST WINDS ACROSS THE AREA THIS
MORNING. TEMPERATURES WILL START TO WARM TODAY AS HIGH PRESSURE
SHIFTS OFF THE COAST AND SOUTHERLY WINDS DEVELOP. TEMPERATURES
WILL REMAIN WARM INTO THURSDAY AHEAD OF AN APPROACHING COLD FRONT.
THE FRONT WILL MOVE OFF THE COAST LATE THURSDAY AND WILL BE
FOLLOWED BY COOLER AND DRIER WEATHER INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM WEDNESDAY...TWEAKED INLAND HIGH TEMPERATURE FORECASTS
UP A DEGREE OR TWO INTO THE MID 70S...OTHERWISE NO SIGNIFICANT
CHANGES NEEDED. PREVIOUS DISCUSSION FROM 930 AM FOLLOWS...
STRONG UPPER LEVEL HIGH PRESSURE SITS JUST OFF THE SOUTHEAST U.S.
COAST...WHILE AT THE SURFACE THE HIGH IS CENTERED JUST SOUTH OF THE
NEWFOUNDLAND CANADA COAST. A LONG EASTERLY FETCH AT THE SURFACE
CROSSES OVER A THOUSAND MILES OF WESTERN ATLANTIC OCEAN WATER BEFORE
COMING ONSHORE INTO THE CAROLINAS. PLENTY OF MOISTURE IN THE LOWEST
7500 FEET OF THE ATMOSPHERE IS PRODUCING AREAS OF EXTENSIVE
ALTOCUMULUS...SOME OF WHICH ARE PRODUCING SHOWERS OFF THE COAST.
ISENTROPIC LIFT ALONG THE 300K THETA SURFACE IS EXPECTED TO INCREASE
BY LATE AFTERNOON IN THE CAPE FEAR REGION WITH SKIES BECOMING CLOUDY
AND AN INCREASING SHOWER POTENTIAL NOTED. FARTHER INLAND THERE
SHOULD BE ABOUT A 50/50 MIX OF CLOUDS AND SUN TODAY. WITH THE
OVERALL AIRMASS QUITE MILD FOR THIS DATE HIGHS SHOULD REACH THE
LOWER 70S DESPITE THE CLOUDS...A LITTLE ABOVE NORMAL.
FOR TONIGHT I HAVE MADE SOME UPWARD CHANGES TO POPS...PARTICULARLY
IN THE CAPE FEAR REGION WHERE THE LATEST HRRR AND 06Z GFS SHOW A
CONCENTRATED "STREAMER" OF MOISTURE AND ISENTROPIC LIFT MOVING
NORTHWARD FROM THE GULF STREAM SOUTH OF CAPE FEAR. THIS IS ACTUALLY
A FAIRLY TYPICAL SCENARIO IN WEAKLY FORCED VEERING WIND
SITUATIONS...AND ASSUMING 12Z MODELS CONTINUE TO SHOW THIS POTENTIAL
I PLAN TO INCREASE POPS IN THE WILMINGTON AREA OVER 50 PERCENT FOR
TONIGHT. FARTHER INLAND CURRENTLY POPS FOR TONIGHT ARE IN THE 20-30
PERCENT REGION AS IT APPEARS THE LIMITED DEPTH OF MOISTURE MAY NOT
MAKE IT TOO FAR INLAND BEFORE THE 850-700 MB FLOW ATTAINS A BIT OF
WESTERLY COMPONENT...SHUTTING DOWN ANY ATLANTIC INFLOW. 12Z MODELS
SHOULD HELP REFINE THIS POTENTIAL AS WELL.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM WEDNESDAY...COLD FRONT SLATED TO MOVE ACROSS THE AREA
DURING THE FIRST HALF OF THE PERIOD WILL BRING BELOW CLIMO TEMPS FOR
THE END OF THE WEEK. FRONT ITSELF MAY PASS DRY WITH THE BEST PRECIP
CHANCES BEING ASSOCIATED WITH A PRE-FRONTAL TROUGH PUSHING OFF THE
COAST AS THE PERIOD BEGINS. BY THE TIME THE FRONT REACHES THE
CAROLINAS THE 5H TROUGH WILL HAVE WEAKENED CONSIDERABLY AND THE
ORIENTATION OF THE 5H RIDGE SOUTH OF THE AREA DOES NOT ALLOW FOR A
SIGNIFICANT GULF MOISTURE TAP. ADDITIONALLY THE DYNAMICS ARE
DISPLACED WELL NORTH OF THE AREA AND BAGGINESS IN THE GRADIENT OFF
THE COAST POINTS TO DEVELOPMENT OF WEAK LOW ON THE TAIL END OF THE
TROUGH...FURTHER LIMITING THE FRONTS ABILITY TO PRODUCE PRECIP.
INHERITED SLIGHT CHANCE POP INLAND FOR FIRST HALF OF THU IS
REASONABLE BUT WILL BUMP UP POP TO CHC ALONG THE COAST FOR FIRST
PART OF THU.
A MUCH DRIER AND COOLER AIR MASS BUILDS IN BEHIND THE FRONT THU
NIGHT INTO FRI. PRECIPITABLE WATER VALUES DROP UNDER 0.25 INCH BY
FRI MORNING AND REMAIN BELOW 0.30 INCH THROUGH THE END OF THE
PERIOD. ALTHOUGH THE DEEP DRY AIR WILL LEAD TO SUNNY SKIES COLD
ADVECTION...WHICH WILL CONTINUE INTO FRI NIGHT...WILL KEEP
TEMPERATURES BELOW TO WELL BELOW CLIMO. SOME AREAS WILL SEE HIGHS
AROUND 60 FRI WITH LOWS IN THE MID 30S TO AROUND 40 FRI NIGHT.
COMBINATION OF TIGHT GRADIENT AND MIXING OF STRONGER WINDS ALOFT
COULD MAKE FRI A BREEZY DAY. BOUNDARY LAYER WINDS START TO WEAKEN
FRI NIGHT BUT IT MAY BE A CASE OF TOO LITTLE TOO LATE AS FAR AS
STRONG RADIATIONAL COOLING IS CONCERNED.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 230 AM WEDNESDAY...FLAT MID LEVEL PATTERN WILL LEAD TO A
RELATIVELY QUIET PERIOD WITH COLDEST AIR REMAINING TRAPPED WELL TO
THE NORTH. HIGH PRESSURE IN CONTROL SAT WILL BE REINFORCED BY SECOND
AREA OF HIGH PRESSURE FOLLOWING COLD FRONT EARLY SUN. FRONT PASSES
DRY WITH NEXT TO NO COLD AIR...THE ONLY THING SIGNIFYING ITS PASSAGE
WILL BE WINDS SHIFTING FROM SOUTHERLY TO NORTHWEST. DURING THE
MIDDLE OF NEXT WEEK CLOUD COVER MAY START TO INCREASE AS MOISTURE
ASSOCIATED WITH LOW PRESSURE DEVELOPING OVER THE MIDWEST SPREADS
EAST. THIS SYSTEM IS UNLIKELY TO HAVE ANY SIGNIFICANT IMPACT ON THE
CAROLINAS BEFORE THE END OF THE PERIOD. ZONAL FLOW ALOFT WILL HELP
KEEP TEMPERATURES NEAR CLIMO THROUGH THE PERIOD...WITH THE EXCEPTION
OF SAT WHEN TEMPERATURES MAY RUN A LITTLE BELOW CLIMO.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...LOOK FOR INCREASING ALTOCUMULUS CEILINGS THROUGH THE
LATE AFTERNOON INTO THE EVENING HOURS. THE HRRR MODEL IS ADVERTISING
SOME LIGHT SHOWERS ALONG THE COAST LATE THIS AFTERNOON...ASSOCIATED
WITH A WEAK COASTAL TROUGH. BY LATE THIS EVENING...MODELS IN FAIRLY
GOOD AGREEMENT INTRODUCING IFR CEILINGS/VISIBILITIES CAUSED BY
INCREASING COVERAGE OF MAINLY LIGHT RAIN/SHOWER ACTIVITY. THE NAM
MODEL MAY BE A BIT EARLY...BUT MODERATE CONFIDENCE WE WILL SEE IFR
CONDITIONS AT ALL TERMINALS AFTER 06Z. MAINLY LIGHT WINDS
OVERNIGHT...EXCEPT ALONG THE COAST WHERE ONSHORE WINDS COULD REMAIN
IN THE 8-10 KNOT RANGE. THURSDAY...POSSIBILITY OF SHOWERS LATE AS A
SURFACE LOW RIDES NORTHWARD AHEAD OF A COLD FRONT. LOW CONFIDENCE ON
WIND DIRECTION THURSDAY...DUE TO THE LOW.
EXTENDED OUTLOOK...CHANCE OF SHOWERS THURSDAY AFTERNOON WITH A COLD
FRONT. VFR FRIDAY THROUGH SUNDAY. MORNING FOG POSSIBLE MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM WEDNESDAY...SMALL CRAFT ADVISORY ALLOWED TO EXPIRE ON
SCHEDULE FOR THE SC WATERS AS THE WINDS/SEAS BEGIN TO SUBSIDE. NO
SIGNIFICANT CHANGES. PREVIOUS DISCUSSION FROM 930 AM FOLLOWS...
SMALL CRAFT ADVISORIES REMAIN POSTED FOR 6-7 FOOT SEAS MAINLY AT THE
OUTER MARGIN OF THE SOUTH CAROLINA COASTAL WATERS AND BEYOND 5-10
MILES FROM SHORE ACROSS THE NC WATERS. THE CULPRIT IS A 1500+ MILE
EASTERLY FETCH ACROSS MOST OF THE WESTERN ATLANTIC PRODUCED BY 1035
MB HIGH PRESSURE SOUTH OF NEWFOUNDLAND CANADA. AS THIS HIGH WEAKENS
AND THE SYNOPTIC FLOW VEERS MORE SOUTHERLY WITH THE APPROACHING COLD
FRONT THE FETCH SHOULD DIMINISH CONSIDERABLY DURING THE AFTERNOON.
CHANGES WITH THIS MORNING UPDATE WERE GENERALLY MINOR...LIMITED TO
COVERAGE OF SHOWERS BASED ON CURRENT RADAR IMAGERY AND RUC/HRRR
PROGS THROUGH THE AFTERNOON.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM WEDNESDAY...SOUTHERLY FLOW AT THE START OF THE PERIOD
WILL QUICKLY BECOME WESTERLY AS PRE-FRONTAL TROUGH CROSSES THE
WATERS. STRENGTH OF OFFSHORE FLOW WILL BE LIMITED UNTIL AFTER
PASSAGE OF COLD FRONT LATER THU. PINCHED PRESSURE GRADIENT AND COLD
ADVECTION THU NIGHT AND FRI WILL LEAD TO OFFSHORE FLOW IN THE 20 TO
25 KT RANGE WITH GUSTS EXCEEDING 30 KT. GIVEN OFFSHORE TRAJECTORY
AND LIMITED FETCH CONFIDENCE IN SEAS WITHIN 20 NM REACHING 6 FT FOR
ALL ZONES IS LOW...THOUGH WIND SPEEDS ARE LIKELY TO BE ENOUGH TO
WARRANT SCA THU NIGHT AND FRI MORNING. WIND SPEEDS DECREASE LATE FRI
AND FRI NIGHT AND VEER TO NORTHEAST AS CENTER OF HIGH PRESSURE MOVES
INTO THE CENTRAL APPALACHIANS AND THE GRADIENT WEAKENS. SEAS 2 TO 4
FT EARLY THU WILL BUILD TO 4 TO 7 FT THU NIGHT AND FRI. THE DECREASE
IN SPEED AND VEERING OF WINDS LATER FRI AND FRI NIGHT WILL KNOCK
SEAS BACK TO 3 TO 5 FT FOR THE LATER HALF OF THE PERIOD.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 230 AM WEDNESDAY...HIGH PRESSURE WILL DOMINATE THE
PERIOD...BROKEN BY PASSAGE OF RELATIVELY WEAK COLD FRONT SAT NIGHT
INTO SUN. WINDS AND SEAS WILL BE DECREASING SAT AS HIGH PRESSURE
SETTLES OVER THE WATERS AND THEN DRIFTS TO THE SOUTH SAT NIGHT.
PASSAGE OF COLD FRONT LATE SAT NIGHT IS LIKELY TO BE MORE OF A WIND
SHIFT THAN A TRUE FRONTAL PASSAGE. THERE WILL BE A SLIGHT INCREASE
IN WINDS BEHIND THE FRONT AS GRADIENT BECOMES A LITTLE MORE DEFINED
AND SLIGHTLY COOLER AIR BUILDS IN. SPEEDS WILL INCREASE FROM AROUND
10 KT ON SAT TO 10 TO 15 KT FOR SUN. SEAS WILL VARY FROM AROUND 2 FT
TO 2 TO 3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ250-
252.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...43/TRA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
945 AM EST WED NOV 6 2013
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN NORTHEAST WINDS ACROSS THE AREA THIS
MORNING. TEMPERATURES WILL START TO WARM TODAY AS HIGH PRESSURE
SHIFTS OFF THE COAST AND SOUTHERLY WINDS DEVELOP. TEMPERATURES
WILL REMAIN WARM INTO THURSDAY AHEAD OF AN APPROACHING COLD FRONT.
THE FRONT WILL MOVE OFF THE COAST LATE THURSDAY AND WILL BE
FOLLOWED BY COOLER AND DRIER WEATHER INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM WEDNESDAY...STRONG UPPER LEVEL HIGH PRESSURE SITS JUST
OFF THE SOUTHEAST U.S. COAST...WHILE AT THE SURFACE THE HIGH IS
CENTERED JUST SOUTH OF THE NEWFOUNDLAND CANADA COAST. A LONG
EASTERLY FETCH AT THE SURFACE CROSSES OVER A THOUSAND MILES OF
WESTERN ATLANTIC OCEAN WATER BEFORE COMING ONSHORE INTO THE
CAROLINAS. PLENTY OF MOISTURE IN THE LOWEST 7500 FEET OF THE
ATMOSPHERE IS PRODUCING AREAS OF EXTENSIVE ALTOCUMULUS...SOME OF
WHICH ARE PRODUCING SHOWERS OFF THE COAST. ISENTROPIC LIFT ALONG THE
300K THETA SURFACE IS EXPECTED TO INCREASE BY LATE AFTERNOON IN THE
CAPE FEAR REGION WITH SKIES BECOMING CLOUDY AND AN INCREASING SHOWER
POTENTIAL NOTED. FARTHER INLAND THERE SHOULD BE ABOUT A 50/50 MIX OF
CLOUDS AND SUN TODAY. WITH THE OVERALL AIRMASS QUITE MILD FOR THIS
DATE HIGHS SHOULD REACH THE LOWER 70S DESPITE THE CLOUDS...A LITTLE
ABOVE NORMAL.
FOR TONIGHT I HAVE MADE SOME UPWARD CHANGES TO POPS...PARTICULARLY
IN THE CAPE FEAR REGION WHERE THE LATEST HRRR AND 06Z GFS SHOW A
CONCENTRATED "STREAMER" OF MOISTURE AND ISENTROPIC LIFT MOVING
NORTHWARD FROM THE GULF STREAM SOUTH OF CAPE FEAR. THIS IS ACTUALLY
A FAIRLY TYPICAL SCENARIO IN WEAKLY FORCED VEERING WIND
SITUATIONS...AND ASSUMING 12Z MODELS CONTINUE TO SHOW THIS POTENTIAL
I PLAN TO INCREASE POPS IN THE WILMINGTON AREA OVER 50 PERCENT FOR
TONIGHT. FARTHER INLAND CURRENTLY POPS FOR TONIGHT ARE IN THE 20-30
PERCENT REGION AS IT APPEARS THE LIMITED DEPTH OF MOISTURE MAY NOT
MAKE IT TOO FAR INLAND BEFORE THE 850-700 MB FLOW ATTAINS A BIT OF
WESTERLY COMPONENT...SHUTTING DOWN ANY ATLANTIC INFLOW. 12Z MODELS
SHOULD HELP REFINE THIS POTENTIAL AS WELL.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM WEDNESDAY...COLD FRONT SLATED TO MOVE ACROSS THE AREA
DURING THE FIRST HALF OF THE PERIOD WILL BRING BELOW CLIMO TEMPS FOR
THE END OF THE WEEK. FRONT ITSELF MAY PASS DRY WITH THE BEST PRECIP
CHANCES BEING ASSOCIATED WITH A PRE-FRONTAL TROUGH PUSHING OFF THE
COAST AS THE PERIOD BEGINS. BY THE TIME THE FRONT REACHES THE
CAROLINAS THE 5H TROUGH WILL HAVE WEAKENED CONSIDERABLY AND THE
ORIENTATION OF THE 5H RIDGE SOUTH OF THE AREA DOES NOT ALLOW FOR A
SIGNIFICANT GULF MOISTURE TAP. ADDITIONALLY THE DYNAMICS ARE
DISPLACED WELL NORTH OF THE AREA AND BAGGINESS IN THE GRADIENT OFF
THE COAST POINTS TO DEVELOPMENT OF WEAK LOW ON THE TAIL END OF THE
TROUGH...FURTHER LIMITING THE FRONTS ABILITY TO PRODUCE PRECIP.
INHERITED SLIGHT CHANCE POP INLAND FOR FIRST HALF OF THU IS
REASONABLE BUT WILL BUMP UP POP TO CHC ALONG THE COAST FOR FIRST
PART OF THU.
A MUCH DRIER AND COOLER AIR MASS BUILDS IN BEHIND THE FRONT THU
NIGHT INTO FRI. PRECIPITABLE WATER VALUES DROP UNDER 0.25 INCH BY
FRI MORNING AND REMAIN BELOW 0.30 INCH THROUGH THE END OF THE
PERIOD. ALTHOUGH THE DEEP DRY AIR WILL LEAD TO SUNNY SKIES COLD
ADVECTION...WHICH WILL CONTINUE INTO FRI NIGHT...WILL KEEP
TEMPERATURES BELOW TO WELL BELOW CLIMO. SOME AREAS WILL SEE HIGHS
AROUND 60 FRI WITH LOWS IN THE MID 30S TO AROUND 40 FRI NIGHT.
COMBINATION OF TIGHT GRADIENT AND MIXING OF STRONGER WINDS ALOFT
COULD MAKE FRI A BREEZY DAY. BOUNDARY LAYER WINDS START TO WEAKEN
FRI NIGHT BUT IT MAY BE A CASE OF TOO LITTLE TOO LATE AS FAR AS
STRONG RADIATIONAL COOLING IS CONCERNED.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 230 AM WEDNESDAY...FLAT MID LEVEL PATTERN WILL LEAD TO A
RELATIVELY QUIET PERIOD WITH COLDEST AIR REMAINING TRAPPED WELL TO
THE NORTH. HIGH PRESSURE IN CONTROL SAT WILL BE REINFORCED BY SECOND
AREA OF HIGH PRESSURE FOLLOWING COLD FRONT EARLY SUN. FRONT PASSES
DRY WITH NEXT TO NO COLD AIR...THE ONLY THING SIGNIFYING ITS PASSAGE
WILL BE WINDS SHIFTING FROM SOUTHERLY TO NORTHWEST. DURING THE
MIDDLE OF NEXT WEEK CLOUD COVER MAY START TO INCREASE AS MOISTURE
ASSOCIATED WITH LOW PRESSURE DEVELOPING OVER THE MIDWEST SPREADS
EAST. THIS SYSTEM IS UNLIKELY TO HAVE ANY SIGNIFICANT IMPACT ON THE
CAROLINAS BEFORE THE END OF THE PERIOD. ZONAL FLOW ALOFT WILL HELP
KEEP TEMPERATURES NEAR CLIMO THROUGH THE PERIOD...WITH THE EXCEPTION
OF SAT WHEN TEMPERATURES MAY RUN A LITTLE BELOW CLIMO.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...SURFACE RIDGE HOLDING IN...HOWEVER SOME MID CLOUDS ARE
MOVING ONSHORE THIS MORNING. THERE MAY EVEN BE A SPRINKLE HERE AND
THERE...MAINLY NEAR THE COAST DUE TO A VERY WEAK COASTAL TROUGH.
WINDS WILL BE MAINLY NORTHEASTERLY THIS MORNING...BECOMING A BIT
MORE EASTERLY THIS AFTERNOON. THE MID CLOUDS WILL CONTINUE TO BE IN
AND OUT THROUGH THIS EVENING. A CONTINUED CHANCE OF A SPRINKLE
OVERNIGHT AS COASTAL TROUGH SHARPENS A BIT.
EXTENDED OUTLOOK...CHANCE OF SHOWERS WITH MVFR CIGS POSSIBLE LATE
WEDNESDAY INTO THURSDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM WEDNESDAY...SMALL CRAFT ADVISORIES REMAIN POSTED FOR
6-7 FOOT SEAS MAINLY AT THE OUTER MARGIN OF THE SOUTH CAROLINA
COASTAL WATERS AND BEYOND 5-10 MILES FROM SHORE ACROSS THE NC
WATERS. THE CULPRIT IS A 1500+ MILE EASTERLY FETCH ACROSS MOST OF
THE WESTERN ATLANTIC PRODUCED BY 1035 MB HIGH PRESSURE SOUTH OF
NEWFOUNDLAND CANADA. AS THIS HIGH WEAKENS AND THE SYNOPTIC FLOW
VEERS MORE SOUTHERLY WITH THE APPROACHING COLD FRONT THE FETCH
SHOULD DIMINISH CONSIDERABLY DURING THE AFTERNOON.
CHANGES WITH THIS MORNING UPDATE WERE GENERALLY MINOR...LIMITED TO
COVERAGE OF SHOWERS BASED ON CURRENT RADAR IMAGERY AND RUC/HRRR
PROGS THROUGH THE AFTERNOON.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM WEDNESDAY...SOUTHERLY FLOW AT THE START OF THE PERIOD
WILL QUICKLY BECOME WESTERLY AS PRE-FRONTAL TROUGH CROSSES THE
WATERS. STRENGTH OF OFFSHORE FLOW WILL BE LIMITED UNTIL AFTER
PASSAGE OF COLD FRONT LATER THU. PINCHED PRESSURE GRADIENT AND COLD
ADVECTION THU NIGHT AND FRI WILL LEAD TO OFFSHORE FLOW IN THE 20 TO
25 KT RANGE WITH GUSTS EXCEEDING 30 KT. GIVEN OFFSHORE TRAJECTORY
AND LIMITED FETCH CONFIDENCE IN SEAS WITHIN 20 NM REACHING 6 FT FOR
ALL ZONES IS LOW...THOUGH WIND SPEEDS ARE LIKELY TO BE ENOUGH TO
WARRANT SCA THU NIGHT AND FRI MORNING. WIND SPEEDS DECREASE LATE FRI
AND FRI NIGHT AND VEER TO NORTHEAST AS CENTER OF HIGH PRESSURE MOVES
INTO THE CENTRAL APPALACHIANS AND THE GRADIENT WEAKENS. SEAS 2 TO 4
FT EARLY THU WILL BUILD TO 4 TO 7 FT THU NIGHT AND FRI. THE DECREASE
IN SPEED AND VEERING OF WINDS LATER FRI AND FRI NIGHT WILL KNOCK
SEAS BACK TO 3 TO 5 FT FOR THE LATER HALF OF THE PERIOD.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 230 AM WEDNESDAY...HIGH PRESSURE WILL DOMINATE THE
PERIOD...BROKEN BY PASSAGE OF RELATIVELY WEAK COLD FRONT SAT NIGHT
INTO SUN. WINDS AND SEAS WILL BE DECREASING SAT AS HIGH PRESSURE
SETTLES OVER THE WATERS AND THEN DRIFTS TO THE SOUTH SAT NIGHT.
PASSAGE OF COLD FRONT LATE SAT NIGHT IS LIKELY TO BE MORE OF A WIND
SHIFT THAN A TRUE FRONTAL PASSAGE. THERE WILL BE A SLIGHT INCREASE
IN WINDS BEHIND THE FRONT AS GRADIENT BECOMES A LITTLE MORE DEFINED
AND SLIGHTLY COOLER AIR BUILDS IN. SPEEDS WILL INCREASE FROM AROUND
10 KT ON SAT TO 10 TO 15 KT FOR SUN. SEAS WILL VARY FROM AROUND 2 FT
TO 2 TO 3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR AMZ254-256.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ250-
252.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...43
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1247 PM CST WED NOV 6 2013
.UPDATE...
ISSUED AT 1247 PM CST WED NOV 6 2013
MID-LEVEL CLOUD COVER HAS BECOME MORE CUMULIFORM AND IS MOVING MORE
RAPIDLY TO THE EAST-SOUTHEAST THAN PREVIOUS RAP GUIDANCE. AS A
RESULT...ADJUSTED SKY GRIDS TO MATCH LATEST TRENDS WITH CLEARING
ACROSS MUCH OF THE FORECAST AREA BY EARLY EVENING. CLOUDS HAVE
MADE A SMALL DENT IN TEMPERATURES...SO DECREASED AFTERNOON HIGHS A
DEGREE OR TWO IN PLACES. REST OF THE FORECAST OK.
UPDATE ISSUED AT 1007 AM CST WED NOV 6 2013
FORECAST AREA WILL REMAIN IN NORTHWEST FLOW ALOFT TODAY AS MAIN
TROUGH AXIS SLIDES TO THE EAST. A WEAK SURFACE LOW WILL ALSO
DRIFT ACROSS ND WITHIN A MORE DISORGANIZED AREA OF HIGH PRESSURE.
NO PRECIPITATION EXPECTED WITH THIS PATTERN...BUT THERE IS AN AREA
OF MID CLOUDS ACROSS MOST OF EASTERN ND AND INTO NORTHWEST MN THAT
IS MOVING TO THE EAST AROUND 10 TO 15 MPH. RAP 850 TO 700 HPA RH
HANDLES THIS WELL AND SUGGESTS CLOUD COVER WILL HOLD TOGETHER FOR
MUCH OF THE DAY AS IT SLOWLY MOVES INTO WEST CENTRAL MN. FOR
THIS...INCREASED SKY COVER A BIT MORE THROUGH MID-AFTERNOON. WILL
HAVE TO WATCH HOW THIS IMPACTS TEMPERATURES...BUT FOR NOW MADE
ONLY MINOR CHANGES BASED ON THE BEST PERFORMING BIAS CORRECTED NAM
AND RAP GUIDANCE. REMAINDER OF THE FORECAST IN GOOD SHAPE WITH NO
CHANGES NEEDED AT THIS TIME.
UPDATE ISSUED AT 632 AM CST WED NOV 6 2013
WILL INCREASE CLOUD COVERAGE FOR TODAY AS AN AREA OF MID-LEVEL
CIGS IS SLOWLY MOVING THROUGH THE REGION. THIS SHOULD NOT AFFECT
THE MAX TEMP FORECAST.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 330 AM CST WED NOV 6 2013
NORTHWEST FLOW ALOFT EXPECTED WITH FAST MOVING WEAK UPPER WAVES.
THE AIRMASS WILL REMAIN VERY DRY WITH ONLY MID-UPPER CLOUDS
RESULTING FROM THESE UPPER WAVES. TEMPERATURES SHOULD REMAIN
SIMILAR TO PREVIOUS DAYS. CLOUDS WILL BE TRICKY TO FORECAST...AND
WILL HAVE THE MOST IMPORTANCE ON THE TEMPERATURE FORECAST. DURING
THE OVERNIGHT HOURS...EVEN THOUGH THERE MAY BE CLOUDS...ALSO THINK
THAT THERE WILL BE PERIODS OF CLEAR SKIES. THIS WOULD ALLOW THE
TEMPERATURE TO DROP TO NEAR THE COLDER GUIDANCE (MUCH LIKE WHAT IS
CURRENTLY OCCURRING).
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM CST WED NOV 6 2013
THURSDAY NIGHT-FRIDAY NIGHT...UPPER FLOW WILL BECOME MORE ZONAL
AHEAD OF A STRONGER WAVE EJECTING FROM THE PAC NW. CONFIDENCE IS
STILL LOW WITH REGARDS TO DETAILS ON FRIDAY WITH THE PASSAGE OF
THE THIS WAVE. THE MAIN SIGNAL THAT THE MODELS ARE GIVING IS THAT
THERE MAY BE TWO UPPER WAVES...ONE ACROSS SOUTHERN CANADA...AND
ANOTHER ACROSS THE NORTHERN CONUS. THE INTERACTIONS BETWEEN THESE
TWO WAVES ARE LIKELY CAUSING THE MODEL DIFFERENCES. WILL KEEP THE
HIGHER END CHANCE POPS WITH RAIN OR SNOW POSSIBLE.
SATURDAY-TUESDAY...THERE REMAINS FAIR AGREEMENT WITH THE MODELS
IN THE TIME FRAME TO BRING DOWN A WEAK WAVE WITH CHC POPS UNDER NW
500MB FLOW ALOFT ON SUNDAY NIGHT. A COLD 1040MB SFC HIGH PRESSURE
ON MON/TUES WILL ESCORT DOWN BELOW NORMAL TEMPS TO THE NORTHERN
PLAINS. HOW COLD DEPENDS ON TRACK OF THE CENTER OF THE HIGH WHERE
GFS IS FARTHER NORTHEAST KEEPING THE STRONGEST PORTION OF THE COLD
POOL IN MANITOBA/QUEBEC AND DROPPING SOUTH OVER THE GREAT LAKES.
ECMWF IS A BIT FARTHER SOUTH AND REMAINS COOL BUT NOT AS COLD FOR
THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1247 PM CST WED NOV 6 2013
MID LEVEL CLOUD DECK TO CONTINUE TO SHIFT SE AND THIN REMAINDER OF
THIS AFTERNOON AND EVENING. MVFR SC DECK OVER NE CORNER OF THE
FORECAST AREA NOT MAKING MUCH PROGRESS SOUTHWARD AND HAVE LEFT OUT
OF THE BJI TAF BUT MAY NEED TO BE MONITORED. REMAINDER OF THE AREA
VFR THROUGH THE FORECAST PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...ROGERS
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...VOELKER
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1007 AM CST WED NOV 6 2013
.UPDATE...
ISSUED AT 1007 AM CST WED NOV 6 2013
FORECAST AREA WILL REMAIN IN NORTHWEST FLOW ALOFT TODAY AS MAIN
TROUGH AXIS SLIDES TO THE EAST. A WEAK SURFACE LOW WILL ALSO
DRIFT ACROSS ND WITHIN A MORE DISORGANIZED AREA OF HIGH PRESSURE.
NO PRECIPITATION EXPECTED WITH THIS PATTERN...BUT THERE IS AN AREA
OF MID CLOUDS ACROSS MOST OF EASTERN ND AND INTO NORTHWEST MN THAT
IS MOVING TO THE EAST AROUND 10 TO 15 MPH. RAP 850 TO 700 HPA RH
HANDLES THIS WELL AND SUGGESTS CLOUD COVER WILL HOLD TOGETHER FOR
MUCH OF THE DAY AS IT SLOWLY MOVES INTO WEST CENTRAL MN. FOR
THIS...INCREASED SKY COVER A BIT MORE THROUGH MID-AFTERNOON. WILL
HAVE TO WATCH HOW THIS IMPACTS TEMPERATURES...BUT FOR NOW MADE
ONLY MINOR CHANGES BASED ON THE BEST PERFORMING BIAS CORRECTED NAM
AND RAP GUIDANCE. REMAINDER OF THE FORECAST IN GOOD SHAPE WITH NO
CHANGES NEEDED AT THIS TIME.
UPDATE ISSUED AT 632 AM CST WED NOV 6 2013
WILL INCREASE CLOUD COVERAGE FOR TODAY AS AN AREA OF MID-LEVEL
CIGS IS SLOWLY MOVING THROUGH THE REGION. THIS SHOULD NOT AFFECT
THE MAX TEMP FORECAST.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 330 AM CST WED NOV 6 2013
NORTHWEST FLOW ALOFT EXPECTED WITH FAST MOVING WEAK UPPER WAVES.
THE AIRMASS WILL REMAIN VERY DRY WITH ONLY MID-UPPER CLOUDS
RESULTING FROM THESE UPPER WAVES. TEMPERATURES SHOULD REMAIN
SIMILAR TO PREVIOUS DAYS. CLOUDS WILL BE TRICKY TO FORECAST...AND
WILL HAVE THE MOST IMPORTANCE ON THE TEMPERATURE FORECAST. DURING
THE OVERNIGHT HOURS...EVEN THOUGH THERE MAY BE CLOUDS...ALSO THINK
THAT THERE WILL BE PERIODS OF CLEAR SKIES. THIS WOULD ALLOW THE
TEMPERATURE TO DROP TO NEAR THE COLDER GUIDANCE (MUCH LIKE WHAT IS
CURRENTLY OCCURRING).
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM CST WED NOV 6 2013
THURSDAY NIGHT-FRIDAY NIGHT...UPPER FLOW WILL BECOME MORE ZONAL
AHEAD OF A STRONGER WAVE EJECTING FROM THE PAC NW. CONFIDENCE IS
STILL LOW WITH REGARDS TO DETAILS ON FRIDAY WITH THE PASSAGE OF
THE THIS WAVE. THE MAIN SIGNAL THAT THE MODELS ARE GIVING IS THAT
THERE MAY BE TWO UPPER WAVES...ONE ACROSS SOUTHERN CANADA...AND
ANOTHER ACROSS THE NORTHERN CONUS. THE INTERACTIONS BETWEEN THESE
TWO WAVES ARE LIKELY CAUSING THE MODEL DIFFERENCES. WILL KEEP THE
HIGHER END CHANCE POPS WITH RAIN OR SNOW POSSIBLE.
SATURDAY-TUESDAY...THERE REMAINS FAIR AGREEMENT WITH THE MODELS
IN THE TIME FRAME TO BRING DOWN A WEAK WAVE WITH CHC POPS UNDER NW
500MB FLOW ALOFT ON SUNDAY NIGHT. A COLD 1040MB SFC HIGH PRESSURE
ON MON/TUES WILL ESCORT DOWN BELOW NORMAL TEMPS TO THE NORTHERN
PLAINS. HOW COLD DEPENDS ON TRACK OF THE CENTER OF THE HIGH WHERE
GFS IS FARTHER NORTHEAST KEEPING THE STRONGEST PORTION OF THE COLD
POOL IN MANITOBA/QUEBEC AND DROPPING SOUTH OVER THE GREAT LAKES.
ECMWF IS A BIT FARTHER SOUTH AND REMAINS COOL BUT NOT AS COLD FOR
THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 632 AM CST WED NOV 6 2013
MID-LEVEL CIGS WILL AFFECT THE REGION TODAY. WILL NEED TO KEEP AN
EYE ON KBJI AS THERE ARE MVFR CIGS MOVING TOWARD THIS AREA FROM THE
NORTH. CURRENT THINKING IS THAT THESE CIGS WILL JUST MISS THIS
SITE...BUT IT WILL BE CLOSE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...ROGERS
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...TG
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1104 PM CST TUE NOV 5 2013
.AVIATION...
WILL CONTINUE WITH THE IFR CEILINGS OVERNIGHT UNTIL FROPA. SHRA
ACTIVITY STARTING TO INCREASE IN AREAL COVERAGE SO WILL CHANGE THE
-DZ TO -RA...NOT MUCH DIFFERENCE. THUNDER STILL LOOKS LIKE A VERY
LOW PROBABILITY AND TAFS WILL CONTINUE TO HAVE NO MENTION OF TSRA.
WILL ADJUST FROPA TIMING UP TO 11Z IN METROPLEX AND 13Z IN WACO
BASED ON LATEST RAP SOUNDINGS. 84
&&
.PREV DISCUSSION... /ISSUED 248 PM CST TUE NOV 5 2013/
A BROAD AREA OF LIGHT RAIN CONTINUES TO STREAM NORTHEAST ACROSS
THE CWA THIS AFTERNOON. LIKELY POPS WILL CONTINUE IN THE FORECAST
THIS AFTERNOON FOR THE NORTHEASTERN QUADRANT OF THE CWA THROUGH
00Z AND WILL THEN TRANSITION THE LIKELY POPS EVEN FARTHER
NORTHEAST BETWEEN 00Z AND 06Z. THIS RAIN SHIELD IS IN RESPONSE TO
CONTINUED WEAK WARM-AIR ADVECTION AND WILL LIKELY REMAIN WITHOUT
ANY THUNDERSTORMS.
THE FOCUS WILL THEN TURN TO THE COLD FRONT EXPECTED TO MOVE INTO
NORTH TEXAS TOMORROW MORNING. AT 2 PM...THE FRONT WAS JUST ABOUT
TO ENTER THE TEXAS PANHANDLE. GUIDANCE IS CONSISTENT WITH THE
FRONT ENTERING OUR NORTHWESTERN COUNTIES JUST BEFORE 3 AM. IT WILL
THEN PUSH THROUGH THE METROPLEX BETWEEN 6 AND 8 AM...THEN REACH
WACO/TEMPLE/KILLEEN AROUND 9 AM AND THEN THROUGH THE REST OF THE
CWA BY NOON. AHEAD OF THE FRONT SCATTERED SHOWERS WILL LIKELY
CONTINUE TONIGHT AS WEAK ISENTROPIC LIFT CONTINUES. EXPECT A WEAK
LINE OF SHOWERS AND PERHAPS A THUNDERSTORM TO DEVELOP ALONG THE
FRONT LATER TONIGHT IN OKLAHOMA. THIS LINE OF PRECIP WILL CONTINUE
THROUGH MUCH OF THE CWA AS THE FRONT PROGRESSES THROUGH THE CWA.
THE TTU WRF HAS BEEN CONSISTENTLY FORECASTING VERY LITTLE RAIN
OVERNIGHT WITH THE FRONT...AND THIS IS SOMEWHAT WORRISOME.
EVEN THOUGH IT DOES SHOW LESS ACTIVITY...RAIN CHANCES ARE STILL
HIGH...BUT RAIN AMOUNTS WOULD SUFFER IF THIS SOLUTION VERIFIES.
LOW AND HIGH TEMPERATURES TONIGHT AND TOMORROW WILL BE HIGHLY
DEPENDENT ON THE FRONTAL PASSAGE AS TEMPERATURES SHOULD DECREASE
IMMEDIATELY BEHIND THE FRONT WITH TEMPERATURES TOMORROW AFTERNOON
HOLDING STEADY IN THE 50S TO NEAR 60 DEGREES. ALL PRECIP SHOULD BE
ENDED BY LATE AFTERNOON AND A QUIET NIGHT IS EXPECTED.
TEMPERATURES BY THURSDAY MORNING SHOULD BE QUITE COLDER WITH MID
TO UPPER 30S LIKELY ACROSS THE NORTHERN AND NORTHWESTERN ZONES.
WITH LIGHT WINDS...PATCHY FROST MAY BE POSSIBLE FOR THESE
LOCATIONS. HIGHS THURSDAY WILL REBOUND INTO THE MIDDLE TO UPPER
60S WITH MOSTLY CLEAR SKIES. THE WEATHER PATTERN WILL TRANSITION
TO NEARLY ZONAL FLOW IN THE CENTRAL PLAINS WITH WEAK SOUTHWEST
FLOW OVER TEXAS BEGINNING FRIDAY. THIS SOUTHWEST FLOW WILL ALLOW
SEVERAL WEAK DISTURBANCES TO TRANSLATE ACROSS NORTH TEXAS. THE
FIRST IS EXPECTED FRIDAY NIGHT AND SATURDAY...BUT MOISTURE IS
EXPECTED TO BE TOO LIMITED FOR ANY PRECIP TO REACH THE GROUND.
ANOTHER WILL ARRIVE FOR MONDAY/TUESDAY AND MOISTURE SHOULD BE
SUFFICIENT FOR SOME RAIN AND WILL INTRODUCE 20 POPS IN THE
FORECAST.
HAMPSHIRE
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 57 62 42 67 45 / 100 50 0 0 5
WACO, TX 63 66 40 68 42 / 90 60 5 5 5
PARIS, TX 60 62 36 64 40 / 100 70 10 0 5
DENTON, TX 55 61 37 65 39 / 100 40 0 0 5
MCKINNEY, TX 58 61 37 64 41 / 100 50 0 0 5
DALLAS, TX 58 63 43 66 46 / 100 50 5 0 5
TERRELL, TX 62 64 41 64 42 / 100 60 5 0 5
CORSICANA, TX 63 68 42 66 44 / 90 60 5 5 5
TEMPLE, TX 64 68 40 66 43 / 80 60 10 5 5
MINERAL WELLS, TX 51 62 37 66 39 / 80 40 0 0 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS SPOKANE WA
420 AM PST Wed Nov 6 2013
.SYNOPSIS...
A wet storm system is expected for tonight into Thursday. This
storm system will be milder with rain in the valleys and snow for
the mountains. Gusty winds will be likely. Cool, showery, and
unstable conditions will be coming for the weekend and into next
week.
&&
.DISCUSSION...
Today and Tonight..Anti-cyclonic curved ridge axis and associated
jet stream will remain parked over the Inland Northwest this
morning...with a weak shortwave trough embedded on the left front
quadrant of the jet over NE Washington. This shortwave is expected
to weaken significantly this morning as it dips slowly to the
southeast while the upper level jet begins to buckle northward
into BC. However as long as the shortwave persists it will still
be able to tap into a very moist surface-700 mb layer and should be
able to wring light precipitation out of the atmosphere. Radar loops
this morning have consistently shown showers over the Idaho
Panhandle ahead of this feature...and the models have not handled it
all that well. Fortunately the RUC model seems to buck that trend.
If we follow its solution...the low level southwest winds ahead of
the trough which are leading to good isentropic and orographic
ascent will gradually turn to the northwest and allow drier air to
spill into the area. This will result in a decreasing shower threat
through the morning...but up to an inch of snow is certainly
possible before all is said and done. Most of the snow will occur
over eastern sections of Kootenai, Benewah, Latah counties as well
as most of Shoshone County but above valley elevations as surface
temps are generally above freezing. Farther west...there is a
widespread stratus deck that will likely remain in place through
much of the day and could continue to produce some light drizzle
early as weak ascent will persist through a much shallower moist
layer. Otherwise...the weather looks rather benign for much of the
day.
For late this afternoon and tonight...the break in the weather will
come to an end as the ridge axis shifts east of the forecast area
and a warm front moves into the area from the southwest. This
front will bring a significant influx of moisture and a rapid
increase in the chances for precipitation overnight. Warmer air
will also filter into the area....and snow levels will steadily
rise from around 3-4k feet late this afternoon (lower across the
northeast Cascades) to nearly 6-7.5k by early Thursday morning.
That means the precipitation will largely fall as rain over all
valley locations...however lower snow levels will persist over the
northeast Cascades due to cold air damming and the warm air won`t
quite make it to the Canadian border by morning. The heaviest
amounts of precipitation will likely fall near the Cascade Crest
due to persistent south-southeast 850 mb flow. Values there could
range from .25-.60"...much of which will fall as snow at elevations
at or above 3500 feet. This will likely impact the passes in that
area...including the North Cascades Highway...Loup Loup and Stevens
Passes with heavy snow possible. That threat will continue through
Thursday and consequently we have issued a winter weather advisory
for snow. Just how fast the cold air can mix out will be the big
question and will largely determine how much snow accumulates. Looks
like the cold air will remain most stubborn north of Lake Chelan and
impact portions of the North Cascade Highway. Elsewhere look for
widespread rain to impact most areas overnight with amounts ranging
from .05 to .15 inches. fx
Thursday through Sunday night...Very moist low pressure system will
bring increasing precipitation to the Inland Northwest on
Thursday. A subtropical moisture tap will be drawn into the area
which combined with isentropic lift leads to a high confidence
forecast of all areas getting precip. The flow at 850mb will back
to the south Thursday morning with warmer air spreading into the
region with snow levels rising to 6000-7000 feet from Wenatchee to
Spokane to Kellogg and points south resulting in rain even in most
mountains south of this line. As usual colder air will be tough
to scrub near the Canadian border with GFS and NAM showing wet
bulb zero heights near 3000 feet in the morning...but should
eventually rise to 5000 feet in the afternoon as warmer air
continues to push northward with 850mb winds out of the south at
30-40 knots. The cold front moves into the region in the afternoon
for continued wet conditions...with the front exiting the Idaho
Panhandle early Thursday evening. Precipitation totals from the
models show 1-1.5 inches for the Cascade crest, around an inch for
the Idaho Panhandle, and 0.5-1.00 inches for Eastern
Washington...with up to a half inch for the Wenatchee area and
Columbia Basin. These values make sense given the subtropical
moisture tap.
Following the cold front moist zonal flow will favor showers in
the orographic favored areas of the Cascade crest and Idaho
Panhandle. Snow levels behind the front fall to 3000-4000 feet
supporting the potential for light snow accumulations for the
Cascade passes and Lookout Pass Thursday night. Breezy winds are
also expected behind the front on the palouse and in the Blue
Mountains where the strongest pressure gradient and instability
will be. In fact the NAM shows a marginal thunder threat in these
areas with the front passage late Thursday afternoon and evening.
For now will leave thunder out due to low confidence of this
occurring at this time. Another fast moving wave tracks through
in the zonal flow Friday which will likely enhance the shower
activity in the favored west flow upslope areas with a chance of
showers backfilling into Eastern Washington. Downslope should
dominate in the lee of the Cascades with Wenatchee, Omak, and
Moses Lake likely remaining dry on Friday. Friday night into
Saturday generally dry weather is favored as the next low pressure
system drops south along 140W building a weak ridge over the
Inland Northwest.
Saturday night through Sunday night models show increased moisture
moving in with the GFS lifting a warm front into the area while the
ECMWF shows a stalled frontal boundary over Eastern Washington and
North Idaho. While there are differences in the details the trend
will be for increasing precipitation chances. Snow levels look to
remain above valley floors except for elevations above 2000-2500
feet along the East Slopes of the Cascades and near the Canadian
Border where wet snow is possible in the higher valleys. JW
Monday and Tuesday: Monday is expected to be pretty quiet with
a ridge pattern dominating the region. The models are indicating
a Low approaching the Pacific Coast as the ridging breaks down.
The timing of the system is expected to be on Monday evening and
bring a warm front through the region. Rain showers are expected for
the Lower Columbia Basin. The higher elevations will get snow and
the valleys will be impacted by a rain/snow mix. The temperatures
are expected to be in line with the prior days. /JDC
&&
.AVIATION...
12Z TAFS: Yet another low confidence forecast is at hand as stratus
and IFR/MVFR cigs will impact every forecast site at least through
18z. Most of the ceiling heights this morning were right around 1k
feet...and are expected rapidly vacillate on either side of that
critical IFR/MVFR threshold. Generally speaking through...we should
see a slow lifting of the ceiling heights through 18z. None of the
sites will experience any weather aside from COE...where some light
snow showers will remain possible through 16z or so. By
afternoon...we expect much of the lower stratus to break up...and
most sites will briefly improve into the VFR category. We went with
timing this improvement around 18z...based on conditional
climatology and BUFKIT data...however would not be terribly
surprised if things persist a little past that time. Between 00z-06z
tonight...the stratus will certainly breakup with the approach of a
strong warm front. This will gradually spread rain from SW to NE
overnight...and ceilings will once again likely lower to MVFR
heights. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 42 36 45 37 45 31 / 10 60 100 60 40 20
Coeur d`Alene 41 35 43 36 44 31 / 20 60 100 80 60 30
Pullman 44 39 47 38 45 33 / 10 40 100 70 40 20
Lewiston 48 41 51 42 52 35 / 10 40 90 60 30 20
Colville 44 34 41 36 46 31 / 10 80 100 50 40 20
Sandpoint 41 33 41 35 43 31 / 10 60 100 80 80 40
Kellogg 41 34 42 35 39 31 / 30 70 100 100 80 40
Moses Lake 45 38 48 35 53 30 / 10 50 80 20 10 10
Wenatchee 43 35 45 36 51 33 / 10 50 70 10 10 10
Omak 43 35 42 33 47 29 / 0 70 100 20 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Winter Weather Advisory from 4 PM this afternoon to 4 PM PST
Thursday for East Slopes Northern Cascades.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
303 AM PST Wed Nov 6 2013
.SYNOPSIS...
A wet storm system is expected for tonight into Thursday. This
storm system will be milder with rain in the valleys and snow for
the mountains. Gusty winds will be likely. Cool, showery, and
unstable conditions will be coming for the weekend and into next
week.
&&
.DISCUSSION...
Today and Tonight..Anti-cyclonic curved ridge axis and associated
jet stream will remain parked over the Inland Northwest this
morning...with a weak shortwave trough embedded on the left front
quadrant of the jet over NE Washington. This shortwave is expected
to weaken significantly this morning as it dips slowly to the
southeast while the upper level jet begins to buckle northward
into BC. However as long as the shortwave persists it will still
be able to tap into a very moist surface-700 mb layer and should
be able to wring precipitation out of the atmosphere. Radar loops
this morning have consistently shown showers over the Idaho
Panhandle ahead of this feature...and the models have not handled
it all that well. Fortunately the RUC model seems to buck that
trend. If we follow its solution...the low level southwest winds
ahead of the trough which are leading to good isentropic and
orographic ascent will gradually turn to the northwest and allow
drier air to spill into the area. This will result in a decreasing
shower threat through the morning...but up to an inch of snow is
certainly possible before all is said and done. Most of the snow
will occur over eastern sections of Kootenai, Benewah, Latah
counties as well as most of Shoshone County but above valley
elevations as surface temps are generally above freezing. Farther
west...there is a widespread stratus deck that will likely remain
in place through much of the day and could continue to produce
some light drizzle early as weak ascent will persist through a
much shallower moist layer. Otherwise...the weather looks rather
benign for much of the day.
For late this afternoon and tonight...the break in the weather will
come to an end as the ridge axis shifts east of the forecast area
and a warm front moves into the area from the southwest. This
front will bring a significant influx of moisture and a rapid
increase in the chances for precipitation overnight. Warmer air
will also filter into the area....and snow levels will steadily
rise from around 3-4k feet late this afternoon (lower across the
northeast Cascades) to nearly 6-7.5k by early Thursday morning.
That means the precipitation will largely fall as rain over all
valley locations...however lower snow levels will persist over the
northeast Cascades due to cold air damming and the warm air won`t
quite make it to the Canadian border by morning. The heaviest
amounts of precipitation will likely fall near the Cascade Crest
due to persistent south-southeast 850 mb flow. Values there could
range from .25-.60" much of which will fall as snow at elevations
at or above 3500 feet. This will likely impact the passes in that
area...including Rainy...Loup Loup and Stevens with heavy snow
possible. That threat will continue through Thursday and
consequently we have issued a winter weather advisory for snow.
Just how fast the cold air can mix out will be the big question
and will largely determine how much snow accumulates. Looks like
the cold air will remain most stubborn along the North Cascade
Highway. Elsewhere look for widespread precipitation to impact
most areas overnight. fx
Thursday through Sunday night...Very moist low pressure system will
bring increasing precipitation to the Inland Northwest on
Thursday. A subtropical moisture tap will be drawn into the area
which combined with isentropic lift leads to a high confidence
forecast of all areas getting precip. The flow at 850mb will back
to the south Thursday morning with warmer air spreading into the
region with snow levels rising to 6000-7000 feet from Wenatchee to
Spokane to Kellogg and points south resulting in rain even in most
mountains south of this line. As usual colder air will be tough
to scrub near the Canadian border with GFS and NAM showing wet
bulb zero heights near 3000 feet in the morning...but should
eventually rise to 5000 feet in the afternoon as warmer air
continues to push northward with 850mb winds out of the south at
30-40 knots. The cold front moves into the region in the afternoon
for continued wet conditions...with the front exiting the Idaho
Panhandle early Thursday evening. Precipitation totals from the
models show 1-1.5 inches for the Cascade crest, around an inch for
the Idaho Panhandle, and 0.5-1.00 inches for Eastern
Washington...with up to a half inch for the Wenatchee area and
Columbia Basin. These values make sense given the subtropical
moisture tap.
Following the cold front moist zonal flow will favor showers in
the orographic favored areas of the Cascade crest and Idaho
Panhandle. Snow levels behind the front fall to 3000-4000 feet
supporting the potential for light snow accumulations for the
Cascade passes and Lookout Pass Thursday night. Breezy winds are
also expected behind the front on the palouse and in the Blue
Mountains where the strongest pressure gradient and instability
will be. In fact the NAM shows a marginal thunder threat in these
areas with the front passage late Thursday afteroon and evening.
For now will leave thunder out due to low confidence of this
occurring at this time. Another fast moving wave tracks through
in the zonal flow Friday which will likely enhance the shower
activity in the favored west flow upslope areas with a chance of
showers backfilling into Eastern Washington. Downslope should
dominate in the lee of the Cascades with Wenatchee, Omak, and
Moses Lake likely remaining dry on Friday. Friday night into
Saturday generally dry weather is favored as the next low pressure
system drops south along 140W building a weak ridge over the
Inland Northwest.
Saturday night through Sunday night models show increased moisture
moving in with the GFS lifting a warm front into the area while the
ECMWF shows a stalled frontal boundary over Eastern Washington and
North Idaho. While there are differences in the details the trend
will be for increasing precipitation chances. Snow levels look to
remain above valley floors except for elevations above 2000-2500
feet along the East Slopes of the Cascades and near the Canadian
Border where wet snow is possible in the higher valleys. JW
Monday and Tuesday: Monday is expected to be pretty quiet with
a ridge pattern dominating the region. The models are indicating
a Low approaching the Pacific Coast as the ridging breaks down.
The timing of the system is expected to be on Monday evening and
bring a warm front through the region. Rain showers are expected for
the Lower Columbia Basin. The higher elevations will get snow and
the valleys will be impacted by a rain/snow mix. The temperatures
are expected to be in line with the prior days. /JDC
&&
.AVIATION...
06Z TAFS: Primarily IFR/LIFR conditions expected to linger in the
stable environment behind the exiting system, impacting the KGEG
to KCOE and KPUW area. Some -sn/-fzdz/-dz will affect extreme NE
WA and the northern panhandle overnight and possibly in the vcnty
of these sites as well, but the threat will diminish overnight.
Conditions may be slow to improve through the day Wednesday,
potentially not improving beyond IFR/MVFR conditions until after
noon. KMWH/KEAT is expected to remain IFR/MVFR through the night,
with possible fog development though 20Z. KLWS is expected to
degrade toward MVFR through the night, with some improvement in
the morning. Confidence is lower for conditions in vcnty of
KEAT/KMWH/KLWS. The next wet weather system will push into the
KEAT area just before 06Z Thursday. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 42 36 45 37 45 31 / 10 60 100 60 40 20
Coeur d`Alene 41 35 43 36 44 31 / 20 60 100 80 60 30
Pullman 44 39 47 38 45 33 / 10 40 100 70 40 20
Lewiston 48 41 51 42 52 35 / 10 40 90 60 30 20
Colville 44 34 41 36 46 31 / 10 80 100 50 40 20
Sandpoint 41 33 41 35 43 31 / 10 60 100 80 80 40
Kellogg 41 34 42 35 39 31 / 30 70 100 100 80 40
Moses Lake 45 38 48 35 53 30 / 10 50 80 20 10 10
Wenatchee 43 35 45 36 51 33 / 10 50 70 10 10 10
Omak 43 35 42 33 47 29 / 0 70 100 20 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Winter Weather Advisory from 4 PM this afternoon to 4 PM PST
Thursday for East Slopes Northern Cascades.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
334 AM CST WED NOV 6 2013
.SHORT TERM...(TODAY AND TONIGHT)
333 AM CST WED NOV 6 2013
MAIN FORECAST CONCERNS THIS PACKAGE...EXITING RAIN/DZ/SOME -SN
THIS MORNING...CLOUD TRENDS THIS AFTERNOON...TEMPERATURES.
06Z DATA ANALYSIS HAD AN AREA OF LOW PRESSURE CENTERED NEAR OELWEIN
IA...LIFTING QUICKLY NORTHEAST ALONG A FRONT FROM NEAR KGRB TO
KALO. STRONGEST OF THE SFC-700MB FORCING/LIFT WAS TRANSLATING
QUICKLY NORTHEAST WITH THE LOW...WITH PRECIP ALREADY TAPERING OFF/
ENDING ACROSS THE WEST 1/3 OF THE FCST AREA. DEFORMATION BAND OF
MAINLY -SN WEST/NORTH OF THE FCST AREA WAS DECREASING AS WELL.
TEMP GRADIENT ACROSS THE FRONT QUITE IMPRESSIVE EARLY THIS
MORNING...WITH MID 50S INTO SOUTHWEST WI AHEAD OF IT TO UPPER
30S/LOW 40S ONLY 30 MILES NORTHWEST OF THE BOUNDARY. DECREASING
CLOUDS/CLEARING ALREADY SPREADING INTO WESTERN MN.
MODEL RUNS OF 06.00Z INITIALIZED VERY WELL AND OFFER A TIGHT
CONSENSUS OF SOLUTIONS FOR TODAY/TONIGHT. THIS TIGHT CONSENSUS
AGAIN FAVORS THE FASTER OF THE EARLIER RUNS AS THE PLAINS TROUGH
QUICKLY SWINGS THRU THE REGION TODAY. TREND APPEARS A BIT WEAKER
WITH THE NORTHWEST FLOW SHORTWAVE TO DROP DOWN THE WEST SIDE OF THE
BROADER TROUGH AND INTO MN TONIGHT. CHECK OF OBS VS. MODEL DATA AT
06Z SHOWED ALL TO BE REASONABLE WITH THE NORTHEAST IA SFC LOW.
MODELS QUITE GOOD WITH THE SHARP TEMP CONTRAST ACROSS THE FRONT
THRU WI/IA. MODELS ALL TRENDING WELL WITH THE BULK OF THE PRECIP
SHIFTING EAST OF THE AREA. PER WV IMAGERY ALL APPEARED GOOD WITH
THE MID LEVEL TROUGH/SHORTWAVE ENERGY PROGRESSING RATHER QUICKLY
ACROSS THE CENTRAL/NORTHERN PLAINS. GIVEN THE TIGHTENING CONSENSUS
AND NO GLARING ERRORS...FAVORED THE MODEL/ENSEMBLE CONSENSUS WITH
SHORT TERM FCST CONFIDENCE REMAINING GOOD.
FASTER TREND OF MODEL CONSENSUS CONTINUES TO SHIFT THE DEEPER
MOISTURE/LIFT EAST OF THE AREA MORE QUICKLY THRU THIS MORNING...
WITH THE FCST AREA NOW LOOKING TO BE PRECIP-FREE BY 18Z. HAVE
TRENDED FCST GRIDS FOR THE FASTER PRECIP EXIT. WITH DECREASING
DEPTH OF MOISTURE AND LOSS OF ICE IN THE CLOUDS...CARRIED ANY
PRECIP THIS MORNING AS DRIZZLE. BIGGER QUESTION TODAY IS HOW
QUICKLY WILL SUNSHINE RETURN TO THE FCST AREA. STRONG MODEL
SIGNAL/CONSENSUS FOR DEEP/STRONG DRYING TO SPREAD ACROSS THE FCST
AREA IN DEEP SUBSIDENCE BEHIND THE 850-500MB TROUGH AXIS PASSAGE.
MODEL SOUNDINGS/X-SECTIONS SHOW THIS TO NEAR A KMDZ-KLSE-
STRAWBERRY POINT IA LINE BY 18Z. GIVEN OBS/SATELLITE TRENDS OVER
WESTERN MN...THIS SEEMS QUITE REASONABLE AND TRENDED GRIDS FOR
MORE RAPID CLEARING TODAY. CLEAR/MOSTLY CLEAR SKIES EXPECTED
ACROSS THE ENTIRE FCST AREA BY LATE AFTERNOON. SUNSHINE THIS
AFTERNOON WILL OFFSET THE LOW LEVEL COLD ADVECTION WITH NEARLY
STEADY TEMPS THIS AFTERNOON. MIXING TO 925-900MB TODAY...FOR SOME
BRISK NORTHWEST WINDS IN THE WAKE OF THE LOW.
SHORTWAVE DROPPING INTO MN TONIGHT BRINGS WITH IT SOME MOISTURE
BETWEEN 850-700MB. SFC REFLECTION WITH THIS FEATURE WEAKENS THRU
THE NIGHT AND ANY SFC-700MB FORCING/LIFT IS QUITE WEAK. LITTLE MORE
THAN SCT-BKN 5K-8K FT CLOUDS EXPECTED. WITH WEAKER WINDS AS THE
WEAK SFC TROUGH DROPS INTO THE AREA LATER TONIGHT AND THE RECENT
RAINS...SOME POTENTIAL FOR BR/FG OVER THE WEST END OF THE FCST AREA
LATE TONIGHT AND ADDED A PATCHY FOG MENTION FOR PORTIONS OF
SOUTHEAST MN/NORTHEAST IA. FAVORED A BLEND OF THE GUIDANCE HIGHS/
LOWS FOR TODAY/TONIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
333 AM CST WED NOV 6 2013
MAIN FORECAST CONCERNS FOR THURSDAY THROUGH FRIDAY NIGHT...MAINLY
RAIN CHANCES LATER FRI/FRI NIGHT...TEMPERATURES.
MODEL CONSENSUS CONTINUES TO TIGHTEN/IMPROVE FOR THU THRU FRI NIGHT
ON THE RATHER PROGRESSIVE FLOW PATTERN THIS PERIOD. HGTS RISE THU
WITH SHORTWAVE RIDGING TO PASS EARLY FRI AND THE FLOW TO BECOME
NEARLY ZONAL ACROSS THE NORTHERN CONUS BY LATE FRI. EMBEDDED
SHORTWAVE QUICKLY TRACKS FROM OR/WA COAST AT 18Z THU TO EAST OF THE
AREA BY 12Z SAT. GIVEN THE FAST FLOW THIS PERIOD...MODEL CONSENSUS
AS GOOD AS IT WITH THE TROUGH PASSAGE FRI NIGHT IS A BIT SURPRISING.
FCST CONFIDENCE REMAINS GOOD FOR THE THU THRU FRI NIGHT PERIOD.
SFC HIGH PRESSURE RIDGE AXIS APPROACHES/MOVES ACROSS THE REGION THU
INTO FRI MORNING. FOR DRY/QUIET/COOL WEATHER. SFC RIDGE AXIS MOVES
ACROSS THE FCST AREA THU NIGHT. IF BOUNDARY LAYER WINDS DECOUPLE AND
CAN STAY DECOUPLED THRU THE NIGHT...NOT A GUARANTEE WITH THE SFC
RIDGE AXIS MOVING QUICKLY EAST OF THE AREA AND THE PRESSURE
GRADIENT STARTING TO TIGHTEN BY 12Z FRI...SOME RADIATIONAL FOG WOULD
BE EXPECTED ACROSS THE AREA. LEFT LATE THU NIGHT/EARLY FRI MORNING
FOG MENTION OUT OF FCST GRIDS FOR NOW. SFC LOW QUICKLY MOVES INTO
WESTERN MN BY 00Z SAT. PRESSURE GRADIENT TIGHTENS OVER MUCH OF
MN/IA/WI THRU FRI...FOR SOME BRISK SOUTH WINDS AND WARMING ACROSS
MUCH OF THE REGION. MORE MOISTURE/LIFT...MAINLY ABOVE 700MB...AHEAD
OF/WITH THIS LOW/SHORTWAVE TO MOVE ACROSS THE REGION LATER FRI/FRI
NIGHT. LOW LEVEL WARM ADVECTION SENDS 925-850MB TEMPS ABOVE 0C ACROSS
THE AREA FOR FRI AFTERNOON/NIGHT...WITH BULK OF ANY PRECIP CHANCE
THESE PERIODS AS -RA...PERHAPS MIXED WITH SOME -SN ACROSS THE FAR
NORTH END OF THE FCST AREA TOWARD 12Z SAT. QUESTION IS WILL ANY
PRECIP PRODUCED ABOVE 700MB BE ABLE TO FALL THRU THE DRIER SFC-700MB
LAYER AND REACH THE GROUND. LEFT PRECIP CHANCES FRI/FRI NIGHT IN THE
20-40 PERCENT CHANCE RANGE...HIGHEST ACROSS THE NORTH END OF THE
FCST AREA CLOSER TO THE TRACK OF THE SHORTWAVE AND DEEPER MOISTURE.
USED A MODEL CONSENSUS BLEND FOR THE HIGHS/LOWS THIS PERIOD.
FOR SATURDAY THROUGH TUESDAY.../DAYS 4 TO 7/...
MEDIUM RANGE MODEL RUNS OF 06.00Z IN GOOD AGREEMENT WITH EACH OTHER
AND THEIR PREVIOUS RUNS SAT/SAT NIGHT AS TROUGHING SLIDES EAST OF THE
REGION SAT AND BROAD RIDGING BUILDS ACROSS THE NORTH-CENTRAL CONUS
SAT NIGHT. MODELS THEN DIVERGE WITH TIMING/STRENGTH DETAILS OF A
SHORTWAVE TROUGH TO PASS NORTHEAST OF THE REGION LATER SUN INTO MON
AND YET ANOTHER NORTHERN STREAM SHORTWAVE TROUGH DROPS INTO THE
REGION TUE. RUN-TO-RUN CONSISTENCY LEAVES QUITE A BIT TO BE DESIRED
BY MON/TUE. FCST CONFIDENCE ON THE GOOD SIDE SAT...THEN ON THE LOW
SIDE FOR EARLY NEXT WEEK.
WITH IMPROVING CONSENSUS SAT FOR THE MID LEVEL TROUGH TO BE SLIDING
EAST OF THE AREA...ANY LINGERING -RA/-SN CHANCE LOOKS CONFINED TO
THE MORNING. DRY/COOL HIGH PRESSURE BUILDS ACROSS THE REGION FOR
LATER SAT THRU SUN...UNDER THE BROAD MID LEVEL RIDGING. SHORTWAVE
TROUGH TO PASS ACROSS ONT CENTERED ON SUN NIGHT DRIVES A COLD FRONT
INTO/ACROSS THE UPPER MIDWEST SUN NIGHT/MON. PLENTY OF DETAIL
DIFFERENCES ON THE TIMING OF THIS FRONT THRU THE AREA AND HOW MUCH
MOISTURE MAY ACCOMPANY IT. MAY YET NEED A SPRINKLE/FLURRY MENTION
MAINLY ALONG/NORTHEAST OF I-94 SUN NIGHT INTO MON BUT AGAIN
CONFIDENCE IN THE DETAILS IS LOW BY MON. SOME CONSENSUS THAT THE NEXT
SHORTWAVE TROUGH TO DROP TOWARD THE REGION TUE WOULD BE STRONGER
WITH MORE OF A LOWER LEVEL THERMO-DYNAMIC FORCING/LIFT RESPONSE
AND PERHAPS MORE MOISTURE. A SMALL -RA/-SN CHANCE BY TUE PER A
MODEL/ENSEMBLE COMPROMISE REASONABLE FOR NOW. BETTER CONFIDENCE IN
THE MON/TUE PERIOD FOR TEMPS TO BE BELOW NORMAL. MODEL/ENSEMBLE
CONSENSUS FOR THE SAT THRU TUE HIGHS/LOWS LOOKS WELL TRENDED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1138 PM CST TUE NOV 5 2013
SURFACE LOW HAS PROGRESSED RAPIDLY NORTHEAST AND WAS OVER
NORTHEAST IOWA LATE THIS EVENING. THE BULK OF THE RAIN CONTINUES
OUT AHEAD OF THE LOW WITH THE BACK EDGE OF THE MAIN RAIN SHIELD
STARTING TO WORK INTO THE REGION WITH THIS ALREADY COMING THROUGH
KRST. EXPECT TO SEE THE RAIN BECOME MORE SCATTERED THROUGH THE
NIGHT AS THE FORCING CONTINUES TO MOVE OUT WITH THE SURFACE LOW.
BETWEEN 09Z AND 12Z...EXPECT TO SEE THE FORCING REALLY DROP OFF
BUT STILL HAVE SOME OMEGA THROUGH THE SATURATED LOW LEVELS AND
EXPECT THIS TO PRODUCE DRIZZLE. THE 06.00Z NAM AND RAP CONTINUE TO
SUGGEST THE POSSIBILITY OF FREEZING DRIZZLE FOR KRST. HOWEVER...
THESE MODELS HAVE BEEN CONSISTENTLY TOO COLD WITH SURFACE TEMPS
THROUGH THE EVENING. IN ADDITION...THE COLDER AIR HAS BEEN SLOWLY
MOVING SOUTH ACROSS MINNESOTA AND CONCERNED THAT IT MAY NOT ARRIVE
BEFORE THE PRECIPITATION ENDS. BASED ON THESE TWO CONCERNS...CANNOT
TOTALLY RULE OUT THE POSSIBILITY OF SOME FREEZING DRIZZLE AT KRST BUT
AT THIS POINT...FEEL THE PROBABILITY OF THIS OCCURRING IS TOO LOW TO
INCLUDE IN THE FORECAST. EXPECT CEILINGS TO REMAIN IFR UNTIL ABOUT
12Z WHEN SOME DRIER LOW LEVEL AIR STARTS TO MOVE ALLOWING THESE TO
COME UP TO MVFR AND THEN EVENTUALLY SCATTER OUT BY LATE MORNING TO
EARLY AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1138 PM CST TUE NOV 5 2013
.SHORT TERM...(TONIGHT AND WEDNESDAY)
320 PM CST TUE NOV 5 2013
ATTENTION SQUARELY ON THE SYSTEM MOVING THROUGH TONIGHT AND
WEDNESDAY. WIDESPREAD RAIN TONIGHT...AND WITH COOLER AIR ON THE
BACK SIDE OF THE SYSTEM...COULD SEE A MIX OR CHANGE TO SNOW...
AND MAYBE EVEN FREEZING DRIZZLE.
20Z SURFACE ANALYSIS SHOWED THE LOW PRESSURE CENTER OVER KANSAS...
WITH A WARM FRONT REACHING NORTHEAST INTO SOUTHERN WI. WATER VAPOR
IMAGERY SHOWED A POTENT JET STREAK MOVING NORTHEAST ACROSS OK/KS.
REGIONAL RADAR LOOPS SHOW AN EXPANSIVE AREA OF RAIN REACHING FROM
IA AND NORTHERN IL UP INTO SOUTHEAST MN AND SOUTHERN WI. FROM
NORTHERN NEBRASKA INTO SD... THE RADAR IMAGERY SHOWED A MORE
LAMINAR LOOK...SUGGESTING SNOW. INDEED...LOOKING AT SURFACE
OBSERVATIONS OUT THAT WAY...SNOW WAS INDEED FLYING.
LATEST MODEL SIMULATIONS ARE IN PRETTY GOOD AGREEMENT WITH THE
OVERALL EVOLUTION OF THIS SYSTEM AS IT PROGRESSES RATHER QUICKLY
ACROSS THE REGION TONIGHT. THE LOW CENTER SHOULD BE OVER NW MO
AROUND 00Z...AND IS EXPECTED TO BE IN EASTERN WI ALREADY BY 12Z.
COPIOUS AMOUNTS OF MOISTURE AVAILABLE TO THE SYSTEM WITH
PRECIPITABLE WATER OVER 200% OF NORMAL. PRECIPITATION IS A SLAM
DUNK OBVIOUSLY...BUT THE MAIN CONCERN WITH THIS SYSTEM IS THE
POSSIBILITY OF SNOW OR FREEZING DRIZZLE AS THE COLD AIR ARRIVES ON
THE BACK SIDE OF THE SYSTEM. WITH THE TRACK OF THE STORM HEADING
OVER SOUTHERN WI OVERNIGHT...THE FORECAST AREA REMAINS MAINLY IN
THE WARM SECTOR OF THE STORM. THE ONLY AREA WHERE THIS IS NOT TRUE
IS THE FAR NORTHWEST EDGE...FROM ALBERT LEA/KASSON MN...UP THROUGH
WABASHA...TO NEAR ABBOTSFORD/MEDFORD WI. ENOUGH COLD AIR COULD
FILTER IN LATER THIS EVENING TO ALLOW FOR A MIX WITH OR CHANGE
OVER TO SNOW. STILL APPEARS THE HIGHEST THREAT FOR SIGNIFICANT
ACCUMULATIONS OF 2-5 INCHES WILL LIE JUST BEYOND THE FORECAST
AREA...BUT SOME SPOTS ALONG THE AFOREMENTIONED LINE COULD SEE SOME
BRIEF ACCUMULATIONS UP AROUND AN INCH OR SO ON GRASSY AREAS AND
OTHER EXPOSED SURFACES. THE MAIN UPWARD MOTION AND FORCING SHIFT
EAST OF THE AREA DURING THE OVERNIGHT HOURS. THIS ALLOWS THE FRONT
TO MOVE BACK SOUTHEAST AS A COLD FRONT...ALLOWING THE COLD AIR TO
INVADE. BUT LOOKING AT THE MODEL SOUNDINGS...THIS COLD AIR ARRIVES
JUST AS THE UPPER LEVEL CLOUD AND SUPPLY OF ICE FOR SEEDING THE
LOW LEVELS MOVES AWAY. IF THE ICE CAN LINGER LONGER...WE MAY SEE A
BIT MORE SNOW ACROSS THE REGION OVERNIGHT. BUT EVEN IF WE DO...IT
LIKELY WILL NOT ADD UP TO MUCH. AND IF THE ICE INDEED DOES
DEPART...SOUNDINGS SUPPORT DRIZZLE TO CONTINUE FOR SEVERAL HOURS.
COULD SOME OF THIS MANIFEST AS FREEZING DRIZZLE? CERTAINLY IT
COULD...WITH THE HIGHEST LIKELIHOOD OVER PARTS OF SOUTHEAST MN
WEST OF ROCHESTER. FURTHER EAST...THE RAIN WILL TAPER OFF AND
BECOME LIGHT...TRANSITIONING TO DRIZZLE AS WELL.
THE ENTIRE SYSTEM EJECTS QUICKLY EASTWARD WEDNESDAY MORNING...SO
THAT BY MID-DAY THE PRECIPITATION SHOULD BE ENDED. SKIES WILL THEN
CLEAR FROM WEST TO EAST ACROSS THE REGION...WITH MAINLY CLEAR
SKIES BY SUNSET. DESPITE THE CLEARING AND RESULTING SUNSHINE...
THE ARRIVAL OF COOLER AIR WILL OFFSET THE WARMING EFFECTS OF THE
SUN...SO NOT MUCH WARMING IS ANTICIPATED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH NEXT TUESDAY)
320 PM CST TUE NOV 5 2013
A LONG WAVE TROUGH OVER THE AREA WILL SHIFT TO THE EAST ON
THURSDAY...WITH SURFACE HIGH PRESSURE BUILDING IN. THERE IS SOME
CONCERN WITH CHANNELED VORTICITY DROPPING INTO THE BACK SIDE OF
THE TROUGH COULD BRING MORE CLOUDINESS OVER WI THURSDAY...WITH THE
OUTSIDE CHANCE OF A SPRINKLE GIVEN THE STEEP LAPSE RATES AND COOL
AIRMASS IN PLACE. BUT THE ATMOSPHERE LOOKS PRETTY MOISTURE STARVED
DURING THAT TIMEFRAME...SO WILL NOT INCLUDE ANY MENTION YET.
THE NEXT SHORT WAVE TROUGH COMES ZIPPING THROUGH THE NORTHERN
CONUS LATE FRIDAY INTO SATURDAY...FLATTENING THE UPPER RIDGE.
MODELS HAVE BEEN STRUGGLING WITH THE LOCATION AND TIMING OF THIS
FEATURE FOR SEVERAL DAYS NOW...AND TODAY NO DIFFERENT. AS THE MAIN
SURFACE LOW CENTER PASSES WELL NORTH OF THE LOCAL AREA...OUR
CHANCE FOR ANY PRECIPITATION WILL COME WITH THE WARM ADVECTION
AHEAD OF THE LEADING WARM FRONT AS IT CROSSES FRIDAY NIGHT INTO
EARLY SATURDAY. THE TRAILING COLD FRONT LOOKS TO MOVE THROUGH
DURING THE DAY ON SATURDAY...BUT WITH NO FORCING ALONG IT...DOES
NOT APPEAR TO BE A THREAT FOR ANY PRECIPITATION.
MODELS REALLY DIVERGE WITH RESPECT TO ENERGY ROTATING AROUND A
CANADIAN TROUGH BY LATE SUNDAY...ALTHOUGH THE LATEST 05.12Z ECMWF
HAS COME MORE INTO LINE WITH THE GFS. DOES NOT APPEAR THERE WILL
BE MUCH OF A PRECIPITATION THREAT...BUT A REINFORCING SHOT OF COOL
AIR LOOKS TO INVADE FOR EARLY NEXT WEEK...POTENTIALLY SENDING
TEMPERATURES ON A DOWNWARD TREND. WAS CONSERVATIVE ON THIS COOLING
TREND AT THIS POINT WITH THE UNCERTAINTY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1138 PM CST TUE NOV 5 2013
SURFACE LOW HAS PROGRESSED RAPIDLY NORTHEAST AND WAS OVER
NORTHEAST IOWA LATE THIS EVENING. THE BULK OF THE RAIN CONTINUES
OUT AHEAD OF THE LOW WITH THE BACK EDGE OF THE MAIN RAIN SHIELD
STARTING TO WORK INTO THE REGION WITH THIS ALREADY COMING THROUGH
KRST. EXPECT TO SEE THE RAIN BECOME MORE SCATTERED THROUGH THE
NIGHT AS THE FORCING CONTINUES TO MOVE OUT WITH THE SURFACE LOW.
BETWEEN 09Z AND 12Z...EXPECT TO SEE THE FORCING REALLY DROP OFF
BUT STILL HAVE SOME OMEGA THROUGH THE SATURATED LOW LEVELS AND
EXPECT THIS TO PRODUCE DRIZZLE. THE 06.00Z NAM AND RAP CONTINUE TO
SUGGEST THE POSSIBILITY OF FREEZING DRIZZLE FOR KRST.
HOWEVER...THESE MODELS HAVE BEEN CONSISENTLY TOO COLD WITH SURFACE
TEMPS THROUGH THE EVENING. IN ADDITION...THE COLDER AIR HAS BEEN
SLOWLY MOVING SOUTH ACROSS MINNESOTA AND CONCERNED THAT IT MAY NOT
ARRIVE BEFORE THE PRECIPITATION ENDS. BASED ON THESE TWO
CONCERNS...CANNOT TOTALLY RULE OUT THE POSSIBILITY OF SOME
FREEZING DRIZZLE AT KRST BUT AT THIS POINT...FEEL THE PROBABILITY
OF THIS OCCURRING IS TOO LOW TO INCLUDE IN THE FORECAST. EXPECT
CEILINGS TO REMAIN IFR UNTIL ABOUT 12Z WHEN SOME DRIER LOW LEVEL
AIR STARTS TO MOVE ALLOWING THESE TO COME UP TO MVFR AND THEN
EVENTUALLY SCATTER OUT BY LATE MORNING TO EARLY AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...MW
LONG TERM...MW
AVIATION...04
AREA FORECAST DISCUSSION
NWS CARIBOU ME
432 AM EST FRI NOV 8 2013
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL THEN SLOWLY BUILD TOWARD THE REGION
FROM THE SOUTHWEST TODAY INTO SATURDAY. LOW PRESSURE FROM CENTRAL
CANADA WILL APPROACH SATURDAY NIGHT AND CROSS THE REGION ON
SUNDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
MAIN CHALLENGES THIS FCST CYCLE WILL BE CLOUDS AND TEMPERATURES.
08Z IR SATL IMAGERY SHOWING CLOUDS FILLING BACK IN ACROSS THE CWA
FROM THE W AS THE UPPER TROF SWINGS ACROSS THE REGION. THIS FEATURE
IS PICKED UP WELL BY THE 00Z NAM/GFS AND THE LATEST RAP AND THE
00Z UA CONFIRMS THIS AS WELL. SOUNDINGS SHOW PLENTY OF MOISTURE
RESIDING FROM 950-700MBS THROUGH THE AFTERNOON WHICH WILL LEAD TO
MOSTLY CLOUDY SKIES. THIS WILL ALSO KEEP TEMPERATURES DOWN THROUGH
THE AFTERNOON AND BELOW NORMAL. THIS WILL MEAN MID/UPPER 30S NORTH
AND WEST W/UPPER 30S TO LOWER 40S CENTRAL AND DOWNEAST. WEAK
FORCING IS NOTED MAINLY ACROSS THE FAR N AND W TODAY LEADING TO
SOME SNOW SHOWERS/FLURRIES. DECIDED ON A BLEND OF THE NAM12 AND
GFS40 FOR THE PRECIP CHANCES WHICH SUPPORT 20-30% IN THE
AFOREMENTIONED AREAS. WNW FLOW ADDING A DOWNSLOPE COMPONENT WILL
KEEP PRECIP CHANCES BELOW THE 15% THRESHOLD FURTHER E AND S.
A SECOND TROF AXIS IS FCST TO MOVE ACROSS THE REGION TONIGHT INTO
SATURDAY. CLOUDS WILL CONTINUE ACROSS THE NORTHERN 1/2 OF THE CWA
W/ANY FLURRIES MAINLY CONFINED TO THE NORTH AND WEST. WNW WINDS WILL STAY
UP OVERNIGHT KEEPING TEMPERATURES UP A BIT. ATTM, DECIDED ON LOWS
TO DROP IN TO MID20S ACROSS NORTH AND WEST AND UPPER 20S CENTRAL
AND DOWNEAST. TROF AXIS WILL BE EAST OF THE CWA BY SATURDAY
MORNING W/SKIES STARTING TO CLEAR. HIGH PRES RIDGE IS FCST TO BRIEFLY
RIDGE ACROSS THE REGION BY THE AFTERNOON W/SUNSHINE AND WNW WINDS
SUBSIDING IN THE AFTERNOON. ANOTHER CHILLY DAY W/AFTERNOON HIGHS
BELOW NORMAL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
A SURFACE RIDGE WILL CREST THE AREA EARLY SATURDAY EVENING AND THEN
MOVE EAST SATURDAY NIGHT. AFTER A MAINLY CLEAR START...CLOUDS WILL
INCREASE LATER SATURDAY NIGHT IN ADVANCE OF WEAK LOW PRESSURE MOVING
INTO QUEBEC PROVINCE. SOME LIGHT SNOW IS EXPECTED TO DEVELOP ACROSS
THE AREA BY EARLY SUNDAY MORNING IN ADVANCE OF THE APPROACHING LOW.
ANOTHER LOW IS THEN EXPECTED TO DEVELOP ALONG THE MID COAST OF MAINE
ALONG THE OCCLUDED FRONT WITH SOME LIGHT PRECIPITATION EXPECTED TO
CONTINUE THROUGH SUNDAY AFTERNOON. THIS SECOND LOW WILL THEN TRACK
QUICKLY EAST INTO NEW BRUNSWICK BY SUNDAY EVENING. ACROSS NORTHERN
AREAS THE PRECIPITATION SHOULD BE MOSTLY IN THE FORM OF SNOW THROUGH
SUNDAY BUT SNOW MAY MIX WITH OR EVEN CHANGE TO ALL RAIN FOR A BIT
ACROSS PORTIONS OF NORTHERN MAINE AS BL TEMPS WARM DURING SUNDAY.
THERE IS THE POTENTIAL FOR ABOUT AN INCH OR SO OF SNOW ACCUMULATION
ACROSS NORTHERN/WESTERN AREAS DURING SUNDAY. ACROSS DOWNEAST
AREAS...THE PRECIPITATION WILL BEGIN AS SOME LIGHT SNOW BUT QUICKLY
CHANGE TO ALL RAIN AS BL TEMPERATURES WARM. THERE COULD BE A DUSTING
TO HALF INCH ACROSS DOWNEAST AREAS BEFORE THE CHANGEOVER.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
SCATTERED SNOW SHOWERS ARE EXPECTED TO PERSIST INTO SUNDAY EVENING
MAINLY ACROSS NORTHERN/WESTERN MAINE BEHIND THE EXITING MARITIMES
LOW.
BRIEF RIDGING IS EXPECTED EARLY MONDAY IN ADVANCE OF THE NEXT COLD
FRONT APPROACHING FROM THE WEST. THIS SYSTEM MAY BRING SCATTERED SNOW
SHOWERS TO THE AREA LATE IN THE DAY MONDAY.
THE COLD FRONT WILL CROSS THE REGION MONDAY NIGHT AND BE ACCOMPANIED
BY SCATTERED SNOW SHOWERS. TEMPERATURES WILL FALL MONDAY NIGHT WITH
THE PASSAGE OF THE FRONT WITH LOW TEMPERATURES BY MONDAY MORNING
EXPECTED TO BE IN THE UPPER TEENS TO NEAR 20 DEGREES NORTH AND
LOW/MID 20S CENTRAL AND DOWNEAST.
TUESDAY WILL BE A BLUSTERY AND COLD DAY WITH TEMPERATURES ACROSS THE
NORTH STRUGGLING TO GET TO THE FREEZING MARK. FAIR AND
UNSEASONABLY COLD WEATHER WILL CONTINUE INTO MID WEEK.
LOW PRESSURE MAY AFFECT THE REGION BY LATE NEXT WEEK PER THE LATEST
ECMWF. HOWEVER...THE LATEST GFS SHOWS HIGH PRESSURE IN CONTROL. SO A
LOT OF UNCERTAINTY STILL EXISTS AT THIS POINT REGARDING THE FORECAST
FOR LATE NEXT WEEK.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR ON TAP THROUGH SATURDAY. A BRIEF PERIOD OF MVFR
CIGS IS POSSIBLE FOR THE NORTHERN TERMINALS THIS AFTERNOON.
SHORT TERM: VFR SATURDAY NIGHT. IFR/MVFR EXPECTED SUNDAY ALL
TERMINALS IN SNOW/RAIN. MVFR IN SCT -SHSN MONDAY NIGHT. VFR/MVFR
DUE TO CIGS...WITH GUSTY NORTHWEST WINDS EXPECTED.
&&
.MARINE...
NEAR TERM: SCA REMAINS IN PLACE THROUGH SATURDAY MORNING. THE LATEST
OBS SHOW WINDS/SEAS BELOW SCA, BUT CONDITIONS ARE EXPECTED TO PICK
BACK UP TO SCA LEVELS AS THE UPPER TROF SWINGS ACROSS THE REGION.
THE SWAN GUIDANCE WAS RUNNING A FOOT TOO HIGH ON ITS WAVES. STAYED
CLOSE TO THE DAYCREW`S ASSESSMENT OF 5 TO 7 FT LATER TONIGHT INTO
TONIGHT. EXPECTATION IS THAT CONDITIONS WILL FALL BELOW SCA BY
EARLY SATURDAY AFTERNOON AS THE SFC RIDGE BUILDS ACROSS THE WATERS.
SHORT TERM: WINDS/SEAS SHOULD BE BELOW SCA LEVELS SATURDAY NIGHT
AND SUNDAY. WINDS/SEAS MAY INCREASE TO SCA LEVELS BY EARLY NEXT
WEEK.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST SATURDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/DUDA
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1214 AM EST FRI NOV 8 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 344 PM EST THU NOV 7 2013
A SURFACE TROUGH IN COMBINATION WITH AN UPPER AIR DISTURBANCE WILL
BRING SHOWERS OF MIXED RAIN AND SNOW TO THE LAKE SHORE AREA...
MOSTLY SOUTH OF MUSKEGON THIS EVENING. THEN HIGH PRESSURE WILL
CLEAR THE SKIES AFTER MIDNIGHT. THE HIGH PRESSURE SYSTEM WILL MOVE
ACROSS SOUTHWEST MICHIGAN FRIDAY PROVIDING SOME SUNSHINE BUT
CHILLY TEMPERATURES.
FRIDAY NIGHT INTO SATURDAY A STORM SYSTEM MOVING EAST ALONG OR
JUST NORTH OF THE CANADIAN BOARDER WILL BRING A FRONTAL SYSTEM
THROUGH THE AREA EARLY SATURDAY MORNING. THAT SYSTEM WILL BRING A
PERIOD OF SHOWERS LATE FRIDAY NIGHT NIGHT INTO SATURDAY.
FINALLY A STRONG COLD FRONT COMES THROUGH THE AREA MONDAY WITH
SHOWERS OF MIXED RAIN AND SNOW.... THEN THE COLDEST AIR OF THE
SEASON MOVES INTO SOUTHWEST MICHIGAN FOR TUESDAY AND WEDNESDAY.
TEMPERATURES WILL STRUGGLE TO GET ABOVE FREEZING EVEN IN THE
AFTERNOON.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 344 PM EST THU NOV 7 2013
THERE ARE TWO ISSUES OF PRIMARY CONCERN FOR THIS FORECAST PERIOD.
FIRST IS THE LAKE EFFECT SHOWERS EXPECTED THIS EVENING... PRIMARILY
SOUTH AND WEST OF GRAND RAPIDS. THEN THERE IS THE PRECIPITATION
WITH THE WARM FRONT FOR THE SYSTEM TRACKING EAST ALONG THE
CANADIAN BORDER SATURDAY INTO SATURDAY NIGHT.
AS SEEN ON BOTH THE WATER VAPOR IMAGE LOOPS...IR AND VISIBLE
SATELLITE IMAGE LOOPS... THERE IS A SERIES OF THREE SHORTWAVES
BETWEEN CHICAGO AND MINNEAPOLIS TRACKING EAST SOUTHEAST. ALREADY
SOME LIGHT SHOWERS ARE SHOWING UP ON RADAR OVER WEST CENTRAL
ALLEGAN COUNTY THEN WEST OVER LAKE MICHIGAN. AS THE NEXT SHORTWAVE
MOVES INTO THE AREA INVERSION HEIGHTS RISE TO 10000 FT AND WITH
850 MB TEMPS NEAR -8C WHILE EASTERN LAKE MICHIGAN WATER
TEMPERATURES ARE STILL NEAR 11C... THAT WILL BE MORE THAN NEEDED
TO RESULT IN LAKE EFFECT SHOWERS FROM NOW THROUGH MIDNIGHT OR SO.
THE BIG QUESTION IS WHAT WILL THE PRECIPITATION TYPE BE? AT THE
START THE AIR IS WARM ENOUGH TO BE RAIN... BUT INLAND OF US-31
AFTER SAY 8 PM OR SO IT MAY JUST BE COLD ENOUGH OF SNOW TO REACH
THE GROUND. GIVEN AIR TEMPS SHOULD REMAIN ABOVE FREEZING I DO NOT
SEE ACCUMULATIONS AMOUNTING TO MORE THAN AN INCH OR SO ON GRASSY
SURFACES BUT THE RAP MODEL DOES GIVE NEARLY .30 OF IN OF QPF OVER
SOUTHERN VAN BUREN COUNTY. MOSTLY BETWEEN 8 PM AND 1 AM. THE WET
BULB ZERO HEIGHTS ARE NEAR 1000 AGL BY THEN SO IT JUST MAY END UP
BEING SNOW. WE WILL HAVE TO WATCH THIS. FOR NOW I HAVE TRACE
AMOUNTS OF SNOW IN THE GRIDS.
ONCE THIS SERIES OF SHORTWAVES MOVES EAST SKIES SHOULD FOR THE
MOST PART CLEAR AND HIGH PRESSURE RULES THROUGH FRIDAY.
THE NEXT SYSTEM TRACKS NORTH OF THE CANADIAN BOARDER NEAR LAKE
SUPERIOR FRIDAY NIGHT INTO SATURDAY. THE ISENTROPIC LIFT AHEAD OF
THE WARM FRONT WILL BRING SHOWERS TO THE AREA EARLY SATURDAY
MORNING BUT THE BEST LIFT AND MOISTURE IS NORTH OF I-96 SO THAT IS
WHERE THE HIGHEST POPS ARE. IT SHOULD BE WARM ENOUGH TO BE MOSTLY
RAIN.
THAT WRAPS IN WARMER AIR FOR SATURDAY SO LAKE EFFECT IS OUT OF
PLAY THUS EXPECT PARTLY CLOUDY SKIES FOR THE MOST PART AS SLIGHTLY
WARMER TEMPERATURES.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 344 PM EST THU NOV 7 2013
COLD IS THE OPERATIVE WORD IN THE EXTENDED WITH A BIG ARCTIC HIGH
BRINGING BELOW NORMAL TEMPERATURES FROM TUESDAY THROUGH THURSDAY. NO
BIG STORMS IN THE OFFING BUT SHOWERS OF RAIN MIXED WITH SNOW ARE
EXPECTED MONDAY AND INTO MONDAY NIGHT ALONG THE ARCTIC FRONT.
LAKE EFFECT SNOW BEHIND THE FRONT SHOULD BE LIMITED TO FAR WESTERN
ZONES AS FLOW IS EXPECTED TO BE NORTHERLY AND MAY EVEN GO OFFSHORE
BY TUESDAY NIGHT. THE 12Z GUIDANCE HAS SHIFTED WEST WITH THE PATH OF
THE ANTICYCLONE...BUT THE EURO STILL INDICATES LESS IN THE WAY OF
ONSHORE FLOW THROUGH THURSDAY MORNING AS SFC RIDGING REMAINS STRONG
OVER LOWER MICHIGAN. THIS WOULD MEAN LESS CLOUDS AND COLDER MIN
TEMPS ACROSS THE WESTERN FORECAST AREA THAN THE GFS. MIN TEMPS WERE
LOWERED THURSDAY MORNING TO ACCOUNT FOR THIS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1213 AM EST FRI NOV 8 2013
MVFR/IFR CIGS AND VSBYS MAY LINGER FOR A FEW MORE HOURS /09Z OR SO/
AT BTL AND AZO BEFORE THE LAKE EFFECT SNOW AND RAIN SHOWERS
COMPLETELY END. OTHERWISE VFR CONDITIONS WILL PREVAIL LATE TONIGHT
AND FRIDAY.
&&
.MARINE...
ISSUED AT 344 PM EST THU NOV 7 2013
I CONTINUED THE SMALL CRAFT ADVISORY THROUGH TONIGHT AND ISSUED A
GALE WARNING FOR FRIDAY NIGHT DUE TO THE STRONG SOUTHERLY FLOW
OVER LAKE MICHIGAN AHEAD OF THE SYSTEM. LAKE TEMPS OVER THE
EASTERN PART OF LAKE MICHIGAN ARE IN THE LOWER 50S BUT THE
SOUTHERLY WINDS WILL BE BRINGING SURFACE AIR ONLY IN THE 40S OVER
THAT LAKE SO THAT SHOULD BE ENOUGH TO ALLOW ENOUGH MIXING TO BRING
THE 40 TO 50 KNOT WINDS IN THE BOUNDARY LAYER DOWN CLOSE TO THE
LAKE SURFACE. THUS THE GALE WATCH FRIDAY NIGHT.
&&
.HYDROLOGY...
ISSUED AT 344 PM EST THU NOV 7 2013
EVEN WITH THE .5 TO 1.5 INCHES OF RAIN THAT FELL WEDNESDAY THE
RIVERS DID NOT RESPOND MUCH. SO WITH LITTLE IN THE WAY OF
SIGNIFICANT QPF EXPECTED OVER THE NEXT WEEK... I SEE NO SIGNIFICANT
ISSUES WITH AREA RIVERS AND STREAMS ON THE SHORT TERM.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WATCH FROM THIS EVENING THROUGH SATURDAY MORNING FOR
LMZ844>849.
SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...OSTUNO
AVIATION...MEADE
HYDROLOGY...WDM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
250 AM EST FRI NOV 08 2013
.SYNOPSIS...
HIGH PRESSURE BUILDS OVER THE AREA TODAY AND REMAINS IN PLACE
THROUGH MUCH OF THE WEEKEND. A DRY COLD FRONT MOVES THROUGH THE
REGION SUNDAY. ANOTHER HIGH THEN BUILDS OVER THE REGION FOR MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM FRIDAY...
WATER VAPOR IMAGERY SHOWS THE TROUGH AXIS ALOFT MOVING EAST...AND
BOTH THE NAM AND THE GFS SUGGEST THE SOUTHERN END OF THIS AXIS WILL
PUSH THROUGH CENTRAL NORTH CAROLINA THROUGH MIDDAY. THE AIR MASS IS
FAIRLY DRY ALOFT...AND BUFR SOUNDINGS FROM BOTH THE NAM AND THE GFS
SHOW A DRY AIR MASS VIRTUALLY THROUGHOUT THE COLUMN THROUGH
TONIGHT...WITH PRECIPITABLE WATER VALUES BELOW NORMAL...AT OR BELOW
A QUARTER-INCH. LOW AMPLITUDE RIDGING ALOFT MOVES IN LATE TONIGHT...
BUT DESPITE THE WESTERLY FLOW ALOFT...THE GENERAL CONFLUENCE OF THAT
FLOW SHOULD KEEP MUCH IF NOT ALL OF THE HIGH CLOUDS OVER THE
SOUTHERN PLAINS TO THE WEST OF THE AREA...WITH MAYBE A FEW CIRRUS
EEKING INTO THE AREA. PATCH OF LOWER CLOUDS OVER PARTS OF HALIFAX
AND EDGECOMBE COUNTIES FINALLY DRIFTING SOUTHEAST IN CONCERT WITH
THE RAP MODEL SOUNDINGS...WHICH SHOW THE LOW-LEVEL MOISTURE
DIMINISHING IN THAT AREA THROUGH 10Z. UNDER SUBSIDENCE...NEGATIVE K
INDEX VALUES...AND AN 850MB THETA-E TROUGH...ANTICIPATE CONSIDERABLE
SUNSHINE TODAY AND CLEAR OR MOSTLY CLEAR CONDITIONS TONIGHT.
AREA VAD WIND PROFILES FROM THE WSR-88DS SHOWED WINDS NOT FAR OFF
THE SURFACE TO AROUND 40KT FROM THE NORTH...BUT THESE WINDS SHOULD
DIMINISH AS THE GFS FORECASTS 925MB WINDS FALLING TO NEAR 30KT VERY
EARLY TODAY AND THEN QUICKLY BELOW 20KT BY 18Z. EXPECT A FEW WIND
GUSTS NEAR 20KT DURING THE DAY BASED ON MIXING AVAILABLE VIA BUFR
SOUNDINGS. MET AND MAV MOS GUIDANCE VALUES ARE VERY CLOSE AND
GENERALLY FOLLOWED...AND THE HIGHS ARE IN FAIR AGREEMENT WITH
EXPECTED 1000-850MB THICKNESSES. HIGHS TODAY 55 TO 60. LOWS TONIGHT
WILL BE MORE VARIABLE UNDER A LIGHT WIND...MOSTLY AROUND 30 BUT SOME
MID TO UPPER 20S POSSIBLE IN THE TYPICALLY COOLER AREAS...AND A FEW
MID 30S SOUTHEAST.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 230 AM FRIDAY...
THE LOW AMPLITUDE RIDGE PROGRESSES ACROSS CENTRAL NORTH CAROLINA
SATURDAY...WITH WEAK UPPER-LEVEL TROUGHING MOVING INTO CENTRAL NORTH
CAROLINA SATURDAY NIGHT. THE MAIN DIFFERENCE BETWEEN THE NAM AND THE
GFS IS THE AMOUNT OF UPPER-LEVEL MOISTURE AND THE STRENGTH OF THE
MID-LEVEL SHORTWAVES IN THE WESTERLY FLOW ALOFT. THE GFS IS
NOTICEABLY MORE MOIST IN THE HIGH-CLOUD PORTION OF THE AIR MASS WITH
STRONGER SHORTWAVES...WHILE THE NAM IS DRIER AND WEAKER...
RESPECTIVELY. THE GFS WOULD PORTEND A GOOD INCREASE OF CIRRUS LATE
SATURDAY AND SATURDAY NIGHT ESPECIALLY ALONG AND SOUTH OF U.S. 64...
WHILE THE NAM WOULD NOTE MUCH LESS OR THINNER SUCH CLOUDS. THE
CANADIAN CLOUD COVER MODEL...USUALLY GOOD WITH HIGH-LEVEL CLOUDS...
IS MORE AKIN TO THE NAM...AND FOR THIS FORECAST WILL HAVE SKIES
PARTLY CLOUDY AT WORST LATE SATURDAY AFTERNOON AND SATURDAY NIGHT...
WITH THE HIGHER QUANTITY OF CLOUDS OVER THE SOUTHERN TWO TIERS OF
COUNTIES RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA. 1000-850MB
THICKNESSES WARM DURING THE DAY SATURDAY...AND THE SURFACE WIND
VEERS SOUTHWEST. WITH A DRY AIR MASS...THE GUIDANCE FORECAST OF A
NEARLY 30-DEGREE DIURNAL SEEMS POSSIBLE...FOR HIGHS AROUND 60.
OVERNIGHT LOWS SATURDAY NIGHT ARE A LITTLE MORE TRICKY DEPENDING ON
HOW MUCH WIND EXISTS...AS WINDS OFF OF THE SURFACE INCREASE AHEAD OF
THE NEXT DRY SURFACE FRONT. BASED ON THE POTENTIAL FOR A LITTLE
STIRRING AND THE GUIDANCE TENDENCY TO BE COOL IN THE NIGHT AHEAD OF
A SURFACE BOUNDARY...WILL SHOW A DEFINITE LEAN TOWARD THE WARMER MAV
MOS SATURDAY NIGHT. LOWS WITHIN TWO OR THREE DEGREES EITHER SIDE OF
40.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...
FOR SUNDAY THROUGH MONDAY NIGHT: QUIET AND DRY BUT TURNING COOLER.
EXPECT A FEW MID AND HIGH CLOUDS OVER THE REGION SUNDAY MORNING...
MOST MARKEDLY OVER SRN NC AS MID/HIGH CLOUDS NOW OVER NRN MEX INTO
TX SWEEP EASTWARD ACROSS THE GULF AND SOUTHEAST STATES. THE MID
LEVEL SHORTWAVE TROUGH NOW OVER MT/WY WILL DRAW IN ADDITIONAL ENERGY
FROM THE YUKON AS IT TRACKS QUICKLY EASTWARD ACROSS THE GREAT
LAKES/NORTHEAST INTO SUNDAY...SWEEPING A WEAK DRY COOL FRONT THROUGH
THE MIDATLANTIC REGION. THIS MID LEVEL TROUGH SWEEPING BY JUST TO
OUR NORTH SHOULD BRING A FEW HIGH CLOUDS ACROSS THE VA BORDER
SECTIONS...WHICH COULD BE OROGRAPHICALLY ENHANCED EARLY SUNDAY AS
SUGGESTED BY FORECAST SOUNDINGS. NEVERTHELESS...WE SHOULD SEE PLENTY
OF SUNSHINE FOR MUCH OF SUNDAY AS A GENERALLY DRY AND STABLE COLUMN
PERSISTS WITH A DOWNSLOPE WNW LOW LEVEL FLOW. 1000-850 MB
THICKNESSES ARE EXPECTED TO BE SLIGHTLY ABOVE NORMAL AHEAD OF THE
WEAK FRONT...SUPPORTING HIGHS SUNDAY OF 64-69. THE FRONT SHOULD PUSH
THROUGH THE AREA SUNDAY EVENING WITH THE COOLER SURFACE HIGH
STARTING TO BUILD IN FROM THE WEST. THE MSLP PATTERN INDICATES THAT
SURFACE WINDS SHOULD STAY UP ENOUGH IN THE EAST TO CURB RADIATIONAL
COOLING SUNDAY NIGHT...BUT WESTERN SECTIONS CLOSER TO THE HIGH
CENTER SHOULD GO NEARLY CALM. LOWS 32-40. MOSTLY SUNNY/DRY/COOL
MONDAY WITH THE SURFACE HIGH PASSING QUICKLY WEST-TO-EAST OVER NC...
AHEAD OF THE NEXT FRONT. SHOULD SEE AN INCREASE IN HIGH CLOUDS
MONDAY NIGHT WITH STRENGTHENING MID LEVEL FLOW OVER NC IN RESPONSE
TO THE STRONG VORTEX CROSSING SRN ONTARIO/QUEBEC. TEMPS A BIT BELOW
NORMAL MONDAY...HIGHS 60-65 AND LOWS 37-42.
FOR TUESDAY THROUGH THURSDAY: STILL ANTICIPATING A BREAK IN THE
QUIET WEATHER...AS A DEEP MID LEVEL SHORTWAVE TROUGH AND
ACCOMPANYING POLAR SURFACE FRONT DROP SSE TOWARD NC. SURPRISINGLY...
AGREEMENT AMONG THE MODELS IS ACTUALLY WORSE THAN IT WAS WITH
YESTERDAY`S RUNS. THE 00Z/08 GFS OVER THE LAST 4 RUNS HAS TRENDED
LESS AMPLIFIED...MORE PHASED...DRIER...AND MUCH MORE PROGRESSIVE
WITH THE MID LEVEL TROUGH SWINGING THROUGH THE EASTERN HALF OF THE
CONUS...AND IT LACKS A CLOSED LOW IN FAVOR OF A MOISTURE-STARVED MID
LEVEL TROUGH PASSAGE. THE ECMWF HAS BEEN QUITE CONSISTENT IN ITS
LAST 4 RUNS IN CLOSING OFF AN INTENSE VORTEX OVER KY/TN/SRN
APPALACHIANS LATE WED/WED NIGHT WHICH WOBBLES EASTWARD BEFORE
LIFTING OUT LATE THU... A SCENARIO ALSO HINTED AT BY THE LATEST GEFS
RUNS. THE 00Z/08 ECMWF GENERATES ABUNDANT FORCING FOR ASCENT OVER NC
AND OFF OUR COAST...FOSTERING DEVELOPMENT OF AN EXPLOSIVE COASTAL
LOW ALONG THE NEARSHORE BAROCLINIC ZONE...WHICH IN TURN SPREADS A
LOT OF WRAPAROUND PRECIP OVER THE INLAND SOUTHEAST AND MIDATLANTIC
LATE TUE NIGHT THROUGH WED EVENING. WHILE THE ECMWF HAS HAD LITTLE
SUPPORT FROM ITS ENSEMBLE MEAN...IT WOULD BE FOOLHARDY TO TOTALLY
DISCOUNT IT...BASED ON BOTH ITS CONSISTENCY AND ITS HISTORICAL
PERFORMANCE. BUT GIVEN THAT THIS IS A HIGHLY ANOMALOUS AND
CLIMATOLOGICALLY UNUSUAL SOLUTION...WILL CONTINUE WITH A
MIDDLE-OF-THE-ROAD APPROACH TO THIS EVENT...HOLDING CLOSER TO
CLIMATOLOGY THAN TO ANY EXTREME...BUT CERTAINLY THIS POSSIBLE STORM
BEARS WATCHING. APART FROM THE MODEL DIFFERENCES WITH QPF AMOUNT AND
PLACEMENT...THERE IS LITTLE DOUBT THAT THE INCOMING AIR MASS BEHIND
THE FRONT WILL BE QUITE COLD...WITH PROJECTED LOW LEVEL THICKNESSES
DROPPING TOWARD 1280 M...NEARLY 60 M BELOW NORMAL...AND BOTH THE GFS
AND ECMWF TAKING 850 MB TEMPS DOWN TO -7C TO -10C. CURRENT TEMPS
WITHIN THIS AIR MASS (NOW OVER NRN YUKON/NRN NW TERRITORIES AND THE
BEAUFORT SEA) ARE WELL BELOW ZERO FAHRENHEIT...AND THIS AIR MASS
WILL HAVE LIMITED TIME TO MODIFY BEFORE IT ARRIVES. PARTIAL
THICKNESSES FROM THE OPERATIONAL GFS AND ECMWF STILL SUGGEST A
POTENTIAL FOR WINTRY PRECIP...HOWEVER THE OPTIMAL PATTERN FOR A LOT
OF COLD AIR IN NC AND THE OPTIMAL PATTERN TO GET SUFFICIENT MOISTURE
INTO NC ARE USUALLY VERY DIFFERENT. WITH THE OPERATIONAL MODEL
SOLUTIONS SO DIVERGENT...WE CANNOT AT THIS TIME STATE A PREFERRED
SCENARIO WITH ANY CONFIDENCE. WILL STAY WITH CHANCE POPS EARLY WED
MORNING INTO THU AND WILL KEEP ANY PRECIP AS JUST COLD RAIN FOR
NOW...BUT WE WILL CLOSELY MONITOR MODEL AND OBSERVED TRENDS OVER THE
NEXT SEVERAL DAYS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1240 AM FRIDAY...
VFR CONDITIONS WILL CONTINUE THROUGH THE 06Z VALID TAF PERIOD. A FEW
LOWER CLOUDS...STILL VFR...JUST EAST OF KRWI EARLY THIS MORNING
SHOULD STAY JUST EAST OF THAT TERMINAL...WITH THE RAP MODEL SHOWING
THE RELATIVE LOW-LEVEL MOISTURE GRADUALLY DIMINISHING THROUGH 12Z.
INCLUDED LLWS FOR A PERIOD EARLY THIS MORNING AT KGSO...KINT..AND
KRDU WHERE THE COMBINATION OF A GENERALLY DIMINISHING SURFACE
WIND...AND WSR-88D DATA WITH SLIGHTLY VEERING WINDS TO 40KT WITHIN
THE FIRST 2000FT...SUGGEST ITS OCCURRENCE. WINDS AT THE 2K FT LEVEL
SHOULD DIMINISH BY 12Z BASED ON BOTH THE NAM AND GFS MODEL
SOUNDINGS. FOR THE DAYLIGHT HOURS...A NORTHWEST WIND SHOULD CONTINUE
WITH A FEW SURFACE GUSTS APPROACHING 20KT WITH MIXING. WINDS
DIMINISH QUICKLY WITH SUNSET...FALLING AOB 5KT...POSSIBLY VEERING
SLIGHTLY MORE NORTH.
BEYOND THE 06Z VALID TAF PERIOD...VFR CONDITIONS SHOULD PREVAIL FOR
MUCH OF THE DEFINED PERIOD THROUGH TUESDAY. SURFACE WINDS BECOME
SOUTHWEST SATURDAY...THEN VEER MOSTLY WESTERLY SUNDAY. BEHIND A DRY
SURFACE FRONT...WINDS MAY VEER QUICKLY AROUND THE CLOCK MONDAY INTO
TUESDAY BEFORE BECOMING NORTHEAST AND POSSIBLY MODESTLY GUSTY
TUESDAY. DEPENDING ON THE MOISTURE AVAILABLE WITH A POSSIBLE SYSTEM
LATE IN THIS PERIOD...THERE IS THE POTENTIAL FOR SUB-VFR CLOUD
HEIGHTS...CURRENTLY A HIGHER PROBABILITY OF MVFR.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...HARTFIELD
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
230 AM EST FRI NOV 08 2013
.SYNOPSIS...
HIGH PRESSURE BUILDS OVER THE AREA TODAY AND REMAINS IN PLACE
THROUGH MUCH OF THE WEEKEND. A DRY COLD FRONT MOVES THROUGH THE
REGION SUNDAY. ANOTHER HIGH THEN BUILDS OVER THE REGION FOR MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM FRIDAY...
WATER VAPOR IMAGERY SHOWS THE TROUGH AXIS ALOFT MOVING EAST...AND
BOTH THE NAM AND THE GFS SUGGEST THE SOUTHERN END OF THIS AXIS WILL
PUSH THROUGH CENTRAL NORTH CAROLINA THROUGH MIDDAY. THE AIR MASS IS
FAIRLY DRY ALOFT...AND BUFR SOUNDINGS FROM BOTH THE NAM AND THE GFS
SHOW A DRY AIR MASS VIRTUALLY THROUGHOUT THE COLUMN THROUGH
TONIGHT...WITH PRECIPITABLE WATER VALUES BELOW NORMAL...AT OR BELOW
A QUARTER-INCH. LOW AMPLITUDE RIDGING ALOFT MOVES IN LATE TONIGHT...
BUT DESPITE THE WESTERLY FLOW ALOFT...THE GENERAL CONFLUENCE OF THAT
FLOW SHOULD KEEP MUCH IF NOT ALL OF THE HIGH CLOUDS OVER THE
SOUTHERN PLAINS TO THE WEST OF THE AREA...WITH MAYBE A FEW CIRRUS
EEKING INTO THE AREA. PATCH OF LOWER CLOUDS OVER PARTS OF HALIFAX
AND EDGECOMBE COUNTIES FINALLY DRIFTING SOUTHEAST IN CONCERT WITH
THE RAP MODEL SOUNDINGS...WHICH SHOW THE LOW-LEVEL MOISTURE
DIMINISHING IN THAT AREA THROUGH 10Z. UNDER SUBSIDENCE...NEGATIVE K
INDEX VALUES...AND AN 850MB THETA-E TROUGH...ANTICIPATE CONSIDERABLE
SUNSHINE TODAY AND CLEAR OR MOSTLY CLEAR CONDITIONS TONIGHT.
AREA VAD WIND PROFILES FROM THE WSR-88DS SHOWED WINDS NOT FAR OFF
THE SURFACE TO AROUND 40KT FROM THE NORTH...BUT THESE WINDS SHOULD
DIMINISH AS THE GFS FORECASTS 925MB WINDS FALLING TO NEAR 30KT VERY
EARLY TODAY AND THEN QUICKLY BELOW 20KT BY 18Z. EXPECT A FEW WIND
GUSTS NEAR 20KT DURING THE DAY BASED ON MIXING AVAILABLE VIA BUFR
SOUNDINGS. MET AND MAV MOS GUIDANCE VALUES ARE VERY CLOSE AND
GENERALLY FOLLOWED...AND THE HIGHS ARE IN FAIR AGREEMENT WITH
EXPECTED 1000-850MB THICKNESSES. HIGHS TODAY 55 TO 60. LOWS TONIGHT
WILL BE MORE VARIABLE UNDER A LIGHT WIND...MOSTLY AROUND 30 BUT SOME
MID TO UPPER 20S POSSIBLE IN THE TYPICALLY COOLER AREAS...AND A FEW
MID 30S SOUTHEAST.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 230 AM FRIDAY...
THE LOW AMPLITUDE RIDGE PROGRESSES ACROSS CENTRAL NORTH CAROLINA
SATURDAY...WITH WEAK UPPER-LEVEL TROUGHING MOVING INTO CENTRAL NORTH
CAROLINA SATURDAY NIGHT. THE MAIN DIFFERENCE BETWEEN THE NAM AND THE
GFS IS THE AMOUNT OF UPPER-LEVEL MOISTURE AND THE STRENGTH OF THE
MID-LEVEL SHORTWAVES IN THE WESTERLY FLOW ALOFT. THE GFS IS
NOTICEABLY MORE MOIST IN THE HIGH-CLOUD PORTION OF THE AIR MASS WITH
STRONGER SHORTWAVES...WHILE THE NAM IS DRIER AND WEAKER...
RESPECTIVELY. THE GFS WOULD PORTEND A GOOD INCREASE OF CIRRUS LATE
SATURDAY AND SATURDAY NIGHT ESPECIALLY ALONG AND SOUTH OF U.S. 64...
WHILE THE NAM WOULD NOTE MUCH LESS OR THINNER SUCH CLOUDS. THE
CANADIAN CLOUD COVER MODEL...USUALLY GOOD WITH HIGH-LEVEL CLOUDS...
IS MORE AKIN TO THE NAM...AND FOR THIS FORECAST WILL HAVE SKIES
PARTLY CLOUDY AT WORST LATE SATURDAY AFTERNOON AND SATURDAY NIGHT...
WITH THE HIGHER QUANTITY OF CLOUDS OVER THE SOUTHERN TWO TIERS OF
COUNTIES RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA. 1000-850MB
THICKNESSES WARM DURING THE DAY SATURDAY...AND THE SURFACE WIND
VEERS SOUTHWEST. WITH A DRY AIR MASS...THE GUIDANCE FORECAST OF A
NEARLY 30-DEGREE DIURNAL SEEMS POSSIBLE...FOR HIGHS AROUND 60.
OVERNIGHT LOWS SATURDAY NIGHT ARE A LITTLE MORE TRICKY DEPENDING ON
HOW MUCH WIND EXISTS...AS WINDS OFF OF THE SURFACE INCREASE AHEAD OF
THE NEXT DRY SURFACE FRONT. BASED ON THE POTENTIAL FOR A LITTLE
STIRRING AND THE GUIDANCE TENDENCY TO BE COOL IN THE NIGHT AHEAD OF
A SURFACE BOUNDARY...WILL SHOW A DEFINITE LEAN TOWARD THE WARMER MAV
MOS SATURDAY NIGHT. LOWS WITHIN TWO OR THREE DEGREES EITHER SIDE OF
40.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...
FOR SUNDAY THROUGH MONDAY NIGHT: QUIET AND DRY BUT TURNING COOLER.
EXPECT A FEW MID AND HIGH CLOUDS OVER THE REGION SUNDAY MORNING...
MOST MARKEDLY OVER SRN NC AS MID/HIGH CLOUDS NOW OVER NRN MEX INTO
TX SWEEP EASTWARD ACROSS THE GULF AND SOUTHEAST STATES. THE MID
LEVEL SHORTWAVE TROUGH NOW OVER MT/WY WILL DRAW IN ADDITIONAL ENERGY
FROM THE YUKON AS IT TRACKS QUICKLY EASTWARD ACROSS THE GREAT
LAKES/NORTHEAST INTO SUNDAY...SWEEPING A WEAK DRY COOL FRONT THROUGH
THE MIDATLANTIC REGION. THIS MID LEVEL TROUGH SWEEPING BY JUST TO
OUR NORTH SHOULD BRING A FEW HIGH CLOUDS ACROSS THE VA BORDER
SECTIONS...WHICH COULD BE OROGRAPHICALLY ENHANCED EARLY SUNDAY AS
SUGGESTED BY FORECAST SOUNDINGS. NEVERTHELESS...WE SHOULD SEE PLENTY
OF SUNSHINE FOR MUCH OF SUNDAY AS A GENERALLY DRY AND STABLE COLUMN
PERSISTS WITH A DOWNSLOPE WNW LOW LEVEL FLOW. 1000-850 MB
THICKNESSES ARE EXPECTED TO BE SLIGHTLY ABOVE NORMAL AHEAD OF THE
WEAK FRONT...SUPPORTING HIGHS SUNDAY OF 64-69. THE FRONT SHOULD PUSH
THROUGH THE AREA SUNDAY EVENING WITH THE COOLER SURFACE HIGH
STARTING TO BUILD IN FROM THE WEST. THE MSLP PATTERN INDICATES THAT
SURFACE WINDS SHOULD STAY UP ENOUGH IN THE EAST TO CURB RADIATIONAL
COOLING SUNDAY NIGHT...BUT WESTERN SECTIONS CLOSER TO THE HIGH
CENTER SHOULD GO NEARLY CALM. LOWS 32-40. MOSTLY SUNNY/DRY/COOL
MONDAY WITH THE SURFACE HIGH PASSING QUICKLY WEST-TO-EAST OVER NC...
AHEAD OF THE NEXT FRONT. SHOULD SEE AN INCREASE IN HIGH CLOUDS
MONDAY NIGHT WITH STRENGTHENING MID LEVEL FLOW OVER NC IN RESPONSE
TO THE STRONG VORTEX CROSSING SRN ONTARIO/QUEBEC. TEMPS A BIT BELOW
NORMAL MONDAY...HIGHS 60-65 AND LOWS 37-42.
FOR TUESDAY THROUGH THURSDAY: STILL ANTICIPATING A BREAK IN THE
QUIET WEATHER...AS A DEEP MID LEVEL SHORTWAVE TROUGH AND
ACCOMPANYING POLAR SURFACE FRONT DROP SSE TOWARD NC. SURPRISINGLY...
AGREEMENT AMONG THE MODELS IS ACTUALLY WORSE THAN IT WAS WITH
YESTERDAY`S RUNS. THE 00Z/08 GFS OVER THE LAST 4 RUNS HAS TRENDED
LESS AMPLIFIED...MORE PHASED...DRIER...AND MUCH MORE PROGRESSIVE
WITH THE MID LEVEL TROUGH SWINGING THROUGH THE EASTERN HALF OF THE
CONUS...AND IT LACKS A CLOSED LOW IN FAVOR OF A MOISTURE-STARVED MID
LEVEL TROUGH PASSAGE. THE ECMWF HAS BEEN QUITE CONSISTENT IN ITS
LAST 4 RUNS IN CLOSING OFF AN INTENSE VORTEX OVER KY/TN/SRN
APPALACHIANS LATE WED/WED NIGHT WHICH WOBBLES EASTWARD BEFORE
LIFTING OUT LATE THU. THE 00Z/08 ECMWF GENERATES ABUNDANT FORCING
FOR ASCENT OVER NC AND OFF OUR COAST...FOSTERING DEVELOPMENT OF AN
EXPLOSIVE COASTAL LOW ALONG THE NEARSHORE BAROCLINIC ZONE...WHICH IN
TURN SPREADS A LOT OF WRAPAROUND PRECIP OVER THE INLAND SOUTHEAST
AND MIDATLANTIC LATE TUE NIGHT THROUGH WED EVENING. WHILE THE ECMWF
HAS HAD LITTLE SUPPORT FROM ITS ENSEMBLE MEAN...IT WOULD BE
FOOLHARDY TO TOTALLY DISCOUNT IT...BASED ON BOTH ITS CONSISTENCY AND
ITS HISTORICAL PERFORMANCE. BUT GIVEN THAT THIS IS A HIGHLY
ANOMALOUS AND CLIMATOLOGICALLY UNUSUAL SOLUTION...WILL CONTINUE WITH
A MIDDLE-OF-THE-ROAD APPROACH TO THIS EVENT...HOLDING CLOSER TO
CLIMATOLOGY THAN TO ANY EXTREME...BUT CERTAINLY THIS POSSIBLE STORM
BEARS WATCHING. APART FROM THE MODEL DIFFERENCES WITH QPF AMOUNT AND
PLACEMENT...THERE IS LITTLE DOUBT THAT THE INCOMING AIR MASS BEHIND
THE FRONT WILL BE QUITE COLD...WITH PROJECTED LOW LEVEL THICKNESSES
DROPPING TOWARD 1280 M...NEARLY 60 M BELOW NORMAL...AND BOTH THE GFS
AND ECMWF TAKING 850 MB TEMPS DOWN TO -7C TO -10C. CURRENT TEMPS
WITHIN THIS AIR MASS (NOW OVER NRN YUKON/NRN NW TERRITORIES AND THE
BEAUFORT SEA) ARE WELL BELOW ZERO FAHRENHEIT...AND THIS AIR MASS
WILL HAVE LIMITED TIME TO MODIFY BEFORE IT ARRIVES. PARTIAL
THICKNESSES FROM THE OPERATIONAL GFS AND ECMWF STILL SUGGEST A
POTENTIAL FOR WINTRY PRECIP...HOWEVER THE OPTIMAL PATTERN FOR A LOT
OF COLD AIR IN NC AND THE OPTIMAL PATTERN TO GET SUFFICIENT MOISTURE
INTO NC ARE USUALLY VERY DIFFERENT. WITH THE OPERATIONAL MODEL
SOLUTIONS SO DIVERGENT...WE CANNOT AT THIS TIME STATE A PREFERRED
SCENARIO WITH ANY CONFIDENCE. WILL STAY WITH CHANCE POPS EARLY WED
MORNING INTO THU AND WILL KEEP ANY PRECIP AS JUST COLD RAIN FOR
NOW...BUT WE WILL CLOSELY MONITOR MODEL AND OBSERVED TRENDS OVER THE
NEXT SEVERAL DAYS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1240 AM FRIDAY...
VFR CONDITIONS WILL CONTINUE THROUGH THE 06Z VALID TAF PERIOD. A FEW
LOWER CLOUDS...STILL VFR...JUST EAST OF KRWI EARLY THIS MORNING
SHOULD STAY JUST EAST OF THAT TERMINAL...WITH THE RAP MODEL SHOWING
THE RELATIVE LOW-LEVEL MOISTURE GRADUALLY DIMINISHING THROUGH 12Z.
INCLUDED LLWS FOR A PERIOD EARLY THIS MORNING AT KGSO...KINT..AND
KRDU WHERE THE COMBINATION OF A GENERALLY DIMINISHING SURFACE
WIND...AND WSR-88D DATA WITH SLIGHTLY VEERING WINDS TO 40KT WITHIN
THE FIRST 2000FT...SUGGEST ITS OCCURRENCE. WINDS AT THE 2K FT LEVEL
SHOULD DIMINISH BY 12Z BASED ON BOTH THE NAM AND GFS MODEL
SOUNDINGS. FOR THE DAYLIGHT HOURS...A NORTHWEST WIND SHOULD CONTINUE
WITH A FEW SURFACE GUSTS APPROACHING 20KT WITH MIXING. WINDS
DIMINISH QUICKLY WITH SUNSET...FALLING AOB 5KT...POSSIBLY VEERING
SLIGHTLY MORE NORTH.
BEYOND THE 06Z VALID TAF PERIOD...VFR CONDITIONS SHOULD PREVAIL FOR
MUCH OF THE DEFINED PERIOD THROUGH TUESDAY. SURFACE WINDS BECOME
SOUTHWEST SATURDAY...THEN VEER MOSTLY WESTERLY SUNDAY. BEHIND A DRY
SURFACE FRONT...WINDS MAY VEER QUICKLY AROUND THE CLOCK MONDAY INTO
TUESDAY BEFORE BECOMING NORTHEAST AND POSSIBLY MODESTLY GUSTY
TUESDAY. DEPENDING ON THE MOISTURE AVAILABLE WITH A POSSIBLE SYSTEM
LATE IN THIS PERIOD...THERE IS THE POTENTIAL FOR SUB-VFR CLOUD
HEIGHTS...CURRENTLY A HIGHER PROBABILITY OF MVFR.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...GIH
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1240 AM EST FRI NOV 08 2013
.SYNOPSIS...
HIGH PRESSURE BUILDS OVER THE AREA TODAY AND REMAINS IN PLACE
THROUGH MUCH OF THE WEEKEND. A DRY COLD FRONT MOVES THROUGH THE
REGION SUNDAY. ANOTHER HIGH THEN BUILDS OVER THE REGION FOR MONDAY.
&&
.NEAR TERM /TONIGHT/...
AS OF 850 PM THURSDAY...
THE SURFACE COLD FRONT HAS MOVED TO THE EAST OF THE AREA THIS
EVENING... WITH SURFACE HIGH PRESSURE NOW BUILDING INTO THE REGION
FROM THE WEST. GOOD CAA BEHIND THE FRONT AND ONLY A FEW HIGH THIN
CIRRUS POSSIBLE WILL LEAD TO LOWS FRIDAY MORNING IN THE MID TO UPPER
30S TO AROUND 40 IN OUR FAR EAST AND SOUTHEAST. EXPECT WE WILL
MAINTAIN AT LEAST A LIGHT NORTHERLY TO NORTHWESTERLY BREEZE
OVERNIGHT AFTER THE GUSTINESS BEHIND THE FRONT BEGINS TO DIE DOWN
WITH THE LOSS OF DEEPER MIXING.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 215 PM THURSDAY...
THE UPPER LEVEL FLOW FLATTENS OUT ACROSS MUCH OF THE CONUS
ON FRIDAY WITH A STRONG ~1030MB CP SURFACE HIGH OVER THE TN/MS
VALLEY SETTLING OVER CENTRAL NC FRIDAY NIGHT. LOW-LEVEL THICKNESSES
TO START THE DAY ARE PROGGED TO BE AROUND 1310M...REPRESENTATIVE
OF LATE DECEMBER/EARLY JANUARY. FCST SOUNDINGS AND IN-HOUSE THICKNESS
SCHEME SUPPORT FORECAST HIGHS A GOOD 3 DEGREES COOLER THAN MOS
STATISTICAL GUIDANCE. HIGHS IN THE LOWER 50S NORTH TO MID 50S
SOUTH...WHICH WILL FEEL EVEN COOLER WITH AFTER MIXING PRODUCING
OCCASIONAL NORTH-NORTHWESTERLY WIND GUSTS INTO THE MID TEENS.
SOME HIGH CLOUDS STREAMING ACROSS THE AREA LATE FRIDAY
NIGHT/SATURDAY MORNING MAY TEMPER WHAT WOULD OTHERWISE COULD BE
STRONG RADIATIONAL COOLING CONDITIONS. MIN TEMPS IN THE UPPER
THE UPPER 20S AND LOWER 30S FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 330 PM WEDNESDAY...
SATURDAY THOUGH MONDAY:
A DRY WEST/WNW FLOW ALOFT WILL PREVAIL ACROSS THE REGION THROUGH
MONDAY. HIGH PRESSURE CENTERED OVER THE CAROLINAS EARLY SAT WILL
WEAKEN AND SHIFT OFFSHORE SATURDAY/SUNDAY AS SHORTWAVE ENERGY
CURRENTLY IN THE PACIFIC NW TRACKS EAST ACROSS THE GREAT LAKES/NEW
ENGLAND. SUBSIDENCE IN THE WAKE OF THE AFOREMENTIONED WAVE WILL
ALLOW HIGH PRESSURE TO STRENGTHEN OVER THE OH VALLEY ON SUNDAY...
BUILDING INTO THE CAROLINAS SUN NIGHT (AS A DRY COLD FRONT) BEFORE
SETTLING OVER THE REGION ON MON. EXPECT DRY CONDITIONS WITH SLIGHTLY
BELOW NORMAL TEMPS ON SAT...NEAR NORMAL ON SUN...THEN SLIGHTLY BELOW
NORMAL AGAIN ON MON.
TUESDAY THROUGH THURSDAY:
FORECAST UNCERTAINTY REMAINS LARGE IN THIS PERIOD...WITH MAJOR
DIFFERENCES BETWEEN THE 12Z ECMWF/GFS MODELS ON THE EVOLUTION OF A
POTENTIALLY SIGNIFICANT STORM SYSTEM OVER THE MID-ATLANTIC REGION
MID NEXT WEEK. DESPITE THE AFOREMENTIONED DISAGREEMENT...LONG RANGE
MODEL GUIDANCE DOES AGREE THAT AN AIRMASS OF ARCTIC ORIGIN (~1045 MB
HIGH) WILL PLUNGE SOUTH FROM CANADA INTO THE CENTRAL CONUS EARLY
NEXT WEEK...BUILDING EAST TO THE MID-ATLANTIC COAST BY THE MIDDLE OF
NEXT WEEK AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS SOUTHEAST TOWARD
THE AREA. WITH THIS IN MIND...EXPECT SLIGHTLY BELOW NORMAL TEMPS AND
INCREASING CLOUD COVER ON TUE...WITH BELOW NORMAL TEMPERATURES AND
INCREASED CLOUD COVER ON WED/THU. PRECIP CHANCES ARE DIFFICULT TO
ASCERTAIN GIVEN SUCH LARGE DIFFERENCES IN THE EVOLUTION OF THE
AFOREMENTIONED STORM SYSTEM AMONG MODEL GUIDANCE...NOT TO MENTION
THE RANGE (DAY 6-7) IN THE FORECAST. AT THIS TIME...SUFFICIENT
CONSISTENCY (MODEL-TO-MODEL AND RUN-TO-RUN) EXISTS TO JUSTIFY THE
INCLUSION OF A 30% CHANCE OF PRECIPITATION IN THE DAY 6-7 PERIOD
(~WED). PRECIP CHANCES/AMOUNTS/TIMING (PERHAPS TYPE) WILL HIGHLY
DEPEND ON THE PRECISE EVOLUTION OF THE AFOREMENTIONED SYSTEM NEXT
WEEK...A SYSTEM THAT HAS YET TO EVOLVE. AS A RESULT...IT WOULD BE
UNWISE TO ACCEPT ANY SINGLE MODEL SOLUTION AT THIS RANGE. -VINCENT
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1240 AM FRIDAY...
VFR CONDITIONS WILL CONTINUE THROUGH THE 06Z VALID TAF PERIOD. A FEW
LOWER CLOUDS...STILL VFR...JUST EAST OF KRWI EARLY THIS MORNING
SHOULD STAY JUST EAST OF THAT TERMINAL...WITH THE RAP MODEL SHOWING
THE RELATIVE LOW-LEVEL MOISTURE GRADUALLY DIMINISHING THROUGH 12Z.
INCLUDED LLWS FOR A PERIOD EARLY THIS MORNING AT KGSO...KINT..AND
KRDU WHERE THE COMBINATION OF A GENERALLY DIMINISHING SURFACE
WIND...AND WSR-88D DATA WITH SLIGHTLY VEERING WINDS TO 40KT WITHIN
THE FIRST 2000FT...SUGGEST ITS OCCURRENCE. WINDS AT THE 2K FT LEVEL
SHOULD DIMINISH BY 12Z BASED ON BOTH THE NAM AND GFS MODEL
SOUNDINGS. FOR THE DAYLIGHT HOURS...A NORTHWEST WIND SHOULD CONTINUE
WITH A FEW SURFACE GUSTS APPROACHING 20KT WITH MIXING. WINDS
DIMINISH QUICKLY WITH SUNSET...FALLING AOB 5KT...POSSIBLY VEERING
SLIGHTLY MORE NORTH.
BEYOND THE 06Z VALID TAF PERIOD...VFR CONDITIONS SHOULD PREVAIL FOR
MUCH OF THE DEFINED PERIOD THROUGH TUESDAY. SURFACE WINDS BECOME
SOUTHWEST SATURDAY...THEN VEER MOSTLY WESTERLY SUNDAY. BEHIND A DRY
SURFACE FRONT...WINDS MAY VEER QUICKLY AROUND THE CLOCK MONDAY INTO
TUESDAY BEFORE BECOMING NORTHEAST AND POSSIBLY MODESTLY GUSTY
TUESDAY. DEPENDING ON THE MOISTURE AVAILABLE WITH A POSSIBLE SYSTEM
LATE IN THIS PERIOD...THERE IS THE POTENTIAL FOR SUB-VFR CLOUD
HEIGHTS...CURRENTLY A HIGHER PROBABILITY OF MVFR.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...BSD
SHORT TERM...CBL
LONG TERM...VINCENT
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
347 AM CST FRI NOV 8 2013
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 347 AM CST FRI NOV 8 2013
CHALLENGE WILL REVOLVE AROUND THE SYSTEM TODAY...ESPECIALLY
WHERE/IF SNOWFALL COULD OCCUR. 00Z MODELS IN GENERAL
AGREEMENT...BUT STILL DIFFER WITH DETAILS. COMPARING 00Z
MODELS...THE ECMWF IS STILL THE FURTHEST SOUTH WITH THE MAIN BAND
OF PRECIP (THE 500MB WAVE IS SOUTH OF OTHER MODELS). 06Z MODEL
RUNS ARE BEGINNING TO TREND TO THE ECMWF WITH THE LOCATION OF THE
500MB HEIGHTS. WILL USE A BLEND OF THE 00Z ECMWF ALONG WITH
INCOMING HIGH RESOLUTION MODELS (RAP/HRRR/NAM12). USING A
COMBINATION OF THESE MODELS BEGINS TO CLEAR UP THE PICTURE A
LITTLE BIT.
A LEAD BAND OF 700MB WARM AIR ADVECTION WILL MOVE THROUGH THE
REGION THIS MORNING...WITH SOME PRECIP RESULTING. THE LOW LEVELS
WILL REMAIN RELATIVELY DRY WHICH WILL LIMIT COVERAGE. 925MB TEMPS
ARE ABOVE FREEZING ACROSS THE FA...AND MOST OF WHAT FALLS THIS
MORNING SHOULD BE LIQUID (MAYBE MIXED WITH SNOW DVL BASIN).
SURFACE TEMPERATURES APPEAR TO BE RISING AT A FAST ENOUGH RATE
THAT FREEZING RAIN SHOULD NOT BE A CONCERN.
AS THE MAIN UPPER WAVE MOVES THROUGH THE REGION THIS AFTERNOON
AND EVENING...A COUPLE AREAS OF PRECIP SHOULD RESULT. THE HIGHER
RESOLUTION MODELS (THAT ARE ABLE TO PICK UP ON
FRONTOGENESIS/DEFORMATION) INDICATE A BAND OF PRECIP WILL DEVELOP
ACROSS THE NORTHERN FA BY MID-AFTERNOON. ANOTHER AREA OF PRECIP
WOULD THEN DEVELOP ACROSS THE SOUTHERN FA ASSOCIATED WITH FORCING
FROM THE UPPER LOW. THUS...MOST AREAS SHOULD RECEIVE MEASURABLE
PRECIP AT SOME TIME THIS AFTERNOON OR EVENING. FOLLOWED A BLEND OF
925MB TEMPS FROM THE NAM/RAP/GFS/ECMWF FOR P-TYPE. THIS INDICATES
AREAS NEAR THE INTERNATIONAL BORDER INTO THE BEMIDJI AREA COULD BE
ALL SNOW. THE RAP IS A BIT WARMER WITH LOW LEVEL TEMPS...WHICH
WOULD MEAN MOST AREAS LIQUID...WITH ONLY ROSEAU TO BAUDETTE SNOW.
GIVEN THAT THE RAP USUALLY VERIFIES BEST WITH 925MB TEMPS...THE
WARM AIRMASS CURRENTLY IN PLACE...MUCH OF THE PRECIP WILL FALL
DURING THE DAYTIME HOURS...AND NO CLEAR ORGANIZED BANDING
POTENTIAL...WILL LIMIT SNOWFALL ACCUMULATION TO THE
ROSEAU...BAUDETTE...BEMIDJI AREA. CURRENTLY THINKING 1-2
INCHES...BUT WILL NEED TO WATCH WHERE/IF HEAVIER BANDS SET UP.
SATURDAY...COLD FRONT WILL MOVE THROUGH THE REGION. SNOW SHOWERS
POSSIBLE ACROSS NW MN WITH THE PASSAGE OF AN UPPER WAVE. WINDY
CONDITIONS LIKELY...BUT CURRENT INDICATIONS ARE THAT SPEEDS WILL
BE BELOW ADVISORY CRITERIA.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 347 AM CST FRI NOV 8 2013
SAT NIGHT-SUN NIGHT...A STRONGER COLD FRONT WILL MOVE THROUGH THE
REGION...LIKELY ON SUNDAY. AIRMASS IS DRY...BUT COULD BE SOME
ISOLATED SNOW SHOWERS. ALSO COULD BE A BRIEF PERIOD OF WINDY
CONDITIONS ALONG WITH THE FROPA.
MONDAY-THURSDAY...THE UPPER AIR PATTERN WILL BRIEFLY AMPLIFY FROM
THE NORTHWEST EARLY IN THE WEEK...WHILE AT THE SFC AN ARCTIC HIGH
DROPS SOUTHWARD. MODELS LARGELY KEEP A WEAKENING BAND OF LIGHT
SNOW ASSOCIATED WITH THE ADVANCING MID-LEVEL BAROCLINIC ZONE SOUTH
AND WEST OF THE FORECAST AREA...WITH A DRY AND UNSEASONABLY COLD
AIR MASS OVER THE REGION FOR THE START OF THE WEEK. TEMPS AT 925
MB WILL FALL TO AROUND -12 TO -15C ON MONDAY. THUS...HIGHS ON
MONDAY SHOULD NOT RISE HIGHER THAN THE 20S...WHILE MONDAY NIGHT
LIKELY WILL BE THE COLDEST NIGHT...WITH SOME SINGLE DIGIT LOW
TEMPS...AS THE SFC HIGH CENTER SINKS SOUTH ACROSS THE DAKOTAS.
HOWEVER...THE OVERALL FLOW PATTERN REMAINS PROGRESSIVE...AND MODELS
INDICATE A TRANSITION TO A FLATTER LESS AMPLIFIED FLOW FOR THE
MIDDLE AND END OF THE WEEK. AS A RESULT...TEMPS SHOULD QUICKLY
RETURN TO MORE SEASONABLE VALUES. THE UNEVENTFUL WEATHER PATTERN IS
EXPECTED TO CONTINUE THROUGH THE END OF THE PERIOD...WITH ONLY
RATHER WEAK SHORTWAVE TROUGHS PROPAGATING THROUGH THE FLOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1154 PM CST THU NOV 7 2013
LITTLE CHANGE FROM THE PREVIOUS DISCUSSION. HIGH CLOUDS-MID CLOUDS
WILL MOVE EAST INTO THE VALLEY 12-14Z THEN INTO BEMIDJI AREA BY
16Z. SOUTH-SOUTHEAST WINDS WILL INCREASE AFTER 12Z AND GUSTY AT
TIMES TO 20 KTS IN THE RED RIVER VALLEY. SFC LOW WILL MOVE THRU
FCST AREA ND-MN THIS AFTN-THIS EVE WITH MAIN PRECIP NORTHERN FCST
AREA WITH SNOW CHANCES BETTER NORTH OF DVL-GFK-BJI WITH RAIN/SNOW
MIX IN THE MIDDLE THEN MOSTLY -RA IN THE SOUTHERN FCST AREA.
MOSTLY VFR CIGS UNTIL LATER TODAY WHEN CIGS MAY DROP TO MVFR
LEVELS. ALSO MVFR VSBSYS LIKELY IN -SN AREAS (TVF-BJI) LATE TODAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...TG
LONG TERM...TG/MAKOWSKI
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1030 AM EST FRI NOV 8 2013
.SYNOPSIS...
MUCH COLDER AIR STREAMS ACROSS SOUTHERN NEW ENGLAND TODAY BEHIND
YESTERDAY/S COLD FRONT. A FEW SPRINKLES OR FLURRIES MAY ACCOMPANY
THE COLDER AIRMASS. A RIDGE OF HIGH PRES BUILDS ACROSS NEW
ENGLAND SATURDAY...PROVIDING DRY WEATHER ALONG WITH A DIMINISHING
WIND. LOW PRESSURE WILL MOVE OVER NORTHERN NEW ENGLAND LATER THIS
WEEKEND AND MAY YIELD A FEW LIGHT SHOWERS SATURDAY NIGHT THROUGH
SUNDAY NIGHT. ANOTHER COLD FRONT MAY BRING A ROUND OF SHOWERS TO
THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1030 AM UPDATE...
IN BREVITY...
BROAD-SCALE TROUGHING THROUGH WHICH A WEAKER DISTURBANCE IS
ANTICIPATED BY THE AFTERNOON WILL INVOKE MODEST WEST-NORTHWESTERLY
FLOW THROUGH THE ATMOSPHERIC COLUMN LENDING TO CONTINUED COLD AIR
ADVECTION ALOFT. PER THE 08.12Z CHATHAM AND ALBANY SOUNDINGS...A
WELL-MIXED PROFILE EVEN BEYOND H8 IS PLAUSIBLE.
TEMPERATURES...
MID- TO UPPER-40S WITH COOLER SPOTS ALONG THE HIGHER TERRAIN OF
CENTRAL AND WESTERN NEW ENGLAND...COMBINED WITH WINDS WILL MAKE
CONDITIONS SEVERAL DEGREES COOLER. H85 TEMPERATURES AROUND -6 TO
-8C.
WINDS...
PRESENTLY RADAR WIND PROFILERS EXHIBITING 20 KT FLOW AT H925. HRRR
AND RAP NEAR-TERM SOLUTIONS SUGGEST AROUND 30 KT FLOW UP TO H8
THROUGH THE AFTERNOON. CONSIDERING A WELL-MIXED PROFILE...EXPECT
WIND GUSTS OF 25 TO 30 MPH AT THE SURFACE DURING MAXIMUM HEATING
OF THE DAY...TAPERING WITH SUNSET /EXCEPT ALONG THE NEAR-SHORE IN
PROXIMITY TO WARMER WATERS/.
FORECAST GUIDANCE SUGGESTS AN AMPLIFICATION OF LOW-LEVEL WINDS
TOWARDS THE END OF THE PERIOD WITH THE SECOND WEAKER SHORTWAVE.
H5 WINDS ARE SEEN ENHANCING IN RESPONSE TO A TIGHTENING GRADIENT
WITH THE EXITING DISTURBANCE AND THE BUILDING RIDGE TO THE WEST...
AND MID-LEVEL LAPSE RATES ARE FAIRLY STEEP. BUT BY THE POINT OF
LOW-LEVEL WIND ENHANCEMENT...THE BOUNDARY LAYER DECOUPLES. WILL
STILL NEED TO MONITOR FOR THE PRESENCE OF GALES OVER THE WATERS.
PRECIPITATION...
WHILE THE LAKE-EFFECT MACHINE IS IN OPERATION...DOWNSLOPING
MOTIONS EAST OF THE BERKSHIRES WILL LIKELY RESULT IN SUPPRESSION
OF ACTIVITY DOWNSTREAM OF THE CONNECTICUT RIVER VALLEY. A SPOT
RAIN AND/OR SNOW SHOWER IS POSSIBLE FOR WESTERN MASSACHUSETTS AND
SOUTHERN NEW HAMPSHIRE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT...
AS MENTIONED ABOVE A SECOND PULSE OF GUSTY WINDS WILL OCCUR THIS
EVENING BEHIND DEPARTING SHORT WAVE TROUGH THAT WILL PROVIDE A
REINFORCING SURGE OF COLD AIR ADVECTION AND ASSOCIATED SUBSIDENCE.
TEMPS WILL FALL INTO THE 20S BUT WILL FEEL EVEN COLDER GIVEN GUSTY
NORTHWEST WINDS. ANY DIURNAL CLOUDS FROM TODAY WILL ERODE TONIGHT
GIVING WAY TO MOSTLY CLEAR SKIES.
SATURDAY...
SUNSHINE TO START BUT CLOUDS QUICKLY INCREASE AS WARM FRONT
APPROACHES FROM NY STATE. BEST DEEP LAYER MOISTURE AND LIFT TRACK
ACROSS NY AND NORTHERN NEW ENGLAND. THUS DRY WEATHER WILL LIKELY
PREVAIL ACROSS SOUTHERN NEW ENGLAND. AS FOR WINDS...AS PGRAD WEAKENS
WINDS WILL SLACKEN BY SAT AFTERNOON. TEMPS ABOUT THE SAME AS TODAY
WITH HIGHS 45-50. HOWEVER WITH LIGHTER WINDS SAT IT WILL NOT FEEL AS
COLD.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGHLIGHTS...
* ISOLATED SHOWERS AT MOST SAT NIGHT/SUN
* SECOND COLD FRONT BRINGS CHILLY TEMPS FOR TUE/WED
* POTENTIAL STORM IN THU TIME FRAME
OVERVIEW AND MODEL PREFERENCES...
08/00Z LONG RANGE GUIDANCE SUITE CONTINUES TO SHOW FAIRLY GOOD
AGREEMENT THROUGH THE MID RANGE FORECAST. HOWEVER...FOR MID TO
LATE NEXT WEEK...SEVERAL DIVERGING SOLUTIONS ARE APPARENT. IN
LOOKING AT GLOBAL TELECONNECTIONS...THE PNA LOOKS TO SLIGHTLY
TREND POSITIVE WHILE THE NAO SHOWS VARIABILITY IN ITS TREND TOWARD
NEUTRAL. THE AO IS REALLY THE ONLY TELECONNECTION THAT SHOWS A
STRONG RAPID DECLINE FROM HIGHLY POSITIVE TO NEAR NEUTRAL. WHAT
THIS ALL SUGGESTS IS A LOT OF VARIABILITY IN THE LONGWAVE PATTERN
ACROSS THE NRN CONUS AND ATLANTIC BETWEEN ENSEMBLE MEMBERS.
THEREFORE...WHILE A RAPID DIP IN THE AO MIGHT BE A SIGNAL...THE
VARIABILITY SUGGESTS THE JURY MAY STILL BE OUT REGARDING THE
DEVELOPMENT OF A MUCH MORE AMPLIFIED PATTERN FOR LATE NEXT WEEK.
IN TERMS OF THE DETERMINISTIC VS. ENSEMBLE MEMBERS...THE ECMWF IS
MUCH MORE AMPLIFIED THAN THE REST OF THE OPERATIONAL MODELS AND
EVEN ITS OWN ECENS MEAN. THE GFS ON THE OTHER HAND IS MUCH MORE
PROGRESSIVE...WHILE ITS GEFS MEMBERS SHOW SIGNIFICANT SPREAD. THE
UKMET LAY BETWEEN THE TWO SOLUTIONS. IN SUM...WILL USE A BLEND OF
OPERATIONAL GFS/ECMWF FOR THE MID TERM GIVEN THE AGREEMENT...WITH
A BLEND OF HPC/GFS/ECMWF FOR LATE NEXT WEEK SUCH THAT ALL
SOLUTIONS WITHIN THE ENVELOPE ARE ACCOUNTED FOR. HOWEVER...WILL
NEED TO WATCH THIS DEVELOP AS ALL THE PLAYERS LINE UP IN THE NEXT
SEVERAL DAYS GIVEN THAT THE DIVING AO SIGNAL MAY SUPPORT THE MORE
AMPLIFIED PATTERN SHIFT.
WX FOR SRN NEW ENGLAND WILL INITIALLY BE DEFINED BY NEARLY
UNIFORM ZONAL FLOW AT THE BASE OF A LONGWAVE TROF STRETCHING FROM
THE CANADIAN PRAIRIE INTO THE MARITIMES. A COUPLE OF SHORTWAVES
WILL SLIDE TO THE N WITH A COUPLE OF WEAK CLIPPERS IN TOW LATE SAT
NIGHT AND AGAIN BY TUE. IN BETWEEN THESE FEATURES DRY HIGH PRES
AND A COOLER THAN NORMAL AIRMASS WILL REMAIN IN PLACE. AS
MENTIONED ABOVE THE DEPTH OF THE FINAL DEPTH OF THE LONGWAVE TROF
ACROSS THE ERN SEABOARD BY LATE NEXT WEEK WILL ULTIMATELY DEFINE
THE WX FROM WED-ONWARD.
DETAILS...
SAT NIGHT INTO SUN...
FIRST IN A SERIES OF WEAK CLIPPER SYSTEMS WILL RIDE ALONG THE
CYCLONIC SHEAR SIDE OF THE ZONAL JET ACROSS THE REGION...IN
ESSENCE...THROUGH NRN NEW ENGLAND. GIVEN THIS LEAVES THE SRN NEW
ENGLAND STATES ON THE CLIMATOLOGICALLY DRY SIDE OF THIS
CLIPPER...AND GUIDANCE CONTINUES TO SHOW LOW MOISTURE CONTENT AND
WEAK LIFT...EXPECT THAT THIS WILL PASS WITH LITTLE FANFARE. WILL
CONTINUE TO HIGHLIGHT ONLY SLIGHT CHANCE POPS WITH A FOCUS ON THE
WRN SLOPES OF HIGHER TERRAIN AND IN SRN NH...WHERE LIFT WILL BE
ENHANCED. HOWEVER...WOULD NOT BE SURPRISED IF MUCH OF THE REGION
REMAINS DRY. TEMPERATURES WILL BE NEAR NORMAL FOR EARLY NOV...AS
OVERNIGHT LOWS WILL BE A BIT WARMER GIVEN THE EXPECTED CLOUD COVER
AND COLD ADVECTION DURING THE DAY SUN WILL BE FIGHTING DOWNSLOPE
FLOW AND INCREASING SUNSHINE THROUGH THE DAY. LOWS WILL REMAIN IN
THE LOW 30S TO LOW 40S...WHILE HIGHS WILL RANGE FROM THE MID 40S
TO MID 50S.
SUN NIGHT THROUGH MON...
HIGH PRES REGAINS CONTROL WITH A COOL START SUN NIGHT...BUT
RETURN FLOW AND WARMING TEMPS ON MON AHEAD OF A COLD FRONT. DRY WX
PREVAILS WITH LOWS BELOW NORMAL AND HIGHS NEAR TO SLIGHTLY BELOW
NORMAL DUE TO A COOLER START.
MON NIGHT INTO TUE NIGHT...
A COLD FRONT CROSSES THE REGION. AM NOTING A BIT MORE MOISTURE IN
MODEL SOUNDINGS AND SLIGHTLY STRONGER LIFT THAN PREVIOUS RUNS SO
WILL HIGHLIGHT SOME SLIGHT TO CHANCE POPS PARTICULARLY TUE NIGHT
INTO EARLY TUE DAY. INITIALLY THE AIRMASS MAY BE COOL ENOUGH TO
SUPPORT SOME OVERNIGHT SNOWS...BUT WITH LITTLE TO NO ACCUMULATION
EXPECTED. TEMPERATURES BEGIN NEAR NORMAL...BUT LOOK TO POSSIBLY
COOL RAPIDLY BEHIND THE FRONT ON TUE.
WED...
COLD AIRMASS AND HIGH PRES LOOK TO BUILD IN AS THE COLD FRONT
STALLS SOMEWHERE ALONG THE MID ATLANTIC STATES.
LATE NEXT WEEK...
AS MENTIONED ABOVE THERE CONTINUES TO BE A LOT OF UNCERTAINTY FOR
THIS PORTION OF THE FORECAST...MAINLY WITH THE DEPTH/ORIENTATION
OF LONGWAVE TROF ACROSS THE NORTHEAST AND WHERE/WHETHER A WAVE OF
LOW PRES DEVELOPS ALONG THE TROF TO THE S. WILL NEED TO BE
MONITORED...AS ECMWF CONTINUES TO SUPPORT A COASTAL LOW.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY/...HIGH CONFIDENCE.
VFR. NORTHWEST WINDS WITH GUSTS AROUND 20 TO 25 KTS. CAN NOT RULE
OUT GUSTS UP TO AROUND 30 KTS. ISOLATED -SHRA/-SHSN MAINLY NORTH
AND WEST OF IJD- ORH- EEN. SCT-BKN 040-080 CIGS. WINDS WILL REMAIN
BRISK OVERNIGHT ALONG THE NEAR-SHORE TERMINALS...BUT EXPECT
CONDITIONS TO TAPER INTO SATURDAY WITH SKC.
KBOS TAF...HIGH CONFIDENCE IN TAF. NORTHWEST WINDS GUSTING AROUND
25 KTS.
KBDL TAF...HIGH CONFIDENCE IN TAF. ISOLATED -SHRA POSSIBLE.
NORTHWEST WINDS GUSTING AROUND 25 KTS.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT THRU TUE...HIGH CONFIDENCE.
MAINLY VFR. A FEW ISOLATED MVFR CIGS/VSBYS POSSIBLE SAT NIGHT INTO
EARLY SUN ESPECIALLY ACROSS THE N OR HIGHER TERRAIN WHERE SOME
ISOLATED -SHRA/-SHSN ARE POSSIBLE. NW WIND GUSTS 25+ POSSIBLE AGAIN
ON SUN AFTERNOON/EVENING.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
FORECAST CONFIDENCE HIGH THROUGH SATURDAY.
TODAY/TONIGHT...NW WINDS 20-30KT. OFFSHORE RAIN SHOWERS WITH COLD
AIR FLOWING ACROSS THE RELATIVELY WARM WATERS. CHOPPY/STEEP SEAS ON
THE SOUTHERN WATERS AS LEFTOVER S-SW SWELLS COMBINE WITH INCREASING
WNW WIND WAVES.
OUTLOOK...SAT NIGHT THROUGH TUE
SATURDAY...WINDS SLACKEN AS RIDGE OF HIGH PRES MOVES INTO THE NE.
SEAS WILL SUBSIDE SLOWLY.
SUN THRU TUE...
WINDS PICK UP AGAIN ON SUN WITH THE POSSIBILITY OF GALE FORCE
WIND GUSTS BY SUN EVENING...BUT A SMALL CRAFT ADVISORY IS LIKELY
NONETHELESS INTO THE DAY MON. SEAS ALSO BUILD ESPECIALLY ON THE
OCEAN WATERS WITH 5+ FEET POSSIBLE. AFTER A BRIEF LULL LATE DAY
MON...SCA CONDITIONS RETURN BEHIND ANOTHER COLD FRONT ON TUE.
THERE IS A POTENTIAL...ALBEIT LOW THIS FAR OUT...OF AN EPISODE OF
SIGNIFICANT WINDS/SEAS MID TO LATE NEXT WEEK DUE TO EXPECTED
MIXING WITH COLD E TO NE COLD FLOW OVER RELATIVELY WARM OCEAN.
&&
.FIRE WEATHER...
ELEVATED FIRE WEATHER CONCERNS CONTINUE TODAY ACROSS NORTHERN
CT/WESTERN-CENTRAL MA AND SOUTHWEST NH WHERE RAINFALL THURSDAY WAS
LESS THAN 0.25 INCHES. THUS DRY CONDITIONS CONTINUE ALONG WITH GUSTY
NW WINDS OF 15 TO 25 MPH WITH GUSTS UP TO 35 MPH TODAY. FARTHER
SOUTHEAST HEAVIER RAINFALL OCCURRED THURSDAY ACROSS RI AND EASTERN
MA...WHERE RAIN TOTALS WERE 0.25-0.50 INCHES AND OVER 1 INCH ACROSS
CAPE COD AND THE ISLANDS! AS A RESULT FIRE WEATHER IS LESS OF A
CONCERN ACROSS THIS AREA. MIN RH VALUES ACROSS THE AREA WILL RANGE
FROM 30-45 PERCENT.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ230>237-
250-251-254>256.
&&
$$
SYNOPSIS...NOCERA/DOODY
NEAR TERM...NOCERA/DOODY/SIPPRELL
SHORT TERM...NOCERA
LONG TERM...DOODY
AVIATION...NOCERA/DOODY
MARINE...NOCERA/DOODY
FIRE WEATHER...NOCERA/DOODY
AREA FORECAST DISCUSSION
NWS RALEIGH NC
958 AM EST FRI NOV 08 2013
.SYNOPSIS...
HIGH PRESSURE BUILDS OVER THE AREA TODAY AND REMAINS IN PLACE
THROUGH MUCH OF THE WEEKEND. A DRY COLD FRONT MOVES THROUGH THE
REGION SUNDAY. ANOTHER HIGH THEN BUILDS OVER THE REGION FOR MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM FRIDAY...
TODAY...SURFACE HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE
WEST AS THE MID LEVEL TROUGH AXIS MOVES OFFSHORE. WATER VAPOR
IMAGERY AND LATEST UPPER AIR ANALYSIS SHOWS DRY AIR OVER THE REGION
WHICH WILL RESULT IN SUNNY SKIES TODAY. AFTER A CHILLY START THIS
MORNING...LOW LEVEL THICKNESS VALUES ARE ONLY PROGGED TO RISE TO
NEAR 1320M AND THIS SUGGESTS HIGH TEMPS IN THE MID/UPPER 50S
(WARMEST IN THE SOUTH). THERE COULD ALSO BE SOME WIND GUSTS INTO THE
MID TEENS...WHICH WOULD MAKE IT FEEL EVEN CHILLIER.
TONIGHT...LOW AMPLITUDE RIDGING ALOFT MOVES IN LATE TONIGHT...BUT
DESPITE THE WESTERLY FLOW ALOFT...THE GENERAL CONFLUENCE OF THAT
FLOW SHOULD KEEP MUCH IF NOT ALL OF THE HIGH CLOUDS OVER THE
SOUTHERN PLAINS TO THE WEST OF THE AREA...WITH MAYBE A FEW CIRRUS
EEKING INTO THE AREA. PATCH OF LOWER CLOUDS OVER PARTS OF HALIFAX
AND EDGECOMBE COUNTIES FINALLY DRIFTING SOUTHEAST IN CONCERT WITH
THE RAP MODEL SOUNDINGS...WHICH SHOW THE LOW-LEVEL MOISTURE
DIMINISHING IN THAT AREA THROUGH 10Z. UNDER SUBSIDENCE...NEGATIVE K
INDEX VALUES...AND AN 850MB THETA-E TROUGH...ANTICIPATE CLEAR OR
MOSTLY CLEAR CONDITIONS TONIGHT. LOWS TONIGHT WILL BE MORE VARIABLE
UNDER A LIGHT WIND...MOSTLY AROUND 30 BUT SOME MID TO UPPER 20S
POSSIBLE IN THE TYPICALLY COOLER AREAS...AND A FEW MID 30S SOUTHEAST.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 230 AM FRIDAY...
THE LOW AMPLITUDE RIDGE PROGRESSES ACROSS CENTRAL NORTH CAROLINA
SATURDAY...WITH WEAK UPPER-LEVEL TROUGHING MOVING INTO CENTRAL NORTH
CAROLINA SATURDAY NIGHT. THE MAIN DIFFERENCE BETWEEN THE NAM AND THE
GFS IS THE AMOUNT OF UPPER-LEVEL MOISTURE AND THE STRENGTH OF THE
MID-LEVEL SHORTWAVES IN THE WESTERLY FLOW ALOFT. THE GFS IS
NOTICEABLY MORE MOIST IN THE HIGH-CLOUD PORTION OF THE AIR MASS WITH
STRONGER SHORTWAVES...WHILE THE NAM IS DRIER AND WEAKER...
RESPECTIVELY. THE GFS WOULD PORTEND A GOOD INCREASE OF CIRRUS LATE
SATURDAY AND SATURDAY NIGHT ESPECIALLY ALONG AND SOUTH OF U.S. 64...
WHILE THE NAM WOULD NOTE MUCH LESS OR THINNER SUCH CLOUDS. THE
CANADIAN CLOUD COVER MODEL...USUALLY GOOD WITH HIGH-LEVEL CLOUDS...
IS MORE AKIN TO THE NAM...AND FOR THIS FORECAST WILL HAVE SKIES
PARTLY CLOUDY AT WORST LATE SATURDAY AFTERNOON AND SATURDAY NIGHT...
WITH THE HIGHER QUANTITY OF CLOUDS OVER THE SOUTHERN TWO TIERS OF
COUNTIES RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA. 1000-850MB
THICKNESSES WARM DURING THE DAY SATURDAY...AND THE SURFACE WIND
VEERS SOUTHWEST. WITH A DRY AIR MASS...THE GUIDANCE FORECAST OF A
NEARLY 30-DEGREE DIURNAL SEEMS POSSIBLE...FOR HIGHS AROUND 60.
OVERNIGHT LOWS SATURDAY NIGHT ARE A LITTLE MORE TRICKY DEPENDING ON
HOW MUCH WIND EXISTS...AS WINDS OFF OF THE SURFACE INCREASE AHEAD OF
THE NEXT DRY SURFACE FRONT. BASED ON THE POTENTIAL FOR A LITTLE
STIRRING AND THE GUIDANCE TENDENCY TO BE COOL IN THE NIGHT AHEAD OF
A SURFACE BOUNDARY...WILL SHOW A DEFINITE LEAN TOWARD THE WARMER MAV
MOS SATURDAY NIGHT. LOWS WITHIN TWO OR THREE DEGREES EITHER SIDE OF
40.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...
FOR SUNDAY THROUGH MONDAY NIGHT: QUIET AND DRY BUT TURNING COOLER.
EXPECT A FEW MID AND HIGH CLOUDS OVER THE REGION SUNDAY MORNING...
MOST MARKEDLY OVER SRN NC AS MID/HIGH CLOUDS NOW OVER NRN MEX INTO
TX SWEEP EASTWARD ACROSS THE GULF AND SOUTHEAST STATES. THE MID
LEVEL SHORTWAVE TROUGH NOW OVER MT/WY WILL DRAW IN ADDITIONAL ENERGY
FROM THE YUKON AS IT TRACKS QUICKLY EASTWARD ACROSS THE GREAT
LAKES/NORTHEAST INTO SUNDAY...SWEEPING A WEAK DRY COOL FRONT THROUGH
THE MIDATLANTIC REGION. THIS MID LEVEL TROUGH SWEEPING BY JUST TO
OUR NORTH SHOULD BRING A FEW HIGH CLOUDS ACROSS THE VA BORDER
SECTIONS...WHICH COULD BE OROGRAPHICALLY ENHANCED EARLY SUNDAY AS
SUGGESTED BY FORECAST SOUNDINGS. NEVERTHELESS...WE SHOULD SEE PLENTY
OF SUNSHINE FOR MUCH OF SUNDAY AS A GENERALLY DRY AND STABLE COLUMN
PERSISTS WITH A DOWNSLOPE WNW LOW LEVEL FLOW. 1000-850 MB
THICKNESSES ARE EXPECTED TO BE SLIGHTLY ABOVE NORMAL AHEAD OF THE
WEAK FRONT...SUPPORTING HIGHS SUNDAY OF 64-69. THE FRONT SHOULD PUSH
THROUGH THE AREA SUNDAY EVENING WITH THE COOLER SURFACE HIGH
STARTING TO BUILD IN FROM THE WEST. THE MSLP PATTERN INDICATES THAT
SURFACE WINDS SHOULD STAY UP ENOUGH IN THE EAST TO CURB RADIATIONAL
COOLING SUNDAY NIGHT...BUT WESTERN SECTIONS CLOSER TO THE HIGH
CENTER SHOULD GO NEARLY CALM. LOWS 32-40. MOSTLY SUNNY/DRY/COOL
MONDAY WITH THE SURFACE HIGH PASSING QUICKLY WEST-TO-EAST OVER NC...
AHEAD OF THE NEXT FRONT. SHOULD SEE AN INCREASE IN HIGH CLOUDS
MONDAY NIGHT WITH STRENGTHENING MID LEVEL FLOW OVER NC IN RESPONSE
TO THE STRONG VORTEX CROSSING SRN ONTARIO/QUEBEC. TEMPS A BIT BELOW
NORMAL MONDAY...HIGHS 60-65 AND LOWS 37-42.
FOR TUESDAY THROUGH THURSDAY: STILL ANTICIPATING A BREAK IN THE
QUIET WEATHER...AS A DEEP MID LEVEL SHORTWAVE TROUGH AND
ACCOMPANYING POLAR SURFACE FRONT DROP SSE TOWARD NC. SURPRISINGLY...
AGREEMENT AMONG THE MODELS IS ACTUALLY WORSE THAN IT WAS WITH
YESTERDAY`S RUNS. THE 00Z/08 GFS OVER THE LAST 4 RUNS HAS TRENDED
LESS AMPLIFIED...MORE PHASED...DRIER...AND MUCH MORE PROGRESSIVE
WITH THE MID LEVEL TROUGH SWINGING THROUGH THE EASTERN HALF OF THE
CONUS...AND IT LACKS A CLOSED LOW IN FAVOR OF A MOISTURE-STARVED MID
LEVEL TROUGH PASSAGE. THE ECMWF HAS BEEN QUITE CONSISTENT IN ITS
LAST 4 RUNS IN CLOSING OFF AN INTENSE VORTEX OVER KY/TN/SRN
APPALACHIANS LATE WED/WED NIGHT WHICH WOBBLES EASTWARD BEFORE
LIFTING OUT LATE THU... A SCENARIO ALSO HINTED AT BY THE LATEST GEFS
RUNS. THE 00Z/08 ECMWF GENERATES ABUNDANT FORCING FOR ASCENT OVER NC
AND OFF OUR COAST...FOSTERING DEVELOPMENT OF AN EXPLOSIVE COASTAL
LOW ALONG THE NEARSHORE BAROCLINIC ZONE...WHICH IN TURN SPREADS A
LOT OF WRAPAROUND PRECIP OVER THE INLAND SOUTHEAST AND MIDATLANTIC
LATE TUE NIGHT THROUGH WED EVENING. WHILE THE ECMWF HAS HAD LITTLE
SUPPORT FROM ITS ENSEMBLE MEAN...IT WOULD BE FOOLHARDY TO TOTALLY
DISCOUNT IT...BASED ON BOTH ITS CONSISTENCY AND ITS HISTORICAL
PERFORMANCE. BUT GIVEN THAT THIS IS A HIGHLY ANOMALOUS AND
CLIMATOLOGICALLY UNUSUAL SOLUTION...WILL CONTINUE WITH A
MIDDLE-OF-THE-ROAD APPROACH TO THIS EVENT...HOLDING CLOSER TO
CLIMATOLOGY THAN TO ANY EXTREME...BUT CERTAINLY THIS POSSIBLE STORM
BEARS WATCHING. APART FROM THE MODEL DIFFERENCES WITH QPF AMOUNT AND
PLACEMENT...THERE IS LITTLE DOUBT THAT THE INCOMING AIR MASS BEHIND
THE FRONT WILL BE QUITE COLD...WITH PROJECTED LOW LEVEL THICKNESSES
DROPPING TOWARD 1280 M...NEARLY 60 M BELOW NORMAL...AND BOTH THE GFS
AND ECMWF TAKING 850 MB TEMPS DOWN TO -7C TO -10C. CURRENT TEMPS
WITHIN THIS AIR MASS (NOW OVER NRN YUKON/NRN NW TERRITORIES AND THE
BEAUFORT SEA) ARE WELL BELOW ZERO FAHRENHEIT...AND THIS AIR MASS
WILL HAVE LIMITED TIME TO MODIFY BEFORE IT ARRIVES. PARTIAL
THICKNESSES FROM THE OPERATIONAL GFS AND ECMWF STILL SUGGEST A
POTENTIAL FOR WINTRY PRECIP...HOWEVER THE OPTIMAL PATTERN FOR A LOT
OF COLD AIR IN NC AND THE OPTIMAL PATTERN TO GET SUFFICIENT MOISTURE
INTO NC ARE USUALLY VERY DIFFERENT. WITH THE OPERATIONAL MODEL
SOLUTIONS SO DIVERGENT...WE CANNOT AT THIS TIME STATE A PREFERRED
SCENARIO WITH ANY CONFIDENCE. WILL STAY WITH CHANCE POPS EARLY WED
MORNING INTO THU AND WILL KEEP ANY PRECIP AS JUST COLD RAIN FOR
NOW...BUT WE WILL CLOSELY MONITOR MODEL AND OBSERVED TRENDS OVER THE
NEXT SEVERAL DAYS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 610 AM FRIDAY...
VFR CONDITIONS WILL CONTINUE THROUGH THE 12Z VALID TAF PERIOD. THE
WSR-88D VAD WIND PROFILE SHOWED A TREND TOWARD LIGHTER WINDS JUST
OFF OF THE SURFACE JUST BEFORE DAWN...AND ALTHOUGH THE LATEST AMDAR
SOUNDING FROM KRDU HAD A SLIGHTLY STRONGER WIND...THE DIMINISHING
TREND AND THE ALREADY MARGINAL LLWS CRITERIA WILL RESULT IN THE LACK
OF AN LLWS MENTION IN THE 12Z VALID TAF. VERY EARLY THIS MORNING...
THERE COULD STILL BE A NORTHWEST-TO-NORTH WIND OF 30 TO 35KT AT OR
JUST ABOVE 2000FT. FOR THE DAYLIGHT HOURS...A SURFACE NORTHWEST WIND
SHOULD CONTINUE WITH A FEW SURFACE GUSTS APPROACHING 20KT WITH
MIXING. WINDS DIMINISH QUICKLY WITH SUNSET...FALLING AOB 5KT...
POSSIBLY VEERING SLIGHTLY MORE NORTH EARLY BEFORE BECOMING GENERALLY
CALM AND VARIABLE...EXCEPT LIGHT NORTHEAST AT KFAY.
BEYOND THE 12Z VALID TAF PERIOD...VFR CONDITIONS SHOULD PREVAIL FOR
MUCH OF THE DEFINED PERIOD THROUGH TUESDAY. SURFACE WINDS BECOME
SOUTHWEST SATURDAY...THEN VEER MOSTLY WESTERLY SUNDAY. BEHIND A DRY
SURFACE FRONT...WINDS MAY VEER QUICKLY AROUND THE CLOCK MONDAY INTO
TUESDAY BEFORE BECOMING NORTHEAST AND POSSIBLY MODESTLY GUSTY
TUESDAY. DEPENDING ON THE MOISTURE AVAILABLE WITH A POSSIBLE SYSTEM
LATE IN THIS PERIOD...THERE IS THE POTENTIAL FOR SUB-VFR CLOUD
HEIGHTS...CURRENTLY A HIGHER PROBABILITY OF MVFR.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...KRR/DJF
SHORT TERM...DJF
LONG TERM...HARTFIELD
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
610 AM EST FRI NOV 08 2013
.SYNOPSIS...
HIGH PRESSURE BUILDS OVER THE AREA TODAY AND REMAINS IN PLACE
THROUGH MUCH OF THE WEEKEND. A DRY COLD FRONT MOVES THROUGH THE
REGION SUNDAY. ANOTHER HIGH THEN BUILDS OVER THE REGION FOR MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM FRIDAY...
WATER VAPOR IMAGERY SHOWS THE TROUGH AXIS ALOFT MOVING EAST...AND
BOTH THE NAM AND THE GFS SUGGEST THE SOUTHERN END OF THIS AXIS WILL
PUSH THROUGH CENTRAL NORTH CAROLINA THROUGH MIDDAY. THE AIR MASS IS
FAIRLY DRY ALOFT...AND BUFR SOUNDINGS FROM BOTH THE NAM AND THE GFS
SHOW A DRY AIR MASS VIRTUALLY THROUGHOUT THE COLUMN THROUGH
TONIGHT...WITH PRECIPITABLE WATER VALUES BELOW NORMAL...AT OR BELOW
A QUARTER-INCH. LOW AMPLITUDE RIDGING ALOFT MOVES IN LATE TONIGHT...
BUT DESPITE THE WESTERLY FLOW ALOFT...THE GENERAL CONFLUENCE OF THAT
FLOW SHOULD KEEP MUCH IF NOT ALL OF THE HIGH CLOUDS OVER THE
SOUTHERN PLAINS TO THE WEST OF THE AREA...WITH MAYBE A FEW CIRRUS
EEKING INTO THE AREA. PATCH OF LOWER CLOUDS OVER PARTS OF HALIFAX
AND EDGECOMBE COUNTIES FINALLY DRIFTING SOUTHEAST IN CONCERT WITH
THE RAP MODEL SOUNDINGS...WHICH SHOW THE LOW-LEVEL MOISTURE
DIMINISHING IN THAT AREA THROUGH 10Z. UNDER SUBSIDENCE...NEGATIVE K
INDEX VALUES...AND AN 850MB THETA-E TROUGH...ANTICIPATE CONSIDERABLE
SUNSHINE TODAY AND CLEAR OR MOSTLY CLEAR CONDITIONS TONIGHT.
AREA VAD WIND PROFILES FROM THE WSR-88DS SHOWED WINDS NOT FAR OFF
THE SURFACE TO AROUND 40KT FROM THE NORTH...BUT THESE WINDS SHOULD
DIMINISH AS THE GFS FORECASTS 925MB WINDS FALLING TO NEAR 30KT VERY
EARLY TODAY AND THEN QUICKLY BELOW 20KT BY 18Z. EXPECT A FEW WIND
GUSTS NEAR 20KT DURING THE DAY BASED ON MIXING AVAILABLE VIA BUFR
SOUNDINGS. MET AND MAV MOS GUIDANCE VALUES ARE VERY CLOSE AND
GENERALLY FOLLOWED...AND THE HIGHS ARE IN FAIR AGREEMENT WITH
EXPECTED 1000-850MB THICKNESSES. HIGHS TODAY 55 TO 60. LOWS TONIGHT
WILL BE MORE VARIABLE UNDER A LIGHT WIND...MOSTLY AROUND 30 BUT SOME
MID TO UPPER 20S POSSIBLE IN THE TYPICALLY COOLER AREAS...AND A FEW
MID 30S SOUTHEAST.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 230 AM FRIDAY...
THE LOW AMPLITUDE RIDGE PROGRESSES ACROSS CENTRAL NORTH CAROLINA
SATURDAY...WITH WEAK UPPER-LEVEL TROUGHING MOVING INTO CENTRAL NORTH
CAROLINA SATURDAY NIGHT. THE MAIN DIFFERENCE BETWEEN THE NAM AND THE
GFS IS THE AMOUNT OF UPPER-LEVEL MOISTURE AND THE STRENGTH OF THE
MID-LEVEL SHORTWAVES IN THE WESTERLY FLOW ALOFT. THE GFS IS
NOTICEABLY MORE MOIST IN THE HIGH-CLOUD PORTION OF THE AIR MASS WITH
STRONGER SHORTWAVES...WHILE THE NAM IS DRIER AND WEAKER...
RESPECTIVELY. THE GFS WOULD PORTEND A GOOD INCREASE OF CIRRUS LATE
SATURDAY AND SATURDAY NIGHT ESPECIALLY ALONG AND SOUTH OF U.S. 64...
WHILE THE NAM WOULD NOTE MUCH LESS OR THINNER SUCH CLOUDS. THE
CANADIAN CLOUD COVER MODEL...USUALLY GOOD WITH HIGH-LEVEL CLOUDS...
IS MORE AKIN TO THE NAM...AND FOR THIS FORECAST WILL HAVE SKIES
PARTLY CLOUDY AT WORST LATE SATURDAY AFTERNOON AND SATURDAY NIGHT...
WITH THE HIGHER QUANTITY OF CLOUDS OVER THE SOUTHERN TWO TIERS OF
COUNTIES RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA. 1000-850MB
THICKNESSES WARM DURING THE DAY SATURDAY...AND THE SURFACE WIND
VEERS SOUTHWEST. WITH A DRY AIR MASS...THE GUIDANCE FORECAST OF A
NEARLY 30-DEGREE DIURNAL SEEMS POSSIBLE...FOR HIGHS AROUND 60.
OVERNIGHT LOWS SATURDAY NIGHT ARE A LITTLE MORE TRICKY DEPENDING ON
HOW MUCH WIND EXISTS...AS WINDS OFF OF THE SURFACE INCREASE AHEAD OF
THE NEXT DRY SURFACE FRONT. BASED ON THE POTENTIAL FOR A LITTLE
STIRRING AND THE GUIDANCE TENDENCY TO BE COOL IN THE NIGHT AHEAD OF
A SURFACE BOUNDARY...WILL SHOW A DEFINITE LEAN TOWARD THE WARMER MAV
MOS SATURDAY NIGHT. LOWS WITHIN TWO OR THREE DEGREES EITHER SIDE OF
40.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...
FOR SUNDAY THROUGH MONDAY NIGHT: QUIET AND DRY BUT TURNING COOLER.
EXPECT A FEW MID AND HIGH CLOUDS OVER THE REGION SUNDAY MORNING...
MOST MARKEDLY OVER SRN NC AS MID/HIGH CLOUDS NOW OVER NRN MEX INTO
TX SWEEP EASTWARD ACROSS THE GULF AND SOUTHEAST STATES. THE MID
LEVEL SHORTWAVE TROUGH NOW OVER MT/WY WILL DRAW IN ADDITIONAL ENERGY
FROM THE YUKON AS IT TRACKS QUICKLY EASTWARD ACROSS THE GREAT
LAKES/NORTHEAST INTO SUNDAY...SWEEPING A WEAK DRY COOL FRONT THROUGH
THE MIDATLANTIC REGION. THIS MID LEVEL TROUGH SWEEPING BY JUST TO
OUR NORTH SHOULD BRING A FEW HIGH CLOUDS ACROSS THE VA BORDER
SECTIONS...WHICH COULD BE OROGRAPHICALLY ENHANCED EARLY SUNDAY AS
SUGGESTED BY FORECAST SOUNDINGS. NEVERTHELESS...WE SHOULD SEE PLENTY
OF SUNSHINE FOR MUCH OF SUNDAY AS A GENERALLY DRY AND STABLE COLUMN
PERSISTS WITH A DOWNSLOPE WNW LOW LEVEL FLOW. 1000-850 MB
THICKNESSES ARE EXPECTED TO BE SLIGHTLY ABOVE NORMAL AHEAD OF THE
WEAK FRONT...SUPPORTING HIGHS SUNDAY OF 64-69. THE FRONT SHOULD PUSH
THROUGH THE AREA SUNDAY EVENING WITH THE COOLER SURFACE HIGH
STARTING TO BUILD IN FROM THE WEST. THE MSLP PATTERN INDICATES THAT
SURFACE WINDS SHOULD STAY UP ENOUGH IN THE EAST TO CURB RADIATIONAL
COOLING SUNDAY NIGHT...BUT WESTERN SECTIONS CLOSER TO THE HIGH
CENTER SHOULD GO NEARLY CALM. LOWS 32-40. MOSTLY SUNNY/DRY/COOL
MONDAY WITH THE SURFACE HIGH PASSING QUICKLY WEST-TO-EAST OVER NC...
AHEAD OF THE NEXT FRONT. SHOULD SEE AN INCREASE IN HIGH CLOUDS
MONDAY NIGHT WITH STRENGTHENING MID LEVEL FLOW OVER NC IN RESPONSE
TO THE STRONG VORTEX CROSSING SRN ONTARIO/QUEBEC. TEMPS A BIT BELOW
NORMAL MONDAY...HIGHS 60-65 AND LOWS 37-42.
FOR TUESDAY THROUGH THURSDAY: STILL ANTICIPATING A BREAK IN THE
QUIET WEATHER...AS A DEEP MID LEVEL SHORTWAVE TROUGH AND
ACCOMPANYING POLAR SURFACE FRONT DROP SSE TOWARD NC. SURPRISINGLY...
AGREEMENT AMONG THE MODELS IS ACTUALLY WORSE THAN IT WAS WITH
YESTERDAY`S RUNS. THE 00Z/08 GFS OVER THE LAST 4 RUNS HAS TRENDED
LESS AMPLIFIED...MORE PHASED...DRIER...AND MUCH MORE PROGRESSIVE
WITH THE MID LEVEL TROUGH SWINGING THROUGH THE EASTERN HALF OF THE
CONUS...AND IT LACKS A CLOSED LOW IN FAVOR OF A MOISTURE-STARVED MID
LEVEL TROUGH PASSAGE. THE ECMWF HAS BEEN QUITE CONSISTENT IN ITS
LAST 4 RUNS IN CLOSING OFF AN INTENSE VORTEX OVER KY/TN/SRN
APPALACHIANS LATE WED/WED NIGHT WHICH WOBBLES EASTWARD BEFORE
LIFTING OUT LATE THU... A SCENARIO ALSO HINTED AT BY THE LATEST GEFS
RUNS. THE 00Z/08 ECMWF GENERATES ABUNDANT FORCING FOR ASCENT OVER NC
AND OFF OUR COAST...FOSTERING DEVELOPMENT OF AN EXPLOSIVE COASTAL
LOW ALONG THE NEARSHORE BAROCLINIC ZONE...WHICH IN TURN SPREADS A
LOT OF WRAPAROUND PRECIP OVER THE INLAND SOUTHEAST AND MIDATLANTIC
LATE TUE NIGHT THROUGH WED EVENING. WHILE THE ECMWF HAS HAD LITTLE
SUPPORT FROM ITS ENSEMBLE MEAN...IT WOULD BE FOOLHARDY TO TOTALLY
DISCOUNT IT...BASED ON BOTH ITS CONSISTENCY AND ITS HISTORICAL
PERFORMANCE. BUT GIVEN THAT THIS IS A HIGHLY ANOMALOUS AND
CLIMATOLOGICALLY UNUSUAL SOLUTION...WILL CONTINUE WITH A
MIDDLE-OF-THE-ROAD APPROACH TO THIS EVENT...HOLDING CLOSER TO
CLIMATOLOGY THAN TO ANY EXTREME...BUT CERTAINLY THIS POSSIBLE STORM
BEARS WATCHING. APART FROM THE MODEL DIFFERENCES WITH QPF AMOUNT AND
PLACEMENT...THERE IS LITTLE DOUBT THAT THE INCOMING AIR MASS BEHIND
THE FRONT WILL BE QUITE COLD...WITH PROJECTED LOW LEVEL THICKNESSES
DROPPING TOWARD 1280 M...NEARLY 60 M BELOW NORMAL...AND BOTH THE GFS
AND ECMWF TAKING 850 MB TEMPS DOWN TO -7C TO -10C. CURRENT TEMPS
WITHIN THIS AIR MASS (NOW OVER NRN YUKON/NRN NW TERRITORIES AND THE
BEAUFORT SEA) ARE WELL BELOW ZERO FAHRENHEIT...AND THIS AIR MASS
WILL HAVE LIMITED TIME TO MODIFY BEFORE IT ARRIVES. PARTIAL
THICKNESSES FROM THE OPERATIONAL GFS AND ECMWF STILL SUGGEST A
POTENTIAL FOR WINTRY PRECIP...HOWEVER THE OPTIMAL PATTERN FOR A LOT
OF COLD AIR IN NC AND THE OPTIMAL PATTERN TO GET SUFFICIENT MOISTURE
INTO NC ARE USUALLY VERY DIFFERENT. WITH THE OPERATIONAL MODEL
SOLUTIONS SO DIVERGENT...WE CANNOT AT THIS TIME STATE A PREFERRED
SCENARIO WITH ANY CONFIDENCE. WILL STAY WITH CHANCE POPS EARLY WED
MORNING INTO THU AND WILL KEEP ANY PRECIP AS JUST COLD RAIN FOR
NOW...BUT WE WILL CLOSELY MONITOR MODEL AND OBSERVED TRENDS OVER THE
NEXT SEVERAL DAYS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 610 AM FRIDAY...
VFR CONDITIONS WILL CONTINUE THROUGH THE 12Z VALID TAF PERIOD. THE
WSR-88D VAD WIND PROFILE SHOWED A TREND TOWARD LIGHTER WINDS JUST
OFF OF THE SURFACE JUST BEFORE DAWN...AND ALTHOUGH THE LATEST AMDAR
SOUNDING FROM KRDU HAD A SLIGHTLY STRONGER WIND...THE DIMINISHING
TREND AND THE ALREADY MARGINAL LLWS CRITERIA WILL RESULT IN THE LACK
OF AN LLWS MENTION IN THE 12Z VALID TAF. VERY EARLY THIS MORNING...
THERE COULD STILL BE A NORTHWEST-TO-NORTH WIND OF 30 TO 35KT AT OR
JUST ABOVE 2000FT. FOR THE DAYLIGHT HOURS...A SURFACE NORTHWEST WIND
SHOULD CONTINUE WITH A FEW SURFACE GUSTS APPROACHING 20KT WITH
MIXING. WINDS DIMINISH QUICKLY WITH SUNSET...FALLING AOB 5KT...
POSSIBLY VEERING SLIGHTLY MORE NORTH EARLY BEFORE BECOMING GENERALLY
CALM AND VARIABLE...EXCEPT LIGHT NORTHEAST AT KFAY.
BEYOND THE 12Z VALID TAF PERIOD...VFR CONDITIONS SHOULD PREVAIL FOR
MUCH OF THE DEFINED PERIOD THROUGH TUESDAY. SURFACE WINDS BECOME
SOUTHWEST SATURDAY...THEN VEER MOSTLY WESTERLY SUNDAY. BEHIND A DRY
SURFACE FRONT...WINDS MAY VEER QUICKLY AROUND THE CLOCK MONDAY INTO
TUESDAY BEFORE BECOMING NORTHEAST AND POSSIBLY MODESTLY GUSTY
TUESDAY. DEPENDING ON THE MOISTURE AVAILABLE WITH A POSSIBLE SYSTEM
LATE IN THIS PERIOD...THERE IS THE POTENTIAL FOR SUB-VFR CLOUD
HEIGHTS...CURRENTLY A HIGHER PROBABILITY OF MVFR.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...HARTFIELD
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1003 AM CST FRI NOV 8 2013
.UPDATE...
ISSUED AT 1003 AM CST FRI NOV 8 2013
SO FAR RADAR ECHOES ARE NOT VERY IMPRESSIVE FOR THE START OF ANY
PRECIP THIS MORNING. THE BEST ECHOES ARE OVER NORTH CENTRAL ND BUT
NOT SEEING A WHOLE LOT OF GROUND TRUTH ON WEB CAMS OR METARS. 12Z
BIS SOUNDING SHOWS A DECENT DRY LAYER AROUND 825 MB...THUS ANY ICE
CRYSTALS FALLING FROM -10 TO -20 LAYER WILL LIKELY EVAPORATE.
CHALLENGE WILL BE WHEN FURTHER SATURATION OF THE COLUMN BEGINS AND
THEN P-TYPE. WILL MAKE VERY LITTLE CHANGES TO P-TYPE AT THIS
POINT...UNTIL WE GET A BETTER HANDLE ON WHAT ACTUALLY FALLS
(SOUNDINGS TRENDING MORE TOWARD RAIN). AS FAR AS POPS...WILL BLEND
IN 12Z NAM DATA WHICH FOCUSES MORE ON NORTHEAST HALF OF CWA. 12Z
NAM STILL SHOWS A POTENTIAL FOR A BAND OVER LAKE OF THE
WOODS...ROSEAU...BELTRAMI AREA...WHICH WILL BE THE BEST CHANCE FOR
SNOW IF THEY SEE MORE EVAPORATIVE COOLING BY LATE AFTN. NO SIG
CHANGES MAKE TO TEMPS/WINDS ON THIS UPDATE.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 347 AM CST FRI NOV 8 2013
CHALLENGE WILL REVOLVE AROUND THE SYSTEM TODAY...ESPECIALLY
WHERE/IF SNOWFALL COULD OCCUR. 00Z MODELS IN GENERAL
AGREEMENT...BUT STILL DIFFER WITH DETAILS. COMPARING 00Z
MODELS...THE ECMWF IS STILL THE FURTHEST SOUTH WITH THE MAIN BAND
OF PRECIP (THE 500MB WAVE IS SOUTH OF OTHER MODELS). 06Z MODEL
RUNS ARE BEGINNING TO TREND TO THE ECMWF WITH THE LOCATION OF THE
500MB HEIGHTS. WILL USE A BLEND OF THE 00Z ECMWF ALONG WITH
INCOMING HIGH RESOLUTION MODELS (RAP/HRRR/NAM12). USING A
COMBINATION OF THESE MODELS BEGINS TO CLEAR UP THE PICTURE A
LITTLE BIT.
A LEAD BAND OF 700MB WARM AIR ADVECTION WILL MOVE THROUGH THE
REGION THIS MORNING...WITH SOME PRECIP RESULTING. THE LOW LEVELS
WILL REMAIN RELATIVELY DRY WHICH WILL LIMIT COVERAGE. 925MB TEMPS
ARE ABOVE FREEZING ACROSS THE FA...AND MOST OF WHAT FALLS THIS
MORNING SHOULD BE LIQUID (MAYBE MIXED WITH SNOW DVL BASIN).
SURFACE TEMPERATURES APPEAR TO BE RISING AT A FAST ENOUGH RATE
THAT FREEZING RAIN SHOULD NOT BE A CONCERN.
AS THE MAIN UPPER WAVE MOVES THROUGH THE REGION THIS AFTERNOON
AND EVENING...A COUPLE AREAS OF PRECIP SHOULD RESULT. THE HIGHER
RESOLUTION MODELS (THAT ARE ABLE TO PICK UP ON
FRONTOGENESIS/DEFORMATION) INDICATE A BAND OF PRECIP WILL DEVELOP
ACROSS THE NORTHERN FA BY MID-AFTERNOON. ANOTHER AREA OF PRECIP
WOULD THEN DEVELOP ACROSS THE SOUTHERN FA ASSOCIATED WITH FORCING
FROM THE UPPER LOW. THUS...MOST AREAS SHOULD RECEIVE MEASURABLE
PRECIP AT SOME TIME THIS AFTERNOON OR EVENING. FOLLOWED A BLEND OF
925MB TEMPS FROM THE NAM/RAP/GFS/ECMWF FOR P-TYPE. THIS INDICATES
AREAS NEAR THE INTERNATIONAL BORDER INTO THE BEMIDJI AREA COULD BE
ALL SNOW. THE RAP IS A BIT WARMER WITH LOW LEVEL TEMPS...WHICH
WOULD MEAN MOST AREAS LIQUID...WITH ONLY ROSEAU TO BAUDETTE SNOW.
GIVEN THAT THE RAP USUALLY VERIFIES BEST WITH 925MB TEMPS...THE
WARM AIRMASS CURRENTLY IN PLACE...MUCH OF THE PRECIP WILL FALL
DURING THE DAYTIME HOURS...AND NO CLEAR ORGANIZED BANDING
POTENTIAL...WILL LIMIT SNOWFALL ACCUMULATION TO THE
ROSEAU...BAUDETTE...BEMIDJI AREA. CURRENTLY THINKING 1-2
INCHES...BUT WILL NEED TO WATCH WHERE/IF HEAVIER BANDS SET UP.
SATURDAY...COLD FRONT WILL MOVE THROUGH THE REGION. SNOW SHOWERS
POSSIBLE ACROSS NW MN WITH THE PASSAGE OF AN UPPER WAVE. WINDY
CONDITIONS LIKELY...BUT CURRENT INDICATIONS ARE THAT SPEEDS WILL
BE BELOW ADVISORY CRITERIA.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 347 AM CST FRI NOV 8 2013
SAT NIGHT-SUN NIGHT...A STRONGER COLD FRONT WILL MOVE THROUGH THE
REGION...LIKELY ON SUNDAY. AIRMASS IS DRY...BUT COULD BE SOME
ISOLATED SNOW SHOWERS. ALSO COULD BE A BRIEF PERIOD OF WINDY
CONDITIONS ALONG WITH THE FROPA.
MONDAY-THURSDAY...THE UPPER AIR PATTERN WILL BRIEFLY AMPLIFY FROM
THE NORTHWEST EARLY IN THE WEEK...WHILE AT THE SFC AN ARCTIC HIGH
DROPS SOUTHWARD. MODELS LARGELY KEEP A WEAKENING BAND OF LIGHT
SNOW ASSOCIATED WITH THE ADVANCING MID-LEVEL BAROCLINIC ZONE SOUTH
AND WEST OF THE FORECAST AREA...WITH A DRY AND UNSEASONABLY COLD
AIR MASS OVER THE REGION FOR THE START OF THE WEEK. TEMPS AT 925
MB WILL FALL TO AROUND -12 TO -15C ON MONDAY. THUS...HIGHS ON
MONDAY SHOULD NOT RISE HIGHER THAN THE 20S...WHILE MONDAY NIGHT
LIKELY WILL BE THE COLDEST NIGHT...WITH SOME SINGLE DIGIT LOW
TEMPS...AS THE SFC HIGH CENTER SINKS SOUTH ACROSS THE DAKOTAS.
HOWEVER...THE OVERALL FLOW PATTERN REMAINS PROGRESSIVE...AND MODELS
INDICATE A TRANSITION TO A FLATTER LESS AMPLIFIED FLOW FOR THE
MIDDLE AND END OF THE WEEK. AS A RESULT...TEMPS SHOULD QUICKLY
RETURN TO MORE SEASONABLE VALUES. THE UNEVENTFUL WEATHER PATTERN IS
EXPECTED TO CONTINUE THROUGH THE END OF THE PERIOD...WITH ONLY
RATHER WEAK SHORTWAVE TROUGHS PROPAGATING THROUGH THE FLOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 640 AM CST FRI NOV 8 2013
CIGS WILL GRADUALLY LOWER INTO THE AFTERNOON HOURS...BUT MOST
AREAS ARE EXPECTED TO REMAIN VFR. PRECIPITATION IS EXPECTED TO
DEVELOP DURING THE AFTERNOON HOURS...AND CIGS COULD BE MVFR WITHIN
MORE ORGANIZED BANDS OF PRECIPITATION. WIDESPREAD MVFR CIGS WILL
THEN MOVE INTO THE REGION TONIGHT BEHIND A COLD FRONT. THE
PRECIPITATION IS EXPECTED TO BE MOSTLY RAIN...WITH SNOW POSSIBLY
MIXING. KBJI HAS THE BEST CHANCE FOR MINOR ACCUMULATING SNOWFALL.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...12
SHORT TERM...TG
LONG TERM...TG/MAKOWSKI
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
640 AM CST FRI NOV 8 2013
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 347 AM CST FRI NOV 8 2013
CHALLENGE WILL REVOLVE AROUND THE SYSTEM TODAY...ESPECIALLY
WHERE/IF SNOWFALL COULD OCCUR. 00Z MODELS IN GENERAL
AGREEMENT...BUT STILL DIFFER WITH DETAILS. COMPARING 00Z
MODELS...THE ECMWF IS STILL THE FURTHEST SOUTH WITH THE MAIN BAND
OF PRECIP (THE 500MB WAVE IS SOUTH OF OTHER MODELS). 06Z MODEL
RUNS ARE BEGINNING TO TREND TO THE ECMWF WITH THE LOCATION OF THE
500MB HEIGHTS. WILL USE A BLEND OF THE 00Z ECMWF ALONG WITH
INCOMING HIGH RESOLUTION MODELS (RAP/HRRR/NAM12). USING A
COMBINATION OF THESE MODELS BEGINS TO CLEAR UP THE PICTURE A
LITTLE BIT.
A LEAD BAND OF 700MB WARM AIR ADVECTION WILL MOVE THROUGH THE
REGION THIS MORNING...WITH SOME PRECIP RESULTING. THE LOW LEVELS
WILL REMAIN RELATIVELY DRY WHICH WILL LIMIT COVERAGE. 925MB TEMPS
ARE ABOVE FREEZING ACROSS THE FA...AND MOST OF WHAT FALLS THIS
MORNING SHOULD BE LIQUID (MAYBE MIXED WITH SNOW DVL BASIN).
SURFACE TEMPERATURES APPEAR TO BE RISING AT A FAST ENOUGH RATE
THAT FREEZING RAIN SHOULD NOT BE A CONCERN.
AS THE MAIN UPPER WAVE MOVES THROUGH THE REGION THIS AFTERNOON
AND EVENING...A COUPLE AREAS OF PRECIP SHOULD RESULT. THE HIGHER
RESOLUTION MODELS (THAT ARE ABLE TO PICK UP ON
FRONTOGENESIS/DEFORMATION) INDICATE A BAND OF PRECIP WILL DEVELOP
ACROSS THE NORTHERN FA BY MID-AFTERNOON. ANOTHER AREA OF PRECIP
WOULD THEN DEVELOP ACROSS THE SOUTHERN FA ASSOCIATED WITH FORCING
FROM THE UPPER LOW. THUS...MOST AREAS SHOULD RECEIVE MEASURABLE
PRECIP AT SOME TIME THIS AFTERNOON OR EVENING. FOLLOWED A BLEND OF
925MB TEMPS FROM THE NAM/RAP/GFS/ECMWF FOR P-TYPE. THIS INDICATES
AREAS NEAR THE INTERNATIONAL BORDER INTO THE BEMIDJI AREA COULD BE
ALL SNOW. THE RAP IS A BIT WARMER WITH LOW LEVEL TEMPS...WHICH
WOULD MEAN MOST AREAS LIQUID...WITH ONLY ROSEAU TO BAUDETTE SNOW.
GIVEN THAT THE RAP USUALLY VERIFIES BEST WITH 925MB TEMPS...THE
WARM AIRMASS CURRENTLY IN PLACE...MUCH OF THE PRECIP WILL FALL
DURING THE DAYTIME HOURS...AND NO CLEAR ORGANIZED BANDING
POTENTIAL...WILL LIMIT SNOWFALL ACCUMULATION TO THE
ROSEAU...BAUDETTE...BEMIDJI AREA. CURRENTLY THINKING 1-2
INCHES...BUT WILL NEED TO WATCH WHERE/IF HEAVIER BANDS SET UP.
SATURDAY...COLD FRONT WILL MOVE THROUGH THE REGION. SNOW SHOWERS
POSSIBLE ACROSS NW MN WITH THE PASSAGE OF AN UPPER WAVE. WINDY
CONDITIONS LIKELY...BUT CURRENT INDICATIONS ARE THAT SPEEDS WILL
BE BELOW ADVISORY CRITERIA.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 347 AM CST FRI NOV 8 2013
SAT NIGHT-SUN NIGHT...A STRONGER COLD FRONT WILL MOVE THROUGH THE
REGION...LIKELY ON SUNDAY. AIRMASS IS DRY...BUT COULD BE SOME
ISOLATED SNOW SHOWERS. ALSO COULD BE A BRIEF PERIOD OF WINDY
CONDITIONS ALONG WITH THE FROPA.
MONDAY-THURSDAY...THE UPPER AIR PATTERN WILL BRIEFLY AMPLIFY FROM
THE NORTHWEST EARLY IN THE WEEK...WHILE AT THE SFC AN ARCTIC HIGH
DROPS SOUTHWARD. MODELS LARGELY KEEP A WEAKENING BAND OF LIGHT
SNOW ASSOCIATED WITH THE ADVANCING MID-LEVEL BAROCLINIC ZONE SOUTH
AND WEST OF THE FORECAST AREA...WITH A DRY AND UNSEASONABLY COLD
AIR MASS OVER THE REGION FOR THE START OF THE WEEK. TEMPS AT 925
MB WILL FALL TO AROUND -12 TO -15C ON MONDAY. THUS...HIGHS ON
MONDAY SHOULD NOT RISE HIGHER THAN THE 20S...WHILE MONDAY NIGHT
LIKELY WILL BE THE COLDEST NIGHT...WITH SOME SINGLE DIGIT LOW
TEMPS...AS THE SFC HIGH CENTER SINKS SOUTH ACROSS THE DAKOTAS.
HOWEVER...THE OVERALL FLOW PATTERN REMAINS PROGRESSIVE...AND MODELS
INDICATE A TRANSITION TO A FLATTER LESS AMPLIFIED FLOW FOR THE
MIDDLE AND END OF THE WEEK. AS A RESULT...TEMPS SHOULD QUICKLY
RETURN TO MORE SEASONABLE VALUES. THE UNEVENTFUL WEATHER PATTERN IS
EXPECTED TO CONTINUE THROUGH THE END OF THE PERIOD...WITH ONLY
RATHER WEAK SHORTWAVE TROUGHS PROPAGATING THROUGH THE FLOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 640 AM CST FRI NOV 8 2013
CIGS WILL GRADUALLY LOWER INTO THE AFTERNOON HOURS...BUT MOST
AREAS ARE EXPECTED TO REMAIN VFR. PRECIPITATION IS EXPECTED TO
DEVELOP DURING THE AFTERNOON HOURS...AND CIGS COULD BE MVFR WITHIN
MORE ORGANIZED BANDS OF PRECIPITATION. WIDESPREAD MVFR CIGS WILL
THEN MOVE INTO THE REGION TONIGHT BEHIND A COLD FRONT. THE
PRECIPITATION IS EXPECTED TO BE MOSTLY RAIN...WITH SNOW POSSIBLY
MIXING. KBJI HAS THE BEST CHANCE FOR MINOR ACCUMULATING SNOWFALL.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...TG
LONG TERM...TG/MAKOWSKI
AVIATION...TG
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
453 PM CST Fri Nov 8 2013
.UPDATE...
Issued at 453 PM CST FRI NOV 8 2013
Surface winds continue to be a bit strong at this hour but with the
rapid setting of the sun the higher end gusts that exceeded 45 MPH
will fade quickly this evening. Pressure gradient should be
sufficient to keep boundary layer winds breezy well into the overnight
hours but these speeds will be below advisory criteria, thus the
Wind Advisory has been allowed to expire.
&&
.SHORT TERM...(This Evening through Sunday Afternoon)
Issued at 238 PM CST FRI NOV 8 2013
As expected, strong winds have overspread NW MO/NE KS early this
afternoon as a SW wind shift has aligned the boundary layer
unidirectionally with unseasonably strong winds just above the surface
(50 knots @ 925mb and 65 knots @ 850mb). Current wind advisory looks
kosher and expect frequent gusts of 40 to locally 45 mph to continue
across these areas for the next 2 hours before sunset leads to
partial decoupling. A gusty character will likely persist through mid
evening before the low level jet axis shifts east with the attendant
upper trough over the northern tier states.
Southwest winds should keep temperatures in the upper 30s to mid 40s
for lows tomorrow morning, with another mild day expected Saturday.
Temperatures will be a bit cooler across far nrn MO tomorrow as some
banded mid-high cloud cover acts in concert with slightly cooler
900-800mb air edging southward.
Otherwise, dry and seasonably mild readings will continue for the
weekend with no significant impacts once we get beyond the next
several hours.
.LONG TERM...(Sunday Evening through Friday)
Issued at 238 PM CST FRI NOV 8 2013
The big concern in the medium range is focused on temperatures.
Models are in excellent agreement, and thus a high confidence
forecast, in a very anomalous arctic airmass moving southward into
the United States on Monday. 12Z guidance has maintained consistency
regarding the timing and arrival of the cold air moving into the
area Monday afternoon. As this front moves through, temperatures
should begin to fall in the afternoon, and have adjusted the diurnal
curve to represent this. Atmospheric profiles continue to indicate
a shallow layer of moisture accompanying the front southward through
the area. While the moisture may not be deep enough for widespread
rain/snow showers, wouldn`t be surprised to see sprinkles/flurries
into Monday night.
Tuesday-Thursday: The nearly +3 to +4SD high pressure area will
settle across the region Tuesday night, likely pushing overnight
lows well into the teens for some. High temperatures Tuesday,
Wednesday and even Thursday will fall some 20 degree below seasonal
normals (30s for highs, teens/20s for lows), and a review of daily
records reveals a high likelihood that average temps all three days
may fall within the top 10 coldest days in recorded history for each
date.
Friday: The cold air will linger into Friday, despite the
overrunning warm air aloft. Expect additional cloud cover and
perhaps a return to the 50s for the weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Noon)
Issued at 115 PM CST FRI NOV 8 2013
Strong south winds of 20 to 30 knots with gusts perhaps as high as
40 knots will overspread KSTJ and KMCI by 19Z, with slightly lower
speeds anticipated at the lower elevation terminal at MKC. These
winds will persist through 23Z with speeds/gusts gradually
diminishing this evening as the atmosphere decouples.
Recent RUC analysis shows the 925-850mb jet streak responsible for
the winds may be slower to shift east of the terminals than
previously anticipated. Right now I`m anticipating the boundary
layer to remain sufficiently mixed through the evening to disqualify
low level wind shear potential, but if surface speeds drop more than
anticipated the 00Z update or an amendment may be needed through
06Z.
Other than passing high clouds early this afternoon, clear skies and
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...Cutter
SHORT TERM...Bookbinder
LONG TERM...Dux
AVIATION...Bookbinder
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
239 PM CST Fri Nov 8 2013
.SHORT TERM...(This Evening through Sunday Afternoon)
Issued at 238 PM CST FRI NOV 8 2013
As expected, strong winds have overspread NW MO/NE KS early this
afternoon as a SW wind shift has aligned the boundary layer
unidirectionally with unseasonably strong winds just above the surface
(50 knots @ 925mb and 65 knots @ 850mb). Current wind advisory looks
kosher and expect frequent gusts of 40 to locally 45 mph to continue
across these areas for the next 2 hours before sunset leads to
partial decoupling. A gusty character will likely persist through mid
evening before the low level jet axis shifts east with the attendant
upper trough over the northern tier states.
Southwest winds should keep temperatures in the upper 30s to mid 40s
for lows tomorrow morning, with another mild day expected Saturday.
Temperatures will be a bit cooler across far nrn MO tomorrow as some
banded mid-high cloud cover acts in concert with slightly cooler
900-800mb air edging southward.
Otherwise, dry and seasonably mild readings will continue for the
weekend with no significant impacts once we get beyond the next
several hours.
.LONG TERM...(Sunday Evening through Friday)
Issued at 238 PM CST FRI NOV 8 2013
The big concern in the medium range is focused on temperatures.
Models are in excellent agreement, and thus a high confidence
forecast, in a very anomalous arctic airmass moving southward into
the United States on Monday. 12Z guidance has maintained consistency
regarding the timing and arrival of the cold air moving into the
area Monday afternoon. As this front moves through, temperatures
should begin to fall in the afternoon, and have adjusted the diurnal
curve to represent this. Atmospheric profiles continue to indicate
a shallow layer of moisture accompanying the front southward through
the area. While the moisture may not be deep enough for widespread
rain/snow showers, wouldn`t be surprised to see sprinkles/flurries
into Monday night.
Tuesday-Thursday: The nearly +3 to +4SD high pressure area will
settle across the region Tuesday night, likely pushing overnight
lows well into the teens for some. High temperatures Tuesday,
Wednesday and even Thursday will fall some 20 degree below seasonal
normals (30s for highs, teens/20s for lows), and a review of daily
records reveals a high likelihood that average temps all three days
may fall within the top 10 coldest days in recorded history for each
date.
Friday: The cold air will linger into Friday, despite the
overrunning warm air aloft. Expect additional cloud cover and
perhaps a return to the 50s for the weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Noon)
Issued at 115 PM CST FRI NOV 8 2013
Strong south winds of 20 to 30 knots with gusts perhaps as high as
40 knots will overspread KSTJ and KMCI by 19Z, with slightly lower
speeds anticipated at the lower elevation terminal at MKC. These
winds will persist through 23Z with speeds/gusts gradually
diminishing this evening as the atmosphere decouples.
Recent RUC analysis shows the 925-850mb jet streak responsible for
the winds may be slower to shift east of the terminals than
previously anticipated. Right now I`m anticipating the boundary
layer to remain sufficiently mixed through the evening to disqualify
low level wind shear potential, but if surface speeds drop more than
anticipated the 00Z update or an amendment may be needed through
06Z.
Other than passing high clouds early this afternoon, clear skies and
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY until 5 PM CST this afternoon FOR KSZ025-102>105.
MO...WIND ADVISORY until 5 PM CST this afternoon FOR MOZ001>006-
011>015-020>023-028>030-037.
&&
$$
SHORT TERM...Bookbinder
LONG TERM...Dux
AVIATION...Bookbinder
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
117 PM CST FRI NOV 8 2013
.SHORT TERM...(Today through Sunday)
Issued at 315 AM CST FRI NOV 8 2013
Early this morning, a surface ridge of high pressure is residing
over the area making for a cool start to the day. The surface ridge
will quickly push east into the Tennessee River Valley this morning.
As this occurs, a upper level shortwave will move into the northern
Plains forcing a cold front into the Plains states. This will
tighten the pressure gradient across the area allowing for strong
southerly winds between 20-30 MPH with gusts to 30-40 MPH today.
This will also help push temperatures above average into the upper
50s to mid 60s. Tonight the aforementioned upper level shortwave
moves into the Upper Midwest and into the Great Lakes on Saturday.
This will force a trailing weak cold front through the area on
Saturday. However, with a lack of cold air behind this front,
temperatures will continue to remain above average in the low to mid
60s. Saturday night another cool surface ridge of high pressure will
move into the area from the northern Plains. With mostly clear skies
and light winds, a good radiational cooling setup will be in place.
As such, opted for the cooler side of guidance with lows near 30
across the Iowa/Missouri border to the mid to upper 30s across
central Missouri/eastern Kansas. High pressure will continue to
reside over the area Sunday. With little mixing and a cool start to
the day expect high temperatures to return to near average in the
50s.
.LONG TERM...(Monday through Thursday)
Issued at 315 AM CST FRI NOV 8 2013
Medium range models are coming into better alignment on a highly
amplified pattern developing early next week that will bring a
significantly cold airmass into the area Monday night and Tuesday.
Both GFS and ECMWF have sped up the arrival of this airmass with
cold frontal passage now timed into the forecast area Monday
afternoon and evening. GFS is particularly fast bringing the front
in early in the day. If this model verifies then forecast highs on
Monday are much too warm, but will continue with a model blend
solution for now which incorporates the slower ECMWF.
Moisture won`t have too much time to return to the region behind
Sunday`s high pressure, but there could be enough shallow moisture
ahead of Monday`s front to squeeze out a few rain showers or even
light non-accumulating snow as the front blasts through. Cold air
advection behind the front will be strong and should keep highs on
Tuesday in the middle to upper 30s while temperatures Tuesday night
drop into the 20s. Could even see some teens Tuesday night with an
anomalously deep surface high settling in.
Upper level flow will flatten somewhat by Wednesday and Thursday as
the very deep surface high shifts east of the area. This will allow
temps to moderate somewhat but still remain several degrees below
normal.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Noon)
Issued at 115 PM CST FRI NOV 8 2013
Strong south winds of 20 to 30 knots with gusts perhaps as high as
40 knots will overspread KSTJ and KMCI by 19Z, with slightly lower
speeds anticipated at the lower elevation terminal at MKC. These
winds will persist through 23Z with speeds/gusts gradually
diminishing this evening as the atmosphere decouples.
Recent RUC analysis shows the 925-850mb jet streak responsible for
the winds may be slower to shift east of the terminals than
previously anticipated. Right now I`m anticipating the boundary
layer to remain sufficiently mixed through the evening to disqualify
low level wind shear potential, but if surface speeds drop more than
anticipated the 00Z update or an amendment may be needed through
06Z.
Other than passing high clouds early this afternoon, clear skies and
VFR conditions are expected.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...73
LONG TERM...Hawblitzel
AVIATION...Bookbinder
AREA FORECAST DISCUSSION
NWS RALEIGH NC
147 PM EST FRI NOV 08 2013
.SYNOPSIS...
HIGH PRESSURE BUILDS OVER THE AREA TODAY AND REMAINS IN PLACE
THROUGH MUCH OF THE WEEKEND. A DRY COLD FRONT MOVES THROUGH THE
REGION SUNDAY. ANOTHER HIGH THEN BUILDS OVER THE REGION FOR MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM FRIDAY...
TODAY...SURFACE HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE
WEST AS THE MID LEVEL TROUGH AXIS MOVES OFFSHORE. WATER VAPOR
IMAGERY AND LATEST UPPER AIR ANALYSIS SHOWS DRY AIR OVER THE REGION
WHICH WILL RESULT IN SUNNY SKIES TODAY. AFTER A CHILLY START THIS
MORNING...LOW LEVEL THICKNESS VALUES ARE ONLY PROGGED TO RISE TO
NEAR 1320M AND THIS SUGGESTS HIGH TEMPS IN THE MID/UPPER 50S
(WARMEST IN THE SOUTH). THERE COULD ALSO BE SOME WIND GUSTS INTO THE
MID TEENS...WHICH WOULD MAKE IT FEEL EVEN CHILLIER.
TONIGHT...LOW AMPLITUDE RIDGING ALOFT MOVES IN LATE TONIGHT...BUT
DESPITE THE WESTERLY FLOW ALOFT...THE GENERAL CONFLUENCE OF THAT
FLOW SHOULD KEEP MUCH IF NOT ALL OF THE HIGH CLOUDS OVER THE
SOUTHERN PLAINS TO THE WEST OF THE AREA...WITH MAYBE A FEW CIRRUS.
PATCH OF LOWER CLOUDS OVER PARTS OF HALIFAX AND EDGECOMBE COUNTIES
FINALLY DRIFTING SOUTHEAST IN CONCERT WITH THE RAP MODEL
SOUNDINGS...WHICH SHOW THE LOW-LEVEL MOISTURE DIMINISHING IN THAT
AREA THROUGH 10Z. UNDER SUBSIDENCE...NEGATIVE K INDEX VALUES...AND
AN 850MB THETA-E TROUGH...ANTICIPATE CLEAR OR MOSTLY CLEAR
CONDITIONS TONIGHT. LOWS TONIGHT WILL BE MORE VARIABLE UNDER A LIGHT
WIND...MOSTLY AROUND 30 BUT SOME MID TO UPPER 20S POSSIBLE IN THE
TYPICALLY COOLER AREAS...AND A FEW MID 30S SOUTHEAST.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 230 AM FRIDAY...
THE LOW AMPLITUDE RIDGE PROGRESSES ACROSS CENTRAL NORTH CAROLINA
SATURDAY...WITH WEAK UPPER-LEVEL TROUGHING MOVING INTO CENTRAL NORTH
CAROLINA SATURDAY NIGHT. THE MAIN DIFFERENCE BETWEEN THE NAM AND THE
GFS IS THE AMOUNT OF UPPER-LEVEL MOISTURE AND THE STRENGTH OF THE
MID-LEVEL SHORTWAVES IN THE WESTERLY FLOW ALOFT. THE GFS IS
NOTICEABLY MORE MOIST IN THE HIGH-CLOUD PORTION OF THE AIR MASS WITH
STRONGER SHORTWAVES...WHILE THE NAM IS DRIER AND WEAKER...
RESPECTIVELY. THE GFS WOULD PORTEND A GOOD INCREASE OF CIRRUS LATE
SATURDAY AND SATURDAY NIGHT ESPECIALLY ALONG AND SOUTH OF U.S. 64...
WHILE THE NAM WOULD NOTE MUCH LESS OR THINNER SUCH CLOUDS. THE
CANADIAN CLOUD COVER MODEL...USUALLY GOOD WITH HIGH-LEVEL CLOUDS...
IS MORE AKIN TO THE NAM...AND FOR THIS FORECAST WILL HAVE SKIES
PARTLY CLOUDY AT WORST LATE SATURDAY AFTERNOON AND SATURDAY NIGHT...
WITH THE HIGHER QUANTITY OF CLOUDS OVER THE SOUTHERN TWO TIERS OF
COUNTIES RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA. 1000-850MB
THICKNESSES WARM DURING THE DAY SATURDAY...AND THE SURFACE WIND
VEERS SOUTHWEST. WITH A DRY AIR MASS...THE GUIDANCE FORECAST OF A
NEARLY 30-DEGREE DIURNAL SEEMS POSSIBLE...FOR HIGHS AROUND 60.
OVERNIGHT LOWS SATURDAY NIGHT ARE A LITTLE MORE TRICKY DEPENDING ON
HOW MUCH WIND EXISTS...AS WINDS OFF OF THE SURFACE INCREASE AHEAD OF
THE NEXT DRY SURFACE FRONT. BASED ON THE POTENTIAL FOR A LITTLE
STIRRING AND THE GUIDANCE TENDENCY TO BE COOL IN THE NIGHT AHEAD OF
A SURFACE BOUNDARY...WILL SHOW A DEFINITE LEAN TOWARD THE WARMER MAV
MOS SATURDAY NIGHT. LOWS WITHIN TWO OR THREE DEGREES EITHER SIDE OF
40.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 150 PM FRIDAY...
SUNDAY AND SUNDAY NIGHT:
A DRY WNW FLOW ALOFT WILL PREVAIL ACROSS THE REGION ON SUNDAY...
WITH SHORTWAVE ENERGY CURRENTLY IN THE UPPER MIDWEST TRACKING EAST
THROUGH THE GREAT LAKES SAT AND INTO NEW ENGLAND ON SUN...WITH A SFC
TROUGH AXIS EXTENDING SOUTHWARD THROUGH THE MID-ATLANTIC AND
CAROLINAS LATE SAT INTO SUN. GIVEN LIGHT SOUTHWESTERLY FLOW AND
RISING LOW-LEVEL THICKNESSES IN THE PRESENCE OF SUNNY SKIES...EXPECT
HIGHS ON SUNDAY SEVERAL DEGREES WARMER THAN SAT...IN THE MID/UPPER
60S.
MONDAY AND MONDAY NIGHT:
SUBSIDENCE IN THE WAKE OF SHORTWAVE ENERGY PROGRESSING FROM NEW
ENGLAND INTO THE CANADIAN MARITIMES LATE SUN/SUN NIGHT WILL RESULT
IN PRESSURE RISES OVER THE OH VALLEY...PUSHING A DRY COLD FRONT
THROUGH THE REGION AS HIGH PRESSURE BUILDS INTO THE CAROLINAS/VA BY
12Z MON. FLOW ALOFT WILL BACK TO A MORE WESTERLY DIRECTION BY
MON/MON NIGHT AS SHORTWAVE ENERGY DIVES SE THROUGH THE UPPER MIDWEST
TOWARD THE CENTRAL MS RIVER VALLEY...ON THE WESTERN PERIPHERY OF A
POLAR VORTEX TRACKING SOUTHEAST ACROSS JAMES BAY INTO SOUTHERN
QUEBEC. IN THE WAKE OF THE DRY COLD FRONT...EXPECT HIGHS ON MON
SEVERAL DEGREES COOLER THAN SUN (AND MORE SIMILAR TO SAT)...IN THE
LOWER 60S.
TUESDAY THROUGH FRIDAY:
CONFIDENCE IN THIS PORTION OF THE FORECAST REMAINS LOWER THAN
NORMAL...WITH VAST DIFFERENCES PERSISTING AMONG THE VARIOUS LONG
RANGE MODEL GUIDANCE (GFS/ECMWF) AND GFS/ECMWF ENSEMBLE MEMBERS. THE
GFS REMAINS WEAKER AND MORE PROGRESSIVE WITH SHORTWAVE ENERGY
DIGGING SOUTHEAST THROUGH THE CENTRAL MS RIVER VALLEY INTO THE
MID-ATLANTIC/SOUTHEAST ON TUE...RESULTING IN LITTLE MORE THAN A DRY
ARCTIC FRONTAL PASSAGE ON TUE FOLLOWED BY STRONG HIGH PRESSURE
BUILDING OVER THE REGION WED-THU. THE ECMWF REMAINS STRONGER AND
LESS PROGRESSIVE WITH THE UPPER LEVEL TROUGH DIGGING INTO THE
MID-ATLANTIC/SOUTHEAST...PERHAPS DUE TO SOME DEGREE OF PHASING WITH
THE POLAR VORTEX TRACKING EAST ACROSS JAMES BAY...RESULTING IN
EXPLOSIVE CYCLONE DEVELOPMENT ALONG THE CAROLINA/MID-ATLANTIC COAST
IN THE TUE-THU PERIOD. GIVEN THAT IT IS DIFFICULT TO ASCERTAIN WHICH
MODEL IS BETTER HANDLING THE EVOLUTION OF THE UPPER LEVEL PATTERN
4-5 DAYS OUT...AND THAT THE PRECISE EVOLUTION OF THE AFOREMENTIONED
PATTERN WILL HAVE DRAMATIC IMPLICATIONS ON THE SENSIBLE WEATHER
OBSERVED ACROSS CENTRAL NC TUE-THU...WILL MAKE LITTLE CHANGE TO
PRIOR FORECASTS OTHER THAN TO FURTHER REDUCE TEMPERATURES ON WED/THU
GIVEN INCREASING CONFIDENCE THAT ARCTIC HIGH PRESSURE WILL BUILD
INTO THE REGION MID NEXT WEEK. -VINCENT
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1245 PM FRIDAY...
VFR CONDITIONS IN MOSTLY CLEAR SKIES WILL PREVAIL THROUGH THE
CURRENT TAF PERIOD AS HIGH PRESSURE DOMINATES THE WEATHER ACROSS THE
REGION. THE ONLY ISSUE MAY BE SOME ON AND OFF GUSTINESS OF THE
NORTHWESTERLY WINDS EARLY THIS AFTERNOON AS THE AFOREMENTIONED HIGH
BUILDS EAST. OTHERWISE...WINDS WILL BECOME MOSTLY CALM OVERNIGHT AND
THEN GRADUALLY BECOME MORE SOUTHERLY THROUGHOUT THE DAY ON SATURDAY
AS THE HIGH SHIFTS ACROSS THE AREA.
OUTLOOK...HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS CENTRAL NC
THROUGH EARLY NEXT WEEK...RESULTING IN A PROLONGED PERIOD OF VFR
CONDITIONS. OUR NEXT CHANCE OF ADVERSE AVIATION CONDITIONS MAY OCCUR
DURING THE MIDDLE OF NEXT WEEK AS THE NEXT SYSTEM MOVES IN...BUT
THERE IS STILL A LOT OF UNCERTAINTY WITH REGARDS TO THIS SYSTEM.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...KRR/DJF
SHORT TERM...DJF
LONG TERM...HARTFIELD
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
105 PM EST FRI NOV 08 2013
.SYNOPSIS...
HIGH PRESSURE BUILDS OVER THE AREA TODAY AND REMAINS IN PLACE
THROUGH MUCH OF THE WEEKEND. A DRY COLD FRONT MOVES THROUGH THE
REGION SUNDAY. ANOTHER HIGH THEN BUILDS OVER THE REGION FOR MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM FRIDAY...
TODAY...SURFACE HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE
WEST AS THE MID LEVEL TROUGH AXIS MOVES OFFSHORE. WATER VAPOR
IMAGERY AND LATEST UPPER AIR ANALYSIS SHOWS DRY AIR OVER THE REGION
WHICH WILL RESULT IN SUNNY SKIES TODAY. AFTER A CHILLY START THIS
MORNING...LOW LEVEL THICKNESS VALUES ARE ONLY PROGGED TO RISE TO
NEAR 1320M AND THIS SUGGESTS HIGH TEMPS IN THE MID/UPPER 50S
(WARMEST IN THE SOUTH). THERE COULD ALSO BE SOME WIND GUSTS INTO THE
MID TEENS...WHICH WOULD MAKE IT FEEL EVEN CHILLIER.
TONIGHT...LOW AMPLITUDE RIDGING ALOFT MOVES IN LATE TONIGHT...BUT
DESPITE THE WESTERLY FLOW ALOFT...THE GENERAL CONFLUENCE OF THAT
FLOW SHOULD KEEP MUCH IF NOT ALL OF THE HIGH CLOUDS OVER THE
SOUTHERN PLAINS TO THE WEST OF THE AREA...WITH MAYBE A FEW CIRRUS
EEKING INTO THE AREA. PATCH OF LOWER CLOUDS OVER PARTS OF HALIFAX
AND EDGECOMBE COUNTIES FINALLY DRIFTING SOUTHEAST IN CONCERT WITH
THE RAP MODEL SOUNDINGS...WHICH SHOW THE LOW-LEVEL MOISTURE
DIMINISHING IN THAT AREA THROUGH 10Z. UNDER SUBSIDENCE...NEGATIVE K
INDEX VALUES...AND AN 850MB THETA-E TROUGH...ANTICIPATE CLEAR OR
MOSTLY CLEAR CONDITIONS TONIGHT. LOWS TONIGHT WILL BE MORE VARIABLE
UNDER A LIGHT WIND...MOSTLY AROUND 30 BUT SOME MID TO UPPER 20S
POSSIBLE IN THE TYPICALLY COOLER AREAS...AND A FEW MID 30S SOUTHEAST.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 230 AM FRIDAY...
THE LOW AMPLITUDE RIDGE PROGRESSES ACROSS CENTRAL NORTH CAROLINA
SATURDAY...WITH WEAK UPPER-LEVEL TROUGHING MOVING INTO CENTRAL NORTH
CAROLINA SATURDAY NIGHT. THE MAIN DIFFERENCE BETWEEN THE NAM AND THE
GFS IS THE AMOUNT OF UPPER-LEVEL MOISTURE AND THE STRENGTH OF THE
MID-LEVEL SHORTWAVES IN THE WESTERLY FLOW ALOFT. THE GFS IS
NOTICEABLY MORE MOIST IN THE HIGH-CLOUD PORTION OF THE AIR MASS WITH
STRONGER SHORTWAVES...WHILE THE NAM IS DRIER AND WEAKER...
RESPECTIVELY. THE GFS WOULD PORTEND A GOOD INCREASE OF CIRRUS LATE
SATURDAY AND SATURDAY NIGHT ESPECIALLY ALONG AND SOUTH OF U.S. 64...
WHILE THE NAM WOULD NOTE MUCH LESS OR THINNER SUCH CLOUDS. THE
CANADIAN CLOUD COVER MODEL...USUALLY GOOD WITH HIGH-LEVEL CLOUDS...
IS MORE AKIN TO THE NAM...AND FOR THIS FORECAST WILL HAVE SKIES
PARTLY CLOUDY AT WORST LATE SATURDAY AFTERNOON AND SATURDAY NIGHT...
WITH THE HIGHER QUANTITY OF CLOUDS OVER THE SOUTHERN TWO TIERS OF
COUNTIES RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA. 1000-850MB
THICKNESSES WARM DURING THE DAY SATURDAY...AND THE SURFACE WIND
VEERS SOUTHWEST. WITH A DRY AIR MASS...THE GUIDANCE FORECAST OF A
NEARLY 30-DEGREE DIURNAL SEEMS POSSIBLE...FOR HIGHS AROUND 60.
OVERNIGHT LOWS SATURDAY NIGHT ARE A LITTLE MORE TRICKY DEPENDING ON
HOW MUCH WIND EXISTS...AS WINDS OFF OF THE SURFACE INCREASE AHEAD OF
THE NEXT DRY SURFACE FRONT. BASED ON THE POTENTIAL FOR A LITTLE
STIRRING AND THE GUIDANCE TENDENCY TO BE COOL IN THE NIGHT AHEAD OF
A SURFACE BOUNDARY...WILL SHOW A DEFINITE LEAN TOWARD THE WARMER MAV
MOS SATURDAY NIGHT. LOWS WITHIN TWO OR THREE DEGREES EITHER SIDE OF
40.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...
FOR SUNDAY THROUGH MONDAY NIGHT: QUIET AND DRY BUT TURNING COOLER.
EXPECT A FEW MID AND HIGH CLOUDS OVER THE REGION SUNDAY MORNING...
MOST MARKEDLY OVER SRN NC AS MID/HIGH CLOUDS NOW OVER NRN MEX INTO
TX SWEEP EASTWARD ACROSS THE GULF AND SOUTHEAST STATES. THE MID
LEVEL SHORTWAVE TROUGH NOW OVER MT/WY WILL DRAW IN ADDITIONAL ENERGY
FROM THE YUKON AS IT TRACKS QUICKLY EASTWARD ACROSS THE GREAT
LAKES/NORTHEAST INTO SUNDAY...SWEEPING A WEAK DRY COOL FRONT THROUGH
THE MIDATLANTIC REGION. THIS MID LEVEL TROUGH SWEEPING BY JUST TO
OUR NORTH SHOULD BRING A FEW HIGH CLOUDS ACROSS THE VA BORDER
SECTIONS...WHICH COULD BE OROGRAPHICALLY ENHANCED EARLY SUNDAY AS
SUGGESTED BY FORECAST SOUNDINGS. NEVERTHELESS...WE SHOULD SEE PLENTY
OF SUNSHINE FOR MUCH OF SUNDAY AS A GENERALLY DRY AND STABLE COLUMN
PERSISTS WITH A DOWNSLOPE WNW LOW LEVEL FLOW. 1000-850 MB
THICKNESSES ARE EXPECTED TO BE SLIGHTLY ABOVE NORMAL AHEAD OF THE
WEAK FRONT...SUPPORTING HIGHS SUNDAY OF 64-69. THE FRONT SHOULD PUSH
THROUGH THE AREA SUNDAY EVENING WITH THE COOLER SURFACE HIGH
STARTING TO BUILD IN FROM THE WEST. THE MSLP PATTERN INDICATES THAT
SURFACE WINDS SHOULD STAY UP ENOUGH IN THE EAST TO CURB RADIATIONAL
COOLING SUNDAY NIGHT...BUT WESTERN SECTIONS CLOSER TO THE HIGH
CENTER SHOULD GO NEARLY CALM. LOWS 32-40. MOSTLY SUNNY/DRY/COOL
MONDAY WITH THE SURFACE HIGH PASSING QUICKLY WEST-TO-EAST OVER NC...
AHEAD OF THE NEXT FRONT. SHOULD SEE AN INCREASE IN HIGH CLOUDS
MONDAY NIGHT WITH STRENGTHENING MID LEVEL FLOW OVER NC IN RESPONSE
TO THE STRONG VORTEX CROSSING SRN ONTARIO/QUEBEC. TEMPS A BIT BELOW
NORMAL MONDAY...HIGHS 60-65 AND LOWS 37-42.
FOR TUESDAY THROUGH THURSDAY: STILL ANTICIPATING A BREAK IN THE
QUIET WEATHER...AS A DEEP MID LEVEL SHORTWAVE TROUGH AND
ACCOMPANYING POLAR SURFACE FRONT DROP SSE TOWARD NC. SURPRISINGLY...
AGREEMENT AMONG THE MODELS IS ACTUALLY WORSE THAN IT WAS WITH
YESTERDAY`S RUNS. THE 00Z/08 GFS OVER THE LAST 4 RUNS HAS TRENDED
LESS AMPLIFIED...MORE PHASED...DRIER...AND MUCH MORE PROGRESSIVE
WITH THE MID LEVEL TROUGH SWINGING THROUGH THE EASTERN HALF OF THE
CONUS...AND IT LACKS A CLOSED LOW IN FAVOR OF A MOISTURE-STARVED MID
LEVEL TROUGH PASSAGE. THE ECMWF HAS BEEN QUITE CONSISTENT IN ITS
LAST 4 RUNS IN CLOSING OFF AN INTENSE VORTEX OVER KY/TN/SRN
APPALACHIANS LATE WED/WED NIGHT WHICH WOBBLES EASTWARD BEFORE
LIFTING OUT LATE THU... A SCENARIO ALSO HINTED AT BY THE LATEST GEFS
RUNS. THE 00Z/08 ECMWF GENERATES ABUNDANT FORCING FOR ASCENT OVER NC
AND OFF OUR COAST...FOSTERING DEVELOPMENT OF AN EXPLOSIVE COASTAL
LOW ALONG THE NEARSHORE BAROCLINIC ZONE...WHICH IN TURN SPREADS A
LOT OF WRAPAROUND PRECIP OVER THE INLAND SOUTHEAST AND MIDATLANTIC
LATE TUE NIGHT THROUGH WED EVENING. WHILE THE ECMWF HAS HAD LITTLE
SUPPORT FROM ITS ENSEMBLE MEAN...IT WOULD BE FOOLHARDY TO TOTALLY
DISCOUNT IT...BASED ON BOTH ITS CONSISTENCY AND ITS HISTORICAL
PERFORMANCE. BUT GIVEN THAT THIS IS A HIGHLY ANOMALOUS AND
CLIMATOLOGICALLY UNUSUAL SOLUTION...WILL CONTINUE WITH A
MIDDLE-OF-THE-ROAD APPROACH TO THIS EVENT...HOLDING CLOSER TO
CLIMATOLOGY THAN TO ANY EXTREME...BUT CERTAINLY THIS POSSIBLE STORM
BEARS WATCHING. APART FROM THE MODEL DIFFERENCES WITH QPF AMOUNT AND
PLACEMENT...THERE IS LITTLE DOUBT THAT THE INCOMING AIR MASS BEHIND
THE FRONT WILL BE QUITE COLD...WITH PROJECTED LOW LEVEL THICKNESSES
DROPPING TOWARD 1280 M...NEARLY 60 M BELOW NORMAL...AND BOTH THE GFS
AND ECMWF TAKING 850 MB TEMPS DOWN TO -7C TO -10C. CURRENT TEMPS
WITHIN THIS AIR MASS (NOW OVER NRN YUKON/NRN NW TERRITORIES AND THE
BEAUFORT SEA) ARE WELL BELOW ZERO FAHRENHEIT...AND THIS AIR MASS
WILL HAVE LIMITED TIME TO MODIFY BEFORE IT ARRIVES. PARTIAL
THICKNESSES FROM THE OPERATIONAL GFS AND ECMWF STILL SUGGEST A
POTENTIAL FOR WINTRY PRECIP...HOWEVER THE OPTIMAL PATTERN FOR A LOT
OF COLD AIR IN NC AND THE OPTIMAL PATTERN TO GET SUFFICIENT MOISTURE
INTO NC ARE USUALLY VERY DIFFERENT. WITH THE OPERATIONAL MODEL
SOLUTIONS SO DIVERGENT...WE CANNOT AT THIS TIME STATE A PREFERRED
SCENARIO WITH ANY CONFIDENCE. WILL STAY WITH CHANCE POPS EARLY WED
MORNING INTO THU AND WILL KEEP ANY PRECIP AS JUST COLD RAIN FOR
NOW...BUT WE WILL CLOSELY MONITOR MODEL AND OBSERVED TRENDS OVER THE
NEXT SEVERAL DAYS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1245 PM FRIDAY...
VFR CONDITIONS IN MOSTLY CLEAR SKIES WILL PREVAIL THROUGH THE
CURRENT TAF PERIOD AS HIGH PRESSURE DOMINATES THE WEATHER ACROSS THE
REGION. THE ONLY ISSUE MAY BE SOME ON AND OFF GUSTINESS OF THE
NORTHWESTERLY WINDS EARLY THIS AFTERNOON AS THE AFOREMENTIONED HIGH
BUILDS EAST. OTHERWISE...WINDS WILL BECOME MOSTLY CALM OVERNIGHT AND
THEN GRADUALLY BECOME MORE SOUTHERLY THROUGHOUT THE DAY ON SATURDAY
AS THE HIGH SHIFTS ACROSS THE AREA.
OUTLOOK...HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS CENTRAL NC
THROUGH EARLY NEXT WEEK...RESULTING IN A PROLONGED PERIOD OF VFR
CONDITIONS. OUR NEXT CHANCE OF ADVERSE AVIATION CONDITIONS MAY OCCUR
DURING THE MIDDLE OF NEXT WEEK AS THE NEXT SYSTEM MOVES IN...BUT
THERE IS STILL A LOT OF UNCERTAINTY WITH REGARDS TO THIS SYSTEM.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...KRR/DJF
SHORT TERM...DJF
LONG TERM...HARTFIELD
AVIATION...KRR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1252 PM CST FRI NOV 8 2013
.UPDATE...
ISSUED AT 1252 PM CST FRI NOV 8 2013
LACK OF GROUND TRUTH COUPLED WITH UNIMPRESSIVE RADAR ECHOES
CONTINUES TO BE THE CHALLENGE. THE COLUMN IS EVER SO GRADUALLY
SATURATING...BUT THE 290K ISENTROPIC SFC REALLY DOES NOT CRANK UP
THE LIFT UNTIL AFT 18Z. THEREFORE...DO SEE PRECIP CHANCES STILL
LIKELY THIS AFTN. HOWEVER TEMPS DID WARM UP MORE THAN EXPECTED
PRIOR TO ONSET OF PRECIP...SO HAVE REMOVED ANY ACCUMULATION
THROUGH 00Z. WEB CAMS ARE SHOWING WET ROADS IN NORTHEASTERN ND BUT
HARD TO TELL IF IT IS RAIN OR SNOW MELTING AS IT FALLS THROUGH THE
WARM/DRY LAYER. LIKELY SOME OF EACH. MAIN CHANGE FOR THIS UPDATE
IS TO TREND DOWNWARD POPS ACROSS THE SOUTH AND ESPECIALLY THE
WEST...ENDING PRECIP THIS EVENING QUICKER THAN INITIALLY
ADVERTISED. STILL LOOKING LIKE THERE IS A SMALL CHANCE OF UP TO AN
INCH OF ACCUMULATION IN LAKE OF THE WOODS AS COLUMN SATURATES AND
SNOW FALLS IN MY NORTHEAST...BUT THAT WILL LIKELY NOT LAST UNTIL
MORNING DUE TO STILL WARM GROUND TEMPS.
UPDATE ISSUED AT 1003 AM CST FRI NOV 8 2013
SO FAR RADAR ECHOES ARE NOT VERY IMPRESSIVE FOR THE START OF ANY
PRECIP THIS MORNING. THE BEST ECHOES ARE OVER NORTH CENTRAL ND BUT
NOT SEEING A WHOLE LOT OF GROUND TRUTH ON WEB CAMS OR METARS. 12Z
BIS SOUNDING SHOWS A DECENT DRY LAYER AROUND 825 MB...THUS ANY ICE
CRYSTALS FALLING FROM -10 TO -20 LAYER WILL LIKELY EVAPORATE.
CHALLENGE WILL BE WHEN FURTHER SATURATION OF THE COLUMN BEGINS AND
THEN P-TYPE. WILL MAKE VERY LITTLE CHANGES TO P-TYPE AT THIS
POINT...UNTIL WE GET A BETTER HANDLE ON WHAT ACTUALLY FALLS
(SOUNDINGS TRENDING MORE TOWARD RAIN). AS FAR AS POPS...WILL BLEND
IN 12Z NAM DATA WHICH FOCUSES MORE ON NORTHEAST HALF OF CWA. 12Z
NAM STILL SHOWS A POTENTIAL FOR A BAND OVER LAKE OF THE
WOODS...ROSEAU...BELTRAMI AREA...WHICH WILL BE THE BEST CHANCE FOR
SNOW IF THEY SEE MORE EVAPORATIVE COOLING BY LATE AFTN. NO SIG
CHANGES MAKE TO TEMPS/WINDS ON THIS UPDATE.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 347 AM CST FRI NOV 8 2013
CHALLENGE WILL REVOLVE AROUND THE SYSTEM TODAY...ESPECIALLY
WHERE/IF SNOWFALL COULD OCCUR. 00Z MODELS IN GENERAL
AGREEMENT...BUT STILL DIFFER WITH DETAILS. COMPARING 00Z
MODELS...THE ECMWF IS STILL THE FURTHEST SOUTH WITH THE MAIN BAND
OF PRECIP (THE 500MB WAVE IS SOUTH OF OTHER MODELS). 06Z MODEL
RUNS ARE BEGINNING TO TREND TO THE ECMWF WITH THE LOCATION OF THE
500MB HEIGHTS. WILL USE A BLEND OF THE 00Z ECMWF ALONG WITH
INCOMING HIGH RESOLUTION MODELS (RAP/HRRR/NAM12). USING A
COMBINATION OF THESE MODELS BEGINS TO CLEAR UP THE PICTURE A
LITTLE BIT.
A LEAD BAND OF 700MB WARM AIR ADVECTION WILL MOVE THROUGH THE
REGION THIS MORNING...WITH SOME PRECIP RESULTING. THE LOW LEVELS
WILL REMAIN RELATIVELY DRY WHICH WILL LIMIT COVERAGE. 925MB TEMPS
ARE ABOVE FREEZING ACROSS THE FA...AND MOST OF WHAT FALLS THIS
MORNING SHOULD BE LIQUID (MAYBE MIXED WITH SNOW DVL BASIN).
SURFACE TEMPERATURES APPEAR TO BE RISING AT A FAST ENOUGH RATE
THAT FREEZING RAIN SHOULD NOT BE A CONCERN.
AS THE MAIN UPPER WAVE MOVES THROUGH THE REGION THIS AFTERNOON
AND EVENING...A COUPLE AREAS OF PRECIP SHOULD RESULT. THE HIGHER
RESOLUTION MODELS (THAT ARE ABLE TO PICK UP ON
FRONTOGENESIS/DEFORMATION) INDICATE A BAND OF PRECIP WILL DEVELOP
ACROSS THE NORTHERN FA BY MID-AFTERNOON. ANOTHER AREA OF PRECIP
WOULD THEN DEVELOP ACROSS THE SOUTHERN FA ASSOCIATED WITH FORCING
FROM THE UPPER LOW. THUS...MOST AREAS SHOULD RECEIVE MEASURABLE
PRECIP AT SOME TIME THIS AFTERNOON OR EVENING. FOLLOWED A BLEND OF
925MB TEMPS FROM THE NAM/RAP/GFS/ECMWF FOR P-TYPE. THIS INDICATES
AREAS NEAR THE INTERNATIONAL BORDER INTO THE BEMIDJI AREA COULD BE
ALL SNOW. THE RAP IS A BIT WARMER WITH LOW LEVEL TEMPS...WHICH
WOULD MEAN MOST AREAS LIQUID...WITH ONLY ROSEAU TO BAUDETTE SNOW.
GIVEN THAT THE RAP USUALLY VERIFIES BEST WITH 925MB TEMPS...THE
WARM AIRMASS CURRENTLY IN PLACE...MUCH OF THE PRECIP WILL FALL
DURING THE DAYTIME HOURS...AND NO CLEAR ORGANIZED BANDING
POTENTIAL...WILL LIMIT SNOWFALL ACCUMULATION TO THE
ROSEAU...BAUDETTE...BEMIDJI AREA. CURRENTLY THINKING 1-2
INCHES...BUT WILL NEED TO WATCH WHERE/IF HEAVIER BANDS SET UP.
SATURDAY...COLD FRONT WILL MOVE THROUGH THE REGION. SNOW SHOWERS
POSSIBLE ACROSS NW MN WITH THE PASSAGE OF AN UPPER WAVE. WINDY
CONDITIONS LIKELY...BUT CURRENT INDICATIONS ARE THAT SPEEDS WILL
BE BELOW ADVISORY CRITERIA.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 347 AM CST FRI NOV 8 2013
SAT NIGHT-SUN NIGHT...A STRONGER COLD FRONT WILL MOVE THROUGH THE
REGION...LIKELY ON SUNDAY. AIRMASS IS DRY...BUT COULD BE SOME
ISOLATED SNOW SHOWERS. ALSO COULD BE A BRIEF PERIOD OF WINDY
CONDITIONS ALONG WITH THE FROPA.
MONDAY-THURSDAY...THE UPPER AIR PATTERN WILL BRIEFLY AMPLIFY FROM
THE NORTHWEST EARLY IN THE WEEK...WHILE AT THE SFC AN ARCTIC HIGH
DROPS SOUTHWARD. MODELS LARGELY KEEP A WEAKENING BAND OF LIGHT
SNOW ASSOCIATED WITH THE ADVANCING MID-LEVEL BAROCLINIC ZONE SOUTH
AND WEST OF THE FORECAST AREA...WITH A DRY AND UNSEASONABLY COLD
AIR MASS OVER THE REGION FOR THE START OF THE WEEK. TEMPS AT 925
MB WILL FALL TO AROUND -12 TO -15C ON MONDAY. THUS...HIGHS ON
MONDAY SHOULD NOT RISE HIGHER THAN THE 20S...WHILE MONDAY NIGHT
LIKELY WILL BE THE COLDEST NIGHT...WITH SOME SINGLE DIGIT LOW
TEMPS...AS THE SFC HIGH CENTER SINKS SOUTH ACROSS THE DAKOTAS.
HOWEVER...THE OVERALL FLOW PATTERN REMAINS PROGRESSIVE...AND MODELS
INDICATE A TRANSITION TO A FLATTER LESS AMPLIFIED FLOW FOR THE
MIDDLE AND END OF THE WEEK. AS A RESULT...TEMPS SHOULD QUICKLY
RETURN TO MORE SEASONABLE VALUES. THE UNEVENTFUL WEATHER PATTERN IS
EXPECTED TO CONTINUE THROUGH THE END OF THE PERIOD...WITH ONLY
RATHER WEAK SHORTWAVE TROUGHS PROPAGATING THROUGH THE FLOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1252 PM CST FRI NOV 8 2013
MOST LOCATIONS HAVE CIGS IN THE VFR RANGE...WITH SNOW DEVELOPING IN
THE FORECAST AREA NORTH OF THE TAF SITES. THERE WILL BE A TREND OF
INCREASING CHANCES FOR PRECIP AND DECREASING CEILINGS AS THE SFC LOW
APPROACHES FROM CENTRAL ND. FOR NOW KEPT KFAR AS MOSTLY RA WITH
-RASN OR ALL SN FURTHER NORTH. CIGS SHOULD GO DOWN TO MVFR BY THIS
EVENING WITH A FEW SITES DOWN TO IFR AT TIMES. PRECIP WILL TAPER OFF
BY EVENING AND WINDS WILL SHIFT TO THE NORTHWEST AS THE SFC LOW
MOVES EASTWARD. THE WEST-NORTHWEST WINDS WILL PICK UP TOWARDS THE
END OF THE PERIOD WITH 15 TO 25 KTS WITH HIGHER GUSTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...SPEICHER
SHORT TERM...TG
LONG TERM...TG/MAKOWSKI
AVIATION...JR