Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/18/12
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
930 PM EDT THU MAY 17 2012
.UPDATE (TONIGHT AND THURSDAY)...
01Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE SOUTHEASTERN STATES
UNDERNEATH THE INFLUENCE OF A DEEP LATE SEASON TROUGH ANCHORED BY A
CLOSED LOW NEAR THE GA/SC COAST. THE TROUGH AXIS EXTENDS SOUTHWARD
OVER THE WEST COAST OF FLORIDA AND WILL BE EXITING TO OUR EAST
DURING THE OVERNIGHT HOURS. DRIER AIR IN THE MIDDLE AND UPPER LEVELS
ENDED UP OVERSPREADING OUR REGION DURING THE PAST 24 HOURS WITH
MID-LEVEL THETA-E VALUES FALLING TO AROUND 320K. THIS PRESENTED A
FAIRLY HOSTILE ENVIRONMENT FOR DEEP CONVECTION OVER OUR ZONES. A FEW
SHOWERS/STORMS BROKE THROUGH EARLIER IN THE AFTERNOON...BUT IT TOOK
THE BETTER COLLISIONS/LOW LEVEL FOCUS FOR ASCENT OF THE WEST COAST
AND EAST COAST SEA-BREEZES TOWARD THE I-95 CORRIDOR TO PRODUCE ANY
SIGNIFICANT CONVECTION THIS EVENING. ONCE THIS CONVECTION WAS
ESTABLISHED...DIFFLUENT FLOW ALOFT ASSOCIATED WITH A 80-90KT UPPER
LEVEL JET...AND MARGINAL DEEP LAYER SHEAR WAS ENOUGH TO MAINTAIN
SOME IMPRESSIVE UPDRAFTS AND HAIL PRODUCING THUNDERSTORMS TO OUR
EAST. AS OUTFLOW FROM THESE STORMS TRIES TO COME BACK WESTWARD THE
NEXT COUPLE OF HOURS...AN ISOLATED SHOWER/STORM IS NOT IMPOSSIBLE
OVER THE FAR INTERIOR...BUT ITS APPEARING LESS AND LESS
LIKELY...ESPECIALLY NOW WITH THE LOSS OF DIURNAL HEATING. WILL ALLOW
A 20% POP TILL MIDNIGHT OVER THE FAR INTERIOR...AND THEN DROP RAIN
CHANCES.
GFS/NAM BOTH SHOW THE 700-500MB LAYER STILL FAIRLY HOSTILE TO DEEP
CONVECTION ON FRIDAY WITH THETAE VALUES OF 317-320K DURING THE
AFTERNOON/EARLY EVENING OVER MUCH OF OUR ZONES. WITH A SIMILAR LOW
LEVEL SETUP...WOULD EXPECT THE BETTER CHANCES FOR WDLY SCT SHOWERS
TO BE OVER OUR INTERIOR ZONES. EVEN MORE FAVORABLE CONDITIONS FOR
SCT STORMS WILL AGAIN EXIST OVER TOWARD THE I-95 CORRIDOR WHERE MORE
ROBUST SEA-BREEZE CONVERGENCE MAY BE ABLE TO OVERCOME THE NEGATIVE
MID-LEVELS. CURRENT GRIDS HAVE 30% POPS OVER THE INTERIOR WITH 20%
BACK TOWARD THE I-75 CORRIDOR. THIS APPEARS REASONABLE...WITH THE
20% POP CLOSER TO THE COAST LIKELY ENDING BY 4-5PM AS THE SEA-BREEZE
MOVES INLAND AND STABILIZES THE COASTAL ZONES.
&&
.AVIATION...
NO MAJOR ISSUES NEXT 24 HOURS. SOME POTENTIAL FOR MVFR VISIBILITIES
IN PATCHY FOG AROUND SUNRISE...MAINLY AROUND PGD AND LAL. CONFIDENCE
TOO LOW TO INCLUDE IN TAFS AT THIS TIME.
&&
.MARINE...
QUIET WEATHER CONDITIONS EXPECTED ON AREA WATERS WITH LIGHT WINDS
AND LOW SEAS FOR THE NEXT SEVERAL DAYS WITH NO MAJOR WEATHER
SYSTEMS IMPACTING THE AREA AND WEAK SURFACE HIGH PRESSURE RIDGING
INTO THE NORTHERN GULF THIS WEEKEND AND THROUGH NEXT WEEK.
&&
PRELIMINARY POINT TEMPS/POPS...
TPA 71 88 70 89 / 10 10 10 20
FMY 69 90 70 91 / 10 30 10 30
GIF 69 89 68 89 / 10 30 20 30
SRQ 71 87 68 88 / 10 10 10 20
BKV 62 89 63 89 / 10 10 10 20
SPG 74 86 73 88 / 10 10 10 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...JILLSON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
210 AM CDT WED MAY 16 2012
.DISCUSSION...
823 PM CDT
AS THE FRONTAL BOUNDARY CONTINUED TO SAG SOUTHEAST ACROSS
SOUTH CENTRAL WISC STRETCHING WEST THROUGH CENTRAL IA...ISOLATED
SHOWERS AND THUNDERSTORMS HAD DEVELOPED. THIS WAS FOCUSED ALONG AN
ENHANCED MID-LVL MOISTURE CONVERGENCE TONGUE...AND CONTINUED TO
PRESS SOUTHEAST TOWARDS NORTHERN IL. THE ENVIRONMENT OVER NORTHERN
IL LATE THIS AFTERNOON/EARLY EVENING...HAD INDICATED STEEP MID-LVL
LAPSE RATES DESPITE A CONTINUED RELATIVELY DRY SOUNDING. WHILE THE
MOISTURE WAS LACKING...FORCING WAS AIDING IN MAINTAINING THE
ISOLATED CONVECTION AND THE MAIN CONCERN CONTINUED TO BE STRONG TO
SEVERE WIND GUSTS. WSR-88D RADAR INDICATED EARLY THIS EVENING
VELOCITY RETURNS NEAR 40 TO AT TIMES 50 KTS. HOWEVER...THE PAST
20-30 MINUTES HAVE INDICATED A STEADY DOWNWARD TREND IN THE
REFLECTIVITY AND VELOCITY PATTERN...HOWEVER MID-LVL LAPSE RATES
HAVE REMAINED RELATIVELY STEEP.
AS WE CONTINUE TO LOSE SFC HEATING AND MOVE TOWARDS THE NOCTURNAL
HOURS...SFC INSTABILITY AND MOISTURE CONVERGENCE WILL DIMINISH.
THIS SHOULD PROVIDE A STEADY DIMINISHING TREND IN THE
PRECIPITATION AND CONVECTION THROUGHOUT THE REMAINDER OF THE
EVENING. OCCASIONAL WIND GUSTS AHEAD OF THE FRONTAL BOUNDARY COULD
STILL APPROACH 50 MPH...HOWEVER ANTICIPATE THAT THIS WILL BE LESS
FREQUENT. WINDS WILL THEN VEER TO NORTHWEST AND EVENTUALLY
NORTHERLY ON THE BACK SIDE OF THE FRONT. IN ADDITION DRY AIR WILL
RAPIDLY PUSH IN BEHIND THIS BOUNDARY...ALLOWING DEW POINTS TO FALL
MAINLY INTO THE UPR 30S TO LOWER 40S. ONCE THE CLOUDS AND PRECIP
PUSHES SOUTH/SOUTHEAST...TEMPS WILL STEADILY RADIATE INTO THE MID
40S. CLOSER TO DOWNTOWN CHICAGO AND THE URBAN HEAT ISLAND...TEMPS
SHOULD BOTTOM OUT ARND 50 DEG.
BEACHLER
//PREV DISCUSSION...
251 PM CDT
FORECAST FOCUS IN NEAR TERM REMAINS COLD FRONTAL PASSAGE THIS
EVENING AND THE POTENTIAL FOR ISOLATED/SCATTERED CONVECTION. AFTER A
MUCH COOLER DAY WEDNESDAY...A WARMING TREND BACK TO SUMMER-LIKE
TEMPERATURES AND EVENTUALLY AND INCREASING POTENTIAL FOR
THUNDERSTORMS IS EXPECTED THROUGH THE WEEKEND.
AT 19Z...SFC ANALYSIS DEPICTS COLD FRONT STRETCHING FROM NEAR GREEN
BAY WISCONSIN...TO AMES IN CENTRAL IOWA. WARM SECTOR AHEAD OF FRONT
IS CHARACTERIZED BY TEMPS IN MID-UPPER 80S FROM NORTHERN IL BACK
INTO EASTERN IA...THOUGH VERY DRY LOW LEVELS AS INDICATED BY SFC DEW
PTS GENERALLY IN THE UPPER 30S TO MID 40S. THIS NOT SURPRISING GIVEN
EXTREMELY DRY LOW-MID LEVELS SEEN IN 12Z RAOBS AT UPSTREAM AT
MPX/OAX...THOUGH THERE IS A NARROW AXIS OF SLIGHTLY HIGHER DWPTS
FROM WESTERN IL INTO NORTHEAST IL. 18Z RAP APPEARS TO HAVE A DECENT
HANDLE ON THE LOW LEVEL MOISTURE FIELD...AND REMAINS CONSISTENT IN
DEVELOPING CONVECTIVE PRECIP AHEAD OF FRONT ACROSS CNTRL/EASTERN WI
AND DEVELOPING IT SOUTHEAST INTO NORTHERN/NORTHEAST IL EARLY THIS
EVENING. DESPITE VIGOROUS MID-LEVEL SHORT WAVE DIGGING SOUTHEAST
ACROSS THE NORTHERN LAKES...STEEP LOW/MID LEVEL LAPSE RATES AND THE
APPROACH OF A RELATIVELY STRONG COLD FRONTAL BOUNDARY...DEARTH OF
LOW LEVEL MOISTURE SUGGESTS IT WILL LIKELY BE DIFFICULT TO DEVELOP
SIGNIFICANT THUNDERSTORM COVERAGE...WITH HIGH LCL/LFC AND FAIRLY
SKINNY CAPE PROFILES OF 200-300 J/KG ALOFT PER RAP SOUNDINGS. THUS
WHILE ISOLATED-SCATTERED STORMS CANT BE RULED OUT COMPLETELY WITH
FROPA EARLY THIS EVENING...CONTINUE TO SUSPECT COVERAGE WILL BE
RELATIVELY LOW AND CONDITIONAL SEVERE THREAT MINIMAL. AS NOTED
PREVIOUSLY...ANY ACTIVITY WHICH DOES DEVELOP SHOULD HAVE A FAIRLY
STRONG DIURNAL COMPONENT AND SHOULD FADE QUICKLY WITH COOLING OF
BOUNDARY LAYER BEYOND SUNSET. WILL CONTINUE TO MAINTAIN ONLY LOW
CHANCE POPS.
HIGH PRESSURE WILL THEN BUILD ACROSS THE GREAT LAKES REGION
WEDNESDAY IN THE WAKE OF THE MID-LEVEL WAVE AND COLD FRONT. MUCH
COOLER TEMPS THAN TODAY CAN BE EXPECTED...RANGING FROM AROUND 60
NEAR THE LAKE MICHIGAN SHORE TO THE LOW 70S IN THE FAR WEST/SOUTH
REACHES OF THE CWA. FLAT UPPER LEVEL RIDGE THEN SPREADS ACROSS THE
MIDWEST THURSDAY...WITH LOW LEVEL WARM ADVECTION FOCUSING ACROSS THE
UPPER MISSISSIPPI VALLEY AND ACROSS THE NORTHERN LAKES FRIDAY. AXIS
OF LOW LEVEL 40-50 KT JET KEEPS THUNDERSTORM FOCUS NORTH/NORTHWEST
OF THE CWA THROUGH THIS TIME. UPPER RIDGE STRENGTHENS OVER THE
MIDWEST INTO THE WEEKEND AS BROAD TROUGH PUSHES EAST ACROSS THE
WESTERN HALF OF THE CONUS. SOUTHEAST/SOUTH FLOW THROUGH THE PERIOD
WILL LEAD TO TEMPS GRADUALLY WARMING FROM THE 70S THURSDAY INTO THE
LOW-MID80S FRI AND MID 80S SAT. LOW LEVEL MOISTURE WILL ALSO
GRADUALLY INCREASE FROM THE WEST/SOUTHWEST OVER THE WEEKEND AS
WESTERN TROUGH AND COLD FRONT SLOWLY APPROACH. GUIDANCE HAS SLOWED
FRONTAL ARRIVAL SOMEWHAT...HOLDING OFF GREATER PRECIP/THUNDERSTORM
THREAT UNTIL SUNDAY NIGHT AND MONDAY. UPPER TROUGH THEN MOVES SLOWLY
ACROSS THE AREA EARLY NEXT WEEK WITH COOLER WEATHER AS LOW LEVEL
FLOW BECOMES NORTHERLY BEHIND THE FRONT.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
NORTHERLY WIND GUSTS OVER THE NEXT COUPLE OF HOURS.
KJB
//DISCUSSION...UPDATED 06Z...
A COLD FRONT HAS JUST PUSHED ACROSS THE TERMINALS EARLY THIS
MORNING. WINDS DIRECTLY BEHIND THIS FRONT HAVE INCREASED OUT OF THE
NORTH WITH GUSTS UP TO 30 KT. THESE STRONG WIND GUSTS WILL ONLY LAST
FOR THE NEXT 1 TO 2 HOURS AS STRONG PRESSURE RISES OVERSPREAD THE
AREA. NORTHEASTERLY FLOW WILL CONTINUE THROUGH THE DAY TODAY
AHEAD OF HIGH PRESSURE BUILDING IN FROM THE NORTH. WIND SPEEDS
SHOULD GENERALLY BE LIGHT...WITH ONLY ABOUT 10 TO 15 KT OF FLOW. THE
SURFACE HIGH PRESSURE SYSTEM WILL BUILD ACROSS THE REGION LATER THIS
EVENING...THIS WILL PROVIDE A PERIOD OF LIGHT AND VARIABLE WINDS
GRADUALLY SHIFTING TO THE SOUTHEAST.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
HIGH FOR ALL FORECAST ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY THROUGH SATURDAY...VFR.
* SUNDAY...CHANCE OF TSRA. GUSTY SOUTHWEST WINDS.
* MONDAY...CHANCE OF TSRA.
SHEA
&&
.MARINE...
208 AM CDT
A COLD FRONT HAS PUSHED SOUTH OF THE LAKE EARLY THIS MORNING. IN
THE WAKE OF THIS FRONT...NORTHERLY WINDS WINDS CONTINUE TO GUST
IN THE 25 TO 30 KT RANGE ACROSS THE SOUTHERN HALF OF LAKE
MICHIGAN. I OPTED TO ISSUE A SMALL CRAFT ADVISORY EARLIER FOR THE
ILLINOIS AND INDIANA NEAR SHORES UNTIL 15 UTC TODAY DUE TO THESE
STRONG WINDS UP TO 30 KT AND ALSO FOR THE BUILDING WAVES...WHICH
ARE EXPECTED TO BE AT OR SLIGHTLY ABOVE 4 FEET THROUGH THE MORNING
TODAY. OVERALL...I EXPECT THESE STRONG NORTHERLY WINDS GUSTS TO
SLOWLY DIMINISH LATER THIS MORNING AS SURFACE HIGH PRESSURE BUILDS
IN ACROSS THE LAKE LATER IN THE DAY. A PERIOD OF LIGHT AND
VARIABLE WINDS ARE EXPECTED TONIGHT BEFORE THE WINDS BECOME
SOUTHEASTERLY BY THURSDAY AS THE SURFACE HIGH SHIFTS EAST OF THE
LAKE. ONCE THIS OCCURS...THERE WILL BE A PROLONGED PERIOD OF
SOUTHERLY WINDS ACROSS LAKE MICHIGAN AS A LARGE AREA OF LOW
PRESSURE TAKES SHAPE ACROSS THE PLAINS. WIND SPEEDS MAY INCREASE
SOME BY THE WEEKEND...BUT OVERALL 10 TO 20 KT FLOW LOOKS TO BE THE
PRIMARY WIND SPEED.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM WEDNESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1247 AM CDT WED MAY 16 2012
.DISCUSSION...
823 PM CDT
AS THE FRONTAL BOUNDARY CONTINUED TO SAG SOUTHEAST ACROSS
SOUTH CENTRAL WISC STRETCHING WEST THROUGH CENTRAL IA...ISOLATED
SHOWERS AND THUNDERSTORMS HAD DEVELOPED. THIS WAS FOCUSED ALONG AN
ENHANCED MID-LVL MOISTURE CONVERGENCE TONGUE...AND CONTINUED TO
PRESS SOUTHEAST TOWARDS NORTHERN IL. THE ENVIRONMENT OVER NORTHERN
IL LATE THIS AFTERNOON/EARLY EVENING...HAD INDICATED STEEP MID-LVL
LAPSE RATES DESPITE A CONTINUED RELATIVELY DRY SOUNDING. WHILE THE
MOISTURE WAS LACKING...FORCING WAS AIDING IN MAINTAINING THE
ISOLATED CONVECTION AND THE MAIN CONCERN CONTINUED TO BE STRONG TO
SEVERE WIND GUSTS. WSR-88D RADAR INDICATED EARLY THIS EVENING
VELOCITY RETURNS NEAR 40 TO AT TIMES 50 KTS. HOWEVER...THE PAST
20-30 MINUTES HAVE INDICATED A STEADY DOWNWARD TREND IN THE
REFLECTIVITY AND VELOCITY PATTERN...HOWEVER MID-LVL LAPSE RATES
HAVE REMAINED RELATIVELY STEEP.
AS WE CONTINUE TO LOSE SFC HEATING AND MOVE TOWARDS THE NOCTURNAL
HOURS...SFC INSTABILITY AND MOISTURE CONVERGENCE WILL DIMINISH.
THIS SHOULD PROVIDE A STEADY DIMINISHING TREND IN THE
PRECIPITATION AND CONVECTION THROUGHOUT THE REMAINDER OF THE
EVENING. OCCASIONAL WIND GUSTS AHEAD OF THE FRONTAL BOUNDARY COULD
STILL APPROACH 50 MPH...HOWEVER ANTICIPATE THAT THIS WILL BE LESS
FREQUENT. WINDS WILL THEN VEER TO NORTHWEST AND EVENTUALLY
NORTHERLY ON THE BACK SIDE OF THE FRONT. IN ADDITION DRY AIR WILL
RAPIDLY PUSH IN BEHIND THIS BOUNDARY...ALLOWING DEW POINTS TO FALL
MAINLY INTO THE UPR 30S TO LOWER 40S. ONCE THE CLOUDS AND PRECIP
PUSHES SOUTH/SOUTHEAST...TEMPS WILL STEADILY RADIATE INTO THE MID
40S. CLOSER TO DOWNTOWN CHICAGO AND THE URBAN HEAT ISLAND...TEMPS
SHOULD BOTTOM OUT ARND 50 DEG.
BEACHLER
//PREV DISCUSSION...
251 PM CDT
FORECAST FOCUS IN NEAR TERM REMAINS COLD FRONTAL PASSAGE THIS
EVENING AND THE POTENTIAL FOR ISOLATED/SCATTERED CONVECTION. AFTER A
MUCH COOLER DAY WEDNESDAY...A WARMING TREND BACK TO SUMMER-LIKE
TEMPERATURES AND EVENTUALLY AND INCREASING POTENTIAL FOR
THUNDERSTORMS IS EXPECTED THROUGH THE WEEKEND.
AT 19Z...SFC ANALYSIS DEPICTS COLD FRONT STRETCHING FROM NEAR GREEN
BAY WISCONSIN...TO AMES IN CENTRAL IOWA. WARM SECTOR AHEAD OF FRONT
IS CHARACTERIZED BY TEMPS IN MID-UPPER 80S FROM NORTHERN IL BACK
INTO EASTERN IA...THOUGH VERY DRY LOW LEVELS AS INDICATED BY SFC DEW
PTS GENERALLY IN THE UPPER 30S TO MID 40S. THIS NOT SURPRISING GIVEN
EXTREMELY DRY LOW-MID LEVELS SEEN IN 12Z RAOBS AT UPSTREAM AT
MPX/OAX...THOUGH THERE IS A NARROW AXIS OF SLIGHTLY HIGHER DWPTS
FROM WESTERN IL INTO NORTHEAST IL. 18Z RAP APPEARS TO HAVE A DECENT
HANDLE ON THE LOW LEVEL MOISTURE FIELD...AND REMAINS CONSISTENT IN
DEVELOPING CONVECTIVE PRECIP AHEAD OF FRONT ACROSS CNTRL/EASTERN WI
AND DEVELOPING IT SOUTHEAST INTO NORTHERN/NORTHEAST IL EARLY THIS
EVENING. DESPITE VIGOROUS MID-LEVEL SHORT WAVE DIGGING SOUTHEAST
ACROSS THE NORTHERN LAKES...STEEP LOW/MID LEVEL LAPSE RATES AND THE
APPROACH OF A RELATIVELY STRONG COLD FRONTAL BOUNDARY...DEARTH OF
LOW LEVEL MOISTURE SUGGESTS IT WILL LIKELY BE DIFFICULT TO DEVELOP
SIGNIFICANT THUNDERSTORM COVERAGE...WITH HIGH LCL/LFC AND FAIRLY
SKINNY CAPE PROFILES OF 200-300 J/KG ALOFT PER RAP SOUNDINGS. THUS
WHILE ISOLATED-SCATTERED STORMS CANT BE RULED OUT COMPLETELY WITH
FROPA EARLY THIS EVENING...CONTINUE TO SUSPECT COVERAGE WILL BE
RELATIVELY LOW AND CONDITIONAL SEVERE THREAT MINIMAL. AS NOTED
PREVIOUSLY...ANY ACTIVITY WHICH DOES DEVELOP SHOULD HAVE A FAIRLY
STRONG DIURNAL COMPONENT AND SHOULD FADE QUICKLY WITH COOLING OF
BOUNDARY LAYER BEYOND SUNSET. WILL CONTINUE TO MAINTAIN ONLY LOW
CHANCE POPS.
HIGH PRESSURE WILL THEN BUILD ACROSS THE GREAT LAKES REGION
WEDNESDAY IN THE WAKE OF THE MID-LEVEL WAVE AND COLD FRONT. MUCH
COOLER TEMPS THAN TODAY CAN BE EXPECTED...RANGING FROM AROUND 60
NEAR THE LAKE MICHIGAN SHORE TO THE LOW 70S IN THE FAR WEST/SOUTH
REACHES OF THE CWA. FLAT UPPER LEVEL RIDGE THEN SPREADS ACROSS THE
MIDWEST THURSDAY...WITH LOW LEVEL WARM ADVECTION FOCUSING ACROSS THE
UPPER MISSISSIPPI VALLEY AND ACROSS THE NORTHERN LAKES FRIDAY. AXIS
OF LOW LEVEL 40-50 KT JET KEEPS THUNDERSTORM FOCUS NORTH/NORTHWEST
OF THE CWA THROUGH THIS TIME. UPPER RIDGE STRENGTHENS OVER THE
MIDWEST INTO THE WEEKEND AS BROAD TROUGH PUSHES EAST ACROSS THE
WESTERN HALF OF THE CONUS. SOUTHEAST/SOUTH FLOW THROUGH THE PERIOD
WILL LEAD TO TEMPS GRADUALLY WARMING FROM THE 70S THURSDAY INTO THE
LOW-MID80S FRI AND MID 80S SAT. LOW LEVEL MOISTURE WILL ALSO
GRADUALLY INCREASE FROM THE WEST/SOUTHWEST OVER THE WEEKEND AS
WESTERN TROUGH AND COLD FRONT SLOWLY APPROACH. GUIDANCE HAS SLOWED
FRONTAL ARRIVAL SOMEWHAT...HOLDING OFF GREATER PRECIP/THUNDERSTORM
THREAT UNTIL SUNDAY NIGHT AND MONDAY. UPPER TROUGH THEN MOVES SLOWLY
ACROSS THE AREA EARLY NEXT WEEK WITH COOLER WEATHER AS LOW LEVEL
FLOW BECOMES NORTHERLY BEHIND THE FRONT.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
NORTHERLY WIND GUSTS OVER THE NEXT COUPLE OF HOURS.
KJB
//DISCUSSION...UPDATED 06Z...
A COLD FRONT HAS JUST PUSHED ACROSS THE TERMINALS EARLY THIS
MORNING. WINDS DIRECTLY BEHIND THIS FRONT HAVE INCREASED OUT OF THE
NORTH WITH GUSTS UP TO 30 KT. THESE STRONG WIND GUSTS WILL ONLY LAST
FOR THE NEXT 1 TO 2 HOURS AS STRONG PRESSURE RISES OVERSPREAD THE
AREA. NORTHEASTERLY FLOW WILL CONTINUE THROUGH THE DAY TODAY
AHEAD OF HIGH PRESSURE BUILDING IN FROM THE NORTH. WIND SPEEDS
SHOULD GENERALLY BE LIGHT...WITH ONLY ABOUT 10 TO 15 KT OF FLOW. THE
SURFACE HIGH PRESSURE SYSTEM WILL BUILD ACROSS THE REGION LATER THIS
EVENING...THIS WILL PROVIDE A PERIOD OF LIGHT AND VARIABLE WINDS
GRADUALLY SHIFTING TO THE SOUTHEAST.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
HIGH FOR ALL FORECAST ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY THROUGH SATURDAY...VFR.
* SUNDAY...CHANCE OF TSRA. GUSTY SOUTHWEST WINDS.
* MONDAY...CHANCE OF TSRA.
SHEA
&&
.MARINE...
353 PM CDT
A COLD FRONT TRAILING BACK SOUTHWESTWARD FROM LOW PRESSURE OVER
FAR EASTERN ONTARIO BETWEEN JAMES BAY AND GEORGIAN BAY...ACROSS
THE FAR EASTERN UPPER PENINSULA OF MI...CENTRAL WI AND SE IA WILL
CONTINUE TO PUSH SE ACROSS THE UPPER GREAT LAKES AND MID MS VALLEY
THIS EVENING AS THE LOW CONTINUES TO MOVE E TO CENTRAL QUEBEC
DURING THE NIGHT. HIGH PRESSURE CENTERED OVER SOUTHERN MANITOBA
AND EXTENDING S ACROSS THE NORTHERN PLAINS WILL BUILD ACROSS THE
UPPER MIDWEST AND MID MO VALLEY OVERNIGHT BEHIND THE COLD FRONT.
COLD AIR ADVECTION AND A SIGNIFICANT 3 HR PRESSURE RISE CENTER OF
5-6 MB WAS MOVING SE ACROSS CENTRAL LAKE SUPERIOR AND THE U.P. OF
MI GENERATING SOME NW GUSTS TO AROUND 30 KT BEHIND THE COLD FRONT.
THIS PRESSURE RISE CENTER IS EXPECTED TO SWING ACROSS NORTHERN
LAKE MI THIS EVE CAUSING SOME GUSTY NW AND N WINDS MAINLY ON THE N
PORTION OF THE LAKE.
HIGH PRESSURE CENTERED OVER SOUTHERN MANITOBA AND EXTENDING S
ACROSS THE NORTHERN PLAINS WILL BUILD ACROSS THE UPPER MIDWEST AND
MID MO VALLEY OVERNIGHT BEHIND THE COLD FRONT WITH THE PRESSURE
GRADIENT OVER LAKE MI GRADUALLY WEAKENING AND THE RESULTANT WINDS
SLACKING. THIS HIGH THEN MOVES E OVER THE UPPER GREAT LAKES DURING
WED BRINGING LIGHTER WINDS TO THE LAKE. AS THE HIGH SHIFTS FURTHER
E TO THE LOWER GREAT LAKES DURING THU SE WINDS WILL START TO
SLOWLY INCREASE THU NIGHT AND FRI AS LOW PRESSURE MOVES E OVER THE
CENTRAL PLAINS.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM WEDNESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
150 AM EDT WED MAY 16 2012
.AVIATION...
HIRES GUIDANCE OUT TO LUNCH THIS EVENING WITH WHOPPING TEMP AND
DEWPOINT ERRORS RESULTING IN POOR HANDLING OF RESIDUAL CONVECTION
ALONG COLD FRONT MOVING THROUGH KSBN AT THIS TIME. RADAR SHOWING A
SLIGHT FLARE UP ALONG ELEVATED THETA E GRADIENT AND APPROACHING
850MB TROUGH. CONVECTION REMAINS SPOTTY AND CONFINED TO KSBN AREA
FOR NEXT HOUR TO TWO AT MOST SO ACCOUNTED FOR VIS RESTRICTION DURING
THIS PERIOD. UNLESS ADDITIONAL DEVELOPMENT TAKES PLACE DO NOT EXPECT
PCPN TO REACH KFWA. WINDS BECOME NORTH TO NORTHEAST BEHIND FRONT
WITH DRYING EXPECTED TOWARD DAYBREAK. SHOULD SEE MID LEVEL CLOUDS
DECREASE FROM WEST TO EAST TOWARD SUNRISE AND SHORTLY AFTER.
&&
.UPDATE...
HIRES GUIDANCE SHOWING SERIOUS ERRORS WITH TEMPS AND DEW POINTS THIS
EVENING ACROSS THE AREA. RUC...HRRR...NAM12...LOCAL WRF...SREF...ALL
TOO COOL WITH HOURLY TEMPS BY 7 TO 12 DEGREES AT 05Z AND ALSO
STRUGGLING WITH EXTRAORDINARY DEW POINT DISCONTINUITIES ACROSS THE
CWA. EARLIER MIXING AHEAD OF FRONT ALLOWED DRIER AIR TO WORK TO
SURFACE WHILE MOISTURE HAS BEEN POOLING IMMEDIATELY ALONG FRONT THIS
EVENING AND NOW DRIER AIR IS WORKING IN FROM NORTH IN WAKE OF COLD
FRONT. TRIED TO ADJUST GRIDS TO REFLECT THIS WITH COOLING AND DRYING
THROUGH THE NIGHT. THE WARMER TEMPS AND POOLING MOISTURE HAS ALLOWED
A POCKET OF CONVECTION TO PERSIST NEAR KSBN WITH A SLOW DRIFT EAST.
ADJUSTED GRIDS SLIGHTLY TO ACCOUNT FOR THIS FOR A FEW MORE HOURS
OVERNIGHT. REMAINDER OF FORECAST UNCHANGED AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 430 PM EDT TUE MAY 15 2012/
SHORT TERM.../TONIGHT-WED NGT/
CDFNT MOVG ACROSS WI/IA THIS AFTN WILL MOVE SE ACROSS OUR CWA
TONIGHT. BKN HIGH BASED CU AND ISOLATED LIGHTNING STRIKES ALONG
FRONT OVER WI/IA ATTM. SFC OBS AND 12Z UPR AIR ANALYSIS SUGGESTS
LATEST NCEP MODELS CONT TO BE TOO MOIST IN LOW LEVELS... THUS
CONFIDENCE IN BKN LINE OF SHOWERS/TSTMS DVLPG FROM MI-SE IA BY 00Z
AS DEPICTED BY LATEST 4KM SPC WRF IS LOW. HRRR INDICATING
CONSIDERABLY LOWER CHC OF CONVECTION REACHING OUR AREA AND APPEARS
TO BE HANDLING THE SFC DWPTS AHEAD OF THE FRONT A LITTLE BETTER. IN
EITHER CASE... ANY SHOWERS/TSTMS WHICH DEVELOP ALONG FRONT LATE
THIS AFTN/EARLY EVE SHOULD BE IN A WKNG/DISSIPATING STAGE UPON
REACHING OUR CWA GIVEN DRY AIRMASS IN PLACE AND DIURNAL
STABILIZATION. ALTHOUGH CONFIDENCE LOW IN CONVECTION REACHING OUR
AREA... FELT GOING LOW CHC OF TSTMS TONIGHT WORTH LEAVING IN FCST
ATTM. GIVEN STEEP LAPSE RATES ABOVE DVLPG SHALLOW NOCTURNAL SFC
BASED INVERSION... POTENTIAL FOR SOME GUSTY WINDS IF CONVECTION
DOES REACH OUR CWA.
HIGH PRESSURE BUILDING INTO THE AREA BEHIND THE FRONT WED WILL
RESULT IN CLEARING SKIES. FAIRLY STRONG CAA SHOULD HOLD TEMPS DOWN
ABOUT 10F FROM TODAYS READINGS DESPITE SUNNY SKIES MOST OF THE DAY.
WITH HIGH MOVG OVERHEAD WED NGT LIGHT WINDS AND DRY AIRMASS WILL
RESULT IN GOOD RADIATIONAL COOLING WITH LOWS IN THE L-M40S ACROSS
THE AREA.
LONG TERM...
PROGRESSIVE PATTN ALOFT CONTS TO HOLD SWAY THIS PD. LEAD SW TROUGH
OVR SRN ON THIS AFTN WILL RAPIDLY DRIVE EWD UP THROUGH THE ST LAW
VALLEY THU AS SFC RIDGING SHIFTS EWD W/ROBUST WAA DVLPG DURING THE
DAY. MEXMOS APPROXIMATION STILL HOLDS AND SEE NO REASON TO CHG
ANYTHING.
AFT THAT...SIG UPR RIDGING DVLPS EWD OF WRN US TROUGHING AND
INTENSIFIES ACRS THE MID ATL COAST THIS WEEKEND. THERMAL RIDGE
INBTWN WILL BE QUITE WARM FOR MID MAY STANDARDS WITH LOW-MID 80S
XPCD FRI-SUN. EJECTING WRN TROUGH SAT PROGGED TO QUICKLY DEAMPLIFY
EWD MON IN RESPONSE TO DOWNSTREAM UPR RIDGING AND RENEWED FOCUS ON A
MORE SIG WAVE TRAIN ENTERING NWPAC/SW CANADA. IN ADDN...CONTD
SUGGESTION OF A TROPICAL DISTURBANCE OVR THE WRN CARIBBEAN WILL
ELIMINATE ANY SIG GOMEX MSTR RTN. GIVEN CONTD POOR MODEL HANDLING OF
BNDRY LYR MSTR AND XPCD WKNG FNTL SYS...WILL SLASH GOING POPS LWR
MON/MON NIGHT. REMAINDER ON TRACK.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 4 PM EDT
WEDNESDAY FOR LMZ043-046.
&&
$$
SHORT TERM...JT
LONG TERM...T
AVIATION...LASHLEY
UPDATE...LASHLEY
AREA FORECAST DISCUSSION
NWS GOODLAND KS
449 PM MDT WED MAY 16 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 150 PM MDT WED MAY 16 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW SHORTWAVE RIDGE
OVER WESTERN KS BEGINNING TO BREAK DOWN AS SHORTWAVE TROUGH OVER
GREAT BASIN CONTINUES TO MOVE EAST INTO THE CENTRAL ROCKIES. TIGHT
GRADIENT CURRENTLY IN PLACE ACROSS CWA NO EASTERN EXTENT OF LEE
TROUGH HAS LED TO BREEZY CONDITIONS ACROSS THE AREA...WITH WINDS
GUSTING AROUND 30KT AT SEVERAL LOCATIONS. A WARM FRONT JUST
SOUTHWEST OF GOODLAND LIFTING TO THE NORTHEAST. WEST OF THIS FRONT
RH VALUES HAVE DROPPED TO 15% OR LOWER. WITH SEVERAL LOCATIONS
ALREADY WITHIN RED FLAG CRITERIA...PLAN ON KEEPING RFW IN PLACE
THROUGH EXPIRATION (02Z).
SHORTWAVE TROUGH WILL CONTINUE TO MOVE EAST WITH LARGE SCALE ASCENT
SPREADING INTO EASTERN COLORADO. RADAR RETURNS ALREADY SHOWING
SHOWERS/THUNDERSTORMS ALONG FRONT RANGE...WITH ACTIVITY GENERALLY
MOVING FROM THE SOUTH TO NORTH. LATEST RUC/HRRR SHOW THIS ACTIVITY
REMAINING JUST EAST OF THE CWA. WITH LARGE SCALE ASCENT STILL
EXPECTED TO OVERSPREAD THE CWA...AND THE CLOSE PROXIMITY OF
ACTIVITY...I DECIDED TO LEAVE ISOLATED THUNDERSTORMS IN FORECAST
THIS EVENING.
SHORTWAVE TROUGH AXIS CURRENTLY PROGGED TO MOVE EAST ACROSS WESTERN
KS. GUIDANCE IN GENERAL AGREEMENT ON TIMING...HOWEVER STRENGTH AND
POSITION OF SHORTWAVE ARE STILL ISSUES...WITH KEEPING OUR CWA
DRY...AND OTHER GUIDANCE FAVORING THE SOUTH AND EAST LATE THURSDAY
AFTERNOON. WITH INSTABILITY/LARGE SCALE ASCENT ACROSS THE CWA
THURSDAY...SLIGHT CHANCE POPS FROM PREVIOUS FORECAST SEEMED
REASONABLE. TIGHT SURFACE GRADIENT WILL REMAIN IN PLACE OVER EASTERN
PARTS OF CWA...WITH NAM/GFS BL WINDS APPROACHING ADVISORY CRITERIA
FOR A PERIOD OF TIME THURSDAY AFTERNOON. CONFIDENCE IS NOT THERE
THAT ADVISORY CRITERIA WINDS WILL LAST 3HR...SO NO HAZARD PLANNED.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 248 PM MDT WED MAY 16 2012
THURSDAY EVENING THE SHORT WAVE TROUGH WILL CONTINUE TO MOVE EAST
ACROSS THE AREA. LATEST GUIDANCE DISAGREES WITH THE LOCATION OF THE
SHORT WAVE TROUGH DURING THE EVENING...WITH THE GFS SHIFTING THE
TROUGH FURTHER NORTH WHILE THE NAM HAS KEPT THE TROUGH OVER THE
SOUTHERN PART OF THE AREA. WITH MODELS NOT BEING CONSISTANT WITH
THE PLACEMENT OF THE SHORT WAVE TROUGH...WILL EXPAND THE SLIGHT
CHANCES TO INCLUDE THE ENTIRE AREA EAST OF THE COLORADO LINE. WITH
A DEEP WELL MIXED LAYER IN PLACE OVER THE AREA...STRONG DOWN BURST
WINDS WILL BE POSSIBLE WITH ANY THUNDERSTORM THAT DEVELOPS DURING
THE EARLY EVENING. THE SHORT WAVE TROUGH AND MID LEVEL CAPE WILL
EXIT THE AREA AROUND MIDNIGHT BRINGING ANY CHANCE FOR PRECIPITATION
TO AN END.
FRIDAY A DRY LINE SETS UP OVER THE CENTRAL PART OF THE AREA. DURING THE
MID TO LATE AFTERNOON A SHORT WAVE TROUGH MOVES OVER THE DRY LINE.
POINT SOUNDINGS FOR THE AREA SHOW THE ENVIRONMENT NEARING SATURATION
AROUND THE 500MB LEVEL ON UP...SO AM THINKING THE STORM DEVELOPMENT
WILL BE TIED TO THE LOCATION OF THE 500MB LIFT. HOWEVER CANNOT RULE
OUT ENOUGH CONVERGENCE OCCURRING OVER THE DRY LINE FOR A STORM OR TWO
TO INITIATION...SO HAVE PLACED SLIGHT CHANCES ALONG THE DRY LINE WITH
FOCUS ON THE BETTER AREA OF 500MB LIFT DURING THE LATE
AFTERNOON. WITH THE DEEP WELL MIXED ENVIRONMENT OVER THE
AREA...STRONG DOWN BURST WINDS ARE POSSIBLE WITH ANY STORM THAT
DEVELOPS DURING THE EARLY EVENING. THE SHORT WAVE TROUGH EXITS THE
AREA AROUND MIDNIGHT...BRINGING PRECIPITATION CHANCES TO AN END.
SOUTH WINDS WILL INCREASE DURING THE LATE MORNING AND AFTERNOON AS
STRONGER WINDS ABOVE THE SURFACE MIX DOWN TO THE GROUND. THE
SURFACE PRESSURE GRADIENT WILL ALSO TIGHTEN THROUGH THE AFTERNOON
AHEAD OF THE COLD FRONT THAT WILL MOVE THROUGH DURING THE OVERNIGHT
HOURS. WINDS WILL PEAK DURING THE LATE AFTERNOON...WITH GUSTS UP TO
40 MPH POSSIBLE. THE WINDS WILL EASE SOME DURING THEN EVENING AS
MIXING CEASES...BUT WILL STILL BE GUSTY DUE TO THE TIGHT PRESSURE
GRADIENT IN PLACE AHEAD OF THE COLD FRONT.
DURING THE OVERNIGHT HOURS A COLD FRONT WILL MOVE INTO THE AREA FROM
THE NORTHWEST. LATEST CROSS SECTIONS SHOW THE LIFT TO BE SITUATED
AHEAD OF THE FRONT IN THE DRIER AIR. WILL BE KEEPING THE FRONTAL
PASSAGE FOR THE OVERNIGHT PERIOD DRY AS A RESULT.
THE SATURDAY THROUGH FRIDAY PERIOD WILL START OFF WITH PRECIPITATION
CHANCES ACROSS MOST OF THE AREA SATURDAY...FOLLOWING A SHORT WAVE
TROUGH AND COLD FRONT THAT WILL MOVE THROUGH THE AREA DURING THE
DAY. BULK OF THE MOISTURE WILL BE OVER THE NORTHERN HALF OF THE
AREA...CAUSING PRECIPITATION CHANCES TO QUICKLY DECREASE OVER THE
SOUTHERN PART OF THE AREA THAT WILL BE IN THE DRIER AIR. BEHIND THE
FRONT WINDS WILL BE GUSTY...BUT SHOULD DECLINE THROUGH THE DAY AS
THE FRONT MOVES FURTHER SOUTH.
SATURDAY EVENING PRECIPITATION CHANCES CONTINUE AS THE SHORT WAVE
TROUGH MOVES ACROSS THE EASTERN PART OF THE AREA. MODELS HAVE A
SECOND SHORT WAVE TROUGH FOLLOWING THE FIRST ONE OVER THE WESTERN
PART OF THE AREA. AM NOT TOO CONFIDENT THERE WILL BE MUCH MOISTURE
FOR THE SECOND SHORT WAVE TO WORK WITH...BUT KEPT IN SLIGHT CHANCES
FOR THE REST OF THE AREA TO STAY CONSISTANT WITH NEIGHBORS.
PRECIPITATION CHANCES RETURN WEDNESDAY TO THE EASTERN PART OF THE
AREA AS ANOTHER SHORT WAVE TROUGH MOVES ACROSS THE AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 449 PM MDT WED MAY 16 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT BOTH
TERMINALS. A LEE TROUGH WILL CONTINUE TO BE LOCATED OVER EASTERN
COLORADO TONIGHT AND SLOWLY MOVE INTO WESTERN KANSAS THURSDAY.
WINDS WILL CONTINUE TO BE GUSTY THROUGH THE OVERNIGHT HOURS WITH
GUSTS OF 18-20 KNOTS POSSIBLE. LOW LEVEL JET WILL STRENGTHEN
OVERNIGHT WITH LLWS POSSIBLE AT BOTH TERMINALS. HOWEVER...WITH
SURFACE WINDS GUSTY OVERNIGHT...FEEL THAT WILL NOT MEET LLWS
CRITERIA SO WILL KEEP OUT OF SIGHT ATTM AND CONTINUE TO WATCH
THROUGH THE EVENING HOURS. WINDS WILL BE GUSTY ON THURSDAY AND
MID LEVEL CLOUDS WILL INCREASE AS A DISTURBANCE MOVES INTO THE
REGION. ISOLATED THUNDERSTORMS ARE POSSIBLE THURSDAY BUT
TIMING/COVERAGE IS UNCERTAIN SO WILL KEEP OUT OF TAFS.
&&
.FIRE WEATHER...
ISSUED AT 248 PM MDT WED MAY 16 2012
FRIDAY AFTERNOON SOUTH WINDS WILL STRENGTHEN...WITH GUSTS UP TO 40
MPH ACROSS THE AREA. RELATIVE HUMIDITIES WILL FALL INTO THE 10 TO
20 PERCENT RANGE DURING THE AFTERNOON FOR LOCATIONS WEST OF A
MCCOOK TO GOVE LINE...LEADING TO HAZARDOUS FIRE WEATHER
CONDITIONS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING UNTIL 8 PM MDT /9 PM CDT/ THIS EVENING FOR
KSZ001-013-027.
CO...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ252>254.
NE...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR NEZ079.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...BAS
FIRE WEATHER...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
251 PM MDT WED MAY 16 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 150 PM MDT WED MAY 16 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW SHORTWAVE RIDGE
OVER WESTERN KS BEGINNING TO BREAK DOWN AS SHORTWAVE TROUGH OVER
GREAT BASIN CONTINUES TO MOVE EAST INTO THE CENTRAL ROCKIES. TIGHT
GRADIENT CURRENTLY IN PLACE ACROSS CWA NO EASTERN EXTENT OF LEE
TROUGH HAS LED TO BREEZY CONDITIONS ACROSS THE AREA...WITH WINDS
GUSTING AROUND 30KT AT SEVERAL LOCATIONS. A WARM FRONT JUST
SOUTHWEST OF GOODLAND LIFTING TO THE NORTHEAST. WEST OF THIS FRONT
RH VALUES HAVE DROPPED TO 15% OR LOWER. WITH SEVERAL LOCATIONS
ALREADY WITHIN RED FLAG CRITERIA...PLAN ON KEEPING RFW IN PLACE
THROUGH EXPIRATION (02Z).
SHORTWAVE TROUGH WILL CONTINUE TO MOVE EAST WITH LARGE SCALE ASCENT
SPREADING INTO EASTERN COLORADO. RADAR RETURNS ALREADY SHOWING
SHOWERS/THUNDERSTORMS ALONG FRONT RANGE...WITH ACTIVITY GENERALLY
MOVING FROM THE SOUTH TO NORTH. LATEST RUC/HRRR SHOW THIS ACTIVITY
REMAINING JUST EAST OF THE CWA. WITH LARGE SCALE ASCENT STILL
EXPECTED TO OVERSPREAD THE CWA...AND THE CLOSE PROXIMITY OF
ACTIVITY...I DECIDED TO LEAVE ISOLATED THUNDERSTORMS IN FORECAST
THIS EVENING.
SHORTWAVE TROUGH AXIS CURRENTLY PROGGED TO MOVE EAST ACROSS WESTERN
KS. GUIDANCE IN GENERAL AGREEMENT ON TIMING...HOWEVER STRENGTH AND
POSITION OF SHORTWAVE ARE STILL ISSUES...WITH KEEPING OUR CWA
DRY...AND OTHER GUIDANCE FAVORING THE SOUTH AND EAST LATE THURSDAY
AFTERNOON. WITH INSTABILITY/LARGE SCALE ASCENT ACROSS THE CWA
THURSDAY...SLIGHT CHANCE POPS FROM PREVIOUS FORECAST SEEMED
REASONABLE. TIGHT SURFACE GRADIENT WILL REMAIN IN PLACE OVER EASTERN
PARTS OF CWA...WITH NAM/GFS BL WINDS APPROACHING ADVISORY CRITERIA
FOR A PERIOD OF TIME THURSDAY AFTERNOON. CONFIDENCE IS NOT THERE
THAT ADVISORY CRITERIA WINDS WILL LAST 3HR...SO NO HAZARD PLANNED.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 248 PM MDT WED MAY 16 2012
THURSDAY EVENING THE SHORT WAVE TROUGH WILL CONTINUE TO MOVE EAST
ACROSS THE AREA. LATEST GUIDANCE DISAGREES WITH THE LOCATION OF THE
SHORT WAVE TROUGH DURING THE EVENING...WITH THE GFS SHIFTING THE
TROUGH FURTHER NORTH WHILE THE NAM HAS KEPT THE TROUGH OVER THE
SOUTHERN PART OF THE AREA. WITH MODELS NOT BEING CONSISTANT WITH
THE PLACEMENT OF THE SHORT WAVE TROUGH...WILL EXPAND THE SLIGHT
CHANCES TO INCLUDE THE ENTIRE AREA EAST OF THE COLORADO LINE. WITH
A DEEP WELL MIXED LAYER IN PLACE OVER THE AREA...STRONG DOWN BURST
WINDS WILL BE POSSIBLE WITH ANY THUNDERSTORM THAT DEVELOPS DURING
THE EARLY EVENING. THE SHORT WAVE TROUGH AND MID LEVEL CAPE WILL
EXIT THE AREA AROUND MIDNIGHT BRINGING ANY CHANCE FOR PRECIPITATION
TO AN END.
FRIDAY A DRY LINE SETS UP OVER THE CENTRAL PART OF THE AREA. DURING THE
MID TO LATE AFTERNOON A SHORT WAVE TROUGH MOVES OVER THE DRY LINE.
POINT SOUNDINGS FOR THE AREA SHOW THE ENVIRONMENT NEARING SATURATION
AROUND THE 500MB LEVEL ON UP...SO AM THINKING THE STORM DEVELOPMENT
WILL BE TIED TO THE LOCATION OF THE 500MB LIFT. HOWEVER CANNOT RULE
OUT ENOUGH CONVERGENCE OCCURRING OVER THE DRY LINE FOR A STORM OR TWO
TO INITIATION...SO HAVE PLACED SLIGHT CHANCES ALONG THE DRY LINE WITH
FOCUS ON THE BETTER AREA OF 500MB LIFT DURING THE LATE
AFTERNOON. WITH THE DEEP WELL MIXED ENVIRONMENT OVER THE
AREA...STRONG DOWN BURST WINDS ARE POSSIBLE WITH ANY STORM THAT
DEVELOPS DURING THE EARLY EVENING. THE SHORT WAVE TROUGH EXITS THE
AREA AROUND MIDNIGHT...BRINGING PRECIPITATION CHANCES TO AN END.
SOUTH WINDS WILL INCREASE DURING THE LATE MORNING AND AFTERNOON AS
STRONGER WINDS ABOVE THE SURFACE MIX DOWN TO THE GROUND. THE
SURFACE PRESSURE GRADIENT WILL ALSO TIGHTEN THROUGH THE AFTERNOON
AHEAD OF THE COLD FRONT THAT WILL MOVE THROUGH DURING THE OVERNIGHT
HOURS. WINDS WILL PEAK DURING THE LATE AFTERNOON...WITH GUSTS UP TO
40 MPH POSSIBLE. THE WINDS WILL EASE SOME DURING THEN EVENING AS
MIXING CEASES...BUT WILL STILL BE GUSTY DUE TO THE TIGHT PRESSURE
GRADIENT IN PLACE AHEAD OF THE COLD FRONT.
DURING THE OVERNIGHT HOURS A COLD FRONT WILL MOVE INTO THE AREA FROM
THE NORTHWEST. LATEST CROSS SECTIONS SHOW THE LIFT TO BE SITUATED
AHEAD OF THE FRONT IN THE DRIER AIR. WILL BE KEEPING THE FRONTAL
PASSAGE FOR THE OVERNIGHT PERIOD DRY AS A RESULT.
THE SATURDAY THROUGH FRIDAY PERIOD WILL START OFF WITH PRECIPITATION
CHANCES ACROSS MOST OF THE AREA SATURDAY...FOLLOWING A SHORT WAVE
TROUGH AND COLD FRONT THAT WILL MOVE THROUGH THE AREA DURING THE
DAY. BULK OF THE MOISTURE WILL BE OVER THE NORTHERN HALF OF THE
AREA...CAUSING PRECIPITATION CHANCES TO QUICKLY DECREASE OVER THE
SOUTHERN PART OF THE AREA THAT WILL BE IN THE DRIER AIR. BEHIND THE
FRONT WINDS WILL BE GUSTY...BUT SHOULD DECLINE THROUGH THE DAY AS
THE FRONT MOVES FURTHER SOUTH.
SATURDAY EVENING PRECIPITATION CHANCES CONTINUE AS THE SHORT WAVE
TROUGH MOVES ACROSS THE EASTERN PART OF THE AREA. MODELS HAVE A
SECOND SHORT WAVE TROUGH FOLLOWING THE FIRST ONE OVER THE WESTERN
PART OF THE AREA. AM NOT TOO CONFIDENT THERE WILL BE MUCH MOISTURE
FOR THE SECOND SHORT WAVE TO WORK WITH...BUT KEPT IN SLIGHT CHANCES
FOR THE REST OF THE AREA TO STAY CONSISTANT WITH NEIGHBORS.
PRECIPITATION CHANCES RETURN WEDNESDAY TO THE EASTERN PART OF THE
AREA AS ANOTHER SHORT WAVE TROUGH MOVES ACROSS THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1217 PM MDT WED MAY 16 2012
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD AT BOTH KGLD AND
KMCK. GUSTY WINDS EXPECTED THROUGH MOST OF THE TAF PERIOD AT BOTH
SITES WITH STRONGEST WINDS THIS AFTERNOON 25-30KT. WINDS SHOULD
DECREASE SLIGHTLY AFTER SUNSET...THOUGH THEY WILL REMAIN GUSTY AT
BOTH TERMINALS THROUGH THURSDAY MORNING AS UPPER LEVEL DISTURBANCE
MOVES EAST. THERE IS A SMALL CHANCE FOR A THUNDERSTORM AT KGLD THIS
AFTERNOON/EVENING AND AT BOTH KGLD AND KMCK THURSDAY AFTERNOON.
COVERAGE WILL BE VERY LIMITED...SO LEFT MENTION OUT OF TAFS.
&&
.FIRE WEATHER...
ISSUED AT 248 PM MDT WED MAY 16 2012
FRIDAY AFTERNOON SOUTH WINDS WILL STRENGTHEN...WITH GUSTS UP TO 40
MPH ACROSS THE AREA. RELATIVE HUMIDITIES WILL FALL INTO THE 10 TO
20 PERCENT RANGE DURING THE AFTERNOON FOR LOCATIONS WEST OF A
MCCOOK TO GOVE LINE...LEADING TO HAZARDOUS FIRE WEATHER
CONDITIONS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING UNTIL 8 PM MDT /9 PM CDT/ THIS EVENING FOR
KSZ001-013-027.
CO...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ252>254.
NE...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR NEZ079.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...DR
FIRE WEATHER...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
151 PM MDT WED MAY 16 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 150 PM MDT WED MAY 16 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW SHORTWAVE RIDGE
OVER WESTERN KS BEGINNING TO BREAK DOWN AS SHORTWAVE TROUGH OVER
GREAT BASIN CONTINUES TO MOVE EAST INTO THE CENTRAL ROCKIES. TIGHT
GRADIENT CURRENTLY IN PLACE ACROSS CWA NO EASTERN EXTENT OF LEE
TROUGH HAS LED TO BREEZY CONDITIONS ACROSS THE AREA...WITH WINDS
GUSTING AROUND 30KT AT SEVERAL LOCATIONS. A WARM FRONT JUST
SOUTHWEST OF GOODLAND LIFTING TO THE NORTHEAST. WEST OF THIS FRONT
RH VALUES HAVE DROPPED TO 15% OR LOWER. WITH SEVERAL LOCATIONS
ALREADY WITHIN RED FLAG CRITERIA...PLAN ON KEEPING RFW IN PLACE
THROUGH EXPIRATION (02Z).
SHORTWAVE TROUGH WILL CONTINUE TO MOVE EAST WITH LARGE SCALE ASCENT
SPREADING INTO EASTERN COLORADO. RADAR RETURNS ALREADY SHOWING
SHOWERS/THUNDERSTORMS ALONG FRONT RANGE...WITH ACTIVITY GENERALLY
MOVING FROM THE SOUTH TO NORTH. LATEST RUC/HRRR SHOW THIS ACTIVITY
REMAINING JUST EAST OF THE CWA. WITH LARGE SCALE ASCENT STILL
EXPECTED TO OVERSPREAD THE CWA...AND THE CLOSE PROXIMITY OF
ACTIVITY...I DECIDED TO LEAVE ISOLATED THUNDERSTORMS IN FORECAST
THIS EVENING.
SHORTWAVE TROUGH AXIS CURRENTLY PROGGED TO MOVE EAST ACROSS WESTERN
KS. GUIDANCE IN GENERAL AGREEMENT ON TIMING...HOWEVER STRENGTH AND
POSITION OF SHORTWAVE ARE STILL ISSUES...WITH KEEPING OUR CWA
DRY...AND OTHER GUIDANCE FAVORING THE SOUTH AND EAST LATE THURSDAY
AFTERNOON. WITH INSTABILITY/LARGE SCALE ASCENT ACROSS THE CWA
THURSDAY...SLIGHT CHANCE POPS FROM PREVIOUS FORECAST SEEMED
REASONABLE. TIGHT SURFACE GRADIENT WILL REMAIN IN PLACE OVER EASTERN
PARTS OF CWA...WITH NAM/GFS BL WINDS APPROACHING ADVISORY CRITERIA
FOR A PERIOD OF TIME THURSDAY AFTERNOON. CONFIDENCE IS NOT THERE
THAT ADVISORY CRITERIA WINDS WILL LAST 3HR...SO NO HAZARD PLANNED.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 244 AM MDT WED MAY 16 2012
THURSDAY NIGHT-FRIDAY NIGHT...WEAK SHORT WAVE RIDGING WILL BUILD
OVER THE AREA DURING THE EVENING HOURS...BRINGING AN END TO ANY
PRECIP CHANCES DURING THE OVERNIGHT HOURS. NEXT SHORT WAVE TROUGH
WILL MOVE OVER THE FOUR CORNERS AREA AND INTO COLORADO BY FRIDAY
NIGHT. WHILE LARGE SCALE FORCING FOR ASCENT WITH UPPER TROUGH NOT
EXPECTED TO INFLUENCE THE AREA DIRECTLY UNTIL AROUND 12Z WHEN COLD
FRONT ENTERS CWA...HAVE SOME CONCERNS ABOUT POTENTIAL FOR
THUNDERSTORMS ALONG SFC TROUGH/DRYLINE LATE FRIDAY AFTERNOON AND
EVENING. STRONGEST LOW LEVEL CONVERGENCE EXPECTED TO THE SOUTH OF
SFC LOW CENTERED OVER NORTHEASTERN COLORADO/NEB PANHANDLE. MOISTURE
ADVECTION LOOKS A BIT STRONGER THAN PREVIOUS SYSTEM WITH TDS IN THE
MID 40S TO LOW 50S EXPECTED EAST OF DRY LINE. WHILE THERE IS A SMALL
POTENTIAL FOR STORMS...THINK PROBABILITIES SHOULD REMAIN FAIRLY LOW
FOR THE TIME BEING AS HIGHEST TDS/INSTABILITY WILL BE WELL TO THE
EAST OF BEST SFC CONVERGENCE AND WITH LARGE SCALE FORCING NOT
BECOMING STRONG UNTIL AROUND 12Z THINK SFC FEATURES WILL BE PRIMARY
MEANS FOR ANY CONVECTIVE INITIATION. WINDS INCREASE SHARPLY DURING
THE DAY FRIDAY...ESPECIALLY TO THE EAST OF SFC TROUGH INCREASING
SHARPLY AROUND 00Z. STILL A FAIRLY LARGE DISCREPANCY ON HOW STRONG
WINDS ALOFT WILL BE...BUT THERE LOOKS TO BE AT LEAST SOME POTENTIAL
FOR ADVISORY TYPE WINDS LATE FRIDAY AFTERNOON AND EARLY EVENING.
WINDS SHOULD REMAIN STRONG/GUSTY DURING THE OVERNIGHT HOURS AHEAD OF
COLD FRONT KEEPING LOWS MUCH WARMER THAN THE PAST FEW DAYS WITH MANY
LOCATIONS SEEING LOWS STAY IN THE 60S.
A STRONG COLD FRONT WILL MOVE THROUGH THE REGION SATURDAY MORNING
AHEAD OF A SHORTWAVE TROUGH THAT WILL MOVE THROUGH THE CENTRAL
ROCKIES AND INTO KANSAS BEFORE SWINGING UP INTO NEBRASKA BY SATURDAY
EVENING. PRECIPITATION CHANCES WILL INCREASE AS THE FRONT MOVES
THROUGH THE REGION...WITH BEST CHANCES ACROSS THE NORTHERN HALF OF
THE CWA. DRY SLOT APPEARS TO DEVELOP AND WILL KEEP PRECIPITATION
CHANCES LOW ACROSS PARTS OF SOUTHEAST COLORADO AND SOUTHWEST KANSAS.
COOLER AIR WILL MOVE IN BEHIND THE FRONT WITH A GRADUAL WARMING
THROUGH NEXT WEEK. ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH THE
REGION ON SUNDAY...BUT WITH HIGHER SURFACE DEWPOINTS EXPECTED TO BE
MUCH FURTHER EASTWARD ACROSS EASTERN KANSAS...AM NOT EXPECTING
THUNDERSTORMS TO DEVELOP SUNDAY AFTERNOON. BY EARLY NEXT
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1217 PM MDT WED MAY 16 2012
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD AT BOTH KGLD AND
KMCK. GUSTY WINDS EXPECTED THROUGH MOST OF THE TAF PERIOD AT BOTH
SITES WITH STRONGEST WINDS THIS AFTERNOON 25-30KT. WINDS SHOULD
DECREASE SLIGHTLY AFTER SUNSET...THOUGH THEY WILL REMAIN GUSTY AT
BOTH TERMINALS THROUGH THURSDAY MORNING AS UPPER LEVEL DISTURBANCE
MOVES EAST. THERE IS A SMALL CHANCE FOR A THUNDERSTORM AT KGLD THIS
AFTERNOON/EVENING AND AT BOTH KGLD AND KMCK THURSDAY AFTERNOON.
COVERAGE WILL BE VERY LIMITED...SO LEFT MENTION OUT OF TAFS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING UNTIL 8 PM MDT /9 PM CDT/ THIS EVENING FOR
KSZ001-013-027.
CO...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ252>254.
NE...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR NEZ079.
&&
$$
SHORT TERM...DR
LONG TERM...JRM/PM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1217 PM MDT WED MAY 16 2012
.UPDATE...
ISSUED AT 911 AM MDT WED MAY 16 2012
FORECAST GENERALLY ON TRACK...WITH ONLY MINOR ADJUSTMENTS TO CATCH
LATEST TRENDS. TD FORECAST ACROSS EASTERN CWA MAY BE TOO HIGH
CONSIDERING LIMITED MOISTURE ADVECTION AND TD VALUES STARTING IN
THE MID TO HIGH 30S. LATEST RUC SEEMED TO HAVE A BETTER HANDLE ON
CURRENT TRENDS SO USED THAT AS A STARTING POINT. OVERALL THIS
RESULTS IN LOWER RH VALUES FURTHER EAST THAN PREVIOUSLY
ADVERTISED...WITH RFW CONDITIONS POSSIBLE FURTHER EAST. QUESTION
REMAINS FUELS ACROSS THE AREA...WITH CURRENT INDICATION THAT FUELS
REMAIN GREEN THE FURTHER EAST IN THE CWA. DISCUSSIONS WITH LOCAL
AUTHORITIES FROM DUNDY COUNTY AND NEAR THE CHEYENNE KANSAS BORDER
INDICATE FAVORABLE FUELS. WITH SHERMAN KS AND CHASE NE ALREADY
UNDER A RED FLAG WARNING I DECIDED TO EXTEND CURRENT RED FLAG
WARNING TO INCLUDE DUNDY AND CHEYENNE BASED ON THESE FUEL
OBSERVATIONS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 244 AM MDT WED MAY 16 2012
0330Z WATER VAPOR INDICATED SHORT WAVE RIDGE IN PLACE ACROSS THE THE
HIGH PLAINS...WITH CLOSED CIRCULATION ASSOCIATED WITH STRONG SHORT
WAVE TROUGH MOVING INTO SOUTHWESTERN UTAH. THIS TROUGH ALREADY
TAKING A MORE SOUTHERLY TRACK THAN PREVIOUSLY EXPECTED AND OVERALL
OBSERVED 12 HOUR HEIGHT FALLS PRETTY WEAK AHEAD OF THIS SYSTEM. 00Z
RAOBS INDICATE A WARM...WELL MIXED AND STABLE AIRMASS WAS IN PLACE
ACROSS THE AREA...WITH VERY DRY AIR/LOW PW`S AT DDC/DNR AND LBF. AT
THE SFC...1021MB SFC HIGH WAS CENTERED OVER NORTHEASTERN NEBRASKA
WITH COLD FRONT FROM APPROX KLAA TO KSLN TO KMCI.
MAIN FORECAST CONCERNS WILL BE FIRE WEATHER AND TEMPS
TODAY...FOLLOWED BY PRECIP CHANCES TONIGHT THROUGH THE WEEKEND.
SHORT TERM...SHORT WAVE TROUGH CURRENTLY MOVING INTO WESTERN UTAH
WILL BE PRIMARY INFLUENCE OF THE WEATHER ACROSS THE CWA AS IT
APPROACHES DURING THE DAY. DRY CONDITIONS ARE EXPECTED THROUGH MUCH
OF THE DAY...BUT SUBSIDENCE WILL DECREASE THROUGH THE MORNING HOURS
AS WEAK LARGE SCALE FORCING ASCENT INCREASES DURING THE AFTERNOON.
ALTHOUGH LIFT DOES INCREASE...LITTLE WITH ATMOSPHERE PROCEEDING
INCOMING TROUGH HAVING VERY LARGE TD DEPRESSIONS...THINK IT WILL BE
DIFFICULT TO HAVE MUCH CHANCE SATURATING/INITIATING ANYTHING UNTIL
VERY LATE IN THE DAY. WHILE BEST LARGE SCALE FORCING APPEARS TO
FAVOR EASTERN COLORADO...DO HAVE A FEW CONCERNS ABOUT CONVECTIVE
INITIATION ALONG RETREATING FRONTAL ZONE IN EASTERN CWA WHERE MORE
INSTABILITY/BETTER MOISTURE PROFILES ARE PRESENT. MAIN ISSUE HERE
WILL BE WHETHER CINH CAN BE OVERCOME AS VALUES ARE EXPECTED TO
REMAIN IN THE 50-150 J/KG RANGE. INITIAL PLAN WAS TO LEAVE OUT...BUT
WANT TO SEE SOME OF THE HIGHER RES DATA BEFORE MAKING A FINAL CALL
HERE. WINDS WILL INCREASE TO AROUND 20KTS IN AREAS SOUTH OF FRONTAL
ZONE. WITH DEEP MIXING EXPECTED TO DROP TDS SHARPLY TO SOUTH OF
FRONT AND CURRENT RFW LOOKS TO BE IN GOOD SHAPE. COULD MAKE AN
ARGUMENT FOR EXTENDING IT TO THE NORTH...BUT WITH RECENT RELATIVE
GREENNESS DATA SHOWING THINGS GREENING UP QUITE A BIT IN CHEYENNE
KS...THINK A WARNING NOT NEEDED AS FUELS MAY NOT BE CRITICAL.
OVERNIGHT LARGE SCALE FORCING FOR ASCENT WILL CONTINUE...ALTHOUGH
MORE SOUTHERLY TRACK OF SYSTEM RESULTS IN MUCH WEAKER AND A MORE
FURTHER WEST/SOUTH AREA OF MAXIMUM ASCENT. WITH THIS IN
MIND...CONFIDENCE MUCH LOWER THAN 24 HOURS AGO WITH RESPECT TO
PRECIP COVERAGE AND OVERALL CHANCES. HAVE DOUBTS THAT ANY STORMS
WILL MAKE IT MUCH FARTHER EAST THAN EASTERN COLORADO GIVEN THE VERY
LIMITED INSTABILITY AND MOISTURE PROFILES AND DO NOT THINK GOING
HIGHER THAN SLIGHT CHANCES AT THIS POINT. SHORT WAVE TROUGH WILL
CONTINUE TO IMPACT THE AREA THROUGH THE DAY THURSDAY...ALTHOUGH Q
VECTOR FIELDS SUGGEST LARGE SCALE FORCING FOR ASCENT WILL BE
MAXIMIZED TO THE SOUTH OF THE AREA. WHILE LARGE SCALE FORCING NOT
ALL THAT GREAT...INSTABILITY VALUES HIGHER AND WITH TEMPS ALOFT
COOLER CINH VALUES WEAKER. MOISTURE RETURN CONCERNS STILL EXIST FOR
PERIOD AS THERE DOES NOT APPEAR TO BE ANY MEANINGFUL MOISTURE
RETURN...SO THINK LIMITING POPS TO THE 20 PERCENT RANGE IN ORDER.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 244 AM MDT WED MAY 16 2012
THURSDAY NIGHT-FRIDAY NIGHT...WEAK SHORT WAVE RIDGING WILL BUILD
OVER THE AREA DURING THE EVENING HOURS...BRINGING AN END TO ANY
PRECIP CHANCES DURING THE OVERNIGHT HOURS. NEXT SHORT WAVE TROUGH
WILL MOVE OVER THE FOUR CORNERS AREA AND INTO COLORADO BY FRIDAY
NIGHT. WHILE LARGE SCALE FORCING FOR ASCENT WITH UPPER TROUGH NOT
EXPECTED TO INFLUENCE THE AREA DIRECTLY UNTIL AROUND 12Z WHEN COLD
FRONT ENTERS CWA...HAVE SOME CONCERNS ABOUT POTENTIAL FOR
THUNDERSTORMS ALONG SFC TROUGH/DRYLINE LATE FRIDAY AFTERNOON AND
EVENING. STRONGEST LOW LEVEL CONVERGENCE EXPECTED TO THE SOUTH OF
SFC LOW CENTERED OVER NORTHEASTERN COLORADO/NEB PANHANDLE. MOISTURE
ADVECTION LOOKS A BIT STRONGER THAN PREVIOUS SYSTEM WITH TDS IN THE
MID 40S TO LOW 50S EXPECTED EAST OF DRY LINE. WHILE THERE IS A SMALL
POTENTIAL FOR STORMS...THINK PROBABILITIES SHOULD REMAIN FAIRLY LOW
FOR THE TIME BEING AS HIGHEST TDS/INSTABILITY WILL BE WELL TO THE
EAST OF BEST SFC CONVERGENCE AND WITH LARGE SCALE FORCING NOT
BECOMING STRONG UNTIL AROUND 12Z THINK SFC FEATURES WILL BE PRIMARY
MEANS FOR ANY CONVECTIVE INITIATION. WINDS INCREASE SHARPLY DURING
THE DAY FRIDAY...ESPECIALLY TO THE EAST OF SFC TROUGH INCREASING
SHARPLY AROUND 00Z. STILL A FAIRLY LARGE DISCREPANCY ON HOW STRONG
WINDS ALOFT WILL BE...BUT THERE LOOKS TO BE AT LEAST SOME POTENTIAL
FOR ADVISORY TYPE WINDS LATE FRIDAY AFTERNOON AND EARLY EVENING.
WINDS SHOULD REMAIN STRONG/GUSTY DURING THE OVERNIGHT HOURS AHEAD OF
COLD FRONT KEEPING LOWS MUCH WARMER THAN THE PAST FEW DAYS WITH MANY
LOCATIONS SEEING LOWS STAY IN THE 60S.
A STRONG COLD FRONT WILL MOVE THROUGH THE REGION SATURDAY MORNING
AHEAD OF A SHORTWAVE TROUGH THAT WILL MOVE THROUGH THE CENTRAL
ROCKIES AND INTO KANSAS BEFORE SWINGING UP INTO NEBRASKA BY SATURDAY
EVENING. PRECIPITATION CHANCES WILL INCREASE AS THE FRONT MOVES
THROUGH THE REGION...WITH BEST CHANCES ACROSS THE NORTHERN HALF OF
THE CWA. DRY SLOT APPEARS TO DEVELOP AND WILL KEEP PRECIPITATION
CHANCES LOW ACROSS PARTS OF SOUTHEAST COLORADO AND SOUTHWEST KANSAS.
COOLER AIR WILL MOVE IN BEHIND THE FRONT WITH A GRADUAL WARMING
THROUGH NEXT WEEK. ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH THE
REGION ON SUNDAY...BUT WITH HIGHER SURFACE DEWPOINTS EXPECTED TO BE
MUCH FURTHER EASTWARD ACROSS EASTERN KANSAS...AM NOT EXPECTING
THUNDERSTORMS TO DEVELOP SUNDAY AFTERNOON. BY EARLY NEXT
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1217 PM MDT WED MAY 16 2012
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD AT BOTH KGLD AND
KMCK. GUSTY WINDS EXPECTED THROUGH MOST OF THE TAF PERIOD AT BOTH
SITES WITH STRONGEST WINDS THIS AFTERNOON 25-30KT. WINDS SHOULD
DECREASE SLIGHTLY AFTER SUNSET...THOUGH THEY WILL REMAIN GUSTY AT
BOTH TERMINALS THROUGH THURSDAY MORNING AS UPPER LEVEL DISTURBANCE
MOVES EAST. THERE IS A SMALL CHANCE FOR A THUNDERSTORM AT KGLD THIS
AFTERNOON/EVENING AND AT BOTH KGLD AND KMCK THURSDAY AFTERNOON.
COVERAGE WILL BE VERY LIMITED...SO LEFT MENTION OUT OF TAFS.
&&
.FIRE WEATHER...
ISSUED AT 236 AM MDT WED MAY 16 2012
CRITICAL FIRE WEATHER CONDITIONS EXPECTED TODAY AS A DEVELOPING
SURFACE TROUGH BRINGS SOUTHERLY WINDS OF 15 TO 25 MPH TO THE AREA
AND AFTERNOON HUMIDITIES FALL TO LESS THAN 15 PERCENT ACROSS MUCH
OF THE AREA. BASED ON LATEST FUEL REPORTS AND AVAILABLE SATELLITE
GREENESS DATA...IT APPEARS THAT WITH THE EXCEPTION OF PORTIONS OF
EASTERN COLORADO AND ADJACENT AREAS OF NORTHWEST KANSAS WIDESPREAD
CRITICAL FUELS ARE NOT AVAILABLE.
AFTERNOON HUMIDITIES WILL FALL TO THE 10 TO 20 PERCENT RANGE EACH
AFTERNOON THROUGH FRIDAY. WINDS ARE EXPECTED TO REMAIN CRITICAL
VALUES ON THURSDAY...BUT WILL INCREASE THROUGH THE DAY FRIDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING UNTIL 8 PM MDT /9 PM CDT/ THIS EVENING FOR
KSZ001-013-027.
CO...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ252>254.
NE...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR NEZ079.
&&
$$
UPDATE...DR
SHORT TERM...JRM
LONG TERM...JRM/PM
AVIATION...DR
FIRE WEATHER...JRM
AREA FORECAST DISCUSSION...CORRECTED
NWS GOODLAND KS
924 AM MDT WED MAY 16 2012
.UPDATE...
ISSUED AT 911 AM MDT WED MAY 16 2012
FORECAST GENERALLY ON TRACK...WITH ONLY MINOR ADJUSTMENTS TO CATCH
LATEST TRENDS. TD FORECAST ACROSS EASTERN CWA MAY BE TOO HIGH
CONSIDERING LIMITED MOISTURE ADVECTION AND TD VALUES STARTING IN
THE MID TO HIGH 30S. LATEST RUC SEEMED TO HAVE A BETTER HANDLE ON
CURRENT TRENDS SO USED THAT AS A STARTING POINT. OVERALL THIS
RESULTS IN LOWER RH VALUES FURTHER EAST THAN PREVIOUSLY
ADVERTISED...WITH RFW CONDITIONS POSSIBLE FURTHER EAST. QUESTION
REMAINS FUELS ACROSS THE AREA...WITH CURRENT INDICATION THAT FUELS
REMAIN GREEN THE FURTHER EAST IN THE CWA. DISCUSSIONS WITH LOCAL
AUTHORITIES FROM DUNDY COUNTY AND NEAR THE CHEYENNE KANSAS BORDER
INDICATE FAVORABLE FUELS. WITH SHERMAN KS AND CHASE NE ALREADY
UNDER A RED FLAG WARNING I DECIDED TO EXTEND CURRENT RED FLAG
WARNING TO INCLUDE DUNDY AND CHEYENNE BASED ON THESE FUEL
OBSERVATIONS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 244 AM MDT WED MAY 16 2012
0330Z WATER VAPOR INDICATED SHORT WAVE RIDGE IN PLACE ACROSS THE THE
HIGH PLAINS...WITH CLOSED CIRCULATION ASSOCIATED WITH STRONG SHORT
WAVE TROUGH MOVING INTO SOUTHWESTERN UTAH. THIS TROUGH ALREADY
TAKING A MORE SOUTHERLY TRACK THAN PREVIOUSLY EXPECTED AND OVERALL
OBSERVED 12 HOUR HEIGHT FALLS PRETTY WEAK AHEAD OF THIS SYSTEM. 00Z
RAOBS INDICATE A WARM...WELL MIXED AND STABLE AIRMASS WAS IN PLACE
ACROSS THE AREA...WITH VERY DRY AIR/LOW PW`S AT DDC/DNR AND LBF. AT
THE SFC...1021MB SFC HIGH WAS CENTERED OVER NORTHEASTERN NEBRASKA
WITH COLD FRONT FROM APPROX KLAA TO KSLN TO KMCI.
MAIN FORECAST CONCERNS WILL BE FIRE WEATHER AND TEMPS
TODAY...FOLLOWED BY PRECIP CHANCES TONIGHT THROUGH THE WEEKEND.
SHORT TERM...SHORT WAVE TROUGH CURRENTLY MOVING INTO WESTERN UTAH
WILL BE PRIMARY INFLUENCE OF THE WEATHER ACROSS THE CWA AS IT
APPROACHES DURING THE DAY. DRY CONDITIONS ARE EXPECTED THROUGH MUCH
OF THE DAY...BUT SUBSIDENCE WILL DECREASE THROUGH THE MORNING HOURS
AS WEAK LARGE SCALE FORCING ASCENT INCREASES DURING THE AFTERNOON.
ALTHOUGH LIFT DOES INCREASE...LITTLE WITH ATMOSPHERE PROCEEDING
INCOMING TROUGH HAVING VERY LARGE TD DEPRESSIONS...THINK IT WILL BE
DIFFICULT TO HAVE MUCH CHANCE SATURATING/INITIATING ANYTHING UNTIL
VERY LATE IN THE DAY. WHILE BEST LARGE SCALE FORCING APPEARS TO
FAVOR EASTERN COLORADO...DO HAVE A FEW CONCERNS ABOUT CONVECTIVE
INITIATION ALONG RETREATING FRONTAL ZONE IN EASTERN CWA WHERE MORE
INSTABILITY/BETTER MOISTURE PROFILES ARE PRESENT. MAIN ISSUE HERE
WILL BE WHETHER CINH CAN BE OVERCOME AS VALUES ARE EXPECTED TO
REMAIN IN THE 50-150 J/KG RANGE. INITIAL PLAN WAS TO LEAVE OUT...BUT
WANT TO SEE SOME OF THE HIGHER RES DATA BEFORE MAKING A FINAL CALL
HERE. WINDS WILL INCREASE TO AROUND 20KTS IN AREAS SOUTH OF FRONTAL
ZONE. WITH DEEP MIXING EXPECTED TO DROP TDS SHARPLY TO SOUTH OF
FRONT AND CURRENT RFW LOOKS TO BE IN GOOD SHAPE. COULD MAKE AN
ARGUMENT FOR EXTENDING IT TO THE NORTH...BUT WITH RECENT RELATIVE
GREENNESS DATA SHOWING THINGS GREENING UP QUITE A BIT IN CHEYENNE
KS...THINK A WARNING NOT NEEDED AS FUELS MAY NOT BE CRITICAL.
OVERNIGHT LARGE SCALE FORCING FOR ASCENT WILL CONTINUE...ALTHOUGH
MORE SOUTHERLY TRACK OF SYSTEM RESULTS IN MUCH WEAKER AND A MORE
FURTHER WEST/SOUTH AREA OF MAXIMUM ASCENT. WITH THIS IN
MIND...CONFIDENCE MUCH LOWER THAN 24 HOURS AGO WITH RESPECT TO
PRECIP COVERAGE AND OVERALL CHANCES. HAVE DOUBTS THAT ANY STORMS
WILL MAKE IT MUCH FARTHER EAST THAN EASTERN COLORADO GIVEN THE VERY
LIMITED INSTABILITY AND MOISTURE PROFILES AND DO NOT THINK GOING
HIGHER THAN SLIGHT CHANCES AT THIS POINT. SHORT WAVE TROUGH WILL
CONTINUE TO IMPACT THE AREA THROUGH THE DAY THURSDAY...ALTHOUGH Q
VECTOR FIELDS SUGGEST LARGE SCALE FORCING FOR ASCENT WILL BE
MAXIMIZED TO THE SOUTH OF THE AREA. WHILE LARGE SCALE FORCING NOT
ALL THAT GREAT...INSTABILITY VALUES HIGHER AND WITH TEMPS ALOFT
COOLER CINH VALUES WEAKER. MOISTURE RETURN CONCERNS STILL EXIST FOR
PERIOD AS THERE DOES NOT APPEAR TO BE ANY MEANINGFUL MOISTURE
RETURN...SO THINK LIMITING POPS TO THE 20 PERCENT RANGE IN ORDER.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 244 AM MDT WED MAY 16 2012
THURSDAY NIGHT-FRIDAY NIGHT...WEAK SHORT WAVE RIDGING WILL BUILD
OVER THE AREA DURING THE EVENING HOURS...BRINGING AN END TO ANY
PRECIP CHANCES DURING THE OVERNIGHT HOURS. NEXT SHORT WAVE TROUGH
WILL MOVE OVER THE FOUR CORNERS AREA AND INTO COLORADO BY FRIDAY
NIGHT. WHILE LARGE SCALE FORCING FOR ASCENT WITH UPPER TROUGH NOT
EXPECTED TO INFLUENCE THE AREA DIRECTLY UNTIL AROUND 12Z WHEN COLD
FRONT ENTERS CWA...HAVE SOME CONCERNS ABOUT POTENTIAL FOR
THUNDERSTORMS ALONG SFC TROUGH/DRYLINE LATE FRIDAY AFTERNOON AND
EVENING. STRONGEST LOW LEVEL CONVERGENCE EXPECTED TO THE SOUTH OF
SFC LOW CENTERED OVER NORTHEASTERN COLORADO/NEB PANHANDLE. MOISTURE
ADVECTION LOOKS A BIT STRONGER THAN PREVIOUS SYSTEM WITH TDS IN THE
MID 40S TO LOW 50S EXPECTED EAST OF DRY LINE. WHILE THERE IS A SMALL
POTENTIAL FOR STORMS...THINK PROBABILITIES SHOULD REMAIN FAIRLY LOW
FOR THE TIME BEING AS HIGHEST TDS/INSTABILITY WILL BE WELL TO THE
EAST OF BEST SFC CONVERGENCE AND WITH LARGE SCALE FORCING NOT
BECOMING STRONG UNTIL AROUND 12Z THINK SFC FEATURES WILL BE PRIMARY
MEANS FOR ANY CONVECTIVE INITIATION. WINDS INCREASE SHARPLY DURING
THE DAY FRIDAY...ESPECIALLY TO THE EAST OF SFC TROUGH INCREASING
SHARPLY AROUND 00Z. STILL A FAIRLY LARGE DISCREPANCY ON HOW STRONG
WINDS ALOFT WILL BE...BUT THERE LOOKS TO BE AT LEAST SOME POTENTIAL
FOR ADVISORY TYPE WINDS LATE FRIDAY AFTERNOON AND EARLY EVENING.
WINDS SHOULD REMAIN STRONG/GUSTY DURING THE OVERNIGHT HOURS AHEAD OF
COLD FRONT KEEPING LOWS MUCH WARMER THAN THE PAST FEW DAYS WITH MANY
LOCATIONS SEEING LOWS STAY IN THE 60S.
A STRONG COLD FRONT WILL MOVE THROUGH THE REGION SATURDAY MORNING
AHEAD OF A SHORTWAVE TROUGH THAT WILL MOVE THROUGH THE CENTRAL
ROCKIES AND INTO KANSAS BEFORE SWINGING UP INTO NEBRASKA BY SATURDAY
EVENING. PRECIPITATION CHANCES WILL INCREASE AS THE FRONT MOVES
THROUGH THE REGION...WITH BEST CHANCES ACROSS THE NORTHERN HALF OF
THE CWA. DRY SLOT APPEARS TO DEVELOP AND WILL KEEP PRECIPITATION
CHANCES LOW ACROSS PARTS OF SOUTHEAST COLORADO AND SOUTHWEST KANSAS.
COOLER AIR WILL MOVE IN BEHIND THE FRONT WITH A GRADUAL WARMING
THROUGH NEXT WEEK. ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH THE
REGION ON SUNDAY...BUT WITH HIGHER SURFACE DEWPOINTS EXPECTED TO BE
MUCH FURTHER EASTWARD ACROSS EASTERN KANSAS...AM NOT EXPECTING
THUNDERSTORMS TO DEVELOP SUNDAY AFTERNOON. BY EARLY NEXT
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 536 AM MDT WED MAY 16 2012
VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS AS UPPER LEVEL
DISTURBANCE APPROACHES FROM THE WEST. PERIOD OF LLWS AT GLD SHOULD
END QUICKLY THIS MORNING AS SFC WINDS INCREASE WITH HEATING.
SOUTHEASTERLY WINDS WILL GRADUALLY SHIFT TO THE SOUTH AND INCREASE
TO AROUND 20KTS...MAINLY AFTER 17Z. THERE IS A SMALL CHANCE FOR
THUNDERSTORMS BTWN 00Z AND 06Z...BUT THESE SHOULD REMAIN WELL TO
THE WEST OF TAF SITES.
&&
.FIRE WEATHER...
ISSUED AT 236 AM MDT WED MAY 16 2012
CRITICAL FIRE WEATHER CONDITIONS EXPECTED TODAY AS A DEVELOPING
SURFACE TROUGH BRINGS SOUTHERLY WINDS OF 15 TO 25 MPH TO THE AREA
AND AFTERNOON HUMIDITIES FALL TO LESS THAN 15 PERCENT ACROSS MUCH
OF THE AREA. BASED ON LATEST FUEL REPORTS AND AVAILABLE SATELLITE
GREENESS DATA...IT APPEARS THAT WITH THE EXCEPTION OF PORTIONS OF
EASTERN COLORADO AND ADJACENT AREAS OF NORTHWEST KANSAS WIDESPREAD
CRITICAL FUELS ARE NOT AVAILABLE.
AFTERNOON HUMIDITIES WILL FALL TO THE 10 TO 20 PERCENT RANGE EACH
AFTERNOON THROUGH FRIDAY. WINDS ARE EXPECTED TO REMAIN CRITICAL
VALUES ON THURSDAY...BUT WILL INCREASE THROUGH THE DAY FRIDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING UNTIL 8 PM MDT /9 PM CDT/ THIS EVENING FOR
KSZ001-013-027.
CO...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ252>254.
NE...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR NEZ079.
&&
$$
UPDATE...DR
SHORT TERM...JRM
LONG TERM...JRM/PM
AVIATION...JRM
FIRE WEATHER...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
912 AM MDT WED MAY 16 2012
.UPDATE...
ISSUED AT 911 AM MDT WED MAY 16 2012
FORECAST GENERALLY ON TRACK...WITH ONLY MINOR ADJUSTMENTS TO CATCH
LATEST TRENDS. TD FORECAST ACROSS EASTERN CWA MAY BE TOO HIGH
CONSIDERING LIMITED MOISTURE ADVECTION AND TD VALUES STARTING IN
THE MID TO HIGH 30S. LATEST RUC SEEMED TO HAVE A BETTER HANDLE ON
CURRENT TRENDS SO USED THAT AS A STARTING POINT. OVERALL THIS
RESULTS IN LOWER RH VALUES FURTHER EAST THAN PREVIOUSLY
ADVERTISED...WITH RFW CONDITIONS POSSIBLE FURTHER EAST. QUESTION
REMAINS FUELS ACROSS THE AREA...WITH CURRENT INDICATION THAT FUELS
REMAIN GREEN THE FURTHER EAST IN THE CWA. DISCUSSIONS WITH LOCAL
AUTHORITIES FROM DUN DY COUNTY AND NEAR THE CHEYENNE KANSAS BORDER
INDICATE FAVORABLE FUELS. WITH SHERMAN KS AND CHASE NE ALREADY
UNDER A RED FLAG WARNING I DECIDED TO EXTEND CURRENT RED FLAG
WARNING TO INCLUDE DUN DY AND CHEYENNE BASED ON THESE FUEL
OBSERVATIONS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 244 AM MDT WED MAY 16 2012
0330Z WATER VAPOR INDICATED SHORT WAVE RIDGE IN PLACE ACROSS THE THE
HIGH PLAINS...WITH CLOSED CIRCULATION ASSOCIATED WITH STRONG SHORT
WAVE TROUGH MOVING INTO SOUTHWESTERN UTAH. THIS TROUGH ALREADY
TAKING A MORE SOUTHERLY TRACK THAN PREVIOUSLY EXPECTED AND OVERALL
OBSERVED 12 HOUR HEIGHT FALLS PRETTY WEAK AHEAD OF THIS SYSTEM. 00Z
RAOBS INDICATE A WARM...WELL MIXED AND STABLE AIRMASS WAS IN PLACE
ACROSS THE AREA...WITH VERY DRY AIR/LOW PW`S AT DDC/DNR AND LBF. AT
THE SFC...1021MB SFC HIGH WAS CENTERED OVER NORTHEASTERN NEBRASKA
WITH COLD FRONT FROM APPROX KLAA TO KSLN TO KMCI.
MAIN FORECAST CONCERNS WILL BE FIRE WEATHER AND TEMPS
TODAY...FOLLOWED BY PRECIP CHANCES TONIGHT THROUGH THE WEEKEND.
SHORT TERM...SHORT WAVE TROUGH CURRENTLY MOVING INTO WESTERN UTAH
WILL BE PRIMARY INFLUENCE OF THE WEATHER ACROSS THE CWA AS IT
APPROACHES DURING THE DAY. DRY CONDITIONS ARE EXPECTED THROUGH MUCH
OF THE DAY...BUT SUBSIDENCE WILL DECREASE THROUGH THE MORNING HOURS
AS WEAK LARGE SCALE FORCING ASCENT INCREASES DURING THE AFTERNOON.
ALTHOUGH LIFT DOES INCREASE...LITTLE WITH ATMOSPHERE PROCEEDING
INCOMING TROUGH HAVING VERY LARGE TD DEPRESSIONS...THINK IT WILL BE
DIFFICULT TO HAVE MUCH CHANCE SATURATING/INITIATING ANYTHING UNTIL
VERY LATE IN THE DAY. WHILE BEST LARGE SCALE FORCING APPEARS TO
FAVOR EASTERN COLORADO...DO HAVE A FEW CONCERNS ABOUT CONVECTIVE
INITIATION ALONG RETREATING FRONTAL ZONE IN EASTERN CWA WHERE MORE
INSTABILITY/BETTER MOISTURE PROFILES ARE PRESENT. MAIN ISSUE HERE
WILL BE WHETHER CINH CAN BE OVERCOME AS VALUES ARE EXPECTED TO
REMAIN IN THE 50-150 J/KG RANGE. INITIAL PLAN WAS TO LEAVE OUT...BUT
WANT TO SEE SOME OF THE HIGHER RES DATA BEFORE MAKING A FINAL CALL
HERE. WINDS WILL INCREASE TO AROUND 20KTS IN AREAS SOUTH OF FRONTAL
ZONE. WITH DEEP MIXING EXPECTED TO DROP TDS SHARPLY TO SOUTH OF
FRONT AND CURRENT RFW LOOKS TO BE IN GOOD SHAPE. COULD MAKE AN
ARGUMENT FOR EXTENDING IT TO THE NORTH...BUT WITH RECENT RELATIVE
GREENNESS DATA SHOWING THINGS GREENING UP QUITE A BIT IN CHEYENNE
KS...THINK A WARNING NOT NEEDED AS FUELS MAY NOT BE CRITICAL.
OVERNIGHT LARGE SCALE FORCING FOR ASCENT WILL CONTINUE...ALTHOUGH
MORE SOUTHERLY TRACK OF SYSTEM RESULTS IN MUCH WEAKER AND A MORE
FURTHER WEST/SOUTH AREA OF MAXIMUM ASCENT. WITH THIS IN
MIND...CONFIDENCE MUCH LOWER THAN 24 HOURS AGO WITH RESPECT TO
PRECIP COVERAGE AND OVERALL CHANCES. HAVE DOUBTS THAT ANY STORMS
WILL MAKE IT MUCH FARTHER EAST THAN EASTERN COLORADO GIVEN THE VERY
LIMITED INSTABILITY AND MOISTURE PROFILES AND DO NOT THINK GOING
HIGHER THAN SLIGHT CHANCES AT THIS POINT. SHORT WAVE TROUGH WILL
CONTINUE TO IMPACT THE AREA THROUGH THE DAY THURSDAY...ALTHOUGH Q
VECTOR FIELDS SUGGEST LARGE SCALE FORCING FOR ASCENT WILL BE
MAXIMIZED TO THE SOUTH OF THE AREA. WHILE LARGE SCALE FORCING NOT
ALL THAT GREAT...INSTABILITY VALUES HIGHER AND WITH TEMPS ALOFT
COOLER CINH VALUES WEAKER. MOISTURE RETURN CONCERNS STILL EXIST FOR
PERIOD AS THERE DOES NOT APPEAR TO BE ANY MEANINGFUL MOISTURE
RETURN...SO THINK LIMITING POPS TO THE 20 PERCENT RANGE IN ORDER.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 244 AM MDT WED MAY 16 2012
THURSDAY NIGHT-FRIDAY NIGHT...WEAK SHORT WAVE RIDGING WILL BUILD
OVER THE AREA DURING THE EVENING HOURS...BRINGING AN END TO ANY
PRECIP CHANCES DURING THE OVERNIGHT HOURS. NEXT SHORT WAVE TROUGH
WILL MOVE OVER THE FOUR CORNERS AREA AND INTO COLORADO BY FRIDAY
NIGHT. WHILE LARGE SCALE FORCING FOR ASCENT WITH UPPER TROUGH NOT
EXPECTED TO INFLUENCE THE AREA DIRECTLY UNTIL AROUND 12Z WHEN COLD
FRONT ENTERS CWA...HAVE SOME CONCERNS ABOUT POTENTIAL FOR
THUNDERSTORMS ALONG SFC TROUGH/DRYLINE LATE FRIDAY AFTERNOON AND
EVENING. STRONGEST LOW LEVEL CONVERGENCE EXPECTED TO THE SOUTH OF
SFC LOW CENTERED OVER NORTHEASTERN COLORADO/NEB PANHANDLE. MOISTURE
ADVECTION LOOKS A BIT STRONGER THAN PREVIOUS SYSTEM WITH TDS IN THE
MID 40S TO LOW 50S EXPECTED EAST OF DRY LINE. WHILE THERE IS A SMALL
POTENTIAL FOR STORMS...THINK PROBABILITIES SHOULD REMAIN FAIRLY LOW
FOR THE TIME BEING AS HIGHEST TDS/INSTABILITY WILL BE WELL TO THE
EAST OF BEST SFC CONVERGENCE AND WITH LARGE SCALE FORCING NOT
BECOMING STRONG UNTIL AROUND 12Z THINK SFC FEATURES WILL BE PRIMARY
MEANS FOR ANY CONVECTIVE INITIATION. WINDS INCREASE SHARPLY DURING
THE DAY FRIDAY...ESPECIALLY TO THE EAST OF SFC TROUGH INCREASING
SHARPLY AROUND 00Z. STILL A FAIRLY LARGE DISCREPANCY ON HOW STRONG
WINDS ALOFT WILL BE...BUT THERE LOOKS TO BE AT LEAST SOME POTENTIAL
FOR ADVISORY TYPE WINDS LATE FRIDAY AFTERNOON AND EARLY EVENING.
WINDS SHOULD REMAIN STRONG/GUSTY DURING THE OVERNIGHT HOURS AHEAD OF
COLD FRONT KEEPING LOWS MUCH WARMER THAN THE PAST FEW DAYS WITH MANY
LOCATIONS SEEING LOWS STAY IN THE 60S.
A STRONG COLD FRONT WILL MOVE THROUGH THE REGION SATURDAY MORNING
AHEAD OF A SHORTWAVE TROUGH THAT WILL MOVE THROUGH THE CENTRAL
ROCKIES AND INTO KANSAS BEFORE SWINGING UP INTO NEBRASKA BY SATURDAY
EVENING. PRECIPITATION CHANCES WILL INCREASE AS THE FRONT MOVES
THROUGH THE REGION...WITH BEST CHANCES ACROSS THE NORTHERN HALF OF
THE CWA. DRY SLOT APPEARS TO DEVELOP AND WILL KEEP PRECIPITATION
CHANCES LOW ACROSS PARTS OF SOUTHEAST COLORADO AND SOUTHWEST KANSAS.
COOLER AIR WILL MOVE IN BEHIND THE FRONT WITH A GRADUAL WARMING
THROUGH NEXT WEEK. ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH THE
REGION ON SUNDAY...BUT WITH HIGHER SURFACE DEWPOINTS EXPECTED TO BE
MUCH FURTHER EASTWARD ACROSS EASTERN KANSAS...AM NOT EXPECTING
THUNDERSTORMS TO DEVELOP SUNDAY AFTERNOON. BY EARLY NEXT
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 536 AM MDT WED MAY 16 2012
VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS AS UPPER LEVEL
DISTURBANCE APPROACHES FROM THE WEST. PERIOD OF LLWS AT GLD SHOULD
END QUICKLY THIS MORNING AS SFC WINDS INCREASE WITH HEATING.
SOUTHEASTERLY WINDS WILL GRADUALLY SHIFT TO THE SOUTH AND INCREASE
TO AROUND 20KTS...MAINLY AFTER 17Z. THERE IS A SMALL CHANCE FOR
THUNDERSTORMS BTWN 00Z AND 06Z...BUT THESE SHOULD REMAIN WELL TO
THE WEST OF TAF SITES.
&&
.FIRE WEATHER...
ISSUED AT 236 AM MDT WED MAY 16 2012
CRITICAL FIRE WEATHER CONDITIONS EXPECTED TODAY AS A DEVELOPING
SURFACE TROUGH BRINGS SOUTHERLY WINDS OF 15 TO 25 MPH TO THE AREA
AND AFTERNOON HUMIDITIES FALL TO LESS THAN 15 PERCENT ACROSS MUCH
OF THE AREA. BASED ON LATEST FUEL REPORTS AND AVAILABLE SATELLITE
GREENESS DATA...IT APPEARS THAT WITH THE EXCEPTION OF PORTIONS OF
EASTERN COLORADO AND ADJACENT AREAS OF NORTHWEST KANSAS WIDESPREAD
CRITICAL FUELS ARE NOT AVAILABLE.
AFTERNOON HUMIDITIES WILL FALL TO THE 10 TO 20 PERCENT RANGE EACH
AFTERNOON THROUGH FRIDAY. WINDS ARE EXPECTED TO REMAIN CRITICAL
VALUES ON THURSDAY...BUT WILL INCREASE THROUGH THE DAY FRIDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING UNTIL 8 PM MDT /9 PM CDT/ THIS EVENING FOR
KSZ001-013-027.
CO...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ252>254.
NE...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR NEZ079.
&&
$$
UPDATE...DR
SHORT TERM...JRM
LONG TERM...JRM/PM
AVIATION...JRM
FIRE WEATHER...JRM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
118 PM EDT WED MAY 16 2012
.SYNOPSIS...
ISSUED AT 518 AM EDT WED MAY 16 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE FROM
THE ROCKIES INTO SASK AND A DOWNSTREAM TROUGH FROM HUDSON BAY INTO
THE CNTRL GREAT LAKES RESULTING IN NW FLOW THROUGH UPPER MI. AT THE
SFC...HIGH PRES FROM MANITOBA INTO WRN MN WAS BUILDING INTO THE WRN
GREAT LAKES. SUBSIDENCE AND DRY ADVECTION IN THE WAKE OF THE MID
LEVEL TROUGH HAS BROUGHT CLEAR SKIES TO THE AREA ALONG WITH
DIMINISHING WINDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 518 AM EDT WED MAY 16 2012
TODAY...SUNSHINE AND MIXING IN THE VERY DRY AIRMASS (PWAT VALUES
DOWN TO NEAR 0.25 INCH) OVER THE AREA WILL BOOST TEMPS INTO THE
LOWER TO MID 60S BUT PUSH DEWPOINTS DOWN TO NEAR 20 OVER INLAND
LOCATIONS THIS AFTERNOON. THIS WILL RESULT IN RH VALUES IN THE 20 TO
25 PCT RANGE. FORTUNATELY WINDS WILL BE RELATIVELY LIGHT...ONLY
INCREASING INTO THE 10 TO 15 MPH RANGE THIS AFTERNOON.
TONIGHT...AS THE MID LEVEL RIDGE EDGES TO THE EAST...DOWNSTREAM WAA
AND 300K-305K ISENTROPIC LIFT WILL BRING AN INCREASE IN MID LEVEL
CLOUDS FROM NW ONTARIO INTO UPPER MI. HOWEVER...LIGHT WINDS AND
MAINLY CLEAR SKIES TIL LATE NIGHT OVER THE EAST WILL RESULT IN
DECENT RADIATIONAL COOLING WITH TEMPS FALLING INTO THE LOWER 30S.
A FROST ADVY MAY BE NEEDED FOR THE INTERIOR EAST HALF...ESPECIALLY
IF THERE IS A TREND TOWARD LATER INCREASE IN CLOUDS.
THURSDAY...EXPECT THE POSITION OF THE 850 MB WARM FRONT AND GREATER
LOW LEVEL THETA-E ADVECTION...PER NAM/GFS/ECMWF...TO REMAIN FAR
ENOUGH TO THE SOUTH AND WEST TO KEEP BEST PCPN CHANCES OVER NRN
MN AND NRN WI. HOWEVER...SOME SHRA MAY BRUSH MAINLY THE SW PORTION
OF THE CWA. CLOUD COVER SHOULD BE THICK ENOUGH TO KEEP TEMPS INTO
THE MID TO UPPER 60S...EVEN AS 850 MB TEMPS CLIMB INTO THE 7C TO 10C
RANGE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 518 AM EDT WED MAY 16 2012
NAM STARTS OFF WITH A 500 MB TROUGH OVER THE WESTERN U.S. AND
SHORTWAVE IN THE CENTRAL PLAINS 00Z FRI WITH RIDGING INTO THE UPPER
MISSISSIPPI RIVER VALLEY AND TROUGHING IN THE SERN U.S. AND ALSO IN
NEW ENGLAND. UPPER LEVEL RIDGING BUILDS INTO THE UPPER GREAT LAKES
THIS PERIOD.
NAM BRINGS THIS SHORTWAVE NORTHEAST FRIDAY WITH 850-500 MB Q-VECTOR
CONVERGENCE AND DEEPER MOISTURE MOVING THROUGH THE AREA BEFORE BOTH
GET PUSHED NORTH FRIDAY NIGHT. NAM ALSO SHOWS SOME ISENTROPIC LIFT
AND LIMITED MOISTURE THU NIGHT WITH A WARM FRONT MOVING THROUGH THE
AREA BEFORE THE LIFT AND MOISTURE PUSH NORTH ON FRIDAY. GFS SHOWS
ABOUT THE SAME THING FOR ISENTROPIC LIFT ON I300K-I310K SURFACES AND
MOISTURE THU NIGHT INTO FRI. GFS AND ECMWF ALSO SHOW 850-500 MB
Q-VECTOR CONVERGENCE OVER THE AREA THROUGH 12Z SAT. WILL PUT IN
CHANCE TO SLIGHT CHANCE POPS FOR THIS WARM FRONT THU NIGHT THROUGH
FRIDAY NIGHT ACROSS THE AREA. BEST CHANCES FOR PCPN WILL BE ACROSS
THE WEST AND LOWEST IN THE EAST AWAY FROM THE BETTER MOISTURE AND
DYNAMICS. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES.
IN THE EXTENDED...ECMWF SHOWS A 500 MB RIDGE OVER THE UPPER GREAT
LAKES WITH TROUGHING IN THE WESTERN U.S. 12Z WITH A TROUGH IN THE
EASTERN U.S. AND A WEAK CLOSED 500 MB LOW OVER THE SERN U.S. PATTERN
CHANGES LITTLE 12Z SUNDAY BEFORE THE TROUGH IN THE WESTERN U.S.
MOVES INTO THE UPPER GREAT LAKES SUN NIGHT THROUGH TUE. GFS SHOWS
ABOUT THE SAME THING THROUGH SUNDAY. WHAT THIS WILL MEAN IS A VERY
WARM PERIOD AT THE START OF THE WEEKEND...THEN A COOL DOWN INTO
EARLY NEXT WEEK. TEMPERATURES WILL STILL BE AT OR ABOVE NORMAL
THOUGH. WITH THE UPPER LEVEL TROUGH REMAINING INTO TUE...AFTER
CHANCE TO LIKELY POPS ON SUNDAY WITH THE COLD FRONT...SLIGHT CHANCE
POPS FOR MONDAY INTO TUESDAY STILL SEEM WARRANTED. DID BUMP HIGHS UP
A BIT ON SATURDAY AS PLENTY OF SUNSHINE AND 850 MB TEMPERATURES TO
14C TO 16C...THIS WOULD GIVE HIGHS IN THE LOWER TO MID 80S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 117 PM EDT WED MAY 16 2012
VFR CEILINGS AND VIS EXPECTED OVER THE NEXT 24 HOURS...AS HIGH
CLOUDS INVADE FROM THE NORTHWEST. AFTERNOON GUSTS NEAR 20KTS WILL BE
POSSIBLE AT CMX AND SAW TODAY...AND WILL BE POSSIBLE MAINLY AT IWD
AND SAW WITH A SOUTHERLY PUSH ON THURSDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EDT WED MAY 16 2012
WINDS WILL BE BELOW 25 KNOTS THROUGH THE PERIOD. A HIGH PRESSURE
RIDGE WILL BUILD INTO THE REGION TODAY THROUGH THURSDAY. A LOW
PRESSURE TROUGH WILL APPROACH FROM THE PLAINS AND PUSH A WARM FRONT
ACROSS THE AREA THURSDAY NIGHT INTO FRIDAY. A COLD FRONT WILL MOVE
THROUGH THE UPPER GREAT LAKES ON SUNDAY WITH COOLER HIGH PRESSURE
BUILDING BACK IN FOR EARLY NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...07
AVIATION...KF
MARINE...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
628 AM EDT WED MAY 16 2012
.SYNOPSIS...
ISSUED AT 518 AM EDT WED MAY 16 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE FROM
THE ROCKIES INTO SASK AND A DOWNSTREAM TROUGH FROM HUDSON BAY INTO
THE CNTRL GREAT LAKES RESULTING IN NW FLOW THROUGH UPPER MI. AT THE
SFC...HIGH PRES FROM MANITOBA INTO WRN MN WAS BUILDING INTO THE WRN
GREAT LAKES. SUBSIDENCE AND DRY ADVECTION IN THE WAKE OF THE MID
LEVEL TROUGH HAS BROUGHT CLEAR SKIES TO THE AREA ALONG WITH
DIMINISHING WINDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 518 AM EDT WED MAY 16 2012
TODAY...SUNSHINE AND MIXING IN THE VERY DRY AIRMASS (PWAT VALUES
DOWN TO NEAR 0.25 INCH) OVER THE AREA WILL BOOST TEMPS INTO THE
LOWER TO MID 60S BUT PUSH DEWPOINTS DOWN TO NEAR 20 OVER INLAND
LOCATIONS THIS AFTERNOON. THIS WILL RESULT IN RH VALUES IN THE 20 TO
25 PCT RANGE. FORTUNATELY WINDS WILL BE RELATIVELY LIGHT...ONLY
INCREASING INTO THE 10 TO 15 MPH RANGE THIS AFTERNOON.
TONIGHT...AS THE MID LEVEL RIDGE EDGES TO THE EAST...DOWNSTREAM WAA
AND 300K-305K ISENTROPIC LIFT WILL BRING AN INCREASE IN MID LEVEL
CLOUDS FROM NW ONTARIO INTO UPPER MI. HOWEVER...LIGHT WINDS AND
MAINLY CLEAR SKIES TIL LATE NIGHT OVER THE EAST WILL RESULT IN
DECENT RADIATIONAL COOLING WITH TEMPS FALLING INTO THE LOWER 30S.
A FROST ADVY MAY BE NEEDED FOR THE INTERIOR EAST HALF...ESPECIALLY
IF THERE IS A TREND TOWARD LATER INCREASE IN CLOUDS.
THURSDAY...EXPECT THE POSITION OF THE 850 MB WARM FRONT AND GREATER
LOW LEVEL THETA-E ADVECTION...PER NAM/GFS/ECMWF...TO REMAIN FAR
ENOUGH TO THE SOUTH AND WEST TO KEEP BEST PCPN CHANCES OVER NRN
MN AND NRN WI. HOWEVER...SOME SHRA MAY BRUSH MAINLY THE SW PORTION
OF THE CWA. CLOUD COVER SHOULD BE THICK ENOUGH TO KEEP TEMPS INTO
THE MID TO UPPER 60S...EVEN AS 850 MB TEMPS CLIMB INTO THE 7C TO 10C
RANGE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 518 AM EDT WED MAY 16 2012
NAM STARTS OFF WITH A 500 MB TROUGH OVER THE WESTERN U.S. AND
SHORTWAVE IN THE CENTRAL PLAINS 00Z FRI WITH RIDGING INTO THE UPPER
MISSISSIPPI RIVER VALLEY AND TROUGHING IN THE SERN U.S. AND ALSO IN
NEW ENGLAND. UPPER LEVEL RIDGING BUILDS INTO THE UPPER GREAT LAKES
THIS PERIOD.
NAM BRINGS THIS SHORTWAVE NORTHEAST FRIDAY WITH 850-500 MB Q-VECTOR
CONVERGENCE AND DEEPER MOISTURE MOVING THROUGH THE AREA BEFORE BOTH
GET PUSHED NORTH FRIDAY NIGHT. NAM ALSO SHOWS SOME ISENTROPIC LIFT
AND LIMITED MOISTURE THU NIGHT WITH A WARM FRONT MOVING THROUGH THE
AREA BEFORE THE LIFT AND MOISTURE PUSH NORTH ON FRIDAY. GFS SHOWS
ABOUT THE SAME THING FOR ISENTROPIC LIFT ON I300K-I310K SURFACES AND
MOISTURE THU NIGHT INTO FRI. GFS AND ECMWF ALSO SHOW 850-500 MB
Q-VECTOR CONVERGENCE OVER THE AREA THROUGH 12Z SAT. WILL PUT IN
CHANCE TO SLIGHT CHANCE POPS FOR THIS WARM FRONT THU NIGHT THROUGH
FRIDAY NIGHT ACROSS THE AREA. BEST CHANCES FOR PCPN WILL BE ACROSS
THE WEST AND LOWEST IN THE EAST AWAY FROM THE BETTER MOISTURE AND
DYNAMICS. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES.
IN THE EXTENDED...ECMWF SHOWS A 500 MB RIDGE OVER THE UPPER GREAT
LAKES WITH TROUGHING IN THE WESTERN U.S. 12Z WITH A TROUGH IN THE
EASTERN U.S. AND A WEAK CLOSED 500 MB LOW OVER THE SERN U.S. PATTERN
CHANGES LITTLE 12Z SUNDAY BEFORE THE TROUGH IN THE WESTERN U.S.
MOVES INTO THE UPPER GREAT LAKES SUN NIGHT THROUGH TUE. GFS SHOWS
ABOUT THE SAME THING THROUGH SUNDAY. WHAT THIS WILL MEAN IS A VERY
WARM PERIOD AT THE START OF THE WEEKEND...THEN A COOL DOWN INTO
EARLY NEXT WEEK. TEMPERATURES WILL STILL BE AT OR ABOVE NORMAL
THOUGH. WITH THE UPPER LEVEL TROUGH REMAINING INTO TUE...AFTER
CHANCE TO LIKELY POPS ON SUNDAY WITH THE COLD FRONT...SLIGHT CHANCE
POPS FOR MONDAY INTO TUESDAY STILL SEEM WARRANTED. DID BUMP HIGHS UP
A BIT ON SATURDAY AS PLENTY OF SUNSHINE AND 850 MB TEMPERATURES TO
14C TO 16C...THIS WOULD GIVE HIGHS IN THE LOWER TO MID 80S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 628 AM EDT WED MAY 16 2012
ALTHOUGH THERE WL BE A GRADUAL INCRS IN MID AND HI CLDS
LATER...EXPECT VFR CONDITIONS AND LIGHT WINDS THIS FCST PERIOD WITH
DRY HI PRES DOMINATING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EDT WED MAY 16 2012
WINDS WILL BE BELOW 25 KNOTS THROUGH THE PERIOD. A HIGH PRESSURE
RIDGE WILL BUILD INTO THE REGION TODAY THROUGH THURSDAY. A LOW
PRESSURE TROUGH WILL APPROACH FROM THE PLAINS AND PUSH A WARM FRONT
ACROSS THE AREA THURSDAY NIGHT INTO FRIDAY. A COLD FRONT WILL MOVE
THROUGH THE UPPER GREAT LAKES ON SUNDAY WITH COOLER HIGH PRESSURE
BUILDING BACK IN FOR EARLY NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...07
AVIATION...07
MARINE...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
520 AM EDT WED MAY 16 2012
.SYNOPSIS...
ISSUED AT 518 AM EDT WED MAY 16 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE FROM
THE ROCKIES INTO SASK AND A DOWNSTREAM TROUGH FROM HUDSON BAY INTO
THE CNTRL GREAT LAKES RESULTING IN NW FLOW THROUGH UPPER MI. AT THE
SFC...HIGH PRES FROM MANITOBA INTO WRN MN WAS BUILDING INTO THE WRN
GREAT LAKES. SUBSIDENCE AND DRY ADVECTION IN THE WAKE OF THE MID
LEVEL TROUGH HAS BROUGHT CLEAR SKIES TO THE AREA ALONG WITH
DIMINISHING WINDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 518 AM EDT WED MAY 16 2012
TODAY...SUNSHINE AND MIXING IN THE VERY DRY AIRMASS (PWAT VALUES
DOWN TO NEAR 0.25 INCH) OVER THE AREA WILL BOOST TEMPS INTO THE
LOWER TO MID 60S BUT PUSH DEWPOINTS DOWN TO NEAR 20 OVER INLAND
LOCATIONS THIS AFTERNOON. THIS WILL RESULT IN RH VALUES IN THE 20 TO
25 PCT RANGE. FORTUNATELY WINDS WILL BE RELATIVELY LIGHT...ONLY
INCREASING INTO THE 10 TO 15 MPH RANGE THIS AFTERNOON.
TONIGHT...AS THE MID LEVEL RIDGE EDGES TO THE EAST...DOWNSTREAM WAA
AND 300K-305K ISENTROPIC LIFT WILL BRING AN INCREASE IN MID LEVEL
CLOUDS FROM NW ONTARIO INTO UPPER MI. HOWEVER...LIGHT WINDS AND
MAINLY CLEAR SKIES TIL LATE NIGHT OVER THE EAST WILL RESULT IN
DECENT RADIATIONAL COOLING WITH TEMPS FALLING INTO THE LOWER 30S.
A FROST ADVY MAY BE NEEDED FOR THE INTERIOR EAST HALF...ESPECIALLY
IF THERE IS A TREND TOWARD LATER INCREASE IN CLOUDS.
THURSDAY...EXPECT THE POSITION OF THE 850 MB WARM FRONT AND GREATER
LOW LEVEL THETA-E ADVECTION...PER NAM/GFS/ECMWF...TO REMAIN FAR
ENOUGH TO THE SOUTH AND WEST TO KEEP BEST PCPN CHANCES OVER NRN
MN AND NRN WI. HOWEVER...SOME SHRA MAY BRUSH MAINLY THE SW PORTION
OF THE CWA. CLOUD COVER SHOULD BE THICK ENOUGH TO KEEP TEMPS INTO
THE MID TO UPPER 60S...EVEN AS 850 MB TEMPS CLIMB INTO THE 7C TO 10C
RANGE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 518 AM EDT WED MAY 16 2012
NAM STARTS OFF WITH A 500 MB TROUGH OVER THE WESTERN U.S. AND
SHORTWAVE IN THE CENTRAL PLAINS 00Z FRI WITH RIDGING INTO THE UPPER
MISSISSIPPI RIVER VALLEY AND TROUGHING IN THE SERN U.S. AND ALSO IN
NEW ENGLAND. UPPER LEVEL RIDGING BUILDS INTO THE UPPER GREAT LAKES
THIS PERIOD.
NAM BRINGS THIS SHORTWAVE NORTHEAST FRIDAY WITH 850-500 MB Q-VECTOR
CONVERGENCE AND DEEPER MOISTURE MOVING THROUGH THE AREA BEFORE BOTH
GET PUSHED NORTH FRIDAY NIGHT. NAM ALSO SHOWS SOME ISENTROPIC LIFT
AND LIMITED MOISTURE THU NIGHT WITH A WARM FRONT MOVING THROUGH THE
AREA BEFORE THE LIFT AND MOISTURE PUSH NORTH ON FRIDAY. GFS SHOWS
ABOUT THE SAME THING FOR ISENTROPIC LIFT ON I300K-I310K SURFACES AND
MOISTURE THU NIGHT INTO FRI. GFS AND ECMWF ALSO SHOW 850-500 MB
Q-VECTOR CONVERGENCE OVER THE AREA THROUGH 12Z SAT. WILL PUT IN
CHANCE TO SLIGHT CHANCE POPS FOR THIS WARM FRONT THU NIGHT THROUGH
FRIDAY NIGHT ACROSS THE AREA. BEST CHANCES FOR PCPN WILL BE ACROSS
THE WEST AND LOWEST IN THE EAST AWAY FROM THE BETTER MOISTURE AND
DYNAMICS. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES.
IN THE EXTENDED...ECMWF SHOWS A 500 MB RIDGE OVER THE UPPER GREAT
LAKES WITH TROUGHING IN THE WESTERN U.S. 12Z WITH A TROUGH IN THE
EASTERN U.S. AND A WEAK CLOSED 500 MB LOW OVER THE SERN U.S. PATTERN
CHANGES LITTLE 12Z SUNDAY BEFORE THE TROUGH IN THE WESTERN U.S.
MOVES INTO THE UPPER GREAT LAKES SUN NIGHT THROUGH TUE. GFS SHOWS
ABOUT THE SAME THING THROUGH SUNDAY. WHAT THIS WILL MEAN IS A VERY
WARM PERIOD AT THE START OF THE WEEKEND...THEN A COOL DOWN INTO
EARLY NEXT WEEK. TEMPERATURES WILL STILL BE AT OR ABOVE NORMAL
THOUGH. WITH THE UPPER LEVEL TROUGH REMAINING INTO TUE...AFTER
CHANCE TO LIKELY POPS ON SUNDAY WITH THE COLD FRONT...SLIGHT CHANCE
POPS FOR MONDAY INTO TUESDAY STILL SEEM WARRANTED. DID BUMP HIGHS UP
A BIT ON SATURDAY AS PLENTY OF SUNSHINE AND 850 MB TEMPERATURES TO
14C TO 16C...THIS WOULD GIVE HIGHS IN THE LOWER TO MID 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 139 AM EDT WED MAY 16 2012
ALTHOUGH THERE WL BE A GRADUAL INCRS IN HI CLDS LATER...EXPECT VFR
CONDITIONS AND LIGHT WINDS THIS FCST PERIOD WITH DRY HI PRES
DOMINATING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EDT WED MAY 16 2012
WINDS WILL BE BELOW 25 KNOTS THROUGH THE PERIOD. A HIGH PRESSURE
RIDGE WILL BUILD INTO THE REGION TODAY THROUGH THURSDAY. A LOW
PRESSURE TROUGH WILL APPROACH FROM THE PLAINS AND PUSH A WARM FRONT
ACROSS THE AREA THURSDAY NIGHT INTO FRIDAY. A COLD FRONT WILL MOVE
THROUGH THE UPPER GREAT LAKES ON SUNDAY WITH COOLER HIGH PRESSURE
BUILDING BACK IN FOR EARLY NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...07
AVIATION...JLB
MARINE...07
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1129 PM CDT TUE MAY 15 2012
.AVIATION... /06Z TAF ISSUANCE/
NOT TOO MANY CONCERNS AHEAD AS A LARGE HIGH PRESSURE SYSTEM PASSES
ACROSS THE TAF SITES. VFR CONDITIONS TO PREVAIL. LIGHT NORTH WINDS
OVERNIGHT WILL BECOME SOUTH FOR THE MN TAF SITES AND WEST FOR THE
WI ONES. WINDS WILL INCREASE DURING THE AFTERNOON AT KAXN AND
KRWF WITH GUSTS OF 18-20 KNOTS POSSIBLE FOR A FEW HOURS.
KMSP...VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD. LIGHT NORTH
WINDS OVERNIGHT WILL VEER TO THE EAST WEDNESDAY MORNING AND THEN
BECOME SOUTH LESS THAN 10 KNOTS IN THE AFTERNOON.
OUTLOOK...
THU-FRI...SLIGHT CHANCE OF SHRA/TSRA...MVFR CEILINGS POSSIBLE.
SAT-SUN...SHRA/TSRA LIKELY WITH MVFR/IFR POSSIBLE.
&&
.DISCUSSION... /ISSUED 312 PM CDT TUE MAY 15 2012/
A FAIRLY PROGRESSIVE UPPER LEVEL PATTERN WILL BE THE RULE ACROSS
THE NORTHERN CONUS OVER THE UPCOMING WEEK. LATEST WATER VAPOR
IMAGERY AND RAP ANALYSIS SHOW A BROAD RIDGE OVER THE WEST... WITH
TROUGHING OVER THE EAST. A HEALTHY SHORTWAVE CAN BE SEEN ROTATING
SOUTHEAST ACROSS THE NORTHERN GREAT LAKES AT THE CURRENT TIME.
THIS FEATURE IS HELPING TO ENHANCE THE CU FIELD ACROSS NORTHEAST
MINNESOTA AND NORTHERN WISCONSIN... BUT ANY SHRA ARE STAYING WELL
NORTH AND EAST OF OUR AREA. THE WESTERN RIDGE WILL MOVE EAST OVER
THE NEXT FEW DAYS... GENERALLY BRINGING DRY WEATHER AND A WARMING
TREND. HOWEVER... CHANCES FOR SHRA/TSRA WILL STEADILY INCREASE
DURING THE SECOND HALF OF THE WEEK INTO THE WEEKEND... WITH AN
UPPER TROUGH EVENTUALLY PUSHING THROUGH TOWARD THE END OF THE
WEEKEND... WHICH WILL HELP PUSH A SURFACE LOW AND FRONTAL BOUNDARY
ACROSS THE REGION. FAVORED THE NAM FOR THE SHORT TERM DETAILS...
THEN TRENDED TOWARD A BLEND OF THE PREVIOUS FORECAST AND ECMWF...
WHICH WAS A BIT SLOWER TO KICK THE RIDGE EASTWARD. THE LATEST
ECMWF IS A BIT FASTER HOWEVER... WHICH MAKES THE WEEKEND FORECAST
TRICKY IN TERMS OF PINPOINTING WHEN PCPN IS MOST LIKELY.
SURFACE RIDGE WILL CONTINUE TO BUILD SOUTHEAST ACROSS THE AREA
TONIGHT... FURTHER DRYING OUT DEWPOINTS THROUGH THE EARLY
EVENING... WITH A REASONABLY COOL NIGHT EXPECTED FOR THE OVERNIGHT
HOURS. THE WESTERN PART OF THE AREA SHOULD MANAGE TO GET ON THE
BACKSIDE OF THE RIDGE BY TOMORROW AFTERNOON... WITH SOME RETURN
FLOW WORKING INTO THAT AREA BY EVENING. A BETTER LOW LEVEL JET AND
WARM ADVECTION LOOK TO SETUP ACROSS THE AREA LATER WEDNESDAY
NIGHT AS LOW PRESSURE EDGED OUT INTO THE HIGH PLAINS. A LOOK AT
FORECAST 850-500MB DIFFERENTIAL THETA-E VALUES... 850MB THETA-E
ADVECTION... AND ISENTROPIC ASCENT ON THE 305K SURFACE SUGGEST
THAT ELEVATED SHRA/TSRA MAY INITIALLY GET GOING OVER THE NORTH
CENTRAL PART OF THE AREA... BUT SHOULD WORK ITS WAY SOUTHEAST
THROUGH THE OVERNIGHT AS SATURATION OCCURS SOUTHWARD ALONG THE
ELEVATED FRONTAL BOUNDARY. SOME ACTIVITY SHOULD REMAIN FOCUSED
NEAR THE FRONTAL BOUNDARY THROUGH THE DAY ON THURSDAY INTO
THURSDAY NIGHT AS WARM ADVECTION PERSISTS IN AN AREA OF CONVECTIVE
INSTABILITY. HOWEVER... BY FRIDAY THROUGH FRIDAY NIGHT THE FOCUS OF
THIS ACTIVITY LOOKS LIKE IT SHOULD SHIFT NORTHEAST OF MOST OF THE
AREA... SO TRIMMED BACK POPS DURING THAT TIME FRAME TO MAINLY
INCLUDE ONLY THE FAR NORTHERN PORTION OF THE CWFA. BY SATURDAY WE
WILL START TO FEEL THE INFLUENCE OF THE APPROACHING SURFACE FRONT
AS THE AIRMASS ACROSS THE REGION CONTINUES TO DESTABILIZE... SO
INCREASED POPS ACROSS MUCH OF THE AREA FROM WEST TO EAST. THE
BOUNDARY ITSELF LOOKS TO MOVE ACROSS THE REGION SATURDAY NIGHT OR
EARLY SUNDAY... BUT AT THIS POINT THAT TIMING COULD EASILY SHIFT
FOR 12-24 HOURS... WHICH WILL CERTAINLY HAVE AN IMPACT ON WHEN
WIDESPREAD SHRA/TSRA IS MOST LIKELY... AS WELL AS WHETHER MUCH IF
ANY SEVERE WEATHER WILL OCCUR. THINGS LOOK TO DRY OUT MONDAY AND
TUESDAY IN THE WAKE OF THE FRONT AND UPPER TROUGH... WITH HIGH
PRESSURE QUICKLY SETTLING IN ON MONDAY... THEN THE PROGRESSIVE
PATTERN BRINGING RETURN FLOW BACK INTO THE REGION BY TUESDAY
AFTERNOON.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/TRH
AREA FORECAST DISCUSSION
NWS GLASGOW MT
916 AM MDT WED MAY 16 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH FRIDAY...
ONLY MINOR TWEAK TO FORECAST FOR THE MORNING UPDATE. INCREASED
CLOUD COVER A LITTLE BIT TO ACCOUNT FOR SOME CUMULUS AND STRATUS
OVER MUCH OF THE AREA. QUITE WARM TODAY. HRRR MODEL SHOWS SOME
THUNDERSHOWERS INITIATING OVER THE ROCKY MOUNTAINS THIS AFTERNOON.
SOME OF THESE SHOWERS MAY APPROACH THE AREA THIS EVENING OR
TONIGHT...HOWEVER...FORCING FROM SURFACE HEATING WILL BE IN
DECLINE BY THEN AND STORMS ARE EXPECTED TO DIE OUT BEFORE REACHING
OUR AREA. CHANCES FOR PRECIPITATION ARE MUCH BETTER LATE THURSDAY
INTO FRIDAY AS TROUGH PASSES OVER THE AREA. MARTIN
PREVIOUS DISCUSSION...
UPPER RIDGE PROGRESSING EASTWARD WILL BRING CONTINUED DRY YET
WARMER WEATHER TO NORTHEAST MONTANA TODAY. LEE TROF WILL ALSO MOVE
EASTWARD SWITCHING THE LOW LEVEL FLOW FROM SOUTHEAST TO WEST. WEAK
CLOSED LOW MOVING ACROSS WYOMING WILL PUSH SOME MOISTURE AND
INSTABILITY INTO SOUTHERN MONTANA...WILL HELP DEVELOP
THUNDERSTORMS OVER THE HIGHER TERRAIN OF SOUTH CENTRAL MONTANA
LATE THIS AFTERNOON.
COLD FRONT MOVES THROUGH THE STATE LATE TONIGHT AND AS UPPER FLOW
TURNS SOUTHWEST...MOISTURE WILL BE INCREASING. BEST PUSH OF
MOISTURE AND INSTABILITY INTO MONTANA NOT EXPECT TO OCCUR UNTIL
THURSDAY NIGHT AS UPPER TROF DIGS ACROSS THE GREAT BASIN. COOLER
AND WETTER WEATHER WILL CONTINUE INTO FRIDAY. EBERT
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
AN UPPER PATTERN OF TROUGH...THEN RIDGE...THEN TROUGH. MODELS AGREE
WITH THIS...SO WEATHER IS STRAIGHTFORWARD WITH A THREAT OF SHOWERS
AND SOMEWHAT COOL WEATHER BEGINNING AND ENDING OF THE PERIOD...AND
A SUNNY AND WARM PERIOD IN THE MIDDLE.
A VERY ELONGATED UPPER TROUGH MOVES ACROSS THE AREA SATURDAY.
MOST SHOWER ACTIVITY IS FRI NIGHT THOUGH AS MODELS INDICATE
DOWNSLOPE DRYING ARRIVING SATURDAY. COOL TEMPS WITH GFS AND CMC
GEM INDICATING 850MB TEMPS AS LOW AS 2C IN OUR NW SAT MORN...AND WITH
COOL ADVECTION CAUSING SOMEWHAT WINDY WEATHER AS WELL.
THE UPPER RIDGE THEN BRINGS CLEAR SKIES AND A STRONG WARMING TREND
FOR SUNDAY/MONDAY. THICKNESSES RISE TO THE LOWER 570S DM...
INDICATING 80S FOR HIGHS.
THE END OF THE PERIOD WITH ANOTHER APPROACHING TROUGH IS EXPECTEDLY
FUZZY ON DETAILS...LOCATION OF SHOWER THREATS AND DRY
DOWNSLOPING...BUT REASONABLE TO HAVE SLIGHT CHANCE POPS FOR AT
LEAST 2 OR 3 FORECAST PERIODS...AND ALSO TO START A COOLING TREND.
SIMONSEN
&&
.AVIATION...
VFR WITH ONLY SCATTERED CLOUDS ABOVE 10K FT AGL. LIGHT SOUTHEAST
WINDS WILL SLOWLY VEER AROUND TO THE WEST DURING THE AFTERNOON.
HICKS/SIMONSEN
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
616 PM CDT THU MAY 17 2012
.AVIATION...00Z TAF. MAIN CONCERN FOR THE TAF PERIOD IS STRONG AND
GUSTY SOUTHERLY WINDS. SOUTH WINDS HAVE BEEN STRONG ALL DAY AND
ALTHOUGH WIND SPEEDS WILL SUBSIDE SOMEWHAT AFTER DARK...WINDS WILL
REMAIN STEADY THROUGH THE NIGHT. WIND SPEEDS WILL INCREASE FURTHER
ON FRIDAY WITH DEEP MIXING EXPECTED WITH WIND GUSTS NEAR 35KTS
POSSIBLE AGAIN. CLOUDS WILL BE LIMITED TO THE MID AND HIGH LEVELS.
&&
.PREV DISCUSSION... /ISSUED 256 PM CDT THU MAY 17 2012/
SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT...WINDY CONDITIONS HAVE
DEVELOPED ACROSS MUCH OF THE FORECAST AREA TODAY AS DEEP MIXING HAS
BEEN REALIZED ALONG WITH A TIGHTENING PRESSURE GRADIENT IN RESPONSE
TO AN AREA OF SURFACE LOW PRESSURE TO OUR WEST. DO NOT EXPECT THESE
WINDS TO DIMINISH RAPIDLY THROUGH THE LATE AFTERNOON AND EARLY
EVENING HOURS AS PRESSURE GRADIENT WILL BE SLOW TO RELAX AND WINDS
FROM ALOFT WILL NOT DECOUPLE UNTIL AFTER SUNSET...SO WENT AHEAD AN
KEPT WIND ADVISORY GOING UNTIL 02Z THIS EVENING. IN ADDITION TO THE
WINDS...THERE REMAINS A SLIGHT CHANCE FOR A FEW THUNDERSTORMS THIS
EVENING ACROSS THE WESTERN FRINGES OF THE FORECAST AREA...AS FORCING
FROM WELL DEFINED UPPER LEVEL LOW MAY HELP INITIATE A FEW STORMS.
BOTH 12Z HRRR AND WRF HINT AT THIS TYPE OF DEVELOPMENT...BUT
CONFIDENCE NOT HIGH ENOUGH TO INCREASE COVERAGE AS INSTABILITY
REMAINS FAIRLY MARGINAL AND SIGNIFICANT COVERAGE IS NOT EXPECTED. IF
STORMS DO DEVELOP HOWEVER...MAIN THREAT APPEARS TO BE VERY GUSTY
WINDS AND SMALL HAIL.
OVERNIGHT...THE COMBINATION OF A SCT-BKN CIRRUS SHIELD AND CONTINUED
BREEZY SOUTHERLY WINDS SHOULD KEEP TEMPERATURES ELEVATED ABOVE
SEASONAL LEVELS...WITH LOW TEMPERATURES STRUGGLING TO FALL TO NEAR
60 IN MOST LOCATIONS.
WHILE DRY CONDITIONS ARE EXPECTED TO PREVAIL ON FRIDAY...ANOTHER
WINDY DAY APPEARS TO BE IN STORE ACROSS THE REGION AS THE PRESSURE
GRADIENT REMAINS TIGHT ACROSS THE REGION AND ONCE AGAIN GOOD MIXING
IS ANTICIPATED. WHILE A WIND ADVISORY MAY EVENTUALLY BECOME
NECESSARY ACROSS THE EASTERN HALF OF THE FORECAST AREA DURING THE
AFTERNOON HOURS...DECIDED TO HOLD OFF AT THIS POINT AS WE PRESENTLY
ALREADY HAVE AN ADVISORY HIGHLIGHTED FOR TODAY. DID HOWEVER INCLUDE
ADVISORY LEVEL WINDS FOR MUCH OF THE EASTERN HALF OF THE AREA DURING
THE AFTERNOON HOURS TOMORROW IN LATEST GRIDS. IN ADDITION TO
WINDS...EXPECT ANOTHER VERY WARM AFTERNOON FOR MID MAY...AND
INCREASED AFTERNOON TEMPS SEVERAL DEGREES IN RESPONSE TO WARMING 850
MB TEMPS AND A WARM START TO THE DAY ANTICIPATED.
LONG TERM...FRIDAY NIGHT THROUGH THURSDAY. THE PRIMARY WEATHER
FEATURES ARE A COLD FRONT THAT WILL TRACK ACROSS THE CWA ON SATURDAY
AND THEN A WESTERN CONUS UPPER TROUGH THAT DEVELOPS BY THE MIDDLE
OF NEXT WEEK.
FRIDAY NIGHT...MOST FORECAST MODELS ARE DRY FOR OUR FORECAST AREA
WITH THE BETTER CHANCE OF SHOWERS AND THUNDERSTORMS LOCATED ACROSS
PORTIONS OF WESTERN AND NORTHERN NEBRASKA. WILL CONTINUE WITH A
SLIGHT CHANCE OF THUNDERSTORMS ACROSS OUR NORTHWEST
ZONES...PRIMARILY NORTHWEST OF A HOLDREGE TO GRAND ISLAND LINE.
SATURDAY...THIS WILL BE OUR BEST CHANCE OF SEEING SHOWERS AND
THUNDERSTORMS WITHIN THE NEXT 5 DAYS...OR AT LEAST THROUGH TUESDAY.
AN UPPER LEVEL SHORT WAVE WILL SLIDE ACROSS THE CENTRAL PLAINS
ACCOMPANIED BY A FAIRLY STRONG SFC COLD FRONT. THE MORNING SHOULD BE
DRY...BUT SHOWERS AND THUNDERSTORMS WILL FORM ALONG AND BEHIND THE
COLD FRONT BY MID TO LATE AFTERNOON. THE COLD FRONT WILL PRIMARILY
TRACK ACROSS OUR CWA DURING THE AFTERNOON HOURS...BUT MAY NOT EXIT
OUR FAR SOUTHEASTERN ZONES UNTIL AROUND OR A BIT AFTER SUNSET. THERE
MAY BE TWO AREAS OF PRECIPITATION ASSOCIATED WITH THIS SYSTEM. THE
FIRST WILL BE AN AREA OF STRATIFORM RAIN SHOWERS WITH GENERAL NON
SEVERE THUNDERSTORMS WELL BEHIND THE FRONT. THE SECOND AREA WILL BE
STRONG TO SEVERE THUNDERSTORMS THAT SHOULD FORM RIGHT ALONG OR VERY
NEAR THE COLD FRONT. INSTABILITY WILL BE RATHER HIGH ALONG THE FRONT
BY LATE AFTERNOON...ALTHOUGH THE WIND SHEAR WILL BE MORE MARGINAL
AND UNIDIRECTIONAL. BULK SHEAR VECTORS ARE ORIENTED RATHER PARALLEL
TO THE SFC COLD FRONT AND THERE SHOULD BE PRETTY GOOD FORCING RIGHT
ALONG THE FRONT. CONSEQUENTLY...THUNDERSTORMS MAY TEND TO BE MORE
LINEAR OR MULTI CELL RATHER THAN DISCRETE SUPERCELLS. THE PRIMARY
THREAT WILL BE LARGE HAIL AND DAMAGING WINDS.
HIGH TEMPERATURES SATURDAY WILL BE A DIFFICULT CALL AND GREATLY
DEPEND ON THE PROGRESSION OF THE COLD FRONT AND CLOUD COVER. WOULD
NOT BE SURPRISED TO SEE A FEW 90S ACROSS SOUTHEAST ZONES...WHILE
NORTHWEST ZONES MAY STALL OUT IN THE UPPER 70S TO AROUND 80 BY EARLY
AFTERNOON. TEMPERATURES MAY EVEN FALL A FEW DEGREES BY EARLY TO MID
AFTERNOON FOR AREAS THAT SEE THE EARLIER FRONTAL PASSAGE.
SUNDAY...GREAT DAY BEHIND THE COLD FRONT WITH DRY WEATHER AND HIGHS
IN THE LOWER TO MID 70S
MONDAY AND TUESDAY...EXPECT DRY WEATHER TO CONTINUE WITH A GRADUAL
MODERATING TREND AS A WEAK UPPER RIDGE MOVES ACROSS AREA. HIGHS
SHOULD CLIMB FROM THE 70S ON MONDAY BACK INTO THE 80S BY TUESDAY.
WEDNESDAY AND THURSDAY...AN UPPER LEVEL TROUGH WILL DEEPEN ACROSS
THE NORTHWESTERN CONUS AND MAY BEGIN TO ENHANCE THE FORCING/LIFT
OVER THE CENTRAL PLAINS. THERE IS STILL A GOOD DEAL OF MODEL
UNCERTAINTY WITH THIS SYSTEM AND HOW IT WILL EVOLVE AND PUSH OUT
INTO THE PLAINS. THERE WILL BE AT LEAST SOME THREAT OF
THUNDERSTORMS ACROSS THE CENTRAL OR NORTHERN PLAINS...BUT DIFFICULT
TO GET INTO SPECIFICS AT THIS TIME GIVEN THE MODEL UNCERTAINTY.
TEMPERATURES ARE MORE LIKELY TO BE ABOVE NORMAL IN THE 80S AHEAD OF
THIS NEXT TROUGH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR NEZ060-061-072>074-
082>084.
KS...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR KSZ005-006-017-018.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
315 PM EDT WED MAY 16 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS THIS
EVENING AND AGAIN ON THURSDAY. THE FRONT WILL MOVE OFF THE COAST
LATE THURSDAY AND STALL. HIGH PRESSURE WILL RIDGE INTO THE AREA
FROM THE NORTHEAST INTO EARLY NEXT WEEK WHILE LOW PRESSURE DEVELOPS
ALONG THE FRONT AND MOVES SLOWLY NE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 PM WEDNESDAY...VIGOROUS SEA BREEZE CONVECTION OVER THE
COASTAL COUNTIES NOW IN PROGRESS IS BEING CAPTURED NEARLY
PERFECTLY BY THE LOCAL HRRR MODEL. THIS SAME MODEL CONTINUES SEA
BREEZE RELATED CONVECTION INTO THE AFTERNOON HOURS...WITH ACTIVITY
SPREADING INLAND DURING THAT TIME. ACT TWO WILL BEGIN THIS EVENING
AS CONVECTION ASSOCIATED WITH A SLOW MOVING COLD FRONT SPREADS
FROM THE NORTHWEST TOWARDS THE COAST.
MODIFIED AREA SOUNDINGS FROM THIS MORNING SHOW A MOIST AND
MODERATELY UNSTABLE ATMOSPHERE WITH STEEP LAPSE RATES DEVELOPING
THIS AFTERNOON. EXTENSIVE CLOUD COVER IS KEEPING A BIT OF A DAMPER
ON CONVECTION INLAND SO FAR...ALTHOUGH CONVECTIVE TEMPERATURES
SEEM TO HAVE BEEN EXCEEDED MOST PLACES. CONVECTION ALONG THE SEA
BREEZE FRONT HAS BEEN STRONG TO MARGINALLY SEVERE SO FAR WITH
REPORTS OF FREQUENT LIGHTNING...HEAVY RAIN AND MOSTLY SMALL HAIL.
AS STATED ABOVE...APPROACHING COLD FRONT WILL TRIGGER ADDITIONAL
CONVECTION STARTING THIS EVENING FROM THE NORTHWEST. FRONT WILL
SLOWLY DROP SE ACROSS THE FORECAST AREA AND OFFSHORE BY AROUND
DAYBREAK THURSDAY. SYSTEM HAS DECENT UPPER LEVEL SUPPORT WITH AN
IMPRESSIVE VORTICITY MAXIMUM AND A MODERATELY DEEP H/5 TROUGH
ACCOMPANYING THE FRONT. THESE FEATURES WILL CONTINUE THE GOOD
CHANCE THAT CONVECTION WILL CONTINUE THROUGH THE OVERNIGHT HOURS.
BASED ON RECENT MODEL PERFORMANCE HAVE GONE ABOVE GUIDANCE FOR
OVERNIGHT TEMPERATURES. MAJOR GUIDANCE HAS BEEN CONSISTENTLY TOO
COOL LATELY...SO WILL BE GOING WITH MID 60S FOR MINIMUMS OVERNIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...THURSDAY LOOKS LIKE ANOTHER DAY WHERE
SCATTERED SHOWERS AND STORMS ARE POSSIBLE AS THE FRONT MOVES SLOWLY
THROUGH BEFORE STALLING OFF THE COAST. THERE IS THE POSSIBILITY OF
SHOWERS AND STORMS AGAIN FRIDAY ALONG THE COAST...OTHERWISE FRIDAY
IS EXPECTED TO BE DRY.
TEMPS WILL REMAIN AROUND CLIMO FOR HIGHS THROUGH THE
PERIOD...REACHING A FEW DEGREES EITHER SIDE OF 80. LOWS AROUND 60
ARE EXPECTED THURSDAY NIGHT WITH MID 50S TO AROUND 60 EXPECTED
FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...SATURDAY LOOKS TO BE DRY WITH HIGH PRESSURE
RIDGING IN FROM THE NORTHEAST. HOWEVER...AN AREA OF LOW PRESSURE
ALONG AN OLD FRONT OFF THE COAST OFF THE COAST WILL BRING A RETURN
OF THE POSSIBILITY OF SHOWERS ON SUNDAY. AS WINDS BECOME MORE
EASTERLY EARLY NEXT WEEK...THE POSSIBILITY OF SHOWERS AND
THUNDERSTORMS...MAINLY OF THE AFTERNOON AND EVENING VARIETY...WILL
RETURN. MAX TEMPERATURES WILL MODERATE SLIGHTLY THROUGH THE PERIOD
FROM UPPER 70S TO LOWER 80S SATURDAY TO LOW TO MID 80S BY MID WEEK.
LOWS WILL ALSO MODERATE FROM THE MID 50S TO AROUND 60 SATURDAY NIGHT
TO LOW TO MID 60S BY TUESDAY NIGHT.
&&
.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
AS OF 17Z...CONVECTION ALREADY FIRING ALONG THE RESULTANT...WITH
CAPES AT 2K+ AND 1.6" PRECIPITABLE WATER. CONVECTION MAY OVERPOWER
THE RESULTANT AND AFFECT THE COASTAL TERMINALS THROUGH MUCH OF THE
AFTERNOON...POSSIBLY EARLY EVENING. LOOK FOR MVFR CEILINGS AND BRIEF
IFR VISIBILITIES IN THE HEAVY RAIN. SCATTERED CONVECTION WILL ALSO
AFFECT INLAND TERMINALS...BUT CONFIDENCE IS LOWER WITH RESPECT TO
TIMING AND INTENSITY. TONIGHT...CONVECTION WILL WANE...BUT MORE
NOCTURNAL SHOWERS COULD ERUPT OFFSHORE...POSSIBLY COMING NEAR THE
MYRTLES AND ILM THROUGH THE OVERNIGHT HOURS. BRIEF IFR CEILINGS ARE
POSSIBLE AFTER 08Z WITH ABUNDANT LOW LEVEL MOISTURE.
THURSDAY...WINDS SHIFT WEAKLY TO THE NORTHEAST WITH MORE SCATTERED
CONVECTION EXPECTED...BEST CHANCE SOUTH.
EXTENDED OUTLOOK...CONDITIONS IMPROVING LATE THURSDAY NIGHT WITH VFR
EXPECTED FRIDAY THROUGH SUNDAY. CHANCE OF SHOWERS SOUTH ON MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 PM WEDNESDAY...WINDS NEAR SHORE THIS AFTERNOON BEING
ENHANCED BY CONVECTION JUST INLAND THAT IS RELATED TO THIS
AFTERNOONS SEA BREEZE CIRCULATION. SOUTHERLY WINDS ARE RIGHT
AROUND 15 KTS NEAR SHORE...AND AROUND 20 IN THE VICINITY OF
CONVECTION. OTHERWISE...GENERALLY LIGHT SOUTH TO SOUTHWESTERLY
WINDS OVER THE WATERS WILL PRECEDE A COLD FRONT TODAY AND THIS
EVENING...WITH WINDS TURNING NEARLY CALM BY DAYBREAK AS THE FRONT
MOVES OVER THE WATERS. SEAS WILL REMAIN IN THEIR PRESENT 3 FT
RANGE THROUGH THE PERIOD...PERHAPS DROPPING A FOOT BY MORNING AS
WINDS SLACKEN.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...THURSDAY IS A TRANSITION DAY AS A COLD
FRONT CROSSES THE WATERS DURING IN THE DAY. NW WINDS OF 5-10 KTS
EARLY THURSDAY WILL BECOME NE AND BEGIN TO INCREASE ON A NE SURGE AS
HIGH PRESSURE RIDGES DOWN THE COAST. WINDS INCREASE TO 10-15 KTS
THURSDAY NIGHT WHICH HELPS BUILD SEAS FROM 2-3 FT UP TO 3-4
FT...WITH THE NE WIND CHOP BECOMING INCREASINGLY MORE DOMINANT IN
THE SPECTRUM. NE WINDS INCREASE FURTHER FRIDAY...TO 15-20 KTS
THROUGH THE DAY. THIS BUILDS SEAS FURTHER...TO 4-5 FT...AND SCEC
HEADLINES MAY BE NEEDED LATE IN THE DAY.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...CONTINUED STRONG E-NE WINDS THROUGH THE
WKND MAY NECESSITATE A SMALL CRAFT ADVISORY THROUGH THROUGH MUCH OF
THE WEEKEND. NE WINDS OF 15-20 KTS WILL PERSIST INTO SUNDAY BEFORE
DIMINISHING LATE SUNDAY INTO MONDAY AS WINDS BECOME MORE EASTERLY.
AS A RESULT...SEAS WILL BUILD TO 4-6 FT BEGINNING VERY EARLY
SATURDAY AND PERSISTING INTO SUNDAY. SEAS WILL SUBSIDE TO AROUND 4
FT BY MONDAY AFTERNOON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...REK/JDW
NEAR TERM...REK
SHORT TERM...RAN
LONG TERM...RAN
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
148 PM EDT WED MAY 16 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS
AGAIN TODAY AND THIS EVENING...WITH SOME OF THESE PRODUCING VERY
HEAVY RAINFALL. SHOWERS AND THUNDERSTORMS ARE POSSIBLE AGAIN
ON THURSDAY AS A COLD FRONT LINGERS NEAR SHORE. BUILDING HIGH
PRESSURE WILL BRING DRIER AND MORE SEASONABLE WEATHER FROM FRIDAY
THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 PM WEDNESDAY...VIGOROUS SEA BREEZE CONVECTION OVER THE
COASTAL COUNTIES NOW IN PROGRESS IS BEING CAPTURED NEARLY
PERFECTLY BY THE LOCAL HRRR MODEL. THIS SAME MODEL CONTINUES SEA
BREEZE RELATED CONVECTION INTO THE AFTERNOON HOURS...WITH ACTIVITY
SPREADING INLAND DURING THAT TIME. ACT TWO WILL BEGIN THIS EVENING
AS CONVECTION ASSOCIATED WITH A SLOW MOVING COLD FRONT SPREADS
FROM THE NORTHWEST TOWARDS THE COAST.
MODIFIED AREA SOUNDINGS FROM THIS MORNING SHOW A MOIST AND
MODERATELY UNSTABLE ATMOSPHERE WITH STEEP LAPSE RATES DEVELOPING
THIS AFTERNOON. EXTENSIVE CLOUD COVER IS KEEPING A BIT OF A DAMPER
ON CONVECTION INLAND SO FAR...ALTHOUGH CONVECTIVE TEMPERATURES
SEEM TO HAVE BEEN EXCEEDED MOST PLACES. CONVECTION ALONG THE SEA
BREEZE FRONT HAS BEEN STRONG TO MARGINALLY SEVERE SO FAR WITH
REPORTS OF FREQUENT LIGHTNING...HEAVY RAIN AND MOSTLY SMALL HAIL.
AS STATED ABOVE...APPROACHING COLD FRONT WILL TRIGGER ADDITIONAL
CONVECTION STARTING THIS EVENING FROM THE NORTHWEST. FRONT WILL
SLOWLY DROP SE ACROSS THE FORECAST AREA AND OFFSHORE BY AROUND
DAYBREAK THURSDAY. SYSTEM HAS DECENT UPPER LEVEL SUPPORT WITH AN
IMPRESSIVE VORTICITY MAXIMUM AND A MODERATELY DEEP H/5 TROUGH
ACCOMPANYING THE FRONT. THESE FEATURES WILL CONTINUE THE GOOD
CHANCE THAT CONVECTION WILL CONTINUE THROUGH THE OVERNIGHT HOURS.
BASED ON RECENT MODEL PERFORMANCE HAVE GONE ABOVE GUIDANCE FOR
OVERNIGHT TEMPERATURES. MAJOR GUIDANCE HAS BEEN CONSISTENTLY TOO
COOL LATELY...SO WILL BE GOING WITH MID 60S FOR MINIMUMS OVERNIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...SLIGHTLY SLOWER EVOLUTION AS DEPICTED IN
GUIDANCE NOW SUGGESTS THAT THURSDAY WILL BE THE TRANSITION DAY AS
COLD FRONT...FINALLY...PUSHES OFFSHORE. PERSISTENT UPPER TROUGH
NEVER QUITE MOVES AWAY HOWEVER...AND INSTEAD ADOPTS AN ORIENTATION
MORE WSW-TO-ENE ACROSS THE SOUTHEAST AND BACK TOWARDS THE MS VLY. AT
THE SAME TIME...AN ARC OF RIDGING DEVELOPS NORTH OF THIS FEATURE
FROM THE OH VLY INTO THE MID-ATLANTIC. WITH WEAK OVERALL FORCING AND
A MORE ZONALLY DRIVEN SETUP AT 500MB...FEATURES WILL CONTINUE TO BE
QUITE SLOW TO MOVE...KEEPING AT LEAST THE POTENTIAL FOR UNSETTLED
WEATHER THROUGH THE PERIOD.
AT THE SURFACE...A COLD FRONT WILL DROP SOUTH THROUGH THE CWA EARLY
THURSDAY...BUT IS NOW PROGGED TO HANG UP AND STALL ACROSS SOUTHERN
AND COASTAL PORTIONS OF THE CWA. THIS WILL AGAIN SERVE AS A FOCUS
FOR CONVECTION...ALTHOUGH POSSIBLY SPARING INLAND LOCATIONS THAT
HAVE SEEN SIGNIFICANT RAINFALL THE PAST FEW DAYS. WILL CARRY CHC POP
THURSDAY ALONG THE COAST AND SC ZONES...WITH SCHC INLAND/NC
COUNTIES. THIS FRONT WILL PUSH ONLY SLIGHTLY FURTHER SOUTH FRIDAY AS
SURFACE HIGH RIDGES DOWN FROM THE NORTH. EVEN THOUGH THE FRONT WILL
REMAIN INVOF THIS AREA...MUCH DRIER AIR NOTED IN FORECAST SOUNDINGS
SUGGESTS THAT FRIDAY WILL BE A DRY DAY SO WILL KEEP POP SILENT
FRIDAY.
TEMPS WILL REMAIN AROUND CLIMO FOR HIGHS AND LOWS THROUGH THE
PERIOD...A FEW DEGREES EITHER SIDE OF 80 AND 60.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 AM WEDNESDAY...GUIDANCE COMING INTO BETTER AGREEMENT FOR
THE WKND WITH A RESIDUAL E-W ORIENTED 500MB TROUGH PERSISTING ACROSS
THE SOUTHEAST...WHILE A RIDGE DEVELOPS NORTH OF THIS FROM THE OH VLY
INTO THE MID ATLANTIC. AT THE SURFACE...A STALLED STATIONARY FRONT
WILL BE DRAPED JUST OFF THE COAST AND BACK INTO NORTHERN
FLORIDA...WHILE A RIDGE OF HIGH PRESSURE PUSHES NE DOWN THE COAST.
EVEN WITH THE FRONT REMAINING NEAR THE AREA...EXPECT THE WKND TO BE
DRY. THE RIDGE OF HIGH PRESSURE WILL PROMOTE A SUBTLE SUBSIDENCE
INVERSION NEAR THE SURFACE WHILE DRIER AIR REMAINS IN THE MID
LEVELS. WILL KEEP POP JUST BELOW THRESHOLD NEAR THE COAST TO ACCOUNT
FOR THE BOUNDARY OFFSHORE...BUT EXPECT NO SHOWERS THROUGH THE WKND.
AS SURFACE HIGH DRIFTS OFF THE NEW ENGLAND COAST MON/TUE...SURFACE
FLOW BECOMES MORE EASTERLY WHICH INCREASES MOISTURE ADVECTION INTO
THE COLUMN. ADDITIONALLY...THICKNESSES BEGIN TO RETURN TO MORE
SEASONABLE LEVELS AS PERSISTENT TROUGHING FINALLY BEGINS TO ERODE.
THIS COULD ALLOW FOR DIURNAL SHOWERS TO RETURN MON/TUE AND WILL
CARRY SCHC BEING SO FAR OUT.
TEMPS THROUGH THE PERIOD WILL BE AROUND CLIMO FOR MAXES AND
MINS...BECOMING SLIGHTLY ABOVE AT THE END OF THE PERIOD.
&&
.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
AS OF 17Z...CONVECTION ALREADY FIRING ALONG THE RESULTANT...WITH
CAPES AT 2K+ AND 1.6" PRECIPITABLE WATER. CONVECTION MAY OVERPOWER
THE RESULTANT AND AFFECT THE COASTAL TERMINALS THROUGH MUCH OF THE
AFTERNOON...POSSIBLY EARLY EVENING. LOOK FOR MVFR CEILINGS AND BRIEF
IFR VISIBILITIES IN THE HEAVY RAIN. SCATTERED CONVECTION WILL ALSO
AFFECT INLAND TERMINALS...BUT CONFIDENCE IS LOWER WITH RESPECT TO
TIMING AND INTENSITY. TONIGHT...CONVECTION WILL WANE...BUT MORE
NOCTURNAL SHOWERS COULD ERUPT OFFSHORE...POSSIBLY COMING NEAR THE
MYRTLES AND ILM THROUGH THE OVERNIGHT HOURS. BRIEF IFR CEILINGS ARE
POSSIBLE AFTER 08Z WITH ABUNDANT LOW LEVEL MOISTURE.
THURSDAY...WINDS SHIFT WEAKLY TO THE NORTHEAST WITH MORE SCATTERED
CONVECTION EXPECTED...BEST CHANCE SOUTH.
EXTENDED OUTLOOK...CONDITIONS IMPROVING LATE THURSDAY NIGHT WITH VFR
EXPECTED FRIDAY THROUGH SUNDAY. CHANCE OF SHOWERS SOUTH ON MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 PM WEDNESDAY...WINDS NEAR SHORE THIS AFTERNOON BEING
ENHANCED BY CONVECTION JUST INLAND THAT IS RELATED TO THIS
AFTERNOONS SEA BREEZE CIRCULATION. SOUTHERLY WINDS ARE RIGHT
AROUND 15 KTS NEAR SHORE...AND AROUND 20 IN THE VICINITY OF
CONVECTION. OTHERWISE...GENERALLY LIGHT SOUTH TO SOUTHWESTERLY
WINDS OVER THE WATERS WILL PRECEDE A COLD FRONT TODAY AND THIS
EVENING...WITH WINDS TURNING NEARLY CALM BY DAYBREAK AS THE FRONT
MOVES OVER THE WATERS. SEAS WILL REMAIN IN THEIR PRESENT 3 FT
RANGE THROUGH THE PERIOD...PERHAPS DROPPING A FOOT BY MORNING AS
WINDS SLACKEN.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...THURSDAY IS A TRANSITION DAY AS A COLD
FRONT CROSSES THE WATERS EARLY IN THE DAY. NW WINDS OF 5-10 KTS
EARLY THURSDAY WILL BECOME NE LATE IN THE DAY AND BEGIN TO INCREASE
ON A NE SURGE AS HIGH PRESSURE RIDGES DOWN THE COAST. WINDS INCREASE
TO 10-15 KTS THURSDAY NIGHT WHICH HELPS BUILD SEAS FROM 2-3 FT UP TO
3-4 FT...WITH THE NE WIND CHOP BECOMING INCREASINGLY MORE DOMINANT
IN THE SPECTRUM. NE WINDS INCREASE FURTHER FRIDAY...TO 15-20 KTS
THROUGH THE DAY. THIS BUILDS SEAS FURTHER...TO 4-5 FT...AND SCEC
HEADLINES MAY BE NEEDED LATE IN THE DAY.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...CONTINUED STRONG NE WINDS THROUGH THE WKND
WILL LIKELY NECESSITATE A SMALL CRAFT ADVISORY THROUGH THE ENTIRE
EXTENDED. NE WINDS OF 15-20 KTS WILL PERSIST THROUGH THE WKND WITH
ONLY MINOR DIURNAL VARIATIONS. THIS BUILDS SEAS TO 4-6 FT BEGINNING
VERY EARLY SATURDAY AND PERSISTING THROUGH SUNDAY NIGHT...WITH A
6SEC NE WIND WAVE BEING THE DOMINANT FEATURE IN THE SEA SPECTRUM. AS
IS FREQUENTLY THE CASE WITH NE SURGES...THE HIGHEST SEAS WILL BE
BLOCKED BY THE FRYING PAN SHOALS...SO A SHADOW REGION OF 2-4 FT SEAS
IN THE INNER 10NM ALONG BRUNSWICK AND NORTHERN HORRY COUNTIES WILL
EXIST THROUGH THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...REK/JDW
NEAR TERM...REK
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...DL
MARINE...REK/JDW
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
119 PM EDT WED MAY 16 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND MOVE
THROUGH THE REGION LATE TONIGHT. HIGH PRESSURE WILL BUILD IN FROM
THE NORTH BEHIND THE FRONT AND CONTINUE TO RIDGE INTO THE AREA
THIS WEEKEND AS AN AREA OF LOW PRESSURE LIFTS NORTH OFFSHORE.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 110 PM WED...MADE MINOR ADJUSTMENTS TO REFLECT CURRENT
TRENDS. THIS POSITIVELY TILTED UPPER LEVEL TROUGH WILL PERSIST ACROSS
THE APPALACHIANS INTO THE DEEP SOUTH WHILE A DISSIPATING TROUGH OF
LOW PRES CONTINUES ACROSS THE CAROLINA PIEDMONT REGION. ATMOSPHERE
CONDITIONS CONTINUE TO BE VERY MOIST AND UNSTABLE WITH CURRENT
CAPE VALUES IN 2500 ACROSS THE SOUTHERN COASTAL PLAINS AND LI OF
-7. BOTH SPC MESO ANALYSIS AND RUC MODEL REFLECTS PERFECTLY WHAT
IS HAPPENING ON RADAR. RADAR IS CURRENTLY SHOWING SHOWERS AND
THUNDERSTORMS ALONG OR EAST OF HWY 17 AND WILL CONTINUE INTO THE
EVENING. HIGHS TODAY GENERALLY IN THE L80S INLAND AND U70S ALONG
THE COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
AS OF 315 AM WED...A ROBUST NRN STREAM SHORTWAVE TROUGH SLIDES E
OF THE GREAT LAKES TODAY AND MOVES INTO NEW ENGLAND TONIGHT WHILE
THE ATTENDANT COLD FRONT DROPS ACROSS THE OHIO RIVER VALLEY TODAY
AND IS EXPECTED TO PUSH THROUGH ERN NC LATE TONIGHT. ONGOING
SHOWERS AND TSTMS EARLY THIS EVENING SHOULD DISSIPATE WITH LOSS OF
SFC HEATING BUT THE AIRMASS REMAINS CONDITIONALLY UNSTABLE AND
FRONTAL FORCING COULD BRING ADDITIONAL SHOWERS OR STORMS ACROSS
THE REGION OVERNIGHT. SWLY FLOW AHEAD OF THE FRONT WILL BRING
ANOTHER MILD NIGHT WITH LOWS MAINLY IN THE M/U60S.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 315 AM WEDNESDAY...ENOUGH MODEL AGREEMENT TO MAKE MINOR
ADJUSTMENTS TO THU-FRI PERIOD...THEN MODELS DIVERGE ON PATTERN
EVOLUTION...LEADING TO LOW CONFIDENCE FCST FOR SAT-TUE.
SFC FRONT WILL BE MOVING OFF COAST EARLY THU...BUT CAA AND LINGERING
UPR TROF ENERGY SUPPORT PSBL SHOWER/TSTM DEVELOPMENT WITH ALL MODELS
INDICATING SOME LIGHT QPF. ADJUSTED FCST FOR 20N/40S POPS DURING THE
DAY...WITH LINGERING 20/30 SRN COASTAL SECTIONS THU NIGHT...IN LINE
WITH MOS POP BLEND. MODELS GENERALLY AGREE ON DRY FCST FOR FRI AND
FRI NIGHT WITH DRYING ATMOS AND UPR TROF AXIS MOVING OFF COAST.
00Z GFS HAS MAINLY DRY FCST FOR WEEKEND WITH SE UPR LOW SUPPRESSED
FARTHER S...WHILE 00Z ECMWF CONTINUES TO INDICATE UPR LOW AXIS
STRETCHED SW TO NE...WITH OFFSHORE SFC LOW DEVELOPMENT GRADUALLY
RETROGRADING BACK TOWARD COAST SUN. NOT ENOUGH CONFIDENCE TO MAKE
ADJUSTMENTS TO PREVIOUS FCST...AND CONTINUED WITH LOW CHC POPS
RETURNING FOR SUN-TUE.
COOLER HIGH PRES WILL RESULT IN TEMPS MAINLY 50S/70S FOR
THU-FRI...WITH SOME GRADUAL MODERATION REST OF PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1020 AM WED...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
EXPECTED AGAIN TODAY WITH A MOIST AND UNSTABLE AIRMASS IN PLACE
AND A WEAK UPPER LEVEL DISTURBANCE MOVING ACROSS THE AREA. SHOWERS
TAPER OFF THIS EVENING BUT CANNOT RULE OUT ISOLATED TO SCATTERED
SHOWERS PERSISTING OVERNIGHT WITH DESCENT INSTABILITY ALOFT AND A
COLD FRONT DROPPING INTO THE AREA LATE. ALSO CANNOT RULE OUT
PATCHY FOG LATE TONIGHT WITH ABUNDANT LOW LEVEL
MOISTURE...ESPECIALLY IN AREAS THAT RECEIVE SIGNIFICANT RAINFALL
TODAY.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM WEDNESDAY...COLD FRONT WILL BE MOVING OFF COAST EARLY
THU BUT DEVELOPING NE FLOW LIKELY TO CONTINUE MVFR CONDITIONS WITH
SCT SHOWERS/TSTMS DURING DAY THU AND WITH SOME STRATUS/SCU THU
NIGHT. VFR EXPECTED TO RETURN ON FRI WITH HIGH PRES BUILDING IN FROM
N...AND CONTINUE THROUGH SAT. CHC OF SHOWERS/TSTMS MAY DEVELOP
AGAIN SUN WITH INCREASING ONSHORE FLOW.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 110 PM WED...CURRENT FORECAST IS IN GREAT SHAPE. NO CHANGES
NEEDED FOR THIS AFTERNOON.
PREV DISC...S/SWLY WINDS AOB 15 KT CONTINUE TODAY WITH HIGH PRES
CENTERED OFFSHORE AND A DISSIPATING TROUGH INLAND AND A COLD FRONT
APPROACHING FROM THE NW. SEAS GRADUALLY DISSIPATING EARLY THIS
MORNING AND BUOY 44095 OFF OREGON INLET HAS DROPPED BELOW 6 FT
OVER THE PAST COUPLE HOURS AND EXPECT THE TREND TO CONTINUE AND
WILL DROP THE SCA. SEAS AROUND 2-5 FT EXPECTED TODAY AND TONIGHT.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM WEDNESDAY...MODELS CONTINUE TO SUPPORT CAA SURGE OF NE
WINDS 15-20 KT SPREADING N TO S ALONG COAST ON THU AS HIGH PRES
BUILDS ACROSS TO N. NE WINDS EXPECTED TO PERSIST THROUGH WEEKEND BUT
LOW CONFIDENCE ON SPEEDS BEYOND FRIDAY DUE TO MODEL DIFFERENCES ON
STRENGTH OF PRES GRADIENT. ALL MODELS GENERALLY AGREE TO HIGH PRES
WILL CONTINUE TO EXTEND OVER AREA FROM MID ATLC COAST...BUT NAM AND
ECMWF HAVE LOW PRES DEVELOPING OFFSHORE AND MOVING TOWARD COAST
DURING PERIOD RESULTING IN MUCH STRONGER WINDS. HAVE LEANED TO GFS
AND PREVIOUS FCST FOR WEEKEND...WITH PERSISTENT NE 15-20 KT FLOW
LIKELY TO PRODUCE 5-6 FT SEAS FRIDAY-SUNDAY. STRONGER ECMWF AND NAM
SOLUTIONS WOULD OBVIOUSLY RESULT IN PERIOD OF HIGHER WINDS AND
SEAS...ESPECIALLY FOR NORTHERN AND CENTRAL WATERS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK/BM
SHORT TERM...SK
LONG TERM...JBM
AVIATION...JBM/HSA/SK
MARINE...JBM/SK/BM
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1225 PM EDT WED MAY 16 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS AGAIN
TODAY...WITH SOME OF THESE PRODUCING VERY HEAVY RAINFALL. SHOWERS
AND THUNDERSTORMS ARE POSSIBLE AGAIN THURSDAY AS AN APPROACHING COLD
FRONT FINALLY PUSHES OFFSHORE. BUILDING HIGH PRESSURE WILL BRING
DRIER AND MORE SEASONABLE WEATHER FRIDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10:30 AM WEDNESDAY...ANALYSIS OF MORNING SOUNDINGS CONFIRM
EARLIER HYPOTHESIS THAT TODAY WILL FEATURE ANOTHER ROUND OF
DIURNALLY-DRIVEN CONVECTION. MOIST SOUTHWESTERLY FLOW WILL REMAIN
IN PLACE WITH P/W VALUES OF AROUND 1.50 INCHES AND DEWPOINTS WELL
IN THE 60S. MODEL SOUNDINGS DEVELOP MODERATE INSTABILITY WITH
STEEP LAPSE RATES ACROSS THE AREA THIS AFTERNOON. PEAK
DESTABILIZATION WILL THUS BE THIS AFTERNOON...WHEN THE GREATEST
THREAT OF STRONG CONVECTION WILL BE. UNTIL THEN...EXPECT INITIAL
CONVECTION TO FIRE UP ALONG A WEAK SEA BREEZE BOUNDARY LATE THIS
MORNING AND EARLY AFTERNOON. HRRR MODEL DID FAIRLY WELL DEPICTING
THIS YESTERDAY...AND IS GOING FOR A REPEAT PERFORMANCE TODAY.
PREVIOUS DISCUSSION FOLLOWS:
INGREDIENTS COALESCING FOR ANOTHER ROUND OF DIURNAL THUNDERSTORMS
AS HEATING DESTABILIZES A MOISTURE RICH COLUMN. WEAK OUTFLOW
BOUNDARIES SNAKING ACROSS THE REGION EARLY THIS MORNING WILL
PRODUCE ISOLATED HEAVY THUNDERSHOWERS EVEN PRIOR TO DIURNAL
WARMING. THE SEA BREEZE BOUNDARY WILL PROVIDE A FOCUS FOR A BROKEN
LINE OF THUNDERSTORMS TO LIGHT UP BY EARLY AFTERNOON ACROSS OUR
COASTAL INTERIOR. UPPER WINDS MAY PUSH THE CONVECTION BACK TOWARD
THE COAST IN THE LATE AFTERNOON AND EVENING.
PRECIPITABLE WATER VALUES BETWEEN 1.3-1.5 ACROSS THE REGION AND
DEWPOINTS OF 66-71...WILL INTERACT WITH SHARPENING LOW-LEVEL LAPSE
RATES BY MID AFTERNOON TO PRODUCE AN ISOLATED POTENTIAL FOR STRONG
WIND GUSTS OR DAMAGING WINDS.
PLENTIFUL CLOUDS WILL KEEP MAX TEMPS HELD IN THE LOWER TO MIDDLE
80S TODAY. A COLD FRONT WILL EXIT THE MOUNTAINS TODAY AND MOVE TO
THE COAST LATE TONIGHT INTO DAYBREAK THURSDAY. FOR THIS REASON
MENTIONABLE POP VALUES WERE RETAINED TROUGH THE OVERNIGHT PERIOD.
MINIMUM TEMPS AS A RESULT SHOULD BE JUST A DEGREE OR TWO COOLER
THAN THE LAST FEW MORNINGS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...SLIGHTLY SLOWER EVOLUTION AS DEPICTED IN
GUIDANCE NOW SUGGESTS THAT THURSDAY WILL BE THE TRANSITION DAY AS
COLD FRONT...FINALLY...PUSHES OFFSHORE. PERSISTENT UPPER TROUGH
NEVER QUITE MOVES AWAY HOWEVER...AND INSTEAD ADOPTS AN ORIENTATION
MORE WSW-TO-ENE ACROSS THE SOUTHEAST AND BACK TOWARDS THE MS VLY. AT
THE SAME TIME...AN ARC OF RIDGING DEVELOPS NORTH OF THIS FEATURE
FROM THE OH VLY INTO THE MID-ATLANTIC. WITH WEAK OVERALL FORCING AND
A MORE ZONALLY DRIVEN SETUP AT 500MB...FEATURES WILL CONTINUE TO BE
QUITE SLOW TO MOVE...KEEPING AT LEAST THE POTENTIAL FOR UNSETTLED
WEATHER THROUGH THE PERIOD.
AT THE SURFACE...A COLD FRONT WILL DROP SOUTH THROUGH THE CWA EARLY
THURSDAY...BUT IS NOW PROGGED TO HANG UP AND STALL ACROSS SOUTHERN
AND COASTAL PORTIONS OF THE CWA. THIS WILL AGAIN SERVE AS A FOCUS
FOR CONVECTION...ALTHOUGH POSSIBLY SPARING INLAND LOCATIONS THAT
HAVE SEEN SIGNIFICANT RAINFALL THE PAST FEW DAYS. WILL CARRY CHC POP
THURSDAY ALONG THE COAST AND SC ZONES...WITH SCHC INLAND/NC
COUNTIES. THIS FRONT WILL PUSH ONLY SLIGHTLY FURTHER SOUTH FRIDAY AS
SURFACE HIGH RIDGES DOWN FROM THE NORTH. EVEN THOUGH THE FRONT WILL
REMAIN INVOF THIS AREA...MUCH DRIER AIR NOTED IN FORECAST SOUNDINGS
SUGGESTS THAT FRIDAY WILL BE A DRY DAY SO WILL KEEP POP SILENT
FRIDAY.
TEMPS WILL REMAIN AROUND CLIMO FOR HIGHS AND LOWS THROUGH THE
PERIOD...A FEW DEGREES EITHER SIDE OF 80 AND 60.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...GUIDANCE COMING INTO BETTER AGREEMENT FOR
THE WKND WITH A RESIDUAL E-W ORIENTED 500MB TROUGH PERSISTING ACROSS
THE SOUTHEAST...WHILE A RIDGE DEVELOPS NORTH OF THIS FROM THE OH VLY
INTO THE MID ATLANTIC. AT THE SURFACE...A STALLED STATIONARY FRONT
WILL BE DRAPED JUST OFF THE COAST AND BACK INTO NORTHERN
FLORIDA...WHILE A RIDGE OF HIGH PRESSURE PUSHES NE DOWN THE COAST.
EVEN WITH THE FRONT REMAINING NEAR THE AREA...EXPECT THE WKND TO BE
DRY. THE RIDGE OF HIGH PRESSURE WILL PROMOTE A SUBTLE SUBSIDENCE
INVERSION NEAR THE SURFACE WHILE DRIER AIR REMAINS IN THE MID
LEVELS. WILL KEEP POP JUST BELOW THRESHOLD NEAR THE COAST TO ACCOUNT
FOR THE BOUNDARY OFFSHORE...BUT EXPECT NO SHOWERS THROUGH THE WKND.
AS SURFACE HIGH DRIFTS OFF THE NEW ENGLAND COAST MON/TUE...SURFACE
FLOW BECOMES MORE EASTERLY WHICH INCREASES MOISTURE ADVECTION INTO
THE COLUMN. ADDITIONALLY...THICKNESSES BEGIN TO RETURN TO MORE
SEASONABLE LEVELS AS PERSISTENT TROUGHING FINALLY BEGINS TO ERODE.
THIS COULD ALLOW FOR DIURNAL SHOWERS TO RETURN MON/TUE AND WILL
CARRY SCHC BEING SO FAR OUT.
TEMPS THROUGH THE PERIOD WILL BE AROUND CLIMO FOR MAXES AND
MINS...BECOMING SLIGHTLY ABOVE AT THE END OF THE PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 17Z...CONVECTION ALREADY FIRING ALONG THE RESULTANT...WITH
CAPES AT 2K+ AND 1.6" PRECIPITABLE WATER. CONVECTION MAY OVERPOWER
THE RESULTANT AND AFFECT THE COASTAL TERMINALS THROUGH MUCH OF THE
AFTERNOON...POSSIBLY EARLY EVENING. LOOK FOR MVFR CEILINGS AND BRIEF
IFR VISIBILITIES IN THE HEAVY RAIN. SCATTERED CONVECTION WILL ALSO
AFFECT INLAND TERMINALS...BUT CONFIDENCE IS LOWER WITH RESPECT TO
TIMING AND INTENSITY. TONIGHT...CONVECTION WILL WANE...BUT MORE
NOCTURNAL SHOWERS COULD ERUPT OFFSHORE...POSSIBLY COMING NEAR THE
MYRTLES AND ILM THROUGH THE OVERNIGHT HOURS. BRIEF IFR CEILINGS ARE
POSSIBLE AFTER 08Z WITH ABUNDANT LOW LEVEL MOISTURE.
THURSDAY...WINDS SHIFT WEAKLY TO THE NORTHEAST WITH MORE SCATTERED
CONVECTION EXPECTED...BEST CHANCE SOUTH.
EXTENDED OUTLOOK...CONDITIONS IMPROVING LATE THURSDAY NIGHT WITH VFR
EXPECTED FRIDAY THROUGH SUNDAY. CHANCE OF SHOWERS SOUTH ON MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10:30 AM WEDNESDAY...LATEST OBS SHOWS SOUTHERLY WINDS IN THE
10 KT RANGE...WITH SEAS OF AROUND 3 FT. THIS IS RIGHT AS FORECAST
FOR THIS TIME OF DAY. PREVIOUS DISCUSSION STILL APPLIES AND FOLLOWS
BELOW:
SEA HEIGHTS AND SYNOPTIC WINDS WILL NOT POSE A THREAT TODAY...BUT
ISOLATED TO SCATTERED THUNDERSTORMS MAY PRODUCE TREACHEROUS
CONDITIONS LOCALLY...LATER TODAY AND TONIGHT AS A WEAK COLD FRONT
APPROACHES THE COAST. MARINERS SHOULD CONSULT RADAR TRENDS BEFORE
HEADING OUT TO ASCERTAIN THE LOCAL RISKS. ELSE-WISE...SEAS
GENERALLY COMPOSED OF SE WAVES 3-4 FEET IN 7 SECONDS INTERVALS
WITH A LIGHT SSW CHOP. WINDS AND WIND-WAVES IN AND NEAR TSTMS WILL
BE LOCALLY MUCH HIGHER. WINDS TO SHIFT TO NW BUT OVERALL LIGHT
WIND-SPEEDS IN THE PRE-DAWN HOURS OF THU AS A WEAK COLD FRONT
MOVES OFFSHORE BY SUNRISE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...THURSDAY IS A TRANSITION DAY AS A COLD
FRONT CROSSES THE WATERS EARLY IN THE DAY. NW WINDS OF 5-10 KTS
EARLY THURSDAY WILL BECOME NE LATE IN THE DAY AND BEGIN TO INCREASE
ON A NE SURGE AS HIGH PRESSURE RIDGES DOWN THE COAST. WINDS INCREASE
TO 10-15 KTS THURSDAY NIGHT WHICH HELPS BUILD SEAS FROM 2-3 FT UP TO
3-4 FT...WITH THE NE WIND CHOP BECOMING INCREASINGLY MORE DOMINANT
IN THE SPECTRUM. NE WINDS INCREASE FURTHER FRIDAY...TO 15-20 KTS
THROUGH THE DAY. THIS BUILDS SEAS FURTHER...TO 4-5 FT...AND SCEC
HEADLINES MAY BE NEEDED LATE IN THE DAY.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...CONTINUED STRONG NE WINDS THROUGH THE WKND
WILL LIKELY NECESSITATE A SMALL CRAFT ADVISORY THROUGH THE ENTIRE
EXTENDED. NE WINDS OF 15-20 KTS WILL PERSIST THROUGH THE WKND WITH
ONLY MINOR DIURNAL VARIATIONS. THIS BUILDS SEAS TO 4-6 FT BEGINNING
VERY EARLY SATURDAY AND PERSISTING THROUGH SUNDAY NIGHT...WITH A
6SEC NE WIND WAVE BEING THE DOMINANT FEATURE IN THE SEA SPECTRUM. AS
IS FREQUENTLY THE CASE WITH NE SURGES...THE HIGHEST SEAS WILL BE
BLOCKED BY THE FRYING PAN SHOALS...SO A SHADOW REGION OF 2-4 FT SEAS
IN THE INNER 10NM ALONG BRUNSWICK AND NORTHERN HORRY COUNTIES WILL
EXIST THROUGH THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...MJC/REK
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...43
MARINE...MJC/REK/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1035 AM EDT WED MAY 16 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS AGAIN
TODAY...WITH SOME OF THESE PRODUCING VERY HEAVY RAINFALL. SHOWERS
AND THUNDERSTORMS ARE POSSIBLE AGAIN THURSDAY AS AN APPROACHING COLD
FRONT FINALLY PUSHES OFFSHORE. BUILDING HIGH PRESSURE WILL BRING
DRIER AND MORE SEASONABLE WEATHER FRIDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10:30 AM WEDNESDAY...ANALYSIS OF MORNING SOUNDINGS CONFIRM
EARLIER HYPOTHESIS THAT TODAY WILL FEATURE ANOTHER ROUND OF
DIURNALLY-DRIVEN CONVECTION. MOIST SOUTHWESTERLY FLOW WILL REMAIN
IN PLACE WITH P/W VALUES OF AROUND 1.50 INCHES AND DEWPOINTS WELL
IN THE 60S. MODEL SOUNDINGS DEVELOP MODERATE INSTABILITY WITH
STEEP LAPSE RATES ACROSS THE AREA THIS AFTERNOON. PEAK
DESTABILIZATION WILL THUS BE THIS AFTERNOON...WHEN THE GREATEST
THREAT OF STRONG CONVECTION WILL BE. UNTIL THEN...EXPECT INITIAL
CONVECTION TO FIRE UP ALONG A WEAK SEA BREEZE BOUNDARY LATE THIS
MORNING AND EARLY AFTERNOON. HRRR MODEL DID FAIRLY WELL DEPICTING
THIS YESTERDAY...AND IS GOING FOR A REPEAT PERFORMANCE TODAY.
PREVIOUS DISCUSSION FOLLOWS:
INGREDIENTS COALESCING FOR ANOTHER ROUND OF DIURNAL THUNDERSTORMS
AS HEATING DESTABILIZES A MOISTURE RICH COLUMN. WEAK OUTFLOW
BOUNDARIES SNAKING ACROSS THE REGION EARLY THIS MORNING WILL
PRODUCE ISOLATED HEAVY THUNDERSHOWERS EVEN PRIOR TO DIURNAL
WARMING. THE SEA BREEZE BOUNDARY WILL PROVIDE A FOCUS FOR A BROKEN
LINE OF THUNDERSTORMS TO LIGHT UP BY EARLY AFTERNOON ACROSS OUR
COASTAL INTERIOR. UPPER WINDS MAY PUSH THE CONVECTION BACK TOWARD
THE COAST IN THE LATE AFTERNOON AND EVENING.
PRECIPITABLE WATER VALUES BETWEEN 1.3-1.5 ACROSS THE REGION AND
DEWPOINTS OF 66-71...WILL INTERACT WITH SHARPENING LOW-LEVEL LAPSE
RATES BY MID AFTERNOON TO PRODUCE AN ISOLATED POTENTIAL FOR STRONG
WIND GUSTS OR DAMAGING WINDS.
PLENTIFUL CLOUDS WILL KEEP MAX TEMPS HELD IN THE LOWER TO MIDDLE
80S TODAY. A COLD FRONT WILL EXIT THE MOUNTAINS TODAY AND MOVE TO
THE COAST LATE TONIGHT INTO DAYBREAK THURSDAY. FOR THIS REASON
MENTIONABLE POP VALUES WERE RETAINED TROUGH THE OVERNIGHT PERIOD.
MINIMUM TEMPS AS A RESULT SHOULD BE JUST A DEGREE OR TWO COOLER
THAN THE LAST FEW MORNINGS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...SLIGHTLY SLOWER EVOLUTION AS DEPICTED IN
GUIDANCE NOW SUGGESTS THAT THURSDAY WILL BE THE TRANSITION DAY AS
COLD FRONT...FINALLY...PUSHES OFFSHORE. PERSISTENT UPPER TROUGH
NEVER QUITE MOVES AWAY HOWEVER...AND INSTEAD ADOPTS AN ORIENTATION
MORE WSW-TO-ENE ACROSS THE SOUTHEAST AND BACK TOWARDS THE MS VLY. AT
THE SAME TIME...AN ARC OF RIDGING DEVELOPS NORTH OF THIS FEATURE
FROM THE OH VLY INTO THE MID-ATLANTIC. WITH WEAK OVERALL FORCING AND
A MORE ZONALLY DRIVEN SETUP AT 500MB...FEATURES WILL CONTINUE TO BE
QUITE SLOW TO MOVE...KEEPING AT LEAST THE POTENTIAL FOR UNSETTLED
WEATHER THROUGH THE PERIOD.
AT THE SURFACE...A COLD FRONT WILL DROP SOUTH THROUGH THE CWA EARLY
THURSDAY...BUT IS NOW PROGGED TO HANG UP AND STALL ACROSS SOUTHERN
AND COASTAL PORTIONS OF THE CWA. THIS WILL AGAIN SERVE AS A FOCUS
FOR CONVECTION...ALTHOUGH POSSIBLY SPARING INLAND LOCATIONS THAT
HAVE SEEN SIGNIFICANT RAINFALL THE PAST FEW DAYS. WILL CARRY CHC POP
THURSDAY ALONG THE COAST AND SC ZONES...WITH SCHC INLAND/NC
COUNTIES. THIS FRONT WILL PUSH ONLY SLIGHTLY FURTHER SOUTH FRIDAY AS
SURFACE HIGH RIDGES DOWN FROM THE NORTH. EVEN THOUGH THE FRONT WILL
REMAIN INVOF THIS AREA...MUCH DRIER AIR NOTED IN FORECAST SOUNDINGS
SUGGESTS THAT FRIDAY WILL BE A DRY DAY SO WILL KEEP POP SILENT
FRIDAY.
TEMPS WILL REMAIN AROUND CLIMO FOR HIGHS AND LOWS THROUGH THE
PERIOD...A FEW DEGREES EITHER SIDE OF 80 AND 60.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...GUIDANCE COMING INTO BETTER AGREEMENT FOR
THE WKND WITH A RESIDUAL E-W ORIENTED 500MB TROUGH PERSISTING ACROSS
THE SOUTHEAST...WHILE A RIDGE DEVELOPS NORTH OF THIS FROM THE OH VLY
INTO THE MID ATLANTIC. AT THE SURFACE...A STALLED STATIONARY FRONT
WILL BE DRAPED JUST OFF THE COAST AND BACK INTO NORTHERN
FLORIDA...WHILE A RIDGE OF HIGH PRESSURE PUSHES NE DOWN THE COAST.
EVEN WITH THE FRONT REMAINING NEAR THE AREA...EXPECT THE WKND TO BE
DRY. THE RIDGE OF HIGH PRESSURE WILL PROMOTE A SUBTLE SUBSIDENCE
INVERSION NEAR THE SURFACE WHILE DRIER AIR REMAINS IN THE MID
LEVELS. WILL KEEP POP JUST BELOW THRESHOLD NEAR THE COAST TO ACCOUNT
FOR THE BOUNDARY OFFSHORE...BUT EXPECT NO SHOWERS THROUGH THE WKND.
AS SURFACE HIGH DRIFTS OFF THE NEW ENGLAND COAST MON/TUE...SURFACE
FLOW BECOMES MORE EASTERLY WHICH INCREASES MOISTURE ADVECTION INTO
THE COLUMN. ADDITIONALLY...THICKNESSES BEGIN TO RETURN TO MORE
SEASONABLE LEVELS AS PERSISTENT TROUGHING FINALLY BEGINS TO ERODE.
THIS COULD ALLOW FOR DIURNAL SHOWERS TO RETURN MON/TUE AND WILL
CARRY SCHC BEING SO FAR OUT.
TEMPS THROUGH THE PERIOD WILL BE AROUND CLIMO FOR MAXES AND
MINS...BECOMING SLIGHTLY ABOVE AT THE END OF THE PERIOD.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...JUICY AIRMASS IN PLACE WITH CONVECTION JUST OFFSHORE.
LOOK FOR A RATHER UNEVENTFUL MORNING...BUT AS THE SURFACE CAPES
REACH 2K OR MORE...CONVECTION WILL REFIRE ALONG THE SEA BREEZE
RESULTANT. CONVECTION MAY OVERPOWER THE RESULTANT AND AFFECT THE
COASTAL TERMINALS THROUGH MUCH OF THE AFTERNOON...POSSIBLY EARLY
EVENING. LOOK FOR MVFR CEILINGS AND BRIEF IFR VISIBILITIES IN THE
HEAVY RAIN. SCATTERED CONVECTION WILL ALSO AFFECT INLAND
TERMINALS...BUT CONFIDENCE IS LOWER WITH RESPECT TO TIMING AND
INTENSITY. TONIGHT...CONVECTION WILL WANE...BUT MORE NOCTURNAL
SHOWERS COULD ERUPT OFFSHORE...POSSIBLY COMING NEAR THE MYRTLES AND
ILM THROUGH THE OVERNIGHT HOURS.
EXTENDED OUTLOOK...UNSETTLED WEATHER THROUGH THURSDAY WITH A GOOD
CHANCE FOR SHOWERS/ISOLATED THUNDERSTORMS/TEMPO MVFR. VFR FRIDAY
THROUGH SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10:30 AM WEDNESDAY...LATEST OBS SHOWS SOUTHERLY WINDS IN THE
10 KT RANGE...WITH SEAS OF AROUND 3 FT. THIS IS RIGHT AS FORECAST
FOR THIS TIME OF DAY. PREVIOUS DISCUSSION STILL APPLIES AND FOLLOWS
BELOW:
SEA HEIGHTS AND SYNOPTIC WINDS WILL NOT POSE A THREAT TODAY...BUT
ISOLATED TO SCATTERED THUNDERSTORMS MAY PRODUCE TREACHEROUS
CONDITIONS LOCALLY...LATER TODAY AND TONIGHT AS A WEAK COLD FRONT
APPROACHES THE COAST. MARINERS SHOULD CONSULT RADAR TRENDS BEFORE
HEADING OUT TO ASCERTAIN THE LOCAL RISKS. ELSE-WISE...SEAS
GENERALLY COMPOSED OF SE WAVES 3-4 FEET IN 7 SECONDS INTERVALS
WITH A LIGHT SSW CHOP. WINDS AND WIND-WAVES IN AND NEAR TSTMS WILL
BE LOCALLY MUCH HIGHER. WINDS TO SHIFT TO NW BUT OVERALL LIGHT
WIND-SPEEDS IN THE PRE-DAWN HOURS OF THU AS A WEAK COLD FRONT
MOVES OFFSHORE BY SUNRISE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...THURSDAY IS A TRANSITION DAY AS A COLD
FRONT CROSSES THE WATERS EARLY IN THE DAY. NW WINDS OF 5-10 KTS
EARLY THURSDAY WILL BECOME NE LATE IN THE DAY AND BEGIN TO INCREASE
ON A NE SURGE AS HIGH PRESSURE RIDGES DOWN THE COAST. WINDS INCREASE
TO 10-15 KTS THURSDAY NIGHT WHICH HELPS BUILD SEAS FROM 2-3 FT UP TO
3-4 FT...WITH THE NE WIND CHOP BECOMING INCREASINGLY MORE DOMINANT
IN THE SPECTRUM. NE WINDS INCREASE FURTHER FRIDAY...TO 15-20 KTS
THROUGH THE DAY. THIS BUILDS SEAS FURTHER...TO 4-5 FT...AND SCEC
HEADLINES MAY BE NEEDED LATE IN THE DAY.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...CONTINUED STRONG NE WINDS THROUGH THE WKND
WILL LIKELY NECESSITATE A SMALL CRAFT ADVISORY THROUGH THE ENTIRE
EXTENDED. NE WINDS OF 15-20 KTS WILL PERSIST THROUGH THE WKND WITH
ONLY MINOR DIURNAL VARIATIONS. THIS BUILDS SEAS TO 4-6 FT BEGINNING
VERY EARLY SATURDAY AND PERSISTING THROUGH SUNDAY NIGHT...WITH A
6SEC NE WIND WAVE BEING THE DOMINANT FEATURE IN THE SEA SPECTRUM. AS
IS FREQUENTLY THE CASE WITH NE SURGES...THE HIGHEST SEAS WILL BE
BLOCKED BY THE FRYING PAN SHOALS...SO A SHADOW REGION OF 2-4 FT SEAS
IN THE INNER 10NM ALONG BRUNSWICK AND NORTHERN HORRY COUNTIES WILL
EXIST THROUGH THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...MJC/REK
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MJC
MARINE...MJC/REK/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
400 PM EDT WED MAY 16 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTH THROUGH THE AREA THIS EVENING
OFFERING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS EARLY. HIGH
PRESSURE WILL BUILD INTO THE REGION PROVIDING DRY WEATHER THROUGH
THE REMAINDER OF THE WEEK. TEMPERATURES WILL GRADUALLY WARM TO ABOVE
NORMAL BY FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
UPPER LEVEL TROF TO PIVOT EAST THRU THE GREAT LAKES INTO NEW
ENGLAND/SE CANADA BY THURSDAY MORNING. ASSOCIATED COLD FRONT WHICH
EXTENDS FROM WESTERN PA THRU SW OHIO AND SRN INDIANA TO DROP
SOUTH OF THE OHIO RIVER BY LATE AFTERNOON. BOTH NAM/GFS APPEAR
OVERDONE WITH SURFACE DEWPOINTS POOLED IN THE MID 60S ALONG AND
SOUTH OF THE FRONTAL BOUNDARY. 13 KM RAP MODEL SOLN LOOKS MORE
REALISTIC WITH DEWPOINTS IN THE UPPER 50S YIELDING MARGINAL BLYR
CAPES LESS THAN 1000 J/KG ACRS SE OHIO AND NRN KY. WL CONTINUE TO
LIMIT POPS TO SLIGHT CHANCE FOR THUNDERSTORMS ACRS THESE AREAS
EARLY. SINCE CONVECTION IS STARTING TO DEVELOP WILL OPT FOR AREAL
COVERAGE WORDING...ISOLATED THUNDERSTORMS.
IN THE WAKE OF THIS FRONT SFC HIGH PRESSURE BUILDS INTO THE GREAT
LAKES OVERNIGHT. SUBSIDENCE WILL LEAD TO CLEARING SKIES. DRY AIRMASS
AND LOW LEVEL CAA WILL LEAD TO BELOW NORMAL TEMPERATURES. HAVE FCST
LOWS RANGING FROM NEAR 40 NE TO LOWER 50S FAR SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
SURFACE HIGH PRESSURE TO BUILD ACROSS THE GREAT LAKES ON THURSDAY.
DRY AIRMASS WILL RESULT IN MOSTLY SUNNY SKY CONDITIONS. EXPECT TEMPS
TO BE SLIGHTLY BELOW NORMAL. AFTER A COOL START TO THE DAY EXPECT
HIGHS TO RANGE FROM NEAR 70 NE TO THE MID 70S SW.
SURFACE HIGH PRESSURE TO SLIDE OFF TO THE EAST THURSDAY NIGHT.
EXPECT MAINLY CLEAR SKIES WITH ONLY SOME THIN HIGH LEVEL CLOUDS
SPILLING IN. HAVE FCST TEMPS RANGING FROM MID 40S NORTHEAST TO THE
LOWER 50S SOUTH.
MID/UPR LEVEL RIDGE TO BUILD INTO OHIO ON FRIDAY. EXPECT TO SEE A
GOOD DEAL OF SUNSHINE WITH JUST SOME HIGH LEVEL CLOUDINESS. UNDER
THE INFLUENCE OF WAA TEMPS WILL WARM TO VALUES ABOVE NORMAL. HAVE
FCST HIGHS FROM NEAR 80 NORTH TO THE LOWER 80S SOUTH.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
WITH AN UPPER RIDGE BUILDING OVERHEAD AND SURFACE HIGH PRESSURE
CENTERED TO THE EAST...A PERIOD OF DRY WEATHER IS INDICATED FOR
SATURDAY THROUGH MONDAY. CONFIDENCE IS RATHER HIGH FOR THIS TIME
FRAME DUE TO MODEL CONSISTENCY FROM RUN TO RUN.
AN UPPER LOW IS SHOWN TO DEVELOP OVER THE MISSISSIPPI VALLEY ON
TUESDAY...ACCOMPANIED BY INCREASING MOISTURE. THE LOW IS FORECAST TO
MOVE TO INDIANA ON WEDNESDAY. MODELS HAVE BEEN INCONSISTENT WITH THE
PATH OF THE UPPER LOW...MAKING THIS PART OF THE FORECAST LESS
CERTAIN. WENT WITH A CHANCE OF THUNDERSTORMS IN WESTERN COUNTIES ON
TUESDAY...EXPANDING TO THE WHOLE AREA ON WEDNESDAY.
WITH THE AREA IN A SOUTHERLY FLOW AND WITH CONSIDERABLE SUNSHINE TO
START...TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD. HIGHS
WILL BE MAINLY IN THE 80S SATURDAY THROUGH MONDAY...WITH INCREASING
CLOUDS AND POSSIBLE PRECIPITATION CAUSING READINGS TO SLIP TO THE
MID AND UPPER 70S BY WEDNESDAY.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
A WEAK COLD FRONT WILL SLIP SOUTH OF THE OHIO RIVER BY THIS
EVENING. LIMITED MOISTURE WITH THE FRONT MAY BRING AN ISOLATED
SHOWER OR THUNDERSTORM BEFORE PASSAGE. AFTER PASSAGE...MAINLY
CLEAR SKIES ARE EXPECTED. WINDS WILL VEER TO THE NORTH AND WILL BE
LOCALLY GUSTY WITH FRONTAL PASSAGE. HIGH PRESSURE IS EXPECTED TO
BUILD SOUTH INTO THE GREAT LAKES AND OHIO VALLEY THROUGH THURSDAY.
WINDS WILL VEER TO AN EASTERLY DIRECTION AND WILL RANGE BETWEEN 8
AND 14 KNOTS ON THURSDAY.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
145 PM EDT WED MAY 16 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON WEDNESDAY. HIGH
PRESSURE WILL THEN BUILD IN FOR THE REST OF THE WEEK...WITH
GRADUALLY WARMING TEMPERATURES INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WEAK COLD FRONT WILL DROP SOUTHWARD THROUGH THE REGION THIS
AFTERNOON. THE FRONT SEEMS TO BE JUST A TAD SLOWER THAN PREVIOUSLY
FORECAST. FORECAST CHALLENGES WITH THIS FRONT REVOLVE AROUND
CHANCES OF PCPN AND TEMPERATURES. FORCING IS WEAK WITH THE FRONT.
ALSO...INSTABILITY WILL BE LIMITED...MORE SO THAN WHAT THE NAM-WRF
AND GFS ARE INDICATING AS THEY HAVE BEEN POOLING MUCH HIGHER
DEWPOINTS AHEAD OF THE FRONT THAN WHAT HAS BEEN ACTUALLY
OCCURRING. THUS...HAVE SIDED WITH THE MORE LOWER DEWPOINT VALUES
WITH THE RAP MODEL WHICH YIELD MLCAPES OF ABOUT 1000 J/KG LATE IN
THE DAY ACRS THE SRN ZONES. AS A RESULT...HAVE PLACED A 20 POP
AHEAD OF THE FRONT ACRS THE NORTH FOR AN ISOLATED SHOWER THROUGH
LATE AFTN. THEREAFTER...HAVE PLACED A 20 POP IN THE SRN ZONES FOR
AN ISOLATED SHOWER/THUNDERSTORM LATE IN THE DAY INTO THE EARLY
EVENING HOURS. FRONTAL PASSAGE WILL BE DELINEATED WITH A WIND
SHIFT TO THE NORTH ALONG WITH SOME GUSTS AS HIGH AS 25 MPH.
TEMPERATURES WILL BE TRICKY GIVEN CLOUDS AND CAA ASSOCIATED WITH
AND JUST BEHIND THE FRONT. HIGHS TODAY SHOULD RANGE FROM NEAR 70
IN THE FAR NW TO THE LOWER 80S IN THE SOUTH.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
THE COLD FRONT AND ANY REMAINING THUNDERSTORMS WILL SHIFT SOUTH OF
OUR AREA THIS EVENING. IN THE WAKE OF THE FRONT...COLD ADVECTION
WILL LIKELY KEEP WINDS UP AROUND 10 MPH FOR MOST OF THE OVERNIGHT
PERIOD. WITH THE COOLER AND DRIER AIRMASS MOVING INTO
PLACE...OVERNIGHT LOWS WILL RUN ABOUT 10 DEGREES COOLER THAN THIS
MORNINGS VALUES. HAVE FORECAST LOW A DEGREE OR TWO ABOVE
GUIDANCE...MAINLY DUE TO WINDS NOT GOING COMPLETELY CALM
OVERNIGHT.
THURSDAY THROUGH FRIDAY...RIDGING WILL DOMINATE OUR WEATHER WITH
ONLY SCATTERED CLOUDS...NO PRECIPITATION...AND GRADUALLY
REBOUNDING TEMPERATURES. MAXIMUM TEMPERATURES WILL BE NEAR CLIMO
ON THURSDAY. THURSDAY NIGHT WILL BE COOL...WITH UPPER 40S TO LOW
50S WITH CLEAR SKIES...CALM WINDS...AND DEWPOINTS IN THE 30S TO
40S.
THE SURFACE RIDGE WILL SHIFT EAST ON FRIDAY...AND MID LEVEL
HEIGHTS AND CORRESPONDING THICKNESSES WILL INCREASE. THIS WILL
LEAD TO HIGH TEMPERATURES ON FRIDAY SEVERAL DEGREES WARMER THAN
THURSDAY...UNDER MOSTLY CLEAR SKIES.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS ARE IN GENERAL AGREEMENT FOR THE LONG TERM TIME FRAME. DRY
CONDITIONS WILL BE PRESENT TO START OUT THE LONG TERM WITH HIGH
PRESSURE IN PLACE. PREVIOUS MODEL RUNS WERE TRYING TO ALLOW FOR A
FEW THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON SATURDAY AND
SUNDAY. MOST RECENT MODEL RUNS HAVE COME IN DRIER FOR THE WEEKEND
AND BELIEVE THAT WITH THE RIDGE IN PLACE THAT DRY CONDITIONS WILL
PREVAIL. TEMPERATURES WILL GRADUALLY INCREASE THROUGH THE WEEKEND
WITH WARM SOUTHERLY FLOW. TEMPERATURES ON MONDAY WILL BE SIMILAR TO
SUNDAY WITH SOME LOCATIONS A DEGREE OR TWO COOLER THAN SUNDAY DUE TO
AN INCREASE IN CLOUD COVER. MODELS CONTINUE TO SLOW DOWN THE SYSTEM
FOR MONDAY AND TUESDAY AND THEREFORE LIMITED PRECIPITATION CHANCES
ON MONDAY AND MOST OF MONDAY NIGHT TO A SLIGHT CHANCE. EXPECT
TEMPERATURES TO BE A LITTLE COOLER ON TUESDAY WITH INCREASED
PRECIPITATION AND CLOUD COVER ACROSS THE FA.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A WEAK COLD FRONT WILL SLIP SOUTH OF THE OHIO RIVER BY THIS
EVENING. LIMITED MOISTURE WITH THE FRONT MAY BRING AN ISOLATED
SHOWER OR THUNDERSTORM BEFORE PASSAGE. AFTER PASSAGE...MAINLY
CLEAR SKIES ARE EXPECTED. WINDS WILL VEER TO THE NORTH AND WILL BE
LOCALLY GUSTY WITH FRONTAL PASSAGE. HIGH PRESSURE IS EXPECTED TO
BUILD SOUTH INTO THE GREAT LAKES AND OHIO VALLEY THROUGH THURSDAY.
WINDS WILL VEER TO AN EASTERLY DIRECTION AND WILL RANGE BETWEEN 8
AND 14 KNOTS ON THURSDAY.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...HICKMAN
SHORT TERM...LATTO
LONG TERM...NOVAK
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1119 AM EDT WED MAY 16 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON WEDNESDAY. HIGH
PRESSURE WILL THEN BUILD IN FOR THE REST OF THE WEEK...WITH
GRADUALLY WARMING TEMPERATURES INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WEAK COLD FRONT WILL DROP SOUTHWARD THROUGH THE REGION THIS
AFTERNOON. THE FRONT SEEMS TO BE JUST A TAD SLOWER THAN PREVIOUSLY
FORECAST. FORECAST CHALLENGES WITH THIS FRONT REVOLVE AROUND
CHANCES OF PCPN AND TEMPERATURES. FORCING IS WEAK WITH THE FRONT.
ALSO...INSTABILITY WILL BE LIMITED...MORE SO THAN WHAT THE NAM-WRF
AND GFS ARE INDICATING AS THEY HAVE BEEN POOLING MUCH HIGHER
DEWPOINTS AHEAD OF THE FRONT THAN WHAT HAS BEEN ACTUALLY
OCCURRING. THUS...HAVE SIDED WITH THE MORE LOWER DEWPOINT VALUES
WITH THE RAP MODEL WHICH YIELD MLCAPES OF ABOUT 1000 J/KG LATE IN
THE DAY ACRS THE SRN ZONES. AS A RESULT...HAVE PLACED A 20 POP
AHEAD OF THE FRONT ACRS THE NORTH FOR AN ISOLATED SHOWER THROUGH
LATE AFTN. THEREAFTER...HAVE PLACED A 20 POP IN THE SRN ZONES FOR
AN ISOLATED SHOWER/THUNDERSTORM LATE IN THE DAY INTO THE EARLY
EVENING HOURS. FRONTAL PASSAGE WILL BE DELINEATED WITH A WIND
SHIFT TO THE NORTH ALONG WITH SOME GUSTS AS HIGH AS 25 MPH.
TEMPERATURES WILL BE TRICKY GIVEN CLOUDS AND CAA ASSOCIATED WITH
AND JUST BEHIND THE FRONT. HIGHS TODAY SHOULD RANGE FROM NEAR 70
IN THE FAR NW TO THE LOWER 80S IN THE SOUTH.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
THE COLD FRONT AND ANY REMAINING THUNDERSTORMS WILL SHIFT SOUTH OF
OUR AREA THIS EVENING. IN THE WAKE OF THE FRONT...COLD ADVECTION
WILL LIKELY KEEP WINDS UP AROUND 10 MPH FOR MOST OF THE OVERNIGHT
PERIOD. WITH THE COOLER AND DRIER AIRMASS MOVING INTO
PLACE...OVERNIGHT LOWS WILL RUN ABOUT 10 DEGREES COOLER THAN THIS
MORNINGS VALUES. HAVE FORECAST LOW A DEGREE OR TWO ABOVE
GUIDANCE...MAINLY DUE TO WINDS NOT GOING COMPLETELY CALM
OVERNIGHT.
THURSDAY THROUGH FRIDAY...RIDGING WILL DOMINATE OUR WEATHER WITH
ONLY SCATTERED CLOUDS...NO PRECIPITATION...AND GRADUALLY
REBOUNDING TEMPERATURES. MAXIMUM TEMPERATURES WILL BE NEAR CLIMO
ON THURSDAY. THURSDAY NIGHT WILL BE COOL...WITH UPPER 40S TO LOW
50S WITH CLEAR SKIES...CALM WINDS...AND DEWPOINTS IN THE 30S TO
40S.
THE SURFACE RIDGE WILL SHIFT EAST ON FRIDAY...AND MID LEVEL
HEIGHTS AND CORRESPONDING THICKNESSES WILL INCREASE. THIS WILL
LEAD TO HIGH TEMPERATURES ON FRIDAY SEVERAL DEGREES WARMER THAN
THURSDAY...UNDER MOSTLY CLEAR SKIES.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS ARE IN GENERAL AGREEMENT FOR THE LONG TERM TIME FRAME. DRY
CONDITIONS WILL BE PRESENT TO START OUT THE LONG TERM WITH HIGH
PRESSURE IN PLACE. PREVIOUS MODEL RUNS WERE TRYING TO ALLOW FOR A
FEW THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON SATURDAY AND
SUNDAY. MOST RECENT MODEL RUNS HAVE COME IN DRIER FOR THE WEEKEND
AND BELIEVE THAT WITH THE RIDGE IN PLACE THAT DRY CONDITIONS WILL
PREVAIL. TEMPERATURES WILL GRADUALLY INCREASE THROUGH THE WEEKEND
WITH WARM SOUTHERLY FLOW. TEMPERATURES ON MONDAY WILL BE SIMILAR TO
SUNDAY WITH SOME LOCATIONS A DEGREE OR TWO COOLER THAN SUNDAY DUE TO
AN INCREASE IN CLOUD COVER. MODELS CONTINUE TO SLOW DOWN THE SYSTEM
FOR MONDAY AND TUESDAY AND THEREFORE LIMITED PRECIPITATION CHANCES
ON MONDAY AND MOST OF MONDAY NIGHT TO A SLIGHT CHANCE. EXPECT
TEMPERATURES TO BE A LITTLE COOLER ON TUESDAY WITH INCREASED
PRECIPITATION AND CLOUD COVER ACROSS THE FA.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT IS PUSHING DOWN TOWARD THE AREA THIS MORNING...
CURRENTLY STRETCHING FROM NORTHWEST OHIO ACROSS NORTHERN INDIANA
INTO CENTRAL ILLINOIS. SOME DEBRIS CLOUDINESS AHEAD OF THE FRONT
WILL LIKELY WORK ACROSS THE TAF SITES THROUGH MID MORNING. AS THE
FRONT MOVES SOUTH ACROSS THE AREA...THE AIRMASS ALONG AND SOUTH OF
THE FRONT WILL BEGIN TO DESTABILIZE THROUGH THIS AFTERNOON. THIS
WILL LIKELY LEAD TO SOME CU DEVELOPMENT LATE THIS MORNING INTO
EARLY AFTERNOON. EVENTUALLY SOME SHOWERS AND A FEW THUNDERSTORMS
WILL LIKELY DEVELOP AHEAD OF THE FRONT THIS AFTERNOON.
HOWEVER...BY THIS TIME THE FRONT SHOULD BE SOUTH OF TH TAF SITES
SO WILL KEEP PCPN OUT OF THE FORECAST. SKIES SHOULD THEN CLEAR ON
THE BACK SIDE OF THE FRONT LATER THIGH AFTERNOON INTO THIS
EVENING.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...HICKMAN
SHORT TERM...LATTO
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1036 PM EDT THU MAY 17 2012
.SYNOPSIS...
AN UPPER LEVEL LOW WILL FORM OVER SOUTH CAROLINA...AND WILL MOVE TO
THE NORTH CAROLINA COAST...WHERE IT WILL LINGER INTO EARLY NEXT
WEEK. HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND REMAIN THROUGH
MONDAY. A COLD FRONT WILL APPROACH THE AREA FROM THE WEST ON
TUESDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 1035 PM...CONVECTION REMAINING LIMITED MAINLY TO THE MTNS ATTM
WITH ISOLATED CELLS FROM TIME TO TIME ELSEWHERE. THE RAP AS
GENERALLY COME IN LINE WITH THE OTHER MESOSCALE MDLS KEEPING BEST
CHC OF CONVECTION OVER THE MTNS THRU THE EARLY OVERNIGHT. IT REMAINS
TO BE SEEN IF WIDESPREAD CONVECTION REDEVELOPS IN THE NEXT COUPLE OF
HOURS AS THE HRRR SHOWS. EXPECT A BRIEF INCREASE IN COVERAGE BEFORE
MIDNIGHT THEN DIMINSIHING...WITH ONLY A CELL OR TWO OUTSIDE OF THE
MTNS. PATCHY FOG HAS GOTTEN AN EARLY START IN THE MORE FOG PRONE
LOCATIONS...SO HAVE ADDED MORE PATCHY FOG OUTSIDE OF THE MTNS
OVERNIGHT. LOWER CLOUDS ARE MOVING IN...DEVELOPING NEARLY AS
EXPECTED OVER THE NC PIEDMONT. STILL EXPECT THE CLOUDS TO EXPAND
WEST AND SOUTHWEST OVERNIGHT.
AS OF 800 PM...CONVECTION HAS DIMINISHED OUTSIDE OF THE MTNS WITH
THE LOSS OF HEATING BUT CONTINUES OVER THE MTNS. CANNOT RULE OUT AN
ISOLATED STORM OUTSIDE OF THE MTNS THIS EVENING...BUT BEST CHC WILL
BE TO OUR SE CLOSER TO THE UPPER LOW AND TROF. OTHER THAN THE
OUTLIER RAP... MESOSCALE MDLS SHOW BEST CHC FOR CONVECTION OVER THE
MTNS THRU MIDNIGHT THEN DISSIPATING BY MORNING. HAVE GONE THIS ROUTE
WITH POP GIVEN THE CURRENT CONDITIONS. UPDATED LOWS WITH THE LATEST
GUIDANCE WHICH SEEMS TO TAKE INTO ACCOUNT THE LINGERING CLOUDS
EXPECTED OVERNIGHT. THIS RAISES LOWS BY A COUPLE OF DEGREES IN MANY
LOCATIONS. EXPECT ONLY PATCHY FOG NEAR BODIES OF WATER OUTSIDE OF
THE MTNS WITH THE INCREASE IN LOW CLOUDS FROM THE EAST OVERNIGHT.
MTN VALLEYS WILL SEE PATCHY DENSE FOG...ESPECIALLY THE LITTLE TN
VALLEY.
PREVIOUS DISCUSSION...WATER VAPOR IMAGERY AND THE LATEST RAP MODEL
RUN SHOW A NE TO SW ORIENTED UPPER LOW STRETCHED OVER THE MIDLANDS
OF SOUTH CAROLINA...BACK ACROSS SOUTHEAST GEORGIA. A SPOKE OF PVA ON
THE WEST SIDE OF THE LOW IS HELPING TO ORGANIZE STRONG TO SEVERE
CONVECTION ACROSS THE SOUTHERN PART OF THE UPSTATE.
ELSEWHERE...OTHER STORMS WERE DEVELOPING OVER THE BLUE RIDGE OF NE
GA AND SW NC. SOMEWHAT DRIER AIR HAS PUSHED INTO THE NRN PIEDMONT
AND FOOTHILLS OF NE...BUT AREAS TO THE SOUTH REMAIN QUITE UNSTABLE
WITH SB-CAPE VALUES RUNNING FROM 1500-2000 J/JG. OUR LOCAL
WORKSTATION WRF...THE NCEP 4KM WRF AND THE HRRR ALL AGREE IN
DEVELOPING CONVECTION OVER MUCH OF THE UPSTATE...SOUTHERN NC MTNS
AND FOOTHILLS AND NE GA INTO THE EVENING HOURS. THIS WOULD BE
SIMILAR TO WHAT HAPPENED LAST NIGHT. CONFIDENCE IN THIS DEVELOPMENT
IS FAIRLY HIGH...AND POPS WILL BE PUSHED UP TO 50 PERCENT ACROSS THE
I-85 CORRIDOR AND UP INTO THE WRN NC FOOTHILLS FOR THE EVENING
HOURS. COOL MID-LEVEL TEMPS AND DRY AIR ALOFT WILL CONTINUE TO
SUPPORT SEVERE WIND AND HAIL EVENTS.
A BACK DOOR COLD FRONT WILL CROSS THE REGION LATE TONIGHT. THE NAM
MIXES DEWPOINTS INTO THE U40S TO L50S ACROSS THE NC FOOTHILLS AND
PIEDMONT AND THE ERN UPSTATE. THIS SHOULD FINALLY END THE THREAT OF
STORMS FOR THESE AREAS. BACK ACROSS THE MOUNTAINS...ESPECIALLY
CLOSER TO THE TN LINE...SCT CONVECTION SHOULD DEVELOP AGAIN TMRW
WHERE LLVL MOISTURE CONVERGENCE WILL BE MAXIMIZED.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AT 1430 EDT THURSDAY...A CLOSED UPPER LOW...PART OF AN EAST COAST
REX ...WILL BE LOCATED NEAR THE NC COAST ON FRIDAY NIGHT AND
SATURDAY. ON SUNDAY THIS FEATURE RETROGRADES SLIGHTLY INLAND. THE
MODELS SHOW DRIER AIR MOVING SW INTO OUR AREA ON THE BACK SIDE OF
THE LOW FRIDAY NIGHT AND SATURDAY....WHILE SOME MOISTURE LINGERS
ALONG THE BLUE RIDGE. ON SATURDAY NIGHT THE NAM SHOWS MOISTURE
SPREADING WEST ACROSS THE INTERSTATE 77 CORRIDOR TO THE NC BLUE
RIDGE...WHILE THE GFS REMAINS RATHER DRY UNTIL SUNDAY NIGHT.
POPS WILL INITIALLY BE QUITE LOW AND FOCUSED ALONG THE BLUE
RIDGE...THEN WILL INCREASE SLIGHTLY FROM THE EAST TOWARD SUNDAY...
BUT REMAINING RATHER LOW AS CONFIDENCE IS LIMITED ON THE AMOUNT AND
TIMING OF MOISTURE ENCROACHMENT FROM THE EAST. TEMPERATURES WILL
GENERALLY BE SLIGHTLY BELLOW NORMAL UNDER THE UPPER LOW HEIGHT
ANOMALY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AT 1430 EDT THURSDAY...A LONGWAVE TROUGH WILL PROGRESS ACROSS THE
EASTERN USA FROM MONDAY THROUGH WEDNESDAY...PROGRESSING OFFSHORE ON
THURSDAY WHEN A LONGWAVE RIDGE AXIS CROSSES THE MS RIVER VALLEY. A
CLOSED UPPER LOW WILL REMAIN NEAR THE CAROLINA COAST ON MONDAY. THIS
LOW FILLS AND DRIFTS NORTHEAST ON TUESDAY. A SHORTWAVE TROUGH DROPS
SOUTHEAST OVER THE SOUTHERN APPALACHIANS LATE TUESDAY...MOVING OFF
TO THE EAST ON WEDNESDAY.
SURFACE HIGH PRESSURE WILL BE OVER OUR ARE ON MONDAY...BETWEEN A
COASTAL LOW AND A COLD FRONT IN THE MS RIVER VALLEY. CONFIDENCE IS
LIMITED ON THE WESTERN EXTENT OF MOISTURE THAT WILL WRAP AROUND THE
COASTAL LOW TOWARD THE SOUTHERN APPALACHIANS...AND THE RESULTANT
POPS. THE COLD FRONT TO OUR WEST REACHES THE SOUTHERN APPALACHIANS
ON TUESDAY WHILE WEAKENING...WITH THE REMAINS OF THE BOUNDARY
SUPPORTING LENDING SUPPORT TO AT LEAST SMALL POPS. WEDNESDAY AND
THURSDAY FIND OUR AREA UNDER WEAK HIGH PRESSURE...BUT THE MODELS
DEPICT SOME AMOUNT OF LINGERING MOISTURE...OSTENSIBLY ASSOCIATED
WITH THE REMAINS OF THE FORMER FRONT. WITH GULF INFLOW EVENTUALLY
SETTING UP TO OUR WEST...SMALL POPS WILL BE MAINTAINED INTO
THURSDAY...ESPECIALLY IN THE WEST. TEMPERATURES WILL BE SLIGHTLY
ABOVE NORMAL IN MINOR HEIGHTS RISES BEHIND THE DEPARTING UPPER LOW.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AT KCLT...EXPECT ANY SIGNIFICANT CONVECTION TO REMAIN EAST AND SOUTH
OF THE AIRFIELD THIS EVENING BEFORE DISSIPATING OVERNIGHT. CANNOT
RULE OUT A ROGUE CELL DEVELOPING...BUT CHC TOO LOW FOR MENTION ATTM.
EXPECT LOW VFR THEN MVFR TO MOVE IN ON THE LOW LEVEL ELY FLOW AS
MOISTURE INCREASES OVERNIGHT. THIS SHUD LIFT QUICKLY AFTER SUNRISE.
HOWEVER...GUSTY NNE WINDS DEVELOP AS MIXING TAPS THE STRONGER ELY
FLOW JUST ABOVE THE SFC. THE GUSTS SHUD DIMINISH AROUND NOON WITH
SCT HIGH BASED CU DEVELOPING. DRIER ATMOS MOVING IN SHUD SQUELCH ANY
CONVECTION.
ELSEWHERE...BEST CHC FOR ANY CONVECTION THIS EVENING WILL BE AT
KAVL...BUT CANNOT COMPLETELY RULE OUT A ROGUE CELL ELSEWHERE.
CONVECTION WILL LINGER THRU MIDNIGHT THEN DISSIPATE BEFORE DAYBREAK.
EXPECT LOW VFR THEN MVFR TO DEVELOP TOWARD MORNING ON ELY LOW LEVEL
FLOW AND INCREASING MOISTURE. KAVL HAS THE BEST CHANCE FOR ANY MVFR
FOG OVERNIGHT. EXPECT THE MVFR TO LIFT SHORTLY AFTER DAYBREAK.
HOWEVER...GUSTY NELY WINDS WILL DEVELOP OVER THE SC SITES AS MIXING
TAPS THE STRONGER WINDS JUST ABOVE THE SFC...LESS WIND KAVL/KHKY.
GUSTS DIMINISH FOR THE AFTERNOON WITH HIGH BASED CU DEVELOPING. KAVL
HAS THE BEST CHC FOR ANY DIURNAL CONVECTION...BUT CHC TOO LOW TO
INCLUDE ATTM.
OUTLOOK...DRYING OVER THE WEEKEND SHUD KEEP A LID ON CONVECTION.
MRNG FOG WILL BE PSBL...ESP MTN VALLEYS AND NEAR LAKES/RIVERS.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JAT
NEAR TERM...MCAVOY/RWH
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...RWH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
804 PM EDT THU MAY 17 2012
.SYNOPSIS...
AN UPPER LEVEL LOW WILL FORM OVER SOUTH CAROLINA...AND WILL MOVE TO
THE NORTH CAROLINA COAST...WHERE IT WILL LINGER INTO EARLY NEXT
WEEK. HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND REMAIN THROUGH
MONDAY. A COLD FRONT WILL APPROACH THE AREA FROM THE WEST ON
TUESDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 800 PM...CONVECTION HAS DIMINISHED OUTSIDE OF THE MTNS WITH
THE LOSS OF HEATING BUT CONTINUES OVER THE MTNS. CANNOT RULE OUT AN
ISOLATED STORM OUTSIDE OF THE MTNS THIS EVENING...BUT BEST CHC WILL
BE TO OUR SE CLOSER TO THE UPPER LOW AND TROF. OTHER THAN THE
OUTLIER RAP... MESOSCALE MDLS SHOW BEST CHC FOR CONVECTION OVER THE
MTNS THRU MIDNIGHT THEN DISSIPATING BY MORNING. HAVE GONE THIS ROUTE
WITH POP GIVEN THE CURRENT CONDITIONS. UPDATED LOWS WITH THE LATEST
GUIDANCE WHICH SEEMS TO TAKE INTO ACCOUNT THE LINGERING CLOUDS
EXPECTED OVERNIGHT. THIS RAISES LOWS BY A COUPLE OF DEGREES IN MANY
LOCATIONS. EXPECT ONLY PATCHY FOG NEAR BODIES OF WATER OUTSIDE OF
THE MTNS WITH THE INCREASE IN LOW CLOUDS FROM THE EAST OVERNIGHT.
MTN VALLEYS WILL SEE PATCHY DENSE FOG...ESPECIALLY THE LITTLE TN
VALLEY.
PREVIOUS DISCUSSION...WATER VAPOR IMAGERY AND THE LATEST RAP MODEL
RUN SHOW A NE TO SW ORIENTED UPPER LOW STRETCHED OVER THE MIDLANDS
OF SOUTH CAROLINA...BACK ACROSS SOUTHEAST GEORGIA. A SPOKE OF PVA ON
THE WEST SIDE OF THE LOW IS HELPING TO ORGANIZE STRONG TO SEVERE
CONVECTION ACROSS THE SOUTHERN PART OF THE UPSTATE.
ELSEWHERE...OTHER STORMS WERE DEVELOPING OVER THE BLUE RIDGE OF NE
GA AND SW NC. SOMEWHAT DRIER AIR HAS PUSHED INTO THE NRN PIEDMONT
AND FOOTHILLS OF NE...BUT AREAS TO THE SOUTH REMAIN QUITE UNSTABLE
WITH SB-CAPE VALUES RUNNING FROM 1500-2000 J/JG. OUR LOCAL
WORKSTATION WRF...THE NCEP 4KM WRF AND THE HRRR ALL AGREE IN
DEVELOPING CONVECTION OVER MUCH OF THE UPSTATE...SOUTHERN NC MTNS
AND FOOTHILLS AND NE GA INTO THE EVENING HOURS. THIS WOULD BE
SIMILAR TO WHAT HAPPENED LAST NIGHT. CONFIDENCE IN THIS DEVELOPMENT
IS FAIRLY HIGH...AND POPS WILL BE PUSHED UP TO 50 PERCENT ACROSS THE
I-85 CORRIDOR AND UP INTO THE WRN NC FOOTHILLS FOR THE EVENING
HOURS. COOL MID-LEVEL TEMPS AND DRY AIR ALOFT WILL CONTINUE TO
SUPPORT SEVERE WIND AND HAIL EVENTS.
A BACK DOOR COLD FRONT WILL CROSS THE REGION LATE TONIGHT. THE NAM
MIXES DEWPOINTS INTO THE U40S TO L50S ACROSS THE NC FOOTHILLS AND
PIEDMONT AND THE ERN UPSTATE. THIS SHOULD FINALLY END THE THREAT OF
STORMS FOR THESE AREAS. BACK ACROSS THE MOUNTAINS...ESPECIALLY
CLOSER TO THE TN LINE...SCT CONVECTION SHOULD DEVELOP AGAIN TMRW
WHERE LLVL MOISTURE CONVERGENCE WILL BE MAXIMIZED.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AT 1430 EDT THURSDAY...A CLOSED UPPER LOW...PART OF AN EAST COAST
REX ...WILL BE LOCATED NEAR THE NC COAST ON FRIDAY NIGHT AND
SATURDAY. ON SUNDAY THIS FEATURE RETROGRADES SLIGHTLY INLAND. THE
MODELS SHOW DRIER AIR MOVING SW INTO OUR AREA ON THE BACK SIDE OF
THE LOW FRIDAY NIGHT AND SATURDAY....WHILE SOME MOISTURE LINGERS
ALONG THE BLUE RIDGE. ON SATURDAY NIGHT THE NAM SHOWS MOISTURE
SPREADING WEST ACROSS THE INTERSTATE 77 CORRIDOR TO THE NC BLUE
RIDGE...WHILE THE GFS REMAINS RATHER DRY UNTIL SUNDAY NIGHT.
POPS WILL INITIALLY BE QUITE LOW AND FOCUSED ALONG THE BLUE
RIDGE...THEN WILL INCREASE SLIGHTLY FROM THE EAST TOWARD SUNDAY...
BUT REMAINING RATHER LOW AS CONFIDENCE IS LIMITED ON THE AMOUNT AND
TIMING OF MOISTURE ENCROACHMENT FROM THE EAST. TEMPERATURES WILL
GENERALLY BE SLIGHTLY BELLOW NORMAL UNDER THE UPPER LOW HEIGHT
ANOMALY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AT 1430 EDT THURSDAY...A LONGWAVE TROUGH WILL PROGRESS ACROSS THE
EASTERN USA FROM MONDAY THROUGH WEDNESDAY...PROGRESSING OFFSHORE ON
THURSDAY WHEN A LONGWAVE RIDGE AXIS CROSSES THE MS RIVER VALLEY. A
CLOSED UPPER LOW WILL REMAIN NEAR THE CAROLINA COAST ON MONDAY. THIS
LOW FILLS AND DRIFTS NORTHEAST ON TUESDAY. A SHORTWAVE TROUGH DROPS
SOUTHEAST OVER THE SOUTHERN APPALACHIANS LATE TUESDAY...MOVING OFF
TO THE EAST ON WEDNESDAY.
SURFACE HIGH PRESSURE WILL BE OVER OUR ARE ON MONDAY...BETWEEN A
COASTAL LOW AND A COLD FRONT IN THE MS RIVER VALLEY. CONFIDENCE IS
LIMITED ON THE WESTERN EXTENT OF MOISTURE THAT WILL WRAP AROUND THE
COASTAL LOW TOWARD THE SOUTHERN APPALACHIANS...AND THE RESULTANT
POPS. THE COLD FRONT TO OUR WEST REACHES THE SOUTHERN APPALACHIANS
ON TUESDAY WHILE WEAKENING...WITH THE REMAINS OF THE BOUNDARY
SUPPORTING LENDING SUPPORT TO AT LEAST SMALL POPS. WEDNESDAY AND
THURSDAY FIND OUR AREA UNDER WEAK HIGH PRESSURE...BUT THE MODELS
DEPICT SOME AMOUNT OF LINGERING MOISTURE...OSTENSIBLY ASSOCIATED
WITH THE REMAINS OF THE FORMER FRONT. WITH GULF INFLOW EVENTUALLY
SETTING UP TO OUR WEST...SMALL POPS WILL BE MAINTAINED INTO
THURSDAY...ESPECIALLY IN THE WEST. TEMPERATURES WILL BE SLIGHTLY
ABOVE NORMAL IN MINOR HEIGHTS RISES BEHIND THE DEPARTING UPPER LOW.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AT KCLT...EXPECT ANY SIGNIFICANT CONVECTION TO REMAIN EAST AND SOUTH
OF THE AIRFIELD THIS EVENING BEFORE DISSIPATING OVERNIGHT. CANNOT
RULE OUT A ROGUE CELL DEVELOPING...BUT CHC TOO LOW FOR MENTION ATTM.
EXPECT LOW VFR THEN MVFR TO MOVE IN ON THE LOW LEVEL ELY FLOW AS
MOISTURE INCREASES OVERNIGHT. THIS SHUD LIFT QUICKLY AFTER SUNRISE.
HOWEVER...GUSTY NNE WINDS DEVELOP AS MIXING TAPS THE STRONGER ELY
FLOW JUST ABOVE THE SFC. THE GUSTS SHUD DIMINISH AROUND NOON WITH
SCT HIGH BASED CU DEVELOPING. DRIER ATMOS MOVING IN SHUD SQUELCH ANY
CONVECTION.
ELSEWHERE...BEST CHC FOR ANY CONVECTION THIS EVENING WILL BE AT
KAVL...BUT CANNOT COMPLETELY RULE OUT A ROGUE CELL ELSEWHERE.
CONVECTION WILL LINGER THRU MIDNIGHT THEN DISSIPATE BEFORE DAYBREAK.
EXPECT LOW VFR THEN MVFR TO DEVELOP TOWARD MORNING ON ELY LOW LEVEL
FLOW AND INCREASING MOISTURE. KAVL HAS THE BEST CHANCE FOR ANY MVFR
FOG OVERNIGHT. EXPECT THE MVFR TO LIFT SHORTLY AFTER DAYBREAK.
HOWEVER...GUSTY NELY WINDS WILL DEVELOP OVER THE SC SITES AS MIXING
TAPS THE STRONGER WINDS JUST ABOVE THE SFC...LESS WIND KAVL/KHKY.
GUSTS DIMINISH FOR THE AFTERNOON WITH HIGH BASED CU DEVELOPING. KAVL
HAS THE BEST CHC FOR ANY DIURNAL CONVECTION...BUT CHC TOO LOW TO
INCLUDE ATTM.
OUTLOOK...DRYING OVER THE WEEKEND SHUD KEEP A LID ON CONVECTION.
MRNG FOG WILL BE PSBL...ESP MTN VALLEYS AND NEAR LAKES/RIVERS.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JAT
NEAR TERM...MCAVOY/RWH
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...RWH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
242 PM EDT WED MAY 16 2012
.SYNOPSIS...
A SLOW MOVING UPPER LEVEL AREA OF LOW PRESSURE WILL MOVE EAST ACROSS
THE AREA THROUGH THURSDAY. STRONG HIGH PRESSURE WILL THEN BUILD IN
FROM THE NORTH ON FRIDAY AND REMAIN THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
THE CURRENT WATER VAPOR IMAGERY AND THE LATEST RAP RUN SHOW A WEAK
H5 TROUGH ORIENTED NE TO SW ACROSS THE SRN APPALACHIANS. UPPER
DIVERGENCE ON THE EAST SIDE OF THE TROUGH...WHICH HAS HELPED SPAWN
WIDESPREAD THUNDERSTORM ACTIVITY ALONG THE COAST...IS RESULTING IN
A RAGGED BAROCLINIC LEAF BACK ACROSS THE UPSTATE AND SRN NC
PIEDMONT. THIS HAS CUT DOWN A BIT ON THE INSOLATION ACROSS THE FA
THIS AFTN. EVEN SO...ISOLATED SHRA AND A FEW TSTMS HAVE DEVELOPED
OVER THE REGION...THOUGH COVERAGE HAS BEEN A LITTLE LESS THAN
EXPECTED. THE CONVECTIVE COVERAGE IS EXPECTED TO INCREASE SOME
DURING THE LATE AFTN HOURS...THOUGH NOTHING HIGHER THAN LOW CHANCE
POPS HAS BEEN CARRIED OWING TO THE WEAK SHEAR. WHILE THE STORMS
SHOULD GO INTO THE LATE EVENING HOURS...WE ARE NOT EXPECTING
CONVECTION TO LAST AS LONG AS IT DID LAST NIGHT. THERE IS STILL A
CHANCE THAT ONE OR TWO OF THE STORMS WILL REACH SEVERE
LIMITS...PARTICULARLY ALONG AND SOUTH OF I-85 WHERE THE SHEAR IS A
LITTLE STRONGER...AT LEAST UNTIL AROUND 00 UTC.
THE WEAK TROUGH WILL SETTLE ACROSS THE MIDLANDS LATE TONIGHT AND ON
THURSDAY...PUTTING THE FA UNDER NVA ALOFT. THE TROUGH PASSAGE WILL
BRING A WEAK COLD FRONT THROUGH THE AREA. THE FRONT WILL PUSH IN
FROM THE NE LATE TONIGHT...TURNING THE WINDS OUT OF THE NE AND
BRINGING MORE STABLE AIR ACROSS THE FOOTHILLS AND PIEDMONT. THE
MOUNTAINS WILL SEE LLVL MOISTURE POOLING DURING THE DAY ON THU...AND
A FEW SHRA/TSTMS ARE EXPECTED TO FIRE IN THE AFTN.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM WEDNESDAY...SHORT RANGE MODELS INDICATE THE A BROAD MID
LEVEL TROF WILL PIVOT SE ALLOWING HEIGHTS TO RISE ACROSS THE MTNS
FRIDAY AFTERNOON. NAM FORECAST SOUNDINGS INDICATE A INVERSION AROUND
H6 ALONG WITH VERY MILD MID LEVEL TEMPERATURES...THE GFS ALSO
INDICATES WARM MID LEVEL TEMPERATURES. BOTH SOLUTIONS SUPPORT
AFTERNOON CAPE VALUES BELOW 1000 J/KG WITH SHALLOW LAYER OF CIN. AT
THE SFC...HIGH PRESSURE WILL REMAIN RIDGED NE TO SE ACROSS THE CWA.
GIVEN THE RISING MID HEIGHTS...SFC RIDGING...AND WEAKLY CAPPED
POTENTIAL INSTABILITY I WILL FAVOR DRY CONDITIONS EAST OF THE MTNS.
HOWEVER...CONDITIONS MAY REMAIN LESS CAPPED ACROSS THE MTNS AND
RIDGETOP CONVECTION COULD OCCUR DURING THE LATE AFTERNOON. I WILL
PAINT SCHC POPS ACROSS THE MTN RIDGES. TEMPERATURES SHOULD RANGE
VERY CLOSE TO NORMAL VALUES...MINS NEAR 60 WITH HIGHS NEAR 80.
ON SATURDAY...MID LEVEL HEIGHT VALUES WILL CONTINUE TO SLOWLY RISE
THROUGH THE AFTERNOON. SFC HIGH PRESSURE WILL REMAIN RIDGE SE ACROSS
THE CWA...SUPPLYING A STEADY LLVL NE WIND. THE NE FLOW RESULTS IN
LOWER LLVL DEWPOINTS AND OVERALL DRIER MOISTURE PROFILE. FORECAST
SOUNDINGS INDICATE LITTLE TO NO INSTABILITY ACROSS THE FORECAST
AREA. THE CHCS FOR DEEP CONVECTION APPEARS MINIMAL AND POPS WILL
REMAIN AROUND 10 PERCENT. TEMPERATURES MAY VERIFY WITHIN A DEGREE
ONE TO TWO DEGREES WARMER THAN FRIDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF NOON WEDNESDAY...A COMPLICATED MID LEVEL PATTERN WILL REMAIN
ACROSS THE SOUTHEAST REGION THROUGH THE EXTENDED PERIOD. IT APPEARS
THAT A BROAD CLOSED LOW WILL REMAIN OVER THE REGION ON SUNDAY...THIS
LOW MAY PHASE WITH AN APPROACHING TROF ON TUESDAY AND WEDNESDAY. THE
TIMING AND PLACEMENT OF THE MAIN FEATURES IS UNCERTAIN. BASED ON
NATIONAL GUIDANCE AND FORECAST CONSISTENCY I WILL ADVERTISE A
GRADUALLY INCREASE IN POPS AND SKY COVER FROM EAST TO WEST SUNDAY
AND MONDAY...THEN KEEP CHCS AND ABUNDANT SKY COVER FOR TUES AND
WEDS. TEMPERATURES SUNDAY THROUGH WEDNESDAY ARE EXPECTED TO RANGE
AROUND NORMAL VALUES.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...TCU ARE DEVELOPING ACROSS THE REGION...THOUGH THE ONLY
SHRA/TSTMS SO FAR HAVE BEEN ABOUT 20 MI SSE OF THE AIRFIELD. A
SHRA/TSTM COULD DEVELOP JUST ABOUT ANY TIME...BUT I/LL CONFINE A
TEMPO GROUP TO THE 20-22 UTC TIME FRAME AS THIS IS WHEN THE HRRR
BRINGS A LITTLE CONVECTION ACROSS THE AIRFIELD. OTRW WILL CARRY VCSH
TIL 00 UTC. FOG AND LOW CLOUDS COULD DEVELOP TONIGHT...BUT PROBABLY
NOT IF IT DOESN/T RAIN IN THE VCNTY. THEREFORE NOTHING HAS BEEN
CARRIED IN THE TAF.
WIND SPEEDS WILL BE LIGHT TODAY. THEY WILL GRADUALLY VEER TO THE SE
BY LATE AFTN...THEN TURN BACK OUT OF THE NE AFTER MIDNIGHT AS A BACK
DOOR COLD FRONT CROSSES THE REGION.
THE KCLT ASOS OBSERVATION IS PERIODICALLY NOT TRANSMITTING. THE ASOS
IS FINE AND I CAN DIAL INTO IT. ATTM I/M NOT SURE IF IT/S AN FFA OR
NWS COMMS ISSUE BUT WE/LL LOOK INTO IT.
ELSEWHERE...HAVE VCSH AT THE REMAINING SITES THROUGH 00 UTC...WITH
THE EXCEPTION OF KHKY WHERE I/VE GONE WITH VCTS FOR THE NEXT FEW
HOURS. NOT EXPECTING MUCH IN THE WAY OF FOG OR LOW CLOUDS TONIGHT.
HOWEVER...A HEAVY SHOWER AT OR IN THE VCNTY OF AN AIRFIELD WOULD
INCREASE THE CHANCES OF BOTH FOG AND LOW CLOUDS LATER TONIGHT. WINDS
WILL GRADUALLY VEER TO THE SE AT MOST SITES THIS AFTN...THEN TURN
BACK OUT OF THE NE LATE TONIGHT AS A BACK DOOR COLD FRONT CROSSES
THE REGION.
OUTLOOK...EXPECT ISOLD LATE DAY SHOWERS AND TSTMS THRU FRI...ESP
MTNS. THEN DRYING OVER THE WEEKEND. MRNG FOG WILL BE PSBL...ESP MTN
VALLEYS AND NEAR LAKES/RIVERS.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...CSH
NEAR TERM...MCAVOY
SHORT TERM...NED
LONG TERM...NED
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
239 PM EDT WED MAY 16 2012
.SYNOPSIS...
A SLOW MOVING UPPER LEVEL AREA OF LOW PRESSURE WILL MOVE EAST ACROSS
THE AREA THROUGH THURSDAY. STRONG HIGH PRESSURE WILL THEN BUILD IN
FROM THE NORTH ON FRIDAY AND REMAIN THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
THE CURRENT WATER VAPOR IMAGERY AND THE LATEST RAP RUN SHOW A WEAK
H5 THROUGH ORIENTED NE TO SW ACROSS THE SRN APPALACHIANS. UPPER
DIVERGENCE ON THE EAST SIDE OF THE TROUGH...WHICH HAS HELPED SPAWN
WIDESPREAD THUNDERSTORM ACTIVITY ALONG THE COAST...IS RESULTING IN
A RAGGED BAROCLINIC LEAF BACK ACROSS THE UPSTATE AND SRN NC
PIEDMONT. THIS HAS CUT DOWN A BIT ON THE INSOLATION ACROSS THE FA
THIS AFTN. EVEN SO...ISOLATED SHRA AND A FEW TSTMS HAVE DEVELOPED
OVER THE REGION...THOUGH COVERAGE HAS BEEN A LITTLE LESS THAN
EXPECTED. THE CONVECTIVE COVERAGE IS EXPECTED TO INCREASE SOME
DURING THE LATE AFTN HOURS...THOUGH NOTHING HIGHER THAN LOW CHANCE
POPS HAS BEEN CARRIED OWING TO THE WEAK SHEAR. WHILE THE STORMS
SHOULD GO INTO THE LATE EVENING HOURS...WE ARE NOT EXPECTING
CONVECTION TO LAST AS LONG AS IT DID LAST NIGHT. THERE IS STILL A
CHANCE THAT ONE OR TWO OF THE STORMS WILL REACH SEVERE
LIMITS...PARTICULARLY ALONG AND SOUTH OF I-85 WHERE THE SHEAR IS A
LITTLE STRONGER...AT LEAST UNTIL AROUND 00 UTC.
THE WEAK TROUGH WILL SETTLE ACROSS THE MIDLANDS LATE TONIGHT AND ON
THURSDAY...PUTTING THE FA UNDER NVA ALOFT. THE TROUGH PASSAGE WILL
BRING A WEAK COLD FRONT THROUGH THE AREA. THE FRONT WILL PUSH IN
FROM THE NE LATE TONIGHT...TURNING THE WINDS OUT OF THE NE AND
BRINGING MORE STABLE AIR ACROSS THE FOOTHILLS AND PIEDMONT. THE
MOUNTAINS WILL SEE LLVL MOISTURE POOLING DURING THE DAY ON THU...AND
A FEW SHRA/TSTMS ARE EXPECTED TO FIRE IN THE AFTN.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM WEDNESDAY...SHORT RANGE MODELS INDICATE THE A BROAD MID
LEVEL TROF WILL PIVOT SE ALLOWING HEIGHTS TO RISE ACROSS THE MTNS
FRIDAY AFTERNOON. NAM FORECAST SOUNDINGS INDICATE A INVERSION AROUND
H6 ALONG WITH VERY MILD MID LEVEL TEMPERATURES...THE GFS ALSO
INDICATES WARM MID LEVEL TEMPERATURES. BOTH SOLUTIONS SUPPORT
AFTERNOON CAPE VALUES BELOW 1000 J/KG WITH SHALLOW LAYER OF CIN. AT
THE SFC...HIGH PRESSURE WILL REMAIN RIDGED NE TO SE ACROSS THE CWA.
GIVEN THE RISING MID HEIGHTS...SFC RIDGING...AND WEAKLY CAPPED
POTENTIAL INSTABILITY I WILL FAVOR DRY CONDITIONS EAST OF THE MTNS.
HOWEVER...CONDITIONS MAY REMAIN LESS CAPPED ACROSS THE MTNS AND
RIDGETOP CONVECTION COULD OCCUR DURING THE LATE AFTERNOON. I WILL
PAINT SCHC POPS ACROSS THE MTN RIDGES. TEMPERATURES SHOULD RANGE
VERY CLOSE TO NORMAL VALUES...MINS NEAR 60 WITH HIGHS NEAR 80.
ON SATURDAY...MID LEVEL HEIGHT VALUES WILL CONTINUE TO SLOWLY RISE
THROUGH THE AFTERNOON. SFC HIGH PRESSURE WILL REMAIN RIDGE SE ACROSS
THE CWA...SUPPLYING A STEADY LLVL NE WIND. THE NE FLOW RESULTS IN
LOWER LLVL DEWPOINTS AND OVERALL DRIER MOISTURE PROFILE. FORECAST
SOUNDINGS INDICATE LITTLE TO NO INSTABILITY ACROSS THE FORECAST
AREA. THE CHCS FOR DEEP CONVECTION APPEARS MINIMAL AND POPS WILL
REMAIN AROUND 10 PERCENT. TEMPERATURES MAY VERIFY WITHIN A DEGREE
ONE TO TWO DEGREES WARMER THAN FRIDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF NOON WEDNESDAY...A COMPLICATED MID LEVEL PATTERN WILL REMAIN
ACROSS THE SOUTHEAST REGION THROUGH THE EXTENDED PERIOD. IT APPEARS
THAT A BROAD CLOSED LOW WILL REMAIN OVER THE REGION ON SUNDAY...THIS
LOW MAY PHASE WITH AN APPROACHING TROF ON TUESDAY AND WEDNESDAY. THE
TIMING AND PLACEMENT OF THE MAIN FEATURES IS UNCERTAIN. BASED ON
NATIONAL GUIDANCE AND FORECAST CONSISTENCY I WILL ADVERTISE A
GRADUALLY INCREASE IN POPS AND SKY COVER FROM EAST TO WEST SUNDAY
AND MONDAY...THEN KEEP CHCS AND ABUNDANT SKY COVER FOR TUES AND
WEDS. TEMPERATURES SUNDAY THROUGH WEDNESDAY ARE EXPECTED TO RANGE
AROUND NORMAL VALUES.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...TCU ARE DEVELOPING ACROSS THE REGION...THOUGH THE ONLY
SHRA/TSTMS SO FAR HAVE BEEN ABOUT 20 MI SSE OF THE AIRFIELD. A
SHRA/TSTM COULD DEVELOP JUST ABOUT ANY TIME...BUT I/LL CONFINE A
TEMPO GROUP TO THE 20-22 UTC TIME FRAME AS THIS IS WHEN THE HRRR
BRINGS A LITTLE CONVECTION ACROSS THE AIRFIELD. OTRW WILL CARRY VCSH
TIL 00 UTC. FOG AND LOW CLOUDS COULD DEVELOP TONIGHT...BUT PROBABLY
NOT IF IT DOESN/T RAIN IN THE VCNTY. THEREFORE NOTHING HAS BEEN
CARRIED IN THE TAF.
WIND SPEEDS WILL BE LIGHT TODAY. THEY WILL GRADUALLY VEER TO THE SE
BY LATE AFTN...THEN TURN BACK OUT OF THE NE AFTER MIDNIGHT AS A BACK
DOOR COLD FRONT CROSSES THE REGION.
THE KCLT ASOS OBSERVATION IS PERIODICALLY NOT TRANSMITTING. THE ASOS
IS FINE AND I CAN DIAL INTO IT. ATTM I/M NOT SURE IF IT/S AN FFA OR
NWS COMMS ISSUE BUT WE/LL LOOK INTO IT.
ELSEWHERE...HAVE VCSH AT THE REMAINING SITES THROUGH 00 UTC...WITH
THE EXCEPTION OF KHKY WHERE I/VE GONE WITH VCTS FOR THE NEXT FEW
HOURS. NOT EXPECTING MUCH IN THE WAY OF FOG OR LOW CLOUDS TONIGHT.
HOWEVER...A HEAVY SHOWER AT OR IN THE VCNTY OF AN AIRFIELD WOULD
INCREASE THE CHANCES OF BOTH FOG AND LOW CLOUDS LATER TONIGHT. WINDS
WILL GRADUALLY VEER TO THE SE AT MOST SITES THIS AFTN...THEN TURN
BACK OUT OF THE NE LATE TONIGHT AS A BACK DOOR COLD FRONT CROSSES
THE REGION.
OUTLOOK...EXPECT ISOLD LATE DAY SHOWERS AND TSTMS THRU FRI...ESP
MTNS. THEN DRYING OVER THE WEEKEND. MRNG FOG WILL BE PSBL...ESP MTN
VALLEYS AND NEAR LAKES/RIVERS.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...CSH
NEAR TERM...MCAVOY
SHORT TERM...NED
LONG TERM...NED
AVIATION...MCAVOY
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
752 PM MDT THU MAY 17 2012
.UPDATE...
PERTURBED SW FLOW CONTINUES TO SUPPORT AN ARRAY OF IMPULSES OVER
THE NORTHERN PLAINS AND CENTRAL ROCKIES...WITH EACH DISTURBANCE
SUPPORTING ISOLD/SCT SHRA/TS. STRONGEST LOCAL MID LEVEL FORCING
SEEMS TO BE ASSOCIATED WITH THE A COMPLEX OF TS OVER NORTHERN
CAMPBELL COUNTY...WHICH IS ON TRACK TO SKIRT MUCH OF THE FAR NW
THIS EVENING. HIGH LCL/S WITH STEEP LL/MID LAPSE RATES LOOKS TO
SUPPORT A STRONG GUSTY WIND AND SMALL HAIL THREAT WITH THE
STRONGEST CELLS. ADJUSTED POPS TO ACCOUNT FOR ONGOING
ACTIVITY/TRENDS...WITH EXPANSION OF SLIGHT CHANCE POPS TO COVER
THE FAR SE.
&&
.PREV DISCUSSION... /ISSUED 529 PM MDT THU MAY 17 2012/
AVIATION.../00Z TAFS/
A SFC TROUGH WILL REMAIN IN PLACE OVER THE REGION...WITH LIGHT AND
VARIABLE WINDS ALONG AND NEAR THE SFC TROUGH...INCLUDING THE
TERMINALS. ISOLD SHRA/TS WILL BE POSSIBLE THROUGH EVENING...WITH
SMALL HAIL AND GUSTY WINDS POSSIBLE NEAR THUNDERSTORMS. A STRONGER
UPPER LEVEL IMPULSE WILL TRAVERSE THE NORTHERN PLAINS ON
FRIDAY...FORCING DEEPENING SFC LOW PRESSURE WITH INCREASING
CHANCES FOR SHRA/TS IN THE AFTERNOON. WINDS WILL STRENGTHEN OUT OF
THE NW BEHIND THE SFC TROUGH...WITH GUSTY SSW WINDS TO THE EAST
OVER SOUTH CENTRAL SD.
PREV DISCUSSION... /ISSUED 257 PM MDT THU MAY 17 2012/
DISCUSSION...
A BROAD...FLAT LONG WAVE TROF EXTENDS FROM COAST TO COAST THIS
MORNING WITH A SHORT WAVE TROF OVER CO. MODELS ARE IN GOOD
AGREEMENT IN BRINGING A STRONGER TROF INLAND FROM THE PAC TO A
POSITION JUST W OF OUR CWA BY 12Z SAT. AIR MASS OVER THE AREA IS
CHARACTERIZED BY VERY STEEP LOW LEVEL LAPSE RATES AND LIMITED
MOISTURE. A FEW TSTMS HAVE DVLPD THIS AFTN MAINLY OVER THE HIER
TERRAIN OF THE BLACK HILLS WITH A FEW SHOWERS OVER NE WY AND NW SD.
GIVEN THE DRY LOW LVLS AND STEEP BELOW CLOUD LAPSE RATES THESE
STORMS COULD PRODUCE STRONG...GUSTY SFC WINDS DURING THE EVNG
HOURS. THE HRRR MODEL SHOWS A N TO S LINE OF TSTMS FROM NW SD
THROUGH RAP AND S WARD AT 03Z.
WITH THE APPROACH OF THE SECOND TROF FRIDAY AFTN THERE IS THE
CHANCE FOR MORE WIDESPREAD AND VIGOROUS CONVECTION. MOISTURE WILL
REAMIN LIMITED...BUT SFC BASED CAPE FCSTS OF ABT 1000 J/KG BY THE
18Z NAM LOOK REASONABLE. SFC TO 6KM SHEAR IS FCST TO RANGE FROM
ABOUT 40KTS OVER NW SD TO 20 KTS SE PORTIONS OF OUR CWA. A
BOUNDARY FROM TONIGHTS CONVECTION MAY PROVIDE SOME FOCUS AND WILL
BE REINFORCED BY INCREASING NRLY FLOW OVER WRN AND NWRN PORTIONS
OF THE CWA. NAM FCSTS THIS BOUNDARY TO BE FROM S OF RAP TO ROUGHLY
PHP AT 21Z FRIDAY.
WITH THE APPROACHING TROF...500 MB Q VECTOR CONVERGENCE REMAINS
OVER THE AREA FRIDAY NIGHT INTO SATURDAY EVG. POST FRONTAL SHOWERS
AND TSTMS SHOULD CONTINUE OVER MUCH THE AREA...GRADUALLY ENDING
FROM THE NW.
EXTENDED...AN UPPER RIDGE WILL BUILD INTO THE REGION EARLY NEXT WEEK
BRINGING DRY CONDITIONS. TEMPERATURES WILL BE NEAR AVERAGE
SUNDAY...WITH A GRADUAL WARMING TREND TO START THE WORK WEEK. MODELS
CONTINUE TO SHOW A SLOW MOVING UPPER TROUGH PUSHING INTO THE REGION
LATE TUESDAY INTO WEDNESDAY AND THURSDAY. MODELS CONSISTENCY IS
STILL LACKING (ECMWF CLOSES THE SYSTEM OFF WHILE GEM/GFS KEEP IT
OPEN)...BUT THIS COULD BRING A ROUND OF SHOWERS SHOWERS AND
THUNDERSTORMS TO THE AREA.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...BARBER
LONG TERM...77
AVIATION...JC
UPDATE...JC
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
529 PM MDT THU MAY 17 2012
.AVIATION.../00Z TAFS/
A SFC TROUGH WILL REMAIN IN PLACE OVER THE REGION...WITH LIGHT AND
VARIABLE WINDS ALONG AND NEAR THE SFC TROUGH...INCLUDING THE
TERMINALS. ISOLD SHRA/TS WILL BE POSSIBLE THROUGH EVENING...WITH
SMALL HAIL AND GUSTY WINDS POSSIBLE NEAR THUNDERSTORMS. A STRONGER
UPPER LEVEL IMPULSE WILL TRAVERSE THE NORTHERN PLAINS ON
FRIDAY...FORCING DEEPENING SFC LOW PRESSURE WITH INCREASING
CHANCES FOR SHRA/TS IN THE AFTERNOON. WINDS WILL STRENGTHEN OUT OF
THE NW BEHIND THE SFC TROUGH...WITH GUSTY SSW WINDS TO THE EAST
OVER SOUTH CENTRAL SD.
&&
.PREV DISCUSSION... /ISSUED 257 PM MDT THU MAY 17 2012/
DISCUSSION...
A BROAD...FLAT LONG WAVE TROF EXTENDS FROM COAST TO COAST THIS
MORNING WITH A SHORT WAVE TROF OVER CO. MODELS ARE IN GOOD
AGREEMENT IN BRINGING A STRONGER TROF INLAND FROM THE PAC TO A
POSITION JUST W OF OUR CWA BY 12Z SAT. AIR MASS OVER THE AREA IS
CHARACTERIZED BY VERY STEEP LOW LEVEL LAPSE RATES AND LIMITED
MOISTURE. A FEW TSTMS HAVE DVLPD THIS AFTN MAINLY OVER THE HIER
TERRAIN OF THE BLACK HILLS WITH A FEW SHOWERS OVER NE WY AND NW SD.
GIVEN THE DRY LOW LVLS AND STEEP BELOW CLOUD LAPSE RATES THESE
STORMS COULD PRODUCE STRONG...GUSTY SFC WINDS DURING THE EVNG
HOURS. THE HRRR MODEL SHOWS A N TO S LINE OF TSTMS FROM NW SD
THROUGH RAP AND S WARD AT 03Z.
WITH THE APPROACH OF THE SECOND TROF FRIDAY AFTN THERE IS THE
CHANCE FOR MORE WIDESPREAD AND VIGOROUS CONVECTION. MOISTURE WILL
REAMIN LIMITED...BUT SFC BASED CAPE FCSTS OF ABT 1000 J/KG BY THE
18Z NAM LOOK REASONABLE. SFC TO 6KM SHEAR IS FCST TO RANGE FROM
ABOUT 40KTS OVER NW SD TO 20 KTS SE PORTIONS OF OUR CWA. A
BOUNDARY FROM TONIGHTS CONVECTION MAY PROVIDE SOME FOCUS AND WILL
BE REINFORCED BY INCREASING NRLY FLOW OVER WRN AND NWRN PORTIONS
OF THE CWA. NAM FCSTS THIS BOUNDARY TO BE FROM S OF RAP TO ROUGHLY
PHP AT 21Z FRIDAY.
WITH THE APPROACHING TROF...500 MB Q VECTOR CONVERGENCE REMAINS
OVER THE AREA FRIDAY NIGHT INTO SATURDAY EVG. POST FRONTAL SHOWERS
AND TSTMS SHOULD CONTINUE OVER MUCH THE AREA...GRADUALLY ENDING
FROM THE NW.
EXTENDED...AN UPPER RIDGE WILL BUILD INTO THE REGION EARLY NEXT WEEK
BRINGING DRY CONDITIONS. TEMPERATURES WILL BE NEAR AVERAGE
SUNDAY...WITH A GRADUAL WARMING TREND TO START THE WORK WEEK. MODELS
CONTINUE TO SHOW A SLOW MOVING UPPER TROUGH PUSHING INTO THE REGION
LATE TUESDAY INTO WEDNESDAY AND THURSDAY. MODELS CONSISTENCY IS
STILL LACKING (ECMWF CLOSES THE SYSTEM OFF WHILE GEM/GFS KEEP IT
OPEN)...BUT THIS COULD BRING A ROUND OF SHOWERS SHOWERS AND
THUNDERSTORMS TO THE AREA.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...BARBER
LONG TERM...77
AVIATION...JC
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1228 PM CDT WED MAY 16 2012
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
THE VAST MAJORITY OF THE TODAY PERIOD FORECAST IS IN FINE SHAPE.
DID BEEF UP WIND SPEEDS A FEW MORE KNOTS ACROSS THE MISSOURI RIVER
VALLEY AND ISSUE A WIND ADVISORY VALID UNTIL 7 PM CDT FOR THAT
PORTION OF THE CWA...PER BUFKIT MOMENTUM TRANSFER TOOL AND 06Z/12Z
0.5KM FORECAST WIND SPEEDS /30 TO 35 KNOTS/ TODAY. THAT AND A FEW
OBSERVATIONS WEST AND NORTHWEST OF THE CWA HAD ALREADY CHIMED IN
WITH MARGINAL TO LOW END ADVISORY CRITERIA AT 9 AM CDT AND 10 AM
CDT THIS MORNING.
ALSO...BASED OFF THE LATEST AVAILABLE GFS/NAM AND RAP LOW LEVEL
THERMAL PROGS...DID BUMP UP TEMPERATURES FROM BROWN AND SPINK
COUNTIES WESTWARD APPX 2 TO 5 DEGREES. UPDATES ARE OUT.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH FRIDAY
WINDS TODAY...AND PCPN CHANCES TONIGHT ARE THE MAIN FORECAST CHALLENGES.
AN AREA OF HIGH PRESSURE OVER THE EASTERN DAKOTAS THIS MORNING
WILL BE REPLACED BY A LOW PRESSURE SYSTEM CURRENTLY OVER THE
NORTHERN HIGH PLAINS. WITH A STRENGTHENING PRESSURE GRADIENT
ACROSS THE WESTERN DAKOTAS TODAY WINDS MAY APPROACH ADVISORY
CRITERIA. GFS LAMP GUIDANCE IS SUGGESTING SUSTAINED WINDS ALONG
THE MISSOURI RIVER COULD REACH 27 KNOTS WITH WIND GUSTS AROUND 35
KNOTS...OR SUB ADVISORY. WILL GO HEADLINE FREE FOR NOW AND LET THE
DAY SHIFT ISSUE AN ADVISORY AS NEEDED.
LATER TONIGHT...A 50 TO 60 KNOT SW ORIENTATE LLJ DEVELOPS OVER
EASTERN SD AND WESTERN MN. DECENT UVM AND MOISTURE ADVECTION ALONG
THE NOSE OF THE LLJ MAY RESULT IN SCT SHOWERS AND THUNDERSTORMS
FOR THE NE CWA AFTER 6Z. WITH GOOD MODEL TO MODEL CONTINUITY WITH
THIS FEATURE...HAVE DECIDED TO INCREASE POPS SOME.
ANOTHER LLJ WILL DEVELOPS THURSDAY NIGHT ACROSS NORTHERN MN WITH
THIS CWA LIKELY SEEING DRY CONDITIONS. THUS HAVE REMOVED THE
PREVIOUS FORECAST POPS.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
THE MODELS ALL SHOW A COLD FRONT MAKING ITS WAY ACROSS THE CWA
LATE FRIDAY NIGHT THROUGH SATURDAY EVENING. THEY ALL HAVE SOME
DIFFERENCES IN THE SPEED OF THE FRONT ALONG WITH THE QPF OCCURRING
IN ASSOCIATION WITH IT. THEY WERE DIFFERENT MAINLY AS A RESULT OF
THE STRENGTH AND TIMING OF THE SURFACE LOW PRESSURE AREA LIFTING
NORTHEAST ALONG THE FRONT. NONETHELESS...IT DOES LOOK LIKE A
STRONG BOUNDARY WITH PLENTY OF INSTABILITY ALONG AND BEHIND IT.
ALREADY HAD IN DECENT CHANCE POPS IN THE GRIDS WITH THE FRONT FOR
FRIDAY NIGHT THROUGH SATURDAY NIGHT. COOLER AND DRIER HIGH
PRESSURE AIR WILL PUSH IN FOR SUNDAY WITH HIGHS AROUND 70 FOR THE
AFTERNOON. THE SURFACE HIGH PRESSURE AREA WILL PUSH EAST MONDAY
AND TUESDAY WITH WARMER AIR RETURNING ON THE BACKSIDE. SOUTH WINDS
WILL ALSO PICK UP INTO MONDAY BRINGING IN THE WARMER AIR. MONDAY
WILL BE IN THE 70S ACROSS THE CWA WITH MAINLY 80S ON TUESDAY. IT
DOES LOOK LIKE MONDAY AND TUESDAY WILL BE DRY.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL PREVAIL THROUGH TODAY AND TONIGHT AT ALL
TERMINALS. SOUTH TO SOUTHEAST WINDS WILL INCREASE FROM WEST TO
EAST THROUGH THE AFTERNOON. WINDS WILL BE STRONGEST OVER THE KMBG AND KPIR
TERMINALS WHERE SPEEDS WILL RANGE FROM 25 TO 35 KNOTS BY 21Z. THE
WINDS WILL FALL OFF EARLY THIS EVENING INTO THE 15 TO 20 KNOT
RANGE AT ALL TERMINALS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR BUFFALO-
CAMPBELL-CORSON-DEWEY-HUGHES-HYDE-JONES-LYMAN-POTTER-
STANLEY-SULLY-WALWORTH.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...DORN
LONG TERM...MOHR
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1127 AM CDT WED MAY 16 2012
.UPDATE...
THE VAST MAJORITY OF THE TODAY PERIOD FORECAST IS IN FINE SHAPE.
DID BEEF UP WIND SPEEDS A FEW MORE KNOTS ACROSS THE MISSOURI RIVER
VALLEY AND ISSUE A WIND ADVISORY VALID UNTIL 7 PM CDT FOR THAT
PORTION OF THE CWA...PER BUFKIT MOMENTUM TRANSFER TOOL AND 06Z/12Z
0.5KM FORECAST WIND SPEEDS /30 TO 35 KNOTS/ TODAY. THAT AND A FEW
OBSERVATIONS WEST AND NORTHWEST OF THE CWA HAD ALREADY CHIMED IN
WITH MARGINAL TO LOW END ADVISORY CRITERIA AT 9 AM CDT AND 10 AM
CDT THIS MORNING.
ALSO...BASED OFF THE LATEST AVAILABLE GFS/NAM AND RAP LOW LEVEL
THERMAL PROGS...DID BUMP UP TEMPERATURES FROM BROWN AND SPINK
COUNTIES WESTWARD APPX 2 TO 5 DEGREES. UPDATES ARE OUT.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH FRIDAY
WINDS TODAY...AND PCPN CHANCES TONIGHT ARE THE MAIN FORECAST CHALLENGES.
AN AREA OF HIGH PRESSURE OVER THE EASTERN DAKOTAS THIS MORNING
WILL BE REPLACED BY A LOW PRESSURE SYSTEM CURRENTLY OVER THE
NORTHERN HIGH PLAINS. WITH A STRENGTHENING PRESSURE GRADIENT
ACROSS THE WESTERN DAKOTAS TODAY WINDS MAY APPROACH ADVISORY
CRITERIA. GFS LAMP GUIDANCE IS SUGGESTING SUSTAINED WINDS ALONG
THE MISSOURI RIVER COULD REACH 27 KNOTS WITH WIND GUSTS AROUND 35
KNOTS...OR SUB ADVISORY. WILL GO HEADLINE FREE FOR NOW AND LET THE
DAY SHIFT ISSUE AN ADVISORY AS NEEDED.
LATER TONIGHT...A 50 TO 60 KNOT SW ORIENTATE LLJ DEVELOPS OVER
EASTERN SD AND WESTERN MN. DECENT UVM AND MOISTURE ADVECTION ALONG
THE NOSE OF THE LLJ MAY RESULT IN SCT SHOWERS AND THUNDERSTORMS
FOR THE NE CWA AFTER 6Z. WITH GOOD MODEL TO MODEL CONTINUITY WITH
THIS FEATURE...HAVE DECIDED TO INCREASE POPS SOME.
ANOTHER LLJ WILL DEVELOPS THURSDAY NIGHT ACROSS NORTHERN MN WITH
THIS CWA LIKELY SEEING DRY CONDITIONS. THUS HAVE REMOVED THE
PREVIOUS FORECAST POPS.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
THE MODELS ALL SHOW A COLD FRONT MAKING ITS WAY ACROSS THE CWA
LATE FRIDAY NIGHT THROUGH SATURDAY EVENING. THEY ALL HAVE SOME
DIFFERENCES IN THE SPEED OF THE FRONT ALONG WITH THE QPF OCCURRING
IN ASSOCIATION WITH IT. THEY WERE DIFFERENT MAINLY AS A RESULT OF
THE STRENGTH AND TIMING OF THE SURFACE LOW PRESSURE AREA LIFTING
NORTHEAST ALONG THE FRONT. NONETHELESS...IT DOES LOOK LIKE A
STRONG BOUNDARY WITH PLENTY OF INSTABILITY ALONG AND BEHIND IT.
ALREADY HAD IN DECENT CHANCE POPS IN THE GRIDS WITH THE FRONT FOR
FRIDAY NIGHT THROUGH SATURDAY NIGHT. COOLER AND DRIER HIGH
PRESSURE AIR WILL PUSH IN FOR SUNDAY WITH HIGHS AROUND 70 FOR THE
AFTERNOON. THE SURFACE HIGH PRESSURE AREA WILL PUSH EAST MONDAY
AND TUESDAY WITH WARMER AIR RETURNING ON THE BACKSIDE. SOUTH WINDS
WILL ALSO PICK UP INTO MONDAY BRINGING IN THE WARMER AIR. MONDAY
WILL BE IN THE 70S ACROSS THE CWA WITH MAINLY 80S ON TUESDAY. IT
DOES LOOK LIKE MONDAY AND TUESDAY WILL BE DRY.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL PREVAIL THROUGH TODAY AND TONIGHT AT ALL
TERMINALS. SOUTH TO SOUTHEAST WINDS WILL BECOME QUITE GUSTY BY MID
TO LATE MORNING AND WILL INCREASE THROUGH THE DAY. WINDS WILL BE
STRONGEST OVER THE KMBG AND KPIR TERMINALS WHERE SPEEDS WILL RANGE
FROM 25 TO 35 KNOTS BY AFTERNOON. THE WINDS WILL FALL OFF EARLY
THIS EVENING INTO THE 15 TO 20 KNOT RANGE AT ALL TERMINALS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR BUFFALO-
CAMPBELL-CORSON-DEWEY-HUGHES-HYDE-JONES-LYMAN-POTTER-
STANLEY-SULLY-WALWORTH.
MN...NONE.
&&
$$
UPDATE...DORN
SHORT TERM...SD
LONG TERM...MOHR
AVIATION...MOHR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS BLACKSBURG VA
200 PM EDT WED MAY 16 2012
.SYNOPSIS...
THE PESKY WEAK STATIONARY BOUNDARY...WHICH HAS BEEN THE FOCUS FOR
HEAVY RAINFALL THE PAST FEW DAYS...WILL FINALLY DRIFT EAST TONIGHT
THROUGH WEDNESDAY. HIGH PRESSURE WILL DRIFT ACROSS THE UPPER OHIO
VALLEY ON THURSDAY...THEN MOVE OFF THE NEW ENGLAND COAST BY
SUNDAY...IN RESPONSE TO A STRENGTHENING UPPER RIDGE.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 1035 PM EDT TUESDAY...
PLANNING TO GO AHEAD AND DROP THE FLASH FLOOD WATCH OVERNIGHT
GIVEN LACK OF COVERAGE AND NOCTURNAL COOLING. HOWEVER SOME
GUIDANCE INCLUDING THE HRRR STILL WANTS TO REDEVELOP HEAVIER SHRA
ESPCLY SOUTH AFTER MIDNIGHT ALONG WHERE THE CURRENT THETA-E GRADIENT
EXISTS. THINK THIS IS OVERDONE AT THIS POINT BUT APPEARS SOME SHRA
WILL FILL BACK IN ALONG THE FOOTHILLS GIVEN LEFTOVER INSTABILITY BUT
LIKELY TOO ISOLATED TO KEEP A BROAD WATCH UP AT THIS POINT. THUS
WILL ONLY KEEP IN HIGH CHANCE POPS SOUTH/EAST OVERNIGHT WITH MENTION
OF BRIEF HEAVY RAIN IN THE HWO. DRIER AIR SEEPING INTO THE WEST
SHOULD KEEP THINGS DRY FROM THE NEW RIVER VALLEY NORTH AND WEST
OVERNIGHT SO TRIMMED POPS A BIT MORE THERE WITH ADDITION OF MORE
DENSE FOG IN SPOTS ESPCLY WHERE ADDED HEAVY RAINFALL OCCURRED THIS
EVENING. MAY NEED A DENSE FOG ADVISORY BY MORNING AS WELL MAINLY
SOUTH AND EAST WHERE DEWPOINTS ARE HIGHER AND DRIER AIR WONT MAKE IT
UNTIL EARLY WED AT BEST. NUDGED DOWN LOW TEMPS A FEW DEGREES WEST
OTRW STAYED CLOSE TO THE PREVIOUS FORECAST.
AS OF 8 PM EDT TUESDAY...
SENT A QUICK UPDATE TO LOWER POPS SIGNIFICANTLY ACROSS THE AREA
GIVEN DIMINISHING ECHOES ALONG THE BLUE RIDGE AND ONLY SCTD STORMS
REMAINING IN THE PIEDMONT AND WEST OF THE NC NRN MOUNTAINS.
APPEARS A BIT LOWER THETA-E AIR ACROSS THE FAR WEST HAS WEAKENED
THE ONGOING CONVERGENCE...WITH OUTFLOW DRIVEN STORMS ACROSS THE
EAST. HOWEVER INSTABILITY REMAINS PRETTY HIGH ESPCLY SOUTH-SE SO
LEAVING IN HIGH CHANCE FOR A FEW MORE HOURS BEFORE LIKELY SEEING A
MORE DIURNALLY DRIVEN REDUCTION IN COVERAGE THIS EVENING PER
WEAKER SUPPORT AND MORE WEST/SW FLOW ALOFT ATTM. APPEARS MOST
AREAS MAY BE PRECIP FREE AROUND MIDNIGHT IF NOT SOONER SIMILAR TO
TO PREVIOUS THINKING SO KEPT IN A SMALL POP MAINLY SE THIRD
OVERNIGHT. MAY ALSO BE ABLE TO DROP THE WATCH EARLY PENDING
COVERAGE OVER THE NEXT COUPLE OF HOURS.
AS OF 249 PM EDT TUESDAY...
SIMILAR TO YESTERDAY AT THIS TIME...SHOWERS AND STORMS HAVE BEEN
SLOW TO DEVELOP THANKS TO CLOUD COVER. BUT WOULDN`T BE SURPRISED
IF RAPID DEVELOPMENT AGAIN OCCURS BY LATE AFTERNOON...WITH OUTFLOW
BOUNDARIES ONLY HELPING MORE STORMS TO POP UP. SPC MESOANALYSIS
CONTINUES TO SHOW INCREASING CAPE/INSTABILITY DESPITE THE CLOUD
COVER. THUNDERSTORMS ALREADY BEGINNING TO LINE UP FROM SW TO NE IN
GRAYSON COUNTY...AND AS THIS CLUSTER MOVES NE MAY BE THE BEGINNING
OF MORE ORGANIZATION MOVING TOWARDS FLOYD AND HARD HIT FRANKLIN
COUNTY. BY DINNERTIME...LOCAL MODELS HAVE AN ORGANIZED TRAINING LINE
RIGHT ALONG THE BLUE RIDGE...AND THE CELLS MAY STAY ANCHORED TO
THE MOUNTAINS CONSIDERING MEAGER LLVL WIND FIELDS AND NIL
SHEAR...BELOW 10 M/S...EVEN THROUGH 3KM AGL. THUS...THE FLASH FLOOD
WATCH STANDS. DESPITE THE RATHER WET SOUNDING...ENOUGH MIDLEVEL
DRY AIR EXISTS SUCH THAT 500 J/KG OF DCAPE IS PRESENT...SO SOME
GUSTY WINDS AND SCATTERED SVR STORMS ARE ALSO POSSIBLE...PER SPC
SLT RISK IN OUR AREA. OF COURSE VERY LOW FFG ESPECIALLY IN HARD
HIT FRANKLIN AND ROCKBRIDGE...UNDER AN INCH AN HOUR...SO IT WILL
NOT TAKE MUCH FOR MORE WATER PROBLEMS CONSIDERING PWATS 120% OF
NORMAL. AGAIN COULD BE LOOKING AT A CRITICAL SITUATION ACROSS THE
HARD HIT AREAS CONSIDERING THESE STORMS HAVE THE POTENTIAL TO PUT
DOWN AN INCH OR TWO IN 30 MINUTES. THE FLASH FLOOD WATCH MAY HAVE
TO BE EXPANDED TOO DEPENDING UPON DEVELOPMENT. LOOKING FOR
FOG WHICH AGAIN COULD BE DENSE AFTER MIDNIGHT...AS STORMS FINALLY
DIE.
WITH THE WEAK BOUNDARY FINALLY MAKING SOME EASTWARD PROGRESS
WEDNESDAY...LLVL WINDS WILL BE DEEPER AND STRONGER FROM A
DOWNSLOPING DIRECTION AS FAR EAST AS THE BLUE RIDGE. ALTHOUGH THIS
USUALLY CREATES ENOUGH SUBSIDENCE TO PRECLUDE PRECIP...CAN`T RULE
OUT AN ISOLATED THUNDERSTORMS OUTSIDE OF SE WEST VA CONSIDERING
SOME INSTABILITY STILL IN PLACE AND DEVELOPING WEAK LEE TROUGH.
LIMITING FACTOR THOUGH WILL BE MIDLEVEL MOISTURE...AS H7 RH GETS
PRETTY DRY BY 18Z/2P WEDNESDAY NEW RIVER VALLEY AND WEST. BEST
OPPORTUNITY FOR SCATTERED STORMS WILL BE ALONG THE SOUTHSIDE
WEDNESDAY...WHERE SOME STORMS AGAIN COULD BE SEVERE...WITH
SOMEWHAT BETTER SHEAR AND UPPER LEVEL WINDS AS A FEW DISTURBANCES
RIDE NE TOWARDS RDU. DRIER AIR AND DOWNSLOPE WARMING...WITH LESS
CLOUDS COMBINED WITH H85 TEMPS AROUND +14C...MEAN THE WARMER SPOTS
SHOULD CROSS 80F SO MAX T WAS RAISED BY SEVERAL DEGREES TO PUT IT
MORE IN LINE WITH MAV/MET MOS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 300 PM EDT TUESDAY...
KEEPING JUST A SLIGHT CHANCE OF SHOWERS/TSRA IN THE FAR SOUTHEAST
WED EVENING AS THE FRONT DEPARTS. WILL SEE CLEARING SKIES WITH WINDS
OUT OF NW AND LIGHT. NOT OUT OF THE QUESTION TO SEE SOME FOG LATE
WED NIGHT IN THE DEEPER VALLEYS.
AMPLIFICATION OF THE 5H TROUGH TAKES PLACE OVER THE SOUTHEAST WITH
MODELS CLOSING OFF A LOW OFF THE COAST BY FRIDAY WITH SHORTWAVE
RIDGING PUSHING INTO THE OHIO VALLEY. NUDGE IN COOLER AIR/DEWPOINTS
WILL BE OCCURRING BEHIND THE FRONT THURSDAY WITH THE SFC HIGH
SHIFTING EWD INTO THE MID ATLANTIC. MOISTURE STAYS MAINLY CONFINED
INTO THE SOUTHEAST THURSDAY BUT ENOUGH EAST FLOW TO ALLOW FOR SOME
ISOLATED MOUNTAIN CONVECTION IN NORTH CAROLINA DURING THE
AFTERNOON/EARLY EVENING.
THU NIGHT-FRIDAY WILL BE MAINLY DRY WITH THE HIGH PRESSURE WEDGING
SW INTO THE MTNS...BUT AGAIN HIGHER MOISTURE STAYS ACROSS THE
SOUTHEAST AND COULD DEFINITELY SHIFT NWD ALONG THE SRN APPALACHIANS
LEADING TO OROGRAPHICALLY INDUCED SHRA/TSRA DURING THE AFTERNOON
FRIDAY. CHANCES STAY SMALL THOUGH.
WENT WITH TEMPS CLOSER TO THE LOCAL MOS THIS PERIOD AS IT HAS
PERFORMED A BIT BETTER THAN THE MET/MAV OVERALL. SHOULD SEE LOWS IN
THE UPPER 40S IN THE MOUNTAINS WED NIGHT TO MID 50S EAST. IT STAYS
SEASONAL INTO FRIDAY WITH HIGHS IN THE 70S AND LOWS IN THE UPPER 40S
TO LOWER 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 1255 PM EDT TUESDAY...
WEEKEND IS LOOKING MAINLY DRY WITH AT OR ABOVE NORMAL TEMPS AS SFC
HIGH WEDGES SOUTHWEST ACROSS THE REGION. CLOUD COVER LOOKS SPARSE
OVERALL...BUT THERE COULD BE STRATUS FORMATION FRI NIGHT WITH SE-E
FLOW ALONG THE BLUE RIDGE. STILL CONFIDENCE NOT HIGH ENOUGH YET TO
GO WITH A BKN-OVC SKY AS HIGH PRESSURE SHOULD CLOSE ENOUGH TO KEEP
THE FLOW LIGHT.
MAKING ADJUSTMENTS HEADING INTO EARLY NEXT WEEK...AS MOST MODELS
AGREE THAT THE UPPER LOW OFF THE SOUTHEAST COAST RETROGRADES TOWARD
FLORIDA BY MONDAY...AND NORTHERN STREAM SHORTWAVE MOVES ACROSS THE
GREAT LAKES. A FRONTAL BOUNDARY APPROACHES THE CENTRAL APPALACHIANS
TUESDAY. MONDAY...MODELS INDICATE ENOUGH ATLANTIC MOISTURE MAY FEED
INTO THE CAROLINAS AND SURGE NWD TOWARD VIRGINIA...THAT WENT WITH
SLIGHT CHANCE OF SHOWERS OR STORMS. BETTER CHANCE ARRIVES BUT STILL
30 POPS TUESDAY WITH SHORTWAVE APPROACHING WITH THE FRONT.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
AS OF 200 PM EDT WEDNESDAY...
CWA IN BETWEEN MOIST/UNSTABLE AIR MASS TO THE SE AND MORE
STABLE...YET MOIST LOW-LEVEL AIR MASS TO THE NW. BIGGEST PROBLEM FOR
THE MAJORITY OF THE CWA THIS MORNING WILL BE FOG. EXPECT IFR-LIFR
BR/FG AT MANY LOCATIONS ACROSS THE NEW RIVER VALLEY AND WV AREAS
OVERNIGHT. LESS THREAT TOWARD THE PIEDMONT BECAUSE OF EXTENSIVE
HIGH/MID CLOUDS STREAMING NE FROM CONVECTION ACROSS SC/NC.
HOWEVER...STILL EXPECT MVFR BR IN THESE AREAS FOR SEVERAL HOURS
LATER THROUGH EARLY MORNING. FOG SHOULD LIFT ALL AREAS BY 14Z...WITH
GENERALLY SCT-BKN MVFR-LVFR CIGS THROUGH THE MORNING/AFTERNOON
HOURS. FOG POTENTIAL APPEARS TO BE LESS THU MORNING GIVEN SLIGHTLY
DRIER NW FLOW. DEEPER MOISTURE/LIFTING FOCUS FINALLY SHIFTS SE OF
THE CWA BY AFTERNOON...WITH THREAT FOR CONVECTION TODAY GENERALLY
LIMITED TO THE PIEDMONT...HENCE DAN. ON THE OTHER HAND...A WEAK
FRONTAL SYSTEM WILL MOVE INTO WV FROM THE NW DURING THE AFTERNOON.
OROGRAPHIC LIFT/UPSLOPE SHOULD PROVIDE ENOUGH SUPPORT FOR BKN MID
CLOUDS AND AT LEAST ISOLD SHRA...SO HAVE INCLUDED VCSH BLF-LWB LATE
AFTERNOON/EARLY EVENING. DO NOT FEEL THERE WILL BE TSRA WITH
THIS...BUT WILL MONITOR THE THREAT FOR SUCH WITH LATER UPDATES.
WINDS LIGHT/VARIABLE ACROSS THE PIEDMONT TODAY...GENERALLY IN A COL
REGION. WV/NEW RIVER VALLEY TAF SITES SHOULD SEE A LIGHT NW
FLOW...5-7KTS...WITH POTENTIALLY 10KTS ROA DURING AFTERNOON MIXING.
AS OF 700 PM EDT TUESDAY...
SOME IFR CIG/VIS AGAIN MAY OCCUR AT KLWB AS HIGH PRESSURE SLIDES
ACROSS THE OHIO VALLEY WEDNESDAY NIGHT. HIGH PRESSURE ACROSS THE
OHIO VALLEY AND LOW PRESSURE OFF THE COAST WILL COMBINE TO PRODUCE
DEEP BUT RATHER LIGHT EASTERLY UPSLOPE FLOW...WHICH MAY WORK ON
LEFT OVER INSTABILITY KLWB/KBLF ON THURSDAY FOR SOME STORMS. HIGH
PRESSURE STRENGTHENS AND MOVES OFF THE NEW ENGLAND COAST THIS
WEEKEND TAKING ON A WEDGE POSITION...HOWEVER ATTM THIS WEDGE
APPEARS TO BE DRY...ALTHOUGH MORE MOISTURE THAN THE MODELS ARE
FORECASTING COULD PRODUCE SOME MVFR CIGS AT TIMES DURING THE
NIGHTS INTO THE WEEKEND.
&&
.HYDROLOGY...
SOME ADDED SHOWERS MAY OCCUR ALONG THE SOUTHERN BLUE RIDGE AND
FOOTHILLS OVERNIGHT BUT ARE NOT EXPECTED TO BE ENOUGH TO CAUSE
WIDESPREAD FLOODING. THUS HAVE DROPPED THE GOING FLASH FLOOD WATCH
ACROSS THE AREA FOR NOW.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KM/RAB
NEAR TERM...JH/KM
SHORT TERM...NF
LONG TERM...WP
AVIATION...RAH/WP
HYDROLOGY...JH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
647 PM CDT THU MAY 17 2012
.SHORT TERM...
647 PM CDT THU MAY 17 2012
WINDS HAVE DIMINISHED BELOW ADVISORY CRITERIA. THUS WILL ALLOW
WIND ADVISORY TO EXPIRE AT 7 PM.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
319 PM CDT THU MAY 17 2012
17.12 MEDIUM RANGE FORECAST MODELS CONTINUE TO OFFER SLIGHTLY
DIFFERING SOLUTIONS ON EXACTLY WHAT TIME THE COLD FRONT MOVES
THROUGH THE FORECAST AREA SUNDAY NIGHT. THE ECMWF REMAINS THE
SLOWEST OF THE SOLUTIONS WITH THE FRONT FINALLY EXITING THE AREA
BY LATE MONDAY AFTERNOON. THE GFS HAS THE FRONT EXITING BY LATE
SUNDAY NIGHT. WILL CONTINUE TO SIDE WITH THE ECMWF KEEPING SHOWER
AND THUNDERSTORM CHANCES ACROSS THE AREA SUNDAY NIGHT...SHIFTING
THEM MAINLY EAST OF THE MISSISSIPPI RIVER ON MONDAY. HIGH PRESSURE
WILL BUILD INTO THE REGION BEHIND THE FRONT LATE MONDAY INTO
TUESDAY. LOOK FOR HIGHS TO FALL INTO THE UPPER 60S TO LOWER 70S.
AN UPPER TROUGH WILL PUSH INTO THE PACIFIC NORTHWEST ON TUESDAY
AND MOVE EAST INTO THE NORTHERN PLAINS. THE ECMWF AND GFS ARE
SHOWING SOME DIFFERENCES WITH THIS FEATURE. THE ECMWF BRINGS THE
TROUGH INTO THE NORTHERN PLAINS...WITH A BROAD UPPER TROUGH
DEVELOPING OVER THE NORTHWEST CONUS THROUGH THURSDAY. THE GFS
SHOWS THE TROUGH DIGGING SOUTH THROUGH THE CENTRAL ROCKIES LATE
TUESDAY THROUGH WEDNESDAY AND EJECTING INTO THE PLAINS DURING THE
DAY ON THURSDAY. A MORE ACTIVE PATTER LOOKS TO TAKE SHAPE IN THE
WEDNESDAY THROUGH THURSDAY TIME FRAME AS FLOW ALOFT TURNS SOUTHWEST
ACROSS THE FORECAST AREA. EMBEDDED SHORTWAVES IN THE SOUTHWEST
FLOW ALOFT WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE
AREA DURING THIS PERIOD. LOOK FOR HIGH TEMPERATURES TO WARM INTO
THE LOWER TO MID 70S ON WEDNESDAY...THEN CLIMB INTO THE UPPER 70S
BY THURSDAY.
&&
.AVIATION...TONIGHT AND FRIDAY
647 PM CDT THU MAY 17 2012
VFR CONDITIONS WILL PREVAIL THROUGH THE ENTIRE TAF PERIOD. GUSTY
WINDS WILL SUBSIDE THIS EVENING...BUT COULD STILL SEE SOME GUSTS TO
20 TO 25 KNOTS AT KRST THROUGH THE OVERNIGHT HOURS. WINDS IN THE
VALLEY AT KLSE WILL DROP BELOW 10 KNOTS. HOWEVER BOTH THE 17.18Z
NAM AND 17.21Z RAP BUFKIT SOUNDINGS SHOWING WINDS OF 40 TO 45
KNOTS BETWEEN 1K-2K FEET OVERNIGHT. THUS DID CONTINUE THE LLWS IN
THE KLSE TAF. GRADIENT REMAINS TIGHT ON FRIDAY...BUT WINDS NOT
EXPECTED TO BE AS STRONG AS TODAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
647 PM CDT THU MAY 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM....WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
422 AM EDT FRI MAY 18 2012
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 421 AM EDT FRI MAY 18 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER CNTRL
NAMERICA BTWN TROFS ALONG THE W COAST AND OVER QUEBEC. ALTHOUGH NO
REAL STRONG SHRTWV IS NOTICEABLE ROUNDING THE TOP OF THE RDG AND
AIRMASS TO THE S IS QUITE DRY PER 00Z MPX RAOB...A CLUSTER OF
SHRA/TS HAS DEVELOPED ON A WNW-ESE AXIS IN AREA OF VIGOROUS H85
THETA-E ADVCTN UNDER AREA OF UPR DVGC INDICATED BY VARIOUS MODELS
AT NOSE OF NOCTURNAL STRENGTHENING H85 SW LLJ BTWN HI PRES OVER LWR
MI AND LO PRES IN ERN NDAKOTA. SPC ANALYSIS INDICATES MUCAPE 500-
1000 J/KG IN THIS AREA NEAR H85 WARM FNT WITH THE STRONG H85 WARMING
SHARPENING LAPSE RATES. EVEN THOUGH THESE STORMS APPEAR TO BE
ELEVATED...SOME OF THEM HAVE CAUSED WIND GUSTS UP TO 30-40 KTS.
FARTHER TO THE S...THE AIRMASS IN THE WARM SECTOR IS VERY WARM AND
DRY. HI TEMPS OVER SW MN ROSE INTO THE LO 90S YDAY WITH DEWPTS AS LO
AS 35 TO 40 UNDER MOSUNNY SKIES. LLVL MSTR AT OMAHA WAS QUITE A BIT
GREATER AT 00Z THAN JUST TO THE N
MAIN FCST CONCERNS IN THE SHORT TERM ARE SHRA/TS CHCS THRU THIS MRNG
AND THEN FIRE WX THIS AFTN/SAT AS WARM AND DRY AIR TO THE S SURGES
INTO THE UPR LKS.
TODAY...EXPECT LINGERING SHRA/TS OVER THE KEWEENAW/NRN TIER IN THE
MRNG TO DRIFT TO THE NE WITH PASSAGE OF H85 WARM FNT UNDER BLDG UPR
RDG TO THE E OF DEEPENING TROF OVER THE W. STEADY SSW FLOW IN THE
WAKE OF THE WARM FROPA IS FCST TO PUSH H85 TEMPS AS HI AS 18C OVER
THE W HALF. MIXING TO H8 ON NAM FCST SDNGS INDICATES HI TEMPS WL
REACH 85 OVER THE W HALF WITH INCRSG SUNSHINE...BUT LOCATIONS
DOWNSTREAM OF LK MI WL BE COOLER. FORTUNATELY FOR FIRE WX
CONCERNS...MODELS ARE IN GOOD AGREEMENT SHOWING HIER LLVL MSTR
RETURNING INTO THE W HALF THRU THE DAY AS THE FLOW TAPS THE GREATER
MSTR SHOWN ON THE OMAHA RAOB AND THE SW WIND DIMINISHING A BIT WITH
ARRIVAL OF WEAKER PRES FALLS TO THE N. AXIS OF DRIER AIR WL REMAIN
OVER THE E HALF...BUT MODERATION OFF LK MI WL HOLD TEMPS DOWN IN
THAT AREA SOMEWHAT. SFC HEATING WL SUPPORT MIXING OF H95-9 WINDS UP
TO 35 KTS...STRONGEST OVER THE E. SEE THE FIRE WX DISCUSSION FOR
MORE DETAILS ON FIRE WX CONCERNS.
TNGT...CWA WL BE IN WARM SECTOR TNGT WITH UPR RDG OVER THE CNTRL GRT
LKS. STEADY SW FLOW/H925 WIND UP TO 35 KTS UNDER SHARP PRES GRADIENT
BTWN HI PRES RETREATING TO THE E AND LO PRES ADVANCING SLOWLY THRU
THE PLAINS WL LIMIT THE DIURNAL FALL OF TEMP DESPITE A MOCLR
SKY...ESPECIALLY ACRS THE DOWNSLOPE AREAS OF THE W AND NCNTRL AS
REFLECTED IN PREVIOUS FCST.
SAT...UPR MI WL REMAIN UNDER THE STEADY SSW FLOW BTWN HI PRES TO THE
E AND LO PRES TROF/COLD FNT ADVANCING THRU MN. WITH HI AMPLITUDE UPR
RDG OVER THE GRT LKS/NE CONUS...PREFER A SLOWER EWD PROGRESSION FOR
THE TROF AS SHOWN BY THE 00Z CNDN MODEL. SO RESTRICTED ANY POPS TO
FAR WRN LK SUP LATE IN THE DAY. MIXING TO H8-75 YIELDS HI TEMPS
APRCHG 90 OVER THE W HALF AWAY FM THE MODERATING INFLUENCE OF LK MI.
THIS DAYTIME MIXING WL ONCE AGAIN TAP H925 WINDS UP TO 35 KTS.
AXIS OF DRIEST AIR REMAINS OVER THE E...BUT FLOW OFF LK MI WL LIKELY
MODERATE MIXING/IMPACT ON SFC DEWPTS.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 421 AM EDT FRI MAY 18 2012
THE PERIOD STARTS 00Z SUN WITH A 500MB RIDGE AXIS JUST E OF THE CWA.
MORE IMPORTANTLY...TO OUR W WILL BE A 500MB TROUGH FROM NRN SASK TO
THE CENTRAL PLAINS STATES. THERE WILL BE A SHORTWAVE TROUGH PUSHING
THROUGH FAR WRN ONTARIO...WITH A 1002MB SFC LOW BENEATH IT. MODELS
SHOW FAIRLY GOOD AGREEMENT ON POSITION OF THESE FEATURES AND WITH
THE POSITION OF A SFC TROUGH/COLD FRONT JUST W OF THE CWA AT 00Z
SUN.
SAT NIGHT THROUGH MON...MODELS SHOW SAME GENERAL IDEA THAT THE
COLD FRONT WILL CROSS THE CWA...PRODUCING PRECIP ACROSS THE
AREA...BUT DIFFER IN TIMING. THE 00Z/18 GFS CONTINUES TO BE A FAST
OUTLIER WITH FROPA. THE 12Z/17 ECMWF CONTINUES TO BE ON THE SLOWER
SIDE...BUT IS CLOSER TO THE MORE MIDDLE GROUND 00Z/18 NAM AND 00Z/18
GEM MODELS THAN THE GFS IS. THE SLOWER SOLUTION IS ALSO SUPPORTED BY
THE FACT THAT THE SYSTEM WILL BE PUSHING INTO THE UPPER
RIDGE...WHICH TYPICALLY RESULTS IN SLOWER MOVEMENT OF THE SYSTEM.
USED A NAM/GEM/ECMWF MIX FOR THIS PART OF THE FORECAST. THIS RESULTS
IN THE FRONT MOVING INTO WRN UPPER MI AROUND 15Z SUN...THEN MOVING
THE CENTRAL UPPER MI AROUND 00Z MON...AND MOVING TO FAR ERN UPPER BY
AROUND 09Z MON. BULK OF MOISTURE...CLOUDS AND PRECIP WILL BE ALONG
AND BEHIND THIS ANAFRONT...ALLOWING FOR PLENTY OF TIME FOR SFC
HEATING AND DESTABILIZATION SUN OVER CENTRAL AND WESTERN UPPER MI.
HIGHS SUN LOOK TO BE IN THE MID TO UPPER 70S OVER CENTRAL AND PARTS
OF WRN UPPER MI...AND EVEN AS HIGH AS THE MID 80S OVER SOUTH CENTRAL
AND FAR ERN UPPER MI. MODELS SHOW SBCAPE OF 1000-1500J/KG AHEAD OF
TO JUST BEHIND THE COLD FRONT....WITH 0-6KM BULK SHEAR AROUND 30KTS.
CANNOT RULE OUT POSSIBILITY OF AN ISOLATED SEVERE THREAT FROM
CONVECTION SUN AFTERNOON/EVENING...BUT NOT CONFIDENT ENOUGH TO
MENTION SPECIFICALLY IN HWO. I THINK THE BEST CHANCE FOR SEVERE
THUNDERSTORMS WOULD BE OVER SOUTH CENTRAL UPPER MI AS THE FRONT
INTERACTS WITH LAKE MICHIGAN LAKE BREEZE BOUNDARIES. DID UP POPS FOR
THE PERIOD TO INCLUDE SOME LIKELY POPS...WHICH I WAS COMFORTABLE
DOING GIVEN PWATS AT 200 PERCENT OF NORMAL AND SLOW MOVEMENT OF THE
FRONT THROUGH GOOD INSTABILITY.
SFC HIGH PRESSURE MOVES IN BEHIND THE SFC TROUGH...AND MOVES E OF
THE CWA WED AS AN UPPER RIDGE MOVES OVERHEAD. THIS UPPER RIDGE GETS
SHUNTED E AS A LOW PRESSURE SYSTEM MOVES IN THE NRN PLAINS...BUT
THERE IS A LOT OF DISAGREEMENT BETWEEN MODELS ON THE STRENGTH AND
LOCATION OF THIS SYSTEM. MOST OF THE CWA SHOULD STAY DRY TUE THROUGH
THU...WITH A GENERAL WARMING TREND MON THROUGH THU.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 138 AM EDT FRI MAY 18 2012
A LINE OF CONVECTION FORMING NORTH OF A WARM FRONT OVER CNTRL MN IS
BRUSHING FAR WRN UPR MI WITH SHRA AND POSSIBLE ISOLD TSRA. AS THIS
WARM FRONT LIFTS NORTH ACROSS THE AREA TONIGHT SO WILL THE LINE OF
CONVECTION LIFT NORTH ACROSS THE WRN CWA. ALTHOUGH THE CONVECTION IS
LIKELY TO WEAKEN SLOWLY...OPTED TO INCLUDE MENTION OF TS AT CMX FROM
08Z-11Z. MAIN HAZARD AT ALL TAF SITES TONIGHT IS LOW LEVEL WIND
SHEAR AS SOUTHWEST LOW-LEVEL JET UP TO 45 KTS MOVES OVER THE AREA.
SFC WINDS WILL BE GENERALLY LIGHT AND MAINLY SOUTH OR SOUTH-
SOUTHEAST DIRECTION SO THERE WILL BE SOME DIRECTIONAL SHEAR AS WELL.
ANY LLWS WILL END AROUND SUNRISE FRIDAY. GUSTY SW WINDS AOA 25 KT
WILL DEVELOP FRIDAY AS MID CLOUDS SCATTER OUT. GIVEN THE DRY AIR OVR
THE REGION...EVEN IF SHRA/TSRA OCCUR...EXPECT VFR CONDITIONS. LOOK
FOR LLWS AGAIN BY FRI EVENING AS DIURNAL MIXING DIMINISHES SFC WIND
SOMEWHAT BUT LOW-LVL JET MAX OF 35 TO 40 KT REMAINS OVER THE AREA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 421 AM EDT FRI MAY 18 2012
WINDS ACROSS LAKE SUPERIOR SHOULD REMAIN BELOW 25KTS THROUGH THE
PERIOD. HIGH PRESSURE ACROSS THE LOWER GREAT LAKES WILL SLOWLY MOVE
TO NEW ENGLAND TODAY INTO SATURDAY. LOW PRESSURE OVER SOUTHERN
SASKATCHEWAN AND THE DAKOTAS WILL PUSH ACROSS THE NORTHERN AND
CENTRAL PLAINS THROUGH SATURDAY...BEFORE SLIDING NORTH INTO ONTARIO
SATURDAY. THIS WILL ALLOW A COLD FRONT TO PUSH ACROSS THE UPPER
GREAT LAKES SUNDAY INTO EARLY MONDAY. BEHIND THE FRONT...HIGH
PRESSURE WILL BUILD IN FROM THE CENTRAL AND NORTHERN PLAINS THROUGH
TUESDAY.
&&
.FIRE WEATHER...
ISSUED AT 421 AM EDT FRI MAY 18 2012
DRY SPELL THIS SPRING IS LEADING TO ANOTHER ACTIVE PERIOD OF FIRE
WX. FIRE WEATHER WATCHES ARE IN EFFECT FOR ALL OF UPR MI. A
PROLONGED PERIOD OF AT LEAST NEAR CRITICAL FIRE WX CONDITIONS IS ON
TAP FOR THIS AFTERNOON THROUGH SAT AFTERNOON.
AXIS OF STRONGER WINDS/LOWEST H95-85 SPECIFIC HUMIDITY LINES UP OVER
THE E THIS AFTN...BUT SW FLOW OFF LK MI PRESENTS A CHALLENGE AS TO
HOW MUCH COOLING/MOISTENING WILL OCCUR RELATED TO THE LAKE
MODERATION. ALTHOUGH MAX TEMPS OVER THE W WILL BE HIER...GRADUAL
ARRIVAL OF MOISTER AIR WILL TEND TO MITIGATE THE DIURNAL FALL OF RH.
CONSIDERING THE SHOWERS THAT FELL OVER MOST OF THE AREA EARLY THIS
MRNG AND EXPECTED MIN RH IN THE 25-30 PERCENT RANGE...OPTED TO ISSUE
A WILDFIRE POTENTIAL STATEMENT IN LIEU OF A RED FLAG WARNING EVEN
THOUGH DEEP MIXING THIS AFTERNOON WILL TRANSPORT STRONGER WINDS TO
THE SFC AT TIMES.
STEADY S WIND TNGT WL LIMIT DIURNAL FALL OF TEMP...EXACERBATING THE
DRYNESS.
ON SAT...ANOTHER DAY WHERE THE AXIS OF DRIEST AIR WILL BE ACROSS ERN
UPR MI. ALTHOUGH DEEP MIXING THAT WILL TAP STRONGER WINDS OFF THE
SFC WOULD ALSO TEND TO LOWER THE MIN RH...FLOW OFF LAKE MI WILL
MODERATE THE FALL OF RH. EXPECTED MIN RH AND POTENTIAL FOR GUSTY
WINDS AFTER A NIGHT OF LIMITED RH RECOVERY JUSTIFIED MAINTAINING THE
GOING FIRE WX WATCH IN THE AFTERNOON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING FOR MIZ001>015-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...VOSS/KC
MARINE...TITUS
FIRE WEATHER...KC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1213 AM CDT FRI MAY 18 2012
.AVIATION...06Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE
NEXT 24 HOURS. PRIMARY CONCERN THROUGH THE NEXT 24 HOURS WILL BE
SURFACE WINDS...WITH SUSTAINED SOUTHERLY WINDS INCREASING TO
AROUND 25KTS...AND GUSTING TO AROUND 35KTS...BY LATE FRIDAY
MORNING OR EARLY FRIDAY AFTERNOON AS BOUNDARY LAYER MIXING DEEPENS
DUE TO DIABATIC HEATING. SURFACE WINDS WILL THEN DIMINISH BY 02Z
AS DIABATIC HEATING IS LOST AND THE BOUNDARY LAYER DECOUPLES FROM
THE STRONGER WINDS ALOFT. THE LOW LEVEL PRESSURE GRADIENT SHOULD
KEEP SUSTAINED SURFACE WINDS UP AROUND 15KTS THROUGH SUNRISE
FRIDAY...THUS PREVENTING THE ONSET OF LLWS. LLWS HAS BEEN KEPT OUT
OF THE TAF AS A RESULT...BUT IT IS IMPORTANT TO NOTE THAT LLWS
INSERTION MAY BE NEEDED IF SURFACE WINDS DO MANAGE TO WEAKEN MUCH
BELOW 15KTS THROUGH SUNRISE FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 256 PM CDT THU MAY 17 2012/
SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT...WINDY CONDITIONS HAVE
DEVELOPED ACROSS MUCH OF THE FORECAST AREA TODAY AS DEEP MIXING HAS
BEEN REALIZED ALONG WITH A TIGHTENING PRESSURE GRADIENT IN RESPONSE
TO AN AREA OF SURFACE LOW PRESSURE TO OUR WEST. DO NOT EXPECT THESE
WINDS TO DIMINISH RAPIDLY THROUGH THE LATE AFTERNOON AND EARLY
EVENING HOURS AS PRESSURE GRADIENT WILL BE SLOW TO RELAX AND WINDS
FROM ALOFT WILL NOT DECOUPLE UNTIL AFTER SUNSET...SO WENT AHEAD AN
KEPT WIND ADVISORY GOING UNTIL 02Z THIS EVENING. IN ADDITION TO THE
WINDS...THERE REMAINS A SLIGHT CHANCE FOR A FEW THUNDERSTORMS THIS
EVENING ACROSS THE WESTERN FRINGES OF THE FORECAST AREA...AS FORCING
FROM WELL DEFINED UPPER LEVEL LOW MAY HELP INITIATE A FEW STORMS.
BOTH 12Z HRRR AND WRF HINT AT THIS TYPE OF DEVELOPMENT...BUT
CONFIDENCE NOT HIGH ENOUGH TO INCREASE COVERAGE AS INSTABILITY
REMAINS FAIRLY MARGINAL AND SIGNIFICANT COVERAGE IS NOT EXPECTED. IF
STORMS DO DEVELOP HOWEVER...MAIN THREAT APPEARS TO BE VERY GUSTY
WINDS AND SMALL HAIL.
OVERNIGHT...THE COMBINATION OF A SCT-BKN CIRRUS SHIELD AND CONTINUED
BREEZY SOUTHERLY WINDS SHOULD KEEP TEMPERATURES ELEVATED ABOVE
SEASONAL LEVELS...WITH LOW TEMPERATURES STRUGGLING TO FALL TO NEAR
60 IN MOST LOCATIONS.
WHILE DRY CONDITIONS ARE EXPECTED TO PREVAIL ON FRIDAY...ANOTHER
WINDY DAY APPEARS TO BE IN STORE ACROSS THE REGION AS THE PRESSURE
GRADIENT REMAINS TIGHT ACROSS THE REGION AND ONCE AGAIN GOOD MIXING
IS ANTICIPATED. WHILE A WIND ADVISORY MAY EVENTUALLY BECOME
NECESSARY ACROSS THE EASTERN HALF OF THE FORECAST AREA DURING THE
AFTERNOON HOURS...DECIDED TO HOLD OFF AT THIS POINT AS WE PRESENTLY
ALREADY HAVE AN ADVISORY HIGHLIGHTED FOR TODAY. DID HOWEVER INCLUDE
ADVISORY LEVEL WINDS FOR MUCH OF THE EASTERN HALF OF THE AREA DURING
THE AFTERNOON HOURS TOMORROW IN LATEST GRIDS. IN ADDITION TO
WINDS...EXPECT ANOTHER VERY WARM AFTERNOON FOR MID MAY...AND
INCREASED AFTERNOON TEMPS SEVERAL DEGREES IN RESPONSE TO WARMING 850
MB TEMPS AND A WARM START TO THE DAY ANTICIPATED.
LONG TERM...FRIDAY NIGHT THROUGH THURSDAY. THE PRIMARY WEATHER
FEATURES ARE A COLD FRONT THAT WILL TRACK ACROSS THE CWA ON SATURDAY
AND THEN A WESTERN CONUS UPPER TROUGH THAT DEVELOPS BY THE MIDDLE
OF NEXT WEEK.
FRIDAY NIGHT...MOST FORECAST MODELS ARE DRY FOR OUR FORECAST AREA
WITH THE BETTER CHANCE OF SHOWERS AND THUNDERSTORMS LOCATED ACROSS
PORTIONS OF WESTERN AND NORTHERN NEBRASKA. WILL CONTINUE WITH A
SLIGHT CHANCE OF THUNDERSTORMS ACROSS OUR NORTHWEST
ZONES...PRIMARILY NORTHWEST OF A HOLDREGE TO GRAND ISLAND LINE.
SATURDAY...THIS WILL BE OUR BEST CHANCE OF SEEING SHOWERS AND
THUNDERSTORMS WITHIN THE NEXT 5 DAYS...OR AT LEAST THROUGH TUESDAY.
AN UPPER LEVEL SHORT WAVE WILL SLIDE ACROSS THE CENTRAL PLAINS
ACCOMPANIED BY A FAIRLY STRONG SFC COLD FRONT. THE MORNING SHOULD BE
DRY...BUT SHOWERS AND THUNDERSTORMS WILL FORM ALONG AND BEHIND THE
COLD FRONT BY MID TO LATE AFTERNOON. THE COLD FRONT WILL PRIMARILY
TRACK ACROSS OUR CWA DURING THE AFTERNOON HOURS...BUT MAY NOT EXIT
OUR FAR SOUTHEASTERN ZONES UNTIL AROUND OR A BIT AFTER SUNSET. THERE
MAY BE TWO AREAS OF PRECIPITATION ASSOCIATED WITH THIS SYSTEM. THE
FIRST WILL BE AN AREA OF STRATIFORM RAIN SHOWERS WITH GENERAL NON
SEVERE THUNDERSTORMS WELL BEHIND THE FRONT. THE SECOND AREA WILL BE
STRONG TO SEVERE THUNDERSTORMS THAT SHOULD FORM RIGHT ALONG OR VERY
NEAR THE COLD FRONT. INSTABILITY WILL BE RATHER HIGH ALONG THE FRONT
BY LATE AFTERNOON...ALTHOUGH THE WIND SHEAR WILL BE MORE MARGINAL
AND UNIDIRECTIONAL. BULK SHEAR VECTORS ARE ORIENTED RATHER PARALLEL
TO THE SFC COLD FRONT AND THERE SHOULD BE PRETTY GOOD FORCING RIGHT
ALONG THE FRONT. CONSEQUENTLY...THUNDERSTORMS MAY TEND TO BE MORE
LINEAR OR MULTI CELL RATHER THAN DISCRETE SUPERCELLS. THE PRIMARY
THREAT WILL BE LARGE HAIL AND DAMAGING WINDS.
HIGH TEMPERATURES SATURDAY WILL BE A DIFFICULT CALL AND GREATLY
DEPEND ON THE PROGRESSION OF THE COLD FRONT AND CLOUD COVER. WOULD
NOT BE SURPRISED TO SEE A FEW 90S ACROSS SOUTHEAST ZONES...WHILE
NORTHWEST ZONES MAY STALL OUT IN THE UPPER 70S TO AROUND 80 BY EARLY
AFTERNOON. TEMPERATURES MAY EVEN FALL A FEW DEGREES BY EARLY TO MID
AFTERNOON FOR AREAS THAT SEE THE EARLIER FRONTAL PASSAGE.
SUNDAY...GREAT DAY BEHIND THE COLD FRONT WITH DRY WEATHER AND HIGHS
IN THE LOWER TO MID 70S
MONDAY AND TUESDAY...EXPECT DRY WEATHER TO CONTINUE WITH A GRADUAL
MODERATING TREND AS A WEAK UPPER RIDGE MOVES ACROSS AREA. HIGHS
SHOULD CLIMB FROM THE 70S ON MONDAY BACK INTO THE 80S BY TUESDAY.
WEDNESDAY AND THURSDAY...AN UPPER LEVEL TROUGH WILL DEEPEN ACROSS
THE NORTHWESTERN CONUS AND MAY BEGIN TO ENHANCE THE FORCING/LIFT
OVER THE CENTRAL PLAINS. THERE IS STILL A GOOD DEAL OF MODEL
UNCERTAINTY WITH THIS SYSTEM AND HOW IT WILL EVOLVE AND PUSH OUT
INTO THE PLAINS. THERE WILL BE AT LEAST SOME THREAT OF
THUNDERSTORMS ACROSS THE CENTRAL OR NORTHERN PLAINS...BUT DIFFICULT
TO GET INTO SPECIFICS AT THIS TIME GIVEN THE MODEL UNCERTAINTY.
TEMPERATURES ARE MORE LIKELY TO BE ABOVE NORMAL IN THE 80S AHEAD OF
THIS NEXT TROUGH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...BRYANT
SHORT TERM...ROSSI
LONG TERM...WESELY
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1120 PM MDT THU MAY 17 2012
.AVIATION...
A SFC TROUGH WILL REMAIN IN PLACE OVER THE REGION...WITH VARIABLE
WINDS ALONG AND NEAR THE SFC TROUGH. THIS INCLUDES KRAP. ISOLD
SHRA/TS WILL BE POSSIBLE THROUGH DAWN...WITH GUSTY WINDS POSSIBLE
FROM OUTFLOW. A STRONGER UPPER LEVEL IMPULSE WILL TRAVERSE THE
NORTHERN PLAINS FRIDAY AFTERNOON/EVENING...FORCING THE DEEPENING
OF SFC LOW PRESSURE WITH INCREASING CHANCES FOR SHRA/TS IN THE
AFTERNOON. WINDS WILL STRENGTHEN OUT OF THE NW BEHIND THE SFC
TROUGH...WITH GUSTY SSW WINDS TO THE EAST OVER SOUTH CENTRAL SD.
NORTH WINDS WILL BECOME QUITE GUSTY IN THE LEE OF THE BLACK HILLS
FRIDAY EVENING AND OVERNIGHT INTO SATURDAY...WITH GUSTS OF 40 TO
50 KNOTS OR HIGHER NOT OUT OF THE QUESTION.
&&
.PREV DISCUSSION... /ISSUED 752 PM MDT THU MAY 17 2012/
UPDATE...
PERTURBED SW FLOW CONTINUES TO SUPPORT AN ARRAY OF IMPULSES OVER
THE NORTHERN PLAINS AND CENTRAL ROCKIES...WITH EACH DISTURBANCE
SUPPORTING ISOLD/SCT SHRA/TS. STRONGEST LOCAL MID LEVEL FORCING
SEEMS TO BE ASSOCIATED WITH THE A COMPLEX OF TS OVER NORTHERN
CAMPBELL COUNTY...WHICH IS ON TRACK TO SKIRT MUCH OF THE FAR NW
THIS EVENING. HIGH LCL/S WITH STEEP LL/MID LAPSE RATES LOOKS TO
SUPPORT A STRONG GUSTY WIND AND SMALL HAIL THREAT WITH THE
STRONGEST CELLS. ADJUSTED POPS TO ACCOUNT FOR ONGOING
ACTIVITY/TRENDS...WITH EXPANSION OF SLIGHT CHANCE POPS TO COVER
THE FAR SE.
PREV DISCUSSION... /ISSUED 257 PM MDT THU MAY 17 2012/
DISCUSSION...
A BROAD...FLAT LONG WAVE TROF EXTENDS FROM COAST TO COAST THIS
MORNING WITH A SHORT WAVE TROF OVER CO. MODELS ARE IN GOOD
AGREEMENT IN BRINGING A STRONGER TROF INLAND FROM THE PAC TO A
POSITION JUST W OF OUR CWA BY 12Z SAT. AIR MASS OVER THE AREA IS
CHARACTERIZED BY VERY STEEP LOW LEVEL LAPSE RATES AND LIMITED
MOISTURE. A FEW TSTMS HAVE DVLPD THIS AFTN MAINLY OVER THE HIER
TERRAIN OF THE BLACK HILLS WITH A FEW SHOWERS OVER NE WY AND NW SD.
GIVEN THE DRY LOW LVLS AND STEEP BELOW CLOUD LAPSE RATES THESE
STORMS COULD PRODUCE STRONG...GUSTY SFC WINDS DURING THE EVNG
HOURS. THE HRRR MODEL SHOWS A N TO S LINE OF TSTMS FROM NW SD
THROUGH RAP AND S WARD AT 03Z.
WITH THE APPROACH OF THE SECOND TROF FRIDAY AFTN THERE IS THE
CHANCE FOR MORE WIDESPREAD AND VIGOROUS CONVECTION. MOISTURE WILL
REAMIN LIMITED...BUT SFC BASED CAPE FCSTS OF ABT 1000 J/KG BY THE
18Z NAM LOOK REASONABLE. SFC TO 6KM SHEAR IS FCST TO RANGE FROM
ABOUT 40KTS OVER NW SD TO 20 KTS SE PORTIONS OF OUR CWA. A
BOUNDARY FROM TONIGHTS CONVECTION MAY PROVIDE SOME FOCUS AND WILL
BE REINFORCED BY INCREASING NRLY FLOW OVER WRN AND NWRN PORTIONS
OF THE CWA. NAM FCSTS THIS BOUNDARY TO BE FROM S OF RAP TO ROUGHLY
PHP AT 21Z FRIDAY.
WITH THE APPROACHING TROF...500 MB Q VECTOR CONVERGENCE REMAINS
OVER THE AREA FRIDAY NIGHT INTO SATURDAY EVG. POST FRONTAL SHOWERS
AND TSTMS SHOULD CONTINUE OVER MUCH THE AREA...GRADUALLY ENDING
FROM THE NW.
EXTENDED...AN UPPER RIDGE WILL BUILD INTO THE REGION EARLY NEXT WEEK
BRINGING DRY CONDITIONS. TEMPERATURES WILL BE NEAR AVERAGE
SUNDAY...WITH A GRADUAL WARMING TREND TO START THE WORK WEEK. MODELS
CONTINUE TO SHOW A SLOW MOVING UPPER TROUGH PUSHING INTO THE REGION
LATE TUESDAY INTO WEDNESDAY AND THURSDAY. MODELS CONSISTENCY IS
STILL LACKING (ECMWF CLOSES THE SYSTEM OFF WHILE GEM/GFS KEEP IT
OPEN)...BUT THIS COULD BRING A ROUND OF SHOWERS SHOWERS AND
THUNDERSTORMS TO THE AREA.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...BARBER
LONG TERM...77
AVIATION/UPDATE...JC
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
411 AM MDT FRI MAY 18 2012
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 411 AM MDT FRI MAY 18 2012
TODAY...CRITICAL FIRE WEATHER CONDITIONS WILL DEVELOP OVER MUCH OF
THE FORECAST AREA BEGINNING LATE THIS MORNING AND CONTINUING INTO
THIS EVENING. A PACIFIC TROUGH AND COLD FRONT WILL MOVE ACROSS
THE AREA TODAY. THE SHORT-TERM MODELS ARE CAPTURING THE CURRENT
SITUATION FAIRLY WELL AND IN GOOD AGREEMENT. SATELLITE AND SURFACE
ANALYSIS SHOW THE FRONT OVER EXTREME WESTERN UT EARLY THIS MORNING.
PREFRONTAL...WARM ADVECTION RELATED MID CLOUDS WILL CONTINUE
FLOWING OVER THE FORECAST AREA THIS MORNING. THE LOWEST CLOUD
BASES DETECTED OVER THE CWA HAS BEEN 11K FT SO FAR...SO LITTLE OR
NO PRECIP REACHING THE GROUND FROM THESE CLOUDS.
THE RUC SHOWS THE FRONT JUST ENTERING THE EASTERN UT PORTION OF THE
CWA ABOUT NOON. THE FRONT SHOULD REACH THE CO/UT BORDER AROUND
00Z... SO MOST OF TODAY SHOULD BE PREFRONTAL WITH STRONG SW WINDS
AND WARM AND DRY CONDITIONS. HAVE CONTINUED THE RED FLAG WARNING
FOR MOST OF WESTERN CO...BUT CANCELLED THE PORTION IN ROUTT COUNTY
AND THE FLATTOPS AS BELIEVE THE RH WILL NOT LOWER ENOUGH.
UPPER TROUGH WILL BE MOVING ACROSS OUR CWA TONIGHT AND LATEST
MODELS HAVE FOLLOWED TREND OF PREVIOUS RUNS WITH MUCH SIMILARITY.
CONFIDENCE RATHER HIGH ON THE TIMING..INTENSITY...AND MOISTURE
CONTENT FOR OUR CWA. THEREFORE...SIGNIFICANTLY BOOSTED POPS
OVERNIGHT THROUGHOUT THE NORTHERN AND MOST CENTRAL ZONES OF
WESTERN COLORADO. FOR NW COLORADO MOUNTAIN ZONES RAISED THEM FROM
SLIGHT CHANCE TO LIKELY CATEGORIES FROM MIDNIGHT THROUGH SUNRISE.
EXPECT THOSE ZONES TO GENERALLY RECEIVE 0.15 TO 0.25 OF AN INCH OF
WATER.
ALTHOUGH MOISTURE SHOULD GRADUALLY DECREASE FROM THE WEST ACROSS OUR
CWA ON SATURDAY AS THE UPPER TROUGH MOVES EAST...EXPECT SOME
LINGERING SHOWERS MAINLY ON UPWIND SIDE OF THE NORTHERN AND CENTRAL
MOUNTAINS OF WESTERN COLORADO. SHOULD BE MUCH COOLER THROUGHOUT OUR
CWA ON SATURDAY...WITH THICKNESS VALUES EXPECTED TO DROP ABOUT
90-100 METERS FROM FRIDAY...RESULTING IN MAX TEMPERATURES ON
SATURDAY GENERALLY 5 TO 10 DEGREES COOLER THAN FRIDAY.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 411 AM MDT FRI MAY 18 2012
MIGRATORY UPPER RIDGE MOVES INTO OUR AREA BY SUNDAY WITH MUCH DRIER
AIR FOR OUR REGION. WARM AIR ADVECTION LIKELY TO RESULT IN MAX
TEMPERATURES 5 TO 10 DEGREES WARMER THAN SATURDAY THROUGHOUT OUR CWA.
THE RIDGELINE WILL PASS EAST OF THE AREA MONDAY WITH INCREASING SW
FLOW ALOFT THEREAFTER AS THE NEXT PACIFIC TROUGH MOVES ONSHORE.
THIS TROUGH IS EXPECTED TO BEGIN AFFECTING NORTHERN UT TUE THEN
PUSH THROUGH THE FORECAST AREA TUE NIGHT. THE MAIN JET AXIS IS
PROGGED TO REMAIN OVER THE AREA TUE THROUGH FRI. A SERIES OF
MODERATE PACIFIC SYSTEM WILL MOVE THROUGH DURING THE WEEK
BEGINNING TUE NIGHT AND WED...THEN AGAIN WED NIGHT AND THU.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 411 AM MDT FRI MAY 18 2012
VFR CONDITIONS WILL PREVAIL TODAY WITH MAIN MID AND HIGH LEVEL
CLOUDS OVER THE AREA. THERE IS A SLIGHT CHANCE OF A SHOWER TODAY
BUT CEILINGS AND VSBY SHOULD REMAIN IN THE VFR CATEGORY.
&&
.FIRE WEATHER...
ISSUED AT 411 AM MDT FRI MAY 18 2012
WITH THE TROUGH AND COLD FRONT TODAY AND THIS EVENING...STRONG
SOUTHWEST WINDS WILL MIX TO THE SURFACE BY MID AND LATE MORNING.
RELATIVE HUMIDITIES AT 15% OR LESS WILL BECOME WIDESPREAD LATE THIS
MORNING AS WELL. HAVE CONTINUED THE RED FLAG WARNING FOR MOST OF
THE AREA...BUT HAVE CANCELLED THE PORTION OF THE WARNING IN ZONE
201...ROUTH COUNTY AND PORTIONS OF THE FLATTAPS...AS THE HUMIDITY
DOESN`T SEEM TO GET LOW ENOUGH. AS THE FRONT MOVES THROUGH...
SURFACE WINDS SHOULD SHIFT ABRUPTLY TO THE NORTHWEST.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...RED FLAG WARNING FROM 11 AM THIS MORNING TO 10 PM MDT THIS
EVENING FOR COZ203-207-290-292-293.
UT...NONE.
&&
$$
SHORT TERM...CC
LONG TERM...15
AVIATION...CC
FIRE WEATHER...CC
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
644 AM CDT FRI MAY 18 2012
.UPDATE...
OBS DATA THROUGH 11Z CONTINUES TO SHOW UPPER 30S AND LOWER 40 DEW
POINTS ACROSS THE AREA. THE ATMOSPHERE IS NOW HEATING AND DEEPER
MIXING WILL BEGIN ONCE THE INVERSION BREAKS AROUND MID MORNING.
PRELIMINARY SOUNDING DATA RECEIVED SO FAR FROM THE 12Z FLIGHT
SUGGESTS WE SHOULD EASILY MIX TO 850MB TODAY WHICH WOULD KEEP DEW
POINTS WHERE THEY ARE RIGHT NOW OR POSSIBLY DROP FURTHER IN SPITE
OF THE MOISTURE SLOWLY BEING ADVECTED INTO THE AREA. SOME MINOR
TWEEKS TO THE FCST WILL BE DONE FOR DEW POINTS THAT MAY OR MAY NOT
INCLUDE A SLIGHT CHANGE TO MAX TEMPS. ..08..
&&
.AVIATION...
VFR WX WILL BE SEEN THROUGH 12Z/19. RADAR WIND PROFILES CONTINUE
TO SUGGEST LLWS ACROSS EASTERN IOWA/NORTHERN ILLINOIS BUT THIS HAS
NOT BEEN SUBSTANTIATED BY ACFT. RAP MODEL TRENDS THE PAST SEVERAL
HOURS INDICATE LOWER WIND SPEEDS AT 1-2KFT AGL. THUS THE LLWS
THREAT WAS REMOVED FROM THE 12Z TAFS AS THE THREAT APPEARS TO BE MARGINAL
AT BEST. THERE IS STILL A CONCERN FOR LLWS DVLPG AFT 03Z/19 BUT IT
WAS LEFT OUT OF THE 12Z TAFS. ..08..
&&
.PREV DISCUSSION... /ISSUED 257 AM CDT FRI MAY 18 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE EASTERN GREAT LAKES WITH
A COLD FRONT FROM WESTERN MINNESOTA INTO WYOMING. DEW POINTS WERE IN
THE 30S ACROSS THE GREAT LAKES WITH A NARROW FEED OF 50 DEW POINTS
FROM THE SOUTHERN PLAINS INTO WESTERN MINNESOTA. SATELLITE TRENDS
INDICATE MAINLY CI/CS BLOW OFF OVER THE AREA FROM EARLIER CONVECTION
IN THE PLAINS.
SHORT TERM...TODAY AND TONIGHT
QUIET AND DRY CONDITIONS WILL CONTINUE TODAY AND TONIGHT ACROSS THE
AREA. THE DRY ATMOSPHERE COMBINED WITH THE NOW DRY GROUND WILL ALLOW
LARGER THAN NORMAL DIURNAL TRENDS ACROSS THE AREA.
ALTHOUGH MOISTURE WILL BE TRANSPORTED INTO THE CWFA DURING THE
DAY...DEEP MIXING WILL CAUSE OVERALL MOISTURE LEVELS TO DROP DURING
THE DAY. BASED ON WHAT OCCURRED YESTERDAY WEST OF THE AREA...DEW
POINTS HOLDING OR DROPPING INTO THE 40-45 DEGREE RANGE SEEMS VERY
PLAUSIBLE. IT IS NOT OUT OF THE REALM OF POSSIBILITY THAT DEW POINTS
MAY DROP INTO THE UPPER 30S IN THE EASTERN CWFA. ..08..
LONG TERM...SATURDAY THROUGH NEXT THURSDAY
A WARM PERIOD OF WEATHER WILL PERSIST INTO SUNDAY...FOLLOWED BY A
BRIEF COOL DOWN FOR MONDAY INTO TUESDAY...FOLLOWED BY MORE WARMING.
THIS PORTION OF THE FORECAST IS REASONABLY CONFIDENT...BUT LITTLE
CONFIDENCE EXISTS ON TIMING AND COVERAGE OF RAINFALL CHANCES.
AS NOTED IN THE SHORT TERM...MOISTURE WITHIN MODEL GUIDANCE IS
SUSPECT TO SAY THE LEAST WITH THE GULF WEAKLY SUPPORTING MOISTURE
TRANSPORT THIS WEEKEND. DESPITE SLOW MOVEMENT OF THE FRONT SATURDAY
NIGHT INTO SUNDAY NIGHT OVER THE CWA...WEAK FORCING AND ONLY MODEST
MOISTURE LEAD ME TO BELIEVE THAT RAINFALL MAY NOT BE VERY IMPRESSIVE
AT ALL. SOME DIURNAL FLUX UPWARD IN PRECIP POTENTIAL MAY OCCUR ALONG
AND EAST OF THE MISSISSIPPI RIVER SUNDAY AFTERNOON...BUT THIS OF LOW
CONFIDENCE. WILL STAY CLOSE TO HPC GUIDANCE ON RAIN AMOUNTS.
MONDAY THROUGH WEDNESDAY APPEAR DRY...AS HIGH PRESSURE MIGRATES WEST
TO EAST OVER THE CWA. MONDAY MAY DEAL WITH SOME MID CLOUDS...AND IS
CERTAINLY THE COOLEST DAY...WITH HIGHS MAINLY IN THE LOWER 70S.
TUESDAY INTO WEDNESDAY...ROBUST WARMING WILL SEE A DAY IN THE MID
70S TUESDAY AND AROUND 80 WEDNESDAY.
PRECIP CHANCES RETURN FOR WEDNESDAY NIGHT THROUGH THURSDAY. THE
PATTERN WILL BE ACTIVE NEARBY...BUT AS MUCH GUIDANCE SUPPORTS STORMS
OVER THE DVN CWA...THERE IS MORE SUGGESTING THE TROF WILL BE MAINLY
WEST...WITH UPPER RIDGING AND CAPPING FOUND THIS FAR EAST. SO...WE
WILL BE EITHER WARM AND STORM BEGINNING WEDNESDAY NIGHT...OR JUST
PLAIN HOT AND DRY. ERVIN
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1150 AM EDT FRI MAY 18 2012
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FOR QUIET WEATHER AND A WARMING TREND
THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN UPDATE HAS BEEN ISSUED TO ACCOUNT FOR THE LATEST TRENDS IN TEMPS
AND DEW POINTS.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE AXIS
EXTENDING FROM THE ARKLATEX REGION INTO THE LOWER GREAT LAKES. AT
THE SURFACE, A 1025MB HIGH IS CENTERED ACROSS NEW ENGLAND AND
EXTENDS SOUTHWESTWARD INTO THE UPPER OHIO VALLEY. MEANWHILE, A
CLOSED LOW IS DEVELOPING OFF THE CAROLINA COAST. THE 12Z KPIT
SOUNDING INDICATES DEEP SUBSIDENCE AND DRY AIR ALOFT. THUS, CLEAR
SKIES ARE PREVAILING ACROSS THE AREA.
THE 500MB RIDGE WILL BUILD IN FURTHER INTO THE GREAT LAKES REGION
TODAY AND TONIGHT WITH ANTI-CYCLONIC FLOW ALOFT CENTERED ACROSS
NORTHERN OHIO BY 12Z SATURDAY. THIS WILL ALLOW ABUNDANT SUNSHINE TO
CONTINUE ACROSS THE REGION. HIGHS TODAY ARE A FEW DEGREES WARMER
THAN LAMP GUIDANCE, WARMING TO NEAR 80 ACROSS MUCH OF THE AREA.
WITH NEAR CALM WINDS AND CLEAR SKIES TONIGHT, RADIATIONAL COOLING
WILL ALLOW FOR TEMPERATURES TO STEADILY DROP OFF. OVERNIGHT LOWS
WILL RANGE FROM THE MID 40S ACROSS THE I-80 CORRIDOR AND EASTERN
RIDGES TO THE LOWER 50S ACROSS PORTIONS OF EASTERN OHIO AND
NORTH-CENTRAL WV.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
HIGH PRESSURE RIDGE WILL CONTINUE TO DOMINATE THE FORECAST THROUGH
AT LEAST SUNDAY AS SUGGESTED BY MOST GLOBAL MODELS. AS THE RIDGE
CONTINUES TO BUILD AND SLIDE TOWARD THE COAST...850MB TEMPERATURES
ALOFT WILL REACH 16C...WHICH SHOULD HELP TO BRING TEMPERATURES 5
TO 10 DEGREES ABOVE NORMAL SATURDAY AND SUNDAY. THOUGH CURRENT
FORECAST HIGHS ARE SLIGHTLY BELOW MOS GUIDANCE...WHICH LOOKED A
LITTLE TOO HIGH.
MODEL AGREEMENT THEN DIVERGES INTO SUNDAY NIGHT AND MONDAY ON THE
TIMING AND PLACEMENT OF THE MID-UPPER LEVEL CLOSED LOW OVER THE
SOUTHEAST. THERE CONTINUES TO BE A GROUPING BETWEEN THE
NAM/CANADIAN AND GFS/ECMWF. SINCE NOT MUCH HAS CHANGED IN THE
DETERMINISTIC MODELS WITH THE NEW RUNS...OPTED TO CONTINUE THE DRY
FORECAST FOR SUNDAY NIGHT...GRADUALLY BRINGING IN POPS FROM BOTH
THE EAST WITH THE RETROGRADING LOW AND THE WEST WITH THE SLOW
MOVING COLD FRONT BY LATE MONDAY. THIS WAS CLOSEST TO GFS/ECMWF
AND SREF ENSEMBLE MEAN THROUGH THE PERIOD. KEPT TEMPERATURES A FEW
DEGREES ABOVE MOS GUIDANCE AND STILL A FEW DEGREES ABOVE NORMAL
MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
WITH CONTINUED MODEL DISAGREEMENT...MAINTAINED A FORECAST CLOSE TO
HPC GUIDANCE WITH HEAVY EMPHASIS ON THE MOST RECENT GFS RUN WHICH
BRINGS THE COLD FRONT THROUGH THE REGION THE FASTEST MONDAY NIGHT
AND TUESDAY.
A SURFACE RIDGE PROGGED TO BUILD IN FROM THE MIDWEST LATE WEDNESDAY
INTO THURSDAY SHOULD PROVIDE A RETURN TO DRY WEATHER FOR THE MIDDLE
OF THE WEEK.
TEMPERATURES ARE FORECAST TO RANGE FROM 5 TO 10 DEGREES ABOVE NORMAL
THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD AS SURFACE HIGH
PRESSURE SLIDES EASTWARD FROM THE GREAT LAKES AND OVER NEW ENGLAND.
LGT NE SFC WND WL VEER TO THE E ON FRIDAY WITH PROGRESS OF THE HIGH.
.OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
HIGH PRESSURE WILL CONTINUE TO SUPPORT VFR CONDITIONS THROUGH THE
WEEKEND. A COLD FRONT APPROACHING FROM THE WEST WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS WITH THE POTENTIAL FOR RESTRICTIONS LATE
MONDAY THROUGH TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1006 AM EDT FRI MAY 18 2012
.UPDATE...
ISSUED AT 1005 AM EDT FRI MAY 18 2012
INCREASED POPS TO CATEGORICAL AND INCREASED SKY COVER FOR REST OF
MORNING AS BATCH OF SHRA/SCT TSRA MAINLY AFFECT AREAS FM MUNISING TO
NEWBERRY INTO EASTERN UPR MICHIGAN. BASED ON REPORTS SO FAR...EXPECT
RAIN AMOUNTS TO END UP LESS THAN 0.25 INCH MOST AREAS. SKIES HAVE
ALREADY CLEARED OVER WEST AND SOUTHWEST UPR MICHIGAN. 12Z GRB
SOUNDING POINTS TO MAX TEMPS AS WARM AS LOWER 90S. MAY NEED TO RAISE
TEMPS SOME OVER FCST...BUT WILL WAIT FOR TEMP TRENDS NEXT FEW HOURS
BEFORE MAKING SIGNIFICANT ADJUSTMENTS. REST OF FCST ON TRACK FOR
NOW.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 421 AM EDT FRI MAY 18 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER CNTRL
NAMERICA BTWN TROFS ALONG THE W COAST AND OVER QUEBEC. ALTHOUGH NO
REAL STRONG SHRTWV IS NOTICEABLE ROUNDING THE TOP OF THE RDG AND
AIRMASS TO THE S IS QUITE DRY PER 00Z MPX RAOB...A CLUSTER OF
SHRA/TS HAS DEVELOPED ON A WNW-ESE AXIS IN AREA OF VIGOROUS H85
THETA-E ADVCTN UNDER AREA OF UPR DVGC INDICATED BY VARIOUS MODELS
AT NOSE OF NOCTURNAL STRENGTHENING H85 SW LLJ BTWN HI PRES OVER LWR
MI AND LO PRES IN ERN NDAKOTA. SPC ANALYSIS INDICATES MUCAPE 500-
1000 J/KG IN THIS AREA NEAR H85 WARM FNT WITH THE STRONG H85 WARMING
SHARPENING LAPSE RATES. EVEN THOUGH THESE STORMS APPEAR TO BE
ELEVATED...SOME OF THEM HAVE CAUSED WIND GUSTS UP TO 30-40 KTS.
FARTHER TO THE S...THE AIRMASS IN THE WARM SECTOR IS VERY WARM AND
DRY. HI TEMPS OVER SW MN ROSE INTO THE LO 90S YDAY WITH DEWPTS AS LO
AS 35 TO 40 UNDER MOSUNNY SKIES. LLVL MSTR AT OMAHA WAS QUITE A BIT
GREATER AT 00Z THAN JUST TO THE N
MAIN FCST CONCERNS IN THE SHORT TERM ARE SHRA/TS CHCS THRU THIS MRNG
AND THEN FIRE WX THIS AFTN/SAT AS WARM AND DRY AIR TO THE S SURGES
INTO THE UPR LKS.
TODAY...EXPECT LINGERING SHRA/TS OVER THE KEWEENAW/NRN TIER IN THE
MRNG TO DRIFT TO THE NE WITH PASSAGE OF H85 WARM FNT UNDER BLDG UPR
RDG TO THE E OF DEEPENING TROF OVER THE W. STEADY SSW FLOW IN THE
WAKE OF THE WARM FROPA IS FCST TO PUSH H85 TEMPS AS HI AS 18C OVER
THE W HALF. MIXING TO H8 ON NAM FCST SDNGS INDICATES HI TEMPS WL
REACH 85 OVER THE W HALF WITH INCRSG SUNSHINE...BUT LOCATIONS
DOWNSTREAM OF LK MI WL BE COOLER. FORTUNATELY FOR FIRE WX
CONCERNS...MODELS ARE IN GOOD AGREEMENT SHOWING HIER LLVL MSTR
RETURNING INTO THE W HALF THRU THE DAY AS THE FLOW TAPS THE GREATER
MSTR SHOWN ON THE OMAHA RAOB AND THE SW WIND DIMINISHING A BIT WITH
ARRIVAL OF WEAKER PRES FALLS TO THE N. AXIS OF DRIER AIR WL REMAIN
OVER THE E HALF...BUT MODERATION OFF LK MI WL HOLD TEMPS DOWN IN
THAT AREA SOMEWHAT. SFC HEATING WL SUPPORT MIXING OF H95-9 WINDS UP
TO 35 KTS...STRONGEST OVER THE E. SEE THE FIRE WX DISCUSSION FOR
MORE DETAILS ON FIRE WX CONCERNS.
TNGT...CWA WL BE IN WARM SECTOR TNGT WITH UPR RDG OVER THE CNTRL GRT
LKS. STEADY SW FLOW/H925 WIND UP TO 35 KTS UNDER SHARP PRES GRADIENT
BTWN HI PRES RETREATING TO THE E AND LO PRES ADVANCING SLOWLY THRU
THE PLAINS WL LIMIT THE DIURNAL FALL OF TEMP DESPITE A MOCLR
SKY...ESPECIALLY ACRS THE DOWNSLOPE AREAS OF THE W AND NCNTRL AS
REFLECTED IN PREVIOUS FCST.
SAT...UPR MI WL REMAIN UNDER THE STEADY SSW FLOW BTWN HI PRES TO THE
E AND LO PRES TROF/COLD FNT ADVANCING THRU MN. WITH HI AMPLITUDE UPR
RDG OVER THE GRT LKS/NE CONUS...PREFER A SLOWER EWD PROGRESSION FOR
THE TROF AS SHOWN BY THE 00Z CNDN MODEL. SO RESTRICTED ANY POPS TO
FAR WRN LK SUP LATE IN THE DAY. MIXING TO H8-75 YIELDS HI TEMPS
APRCHG 90 OVER THE W HALF AWAY FM THE MODERATING INFLUENCE OF LK MI.
THIS DAYTIME MIXING WL ONCE AGAIN TAP H925 WINDS UP TO 35 KTS.
AXIS OF DRIEST AIR REMAINS OVER THE E...BUT FLOW OFF LK MI WL LIKELY
MODERATE MIXING/IMPACT ON SFC DEWPTS.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 421 AM EDT FRI MAY 18 2012
THE PERIOD STARTS 00Z SUN WITH A 500MB RIDGE AXIS JUST E OF THE CWA.
MORE IMPORTANTLY...TO OUR W WILL BE A 500MB TROUGH FROM NRN SASK TO
THE CENTRAL PLAINS STATES. THERE WILL BE A SHORTWAVE TROUGH PUSHING
THROUGH FAR WRN ONTARIO...WITH A 1002MB SFC LOW BENEATH IT. MODELS
SHOW FAIRLY GOOD AGREEMENT ON POSITION OF THESE FEATURES AND WITH
THE POSITION OF A SFC TROUGH/COLD FRONT JUST W OF THE CWA AT 00Z
SUN.
SAT NIGHT THROUGH MON...MODELS SHOW SAME GENERAL IDEA THAT THE
COLD FRONT WILL CROSS THE CWA...PRODUCING PRECIP ACROSS THE
AREA...BUT DIFFER IN TIMING. THE 00Z/18 GFS CONTINUES TO BE A FAST
OUTLIER WITH FROPA. THE 12Z/17 ECMWF CONTINUES TO BE ON THE SLOWER
SIDE...BUT IS CLOSER TO THE MORE MIDDLE GROUND 00Z/18 NAM AND 00Z/18
GEM MODELS THAN THE GFS IS. THE SLOWER SOLUTION IS ALSO SUPPORTED BY
THE FACT THAT THE SYSTEM WILL BE PUSHING INTO THE UPPER
RIDGE...WHICH TYPICALLY RESULTS IN SLOWER MOVEMENT OF THE SYSTEM.
USED A NAM/GEM/ECMWF MIX FOR THIS PART OF THE FORECAST. THIS RESULTS
IN THE FRONT MOVING INTO WRN UPPER MI AROUND 15Z SUN...THEN MOVING
THE CENTRAL UPPER MI AROUND 00Z MON...AND MOVING TO FAR ERN UPPER BY
AROUND 09Z MON. BULK OF MOISTURE...CLOUDS AND PRECIP WILL BE ALONG
AND BEHIND THIS ANAFRONT...ALLOWING FOR PLENTY OF TIME FOR SFC
HEATING AND DESTABILIZATION SUN OVER CENTRAL AND WESTERN UPPER MI.
HIGHS SUN LOOK TO BE IN THE MID TO UPPER 70S OVER CENTRAL AND PARTS
OF WRN UPPER MI...AND EVEN AS HIGH AS THE MID 80S OVER SOUTH CENTRAL
AND FAR ERN UPPER MI. MODELS SHOW SBCAPE OF 1000-1500J/KG AHEAD OF
TO JUST BEHIND THE COLD FRONT....WITH 0-6KM BULK SHEAR AROUND 30KTS.
CANNOT RULE OUT POSSIBILITY OF AN ISOLATED SEVERE THREAT FROM
CONVECTION SUN AFTERNOON/EVENING...BUT NOT CONFIDENT ENOUGH TO
MENTION SPECIFICALLY IN HWO. I THINK THE BEST CHANCE FOR SEVERE
THUNDERSTORMS WOULD BE OVER SOUTH CENTRAL UPPER MI AS THE FRONT
INTERACTS WITH LAKE MICHIGAN LAKE BREEZE BOUNDARIES. DID UP POPS FOR
THE PERIOD TO INCLUDE SOME LIKELY POPS...WHICH I WAS COMFORTABLE
DOING GIVEN PWATS AT 200 PERCENT OF NORMAL AND SLOW MOVEMENT OF THE
FRONT THROUGH GOOD INSTABILITY.
SFC HIGH PRESSURE MOVES IN BEHIND THE SFC TROUGH...AND MOVES E OF
THE CWA WED AS AN UPPER RIDGE MOVES OVERHEAD. THIS UPPER RIDGE GETS
SHUNTED E AS A LOW PRESSURE SYSTEM MOVES IN THE NRN PLAINS...BUT
THERE IS A LOT OF DISAGREEMENT BETWEEN MODELS ON THE STRENGTH AND
LOCATION OF THIS SYSTEM. MOST OF THE CWA SHOULD STAY DRY TUE THROUGH
THU...WITH A GENERAL WARMING TREND MON THROUGH THU.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 726 AM EDT FRI MAY 18 2012
A WARM FRONT MAKING ITS WAY ACROSS THE REGION THIS MORNING WILL
CONTINUE TO MOVE NORTH THROUGH THE MORNING...TAKING THE RAIN OVER
THE AREA WITH IT. LLWS WILL END AROUND SUNRISE TODAY. GUSTY SW WINDS
AOA 25 KT WILL DEVELOP TODAY AS MID CLOUDS SCATTER OUT. LOOK FOR
LLWS AGAIN BY FRI EVENING AS DIURNAL MIXING DIMINISHES SFC WIND
SOMEWHAT BUT LOW-LVL JET MAX OF 35 TO 40 KT REMAINS OVER THE AREA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 421 AM EDT FRI MAY 18 2012
WINDS ACROSS LAKE SUPERIOR SHOULD REMAIN BELOW 25KTS THROUGH THE
PERIOD. HIGH PRESSURE ACROSS THE LOWER GREAT LAKES WILL SLOWLY MOVE
TO NEW ENGLAND TODAY INTO SATURDAY. LOW PRESSURE OVER SOUTHERN
SASKATCHEWAN AND THE DAKOTAS WILL PUSH ACROSS THE NORTHERN AND
CENTRAL PLAINS THROUGH SATURDAY...BEFORE SLIDING NORTH INTO ONTARIO
SATURDAY. THIS WILL ALLOW A COLD FRONT TO PUSH ACROSS THE UPPER
GREAT LAKES SUNDAY INTO EARLY MONDAY. BEHIND THE FRONT...HIGH
PRESSURE WILL BUILD IN FROM THE CENTRAL AND NORTHERN PLAINS THROUGH
TUESDAY.
&&
.FIRE WEATHER...
ISSUED AT 421 AM EDT FRI MAY 18 2012
DRY SPELL THIS SPRING IS LEADING TO ANOTHER ACTIVE PERIOD OF FIRE
WX. FIRE WEATHER WATCHES ARE IN EFFECT FOR ALL OF UPR MI. A
PROLONGED PERIOD OF AT LEAST NEAR CRITICAL FIRE WX CONDITIONS IS ON
TAP FOR THIS AFTERNOON THROUGH SAT AFTERNOON.
AXIS OF STRONGER WINDS/LOWEST H95-85 SPECIFIC HUMIDITY LINES UP OVER
THE E THIS AFTN...BUT SW FLOW OFF LK MI PRESENTS A CHALLENGE AS TO
HOW MUCH COOLING/MOISTENING WILL OCCUR RELATED TO THE LAKE
MODERATION. ALTHOUGH MAX TEMPS OVER THE W WILL BE HIER...GRADUAL
ARRIVAL OF MOISTER AIR WILL TEND TO MITIGATE THE DIURNAL FALL OF RH.
CONSIDERING THE SHOWERS THAT FELL OVER MOST OF THE AREA EARLY THIS
MRNG AND EXPECTED MIN RH IN THE 25-30 PERCENT RANGE...OPTED TO ISSUE
A WILDFIRE POTENTIAL STATEMENT IN LIEU OF A RED FLAG WARNING EVEN
THOUGH DEEP MIXING THIS AFTERNOON WILL TRANSPORT STRONGER WINDS TO
THE SFC AT TIMES.
STEADY S WIND TNGT WL LIMIT DIURNAL FALL OF TEMP...EXACERBATING THE
DRYNESS.
ON SAT...ANOTHER DAY WHERE THE AXIS OF DRIEST AIR WILL BE ACROSS ERN
UPR MI. ALTHOUGH DEEP MIXING THAT WILL TAP STRONGER WINDS OFF THE
SFC WOULD ALSO TEND TO LOWER THE MIN RH...FLOW OFF LAKE MI WILL
MODERATE THE FALL OF RH. EXPECTED MIN RH AND POTENTIAL FOR GUSTY
WINDS AFTER A NIGHT OF LIMITED RH RECOVERY JUSTIFIED MAINTAINING THE
GOING FIRE WX WATCH IN THE AFTERNOON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING FOR MIZ001>015-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...TITUS
MARINE...TITUS
FIRE WEATHER...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
727 AM EDT FRI MAY 18 2012
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 421 AM EDT FRI MAY 18 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER CNTRL
NAMERICA BTWN TROFS ALONG THE W COAST AND OVER QUEBEC. ALTHOUGH NO
REAL STRONG SHRTWV IS NOTICEABLE ROUNDING THE TOP OF THE RDG AND
AIRMASS TO THE S IS QUITE DRY PER 00Z MPX RAOB...A CLUSTER OF
SHRA/TS HAS DEVELOPED ON A WNW-ESE AXIS IN AREA OF VIGOROUS H85
THETA-E ADVCTN UNDER AREA OF UPR DVGC INDICATED BY VARIOUS MODELS
AT NOSE OF NOCTURNAL STRENGTHENING H85 SW LLJ BTWN HI PRES OVER LWR
MI AND LO PRES IN ERN NDAKOTA. SPC ANALYSIS INDICATES MUCAPE 500-
1000 J/KG IN THIS AREA NEAR H85 WARM FNT WITH THE STRONG H85 WARMING
SHARPENING LAPSE RATES. EVEN THOUGH THESE STORMS APPEAR TO BE
ELEVATED...SOME OF THEM HAVE CAUSED WIND GUSTS UP TO 30-40 KTS.
FARTHER TO THE S...THE AIRMASS IN THE WARM SECTOR IS VERY WARM AND
DRY. HI TEMPS OVER SW MN ROSE INTO THE LO 90S YDAY WITH DEWPTS AS LO
AS 35 TO 40 UNDER MOSUNNY SKIES. LLVL MSTR AT OMAHA WAS QUITE A BIT
GREATER AT 00Z THAN JUST TO THE N
MAIN FCST CONCERNS IN THE SHORT TERM ARE SHRA/TS CHCS THRU THIS MRNG
AND THEN FIRE WX THIS AFTN/SAT AS WARM AND DRY AIR TO THE S SURGES
INTO THE UPR LKS.
TODAY...EXPECT LINGERING SHRA/TS OVER THE KEWEENAW/NRN TIER IN THE
MRNG TO DRIFT TO THE NE WITH PASSAGE OF H85 WARM FNT UNDER BLDG UPR
RDG TO THE E OF DEEPENING TROF OVER THE W. STEADY SSW FLOW IN THE
WAKE OF THE WARM FROPA IS FCST TO PUSH H85 TEMPS AS HI AS 18C OVER
THE W HALF. MIXING TO H8 ON NAM FCST SDNGS INDICATES HI TEMPS WL
REACH 85 OVER THE W HALF WITH INCRSG SUNSHINE...BUT LOCATIONS
DOWNSTREAM OF LK MI WL BE COOLER. FORTUNATELY FOR FIRE WX
CONCERNS...MODELS ARE IN GOOD AGREEMENT SHOWING HIER LLVL MSTR
RETURNING INTO THE W HALF THRU THE DAY AS THE FLOW TAPS THE GREATER
MSTR SHOWN ON THE OMAHA RAOB AND THE SW WIND DIMINISHING A BIT WITH
ARRIVAL OF WEAKER PRES FALLS TO THE N. AXIS OF DRIER AIR WL REMAIN
OVER THE E HALF...BUT MODERATION OFF LK MI WL HOLD TEMPS DOWN IN
THAT AREA SOMEWHAT. SFC HEATING WL SUPPORT MIXING OF H95-9 WINDS UP
TO 35 KTS...STRONGEST OVER THE E. SEE THE FIRE WX DISCUSSION FOR
MORE DETAILS ON FIRE WX CONCERNS.
TNGT...CWA WL BE IN WARM SECTOR TNGT WITH UPR RDG OVER THE CNTRL GRT
LKS. STEADY SW FLOW/H925 WIND UP TO 35 KTS UNDER SHARP PRES GRADIENT
BTWN HI PRES RETREATING TO THE E AND LO PRES ADVANCING SLOWLY THRU
THE PLAINS WL LIMIT THE DIURNAL FALL OF TEMP DESPITE A MOCLR
SKY...ESPECIALLY ACRS THE DOWNSLOPE AREAS OF THE W AND NCNTRL AS
REFLECTED IN PREVIOUS FCST.
SAT...UPR MI WL REMAIN UNDER THE STEADY SSW FLOW BTWN HI PRES TO THE
E AND LO PRES TROF/COLD FNT ADVANCING THRU MN. WITH HI AMPLITUDE UPR
RDG OVER THE GRT LKS/NE CONUS...PREFER A SLOWER EWD PROGRESSION FOR
THE TROF AS SHOWN BY THE 00Z CNDN MODEL. SO RESTRICTED ANY POPS TO
FAR WRN LK SUP LATE IN THE DAY. MIXING TO H8-75 YIELDS HI TEMPS
APRCHG 90 OVER THE W HALF AWAY FM THE MODERATING INFLUENCE OF LK MI.
THIS DAYTIME MIXING WL ONCE AGAIN TAP H925 WINDS UP TO 35 KTS.
AXIS OF DRIEST AIR REMAINS OVER THE E...BUT FLOW OFF LK MI WL LIKELY
MODERATE MIXING/IMPACT ON SFC DEWPTS.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 421 AM EDT FRI MAY 18 2012
THE PERIOD STARTS 00Z SUN WITH A 500MB RIDGE AXIS JUST E OF THE CWA.
MORE IMPORTANTLY...TO OUR W WILL BE A 500MB TROUGH FROM NRN SASK TO
THE CENTRAL PLAINS STATES. THERE WILL BE A SHORTWAVE TROUGH PUSHING
THROUGH FAR WRN ONTARIO...WITH A 1002MB SFC LOW BENEATH IT. MODELS
SHOW FAIRLY GOOD AGREEMENT ON POSITION OF THESE FEATURES AND WITH
THE POSITION OF A SFC TROUGH/COLD FRONT JUST W OF THE CWA AT 00Z
SUN.
SAT NIGHT THROUGH MON...MODELS SHOW SAME GENERAL IDEA THAT THE
COLD FRONT WILL CROSS THE CWA...PRODUCING PRECIP ACROSS THE
AREA...BUT DIFFER IN TIMING. THE 00Z/18 GFS CONTINUES TO BE A FAST
OUTLIER WITH FROPA. THE 12Z/17 ECMWF CONTINUES TO BE ON THE SLOWER
SIDE...BUT IS CLOSER TO THE MORE MIDDLE GROUND 00Z/18 NAM AND 00Z/18
GEM MODELS THAN THE GFS IS. THE SLOWER SOLUTION IS ALSO SUPPORTED BY
THE FACT THAT THE SYSTEM WILL BE PUSHING INTO THE UPPER
RIDGE...WHICH TYPICALLY RESULTS IN SLOWER MOVEMENT OF THE SYSTEM.
USED A NAM/GEM/ECMWF MIX FOR THIS PART OF THE FORECAST. THIS RESULTS
IN THE FRONT MOVING INTO WRN UPPER MI AROUND 15Z SUN...THEN MOVING
THE CENTRAL UPPER MI AROUND 00Z MON...AND MOVING TO FAR ERN UPPER BY
AROUND 09Z MON. BULK OF MOISTURE...CLOUDS AND PRECIP WILL BE ALONG
AND BEHIND THIS ANAFRONT...ALLOWING FOR PLENTY OF TIME FOR SFC
HEATING AND DESTABILIZATION SUN OVER CENTRAL AND WESTERN UPPER MI.
HIGHS SUN LOOK TO BE IN THE MID TO UPPER 70S OVER CENTRAL AND PARTS
OF WRN UPPER MI...AND EVEN AS HIGH AS THE MID 80S OVER SOUTH CENTRAL
AND FAR ERN UPPER MI. MODELS SHOW SBCAPE OF 1000-1500J/KG AHEAD OF
TO JUST BEHIND THE COLD FRONT....WITH 0-6KM BULK SHEAR AROUND 30KTS.
CANNOT RULE OUT POSSIBILITY OF AN ISOLATED SEVERE THREAT FROM
CONVECTION SUN AFTERNOON/EVENING...BUT NOT CONFIDENT ENOUGH TO
MENTION SPECIFICALLY IN HWO. I THINK THE BEST CHANCE FOR SEVERE
THUNDERSTORMS WOULD BE OVER SOUTH CENTRAL UPPER MI AS THE FRONT
INTERACTS WITH LAKE MICHIGAN LAKE BREEZE BOUNDARIES. DID UP POPS FOR
THE PERIOD TO INCLUDE SOME LIKELY POPS...WHICH I WAS COMFORTABLE
DOING GIVEN PWATS AT 200 PERCENT OF NORMAL AND SLOW MOVEMENT OF THE
FRONT THROUGH GOOD INSTABILITY.
SFC HIGH PRESSURE MOVES IN BEHIND THE SFC TROUGH...AND MOVES E OF
THE CWA WED AS AN UPPER RIDGE MOVES OVERHEAD. THIS UPPER RIDGE GETS
SHUNTED E AS A LOW PRESSURE SYSTEM MOVES IN THE NRN PLAINS...BUT
THERE IS A LOT OF DISAGREEMENT BETWEEN MODELS ON THE STRENGTH AND
LOCATION OF THIS SYSTEM. MOST OF THE CWA SHOULD STAY DRY TUE THROUGH
THU...WITH A GENERAL WARMING TREND MON THROUGH THU.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 726 AM EDT FRI MAY 18 2012
A WARM FRONT MAKING ITS WAY ACROSS THE REGION THIS MORNING WILL
CONTINUE TO MOVE NORTH THROUGH THE MORNING...TAKING THE RAIN OVER
THE AREA WITH IT. LLWS WILL END AROUND SUNRISE TODAY. GUSTY SW WINDS
AOA 25 KT WILL DEVELOP TODAY AS MID CLOUDS SCATTER OUT. LOOK FOR
LLWS AGAIN BY FRI EVENING AS DIURNAL MIXING DIMINISHES SFC WIND
SOMEWHAT BUT LOW-LVL JET MAX OF 35 TO 40 KT REMAINS OVER THE AREA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 421 AM EDT FRI MAY 18 2012
WINDS ACROSS LAKE SUPERIOR SHOULD REMAIN BELOW 25KTS THROUGH THE
PERIOD. HIGH PRESSURE ACROSS THE LOWER GREAT LAKES WILL SLOWLY MOVE
TO NEW ENGLAND TODAY INTO SATURDAY. LOW PRESSURE OVER SOUTHERN
SASKATCHEWAN AND THE DAKOTAS WILL PUSH ACROSS THE NORTHERN AND
CENTRAL PLAINS THROUGH SATURDAY...BEFORE SLIDING NORTH INTO ONTARIO
SATURDAY. THIS WILL ALLOW A COLD FRONT TO PUSH ACROSS THE UPPER
GREAT LAKES SUNDAY INTO EARLY MONDAY. BEHIND THE FRONT...HIGH
PRESSURE WILL BUILD IN FROM THE CENTRAL AND NORTHERN PLAINS THROUGH
TUESDAY.
&&
.FIRE WEATHER...
ISSUED AT 421 AM EDT FRI MAY 18 2012
DRY SPELL THIS SPRING IS LEADING TO ANOTHER ACTIVE PERIOD OF FIRE
WX. FIRE WEATHER WATCHES ARE IN EFFECT FOR ALL OF UPR MI. A
PROLONGED PERIOD OF AT LEAST NEAR CRITICAL FIRE WX CONDITIONS IS ON
TAP FOR THIS AFTERNOON THROUGH SAT AFTERNOON.
AXIS OF STRONGER WINDS/LOWEST H95-85 SPECIFIC HUMIDITY LINES UP OVER
THE E THIS AFTN...BUT SW FLOW OFF LK MI PRESENTS A CHALLENGE AS TO
HOW MUCH COOLING/MOISTENING WILL OCCUR RELATED TO THE LAKE
MODERATION. ALTHOUGH MAX TEMPS OVER THE W WILL BE HIER...GRADUAL
ARRIVAL OF MOISTER AIR WILL TEND TO MITIGATE THE DIURNAL FALL OF RH.
CONSIDERING THE SHOWERS THAT FELL OVER MOST OF THE AREA EARLY THIS
MRNG AND EXPECTED MIN RH IN THE 25-30 PERCENT RANGE...OPTED TO ISSUE
A WILDFIRE POTENTIAL STATEMENT IN LIEU OF A RED FLAG WARNING EVEN
THOUGH DEEP MIXING THIS AFTERNOON WILL TRANSPORT STRONGER WINDS TO
THE SFC AT TIMES.
STEADY S WIND TNGT WL LIMIT DIURNAL FALL OF TEMP...EXACERBATING THE
DRYNESS.
ON SAT...ANOTHER DAY WHERE THE AXIS OF DRIEST AIR WILL BE ACROSS ERN
UPR MI. ALTHOUGH DEEP MIXING THAT WILL TAP STRONGER WINDS OFF THE
SFC WOULD ALSO TEND TO LOWER THE MIN RH...FLOW OFF LAKE MI WILL
MODERATE THE FALL OF RH. EXPECTED MIN RH AND POTENTIAL FOR GUSTY
WINDS AFTER A NIGHT OF LIMITED RH RECOVERY JUSTIFIED MAINTAINING THE
GOING FIRE WX WATCH IN THE AFTERNOON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING FOR MIZ001>015-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...TITUS
MARINE...TITUS
FIRE WEATHER...KC
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
949 AM MDT FRI MAY 18 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY...
RAIN SHOWERS THIS MORNING DIMINISHING OVER SOME LOCATIONS AND
PERSISTING AND EVEN INCREASING OVER OTHERS. UPDATED THE FORECAST
TODAY TO REFLECT THE MORE ACCURATE HRRR DEPICTION OF EXPECTED
PRECIPITATION WHICH INCREASES OVER OUR SOUTHEASTERN ZONES THIS
AFTERNOON. ALSO INCLUDED A SLIVER OF THUNDERSTORM MENTION OVER OUR
FAR EASTERN ZONES TO SUPPORT SPC OUTLOOK FOR GENERAL THUNDERSTORMS
THIS AFTERNOON. BMICKELSON
PREVIOUS SHORT TERM DISCUSSION...BROAD AREA OF RAIN LIFTING
ACROSS NORTHEAST MONTANA EARLY THIS MORNING. HEAVIEST RAINFALL
LOOKS TO BE ASSOCIATED WITH FORCING ALONG THE 700MB FRONT AS IT
MOVES INTO THE WESTERN ZONES...AND PUSHED NORTH BY SHORTWAVE
LIFTING ACROSS SOUTH CENTRAL MONTANA. AS UPPER TROF CONTINUES TO
PUSH THROUGH THE GREAT BASIN...MOISTURE STREAMING NORTH COULD
RESULT IN ADDITIONAL SHOWERS ACROSS EASTERN MONTANA TODAY.
UPPER TROF AXIS SWINGS ACROSS MONTANA OVERNIGHT BRINGING THE
THREAT OF SHOWERS TO AN END. SATURDAY WILL BE DRY BUT COOL WITH
HIGH PRESSURE OVER THE STATE AND WEAK CYCLONIC FLOW. UPPER RIDGE
BEGINS TO REBOUND OVER THE NORTHERN ROCKIES ON SUNDAY AND HIGH
PRESSURE MOVING EAST WILL ALLOW FOR RETURN FLOW PUSHING WARMER AIR
INTO THE STATE. EBERT
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
THE EXTENDED PERIOD BEGINS SUNDAY NIGHT WITH ZONAL FLOW ALOFT THAT
WILL BECOME A NARROW WAVE UPPER RIDGE ON MONDAY. THIS RIDGING WILL
INCREASE THICKNESS HEIGHTS AND BEGIN A WARM-UP MONDAY...POSSIBLY
LASTING THROUGH TUESDAY.
MONDAY AFTERNOON AND EVENING A WEAK COLD FRONT FROM AN UPPER
TROUGH DIGGING INTO THE PAC-NW WILL MOVE INTO MONTANA. THIS FRONT
WILL INCREASE INSTABILITY...MAINLY OVER CENTRAL MONTANA. HOWEVER
SOME THUNDERSTORMS COULD DRIFT INTO NORTHEAST MONTANA. THEN ON
TUESDAY THE TROUGH SWINGS ACROSS THE NORTHERN ROCKIES SENDING
ANOTHER STRONGER COLD FRONT INTO THE NORTHERN HIGH PLAINS. THERE
ARE INDICATIONS OF EVEN GREATER INSTABILITY ON TUESDAY AND TUESDAY
EVENING...FOR THE POSSIBILITY OF SEVERAL SEVERE THUNDERSTORMS THAT
COULD MOVE INTO WESTERN NORTH DAKOTA FROM NE MONTANA.
THE GFS AND EC DISAGREE ON HOW THE TROUGH DEVELOPS. BUT BOTH SEEM
TO AGREE WITH THE TROUGH BECOMING MORE OF A LONG WAVE AND
REMAINING OVER THE REGION THROUGH THE REST OF THE EXTENDED
PERIOD...TRENDING TEMPERATURES TO BELOW AVERAGE BY THURSDAY AND
FRIDAY. THE PERIOD WILL ALSO LIKELY SEE CONTINUING PERIODS OF
SHOWER ACTIVITY. THE GFS CLOSES OFF THE LOW AND STACKS UP OVER
WESTERN NORTH DAKOTA WEDNESDAY NIGHT...WHICH TENDS TO RETROGRADE
PRECIPITATION BACK INTO NEMONT. THIS WOULD ALSO DEVELOP STRONG
WINDS. THE EC ON THE OTHER HAND LIFTS THE CLOSED UPPER LOW INTO
SOUTHERN ALBERTA AND SASKATCHEWAN. THEREFORE MODEL UNCERTAINTY
WILL MAKE POPS AND QPF AMOUNTS DIFFICULT TO FORECAST. HOWEVER THE
REST OF THE EXTENDED PERIOD SHOULD HAVE SHOWERS OR RAIN WITH THE
COOLER TEMPERATURES. SCT
&&
.AVIATION...
VFR WITH ANY MVFR CONDITIONS TO THE NORTH OF THE TAF SITES
EVAPORATING TODAY. SOME CEILINGS OF 4K TO 7K ARE EXPECTED AT MOST
SITES TODAY THAT WILL LIFT THIS EVENING. ISOLATED SHOWERS ARE POSSIBLE.
WINDS WILL BECOME NW FROM WEST TO EAST THIS AFTERNOON AT 10 TO 15
KTS. JAMBA
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1022 AM EDT FRI MAY 18 2012
.SYNOPSIS...
A HIGH PRESSURE RIDGE WILL BE ACROSS THE AREA THROUGH THE
WEEKEND. A WEAK COLD FRONT WILL MOVE ACROSS THE REGION MONDAY.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
12Z SOUNDINGS SHOW A SHARP SURFACE INVERSION AGAIN THIS MORNING
WITH VERY DRY LOW LEVEL CONDITIONS. THE DTX SOUNDING SHOWS THE MID
LEVEL MOISTURE FROM 600-700 MB WHICH AGREES WELL WITH THE PATCHY
MID LEVEL CLOUDS THAT ARE ERODING AS THEY MOVE SOUTHEAST TOWARD LAKE
ERIE. THE MORNING SOUNDINGS SUPPORT WARMER TEMPERATURES THAN
CURRENTLY FORECAST ESPECIALLY AWAY FROM LAKE ERIE SO WILL RAISE
READINGS TO NEAR THE HRRR MODEL WHERE HIGHS WILL REACH INTO THE
LOWER 80S. SINCE CLOUDS ARE ERODING AS THE MOVE SOUTHEAST...WILL
LESSEN FORECAST CLOUD COVER FOR THE AFTERNOON AND GO WITH SUNNY TO
MOSTLY SUNNY.
&&
.SHORT TERM /9 PM THIS EVENING THROUGH MONDAY NIGHT/...
HIGH PRESSURE AND DRY AIR REMAIN IN PLACE THROUGH THE WEEKEND WITH
TEMPS WARMING INTO THE LOWER AND MID 80S SATURDAY AND SUNDAY.
MONDAY A WEAK COLD FRONT WILL MOVE THROUGH THE AREA. WILL BRING IN
LOW CHANCE POPS FROM THE WEST SUNDAY NIGHT. MONDAY WILL HAVE LOW
CHANCE POPS WEST HALF AND SLIGHT CHANCE EAST...RAISING TO CHANCE
EVERYWHERE TUESDAY. GFS SHOWS WEAK LOW PRESSURE ACROSS CENTRAL
OHIO IN A...BY THEN...FAIRLY MOIST ENVIRONMENT. TEMPS STILL ABOVE
NORMAL ALTHOUGH DOWN A FEW DEGREES FROM THE WEEKEND.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
FAIRLY BROAD DISORGANIZED UPPER LEVEL TROUGH WILL PERSIST OVER THE
AREA TUESDAY AND WEDNESDAY AND THEN FINALLY EJECT OUT TO THE EAST
COAST BY NEXT THURSDAY. MEANWHILE...UPPER LEVEL RIDGE BUILDS EAST
OVER THE LOCAL REGION FOR THE END OF THE WEEK.
WEAK SURFACE LOW PRESSURE IS RATHER SLUGGISH IN ITS FORWARD MOTION
MOVING EAST OUT OF THE AREA. MOISTURE ASSOCIATED WITH THE LOW
PRESSURE SYSTEM WILL LINGER IN THE AREA AS WELL TUESDAY AND
WEDNESDAY.
WEAK HIGH PRESSURE AT THE SURFACE BUILDS IN OVER THE AREA WEDNESDAY
AFTERNOON INTO THURSDAY. WARM FRONT LIFTS WELL NORTH BY THURSDAY
AFTERNOON PLACING THE AREA INTO THE WARM SECTOR. MODELS ARE REALLY
HINTING AT SUMMER RETURNING TO THE FORECAST AREA AS WE APPROACH THE
WEEKEND. EXPECTING VALUES AROUND 570 AT 1000 TO 500 MB THICKNESS BY
THURSDAY AFTERNOON. SOUTH FLOW WILL ALSO DEVELOP IN THE WAKE OF THE
WARM FRONT AND THIS SHOULD ORIGINATE RIGHT OUT OF THE DEEP SOUTH.
LONG RANGE MODELS SEEM TO BE IN AGREEMENT WITH THIS SCENARIO AS IT
UNFOLDS.
DROPPED BACK TEMPERATURES A FEW DEGREES TUESDAY DUE TO SHOWER THREAT
BUT BOOSTED THEM A COUPLE WEDNESDAY INTO THURSDAY AS SHOWERS BEGIN
TO EXIT THE AREA.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
MID LEVEL CLOUDS COMING ACROSS THE LAKE FROM THE NORTHEAST ARE
DISSIPATING AS THEY ARE ENTERING DRIER AIR. THE REGION REMAINS UNDER
THE INFLUENCE OF HIGH PRESSURE WHICH IS INHIBITING CLOUD GROWTH.
LAKE BREEZE EXPECTED TO DEVELOP AT ERIE AND CLEVELAND DURING THE DAY
AND THEN LAND BREEZE SETS UP. WINDS SHOULD REMAIN BELOW 10 KNOTS.
.OUTLOOK...NON-VFR CONDITIONS MAY DEVELOP NEAR THUNDERSTORMS MONDAY
AND TUESDAY.
&&
.MARINE...
RELATIVELY QUIET ON THE LAKE THROUGH THE NEXT 5 DAYS. GENERALLY
LOOKING AT WAVES OF 2 FEET OR LESS. STAGNANT LIGHT OR WEAK FLOW WILL
PERSIST THROUGH THE PERIOD.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...REL
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...SJ/LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
932 AM EDT FRI MAY 18 2012
.SYNOPSIS...
A HIGH PRESSURE RIDGE WILL BE ACROSS THE AREA THROUGH THE
WEEKEND. A WEAK COLD FRONT WILL MOVE ACROSS THE REGION MONDAY.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
12Z SOUNDINGS SHOW A SHARP SURFACE INVERSION AGAIN THIS MORNING
WITH VERY DRY LOW LEVEL CONDITIONS. THE DTX SOUNDING SHOWS THE MID
LEVEL MOISTURE FROM 600-700 MB WHICH AGREES WELL WITH THE PATCHY
MID LEVEL CLOUDS THAT ARE ERODING AS THEY MOVE SOUTHEAST TOWARD LAKE
ERIE. THE MORNING SOUNDINGS SUPPORT WARMER TEMPERATURES THAN
CURRENTLY FORECAST ESPECIALLY AWAY FROM LAKE ERIE SO WILL RAISE
READINGS TO NEAR THE HRRR MODEL WHERE HIGHS WILL REACH INTO THE
LOWER 80S. SINCE CLOUDS ARE ERODING AS THE MOVE SOUTHEAST...WILL
LESSEN FORECAST CLOUD COVER FOR THE AFTERNOON AND GO WITH SUNNY TO
MOSTLY SUNNY.
&&
.SHORT TERM /9 PM THIS EVENING THROUGH MONDAY NIGHT/...
HIGH PRESSURE AND DRY AIR REMAIN IN PLACE THROUGH THE WEEKEND WITH
TEMPS WARMING INTO THE LOWER AND MID 80S SATURDAY AND SUNDAY.
MONDAY A WEAK COLD FRONT WILL MOVE THROUGH THE AREA. WILL BRING IN
LOW CHANCE POPS FROM THE WEST SUNDAY NIGHT. MONDAY WILL HAVE LOW
CHANCE POPS WEST HALF AND SLIGHT CHANCE EAST...RAISING TO CHANCE
EVERYWHERE TUESDAY. GFS SHOWS WEAK LOW PRESSURE ACROSS CENTRAL
OHIO IN A...BY THEN...FAIRLY MOIST ENVIRONMENT. TEMPS STILL ABOVE
NORMAL ALTHOUGH DOWN A FEW DEGREES FROM THE WEEKEND.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
FAIRLY BROAD DISORGANIZED UPPER LEVEL TROUGH WILL PERSIST OVER THE
AREA TUESDAY AND WEDNESDAY AND THEN FINALLY EJECT OUT TO THE EAST
COAST BY NEXT THURSDAY. MEANWHILE...UPPER LEVEL RIDGE BUILDS EAST
OVER THE LOCAL REGION FOR THE END OF THE WEEK.
WEAK SURFACE LOW PRESSURE IS RATHER SLUGGISH IN ITS FORWARD MOTION
MOVING EAST OUT OF THE AREA. MOISTURE ASSOCIATED WITH THE LOW
PRESSURE SYSTEM WILL LINGER IN THE AREA AS WELL TUESDAY AND
WEDNESDAY.
WEAK HIGH PRESSURE AT THE SURFACE BUILDS IN OVER THE AREA WEDNESDAY
AFTERNOON INTO THURSDAY. WARM FRONT LIFTS WELL NORTH BY THURSDAY
AFTERNOON PLACING THE AREA INTO THE WARM SECTOR. MODELS ARE REALLY
HINTING AT SUMMER RETURNING TO THE FORECAST AREA AS WE APPROACH THE
WEEKEND. EXPECTING VALUES AROUND 570 AT 1000 TO 500 MB THICKNESS BY
THURSDAY AFTERNOON. SOUTH FLOW WILL ALSO DEVELOP IN THE WAKE OF THE
WARM FRONT AND THIS SHOULD ORIGINATE RIGHT OUT OF THE DEEP SOUTH.
LONG RANGE MODELS SEEM TO BE IN AGREEMENT WITH THIS SCENARIO AS IT
UNFOLDS.
DROPPED BACK TEMPERATURES A FEW DEGREES TUESDAY DUE TO SHOWER THREAT
BUT BOOSTED THEM A COUPLE WEDNESDAY INTO THURSDAY AS SHOWERS BEGIN
TO EXIT THE AREA.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
MID LEVEL DECK DEVELOPED DURING THE NIGHT OVER NORTHERN LOWER
MICHIGAN AND IS HEADED TOWARD ERIE. SHOULD SEE THIS DECK FOR THE
MORNING HOURS UNTIL SOME MID LEVEL DRYING TAKES PLACE TO DISSIPATE
THE CLOUDS. OTHERWISE...HIGH LEVEL SCATTERED CIRRUS WILL AFFECT
THE REGION TODAY AS REGION REMAINS UNDER THE INFLUENCE OF HIGH
PRESSURE. LAKE BREEZE EXPECTED TO DEVELOP AT ERIE AND CLEVELAND
DURING THE DAY AND THEN LAND BREEZE SETS UP. WINDS SHOULD REMAIN
BELOW 10 KNOTS.
.OUTLOOK...NON-VFR CONDITIONS MAY DEVELOP NEAR THUNDERSTORMS MONDAY
AND TUESDAY.
&&
.MARINE...
RELATIVELY QUIET ON THE LAKE THROUGH THE NEXT 5 DAYS. GENERALLY
LOOKING AT WAVES OF 2 FEET OR LESS. STAGNANT LIGHT OR WEAK FLOW WILL
PERSIST THROUGH THE PERIOD.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...REL
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1129 AM MDT FRI MAY 18 2012
.UPDATE...
ISSUED AT 1117 AM MDT FRI MAY 18 2012
CONVECTION QUICKLY FIRING THIS MORNING ACROSS NORTHEAST UTAH AND
ACTIVITY IS DEVELOPING IN STRONGLY INVERTED-V ENVIRONMENT BASED ON
MORNING SOUNDINGS. STRONG OUTFLOW WINDS WILL BE OUR BIGGEST
CONCERN FROM THESE STORMS AS WE AWAIT THE ARRIVAL OF THE COLD
FRONT AND ITS ASSOCIATED SHORTWAVE TROUGH PUSHING ACROSS UTAH.
LATEST WATER VAPOR IMAGERY SHOWING SOME DRIER AIR MOVING INTO THE
SOUTHERN ZONES...BUT BEST DRY PUNCH WILL REMAIN WELL SOUTH OF THE
FORECAST AREA. CLOUD COVER HAS BEEN SLOW TO ERODE THIS MORNING
AND CU FIELDS QUICKLY POPPING IN CLEAR AREAS...SO BEST HEATING MAY
NOT BE REALIZED TODAY...WHICH WILL HINDER OUR STRONGER CONVECTION
A BIT. IN ANY CASE...THE AFTERNOON AND EVENINGS HOURS WILL BE
RATHER ACTIVE AND FORECASTS HAVE BEEN UPDATED TO ACCOUNT FOR THE
LATEST TRENDS. LOOKS LIKE THE FRONT WILL ARRIVE AFTER 4 PM AND
PASS THROUGH THE ENTIRE FORECAST AREA BY MID EVENING.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 411 AM MDT FRI MAY 18 2012
TODAY...CRITICAL FIRE WEATHER CONDITIONS WILL DEVELOP OVER MUCH OF
THE FORECAST AREA BEGINNING LATE THIS MORNING AND CONTINUING INTO
THIS EVENING. A PACIFIC TROUGH AND COLD FRONT WILL MOVE ACROSS
THE AREA TODAY. THE SHORT-TERM MODELS ARE CAPTURING THE CURRENT
SITUATION FAIRLY WELL AND IN GOOD AGREEMENT. SATELLITE AND SURFACE
ANALYSIS SHOW THE FRONT OVER EXTREME WESTERN UT EARLY THIS MORNING.
PREFRONTAL...WARM ADVECTION RELATED MID CLOUDS WILL CONTINUE
FLOWING OVER THE FORECAST AREA THIS MORNING. THE LOWEST CLOUD
BASES DETECTED OVER THE CWA HAS BEEN 11K FT SO FAR...SO LITTLE OR
NO PRECIP REACHING THE GROUND FROM THESE CLOUDS.
THE RUC SHOWS THE FRONT JUST ENTERING THE EASTERN UT PORTION OF THE
CWA ABOUT NOON. THE FRONT SHOULD REACH THE CO/UT BORDER AROUND
00Z... SO MOST OF TODAY SHOULD BE PREFRONTAL WITH STRONG SW WINDS
AND WARM AND DRY CONDITIONS. HAVE CONTINUED THE RED FLAG WARNING
FOR MOST OF WESTERN CO...BUT CANCELLED THE PORTION IN ROUTT COUNTY
AND THE FLATTOPS AS BELIEVE THE RH WILL NOT LOWER ENOUGH.
UPPER TROUGH WILL BE MOVING ACROSS OUR CWA TONIGHT AND LATEST
MODELS HAVE FOLLOWED TREND OF PREVIOUS RUNS WITH MUCH SIMILARITY.
CONFIDENCE RATHER HIGH ON THE TIMING..INTENSITY...AND MOISTURE
CONTENT FOR OUR CWA. THEREFORE...SIGNIFICANTLY BOOSTED POPS
OVERNIGHT THROUGHOUT THE NORTHERN AND MOST CENTRAL ZONES OF
WESTERN COLORADO. FOR NW COLORADO MOUNTAIN ZONES RAISED THEM FROM
SLIGHT CHANCE TO LIKELY CATEGORIES FROM MIDNIGHT THROUGH SUNRISE.
EXPECT THOSE ZONES TO GENERALLY RECEIVE 0.15 TO 0.25 OF AN INCH OF
WATER.
ALTHOUGH MOISTURE SHOULD GRADUALLY DECREASE FROM THE WEST ACROSS OUR
CWA ON SATURDAY AS THE UPPER TROUGH MOVES EAST...EXPECT SOME
LINGERING SHOWERS MAINLY ON UPWIND SIDE OF THE NORTHERN AND CENTRAL
MOUNTAINS OF WESTERN COLORADO. SHOULD BE MUCH COOLER THROUGHOUT OUR
CWA ON SATURDAY...WITH THICKNESS VALUES EXPECTED TO DROP ABOUT
90-100 METERS FROM FRIDAY...RESULTING IN MAX TEMPERATURES ON
SATURDAY GENERALLY 5 TO 10 DEGREES COOLER THAN FRIDAY.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 411 AM MDT FRI MAY 18 2012
MIGRATORY UPPER RIDGE MOVES INTO OUR AREA BY SUNDAY WITH MUCH DRIER
AIR FOR OUR REGION. WARM AIR ADVECTION LIKELY TO RESULT IN MAX
TEMPERATURES 5 TO 10 DEGREES WARMER THAN SATURDAY THROUGHOUT OUR CWA.
THE RIDGELINE WILL PASS EAST OF THE AREA MONDAY WITH INCREASING SW
FLOW ALOFT THEREAFTER AS THE NEXT PACIFIC TROUGH MOVES ONSHORE.
THIS TROUGH IS EXPECTED TO BEGIN AFFECTING NORTHERN UT TUE THEN
PUSH THROUGH THE FORECAST AREA TUE NIGHT. THE MAIN JET AXIS IS
PROGGED TO REMAIN OVER THE AREA TUE THROUGH FRI. A SERIES OF
MODERATE PACIFIC SYSTEM WILL MOVE THROUGH DURING THE WEEK
BEGINNING TUE NIGHT AND WED...THEN AGAIN WED NIGHT AND THU.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1049 AM MDT FRI MAY 18 2012
THE FIRST WAVE OF CLOUD AND ISOLATED SHOWERS/VIRGA IS PASSING OVER
THE COLORADO MOUNTAINS LATE THIS MORNING. THE MAIN THREAT WILL BE
SHIFTING AND GUSTY WINDS NEAR THE SHOWERS...OTHERWISE THE STRONGER
WESTERLY FLOW ALOFT SHOULD MIX DOWN TO THE VALLEYS WITH CLEARING
EARLY THIS AFTERNOON. THIS ADDED SUNSHINE AND APPROACHING FRONT
WILL LEAD TO AN INCREASE IN CONVECTION THIS LATE THIS AFTERNOON
AND EVENING. VFR CONDITIONS SHOULD STILL PREVAIL AT THE AREA
TERMINALS...BUT PASSING SHOWERS OR STORMS WILL BE CAPABLE OF
STRONG...ERRATIC WIND GUSTS. MVFR CONDITIONS AND LOCAL MOUNTAIN
OBSCURATIONS WILL BE POSSIBLE AS THE CONVECTION ORGANIZES THIS
AFTERNOON. IMPROVING CONDITIONS ARE EXPECTED OVERNIGHT AS THE COLD
FRONT AND UPPER SUPPORT SHIFT EAST OF THE MOUNTAINS.
&&
.FIRE WEATHER...
ISSUED AT 411 AM MDT FRI MAY 18 2012
WITH THE TROUGH AND COLD FRONT TODAY AND THIS EVENING...STRONG
SOUTHWEST WINDS WILL MIX TO THE SURFACE BY MID AND LATE MORNING.
RELATIVE HUMIDITIES AT 15% OR LESS WILL BECOME WIDESPREAD LATE THIS
MORNING AS WELL. HAVE CONTINUED THE RED FLAG WARNING FOR MOST OF
THE AREA...BUT HAVE CANCELLED THE PORTION OF THE WARNING IN ZONE
201...ROUTT COUNTY AND PORTIONS OF THE FLAT TOPS...AS THE HUMIDITY
DOESN`T SEEM TO GET LOW ENOUGH. AS THE FRONT MOVES THROUGH...
SURFACE WINDS SHOULD SHIFT ABRUPTLY TO THE NORTHWEST.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...RED FLAG WARNING UNTIL 10 PM MDT THIS EVENING FOR COZ203-207-290-
292-293.
UT...NONE.
&&
$$
UPDATE...JDC
SHORT TERM...CC/JP
LONG TERM...JP/CC
AVIATION...15
FIRE WEATHER...CC
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1049 AM MDT FRI MAY 18 2012
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 411 AM MDT FRI MAY 18 2012
TODAY...CRITICAL FIRE WEATHER CONDITIONS WILL DEVELOP OVER MUCH OF
THE FORECAST AREA BEGINNING LATE THIS MORNING AND CONTINUING INTO
THIS EVENING. A PACIFIC TROUGH AND COLD FRONT WILL MOVE ACROSS
THE AREA TODAY. THE SHORT-TERM MODELS ARE CAPTURING THE CURRENT
SITUATION FAIRLY WELL AND IN GOOD AGREEMENT. SATELLITE AND SURFACE
ANALYSIS SHOW THE FRONT OVER EXTREME WESTERN UT EARLY THIS MORNING.
PREFRONTAL...WARM ADVECTION RELATED MID CLOUDS WILL CONTINUE
FLOWING OVER THE FORECAST AREA THIS MORNING. THE LOWEST CLOUD
BASES DETECTED OVER THE CWA HAS BEEN 11K FT SO FAR...SO LITTLE OR
NO PRECIP REACHING THE GROUND FROM THESE CLOUDS.
THE RUC SHOWS THE FRONT JUST ENTERING THE EASTERN UT PORTION OF THE
CWA ABOUT NOON. THE FRONT SHOULD REACH THE CO/UT BORDER AROUND
00Z... SO MOST OF TODAY SHOULD BE PREFRONTAL WITH STRONG SW WINDS
AND WARM AND DRY CONDITIONS. HAVE CONTINUED THE RED FLAG WARNING
FOR MOST OF WESTERN CO...BUT CANCELLED THE PORTION IN ROUTT COUNTY
AND THE FLATTOPS AS BELIEVE THE RH WILL NOT LOWER ENOUGH.
UPPER TROUGH WILL BE MOVING ACROSS OUR CWA TONIGHT AND LATEST
MODELS HAVE FOLLOWED TREND OF PREVIOUS RUNS WITH MUCH SIMILARITY.
CONFIDENCE RATHER HIGH ON THE TIMING..INTENSITY...AND MOISTURE
CONTENT FOR OUR CWA. THEREFORE...SIGNIFICANTLY BOOSTED POPS
OVERNIGHT THROUGHOUT THE NORTHERN AND MOST CENTRAL ZONES OF
WESTERN COLORADO. FOR NW COLORADO MOUNTAIN ZONES RAISED THEM FROM
SLIGHT CHANCE TO LIKELY CATEGORIES FROM MIDNIGHT THROUGH SUNRISE.
EXPECT THOSE ZONES TO GENERALLY RECEIVE 0.15 TO 0.25 OF AN INCH OF
WATER.
ALTHOUGH MOISTURE SHOULD GRADUALLY DECREASE FROM THE WEST ACROSS OUR
CWA ON SATURDAY AS THE UPPER TROUGH MOVES EAST...EXPECT SOME
LINGERING SHOWERS MAINLY ON UPWIND SIDE OF THE NORTHERN AND CENTRAL
MOUNTAINS OF WESTERN COLORADO. SHOULD BE MUCH COOLER THROUGHOUT OUR
CWA ON SATURDAY...WITH THICKNESS VALUES EXPECTED TO DROP ABOUT
90-100 METERS FROM FRIDAY...RESULTING IN MAX TEMPERATURES ON
SATURDAY GENERALLY 5 TO 10 DEGREES COOLER THAN FRIDAY.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 411 AM MDT FRI MAY 18 2012
MIGRATORY UPPER RIDGE MOVES INTO OUR AREA BY SUNDAY WITH MUCH DRIER
AIR FOR OUR REGION. WARM AIR ADVECTION LIKELY TO RESULT IN MAX
TEMPERATURES 5 TO 10 DEGREES WARMER THAN SATURDAY THROUGHOUT OUR CWA.
THE RIDGELINE WILL PASS EAST OF THE AREA MONDAY WITH INCREASING SW
FLOW ALOFT THEREAFTER AS THE NEXT PACIFIC TROUGH MOVES ONSHORE.
THIS TROUGH IS EXPECTED TO BEGIN AFFECTING NORTHERN UT TUE THEN
PUSH THROUGH THE FORECAST AREA TUE NIGHT. THE MAIN JET AXIS IS
PROGGED TO REMAIN OVER THE AREA TUE THROUGH FRI. A SERIES OF
MODERATE PACIFIC SYSTEM WILL MOVE THROUGH DURING THE WEEK
BEGINNING TUE NIGHT AND WED...THEN AGAIN WED NIGHT AND THU.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1049 AM MDT FRI MAY 18 2012
THE FIRST WAVE OF CLOUD AND ISOLATED SHOWERS/VIRGA IS PASSING OVER
THE COLORADO MOUNTAINS LATE THIS MORNING. THE MAIN THREAT WILL BE
SHIFTING AND GUSTY WINDS NEAR THE SHOWERS...OTHERWISE THE STRONGER
WESTERLY FLOW ALOFT SHOULD MIX DOWN TO THE VALLEYS WITH CLEARING
EARLY THIS AFTERNOON. THIS ADDED SUNSHINE AND APPROACHING FRONT
WILL LEAD TO AN INCREASE IN CONVECTION THIS LATE THIS AFTERNOON
AND EVENING. VFR CONDITIONS SHOULD STILL PREVAIL AT THE AREA
TERMINALS...BUT PASSING SHOWERS OR STORMS WILL BE CAPABLE OF
STRONG...ERRATIC WIND GUSTS. MVFR CONDITIONS AND LOCAL MOUNTAIN
OBSCURATIONS WILL BE POSSIBLE AS THE CONVECTION ORGANIZES THIS
AFTERNOON. IMPROVING CONDITIONS ARE EXPECTED OVERNIGHT AS THE COLD
FRONT AND UPPER SUPPORT SHIFT EAST OF THE MOUNTAINS.
&&
.FIRE WEATHER...
ISSUED AT 411 AM MDT FRI MAY 18 2012
WITH THE TROUGH AND COLD FRONT TODAY AND THIS EVENING...STRONG
SOUTHWEST WINDS WILL MIX TO THE SURFACE BY MID AND LATE MORNING.
RELATIVE HUMIDITIES AT 15% OR LESS WILL BECOME WIDESPREAD LATE THIS
MORNING AS WELL. HAVE CONTINUED THE RED FLAG WARNING FOR MOST OF
THE AREA...BUT HAVE CANCELLED THE PORTION OF THE WARNING IN ZONE
201...ROUTT COUNTY AND PORTIONS OF THE FLAT TOPS...AS THE HUMIDITY
DOESN`T SEEM TO GET LOW ENOUGH. AS THE FRONT MOVES THROUGH...
SURFACE WINDS SHOULD SHIFT ABRUPTLY TO THE NORTHWEST.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...RED FLAG WARNING UNTIL 10 PM MDT THIS EVENING FOR COZ203-207-290-
292-293.
UT...NONE.
&&
$$
SHORT TERM...CC/JP
LONG TERM...JP/CC
AVIATION...15
FIRE WEATHER...CC
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
639 PM EDT FRI MAY 18 2012
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FOR DRY WEATHER WITH A WARMING TREND
CONTINUING THROUGH THE WEEKEND. THE CHANCE OF SHOWERS AND
THUNDERSTORMS WILL RETURN ON MONDAY AS A FRONTAL BOUNDARY
APPROACHES FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
MINOR CHANGES TO PREVIOUS FORECAST, REMOVED CLOUDS IN THE SOUTH
AND ADJUSTED HOURLY TEMPS.
PREVIOUS DISCUSSION...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE AXIS
EXTENDING FROM THE ARKLATEX REGION INTO THE LOWER GREAT LAKES. AT
THE SURFACE, A 1025MB HIGH IS CENTERED ACROSS NEW ENGLAND AND
EXTENDS SOUTHWESTWARD INTO THE UPPER OHIO VALLEY. MEANWHILE, A
CLOSED LOW IS DEVELOPING OFF THE CAROLINA COAST.
THE 500MB RIDGE WILL BUILD IN FURTHER INTO THE GREAT LAKES REGION
TODAY AND TONIGHT WITH WEAK ANTI-CYCLONIC FLOW ALOFT CENTERED ACROSS
NORTHERN OHIO BY 12Z SATURDAY. THIS WILL ALLOW ABUNDANT SUNSHINE TO
CONTINUE INTO THE EVENING. WITH NEAR CALM WINDS AND CLEAR SKIES
TONIGHT, RADIATIONAL COOLING WILL ALLOW FOR TEMPERATURES TO
STEADILY DROP OFF. OVERNIGHT LOWS WILL RANGE FROM THE LOWER 40S
ACROSS THE I-80 CORRIDOR AND EASTERN RIDGES TO THE LOWER 50S
ACROSS PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL WV. WITH SUPPORT
FROM THE LAMP, PATCHY RADIATION FOG IS FORECAST TO DEVELOP
OVERNIGHT ACROSS THE SOUTHEAST RIDGES.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
THERE IS ECMWF/GFS AGREEMENT THAT THE RIDGE WILL CONTINUE TO BUILD
NORTHEASTWARD WITH ITS AXIS CENTERED ACROSS THE AREA ON SUNDAY. THIS
WILL ALLOW FOR DRY WEATHER TO CONTINUE SATURDAY THROUGH MOST OF
SUNDAY. SOME UNCERTAINTY ENTERS THE FORECAST LATE SUNDAY, AS THE UPPER
LOW BEGINS TO RETROGRADE. THIS HAS BEEN ACCOUNTED FOR WITH SCHC
POPS ACROSS THE SOUTHEAST RIDGES. WITH GFS 850MB TEMPS WARMING TO
14-16C, HIGHS ON SATURDAY AND SUNDAY ARE 10 TO 15 DEGREES ABOVE
NORMAL WITH MANY LOWLAND LOCATIONS WARMING INTO THE MID 80S.
AROUND 30 DEGREE DIURNAL RANGES ARE ANTICIPATED AS A WEAK FLOW
WITH DRY AIR ALLOWS FOR STRONG RADIATIONAL COOLING EACH NIGHT.
RIDGING WILL BECOME PINCHED OFF AS THE CLOSED LOW ACROSS THE
CAROLINAS CONTINUES TO RETROGRADE AND A TROUGH MOVES INTO THE GREAT
LAKES ON MONDAY. THIS WILL ALLOW FOR ATLANTIC-STREAM MOISTURE TO
FILTER INTO THE AREA WITH MORE HUMID CONDITIONS ANTICIPATED. IN
ADDITION, A FRONTAL BOUNDARY WILL APPROACH FROM THE WEST LATE ON
MONDAY. MOISTURE WILL CONTRIBUTE TO INCREASING INSTABILITY AND
THUS THE CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA
MONDAY AFTERNOON. INCREASING CLOUDINESS WILL LIMIT TEMPS SLIGHTLY
ON MONDAY, WITH HIGHS STILL AROUND 10 DEGREES ABOVE NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS CONTINUE TO DISAGREE SOMEWHAT WITH REGARD TO TIMING OF THE
FRONT APPROACHING FROM THE WEST AND ON THE EXTENT OF
RETROGRESSION OF EAST COAST LOW EARLY NEXT WEEK.
STAYED CLOSE TO HPC GUIDANCE WHICH STILL LEANS TOWARD FASTER GFS
TIMING WITH THE FRONT AND PUSHES THE MAIN AREA OF PRECIPITATION
EAST OF THE REGION BY WEDNESDAY NIGHT.
A WEAK SURFACE RIDGE SHOULD PROVIDE GENERALLY DRY WEATHER FOR
THURSDAY INTO FRIDAY FOR MUCH OF THE FORECAST AREA. MOIST SOUTHEAST
FLOW FROM THE ATLANTIC DEPICTED BY THE ECMWF COULD MAINTAIN
SCATTERED PRECIPITATION OVER THE RIDGES ON THURSDAY NIGHT AND
FRIDAY.
TEMPERATURES ARE FORECAST TO RANGE FROM 5 TO 10 DEGREES ABOVE NORMAL
THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS AND LIGHT EAST WINDS WILL PREVAIL THROUGH THE TAF
PERIOD AS A SURFACE RIDGE HOLDS ALONG THE APPALACHIANS.
.OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
THE SURFACE RIDGE WILL MAINTAIN VFR WEATHER THROUGH SUNDAY NIGHT.
A FRONT WILL APPROACH FROM THE WEST LATE MONDAY WHILE A LOW
PRESSURE SYSTEM MOVES INLAND FROM THE CAROLINA COAST. MOISTURE
WILL INCREASE ACROSS THE REGION BY LATE MONDAY ALONG WITH THE
POTENTIAL FOR RESTRICTIONS IN SHOWERS AND THUNDERSTORMS. SCATTERED
PRECIPITATION SHOULD PERSIST THROUGH WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
332 PM EDT FRI MAY 18 2012
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FOR DRY WEATHER WITH A WARMING TREND
CONTINUING THROUGH THE WEEKEND. THE CHANCE OF SHOWERS AND
THUNDERSTORMS WILL RETURN ON MONDAY AS A FRONTAL BOUNDARY
APPROACHES FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE AXIS
EXTENDING FROM THE ARKLATEX REGION INTO THE LOWER GREAT LAKES. AT
THE SURFACE, A 1025MB HIGH IS CENTERED ACROSS NEW ENGLAND AND
EXTENDS SOUTHWESTWARD INTO THE UPPER OHIO VALLEY. MEANWHILE, A
CLOSED LOW IS DEVELOPING OFF THE CAROLINA COAST.
THE 500MB RIDGE WILL BUILD IN FURTHER INTO THE GREAT LAKES REGION
TODAY AND TONIGHT WITH WEAK ANTI-CYCLONIC FLOW ALOFT CENTERED ACROSS
NORTHERN OHIO BY 12Z SATURDAY. THIS WILL ALLOW ABUNDANT SUNSHINE TO
CONTINUE INTO THE EVENING. WITH NEAR CALM WINDS AND CLEAR SKIES
TONIGHT, RADIATIONAL COOLING WILL ALLOW FOR TEMPERATURES TO
STEADILY DROP OFF. OVERNIGHT LOWS WILL RANGE FROM THE LOWER 40S
ACROSS THE I-80 CORRIDOR AND EASTERN RIDGES TO THE LOWER 50S
ACROSS PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL WV. WITH SUPPORT
FROM THE LAMP, PATCHY RADIATION FOG IS FORECAST TO DEVELOP
OVERNIGHT ACROSS THE SOUTHEAST RIDGES.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
THERE IS ECMWF/GFS AGREEMENT THAT THE RIDGE WILL CONTINUE TO BUILD
NORTHEASTWARD WITH ITS AXIS CENTERED ACROSS THE AREA ON SUNDAY. THIS
WILL ALLOW FOR DRY WEATHER TO CONTINUE SATURDAY THROUGH MOST OF
SUNDAY. SOME UNCERTAINTY ENTERS THE FORECAST LATE SUNDAY, AS THE UPPER
LOW BEGINS TO RETROGRADE. THIS HAS BEEN ACCOUNTED FOR WITH SCHC
POPS ACROSS THE SOUTHEAST RIDGES. WITH GFS 850MB TEMPS WARMING TO
14-16C, HIGHS ON SATURDAY AND SUNDAY ARE 10 TO 15 DEGREES ABOVE
NORMAL WITH MANY LOWLAND LOCATIONS WARMING INTO THE MID 80S.
AROUND 30 DEGREE DIURNAL RANGES ARE ANTICIPATED AS A WEAK FLOW
WITH DRY AIR ALLOWS FOR STRONG RADIATIONAL COOLING EACH NIGHT.
RIDGING WILL BECOME PINCHED OFF AS THE CLOSED LOW ACROSS THE
CAROLINAS CONTINUES TO RETROGRADE AND A TROUGH MOVES INTO THE GREAT
LAKES ON MONDAY. THIS WILL ALLOW FOR ATLANTIC-STREAM MOISTURE TO
FILTER INTO THE AREA WITH MORE HUMID CONDITIONS ANTICIPATED. IN
ADDITION, A FRONTAL BOUNDARY WILL APPROACH FROM THE WEST LATE ON
MONDAY. MOISTURE WILL CONTRIBUTE TO INCREASING INSTABILITY AND
THUS THE CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA
MONDAY AFTERNOON. INCREASING CLOUDINESS WILL LIMIT TEMPS SLIGHTLY
ON MONDAY, WITH HIGHS STILL AROUND 10 DEGREES ABOVE NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS CONTINUE TO DISAGREE SOMEWHAT WITH REGARD TO TIMING OF THE
FRONT APPROACHING FROM THE WEST AND ON THE EXTENT OF
RETROGRESSION OF EAST COAST LOW EARLY NEXT WEEK.
STAYED CLOSE TO HPC GUIDANCE WHICH STILL LEANS TOWARD FASTER GFS
TIMING WITH THE FRONT AND PUSHES THE MAIN AREA OF PRECIPITATION
EAST OF THE REGION BY WEDNESDAY NIGHT.
A WEAK SURFACE RIDGE SHOULD PROVIDE GENERALLY DRY WEATHER FOR
THURSDAY INTO FRIDAY FOR MUCH OF THE FORECAST AREA. MOIST SOUTHEAST
FLOW FROM THE ATLANTIC DEPICTED BY THE ECMWF COULD MAINTAIN
SCATTERED PRECIPITATION OVER THE RIDGES ON THURSDAY NIGHT AND
FRIDAY.
TEMPERATURES ARE FORECAST TO RANGE FROM 5 TO 10 DEGREES ABOVE NORMAL
THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS AND LIGHT EAST WINDS WILL PREVAIL THROUGH THE TAF
PERIOD AS A SURFACE RIDGE HOLDS ALONG THE APPALACHIANS.
.OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
THE SURFACE RIDGE WILL MAINTAIN VFR WEATHER THROUGH SUNDAY NIGHT.
A FRONT WILL APPROACH FROM THE WEST LATE MONDAY WHILE A LOW
PRESSURE SYSTEM MOVES INLAND FROM THE CAROLINA COAST. MOISTURE
WILL INCREASE ACROSS THE REGION BY LATE MONDAY ALONG WITH THE
POTENTIAL FOR RESTRICTIONS IN SHOWERS AND THUNDERSTORMS. SCATTERED
PRECIPITATION SHOULD PERSIST THROUGH WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
210 PM EDT FRI MAY 18 2012
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FOR QUIET WEATHER AND A WARMING TREND
THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO
INCREASE SKY GRIDS AS DIURNAL CU DEVELOPS ACROSS PORTIONS OF
NORTHERN WV.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE AXIS
EXTENDING FROM THE ARKLATEX REGION INTO THE LOWER GREAT LAKES. AT
THE SURFACE, A 1025MB HIGH IS CENTERED ACROSS NEW ENGLAND AND
EXTENDS SOUTHWESTWARD INTO THE UPPER OHIO VALLEY. MEANWHILE, A
CLOSED LOW IS DEVELOPING OFF THE CAROLINA COAST. THE 12Z KPIT
SOUNDING INDICATES DEEP SUBSIDENCE AND DRY AIR ALOFT.
THE 500MB RIDGE WILL BUILD IN FURTHER INTO THE GREAT LAKES REGION
TODAY AND TONIGHT WITH ANTI-CYCLONIC FLOW ALOFT CENTERED ACROSS
NORTHERN OHIO BY 12Z SATURDAY. THIS WILL ALLOW ABUNDANT SUNSHINE TO
CONTINUE ACROSS THE REGION. HIGHS TODAY ARE A FEW DEGREES WARMER
THAN LAMP GUIDANCE, WARMING TO NEAR 80 ACROSS MUCH OF THE AREA.
WITH NEAR CALM WINDS AND CLEAR SKIES TONIGHT, RADIATIONAL COOLING
WILL ALLOW FOR TEMPERATURES TO STEADILY DROP OFF. OVERNIGHT LOWS
WILL RANGE FROM THE MID 40S ACROSS THE I-80 CORRIDOR AND EASTERN
RIDGES TO THE LOWER 50S ACROSS PORTIONS OF EASTERN OHIO AND
NORTH-CENTRAL WV.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
HIGH PRESSURE RIDGE WILL CONTINUE TO DOMINATE THE FORECAST THROUGH
AT LEAST SUNDAY AS SUGGESTED BY MOST GLOBAL MODELS. AS THE RIDGE
CONTINUES TO BUILD AND SLIDE TOWARD THE COAST...850MB TEMPERATURES
ALOFT WILL REACH 16C...WHICH SHOULD HELP TO BRING TEMPERATURES 5
TO 10 DEGREES ABOVE NORMAL SATURDAY AND SUNDAY. THOUGH CURRENT
FORECAST HIGHS ARE SLIGHTLY BELOW MOS GUIDANCE...WHICH LOOKED A
LITTLE TOO HIGH.
MODEL AGREEMENT THEN DIVERGES INTO SUNDAY NIGHT AND MONDAY ON THE
TIMING AND PLACEMENT OF THE MID-UPPER LEVEL CLOSED LOW OVER THE
SOUTHEAST. THERE CONTINUES TO BE A GROUPING BETWEEN THE
NAM/CANADIAN AND GFS/ECMWF. SINCE NOT MUCH HAS CHANGED IN THE
DETERMINISTIC MODELS WITH THE NEW RUNS...OPTED TO CONTINUE THE DRY
FORECAST FOR SUNDAY NIGHT...GRADUALLY BRINGING IN POPS FROM BOTH
THE EAST WITH THE RETROGRADING LOW AND THE WEST WITH THE SLOW
MOVING COLD FRONT BY LATE MONDAY. THIS WAS CLOSEST TO GFS/ECMWF
AND SREF ENSEMBLE MEAN THROUGH THE PERIOD. KEPT TEMPERATURES A FEW
DEGREES ABOVE MOS GUIDANCE AND STILL A FEW DEGREES ABOVE NORMAL
MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
WITH CONTINUED MODEL DISAGREEMENT...MAINTAINED A FORECAST CLOSE TO
HPC GUIDANCE WITH HEAVY EMPHASIS ON THE MOST RECENT GFS RUN WHICH
BRINGS THE COLD FRONT THROUGH THE REGION THE FASTEST MONDAY NIGHT
AND TUESDAY.
A SURFACE RIDGE PROGGED TO BUILD IN FROM THE MIDWEST LATE WEDNESDAY
INTO THURSDAY SHOULD PROVIDE A RETURN TO DRY WEATHER FOR THE MIDDLE
OF THE WEEK.
TEMPERATURES ARE FORECAST TO RANGE FROM 5 TO 10 DEGREES ABOVE NORMAL
THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD AS SURFACE HIGH
PRESSURE SLIDES EASTWARD FROM THE GREAT LAKES AND OVER NEW ENGLAND.
LGT NE SFC WND WL VEER TO THE E ON FRIDAY WITH PROGRESS OF THE HIGH.
.OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
HIGH PRESSURE WILL CONTINUE TO SUPPORT VFR CONDITIONS THROUGH THE
WEEKEND. A COLD FRONT APPROACHING FROM THE WEST WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS WITH THE POTENTIAL FOR RESTRICTIONS LATE
MONDAY THROUGH TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
152 PM EDT FRI MAY 18 2012
.UPDATE...
ISSUED AT 1005 AM EDT FRI MAY 18 2012
INCREASED POPS TO CATEGORICAL AND INCREASED SKY COVER FOR REST OF
MORNING AS BATCH OF SHRA/SCT TSRA MAINLY AFFECT AREAS FM MUNISING TO
NEWBERRY INTO EASTERN UPR MICHIGAN. BASED ON REPORTS SO FAR...EXPECT
RAIN AMOUNTS TO END UP LESS THAN 0.25 INCH MOST AREAS. SKIES HAVE
ALREADY CLEARED OVER WEST AND SOUTHWEST UPR MICHIGAN. 12Z GRB
SOUNDING POINTS TO MAX TEMPS AS WARM AS LOWER 90S. MAY NEED TO RAISE
TEMPS SOME OVER FCST...BUT WILL WAIT FOR TEMP TRENDS NEXT FEW HOURS
BEFORE MAKING SIGNIFICANT ADJUSTMENTS. REST OF FCST ON TRACK FOR
NOW.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 421 AM EDT FRI MAY 18 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER CNTRL
NAMERICA BTWN TROFS ALONG THE W COAST AND OVER QUEBEC. ALTHOUGH NO
REAL STRONG SHRTWV IS NOTICEABLE ROUNDING THE TOP OF THE RDG AND
AIRMASS TO THE S IS QUITE DRY PER 00Z MPX RAOB...A CLUSTER OF
SHRA/TS HAS DEVELOPED ON A WNW-ESE AXIS IN AREA OF VIGOROUS H85
THETA-E ADVCTN UNDER AREA OF UPR DVGC INDICATED BY VARIOUS MODELS
AT NOSE OF NOCTURNAL STRENGTHENING H85 SW LLJ BTWN HI PRES OVER LWR
MI AND LO PRES IN ERN NDAKOTA. SPC ANALYSIS INDICATES MUCAPE 500-
1000 J/KG IN THIS AREA NEAR H85 WARM FNT WITH THE STRONG H85 WARMING
SHARPENING LAPSE RATES. EVEN THOUGH THESE STORMS APPEAR TO BE
ELEVATED...SOME OF THEM HAVE CAUSED WIND GUSTS UP TO 30-40 KTS.
FARTHER TO THE S...THE AIRMASS IN THE WARM SECTOR IS VERY WARM AND
DRY. HI TEMPS OVER SW MN ROSE INTO THE LO 90S YDAY WITH DEWPTS AS LO
AS 35 TO 40 UNDER MOSUNNY SKIES. LLVL MSTR AT OMAHA WAS QUITE A BIT
GREATER AT 00Z THAN JUST TO THE N
MAIN FCST CONCERNS IN THE SHORT TERM ARE SHRA/TS CHCS THRU THIS MRNG
AND THEN FIRE WX THIS AFTN/SAT AS WARM AND DRY AIR TO THE S SURGES
INTO THE UPR LKS.
TODAY...EXPECT LINGERING SHRA/TS OVER THE KEWEENAW/NRN TIER IN THE
MRNG TO DRIFT TO THE NE WITH PASSAGE OF H85 WARM FNT UNDER BLDG UPR
RDG TO THE E OF DEEPENING TROF OVER THE W. STEADY SSW FLOW IN THE
WAKE OF THE WARM FROPA IS FCST TO PUSH H85 TEMPS AS HI AS 18C OVER
THE W HALF. MIXING TO H8 ON NAM FCST SDNGS INDICATES HI TEMPS WL
REACH 85 OVER THE W HALF WITH INCRSG SUNSHINE...BUT LOCATIONS
DOWNSTREAM OF LK MI WL BE COOLER. FORTUNATELY FOR FIRE WX
CONCERNS...MODELS ARE IN GOOD AGREEMENT SHOWING HIER LLVL MSTR
RETURNING INTO THE W HALF THRU THE DAY AS THE FLOW TAPS THE GREATER
MSTR SHOWN ON THE OMAHA RAOB AND THE SW WIND DIMINISHING A BIT WITH
ARRIVAL OF WEAKER PRES FALLS TO THE N. AXIS OF DRIER AIR WL REMAIN
OVER THE E HALF...BUT MODERATION OFF LK MI WL HOLD TEMPS DOWN IN
THAT AREA SOMEWHAT. SFC HEATING WL SUPPORT MIXING OF H95-9 WINDS UP
TO 35 KTS...STRONGEST OVER THE E. SEE THE FIRE WX DISCUSSION FOR
MORE DETAILS ON FIRE WX CONCERNS.
TNGT...CWA WL BE IN WARM SECTOR TNGT WITH UPR RDG OVER THE CNTRL GRT
LKS. STEADY SW FLOW/H925 WIND UP TO 35 KTS UNDER SHARP PRES GRADIENT
BTWN HI PRES RETREATING TO THE E AND LO PRES ADVANCING SLOWLY THRU
THE PLAINS WL LIMIT THE DIURNAL FALL OF TEMP DESPITE A MOCLR
SKY...ESPECIALLY ACRS THE DOWNSLOPE AREAS OF THE W AND NCNTRL AS
REFLECTED IN PREVIOUS FCST.
SAT...UPR MI WL REMAIN UNDER THE STEADY SSW FLOW BTWN HI PRES TO THE
E AND LO PRES TROF/COLD FNT ADVANCING THRU MN. WITH HI AMPLITUDE UPR
RDG OVER THE GRT LKS/NE CONUS...PREFER A SLOWER EWD PROGRESSION FOR
THE TROF AS SHOWN BY THE 00Z CNDN MODEL. SO RESTRICTED ANY POPS TO
FAR WRN LK SUP LATE IN THE DAY. MIXING TO H8-75 YIELDS HI TEMPS
APRCHG 90 OVER THE W HALF AWAY FM THE MODERATING INFLUENCE OF LK MI.
THIS DAYTIME MIXING WL ONCE AGAIN TAP H925 WINDS UP TO 35 KTS.
AXIS OF DRIEST AIR REMAINS OVER THE E...BUT FLOW OFF LK MI WL LIKELY
MODERATE MIXING/IMPACT ON SFC DEWPTS.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 421 AM EDT FRI MAY 18 2012
THE PERIOD STARTS 00Z SUN WITH A 500MB RIDGE AXIS JUST E OF THE CWA.
MORE IMPORTANTLY...TO OUR W WILL BE A 500MB TROUGH FROM NRN SASK TO
THE CENTRAL PLAINS STATES. THERE WILL BE A SHORTWAVE TROUGH PUSHING
THROUGH FAR WRN ONTARIO...WITH A 1002MB SFC LOW BENEATH IT. MODELS
SHOW FAIRLY GOOD AGREEMENT ON POSITION OF THESE FEATURES AND WITH
THE POSITION OF A SFC TROUGH/COLD FRONT JUST W OF THE CWA AT 00Z
SUN.
SAT NIGHT THROUGH MON...MODELS SHOW SAME GENERAL IDEA THAT THE
COLD FRONT WILL CROSS THE CWA...PRODUCING PRECIP ACROSS THE
AREA...BUT DIFFER IN TIMING. THE 00Z/18 GFS CONTINUES TO BE A FAST
OUTLIER WITH FROPA. THE 12Z/17 ECMWF CONTINUES TO BE ON THE SLOWER
SIDE...BUT IS CLOSER TO THE MORE MIDDLE GROUND 00Z/18 NAM AND 00Z/18
GEM MODELS THAN THE GFS IS. THE SLOWER SOLUTION IS ALSO SUPPORTED BY
THE FACT THAT THE SYSTEM WILL BE PUSHING INTO THE UPPER
RIDGE...WHICH TYPICALLY RESULTS IN SLOWER MOVEMENT OF THE SYSTEM.
USED A NAM/GEM/ECMWF MIX FOR THIS PART OF THE FORECAST. THIS RESULTS
IN THE FRONT MOVING INTO WRN UPPER MI AROUND 15Z SUN...THEN MOVING
THE CENTRAL UPPER MI AROUND 00Z MON...AND MOVING TO FAR ERN UPPER BY
AROUND 09Z MON. BULK OF MOISTURE...CLOUDS AND PRECIP WILL BE ALONG
AND BEHIND THIS ANAFRONT...ALLOWING FOR PLENTY OF TIME FOR SFC
HEATING AND DESTABILIZATION SUN OVER CENTRAL AND WESTERN UPPER MI.
HIGHS SUN LOOK TO BE IN THE MID TO UPPER 70S OVER CENTRAL AND PARTS
OF WRN UPPER MI...AND EVEN AS HIGH AS THE MID 80S OVER SOUTH CENTRAL
AND FAR ERN UPPER MI. MODELS SHOW SBCAPE OF 1000-1500J/KG AHEAD OF
TO JUST BEHIND THE COLD FRONT....WITH 0-6KM BULK SHEAR AROUND 30KTS.
CANNOT RULE OUT POSSIBILITY OF AN ISOLATED SEVERE THREAT FROM
CONVECTION SUN AFTERNOON/EVENING...BUT NOT CONFIDENT ENOUGH TO
MENTION SPECIFICALLY IN HWO. I THINK THE BEST CHANCE FOR SEVERE
THUNDERSTORMS WOULD BE OVER SOUTH CENTRAL UPPER MI AS THE FRONT
INTERACTS WITH LAKE MICHIGAN LAKE BREEZE BOUNDARIES. DID UP POPS FOR
THE PERIOD TO INCLUDE SOME LIKELY POPS...WHICH I WAS COMFORTABLE
DOING GIVEN PWATS AT 200 PERCENT OF NORMAL AND SLOW MOVEMENT OF THE
FRONT THROUGH GOOD INSTABILITY.
SFC HIGH PRESSURE MOVES IN BEHIND THE SFC TROUGH...AND MOVES E OF
THE CWA WED AS AN UPPER RIDGE MOVES OVERHEAD. THIS UPPER RIDGE GETS
SHUNTED E AS A LOW PRESSURE SYSTEM MOVES IN THE NRN PLAINS...BUT
THERE IS A LOT OF DISAGREEMENT BETWEEN MODELS ON THE STRENGTH AND
LOCATION OF THIS SYSTEM. MOST OF THE CWA SHOULD STAY DRY TUE THROUGH
THU...WITH A GENERAL WARMING TREND MON THROUGH THU.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 150 PM EDT FRI MAY 18 2012
WARM FRONT IS NORTH OF THE AREA AND ONLY CLOUDS THROUGH SATURDAY
AFTN WILL BE HIGH AND SCATTERED VARIETY. VFR CONDITIONS DOMINATE. SW
WINDS COULD BE GUSTY THIS AFTN AT IWD AND SAW. LATER THIS EVENING
THROUGH DAYBREAK ON SATURDAY...EXPECT MORE LLWS AS DIURNAL MIXING
DIMINISHES SFC WINDS BUT LOW-LVL JET MAX OF 35 TO 40 KT REMAINS OVER
THE AREA. MORE GUSTY SW WINDS EXPECTED ON SATURDAY...ESPECIALLY AT
IWD AND SAW. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 421 AM EDT FRI MAY 18 2012
WINDS ACROSS LAKE SUPERIOR SHOULD REMAIN BELOW 25KTS THROUGH THE
PERIOD. HIGH PRESSURE ACROSS THE LOWER GREAT LAKES WILL SLOWLY MOVE
TO NEW ENGLAND TODAY INTO SATURDAY. LOW PRESSURE OVER SOUTHERN
SASKATCHEWAN AND THE DAKOTAS WILL PUSH ACROSS THE NORTHERN AND
CENTRAL PLAINS THROUGH SATURDAY...BEFORE SLIDING NORTH INTO ONTARIO
SATURDAY. THIS WILL ALLOW A COLD FRONT TO PUSH ACROSS THE UPPER
GREAT LAKES SUNDAY INTO EARLY MONDAY. BEHIND THE FRONT...HIGH
PRESSURE WILL BUILD IN FROM THE CENTRAL AND NORTHERN PLAINS THROUGH
TUESDAY.
&&
.FIRE WEATHER...
ISSUED AT 421 AM EDT FRI MAY 18 2012
DRY SPELL THIS SPRING IS LEADING TO ANOTHER ACTIVE PERIOD OF FIRE
WX. FIRE WEATHER WATCHES ARE IN EFFECT FOR ALL OF UPR MI. A
PROLONGED PERIOD OF AT LEAST NEAR CRITICAL FIRE WX CONDITIONS IS ON
TAP FOR THIS AFTERNOON THROUGH SAT AFTERNOON.
AXIS OF STRONGER WINDS/LOWEST H95-85 SPECIFIC HUMIDITY LINES UP OVER
THE E THIS AFTN...BUT SW FLOW OFF LK MI PRESENTS A CHALLENGE AS TO
HOW MUCH COOLING/MOISTENING WILL OCCUR RELATED TO THE LAKE
MODERATION. ALTHOUGH MAX TEMPS OVER THE W WILL BE HIER...GRADUAL
ARRIVAL OF MOISTER AIR WILL TEND TO MITIGATE THE DIURNAL FALL OF RH.
CONSIDERING THE SHOWERS THAT FELL OVER MOST OF THE AREA EARLY THIS
MRNG AND EXPECTED MIN RH IN THE 25-30 PERCENT RANGE...OPTED TO ISSUE
A WILDFIRE POTENTIAL STATEMENT IN LIEU OF A RED FLAG WARNING EVEN
THOUGH DEEP MIXING THIS AFTERNOON WILL TRANSPORT STRONGER WINDS TO
THE SFC AT TIMES.
STEADY S WIND TNGT WL LIMIT DIURNAL FALL OF TEMP...EXACERBATING THE
DRYNESS.
ON SAT...ANOTHER DAY WHERE THE AXIS OF DRIEST AIR WILL BE ACROSS ERN
UPR MI. ALTHOUGH DEEP MIXING THAT WILL TAP STRONGER WINDS OFF THE
SFC WOULD ALSO TEND TO LOWER THE MIN RH...FLOW OFF LAKE MI WILL
MODERATE THE FALL OF RH. EXPECTED MIN RH AND POTENTIAL FOR GUSTY
WINDS AFTER A NIGHT OF LIMITED RH RECOVERY JUSTIFIED MAINTAINING THE
GOING FIRE WX WATCH IN THE AFTERNOON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING FOR MIZ001>015-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...JLA
MARINE...TITUS
FIRE WEATHER...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
414 PM CDT FRI MAY 18 2012
.DISCUSSION...
MOSTLY SUNNY SKIES AND STRONG SOUTHERLY WINDS ACROSS THE UPPER
MIDWEST AHEAD OF A SURFACE TROUGH LOCATED OVER THE HIGH PLAINS
ALLOWED FOR NEAR RECORD WARMTH THIS AFTERNOON IN MINNESOTA AND
WISCONSIN. THE TROUGH OF LOW PRESSURE WILL GRADUALLY SLIDE
EASTWARD IN RESPONSE TO THE UPPER LEVEL FORCING...LEADING TO
SHOWERS AND THUNDERSTORMS CHANCES FOR THE WEEKEND. THERE WILL BE A
BRIEF DRY PERIOD MONDAY AND TUESDAY...WITH ON AND OFF THUNDERSTORM
CHANCES RETURNING FOR THE LATTER HALF OF THE PERIOD.
TODAY THROUGH SUNDAY...
LATEST WATERVAPOR IMAGERY COMBINED WITH 500MB HEIGHTS AND WINDS
SHOWED A BROAD LONGWAVE ACROSS THE GREAT BASIN...WITH UPPER LEVEL
DIVERGENCE DOWNSTREAM OVER THE HIGH PLAINS. THIS DIVERGENCE CAN BE
SEEN IDENTIFIED BY BOTH THE WIDESPREAD CLOUD FIELD AND SURFACE
PRESSURE TROUGH OVER THE HIGH PLAINS OF EASTERN MONTANA AND THE
WESTERN DAKOTAS. WITHIN THIS FLOW WERE A FEW FEATURES OF INTEREST.
THE FIRST OF WHICH IS A SHORTWAVE CROSSING THE MISSOURI RIVER
VALLEY INTO WESTERN IOWA. AN ADDITIONAL WAVE IS OFF THE BRITISH
COLUMBIA COAST...ALONG WITH A FEW EMBEDDED SHORTAVES IN THE
LONGWAVE THROUGH NEAR THE 4 CORNERS REGION. THE FIRST WAVE IS
ENOUGH TO SPARK A FEW ISOLATED SHOWERS ACROSS THE SOUTHWESTERN
CWA...AS INDICATED BY THE LAST FEW HRRR RUNS...AND CU FIELD. THE
MAIN CHANCE FOR PRECIP WILL BE LATER TOMORROW BEGINNING OUT WEST
AND SPREADING ACROSS THE THE REGION FOR SATURDAY NIGHT INTO
SUNDAY. LARGE SCALE ASCENT ASSOCIATED WITH THE UPPER LEVEL TROUGH
WILL BEGIN TO OVERTAKE THE REGION...WITH A FEW FOCUSED AREAS OF
PRECIP AS 3 DIFFERENT IDENTIFIABLE SHORTWAVES MOVE ACROSS THE
REGION. IS LOOKS LIKE THE BEST CHANCE FOR RAIN WILL BE SATURDAY
NIGHT INTO SUNDAY MORNING...AND HAVE INCREASED THE POPS AND QPF
DURING THIS TIME FRAME. FORECAST SOUNDINGS SHOW SOME DIRECTIONAL
SHEAR...BUT OVERALL THE WINDSPEEDS ARE LESS THAN 50KTS. THE SHEAR
INCREASES SATURDAY NIGHT AS THE LOW LEVEL JET STRENGTHENS...BUT
THE UPPER LEVEL WINDS REMAIN LESS THAN 50KTS. SOUNDINGS ALSO
INDICATE 1500 TO 2000 J/KG OF CAPE. SO BOTTOM LINE IS THE
POTENTIAL FOR SEVERE WEATHER DOES EXIST...BUT IT SHOULD BE
SPORADIC IN NATURE. IT LOOKS LIKE WE SHOULD SEE SOME GOOD SOAKING
RAINS WITH MULTIPLE ROUNDS OF PRECIP AS EACH WAVE MOVES
THROUGH
MONDAY THROUGH FRIDAY....DRY WEATHER IS EXPECTED AS HIGH PRESSURE
WILL BUILD ACROSS THE REGION FOR MONDAY AND TUESDAY. ON WEDNESDAY
A POWERFUL 120-140KT JET WILL CROSS THE WEST COAST AND MOVE
INLAND. AS IT DIGS OVER THE WESTCENTRAL US...IT WILL TAKE ON A
NEGATIVE TILT. THIS SETUP WILL DEVELOP A CYCLONE ACROSS THE HIGH
PLAINS...AND HAS THE POTENTIAL TO PRODUCE SOME SEVERE WEATHER FOR
THE LATTER HALF OF NEXT WEEK OVER THE GREAT PLAINS REGION. IT IS
TOO EARLY TO TELL THE EXACT TIMING AND PLACEMENT OF SEVERE
STORMS...BUT AS OF NOW CHOSE TO GO WITH A BLEND OF THE
GFS...ECMWF...AND PREVIOUS FORECAST...AND HAVE CHANCE POPS
THROUGHOUT THE EXTENDED PERIOD.
&&
.AVIATION.../18Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED THROUGH MUCH OF THE PERIOD...WITH PERHAPS
SOME MVFR CONDITIONS DEVELOPING OVER WESTERN AREAS AFTER 12Z SAT.
STRONG SOUTH WINDS WILL BE THE MAIN WEATHER FEATURE THIS AFTERNOON.
SOME GUSTS IN EXCESS OF 30 KNOTS OVER WESTERN AREAS IN THE AFTERNOON.
SHOULD SLACKEN A BIT OVERNIGHT AHEAD OF DAKOTAS COLD FRONT. THIS
FRONT IS PROGGED TO MOVE INTO CENTRAL MINNESOTA BY 00Z SUN.
MENTIONED A PROB30 -SHRA DEVELOPING AFTER 14Z SAT...WITH A BETTER
CHANCE OF TSRA WEST DURING THE AFTERNOON. SHOULD SEE JUST A MIX OF
MID/HIGH LEVEL CLOUDS UNTIL FRONT MOVES INTO MINNESOTA. THE FRONT
WILL GRADUALLY MOVE EAST LATE AFTERNOON AND SATURDAY EVENING INTO
WESTERN WISCONSIN SUNDAY.
KMSP...VFR CONDS CONTINUE. MAINLY HIGH CLOUDS WITH LOWERING CEILING
DEVELOPING DURING THE DAY SATURDAY. MENTIONED VCSH BEGINNING AT 19Z
SAT FOR NOW...AS MODELS ARE HINTING AT A WEAK SHORT WAVE LIFTING OUT
AHEAD OF THE COLD FRONT SATURDAY MORNING. WILL HAVE TO MONITOR THIS
FOR LATER TAF ISSUANCE. HELD OFF ON ANY THUNDER MENTION...AS BEST
CHANCE COMES IN WITH THE FRONT SATURDAY NIGHT. STRONG SOUTH WINDS
WILL CONTINUE THIS AFTERNOON...WITH GUST POTENTIAL TO 30 KNOTS
POSSIBLE. THEN WINDS EXPECTED TO SLACKEN A BIT THE
EVENING...INCREASING AHEAD OF THE FRONT AGAIN BY 14Z SAT.
OUTLOOK...
SAT NIGHT-SUN...SHRA/TSRA LIKELY WITH BRIEF MVFR/IFR POSSIBLE AS A COLD
FRONT PUSHES THROUGH.
MON-TUE...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR BLUE EARTH-BROWN-
CHIPPEWA-FARIBAULT-KANDIYOHI-LAC QUI PARLE-MARTIN-NICOLLET-
POPE-REDWOOD-RENVILLE-SIBLEY-STEVENS-SWIFT-WATONWAN-YELLOW
MEDICINE.
WI...NONE.
&&
$$
JRB/DWE
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1237 PM CDT FRI MAY 18 2012
.AVIATION...18Z TAF ISSUANCE...
GUSTY SOUTH WINDS THIS AFTERNOON UNDER VFR AND MOSTLY CLEAR SKIES.
COULD SEE SOME MID-LEVEL CONVECTION DEVELOP AROUND OR NORTH OF INL
LATE THIS AFTERNOON. OTHERWISE...MOST AREAS WILL REMAIN VFR
THROUGH TOMORROW MORNING. LLWS WILL DEVELOP ONCE AGAIN
TONIGHT...AND DIMINISH BY MID MORNING SATURDAY. COULD SEE TS IN
THE VICINITY OF BRD AND INL SAT MORNING AS THE MAIN SFC TROUGH
APPROACHES THE AREA FROM THE WEST.
&&
.PREV DISCUSSION... /ISSUED 1158 AM CDT FRI MAY 18 2012/
UPDATE...INCREASED MAX TEMPS TODAY A FEW DEGREES BASED ON SFC OBS
AND 85H TEMPS. LAKEFRONT TEMPS TRICKY AS HI RES MDLS SHOW NE WIND
AT IMMEDIATE LAKEFRONT...EXPANDING INLAND TODAY. SFC TEMPS
ALREADY APPROACHING 80 AT KDYT. ONLY ISSUE OF NOTE TODAY BESIDES
HIGH TEMPS IS POTENTIAL FOR AFTN CONVECTION ACROSS FAR
NORTH. LATEST RUC13 SHOWS MID LVL WARMING CONTINUES TO ADVECT INTO
CWA FROM WEST AND SOUTH...SUGGESTING INCREASED INHIBITION. FCST
DEEP LYR SHEAR/INSTABILITY PARAMETERS SHOW ANY OPPORTUNITY FOR
ORGANIZED ACTIVITY WOULD BE ALONG BORDER AND NORTH INTO CANADA.
REST OF FCST ON TRACK WITH SIGNIFICANT PRECIP POTENTIAL FOR SAT
AFTN INTO SUNDAY AS COLD FRONT MARCHES ACROSS REGION.
PREV DISCUSSION... /ISSUED 633 AM CDT FRI MAY 18 2012/
AVIATION...12Z TAFS
VFR CONDITIONS ARE FORECASTED THROUGH TONIGHT...WITH SCT/BKN HIGH
CLOUDS. HOWEVER...SHOWERS AND THUNDERSTORMS ARE POSSIBLE NEAR AND
NORTH OF THE INTERNATIONAL BORDER THIS AFTERNOON AND INTO
TONIGHT...BUT CONFIDENCE IS LOW AS TO WHETHER KINL WILL BE
AFFECTED BY ANY STORMS. AT THIS POINT...FORECASTED VCTS AT KINL
FROM 22Z TO 03Z. THERE IS ALSO A VERY SLIGHT CHANCE THAT KBRD AND
KHIB COULD BE AFFECTED BY SHOWERS AND STORMS TONIGHT...TOO...BUT
LEFT IT OUT OF THE FORECAST FOR NOW. GUSTY SOUTHERLY WINDS WILL
DEVELOP BY THIS AFTERNOON...AND SOMEWHAT RELAX TONIGHT. WIND
SHEAR WILL REMAIN AN ISSUE THIS MORNING AT KDLH/KHIB/KBRD/KHYR DUE
TO STRONG SOUTHWESTERLY WINDS...BUT THOSE WINDS WILL SIGNIFICANTLY
WEAKEN BY THIS AFTERNOON. WIND SHEAR WILL BE AN ISSUE AGAIN
TONIGHT WHEN THE SOUTHWESTERLY WINDS INCREASE AGAIN.
PREV DISCUSSION... /ISSUED 347 AM CDT FRI MAY 18 2012/
SHORT TERM...THE MAIN SHORT TERM FOCUS IS TEMPERATURES...WINDS
AND PRECIPITATION CHANCES.
SHOWERS AND THUNDERSTORMS HAD GENERALLY MOVED OUT OF THE CWA AS OF
330 AM. SOME SHOWERS WERE STILL NOTED JUST SOUTH OF GRAND PORTAGE
OVER LAKE SUPERIOR. THE WARM FRONT WAS FAIRLY EASY TO PICK OUT
THIS MORNING. THE 3 AM TEMPERATURE AT GRAND RAPIDS WAS 57
DEGREES... WHILE IT WAS 70 AT LONGVILLE AND AITKIN...WITH A SUBTLE
WIND SHIFT FROM SOUTHEAST TO SOUTHWEST.
AS THE WARM SECTOR CONTINUES TO BUILD ACROSS THE NORTHLAND
TODAY...WITH THE WARM FRONT CONTINUING TO MOVE NORTHWARD...WE
SHOULD SEE GENERALLY DRY CONDITIONS FOR MOST OF THE NORTHLAND.
STILL THINK THERE WILL BE SOME SHOWERS AND STORMS ACROSS THE
NORTHERN 1/3 OF THE CWA...AND WILL CONTINUE TO MENTION POPS FOR
THOSE AREAS. TEMPS ARE A BIT TRICKY GIVEN SOME LINGERING CLOUDS...
BUT THINK MOST AREAS WILL REACH THE LOWER TO MIDDLE 80S FOR
DAYTIME HIGHS. H85 TEMPS REACH +18 TO +19C TODAY. THE OTHER ISSUE
TODAY WILL BE GUSTY WINDS...WITH SUSTAINED SOUTHERLY WINDS OF 10
TO 20 MPH WITH GUSTS INTO THE MID 20 MPH RANGE.
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BE
CONFINED TO THE INTERNATIONAL BORDER REGION TONIGHT...BUT AS THE
NIGHT WEARS ON...THE FOCUS WILL SHIFT NORTHWARD INTO SC CANADA.
WITH LOW PRESSURE MOVING IN FROM THE WEST TONIGHT...SOME SHOWERS
AND STORMS MAY REACH THE WESTERN BORDER OF THE CWA LATE. TEMPS
OVERNIGHT SHOULD REMAIN MILD AS WE REMAIN IN THE WARM SECTOR.
THE COLD FRONT WILL FINALLY MOVE EASTWARD INTO THE CWA ON
SATURDAY. WILL SLOW DOWN THE EASTWARD MOVEMENT ACROSS THE CWA
BASED ON THE 00Z MODEL SET...WITH SHOWERS AND THUNDERSTORMS
BECOMING LIKELY IN THE WESTERN HALF OF THE CWA IN THE AFTERNOON.
TEMPS AHEAD OF THE FRONT SHOULD EASILY GET INTO THE 80S...BUT THEN
BACK OFF AS THE RAIN MOVES IN FOR THE WESTERN ZONES.
LONG TERM...[SATURDAY NIGHT - THURSDAY]
THE MODELS ARE IN REASONABLE AGREEMENT FOR MOST OF THE PERIOD...SO
LEANED ON A BLEND. WET WEATHER IS LIKELY ACROSS THE NORTHLAND AS A
COLD FRONT CONTINUES TO MOVE THROUGH THE EASTERN FA SATURDAY NIGHT
AND SUNDAY. THUNDERSTORMS ARE POSSIBLE THROUGH SUNDAY...BUT MOSTLY
ACROSS THE EASTERN FA. HIGH PRESSURE WILL BEGIN TO TAKE A HOLD OF
THE NORTHLAND SUNDAY NIGHT...BUT THERE MAY BE LINGERING SHOWERS
ACROSS THE EASTERN FA. MONDAY THROUGH TUESDAY LOOKS MILD AND DRY
ACROSS THE NORTHLAND AS HIGH PRESSURE CONTINUES TO INFLUENCE THE
REGION. LOW PRESSURE WILL BEGIN TO ORGANIZE IN THE WESTERN PLAINS IN
EARLY NEXT WEEK...AND SHOWERS AND THUNDERSTORMS ARE POSSIBLE TUESDAY
NIGHT INTO THURSDAY ACROSS THE NORTHLAND AS WARM SOUTHERLY FLOW
INCREASES ACROSS THE REGION.
&&
.POINT TEMPS/POPS...
DLH 82 60 82 57 / 10 0 50 70
INL 87 62 78 48 / 30 50 70 60
BRD 87 65 78 51 / 10 10 70 70
HYR 84 63 85 61 / 10 0 10 70
ASX 84 62 85 58 / 10 0 10 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...CANNON
AVIATION...TENTINGER
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1158 AM CDT FRI MAY 18 2012
.UPDATE...INCREASED MAX TEMPS TODAY A FEW DEGREES BASED ON SFC OBS
AND 85H TEMPS. LAKEFRONT TEMPS TRICKY AS HI RES MDLS SHOW NE WIND
AT IMMEDIATE LAKEFRONT...EXPANDING INLAND TODAY. SFC TEMPS
ALREADY APPROACHING 80 AT KDYT. ONLY ISSUE OF NOTE TODAY BESIDES
HIGH TEMPS IS POTENTIAL FOR AFTN CONVECTION ACROSS FAR
NORTH. LATEST RUC13 SHOWS MID LVL WARMING CONTINUES TO ADVECT INTO
CWA FROM WEST AND SOUTH...SUGGESTING INCREASED INHIBITION. FCST
DEEP LYR SHEAR/INSTABILITY PARAMETERS SHOW ANY OPPORTUNITY FOR
ORGANIZED ACTIVITY WOULD BE ALONG BORDER AND NORTH INTO CANADA.
REST OF FCST ON TRACK WITH SIGNIFICANT PRECIP POTENTIAL FOR SAT
AFTN INTO SUNDAY AS COLD FRONT MARCHES ACROSS REGION.
&&
.PREV DISCUSSION... /ISSUED 633 AM CDT FRI MAY 18 2012/
AVIATION...12Z TAFS
VFR CONDITIONS ARE FORECASTED THROUGH TONIGHT...WITH SCT/BKN HIGH
CLOUDS. HOWEVER...SHOWERS AND THUNDERSTORMS ARE POSSIBLE NEAR AND
NORTH OF THE INTERNATIONAL BORDER THIS AFTERNOON AND INTO
TONIGHT...BUT CONFIDENCE IS LOW AS TO WHETHER KINL WILL BE
AFFECTED BY ANY STORMS. AT THIS POINT...FORECASTED VCTS AT KINL
FROM 22Z TO 03Z. THERE IS ALSO A VERY SLIGHT CHANCE THAT KBRD AND
KHIB COULD BE AFFECTED BY SHOWERS AND STORMS TONIGHT...TOO...BUT
LEFT IT OUT OF THE FORECAST FOR NOW. GUSTY SOUTHERLY WINDS WILL
DEVELOP BY THIS AFTERNOON...AND SOMEWHAT RELAX TONIGHT. WIND
SHEAR WILL REMAIN AN ISSUE THIS MORNING AT KDLH/KHIB/KBRD/KHYR DUE
TO STRONG SOUTHWESTERLY WINDS...BUT THOSE WINDS WILL SIGNIFICANTLY
WEAKEN BY THIS AFTERNOON. WIND SHEAR WILL BE AN ISSUE AGAIN
TONIGHT WHEN THE SOUTHWESTERLY WINDS INCREASE AGAIN.
PREV DISCUSSION... /ISSUED 347 AM CDT FRI MAY 18 2012/
SHORT TERM...THE MAIN SHORT TERM FOCUS IS TEMPERATURES...WINDS
AND PRECIPITATION CHANCES.
SHOWERS AND THUNDERSTORMS HAD GENERALLY MOVED OUT OF THE CWA AS OF
330 AM. SOME SHOWERS WERE STILL NOTED JUST SOUTH OF GRAND PORTAGE
OVER LAKE SUPERIOR. THE WARM FRONT WAS FAIRLY EASY TO PICK OUT
THIS MORNING. THE 3 AM TEMPERATURE AT GRAND RAPIDS WAS 57
DEGREES... WHILE IT WAS 70 AT LONGVILLE AND AITKIN...WITH A SUBTLE
WIND SHIFT FROM SOUTHEAST TO SOUTHWEST.
AS THE WARM SECTOR CONTINUES TO BUILD ACROSS THE NORTHLAND
TODAY...WITH THE WARM FRONT CONTINUING TO MOVE NORTHWARD...WE
SHOULD SEE GENERALLY DRY CONDITIONS FOR MOST OF THE NORTHLAND.
STILL THINK THERE WILL BE SOME SHOWERS AND STORMS ACROSS THE
NORTHERN 1/3 OF THE CWA...AND WILL CONTINUE TO MENTION POPS FOR
THOSE AREAS. TEMPS ARE A BIT TRICKY GIVEN SOME LINGERING CLOUDS...
BUT THINK MOST AREAS WILL REACH THE LOWER TO MIDDLE 80S FOR
DAYTIME HIGHS. H85 TEMPS REACH +18 TO +19C TODAY. THE OTHER ISSUE
TODAY WILL BE GUSTY WINDS...WITH SUSTAINED SOUTHERLY WINDS OF 10
TO 20 MPH WITH GUSTS INTO THE MID 20 MPH RANGE.
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BE
CONFINED TO THE INTERNATIONAL BORDER REGION TONIGHT...BUT AS THE
NIGHT WEARS ON...THE FOCUS WILL SHIFT NORTHWARD INTO SC CANADA.
WITH LOW PRESSURE MOVING IN FROM THE WEST TONIGHT...SOME SHOWERS
AND STORMS MAY REACH THE WESTERN BORDER OF THE CWA LATE. TEMPS
OVERNIGHT SHOULD REMAIN MILD AS WE REMAIN IN THE WARM SECTOR.
THE COLD FRONT WILL FINALLY MOVE EASTWARD INTO THE CWA ON
SATURDAY. WILL SLOW DOWN THE EASTWARD MOVEMENT ACROSS THE CWA
BASED ON THE 00Z MODEL SET...WITH SHOWERS AND THUNDERSTORMS
BECOMING LIKELY IN THE WESTERN HALF OF THE CWA IN THE AFTERNOON.
TEMPS AHEAD OF THE FRONT SHOULD EASILY GET INTO THE 80S...BUT THEN
BACK OFF AS THE RAIN MOVES IN FOR THE WESTERN ZONES.
LONG TERM...[SATURDAY NIGHT - THURSDAY]
THE MODELS ARE IN REASONABLE AGREEMENT FOR MOST OF THE PERIOD...SO
LEANED ON A BLEND. WET WEATHER IS LIKELY ACROSS THE NORTHLAND AS A
COLD FRONT CONTINUES TO MOVE THROUGH THE EASTERN FA SATURDAY NIGHT
AND SUNDAY. THUNDERSTORMS ARE POSSIBLE THROUGH SUNDAY...BUT MOSTLY
ACROSS THE EASTERN FA. HIGH PRESSURE WILL BEGIN TO TAKE A HOLD OF
THE NORTHLAND SUNDAY NIGHT...BUT THERE MAY BE LINGERING SHOWERS
ACROSS THE EASTERN FA. MONDAY THROUGH TUESDAY LOOKS MILD AND DRY
ACROSS THE NORTHLAND AS HIGH PRESSURE CONTINUES TO INFLUENCE THE
REGION. LOW PRESSURE WILL BEGIN TO ORGANIZE IN THE WESTERN PLAINS IN
EARLY NEXT WEEK...AND SHOWERS AND THUNDERSTORMS ARE POSSIBLE TUESDAY
NIGHT INTO THURSDAY ACROSS THE NORTHLAND AS WARM SOUTHERLY FLOW
INCREASES ACROSS THE REGION.
&&
.POINT TEMPS/POPS...
DLH 82 60 82 57 / 10 0 50 70
INL 87 62 78 48 / 30 50 70 60
BRD 87 65 78 51 / 10 10 70 70
HYR 84 63 85 61 / 10 0 10 70
ASX 84 62 85 58 / 10 0 10 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...CANNON
AREA FORECAST DISCUSSION
NWS GLASGOW MT
307 PM MDT FRI MAY 18 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY...
WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD SHOWS A FAIRLY ACTIVE
AND PROGRESSIVE WEATHER PATTERN ACROSS THE CONUS. AREAS OF WEAK
LOW PRESSURE ARE SETTING OFF SOME THUNDERSTORMS OVER THE
SOUTHEASTERN STATES AND THE INTER-MOUNTAIN WESTERN STATES. WEAK
HIGH PRESSURE HAS TAKEN CONTROL OVER THE MID MISSISSIPPI AND OHIO
RIVER VALLEYS AND THE WEST COAST.
THE ROCKY MOUNTAIN STORM SYSTEM WHICH BROUGHT MORE THAN A WETTING
RAIN TO GLASGOW EARLY THIS MORNING CONTINUES TO MOVE SCATTERED
RAIN SHOWERS THROUGH NORTHEAST MONTANA THIS AFTERNOON. SOME
CLEARING FROM THE WEST HAS BEGUN TO EAT AWAY THE RAIN SHOWERS
WHILE MORE ORGANIZED CONVECTION CONTINUES TO SUPPORT RAIN SHOWERS
OF A MORE WIDESPREAD NATURE OVER OUR SOUTHEASTERN ZONES. HRRR AND
NAM MODELS PICKED UP ON THIS SOUTHEASTERN PRECIP VERY WELL WHILE
THE GFS IGNORED IT COMPLETELY. WOULD TEND TO LEAN A BIT AWAY FROM
THE GFS FOR POPS AND QPF IN THE NEAR SHORT TERM WHILE THIS STORM
SYSTEM MOVES AWAY TO WARD THE EAST TONIGHT. IN FACT...DURING THE
LATE TONIGHT AND OVERNIGHT HOURS THERE SEEMS TO BE VERY GOOD MODEL
AGREEMENT SHOWING THE EXITING SYSTEM BRINGING A SIGNIFICANT AMOUNT
OF RAIN TO THE FAR SOUTHEASTERN CORNER OF OUR CWA. I MAY HAVE BEEN
A LITTLE TOO CONSERVATIVE WITH QPF AND THAT MAY NEED TO BE
INCREASED WITH AN UPDATE TONIGHT.
BY SATURDAY MORNING...PRECIPITATION WILL HAVE MOVED COMPLETELY
AWAY TO THE EAST OF OUR CWA AS THE UPPER LEVEL FLOW BECOMES MORE
ZONAL AND VERY WEAK RIDGING TAKES OVER ACROSS THE REGION
THROUGHOUT THE REMAINDER OF THE WEEKEND WITH MOSTLY CLEAR SKIES.
THIS WILL ALLOW TEMPERATURES TO QUICKLY REBOUND TO NORMAL AND
ABOVE NORMAL LEVELS FOR THIS TIME OF YEAR. WIDESPREAD CLOUDINESS
WILL AGAIN APPROACH FROM THE WEST BY LATE SUNDAY IN TIME TO HELP
FILTER OUT THE ANNULAR SOLAR ECLIPSE NEAR SUNSET. BMICKELSON
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
NOT TOO MANY CHANGES WERE MADE TO GOING FORECAST AS PERIOD LOOKS
RATHER UNSETTLED. DID INCREASE THEM SLIGHTLY FOR TUESDAY AS MOISTURE
AND INSTABILITY POOL TO OUR SOUTHEAST AND MOVE IN ON RETURN
SOUTH-SOUTHEAST FLOW.
THE GFS CONTINUES TO KEEP THE AREA RATHER UNSETTLED AS A DEEP UPPER
TROUGH SETS UP OVER THE WESTERN UNITED STATES. WILL KEEP MOSTLY
CHANCE POPS GOING. JAMBA
PREVIOUS DISCUSSION...
THE EXTENDED PERIOD BEGINS SUNDAY NIGHT WITH ZONAL FLOW ALOFT
THAT WILL BECOME A NARROW WAVE UPPER RIDGE ON MONDAY. THIS RIDGING
WILL INCREASE THICKNESS HEIGHTS AND BEGIN A WARM-UP
MONDAY...POSSIBLY LASTING THROUGH TUESDAY.
MONDAY AFTERNOON AND EVENING A WEAK COLD FRONT FROM AN UPPER
TROUGH DIGGING INTO THE PAC-NW WILL MOVE INTO MONTANA. THIS FRONT
WILL INCREASE INSTABILITY...MAINLY OVER CENTRAL MONTANA. HOWEVER
SOME THUNDERSTORMS COULD DRIFT INTO NORTHEAST MONTANA. THEN ON
TUESDAY THE TROUGH SWINGS ACROSS THE NORTHERN ROCKIES SENDING
ANOTHER STRONGER COLD FRONT INTO THE NORTHERN HIGH PLAINS. THERE
ARE INDICATIONS OF EVEN GREATER INSTABILITY ON TUESDAY AND TUESDAY
EVENING...FOR THE POSSIBILITY OF SEVERAL SEVERE THUNDERSTORMS THAT
COULD MOVE INTO WESTERN NORTH DAKOTA FROM NE MONTANA.
THE GFS AND EC DISAGREE ON HOW THE TROUGH DEVELOPS. BUT BOTH SEEM
TO AGREE WITH THE TROUGH BECOMING MORE OF A LONG WAVE AND
REMAINING OVER THE REGION THROUGH THE REST OF THE EXTENDED
PERIOD...TRENDING TEMPERATURES TO BELOW AVERAGE BY THURSDAY AND
FRIDAY. THE PERIOD WILL ALSO LIKELY SEE CONTINUING PERIODS OF
SHOWER ACTIVITY. THE GFS CLOSES OFF THE LOW AND STACKS UP OVER
WESTERN NORTH DAKOTA WEDNESDAY NIGHT...WHICH TENDS TO RETROGRADE
PRECIPITATION BACK INTO NEMONT. THIS WOULD ALSO DEVELOP STRONG
WINDS. THE EC ON THE OTHER HAND LIFTS THE CLOSED UPPER LOW INTO
SOUTHERN ALBERTA AND SASKATCHEWAN. THEREFORE MODEL UNCERTAINTY
WILL MAKE POPS AND QPF AMOUNTS DIFFICULT TO FORECAST. HOWEVER THE
REST OF THE EXTENDED PERIOD SHOULD HAVE SHOWERS OR RAIN WITH THE
COOLER TEMPERATURES. SCT
&&
.AVIATION...
SCATTERED SHOWERS THIS EVENING WILL MOVE EAST INTO NORTH DAKOTA
THIS EVENING WITH CLEARING SKIES TO FOLLOW. WINDS WILL SWITCH
AROUND TO THE NORTHWEST AND INCREASE SLIGHTLY TO 10 TO 20 KTS THIS
EVENING. THE WINDS ARE EXPECTED TO CONTINUE AT SIMILAR SPEEDS
SATURDAY. JAMBA
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
330 PM CDT FRI MAY 18 2012
.DISCUSSION...
A POWERFUL UPPER LEVEL DISTURBANCE ACROSS COLO WILL MOVE SLOWLY
EAST TONIGHT AND SATURDAY PRODUCING SCATTERED TSTMS...MAINLY
ACROSS NORTH AND WEST PARTS OF THE FCST AREA WHICH WILL BE CLOSER
TO THE BEST DYNAMICS. SUPER ENSEMBLE FCST QPF SUGGESTS AROUND 1/4 INCH
OF RAIN NEAR NORTH PLATE AND CLOSE TO 3/4 OF AN INCH NEAR VALENTINE.
FOR THIS EVENING THE THREAT OF HIGH BASED TSTMS CAPABLE OF GUSTY
OR PERHAPS ISOLATED DAMAGING DOWNBURSTS WILL CONTINUE AS SFC RH IS
OPERATING BELOW 40 PERCENT. ONCE THE COLD FRONT SWEEPS SOUTH
LATER TONIGHT THE WIND THREAT SHOULD DIMINISH. THE ECM CONTINUES
TO BE SLOWER WITH COLD FRONT HOLDING IT UP SOME SATURDAY AFTERNOON
ACROSS THE ERN ZONES. THIS WAS INCORPORATED IN THE TEMP FORECAST
FOR HIGHS IN THE 70S EAST...BUT UPPER 50S TO AROUND 60 WEST.
THE UPPER LEVEL DISTURBANCE SHOULD CLEAR THE FCST AREA SATURDAY
NIGHT WITH STRONG HIGH PRESSURE BUILDING IN SUNDAY FOR NEARLY
CLEAR SKIES AND HIGHS IN THE 60S TO AROUND 70S. THE SFC HIGH WILL
MOVE OFF EAST QUICKLY MONDAY WITH SOUTHERLY RETURN FLOW DEVELOPING
AND A STRONG THERMAL RIDGE DEVELOPING ACROSS THE HIGH PLAINS AND
CNTL ROCKIES BY LATE MONDAY AFTERNOON. THIS THERMAL RIDGE SHOULD
MIGRATE EAST INTO THE NEB PANHANDLE TUESDAY AFTERNOON. MIX DOWN
TOOLS FROM 700 MB SUGGESTS HIGHS IN THE LOWER 90S. FOR NOW 80S
WILL OPERATE. ALL MODELS EXCEPT THE SLOWER AND VERY WARM GEM THEN
SWEEP A COLD FRONT THROUGH WEDNESDAY LOWERING TEMPS ABOUT 10
DEGREES. THE FRONT WILL THEN LIFT SLOWLY NORTH THROUGH KS AND
BECOME STATIONARY ACROSS SWRN NEB FRIDAY. ALL ALONG A DEEP UPPER
LEVEL TROF WILL DROP INTO THE WRN U.S. AND WINDS ALOFT WILL
BECOME SOUTHWEST AND INCREASE IN SPEED. SFC LOW PRESSURE WILL DEEPEN TO
BELOW 990 MB ACROSS WRN KS SUPPORTING WINDY CONDITIONS...SHARP
MOISTURE GRADIENTS AND A STRONG CAP...PERHAPS AS STRONG AS 12C
ACROSS SRN NEB. GIVEN THE FAST FLOW ALOFT AND FOCUS OF THE SFC
LOW...ISOLATED AND LOW-CHC POPS ARE IN PLACE LATE TUESDAY THROUGH
THURSDAY.
&&
.AVIATION...
SOUTH TO SOUTHEAST WINDS AT 15 TO 25 KTS...WILL SHIFT TO THE NORTH
AFTER 06Z SATURDAY BEHIND A COLD FRONT. THE FRONT WILL MOVE THROUGH
THE KVTN TAF SITE AROUND 06Z SATURDAY...AND INTO THE KLBF TAF SITE
AREA AROUND 09Z SATURDAY. A FEW T-STORMS WILL BE POSSIBLE BOTH THIS
EVENING AND OVERNIGHT WITH THE FRONTAL PASSAGE...BUT COVERAGE SHOULD
REMAIN LIMITED AND WILL NOT INCLUDE IN THE OFFICIAL FORECAST AT THIS
TIME. CONFIDENCE IS ALSO NOT HIGH ON ANY MVFR CEILINGS DUE TO
STRATUS BEHIND THE FRONT. HAVE ALSO LEFT THIS OUT FOR NOW...AS
CONDITIONS HAVE BEEN VERY DRY LATELY...AND NOT CERTAIN THE BOUNDARY
LAYER WILL MOISTEN ENOUGH FOR STRATUS.
&&
.FIRE WEATHER...
A FAIRLY SHARP DRYLINE HAS FORMED NEAR WRAY AND HOLYOKE COLO THIS
AFTN WHERE RH IS RUNNING 11 TO 15 PERCENT. THE RUC SHOWS THIS
DRYLINE PUSHING EAST INTO SWRN NEB LATE THIS AFTERNOON AS THE SFC
LOW MOVES EAST TO NEAR BURLINGTON COLO. THE RED FLAG WARNING WILL
CONTINUE IN EFFECT THIS EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...RED FLAG WARNING UNTIL 9 PM CDT
THIS EVENING FOR NEZ210.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
406 PM EDT FRI MAY 18 2012
.SYNOPSIS...
A WARM AND TRANQUIL WEEKEND IS IN STORE FOR THE AREA AS A DEEP
LAYERED RIDGE OF HIGH PRESSURE MOVES ACROSS OHIO INTO INTERIOR NEW
ENGLAND BY LATER ON SUNDAY. WEAK EASTERLY FLOW AT THE SURFACE WILL
HOLD DEEPER MOISTURE AT BAY...BUT HUMIDITIES WILL BE ON THE
INCREASE OVER WHAT HAS BEEN EXPERIENCED THE PREVIOUS FEW DAYS. A
WEAKENING WEATHER SYSTEM SHIFTING THROUGH THE WESTERN GREAT LAKES
SUNDAY NIGHT WILL SLOW AS IT MOVES INTO THE OHIO VALLEY...BRINGING
THE NEXT THREAT OF SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AMPLE SUNSHINE AGAIN TODAY WITH LOW DEWPOINTS /30S AND
40S/...THANKS TO DEEP LAYERED RIDGE OF HIGH PRESSURE OVER THE
AREA. 18.19Z RUC ANALYSIS INDICATED A CLOSED-CONTOUR 580DM
ANTICYCLONE OVER NRN INDIANA...ATOP A CLOSED-CONTOUR 576DM CYCLONE
JUST OFF THE SOUTH CAROLINA COAST. NOT OVER STRONG/IMPRESSIVE
SYSTEMS...BUT THIS REX BLOCK TYPE STRUCTURE WILL CONTINUE TO
DOMINATE OUR WEEKEND WEATHER PATTERN...WITH WEAK EASTERLY FLOW OUT
OF A SURFACE HIGH PRESSURE SYSTEM IN NEW ENGLAND /RATHER BAGGY
PRESSURE GRADIENT/ CONTINUING TO HOLD DEEPER BOUNDARY LAYER
MOISTURE /60S DEWPOINTS/ WELL SOUTH AND WEST OF THE AREA.
IN THE UPCOMING 12-15 HOURS...EXPECT VERY LITTLE SYNOPTIC SCALE
CHANGE AS THE MID-LEVEL HIGH DRIFTS THROUGH NRN OHIO AND
STRENGTHENS SLIGHTLY WHILE THE LOW OVER THE WRN ATL ELONGATES SOME
BEGINS SPLITTING INTO TWO DISTINCT CYCLONIC CIRCULATION
CENTERS...ONE IN ERN GA AND THE OTHER OFF THE NC COAST.
VERY WEAK SFC FLOW WILL QUICKLY GO CALM THIS EVENING UNDER RAPIDLY
STRENGTHENING INVERSION AND DECOUPLING OF THE SHALLOWING BOUNDARY
LAYER. THIS SHOULD FOSTER A RAPID EVENING TEMP DROP WITH CLEAR
SKIES. RAN A GENERAL BLEND OF THE PREVIOUS FORECAST AND 12Z
ECMWF/GFS/NAM MOS...THOUGH TWEAKED A TOUCH DOWNWARD IN THE COOL
SPOTS GIVEN IDEAL RADIATIONAL COOLING REGIME. ALSO FOGGED UP THE
OHIO AND ADJACENT RIVER VALLEYS LATER IN THE NIGHT...AS BOUNDARY
LAYER MOISTURE FROM KY WILL BE SEEPING NWRD OVERNIGHT AS MINOR SLY
COMPONENT TO THE GENERAL EASTERLY FLOW WILL ALLOW AN INCREASE IN
LLVL MOISTURE. WOULD NOT BE SURPRISED IS FOG BECOMES A LITTLE MORE
WIDESPREAD THAN FORECAST ESP OVER NRN KY/SRN OH/SERN IND.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
VERY LITTLE CHANGE TO THE PATTERN ALOFT ON SATURDAY...THOUGH THE
LOW LEVELS WILL BEGIN TO UNDERGO SOME MOISTURE ADVECTION...ESPECIALLY
ACROSS SRN/SWRN FORECAST AREA. 18.12Z WRF/GFS INDICATE LOWEST 1KM
SPECIFIC HUMIDITIES DOUBLING IN COMPARISON TO FRIDAY...SO BROUGHT
DEWPOINTS UP A BIT IN THE SOUTH/SOUTHWEST...PERHAPS NOT ENOUGH.
FEEL 18.12Z NAM-WRF SFC DWPTS ABOUT 10F TOO HIGH AS HAS BEEN A
PROBLEM THIS SPRING...SO DISCOUNTING THE RATHER STRONG INSTBY THAT
DEVELOPS UNDERNEATH THE MID LEVEL RIDGE SATURDAY AFTERNOON. EVEN
SO...ADDITIONAL MOISTURE AND A FAVORABLE LAPSE RATE WILL NO DOUBT
YIELD SOME DEEPER CUMULUS ACROSS THE SOUTH/SOUTHWEST...BUT THINK
NIL FORCING AND CONTINUED RISING HEIGHTS WILL MITIGATE A NEED FOR
A RAIN CHANCE AT THIS TIME. A WARM DAY...AND MOS SHOULD PERFORM
WELL IN THIS RATHER PREDICTABLE REGIME...SO AGAIN BLENDED PREVIOUS
FORECAST WITH MOST RECENT VALUES. SPOT CHECK OF LOW LEVEL
THICKNESS CONSIDERATIONS AND MIXING TO 850-825MB /DESPITE VERY
WEAK FLOW/ SUGGESTS WIDESPREAD LOWER TO MIDDLE 80S...VERY MUCH IN
LINE WITH THE BLEND.
LIKELY A REPEAT SCENARIO SATURDAY NIGHT WITH VALLEY FOG...AND
LOWS IN THE 50S.
SUNDAY IS A CARBON-COPY OF SATURDAY. DISTINCT CIRCULATION CENTERS
ATTENDANT TO THE SOUTHEAST CONUS TROUGH RECOMBINE OVER THE OUTER
BANKS OF NC WHILE THE MID LEVEL ANTICYCLONE CONTINUES TO DEEPEN TO
585DM OVER INTERIOR NEW ENGLAND. THIS WILL REINFORCE A LOW LEVEL
EASTERLY TRAJECTORY...THUS DON/T EXPECT MUCH /IF ANY/ DEWPOINT
RISE ON SUNDAY...AND TEMPERATURES SHOULD HOLD VERY SIMILAR TO
SATURDAY/S READINGS. PROBABLY A THICKER CIRRUS SHIELD PER BUFR
SOUNDINGS...BUT THAT WOULD BE ABOUT THE EXTENT OF SENSIBLE
WEATHER.
SUNDAY NIGHT BEGINS TO SEE SOME CHANGE AS A TROUGH OF LOW PRESSURE
/DAMPENING OUT AND SLOWING AS IT ENCOUNTERS THE BLOCKY FLOW ALONG THE
EAST COAST/ APPROACHES THE GREAT LAKES. HAVE KEPT THE NIGHTTIME
DRY AT THIS POINT AS 18.12Z GUIDANCE WAFFLING ON WEAK/MID LEVEL-
BASED SHOWERS AND STORM PLACEMENT AS FORCING SLOWLY INCREASES
LATER IN THE NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
PERIOD OF DRY WEATHER MAY COME TO AN END MONDAY AS MOISTURE AND
INSTABILITY INCREASE AHEAD OF AN UPPER TROUGH. WITH THE ECMWF AND
GFS COMING INTO FAIR AGREEMENT...KEPT A CHANCE OF THUNDERSTORMS FOR
MONDAY...MAINLY IN WESTERN COUNTIES THAT WILL BE AFFECTED MORE BY
SURFACE CONVERGENCE AND COOLER AIR ALOFT.
STAYED CLOSE TO ECMWF SOLUTION FOR TUESDAY SINCE IT CONTINUES TO
SHOW A CLOSED UPPER LOW FORMING AS OPPOSED TO THE FASTER OPEN WAVE
DEPICTED ON THE GFS. AS THE UPPER LOW FORMS NEAR CVG...THERE WILL BE
A GOOD CHANCE FOR THUNDERSTORMS UNDER A COOL POOL ALOFT COUPLED WITH
DEEP MOISTURE ADVECTION FROM THE SOUTH.
THUNDERSTORMS CHANCES WILL DIMINISH ON WEDNESDAY AS THE CLOSED UPPER
LOW SLIPS EAST ALLOWING DRIER AND MORE STABLE AIR TO WORK IN. THE
DRY CONDITIONS ARE EXPECTED TO CONTINUE ON THURSDAY AND FRIDAY WHEN
RIDGING ALOFT IS FORECAST TO MOVE BACK IN.
HIGH TEMPERATURES WILL BE MAINLY IN THE 80S MONDAY ON THE EAST SIDE
OF THE UPPER TROUGH. COOLER READINGS IN THE 70S ARE FORECAST AS THE
CLOSED LOW MAKES ITS WAY ACROSS THE AREA WITH ASSOCIATED CLOUD COVER
AND COLD ADVECTION. LOOK FOR A REBOUND TO THE 80S BY FRIDAY AS
SUNSHINE AND WARM ADVECTION RETURN.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL EXTEND ACROSS THE REGION THROUGH THE TAF PERIOD.
INCREASING LOW LEVEL MOISTURE ALONG THE OHIO RIVER WILL BRING SOME
RIVER FOG TO THE SRN TAF SITES. KCVG SHOULD HAVE A PERIOD OF MVFR
VSBY RESTRICTIONS WITH KLUK LIKELY FLUCTUATING BETWEEN IFR TO
VLIFR CONDITIONS. FOG SHOULD BE SHALLOW AND SHOULD BURN OFF BY
13Z. SOME DIURNAL CUMULUS CLOUDS ALONG WITH A MIX OF SOME HIGH
CLOUDS ARE EXPECTED BY SATURDAY AFTERNOON.
OUTLOOK...THUNDERSTORMS POSSIBLE MONDAY AND TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...BINAU
SHORT TERM...BINAU
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
314 PM CDT FRI MAY 18 2012
.SHORT TERM...
QUIET CONDITIONS EXPECTED THE REMAINDER OF TODAY THOUGH WINDS WILL
REMAIN BREEZY EAST OF THE DRYLINE. DRYLINE HAS PUSHED ALMOST TO THE
27/87 CORRIDOR EARLY THIS AFTERNOON THOUGH BEST CONVERGENCE REMAINS
SOME 60 OR SO MILES EAST ACROSS OUR CWFA. UPPER LEVEL TROUGH AXIS
STRETCHING FROM SRN ID TO NWRN SONORA WILL PIVOT AND BECOME
NEGATIVELY TILTED INTO SATURDAY AS THE BULK OF THE ENERGY ENTERS THE
CENTRAL PLAINS. IN RESPONSE 40-50KT LLJ WILL ASSIST IN ENHANCED
SHALLOW MOISTURE ADVECTION OVERNIGHT AND SATURDAY MORNING ACROSS THE
REGION. MIGHT SEE SOME LOW CLOUDS FORM INVOF THE LLJ IN THE MOIST
SECTOR. DRYLINE SHOULD QUICKLY MIX EASTWARD TO THE ESCARPMENT
/POSSIBLY FURTHER EAST/ ONCE AGAIN THOUGH THIS TIME...WITH THE ADDED
MOISTURE IN PLACE...AND FAVORABLE RR QUADRANT OF JETLET SOUTHEAST OF
THE TROUGH TO OUR NORTHWEST...WE COULD SEE SHOWERS AND THUNDERSTORMS
DEVELOP ALONG/E OF DRYLINE. AT THIS POINT...ACTIVITY LOOKS AS IF IT
WILL BE HIGH BASED WITH CONDITIONAL SUPPORT FOR SEVERE WIND GUSTS
AND LOW END SEVERE HAIL.
&&
.LONG TERM...
EXTENDED FORECAST IS PLAGUED WITH A LINGERING FRONTAL PASSAGE...CHANCES
FOR PRECIP WITH ACCOMPANIED COOLER TEMPS...FOLLOWED BY A RETURN OF
ABOVE SEASONAL NORMS.
UA TROUGH CURRENTLY ACROSS EASTERN NEVADA/WESTERN UTAH WILL EJECT
ENE TO ACROSS THE CENTRAL PLAINS TOMORROW EVENING...WITH ITS
ASSOCIATED COLD FRONT SURGING SOUTH ACROSS THE NORTHERN SOUTH PLAINS
LATE TOMORROW NIGHT/EARLY SUNDAY MORNING. THE SPATIAL AND TEMPORAL
DISTRIBUTION OF THE FROPA IS A BIT QUESTIONABLE AS THE NAM SOLUTION
QUICKLY PUSHES IT SOUTH OF THE CWA BY SUNDAY MORNING...VERSUS
STALLING IT ACROSS THE SOUTHERN ZONES SUNDAY EVENING PER THE GFS.
CONCURRENTLY...A DRYLINE DISPLACED ACROSS THE ROLLING PLAINS WILL BE
QUICKLY SHUNTED WEST OF THE FA THANKS TO THE FRONTAL INTRUSION...BUT
NOT BEFORE FORECAST SOLUTIONS DISPLAY PRECIP DEVELOPING ALONG THE
INTERSECTION OF THE FROPA AND DRYLINE ACROSS WESTERN
OKLAHOMA...EASTERN PANHANDLES AND FAR NERN SOUTH PLAINS LATE TOMORROW
NIGHT/EARLY SUNDAY MORNING. CURRENT THINKING IS THAT BETTER CHANCES
FOR PRECIP WILL EXIST ACROSS THE EASTERN PANHANDLES AND WESTERN
OKLAHOMA NEAREST TO THE BEST SYNOPTIC LIFT. HOWEVER...PROGGED PWATS
OVER 1.00 INCH AND MESOSCALE LIFTING MECHANISMS SUCH AS THE COLD
FRONT AND RETREATING DRYLINE CAN NOT BE OVERLOOKED...AND WILL
THEREFORE MAINTAIN SLIGHT CHANCE POPS ACROSS THE NERN ZONES TOMORROW
NIGHT.
SFC RIDGE NE OF THE REGION WILL INDUCE SFC WINDS TO VEER TO A
NORTHEAST/UPSLOPE WIND COMPONENT THROUGHOUT THE DAY ON SUNDAY...AND
THUS PROMOTE MOISTENING LOW LEVELS /PWATS OVER 1.00 INCH/. NEAR
ZONAL FLOW ALOFT WILL ENSUE...HOWEVER THIS DOES NOT NECESSARILY
EQUATE QUIET WEATHER CONDITIONS GIVEN THE DEPICTION OF THE FROPA PER
THE GFS. AS SUCH...THIS WOULD SUGGEST PRECIP INCREASING IN COVERAGE
FROM EAST TO WEST...WHICH WOULD HAVE A DIRECT EFFECT ON DAYTIME
HIGHS DUE TO THE INCREASED CLOUD COVER. THE NAM SOLUTION IS DRY GIVEN
THE FARTHER SOUTHERN DISPLACEMENT OF THE FRONT...HOWEVER THE ECMWF
HINTS AT PRECIP DEVELOPING ACROSS THE EASTERN AND SOUTHERN ZONES
SUNDAY NIGHT NEAR THE STALLED BOUNDARY. WILL THEREFORE LEAN TOWARDS
A BLEND OF THE GFS AND ECMWF IN REGARD TO THE FROPA BEHAVIOR LEADING
TOWARDS TEMPS IN MID 70S NW TO MID 80S SE...AND MAINTAIN A GRADUAL
INCREASE IN POPS THROUGHOUT THE DAY SUNDAY.
THE COLD FRONTAL BOUNDARY THAT IS STALLED ACROSS THE SOUTHERN ZONES
OR JUST SOUTH OF THE CWA WILL RETREAT NORTH AS A WARM FRONT LATE
SUNDAY NIGHT/EARLY MONDAY MORNING. LONG TERM SOLUTIONS REVEAL
PRECIP ACROSS THE NORTHERN ZONES ON MONDAY ALONG THE RETREATING
FRONT...BUT DRYING CONDITIONS /PWATS DROPPING BELOW 1.00 INCH/ AND
WARMER TEMPS /LOWER 90S/ WILL COMMENCE BY TUESDAY AS UA RIDGING
TRANSLATES EAST ACROSS THE REGION. THEREAFTER...BOTH THE GFS AND
ECMWF SOLUTIONS ARE SIMILAR IN DEPICTING A BROAD UA LOW BECOMING
QUASI-STATIONARY NEAR NORTHWESTERN NEVADA THURSDAY NIGHT/FRIDAY
MORNING. THIS WILL PROMOTE SW FLOW ALOFT...THE RETURN OF THE
SLOSHING DRYLINE AND PERHAPS INCREASING CHANCES FOR PRECIP AS GULF
MOISTURE RETURNS TO THE REGION /THE PREVIOUS MODEL RUNS WERE
DIFFERENT IN REGARD TO THE SYNOPTIC FLOW/. WILL MAINTAIN
MENTIONABLE POPS ONLY ON SATURDAY AND SUNDAY WHERE THE POTENTIAL
FOR STORMS TO APPROACH SEVERE LEVELS EXIST GIVEN SFC BASED CAPE OF
1000-2000 J/KG...AND SILENT POPS THEREAFTER DUE TO FORECAST MODELS
STRUGGLING WITH THE EXTENDED SYNOPTIC PATTERN.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 57 88 51 76 53 / 0 0 10 20 20
TULIA 62 90 55 74 56 / 0 10 10 20 20
PLAINVIEW 64 92 56 75 56 / 0 10 10 20 20
LEVELLAND 64 91 56 79 57 / 0 10 10 20 30
LUBBOCK 64 93 58 79 59 / 0 10 10 20 30
DENVER CITY 63 91 56 82 58 / 0 10 10 20 30
BROWNFIELD 64 93 59 82 59 / 0 10 10 20 30
CHILDRESS 66 96 63 79 63 / 10 20 20 20 30
SPUR 63 96 63 82 61 / 0 20 20 30 30
ASPERMONT 65 93 64 85 65 / 0 10 10 20 30
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26/29
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
526 PM CDT FRI MAY 18 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
CENTERED OVER SOUTH DAKOTA AND A WARM FRONT LIFTING NE OVER LAKE
SUPERIOR. WITHIN THE WARM SECTOR...MOSTLY CLEAR SKIES EXIST ACROSS
THE FORECAST AREA WITH ONLY THIN CIRRUS DRIFTING OVERHEAD...AHEAD OF
A SHORTWAVE OVER THE PLAINS. DESPITE AWFULLY DRY AIR JUST ABOVE THE
SURFACE ON THE 12Z GRB RAOB...DEWPOINTS HAVE ACTUALLY BEEN
INCREASING THIS AFTERNOON AND HUMIDITY LEVELS HAVE BOTTOMED OUT IN
THE MID 20 PERCENT RANGE OVER CENTRAL WISCONSIN. WITH THE UPSTREAM
LOW PRESSURE BARELY REACHING THE MISSISSIPPI RIVER TOMORROW...TEMPS
AND HUMIDITIES ARE THE MAIN FORECAST CONCERNS.
TONIGHT...MID AND UPPER RIDGE AXIS WILL SLOWLY MOVE TO THE CENTRAL
GREAT LAKES TONIGHT...WHILE A WEAK SHORTWAVE OVER THE PLAINS MOVES
NE TO THE NORTHERN MISSISSIPPI VALLEY. VERY LITTLE THREAT OF PRECIP
WITH THIS WAVE DUE TO THE ABUNDANCE OF DRY AIR THROUGH THE
COLUMN...AND DO NOT EXPECT MORE THAN CIRRUS FLOATING OVERHEAD.
OTHERWISE...HIGH PRESSURE WILL SHIFT TO THE EAST COAST AND A COLD
FRONT WILL DRIFT ACROSS THE NORTHERN PLAINS. THE PRESSURE GRADIENT
WILL TIGHTEN A BIT TONIGHT WHICH WILL KEEP A SOUTHERLY BREEZE IN
PLACE. AS A RESULT...WILL SEE WARMER LOWS INTO THE MIDDLE AND UPPER
50S AT MOST LOCATIONS.
SATURDAY...THE UPSTREAM FRONT WILL MOVE INTO WESTERN WISCONSIN BY
LATE IN THE AFTERNOON. SOUTHERLY FLOW WILL STRENGTHEN A BIT BUT
WILL CONTINUE TO RECYCLE A DRY AIRMASS FROM THE DEPARTING HIGH
ACROSS THE STATE. SHOULD FEEL MORE HUMIDITY HOWEVER...AS THE DRY
AIRMASS MODIFIES AND MOISTURE GETS PULLED NORTHWARD AHEAD
OF THE FRONT. AFTER A WARMER START TO THE DAY...925MB TEMPS ARGUE
FOR HIGHS IN THE MIDDLE 80S AT MOST LOCATIONS INLAND FROM LAKE
MICHIGAN UNDER MOSTLY SUNNY CONDITIONS.
.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY. SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH A SLOW MOVING COLD FRONT ARE THE
MAIN CONCERN FOR THE EARLY PART OF THIS FORECAST. THE ECMWF IS
STILL SLOWER THAN THE GFS BUT IS IT FASTER THAN YESTERDAY.
POTENTIAL FOR SEVERE WEATHER WILL LIKELY HINGE ON HOW WARM IT GETS
BEFORE CLOUDS ARRIVE. INSTABILITY APPEARS MODEST AND THERE ISN/T
MUCH DIRECTIONAL SHEAR. SO IT DOESN/T LOOK LIKE A BIG SEVERE
WEATHER DAY BUT WOULDN/T DOUBT ISOLATED STRONG OR SEVERE STORMS.
SHOWERS SHOULD END MONDAY AS FRONT EXITS THE REGION. THEN NICE
SEASONABLE WEATHER EXPECTED MONDAY NIGHT THROUGH THURSDAY WITH
SURFACE HIGH PRESSURE IN CONTROL.
BETTER GET THE AIR CONDITIONING WORKING IF THE ECMWF IS RIGHT
ABOUT NEXT SATURDAY AND SUNDAY. IT BUILDS A 591 DM UPPER RIDGE
OVER ILLINOIS. THIS WOULD BRING 90 DEGREE TEMPERATURES TO MUCH OF
OUR AREA WITH 60F DEW POINTS. THE GFS IS FURTHER EAST WITH THE
UPPER RIDGE SO WE MAY BE POSITIONED NEAR THE RING OF FIRE OF
CONVECTIVE COMPLEXES WHICH WOULD KEEP TEMPERATURES DOWN A BIT.
&&
.AVIATION...FOR 00Z TAF ISSUANCE. VFR CONDITIONS EXPECTED
THROUGHOUT. DECOUPLING THIS EVENING WL ALLOW SOME WIND SHEAR TO
DEVELOP...BUT SITN IS MARGINAL FOR INCLUSION OF LLWS IN THE TAFS.
WL KEEP LLWS FOR THE THE WRN TAF SITES...BUT TONE DOWN A BIT FM
PREV FCST.
SKOWRONSKI
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
243 PM CDT FRI MAY 18 2012
.SHORT TERM...TONIGHT AND SATURDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
CENTERED OVER SOUTH DAKOTA AND A WARM FRONT LIFTING NE OVER LAKE
SUPERIOR. WITHIN THE WARM SECTOR...MOSTLY CLEAR SKIES EXIST ACROSS
THE FORECAST AREA WITH ONLY THIN CIRRUS DRIFTING OVERHEAD...AHEAD OF
A SHORTWAVE OVER THE PLAINS. DESPITE AWFULLY DRY AIR JUST ABOVE THE
SURFACE ON THE 12Z GRB RAOB...DEWPOINTS HAVE ACTUALLY BEEN
INCREASING THIS AFTERNOON AND HUMIDITY LEVELS HAVE BOTTOMED OUT IN
THE MID 20 PERCENT RANGE OVER CENTRAL WISCONSIN. WITH THE UPSTREAM
LOW PRESSURE BARELY REACHING THE MISSISSIPPI RIVER TOMORROW...TEMPS
AND HUMIDITIES ARE THE MAIN FORECAST CONCERNS.
TONIGHT...MID AND UPPER RIDGE AXIS WILL SLOWLY MOVE TO THE CENTRAL
GREAT LAKES TONIGHT...WHILE A WEAK SHORTWAVE OVER THE PLAINS MOVES
NE TO THE NORTHERN MISSISSIPPI VALLEY. VERY LITTLE THREAT OF PRECIP
WITH THIS WAVE DUE TO THE ABUNDANCE OF DRY AIR THROUGH THE
COLUMN...AND DO NOT EXPECT MORE THAN CIRRUS FLOATING OVERHEAD.
OTHERWISE...HIGH PRESSURE WILL SHIFT TO THE EAST COAST AND A COLD
FRONT WILL DRIFT ACROSS THE NORTHERN PLAINS. THE PRESSURE GRADIENT
WILL TIGHTEN A BIT TONIGHT WHICH WILL KEEP A SOUTHERLY BREEZE IN
PLACE. AS A RESULT...WILL SEE WARMER LOWS INTO THE MIDDLE AND UPPER
50S AT MOST LOCATIONS.
SATURDAY...THE UPSTREAM FRONT WILL MOVE INTO WESTERN WISCONSIN BY
LATE IN THE AFTERNOON. SOUTHERLY FLOW WILL STRENGTHEN A BIT BUT
WILL CONTINUE TO RECYCLE A DRY AIRMASS FROM THE DEPARTING HIGH
ACROSS THE STATE. SHOULD FEEL MORE HUMIDITY HOWEVER...AS THE DRY
AIRMASS MODIFIES AND MOISTURE GETS PULLED NORTHWARD AHEAD
OF THE FRONT. AFTER A WARMER START TO THE DAY...925MB TEMPS ARGUE
FOR HIGHS IN THE MIDDLE 80S AT MOST LOCATIONS INLAND FROM LAKE
MICHIGAN UNDER MOSTLY SUNNY CONDITIONS.
.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY. SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH A SLOW MOVING COLD FRONT ARE THE
MAIN CONCERN FOR THE EARLY PART OF THIS FORECAST. THE ECMWF IS
STILL SLOWER THAN THE GFS BUT IS IT FASTER THAN YESTERDAY.
POTENTIAL FOR SEVERE WEATHER WILL LIKELY HINGE ON HOW WARM IT GETS
BEFORE CLOUDS ARRIVE. INSTABILITY APPEARS MODEST AND THERE ISN/T
MUCH DIRECTIONAL SHEAR. SO IT DOESN/T LOOK LIKE A BIG SEVERE
WEATHER DAY BUT WOULDN/T DOUBT ISOLATED STRONG OR SEVERE STORMS.
SHOWERS SHOULD END MONDAY AS FRONT EXITS THE REGION. THEN NICE
SEASONABLE WEATHER EXPECTED MONDAY NIGHT THROUGH THURSDAY WITH
SURFACE HIGH PRESSURE IN CONTROL.
BETTER GET THE AIR CONDITIONING WORKING IF THE ECMWF IS RIGHT
ABOUT NEXT SATURDAY AND SUNDAY. IT BUILDS A 591 DM UPPER RIDGE
OVER ILLINOIS. THIS WOULD BRING 90 DEGREE TEMPERATURES TO MUCH OF
OUR AREA WITH 60F DEW POINTS. THE GFS IS FURTHER EAST WITH THE
UPPER RIDGE SO WE MAY BE POSITIONED NEAR THE RING OF FIRE OF
CONVECTIVE COMPLEXES WHICH WOULD KEEP TEMPERATURES DOWN A BIT.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH AT LEAST
MIDDAY ON SATURDAY. GUSTY SOUTH-SOUTHWEST WINDS WILL CONTINUE
THROUGH EARLY THIS EVENING BEFORE DIMINISHING. BUT LLWS TO DEVELOP
OVER CENTRAL AND NORTH-CENTRAL WISCONSIN TONIGHT. SOUTH WINDS WILL
BECOME GUSTY ONCE AGAIN BY LATE MORNING ON SATURDAY.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/RDM