Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/25/12
AREA FORECAST DISCUSSION
NWS DENVER CO
737 PM MDT THU MAY 24 2012
.UPDATE...RADAR SHOWING A BOUNDARY MOVING WEST ACROSS EASTERN
COLORADO. THIS IS INCREASING LOW LEVEL MOISTURE...BUT NOT DOING
MUCH TO TEMPERATURES. THE INCREASE IN MOISTURE COMBINED WITH
INCREASING LIFT HAS PRODUCED A FEW SHOWERS OVER THE EASTERN
PLAINS. WILL HAVE LOW POPS FOR MOST OF THE EASTERN PLAINS FOR
THIS. HRRR SUPPORTS THIS AS IT SHOWS ISOLATED SHOWERS THIS
EVENING. BETTER CHANCE FOR SHOWERS WILL BE OVERNIGHT IN THE FAR
NORTHEAST CORNER OF THE STATE WHERE THE BEST MOISTURE AND LIFT
WILL BE. ADJUSTED FORECASTED TO INCREASE POPS FOR THIS AND ALSO
TWEAKED THE FORECAST TO REFLECT CURRENT CONDITIONS.
&&
.AVIATION...EASTERLY WINDS WILL PREVAIL TONIGHT AND MOST OF FRIDAY
ACROSS THE DENVER AREA. WINDS MAY CYCLONE AND TURN NORTHERLY ALONG
THE FOOTHILLS. LOW CLOUDS WILL FORM 07-09Z WITH CEILINGS 2500 TO
4000 FEET. LOW CLOUDS WITH CEILINGS BELOW 6000 MAY PREVAIL THROUGH
THE DAY FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 245 PM MDT THU MAY 24 2012/
SHORT TERM...CURRENT RADAR PICTURES ARE SHOWING A BATCH OF SHOWERS
OVER NORTHERN WELD AND LOGAN COUNTIES. THESE SHOWERS ARE LIKELY
ASSOCIATED WITH THE JET MAXIMUM NOW OVER THE NORTHERN BORDER OF
COLORADO. THE SHOWERS ALONG THE CONTINENTAL DIVIDE ARE CONTINUING
AS WELL. MODELS SHOW THE JET MAXIMUM TO BE OVER SOUTHERN WYOMING AT
06Z TONIGHT. THE FLOW ALOFT OVER THE FORECAST AREA IS PROGGED TO BE
SOUTHWESTERLY ON FRIDAY WITH SPEEDS IN THE 70 TO 90 KNOT RANGE.
BOTH THE NAM AND GFS SHOW WEAK UPWARD QG VERTICAL VELOCITY FOR THE
CWA OVERNIGHT AND FRIDAY. THE LOW LEVEL PRESSURE AND WIND FIELDS
SHOW A SURGE OF UPSLOPE TO MOVE INTO THE PLAINS THIS EVENING. ON
FRIDAY...THE NAM HAS EASTERLY BOUNDARY LAYER FLOW ACROSS THE PLAINS
AND FOOTHILLS...WITH SOUTHEASTERLIES ON THE GFS. FOR MOISTURE...THE
NAM SHOWS QUITE A BIT DEVELOPING OVER THE PLAINS OVERNIGHT...THE GFS
SHOWS LESS. THAT LOW LEVEL MOISTURE STICKS AROUND ON THE NAM FOR
FRIDAY...THE GFS IS DRIER ON FRIDAY. DEW POINTS ARE PROGGED IN THE
MID 30S TO LOWER 40S FOR THE PLAINS OVERNIGHT...WITH 40S...EVEN
LOWER 50S F ON FRIDAY. THERE IS NO CAPE PROGGED FOR THE CWA
TONIGHT. BY FRIDAY AFTERNOON...THERE IS SOME OVER THE PLAINS...MORE
SO ON THE GFS. THE NAM LAPSE RATE FIELDS HAVE A STRONG LOW/MID
LEVEL STABLE LAYER OVER THE PLAINS ON FRIDAY...THE GFS HAS PRETTY
STEEP LAPSE RATES DURING THIS SAME TIME. THE QPF FIELDS HAVE A TAD
OF MEASURABLE PRECIPITATION OVER THE NORTHERN AND EASTERN BORDER
THIS EVENING...THEN A BIT MORE OVER THE NORTH HALF OF THE CWA
OVERNIGHT. ON FRIDAY...THERE IS A TAD OVER NORTHERN AND EASTERN
BORDER AGAIN. SO THE GFS AND NAM DIFFER SIGNIFICANTLY CONCERNING
THE COLD AIR SURGE...UPSLOPE...MOISTURE AND INSTABILITY. I BELIEVE A
BIT MORE IN THE NAM IN THAT IF A SURGE MOVES IN...IT USUALLY MAKES
IT TO THE FOOTHILLS ANYWAY. FOR POPS...WILL GO WITH 20-40%S
OVERNIGHT...MAINLY OVER THE NORTHERN AND EASTERN BORDER AREAS. ON
FRIDAY...WILL GO WITH 10-20%S FOR THE PLAINS AND FOOTHILLS. IT MAY
BE TO STABLE FOR STORMS HOWEVER. FOR TEMPERATURES...FRIDAY`S HIGHS
ON THE NAM ARE SIMILAR TO TODAY`S WITH THE NORTHEAST CORNER BEING
COLDER. THE GFS SHOWS A 5-10 C WARM-UP FROM TODAY`S. AGAIN...WILL
LEAN MORE TOWARDS THE NAM.
LONG TERM...FOR FRIDAY EVENING...FLOW ALOFT TO BECOME SOUTH
SOUTHWEST AS UPPER TROUGH DIGS INTO GREAT BASIN. SOME WEAK LIFT
PROGGED OVER REGION...ENOUGH TO MAINTAIN A SLIGHT CHANCE OF
THUNDERSTORMS WITH THE BEST CHANCE NEAR THE WYOMING BORDER. BOTH NAM
AND GFS CONTINUE TO SHOW SURFACE HIGH OVER CENTRAL PLAINS ADVECTING
LOW LEVEL MOISTURE WESTWARD TOWARD THE FOOTHILLS AFTER MIDNIGHT.
BOTH BOUNDARY LAYER PROGS SHOW POTENTIAL FOR STRATUS AND AREAS OF
FOG ACROSS MUCH OF THE PLAINS OVERNIGHT. THIS ALREADY IN GRIDS AND
LOOKS REASONABLE. AIRMASS LOOKS A BIT TOO STABLE FOR THUNDER IN THE
OVERNIGHT HOURS SO OPT TO DROP FROM GRIDS. SOUTHERLY SURFACE WINDS
WILL BE ON THE INCREASE SATURDAY AS FLOW ALOFT CONTINUES TO INCREASE
WITH JET EXPECTED TO PASS OVERHEAD. COULD SEE SOME GUSTS UP TO 50
MPH ACROSS PLAINS DURING THE AFTERNOON AND EARLY EVENING. FLOW TO
USHER IN WARMER AND DRIER AIR INTO THE REGION...AND COMBINING WITH
THE GUSTY WINDS...WILL ELEVATE THE FIRE DANGER ONCE AGAIN WITH
CRITICAL FIRE WEATHER CONDITIONS POSSIBLE. IT APPEARS THAT THE
RECENT BENEFICIAL PRECIPITATION HELPED INCREASED THE FUEL MOISTURES.
FOR NOW WILL BE HOLDING OFF ON ANY FIRE WEATHER HILITES. MODELS SHOW
SOME MOISTURE ALONG WITH WEAK QG ASCENT SLIDING ACROSS MOUNTAINS...
WILL KEEP A SLIGHT CHANCE OF CONVECTION THERE. AIRMASS LOOKS TOO DRY
FOR CONVECTION ACROSS PLAINS. FLOW ALOFT TO WEAKEN SATURDAY EVENING
AS UPPER TROUGH OVER GREAT BASIN BEGINS TO HEAD INTO WYOMING. SHOULD
SEE SURFACE WINDS DECREASE AS A RESULT.THERE IS SOME INCREASE IN MID
LEVEL QG ASCENT...THOUGH MOST TO REMAIN WEST AND NORTH OF THE AREA.
WILL KEEP SOME SHOWERS GOING OVER THE MOUNTAINS OVERNIGHT. LOOKS
COLD ENOUGH FOR SOME SOME OVER THE RIDGES. THE UPPER LOW TO CONTINUE
MOVING NORTHEAST INTO WYOMING SUNDAY WITH BASE OF TROUGH AFFECTING
NORTHERN COLORADO. MODELS SHOW ASSOCIATED SURFACE FRONT PUSHING
ACROSS REGION WITH COOLER AIR ALONG WITH A BIT MORE MOISTURE. BOTH
NAM AND GFS DEPICT MID LEVEL QG ASCENT OVER AREA DURING THE
MORNING...FOLLOWED QUICKLY BY SUBSIDENCE DURING THE AFTERNOON.
APPEARS BEST CHANCE FOR SHOWERS AND STORMS WILL BE IN THE HIGH
COUNTRY DURING THE MORNING...BUT WILL CONTINUE THROUGH THE DAY. WILL
MAINTAIN A DRY FORECAST FOR THE PLAINS.
ZONAL FLOW ALOFT TO PREVAIL MONDAY AND TUESDAY...WITH NEAR NORMAL
TEMPERATURES AND MAINLY DRY WEATHER. BOTH GFS AND ECMWF CONTINUE TO
SHOW FLOW ALOFT BECOMING NORTHWEST WEDNESDAY WITH UPPER TROUGH
DIGGING INTO THE CENTRAL PLAINS. BOTH MODELS ALSO SHOW MID LEVEL
SHORTWAVE AND SURFACE FRONT MOVING ACROSS AREA. COMBINATION OF THE
LIFT FROM WAVE AND UPSLOPE BEHIND FRONT COULD PROVIDE SOME
PRECIPITATION ALONG WITH COOLER TEMPERATURES. GFS LOOKS MORE ROBUST
WITH STRENGTH OF TROUGH AND AMOUNT OF UPSLOPE THUS MORE
PRECIPITATION DEPICTED. WILL CONTINUE THE SLIGHT CHANCE OF SHOWERS
AND STORMS ALONG WITH COOLER CONDITIONS. ON THURSDAY...FLOW ALOFT
ACROSS PLAINS BECOMES SOUTHEAST WITH FLOW ALOFT REMAINING NORTHWEST.
STILL ENOUGH MOISTURE AND WEAK UPSLOPE FOR SOME CHANCE OF SHOWERS
AND/OR STORMS.
AVIATION...VFR CONDITIONS ARE EXPECTED AT DIA UNTIL ABOUT 09Z.
AFTER THAT...CEILINGS COULD GET DOWN TO 3000 FEET AGL. THE WINDS
ARE WILL LIKELY GO TO UPSLOPE (030 OR 040) AROUND 03Z THIS EVENING.
HYDROLOGY...RAINFALL AMOUNTS WILL BE BE LIGHT THE NEXT 24
HOURS...NOTHING OVER A QUARTER OF AN INCH EXPECTED.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RJK
LONG TERM....D-L
UPDATE/AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
530 PM MDT THU MAY 24 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 256 PM MDT THU MAY 24 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH
EXTENDING FROM THE PACIFIC NORTHWEST ACROSS T HE NORTHERN
PLAINS...WITH WEST/SOUTHWEST FLOW OVER THE CENTRAL ROCKIES AND
CENTRAL HIGH PLAINS. A SERIES OF SHORTWAVE TROUGHS ARE CURRENTLY
TRACKING WITHIN THE MEAN FLOW WITH SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THESE FEATURES OVER NORTHERN COLORADO AND NORTH
CENTRAL NEBRASKA. A STATIONARY FRONT EXTENDS FROM EASTERN KANSAS
SOUTH INTO NORTHCENTRAL TEXAS...AND THEN NORTH INTO SOUTH-CENTRAL
COLORADO.
TONIGHT...A CLOSED LOW CENTER WITHING THE LARGE SCALE TROUGH WILL
MOVE EAST/NORTHEAST INTO THE NORTHERN PLAINS WITH LARGE SCALE
ASCENT SPREADING SOUTH AND EAST TOWARDS SOUTHWEST NEBRASKA. THE
STATIONARY FRONT TO THE SOUTH WILL BEGIN TO MOVE NORTH IN RESPONSE
TO STRENGTHENING LEE TROUGH OVER EASTERN COLORADO. A STRONG LLJ IS
ADVERTISED TO DEVELOP BY 06Z TONIGHT WHICH COULD ALSO ACT AS A
FOCUS FOR SHOWER THUNDERSTORM DEVELOPMENT OVER OUR CWA. VERY
STRONG SHEAR WILL DEVELOP OVERNIGHT ALONG WITH ELEVATED
INSTABILITY NEAR THE NOSE OF THE LLJ. BEST FORCING LOOKS TO BE
EITHER NORTH OR SOUTH OF THE CWA. IM ALSO NOT SURE ABOUT HOW MUCH
TD WILL RECOVER NORTH OF THE FRONT. I KEPT POPS IN THE SLIGHT
CHANCE/CHANCE CATEGORY...WITH BEST COVERAGE LATE TONIGHT WHEN LLJ
IS EXPECTED TO DEVELOP. THERE CONTINUES TO BE INDICATION OF FOG
DEVELOPMENT WITH EASTERLY FLOW AROUND SUNRISE TOMORROW...SO I KEPT
PATCHY FOG MENTION.
FRIDAY..SHOWER/THUNDERSTOM ACTIVITY SHOULD COME TO AN END FROM
THE SOUTHWEST TO THE NORTHEAST THROUGH THE DAY...WITH ACTIVITY
POSSIBLY LINGERING OVER NORTHERN PARTS OF THE FORECAST AREA INTO
FRIDAY EVENING. THERE IS A LARGE SPREAD IN GUIDANCE ON TIMING OF
WARM FRONT FRIDAY WITH NAM THE SLOW OUTLIER. NAM SOLUTION WOULD
KEEP STRATUS/FOG IN PLACE ALONG WITH MUCH COOLER AIRMASS.
GFS/ECMWF FAVOR THE CLEARING SOLUTION ALONG WITH MUCH WARMER
TEMPERATURES ACROSS THE SOUTHWEST..WHICH IS WHERE I LEANED THIS
FORECAST CYCLE.
FRIDAY NIGHT...PRIMARY ADJUSTMENT TO THIS PERIOD WAS TO BUMP
OVERNIGHT LOWS UP A NOTCH OR TWO WITH SOUTHERLY/SOUTHEASTERLY FLOW
IN PLACE ACROSS THE FORECAST AREA. WILL SEE SLIGHT CHANCE/CHANCE
POPS OVER THE FAR NORTHEAST PORTION OF THE FORECAST AREAS DURING
THE OVERNIGHT HOURS BEFORE SHIFTING OUT OF THE AREA BY AROUND
SUNRISE ON SATURDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 256 PM MDT THU MAY 24 2012
ACTIVE WEATHER PATTERN SETTING UP FOR THE EXTENDED WITH A FEW
PERIODS OF STRONG TO SEVERE CONVECTION APPEARING POSSIBLE.
SATURDAY AND SATURDAY NIGHT...WARM FRONT LIFTS NORTH INTO NEBRASKA
DURING THE DAY WITH A DRYLINE SETTING UP. H85 TEMPS WARM TO AROUND
30C OVER EASTERN COLORADO WITH MID TO UPPER 20S C ELSEWHERE.
RESULT WILL BE AFTERNOON TEMPS APPROACHING THE CENTURY MARK IN A
FEW LOCATIONS. EVERYONE SHOULD SEE AT LEAST THE LOW/MID 90S.
SATURDAY LOOKS TO BE A VERY WINDY DAY ACROSS AT LEAST THE WESTERN
TWO-THIRDS OF THE FORECAST AREA WITH LATEST GUIDANCE HINTING AT
THE POTENTIAL FOR BORDERLINE HIGH WIND WARNING GUSTS. CONSIDERED
HOISTING A HIGH WIND WATCH FOR WESTERN HALF BUT OPTED TO HOLD OFF
AND ALLOW OVERNIGHT SHIFT TO HAVE ANOTHER RUN OF NWP GUIDANCE. AT
THE LEAST...APPEARS AS THOUGH A WIND ADVISORY WILL BE NEEDED FOR
MUCH OF THE AREA. DEW POINTS WILL TANK ACROSS THE WEST WHICH WILL
RESULT IN RH VALUES FALLING TO AROUND 10 PERCENT. FUELS PAGE
INDICATES SUFFICIENT GREEN-UP IS ONGOING WHICH MAY LIMIT FIRE
WEATHER POTENTIAL BUT THIS IS ALSO SOMETHING THAT WILL NEED TO
BE MONITORED OVER THE NEXT FEW FORECAST SHIFTS. DISCREPANCIES DO
EXIST IN THE PLACEMENT OF THE DRYLINE BUT A SLIGHT CHANCE FOR
CONVECTION OVER THE EASTERN HALF OF THE FORECAST AREA APPEARS
JUSTIFIED. GIVEN INVERTED-V NATURE OF VERTICAL SOUNDING
PROFILES...ANY STORM WHICH DEVELOPS WILL HAVE THE POTENTIAL TO
PRODUCE STRONG WIND GUSTS. LARGE HAIL WILL ALSO BE POSSIBLE THOUGH
SHEAR PROFILES DON`T BECOME STRONGLY FAVORABLE UNTIL AFTER 00Z.
SUNDAY AND SUNDAY NIGHT...POTENT MID/UPPER TROUGH WILL BEGIN TO
TRANSLATE ACROSS THE GREAT BASIN/ROCKIES ON SUNDAY WITH INCREASING
FORCING FOR ASCENT AS THE DAY PROGRESSES. PRIMARY QUESTION WILL BE
THE ULTIMATE LOCATION OF THE DRYLINE. EAST OF THE DRYLINE...DEW
POINT WILL SURGE INTO THE UPPER 50S AND PERHAPS EVEN THE LOWER
60S. DEEP LAYER SHEAR OF 40 TO 50 KTS WILL AID IN UPDRAFT
ORGANIZATION WHILE STRONG LOW LEVEL PARAMETERS WOULD ALSO SUPPORT
A TORNADO THREAT. GREATEST THREAT IS CURRENTLY INDICATED TO BE
GENERALLY ALONG AND EAST OF THE HIGHWAY 83 CORRIDOR. INTERESTED
PARTIES WILL WANT TO CLOSELY MONITOR THE LATEST FORECAST
INFORMATION.
MONDAY THROUGH TUESDAY...PRIMARY MID/UPPER LOW SHIFTS EASTWARD
ACROSS THE SOUTHERN PRAIRIE PROVINCES OF CANADA MONDAY INTO
TUESDAY MORNING WITH WEAK RIDGING/QUASI-ZONAL FLOW ACROSS THE
CENTRAL HIGH PLAINS. RESULT SHOULD BE SEASONABLE TEMPS WITH DRY
CONDITIONS EXPECTED UNTIL AT LEAST TUESDAY AFTERNOON WHEN A
SHORTWAVE TROUGH MOVES ACROSS THE AREA.
WEDNESDAY THROUGH THURSDAY...MID/UPPER RIDGING BUILDS ACROSS THE WESTERN
CONUS WITH A NEGATIVELY TILTED SHORTWAVE TROUGH AND AN ASSOCIATED
SURFACE COLD FRONT DROPPING SOUTHEAST ACROSS THE DAKOTA AND
NEBRASKA. BROAD SCALE FORCING FOR ASCENT INCREASES BY WEDNESDAY
AFTERNOON WHICH WILL AID IN THE DEVELOPMENT OF CONVECTION OVER
PRIMARILY SOUTHWEST NEBRASKA AND NORTHWEST KANSAS. WILL CARRY
PRIMARILY CHANCE POPS DURING THIS TIME PERIOD WITH MUCH COOLER AIR
FILTERING INTO THE REGION BEHIND THE FRONT ON THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 515 PM MDT THU MAY 24 2012
THUNDERSTORMS HAVE THUS FAR FAILED TO DEVELOP WITH JUST SOME
SCATTERED ALTOCU ACROSS THE AREA. MODELS HAVE INITIALIZED FAR TOO
WET AND AM SKEPTICAL OF ANY PRECIPITATION IN THE PERIOD WITH LACK
OF SYNOPTIC SCALE FORCING. NONETHELESS...AS THE LLJ GETS GOING
AFTER MIDNIGHT COULD BE SOME ISOLATED ELEVATED CONVECTION. LOW
LEVEL EASTERLY FLOW OVERNIGHT WOULD SEEM TO SUPPORT MENTION OF
STRATUS AND/OR FOG...BUT WITH DEW POINTS CURRENTLY IN THE 30S AND
40S IT WILL BE DIFFICULT TO COOL OFF ENOUGH TO ACHIEVE SATURATION.
&&
.CLIMATE...
ISSUED AT 245 AM MDT THU MAY 24 2012
RECORD AND NEAR RECORD HIGH TEMPERATURES EXPECTED SATURDAY.
GOODLAND.....97 IN 2006
HILL CITY....99 IN 1912
MCCOOK.......98 IN 1967
BURLINGTON...95 IN 1942
YUMA.........96
TRIBUNE......101
COLBY........98
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR/FOLTZ
LONG TERM...FOLTZ
AVIATION...024
CLIMATE...007
AREA FORECAST DISCUSSION
NWS GOODLAND KS
227 PM MDT WED MAY 23 2012
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 1245 PM MDT WED MAY 23 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH
ACROSS THE NORTHERN ROCKIES...WITH WEST/SOUTHWEST FLOW ACROSS THE
INTER-MOUNTAIN WEST INTO THE CENTRAL HIGH PLAINS. AT THE SURFACE A COLD
FRONT HAS STALLED OVER WESTERN KANSAS...CURRENTLY ACROSS THE EASTERN
PART OF THE CWA.
A SHORTWAVE TROUGH CURRENTLY OVER THE GREAT BASIN WILL MOVE
EAST-NORTHEAST ACROSS NORTH CENTRAL COLORADO AND SOUTHWEST NEBRASKA
TONIGHT. SHOWERS/THUNDERSTORMS HAVE ALREADY DEVELOPED AHEAD OF THIS
FEATURE ALONG THE FRONT RANGE INTO SOUTHEASTERN WYOMING. THIS
ACTIVITY WILL SPREAD SOUTH AND EAST OVER OUR CWA LATER THIS
AFTERNOON...WITH COVERAGE INCREASING ACROSS THE NORTHERN PART OF OUR
FORECAST AREA THROUGH 06Z. CONVERGENCE ZONE ALONG AND NORTH OF
STALLED FRONT COULD ACT AS A FOCUS FOR EARLIER THUNDERSTORM
INITIATION LATER THIS AFTERNOON AND EVENING...HOWEVER THIS IS
REMOVED FROM LARGE SCALE ASCENT ASSOCIATED WITH SHORTWAVE SO
COVERAGE SHOULD BE LIMITED ACROSS THE SOUTH. VERY STRONG SHEAR IS
PRESENT ACROSS THE CWA...WITH INSTABILITY DECREASING THE FURTHER
NORTH IN THE CWA WHERE TD VALUES IN THE 30-40F RANGE HAVE ADVECTED
IN BEHIND THE FRONT. SEVERE CONVECTION SHOULD BE LIMITED TO THE I-70
CORRIDOR THROUGH EARLY EVENING WHERE THE BEST OVERLAP BETWEEN
SHEAR/INSTABILITY IS EXPECTED. LATER TONIGHT ELEVATED INSTABILITY
COULD COMBINE WITH STRONG UPPER LEVEL DYNAMICS ASSOCIATED WITH THE
SHORTWAVE ACROSS SOUTHWEST NEBRASKA TO BRING ADDITIONAL SEVERE
CHANCES. SUBSIDENCE QUICKLY BUILDS IN BEHIND DEPARTING SHORTWAVE
TROUGH AFTER 06Z...WITH COVERAGE DECREASING FROM THE SOUTHWEST TO
THE NORTHEAST THROUGH SUNRISE THURSDAY.
.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 224 PM MDT WED MAY 23 2012
THURSDAY-THURSDAY NIGHT...PV ANOMALY WILL LIFT TO THE NORTH AND EAST
OF THE AREA FAIRLY QUICKLY DURING THE MORNING HOURS...WITH MID LEVEL
FRONTOGENESIS QUICKLY DIMINISHING AND DEEP LAYER DIV Q FIELDS
INDICATE FAIRLY STRONG LARGE SCALE FORCING FOR SUBSIDENCE OVER THE
AREA. STILL HAVE A FEW TIMING CONCERNS THOUGH...AND THINK HOLDING
ONTO SOME SMALL POPS WARRANTED FOR AT LEAST THE FIRST FEW HOURS OF
THE PERIOD. SOUNDINGS SUGGEST THAT WEAK INSTABILITY WILL LINGER
ACROSS MUCH OF THE AREA THROUGH THE DAY...AS DIFFERENTIAL TEMP
ADVECTION SHOULD LEAD TO THE DEVELOPMENT OF SHALLOW SFC BASED
INSTABILITY WITH EQUILIBRIUM LEVELS LESS THAN H5 AT MANY LOCATIONS.
ALTHOUGH SUBSIDENCE DIMINISHES IN THE AFTERNOON ACROSS SOUTHERN HALF
OF CWA...THINKING ANY AFTERNOON SHOWERS WILL BE STRONGLY DIURNALLY
DRIVEN AND THINK OVERALL COVERAGE WILL BE FAIRLY LOW THROUGH THE
EARLY EVENING. LARGE SCALE ASCENT WILL ONCE AGAIN WITH STRONG LOW
LEVEL WAA DEVELOPING IN RESPONSE TO H3 JET STREAK LIFTING NORTH INTO
SOUTHERN SOUTH DAKOTA. SEEMS LIKE RECENT SUITE OF MODELS NOT ALL
THAT OPTIMISTIC ABOUT BREAKING OUT PRECIPITATION OVERNIGHT...BUT
GIVEN STRONG AND PERSISTENT WAA/ISENTROPIC FORCING STRONG MOISTURE
TRANSPORT ABOVE THE SFC...AND SMALL CONDENSATION PRESSURE DEFICITS
IN AREA OF NEGATIVE THETA E LAPSE RATES...THINK THE THREAT FOR
SHOWERS AND STORMS WILL BE THERE DESPITE CURRENT MODEL QPF OUTPUT.
FRIDAY-SATURDAY...WARM FRONT WILL SLOWLY LIFT TO THE NORTH THROUGH
THE PERIOD AND WILL NOT ONLY PLAY A BIG ROLE ON POTENTIAL FOR
THUNDERSTORMS...IT WILL ALSO HAVE A LARGE ROLE IN TEMPERATURE
FORECAST AS POSSIBILITY EXISTS FOR A PRETTY SHARP GRADIENT WITH
TEMPS ON FRIDAY. SREF PLUME DATA INDICATING NEARLY A 20 DEGREE
SPREAD IN TEMPS FOR MOST LOCATIONS...WITH ABOUT EQUAL CLUSTERING ON
EITHER SIDE...MAINLY ON FRIDAY. PLAN ON KEEPING NEAR MEAN VALUES FOR
FRIDAY...ALTHOUGH THERE IS MUCH MORE AGREEMENT ON VERY WARM TEMPS ON
SATURDAY AND HAVE WARMED TEMPS ACCORDINGLY.
GIVEN EXPECTED PRESSURE FALL PATTERN AROUND AREA AND LARGE SCALE
FORCING FOR ASCENT BECOMING MAXIMIZED WELL TO THE WEST OF THE
AREA...DO NOT ANTICIPATE MUCH OF A NORTHERN MOVEMENT OF THE
FRONT...WITH BULK OF CWA REMAINING CLOUDY AND COOL THROUGH THE DAY.
THINK THUNDERSTORMS WILL LIKELY BE ONGOING THROUGH THE MORNING HOURS
AS PREVIOUSLY MENTIONED WAA PATTERN REMAINS IN PLACE THROUGH THE
MORNING HOURS...BEFORE LARGE SUBSIDENCE INVERSION STRENGTHENS DURING
THE AFTERNOON SHARPLY INCREASING CINH PROFILES AND ADVECTING MUCH
DRIER AIR INTO THE AREA. MODELS CONTINUE TO PRODUCE LIGHT
PRECIPITATION AFTER THIS POINT...BUT SOUNDINGS LOOK LIKE ANY
PRECIPITATION PROCESSES IN THE LATE AFTERNOON OR EVENING LOOK TO BE
VERY SHALLOW/DRIZZLE TYPE PROCESSES AND DO NOT PLAN ON GOING ALONG
WITH HIGHER GUIDANCE POPS AT THIS TIME. APPEARS TO BE LOTS OF
INSTABILITY DURING THE LATE AFTERNOON AND EVENING ALONG/NORTH OF
FRONT...BUT CINH LOOKS VERY STRONG AND GIVEN RIDGING ALOFT DO NOT
THINK THIS WILL BE OVERCOME.
ON SATURDAY...EXPECT WINDY TO VERY WINDY CONDITIONS TO DEVELOP
ACROSS MUCH OF THE AREA DURING THE AFTERNOON WITH STRONGEST WINDS
BEHIND DRYLINE IN EASTERN COLORADO...WHERE DEEP MIXED LAYER SHOULD
TAP INTO STRONG FLOW ALOFT. WITH TEMPS IN THE 90S...WIND GUSTS
APPROACHING 50 KTS AND MIXED TDS SUGGESTING A RAPID DROP OFF IN
DEWPOINTS...POTENTIAL EXISTS FOR EXTREMELY CRITICAL FIRE WX
CONDITIONS TO DEVELOP. IT IS A BIT TOO FAR IN THE FUTURE TO ISSUE
ANY HIGHLIGHTS AT THIS POINT...BUT POTENTIAL FOR FIRE WEATHER AND
SIGNIFICANT WINDS IS INCREASING. OTHERWISE...WARM FRONT WILL LIFT TO
THE NORTH OUT OF THE AREA DURING THE MORNING HOURS WITH ANY
POTENTIAL FOR AFTERNOON THUNDERSTORMS ALONG DRYLINE DURING THE LATE
AFTERNOON. WITH DEEP MIXING AND BULK OF PRESSURE FALLS TO THE NORTH
OF THE AREA...WOULD EXPECT DRYLINE TO MIX EASTWARD WITH BULK OF CWA
IN DRY SECTOR. ENOUGH SPREAD EXISTS TO WARRANT A MORE BROAD BRUSHED
APPROACH TO CHANCES ATTM THOUGH AND WITH STRONG FLOW ALOFT THERE
WILL BE POTENTIAL FOR AT LEAST A FEW STRONG/SEVERE HIGH BASED STORMS
IN THE AFTERNOON.
IN THE EXTENDED (SAT NIGHT-WEDNESDAY)...ACTIVE WEATHER PATTERN
EXPECTED THROUGH THE PERIOD AS MEDIUM RANGE MODELS SHOWING
REASONABLE AGREEMENT IN DEVELOPMENT OF STRONG TROUGH/AMPLIFIED
PATTERN ACROSS THE PLAINS THROUGH THE WEEKEND...FOLLOWED BY MORE
ZONAL FLOW ALOFT DURING THE BEGINNING OF THE WEEK. WHILE 06Z GEFS
DATA SHOWS A RELATIVELY CONSISTENT PATTERN WITH LARGE TROUGH
IMPACTING THE AREA DURING THE WEEKEND...MODEL SPREAD/UNCERTAINTY
INCREASES DURING THE LATER HALF AS THERE APPEARS TO BE A DECENT
AMOUNT OF DISCREPANCY WITH SMALL SCALE FEATURES. BEST CHANCE FOR
PRECIPITATION WILL LIKELY BE ON SUNDAY AFTERNOON AS COLD FRONT
SLOWLY MOVES ACROSS THE AREA PROVIDING AMPLE FORCING TO FOCUS
THUNDERSTORM DEVELOPMENT. WITH LIGHT EASTERLY/UPSLOPE FLOW AND
SEVERAL FAST MOVING SHORT WAVE TROUGHS MOVING THROUGH ZONAL
FLOW...PRECIP CHANCES WILL CONTINUE THROUGH THE MIDDLE OF THE WEEK.
ASIDE FROM TIMING WITH FROPA ON SUNDAY BRINGING THE POTENTIAL FOR
ONE MORE VERY WARM DAY...LOOKS LIKE COOLER CONDITIONS WILL PREVAIL
THROUGH THE START OF THE WEEK AS LIGHT EASTERLY FLOW WILL PREVAIL
BEHIND COLD FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1107 AM MDT WED MAY 23 2012
VFR CONDITIONS SHOULD PREVAIL AT BOTH KGLD AND KMCK THROUGH THE
TAF PERIOD. A COLD FRONT HAS DROPPED SOUTH OF BOTH TERMINALS.
WINDS HAVE INCREASED BEHIND THIS FRONT OUT OF THE N-NE TO 15-20KT
GUSTING 25-30KT. A DISTURBANCE WILL MOVE FROM NORTHEASTERN
COLORADO ACROSS SOUTHWEST NEBRASKA OVERNIGHT TONIGHT. SHOWERS AND
THUNDERSTORMS WILL DEVELOP TOWARDS BOTH TERMINALS...WITH THE BEST
CHANCES OVER KMCK 04Z-11Z. CHANCES ARE LOWER AT KGLD...THOUGH
THERE IS ENOUGH OF A CHANCE THAT THUNDERSTORMS COULD TRACK JUST
NORTH OF THE TERMINAL TO CARRY A VCTS GROUP LATE THIS AFTERNOON
THOUGH 08Z. SUB VFR CONDITIONS WILL BE POSSIBLE IF A STRONGER
STORM WERE TO PASS OVER EITHER TERMINAL. DRY CONDITIONS AND
W-NW WINDS AROUND 12KT SHOULD PREVAIL BY SUNRISE AT BOTH TERMINALS.
&&
.FIRE WEATHER...
ISSUED AT 224 PM MDT WED MAY 23 2012
VERY WINDY CONDITIONS...WITH GUSTS IN EXCESS OF 50 MPH
POSSIBLE...ARE EXPECTED ACROSS A LARGE PORTION OF THE AREA ON
SATURDAY. AFTERNOON HUMIDITIES WILL FALL TO AROUND 10 PERCENT
ACROSS PORTIONS OF EASTERN COLORADO AND ADJACENT AREAS DURING THE
AFTERNOON AS THE WINDS INCREASE. THE COMBINATION OF VERY DRY AND
VERY WINDY CONDITIONS WILL BRING THE POTENTIAL FOR EXTREMELY
CRITICAL CONDITIONS ON SATURDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JRM
AVIATION...DR
FIRE WEATHER...JRM
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
234 PM CDT WED MAY 23 2012
...UPDATE TO LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1204 PM CDT WED MAY 23 2012
AT 12Z WEDNESDAY A 700MB ELEVATED MIXED LAYER EXTENDED FROM THE
PANHANDLE OF OKLAHOMA INTO EXTREME SOUTHWEST NEBRASKA. SOME 700MB
MOISTURE WAS LOCATED JUST NORTHWEST OF THIS ELEVATED MIXED LAYER
FROM NORTHWEST COLORADO INTO THE PANHANDLE OF NEBRASKA. A SURFACE
AND 850MB LOW WAS LOCATED UNDER THIS WARM LAYER IN NORTHWEST
KANSAS WITH A DRYLINE EXTENDING SOUTH INTO THE PANHANDLE OF TEXAS.
A SURFACE COLD FRONT STRETCHED FROM EASTERN NEBRASKA INTO EASTERN
COLORADO. ACROSS THE NORTHWEST UNITED STATES A 500MB THROUGH WAS
LOCATED ACROSS MONTANA AND IDAHO WITH AN UPPER LEVEL JET EXTENDING
FROM NORTHERN CALIFORNIA INTO NORTHWEST COLORADO. 100-120METER
HEIGHT FALLS WERE PRESENT ACROSS NORTHWEST COLORADO AND WYOMING
AND THIS WAS LOCATED NEAR THE LEFT EXIT REGION OF THE UPPER LEVEL
JET.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 142 PM CDT WED MAY 23 2012
NAM, RAP, AND HRRR WERE IN DECENT AGREEMENT WITH COLD FRONT
EXTENDING FROM NORTH CENTRAL KANSAS INTO EXTREME SOUTHWEST KANSAS
LATE THIS AFTERNOON AND EARLY THIS EVENING. THIS FRONT WILL BE
LOCATED UNDER +14C TO +16C 700MB TEMPERATURES. IN ADDITION THE
BETTER LOW LEVEL MOISTURE IS STILL FORECAST TO BE LOCATED ACROSS
CENTRAL KANSAS AND FROM NORTHWEST KANSAS INTO SOUTH CENTRAL
NEBRASKA. BASED ON MODEL SOUNDINGS THE WARM MID LEVEL TEMPERATURES
LATE TODAY/EARLY TONIGHT APPEARS TO SERVE AS A CAP ACROSS MOST OF
SOUTHWEST KANSAS. THE POSSIBLE EXCEPTION WILL BE NEAR AND NORTH OF
INTERSTATE 70 IN NORTH CENTRAL KANSAS WERE BETTER LOW LEVEL
FRONTOGENESIS AND MOISTURE WILL BE PRESENT. IN ADDITION THIS WILL
BE NEAR THE NORTHERN EDGE OF THE WARM MID LEVEL TEMPERATURES. THE
NAM EVEN SUGGESTS SOME COOLING OCCURRING IN THE MID LEVEL AFTER
21Z ALONG AND NORTH OF INTERSTATE 70. GIVEN THE COOLER MID LEVEL
TEMPERATURES, BETTER LOW LEVEL MOISTURE/FRONTOGENESIS NEAR THE
SURFACE BOUNDARY, AND CAPES EARLY TONIGHT GREATER THAN 1000 J/KG
WILL GO AHEAD AND KEEP A MENTION OF THUNDERSTORMS NEAR THE SURFACE
BOUNDARY. ALSO BASED ON 0-6KM SHEAR FORECAST TO BE AROUND 50
KNOTS ALONG WITH 1000-2000 J/KG THERE WILL BE A CHANCE FOR ANY
STORM THAT DOES DEVELOP TO BECOME SEVERE. MAIN HAZARD STILL
APPEARS TO BE HAIL UP TO HALF DOLLAR SIZE AND WINDS UP TO 60 MPH.
FURTHER WEST...THE CONVECTION DEVELOPING ACROSS NORTHEAST COLORADO IS
EXPECTED TO SPREAD EAST EARLY TONIGHT BUT STAY NORTH OF THE
INTERSTATE 70 DURING THE OVERNIGHT HOURS. THE COLD POOL THAT IS
FORECAST TO DEVELOP WITH THESE STORMS OVERNIGHT SHOULD PUSH THE
COLD FRONT SOUTH ACROSS ALL OF SOUTHWEST KANSAS AFTER MIDNIGHT. BY
EARLY THURSDAY MORNING THIS COLD FRONT IS EXPECTED TO BE LOCATED
ACROSS CENTRAL KANSAS AND NORTHERN OKLAHOMA. BOUNDARY LAYER WINDS
BEHIND THIS FRONT ARE FORECAST TO RANGE FROM 30 TO 35 KNOTS AND
GIVEN THE TIGHT PRESSURE GRADIENT BEHIND THIS FRONT THE SURFACE WINDS
MAY APPROACH ADVISORY CRITERIA FOR A FEW HOURS FOLLOWING THE
FRONTAL PASSAGE LATE TONIGHT. AT THIS TIME HAVE DECIDED TO KEEP
SUSTAINED WINDS JUST BELOW ADVISORY CRITERIA FOR A FEW HOURS
BEHIND THIS FRONT. IN ADDITION TO THE WINDS SOME LOW LEVEL
MOISTURE WILL RETURN TO NORTH CENTRAL AND SOUTHWEST KANSAS. THE
WRF AND NMM EVEN SUGGESTS SOME LIGHT PRECIPITATION WILL BE
POSSIBLE AS THE LOWER LEVELS SATURATES. AT THIS TIME GIVEN THE ISENTROPIC
DOWNGLIDE PRESENT AND DEPTH OF THE MOIST LAYER LESS THAN 3000 FEET
AM TRENDING AWAY FROM INSERTING PRECIPITATION CHANCES AFTER
MIDNIGHT.
ON THURSDAY THE GUSTY NORTHWEST WINDS WILL GRADUALLY SUBSIDE BY
MID MORNING AS THE COLD FRONT CONTINUES TO MOVE SOUTHEAST ACROSS
EASTERN KANSAS AND OKLAHOMA. IN SOUTHEAST COLORADO THIS FRONT IS
EXPECTED TO BECOME NEARLY STATIONARY DURING THE DAY WITH SOME
ISENTROPIC LIFT/WARM AIR ADVECTION DEVELOPING NORTH OF THIS
BOUNDARY BY LATE DAY. THIS MAY BRING AN INCREASE IN MID LEVEL CLOUD
COVER LATE DAY TO PORTIONS OF SOUTHWEST KANSAS BASED ON I310 AND
I315 ISENTROPIC SURFACES AND 12Z BUFR SOUNDINGS. GIVEN SOME
INCREASING CLOUDS LATE DAY AND 850MB TEMPERATURES AT 00Z FRIDAY
WILL TREND TOWARDS THE COOLER GUIDANCE IN FAR SOUTHWEST KANSAS
NEAR THE OKLAHOMA BORDER WHILE FURTHER NORTH HAVE KEPT HIGHS
CLOSER TO THE WARMER 850MB MIX DOWN TEMPERATURES.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 234 PM CDT WED MAY 23 2012
THURSDAY NIGHT:
NOT THAT IMPRESSED FOR PROSPECTS OF CONVECTION THURSDAY EVENING. SOME
ISENTROPIC LIFT IS EXPECTED ALONG THE 700 HPA BAROCLINIC BOUNDARY ACROSS
CENTRAL KANSAS. FORECAST SOUNDINGS FROM THE ECMWF/GFS SHOW THAT THERE
MAY BE SOME MID LEVEL CLOUDS, HOWEVER, THE OVERALL PROFILE IS FAIRLY
DRY AND CAPPED. WENT AHEAD AND THREW IN SOME SILENT POPS ACROSS MY NORTHERN
COUNTIES BUT DISCOUNTED THE WETTER GFS SOLUTION WHICH CONTINUES TO SUFFER
FROM OVERALL POOR SYNOPTIC PERFORMANCE. THE 4 KM NAM & ARW/NMM CORES
AREN`T TOO CONVINCING EITHER.
FRIDAY:
THE WARM SECTOR WILL CONTINUE TO SPREAD NORTHWARD DOWNSTREAM OF A SLOWLY
PROPAGATING 500 HPA TROUGH FURTHER WEST. TEMPERATURES WARM TO 33 DEG
C @ 850 HPA AND 15 DEG C & 700 HPA WITH A WELL MIXED ATMOSPHERE. HAVE
WARMED TEMPERATURES TO THE MID TO UPPER 90S DEG F ACROSS THE CENTRAL
AND SOUTHERN ZONES AS A RESULT. THE ECMWF IS VERY WARM WITH 102 DEG
F FOR DODGE CITY FRIDAY. WILL CONTINUE TO THE TREND UPWARD BUT NOT YET
BITE ON THE EXTREME. THERE COULD BE SOME CONVECTION EAST OF THE DRYLINE
FRIDAY EVENING BUT WITH SUCH WARM TEMPERATURES AT 700 HPA, WILL NOT
GO HIGHER THAN SLIGHT GIVEN THE VERY STOUT EML. ECMWF SHOWS ABOUT 2500
J/KG OF SBCAPE AND 30 TO 40 KT OF SHEAR SO WILL HAVE TO WATCH OUT
FOR SEVERE IN LATER FORECASTS.
SATURDAY:
AMPLIFICATION OF THE WESTERN TROUGH IS EXPECTED SATURDAY. THE 12Z ECMWF
IS LESS AGGRESSIVE WITH CONVECTION FOR SATURDAY EVENING ACROSS THE WEST
THAN COMPARED TO THE 00Z RUN. THIS IS PROBABLY DUE TO THE CONTINUED
STRONG EML FORECAST BY THE MODEL. WILL NOT GO HIGHER THAN SLIGHT POPS
IN THE MEANTIME. NOT MUCH UPPER LEVEL SUPPORT AS THE MAIN 250 HPA JET
AXIS IS STILL PRETTY FAR WEST. WILL CONTINUE HOT TEMPERATURES IN THE
GRIDS WITH MID TO UPPER 90S DEG F EXPECTED ACROSS MUCH OF THE REGION.
SUNDAY AND BEYOND:
CONVECTIVE PROSPECTS ARE BETTER SUNDAY AS THE RIGHT ENTRANCE REGION
OF THE AFOREMENTIONED 250 HPA TRAVERSES ACROSS NW KANSAS. CAA ASSOCIATED
WITH THE TROUGH AND LOW TO MID LEVEL COLD POOLS WILL ALLOW FOR A WEAKENING
OF THE EML. THE BEST CHANCE FOR CONVECTION APPEARS TO BE ACROSS CENTRAL
AND SOUTH CENTRAL KANSAS ALONG AND EASTWARD MIXING DRYLINE. THE
THERMODYNAMIC AND KINEMATIC PROFILES ARE SUPPORTIVE OF SEVERE WEATHER.
UL FLOW FLATTENS MONDAY AND TUESDAY AS THE ASSOCIATED TROUGH MOVES ACROSS
THE CANADIAN PRAIRIES. THIS WILL ALLOW FOR MORE SEASONAL YET ABOVE NORMAL
TEMPERATURES ACROSS SW KANSAS. WILL HAVE TO WATCH THE MIDWEEK PERIOD
NEXT WEEK AS IT TRANSITIONS INTO MORE OF A MCS PATTERN. DEWPOINTS/MOISTURE
COULD BE AN ISSUE THOUGH. HAVE GONE WITH A CLEANED UP VERSION OF ALLBLEND
POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1204 PM CDT WED MAY 23 2012
GUSTY SOUTH WINDS AT 20 TO 25 KNOTS WILL CONTINUE EARLY THIS
AFTERNOON AT HYS AND DDC AS A COLD FRONT SLOWLY MOVES SOUTH INTO
NORTH CENTRAL AND WEST CENTRAL KANSAS. NAM, HRRR, AND RAP APPEAR
TO HAVE A DECENT HANDLE ON THIS FRONTAL POSITION BASED ON 15Z
ANALYSIS SO WILL SO WILL FOLLOW THESE MODELS FOR WINDS THROUGH THE
REMAINDER OF THE AFTERNOON AND EARLY TONIGHT. VFR CONDITIONS ARE
EXPECTED THROUGH 06Z BUT SOME SCATTERED MVFR CLOUDS WILL BE
POSSIBLE BEHIND A COLD FRONT AS IT CROSSES SOUTHWEST KANSAS
BETWEEN 06Z AND 09Z. IN ADDITION TO THESE LOW CLOUDS THE WINDS
WILL BE ON THE INCREASE BEHIND THIS FRONT. BASED ON THE TIGHT
PRESSURE GRADIENT AND 30 TO 40 KNOTS OF BOUNDARY LAYER WINDS THERE
WILL BE A PERIOD OF WINDS IN THE 20 TO 25 KNOT RANGE IMMEDIATELY
BEHIND THIS FRONT EARLY THURSDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 55 83 62 97 / 10 0 10 10
GCK 53 82 60 96 / 10 0 10 10
EHA 56 85 59 96 / 0 0 10 10
LBL 54 85 62 100 / 0 0 10 10
HYS 55 80 59 86 / 30 10 10 20
P28 65 85 67 97 / 0 0 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR KSZ066-080-081-089-
090.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
151 PM CDT WED MAY 23 2012
...UPDATED SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1204 PM CDT WED MAY 23 2012
AT 12Z WEDNESDAY A 700MB ELEVATED MIXED LAYER EXTENDED FROM THE
PANHANDLE OF OKLAHOMA INTO EXTREME SOUTHWEST NEBRASKA. SOME 700MB
MOISTURE WAS LOCATED JUST NORTHWEST OF THIS ELEVATED MIXED LAYER
FROM NORTHWEST COLORADO INTO THE PANHANDLE OF NEBRASKA. A SURFACE
AND 850MB LOW WAS LOCATED UNDER THIS WARM LAYER IN NORTHWEST
KANSAS WITH A DRYLINE EXTENDING SOUTH INTO THE PANHANDLE OF TEXAS.
A SURFACE COLD FRONT STRETCHED FROM EASTERN NEBRASKA INTO EASTERN
COLORADO. ACROSS THE NORTHWEST UNITED STATES A 500MB THROUGH WAS
LOCATED ACROSS MONTANA AND IDAHO WITH AN UPPER LEVEL JET EXTENDING
FROM NORTHERN CALIFORNIA INTO NORTHWEST COLORADO. 100-120METER
HEIGHT FALLS WERE PRESENT ACROSS NORTHWEST COLORADO AND WYOMING
AND THIS WAS LOCATED NEAR THE LEFT EXIT REGION OF THE UPPER LEVEL
JET.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 142 PM CDT WED MAY 23 2012
NAM, RAP, AND HRRR WERE IN DECENT AGREEMENT WITH COLD FRONT
EXTENDING FROM NORTH CENTRAL KANSAS INTO EXTREME SOUTHWEST KANSAS
LATE THIS AFTERNOON AND EARLY THIS EVENING. THIS FRONT WILL BE
LOCATED UNDER +14C TO +16C 700MB TEMPERATURES. IN ADDITION THE
BETTER LOW LEVEL MOISTURE IS STILL FORECAST TO BE LOCATED ACROSS
CENTRAL KANSAS AND FROM NORTHWEST KANSAS INTO SOUTH CENTRAL
NEBRASKA. BASED ON MODEL SOUNDINGS THE WARM MID LEVEL TEMPERATURES
LATE TODAY/EARLY TONIGHT APPEARS TO SERVE AS A CAP ACROSS MOST OF
SOUTHWEST KANSAS. THE POSSIBLE EXCEPTION WILL BE NEAR AND NORTH OF
INTERSTATE 70 IN NORTH CENTRAL KANSAS WERE BETTER LOW LEVEL
FRONTOGENESIS AND MOISTURE WILL BE PRESENT. IN ADDITION THIS WILL
BE NEAR THE NORTHERN EDGE OF THE WARM MID LEVEL TEMPERATURES. THE
NAM EVEN SUGGESTS SOME COOLING OCCURRING IN THE MID LEVEL AFTER
21Z ALONG AND NORTH OF INTERSTATE 70. GIVEN THE COOLER MID LEVEL
TEMPERATURES, BETTER LOW LEVEL MOISTURE/FRONTOGENESIS NEAR THE
SURFACE BOUNDARY, AND CAPES EARLY TONIGHT GREATER THAN 1000 J/KG
WILL GO AHEAD AND KEEP A MENTION OF THUNDERSTORMS NEAR THE SURFACE
BOUNDARY. ALSO BASED ON 0-6KM SHEAR FORECAST TO BE AROUND 50
KNOTS ALONG WITH 1000-2000 J/KG THERE WILL BE A CHANCE FOR ANY
STORM THAT DOES DEVELOP TO BECOME SEVERE. MAIN HAZARD STILL
APPEARS TO BE HAIL UP TO HALF DOLLAR SIZE AND WINDS UP TO 60 MPH.
FURTHER WEST...THE CONVECTION DEVELOPING ACROSS NORTHEAST COLORADO IS
EXPECTED TO SPREAD EAST EARLY TONIGHT BUT STAY NORTH OF THE
INTERSTATE 70 DURING THE OVERNIGHT HOURS. THE COLD POOL THAT IS
FORECAST TO DEVELOP WITH THESE STORMS OVERNIGHT SHOULD PUSH THE
COLD FRONT SOUTH ACROSS ALL OF SOUTHWEST KANSAS AFTER MIDNIGHT. BY
EARLY THURSDAY MORNING THIS COLD FRONT IS EXPECTED TO BE LOCATED
ACROSS CENTRAL KANSAS AND NORTHERN OKLAHOMA. BOUNDARY LAYER WINDS
BEHIND THIS FRONT ARE FORECAST TO RANGE FROM 30 TO 35 KNOTS AND
GIVEN THE TIGHT PRESSURE GRADIENT BEHIND THIS FRONT THE SURFACE WINDS
MAY APPROACH ADVISORY CRITERIA FOR A FEW HOURS FOLLOWING THE
FRONTAL PASSAGE LATE TONIGHT. AT THIS TIME HAVE DECIDED TO KEEP
SUSTAINED WINDS JUST BELOW ADVISORY CRITERIA FOR A FEW HOURS
BEHIND THIS FRONT. IN ADDITION TO THE WINDS SOME LOW LEVEL
MOISTURE WILL RETURN TO NORTH CENTRAL AND SOUTHWEST KANSAS. THE
WRF AND NMM EVEN SUGGESTS SOME LIGHT PRECIPITATION WILL BE
POSSIBLE AS THE LOWER LEVELS SATURATES. AT THIS TIME GIVEN THE ISENTROPIC
DOWNGLIDE PRESENT AND DEPTH OF THE MOIST LAYER LESS THAN 3000 FEET
AM TRENDING AWAY FROM INSERTING PRECIPITATION CHANCES AFTER
MIDNIGHT.
ON THURSDAY THE GUSTY NORTHWEST WINDS WILL GRADUALLY SUBSIDE BY
MID MORNING AS THE COLD FRONT CONTINUES TO MOVE SOUTHEAST ACROSS
EASTERN KANSAS AND OKLAHOMA. IN SOUTHEAST COLORADO THIS FRONT IS
EXPECTED TO BECOME NEARLY STATIONARY DURING THE DAY WITH SOME
ISENTROPIC LIFT/WARM AIR ADVECTION DEVELOPING NORTH OF THIS
BOUNDARY BY LATE DAY. THIS MAY BRING AN INCREASE IN MID LEVEL CLOUD
COVER LATE DAY TO PORTIONS OF SOUTHWEST KANSAS BASED ON I310 AND
I315 ISENTROPIC SURFACES AND 12Z BUFR SOUNDINGS. GIVEN SOME
INCREASING CLOUDS LATE DAY AND 850MB TEMPERATURES AT 00Z FRIDAY
WILL TREND TOWARDS THE COOLER GUIDANCE IN FAR SOUTHWEST KANSAS
NEAR THE OKLAHOMA BORDER WHILE FURTHER NORTH HAVE KEPT HIGHS
CLOSER TO THE WARMER 850MB MIX DOWN TEMPERATURES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 356 AM CDT WED MAY 23 2012
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL TROUGH OF LOW PRESSURE
LIFTING NORTHEAST ACROSS NEBRASKA THURSDAY AND INTO THE WESTERN
GREAT LAKES REGION THURSDAY NIGHT BRINGING WIDESPREAD PRECIP CHANCES
TO THE DAKOTAS SOUTHWARD INTO NEBRASKA, AND POTENTIALLY NORTHERN
KANSAS EARLY THURSDAY. AN ATTENDANT COLD FRONT IS PROJECTED TO PUSH
SOUTH INTO WESTERN KANSAS SOMETIME EARLY THURSDAY BEFORE STALLING
OUT SOMEWHERE GENERALLY ACROSS EXTREME SOUTHERN SOUTHWEST KANSAS OR
NORTHERN OKLAHOMA AS A SURFACE LOW DEVELOPS ACROSS NORTHEASTERN NEW
MEXICO INTO THE PANHANDLES OF OKLAHOMA AND TEXAS. HOWEVER, THE
SURFACE LOW IS PROGGED TO QUICKLY LIFT NORTHEAST ALONG THE ADVANCING
FRONTAL BOUNDARY. MEANWHILE, THE GFS AND ECMWF CONTINUE TO SHOW THE
BEST DYNAMIC SUPPORT ALOFT REMAINING JUST OFF TO OUR NORTH WITH THE
EXIT REGION OF A STRONG +100KT UPPER LEVEL JET CORE LIFTING
NORTHEAST OUT OF NORTHERN COLORADO INTO NEBRASKA. ADDITIONALLY, GFS
AND ECMWF MODEL SOUNDINGS SHOW A LACK OF INSTABILITY ACROSS MUCH OF
SOUTHWEST KANSAS WITH CAPPING A POSSIBLE ISSUE AS WELL. SHOWERS AND
THUNDERSTORMS ARE LIKELY TO DEVELOP EARLY THURSDAY ALONG THE
ADVANCING FRONTAL BOUNDARY FROM THE UPPER MIDWEST DOWN INTO
NEBRASKA, AND JUST POSSIBLY INTO NORTHERN SECTIONS OF KANSAS, BUT
CONDITIONS SHOULD REMAIN FAIRLY DRY ACROSS SOUTHWEST KANSAS WITH
ONLY AN OUTSIDE SHOT FOR PRECIP ACROSS CENTRAL KANSAS.
AS THE FIRST UPPER LEVEL SHORTWAVE LIFTS FURTHER TO THE NORTHEAST
FRIDAY, A SECONDARY AND MORE AMPLIFIED UPPER LEVEL TROUGH IS
EXPECTED DROP SOUTH OUT OF THE PACIFIC NORTHWEST INTO MUCH OF
CALIFORNIA. THIS WILL SET UP A SOUTHWESTERLY FLOW ALOFT ACROSS THE
WESTERN HIGH PLAINS THAT WILL PERSIST WELL INTO THE WEEKEND. AS THE
UPPER LEVEL TROUGH IN THE FAR WEST CONUS DEEPENS IT WILL ENHANCE THE
UPPER LEVEL SOUTHWEST FLOW ACROSS THE WESTERN HIGH PLAINS. IN TURN,
THE STALLED FRONTAL BOUNDARY GENERALLY IN THE VICINITY OF THE KANSAS
AND OKLAHOMA BORDER, WILL BEGIN TO LIFT BACK NORTH ACROSS SOUTH
CENTRAL AND SOUTHWEST KANSAS AS A WARM FRONT FRIDAY AFTERNOON AND
EVENING. ALTHOUGH THE FLOW ALOFT WILL REMAIN FAIRLY WEAK, INCREASED
LIFT ALONG THE FRONTAL BOUNDARY COULD BE ENOUGH TO SET UP A FEW
DEVELOPING SHOWERS AND THUNDERSTORMS ACROSS CENTRAL KANSAS DURING
THIS TIME PERIOD. WILL RETAIN THE SLIGHT POPS ACROSS CENTRAL KANSAS.
ANOTHER ROUND OF PRECIP CHANCES ARE POSSIBLE ACROSS PORTIONS OF
WESTERN KANSAS BOTH DAYS OF THE WEEKEND AS THE UPPER LEVEL TROUGH
IN THE FAR WEST BEGINS TO LIFT NORTHEAST ACROSS THE INTERMOUNTAIN
WEST.
COOLER TEMPERATURES ARE EXPECTED THURSDAY IN WAKE OF A COLD FRONT
PROJECTED TO PUSH SOUTH ACROSS WESTERN KANSAS EARLY IN THE DAY. THE
NAM, GFS, AND ECWMF SHOW COOLER AIR FILTERING SOUTH INTO THE AREA
DURING THE DAY THURSDAY WITH H85 TEMPERATURES FALLING TO THE MID TO
UPPER TEENS(C) ACROSS WEST CENTRAL AND CENTRAL KANSAS WITH LOWER TO
MID 20S(C) ACROSS SOUTHWEST KANSAS. THE NAM, GFS, AND ECMWF INDICATE
DRY LAPSE RATES DEVELOPING BELOW H7 BY MID TO LATE AFTERNOON. SO,
LOOK FOR HIGHS UP INTO THE 80S(F) ACROSS SOUTH CENTRAL AND SOUTHWEST
KANSAS WITH UPPER 70S(F) A POSSIBILITY IN MORE NORTHERN PORTIONS OF
CENTRAL KANSAS. WARMER TEMPERATURES ARE LIKELY ACROSS SOUTH CENTRAL
AND SOUTHWEST KANSAS FRIDAY AS THE STALLED FRONTAL BOUNDARY LIFTS
BACK NORTH ACROSS WESTERN KANSAS. THERE IS A POSSIBLE ISSUE AS TO
HOW FAR BACK NORTH THE FRONT LIFTS BY LATE FRIDAY AFTERNOON THOUGH.
THE NAM AND ECMWF SHOW THE FRONT PUSHING BACK NORTH ALMOST TO THE
I-70 CORRIDOR WITH H85 TEMPERATURES NEAR 30C ACROSS MUCH OF
SOUTHWEST KANSAS TO THE UPPER 20S(C) IN SOUTH CENTRAL KANSAS. THE
GFS IS A LITTLE MORE CONSERVATIVE ON HOW FAR NORTH THE BOUNDARY
REACHES WITH A LESSER PRONOUNCED WARM UP. STILL, WIDESPREAD 90S(F)
ARE LIKELY ACROSS MUCH OF SOUTH CENTRAL AND SOUTHWEST KANSAS WITH
ONLY 80S(F) STILL POSSIBLE IN NORTHERN PORTIONS OF CENTRAL KANSAS.
TEMPERATURES ARE LIKELY TO REMAIN WELL ABOVE SEASONAL LEVELS
THROUGHOUT THE WEEKEND AS THE BUILDING UPPER LEVEL TROUGH IN THE
FAR WEST LIFTS NORTHEAST INTO THE ROCKIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1204 PM CDT WED MAY 23 2012
GUSTY SOUTH WINDS AT 20 TO 25 KNOTS WILL CONTINUE EARLY THIS
AFTERNOON AT HYS AND DDC AS A COLD FRONT SLOWLY MOVES SOUTH INTO
NORTH CENTRAL AND WEST CENTRAL KANSAS. NAM, HRRR, AND RAP APPEAR
TO HAVE A DECENT HANDLE ON THIS FRONTAL POSITION BASED ON 15Z
ANALYSIS SO WILL SO WILL FOLLOW THESE MODELS FOR WINDS THROUGH THE
REMAINDER OF THE AFTERNOON AND EARLY TONIGHT. VFR CONDITIONS ARE
EXPECTED THROUGH 06Z BUT SOME SCATTERED MVFR CLOUDS WILL BE
POSSIBLE BEHIND A COLD FRONT AS IT CROSSES SOUTHWEST KANSAS
BETWEEN 06Z AND 09Z. IN ADDITION TO THESE LOW CLOUDS THE WINDS
WILL BE ON THE INCREASE BEHIND THIS FRONT. BASED ON THE TIGHT
PRESSURE GRADIENT AND 30 TO 40 KNOTS OF BOUNDARY LAYER WINDS THERE
WILL BE A PERIOD OF WINDS IN THE 20 TO 25 KNOT RANGE IMMEDIATELY
BEHIND THIS FRONT EARLY THURSDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 57 82 63 93 / 10 0 10 10
GCK 55 81 60 91 / 10 0 10 10
EHA 53 87 59 95 / 0 0 10 10
LBL 56 85 63 95 / 0 0 10 10
HYS 57 80 61 87 / 30 10 10 20
P28 66 85 67 94 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR KSZ066-080-081-089-
090.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...JJOHNSON
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1245 PM MDT WED MAY 23 2012
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 1245 PM MDT WED MAY 23 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH
ACROSS THE NORTHERN ROCKIES...WITH WEST/SOUTHWEST FLOW ACROSS THE
INTER-MOUNTAIN WEST INTO THE CENTRAL HIGH PLAINS. AT THE SURFACE A COLD
FRONT HAS STALLED OVER WESTERN KANSAS...CURRENTLY ACROSS THE EASTERN
PART OF THE CWA.
A SHORTWAVE TROUGH CURRENTLY OVER THE GREAT BASIN WILL MOVE
EAST-NORTHEAST ACROSS NORTHCENTRAL COLORADO AND SOUTHWEST NEBRASKA
TONIGHT. SHOWERS/THUNDERSTORMS HAVE ALREADY DEVELOPED AHEAD OF THIS
FEATURE ALONG THE FRONT RANGE INTO SOUTHEASTERN WYOMING. THIS
ACTIVITY WILL SPREAD SOUTH AND EAST OVER OUR CWA LATER THIS
AFTERNOON...WITH COVERAGE INCREASING ACROSS THE NORTHERN PART OF OUR
FORECAST AREA THROUGH 06Z. CONVERGENCE ZONE ALONG AND NORTH OF
STALLED FRONT COULD ACT AS A FOCUS FOR EARLIER THUNDERSTORM
INITIATION LATER THIS AFTERNOON AND EVENING...HOWEVER THIS IS
REMOVED FROM LARGE SCALE ASCENT ASSOCIATED WITH SHORTWAVE SO
COVERAGE SHOULD BE LIMITED ACROSS THE SOUTH. VERY STRONG SHEAR IS
PRESENT ACROSS THE CWA...WITH INSTABILITY DECREASING THE FURTHER
NORTH IN THE CWA WHERE TD VALUES IN THE 30-40F RANGE HAVE ADVECTED
IN BEHIND THE FRONT. SEVERE CONVECTION SHOULD BE LIMITED TO THE I-70
CORRIDOR THROUGH EARLY EVENING WHERE THE BEST OVERLAP BETWEEN
SHEAR/INSTABILITY IS EXPECTED. LATER TONIGHT ELEVATED INSTABILITY
COULD COMBINE WITH STRONG UPPER LEVEL DYNAMICS ASSOCIATED WITH THE
SHORTWAVE ACROSS SOUTHWEST NEBRASKA TO BRING ADDITIONAL SEVERE
CHANCES. SUBSIDENCE QUICKLY BUILDS IN BEHIND DEPARTING SHORTWAVE
TROUGH AFTER 06Z...WITH COVERAGE DECREASING FROM THE SOUTHWEST TO
THE NORTHEAST THROUGH SUNRISE THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 230 AM MDT WED MAY 23 2012
THURSDAY NIGHT-FRIDAY NIGHT...SHOULD STILL HAVE A SMALL CHANCE FOR
PRECIPITATION THURSDAY NIGHT INTO FRIDAY MORNING AS THE THURSDAY
AFTERNOON DISTURBANCE LIFTS AWAY FROM THE AREA. NO CHANGES MADE TO
FRIDAY NIGHT POPS. HIGH TEMPERATURES ON FRIDAY IN THE 70S EXCEPT
LOW TO MID 80S FROM HILL CITY TO CHEYENNE WELLS AND POINTS SOUTH.
SATURDAY THROUGH TUESDAY...A LONGWAVE TROUGH WILL SEND SEVERAL
SHORTWAVE TROUGHS THROUGH ITS SOUTHWESTERLY UPPER LEVEL FLOW FOR THE
FIRST HALF OF THE PERIOD...AND THE PATTERN ALOFT WILL BECOME
INCREASINGLY ZONAL FOR THE SECOND HALF. THE PATTERN CONTINUES TO BE
ACTIVE...WITH THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS THROUGH
MUCH OF THE PERIOD.
MAIN CONCERN DURING THE PERIOD IS THE CHANCE FOR POTENTIALLY SEVERE
THUNDERSTORMS LATE ON SATURDAY. LATEST GUIDANCE APPEARS TO BE
SLOWING DOWN THE TROUGH WHICH WILL PROVIDE SUPPORT FOR STORMS...AND
THIS TREND WOULD SUGGEST MENTIONING STORMS IN THE EVENING BUT NOT
THE AFTERNOON. A CAP BETWEEN 50 AND 70 J/KG IN THE AFTERNOON MAY
ALSO DELAY STORM FORMATION UNTIL THE TROUGH NEARS THE AREA IN THE
EVENING...SO HAVE KEPT POPS SILENT DURING THE AFTERNOON AND INCLUDED
SLIGHT CHANCES OVERNIGHT. CURRENT THINKING IS THAT THE GREATEST
LIKELIHOOD FOR SEVERE STORMS WOULD BE OVER THE EASTERN PORTION OF THE
AREA CONSIDERING THE HIGHER INSTABILITY AND STOUT BUT BREAKABLE CAP
OUT EAST.
A COLD FRONT WILL MOVE EASTWARD INTO THE AREA ON SUNDAY
MORNING...BECOMING STATIONARY OVER THE AREA BY SUNDAY AFTERNOON. THE
FRONT WILL REMAIN MOSTLY STATIONARY UNTIL MONDAY AFTERNOON WHEN IT
MOVES FURTHER EASTWARD AND AWAY FROM THE REGION. HAVE KEPT POPS
SILENT ON MONDAY AND MONDAY NIGHT BEHIND THE FRONT. A WARM FRONT
WILL LIFT NORTHEASTWARD INTO THE AREA DURING THE DAYTIME ON TUESDAY
AND BRING THE CHANCE FOR PRECIP BACK TO THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1107 AM MDT WED MAY 23 2012
VFR CONDITIONS SHOULD PREVAIL AT BOTH KGLD AND KMCK THROUGH THE
TAF PERIOD. A COLD FRONT HAS DROPPED SOUTH OF BOTH TERMINALS.
WINDS HAVE INCREASED BEHIND THIS FRONT OUT OF THE N-NE TO 15-20KT
GUSTING 25-30KT. A DISTURBANCE WILL MOVE FROM NORTHEASTERN
COLORADO ACROSS SOUTHWEST NEBRASKA OVERNIGHT TONIGHT. SHOWERS AND
THUNDERSTORMS WILL DEVELOP TOWARDS BOTH TERMINALS...WITH THE BEST
CHANCES OVER KMCK 04Z-11Z. CHANCES ARE LOWER AT KGLD...THOUGH
THERE IS ENOUGH OF A CHANCE THAT THUNDERSTORMS COULD TRACK JUST
NORTH OF THE TERMINAL TO CARRY A VCTS GROUP LATE THIS AFTERNOON
THOUGH 08Z. SUB VFR CONDITIONS WILL BE POSSIBLE IF A STRONGER
STORM WERE TO PASS OVER EITHER TERMINAL. DRY CONDITIONS AND
W-NW WINDS AROUND 12KT SHOULD PREVAIL BY SUNRISE AT BOTH TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...007/CJS
AVIATION...DR
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1209 PM CDT WED MAY 23 2012
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1204 PM CDT WED MAY 23 2012
AT 12Z WEDNESDAY A 700MB ELEVATED MIXED LAYER EXTENDED FROM THE
PANHANDLE OF OKLAHOMA INTO EXTREME SOUTHWEST NEBRASKA. SOME 700MB
MOISTURE WAS LOCATED JUST NORTHWEST OF THIS ELEVATED MIXED LAYER
FROM NORTHWEST COLORADO INTO THE PANHANDLE OF NEBRASKA. A SURFACE
AND 850MB LOW WAS LOCATED UNDER THIS WARM LAYER IN NORTHWEST
KANSAS WITH A DRYLINE EXTENDING SOUTH INTO THE PANHANDLE OF TEXAS.
A SURFACE COLD FRONT STRETCHED FROM EASTERN NEBRASKA INTO EASTERN
COLORADO. ACROSS THE NORTHWEST UNITED STATES A 500MB THROUGH WAS
LOCATED ACROSS MONTANA AND IDAHO WITH AN UPPER LEVEL JET EXTENDING
FROM NORTHERN CALIFORNIA INTO NORTHWEST COLORADO. 100-120METER
HEIGHT FALLS WERE PRESENT ACROSS NORTHWEST COLORADO AND WYOMING
AND THIS WAS LOCATED NEAR THE LEFT EXIT REGION OF THE UPPER LEVEL
JET.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 345 AM CDT WED MAY 23 2012
THE MOST SIGNIFICANT FORECAST CHALLENGES FOR THE SHORT TERM PERIOD
INCLUDE 1) ANTICIPATING HOW HIGH TEMPERATURES WILL RISE IN ADVANCE
OF THE COLD FRONT THAT WILL ENTER SOUTHWEST KANSAS LATE THIS MORNING,
ESPECIALLY BEHIND THE DRYLINE THAT WILL MIX EASTWARD TO JUST WEST
OF DODGE CITY THIS AFTERNOON; 2) EVALUATING THE OCCURRENCE AND
COVERAGE OF THUNDERSTORMS THAT SHOULD FORM AS THE MID LEVEL WARM
PLUME WEAKENS ALONG THE FRONT IN NORTHERN KANSAS THIS AFTERNOON;
3) EVALUATING THE STRENGTH OF LOW LEVEL WINDS AS THE LOW LEVEL JET
MIXES OUT THIS MORNING; AND 4) ANTICIPATING LOW TEMPERATURES
BEHIND THE FRONT TONIGHT.
THE SURFACE LOW PRESSURE SYSTEM IN NORTHEASTERN COLORADO WILL DROP
SOUTHWARD SLOWLY IN THE LEE OF THE ROCKIES AND LIKELY WILL BE
CENTERED NEAR ELKHART BY THIS EVENING. A TIGHT PRESSURE GRADIENT
WILL PREVAIL ACROSS SOUTH CENTRAL INTO CENTRAL KANSAS TODAY BUT WILL
RELAX DURING THE AFTERNOON HOURS AS THE COLD FRONT BECOMES NEARLY
STATIONARY FROM NORTH CENTRAL KANSAS INTO SOUTHEASTERN COLORADO.
WINDS LIKELY WILL REACH ADVISORY CRITERIA FOR AT LEAST A FEW HOURS
IN SOUTH CENTRAL KANSAS FROM MID MORNING INTO THE AFTERNOON HOURS. A
DRYLINE WILL MIX EASTWARD IN THE DOWNSLOPE FLOW SOUTH OF THE SURFACE
CYCLONE, AND TEMPERATURES THIS AFTERNOON WILL BE ANOMALOUSLY HOT,
ESPECIALLY IN THE DRY AIR IN FAR SOUTHWEST KANSAS. HIGHS LIKELY WILL
EXCEED 100 DEGREES WEST OF THE DRYLINE WITH A PLUME OF UPPER 90
DEGREE TEMPERATURES JUST AHEAD OF THE COLD FRONT.
THE UPPER LEVEL TROUGH IN IDAHO WILL PROPAGATE RAPIDLY EASTWARD TO
WESTERN NEBRASKA BY MID AFTERNOON. SYNOPTIC SCALE UPWARD VERTICAL
MOTION WITH THE UPPER LEVEL TROUGH WILL SERVE TO WEAKEN MID LEVEL
INVERSION IN NORTHERN KANSAS, AND SCATTERED THUNDERSTORMS ARE LIKELY
TO DEVELOP ALONG THE FRONT FROM SOUTHERN NEBRASKA INTO NORTHERN
KANSAS. THERE IS SOME UNCERTAINTY ABOUT HOW FAR SOUTH INTO THE WARM
MID LEVEL AIR THE CONVECTION WILL UNZIP THIS EVENING. THE NMM IS
CONSIDERABLY MORE AGGRESSIVE WITH THUNDERSTORM DEVELOPMENT THAN THE
ADVANCED RESEARCH WRF OR THE RAP. MODEL SOUNDINGS FROM THE NAM
SUGGEST THAT CONVECTION WILL BE CAPPED UNTIL LATE AFTERNOON, BUT THE
INVERSION ERODES BETWEEN 00Z AND 03Z. BULK SHEAR IN THE 0 TO 6KM
LAYER IS IN EXCESS OF 50 KNOTS, AND SUFFICIENT INSTABILITY WILL BE
PRESENT TO SUPPORT HAIL AND WIND POTENTIAL. THE TEMPERATURE PROFILE
IS NOT SUPPORTIVE OF HUGE HAIL, BUT SOMETHING IN THE QUARTER TO HALF
DOLLAR SIZE SEEMS REASONABLE. SEVERE WORDING WAS INCLUDED ALONG THE
FRONT INTO THE EARLY EVENING HOURS.
THE JET STREAK IN THE EASTERN PACIFIC WILL SURGE INTO THE CENTRAL
ROCKIES BY 12Z THURSDAY, AND THE SURFACE CYCLONE WILL MOVE INTO
EASTERN KANSAS. THE AGEOSTROPHIC CIRCULATION IN THE EXIT REGION OF
THE JET WILL SUPPORT CONTINUED UPWARD VERTICAL MOTION BEHIND THE
FRONT FROM NORTHEAST COLORADO INTO NEBRASKA, AND THUNDERSTORMS ARE
LIKELY TO CONTINUE MUCH OF THE NIGHT. OUTFLOW FROM THE PRECIPITATION
AREA WILL ENHANCE BAROCLINICITY WITH THE COLD FRONT, AND
TEMPERATURES PROBABLY WILL DROP INTO THE 50S BY THURSDAY MORNING
ACROSS MUCH OF SOUTHWEST KANSAS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 356 AM CDT WED MAY 23 2012
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL TROUGH OF LOW PRESSURE
LIFTING NORTHEAST ACROSS NEBRASKA THURSDAY AND INTO THE WESTERN
GREAT LAKES REGION THURSDAY NIGHT BRINGING WIDESPREAD PRECIP CHANCES
TO THE DAKOTAS SOUTHWARD INTO NEBRASKA, AND POTENTIALLY NORTHERN
KANSAS EARLY THURSDAY. AN ATTENDANT COLD FRONT IS PROJECTED TO PUSH
SOUTH INTO WESTERN KANSAS SOMETIME EARLY THURSDAY BEFORE STALLING
OUT SOMEWHERE GENERALLY ACROSS EXTREME SOUTHERN SOUTHWEST KANSAS OR
NORTHERN OKLAHOMA AS A SURFACE LOW DEVELOPS ACROSS NORTHEASTERN NEW
MEXICO INTO THE PANHANDLES OF OKLAHOMA AND TEXAS. HOWEVER, THE
SURFACE LOW IS PROGGED TO QUICKLY LIFT NORTHEAST ALONG THE ADVANCING
FRONTAL BOUNDARY. MEANWHILE, THE GFS AND ECMWF CONTINUE TO SHOW THE
BEST DYNAMIC SUPPORT ALOFT REMAINING JUST OFF TO OUR NORTH WITH THE
EXIT REGION OF A STRONG +100KT UPPER LEVEL JET CORE LIFTING
NORTHEAST OUT OF NORTHERN COLORADO INTO NEBRASKA. ADDITIONALLY, GFS
AND ECMWF MODEL SOUNDINGS SHOW A LACK OF INSTABILITY ACROSS MUCH OF
SOUTHWEST KANSAS WITH CAPPING A POSSIBLE ISSUE AS WELL. SHOWERS AND
THUNDERSTORMS ARE LIKELY TO DEVELOP EARLY THURSDAY ALONG THE
ADVANCING FRONTAL BOUNDARY FROM THE UPPER MIDWEST DOWN INTO
NEBRASKA, AND JUST POSSIBLY INTO NORTHERN SECTIONS OF KANSAS, BUT
CONDITIONS SHOULD REMAIN FAIRLY DRY ACROSS SOUTHWEST KANSAS WITH
ONLY AN OUTSIDE SHOT FOR PRECIP ACROSS CENTRAL KANSAS.
AS THE FIRST UPPER LEVEL SHORTWAVE LIFTS FURTHER TO THE NORTHEAST
FRIDAY, A SECONDARY AND MORE AMPLIFIED UPPER LEVEL TROUGH IS
EXPECTED DROP SOUTH OUT OF THE PACIFIC NORTHWEST INTO MUCH OF
CALIFORNIA. THIS WILL SET UP A SOUTHWESTERLY FLOW ALOFT ACROSS THE
WESTERN HIGH PLAINS THAT WILL PERSIST WELL INTO THE WEEKEND. AS THE
UPPER LEVEL TROUGH IN THE FAR WEST CONUS DEEPENS IT WILL ENHANCE THE
UPPER LEVEL SOUTHWEST FLOW ACROSS THE WESTERN HIGH PLAINS. IN TURN,
THE STALLED FRONTAL BOUNDARY GENERALLY IN THE VICINITY OF THE KANSAS
AND OKLAHOMA BORDER, WILL BEGIN TO LIFT BACK NORTH ACROSS SOUTH
CENTRAL AND SOUTHWEST KANSAS AS A WARM FRONT FRIDAY AFTERNOON AND
EVENING. ALTHOUGH THE FLOW ALOFT WILL REMAIN FAIRLY WEAK, INCREASED
LIFT ALONG THE FRONTAL BOUNDARY COULD BE ENOUGH TO SET UP A FEW
DEVELOPING SHOWERS AND THUNDERSTORMS ACROSS CENTRAL KANSAS DURING
THIS TIME PERIOD. WILL RETAIN THE SLIGHT POPS ACROSS CENTRAL KANSAS.
ANOTHER ROUND OF PRECIP CHANCES ARE POSSIBLE ACROSS PORTIONS OF
WESTERN KANSAS BOTH DAYS OF THE WEEKEND AS THE UPPER LEVEL TROUGH
IN THE FAR WEST BEGINS TO LIFT NORTHEAST ACROSS THE INTERMOUNTAIN
WEST.
COOLER TEMPERATURES ARE EXPECTED THURSDAY IN WAKE OF A COLD FRONT
PROJECTED TO PUSH SOUTH ACROSS WESTERN KANSAS EARLY IN THE DAY. THE
NAM, GFS, AND ECWMF SHOW COOLER AIR FILTERING SOUTH INTO THE AREA
DURING THE DAY THURSDAY WITH H85 TEMPERATURES FALLING TO THE MID TO
UPPER TEENS(C) ACROSS WEST CENTRAL AND CENTRAL KANSAS WITH LOWER TO
MID 20S(C) ACROSS SOUTHWEST KANSAS. THE NAM, GFS, AND ECMWF INDICATE
DRY LAPSE RATES DEVELOPING BELOW H7 BY MID TO LATE AFTERNOON. SO,
LOOK FOR HIGHS UP INTO THE 80S(F) ACROSS SOUTH CENTRAL AND SOUTHWEST
KANSAS WITH UPPER 70S(F) A POSSIBILITY IN MORE NORTHERN PORTIONS OF
CENTRAL KANSAS. WARMER TEMPERATURES ARE LIKELY ACROSS SOUTH CENTRAL
AND SOUTHWEST KANSAS FRIDAY AS THE STALLED FRONTAL BOUNDARY LIFTS
BACK NORTH ACROSS WESTERN KANSAS. THERE IS A POSSIBLE ISSUE AS TO
HOW FAR BACK NORTH THE FRONT LIFTS BY LATE FRIDAY AFTERNOON THOUGH.
THE NAM AND ECMWF SHOW THE FRONT PUSHING BACK NORTH ALMOST TO THE
I-70 CORRIDOR WITH H85 TEMPERATURES NEAR 30C ACROSS MUCH OF
SOUTHWEST KANSAS TO THE UPPER 20S(C) IN SOUTH CENTRAL KANSAS. THE
GFS IS A LITTLE MORE CONSERVATIVE ON HOW FAR NORTH THE BOUNDARY
REACHES WITH A LESSER PRONOUNCED WARM UP. STILL, WIDESPREAD 90S(F)
ARE LIKELY ACROSS MUCH OF SOUTH CENTRAL AND SOUTHWEST KANSAS WITH
ONLY 80S(F) STILL POSSIBLE IN NORTHERN PORTIONS OF CENTRAL KANSAS.
TEMPERATURES ARE LIKELY TO REMAIN WELL ABOVE SEASONAL LEVELS
THROUGHOUT THE WEEKEND AS THE BUILDING UPPER LEVEL TROUGH IN THE
FAR WEST LIFTS NORTHEAST INTO THE ROCKIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1204 PM CDT WED MAY 23 2012
GUSTY SOUTH WINDS AT 20 TO 25 KNOTS WILL CONTINUE EARLY THIS
AFTERNOON AT HYS AND DDC AS A COLD FRONT SLOWLY MOVES SOUTH INTO
NORTH CENTRAL AND WEST CENTRAL KANSAS. NAM, HRRR, AND RAP APPEAR
TO HAVE A DECENT HANDLE ON THIS FRONTAL POSITION BASED ON 15Z
ANALYSIS SO WILL SO WILL FOLLOW THESE MODELS FOR WINDS THROUGH THE
REMAINDER OF THE AFTERNOON AND EARLY TONIGHT. VFR CONDITIONS ARE
EXPECTED THROUGH 06Z BUT SOME SCATTERED MVFR CLOUDS WILL BE
POSSIBLE BEHIND A COLD FRONT AS IT CROSSES SOUTHWEST KANSAS
BETWEEN 06Z AND 09Z. IN ADDITION TO THESE LOW CLOUDS THE WINDS
WILL BE ON THE INCREASE BEHIND THIS FRONT. BASED ON THE TIGHT
PRESSURE GRADIENT AND 30 TO 40 KNOTS OF BOUNDARY LAYER WINDS THERE
WILL BE A PERIOD OF WINDS IN THE 20 TO 25 KNOT RANGE IMMEDIATELY
BEHIND THIS FRONT EARLY THURSDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 98 57 82 63 / 0 10 0 10
GCK 96 55 81 60 / 10 10 0 10
EHA 99 53 87 59 / 0 0 0 10
LBL 103 56 85 63 / 0 0 0 10
HYS 97 57 80 61 / 30 30 10 10
P28 95 66 85 67 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR KSZ066-080-081-089-
090.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...RUTHI
LONG TERM...JJOHNSON
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1256 AM CDT WED MAY 23 2012
...AVIATION SECTION UPDATED...
.SYNOPSIS...
ISSUED AT 1218 PM CDT TUE MAY 22 2012
A 500MB UPPER TROUGH WAS LOCATED NEAR THE SOUTHWEST COAST OF BRITISH
COLUMBIA AND NORTHWEST WASHINGTON AT 12Z TUESDAY. A 120-140KT
UPPER LEVEL JET WAS PLACE NEAR AND JUST SOUTHWEST OF THE BASE OF
THIS UPPER TROUGH. 90-110 METER HEIGHT FALLS WERE OBSERVED ACROSS
EASTERN IDAHO AND WESTERN MONTANA. A WESTERLY FLOW EXTENDED
ACROSS THE ROCKIES INTO THE WESTERN HIGH PLAINS WITH +12 TO +13C
700MB TEMPERATURES STRETCHING FROM EASTERN WYOMING/WESTERN
NEBRASKA INTO NORTHEAST NEW MEXICO. UNDER THESE WARM 700MB
TEMPERATURES AT THE SURFACE THERE WAS A TROUGH OF LOW PRESSURE
ACROSS WESTERN NEBRASKA AND EXTREME EASTERN COLORADO/FAR WESTERN
KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 128 PM CDT TUE MAY 22 2012
RAP, NAM AND HRRR PLACE THE SURFACE TROUGH OF LOW PRESSURE NEAR
THE COLORADO BORDER THIS EVENING. MODEL SOUNDINGS AT 00Z
WEDNESDAYS IN THIS AREA INDICATING LITTLE TO NO CIN WITH A
TEMPERATURES DRY ADIABATIC UP TO AROUND THE 600MB LEVEL WHERE SOME
MOISTURE IS PRESENT. ALSO OBSERVING SOME INSTABILITY PRESENT AS
WELL SO AM UNABLE TO COMPLETELY RULE OUT A EARLY EVENING
THUNDERSTORM DEVELOPING NEAR THE COLORADO BORDER EARLY THIS
EVENING. RAP AND HRRR DO HINT AT A FEW STORMS DEVELOPING AFTER 22Z
NEAR THE ELKHART WHERE THE BETTER INSTABILITY ARE FORECAST TO BE
LOCATED. WITH THIS IN MIND THE PREVIOUS PRECIPITATION FORECAST FOR
EXTREME SOUTHWEST KANSAS STILL APPEARS TO BE ON TRACK. ALSO BASED
ON THE INVERTED V TYPE OF SOUNDINGS IT DOES APPEAR THAT STRONG
WINDS UP TO 60 OR 70 MPH WILL BE THE MAIN HAZARD. ANY STORM THAT
DOES DEVELOP EARLY THIS EVENING IS EXPECTED TO END BEFORE MIDNIGHT
BUT MAY MOVE AS FAR EAST AS LIBERAL IF THESE A COLD POOL CAN BE
DEVELOPED FROM STORMS. AFTER MIDNIGHT SOUTH WINDS OF 15 TO 25 MPH
ARE EXPECTED TO CONTINUE AND BASED ON TEMPERATURES EARLIER THIS
MORNING WILL FAVOR OVERNIGHT LOWS AROUND 5F WARMER THAN GUIDANCE.
ON WEDNESDAY A SURFACE TROUGH/DRYLINE WILL SLIDE EAST INTO
WESTERN KANSAS DURING THE DAY AS A COLD FRONT DROPS SOUTH INTO
NORTHWEST KANSAS BY LATE MORNING. THE COLD FRONT IS EXPECTED TO BE
LOCATED FROM WEST CENTRAL KANSAS AND NORTH CENTRAL KANSAS BY THE
MID AFTERNOON AS WARM MID LEVEL TEMPERATURES SPREADS EAST ACROSS
SOUTHWEST KANSAS. MODEL SOUNDINGS INDICATING ANOTHER DAY OF GOOD
MIXING AND BASED ON MODEL SOUNDINGS AT 00Z THURSDAY IT CURRENTLY
APPEARS HIGHS AROUND 100 DEGREES WILL STILL BE POSSIBLE WEST OF
THE DRYLINE. EAST OF THE DRYLINE AND NEAR THE COLD FRONT THE HIGHS
WILL BE SLIGHTLY COOLER AND RANGE FROM THE LOW TO MID 90S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 234 PM CDT TUE MAY 22 2012
WEDNESDAY NIGHT:
A FRONTAL BOUNDARY COULD BE THE IMPETUS FOR CONVECTION WEDNESDAY NIGHT
MAINLY ACROSS THE INTERSTATE 70 CORRIDOR. MARGINAL SURFACE DEWPOINTS
IN THE 50S DEG F AND VERY WARM MAXIMUM TEMPERATURES IN THE 90S DEG F
ACROSS CENTRAL KANSAS WILL CONTRIBUTE TO 1500 TO 2500 J/KG OF SBCAPE.
AN 850 HPA THETA-E AXIS WILL ALSO EXIST ACROSS WEST CENTRAL KANSAS WITH
BROAD SOUTHWESTERLY FLOW ALOFT WHICH POINT TO FAVORABLE CONDITIONS FOR
CONVECTION. SEVERE WEATHER CANNOT BE RULED OUT WITH 40 TO 50 KT OF BULK
0 TO 6 KM SHEAR.
THURSDAY:
A BROAD 500 HPA TROUGH IS EXPECTED FROM THE PACIFIC NORTHWEST TOWARDS
THE NORTHERN PLAINS. ANOTHER VORTMAX MOVING DOWNSTREAM WILL USHER
IN A COLD FRONT EXTENDING FROM THE UPPER MIDWEST TO SOMEWHERE IN
KANSAS. I SAY SOMEWHERE BECAUSE THERE IS PRETTY LARGE SPATIAL DIFFERENCES
BETWEEN THE ECMWF/GFS. THIS IS PARTICULARLY TRUE WHEN THE FRONT RETURNS
AS A WARM FRONT LATE THURSDAY. DECIDED TO TAKE THE MORE AGGRESSIVE
ECMWF APPROACH WITH THE NORTHWARD PROGRESSION OF THIS WARM FRONT. SOUTH
OF THIS FRONT, LOW LEVEL TEMPS ARE EXPECTED TO BE VERY WARM (30 DEG
C @ 850 HPA/15 DEG C @ 700 HPA), SO HAVE KEPT LOWER 90S DEG F TOWARDS
THE OKLAHOMA BORDER AND "COOLER" 80S DEG F ACROSS WEST CENTRAL KANSAS.
NOT EXPECTING ANY CONVECTION AS A RESULT OF THE EML ADVECTION ACROSS
SW KANSAS.
FRIDAY:
A WAA PATTERN WILL STRENGTHEN FRIDAY WITH THE EML SPREADING FURTHER
NORTH AND 850 HPA TEMPERATURES WARMING TO 33 DEC C. 700 HPA TEMPERATURES
WILL ALSO BE VERY WARM AND NEAR 16 DEG C. THERE MIGHT BE AN ISOLATED
STORM NEAR HAYS FRIDAY EVENING, BUT AM DUBIOUS OF THIS GFS SOLUTION
SO HAVE KEPT POPS IN SLIGHT CATEGORY GIVEN THE STOUT EML. THERE IS ALSO
NOT MUCH IN THE WAY OF UPPER LEVEL SUPPORT AS 500 HPA HEIGHT INCREASES
ARE EXPECTED ACROSS THE REGION ASSOCIATED WITH MID LEVEL SHORTWAVE RIDGING.
TEMPERATURES WILL BE HOT AND IN THE 90S DEG F. IF THE ECMWF SOLUTION
IS CORRECT, THEN A 100 DEGREE DAY IS POSSIBLE FOR SOME LOCATIONS AND
TEMPERATURES NEED TO BE INCREASED IN THE FUTURE.
SATURDAY AND BEYOND:
FOLLOWED THE ECMWF SOLUTION FOR THIS PERIOD. A VERY BROAD MID LEVEL
TROUGH IS EXPECTED ACROSS THE GREAT BASIN. ANY JET LEVEL DYNAMICS
LOOK TO REMAIN WELL NORTH OF KANSAS WITH GREATEST CHANCE OF HIGHER
IMPACT SEVERE WEATHER NORTH OF THE REGION. THERE COULD BE SOME STORMS
ACROSS SOUTHWEST KANSAS THROUGH THE WEEKEND, HOWEVER, THE ATMOSPHERE
LOOKS PRETTY CAPPED. MADE A FEW TWEAKS TO THE ALLBLEND POPS (CLEANED
UP) AND WARMED TEMPERATURES UP WITH A BIAS TOWARDS THE ECMWF.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1254 AM CDT WED MAY 23 2012
A COLD FRONT EXTENDED FROM EASTERN NORTH DAKOTA TO A LOW PRESSURE
SYSTEM IN NORTHEAST COLORADO AT 05Z. THIS FRONT WILL CONTINUE TO
MOVE SOUTHEAST AS AN UPPER LEVEL TROUGH PROPAGATES NORTH DAKOTA INTO
MANITOBA THIS MORNING. ANOTHER STRONG UPPER LEVEL TROUGH THAT WAS IN
WESTERN IDAHO AT 05Z WILL MOVE INTO WESTERN NEBRASKA BY 00Z
THURSDAY. THE LOW PRESSURE SYSTEM IN NORTHEAST COLORADO WILL DEVELOP
SOUTHWARD IN THE LEE OF THE ROCKIES TODAY AND WILL BE CENTERED NORTH
OF ELKHART BY LATE AFTERNOON. THE SURFACE COLD FRONT WILL EXTEND
FROM SOUTHEAST NEBRASKA TO THE LOW PRESSURE SYSTEM NORTH OF ELKHART
BY 00Z AND WILL SURGE SOUTHWARD AS THE SURFACE LOW PROPAGATES INTO
EASTERN KANSAS BY 12Z THURSDAY.
VFR CONDITIONS WILL PREVAIL FOR MOST OF THE DAY WITH ONLY SCATTERED
CIRRIFORM CLOUDS AOA 250. VERY WARM AIR IN THE MID LEVELS OF THE
ATMOSPHERE WILL PRECLUDE DEVELOPMENT OF THUNDERSTORMS MOST OF TODAY.
THE EDGE OF THE EXTREMELY WARM AIR ALOFT WILL BE OVER NORTHERN
KANSAS LATE THIS AFTERNOON, AND CONVERGENCE ALONG THE COLD FRONT
ALONG WITH A WEAKER CAPPING INVERSION WILL RESULT IN DEVELOPMENT OF
SCATTERED THUNDERSTORMS NEAR HYS AFTER 22Z. THE THUNDERSTORMS WILL
MOVE NORTHEAST INTO NORTH CENTRAL KANSAS AND SOUTHERN NEBRASKA BY
03Z. AN AREA OF LOW CLOUDS WITH CEILINGS 020-030 WILL DEVELOP
TONIGHT BEHIND THE COLD FRONT AS IT SURGES SOUTHWARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 63 86 64 94 / 10 10 10 10
GCK 58 85 61 92 / 10 10 10 10
EHA 58 91 60 96 / 10 10 10 10
LBL 61 89 64 96 / 10 10 10 10
HYS 61 83 62 90 / 20 10 10 20
P28 70 89 68 96 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...RUTHI
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
118 PM CDT WED MAY 23 2012
.DISCUSSION...
FOR THE 18Z TAF PACKAGE.
&&
.AVIATION...
VFR EXPECTED TO PREVAIL TODAY AMID FAIR WEATHER CU BASED A0A 3K
FT. SOUTH WINDS HAVE BEGUN TO INCREASE AS THE GRADIENT ACROSS THE
AREA TIGHTENS BETWEEN HIGH PRESSURE TO THE EAST AND LOW PRESSURE
OVER THE PLAINS. WINDS EXPECTED TO SETTLE DOWN THIS EVENING...WITH
MVFR VSBYS DEVELOPING OVER SOUTH CENTRAL LOUISIANA DURING THE
OVERNIGHT/EARLY MORNING HOURS. VFR TO PREVAIL ELSEWHERE.
13
&&
.PREV DISCUSSION... /ISSUED 1107 AM CDT WED MAY 23 2012/
UPDATE...HAVE GONE AHEAD AND ADDED ISOLATED THUNDERSTORMS INTO
THE FORECAST FOR THIS AFTERNOON FOR THE NORTHEAST AND EASTERN
PORTIONS OF THE FORECAST AREA. CAPES PROGGED TO ADVANCE INTO A
2500-3000 J/KG RANGE ACROSS THIS AREA AS WARM FRONT RETREATS
NORTHEAST. RUC13 SHOWING DECENT LOW LEVEL CONVERGENCE SETTING UP
WITH LITTLE OR NO CAPPING IN PLACE. COULD NOT RULE OUT PULSE
SEVERE SHOULD ACTIVITY DEVELOP.
MARCOTTE
PREV DISCUSSION... /ISSUED 440 AM CDT WED MAY 23 2012/
DISCUSSION...
12Z TAF ISSUANCE.
AVIATION...
ONLY ISSUE THIS MORNING WILL BE INTERMITTENT MVFR/IFR VSBY FOR
LCH/LFT/ARA THRU 13Z. THE TIGHTENING PRESSURE GRADIENT OVER SE
TX/SW LA WILL YIELD SSW WINDS 12-14 KTS WITH GUSTS OVER 20 KTS FOR
BPT/LCH LATER THIS MORNING INTO THE AFTERNOON. FURTHER EAST...WINDS
WILL BE JUST A TAD LESS...STILL EXPECTING TO RANGE 8-12 KTS.
OTHERWISE...VFR EXPECTED.
DML
PREV DISCUSSION... /ISSUED 357 AM CDT WED MAY 23 2012/
DISCUSSION...
SFC ANALYSIS SHOWS A FRONTAL BOUNDARY BISECTING THE FORECAST AREA
ALONG AN ESE-WNW LINE THIS MORNING. WATER VAPOR IMAGERY SHOWS
RIDGING SETTING UP OVER THE CNTL CONUS ALTHOUGH A WEAK SHORTWAVE
RIDING OVER THE RIDGE CROSSING SERN TX. LOCAL RADARS ARE PPINE
ALTHOUGH REGIONAL 88DS SHOW A FEW SHOWERS/STORMS SETTING UP ALONG
THE LAND BREEZE OVER THE NEAR SHORE WATERS OF SERN LA.
BASICALLY A PERSISTENT FORECAST IN PLACE THIS MORNING. INSERTED
PATCHY FOG WORDING FOR THIS MORNING ACROSS THE FORECAST AREA AS
VARIOUS SFC OBS HAVE SHOWN SLIGHT RESTRICTIONS TO VISIBILITIES
THROUGH THE NIGHT...AND THESE ARE LIKELY TO LOWER SOME AROUND OR
JUST AFTER SUNRISE. THEREAFTER A FEW SHOWERS OR STORMS ARE
POSSIBLE MAINLY THIS AFTERNOON AS OUR AIRMASS REMAINS SOMEWHAT
MOIST THOUGH NO LAYERS THROUGH THE COLUMN EVEN APPROACH
SATURATION. HOWEVER BETTER CAPPING IS EXPECTED TODAY AS THE RIDGE
ALOFT BUILDS OVER THE CNTL GULF COAST REGION WHICH SHOULD LIMIT
CONVECTION...AND POPS ARE LIMITED TO THE SILENT 10 NEIGHBORHOOD.
POPS FURTHER DIMINISH INTO THE WEEKEND AS THE RIDGE GAINS A BETTER
GRIP ALOFT...FURTHER STRENGTHENING THE CAP AND REALLY PUTTING A
LID ON CONVECTIVE DEVELOPMENT. RISING HEIGHTS ALOFT WILL ALSO LEAD
TO A LITTLE WARMING WITH MAX TEMPS ALREADY RUNNING ABOVE MOS
NUMBERS BY A DEGREE OR TWO...AND THIS TREND WILL CONTINUE.
POPS FINALLY RETURN TO THE FORECAST BY EARLY NEXT WEEK AS A STRONG
SHORTWAVE CROSSING THE NRN TIER OF THE CONUS BREAKS DOWN THE RIDGE
AND A WEAKNESS DEVELOPS OVER THE NWRN GULF. TEMPS WILL ALSO BEGIN
TO MODERATE JUST SLIGHTLY AT THIS TIME...EXPECTED TO REMAIN IN THE
LOWER 90S.
MARINE...
A TIGHTENING PRESSURE GRADIENT THANKS TO LOW PRESSURE DEEPENING
OVER THE PLAINS STATES WILL LEAD TO CAUTION CRITERIA SRLY WINDS
OVER THE WRN WATERS BY LATE AFTERNOON...SPREADING EWD THROUGH THE
EVENING. SCA WINDS ARE POSSIBLE OVER THE WRN WATERS BY LATE
TONIGHT BEFORE THE LOW DEPARTS AND HIGH PRESSURE BEGINS TO BUILD
BACK OVER THE NRN GULF. THEREAFTER MAINLY LIGHT SRLY TO SOMETIMES
ERLY FLOW EXPECTED TO LINGER WITH HIGH PRESSURE REMAINING IN
CONTROL.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 91 71 91 73 91 / 10 10 10 0 10
KBPT 91 72 91 74 91 / 10 10 10 0 10
KAEX 93 67 93 69 93 / 20 10 10 0 10
KLFT 91 70 91 72 91 / 20 10 10 0 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1107 AM CDT WED MAY 23 2012
.UPDATE...HAVE GONE AHEAD AND ADDED ISOLATED THUNDERSTORMS INTO
THE FORECAST FOR THIS AFTERNOON FOR THE NORTHEAST AND EASTERN
PORTIONS OF THE FORECAST AREA. CAPES PROGGED TO ADVANCE INTO A
2500-3000 J/KG RANGE ACROSS THIS AREA AS WARM FRONT RETREATS
NORTHEAST. RUC13 SHOWING DECENT LOW LEVEL CONVERGENCE SETTING UP
WITH LITTLE OR NO CAPPING IN PLACE. COULD NOT RULE OUT PULSE
SEVERE SHOULD ACTIVITY DEVELOP.
&&
MARCOTTE
&&
.PREV DISCUSSION... /ISSUED 440 AM CDT WED MAY 23 2012/
DISCUSSION...
12Z TAF ISSUANCE.
AVIATION...
ONLY ISSUE THIS MORNING WILL BE INTERMITTENT MVFR/IFR VSBY FOR
LCH/LFT/ARA THRU 13Z. THE TIGHTENING PRESSURE GRADIENT OVER SE
TX/SW LA WILL YIELD SSW WINDS 12-14 KTS WITH GUSTS OVER 20 KTS FOR
BPT/LCH LATER THIS MORNING INTO THE AFTERNOON. FURTHER EAST...WINDS
WILL BE JUST A TAD LESS...STILL EXPECTING TO RANGE 8-12 KTS.
OTHERWISE...VFR EXPECTED.
DML
PREV DISCUSSION... /ISSUED 357 AM CDT WED MAY 23 2012/
DISCUSSION...
SFC ANALYSIS SHOWS A FRONTAL BOUNDARY BISECTING THE FORECAST AREA
ALONG AN ESE-WNW LINE THIS MORNING. WATER VAPOR IMAGERY SHOWS
RIDGING SETTING UP OVER THE CNTL CONUS ALTHOUGH A WEAK SHORTWAVE
RIDING OVER THE RIDGE CROSSING SERN TX. LOCAL RADARS ARE PPINE
ALTHOUGH REGIONAL 88DS SHOW A FEW SHOWERS/STORMS SETTING UP ALONG
THE LAND BREEZE OVER THE NEAR SHORE WATERS OF SERN LA.
BASICALLY A PERSISTENT FORECAST IN PLACE THIS MORNING. INSERTED
PATCHY FOG WORDING FOR THIS MORNING ACROSS THE FORECAST AREA AS
VARIOUS SFC OBS HAVE SHOWN SLIGHT RESTRICTIONS TO VISIBILITIES
THROUGH THE NIGHT...AND THESE ARE LIKELY TO LOWER SOME AROUND OR
JUST AFTER SUNRISE. THEREAFTER A FEW SHOWERS OR STORMS ARE
POSSIBLE MAINLY THIS AFTERNOON AS OUR AIRMASS REMAINS SOMEWHAT
MOIST THOUGH NO LAYERS THROUGH THE COLUMN EVEN APPROACH
SATURATION. HOWEVER BETTER CAPPING IS EXPECTED TODAY AS THE RIDGE
ALOFT BUILDS OVER THE CNTL GULF COAST REGION WHICH SHOULD LIMIT
CONVECTION...AND POPS ARE LIMITED TO THE SILENT 10 NEIGHBORHOOD.
POPS FURTHER DIMINISH INTO THE WEEKEND AS THE RIDGE GAINS A BETTER
GRIP ALOFT...FURTHER STRENGTHENING THE CAP AND REALLY PUTTING A
LID ON CONVECTIVE DEVELOPMENT. RISING HEIGHTS ALOFT WILL ALSO LEAD
TO A LITTLE WARMING WITH MAX TEMPS ALREADY RUNNING ABOVE MOS
NUMBERS BY A DEGREE OR TWO...AND THIS TREND WILL CONTINUE.
POPS FINALLY RETURN TO THE FORECAST BY EARLY NEXT WEEK AS A STRONG
SHORTWAVE CROSSING THE NRN TIER OF THE CONUS BREAKS DOWN THE RIDGE
AND A WEAKNESS DEVELOPS OVER THE NWRN GULF. TEMPS WILL ALSO BEGIN
TO MODERATE JUST SLIGHTLY AT THIS TIME...EXPECTED TO REMAIN IN THE
LOWER 90S.
MARINE...
A TIGHTENING PRESSURE GRADIENT THANKS TO LOW PRESSURE DEEPENING
OVER THE PLAINS STATES WILL LEAD TO CAUTION CRITERIA SRLY WINDS
OVER THE WRN WATERS BY LATE AFTERNOON...SPREADING EWD THROUGH THE
EVENING. SCA WINDS ARE POSSIBLE OVER THE WRN WATERS BY LATE
TONIGHT BEFORE THE LOW DEPARTS AND HIGH PRESSURE BEGINS TO BUILD
BACK OVER THE NRN GULF. THEREAFTER MAINLY LIGHT SRLY TO SOMETIMES
ERLY FLOW EXPECTED TO LINGER WITH HIGH PRESSURE REMAINING IN
CONTROL.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 91 71 91 73 91 / 10 10 10 0 10
KBPT 91 72 91 74 91 / 10 10 10 0 10
KAEX 93 67 93 69 93 / 20 10 10 0 10
KLFT 91 70 91 72 91 / 20 10 10 0 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
119 AM EDT WED MAY 23 2012
.SYNOPSIS...
A WEAKENING COLD FRONT WILL CROSS THE STATE OVERNIGHT. AN UPPER LEVEL
RIDGE OF HIGH PRESSURE WILL BUILD BACK OVER THE STATE ON WEDNESDAY
AND REMAIN OVER THE REGION THROUGH FRIDAY.&&
.NEAR TERM /THROUGH TODAY/...
UPDATE 0115L: RAIN SHOWER ACTIVITY ACROSS THE N CONTS TO GRADUALLY
DECREASE IN COVERAGE AS FCST AND SHOULD DIMINISH/MOVE OUT OF THE
AREA NEXT FEW HRS. FCST PRETTY MUCH ON TRACK W/ NO MAJOR
ADJUSTMENTS NEEDED ATTM...
950 PM UPDATE: WHATS LEFT OF THE LLVL MOISTURE FLUX CNVRG ALG A
WEAKENING COLD FRONT IS ENDING...ALLOWING HEAVIER SHWRS TO FINALLY
REDUCE HRLY RNFL RATES INTO THE MDT AND LGT CTGRY. HRRR GUIDANCE
ALG WITH OTHER LARGER DOMAIN SYNOPTIC SCALE MODELS ALSO SHOW THIS
DIMINISHING TREND...BOTH IN INTENSITY AND CVRG...CONTG INTO THE
LATE NGT HRS...SO ADDITIONAL HVY RNFL APPEARS VERY LIKELY ATTM.
OUTSIDE OF EXTENDING SIG 00-06Z QPF AND CORRESPONDING POPS SE A
LITTLE FROM THE LAST UPDATE TO INCLUDE PRESQUE ISLE...WE LOADED
OBSVD 2000 LDT SFC TEMPS AND MERGED THEM TO FCST OVRNGT LOWS AT
0500 LDT WED MORN. NO OTHER CHGS NEEDED TO THE REMAINING FCST
ELEMENTS FOR THE NEAR TERM ATTM.
530 PM UPDATE: UPDATED POPS TO CORRESPOND TO THE AXIS OF HEAVIEST
SHWRS OVR FAR NRN PTNS OF THE FA ATTM. RADAR INDICATES THE
HEAVIEST RADAR ESTIMATED RNFL ATTM BETWEEN NINE MILE BRIDGE AND
CLAYTON LAKE OF NW AROOSTOOK COUNTY. OTHER NARROW BANDS OF 1 INCH
PLUS RNFL ARE NEAR STOCKHOLM AND NEW CANADA OF NE AND N CNTRL
AROOSTOOK COUNTY. MOVEMENT OF THIS LINE OF HVY RN SHWRS...WHICH
ATTM IS TO LOW TOP FOR LGTNG IS MOVING WITH THE SLOWER SPEED
ASSOCIATED WITH BACKWARD CORFIDI VECTOR MOTION WHICH ATTM IS FROM
THE S AT 5 TO 10 KT. THIS MOTION SHOULD INCREASE LATER THIS EVE TO
10 TO 15 KT. THIS FASTER MOTION WITH LESS INTENSE REFS SHOULD
DECREASE ANY CONCERNS OF MINOR LOCALIZED FLOODING BY THIS TM.
OTHERWISE...WE LOADED OBSVD 1700 LDT SFC TEMPS AND MERGED THEM TO
FCST OVRNGT LOWS AT 0500 LDT WED MORN.
ORGNL DISC: WEAK LOW PRESSURE SOUTH OF THE GULF OF MAINE AND THE
COLD FRONT SLOWLY MOVING OUT OF QUEBEC INTO NW MAINE WILL COMBINE
TO PRODUCE CLOUDY CONDITIONS AND SHOWERS. MOST OF THE SHOWER
ACTIVITY WILL BE FOCUSED ALONG THE FRONT IN ZONES 1 THROUGH 4 LATE
THIS AFTERNOON AND EVENING. SOME OF THESE SHOWERS COULD BE HEAVY
TOWARDS THE SJV TONIGHT WITH SLOW STORM MOTIONS ALONG THE FRONTAL
BOUNDARY. A RUMBLE OF THUNDER IS POSSIBLE WITH SOME RELATIVELY
WEAK ELEVATED CONVECTION AND THE ENTRANCE REGION TO A WEAK UPPER
JET. SOUTH OF THE SJV...PRECIP AMOUNTS ARE EXPECTED TO TAPER
TOWARDS A QUARTER INCH NEAR CARIBOU...LESS THAN A TENTH OF AN INCH
NEAR HOULTON AND JUST A FEW HUNDREDTHS OF AN INCH TOWARDS BANGOR.
THE BIGGEST ISSUE DOWN EAST WILL BE FOG CREEPING BACK NORTHWARD
FROM THE GULF OF MAINE TOWARDS THE FRONT. WITH CLOUD COVER AND
SHOWERS...LOWS TONIGHT WILL ONLY DROP INTO THE UPPER 50S EXCEPT
SOME LOWER 50S ALONG THE COAST.
THE FRONT WILL SLOWLY REACH DOWN EAST BY WEDNESDAY MORNING. THE
CROWN OF MAINE WILL QUICKLY CLEAR OUT AND EXPERIENCE SUNSHINE WITH
LOW HUMIDITY. CLOUD COVER AND HIGHER HUMIDITY WILL LINGER DOWN
EAST THROUGH THE MORNING WITH A FEW SHOWERS. CLEARING SKIES SHOULD
PUSH SOUTHWARD INTO DOWN EAST ZONES DURING THE AFTERNOON. HIGHS
WILL REACH THE LOW 70S IN THE NORTHERN HALF OF THE FORECAST AREA
AND MID 70S FOR MOST OF DOWN EAST EXCEPT THE COAST WHERE UPPER 60S
TO LOW 70S ARE EXPECTED.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM THURSDAY/...
A LARGE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BUILD BACK OVER
THE STATE ON WEDNESDAY BRINGING MORE WARM WEATHER WHICH WILL LAST
THROUGH THE END OF THE WEEK. A SOUTHERLY FLOW RESULTING FROM HIGH
PRESSURE OFF TO THE EAST COMBINED WITH LOW PRESSURE LIFTING INTO
THE GREAT LAKES STATES WILL ALSO BRING INCREASING HUMIDITY.
THURSDAY WILL BRING PARTIAL SUNSHINE WITH A WARM AFTERNOON. SOME
ISOLATED SHOWERS AND POSSIBLY A STRAY THUNDERSTORM MAY AFFECT
WESTERN AREAS THURSDAY AFTERNOON AS MOISTURE LIFTS NORTH AROUND
THE ATLANTIC HIGH. THURSDAY NIGHT WILL BE PARTLY CLOUDY. HUMID AIR
WILL RESULT IN A WARM NIGHT. A SOUTHERLY BREEZE WILL INCREASE ON
FRIDAY AS THE GRADIENT TIGHTENS AHEAD OF AN APPROACHING COLD
FRONT. THE DAY WILL BE PARTLY SUNNY AND WARM AND A STRAY SHOWER OR
THUNDERSHOWER WILL BE POSSIBLE IN SOME WESTERN AND SOUTHERN SPOTS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
MODELS IN FAIRLY GOOD AGREEMENT WITH COLD FRONT CROSSING THE STATE
FRIDAY NIGHT WITH SHOWERS MAINLY ACROSS NORTHERN SECTIONS. HIGH
PRESSURE CENTERED OVER JAMES BAY WILL THEN BUILD ACROSS THE REGION
SATURDAY THROUGH SUNDAY WITH FAIR CONDITIONS. GFS IS INDICATING
WEAK IMPULSE COULD PROVIDE SHOWERS ACROSS THE AREA LATE SUNDAY BUT
OTHER MODELS FARTHER SOUTH WITH THIS FEATURE SO FOR NOW WILL KEEP
SHOWERS EITHER CHANCE OR SLIGHT CHANCE AND CONFINED TO NORTHWEST
SECTIONS AND DOWNEAST. AT THIS TIME, MEMORIAL DAY LOOKS TO BE DRY
WITH NEXT LOW PRESSURE AFFECTING THE REGION MONDAY NIGHT INTO
TUESDAY.
&&
.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: MOIST AIRMASS AHEAD OF THE COLD FRONT WILL BRING ALL
TERMINALS TO IFR TONIGHT WITH VLIFR POSSIBLE CLOSER TO THE COAST
FOR LOCATIONS SUCH AS BHB AND BGR. THE COLD FRONT WILL BRING
CONDITIONS TO VFR NORTH OF HUL WEDS MORNING AND VFR IS EXPECTED TO
REACH BGR AND BHB BY MIDDAY.
SHORT TERM: GENERALLY VFR CONDITIONS ARE EXPECTED WEDNESDAY NIGHT
THROUGH FRIDAY ALTHOUGH SOME PATCHY LOW CLOUDS OR FOG MAY BRIEFLY
LOWER CONDITIONS TO IFR EARLY THURSDAY MORNING OR FRIDAY MORNING.
EXPECT VFR CONDITIONS FRIDAY NIGHT THROUGH SUNDAY.
&&
.MARINE...
NEAR TERM: UPDATE...BASED ON LATEST BUOY OBS WHICH ONLY SHOW WV
HTS OF ARND 3 FT ON BUOYS OVR AND NEAR OUR OUTER MZS...WE OPTD TO
PUSH BACK THE BEGINNING OF THE SCA FOR HAZ SEAS OVR THE OUTER MZS
UNTIL 0400 AM LDT.
ORGNL DISC...A SE SWELL WILL BRING LONG PERIOD WAVE HTS TO 6
FEET IN THE OUTER WATERS...MEETING SCA CRITERIA FOR HAZARDOUS
SEAS. WILL ISSUE SCA FOR 11PM TONIGHT THROUGH WEDNESDAY AFTERNOON.
WINDS WILL REMAIN LIGHT.
SHORT TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA
LEVELS WEDNESDAY NIGHT THROUGH FRIDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM EDT THIS
AFTERNOON FOR ANZ050-051.
&&
$$
NEAR TERM...KHW/VJN/MCW
SHORT TERM...BLOOMER
LONG TERM...FOSTER
AVIATION...KHW
MARINE...KHW/VJN/MCW/BLOOMER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
429 PM EDT WED MAY 23 2012
.SYNOPSIS...
ISSUED AT 427 PM EDT WED MAY 23 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE NW CONUS AND A RIDGE FROM THE CNTRL GREAT LAKES INTO NRN
ONTARIO RESULTING IN SW FLOW FROM THE CNTRL PLAINS TO THE UPPER MS
VALLEY AND LAKE SUPERIOR. AT THE SFC...SRLY WINDS WERE INCREASING
ACROSS THE REGION AHEAD A COLD FRONT EXTENDING THROUGH THE ERN
DAKOTAS FROM LOW PRESSURE OVER SRN MANITOBA. AN AREA OF TSRA WAS
MOVING NE THROUGH N CNTRL MN SUPPORTED A SHRTWV NEAR THE NOSE OS
STRONG 925-850 MB THETA-E ADVECTION. OVER UPPER MI...VIS LOOP AND
SFC OBS SHOWED CONSIDERABLE HIGH CLOUDS IN THE BROAD WAA PATTERN
AHEAD OF THE FRONT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 427 PM EDT WED MAY 23 2012
TONIGHT...AS A SHRTWV OVER NW MN LIFTS TO THE NE AND
THE NEXT SIGNIFICANT UPSTREAM SHRTWV OVER NEVADA ROTATES THROUGH
THE WRN TROF...ANOTHER SFC LOW WILL DEVELOP IN THE PLAINS AND
MOVE NNEWD ON COLD FNT ATTENDANT TO FIRST SFC LO DRIFTING THRU NW
ONTARIO. EXPECT THAT THE GREATEST CHANCE FOR SHRA/TSRA WILL REMAIN
CLOSER TO THE FRONT AND NEAR THE AXIS OF GREATER
MOISTURE/INSTABILITY OVER MN AND FAVORABLE UPPER LEVEL DIV WITH THE
RIGHT ENTRANCE OF THE JET OVER NW ONTARIO. SO...THE NAM/REGIONAL
GEM/ECMWF WERE PREFERRED WITH THE SHRA/TSRA PLACEMENT COMPARED TO
THE GFS WHICH SEEMED OVERLY AGGRESSIVE IN PUSHING THE PCPN TO THE
EAST.
THURSDAY...THE MAIN SHRTWV LIFTS OUT OF THE PLAINS TO THE UPPER MS
VALLEY SUPPORTING A CONSOLIDATED SFC LOW TO NEAR KDLH BY 00Z/FRI.
GIVEN THE STRENGTHENING DYNAMICS AGAIN TO THE WEST...CONTINUED TO
DELAY THE EASTWARD PROGRESSION OF THE SHRA/TSRA INTO UPPER MI TIL
MAINLY LATE IN THE DAY. MLCAPE VALUES TO AROUND 1K J/KG WITH
AFTERNOON HEATING AND SFC DEWPOINTS NEAR 60 WILL SUPPORT TSRA
CHANCES FROM IWD-CMX...MAINLY AFT 21Z. WITH INVERTED V LOOK TO THE
SOUNDINGS AND VERY STRONG MAINLY UNIDIRECTIONAL WIND FIELD (700 MB
WINDS TO NEAR 70KT)...EXPECT THAT DAMAGING WINDS WILL BE THE MAIN
HAZARD WITH ANY TSRA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 427 PM EDT WED MAY 23 2012
MAIN CONCERN FOR THE LONG TERM PERIOD IS THE SEVERE WEATHER
POTENTIAL AT THE BEGINNING OF THE PERIOD.
STATIONARY FRONT WILL BE SETUP OVER WRN LK SUPERIOR...WHILE A FAIRLY
POTENT SHORTWAVE PUSHING NE ACROSS AT LEAST THE WRN HALF OF THE CWA
THURS NIGHT. THIS WILL LEAD TO ONGOING CYCLOGENESIS OVER NW WI
DURING THE LATE AFTERNOON AND THE LOW MOVING NNE ACROSS WRN LK
SUPERIOR DURING THE EVENING. EXPECT THUNDERSTORMS TO BE ONGOING
OVER NW WI AND FAR WRN LK SUPERIOR AT THE START OF THE PERIOD AND
THEN MOVE E AND NE AS THE COLD FRONT PUSHES THROUGH THE CWA DURING
THE NIGHT.
WITH THE STRONG WINDS ALOFT AND THE CYCLOGENESIS...FEEL THAT THERE
IS A DECENT CHANCE OF SEVERE WEATHER OVER THE WRN HALF OF THE CWA
TOMORROW EVENING. THERE IS A VERY THIN CORRIDOR OF MLCAPE VALUES
APPROACHING 500-1000 J/KG OVER THE WRN THIRD OF THE CWA AND
INSTABILITY MAY BE THE MAIN LIMITING FACTOR AS STORMS MOVE INTO THE
CWA. CAPE FAIRLY SKINNY...NCAPE VALUES AROUND 0.1...SO DON/T EXPECT
MUCH MORE THAN MARGINALLY SEVERE HAIL.
WIND APPEARS TO BE BIGGEST THREAT WITH THE STORMS. INVERTED V LOOK
TO THE SOUNDINGS OVER THE WEST AND DCAPE VALUES OF 600-800 J/KG.
STRONG WINDS ALOFT...APPROACHING 70-80KTS AT H700 AND
40-50KTS JUST A COUPLE HUNDRED FEET ABOVE THE SFC...WILL BE
AIDED BY A POCKET OF DRY H700-500 AIR AND STEEPER LAPSE RATES.
THIS...COMBINED WITH STORM MOTION TO THE NNE AT 65-70KTS ALL POINT
TO THE POTENTIAL FOR DAMAGING WINDS WHERE THUNDERSTORMS...AND
POTENTIALLY EVEN SHOWERS OCCUR. WITH THE LOW DEVELOPING ALONG THE
FRONT POTENTIALLY AFFECTING THE LLVL WIND FIELD...COULD SEE SOME
LLVL BACKING OF THE WINDS AND PRODUCE SOME ROTATING UPDRAFTS AND
SUPERCELLS...ESPECIALLY OVER NW WI. BUT THE EXPECTED DRY LLVL AIR
HELPING PRODUCE AN INVERTED V AND LCL HEIGHTS TOWARDS 3-3.5KFT
SHOULD LIMIT TORNADO POTENTIAL THIS FAR N.
CURRENT THOUGHT IS BEST CHANCES FOR SEVERE SHOULD BE FROM
BARAGA/IRON COUNTIES AND WEST...BUT WITH THE STORM MOTIONS...COULD
POTENTIALLY AFFECT MARQUETTE/DICKINSON/MENOMINEE COUNTIES BEFORE
HEADING OVER LK SUPERIOR. ADDED DAMAGING WIND THREAT TO THE GRIDS
AND MENTIONED IN THE HWO. THIS MATCHES UP WELL WHERE SPC HAS A
SLIGHT RISK...WITH HATCHED AREA JUST TO THE SW OF THE CWA.
AS THE LOW QUICKLY LIFTS NE...EXPECT BEST FORCING TO QUICKLY
DEPART OVERNIGHT AND PULL FORCING WITH IT. IN ADDITION...AS THE COLD
FRONT PUSHES EAST INTO THE CNTRL/ERN CWA...THE CAPPING BECOMES
STRONGER. WITH THE COMBINATION OF LOOSING FORCING AND MORE
UNFAVORABLE ENVIRONMENT...EXPECT THE SHOWERS/THUNDERSTORMS TO
DIMINISH AS THEY MOVE INTO THE CNTRL/ERN CWA. 09Z SREF ALSO SHOWING
THIS DIMINISHING TREND IN THE 3HR CALIBRATED THUNDERSTORM PROBS...AS
THE SHOWERS/THUNDERSTORMS PUSH TO THE NE OVER LK SUPERIOR DURING THE
OVERNIGHT HOURS.
EXPECT GUSTY SE WINDS IN THE EVENING AHEAD OF THE LOW AND OVER THE
KEWEENAW OVERNIGHT BEHIND THE LOW/FRONT. BUMPED UP WINDS
SIGNIFICANTLY OVER THE KEWEENAW BEHIND THE LOW AND FRONT...WITH THE
STRONG WINDS JUST ABOVE THE SFC /NAM SHOWING 60KTS AT 1.5KFT/. IN
ADDITION...GOOD ISALLOBARIC COMPONENT TO THE WINDS OVER THE WEST
OVERNIGHT WITH THE INTENSIFYING LOW PUSHING NE. ONLY CONCERN FOR
GOING MORE THAN 30-35KTS AT THIS POINT IS AFFECT OF COOLER WATER
TEMPS...BUT THAT MAY NOT HAVE MUCH EFFECT OVER THE HIGHER TERRAIN.
FRI...GUSTY WRLY WINDS...30-35KTS...IN THE MORNING BEHIND THE LOW.
DRIER AIR MOVING IN AND H700 CAP SHOULD LIMIT DEVELOPMENT EVEN WITH
WEAK MID-LVL WAVE MOVING THROUGH. DEEP MOISTURE IS LIMITED AND ML/MU
CAPE VALUES ARE BELOW 100 JKG WOULD LEAD TO LITTLE/NO PCPN CHANCES.
LATEST NAM RUN HAS BACKED OFF ON PCPN AND WILL FOLLOW SUIT WITH
REMOVING SLIGHT CHANCES. WILL KEEP SKIES PARTLY/MOSTLY CLOUDY DURING
THE AFTN WITH EXPECTED DIURNAL CU DEVELOPMENT.
MIXING TO H750 WOULD YIELD HIGHS IN THE 70S...WITH THE HIGHEST
VALUES IN THE FAVORED DOWNSLOPE AREAS OF THE CNTRL. WITH THE GUSTY
WINDS AND DEEPER MIXING INTO THE LIMITED MOISTURE ALOFT...EXPECT RH
VALUES TO FALL TO 30 PERCENT. FIRE WX CONCERNS MAINLY OVER THE
CNTRL...WHERE LESS RAIN IS EXPECTED ON THURS NIGHT.
FRI NIGHT...WEAK HIGH PRESSURE RIDGE FROM HIGH JUST N OF MN. SFC LOW
DEVELOPING IN THE CNTRL PLAINS IN RESPONSE TO DEEP UPPER TROUGH
OVER THE WRN CONUS WILL BEGIN TO PUSH A WARM FRONT N TOWARDS THE
UPPER GREAT LAKES LATE FRI NIGHT. COULD PRODUCE A FEW SHOWERS
TOWARDS THE WI BORDER LATE.
CWA WILL BE ON THE E SIDE OF THE UPPER RIDGE AXIS STRETCHING FROM
THE OHIO VALLEY TO LK WINNIPEG UNTIL SUN NIGHT. STILL SEVERAL WEAK
DISTURBANCES PUSHING THROUGH THE FLOW SAT AFTN THROUGH SUN NIGHT.
THE WARM FRONT WILL CONTINUE TO SLOWLY PUSH NE ON SAT...AS IT
BATTLES THE HIGH THAT WILL HAVE MOVED EAST OVER ONTARIO. PCPN
CHANCES ON SAT WILL LARGELY DEPEND ON HOW FAR N THE FRONT WILL PUSH.
BEST CHANCES LOOK TO BE ON SAT NIGHT INTO SUN...AS THE FRONT MOVES
INTO NRN WI AND FINALLY INTO UPPER MI BY SUN AFTN. THIS WILL PUT THE
BEST WAA FOCUS OVER THE CWA. THERE ARE DECENT MID LEVEL LAPSE
RATES...BUT ELEVATED CAPES ARE NOT TOO IMPRESSIVE...SO HAVE CAPPED
THUNDER TO CHANCES FOR SAT NIGHT INTO SUN. WITH THE CONVECTION
LIKELY TO BE ELEVATED...THE MAIN THREAT WOULD BE SMALL HAIL AND
HEAVY RAIN.
CWA WILL BE UNDER THE WARM SECTOR LATE SUN AFTN AND INTO SUN
NIGHT...WITH MODELS DIVERGING WITH THE HANDLING OF THE LOW HEADING
INTO THE FIRST PART OF NEXT WEEK. 12Z GFS SHOWS THE LOW CONTINUING
NNE INTO SRN CANADA ON SUN NIGHT AND MONDAY WHILE PUSHING COLD FRONT
ACROSS UPPER MI ON MON. 00Z ECMWF ON THE OTHERHAND DISSIPATES THE
LOW OVER THE CWA AND THEN SLOWLY SLIDES IT EAST THROUGH TUES. AFTER
A MORE ACTIVE PERIOD...OVERALL TREND LOOKS TO BE TOWARDS A SLIGHTLY
DRIER/QUIET WEATHER TOWARDS THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 133 PM EDT WED MAY 23 2012
STRONG SOUTH WINDS WILL BE THE MAIN CONCERN DURING THE TAF PERIOD.
WITH THE LOSS OF DAYTIME HEAVINT...LLWS WILL BE LIKELY TONIGHT AT
ALL 3 SITES...EVEN WITH IWD KEEPING GUSTS AT OR ABOVE 20KTS THROUGH
THE OVERNIGHT HOURS. OTHERWISE...VFR CEILINGS AND VIS SHOULD
REMAIN...WITH ONLY SOME LIGHTER SHOWERS POSSIBLE LATE TONIGHT AND
EARLY THURSDAY AT IWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 PM EDT WED MAY 23 2012
LOW PRESSURE OVER S MANITOBA WILL PUSH INTO ONTARIO TONIGHT AND
THURSDAY...AS AN ADDITIONAL LOW MOVES FROM THE CENTRAL PLAINS TO W
LS FRIDAY AFTERNOON. EXPECT THE LOW TO CONTINUE A NE TRACK ACROSS
ONTARIO THROUGH FRIDAY...WITH A TROUGH LINGERING ACROSS LAKE
SUPERIOR. STRENGTHENING S WINDS WILL PREVAIL AHEAD OF THIS SYSTEM
TONIGHT THROUGH THURSDAY. WITH A STABLE TEMPERATURE PROFILE THE
STRONGEST WINDS...EXPECT THE STRONGEST ACROSS THE TALLER OBSERVING
PLATFORMS ACROSS CENTRAL LAKE SUPERIOR.
HIGH PRESSURE OVER CENTRAL CANADA FRIDAY NIGHT WILL SLIDE ACROSS
ONTARIO SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. AS A
RESULT...A RIDGE WILL SLIDE ACROSS LS SATURDAY...WITH LIGHTER WINDS
TAKING HOLD. A LOW ACROSS THE CENTRAL PLAINS WILL FILL ACROSS MN
SUNDAY INTO SUNDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
133 PM EDT WED MAY 23 2012
.SYNOPSIS...
ISSUED AT 734 AM EDT WED MAY 23 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG FM THE UPR
MS RIVER VALLEY BTWN A TROF OVER THE PAC NW AND ANOTHER IN QUEBEC.
AT THE SFC...THERE IS A 996MB LO PRES OVER THE NRN PLAINS ASSOCIATED
WITH A SHRTWV/100KT H3 JET MAX LIFTING OUT OF THE WRN TROF. WARM FNT
E OF THIS LO RUNS ACRS NRN MN TO NEAR THE CWA/WI BORDER. THERE ARE
SOME SCT -SHRA OVER UPR MI N OF THIS WARM FNT EARLY THIS MRNG IN
AREA OF SOME ISENTROPIC ASCENT/MSTR BEST SHOWN ON THE 305K SFC
/ABOUT H7/...BUT COVERAGE/INTENSITY IS LIMITED BY VERY DRY AIR IN
THE WARM SECTOR AS SHOWN ON THE 00Z MPX RAOB AND ALSO THE 00Z GRB
RAOB. IN FACT...SFC DEWPTS IN THE WARM SECTOR MIXED OUT TO AROUND 40
OVER IOWA/SRN MN YDAY AFTN WITH HI TEMPS RISING WELL INTO THE 80S.
EXCEPT FOR SOME HI CLDS SPILLING E FM SHRA/TS CLOSER TO THE SFC
LO...SKIES ARE MOCLR OVER MUCH OF MN/WI S OF THE WARM FNT.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY EVENING)
ISSUED AT 734 AM EDT WED MAY 23 2012
MAIN FCST CONCERNS INTO THU ARE MAINLY FIRE WX RELATED FOLLOWING
EXPECTED WARM FROPA THIS MRNG. FOCUS FOR LATER THU AND THU NGT TURN
TO POPS WITH APRCH OF COLD FNT FM THE W.
TODAY...AS SFC LO PRES IN THE NRN PLAINS DRIFTS NEWD TOWARD FAR NW
ONTARIO BY 00Z FRI...ATTENDANT WARM FNT WL LIFT NEWD ACRS THE CWA
AND INTO ONTARIO THIS AFTN. WITH THIS SHIFT AND DEPARTURE OF DEEPER
MSTR ON THE 305K ISENTROPIC SFC TO THE NE...EXPECT LINGERING -SHRA
AND THICKER CLDS OVER UPR MI TO LIFT OUT INTO LK SUP EARLY THIS
MRNG. ONCE THE WARM SECTOR MOVES INTO THE CWA WITH H85 TEMPS RISING
AS HI AS 17-18C...EXPECT HI TEMPS TO TOP OUT 80 TO 85 PER MIXING TO
H8 ON FCST SDNGS OVER PORTIONS OF THE W HALF AWAY FM THE MODERATING
INFLUENCE OF LK MI. WITH DAYTIME MIXING OUT THE H100-85 WINDS UP TO
30 KTS AND CAUSING SFC DEWPTS TO FALL AS LO AS 37 TO 45 IN THE AFTN
PER UPSTREAM OBS YDAY...MIN RH/FIRE WX PARAMETERS WL AT LEAST APRCH
CRITICAL LVLS. OPTED TO ISSUE A WILDFIRE POTENTIAL STATEMENT FOR NOW
AND LET THE DAYSHIFT COORDINATE WITH THE USERS ON HEADLINES AS
NECESSARY.
TNGT...AS NEXT SHRTWV ROTATES THRU THE WRN TROF UPSTREAM OF BLDG RDG
OVER THE ERN CONUS...ANOTHER SFC LO PRES WL TAKE SHAPE IN THE PLAINS
AND MOVE NNEWD ON COLD FNT ATTENDANT TO FIRST SFC LO DRIFTING THRU
NW ONTARIO. UNDER THESE CIRCUMSTANCES...THINK THE 00Z NAM AND
ESPECIALLY THE GFS ARE TOO PROGRESSIVE PUSHING PCPN INTO THE WRN
CWA. SO TENDED TO FOLLOW THE SLOWER 00Z CNDN AND LOCAL WRF-ARW/12Z
ECMWF GUIDANCE. EVEN THOUGH SKIES WL REMAIN MOCLR OVER AT LEAST THE
E HALF UNDER AXIS OF DRIEST AIR/HIEST H5...STEADY S WIND WL RESTRICT
THE DIURNAL TEMP DROP. THE OVERNGT WL BE ESPECIALLY WARM AND RH
RECOVER PARTICULARLY POOR OVER THE W IN THE DOWNSLOPE AREAS NEAR LK
SUP AND WHERE AT LEAST THICKER HI CLDS WL MOVE OVHD.
THU...AS THE PRIME SHRTWV DRIVES NEWD TOWARD THE UPR LKS AND SFC LO
SHIFTS NEAR WRN UPR MI...EXPECT INCRSG POPS OVER ESPECIALLY THE W
WITH SOME DPVA/H5 FALLS/UPR DVGC IN RRQ OF UPR JET MAX IN NW ONTARIO
AND RETURN OF LLVL MSTR IN THE PRESENCE OF DAYTIME HEATING. MOST OF
THE MODELS ARE ACTUALLY IN FAIRLY GOOD AGREEMENT ON THESE DETAILS.
ALTHOUGH GUIDANCE SUGS MOST OF THE SHRA/TS WL FALL ON THE COLD SIDE
OF THE ACCOMPANYING FNT THAT REACHES THE WRN ZNS WITH THE SFC LO
LATE IN THE DAY...SPC HAS INCLUDED MUCH OF THE W HALF OF THE CWA IN
A SLGT RISK FOR SVR TS. FCST NAM SDNG FOR IWD LATE IN THE DAY
INDICATES SBCAPE REACHING ARND 1000J/KG FOR SFC T/TD 79/60 NEAR
FROPA TIME. OVERALL LAPSE RATES DO NOT LOOK TOO IMPRESSIVE WITH
FAIRLY NARROW SKINNY CAPE...BUT STRONG WIND FIELDS UP TO 60KT/50KT
AT H7/H85 AND PRESENCE OF INVERTED V T/TD PROFILE BLO H8 SUG THE
POTENTIAL FOR SOME DAMAGING WINDS IF ENUF LLVL MSTR CAN SURGE AHEAD
OF THE FNT TO SUPPORT TS COINCIDENT WITH THE FROPA AND NOT JUST ON
THE COLD SIDE OF THE BNDRY. FARTHER TO THE E...THE DAY SHOULD BE
BREEZY AND WARM...BUT A RETURN OF HIER H85 DEWPTS/MIXING OF THIS
MOISTER AIR TO THE SFC SHOULD LIMIT HOW BAD THE FIRE WX PARAMETERS
GO.
THU NGT...AS SHRTWV/SFC LO DRIVE NEWD THRU ONTARIO...ATTENDANT COLD
FNT WL SWEEP ACRS THE CWA...PASSING ERY LATE. SINCE THE SHARPER
DVPA/DEEP LYR QVECTOR CNVGC TEND TO LIFT NEWD INTO ONTARIO WITH THE
SHRTWV...SUSPECT THE MODELS AND ESPECIALLY THE NAM MIGHT BE ON THE
RIGHT TRACK SHOWING A DCRSG TREND FOR FNTL SHRA/TS...ESPECIALLY LATE
WITH LOSS OF ANY DIURNAL HEATING. A GUSTY W WIND IN THE WAKE OF THE
FROPA WITH WNW H925 WINDS UP TO 40 KTS WL DRIVE COOLER AIR/H85 TEMPS
DOWN TO 8C INTO THE CWA OVERNGT.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 528 AM EDT WED MAY 23 2012
WENT WARMER /ABOUT 5F/ AND WINDIER FOR FRIDAY. WHILE MUCH OF THE
WARMER AIR AND PRECIP WILL EXIT EAST WITH THE COLD FRONT EXITING
EAST IN THE MORNING...THE SFC TROUGH WILL LINGER OVERHEAD WITH WSW
WINDS AT THE SFC. EXPECT 850MB TEMPS TO FALL FROM THE MID TEENS C TO
AROUND 10C AROUND DAYBREAK FRIDAY...AND REMAIN STEADY AROUND THIS
LEVEL THROUGH SATURDAY. COULD NOT GET RID OF PRECIPITATION ALL
TOGETHER FOR...GIVEN 120KT 250MB JET STREAMING ACROSS UPPER
MICHIGAN...AND A KICKER OF A SHORTWAVE ALOFT. THERE IS SIGNIFICANT
TIMING/STRENGTH DIFFERENCES WITH THIS FEATURE. AS A RESULT...THE
CHANCE OF PRECIP/TS WAS LIMITED TO SLIGHT CHANCE. THE 23/00Z GFS
DOES SHOW AROUND A QUARTER OF AN INCH OF LIQUID CENTRAL DURING THE
AFTERNOON HOURS...WHILE THE OTHER MODELS ARE MUCH DRIER.
ALTHOUGH HIGH PRESSURE FROM CENTRAL CANADA WILL ATTEMPT TO SINK
ACROSS THE UPPER GREAT LAKES FOR SATURDAY...IT WILL BE PUSHED
EASTWARD...SKIMMING NORTHERN AND EASTERN UPPER MI SATURDAY INTO
SATURDAY NIGHT. MUCH OF THIS WILL BE DUE TO THE NEXT LOW DEVELOPING
OVER THE CENTRAL STATES. THE LOW WILL MOVE TO THE DAKOTAS/NE BY
SUNDAY AFTERNOON...WITH A WARM FRONT QUICKLY PUSHING UP ACROSS THE
CWA AND 850MB TEMPS JUMPING TO AROUND 18C SUNDAY NIGHT INTO MONDAY
MORNING.
THE 23/00Z GFS IS MORE PROGRESSIVE WITH THE SFC LOW...AVERAGING OUT
TO BE ABOUT 6 HOURS QUICKER THAN THE 23/00Z ECMWF FROM SATURDAY
NIGHT THROUGH EARLY MONDAY AFTERNOON. THE SLOW MOVING SYSTEM WILL
CONTINUE TO INFLUENCE OUR WEATHER THROUGH THE START OF THE NEXT WORK
WEEK...WITH A CHANCE OF SHOWERS LINGERING THROUGH MONDAY.
TEMPERATURES WILL EVENTUALLY COOL TUESDAY...BACK TO BELOW NORMAL
READINGS /MAINLY IN THE 50S TO MID 60S/.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 133 PM EDT WED MAY 23 2012
STRONG SOUTH WINDS WILL BE THE MAIN CONCERN DURING THE TAF PERIOD.
WITH THE LOSS OF DAYTIME HEAVINT...LLWS WILL BE LIKELY TONIGHT AT
ALL 3 SITES...EVEN WITH IWD KEEPING GUSTS AT OR ABOVE 20KTS THROUGH
THE OVERNIGHT HOURS. OTHERWISE...VFR CEILINGS AND VIS SHOULD
REMAIN...WITH ONLY SOME LIGHTER SHOWERS POSSIBLE LATE TONIGHT AND
EARLY THURSDAY AT IWD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 528 AM EDT WED MAY 23 2012
LOW PRESSURE OVER S MANITOBA WILL PUSH INTO ONTARIO TONIGHT AND
THURSDAY...AS AN ADDITIONAL LOW MOVES FROM THE CENTRAL PLAINS TO W
LS FRIDAY AFTERNOON. EXPECT THE LOW TO CONTINUE A NE TRACK ACROSS
ONTARIO THROUGH FRIDAY...WITH A TROUGH LINGERING ACROSS LAKE
SUPERIOR. STRENGTHENING S WINDS WILL BE THE RULE AHEAD OF THIS
SYSTEM TODAY THROUGH TOMORROW...STRONGEST ACROSS THE TALLER
OBSERVING PLATFORMS ACROSS CENTRAL LS.
HIGH PRESSURE OVER CENTRAL CANADA FRIDAY NIGHT WILL SLIDE ACROSS
ONTARIO SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. AS A
RESULT...A RIDGE WILL SLIDE ACROSS LS SATURDAY...WITH LIGHTER WINDS
TAKING HOLD. A LOW ACROSS THE CENTRAL PLAINS WILL FILL ACROSS MN
SUNDAY INTO SUNDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...KF
AVIATION...JLB
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
735 AM EDT WED MAY 23 2012
.SYNOPSIS...
ISSUED AT 734 AM EDT WED MAY 23 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG FM THE UPR
MS RIVER VALLEY BTWN A TROF OVER THE PAC NW AND ANOTHER IN QUEBEC.
AT THE SFC...THERE IS A 996MB LO PRES OVER THE NRN PLAINS ASSOCIATED
WITH A SHRTWV/100KT H3 JET MAX LIFTING OUT OF THE WRN TROF. WARM FNT
E OF THIS LO RUNS ACRS NRN MN TO NEAR THE CWA/WI BORDER. THERE ARE
SOME SCT -SHRA OVER UPR MI N OF THIS WARM FNT EARLY THIS MRNG IN
AREA OF SOME ISENTROPIC ASCENT/MSTR BEST SHOWN ON THE 305K SFC
/ABOUT H7/...BUT COVERAGE/INTENSITY IS LIMITED BY VERY DRY AIR IN
THE WARM SECTOR AS SHOWN ON THE 00Z MPX RAOB AND ALSO THE 00Z GRB
RAOB. IN FACT...SFC DEWPTS IN THE WARM SECTOR MIXED OUT TO AROUND 40
OVER IOWA/SRN MN YDAY AFTN WITH HI TEMPS RISING WELL INTO THE 80S.
EXCEPT FOR SOME HI CLDS SPILLING E FM SHRA/TS CLOSER TO THE SFC
LO...SKIES ARE MOCLR OVER MUCH OF MN/WI S OF THE WARM FNT.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY EVENING)
ISSUED AT 734 AM EDT WED MAY 23 2012
MAIN FCST CONCERNS INTO THU ARE MAINLY FIRE WX RELATED FOLLOWING
EXPECTED WARM FROPA THIS MRNG. FOCUS FOR LATER THU AND THU NGT TURN
TO POPS WITH APRCH OF COLD FNT FM THE W.
TODAY...AS SFC LO PRES IN THE NRN PLAINS DRIFTS NEWD TOWARD FAR NW
ONTARIO BY 00Z FRI...ATTENDANT WARM FNT WL LIFT NEWD ACRS THE CWA
AND INTO ONTARIO THIS AFTN. WITH THIS SHIFT AND DEPARTURE OF DEEPER
MSTR ON THE 305K ISENTROPIC SFC TO THE NE...EXPECT LINGERING -SHRA
AND THICKER CLDS OVER UPR MI TO LIFT OUT INTO LK SUP EARLY THIS
MRNG. ONCE THE WARM SECTOR MOVES INTO THE CWA WITH H85 TEMPS RISING
AS HI AS 17-18C...EXPECT HI TEMPS TO TOP OUT 80 TO 85 PER MIXING TO
H8 ON FCST SDNGS OVER PORTIONS OF THE W HALF AWAY FM THE MODERATING
INFLUENCE OF LK MI. WITH DAYTIME MIXING OUT THE H100-85 WINDS UP TO
30 KTS AND CAUSING SFC DEWPTS TO FALL AS LO AS 37 TO 45 IN THE AFTN
PER UPSTREAM OBS YDAY...MIN RH/FIRE WX PARAMETERS WL AT LEAST APRCH
CRITICAL LVLS. OPTED TO ISSUE A WILDFIRE POTENTIAL STATEMENT FOR NOW
AND LET THE DAYSHIFT COORDINATE WITH THE USERS ON HEADLINES AS
NECESSARY.
TNGT...AS NEXT SHRTWV ROTATES THRU THE WRN TROF UPSTREAM OF BLDG RDG
OVER THE ERN CONUS...ANOTHER SFC LO PRES WL TAKE SHAPE IN THE PLAINS
AND MOVE NNEWD ON COLD FNT ATTENDANT TO FIRST SFC LO DRIFTING THRU
NW ONTARIO. UNDER THESE CIRCUMSTANCES...THINK THE 00Z NAM AND
ESPECIALLY THE GFS ARE TOO PROGRESSIVE PUSHING PCPN INTO THE WRN
CWA. SO TENDED TO FOLLOW THE SLOWER 00Z CNDN AND LOCAL WRF-ARW/12Z
ECMWF GUIDANCE. EVEN THOUGH SKIES WL REMAIN MOCLR OVER AT LEAST THE
E HALF UNDER AXIS OF DRIEST AIR/HIEST H5...STEADY S WIND WL RESTRICT
THE DIURNAL TEMP DROP. THE OVERNGT WL BE ESPECIALLY WARM AND RH
RECOVER PARTICULARLY POOR OVER THE W IN THE DOWNSLOPE AREAS NEAR LK
SUP AND WHERE AT LEAST THICKER HI CLDS WL MOVE OVHD.
THU...AS THE PRIME SHRTWV DRIVES NEWD TOWARD THE UPR LKS AND SFC LO
SHIFTS NEAR WRN UPR MI...EXPECT INCRSG POPS OVER ESPECIALLY THE W
WITH SOME DPVA/H5 FALLS/UPR DVGC IN RRQ OF UPR JET MAX IN NW ONTARIO
AND RETURN OF LLVL MSTR IN THE PRESENCE OF DAYTIME HEATING. MOST OF
THE MODELS ARE ACTUALLY IN FAIRLY GOOD AGREEMENT ON THESE DETAILS.
ALTHOUGH GUIDANCE SUGS MOST OF THE SHRA/TS WL FALL ON THE COLD SIDE
OF THE ACCOMPANYING FNT THAT REACHES THE WRN ZNS WITH THE SFC LO
LATE IN THE DAY...SPC HAS INCLUDED MUCH OF THE W HALF OF THE CWA IN
A SLGT RISK FOR SVR TS. FCST NAM SDNG FOR IWD LATE IN THE DAY
INDICATES SBCAPE REACHING ARND 1000J/KG FOR SFC T/TD 79/60 NEAR
FROPA TIME. OVERALL LAPSE RATES DO NOT LOOK TOO IMPRESSIVE WITH
FAIRLY NARROW SKINNY CAPE...BUT STRONG WIND FIELDS UP TO 60KT/50KT
AT H7/H85 AND PRESENCE OF INVERTED V T/TD PROFILE BLO H8 SUG THE
POTENTIAL FOR SOME DAMAGING WINDS IF ENUF LLVL MSTR CAN SURGE AHEAD
OF THE FNT TO SUPPORT TS COINCIDENT WITH THE FROPA AND NOT JUST ON
THE COLD SIDE OF THE BNDRY. FARTHER TO THE E...THE DAY SHOULD BE
BREEZY AND WARM...BUT A RETURN OF HIER H85 DEWPTS/MIXING OF THIS
MOISTER AIR TO THE SFC SHOULD LIMIT HOW BAD THE FIRE WX PARAMETERS
GO.
THU NGT...AS SHRTWV/SFC LO DRIVE NEWD THRU ONTARIO...ATTENDANT COLD
FNT WL SWEEP ACRS THE CWA...PASSING ERY LATE. SINCE THE SHARPER
DVPA/DEEP LYR QVECTOR CNVGC TEND TO LIFT NEWD INTO ONTARIO WITH THE
SHRTWV...SUSPECT THE MODELS AND ESPECIALLY THE NAM MIGHT BE ON THE
RIGHT TRACK SHOWING A DCRSG TREND FOR FNTL SHRA/TS...ESPECIALLY LATE
WITH LOSS OF ANY DIURNAL HEATING. A GUSTY W WIND IN THE WAKE OF THE
FROPA WITH WNW H925 WINDS UP TO 40 KTS WL DRIVE COOLER AIR/H85 TEMPS
DOWN TO 8C INTO THE CWA OVERNGT.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 528 AM EDT WED MAY 23 2012
WENT WARMER /ABOUT 5F/ AND WINDIER FOR FRIDAY. WHILE MUCH OF THE
WARMER AIR AND PRECIP WILL EXIT EAST WITH THE COLD FRONT EXITING
EAST IN THE MORNING...THE SFC TROUGH WILL LINGER OVERHEAD WITH WSW
WINDS AT THE SFC. EXPECT 850MB TEMPS TO FALL FROM THE MID TEENS C TO
AROUND 10C AROUND DAYBREAK FRIDAY...AND REMAIN STEADY AROUND THIS
LEVEL THROUGH SATURDAY. COULD NOT GET RID OF PRECIPITATION ALL
TOGETHER FOR...GIVEN 120KT 250MB JET STREAMING ACROSS UPPER
MICHIGAN...AND A KICKER OF A SHORTWAVE ALOFT. THERE IS SIGNIFICANT
TIMING/STRENGTH DIFFERENCES WITH THIS FEATURE. AS A RESULT...THE
CHANCE OF PRECIP/TS WAS LIMITED TO SLIGHT CHANCE. THE 23/00Z GFS
DOES SHOW AROUND A QUARTER OF AN INCH OF LIQUID CENTRAL DURING THE
AFTERNOON HOURS...WHILE THE OTHER MODELS ARE MUCH DRIER.
ALTHOUGH HIGH PRESSURE FROM CENTRAL CANADA WILL ATTEMPT TO SINK
ACROSS THE UPPER GREAT LAKES FOR SATURDAY...IT WILL BE PUSHED
EASTWARD...SKIMMING NORTHERN AND EASTERN UPPER MI SATURDAY INTO
SATURDAY NIGHT. MUCH OF THIS WILL BE DUE TO THE NEXT LOW DEVELOPING
OVER THE CENTRAL STATES. THE LOW WILL MOVE TO THE DAKOTAS/NE BY
SUNDAY AFTERNOON...WITH A WARM FRONT QUICKLY PUSHING UP ACROSS THE
CWA AND 850MB TEMPS JUMPING TO AROUND 18C SUNDAY NIGHT INTO MONDAY
MORNING.
THE 23/00Z GFS IS MORE PROGRESSIVE WITH THE SFC LOW...AVERAGING OUT
TO BE ABOUT 6 HOURS QUICKER THAN THE 23/00Z ECMWF FROM SATURDAY
NIGHT THROUGH EARLY MONDAY AFTERNOON. THE SLOW MOVING SYSTEM WILL
CONTINUE TO INFLUENCE OUR WEATHER THROUGH THE START OF THE NEXT WORK
WEEK...WITH A CHANCE OF SHOWERS LINGERING THROUGH MONDAY.
TEMPERATURES WILL EVENTUALLY COOL TUESDAY...BACK TO BELOW NORMAL
READINGS /MAINLY IN THE 50S TO MID 60S/.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 539 AM EDT WED MAY 23 2012
STRONG WINDS WILL BE THE MAIN CONCERN OVER THE NEXT 24 HOURS...OUT
OF A SOUTHERLY DIRECTION...AHEAD OF LOW PRESSURE STRETCHING FROM S
CENTRAL CANADA THROUGH THE CENTRAL PLAINS STATES. LLWS AT NIGHT WILL
BE LIKELY AT ALL 3 SITS...EVEN WITH IWD LIKELY KEEPING GUSTS AT OR
ABOVE 20KTS THROUGH THE OVERNIGHT HOURS. OTHERWISE...VFR CEILINGS
AND VIS SHOULD REMAIN...WITH ONLY A SMALL CHANCE OF SHOWERS AND/OR
THUNDERSTORMS GETTING TO IWD BY 12Z THURSDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 528 AM EDT WED MAY 23 2012
LOW PRESSURE OVER S MANITOBA WILL PUSH INTO ONTARIO TONIGHT AND
THURSDAY...AS AN ADDITIONAL LOW MOVES FROM THE CENTRAL PLAINS TO W
LS FRIDAY AFTERNOON. EXPECT THE LOW TO CONTINUE A NE TRACK ACROSS
ONTARIO THROUGH FRIDAY...WITH A TROUGH LINGERING ACROSS LAKE
SUPERIOR. STRENGTHENING S WINDS WILL BE THE RULE AHEAD OF THIS
SYSTEM TODAY THROUGH TOMORROW...STRONGEST ACROSS THE TALLER
OBSERVING PLATFORMS ACROSS CENTRAL LS.
HIGH PRESSURE OVER CENTRAL CANADA FRIDAY NIGHT WILL SLIDE ACROSS
ONTARIO SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. AS A
RESULT...A RIDGE WILL SLIDE ACROSS LS SATURDAY...WITH LIGHTER WINDS
TAKING HOLD. A LOW ACROSS THE CENTRAL PLAINS WILL FILL ACROSS MN
SUNDAY INTO SUNDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...KF
AVIATION...KF
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
540 AM EDT WED MAY 23 2012
.SYNOPSIS...
ISSUED AT 528 AM EDT WED MAY 23 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
THE GULF OF ALASKA INTO THE NW CONUS AND A FLAT DOWNSTREAM RIDGE
FROM THE SRN PLAINS TO THE UPPER MS VALLEY RESULTING IN WRLY FLOW
THROUGH THE NRN GREAT LAKES. AT THE SFC...A RIDGE EXTENDED FROM
JAMES BAY THROUGH ERN LAKE SUPERIOR AND LAKE MI INTO THE MID MS
VALLEY. SRLY WINDS WERE INCREASING FROM THE PLAINS INTO MN AHEAD OF
LOW PRES OVER THE WRN DAKOTAS. RADAR AND SFC OBS INDICATED AN AREA
OF MAINLY VIRGA/-SHRA/SPRINKLES OVER WRN UPPER MI SUPPORTED BY
305K-310K ISENTROPIC LIFT.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 528 AM EDT WED MAY 23 2012
TONIGHT...EXPECT THAT THE -SHRA/SPRINKLES WILL CONTINUE TO DIMINISH
AS THEY MOVE TO THE EAST LATE THIS AFTERNOON AND EVENING. WITH THE
INCREASED CLOUD COVER AND SOUTHERLY WINDS TONIGHT...TEMPS WILL ONLY
DROP OFF INTO THE MID 40S INLAND AND LOWER TO MID 50S FOR DOWNSLOPE
LOCATIONS OVER THE WEST HALF.
WEDNESDAY...AS THE HIGH OVER THE LAKE AND THE PLAINS TROUGH SHIFTS
TO THE EAST...THE GRADIENT WILL INCREASE ACROSS UPPER MICHIGAN.
THE MODELS WERE IN GOOD AGREEMENT IN KEEPING THE MOISTURE/LIFT AHEAD
OF THE MID LEVEL AND SFC TROUGH TO THE WEST...GRADUALLY SHIFTING
INTO WRN LAKE SUPERIOR LATE. WITH THE WAA AND SUNSHINE...TEMPS
SHOULD CLIMB INTO THE MID AND UPPER 70S INLAND WITH COOLER READINGS
NEAR LAKE MICHIGAN. MIXING SHOULD ALSO ALSO A DECENT PORTION OF THE
25-30 KT SRLY 925 MB WINDS TO MIX TO THE SFC. INCREASED WILDFIRE
DANGER IS EXPECTED WITH THE COMBINATION OF 15 TO 20 MPH SFC WINDS
AND GUSTS TO 30 MPH ALONG WITH RH VALUES DROPPING TO AROUND 30
PERCENT.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 528 AM EDT WED MAY 23 2012
WENT WARMER /ABOUT 5F/ AND WINDIER FOR FRIDAY. WHILE MUCH OF THE
WARMER AIR AND PRECIP WILL EXIT EAST WITH THE COLD FRONT EXITING
EAST IN THE MORNING...THE SFC TROUGH WILL LINGER OVERHEAD WITH WSW
WINDS AT THE SFC. EXPECT 850MB TEMPS TO FALL FROM THE MID TEENS C TO
AROUND 10C AROUND DAYBREAK FRIDAY...AND REMAIN STEADY AROUND THIS
LEVEL THROUGH SATURDAY. COULD NOT GET RID OF PRECIPITATION ALL
TOGETHER FOR...GIVEN 120KT 250MB JET STREAMING ACROSS UPPER
MICHIGAN...AND A KICKER OF A SHORTWAVE ALOFT. THERE IS SIGNIFICANT
TIMING/STRENGTH DIFFERENCES WITH THIS FEATURE. AS A RESULT...THE
CHANCE OF PRECIP/TS WAS LIMITED TO SLIGHT CHANCE. THE 23/00Z GFS
DOES SHOW AROUND A QUARTER OF AN INCH OF LIQUID CENTRAL DURING THE
AFTERNOON HOURS...WHILE THE OTHER MODELS ARE MUCH DRIER.
ALTHOUGH HIGH PRESSURE FROM CENTRAL CANADA WILL ATTEMPT TO SINK
ACROSS THE UPPER GREAT LAKES FOR SATURDAY...IT WILL BE PUSHED
EASTWARD...SKIMMING NORTHERN AND EASTERN UPPER MI SATURDAY INTO
SATURDAY NIGHT. MUCH OF THIS WILL BE DUE TO THE NEXT LOW DEVELOPING
OVER THE CENTRAL STATES. THE LOW WILL MOVE TO THE DAKOTAS/NE BY
SUNDAY AFTERNOON...WITH A WARM FRONT QUICKLY PUSHING UP ACROSS THE
CWA AND 850MB TEMPS JUMPING TO AROUND 18C SUNDAY NIGHT INTO MONDAY
MORNING.
THE 23/00Z GFS IS MORE PROGRESSIVE WITH THE SFC LOW...AVERAGING OUT
TO BE ABOUT 6 HOURS QUICKER THAN THE 23/00Z ECMWF FROM SATURDAY
NIGHT THROUGH EARLY MONDAY AFTERNOON. THE SLOW MOVING SYSTEM WILL
CONTINUE TO INFLUENCE OUR WEATHER THROUGH THE START OF THE NEXT WORK
WEEK...WITH A CHANCE OF SHOWERS LINGERING THROUGH MONDAY.
TEMPERATURES WILL EVENTUALLY COOL TUESDAY...BACK TO BELOW NORMAL
READINGS /MAINLY IN THE 50S TO MID 60S/.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 539 AM EDT WED MAY 23 2012
STRONG WINDS WILL BE THE MAIN CONCERN OVER THE NEXT 24 HOURS...OUT
OF A SOUTHERLY DIRECTION...AHEAD OF LOW PRESSURE STRETCHING FROM S
CENTRAL CANADA THROUGH THE CENTRAL PLAINS STATES. LLWS AT NIGHT WILL
BE LIKELY AT ALL 3 SITS...EVEN WITH IWD LIKELY KEEPING GUSTS AT OR
ABOVE 20KTS THROUGH THE OVERNIGHT HOURS. OTHERWISE...VFR CEILINGS
AND VIS SHOULD REMAIN...WITH ONLY A SMALL CHANCE OF SHOWERS AND/OR
THUNDERSTORMS GETTING TO IWD BY 12Z THURSDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 528 AM EDT WED MAY 23 2012
LOW PRESSURE OVER S MANITOBA WILL PUSH INTO ONTARIO TONIGHT AND
THURSDAY...AS AN ADDITIONAL LOW MOVES FROM THE CENTRAL PLAINS TO W
LS FRIDAY AFTERNOON. EXPECT THE LOW TO CONTINUE A NE TRACK ACROSS
ONTARIO THROUGH FRIDAY...WITH A TROUGH LINGERING ACROSS LAKE
SUPERIOR. STRENGTHENING S WINDS WILL BE THE RULE AHEAD OF THIS
SYSTEM TODAY THROUGH TOMORROW...STRONGEST ACROSS THE TALLER
OBSERVING PLATFORMS ACROSS CENTRAL LS.
HIGH PRESSURE OVER CENTRAL CANADA FRIDAY NIGHT WILL SLIDE ACROSS
ONTARIO SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. AS A
RESULT...A RIDGE WILL SLIDE ACROSS LS SATURDAY...WITH LIGHTER WINDS
TAKING HOLD. A LOW ACROSS THE CENTRAL PLAINS WILL FILL ACROSS MN
SUNDAY INTO SUNDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...KF
AVIATION...KF
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
529 AM EDT WED MAY 23 2012
.SYNOPSIS...
ISSUED AT 528 AM EDT WED MAY 23 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
THE GULF OF ALASKA INTO THE NW CONUS AND A FLAT DOWNSTREAM RIDGE
FROM THE SRN PLAINS TO THE UPPER MS VALLEY RESULTING IN WRLY FLOW
THROUGH THE NRN GREAT LAKES. AT THE SFC...A RIDGE EXTENDED FROM
JAMES BAY THROUGH ERN LAKE SUPERIOR AND LAKE MI INTO THE MID MS
VALLEY. SRLY WINDS WERE INCREASING FROM THE PLAINS INTO MN AHEAD OF
LOW PRES OVER THE WRN DAKOTAS. RADAR AND SFC OBS INDICATED AN AREA
OF MAINLY VIRGA/-SHRA/SPRINKLES OVER WRN UPPER MI SUPPORTED BY
305K-310K ISENTROPIC LIFT.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 528 AM EDT WED MAY 23 2012
TONIGHT...EXPECT THAT THE -SHRA/SPRINKLES WILL CONTINUE TO DIMINISH
AS THEY MOVE TO THE EAST LATE THIS AFTERNOON AND EVENING. WITH THE
INCREASED CLOUD COVER AND SOUTHERLY WINDS TONIGHT...TEMPS WILL ONLY
DROP OFF INTO THE MID 40S INLAND AND LOWER TO MID 50S FOR DOWNSLOPE
LOCATIONS OVER THE WEST HALF.
WEDNESDAY...AS THE HIGH OVER THE LAKE AND THE PLAINS TROUGH SHIFTS
TO THE EAST...THE GRADIENT WILL INCREASE ACROSS UPPER MICHIGAN.
THE MODELS WERE IN GOOD AGREEMENT IN KEEPING THE MOISTURE/LIFT AHEAD
OF THE MID LEVEL AND SFC TROUGH TO THE WEST...GRADUALLY SHIFTING
INTO WRN LAKE SUPERIOR LATE. WITH THE WAA AND SUNSHINE...TEMPS
SHOULD CLIMB INTO THE MID AND UPPER 70S INLAND WITH COOLER READINGS
NEAR LAKE MICHIGAN. MIXING SHOULD ALSO ALSO A DECENT PORTION OF THE
25-30 KT SRLY 925 MB WINDS TO MIX TO THE SFC. INCREASED WILDFIRE
DANGER IS EXPECTED WITH THE COMBINATION OF 15 TO 20 MPH SFC WINDS
AND GUSTS TO 30 MPH ALONG WITH RH VALUES DROPPING TO AROUND 30
PERCENT.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 528 AM EDT WED MAY 23 2012
WENT WARMER /ABOUT 5F/ AND WINDIER FOR FRIDAY. WHILE MUCH OF THE
WARMER AIR AND PRECIP WILL EXIT EAST WITH THE COLD FRONT EXITING
EAST IN THE MORNING...THE SFC TROUGH WILL LINGER OVERHEAD WITH WSW
WINDS AT THE SFC. EXPECT 850MB TEMPS TO FALL FROM THE MID TEENS C TO
AROUND 10C AROUND DAYBREAK FRIDAY...AND REMAIN STEADY AROUND THIS
LEVEL THROUGH SATURDAY. COULD NOT GET RID OF PRECIPITATION ALL
TOGETHER FOR...GIVEN 120KT 250MB JET STREAMING ACROSS UPPER
MICHIGAN...AND A KICKER OF A SHORTWAVE ALOFT. THERE IS SIGNIFICANT
TIMING/STRENGTH DIFFERENCES WITH THIS FEATURE. AS A RESULT...THE
CHANCE OF PRECIP/TS WAS LIMITED TO SLIGHT CHANCE. THE 23/00Z GFS
DOES SHOW AROUND A QUARTER OF AN INCH OF LIQUID CENTRAL DURING THE
AFTERNOON HOURS...WHILE THE OTHER MODELS ARE MUCH DRIER.
ALTHOUGH HIGH PRESSURE FROM CENTRAL CANADA WILL ATTEMPT TO SINK
ACROSS THE UPPER GREAT LAKES FOR SATURDAY...IT WILL BE PUSHED
EASTWARD...SKIMMING NORTHERN AND EASTERN UPPER MI SATURDAY INTO
SATURDAY NIGHT. MUCH OF THIS WILL BE DUE TO THE NEXT LOW DEVELOPING
OVER THE CENTRAL STATES. THE LOW WILL MOVE TO THE DAKOTAS/NE BY
SUNDAY AFTERNOON...WITH A WARM FRONT QUICKLY PUSHING UP ACROSS THE
CWA AND 850MB TEMPS JUMPING TO AROUND 18C SUNDAY NIGHT INTO MONDAY
MORNING.
THE 23/00Z GFS IS MORE PROGRESSIVE WITH THE SFC LOW...AVERAGING OUT
TO BE ABOUT 6 HOURS QUICKER THAN THE 23/00Z ECMWF FROM SATURDAY
NIGHT THROUGH EARLY MONDAY AFTERNOON. THE SLOW MOVING SYSTEM WILL
CONTINUE TO INFLUENCE OUR WEATHER THROUGH THE START OF THE NEXT WORK
WEEK...WITH A CHANCE OF SHOWERS LINGERING THROUGH MONDAY.
TEMPERATURES WILL EVENTUALLY COOL TUESDAY...BACK TO BELOW NORMAL
READINGS /MAINLY IN THE 50S TO MID 60S/.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 712 PM EDT TUE MAY 22 2012
WARM ADVECTION MID CLOUDS SHOULD GRADUALLY LIFT NORTH LATE TONIGHT
WITH THE MVMT OF A WARM FRONT NORTH INTO CANADA. EXPECT VFR
CONDITIONS TO PREVAIL WITH PLENTY OF LLVL DRY AIR THROUGH THE FCST
PD. TNGT...EXPECT LLWS AT BOTH KIWD AND KCMX UNDER A TIGHTENING SRLY
PRES GRADIENT AHEAD OF LOW PRES SYSTEM OVER THE NORTHERN PLAINS.
DAYTIME HEATING AND MIXING WILL ALLOW FOR STRONGER SRLY WINDS TO
REACH THE SFC...GUSTING AOA 25 AT BOTH KIWD AND KSAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 528 AM EDT WED MAY 23 2012
LOW PRESSURE OVER S MANITOBA WILL PUSH INTO ONTARIO TONIGHT AND
THURSDAY...AS AN ADDITIONAL LOW MOVES FROM THE CENTRAL PLAINS TO W
LS FRIDAY AFTERNOON. EXPECT THE LOW TO CONTINUE A NE TRACK ACROSS
ONTARIO THROUGH FRIDAY...WITH A TROUGH LINGERING ACROSS LAKE
SUPERIOR. STRENGTHENING S WINDS WILL BE THE RULE AHEAD OF THIS
SYSTEM TODAY THROUGH TOMORROW...STRONGEST ACROSS THE TALLER
OBSERVING PLATFORMS ACROSS CENTRAL LS.
HIGH PRESSURE OVER CENTRAL CANADA FRIDAY NIGHT WILL SLIDE ACROSS
ONTARIO SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. AS A
RESULT...A RIDGE WILL SLIDE ACROSS LS SATURDAY...WITH LIGHTER WINDS
TAKING HOLD. A LOW ACROSS THE CENTRAL PLAINS WILL FILL ACROSS MN
SUNDAY INTO SUNDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...KF
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
419 PM CDT WED MAY 23 2012
.UPDATE...SENT AN UPDATE TO THE FORECAST TO INCLUDE SEVERE
THUNDERSTORM WATCH 293 FOR PORTIONS OF THE FORECAST AREA THROUGH
11 PM CDT. THE GREATEST POTENTIAL FOR ANY SEVERE STORMS WILL
REMAIN WITH AND ALONG EITHER SIDE OF A SLOWLY PROGRESSING COLD
FRONT...WITH LARGE HAIL AND DAMAGING WIND GUSTS BEING THE PRIMARY
CONCERNS WITH ANY STORMS THAT DO DEVELOP.
&&
.PREV DISCUSSION... /ISSUED 400 PM CDT WED MAY 23 2012/
SHORT TERM...A FAIRLY ACTIVE START TO THE FORECAST IS EXPECTED
THIS EVENING AS A COLD FRONT SLOWLY MAKES ITS WAY ACROSS SOUTH
CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS...WITH AN ASSOCIATED MID
LEVEL LOW PRESSURE SYSTEM TO THE WEST EXPECTED TO HELP BRING SOME
WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY ACROSS MUCH OF THE
FORECAST AREA DURING THE OVERNIGHT HOURS TONIGHT.
SHORT TERM MODELS ARE IN MODERATE DISAGREEMENT WITH INITIATION OF
CONVECTION ALONG A PASSING COLD FRONT...CURRENTLY DRAPED FROM NEAR
NORFOLK...ACROSS GRAND ISLAND...SOUTH WESTWARD TOWARDS HOLDREGE.
THIS FRONT HAS BEEN VERY SLOW TO WORK ITS WAY ACROSS THE FORECAST
AREA THIS AFTERNOON...AND SO FAR HAS YET TO PRODUCE ENOUGH FORCING
TO BREAK LOW LEVEL CAP. 12Z NAM AND WRF BOTH DID TRY AND INITIATE
CONVECTION...BUT 18Z NAM AND LATEST HRRR BOTH HOLD OFF ANY
WIDESPREAD SHOWER OR THUNDERSTORM ACTIVITY TILL FORCING FROM MID
LEVEL LOW TO OUR WEST APPROACHES CENTRAL NEBRASKA AROUND MIDNIGHT.
THAT BEING SAID...INGREDIENTS ARE IN PLACE...AS LATEST MESO
ANALYSIS SHOWS A FINGER OF 2000+ J/KG OF CAPE ACROSS THE LOCAL
AREA NEAR THE SLOWLY PROGRESSING FRONT...AND LITTLE INHIBITION AS
WELL AS DEVELOPING CU FIELD IN SATELLITE. PER CONSENSUS AMONG
MODELS...DID BACK OFF ON INITIATION OF CONVECTION THIS
AFTERNOON...BUT INSERTED MENTION OF SEVERE STORMS AFTER 00Z...AS
COMBINATION OF SHEAR AND INSTABILITY SHOULD BE SUFFICIENT FOR SOME
SUPERCELLS TO DEVELOP IF INITIATION CAN BE REALIZED NEAR THE
FRONT.
BEHIND THE FRONT...AS THE MID LEVEL SHORTWAVE APPROACHES THE
REGION...BROADER SCALE FORCING SHOULD BE AMPLE ENOUGH TO DEVELOP
WIDESPREAD CONVECTION ACROSS THE LOCAL AREA BY AROUND
MIDNIGHT...CONTINUING INTO THE OVERNIGHT HOURS...SO THE POTENTIAL
FOR SEVERE HAIL AND STRONG WINDS REMAIN A CONCERN.
THEREAFTER...THE ATMOSPHERE SHOULD BEGIN TO STABILIZE BEHIND THE
DEPARTING MID LEVEL WAVE...WITH A SMALL CHANCE FOR SHOWERS AND AN
ISOLATED THUNDERSTORM CONTINUING INTO THE AFTERNOON HOURS WITH
NEAR TO SLIGHTLY BELOW SEASONAL TEMPERATURES EXPECTED DURING THE
AFTERNOON.
LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST
CONCERNS WILL BE CHANCES FOR THUNDERSTORMS THROUGH MOST OF THE
PERIOD AND TEMPERATURES.
ZONAL TO SOUTHWEST FLOW GIVES WAY TO NORTHWEST FLOW. THERE ARE
SEVERAL WAVES THAT MOVE THROUGH THE AREA DURING THE PERIOD. THE
FIRST WAVE MOVES INTO THE AREA THURSDAY NIGHT INTO FRIDAY. THERE
WILL BE A CHANCE FOR SOME THUNDERSTORMS. ON FRIDAY A SURFACE LOW
DEVELOPING IN KANSAS WILL LIFT A WARM FRONT NORTH INTO THE FORECAST
AREA. WITH THE FRONT MOVING THROUGH AND THE ANOTHER UPPER WAVE
MOVING INTO THE AREA THERE IS A BETTER CHANCE FOR THUNDERSTORMS.
SOME OF THESE STORMS COULD BE STRONG TO SEVERE.
SATURDAY AND SATURDAY NIGHT THERE ARE WEAK WAVES THAT MOVES THROUGH
BUT LITTLE IN THE WAY TO GET THINGS STARTED SO ANY PRECIPITATION
WILL BE SPOTTY. THE NEXT CHANCE FOR SOME THUNDERSTORMS WILL BE
SUNDAY INTO SUNDAY NIGHT. ANOTHER STRONGER WAVE MOVES INTO THE AREA
AND A COLD FRONT MOVES THROUGH THE AREA SUNDAY AFTERNOON AND
EVENING. THUNDERSTORMS WILL DEVELOP ALONG THE FRONT AS IT MOVES
THROUGH. SOME OF THESE COULD BE SEVERE.
MONDAY AND MONDAY NIGHT THE UPPER WAVE MOVES TO THE EAST AND A
SURFACE HIGH PRESSURE MOVES INTO THE AREA...KEEPING THINGS DRY.
AGAIN TUESDAY INTO TUESDAY NIGHT THERE ARE A FEW WEAK UPPER LEVEL
WAVES THAT MOVE INTO THE PLAINS. MODELS HAVE SOME FAIRLY SPOTTY
PRECIPITATION AROUND THE AREA WITH THESE UPPER LEVEL WAVES. THE GFS
HAS MORE PRECIPITATION AROUND THAN THE ECMWF DOES.
TEMPERATURES WILL BE SOMEWHAT VARIABLE THROUGH THE WEEK. WITH CLOUDS
AROUND ON FRIDAY THE TEMPERATURES WILL BE A BIT COOLER...WARMING
AFTER THE WARM FRONT LIFTS TO THE NORTH FOR SATURDAY AND SUNDAY THEN
COOLING AGAIN AS THE COOL FRONT MOVE THROUGH MONDAY AND TUESDAY AND
COOLING MORE AFTER THE FRONT MOVES THROUGH TUESDAY.
PREV DISCUSSION... /ISSUED 106 PM CDT WED MAY 23 2012/
AVIATION...18Z KGRI TAF...GUSTY SOUTHERLY WINDS AND VFR
CONDITIONS WILL CONTINUE AT KGRI FOR THE NEXT FEW HOURS AS A COLD
FRONT APPROACHES THE TERMINAL FROM THE NORTHWEST. THIS FRONT IS
MAKING VERY SLOW PROGRESS TOWARDS THE SOUTHEAST...PRESENTLY
STRETCHING FROM NEAR ORD TO LEXINGTON. WITH THE SLOW PROGRESSION
OF THIS FRONT...HELD OFF ON A WIND SHIFT AT THE TERMINAL UNTIL
23/21Z...WITH GUSTY NORTHERLY WINDS AND A FEW SHOWERS EXPECTED
THEREAFTER. AFT 24/00Z...EXPECT CIGS BEGIN TO LOWER TO NEAR MVFR
LEVELS...WITH AN INCREASING CHANCE FOR -SHRAS AND -TSRAS. BEST
FORCING FOR MORE PERSISTENT SHOWER AND THUNDERSTORM ACTIVITY IS
AROUND MIDNIGHT TONIGHT...AND INTRODUCED A TEMPO GROUP AROUND THIS
PERIOD FOR MORE PREVALENT MVFR CIGS AND VSBYS...BUT THAT
SAID...EXPECT AT LEAST SOME SHRAS AND TSRAS IN THE VICINITY OF THE
TERMINAL...SOME OF WHICH COULD CONTAIN LARGE HAIL AND SEVERE WIND
GUSTS...TO BE PRESENT FROM THE EVENING HOURS TONIGHT THROUGH THE
MORNING HOURS THURSDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION/UPDATE...ROSSI
LONG TERM...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
400 PM CDT WED MAY 23 2012
.SHORT TERM...A FAIRLY ACTIVE START TO THE FORECAST IS EXPECTED
THIS EVENING AS A COLD FRONT SLOWLY MAKES ITS WAY ACROSS SOUTH
CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS...WITH AN ASSOCIATED MID
LEVEL LOW PRESSURE SYSTEM TO THE WEST EXPECTED TO HELP BRING SOME
WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY ACROSS MUCH OF THE
FORECAST AREA DURING THE OVERNIGHT HOURS TONIGHT.
SHORT TERM MODELS ARE IN MODERATE DISAGREEMENT WITH INITIATION OF
CONVECTION ALONG A PASSING COLD FRONT...CURRENTLY DRAPED FROM NEAR
NORFOLK...ACROSS GRAND ISLAND...SOUTH WESTWARD TOWARDS HOLDREGE.
THIS FRONT HAS BEEN VERY SLOW TO WORK ITS WAY ACROSS THE FORECAST
AREA THIS AFTERNOON...AND SO FAR HAS YET TO PRODUCE ENOUGH FORCING
TO BREAK LOW LEVEL CAP. 12Z NAM AND WRF BOTH DID TRY AND INITIATE
CONVECTION...BUT 18Z NAM AND LATEST HRRR BOTH HOLD OFF ANY
WIDESPREAD SHOWER OR THUNDERSTORM ACTIVITY TILL FORCING FROM MID
LEVEL LOW TO OUR WEST APPROACHES CENTRAL NEBRASKA AROUND MIDNIGHT.
THAT BEING SAID...INGREDIENTS ARE IN PLACE...AS LATEST MESO
ANALYSIS SHOWS A FINGER OF 2000+ J/KG OF CAPE ACROSS THE LOCAL
AREA NEAR THE SLOWLY PROGRESSING FRONT...AND LITTLE INHIBITION AS
WELL AS DEVELOPING CU FIELD IN SATELLITE. PER CONSENSUS AMONG
MODELS...DID BACK OFF ON INITIATION OF CONVECTION THIS
AFTERNOON...BUT INSERTED MENTION OF SEVERE STORMS AFTER 00Z...AS
COMBINATION OF SHEAR AND INSTABILITY SHOULD BE SUFFICIENT FOR SOME
SUPERCELLS TO DEVELOP IF INITIATION CAN BE REALIZED NEAR THE
FRONT.
BEHIND THE FRONT...AS THE MID LEVEL SHORTWAVE APPROACHES THE
REGION...BROADER SCALE FORCING SHOULD BE AMPLE ENOUGH TO DEVELOP
WIDESPREAD CONVECTION ACROSS THE LOCAL AREA BY AROUND
MIDNIGHT...CONTINUING INTO THE OVERNIGHT HOURS...SO THE POTENTIAL
FOR SEVERE HAIL AND STRONG WINDS REMAIN A CONCERN.
THEREAFTER...THE ATMOSPHERE SHOULD BEGIN TO STABILIZE BEHIND THE
DEPARTING MID LEVEL WAVE...WITH A SMALL CHANCE FOR SHOWERS AND AN
ISOLATED THUNDERSTORM CONTINUING INTO THE AFTERNOON HOURS WITH
NEAR TO SLIGHTLY BELOW SEASONAL TEMPERATURES EXPECTED DURING THE
AFTERNOON.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST
CONCERNS WILL BE CHANCES FOR THUNDERSTORMS THROUGH MOST OF THE
PERIOD AND TEMPERATURES.
ZONAL TO SOUTHWEST FLOW GIVES WAY TO NORTHWEST FLOW. THERE ARE
SEVERAL WAVES THAT MOVE THROUGH THE AREA DURING THE PERIOD. THE
FIRST WAVE MOVES INTO THE AREA THURSDAY NIGHT INTO FRIDAY. THERE
WILL BE A CHANCE FOR SOME THUNDERSTORMS. ON FRIDAY A SURFACE LOW
DEVELOPING IN KANSAS WILL LIFT A WARM FRONT NORTH INTO THE FORECAST
AREA. WITH THE FRONT MOVING THROUGH AND THE ANOTHER UPPER WAVE
MOVING INTO THE AREA THERE IS A BETTER CHANCE FOR THUNDERSTORMS.
SOME OF THESE STORMS COULD BE STRONG TO SEVERE.
SATURDAY AND SATURDAY NIGHT THERE ARE WEAK WAVES THAT MOVES THROUGH
BUT LITTLE IN THE WAY TO GET THINGS STARTED SO ANY PRECIPITATION
WILL BE SPOTTY. THE NEXT CHANCE FOR SOME THUNDERSTORMS WILL BE
SUNDAY INTO SUNDAY NIGHT. ANOTHER STRONGER WAVE MOVES INTO THE AREA
AND A COLD FRONT MOVES THROUGH THE AREA SUNDAY AFTERNOON AND
EVENING. THUNDERSTORMS WILL DEVELOP ALONG THE FRONT AS IT MOVES
THROUGH. SOME OF THESE COULD BE SEVERE.
MONDAY AND MONDAY NIGHT THE UPPER WAVE MOVES TO THE EAST AND A
SURFACE HIGH PRESSURE MOVES INTO THE AREA...KEEPING THINGS DRY.
AGAIN TUESDAY INTO TUESDAY NIGHT THERE ARE A FEW WEAK UPPER LEVEL
WAVES THAT MOVE INTO THE PLAINS. MODELS HAVE SOME FAIRLY SPOTTY
PRECIPITATION AROUND THE AREA WITH THESE UPPER LEVEL WAVES. THE GFS
HAS MORE PRECIPITATION AROUND THAN THE ECMWF DOES.
TEMPERATURES WILL BE SOMEWHAT VARIABLE THROUGH THE WEEK. WITH CLOUDS
AROUND ON FRIDAY THE TEMPERATURES WILL BE A BIT COOLER...WARMING
AFTER THE WARM FRONT LIFTS TO THE NORTH FOR SATURDAY AND SUNDAY THEN
COOLING AGAIN AS THE COOL FRONT MOVE THROUGH MONDAY AND TUESDAY AND
COOLING MORE AFTER THE FRONT MOVES THROUGH TUESDAY.
&&
.PREV DISCUSSION... /ISSUED 106 PM CDT WED MAY 23 2012/
AVIATION...18Z KGRI TAF...GUSTY SOUTHERLY WINDS AND VFR
CONDITIONS WILL CONTINUE AT KGRI FOR THE NEXT FEW HOURS AS A COLD
FRONT APPROACHES THE TERMINAL FROM THE NORTHWEST. THIS FRONT IS
MAKING VERY SLOW PROGRESS TOWARDS THE SOUTHEAST...PRESENTLY
STRETCHING FROM NEAR ORD TO LEXINGTON. WITH THE SLOW PROGRESSION
OF THIS FRONT...HELD OFF ON A WIND SHIFT AT THE TERMINAL UNTIL
23/21Z...WITH GUSTY NORTHERLY WINDS AND A FEW SHOWERS EXPECTED
THEREAFTER. AFT 24/00Z...EXPECT CIGS BEGIN TO LOWER TO NEAR MVFR
LEVELS...WITH AN INCREASING CHANCE FOR -SHRAS AND -TSRAS. BEST
FORCING FOR MORE PERSISTENT SHOWER AND THUNDERSTORM ACTIVITY IS
AROUND MIDNIGHT TONIGHT...AND INTRODUCED A TEMPO GROUP AROUND THIS
PERIOD FOR MORE PREVALENT MVFR CIGS AND VSBYS...BUT THAT
SAID...EXPECT AT LEAST SOME SHRAS AND TSRAS IN THE VICINITY OF THE
TERMINAL...SOME OF WHICH COULD CONTAIN LARGE HAIL AND SEVERE WIND
GUSTS...TO BE PRESENT FROM THE EVENING HOURS TONIGHT THROUGH THE
MORNING HOURS THURSDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...ROSSI
LONG TERM...JCB
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
757 PM EDT THU MAY 24 2012
.SYNOPSIS...
THE COMBINATION OF BUILDING RIDGE ALOFT AND WEAK SURFACE HIGH
PRESSURE WILL RESULT IN PARTLY CLOUDY SKIES TONIGHT WITH SOME AREAS
OF PATCHY FOG. ON FRIDAY...SCATTERED SHOWERS AND THUNDERSTORMS WILL
DEVELOP ACROSS THE SAINT LAWRENCE VALLEY IN THE LATE AFTERNOON
HOURS AND SPREAD EAST INTO VERMONT DURING THE EVENING. SOME STORMS
COULD BE STRONG WITH GUSTY WINDS...SMALL HAIL...AND BRIEF HEAVY
DOWNPOURS....ESPECIALLY ACROSS NORTHERN NEW YORK. SLIGHTLY COOLER
AND DRIER AIR ARRIVES FOR SATURDAY INTO SUNDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 736 PM EDT THURSDAY...SOME MINOR ADJUSTMENTS WERE NECESSARY
FOR THIS UPDATE. ADJUSTED TEMPERATURES UP TO MATCH CURRENT
OBSERVATIONS AND TRENDED THEM FORWARD ALONG THE SAME TEMPERATURE
CURVE AS THE PREVIOUS FORECAST. CLOUD COVER ALONG THE SOUTHERN
CONNECTICUT RIVER VALLEY MAY INSULATE TEMPERATURES CAUSING WARMER
LOWS THAN CURRENTLY IN THE GRIDS...WILL REEVALUATE FOR THE NEXT
UPDATE. SHOWER ACTIVITY HAS INCREASED ALONG THE SOUTHERN CHAMPLAIN
VALLEY AND HAVE ADJUSTED POPS UP TO CONTINUE SLIGHT CHANCE FOR A
COUPLE OF HOURS TO AROUND 01-02Z. ALSO...RAINS NEAR SPRINGFIELD
HAVE INCREASED THE LIKELIHOOD OF FOG/MIST OVERNIGHT...INCREASED
DEWPOINTS IN THE LOWER CONNECTICUT RIVER VALLEY AND INCREASED
DURATION OF PATCHY FOG OVERNIGHT.
FRIDAY...INCREASED WINDS IN THE CHAMPLAIN AND SAINT LAWRENCE RIVER
VALLEYS INTO THE MID TWENTIES THROUGH THE AFTERNOON. GUIDANCE IS
SHOWING THAT WIND SPEEDS WILL BE HIGHER THAN PREVIOUSLY FORECASTED
PRIMARILY DUE TO A TIGHTER GRADIENT AHEAD OF THE APPROACHING
FRONTAL BOUNDARY...BOUNDARY LAYER MIXING TO NEARLY 850MB...AND
VALLEY CONVERGENCE INFLUENCE ON THE WINDS
.PREVIOUS DISCUSSION...FCST FOCUS WL BE AREAL COVERAGE OF
CLOUDS/FOG AGAIN TONIGHT...FOLLOWED BY CHCS FOR CONVECTION LATE
FRIDAY. WATER VAPOR SHOWS LARGE AREA OF SUBSIDENCE ACRS OUR CWA
THIS AFTN ASSOCIATED WITH BUILDING MID/UPPER LVL RIDGE.
MEANWHILE...MID/UPPER LVL TROF AND S/W ENERGY IS COMBINING WITH A
SFC COLD FRNT TO PRODUCE AREAS OF CONVECTION UPSTREAM ACRS THE
NORTHERN PLAINS/WESTERN GREAT LAKES. THIS ENERGY/MOISTURE AND SFC
BOUNDARY WL BE APPROACHING OUR WESTERN FA BTWN 18Z-21Z
FRIDAY...WITH INCREASING CHCS FOR STORMS. RAP AND LOCAL 4KM
SOUNDINGS ONCE AGAIN SHOW PLENTY OF SFC TO 850MB RH DEVELOPING
LATE THIS EVENING ACRS CENTRAL/EASTERN VT ASSOCIATED WITH MOIST SE
FLW. THIS WL CREATE AREAS OF LOW CLOUDS AND MIST...NOT THINKING AS
MUCH FOG TONIGHT...DUE TO BL WINDS OF 8 TO 12 KNTS. ALSO...AREAS
ACRS CENTRAL/EASTERN VT AND NORTHERN DACKS THAT RECEIVE ISOLATED
RAIN THIS AFTN...WL HAVE A BETTER CHC FOR FOG TONIGHT.
OTHERWISE...BL STAYS MIXED OVERNIGHT ACRS THE CPV/SLV AND SFC
DWPTS IN THE U50S/L60S WL RESULT IN LOWS BTWN 60 AND 65F...WITH
MAINLY 50S IN THE COOLER MTN VALLEYS.
ON FRIDAY...POTENT S/W ENERGY AND SFC COLD FRNT WL APPROACH OUR
WESTERN CWA BTWN 18Z-21Z. LEFTOVER MORNING CLOUDS SHOULD DISSIPATE
BY 15Z...WITH SFC TEMPS WARMING INTO THE U70S TO M80S AHEAD OF
BOUNDARY. THIS WL CREATE AN AXIS OF INSTABILITY WITH CAPE VALUES
NEAR 1400 J/KG...LIS AROUND -3C...AND TT`S NEAR 50. IN ADDITION...0
TO 3KM AND 0 TO 6KM SHEAR INCREASES ACRS OUR WESTERN CWA ON FRIDAY
AFTN...AS JET ENERGY FROM MID/UPPER LVL TROF APPROACHES. BOTH THE
NAM/GFS SHOW 0 TO 3KM VALUES AROUND 30 KNTS AND 0 TO 6KM SHEAR
VALUES NEAR 40 KNOTS. HOWEVER...RIBBON OF DEEP LAYER MOISTURE WL BE
WEAKENING ACRS OUR CWA...AS SYSTEM ENCOUNTERS STRONG MID/UPPER LVL
RIDGE AND BEST ULVL DYNAMICS WL BE SHIFTING TWD HUDSON BAY...INSTEAD
OF DIGGING SE ACRS THE EASTERN GREAT LAKES. THESE FACTORS WL LIMIT
AREAL COVERAGE/INTENSITY OF CONVECTION...ALONG WITH TIMING OF SFC
BOUNDARY AFT 00Z FOR CPV/VT...WITH INSTABILITY PARAMETERS WEAKENING.
THE BEST CHC FOR A STRONG STORM OR TWO WL BE NORTHERN NEW YORK WITH
DIME SIZE HAIL AND WIND GUST TO 50 MPH POSSIBLE BTWN 18Z-22Z.
OTHERWISE...BROKEN LINE OF SHOWERS WITH EMBEDDED STORMS WL ENTER THE
CPV BY 00Z AND BE THRU VT BY 06Z SATURDAY. PROGGED 85H TEMPS NEAR
14C AND 925MB TEMPS AROUND 18C SUPPORT HIGHS BACK INTO THE M70S
MTNS/NEK TO L/M 80S WARMER VALLEYS. FINALLY...SOUNDINGS SHOW GUSTY
SOUTH TO SOUTHWEST WINDS BTWN 15 AND 25 MPH WITH GUSTS TO 30 MPH.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 400 PM EDT THURSDAY...SFC COLD FRNT SWEEPS ACRS OUR CWA ON FRIDAY
NIGHT...WHILE HIGH PRES BUILDS INTO OUR FA BY SATURDAY. LLVL CAA
WL DEVELOP BEHIND SFC BOUNDARY FRIDAY NIGHT INTO SATURDAY WITH
BEST RH PROFILES MOVING EAST OF OUR CWA BY 12Z SAT. THE
COMBINATION OF BL WINDS AND CAA WL LIMIT AREAL COVERAGE OF FOG/BR
ON SATURDAY MORNING...BUT FEEL A FEW OF THE SHELTERED VALLEYS WL
SEE SOME FOG. TEMPS WL COOL INTO THE 40S MTN VALLEYS TO M/U50S
CPV/SLV ON SAT MORNING. HIGH PRES AND SUBSIDENCE ALOFT WL RESULT
IN PLENTY OF SUN ON SATURDAY WITH SOME FAIR WX CUMULUS POSSIBLE
ACRS THE MTNS AS CONVECTIVE TEMPS ARE REACHED. PROGGED 85H TEMPS
COOL BTWN 6-8C ON SATURDAY...SUPPORTING HIGHS ONLY IN THE 60S MTNS
TO L/M70S VALLEYS. SATURDAY NIGHT...AREAS OF FOG WL BE
POSSIBLE...ALONG WITH SOME HIGH LVL DEBRIS CLOUDS ACRS NORTHERN NY
FROM UPSTREAM CONVECTION. WL KEEP FCST DRY WITH TEMPS COOLING BACK
INTO THE 40S MTNS TO M/U50S CPV/SLV. NORTHERLY WINDS SHOULD BECOME
LIGHT AND VARIABLE OVERNIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 350 PM EDT THURSDAY...GUIDANCE POINTS TO A RATHER ACTIVE
PERIOD OF WEATHER FOR LATE MEMORIAL DAY WEEKEND INTO TUESDAY. THE
POTENTIAL EXISTS FOR ONE OR SEVERAL ROUNDS OF SHOWERS OR
THUNDERSTORMS DURING THIS PERIOD...ACCOMPANIED BY ABOVE-AVERAGE
TEMPERATURES AND RATHER HUMID WEATHER. CONVECTIVE SCENARIO WILL
DEPEND ON THUNDERSTORMS FROM PREVIOUS DAYS...SO IT IS DIFFICULT TO
PINPOINT SPECIFICS AT THIS TIME. IT APPEARS THAT MONDAY AND/OR
TUESDAY OFFER THE BEST POTENTIAL FOR THUNDER AS SHOWALTER INDICES
DROP BELOW ZERO (ESPECIALLY ON MONDAY) WITH RATHER STRONG UPPER-
LEVEL FLOW ALOFT. REGARDING TEMPERATURES...850MB TEMPERATURES
STEADILY RISE FROM 12-13 C ON SUNDAY TO AROUND 14-16 C ON
TUESDAY...LEADING TO HIGHS RISING FROM THE UPPER 70S TO THE
LOWER/MID 80S WITH LOWS IN THE UPPER 50S TO THE LOWER/MID 60S.
TEMPERATURES ON MONDAY APPEAR PARTICULARLY TRICKY EAST OF THE
GREENS GIVEN FORECAST COOLER THICKNESSES THERE...SO HAVE KEPT
HIGHS IN THE MID 70S IN THE NORTHEAST KINGDOM ON MONDAY.
COLD FRONT LOOKS TO SWEEP ACROSS THE NORTH COUNTRY LATER
TUESDAY...BRINGING WITH IT NOTICEABLY COOLER AND DRIER WEATHER TO
THE REGION FOR WEDNESDAY INTO THE REMAINDER OF THE EXTENDED.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
THROUGH 00Z SATURDAY...CURRENTLY VFR ACROSS THE REGION. A FEW
SMALL SHOWERS IN SOUTHERN VERMONT, BUT THEY WILL BE GONE BY 01Z SO
THEY ARE NOT EVEN WORTH MENTION IN TAFS. FORECAST ISSUE WILL BE
THE DEVELOPMENT OF IFR CONDITIONS (LOW CEILINGS) GENERALLY AFTER
05Z. FEEL RATHER CONFIDENT WE`LL SEE IT HAPPEN ACROSS EASTERN
VERMONT (KMPV TERMINAL) AND EVEN INTO KRUT AND KSLK TERMINALS AS
WELL. GUIDANCE IS GIVING SOME MIXED SIGNALS, AND CONFIDENCE NOT
VERY HIGH, BUT THINK EVEN KBTV AND KPBG WIL SEE PERIODS OF
CEILINGS AROUND 1500FT LATER TONIGHT.
WHATEVER LOW CEILINGS WE DO GET SHOULD BREAK FAIRLY QUICKLY FRIDAY
MORNING, SO VFR AREA WIDE AFTER 14Z. SURFACE SOUTHERLY WINDS WILL
BECOME RATHER GUSTY, LIKELY TO THE 25-30KT RANGE, ESPECIALLY IN
THE CHAMPLAIN VALLEY.
WE MAY SEE A FEW SHOWERS ACROSS THE HIGHER TERRAIN MID-DAY,
PERHAPS IMPACTING KMPV, BUT CHANCES ARE SO LOW THAT ITS NOT
MENTIONED IN TAF.
ANTICIPATE A LINE OF THUNDERSTORMS TO MOVE INTO THE ST LAWRENCE
VALLEY ROUGHLY 21Z, REACHING THE CHAMPLAIN VALLEY ABOUT 00Z. GIVEN
SO MUCH UNCERTAINTY THIS FAR OUT IN SPECIFIC DETAILS, HAVE JUST
PUT IN A PLACE HOLDER OF SHRA FOR KMSS AND KSLK LATE IN THE
PERIOD. KEPT MENTION OUT OF KPBG AND KBTV AT THIS POINT SINCE ITS
AT THE END OF THE TAF PERIOD.
OUTLOOK 00Z SATURDAY THROUGH TUESDAY...
00Z SATURDAY-06Z SATURDAY...MVFR/IFR IN SHOWERS/TSRA BUT TRENDING
VFR
06Z SATURDAY - 12Z SUNDAY...VFR UNDER HIGH PRESSURE. POSSIBLE
EVENING FOG/MIST AT MPV/SLK WITH IFR CEILINGS/VISIBILITIES.
12Z SUNDAY - 12Z MONDAY...VFR DEGRADING TO MVFR IN
SHOWERS/POSSIBLE THUNDER LATER SUNDAY/SUNDAY NIGHT AS WARM FRONT
MOVES NORTHWARD.
12Z MONDAY - 00Z WEDNESDAY...VFR, THOUGH MVFR/IFR POSSIBLE WITH
SCATTERED THUNDERSTORMS.
&&
.MARINE...
LAKE WIND ADVISORY HAS BEEN CANCELLED FOR THIS AFTERNOON. EXPECT
ANOTHER ISSUANCE FRIDAY LATE MORNING WHEN WINDS INCREASE AS
BOUNDARY LAYER MIXING ALLOWS FASTER WINDS ALOFT TO REACH THE
SURFACE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...BOYD
SHORT TERM...TABER
LONG TERM...LOCONTO
AVIATION...NASH/LOCONTO
MARINE...BOYD
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
736 PM EDT THU MAY 24 2012
.SYNOPSIS...
THE COMBINATION OF BUILDING RIDGE ALOFT AND WEAK SURFACE HIGH
PRESSURE WILL RESULT IN PARTLY CLOUDY SKIES TONIGHT WITH SOME AREAS
OF PATCHY FOG. ON FRIDAY...SCATTERED SHOWERS AND THUNDERSTORMS WILL
DEVELOP ACROSS THE SAINT LAWRENCE VALLEY IN THE LATE AFTERNOON
HOURS AND SPREAD EAST INTO VERMONT DURING THE EVENING. SOME STORMS
COULD BE STRONG WITH GUSTY WINDS...SMALL HAIL...AND BRIEF HEAVY
DOWNPOURS....ESPECIALLY ACROSS NORTHERN NEW YORK. SLIGHTLY COOLER
AND DRIER AIR ARRIVES FOR SATURDAY INTO SUNDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 736 PM EDT THURSDAY...SOME MINOR ADJUSTMENTS WERE NECESSARY
FOR THIS UPDATE. ADJUSTED TEMPERATURES UP TO MATCH CURRENT
OBSERVATIONS AND TRENDED THEM FORWARD ALONG THE SAME TEMPERATURE
CURVE AS THE PREVIOUS FORECAST. CLOUD COVER ALONG THE SOUTHERN
CONNECTICUT RIVER VALLEY MAY INSULATE TEMPERATURES CAUSING WARMER
LOWS THAN CURRENTLY IN THE GRIDS...WILL REEVALUATE FOR THE NEXT
UPDATE. SHOWER ACTIVITY HAS INCREASED ALONG THE SOUTHERN CHAMPLAIN
VALLEY AND HAVE ADJUSTED POPS UP TO CONTINUE SLIGHT CHANCE FOR A
COUPLE OF HOURS TO AROUND 01-02Z. ALSO...RAINS NEAR SPRINGFIELD
HAVE INCREASED THE LIKELIHOOD OF FOG/MIST OVERNIGHT...INCREASED
DEWPOINTS IN THE LOWER CONNECTICUT RIVER VALLEY AND INCREASED
DURATION OF PATCHY FOG OVERNIGHT.
FRIDAY...INCREASED WINDS IN THE CHAMPLAIN AND SAINT LAWRENCE RIVER
VALLEYS INTO THE MID TWENTIES THROUGH THE AFTERNOON. GUIDANCE IS
SHOWING THAT WIND SPEEDS WILL BE HIGHER THAN PREVIOUSLY FORECASTED
PRIMARILY DUE TO A TIGHTER GRADIENT AHEAD OF THE APPROACHING
FRONTAL BOUNDARY...BOUNDARY LAYER MIXING TO NEARLY 850MB...AND
VALLEY CONVERGENCE INFLUENCE ON THE WINDS
.PREVIOUS DISCUSSION...FCST FOCUS WL BE AREAL COVERAGE OF
CLOUDS/FOG AGAIN TONIGHT...FOLLOWED BY CHCS FOR CONVECTION LATE
FRIDAY. WATER VAPOR SHOWS LARGE AREA OF SUBSIDENCE ACRS OUR CWA
THIS AFTN ASSOCIATED WITH BUILDING MID/UPPER LVL RIDGE.
MEANWHILE...MID/UPPER LVL TROF AND S/W ENERGY IS COMBINING WITH A
SFC COLD FRNT TO PRODUCE AREAS OF CONVECTION UPSTREAM ACRS THE
NORTHERN PLAINS/WESTERN GREAT LAKES. THIS ENERGY/MOISTURE AND SFC
BOUNDARY WL BE APPROACHING OUR WESTERN FA BTWN 18Z-21Z
FRIDAY...WITH INCREASING CHCS FOR STORMS. RAP AND LOCAL 4KM
SOUNDINGS ONCE AGAIN SHOW PLENTY OF SFC TO 850MB RH DEVELOPING
LATE THIS EVENING ACRS CENTRAL/EASTERN VT ASSOCIATED WITH MOIST SE
FLW. THIS WL CREATE AREAS OF LOW CLOUDS AND MIST...NOT THINKING AS
MUCH FOG TONIGHT...DUE TO BL WINDS OF 8 TO 12 KNTS. ALSO...AREAS
ACRS CENTRAL/EASTERN VT AND NORTHERN DACKS THAT RECEIVE ISOLATED
RAIN THIS AFTN...WL HAVE A BETTER CHC FOR FOG TONIGHT.
OTHERWISE...BL STAYS MIXED OVERNIGHT ACRS THE CPV/SLV AND SFC
DWPTS IN THE U50S/L60S WL RESULT IN LOWS BTWN 60 AND 65F...WITH
MAINLY 50S IN THE COOLER MTN VALLEYS.
ON FRIDAY...POTENT S/W ENERGY AND SFC COLD FRNT WL APPROACH OUR
WESTERN CWA BTWN 18Z-21Z. LEFTOVER MORNING CLOUDS SHOULD DISSIPATE
BY 15Z...WITH SFC TEMPS WARMING INTO THE U70S TO M80S AHEAD OF
BOUNDARY. THIS WL CREATE AN AXIS OF INSTABILITY WITH CAPE VALUES
NEAR 1400 J/KG...LIS AROUND -3C...AND TT`S NEAR 50. IN ADDITION...0
TO 3KM AND 0 TO 6KM SHEAR INCREASES ACRS OUR WESTERN CWA ON FRIDAY
AFTN...AS JET ENERGY FROM MID/UPPER LVL TROF APPROACHES. BOTH THE
NAM/GFS SHOW 0 TO 3KM VALUES AROUND 30 KNTS AND 0 TO 6KM SHEAR
VALUES NEAR 40 KNOTS. HOWEVER...RIBBON OF DEEP LAYER MOISTURE WL BE
WEAKENING ACRS OUR CWA...AS SYSTEM ENCOUNTERS STRONG MID/UPPER LVL
RIDGE AND BEST ULVL DYNAMICS WL BE SHIFTING TWD HUDSON BAY...INSTEAD
OF DIGGING SE ACRS THE EASTERN GREAT LAKES. THESE FACTORS WL LIMIT
AREAL COVERAGE/INTENSITY OF CONVECTION...ALONG WITH TIMING OF SFC
BOUNDARY AFT 00Z FOR CPV/VT...WITH INSTABILITY PARAMETERS WEAKENING.
THE BEST CHC FOR A STRONG STORM OR TWO WL BE NORTHERN NEW YORK WITH
DIME SIZE HAIL AND WIND GUST TO 50 MPH POSSIBLE BTWN 18Z-22Z.
OTHERWISE...BROKEN LINE OF SHOWERS WITH EMBEDDED STORMS WL ENTER THE
CPV BY 00Z AND BE THRU VT BY 06Z SATURDAY. PROGGED 85H TEMPS NEAR
14C AND 925MB TEMPS AROUND 18C SUPPORT HIGHS BACK INTO THE M70S
MTNS/NEK TO L/M 80S WARMER VALLEYS. FINALLY...SOUNDINGS SHOW GUSTY
SOUTH TO SOUTHWEST WINDS BTWN 15 AND 25 MPH WITH GUSTS TO 30 MPH.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 400 PM EDT THURSDAY...SFC COLD FRNT SWEEPS ACRS OUR CWA ON FRIDAY
NIGHT...WHILE HIGH PRES BUILDS INTO OUR FA BY SATURDAY. LLVL CAA
WL DEVELOP BEHIND SFC BOUNDARY FRIDAY NIGHT INTO SATURDAY WITH
BEST RH PROFILES MOVING EAST OF OUR CWA BY 12Z SAT. THE
COMBINATION OF BL WINDS AND CAA WL LIMIT AREAL COVERAGE OF FOG/BR
ON SATURDAY MORNING...BUT FEEL A FEW OF THE SHELTERED VALLEYS WL
SEE SOME FOG. TEMPS WL COOL INTO THE 40S MTN VALLEYS TO M/U50S
CPV/SLV ON SAT MORNING. HIGH PRES AND SUBSIDENCE ALOFT WL RESULT
IN PLENTY OF SUN ON SATURDAY WITH SOME FAIR WX CUMULUS POSSIBLE
ACRS THE MTNS AS CONVECTIVE TEMPS ARE REACHED. PROGGED 85H TEMPS
COOL BTWN 6-8C ON SATURDAY...SUPPORTING HIGHS ONLY IN THE 60S MTNS
TO L/M70S VALLEYS. SATURDAY NIGHT...AREAS OF FOG WL BE
POSSIBLE...ALONG WITH SOME HIGH LVL DEBRIS CLOUDS ACRS NORTHERN NY
FROM UPSTREAM CONVECTION. WL KEEP FCST DRY WITH TEMPS COOLING BACK
INTO THE 40S MTNS TO M/U50S CPV/SLV. NORTHERLY WINDS SHOULD BECOME
LIGHT AND VARIABLE OVERNIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 350 PM EDT THURSDAY...GUIDANCE POINTS TO A RATHER ACTIVE
PERIOD OF WEATHER FOR LATE MEMORIAL DAY WEEKEND INTO TUESDAY. THE
POTENTIAL EXISTS FOR ONE OR SEVERAL ROUNDS OF SHOWERS OR
THUNDERSTORMS DURING THIS PERIOD...ACCOMPANIED BY ABOVE-AVERAGE
TEMPERATURES AND RATHER HUMID WEATHER. CONVECTIVE SCENARIO WILL
DEPEND ON THUNDERSTORMS FROM PREVIOUS DAYS...SO IT IS DIFFICULT TO
PINPOINT SPECIFICS AT THIS TIME. IT APPEARS THAT MONDAY AND/OR
TUESDAY OFFER THE BEST POTENTIAL FOR THUNDER AS SHOWALTER INDICES
DROP BELOW ZERO (ESPECIALLY ON MONDAY) WITH RATHER STRONG UPPER-
LEVEL FLOW ALOFT. REGARDING TEMPERATURES...850MB TEMPERATURES
STEADILY RISE FROM 12-13 C ON SUNDAY TO AROUND 14-16 C ON
TUESDAY...LEADING TO HIGHS RISING FROM THE UPPER 70S TO THE
LOWER/MID 80S WITH LOWS IN THE UPPER 50S TO THE LOWER/MID 60S.
TEMPERATURES ON MONDAY APPEAR PARTICULARLY TRICKY EAST OF THE
GREENS GIVEN FORECAST COOLER THICKNESSES THERE...SO HAVE KEPT
HIGHS IN THE MID 70S IN THE NORTHEAST KINGDOM ON MONDAY.
COLD FRONT LOOKS TO SWEEP ACROSS THE NORTH COUNTRY LATER
TUESDAY...BRINGING WITH IT NOTICEABLY COOLER AND DRIER WEATHER TO
THE REGION FOR WEDNESDAY INTO THE REMAINDER OF THE EXTENDED.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
THROUGH 18Z FRIDAY...MOIST SOUTHEAST FLOW ALONG AND EAST OF THE
GREENS BROUGHT SOME LOWER MVFR CEILINGS AT MPV THIS
MORNING...THOUGH THESE HAVE BEGUN TO LIFT BY EARLY AFTERNOON.
CURRENT SKIES RANGE FROM BKN/OVC VFR ACROSS MPV TO FEW/SCT VFR FOR
THE REMAINDER OF THE TERMINALS. AFTERNOON MIXING IN THE PARTLY
CLOUDY SKIES HAS RESULTED IN SOUTHERLY GUSTS TO AROUND 20KTS THIS
AFTERNOON...AND THESE WILL CONTINUE THROUGH 23Z/00Z BEFORE
BOUNDARY LAYER STABILIZES. THERE COULD BE A STRAY SHOWER OR
PERHAPS A THUNDERSHOWER AT RUT THIS AFTERNOON WITH SOME
INSTABILITY IN PLACE BUT NOT MUCH OF A TRIGGER...SO LEFT OUT FOR
NOW. EXPECTING MAINLY VFR FOR TONIGHT THOUGH SOME 3SM BR WITH
ASSOCIATED MVFR/IFR CEILINGS AT MPV AND SLK. DESPITE FAIRLY LIGHT
WINDS TONIGHT THINK THAT THERE WILL BE ENOUGH TURBULENT MIXING TO
LIMIT FOG FORMATION...THOUGH MIST LOOKS POSSIBLE.
ANY LINGERING LOWER CEILINGS LIFT BY 12-14Z FRIDAY BRINGING VFR
CEILINGS AND AFTERNOON SOUTHERLY GUSTS TO AROUND 20KTS. SURFACE
TROUGH WILL APPROACH FROM THE WEST LATE IN THE TAF PERIOD...WHICH
MAY TRIGGER SOME SHOWERS OR THUNDERSTORMS. THIS WILL BE
MONITORED...THOUGH FEEL AT THIS TIME THAT ANY SHOWERS/STORMS WILL
HOLD OFF UNTIL AFTER 18Z FRIDAY.
OUTLOOK 18Z FRIDAY THROUGH MONDAY...
18Z FRIDAY - 06Z SATURDAY...VFR WITH PERIODS MVFR/IFR IN SCATTERED
SHOWERS/STORMS AS COLD FRONT TRAVERSES THE REGION.
06Z SATURDAY - 12Z SUNDAY...VFR UNDER HIGH PRESSURE. POSSIBLE
EVENING FOG/MIST AT MPV/SLK WITH IFR CEILINGS/VISIBILITIES.
12Z SUNDAY - 12Z MONDAY...VFR DEGRADING TO MVFR IN
SHOWERS/POSSIBLE THUNDER LATER SUNDAY/SUNDAY NIGHT AS WARM FRONT
MOVES NORTHWARD.
12Z MONDAY - 00Z TUESDAY...MAINLY VFR THOUGH CAN`T RULE OUT A
SHOWER OR THUNDERSTORM MONDAY AFTERNOON.
&&
.MARINE...
LAKE WIND ADVISORY HAS BEEN CANCELLED FOR THIS AFTERNOON. EXPECT
ANOTHER ISSUANCE FRIDAY LATE MORNING WHEN WINDS INCREASE AS
BOUNDARY LAYER MIXING ALLOWS FASTER WINDS ALOFT TO REACH THE
SURFACE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...BOYD/TABER
SHORT TERM...TABER
LONG TERM...LOCONTO
AVIATION...LOCONTO
MARINE...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
402 PM EDT WED MAY 23 2012
.SYNOPSIS...
OUTSIDE A STRAY AFTERNOON OR EARLY EVENING SHOWER OR STORM...MAINLY
DRY WEATHER IS EXPECTED THROUGH THURSDAY WITH WARM TEMPERATURES AND
MODEST HUMIDITY LEVELS. A WEAKENING COLD FRONT WILL PUSH THROUGH THE
AREA FRIDAY NIGHT INTO SATURDAY THOUGH AGAIN SHOWERY PRECIPITATION
WILL BE SCATTERED AT BEST. WARM TEMPERATURES CONTINUE INTO NEXT WEEK
WITH MORE ACTIVE WEATHER POSSIBLE AS SHOWERS AND THUNDERSTORMS WILL
BE MORE COMMON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 115 PM EDT WEDNESDAY...UPDATED TO CAPTURE LATEST CLOUD
TRENDS WITH SOME CLRING ACRS THE SLV AND PARTS OF THE CPV/CENTRAL
VT. ALSO...CONT WITH THE MENTION OF CHC POPS AND SCHC OF THUNDER
ACRS SOUTHERN VT ZNS THIS AFTN...AS RADAR SHOWS A FEW ISOLATED
RETURNS. WITH TEMPS IN THE MID 70S AND DWPTS NEAR 60F...SOME
INSTABILITY HAS DEVELOPED WITH SFC BASED CAPE VALUES NEAR 1000
J/KG ACRS SOUTHERN VT ZNS...SUPPORTING A SCHC FOR A RUMBLE OF
THUNDER. REST OF FCST IN GOOD SHAPE WITH HIGHS EXPECTED TO BE IN
THE U60S TO M70S.
SEVERAL MINOR UPDATES TO CRNT FCST...BASED ON VIS SATL PICS AND
CRNT OBS. VIS SATL PIC SHOWS SOME BREAKS ACRS THE HIGHER
ELEVATIONS OF THE DACKS AND SOME CLRING ACRS THE SLV. SOUNDINGS
SHOW SOLID RH PROFILES THRU 18Z...THEN SOME CLRING. WL USE VIS
SALT TOOL IN GFE TO CAPTURE CRNT TRENDS...THEN TAPER OVERALL AREAL
COVERAGE OF CLOUDS AFT 18Z THIS AFTN...BASED ON SOUNDING RH
PROFILES. OTHERWISE...HAVE DECREASED HRLY TEMPS THIS MORNING DUE
TO CLOUDS...BUT FEEL AS BREAKS DEVELOP THIS AFTN...TEMPS WL CLIMB
QUICKLY. REST OF FCST IN GREAT SHAPE.
MODEST ADJUSTMENTS TO SKY COVER TO KEEP MOSTLY CLOUDY CONDS ACROSS
MUCH OF THE AREA THROUGH THE MORNING HOURS BASED OFF CURRENT
OBSERVATIONAL/SATELLITE TRENDS AND LATEST RAP 925MB RH PROGS. ALSO
NUDGED MAX TEMPS DOWN JUST A TAD (1-2 DEG). REST OF FCST
UNCHANGED.
PRIOR DISCUSSION...
WEAK AND DISSOLVING FRONTAL SYSTEM CONTINUES TO SAG EVER SO
SLOWLY SOUTHWARD THROUGH THE FORECAST AREA THIS MORNING AS WINDS
HAVE SHIFTED TO LIGHT NORTH/NORTHEASTERLY ACROSS OUR NRN COUNTIES
AS OF 3 AM. STILL A FEW SHOWERS/PATCHY -DZ AROUND THE AREA WITH
NEAR SATURATED LOWER LEVELS. OTHERWISE A RATHER UNEVENTFUL DAY ON
TAP WEATHERWISE FOR THE REGION AS AFOREMENTIONED FRONTAL SYSTEM
DISSIPATES TO OUR IMMEDIATE SOUTH ACROSS CENTRAL/SRN NEW ENGLAND.
DESPITE LIGHT NORTHERLY FLOW...NO APPRECIABLE AIRMASS CHANGE
EXPECTED AND MUCH DRIER AIR OFF TO OUR NORTH ACROSS SRN ON/QE
REALLY WON`T MAKE APPRECIABLE INROADS INTO OUR AREA. VARIABLY
CLOUDY SKIES AND PATCHY BR/FG THIS MORNING SHOULD SCOUR OUT TO
PTLY SUNNY IN MANY AREAS THIS AFTERNOON AS PBL DEEPENS. STILL
COULD SEE AN ISOLD LATE AFTERNOON/EARLY EVENING SHOWER/STORM FAR
SOUTH IN CLOSER PROXIMITY TO OLD BOUNDARY AND DEEPER MOISTURE
AXIS...BUT DRY WEATHER WILL BE THE GENERAL RULE. BLENDED 18-00Z
MODEL 925 MB THERMAL PROGS SUPPORT BLENDED MOS LATE AFTERNOON
HIGHS IN THE 72 TO 78 DEGREE RANGE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
AS OF 344 AM EDT WEDNESDAY...THEN QUIET TONIGHT AS DEEP LAYER SFC
TO H5 RIDGING BEGINS TO BUILD BACK ACROSS THE REGION. MAINLY
CLR/PTLY CLOUDY SKIES EXPECTED...THOUGH AS FLOW TRENDS LIGHT
SOUTH/SOUTHEASTERLY OVERNIGHT A DECENT CHANCE THAT SOME LOWER
CLOUD COVER MAY BEGIN TO ENCROACH BACK NORTHWARD INTO OUR SRN/SERN
VT COUNTIES AFTER MIDNIGHT. PATCHY FOG ALSO A GOOD BET AS WET
GROUND CONDS FOSTER SATURATION IN THE NEAR-SFC LAYERS. LOWS
SIMILAR TO THIS MORNING...MAINLY 50S TO LOCALLY NEAR 60 IN MILDER
SPOTS OF THE CHAMPLAIN VALLEY.
BY THURSDAY RIDGING WILL BECOME WELL ESTABLISHED ACROSS THE AREA AS
SOUTHERLY FLOW SLOWLY INCREASES AND TRENDS MODESTLY GUSTY BY
AFTERNOON. STILL AN OUTSIDE CHANCE OF A FEW SHOWERS/STRAY STORMS
HERE AND THERE DURING PEAK HEATING HOURS SOUTH AS SFC INSOLATION
ACTS ON RESIDUAL MOISTURE AXIS...OTHERWISE DRY AND PTLY SUNNY
SHOULD BE THE RULE IN MOST LOCALES. TEMPERATURES A TAD WARMER INTO
THE 77 TO 83 RANGE...CONTINUING RECENT STRING OF ABOVE NORMAL DAYS.
THEN PTLY/MOSTLY CLOUDY AND MILD THURSDAY NIGHT AS TEMPERATURES HOLD
IN THE UPPER 50S TO LOWER 60S.
BY FRIDAY...GUSTY SOUTHERLY FLOW CONTINUES ACROSS THE AREA ALONG
WITH A CONTINUED ISOLD THREAT OF A FEW SHOWERS/STORMS HERE AND THERE
BY THE AFTERNOON/EARLY EVENING HOURS. BEST THREAT APPEARS TO OCCUR
ACROSS THE SLV WHERE ADDED MOISTURE CONVERGENCE AND APPROACHING
WEAK FRONTAL SYSTEM MAY AID IN SOMEWHAT HIGHER COVERAGE TOWARD
EVENING. CONTINUED UNSEASONABLY WARM WITH HIGHS 78 TO 85 AND MODEST
HUMIDITY LEVELS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 401 PM EDT WEDNESDAY...HOLIDAY WEEKEND LOOKS TO BE FAIRLY
QUIET AS FRONTAL BOUNDARY WILL BE STALLED OVER THE REGION
SEPARATING HIGH PRESSURE TO OUR NORTH AND SOUTH. LOOKING AT
GENERALLY DRY CONDITIONS UNDER PARTLY SUNNY SKIES WITH
TEMPERATURES GENERALLY ABOVE NORMAL...HIGHS IN THE 70S AND LOWS
IN THE UPPER 40S AND 50S. BOUNDARY BEGINS TO SHIFT NORTHWARD
SUNDAY NIGHT INTO MONDAY WITH TEMPS WARMING INTO THE MID TO UPPER
70S MONDAY AFTERNOON...AND DEWPOINTS RISING INTO THE MID 50S.
INDEED, BOTH THE ECMWF AND GFS INDICATE MODEST SHEAR AND
INSTABILITY ALONG AND SOUTH OF THE BOUNDARY MONDAY AFTERNOON.
TRICKY TO FORECAST BOUNDARY LOCATION OUT THIS FAR...BUT CERTAINLY
COULD SEE SOME STORMS FIRE ALONG IT BASED ON MODEL INSTABILITY.
LOW PRESSURE MOVING THROUGH SOUTHERN CANADA WILL PUSH THE
AFOREMENTIONED BOUNDARY NORTH OF THE REGION PUTTING THE NORTH
COUNTRY IN THE WARM SECTOR TUESDAY. ATTENDING COLD FRONT WILL
MOVE ACROSS THE REGION TUESDAY AFTERNOON/EVENING RENEWING THE
CHANCES FOR MORE SHOWERS AND THUNDERSTORMS.
A LOT OF UNCERTAINTY GOING INTO TUESDAY NIGHT AND WEDNESDAY AS
RELIABLE LONG TERM MODELS OF THE GFS AND ECMWF SHOW UPPER LEVEL
TROUGH OVER SOUTH CENTRAL CANADA CLOSING OFF AND SLOWLY DROPPING
SOUTHEASTWARD ACROSS THE REGION LATE IN THE WEEK. THIS WOULD
PROVIDE THE AREA WITH MARKEDLY COOLER TEMPERATURES AND CHANCES
FOR PRECIP...BUT CERTAINLY TOO FAR OUT TO NAIL DOWN ANY DETAILS
AT THIS POINT.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...TRICKY AVIATION FORECAST OVER THE NEXT 24
HOURS. FIRST CHALLENGE IS TIMING CLEARING OF LOW LEVEL CLOUDS
ACROSS THE REGION THIS AFTERNOON. MOST SITES BREAKING OUT INTO
MVFR CATEGORY AS OF 1730Z...AND EXPECT A GENERALLY LIFTING TO VFR
AT ALL SITES BY 21Z. THEREAFTER...CLEARING TREND CONTINUES THROUGH
MIDNIGHT BEFORE MOISTURE BEGINS TO SURGE NORTHWARD AGAIN FROM
THE SOUTH. LOW LEVEL MOISTURE WILL BE FAIRLY HIGH SHALLOW MUCH
LIKE THIS MORNING...BUT MODEL GUIDANCE INDICATES BOUNDARY LAYER
WINDS FROM THE SURFACE TO 1KFT WILL BE INCREASING THROUGH THE
NIGHT. THINKING THERE WON`T BE A LOT OF FOG AROUND...BUT RATHER A
LOW STRATUS DECK FORMING AT ALL SITES EXCEPT KMSS AFTER 06Z. HARD
TO REALLY NAIL DOWN THE DETAILS AT THIS POINT SO STAY TUNED TO
FURTHER TAF ISSUANCES. OTHERWISE...AFTER 13Z EXPECT ANY LOW CLOUDS
TO LIFT TO CUMULUS AT OR ABOVE MOUNTAIN TOP LEVELS WITH WINDS
PICKING UP OUT OF THE SOUTH.
OUTLOOK 18Z THURSDAY THROUGH MONDAY...
18Z THURSDAY THROUGH 18Z FRIDAY...GENERALLY VFR UNDER RIDGE OF
HIGH PRESSURE...WITH MORNING FOG/BR POSSIBLE.
18Z FRIDAY THROUGH SUNDAY...GENERALLY VFR WITH CHANCES FOR MVFR
IN SCATTERED SHOWERS/TSTORMS AS FRONTAL BOUNDARY STALLS OVER THE
REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/TABER
SHORT TERM...JMG
LONG TERM...LAHIFF
AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
138 PM EDT WED MAY 23 2012
.SYNOPSIS...
OUTSIDE A STRAY AFTERNOON OR EARLY EVENING SHOWER OR STORM...MAINLY
DRY WEATHER IS EXPECTED THROUGH THURSDAY WITH WARM TEMPERATURES AND
MODEST HUMIDITY LEVELS. A WEAKENING COLD FRONT WILL PUSH THROUGH THE
AREA FRIDAY NIGHT INTO SATURDAY THOUGH AGAIN SHOWERY PRECIPITATION
WILL BE SCATTERED AT BEST. WARM TEMPERATURES CONTINUE INTO NEXT WEEK
WITH MORE ACTIVE WEATHER POSSIBLE AS SHOWERS AND THUNDERSTORMS WILL
BE MORE COMMON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 115 PM EDT WEDNESDAY...UPDATED TO CAPTURE LATEST CLOUD
TRENDS WITH SOME CLRING ACRS THE SLV AND PARTS OF THE CPV/CENTRAL
VT. ALSO...CONT WITH THE MENTION OF CHC POPS AND SCHC OF THUNDER
ACRS SOUTHERN VT ZNS THIS AFTN...AS RADAR SHOWS A FEW ISOLATED
RETURNS. WITH TEMPS IN THE MID 70S AND DWPTS NEAR 60F...SOME
INSTABILITY HAS DEVELOPED WITH SFC BASED CAPE VALUES NEAR 1000
J/KG ACRS SOUTHERN VT ZNS...SUPPORTING A SCHC FOR A RUMBLE OF
THUNDER. REST OF FCST IN GOOD SHAPE WITH HIGHS EXPECTED TO BE IN
THE U60S TO M70S.
SEVERAL MINOR UPDATES TO CRNT FCST...BASED ON VIS SATL PICS AND
CRNT OBS. VIS SATL PIC SHOWS SOME BREAKS ACRS THE HIGHER
ELEVATIONS OF THE DACKS AND SOME CLRING ACRS THE SLV. SOUNDINGS
SHOW SOLID RH PROFILES THRU 18Z...THEN SOME CLRING. WL USE VIS
SALT TOOL IN GFE TO CAPTURE CRNT TRENDS...THEN TAPER OVERALL AREAL
COVERAGE OF CLOUDS AFT 18Z THIS AFTN...BASED ON SOUNDING RH
PROFILES. OTHERWISE...HAVE DECREASED HRLY TEMPS THIS MORNING DUE
TO CLOUDS...BUT FEEL AS BREAKS DEVELOP THIS AFTN...TEMPS WL CLIMB
QUICKLY. REST OF FCST IN GREAT SHAPE.
MODEST ADJUSTMENTS TO SKY COVER TO KEEP MOSTLY CLOUDY CONDS ACROSS
MUCH OF THE AREA THROUGH THE MORNING HOURS BASED OFF CURRENT
OBSERVATIONAL/SATELLITE TRENDS AND LATEST RAP 925MB RH PROGS. ALSO
NUDGED MAX TEMPS DOWN JUST A TAD (1-2 DEG). REST OF FCST
UNCHANGED.
PRIOR DISCUSSION...
WEAK AND DISSOLVING FRONTAL SYSTEM CONTINUES TO SAG EVER SO
SLOWLY SOUTHWARD THROUGH THE FORECAST AREA THIS MORNING AS WINDS
HAVE SHIFTED TO LIGHT NORTH/NORTHEASTERLY ACROSS OUR NRN COUNTIES
AS OF 3 AM. STILL A FEW SHOWERS/PATCHY -DZ AROUND THE AREA WITH
NEAR SATURATED LOWER LEVELS. OTHERWISE A RATHER UNEVENTFUL DAY ON
TAP WEATHERWISE FOR THE REGION AS AFOREMENTIONED FRONTAL SYSTEM
DISSIPATES TO OUR IMMEDIATE SOUTH ACROSS CENTRAL/SRN NEW ENGLAND.
DESPITE LIGHT NORTHERLY FLOW...NO APPRECIABLE AIRMASS CHANGE
EXPECTED AND MUCH DRIER AIR OFF TO OUR NORTH ACROSS SRN ON/QE
REALLY WON`T MAKE APPRECIABLE INROADS INTO OUR AREA. VARIABLY
CLOUDY SKIES AND PATCHY BR/FG THIS MORNING SHOULD SCOUR OUT TO
PTLY SUNNY IN MANY AREAS THIS AFTERNOON AS PBL DEEPENS. STILL
COULD SEE AN ISOLD LATE AFTERNOON/EARLY EVENING SHOWER/STORM FAR
SOUTH IN CLOSER PROXIMITY TO OLD BOUNDARY AND DEEPER MOISTURE
AXIS...BUT DRY WEATHER WILL BE THE GENERAL RULE. BLENDED 18-00Z
MODEL 925 MB THERMAL PROGS SUPPORT BLENDED MOS LATE AFTERNOON
HIGHS IN THE 72 TO 78 DEGREE RANGE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
AS OF 344 AM EDT WEDNESDAY...THEN QUIET TONIGHT AS DEEP LAYER SFC
TO H5 RIDGING BEGINS TO BUILD BACK ACROSS THE REGION. MAINLY
CLR/PTLY CLOUDY SKIES EXPECTED...THOUGH AS FLOW TRENDS LIGHT
SOUTH/SOUTHEASTERLY OVERNIGHT A DECENT CHANCE THAT SOME LOWER
CLOUD COVER MAY BEGIN TO ENCROACH BACK NORTHWARD INTO OUR SRN/SERN
VT COUNTIES AFTER MIDNIGHT. PATCHY FOG ALSO A GOOD BET AS WET
GROUND CONDS FOSTER SATURATION IN THE NEAR-SFC LAYERS. LOWS
SIMILAR TO THIS MORNING...MAINLY 50S TO LOCALLY NEAR 60 IN MILDER
SPOTS OF THE CHAMPLAIN VALLEY.
BY THURSDAY RIDGING WILL BECOME WELL ESTABLISHED ACROSS THE AREA AS
SOUTHERLY FLOW SLOWLY INCREASES AND TRENDS MODESTLY GUSTY BY
AFTERNOON. STILL AN OUTSIDE CHANCE OF A FEW SHOWERS/STRAY STORMS
HERE AND THERE DURING PEAK HEATING HOURS SOUTH AS SFC INSOLATION
ACTS ON RESIDUAL MOISTURE AXIS...OTHERWISE DRY AND PTLY SUNNY
SHOULD BE THE RULE IN MOST LOCALES. TEMPERATURES A TAD WARMER INTO
THE 77 TO 83 RANGE...CONTINUING RECENT STRING OF ABOVE NORMAL DAYS.
THEN PTLY/MOSTLY CLOUDY AND MILD THURSDAY NIGHT AS TEMPERATURES HOLD
IN THE UPPER 50S TO LOWER 60S.
BY FRIDAY...GUSTY SOUTHERLY FLOW CONTINUES ACROSS THE AREA ALONG
WITH A CONTINUED ISOLD THREAT OF A FEW SHOWERS/STORMS HERE AND THERE
BY THE AFTERNOON/EARLY EVENING HOURS. BEST THREAT APPEARS TO OCCUR
ACROSS THE SLV WHERE ADDED MOISTURE CONVERGENCE AND APPROACHING
WEAK FRONTAL SYSTEM MAY AID IN SOMEWHAT HIGHER COVERAGE TOWARD
EVENING. CONTINUED UNSEASONABLY WARM WITH HIGHS 78 TO 85 AND MODEST
HUMIDITY LEVELS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 445 AM EDT WEDNESDAY...THE PERIOD WILL START WITH A COLD
FRONT TRAVERSING OVER THE FCST AREA. 00Z GFS AND ECMWF DIFFER ON
TIMING OF FRONTAL PASSAGE...BUT BOTH MODELS SHOW FRONT LINGERING
ALONG THE ATLANTIC COAST BY SATURDAY NIGHT. HIGH PRESSURE WILL
THEN BUILD IN AT THE SFC FROM SOUTHERN QUEBEC...GIVING A SHORT
DRY PERIOD ON SATURDAY INTO EARLY SUNDAY. LATE SUNDAY...MODEL
GUIDANCE INDICATES AN UPPER LEVEL DISTURBANCE/WEAK SHORT WAVE
WILL MOVE OVER THE REGION...WITH AN UPPER LEVEL JET TO OUR NORTH.
INCREASED INSTABILITY LATE SUNDAY INTO MONDAY WITH GFS INDICATING
CAPE VALUES OVER 1000J/KG AND NEGATIVE LIFTED INDICES. ECMWF
KEEPS THE HIGH CAPE VALUE TO OUR SOUTH.
THE AFOREMENTIONED COLD FRONT WILL LIFT NORTHWARD AS A WARM FRONT
AS LOW PRESSURE CENTER AT THE SFC MOVES FROM THE NWRN GREAT LAKES
TO SE ONTARIO MONDAY AND TUESDAY. THIS WILL CONTINUE TO PRODUCE
CHANCE OF SHOWERS.
TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL...WITH A SLGT
COOLING TREND TO START. 850HPA TEMPS WILL COOL FROM THE MID TEENS
TO 10C-12C SUNDAY. ECMWF HAS FRONT SYSTEM BEING STRONGER THAN GFS
AND BRINGS SINGLE DIGIT TEMPS AT 850HPA BY MONDAY MORNING. BOTH
MODELS DO SHOW DECENT TEMP GRADIENT OVER THE NORTHEAST WHICH WILL
HELP WITH POTENTIAL FOR CONVECTIVE ACTIVITY. BOTH MODELS WARM
TEMPS ON MONDAY TO MID TO UPPER TEENS AT 850HPA...BUT GRADUALLY
COOLING ON TUESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...TRICKY AVIATION FORECAST OVER THE NEXT 24
HOURS. FIRST CHALLENGE IS TIMING CLEARING OF LOW LEVEL CLOUDS
ACROSS THE REGION THIS AFTERNOON. MOST SITES BREAKING OUT INTO
MVFR CATEGORY AS OF 1730Z...AND EXPECT A GENERALLY LIFTING TO VFR
AT ALL SITES BY 21Z. THEREAFTER...CLEARING TREND CONTINUES THROUGH
MIDNIGHT BEFORE MOISTURE BEGINS TO SURGE NORTHWARD AGAIN FROM
THE SOUTH. LOW LEVEL MOISTURE WILL BE FAIRLY HIGH SHALLOW MUCH
LIKE THIS MORNING...BUT MODEL GUIDANCE INDICATES BOUNDARY LAYER
WINDS FROM THE SURFACE TO 1KFT WILL BE INCREASING THROUGH THE
NIGHT. THINKING THERE WON`T BE A LOT OF FOG AROUND...BUT RATHER A
LOW STRATUS DECK FORMING AT ALL SITES EXCEPT KMSS AFTER 06Z. HARD
TO REALLY NAIL DOWN THE DETAILS AT THIS POINT SO STAY TUNED TO
FURTHER TAF ISSUANCES. OTHERWISE...AFTER 13Z EXPECT ANY LOW CLOUDS
TO LIFT TO CUMULUS AT OR ABOVE MOUNTAIN TOP LEVELS WITH WINDS
PICKING UP OUT OF THE SOUTH.
OUTLOOK 18Z THURSDAY THROUGH MONDAY...
18Z THURSDAY THROUGH 18Z FRIDAY...GENERALLY VFR UNDER RIDGE OF
HIGH PRESSURE...WITH MORNING FOG/BR POSSIBLE.
18Z FRIDAY THROUGH SUNDAY...GENERALLY VFR WITH CHANCES FOR MVFR
IN SCATTERED SHOWERS/TSTORMS AS FRONTAL BOUNDARY STALLS OVER THE
REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/TABER
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
122 PM EDT WED MAY 23 2012
.SYNOPSIS...
OUTSIDE A STRAY AFTERNOON OR EARLY EVENING SHOWER OR STORM...MAINLY
DRY WEATHER IS EXPECTED THROUGH THURSDAY WITH WARM TEMPERATURES AND
MODEST HUMIDITY LEVELS. A WEAKENING COLD FRONT WILL PUSH THROUGH THE
AREA FRIDAY NIGHT INTO SATURDAY THOUGH AGAIN SHOWERY PRECIPITATION
WILL BE SCATTERED AT BEST. WARM TEMPERATURES CONTINUE INTO NEXT WEEK
WITH MORE ACTIVE WEATHER POSSIBLE AS SHOWERS AND THUNDERSTORMS WILL
BE MORE COMMON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 115 PM EDT WEDNESDAY...UPDATED TO CAPTURE LATEST CLOUD
TRENDS WITH SOME CLRING ACRS THE SLV AND PARTS OF THE CPV/CENTRAL
VT. ALSO...CONT WITH THE MENTION OF CHC POPS AND SCHC OF THUNDER
ACRS SOUTHERN VT ZNS THIS AFTN...AS RADAR SHOWS A FEW ISOLATED
RETURNS. WITH TEMPS IN THE MID 70S AND DWPTS NEAR 60F...SOME
INSTABILITY HAS DEVELOPED WITH SFC BASED CAPE VALUES NEAR 1000
J/KG ACRS SOUTHERN VT ZNS...SUPPORTING A SCHC FOR A RUMBLE OF
THUNDER. REST OF FCST IN GOOD SHAPE WITH HIGHS EXPECTED TO BE IN
THE U60S TO M70S.
SEVERAL MINOR UPDATES TO CRNT FCST...BASED ON VIS SATL PICS AND
CRNT OBS. VIS SATL PIC SHOWS SOME BREAKS ACRS THE HIGHER
ELEVATIONS OF THE DACKS AND SOME CLRING ACRS THE SLV. SOUNDINGS
SHOW SOLID RH PROFILES THRU 18Z...THEN SOME CLRING. WL USE VIS
SALT TOOL IN GFE TO CAPTURE CRNT TRENDS...THEN TAPER OVERALL AREAL
COVERAGE OF CLOUDS AFT 18Z THIS AFTN...BASED ON SOUNDING RH
PROFILES. OTHERWISE...HAVE DECREASED HRLY TEMPS THIS MORNING DUE
TO CLOUDS...BUT FEEL AS BREAKS DEVELOP THIS AFTN...TEMPS WL CLIMB
QUICKLY. REST OF FCST IN GREAT SHAPE.
MODEST ADJUSTMENTS TO SKY COVER TO KEEP MOSTLY CLOUDY CONDS ACROSS
MUCH OF THE AREA THROUGH THE MORNING HOURS BASED OFF CURRENT
OBSERVATIONAL/SATELLITE TRENDS AND LATEST RAP 925MB RH PROGS. ALSO
NUDGED MAX TEMPS DOWN JUST A TAD (1-2 DEG). REST OF FCST
UNCHANGED.
PRIOR DISCUSSION...
WEAK AND DISSOLVING FRONTAL SYSTEM CONTINUES TO SAG EVER SO
SLOWLY SOUTHWARD THROUGH THE FORECAST AREA THIS MORNING AS WINDS
HAVE SHIFTED TO LIGHT NORTH/NORTHEASTERLY ACROSS OUR NRN COUNTIES
AS OF 3 AM. STILL A FEW SHOWERS/PATCHY -DZ AROUND THE AREA WITH
NEAR SATURATED LOWER LEVELS. OTHERWISE A RATHER UNEVENTFUL DAY ON
TAP WEATHERWISE FOR THE REGION AS AFOREMENTIONED FRONTAL SYSTEM
DISSIPATES TO OUR IMMEDIATE SOUTH ACROSS CENTRAL/SRN NEW ENGLAND.
DESPITE LIGHT NORTHERLY FLOW...NO APPRECIABLE AIRMASS CHANGE
EXPECTED AND MUCH DRIER AIR OFF TO OUR NORTH ACROSS SRN ON/QE
REALLY WON`T MAKE APPRECIABLE INROADS INTO OUR AREA. VARIABLY
CLOUDY SKIES AND PATCHY BR/FG THIS MORNING SHOULD SCOUR OUT TO
PTLY SUNNY IN MANY AREAS THIS AFTERNOON AS PBL DEEPENS. STILL
COULD SEE AN ISOLD LATE AFTERNOON/EARLY EVENING SHOWER/STORM FAR
SOUTH IN CLOSER PROXIMITY TO OLD BOUNDARY AND DEEPER MOISTURE
AXIS...BUT DRY WEATHER WILL BE THE GENERAL RULE. BLENDED 18-00Z
MODEL 925 MB THERMAL PROGS SUPPORT BLENDED MOS LATE AFTERNOON
HIGHS IN THE 72 TO 78 DEGREE RANGE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
AS OF 344 AM EDT WEDNESDAY...THEN QUIET TONIGHT AS DEEP LAYER SFC
TO H5 RIDGING BEGINS TO BUILD BACK ACROSS THE REGION. MAINLY
CLR/PTLY CLOUDY SKIES EXPECTED...THOUGH AS FLOW TRENDS LIGHT
SOUTH/SOUTHEASTERLY OVERNIGHT A DECENT CHANCE THAT SOME LOWER
CLOUD COVER MAY BEGIN TO ENCROACH BACK NORTHWARD INTO OUR SRN/SERN
VT COUNTIES AFTER MIDNIGHT. PATCHY FOG ALSO A GOOD BET AS WET
GROUND CONDS FOSTER SATURATION IN THE NEAR-SFC LAYERS. LOWS
SIMILAR TO THIS MORNING...MAINLY 50S TO LOCALLY NEAR 60 IN MILDER
SPOTS OF THE CHAMPLAIN VALLEY.
BY THURSDAY RIDGING WILL BECOME WELL ESTABLISHED ACROSS THE AREA AS
SOUTHERLY FLOW SLOWLY INCREASES AND TRENDS MODESTLY GUSTY BY
AFTERNOON. STILL AN OUTSIDE CHANCE OF A FEW SHOWERS/STRAY STORMS
HERE AND THERE DURING PEAK HEATING HOURS SOUTH AS SFC INSOLATION
ACTS ON RESIDUAL MOISTURE AXIS...OTHERWISE DRY AND PTLY SUNNY
SHOULD BE THE RULE IN MOST LOCALES. TEMPERATURES A TAD WARMER INTO
THE 77 TO 83 RANGE...CONTINUING RECENT STRING OF ABOVE NORMAL DAYS.
THEN PTLY/MOSTLY CLOUDY AND MILD THURSDAY NIGHT AS TEMPERATURES HOLD
IN THE UPPER 50S TO LOWER 60S.
BY FRIDAY...GUSTY SOUTHERLY FLOW CONTINUES ACROSS THE AREA ALONG
WITH A CONTINUED ISOLD THREAT OF A FEW SHOWERS/STORMS HERE AND THERE
BY THE AFTERNOON/EARLY EVENING HOURS. BEST THREAT APPEARS TO OCCUR
ACROSS THE SLV WHERE ADDED MOISTURE CONVERGENCE AND APPROACHING
WEAK FRONTAL SYSTEM MAY AID IN SOMEWHAT HIGHER COVERAGE TOWARD
EVENING. CONTINUED UNSEASONABLY WARM WITH HIGHS 78 TO 85 AND MODEST
HUMIDITY LEVELS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 445 AM EDT WEDNESDAY...THE PERIOD WILL START WITH A COLD
FRONT TRAVERSING OVER THE FCST AREA. 00Z GFS AND ECMWF DIFFER ON
TIMING OF FRONTAL PASSAGE...BUT BOTH MODELS SHOW FRONT LINGERING
ALONG THE ATLANTIC COAST BY SATURDAY NIGHT. HIGH PRESSURE WILL
THEN BUILD IN AT THE SFC FROM SOUTHERN QUEBEC...GIVING A SHORT
DRY PERIOD ON SATURDAY INTO EARLY SUNDAY. LATE SUNDAY...MODEL
GUIDANCE INDICATES AN UPPER LEVEL DISTURBANCE/WEAK SHORT WAVE
WILL MOVE OVER THE REGION...WITH AN UPPER LEVEL JET TO OUR NORTH.
INCREASED INSTABILITY LATE SUNDAY INTO MONDAY WITH GFS INDICATING
CAPE VALUES OVER 1000J/KG AND NEGATIVE LIFTED INDICES. ECMWF
KEEPS THE HIGH CAPE VALUE TO OUR SOUTH.
THE AFOREMENTIONED COLD FRONT WILL LIFT NORTHWARD AS A WARM FRONT
AS LOW PRESSURE CENTER AT THE SFC MOVES FROM THE NWRN GREAT LAKES
TO SE ONTARIO MONDAY AND TUESDAY. THIS WILL CONTINUE TO PRODUCE
CHANCE OF SHOWERS.
TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL...WITH A SLGT
COOLING TREND TO START. 850HPA TEMPS WILL COOL FROM THE MID TEENS
TO 10C-12C SUNDAY. ECWMF HAS FRONT SYSTEM BEING STRONGER THAN GFS
AND BRINGS SINGLE DIGIT TEMPS AT 850HPA BY MONDAY MORNING. BOTH
MODELS DO SHOW DECENT TEMP GRADIENT OVER THE NORTHEAST WHICH WILL
HELP WITH POTENTIAL FOR CONVECTIVE ACTIVITY. BOTH MODELS WARM
TEMPS ON MONDAY TO MID TO UPPER TEENS AT 850HPA...BUT GRADUALLY
COOLING ON TUESDAY.
&&
.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...CLOUDS WILL GRADUALLY DISSIPATE THIS
MORNING...WITH IMPROVING VSBYS. OVERALL FLIGHT CONDITIONS WILL
IMPROVE TO MVFR BY LATE MORNING...15Z AT KBTV/KPBG/RUT/
CONDITIONS WILL CONTINUE TO IMPROVE TO VFR BY LATE MORNING/EARLY
AFTERNOON AT ALL TERMINALS. CLOUDS WILL GENERALLY BECOME SCT TO
BKN MID AND HIGH LEVEL FOR THE AFTERNOON AND EVENING.
OVERNIGHT...MOISTURE WILL SURGE NORTHWARD INTO THE
AREA...ALLOWING FOR MVFR CONDITIONS TO DEVELOP AROUND 05Z-06Z
THROUGH THURSDAY MORNING.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY... 12Z THURSDAY THROUGH 18Z
FRIDAY...GENERALLY VFR UNDER RIDGE OF HIGH PRESSURE...ALTHOUGH
SOME FOG/BR POSSIBLE THURSDAY MORNING. 18Z FRIDAY THROUGH
SUNDAY...GENERALLY VFR BUT BRIEF PERIODS OF MVFR POSSIBLE IN
SCATTERED SHOWERS/TSTORMS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/TABER
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1031 AM EDT WED MAY 23 2012
.SYNOPSIS...
OUTSIDE A STRAY AFTERNOON OR EARLY EVENING SHOWER OR STORM...MAINLY
DRY WEATHER IS EXPECTED THROUGH THURSDAY WITH WARM TEMPERATURES AND
MODEST HUMIDITY LEVELS. A WEAKENING COLD FRONT WILL PUSH THROUGH THE
AREA FRIDAY NIGHT INTO SATURDAY THOUGH AGAIN SHOWERY PRECIPITATION
WILL BE SCATTERED AT BEST. WARM TEMPERATURES CONTINUE INTO NEXT WEEK
WITH MORE ACTIVE WEATHER POSSIBLE AS SHOWERS AND THUNDERSTORMS WILL
BE MORE COMMON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1013 AM EDT WEDNESDAY...SEVERAL MINOR UPDATES TO CRNT
FCST...BASED ON VIS SATL PICS AND CRNT OBS. VIS SATL PIC SHOWS
SOME BREAKS ACRS THE HIGHER ELEVATIONS OF THE DACKS AND SOME
CLRING ACRS THE SLV. SOUNDINGS SHOW SOLID RH PROFILES THRU
18Z...THEN SOME CLRING. WL USE VIS SALT TOOL IN GFE TO CAPTURE
CRNT TRENDS...THEN TAPER OVERALL AREAL COVERAGE OF CLOUDS AFT 18Z
THIS AFTN...BASED ON SOUNDING RH PROFILES. OTHERWISE...HAVE DECREASED HRLY
TEMPS THIS MORNING DUE TO CLOUDS...BUT FEEL AS BREAKS DEVELOP THIS
AFTN...TEMPS WL CLIMB QUICKLY. REST OF FCST IN GREAT SHAPE.
MODEST ADJUSTMENTS TO SKY COVER TO KEEP MOSTLY CLOUDY CONDS ACROSS
MUCH OF THE AREA THROUGH THE MORNING HOURS BASED OFF CURRENT
OBSERVATIONAL/SATELLITE TRENDS AND LATEST RAP 925MB RH PROGS. ALSO
NUDGED MAX TEMPS DOWN JUST A TAD (1-2 DEG). REST OF FCST
UNCHANGED.
PRIOR DISCUSSION...
WEAK AND DISSOLVING FRONTAL SYSTEM CONTINUES TO SAG EVER SO
SLOWLY SOUTHWARD THROUGH THE FORECAST AREA THIS MORNING AS WINDS
HAVE SHIFTED TO LIGHT NORTH/NORTHEASTERLY ACROSS OUR NRN COUNTIES
AS OF 3 AM. STILL A FEW SHOWERS/PATCHY -DZ AROUND THE AREA WITH
NEAR SATURATED LOWER LEVELS. OTHERWISE A RATHER UNEVENTFUL DAY ON
TAP WEATHERWISE FOR THE REGION AS AFOREMENTIONED FRONTAL SYSTEM
DISSIPATES TO OUR IMMEDIATE SOUTH ACROSS CENTRAL/SRN NEW ENGLAND.
DESPITE LIGHT NORTHERLY FLOW...NO APPRECIABLE AIRMASS CHANGE
EXPECTED AND MUCH DRIER AIR OFF TO OUR NORTH ACROSS SRN ON/QE
REALLY WON`T MAKE APPRECIABLE INROADS INTO OUR AREA. VARIABLY
CLOUDY SKIES AND PATCHY BR/FG THIS MORNING SHOULD SCOUR OUT TO
PTLY SUNNY IN MANY AREAS THIS AFTERNOON AS PBL DEEPENS. STILL
COULD SEE AN ISOLD LATE AFTERNOON/EARLY EVENING SHOWER/STORM FAR
SOUTH IN CLOSER PROXIMITY TO OLD BOUNDARY AND DEEPER MOISTURE
AXIS...BUT DRY WEATHER WILL BE THE GENERAL RULE. BLENDED 18-00Z
MODEL 925 MB THERMAL PROGS SUPPORT BLENDED MOS LATE AFTERNOON
HIGHS IN THE 72 TO 78 DEGREE RANGE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
AS OF 344 AM EDT WEDNESDAY...THEN QUIET TONIGHT AS DEEP LAYER SFC
TO H5 RIDGING BEGINS TO BUILD BACK ACROSS THE REGION. MAINLY
CLR/PTLY CLOUDY SKIES EXPECTED...THOUGH AS FLOW TRENDS LIGHT
SOUTH/SOUTHEASTERLY OVERNIGHT A DECENT CHANCE THAT SOME LOWER
CLOUD COVER MAY BEGIN TO ENCROACH BACK NORTHWARD INTO OUR SRN/SERN
VT COUNTIES AFTER MIDNIGHT. PATCHY FOG ALSO A GOOD BET AS WET
GROUND CONDS FOSTER SATURATION IN THE NEAR-SFC LAYERS. LOWS
SIMILAR TO THIS MORNING...MAINLY 50S TO LOCALLY NEAR 60 IN MILDER
SPOTS OF THE CHAMPLAIN VALLEY.
BY THURSDAY RIDGING WILL BECOME WELL ESTABLISHED ACROSS THE AREA AS
SOUTHERLY FLOW SLOWLY INCREASES AND TRENDS MODESTLY GUSTY BY
AFTERNOON. STILL AN OUTSIDE CHANCE OF A FEW SHOWERS/STRAY STORMS
HERE AND THERE DURING PEAK HEATING HOURS SOUTH AS SFC INSOLATION
ACTS ON RESIDUAL MOISTURE AXIS...OTHERWISE DRY AND PTLY SUNNY
SHOULD BE THE RULE IN MOST LOCALES. TEMPERATURES A TAD WARMER INTO
THE 77 TO 83 RANGE...CONTINUING RECENT STRING OF ABOVE NORMAL DAYS.
THEN PTLY/MOSTLY CLOUDY AND MILD THURSDAY NIGHT AS TEMPERATURES HOLD
IN THE UPPER 50S TO LOWER 60S.
BY FRIDAY...GUSTY SOUTHERLY FLOW CONTINUES ACROSS THE AREA ALONG
WITH A CONTINUED ISOLD THREAT OF A FEW SHOWERS/STORMS HERE AND THERE
BY THE AFTERNOON/EARLY EVENING HOURS. BEST THREAT APPEARS TO OCCUR
ACROSS THE SLV WHERE ADDED MOISTURE CONVERGENCE AND APPROACHING
WEAK FRONTAL SYSTEM MAY AID IN SOMEWHAT HIGHER COVERAGE TOWARD
EVENING. CONTINUED UNSEASONABLY WARM WITH HIGHS 78 TO 85 AND MODEST
HUMIDITY LEVELS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 445 AM EDT WEDNESDAY...THE PERIOD WILL START WITH A COLD
FRONT TRAVERSING OVER THE FCST AREA. 00Z GFS AND ECMWF DIFFER ON
TIMING OF FRONTAL PASSAGE...BUT BOTH MODELS SHOW FRONT LINGERING
ALONG THE ATLANTIC COAST BY SATURDAY NIGHT. HIGH PRESSURE WILL
THEN BUILD IN AT THE SFC FROM SOUTHERN QUEBEC...GIVING A SHORT
DRY PERIOD ON SATURDAY INTO EARLY SUNDAY. LATE SUNDAY...MODEL
GUIDANCE INDICATES AN UPPER LEVEL DISTURBANCE/WEAK SHORT WAVE
WILL MOVE OVER THE REGION...WITH AN UPPER LEVEL JET TO OUR NORTH.
INCREASED INSTABILITY LATE SUNDAY INTO MONDAY WITH GFS INDICATING
CAPE VALUES OVER 1000J/KG AND NEGATIVE LIFTED INDICES. ECMWF
KEEPS THE HIGH CAPE VALUE TO OUR SOUTH.
THE AFOREMENTIONED COLD FRONT WILL LIFT NORTHWARD AS A WARM FRONT
AS LOW PRESSURE CENTER AT THE SFC MOVES FROM THE NWRN GREAT LAKES
TO SE ONTARIO MONDAY AND TUESDAY. THIS WILL CONTINUE TO PRODUCE
CHANCE OF SHOWERS.
TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL...WITH A SLGT
COOLING TREND TO START. 850HPA TEMPS WILL COOL FROM THE MID TEENS
TO 10C-12C SUNDAY. ECWMF HAS FRONT SYSTEM BEING STRONGER THAN GFS
AND BRINGS SINGLE DIGIT TEMPS AT 850HPA BY MONDAY MORNING. BOTH
MODELS DO SHOW DECENT TEMP GRADIENT OVER THE NORTHEAST WHICH WILL
HELP WITH POTENTIAL FOR CONVECTIVE ACTIVITY. BOTH MODELS WARM
TEMPS ON MONDAY TO MID TO UPPER TEENS AT 850HPA...BUT GRADUALLY
COOLING ON TUESDAY.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...CLOUDS WILL GRADUALLY DISSIPATE THIS
MORNING...WITH IMPROVING VSBYS. OVERALL FLIGHT CONDITIONS WILL
IMPROVE TO MVFR BY LATE MORNING...15Z AT KBTV/KPBG/RUT/
CONDITIONS WILL CONTINUE TO IMPROVE TO VFR BY LATE MORNING/EARLY
AFTERNOON AT ALL TERMINALS. CLOUDS WILL GENERALLY BECOME SCT TO
BKN MID AND HIGH LEVEL FOR THE AFTERNOON AND EVENING.
OVERNIGHT...MOISTURE WILL SURGE NORTHWARD INTO THE
AREA...ALLOWING FOR MVFR CONDITIONS TO DEVELOP AROUND 05Z-06Z
THROUGH THURSDAY MORNING.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY... 12Z THURSDAY THROUGH 18Z
FRIDAY...GENERALLY VFR UNDER RIDGE OF HIGH PRESSURE...ALTHOUGH
SOME FOG/BR POSSIBLE THURSDAY MORNING. 18Z FRIDAY THROUGH
SUNDAY...GENERALLY VFR BUT BRIEF PERIODS OF MVFR POSSIBLE IN
SCATTERED SHOWERS/TSTORMS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/TABER
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
751 AM EDT WED MAY 23 2012
.SYNOPSIS...
OUTSIDE A STRAY AFTERNOON OR EARLY EVENING SHOWER OR STORM...MAINLY
DRY WEATHER IS EXPECTED THROUGH THURSDAY WITH WARM TEMPERATURES AND
MODEST HUMIDITY LEVELS. A WEAKENING COLD FRONT WILL PUSH THROUGH THE
AREA FRIDAY NIGHT INTO SATURDAY THOUGH AGAIN SHOWERY PRECIPITATION
WILL BE SCATTERED AT BEST. WARM TEMPERATURES CONTINUE INTO NEXT WEEK
WITH MORE ACTIVE WEATHER POSSIBLE AS SHOWERS AND THUNDERSTORMS WILL
BE MORE COMMON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 722 AM EDT WEDNESDAY...MODEST ADJUSTMENTS TO SKY COVER TO
KEEP MOSTLY CLOUDY CONDS ACROSS MUCH OF THE AREA THROUGH THE
MORNING HOURS BASED OFF CURRENT OBSERVATIONAL/SATELLITE TRENDS AND
LATEST RAP 925MB RH PROGS. ALSO NUDGED MAX TEMPS DOWN JUST A TAD
(1-2 DEG). REST OF FCST UNCHANGED.
PRIOR DISCUSSION...
WEAK AND DISSOLVING FRONTAL SYSTEM CONTINUES TO SAG EVER SO
SLOWLY SOUTHWARD THROUGH THE FORECAST AREA THIS MORNING AS WINDS
HAVE SHIFTED TO LIGHT NORTH/NORTHEASTERLY ACROSS OUR NRN COUNTIES
AS OF 3 AM. STILL A FEW SHOWERS/PATCHY -DZ AROUND THE AREA WITH
NEAR SATURATED LOWER LEVELS. OTHERWISE A RATHER UNEVENTFUL DAY ON
TAP WEATHERWISE FOR THE REGION AS AFOREMENTIONED FRONTAL SYSTEM
DISSIPATES TO OUR IMMEDIATE SOUTH ACROSS CENTRAL/SRN NEW ENGLAND.
DESPITE LIGHT NORTHERLY FLOW...NO APPRECIABLE AIRMASS CHANGE
EXPECTED AND MUCH DRIER AIR OFF TO OUR NORTH ACROSS SRN ON/QE
REALLY WON`T MAKE APPRECIABLE INROADS INTO OUR AREA. VARIABLY
CLOUDY SKIES AND PATCHY BR/FG THIS MORNING SHOULD SCOUR OUT TO
PTLY SUNNY IN MANY AREAS THIS AFTERNOON AS PBL DEEPENS. STILL
COULD SEE AN ISOLD LATE AFTERNOON/EARLY EVENING SHOWER/STORM FAR
SOUTH IN CLOSER PROXIMITY TO OLD BOUNDARY AND DEEPER MOISTURE
AXIS...BUT DRY WEATHER WILL BE THE GENERAL RULE. BLENDED 18-00Z
MODEL 925 MB THERMAL PROGS SUPPORT BLENDED MOS LATE AFTERNOON
HIGHS IN THE 72 TO 78 DEGREE RANGE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
AS OF 344 AM EDT WEDNESDAY...THEN QUIET TONIGHT AS DEEP LAYER SFC
TO H5 RIDGING BEGINS TO BUILD BACK ACROSS THE REGION. MAINLY
CLR/PTLY CLOUDY SKIES EXPECTED...THOUGH AS FLOW TRENDS LIGHT
SOUTH/SOUTHEASTERLY OVERNIGHT A DECENT CHANCE THAT SOME LOWER
CLOUD COVER MAY BEGIN TO ENCROACH BACK NORTHWARD INTO OUR SRN/SERN
VT COUNTIES AFTER MIDNIGHT. PATCHY FOG ALSO A GOOD BET AS WET
GROUND CONDS FOSTER SATURATION IN THE NEAR-SFC LAYERS. LOWS
SIMILAR TO THIS MORNING...MAINLY 50S TO LOCALLY NEAR 60 IN MILDER
SPOTS OF THE CHAMPLAIN VALLEY.
BY THURSDAY RIDGING WILL BECOME WELL ESTABLISHED ACROSS THE AREA AS
SOUTHERLY FLOW SLOWLY INCREASES AND TRENDS MODESTLY GUSTY BY
AFTERNOON. STILL AN OUTSIDE CHANCE OF A FEW SHOWERS/STRAY STORMS
HERE AND THERE DURING PEAK HEATING HOURS SOUTH AS SFC INSOLATION
ACTS ON RESIDUAL MOISTURE AXIS...OTHERWISE DRY AND PTLY SUNNY
SHOULD BE THE RULE IN MOST LOCALES. TEMPERATURES A TAD WARMER INTO
THE 77 TO 83 RANGE...CONTINUING RECENT STRING OF ABOVE NORMAL DAYS.
THEN PTLY/MOSTLY CLOUDY AND MILD THURSDAY NIGHT AS TEMPERATURES HOLD
IN THE UPPER 50S TO LOWER 60S.
BY FRIDAY...GUSTY SOUTHERLY FLOW CONTINUES ACROSS THE AREA ALONG
WITH A CONTINUED ISOLD THREAT OF A FEW SHOWERS/STORMS HERE AND THERE
BY THE AFTERNOON/EARLY EVENING HOURS. BEST THREAT APPEARS TO OCCUR
ACROSS THE SLV WHERE ADDED MOISTURE CONVERGENCE AND APPROACHING
WEAK FRONTAL SYSTEM MAY AID IN SOMEWHAT HIGHER COVERAGE TOWARD
EVENING. CONTINUED UNSEASONABLY WARM WITH HIGHS 78 TO 85 AND MODEST
HUMIDITY LEVELS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 445 AM EDT WEDNESDAY...THE PERIOD WILL START WITH A COLD
FRONT TRAVERSING OVER THE FCST AREA. 00Z GFS AND ECMWF DIFFER ON
TIMING OF FRONTAL PASSAGE...BUT BOTH MODELS SHOW FRONT LINGERING
ALONG THE ATLANTIC COAST BY SATURDAY NIGHT. HIGH PRESSURE WILL
THEN BUILD IN AT THE SFC FROM SOUTHERN QUEBEC...GIVING A SHORT
DRY PERIOD ON SATURDAY INTO EARLY SUNDAY. LATE SUNDAY...MODEL
GUIDANCE INDICATES AN UPPER LEVEL DISTURBANCE/WEAK SHORT WAVE
WILL MOVE OVER THE REGION...WITH AN UPPER LEVEL JET TO OUR NORTH.
INCREASED INSTABILITY LATE SUNDAY INTO MONDAY WITH GFS INDICATING
CAPE VALUES OVER 1000J/KG AND NEGATIVE LIFTED INDICES. ECMWF
KEEPS THE HIGH CAPE VALUE TO OUR SOUTH.
THE AFOREMENTIONED COLD FRONT WILL LIFT NORTHWARD AS A WARM FRONT
AS LOW PRESSURE CENTER AT THE SFC MOVES FROM THE NWRN GREAT LAKES
TO SE ONTARIO MONDAY AND TUESDAY. THIS WILL CONTINUE TO PRODUCE
CHANCE OF SHOWERS.
TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL...WITH A SLGT
COOLING TREND TO START. 850HPA TEMPS WILL COOL FROM THE MID TEENS
TO 10C-12C SUNDAY. ECWMF HAS FRONT SYSTEM BEING STRONGER THAN GFS
AND BRINGS SINGLE DIGIT TEMPS AT 850HPA BY MONDAY MORNING. BOTH
MODELS DO SHOW DECENT TEMP GRADIENT OVER THE NORTHEAST WHICH WILL
HELP WITH POTENTIAL FOR CONVECTIVE ACTIVITY. BOTH MODELS WARM
TEMPS ON MONDAY TO MID TO UPPER TEENS AT 850HPA...BUT GRADUALLY
COOLING ON TUESDAY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...CLOUDS WILL GRADUALLY DISSIPATE THIS
MORNING...WITH IMPROVING VSBYS. OVERALL FLIGHT CONDITIONS WILL
IMPROVE TO MVFR BY LATE MORNING...15Z AT KBTV/KPBG/RUT/
CONDITIONS WILL CONTINUE TO IMPROVE TO VFR BY LATE MORNING/EARLY
AFTERNOON AT ALL TERMINALS. CLOUDS WILL GENERALLY BECOME SCT TO
BKN MID AND HIGH LEVEL FOR THE AFTERNOON AND EVENING.
OVERNIGHT...MOISTURE WILL SURGE NORTHWARD INTO THE
AREA...ALLOWING FOR MVFR CONDITIONS TO DEVELOP AROUND 05Z-06Z
THROUGH THURSDAY MORNING.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY... 12Z THURSDAY THROUGH 18Z
FRIDAY...GENERALLY VFR UNDER RIDGE OF HIGH PRESSURE...ALTHOUGH
SOME FOG/BR POSSIBLE THURSDAY MORNING. 18Z FRIDAY THROUGH
SUNDAY...GENERALLY VFR BUT BRIEF PERIODS OF MVFR POSSIBLE IN
SCATTERED SHOWERS/TSTORMS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
722 AM EDT WED MAY 23 2012
.SYNOPSIS...
OUTSIDE A STRAY AFTERNOON OR EARLY EVENING SHOWER OR STORM...MAINLY
DRY WEATHER IS EXPECTED THROUGH THURSDAY WITH WARM TEMPERATURES AND
MODEST HUMIDITY LEVELS. A WEAKENING COLD FRONT WILL PUSH THROUGH THE
AREA FRIDAY NIGHT INTO SATURDAY THOUGH AGAIN SHOWERY PRECIPITATION
WILL BE SCATTERED AT BEST. WARM TEMPERATURES CONTINUE INTO NEXT WEEK
WITH MORE ACTIVE WEATHER POSSIBLE AS SHOWERS AND THUNDERSTORMS WILL
BE MORE COMMON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 722 AM EDT WEDNESDAY...MODEST ADJUSTMENTS TO SKY COVER TO
KEEP MOSTLY CLOUDY CONDS ACROSS MUCH OF THE AREA THROUGH THE
MORNING HOURS BASED OFF CURRENT OBSERVATIONAL/SATELLITE TRENDS AND
LATEST RAP 925MB RH PROGS. ALSO NUDGED MAX TEMPS DOWN JUST A TAD
(1-2 DEG). REST OF FCST UNCHANGED.
PRIOR DISCUSSION...
WEAK AND DISSOLVING FRONTAL SYSTEM CONTINUES TO SAG EVER SO
SLOWLY SOUTHWARD THROUGH THE FORECAST AREA THIS MORNING AS WINDS
HAVE SHIFTED TO LIGHT NORTH/NORTHEASTERLY ACROSS OUR NRN COUNTIES
AS OF 3 AM. STILL A FEW SHOWERS/PATCHY -DZ AROUND THE AREA WITH
NEAR SATURATED LOWER LEVELS. OTHERWISE A RATHER UNEVENTFUL DAY ON
TAP WEATHERWISE FOR THE REGION AS AFOREMENTIONED FRONTAL SYSTEM
DISSIPATES TO OUR IMMEDIATE SOUTH ACROSS CENTRAL/SRN NEW ENGLAND.
DESPITE LIGHT NORTHERLY FLOW...NO APPRECIABLE AIRMASS CHANGE
EXPECTED AND MUCH DRIER AIR OFF TO OUR NORTH ACROSS SRN ON/QE
REALLY WON`T MAKE APPRECIABLE INROADS INTO OUR AREA. VARIABLY
CLOUDY SKIES AND PATCHY BR/FG THIS MORNING SHOULD SCOUR OUT TO
PTLY SUNNY IN MANY AREAS THIS AFTERNOON AS PBL DEEPENS. STILL
COULD SEE AN ISOLD LATE AFTERNOON/EARLY EVENING SHOWER/STORM FAR
SOUTH IN CLOSER PROXIMITY TO OLD BOUNDARY AND DEEPER MOISTURE
AXIS...BUT DRY WEATHER WILL BE THE GENERAL RULE. BLENDED 18-00Z
MODEL 925 MB THERMAL PROGS SUPPORT BLENDED MOS LATE AFTERNOON
HIGHS IN THE 72 TO 78 DEGREE RANGE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
AS OF 344 AM EDT WEDNESDAY...THEN QUIET TONIGHT AS DEEP LAYER SFC
TO H5 RIDGING BEGINS TO BUILD BACK ACROSS THE REGION. MAINLY
CLR/PTLY CLOUDY SKIES EXPECTED...THOUGH AS FLOW TRENDS LIGHT
SOUTH/SOUTHEASTERLY OVERNIGHT A DECENT CHANCE THAT SOME LOWER
CLOUD COVER MAY BEGIN TO ENCROACH BACK NORTHWARD INTO OUR SRN/SERN
VT COUNTIES AFTER MIDNIGHT. PATCHY FOG ALSO A GOOD BET AS WET
GROUND CONDS FOSTER SATURATION IN THE NEAR-SFC LAYERS. LOWS
SIMILAR TO THIS MORNING...MAINLY 50S TO LOCALLY NEAR 60 IN MILDER
SPOTS OF THE CHAMPLAIN VALLEY.
BY THURSDAY RIDGING WILL BECOME WELL ESTABLISHED ACROSS THE AREA AS
SOUTHERLY FLOW SLOWLY INCREASES AND TRENDS MODESTLY GUSTY BY
AFTERNOON. STILL AN OUTSIDE CHANCE OF A FEW SHOWERS/STRAY STORMS
HERE AND THERE DURING PEAK HEATING HOURS SOUTH AS SFC INSOLATION
ACTS ON RESIDUAL MOISTURE AXIS...OTHERWISE DRY AND PTLY SUNNY
SHOULD BE THE RULE IN MOST LOCALES. TEMPERATURES A TAD WARMER INTO
THE 77 TO 83 RANGE...CONTINUING RECENT STRING OF ABOVE NORMAL DAYS.
THEN PTLY/MOSTLY CLOUDY AND MILD THURSDAY NIGHT AS TEMPERATURES HOLD
IN THE UPPER 50S TO LOWER 60S.
BY FRIDAY...GUSTY SOUTHERLY FLOW CONTINUES ACROSS THE AREA ALONG
WITH A CONTINUED ISOLD THREAT OF A FEW SHOWERS/STORMS HERE AND THERE
BY THE AFTERNOON/EARLY EVENING HOURS. BEST THREAT APPEARS TO OCCUR
ACROSS THE SLV WHERE ADDED MOISTURE CONVERGENCE AND APPROACHING
WEAK FRONTAL SYSTEM MAY AID IN SOMEWHAT HIGHER COVERAGE TOWARD
EVENING. CONTINUED UNSEASONABLY WARM WITH HIGHS 78 TO 85 AND MODEST
HUMIDITY LEVELS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 445 AM EDT WEDNESDAY...THE PERIOD WILL START WITH A COLD
FRONT TRAVERSING OVER THE FCST AREA. 00Z GFS AND ECMWF DIFFER ON
TIMING OF FRONTAL PASSAGE...BUT BOTH MODELS SHOW FRONT LINGERING
ALONG THE ATLANTIC COAST BY SATURDAY NIGHT. HIGH PRESSURE WILL
THEN BUILD IN AT THE SFC FROM SOUTHERN QUEBEC...GIVING A SHORT
DRY PERIOD ON SATURDAY INTO EARLY SUNDAY. LATE SUNDAY...MODEL
GUIDANCE INDICATES AN UPPER LEVEL DISTURBANCE/WEAK SHORT WAVE
WILL MOVE OVER THE REGION...WITH AN UPPER LEVEL JET TO OUR NORTH.
INCREASED INSTABILITY LATE SUNDAY INTO MONDAY WITH GFS INDICATING
CAPE VALUES OVER 1000J/KG AND NEGATIVE LIFTED INDICES. ECMWF
KEEPS THE HIGH CAPE VALUE TO OUR SOUTH.
THE AFOREMENTIONED COLD FRONT WILL LIFT NORTHWARD AS A WARM FRONT
AS LOW PRESSURE CENTER AT THE SFC MOVES FROM THE NWRN GREAT LAKES
TO SE ONTARIO MONDAY AND TUESDAY. THIS WILL CONTINUE TO PRODUCE
CHANCE OF SHOWERS.
TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL...WITH A SLGT
COOLING TREND TO START. 850HPA TEMPS WILL COOL FROM THE MID TEENS
TO 10C-12C SUNDAY. ECWMF HAS FRONT SYSTEM BEING STRONGER THAN GFS
AND BRINGS SINGLE DIGIT TEMPS AT 850HPA BY MONDAY MORNING. BOTH
MODELS DO SHOW DECENT TEMP GRADIENT OVER THE NORTHEAST WHICH WILL
HELP WITH POTENTIAL FOR CONVECTIVE ACTIVITY. BOTH MODELS WARM
TEMPS ON MONDAY TO MID TO UPPER TEENS AT 850HPA...BUT GRADUALLY
COOLING ON TUESDAY.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 06Z THURSDAY...WIDELY VARYING CONDITIONS ACROSS THE
NORTHEAST AS FRONTAL PASSAGE HAS SHIFTED WINDS TO THE NE AT KMSS
AND NW AT KBTV AND KPBG.
IFR/LIFR CONDITIONS AT KBTV AND KPBG EXPECTED OVERNIGHT AS KBTV
IS EXPERIENCING -RA/-DZ WITH NW FLOW CONVERGING LIFR CIGS OVER
THE TAF SITE. PERSISTENT NW FLOW WILL CONTINUE POOR CONDITIONS
OVER BTV AT LIFR TO IFR THROUGH THE REST OF THE OVERNIGHT INTO
WEDNESDAY MORNING. KPBG SLIGHTLY BETTER CONDITIONS WITH IFR/MVFR
EXPECTED OVERNIGHT. CONDITIONS AT BOTH KBTV AND KPBG WILL IMPROVE
IN THE LATE MORNING TO VFR AND CONTINUE TO IMPROVE AS THE BACK
EDGE OF THE CLOUD SHIELD APPROACHES IN THE LATE MORNING/EARLY
AFTERNOON WITH SLIGHTLY DRIER AIR FILTERING IN AS WELL.
VFR/MVFR CONDITIONS AT REST OF THE TAF SITES WILL PERSIST
OVERNIGHT...DETERIORATING TO IFR AT KSLK. HAVE ALSO INCLUDED
TEMPOS FOR IFR CIGS AT KMPV AND KMSS.
WITH LACK OF WINDS AND ONLY LIGHT FLOW ALOFT...CLOUDS WILL BE
SLOW TO LIFT WEDNESDAY MORNING. BUT OVERALL IMPROVEMENT TO VFR
EXPECTED AT ALL TAF SITES BY LATE MORNING. CONTINUED DIMINISHING
CLOUD COVER WILL CONTINUE IN THE AFTERNOON. MAY SEE AN ISOLATED
SHOWER AT RUT/MPV ON WEDNESDAY BUT LEFT OUT FOR NOW. AS EVENING
APPROACHES...CLOUDS WILL INCREASE FROM THE SOUTH AS MOISTURE
ADVECTS NORTHWARD.
OUTLOOK 06Z THURSDAY THROUGH SUNDAY...
06Z THURSDAY THROUGH 18Z FRIDAY...GENERALLY VFR UNDER RIDGE OF
HIGH PRESSURE...ALTHOUGH SOME FOG/BR POSSIBLE THURSDAY MORNING.
18Z FRIDAY THROUGH SUNDAY...GENERALLY VFR BUT BRIEF PERIODS OF
MVFR POSSIBLE IN SCATTERED SHOWERS/TSTORMS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
406 PM CDT WED MAY 23 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...
FORECAST CONCERNS THROUGH THURSDAY NIGHT ARE MAINLY FOCUSED AROUND
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS EVENING ACROSS
THE WEST...FOLLOWED BY AND CHANCES OF ADDITIONAL PRECIPITATION
THURSDAY INTO THURSDAY NIGHT. POTENTIAL FOR FROST THURSDAY NIGHT
IN THE WEST...BUT CLOUD COVER MAY INHIBIT WIDESPREAD FROST. NO SEVERE
WEATHER IS EXPECTED THROUGH THURSDAY NIGHT.
LATEST VISIBLE SATELLITE IMAGERY SHOWS AN INCREASING CUMULUS FIELD
OVER NORTHWEST AND NORTH CENTRAL NORTH DAKOTA. PER SPC MESOSCALE
ANALYSIS...STEEP LOW LEVEL LAPSE RATES AND MODERATE MID LEVEL
LAPSE RATES CONTINUE UNDERNEATH AN UPPER LOW SEEN CIRCULATING ACROSS
SOUTHERN SASKATCHEWAN. A COLD FRONT WAS ALSO NOTED ACROSS SOUTHERN
ALBERTA INTO SOUTHERN SASKATCHEWAN THIS AFTERNOON. THE 12Z 4KM WRF
INDICATES ISOLATED TO SCATTERED SHOWERS ALONG WITH ISOLATED
THUNDERSTORMS ACROSS THE WEST THROUGH SUNSET AND CONCUR WITH THIS
IDEA. CURRENT UPSTREAM RADAR SUPPORTS THIS. RAP SOUNDINGS PER
BUFKIT ADVERTISE CAPE VALUES RANGING BETWEEN 200 TO 400 J/KG AT
KISN/KMOT/KDIK. TQ INDICES OF 16C ALSO SUGGEST LOW TOP CONVECTION
POSSIBLE THUS WILL CONTINUE WITH ISOLATED MENTION OF THUNDERSTORMS.
WITH A LACK OF SHEAR...EXPECT PULSE TYPE THUNDERSTORMS WITH PERHAPS
PEA SIZED HAIL POSSIBLE. ACTIVITY WILL WANE WITH SUNSET...ENDING
BY 03Z THURSDAY.
ALSO NOTED WAS A SHORTWAVE SLIDING THROUGH EASTERN WYOMING THIS
AFTERNOON. LOCAL AND REGIONAL RADAR ALSO SHOW ECHOES OVER WESTERN
AND CENTRAL SOUTH DAKOTA REACHING INTO FAR SOUTH CENTRAL NORTH
DAKOTA. THIS APPEARS TO BE MAINLY ALOFT AS REPORTING STATIONS ARE
SHOWING SCT TO BKN MID LEVEL CLOUDS. HOWEVER WILL MAINTAIN
ISOLATED RAIN SHOWERS THROUGH 00Z THURSDAY TO COVER SHOWERS THAT
MAY REACH THE GROUND. THE THUNDERSTORM THREAT SHOULD REMAIN IN
EASTERN SOUTH DAKOTA INTO WESTERN MINNESOTA.
THE AFOREMENTIONED COLD FRONT WILL SAG SOUTHEAST TONIGHT WITH LOW
LEVEL COLD AIR ADVECTION COMMENCING ALL THE WAY THROUGH FRIDAY
MORNING. THIS WILL RESULT IN COOLER TEMPERATURES THROUGH THE
PERIOD. H85 TEMPS BETWEEN 0C AND -2C BECOME DOMINANT THURSDAY
NIGHT OVER NORTHERN AND WESTERN NORTH DAKOTA. SOME LOW LEVEL
MOISTURE/CLOUD COVER PER NAM 925MB RH FIELD MAY INHIBIT WIDESPREAD
LOW TEMPERATURES IN THE MID 30S. WILL CONTINUE TO MONITOR AND PASS
THIS ALONG TO FUTURE SHIFTS THAT A FROST ADVISORY MAY BE WARRANTED
LATE THURSDAY NIGHT INTO EARLY FRIDAY MORNING IN THE WEST AND NORTH.
WITH REGARDS TO PRECIPITATION...THE UPPER LOW SLOWLY MOVES FROM
SOUTHEASTERN SASKATCHEWAN TONIGHT INTO NORTHERN MINNESOTA BY FRIDAY
MORNING. MAIN IMPACT WOULD BE CHANCES OF SHOWERS OR THUNDERSTORMS
DURING PEAK HEATING WITH COLD AIR ALOFT AND DECENT LOW/MID LEVEL
LAPSE RATES. MODELS ARE IN GOOD AGREEMENT WITH MINIMAL ACTIVITY
THURSDAY...KEEPING THE PRECIPITATION CONFINED TO FAR WESTERN AND
FAR SOUTHERN NORTH DAKOTA THURSDAY INTO THURSDAY NIGHT.
.LONG TERM...FRIDAY THROUGH WEDNESDAY...
THE MAIN FOCUS THIS FORECAST PERIOD IS ON THE WIDESPREAD
PRECIPITATION EVENT FORECAST TO IMPACT NORTH DAKOTA FRIDAY NIGHT
THROUGH SUNDAY MORNING.
WATER VAPOR SATELLITE IMAGERY DEPICTS A MIDDLE/UPPER LEVEL LOW
OVER THE ALASKA PANHANDLE...WHICH IS FORECAST TO DIVE INTO THE
WESTERN U.S. AND EJECT A SERIES OF MIDDLE LEVEL SHORTWAVES INTO
THE DAKOTAS. STRONG LEE CYCLOGENESIS SHOULD SUPPORT FAVORABLE
MOISTURE TRANSPORT TO FUEL MODERATE TO HEAVY RAIN ACROSS THE
NORTHERN HIGH PLAINS. WHILE MONTANA IS MOST FAVORED FOR AMOUNTS
GREATER THAN AN INCH...STRONG AGEOSTROPHIC CIRCULATIONS JUSTIFY
INCREASING PRECIPITATION CHANCES OVER MUCH OF THE 12 UTC MOS
GUIDANCE. THE LOCATION OF 12 UTC ECMWF/GFS/GEFS MEAN/GEM GLOBAL H5
AND SURFACE LOWS FAVORS AREAS WELL EAST OF THE JAMES RIVER VALLEY
FOR STRONG TO SEVERE THUNDERSTORMS ON SATURDAY...BUT THE RECENT
TREND AMONG MODELS IS TO PULL THE H5 LOW A BIT FURTHER WEST. THIS
WILL NEED TO BE MONITORED...ESPECIALLY FOR SOUTHEASTERN NORTH
DAKOTA COUNTIES.
UNFORTUNATELY...THE WELCOME RAIN ACROSS MUCH OF THE STATE WILL
ARRIVE WITH TEMPERATURES LARGELY IN THE 40S. TEMPERATURES SHOULD
REMAIN BELOW AVERAGE THROUGH THE PERIOD.
&&
.AVIATION...
A FEW RAIN SHOWERS ARE POSSIBLE AT KISN AND KMOT. WIND DIRECTION
HAS BEEN A PROBLEM TODAY AS A COMPACT SURFACE TROUGH IS CAUSING WIND
TO SHIFT BETWEEN 240 AND 290. MVFR CLOUDS MAY SAG INTO KISN AND
KMOT EARLY THURSDAY MORNING ON THE WEST SIDE OF CANADIAN LOW
PRESSURE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM/AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1040 AM EDT WED MAY 23 2012
.SYNOPSIS...
UPPER AIR SYSTEM SLOWLY DRIFTS BY JUST TO OUR SOUTH...PROVIDING SLOW
MOVING CONVECTION AGAIN TODAY. WARMER AND DRIER AIR FOR THE END OF
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE...TWEAKED POPS SOME FOR TODAY...LEANING TOWARDS THE
HRRR AND RAP WHICH FIRE CONVECTION OVER THE MOUNTAINS EARLY THIS
AFTERNOON...AND THEN DRIFT IT SLOWLY WESTWARD AS THE STORMS RAIN
THEMSELVES OUT. ALSO THINK THERE WILL BE MORE ISOLATED POP UPS
ACROSS THE LOWLANDS TOWARDS THE OHIO RIVER...BUT EXACT TIMING AND
PLACEMENT OF THESE IS STILL MORE UNCERTAIN. NAM SHOWS SOME
1000J/KG+ CAPE IN NORTH CENTRAL CWA ALONG WITH SURFACE
CONVERGENCE...SO THAT COULD BE ONE POSSIBLE FOCUS AREA. COULD ALSO
SEE SOME BETTER DEVELOPMENT ALONG THE CLOUD EDGE/HEATING
DIFFERENTIAL LINE LATER THIS AFTERNOON.
PREVIOUS DISCUSSION...
NAM SEEMS TO HAVE A DECENT HANDLE ON CONVECTION ACROSS
EASTERN KY AND SW WV THIS MORNING...SO HAVE UPDATED POPS
ACCORDINGLY. MODELS SHOWING GOOD CONVECTION DEVELOPING ACROSS THE
MOUNTAINS THIS AFTERNOON. WITH A SATURATED ATMOSPHERE...CONCERNED
ABOUT HEAVY RAINFALL AMOUNTS. MODEL SOUNDINGS SHOWING THAT STORMS
WILL HAVE A BIT MORE MOVEMENT THAN TUESDAY...SHOWING ABOUT 5 KTS
FOR TODAY. WITH SOME STORM MOVEMENT...NOT INCLINED TO ISSUE A
WATCH. WILL HAVE TO KEEP AN EYE ON THE SITUATION THOUGH.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
BY THU UPR LOW HAS OPENED UP AS IT MOVES INTO NORTHERN MID ATLANTIC
STATES AMID BUILDING HEIGHTS SURGING NE FROM DIXIE. THIS WILL USHER
IN BEGINNINGS OF MUCH WARMER AIR INTO THE AREA HEADING INTO THE
HOLIDAY WEEKEND. ELECTED TO BUMP UP POS IN THE CENTRAL AND NORTHERN
MTNS TO LKLY WITH SOME SUN AIDING IN DESTABILIZATION ON ELEVATED
HEAT SRC AND PROXIMITY TO SOMEWHAT DEEPER MOISTURE. KEPT SCHC IN FOR
FRI...FOR THE MTNS WITH RESIDUAL SE UPSLOPE FLOW AND ELEVATED HEAT
SRC. OTHERWISE JUST SOME DAYTIME CU EXPECTED. WILL WATCH A VERY
WEAK BOUNDARY DECAY ON APPROACH TO SE OH FRI NIGHT. HAVE KEPT POPS
OUT OF THAT AREA GIVEN DRYING AHEAD OF IT. UPR RIDGE FLEXES MUSCLE
INTO AREA BY SAT WITH SIGNIFICANT DRYING ALOFT. WILL ALSO WATCH FOR
SUBTLE RIPPLE IN FLOW TRAVERSE DOWN RIDGE STAYING JUST NORTH AND
WEST OF AREA HOPEFULLY. ELECTED TO PUT SOME SCHC POPS IN FOR MTNS
THOUGH GIVEN PROXIMITY TO THIS FEATURE AND ELEVATED HEAT SRC
EFFECTS.
WARMUP BEGINS ON THU AND REALLY CRANKS FRI AND SAT. WITH RAINFALL
EARLY THIS WEEK AND H85 TEMPS ONLY ARND 18C...HARD PRESSED TO BITE
ON THE MID 90S FROM THE GFS FOR FRI AND SAT. HAVE HELD MAX T 90-92F
RANGE OUTSIDE OF THE MTNS FOR NOW. NIGHT TIME LOWS WILL BE QUITE
MILD AS WELL.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
UPPER RIDGE FIRMLY IN CONTROL OVER THE DEEP SOUTH...OHIO
VALLEY...AND CENTRAL AND SOUTHERN APPALACHIANS FOR THE BEGINNING
OF THE EXTENDED. AS HAS BEEN ADVERTISED...THIS WEEKEND WILL BRING
THE HIGHEST TEMPERATURES SO FAR THIS CALENDAR YEAR. 850MB
TEMPERATURES IN THE UPPER TEENS TO NEAR 20C WILL TRANSLATE TO
WIDESPREAD LOW TO MID 90S OVER THE LOWLANDS THIS WEEKEND WITH
UPPER 70S AND 80S IN THE HIGHER TERRAIN. HPC CAME IN OVER 100F AT
HTS THIS WEEKEND...AND APPEARED TO BE THE HIGHEST OF THE GUIDANCE.
PREFER THE CONSERVATIVE APPROACH FOR NOW...BUT STILL ON THE HIGHER
END OF THE MOS ENSEMBLE NUMBERS. BEING ON THE PERIPHERY OF THE
RIDGE...CANNOT KEEP THE FORECAST COMPLETELY DRY...AND INTRODUCE
LOW END POPS WITH SOME CONVECTION POTENTIAL BEGINNING SUNDAY.
INCREASE THE POPS WITH A COLD FRONT SLATED FOR EARLY NEXT WEEK AS
THE UPPER RIDGE RETREATS SOUTHWARD TOWARDS THE GULF OF MEXICO WITH
A RETURN INTO THE BETTER FLOW ALOFT. SOME UNCERTAINTY HERE ON THE
EXACT TIMING OF THE COLD FRONT PER USUAL BEYOND DAY 5...BUT HAVE
REASONABLE CONFIDENCE IN AN AIRMASS CHANGE FORTHCOMING WHICH
SHOULD BRING TEMPERATURES BACK DOWN TO NEAR NORMAL BY MID WEEK.
THIS IS EVIDENCED IN THE ECMWF 850MB TEMPERATURES COMING BACK DOWN
TO THE LOW TEENS. SHOULD BE ABLE TO BETTER ZERO IN ON THE TIMING
OF THE COLD FRONT IN UPCOMING FORECASTS...AND WITH THAT...AN
INCREASE IN THE POPS ACCORDINGLY. KEEP THE WEATHER IN A DIURNAL
REGIME...WITH THUNDER DURING HEATING HOURS AND SHOWERS FOR
ANYTHING AT NIGHT.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
THE ATMOSPHERE IS SATURATED WITH MOISTURE AT MOST LEVELS. THIS WILL
ALLOW FOR SOME CONTINUED CONVECTION THROUGH THE PERIOD...WITH BEST
COVERAGE DURING THE AFTERNOON AND EVENING HOURS. DENSE FOG WILL
GRADUALLY BURN OFF BY MID MORNING. A VFR/MVFR STRATUS DECK HAS BEEN
FLOATING AROUND THE AREA OVERNIGHT AND SHOULD TRANSITION INTO A BKN
MVFR/VFR CUMULUS DECK DURING THE DAYTIME HOURS. SOME DENSE FOG IS
POSSIBLE AGAIN TONIGHT...BUT MAY BREAK EARLY DUE TO SOME WINDS
STARTING TO PICK UP TOWARD DAY BREAK.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: TIMING OF SHOWERS/STORMS COULD VARY. WITH THE
ATMOSPHERE SATURATED AT MOST LEVELS...CLOUD DECKS COULD FORM AT
UNEXPECTED LEVELS. TIMING OF FOG BURNING OFF/LIFTING COULD VARY.
TIMING OF SHOWERS/STORMS MAY VARY. FOG AND LOW
STRATUS TIMING...INTENSITY...AND DURATION MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY L H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H M H H H H H H H M H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY M M H H H H H H H H H H
CKB CONSISTENCY L H H H H H H H H H H H
AFTER 12Z THURSDAY...
BRIEF IFR POSSIBLE IN THUNDERSTORMS ON THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30/26
NEAR TERM...RPY/MZ
SHORT TERM...30
LONG TERM...26
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
200 AM EDT WED MAY 23 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND THEN WEAKEN
WEDNESDAY NIGHT. A WARM FRONT WILL MOVE ACROSS THE AREA THURSDAY.
A WEAK COLD FRONT WILL MOVE IN FRIDAY AND THEN MOVE BACK NORTH AS
A WARM FRONT SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SATELLITE SHOWING THE CONTINUED CLEARING TREND ACROSS THE AREA.
TEMPS FALLING AS ANTICIPATED WITH DEWPOINTS IN THE LOWER 50S. SOME
MODELS CONTINUING TO INDICATE FOG DEVELOPING OVERNIGHT. SOME
MODELS SUCH AS THE HRRR NOT INDICATING WIDESPREAD FOG WHILE LATEST
LAMP GUIDANCE STILL SHOWING FOG ACROSS THE AREA. WITH RECENT
RAINFALL BEING MORE ISOLATED ACROSS THE AREA THERE ISN/T AN
ABUNDANT AMOUNT OF SFC MOISTURE TO AID FOR FOG DEVELOPMENT. ONLY
CHANGE TO FORECAST WAS THE REMOVAL OF THE TERM DENSE TO THE FOG
OVERNIGHT...BUT DID CONTINUE TO MENTION IT. AT THIS TIME WILL NOT
ISSUE ANY ADVISORIES GIVEN MARGINAL CONFIDENCE ON LOCATION AND
INTENSITY OF FOG ACROSS THE AREA. PREVIOUS DISCUSSION BELOW.
A HIGH PRESSURE RIDGE WILL BE MOVING INTO THE AREA TONIGHT. THE
BIG QUESTION IS HOW MUCH FOG WILL FORM. SOME OF THE MODELS ARE
INDICATING WIDESPREAD DENSE FOG DEVELOPING. ON THE EDGE ABOUT THAT
SINCE WE DID NOT HAVE WIDESPREAD RAIN AND DRIER AIR WILL DRY TO
MOVE IN...HOWEVER...WE WILL NOT HAVE MUCH SUNSHINE BEFORE SUNSET
OVER NORTHEAST OHIO AND NORTHWEST PA TO DRY THINGS OUT. WILL
MENTION AREAS OF DENSE FOG AND HAVE THE NEXT SHIFT MONITOR FOR A
POSSIBLE DENSE FOG ADVISORY. USED A MIX OF THE MOS GUIDANCE FOR
THE LOWS. THE NAM GUIDANCE SEEMS TOO WARM OVER NORTHWEST OHIO
BASED ON CLEARING SKIES AND LIGHT WINDS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
THE SHORT TERM WILL BE MAINLY DRY BUT THERE WILL BE A LOW THREAT OF
SHOWERS AND THUNDERSTORMS AT TIMES AND IN VARYING LOCATIONS.
THE RIDGE WILL BE OVER THE AREA ON WEDNESDAY WITH PARTLY TO MOSTLY
SUNNY SKIES. THE UPPER LOW OVER THE CAROLINAS MAY TRY TO MOVE SOME
SHOWERS AND THUNDERSTORMS TO NORTHEAST OH...BUT WILL KEEP IT DRY
ATTM. A WARM FRONT WILL MOVE ACROSS THE AREA THURSDAY...GOING WITH
SLIGHT CHANCE POPS AS CONFIDENCE IS LOW AND THEN SLIGHT CHANCE POPS
FRIDAY AND FRIDAY NIGHT AS WEAK COLD FRONT MOVES ACROSS THE AREA.
USED A MIX OF GUIDANCE FOR THE TEMPERATURES.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
NO CHANGES TO THE HOLIDAY WEEKEND FORECAST. FRONTAL BOUNDARY WILL BE
IN THE VICINITY SATURDAY...BUT WILL PUSH NORTH OF THE AREA BY
SUNDAY. MONDAY WE WILL BE SITTING HIGH AND DRY UNDER HIGH PRESSURE.
A COLD FRONT SLIPS THROUGH TUESDAY. H8 TEMPS PUSH +20C AND SURFACE
TEMPS WILL BE FLIRTING WITH 90...ESPECIALLY SUNDAY AND MONDAY.
SATURDAYS HIGHS MAY BE LIMITED SOME BY THE FRONT BEING NEARBY...BUT
STILL BE ABOVE NORMAL.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
CEILINGS AND VISIBILITIES ARE ON THEIR WAY DOWN AT THIS TIME FROM
CLEVELAND TO MANSFIELD EAST. I THINK WE WILL SEE A WIDESPREAD AREA
OF STRATUS AND FOG BY SUNRISE THIS MORNING. SO WILL MENTION THIS
ACCORDINGLY IN THE TAFS THIS MORNING. FOG AND STRATUS WILL BURN
OFF THIS MORNING AND GIVE WAY TO VFR AGAIN. LAKE BREEZE WILL
DEVELOP ALONG THE LAKE SHORE AT ERIE AND CLEVELAND. SOME FAIR
WEATHER CUMULUS WILL DEVELOP INLAND SOUTH OF THE LAKE BREEZE.
NOW THE OTHER PROBLEM WE HAVE TO CONTEND WITH IS WHETHER WE WILL
SEE A THREAT FOR AN ISOLATED SHOWER OR THUNDERSTORM DEVELOP SOUTH
OF THE LAKE BREEZE AND OVER EXTREME EASTERN PORTIONS OF THE
FORECAST AREA. WE THINK IT SHOULD BE SO ISOLATED THAT IT MAY NOT
AFFECT ANY TAF SITES. HOWEVER...AVIATION INTERESTS SHOULD KEEP IN
MIND THE POSSIBILITY THAT THERE MAY BE ONE OR TWO AROUND TO AFFECT
OPERATIONS. WINDS GO LIGHT AND VARIABLE AGAIN TONIGHT WITH
POSSIBILITY FOR SOME MVFR MIST.
.OUTLOOK...NON-VFR POSSIBLE IN MORNING BR/FG.
&&
.MARINE...
HIGH PRESSURE WILL BUILD OVER LAKE ERIE TONIGHT WITH LIGHT LAKE
BREEZES AND GOOD MARINE CONDITIONS EXPECTED ON WEDNESDAY. SOUTHERLY
FLOW WILL DEVELOP LATE THURSDAY INTO FRIDAY AHEAD OF A LOW PRESSURE
SYSTEM TRACKING NORTHEAST THROUGH THE WESTERN AND UPPER GREAT LAKES.
THIS SYSTEM WILL PUSH A WEAK FRONTAL BOUNDARY SOUTH TOWARDS LAKE
ERIE ON FRIDAY NIGHT...STALLING IN THE VICINITY OF THE LAKE ON
SATURDAY. LIGHT SOUTHERLY FLOW WILL DEVELOP AGAIN BY SUNDAY WITH
WELL ABOVE NORMAL TEMPERATURES AND STABLE CONDITIONS
EXPECTED FOR THE HOLIDAY WEEKEND.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...ABE/KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...OUDEMAN
AVIATION...LOMBARDY
MARINE...KEC
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1115 PM CDT TUE MAY 22 2012
.DISCUSSION.../ISSUED AT 900 PM CDT/
MAIN ISSUE OVER THE NEXT 18 HOURS IS THE CONVECTIVE CHANCES WITH THE
SURFACE COLD FRONT. CURRENTLY A BROKEN LINE OF CONVECTION EXTENDS
FROM NEAR ABERDEEN TO WINNER SOUTH DAKOTA. WHILE STORMS INITIALLY
DEVELOPED ALONG THE SURFACE FRONT...THE STRONG LOW LEVEL WINDS HAVE
RESULTED IN STORM MOTIONS THAT MOVE THEM AWAY FROM THE BOUNDARY. AS
A RESULT...UPDRAFTS CONTINUE TO WEAKEN ONCE THE STORMS MOVE INTO THE
MORE STABLE AIR MASS OVER SOUTHEAST SOUTH DAKOTA. WITH LITTLE UPPER
LEVEL FORCING FOR ASCENT IN THE NEXT HOUR OR TWO...SEVERE WEATHER
APPEARS UNLIKELY ALTHOUGH WITH 60 KT WINDS AT 850 MB...A SEVERE WIND
GUST OR QUARTER SIZE HAIL MAY STILL BE POSSIBLE.
EXPECTATION IS THESE STORMS WILL LIKELY SLOWLY WEAKEN OVER NEXT 3 OR
4 HOURS...ESPECIALLY SOUTH OF I-90 WHERE LOSS OF SURFACE HEATING
WILL ONLY STRENGTHEN CAP. HOWEVER...BOTH RAP AND NAM SHOW ANOTHER
WEAK WAVE WITH ASSOCIATED COOLING AT MID LEVELS MOVING INTO CENTRAL
SD AROUND 09Z. THESE MODELS ALONG WITH HRRR ALL PRODUCE MORE
CONVECTION AHEAD THE SURFACE COLD FRONT WHICH IS EXPECTED TO BE
BETWEEN 9V9 AND MHE. WITH THE COLD ADVECTION AND WEAK MIDLEVEL
ASCENT...THIS IS EXPECTED TO BE ENOUGH TO ERODE THE CAP AHEAD OF THE
LATER TONIGHT. AM A LITTLE CONCERNED THAT MODELS MAY BE OVERDOING
THE DEGREE OF COOLING ABOVE THE INVERSION AND CONVECTION WILL BE A
LITTLE LESS WIDESPREAD THAN MODELS ARE SHOWING...ESPECIALLY SOUTH OF
I90. BECAUSE THIS SECOND WAVE IS LATER IN THE NIGHT...HAVE SLOWED
THE PROGRESSION OF PRECIPITATION OVERNIGHT INTO WEDNESDAY MORNING
WITH THE BEST CHANCE FOR STORMS REMAINING OVER EAST CENTRAL SD
THROUGH 12Z AND THEN IN SW MN THROUGH 15Z OR 18Z. ALSO RAISED POPS
ALONG AND NORTH I90 LATE TONIGHT TO 30 TO 50 PERCENT RANGE.
FINALLY...HAVE INCREASED QPF OVERNIGHT TO AN AVERAGE OF 0.1 TO 0.2
ALONG HWY 14 ALTHOUGH LOCAL AMOUNTS APPROACHING 0.5 IN ARE POSSIBLE
WITH STORMS...AROUND BKX AND MML.
MADE FEW CHANGES TO TEMPERATURES OR WIND BUT DID INCREASE SKY COVER
THIS EVENING. LATEST GRID/ZFP AND PFM ALREADY ISSUED.
&&
.AVIATION.../FOR THE 05Z TAF ISSUANCE/
MAINLY VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. MODELS AND
AREA WIND PROFILERS CONTINUE TO SHOW 50-60KT LOW LEVEL JET ABOVE
1500FT AGL...LEADING TO CONCERNS OF LOW LEVEL WIND SHEAR. ALTHOUGH
WINDS REMAIN SOMEWHAT GUSTY AT THE SURFACE...WITH LOW LEVEL JET OF
THIS MAGNITUDE AND DIRECTION SLIGHTLY VEERED FROM DOMINANT SURFACE
WIND DIRECTION...WILL CONTINUE MENTION OF LLWS FOR ALL TAF LOCATIONS
TONIGHT...DIMINISHING WEST TO EAST AS WEAKENING GRADIENT WITH COLD
FRONT SHIFT EAST. ELEVATED THUNDERSTORMS WILL LIFT NORTHEAST ACROSS
THE KHON AREA/MIDDLE JAMES RIVER VALLEY EARLY IN THE TAF PERIOD...
WITH POTENTIAL FOR ADDITIONAL ELEVATED DEVELOPMENT AFTER 09Z AS MID
LEVEL WAVE MOVES INTO THE AREA FROM THE WEST. BEST CHANCE OF RAIN
SHOULD REMAIN NORTH OF I-90...AND LIKELIHOOD OF THUNDER ACTUALLY
IMPACTING TAF LOCATIONS IS LOW. HOWEVER DID ADD A POTENTIAL FOR
SHOWERS NEAR KHON/KFSD TAF LOCATIONS DURING 09Z-15Z TIME FRAME.
PRECIPITATION CHANCES INCREASE AGAIN LATE IN THE PERIOD ALONG AND
EAST OF I-29 CORRIDOR AS COLD FRONT PUSHES SLOWLY EAST. CAPPING
INVERSION AHEAD OF THE COLD FRONT COULD SUPPRESS CONVECTION UNTIL
AFTER 22Z-23Z...BUT CONFIDENCE IN DEVELOPMENT AFTER THAT TIME
INCREASES AND HAVE ADDED SHRA/TSRA TO KFSD/KSUX THROUGH WEDNESDAY
EVENING.
&&
.PREV DISCUSSION.../ISSUED AT 330 PM CDT/
STRONG SOUTHERLY FLOW CONTINUES ACROSS THE AREA AHEAD OF A COLD
FRONT THAT HAS PUSHED INTO FAR NORTHWEST CORNER OF SOUTH DAKOTA.
WITH GRADIENT CONTINUING TO STRENGTHEN ALOFT...WILL CONTINUE WIND
ADVISORY ACROSS THE AREA THROUGH THE EVENING HOURS AS THE FRONT
WORKS EAST THIS EVENING...COULD SEE THUNDERSTORMS DEVELOP BUT EXPECT
THE FOCUS TO BE FURTHER NORTH CLOSER TO THE MID LEVEL WAVE. AS
SUCH...HAVE NOT MADE MANY ADJUSTMENTS TO POPS WITH FOCUS MAINLY
NORTH OF I-90. WITH STOUT WINDS CONTINUING AHEAD OF THE
FRONT...KEPT FORECAST LOWS QUITE MILD CLOSER TO CONS RAW AND W MODEL.
BOUNDARY IS EXPECTED TO ENTER THE FORECAST AREA AFTER 06Z WEDNESDAY
AND SLOWLY PUSH EAST. NOT A LOT IN TERMS OF UPPER LEVEL SUPPORT
UNTIL WEDNESDAY EVENING AS UPPER WAVE LIFTS INTO THE REGION...AND
WEAK CAPPING INVERSION LOOKS TO HOLD FOR THE BETTER PART OF THE
DAY. KEPT CHANCE POPS GOING IN THE VICINITY OF THE FRONT THROUGH
THE DAY...BUT FOCUS WILL CERTAINLY BE WEDNESDAY NIGHT. HIGHS WILL
GENERALLY BE IN THE 70S TO LOWER 80S WITH 850 HPA TEMPS IN THE MID
TEENS.
CONTINUES TO LOOK LIKE A POTENTIAL HEAVY RAIN EVENT WEDNESDAY NIGHT
INTO EARLY THURSDAY MORNING AS FRONT STALLS ACROSS FAR SOUTHEAST CWA
WEDNESDAY NIGHT INTO THURSDAY MORNING WHILE WAVE EJECTS NORTHEAST OUT
OF NEBRASKA. INITIALLY COULD SEE SOME SEVERE WEATHER DURING THE
EVENING ACROSS NORTHWEST IOWA...BUT MAIN CONCERN WOULD BE THE HEAVY
RAINS. MODELS DO DIFFER ON PLACEMENT WITH GFS AND EC A LITTLE
FURTHER SOUTH THAN NAM/GEM. PREFER THE GFS/EC SOLUTION WITH BEST
CHANCE CLOSER TO FRONT WHERE DEEP MOISTURE WILL POOL AND WHERE
HIGHEST PWATS NEAR 1.50 INCHES EXPECTED. SO ACTIVITY THAT DEVELOPS
IN THE AFTERNOON SHOULD REALLY GET GOING WEDNESDAY EVENING AND
PERSIST THROUGH THE NIGHT WITH LOCAL RAINFALL AMOUNTS OVER 3 INCHES
LIKELY ESPECIALLY NEAR THE FRONT AND THEN DROPPING OFF DRAMATICALLY
ACROSS FAR NORTHWEST CWA. SO HIGHEST POPS WILL BE ACROSS SOUTHEAST
CWA WEDNESDAY NIGHT INTO THURSDAY MORNING...AND THEN A LINGERING
SMALLER CHANCE THURSDAY AFTERNOON IN EARLY EVENING. WILL HOLD OFF
ANY FLOOD WATCH FOR WEDNESDAY NIGHT...DUE TO UNCERTAINTY ON EXACT
LOCATION OF HEAVIEST RAIN...BUT WILL MENTION HEAVY RAIN IN GRIDS
ACROSS SOUTHEAST CWA AND ALSO MENTIONED IN HWO.
ON FRIDAY...BOUNDARY ACROSS SOUTHERN NEBRASKA AND SOUTHERN IOWA WILL
BEGIN TO LIFT SLOWLY NORTH FRIDAY NIGHT INTO SATURDAY...REACHING I90
ON SATURDAY. SO AS THIS FRONT LIFTS NORTH WOULD EXPECT AT LEAST
SCATTERED THUNDERSTORMS TO DEVELOP ON EDGE OF MID LEVEL CAP AS LOW
LEVEL JET INCREASES DURING THE NIGHT AND WAVE LIFTS NORTHEAST OUT OF
WESTERN NEBRASKA. COULD SEE ELEVATED SEVERE STORMS LATER IN THE
NIGHT AS THIS FRONT LIFTS NORTH.
WITH FRONT ALONG I90 ON SATURDAY...BEST CHANCE FOR THUNDERSTORMS
WILL CONTINUE NORTH OF I90 THROUGH SATURDAY...WITH POTENTIAL FOR
MORE HEAVY RAIN...THIS TIME ACROSS NORTHERN CWA SATURDAY NIGHT. WILL
HIGHLY DEPEND ON LOCATION OF MID LEVEL CAP AND FRONT AND HEAVIEST
RAIN COULD FALL NORTH OF CWA. SO WILL HAVE HIGHEST POPS ACROSS
NORTHERN CWA AND FAR SOUTHERN CWA MAY NOT SEE ANYTHING AFTER
CONVECTION LIFTS NORTH SATURDAY MORNING. VERY HIGH CAPES SOUTH OF
BOUNDARY IN CAPPED AIR OVER NORTHWEST IOWA...BUT DEFINATELY
SOMETHING TO WATCH NORTH OF BOUNDARY LATE SATURDAY AFTERNOON AND
EVENING FOR A ROUND OF SEVERE WEATHER.
AS WE HEAD INTO SUNDAY...COLD FRONT WILL PUSH EAST ACROSS CWA SUNDAY
AFTERNOON AND NIGHT WITH YET ANOTHER ROUND OF THUNDERSTORMS. IF MID
LEVEL CAP CAN BREAK AHEAD OF THIS FRONT WHICH GFS AND EC HINTING
AT...COULD SEE SOME SEVERE WEATHER IN THE AFTERNOON AND EVENING
ACROSS THE EASTERN CWA.
MEMORIAL DAY LOOKS TO BE QUIET AND DRY AND WILL CONTINUE THAT TREND
INTO TUESDAY.
TEMPERATURES WILL BE ON A ROLLER COASTER THURSDAY THROUGH
SUNDAY...WITH COOLER TEMPERATURES IN THE UPPER 60S TO MID 70S
THURSDAY AND FRIDAY AND THEN AS FRONT LIFTS NORTH...HIGHS ON
SATURDAY WILL LIKELY VARY FROM NEAR 70 ACROSS THE FAR NORTH TO NEAR
90 FAR SOUTHEAST. SHOULD BE WARMER ACROSS ALL OF CWA ON SUNDAY AHEAD
OF FRONT WITH HIGHS IN THE 80S...AND THEN COOLING BACK INTO 70S
MONDAY AND TUESDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1245 PM CDT WED MAY 23 2012
.SHORT TERM...
1101 AM CDT WED MAY 23 2012
LATEST 16Z METARS INDICATE WINDS HAVE INCREASED TO 15 TO 25 KNOTS
AND GUST UP TO 33 KNOTS ACROSS PARTS OF SOUTHEAST MINNESOTA AND
NORTHEAST IOWA. LATEST 23.14Z RAP BUFKIT SOUNDINGS INDICATE WINDS
WILL MIX DOWN FROM ALOFT AND A TIGHT PRESSURE GRADIENT OUT AHEAD
OF A COLD FRONT WILL ALLOW WINDS TO INCREASE TO 20 TO 30 MPH WITH
GUST UP TO 45 MPH LATE THIS MORNING AND AFTERNOON OVER PORTIONS OF
SOUTHEAST MINNESOTA AND NORTHEAST IOWA. THEREFORE...HAVE ISSUED A
WIND ADVISORY FOR PARTS OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA.
.LONG TERM...SATURDAY THROUGH TUESDAY
344 AM CDT WED MAY 23 2012
MODEL CONSENSUS CONTINUES TO TIGHTEN/IMPROVE THROUGH THE HOLIDAY
WEEKEND PERIOD...WITH SAT-TUE FCST CONFIDENCE NOW AVERAGE OR A BIT
BETTER. PERSISTENT SOUTH FLOW AHEAD OF THE LEE TROUGH/LOW IN THE
PLAINS PUSHES THE WARM FRONT NORTH ACROSS THE AREA SAT/SUN. THIS AS
THE LEE LOW EVENTUALLY LIFTS INTO THE NORTHERN PLAINS AND THE
MID LEVEL TROUGH SLOWLY EJECTS TOWARD THE NORTHERN PLAINS.
CONVECTION EXPECTED TO BE ONGOING NORTH OF THE FRONTAL BOUNDARY
SAT...SOMEWHERE ACROSS WI/SOUTHERN MN/NORTHERN IA. THIS CONVECTION
HAS POTENTIAL TO STALL THE FRONT/S NORTHWARD PROGRESS ON SAT. ANY
BREAKS IN CONVECTION SAT/SAT NIGHT SHOULD ALLOW THE FRONT TO LIFT
NORTH OF THE FCST AREA BY OR ON SUNDAY. AGAIN BETTER MODEL SIGNAL
FOR THIS TO OCCUR...WITH SUNDAY A VERY WARM/SUMMERY DAY WITH SMALL
IF ANY RAIN CHANCES WITH A CAPPED...WARM SECTOR AIRMASS OVER THE
AREA. MID LEVEL TROUGH LIFTING ACROSS THE NORTHERN PLAINS INTO SOUTH
CAN MON/TUE SENDS A COLD FRONT ACROSS THE AREA ON MON. THIS INTO
WHAT SHOULD BE A RATHER MOIST/UNSTABLE AIRMASS OVER THE REGION. SOME
TIMING/STRENGTH DIFFERENCES BY MON...SHRA/TSRA CHANCES FROM SUN
NIGHT THRU MON NIGHT VERY REASONABLE. MODEL/ENSEMBLE CONSENSUS DATA
IN THE DAY 4-7 FCST GRIDS DEPICT THIS QUITE WELL WITH ONLY MINOR
ADJUSTMENTS MADE TO BLEND WITH NEIGHBORING GRIDS.
&&
.AVIATION...THROUGH 18Z THURSDAY
1244 PM CDT WED MAY 23 2012
A LOW PRESSURE SYSTEM OVER THE CENTRAL HIGH PLAINS WILL PUSH
NORTHEAST INTO NORTHERN IOWA BY 18Z THURSDAY. OUT AHEAD OF THE LOW
PRESSURE SYSTEM...THE COMBINATION OF WINDS MIXING DOWN ALOFT AND A
TIGHTENING PRESSURE GRADIENT WILL CREATE WINDY
CONDITIONS...ESPECIALLY WEST OF THE MISSISSIPPI RIVER. SOUTHERLY
WINDS WILL BE SUSTAINED AT 25 KNOTS WITH GUSTS UP TO 38 KNOTS CAN
AT RST AND LSE WILL BE SUSTAINED AT 18 KNOTS AND GUST UP TO 27
KNOTS THROUGH 02Z THURSDAY. NEXT CONCERN ARE PRECIPITATION CHANCES
AT BOTH TAF SITES. LATEST 23.12Z DETERMINISTIC MODELS INDICATE
BEST MOISTURE CONVERGENCE AND LIFT ASSOCIATED WITH LOW PRESSURE
SYSTEM WILL BE WEST OF THE TAF SITES. HOWEVER...MODELS DO INDICATE
THE POSSIBILITY OF SHOWERS AND PERHAPS A THUNDERSTORM TO MOVE INTO
THE RST TAF SITE AFTER 05Z THURSDAY AND 10Z THURSDAY AT LSE. VFR
CONDITIONS SHOULD PREVAIL AT BOTH TAF SITES THROUGH THE PERIOD.
THE DETERMINISTIC MODELS DO SUGGEST IF A THUNDERSTORM OR STRONG
SHOWER SHOULD DROP CEILINGS INTO THE MVFR/IFR RANGE. WITH
CONFIDENCE LOW FOR THIS OCCURRING HAVE LEFT VFR CONDITIONS TO
PREVAIL. LOW LEVEL WIND SHEAR IS POSSIBLE OVER THE TAF SITES AFTER
09Z THURSDAY...AT THIS TIME WILL LET LATER SHIFTS DIAGNOSE OF
OCCURRING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1101 AM CDT WED MAY 23 2012
WI...NONE.
MN...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MNZ086-087-094-095.
IA...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR IAZ008-009-018-019.
&&
$$
SHORT TERM...DTJ
LONG TERM....RRS
AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1108 AM CDT WED MAY 23 2012
.SHORT TERM...
1101 AM CDT WED MAY 23 2012
LATEST 16Z METARS INDICATE WINDS HAVE INCREASED TO 15 TO 25 KNOTS
AND GUST UP TO 33 KNOTS ACROSS PARTS OF SOUTHEAST MINNESOTA AND
NORTHEAST IOWA. LATEST 23.14Z RAP BUFKIT SOUNDINGS INDICATE WINDS
WILL MIX DOWN FROM ALOFT AND A TIGHT PRESSURE GRADIENT OUT AHEAD
OF A COLD FRONT WILL ALLOW WINDS TO INCREASE TO 20 TO 30 MPH WITH
GUST UP TO 45 MPH LATE THIS MORNING AND AFTERNOON OVER PORTIONS OF
SOUTHEAST MINNESOTA AND NORTHEAST IOWA. THEREFORE...HAVE ISSUED A
WIND ADVISORY FOR PARTS OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA.
.LONG TERM...SATURDAY THROUGH TUESDAY
344 AM CDT WED MAY 23 2012
MODEL CONSENSUS CONTINUES TO TIGHTEN/IMPROVE THROUGH THE HOLIDAY
WEEKEND PERIOD...WITH SAT-TUE FCST CONFIDENCE NOW AVERAGE OR A BIT
BETTER. PERSISTENT SOUTH FLOW AHEAD OF THE LEE TROUGH/LOW IN THE
PLAINS PUSHES THE WARM FRONT NORTH ACROSS THE AREA SAT/SUN. THIS AS
THE LEE LOW EVENTUALLY LIFTS INTO THE NORTHERN PLAINS AND THE
MID LEVEL TROUGH SLOWLY EJECTS TOWARD THE NORTHERN PLAINS.
CONVECTION EXPECTED TO BE ONGOING NORTH OF THE FRONTAL BOUNDARY
SAT...SOMEWHERE ACROSS WI/SOUTHERN MN/NORTHERN IA. THIS CONVECTION
HAS POTENTIAL TO STALL THE FRONT/S NORTHWARD PROGRESS ON SAT. ANY
BREAKS IN CONVECTION SAT/SAT NIGHT SHOULD ALLOW THE FRONT TO LIFT
NORTH OF THE FCST AREA BY OR ON SUNDAY. AGAIN BETTER MODEL SIGNAL
FOR THIS TO OCCUR...WITH SUNDAY A VERY WARM/SUMMERY DAY WITH SMALL
IF ANY RAIN CHANCES WITH A CAPPED...WARM SECTOR AIRMASS OVER THE
AREA. MID LEVEL TROUGH LIFTING ACROSS THE NORTHERN PLAINS INTO SOUTH
CAN MON/TUE SENDS A COLD FRONT ACROSS THE AREA ON MON. THIS INTO
WHAT SHOULD BE A RATHER MOIST/UNSTABLE AIRMASS OVER THE REGION. SOME
TIMING/STRENGTH DIFFERENCES BY MON...SHRA/TSRA CHANCES FROM SUN
NIGHT THRU MON NIGHT VERY REASONABLE. MODEL/ENSEMBLE CONSENSUS DATA
IN THE DAY 4-7 FCST GRIDS DEPICT THIS QUITE WELL WITH ONLY MINOR
ADJUSTMENTS MADE TO BLEND WITH NEIGHBORING GRIDS.
&&
.AVIATION...TODAY AND TONIGHT
626 AM CDT WED MAY 23 2012
WINDY CONDITIONS ON TAP FOR THE TAF SITES TODAY DUE TO A
TIGHTENING PRESSURE GRADIENT AHEAD OF A LOW PRESSURE SYSTEM AND
COLD FRONT MOVING ACROSS THE DAKOTAS INTO WESTERN MINNESOTA TODAY.
SUSTAINED SOUTHERLY WINDS WILL BE AROUND 18 TO 24KT AT RST TODAY
AND BETWEEN 12 TO 18KT AT LSE. GUSTS WILL TOP OUT IN THE 28 TO
35KT RANGE THIS AFTERNOON DURING PEAK HEATING. SHOWERS AND
THUNDERSTORMS WILL MOVE IN FROM THE WEST TONIGHT AND MAY GET INTO
RST AROUND MIDNIGHT OR SHORTLY AFTER. THE PROGRESSION EASTWARD
INTO LSE BY 12Z TOMORROW MORNING IS A LITTLE LESS LIKELY...BUT
POSSIBLE. CONDITIONS WILL MAINLY BE VFR...BUT IF STORMS DO MAKE IT
INTO RST OR LSE THEN THEY MAY DROP TO MVFR/IFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1101 AM CDT WED MAY 23 2012
WI...NONE.
MN...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MNZ086-087-094-095.
IA...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR IAZ008-009-018-019.
&&
$$
SHORT TERM...DTJ
LONG TERM....RRS
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
344 AM CDT WED MAY 23 2012
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
344 AM CDT WED MAY 23 2012
MAIN FORECAST CONCERNS THIS PACKAGE...WINDS TODAY/THU...SHRA/TSRA
CHANCES TONIGHT THRU FRI NIGHT...SEVERE STORM POTENTIAL THU
AFTERNOON/EVENING...TEMPERATURES.
DATA ANALYSIS AT 06Z HAD HIGH PRESSURE OVER MI AND OH VALLEY AND LOW
PRESSURE FROM SOUTH OF LK WINNIPEG TO EASTERN CO. TIGHT PRESSURE
GRADIENT AHEAD OF THE LOW WAS OVER MN/WESTERN IA WITH SOUTH/
SOUTHEAST WINDS 20KTS G30KTS OVER MUCH OF THIS AREA. STRONG MOISTURE
TRANSPORT AND THETA-E CONVERGENCE CENTERED ON 850MB AHEAD OF THE
SFC-850MB TROUGH PRODUCING WIDESPREAD SHRA/TSRA FROM NORTHWEST MN TO
EASTERN SD...ALL LIFTING STEADILY NORTHEAST. HIGH LEVEL DEBRIS
CLOUDS FROM THE CONVECTION SPILLING SOUTHEAST ACROSS MN/IA/WI. THIS
PLUS THE INCREASING SOUTH/SOUTHEAST GRADIENT WINDS KEEPING TEMPS
ACROSS THE AREA SOME 10-15F WARMER THAN LAST NIGHT AT THIS TIME.
23.00Z MODELS LOOK TO HAVE INITIALIZED WELL...BUT FOR GFS SOME 5F TO
15F TOO HIGH WITH SFC DEWPOINTS OVER THE NORTHERN PLAINS/WESTERN
GREAT LAKE REGIONS. SOLUTIONS QUITE SIMILAR THRU FRI THEN DIVERGE
WITH NORTHWARD RETURN OF THE FRONTAL BOUNDARY FRI NIGHT. DPROG/DT OF
500MB HGTS AT 23.00Z SHOWED MODEL RUNS OF 21.00Z AND 22.00Z VERIFIED
WELL ACROSS NOAM/EASTERN PAC WITH BETTER RUN-TO-RUN CONSISTENCY
AGAIN TO ECMWF. THRU TODAY/TONIGHT MODELS CONVERGING ON A TIGHTER
COMPROMISE OF THE EARLIER RUNS...BUT FAVOR SLOWER OF EARLIER RUNS
WITH THE ENERGY/TROUGHING MOVING ACROSS THE NORTHERN ROCKIES/
PLAINS. BETTER/TIGHTER CONSENSUS SOLUTION AS THIS TROUGH/ENERGY
LIFTS ACROSS THE WESTERN GREAT LAKES THU/THU NIGHT. BETTER RUN-TO-
RUN CONSISTENCY BY THU NIGHT TO GFS. CONSENSUS CONTINUED TO IMPROVE
FRI/FRI NIGHT AS TROUGHING DEEPENS OVER THE WESTERN CONUS AND DOWN
STREAM HGTS RISE OVER THE NORTHERN PLAINS/UPPER MIDWEST. BETTER
CONSISTENCY BY SAT MORNING BACK TO ECMWF. CHECK OF OBS VS. MODEL
DATA AT 06Z SHOWED MODELS GENERALLY GOOD WITH THE SFC MASS FIELDS
OVER THE CENTRAL CONUS BUT GFS REMAINED A BIT HIGH WITH ITS SFC DEW
POINTS IN THE PLUME AHEAD OF THE LOW/TROUGH. PER WV IMAGERY ALL
LOOKED COMPARABLE WITH THE SHORTWAVE DETAILS OVER NOAM/EASTERN PAC.
MOST MODELS LOOK TOO LIGHT WITH THE 00-06Z PRECIP FROM NORTHWEST
MN TO EASTERN SD. WETTER GFS LOOKED BEST WITH THIS. WITH THE STRONG
TREND TOWARD A TIGHTER CONSENSUS SOLUTION TODAY THRU FRI NIGHT AND
NO CLEAR MODEL FAVORITE...FAVORED THE MODEL/ENSEMBLE CONSENSUS.
SHORT TERM FCST CONFIDENCE AVERAGE TO GOOD THIS CYCLE.
IN THE SHORT TERM...FIRST ISSUE IS STRONGER WINDS THIS AND THU
AFTERNOONS. WINDS ACROSS THE WEST END OF THE FCST AREA MAY APPROACH
WIND ADVISORY CRITERIA FOR A BRIEF TIME THIS AFTERNOON. GRADIENT
CONTINUES TO TIGHTEN OVER THE AREA WITH MOST GUIDANCE INDICATING
SUSTAINED SPEEDS OF 20-25KTS THIS AFTERNOON. SOUNDINGS SHOWING A
SHALLOWER MIXING DEPTH TODAY...TO 900-875MB MUCH OF THE AFTERNOON...
WITH AROUND 35KTS AT THE TOP OF THE MIXED LAYER. WILL HOLD OFF ON
ANY WIND ADVISORY FOR NOW BUT WILL BRIEF DAY CREW TO KEEP AN EYE ON
IT. SAME THING GOES FOR THU AFTERNOON OVER THE SOUTHEAST 1/3 OF THE
FCST AREA WITH TIGHTEST GRADIENT AHEAD OF THE TROUGH SHIFTED EAST.
SOUNDINGS AGAIN SHOW MIXING TO 900-875MB WITH ABOUT 35KT ON TOP OF
THE MIXED LAYER.
SLIGHT SLOWING TREND OF MODELS KEEPS MOISTURE AXIS AND STRONGER OF
LOWER LEVEL MOISTURE TRANSPORT/THERMODYNAMIC FORCING WEST OF THE
FCST AREA TODAY. KEPT ENTIRE FCST AREA DRY TODAY. THIS MOISTURE/
FORCING/LIFT SLOWLY TRANSLATES EAST TONIGHT...BUT PLENTY OF MID
LEVEL WARM AIR AND CAPPING/CIN TO INHIBIT CONVECTION UNTIL THE MID
LEVELS COOL WITH APPROACH OF THE TROUGH/SHORTWAVE AND DEEP
SATURATION OF THE COLUMN OCCURS. CONTINUED A RATHER TIGHT GRADIENT
OF SHRA/TSRA CHANCES FROM NORTHWEST TO SOUTHEAST ACROSS THE FCST
AREA TONIGHT. MID LEVEL TROUGH/SHORTWAVE MOVES ACROSS THE AREA
THU...ALONG WITH THE SFC-850MB TROUGH/MOISTURE AXIS AND MDT/STRONG
SFC-850MB FN CONVERGENCE. MODEL SOUNDINGS INDICATE ANY REMAINING
CAPPING ACROSS THE AREA ERODES DURING THE AFTERNOON. QUESTION
REMAINS HOW MUCH CAPE CAN BUILD AHEAD OF THE SFC FRONT/TROUGH AXIS
AS IT MOVES ACROSS THE AREA ON THU. ONGOING CONVECTION JUST WEST/
NORTH OF THE FCST AREA EARLY THU AND DEBRIS CLOUDS MAY LIMIT WARMING
ON THU...AND MAY BE WHY SOME MODELS ONLY DEVELOP 500-1000 J/KG OF ML
CAPE AHEAD OF THE SFC TROUGH. DEEPER LIFT/DIVERGENCE ALOFT AND LOW
PRESSURE LIFTING NORTHEAST ALONG THE TROUGH/FRONT MAY BE ABLE TO
COMPENSATE FOR THE WEAKER CAPE SIGNAL. BASED ON TIMING OF THE
LOW/FRONT AND STRONGER FORCING/LIFT MOVING ACROSS THE AREA...SWODY2
LOOKS GOOD. WITH THE TIGHTER MODEL CONSENSUS...RAISED SHRA/TSRA
CHANCES INTO THE 60-80 PERCENT RANGE FOR MUCH OF THE AREA BY THU
AFTERNOON/EVENING WITH THE TROUGH PASSAGE. WITH THE FRONT WELL EAST
OF THE AREA BY 06Z FRI AND DRIER AIR/WEAK HIGH PRESSURE BUILDING
IN...CONTINUED OR TRENDED LATER THU NIGHT/FRI TOWARD A DRY PERIOD.
WITH TROUGHING DEEPENING OVER THE ROCKIES FRI/FRI NIGHT...LEE
TROUGHING STRENGTHENS IN THE CENTRAL PLAINS AND BEGINS TO RETURN THE
FRONT BACK NORTH AS A WARM FRONT FRI NIGHT. 925-700MB MOISTURE
TRANSPORT/THETA-E CONVERGENCE INTO AND OVER THE FRONTAL BOUNDARY
INCREASES AS THE LOWER LEVEL FLOW AHEAD OF THE LEE TROUGH
STRENGTHENS AND BECOMES MORE SOUTH/SOUTHWESTERLY. PW VALUES IN THE
AIRMASS TO BE ADVECTED INTO/OVER THE FRONT IN THE 1 TO 1.5 INCH
RANGE. BY THIS TIME...MODELS DO DIFFER ON HOW QUICKLY THE FRONT
LIFTS NORTH...AND WHERE SOME OF THE STRONGER MOISTURE TRANSPORT/
THETA-E CONVERGENCE IS EXPECTED TO OCCUR. GIVEN THE TIGHTER MODEL
CONSENSUS AND OVERALL SYNOPTIC SET-UP...RAISED SHRA/TSRA CHANCES
FOR FRI NIGHT INTO THE 30-60 PERCENT RANGE...HIGHEST OVER THE
SOUTHEAST HALF OF THE FCST AREA CLOSER TO THE FRONT. WITH THE FRONT
SOUTH OF THE AREA FRI NIGHT...TSRA WILL BE FORCED WELL ABOVE THE
BOUNDARY LAYER WITH LIGHTENING...HEAVY RAINS AND POSSIBLE HAIL THE
MAIN THREATS.
OVERALL FAVORED A BLEND OF THE GUIDANCE TEMPERATURES FOR HIGHS/LOWS
TODAY THRU FRI NIGHT. HIGH TEMPS REMAIN TRICKY BOTH TODAY AND THU.
POTENTIAL FOR CIRRUS DEBRIS CLOUDS TO HOLD TEMPS DOWN A BIT TODAY.
IF SHRA/TSRA DEVELOP/ARRIVE EARLIER RATHER THAN LATER ON THU...
HIGHS IN FCST GRIDS FOR THU MAY ALSO BE TOO WARM.
.LONG TERM...SATURDAY THROUGH TUESDAY
344 AM CDT WED MAY 23 2012
MODEL CONSENSUS CONTINUES TO TIGHTEN/IMPROVE THROUGH THE HOLIDAY
WEEKEND PERIOD...WITH SAT-TUE FCST CONFIDENCE NOW AVERAGE OR A BIT
BETTER. PERSISTENT SOUTH FLOW AHEAD OF THE LEE TROUGH/LOW IN THE
PLAINS PUSHES THE WARM FRONT NORTH ACROSS THE AREA SAT/SUN. THIS AS
THE LEE LOW EVENTUALLY LIFTS INTO THE NORTHERN PLAINS AND THE
MID LEVEL TROUGH SLOWLY EJECTS TOWARD THE NORTHERN PLAINS.
CONVECTION EXPECTED TO BE ONGOING NORTH OF THE FRONTAL BOUNDARY
SAT...SOMEWHERE ACROSS WI/SOUTHERN MN/NORTHERN IA. THIS CONVECTION
HAS POTENTIAL TO STALL THE FRONT/S NORTHWARD PROGRESS ON SAT. ANY
BREAKS IN CONVECTION SAT/SAT NIGHT SHOULD ALLOW THE FRONT TO LIFT
NORTH OF THE FCST AREA BY OR ON SUNDAY. AGAIN BETTER MODEL SIGNAL
FOR THIS TO OCCUR...WITH SUNDAY A VERY WARM/SUMMERY DAY WITH SMALL
IF ANY RAIN CHANCES WITH A CAPPED...WARM SECTOR AIRMASS OVER THE
AREA. MID LEVEL TROUGH LIFTING ACROSS THE NORTHERN PLAINS INTO SOUTH
CAN MON/TUE SENDS A COLD FRONT ACROSS THE AREA ON MON. THIS INTO
WHAT SHOULD BE A RATHER MOIST/UNSTABLE AIRMASS OVER THE REGION. SOME
TIMING/STRENGTH DIFFERENCES BY MON...SHRA/TSRA CHANCES FROM SUN
NIGHT THRU MON NIGHT VERY REASONABLE. MODEL/ENSEMBLE CONSENSUS DATA
IN THE DAY 4-7 FCST GRIDS DEPICT THIS QUITE WELL WITH ONLY MINOR
ADJUSTMENTS MADE TO BLEND WITH NEIGHBORING GRIDS.
&&
.AVIATION...THROUGH WEDNESDAY NIGHT
1115 PM CDT TUE MAY 22 2012
LATEST RAP AND NAM12 BUFKIT SOUNDINGS BACKING OFF ON THE WINDS IN
THE LOW LEVELS JUST A BIT. THE WINDS WILL STILL STAY UP
OVERNIGHT...BUT THE LLWS RISK LOOKS LOWER THAN PREVIOUSLY INDICATED.
WILL REMOVE FROM KRST FOR NOW. 2 KFT WINDS SHOULD STILL BE NEAR 45
KTS FROM ABOUT 190.
WINDS GO FROM SOUTH TO SOUTHWEST ALOFT...NOT OVERLY UNI-DIRECTIONAL.
STILL...WITH SOME HIGH CLOUDS SPREADING IN FROM THE WEST...
THERE SHOULD BE ENOUGH MIXING TO LEAD TO HIGHER GUSTS...STARTING BY
EARLY MORNING...CONTINUING INTO THE AFTERNOON.
MODELS TRENDS HAVE BEEN SLOWING THE FRONT DOWN...AND ITS NOW PROGGED
TO MOVE OVER THE LOCAL AREA ON THU. LOOK FOR INCREASING...
THICKENING...AND LOWERING CIGS LATER WED NIGHT AS A RESULT.
HOWEVER...THE SHRA/TS THREAT WILL LIKELY HOLD OFF UNTIL AFTER 12Z
THU...AND PERHAPS CLOSER TO 21Z FOR KLSE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
344 AM CDT WED MAY 23 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS DENVER CO
1055 PM MDT THU MAY 24 2012
.UPDATE...A NARROW BAND OF SHOWERS/STORMS CONTINUES ACROSS PALMER
DIVIDE AND LINCOLN COUNTY AREA LATE THIS EVENING. LATEST SHORT
RANGE TRENDS INCLUDING SATELLITE IMAGERY SHOW ANOTHER BAND OF
CLOUDINESS AND COOLER CLOUD TOPS DEVELOPING OVER WESTERN COLORADO.
THIS TRAJECTORY TAKES MOST OF THIS ALONG AND JUST NORTH OF THE
I-70 CORRIDOR LATER TONIGHT. OVERALL THIS LEADS TO HIGHER
CONFIDENCE IN THE SHORT RANGE MODEL GUIDANCE SUGGESTING ANOTHER
BATCH OF CONVECTION DEVELOPING SHORTLY AFTER MIDNIGHT AND
SPREADING NORTHWARD. AREAS CLOSER TO THE WYOMING AND NEBRASKA
BORDERS WOULD SEE THE HIGHEST CHANCE. HAVE ADDED A LITTLE THUNDER
TO THE OVERNIGHT FORECAST.
&&
.AVIATION...THERE SEEMS TO BE A SMALL WINDOW BETWEEN 06Z AND 09Z
FOR POSSIBLE CONVECTION. THIS IS ONLY A SLIGHT CHANCE OF
SHOWERS/STORMS. OTHERWISE NO SIGNIFICANT CHANGES SEEN.
&&
.PREV DISCUSSION... /ISSUED 737 PM MDT THU MAY 24 2012/
UPDATE...RADAR SHOWING A BOUNDARY MOVING WEST ACROSS EASTERN
COLORADO. THIS IS INCREASING LOW LEVEL MOISTURE...BUT NOT DOING
MUCH TO TEMPERATURES. THE INCREASE IN MOISTURE COMBINED WITH
INCREASING LIFT HAS PRODUCED A FEW SHOWERS OVER THE EASTERN
PLAINS. WILL HAVE LOW POPS FOR MOST OF THE EASTERN PLAINS FOR
THIS. HRRR SUPPORTS THIS AS IT SHOWS ISOLATED SHOWERS THIS
EVENING. BETTER CHANCE FOR SHOWERS WILL BE OVERNIGHT IN THE FAR
NORTHEAST CORNER OF THE STATE WHERE THE BEST MOISTURE AND LIFT
WILL BE. ADJUSTED FORECAST TO INCREASE POPS FOR THIS AND ALSO
TWEAKED THE FORECAST TO REFLECT CURRENT CONDITIONS.
AVIATION...EASTERLY WINDS WILL PREVAIL TONIGHT AND MOST OF FRIDAY
ACROSS THE DENVER AREA. WINDS MAY CYCLONE AND TURN NORTHERLY ALONG
THE FOOTHILLS. LOW CLOUDS WILL FORM 07-09Z WITH CEILINGS 2500 TO
4000 FEET. LOW CLOUDS WITH CEILINGS BELOW 6000 MAY PREVAIL THROUGH
THE DAY FRIDAY.
PREV DISCUSSION... /ISSUED 245 PM MDT THU MAY 24 2012/
SHORT TERM...CURRENT RADAR PICTURES ARE SHOWING A BATCH OF SHOWERS
OVER NORTHERN WELD AND LOGAN COUNTIES. THESE SHOWERS ARE LIKELY
ASSOCIATED WITH THE JET MAXIMUM NOW OVER THE NORTHERN BORDER OF
COLORADO. THE SHOWERS ALONG THE CONTINENTAL DIVIDE ARE CONTINUING
AS WELL. MODELS SHOW THE JET MAXIMUM TO BE OVER SOUTHERN WYOMING AT
06Z TONIGHT. THE FLOW ALOFT OVER THE FORECAST AREA IS PROGGED TO BE
SOUTHWESTERLY ON FRIDAY WITH SPEEDS IN THE 70 TO 90 KNOT RANGE.
BOTH THE NAM AND GFS SHOW WEAK UPWARD QG VERTICAL VELOCITY FOR THE
CWA OVERNIGHT AND FRIDAY. THE LOW LEVEL PRESSURE AND WIND FIELDS
SHOW A SURGE OF UPSLOPE TO MOVE INTO THE PLAINS THIS EVENING. ON
FRIDAY...THE NAM HAS EASTERLY BOUNDARY LAYER FLOW ACROSS THE PLAINS
AND FOOTHILLS...WITH SOUTHEASTERLIES ON THE GFS. FOR MOISTURE...THE
NAM SHOWS QUITE A BIT DEVELOPING OVER THE PLAINS OVERNIGHT...THE GFS
SHOWS LESS. THAT LOW LEVEL MOISTURE STICKS AROUND ON THE NAM FOR
FRIDAY...THE GFS IS DRIER ON FRIDAY. DEW POINTS ARE PROGGED IN THE
MID 30S TO LOWER 40S FOR THE PLAINS OVERNIGHT...WITH 40S...EVEN
LOWER 50S F ON FRIDAY. THERE IS NO CAPE PROGGED FOR THE CWA
TONIGHT. BY FRIDAY AFTERNOON...THERE IS SOME OVER THE PLAINS...MORE
SO ON THE GFS. THE NAM LAPSE RATE FIELDS HAVE A STRONG LOW/MID
LEVEL STABLE LAYER OVER THE PLAINS ON FRIDAY...THE GFS HAS PRETTY
STEEP LAPSE RATES DURING THIS SAME TIME. THE QPF FIELDS HAVE A TAD
OF MEASURABLE PRECIPITATION OVER THE NORTHERN AND EASTERN BORDER
THIS EVENING...THEN A BIT MORE OVER THE NORTH HALF OF THE CWA
OVERNIGHT. ON FRIDAY...THERE IS A TAD OVER NORTHERN AND EASTERN
BORDER AGAIN. SO THE GFS AND NAM DIFFER SIGNIFICANTLY CONCERNING
THE COLD AIR SURGE...UPSLOPE...MOISTURE AND INSTABILITY. I BELIEVE A
BIT MORE IN THE NAM IN THAT IF A SURGE MOVES IN...IT USUALLY MAKES
IT TO THE FOOTHILLS ANYWAY. FOR POPS...WILL GO WITH 20-40%S
OVERNIGHT...MAINLY OVER THE NORTHERN AND EASTERN BORDER AREAS. ON
FRIDAY...WILL GO WITH 10-20%S FOR THE PLAINS AND FOOTHILLS. IT MAY
BE TO STABLE FOR STORMS HOWEVER. FOR TEMPERATURES...FRIDAY`S HIGHS
ON THE NAM ARE SIMILAR TO TODAY`S WITH THE NORTHEAST CORNER BEING
COLDER. THE GFS SHOWS A 5-10 C WARM-UP FROM TODAY`S. AGAIN...WILL
LEAN MORE TOWARDS THE NAM.
LONG TERM...FOR FRIDAY EVENING...FLOW ALOFT TO BECOME SOUTH
SOUTHWEST AS UPPER TROUGH DIGS INTO GREAT BASIN. SOME WEAK LIFT
PROGGED OVER REGION...ENOUGH TO MAINTAIN A SLIGHT CHANCE OF
THUNDERSTORMS WITH THE BEST CHANCE NEAR THE WYOMING BORDER. BOTH NAM
AND GFS CONTINUE TO SHOW SURFACE HIGH OVER CENTRAL PLAINS ADVECTING
LOW LEVEL MOISTURE WESTWARD TOWARD THE FOOTHILLS AFTER MIDNIGHT.
BOTH BOUNDARY LAYER PROGS SHOW POTENTIAL FOR STRATUS AND AREAS OF
FOG ACROSS MUCH OF THE PLAINS OVERNIGHT. THIS ALREADY IN GRIDS AND
LOOKS REASONABLE. AIRMASS LOOKS A BIT TOO STABLE FOR THUNDER IN THE
OVERNIGHT HOURS SO OPT TO DROP FROM GRIDS. SOUTHERLY SURFACE WINDS
WILL BE ON THE INCREASE SATURDAY AS FLOW ALOFT CONTINUES TO INCREASE
WITH JET EXPECTED TO PASS OVERHEAD. COULD SEE SOME GUSTS UP TO 50
MPH ACROSS PLAINS DURING THE AFTERNOON AND EARLY EVENING. FLOW TO
USHER IN WARMER AND DRIER AIR INTO THE REGION...AND COMBINING WITH
THE GUSTY WINDS...WILL ELEVATE THE FIRE DANGER ONCE AGAIN WITH
CRITICAL FIRE WEATHER CONDITIONS POSSIBLE. IT APPEARS THAT THE
RECENT BENEFICIAL PRECIPITATION HELPED INCREASED THE FUEL MOISTURES.
FOR NOW WILL BE HOLDING OFF ON ANY FIRE WEATHER HILITES. MODELS SHOW
SOME MOISTURE ALONG WITH WEAK QG ASCENT SLIDING ACROSS MOUNTAINS...
WILL KEEP A SLIGHT CHANCE OF CONVECTION THERE. AIRMASS LOOKS TOO DRY
FOR CONVECTION ACROSS PLAINS. FLOW ALOFT TO WEAKEN SATURDAY EVENING
AS UPPER TROUGH OVER GREAT BASIN BEGINS TO HEAD INTO WYOMING. SHOULD
SEE SURFACE WINDS DECREASE AS A RESULT.THERE IS SOME INCREASE IN MID
LEVEL QG ASCENT...THOUGH MOST TO REMAIN WEST AND NORTH OF THE AREA.
WILL KEEP SOME SHOWERS GOING OVER THE MOUNTAINS OVERNIGHT. LOOKS
COLD ENOUGH FOR SOME SOME OVER THE RIDGES. THE UPPER LOW TO CONTINUE
MOVING NORTHEAST INTO WYOMING SUNDAY WITH BASE OF TROUGH AFFECTING
NORTHERN COLORADO. MODELS SHOW ASSOCIATED SURFACE FRONT PUSHING
ACROSS REGION WITH COOLER AIR ALONG WITH A BIT MORE MOISTURE. BOTH
NAM AND GFS DEPICT MID LEVEL QG ASCENT OVER AREA DURING THE
MORNING...FOLLOWED QUICKLY BY SUBSIDENCE DURING THE AFTERNOON.
APPEARS BEST CHANCE FOR SHOWERS AND STORMS WILL BE IN THE HIGH
COUNTRY DURING THE MORNING...BUT WILL CONTINUE THROUGH THE DAY. WILL
MAINTAIN A DRY FORECAST FOR THE PLAINS.
ZONAL FLOW ALOFT TO PREVAIL MONDAY AND TUESDAY...WITH NEAR NORMAL
TEMPERATURES AND MAINLY DRY WEATHER. BOTH GFS AND ECMWF CONTINUE TO
SHOW FLOW ALOFT BECOMING NORTHWEST WEDNESDAY WITH UPPER TROUGH
DIGGING INTO THE CENTRAL PLAINS. BOTH MODELS ALSO SHOW MID LEVEL
SHORTWAVE AND SURFACE FRONT MOVING ACROSS AREA. COMBINATION OF THE
LIFT FROM WAVE AND UPSLOPE BEHIND FRONT COULD PROVIDE SOME
PRECIPITATION ALONG WITH COOLER TEMPERATURES. GFS LOOKS MORE ROBUST
WITH STRENGTH OF TROUGH AND AMOUNT OF UPSLOPE THUS MORE
PRECIPITATION DEPICTED. WILL CONTINUE THE SLIGHT CHANCE OF SHOWERS
AND STORMS ALONG WITH COOLER CONDITIONS. ON THURSDAY...FLOW ALOFT
ACROSS PLAINS BECOMES SOUTHEAST WITH FLOW ALOFT REMAINING NORTHWEST.
STILL ENOUGH MOISTURE AND WEAK UPSLOPE FOR SOME CHANCE OF SHOWERS
AND/OR STORMS.
AVIATION...VFR CONDITIONS ARE EXPECTED AT DIA UNTIL ABOUT 09Z.
AFTER THAT...CEILINGS COULD GET DOWN TO 3000 FEET AGL. THE WINDS
ARE WILL LIKELY GO TO UPSLOPE (030 OR 040) AROUND 03Z THIS EVENING.
HYDROLOGY...RAINFALL AMOUNTS WILL BE BE LIGHT THE NEXT 24
HOURS...NOTHING OVER A QUARTER OF AN INCH EXPECTED.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM....D-L
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS DES MOINES IA
345 AM CDT FRI MAY 25 2012
.SHORT TERM.../TODAY/
MAIN CONCERN TODAY WILL BE PRECIP TRENDS. ACTIVE JET CONTINUES TO
ROUND PACIFIC NW UPPER LOW AND EXTENDS INTO THE NRN PLAINS. WATER
VAPOR IMAGERY SHOWS JET SEGMENT AND SUBTLE ENHANCEMENT OF UVM
EJECTING FROM UT INTO NE/KS...WHICH HAS AIDED WEAK SRN NE ELEVATED
CONVECTION. PRECIP ALSO NICELY REFLECTED IN RAP 305K ISENT SFC WITH
MOISTURE CONVERGENCE AND LOWER RH FOCUSED INTO THIS AREA. WEAK
KINEMATIC FORCING WILL PERSIST AND LIFT NWD WITH JET AND BUILDING
RIDGE LATER TODAY AND WILL ALSO DRAW INCREASED THERMODYNAMIC FORCING
NWD ON LEADING EDGE OF MUCAPE/ELEVATED INSTABILITY GRADIENT.
PHASING OF UVM AND ADEQUATE MOISTURE SEEMS WEAK THIS MORNING...SO
NOTHING MORE THAN SLIGHT POPS SW IN CASE SOMETHING DRIBBLES INTO
FORECAST AREA. HOWEVER FORCING MECHANISMS BECOME BETTER ORGANIZED
BY AFTERNOON WITH 00Z ECMWF/GFS BOTH SHOWING SHARPLY INCREASED
H85/H7 THETA-E ADVECTION INTO IA BY 00Z. THIS WILL LIKELY DEVELOP
ADDITIONAL SCATTERED SHOWERS/THUNDERSTORMS...WHICH IS ALSO DEPICTED
BY VARIOUS WRF SOLUTIONS.
08Z SURFACE ANALYSIS SHOWS RIDGE FROM NE INTO THE HEART OF IA WHICH
WILL KEEP MIXING REDUCED TODAY. MOS GUIDANCE SEEMS TO HAVE DECENT
HANDLE ON THIS WITH HIGHS IN THE 70S OR LOWER 80S.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
AS THE NEXT SHORTWAVE KICKS OUT OF THE WEST COAST TROUGH AND A
SOUTHERLY FLOW INCREASES OVER THE MIDWEST THE FRONT WHICH MOVED
THROUGH US YESTERDAY WILL LIFT NORTH OUT OF NORTHERN MISSOURI ACROSS
IOWA. 0-3KM SHEAR INCREASES THROUGH THE EVENING AS WELL AND LOOKING
AT SOUNDINGS THERE IS A 50-70KT JET OFF THE SURFACE AND IT IS
ACTUALLY TO A PRETTY GOOD DEPTH. STORMS THAT FIRE WILL EASILY HAVE
VERY ROBUST UPDRAFTS. EXPECTING MORE OF AN ELEVATED HAIL EVENT WITH
THE STORMS THIS EVENING AND LOCATION WILL DEPEND ON WHERE THE FRONT
WILL BE. CONVECTION MAY LINGER ACROSS CENTRAL IOWA INTO SATURDAY
MORNING THOUGH THAT FRONT WILL CONTINUE TO SHIFT EAST SO THE MAIN
AREA OF CONCERN FOR THUNDER WILL BE NORTHERN IOWA.
FOR THE REMAINDER OF SATURDAY AND SATURDAY NIGHT A STOUT CAP WILL BE
IN PLACE AND WE ARE LOOKING FOR LITTLE IN THE WAY OF CONVECTION IN
THE CWA...ASSUMING THE FRONT REMAINS IN SOUTHERN MN. SOUTHERLY
WINDS WILL BE ON THE INCREASE AGAIN ON SATURDAY POSSIBLY HAMPERED BY
CLOUD COVER AT LEAST INITIALLY. I DONT/ THINK WE WILL MIX AS GOOD
AS WE COULD.
FOR SUNDAY WE WILL SEE LESS CLOUD COVER AND A STRONGER SOUTH WIND
OVER THE AREA. I EXPECT THE CWA TO ONCE AGAIN BE CAPPED UNTIL A
COLD FRONT BEGINS TO PUSH INTO THE AREA LATE IN THE DAY AND
ESPECIALLY SUNDAY NIGHT. THERE WILL BE DEEP LAYER SHEAR WITH THIS
AND A STRONG JET AS A SHORT WAVE OVER THE PLAINS MOVES INTO WESTERN
IOWA. WE COULD SEE ALL MODES OF SEVERE WEATHER WITH THIS FRONT
THOUGH TIMING ISN/T THE BEST. DYNAMICALLY THOUGH I DONT THINK IT
WILL MATTER. WE WILL HAVE A LOT OF INSTABILITY WITH CAPES IN EXCESS
OF 1500 J/KG ADVECTING INTO THE AREA AND THE AFOREMENTIONED SHEAR.
SIMILAR TO THE OTHER NIGHT IT WILL LIKELY EVOLVE FROM SUPERCELLS
PRODUCING VERY LARGE HAIL AND SOME TORNADOES TO A LINEAR SYSTEM WITH
WIND DAMAGE PROBABLY OVER A FAIR PART OF THE CWA.
THE FRONT WILL HEAD EAST DURING THE DAY MONDAY ENDING THE THREAT FOR
STORMS BUT USHERING SOME PRETTY COOL AIR FOR EARLY NEXT WEEK.
BEYOND THAT THERE IS SUFFICIENT DISAGREEMENT ON A MID WEEK SHORTWAVE
THAT WILL BRING SHOWERS AND SOME THUNDER TO THE AREA BUT SHEAR IS
WEAK AND WE WILL BE MORE STABLE. KEPT THE POPS WE HAD GOING FOR
CONSISTENCY SAKE BUT TIMING AND LOCATION WILL NEED TO BE ADDRESSED
IN LATER FORECASTS.
&&
.AVIATION...25/06Z
VFR CONDITIONS FORECAST TO PREVAIL OVERNIGHT WITH SKC AND LIGHT AND
VARIABLE WINDS. MID LEVEL CIGS WILL INCREASE ON FRIDAY ALONG WITH
WINDS BECOMING EAST TO SOUTHEAST. POTENTIAL FOR A FEW SHOWERS AND
THUNDERSTORMS BY FRIDAY AFTERNOON AND EVENING. CIGS MAY DROP TO MVFR
BY THE EVENING IN A FEW LOCATIONS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...BSS
LONG TERM...FAB
AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
358 AM CDT FRI MAY 25 2012
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 341 AM CDT FRI MAY 25 2012
FOR THIS AFD UPDATE, NOT TOO MANY CHANGES WILL BE MADE. WE ALREADY
REMOVED THE CHANCE FOR THUNDERSTORMS THIS A.M., AS THE WARM FRONT
WAS WELL NORTH OF OUR AREA UP ALONG THE KANSAS/NEBRASKA BORDER.
SOME CAPE WAS STILL EVIDENT DOWN IN THE MEDICINE LODGE AREA, BUT
DO NOT SEE THE COLD FRONT SOUTH OF US MOVING NORTH TOO SOON. BY
THIS AFTERNOON, THE FRONT WILL GET PUSHED NORTH AS YET ANOTHER
WARM FRONT. THIS BOUNDARY MAY TRIGGER A FEW AFTERNOON SHOWERS AND
THUNDERSTORMS NORTH OF A SHALLOW WATER TO ASH VALLEY LINE, OR
NORTH A LINE FROM SCOTT COUNTY TO PAWNEE COUNTY. I PLACED 20 POPS
THERE AFTER 18Z. THE NAM MODEL WOULD HAVE THE PRECIP CHANCES A
TIER OF COUNTIES NORTHWARD, BUT THE HRRR MODEL IS SHOWING
CONVECTIVE INITIATION A LITTLE SOONER THAN THE NAM, AND ANOTHER
ROW OF COUNTIES SOUTHWARD. THIS SITUATION REMINDS ME OF YESTERDAY,
WHEN THE NAM PROVED TO BE MORE CORRECT (CONVECTION NORTH OF OUR
FORECAST AREA). SINCE 20 PERCENT POPS ARE CHEAP AND I DO NOT SEE
ANY REASON TO AT LEAST MENTION A SLIGHT CHANCE IN SCOTT, LANE,
NESS, RUSH AND PAWNEE, I PLANNED TO KEEP THE LOW POPS AS FAR SOUTH
AS A SCOTT TO PAWNEE COUNTY LINE. TEMPERATURES WILL RISE QUICKLY
DUE TO THE STRONG WARM AIR ADVECTION COMING NORTH FROM OKLAHOMA
BEHIND THE FRONT. DOWN NEAR THE OKLAHOMA BORDER, MAX T`S WILL
APPROACH THE CENTURY MARK. I DID NOTCH TEMPERATURES DOWN JUST A
DEGREE OR TWO, SINCE THE ADVANCEMENT NORTH OF THE WARM FRONT WILL
BE MAINLY DURING THE AFTERNOON HOURS. MAX T`S IN THE HAYS AND
WAKEENEY AREAS WILL TOP OUT IN THE UPPER 80S.
TONIGHT WILL SEE THE FRONT STRADDLING FROM NEAR SYRACUSE TO NESS
CITY AND THEN SOUTH INTO THE MEDICINE LODGE AREA. WITH THE STRONG
LOW LEVEL WARMING LEFT FROM THE DAY HEATING THE LOWER LEVELS WILL BE
PRIMED WITH INSTABILITY. THERE COULD BE A FEW STORMS NEAR AND NORTH
AND EAST OF THE FRONTAL BOUNDARY. HAD KEPT THE PREVIOUS SHIFT`S 20
POPS IN PLACE, AS THE UPPER SUPPORT MAY NOT BE SUFFICIENT FOR MANY
STORMS. WINDS TONIGHT WILL BE SOUTH AT 20 TO 25 MPH IN MOST
LOCATIONS HELPING TO ADVECT HIGHER DEW POINTS NORTH INTO SOUTHWEST
KANSAS. WINDS THEN WILL BECOME 10 TO 15 MPH AFTER MIDNIGHT, STILL
FROM THE SOUTH. MINIMUM TEMPERATURES TONIGHT SHOULD BE RELATIVELY
WARM, RANGING FROM THE LOWER 60S IN THE HAMILTON, STANTON, AND
MORTON COUNTY AREAS TO THE LOWER 70S IN THE PRATT, BARBER, AND
COMANCHE COUNTY AREAS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 354 AM CDT FRI MAY 25 2012
AN ACTIVE PERIOD IS UPON US FOR THE NEXT SEVERAL DAYS. THE
CONTINUING ISSUES OF WARM TEMPERATURES, WIND, CONVECTIVE CHANCES
REMAIN CHALLENGES FOR THE MEDIUM RANGE.
THE FIRST PROBLEM WILL BE WHERE AND WHEN ISOLATED THUNDERSTORMS MAY
OCCUR DURING THE DAY ON SATURDAY. THE OVERALL PATTERN IS ONE OF MID
LEVEL RIDGING WITH WESTERN AND CENTRAL KANSAS ON THE BACK SIDE OF THE
UPPER RIDGE. AT THIS TIME, THE MODELS THAT HAVE THE BEST AGREEMENT
APPEAR TO BE THE ECMWF AND THE NAM. THESE TEND TO PRODUCE
PRECIPITATION ALONG A DIFFUSE DRYLINE FEATURE, GENERALLY ALONG A
ROUGH HAYS TO MEADE LINE AND EASTWARD. MOST OF THIS CONVECTION WOULD
BE DISCREET WITH GOOD SEVERE HAIL POTENTIAL GIVEN THE INSTABILITY
POTENTIAL. THE GFS IS VERY DIFFERENT, HANGING THE DRYLINE/TROUGH
MUCH FARTHER WEST NEAR THE COLORADO LINE AND FOCUSING CONVECTION
LATE DAY OVER THE HIGHER TERRAIN.
SURFACE WINDS MAY ALSO BE A CHALLENGE TO FORECAST ON SATURDAY. THE
INTENSITY OF THE SURFACE LOW WILL BE A PRIMARY DETERMINANT OF THE
POTENTIAL. THE ECMWF INDICATES A 10 MB GRADIENT ACROSS THE AREA. THE
UPPER JETS DON`T REALLY APPEAR TO BE PHASED FOR THE GREATEST MIX
DOWN POTENTIAL THOUGH. THE GFSMOS IS SHOWING VERY STOUT 40-45 KNOT
SUSTAINED WIND SPEEDS, BUT MODELS ARE NOWHERE NEAR THIS SOLUTION AS
OF YET. A WINDY DAY WITH SUSTAINED WINDS IN EXCESS OF 30 MPH CAN BE
EXPECTED THOUGH WITH GOOD POTENTIAL FOR FREQUENT 40+ KT GUSTS.
WARM TEMPERATURES IN THE UPPER 90S ARE STILL ANTICIPATED GIVEN THE
WARM ADVECTION AND BOUNDARY LAYER AIRMASS - WITH A WEAK DOWNTREND IN
HIGHS THROUGH THE WEEKEND.
IN THE MEANTIME, AN IMPRESSIVE MID LEVEL TROUGH WITH EMBEDDED CLOSED
CIRCULATION WILL BE SWINGING THROUGH THE WESTERN STATES. A POTENT
JET STREAK IS MODELED TO MOVE THROUGH THE SOUTHERN ROCKIES AND
CENTRAL HIGH PLAINS REGIONS ON SUNDAY. THE TROUGH AND JET WILL ACT
TO INCREASE INSTABILITY, AS WELL AS LIFT THE DRYLINE/SURFACE
MOISTURE CONVERGENCE ZONE FARTHER NORTH AND EAST INTO THE AFTERNOON.
BETWEEN THE GFS/ECMWF AND THE NAM, THE AREAS OF BEST SEVERE WEATHER
THREAT APPEARS TO BE ACROSS NORTHWEST AND NORTH CENTRAL KANSAS. A
GOOD PORTION OF THE DODGE CITY FORECAST AREA SHOULD ALSO BE UNDER A
SUPERCELL HAIL, WIND AND TORNADO THREAT . THE SURFACE DRYLINE/WARM
SECTOR COULD EASILY BE ACTIVE ON THIS DAY. THE DEEP MEAN STORM
MOTIONS APPEAR STRONG AND PARALLEL TO THE DRYLINE WHICH COULD IMPLY
A FEW TORNADOES MIGHT BE MORE LIKELY.
WITH THE STRONG UPPER JET PRESENT, AND SOME RESIDUAL INSTABILITY
LIKELY STILL AROUND THE CENTRAL PLAINS, SHOWERS AND A FEW ROUNDS OF
THUNDERSTORMS MIGHT STILL OCCUR INTO SUNDAY NIGHT, WITH A DOWNTREND
INTO MONDAY MORNING. NORTHERLY SURFACE WINDS SHOULD BECOME DOMINANT
ON MONDAY WITH BREEZY TO WINDY CONDITIONS. BY TUESDAY, THE SURFACE
WINDS TURNS BACK AROUND INTO A WEAK UPSLOPE PATTERN AS ZONAL FLOW
ALOFT DEVELOPS AND STRONG HIGH PRESSURE BUILDS SOUTHWARD ACROSS THE
NORTHERN PLAINS. AT THAT POINT, THE MESOSCALE APPEARS TO ALLOW FOR
MOISTURE RETURN INTO THE CENTRAL PLAINS ALONG A MEAN BOUNDARY OVER
CENTRAL KANSAS AND OKLAHOMA. AS A RESULT THE ALLBLEND FORECAST
METHODOLOGY PRODUCES ABOUT 20 TO 40 PERCENT PRECIPITATION CHANCES;
INCREASING TUESDAY THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1215 AM CDT FRI MAY 25 2012
NORTHEAST WINDS SHOULD SHIFT SOUTHEAST TOWARDS SUNRISE AS AN AREA
OF LOW PRESSURE STRENGTHENS OVER NEW MEXICO TONIGHT. WIND SPEEDS WILL
INCREASE IN RESPONSE TO THE DEEPENING LOW PRESSURE. LOWER CLOUDS
ARE FORECAST TO INCREASE TONIGHT AOA040, BRINGING MVFR CONDITIONS
TO THE TAF SITES BEFORE SUNRISE. OTHERWISE VFR CONDITIONS WILL
PREVAIL AT ALL THREE TAF LOCATIONS BOTH PRIOR TO 09Z AND AFTER
13Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 96 68 98 68 / 10 10 30 30
GCK 94 65 97 67 / 10 10 20 20
EHA 97 63 96 65 / 0 10 20 20
LBL 99 66 97 67 / 10 10 30 30
HYS 88 66 98 70 / 20 20 30 30
P28 94 71 97 70 / 20 20 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURKE
LONG TERM...RUSSELL
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
343 AM CDT FRI MAY 25 2012
...UPDATED FOR THE SHORT TERM DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 341 AM CDT FRI MAY 25 2012
FOR THIS AFD UPDATE, NOT TOO MANY CHANGES WILL BE MADE. WE ALREADY
REMOVED THE CHANCE FOR THUNDERSTORMS THIS A.M., AS THE WARM FRONT
WAS WELL NORTH OF OUR AREA UP ALONG THE KAUNAS/NEBRASKA BORDER.
SOME CAPE WAS STILL EVIDENT DOWN IN THE MEDICINE LODGE AREA, BUT DO
NOT SEE THE COLD FRONT SOUTH OF US MOVING NORTH TOO SOON. BY THIS
AFTERNOON, THE FRONT WILL GET PUSHED NORTH AS YET ANOTHER WARM
FRONT. THIS BOUNDARY MAY TRIGGER A FEW AFTERNOON SHOWERS AND
THUNDERSTORMS NORTH OF A SHALLOW WATER TO ASH VALLEY LINE, OR NORTH
A LINE FROM SCOTT COUNTY TO PAWNEE COUNTY. I PLACED 20 POPS THERE
AFTER 18Z. THE NAM MODEL WOULD HAVE THE PRECIP CHANCES A TIER OF
COUNTIES NORTHWARD, BUT THE HRRR MODEL IS SHOWING CONVECTIVE
INITIATION A LITTLE SOONER THAN THE NAM, AND ANOTHER ROW OF COUNTIES
SOUTHWARD. THIS SITUATION REMINDS ME OF YESTERDAY, WHEN THE NAM
PROVED TO BE MORE CORRECT (CONVECTION NORTH OF OUR FORECAST AREA).
SINCE 20 PERCENT POPS ARE CHEAP AND I DO NOT SEE ANY REASON TO AT
LEAST MENTION A SLIGHT CHANCE IN SCOTT, LANE, NESS, RUSH AND PAWNEE,
I PLANNED TO KEEP THE LOW POPS AS FAR SOUTH AS A SCOTT TO PAWNEE
COUNTY LINE. TEMPERATURES WILL RISE QUICKLY DUE TO THE STRONG WARM
AIR ADVECTION COMING NORTH FROM OKLAHOMA BEHIND THE FRONT. DOWN
NEAR THE OKLAHOMA BORDER, MAX T`S WILL APPROACH THE CENTURY MARK. I
DID NOTCH TEMPERATURES DOWN JUST A DEGREE OR TWO, SINCE THE
ADVANCEMENT NORTH OF THE WARM FRONT WILL BE MAINLY DURING THE
AFTERNOON HOURS. MAX T`S IN THE HAYS AND WAKEENEY AREAS WILL TOP
OUT IN THE UPPER 80S.
TONIGHT WILL SEE THE FRONT STRADDLING FROM NEAR SYRACUSE TO NESS
CITY AND THEN SOUTH INTO THE MEDICINE LODGE AREA. WITH THE STRONG
LOW LEVEL WARMING LEFT FROM THE DAY HEATING THE LOWER LEVELS WILL BE
PRIMED WITH INSTABILITY. THERE COULD BE A FEW STORMS NEAR AND NORTH
AND EAST OF THE FRONTAL BOUNDARY. HAD KEPT THE PREVIOUS SHIFT`S 20
POPS IN PLACE, AS THE UPPER SUPPORT MAY NOT BE SUFFICIENT FOR MANY
STORMS. WINDS TONIGHT WILL BE SOUTH AT 20 TO 25 MPH IN MOST
LOCATIONS HELPING TO ADVECT HIGHER DEW POINTS NORTH INTO SOUTHWEST
KANSAS. WINDS THEN WILL BECOME 10 TO 15 MPH AFTER MIDNIGHT, STILL
FROM THE SOUTH. MINIMUM TEMPERATURES TONIGHT SHOULD BE RELATIVELY
WARM, RANGING FROM THE LOWER 60S IN THE HAMILTON, STANTON, AND
MORTON COUNTY AREAS TO THE LOWER 70S IN THE PRATT, BARBER, AND
COMANCHE COUNTY AREAS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 255 PM CDT THU MAY 24 2012
FRIDAY NIGHT:
I HAVE SLIGHT CHANCE POPS ROUGHLY FROM HAYS TO MEDICINE LODGE FRIDAY
EVENING IN ASSOCIATION WITH POSSIBLE CONVECTION ALONG THE DRYLINE DURING
THE EVENING. 700 HPA TEMPERATURES ARE FORECAST TO BE QUITE WARM @ 14
DEG C, HOWEVER, SURFACE TEMPERATURES ARE HOT (UPPER 90S TO AROUND 100
DEG F) SO THE CAP MIGHT BE BREAKABLE. NAM SHOWS ABOUT 2000 J/KG OF SBCAPE
AND 0 TO 6 KM BULK SHEAR OF AROUND 30 TO 40 KT. SO IF CONVECTION DOES
FORM, THEN A LOW END SEVERE EVENT IS POSSIBLE. THE ATMOSPHERE IS WELL
MIXED TO ABOUT 550 HPA WITH FORECAST SOUNDINGS DISPLAYING AN INVERTED
V THERMODYNAMIC PROFILE SO SEVERE WIND GUSTS AROUND 50 TO 60 MPH WOULD
BE THE MAIN CONCERN. OVERNIGHT LOWS WILL BE ON THE MILD SIDE... 60S
DEG F WEST AND AROUND 70 DEG F SOUTHEAST.
SATURDAY:
THE WARM SECTOR SPREADS NORTHWARD SATURDAY WITH LOW LEVEL THETA-E AIR
INCREASING OVER THE REGION...ERGO, A MORE CONVECTIVELY UNSTABLE ATMOSPHERE
IS EXPECTED THROUGH THE AFTERNOON AND EARLY EVENING. FOLLOWED THE ECMWF
FOR GUIDANCE AND HAVE MAX TEMPERATURES IN THE UPPER 90S DEG F ACROSS
SW KANSAS. WOULD NOT BE SURPRISED IF A FEW LOCATIONS REACHED 100 DEG
F. BROAD BRUSHED THE CENTRAL AND WESTERN ZONES WITH SLIGHT POPS DUE
TO CONVECTIVE TEMPERATURES BEING REACHED WITH ISOLATED THUNDERSTORMS
POSSIBLE. KINEMATIC PROFILES FROM THE ECMWF/GFS ARE FAIRLY UNIDIRECTIONAL
AND DISPLAYING AN INVERTED V PROFILE AGAIN SO ISOLATED SEVERE WIND GUSTS
REPORTS ARE POSSIBLE.
SUNDAY:
SUNDAY IS THE MOST INTERESTING DAY IN TERMS OF SEVERE WEATHER PROSPECTS.
A 250 HPA JET STREAK WILL MOVE ACROSS NEBRASKA WHICH WILL PUT WESTERN
KANSAS IN THE RIGHT ENTRANCE REGION OF SAID JET STREAK. HAVE THE HIGHEST
POPS NEAR HAYS CLOSER TO THE EXPECTED TRIPLE POINT OF THE SURFACE LOW
PRESSURE CENTER, WARM FRONT AND DRYLINE. TORNADO POTENTIAL MIGHT BE
LOWER IF LCL`S REMAIN HIGH, WHICH IS FORECAST BY THE ECMWF AND LESS
THE GFS. THERE IS ENOUGH DIRECTIONAL AND SPEED SHEAR THAT ROTATING SUPERCELLS
WILL BE LIKELY. RIGHT NOW, IF ONE WERE TO BELIEVE THE MESOSCALE NAM
MODEL (ALTHOUGH NOT PREFERRED THIS FAR OUT) THAN SIGNIFICANT HAIL IS
MORE OF A CONCERN. 700-500 HPA LAPSE RATES ARE STEEP AROUND 8.2 DEG
C/KM WITH A FAVORABLE AND MORE SHALLOW 500-300 HPA LAPSE RATES AROUND
7.2 DEG C/KM. IN ADDITION, 3 TO 6 KM SR FLOW IS FAIRLY WEAK AT 18 KT
WHICH MIGHT HELP THE HYDROMETEORS IN BECOMING REINGESTED INTO THE
UPDRAFT. LASTLY, ANVIL LEVEL SR WINDS ARE STRONGER THAN 25 KT WHICH
IS FAVORABLE FOR SIGNIFICANT HAIL (THINKING UP TO TENNIS BALL SIZE)
VIA MORE CLASSIC STORM MODE THAN HP.
MONDAY AND BEYOND:
EXPECTING A DRY FORECAST MONDAY AS THE UPPER LEVEL FLOW BECOMES FLAT
IN THE WAKE OF THE DEPARTING SYNOPTIC WAVE. FOLLOWED THE WARMER ECMWF
THAN COMPARED TO THE ALLBLEND AS THE ALLBLEND LOOKS A LITTLE TOO COOL
GIVEN LOW LEVEL THICKNESS PROGS. WILL KEEP POPS FROM THE ALLBLEND SOLUTION
TUESDAY THROUGH WEDNESDAY DUE TO THE POTENTIAL FOR A FEW THUNDERSTORM
COMPLEXES ASSOCIATED WITH SHORTWAVE TROUGHS EMBEDDED IN THE W TO EVENTUALLY
NW FLOW ALOFT. IT SHOULD BE NOTED THAT CONFIDENCE IS LOW DURING THIS
PERIOD REGARDING THESE POPS. AS USUAL, THE GFS IS WETTER THAN THE ECMWF.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1215 AM CDT FRI MAY 25 2012
NORTHEAST WINDS SHOULD SHIFT SOUTHEAST TOWARDS SUNRISE AS AN AREA
OF LOW PRESSURE STRENGTHENS OVER NEW MEXICO TONIGHT. WIND SPEEDS WILL
INCREASE IN REPONSE TO THE DEEPENING LOW PRESSURE. LOWER CLOUDS
ARE FORECAST TO INCREASE TONIGHT AOA040, BRINGING MVFR CONDITIONS
TO THE TAF SITES BEFORE SUNRISE. OTHERWISE VFR CONDITIONS WILL
PREVAIL AT ALL THREE TAF LOCATIONS BOTH PRIOR TO 09Z AND AFTER
13Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 96 68 98 68 / 10 10 30 30
GCK 94 65 97 67 / 10 10 20 20
EHA 97 63 96 65 / 0 10 20 20
LBL 99 66 97 67 / 10 10 30 30
HYS 88 66 98 70 / 20 20 30 30
P28 94 71 97 70 / 20 20 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURKE
LONG TERM...SUGDEN
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1130 PM MDT THU MAY 24 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 256 PM MDT THU MAY 24 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH
EXTENDING FROM THE PACIFIC NORTHWEST ACROSS T HE NORTHERN
PLAINS...WITH WEST/SOUTHWEST FLOW OVER THE CENTRAL ROCKIES AND
CENTRAL HIGH PLAINS. A SERIES OF SHORTWAVE TROUGHS ARE CURRENTLY
TRACKING WITHIN THE MEAN FLOW WITH SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THESE FEATURES OVER NORTHERN COLORADO AND NORTH
CENTRAL NEBRASKA. A STATIONARY FRONT EXTENDS FROM EASTERN KANSAS
SOUTH INTO NORTHCENTRAL TEXAS...AND THEN NORTH INTO SOUTH-CENTRAL
COLORADO.
TONIGHT...A CLOSED LOW CENTER WITHING THE LARGE SCALE TROUGH WILL
MOVE EAST/NORTHEAST INTO THE NORTHERN PLAINS WITH LARGE SCALE
ASCENT SPREADING SOUTH AND EAST TOWARDS SOUTHWEST NEBRASKA. THE
STATIONARY FRONT TO THE SOUTH WILL BEGIN TO MOVE NORTH IN RESPONSE
TO STRENGTHENING LEE TROUGH OVER EASTERN COLORADO. A STRONG LLJ IS
ADVERTISED TO DEVELOP BY 06Z TONIGHT WHICH COULD ALSO ACT AS A
FOCUS FOR SHOWER THUNDERSTORM DEVELOPMENT OVER OUR CWA. VERY
STRONG SHEAR WILL DEVELOP OVERNIGHT ALONG WITH ELEVATED
INSTABILITY NEAR THE NOSE OF THE LLJ. BEST FORCING LOOKS TO BE
EITHER NORTH OR SOUTH OF THE CWA. IM ALSO NOT SURE ABOUT HOW MUCH
TD WILL RECOVER NORTH OF THE FRONT. I KEPT POPS IN THE SLIGHT
CHANCE/CHANCE CATEGORY...WITH BEST COVERAGE LATE TONIGHT WHEN LLJ
IS EXPECTED TO DEVELOP. THERE CONTINUES TO BE INDICATION OF FOG
DEVELOPMENT WITH EASTERLY FLOW AROUND SUNRISE TOMORROW...SO I KEPT
PATCHY FOG MENTION.
FRIDAY..SHOWER/THUNDERSTOM ACTIVITY SHOULD COME TO AN END FROM
THE SOUTHWEST TO THE NORTHEAST THROUGH THE DAY...WITH ACTIVITY
POSSIBLY LINGERING OVER NORTHERN PARTS OF THE FORECAST AREA INTO
FRIDAY EVENING. THERE IS A LARGE SPREAD IN GUIDANCE ON TIMING OF
WARM FRONT FRIDAY WITH NAM THE SLOW OUTLIER. NAM SOLUTION WOULD
KEEP STRATUS/FOG IN PLACE ALONG WITH MUCH COOLER AIRMASS.
GFS/ECMWF FAVOR THE CLEARING SOLUTION ALONG WITH MUCH WARMER
TEMPERATURES ACROSS THE SOUTHWEST..WHICH IS WHERE I LEANED THIS
FORECAST CYCLE.
FRIDAY NIGHT...PRIMARY ADJUSTMENT TO THIS PERIOD WAS TO BUMP
OVERNIGHT LOWS UP A NOTCH OR TWO WITH SOUTHERLY/SOUTHEASTERLY FLOW
IN PLACE ACROSS THE FORECAST AREA. WILL SEE SLIGHT CHANCE/CHANCE
POPS OVER THE FAR NORTHEAST PORTION OF THE FORECAST AREAS DURING
THE OVERNIGHT HOURS BEFORE SHIFTING OUT OF THE AREA BY AROUND
SUNRISE ON SATURDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 256 PM MDT THU MAY 24 2012
ACTIVE WEATHER PATTERN SETTING UP FOR THE EXTENDED WITH A FEW
PERIODS OF STRONG TO SEVERE CONVECTION APPEARING POSSIBLE.
SATURDAY AND SATURDAY NIGHT...WARM FRONT LIFTS NORTH INTO NEBRASKA
DURING THE DAY WITH A DRYLINE SETTING UP. H85 TEMPS WARM TO AROUND
30C OVER EASTERN COLORADO WITH MID TO UPPER 20S C ELSEWHERE.
RESULT WILL BE AFTERNOON TEMPS APPROACHING THE CENTURY MARK IN A
FEW LOCATIONS. EVERYONE SHOULD SEE AT LEAST THE LOW/MID 90S.
SATURDAY LOOKS TO BE A VERY WINDY DAY ACROSS AT LEAST THE WESTERN
TWO-THIRDS OF THE FORECAST AREA WITH LATEST GUIDANCE HINTING AT
THE POTENTIAL FOR BORDERLINE HIGH WIND WARNING GUSTS. CONSIDERED
HOISTING A HIGH WIND WATCH FOR WESTERN HALF BUT OPTED TO HOLD OFF
AND ALLOW OVERNIGHT SHIFT TO HAVE ANOTHER RUN OF NWP GUIDANCE. AT
THE LEAST...APPEARS AS THOUGH A WIND ADVISORY WILL BE NEEDED FOR
MUCH OF THE AREA. DEW POINTS WILL TANK ACROSS THE WEST WHICH WILL
RESULT IN RH VALUES FALLING TO AROUND 10 PERCENT. FUELS PAGE
INDICATES SUFFICIENT GREEN-UP IS ONGOING WHICH MAY LIMIT FIRE
WEATHER POTENTIAL BUT THIS IS ALSO SOMETHING THAT WILL NEED TO
BE MONITORED OVER THE NEXT FEW FORECAST SHIFTS. DISCREPANCIES DO
EXIST IN THE PLACEMENT OF THE DRYLINE BUT A SLIGHT CHANCE FOR
CONVECTION OVER THE EASTERN HALF OF THE FORECAST AREA APPEARS
JUSTIFIED. GIVEN INVERTED-V NATURE OF VERTICAL SOUNDING
PROFILES...ANY STORM WHICH DEVELOPS WILL HAVE THE POTENTIAL TO
PRODUCE STRONG WIND GUSTS. LARGE HAIL WILL ALSO BE POSSIBLE THOUGH
SHEAR PROFILES DON`T BECOME STRONGLY FAVORABLE UNTIL AFTER 00Z.
SUNDAY AND SUNDAY NIGHT...POTENT MID/UPPER TROUGH WILL BEGIN TO
TRANSLATE ACROSS THE GREAT BASIN/ROCKIES ON SUNDAY WITH INCREASING
FORCING FOR ASCENT AS THE DAY PROGRESSES. PRIMARY QUESTION WILL BE
THE ULTIMATE LOCATION OF THE DRYLINE. EAST OF THE DRYLINE...DEW
POINT WILL SURGE INTO THE UPPER 50S AND PERHAPS EVEN THE LOWER
60S. DEEP LAYER SHEAR OF 40 TO 50 KTS WILL AID IN UPDRAFT
ORGANIZATION WHILE STRONG LOW LEVEL PARAMETERS WOULD ALSO SUPPORT
A TORNADO THREAT. GREATEST THREAT IS CURRENTLY INDICATED TO BE
GENERALLY ALONG AND EAST OF THE HIGHWAY 83 CORRIDOR. INTERESTED
PARTIES WILL WANT TO CLOSELY MONITOR THE LATEST FORECAST
INFORMATION.
MONDAY THROUGH TUESDAY...PRIMARY MID/UPPER LOW SHIFTS EASTWARD
ACROSS THE SOUTHERN PRAIRIE PROVINCES OF CANADA MONDAY INTO
TUESDAY MORNING WITH WEAK RIDGING/QUASI-ZONAL FLOW ACROSS THE
CENTRAL HIGH PLAINS. RESULT SHOULD BE SEASONABLE TEMPS WITH DRY
CONDITIONS EXPECTED UNTIL AT LEAST TUESDAY AFTERNOON WHEN A
SHORTWAVE TROUGH MOVES ACROSS THE AREA.
WEDNESDAY THROUGH THURSDAY...MID/UPPER RIDGING BUILDS ACROSS THE WESTERN
CONUS WITH A NEGATIVELY TILTED SHORTWAVE TROUGH AND AN ASSOCIATED
SURFACE COLD FRONT DROPPING SOUTHEAST ACROSS THE DAKOTA AND
NEBRASKA. BROAD SCALE FORCING FOR ASCENT INCREASES BY WEDNESDAY
AFTERNOON WHICH WILL AID IN THE DEVELOPMENT OF CONVECTION OVER
PRIMARILY SOUTHWEST NEBRASKA AND NORTHWEST KANSAS. WILL CARRY
PRIMARILY CHANCE POPS DURING THIS TIME PERIOD WITH MUCH COOLER AIR
FILTERING INTO THE REGION BEHIND THE FRONT ON THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1125 PM MDT THU MAY 24 2012
LINE OF SHOWERS AND ISOLATED THUNDERSTORMS WILL MOVE THROUGH THE
KMCK AREA OVERNIGHT THEN CONTINUE TO MOVE NORTH. VFR EXPECTED TO
PREVAIL ALTHOUGH MAY VERY BRIEFLY GET INTO MVFR ON THE CEILINGS IF
A THUNDERSTORM WERE TO MOVE DIRECTLY OVER THE TERMINAL.
OTHERWISE...MAIN CONCERN WILL BE THE POSSIBILITY OF LOWER CEILINGS
IN THE LATE MORNING TO EARLY AFTERNOON HOURS WITH PERSISTENT AREA
OF SHOWERS. SOUTHERLY WINDS WILL INCREASE IN THE AFTERNOON...PARTICULARLY
AT KGLD WHERE THEY COULD GUST TO NEAR 30KTS.
&&
.CLIMATE...
ISSUED AT 245 AM MDT THU MAY 24 2012
RECORD AND NEAR RECORD HIGH TEMPERATURES EXPECTED SATURDAY.
GOODLAND.....97 IN 2006
HILL CITY....99 IN 1912
MCCOOK.......98 IN 1967
BURLINGTON...95 IN 1942
YUMA.........96
TRIBUNE......101
COLBY........98
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR/FOLTZ
LONG TERM...FOLTZ
AVIATION...024
CLIMATE...007
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
317 AM CDT FRI MAY 25 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
317 AM CDT FRI MAY 25 2012
MAIN FORECAST CONCERNS ARE ON CONVECTIVE POTENTIAL THROUGHOUT...
ALONG WITH ANY SEVERE WEATHER CONCERNS.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED DEEP TROUGHING OVER NORTHERN CALIFORNIA (2-2.5 STANDARD
DEVIATIONS BELOW NORMAL)...RIDGING BUILDING UP OVER THE CENTRAL
PLAINS...AND A POTENT SHORTWAVE TROUGH MOVING THROUGH UPPER
MICHIGAN. THE FORECAST AREA LIES IN SUBSIDENCE IN THE WAKE OF THE
SHORTWAVE TROUGH...WHICH HAS RESULTED IN DRYING AND CLEARING SKIES.
00Z MPX SOUNDING SHOWED SOME OF THE DRYING COMING IN ABOVE 700MB.
SURFACE COLD FRONT ASSOCIATED WITH THE POTENT SHORTWAVE EXTENDS FROM
LAKE MICHIGAN...SOUTHWEST TO SPRINGFIELD MO...THEN TURNS INTO A WARM
FRONT CONNECTING TO A LOW IN NORTHEAST NEW MEXICO. SOUTH OF THAT
WARM FRONT...DEWPOINTS ARE NEAR 70. COMPARE THESE TO THE AROUND 50
DEWPOINTS THAT HAVE ADVECTED IN BEHIND THE FRONT OVER THE FORECAST
AREA.
TODAY AND TONIGHT...UPPER TROUGHING OVER NORTHERN CALIFORNIA IS
FORECAST TO DIG SOUTHWARD THROUGH THE STATE...CAUSING SIGNIFICANT
HEIGHT RISES AT 500MB UP AND DOWN THE MISSISSIPPI RIVER VALLEY.
BETWEEN 12Z TODAY AND 12Z SATURDAY...500MB HEIGHTS RISE 180 METERS
AT LA CROSSE. ACCOMPANYING THESE SIGNIFICANT HEIGHT RISES WILL BE AN
INTENSIFYING LOW LEVEL JET OVER THE PLAINS...PROPELLING THE WARM
FRONT IN OKLAHOMA NORTHWARD AT A RAPID CLIP. BY 12Z SATURDAY...VERY
GOOD AGREEMENT EXISTS THAT THE WARM FRONT SHOULD BE APPROACHING I-80
IN IOWA. THE MAIN CONCERN IS PRECIPITATION CHANCES GIVEN SUCH RAPID
CHANGES GOING ON. EXPECT THE MORNING TO REMAIN DRY WITH THE FORECAST
AREA STILL FEELING SUBSIDENCE IN THE WAKE OF LAST NIGHTS SHORTWAVE
TROUGH. DURING THE AFTERNOON...INCREASING 800MB TO 700MB MOISTURE
TRANSPORTED IS NOTED...WHICH WILL AT A MINIMUM CAUSE AN INCREASE IN
ALTOSTRATUS. SOME MODELS HAVE SUGGESTED SOME LIGHT SHOWERS
DEVELOPING OUT OF THESE CLOUDS...MOSTLY WEST OF THE MISSISSIPPI
RIVER AND EVEN THAT MOSTLY WEST OF THE FORECAST AREA. FORECAST
SOUNDINGS DO DEPICT QUITE A BIT OF DRY AIR BELOW THE ALTOSTRATUS...
WHICH MAY ABSORB SOME OF THE RAIN. THEREFORE...HAVE KEPT ANY PRECIP
TO SPRINKLES THIS AFTERNOON...AND ONLY WEST OF THE MISSISSIPPI
RIVER. THINGS GET A BIT TRICKY TONIGHT. AS THE LOW LEVEL JET AND
MOISTURE TRANSPORT INCREASES...NUMEROUS CONVECTION IS LIKELY TO
DEVELOP OVER IOWA NORTH OF THE WARM FRONT. THE QUESTION IS WILL IT
TURN INTO AN MCS OR NOT...SINCE THAT WOULD LIKELY SLOW THE WARM
FRONTS NORTHWARD PROGRESS FOR LATER IN THE FORECAST...AND IMPACT
HOW MUCH PRECIPITATION IMPACTS THE AREA GIVEN NORTHWEST TO SOUTHEAST
ORIENTED CORFIDI VECTORS. MAIN UPPER JET IS WELL TO THE NORTH OVER
NORTHERN MINNESOTA...SO NO UPPER DIVERGENCE HELP. 500MB HEIGHTS ARE
RISING WITH NO SHORTWAVE EVIDENT...SO NO SUPPORT THERE. IT SEEMS THE
ONLY THING GOING FOR AN MCS IS THE MOISTURE TRANSPORT...WHICH IS
BROAD. THEREFORE...THINK WHAT MOST OF THE MODELS DEPICT WITH QPF...
I.E SHOWERS AND THUNDERSTORMS...GRADUALLY LIFTING NORTH WITH THE
FRONT SEEMS REASONABLE. WITH WARM CLOUD DEPTHS APPROACH 3.5-4
KM...ANY SHOWERS LIKELY TO PRODUCE HEAVY RAIN...THOUGH LACK OF AN
MCS OR STATIONARY BOUNDARY PREVENTS ANY FLOOD CONCERN AT THIS TIME.
ALTHOUGH 1-6 KM SHEAR IS 40 OR MORE KNOTS...SKINNY CAPE AND HIGH
FREEZING LEVELS MAY KEEP THE MAIN THREAT BESIDES RAIN TO GUSTY WINDS
FROM THE STORMS. COOLER DAY ON TAP TODAY WITH 850MB TEMPS OF 8-10C
AND INCREASING AFTERNOON CLOUDS. HIGHS IN THE 70S SEEM REASONABLE.
WENT WITH A BLEND OF GUIDANCE FOR LOWS TONIGHT.
SATURDAY THROUGH SUNDAY...WARM FRONT LOOKS TO CONTINUE ITS NORTHWARD
PROGRESS AS THE TROUGHING IN CALIFORNIA LIFTS INTO THE HIGH PLAINS
LATE SUNDAY. WARM FRONT SHOULD APPROACH I-90 BY 00Z SUNDAY. SOUTH OF
THIS FRONT...A PLUME OF HOT AND HUMID AIR REFLECTED BY 850MB TEMPS
OF 20C PLUS...AS WELL AS THOSE DEWPOINTS SEEN IN OKLAHOMA...WILL
ADVECT IN. THEREFORE...PLENTIFUL CAPE IS LIKELY ON AND ADVECTING
NORTH WITH THE FRONT. PROBLEM WE MAY HAVE CONTEND WITH FOR
SATURDAY...AFTER ANY MORNING CONVECTION RELATED TO TONIGHT...IS
CAPPING ADVECTING NORTH OF THE FRONT AT 750MB. MLCIN VALUES ARE
SUBSTANTIAL...UPWARDS OF 200 J/KG OR SO FOR THE AFTERNOON. MUCH OF
THE MODEL QPF ON SATURDAY...PARTICULARLY AFTERNOON...SEEMS TO BE
RELATED TO BELOW THE CAP. THEREFORE...NOT SURE HOW MUCH OF IT IS
REAL. HAVE LOWERED PRECIPITATION CHANCES IN THE AFTERNOON SOUTH OF
I-94 AS A RESULT. THIS MATCHES TOO WITH THE 25.00Z REGIONAL
CANADIAN...LOCAL WRF-ARW RUN AND HIRES WRF-ARW RUN FROM NCEP. BEST
CHANCES FOR PRECIP IN THE AFTERNOON IS NORTH OF I-94 WHERE LESS CAP
EXISTS. CAP...WARM AIR AND FRONT SHOULD CONTINUE TO LIFT NORTH
ACROSS THE AREA SATURDAY NIGHT...THOUGH DID KEEP SOME CHANCES NORTH
OF I-94 WHERE RE-INVIGORATED MOISTURE TRANSPORT MAY ALLOW CONVECTION
TO GO. VERY WARM NIGHT ANTICIPATED SOUTH OF THE FRONT. SUNDAY SHOULD
BE MOSTLY DRY WITH THE HOTTEST DAY OF THE YEAR THUS FAR. 850MB TEMPS
OF 22C AT 18Z PLUS PLENTY OF SUN AND A BREEZY SOUTHWEST WIND
EXPECTED TO SUPPORT HIGHS MOSTLY IN THE 90S. STAYED AT THE HIGH END
OF GUIDANCE FOR HIGHS GIVEN THE SETUP. IF TEMPERATURES LOOK WARMER
IN LATER FORECASTS...MAY NEED TO CONSIDER A HEAT ADVISORY.
SUNDAY NIGHT...TROUGH OVER THE HIGH PLAINS IS PROGGED TO START
MOVING EAST...DRIVING A COLD FRONT TO NEAR I-35 BY 12Z MONDAY. DPVA
AHEAD OF THIS TROUGH...ALONG WITH SOME RIGHT ENTRANCE REGION
SUPPORT...LOW TO MID-LEVEL FRONTOGENESIS ALONG THE FRONT AND
INSTABILITY WILL ALL COME TOGETHER TO PRODUCE A NORTHEAST TO
SOUTHWEST ORIENTED BAND OF CONVECTION. MUCH OF THIS CONVECTION
SHOULD STAY WEST OF THE AREA IN THE EVENING...THEN MOVE INTO
SOUTHEAST MINNESOTA...NORTHEAST IOWA AND POSSIBLY NORTH CENTRAL
WISCONSIN AFTER MIDNIGHT. STORMS ARE LIKELY TO BE SEVERE WHEN THEY
INITIALLY FORM IN THE EVENING WEST OF THE AREA...AS INDICATED TOO BY
THE SPC DAY 3 OUTLOOK SEVERE PROBABILITIES. NOT SURE IF THEY WILL BE
SEVERE BY THE TIME THEY REACH THE FORECAST AREA...THOUGH...AS THE
MLCAPE REALLY TAILS OFF THROUGH THE NIGHT. THE SHEAR IS THERE...
THOUGH...ENOUGH PROBABLY TO WARRANT THE GENERAL SLIGHT RISK. WITH A
BREEZY NIGHT AND COLD FRONT/PRECIPITATION NOT COMING UNTIL
LATE...ANTICIPATING ANOTHER WARM NIGHT. LOWS MAY NEED TO BE RAISED
MORE THAN CURRENTLY FORECAST.
.LONG TERM...MONDAY THROUGH THURSDAY NIGHT
317 AM CDT FRI MAY 25 2012
AFTER A HOT SUNDAY...THE LONG TERM PERIOD FEATURES A PATTERN SHIFT
TO ONE COOLER THAN NORMAL. THIS IS IN RESPONSE TO THE TROUGHING OVER
THE NORTHERN PLAINS SUNDAY NIGHT EVENTUALLY BECOMING STUCK OVER
ONTARIO AND THE GREAT LAKES REGION. IN FACT...COME THURSDAY...THERE
IS A RE-ENFORCING POTENT SHORTWAVE DROPPING SOUTH THROUGH THE
PLAINS.
MAIN FOCUS ON THE LONG TERM PERIOD IS MONDAY...IN PARTICULAR THE
COLD FRONT COMING ACROSS THE FORECAST AREA WITH THE UPPER TROUGH.
MODELS ARE IN GOOD AGREEMENT NOW WITH THE FRONT CROSSING THE AREA
MID-DAY. HOW MUCH CONVECTION WILL BE ON THIS FRONT IS A QUESTION.
THE CONVECTION FROM SUNDAY NIGHT MAY END UP FALLING APART DUE TO
LOSS OF INSTABILITY. THEN DURING THE AFTERNOON...DEPENDING
SPECIFICALLY ON TIMING...AFTER DAYTIME INSTABILITY BUILDS THE
CONVECTION COULD FIRE ON THE FRONT AFTER IT HAS PASSED THROUGH THE
AREA. THEREFORE...PRECIPITATION CHANCES ARE ONLY 30-50 AT THIS TIME.
A FEW MODELS...THE 25.00Z ECMWF AND OUR LOCAL WRF RUN...SUGGEST THE
POTENTIAL FOR A NEARLY DRY FRONTAL PASSAGE. IF THERE IS ANY
POTENTIAL FOR SEVERE...SEEMS LIKE THAT WOULD OCCUR IN OUR FAR
EASTERN AREAS.
MAINLY DRY AND COOLER WEATHER LOOKS TO PREVAIL FOR MONDAY NIGHT
THROUGH TUESDAY NIGHT THANKS TO SUBSIDENCE ON THE BACK SIDE OF THE
UPPER TROUGH. 20-40 PERCENT CHANCES OF SHOWERS ENTER THE FORECAST
FOR WEDNESDAY THROUGH THURSDAY...ASSOCIATED WITH THAT POTENT
SHORTWAVE DROPPING DOWN THROUGH THE PLAINS. NOTE...THOUGH...THAT IT
IS ENTIRELY POSSIBLE THIS SHORTWAVE AND ITS ASSOCIATED PRECIPITATION
STAYS AWAY FROM THE AREA ...THUS ONLY THE 20-40 PERCENT VALUES.
ONE THING WE NEED TO WATCH OUT FOR TOO MAY BE FROST LATER OUT. THE
25.00Z ECMWF SHOWS 850MB TEMPS OVER TAYLOR COUNTY DROPPING TO AROUND
0C AT 12Z WEDNESDAY WITH HIGH PRESSURE BUILDING IN. RIGHT NOW NO
FROST OR EVEN TEMPERATURES CLOSE TO FROST IS IN THE FORECAST...BUT
SOMETHING AGAIN TO WATCH.
&&
.AVIATION...
1110 PM CDT THU MAY 24 2012
CONCERN FOR FOG AT KLSE EARLY FRI MORNING AS SKIES SHOULD CLEAR AND
WINDS LOOK LIGHTER THAN ORIGINALLY FORECAST. WITH RAIN SATURATING
THE BOUNDARY LAYER...A GOOD SETUP FOR FOG. SEE SOME POTENTIAL FOR
SUB 1SM BR IF EVERYTHING COMES TOGETHER JUST RIGHT...BUT CONFIDENCE
ISN/T THERE AT THIS TIME. WILL LEAVE AT 2SM BR...BUT OBS AND TRENDS
WILL HAVE TO BE MONITORED CLOSELY.
LOW LEVEL WARM AIR ADVECTION WILL PUSH NORTHWARD INTO THE REGION ON
FRIDAY...AND EXPECT INCREASING CLOUDS...WITH GRADUAL LOWERING OF THE
CLOUD DECK FRIDAY EVENING. THERE COULD BE SOME -SHRA OUT OF A 6-8
KFT DECK IN THE EVENING AS MOISTURE TRANSPORT WORKS WITH THE WARM
AIR ADVECTION. BETTER CHANCES OVERNIGHT FRIDAY. COULD BE A
PERIOD OF MVFR...BUT VFR LOOKS MORE PROBABLE RIGHT NOW.
WINDS WILL BECOME SOUTHWEST FRI...SHIFTING TO THE EAST IN THE
EVENING AS A WARM FRONT STARTS TO PUSH NORTH AND HIGH PRESSURE EXITS
NORTHEAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
317 AM CDT FRI MAY 25 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
339 AM PDT FRI MAY 25 2012
.SHORT AND LONG TERM DISCUSSION...
THE NEGATIVE 3 TO 4 500 MBS ANOMALY CLOSED LOW WAS NEAR THE CA/ORE
BORDER AT 09Z...AND IS FORECAST TO DROP SWD OVER INTERIOR NORCAL
TODAY. THE NEUTRAL TO SLIGHTLY POSITIVE TILT OF THE TROF AND THE
FORECAST TRACK OF THE UPPER LOW EAST OF THE COASTAL RANGE QUALIFIES
IT AS AN "INSIDE SLIDER". LITTLE RETROGRESSION IS FORECAST AS THE
LOW DROPS INTO SOCAL...THEN ROTATES EWD ON SAT... SALVAGING THE
LATTER PART OF THE BIG HOLIDAY WEEKEND.
UPPER JET ENERGY DIGGING SWD ON THE BACKSIDE OF THE CLOSED LOW IS
DRIVING THE 2ND AND STRONGER VORT MAX ALONG THE COAST THIS MORNING
BEFORE IT ROTATES INLAND BY MID DAY. THE SHOWERS AND CUMULIFORM
CLOUDINESS OFF THE COAST SHOULD ALSO BE ROTATING INLAND WITH THIS
VORT MAX BY MID DAY. THE AMSU TPW DATA SHOW THE DIGGING UPPER JET
FORCING THE HIGHER PW AIR WWD OVER THE ERN PAC...THUS THIS VORT
MAX MAY BE LOSING A LOT OF ITS MOISTURE TAP...ALTHOUGH A "TONGUE"
OF HIGHER PW IS WRAPPED NEWD FROM BAJA/SOCAL INTO THE DESERT SW.
ALTHOUGH IT MAY TAKE AWHILE...THIS PW MAY BECOME ENTRAINED INTO
THE CLOSED LOW CIRCULATION AS IT DROPS SWD THIS AFTERNOON.
MEANWHILE...THE INITIAL VORT MAX IS TRIGGERING SOME SHOWERS THAT
BEGAN AROUND KBLU BUT NOW ARE MOSTLY IN WRN NV...AND WE LOOK FOR
ANOTHER SOURCE OF LIFT MOISTURE.
THE 2ND AREA OF LARGE SCALE ASCENT IS SEEN IN THE IR IMAGERY AS
COLDER CLOUD TOPS N/NE OF THE UPPER CIRCULATION. AS THE UPPER
CIRCULATION DROPS SWD...SO SHOULD THE BAND OF ENHANCED CLOUDS AND
SHOWERS. THE HRRR-3KM PRECIP FORECAST DROPS THIS PRECIP INTO THE
SHASTA CO AREA BY 18Z FRI. SINCE THE HRRR IS ONLY AN HOURLY 13 HR
FORECAST WE EXTRAPOLATE THAT AS THE UPPER LOW DROPS SWD TODAY...SO
WILL THE BAND OF SHOWERS THIS AFTERNOON AND EVENING.
ALTHOUGH THE STRONG VORT MAX WILL BE SOUTH OF OUR FORECAST AREA FRI
AFTERNOON...THE 5H COLD POOL AROUND -24 DEG C WILL BE OVER MUCH OF
THE AREA RESULTING IN STEEP LAPSE RATES ABOUT 8-10 DEG C/KM UP TO
500 MBS. THE EQUILIBRIUM LEVEL (EL) BARELY IS FORECAST TO REACH 20
KFT FRI AFTERNOON SO THESE WILL BE VERY LOW-TOPPED CELLS. THE HIGHER
SHEAR VALUES ARE FORECAST TO OCCUR AT NIGHT AND GENERALLY NOT DURING
THE TIME OF CONVECTION IN THE VALLEY...OTRW WE WOULD BE EXPECTING
THE POSSIBILITY OF ROTATING CELLS. HOWEVER...THERE SHOULD BE
NUMEROUS SHOWERS AND SCATTERED TSTORMS DEVELOPING...ESPECIALLY IN
THE NE QUAD OF THE UPPER LOW AND UNDER THE COLD POOL...FROM THE
COASTAL RANGE EWD INTO THE SIERNEV.
WE ARE STILL LOOKING AT SEVERAL TENTHS OF AN INCH OF QPF OVER THE
HIGHER TERRAIN...AND THAT COMBINED WITH LOWER THAN NORMAL SNOW
LEVELS DOWN TO 5 KFT OR SO...SOME ACCUMULATING SNOW IS EXPECTED OVER
THE HIGHER TERRAIN THROUGH FRI EVENING. 2-6 INCHES OF SNOW IS
FORECAST TO FALL DURING THE PERIOD ABOVE 6000 FT. THE WARM GROUND IS
EXPECTED TO MELT SOME SNOW ESPECIALLY AT THE LOWER SNOW LEVEL
ELEVATIONS. CYCLONIC FLOW IS FORECAST TO LINGER OVER THE SIERNEV
INTO SAT KEEPING THE CHANCE OF LIGHT SHOWERS GOING.
MAX TEMPS WILL BE SOME 15 DEG BELOW NORMAL TODAY...BUT WE HAVEN`T
GONE AS FAR AS FORECAST RECORD LOW MAX TEMPS AT OUR MAIN CLIMO
SITES. USUALLY...THE MAY SUN WILL SHINE LONG ENOUGH DUE TO BREAKS IN
THE CONVECTIVE CLOUDS TO KEEP THE RECORDS FROM BREAKING.
IN THE WAKE OF TH DEPARTING CLOSED LOW ON SUN...WEAK SHORT WAVES ARE
FORECAST TO MOVE THROUGH THE WLY FLOW AND ACROSS NORCAL SUN/MON.
THESE SYSTEMS MAY SPREAD SOME CLOUDINESS OVER NORCAL AT TIMES...BUT
ANY PRECIP IS EXPECTED TO REMAIN NORTH OF OUR AREA AT THIS TIME.
NEAR NORMAL TEMPS ARE EXPECTED TO RETURN BY SUN AND THE MEMORIAL
DAY HOLIDAY.
5H HEIGHTS ARE FORECAST TO REBUILD OVER THE WRN STATES FOR THE
MIDDLE OF NEXT WEEK WITH A RETURN TO ABOVE NORMAL TEMPS WITH MAXES
IN THE 90S IN THE VALLEY. AS THE RIDGE AXIS SHIFTS EWD INTO THE
INTERMOUNTAIN W...THE MID LEVEL FLOW MAY BACK OVER THE SIERNEV FOR
SOME AFTERNOON CONVECTION NEXT FRI. JHM
&&
.AVIATION...
UPPER LOW DROPPING INTO THE NORTH STATE TODAY WILL BRING CLOUDS
AND SCATTERED SHOWERS TO MOST OF INTERIOR NORTHERN CALIFORNIA.
GENERALLY REMAINING VFR TAF SITES BUT OCCASIONAL MVFR NORTHERN
SACRAMENTO VALLEY THROUGH THIS AFTERNOON WITH CIGS AOB030.
IFR/OCCASIONAL MIFR OVER MOUNTAINS TODAY WITH OCCASIONAL SHOWERS.
SNOW LEVEL AROUND 050 AGL. NORTH TO WEST WINDS TODAY 5 TO 15 KT
WITH GUSTS TO 25 KNOTS OVER RIDGES.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM PDT THIS EVENING ABOVE 6000
FEET FOR THE WEST SLOPE NORTHERN SIERRA NEVADA...WESTERN PLUMAS
COUNTY/LASSEN PARK.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
650 AM CDT FRI MAY 25 2012
.SHORT TERM.../TODAY/
MAIN CONCERN TODAY WILL BE PRECIP TRENDS. ACTIVE JET CONTINUES TO
ROUND PACIFIC NW UPPER LOW AND EXTENDS INTO THE NRN PLAINS. WATER
VAPOR IMAGERY SHOWS JET SEGMENT AND SUBTLE ENHANCEMENT OF UVM
EJECTING FROM UT INTO NE/KS...WHICH HAS AIDED WEAK SRN NE ELEVATED
CONVECTION. PRECIP ALSO NICELY REFLECTED IN RAP 305K ISENT SFC WITH
MOISTURE CONVERGENCE AND LOWER RH FOCUSED INTO THIS AREA. WEAK
KINEMATIC FORCING WILL PERSIST AND LIFT NWD WITH JET AND BUILDING
RIDGE LATER TODAY AND WILL ALSO DRAW INCREASED THERMODYNAMIC FORCING
NWD ON LEADING EDGE OF MUCAPE/ELEVATED INSTABILITY GRADIENT.
PHASING OF UVM AND ADEQUATE MOISTURE SEEMS WEAK THIS MORNING...SO
NOTHING MORE THAN SLIGHT POPS SW IN CASE SOMETHING DRIBBLES INTO
FORECAST AREA. HOWEVER FORCING MECHANISMS BECOME BETTER ORGANIZED
BY AFTERNOON WITH 00Z ECMWF/GFS BOTH SHOWING SHARPLY INCREASED
H85/H7 THETA-E ADVECTION INTO IA BY 00Z. THIS WILL LIKELY DEVELOP
ADDITIONAL SCATTERED SHOWERS/THUNDERSTORMS...WHICH IS ALSO DEPICTED
BY VARIOUS WRF SOLUTIONS.
08Z SURFACE ANALYSIS SHOWS RIDGE FROM NE INTO THE HEART OF IA WHICH
WILL KEEP MIXING REDUCED TODAY. MOS GUIDANCE SEEMS TO HAVE DECENT
HANDLE ON THIS WITH HIGHS IN THE 70S OR LOWER 80S.
.LONG TERM.../TONIGHT THROUGH THURSDAY/
AS THE NEXT SHORTWAVE KICKS OUT OF THE WEST COAST TROUGH AND A
SOUTHERLY FLOW INCREASES OVER THE MIDWEST THE FRONT WHICH MOVED
THROUGH US YESTERDAY WILL LIFT NORTH OUT OF NORTHERN MISSOURI ACROSS
IOWA. 0-3KM SHEAR INCREASES THROUGH THE EVENING AS WELL AND LOOKING
AT SOUNDINGS THERE IS A 50-70KT JET OFF THE SURFACE AND IT IS
ACTUALLY TO A PRETTY GOOD DEPTH. STORMS THAT FIRE WILL EASILY HAVE
VERY ROBUST UPDRAFTS. EXPECTING MORE OF AN ELEVATED HAIL EVENT WITH
THE STORMS THIS EVENING AND LOCATION WILL DEPEND ON WHERE THE FRONT
WILL BE. CONVECTION MAY LINGER ACROSS CENTRAL IOWA INTO SATURDAY
MORNING THOUGH THAT FRONT WILL CONTINUE TO SHIFT EAST SO THE MAIN
AREA OF CONCERN FOR THUNDER WILL BE NORTHERN IOWA.
FOR THE REMAINDER OF SATURDAY AND SATURDAY NIGHT A STOUT CAP WILL BE
IN PLACE AND WE ARE LOOKING FOR LITTLE IN THE WAY OF CONVECTION IN
THE CWA...ASSUMING THE FRONT REMAINS IN SOUTHERN MN. SOUTHERLY
WINDS WILL BE ON THE INCREASE AGAIN ON SATURDAY POSSIBLY HAMPERED BY
CLOUD COVER AT LEAST INITIALLY. I DONT/ THINK WE WILL MIX AS GOOD
AS WE COULD.
FOR SUNDAY WE WILL SEE LESS CLOUD COVER AND A STRONGER SOUTH WIND
OVER THE AREA. I EXPECT THE CWA TO ONCE AGAIN BE CAPPED UNTIL A
COLD FRONT BEGINS TO PUSH INTO THE AREA LATE IN THE DAY AND
ESPECIALLY SUNDAY NIGHT. THERE WILL BE DEEP LAYER SHEAR WITH THIS
AND A STRONG JET AS A SHORT WAVE OVER THE PLAINS MOVES INTO WESTERN
IOWA. WE COULD SEE ALL MODES OF SEVERE WEATHER WITH THIS FRONT
THOUGH TIMING ISN/T THE BEST. DYNAMICALLY THOUGH I DONT THINK IT
WILL MATTER. WE WILL HAVE A LOT OF INSTABILITY WITH CAPES IN EXCESS
OF 1500 J/KG ADVECTING INTO THE AREA AND THE AFOREMENTIONED SHEAR.
SIMILAR TO THE OTHER NIGHT IT WILL LIKELY EVOLVE FROM SUPERCELLS
PRODUCING VERY LARGE HAIL AND SOME TORNADOES TO A LINEAR SYSTEM WITH
WIND DAMAGE PROBABLY OVER A FAIR PART OF THE CWA.
THE FRONT WILL HEAD EAST DURING THE DAY MONDAY ENDING THE THREAT FOR
STORMS BUT USHERING SOME PRETTY COOL AIR FOR EARLY NEXT WEEK.
BEYOND THAT THERE IS SUFFICIENT DISAGREEMENT ON A MID WEEK SHORTWAVE
THAT WILL BRING SHOWERS AND SOME THUNDER TO THE AREA BUT SHEAR IS
WEAK AND WE WILL BE MORE STABLE. KEPT THE POPS WE HAD GOING FOR
CONSISTENCY SAKE BUT TIMING AND LOCATION WILL NEED TO BE ADDRESSED
IN LATER FORECASTS.
&&
.AVIATION...25/12Z
ELEVATED SHOWERS WILL CONTINUE TO MOVE FROM NE INTO IA THIS
MORNING...POSSIBLY AFFECTING KDSM AT TIMES. COVERAGE AND INTENSITY
OF CONVECTION WILL INCREASE LATER TODAY AND TONIGHT HOWEVER. WITH
LITTLE CONFIDENCE IN TIMING OR LOCATION DETAILS AS OF YET HAVE
NOTHING BEYOND AN EXTENDED PERIOD OF VCSH WORDING WITH VFR CIGS.
THUNDER AND MVFR OR LESS CIGS ARE CERTAINLY POSSIBLE HOWEVER BUT NOT
INCLUDED UNTIL TRENDS BECOME CLEARER.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/AVIATION...BSS
LONG TERM...FAB
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
706 AM CDT FRI MAY 25 2012
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 341 AM CDT FRI MAY 25 2012
FOR THIS AFD UPDATE, NOT TOO MANY CHANGES WILL BE MADE. WE ALREADY
REMOVED THE CHANCE FOR THUNDERSTORMS THIS A.M., AS THE WARM FRONT
WAS WELL NORTH OF OUR AREA UP ALONG THE KANSAS/NEBRASKA BORDER.
SOME CAPE WAS STILL EVIDENT DOWN IN THE MEDICINE LODGE AREA, BUT
DO NOT SEE THE COLD FRONT SOUTH OF US MOVING NORTH TOO SOON. BY
THIS AFTERNOON, THE FRONT WILL GET PUSHED NORTH AS YET ANOTHER
WARM FRONT. THIS BOUNDARY MAY TRIGGER A FEW AFTERNOON SHOWERS AND
THUNDERSTORMS NORTH OF A SHALLOW WATER TO ASH VALLEY LINE, OR
NORTH A LINE FROM SCOTT COUNTY TO PAWNEE COUNTY. I PLACED 20 POPS
THERE AFTER 18Z. THE NAM MODEL WOULD HAVE THE PRECIP CHANCES A
TIER OF COUNTIES NORTHWARD, BUT THE HRRR MODEL IS SHOWING
CONVECTIVE INITIATION A LITTLE SOONER THAN THE NAM, AND ANOTHER
ROW OF COUNTIES SOUTHWARD. THIS SITUATION REMINDS ME OF YESTERDAY,
WHEN THE NAM PROVED TO BE MORE CORRECT (CONVECTION NORTH OF OUR
FORECAST AREA). SINCE 20 PERCENT POPS ARE CHEAP AND I DO NOT SEE
ANY REASON TO AT LEAST MENTION A SLIGHT CHANCE IN SCOTT, LANE,
NESS, RUSH AND PAWNEE, I PLANNED TO KEEP THE LOW POPS AS FAR SOUTH
AS A SCOTT TO PAWNEE COUNTY LINE. TEMPERATURES WILL RISE QUICKLY
DUE TO THE STRONG WARM AIR ADVECTION COMING NORTH FROM OKLAHOMA
BEHIND THE FRONT. DOWN NEAR THE OKLAHOMA BORDER, MAX T`S WILL
APPROACH THE CENTURY MARK. I DID NOTCH TEMPERATURES DOWN JUST A
DEGREE OR TWO, SINCE THE ADVANCEMENT NORTH OF THE WARM FRONT WILL
BE MAINLY DURING THE AFTERNOON HOURS. MAX T`S IN THE HAYS AND
WAKEENEY AREAS WILL TOP OUT IN THE UPPER 80S.
TONIGHT WILL SEE THE FRONT STRADDLING FROM NEAR SYRACUSE TO NESS
CITY AND THEN SOUTH INTO THE MEDICINE LODGE AREA. WITH THE STRONG
LOW LEVEL WARMING LEFT FROM THE DAY HEATING THE LOWER LEVELS WILL BE
PRIMED WITH INSTABILITY. THERE COULD BE A FEW STORMS NEAR AND NORTH
AND EAST OF THE FRONTAL BOUNDARY. HAD KEPT THE PREVIOUS SHIFT`S 20
POPS IN PLACE, AS THE UPPER SUPPORT MAY NOT BE SUFFICIENT FOR MANY
STORMS. WINDS TONIGHT WILL BE SOUTH AT 20 TO 25 MPH IN MOST
LOCATIONS HELPING TO ADVECT HIGHER DEW POINTS NORTH INTO SOUTHWEST
KANSAS. WINDS THEN WILL BECOME 10 TO 15 MPH AFTER MIDNIGHT, STILL
FROM THE SOUTH. MINIMUM TEMPERATURES TONIGHT SHOULD BE RELATIVELY
WARM, RANGING FROM THE LOWER 60S IN THE HAMILTON, STANTON, AND
MORTON COUNTY AREAS TO THE LOWER 70S IN THE PRATT, BARBER, AND
COMANCHE COUNTY AREAS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 354 AM CDT FRI MAY 25 2012
AN ACTIVE PERIOD IS UPON US FOR THE NEXT SEVERAL DAYS. THE
CONTINUING ISSUES OF WARM TEMPERATURES, WIND, CONVECTIVE CHANCES
REMAIN CHALLENGES FOR THE MEDIUM RANGE.
THE FIRST PROBLEM WILL BE WHERE AND WHEN ISOLATED THUNDERSTORMS MAY
OCCUR DURING THE DAY ON SATURDAY. THE OVERALL PATTERN IS ONE OF MID
LEVEL RIDGING WITH WESTERN AND CENTRAL KANSAS ON THE BACK SIDE OF THE
UPPER RIDGE. AT THIS TIME, THE MODELS THAT HAVE THE BEST AGREEMENT
APPEAR TO BE THE ECMWF AND THE NAM. THESE TEND TO PRODUCE
PRECIPITATION ALONG A DIFFUSE DRYLINE FEATURE, GENERALLY ALONG A
ROUGH HAYS TO MEADE LINE AND EASTWARD. MOST OF THIS CONVECTION WOULD
BE DISCREET WITH GOOD SEVERE HAIL POTENTIAL GIVEN THE INSTABILITY
POTENTIAL. THE GFS IS VERY DIFFERENT, HANGING THE DRYLINE/TROUGH
MUCH FARTHER WEST NEAR THE COLORADO LINE AND FOCUSING CONVECTION
LATE DAY OVER THE HIGHER TERRAIN.
SURFACE WINDS MAY ALSO BE A CHALLENGE TO FORECAST ON SATURDAY. THE
INTENSITY OF THE SURFACE LOW WILL BE A PRIMARY DETERMINANT OF THE
POTENTIAL. THE ECMWF INDICATES A 10 MB GRADIENT ACROSS THE AREA. THE
UPPER JETS DON`T REALLY APPEAR TO BE PHASED FOR THE GREATEST MIX
DOWN POTENTIAL THOUGH. THE GFSMOS IS SHOWING VERY STOUT 40-45 KNOT
SUSTAINED WIND SPEEDS, BUT MODELS ARE NOWHERE NEAR THIS SOLUTION AS
OF YET. A WINDY DAY WITH SUSTAINED WINDS IN EXCESS OF 30 MPH CAN BE
EXPECTED THOUGH WITH GOOD POTENTIAL FOR FREQUENT 40+ KT GUSTS.
WARM TEMPERATURES IN THE UPPER 90S ARE STILL ANTICIPATED GIVEN THE
WARM ADVECTION AND BOUNDARY LAYER AIRMASS - WITH A WEAK DOWNTREND IN
HIGHS THROUGH THE WEEKEND.
IN THE MEANTIME, AN IMPRESSIVE MID LEVEL TROUGH WITH EMBEDDED CLOSED
CIRCULATION WILL BE SWINGING THROUGH THE WESTERN STATES. A POTENT
JET STREAK IS MODELED TO MOVE THROUGH THE SOUTHERN ROCKIES AND
CENTRAL HIGH PLAINS REGIONS ON SUNDAY. THE TROUGH AND JET WILL ACT
TO INCREASE INSTABILITY, AS WELL AS LIFT THE DRYLINE/SURFACE
MOISTURE CONVERGENCE ZONE FARTHER NORTH AND EAST INTO THE AFTERNOON.
BETWEEN THE GFS/ECMWF AND THE NAM, THE AREAS OF BEST SEVERE WEATHER
THREAT APPEARS TO BE ACROSS NORTHWEST AND NORTH CENTRAL KANSAS. A
GOOD PORTION OF THE DODGE CITY FORECAST AREA SHOULD ALSO BE UNDER A
SUPERCELL HAIL, WIND AND TORNADO THREAT . THE SURFACE DRYLINE/WARM
SECTOR COULD EASILY BE ACTIVE ON THIS DAY. THE DEEP MEAN STORM
MOTIONS APPEAR STRONG AND PARALLEL TO THE DRYLINE WHICH COULD IMPLY
A FEW TORNADOES MIGHT BE MORE LIKELY.
WITH THE STRONG UPPER JET PRESENT, AND SOME RESIDUAL INSTABILITY
LIKELY STILL AROUND THE CENTRAL PLAINS, SHOWERS AND A FEW ROUNDS OF
THUNDERSTORMS MIGHT STILL OCCUR INTO SUNDAY NIGHT, WITH A DOWNTREND
INTO MONDAY MORNING. NORTHERLY SURFACE WINDS SHOULD BECOME DOMINANT
ON MONDAY WITH BREEZY TO WINDY CONDITIONS. BY TUESDAY, THE SURFACE
WINDS TURNS BACK AROUND INTO A WEAK UPSLOPE PATTERN AS ZONAL FLOW
ALOFT DEVELOPS AND STRONG HIGH PRESSURE BUILDS SOUTHWARD ACROSS THE
NORTHERN PLAINS. AT THAT POINT, THE MESOSCALE APPEARS TO ALLOW FOR
MOISTURE RETURN INTO THE CENTRAL PLAINS ALONG A MEAN BOUNDARY OVER
CENTRAL KANSAS AND OKLAHOMA. AS A RESULT THE ALLBLEND FORECAST
METHODOLOGY PRODUCES ABOUT 20 TO 40 PERCENT PRECIPITATION CHANCES;
INCREASING TUESDAY THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 705 AM CDT FRI MAY 25 2012
A WEDGE OF SURFACE HIGH PRESSURE OVER NEBRASKA THIS MORNING IS THE
CAUSE OF THE NORTHEASTERLY SURFACE WINDS ACROSS ALL OF WESTERN AND
CENTRAL KANSAS THIS MORNING. THESE SURFACE WINDS WILL BEGIN TO VEER
WITH TIME AS THE HIGH SLIDES EASTWARD AND SURFACE WARM FRONT LIFTS
NORTHWARD LATE THIS AFTERNOON. THE NAM MODEL FORECAST SOUNDING
INDICATE CLOUD BASED WILL GENERALLY BE LIFTING THOUGH THE DAY AS THE
WARMER AIR INVADES THE AREA. CONVECTIVE CHANCES ARE MINIMAL AND
THE SURFACE FRONT AND LOW ENOUGH TO NOT WARRANT MENTION IN ANY
TERMINALS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 96 68 98 68 / 10 10 30 30
GCK 94 65 97 67 / 10 10 20 20
EHA 97 63 96 65 / 0 10 20 20
LBL 99 66 97 67 / 10 10 30 30
HYS 88 66 98 70 / 20 20 30 30
P28 94 71 97 70 / 20 20 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURKE
LONG TERM...RUSSELL
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS ELKO NV
313 AM PDT FRI MAY 25 2012
.SYNOPSIS...A LOW PRESSURE SYSTEM WILL MOVE INTO THE GREAT BASIN
TODAY BRINGING IN COOLER AIR...SHOWERS...AND SOME THUNDERSTORMS.
SHOWERS WILL SPREAD ACROSS MOST OF THE GREAT BASIN TODAY. AS THIS
LOW MAKES ITS WAY THROUGH THE STATE THIS WEEKEND...THE MOUNTAINS
OF NORTHERN AND EAST CENTRAL NEVADA WILL ACCUMULATE SEVERAL INCHES
OF SNOW. SHOWERS WILL BE TAPERING OFF SUNDAY AND A WARMING TREND
WILL BEGIN ON MEMORIAL DAY.
&&
.SHORT TERM...TODAY THROUGH SATURDAY.
OVERVIEW. SHOWERS HAVE BEEN TAPERING OFF OVER NORTHERN NEVADA THIS
MORNING. SOME STRONGER SHOWERS BEGAN DEVELOPING OVER WESTERN
NEVADA AFTER MIDNIGHT...RENO WFO HAD SNOW SHOWERS WITH LIGHT
ACCUMULATIONS ON GRASSY AREAS AS RNO AIRPORT TEMPERATURES WERE IN
THE 40S WITH LIGHT RAIN. MODELS ARE INDICATING THE CENTER OF THE
ELONGATED INCOMING UPPER LOW TO BE OVER THE CA/OR BORDER AT THIS
TIME. THE RUC AND NAM 09Z TIMING SEEMS ABOUT RIGHT WHILE THE
GFS/ECMWF MAY BE A LITTLE LATE ON THE TIMING. THE ECMWF AND THE
NAM BOTH DEVELOP SHOWERS WHERE THEY ARE OCCURRING AT THIS TIME
HOWEVER A TAD LATE. THINK THE ENERGY AROUND THIS SYSTEM IS BEING
UNDERPLAYED. THAT BEING SAID...CANNOT GET MUCH BETTER AGREEMENT
WITH THE TRACKING OF THIS FEATURE THROUGH SATURDAY EVENING.
TODAY AND TONIGHT. THE MODEL DEPICTION OF THE UPPER JET FLOW IS
LEANING TOWARDS BALANCE AT THIS TIME AND THE CORE IS OVER CENTRAL
NEVADA THIS MORNING. HOWEVER FURTHER DIGGING IS POSSIBLE AS THE
WESTERN CORE IS WILL REMAIN SLIGHTLY STRONGER TODAY AND KEEP THE
LOW STRETCHED...ALLOWING FOR DELAYED PRECIPITATION PROGRESS INTO
CENTRAL NEVADA. CONDITIONS WILL BE VERY DRY AGAIN TODAY IN CENTRAL
NEVADA. HAVE ISSUED A RED FLAG WARNING FOR FIRE ZONES 455 AND 457
AND A WIND ADVISORY FOR ZONES 035 AND ZONES 041. WINDS WILL BE
STRONGEST OVER NORTHEASTERN NYE COUNTY AND SOUTHEASTERN PORTION OF
WHITE PINE COUNTY. THINKING GREAT BASIN PARK AREA WILL SEE
STRONGEST WINDS BUT ELY GUIDANCE HAS INCREASED THE LAST TWO MODEL
RUNS. WIND GUSTS UP TO 50 MPH EXPECTED...THE GREAT BASIN PARK BASE
COULD GET OVER 50 MPH. MOST OF THE QUANTIFIABLE PRECIPITATION
SHOULD BE OVER HUMBOLDT COUNTY TODAY AS THE UPPER ENERGY PULLS THE
MOISTURE AWAY FROM MOST OF THE CWFA. SNOW LEVELS WILL BE AROUND
6500 FEET OVER NORTHWEST NEVADA AND ANY THUNDERSTORMS THAT DEVELOP
SHOULD BE CONFINED TO THE NORTH. THE MU CAPE IS LOW SO DO NOT
EXPECT THUNDERSTORMS TO MAINTAIN OVERNIGHT AS THE CENTER OF THE
LOW MOVES INTO NEVADA.
SATURDAY. THE CENTER OF THE UPPER LOW IS PURPORTED TO MOVE
THROUGH TONOPAH AND THEN LIFT NORTH AND TRACK THROUGH NE NV. AN
INTENSE PRECIPITATION CORE IS PROPOSED BY THE MODELS STRETCHING
FROM TONOPAH THROUGH NORTHERN ELKO COUNTY. THINK THUNDERSTORM
DEVELOPMENT WILL BE EAST OF THIS CORE WHERE THE MOST INSTABILITY
IS APPEARING NEAR THE CENTER OF THE STACKED LOW AND UNDER THE
110KT JET FEATURE.
A MIX OF RAIN AND SNOW IS POSSIBLE BELOW 6500 FEET HOWEVER NO
ACCUMULATIONS ARE EXPECTED BELOW THAT LEVEL. THE RUBY MOUNTAINS
COULD ACCUMULATE 4-6 INCHES OF NEW SNOW.
NOT EXPECTING TRAVEL PROBLEMS AS THE SNOW WILL BE CONFINED TO THE
HIGHEST ELEVATIONS...BUT RECREATION ISSUES WILL ARISE FOR PERSON
OUTDOORS ON THIS HOLIDAY WEEKEND.
.LONG TERM...SATURDAY NIGHT THROUGH NEXT THURSDAY. QUIET AND DRY
UNEVENTFUL WEATHER THROUGH NEXT WEEK...LITTLE TO DISCUSS. COOL NW
FLOW SUNDAY BEHIND DEPARTING STORM SYSTEM WITH AFTERNOON HIGHS
RECOVERING TO THE 60S. FLOW TRANSITIONS TO ZONAL MEMORIAL DAY AND
TUESDAY...FOLLOWED BY 500 MB RIDGING WEDNESDAY AND THURSDAY. 00Z
ECMWF/GFS BOTH FORECAST PEAK HIGH PRESSURE RIDGE INTENSITY AT 586 DM
ACROSS NEVADA ON THURSDAY. SUNNY DAYS AND CLEAR NIGHTS WITH A
WARMING TREND AND FEW CLOUDS. ALL POP GRIDS ZERO MONDAY THROUGH
THURSDAY. NEXT FRIDAY...AFTERNOON TEMPERATURES WILL APPROACH 90 IN
THE SW FLOW BEHIND THE DEPARTING RIDGE AXIS. BT
&&
.AVIATION...STRONG STORM SYSTEM IN NORTHERN CALIFORNIA AT 12Z FRI
WILL MOVE TO NORTHERN NYE COUNTY 12Z SAT. MID CLOUD DECKS WILL
THICKEN AND LOWER ACROSS NEVADA THROUGH 00Z. -SHRA MOST LIKELY AT
KWMC/NW NEVADA THROUGH 00Z. -SHRA/TSRA WILL EXPAND ACROSS NEVADA
00-12Z SAT WITH CEILINGS LOWERING TO MVFR AT TIMES.
PRIMARY IMPACT TO AVIATION OPERATIONS IS EXPECTED 12Z SAT-00Z SUN
WITH NUMEROUS -SHRA AND ISOLATED -TSRA. CIGS/VIS WILL LOWER TO MVFR
AT TIMES WITH MOUNTAINS OBSCURED. BT
&&
.FIRE WEATHER...RED FLAG WARNING HAS BEEN ISSUED FOR ZONES 455 AND 457
THROUGH 11 PM TONIGHT FOR WIND AND RH COMBINATION CONCERN. MAIN
CONCERN IS EASTERN 457 AND SOUTHEAST 455. GREAT BASIN PARK AREA
COULD EXCEED 50 MPH AT BASE LEVEL. WINDS WILL REMAIN GUSTY PAST 11 PM
TONIGHT HOWEVER RH LEVELS WILL INCREASE THUS REDUCING CONCERN.
ISOLATED THUNDERSTORMS ARE EXPECTED OVER NORTHERN ZONES
TODAY...AND EASTERN ZONES SATURDAY. TEMPERATURES WILL DROP ENOUGH
FOR SNOW ACCUMULATIONS ABOVE ABOUT 6500 FEET. SHOWERS WILL TAPER
OFF SUNDAY. A WARMING TREND WILL BEGIN ON MEMORIAL DAY AS DRIER
CONDITIONS CAN BE EXPECTED NEXT WEEK.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 11 AM THIS MORNING TO 11 PM PDT THIS
EVENING FOR NORTHEASTERN NYE COUNTY...NORTHWESTERN NYE COUNTY...
SOUTHERN LANDER COUNTY AND SOUTHERN EUREKA COUNTY...WHITE PINE
COUNTY.
WIND ADVISORY FROM 11 AM THIS MORNING TO 11 PM PDT THIS EVENING
FOR NORTHEASTERN NYE COUNTY...WHITE PINE COUNTY.
&&
$$
92/99/99/92
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1103 AM EDT FRI MAY 25 2012
.SYNOPSIS...
A FRONTAL BOUNDARY WILL APPROACH THE REGION TODAY. AHEAD OF THE
FRONT TEMPERATURES WILL BE WARM THIS AFTERNOON. LOOK FOR AN
INCREASING CHANCE OF SHOWERS OR THUNDERSTORMS THIS
AFTERNOON...ESPECIALLY CLOSER TO THE NEW YORK BORDER. ANY STORMS
WILL BE FAST MOVING AND COULD BRING WITH THEM SOME BRIEF GUSTY
WINDS. A RIDGE OF HIGH PRESSURE WILL BRING ABOVE NORMAL
TEMPERATURES THIS HOLIDAY WEEKEND...WITH MANY LOCATIONS
APPROACHING 90 DEGREES ON MEMORIAL DAY. A COLD FRONT WILL CROSS
THE REGION LATE MONDAY INTO TUESDAY ENDING THIS PERIOD OF HIGHER
HEAT AND HUMIDITY AND BRINGING AN INCREASING CHANCE OF SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK FRONTAL BOUNDARY APPROACHING FROM THE WEST TODAY. AHEAD OF
THIS THE REGION IS WARM AND MOIST. AFTERNOON CAPES QUITE HIGH AND
WITH THE APPROACHING BOUNDARY SHOWERS AND THUNDERSTORM DEVELOPMENT
IS LIKELY. STORMS WILL BE FAST MOVING THOUGH SO ANY HEAVY RAINS
SHOULD BE SHORT LIVED WITH THE THREAT BEING MORE GUSTY WINDS AND
ISOLATED HAIL. MODELS DO SHOW THE BEST DYNAMICS NORTH OF THE
BORDER IN NYS...THOUGH 4KM NAM AND HRRR SHOWS CONVECTION FORMING
IN OUR CWA. DRIER AIR ENTERS CWA TONIGHT AS UPPER LEVEL HEIGHTS
BUILD.
&&
.SHORT TERM /SATURDAY/...
STATIONARY BOUNDARY SHOULD LIE SOMEWHERE ACROSS THE CWA ON
SATURDAY...WITH WARM AIR CONTINUING TO ADVECT IN THROUGHOUT THE
DAY. EXPECT A FEW AFTERNOON SHOWERS POSSIBLE AS A WEAK LEE TROUGH
LIFTS THROUGH LATE SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
ANOTHER 2-3 DAYS OF VERY WARM AND HUMID CONDITIONS ARE EXPECTED
ACROSS CENTRAL PA WITH ENSEMBLE MAXES WARMING WELL THROUGH THE 80S
SUNDAY THROUGH TUESDAY. A SLOW MOVING FRONT IS FORECAST TO DEPRESS
UPPER LEVEL HEIGHTS BY THE MIDDLE OF NEXT WEEK...ALLOWING
TEMPERATURES AND HUMIDITY TO ADJUST BACK TO NEAR NORMAL LEVELS FOR
THE SECOND HALF OF NEXT WEEK.
REGARDING RAINFALL...WHILE AN AFTERNOON OR EVENING SHOWER OR
THUNDERSTORM IS POSSIBLE EACH DAY...THE BEST CHANCES WILL OCCUR ON
TUESDAY AFTERNOON AND NIGHT AS A COLD FRONT CROSSES THE AREA. A
WAVE MAY FORM ALONG THE STALLING FRONT AND BRING ADDITIONAL
SHOWERS TO THE AREA NEXT FRIDAY.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
A PRETTY REDUNDANT PATTERN WILL REMAIN IN PLACE TODAY WITH VFR
REGION WIDE. ANOTHER AFTERNOON OF CONVECTION IS POSSIBLE..THOUGH
THE MAIN FOCUS AREA TODAY WILL BE THE NW MTNS AND POSSIBLE THE
LAUREL HIGHLANDS. SOME OF THESE SHOWERS AND STORMS COULD SPILL TO
THE CENTRAL PA REGION...AS THE TROUGH MOVES TO THE NE. MVFR CIGS
AND VSBYS POSSIBLE BRIEFLY IN ANY STORMS...WITH STORMS ENDING AROUND
SUNSET. ANOTHER ROUND OF FOG AND STRATOCU INTO SATURDAY
MORNING...WITH THE MAIN AREAS BEING VCTY OF MDT...LNS AND IPT.
OUTLOOK...
SAT-MON...MAINLY VFR. A CHC OF AN AFTERNOON OR EVENING
SHOWER/STORM CAUSING LOCALIZED REDUCTIONS.
TUE...MAINLY VFR. CHC OF SHOWERS AND STORMS LATE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROSS
NEAR TERM...ROSS
SHORT TERM...ROSS
LONG TERM...DEVOIR/MARTIN
AVIATION...ROSS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
635 AM CDT FRI MAY 25 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
317 AM CDT FRI MAY 25 2012
MAIN FORECAST CONCERNS ARE ON CONVECTIVE POTENTIAL THROUGHOUT...
ALONG WITH ANY SEVERE WEATHER CONCERNS.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED DEEP TROUGHING OVER NORTHERN CALIFORNIA (2-2.5 STANDARD
DEVIATIONS BELOW NORMAL)...RIDGING BUILDING UP OVER THE CENTRAL
PLAINS...AND A POTENT SHORTWAVE TROUGH MOVING THROUGH UPPER
MICHIGAN. THE FORECAST AREA LIES IN SUBSIDENCE IN THE WAKE OF THE
SHORTWAVE TROUGH...WHICH HAS RESULTED IN DRYING AND CLEARING SKIES.
00Z MPX SOUNDING SHOWED SOME OF THE DRYING COMING IN ABOVE 700MB.
SURFACE COLD FRONT ASSOCIATED WITH THE POTENT SHORTWAVE EXTENDS FROM
LAKE MICHIGAN...SOUTHWEST TO SPRINGFIELD MO...THEN TURNS INTO A WARM
FRONT CONNECTING TO A LOW IN NORTHEAST NEW MEXICO. SOUTH OF THAT
WARM FRONT...DEWPOINTS ARE NEAR 70. COMPARE THESE TO THE AROUND 50
DEWPOINTS THAT HAVE ADVECTED IN BEHIND THE FRONT OVER THE FORECAST
AREA.
TODAY AND TONIGHT...UPPER TROUGHING OVER NORTHERN CALIFORNIA IS
FORECAST TO DIG SOUTHWARD THROUGH THE STATE...CAUSING SIGNIFICANT
HEIGHT RISES AT 500MB UP AND DOWN THE MISSISSIPPI RIVER VALLEY.
BETWEEN 12Z TODAY AND 12Z SATURDAY...500MB HEIGHTS RISE 180 METERS
AT LA CROSSE. ACCOMPANYING THESE SIGNIFICANT HEIGHT RISES WILL BE AN
INTENSIFYING LOW LEVEL JET OVER THE PLAINS...PROPELLING THE WARM
FRONT IN OKLAHOMA NORTHWARD AT A RAPID CLIP. BY 12Z SATURDAY...VERY
GOOD AGREEMENT EXISTS THAT THE WARM FRONT SHOULD BE APPROACHING I-80
IN IOWA. THE MAIN CONCERN IS PRECIPITATION CHANCES GIVEN SUCH RAPID
CHANGES GOING ON. EXPECT THE MORNING TO REMAIN DRY WITH THE FORECAST
AREA STILL FEELING SUBSIDENCE IN THE WAKE OF LAST NIGHTS SHORTWAVE
TROUGH. DURING THE AFTERNOON...INCREASING 800MB TO 700MB MOISTURE
TRANSPORTED IS NOTED...WHICH WILL AT A MINIMUM CAUSE AN INCREASE IN
ALTOSTRATUS. SOME MODELS HAVE SUGGESTED SOME LIGHT SHOWERS
DEVELOPING OUT OF THESE CLOUDS...MOSTLY WEST OF THE MISSISSIPPI
RIVER AND EVEN THAT MOSTLY WEST OF THE FORECAST AREA. FORECAST
SOUNDINGS DO DEPICT QUITE A BIT OF DRY AIR BELOW THE ALTOSTRATUS...
WHICH MAY ABSORB SOME OF THE RAIN. THEREFORE...HAVE KEPT ANY PRECIP
TO SPRINKLES THIS AFTERNOON...AND ONLY WEST OF THE MISSISSIPPI
RIVER. THINGS GET A BIT TRICKY TONIGHT. AS THE LOW LEVEL JET AND
MOISTURE TRANSPORT INCREASES...NUMEROUS CONVECTION IS LIKELY TO
DEVELOP OVER IOWA NORTH OF THE WARM FRONT. THE QUESTION IS WILL IT
TURN INTO AN MCS OR NOT...SINCE THAT WOULD LIKELY SLOW THE WARM
FRONTS NORTHWARD PROGRESS FOR LATER IN THE FORECAST...AND IMPACT
HOW MUCH PRECIPITATION IMPACTS THE AREA GIVEN NORTHWEST TO SOUTHEAST
ORIENTED CORFIDI VECTORS. MAIN UPPER JET IS WELL TO THE NORTH OVER
NORTHERN MINNESOTA...SO NO UPPER DIVERGENCE HELP. 500MB HEIGHTS ARE
RISING WITH NO SHORTWAVE EVIDENT...SO NO SUPPORT THERE. IT SEEMS THE
ONLY THING GOING FOR AN MCS IS THE MOISTURE TRANSPORT...WHICH IS
BROAD. THEREFORE...THINK WHAT MOST OF THE MODELS DEPICT WITH QPF...
I.E SHOWERS AND THUNDERSTORMS...GRADUALLY LIFTING NORTH WITH THE
FRONT SEEMS REASONABLE. WITH WARM CLOUD DEPTHS APPROACH 3.5-4
KM...ANY SHOWERS LIKELY TO PRODUCE HEAVY RAIN...THOUGH LACK OF AN
MCS OR STATIONARY BOUNDARY PREVENTS ANY FLOOD CONCERN AT THIS TIME.
ALTHOUGH 1-6 KM SHEAR IS 40 OR MORE KNOTS...SKINNY CAPE AND HIGH
FREEZING LEVELS MAY KEEP THE MAIN THREAT BESIDES RAIN TO GUSTY WINDS
FROM THE STORMS. COOLER DAY ON TAP TODAY WITH 850MB TEMPS OF 8-10C
AND INCREASING AFTERNOON CLOUDS. HIGHS IN THE 70S SEEM REASONABLE.
WENT WITH A BLEND OF GUIDANCE FOR LOWS TONIGHT.
SATURDAY THROUGH SUNDAY...WARM FRONT LOOKS TO CONTINUE ITS NORTHWARD
PROGRESS AS THE TROUGHING IN CALIFORNIA LIFTS INTO THE HIGH PLAINS
LATE SUNDAY. WARM FRONT SHOULD APPROACH I-90 BY 00Z SUNDAY. SOUTH OF
THIS FRONT...A PLUME OF HOT AND HUMID AIR REFLECTED BY 850MB TEMPS
OF 20C PLUS...AS WELL AS THOSE DEWPOINTS SEEN IN OKLAHOMA...WILL
ADVECT IN. THEREFORE...PLENTIFUL CAPE IS LIKELY ON AND ADVECTING
NORTH WITH THE FRONT. PROBLEM WE MAY HAVE CONTEND WITH FOR
SATURDAY...AFTER ANY MORNING CONVECTION RELATED TO TONIGHT...IS
CAPPING ADVECTING NORTH OF THE FRONT AT 750MB. MLCIN VALUES ARE
SUBSTANTIAL...UPWARDS OF 200 J/KG OR SO FOR THE AFTERNOON. MUCH OF
THE MODEL QPF ON SATURDAY...PARTICULARLY AFTERNOON...SEEMS TO BE
RELATED TO BELOW THE CAP. THEREFORE...NOT SURE HOW MUCH OF IT IS
REAL. HAVE LOWERED PRECIPITATION CHANCES IN THE AFTERNOON SOUTH OF
I-94 AS A RESULT. THIS MATCHES TOO WITH THE 25.00Z REGIONAL
CANADIAN...LOCAL WRF-ARW RUN AND HIRES WRF-ARW RUN FROM NCEP. BEST
CHANCES FOR PRECIP IN THE AFTERNOON IS NORTH OF I-94 WHERE LESS CAP
EXISTS. CAP...WARM AIR AND FRONT SHOULD CONTINUE TO LIFT NORTH
ACROSS THE AREA SATURDAY NIGHT...THOUGH DID KEEP SOME CHANCES NORTH
OF I-94 WHERE RE-INVIGORATED MOISTURE TRANSPORT MAY ALLOW CONVECTION
TO GO. VERY WARM NIGHT ANTICIPATED SOUTH OF THE FRONT. SUNDAY SHOULD
BE MOSTLY DRY WITH THE HOTTEST DAY OF THE YEAR THUS FAR. 850MB TEMPS
OF 22C AT 18Z PLUS PLENTY OF SUN AND A BREEZY SOUTHWEST WIND
EXPECTED TO SUPPORT HIGHS MOSTLY IN THE 90S. STAYED AT THE HIGH END
OF GUIDANCE FOR HIGHS GIVEN THE SETUP. IF TEMPERATURES LOOK WARMER
IN LATER FORECASTS...MAY NEED TO CONSIDER A HEAT ADVISORY.
SUNDAY NIGHT...TROUGH OVER THE HIGH PLAINS IS PROGGED TO START
MOVING EAST...DRIVING A COLD FRONT TO NEAR I-35 BY 12Z MONDAY. DPVA
AHEAD OF THIS TROUGH...ALONG WITH SOME RIGHT ENTRANCE REGION
SUPPORT...LOW TO MID-LEVEL FRONTOGENESIS ALONG THE FRONT AND
INSTABILITY WILL ALL COME TOGETHER TO PRODUCE A NORTHEAST TO
SOUTHWEST ORIENTED BAND OF CONVECTION. MUCH OF THIS CONVECTION
SHOULD STAY WEST OF THE AREA IN THE EVENING...THEN MOVE INTO
SOUTHEAST MINNESOTA...NORTHEAST IOWA AND POSSIBLY NORTH CENTRAL
WISCONSIN AFTER MIDNIGHT. STORMS ARE LIKELY TO BE SEVERE WHEN THEY
INITIALLY FORM IN THE EVENING WEST OF THE AREA...AS INDICATED TOO BY
THE SPC DAY 3 OUTLOOK SEVERE PROBABILITIES. NOT SURE IF THEY WILL BE
SEVERE BY THE TIME THEY REACH THE FORECAST AREA...THOUGH...AS THE
MLCAPE REALLY TAILS OFF THROUGH THE NIGHT. THE SHEAR IS THERE...
THOUGH...ENOUGH PROBABLY TO WARRANT THE GENERAL SLIGHT RISK. WITH A
BREEZY NIGHT AND COLD FRONT/PRECIPITATION NOT COMING UNTIL
LATE...ANTICIPATING ANOTHER WARM NIGHT. LOWS MAY NEED TO BE RAISED
MORE THAN CURRENTLY FORECAST.
.LONG TERM...MONDAY THROUGH THURSDAY NIGHT
317 AM CDT FRI MAY 25 2012
AFTER A HOT SUNDAY...THE LONG TERM PERIOD FEATURES A PATTERN SHIFT
TO ONE COOLER THAN NORMAL. THIS IS IN RESPONSE TO THE TROUGHING OVER
THE NORTHERN PLAINS SUNDAY NIGHT EVENTUALLY BECOMING STUCK OVER
ONTARIO AND THE GREAT LAKES REGION. IN FACT...COME THURSDAY...THERE
IS A RE-ENFORCING POTENT SHORTWAVE DROPPING SOUTH THROUGH THE
PLAINS.
MAIN FOCUS ON THE LONG TERM PERIOD IS MONDAY...IN PARTICULAR THE
COLD FRONT COMING ACROSS THE FORECAST AREA WITH THE UPPER TROUGH.
MODELS ARE IN GOOD AGREEMENT NOW WITH THE FRONT CROSSING THE AREA
MID-DAY. HOW MUCH CONVECTION WILL BE ON THIS FRONT IS A QUESTION.
THE CONVECTION FROM SUNDAY NIGHT MAY END UP FALLING APART DUE TO
LOSS OF INSTABILITY. THEN DURING THE AFTERNOON...DEPENDING
SPECIFICALLY ON TIMING...AFTER DAYTIME INSTABILITY BUILDS THE
CONVECTION COULD FIRE ON THE FRONT AFTER IT HAS PASSED THROUGH THE
AREA. THEREFORE...PRECIPITATION CHANCES ARE ONLY 30-50 AT THIS TIME.
A FEW MODELS...THE 25.00Z ECMWF AND OUR LOCAL WRF RUN...SUGGEST THE
POTENTIAL FOR A NEARLY DRY FRONTAL PASSAGE. IF THERE IS ANY
POTENTIAL FOR SEVERE...SEEMS LIKE THAT WOULD OCCUR IN OUR FAR
EASTERN AREAS.
MAINLY DRY AND COOLER WEATHER LOOKS TO PREVAIL FOR MONDAY NIGHT
THROUGH TUESDAY NIGHT THANKS TO SUBSIDENCE ON THE BACK SIDE OF THE
UPPER TROUGH. 20-40 PERCENT CHANCES OF SHOWERS ENTER THE FORECAST
FOR WEDNESDAY THROUGH THURSDAY...ASSOCIATED WITH THAT POTENT
SHORTWAVE DROPPING DOWN THROUGH THE PLAINS. NOTE...THOUGH...THAT IT
IS ENTIRELY POSSIBLE THIS SHORTWAVE AND ITS ASSOCIATED PRECIPITATION
STAYS AWAY FROM THE AREA ...THUS ONLY THE 20-40 PERCENT VALUES.
ONE THING WE NEED TO WATCH OUT FOR TOO MAY BE FROST LATER OUT. THE
25.00Z ECMWF SHOWS 850MB TEMPS OVER TAYLOR COUNTY DROPPING TO AROUND
0C AT 12Z WEDNESDAY WITH HIGH PRESSURE BUILDING IN. RIGHT NOW NO
FROST OR EVEN TEMPERATURES CLOSE TO FROST IS IN THE FORECAST...BUT
SOMETHING AGAIN TO WATCH.
&&
.AVIATION...TODAY AND TONIGHT
635 AM CDT FRI MAY 25 2012
CLOUDS WILL BE ON THE INCREASE TODAY AS A WARM FRONT LIFTS NORTH
INTO THE UPPER MISSISSIPPI RIVER VALLEY FROM THE CENTRAL
PLAINS/MIDDLE MISSISSIPPI RIVER VALLEY. LOOK FOR A SCT-BKN CLOUD
DECK TO OVERSPREAD THE AREA THIS MORNING WITH BASES IN THE 10 TO
12 KFT RANGE. CLOUD BASES WILL LOWER THIS AFTERNOON INTO THE 6 TO
8 KFT RANGE. SHOWERS AND THUNDERSTORMS WILL DEVELOP LATE THIS
EVENING ACROSS NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN ALONG
THE WARM FRONT. THE SHOWERS AND STORMS WILL SPREAD INTO SOUTHEAST
MINNESOTA THROUGH MUCH OF SOUTHWEST WISCONSIN AFTER MIDNIGHT
TONIGHT...LIKELY IMPACTING THE TAF SITES. THE MAIN IMPACT FROM THE
STORMS WILL BE CLOUD BASES LOWERING TO AROUND 5KFT...AND GUSTY
WINDS. BRIEF HEAVY RAINFALL MAY REDUCE VISIBILITIES INTO THE MVFR
CATEGORY AT TIMES. LOOK FOR THE SHOWERS AND THUNDERSTORMS TO
PERSIST THROUGH 12Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
317 AM CDT FRI MAY 25 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
749 AM MDT FRI MAY 25 2012
.DISCUSSION...
DENSE FOG SHOULD CONTINUE AT LEAST THROUGH MIDDAY OVER AND NEAR THE
SOUTHERN LARAMIE RANGE. IN A RECENT UPDATE WENT AHEAD AND ISSUED A
DENSE FOG ADVISORY FOR THAT AREA UNTIL 18Z. ALSO MOST OF THE
SHOWERS PER AREA RADARS WERE CURRENTLY OVER THE NORTH AND WEST PARTS
OF THE CWA...SO HAVE ADJUSTED POPS THIS MORNING TO REFLECT THE
CURRENT LOCATION OF THE LIGHT RAIN. SNOW ALSO HAS BEEN FALLING
ABOVE 8500 FEET MSL IN THE MOUNTAINS AND HAVE ADDED TO THE FORECAST
FOR THE MORNING.
&&
.PREVIOUS DISCUSSION.../ISSUED AT 543 AM MDT FRI MAY 25 2012/...
.AVIATION...12Z TAFS
LATEST SATELLITE IMAGERY AND AREA METARS SHOWING LOW CLOUDS OVER
NORTHEASTERN COLORADO. WYDOT WEBCAMS SHOWING THE SOUTHERN LARAMIE
RANGE IN LOW CLOUDS AND FOG. THINKING IS...THERE WILL BE A PERIOD
THIS MORNING WHERE CHEYENNE WILL GO DOWN. THIS IS SUPPORTED BY THE
LATEST HRRR GUIDANCE. MORE WIDESPREAD AND DENSER CLOUDS EXPECTED
THIS EVENING AFTER 00Z WHEN ALL NEBRASKA PANHANDLE AIRPORTS AND
KCYS LOOK TO GO DOWN TO LIFR...PERSISTING THROUGH SATURDAY AFTERNOON.
CLAYCOMB
&&
.PREV DISCUSSION... /ISSUED 407 AM MDT FRI MAY 25 2012/
SHORT TERM...TODAY THROUGH SATURDAY.
TODAY...AS THE MODELS HAVE BEEN PREDICTING...SCATTERED TO NUMEROUS
RAIN SHOWERS HAVE MOVED INTO PORTIONS OF SOUTHEAST WYOMING AND
WESTERN NEBRASKA ASSOCIATED WITH WARM AIR ADVECTION IN THE MID
LEVELS AND POSITIVE THETA-E ADVECTION. THIS AREA OF SHOWERS IS
EXPECTED TO GRADUALLY SHIFT NORTHWARD THIS MORNING AND LIE ACROSS
OUR NORTHERN COUNTIES THIS AFTERNOON.
THIS AFTERNOON...MOIST LOW LEVEL SOUTHEAST WINDS WILL CONTINUE EAST
OF INTERSTATE 25...ADVECTING LOW LEVEL MOISTURE NORTHWESTWARD. A LOW
AND MID LEVEL THETA-E RIDGE AXIS WILL DEVELOP ALONG INTERSTATE
25...AND IF ENOUGH CLEARING OCCURS...A FEW STRONG THUNDERSTORMS MAY
ERUPT ALONG THE INSTABILITY AXIS ALONG INTERSTATE 25.
TONIGHT...THE FLOW ALOFT BACKS EVEN MORE TO SOUTH SOUTHWEST WITH
MOIST UPSLOPE SOUTHEAST WINDS CONTINUING. BOUNDARY LAYER PROGS
SUGGEST AREAS OF FOG WILL BE RELATIVELY WIDESPREAD ALONG AND EAST OF
INTERSTATE 25. LARGE SCALE SUBSIDENCE WILL LIMIT SHOWER COVERAGE...
THOUGH CANNOT RULE OUT SCATTERED SHOWERS NORTH OF A RAWLINS TO
SCOTTSBLUFF LINE CLOSER TO DEEPER MOISTURE WITH PRECIPITATION AIDED
BY UPSLOPE LIFT.
SATURDAY...STRONG NEGATIVELY TILTED SHORTWAVE ROTATES NORTHEASTWARD
ACROSS WYOMING AND COLORADO IN THE AFTERNOON INDUCING SURFACE LOW
STRENGTHENING ACROSS FAR SOUTHEAST WYOMING IN THE AFTERNOON. A WARM
FRONT WILL EXTEND EASTWARD FROM THE SURFACE LOW ACROSS WESTERN
NEBRASKA. A WELL PRONOUNCED LOW AND MID LEVEL THETA-E RIDGE AXIS
WILL DEVELOP IN THE AFTERNOON FROM DOUGLAS TO SCOTTSBLUFF. IF WARM
MID LEVEL TEMPERATURES...AND THE ASSOCIATED CONVECTIVE INHIBITION
CAN BE ELIMINATED...AND ENOUGH SURFACE HEATING OCCURS NORTH OF THE
WARM FRONT TO DIMINISH LOW CLOUDS...ISOLATED SEVERE THUNDERSTORMS
MAY ERUPT NORTH OF THE WARM FRONT IN THE AFTERNOON ROUGHLY NORTH OF
A CASPER TO SIDNEY LINE...WHERE SHEAR AND INSTABILITY PARAMETERS
WILL BE MAXIMIZED. WITH PROGGED 0 TO 3 KM HELICITY VALUES EXCEEDING
200...A FEW ROTATING STORMS WILL BE POSSIBLE NORTH OF A CASPER TO
SIDNEY LINE...WITH ISOLATED STRONG THUNDERSTORMS ELSEWHERE. DRY SLOT
AND DRY PUNCH WILL ENHANCE THUNDERSTORM DEVELOPMENT NORTH OF THE
WARM FRONT SHOULD THE CAPE BE REALIZED. WARMER MOS HIGH TEMPERATURES
PREFERRED PER 700 MB TEMPERATURE PROGS.
LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
MODELS IN FAIRLY GOOD AGREEMENT SATURDAY EVENING ON A SURFACE LOW
PRESSURE SYSTEM MOVING NORTHEAST OUT OF EASTERN COLORADO. 700MB
WINDS BEHIND THE LOW FORECAST AROUND 65KTS AS THIS LOW TRACKS
NORTH. AT THE VERY LEAST...I THINK OUR WIND PRONE AREAS ARE GOING
TO SEE WARNING LEVEL WINDS AND WENT AHEAD WITH A WATCH FOR THOSE
AREAS. PRECIP HERE IN SOUTHEAST WYOMING SHOULD COME TO AN END FROM
SOUTH TO NORTH SATURDAY NIGHT. THE EXCEPTION BEING OUT NEAR THE
SNOWY AND SIERRA MADRE RANGES WHERE BOTH THE GFS AND ECMWF KEEPS
SOME WRAP AROUND MOISTURE IN UPSLOPING CONDITIONS OUT THAT WAY.
TEMPERATURES ARE GOING TO BE SLOW TO INCREASE AS GFS KEEPS 700MB
TEMPERATURES AROUND +5C THROUGH TUESDAY. BIG WARM UP STARTS
WEDNESDAY WHEN 700MB TEMPERATURES CLIMB TO +12C. THAT WILL BE
SHORT LIVED HOWEVER...AS A SHORTWAVE TRACKS SOUTH INTO
SOUTHEASTERN WYOMING...KNOCKING 700MB TEMPERATURES BACK DOWN IN
THE SINGLE DIGITS WEDNESDAY NIGHT. UPSLOPING FLOW RETURNS THURSDAY
AS A SURFACE HIGH PARKS ITSELF OVER WEST CENTRAL NEBRASKA.
&&
FIRE WEATHER...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY AND WILL PERSIST
INTO SATURDAY. STRONG LOW PRESSURE SYSTEM IS THEN SET TO MOVE
NORTH OUT OF EASTERN COLORADO...BRINGING STRONG WINDS TO THE AREA.
FORTUNATELY...IT LOOKS LIKE AFTERNOON MIN HUMIDITIES WILL STAY
ABOVE CRITICAL THRESHOLDS...KEEPING FIRE WEATHER CONDITIONS IN
CHECK FOR THE MOST PART.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WATCH FROM 6 PM SATURDAY TO 9 AM SUNDAY FOR WYZ106-
WYZ110-WYZ116-WYZ117.
DENSE FOG ADVISORY UNTIL NOON FOR WYZ116-WYZ117.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...RUBIN
LONG TERM/AVIATION...CLAYCOMB
UPDATE...WEILAND
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
543 AM MDT FRI MAY 25 2012
.AVIATION...12Z TAFS
LATEST SATELLITE IMAGERY AND AREA METARS SHOWING LOW CLOUDS OVER
NORTHEASTERN COLORADO. WYDOT WEBCAMS SHOWING THE SOUTHERN LARAMIE
RANGE IN LOW CLOUDS AND FOG. THINKING IS...THERE WILL BE A PERIOD
THIS MORNING WHERE CHEYENNE WILL GO DOWN. THIS IS SUPPORTED BY THE
LATEST HRRR GUIDANCE. MORE WIDESPREAD AND DENSER CLOUDS EXPECTED
THIS EVENING AFTER 00Z WHEN ALL NEBRASKA PANHANDLE AIRPORTS AND
KCYS LOOK TO GO DOWN TO LIFR...PERSISTING THROUGH SATURDAY AFTERNOON.
CLAYCOMB
&&
.PREV DISCUSSION... /ISSUED 407 AM MDT FRI MAY 25 2012/
SHORT TERM...TODAY THROUGH SATURDAY.
TODAY...AS THE MODELS HAVE BEEN PREDICTING...SCATTERED TO NUMEROUS
RAIN SHOWERS HAVE MOVED INTO PORTIONS OF SOUTHEAST WYOMING AND
WESTERN NEBRASKA ASSOCIATED WITH WARM AIR ADVECTION IN THE MID
LEVELS AND POSITIVE THETA-E ADVECTION. THIS AREA OF SHOWERS IS
EXPECTED TO GRADUALLY SHIFT NORTHWARD THIS MORNING AND LIE ACROSS
OUR NORTHERN COUNTIES THIS AFTERNOON.
THIS AFTERNOON...MOIST LOW LEVEL SOUTHEAST WINDS WILL CONTINUE EAST
OF INTERSTATE 25...ADVECTING LOW LEVEL MOISTURE NORTHWESTWARD. A LOW
AND MID LEVEL THETA-E RIDGE AXIS WILL DEVELOP ALONG INTERSTATE
25...AND IF ENOUGH CLEARING OCCURS...A FEW STRONG THUNDERSTORMS MAY
ERUPT ALONG THE INSTABILITY AXIS ALONG INTERSTATE 25.
TONIGHT...THE FLOW ALOFT BACKS EVEN MORE TO SOUTH SOUTHWEST WITH
MOIST UPSLOPE SOUTHEAST WINDS CONTINUING. BOUNDARY LAYER PROGS
SUGGEST AREAS OF FOG WILL BE RELATIVELY WIDESPREAD ALONG AND EAST OF
INTERSTATE 25. LARGE SCALE SUBSIDENCE WILL LIMIT SHOWER COVERAGE...
THOUGH CANNOT RULE OUT SCATTERED SHOWERS NORTH OF A RAWLINS TO
SCOTTSBLUFF LINE CLOSER TO DEEPER MOISTURE WITH PRECIPITATION AIDED
BY UPSLOPE LIFT.
SATURDAY...STRONG NEGATIVELY TILTED SHORTWAVE ROTATES NORTHEASTWARD
ACROSS WYOMING AND COLORADO IN THE AFTERNOON INDUCING SURFACE LOW
STRENGTHENING ACROSS FAR SOUTHEAST WYOMING IN THE AFTERNOON. A WARM
FRONT WILL EXTEND EASTWARD FROM THE SURFACE LOW ACROSS WESTERN
NEBRASKA. A WELL PRONOUNCED LOW AND MID LEVEL THETA-E RIDGE AXIS
WILL DEVELOP IN THE AFTERNOON FROM DOUGLAS TO SCOTTSBLUFF. IF WARM
MID LEVEL TEMPERATURES...AND THE ASSOCIATED CONVECTIVE INHIBITION
CAN BE ELIMINATED...AND ENOUGH SURFACE HEATING OCCURS NORTH OF THE
WARM FRONT TO DIMINISH LOW CLOUDS...ISOLATED SEVERE THUNDERSTORMS
MAY ERUPT NORTH OF THE WARM FRONT IN THE AFTERNOON ROUGHLY NORTH OF
A CASPER TO SIDNEY LINE...WHERE SHEAR AND INSTABILITY PARAMETERS
WILL BE MAXIMIZED. WITH PROGGED 0 TO 3 KM HELICITY VALUES EXCEEDING
200...A FEW ROTATING STORMS WILL BE POSSIBLE NORTH OF A CASPER TO
SIDNEY LINE...WITH ISOLATED STRONG THUNDERSTORMS ELSEWHERE. DRY SLOT
AND DRY PUNCH WILL ENHANCE THUNDERSTORM DEVELOPMENT NORTH OF THE
WARM FRONT SHOULD THE CAPE BE REALIZED. WARMER MOS HIGH TEMPERATURES
PREFERRED PER 700 MB TEMPERATURE PROGS.
LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
MODELS IN FAIRLY GOOD AGREEMENT SATURDAY EVENING ON A SURFACE LOW
PRESSURE SYSTEM MOVING NORTHEAST OUT OF EASTERN COLORADO. 700MB
WINDS BEHIND THE LOW FORECAST AROUND 65KTS AS THIS LOW TRACKS
NORTH. AT THE VERY LEAST...I THINK OUR WIND PRONE AREAS ARE GOING
TO SEE WARNING LEVEL WINDS AND WENT AHEAD WITH A WATCH FOR THOSE
AREAS. PRECIP HERE IN SOUTHEAST WYOMING SHOULD COME TO AN END FROM
SOUTH TO NORTH SATURDAY NIGHT. THE EXCEPTION BEING OUT NEAR THE
SNOWY AND SIERRA MADRE RANGES WHERE BOTH THE GFS AND ECMWF KEEPS
SOME WRAP AROUND MOISTURE IN UPSLOPING CONDITIONS OUT THAT WAY.
TEMPERATURES ARE GOING TO BE SLOW TO INCREASE AS GFS KEEPS 700MB
TEMPERATURES AROUND +5C THROUGH TUESDAY. BIG WARM UP STARTS
WEDNESDAY WHEN 700MB TEMPERATURES CLIMB TO +12C. THAT WILL BE
SHORT LIVED HOWEVER...AS A SHORTWAVE TRACKS SOUTH INTO
SOUTHEASTERN WYOMING...KNOCKING 700MB TEMPERATURES BACK DOWN IN
THE SINGLE DIGITS WEDNESDAY NIGHT. UPSLOPING FLOW RETURNS THURSDAY
AS A SURFACE HIGH PARKS ITSELF OVER WEST CENTRAL NEBRASKA.
&&
FIRE WEATHER...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY AND WILL PERSIST
INTO SATURDAY. STRONG LOW PRESSURE SYSTEM IS THEN SET TO MOVE
NORTH OUT OF EASTERN COLORADO...BRINGING STRONG WINDS TO THE AREA.
FORTUNATELY...IT LOOKS LIKE AFTERNOON MIN HUMIDITIES WILL STAY
ABOVE CRITICAL THRESHOLDS...KEEPING FIRE WEATHER CONDITIONS IN
CHECK FOR THE MOST PART.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WATCH FROM 6 PM SATURDAY TO 9 AM SUNDAY FOR WYZ106-
WYZ110-WYZ116-WYZ117.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...RUBIN
LONG TERM/AVIATION...CLAYCOMB
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
858 AM PDT FRI MAY 25 2012
.SHORT TERM DISCUSSION...
.MID MORNING DISCUSSION UPDATE...
FORECAST PACKAGE REMAINS ON TRACK AND NO SIGNIFICANT CHANGES ARE
EXPECTED. PRIMARY ISSUES FOR THE DAY ARE THE TIMING AND LOCATION
OF THUNDERSTORM DEVELOPMENT AND THE INTENSITY OF SNOWFALL AND
ACTUAL SNOW LEVELS. ATMOSPHERIC MOISTURE LOOKS TO BE A BIT LESS
THAN INITIALLY THOUGHT SO SNOWFALL AMOUNTS MAY BE LESS THAN
CURRENTLY FORECAST THOUGH STRONG DYNAMIC FORCING MAY HELP SQUEEZE
OUT EXTRA PRECIPITATION.
.EARLY MORNING DISCUSSION...
THE NEGATIVE 3 TO 4 500 MBS ANOMALY CLOSED LOW WAS NEAR THE
CA/ORE BORDER AT 09Z...AND IS FORECAST TO DROP SWD OVER INTERIOR
NORCAL TODAY. THE NEUTRAL TO SLIGHTLY POSITIVE TILT OF THE TROF
AND THE FORECAST TRACK OF THE UPPER LOW EAST OF THE COASTAL RANGE
QUALIFIES IT AS AN "INSIDE SLIDER". LITTLE RETROGRESSION IS
FORECAST AS THE LOW DROPS INTO SOCAL...THEN ROTATES EWD ON SAT...
SALVAGING THE LATTER PART OF THE BIG HOLIDAY WEEKEND.
UPPER JET ENERGY DIGGING SWD ON THE BACKSIDE OF THE CLOSED LOW IS
DRIVING THE 2ND AND STRONGER VORT MAX ALONG THE COAST THIS MORNING
BEFORE IT ROTATES INLAND BY MID DAY. THE SHOWERS AND CUMULIFORM
CLOUDINESS OFF THE COAST SHOULD ALSO BE ROTATING INLAND WITH THIS
VORT MAX BY MID DAY. THE AMSU TPW DATA SHOW THE DIGGING UPPER JET
FORCING THE HIGHER PW AIR WWD OVER THE ERN PAC...THUS THIS VORT
MAX MAY BE LOSING A LOT OF ITS MOISTURE TAP...ALTHOUGH A "TONGUE"
OF HIGHER PW IS WRAPPED NEWD FROM BAJA/SOCAL INTO THE DESERT SW.
ALTHOUGH IT MAY TAKE AWHILE...THIS PW MAY BECOME ENTRAINED INTO
THE CLOSED LOW CIRCULATION AS IT DROPS SWD THIS AFTERNOON.
MEANWHILE...THE INITIAL VORT MAX IS TRIGGERING SOME SHOWERS THAT
BEGAN AROUND KBLU BUT NOW ARE MOSTLY IN WRN NV...AND WE LOOK FOR
ANOTHER SOURCE OF LIFT MOISTURE.
THE 2ND AREA OF LARGE SCALE ASCENT IS SEEN IN THE IR IMAGERY AS
COLDER CLOUD TOPS N/NE OF THE UPPER CIRCULATION. AS THE UPPER
CIRCULATION DROPS SWD...SO SHOULD THE BAND OF ENHANCED CLOUDS AND
SHOWERS. THE HRRR-3KM PRECIP FORECAST DROPS THIS PRECIP INTO THE
SHASTA CO AREA BY 18Z FRI. SINCE THE HRRR IS ONLY AN HOURLY 13 HR
FORECAST WE EXTRAPOLATE THAT AS THE UPPER LOW DROPS SWD TODAY...SO
WILL THE BAND OF SHOWERS THIS AFTERNOON AND EVENING.
ALTHOUGH THE STRONG VORT MAX WILL BE SOUTH OF OUR FORECAST AREA FRI
AFTERNOON...THE 5H COLD POOL AROUND -24 DEG C WILL BE OVER MUCH OF
THE AREA RESULTING IN STEEP LAPSE RATES ABOUT 8-10 DEG C/KM UP TO
500 MBS. THE EQUILIBRIUM LEVEL (EL) BARELY IS FORECAST TO REACH 20
KFT FRI AFTERNOON SO THESE WILL BE VERY LOW-TOPPED CELLS. THE HIGHER
SHEAR VALUES ARE FORECAST TO OCCUR AT NIGHT AND GENERALLY NOT DURING
THE TIME OF CONVECTION IN THE VALLEY...OTRW WE WOULD BE EXPECTING
THE POSSIBILITY OF ROTATING CELLS. HOWEVER...THERE SHOULD BE
NUMEROUS SHOWERS AND SCATTERED TSTORMS DEVELOPING...ESPECIALLY IN
THE NE QUAD OF THE UPPER LOW AND UNDER THE COLD POOL...FROM THE
COASTAL RANGE EWD INTO THE SIERNEV.
WE ARE STILL LOOKING AT SEVERAL TENTHS OF AN INCH OF QPF OVER THE
HIGHER TERRAIN...AND THAT COMBINED WITH LOWER THAN NORMAL SNOW
LEVELS DOWN TO 5 KFT OR SO...SOME ACCUMULATING SNOW IS EXPECTED OVER
THE HIGHER TERRAIN THROUGH FRI EVENING. 2-6 INCHES OF SNOW IS
FORECAST TO FALL DURING THE PERIOD ABOVE 6000 FT. THE WARM GROUND IS
EXPECTED TO MELT SOME SNOW ESPECIALLY AT THE LOWER SNOW LEVEL
ELEVATIONS. CYCLONIC FLOW IS FORECAST TO LINGER OVER THE SIERNEV
INTO SAT KEEPING THE CHANCE OF LIGHT SHOWERS GOING.
MAX TEMPS WILL BE SOME 15 DEG BELOW NORMAL TODAY...BUT WE HAVEN`T
GONE AS FAR AS FORECAST RECORD LOW MAX TEMPS AT OUR MAIN CLIMO
SITES. USUALLY...THE MAY SUN WILL SHINE LONG ENOUGH DUE TO BREAKS IN
THE CONVECTIVE CLOUDS TO KEEP THE RECORDS FROM BREAKING.
IN THE WAKE OF TH DEPARTING CLOSED LOW ON SUN...WEAK SHORT WAVES ARE
FORECAST TO MOVE THROUGH THE WLY FLOW AND ACROSS NORCAL SUN/MON.
THESE SYSTEMS MAY SPREAD SOME CLOUDINESS OVER NORCAL AT TIMES...BUT
ANY PRECIP IS EXPECTED TO REMAIN NORTH OF OUR AREA AT THIS TIME.
NEAR NORMAL TEMPS ARE EXPECTED TO RETURN BY SUN AND THE MEMORIAL
DAY HOLIDAY.
5H HEIGHTS ARE FORECAST TO REBUILD OVER THE WRN STATES FOR THE
MIDDLE OF NEXT WEEK WITH A RETURN TO ABOVE NORMAL TEMPS WITH MAXES
IN THE 90S IN THE VALLEY. AS THE RIDGE AXIS SHIFTS EWD INTO THE
INTERMOUNTAIN W...THE MID LEVEL FLOW MAY BACK OVER THE SIERNEV FOR
SOME AFTERNOON CONVECTION NEXT FRI. JHM
.EXTENDED DISCUSSION (TUESDAY THROUGH FRIDAY)
SHORT WAVE TROUGH MOVES THROUGH THE PAC NW MON INTO TUE WITH
SOUTHERN PORTIONS TRACKING THROUGH NORCAL. WITH MAIN DYNAMICS AND
MOISTURE REMAINING FARTHER NORTH...DRY WEATHER EXPECTED WITH LOWER
80S IN THE CENTRAL VALLEY MONDAY AND MID 80S TUESDAY. RIDGING
PROGGED TO BUILD OVER NORCAL WEDNESDAY INTO THURSDAY WITH WARMING
AMS. OPER GFS DEVELOPS UPPER LOW OFF THE CAL COAST WED AND LIFTS IT
NORTH ALONG THE COAST THU. ECMWF-HIRES AND GEM NOT SHOWING THIS
FEATURE AND DPROG/DT FOR THE GFS DURING THIS PERIOD SHOWING WEAK RUN
CONSISTENCY. THUS FORECAST REMAINS DRY WITH UPPER 80S TO LOWER 90S
FOR THE CENTRAL VALLEY THROUGH MIDWEEK WITH 70S TO 80S FOR THE
MOUNTAINS AND FOOTHILLS.
&&
.AVIATION...
MOUNTAIN AREAS IFR/OCCASIONAL MIFR WITH SHOWERS THIS
AFTERNOON AND EVENING. SNOW LEVEL NEAR 050 AGL AND NORTHWESTERLY
WIND GUSTS 25 KNOTS OVER RIDGES.
SACRAMENTO VALLEY THROUGH THIS AFTERNOON OCCASIONAL MVFR CONDITIONS.
OTHERWISE VFR CONDITIONS.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM PDT THIS EVENING ABOVE 6000
FEET FOR THE WEST SLOPE NORTHERN SIERRA NEVADA...WESTERN PLUMAS
COUNTY/LASSEN PARK.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
248 PM EDT FRI MAY 25 2012
.DISCUSSION...AN AREA OF LOW PRESSURE NORTH OF THE BAHAMAS WILL MOVE
NORTHEAST AND INTENSIFY THROUGH THIS EVENING, POSSIBLY
STRENGTHENING INTO A SUBTROPICAL OR TROPICAL ENTITY BY LATE
TONIGHT. A LARGE AMPLITUDE UPPER LEVEL TROUGH ALSO REMAINS ACROSS
THE SOUTHEAST U.S. AND EASTERN GULF WITH THE AXIS EXTENDING JUST
WEST OF SOUTH FLORIDA AND INTO THE VICINITY OF THE YUCATAN
PENINSULA. MEANWHILE, WEAK SURFACE HIGH PRESSURE IS ATTEMPTING TO
PUSH SOUTH OVER THE FLORIDA PENINSULA. WHILE THIS FEATURE HAS
AIDED IN LOWER PRECIPITABLE WATERS, SUFFICIENT AMOUNTS OF
MOISTURE WILL REMAIN IN PLACE ACROSS THE INTERIOR AND WEST
THROUGH THIS EVENING FOR AT LEAST ISOLATED TO SCATTERED
CONVECTION. ALONG MUCH OF THE EAST COAST, POPS HAVE BEEN REDUCED
TO 10-20 PERCENT FOR THIS AFTERNOON AND EARLY EVENING.
WITH A LACK OF APPRECIABLE FORCING ALOFT, ANY AFTERNOON/EVENING
CONVECTION WILL BE DRIVEN MAINLY BY SEA BREEZE INTERACTIONS AND
LOCAL MESO-SCALE EFFECTS. THE HRRR SHOWS THE WEST COAST SEA
BREEZE PUSHING INLAND AND PROVIDING ENOUGH LIFT TO RESULT IN
SCATTERED CONVECTION OVER WESTERN AND INTERIOR PORTIONS OF THE
REGION BY 21Z. A FEW STORMS COULD BECOME STRONG OR EVEN
MARGINALLY SEVERE, ESPECIALLY WITH ANY CELL MERGERS. STRONG WINDS
ARE THE PRIMARY CONCERN, ALTHOUGH SOME HAIL COULD ALSO OCCUR.
WITH THE EAST COAST SEA BREEZE CONTINUING TO ADVANCE INLAND,
LITTLE ACTIVITY IS EXPECTED ALONG THE IMMEDIATE EAST COAST. ANY
SHOWERS OR THUNDERSTORMS WILL GRADUALLY END AFTER 00Z, ALTHOUGH
SOME LINGERING ISOLATED ACTIVITY IS POSSIBLE OVERNIGHT, MAINLY
LIMITED TO THE GULF AND ATLANTIC WATERS.
FORECAST SOUNDINGS SHOW A SLIGHT INCREASE IN PRECIPITABLE WATERS
ON SATURDAY WHILE CONDITIONAL INSTABILITY COMBINED WITH SEA
BREEZE BOUNDARIES WILL RESULT IN ANOTHER ROUND OF ISOLATED TO
SCATTERED AFTERNOON CONVECTION. A FEW STORMS COULD AGAIN BE
STRONG, ALTHOUGH OVERALL COVERAGE SHOULD BE SIMILAR TO TODAY. THE
LATEST GUIDANCE REMAINS RATHER CONSISTENT AND SHOWS THE
DEVELOPING WARM-CORE LOW COMING TO A POSITION OFF THE SOUTH
CAROLINA COAST BY LATE SATURDAY. ITS FORWARD MOVEMENT WILL THEN
SLOW AND ULTIMATELY GO BACK TO THE WEST OR SOUTHWEST IN RESPONSE
TO BUILDING HIGH PRESSURE OFF THE MID ATLANTIC COAST. AS DEEP
LAYER MOISTURE INCREASES AND H85 WINDS BECOME SOUTHWESTERLY
ACROSS THE LOCAL AREA, CONVECTION MAY BECOME A BIT MORE
WIDESPREAD AND INTENSE ON SUNDAY AFTERNOON AND EVENING. A SIMILAR
PATTERN IS EXPECTED ON MONDAY.
WESTERLY FLOW ALOFT COUPLED WITH SIGNIFICANT MOISTURE WILL
PRODUCE AT LEAST SCATTERED SHOWERS AND STORMS TUESDAY INTO
WEDNESDAY. THE POSSIBLE WARM-CORE LOW PRESSURE SYSTEM WILL HAVE
WEAKENED, BUT WILL ONLY SLOWLY PUSH BACK TO THE EAST NORTHEAST
ACROSS THE FLORIDA PANHANDLE AND WESTERN ATLANTIC. SO WHILE THE
BEST SYNOPTIC FORCING WILL REMAIN TO THE NORTH, A RATHER
UNSETTLED PATTERN WILL LIKELY PREVAIL WITH PRECIPITATION CHANCES
GENERALLY AT OR ABOVE CLIMO.
&&
.AVIATION...18Z ISSUANCE...MAINLY VFR CONDITIONS WILL PREVAIL
THROUGHOUT THE FORECAST PERIOD. THE EAST COAST SEA BREEZE HAS
DEVELOPED AND CONTINUES TO MOVE INLAND. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS INTERIOR SECTIONS
AND THEN THEY COULD DRIFT BACK CLOSER TO THE EAST COAST TERMINALS
LATER THIS AFTERNOON. A WEST COAST SEA BREEZE WILL ALSO DEVELOP
AT KAPF AS THE AFTERNOON PROGRESSES. ANY SHOWERS OR THUNDERSTORMS
WILL DIMINISH LATER THIS EVENING AND WINDS WILL BECOME LIGHT AND
VARIABLE ACROSS ALL SOUTH FLORIDA TERMINALS.
&&
.MARINE...WINDS AND SEAS ARE FORECAST TO REMAIN BELOW ADVISORY LEVELS
THROUGH AT LEAST SATURDAY. HOWEVER, A SMALL SWELL MAY BEGIN TO
IMPACT THE LOCAL ATLANTIC WATERS, ESPECIALLY OFF THE PALM BEACH
COAST, BY SUNDAY. THERE IS SOME UNCERTAINTY IN THE FORECAST AS
THE ULTIMATE TRACK AND INTENSITY OF A POSSIBLE WARM CORE SYSTEM
TO THE NORTH WILL HAVE AT LEAST SOME IMPACT ON LOCAL MARINE
CONDITIONS.
&&
.FIRE WEATHER...NO SIGNIFICANT CONCERNS AS RELATIVE HUMIDITIES AND
OVERALL ATMOSPHERIC MOISTURE WILL REMAIN HIGH THROUGH THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 87 74 88 / 10 30 20 40
FORT LAUDERDALE 76 87 75 88 / 10 30 20 40
MIAMI 75 88 74 89 / 10 30 20 40
NAPLES 74 91 73 90 / 30 30 20 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...14/MJB
AVIATION/RADAR...55/CWC
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1243 PM CDT FRI MAY 25 2012
...UPDATED 18Z AVIATION DISCUSSION...
.SHORT TERM.../TODAY/
MAIN CONCERN TODAY WILL BE PRECIP TRENDS. ACTIVE JET CONTINUES TO
ROUND PACIFIC NW UPPER LOW AND EXTENDS INTO THE NRN PLAINS. WATER
VAPOR IMAGERY SHOWS JET SEGMENT AND SUBTLE ENHANCEMENT OF UVM
EJECTING FROM UT INTO NE/KS...WHICH HAS AIDED WEAK SRN NE ELEVATED
CONVECTION. PRECIP ALSO NICELY REFLECTED IN RAP 305K ISENT SFC WITH
MOISTURE CONVERGENCE AND LOWER RH FOCUSED INTO THIS AREA. WEAK
KINEMATIC FORCING WILL PERSIST AND LIFT NWD WITH JET AND BUILDING
RIDGE LATER TODAY AND WILL ALSO DRAW INCREASED THERMODYNAMIC FORCING
NWD ON LEADING EDGE OF MUCAPE/ELEVATED INSTABILITY GRADIENT.
PHASING OF UVM AND ADEQUATE MOISTURE SEEMS WEAK THIS MORNING...SO
NOTHING MORE THAN SLIGHT POPS SW IN CASE SOMETHING DRIBBLES INTO
FORECAST AREA. HOWEVER FORCING MECHANISMS BECOME BETTER ORGANIZED
BY AFTERNOON WITH 00Z ECMWF/GFS BOTH SHOWING SHARPLY INCREASED
H85/H7 THETA-E ADVECTION INTO IA BY 00Z. THIS WILL LIKELY DEVELOP
ADDITIONAL SCATTERED SHOWERS/THUNDERSTORMS...WHICH IS ALSO DEPICTED
BY VARIOUS WRF SOLUTIONS.
08Z SURFACE ANALYSIS SHOWS RIDGE FROM NE INTO THE HEART OF IA WHICH
WILL KEEP MIXING REDUCED TODAY. MOS GUIDANCE SEEMS TO HAVE DECENT
HANDLE ON THIS WITH HIGHS IN THE 70S OR LOWER 80S.
.LONG TERM.../TONIGHT THROUGH THURSDAY/
AS THE NEXT SHORTWAVE KICKS OUT OF THE WEST COAST TROUGH AND A
SOUTHERLY FLOW INCREASES OVER THE MIDWEST THE FRONT WHICH MOVED
THROUGH US YESTERDAY WILL LIFT NORTH OUT OF NORTHERN MISSOURI ACROSS
IOWA. 0-3KM SHEAR INCREASES THROUGH THE EVENING AS WELL AND LOOKING
AT SOUNDINGS THERE IS A 50-70KT JET OFF THE SURFACE AND IT IS
ACTUALLY TO A PRETTY GOOD DEPTH. STORMS THAT FIRE WILL EASILY HAVE
VERY ROBUST UPDRAFTS. EXPECTING MORE OF AN ELEVATED HAIL EVENT WITH
THE STORMS THIS EVENING AND LOCATION WILL DEPEND ON WHERE THE FRONT
WILL BE. CONVECTION MAY LINGER ACROSS CENTRAL IOWA INTO SATURDAY
MORNING THOUGH THAT FRONT WILL CONTINUE TO SHIFT EAST SO THE MAIN
AREA OF CONCERN FOR THUNDER WILL BE NORTHERN IOWA.
FOR THE REMAINDER OF SATURDAY AND SATURDAY NIGHT A STOUT CAP WILL BE
IN PLACE AND WE ARE LOOKING FOR LITTLE IN THE WAY OF CONVECTION IN
THE CWA...ASSUMING THE FRONT REMAINS IN SOUTHERN MN. SOUTHERLY
WINDS WILL BE ON THE INCREASE AGAIN ON SATURDAY POSSIBLY HAMPERED BY
CLOUD COVER AT LEAST INITIALLY. I DONT/ THINK WE WILL MIX AS GOOD
AS WE COULD.
FOR SUNDAY WE WILL SEE LESS CLOUD COVER AND A STRONGER SOUTH WIND
OVER THE AREA. I EXPECT THE CWA TO ONCE AGAIN BE CAPPED UNTIL A
COLD FRONT BEGINS TO PUSH INTO THE AREA LATE IN THE DAY AND
ESPECIALLY SUNDAY NIGHT. THERE WILL BE DEEP LAYER SHEAR WITH THIS
AND A STRONG JET AS A SHORT WAVE OVER THE PLAINS MOVES INTO WESTERN
IOWA. WE COULD SEE ALL MODES OF SEVERE WEATHER WITH THIS FRONT
THOUGH TIMING ISN/T THE BEST. DYNAMICALLY THOUGH I DONT THINK IT
WILL MATTER. WE WILL HAVE A LOT OF INSTABILITY WITH CAPES IN EXCESS
OF 1500 J/KG ADVECTING INTO THE AREA AND THE AFOREMENTIONED SHEAR.
SIMILAR TO THE OTHER NIGHT IT WILL LIKELY EVOLVE FROM SUPERCELLS
PRODUCING VERY LARGE HAIL AND SOME TORNADOES TO A LINEAR SYSTEM WITH
WIND DAMAGE PROBABLY OVER A FAIR PART OF THE CWA.
THE FRONT WILL HEAD EAST DURING THE DAY MONDAY ENDING THE THREAT FOR
STORMS BUT USHERING SOME PRETTY COOL AIR FOR EARLY NEXT WEEK.
BEYOND THAT THERE IS SUFFICIENT DISAGREEMENT ON A MID WEEK SHORTWAVE
THAT WILL BRING SHOWERS AND SOME THUNDER TO THE AREA BUT SHEAR IS
WEAK AND WE WILL BE MORE STABLE. KEPT THE POPS WE HAD GOING FOR
CONSISTENCY SAKE BUT TIMING AND LOCATION WILL NEED TO BE ADDRESSED
IN LATER FORECASTS.
&&
.AVIATION...25/18Z
EXPECT POTENTIALLY THREE ROUNDS OF CONVECTION DRIVEN BY DEEP WARM
ADVECTION BEFORE 12Z...AND THAT WILL BE MAIN DRIVER FOR AVIATION
WEATHER. CURRENT ACTIVITY ACROSS CENTRAL AND NORTH IOWA IS BASED
ABOVE 10000 FEET WITH ISOLATED THUNDER. THIS MAY DRIFT OFF TO THE
ENE BEFORE STRONGER DEVELOPED IS EXPECTED IN W AND SW IOWA WHICH
WILL MOVE EAST TO WEST 26/02Z-06Z WITH MVFR VISIBILITY. AS WARM
FRONT MOVES NORTH OVERNIGHT...LESS INTENSE SHOWER DEVELOPMENT COULD
CONTINUE WITH CEILINGS POSSIBLY APPROACHING MVFR OVER NORTH HALF OF
IOWA. EXPECT CLOUD BASES TO BE LIFTING AND BREAKING UP SATURDAY
MORNING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...BSS
LONG TERM...FAB
AVIATION...JUNGBLUTH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
315 PM MDT FRI MAY 25 2012
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY NIGHT)
ISSUED AT 315 PM MDT FRI MAY 25 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW LONGWAVE TROUGH
ACROSS THE WESTERN US...WITH A CLOSED CENTER OVER NORTHERN
CALIFORNIA. A LARGE SCALE RIDGE REMAINS IN PLACE OVER THE SOUTHERN
US...WITH WEST/SOUTHWEST FLOW OVER THE CENTRAL HIGH PLAINS BETWEEN
THESE FEATURES. AT THE SURFACE A WARM FRONT HAS LIFTED NORTH TO LIE
ALONG THE KS/OK STATE LINE.
THIS WARM FRONT IS EXPECTED TO CONTINUE TO LIFT NORTH THROUGH
TONIGHT...WITH SHOWERS AND THUNDERSTORMS POSSIBLE OVER EASTERN PARTS
OF OUR FORECAST AREA WHERE THE CAP IS FORECAST TO WEAKEN AROUND 00Z.
SHEAR PROFILES ALONG THE WARM FRONT WOULD BE SUPPORTIVE OF SUPERCELL
GROWTH...WITH STRONG WINDS/HAIL THE MAIN THREAT OVER OUR AREA.
CLEARING HAS OCCURRED AHEAD OF THE WARM FRONT WITH STRATUS BEGINNING
TO BREAK UP OVER THE CWA. AS THE FRONT LIFTS NORTH BL MOISTURE WILL
INCREASE NORTH OF THE FRONT...WITH TD VALUES IN THE MID 50S ACROSS
MUCH OF THE CWA. THIS SHOULD SUPPORT FOG/STRATUS DEVELOPMENT JUST
NORTH OF THE FRONT. GUIDANCE HAS COME INTO BETTER AGREEMENT ON THE
TIMING OF THIS FRONT...WITH OVERALL TREND INITIALLY QUICKER THAN
PREVIOUSLY EXPECTED BRINGING A MUCH DRIER AIRMASS INTO THE CWA AFTER
06Z...SO THERE WILL PROBABLY BE ONLY A BRIEF WINDOW FOR FOG/STRATUS
ACROSS MUCH OF THE CWA...THOUGH LOCATIONS IN THE NORTH COULD SEE FOG
LINGER THROUGH SUNRISE SATURDAY.
SATURDAY AND SATURDAY NIGHT...BUSY PERIOD WEATHER-WISE WITH
MULTIPLE CONCERNS. SURFACE LEE CYCLOGENESIS WILL TAKE PLACE ACROSS
SOUTHEASTERN WYOMING ON SATURDAY RESULTING IN A TIGHTENING
PRESSURE GRADIENT. ADDITIONALLY...THE ATMOSPHERE WILL BECOME
DEEPLY MIXED. WITH MODERATE FLOW ALOFT...STRONG WIND GUSTS WILL
DEVELOP BY EARLY AFTERNOON. LATEST GUIDANCE WOULD SUPPORT AT LEAST
HIGH END ADVISORY LEVEL CRITERIA BUT CONFIDENCE WAS NOT GREAT
ENOUGH IN HIGH WIND WARNING CRITERIA BEING MET SO OPTED TO
MAINTAIN THE GOING HIGH WIND WATCH.
ADDITIONAL CONCERNS FOR SATURDAY REVOLVE AROUND POTENTIAL FOR
NEAR-RECORD/RECORD TEMPS AND BORDERLINE CRITICAL FIRE WEATHER
CONDITIONS. CURRENT RECORDS ARE LISTED BELOW IN THE CLIMATE
SUBSECTION OF THIS DISCUSSION BUT SATURDAY WILL BE THE HOTTEST DAY
OF THE YEAR SO FAR WITH MANY LOCATIONS EXPECTED TO REACH THE UPPER
90S TO NEAR 100 DEGREES. AT THE SAME TIME...RELATIVE HUMIDITY
VALUES WILL FALL TO LESS THAN 20 PERCENT FOR MUCH OF THE AREA WITH
EASTERN COLORADO EXPECTED TO APPROACH 10 PERCENT. HOWEVER...FUELS
HAVE GREENED QUITE A BIT WITH THE RECENT PRECIPITATION SO NO FIRE
WEATHER HIGHLIGHT PLANNED THOUGH ALL OUTDOOR BURNING IS STRONGLY
DISCOURAGED GIVEN THE ANTICIPATED WINDS.
FINALLY...ISOLATED CONVECTION CAN`T BE RULED OUT ACROSS THE
NORTHEASTERN PORTION OF THE FORECAST AREA LATE SATURDAY EVENING
INTO THE OVERNIGHT HOURS AS BROAD-SCALE FORCING FOR ASCENT
INCREASES ACROSS THE REGION.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 315 PM MDT FRI MAY 25 2012
SUNDAY AND SUNDAY NIGHT...STILL LOOKS ON TRACK TO BE POTENTIALLY
VERY ACTIVE ACROSS EASTERN PORTIONS OF THE FORECAST AREA FROM A
SEVERE WEATHER STANDPOINT. POTENT SHORTWAVE TROUGH WILL BEGIN TO
IMPACT THE REGION LATE SUNDAY MORNING WITH A DRYLINE SETTING UP
ACROSS THE MIDDLE OF THE FORECAST AREA. EAST OF THE
DRYLINE...STEEP LOW/MID- LEVEL LAPSE RATES...MLCAPE OF 1500-2500
J/KG AND DEEP LAYER SHEAR OF 50-60 KTS WILL AID IN UPDRAFT
FORMATION AND ORGANIZATION. LOW LEVEL PARAMETERS APPEAR SUPPORTIVE
OF AT LEAST ISOLATED TORNADOES AFTER 21Z AS THE CAP ERODES
RAPIDLY. FOCUS SHIFTS EASTWARD AWAY FROM THE FORECAST AREA BY 03Z.
MONDAY THROUGH TUESDAY...QUASI-ZONAL FLOW SETS UP WITH DRY
CONDITIONS EXPECTED THROUGH AT LEAST MID-DAY TUESDAY WHEN A WEAK
SHORTWAVE TROUGH WILL MOVE ACROSS THE FORECAST AREA. FOCUS FOR
ASCENT IS POSITIONED EAST OF THE KS/CO BORDER WHERE SLIGHT
CHANCE/CHANCE POPS WILL CONTINUE.
WEDNESDAY AND WEDNESDAY NIGHT...MID/UPPER RIDGE BEGINS TO BUILD
OVER THE WESTERN CONUS RESULTING IN A MORE NORTHWESTERLY FLOW
ALOFT ACROSS THE CENTRAL HIGH PLAINS. A SHORTWAVE TROUGH/SURFACE
COLD FRONT IS PROGGED TO TRANSLATE SOUTHEAST FROM THE NORTHERN
ROCKIES. THE OPERATIONAL GFS IS CERTAINLY MORE ROBUST WITH THIS
FEATURE AS COMPARED TO THE EC BUT FEEL COMFORTABLE CARRYING SLIGHT
CHANCE/CHANCE POPS ACROSS MUCH OF THE FORECAST AREA.
THURSDAY THROUGH FRIDAY...BEHIND WEDNESDAY`S COLD FRONT...WILL SEE
TEMPS ON THURSDAY ABOUT 10 DEGREES COLDER. TEMPS REBOUND BACK TO
NEAR NORMAL ON FRIDAY WITH DRY CONDITIONS EXPECTED AS THE WESTERN
CONUS MID/UPPER RIDGE BEGINS TO TRANSLATE EASTWARD TOWARD THE
REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1133 AM MDT FRI MAY 25 2012
MVFR CIGS WILL DEVELOP AT BOTH TERMINALS THIS AFTERNOON AND
EVENING AS A WARM FRONT LIFTS NORTH OUT OF SOUTHWEST KANSAS.
BL MOISTURE WILL REMAIN HIGH NORTH OF THIS FRONT WITH EASTERLY
UPSLOPE FORECAST THROUGH THE NIGHT. POSITION OF THE FRONT...AND
TIMING OVERNIGHT IS A BIG QUESTION MARK STILL WITH A LARGE SPREAD
IN GUIDANCE WHICH WILL EFFECT HOW LONG FOG/STRATUS WILL OCCUR AT
EACH TERMINAL. BASED ON LATEST SHORT RANGE GUIDANCE IFR CONDITIONS
SHOULD DEVELOP BY 03Z AT BOTH TERMINALS...WITH LIFR CONDITIONS
POSSIBLE AT KMCK THROUGH 12Z. I WAS NOT CONFIDENT ENOUGH TO
DECREASE CONDITIONS BELOW IFR IN THE TAFS. CONDITIONS SHOULD
QUICKLY IMPROVE BEHIND THE WARM FRONT AS IT LIFTS NORTH...WHICH
SHOULD BE AROUND 09Z AT KGLD AND AROUND 12-13Z AT KMCK. CHANCES
WERE TOO LOW TO INCLUDE THUNDERSTORM MENTION AT KMCK THIS
AFTERNOON AND EVENING...THOUGH A FEW STORMS COULD DEVELOP AROUND
THE AREA.
&&
.CLIMATE...
ISSUED AT 245 AM MDT THU MAY 24 2012
RECORD AND NEAR RECORD HIGH TEMPERATURES EXPECTED SATURDAY.
GOODLAND.....97 IN 2006
HILL CITY....99 IN 1912
MCCOOK.......98 IN 1967
BURLINGTON...95 IN 1942
YUMA.........96
TRIBUNE......101
COLBY........98
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING
FOR KSZ001-013-027-041.
CO...HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING
FOR COZ090>092.
NE...HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING
FOR NEZ079.
&&
$$
SHORT TERM...DR/FOLTZ
LONG TERM...FOLTZ
AVIATION...DR
CLIMATE...007
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
257 PM CDT FRI MAY 25 2012
...UPDATED SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1215 PM CDT FRI MAY 25 2012
A -27C 500MB UPPER LOW WAS LOCATED OVER NORTHERN CALIFORNIA WITH
A SOUTHWEST FLOW PRESENT FROM THE SOUTHWESTERN UNITED STATES
ACROSS THE CENTRAL AND NORTHERN PLAINS. A SUBTLE UPPER LEVEL
DISTURBANCE WERE EMBEDDED IN THIS SOUTHWEST FLOW WITH ONE SUBTLE
WAVE APPEARING ACROSS THE TEXAS PANHANDLE, VIA WATER VAPOR LOOP.
AT 250 AND 300MB LEVEL AN UPPER LEVEL JET STREAK WAS LOCATED
ACROSS THE NORTHERN PLAINS WITH THE LEFT ENTRANCE REGION OF THIS
JET NEAR CENTRAL/EASTERN NEBRASKA. AT 700MB THE NORTHERN EDGE OF
ELEVATED MIXED LAYER APPEARS TO EXTEND FROM WEST TO EAST ACROSS
NORTHERN KANSAS WITH +12C AT DOGE CITY, +14C AT AMARILLO, AND +13C
AT OKLAHOMA CITY. AT 850MB LEVEL MOISTURE WAS POOLING NEAR THE
NORTHERN EDGE OF THE 850MB WARM FRONT WHICH STRETCHED FROM THE
PANHANDLE OF OKLAHOMA INTO SOUTH CENTRAL KANSAS. THE WARM FRONT
WHICH WAS LOCATED NEAR THE OKLAHOMA BORDER AT 12Z FRIDAY WAS AT
17Z LOCATED FROM NEAR GARDEN CITY EASTWARD INTO CENTRAL KANSAS. A
DRYLINE APPEARS TO BE DEVELOPING JUST WEST OF DODGE CITY SOUTH OF
THIS WARM FRONT.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 246 PM CDT FRI MAY 25 2012
DODGE CITY RADAR APPEARS TO BE PICKING UP ON THE WARM FRONT AS OF
18Z AND PLACED THIS BOUNDARY FROM NEAR GARDEN CITY TO JETMORE TO
NEAR BURDETT AND LARNED. RAP ALSO INDICATING IMPROVING 925-850MB
FRONTOGENESIS ALONG THIS BOUNDARY WHILE 700MB TEMPERATURES VARIED
FROM +13 TO +14C. SPC MESOSCALE ANALYSIS PAGE STILL INDICATING A
CAP IN PLACE BUT ALSO HAD 2000-3000J/KG PRESENT IN THIS AREA AS
WELL. CLOUD COVER FINALLY STARTING TO ERODE AND TEMPERATURES ARE
STARTING TO CLIMB INTO THE MID TO UPPER 80S. AT THIS TIME IT STILL
APPEARS THAT THE CONVECTIVE TEMPERATURE WILL BE REACHED BY LATE
DAY...ESPECIALLY EAST OF JETMORE. WILL THEREFORE RAISE
PRECIPITATION CHANCES NEAR THIS BOUNDARY AND EAST OF JETMORE LATE
TODAY. LATEST RAP CONTINUES TO INDICATED 0-6KM SHEAR OF 50KTS, LOW
LEVEL SHEAR NEAR/NORTH OF THE WARM FRONT AND LOW LCLS AT 00Z
SATURDAY SO IF STORMS CAN OVERCOME THE CAP LARGE HAIL AND POSSIBLY
A TORNADO OR TWO STILL SEEMS REASONABLE NEAR THE WARM FRONT. CORFIDI
VECTORS AND BUNKERS STORM MOTION INDICATES A NORTHEAST MOVEMENT
FROM THESE STORMS LATE TODAY WHICH SHOULD TAKE ANY LATE DAY
CONVECTION ALONG THIS BOUNDARY EAST OF HIGHWAY 281 BY OR SHORTLY
AFTER SUNSET.
A DRYLINE THIS AFTERNOON WILL EXTEND SOUTH OF THIS WARM FRONT
INTO THE PANHANDLE OF OKLAHOMA. BASED ON 18Z SURFACE ANALYSIS THIS
DRYLINE LOCATED NEAR DODGE CITY AND ASHLAND. THIS WILL ALSO BE AN
AREA OF FORCING LATE TODAY BUT AT THIS TIME IT APPEARS THAT GIVEN
THE HIGHER LCLS AND WEAKER LOW LEVEL SHEAR THE PRIMARY HAZARD FROM
THESE STORMS IF THEY DEVELOP WILL BE HAIL. AGAIN STORM MOTION WILL
TAKE THESE STORMS NORTHEAST AT 30 TO 40 KNOTS.
AFTER MIDNIGHT THE WARM FRONT IS STILL FORECAST BY ALL THE MODELS
TO LIFT NORTH OF INTERSTATE 70 AS THE DRY LINE RETREATS WESTWARD
TOWARDS THE COLORADO BORDER. AN AREA OF LOW PRESSURE WILL BEGIN TO
DEVELOP ALONG THE LEE OF THE ROCKIES ON SATURDAY AS THE NORTHERN
CALIFORNIA UPPER LOW STARTS TO MOVE EAST ACROSS THE WESTERN UNITED
STATES. FALLING PRESSURES ALONG THE LEE TROUGH WILL RESULT IN A
TIGHT SURFACE PRESSURE GRADIENT ACROSS WESTERN KANSAS DURING THE
DAY. THIS ALONG WITH MEAN MIXED LAYER WINDS OF OF 35 TO NEAR 40
KTS AM LEANING TOWARDS ISSUING A WIND ADVISORY FOR PORTIONS OF OF
WESTERN KANSAS. PREVIOUS FORECAST WITH SUSTAINED WINDS OF 27 TO
NEAR 30 KNOTS STILL APPEARS ON TRACK. THERE WILL ALSO BE A SLIGHT
CHANCE FOR THUNDERSTORMS ONCE AGAIN NEAR A SURFACE BOUNDARY WHICH
AT THIS TIME APPEARS TO EXTEND FROM NEAR HAYS TO ELKHART LATE DAY.
THIS IS SLIGHTLY FURTHER WEST THAN WHAT PREVIOUS MODELS HAD PLACED
THIS BOUNDARY LATE DAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 222 PM CDT FRI MAY 25 2012
SATURDAY NIGHT:
THE 12Z NAM SHOWS A WEAK UL SPEED MAX MOVING ACROSS WESTERN KANSAS SATURDAY
NIGHT. THIS MIGHT BE ENOUGH TO TRIGGER ISOLATED CONVECTION ACROSS THE
CENTRAL OR WESTERN ZONES TOMORROW EVENING. NOT VERY CONFIDENT ON THE
OVERALL COVERAGE GIVEN THIS SMALL PERTURBATION THAT MIGHT NOT PAN OUT
AND FAIRLY WARM 11 TO 12 DEG C 700 HPA TEMPERATURES. AS A RESULT, WE
KEEP POPS IN THE SLIGHT CHANCE CATEGORY. KINEMATIC AND THERMODYNAMIC
PROFILES ARE NOT THAT IMPRESSIVE FOR SEVERE (1000 J/KG SBCAPE/20
KT 0-6 KM SHEAR).
SUNDAY:
THE FORECAST BECOMES MUCH MORE INTERESTING SUNDAY AFTERNOON AND EVENING.
A 95 KT 250 HPA JET WILL MOVE ACROSS NORTHEAST COLORADO AND INTO WESTERN
NEBRASKA WHICH WILL PUT THE AREA IN A MORE FAVORABLE DIFFLUENT PATTERN
ALOFT TO SUPPORT CONVECTION. THE HIGHEST POPS ARE EXPECTED ALONG THE
TRIPLE POINT OF THE SURFACE LOW PRESSURE CENTER, THE DRYLINE AND THE
WARM FRONT. SEVERE WEATHER WILL DEFINITELY BE MORE OF A CONCERN AS THE
OVERALL KINEMATIC PROFILE STRENGTHENS AND IN COMBINATION WITH DECENT
SURFACE BASED CAPE. ANVIL LEVEL SR FLOW AROUND 35 KT, 3 TO 6 KM SR FLOW
OF 18 KT, 700-850 HPA LAPSE RATES OF 8.2 C/KM, AND 500-300 HPA LAPSE
RATES OF 7.2 C/KM ALL POINT TO THE CHANCE FOR GIANT HAIL SUNDAY. MUCAPE/MLCAPE
DURING THE AFTERNOON IS FORECAST TO ABOUT AROUND 2000 J/KG. THE EVENT
LOOKS SYNOPTICALLY SIMILAR TO JUNE 18TH 2010 WHERE GRAPEFRUIT SIZE HAIL
WAS REPORTED. OF COURSE, THIS IS ALL MESOSCALE NOISE AT THIS POINT AND
SUBJECT TO CHANGE. FOR TORNADO POTENTIAL, WOULD NOT RULE OUT A TORNADO
BUT THE LOWER LCLS ARE FORECAST ACROSS NC KS/SC NE ALONG THE WARM FRONT.
MONDAY:
250/500 HPA FLOW BECOMES MORE WESTERLY IN THE WAKE OF THE DEPARTING
SYNOPTIC WAVE MONDAY. WILL CONTINUE WITH A DRY FORECAST AND SLIGHTLY
ABOVE NORMAL HIGHS. HAVE GONE WITH THE WARMER ECMWF SOLUTION GIVEN
850 HPA TEMPERATURES STILL FORECAST IN THE 20S DEG C. A MUCH DRIER
AIRMASS WILL ADVECT IN ACROSS THE REGION WITH DEWPOINTS TANKING
DOWN INTO THE 30S & 40S DEG F.
TUESDAY AND BEYOND:
DID NOT STRAY FROM THE ALLBLEND POPS FOR TUESDAY AND WEDNESDAY. A WEAK
SUBTROPIC JET WILL MOVE ACROSS THE SOUTHWEST WITH LEE TROUGHING, MOISTURE
RETURN, AND THE POSSIBILITY OF THUNDERSTORMS MIDWEEK. THE ECMWF IS MORE
CONSERVATIVE WITH QPF THAN COMPARED TO THE GFS SO CONFIDENCE IS LOW.
TEMPERATURES MAY FINALLY COOL DOWN TO NEAR NORMAL VALUES TOWARDS THE
END OF THE MONTH AS NORTHWESTERLY FLOW ALOFT DEVELOPS AND 700/850 HPA
TEMPERATURES COOL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1215 PM CDT FRI MAY 25 2012
LOW MVFR CIGS LINGERING NORTH OF A WARM FRONT WHICH AT 17Z
EXTENDED FROM NEAR GARDEN CITY TO HUTCHINSON. BUFR SOUNDINGS AT
HAYS INDICATING THESE MVFR CIGS WILL IMPROVE TO VFR CIGS BY 20Z
WITH CLEARING SKIES LIKELY AFTER 00Z SATURDAY AS EASTERLY WINDS AT
10 TO 15 KNOTS BECOME SOUTHEAST. LATE DAY THUNDERSTORMS WILL BE
POSSIBLE NEAR THE WARM FRONT LATE TODAY AND A DRYLINE WHICH WILL
EXTEND SOUTH FROM THIS WARM FRONT INTO THE PANHANDLE OF OKLAHOMA.
AT THIS TIME BASED ON THE SCATTERED NATURE OF THE STORMS LATE
TODAY AND WARM LAYER EXPECTED ACROSS FAR SOUTHWEST KANSAS WILL
INCLUDE VCTS ONLY IN THE HAYS TAF LATE TODAY. THE WARM FRONT IS
EXPECTED TO CONTINUE TO LIFT NORTH INTO NORTH CENTRAL KANSAS
OVERNIGHT WHICH WILL ALLOW SOUTH/SOUTHEAST WINDS TO CONTINUE AT
ALL TAF SITES OVERNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 96 70 92 / 20 20 20 40
GCK 64 97 69 93 / 10 20 20 30
EHA 61 96 66 90 / 10 20 20 10
LBL 65 96 69 91 / 10 20 20 20
HYS 67 97 72 91 / 30 20 20 60
P28 72 94 72 91 / 20 10 10 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON CDT /11 AM MDT/ TO 8 PM CDT /7 PM MDT/
SATURDAY FOR KSZ043-044-061>063-074>077-084>087.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
116 PM MDT FRI MAY 25 2012
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 114 PM MDT FRI MAY 25 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW LONGWAVE TROUGH
ACROSS THE WESTERN US...WITH A CLOSED CENTER OVER NORTHERN
CALIFORNIA. A LARGE SCALE RIDGE REMAINS IN PLACE OVER THE SOUTHERN
US...WITH WEST/SOUTHWEST FLOW OVER THE CENTRAL HIGH PLAINS BETWEEN
THESE FEATURES. AT THE SURFACE A WARM FRONT HAS LIFTED NORTH TO LIE
ALONG THE KS/OK STATE LINE.
THIS WARM FRONT IS EXPECTED TO CONTINUE TO LIFT NORTH THROUGH
TONIGHT...WITH SHOWERS AND THUNDERSTORMS POSSIBLE OVER EASTERN PARTS
OF OUR FORECAST AREA WHERE THE CAP IS FORECAST TO WEAKEN AROUND 00Z.
SHEAR PROFILES ALONG THE WARM FRONT WOULD BE SUPPORTIVE OF SUPERCELL
GROWTH...WITH STRONG WINDS/HAIL THE MAIN THREAT OVER OUR AREA.
CLEARING HAS OCCURRED AHEAD OF THE WARM FRONT WITH STRATUS BEGINNING
TO BREAK UP OVER THE CWA. AS THE FRONT LIFTS NORTH BL MOISTURE WILL
INCREASE NORTH OF THE FRONT...WITH TD VALUES IN THE MID 50S ACROSS
MUCH OF THE CWA. THIS SHOULD SUPPORT FOG/STRATUS DEVELOPMENT JUST
NORTH OF THE FRONT. GUIDANCE HAS COME INTO BETTER AGREEMENT ON THE
TIMING OF THIS FRONT...WITH OVERALL TREND INITIALLY QUICKER THAN
PREVIOUSLY EXPECTED BRINGING A MUCH DRIER AIRMASS INTO THE CWA AFTER
06Z...SO THERE WILL PROBABLY BE ONLY A BRIEF WINDOW FOR FOG/STRATUS
ACROSS MUCH OF THE CWA...THOUGH LOCATIONS IN THE NORTH COULD SEE FOG
LINGER THROUGH SUNRISE SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI MAY 25 2012
SATURDAY NIGHT-SUNDAY NIGHT...ANY THUNDERSTORMS SATURDAY AFTERNOON
WILL LIFT OUT OF THE AREA EARLY SATURDAY NIGHT. COLD FRONT STARTS
TO ENTER THE AREA REACHING THE FAR EASTERN PARTS OF THE AREA
SUNDAY WHERE SEVERE THUNDERSTORMS AGAIN POSSIBLE. HIGH
TEMPERATURES WILL BE COOLER WITH 80S ACROSS MUCH OF THE AREA...LOW
90S FROM NORTON TO HILL CITY INTO TRIBUNE.
MONDAY...DRY WITH LOW TO MID 80S.
TUESDAY...UPPER DISTURBANCE MOVES INTO THE AREA BRINGING A CHANCE
OF THUNDERSTORMS TO THE AREA THROUGH TUESDAY NIGHT. HIGHS IN THE 80S.
WEDNESDAY...POTENTIALLY STRONG DISTURBANCE EMBEDDED IN NORTHWEST
FLOW ALOFT TO MOVE INTO THE AREA BRINGING ANOTHER CHANCE OF
THUNDERSTORMS. HIGHS AGAIN IN THE 80S.
THURSDAY...SHOULD BE DRY BEHIND WEDNESDAYS SYSTEM. HIGHS IN THE
LOW 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1133 AM MDT FRI MAY 25 2012
MVFR CIGS WILL DEVELOP AT BOTH TERMINALS THIS AFTERNOON AND
EVENING AS A WARM FRONT LIFTS NORTH OUT OF SOUTHWEST KANSAS.
BL MOISTURE WILL REMAIN HIGH NORTH OF THIS FRONT WITH EASTERLY
UPSLOPE FORECAST THROUGH THE NIGHT. POSITION OF THE FRONT...AND
TIMING OVERNIGHT IS A BIG QUESTION MARK STILL WITH A LARGE SPREAD
IN GUIDANCE WHICH WILL EFFECT HOW LONG FOG/STRATUS WILL OCCUR AT
EACH TERMINAL. BASED ON LATEST SHORT RANGE GUIDANCE IFR CONDITIONS
SHOULD DEVELOP BY 03Z AT BOTH TERMINALS...WITH LIFR CONDITIONS
POSSIBLE AT KMCK THROUGH 12Z. I WAS NOT CONFIDENT ENOUGH TO
DECREASE CONDITIONS BELOW IFR IN THE TAFS. CONDITIONS SHOULD
QUICKLY IMPROVE BEHIND THE WARM FRONT AS IT LIFTS NORTH...WHICH
SHOULD BE AROUND 09Z AT KGLD AND AROUND 12-13Z AT KMCK. CHANCES
WERE TOO LOW TO INCLUDE THUNDERSTORM MENTION AT KMCK THIS
AFTERNOON AND EVENING...THOUGH A FEW STORMS COULD DEVELOP AROUND
THE AREA.
&&
.CLIMATE...
ISSUED AT 245 AM MDT THU MAY 24 2012
RECORD AND NEAR RECORD HIGH TEMPERATURES EXPECTED SATURDAY.
GOODLAND.....97 IN 2006
HILL CITY....99 IN 1912
MCCOOK.......98 IN 1967
BURLINGTON...95 IN 1942
YUMA.........96
TRIBUNE......101
COLBY........98
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING
FOR KSZ001-013-027-041.
CO...HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING
FOR COZ090>092.
NE...HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING
FOR NEZ079.
&&
$$
SHORT TERM...DR
LONG TERM...007
AVIATION...DR
CLIMATE...007
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1253 PM CDT FRI MAY 25 2012
.UPDATE...
ISSUED AT 1253 PM CDT FRI MAY 25 2012
DID A QUICK UPDATE TO SPREAD THE SLIGHT CHANCE POPS DOWN INTO
SOUTHEAST MISSOURI...MAINLY FOR THE POTENTIAL OF A FEW ISOLATED
STORMS MOVING EAST OUT OF THE OZARKS. LATEST SATELLITE IMAGERY
INDICATES TCU DEVELOPMENT IN THAT AREA...AND THE HRRR MODEL
DEVELOPS SOME CONVECTION THERE AS WELL. WILL STILL HAVE TO MONITOR
THE INTERSTATE 64 CORRIDOR FOR DEVELOPMENT...BUT THE BETTER CHANCE
AT THIS POINT SEEMS TO BE IN SOUTHEAST MISSOURI.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 230 AM CDT FRI MAY 25 2012
FORECAST GENERALLY IN GOOD SHAPE THROUGH THE WEEKEND...WITH MAX
TEMPS BEGINNING BECOME A SIGNIFICANT FACTOR, WILL LIKELY SEE NEAR
RECORD HEAT BY SAT IN THE MID 90S...AND RECORD HEAT IN THE MID TO
UPPER 90S SUNDAY.
WILL LIKELY GO A TAD ABOVE MOS MAX TEMPS BY THAT TIME GIVEN THE
SOIL DROUGHT CONDITIONS. ONE POSITIVE RESULT OF THE DRY GROUND IS
LESS EVAPOTRANSPERATION...WHICH HOPEFULLY HELP KEEP SFC DEW POINTS
IN CHECK MID 60S. THIS SHOULD ACT TO KEEP AFTERNOON HEAT INDEX
VALUES VERY CLOSE TO ACTUAL TEMPS. THEREFORE...NO HEADLINES WILL
BE ISSUED FOR HEAT AS OF NOW. WILL REISSUE SPECIAL WEATHER
STATEMENT FOR THE HEAT AND DRY FUELS MOISTURE CONDITIONS...WHICH
WILL ELEVATE WILDFIRE RISKS OVER THE WEEKEND. LACK OF STRONG WINDS
AND HUMIDITIES HOLDING IN THE 40S WILL WILL HELP EASE THIS FACTOR
A BIT.
FLY IN THE OINTMENT CONTINUES FOR TODAY AS SFC TROF IS NOW
ADVERTISED BY MOST MODELS TO EASE DOWN TOWARD I 64 REGION THIS
AFTERNOON. WITH STRONG INSTABILITY EXPECTED TO DEVELOP WITH
SUNSHINE LATE MORNING...AND OVERALL MOISTURE VERY MARGINAL...
DECIDED TO INCREASE POPS INTO LOW CHC CATEGORY NORTH OF I 64...ESP
THIS AFTERNOON WHEN LI VALUES ARE ADVERTISED FROM -6 TO -9.
AGAIN...WOULD NOT CHANGE ANY HOLIDAY PLANS BASED ON THIS...BUT
GIVEN POSSIBLE TRAVEL/SOCIAL IMPACTS...WOULD RATHER HAVE A SMALL
RISK AND HAVE NOTHING OCCUR THAN THE OPPOSITE. HIGH ALOFT MOVES
QUICKLY NORTH INTO THE OHIO VALLEY THOUGH BY FRIDAY NIGHT
SAT...ENDING MOST PRECIP CHCS AS THERMAL CAP FORMS ALOFT. THE
WEEKEND WILL LIKELY BE THE HOTTEST AFTERNOONS OF THE FORECAST
PERIOD.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 230 AM CDT FRI MAY 25 2012
EVEN THOUGH THE UPPER LEVEL RIDGE WILL BEGIN TO LOSE ITS GRIP ON THE
REGION EARLY NEXT WEEK...THE NEAR RECORD HEAT SHOULD PERSIST THROUGH
MEMORIAL DAY. TEMPERATURES WILL LIKELY BE AT LEAST A COUPLE DEGREES
ABOVE MOS GUIDANCE ON MEMORIAL DAY...AS HIGHS AGAIN REACH THE MID
90S IN MOST LOCATIONS. MAINTAINED FORECAST DEW POINTS BELOW THOSE OF
MOS FOR MONDAY AS WELL...WHICH SHOULD KEEP HEAT INDEX READINGS IN
CLOSE PROXIMITY TO ACTUAL AIR TEMPERATURES.
THE GFS AND ECMWF ALSO CONTINUE TO DIFFER ON PRECIP CHANCES FOR
MONDAY...WITH THE ECMWF CONSISTENTLY DRY AND THE GFS CONTINUING TO
HINT AT THE POTENTIAL FOR ISOLATED THUNDERSTORMS MONDAY AFTERNOON.
IF THE GFS IS TOO HIGH WITH DEW POINTS AS WE BELIEVE...IT WOULD ALSO
BE OVERLY UNSTABLE...AND THUS OVERDONE WITH PRECIP CHANCES. AS A
RESULT...WILL STICK WITH THE DRY ECMWF FOR NOW GIVEN OUR PREFERENCE
TOWARDS ITS LOWER DEW POINT FORECAST.
BY MONDAY NIGHT AND TUESDAY...THE UPPER LEVEL RIDGE WILL CONTINUE TO
BE SUPPRESSED TO THE SOUTH BY AN APPROACHING UPPER LEVEL TROUGH OVER
THE CENTRAL UNITED STATES. A COLD FRONT WILL ACCOMPANY THIS TROUGH
AS IT DROPS SOUTH INTO THE REGION ON TUESDAY. MOISTURE CONVERGENCE
ALONG THE FRONT WILL AID IN THE DEVELOPMENT OF SCATTERED SHOWERS AND
THUNDERSTORMS MONDAY NIGHT AND TUESDAY. DRY CONDITIONS SHOULD RETURN
TUESDAY NIGHT AS THE FRONT SHIFTS JUST SOUTH OF THE AREA.
FORECAST CONFIDENCE REMAINS LOW WEDNESDAY AND THURSDAY. THE ECMWF
HINTS AT THE POTENTIAL FOR REMNANT CONVECTIVE ACTIVITY MAINLY OVER
WESTERN PORTIONS OF THE AREA ON WEDNESDAY...WHILE THE GFS IS DRY.
BOTH MODELS INDICATE THE APPROACH OF A MUCH STRONGER SYSTEM BY
THURSDAY...BUT DIFFER ON THE TIMING AND STRENGTH OF THE SYSTEM. FOR
NOW...WILL KEEP WEDNESDAY NIGHT DRY ACROSS MOST OF THE AREA...WITH
CHANCE POPS ON THURSDAY. ONE THING DOES LOOK CERTAIN THOUGH...AND
THAT IS A TREND TOWARDS MILDER WEATHER AS WE HEAD INTO THE LATTER
HALF OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1218 PM CDT FRI MAY 25 2012
TAFS REFLECT TYPICAL DIURNAL TRENDS IN CU AND SOUTH SOUTHWEST
WINDS. WINDS MAY GUST INTO THE TEENS FOR AN HOUR OR TWO THIS
AFTERNOON...BUT THEY SHOULD WEAKEN TOWARD SUNSET AND BECOME NEARLY
CALM OVERNIGHT. WITH INCREASED LOW LEVEL MOISTURE OVER THE
AREA...WILL HAVE TO WATCH FOR MVFR FOG DEVELOPMENT OVERNIGHT THROUGHOUT
THE AREA. FOG DEVELOPMENT IS MOST LIKELY AT THE EASTERN SITES.
HINTED AT IT AT ALL SITES...BUT KEPT IT JUST ABOVE MVFR LEVELS FOR
NOW.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...MEFFERT
LONG TERM....RP
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS ELKO NV
940 AM PDT FRI MAY 25 2012
.SYNOPSIS...A LOW PRESSURE SYSTEM WILL MOVE INTO THE GREAT BASIN
TODAY BRINGING IN COOLER AIR...SHOWERS...AND SOME THUNDERSTORMS.
SHOWERS WILL SPREAD ACROSS MOST OF THE GREAT BASIN TODAY. AS THIS
LOW MAKES ITS WAY THROUGH THE STATE THIS WEEKEND...THE MOUNTAINS
OF NORTHERN AND EAST CENTRAL NEVADA WILL ACCUMULATE SEVERAL INCHES
OF SNOW. SHOWERS WILL BE TAPERING OFF SUNDAY AND A WARMING TREND
WILL BEGIN ON MEMORIAL DAY.
&&
.UPDATE...INCREASED ISOLATED THUNDERSTORM COVERAGE ACROSS THE
REGION FOR THIS AFTERNOON AND THIS EVENING. DON`T NECESSARILY
THINK THERE WILL BE ANY MORE THUNDERSTORMS THAN PREVIOUSLY
EXPECTED...JUST DON`T FEEL CONFIDENT THAT THEY WILL BE AS CONFINED
AS PREVIOUSLY THOUGHT ESPECIALLY GIVEN MOST RECENT NAM AND GFS
LI`S PREDICTED TO BE NEGATIVE ACROSS CENTRAL NEVADA...AND GIVEN
RECENT CU BUILDUPS IN CENTRAL NEVADA. NO OTHER CHANGES AT THIS
TIME. RCM
&&
.PREV DISCUSSION... /ISSUED AT 313 AM /
SHORT TERM...TODAY THROUGH SATURDAY.
OVERVIEW. SHOWERS HAVE BEEN TAPERING OFF OVER NORTHERN NEVADA THIS
MORNING. SOME STRONGER SHOWERS BEGAN DEVELOPING OVER WESTERN
NEVADA AFTER MIDNIGHT...RENO WFO HAD SNOW SHOWERS WITH LIGHT
ACCUMULATIONS ON GRASSY AREAS AS RNO AIRPORT TEMPERATURES WERE IN
THE 40S WITH LIGHT RAIN. MODELS ARE INDICATING THE CENTER OF THE
ELONGATED INCOMING UPPER LOW TO BE OVER THE CA/OR BORDER AT THIS
TIME. THE RUC AND NAM 09Z TIMING SEEMS ABOUT RIGHT WHILE THE
GFS/ECMWF MAY BE A LITTLE LATE ON THE TIMING. THE ECMWF AND THE
NAM BOTH DEVELOP SHOWERS WHERE THEY ARE OCCURRING AT THIS TIME
HOWEVER A TAD LATE. THINK THE ENERGY AROUND THIS SYSTEM IS BEING
UNDERPLAYED. THAT BEING SAID...CANNOT GET MUCH BETTER AGREEMENT
WITH THE TRACKING OF THIS FEATURE THROUGH SATURDAY EVENING.
TODAY AND TONIGHT. THE MODEL DEPICTION OF THE UPPER JET FLOW IS
LEANING TOWARDS BALANCE AT THIS TIME AND THE CORE IS OVER CENTRAL
NEVADA THIS MORNING. HOWEVER FURTHER DIGGING IS POSSIBLE AS THE
WESTERN CORE IS WILL REMAIN SLIGHTLY STRONGER TODAY AND KEEP THE
LOW STRETCHED...ALLOWING FOR DELAYED PRECIPITATION PROGRESS INTO
CENTRAL NEVADA. CONDITIONS WILL BE VERY DRY AGAIN TODAY IN CENTRAL
NEVADA. HAVE ISSUED A RED FLAG WARNING FOR FIRE ZONES 455 AND 457
AND A WIND ADVISORY FOR ZONES 035 AND ZONES 041. WINDS WILL BE
STRONGEST OVER NORTHEASTERN NYE COUNTY AND SOUTHEASTERN PORTION OF
WHITE PINE COUNTY. THINKING GREAT BASIN PARK AREA WILL SEE
STRONGEST WINDS BUT ELY GUIDANCE HAS INCREASED THE LAST TWO MODEL
RUNS. WIND GUSTS UP TO 50 MPH EXPECTED...THE GREAT BASIN PARK BASE
COULD GET OVER 50 MPH. MOST OF THE QUANTIFIABLE PRECIPITATION
SHOULD BE OVER HUMBOLDT COUNTY TODAY AS THE UPPER ENERGY PULLS THE
MOISTURE AWAY FROM MOST OF THE CWFA. SNOW LEVELS WILL BE AROUND
6500 FEET OVER NORTHWEST NEVADA AND ANY THUNDERSTORMS THAT DEVELOP
SHOULD BE CONFINED TO THE NORTH. THE MU CAPE IS LOW SO DO NOT
EXPECT THUNDERSTORMS TO MAINTAIN OVERNIGHT AS THE CENTER OF THE
LOW MOVES INTO NEVADA.
SATURDAY. THE CENTER OF THE UPPER LOW IS PURPORTED TO MOVE
THROUGH TONOPAH AND THEN LIFT NORTH AND TRACK THROUGH NE NV. AN
INTENSE PRECIPITATION CORE IS PROPOSED BY THE MODELS STRETCHING
FROM TONOPAH THROUGH NORTHERN ELKO COUNTY. THINK THUNDERSTORM
DEVELOPMENT WILL BE EAST OF THIS CORE WHERE THE MOST INSTABILITY
IS APPEARING NEAR THE CENTER OF THE STACKED LOW AND UNDER THE
110KT JET FEATURE.
A MIX OF RAIN AND SNOW IS POSSIBLE BELOW 6500 FEET HOWEVER NO
ACCUMULATIONS ARE EXPECTED BELOW THAT LEVEL. THE RUBY MOUNTAINS
COULD ACCUMULATE 4-6 INCHES OF NEW SNOW.
NOT EXPECTING TRAVEL PROBLEMS AS THE SNOW WILL BE CONFINED TO THE
HIGHEST ELEVATIONS...BUT RECREATION ISSUES WILL ARISE FOR PERSON
OUTDOORS ON THIS HOLIDAY WEEKEND.
LONG TERM...SATURDAY NIGHT THROUGH NEXT THURSDAY. QUIET AND DRY
UNEVENTFUL WEATHER THROUGH NEXT WEEK...LITTLE TO DISCUSS. COOL NW
FLOW SUNDAY BEHIND DEPARTING STORM SYSTEM WITH AFTERNOON HIGHS
RECOVERING TO THE 60S. FLOW TRANSITIONS TO ZONAL MEMORIAL DAY AND
TUESDAY...FOLLOWED BY 500 MB RIDGING WEDNESDAY AND THURSDAY. 00Z
ECMWF/GFS BOTH FORECAST PEAK HIGH PRESSURE RIDGE INTENSITY AT 586 DM
ACROSS NEVADA ON THURSDAY. SUNNY DAYS AND CLEAR NIGHTS WITH A
WARMING TREND AND FEW CLOUDS. ALL POP GRIDS ZERO MONDAY THROUGH
THURSDAY. NEXT FRIDAY...AFTERNOON TEMPERATURES WILL APPROACH 90 IN
THE SW FLOW BEHIND THE DEPARTING RIDGE AXIS. BT
AVIATION...STRONG STORM SYSTEM IN NORTHERN CALIFORNIA AT 12Z FRI
WILL MOVE TO NORTHERN NYE COUNTY 12Z SAT. MID CLOUD DECKS WILL
THICKEN AND LOWER ACROSS NEVADA THROUGH 00Z. -SHRA MOST LIKELY AT
KWMC/NW NEVADA THROUGH 00Z. -SHRA/TSRA WILL EXPAND ACROSS NEVADA
00-12Z SAT WITH CEILINGS LOWERING TO MVFR AT TIMES.
PRIMARY IMPACT TO AVIATION OPERATIONS IS EXPECTED 12Z SAT-00Z SUN
WITH NUMEROUS -SHRA AND ISOLATED -TSRA. CIGS/VIS WILL LOWER TO MVFR
AT TIMES WITH MOUNTAINS OBSCURED. BT
FIRE WEATHER...RED FLAG WARNING HAS BEEN ISSUED FOR ZONES 455 AND 457
THROUGH 11 PM TONIGHT FOR WIND AND RH COMBINATION CONCERN. MAIN
CONCERN IS EASTERN 457 AND SOUTHEAST 455. GREAT BASIN PARK AREA
COULD EXCEED 50 MPH AT BASE LEVEL. WINDS WILL REMAIN GUSTY PAST 11 PM
TONIGHT HOWEVER RH LEVELS WILL INCREASE THUS REDUCING CONCERN.
ISOLATED THUNDERSTORMS ARE EXPECTED OVER NORTHERN ZONES
TODAY...AND EASTERN ZONES SATURDAY. TEMPERATURES WILL DROP ENOUGH
FOR SNOW ACCUMULATIONS ABOVE ABOUT 6500 FEET. SHOWERS WILL TAPER
OFF SUNDAY. A WARMING TREND WILL BEGIN ON MEMORIAL DAY AS DRIER
CONDITIONS CAN BE EXPECTED NEXT WEEK.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR NORTHEASTERN
NYE COUNTY...NORTHWESTERN NYE COUNTY...SOUTHERN LANDER COUNTY
AND SOUTHERN EUREKA COUNTY...WHITE PINE COUNTY.
WIND ADVISORY UNTIL 11 PM PDT THIS EVENING FOR NORTHEASTERN NYE
COUNTY...WHITE PINE COUNTY.
&&
$$
93/99
AREA FORECAST DISCUSSION
NWS BUFFALO NY
337 PM EDT FRI MAY 25 2012
.SYNOPSIS...
A COLD FRONT WILL SWEEP ACROSS THE REGION EARLY THIS EVENING WITH
WIDELY SCATTERED SHOWERS AND A FEW THUNDERSTORMS ENDING QUICKLY FROM
WEST TO EAST. HIGH PRESSURE WILL THEN NOSE INTO THE LOWER LAKES
REGION LATER TONIGHT INTO SUNDAY WITH A DRY AND WARM START TO THE
HOLIDAY WEEKEND. A WARM FRONT WILL LIFT SLOWLY NORTHEAST ACROSS THE
REGION LATER SATURDAY NIGHT AND SUNDAY WITH A FEW ROUNDS OF SHOWERS
AND THUNDERSTORMS POSSIBLE. MEMORIAL DAY WILL BE MAINLY DRY AND VERY
WARM AS HIGH PRESSURE BUILDS BACK INTO THE REGION.
&&
.NEAR TERM /THROUGH SATURDAY/...
WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WHICH
DEVELOPED A FEW HOURS AGO BETWEEN BUF AND ROC HAVE NOW ALL BUT
DISSIPATED...WITH JUST A FEW SPRINKLES LEFT IN WAYNE/ONTARIO
COUNTIES. THE ACTUAL COLD FRONT IS FARTHER WEST...ALL THE WAY
BACK NEAR LONDON ONTARIO AT 19Z. ANY SHOWERS OR THUNDERSTORMS
WHICH TRY TO REGENERATE WILL CONTINUE TO STRUGGLE IN THIS POORLY
SUPPORTED ENVIRONMENT.
MOISTURE CHANNEL IMAGERY SHOWS A WELL DEFINED MID LEVEL SHORTWAVE
MOVING INTO WESTERN QUEBEC THIS AFTERNOON...WITH ALL OF THE LARGE
SCALE FORCING FOR ASCENT IN THE FORM OF MID LEVEL HEIGHT FALLS
REMAINING WELL NORTH OF THE BORDER. LOW LEVEL CONVERGENCE IS WEAK IN
THE VICINITY OF THE PRE-FRONTAL TROUGH...NOT LENDING MUCH SUPPORT
FOR SUSTAINED INFLOW. THERE IS A DECENT AMOUNT OF INSTABILITY...
WITH OBJECTIVE RUC ANALYSIS SUGGESTING 1500-2000J/KG OF SBCAPE. DEEP
LAYER SHEAR IS VERY MARGINAL AT AROUND 35 KNOTS...WITH THE BULK OF
THE STRONGER SHEAR DISPLACED WELL NORTH IN ASSOCIATION WITH THE MID
LEVEL SHORTWAVE.
WITH THE ABOVE IN MIND...ANY SEVERE WEATHER POTENTIAL IS VERY
LIMITED AND WILL BE RELEGATED TO CENTRAL NY AND THE NORTH COUNTRY
WHERE THE BEST JUXTAPOSITION OF SHEAR AND INSTABILITY WILL EXIST
BRIEFLY FOR AN HOUR OR TWO DURING THE LATE AFTERNOON.
WITH REGARDS TO RAIN POTENTIAL...EXPECT STORM COVERAGE TO REMAIN
SCATTERED IN NATURE ALONG THE PRE-FRONTAL TROUGH AS IT PUSHES INTO
CENTRAL NY AND THE NORTH COUNTRY THROUGH LATE AFTERNOON. WILL
MAINTAIN CHANCE POPS AND SCATTERED WORDING THERE. FARTHER WEST...
THERE IS STILL SOME INSTABILITY AVAILABLE BEHIND THE PRE-FRONTAL
TROUGH WITH VISIBLE SATELLITE IMAGERY SHOWING AN UPSWING IN CUMULUS
FIELDS ALONG THE SOUTH SHORE OF LAKE ERIE OVER THE PAST HOUR OR TWO.
STILL CANNOT RULE OUT A BRIEF ISOLATED SHOWER OR THUNDERSTORM WITH
THE PASSAGE OF THE ACTUAL COLD FRONT DURING THE LATE AFTERNOON
HOURS...WITH THIS SMALL CHANCE PUSHING EAST ACROSS THE CWA DURING
THE EARLY EVENING.
ANY RAIN CHANCES WILL EXIT THE EASTERN LAKE ONTARIO REGION AND
CENTRAL NY BY MID EVENING WITH THE PASSAGE OF THE SURFACE COLD
FRONT. OTHERWISE HIGH PRESSURE BUILDING INTO NORTHERN ONTARIO WILL
NOSE DOWN INTO THE LOWER LAKES AND NORTHERN NY OVERNIGHT WITH
CLEARING SKIES. A SOMEWHAT DRIER AIRMASS WILL BUILD INTO THE REGION
OVERNIGHT WITH LOWS GENERALLY IN THE UPPER 50S TO NEAR 60 ON THE
LAKE PLAINS AND MID 50S IN THE COOLER SOUTHERN TIER VALLEYS AND TUG
HILL REGION.
SATURDAY THE WEAK RIDGE OF HIGH PRESSURE WILL REMAIN IN PLACE AS THE
FRONTAL ZONE STALLS OUT JUST TO OUR SOUTH AND WEST. SOME MID LEVEL
WARM ADVECTION WILL BRING AN INCREASE IN MID LEVEL CLOUD COVER FROM
WEST TO EAST...BUT STILL SHOULD SEE AT LEAST SOME SUNSHINE FILTERING
THROUGH. 850MB TEMPS STILL AROUND +13C IN THE WAKE OF THE FRONT WILL
SUPPORT HIGHS IN THE LOWER 80S ACROSS MUCH OF THE AREA WITH MID TO
UPPER 70S NORTH COUNTRY. A NORTH TO NORTHEAST WIND OFF LAKE ONTARIO
WILL KEEP THE IMMEDIATE SOUTH SHORE COOLER.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
SURFACE HIGH PRESSURE CENTERED JUST SOUTH OF JAMES BAY AND EXTENDING
SOUTH TO NEW YORK WILL SLIDE TO THE EAST AS A WARM FRONT LIFTS NORTH
THROUGH SATURDAY NIGHT. NAM AND GFS ARE IN AGREEMENT WITH LIKELY
POPS FOR SHOWERS AND THUNDERSTORMS ACROSS THE SOUTHERN TIER
OVERNIGHT...SPREADING TO CENTRAL NY DURING SUNDAY. THE PATTERN
DEPICTED BY 12Z NAM SHOWS INDICATIONS OF A MIDWESTERN MCS FROM
SATURDAY NIGHT SLIDING SOUTHEASTWARD ALONG THE THERMAL/THICKNESS
GRADIENT AND ACROSS MAJORITY OF THE FORECAST AREA ON SUNDAY. WILL GO
WITH LIKELY POPS...A NOTCH ABOVE MOST GUIDANCE...AND CONCENTRATE THE
HIGHER POPS FOR THE SOUTHERN AND CENTRAL TIER. PRECIPITABLE WATER
VALUES ARE ABOVE 1.5 INCH...THUS SOME STORMS WILL BE CAPABLE OF
HEAVY RAINS...BUT THE OVERALL QPF VALUES WILL RANGE FROM A QUARTER
TO A THIRD OF AN INCH.
LOWS ON SATURDAY NIGHT BE IN THE MID TO UPPER 50S ACROSS THE EASTERN
LAKE ONTARIO REGION WITH UPPER 50S TO LOWER 60S ELSEWHERE...EVEN MID
60S FOR THE WESTERN SOUTHERN TIER.
SUNDAY WILL BE WARMER WITH HIGHS IN THE LOWER TO MID 80S FOR MOST
OF THE FORECAST AREA...MID 70S TO AROUND 80 FOR THE NORTH COUNTRY
AND SOME LOCALES ACROSS WESTERN AND CENTRAL NY REACHING THE UPPER
80S.
UPPER RIDGING SUNDAY NIGHT AND MONDAY WILL YIELD A SUPPRESSION TO
PRECIP...AND BRING VERY WARM TEMPS. LINGERING PRECIP WILL SLIDE TO
THE EAST SUNDAY NIGHT WITH A WARM AND MUGGY NIGHT...LOWS IN THE 60S
AND UPPER 60S TO NEAR 70 FOR THE WESTERN COUNTIES. HOT AND HUMID
CONDITIONS FOR MONDAY WITH HIGHS IN THE MID 80S TO LOW 90S...AND
DEWPOINTS IN THE MID 60S TO LOW 70S. THE UPPER RIDGE SHOULD CAP THE
ATMOSPHERE...BUT WILL CARRY A LOW CHANCE OF THUNDERSTORMS DURING
MONDAY AFTERNOON AND EARLY EVENING. OVERNIGHT LOWS MONDAY NIGHT WILL
BE IN THE MID TO UPPER 60S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THE UPPER RIDGE WILL MOVE EAST OF THE REGION BY TUESDAY...ALLOWING
AN UPSTREAM TROUGH AND ATTENDANT SURFACE LOW TO SWEEP A COLD FRONT
ACROSS THE FORECAST AREA. WILL HAVE LIKELY POPS FOR SHOWERS AND
THUNDERSTORMS ON TUESDAY WITH HIGHS IN THE LOWER 80S...THEN A PATTERN
CHANGE WILL ALLOW TEMPS TO DROP BACK CLOSE TO AVERAGE FOR THE SECOND
HALF OF NEXT WEEK THROUGH NEXT WEEKEND.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
A COLD FRONT AND PRE-FRONTAL TROUGH WILL CROSS THE REGION THIS
AFTERNOON AND COMBINE WITH LAKE BREEZE BOUNDARIES TO PRODUCE WIDELY
SCATTERED CONVECTION. THE BULK OF THIS IS EXPECTED TO DEVELOP ACROSS
SOUTHERN ONTARIO AND SPREAD INTO THE SAINT LAWRENCE VALLEY...
POSSIBLY CLIPPING THE KART AREA DURING THE LATE AFTERNOON. FARTHER
SOUTH...STORM COVERAGE IS EXPECTED TO BE MORE SPARSE...WITH A FEW
STORMS DEVELOPING FROM THE GENESEE VALLEY INTO THE FINGER LAKES AND
CENTRAL NY. GIVEN SPARSE COVERAGE...WILL JUST INCLUDE A VCSH
QUALIFIER AT KIAG-KJHW-KROC FOR THE MID AFTERNOON. KBUF WILL BE
WITHIN A STABLE LAKE SHADOW FROM LAKE ERIE...AND WILL HAVE THE LEAST
CHANCE OF SEEING ANYTHING.
FOR THE MOST PART VFR WILL PREVAIL THIS AFTERNOON WITH A PERIOD OF
MID LEVEL CLOUDINESS. ANY SHOWERS AND STORMS THAT DO FORM MAY
PRODUCE VERY BRIEF/ISOLATED AREAS OF MVFR/IFR VSBY IN HEAVIER RAIN.
SCATTERED CONVECTION WILL QUICKLY END FROM WEST TO EAST DURING THE
LATE AFTERNOON AND EARLY EVENING FOLLOWING THE COLD FRONTAL PASSAGE.
EXPECT MAINLY CLEAR SKIES OVERNIGHT BEFORE MID LEVEL CLOUDS INCREASE
BY SUNDAY MORNING IN RESPONSE TO WARM ADVECTION ALOFT.
EXPECT DRY CONDITIONS ON SATURDAY WITH VFR PREVAILING AS A BUBBLE OF
HIGH PRESSURE NOSES OUT OF ONTARIO AND INTO THE LOWER LAKES.
OUTLOOK...
SUNDAY...VFR/MVFR WITH SCATTERED SHOWERS AND STORMS.
MONDAY...MAINLY VFR.
TUESDAY...AREAS OF MVFR IN SHOWERS/THUNDERSTORMS.
WEDNESDAY...MAINLY VFR.
&&
.MARINE...
SOUTHWEST WINDS IN THE 10-20 KNOT RANGE WILL CONTINUE THROUGH EARLY
EVENING WITH THE PASSAGE OF A COLD FRONT...PRODUCING WAVES IN THE
2-3 FOOT RANGE BRIEFLY AT THE NORTHEAST ENDS OF LAKES ERIE AND
ONTARIO. WINDS AND WAVES WILL QUICKLY DIMINISH BY LATE EVENING AS A
RIDGE OF HIGH PRESSURE NOSES INTO THE LOWER LAKES REGION.
WINDS WILL REMAIN LIGHT FOR THE HOLIDAY WEEKEND AND THE TRADITIONAL
KICKOFF TO THE BOATING SEASON ON THE LOWER LAKES. EXPECT WAVES TO
RUN UNDER 2 FEET THROUGH MONDAY WITH A WEAK PRESSURE GRADIENT IN
PLACE. A FEW THUNDERSTORMS ARE POSSIBLE ON SUNDAY...WITH LOCALLY
HIGHER WINDS AND WAVES POSSIBLE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...HITCHCOCK
MARINE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS NORMAN OK
530 PM CDT FRI MAY 25 2012
.AVIATION...
OUTSIDE CHANCE FOR A STORM ACROSS FAR WESTERN OKLAHOMA THIS
EVENING... BUT CHANCE REMAINS TOO LOW TO MENTION AT THIS TIME.
OTHERWISE... GUSTY SOUTH WINDS WILL REMAIN SO OVERNIGHT WITH A
GENERAL INCREASE IN MID AND HIGH CLOUDS OVERNIGHT. THERE WILL BE A
WINDOW LATE TONIGHT INTO FIRST PART OF MORNING FOR MVFR CEILINGS AS
STRATUS ONCE AGAIN DEVELOPS.
30
&&
.PREV DISCUSSION... /ISSED 305 PM CDT FRI MAY 25 2012/
.DISCUSSION...
DESPITE STRONG CAPPING INVERSION... LOCAL WRF... RUC AND HRRR
HAVE SHOWN A CONSISTENT SIGNAL OF ISOLATED CONVECTION DEVELOPING
ALONG THE DRYLINE IN OR NEAR WESTERN OKLAHOMA. EVEN IF STORMS
DEVELOP... WOULD EXPECT THEM TO BE ISOLATED AND THEREFORE 20 POPS
MIGHT BE A BIT AGGRESSIVE... BUT WILL LEAVE 20S IN THE WEST FOR
THIS EVENING. IF STORMS DO GO... THE ATMOSPHERIC INSTABILITY IS
HIGH ENOUGH THAT SEVERE WEATHER WOULD BE LIKELY. PRECIPITATION
CHANCES ARE TOO LOW TO MENTION ON SATURDAY... BUT RAIN CHANCES
RETURN BEGINNING SUNDAY AS A STORM SYSTEM MOVES INTO THE PLAINS
/ALBEIT MAINLY TO OUR NORTH/ AND THEN AS A SURFACE FRONT MOVES
INTO THE AREA MONDAY. THERE STILL IS DISAGREEMENT ON WHERE THE
SURFACE FEATURES ARE LOCATED AS UPPER PATTERN EVOLVES INTO ZONAL
FLOW EARLY-MID WEEK NEXT WEEK... BUT PRECIPITATION CHANCES REMAIN
JUSTIFIED. AS PATTERN CONTINUES TO SHIFT TO A NORTHWEST FLOW ALOFT
LATER IN THE WEEK... THERE ARE HINTS OF POSSIBLE MCS DEVELOPMENT
IN THE PLAINS. THIS HAS BEEN THE GENERAL FORECAST FOR A DAY OR TWO
AND HAVE NOT MADE ANY SIGNIFICANT CHANGES IN THE EXTENDED PERIODS.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 73 91 68 89 / 10 10 10 10
HOBART OK 72 95 68 92 / 20 10 10 20
WICHITA FALLS TX 74 94 68 92 / 10 10 10 10
GAGE OK 73 93 68 92 / 20 10 10 20
PONCA CITY OK 73 91 70 89 / 10 10 10 10
DURANT OK 71 90 67 89 / 0 0 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORMAN OK
305 PM CDT FRI MAY 25 2012
.DISCUSSION...
DESPITE STRONG CAPPING INVERSION... LOCAL WRF... RUC AND HRRR
HAVE SHOWN A CONSISTENT SIGNAL OF ISOLATED CONVECTION DEVELOPING
ALONG THE DRYLINE IN OR NEAR WESTERN OKLAHOMA. EVEN IF STORMS
DEVELOP... WOULD EXPECT THEM TO BE ISOLATED AND THEREFORE 20 POPS
MIGHT BE A BIT AGGRESSIVE... BUT WILL LEAVE 20S IN THE WEST FOR
THIS EVENING. IF STORMS DO GO... THE ATMOSPHERIC INSTABILITY IS
HIGH ENOUGH THAT SEVERE WEATHER WOULD BE LIKELY. PRECIPITATION
CHANCES ARE TOO LOW TO MENTION ON SATURDAY... BUT RAIN CHANCES
RETURN BEGINNING SUNDAY AS A STORM SYSTEM MOVES INTO THE PLAINS
/ALBEIT MAINLY TO OUR NORTH/ AND THEN AS A SURFACE FRONT MOVES
INTO THE AREA MONDAY. THERE STILL IS DISAGREEMENT ON WHERE THE
SURFACE FEATURES ARE LOCATED AS UPPER PATTERN EVOLVES INTO ZONAL
FLOW EARLY-MID WEEK NEXT WEEK... BUT PRECIPITATION CHANCES REMAIN
JUSTIFIED. AS PATTERN CONTINUES TO SHIFT TO A NORTHWEST FLOW ALOFT
LATER IN THE WEEK... THERE ARE HINTS OF POSSIBLE MCS DEVELOPMENT
IN THE PLAINS. THIS HAS BEEN THE GENERAL FORECAST FOR A DAY OR TWO
AND HAVE NOT MADE ANY SIGNIFICANT CHANGES IN THE EXTENDED PERIODS.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 73 91 68 89 / 10 10 10 10
HOBART OK 72 95 68 92 / 20 10 10 20
WICHITA FALLS TX 74 94 68 92 / 10 10 10 10
GAGE OK 73 93 68 92 / 20 10 10 20
PONCA CITY OK 73 91 70 89 / 10 10 10 10
DURANT OK 71 90 67 89 / 0 0 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
347 PM CDT FRI MAY 25 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
346 PM CDT FRI MAY 25 2012
AT 3 PM...DOPPLER RADAR INDICATED SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS NORTHERN IOWA...AND SOUTH-CENTRAL AND
SOUTHWEST MINNESOTA. THIS PRECIPITATION IS ASSOCIATED WITH
STRONG 600-700 MB FRONTOGENESIS. FURTHER SOUTH ACROSS SOUTHEAST
NEBRASKA...SOUTHERN IOWA...AND NORTHERN MISSOURI...THERE IS A MORE
ROBUST AREA OF SHOWERS AND THUNDERSTORMS. THIS IS ASSOCIATED WITH
STRONG 800 TO 700 MB FRONTOGENESIS.
FOR TONIGHT...THE LATEST RAP ALONG WITH SEVERAL OF THE MESO MODELS
SUGGEST THAT THE 600-700 MB FRONTOGENESIS WILL SHIFT NORTH TOWARD
THE INTERSTATE 90 CORRIDOR THIS EVENING...AND BE LOCATED BETWEEN
THE INTERSTATE 90 AND 94 CORRIDOR AFTER MIDNIGHT. THE 800-700 MB
FRONTOGENESIS SHIFTS QUICKLY NORTH ACROSS IOWA TONIGHT. THESE
FRONTOGENESIS BANDS WILL LIKELY BE THE FOCUS FOR THE DEVELOPMENT
OF SHOWERS AND THUNDERSTORMS. THE BEST INSTABILITY REMAINS TO THE
SOUTH AND WEST FOR TONIGHT. AS A RESULT...THE SEVERE WEATHER
CHANCES LOOK LOW FOR LATE TONIGHT.
ON SATURDAY AND SATURDAY NIGHT...THE MODELS CONTINUE TO SHOW THAT
THE AREAS OF ELEVATED BANDS OF FRONTOGENESIS WILL MOVE NORTH ACROSS
THE FORECAST AREA. A MODERATE SOUTHERLY FLOW BRINGS MOIST AND
UNSTABLE AIR NORTHWARD ACROSS THE REGION. THE 0-3 KM MOST UNSTABLE
CAPES GRADUALLY CLIMB DURING THE DAY. BY LATE AFTERNOON...THEY ARE
RUNNING 1 TO 3K ALONG AND SOUTH OF THE INTERSTATE 94 CORRIDOR...
AND FROM 3 TO 4K ACROSS NORTHEAST IOWA AND SOUTHWEST WISCONSIN.
THE SIGNIFICANT TORNADO PARAMETER IS VERY HIGH ACROSS NORTHEAST
IOWA AND SOUTHWEST WISCONSIN. HOWEVER...THE BOTH THE SURFACE BASED
AND ML CINS INCREASE SO MUCH THAT THE CONVECTION BECOMES ELEVATED.
BUFKIT MODEL SOUNDINGS SHOW THAT THE CAPES WILL BE LOCATED ABOVE
10K FEET. WITH THE STORMS BEING SO ELEVATED...THIS ELIMINATES THE
SHEAR IN THE LOWEST 3 KILOMETERS WHICH TAKES VERY FAVORABLE BULK
SHEAR FOR SUPERCELLS AND MAKES THEM LESS FAVORABLE. TAKING ALL OF
THIS INTO ACCOUNT...THINKING THAT THE SEVERE WEATHER THREAT LOOKS
TO BE SLIGHT WITH HAIL BEING THE MAIN THREAT.
ON SUNDAY...THERE MAY BE A FEW LINGERING SHOWERS AND THUNDERSTORMS
ACROSS NORTH-CENTRAL WISCONSIN DURING THE EARLY MORNING...AND THEN
MOVES NORTH OF THE AREA. VERY WARM MOVES IN ALOFT. 850 MB
TEMPERATURES CLIMB TO AROUND 22C IN THE GFS AND ECMWF...AND TO 24C
IN THE NAM/WRF. IF SOILS DO NOT MOISTEN UP SIGNIFICANTLY OVER THE
NEXT 36 HOURS...THERE COULD POTENTIALLY BE A VERY STEEP LOW LEVEL
LAPSE RATES WHICH WOULD RESULT IN WARMER TEMPERATURES. FOR
NOW...WENT WITH THE LOWER AND MID 90S ALONG AND SOUTH OF THE
INTERSTATE 94 CORRIDOR...AND NEAR 90 ACROSS NORTH-CENTRAL WISCONSIN.
IN ADDITION TO SUNDAYS TEMPERATURES BEING A BIT PROBLEMATIC...THE
DEW POINTS MAY ALSO BE AN ISSUE. THE MODELS SUGGEST THAT THERE
WILL BE IN THE UPPER 60S. HOWEVER THE BUFKIT MODEL SOUNDINGS SHOW
THAT THERE WILL BE A LOT OF DRY AIR ALOFT WHICH HAS BEEN ADVECTED
OFF OF THE HIGH PLAINS. MIXING DOWN THIS DRY AIR ALOFT RESULTS IN
DEW POINTS IN THE 40S AND 50S.
ON SUNDAY NIGHT...THE MODELS CONTINUE TO STRUGGLE ON HOW FAR EAST
WILL THE COLD FRONT GET. ALSO THE CAPES MAY BE OVER DONE IF THE
DEW POINTS ARE TOO HIGH. WHILE THE INSTABILITY MAY BE IN
QUESTION...THE 0-6KM SHEAR IS FAVORABLE FOR THE DEVELOPMENT OF
SUPERCELL THUNDERSTORMS. IF SEVERE WEATHER HAPPENED TO
DEVELOP...LARGE HAIL AND DAMAGING WINDS WOULD BE THE MAIN CONCERNS.
.LONG TERM...MEMORIAL DAY THROUGH FRIDAY
346 PM CDT FRI MAY 25 2012
THE MODELS CONTINUE TO SHOW THAT A STRONG SHORT WAVE TROUGH WILL
FLATTEN OUT THE UPPER LEVEL RIDGE ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY. AS THIS OCCURS...A STRONG COLD FRONT WILL MOVE EAST
ACROSS THE FORECAST AREA ON MEMORIAL DAY. DUE TO CLOUDS AND
PRECIPITATION...THE CAPES LOOK TO BE LOW WEST OF THE MISSISSIPPI
RIVER. THIS WOULD GREATLY LIMIT THE SEVERE WEATHER POTENTIAL.
MEANWHILE FURTHER EAST...SOME MORNING SUNSHINE MAY ALLOW ML CAPES
TO CLIMB INTO THE 1 TO 2K RANGE. WITH THIS INSTABILITY AND 0-6 KM
SHEAR GREATER THAN 40 KNOTS...A FEW OF THUNDERSTORMS MAY BECOME
SEVERE ACROSS WISCONSIN. MAIN THREATS LOOK TO LARGE HAIL...
DAMAGING WINDS...AND MAYBE AN ISOLATED TORNADO.
&&
.AVIATION...THROUGH 18Z SATURDAY
1226 PM CDT FRI MAY 25 2012
FORECASTING VFR CONDITIONS THROUGH THE PERIOD AT THIS POINT. WARM
FRONT OVER MISSOURI IS EXPECTED TO MOVE NORTH TOWARD THE AREA
THROUGH TONIGHT AND SATURDAY MORNING. AS IT DOES...A BAND OF MID
LEVEL FRONTOGENESIS WILL DEVELOP NORTH OF THE FRONT AND OVER THE
AREA TONIGHT AND CONTINUE INTO SATURDAY MORNING. THE BIG CONCERN
ON WHERE ANY SHOWERS AND STORMS DEVELOP. THE 25.12Z NAM SUGGESTS
THE BEST MOISTURE TRANSPORT WILL BE INTO THE FRONT OVER SOUTH
DAKOTA INTO WESTERN IOWA AHEAD OF A DEVELOPING AREA OF LOW
PRESSURE OVER NEBRASKA. THIS WOULD PLACE THE GREATEST
CONCENTRATION OF CONVECTION OFF TO THE WEST WITH THE POSSIBILITY
OF SCATTERED ACTIVITY FARTHER EAST IN THE FRONTOGENESIS BAND. THE
25.06Z HI-RES ARW AND NMM DO NOT OFF ANY CLARITY TO THE SITUATION
AS THEY OFFER DIFFERING SOLUTIONS. THE ARW WOULD SUGGEST MOST OF
THE AREA STAYING DRY TONIGHT WITH A MCS COMING THROUGH SATURDAY
MORNING WHILE THE NMM WANTS TO KEEP EVERYTHING GENERALLY SOUTH OF
THE AREA. CONFIDENCE IS LOW ON HOW THIS WILL PLAY OUT TONIGHT AND
HAVE JUST GONE WITH VICINITY THUNDER FOR BOTH TAF SITES AS TOO
DIFFICULT TO PINPOINT A TIME FOR CATEGORICAL THUNDER TO OCCUR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
251 PM CDT FRI MAY 25 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1226 PM CDT FRI MAY 25 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
317 AM CDT FRI MAY 25 2012
MAIN FORECAST CONCERNS ARE ON CONVECTIVE POTENTIAL THROUGHOUT...
ALONG WITH ANY SEVERE WEATHER CONCERNS.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED DEEP TROUGHING OVER NORTHERN CALIFORNIA (2-2.5 STANDARD
DEVIATIONS BELOW NORMAL)...RIDGING BUILDING UP OVER THE CENTRAL
PLAINS...AND A POTENT SHORTWAVE TROUGH MOVING THROUGH UPPER
MICHIGAN. THE FORECAST AREA LIES IN SUBSIDENCE IN THE WAKE OF THE
SHORTWAVE TROUGH...WHICH HAS RESULTED IN DRYING AND CLEARING SKIES.
00Z MPX SOUNDING SHOWED SOME OF THE DRYING COMING IN ABOVE 700MB.
SURFACE COLD FRONT ASSOCIATED WITH THE POTENT SHORTWAVE EXTENDS FROM
LAKE MICHIGAN...SOUTHWEST TO SPRINGFIELD MO...THEN TURNS INTO A WARM
FRONT CONNECTING TO A LOW IN NORTHEAST NEW MEXICO. SOUTH OF THAT
WARM FRONT...DEWPOINTS ARE NEAR 70. COMPARE THESE TO THE AROUND 50
DEWPOINTS THAT HAVE ADVECTED IN BEHIND THE FRONT OVER THE FORECAST
AREA.
TODAY AND TONIGHT...UPPER TROUGHING OVER NORTHERN CALIFORNIA IS
FORECAST TO DIG SOUTHWARD THROUGH THE STATE...CAUSING SIGNIFICANT
HEIGHT RISES AT 500MB UP AND DOWN THE MISSISSIPPI RIVER VALLEY.
BETWEEN 12Z TODAY AND 12Z SATURDAY...500MB HEIGHTS RISE 180 METERS
AT LA CROSSE. ACCOMPANYING THESE SIGNIFICANT HEIGHT RISES WILL BE AN
INTENSIFYING LOW LEVEL JET OVER THE PLAINS...PROPELLING THE WARM
FRONT IN OKLAHOMA NORTHWARD AT A RAPID CLIP. BY 12Z SATURDAY...VERY
GOOD AGREEMENT EXISTS THAT THE WARM FRONT SHOULD BE APPROACHING I-80
IN IOWA. THE MAIN CONCERN IS PRECIPITATION CHANCES GIVEN SUCH RAPID
CHANGES GOING ON. EXPECT THE MORNING TO REMAIN DRY WITH THE FORECAST
AREA STILL FEELING SUBSIDENCE IN THE WAKE OF LAST NIGHTS SHORTWAVE
TROUGH. DURING THE AFTERNOON...INCREASING 800MB TO 700MB MOISTURE
TRANSPORTED IS NOTED...WHICH WILL AT A MINIMUM CAUSE AN INCREASE IN
ALTOSTRATUS. SOME MODELS HAVE SUGGESTED SOME LIGHT SHOWERS
DEVELOPING OUT OF THESE CLOUDS...MOSTLY WEST OF THE MISSISSIPPI
RIVER AND EVEN THAT MOSTLY WEST OF THE FORECAST AREA. FORECAST
SOUNDINGS DO DEPICT QUITE A BIT OF DRY AIR BELOW THE ALTOSTRATUS...
WHICH MAY ABSORB SOME OF THE RAIN. THEREFORE...HAVE KEPT ANY PRECIP
TO SPRINKLES THIS AFTERNOON...AND ONLY WEST OF THE MISSISSIPPI
RIVER. THINGS GET A BIT TRICKY TONIGHT. AS THE LOW LEVEL JET AND
MOISTURE TRANSPORT INCREASES...NUMEROUS CONVECTION IS LIKELY TO
DEVELOP OVER IOWA NORTH OF THE WARM FRONT. THE QUESTION IS WILL IT
TURN INTO AN MCS OR NOT...SINCE THAT WOULD LIKELY SLOW THE WARM
FRONTS NORTHWARD PROGRESS FOR LATER IN THE FORECAST...AND IMPACT
HOW MUCH PRECIPITATION IMPACTS THE AREA GIVEN NORTHWEST TO SOUTHEAST
ORIENTED CORFIDI VECTORS. MAIN UPPER JET IS WELL TO THE NORTH OVER
NORTHERN MINNESOTA...SO NO UPPER DIVERGENCE HELP. 500MB HEIGHTS ARE
RISING WITH NO SHORTWAVE EVIDENT...SO NO SUPPORT THERE. IT SEEMS THE
ONLY THING GOING FOR AN MCS IS THE MOISTURE TRANSPORT...WHICH IS
BROAD. THEREFORE...THINK WHAT MOST OF THE MODELS DEPICT WITH QPF...
I.E SHOWERS AND THUNDERSTORMS...GRADUALLY LIFTING NORTH WITH THE
FRONT SEEMS REASONABLE. WITH WARM CLOUD DEPTHS APPROACH 3.5-4
KM...ANY SHOWERS LIKELY TO PRODUCE HEAVY RAIN...THOUGH LACK OF AN
MCS OR STATIONARY BOUNDARY PREVENTS ANY FLOOD CONCERN AT THIS TIME.
ALTHOUGH 1-6 KM SHEAR IS 40 OR MORE KNOTS...SKINNY CAPE AND HIGH
FREEZING LEVELS MAY KEEP THE MAIN THREAT BESIDES RAIN TO GUSTY WINDS
FROM THE STORMS. COOLER DAY ON TAP TODAY WITH 850MB TEMPS OF 8-10C
AND INCREASING AFTERNOON CLOUDS. HIGHS IN THE 70S SEEM REASONABLE.
WENT WITH A BLEND OF GUIDANCE FOR LOWS TONIGHT.
SATURDAY THROUGH SUNDAY...WARM FRONT LOOKS TO CONTINUE ITS NORTHWARD
PROGRESS AS THE TROUGHING IN CALIFORNIA LIFTS INTO THE HIGH PLAINS
LATE SUNDAY. WARM FRONT SHOULD APPROACH I-90 BY 00Z SUNDAY. SOUTH OF
THIS FRONT...A PLUME OF HOT AND HUMID AIR REFLECTED BY 850MB TEMPS
OF 20C PLUS...AS WELL AS THOSE DEWPOINTS SEEN IN OKLAHOMA...WILL
ADVECT IN. THEREFORE...PLENTIFUL CAPE IS LIKELY ON AND ADVECTING
NORTH WITH THE FRONT. PROBLEM WE MAY HAVE CONTEND WITH FOR
SATURDAY...AFTER ANY MORNING CONVECTION RELATED TO TONIGHT...IS
CAPPING ADVECTING NORTH OF THE FRONT AT 750MB. MLCIN VALUES ARE
SUBSTANTIAL...UPWARDS OF 200 J/KG OR SO FOR THE AFTERNOON. MUCH OF
THE MODEL QPF ON SATURDAY...PARTICULARLY AFTERNOON...SEEMS TO BE
RELATED TO BELOW THE CAP. THEREFORE...NOT SURE HOW MUCH OF IT IS
REAL. HAVE LOWERED PRECIPITATION CHANCES IN THE AFTERNOON SOUTH OF
I-94 AS A RESULT. THIS MATCHES TOO WITH THE 25.00Z REGIONAL
CANADIAN...LOCAL WRF-ARW RUN AND HIRES WRF-ARW RUN FROM NCEP. BEST
CHANCES FOR PRECIP IN THE AFTERNOON IS NORTH OF I-94 WHERE LESS CAP
EXISTS. CAP...WARM AIR AND FRONT SHOULD CONTINUE TO LIFT NORTH
ACROSS THE AREA SATURDAY NIGHT...THOUGH DID KEEP SOME CHANCES NORTH
OF I-94 WHERE RE-INVIGORATED MOISTURE TRANSPORT MAY ALLOW CONVECTION
TO GO. VERY WARM NIGHT ANTICIPATED SOUTH OF THE FRONT. SUNDAY SHOULD
BE MOSTLY DRY WITH THE HOTTEST DAY OF THE YEAR THUS FAR. 850MB TEMPS
OF 22C AT 18Z PLUS PLENTY OF SUN AND A BREEZY SOUTHWEST WIND
EXPECTED TO SUPPORT HIGHS MOSTLY IN THE 90S. STAYED AT THE HIGH END
OF GUIDANCE FOR HIGHS GIVEN THE SETUP. IF TEMPERATURES LOOK WARMER
IN LATER FORECASTS...MAY NEED TO CONSIDER A HEAT ADVISORY.
SUNDAY NIGHT...TROUGH OVER THE HIGH PLAINS IS PROGGED TO START
MOVING EAST...DRIVING A COLD FRONT TO NEAR I-35 BY 12Z MONDAY. DPVA
AHEAD OF THIS TROUGH...ALONG WITH SOME RIGHT ENTRANCE REGION
SUPPORT...LOW TO MID-LEVEL FRONTOGENESIS ALONG THE FRONT AND
INSTABILITY WILL ALL COME TOGETHER TO PRODUCE A NORTHEAST TO
SOUTHWEST ORIENTED BAND OF CONVECTION. MUCH OF THIS CONVECTION
SHOULD STAY WEST OF THE AREA IN THE EVENING...THEN MOVE INTO
SOUTHEAST MINNESOTA...NORTHEAST IOWA AND POSSIBLY NORTH CENTRAL
WISCONSIN AFTER MIDNIGHT. STORMS ARE LIKELY TO BE SEVERE WHEN THEY
INITIALLY FORM IN THE EVENING WEST OF THE AREA...AS INDICATED TOO BY
THE SPC DAY 3 OUTLOOK SEVERE PROBABILITIES. NOT SURE IF THEY WILL BE
SEVERE BY THE TIME THEY REACH THE FORECAST AREA...THOUGH...AS THE
MLCAPE REALLY TAILS OFF THROUGH THE NIGHT. THE SHEAR IS THERE...
THOUGH...ENOUGH PROBABLY TO WARRANT THE GENERAL SLIGHT RISK. WITH A
BREEZY NIGHT AND COLD FRONT/PRECIPITATION NOT COMING UNTIL
LATE...ANTICIPATING ANOTHER WARM NIGHT. LOWS MAY NEED TO BE RAISED
MORE THAN CURRENTLY FORECAST.
.LONG TERM...MONDAY THROUGH THURSDAY NIGHT
317 AM CDT FRI MAY 25 2012
AFTER A HOT SUNDAY...THE LONG TERM PERIOD FEATURES A PATTERN SHIFT
TO ONE COOLER THAN NORMAL. THIS IS IN RESPONSE TO THE TROUGHING OVER
THE NORTHERN PLAINS SUNDAY NIGHT EVENTUALLY BECOMING STUCK OVER
ONTARIO AND THE GREAT LAKES REGION. IN FACT...COME THURSDAY...THERE
IS A RE-ENFORCING POTENT SHORTWAVE DROPPING SOUTH THROUGH THE
PLAINS.
MAIN FOCUS ON THE LONG TERM PERIOD IS MONDAY...IN PARTICULAR THE
COLD FRONT COMING ACROSS THE FORECAST AREA WITH THE UPPER TROUGH.
MODELS ARE IN GOOD AGREEMENT NOW WITH THE FRONT CROSSING THE AREA
MID-DAY. HOW MUCH CONVECTION WILL BE ON THIS FRONT IS A QUESTION.
THE CONVECTION FROM SUNDAY NIGHT MAY END UP FALLING APART DUE TO
LOSS OF INSTABILITY. THEN DURING THE AFTERNOON...DEPENDING
SPECIFICALLY ON TIMING...AFTER DAYTIME INSTABILITY BUILDS THE
CONVECTION COULD FIRE ON THE FRONT AFTER IT HAS PASSED THROUGH THE
AREA. THEREFORE...PRECIPITATION CHANCES ARE ONLY 30-50 AT THIS TIME.
A FEW MODELS...THE 25.00Z ECMWF AND OUR LOCAL WRF RUN...SUGGEST THE
POTENTIAL FOR A NEARLY DRY FRONTAL PASSAGE. IF THERE IS ANY
POTENTIAL FOR SEVERE...SEEMS LIKE THAT WOULD OCCUR IN OUR FAR
EASTERN AREAS.
MAINLY DRY AND COOLER WEATHER LOOKS TO PREVAIL FOR MONDAY NIGHT
THROUGH TUESDAY NIGHT THANKS TO SUBSIDENCE ON THE BACK SIDE OF THE
UPPER TROUGH. 20-40 PERCENT CHANCES OF SHOWERS ENTER THE FORECAST
FOR WEDNESDAY THROUGH THURSDAY...ASSOCIATED WITH THAT POTENT
SHORTWAVE DROPPING DOWN THROUGH THE PLAINS. NOTE...THOUGH...THAT IT
IS ENTIRELY POSSIBLE THIS SHORTWAVE AND ITS ASSOCIATED PRECIPITATION
STAYS AWAY FROM THE AREA ...THUS ONLY THE 20-40 PERCENT VALUES.
ONE THING WE NEED TO WATCH OUT FOR TOO MAY BE FROST LATER OUT. THE
25.00Z ECMWF SHOWS 850MB TEMPS OVER TAYLOR COUNTY DROPPING TO AROUND
0C AT 12Z WEDNESDAY WITH HIGH PRESSURE BUILDING IN. RIGHT NOW NO
FROST OR EVEN TEMPERATURES CLOSE TO FROST IS IN THE FORECAST...BUT
SOMETHING AGAIN TO WATCH.
&&
.AVIATION...THROUGH 18Z SATURDAY
1226 PM CDT FRI MAY 25 2012
FORECASTING VFR CONDITIONS THROUGH THE PERIOD AT THIS POINT. WARM
FRONT OVER MISSOURI IS EXPECTED TO MOVE NORTH TOWARD THE AREA
THROUGH TONIGHT AND SATURDAY MORNING. AS IT DOES...A BAND OF MID
LEVEL FRONTOGENESIS WILL DEVELOP NORTH OF THE FRONT AND OVER THE
AREA TONIGHT AND CONTINUE INTO SATURDAY MORNING. THE BIG CONCERN
ON WHERE ANY SHOWERS AND STORMS DEVELOP. THE 25.12Z NAM SUGGESTS
THE BEST MOISTURE TRANSPORT WILL BE INTO THE FRONT OVER SOUTH
DAKOTA INTO WESTERN IOWA AHEAD OF A DEVELOPING AREA OF LOW
PRESSURE OVER NEBRASKA. THIS WOULD PLACE THE GREATEST
CONCENTRATION OF CONVECTION OFF TO THE WEST WITH THE POSSIBILITY
OF SCATTERED ACTIVITY FARTHER EAST IN THE FRONTOGENESIS BAND. THE
25.06Z HI-RES ARW AND NMM DO NOT OFF ANY CLARITY TO THE SITUATION
AS THEY OFFER DIFFERING SOLUTIONS. THE ARW WOULD SUGGEST MOST OF
THE AREA STAYING DRY TONIGHT WITH A MCS COMING THROUGH SATURDAY
MORNING WHILE THE NMM WANTS TO KEEP EVERYTHING GENERALLY SOUTH OF
THE AREA. CONFIDENCE IS LOW ON HOW THIS WILL PLAY OUT TONIGHT AND
HAVE JUST GONE WITH VICINITY THUNDER FOR BOTH TAF SITES AS TOO
DIFFICULT TO PINPOINT A TIME FOR CATEGORICAL THUNDER TO OCCUR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
317 AM CDT FRI MAY 25 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1105 AM MDT FRI MAY 25 2012
.DISCUSSION...
AREAS OF RAIN HAVE DECREASED IN COVERAGE SINCE 12Z AND CLOUD TOPS
HAVE WARMED. MOST OF THE ACTIVITY AT 1530Z WAS LOCATED FROM WESTERN
CARBON TO NIOBRARA COUNTIES. THE FLOW ALOFT WILL CONTINUE TO BACK
THROUGH THE REST OF TODAY AND A SHORTWAVE TROUGH WILL LIFT INTO
NORTHEAST WYOMING. THE CURRENT AREA OF RAIN OVER EAST CENTRAL
WYOMING WILL CONTINUE TO SLOWLY DIMINISH WITH THE PASSAGE OF THE
SHORTWAVE TROUGH. THE ATMOSPHERE BECOMES SLIGHTLY UNSTABLE THIS
AFTERNOON ESPECIALLY OVER SOUTH CENTRAL WYOMING WHERE THERE ARE MORE
BREAKS IN THE CLOUD COVER. THAT WILL ALLOW SOME SHOWERS AND STORMS
TO REDEVELOP OVER THE CWA...ESPECIALLY IN THE WEST AND NORTH PORTIONS.
CLOUD BASES HAVE CONTINUED TO SLOWLY LIFT OVER MOST OF THE CWA AND
WILL CONTINUE TO DO SO THROUGH THE AFTERNOON. SKIES WILL STILL BE
MOSTLY CLOUDY OVER THE AREA AND WILL HELP HOLD TEMPERATURES DOWN A
BIT FROM PREVIOUS FORECAST. THE BOUNDARY LAYER MOIST SOUTHEAST WIND
FLOW ACTUALLY INCREASES TODAY AS THE SURFACE LOW DEEPENS OVER UTAH
AND WESTERN COLORADO. DENSE FOG CONTINUES AT 16Z OVER THE SOUTHERN
LARAMIE RANGE. CONDITIONS SHOULD GRADUALLY IMPROVE...BUT MAY NEED
TO EXTEND THE PREVIOUSLY ISSUED DENSE FOG ADVISORY. ALSO...WIND
GUSTS AROUND 50 MPH HAVE BEEN NOTED IN THE LARAMIE VALLEY DURING THE
MID MORNING HOURS WITH THOSE SPEEDS CONTINUING THROUGH THE AFTERNOON.
&&
.PREVIOUS DISCUSSION.../ISSUED AT 749 AM MDT FRI MAY 25 2012/...
.DISCUSSION...
DENSE FOG SHOULD CONTINUE AT LEAST THROUGH MIDDAY OVER AND NEAR THE
SOUTHERN LARAMIE RANGE. IN A RECENT UPDATE WENT AHEAD AND ISSUED A
DENSE FOG ADVISORY FOR THAT AREA UNTIL 18Z. ALSO MOST OF THE
SHOWERS PER AREA RADARS WERE CURRENTLY OVER THE NORTH AND WEST PARTS
OF THE CWA...SO HAVE ADJUSTED POPS THIS MORNING TO REFLECT THE
CURRENT LOCATION OF THE LIGHT RAIN. SNOW ALSO HAS BEEN FALLING
ABOVE 8500 FEET MSL IN THE MOUNTAINS AND HAVE ADDED TO THE FORECAST
FOR THE MORNING.
&&
.PREVIOUS DISCUSSION.../ISSUED AT 543 AM MDT FRI MAY 25 2012/...
.AVIATION...12Z TAFS
LATEST SATELLITE IMAGERY AND AREA METARS SHOWING LOW CLOUDS OVER
NORTHEASTERN COLORADO. WYDOT WEBCAMS SHOWING THE SOUTHERN LARAMIE
RANGE IN LOW CLOUDS AND FOG. THINKING IS...THERE WILL BE A PERIOD
THIS MORNING WHERE CHEYENNE WILL GO DOWN. THIS IS SUPPORTED BY THE
LATEST HRRR GUIDANCE. MORE WIDESPREAD AND DENSER CLOUDS EXPECTED
THIS EVENING AFTER 00Z WHEN ALL NEBRASKA PANHANDLE AIRPORTS AND
KCYS LOOK TO GO DOWN TO LIFR...PERSISTING THROUGH SATURDAY AFTERNOON.
CLAYCOMB
&&
.PREV DISCUSSION... /ISSUED 407 AM MDT FRI MAY 25 2012/
SHORT TERM...TODAY THROUGH SATURDAY.
TODAY...AS THE MODELS HAVE BEEN PREDICTING...SCATTERED TO NUMEROUS
RAIN SHOWERS HAVE MOVED INTO PORTIONS OF SOUTHEAST WYOMING AND
WESTERN NEBRASKA ASSOCIATED WITH WARM AIR ADVECTION IN THE MID
LEVELS AND POSITIVE THETA-E ADVECTION. THIS AREA OF SHOWERS IS
EXPECTED TO GRADUALLY SHIFT NORTHWARD THIS MORNING AND LIE ACROSS
OUR NORTHERN COUNTIES THIS AFTERNOON.
THIS AFTERNOON...MOIST LOW LEVEL SOUTHEAST WINDS WILL CONTINUE EAST
OF INTERSTATE 25...ADVECTING LOW LEVEL MOISTURE NORTHWESTWARD. A LOW
AND MID LEVEL THETA-E RIDGE AXIS WILL DEVELOP ALONG INTERSTATE
25...AND IF ENOUGH CLEARING OCCURS...A FEW STRONG THUNDERSTORMS MAY
ERUPT ALONG THE INSTABILITY AXIS ALONG INTERSTATE 25.
TONIGHT...THE FLOW ALOFT BACKS EVEN MORE TO SOUTH SOUTHWEST WITH
MOIST UPSLOPE SOUTHEAST WINDS CONTINUING. BOUNDARY LAYER PROGS
SUGGEST AREAS OF FOG WILL BE RELATIVELY WIDESPREAD ALONG AND EAST OF
INTERSTATE 25. LARGE SCALE SUBSIDENCE WILL LIMIT SHOWER COVERAGE...
THOUGH CANNOT RULE OUT SCATTERED SHOWERS NORTH OF A RAWLINS TO
SCOTTSBLUFF LINE CLOSER TO DEEPER MOISTURE WITH PRECIPITATION AIDED
BY UPSLOPE LIFT.
SATURDAY...STRONG NEGATIVELY TILTED SHORTWAVE ROTATES NORTHEASTWARD
ACROSS WYOMING AND COLORADO IN THE AFTERNOON INDUCING SURFACE LOW
STRENGTHENING ACROSS FAR SOUTHEAST WYOMING IN THE AFTERNOON. A WARM
FRONT WILL EXTEND EASTWARD FROM THE SURFACE LOW ACROSS WESTERN
NEBRASKA. A WELL PRONOUNCED LOW AND MID LEVEL THETA-E RIDGE AXIS
WILL DEVELOP IN THE AFTERNOON FROM DOUGLAS TO SCOTTSBLUFF. IF WARM
MID LEVEL TEMPERATURES...AND THE ASSOCIATED CONVECTIVE INHIBITION
CAN BE ELIMINATED...AND ENOUGH SURFACE HEATING OCCURS NORTH OF THE
WARM FRONT TO DIMINISH LOW CLOUDS...ISOLATED SEVERE THUNDERSTORMS
MAY ERUPT NORTH OF THE WARM FRONT IN THE AFTERNOON ROUGHLY NORTH OF
A CASPER TO SIDNEY LINE...WHERE SHEAR AND INSTABILITY PARAMETERS
WILL BE MAXIMIZED. WITH PROGGED 0 TO 3 KM HELICITY VALUES EXCEEDING
200...A FEW ROTATING STORMS WILL BE POSSIBLE NORTH OF A CASPER TO
SIDNEY LINE...WITH ISOLATED STRONG THUNDERSTORMS ELSEWHERE. DRY SLOT
AND DRY PUNCH WILL ENHANCE THUNDERSTORM DEVELOPMENT NORTH OF THE
WARM FRONT SHOULD THE CAPE BE REALIZED. WARMER MOS HIGH TEMPERATURES
PREFERRED PER 700 MB TEMPERATURE PROGS.
LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
MODELS IN FAIRLY GOOD AGREEMENT SATURDAY EVENING ON A SURFACE LOW
PRESSURE SYSTEM MOVING NORTHEAST OUT OF EASTERN COLORADO. 700MB
WINDS BEHIND THE LOW FORECAST AROUND 65KTS AS THIS LOW TRACKS
NORTH. AT THE VERY LEAST...I THINK OUR WIND PRONE AREAS ARE GOING
TO SEE WARNING LEVEL WINDS AND WENT AHEAD WITH A WATCH FOR THOSE
AREAS. PRECIP HERE IN SOUTHEAST WYOMING SHOULD COME TO AN END FROM
SOUTH TO NORTH SATURDAY NIGHT. THE EXCEPTION BEING OUT NEAR THE
SNOWY AND SIERRA MADRE RANGES WHERE BOTH THE GFS AND ECMWF KEEPS
SOME WRAP AROUND MOISTURE IN UPSLOPING CONDITIONS OUT THAT WAY.
TEMPERATURES ARE GOING TO BE SLOW TO INCREASE AS GFS KEEPS 700MB
TEMPERATURES AROUND +5C THROUGH TUESDAY. BIG WARM UP STARTS
WEDNESDAY WHEN 700MB TEMPERATURES CLIMB TO +12C. THAT WILL BE
SHORT LIVED HOWEVER...AS A SHORTWAVE TRACKS SOUTH INTO
SOUTHEASTERN WYOMING...KNOCKING 700MB TEMPERATURES BACK DOWN IN
THE SINGLE DIGITS WEDNESDAY NIGHT. UPSLOPING FLOW RETURNS THURSDAY
AS A SURFACE HIGH PARKS ITSELF OVER WEST CENTRAL NEBRASKA.
&&
FIRE WEATHER...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY AND WILL PERSIST
INTO SATURDAY. STRONG LOW PRESSURE SYSTEM IS THEN SET TO MOVE
NORTH OUT OF EASTERN COLORADO...BRINGING STRONG WINDS TO THE AREA.
FORTUNATELY...IT LOOKS LIKE AFTERNOON MIN HUMIDITIES WILL STAY
ABOVE CRITICAL THRESHOLDS...KEEPING FIRE WEATHER CONDITIONS IN
CHECK FOR THE MOST PART.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WATCH FROM 6 PM SATURDAY TO 9 AM SUNDAY FOR WYZ106-
WYZ110-WYZ116-WYZ117.
DENSE FOG ADVISORY UNTIL NOON FOR WYZ116-WYZ117.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...RUBIN
LONG TERM/AVIATION...CLAYCOMB
UPDATE...WEILAND