Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/13/12
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
347 PM MDT THU OCT 11 2012
.SHORT TERM... FRONT PASSED ACROSS PLAINS DURING THE MORNING HOURS
WITH NORTHEAST WINDS PERSISTING THOUGH SLOWING DECREASING. HIGH
LEVEL MOISTURE IN PLACE OVER AREA WITH SOME CUMULUS ACROSS MOUNTAINS
ABOVE WEAK INVERSION. RADAR SHOWING SOME WEAK ECHOES OVER ZONE 34
WHERE LAPS SURFACE ANALYSIS INDICATING SOME CAPE. LATEST RUC KEEPS
SOME CAPE IN THIS AREA DURING THE EVENING...AND WILL CONTINUE WITH A
SLIGHT CHANCE OF THUNDERSTORMS THERE. OTHERWISE...SHOULD CONTINUE TO
SEE AN INCREASE IN MID AND HIGH LEVEL MOISTURE TONIGHT AS UPPER LOW
MOVES INTO THE DESERT SOUTHWEST. MODEL CROSS SECTIONS SHOW A GRADUAL
LOWERING OF THE MOISTURE AFTER MIDNIGHT ALONG WITH SOME INCREASE IN
MID LEVEL QG ASCENT. SOME SHOWERS POSSIBLE ACROSS THE MOUNTAINS
OVERNIGHT. AIRMASS STILL FAIRLY WARM SO SNOW LEVEL WILL BE RATHER
HIGH WITH NO ACCUMULATION. ACROSS PLAINS...WINDS TO BECOME SOUTHEAST
AND WEAKEN DURING THE EVENING WITH ONLY A SLIGHT INCREASE IN LOW
LEVEL MOISTURE AFTER MIDNIGHT. WITH THE LIGHT WINDS AND COOLER
AIRMASS...DECIDED TO KEEP THE MENTION OF PATCHY FOG ACROSS THE
NORTHERN SECTIONS OF THE URBAN CORRIDOR. ON FRIDAY...MODES SHOW
UPPER LOW MOVING INTO SOUTHERN ARIZONA BY 18Z AND OVER SOUTHEAST
UTAH LATE IN THE AFTERNOON. SOUTHWEST FLOW ALOFT TO BECOME SOUTHERLY
WHICH WILL BRING MORE MOISTURE ACROSS THE AREA. THOUGH FLOW NOT
FAVORABLE FOR GOOD MOUNTAIN OROGRAPHICS...DECENT MOISTURE ALONG WITH
INCREASING QG VERTICAL MOTION AND INSTABILITY SUFFICIENT SHOULD BE
SUFFICIENT TO GENERATE NUMEROUS SHOWERS ALONG WITH SOME
THUNDERSTORMS ACROSS THE MOUNTAINS DURING THE AFTERNOON. AIRMASS
STILL FAIRLY WARM THROUGH THE AFTERNOON AND DESPITE THE POTENTIAL
FOR SOME EVAPORATIVE COOLING...SNOW LEVEL SHOULD REMAIN FAIRLY HIGH.
ANY ACCUMULATION TO BE CONFINED TO ELEVATIONS ABOVE 12000 FEET. AS
FOR PLAINS...SURFACE WINDS TO BECOME SOUTHEAST BY THE AFTERNOON WITH
THE POSSIBLE DEVELOPMENT OF A DENVER CYCLONE. THE SOUTHERLY FLOW
WILL ADVECT LOW LEVEL MOISTURE NORTHWARD. MODELS GENERATE CAPES OF
AROUND 300 J/KG ACROSS PALMER DIVIDE DURING THE AFTERNOON...LESS
FURTHER NORTH. SO BEST CHANCE OF STORMS TO BE ALONG PALMER DIVIDE
NORTHEAST INTO SOUTHERN WASHINGTON COUNTY. GUIDANCE TEMPERATURES
FAIRLY CLOSE ACROSS THE AREA THOUGH COULD BE A BIT TOO WARM BASED ON
POTENTIAL CLOUD COVER.
.LONG TERM...THE UPPER CLOSED LOW IS OVER THE NORTHEAST CORNER OF
COLORADO AT 12Z SATURDAY. THE UPPER TROUGH AXIS GETS EAST OF THE
CWA BY EARLY SATURDAY AFTERNOON. NORTHWESTERLY FLOW ALOFT WILL
DOMINATE AFTER TROUGH PASSAGE THROUGH SUNDAY NIGHT. THERE IS PRETTY
DECENT UPWARD SYNOPTIC SCALE ENERGY PROGGED ON THE QG VERTICAL
VELOCITY FIELDS FRIDAY NIGHT INTO SATURDAY MORNING. BY 18Z...PRETTY
STRONG DOWNWARD MOTION IS EXPECTED. BY 06Z SATURDAY NIGHT THROUGH
SUNDAY NIGHT...THERE IS BENIGN ENERGY IN THE SYNOPTIC SCALE. THE
BOUNDARY LAYER FLOW IS PROGGED TO BE DOWNSLOPING AS THE TROUGH
PASSES SATURDAY MORNING. THERE IS A BRIEF SHOT OF FAIRLY STRONG
NORTHWESTERLIES SATURDAY MORNING. THE DOWNSLOPING RELAXES BY
SATURDAY EVENING...WITH NORMAL DIURNAL PATTERNS EXPECTED THE REST OF
THE NIGHT THROUGH SUNDAY NIGHT. FOR MOISTURE...IT IS DEEP OVER THE
MOUNTAINS FRIDAY NIGHT THROUGH SATURDAY. EVEN SATURDAY NIGHT IT IS
PRETTY GOOD...BUT DECREASES SUNDAY MORNING. FOR THE PLAINS...
MOISTURE IS ONLY FAIR FRIDAY NIGHT...THAT AREA IS IN THE DRY SLOT OF
THE MID LATITUDE CYCLONE. MOISTURE GETS BETTER ON SATURDAY ON THE
BACKSIDE OF THE CLOSED LOW...AND IT LINGERS AROUND SATURDAY EVEN
OVER THE EASTERN HALF OF THE PLAINS. ON SUNDAY...MOISTURE DECREASES
OVER ALL THE CWA...SUNDAY NIGHT TOO. PRECIPITABLE WATER VALUES ARE
IN THE 0.40 TO 0.60 INCH RANGE LATER FRIDAY NIGHT AND SATURDAY
...THEN THEY DECREASE ON SUNDAY. THERE IS SOME CAPE OVER THE
EASTERN HALF OF THE PLAINS FRIDAY EVENING...VALUES ARE UP TO 500
J/KG. THAT IS IT FOR CAPE...THERE IS NONE SATURDAY OR SUNDAY FOR
THE CWA. FOR MOUNTAIN POPS...PRECIPITATION IS A VERY GOOD BET
FRIDAY NIGHT INTO SATURDAY EVENING...INITIALLY WITH THE SYNOPTIC
SCALE ENERGY OF THE CLOSED LOW...THEN WITH ORTHOGRAPHIC ENHANCEMENT
BY SATURDAY AFTERNOON. SO WILL GO WITH 60-80%S FRIDAY NIGHT INTO
SATURDAY EVENING. THEN DECREASE THEM DOWN TO NOTHING BY SUNDAY
MORNING SOMETIME. FOR THE PLAINS...THE FRONT RANGE AREA WILL HAVE
DRY SLOTTING...THEN PRETTY DECENT DRYING FROM DOWNSLOPING...SO POPS
WILL BE MINIMAL. BETTER POPS ARE EXPECTED FURTHER EAST...BUT NO
"LIKELY"S. WILL KEEP POPS GOING OVER THE FAR EAST INTO SATURDAY
NIGHT. SUNDAY AND SUNDAY NIGHT ARE DRY. WILL NOT GO WITH ANY
HIGHLIGHTS RIGHT NOW. NOT SURE IF THERE WILL BE ENOUGH MOISTURE FOR
ADVISORY AMOUNTS. FOR TEMPERATURES...SATURDAY`S HIGHS ARE SIMILAR
TO FRIDAY`S. SUNDAY`S HIGHS ARE 1-3 C WARMER THAN SATURDAY`S. FOR
THE LATER DAYS...MONDAY THROUGH THURSDAY...NORTHWESTERLY FLOW ALOFT
WILL CONTINUE OVER THE CWA ALL FOUR DAYS. FROM 12Z TUESDAY THROUGH
WEDNESDAY AFTERNOON...THE FLOW ALOFT IS WELL OVER 100 KNOTS. A COLD
FRONT IS PROGGED TO MOVE IN TUESDAY NIGHT AS WELL. MOISTURE IS VERY
SPARSE.
&&
.AVIATION...NORTHEAST SURFACE WINDS TO WEAKEN AND SHIFT TO THE
SOUTHEAST DURING THE EVENING TRANSITIONING TO DRAINAGE FLOW
OVERNIGHT. SLIGHT CHANCE FOR SOME PATCHY FOG DEVELOPING IN THE
15Z-18Z TIME FRAME NORTH OF THE DENVER AREA...SHOULD NOT AFFECT AREA
AIRPORTS. WINDS TO SHIFT TO THE SOUTHEAST BY 18Z FRIDAY WITH THE
POTENTIAL FOR THE DEVELOPMENT OF A DENVER CYCLONE ACROSS SOUTHERN
WELD COUNTY. THUS WINDS COULD BE NORTHWEST AT KBJC AND SOUTHERLY AT
KDEN AND KAPA. HIGH LEVEL MOISTURE WILL INCREASE OVERNIGHT ALONG
WITH SOME MID LEVEL MOISTURE. BY 18Z FRIDAY...LOW LEVEL MOISTURE TO
SPREAD ACROSS PLAINS WITH A SLIGHT CHANCE FOR RAIN SHOWERS. VFR
CONDITIONS TO PREVAIL...WITH POTENTIAL FOR CEILINGS AROUND 6000 FEET
AGL.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D_L
LONG TERM....RJK
AVIATION...D_L
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
924 AM MDT THU OCT 11 2012
.UPDATE...FRONT SEEMS TO BE ACROSS NORTHERN FRINGES OF ADAMS
COUNTY...BASED ON SURFACE OBSERVATIONS AND LAPS SURFACE ANALYSIS.
FRONT TO CONTINUE TO MOVE ACROSS REMAINDER OF PLAINS DURING THE
MORNING HOURS WITH WINDS BECOMING MORE EASTERLY BY THE AFTERNOON.
AIRMASS TO BE SLIGHTLY COOLER ACROSS PLAINS BEHIND FRONT...WITH
THE COOLER AIR OVER NORTHEAST CORNER. OTHERWISE...ONLY A SLIGHT
CHANCE FOR SHOWERS OVER THE MOUNTAINS LATER THIS AFTERNOON AS
LATEST RUC INDICATE MODEST INSTABILITY AND SOME CAPE.
OVERALL...CURRENT FORECAST LOOK ON TRACK...THOUGH MAY NEED TO
ADJUST WIND AND TEMP GRIDS ACROSS PLAINS GIVEN CURRENT
CONDITIONS.
&&
.SHORT TERM...
.AVIATION...FRONT APPEARS TO BE MOVING ACROSS THE NORTHERN
SECTIONS OF ADAMS COUNTY...THOUGH NOT QUITE INTO THE DIA AREA.
FRONT SHOULD BE MOVING ACROSS DIA WITHIN THE NEXT HALF HOUR.
CURRENT TAF TRENDS STILL LOOKING GOOD...BUT DID DELAY THE ONSET OF
THE GUSTS AN HOUR BASED ON UPSTREAM OBSERVATIONS. MAY ALSO NEED TO
ADJUST WINDS AT KBJC.
&&
.PREV DISCUSSION... /ISSUED 304 AM MDT THU OCT 11 2012/
SHORT TERM...SCATTERED HIGH WAVE CLOUDS STILL MOVING ACROSS THE
FORECAST AREA AS HIGH LEVEL MOISTURE IS STREAMING OVERHEAD THROUGH
THE RIDGE ALOFT. THE RIDGE AXIS IS PROGGED TO MOVE FROM
SOUTHWESTERN CO TO THE NORTHEAST CORNER OF THE STATE BY TONIGHT AS
A CUTOFF LOW MOVES INTO THE SOUTHERN GREAT BASIN. FORECASTED
SYNTHETIC SATELLITE IMAGES SHOW THE HIGH WAVE CLOUDS DECREASING
EARLY THIS MORNING...THEN REFORMING MID-MORNING AND INTO THE
AFTERNOON. HAVE ADDED THIS TO THE GRIDS AS HINTS OF IT ARE ALREADY
FORMING OVER SOUTHERN COLORADO.
A COLD FRONT CURRENTLY OVER NORTHERN NEBRASKA SHOULD CONTINUE TO
MOVE SOUTH AND INTO COLORADO JUST AROUND SUNRISE. THE POST FRONTAL
AIRMASS WILL BE MUCH COOLER...THOUGH NO MOISTURE WITH IT SO NO
POPS ARE MENTIONED. HAVE TRENDED MAX TEMPERATURES DOWN A FEW
DEGREES OVER THE PLAINS FOR TODAY WITH THE ANTICIPATED HIGH CLOUDS
AROUND FOR TODAY AS WELL AS THE COLD FRONT AFFECTING THE
NORTHEAST AND EASTERN PLAINS. THE DEPTH OF THE COLD FRONT LOOKS TO
REACH UP TO 9000 FEET OR LESS...KEEPING THE HIGHER TERRAIN OUT OF
THE STABLE AIRMASS. A SMALL AMOUNT OF INSTABILITY AND A SLIGHT
INCREASE IN MOISTURE WILL ALLOW FOR A SLIGHT CHANCE OF SHOWERS AND
A THUNDERSTORM OR TWO OVER THE HIGH MOUNTAINS THIS AFTERNOON.
TONIGHT WILL SEE AN INCREASE IN CLOUDS FROM THE SOUTH AS THE LOW
MOVES CLOSER. A FEW SHOWERS WILL BE POSSIBLE OVER THE MOUNTAINS
SOUTH OF I70 AFTER MIDNIGHT. NO ACCUMULATIONS ARE EXPECTED.
TEMPERATURES OVER THE PLAINS WILL BE COOLER THAN LAST NIGHT WITH A
SMALL CHANCE FOR PATCHY FOG OVER THE NORTHERN URBAN CORRIDOR.
LONG TERM...ATTENTION CONTINUES TO FOCUS ON UPPER LEVEL LOW
WHICH WILL MOVE ACROSS THE DESERT SOUTHWEST AND APPROACH SOUTHERN
UTAH BY FRIDAY EVENING AND THEN ACROSS WESTERN COLORADO FRIDAY
NIGHT. Q-G VERTICAL MOTION INCREASES AHEAD OF THIS FEATURE...AS
WELL AS MID AND UPPER LEVEL MOISTURE. AT THE SAME TIME...LOW LEVEL
MOISTURE IS ALSO PROGGED TO GET DRAWN INTO THIS SYSTEM FROM TEXAS
AS SOUTHERLY SURFACE WINDS INCREASE ACROSS THE HIGH PLAINS. THE
RESULT WILL BE AN INCREASINGLY MOIST AND UNSTABLE AIRMASS WITH A
COUPLE HUNDRED JOULES OF CAPE AVAILABLE BY AFTERNOON. WITH THE
LARGE SCALE Q-G VERTICAL MOTION ADVERTISED...WE SHOULD BE ABLE TO
GENERATE NUMEROUS SHOWERS OVER THE MOUNTAINS AND A FEW
THUNDERSTORMS AS WELL. AIRMASS IS INITIALLY VERY WARM SO ANY SNOW
ACCUMULATION TOMORROW SHOULD BE CONFINED TO ELEVATIONS ABOVE 11-12
THOUSAND FEET. ON THE PLAINS...SHOWER/STORM COVERAGE WILL BE MORE
LIMITED GIVEN SOUTHWEST FLOW ALOFT AND DOWNSLOPING COMPONENT ABOVE
THE BOUNDARY LAYER. NONETHELESS...WE SHOULD STILL SEE CONVECTIVE
ACTIVITY WITH LIFT AND CAPE PRESENT. BEST CHANCE WOULD BE OVER THE
SOUTHERN AND EASTERN PORTIONS OF THE CWA LATE IN THE DAY WHERE
BEST THETA-E ADVECTION OCCURS...WHILE ONE CANT RULE OUT SURFACE
BASED CONVECTIVE INITIATION ALONG A DENVER CONVERGENCE ZONE.
BY FRIDAY NIGHT...STRONG MID LEVEL COLD ADVECTION OCCURS WITH
UPPER TROUGH ADVANCEMENT AND COLD POOL PASSING OVERHEAD.
HOWEVER...WE WILL LIKELY SEE MID LEVEL DRYING WITH GOOD POTENTIAL
OF DRY SLOT PASSING OVER MOST OF THE CWA. AS A RESULT...LOOKS LIKE
BEST CHANCE OF SHOWERS/STORMS WOULD BE EARLY IN THE EVENING WITH
DRYING THEREAFTER. IN THE MOUNTAINS...TEMPERATURES WILL BE COLD
ENOUGH FOR MOSTLY SNOW AND THERE IS A THREAT OF MORE SIGNIFICANT
SNOWFALL DEVELOPING ON THE BACK EDGE DEFORMATION ZONE OF UPPER
TROUGH. AT THIS TIME...BEST LIFT AND TROWAL WOULD PASS OFF TO OUR
NORTH AND WEST AND WE WOULD HAVE TO WAIT UNTIL LATE FRIDAY
NIGHT/SATURDAY MORNING TO GET A STEADY AND HEAVIER SNOW INTO THE
MOUNTAINS AS NORTHWEST FLOW DEVELOPS. ZONE 31 WOULD HAVE BEST SHOT
OF RECEIVING HEAVIER SNOWFALL BUT EVEN THERE BEGINNING OF SNOW
WOULD BE LATE 4TH PERIOD SO NO WATCHES YET. ZONE 33 AND 34 COULD
SEE TOO MUCH DRY SLOT INTERACTION LIMITING ACCUMULATIONS...BUT
THAT ALL DEPENDS ON EXACT STORM PATH. SPEAKING OF WHICH...IT WAS
INTERESTING TO SEE ALMOST ALL 00Z MODELS INCLUDING THE
ECWMF...CANADIAN...AND GFS ENSEMBLES BECOME MORE ELONGATED WITH
THE UPPER TROUGH AS IT PASSES OVER EASTERN COLORADO.
IF THE TROUGH DOES BECOME ELONGATED...THE FORECAST FOR SATURDAY ON
THE PLAINS BECOMES UNCERTAIN AS A MORE NORTHERLY FLOW COULD
RESULT IN LESS DOWNSLOPE AND A CHANCE OF SHOWERS. MEANWHILE...
THREAT OF STRONGEST WINDS WITH GUSTS TO 40 MPH PLUS WOULD SHIFT
FROM THE FAVORED DOWNSLOPE AREAS IN/NEAR THE FOOTHILLS TO THE
EASTERN PLAINS. AT THIS TIME...WE WILL KEEP THE GUSTY WINDS IN THE
FORECAST BUT ALSO INTRODUCE JUST A SLIGHT CHANCE OF SHOWERS IN
CASE THE 00Z MODELS ARE CORRECT. BY SATURDAY NIGHT...MOUNTAIN SNOW
SHOWERS WILL GRADUALLY DECREASE WITH CLEARING SKIES AND
DIMINISHING WINDS ELSEWHERE.
SUNDAY THROUGH THURSDAY LOOKS MAINLY DRY AND WARMER. THERE ARE
STILL A FEW MODELS RUNS POINTING TO A LOW PRECIP THREAT IN THE
MOUNTAINS TUESDAY AND SLIGHT COOLING/GUSTY WINDS. OTHERWISE DRY
WEATHER EXPECTED WITH TEMPERATURES A FEW DEGREES ABOVE NORMAL.
AVIATION...DRAINAGE FLOW EARLY THIS MORNING IS EXPECTED TO SHIFT
TO THE NW AHEAD OF A SURFACE FRONT. THE FRONT SHOULD PASS ACROSS
THE AREA BETWEEN 15Z AND 18Z...WITH SPEEDS 10-15 KTS. AFTER 18Z
WINDS TO BECOME EASTERLY WITH SPEEDS AROUND 10 KTS TRANSITIONING
TO DRAINAGE AGAIN TONIGHT. VFR CONDITIONS EXPECTED THROUGH TONIGHT
AND INTO TOMORROW MORNING. HIGH LEVEL MOISTURE TO DECREASE EARLY
THIS MORNING BEFORE INCREASING AGAIN LATE MORNING. A CHANCE FOR
RAIN SHOWERS WILL OCCUR FRIDAY AFTERNOON.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....BARJENBRUCH
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS ALBANY NY
135 AM EDT THU OCT 11 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS EASTERN NEW YORK AND
WESTERN NEW ENGLAND THIS EVENING WITH SOME SCATTERED SHOWERS
PERSISTING NORTHWEST OF THE CAPITAL REGION. HIGH PRESSURE WILL
BRIEFLY BUILD IN FROM THE OHIO VALLEY WITH COOL AND BRISK CONDITIONS
TOMORROW. ANOTHER COLD FRONT WILL APPROACH FROM THE EASTERN GREAT
LAKES REGION THURSDAY NIGHT WITH A CHANCE OF SHOWERS ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AT 1:30 AM EDT...LAKE EFFECT SHOWERS NOW OVER MUCH OF THE ADIRONDACK
PARK...SOME OF WHICH HAVE WORKED NORTH OF GLENS FALLS INTO EVEN
NORTHERN WASHINGTON COUNTY. MOST IF NOT ALL PLACES WERE STILL ABOVE
FREEZING WITH MADIS INDICATING 37 DEGREES AT LONG LAKE. SOME OF THE
HIGHER ELEVATIONS PROBABLY SEEING SOME MIXING WITH WET SNOW FLAKES
OR GRAUPEL AT THIS TIME.
FINE TUNED THE PLUME IN OUR GRIDS BASED ON THE LATEST GUIDANCE AND
RADAR TRENDS. THE HRRR ACTUALLY BRINGS THE PLUME RIGHT INTO THE
CAPITAL DISTRICT BRIEFLY LATER OVERNIGHT. NOT SOLD ON THIS SOLUTION
SO WILL USE PERSISTENCE AT THIS TIME FRAME.
THE KVIE PROGRAM INDICATED THAT THE INLAND EXTENT NEVER EXCEEDS
ABOUT 75 MILES WHICH MEANS THE PLUME WOULD FALL SHORT OF THE CAPITAL
DISTRICT. AGAIN...FOR NOW WILL LEAVE IT OUT.
IT SHOULD BE COLD ENOUGH FOR ALL SNOW SHOWERS ACROSS THE ADIRONDACKS
BUT AT THIS TIME...WE BELIEVE ANY ACCUMULATIONS WOULD BE CONFINED TO
THE HIGHEST MOUNTAIN AREAS AND WE DID NOT INCLUDE ANY IN THE
GRIDS.
OVERNIGHT LOWS LOOK FINE FROM BEFORE AND WERE GENERALLY LEFT
ALONE.
A CHANNEL OF VERY COLD AIR WILL BE DIVING IN FROM THE NORTHWEST WITH
THE UPPER TROUGH SHOWING SIGNS OF BECOMING NEGATIVELY TILTED...AS
THE CLOSED EMBEDDED H500 CIRCULATION IN THE TROUGH MOVES OVER HUDSON
BAY. THE H500 TEMPS ARE CLOSE TO -30C OVER MI AND WI FROM THE 1200
UTC RAOB DATA. THIS CHILLY AIR ALOFT COUPLED WITH THE WARM LAKE
ONTARIO TEMPS IN THE 10-13C RANGE /FAVORABLE DELTA TEMPS FROM THE
SFC TO H700/ WILL KICK UP SOME LAKE EFFECT SHOWERS...WHICH WILL
LIKELY TRANSITION TO SOME SNOW SHOWERS OVER THE WRN DACKS. THE
BOUNDARY LAYER WILL TAKE ITS TIME TO COOL DOWN. THE LOW LEVEL WINDS
WILL CONTINUE TO VEER CLOSE TO A 270-280 DEG LOW-LEVEL TRAJECTORY.
THERE COULD BE A FEW RUMBLES OF THUNDER CLOSER TO LAKE SHORE...WHERE
BETTER LAKE INDUCED INSTABILITY IS OCCURRING. AGAIN..ANY SNOW
ACCUMULATIONS WILL BE VERY LIGHT ON THE ORDER OF A COATING TO A FEW
TENTHS OVER SOME ISOLD PORTIONS OF NRN HERKIMER AND NRN HAMILTON
COUNTIES...MAINLY OVER THE HIGHEST ELEVATIONS.
ELSEWHERE...PARTLY TO MOSTLY CLOUDY CONDITIONS WILL PERSIST AFTER
MIDNIGHT WITH BRISK CONDITIONS. THE COLD ADVECTION IN THE WAKE OF
THE BOUNDARY WILL ALLOW TEMPS TO FALL INTO THE 0 TO -5C RANGE
ACROSS THE FCST AREA. LOW TEMPS WILL GENERALLY BE IN THE U30S TO
L40S...EXCEPT FOR SOME LOWER TO M30S OVER THE SRN DACKS
REGION...AND SRN GREENS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
TOMORROW...THE LOW-LEVEL FLOW CONTINUES TO VEER TO MORE OF A W/NW
DIRECTION WITH SOME LAKE EFFECT RAIN SHOWERS CONTINUING OVER THE
WRN DACKS...W-CNTRL MOHAWK VALLEY...NRN CATSKILLS...AND SCHOHARIE
VALLEY. SFC HIGH PRESSURE WILL BE NUDGING IN FROM THE OHIO VALLEY.
IT WILL BE A BRISK AND COOL AFTERNOON WITH W/NW WINDS OF 10 TO 20
MPH WITH SOME GUSTS AROUND 30 MPH. THE BRISK CONDITIONS WILL BE
DUE TO GOOD MIXING...AND A STRONG SFC PRESSURE GRADIENT BETWEEN
THE SFC ANTICYCLONE TO THE SOUTH...AND LOW PRESSURE OVER THE
CANADIAN MARITIMES. MAX TEMPS WILL GENERALLY BE IN THE 50S /A FEW
ISOLD 60S TO THE SOUTH/ WITH SOME U40S OVER THE SRN GREENS...SRN
DACKS...AND ERN CATSKILLS.
THU NIGHT...THE VESTIGES OF THE LAKE EFFECT LIFT NORTHWARD ACROSS
THE DACKS...AS THE LOW TO MID LEVEL FLOW BACKS...AND BECOMES
ZONAL. SOME WARM ADVECTION RAIN OR EVEN LIGHT SNOW SHOWERS MAY
OCCUR OVER THE SRN DACKS AGAIN. CLOUDS WILL THICKEN AND LOWER OVER
THE REGION...AS THE NEXT SHORT-WAVE APPROACHES FROM ONTARIO AND
THE GREAT LAKES REGION. THE SFC COLD FRONT WITH THE SHORT-WAVE
TROUGH IS FASTER THIS SUITE OF SHORT-RANGE GUIDANCE...WITH A GOOD
CHANCE OF SHOWERS FROM THE I-90 CORRIDOR NORTH PRIOR TO 12Z/FRI.
LOWS WILL GENERALLY BE IN THE U30S TO L40S AGAIN...EXCEPT
NORTHWEST OF THE CAPITAL REGION WHERE SOME LOWER TO M30S WILL BE
POSSIBLE. TEMPS MAY ACTUALLY FALL EARLY AND RISE OVERNIGHT.
FRIDAY...THE COLD FRONT BLASTS THROUGH WITH SOME SCATTERED SHOWERS
MOVING ACROSS THE REGION. THE MOISTURE CONVERGENCE ISN/T TOO
IMPRESSIVE WITH THE FASTER TIMING OF THE BOUNDARY. THE THERMAL
GRADIENT IS IMPRESSIVE WITH H850 TEMPS FALLING TO -4C TO -8C FROM
SOUTH TO NORTH OVER THE REGION IN THE STRONG COLD AIR ADVECTION
REGIME. THE WINDS WILL INCREASE DURING THE AFTERNOON...AND THERE
COULD BE SOME UPSLOPE OR LAKE EFFECT RAIN/SNOW SHOWERS
BRIEFLY...BEFORE THE LOW LEVEL FLOW VEERS QUICKLY TO THE N/NW. MAX
TEMPS WILL BE TRICKY WITH HIGHS GENERALLY IN THE 50S IN THE
VALLEYS...AND LOWER 40S TO POSSIBLY 50F OVER THE HILLS AND MTNS.
FRI NIGHT...A COLD CANADIAN ANTICYCLONE BUILDS IN RAPIDLY OVER THE
NORTHEAST WITH CLEAR/MOSTLY CLEAR SKIES...AND LIGHT TO CALM WINDS.
IDEAL RADIATIONAL COOLING IS EXPECTED...AS TEMPS ARE EXPECTED TO
FALL BELOW 32F ACROSS THE ENTIRE FCST AREA. A WIDESPREAD FROST IS
ANTICIPATED AT THIS TIME. THERE COULD EVEN BE SOME TEENS OVER THE
SRN DACKS. MID AND U20S WILL BE COMMON IN MOST LOCATIONS. WE
CONTINUED THE MENTION OF A WIDESPREAD FREEZE IN THE HWO.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
A CUT OFF LOW OVER THE SOUTHWESTERN UNITED STATES IS EXPECTED TO
OPEN AND MOVE NORTHEASTWARD. IT WILL WEAKEN AS HEADS INTO THE GREAT
LAKES REGION OVER THE WEEKEND. TO START OFF THE WEEKEND WILL HAVE
SURFACE RIDGING OVER THE REGION WHICH WILL SHIFT EASTWARD AND
OFFSHORE BY SATURDAY EVENING. ALOFT WILL HAVE SOME RIDGING BEING
INDUCED AHEAD OF APPROACHING LOW PRESSURE SYSTEM. AT THIS TIME
EXPECTING DRY WEATHER ON SATURDAY WITH CHANCES FOR SHOWERS
INCREASING SATURDAY NIGHT ESPECIALLY LATE AS THE LOW PRESSURE SYSTEM
APPROACHES. THIS SYSTEM IS EXPECTED TO IMPACT THE REGION INTO
MONDAY. MODEL GUIDANCE IS IN AGREEMENT THAT THE SURFACE LOW WILL
PASS TO OUR NORTH AND WEST AND BRING MULTIPLE BOUNDARIES INTO AND
THROUGH THE REGION.
THERE IS GOOD AGREEMENT THAT THE THE LONGWAVE PATTERN WILL
TRANSITION INTO A FAST ZONAL FLOW EARLY NEXT WEEK. WITH THIS
COMES UNCERTAINTY IN TIMING OF INDIVIDUAL FEATURES. AT THIS TIME
EXPECT TUESDAY AND POSSIBLY WEDNESDAY TO BE DRY AS HIGH PRESSURE
MOVES ACROSS THE REGION.
AFTER A COLD START ON SATURDAY...THEN SEASONABLE TEMPERATURES ARE
EXPECTED.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
LAKE EFFECT ACTIVITY CONTINUES DOWNWIND OF LAKE ONTARIO AND THIS
WILL CONTINUE THROUGH THE REMAINDER OF THE OVERNIGHT HOURS. THE
BAND IS EXPECTED TO LIFT NORTHWARD DURING THE MORNING HOURS. IN THE
MEANTIME...SOME OF THESE LAKE CLOUDS WILL IMPACT THE KGFL-KALB-KPSF
SITES WITH EXPECTATIONS THAT CIGS WOULD REMAIN ABOVE OR JUST TOUCH
THE MVFR THRESHOLDS. HOWEVER...NO RESTRICTIONS TO VIS ARE EXPECTED
AT THIS TIME. THEREAFTER...VFR CONDITIONS SHOULD PREVAIL FOR THE
REMAINDER OF THE TAF FORECAST CYCLE.
WESTERLY WINDS WILL CONTINUE OVERNIGHT AND INCREASE THROUGH THURSDAY
AS THE COMBINATION OF INCREASING MIXING LAYER HEIGHTS AND STILL A
TIGHT SURFACE PRESSURE GRADIENT HOLDS ACROSS THE REGION. GUSTS AT
OR ABOVE THE 20KT THRESHOLD IS EXPECTED. THOSE VALUES WILL GREATLY
DIMINISH WITHIN AN HOUR OR TWO OF SUNSET.
OUTLOOK...
THU OVRNT. VFR/MVFR. CHC -SHRA.
FRI...VFR. CHC -SHRA IN THE AM.
FRI PM-SAT...VFR. NO SIG WX.
SAT NT-MON...VFR/MVFR CHC -SHRA.
&&
.FIRE WEATHER...
A COLD FRONT WILL MOVE ACROSS EASTERN NEW YORK AND
WESTERN NEW ENGLAND THIS EVENING WITH SOME SCATTERED SHOWERS
PERSISTING NORTHWEST OF THE CAPITAL REGION. A FEW SNOW SHOWERS MAY
OCCUR OVER THE SOUTHERN ADIRONDACKS. HIGH PRESSURE WILL BRIEFLY
BUILD IN FROM THE OHIO VALLEY WITH COOL AND BRISK CONDITIONS
TOMORROW. THE WINDS WILL BE FROM THE WEST OR NORTHWEST AT 10 TO 20
MPH...WITH SOME GUSTS TO AROUND 30 MPH.
SCATTERED LIGHT SHOWERS ARE EXPECTED THURSDAY NIGHT INTO FRIDAY
MORNING WITH ANOTHER COLD FRONT. SOME VERY LIGHT SNOW
ACCUMULATIONS ARE POSSIBLE IN THE SOUTHERN ADIRONDACK REGION. THE
WINDS WILL INCREASE FROM THE NORTHWEST AT 10 TO 20 MPH WITH SOME
GUSTS CLOSE TO 30 MPH FRIDAY AFTERNOON...AND THE WINDS WILL BECOME
LIGHT TO CALM FRIDAY NIGHT. A WIDESPREAD FREEZE WILL BE POSSIBLE
SATURDAY MORNING.
&&
.HYDROLOGY...
NO HYDRO RELATED PROBLEMS ARE EXPECTED THROUGH THE NEXT 5 DAYS.
THE PRECIPITATION WITH THE COLD FRONTAL PASSAGE TONIGHT WILL AMOUNT
TO A FEW HUNDREDTHS TO A FEW TENTHS OF AN INCH.
ANOTHER COLD FRONT MAY FOCUS ANOTHER ROUND OF LIGHT SHOWERS THURSDAY
NIGHT INTO FRIDAY...SOME OF WHICH COULD FALL AS SNOW SHOWERS
ACROSS THE ADIRONDACKS WITH LITTLE OR NO NO ACCUMULATIONS
EXPECTED. QPF AMOUNTS WILL RANGE FROM A FEW HUNDREDTHS TO A FEW
TENTHS OF AN INCH AGAIN.
DRY AND COLD WEATHER WILL RETURN FRIDAY NIGHT INTO SATURDAY
NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/WASULA
NEAR TERM...IAA/HWJIV
SHORT TERM...WASULA
LONG TERM...IAA
AVIATION...BGM
FIRE WEATHER...WASULA
HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
135 PM EDT THU OCT 11 2012
.SYNOPSIS...
17Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A RATHER UNAMPLIFIED UPPER
LEVEL PATTERN OVER MUCH OF THE CONUS. MAIN NORTHERN STREAM FLOW
ARRIVES OVER THE BRITISH COLUMBIA COAST OVER TOP OF A REX BLOCK
PATTERN AND THEN RIDES ALONG THE US/CANADIAN BORDER ALONG THE
SOUTHERN PERIPHERY OF AN ELONGATED TROUGH IN PLACE OVER
CENTRAL/EASTERN CANADA. CLOSER TO HOME...UPPER LEVEL RIDGING OVER
THE GULF OF MEXICO IS BEGINNING TO AMPLIFY TO THE NORTH AND
NORTHEAST IN RESPONSE TO HEIGHT FALLS SPREADING INTO THE SW STATES
AHEAD OF A POTENT UPPER LOW ON THE SOUTHERN END OF THE REX BLOCK.
THIS RIDGING WILL CONTINUE TO EXPAND OVER OUR REGION AND HELP EXTEND
THE STRETCH OF DRY AND PLEASANT WEATHER INTO THE WEEKEND. 12Z KTBW
SOUNDING SHOWS A DRY PROFILE THROUGH ALMOST ALL OF THE TROPOSPHERE
WITH A SUBSIDENCE INVERSION AT 900MB AND A PW UNDER 1".
AT THE SURFACE...FORECAST AREA RESIDES WITHIN A LOW LEVEL EASTERLY
FLOW AROUND THE SOUTHERN PERIPHERY OF 1027MB HIGH PRESSURE CENTERED
OVER THE EASTERN TN VALLEY. DUE TO NEARLY 100% OF THE POSSIBLE
INSOLATION...TEMPERATURES HAVE REBOUNDED INTO THE LOWER TO MIDDLE
80S...ON THEIR WAY TO LATE AFTERNOON HIGHS IN THE MIDDLE TO UPPER
80S. A FEW-SCT SHALLOW CU FIELD HAS DEVELOPED IN SPOTS...HOWEVER
CROSS-SECTION PLOTS SHOW THAT LOW LEVEL MOISTURE IS VERY SHALLOW
WITH THETA-E VALUES WELL BELOW 320K ABOVE 850MB. THESE CONDITIONS
WILL PREVENT ANY SIGNIFICANT VERTICAL GROWTH AND KEEP OUR SKIES
PARTLY TO MOSTLY SUNNY THROUGH THE DAYLIGHT HOURS.
&&
.SHORT TERM (TONIGHT THROUGH SATURDAY)...
"CHAMBER OF COMMERCE" WEATHER WILL CONTINUE ALONG THE FLORIDA WEST
COAST THROUGH FRIDAY WITH SEASONABLE TEMPERATURES...AMBLE
SUNSHINE...AND DRY CONDITIONS.
TONIGHT...FEW-SCT CU QUICKLY DISSIPATE TOWARDS SUNSET PROVIDING
MOSTLY CLEAR/CLEAR SKIES INTO THE OVERNIGHT. THE GRADIENT WILL
TIGHTEN WHICH SHOULD HELP PREVENT A SIGNIFICANT AMOUNT OF
RADIATIONAL COOLING/RADIATION FOG LATE TONIGHT...HOWEVER STILL
EXPECTING NORMALLY COLDER AND INLAND LOCATIONS TO BOTTOM OUT IN THE
60S BY SUNRISE. A FEW OF THE COOLEST SPOTS...ESPECIALLY NORTH OF
BROOKSVILLE MAY BRIEFLY REACH THE UPPER 50S.
FRIDAY/FRIDAY NIGHT...ANOTHER PLEASANT AND DRY DAY ON TAP.
TEMPERATURES AND SKY CONDITIONS WILL BE VERY SIMILAR TO WHAT IS
OCCURRING TODAY. ONLY REAL DIFFERENCE WILL BE A SLIGHTLY
STRONGER/MORE GUSTY EAST/NE BREEZE DURING THE LATE MORNING/AFTERNOON
HOURS DUE TO DIURNAL MIXING OF SOME STRONGER MOMENTUM NEAR THE TOP
OF THE BOUNDARY LAYER COMPARED TO TODAY. FRIDAY NIGHT WILL SEE A
REINFORCING AND EVEN STRONGER RIDGE OF HIGH PRESSURE BUILD OVER AND
DOWN THE EASTERN SEABOARD RESULTING IN AN EVEN STRONGER PRESSURE
GRADIENT ACROSS THE PENINSULA. THIS TIGHTER GRADIENT ALONG WITH A
SLIGHT INCREASE IN SURFACE MOISTURE OFF THE ATLANTIC SHOULD KEEP LOW
TEMPS A COUPLE DEGREES COOLER THAN WHAT WE ARE FORECASTING FOR
TONIGHT.
SATURDAY...GENERALLY DRY AND SEASONABLE SENSIBLE WEATHER. THE
TIGHTER PRESSURE GRADIENT WILL CONTINUE THE INCREASE IN DIURNAL
GUSTY WINDS DURING THE LATE MORNING AND AFTERNOON...WITH FREQUENT
GUSTS OF 20 TO 25 MPH APPEARING LIKELY. OF NOTE...GFS/NAM BOTH
SHOWING (TO SOME DEGREE) A SURGE IN LOW LEVEL MOISTURE BELOW 700MB
ARRIVING WITHIN THE NE FLOW INTO THE SOUTHERN HALF OF THE PENINSULA
LATE FRIDAY NIGHT AND SATURDAY. FOR NOW WILL ONLY SHOW AN INCREASE
IN COVERAGE WITH RESPECT TO THE DIURNAL CUMULUS FIELD TO THE SOUTH
OF I-4. NAM IS HINTING AT SOME SHOWER POTENTIAL DOWN TOWARD FT MYERS
ASSOCIATED WITH THIS SURGE. THIS SEEMS UNLIKELY FOR THE WEST COAST
OF FLORIDA GIVEN THE SHALLOW NATURE OF THE MOISTURE. MORE LIKELY TO
SEE ANY FORCED SPEED CONVERGENCE SHOWERS OVER TOWARD THE SOUTHEAST
COAST OF THE STATE...BUT WILL CONTINUE TO MONITOR WITH FUTURE NWP
GUIDANCE. FOR NOW WILL KEEP POPS AT SILENT 10% DOWN TOWARD FT MYERS
AND LEAVE SHOWER MENTION OUT OF THE FORECAST.
&&
.LONG TERM (SATURDAY NIGHT - WEDNESDAY)...
AN UPPER LEVEL RIDGE INITIALLY ACROSS THE GULF REGION FLATTENS
AND THEN SHIFTS WEST AS UPPER LEVEL TROUGHING SETTLES IN ACROSS
THE EASTERN U.S. MON AND RESIDES THERE THROUGH THE REMAINDER OF
THE PERIOD. A HIGH PRESSURE CENTER OFF THE MID-ATLANTIC COAST
MOVES EAST THROUGH MON AS IT RIDGES BACK TO THE EAST GULF. THIS
RIDGE BEGINS TO WEAKEN MON AS A FRONTAL BOUNDARY SAGS INTO THE
SE U.S. THE BOUNDARY STALLS AND WASHES OUT NORTH OF THE AREA
TUE AS HIGH PRESSURE MOVES IN FROM THE WEST WED. MEANWHILE A LOW
PRESSURE AREA MOVES NORTH OVER THE ATLANTIC...ALONG OR EAST OF
LONGITUDE 70...FROM NEAR HISPANIOLA.
THE ATMOSPHERE REMAINS FAIRLY DRY AND WITH LIMITED ENERGY
AVAILABLE WILL KEEP THE FORECAST RAIN FREE. TEMPERATURES RUN
ABOVE NORMAL ALTHOUGH THEY WILL DIP A DEGREE OR TWO THROUGH THE
PERIOD. ROBUST EASTERLY WINDS BEGIN TO DIMINISH MON AND BECOME
MORE NORTHERLY BUT WITH AFTERNOON SEA BREEZES.
&&
.AVIATION...
VFR NEXT 24 HOURS. LOW CHANCE OF BRIEF MVFR VISIBILITIES MAINLY AT
LAL AND PGD NEAR SUNRISE FRIDAY.
&&
.MARINE...
A RIDGE OF HIGH PRESSURE WILL REMAIN TO THE NORTH OF THE FORECAST
WATERS THROUGH FRIDAY. A TIGHTENING GRADIENT OVER THE EASTERN GULF
AROUND THIS RIDGE WILL LEAD TO PERIODS OF CAUTIONARY LEVEL
WINDS...ESPECIALLY OFFSHORE. FRIDAY NIGHT AND SATURDAY...AN EVEN
STRONG RIDGE OF HIGH PRESSURE WILL BUILD DOWN THE EASTERN ATLANTIC
SEABOARD RESULTING IN WIDESPREAD CAUTIONARY TO POTENTIAL LOW END
ADVISORY LEVEL WINDS FOR THE EASTERN GULF OF MEXICO.
&&
.FIRE WEATHER...
A DRY BUT SEASONABLE AIRMASS WILL REMAIN IN PLACE THE NEXT COUPLE OF
DAYS. FRIDAY SHOULD BE THE DRIEST DAY OF THE SHORT TERM WHEN MANY
INLAND LOCATIONS SEE RELATIVE HUMIDITY VALUES DROP INTO THE UPPER
30S AND LOWER 40S DURING THE AFTERNOON. CURRENT FORECAST DOES NOT
SUPPORT ANY CRITICAL LEVELS OF RELATIVE HUMIDITY AND ERC VALUES
REMAIN QUITE LOW. A SLOW INCREASE IN LOW LEVEL MOISTURE OFF THE
ATLANTIC SHOULD PREVENT CRITICAL LEVELS OF RELATIVE HUMIDITY FROM
BEING REACHED DURING THE UPCOMING WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 68 86 68 87 / 0 0 0 0
FMY 68 88 68 88 / 0 0 0 10
GIF 64 87 66 89 / 0 0 0 0
SRQ 67 87 67 88 / 0 0 0 10
BKV 60 87 61 87 / 0 0 0 0
SPG 72 85 73 86 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
AVIATION...JILLSON
LONG TERM...RUDE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1015 AM EDT THU OCT 11 2012
.UPDATE (REST OF TODAY AND TONIGHT)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A RATHER UNAMPLIFIED UPPER
LEVEL PATTERN OVER MUCH OF THE CONUS THIS MORNING. MAIN NORTHERN
STREAM FLOW ARRIVES OVER TOP OF A REX BLOCK PATTERN OVER THE PACIFIC
COAST AND THEN RIDES ALONG THE US/CANADIAN BORDER ALONG THE SOUTHERN
PERIPHERY OF AN ELONGATED TROUGH IN PLACE OVER CENTRAL/EASTERN
CANADA. CLOSER TO HOME...UPPER LEVEL RIDGING OVER THE GULF OF MEXICO
IS BEGINNING TO AMPLIFY TO THE NORTH AND NORTHEAST IN RESPONSE TO
HEIGHT FALLS SPREADING OVER THE SW STATES AHEAD OF A POTENT UPPER
LOW ON THE SOUTHERN END OF THE REX BLOCK. THIS RIDGING WILL CONTINUE
TO EXPAND OVER OUR REGION AND HELP EXTEND THE STRETCH OF DRY AND
PLEASANT WEATHER INTO THE WEEKEND. 12Z KTBW SOUNDING SHOWS A DRY
PROFILE THROUGH ALMOST ALL OF THE TROPOSPHERE WITH A SUBSIDENCE
INVERSION AT 900MB AND A PW UNDER 1".
AT THE SURFACE...FORECAST AREA RESIDES WITHIN A LOW LEVEL EASTERLY
FLOW AROUND THE SOUTHERN PERIPHERY OF 1027MB HIGH PRESSURE CENTERED
OVER THE EASTERN TN VALLEY. DUE TO NEARLY 100% OF THE POSSIBLE
INSOLATION...TEMPERATURES ARE QUICKLY REBOUNDING THROUGH THE 70S...
ON THEIR WAY TO AFTERNOON HIGHS IN THE MIDDLE TO UPPER 80S. MAY SEE
A FEW-SCT SHALLOW CU FIELD THIS AFTERNOON...HOWEVER CROSS-SECTION
PLOTS SHOW THAT LOW LEVEL MOISTURE IS VERY SHALLOW AND WILL KEEP
SKIES MOSTLY SUNNY IN THE GRIDS.
ANY FEW-SCT CU QUICKLY DISSIPATE TOWARDS SUNSET PROVIDING MOSTLY
CLEAR/CLEAR SKIES INTO THE OVERNIGHT. THE GRADIENT WILL TIGHTEN
LATER TODAY INTO TONIGHT WHICH SHOULD HELP PREVENT A SIGNIFICANT
AMOUNT OF RADIATIONAL COOLING/RADIATION FOG LATE TONIGHT...HOWEVER
STILL EXPECTING NORMALLY COLDER AND INLAND LOCATIONS TO BOTTOM OUT
IN THE 60S BY SUNRISE.
&&
.PREVIOUS DISCUSSION (FRIDAY - SATURDAY)...
A REINFORCING SURGE OF DRY AIR ACCOMPANYING A WEAK COOL FRONT NOW
OVER THE NORTHERN PENINSULA EARLY THIS MORNING WILL MOVE INTO WEST
CENTRAL AND SOUTHWEST FLORIDA DURING TODAY AS SURFACE HIGH PRESSURE
BUILDS IN OVER THE MID ATLANTIC. A DRY AND STABLE AIR MASS WILL
SUPPORT PLEASANT DRY WEATHER WITH LOWER HUMIDITY VALUES UNDER MOSTLY
SUNNY SKIES WITH TEMPERATURES CLIMBING INTO THE MID AND UPPER 80S.
TONIGHT THROUGH SATURDAY HIGH PRESSURE ALONG THE MID ATLANTIC WILL
BE REINFORCED BY ANOTHER STRONGER HIGH MOVING SOUTHEAST FROM THE
GREAT LAKES REGION AS UPPER RIDGING BUILDS IN OVER THE GULF IN
RESPONSE TO THE CLOSED LOW OVER CALIFORNIA OPENING UP AND MOVING
EAST INTO THE FOUR-CORNERS REGION. A DRY SUBSIDENT AIR MASS UNDER
THE RIDGING WILL CONTINUE TO SUPPORT PLEASANT DRY WEATHER ACROSS
THE ENTIRE FORECAST AREA WITH CLEAR NIGHTS AND MOSTLY SUNNY DAYS.
DAYTIME TEMPERATURES WILL RUN SOME 2 TO 4 DEGREES ABOVE NORMAL
WITH HIGHS CLIMBING INTO THE MID AND UPPER 80S...WHILE THE DRY AIR
MASS AND CLEAR SKIES WILL ALLOW NIGHTTIME LOWS TO RUN BELOW NORMAL
WITH LOWS IN THE UPPER 50S TO LOWER 60S OVER THE NATURE COAST...AND
MID TO UPPER 60S CENTRAL AND SOUTH...EXCEPT LOWER 70S ALONG THE
IMMEDIATE COAST.
&&
.AVIATION...
VFR NEXT 24 HOURS. SOME PATCHY GROUND FOG POSSIBLE AGAIN FRIDAY
MORNING BUT PROBABILITIES TOO LOW TO MENTION IN TAFS.
&&
.MARINE...
STRONGER SURFACE HIGH PRESSURE BUILDING IN OVER THE MID ATLANTIC
WILL SUPPORT AN UPTICK IN THE NORTHEAST WIND FLOW OVER THE GULF
WATERS TODAY...AND WILL THEN HELP TO TIGHTEN THE PRESSURE GRADIENT
ACROSS THE REGION TONIGHT THROUGH FRIDAY WHICH WILL RESULT IN A
BREEZY NORTHEAST TO EASTERLY WIND FLOW DEVELOPING WITH SPEEDS
LIKELY TO INCREASE TOWARD EXERCISE CAUTION LEVELS DURING FRIDAY
AND FRIDAY NIGHT...ESPECIALLY OVER THE OFFSHORE WATERS. DURING
FRIDAY NIGHT AND SATURDAY THE HIGH ALONG THE MID ATLANTIC WILL BE
REINFORCED BY YET AN EVEN STRONGER RIDGE BUILDING SOUTHEAST FROM
THE GREAT LAKES REGION WHICH WILL KEEP WIND AND SEAS ELEVATED
THROUGH THE UPCOMING WEEKEND...WITH EASTERLY SURGES LIKELY TO
PRODUCE ADDITIONAL PERIODS OF EXERCISE CAUTION OR EVEN LOW END
SMALL CRAFT CONDITIONS. LIGHTER WINDS WILL RETURN TO THE WATERS
EARLY NEXT WEEK AS THE HIGH WEAKENS AND SHIFTS EAST INTO THE
ATLANTIC AHEAD OF THE NEXT FRONT MOVING INTO THE SOUTHEASTERN STATES.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 88 67 87 68 / 0 0 0 0
FMY 87 68 87 68 / 0 0 0 0
GIF 88 67 87 68 / 0 0 0 0
SRQ 87 68 88 67 / 0 0 0 0
BKV 88 59 86 60 / 0 0 0 0
SPG 86 72 86 72 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...JILLSON
PREVIOUS DISCUSSION...MCMICHAEL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
634 PM MDT FRI OCT 12 2012
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 1245 PM MDT FRI OCT 12 2012
LATEST THINKING IS THERE WILL BE TWO POTENTIAL ROUNDS OF
PRECIPITATION ASSOCIATED WITH THE LARGE UPPER LOW OVER SOUTHERN
NEVADA THAT WILL AFFECT THE REGION IN THE NEXT 18 HOURS. FIRST...A
SHORT WAVE TROUGH CURRENTLY LIFTING NORTHEAST ACROSS THE OKLAHOMA
PANHANDLE WILL INITIATE SHOWERS AND ISOLATED THUNDERSTORMS THIS
AFTERNOON FROM SOUTHWEST TO NORTHEAST BETWEEN ABOUT 20Z AND 01Z.
THE NAM SHOWS DECENT ELEVATED CAPE AROUND 1000 J/KG HOWEVER 0-6 KM
BULK SHEAR IS ONLY ABOUT 25 KTS THIS AFTERNOON. SUB-SEVERE HAIL
AND C-G LIGHTNING ARE THOUGHT TO BE THE MAIN THREATS. THIS FIRST
ROUND OF PRECIP SHOULD BEGIN TO WEAK AND LOSE COVERAGE AS THE
UPPER TROUGH LIFTS FURTHER NORTHEAST AFTER 00Z. ONE MODULATING
INFLUENCE THIS AFTERNOON IS POSITION OF 250 MB JET. THE CURRENT
LOCATION PUTS OUR AREA IN THE RIGHT EXIT REGION WHICH MAY EXPLAIN
THE LOOK OF THE HRRR REFLECTIVITY FIELDS LATER THIS AFTERNOON
WITH PRECIPITATION SPLITTING AND WEAKENING.
THE BULK OF THE SYSTEM IS EXPECTED TO APPROACH THE AREA OVERNIGHT...
BUT THINK BETTER CHANCES OF SHOWERS AND THUNDERSTORMS WILL BE IN
THE SOUTHEAST COUNTIES IN THE 06-12Z TIME FRAME. THE NAM SHOWS
SOME CAPE IN THE -10 TO -20 C HAIL GROWTH REGION AT THAT TIME,
PLUS 0-6 KM SHEAR WILL INCREASE TO AROUND 70 KTS INDICATING A FEW
STORMS OVERNIGHT HAVE THE POTENTIAL TO PRODUCE SEVERE HAIL IF
THINGS COME TOGETHER AS PLANNED. ALSO KEPT MENTION OF AREAS OF FOG
OVERNIGHT WITH LOW LEVEL RH VALUES ABOVE 95 PERCENT.
ON SATURDAY...SOMEWHAT LESS CERTAIN REGARDING POTENTIAL FOR
SCATTERED SHOWERS DURING THE AFTERNOON. LAPSE RATES NOT ALL THAT
STEEP AS UPPER SYSTEM MOVES OVERHEAD...AND SUBSIDENCE BEHIND UPPER
TROUGH WITH RIDGING MOVING IN WILL COINCIDE WITH PEAK HEATING. KEPT
SLIGHT CHANCES FOR SHOWERS GOING FOR NOW BUT CONFIDENCE IS NOT THAT
HIGH FOR DECENT COVERAGE IF LATEST NAM-GFS VERIFY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 240 PM MDT FRI OCT 12 2012
THE CLOSED LOW THAT BROUGHT PRECIP WILL EXIT THE AREA EARLY SATURDAY
EVENING. MODELS PLACE PRECIP WELL WEST OF THE LOW WHERE A SHORT
WAVE RIDGE WILL BE. AM THINKING IF ANY PRECIP WILL DEVELOP IT
WILL BE JUST BEHIND THE CLOSED LOW. AM NOT TOO CONFIDENT THERE
WILL BE ANY PRECIP ACCOMPANYING THE CLOSED LOW AS IT MOVES EAST
DUE TO 700-500MB LAPSE RATES LESS THAN 6C/KM. HOWEVER WITH MODELS
SHOWING PRECIP FOLLOWING THE CLOSED LOW...WILL KEEP THE MENTION OF
SLIGHT CHANCES GOING DURING THE EARLY EVENING AS THE LOW EXITS THE
AREA.
SUNDAY AND SUNDAY NIGHT AN UPPER LEVEL RIDGE WILL BUILD OVER THE
INTERMOUNTAIN WEST...EXTENDING OVER THE TRI-STATE AREA. A MINOR
SHORT WAVE TROUGH WILL MOVE THROUGH THE FLOW OVER THE NORTHEAST PART
OF THE AREA. HOWEVER WITH LITTLE MOISTURE TO WORK WITH...AM NOT
EXPECTING ANYTHING MORE THAN A FEW CLOUDS TO DEVELOP. BEHIND THE
SHORT WAVE TROUGH WINDS WILL INCREASE DURING THE AFTERNOON...WITH
GUSTS NEAR 30MPH AS STRONG WINDS ABOVE THE SURFACE MIX DOWN.
TEMPERATURES FOR SATURDAY THROUGH SUNDAY NIGHT WILL BE NEAR NORMAL.
FOR MONDAY THROUGH FRIDAY THE PERIOD WILL BE PRIMARILY DRY. TUESDAY
AND WEDNESDAY A SHORT WAVE TROUGH MOVES THROUGH THE FLOW OVER THE
AREA...WITH A COLD FRONT FOLLOWING THE FIRST SHORT WAVE TUESDAY
NIGHT. THERE IS SOME MOISTURE TO WORK WITH...SO HAVE INCLUDED
SLIGHT CHANCES FOR THE FAR NORTHEAST PART OF THE AREA TUESDAY
NIGHT. ANOTHER STRONGER COLD FRONT MOVES THROUGH WEDNESDAY NIGHT.
THERE IS LESS MODEL AGREEMENT WITH PRECIP DEVELOPING AS THE SECOND
COLD FRONT MOVES THROUGH...SO WILL CONTINUE WITH THE DRY FORECAST.
TEMPERATURES THROUGH THIS PERIOD WILL BE ABOVE NORMAL PRIOR TO THE
FIRST COLD FRONT THEN NEAR NORMAL THROUGH THE REST OF THE WEEK
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 625 PM MDT FRI OCT 12 2012
HAVE STARTED THE TAF PERIOD WITH VFR CONDITIONS AND SCATTERED
HIGHER CLOUD COVER AS THE SUBSIDENT AREA BETWEEN THE INITIAL SHORT
WAVE TROUGH AND THE SUBSEQUENT MAIL UPPER LOW MOVES ACROSS THE
CENTRAL HIGH PLAINS REGION. AFTER 04Z...EXPECT A FEW SHOWERS AND
THUNDERSTORMS TO MOVE ACROSS THE AREA WITH SCATTERED COVERAGE AT
BEST. CONFIDENCE OF ANY ONE STORM MOVING ACROSS EITHER MCK OR GLD
TAF SITES IS FAIRLY LOW...SO HAVE LEFT THEM OUT OF THE PREVAILING
CONDITIONS. DO EXPECT SOME LOWER CLOUDS AND VISIBILITIES WITH MVFR
CONDITIONS TO MAKE THEIR WAY ACROSS THE REGION BRIEFLY AS THE
SURFACE TROUGH AND ATTENDANT WARM FRONT MOVE ACROSS THE REGION
BETWEEN 04-10Z. AFTER 10Z...EXPECT GUSTY NORTHWEST WINDS TO
CONTINUE AS THE LOW PRESSURE SYSTEM MOVING EAST OF THE ROCKIES
CONTINUES TO MOVE ACROSS THE HIGH PLAINS WITH SKIES CLEARING
SOMEWHAT BY 00Z SATURDAY EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DLF
LONG TERM...JTL
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
400 AM CDT THU OCT 11 2012
...UPDATE TO SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1111 PM CDT WED OCT 10 2012
THE 11.00Z 250 HPA RAOB MAP SHOWED CYCLONIC FLOW OFFSHORE AND ACROSS
CA. THE PEAK JET LEVEL WINDS ASSOCIATED WITH THIS FEATURE WAS AROUND
90 KT EXTENDING ACROSS SOUTHERN CALIFORNIA. DOWNSTREAM, A STRONG NORTHWESTERLY
JET EXTENDED FROM THE CENTRAL CANADIAN PRAIRIE PROVINCES SOUTHEAST TO
THE GREAT LAKES REGION. A JET STREAK OF 140 KT WAS OBSERVED FROM KINL
TO KGRB. AT 500 HPA, OUR NEXT WEATHER SYSTEM WAS OBVIOUS PER GEOPOTENTIAL
HEIGHT ANALYSIS, WIND FIELDS AND SATELLITE WATER VAPOR IMAGERY. THIS
FEATURE WAS A 559 DM LOW LOCATED SSW OF KSFO. AN ASSOCIATED COLD POOL
OF -21 DEG C WAS OBSERVED AT KOAK. OTHERWISE, A BROAD TROUGH WAS LOCATED
ACROSS MUCH OF CENTRAL AND EASTERN CANADA WITH MID LEVEL TEMPERATURES
AS COLD AS -37 DEG C ACROSS CENTRAL MANITOBA. AT 700 HPA, -1 DEG C TEMPS
WERE ASSOCIATED WITH THE WEST COAST LOW. TO THE NORTHEAST, IMPRESSIVE
COLD TEMPERATURES AS LOW AS -19 DEG C WERE OBSERVED ACROSS MANITOBA
AND ONTARIO. THE AIRMASS IN THIS REGION WAS ALSO FAIRLY SATURATED. AT
850 HPA, A WARM AIR ADVECTION PATTERN WAS IN PLACE ACROSS THE CENTRAL
AND SOUTHERN PLAINS WITH MANY UPPER AIR SITES REPORTING SEVERAL DEGREES
OF WARMING BETWEEN THE 10.00Z AND 11.00Z FLIGHTS. SOME MOISTURE ADVECTION
WAS NOTED DOWNSTREAM OF THE AFOREMENTIONED LOW ACROSS SOUTHERN CALIFORNIA.
LOW DEWPOINT DEPRESSIONS - ASSOCIATED WITH STRATUS WAS ALSO NOTED ACROSS
PORTIONS OF TEXAS AND OKLAHOMA. AT THE SFC, A PLETHORA OF FRONTS WERE
NOTED ACROSS THE CONUS...ONE ACROSS MONTANA AND THE DAKOTAS, A STATIONARY
FRONT BUCKED UP ACROSS THE ROCKIES EXTENDING INTO PORTIONS OF TEXAS...AND
A COLD FRONT ACROSS THE DEEP SOUTH EXTENDING NE TO NEW ENGLAND. RICH
BOUNDARY LAYER MOISTURE /MARKED BY DEWPOINTS IN THE UPPER 60S DEG F/
WERE SOUTH OF SAID TWO FRONTS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 400 AM CDT THU OCT 11 2012
THIS MORNING:
THE 11-3.9 MICRON SATELLITE IMAGERY SHOWS STRATUS WORKING ITS WAY NORTHWARD
EARLY THIS MORNING. PLAN VIEW RH`S PROGS SHOW NEAR 100 PERCENT SATURATION
WITHIN THE BOUNDARY LAYER, HOWEVER, BUFKIT SOUNDINGS ARE A LITTLE LESS
AGGRESSIVE WITH FOG FORMATION AND LOW LEVEL STRATUS. WILL CONTINUE TO
ADVECT THE CLOUD COVER NORTHWARD THIS MORNING. A LEE LOW WILL STRENGTHEN
THROUGH THE MORNING HOURS AND ALSO TRANSLATE EAST FARTHER. THIS WILL
RESULT IN A MORE DOWNSLOPE SSW/SW WIND FROM THE SFC THROUGH 700 HPA.
AS A RESULT, EXPECT SKIES TO CLEAR THROUGH THE MID MORNING HOURS. DENSE
FOG IS NOT EXPECTED THIS MORNING AS T/TD DEPRESSIONS ARE FAIRLY LARGE
AT THE SURFACE.
TODAY:
A COLD FRONT WILL TRAVERSE ACROSS THE REGION THROUGH THE AFTERNOON.
A STRONG TEMPERATURES GRADIENT IS EXPECTED ACROSS SW KANSAS WITH HIGHS
AROUND 70 DEG F ACROSS THE INTERSTATE 70 CORRIDOR TO VERY WARM TEMPERATURES
IN THE MID TO UPPER 80S DEG F ALONG THE KANSAS/OKLAHOMA BORDER. BOISE
VERIFICATION SHOWS THAT THE NAM12BC MODEL IS PERFORMING BETTER THAN
OTHER GUIDANCE SO WILL GO WITH THIS SOLUTION FOR NOW. 850 HPA WINDS
BEHIND THE FRONT ARE NOT THAT STRONG (~20 KT) SO THERE WILL NOT BE
MUCH WIND WITH THIS FRONT (15-20 KT AT THE SFC).
TONIGHT:
ATTENTION THEN TURNS TO CONVECTIVE PROSPECTS FOR THIS EVENING. MESOSCALE
MODELS SUCH AS THE 00Z/06Z NAM AND THE 00Z ARW-NMM CORE SUGGEST CONVECTION
ALONG THE STATE LINE AFTER SUNSET. THIS ACTIVITY IS IN RESPONSE INCREASING
850 HPA THETA-E ADVECTION AND 850-700 HPA FRONTOGENESIS. THE UPPER LEVEL
DISTURBANCE MENTIONED IN THE SYNOPSIS WILL STILL BE WAY WEST OF THE
REGION, HOWEVER, FORECAST MUCAPE OF 1500 J/KG...30-35 KT OF 0-6 KM BULK
SHEAR...AND FAIRLY STEEP 700-500 HPA AND 500-300 HPA LAPSE RATES (~7.3
DEG C/KM) SUGGEST THE THREAT FOR A LOW END HAIL EVENT. WILL HIGHLIGHT
THIS CONCERN IN THE HWO. CONVECTION SHOULD BE FAIRLY ELEVATED AS THE
COLD AIR UNDERCUTS BUOYANT PARCELS ALOFT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 322 AM CDT THU OCT 11 2012
STARTING WITH FRIDAY MORNING, THERE WILL BE UPPER DIFFLUENCE OVER
MUCH OF WESTERN KANSAS EARLY FRIDAY, WITH A WARM FRONT STARTING TO
EDGE NORTHWARD DURING THE DAY FRIDAY. THERE COULD BE A FEW
THUNDERSTORMS DOWN IN THE PRATT AND MEDICINE LODGE AREAS EARLY
FRIDAY MORNING. BUT THE MORE DEEPER, UNSTABLE CONVECTIVE MODE WILL
START DURING THE AFTERNOON FRIDAY AND EXTEND INTO THE NIGHT. ALL
MODELS POINT TOWARDS AROUND 1000 J/KG OF CAPE DEVELOPING FRIDAY
AFTERNOON AS THE SURFACE WARMS UP SOUTH OF THE WARM FRONT. A WAVE
OF 500MB VORTICITY STREAMS NORTHEASTWARD ACROSS SOUTHERN KANSAS
FRIDAY EVENING AROUND 00Z, WITH A 70 TO 80 KNOT 500MB JET CURVING
FROM NORTHERN NEW MEXICO TO WESTERN NEBRASKA. THIS JET WILL
INCREASE UPPER LEVEL FORCING FOR STRONGER VERTICAL MOTION TO DEVELOP,
WHICH WILL ALSO SHARPEN THE SHEAR PROFILE. HAVE OPTED TO PLACE
T+RW(M) WEATHER TYPE IN FROM APPROXIMATELY 20Z FRIDAY THROUGH 09Z
SATURDAY MORNING. LARGE HAIL LOOKS TO BE THE PRIMARY RISK FACTOR
FRIDAY EVENING AND FRIDAY NIGHT, BUT LOWER LEVEL CIRCULATION WILL
NEED TO BE WATCHED FOR THE POSSIBLE DEVELOPMENT OF TORNADOES FRIDAY
NIGHT. THIS SHIFT HAS DECIDED TO PRODUCE A MULTIMEDIA BRIEFING AND
WILL PLACE IT ON OUR WEB PAGE TO HEIGHTEN AWARENESS TO THIS SEVERE
POTENTIAL.
SATURDAY WILL SEE THE ABOVE MENTIONED FRONT MOVE BACK SOUTHEASTWARD
AS A COLD FRONT, WITH THE BASE OF THE UPPER TROUGH ADVANCING INTO
FAR WESTERN KANSAS BY 18Z SATURDAY AND TO EAST-CENTRAL KANSAS BY 00Z
SUNDAY. LOWER 30 PERCENT POPS WILL LINGER IN MY FAR SOUTHEASTERN
ZONES NEAR MEDICINE LODGE SATURDAY MORNING WHERE THE COLD FRONT
SHOULD BE, AND THEN DIMINISH TO LESS THAN 10 PERCENT BY SATURDAY
EVENING. AFTER SATURDAY, POPS LOOK NIL FOR SUNDAY THROUGH
WEDNESDAY AS A NEAR ZONAL FLOW ESTABLISHES A HOLD IN THE UPPER
FLOW. ONE SMALL WAVE MOVES THROUGH PER THE ECMWF MODEL ON
WEDNESDAY, BUT THE UPPER DYNAMICS WITH THIS WAVE SHOULD STAY NORTH
OF OUR FORECAST AREA OF SOUTHWEST KANSAS.
TEMPERATURES WILL START OUT DIVIDED ON FRIDAY WITH CLOUDS AND COOL
AIR KEEPING AREAS NORTH OF A LACROSSE TO SYRACUSE LINE WITH MAX
TEMPERATURES IN THE UPPER 50S. SOUTH OF THAT LINE AND SOUTH OF THE
AFTERNOON WARM FRONT, TEMPERATURES WILL APPROACH THE LOWER 70S FROM
LIBERAL TO COLDWATER. MAXIMUM TEMPERATURES FROM SATURDAY THROUGH
TUESDAY SHOULD TOP OUT IN THE UPPER 70S TO LOWER 80S AS A WEST FLOW
DEVELOPS ALOFT, WITH PERHAPS TUESDAY THE WARMEST DAY. THAT WAVE
MENTIONED ABOVE FOR WEDNESDAY WILL BRING CLOUDS AND SLIGHTLY COOLER
AIR, PRODUCING HIGHS ON WEDNESDAY IN THE 70S. MINIMUM TEMPERATURES
SATURDAY MORNING NEAR 50F IN ALONG THE COLORADO BORDER AND AROUND
THE MID 60S NEAR PRATT, WILL LOWER TO THE LOWER 40S TO MID 50S (SE)
SUNDAY, BUT THEN WARM INTO THE 50S MON, TUE, AND WED. LOOKING
AHEAD, THURSDAY`S MINS COULD DIP BACK INTO THE 40S AS COOL AIR
INFILTRATES WESTERN KANSAS FROM THE NORTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1234 AM CDT THU OCT 11 2012
MAIN CONCERN FOR 06Z TAFS IS CIGS. LOW PRESSURE LOCATED ACROSS THE LEE
OF THE ROCKIES WILL KEEP SSE WINDS IN THE FORECAST THROUGH THE OVERNIGHT
HOURS. LOW STRATUS HAS BEGUN TO CREEP CLOSER WITH PRATT REPORTING CLOSE
TO MVFR CIGS. AN INSPECTION OF PLAN VIEW RH PROGS WITHIN THE BOUNDARY
LAYER SHOW NEAR SATURATION, HOWEVER, INSPECTING BUFKIT FORECAST SOUNDINGS
SHOW LESS OF PROBLEM THAN WHAT THE HRRR IS SUGGESTING (NAMELY VIS).
ANYWAY, WILL PUT MVFR CIGS FOR KGCK/KDDC THIS MORNING. CONFIDENCE IS
LOWER FOR MVFR CIGS AT KHYS DUE TO A DRIER PROFILE. BY MID MORNING,
A DOWNSLOPE SW IS EXPECTED AHEAD OF A COLD FRONT WHICH SHOULD ALLOW
FOR VFR CIGS. THIS FRONT WILL TRAVERSE ACROSS MUCH OF THE REGION BY
THE AFTERNOON. SECOND CONCERN IS CONVECTION LATE THIS EVENING, HOWEVER,
THIS ACTIVITY SHOULD REMAIN SOUTH OF THE TERMINALS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 82 49 68 61 / 10 20 40 70
GCK 80 45 60 58 / 0 10 60 70
EHA 86 49 68 52 / 10 30 60 70
LBL 86 51 70 59 / 10 40 60 70
HYS 72 44 59 58 / 0 10 30 70
P28 85 60 73 63 / 20 70 50 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...BURKE
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
329 AM CDT THU OCT 11 2012
...UPDATED FOR THE LONG RANGE FORECAST...
.SYNOPSIS...
ISSUED AT 1111 PM CDT WED OCT 10 2012
THE 11.00Z 250 HPA RAOB MAP SHOWED CYCLONIC FLOW OFFSHORE AND ACROSS
CA. THE PEAK JET LEVEL WINDS ASSOCIATED WITH THIS FEATURE WAS AROUND
90 KT EXTENDING ACROSS SOUTHERN CALIFORNIA. DOWNSTREAM, A STRONG NORTHWESTERLY
JET EXTENDED FROM THE CENTRAL CANADIAN PRAIRIE PROVINCES SOUTHEAST TO
THE GREAT LAKES REGION. A JET STREAK OF 140 KT WAS OBSERVED FROM KINL
TO KGRB. AT 500 HPA, OUR NEXT WEATHER SYSTEM WAS OBVIOUS PER GEOPOTENTIAL
HEIGHT ANALYSIS, WIND FIELDS AND SATELLITE WATER VAPOR IMAGERY. THIS
FEATURE WAS A 559 DM LOW LOCATED SSW OF KSFO. AN ASSOCIATED COLD POOL
OF -21 DEG C WAS OBSERVED AT KOAK. OTHERWISE, A BROAD TROUGH WAS LOCATED
ACROSS MUCH OF CENTRAL AND EASTERN CANADA WITH MID LEVEL TEMPERATURES
AS COLD AS -37 DEG C ACROSS CENTRAL MANITOBA. AT 700 HPA, -1 DEG C TEMPS
WERE ASSOCIATED WITH THE WEST COAST LOW. TO THE NORTHEAST, IMPRESSIVE
COLD TEMPERATURES AS LOW AS -19 DEG C WERE OBSERVED ACROSS MANITOBA
AND ONTARIO. THE AIRMASS IN THIS REGION WAS ALSO FAIRLY SATURATED. AT
850 HPA, A WARM AIR ADVECTION PATTERN WAS IN PLACE ACROSS THE CENTRAL
AND SOUTHERN PLAINS WITH MANY UPPER AIR SITES REPORTING SEVERAL DEGREES
OF WARMING BETWEEN THE 10.00Z AND 11.00Z FLIGHTS. SOME MOISTURE ADVECTION
WAS NOTED DOWNSTREAM OF THE AFOREMENTIONED LOW ACROSS SOUTHERN CALIFORNIA.
LOW DEWPOINT DEPRESSIONS - ASSOCIATED WITH STRATUS WAS ALSO NOTED ACROSS
PORTIONS OF TEXAS AND OKLAHOMA. AT THE SFC, A PLETHORA OF FRONTS WERE
NOTED ACROSS THE CONUS...ONE ACROSS MONTANA AND THE DAKOTAS, A STATIONARY
FRONT BUCKED UP ACROSS THE ROCKIES EXTENDING INTO PORTIONS OF TEXAS...AND
A COLD FRONT ACROSS THE DEEP SOUTH EXTENDING NE TO NEW ENGLAND. RICH
BOUNDARY LAYER MOISTURE /MARKED BY DEWPOINTS IN THE UPPER 60S DEG F/
WERE SOUTH OF SAID TWO FRONTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 254 PM CDT WED OCT 10 2012
THE MAIN FORECAST CHALLENGES ARE HIGHS THURSDAY AND THUNDERSTORM
CHANCES LATE THURSDAY AFTERNOON.
AS AN UPPER-LOW TAKES SHAPE OVER THE SOUTHWESTERN UNITED STATES, A
STRONG SURFACE HIGH WILL MOVE SOUTHEASTWARD FROM NORTHERN ALASKA
INTO THE NORTHERN PLAINS IN RESPONSE TO UPPER-LEVEL TROUGHING OVER
THE GREAT LAKES. MID-LEVEL DOWNSLOPE FLOW OVER THE SOUTHERN HIGH PLAINS
AND MEXICO WITH THE SOUTHWESTERN SYSTEM WILL ENCOURAGE LEE TROUGHING
OVER THE SOUTHERN HIGH PLAINS, WITH GULF MOISTURE RETURN INTO THE
SOUTHERN PLAINS. A BAROCLINIC ZONE WILL BECOME ESTABLISHED ACROSS
SOUTHERN KANSAS BY LATE THURSDAY AFTERNOON. GULF MOISTURE CONVERGING
ALONG THIS FRONT MAY WILL LEAD TO THUNDERSTORM DEVELOPMENT BY LATE
AFTERNOON NEAR THE OKLAHOMA STATE LINE. WITH SURFACE BASED CAPE
VALUES AROUND 1000-1500 J/KG AND DECENT SHEAR, SOME HAIL IS POSSIBLE
UP TO THE SIZE OF QUARTERS. HIGHS THURSDAY SHOULD RANGE FROM THE
UPPER 60S AND LOWER 70S ACROSS NORTHERN TREGO AND ELLIS COUNTIES
TO THE UPPER 80S TO EVEN LOWER 90S OVER BARBER AND COMANCHE
COUNTIES.
IN THE NEAR TERM, LOW LEVEL WARM ADVECTION WAS BEGINNING ACROSS
WEST TEXAS THIS AFTERNOON. THE NAM MODEL SOUNDINGS SUGGEST LOW
STRATUS FORMATION BY 09Z AND THEN ERODING BY 15Z WITH DAYTIME
HEATING. LOWS SHOULD BE HELD UP IN THE MID TO HIGH 40S DUE TO THE
SOUTH WIND AT 10 KTS, CLOUD COVER AND INCREASING DEWPOINTS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 322 AM CDT THU OCT 11 2012
STARTING WITH FRIDAY MORNING, THERE WILL BE UPPER DIFFLUENCE OVER
MUCH OF WESTERN KANSAS EARLY FRIDAY, WITH A WARM FRONT STARTING TO
EDGE NORTHWARD DURING THE DAY FRIDAY. THERE COULD BE A FEW
THUNDERSTORMS DOWN IN THE PRATT AND MEDICINE LODGE AREAS EARLY
FRIDAY MORNING. BUT THE MORE DEEPER, UNSTABLE CONVECTIVE MODE WILL
START DURING THE AFTERNOON FRIDAY AND EXTEND INTO THE NIGHT. ALL
MODELS POINT TOWARDS AROUND 1000 J/KG OF CAPE DEVELOPING FRIDAY
AFTERNOON AS THE SURFACE WARMS UP SOUTH OF THE WARM FRONT. A WAVE
OF 500MB VORTICITY STREAMS NORTHEASTWARD ACROSS SOUTHERN KANSAS
FRIDAY EVENING AROUND 00Z, WITH A 70 TO 80 KNOT 500MB JET CURVING
FROM NORTHERN NEW MEXICO TO WESTERN NEBRASKA. THIS JET WILL
INCREASE UPPER LEVEL FORCING FOR STRONGER VERTICAL MOTION TO DEVELOP,
WHICH WILL ALSO SHARPEN THE SHEAR PROFILE. HAVE OPTED TO PLACE
T+RW(M) WEATHER TYPE IN FROM APPROXIMATELY 20Z FRIDAY THROUGH 09Z
SATURDAY MORNING. LARGE HAIL LOOKS TO BE THE PRIMARY RISK FACTOR
FRIDAY EVENING AND FRIDAY NIGHT, BUT LOWER LEVEL CIRCULATION WILL
NEED TO BE WATCHED FOR THE POSSIBLE DEVELOPMENT OF TORNADOES FRIDAY
NIGHT. THIS SHIFT HAS DECIDED TO PRODUCE A MULTIMEDIA BRIEFING AND
WILL PLACE IT ON OUR WEB PAGE TO HEIGHTEN AWARENESS TO THIS SEVERE
POTENTIAL.
SATURDAY WILL SEE THE ABOVE MENTIONED FRONT MOVE BACK SOUTHEASTWARD
AS A COLD FRONT, WITH THE BASE OF THE UPPER TROUGH ADVANCING INTO
FAR WESTERN KANSAS BY 18Z SATURDAY AND TO EAST-CENTRAL KANSAS BY 00Z
SUNDAY. LOWER 30 PERCENT POPS WILL LINGER IN MY FAR SOUTHEASTERN
ZONES NEAR MEDICINE LODGE SATURDAY MORNING WHERE THE COLD FRONT
SHOULD BE, AND THEN DIMINISH TO LESS THAN 10 PERCENT BY SATURDAY
EVENING. AFTER SATURDAY, POPS LOOK NIL FOR SUNDAY THROUGH
WEDNESDAY AS A NEAR ZONAL FLOW ESTABLISHES A HOLD IN THE UPPER
FLOW. ONE SMALL WAVE MOVES THROUGH PER THE ECMWF MODEL ON
WEDNESDAY, BUT THE UPPER DYNAMICS WITH THIS WAVE SHOULD STAY NORTH
OF OUR FORECAST AREA OF SOUTHWEST KANSAS.
TEMPERATURES WILL START OUT DIVIDED ON FRIDAY WITH CLOUDS AND COOL
AIR KEEPING AREAS NORTH OF A LACROSSE TO SYRACUSE LINE WITH MAX
TEMPERATURES IN THE UPPER 50S. SOUTH OF THAT LINE AND SOUTH OF THE
AFTERNOON WARM FRONT, TEMPERATURES WILL APPROACH THE LOWER 70S FROM
LIBERAL TO COLDWATER. MAXIMUM TEMPERATURES FROM SATURDAY THROUGH
TUESDAY SHOULD TOP OUT IN THE UPPER 70S TO LOWER 80S AS A WEST FLOW
DEVELOPS ALOFT, WITH PERHAPS TUESDAY THE WARMEST DAY. THAT WAVE
MENTIONED ABOVE FOR WEDNESDAY WILL BRING CLOUDS AND SLIGHTLY COOLER
AIR, PRODUCING HIGHS ON WEDNESDAY IN THE 70S. MINIMUM TEMPERATURES
SATURDAY MORNING NEAR 50F IN ALONG THE COLORADO BORDER AND AROUND
THE MID 60S NEAR PRATT, WILL LOWER TO THE LOWER 40S TO MID 50S (SE)
SUNDAY, BUT THEN WARM INTO THE 50S MON, TUE, AND WED. LOOKING
AHEAD, THURSDAY`S MINS COULD DIP BACK INTO THE 40S AS COOL AIR
INFILTRATES WESTERN KANSAS FROM THE NORTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1234 AM CDT THU OCT 11 2012
MAIN CONCERN FOR 06Z TAFS IS CIGS. LOW PRESSURE LOCATED ACROSS THE LEE
OF THE ROCKIES WILL KEEP SSE WINDS IN THE FORECAST THROUGH THE OVERNIGHT
HOURS. LOW STRATUS HAS BEGUN TO CREEP CLOSER WITH PRATT REPORTING CLOSE
TO MVFR CIGS. AN INSPECTION OF PLAN VIEW RH PROGS WITHIN THE BOUNDARY
LAYER SHOW NEAR SATURATION, HOWEVER, INSPECTING BUFKIT FORECAST SOUNDINGS
SHOW LESS OF PROBLEM THAN WHAT THE HRRR IS SUGGESTING (NAMELY VIS).
ANYWAY, WILL PUT MVFR CIGS FOR KGCK/KDDC THIS MORNING. CONFIDENCE IS
LOWER FOR MVFR CIGS AT KHYS DUE TO A DRIER PROFILE. BY MID MORNING,
A DOWNSLOPE SW IS EXPECTED AHEAD OF A COLD FRONT WHICH SHOULD ALLOW
FOR VFR CIGS. THIS FRONT WILL TRAVERSE ACROSS MUCH OF THE REGION BY
THE AFTERNOON. SECOND CONCERN IS CONVECTION LATE THIS EVENING, HOWEVER,
THIS ACTIVITY SHOULD REMAIN SOUTH OF THE TERMINALS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 82 49 68 61 / 10 20 40 70
GCK 80 45 60 58 / 0 10 60 70
EHA 86 49 68 52 / 10 30 60 70
LBL 86 51 70 59 / 10 40 60 70
HYS 72 44 59 58 / 0 10 30 70
P28 85 60 73 63 / 20 70 50 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...FINCH
LONG TERM...BURKE
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1147 PM MDT WED OCT 10 2012
.UPDATE...
ISSUED AT 225 PM MDT WED OCT 10 2012
MADE MINOR ADJUSTMENT TO WX/SKY GRIDS FOR TONIGHT PERIOD...TO
INCREASE SKY COVER AND ADD PATCHY FOG. NAM/RUC BOTH SHOWING DECENT
BL MOISTURE ADVECTING NORTH. WITH BETTER CLEARING SOUTH
COULDNT RULE OUT STRATUS/FOG DEVELOPING AND THEN ADVECTING NORTH
OUT OF SE CO AND SW KS. NOT SURE HOW FAR NORTH THIS WILL GET...SO
I ONLY LIMITED IT TO THE FAR SOUTHERN TIER OF COUNTIES.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 1203 PM MDT WED OCT 10 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW SIMILAR PATTERN AS THE
LAST FEW DAYS...WITH BROAD TROUGH ACROSS CANADA EXTENDING SOUTH
ACROSS THE EASTERN US. A REX BLOCK IS ALSO STILL IN PLACE OFF THE
WESTERN US...WITH A CLOSED UPPER LOW BEGINNING TO MOVE OVER THE
CENTRAL CALIFORNIA COAST. A SHORTWAVE RIDGE EXTENDS NORTH OVER
WESTERN COLORADO AND TOWARDS THE GREAT BASIN. AT THE SURFACE HIGH
PRESSURE EXTENDS FROM THE CENTRAL MISSISSIPPI VALLEY WEST INTO
CENTRAL KANSAS. A LEE TROUGH IS DEEPENING OVER EASTERN
COLORADO...WITH INCREASING PRESSURE GRADIENT OVER WESTERN KS BETWEEN
THESE FEATURES.
GOOD WAA OVERNIGHT TONIGHT...COMBINED WITH MID-HIGH CLOUD COVER
COMPLICATES THE LOW TEMPERATURE. WINDS SHOULD DIMINISH AROUND
SUNSET AS DAYTIME HEATING COMES TO AN END...AND THE LEE TROUGH
AXIS SHIFTS EAST OVER THE CWA...SO WINDS SHOULD NOT BE AS MUCH OF
AN ISSUE. TEMPERATURES CURRENTLY EXPECTED TO BE IN THE 40S ACROSS
MOST OF THE AREA. IF CLOUD COVER WERE TO BE MORE EXTENSIVE WE
MAY SEE OVERNIGHT TEMPS CLOSER TO 50F AT SOME LOCATIONS.
A COLD FRONT WILL PUSH SOUTH OVER THE CWA AS A SHORTWAVE TROUGH
MOVES FROM SOUTHERN CANADA INTO NORTHERN MINNESOTA THURSDAY. WITH
VERY LITTLE IN MOISTURE IN PLACE AND BEST LARGE SCALE ASCENT WELL TO
THE NORTH AND EAST...NO PRECIP IS EXPECTED. LATEST GUIDANCE FAVORS
FRONTAL PASSAGE AROUND 15Z ACROSS MOST OF THE CWA...AND AROUND 18Z
ACROSS THE SOUTHERN HALF OF THE CWA. I HAVE TRENDED TEMPS DOWN
ACCORDINGLY...WITH HIGHS IN THE UPPER 50S/LOW 60S ACROSS THE
NORTH...AND NEAR 70 ACROSS THE SOUTH.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 1251 PM MDT WED OCT 10 2012
SYSTEM CURRENTLY OVER SOUTHERN CALIFORNIA WILL LIFT OUT ACROSS THE
SOUTHERN AND CENTRAL ROCKIES FRIDAY AND SATURDAY. BEST LIFT LOCALLY
WILL OCCUR FRIDAY AFTERNOON THROUGH FRIDAY NIGHT. COOL AND STABLE
CONDITIONS ARE FORECAST FOR FRIDAY WHICH WILL RESULT IN SURFACE
INSTABILITY OF ZERO. HOWEVER...THERE IS WEAK ELEVATED INSTABILITY
AND DEEP LAYER SHEAR IS UP TO 40KTS. THERE IS SOME WEAK SURFACE
BASED INSTABILITY FORECAST LATE FRIDAY NIGHT...SO CANNOT RULE OUT
THE POSSIBILITY OF A SEVERE STORM MOVING INTO AREAS SOUTH OF INTERSTATE
70 FROM SOUTHWEST KANSAS FRIDAY NIGHT. AFTER MIDNIGHT A MASSIVE
MID LEVEL DRY SLOT WILL OVERSPREAD THE FORECAST AREA...ENDING THE
PRECIPITATION CHANCES FOR ALL BUT THE FAR NORTHWEST CORNER WHICH
COULD RECEIVE SOME LIGHT WRAPAROUND PRECIPITATION THROUGH SATURDAY
MORNING. CLEARING IS EXPECTED BY SATURDAY AFTERNOON FOR THE ENTIRE
AREA.
RIDGING IS FORECAST FOR SUNDAY AND MONDAY WITH ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS. NEXT SHORTWAVE TROUGH WILL
APPROACH THE NORTHERN ROCKIES MONDAY NIGHT AND MOVE ACROSS THE
AREA TUESDAY OR WEDNESDAY. HOWEVER...MOISTURE APPEARS TO BE
LACKING FOR PRECIPITATION CHANCES. ASSOCIATED SURFACE COLD FRONT
COULD PRODUCE WINDY CONDITIONS TUESDAY NIGHT AND WEDNESDAY GIVEN
STRONG UPPER JET IN THE VICINITY. ONLY SLIGHT COOLING IS EXPECTED
WITH FRONTAL PASSAGE GIVEN PACIFIC ORIGIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1142 PM MDT WED OCT 10 2012
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK. WINDS WILL BE TURING FROM THE SOUTH TO THE NORTHWEST
THROUGH THE OVERNIGHT HOURS WITH A COLD FRONT EXPECTED TO MOVE
THROUGH THE TAF SITES AFTER 15Z. WINDS BEHIND THE FRONT WILL
BECOME GUSTY FROM THE NORTH. NO PRECIPITATION IS EXPECTED WITH
THIS FRONT AS ONLY HIGHER CLOUDS ARE EXPECTED. WIND SPEEDS WILL
DECREASE AND LOSE THE GUSTS AFTER SUNSET AROUND 01Z WITH THE WIND
DIRECTION BECOME NORTHEAST.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...024
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1234 AM CDT THU OCT 11 2012
...UPDATE TO AVIATION FOR 06Z TAFS...
.SYNOPSIS...
ISSUED AT 1111 PM CDT WED OCT 10 2012
THE 11.00Z 250 HPA RAOB MAP SHOWED CYCLONIC FLOW OFFSHORE AND ACROSS
CA. THE PEAK JET LEVEL WINDS ASSOCIATED WITH THIS FEATURE WAS AROUND
90 KT EXTENDING ACROSS SOUTHERN CALIFORNIA. DOWNSTREAM, A STRONG NORTHWESTERLY
JET EXTENDED FROM THE CENTRAL CANADIAN PRAIRIE PROVINCES SOUTHEAST TO
THE GREAT LAKES REGION. A JET STREAK OF 140 KT WAS OBSERVED FROM KINL
TO KGRB. AT 500 HPA, OUR NEXT WEATHER SYSTEM WAS OBVIOUS PER GEOPOTENTIAL
HEIGHT ANALYSIS, WIND FIELDS AND SATELLITE WATER VAPOR IMAGERY. THIS
FEATURE WAS A 559 DM LOW LOCATED SSW OF KSFO. AN ASSOCIATED COLD POOL
OF -21 DEG C WAS OBSERVED AT KOAK. OTHERWISE, A BROAD TROUGH WAS LOCATED
ACROSS MUCH OF CENTRAL AND EASTERN CANADA WITH MID LEVEL TEMPERATURES
AS COLD AS -37 DEG C ACROSS CENTRAL MANITOBA. AT 700 HPA, -1 DEG C TEMPS
WERE ASSOCIATED WITH THE WEST COAST LOW. TO THE NORTHEAST, IMPRESSIVE
COLD TEMPERATURES AS LOW AS -19 DEG C WERE OBSERVED ACROSS MANITOBA
AND ONTARIO. THE AIRMASS IN THIS REGION WAS ALSO FAIRLY SATURATED. AT
850 HPA, A WARM AIR ADVECTION PATTERN WAS IN PLACE ACROSS THE CENTRAL
AND SOUTHERN PLAINS WITH MANY UPPER AIR SITES REPORTING SEVERAL DEGREES
OF WARMING BETWEEN THE 10.00Z AND 11.00Z FLIGHTS. SOME MOISTURE ADVECTION
WAS NOTED DOWNSTREAM OF THE AFOREMENTIONED LOW ACROSS SOUTHERN CALIFORNIA.
LOW DEWPOINT DEPRESSIONS - ASSOCIATED WITH STRATUS WAS ALSO NOTED ACROSS
PORTIONS OF TEXAS AND OKLAHOMA. AT THE SFC, A PLETHORA OF FRONTS WERE
NOTED ACROSS THE CONUS...ONE ACROSS MONTANA AND THE DAKOTAS, A STATIONARY
FRONT BUCKED UP ACROSS THE ROCKIES EXTENDING INTO PORTIONS OF TEXAS...AND
A COLD FRONT ACROSS THE DEEP SOUTH EXTENDING NE TO NEW ENGLAND. RICH
BOUNDARY LAYER MOISTURE /MARKED BY DEWPOINTS IN THE UPPER 60S DEG F/
WERE SOUTH OF SAID TWO FRONTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 254 PM CDT WED OCT 10 2012
THE MAIN FORECAST CHALLENGES ARE HIGHS THURSDAY AND THUNDERSTORM
CHANCES LATE THURSDAY AFTERNOON.
AS AN UPPER-LOW TAKES SHAPE OVER THE SOUTHWESTERN UNITED STATES, A
STRONG SURFACE HIGH WILL MOVE SOUTHEASTWARD FROM NORTHERN ALASKA
INTO THE NORTHERN PLAINS IN RESPONSE TO UPPER-LEVEL TROUGHING OVER
THE GREAT LAKES. MID-LEVEL DOWNSLOPE FLOW OVER THE SOUTHERN HIGH PLAINS
AND MEXICO WITH THE SOUTHWESTERN SYSTEM WILL ENCOURAGE LEE TROUGHING
OVER THE SOUTHERN HIGH PLAINS, WITH GULF MOISTURE RETURN INTO THE
SOUTHERN PLAINS. A BAROCLINIC ZONE WILL BECOME ESTABLISHED ACROSS
SOUTHERN KANSAS BY LATE THURSDAY AFTERNOON. GULF MOISTURE CONVERGING
ALONG THIS FRONT MAY WILL LEAD TO THUNDERSTORM DEVELOPMENT BY LATE
AFTERNOON NEAR THE OKLAHOMA STATE LINE. WITH SURFACE BASED CAPE
VALUES AROUND 1000-1500 J/KG AND DECENT SHEAR, SOME HAIL IS POSSIBLE
UP TO THE SIZE OF QUARTERS. HIGHS THURSDAY SHOULD RANGE FROM THE
UPPER 60S AND LOWER 70S ACROSS NORTHERN TREGO AND ELLIS COUNTIES
TO THE UPPER 80S TO EVEN LOWER 90S OVER BARBER AND COMANCHE
COUNTIES.
IN THE NEAR TERM, LOW LEVEL WARM ADVECTION WAS BEGINNING ACROSS
WEST TEXAS THIS AFTERNOON. THE NAM MODEL SOUNDINGS SUGGEST LOW
STRATUS FORMATION BY 09Z AND THEN ERODING BY 15Z WITH DAYTIME
HEATING. LOWS SHOULD BE HELD UP IN THE MID TO HIGH 40S DUE TO THE
SOUTH WIND AT 10 KTS, CLOUD COVER AND INCREASING DEWPOINTS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 353 PM CDT WED OCT 10 2012
THURSDAY NIGHT AND FRIDAY:
SCATTERED CONVECTION SHOULD DEVELOP ALONG THE QUASI-STATIONARY FRONT
DURING THE EVENING HOUR ALONG OR JUST SOUTH OF THE OKLAHOMA BORDER.
WILL MAINTAIN THE 30 TO 40 POPS ACROSS MAINLY THE OKLAHOMA BORDER
COUNTIES WITH A SMALL SLIVER OF 50 POPS ACROSS SOUTHERN BARBER
COUNTY (I.E. KIOWA, KS). UPPER LEVEL FLOW PATTERN WILL STILL BE
MAINLY OUT OF THE WEST WITHIN SHORTWAVE RIDGING SO NORTHWARD ADVANCE
OF STORMS INTO SOUTHWEST/SOUTH CENTRAL KS WILL BE VERY DIFFICULT.
MOST UNSTABLE CAPE OF 1500-2000 J/KG WILL SUPPORT SOME ISOLATED
SEVERE STORMS WITH SOME LARGE HAIL ALONG THE OKLAHOMA BORDER. THE
SURFACE FRONT WILL GRADUALLY LIFT NORTH THROUGH THE DAY FRIDAY WILL
AREAS OF DRIZZLE DEVELOPING IN THE NEAR-SURFACE DEFORMATION AXIS AT
THE ONSET OF LOWER 60S DEWPOINTS. SURFACE TEMPERATURES WILL BE
LOCKED IN THE MID TO UPPER 50S MOST OF THE DAY ACROSS MUCH OF
SOUTHWEST KANSAS...EXCEPT ALONG THE OKLAHOMA BORDER. WILL BE RAMPING
UP THE POPS INTO 40 TO 60 PERCENT CATEGORY SOUTH OF THE ARKANSAS
RIVER LATE IN THE DAY FRIDAY AS UPWARD VERTICAL MOTION INCREASES AND
ISOLATED/SCATTERED CONVECTION BECOMES MORE PROMINENT. WITH THE
SURFACE FRONT AND ATTENDANT SURFACE-BASED CAPE TO THE SOUTH OF
SOUTHWEST KANSAS...MOST AGGRESSIVE CONVECTION WILL STAY ACROSS THE
TEXAS PANHANDLE THROUGH THE AFTERNOON/EARLY EVENING FRIDAY.
FRIDAY NIGHT AND SATURDAY:
THE UPPER LOW AND MID LEVEL POTENTIAL VORTICITY ANOMALY WILL EJECT
NORTHEAST ACROSS KANSAS WHICH WILL SUBSEQUENTLY INCREASE WARM/MOIST
ADVECTION DRAMATICALLY ACROSS WESTERN KANSAS. SURFACE-BASED CAPE
WILL THEN INCREASE ACROSS FAR SOUTHWEST KANSAS FROM 00-03Z WITH
STRONG TO SEVERE CONVECTION FORMING ALONG ADVANCING PACIFIC COLD
FRONT FROM FAR SOUTHEAST COLORADO TO THE NORTHEASTERN TEXAS
PANHANDLE. THESE STORMS WILL MOST LIKELY MOVE TOWARD HIGHWAY 27
DURING THE 00-03Z TIME FRAME...ESPECIALLY JOHNSON TO ELKHART. 0-1KM
SRH WILL BE EXTREMELY HIGH WITH 300-400 M2/S2 AS DYNAMIC LOW LEVEL
JET FORMS OFF THE SURFACE TO THE TUNE OF 50-55 KNOTS. WITH THE
ADVANCE OF 600 TO 1000 J/KG SURFACE BASED CAPE AND STRONG COLD
FRONTAL FORCING...QUASI-LINEAR SEVERE CONVECTION WITH A TENDENCY FOR
LOW LEVEL ROTATION WILL BE A CONCERN...ESPECIALLY 02-05Z TIME FRAME
WEST OF A GARDEN CITY TO LIBERAL LINE. IF SURFACE-BASED INSTABILITY
INCREASES TO AROUND 1200 TO 1500 J/KG FARTHER NORTH INTO SOUTHWEST
KANSAS DURING THE 02-05Z TIME FRAME...THE CONCERN FOR ISOLATED
TORNADOES WILL CERTAINLY BE THERE GIVEN THE INCREDIBLE AMOUNT OF
NEAR-SURFACE SHEAR. IN FACT...JUST A QUICK GLANCE OF THE 18Z NAM
MODEL THAT JUST ROLLED IN AT 2045Z SUGGESTS A MORE OMINOUS SCENARIO
WITH SEVERE STORMS QUITE LIKELY WEST OF A DODGE CITY TO ASHLAND LINE
AS THE SURFACE WARM FRONT RACES NORTH. WILL CARRY 50 TO 60 POPS
FARTHER EAST BEYOND 06Z ACROSS PORTIONS OF SOUTHWEST, CENTRAL, SOUTH
CENTRAL KANSAS AS STRONG/SEVERE STORMS CONTINUE TO MOVE NORTHEAST IN
ADVANCE OF THE PACIFIC COLD FRONT. STORMS SHOULD EXIT THE SOUTHWEST
KANSAS REGION BEFORE DAYBREAK WITH DRIER AIRMASS ADVECTING IN FROM
COLORADO DURING THE MID TO LATE MORNING HOURS. AS DEWPOINTS FALL
RAPIDLY INTO THE LOWER 30S AND TEMPERATURES RISE INTO THE MID TO
UPPER 70S BY AFTERNOON...CRITICAL OR NEAR CRITICAL FIRE WEATHER
CONDITIONS WILL BE POSSIBLE AS WEST-SOUTHWEST WINDS OF 20 TO 30 MPH
WILL BE LIKELY.
SUNDAY THROUGH WEDNESDAY:
A WARM AND DRY SENSIBLE WEATHER SETUP IS EXPECTED AS SUSTAINED
DOWNSLOPE MID-LEVEL FLOW FROM THE WEST NORTHWEST WILL PREVAIL.
TEMPERATURES SUNDAY THROUGH TUESDAY WILL BE ABOVE AVERAGE WITH HIGHS
IN THE LOWER 80S AND LOWS IN THE LOWER TO MID 50S. A VERY STRONG
UPPER LEVEL JET WILL ENTER THE PACIFIC NORTHWEST EARLY NEXT WEEK
WITH A FAIRLY POTENT SHORTWAVE TROUGH MOVING ACROSS THE FAR NORTHERN
PLAINS/SOUTHERN CANADA PRAIRIES. COLD FRONT FROM THIS SYSTEM WILL
LIKELY PENETRATE THE CENTRAL PLAINS AROUND EARLY WEDNESDAY OF NEXT
WEEK WITH COOLER TEMPERATURES BACK TO TYPICAL OCTOBER
NUMBERS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1234 AM CDT THU OCT 11 2012
MAIN CONCERN FOR 06Z TAFS IS CIGS. LOW PRESSURE LOCATED ACROSS THE LEE
OF THE ROCKIES WILL KEEP SSE WINDS IN THE FORECAST THROUGH THE OVERNIGHT
HOURS. LOW STRATUS HAS BEGUN TO CREEP CLOSER WITH PRATT REPORTING CLOSE
TO MVFR CIGS. AN INSPECTION OF PLAN VIEW RH PROGS WITHIN THE BOUNDARY
LAYER SHOW NEAR SATURATION, HOWEVER, INSPECTING BUFKIT FORECAST SOUNDINGS
SHOW LESS OF PROBLEM THAN WHAT THE HRRR IS SUGGESTING (NAMELY VIS).
ANYWAY, WILL PUT MVFR CIGS FOR KGCK/KDDC THIS MORNING. CONFIDENCE IS
LOWER FOR MVFR CIGS AT KHYS DUE TO A DRIER PROFILE. BY MID MORNING,
A DOWNSLOPE SW IS EXPECTED AHEAD OF A COLD FRONT WHICH SHOULD ALLOW
FOR VFR CIGS. THIS FRONT WILL TRAVERSE ACROSS MUCH OF THE REGION BY
THE AFTERNOON. SECOND CONCERN IS CONVECTION LATE THIS EVENING, HOWEVER,
THIS ACTIVITY SHOULD REMAIN SOUTH OF THE TERMINALS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 51 62 61 78 / 20 40 60 20
GCK 47 59 58 75 / 10 50 70 10
EHA 50 63 51 76 / 30 70 70 0
LBL 51 65 59 78 / 30 70 70 10
HYS 45 58 58 76 / 10 30 60 20
P28 58 68 63 79 / 50 60 50 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...FINCH
LONG TERM...UMSCHEID
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS CARIBOU ME
949 AM EDT THU OCT 11 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE EAST OF THE AREA TODAY AS HIGH
PRESSURE BUILDS SOUTH OF THE REGION. WEAK FAST MOVING LOW PRESSURE WILL
MOVE ACROSS FAR NORTHERN MAINE LATE TONIGHT. COLD HIGH PRESSURE
WILL FOLLOW FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE: ADJUSTED THE POPS TO REFLECT THE LATEST RADAR TRENDS
W/SCATTERED SHOWERS MOVING ACROSS THE NORTHERN PORTION OF THE
REGION THIS MORNING. INCREASED THE PERCENTAGES AND AREAL COVERAGE
FOR LATE MORNING INTO THE AFTERNOON. INCLUDED A BRIEF PERIOD OF SNOW
FOR THIS UPDATE W/VERY COLD AIR ALOFT. LITTLE OR NO ACCUMULATION IS
EXPECTED.
UPPER TROF W/STRONG VORTICITY ADVECTION WILL AID IN LIFT.
LATEST RUC SOUNDINGS SHOW LAPSE RATES TO STEEPEN LATER THIS MORNING
INTO THE AFTERNOON W/INVERTED V IN THE LLVLS. THIS COMBINED W/CAA
WILL ALLOW FOR SOME STRONGER WIND GUSTS INTO THE AFTERNOON.
THEREFORE, INCREASED THE GUST POTENTIAL UP 5-10 KTS EVERYWHERE.
COULD VERY WELL SEE GUSTS HIT 40+MPH OVER OPEN AND HIGHER TERRAIN
AREAS. TWEAKED DEWPOINTS USING THE LATEST LAMP GUIDANCE SHOWING
READINGS TO DROP THROUGH THE DAY.
SEE MARINE SECTION BELOW.
PREVIOUS DISCUSSION...
STRONG CAA EXPECTED TO OVERSPREAD THE FA TODAY ON BRISK W TO NW
WNDS AS RIDGE OF CANADIAN HIGH PRES BEGINS TO BUILD INTO THE
REGION. MAX TEMPS LIKELY TO BE REACHED BY LATE AM/ERLY AFTN
BEFORE STEADYING OUT OR EVN FALLING A BIT THIS AFTN. CLOUDS AND
WNDS SHOULD DECREASE QUICKLY BY MID TO LATE AFTN AS THE RIDGE AXIS
IS EXPECTED TO QUICKLY CREST THE AREA BY THIS EVE AHEAD OF A FAST
MVG BUT WEAK SFC LOW PRES SYSTEM WHICH MODEL CONSENSUS HAS
CROSSING FAR NRN MAINE BY 12Z FRI. WEAK WAA AHEAD OF THIS SYSTEM
WILL ALLOW PRECIP TO OVERSPREAD FAR N AND NW AREAS BEFORE MDNGT
AND REACH NERN AREAS 06-08Z. BL TEMPS/CRITICAL THCKNS VALS SUGGEST
BEST CHC FOR ANY SNOW REMAINS ACROSS THE FAR N AND NW WHERE AN
INCH OR SO IS PSBL. WILL CONT CAT TO LIKELY POPS FAR NRN AREAS W/CHC
POPS CENTRAL AND S. OVERALL EXPECT THIS UPCOMING EVENT TO PRODUCE
ONLY LGT QPF AMOUNTS W/ PRECIP MAXES BLO .25 INCHES EXPECTED...
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
CLIPPER-TYPE LOW PRESSURE WILL BE EXITING FROM MAINE INTO NEW
BRUNSWICK LATE FRIDAY MORNING, WITH HIGH PRESSURE QUICKLY BEGINNING
TO BUILD OVER THE NORTHEAST CONUS THEREAFTER. SHOWERS WILL LINGER
THROUGH THE MORNING HOURS, BUT WILL QUICKLY END BY EARLY AFTERNOON.
EARLY MORNING TEMPERATURES WILL BE COLD ENOUGH FOR SNOW OR A
RAIN/SNOW MIX, BUT ANTICIPATE LITTLE TO NO ACCUMULATION, ESPECIALLY
ONCE THE SUN COMES UP. CLOUDS WILL LINGER ACROSS THE NORTHWESTERN
PORTIONS OF THE STATE, BUT MOST AREAS SHOULD SEE SUNSHINE BEGIN TO
BREAK THROUGH IN THE AFTERNOON, ESPECIALLY DOWNEAST. HOWEVER, EVEN
WITH SUN, IT WILL FEEL VERY CHILLY FRIDAY AS BRISK NORTHWEST WINDS
DEVELOP IN THE TIGHT PRESSURE GRADIENT BETWEEN THE RETREATING LOW
AND THE ADVANCING HIGH. WINDS OF 15 TO 25 MPH WITH GUSTS TO 30 MPH
CAN BE EXPECTED. TEMPERATURES WILL RANGE FROM AROUND 40 IN THE NORTH
WOODS TO AROUND 50 DOWNEAST.
HIGH PRESSURE WILL SLOWLY BUILD EASTWARD FRIDAY NIGHT INTO SATURDAY,
EVENTUALLY MOVING OFF THE MID ATLANTIC COAST AND OUT TO SEA. AS
SUCH, EXPECT CLEARING SKIES FOR FRIDAY NIGHT INTO SATURDAY MORNING.
OVERNIGHT TEMPERATURES WILL BE QUITE COLD WITH EVERYONE GETTING DOWN
INTO THE 20S. WINDS WILL SUBSIDE A BIT FROM FRIDAY AFTERNOON, BUT
SHOULD REMAIN HIGH ENOUGH TO PRECLUDE ANY FOG DEVELOPMENT OUTSIDE OF
THE DEEPER RIVER VALLEYS. SATURDAY WILL START OUT MOSTLY SUNNY, BUT
EXPECT STRATOCUMULUS TO ARISE BY LATE MORNING AS MIXING OCCURS.
WINDS WILL ONCE AGAIN BE ON THE GUSTY SIDE, THOUGH NOT AS STRONG AS
ON FRIDAY. TEMPERATURES ON SATURDAY WILL BE SIMILAR TO THOSE ON
FRIDAY, TOPPING OUT IN THE 40S IN MOST SPOTS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE UNSETTLED PATTERN CONTINUES THROUGH THE LONG TERM. WE START OFF
WITH A FRONTAL SYSTEM SET TO MOVE ACROSS THE GREAT LAKES SATURDAY
NIGHT INTO SUNDAY, WITH THE LEADING WARM FRONT MOVING ACROSS MAINE
DURING THAT TIME FRAME. THE LOW WILL THEN TRAVERSE EASTWARD
THROUGH SOUTHERN QUEBEC, DRAGGING ITS COLD FRONT THROUGH THE
FORECAST AREA MONDAY AFTERNOON AND NIGHT. AS SUCH, SUNDAY AND
MONDAY WILL BE WET, WITH A MIX OF RAIN AND SNOW POSSIBLE OVER THE
NORTH LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING. WRAP AROUND
SHOWERS CONTINUE INTO EARLY TUESDAY, THEN CONDITIONS WILL DRY OUT
AS HIGH PRESSURE BUILDS OVER THE AREA. THIS FEATURE WILL KEEP FAIR
WEATHER IN THE STATE TUESDAY AFTERNOON THROUGH WEDNESDAY. MONDAY
WILL BE THE WARMEST DAY OF THE PERIOD, THOUGH IT DEPENDS ON HOW
LONG THE AREA STAYS IN THE WARM SECTOR BEFORE THE COLD FRONT
PUSHES THROUGH. OTHERWISE, TEMPERATURES WILL BE NEAR SEASONAL
NORMAL THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
NEAR TERM: MAINLY VFR CONDS WILL PREVAIL TODAY INTO TNGT THO CAN
NOT RULE OUT SOME PATCHY MVFR ACROSS OUR NRN TAF SITES THIS AM IN
SOME POST-FRONTAL SC. MFR TO PSBL IFR CONDS ARE PSBL ACROSS THE
NRN TAF SITES LATE TNGT/ERLY FRI AS A FAST MVG LOW PRES SYSTEM
CROSSES FAR NRN AREAS W/ SOME LGT RAIN OR WET SNOW.
SHORT TERM: MVFR/OCCASIONAL IFR EXPECTED THROUGH 15Z FRIDAY DUE TO
LOW CEILINGS AND PRECIPITATION. RAIN MAY MIX WITH SNOW EARLY AT THE
NORTHERN TERMINALS. CONDITIONS IMPROVE FRIDAY AFTERNOON WITH VFR
CONDITIONS EXPECTED THROUGH SATURDAY. PRECIPITATION RETURNS SATURDAY
NIGHT AND CONTINUES THROUGH MONDAY. EXPECT MAINLY MVFR CONDITIONS
DURING THIS PERIOD. THE EXCEPTIONS WILL BE EARLY SUNDAY MORNING WHEN
SNOW MAY DROP THINGS TO IFR AT THE NORTHERN SITES. OCCASIONAL IFR
CEILINGS ARE ALSO POSSIBLE SUNDAY AND SUNDAY NIGHT, WHEN THE
STEADIEST RAIN IS EXPECTED.
&&
.MARINE...
NEAR TERM:
UPDATE...UPGRADED THE HEADLINE TO GLW AS WINDS ARE CREEPING UP
CLOSE TO 34 KTS. 44027 ALREADY AT 33 KTS AT 9 AM. THINKING IS THAT
GUSTS WILL HIT 35 KTS THROUGH THE AFTERNOON INCLUDING THE INTRA-
COASTAL WATERS. INVERTED V TYPE SOUNDINGS SHOWING STRONG
INSTABILITY AND CAA WILL ALLOW FOR STRONGER WINDS ALOFT TO MIX
DOWN TO THE BLYR. SCA CONDITIONS EXPECTED TONIGHT W/A BRIEF
REPRIEVE IN THE WINDS BEFORE THEY COME BACK UP ON FRIDAY.
SHORT TERM: THE SMALL CRAFT ADVISORY HAS BEEN EXTENDED THROUGH BY
FRIDAY NIGHT SINCE WINDS LOOK TO INCREASE AHEAD OF A CLIPPER-TYPE
LOW PRESSURE SYSTEM. WINDS OF 20 TO 30 KT AND WAVES 5 TO 7 FT CAN
BE EXPECTED TO LAST INTO FRIDAY EVENING. CONDITIONS WILL BEGIN TO
IMPROVE BY AROUND MIDNIGHT AS HIGH PRESSURE BEGINS TO BUILD OVER
THE REGION. HOWEVER, GUSTY WINDS AROUND 20 KT WILL STILL BE
POSSIBLE THROUGH SATURDAY MORNING.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT/KHW
SHORT TERM...HASTINGS
LONG TERM...HASTINGS
AVIATION...HEWITT/KHW
MARINE...HEWITT/KHW/HASTINGS
AREA FORECAST DISCUSSION
NWS GRAY ME
944 AM EDT THU OCT 11 2012
.SYNOPSIS...
GUSTY WEST WINDS ARE EXPECTED BEHIND THE FRONT TODAY WITH
MOSTLY SUNNY SKIES OUTSIDE THE MOUNTAINS. ANOTHER COLD FRONT WILL
CROSS THE REGION FRIDAY MORNING...BRINGING VERY COLD
TEMPERATURES OVERNIGHT INTO SATURDAY. A HIGH BUILDS IN FOR THE
START OF THE WEEKEND BEFORE ANOTHER LOW MOVES UP THE SAINT
LAWRENCE VALLEY ON SUNDAY NIGHT WITH WIDESPREAD RAIN SHOWERS AND
MODERATE TEMPERATURES EXPECTED THROUGH THE START OF NEXT WEEK.
&&
.NEAR TERM /TODAY/...
945 AM UPDATE...HAVE UPDATED TO ADJUST POPS AND SKY COVER TO
REFLECT CURRENT THINKING. SHOULD BE A SUNNY DAY ON THE DOWNSLOPING
SIDE OF THE MOUNTAINS. BUT IN UPSLOPE AREAS SOME RAIN/SNOW SHOWERS
WILL CONTINUE THROUGH THE REMAINDER OF THE MORNING BEFORE
GRADUALLY DISSIPATING. NO OTHER SIGNIFICANT CHANGES WERE MADE.
UPDATE... HAVE UPDATED GRIDS BASED ON LATEST RADAR AND INFRARED
SATELLITE IMAGERY. UPSLOPE SNOW SHOWERS CONTINUE IN THE WESTERN
MOUNTAINS OF MAINE AND NORTHERNMOST NEW HAMPSHIRE AT THIS HOUR.
LATEST HRRR MODEL RUN DEPICTING A FEW MORE OF THESE FAST MOVING
SPRINKLES/SHOWERS CONTINUING UNTIL THIS AFTERNOON.
MINOR ADJUSTMENTS MADE TO WIND/CLOUD GRIDS. OTHERWISE FORECAST ON
TRACK.
PREVIOUS DISCUSSION...
GUSTY WEST WINDS WILL DOMINATE OUR WEATHER CONDITIONS TODAY AS THE
PRESSURE GRADIENT REMAINS IN PLACE TODAY WITH COLD AIR ADVECTION.
DOWNSLOPING WILL OCCUR OUTSIDE THE MOUNTAINS...ALLOWING FOR SUNSHINE
AND TEMPS TO CLIMB THRU THE UPPER 50S TO NEAR 60. MUCH COOLER IN
THE MOUNTAINS WITH CLOUD COVER AND ISOLATED SHOWERS/SPRINKLES. LOOK
FOR HIGHS ONLY IN THE UPPER 40S ACROSS THE HIGHER TERRAIN. USED A
BLEND OF MAV/MET MOS FOR MAX TEMPERATURES TODAY.
&&
.SHORT TERM /TONIGHT AND FRIDAY/...
MID AND HIGH LEVEL MOISTURE WILL ALREADY BE ADVECTING QUICKLY INTO
THE REGION BY THIS EVENING ACROSS MUCH OF MAINE AND NEW HAMPSHIRE.
YET ANOTHER FRONT WILL BRING THE THREAT OF SHOWERS AND EVEN A FEW
SNOW SHOWERS ABOVE 2500 FEET. ANY LIGHT PRECIPITATION WILL MOSTLY
BE CONFINED TO NORTHERN AREAS.
GUSTY WINDS AND ANOTHER SHOT OF COLD AIR WILL ENTER THE REGION ON
FRIDAY. LOOK FOR HIGH TEMPERATURES TO OCCUR AROUND NOONTIME...BEFORE
SETTLING BACK. A STRONG RIDGE OF HIGH PRESSURE WILL CONTINUE TO
BUILD TOWARDS NEW ENGLAND THRU THE DAY. THIS SETS THE STAGE FOR
THE COLDEST AIR OF THE SEASON AND WIDESPREAD FREEZES IN THE
EXTENDED PORTION OF THE FORECAST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
WE BEGIN THE PERIOD WITH AN IMPULSE EXITING THE REGION...AND
IN ITS WAKE INTRODUCING AN EARLY TASTE OF LATE FALL CHILL TO THE
REGION. SURFACE HIGH PRESSURE WITH DRY AIR AND BELOW NORMAL
TEMPERATURES WILL BUILD ACROSS THE AREA FOR FRIDAY NIGHT AND
SATURDAY. A SHORT WAVE ARRIVES FROM THE UPPER MIDWEST FOR SATURDAY
NIGHT AND SUNDAY. AN ASSOCIATED SURFACE LOW TRACKS FROM THE UPPER
GREAT LAKES ON SUNDAY TO THE SAINT LAWRENCE VALLEY ON MONDAY
PULLING ITS ASSOCIATED WARM AND COLD FRONTS ACROSS THE AREA. THE
WARM FRONT MAY PRODUCE SOME LIGHT SNOW ACROSS THE HIGH TERRAIN
EARLY SUNDAY...AS THE FORECAST PROFILES THERE ARE INITIALLY COLD
ENOUGH FOR SNOW. ABOVE NORMAL TEMPERATURES THEN FOLLOW THE WARM
FRONT IN SOUTHERLY FLOW FOR BOTH SUNDAY AND MONDAY...WITH COLD
FRONT TO CROSS THE AREA LATE MONDAY FOLLOWED BY A RETURN TO MORE
AVERAGE TEMPERATURES FOR THE REMAINDER OF THE PERIOD. HIGH
PRESSURE WILL BUILD ACROSS THE REGION FOR THE MID WEEK PERIOD.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
SHORT TERM...
WILL SEE VFR CONDITIONS TODAY WITH WESTERLY WINDS GUSTING FROM 20
TO 25 KT. MAY SEE CONDITIONS LOWER AGAIN TONIGHT AS THE NEXT WAVE
APPROACHES.
LONG TERM...
SUN - MON...AREAS OF MVFR IN SHOWERS.
&&
.MARINE...
SHORT TERM...
THE SMALL CRAFT ADVISORY CONTINUES THROUGH THURSDAY AFTERNOON AS
WESTERLY WINDS BEHIND A COLD FRONT ARE EXPECTED TO GUST FROM 25 TO
30 KT WITH A FEW GUSTS TO 35 KT POSSIBLE MAINLY DURING THE DAY
THURSDAY. HAVE ALSO INCLUDED THE BAYS IN THE SMALL CRAFT ADVISORY
AS WINDS WILL BE GUSTING IN THE BAYS AS WELL.
SOUTHWEST FLOW PICKS UP TONIGHT...WITH SMALL CRAFT ADVISORY LEVEL
CONDITIONS POSSIBLE OVER THE OUTER WATERS. WILL NOT ISSUE A NEW
ADVISORY AT THIS TIME AND WILL ALLOW THE DAY SHIFT TO TREAT THIS
SEPARATE WIND/WAVE EVENT LATER TODAY. ADVISORY LEVEL WINDS LIKELY
ON FRIDAY AS WELL IN STRONG COLD AIR ADVECTION AND INCREASING
GRADIENT.
LONG TERM...
FRI NIGHT...A SMALL CRAFT FOR WINDS AND SEAS IS POSSIBLE.
SUN - MON...A SMALL CRAFT FOR WINDS AND SEAS IS POSSIBLE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
ANZ150>154.
&&
$$
UPDATE...KIMBLE
AREA FORECAST DISCUSSION
NWS GRAY ME
707 AM EDT THU OCT 11 2012
.SYNOPSIS...
GUSTY WEST WINDS ARE EXPECTED BEHIND THE FRONT TODAY WITH
INCREASING SUNSHINE. ANOTHER COLD FRONT WILL CROSS THE REGION FRIDAY
MORNING...BRINGING VERY COLD TEMPERATURES OVERNIGHT INTO
SATURDAY. A HIGH BUILDS IN FOR THE START OF THE WEEKEND BEFORE
ANOTHER LOW MOVES UP THE SAINT LAWRENCE VALLEY ON SUNDAY NIGHT
WITH WIDESPREAD RAIN SHOWERS AND MODERATE TEMPERATURES EXPECTED
THROUGH THE START OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE UPDATED GRIDS BASED ON LATEST RADAR AND IR STLT IMAGERY.
UPSLOPE -SHSN CONTS IN THE WRN MTNS OF ME AND NRNMST NH AT THIS
HR. LATEST HRRR MODEL RUN DEPICTING A FEW MORE OF THESE FAST
MOVING SPRINKLES/SHOWERS CONTG UNTIL THIS AFTN.
MINOR ADJUSTMENTS MADE TO WIND/CLOUD GRIDS. OTRW FCST ON TRACK.
PREV DISC...
GUSTY WESTERLY WINDS WILL DOMINATE OUR WEATHER CONDS TODAY
AS THE PRES GRADIENT REMAINS IN PLACE TODAY WITH CAA. DOWNSLOPING
WILL OCCUR OUTSIDE THE MTNS...ALLOWING FOR SUNSHINE AND TEMPS TO
CLIMB THRU THE UPPER 50S TO NEAR 60. MUCH COOLER IN THE MTNS WITH
CLOUD COVER AND ISOLD -SHRA/SPRINKLES. LOOK FOR HIGHS ONLY IN THE
UPPER 40S ACROSS THE HIGHER TRRN. USED A BLEND OF MAV/MET MOS FOR
MAX TEMPS TODAY.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
MID AND HIGH LEVEL MOISTR WILL ALREADY BE ADVECTING QUICKLY INTO
THE REGION BY THIS EVENING ACROSS MUCH OF MAINE AND NEW HAMPSHIRE.
YET ANOTHER FRONT WILL BRING THE THREAT OF -SHRA AND EVEN A FEW
-SHSN ABOVE 2500 FEET. ANY LIGHT PCPN WILL MOSTLY BE CONFINED TO
NRN AREAS.
GUSTY WINDS AND ANOTHER SHOT OF COLD AIR WILL ENTER THE REGION ON
FRIDAY. LOOK FOR HIGH TEMPS TO OCCUR AROUND NOONTIME...BEFORE
SETTLING BACK. A STRONG RIDGE OF HIGH PRES WILL CONT TO BUILD
TOWARDS NEW ENGLAND THRU THE DAY. THIS SETS THE STAGE FOR THE
COLDEST AIR OF THE SEASON AND WIDESPREAD FREEZES IN THE EXTENDED
PTN OF THE FCST.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
WE BEGIN THE PERIOD WITH AN IMPULSE EXITING THE REGION...AND
IN ITS WAKE INTRODUCING AN EARLY TASTE OF LATE FALL CHILL TO THE
REGION. SURFACE HIGH PRESSURE WITH DRY AIR AND BELOW NORMAL
TEMPERATURES WILL BUILD ACROSS THE AREA FOR FRIDAY NIGHT AND
SATURDAY. A SHORT WAVE ARRIVES FROM THE UPPER MIDWEST FOR SATURDAY
NIGHT AND SUNDAY. AN ASSOCIATED SURFACE LOW TRACKS FROM THE UPPER
GREAT LAKES ON SUNDAY TO THE SAINT LAWRENCE VALLEY ON MONDAY
PULLING ITS ASSOCIATED WARM AND COLD FRONTS ACROSS THE AREA. THE
WARM FRONT MAY PRODUCE SOME LIGHT SNOW ACROSS THE HIGH TERRAIN
EARLY SUNDAY...AS THE FORECAST PROFILES THERE ARE INITIALLY COLD
ENOUGH FOR SNOW. ABOVE NORMAL TEMPERATURES THEN FOLLOW THE WARM
FRONT IN SOUTHERLY FLOW FOR BOTH SUNDAY AND MONDAY...WITH COLD
FRONT TO CROSS THE AREA LATE MONDAY FOLLOWED BY A RETURN TO MORE
AVERAGE TEMPERATURES FOR THE REMAINDER OF THE PERIOD. HIGH
PRESSURE WILL BUILD ACROSS THE REGION FOR THE MID WEEK PERIOD.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
SHORT TERM...
WILL SEE VFR CONDITIONS TODAY WITH WESTERLY WINDS GUSTING FROM 20
TO 25 KT. MAY SEE CONDITIONS LOWER AGAIN TONIGHT AS THE NEXT WAVE
APPROACHES.
LONG TERM...
SUN - MON...AREAS OF MVFR IN SHOWERS.
&&
.MARINE...
SHORT TERM...
THE SMALL CRAFT ADVISORY CONTS THROUGH THURSDAY AFTERNOON AS
WESTERLY WINDS BEHIND A COLD FRONT ARE EXPECTED TO GUST FROM 25 TO
30 KT WITH A FEW GUSTS TO 35 KT POSSIBLE MAINLY DURING THE DAY
THURSDAY. HAVE ALSO INCLUDED THE BAYS IN THE SMALL CRAFT ADVISORY
AS WINDS WILL BE GUSTING IN THE BAYS AS WELL.
SW FLOW PICKS UP TONIGHT...WITH SCA CONDS PSBL OVER THE OUTER
WATERS. WILL NOT ISSUE SCA AT THIS TIME AND WILL ALLOW THE DAY
SHIFT TO TREAT THIS SEPARATE WIND/WAVE EVENT LATER TODAY. SCA
WINDS LIKELY ON FRI AS WELL IN STG CAA AND INCREASING GRADIENT.
LONG TERM...
FRI NIGHT...A SMALL CRAFT FOR WINDS AND SEAS IS POSSIBLE.
SUN - MON...A SMALL CRAFT FOR WINDS AND SEAS IS POSSIBLE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
ANZ150>154.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
618 AM EDT THU OCT 11 2012
.SYNOPSIS...
CHILLY EARLY MORNING TEMPERATURES WILL GIVE WAY TO PLENTY OF
SUNSHINE TODAY AS HIGH PRESSURE BUILDS INTO OUR AREA. A WEAK COLD
FRONT WILL CROSS THE REGION TONIGHT INTO FRIDAY MORNING. HIGH
PRESSURE WILL THEN BUILD IN FOR THE EARLY PART OF THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
600 AM UPDATE...
TWEAKED TEMPERATURES FOR EARLY MORNING AND CLEARED OUT CLOUDS
THROUGH MUCH OF NORTH. WAITED FOR CLOUDS TO DEPART NORTH SECTIONS
IN HOPES OF TEMPERATURES FALLING INTO LOWER 30S FOR DISCONTINUING
FREEZE PROGRAM. DUJ AND IDI BOTH DROPPED TO 34. WILL CONTINUE TO
MONITOR.
PREVIOUS DISCUSSION FOLLOWS... HIGH PRESSURE WILL DOMINATE TODAY
WITH DRY WEATHER AND MODERATING TEMPERATURES. HIGH TEMPERATURES
WILL RECOVER TO NEAR 60 BY THIS AFTERNOON. A WEAK COLD FRONT WILL
PUSH ACROSS THE DISTRICT LATE TONIGHT INTO FRIDAY
MORNING...BRINGING JUST A CHANCE OF SHOWERS DUE TO A LACK OF
MOISTURE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE COLD FRONT WILL PUSH EAST OF THE DISTRICT BY MID DAY FRIDAY
ENDING THE RISK OF SHOWERS BY AFTERNOON. ANOTHER COLD NIGHT IS
ANTICIPATED FRIDAY NIGHT BEFORE WARM ADVECTION RESUMES IN ADVANCE OF
A STRONGER COLD FRONT ACROSS THE MIDWEST. THE SHORT WAVE RIDGE IN THE
AMPLIFIED FLOW SUPPORTS A WARMER...AND STILL DRY SATURDAY...ALTHOUGH
SLIGHT CHC POPS WERE INCLUDED OVER NRN COUNTIES AS MDLS...WITH GFS
PROJECTING A MORE SRN EXTENT...SPAWN PCPN ALNG THE ADVNG LOWS WARM
FRONT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
LOW PRES IS STILL PROJECTED ACRS THE GREAT LAKES ON SUNDAY...AS IS
THE SYSTEMS CDFNT ACRS THE UPR OH REGION. AS IN PREVIOUS
SYSTEMS...THE BTR MID LVL SPPRT AND MSTR IS FORECAST N OF THE
AREA...HENCE POPS WERE CONFINED TO THE CHC CATEGORY...WITH THE
HIGHER NMBRS DRAWN FM PIT NWD.
THEREAFTER...CONFIDENCE IN THE LONG TERM FORECAST DROPS AS MDLS
DIVERGE IN MAGNITUDE AND TIMING OF SHRTWVS WITHIN A STILL-
PROGRESSIVE PTN. FORECAST IS THUS CLOSE TO HPC GUIDANCE IN
DEPICTIONS OF NR NORMAL TEMPS AND SLGT CHC...TO CHC POPS.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
STRATO-CU STILL HANGING ACROSS NORTHERN TERMINALS IN NW 850 FLOW
AND 850 TEMPERATURES NEAR MINUS 4C. 850 FLOW GOES ZONAL EARLY THURSDAY
AND STRATO-CU SHOULD BE ON THE WANE. CURRENTLY MORE STRATO-CU
UPSTREAM BUT HRRR AND GFS SUGGESTING AS FLOW GOES ZONAL TO
SOUTHWEST...CLOUDS NOW OVER WI ERODE AND GENERALLY LIFT NORTHWARD.
WITH GENERAL FLOW GOING SOUTHWEST TODAY... WILL JUST GO WITH
SCT050 CU AND CLEAR IT OUT TOWARD SUNSET THIS EVENING BEFORE
BRINGING IN AC AND CI TOWARD 06Z FRIDAY. WINDS DECREASING ACROSS
CWA WITH DUJ ONLY TERMINAL STILL GUSTING AT THIS TIME. EXPECT
CONTINUED DIMINISHING OVERNIGHT.
.OUTLOOK.../THURSDAY NIGHT THROUGH SUNDAY/...
WEAK FRONT APPROACHES OVERNIGHT THURSDAY INTO FRIDAY WITH MID DECK
AND CI BUT EXPECT VFR CONDITIONS. HIGH PRESSURE THEN BUILDS ACROSS
REGION THROUGH SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR PAZ016-022-023-
031-073-075.
WV...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR WVZ004-012-021-
022.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
340 AM EDT THU OCT 11 2012
.SYNOPSIS...
HIGH PRESSURE PUSHING INTO THE DISTRICT THIS MORNING WITH
CLEAR SKIES AND TEMPERATURES DROPPING BELOW FREEZING ACROSS MUCH
OF THE AREA. DRY WEATHER CAN BE EXPECTED TODAY...BUT A COLD FRONT
WILL CROSS THE AREA THURSDAY NIGHT INTO FRIDAY MORNING. HIGH
PRESSURE WILL BUILD IN FOR THE EARLY PART OF THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL DOMINATE TODAY WITH DRY WEATHER AND MODERATING
TEMPERATURES. HIGH TEMPERATURES WILL RECOVER TO NEAR 60 BY THIS
AFTERNOON. A WEAK COLD FRONT WILL PUSH ACROSS THE DISTRICT LATE TONIGHT
INTO FRIDAY MORNING...BRINGING JUST A CHANCE OF SHOWERS DUE TO A
LACK OF MOISTURE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE COLD FRONT WILL PUSH EAST OF THE DISTRICT BY MID DAY FRIDAY
ENDING THE RISK OF SHOWERS BY AFTERNOON. ANOTHER COLD NIGHT IS
ANTICIPATED FRIDAY NIGHT BEFORE WARM ADVECTION RESUMES IN ADVANCE OF
A STRONGER COLD FRONT ACROSS THE MIDWEST. THE SHORT WAVE RIDGE IN THE
AMPLIFIED FLOW SUPPORTS A WARMER...AND STILL DRY SATURDAY...ALTHOUGH
SLIGHT CHC POPS WERE INCLUDED OVER NRN COUNTIES AS MDLS...WITH GFS
PROJECTING A MORE SRN EXTENT...SPAWN PCPN ALNG THE ADVNG LOWS WARM
FRONT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
LOW PRES IS STILL PROJECTED ACRS THE GREAT LAKES ON SUNDAY...AS IS
THE SYSTEMS CDFNT ACRS THE UPR OH REGION. AS IN PREVIOUS
SYSTEMS...THE BTR MID LVL SPPRT AND MSTR IS FORECAST N OF THE
AREA...HENCE POPS WERE CONFINED TO THE CHC CATEGORY...WITH THE
HIGHER NMBRS DRAWN FM PIT NWD.
THEREAFTER...CONFIDENCE IN THE LONG TERM FORECAST DROPS AS MDLS
DIVERGE IN MAGNITUDE AND TIMING OF SHRTWVS WITHIN A STILL-
PROGRESSIVE PTN. FORECAST IS THUS CLOSE TO HPC GUIDANCE IN
DEPICTIONS OF NR NORMAL TEMPS AND SLGT CHC...TO CHC POPS.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
STRATO-CU STILL HANGING ACROSS NORTHERN TERMINALS IN NW 850 FLOW
AND 850 TEMPERATURES NEAR MINUS 4C. 850 FLOW GOES ZONAL EARLY THURSDAY
AND STRATO-CU SHOULD BE ON THE WANE. CURRENTLY MORE STRATO-CU
UPSTREAM BUT HRRR AND GFS SUGGESTING AS FLOW GOES ZONAL TO
SOUTHWEST...CLOUDS NOW OVER WI ERODE AND GENERALLY LIFT NORTHWARD.
WITH GENERAL FLOW GOING SOUTHWEST TODAY... WILL JUST GO WITH
SCT050 CU AND CLEAR IT OUT TOWARD SUNSET THIS EVENING BEFORE
BRINGING IN AC AND CI TOWARD 06Z FRIDAY. WINDS DECREASING ACROSS
CWA WITH DUJ ONLY TERMINAL STILL GUSTING AT THIS TIME. EXPECT
CONTINUED DIMINISHING OVERNIGHT.
.OUTLOOK.../THURSDAY NIGHT THROUGH SUNDAY/...
WEAK FRONT APPROACHES OVERNIGHT THURSDAY INTO FRIDAY WITH MID DECK
AND CI BUT EXPECT VFR CONDITIONS. HIGH PRESSURE THEN BUILDS ACROSS
REGION THROUGH SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR PAZ016-022-023-
031-073-075.
WV...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR WVZ004-012-021-
022.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
151 AM EDT THU OCT 11 2012
.SYNOPSIS...
HIGH PRESSURE WILL APPROACH FROM THE SOUTHWEST OVERNIGHT ALLOWING
CLEARING SKIES AND TEMPERATURES DROPPING BELOW FREEZING ACROSS
MUCH OF THE AREA. THE NEXT COLD FRONT WILL CROSS THE AREA THURSDAY
NIGHT INTO FRIDAY MORNING. HIGH PRESSURE WILL BUILD IN FOR THE
EARLY PART OF THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
06Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO INCREASE
THE COVERAGE OF LAKE EFFECT STRATOCU ACROSS NORTHWEST PA.
THE LATEST RAP MID- LEVEL ANALYSIS INDICATES A BROAD 500MB TROUGH
CENTERED ACROSS THE EASTERN GREAT LAKES WITH THE UPPER OHIO VALLEY
IN A WEAK CYCLONIC TO NEAR ZONAL FLOW AT THE BASE OF THIS FEATURE.
AT THE SURFACE...A COLD FRONT HAS PUSHED WELL EAST OF THE AREA AND
COLD AIR ADVECTION IS OCCURRING WITH A WNW FLOW IN THE FRONTS
WAKE. MEANWHILE...A SURFACE HIGH IS CENTERED IN WESTERN KY. THE
PASSING TROUGH ALONG WITH WEAK COLD AIR ADVECTION ACROSS LAKE ERIE
IS PRODUCING OVERCAST STRATOCU ACROSS THE I-80 CORRIDOR.
TONIGHT...THE SURFACE HIGH WILL MOVE ACROSS KENTUCKY AND BECOME
CENTERED OVER WEST VIRGINIA BY 12Z THURSDAY. WITH A DEEP LAYER OF
DRY AIR AND SUBSIDENCE ALOFT FROM HIGH PRESSURE BUILDING
IN...SKIES WILL BE CLEAR OVERNIGHT EVERYWHERE ASIDE FROM THE I-80
CORRIDOR. A STRONG RADIATIONAL COOLING NIGHT IS SETTING UP AS
WINDS DROP TO NEAR CALM OVERNIGHT WITH THE HIGH BUILDING IN AND
TDS IN THE UPPER 20S IN OHIO ADVECTING INTO THE AREA. WITH THIS IN
MIND...FORECAST IS CLOSER TO THE COOLER MAV GUIDANCE WITH LOWS IN
THE UPPER 20S TO LOWER 30S. THUS...A WIDESPREAD FREEZE IS EXPECTED
AND A FREEZE WARNING REMAINS IN EFFECT FOR PORTIONS OF THE AREA
THAT HAVE NOT HAD A WIDESPREAD FREEZE YET THIS FALL.
THURSDAY...A ZONAL MID-LEVEL FLOW WILL REMAIN IN PLACE WITH THE
SURFACE HIGH SHIFTING EASTWARD INTO THE DELMARVA PENINSULA. THUS...THE
LOW-LEVEL FLOW WILL SHIFT TO MORE SOUTHWESTERLY THROUGH THE DAY
AND WEAK WAA ADVECTION WILL ENSUE. WITH THE DEEP LAYER OF DRY AIR
REMAINING IN PLACE...ABUNDANT SUNSHINE WILL ALSO AID IN TEMPS
RECOVERING THROUGH THE DAY. WITH THIS IN MIND...HIGHS ARE A MAV/MET
BLEND...RANGING FROM THE MID 50S ACROSS THE EASTERN RIDGES AND I-80
CORRIDOR TO NEAR 60 IN PORTIONS OF EASTERN OHIO.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
MODELS REMAIN IN GOOD OVERALL AGREEMENT...ALBEIT WITH QUICKER
TIMING THAN PREVIOUS SOLNS...IN DEPICTIONS OF CONTINUED
PROGRESSIVE FLOW FEATURING THE APPROACH AND PASSAGE OF ANOTHER
COLD FRONT FOR THURSDAY NIGHT INTO FRIDAY MORNING...BUT WITH ONLY
SLIGHT SHRA CHCS GIVEN THE LACK OF MSTR.
BUILDING HIGH PRES IS FORECAST TO QUICKLY END ANY PCPN BY MIDDAY
FRIDAY...AND ANOTHER COLD NGT IS ANTICIPATED BEFORE WARM ADVCTN
RESUMES IN ADVN OF A STRNGER SYSTEM PROJECTED ACRS THE MIDWEST.
THE SHRTWV RIDGE IN THE AMPLIFIED FLOW SPPRTS A WARMER...AND
STILL DRY SATURDAY...ALTHOUGH SLIGHT CHC POPS WERE INCLUDED OVR
NRN COUNTIES AS MDLS...WITH GFS PROJECTING A MORE SRN EXTENT...SPAWN
PCPN ALNG THE ADVNG LOWS WARM FRONT.
SHORT TERM TEMPS WERE FORECAST USING TWEAKED SREF MEANS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
LOW PRES IS STILL PROJECTED ACRS THE GREAT LAKES ON SUNDAY...AS IS
THE SYSTEMS CDFNT ACRS THE UPR OH REGION. AS IN PREVIOUS
SYSTEMS...THE BTR MID LVL SPPRT AND MSTR IS FORECAST N OF THE
AREA...HENCE POPS WERE CONFINED TO THE CHC CATEGORY...WITH THE
HIGHER NMBRS DRAWN FM PIT NWD.
THEREAFTER...CONFIDENCE IN THE LONG TERM FORECAST DROPS AS MDLS
DIVERGE IN MAGNITUDE AND TIMING OF SHRTWVS WITHIN A STILL-
PROGRESSIVE PTN. FORECAST IS THUS CLOSE TO HPC GUIDANCE IN
DEPICTIONS OF NR NORMAL TEMPS AND SLGT CHC...TO CHC POPS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
STRATO-CU STILL HANGING ACROSS NORTHERN TERMINALS IN NW 850 FLOW
AND 850 TEMPERATURES NEAR MINUS 4C. 850 FLOW GOES ZONAL EARLY THURSDAY
AND STRATO-CU SHOULD BE ON THE WANE. CURRENTLY MORE STRATO-CU
UPSTREAM BUT HRRR AND GFS SUGGESTING AS FLOW GOES ZONAL TO
SOUTHWEST...CLOUDS NOW OVER WI ERODE AND GENERALLY LIFT NORTHWARD.
WITH GENERAL FLOW GOING SOUTHWEST TODAY... WILL JUST GO WITH
SCT050 CU AND CLEAR IT OUT TOWARD SUNSET THIS EVENING BEFORE
BRINGING IN AC AND CI TOWARD 06Z FRIDAY. WINDS DECREASING ACROSS
CWA WITH DUJ ONLY TERMINAL STILL GUSTING AT THIS TIME. EXPECT
CONTINUED DIMINISHING OVERNIGHT.
.OUTLOOK.../THURSDAY NIGHT THROUGH SUNDAY/...
WEAK FRONT APPROACHES OVERNIGHT THURSDAY INTO FRIDAY WITH MID DECK
AND CI BUT EXPECT VFR CONDITIONS. HIGH PRESSURE THEN BUILDS ACROSS
REGION THROUGH SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR PAZ016-022-023-
031-073-075.
WV...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR WVZ004-012-021-
022.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1247 AM EDT THU OCT 11 2012
.SYNOPSIS...
HIGH PRESSURE WILL APPROACH FROM THE SOUTHWEST OVERNIGHT ALLOWING
CLEARING SKIES AND TEMPERATURES DROPPING BELOW FREEZING ACROSS
MUCH OF THE AREA. THE NEXT COLD FRONT WILL CROSS THE AREA THURSDAY
NIGHT INTO FRIDAY MORNING. HIGH PRESSURE WILL BUILD IN FOR THE
EARLY PART OF THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
06Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO INCREASE
THE COVERAGE OF LAKE EFFECT STRATOCU ACROSS NORTHWEST PA.
THE LATEST RAP MID- LEVEL ANALYSIS INDICATES A BROAD 500MB TROUGH
CENTERED ACROSS THE EASTERN GREAT LAKES WITH THE UPPER OHIO VALLEY
IN A WEAK CYCLONIC TO NEAR ZONAL FLOW AT THE BASE OF THIS FEATURE.
AT THE SURFACE...A COLD FRONT HAS PUSHED WELL EAST OF THE AREA AND
COLD AIR ADVECTION IS OCCURRING WITH A WNW FLOW IN THE FRONTS
WAKE. MEANWHILE...A SURFACE HIGH IS CENTERED IN WESTERN KY. THE
PASSING TROUGH ALONG WITH WEAK COLD AIR ADVECTION ACROSS LAKE ERIE
IS PRODUCING OVERCAST STRATOCU ACROSS THE I-80 CORRIDOR.
TONIGHT...THE SURFACE HIGH WILL MOVE ACROSS KENTUCKY AND BECOME
CENTERED OVER WEST VIRGINIA BY 12Z THURSDAY. WITH A DEEP LAYER OF
DRY AIR AND SUBSIDENCE ALOFT FROM HIGH PRESSURE BUILDING
IN...SKIES WILL BE CLEAR OVERNIGHT EVERYWHERE ASIDE FROM THE I-80
CORRIDOR. A STRONG RADIATIONAL COOLING NIGHT IS SETTING UP AS
WINDS DROP TO NEAR CALM OVERNIGHT WITH THE HIGH BUILDING IN AND
TDS IN THE UPPER 20S IN OHIO ADVECTING INTO THE AREA. WITH THIS IN
MIND...FORECAST IS CLOSER TO THE COOLER MAV GUIDANCE WITH LOWS IN
THE UPPER 20S TO LOWER 30S. THUS...A WIDESPREAD FREEZE IS EXPECTED
AND A FREEZE WARNING REMAINS IN EFFECT FOR PORTIONS OF THE AREA
THAT HAVE NOT HAD A WIDESPREAD FREEZE YET THIS FALL.
THURSDAY...A ZONAL MID-LEVEL FLOW WILL REMAIN IN PLACE WITH THE
SURFACE HIGH SHIFTING EASTWARD INTO THE DELMARVA PENINSULA. THUS...THE
LOW-LEVEL FLOW WILL SHIFT TO MORE SOUTHWESTERLY THROUGH THE DAY
AND WEAK WAA ADVECTION WILL ENSUE. WITH THE DEEP LAYER OF DRY AIR
REMAINING IN PLACE...ABUNDANT SUNSHINE WILL ALSO AID IN TEMPS
RECOVERING THROUGH THE DAY. WITH THIS IN MIND...HIGHS ARE A MAV/MET
BLEND...RANGING FROM THE MID 50S ACROSS THE EASTERN RIDGES AND I-80
CORRIDOR TO NEAR 60 IN PORTIONS OF EASTERN OHIO.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
MODELS REMAIN IN GOOD OVERALL AGREEMENT...ALBEIT WITH QUICKER
TIMING THAN PREVIOUS SOLNS...IN DEPICTIONS OF CONTINUED
PROGRESSIVE FLOW FEATURING THE APPROACH AND PASSAGE OF ANOTHER
COLD FRONT FOR THURSDAY NIGHT INTO FRIDAY MORNING...BUT WITH ONLY
SLIGHT SHRA CHCS GIVEN THE LACK OF MSTR.
BUILDING HIGH PRES IS FORECAST TO QUICKLY END ANY PCPN BY MIDDAY
FRIDAY...AND ANOTHER COLD NGT IS ANTICIPATED BEFORE WARM ADVCTN
RESUMES IN ADVN OF A STRNGER SYSTEM PROJECTED ACRS THE MIDWEST.
THE SHRTWV RIDGE IN THE AMPLIFIED FLOW SPPRTS A WARMER...AND
STILL DRY SATURDAY...ALTHOUGH SLIGHT CHC POPS WERE INCLUDED OVR
NRN COUNTIES AS MDLS...WITH GFS PROJECTING A MORE SRN EXTENT...SPAWN
PCPN ALNG THE ADVNG LOWS WARM FRONT.
SHORT TERM TEMPS WERE FORECAST USING TWEAKED SREF MEANS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
LOW PRES IS STILL PROJECTED ACRS THE GREAT LAKES ON SUNDAY...AS IS
THE SYSTEMS CDFNT ACRS THE UPR OH REGION. AS IN PREVIOUS
SYSTEMS...THE BTR MID LVL SPPRT AND MSTR IS FORECAST N OF THE
AREA...HENCE POPS WERE CONFINED TO THE CHC CATEGORY...WITH THE
HIGHER NMBRS DRAWN FM PIT NWD.
THEREAFTER...CONFIDENCE IN THE LONG TERM FORECAST DROPS AS MDLS
DIVERGE IN MAGNITUDE AND TIMING OF SHRTWVS WITHIN A STILL-
PROGRESSIVE PTN. FORECAST IS THUS CLOSE TO HPC GUIDANCE IN
DEPICTIONS OF NR NORMAL TEMPS AND SLGT CHC...TO CHC POPS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
STRATOCUMULUS ARE FADING QUICKLY POST-FRONTAL AS SUBSTANTIALLY
DRIER BOUNDARY LAYER AIR IS USHERED INTO THE REGION. WHILE THE LOW
LEVELS REMAIN FAIRLY UNSTABLE...A LACK OF MOISTURE SHOULD PRECLUDE
MUCH CLOUD FORMATION OVER THE AREA FOR THE NEXT 24 HOURS...WITH
ONE GIANT EXCEPTION. DOWN WIND OF LAKE ERIE...LAKE-INDUCED
STRATOCUMULUS WILL CONTINUE TO BLOSSOM DUE TO EXTREME LAKE EFFECT
INSTABILITY. LAKE TO 850 MB DELTA T VALUES ARE RUNNING UPWARDS OF
23C THIS EVENING...AND WHILE THESE VALUES WILL BE NARROWING AS THE
850 MB TEMPERATURES EDGE UP ON THURSDAY...LAKE EFFECT SHOWERS AND
CLOUDS DOWNWIND OF THE LAKE WILL BE COMMON. HOWEVER...CURRENT
BOUNDARY LAYER FLOW IS ONLY SLIGHTLY NORTH OF DUE WESTERLY...AND
THIS FLOW WILL BACK TOWARD WSW BY THURSDAY MORNING. AS
SUCH...SHOWERS AND CLOUDS WILL BE COMMON AROUND KFKL...BUT EDGE
NORTHWARD BY MORNING. NO OTHER SITES SHOULD BE IMPACTED BY
SHOWERS.
.OUTLOOK.../THURSDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL BE PREVALENT INTO SATURDAY...EVEN DESPITE A
WEAK FRONTAL PASSAGE ON FRIDAY THAT WILL HAVE LITTLE IMPACT ON THE
TERMINALS. THE BETTER CHANCE OF SHOWERS AND RESTRICTIONS WILL BE
ON SUNDAY WHEN THE NEXT COLD FRONT CROSSES THE REGION.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR PAZ016-022-023-
031-073-075.
WV...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR WVZ004-012-021-
022.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
707 PM EDT FRI OCT 12 2012
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 406 PM EDT FRI OCT 12 2012
WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL NRN STREAM
MID/UPPER LEVEL FLOW ACROSS THE NRN CONUS INTO THE WRN GREAT LAKES.
A VIGOROUS SRN STREAM LOW WAS LOCATED OVER NW AZ. AT THE SFC...SRLY
WINDS WERE INCREASING FROM THE PLAINS INTO THE UPPER MS VALLEY BTWN
HIGH PRES OVER LOWER MI AND A TROUGH DEVELOPING OVER THE WRN PLAINS.
VIS LOOP SHOWED DIURNAL CLOUDS OVER CNTRL UPPER MI THINNING AND
SHIFTING TO THE EAST AS SW WINDS DEVELOP. ANY LEFTOVER LAKE EFFECT
PCPN OVER ERN LAKE SUPERIOR HAD DISSIPATED
AS THE SFC HIGH SHIFTS TOWARD THE MID ATLANTIC STATES AND THE
SHRTWV/SFC LOW LIFTS OUT OF THE CENTRAL ROCKIES INTO THE PLAINS...A
STRENGTHENING SW FLOW WILL DEVELOP OVER THE WESTERN GREAT LAKES
TONIGHT. WITH STRONG WAA AND MOISTURE ADVECTION DEVELOPING WITH
MODERATE TO STRONG 295K-305K ISENTROPIC LIFT...RAIN WILL QUICKLY
DEVELOP AND SPREAD TO THE NORTHWEST. HOWEVER...WITH CONVECTION
LIKELY TO DEVELOP CLOSER TO THE SFC-850 MB WARM FRONT...MOISTURE
ADVECTION INTO UPPER MI MAY BE REDUCED. SO...THE NAM/ECMWF WHICH
INDICATES A SLIGHTLY LATER ARRIVAL(BTWN 09Z-12Z)OF THE PCPN WITH THE
HEAVIER PCPN MAINLY SOUTH OF UPPER MI WAS PREFERRED. EXPECT THE
STRONGER ISENTROPIC LIFT TO DIMINISH AND SHIFT TO THE EAST
DURING THE AFTERNOON AS THE SFC-850 MB WARM FRONT MOVES INTO NRN
LAKE MI AND NRN LWR MI. LIKELY TO CATEGORICAL POPS ARE STILL
WARRANTED ACROSS MUCH OF THE FCST AREA EVEN FOR PCPN AMOUNTS LESS
THAN 0.10 NORTHWEST...0.10 TO 0.25 INCH CNTRL TO NEAR 0.50 INCH EAST
AND FAR SOUTH.
INCREASING CLOUDS AND WIND WILL LIMIT THE DIURNAL FALL OF TEMP...AND
FCST THERMAL PROFILES INDICATE ANY PCPN SHOULD BE IN THE FORM OF
RAIN EVEN THOUGH TEMPS AT SOME OF THE INTERIOR COLD SPOTS MIGHT FALL
AOB 32 EARLY THIS EVENING BEFORE THE THICKER CLOUDS ARRIVE. EVEN
WITH THE STRONG WAA...PCPN AND CLOUDS WILL LIMIT HIGHS TO THE MID
AND UPPER 40S SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 406 PM EDT FRI OCT 12 2012
MOST ATTENTION IN LONG TERM ON SAT NIGHT THROUGH SUN WITH A SYSTEM
THAT MAY BRING A COUPLE INCHES OF RAIN TO PARTS OF THE REGION. THERE
IS SOME UNCERTAINTY WITH THIS SYSTEM DUE TO MODEL DISAGREEMENT.
DIFFERENCES BETWEEN MODELS INITIALLY ARE DUE TO DIFFERENCES IN UPPER
LEVEL MASS FIELDS AS A 250MB LOW MOVES FROM THE CURRENT POSITION
OVER SRN NV...TO WRN KS AS A SHORTWAVE TROUGH AT THE START OF THE
PERIOD 00Z SUN. AT 00Z SUN...THE 00Z/12 ECMWF IS ABOUT 50-60M DEEPER
AND ALSO MORE NEUTRALLY TILTED WITH 250MB HEIGHT TROUGH THAN THE
POSITIVELY TILTED GFS. THE 12Z/12 NAM IS AN OUTLIER THROUGH THE
PERIOD AS WAS RULES OUT. THE REG-GEM IS MORE OF A MIDDLE GROUND
SOLUTION THROUGH MUCH OF THE EVENT.. THE DIFFERENCES BETWEEN MODELS
CONTINUES AT 12Z SUN...WHEN THE GFS BECOMES NEUTRALLY TILED OVER THE
WRN MO BORDER WHILE THE ECMWF IS STRONGER...FASTER AND NEGATIVELY
TILTED WITH THE UPPER TROUGH OVER IA/NRN MO. EVENTUAL SFC LOW TRACK
DIFFERENCES ARE NOT DIFFERENT...ALTHOUGH THERE ARE STILL DIFFERENCES
IN SFC LOW STRENGTH...BUT SOME OF THE LARGER DIFFERENCES WITH PRECIP
AMOUNTS/PLACEMENT COME AROUND 850MB. WHILE THE STRONGER ECMWF
DEEPENS THE SYSTEM AND BRINGS A STRENGTHENING 850MB LOW FROM NE IA
12Z SUN TO NEAR THE STRAITS OF MACKINAW AROUND 00Z MON...THE GFS
BRINGS THE 850MB LOW FROM NRN LAKE SUPERIOR AT 00Z SUN TO NEAR THE
STRAITS AT 18Z SUN...THEN DEEPENS IT RAPIDLY OVER LAKE HURON BY 00Z
MON AS THE UPPER TROUGH BECOMES NEGATIVELY TILTED AND UPPER JETS
PHASE. WILL BE INTERESTED TO SEE WHAT THE 12Z/12 ECMWF COMES IN
WITH...BECAUSE THE GFS AND GEM HAVE BEEN TRENDING WEAKER /TOWARD
WHAT THEY HAVE NOW/ OVER THE LAST FEW RUNS. THE MAIN IMPACT FROM THE
WEAKER SCENARIO IS THAT THE STRONG DEFORMATION/FGEN ON THE LEFT SIDE
OF THE 850MB LOW TRACK ARE DISPLACES SE OF THE CWA...WHILE THE ECMWF
SOLUTION BRINGS A COUPLE OF INCHES OF RAIN SAT NIGHT INTO SUN.
OVERALL THINK THE BEST CHANCES OF PRECIP WILL BE OVER THE SERN CWA
CLOSER TO LAKE MICHIGAN...BOTH SAT NIGHT WITH THE WARM FRONT THAT
WILL BE JUST S OF THE CWA AND AS THE LOW PASSES SUN. WILL SHIFT POPS
SE FROM WHAT IS CURRENTLY IN THE FORECAST.
LINGERED SOME SLIGHT CHANCE POPS OVER NORTH CENTRAL AND E UPPER MI
INTO EARLY MON AS N WINDS OFF LAKE SUPERIOR MAY BRING IN SOME LAKE
EFFECT/UPSLOPE PRECIP WHILE 850MB TEMPS DECREASE TO AROUND -3C. ANY
PRECIP WILL BE LIGHT...AND SOME SOME LIGHT SNOW MAY MIX IN OVER THE
HIGHER TERRAIN LATE SUN NIGHT/EARLY MON MORNING. AS SFC RIDGE SLIDES
ACROSS THE CWA MON AFTERNOON/EVENING AHEAD OF AN UPPER RIDGE THAT
WILL MOVE OVERHEAD TUE NIGHT INTO EARLY TUE.
AFTER MON THERE IS CONSIDERABLE MODEL DISAGREEMENT...LIMITED
CONFIDENCE IN THE FORECAST...ESPECIALLY POPS. HOWEVER...IT DOES
APPEAR MORE CERTAIN THAT TUE AND WED WILL BE WARMER WITH HIGHS
GENERALLY IN THE 50S. USED CONSENSUS OF MODELS FOR MON NIGHT THROUGH
FRI.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 707 PM EDT FRI OCT 12 2012
AS A DRY HIGH PRES RIDGE MOVES ACRS THE UPR LKS...EXPECT VFR
CONDITIONS TO PREDOMINATE INTO TONIGHT. A STRENGTHENING SSW FLOW
TONIGHT BTWN THE DEPARTING HI AND LOW PRES TAKING SHAPE IN THE
PLAINS WILL RESULT IN SOME MARGINAL LLWS AS WELL AS INCREASING
CLOUDS. ENOUGH MOISTURE MAY ARRIVE LATE IN THE FCST PERIOD TO CAUSE
MVFR CIGS CLOSER TO THE WI BORDER AT IWD. STRONGER MOISTURE INFLOW
AHEAD OF WARM FRONT OVER WI WILL BRING LOWER CIGS INTO THE MVFR
RANGE AT ALL SITES INTO SATURDAY. SRLY LOW LEVEL FLOW FAVORS EVEN
LOWER CIGS INTO THE IFR RANGE AT SAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 PM EDT FRI OCT 12 2012
A STEADY SSW WIND UP TO 25 KTS WILL PREVAIL TONIGHT BETWEEN THE
DEPARTING HI AND DEVELOPING LO PRES IN THE PLAINS. AS THE LO PRES
CENTER MOVES TO THE E JUST S OF UPPER MI EARLY SUN...LOOK FOR THE
WINDS TO BACK TO THE N AND INCREASE UP TO 25 TO 30 KTS...ESPECIALLY
OVER THE E HALF. MAY SEE A FEW GALE FORCE GUSTS OVER PORTIONS OF
EASTERN LAKE SUPERIOR SUN. THE APPROACH OF HIGH PRES ON MON WILL CAUSE
A STEADY DECREASE IN WIND SPEED LATER SUN INTO MON. SOUTH WINDS WILL
INCREASE TO 25 KTS OVER MAINLY THE ERN HALF OF THE LAKE ON TUESDAY
AHEAD OF A LOW PRESSURE SYSTEM DEVELOPING OVER THE NRN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1054 AM EDT THU OCT 11 2012
.SYNOPSIS...
ISSUED AT 345 AM EDT THU OCT 11 2012
WINDY CONDITIONS AND A FEW SHOWERS ARE ANTICIPATED TODAY AS A
CLIPPER SYSTEM MOVES THROUGH. SOME SHOWERS WILL LINGER TONIGHT
BEFORE FAIR WEATHER RETURNS FRIDAY AS HIGH PRESSURE BUILDS IN. A
STRONG LOW PRESSURE SYSTEM WILL MOVE THROUGH OUR REGION THIS WEEKEND
BRINGING POTENTIAL FOR WINDY CONDITIONS HEAVY RAINFALL AND
THUNDERSTORMS.
&&
.UPDATE...
ISSUED AT 1052 AM EDT THU OCT 11 2012
HAVE HOISTED A WIND ADVISORY FOR A GOOD PORTION OF THE FORECAST
AREA AS WINDS RAMP UP AHEAD OF THE COLD FRONT. TIGHT GRADIENT IS
IN PLACE AHEAD OF THE FRONT. SOUTHWEST FLOW OFF THE LAKE WILL PEAK
ACROSS THE GRR FORECAST AREA BETWEEN NOON AND 400 PM. WIND GUSTS
WILL PUSH TOWARDS 45 MPH. IT WILL BE A CLOSE CALL...NOT A SLAM
DUNK IT APPEARS ESPECIALLY GIVEN THE CLOUDS TRYING TO ADVANCE IN
FROM THE NORTH. IF THESE CLOUDS SLOW OR ERODE A BIT ON THE SOUTH
EDGE THE MIXING WILL ENHANCE THE WIND GUSTS. HRRR IS SHOWING A
PRETTY GOOD BET FOR WIND GUSTS PUSHING INTO THE 40-50 MPH.
ESPECIALLY DOWN WIND OF THE LAKE IN SOUTHWEST FLOW FROM LWA/MKG
INLAND TO LAN/AMN. OTHERWISE FORECAST IN GOOD SHAPE WITH SOME
LIGHT SHOWERS TRYING TO ADVANCE SOUTH WITH TIME THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON)
ISSUED AT 345 AM EDT THU OCT 11 2012
A CLIPPER SYSTEM WILL BRING WINDY CONDITIONS TODAY. IN FACT
CONDITIONS MAY FLIRT WITH WIND ADVISORY CRITERIA (GUSTS REACHING 45
MPH) BY LATE MORNING INTO THIS AFTERNOON. DECIDED AGAINST A HEADLINE
THOUGH SINCE GUSTS PRIMARILY IN THE 35 TO 44 MPH ARE THE MOST
PROBABLE OUTCOME WITH MINIMAL IMPACTS. THIS SYSTEM WILL ALSO BRING A
FEW SHOWERS THIS AFTN/TONIGHT. BUMPED POPS UP SLIGHTLY INTO THE LOW
CHC CATEGORY FOR THE SOUTHERN TWO THIRDS OF OUR FCST AREA TONIGHT
BASED ON OVERALL SHORT RANGE GUIDANCE TRENDS.
FAIR WX IS ANTICIPATED FRIDAY THROUGH FRIDAY NIGHT WITH HIGH
PRESSURE IN CONTROL. THE WARM FRONT ASSOCIATED WITH THE STRONG LOW
PRESSURE SYSTEM OFF TO OUR WEST WILL BRING RAIN AND A CHC OF
THUNDERSTORMS SATURDAY. THIS AS ELEVATED INSTABILITY INCREASES AND
H8 LI/S GO SLIGHTLY NEGATIVE ALONG WITH INCREASING 1000-850 MB
MOISTURE TRANSPORT AND PRECIPITABLE WATER VALUES REACHING THE 1.5 TO
1.75 INCH RANGE BY MIDDAY SATURDAY. THE THREAT FOR ANY SVR WX WILL
MOST LIKELY HOLD OFF UNTIL SATURDAY NIGHT INTO SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM EDT THU OCT 11 2012
STRONG FALL STORM MOVES THROUGH SATURDAY NIGHT AND SUNDAY. BUMPED UP
POPS...ESPECIALLY ACROSS THE NORTH WHERE CATEGORICAL IS WARRANTED.
GFS CONTINUES TO SHOW VERY STRONG SHEAR PROFILES AND SOME
INSTABILITY SATURDAY NIGHT...SO THREAT FOR SEVERE WEATHER WILL BE
PRESENT. CONVECTION OVER WISCONSIN ON SATURDAY COULD MAKE IT INTO
LOWER MICHIGAN SATURDAY EVENING IN THE FORM AN ORGANIZED LINE OF
STORMS.
SOME ROTATING STORMS COULD BE EMBEDDED IN THIS LINE ACROSS
THE SOUTHERN FORECAST AREA WHERE 0 TO 1 KM STORM RELATIVE HELICITY
IS PROGGED TO BE OVER 100. OVERALL THREAT APPEARS TO BE STRAIGHT
LINE WINDS AS ENVIRONMENTAL WINDS ARE ABOVE 50 KNOTS WITHIN 3 KFT
AGL. TORNADIC THREAT IS SECONDARY AND MOSTLY CONFINED TO THE SOUTH.
SFC LOW TRACKS ACROSS NORTHERN LOWER MICHIGAN SUNDAY WITH THE COLD
FRONT MOVING THROUGH AND SHOWERS TAPERING OFF SUNDAY NIGHT. SFC
RIDGE WILL HOLD SWAY INTO TUESDAY NIGHT. DROPPED POPS FOR TUESDAY.
NORTHERN STREAM SHORTWAVE APPROACHES BY WEDNESDAY WITH SHOWERS
ARRIVING AND CONTINUING WED NIGHT AS TROUGH AXIS ARRIVES ALONG WITH
SFC CYCLONE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 718 AM EDT THU OCT 11 2012
VFR CONDITIONS EXPECTED TODAY AND INTO TONIGHT. SOME SHOWERS ARE
EXPECTED THIS EVENING BUT MVFR CONDITIONS ARE NOT EXPECTED TO BE
WIDESPREAD. SOUTHWEST WINDS WILL PICK UP THIS MORNING WITH GUSTS
OVER 25 KNOTS MOST OF THIS AFTERNOON.
&&
.MARINE...
ISSUED AT 345 AM EDT THU OCT 11 2012
A GALE WARNING IS IN EFFECT WITH 35 TO 40 KNOT GALES ANTICIPATED
THROUGH THIS AFTERNOON. WAVE HEIGHTS COULD REACH 8 TO 12 FEET WITH
HIGHEST WAVES NORTH OF GRAND HAVEN. WINDS AND WAVES WILL GRADUALLY
DIMINISH TONIGHT AND PARTICULARLY FRIDAY AS HIGH PRESSURE BUILDS IN.
&&
.HYDROLOGY...
ISSUED AT 345 AM EDT THU OCT 11 2012
NO HYDRO ISSUES THROUGH FRIDAY. A STRONG LOW PRESSURE SYSTEM HAS
POTENTIAL TO BRING SOME HEAVY RAINFALL THIS WEEKEND WITH TOTAL
RAINFALL AMOUNTS OF AN INCH OR TWO WITH LOCALLY HIGHER AMOUNTS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MIZ037-043>046-
050>052-056>059-064>067-071>074.
LM...GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR LMZ844>849.
&&
$$
UPDATE...DUKE
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...OSTUNO
HYDROLOGY...LAURENS
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
542 AM EDT THU OCT 11 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 450 PM EDT WED OCT 10 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A TROF OVER
CNTRL NAMERICA. NEXT SHORTWAVE DROPPING INTO THE TROF IS CURRENTLY
HEADING SE THRU SASKATCHEWAN TOWARD SRN MANITOBA. THIS WAVE WILL BE
THE MAIN FCST ISSUE IN THE SHORT TERM. OTHERWISE...ALTHOUGH 850MB
THERMAL TROF (TEMPS OF -6 TO -8C) IS STILL CROSSING THE AREA...LAKE
EFFECT PCPN HAS BEEN GRADUALLY WINDING DOWN FROM W TO E DUE TO
SOMEWHAT DRIER AIR ADVECTING INTO THE AREA AND FLOW BECOMING MORE
ANTICYCLONIC. MORE IMPORTANT NEGATIVE FACTOR IS PROBABLY DAYTIME
HEATING DISRUPTING LAKE EFFECT PROCESSES.
LINGERING LAKE EFFECT PCPN WILL CONTINUE TO DIMINISH AND SHIFT MORE
OFFSHORE AS WINDS BACK WITH SFC HIGH PRES RIDGE PASSING. LAST OF THE
PCPN SHOULD EXIT NRN LUCE COUNTY AROUND 06Z. ATTENTION THEN TURNS TO
APPROACHING SHORTWAVE. THERE ISN`T MUCH DIFFERENCE IN MODELS...BUT
WILL FAVOR THE REGIONAL GEM WHICH HAS BEEN VERY CONSISTENT SHOWING
MORE PCPN WITH THIS SYSTEM. FAIRLY ROBUST DEEP LAYER FORCING PER
QVECTORS ALONG WITH DECENT ISENTROPIC ASCENT (285-290K SFCS)
SUGGESTS PCPN IS A GOOD BET...ESPECIALLY ACROSS THE N AND E...CLOSER
TO SHORTWAVE TRACK. PCPN SHOULD SPREAD INTO THE W LATE EVENING AND
REACH THE E OVERNIGHT. 1000-850MB THICKNESSES IN THE 1302-1310M
RANGE SUGGEST A MIX OF RAIN/SNOW WILL OCCUR. HIGH TERRAIN SHOULD BE
PREDOMINANTLY SNOW...TRANSITIONING TO MAINLY RAIN NEAR THE GREAT
LAKES. WITH 0.1 TO 0.3 INCHES OF PCPN...MAY SEE A SLUSHY INCH OR TWO
OF SNOW ACCUMULATION IN THE HIGH TERRAIN. WINDS MAY BACK JUST ENOUGH
FOR SOME LAKE ENHANCEMENT OFF LAKE MICHIGAN INTO THE FAR ERN FCST
AREA...SO PCPN AMOUNTS MAY BE HIGHER THERE. WITH LOW-LEVELS SLIGHTLY
WARMER...LAKE ENHANCED PCPN OVER THE E SHOULD BE MOSTLY IN THE FORM
OF RAIN. TEMPS WILL HAVE A BRIEF OPPORTUNITY TO FALL THIS EVENING
(SHOULD FALL BLO FREEZING IN MANY AREAS)...BUT THICKENING CLOUDS
WILL RESULT IN TEMPS RISING A LITTLE AFTER EARLY LOWS.
THERE MAY BE A BRIEF PERIOD OF NW FLOW LAKE ENHANCEMENT THU MORNING
BEFORE FORCING EXITS AND STRONG DEEP LAYER QVECTOR DIVERGENCE AND
MID LEVEL DRYING ARRIVE. THAT WILL HELP MORE WIDESPREAD PCPN LINGER
A BIT LONGER IN THE AREAS AFFECTED BY NW FLOW OFF LAKE SUPERIOR. CAA
DROPS 850MB TEMPS TO -5 TO -7C DURING THE DAY...WHICH WILL SUPPORT
SOME LAKE EFFECT PCPN. GIVEN EARLY SEASON/DIURNAL HEATING...IT WILL
BE MORE OF A HYBRID TYPE PCPN PATTERN WITH NOT SO MUCH BANDING OFF
THE LAKE...BUT ISOLD/SCT SHOWERS EXTENDING WELL INLAND.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 450 PM EDT WED OCT 10 2012
THURSDAY NIGHT...THE SHORTWAVE TROUGH WILL EXIT THE NRN GREAT LAKES
WITH STRONG STRONG 700-300 MB QVECTOR CONV IN ITS WAKE. AS SFC HIGH
PRES BUILDS FROM THE NRN PLAINS INTO THE UPPER MS VALLEY NW FLOW WILL
CONTINUE ACROSS LAKE SUPERIOR WITH 850 MB TEMPS INTO THE -7C TO -8C
RANGE. WITH WATER TEMPS FROM 7C TO 12C...THERE WILL BE MORE THAN
ENOUGH INSTABILITY TO SUSTAIN LAKE EFFECT PCPN. EVEN THROUGH OVERALL
WINDS WILL BE NORTHWEST...EXPECT THEAT LAKE INDUCED TROUGHING WILL
HELP TO FOCUS LOW LEVEL CONV INTO AREAS NEAR P53 AND GRAND MARAIS.
ALTHOUGH THE LONG FETCH ACROSS THE LAKE WILL KEEP TEMPS RELATIVELY
WARM OVER THE EAST...EXPECT MAINLY SNOW WITH A COATING TO HALF AN
INCH OF ACCUMULATION IN SOME LOCATIONS. OVER THE WEST...THE PCPN WILL
TAPER OFF SOONER AS THE RIDGE AND BUILDS TOWARD THE AREA WITH LIGHT
ACYC FLOW.
FRI...ANY LINGERING LAKE EFFECT PCPN INTO THE NORTHEAST CWA WILL
TAPER OFF QUICKLY IN THE MORNING AS WINDS BACK WITH THE RIDGE
BUILDING INTO THE AREA. SUNSHINE AND DEVELOPING WAA WITH SW FLOW
SHOULD HELP PUSH TEMPS INTO THE MID AND UPPER 40S...PER FCST
SOUNDINGS.
FRI NIGHT AND SAT...MODELS WERE IN GOOD AGREEMENT WITH THE OVERALL
PATTERN RESULTING IN STRONG WAA AND MOISTURE ADVECTION INTO THE
UPPER GREAT LAKES AS A STRONG SHRTWV MOVES THROUGH THE CNTRL PLAINS.
300K-310K ISENTROPIC LIFT SUPPORTED BY UPPER LEVEL DIV WITH THE
RIGHT EXIT REGION OF THE 250-300 JET OVER NRN ONTARIO WILL SUPPORT
WIDESPREAD RAIN FROM WI SPREADING INTO UPPER MI. THE NAM/SREF WAS
PREFERRED IN WITH A LATER ONSET OF PCPN AND KEEPING THE GREATER QPF
A BIT FARTHER SOUTH...CLOSER TO THE 850 MB WARM FRONT AND GREATER
ELEVATED CAPE.
SAT NIGHT INTO SUN...THE GFS...12Z GEFS AND GEM REMAINED A BIT
FARTHER NORTH WITH THE TRACK OF THE MID LEVEL SHORTWAVE AND SFC LOW
COMPARED TO THE ECMWF. SO...THERE IS GREATER UNCERTAINTY WITH THE
POSITION AND POTENTIAL FOR HEAVY PCPN ASSOCIATED WITH THE STRONG
FGEN/DEF AS THE 700 MB LOW MOVES THROUGH. WITH EITHER SCENARIO...A
COLD WIND DRIVEN RAIN MAY LINGER INTO SUNDAY WITH WRAP-AROUND PCPN
AND SOME LAKE ENHANCEMENT OFF OF LAKE SUPERIOR AS 850 MB TEMPS DROP
TO AROUND 0C.
MON-WED...MODELS WERE SIMILAR WITH A PROGRESSIVE PATTERN EARLY NEXT
WEEK BUT SHOW EXPECTED DIFFERENCES WITH DETAILS. A WAA PATTERN WITH
THE POTENTIAL FOR MORE RAIN...ESPECIALLY FROM TUE NIGHT INTO
WED...PER MDLS CONSENSUS. TEMPS ARE EXPECTED CLIMB BACK VALUES AOA
SEASONAL AVERAGES.
&&
FOR THE EXTENDED...
ISSUED AT 541 AM EDT THU OCT 11 2012
MODELS ARE STILL IN FAIRLY GOOD AGREEMENT IN THE PLACEMENT OF A
MID/UPPER LEVEL RIDGE OVER THE PLAINS THROUGH THE DAY FRIDAY...WITH
THE ASSOCIATED SURFACE HIGH PRESSURE DOMINATING THE UPPER GREAT
LAKES REGION THROUGH SATURDAY. THIS WILL KEEP DRY WEATHER WITH
PREDOMINATE LIGHT N/NERLY WINDS THROUGH THIS TIME PERIOD.
SUNNY/PARTLY CLOUDY SKIES WILL KEEP TEMPERATURES FAIRLY STEADY /AT
OR SLIGHTLY BELOW NORMAL/...WITH COOLEST TEMPERATURES NEAR LAKE
SUPERIOR DUE TO NORTHERLY WINDS OFF THE LAKE.
MODEL CONSENSUS ALSO SHOWS A SHORTWAVE DEVELOPING ON THE BACKSIDE OF
THE RIDGE...HOWEVER DISAGREEMENTS COME IN TO PLAY ON THE PATH THIS
SHORTWAVE WILL TAKE. GFS AND GEM SOLUTIONS HAVE THE SHORTWAVE
DEVELOPING OVER THE PLAINS ON SATURDAY...THEN GETTING PUSHED TO THE
SOUTHEAST UNDER THE INFLUENCE OF THE HIGH PRESSURE RIDGE AND DRY AIR
ALREADY IN PLACE. THIS SOLUTION SEEMS THE MOST REASONABLE. ECMWF
SOLUTION ON THE OTHER HAND CONTINUES TO BE MORE AGGRESSIVE WITH THIS
SYSTEM...MOVING IT NORTHEAST ALONG THE BACKSIDE OF THE RIDGE AND
REACHING THE UPPER GREAT LAKES BY SATURDAY AFTERNOON. WITH THE
GFS/GEM...UPPER MI SHOULD REMAIN DRY. HOWEVER WILL KEEP SLIGHT
CHANCES NEAR THE WI BORDER SATURDAY AFTERNOON...SPREADING FURTHER
INLAND SATURDAY NIGHT AND SUNDAY TO ACCOUNT FOR ECMWF SOLUTION. WITH
THE INCREASE IN CLOUD COVER ASSOCIATED WITH THIS SYSTEM...EXPECT LOW
TEMPERATURES SAT NIGHT TO BE SLIGHTLY WARMER THAN PREVIOUS...BUT
STILL HOVERING ON THE FREEZING LINE...SO SNOW COULD MIX IN WITH RAIN
IN AFFECTED AREAS. PRECIP SHOULD DISSIPATE BY SUNDAY NIGHT AS
SHORTWAVE MOVES TO THE SOUTHEAST AND HIGH PRESSURE BEGINS TO BUILD
IN FROM CANADA THROUGH THE DAY MONDAY.
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1205 AM EDT THU OCT 11 2012
A DISTURBANCE WILL QUICKLY MOVE INTO THE AREA OVERNIGHT. EXPECT A
PERIOD OF MVFR CONDITIONS AS -SN/-RA SPREAD ACROSS THE AREA. PCPN
SHOULD BE MAINLY SN AT KCMX/KSAW. PCPN WILL DIMINISH/END LATE
TONIGHT/THU MORNING...BUT MVFR CIGS MAY LINGER THRU THE MORNING AT
KCMX/KSAW BEFORE COMING VFR IN THE AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 541 AM EDT THU OCT 11 2012
EXPECT NW GALES TO 35 KTS TO DEVELOP THIS AFTERNOON OVER THE E HALF
OF THE LAKE AS COLDER AIR FOLLOWS A VIGOUROUS DISTURBANCE PASSING
INTO SE CANADA AND ALLOWS EFFICIENT MIXING OVER THE RELATIVELY WARM
LAKE WATERS OF STRONGER WINDS JUST ABOVE THE SURFACE. LIGHTER WINDS
WILL THEN PREVAIL TONIGHT THRU FRI AS A HI PRES RIDGE/WEAKER PRES
GRADIENT FOLLOWS INTO THE UPPER LAKES. STRONGER S WINDS UP 25 TO 30
KTS MAY IMPACT MAINLY THE E HALF ON SAT AS A SHARPER PRES GRADIENT
BETWEEN THE DEPARTING HI AND LO PRES MOVING NE FROM THE PLAINS
DEVELOPS OVER THE AREA. AS THE LO PRES CENTER MOVES TO THE E JUST S
OF UPPER MI EARLY SUN...LOOK FOR THE WINDS TO BACK TO THE N AND
INCREASE UP TO 25 TO 30 KTS...ESPECIALLY OVER THE E HALF. THE
APPROACH OF HI PRES ON MON WILL CAUSE A STEADY DECREASE IN WIND
SPEED LATER SUN INTO MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
LSZ249>251-266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLB
EXTENDED...
AVIATION...07
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1205 AM EDT THU OCT 11 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 450 PM EDT WED OCT 10 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A TROF OVER
CNTRL NAMERICA. NEXT SHORTWAVE DROPPING INTO THE TROF IS CURRENTLY
HEADING SE THRU SASKATCHEWAN TOWARD SRN MANITOBA. THIS WAVE WILL BE
THE MAIN FCST ISSUE IN THE SHORT TERM. OTHERWISE...ALTHOUGH 850MB
THERMAL TROF (TEMPS OF -6 TO -8C) IS STILL CROSSING THE AREA...LAKE
EFFECT PCPN HAS BEEN GRADUALLY WINDING DOWN FROM W TO E DUE TO
SOMEWHAT DRIER AIR ADVECTING INTO THE AREA AND FLOW BECOMING MORE
ANTICYCLONIC. MORE IMPORTANT NEGATIVE FACTOR IS PROBABLY DAYTIME
HEATING DISRUPTING LAKE EFFECT PROCESSES.
LINGERING LAKE EFFECT PCPN WILL CONTINUE TO DIMINISH AND SHIFT MORE
OFFSHORE AS WINDS BACK WITH SFC HIGH PRES RIDGE PASSING. LAST OF THE
PCPN SHOULD EXIT NRN LUCE COUNTY AROUND 06Z. ATTENTION THEN TURNS TO
APPROACHING SHORTWAVE. THERE ISN`T MUCH DIFFERENCE IN MODELS...BUT
WILL FAVOR THE REGIONAL GEM WHICH HAS BEEN VERY CONSISTENT SHOWING
MORE PCPN WITH THIS SYSTEM. FAIRLY ROBUST DEEP LAYER FORCING PER
QVECTORS ALONG WITH DECENT ISENTROPIC ASCENT (285-290K SFCS)
SUGGESTS PCPN IS A GOOD BET...ESPECIALLY ACROSS THE N AND E...CLOSER
TO SHORTWAVE TRACK. PCPN SHOULD SPREAD INTO THE W LATE EVENING AND
REACH THE E OVERNIGHT. 1000-850MB THICKNESSES IN THE 1302-1310M
RANGE SUGGEST A MIX OF RAIN/SNOW WILL OCCUR. HIGH TERRAIN SHOULD BE
PREDOMINANTLY SNOW...TRANSITIONING TO MAINLY RAIN NEAR THE GREAT
LAKES. WITH 0.1 TO 0.3 INCHES OF PCPN...MAY SEE A SLUSHY INCH OR TWO
OF SNOW ACCUMULATION IN THE HIGH TERRAIN. WINDS MAY BACK JUST ENOUGH
FOR SOME LAKE ENHANCEMENT OFF LAKE MICHIGAN INTO THE FAR ERN FCST
AREA...SO PCPN AMOUNTS MAY BE HIGHER THERE. WITH LOW-LEVELS SLIGHTLY
WARMER...LAKE ENHANCED PCPN OVER THE E SHOULD BE MOSTLY IN THE FORM
OF RAIN. TEMPS WILL HAVE A BRIEF OPPORTUNITY TO FALL THIS EVENING
(SHOULD FALL BLO FREEZING IN MANY AREAS)...BUT THICKENING CLOUDS
WILL RESULT IN TEMPS RISING A LITTLE AFTER EARLY LOWS.
THERE MAY BE A BRIEF PERIOD OF NW FLOW LAKE ENHANCEMENT THU MORNING
BEFORE FORCING EXITS AND STRONG DEEP LAYER QVECTOR DIVERGENCE AND
MID LEVEL DRYING ARRIVE. THAT WILL HELP MORE WIDESPREAD PCPN LINGER
A BIT LONGER IN THE AREAS AFFECTED BY NW FLOW OFF LAKE SUPERIOR. CAA
DROPS 850MB TEMPS TO -5 TO -7C DURING THE DAY...WHICH WILL SUPPORT
SOME LAKE EFFECT PCPN. GIVEN EARLY SEASON/DIURNAL HEATING...IT WILL
BE MORE OF A HYBRID TYPE PCPN PATTERN WITH NOT SO MUCH BANDING OFF
THE LAKE...BUT ISOLD/SCT SHOWERS EXTENDING WELL INLAND.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 450 PM EDT WED OCT 10 2012
THURSDAY NIGHT...THE SHORTWAVE TROUGH WILL EXIT THE NRN GREAT LAKES
WITH STRONG STRONG 700-300 MB QVECTOR CONV IN ITS WAKE. AS SFC HIGH
PRES BUILDS FROM THE NRN PLAINS INTO THE UPPER MS VALLEY NW FLOW WILL
CONTINUE ACROSS LAKE SUPERIOR WITH 850 MB TEMPS INTO THE -7C TO -8C
RANGE. WITH WATER TEMPS FROM 7C TO 12C...THERE WILL BE MORE THAN
ENOUGH INSTABILITY TO SUSTAIN LAKE EFFECT PCPN. EVEN THROUGH OVERALL
WINDS WILL BE NORTHWEST...EXPECT THEAT LAKE INDUCED TROUGHING WILL
HELP TO FOCUS LOW LEVEL CONV INTO AREAS NEAR P53 AND GRAND MARAIS.
ALTHOUGH THE LONG FETCH ACROSS THE LAKE WILL KEEP TEMPS RELATIVELY
WARM OVER THE EAST...EXPECT MAINLY SNOW WITH A COATING TO HALF AN
INCH OF ACCUMULATION IN SOME LOCATIONS. OVER THE WEST...THE PCPN WILL
TAPER OFF SOONER AS THE RIDGE AND BUILDS TOWARD THE AREA WITH LIGHT
ACYC FLOW.
FRI...ANY LINGERING LAKE EFFECT PCPN INTO THE NORTHEAST CWA WILL
TAPER OFF QUICKLY IN THE MORNING AS WINDS BACK WITH THE RIDGE
BUILDING INTO THE AREA. SUNSHINE AND DEVELOPING WAA WITH SW FLOW
SHOULD HELP PUSH TEMPS INTO THE MID AND UPPER 40S...PER FCST
SOUNDINGS.
FRI NIGHT AND SAT...MODELS WERE IN GOOD AGREEMENT WITH THE OVERALL
PATTERN RESULTING IN STRONG WAA AND MOISTURE ADVECTION INTO THE
UPPER GREAT LAKES AS A STRONG SHRTWV MOVES THROUGH THE CNTRL PLAINS.
300K-310K ISENTROPIC LIFT SUPPORTED BY UPPER LEVEL DIV WITH THE
RIGHT EXIT REGION OF THE 250-300 JET OVER NRN ONTARIO WILL SUPPORT
WIDESPREAD RAIN FROM WI SPREADING INTO UPPER MI. THE NAM/SREF WAS
PREFERRED IN WITH A LATER ONSET OF PCPN AND KEEPING THE GREATER QPF
A BIT FARTHER SOUTH...CLOSER TO THE 850 MB WARM FRONT AND GREATER
ELEVATED CAPE.
SAT NIGHT INTO SUN...THE GFS...12Z GEFS AND GEM REMAINED A BIT
FARTHER NORTH WITH THE TRACK OF THE MID LEVEL SHORTWAVE AND SFC LOW
COMPARED TO THE ECMWF. SO...THERE IS GREATER UNCERTAINTY WITH THE
POSITION AND POTENTIAL FOR HEAVY PCPN ASSOCIATED WITH THE STRONG
FGEN/DEF AS THE 700 MB LOW MOVES THROUGH. WITH EITHER SCENARIO...A
COLD WIND DRIVEN RAIN MAY LINGER INTO SUNDAY WITH WRAP-AROUND PCPN
AND SOME LAKE ENHANCEMENT OFF OF LAKE SUPERIOR AS 850 MB TEMPS DROP
TO AROUND 0C.
MON-WED...MODELS WERE SIMILAR WITH A PROGRESSIVE PATTERN EARLY NEXT
WEEK BUT SHOW EXPECTED DIFFERENCES WITH DETAILS. A WAA PATTERN WITH
THE POTENTIAL FOR MORE RAIN...ESPECIALLY FROM TUE NIGHT INTO
WED...PER MDLS CONSENSUS. TEMPS ARE EXPECTED CLIMB BACK VALUES AOA
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1205 AM EDT THU OCT 11 2012
A DISTURBANCE WILL QUICKLY MOVE INTO THE AREA OVERNIGHT. EXPECT A
PERIOD OF MVFR CONDITIONS AS -SN/-RA SPREAD ACROSS THE AREA. PCPN
SHOULD BE MAINLY SN AT KCMX/KSAW. PCPN WILL DIMINISH/END LATE
TONIGHT/THU MORNING...BUT MVFR CIGS MAY LINGER THRU THE MORNING AT
KCMX/KSAW BEFORE COMING VFR IN THE AFTERNOON.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 PM EDT WED OCT 10 2012
ATTENTION OVER THE NEXT 24HRS IS ON LOW PRES WHICH WILL BE MOVING
ACROSS OR JUST N OF LAKE SUPERIOR LATE TONIGHT AND THU MORNING.
STRONGEST WINDS THRU EARLY THIS EVENING WILL BE OVER ERN LAKE
SUPERIOR WHERE NW WINDS WILL BE GUSTING TO 30KT WITH A FEW GUSTS TO
GALE FORCE. WINDS WILL BRIEFLY BE IN THE 15-25KT RANGE FOR A TIME
TONIGHT BEFORE INCREASING AGAIN LATE AS THE LOW ARRIVES IN THE UPPER
LAKES. SW WINDS MAY GUST TO NEAR 30KT LATE TONIGHT. OF MORE CONCERN
WILL BE THE NW WINDS DEVELOPING THU AS THE LOW SHIFTS E OF THE LAKE.
AIDED BY INCREASINGLY COLDER AIR AND PRES RISES APPROACHING FROM THE
NW...A PERIOD OF NW GALES IS A POSSIBILITY OVER THE E HALF OF LAKE
SUPERIOR. MAY NEED TO HOIST A GALE WARNING IF NEW GUIDANCE ARRIVING
THIS EVENING MORE SOLIDLY SUPPORTS GALES.
A MODERATELY STRONG LOW PRESSURE SYSTEM IS EXPECTED TO TRACK THROUGH
THE WESTERN GREAT LAKES. SOUTH WINDS OF 15 TO 25 KNOTS ARE EXPECTED
AHEAD OF THE SYSTEM SATURDAY WHILE NORTHERLY 15 TO 25 KNOT WINDS ARE
WILL DEVELOP AS THE LOW PULLS AWAY SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
LSZ249>251-266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLB
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
105 PM CDT THU OCT 11 2012
.SHORT TERM...
ISSUED AT 311 AM CDT THU OCT 11 2012
(TODAY THROUGH FRIDAY NIGHT)
WARM ADVECTION UNDER WAY OVER SOUTHWEST MISSOURI AT THIS TIME.
CLOUD DECK BETWEEN 5000-8000FT IS MOVING SLOWLY NORTHEAST TOWARD OUR
AREA. CLOUDS SHOULD OVERSPREAD CENTRAL MISSOURI BY LATE MORNING AND
ON INTO EASTERN MISSOURI EARLY IN THE AFTERNOON. EVEN THOUGH PRECIP
HAS YET TO DEVELOP...SHORT-RANGE MODELS CONTINUE TO PRINT OUT PRECIP
DUE TO THE STRONG WARM ADVECTION AND MOISTURE CONVERGENCE ON THE
850MB BAROCLINIC ZONE ACROSS SOUTHERN MISSOURI. FORECAST SOUNDINGS
ARE PRETTY STRONGLY CAPPED THOUGH SO WOULD EXPECT THAT PRECIP WILL
BE PRETTY SCATTERED. HRRR DEVELOPS ISOLATED TO WIDELY SCATTERED
PRECIP...SO THIS JIVES WELL WITH THAT THINKING. WARM ADVECTION WILL
CONTINUE TONIGHT OVER SOUTHERN MISSOURI AND A SUBTLE SHORTWAVE WILL
BRING ANOTHER CANADIAN HIGH AND A SHOT OF COOL AIR DOWN FROM THE
NORTHERN PLAINS INTO MISSOURI TO REINFORCE THE BAROCLINIC ZONE. THE
STRONG BAROCLINICITY AND CONTINUING LOW LEVEL JET COMBINED WITH THE
SHORTWAVE PASSING OVERHEAD SHOULD PRODUCE MORE WIDESPREAD RAIN AND
THUNDERSTORMS. THE LOW LEVEL JET AND MOISTURE CONVERGENCE STAYS
FOCUSED OVER SOUTHERN MISSOURI...SO HAVE BACKED DOWN TO CHANCE POPS
ALONG THE I-70 CORRIDOR TONIGHT BUT KEPT LIKELY DOWN OVER THE
OZARKS. LOW LEVEL JET CHANGES FOCUS TO THE GREAT PLAINS ON FRIDAY
WHICH SHOULD BRING THE RAIN OVER SOUTHEAST MISSOURI TO AN END. THE
AFOREMENTIONED CANADIAN HIGH MOVES OVER THE MID ATLANTIC FRIDAY
NIGHT WHICH TURNS LOW LEVEL FLOW TO THE SOUTH. THIS PUSHES A WARM
FRONT UP THROUGH OUR AREA INTO THE UPPER MIDWEST SETTING THE STAGE
FOR A WARM SATURDAY AND POTENTIALLY SEVERE WEATHER SATURDAY NIGHT.
CARNEY
&&
.LONG TERM...
ISSUED AT 340 AM CDT THU OCT 11 2012(SATURDAY THROUGH WEDNESDAY)
WE SHOULD BE WELL INTO THE WARM SECTOR ON SATURDAY. NAM AND GFS
SHOW 14-16C AT 850MB SATURDAY AFTERNOON SO AM GOING AT OR ABOVE
UPPER RANGE OF GUIDANCE TEMPS. THE SYNOPTIC SETUP REMAINS
FAVORABLE FOR SEVERE WEATHER SATURDAY AFTERNOON AND NIGHT. THE
DETAILS IN THE MODELS ARE VERY SIMILAR AND HAVE BEEN VERY
CONSISTENT. DEEP LAYER SHEAR IN EXCESS OF 50KTS WITH A STRONG
SHORTWAVE AND LOW LEVEL MOISTURE WILL BE IN PLACE. CONVECTION LOOKS
TO DEVELOP OVER EASTERN KANSAS AND SHOULD MOVE INTO MISSOURI DURING
THE LATE AFTERNOON. FOR OUR AREA...BEST CHANCE FOR STORMS WILL BE
SATURDAY NIGHT. DAY 3 SEVERE OUTLOOK COVERS ALL OF CENTRAL AND
NORTHEAST MISSOURI AS WELL AS PARTS OF THE STL METRO. STILL...MODE
AND SEVERITY OF CONVECTION WILL LIKELY BE DECIDED BY AMOUNT OF
AVAILABLE INSTABILITY. STAY TUNED.
COLD FRONT ASSOCIATED WITH THE STORM WILL MOVE THROUGH SUNDAY
MORNING. COULD SEE SOME LINGERING SHOWERS AHEAD OF THE FRONT...BUT
IT LOOKS LIKE DRY AIR WILL SHUT THE PRECIP OFF SO WILL KEEP POPS OUT
OF THE FORECAST EXCEPT FOR EXTREME EASTERN ZONES FOR NOW. TEMPS
WILL COOL FROM SATURDAY`S HIGHS...BUT THE REALLY COLD AIR WILL STAY
LOCKED UP IN CANADA THIS TIME AS AN UPPER LEVEL RIDGE BUILDS ACROSS
THE WESTERN HALF OF THE U.S. WARM AND DRY CONDITIONS WILL CONTINUE
MONDAY AND TUESDAY UNDER THE INFLUENCE OF THE RIDGE. TEMPS SHOULD
BE AT OR ABOVE NORMAL IN THE 70S. NEXT CHANCE FOR RAIN WILL COME
WEDNESDAY AS ANOTHER SHORTWAVE DIPS INTO THE UPPER MIDWEST WHICH
WILL ALLOW THE LOW LEVEL JET TO RAMP UP OVER THE AREA AHEAD OF A
COLD FRONT.
CARNEY
&&
.AVIATION...
ISSUED AT 1251 PM CDT THU OCT 11 2012
A STRATUS DECK WILL CONTINUE TO EXPAND NORTHEASTWARD THROUGH THIS
AFTERNOON...WITH CIGS EXPECTED TO REMAIN VFR FOR METRO TAF SITES
AND KUIN. HOWEVER...KCOU COULD BOUNCE BETWEEN HIGH END MVFR TO
LOW VFR AS THE THICKER CLOUDCOVER EXPANDS OVER CENTRAL
MISSOURI...WHERE DIURNAL EFFECTS CANNOT EFFECTIVELY ASSIST IN
KEEPING CLOUD BASES MORE ELEVATED. ALONG AND SOUTH OF I-70...CIGS
ARE EXPECTED TO LOWER TO MVFR BY TONIGHT. WINDS WILL REMAIN
SOUTHERLY THROUGH TONIGHT WHEN A COLD FRONT SLIDES SOUTHWARD
ACROSS THE REGION. EXPECT FROPA THROUGH KUIN AOA 03Z...KCOU AOA
04Z...AND METRO TAF SITES A0A 06Z WITH WINDS VEERING TO THE
NORTHWEST. THOUGH THERE IS A CHANCE FOR SOME PRECIPITATION THIS
EVENING MAINLY ALONG AND SOUTH OF I-70...COVERAGE IS EXPECTED TO
BE WIDELY SCATTERED...AND THUS CONFIDENCE IS TOO LOW TO INCLUDE
MENTION IN THE TAFS AT THIS TIME.
SPECIFICS FOR KSTL...
VFR CONDITIONS WITH CLOUDY SKIES THROUGH THIS EVENING WHEN CIGS
ARE EXPECTED TO DROP TO MVFR AROUND 06Z. THERE IS A CHANCE FOR
PRECIPITATION THIS EVENING...THOUGH COVERAGE WILL BE WIDELY
SCATTERED AND THUS HAVE NOT INCLUDED MENTION IN THE TAF. WINDS
WILL VEER TO THE NORTHWEST BEHIND A COLD FRONT TONIGHT AROUND
06Z...THOUGH CIGS ARE EXPECTED TO REMAIN HIGH-END MVFR THROUGH THE
REMAINDER OF THE VALID FORECAST PERIOD.
JP
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 63 47 66 57 / 10 30 10 10
QUINCY 66 39 61 54 / 10 10 5 60
COLUMBIA 64 44 65 57 / 10 50 20 20
JEFFERSON CITY 63 46 65 58 / 20 60 20 20
SALEM 62 46 64 51 / 10 30 10 10
FARMINGTON 58 48 64 55 / 20 70 20 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
619 AM CDT THU OCT 11 2012
.SHORT TERM...
ISSUED AT 311 AM CDT THU OCT 11 2012
(TODAY THROUGH FRIDAY NIGHT)
WARM ADVECTION UNDER WAY OVER SOUTHWEST MISSOURI AT THIS TIME.
CLOUD DECK BETWEEN 5000-8000FT IS MOVING SLOWLY NORTHEAST TOWARD OUR
AREA. CLOUDS SHOULD OVERSPREAD CENTRAL MISSOURI BY LATE MORNING AND
ON INTO EASTERN MISSOURI EARLY IN THE AFTERNOON. EVEN THOUGH PRECIP
HAS YET TO DEVELOP...SHORT-RANGE MODELS CONTINUE TO PRINT OUT PRECIP
DUE TO THE STRONG WARM ADVECTION AND MOISTURE CONVERGENCE ON THE
850MB BAROCLINIC ZONE ACROSS SOUTHERN MISSOURI. FORECAST SOUNDINGS
ARE PRETTY STRONGLY CAPPED THOUGH SO WOULD EXPECT THAT PRECIP WILL
BE PRETTY SCATTERED. HRRR DEVELOPS ISOLATED TO WIDELY SCATTERED
PRECIP...SO THIS JIVES WELL WITH THAT THINKING. WARM ADVECTION WILL
CONTINUE TONIGHT OVER SOUTHERN MISSOURI AND A SUBTLE SHORTWAVE WILL
BRING ANOTHER CANADIAN HIGH AND A SHOT OF COOL AIR DOWN FROM THE
NORTHERN PLAINS INTO MISSOURI TO REINFORCE THE BAROCLINIC ZONE. THE
STRONG BAROCLINICITY AND CONTINUING LOW LEVEL JET COMBINED WITH THE
SHORTWAVE PASSING OVERHEAD SHOULD PRODUCE MORE WIDESPREAD RAIN AND
THUNDERSTORMS. THE LOW LEVEL JET AND MOISTURE CONVERGENCE STAYS
FOCUSED OVER SOUTHERN MISSOURI...SO HAVE BACKED DOWN TO CHANCE POPS
ALONG THE I-70 CORRIDOR TONIGHT BUT KEPT LIKELY DOWN OVER THE
OZARKS. LOW LEVEL JET CHANGES FOCUS TO THE GREAT PLAINS ON FRIDAY
WHICH SHOULD BRING THE RAIN OVER SOUTHEAST MISSOURI TO AN END. THE
AFOREMENTIONED CANADIAN HIGH MOVES OVER THE MID ATLANTIC FRIDAY
NIGHT WHICH TURNS LOW LEVEL FLOW TO THE SOUTH. THIS PUSHES A WARM
FRONT UP THROUGH OUR AREA INTO THE UPPER MIDWEST SETTING THE STAGE
FOR A WARM SATURDAY AND POTENTIALLY SEVERE WEATHER SATURDAY NIGHT.
CARNEY
&&
.LONG TERM...
ISSUED AT 340 AM CDT THU OCT 11 2012(SATURDAY THROUGH WEDNESDAY)
WE SHOULD BE WELL INTO THE WARM SECTOR ON SATURDAY. NAM AND GFS
SHOW 14-16C AT 850MB SATURDAY AFTERNOON SO AM GOING AT OR ABOVE
UPPER RANGE OF GUIDANCE TEMPS. THE SYNOPTIC SETUP REMAINS
FAVORABLE FOR SEVERE WEATHER SATURDAY AFTERNOON AND NIGHT. THE
DETAILS IN THE MODELS ARE VERY SIMILAR AND HAVE BEEN VERY
CONSISTENT. DEEP LAYER SHEAR IN EXCESS OF 50KTS WITH A STRONG
SHORTWAVE AND LOW LEVEL MOISTURE WILL BE IN PLACE. CONVECTION LOOKS
TO DEVELOP OVER EASTERN KANSAS AND SHOULD MOVE INTO MISSOURI DURING
THE LATE AFTERNOON. FOR OUR AREA...BEST CHANCE FOR STORMS WILL BE
SATURDAY NIGHT. DAY 3 SEVERE OUTLOOK COVERS ALL OF CENTRAL AND
NORTHEAST MISSOURI AS WELL AS PARTS OF THE STL METRO. STILL...MODE
AND SEVERITY OF CONVECTION WILL LIKELY BE DECIDED BY AMOUNT OF
AVAILABLE INSTABILITY. STAY TUNED.
COLD FRONT ASSOCIATED WITH THE STORM WILL MOVE THROUGH SUNDAY
MORNING. COULD SEE SOME LINGERING SHOWERS AHEAD OF THE FRONT...BUT
IT LOOKS LIKE DRY AIR WILL SHUT THE PRECIP OFF SO WILL KEEP POPS OUT
OF THE FORECAST EXCEPT FOR EXTREME EASTERN ZONES FOR NOW. TEMPS
WILL COOL FROM SATURDAY`S HIGHS...BUT THE REALLY COLD AIR WILL STAY
LOCKED UP IN CANADA THIS TIME AS AN UPPER LEVEL RIDGE BUILDS ACROSS
THE WESTERN HALF OF THE U.S. WARM AND DRY CONDITIONS WILL CONTINUE
MONDAY AND TUESDAY UNDER THE INFLUENCE OF THE RIDGE. TEMPS SHOULD
BE AT OR ABOVE NORMAL IN THE 70S. NEXT CHANCE FOR RAIN WILL COME
WEDNESDAY AS ANOTHER SHORTWAVE DIPS INTO THE UPPER MIDWEST WHICH
WILL ALLOW THE LOW LEVEL JET TO RAMP UP OVER THE AREA AHEAD OF A
COLD FRONT.
CARNEY
&&
.AVIATION...
ISSUED AT 616 AM CDT THU OCT 11 2012
AREA OF STRATUS CONTINUES TO ADVANCE NORTHEAST AT 15KTS AND WILL
SPREAD ACROSS THE ENTIRE AREA BY MID AFTERNOON. AT THIS POINT
BELIEVE CEILING WILL REMAIN VFR UNTIL TONIGHT...WITH A LOWERING TO
MVFR LEVELS ALONG AND SOUTH OF INTERSTATE 70. APPEARS BEST CHANCES
OF PRECIPITATION WILL REMAIN SOUTH OF THE TERMINALS AT THIS TIME.
WINDS WILL BE SOUTHELRY TODAY WITH A WIND SHIFT TO THE NORTHWEST
TONIGHT AS A COLD FRONT SLIDES SOUTHEAST ACROSS THE FORECAST AREA.
SPECIFICS FOR KSTL...
VFR STRATUS WILL OVERSPREAD THE TERMINAL BY 16Z. CEILING WILL
LOWER TO MVFR LEVELS BY 07Z TONIGHT. BELIEVE RAIN WILL STAY SOUTH
OF TERMINAL AT THIS TIME.
CVKING
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 63 47 66 57 / 20 40 10 10
QUINCY 66 39 63 52 / 10 10 5 50
COLUMBIA 64 44 66 57 / 20 40 20 20
JEFFERSON CITY 63 46 66 57 / 20 40 20 20
SALEM 62 46 64 52 / 10 40 10 10
FARMINGTON 58 48 65 55 / 30 60 20 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
342 AM CDT THU OCT 11 2012
.SHORT TERM...
ISSUED AT 311 AM CDT THU OCT 11 2012
(TODAY THROUGH FRIDAY NIGHT)
WARM ADVECTION UNDER WAY OVER SOUTHWEST MISSOURI AT THIS TIME.
CLOUD DECK BETWEEN 5000-8000FT IS MOVING SLOWLY NORTHEAST TOWARD OUR
AREA. CLOUDS SHOULD OVERSPREAD CENTRAL MISSOURI BY LATE MORNING AND
ON INTO EASTERN MISSOURI EARLY IN THE AFTERNOON. EVEN THOUGH PRECIP
HAS YET TO DEVELOP...SHORT-RANGE MODELS CONTINUE TO PRINT OUT PRECIP
DUE TO THE STRONG WARM ADVECTION AND MOISTURE CONVERGENCE ON THE
850MB BAROCLINIC ZONE ACROSS SOUTHERN MISSOURI. FORECAST SOUNDINGS
ARE PRETTY STRONGLY CAPPED THOUGH SO WOULD EXPECT THAT PRECIP WILL
BE PRETTY SCATTERED. HRRR DEVELOPS ISOLATED TO WIDELY SCATTERED
PRECIP...SO THIS JIVES WELL WITH THAT THINKING. WARM ADVECTION WILL
CONTINUE TONIGHT OVER SOUTHERN MISSOURI AND A SUBTLE SHORTWAVE WILL
BRING ANOTHER CANADIAN HIGH AND A SHOT OF COOL AIR DOWN FROM THE
NORTHERN PLAINS INTO MISSOURI TO REINFORCE THE BAROCLINIC ZONE. THE
STRONG BAROCLINICITY AND CONTINUING LOW LEVEL JET COMBINED WITH THE
SHORTWAVE PASSING OVERHEAD SHOULD PRODUCE MORE WIDESPREAD RAIN AND
THUNDERSTORMS. THE LOW LEVEL JET AND MOISTURE CONVERGENCE STAYS
FOCUSED OVER SOUTHERN MISSOURI...SO HAVE BACKED DOWN TO CHANCE POPS
ALONG THE I-70 CORRIDOR TONIGHT BUT KEPT LIKELY DOWN OVER THE
OZARKS. LOW LEVEL JET CHANGES FOCUS TO THE GREAT PLAINS ON FRIDAY
WHICH SHOULD BRING THE RAIN OVER SOUTHEAST MISSOURI TO AN END. THE
AFOREMENTIONED CANADIAN HIGH MOVES OVER THE MID ATLANTIC FRIDAY
NIGHT WHICH TURNS LOW LEVEL FLOW TO THE SOUTH. THIS PUSHES A WARM
FRONT UP THROUGH OUR AREA INTO THE UPPER MIDWEST SETTING THE STAGE
FOR A WARM SATURDAY AND POTENTIALLY SEVERE WEATHER SATURDAY NIGHT.
CARNEY
&&
.LONG TERM...
ISSUED AT 340 AM CDT THU OCT 11 2012(SATURDAY THROUGH WEDNESDAY)
WE SHOULD BE WELL INTO THE WARM SECTOR ON SATURDAY. NAM AND GFS
SHOW 14-16C AT 850MB SATURDAY AFTERNOON SO AM GOING AT OR ABOVE
UPPER RANGE OF GUIDANCE TEMPS. THE SYNOPTIC SETUP REMAINS
FAVORABLE FOR SEVERE WEATHER SATURDAY AFTERNOON AND NIGHT. THE
DETAILS IN THE MODELS ARE VERY SIMILAR AND HAVE BEEN VERY
CONSISTENT. DEEP LAYER SHEAR IN EXCESS OF 50KTS WITH A STRONG
SHORTWAVE AND LOW LEVEL MOISTURE WILL BE IN PLACE. CONVECTION LOOKS
TO DEVELOP OVER EASTERN KANSAS AND SHOULD MOVE INTO MISSOURI DURING
THE LATE AFTERNOON. FOR OUR AREA...BEST CHANCE FOR STORMS WILL BE
SATURDAY NIGHT. DAY 3 SEVERE OUTLOOK COVERS ALL OF CENTRAL AND
NORTHEAST MISSOURI AS WELL AS PARTS OF THE STL METRO. STILL...MODE
AND SEVERITY OF CONVECTION WILL LIKELY BE DECIDED BY AMOUNT OF
AVAILABLE INSTABILITY. STAY TUNED.
COLD FRONT ASSOCIATED WITH THE STORM WILL MOVE THROUGH SUNDAY
MORNING. COULD SEE SOME LINGERING SHOWERS AHEAD OF THE FRONT...BUT
IT LOOKS LIKE DRY AIR WILL SHUT THE PRECIP OFF SO WILL KEEP POPS OUT
OF THE FORECAST EXCEPT FOR EXTREME EASTERN ZONES FOR NOW. TEMPS
WILL COOL FROM SATURDAY`S HIGHS...BUT THE REALLY COLD AIR WILL STAY
LOCKED UP IN CANADA THIS TIME AS AN UPPER LEVEL RIDGE BUILDS ACROSS
THE WESTERN HALF OF THE U.S. WARM AND DRY CONDITIONS WILL CONTINUE
MONDAY AND TUESDAY UNDER THE INFLUENCE OF THE RIDGE. TEMPS SHOULD
BE AT OR ABOVE NORMAL IN THE 70S. NEXT CHANCE FOR RAIN WILL COME
WEDNESDAY AS ANOTHER SHORTWAVE DIPS INTO THE UPPER MIDWEST WHICH
WILL ALLOW THE LOW LEVEL JET TO RAMP UP OVER THE AREA AHEAD OF A
COLD FRONT.
CARNEY
&&
.AVIATION...
ISSUED AT 1145 PM CDT WED OCT 10 2012
SC OVER N OK/NW AR HAS BEGUN ITS NWD PUSH EARLY THIS EVENING...AND
00Z NAM/GFS REMAIN IN FAIRLY GOOD AGREEMENT THAT VFR CIGS 4-6KFT
WILL MOVE INTO MID MO AFTER 12-14Z TIME FRAME...AND THEN
SPREAD EAST TO THE MISSISSIPPI RIVER BY MIDDAY/EARLY AFTERNOON.
NAM CONTINUES TO SUGGEST CIGS LOWERING WELL INTO MVFR CAT A FEW
HOURS AFTER THE ARRIVAL OF THE 4-6KFT DECK...BUT FOR NOW HAVE
DELAYED THIS A BIT AND HAVE NOT GONE QUITE AS
PESSIMISTIC...LOWERING CIGS TO AROUND 3KFT BY EARLY EVENING ALONG
THE I-70 CORRIDOR. WHILE SOME VERY LIGHT PRECIP CANNOT TOTALLY BE
RULED OUT...CERTAINLY APPEARS THAT BEST COVERAGE WILL BE S OF TAF
SITES SO HAVE KEPT FORECAST DRY FOR NOW.
SPECIFICS FOR KSTL...LITTLE IF ANY CLOUDINESS EXPECTED
OVERNIGHT...BUT INCREASING S FLOW SHOULD ADVECT 6KFT CIGS INTO
THE AREA BY AROUND MIDDAY THURSDAY. THESE CIGS SHOULD GRADUALLY
LOWER...AND MAY APPROACH HIGH END MVFR BY 06Z/12.
TRUETT
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 63 47 66 57 / 20 40 10 10
QUINCY 66 39 63 52 / 10 10 5 50
COLUMBIA 64 44 66 57 / 20 40 20 20
JEFFERSON CITY 63 46 66 57 / 20 40 20 20
SALEM 62 46 64 52 / 10 40 10 10
FARMINGTON 58 48 65 55 / 30 60 20 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
312 AM CDT THU OCT 11 2012
.SHORT TERM...
ISSUED AT 311 AM CDT THU OCT 11 2012
(TODAY THROUGH FRIDAY NIGHT)
WARM ADVECTION UNDER WAY OVER SOUTHWEST MISSOURI AT THIS TIME.
CLOUD DECK BETWEEN 5000-8000FT IS MOVING SLOWLY NORTHEAST TOWARD OUR
AREA. CLOUDS SHOULD OVERSPREAD CENTRAL MISSOURI BY LATE MORNING AND
ON INTO EASTERN MISSOURI EARLY IN THE AFTERNOON. EVEN THOUGH PRECIP
HAS YET TO DEVELOP...SHORT-RANGE MODELS CONTINUE TO PRINT OUT PRECIP
DUE TO THE STRONG WARM ADVECTION AND MOISTURE CONVERGENCE ON THE
850MB BAROCLINIC ZONE ACROSS SOUTHERN MISSOURI. FORECAST SOUNDINGS
ARE PRETTY STRONGLY CAPPED THOUGH SO WOULD EXPECT THAT PRECIP WILL
BE PRETTY SCATTERED. HRRR DEVELOPS ISOLATED TO WIDELY SCATTERED
PRECIP...SO THIS JIVES WELL WITH THAT THINKING. WARM ADVECTION WILL
CONTINUE TONIGHT OVER SOUTHERN MISSOURI AND A SUBTLE SHORTWAVE WILL
BRING ANOTHER CANADIAN HIGH AND A SHOT OF COOL AIR DOWN FROM THE
NORTHERN PLAINS INTO MISSOURI TO REINFORCE THE BAROCLINIC ZONE. THE
STRONG BAROCLINICITY AND CONTINUING LOW LEVEL JET COMBINED WITH THE
SHORTWAVE PASSING OVERHEAD SHOULD PRODUCE MORE WIDESPREAD RAIN AND
THUNDERSTORMS. THE LOW LEVEL JET AND MOISTURE CONVERGENCE STAYS
FOCUSED OVER SOUTHERN MISSOURI...SO HAVE BACKED DOWN TO CHANCE POPS
ALONG THE I-70 CORRIDOR TONIGHT BUT KEPT LIKELY DOWN OVER THE
OZARKS. LOW LEVEL JET CHANGES FOCUS TO THE GREAT PLAINS ON FRIDAY
WHICH SHOULD BRING THE RAIN OVER SOUTHEAST MISSOURI TO AN END. THE
AFOREMENTIONED CANADIAN HIGH MOVES OVER THE MID ATLANTIC FRIDAY
NIGHT WHICH TURNS LOW LEVEL FLOW TO THE SOUTH. THIS PUSHES A WARM
FRONT UP THROUGH OUR AREA INTO THE UPPER MIDWEST SETTING THE STAGE
FOR A WARM SATURDAY AND POTENTIALLY SEVERE WEATHER SATURDAY NIGHT.
CARNEY
&&
.AVIATION...
ISSUED AT 1145 PM CDT WED OCT 10 2012
SC OVER N OK/NW AR HAS BEGUN ITS NWD PUSH EARLY THIS EVENING...AND
00Z NAM/GFS REMAIN IN FAIRLY GOOD AGREEMENT THAT VFR CIGS 4-6KFT
WILL MOVE INTO MID MO AFTER 12-14Z TIME FRAME...AND THEN
SPREAD EAST TO THE MISSISSIPPI RIVER BY MIDDAY/EARLY AFTERNOON.
NAM CONTINUES TO SUGGEST CIGS LOWERING WELL INTO MVFR CAT A FEW
HOURS AFTER THE ARRIVAL OF THE 4-6KFT DECK...BUT FOR NOW HAVE
DELAYED THIS A BIT AND HAVE NOT GONE QUITE AS
PESSIMISTIC...LOWERING CIGS TO AROUND 3KFT BY EARLY EVENING ALONG
THE I-70 CORRIDOR. WHILE SOME VERY LIGHT PRECIP CANNOT TOTALLY BE
RULED OUT...CERTAINLY APPEARS THAT BEST COVERAGE WILL BE S OF TAF
SITES SO HAVE KEPT FORECAST DRY FOR NOW.
SPECIFICS FOR KSTL...LITTLE IF ANY CLOUDINESS EXPECTED
OVERNIGHT...BUT INCREASING S FLOW SHOULD ADVECT 6KFT CIGS INTO
THE AREA BY AROUND MIDDAY THURSDAY. THESE CIGS SHOULD GRADUALLY
LOWER...AND MAY APPROACH HIGH END MVFR BY 06Z/12.
TRUETT
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 63 47 66 57 / 20 40 10 10
QUINCY 66 39 63 52 / 10 10 5 50
COLUMBIA 64 44 66 57 / 20 40 20 20
JEFFERSON CITY 63 46 66 57 / 20 40 20 20
SALEM 62 46 64 52 / 10 40 10 10
FARMINGTON 58 48 65 55 / 30 60 20 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1223 AM CDT THU OCT 11 2012
...UPDATE TO AVIATION...
.UPDATE...
A FEW CHANGES HAVE BEEN MADE TO THE FORECAST FOR THE OVERNIGHT AND
THURSDAY MORNING PERIODS.
FIRST OFF...CURRENT TEMPERATURES ACROSS MUCH OF THE FORECAST AREA
ARE NEARING PREVIOUSLY FORECASTED LOWS. MOSTLY CLEAR SKIES...LIGHT
WINDS...AND DEW POINTS WELL DOWN IN THE 30S HAVE RESULTED IN
TEMPERATURES DROPPING OFF VERY QUICKLY THIS EVENING. INCREASING
WINDS FROM THE SOUTH ALONG WITH INCREASING CLOUDS WILL STEADY
TEMPERATURES OFF LATER TONIGHT ACROSS THE EASTERN OZARKS...WITH
TEMPERATURES LIKELY RISING ACROSS WESTERN MISSOURI AND
SOUTHEASTERN KANSAS. NEVERTHELESS...LOWS OVER MOST LOCATIONS WERE
BUMPED DOWN A CATEGORY.
THE SECOND TWEAK TO THE FORECAST WAS TO ADD A SLIGHT CHANCE FOR
THUNDER IN FOR LATE TONIGHT ACROSS SOUTHWESTERN MISSOURI AND
SOUTHEASTERN KANSAS. BOTH THE 00Z NAM AND RAP INDICATE LITTLE
CONVECTIVE INHIBITION LATE TONIGHT FOR SOURCE PARCELS IN THE 800
TO 700 MB LAYER. THESE MODELS ALSO INDICATE THAT ISENTROPIC
UPGLIDE WILL OVERSPREAD THIS GENERAL AREA LATE TONIGHT AS A LOW
LEVEL JET NOSES IN FROM THE SOUTHWEST. GENERALLY KEPT POPS IN THE
SLIGHT CHANCE RANGE FOR NOW AS REGIONAL RAOBS INDICATE THAT THERE
IS WORK TO BE DONE TO OVERCOME A CAPPING INVERSION CENTERED AROUND
750 MB. WE THEN WENT WITH SLIGHTLY HIGHER POPS ACROSS SOUTHERN
MISSOURI FOR THURSDAY MORNING. OTHERWISE...THE SETUP STILL LOOKS
DECENT FOR AT LEAST PATCHY DRIZZLE AS LOW LEVEL MOISTURE SURGES UP
FROM THE SOUTH.
SCHAUMANN
&&
.SHORT TERM (TONIGHT THROUGH SATURDAY)...
THE FORECAST FOR THE NEXT SEVERAL DAYS LOOKS TO BE A BIT OF A MESS
WITH THE POTENTIAL FOR DRIZZLE...RAIN AND THUNDERSTORMS SOME OF
WHICH COULD BE STRONG TO SEVERE.
FOR THE REMAINDER OF TODAY HOWEVER...THE REGION WILL SEE SUNNY
SKIES AND COOL AFTERNOON TEMPERATURES. THIS IS THE RESULT OF
CANADIAN HIGH PRESSURE OVER THE REGION. THE COOL TEMPERATURES ARE
EXPECTED TO REMAIN THROUGH TONIGHT ACROSS CENTRAL MISSOURI AS THE
HIGH PRESSURE SLIDES EAST WITH OVERNIGHT LOW FALLING INTO THE
UPPER 30S.
FOR SOUTHWESTERN MISSOURI AND SOUTHEASTERN KANSAS...SOUTHERLY
FLOW IS EXPECTED TO BEGIN OVERNIGHT AS THE HIGH PRESSURE MOVES
EAST. FAIRLY STRONG WARM AIR AND MOISTURE ADVECTION WILL BE
ONGOING AFTER MIDNIGHT ACROSS THE WESTERN PORTION OF THE AREA AND
KEEP OVER NIGHT LOW TEMPERATURES IN THE LOWER 40S. THE STRENGTH
OF THE MOISTURE AND WARM AIR ADVECTION COMBINED WITH 30KTS OF
ISENTROPIC UPGLIDE...NOTED ON THE NAM...ACROSS THE REGION WILL
PRODUCE PRECIPITATION ACROSS THE AREA FROM SOUTHWEST TO NORTHEAST
STARTING AROUND 09Z. THE SHALLOW NATURE OF THE MOISTURE
HOWEVER...ALL BELOW 700MB AND A CAPPING INVERSION...WOULD INDICATE
DRIZZLE AND SHOWERS SHOULD BE MAIN CONCERN. THIS WILL CONTINUE
INTO THE MIDDLE OF THE DAY WITH LIGHT SHOWERS AND DRIZZLE BEING
MODERATE AT TIMES.
A COLD FRONT WILL SLIDE SOUTH ACROSS THE OZARKS THURSDAY NIGHT
INTO FRIDAY AND FINALLY STALL ACROSS THE MISSOURI/ARKANSAS STATE
LINE. THIS WILL PROVIDE THE FOCUS FOR SHOWERS AND SCATTERED
THUNDERSTORMS FROM LATE THURSDAY NIGHT THROUGH FRIDAY EVENING.
CURRENT MODELS ARE INDICATING SOME DECENT LAPSE RATES AND
INSTABILITY WITH THE FRONT THURSDAY NIGHT. THIS WILL ALLOW FOR THE
DEVELOPMENT OF SOME SCATTERED STRONG TO SEVERE STORMS MAINLY ALONG
AND SOUTH OF INTERSTATE 44. CURRENT INDICATION ARE FOR THE
STRONGEST STORMS TO BE CAPABLE OF PRODUCING HAIL TO QUARTER SIZE
AND LOCALIZED DOWNBURST WINDS.
SHOWERS AND STORMS SHOULD REMAIN SCATTERED INTO MIDDAY FRIDAY AS
THE FRONT BRIEFLY SLIDES SOUTH IN ADVANCE OF A STRONG STORM SYSTEM
THAT BEGINS TO SWING OUT OF THE SOUTHWESTERN CONUS AND INTO THE
CENTRAL PLAINS.
HATCH
&&
.LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY)...
BIGGEST FORECAST CHALLENGE FOR LATE SATURDAY AND SATURDAY NIGHT IS
THE POTENTIAL FOR SEVERE THUNDERSTORMS. HIGHLY ENERGETIC STORM
SYSTEM WILL LIFT OUT OF THE CENTRAL ROCKIES AND MOVE TOWARD THE
UPPER MIDWEST/WESTERN GREAT LAKES REGION WITH A NEUTRAL TILT
ORIENTATION. THERE WILL NO DOUBT BE STRONG WIND FIELDS ASSOCIATED
WITH THIS SYSTEM...A 50 KT LOW LEVEL JET...70+ KT MID LEVEL
JET...A 100 KT UPPER LEVEL JET...AND DEEP LAYER SHEAR IN EXCESS OF
60KT. HOWEVER...INSTABILITY VALUES REMAIN A CONCERN. THE DEPTH OF
MOISTURE RETURN IS IN QUESTION...THOUGH SURFACE DEWPOINT VALUES
IN THE 60F TO 65F RANGE ALONG/AHEAD OF THE SURGING COLD FRONT
SHOULD YIELD A NARROW BAND OF 500 TO 1000 J/KG OF MLCAPE BY LATE
AFTERNOON SATURDAY FROM WESTERN IOWA SOUTHWESTWARD THROUGH NORTH
CENTRAL TEXAS. 12Z MODEL OUTPUT HAS ONCE AGAIN SLOWED THE
PROGRESSION OF THIS SYSTEM A BIT...WITH TIME OF ARRIVAL MORE SO
IN THE SATURDAY EVENING TIME FRAME FOR THE OUTLOOK AREA. AS A
RESULT...LOSS OF DAYTIME HEATING WILL AT LEAST CAP...IF NOT LIMIT
INSTABILITY VALUES A LITTLE.
NEVERTHELESS...STRONG FORCING WILL HELP YIELD A LINEAR STORM MODE
ALONG THE COLD FRONT AS IT MOVES INTO THE REGION. HIGH SHEAR...LOW
CAPE ENVIRONMENT SUGGESTS STRAIGHT LINE WIND AS A PRIMARY RISK...
WHICH IS FURTHER SUPPORTED BY VERY STRONG WIND FIELDS JUST OFF THE
SURFACE. THE RISK FOR HAIL/TORNADOES IS IN QUESTION AND IT WILL
MOST LIKELY REQUIRE OBSERVING HOW MESOSCALE CONDITIONS UNFOLD TO
HONE IN ON ANY RISK. FOR NOW...CANNOT RULE IT OUT...BUT WOULD LIKE
TO SEE MORE IN THE WAY OF MLCAPE AS WELL AS LOW LEVEL CAPE.
CERTAINLY THIS SYSTEM BEARS WATCHING.
FROM SUNDAY NIGHT THROUGH EARLY TUESDAY...QUIET WEATHER IS
EXPECTED AS SHORTWAVE RIDGING ALOFT BRIEFLY TAKES HOLD IN AN
INCREASING ACTIVE UPPER LEVEL PATTERN. TEMPERATURES WILL BE AROUND
AVERAGE DURING THIS TIME FRAME. FROM LATE TUESDAY THROUGH THE
MIDDLE OF NEXT WEEK...MEDIUM RANGE MODEL OUTPUT CONTINUES TO
SUGGEST ANOTHER FRONTAL PASSAGE AND CHANCE FOR RAINFALL.
TEMPERATURES LOOK TO REMAIN SEASONABLY MILD.
GAGAN
&&
.AVIATION...
CEILINGS WILL CONTINUE TO LOWER OVERNIGHT AND INTO THURSDAY
MORNING AS MOISTURE INCREASES FROM THE SOUTH. WE HAVE DELAYED MVFR
ONSET A FEW HOURS BUT ARE STILL EXPECTING IT TO COME INTO SOUTHERN
MISSOURI AROUND SUNRISE. WE ARE ALSO EXPECTING PATCHY DRIZZLE TO
DEVELOP...WHICH MAY CAUSE SLIGHT REDUCTION TO VISIBILITY. THERE IS
ALSO A LOW PROBABILITY FOR A THUNDERSTORM OR TWO TO DEVELOP AROUND
SUNRISE AS A LOW LEVEL JET STREAM SHIFTS INTO THE REGION. DID NOT
INCLUDE THIS THREAT IN THE TAFS DUE TO LOW CONFIDENCE. THE LOW
LEVEL JET STREAM WILL ALSO RESULT IN LOW LEVEL WIND SHEAR THURSDAY
MORNING. MVFR CEILINGS ARE THEN EXPECTED TO PERSIST FOR MUCH OF
THE DAY ON THURSDAY WITH PERHAPS SOME PARTIAL CLEARING LATE IN THE
DAY. SHOWERS AND THUNDERSTORMS ALONG WITH MVFR CONDITIONS ARE THEN
EXPECTED TO DEVELOP THURSDAY EVENING AS A COLD FRONT DROPS SOUTH
INTO SOUTHERN MISSOURI.
SCHAUMANN
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1148 PM MDT WED OCT 10 2012
.AVIATION...
06Z TAF CYCLE
NO NOTABLE AVIATION HAZARDS OVERNIGHT FOR NW TWO THIRDS OF FCST
AREA...HOWEVER AS OF JUST BEFORE MIDNIGHT PATCHY MVFR CATEGORY
CIGS SLOWLY EXPANDING ACROSS FAR SE PLAINS. AS MOIST LOW LEVEL FLOW
CONTINUES ACROSS SE AND E CENTRAL PLAINS THIS WILL ENCOURAGE
EXPANSION OF MVFR TO LOCALLY IFR CIGS AND PERHAPS A FEW FOG PATCHES
THROUGH THE EARLY AND MID MORNING HOURS IN AREAS SE OF A LINE FROM
ROUGHLY KTCC TO RUIDOSO. TAF SITES THAT THESE LOW CIGS AND POSS FOG
ARE MOST LIKELY TO AFFECT INCLUDE KROW AND PERHAPS KTCC. THERE IS
A SLIGHT CHANCE THAT AFTER DAWN AND THROUGH GOOD PORTION OF THU
MORN...BUT MORE LIKELY LATE THU...THERE MAY BE SOME MT TOP
OBSCURATIONS ACROSS THE S CENTRAL MTS. ALSO A FEW GUSTY TSRA ARE
POSSIBLE S OF A LINE FROM QUEMADO TO KLVS TO KTCC AFTER 20Z
THU...BUT MOSTLY JUST -SHRA ARE EXPECTED DURING DAYLIGHT HOURS
THU. SPOTTY TSRA WILL BE MORE LIKELY LATER THU NIGHT OVER A LARGER
AREA. 43
&&
.PREV DISCUSSION...955 PM MDT WED OCT 10 2012...
REMOVED POPS THRU THE EARLY MORNING HOURS ACROSS MUCH OF THE SW
MTS AND THE SE PLAINS PER LATEST RUC13 AND 00Z NAM12 SOLUTIONS. 03Z
SATELLITE IMAGERY IS BEGINNING TO SHOW LOW CLOUD DEVELOPMENT OVER
FAR SE NM WHERE LOW LEVEL MOISTURE ADVECTION IS SURGING NW INTO THE
AREA. BUFKIT PROFILES DO FAVOR SOME THICK LOW CLOUDS AND PATCHY FOG
DEVELOPMENT FOR THE PECOS RIVER VALLEY AND SE PLAINS.
SW FLOW AHEAD OF A DEEP UPPER LOW OVER SOCA IS SHOWING SIGNS OF
MOISTENING FROM SOUTH TO NORTH TOWARD NM HOWEVER PRECIP WILL LIKELY
HOLD OFF UNTIL AROUND SUNRISE. ALSO MADE CHANGES TO HIGHEST POPS
FOR THURSDAY THRU FRIDAY MORE IN LINE WITH HPC PROBABILISTIC QPF
GRIDS AND THE LATEST NAM. THE OVERALL SCENARIO REMAINS ON TRACK.
EXPECT THE MOST ACTIVE PERIOD OF PRECIP FROM EARLY FRIDAY MORNING
THRU FRIDAY AFTERNOON AS SIGNIFICANT UPPER DIVERGENCE ALLOWS AN
AREA OF RAIN/STORMS TO DEVELOP ACROSS THE STATE AND SHIFT NORTHEAST
THRU THE DAY WHILE THE PACIFIC FRONT APPROACHES FROM THE WEST. STRONG
TO POTENTIALLY SEVERE STORMS ARE POSSIBLE TOWARD THE TX STATE LINE
FRIDAY. GUYER
&&
.PREV DISCUSSION...307 PM MDT WED OCT 10 2012...
CURRENTLY...RIDGE ALOFT EXTENDING FROM THE TEXAS BIG BEND COUNTRY
SQUARELY ACROSS NEW MEXICO TO GREAT SALT LAKE...AHEAD OF LARGE
WEATHER SYSTEM COILED UP OFF POINT CONCEPCION IN SOUTHERN
CALIFORNIA EN ROUTE TO THE SAN DIEGO AREA. AT THE
SURFACE...STATIONARY BOUNDARY LYING FROM TAOS TO WHITE SANDS
MISSILE RANGE STANDS AS LAST GASP FOR COLD FRONT WHICH DIPPED INTO
THE EASTERN PLAINS OVER THE LAST 24 HOURS. ADVANCING STORM SYSTEM
TOUCHING OFF LIGHTNING STRIKES ACROSS SOUTHERN NEVADA AND SOUTHERN
UTAH...AND ALL THIS IS HEADING FOR NEW MEXICO OVER THE NEXT 48 HOURS.
MODELS...IN GOOD AGREEMENT THROUGH THE UPCOMING WEEKEND AND INTO
NEXT WORK WEEK...WITH SOME MODEST DIFFERENCES EMERGING FROM
TUESDAY ONWARD IN THE DETAILS WITHIN BROADER AGREEMENT ON THE
GENERAL THEME. PLAUSIBLE AND ACCEPTED CONSENSUS MOVES CALIFORNIA
CLOSED LOW TO SAN DIEGO LATE THURSDAY NIGHT AND TO THE FOUR
CORNERS BY FRIDAY AFTERNOON. SYSTEM WILL EJECT RAPIDLY TO THE
PLATTE RIVER VALLEY OF CENTRAL NEBRASKA BY SATURDAY MIDDAY AND
RAPIDLY INTO THE WESTERN GREAT LAKES BY SUNDAY MORNING. EJECTION
SPEED WILL VEER FLOW ALOFT RAPIDLY TO THE NORTHWEST DURING THE DAY
ON SATURDAY...AND SOME FORM OF NORTHWEST FLOW IS IN THE CARDS FOR
NEW MEXICO THROUGH MIDWEEK NEXT WEEK AS RIDGE CORE SETS UP OVER
THE TROPICAL EAST PACIFIC. FROM TUESDAY ONWARD...DOMESTIC GFS
SOLUTION PREFERS A MORE LAMINAR AND STEADY NORTHWEST FLOW RUNNING
JUST NORTH OF NEW MEXICO...WHILE EUROPEAN COLLEAGUES AT ECMWF DIG
BROAD TROUGH OUT OF THE CANADIAN PRAIRIES ACROSS NEW MEXICO TO THE
GULF OF CALIFORNIA...AND THEN MOVES THIS TROUGH INTO THE SOUTHERN
PLAINS BY MIDWEEK. UPSHOT FOR NEW MEXICO WOULD BE A CLOUDIER DAY
WITH SOME ENHANCED SHOWER CHANCES TUESDAY UNDER THE ECMWF
SOLUTION...WITH A DRY AND COOL DAY FOR THE GFS. ECMWF HAS BEEN
DIGGING THESE TROUGHS INTO THE SOUTHWEST FOR THE LAST SEVERAL
STORMS THAT HAVE COME THROUGH...BUT THESE HAVE NOT VERIFIED AS
DEEPLY AS THE ECMWF SOLUTION WOULD SUGGEST. WILL THUS KEEP A LEAN
TOWARD GFS IN THE EXTENDED PERIODS FOR NOW AND AWAIT A BETTER
CONSENSUS IN FUTURE RUNS.
OVERNIGHT...REASONABLY SEASONABLE OVERNIGHT TEMPERATURES
TONIGHT...WITH FREEZES MOSTLY OVER THE NORTHERN MOUNTAINS AND MORE
MILD TEMPERATURES ELSEWHERE. AS RIDGE BREAKS DOWN AND SHIFTS
EASTWARD...SOME ISOLATED THUNDERSTORMS REMAIN A POSSIBILITY OVER
THE SOUTHEAST CORNER OF THE STATE...AS THE FIRST OF THE SOUTHWEST
WINDS CIRCULATING ABOUT THE APPROACHING WEATHER SYSTEM PUSH SOME
DYNAMICAL HELP OVER THE EXISTING MOISTURE. OUTSIDE OF CONVECTIVE
SHOWERS...SOME VISIBILITY REDUCTIONS IN PATCHY FOG ARE POSSIBLE
TOWARDS DAYBREAK...ESPECIALLY NEAR THE TEXAS PANHANDLE ALONG AND
SOUTH OF INTERSTATE 40.
FOR THURSDAY...STORM CENTER APPROACHING SAN DIEGO THURSDAY MORNING
WILL DRIFT INTO THE IMPERIAL AND MOJAVE DESERT COUNTRY OF INLAND
SOUTHERN CALIFORNIA BY THURSDAY EVENING. DIFFLUENT SOUTHWEST FLOW
ACROSS NEW MEXICO WILL EXPAND CLOUD AND SHOWER COVERAGE RAPIDLY
THROUGH THE DAY...WITH HEAVIER SHOWERS SETTING UP OVER THE EAST
CENTRAL PLAINS BY THURSDAY AFTERNOON. SHOWER COVERAGE WILL EXPAND
IN COVERAGE AND INCREASE IN INTENSITY THURSDAY NIGHT...WITH
HEAVIER RAINFALL BUILDING ACROSS THE ARIZONA AND COLORADO LINES IN
THE NORTH AND WEST...AND MORE WIDESPREAD SHOWERS ON TAP FOR THE
EAST. WARM MOIST AIR MOVING INTO THE PLAINS WILL BRING DAYTIME
HIGH TEMPERATURES BACK UP ABOVE NORMAL...WITH NEAR NORMAL
TEMPERATURES IN THE WEST. ADDED CLOUD COVER AND RAINFALL WILL KEEP
OVERNIGHT LOWS MILD.
FOR FRIDAY...THE MAIN EVENT PLAYING OUT...AS STORM CENTER MOVES
FROM SOUTHEAST CALIFORNIA TO THE FOUR CORNERS. SOUTHWEST WINDS
WILL GET AN EARLY BOOST IN SPEEDS IN THE WEST FRIDAY MORNING WITH
GUSTY WINDS SPREADING TO CENTRAL PORTIONS BY MIDDAY AND EXPANDING
INTO THE NORTHEAST PLAINS BY LATE AFTERNOON. FORECAST WINDS
CURRENTLY CROSSING ADVISORY THRESHOLDS BY MID AFTERNOON WITH
SPEEDS TAPERING OFF THROUGH FRIDAY EVENING. A WET DAY IN THE
CARDS...WITH HEAVIEST RAINFALL OVER THE NORTHEAST PLAINS AND
ADJACENT HIGHLANDS THROUGH FRIDAY EVENING. RAPIDLY DEEPENING
SURFACE TROUGH ALONG THE NEW MEXICO EASTERN BORDER WILL SET UP
SURFACE CONVERGENCE...AND WITH AMPLE DYNAMICS IN
PLACE...THUNDERSTORMS NEAR THE TEXAS PANHANDLE FRIDAY AFTERNOON
MAY RUN TO THE STRONG WIDE WITH HAIL AND POSSIBLY DAMAGING WIND.
AND THATS NOT ALL...AS COLDER AIR MOVING IN OVER THE NORTHERN
MOUNTAINS MAY CHANGE RAIN OVER TO AN INCH OR TWO OF WET SNOW
OVERNIGHT FOR THE SAN JUAN...SANGRE DE CRISTO...AND JEMEZ SUMMITS
AND HIGH COUNTRY SLOPES...WITH SOME LESSER AMOUNTS OVER THE
CHUSKAS AND SOME OF THE HIGHER SPOTS ON THE CONTINENTAL DIVIDE.
ACCUMULATIONS WILL BE VISIBLE BUT NOT ESPECIALLY LARGE...WITH SNOW
GETTING A LATE START OVERNIGHT AND FALLING ON RELATIVELY WARM
SURFACES.
FOR SATURDAY...STORM CENTER MOVING RAPIDLY TO NORTHEAST COLORADO
SATURDAY MORNING AND TO THE MISSOURI RIVER VALLEY BY SATURDAY
AFTERNOON. COLD FRONT BARRELING SOUTHWARD IN WAKE OF THE STORM
WILL KEEP DAYTIME HIGH TEMPERATURES 3 TO 8 DEGREES BELOW NORMAL
CENTRAL AND WEST...AND NEAR NORMAL IN THE EXTREME EAST. SHOWER
COVERAGE AND SKIES WILL CLEAR RAPIDLY FROM SOUTHWEST TO NORTHEAST
DURING THE DAY WITH BREEZES CONTINUING OVER THE CENTRAL MOUNTAIN
CHAIN SUMMITS...AND ALONG THE INTERSTATE 40 CORRIDOR ACROSS THE
EASTERN PLAINS.
OUTLOOK...SUNDAY THROUGH TUESDAY...NORTHWEST FLOW MOVING FROM
NORTHERN CALIFORNIA ACROSS THE NORTHEAST HALF OF NEW MEXICO AND
INTO THE DEEP SOUTH SUNDAY WILL CLEAR SKIES AND ALLOW MODEST
WARMING TREND TO TAKE HOLD FOR THE WORK WEEK START...AS SURFACE HIGH
PRESSURE BUILDS INTO THE NORTHWEST HALF OF NEW MEXICO. WARMING
WILL BRING TEMPERATURES 6 TO 12 DEGREES ABOVE NORMAL OVER THE
EASTERN PLAINS...WITH TEMPERATURES CLOSER TO NORMAL CENTRAL AND
WEST. COLD FRONT DROPPING SOUTHWARD WILL RUN TO THE WEAK SIDE AND
LEVEL OFF TEMPERATURES ON MONDAY. COOLER AIR IN PLACE FOR
TUESDAY...WITH SOME AFTERNOON BREEZES DEVELOPING ONCE AGAIN OVER
THE EASTERN SLOPES AND ADJACENT PLAINS OF THE CENTRAL MOUNTAIN
CHAIN TUESDAY AFTERNOON. SPEEDY FLOW CLIPPING NORTHERN NEW MEXICO
MAY KICK OFF SOME EVENING SPRINKLES OR FLURRIES OVER THE HIGH
PEAKS LATE TUESDAY NIGHT. SHY
.FIRE WEATHER...
A CHANGE IN CONDITIONS FROM WARM AND DRY TO A MORE ACTIVE PATTERN
IS EXPECTED THURSDAY AND FRIDAY.
A SHORT WAVE RIDGE IS CURRENTLY POSITIONED OVER NEW MEXICO WITH
ABOVE NORMAL TEMPERATURES ACROSS CENTRAL AND WESTERN ZONES AND SOME
COOLER TEMPERATURES ACROSS THE EASTERN PLAINS IN THE WAKE OF A COLD
FRONT. SOME BREEZY AFTERNOON WINDS WILL PERSIST THROUGH EARLY
EVENING AS RH VALUES DIP BELOW 20 PERCENT ACROSS THE WEST. OVERNIGHT
RH RECOVERIES AREA EXPECTED TO BE FAIR ACROSS MUCH OF CENTRAL AND
WESTERN ZONES WITH GOOD TO EXCELLENT VALUES ACROSS THE EAST. LOW
CLOUDS...SOME FOG WITH A SLIGHT CHANCE FOR SOME WETTING RAIN IS
INTRODUCED INTO THE SOUTHEAST PLAIN TONIGHT.
A NEARLY STATIONARY UPPER LEVEL LOW POSITIONED OFF THE CALIFORNIA
COAST IS PROGGED TO MOVE ONSHORE BY LATE THURSDAY. SOUTHWEST FLOW
IN ADVANCE OF THE SYSTEM WILL SUPPORT STRENGTHENING SOUTH TO
SOUTHWEST WINDS ON THURSDAY...ESPECIALLY OVER THE WEST. CHANCES FOR
WETTING RAIN INCREASE AS WELL. VENTILATION INCREASES TO VERY GOOD TO
EXCELLENT MOST ZONES AND TEMPERATURES REBOUND ACROSS THE EAST.
THERE IS REASONABLY GOOD AGREEMENT ON THE TRACK OF THE UPPER LOW
THURSDAY INTO FRIDAY...WITH A SLOW PROGRESSION EAST AND SOUTH ON
THURSDAY WITH BEST JET...LIFT AND MOISTURE AHEAD OF THE SYSTEM.
HOWEVER...MODELS CAN STRUGGLE WITH THE SPEED OF THE UPPER LOW AND
SOME DRY AIR AHEAD OF THE LOW WILL MAKE THE FORECAST A LITTLE TRICKY
AS WELL. MODELS MOVE THE UPPER LOW TO THE NORTHEAST ON FRIDAY WITH A
TIGHT GRADIENT AND STRONG JET OVER NEW MEXICO. WINDS SHOULD BE THE
STRONGEST ON FRIDAY...WITH A SIGNIFICANT WIND EVENT POSSIBLE...BUT
CURRENT GRIDS MAINTAIN RH WELL ABOVE CRITICAL VALUES. THE BEST
CHANCES FOR WETTING RAIN LOOK TO BE THE NORTH AND EXTREME EAST WHERE
STRONG THUNDERSTORMS ARE POSSIBLE.
MODELS MOVE THE LOW MORE RAPIDLY TO THE NORTHEAST ON SATURDAY...WITH
THE LOW CENTERED NEAR OR OVER NEBRASKA BY MIDDAY. UNDER DEVELOPING
NORTHWEST FLOW ALOFT...COOLER AND MUCH DRIER AIR FILTERS IN OVER THE
STATE.
WARMER AND MOSTLY DRIER CONDITIONS CONTINUE INTO SUNDAY WITH
A WEAKENING GRADIENT AND MUCH LIGHTER WINDS. VENTILATION VALUES LOOK
TO BE POOR TO FAIR.
EXTENDED MODELS MAINTAIN NORTHWEST FLOW AT LEAST THROUGH MID WEEK
WITH DRY AND SEASONABLE WARM TEMPERATURES EXPECTED. 05
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
43
AREA FORECAST DISCUSSION
NWS BISMARCK ND
309 PM CDT THU OCT 11 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT...
THE HIGHLIGHT OF THE SHORT TERM IS THE POTENTIAL FOR CRITICAL FIRE
WEATHER CONDITIONS ON FRIDAY.
FOR TONIGHT...SURFACE HIGH PRESSURE WILL QUICKLY PROPAGATE ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. SOUTHEASTERLY RETURN FLOW WILL
COMMENCE BY 5-6 UTC AND STRENGTHEN THROUGH THE NIGHT...SLOWING THE
TEMPERATURE FALL ONLY INTO THE UPPER 20S TO THE LOWER 30S.
FOR FRIDAY...STRONG SOUTHERLY FLOW IS FORECAST AHEAD OF A WARM
FRONT THAT WILL PROPAGATE INTO FAR WESTERN NORTH DAKOTA BY THE LATE
AFTERNOON. BORDERLINE WIND ADVISORY CRITERIA IS POSSIBLE FOR THE
CENTRAL WITH GUSTS TO 35 KTS WITH ISALLOBARIC FORCING FROM
PRESSURE FALLS ON THE ORDER OF 9 MB/ 6 HR ENHANCING THE GRADIENT
FLOW AND MIXING. LOWER MIXING HEIGHTS AHEAD OF THE WARM FRONT WILL
LIMIT HIGH TEMPERATURES ACROSS CENTRAL NORTH DAKOTA INTO THE 55-60
DEGREE RANGE. HOWEVER...HIGHS IN THE MID TO UPPER 60S ARE POSSIBLE
ACROSS THE FAR WEST BEHIND THE WARM FRONT AS WINDS TRANSITION TO
THE SOUTHWEST. GIVEN THE AFOREMENTIONED CONDITIONS...CRITICAL FIRE
WEATHER CONDITIONS MAY BE POSSIBLE ACROSS PORTIONS OF CENTRAL
NORTH DAKOTA ON FRIDAY AND ISSUED A FIRE WEATHER WATCH. SEE THE
FIRE WEATHER DISCUSSION BELOW FOR DETAILS.
.LONG TERM...SATURDAY THROUGH THURSDAY...
THE START OF THE LONG TERM PERIOD WILL FEATURE AN H5 WAVE MOVING
FROM THE CENTRAL PLAINS INTO THE UPPER GREAT LAKES. PRECIPITATION
FROM THIS SYSTEM COULD STILL TRY TO CLIP THE FAR SOUTHEAST PART OF
THE FORECAST AREA...BUT OVERALL IT APPEARS THE BULK OF FORECAST
AREA WILL REMAIN DRY AS IT PASSES.
A SERIES OF WAVES WILL MOVE ACROSS THE NORTHERN PLAINS/SOUTHERN
CANADA FROM SUNDAY INTO THE MIDDLE OF NEXT WEEK. THE ALL BLEND
MODEL SOLUTION HOLDS ONTO SMALL CHANCES OF RAIN IN THE EXTREME
NORTHERN PORTION OF THE FORECAST AREA ON SUNDAY...THOUGH ITS
ENTIRELY POSSIBLE THE MAIN CHANCES COULD STAY JUST NORTH OF THE
BORDER IN CANADA.
A WAVE FOR MONDAY NIGHT APPEARS TO BRING RAIN CHANCES TO A LARGER
PORTION OF THE FORECAST AREA...BUT ALL BLEND POPS REMAIN ONLY IN THE
SLIGHT CHANCE CATEGORY. A BETTER CHANCE OF RAIN APPEARS TO ARRIVE
TUESDAY INTO WEDNESDAY AS THE LEFT FRONT QUADRANT OF THE UPPER JET
SHIFTS ACROSS NORTH DAKOTA IN ASSOCIATION WITH A STRONGER H5 WAVE.
THIS WAVE ALSO HELPS USHER A COLD FRONT THROUGH THE FORECAST AREA
WITH GUSTY NORTHWEST WINDS EXPECTED BEHIND THE BOUNDARY. H85
TEMPERATURES APPROACH OR FALL JUST BELOW FREEZING ON WEDNESDAY...BUT
LOW LEVEL TEMPERATURES STILL APPEAR TOO WARM FOR SNOW.
&&
.AVIATION...
ISOLATED MVFR CEILINGS REMAIN ACROSS PARTS OF WESTERN
NORTH DAKOTA...BUT NOW THAT THE TERMINAL LOCATIONS HAVE GONE BACK TO
VFR...WILL LEAVE THEM THERE FOR THE AFTERNOON. RAP BUFR SOUNDINGS
SUGGEST VFR CEILINGS AROUND 4KFT COULD PERSIST FOR MUCH OF THE
AFTERNOON...BUT THOSE ARE EXPECTED TO CLEAR THIS EVENING. WINDS
WILL CONTINUE TO BECOME LIGHT THIS AFTERNOON / EVENING AS SURFACE
HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS. WINDS WILL BECOME
SOUTHERLY LATER THIS EVENING AS THE HIGH SLIDES EAST INTO
MINNESOTA. A TIGHT PRESSURE GRADIENT ON FRIDAY COMBINED WITH
SUFFICIENT MIXING WILL ALLOW WIND SPEEDS TO INCREASE AND BECOME
GUSTY SHORTLY AFTER SUNRISE.
&&
.FIRE WEATHER...
ISSUED A FIRE WEATHER WATCH FOR SOUTH CENTRAL NORTH DAKOTA AND THE
JAMES RIVER VALLEY FOR FRIDAY. STRONG SOUTHERLY WINDS IN EXCESS
OF 30 MPH ARE FORECAST TO DEVELOP ACROSS SOUTH CENTRAL NORTH
DAKOTA AND THE JAMES RIVER VALLEY LATE FRIDAY MORNING THROUGH
EARLY EVENING. AFTERNOON HIGH TEMPERATURES OF 55 TO 60 ARE
EXPECTED...WITH RELATIVE HUMIDITY VALUES FALLING TO NEAR 25
PERCENT. WHEN COMBINED WITH ABUNDANT DRY FUELS...VERY HIGH FIRE
DANGER AND RAPID FIRE GROWTH ARE POSSIBLE FRIDAY. WHILE STRONG
WINDS ARE FORECAST ACROSS THE NORTH CENTRAL...HIGHER RELATIVE
HUMIDITY VALUES WILL LIMIT THE FIRE DANGER.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING
FOR NDZ020-022-023-025-034>037-042-045>048-050-051.
&&
$$
SHORT TERM/FIRE...AYD
LONG TERM/AVIATION...CK
AREA FORECAST DISCUSSION
NWS TULSA OK
1232 PM CDT THU OCT 11 2012
.DISCUSSION...
THE 18Z TAF DISCUSSION CAN BE FOUND BELOW.
&&
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
MVFR CIGS SHOULD INCREASE TO VFR LATER THIS AFTERNOON. LATER ON
TONIGHT...MAINLY AFT 04Z...SCT TSRA ARE EXPTD TO DVLP OVER NE OK
AND NW AR. THE ACTIVITY WILL GRADUALLY BUILD SOUTH AND MAY AFFECT
KFSM AND/OR KMLC TOWARD THE END OF THE TAF PERIOD. MVFR CONDITIONS
ARE LIKELY WITH THIS STORM ACTIVITY.
LACY
&&
.PREV DISCUSSION... /ISSUED 1044 AM CDT THU OCT 11 2012/
DISCUSSION...
LOW LVL MOISTURE RETURN ON THE BACK SIDE OF THE SURFACE HIGH OVER
THE SOUTHEAST STATES HAS RESULTED IN WIDESPREAD LOW CLOUDS. THE
LATEST DATA INDICATES THAT THIS CLOUD COVER WILL STICK AROUND FOR
MUCH OF THE DAY...LIMITING HEATING. I HAVE LOWERED HIGHS TEMPS BY
A CATEGORY IN MOST PLACES. THE LATEST HRRR SUGGESTS THAT THE
MORNING SHOWERS AND ISOLD TSTORMS TO THE SOUTH AND EAST OF TULSA
WILL EVENTUALLY DISSIPATE THIS AFTERNOON AND SHOULD REMAIN QUIET
UNTIL TONIGHT. THUS I HAVE MADE SOME ADJUSTMENT TO THE
POPS...DECREASING THEM IN THE WEST. TEXT PRODUCTS HAVE BEEN SENT.
LACY
PREV DISCUSSION... /ISSUED 556 AM CDT THU OCT 11 2012/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
WIDESPREAD MVFR CIGS SHOULD PERSIST THROUGH THE MORNING
HOURS...ALONG WITH WIDELY SCATTERED SHOWERS MAINLY FOR
THE ARKANSAS TAF SITES. EXPECT CIGS TO RISE TO VFR AFTER
18-20Z. THUNDERSTORM DEVELOPMENT LIKELY AT KBVO/KTUL/KRVS
KFYV AND KXNA AROUND 04-06Z...WITH SEVERE THUNDERSTORMS
POSSIBLE.
PREV DISCUSSION... /ISSUED 323 AM CDT THU OCT 11 2012/
DISCUSSION...
FRONTAL BOUNDARY...CURRENTLY LOCATED ACROSS FAR SOUTHERN ARKANSAS
THIS MORNING...HAS BEGUN TO LIFT BACK NORTH INTO SOUTHEAST
OKLAHOMA THIS MORNING WITH LOW LEVEL MOISTURE INCREASING. ISOLATED
SHOWERS/THUNDERSTORMS MAY DEVELOP LATER THIS MORNING AS THE LOW
LEVEL JET CONTINUES TO INCREASE WITH A LIMITED SEVERE THREAT ALONG
AND NORTH OF THE RETREATING WARM FRONT.
BETTER THUNDERSTORM CHANCES...INCLUDING THE THREAT FOR SEVERE
WEATHER...WILL OCCUR THIS EVENING INTO THE OVERNIGHT HOURS AS A
SECONDARY SURGE OF COOLER AIR MOVES TO THE OKLAHOMA/KANSAS BORDER
AND STALLS. MOISTURE POOLING ALONG THE FRONT WILL ALLOW THE
ATMOSPHERE TO BECOME MODERATELY UNSTABLE WITH 30-40 KNOT DEEP
LAYER SHEAR IN PLACE. LARGE HAIL WILL BE THE PRIMARY THREAT WITH
THE STRONGER STORMS OVERNIGHT...INCLUDING THE THREAT FOR LOCALLY
HEAVY RAINFALL.
MAIN FOCUS THEN SHIFTS TO STRONG UPPER LOW CURRENTLY OFF THE
CALIFORNIA COAST AND ITS POTENTIAL IMPACTS INTO THE WEEKEND. UPPER
LOW WILL QUICKLY LIFT NORTHEAST INTO THE CENTRAL PLAINS BY
SATURDAY. STRONG TO SEVERE THUNDERSTORMS WILL BE LIKELY SATURDAY
AFTERNOON INTO SATURDAY EVENING AS THE COLD FRONT SWEEPS EAST
THROUGH THE AREA. STRONG LOW LEVEL WIND FIELDS WILL DEVELOP AHEAD
OF FRONT AND WITH MODERATE INSTABILITY EXPECTED...ALL MODES OF
SEVERE WEATHER WILL BE POSSIBLE. THE SEVERE THREAT SHOULD END
SUNDAY MORNING AS CONVECTIVE LINE SWEEPS EAST.
FOR THE REMAINDER OF THE FORECAST...WARM/DRY CONDITIONS ARE
GENERALLY EXPECTED. ANOTHER COLD FRONT IS EXPECTED AROUND MID
WEEK...HOWEVER AS IT APPEARS NOW...LIMITED MOISTURE WILL KEEP
PRECIPITATION CHANCES LOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 68 82 66 80 / 80 60 20 80
FSM 65 81 63 82 / 50 30 10 30
MLC 66 83 66 82 / 30 20 10 50
BVO 60 78 63 81 / 80 60 40 80
FYV 60 78 61 82 / 80 60 10 40
BYV 58 74 61 82 / 80 60 10 30
MKO 65 81 64 80 / 60 30 10 50
MIO 61 78 63 81 / 80 60 20 70
F10 66 81 66 81 / 50 30 20 70
HHW 66 84 64 82 / 20 20 10 40
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...30
AREA FORECAST DISCUSSION
NWS TULSA OK
1044 AM CDT THU OCT 11 2012
.DISCUSSION...
LOW LVL MOISTURE RETURN ON THE BACK SIDE OF THE SURFACE HIGH OVER
THE SOUTHEAST STATES HAS RESULTED IN WIDESPREAD LOW CLOUDS. THE
LATEST DATA INDICATES THAT THIS CLOUD COVER WILL STICK AROUND FOR
MUCH OF THE DAY...LIMITING HEATING. I HAVE LOWERED HIGHS TEMPS BY
A CATEGORY IN MOST PLACES. THE LATEST HRRR SUGGESTS THAT THE
MORNING SHOWERS AND ISOLD TSTORMS TO THE SOUTH AND EAST OF TULSA
WILL EVENTUALLY DISSIPATE THIS AFTERNOON AND SHOULD REMAIN QUIET
UNTIL TONIGHT. THUS I HAVE MADE SOME ADJUSTMENT TO THE
POPS...DECREASING THEM IN THE WEST. TEXT PRODUCTS HAVE BEEN SENT.
LACY
&&
.PREV DISCUSSION... /ISSUED 556 AM CDT THU OCT 11 2012/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
WIDESPREAD MVFR CIGS SHOULD PERSIST THROUGH THE MORNING
HOURS...ALONG WITH WIDELY SCATTERED SHOWERS MAINLY FOR
THE ARKANSAS TAF SITES. EXPECT CIGS TO RISE TO VFR AFTER
18-20Z. THUNDERSTORM DEVELOPMENT LIKELY AT KBVO/KTUL/KRVS
KFYV AND KXNA AROUND 04-06Z...WITH SEVERE THUNDERSTORMS
POSSIBLE.
PREV DISCUSSION... /ISSUED 323 AM CDT THU OCT 11 2012/
DISCUSSION...
FRONTAL BOUNDARY...CURRENTLY LOCATED ACROSS FAR SOUTHERN ARKANSAS
THIS MORNING...HAS BEGUN TO LIFT BACK NORTH INTO SOUTHEAST
OKLAHOMA THIS MORNING WITH LOW LEVEL MOISTURE INCREASING. ISOLATED
SHOWERS/THUNDERSTORMS MAY DEVELOP LATER THIS MORNING AS THE LOW
LEVEL JET CONTINUES TO INCREASE WITH A LIMITED SEVERE THREAT ALONG
AND NORTH OF THE RETREATING WARM FRONT.
BETTER THUNDERSTORM CHANCES...INCLUDING THE THREAT FOR SEVERE
WEATHER...WILL OCCUR THIS EVENING INTO THE OVERNIGHT HOURS AS A
SECONDARY SURGE OF COOLER AIR MOVES TO THE OKLAHOMA/KANSAS BORDER
AND STALLS. MOISTURE POOLING ALONG THE FRONT WILL ALLOW THE
ATMOSPHERE TO BECOME MODERATELY UNSTABLE WITH 30-40 KNOT DEEP
LAYER SHEAR IN PLACE. LARGE HAIL WILL BE THE PRIMARY THREAT WITH
THE STRONGER STORMS OVERNIGHT...INCLUDING THE THREAT FOR LOCALLY
HEAVY RAINFALL.
MAIN FOCUS THEN SHIFTS TO STRONG UPPER LOW CURRENTLY OFF THE
CALIFORNIA COAST AND ITS POTENTIAL IMPACTS INTO THE WEEKEND. UPPER
LOW WILL QUICKLY LIFT NORTHEAST INTO THE CENTRAL PLAINS BY
SATURDAY. STRONG TO SEVERE THUNDERSTORMS WILL BE LIKELY SATURDAY
AFTERNOON INTO SATURDAY EVENING AS THE COLD FRONT SWEEPS EAST
THROUGH THE AREA. STRONG LOW LEVEL WIND FIELDS WILL DEVELOP AHEAD
OF FRONT AND WITH MODERATE INSTABILITY EXPECTED...ALL MODES OF
SEVERE WEATHER WILL BE POSSIBLE. THE SEVERE THREAT SHOULD END
SUNDAY MORNING AS CONVECTIVE LINE SWEEPS EAST.
FOR THE REMAINDER OF THE FORECAST...WARM/DRY CONDITIONS ARE
GENERALLY EXPECTED. ANOTHER COLD FRONT IS EXPECTED AROUND MID
WEEK...HOWEVER AS IT APPEARS NOW...LIMITED MOISTURE WILL KEEP
PRECIPITATION CHANCES LOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 75 68 82 66 / 10 80 60 20
FSM 72 65 81 63 / 30 50 30 10
MLC 79 66 83 66 / 20 30 20 10
BVO 76 60 78 63 / 10 80 60 40
FYV 67 60 78 61 / 20 80 60 10
BYV 66 58 74 61 / 20 80 60 10
MKO 74 65 81 64 / 20 60 30 10
MIO 70 61 78 63 / 20 80 60 20
F10 77 66 81 66 / 20 50 30 20
HHW 80 66 84 64 / 20 20 20 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...30
AREA FORECAST DISCUSSION
NWS NORMAN OK
1240 AM CDT THU OCT 11 2012
.AVIATION...
RAPID MOISTURE RETURN HAS LEAD TO WIDESPREAD LOW CLOUDS THIS
MORNING. MVFR/IFR CIGS ARE EXPECTED TO PERSIST THROUGH MOST OF THE
TAF PERIOD AT ALL BUT KGAG AND KWWR. ISOLD DZ/-SHRA WILL BE
POSSIBLE...PRIMARILY AFTER 08Z FROM KSPS AND KLAW...NNEWD TO KOKC
AND KPNC. HOWEVER...LITTLE IMPACT TO VSBYS IS EXPECTED. EXPECT BKN
MVFR CIGS TO LINGER INTO THE AFTERNOON TOMORROW AT MOST TAF SITES.
&&
.PREV DISCUSSION... /ISSUED 851 PM CDT WED OCT 10 2012/
UPDATE...
ONLY MINOR TWEAKS TO TONIGHTS GRIDS. STILL APPEARS THERE IS AN
OUTSIDE CHANCE FOR SOME LATE NIGHT SHOWERS OR PERHAPS A
THUNDERSTORM. OTHERWISE MILD NIGHT AS CLOUD COVER OVERSPREADS THE
AREA AND LOW LEVEL MOISTURE BEGINS TO INCREASE WITH THE RETURN OF
SOUTH WINDS. NO UPDATES AT THIS TIME.
PREV DISCUSSION... /ISSUED 631 PM CDT WED OCT 10 2012/
DISCUSSION...
PLEASE SEE THE 00Z AVIATION DISCUSSION BELOW.
AVIATION...
MOSTLY MVFR DUE TO LOW CIGS WILL PREVAIL THROUGH AT LEAST THE
OVERNIGHT HOURS FOR A MAJORITY OF THE TERMINALS. THE WINDS WILL
BEGIN TO SHIFT FROM THE SOUTH LATE TONIGHT AND EARLY TOMORROW
MORNING...INCREASING TO AROUND 15 TO 20KT BY TOMORROW AFTERNOON.
VFR MAY RETURN AT PNC..WWR..AND GAG AROUND 12-18Z...BUT THE OTHER
TERMINALS MAY NOT EXPERIENCE THESE IMPROVED CONDITIONS UNTIL AFTER
18Z.
PREV DISCUSSION... /ISSUED 335 PM CDT WED OCT 10 2012/
DISCUSSION...
STRATUS CONTINUES TO SPREAD NORTH ACROSS THE AREA AND EXPECT
OVERCAST SKIES AREAWIDE BY MID-LATE EVENING. HRRR HAS SOME SIGNAL
THAT CLEARING OVER CENTRAL TEXAS NOW MAY SPREAD INTO NORTH TEXAS
ZONES LATE TONIGHT... BUT MOST SIGNAL IS FOR STRATUS PERSISTANCE
OR REDEVELOPMENT WITH THIS LOW-LEVEL MOISTURE ADVECTION... SO WILL
JUST KEEP THE OVERCAST SKIES THROUGHOUT. MAY SEE SOME LIGHT
SHOWERS DEVELOP OVERNIGHT AS LOW-LEVEL MOISTURE INCREASES.
STORM CHANCES INCREASE THURSDAY NIGHT AND PERSIST THROUGH AT LEAST
SATURDAY AS EXPECTED WITH /A/ THE ARRIVAL OF A COLD FRONT MOVING
SOUTH THROUGH THE CENTRAL PLAINS IN RESPONSE TO A STORM SYSTEM
SWINGING THROUGH THE GREAT LAKES.. AND /B/ THE STORM SYSTEM
CURRENTLY ON THE SOUTHERN CALIFORNIA COAST MOVING TOWARD THE
PLAINS. NO REAL SIGNIFICANT CHANGE IN THE EXPECTATIONS FROM THE
PREVIOUS FORECAST WITH THIS SYSTEM... SO HAVE ONLY MADE MINOR
CHANGES TO THE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 80 65 83 66 / 20 40 50 30
HOBART OK 80 64 81 62 / 20 40 40 50
WICHITA FALLS TX 84 67 85 68 / 20 20 20 30
GAGE OK 84 58 75 61 / 20 40 50 70
PONCA CITY OK 81 61 76 66 / 20 60 50 50
DURANT OK 82 65 85 66 / 20 20 20 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
17/84/84
AREA FORECAST DISCUSSION
NWS TULSA OK
1150 PM CDT WED OCT 10 2012
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
CEILINGS WILL CONTINUE TO LOWER OVERNIGHT WITH WIDESPREAD MVFR
CONDITIONS DEVELOPING 09-12Z AND CONTINUING THROUGH AT LEAST 18Z
THU. ISOLATED SHOWERS OR THUNDERSTORMS POSSIBLE OVERNIGHT BUT
LIMITED COVERAGE PRECLUDES MENTION IN TAFS AND IMPACTS UNLIKELY TO
CAUSE REDUCTION IN FLIGHT CATEGORY. GRADUAL IMPROVEMENT TO VFR
SHOULD OCCUR BY 21Z...WITH MORE SIGNIFICANT THUNDERSTORM CHANCES
HOLDING OFF UNTIL JUST AFTER END OF FORECAST PERIOD.
&&
.PREV DISCUSSION... /ISSUED 933 PM CDT WED OCT 10 2012/
..UPDATE...
DISCUSSION...
ELEVATED MOISTURE RETURN IS UNDERWAY THIS EVENING EVIDENT WITH
EXPANDING STRATUS DECK WHILE ELEVATED WARM FRONTAL ZONE WORKS
NORTHWARD PER AREA 88D VWP DATA. 00Z KOUN/KSGF SOUNDINGS SAMPLE
BOTH THE MOISTURE LAYER /KOUN/ AND THE EDGE OF THE WEAKER CAPPING
ALOFT /KSGF/. THIS MOIST LAYER HEIGHT ALIGNS WELL WITH KSRX VWP
FRONTAL DEPTH AND SUPPORTS SHORT TERM MODEL SOLUTIONS OF
GENERATING LIGHT PRECIP LATER TONIGHT AS MOISTURE SPREADS
EASTWARD. LATEST LOCAL WRF / HRRR RUNS FAVOR E/SE AREAS OF THE
FORECAST AREA FOR BULK OF LATE NIGHT PRECIP WITH INSTABILITY IN
PLACE TO WARRANT A FEW THUNDERSTORMS. HRRR LIGHTNING FORECASTS
ALSO SUPPORT THIS TREND WITH ANY THUNDERSTORM LIKELY DEVELOPING
MORE TOWARD SUNRISE AND AFTERWARD. HAIL WILL BE POSSIBLE WITH MOST
ANY SUSTAINED UPDRAFT THOUGH THE RISK OF SEVERE CRITERIA HAIL
LOOKS VERY LOW THROUGH THE REMAINDER OF TONIGHT. UPDATED FORECAST
WILL ADJUST WX GRIDS AND SKY COVER TRENDS. FAR NE OK HAS COOLED
QUICKLY PRIOR TO LOW CLOUD ARRIVAL..BUT THIS TREND SHOULD STEADY
SOON. TEMPS ADJUSTMENTS WERE SLIGHTLY DOWN FOR FAR NE OK AND
SLIGHTLY UPWARD ELSEWHERE GIVEN THICK CLOUD BLANKET.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...14
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
815 PM EDT FRI OCT 12 2012
.SYNOPSIS...
COLD HIGH PRESSURE WILL BUILD INTO THE REGION OVERNIGHT...BRINGING
A WIDESPREAD KILLING FROST AND FREEZE. DRY CONDITIONS WILL
CONTINUE THROUGH THE WEEKEND BEFORE ANOTHER COLD FRONT MOVES OUR
WAY MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
CLEAR SKIES COVERED ALL OF PENN THIS EVENING...AND EXTENDED ALL
THE WAY WEST THROUGH INDIANA AND LAKE MICHIGAN.
1031 MB SFC HIGH NEAR LONDON ONTARIO AT 00Z WILL BUILD SE AND
BECOME CENTERED RIGHT OVER CENTRAL PENN AT DAYBREAK SATURDAY.
LIGHT WIND...AND ANOMALOUSLY LOW PWAT AIR OF AROUND 0.30 OF AN
INCH /AND CORRESPONDING SFC DEWPOINTS CURRENTLY IN UPPER TEENS TO
LOWER 20S/ WILL YIELD THE COLDEST TEMPERATURES OF THE FALL SEASON
THUS FAR. WIDESPREAD SUB-FREEZING TEMPS ARE IN STORE EARLY
SATURDAY MORNING...AND IT`S BECOMING QUITE LIKELY THAT WE`LL SEE
NORMALLY COLDER VALLEYS THROUGHOUT NRN PENN DIPPING INTO THE UPPER
TEENS /BASED ON COMPARISON OF CURRENT 00Z TEMPS AND MAV/MOS
GUIDANCE WITH KBFD ALREADY AT A CHILLY 34F/.
SREF MEAN SKIN TEMPS ARE WAY TOO WARM...AND TO A LESSER DEGREE -
THE 21Z HRRR IS ALREADY FALLING BEHIND /WARMER/ THAN 00Z SFC OBS
BY 2-3F IN MANY LOCATIONS.
WILL BE TRIMMING OUR PREVIOUSLY FCST OVERNIGHT MINS /TO BE MORE IN
LINE WITH GENERAL MET/MAV BLEND/ AND UPDATING THE FREEZE WARNING TO
INDICATE THE ANTICIPATED COLDER TEMPS THROUGH THE OVERNIGHT
HOURS.
THESE WIDESPREAD SUB-FREEZING TEMPS AND FROST WILL EFFECTIVELY
BRING TO A CLOSE THE 2012 GROWING SEASON ACROSS OUR CWA.
SEE CLIMATE SECTION FOR A COUPLE OF RECORD LOWS THAT LOOK VERY
VULNERABLE.
&&
.SHORT TERM /SATURDAY NIGHT/...
AFTER A FROSTY START...THE HIGH WILL SLIP OFF THE COAST AND ALLOW A
MILDER SOUTHWEST FLOW TO DEVELOP FOR THE AFTERNOON. AFTERNOON
TEMPERATURES SHOULD REBOUND NICELY INTO THE 50S TO NEAR 60...BUT
STILL SEVERAL DEGREES BELOW NORMAL FOR MID OCTOBER.
SOME CLOUDS AND AN ISOLATED SHOWER MAY CREEP INTO NWRN ZONES BEFORE
THE AFTERNOON IS OVER...BUT CHANCES WILL BE LOW AND MOST LOCATIONS
WILL REMAIN DRY AND HAVE A FINE AUTUMN DAY FOR OUTDOOR ACTIVITIES.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
ABOVE NORMAL HEIGHTS EXTENDING FROM THE SE STATES INTO THE SRN
MID-ATLANTIC WILL QUICKLY BE LOWERED BY UPPER LOW/SHORTWAVE TROUGH
EJECTING EWD THROUGH THE PLAINS SUN-MON. INTO THE MIDDLE OF NEXT
WEEK...A TROUGH IN THE NERN PAC ATOP A LOW-AMPLITUDE RIDGE
BUILDING EWD FM HAWAII INTO SRN CALIF SHOULD ALLOW STRONG JET OVER
THE PAC NW TO CARVE OUT A BROAD TROUGH DOWNSTREAM IN THE CENTRAL
AND ERN U.S. HIGH LATITUDE BLOCKING /NEGATIVE AO-NAO/ MAY ALSO
CONTRIBUTE TO THE TROUGHING EAST OF THE MS RIVER...BUT THE OVERALL
FLOW LOOKS FAIRLY PROGRESSIVE. INCREASING MODEL DISPERSION BY DAY
SIX...COMBINED WITH THE PROGRESSIVE FLOW ALOFT RESULTS IN LOW
CONFIDENCE IN THE FCST DETAILS. THE GLOBAL ENSEMBLE MEANS SHOW A
BROAD ZONAL FLOW PATTERN ACROSS THE CONUS BY THE END OF THE MEDIUM
RANGE PERIOD.
CLOSED LOW MOVING EWD ACRS SRN NV/UT THIS AFTN WILL EJECT EWD ACRS
THE SRN ROCKIES/S-CENTRAL PLAINS STATES FRI-SAT...WITH A DEVELOPING
SFC CYCLONE REACHING THE GREAT LAKES ON SUNDAY. A TRAILING COLD
FRONT WILL EXTEND SWWD THROUGH THE MS VLY...WITH A WARM FRONT
ARCHING EWD ACRS THE LOWER LKS INTO THE NORTHEAST STATES. ALTHOUGH
CONFIDENCE IS A LITTLE SHAKY OR A BIT BELOW AVG WITH THIS
SYSTEM DUE TO MODEL DIFFS...THERE IS A GENERAL CONSENSUS THAT THE
BULK OF OVRRNG/WARM FRONTAL RAINS SHOULD STAY NORTH OF PA ON
SUNDAY...FOLLOWED BY SHOWERS WITH THE COLD FROPA ON MONDAY.
CONFIDENCE CONTINUES TO DROP OFF INTO THE MIDDLE OF NEXT WEEK...AS
IT NOW APPEARS SOME DETERMINISTIC MODELS /AND TO A LESSER EXTENT
THEIR ENSEMBLE MEANS/ WANT TO MERGE A CARIBBEAN SYSTEM WITH THE
MID-LEVEL TROUGH OVER THE NORTHEAST STATES OR SERN CANADA. HPC
PREFERS A NON-NCEP BLEND FOR THE SUNDAY-MONDAY SYSTEM. BEYOND
THAT...EMPLOYED A NEAR EVEN BLEND OF AVAILABLE MEDIUM RANGE
GRIDDED DATA WITH A SLIGHT EDGE TO THE EXPERIMENTAL IN-HOUSE
00Z ECMWF MOS...WHICH HAS SHOWN IMPROVEMENT OVER THE GFS-BASED MOS
PRODUCTS FOR MOST WEATHER ELEMENTS.
WEATHER IMPACTS...SUNDAY LOOKS VERY MILD AND BREEZY IN THE WARM
SECTOR...WITH TEMPS 5-10 DEGREES ABOVE NORMAL. THE BULK OF SUNDAY
SHOULD BE MAINLY DRY ESPECIALLY OVER CENTRAL AND ERN SECTIONS. LOOK
FOR CONDITIONS TO GO DOWNHILL INTO MONDAY AS A COLD FRONT
TRAVERSES THE AREA. NOT MUCH IN STORE AROUND THE MIDDLE OF THE
NEXT...WITH ANOTHER SYSTEM FCST TO AFFECT THE REGION AROUND THE
END OF NEXT WEEK. WITH THE EXCEPTION OF SUNDAY...TEMPERATURES
SHOULD BE NEAR SEASONAL NORMALS THROUGH THE REMAINDER OF THE
PERIOD. BASED ON THE LATEST 12Z MODEL AND ENSEMBLE GUIDANCE...THE
HIGHEST PROBABILITY FOR RAINFALL IS ON MONDAY OCT 15TH.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDS EXPECTED THROUGH THE TAF PERIOD. CLEAR SKIES WILL
CONTINUE OVERNIGHT...AND AT LEAST THROUGH SATURDAY MORNING AS
HIGH PRESSURE BUILDS ACROSS THE REGION.
LIGHT NRLY WINDS AT 00Z WILL DIMINISH TO NEAR CALM AT ALL
AIRFIELDS BY 03Z.
OUTLOOK...
SAT...NO SIG WX.
SUN...MAINLY VFR...SOME SHOWERS POSSIBLE FAR NORTH.
MON...MAINLY VFR...SOME LOWER CONDITIONS POSSIBLE WITH A COLD
FRONT AND SCATTERED SHOWERS.
TUE AND WED...NO SIG WX.
&&
.CLIMATE...
RECORD LOWS ARE IN JEOPARDY FOR OCT 13TH AT OUR OFFICIAL CLIMATE
SITES: MDT AND IPT. A WIDESPREAD FROST/HARD FREEZE IS LIKELY IN
MOST LOCATIONS OVERNIGHT INTO SATURDAY MORNING. THE GROWING SEASON
SHOULD COME TO AN END FOR MUCH...IF NOT ALL OF CENTRAL PA.
THE RECORD LOW FOR OCT 13TH AT HARRISBURG /MDT/ IS 31 DEGREES SET
BACK IN 1988.
THE RECORD LOW FOR OCT 13TH AT WILLIAMSPORT /IPT/ IS 28 DEGREES
SET BACK IN 1931 AND 1906.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING FROM 2 AM TO 9 AM EDT SATURDAY FOR PAZ010>012-
017>019-025>028-034>037-041-042-045-046-049>053-056>059-
063>066.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LAMBERT/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...STEINBUGL
AVIATION...LAMBERT/GARTNER
CLIMATE...LA CORTE
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1220 PM CDT THU OCT 11 2012
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...ISOLATED SHOWERS ARE EXPECTED...MAINLY ALONG AND WEST
OF HIGHWAY 77 THROUGH THE REMAINDER OF THE AFTERNOON. THUNDERSTORM
DEVELOPMENT IS POSSIBLE...MAINLY FROM MFE NORTHWARD TO ABOUT HBV
OR BKS THROUGH MID AFTERNOON. BRIEF MVFR VISBY AND GUSTY WINDS CAN
BE EXPECTED AT AIRFIELDS THAT HAPPEN TO CATCH A THUNDERSTORM THIS
AFTERNOON. SOUTHEAST WINDS...GUSTING AT 20 TO 25 KNOTS ARE
EXPECTED THROUGH LATE AFTERNOON AT ALL SITES.
TONIGHT WINDS SHOULD SUBSIDE TO 6 TO 8 KNOTS...BUT AN MVFR CIG AT
AROUND 2000 TO 2500 FT MAY SET UP BY AROUND 09Z THROUGH MOST OF
THE REGION...LASTING THROUGH SUNRISE. LOWEST CIGS ARE EXPECTED AT BKS
AND HBV. THAT CEILING SHOULD GRADUALLY LIFT THROUGH EARLY MORNING
AND ANOTHER ROUND OF GUSTY SOUTH TO SOUTHEAST WINDS IS ANTICIPATED
STARTING AT AROUND 15Z. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 1006 AM CDT THU OCT 11 2012/
DISCUSSION...UPDATED NEAR TERM POP GRIDS BASED ON LATEST
OBSERVATIONAL TRENDS. SHOWERS SOUTH OF HIDALGO AND CAMERON COUNTY
ARE LIFTING FROM AROUND 950MB...AND WILL LIKELY PERSIST FOR
ANOTHER HOUR OR TWO BEFORE DIMINISHING. CU STREAKS ALONG THE
IMMEDIATE COASTAL REGION ON VISIBLE SATELLITE POINT TO SEABREEZE
CONVERGENCE FORMING UP ON SCHEDULE THIS MORNING. MODIFIED OBSERVED
AND LAPS SOUNDINGS SHOW WE WILL ONLY NEED ABOUT 2000FT OF
MECHANICAL LIFTING TO GET CONVECTION TODAY WITH SLIGHTLY COOLER
TEMPERATURES AT 850 TO 925MB THAN YESTERDAY WITH JUST SLIGHTLY
BETTER MOISTURE. ANY SURFACE BASED PARCELS THAT MAKE IT TO
THUNDERSTORM STATUS WILL HAVE ABOUT 3000 J/KG OF CAPE WITH A THETA
E DIFFERENTIAL OF AROUND 35 K...SO GUSTY WINDS WILL BE POSSIBLE.
WITH A COLUMN PWAT AROUND 1.80 STORMS WILL ALSO BE EFFICIENT
RAINFALL PRODUCERS. WITH THE STRONGER SOUTHEAST WINDS TODAY STILL
EXPECT THAT WILL BE ISOLATED AT BEST FOR NOW. 14Z RAP...WHICH
SEEMS TO HAVE A GOOD HANDLE...09Z SREF AND 12Z HRRR USED
PARTIALLY TO ASSIST WITH LOCATION OF BEST RAINFALL CHANCES AND
TIMING. NEAR TERM DEWPOINTS AND SKY ALSO TWEAKED...BUT PACAKGE IS
IN GOOD SHAPE OVERALL. /68-JGG/
PREV DISCUSSION... /ISSUED 623 AM CDT THU OCT 11 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...STREAMER SHOWERS ARE ATTEMPTING TO MOVE INLAND NEAR THE
COAST THIS MORNING. EXPECT REMNANTS OF THESE SHOWERS TO PASS NEAR
IMMEDIATELY COASTAL AIRPORTS DURING THE NEXT COUPLE HOURS...WITH
TEMPO CIG REDUCTIONS TO AROUND 2000 FEET. SCT TO BKN CLOUDS AT
AROUND 3500 FT ARE EXPECTED BY MID TO LATE MORNING WITH SCATTERED
SHOWERS AND POSSIBLY A THUNDERSTORM DEVELOPING ALONG THE SEABREEZE
AND MOVING WEST. WINDS WILL JUMP TO 15G25KTS LATER THIS AFTERNOON
BEFORE REDUCING BACK TO AROUND 5KTS OVERNIGHT.
PREV DISCUSSION... /ISSUED 426 AM CDT THU OCT 11 2012/
SHORT TERM /TODAY THROUGH FRIDAY/...MIDLEVEL RIDGE SLOWLY
BUILDING ALOFT OVERHEAD DURING THE NEXT 36 HOURS. THIS WILL BE
COUNTERACTED BY SOUTHEAST FLOW AT THE SFC CONTINUING TO INCREASE
LLVL MOISTURE. PW VALUES ABOVE 1.8 INCHES AND TEMPERATURES IN THE
90S AREAWIDE WILL ALLOW THE SEABREEZE TO FORM AND DRIFT NEWD
ACROSS THE REGION TODAY. WINDS OF 15 TO 20KTS WILL MAKE THE
SEABREEZE A MORE DIFFUSE BOUNDARY...BUT SHOWERS WILL BE ABLE TO
POP UP THIS AFTERNOON...ALSO AIDED BY INSTABILITY FROM STREAMER
SHOWERS CURRENTLY ATTEMPTING TO MOVE ASHORE FROM THE SOUTHEAST.
TEMPERATURES WILL BE NEAR YESTERDAY/S HIGHS...IMPEDED SLIGHTLY BY
INCREASED MOISTURE. OF NOTE WERE YESTERDAY/S TEMPERATURES IN MFE
/96/ AND EBG /98/ WERE HIGHER THAN DEATH VALLEY CALIFORNIA /95/.
ANOTHER HOT AND HUMID DAY TOMORROW WITH ANOTHER ROUND OF SEABREEZE
SHOWERS.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY...EXTENDED DOES NOT
VARY MUCH FROM YESTERDAY WITH EXCEPTION TO THE ADDITION OF SLIGHT
CHANCE OF RAIN ACROSS THE NORTHERN TIER COUNTIES MONDAY AS A
WEAKENING COLD FRONT APPROACHES. OTHERWISE...HIGH PRESSURE TO
DOMINATE THROUGH THE COMING WEEKEND WITH HOT AND DRY WEATHER THEN
THE RIDGE BREAKS DOWN AS A BROAD LOW PRESSURE TROUGH DEVELOPS
ACROSS THE EASTERN TWO THIRDS OF THE COUNTRY.
FORECAST TRENDS WITH THE GFS WITH ENSEMBLE MEMBERS SHOWING A
NARROW VARIANCE THROUGH THE NEXT 7 DAYS. THE FIRST THREE DAYS GFS
AND ECMWF SHOW GOOD CONSISTENCY THROUGH THE WEEKEND BEFORE SOME
MID LEVEL PATTERN DIFFERENCES START DEVELOPING IN BY THE END OF
THE FORECAST PACKAGE.
MAIN FEATURES WE ARE KEEPING AN EYE ON ARE AN UPPER LOW OFF THE
CALIFORNIA COAST AND A STRONG MID LEVEL RIDGE PARKED OVER THE
WESTERN GULF. SURFACE PRESSURE TO LOWER ACROSS THE SOUTHERN PLAINS
FRIDAY NIGHT THROUGH SATURDAY WITH A LOW LEVEL JET GAINING
STRENGTH. THIS WILL GENERATE WINDY CONDITIONS SATURDAY WITH GUSTS
UPWARDS OF 35 MPH. DO NOT THINK GRADIENT WILL BE STRONG ENOUGH FOR
A WIND ADVISORY WITH SURFACE HIGH OVER THE GULF NOT AS STRONG AS
WOULD LIKE TO SEE. THE SOUTHERLY FLOW PUMPS IN SOME MOISTURE
ACROSS THE REGION WITH TEMPERATURE PICKING RISING WELL ABOVE
NORMAL. THE MID LEVEL LOW LIFTS QUICKLY NORTHEAST DRAGGING A
PACIFIC FRONT ACROSS THE STATE. GFS AND ECMWF PLACE WITH FRONT
NEAR THE NORTHERN COUNTIES SUNDAY WHICH MIGHT BE CLOSE ENOUGH TO
WARRANT A FEW SHOWERS OR THUNDERSTORMS. GFS IS MUCH HIGHER ON THE
POPS THEN ECMWF SO A LOW BIAS ON RAIN CHANCES WERE ADDED ACROSS
THE NORTH. DOWN SOUTH MUCH OF THE SAME FOR NOW.
LITTLE CHANGE MADE TO THE LATTER HALF OF THE FORECAST WITH A
PERSISTENT WEAK MIDLEVEL NORTHWEST FLOW. AS MENTIONED ABOVE
FORECAST TRENDS TOWARDS THE GFS WITH ABOVE NORMAL TEMPERATURES AND
KEEPING ANY FRONTS WELL NORTH OF THE REGION UNTIL MAYBE THURSDAY OR
FRIDAY. EUROPEAN MODELS IS MORE AGGRESSIVE WITH THE TROUGH OVER THE
CENTRAL PLAINS AND IS MORE AGGRESSIVE WITH A FRONT THROUGH THE
AREA WEDNESDAY. WILL DETER FROM THIS SOLUTION FROM NOW UNTIL
BETTER MODEL CONSISTENCY IS SEEN.
MARINE...TODAY THROUGH FRIDAY...WINDS ACROSS THE GULF WATERS WILL
INCREASE TO 15 TO 20 KNOTS TODAY...WITH SEAS FLUCTUATING BETWEEN 3
AND 5 FEET THIS AFTERNOON. THESE CONDITIONS ARE FORECAST TO CONTINUE
THROUGH THURSDAY NIGHT INTO FRIDAY. ADVISORIES ARE NOT CURRENTLY
FORECAST...BUT SMALL CRAFT SHOULD EXERCISE CAUTION.
FRIDAY NIGHT THROUGH MONDAY...SMALL CRAFT ADVISORY ARE BECOMING
MORE PROBABLE FRIDAY NIGHT THROUGH SATURDAY AS THE PRESSURE
GRADIENT STRENGTHENS AS SURFACE PRESSURES LOWER SIGNIFICANTLY OVER
NORTHWEST TEXAS IN RESPONSE TO AN UPPER LOW MOVING THROUGH THE
SOUTHERN ROCKIES. STRONG WIND AND BUILD WIND WAVES ARE IN ORDER
THROUGH SATURDAY NIGHT. WINDS AND SEAS BEGIN TO RELAX SUNDAY AND
BECOME LOWER MONDAY AS THE LOW LIFTS OUT AND A WEAK FRONT STALLS
JUST NORTH OF THE REGION.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/66
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1006 AM CDT THU OCT 11 2012
.DISCUSSION...UPDATED NEAR TERM POP GRIDS BASED ON LATEST
OBSERVATIONAL TRENDS. SHOWERS SOUTH OF HIDALGO AND CAMERON COUNTY
ARE LIFTING FROM AROUND 950MB...AND WILL LIKELY PERSIST FOR
ANOTHER HOUR OR TWO BEFORE DIMINISHING. CU STREAKS ALONG THE
IMMEDIATE COASTAL REGION ON VISIBLE SATELLITE POINT TO SEABREEZE
CONVERGENCE FORMING UP ON SCHEDULE THIS MORNING. MODIFIED OBSERVED
AND LAPS SOUNDINGS SHOW WE WILL ONLY NEED ABOUT 2000FT OF
MECHANICAL LIFTING TO GET CONVECTION TODAY WITH SLIGHTLY COOLER
TEMPERATURES AT 850 TO 925MB THAN YESTERDAY WITH JUST SLIGHTLY
BETTER MOISTURE. ANY SURFACE BASED PARCELS THAT MAKE IT TO
THUNDERSTORM STATUS WILL HAVE ABOUT 3000 J/KG OF CAPE WITH A THETA
E DIFFERENTIAL OF AROUND 35 K...SO GUSTY WINDS WILL BE POSSIBLE.
WITH A COLUMN PWAT AROUND 1.80 STORMS WILL ALSO BE EFFICIENT
RAINFALL PRODUCERS. WITH THE STRONGER SOUTHEAST WINDS TODAY STILL
EXPECT THAT WILL BE ISOLATED AT BEST FOR NOW. 14Z RAP...WHICH
SEEMS TO HAVE A GOOD HANDLE...09Z SREF AND 12Z HRRR USED
PARTIALLY TO ASSIST WITH LOCATION OF BEST RAINFALL CHANCES AND
TIMING. NEAR TERM DEWPOINTS AND SKY ALSO TWEAKED...BUT PACAKGE IS
IN GOOD SHAPE OVERALL. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 623 AM CDT THU OCT 11 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...STREAMER SHOWERS ARE ATTEMPTING TO MOVE INLAND NEAR THE
COAST THIS MORNING. EXPECT REMNANTS OF THESE SHOWERS TO PASS NEAR
IMMEDIATELY COASTAL AIRPORTS DURING THE NEXT COUPLE HOURS...WITH
TEMPO CIG REDUCTIONS TO AROUND 2000 FEET. SCT TO BKN CLOUDS AT
AROUND 3500 FT ARE EXPECTED BY MID TO LATE MORNING WITH SCATTERED
SHOWERS AND POSSIBLY A THUNDERSTORM DEVELOPING ALONG THE SEABREEZE
AND MOVING WEST. WINDS WILL JUMP TO 15G25KTS LATER THIS AFTERNOON
BEFORE REDUCING BACK TO AROUND 5KTS OVERNIGHT.
PREV DISCUSSION... /ISSUED 426 AM CDT THU OCT 11 2012/
SHORT TERM /TODAY THROUGH FRIDAY/...MIDLEVEL RIDGE SLOWLY
BUILDING ALOFT OVERHEAD DURING THE NEXT 36 HOURS. THIS WILL BE
COUNTERACTED BY SOUTHEAST FLOW AT THE SFC CONTINUING TO INCREASE
LLVL MOISTURE. PW VALUES ABOVE 1.8 INCHES AND TEMPERATURES IN THE
90S AREAWIDE WILL ALLOW THE SEABREEZE TO FORM AND DRIFT NEWD
ACROSS THE REGION TODAY. WINDS OF 15 TO 20KTS WILL MAKE THE
SEABREEZE A MORE DIFFUSE BOUNDARY...BUT SHOWERS WILL BE ABLE TO
POP UP THIS AFTERNOON...ALSO AIDED BY INSTABILITY FROM STREAMER
SHOWERS CURRENTLY ATTEMPTING TO MOVE ASHORE FROM THE SOUTHEAST.
TEMPERATURES WILL BE NEAR YESTERDAY/S HIGHS...IMPEDED SLIGHTLY BY
INCREASED MOISTURE. OF NOTE WERE YESTERDAY/S TEMPERATURES IN MFE
/96/ AND EBG /98/ WERE HIGHER THAN DEATH VALLEY CALIFORNIA /95/.
ANOTHER HOT AND HUMID DAY TOMORROW WITH ANOTHER ROUND OF SEABREEZE
SHOWERS.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY...EXTENDED DOES NOT
VARY MUCH FROM YESTERDAY WITH EXCEPTION TO THE ADDITION OF SLIGHT
CHANCE OF RAIN ACROSS THE NORTHERN TIER COUNTIES MONDAY AS A
WEAKENING COLD FRONT APPROACHES. OTHERWISE...HIGH PRESSURE TO
DOMINATE THROUGH THE COMING WEEKEND WITH HOT AND DRY WEATHER THEN
THE RIDGE BREAKS DOWN AS A BROAD LOW PRESSURE TROUGH DEVELOPS
ACROSS THE EASTERN TWO THIRDS OF THE COUNTRY.
FORECAST TRENDS WITH THE GFS WITH ENSEMBLE MEMBERS SHOWING A
NARROW VARIANCE THROUGH THE NEXT 7 DAYS. THE FIRST THREE DAYS GFS
AND ECMWF SHOW GOOD CONSISTENCY THROUGH THE WEEKEND BEFORE SOME
MID LEVEL PATTERN DIFFERENCES START DEVELOPING IN BY THE END OF
THE FORECAST PACKAGE.
MAIN FEATURES WE ARE KEEPING AN EYE ON ARE AN UPPER LOW OFF THE
CALIFORNIA COAST AND A STRONG MID LEVEL RIDGE PARKED OVER THE
WESTERN GULF. SURFACE PRESSURE TO LOWER ACROSS THE SOUTHERN PLAINS
FRIDAY NIGHT THROUGH SATURDAY WITH A LOW LEVEL JET GAINING
STRENGTH. THIS WILL GENERATE WINDY CONDITIONS SATURDAY WITH GUSTS
UPWARDS OF 35 MPH. DO NOT THINK GRADIENT WILL BE STRONG ENOUGH FOR
A WIND ADVISORY WITH SURFACE HIGH OVER THE GULF NOT AS STRONG AS
WOULD LIKE TO SEE. THE SOUTHERLY FLOW PUMPS IN SOME MOISTURE
ACROSS THE REGION WITH TEMPERATURE PICKING RISING WELL ABOVE
NORMAL. THE MID LEVEL LOW LIFTS QUICKLY NORTHEAST DRAGGING A
PACIFIC FRONT ACROSS THE STATE. GFS AND ECMWF PLACE WITH FRONT
NEAR THE NORTHERN COUNTIES SUNDAY WHICH MIGHT BE CLOSE ENOUGH TO
WARRANT A FEW SHOWERS OR THUNDERSTORMS. GFS IS MUCH HIGHER ON THE
POPS THEN ECMWF SO A LOW BIAS ON RAIN CHANCES WERE ADDED ACROSS
THE NORTH. DOWN SOUTH MUCH OF THE SAME FOR NOW.
LITTLE CHANGE MADE TO THE LATTER HALF OF THE FORECAST WITH A
PERSISTENT WEAK MIDLEVEL NORTHWEST FLOW. AS MENTIONED ABOVE
FORECAST TRENDS TOWARDS THE GFS WITH ABOVE NORMAL TEMPERATURES AND
KEEPING ANY FRONTS WELL NORTH OF THE REGION UNTIL MAYBE THURSDAY OR
FRIDAY. EUROPEAN MODELS IS MORE AGGRESSIVE WITH THE TROUGH OVER THE
CENTRAL PLAINS AND IS MORE AGGRESSIVE WITH A FRONT THROUGH THE
AREA WEDNESDAY. WILL DETER FROM THIS SOLUTION FROM NOW UNTIL
BETTER MODEL CONSISTENCY IS SEEN.
MARINE...TODAY THROUGH FRIDAY...WINDS ACROSS THE GULF WATERS WILL
INCREASE TO 15 TO 20 KNOTS TODAY...WITH SEAS FLUCTUATING BETWEEN 3
AND 5 FEET THIS AFTERNOON. THESE CONDITIONS ARE FORECAST TO CONTINUE
THROUGH THURSDAY NIGHT INTO FRIDAY. ADVISORIES ARE NOT CURRENTLY
FORECAST...BUT SMALL CRAFT SHOULD EXERCISE CAUTION.
FRIDAY NIGHT THROUGH MONDAY...SMALL CRAFT ADVISORY ARE BECOMING
MORE PROBABLE FRIDAY NIGHT THROUGH SATURDAY AS THE PRESSURE
GRADIENT STRENGTHENS AS SURFACE PRESSURES LOWER SIGNIFICANTLY OVER
NORTHWEST TEXAS IN RESPONSE TO AN UPPER LOW MOVING THROUGH THE
SOUTHERN ROCKIES. STRONG WIND AND BUILD WIND WAVES ARE IN ORDER
THROUGH SATURDAY NIGHT. WINDS AND SEAS BEGIN TO RELAX SUNDAY AND
BECOME LOWER MONDAY AS THE LOW LIFTS OUT AND A WEAK FRONT STALLS
JUST NORTH OF THE REGION.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/66
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1153 PM CDT WED OCT 10 2012
.DISCUSSION...
SEE THE 06Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
MVFR LIKELY BETWEEN 08Z AND 15Z. OTHERWISE...THE 700 MB TROUGH
THAT WAS OVERHEAD NEAR THE COAST SHOULD SLOWLY MOVE NORTHWARD
TONIGHT AND THURSDAY. THE GFS AND NAM BOTH INDICATE RAIN CHANCES
DURING THE AFTERNOON AFTER 21Z. THE THINKING HERE IS THAT BEST
CHANCES WILL BE OVER THE WESTERN HALF...AND WILL GO WITH A VCTS AT
BOTH KCLL AND KUTS AFTER 21Z.
40
&&
.PREV DISCUSSION... /ISSUED 925 PM CDT WED OCT 10 2012/
UPDATE...
SEE EVENING UPDATE.
DISCUSSION...
RELATIVELY DEEP MOISTURE COUPLED WITH A WEAK 850 TROUGH PRODUCED
SCATTERED SHRA/TSRA THIS AFTN AND EVENING. AM EXPECTING SHRA/TSRA
TO END IN THE NEXT 30 MINUTES OR SO. A FEW OF THE STORMS PRODUCED
SOME HEFTY (3 TO 4 INCHES) RAINFALL TOTALS OVER THE SW ZONES THIS
EVENING. GLS IS ALREADY BELOW FCST VALUES SO WILL TWEAK MIN TEMP
GRIDS A BIT BUT OVERALL FCST FOR TONIGHT IS ON TRACK. T/TD SPREAD
IS NARROWING SO FEEL PATCHY FOG WILL AGAIN BE POSSIBLE. 43
PREV DISCUSSION... /ISSUED 650 PM CDT WED OCT 10 2012/
DISCUSSION...
SEE THE 00Z AVIATION DISCUSSION BELOW.
AVIATION...
A STATIONARY FRONT STRETCHED ACROSS THE NORTHERN PART OF SE TX
EARLY THIS EVENING...WHILE THE 22Z RUC MODEL SHOWED THAT A
SHORTWAVE TROUGH WAS MOVING OVER THE AREA. ISOLATED SHOWERS AND
THUNDERSTORMS THAT DEVELOPED EARLIER...MOST OUTSIDE OF THE
TERMINAL FORECAST SITES AND VICINITY AREAS...SHOULD DIMINISH BY
03Z. HOWEVER..WILL DO FREQUENT CHECKS FOR ANY NEEDED UPDATES.
OTHERWISE...THERE IS GOOD CONFIDENCE IN THE VFR CONDITIONS
BECOMING MVFR BETWEEN 06Z AND 11Z. DIMINISHING WINDS IN THE
BOUNDARY LAYER AS WELL AS A DEVELOPING LOW-LEVEL INVERSION SHOULD
AID IN DEVELOPMENT OF A CLOUD DECK...WHILE FOG IS POSSIBLE
ESPECIALLY AT KLBX. EXPECT THESE CONDITIONS TO IMPROVE BACK TO
VFR BY 15Z.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 70 89 69 89 69 / 10 10 10 0 10
HOUSTON (IAH) 71 89 70 88 71 / 10 10 10 0 10
GALVESTON (GLS) 76 84 75 84 77 / 10 10 10 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT THU OCT 11 2012
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
345 PM CDT THU OCT 11 2012
AT 3 PM...RADAR CONTINUES TO SHOW A BAND OF RAIN SHOWERS ACROSS
SOUTH CENTRAL AND SOUTHEAST MINNESOTA...NORTHERN IOWA...AND
SOUTHERN WISCONSIN. THERE WAS EVEN A REPORT OF A MIX OF RAIN AND
SLEET 7 MILES WEST OF CRESCO IN HOWARD COUNTY. THE KARX
CORRELATION COEFFICIENTS SHOW VALUES AS LOW 0.8 COLLOCATED WITH
THE HIGHEST REFLECTIVITIES...SO WOULD NOT BE SURPRISED THAT THERE
WILL BE OTHER REPORTS THIS AFTERNOON. THIS PRECIPITATION IS
ASSOCIATED WITH MODERATE TO STRONG 900-700 MB FRONTOGENESIS. THE
LATEST RAP CONTINUES TO SHOW THAT THIS FORCING WILL CONTINUE
TO MOVE SOUTH THIS AFTERNOON...AND BY 11.00Z IT SHOULD BE LOCATED
JUST SOUTH OF THE FORECAST AREA.
LIKE THE PAST SEVERAL DAYS...THE 11.12Z MODELS CONTINUE TO SHOW
THAT A CANADIAN HIGH PRESSURE SYSTEM WILL BUILD SOUTH INTO THE
UPPER MISSISSIPPI RIVER VALLEY TONIGHT...AND THEN MOVE QUICKLY
EAST THROUGH THE OHIO RIVER VALLEY AND INTO THE MID ATLANTIC ON
FRIDAY. WITH LIGHT WINDS...MAINLY CLEAR SKIES...AND LIGHT WINDS
OVERNIGHT...TEMPERATURES WILL FALL INTO THE 20S IN MOST LOCATIONS.
THERE MAY BE EVEN A FEW TEENS IN CENTRAL AND NORTH CENTRAL
WISCONSIN.
ON FRIDAY NIGHT...A SHORT WAVE TROUGH WILL EJECT OUT AHEAD OF A
CLOSED LOW PRESSURE SYSTEM OVER COLORADO. MODERATE TO STRONG
ISENTROPIC LIFT WILL DEVELOP AHEAD OF THIS WAVE. IN
ADDITION...THERE WILL BE STRONG 925 AND 850 MB MOISTURE TRANSPORT
INTO THE REGION. THE NAM QUICKLY GENERATES PRECIPITATION ON FRIDAY
EVENING. MEANWHILE THE OTHER MODELS SUGGEST THAT THE PRECIPITATION
WILL NOT DEVELOP UNTIL AFTER MIDNIGHT FRIDAY NIGHT. LOOKING AT THE
BUFKIT MODEL SOUNDINGS THERE IS VERY LITTLE DIFFERENCE BETWEEN THE
GFS AND NAM. BOTH MODELS SHOW THAT DURING THE EVENING THE AIR MASS
WILL MOISTEN RAPIDLY BETWEEN 800 AND 600 MB AND THERE IS SOME
MODERATE OMEGA IN THIS SAME LAYER. DESPITE THE NAM/WRF APPEARING
AS AN OUTLIER DECIDED THAT IT HAD A MUCH BETTER HANDLE OF THE
DEVELOPMENT OF INITIAL SHOWERS THAN THE OTHER MODELS. AFTER
MIDNIGHT...THE 0-3 KM MOST UNSTABLE CAPES CLIMB UP TO 1000 J/KG
MAINLY SOUTH OF THE INTERSTATE 94 CORRIDOR. AS A RESULT...WENT
WITH THE BEST CHANCES FOR THUNDERSTORMS IN THIS AREA. WITH 1-7 KM
SHEAR LESS THAN 25 KNOTS...NOT ANTICIPATING ANY OF THESE
THUNDERSTORMS TO BECOME SEVERE.
ON SATURDAY MORNING...THERE ARE SOME MODELS SUGGEST THAT THE BEST
MOISTURE TRANSPORT WILL MOVE EAST OF THE AREA BY LATE MORNING. AS
A RESULT STILL THINKING THAT THERE WILL BE A POSSIBILITY OF A
BREAK IN THE SHOWERS AND THUNDERSTORMS LATE SATURDAY MORNING AND
EARLY AFTERNOON. THE MAIN QUESTION FOR THE AFTERNOON WILL THERE BE
SOME CLEARING IN THE WARM SECTOR OF THIS SYSTEM TO HELP INCREASE
THE MEAN LAYER CAPES ALONG AND SOUTH OF THE INTERSTATE 90
CORRIDOR. BOTH THE GFS AND NAM CONTINUE TO HINT THAT THIS WILL
MORE LIKELY OCCUR ACROSS EASTERN IOWA...ILLINOIS...AND THE
SOUTHERN QUARTER OF WISCONSIN. HOWEVER THE 10.09Z SUGGEST THAT THE
MLCAPE WILL BE GREATER THAN 500 J/KG...THE 0-1 KM HELICITY WILL BE
GREATER THAN 100...AND BOTH THE 0-3 KM AND 0-6 KM SHEAR WILL BE
FAVORABLE FOR THE POSSIBILITY OF SEVERE WEATHER ALONG THE COLD
FRONT LATE SATURDAY AFTERNOON AND EVENING ALONG AND SOUTH OF THE
INTERSTATE 90 CORRIDOR.
.LONG TERM...SUNDAY THROUGH THURSDAY
345 PM CDT THU OCT 11 2012
ON SUNDAY MORNING...THE MODELS CONTINUE TO SHOW THAT THE
DEFORMATION BAND ON THE BACK SIDE OF THE LOW PRESSURE SYSTEM WILL
STILL LINGER ACROSS MUCH OF THE AREA. AS A RESULT...RAISED THE
PRECIPITATION CHANCES A BIT MORE.
BEYOND THIS TIME PERIOD...THE MODELS CONTINUE TO STRUGGLE ON THE
TIMING OF SYSTEMS AND THE UPPER FLOW. WITH THIS SAID...THERE
CONTINUES TO BE A SIGNAL FOR A STRONG LOW PRESSURE SYSTEM TO
MOVE THROUGH THE REGION ON WEDNESDAY. THIS SYSTEM IS EXPECTED TO
CARVE OUT A BROAD TROUGH ACROSS THE EASTERN CONUS WHICH WILL
RETURN COLDER AIR TO THE REGION.
&&
.AVIATION...
600 PM CDT THU OCT 11 2012
BAND OF -RA ASSOCIATED WITH SOME UPPER LEVEL FRONTOGENETIC FORCING
NORTH OF A WEST-EAST RUNNING SFC COLD FRONT THAT WAS SINKING
SOUTHEAST ACROSS IA/IL. SOME 88-D RADAR RETURNS NEAR KRST/KLSE...BUT
NO GROUND TRUTH VIA OBS. FORCING SHOULD SHIFT SOUTH OF THE TAF SITES
BY 00Z...SO WON/T INCLUDING ANY -RA MENTION.
HIGH PRESSURE BUILDS IN FROM THE NORTHERN PLAINS OVERNIGHT...WITH
THE HIGH OVERHEAD BY 12Z FRI. CLEAR SKIES WITH A LIGHT WIND WILL
RESULT. IT WOULD BE A GREAT SETUP FOR RIVER VALLEY FOG...EXCEPT THE
T/TD SPREAD IS LARGE AND WILL LIKELY REMAIN THAT WAY OVERNIGHT. IN
ADDITION...PROBABLY ADVECTING IN SOME DRIER AIR FROM THE NORTHWEST.
SO...DON/T EXPECT A FG IMPACT AT KLSE FRI MORNING.
THE HIGH WILL EXIT QUICKLY EAST ON FRI...WITH THE WINDS GRADUALLY
SHIFTING TO THE SOUTH AND INCREASING LATER IN THE DAY. CLOUDS WILL
BE ON THE INCREASE FRIDAY NIGHT AS LOW LEVEL THERMODYNAMICS AND
INCREASING SATURATION PUSH IN FROM THE SOUTH/SOUTHWEST...AHEAD OF A
LOW PRESSURE SYSTEM/COLD FRONT APPROACHING FROM THE WEST. AREAS OF
-SHRA WILL LIKELY DEVELOP FROM THE FORCING OVERNIGHT FRI...WITH SAT
LOOKING LIKE A WET DAY. ENOUGH FORCING AND INSTABILITY THAT A FEW
THUNDERSTORMS WILL BE POSSIBLE. EXPECT CIGS TO DROP INTO THE MVFR
RANGE AROUND 12Z SAT OR SHORTLY AFTER...WITH SOME VSBY RESTRICTIONS
IN THE RAIN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
345 PM CDT THU OCT 11 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
346 PM CDT THU OCT 11 2012
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
345 PM CDT THU OCT 11 2012
AT 3 PM...RADAR CONTINUES TO SHOW A BAND OF RAIN SHOWERS ACROSS
SOUTH CENTRAL AND SOUTHEAST MINNESOTA...NORTHERN IOWA...AND
SOUTHERN WISCONSIN. THERE WAS EVEN A REPORT OF A MIX OF RAIN AND
SLEET 7 MILES WEST OF CRESCO IN HOWARD COUNTY. THE KARX
CORRELATION COEFFICIENTS SHOW VALUES AS LOW 0.8 COLLOCATED WITH
THE HIGHEST REFLECTIVITIES...SO WOULD NOT BE SURPRISED THAT THERE
WILL BE OTHER REPORTS THIS AFTERNOON. THIS PRECIPITATION IS
ASSOCIATED WITH MODERATE TO STRONG 900-700 MB FRONTOGENESIS. THE
LATEST RAP CONTINUES TO SHOW THAT THIS FORCING WILL CONTINUE
TO MOVE SOUTH THIS AFTERNOON...AND BY 11.00Z IT SHOULD BE LOCATED
JUST SOUTH OF THE FORECAST AREA.
LIKE THE PAST SEVERAL DAYS...THE 11.12Z MODELS CONTINUE TO SHOW
THAT A CANADIAN HIGH PRESSURE SYSTEM WILL BUILD SOUTH INTO THE
UPPER MISSISSIPPI RIVER VALLEY TONIGHT...AND THEN MOVE QUICKLY
EAST THROUGH THE OHIO RIVER VALLEY AND INTO THE MID ATLANTIC ON
FRIDAY. WITH LIGHT WINDS...MAINLY CLEAR SKIES...AND LIGHT WINDS
OVERNIGHT...TEMPERATURES WILL FALL INTO THE 20S IN MOST LOCATIONS.
THERE MAY BE EVEN A FEW TEENS IN CENTRAL AND NORTH CENTRAL
WISCONSIN.
ON FRIDAY NIGHT...A SHORT WAVE TROUGH WILL EJECT OUT AHEAD OF A
CLOSED LOW PRESSURE SYSTEM OVER COLORADO. MODERATE TO STRONG
ISENTROPIC LIFT WILL DEVELOP AHEAD OF THIS WAVE. IN
ADDITION...THERE WILL BE STRONG 925 AND 850 MB MOISTURE TRANSPORT
INTO THE REGION. THE NAM QUICKLY GENERATES PRECIPITATION ON FRIDAY
EVENING. MEANWHILE THE OTHER MODELS SUGGEST THAT THE PRECIPITATION
WILL NOT DEVELOP UNTIL AFTER MIDNIGHT FRIDAY NIGHT. LOOKING AT THE
BUFKIT MODEL SOUNDINGS THERE IS VERY LITTLE DIFFERENCE BETWEEN THE
GFS AND NAM. BOTH MODELS SHOW THAT DURING THE EVENING THE AIR MASS
WILL MOISTEN RAPIDLY BETWEEN 800 AND 600 MB AND THERE IS SOME
MODERATE OMEGA IN THIS SAME LAYER. DESPITE THE NAM/WRF APPEARING
AS AN OUTLIER DECIDED THAT IT HAD A MUCH BETTER HANDLE OF THE
DEVELOPMENT OF INITIAL SHOWERS THAN THE OTHER MODELS. AFTER
MIDNIGHT...THE 0-3 KM MOST UNSTABLE CAPES CLIMB UP TO 1000 J/KG
MAINLY SOUTH OF THE INTERSTATE 94 CORRIDOR. AS A RESULT...WENT
WITH THE BEST CHANCES FOR THUNDERSTORMS IN THIS AREA. WITH 1-7 KM
SHEAR LESS THAN 25 KNOTS...NOT ANTICIPATING ANY OF THESE
THUNDERSTORMS TO BECOME SEVERE.
ON SATURDAY MORNING...THERE ARE SOME MODELS SUGGEST THAT THE BEST
MOISTURE TRANSPORT WILL MOVE EAST OF THE AREA BY LATE MORNING. AS
A RESULT STILL THINKING THAT THERE WILL BE A POSSIBILITY OF A
BREAK IN THE SHOWERS AND THUNDERSTORMS LATE SATURDAY MORNING AND
EARLY AFTERNOON. THE MAIN QUESTION FOR THE AFTERNOON WILL THERE BE
SOME CLEARING IN THE WARM SECTOR OF THIS SYSTEM TO HELP INCREASE
THE MEAN LAYER CAPES ALONG AND SOUTH OF THE INTERSTATE 90
CORRIDOR. BOTH THE GFS AND NAM CONTINUE TO HINT THAT THIS WILL
MORE LIKELY OCCUR ACROSS EASTERN IOWA...ILLINOIS...AND THE
SOUTHERN QUARTER OF WISCONSIN. HOWEVER THE 10.09Z SUGGEST THAT THE
MLCAPE WILL BE GREATER THAN 500 J/KG...THE 0-1 KM HELICITY WILL BE
GREATER THAN 100...AND BOTH THE 0-3 KM AND 0-6 KM SHEAR WILL BE
FAVORABLE FOR THE POSSIBILITY OF SEVERE WEATHER ALONG THE COLD
FRONT LATE SATURDAY AFTERNOON AND EVENING ALONG AND SOUTH OF THE
INTERSTATE 90 CORRIDOR.
.LONG TERM...SUNDAY THROUGH THURSDAY
345 PM CDT THU OCT 11 2012
ON SUNDAY MORNING...THE MODELS CONTINUE TO SHOW THAT THE
DEFORMATION BAND ON THE BACK SIDE OF THE LOW PRESSURE SYSTEM WILL
STILL LINGER ACROSS MUCH OF THE AREA. AS A RESULT...RAISED THE
PRECIPITATION CHANCES A BIT MORE.
BEYOND THIS TIME PERIOD...THE MODELS CONTINUE TO STRUGGLE ON THE
TIMING OF SYSTEMS AND THE UPPER FLOW. WITH THIS SAID...THERE
CONTINUES TO BE A SIGNAL FOR A STRONG LOW PRESSURE SYSTEM TO
MOVE THROUGH THE REGION ON WEDNESDAY. THIS SYSTEM IS EXPECTED TO
CARVE OUT A BROAD TROUGH ACROSS THE EASTERN CONUS WHICH WILL
RETURN COLDER AIR TO THE REGION.
&&
.AVIATION...THROUGH 18Z FRIDAY
1219 PM CDT THU OCT 11 2012
CURRENTLY WATCHING A COLD FRONT EXITING THE AREA ACROSS EASTERN
WI AND IA. ABUNDANT BKN-OVC ALTOCUMULUS WITH BASES MAINLY AOA
10KFT STILL LINGERING OVER THE AREA IN RESPONSE TO MID-LEVEL
ATMOSPHERIC FORCING. RADAR SHOWING SOME -RA ECHOES FROM THIS CLOUD
AS WELL...BUT MOSTLY VIRGA AT THIS POINT. THIS ACTIVITY IS EXPECTED
TO MOVE SOUTHEAST OF THE AREA THIS EVENING WITH CLEARING SKIES AS
HIGH PRESSURE BUILDS INTO AND OVER THE AREA TONIGHT. NORTH/NORTHWEST
DRYING FLOW EXPECTED THROUGH MIDNIGHT AND PERHAPS A FEW HOURS
AFTER UNTIL THE HIGH SETTLES OVERHEAD. THIS SHOULD PRECLUDE ANY
FOG DEVELOPMENT. THE HIGH STARTS TO DRIF EAST OF TEH REGION BY
LATE FRIDAY MORNING..S.ETTING UP AN INCREASING SOUTH FLOW MAINLY
WEST OF THE MISSISSIPPI BY AFTERNOON. OTHERWISE...VFR CONDITIONS
EXPECTED THROUGH THE PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
345 PM CDT THU OCT 11 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1219 PM CDT THU OCT 11 2012
.SHORT TERM...UPDATED FOR TODAY
942 AM CDT THU OCT 11 2012
COLD FRONT MAKING PROGRESS SOUTHWARD ACROSS THE AREA WITH MID-LEVEL
SHORTWAVE MOVING EAST ACROSS LAKE SUPERIOR. RADAR SHOWING SOME
LIGHT SHOWER/SPRINKLE ACTIVITY CURRENTLY ALONG AND IMMEDIATELY
BEHIND THE SURFACE FRONT. RAP SHOWING INCREASING FRONTOGENESIS
THIS AFTERNOON CENTERED AROUND 700MB JUXTAPOSED WITH FAVORED RIGHT
ENTRANCE REGION OF THE 300MB JET MOVING OVERHEAD. BASED ON THIS
FORCING SIGNAL...HAVE ADDED ISOLATED SHOWER MENTION ALONG AND
SOUTH OF I-90 FOR THIS AFTERNOON. TEMPERATURE-WISE...LIKELY NOT TO
SEE TOO MUCH MOVEMENT TODAY WITH CLOUD AND COLD AIR ADVECTION.
WILL HAVE UPDATED FORECAST OUT SOON.
.PREVIOUS SHORT TERM ISSUED 347 AM...THROUGH SATURDAY NIGHT
MAIN FORECAST CONCERNS THIS PACAGE...SHRA/TSRA CHANCES/RAIN AMOUNTS
FRI NIGHT THRU SAT NIGHT...TEMPERATURES THRU THE PERIOD.
DATA ANALYSIS AT 06Z HAD A WAVE OF LOW PRESSURE MOVING EAST ACROSS
CENTRAL MN. RATHER STRONG 3HR PRESSURE FALL/RISE COUPLET WITH THIS
LOW. STRONGEST OF FORCING/LIFT AND SATURATION WITH THIS FEATURE WAS
ACROSS NORTHERN MN/FAR NORTHERN WI...WHERE A BAND OF -RA/-SN WAS
MOVING QUICKLY EAST THRU THE KDLH AREA. ACROSS WEST-CENTRAL MN AND
ALONG THE SD/ND BORDER WEAK 850-700MB FN CONVERGENCE WAS PRODUCING A
BAND OF PATCHY -RA/SCT -SHRA. ALL THIS TRANSLATING EAST-SOUTHEAST
EARLY THIS MORNING. SOUTH OF THE LOW/TRAILING COLD FRONT...SKIES
WERE CLEAR ACROSS IA/FAR SOUTHERN MN INTO FAR SOUTHERN WI. BRISK/
INCREASING SOUTH WINDS AHEAD OF THE LOW/FRONT KEEPING TEMPS WARMER
EARLY THIS MORNING...EVEN UNDER THE CLEAR SKIES.
11.00Z MODELS LOOK TO HAVE INITIALIZED QUITE WELL. SOLUTIONS SIMILAR
THRU 48HRS...THEN BEGIN TO DIVERGE AS THE SOUTHWEST CONUS SYSTEM
TAKES AIM AT THE UPPER MIDWEST FOR FRI NIGHT THRU SAT NIGHT. WHAT
HAD BEEN A TIGHT CONSENSUS NOW TAKES 2 CAMPS AS THE TROUGH/ENERGY
EJECTS INTO/CROSSES THE CENTRAL CONUS. DPROG/DT OF 500MB HGTS AT
11.00Z SHOWED THE MODEL RUNS OF 09.00Z AND 10.00Z ALL VERIFIED WELL
ACROSS NOAM/EASTERN PAC...CONVERGING ON A TIGHT COMPROMISE CONSENSUS
OF THE EARLIER RUNS. SOLUTIONS SIMILAR WITH A TIGHT CONSENSUS AND
GOOD RUN-TO-RUN CONSISTENCY THRU TONIGHT. BY SAT MORNING BETWEEN
MODEL AND RUN-TO-RUN CONSISTENCY DECREASES AS THE TROUGH/LOW OF
INTEREST MOVES THRU THE ROCKIES INTO THE CENTRAL PLAINS. TREND IS
TOWARD MORE OF SPLIT OF THE SHORTWAVE ENERGY BY SAT MORNING.
SOLUTIONS CONTINUE TO DIVERGE WITH THE EVOLUTION/TRACK OF THE MID
LEVEL LOW/TROUGH AS IT LIFTS INTO THE UPPER MIDWEST BY SUN MORNING.
CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED MODELS ALL QUITE GOOD
WITH THE MN LOW AND TRAILING COLD FRONT. MODELS ALL QUITE REASONABLE
WITH THE 00-06Z PRECIP ACROSS NORTHERN MN/WI WITH GFS/ECMWF BETTER
ON THE LIGHT PRECIP OVER WEST CENTRAL MN/ALONG SD/ND BORDER. PER WV
IMAGERY ALL LOOKED GOOD WITH THE NOAM/EASTERN PAC SHORTWAVE DETAILS.
WILL LEAN TOWARD ECMWF/GFS TODAY...THEN CONTINUE TO FAVOR A MODEL/
ENSEMBLE CONSENSUS FOR TONIGHT THRU SAT NIGHT. SHORT TERM FCST
CONFIDENCE GOOD THRU FRI BUT NOW AVERAGE WITH THE STORM SYSTEM FOR
FRI NIGHT THRU SAT NIGHT.
IN THE SHORT TERM...MN LOW WILL CONTINUE TO MOVE QUICKLY EAST THIS
MORNING AND DRAG THE COLD FRONT INTO/ACROSS THE AREA. BAND OF WEAK
FORCING/850-700MB FN CONVERGENCE BEHIND THE FRONT WILL SLIDE ACROSS
THE NORTHERN PARTS OF THE FCST AREA THIS MORNING. WITH OBS UNDER
THE BAND OF PRECIP IN WEST CENTRAL MN CONTINUING TO REPORT
OCCASIONAL -RA AND GFS/ECMWF AND LCL/REGIONAL WRF MODELS PRODUCING
SOME LIGHT PRECIP IN THE NORTH END OF THE FCST AREA THIS MORNING...
EXPANDED SMALL -RA CHANCE TO ALONG/NORTH OF HWY 10 THRU 18Z. BAND
OF POST-FRONTAL CLOUDS WILL SINK SOUTH ACROSS THE AREA AS WELL AND
RAISED SKY COVER/LOWERED HIGHS A BIT FOR TODAY. CLOUDS CLEAR OUT
LATE THIS AFTERNOON/EARLY THIS EVENING AS THE SFC-850MB RIDGE BUILDS
INTO THE AREA AND MDT/STRONG 700-500MB SUBSIDENCE SPREADS OVER THE
AREA. SFC HIGH IS CENTERED OVER THE AREA AT 12Z FRI...WITH LIGHT
WINDS/CLEAR SKIES AND COOL 925-850MB TEMPS. LOOKS LIKE LOWS
EVERYWHERE WILL DROP INTO AT LAST THE 20S...WITH WIDESPREAD
FREEZING TEMPS FINALLY ENDING THE GROWING SEASON IN THOSE ISOLATED
LOCATIONS THAT HAVE ESCAPED FROST/FREEZING SO FAR THIS FALL.
FROST/FREEZE HEADLINES HAVE BEEN TERMINATED FOR THE SEASON...SO NO
HEADLINE WILL BE ISSUED FOR LATE TONIGHT/EARLY FRI MORNING.
THE HIGH MOVES QUICKLY EAST OF THE AREA FRI AS LEE TROUGHING
DEVELOPS FROM MT TO CO. BROAD LOW LEVEL WARM ADVECTION ALREADY
SPREADS ACROSS THE AREA FRI AS THE GRADIENT TIGHTENS...WITH 925MB
TEMPS IN THE +4 TO +7C RANGE BY 00Z SAT. AIRMASS OVER THE AREA
REMAINS DRY THRU FRI...WITH PLENTY OF SUNSHINE AND A DIURNAL TEMP
RISE OF SOME 25-30F FOR MOST AREAS.
LEAD 925-700MB WARM ADVECTION/ISENTROPIC LIFT AND MOISTURE
TRANSPORT/THETA-E CONVERGENCE SPREAD QUICKLY NORTHEAST ACROSS THE
AREA FRI NIGHT. MODELS ALL REMAIN QUITE CONSISTENT WITH THIS
SIGNAL. PREVIOUS GRID SET TRENDED THE 00-03Z PERIOD FRI EVENING
DRY AND THIS LOOKS GOOD...WITH THE MOISTURE/LIFT ARRIVING AROUND
MIDNIGHT. WITH THE CONSISTENT MOISTURE/WARM ADVECTION SIGNAL RAISED
RAIN CHANCES TO 60-90 PERCENT AFTER MIDNIGHT FRI NIGHT. GIVEN THE
STRENGTH OF THE LIFT AND MODELS SHOWING SOME CAPE LIFTING PARCELS IN
THE 800-700MB LAYER...SOME THUNDER LOOKS TO ACCOMPANY THE SHRA AS
THEY LIFT NORTHEAST ACROSS THE AREA FROM LATE EVENING ON.
ON SAT MODELS BEGIN TO DIFFER ON THE DETAILS OF WHERE THE STRONGER
FORCING/LIFT WILL MOVE ACROSS THE FCST AREA. SPLITTING GFS SOLUTION
KEEPS THE STRONGER FORCING OVER THE SOUTHEAST HALF OF THE FCST AREA
SAT INTO SAT NIGHT WHILE OTHER MODELS CONTINUE TO SPREAD STRONG
FORCING ACROSS THE ENTIRE FCST AREA AS THE SFC-MID LEVEL TROUGH
MOVES INTO/ACROSS THE REGION. 90-100 PERCENT SHRA/TSRA CHANCES
ACROSS THE FCST AREA SAT STILL LOOK WARRANTED. DEEPER OF THE
MOISTURE LIFT DOES MOVE EAST OF THE AREA SAT NIGHT. CARRIED HIGHEST
SHRA/TSRA CHANCES OF 60-90 PERCENT SAT EVENING...TRENDING DOWNWARD
AFTER MIDNIGHT AS THE MID LEVEL TROUGH AXIS PASSES.
HIGH TEMPS ON SAT...RESULTING INSTABILITY AND SEVERE TSRA RISK
REMAIN THE SOME OF THE MORE UNCERTAIN ELEMENTS AS THIS SYSTEM
PASSES. MODEL SOUNDINGS FOR SAT SHOW EITHER A DEEPLY SATURATED
COLUMN OR AT LEAST SATURATED BELOW 800MB. FCST GRIDS ARE CARRYING
CLOUDY SKIES SAT...AND THIS BLENDS WILL WITH ALL NEIGHBORS. STILL
APPEARS THE SFC LOW AND ATTENDANT FRONTS WILL BE WEST/NORTH OF THE
FCST AREA UNTIL AFTER 00Z SUN. THIS LIKELY TO LIMIT BOUNDARY LAYER
INVOLVEMENT IN THE SEVERE STORM RISK. APPEARS STRONGER INSTABILITY
OF UP TO 500-1000 J/KG WILL BE ELEVATED. GIVEN THE BROAD FORCING
FOR ASCENT AHEAD OF THE SFC-MID LEVEL TROUGH AND STRONGER SHEAR...
ISOLATED SEVERE TSRA CANNOT BE RULED OUT WITH SWODY3 OKAY FOR NOW.
PW VALUES STILL PROGGED TO BE IN THE 1.5 INCH RANGE LATE FRI NIGHT
INTO SAT EVENING...WITH ANY TSRA CAPABLE OF PRODUCING HEAVY
DOWNPOURS. WITH THE ANTECEDENT DRY CONDITIONS...ANY FLOODING OR
FLASH FLOODING THREAT LOOKS MINIMAL.
GENERALLY FAVORED A BLEND OF THE NUMERICAL GUIDANCE HIGHS/LOWS FOR
TODAY THRU SAT NIGHT. WITH PLENTY OF CLOUDS/SHRA/TSRA EXPECTED
SAT...DID FAVOR COOLER OF GUIDANCE HIGHS.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
347 AM CDT THU OCT 11 2012
11.00Z MEDIUM RANGE MODELS SHOW THE TROUGH/LOW TO BE PROGRESSIVE
SUNDAY...EXITING EAST OF THE AREA BY AFTERNOON. LIMITED SHRA
CHANCES SUN MAINLY TO THE MORNING HOURS. DECENT MODEL CONSISTENCY
FOR BROAD 500MB TROUGHING TO REMAIN OVER THE AREA THRU SUN NIGHT.
ECMWF DROPS A STRONGER SHORTWAVE ACROSS THE AREA IN NORTHWEST FLOW
SUN NIGHT...AND LEFT A SMALL -RA CHANCE ACROSS THE NORTH END OF THE
FCST AREA. MODERATE CONSENSUS FOR WEAK SHORTWAVE RIDGING TO BUILD
THE AREA MON FOR A DRY DAY. PATTERN REMAINS UNSETTLED THRU THE
MIDDLE OF NEXT WEEK AS THE FLOW BECOMES QUASI-ZONAL ACROSS THE
NORTHERN CONUS AND MODELS STRUGGLE WITH THE TIMING/STRENGTH OF
SHORTWAVES THRU THE FLOW. LOOSE CONSENSUS FOR A STRONGER SHORTWAVE
TO CARVE OUT A TROUGH OVER THE UPPER MIDWEST BY WED. SOME SHRA
CHANCES IN THE 20-40 PERCENT RANGE TUE NIGHT/WED...PER THE
MODEL/ENSEMBLE CONSENSUS...LOOK GOOD FOR NOW. WITH THE MORE EAST-
WEST FLOW AND MAIN STORM TRACK ALONG THE US/CAN BORDER...TEMPS FOR
SUN-WED CONTINUE TO TREND NEAR OR ABOVE NORMAL AND THIS WELL
DEPICTED BY THE MODEL CONSENSUS GRID SET.
&&
.AVIATION...THROUGH 18Z FRIDAY
1219 PM CDT THU OCT 11 2012
CURRENTLY WATCHING A COLD FRONT EXITING THE AREA ACROSS EASTERN
WI AND IA. ABUNDANT BKN-OVC ALTOCUMULUS WITH BASES MAINLY AOA
10KFT STILL LINGERING OVER THE AREA IN RESPONSE TO MID-LEVEL
ATMOSPHERIC FORCING. RADAR SHOWING SOME -RA ECHOES FROM THIS CLOUD
AS WELL...BUT MOSTLY VIRGA AT THIS POINT. THIS ACTIVITY IS EXPECTED
TO MOVE SOUTHEAST OF THE AREA THIS EVENING WITH CLEARING SKIES AS
HIGH PRESSURE BUILDS INTO AND OVER THE AREA TONIGHT. NORTH/NORTHWEST
DRYING FLOW EXPECTED THROUGH MIDNIGHT AND PERHAPS A FEW HOURS
AFTER UNTIL THE HIGH SETTLES OVERHEAD. THIS SHOULD PRECLUDE ANY
FOG DEVELOPMENT. THE HIGH STARTS TO DRIF EAST OF TEH REGION BY
LATE FRIDAY MORNING..S.ETTING UP AN INCREASING SOUTH FLOW MAINLY
WEST OF THE MISSISSIPPI BY AFTERNOON. OTHERWISE...VFR CONDITIONS
EXPECTED THROUGH THE PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
347 AM CDT THU OCT 11 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATED SHORT TERM...DAS
LONG TERM....RRS
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
942 AM CDT THU OCT 11 2012
.SHORT TERM...UPDATED FOR TODAY
942 AM CDT THU OCT 11 2012
COLD FRONT MAKING PROGRESS SOUTHWARD ACROSS THE AREA WITH MID-LEVEL
SHORTWAVE MOVING EAST ACROSS LAKE SUPERIOR. RADAR SHOWING SOME
LIGHT SHOWER/SPRINKLE ACTIVITY CURRENTLY ALONG AND IMMEDIATELY
BEHIND THE SURFACE FRONT. RAP SHOWING INCREASING FRONTOGENESIS
THIS AFTERNOON CENTERED AROUND 700MB JUXTAPOSED WITH FAVORED RIGHT
ENTRANCE REGION OF THE 300MB JET MOVING OVERHEAD. BASED ON THIS
FORCING SIGNAL...HAVE ADDED ISOLATED SHOWER MENTION ALONG AND
SOUTH OF I-90 FOR THIS AFTERNOON. TEMPERATURE-WISE...LIKELY NOT TO
SEE TOO MUCH MOVEMENT TODAY WITH CLOUD AND COLD AIR ADVECTION.
WILL HAVE UPDATED FORECAST OUT SOON.
.PREVIOUS SHORT TERM ISSUED 347 AM...THROUGH SATURDAY NIGHT
MAIN FORECAST CONCERNS THIS PACAGE...SHRA/TSRA CHANCES/RAIN AMOUNTS
FRI NIGHT THRU SAT NIGHT...TEMPERATURES THRU THE PERIOD.
DATA ANALYSIS AT 06Z HAD A WAVE OF LOW PRESSURE MOVING EAST ACROSS
CENTRAL MN. RATHER STRONG 3HR PRESSURE FALL/RISE COUPLET WITH THIS
LOW. STRONGEST OF FORCING/LIFT AND SATURATION WITH THIS FEATURE WAS
ACROSS NORTHERN MN/FAR NORTHERN WI...WHERE A BAND OF -RA/-SN WAS
MOVING QUICKLY EAST THRU THE KDLH AREA. ACROSS WEST-CENTRAL MN AND
ALONG THE SD/ND BORDER WEAK 850-700MB FN CONVERGENCE WAS PRODUCING A
BAND OF PATCHY -RA/SCT -SHRA. ALL THIS TRANSLATING EAST-SOUTHEAST
EARLY THIS MORNING. SOUTH OF THE LOW/TRAILING COLD FRONT...SKIES
WERE CLEAR ACROSS IA/FAR SOUTHERN MN INTO FAR SOUTHERN WI. BRISK/
INCREASING SOUTH WINDS AHEAD OF THE LOW/FRONT KEEPING TEMPS WARMER
EARLY THIS MORNING...EVEN UNDER THE CLEAR SKIES.
11.00Z MODELS LOOK TO HAVE INITIALIZED QUITE WELL. SOLUTIONS SIMILAR
THRU 48HRS...THEN BEGIN TO DIVERGE AS THE SOUTHWEST CONUS SYSTEM
TAKES AIM AT THE UPPER MIDWEST FOR FRI NIGHT THRU SAT NIGHT. WHAT
HAD BEEN A TIGHT CONSENSUS NOW TAKES 2 CAMPS AS THE TROUGH/ENERGY
EJECTS INTO/CROSSES THE CENTRAL CONUS. DPROG/DT OF 500MB HGTS AT
11.00Z SHOWED THE MODEL RUNS OF 09.00Z AND 10.00Z ALL VERIFIED WELL
ACROSS NOAM/EASTERN PAC...CONVERGING ON A TIGHT COMPROMISE CONSENSUS
OF THE EARLIER RUNS. SOLUTIONS SIMILAR WITH A TIGHT CONSENSUS AND
GOOD RUN-TO-RUN CONSISTENCY THRU TONIGHT. BY SAT MORNING BETWEEN
MODEL AND RUN-TO-RUN CONSISTENCY DECREASES AS THE TROUGH/LOW OF
INTEREST MOVES THRU THE ROCKIES INTO THE CENTRAL PLAINS. TREND IS
TOWARD MORE OF SPLIT OF THE SHORTWAVE ENERGY BY SAT MORNING.
SOLUTIONS CONTINUE TO DIVERGE WITH THE EVOLUTION/TRACK OF THE MID
LEVEL LOW/TROUGH AS IT LIFTS INTO THE UPPER MIDWEST BY SUN MORNING.
CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED MODELS ALL QUITE GOOD
WITH THE MN LOW AND TRAILING COLD FRONT. MODELS ALL QUITE REASONABLE
WITH THE 00-06Z PRECIP ACROSS NORTHERN MN/WI WITH GFS/ECMWF BETTER
ON THE LIGHT PRECIP OVER WEST CENTRAL MN/ALONG SD/ND BORDER. PER WV
IMAGERY ALL LOOKED GOOD WITH THE NOAM/EASTERN PAC SHORTWAVE DETAILS.
WILL LEAN TOWARD ECMWF/GFS TODAY...THEN CONTINUE TO FAVOR A MODEL/
ENSEMBLE CONSENSUS FOR TONIGHT THRU SAT NIGHT. SHORT TERM FCST
CONFIDENCE GOOD THRU FRI BUT NOW AVERAGE WITH THE STORM SYSTEM FOR
FRI NIGHT THRU SAT NIGHT.
IN THE SHORT TERM...MN LOW WILL CONTINUE TO MOVE QUICKLY EAST THIS
MORNING AND DRAG THE COLD FRONT INTO/ACROSS THE AREA. BAND OF WEAK
FORCING/850-700MB FN CONVERGENCE BEHIND THE FRONT WILL SLIDE ACROSS
THE NORTHERN PARTS OF THE FCST AREA THIS MORNING. WITH OBS UNDER
THE BAND OF PRECIP IN WEST CENTRAL MN CONTINUING TO REPORT
OCCASIONAL -RA AND GFS/ECMWF AND LCL/REGIONAL WRF MODELS PRODUCING
SOME LIGHT PRECIP IN THE NORTH END OF THE FCST AREA THIS MORNING...
EXPANDED SMALL -RA CHANCE TO ALONG/NORTH OF HWY 10 THRU 18Z. BAND
OF POST-FRONTAL CLOUDS WILL SINK SOUTH ACROSS THE AREA AS WELL AND
RAISED SKY COVER/LOWERED HIGHS A BIT FOR TODAY. CLOUDS CLEAR OUT
LATE THIS AFTERNOON/EARLY THIS EVENING AS THE SFC-850MB RIDGE BUILDS
INTO THE AREA AND MDT/STRONG 700-500MB SUBSIDENCE SPREADS OVER THE
AREA. SFC HIGH IS CENTERED OVER THE AREA AT 12Z FRI...WITH LIGHT
WINDS/CLEAR SKIES AND COOL 925-850MB TEMPS. LOOKS LIKE LOWS
EVERYWHERE WILL DROP INTO AT LAST THE 20S...WITH WIDESPREAD
FREEZING TEMPS FINALLY ENDING THE GROWING SEASON IN THOSE ISOLATED
LOCATIONS THAT HAVE ESCAPED FROST/FREEZING SO FAR THIS FALL.
FROST/FREEZE HEADLINES HAVE BEEN TERMINATED FOR THE SEASON...SO NO
HEADLINE WILL BE ISSUED FOR LATE TONIGHT/EARLY FRI MORNING.
THE HIGH MOVES QUICKLY EAST OF THE AREA FRI AS LEE TROUGHING
DEVELOPS FROM MT TO CO. BROAD LOW LEVEL WARM ADVECTION ALREADY
SPREADS ACROSS THE AREA FRI AS THE GRADIENT TIGHTENS...WITH 925MB
TEMPS IN THE +4 TO +7C RANGE BY 00Z SAT. AIRMASS OVER THE AREA
REMAINS DRY THRU FRI...WITH PLENTY OF SUNSHINE AND A DIURNAL TEMP
RISE OF SOME 25-30F FOR MOST AREAS.
LEAD 925-700MB WARM ADVECTION/ISENTROPIC LIFT AND MOISTURE
TRANSPORT/THETA-E CONVERGENCE SPREAD QUICKLY NORTHEAST ACROSS THE
AREA FRI NIGHT. MODELS ALL REMAIN QUITE CONSISTENT WITH THIS
SIGNAL. PREVIOUS GRID SET TRENDED THE 00-03Z PERIOD FRI EVENING
DRY AND THIS LOOKS GOOD...WITH THE MOISTURE/LIFT ARRIVING AROUND
MIDNIGHT. WITH THE CONSISTENT MOISTURE/WARM ADVECTION SIGNAL RAISED
RAIN CHANCES TO 60-90 PERCENT AFTER MIDNIGHT FRI NIGHT. GIVEN THE
STRENGTH OF THE LIFT AND MODELS SHOWING SOME CAPE LIFTING PARCELS IN
THE 800-700MB LAYER...SOME THUNDER LOOKS TO ACCOMPANY THE SHRA AS
THEY LIFT NORTHEAST ACROSS THE AREA FROM LATE EVENING ON.
ON SAT MODELS BEGIN TO DIFFER ON THE DETAILS OF WHERE THE STRONGER
FORCING/LIFT WILL MOVE ACROSS THE FCST AREA. SPLITTING GFS SOLUTION
KEEPS THE STRONGER FORCING OVER THE SOUTHEAST HALF OF THE FCST AREA
SAT INTO SAT NIGHT WHILE OTHER MODELS CONTINUE TO SPREAD STRONG
FORCING ACROSS THE ENTIRE FCST AREA AS THE SFC-MID LEVEL TROUGH
MOVES INTO/ACROSS THE REGION. 90-100 PERCENT SHRA/TSRA CHANCES
ACROSS THE FCST AREA SAT STILL LOOK WARRANTED. DEEPER OF THE
MOISTURE LIFT DOES MOVE EAST OF THE AREA SAT NIGHT. CARRIED HIGHEST
SHRA/TSRA CHANCES OF 60-90 PERCENT SAT EVENING...TRENDING DOWNWARD
AFTER MIDNIGHT AS THE MID LEVEL TROUGH AXIS PASSES.
HIGH TEMPS ON SAT...RESULTING INSTABILITY AND SEVERE TSRA RISK
REMAIN THE SOME OF THE MORE UNCERTAIN ELEMENTS AS THIS SYSTEM
PASSES. MODEL SOUNDINGS FOR SAT SHOW EITHER A DEEPLY SATURATED
COLUMN OR AT LEAST SATURATED BELOW 800MB. FCST GRIDS ARE CARRYING
CLOUDY SKIES SAT...AND THIS BLENDS WILL WITH ALL NEIGHBORS. STILL
APPEARS THE SFC LOW AND ATTENDANT FRONTS WILL BE WEST/NORTH OF THE
FCST AREA UNTIL AFTER 00Z SUN. THIS LIKELY TO LIMIT BOUNDARY LAYER
INVOLVEMENT IN THE SEVERE STORM RISK. APPEARS STRONGER INSTABILITY
OF UP TO 500-1000 J/KG WILL BE ELEVATED. GIVEN THE BROAD FORCING
FOR ASCENT AHEAD OF THE SFC-MID LEVEL TROUGH AND STRONGER SHEAR...
ISOLATED SEVERE TSRA CANNOT BE RULED OUT WITH SWODY3 OKAY FOR NOW.
PW VALUES STILL PROGGED TO BE IN THE 1.5 INCH RANGE LATE FRI NIGHT
INTO SAT EVENING...WITH ANY TSRA CAPABLE OF PRODUCING HEAVY
DOWNPOURS. WITH THE ANTECEDENT DRY CONDITIONS...ANY FLOODING OR
FLASH FLOODING THREAT LOOKS MINIMAL.
GENERALLY FAVORED A BLEND OF THE NUMERICAL GUIDANCE HIGHS/LOWS FOR
TODAY THRU SAT NIGHT. WITH PLENTY OF CLOUDS/SHRA/TSRA EXPECTED
SAT...DID FAVOR COOLER OF GUIDANCE HIGHS.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
347 AM CDT THU OCT 11 2012
11.00Z MEDIUM RANGE MODELS SHOW THE TROUGH/LOW TO BE PROGRESSIVE
SUNDAY...EXITING EAST OF THE AREA BY AFTERNOON. LIMITED SHRA
CHANCES SUN MAINLY TO THE MORNING HOURS. DECENT MODEL CONSISTENCY
FOR BROAD 500MB TROUGHING TO REMAIN OVER THE AREA THRU SUN NIGHT.
ECMWF DROPS A STRONGER SHORTWAVE ACROSS THE AREA IN NORTHWEST FLOW
SUN NIGHT...AND LEFT A SMALL -RA CHANCE ACROSS THE NORTH END OF THE
FCST AREA. MODERATE CONSENSUS FOR WEAK SHORTWAVE RIDGING TO BUILD
THE AREA MON FOR A DRY DAY. PATTERN REMAINS UNSETTLED THRU THE
MIDDLE OF NEXT WEEK AS THE FLOW BECOMES QUASI-ZONAL ACROSS THE
NORTHERN CONUS AND MODELS STRUGGLE WITH THE TIMING/STRENGTH OF
SHORTWAVES THRU THE FLOW. LOOSE CONSENSUS FOR A STRONGER SHORTWAVE
TO CARVE OUT A TROUGH OVER THE UPPER MIDWEST BY WED. SOME SHRA
CHANCES IN THE 20-40 PERCENT RANGE TUE NIGHT/WED...PER THE
MODEL/ENSEMBLE CONSENSUS...LOOK GOOD FOR NOW. WITH THE MORE EAST-
WEST FLOW AND MAIN STORM TRACK ALONG THE US/CAN BORDER...TEMPS FOR
SUN-WED CONTINUE TO TREND NEAR OR ABOVE NORMAL AND THIS WELL
DEPICTED BY THE MODEL CONSENSUS GRID SET.
&&
.AVIATION...TODAY AND TONIGHT
645 AM CDT THU OCT 11 2012
A LOW PRESSURE SYSTEM AND COLD FRONT ARE MOVING THROUGH THE REGION
WITH THE FRONT PASSING THROUGH RST AND LSE THIS MORNING. A FEW
SPRINKLES HAVE BEEN REPORTED THOUGH THEY SHOULD NOT CAUSE ANY
VISIBILITY RESTRICTIONS AT EITHER TERMINAL. CLOUD COVER IS THE
MAIN QUESTION...PARTICULARLY WITH IF ANY MVFR CEILINGS CAN MAKE IT
INTO RST/LSE. LOCAL OBSERVATIONS AND FORECAST GUIDANCE SUGGEST
THAT THE BATCH OF MVFR 2-3KFT CEILINGS SHOULD STAY NORTH OF THE
TWIN CITIES AND TRACK EAST ALONG WITH THE SYSTEM.
OTHERWISE...WINDS WILL SWING AROUND TO THE NORTHWEST AS THE FRONT
PASSES AND REMAIN GUSTY UP TO AROUND 20KTS TODAY. A RIDGE OF HIGH
PRESSURE WILL MOVE INTO THE REGION TONIGHT WHICH WILL HELP TO
CLEAR OUT THE SKIES AND LIGHTEN THE WINDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
347 AM CDT THU OCT 11 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATED SHORT TERM...DAS
PREVIOUS SHORT TERM...RRS
LONG TERM....RRS
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1259 PM MDT THU OCT 11 2012
.AVIATION...18Z TAFS. VFR PREVAILS. PERIODS OF SCATTERED MIDDLE
AND HIGH LEVEL CLOUDINESS. SURFACE HIGH PRESSURE MOVES SOUTHEAST
TO EASTERN NORTH DAKOTA THIS AFTERNOON...THEN FURTHER EAST
PRODUCING RETURN SOUTH WINDS ACROSS TAF SITES TONIGHT. SCATTERED
TO BROKEN IFR CEILINGS DEVELOPING BETWEEN 10Z AND 15Z EAST OF
INTERSTATE 25 ON MOIST LOW LEVEL SOUTH WINDS. LOW CLOUDS
DISSIPATING AROUND 15Z. RUBIN
&&
.PREV DISCUSSION... /ISSUED 1010 AM MDT THU OCT 11 2012/
UPDATE...
CURRENT OBS SHOW MVFR CIGS OVER THE NORTHERN HALF OF THE NEBRASKA
PANHANDLE. SOME OF THESE LOW CLOUDS ARE ALSO MOVING INTO EAST
SECTIONS OF GOSHEN AND NIOBRARA COUNTIES. THE HRRR MODEL SHOWS LOW
CLOUDS PERSISTING INTO 20-21Z OVER THE PANHANDLE BUT NOT MAKING
MUCH HEADWAY INTO SOUTHEAST WYOMING. COOLED TEMPS AND INCREASED
CLOUD COVER OVER THE PANHANDLE WITH THE EXPECTATION THAT CLOUDS WILL
BE PERSISTENT THROUGH THE EARLY AFTERNOON.
PREV DISCUSSION... /ISSUED 526 AM MDT THU OCT 11 2012/
AVIATION...12Z TAF ISSUANCE...
VFR EXPECTED OVER ALL TERMINALS THROUGH FRIDAY MORNING THOUGH A
BRIEF PERIOD OF MVFR CIGS STILL POSSIBLE THIS MORNING VCTY KCDR.
SFC COLD FRONT WILL PUSH UP AGAINST THE WY MTNS THIS MORNING THEN
BECOME STNRY THROUGH TONIGHT. WESTERLY FLOW ALOFT THROUGH TONIGHT.
PREV DISCUSSION... /ISSUED 302 AM MDT THU OCT 11 2012/
SHORT TERM...TODAY THROUGH SUNDAY MORNING
FORECAST CHALLENGE DEALS WITH PACIFIC LOW PRESSURE SYSTEM FRIDAY
INTO SATURDAY. SPECIFICALLY...SNOW AMOUNTS AND WINDS.
CURRENTLY...COLD FRONT SAGGING SOUTH INTO EASTERN WYOMING THIS
MORNING. TO THE WEST...LOW PRESSURE OFF THE COAST OF NORTHERN
CALIFORNIA WILL BE OUR NEXT WEATHER PRODUCER...CURRENTLY COMING
ASHORE SOUTH OF SAN FRANCISCO. SEVERAL LIGHTNING STRIKES BEING
OBSERVED WITH THIS SYSTEM.
ATTENTION TURNS TO FRIDAY AS THIS LOW TRACKS INTO WESTERN COLORADO
FRIDAY AFTERNOON. GOOD POSITION FOR US AS WE SET UP GOOD DIFFLUENT
UPPER LEVEL FLOW AND PRECIP SPREADS INTO THE AREA FRIDAY EVENING.
VERY STRONG ISENTROPIC LIFT FORECAST AT ALL LEVELS FRIDAY NIGHT
INTO SATURDAY. ALL MODELS SHOWING HEFTY QPF WITH THIS STORM SYSTEM
WITH FREEZING LEVELS DROPPING TO 9K FEET OR SO. WENT AHEAD WITH A
WINTER STORM WATCH FOR FRIDAY NIGHT THROUGH SATURDAY FOR THE SNOWY
AND SIERRA MADRE RANGES. THIS SYSTEM VERY SIMILAR TO LAST OCTOBERS
SNOW STORM AND WE REALLY NEED TO WATCH TEMPERATURES. WENT BELOW
GUIDANCE ON TEMPERATURES FOR FRIDAY INTO SATURDAY. HAVE A FEELING
THAT I DID NOT GO LOW ENOUGH...BUT WILL CONTINUE TO MONITOR. IF WE
DO COME IN COLDER...WE COULD SEE WINTER STORM CONDITIONS OVER THE
SOUTHERN LARAMIE RANGE. FOR NOW...KEPT THESE ZONES OUT OF THE
WATCH WITH 3 TO 5 INCHES UP THERE.
WINDS BECOME VERY STRONG FRIDAY NIGHT INTO SATURDAY AS WELL. GFS
SHOWING 50KTS AT 700MBS. WENT AHEAD WITH A HIGH WIND WATCH FOR THE
REST OF CARBON AND ALBANY COUNTIES AS WELL AS BORDEAUX FOR THIS
EVENT. LATEST NAM GUIDANCE SHOWING 28KTS SUSTAINED AT RWL FRIDAY
NIGHT AROUND THE 09Z TIME FRAME. WIND DIE DOWN QUICKLY AFTER 12Z
SATURDAY AS THE LOW TRACKS EAST...SO THERE LOOKS TO BE A 6-12 HOUR
WINDOW FRIDAY EVENING WHERE WE COULD SEE THESE STRONG WINDS.
MOST LOCATIONS SHOULD SEE WETTING RAINS WITH THIS EVENT AS A
TROWAL TYPE SIGNATURE SETS UP OVER THE CWFA. THERE ARE SOME
DIFFERENCES IN MODELS ON QPF PLACEMENT WITH THE NAM FURTHER NORTH
THAN THE GFS AND ECMWF. BEST CHANCES FOR PRECIP LOOK TO BE ACROSS
THE SOUTHERN PANHANDLE AND NEAR THE STATE LINE WITH COLORADO.
PRECIP AMOUNTS COULD APPROACH AN INCH IN SOME SPOTS NEAR THE
COLORADO BORDER...INCLUDING CHEYENNE.
UPPER LOW OPENS UP SATURDAY MORNING AND TRACKS QUICKLY NORTHEAST
SATURDAY AFTERNOON. PRECIP TO COME TO AN END SATURDAY AFTERNOON
FOR MOST LOCATIONS.
LONG TERM...SUNDAY THROUGH WEDNESDAY...
PATTERN ACROSS THE AREA THIS PERIOD WILL BE CHARACTERIZED BY
FAIRLY FAST WNW TO NW FLOW ALOFT WITH A COUPLE OF WEAK
DISTURBANCES PASSING ACROSS IN THIS FLOW. TEMPERATURES WILL BE
MILD AS THESE DISTURBANCES WILL BE OF PACIFIC ORIGIN AND NOT HAVE
MUCH IN THE WAY OF COLD AIR WITH THEIR ASSOCIATED FRONTS. BREEZY
TO WINDY PERIODS SHOULD OCCUR AS THE SYSTEMS CAUSE LEE TROFFING TO
DEEPEN AND INCREASE THE PRESSURE GRADIENT...PARTICULARLY MONDAY
INTO TUESDAY. MAINLY DRY OUTSIDE OF THE MTNS WITH DOWNSLOPING FLOW
BEING PREDOMINANT. SOME SHOWERS SHOULD OCCUR OVER THE MTNS WHERE
OROGRAPHICS INTERACT WITH PERIODS OF ENHANCED MOISTURE IN THE
FLOW.
FIRE WEATHER...
COLD FRONT TO SAG DOWN INTO SOUTHEAST WYOMING TODAY...BRINGING
HIGHER DEWPOINTS AND COOLER TEMPERATURES TO AT LEAST THOSE ZONES
EAST OF THE LARAMIE RANGE. GOING TO SEE AN INCREASE IN CLOUDS AND
MOISTURE FRIDAY AS A STRONG PACIFIC STORM SYSTEM TRACKS THROUGH
NORTHERN COLORADO INTO THE PANHANDLE...BRINGING A VERY GOOD CHANCE
OF WETTING VALLEY RAINS AND MOUNTAIN SNOWS. VERY STRONG WINDS
BEHIND THE LOW FRIDAY NIGHT INTO SATURDAY AS THE LOW TRACKS INTO
THE PANHANDLE. WINDS TO CONTINUE INTO SUNDAY BEFORE EASING.
ANOTHER WIND EVENT IN THE OFFING MONDAY AFTERNOON AND PERSISTING
INTO WEDNESDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM 6 PM FRIDAY TO 6 PM SATURDAY FOR WYZ112-
WYZ114.
HIGH WIND WATCH FROM 6 PM FRIDAY TO 6 AM SATURDAY FOR WYZ104-
WYZ105-WYZ106-WYZ109-WYZ110-WYZ111-WYZ115-WYZ116.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...CLAYCOMB
LONG TERM/AVIATION...RE
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1010 AM MDT THU OCT 11 2012
.UPDATE...
CURRENT OBS SHOW MVFR CIGS OVER THE NORTHERN HALF OF THE NEBRASKA
PANHANDLE. SOME OF THESE LOW CLOUDS ARE ALSO MOVING INTO EAST
SECTIONS OF GOSHEN AND NIOBRARA COUNTIES. THE HRRR MODEL SHOWS LOW
CLOUDS PERSISTING INTO 20-21Z OVER THE PANHANDLE BUT NOT MAKING
MUCH HEADWAY INTO SOUTHEAST WYOMING. COOLED TEMPS AND INCREASED
CLOUD COVER OVER THE PANHANDLE WITH THE EXPECTATION THAT CLOUDS WILL
BE PERSISTENT THROUGH THE EARLY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 526 AM MDT THU OCT 11 2012/
AVIATION...12Z TAF ISSUANCE...
VFR EXPECTED OVER ALL TERMINALS THROUGH FRIDAY MORNING THOUGH A
BRIEF PERIOD OF MVFR CIGS STILL POSSIBLE THIS MORNING VCTY KCDR.
SFC COLD FRONT WILL PUSH UP AGAINST THE WY MTNS THIS MORNING THEN
BECOME STNRY THROUGH TONIGHT. WESTERLY FLOW ALOFT THROUGH TONIGHT.
PREV DISCUSSION... /ISSUED 302 AM MDT THU OCT 11 2012/
SHORT TERM...TODAY THROUGH SUNDAY MORNING
FORECAST CHALLENGE DEALS WITH PACIFIC LOW PRESSURE SYSTEM FRIDAY
INTO SATURDAY. SPECIFICALLY...SNOW AMOUNTS AND WINDS.
CURRENTLY...COLD FRONT SAGGING SOUTH INTO EASTERN WYOMING THIS
MORNING. TO THE WEST...LOW PRESSURE OFF THE COAST OF NORTHERN
CALIFORNIA WILL BE OUR NEXT WEATHER PRODUCER...CURRENTLY COMING
ASHORE SOUTH OF SAN FRANCISCO. SEVERAL LIGHTNING STRIKES BEING
OBSERVED WITH THIS SYSTEM.
ATTENTION TURNS TO FRIDAY AS THIS LOW TRACKS INTO WESTERN COLORADO
FRIDAY AFTERNOON. GOOD POSITION FOR US AS WE SET UP GOOD DIFFLUENT
UPPER LEVEL FLOW AND PRECIP SPREADS INTO THE AREA FRIDAY EVENING.
VERY STRONG ISENTROPIC LIFT FORECAST AT ALL LEVELS FRIDAY NIGHT
INTO SATURDAY. ALL MODELS SHOWING HEFTY QPF WITH THIS STORM SYSTEM
WITH FREEZING LEVELS DROPPING TO 9K FEET OR SO. WENT AHEAD WITH A
WINTER STORM WATCH FOR FRIDAY NIGHT THROUGH SATURDAY FOR THE SNOWY
AND SIERRA MADRE RANGES. THIS SYSTEM VERY SIMILAR TO LAST OCTOBERS
SNOW STORM AND WE REALLY NEED TO WATCH TEMPERATURES. WENT BELOW
GUIDANCE ON TEMPERATURES FOR FRIDAY INTO SATURDAY. HAVE A FEELING
THAT I DID NOT GO LOW ENOUGH...BUT WILL CONTINUE TO MONITOR. IF WE
DO COME IN COLDER...WE COULD SEE WINTER STORM CONDITIONS OVER THE
SOUTHERN LARAMIE RANGE. FOR NOW...KEPT THESE ZONES OUT OF THE
WATCH WITH 3 TO 5 INCHES UP THERE.
WINDS BECOME VERY STRONG FRIDAY NIGHT INTO SATURDAY AS WELL. GFS
SHOWING 50KTS AT 700MBS. WENT AHEAD WITH A HIGH WIND WATCH FOR THE
REST OF CARBON AND ALBANY COUNTIES AS WELL AS BORDEAUX FOR THIS
EVENT. LATEST NAM GUIDANCE SHOWING 28KTS SUSTAINED AT RWL FRIDAY
NIGHT AROUND THE 09Z TIME FRAME. WIND DIE DOWN QUICKLY AFTER 12Z
SATURDAY AS THE LOW TRACKS EAST...SO THERE LOOKS TO BE A 6-12 HOUR
WINDOW FRIDAY EVENING WHERE WE COULD SEE THESE STRONG WINDS.
MOST LOCATIONS SHOULD SEE WETTING RAINS WITH THIS EVENT AS A
TROWAL TYPE SIGNATURE SETS UP OVER THE CWFA. THERE ARE SOME
DIFFERENCES IN MODELS ON QPF PLACEMENT WITH THE NAM FURTHER NORTH
THAN THE GFS AND ECMWF. BEST CHANCES FOR PRECIP LOOK TO BE ACROSS
THE SOUTHERN PANHANDLE AND NEAR THE STATE LINE WITH COLORADO.
PRECIP AMOUNTS COULD APPROACH AN INCH IN SOME SPOTS NEAR THE
COLORADO BORDER...INCLUDING CHEYENNE.
UPPER LOW OPENS UP SATURDAY MORNING AND TRACKS QUICKLY NORTHEAST
SATURDAY AFTERNOON. PRECIP TO COME TO AN END SATURDAY AFTERNOON
FOR MOST LOCATIONS.
LONG TERM...SUNDAY THROUGH WEDNESDAY...
PATTERN ACROSS THE AREA THIS PERIOD WILL BE CHARACTERIZED BY
FAIRLY FAST WNW TO NW FLOW ALOFT WITH A COUPLE OF WEAK
DISTURBANCES PASSING ACROSS IN THIS FLOW. TEMPERATURES WILL BE
MILD AS THESE DISTURBANCES WILL BE OF PACIFIC ORIGIN AND NOT HAVE
MUCH IN THE WAY OF COLD AIR WITH THEIR ASSOCIATED FRONTS. BREEZY
TO WINDY PERIODS SHOULD OCCUR AS THE SYSTEMS CAUSE LEE TROFFING TO
DEEPEN AND INCREASE THE PRESSURE GRADIENT...PARTICULARLY MONDAY
INTO TUESDAY. MAINLY DRY OUTSIDE OF THE MTNS WITH DOWNSLOPING FLOW
BEING PREDOMINANT. SOME SHOWERS SHOULD OCCUR OVER THE MTNS WHERE
OROGRAPHICS INTERACT WITH PERIODS OF ENHANCED MOISTURE IN THE
FLOW.
FIRE WEATHER...
COLD FRONT TO SAG DOWN INTO SOUTHEAST WYOMING TODAY...BRINGING
HIGHER DEWPOINTS AND COOLER TEMPERATURES TO AT LEAST THOSE ZONES
EAST OF THE LARAMIE RANGE. GOING TO SEE AN INCREASE IN CLOUDS AND
MOISTURE FRIDAY AS A STRONG PACIFIC STORM SYSTEM TRACKS THROUGH
NORTHERN COLORADO INTO THE PANHANDLE...BRINGING A VERY GOOD CHANCE
OF WETTING VALLEY RAINS AND MOUNTAIN SNOWS. VERY STRONG WINDS
BEHIND THE LOW FRIDAY NIGHT INTO SATURDAY AS THE LOW TRACKS INTO
THE PANHANDLE. WINDS TO CONTINUE INTO SUNDAY BEFORE EASING.
ANOTHER WIND EVENT IN THE OFFING MONDAY AFTERNOON AND PERSISTING
INTO WEDNESDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM 6 PM FRIDAY TO 6 PM SATURDAY FOR WYZ112-
WYZ114.
HIGH WIND WATCH FROM 6 PM FRIDAY TO 6 AM SATURDAY FOR WYZ104-
WYZ105-WYZ106-WYZ109-WYZ110-WYZ111-WYZ115-WYZ116.
NE...NONE.
&&
$$
UPDATE...FINCH
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
128 AM EDT SAT OCT 13 2012
.SYNOPSIS...
STRONG HIGH PRESSURE WILL BUILD OVER THE REGION FROM THE NORTH
THROUGH THIS WEEKEND. A WEAK COLD FRONT WILL MOVE ACROSS THE
AREA EARLY NEXT WEEK...FOLLOWED BY WEAK HIGH PRESSURE THROUGH
MID WEEK. A COLD FRONT IS EXPECTED TO APPROACH THE EAST COAST
LATE NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
BAND OF HIGH CLOUDS EXTENDING FROM TENNESSEE INTO SOUTHERN SOUTH
CAROLINA CORRELATE WELL WITH THE LATEST RAP 300MB MOISTURE FIELDS.
RAP SHOWS THE CIRRUS STEADILY THINNING WITH TIME AND CURRENT GOES-
EAST IR CHANNELS SUGGEST THIS IS ALREADY IN PROGRESS. MADE SOME
ADJUSTMENTS TO SKY COVER TO TAKE CURRENT TRENDS INTO ACCOUNT. ALSO
INCREASED WINDS ACROSS THE COASTAL AREAS AS WINDS ARE EXPECTED TO
INCREASE RATHER RAPIDLY OVER THE NEXT FEW HOURS AS THE PRESSURE
GRADIENT TIGHTENS. TEMPERATURES LOOK ON TRACK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
HIGH PRESSURE WILL RIDGE DOWN THE EAST COAST THROUGH THE PERIOD. A
COLD FRONT WILL APPROACH FROM THE WEST SUNDAY NIGHT. THE NET RESULT
OF THESE FEATURES WILL BE FAIR WEATHER THROUGH THE PERIOD...THOUGH
THERE MAY BE AN INCREASE IN CLOUDINESS AHEAD OF THE FRONT SUNDAY
NIGHT. THERE IS ALSO AN OUTSIDE SHOT AT A SHOWER OR THUNDERSTORM
LATE BUT THE PROBABILITY OF THAT IS LOW ENOUGH THAT IT WILL NOT BE
INCLUDED IN THE FORECAST AT THIS TIME. MAX TEMPERATURES SATURDAY
WILL GENERALLY FALL BETWEEN 75 AND 80 AND BE TWO OR THREE DEGREES
WARMER SUNDAY. MINS SATURDAY NIGHT WILL MAINLY BE IN THE LOWER TO
MIDDLE 50S. AND MODERATE TO THE UPPER 50S TO MIDDLE 60S SUNDAY
NIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE COLD FRONT WILL RAPIDLY SHIFT OFFSHORE MONDAY AND MONDAY
NIGHT...WITH WEAK HIGH PRESSURE BUILDING IN ITS WAKE TUESDAY THROUGH
WEDNESDAY. WILL KEEP RAIN CHANCES BELOW 15 PERCENT OVER LAND AREAS
TUESDAY AND WEDNESDAY ACCORDINGLY. ANOTHER COLD FRONT IS THEN
EXPECTED TO APPROACH FROM THE WEST ON THURSDAY...AND COULD
RE-INTRODUCE RAIN CHANCES FOR THE LATE WEEK PERIOD. OVERALL...HIGH
TEMPERATURES WILL GENERALLY RANGE FROM THE UPPER 70S NORTHERN AREAS
TO THE LOW 80S SOUTH. OVERNIGHT LOWS TREND SLIGHTLY WARMER TO THE
UPPER 50S INLAND AND THE LOW/MID 60S ALONG THE COAST.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
VFR. GUSTY WINDS WILL IMPACT THE TERMINALS AFTER SUNRISE IN
RESPONSE TO A TIGHTENING PRESSURE GRADIENT. THERE ARE SMALL
PROBABILITIES FOR MARGINAL MVFR CIGS TONIGHT AT KSAV...BUT
PROBABILITIES ARE TOO LOW TO JUSTIFY A MENTION ATTM.
EXTENDED AVIATION OUTLOOK...BREEZY/GUSTY NORTHEAST/EAST WINDS ARE
EXPECTED SATURDAY WITH A STRONG WEDGE OF HIGH PRESSURE IN PLACE.
THERE WILL BE AN INCREASING RISK FOR SHOWERS AND MVFR CIGS/VSBYS
EARLY NEXT WEEK...AS LOW-LEVEL MOISTURE INCREASES AND A WEAK COLD
FRONT AFFECTS THE AREA.
&&
.MARINE...
STRONG NORTHEAST SURGE IS BEGINNING TO TAKE SHAPE ALONG THE NORTH
CAROLINA COAST WHERE WINDS ARE ALREADY 20-25 KT WITH GUSTS TO 30
KT. RAP/H3R AS WELL AS THE LATEST MARINE TABULAR GUIDANCE ALL
SUPPORT WINDS INCREASING TO 20-25 KT WITH GUSTS TO 30 KT ACROSS
THE SOUTH CAROLINA MARINE ZONES OVER THE NEXT FEW HOURS AS THE
PRESSURE GRADIENT TIGHTENS IN RESPONSE TO HIGH PRESSURE WEDGING
DOWN THE CAROLINA PIEDMONT. THE STRONGEST SURGE WILL LIKELY WAIT
UNTIL AFTER SUNRISE TO REACH THE GEORGIA MARINE ZONES. SEAS WILL
BUILD QUICKLY IN THE NORTHEAST FLOW REGIME...LIKELY REACHING 4-6
FT OFF THE SOUTH CAROLINA COAST BY SUNRISE. SMALL CRAFT ADVISORIES
REMAIN IN FORCE FOR ALL MARINE LEGS.
SATURDAY THROUGH TUESDAY...STRONG HIGH PRESSURE WILL BUILD NORTH
OF THE AREA SATURDAY...BEFORE WEAKENING AND SHIFTING OFFSHORE
SUNDAY. A WEAK COASTAL TROUGH OF LOW PRESSURE COULD SET UP SUNDAY
BEFORE A COLD FRONT PUSHES THROUGH THE WATERS MONDAY INTO TUESDAY.
WILL CONTINUE THE ONGOING SMALL CRAFT ADVISORIES FOR ALL WATERS TO
ACCOUNT FOR MODERATE TO STRONG NORTHEAST FLOW AND BUILDING SEAS.
CONDITIONS ARE EXPECTED TO DIMINISH BY LATE SATURDAY FOR THE
NEARSHORE WATERS...HOWEVER LINGERING 6 FT SEAS WITHIN AN IDEAL FETCH
WILL MAINTAIN A SMALL CRAFT ADVISORY FOR THE OUTER GEORGIA WATERS
THROUGH AT LEAST MONDAY.
RIP CURRENTS...STRONG NE WINDS AND THE APPROACHING PERIGEAN SPRING
TIDE WILL CONTRIBUTE TO A MODERATE RISK FOR RIP CURRENTS ON ALL
BEACHES SATURDAY.
&&
.TIDES/COASTAL FLOODING...
TIDE LEVELS WILL BE ELEVATED THIS WEEKEND INTO THE MIDDLE OF NEXT
WEEK MAINLY DUE TO THE PERIGEAN SPRING TIDE. THERE IS A GOOD
CHANCE THAT TIDES WILL BE HIGH ENOUGH TO PRODUCE SOME INUNDATION
OF SALTWATER IN NORMALLY PRONE AREAS STARTING SUNDAY MORNING.
COASTAL FLOOD ADVISORIES WILL LIKELY BE NEEDED AT LEAST AROUND THE
TIMES OF THE MORNING HIGH TIDE EACH DAY THROUGH THE MIDDLE OF NEXT
WEEK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR AMZ330-350-
352-354.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT MONDAY NIGHT FOR
AMZ374.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1212 AM EDT SAT OCT 13 2012
.SYNOPSIS...
STRONG HIGH PRESSURE WILL BUILD OVER THE REGION FROM THE NORTH
THROUGH THIS WEEKEND. A WEAK COLD FRONT WILL MOVE ACROSS THE
AREA EARLY NEXT WEEK...FOLLOWED BY WEAK HIGH PRESSURE THROUGH
MID WEEK. A COLD FRONT IS EXPECTED TO APPROACH THE EAST COAST
LATE NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
BAND OF HIGH CLOUDS EXTENDING FROM TENNESSEE INTO SOUTHERN SOUTH
CAROLINA CORRELATE WELL WITH THE LATEST RAP 300MB MOISTURE FIELDS.
RAP SHOWS THE CIRRUS STEADILY THINNING WITH TIME AND CURRENT GOES-
EAST IR CHANNELS SUGGEST THIS IS ALREADY IN PROGRESS. MADE SOME
ADJUSTMENTS TO SKY COVER TO TAKE CURRENT TRENDS INTO ACCOUNT. ALSO
INCREASED WINDS ACROSS THE COASTAL AREAS AS WINDS ARE EXPECTED TO
INCREASE RATHER RAPIDLY OVER THE NEXT FEW HOURS AS THE PRESSURE
GRADIENT TIGHTENS. TEMPERATURES LOOK ON TRACK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
HIGH PRESSURE WILL RIDGE DOWN THE EAST COAST THROUGH THE PERIOD. A
COLD FRONT WILL APPROACH FROM THE WEST SUNDAY NIGHT. THE NET RESULT
OF THESE FEATURES WILL BE FAIR WEATHER THROUGH THE PERIOD...THOUGH
THERE MAY BE AN INCREASE IN CLOUDINESS AHEAD OF THE FRONT SUNDAY
NIGHT. THERE IS ALSO AN OUTSIDE SHOT AT A SHOWER OR THUNDERSTORM
LATE BUT THE PROBABILITY OF THAT IS LOW ENOUGH THAT IT WILL NOT BE
INCLUDED IN THE FORECAST AT THIS TIME. MAX TEMPERATURES SATURDAY
WILL GENERALLY FALL BETWEEN 75 AND 80 AND BE TWO OR THREE DEGREES
WARMER SUNDAY. MINS SATURDAY NIGHT WILL MAINLY BE IN THE LOWER TO
MIDDLE 50S. AND MODERATE TO THE UPPER 50S TO MIDDLE 60S SUNDAY
NIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE COLD FRONT WILL RAPIDLY SHIFT OFFSHORE MONDAY AND MONDAY
NIGHT...WITH WEAK HIGH PRESSURE BUILDING IN ITS WAKE TUESDAY THROUGH
WEDNESDAY. WILL KEEP RAIN CHANCES BELOW 15 PERCENT OVER LAND AREAS
TUESDAY AND WEDNESDAY ACCORDINGLY. ANOTHER COLD FRONT IS THEN
EXPECTED TO APPROACH FROM THE WEST ON THURSDAY...AND COULD
RE-INTRODUCE RAIN CHANCES FOR THE LATE WEEK PERIOD. OVERALL...HIGH
TEMPERATURES WILL GENERALLY RANGE FROM THE UPPER 70S NORTHERN AREAS
TO THE LOW 80S SOUTH. OVERNIGHT LOWS TREND SLIGHTLY WARMER TO THE
UPPER 50S INLAND AND THE LOW/MID 60S ALONG THE COAST.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
VFR LIKELY THROUGH SATURDAY. HOWEVER...LOW LEVEL MOISTURE DEPICTED
BY MODEL SOUNDINGS SUGGESTS SOME POTENTIAL FOR OCCASIONAL MVFR
CEILINGS SATURDAY. STRONG HIGH PRESSURE CENTERED N/NE OF THE
TERMINALS WILL SUPPORT E/NE WINDS WITH GUSTS AROUND 20 KT
SATURDAY.
EXTENDED AVIATION OUTLOOK...BREEZY/GUSTY NORTHEAST/EAST WINDS ARE
EXPECTED SATURDAY WITH A STRONG WEDGE OF HIGH PRESSURE IN PLACE.
THERE WILL BE AN INCREASING RISK FOR SHOWERS AND MVFR CIGS/VSBYS
EARLY NEXT WEEK...AS LOW-LEVEL MOISTURE INCREASES AND A WEAK COLD
FRONT AFFECTS THE AREA.
&&
.MARINE...
STRONG NORTHEAST SURGE IS BEGINNING TO TAKE SHAPE ALONG THE NORTH
CAROLINA COAST WHERE WINDS ARE ALREADY 20-25 KT WITH GUSTS TO 30
KT. RAP/H3R AS WELL AS THE LATEST MARINE TABULAR GUIDANCE ALL
SUPPORT WINDS INCREASING TO 20-25 KT WITH GUSTS TO 30 KT ACROSS
THE SOUTH CAROLINA MARINE ZONES OVER THE NEXT FEW HOURS AS THE
PRESSURE GRADIENT TIGHTENS IN RESPONSE TO HIGH PRESSURE WEDGING
DOWN THE CAROLINA PIEDMONT. THE STRONGEST SURGE WILL LIKELY WAIT
UNTIL AFTER SUNRISE TO REACH THE GEORGIA MARINE ZONES. SEAS WILL
BUILD QUICKLY IN THE NORTHEAST FLOW REGIME...LIKELY REACHING 4-6
FT OFF THE SOUTH CAROLINA COAST BY SUNRISE. SMALL CRAFT ADVISORIES
REMAIN IN FORCE FOR ALL MARINE LEGS.
SATURDAY THROUGH TUESDAY...STRONG HIGH PRESSURE WILL BUILD NORTH
OF THE AREA SATURDAY...BEFORE WEAKENING AND SHIFTING OFFSHORE
SUNDAY. A WEAK COASTAL TROUGH OF LOW PRESSURE COULD SET UP SUNDAY
BEFORE A COLD FRONT PUSHES THROUGH THE WATERS MONDAY INTO TUESDAY.
WILL CONTINUE THE ONGOING SMALL CRAFT ADVISORIES FOR ALL WATERS TO
ACCOUNT FOR MODERATE TO STRONG NORTHEAST FLOW AND BUILDING SEAS.
CONDITIONS ARE EXPECTED TO DIMINISH BY LATE SATURDAY FOR THE
NEARSHORE WATERS...HOWEVER LINGERING 6 FT SEAS WITHIN AN IDEAL FETCH
WILL MAINTAIN A SMALL CRAFT ADVISORY FOR THE OUTER GEORGIA WATERS
THROUGH AT LEAST MONDAY.
RIP CURRENTS...STRONG NE WINDS AND THE APPROACHING PERIGEAN SPRING
TIDE WILL CONTRIBUTE TO A MODERATE RISK FOR RIP CURRENTS ON ALL
BEACHES SATURDAY.
&&
.TIDES/COASTAL FLOODING...
TIDE LEVELS WILL BE ELEVATED THIS WEEKEND INTO THE MIDDLE OF NEXT
WEEK MAINLY DUE TO THE PERIGEAN SPRING TIDE. THERE IS A GOOD
CHANCE THAT TIDES WILL BE HIGH ENOUGH TO PRODUCE SOME INUNDATION
OF SALTWATER IN NORMALLY PRONE AREAS STARTING SUNDAY MORNING.
COASTAL FLOOD ADVISORIES WILL LIKELY BE NEEDED AT LEAST AROUND THE
TIMES OF THE MORNING HIGH TIDE EACH DAY THROUGH THE MIDDLE OF NEXT
WEEK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR AMZ330-350-
352-354.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT MONDAY NIGHT FOR
AMZ374.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS LINCOLN IL
327 AM CDT SAT OCT 13 2012
.DISCUSSION...
ISSUED 327 AM CDT SAT OCT 13 2012
SHORT TERM...TODAY THROUGH SUNDAY
MAIN CONCERNS THIS FORECAST PERIOD WILL BE ANTICIPATED CONVECTION
AND ANY ASSOCIATED STRONG/SEVERE STORMS AND HEAVY RAINFALL.
ELEVATED CONVECTION WAS ONGOING IN NORTHERN IL...AS WELL AS
NORTHERN AND CENTRAL MO. THIS WAS ASSOCIATED WITH LOWER LEVEL WARM
AIR ADVECTION/ISENTROPIC LIFT. THE GFS 300K SURFACE INDICATED THAT
THIS WILL CONTINUE THROUGH MUCH OF THE MORNING IN NORTHERN AND
CENTRAL IL. THE HRRR MODEL CONCURS THAT PERIODS OF SHOWERS AND
T-STORMS CAN BE EXPECTED THIS MORNING... ESPECIALLY ALONG AND
NORTH OF A TAYLORVILLE- DANVILLE LINE.
HIGH TEMPERATURES...AND PARTICULARLY SFC BASED INSTABILITY...WILL BE
CHALLENGING BECAUSE OF CONVECTIVE DEBRIS AS WELL AS PLENTY OF LOW
LEVEL MOISTURE AND AN INVERSION ON FORECAST SOUNDINGS UNTIL LATE
THIS AFTERNOON IN CENTRAL IL. WILL KNOCK DOWN HIGH TEMPS IN CENTRAL
IL AS A RESULT...BUT KEEP WARMER READINGS IN THE SOUTHEAST.
DESPITE MARGINAL INSTABILITY IN MOST AREAS THIS EVENING...INCREASING
UPPER LEVEL DIVERGENCE AHEAD OF AN UPPER LOW IN NORTHEAST KS ALONG
WITH 30-40KTS OF BULK SHEAR WILL RESULT IN A DEVELOPING LINE OF
STORMS APPROACHING WEST CENTRAL IL LATE THIS EVENING.
UNIDIRECTIONAL FLOW ALOFT AND INCREASING LOW LEVEL WINDS BELOW
850 MB COULD RESULT IN GUSTY WINDS WITH THE STRONGEST STORMS.
WITH EACH SUCCESSIVE MODEL RUN A BIT SLOWER...AM NOT EXPECTING THE
T-STORMS TO REACH EXTREME EAST AND SOUTHEAST IL UNTIL VERY LATE
TONIGHT. EXPECT SHOWERS AND ISOLATED T-STORMS TO LINGER IN
CENTRAL IL MUCH OF THE DAY SUNDAY AHEAD OF THE UPPER LEVEL TROUGH
AXIS...BEFORE DEPARTING THE STATE LATE SUNDAY NIGHT.
LONG TERM...MONDAY THROUGH FRIDAY
A SEMI-ZONAL FLOW WILL DEVELOP AFTER THE UPPER LEVEL TROF
DEAMPLIFIES AND LIFTS THROUGH THE NEW ENGLAND STATES LATER MONDAY
AND TUESDAY. THIS WILL RESULT IN TEMPERATURES CLOSE TO SEASONAL
NORMALS FOR MID-OCTOBER.
THE NEXT CHANCE FOR PRECIPTIATION IS EXPECTED LATE TUESDAY
NIGHT...BUT PARTICULARLY WEDNESDAY AS AN UPPER LEVEL TROUGH FROM
THE PACIFIC NORTHWEST CROSSES INTO THE NORTHERN PLAINS AND DEEPENS
IN THE UPPER MIDWEST. THERE IS CONSIDERABLE MODEL UNCERTAINTY AT
THIS POINT WITH THE SPEED OF THE SYSTEM AND JUST HOW FAR SOUTH THE
UPPER LEVEL LOW WILL DEVELOP AND HOW STRONG IT WILL BE. FOR NOW
WILL GO WITH SHOWERS AND A FEW T-STORMS AHEAD OF THE SURFACE COLD
FRONT WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY SOMEWHAT COOLER
TEMPERATURES IN THE LOWER TO MIDDLE 60S.
WILL NEED TO KEEP AN EYE ON THIS SYSTEM BECAUSE IF THE UPPER LOW
SETTLES OVER THE MIDWEST THEN TEMPERATURES WILL BE QUITE CHILLY
WITH RAINY CONDITIONS FOR FRIDAY AND BEYOND.
MILLER
&&
.AVIATION...
ISSUED 1150 PM CDT FRI OCT 12 2012...FOR THE 06Z TAFS
AN INITIAL LINE OF SHOWERS AND STORMS WILL PRIMARILY PASS JUST TO
THE NORTHWEST OF PIA...BUT THE SOUTHERN EDGE OF THE LINE MAY COME
CLOSE TO THE PIA AIRPORT. WE WILL CONTINUE WITH VCSH INSTEAD OF
VCTS AS WE DO NOT EXPECT LIGHTNING AT THE AIRPORT. THE NEAREST
STORM CELL IS PROJECTED TO PASS WELL TO THE NORTH OF PIA. MVFR
CLOUD HEIGHTS WILL BE POSSIBLE FOR PIA/BMI/SPI OVERNIGHT.
THE NEXT WAVE OF STORMS FARTHER TO THE SOUTHWEST ARE PROJECTED TO
ARRIVE AFTER SUNRISE ON SATURDAY...AND EXPAND TO COVER AREAS
CLOSER TO THE REMAINING TAF SITES. WE WILL INCLUDE SOME VCSH FOR
THE DAYTIME HOURS...BEGINNING 14Z AT PIA/SPI AND PROGRESSING TO
18Z AT CMI/DEC. SOME MVFR CLOUDS MAY OCCUR DURING THE MORNING AS
MOISTURES LEVELS INCREASE NEAR THE SURFACE. WE CANT RULE OUT A
BRIEF PERIOD OF IFR AS WELL...BUT WILL NOT INCLUDE THAT LOW AT
THIS POINT.
THE BEST CHANCES FOR STRONGER STORMS WILL STILL BE LATE EVENING
NEAR PIA...AND FOR AFTER MIDNIGHT SAT NIGHT FOR THE REMAINING TAF
SITES...WHICH IS BEYOND THIS TAF PERIOD.
WILL INCLUDE A BREAK IN THE RAIN CHANCES FOR MOST OF SATURDAY EVENING
FOR THE TAFS.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
338 AM CDT SAT OCT 13 2012
.SHORT TERM /TODAY/...
MAIN CONCERN THIS MORNING IS OBVIOUSLY CONVECTIVE TRENDS. LONG WAVE
TROUGH CONTINUES TO MOVE ACROSS THE ROCKIES WITH ASSOCIATED WARM
FRONT FROM WY/SD SURFACE LOW THROUGH MO VALLEY. RAP ANALYSIS
APPEARS TO BE HANDLING CURRENT WEATHER WELL SHOWING INTENSIFYING
THETA-E ADVECTION COINCIDENT WITH NARROW NW-SE MCS FROM NE INTO MO.
REMNANT MCS THAT FORMED NEAR PARENT UPPER LOW IN THE ROCKIES
CONTINUES TO ADVANCE ACROSS KS INTO NE...MERGING WITH WARM ADVECTION
CONVECTION. RAP 300-310K ISENT LAYER ROOTED AT TOP OF INVERSION
ADVANCES THIS MCS INTO IA AND MATURES IT THROUGH THE MORNING WITH
STRONG MOISTURE TRANSPORT. ELEVATED CAPES APPEAR TO BE AROUND 1000
J/KG WITH MARGINAL EFFECTIVE SHEAR UPSTREAM INTO IMMEDIATE MO RIVER
VALLEY. HOWEVER ESTIMATED RAP EFFECTIVE SHEAR /1-6KM/ WANES SO
REALLY DO NOT EXPECT MUCH IN THE WAY OF SEVERE WEATHER THIS
MORNING...JUST MUCH NEEDED RAIN. THE LATEST HRRR SUPPORTS THIS AS
WELL AND SEEMS TO BE CLOSER TO REALITY...UNLIKE MOST WRF RUNS...SO
WIDESPREAD CATEGORICAL POPS HAVE BEEN INCLUDED.
QUESTION BY THIS AFTERNOON TURNS TO SEVERE WEATHER POTENTIAL ALONG
WITH LESS CONFIDENCE. 60F PLUS DEWPOINTS CURRENTLY NOTED SOUTH OF
WARM FRONT ACROSS KS SHOULD ENTER IA BY THIS AFTERNOON RESULTING IN
MAX MLCAPES AROUND 1500 J/KG AND LITTLE CINH. THIS THERMODYNAMIC
ENVIRONMENT WOULD BE COINCIDENT WITH FAVORABLE DEEP SHEAR FOR
SUPERCELLS AND SHALLOW SHEAR FOR A FEW TORNADOES...ESPECIALLY S
CENTRAL/SE LATE. AGREE WITH SPC LOW TOR PROBS SOUTH BECAUSE OF
THIS...BUT UNIDIRECTIONAL S/SWLY FLOW IS NOT TOO CONDUCIVE.
HOWEVER ANOTHER QUESTION WILL BE INITIATION OR SOURCE. FRONTAL
SYSTEM AND CONVERGENCE WILL LAG THIS AREA CONSIDERABLY...STILL BACK
INTO KS/NE/NWRN IA BY 00Z...AS IS STRONGER H7/H5 FORCING IMMEDIATELY
AHEAD OF PARENT LOW. MINOR WAVES AND H85/H7 FORCING EJECTING OUT IN
SWLY UPPER FLOW COULD FORM ANOTHER MCS...OR REMNANTS FROM SRN TAIL
END OF CURRENT KS CONVECTION COULD EVENTUALLY REACH IA. HOWEVER
THIS DEVELOPMENTAL UNCERTAINTY...AND THE POTENTIAL THAT MORNING MCS
COULD HINDER THE THERMODYNAMIC ENVIRONMENT...HAS MADE THIS SEVERE
WEATHER CONDITIONAL AND LESS CERTAIN. MANY MODELS STILL DEVELOP
SOMETHING FROM THE SOUTH INTO SRN IA HOWEVER SO ALTHOUGH DETAILS NOT
CLEAR...HAVE INTRODUCED SEVERE WORDING SOUTH.
REGARDLESS OF PRECIP TRENDS...AIRMASS SHOULD FEEL SUMMERLIKE WITH
MODEL CONSENSUS PUSHING HIGHS INTO THE 70S AND DEWPOINTS INTO THE
60S. RAW MODEL TEMPS AND MOS GUIDANCE ALL SEEM TO BE IN AGREEMENT
ON THIS.
.LONG TERM /TONIGHT THRU FRIDAY/...
MODELS HAVE COME TOGETHER FOR THE MOST PART WITH THE TIMING AND
EVOLUTION OF THE LOW THIS EVENING. SURFACE LOW WILL TRACK ACROSS
IOWA...MOST LIKELY THE SOUTH HALF...THIS EVENING AND KEPT A SHORT
WINDOW FOR POTENTIAL SEVERE. THAT WILL BE OUT OF THE PICTURE BY
03Z. CHANGE IN THE EVOLUTION FROM PREVIOUS RUNS IS THE TRACK A BIT
FARTHER SOUTH...RESULTING IN A DECENT DEFORMATION ZONE CROSSING IOWA
TONIGHT AND LINGERING WELL IN TO SUNDAY MORNING. MADE ADJUSTMENTS
TO COVER THAT BOTH WITH INCREASING POPS AS WELL AS LOWERING MAX
TEMPS FOR SUN. THE NEXT WEATHER SYSTEM IS SLATED TO ARRIVE MID
WEEK. A BIG DIFFERENCE BETWEEN THE GEM AND ECMWF SOLUTIONS AND THE
GFS WITH THE DEEPENING OF THE UPPER LOW. GEM AND EC BOTH SUGGEST
COOLER AND WETTER WEATHER IS IN STORE. CURRENTLY...PRECIP IS IN FOR
THE WED TIME FRAME. KEPT IT IN THE NERN ZONES FOR THE LATER PART OF
THE WEEK...BUT MAY HAVE TO BE ADJUSTED FARTHER SOUTH AND WEST WITH
LATER PACKAGES. WITH THE SYSTEM DURING MID WEEK BEING FROM THE
NORTHERN STREAM INSTEAD OF THE SOUTHERN BRANCH...DON`T SEE THE
THUNDER THREAT AS BEING A BIG DEAL.
&&
.AVIATION...13/06Z
SHOWERS AND POSSIBLE THUNDERSTORMS EXPECTED TO SPREAD ACROSS THE
STATE THROUGH 06Z TO 09Z AND CONTINUE INTO MID MORNING SATURDAY.
EXPECT A POSSIBLE BREAK IN THE PRECIP BY LATE MORNING INTO THE EARLY
AFTERNOON HOURS WITH SHOWERS AND THUNDERSTORMS EXPECTED TO REDEVELOP
BY MID TO LATE AFTERNOON AND CONTINUE THROUGH THE EVENING HOURS.
HIGH CONFIDENCE THAT THERE WILL BE THUNDER WITH BOTH WAVES OF
PRECIP...HOWEVER HIGH UNCERTAINTY IN TIMING AND PLACEMENT SO HAVE
LEFT MENTION OF THUNDER OUT OF THE TAFS AT THIS TIME. MAINLY MVFR
WITH POSSIBLE IFR CIGS EXPECTED THROUGHOUT THE PERIOD...AND COULD
SEE CIGS LIFT INTO LOW VFR DURING THE BREAKS IN THE PRECIP.
SOUTHERLY WINDS EXPECTED THROUGH THE PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...MS OCT 12
AVIATION...BEERENDS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
422 AM CDT SAT OCT 13 2012
.DISCUSSION...
WATER VAPOR IMAGERY SHOWING CENTER OF THE UPPER LOW JUST NORTH OF
THE FOUR CORNERS MOVING EASTWARD AS ANOTHER STRONG SHORTWAVE TROUGH
SWINGS EAST SOUTHEASTWARD AROUND THE SOUTHERN PORTIONS OF THE
TROUGH. CONVECTION HAS CONTINUED TO DEVELOP THROUGH THE NIGHT AHEAD
OF THE MAIN TROUGH THROUGH THE CENTRAL AND SOUTHERN HIGH PLAINS AS
IT MARCHES NORTHEASTWARD AND SLOWLY WEAKENS. MANY OF THE MODELS
ARE NOT HANDLING THIS EXPANSIVE AREA OF CONVECTION AND ITS
MOVEMENT..ALTHOUGH THE RAP IS DOING THE BEST AND INITIALLY HAVE
LEANED WITH ITS GRADUAL EASTWARD MOTION THROUGH THE MORNING WITH
ADDITIONAL DEVELOPMENT OUT AHEAD OF THIS INITIAL CONVECTION ACROSS
MUCH OF THE CENTRAL PORTIONS OF THE CWA THIS MORNING. RECENT RADAR
LOOPS ARE CONFIRMING MORE ELEVATED CONVECTION OUT AHEAD OF THE
LINE AND SOUTHWARD INTO OK. ALSO...NAM AND RECENTLY THE NEW EC
SUGGEST A SLOWER...DEEPER AND FURTHER SOUTH TRACK TO THE UPPER
TROUGH AS IT PROGRESSES ACROSS THE CWA LATE TODAY AND TONIGHT.
THIS COULD RESULT IN A MORE BACKED UPPER FLOW TODAY AND DELAY THE
EASTWARD PROGRESSION OF THIS MORNINGS CONVECTION AND MIDDAY
INSOLATION. ALL IN ALL...THIS COULD CREATE A CHALLENGE IN
FORECASTING THE DEGREE OF INSTABILITY AND RESULTING DEGREE OF THE
SEVERE THUNDERSTORM POTENTIAL ACROSS THE CWA THIS AFTERNOON INTO
THE EVENING. EITHER WAY...ELEVATED SHOWERS AND THUNDERSTORMS WILL
BE PREVALENT THIS MORNING WITH AN "EXPECTED" BREAK IN CONVECTION
BY MIDDAY FOLLOWED BY ADDITIONAL STRONGER DEVELOPMENT AHEAD OF THE
FRONT AND WITHIN INCREASING LARGE SCALE ASCENT AS A JET MAX ROUNDS
THE BASE OF THE UPPER TROUGH AS IT MOVES OUT INTO THE CENTRAL
PLAINS. WITH THE VERY STRONG SHEAR AND CAPE...ANY SUSTAINED
DISCRETE STORMS THAT ARE ABLE TO FORM THIS AFTERNOON MAY BE
CAPABLE OF PRODUCING LARGE HAIL...STRONG WINDS AND POSSIBLY AN
ISOLATED TORNADO PRIMARILY ACROSS NORTHEAST AND EAST CENTRAL AREAS.
HOWEVER...WITH THE ORIENTATION OF LARGE SCALE FORCING AND A MORE
PREDOMINANT UNIDIRECTIONAL FLOW...WOULD EXPECT STORMS TO FORM A
LINE OR LINE SEGMENTS WITH THE MAIN SEVERE POTENTIAL BEING VERY
STRONG STRAIGHTLINE WINDS. AGAIN...DEGREE OF INSTABILITY MAY BE
AFFECTED BY PRECIP COVERAGE AND CLOUDCOVER. WITH INCREASING
PRECIPITABLE WATER VALUES APPROACHING AN INCH AND THREE
QUARTERS...LOCALLY HEAVY RAINFALL CAN ALSO BE EXPECTED IN SOME
AREAS. WITH THE SLOWER AND MORE SOUTHWARD TRACK OF THE
TROUGH...HAVE EXTENDED HIGHER POPS BEYOND MIDNIGHT TONIGHT...BUT
STILL ENDED BY SUNRISE ON SUNDAY. LOWERED HIGH TEMPS SLIGHTLY
TODAY THROUGH THE LOWER AND MIDDLE 70S AND AGAIN ON
SUNDAY...ESPECIALLY IN THE FAR EAST.
HAVE MAINTAINED A DRY FCST SUNDAY THROUGH TUESDAY WITH HIGHS IN THE
70S...THEN KEPT THE BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS
CENTERED ON WEDNESDAY AS THE NEXT COLD FRONT AND UPPER TROUGH MOVES
THROUGH THE NORTHERN PLAINS AND MIDWEST. WILL KEEP HIGHS BEHIND THE
FRONT IN THE 60S FOR THURSDAY AND FRIDAY...BUT STILL DRY AS MAIN
TROUGH SETS UP TO THE EAST IN THE MS AND OH RIVER VALLEYS. 63
&&
.AVIATION...
SCATTERED THUNDERSTORMS WILL CONTINUE ON AND OFF THROUGH 09Z
BEFORE BECOMING MORE WIDESPREAD WITH SHOWERS AND THUNDERSTORMS
THROUGH 15Z. ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED AFTER 19Z
AT MHK AND AFTER 21Z AT TOP AND FOE. BY 04Z MOST IF NOT ALL OF THE
CONVECTION SHOULD MOVE EAST OF THE TERMINALS. IFR TO MVFR CIGS AND
VSBYS EXPECTED TO CONTINUE THROUGH MUCH OF THE PERIOD.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
321 AM CDT SAT OCT 13 2012
.DISCUSSION...
TODAY AND TONIGHT:
ONGOING CONVECTION ACROSS WESTERN KANSAS IS MAKING THE CONVECTIVE
FORECAST FOR LATER TODAY A LITTLE MURKY. SYNOPTIC MODELS DID NOT
HANDLE CONVECTION EVOLUTION DURING THE OVERNIGHT HOURS VERY
WELL...WITH MESO-SCALE MODELS PERFORMING ONLY SLIGHTLY BETTER.
RUC13 APPEARS TO HAVE THE BEST HANDLE ON CONVECTIVE EVOLUTION IN
THE VERY SHORT TERM...THUS WILL USE IT AS A GUIDE AT LEAST THROUGH
THE MORNING HOURS.
AFTER MORNING CONVECTION MOVES EAST OF THE CWA...EXPECT A BRIEF
LULL IN ACTIVITY DUE TO SUBSIDENCE BEHIND MORNING
CONVECTION...BEFORE STORMS RE-FIRE BY EARLY TO MID-AFTERNOON.
TIMING OF WHEN STORMS WILL RE-FIRE AND EXACTLY WHERE STILL IS
UNCLEAR...BUT JUXTAPOSITION OF BEST KINEMATICS AND INSTABILITY
SUGGEST INITIATION SHOULD OCCUR IN THE SOUTHWEST CORNER OF CWA.
FORECAST SOUNDINGS NOT DEPICTING LARGE CAPE VALUES...WITH LARGE
SCALE MOISTURE FLUX LIMITING AMOUNT OF MID-LEVEL DRYING. LARGE
SCALE KINEMATICS SUGGEST CONVECTION WILL BE MAINLY LINEAR IN
NATURE...HOWEVER NAM AND RUC HINT AT A DEVELOPMENT OF MESOLOW
ALONG OR JUST NORTH OF OK-KS BORDER...WHICH COULD INCREASE LOW
LEVEL HELICITY ENOUGH TO ALLOW ISOLATED SUPERCELL TO DEVELOP. FEEL
ANY ISOLATED STORM THAT DEVELOPS WILL NOT LAST TOO LONG...WITH
QLCS BEING THE DOMINATE CONVECTION MODE. BEST POTENTIAL FOR SEVERE
CONVECTION WILL BE DURING THE AFTERNOON INTO EARLY EVENING
HOURS...WITH BULK OF CONVECTION EXITING THE CWA BY MIDNIGHT.
SUN-MON:
LARGE SCALE SUBSIDENCE BEHIND DEPARTING UPPER SYSTEM WILL ALLOW
SKIES TO CLEAR QUICKLY AT LEAST MID-MORNING SUNDAY. WEAK COLD AIR
ADVECTION BEHIND SURFACE COLD FRONT WILL KEEP TEMPERATURES
SLIGHTLY COOLER FOR SUNDAY...ESPECIALLY ACROSS EASTERN PART OF THE
CWA. TEMPERATURES WILL REBOUND ON MONDAY WITH WEAK DOWNSLOPE
WARMING. DRY CONDITIONS ARE EXPECTED.
TUE-THU:
BULK OF THE LONGER RANGE PORTION OF THE FORECAST APPEARS
QUIET. GEFS AND LONGER RANGE OPERATIONAL MODELS SHOWING SOME
DIFFLUENCE IN THE WED-THU TIME FRAME IN THE TIMING OF SHORT WAVE
FEATURE MOVING OUT OF WESTERN CANADA. APPEARS AREA WILL EXPERIENCE
THE PASSAGE OF ANOTHER COLD FRONT BY MID-WEEK...HOWEVER
PRECIPITATION CHANCES IN QUESTION. GULF WILL REMAIN SOMEWHAT
BLOCKED...SO ANY PRECIPITATION WILL BE CONCENTRATED IN PROXIMITY
OF UPPER DYNAMICS...WHICH SHOULD BE FOCUSED NORTH AND EAST OF
FORECAST AREA. HOWEVER...THERMODYNAMIC FORCING MAY ALLOW SCATTERED
CONVECTION TO DEVELOP ALONG FRONT...SO WILL MAINTAIN LOW CHANCE
POPS ACROSS MAINLY EASTERN CWA. TEMPERATURES SHOULD NO DEVIATE TOO
MUCH FROM NORMALS...THUS ACCEPTED GUIDANCE AS A WHOLE.
SF
&&
.PREV DISCUSSION... /ISSUED 1156 PM CDT FRI OCT 12 2012/
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE ANTICIPATED UPPER LEVEL LOW IS STILL MAKING ITS WAY INTO THE
HIGH PLAINS...BUT LIFT ASSOCIATED WITH IT IS ALREADY FORMING A
NICE LINE OF STORMS IN WESTERN KANSAS. THE STORY FOR MOST SITES
HAS BEEN IFR CONDITIONS WITH OCCASIONAL MVFR AND/OR LIFR. LOW
VISBYS AND CIGS APPEAR TO BE ON A KINGMAN TO SALINA LINE EXTENDING
TO THE NORTHWEST. BASIC EXPECTED TRENDS ARE FOR BANDS OF SHOWERS
AND THUNDERSTORMS TO PASS OVER THE CENTRAL KANSAS SITES NEAR AND
JUST BEFORE SUNRISE...THEN MOVE SLOWLY TO THE NORTH AND EAST AS
THE SURFACE LOW DEEPENS IN THE LEE OF THE ROCKIES. THIS SURFACE
LOW WILL TIGHTEN UP A DRY LINE AND MOVE EAST...AND DEPENDING ON
THE CLEARING BETWEEN THE MORNING CLOUDS AND PRECIP AND THE DRY
LINE...SHOULD FIRE NEW STORMS LATER SATURDAY AFTERNOON. THE AREAL
EXTENT OF THESE STORMS CAN`T BE PINNED DOWN YET...BUT IS EXPECTED
TO AFFECT ALL SITES EXCEPT FOR CNU...WHICH WILL SEE THE EFFECTS OF
THESE STORMS LATER IN THE EVENING. -LAUGEMAN
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 78 52 77 49 / 70 30 0 0
HUTCHINSON 79 51 78 48 / 60 30 0 0
NEWTON 77 51 77 49 / 60 30 0 0
ELDORADO 76 51 77 49 / 70 40 0 0
WINFIELD-KWLD 78 52 78 50 / 70 40 0 0
RUSSELL 79 48 77 46 / 40 30 0 0
GREAT BEND 80 49 77 47 / 40 20 0 0
SALINA 80 50 77 49 / 60 30 10 0
MCPHERSON 79 50 77 48 / 60 30 0 0
COFFEYVILLE 78 56 79 51 / 80 70 10 0
CHANUTE 76 54 77 50 / 80 70 10 0
IOLA 76 54 76 50 / 80 70 10 0
PARSONS-KPPF 77 54 78 50 / 80 80 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1203 AM MDT SAT OCT 13 2012
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 1245 PM MDT FRI OCT 12 2012
LATEST THINKING IS THERE WILL BE TWO POTENTIAL ROUNDS OF
PRECIPITATION ASSOCIATED WITH THE LARGE UPPER LOW OVER SOUTHERN
NEVADA THAT WILL AFFECT THE REGION IN THE NEXT 18 HOURS. FIRST...A
SHORT WAVE TROUGH CURRENTLY LIFTING NORTHEAST ACROSS THE OKLAHOMA
PANHANDLE WILL INITIATE SHOWERS AND ISOLATED THUNDERSTORMS THIS
AFTERNOON FROM SOUTHWEST TO NORTHEAST BETWEEN ABOUT 20Z AND 01Z.
THE NAM SHOWS DECENT ELEVATED CAPE AROUND 1000 J/KG HOWEVER 0-6 KM
BULK SHEAR IS ONLY ABOUT 25 KTS THIS AFTERNOON. SUB-SEVERE HAIL
AND C-G LIGHTNING ARE THOUGHT TO BE THE MAIN THREATS. THIS FIRST
ROUND OF PRECIP SHOULD BEGIN TO WEAK AND LOSE COVERAGE AS THE
UPPER TROUGH LIFTS FURTHER NORTHEAST AFTER 00Z. ONE MODULATING
INFLUENCE THIS AFTERNOON IS POSITION OF 250 MB JET. THE CURRENT
LOCATION PUTS OUR AREA IN THE RIGHT EXIT REGION WHICH MAY EXPLAIN
THE LOOK OF THE HRRR REFLECTIVITY FIELDS LATER THIS AFTERNOON
WITH PRECIPITATION SPLITTING AND WEAKENING.
THE BULK OF THE SYSTEM IS EXPECTED TO APPROACH THE AREA OVERNIGHT...
BUT THINK BETTER CHANCES OF SHOWERS AND THUNDERSTORMS WILL BE IN
THE SOUTHEAST COUNTIES IN THE 06-12Z TIME FRAME. THE NAM SHOWS
SOME CAPE IN THE -10 TO -20 C HAIL GROWTH REGION AT THAT TIME,
PLUS 0-6 KM SHEAR WILL INCREASE TO AROUND 70 KTS INDICATING A FEW
STORMS OVERNIGHT HAVE THE POTENTIAL TO PRODUCE SEVERE HAIL IF
THINGS COME TOGETHER AS PLANNED. ALSO KEPT MENTION OF AREAS OF FOG
OVERNIGHT WITH LOW LEVEL RH VALUES ABOVE 95 PERCENT.
ON SATURDAY...SOMEWHAT LESS CERTAIN REGARDING POTENTIAL FOR
SCATTERED SHOWERS DURING THE AFTERNOON. LAPSE RATES NOT ALL THAT
STEEP AS UPPER SYSTEM MOVES OVERHEAD...AND SUBSIDENCE BEHIND UPPER
TROUGH WITH RIDGING MOVING IN WILL COINCIDE WITH PEAK HEATING. KEPT
SLIGHT CHANCES FOR SHOWERS GOING FOR NOW BUT CONFIDENCE IS NOT THAT
HIGH FOR DECENT COVERAGE IF LATEST NAM-GFS VERIFY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 240 PM MDT FRI OCT 12 2012
THE CLOSED LOW THAT BROUGHT PRECIP WILL EXIT THE AREA EARLY SATURDAY
EVENING. MODELS PLACE PRECIP WELL WEST OF THE LOW WHERE A SHORT
WAVE RIDGE WILL BE. AM THINKING IF ANY PRECIP WILL DEVELOP IT
WILL BE JUST BEHIND THE CLOSED LOW. AM NOT TOO CONFIDENT THERE
WILL BE ANY PRECIP ACCOMPANYING THE CLOSED LOW AS IT MOVES EAST
DUE TO 700-500MB LAPSE RATES LESS THAN 6C/KM. HOWEVER WITH MODELS
SHOWING PRECIP FOLLOWING THE CLOSED LOW...WILL KEEP THE MENTION OF
SLIGHT CHANCES GOING DURING THE EARLY EVENING AS THE LOW EXITS THE
AREA.
SUNDAY AND SUNDAY NIGHT AN UPPER LEVEL RIDGE WILL BUILD OVER THE
INTERMOUNTAIN WEST...EXTENDING OVER THE TRI-STATE AREA. A MINOR
SHORT WAVE TROUGH WILL MOVE THROUGH THE FLOW OVER THE NORTHEAST PART
OF THE AREA. HOWEVER WITH LITTLE MOISTURE TO WORK WITH...AM NOT
EXPECTING ANYTHING MORE THAN A FEW CLOUDS TO DEVELOP. BEHIND THE
SHORT WAVE TROUGH WINDS WILL INCREASE DURING THE AFTERNOON...WITH
GUSTS NEAR 30MPH AS STRONG WINDS ABOVE THE SURFACE MIX DOWN.
TEMPERATURES FOR SATURDAY THROUGH SUNDAY NIGHT WILL BE NEAR NORMAL.
FOR MONDAY THROUGH FRIDAY THE PERIOD WILL BE PRIMARILY DRY. TUESDAY
AND WEDNESDAY A SHORT WAVE TROUGH MOVES THROUGH THE FLOW OVER THE
AREA...WITH A COLD FRONT FOLLOWING THE FIRST SHORT WAVE TUESDAY
NIGHT. THERE IS SOME MOISTURE TO WORK WITH...SO HAVE INCLUDED
SLIGHT CHANCES FOR THE FAR NORTHEAST PART OF THE AREA TUESDAY
NIGHT. ANOTHER STRONGER COLD FRONT MOVES THROUGH WEDNESDAY NIGHT.
THERE IS LESS MODEL AGREEMENT WITH PRECIP DEVELOPING AS THE SECOND
COLD FRONT MOVES THROUGH...SO WILL CONTINUE WITH THE DRY FORECAST.
TEMPERATURES THROUGH THIS PERIOD WILL BE ABOVE NORMAL PRIOR TO THE
FIRST COLD FRONT THEN NEAR NORMAL THROUGH THE REST OF THE WEEK
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1111 PM MDT FRI OCT 12 2012
THE AREA OF SHOWERS HAS MOVED THROUGH THE MAJORITY OF THE
FORECAST AREA THIS EVENING WITH SHOWERS AND THUNDERSTORMS
EXTENDING FROM SOUTH CENTRAL NEBRASKA TO SOUTHWEST KANSAS. THE
MAIN UPPER LOW CENTER IS STILL OVER WESTERN COLORADO AT 06Z AND
WILL CONTINUE TO MOVE EAST OF THE ROCKIES OVERNIGHT WITH SHOWERS
AND THUNDERSTORMS MOVING OUT OF THE AREA AND SURFACE TROUGH AND
FRONTAL BOUNDARY MOVING ACROSS THE AREA BETWEEN 12Z-15Z THIS
MORNING. HAVE MENTIONED SHOWERS IN THE VICINITY OF KMCK AT THE
BEGINNING OF THE TAF PERIOD WITH A POSSIBILITY OF MVFR CONDITIONS
DUE TO LOWER CEILINGS...OTHERWISE CONDITIONS WILL CONTINUE TO BE
VFR. AS THE FRONT MOVES ACROSS THE TAF SITES EARLY THIS
MORNING...WINDS ARE EXPECTED TO TURN FROM THE SOUTH TO THE
NORTHWEST. WINDS WILL ALSO REMAIN GUSTY THROUGH THE DAY AS CLOUDS
THIN THROUGH THE DAY IN THE SUBSIDENT AREA ON THE BACK SIDE OF THE
EXITING LOW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DLF
LONG TERM...JTL
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
155 AM EDT SAT OCT 13 2012
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 406 PM EDT FRI OCT 12 2012
WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL NRN STREAM
MID/UPPER LEVEL FLOW ACROSS THE NRN CONUS INTO THE WRN GREAT LAKES.
A VIGOROUS SRN STREAM LOW WAS LOCATED OVER NW AZ. AT THE SFC...SRLY
WINDS WERE INCREASING FROM THE PLAINS INTO THE UPPER MS VALLEY BTWN
HIGH PRES OVER LOWER MI AND A TROUGH DEVELOPING OVER THE WRN PLAINS.
VIS LOOP SHOWED DIURNAL CLOUDS OVER CNTRL UPPER MI THINNING AND
SHIFTING TO THE EAST AS SW WINDS DEVELOP. ANY LEFTOVER LAKE EFFECT
PCPN OVER ERN LAKE SUPERIOR HAD DISSIPATED
AS THE SFC HIGH SHIFTS TOWARD THE MID ATLANTIC STATES AND THE
SHRTWV/SFC LOW LIFTS OUT OF THE CENTRAL ROCKIES INTO THE PLAINS...A
STRENGTHENING SW FLOW WILL DEVELOP OVER THE WESTERN GREAT LAKES
TONIGHT. WITH STRONG WAA AND MOISTURE ADVECTION DEVELOPING WITH
MODERATE TO STRONG 295K-305K ISENTROPIC LIFT...RAIN WILL QUICKLY
DEVELOP AND SPREAD TO THE NORTHWEST. HOWEVER...WITH CONVECTION
LIKELY TO DEVELOP CLOSER TO THE SFC-850 MB WARM FRONT...MOISTURE
ADVECTION INTO UPPER MI MAY BE REDUCED. SO...THE NAM/ECMWF WHICH
INDICATES A SLIGHTLY LATER ARRIVAL(BTWN 09Z-12Z)OF THE PCPN WITH THE
HEAVIER PCPN MAINLY SOUTH OF UPPER MI WAS PREFERRED. EXPECT THE
STRONGER ISENTROPIC LIFT TO DIMINISH AND SHIFT TO THE EAST
DURING THE AFTERNOON AS THE SFC-850 MB WARM FRONT MOVES INTO NRN
LAKE MI AND NRN LWR MI. LIKELY TO CATEGORICAL POPS ARE STILL
WARRANTED ACROSS MUCH OF THE FCST AREA EVEN FOR PCPN AMOUNTS LESS
THAN 0.10 NORTHWEST...0.10 TO 0.25 INCH CNTRL TO NEAR 0.50 INCH EAST
AND FAR SOUTH.
INCREASING CLOUDS AND WIND WILL LIMIT THE DIURNAL FALL OF TEMP...AND
FCST THERMAL PROFILES INDICATE ANY PCPN SHOULD BE IN THE FORM OF
RAIN EVEN THOUGH TEMPS AT SOME OF THE INTERIOR COLD SPOTS MIGHT FALL
AOB 32 EARLY THIS EVENING BEFORE THE THICKER CLOUDS ARRIVE. EVEN
WITH THE STRONG WAA...PCPN AND CLOUDS WILL LIMIT HIGHS TO THE MID
AND UPPER 40S SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 406 PM EDT FRI OCT 12 2012
MOST ATTENTION IN LONG TERM ON SAT NIGHT THROUGH SUN WITH A SYSTEM
THAT MAY BRING A COUPLE INCHES OF RAIN TO PARTS OF THE REGION. THERE
IS SOME UNCERTAINTY WITH THIS SYSTEM DUE TO MODEL DISAGREEMENT.
DIFFERENCES BETWEEN MODELS INITIALLY ARE DUE TO DIFFERENCES IN UPPER
LEVEL MASS FIELDS AS A 250MB LOW MOVES FROM THE CURRENT POSITION
OVER SRN NV...TO WRN KS AS A SHORTWAVE TROUGH AT THE START OF THE
PERIOD 00Z SUN. AT 00Z SUN...THE 00Z/12 ECMWF IS ABOUT 50-60M DEEPER
AND ALSO MORE NEUTRALLY TILTED WITH 250MB HEIGHT TROUGH THAN THE
POSITIVELY TILTED GFS. THE 12Z/12 NAM IS AN OUTLIER THROUGH THE
PERIOD AS WAS RULES OUT. THE REG-GEM IS MORE OF A MIDDLE GROUND
SOLUTION THROUGH MUCH OF THE EVENT.. THE DIFFERENCES BETWEEN MODELS
CONTINUES AT 12Z SUN...WHEN THE GFS BECOMES NEUTRALLY TILED OVER THE
WRN MO BORDER WHILE THE ECMWF IS STRONGER...FASTER AND NEGATIVELY
TILTED WITH THE UPPER TROUGH OVER IA/NRN MO. EVENTUAL SFC LOW TRACK
DIFFERENCES ARE NOT DIFFERENT...ALTHOUGH THERE ARE STILL DIFFERENCES
IN SFC LOW STRENGTH...BUT SOME OF THE LARGER DIFFERENCES WITH PRECIP
AMOUNTS/PLACEMENT COME AROUND 850MB. WHILE THE STRONGER ECMWF
DEEPENS THE SYSTEM AND BRINGS A STRENGTHENING 850MB LOW FROM NE IA
12Z SUN TO NEAR THE STRAITS OF MACKINAW AROUND 00Z MON...THE GFS
BRINGS THE 850MB LOW FROM NRN LAKE SUPERIOR AT 00Z SUN TO NEAR THE
STRAITS AT 18Z SUN...THEN DEEPENS IT RAPIDLY OVER LAKE HURON BY 00Z
MON AS THE UPPER TROUGH BECOMES NEGATIVELY TILTED AND UPPER JETS
PHASE. WILL BE INTERESTED TO SEE WHAT THE 12Z/12 ECMWF COMES IN
WITH...BECAUSE THE GFS AND GEM HAVE BEEN TRENDING WEAKER /TOWARD
WHAT THEY HAVE NOW/ OVER THE LAST FEW RUNS. THE MAIN IMPACT FROM THE
WEAKER SCENARIO IS THAT THE STRONG DEFORMATION/FGEN ON THE LEFT SIDE
OF THE 850MB LOW TRACK ARE DISPLACES SE OF THE CWA...WHILE THE ECMWF
SOLUTION BRINGS A COUPLE OF INCHES OF RAIN SAT NIGHT INTO SUN.
OVERALL THINK THE BEST CHANCES OF PRECIP WILL BE OVER THE SERN CWA
CLOSER TO LAKE MICHIGAN...BOTH SAT NIGHT WITH THE WARM FRONT THAT
WILL BE JUST S OF THE CWA AND AS THE LOW PASSES SUN. WILL SHIFT POPS
SE FROM WHAT IS CURRENTLY IN THE FORECAST.
LINGERED SOME SLIGHT CHANCE POPS OVER NORTH CENTRAL AND E UPPER MI
INTO EARLY MON AS N WINDS OFF LAKE SUPERIOR MAY BRING IN SOME LAKE
EFFECT/UPSLOPE PRECIP WHILE 850MB TEMPS DECREASE TO AROUND -3C. ANY
PRECIP WILL BE LIGHT...AND SOME SOME LIGHT SNOW MAY MIX IN OVER THE
HIGHER TERRAIN LATE SUN NIGHT/EARLY MON MORNING. AS SFC RIDGE SLIDES
ACROSS THE CWA MON AFTERNOON/EVENING AHEAD OF AN UPPER RIDGE THAT
WILL MOVE OVERHEAD TUE NIGHT INTO EARLY TUE.
AFTER MON THERE IS CONSIDERABLE MODEL DISAGREEMENT...LIMITED
CONFIDENCE IN THE FORECAST...ESPECIALLY POPS. HOWEVER...IT DOES
APPEAR MORE CERTAIN THAT TUE AND WED WILL BE WARMER WITH HIGHS
GENERALLY IN THE 50S. USED CONSENSUS OF MODELS FOR MON NIGHT THROUGH
FRI.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 152 AM EDT SAT OCT 13 2012
VFR CONDITIONS WILL CONTINUE INTO LATE TONIGHT. A STRENGTHENING SSW
FLOW OVERNIGHT BTWN THE DEPARTING HIGH AND LOW PRESSURE TAKING SHAPE
IN THE PLAINS WILL RESULT IN SOME MARGINAL LLWS AS WELL AS
INCREASING CLOUDS. ENOUGH MOISTURE MAY ARRIVE LATE IN THE FCST
PERIOD TO CAUSE MVFR CIGS CLOSER TO THE WI BORDER AT IWD. STRONGER
MOISTURE INFLOW AHEAD OF WARM FRONT OVER WI WILL BRING LOWER CIGS
INTO THE MVFR RANGE AT ALL SITES LATER TODAY. SRLY LOW LEVEL FLOW
FAVORS EVEN LOWER CIGS INTO THE IFR RANGE AT SAW. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 PM EDT FRI OCT 12 2012
A STEADY SSW WIND UP TO 25 KTS WILL PREVAIL TONIGHT BETWEEN THE
DEPARTING HI AND DEVELOPING LO PRES IN THE PLAINS. AS THE LO PRES
CENTER MOVES TO THE E JUST S OF UPPER MI EARLY SUN...LOOK FOR THE
WINDS TO BACK TO THE N AND INCREASE UP TO 25 TO 30 KTS...ESPECIALLY
OVER THE E HALF. MAY SEE A FEW GALE FORCE GUSTS OVER PORTIONS OF
EASTERN LAKE SUPERIOR SUN. THE APPROACH OF HIGH PRES ON MON WILL CAUSE
A STEADY DECREASE IN WIND SPEED LATER SUN INTO MON. SOUTH WINDS WILL
INCREASE TO 25 KTS OVER MAINLY THE ERN HALF OF THE LAKE ON TUESDAY
AHEAD OF A LOW PRESSURE SYSTEM DEVELOPING OVER THE NRN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
306 AM CDT SAT OCT 13 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
306 AM CDT SAT OCT 13 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES THROUGH SUNDAY
AS WELL AS POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON AND EVENING.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED SPLIT FLOW ACROSS NORTH AMERICA. THE NORTHERN STREAM IS A
WEST-NORTHWEST FLOW FROM SOUTHWEST CANADA INTO NEW ENGLAND...WITH A
100 KT JET STREAK PRESENT OVER ONTARIO AT 200MB WITHIN THE FLOW. IN
THE SOUTHERN STREAM...AN UPPER LOW WAS PRESENT OVER WESTERN COLORADO
WITH A POTENT SHORTWAVE IN EASTERN ARIZONA...WHILE SUBTROPICAL
RIDGING WAS BUILDING AHEAD OF IT ACROSS MUCH OF THE MISSISSIPPI
RIVER VALLEY. 850MB PROFILER AND VWP DATA SHOWING SOUTH TO SOUTHWEST
WINDS OF 40-50 KT UNDER THE SUBTROPICAL RIDGE...HELPING TO ADVECT
GULF OF MEXICO MOISTURE TOWARDS THE FORECAST AREA. GOES DERIVED
PRECIPITABLE WATER SHOWED VALUES OF 1.3 INCHES APPROACHING NORTHEAST
IOWA WITH 1.5-1.7 INCH VALUES LURKING TO THE SOUTHWEST IN THE
KANSAS CITY AREA. SHOWER AND THUNDERSTORM DEVELOPMENT HAS BEEN
TAKING PLACE ON THE LEADING EDGE OF THIS MOISTURE SURGE ACROSS
WISCONSIN...AIDED TOO BY THE RIGHT ENTRANCE REGION OF THE NORTHERN
STREAM UPPER JET STREAK. ANOTHER SURGE OF MOISTURE LEADING TO
SHOWER AND THUNDERSTORM DEVELOPMENT OVER EASTERN NEBRASKA INTO
NORTHERN MISSOURI. AT THE SURFACE...A GENERAL LEE TROUGH WAS
PRESENT ALL UP AND DOWN THE WESTERN SIDE OF THE PLAINS...WITH A
RELATIVELY TIGHT PRESSURE GRADIENT PRESENT AHEAD OF THE TROUGH
EASTWARD ACROSS THE FORECAST AREA. THE COMBINATION OF INCREASING
CLOUDS AND WARM/MOIST ADVECTION ON THE SOUTHERLY BREEZE HAVE
HELPED TO BRING TEMPERATURES UP OVERNIGHT.
UPPER LEVEL PATTERN DISCUSSION...MODELS HAVE DEFINITELY TRENDED
FARTHER SOUTH AND SLOWER WITH THE UPPER LOW COMING OUT OF COLORADO
OVER THE PAST FEW DAYS. LATEST 13.00Z GUIDANCE...WHICH FOLLOWS A
SUGGESTION MADE BY THE 12.06Z NAM YESTERDAY...SUGGESTS THE UPPER LOW
IS GOING TO STAY MORE PHASED WITH THE POTENT SHORTWAVE COMING OUT OF
ARIZONA. AS A RESULT...THE UPPER LOW TAKES A TRACK ACROSS KANSAS
THIS AFTERNOON INTO TONIGHT...REACHING WESTERN MISSOURI BY 12Z
SUNDAY. AFTER 12Z SUNDAY...MODELS SPLIT INTO TWO CAMPS WITH THE
EJECTION NORTHEASTWARD OF THE UPPER LOW BY NORTHERN STREAM SHORTWAVE
TROUGHING DROPPING INTO THE NORTHERN PLAINS. THE 13.00Z
GFS/UKMET/CANADIAN/ECMWF TAKE A TRACK THROUGH CHICAGO INTO NORTHERN
LOWER MICHIGAN BY LATE SUNDAY...WHEREAS THE 13.00Z NAM AND 12.21Z
SREF MEAN HAVE A FARTHER SOUTHEAST TRACK TOWARDS TOLEDO OH. THESE
DIFFERENCES IN TRACKS ARE REFLECTED TOO AT THE SURFACE WITH THE
GFS/UKMET/CANADIAN/ECMWF DEPICTING THE ASSOCIATED SURFACE LOW GOING
FROM ST JOSEPH MO THROUGH MILWAUKEE AT 18Z SUNDAY...COMPARED TO THE
NAM/SREF HEADING THROUGH GARY INDIANA AT THE SAME TIME. THIS SETS UP
ISSUES WITH WHERE THE DEFORMATION BAND WILL IMPACT FOR THE TONIGHT
THROUGH SUNDAY TIME PERIOD...DISCUSSED BELOW. PLAN ON TAKING A
COMPROMISE APPROACH TO GIVE CREDIT TO THE NAM SUGGESTING A FARTHER
SOUTH TRACK WITH THE UPPER LOW TODAY.
TODAY...CURRENT AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS OVER
WESTERN WISCONSIN SHOULD KEEP PRESSING EAST THIS MORNING...AS IT IS
TIED TO THE LEADING EDGE OF 850MB MOISTURE TRANSPORT WHICH IS
PUSHING NORTHEAST. ADDITIONAL CONVECTIVE ACTIVITY LOOKS TO DEVELOP
SHORTLY OVER NORTHERN IOWA...AS SUGGESTED BY THE 13.00Z
NAM/CANADIAN/LOCAL WRF RUN...ASSOCIATED WITH THE NOSE OF A SECOND
MAXIMA OF 850MB MOISTURE TRANSPORT WITHIN THE MAIN MOISTURE
TRANSPORT ZONE. THIS COULD BE THE CURRENT CONVECTION SLIDING INTO
SOUTHWEST IOWA TOO ON THE LEADING EDGE OF HIGHER PRECIPITABLE
WATER. THE CONVECTIVE ACTIVITY WOULD SLIDE EAST ACROSS SOUTHERN
PORTIONS OF THE FORECAST AREA THIS MORNING. THUS...HIGHEST
PRECIPITATION CHANCES EXIST SOUTH OF I-90 THIS MORNING. DURING THE
AFTERNOON...PRECIPITATION SIGNALS ARE LESS CLEAR. ALL 850MB
MOISTURE TRANSPORT IS KIND OF POINTED AWAY FROM THE AREA...OR WE
ARE JUST UNDER THE STREAM WITH NO FOCUS AREAS. ALOFT AT
500MB...THERE REALLY IS NO FEATURE TO AID IN CONVECTIVE
DEVELOPMENT...AND IF ANYTHING WE ARE UNDER SOME WEAK SHORTWAVE
RIDGING AHEAD OF THE UPPER LOW. WE DO HAVE A WARM FRONTAL BOUNDARY
EXTENDING ACROSS NORTHERN IOWA INTO SOUTHERN WISCONSIN...WHICH
COMBINED WITH 500-1000 J/KG OF PROGGED MUCAPE COULD TRIGGER
CONVECTION. MODEL QPF FIELDS REFLECT THE LACK OF A PRECIPITATION
FOCUSING MECHANISM AS WELL. AS SUCH...HAVE KNOCKED PRECIPITATION
CHANCES DOWN INTO THE 50-70 RANGE FOR THE AFTERNOON. SHOULD
CONVECTION FIRE NEAR/ALONG THE WARM FRONT... 0-6KM...0-3KM AND
0-1KM SHEAR STILL SUPPORT POTENTIAL FOR SUPERCELLS AND LINE
SEGMENTS...WITH DAMAGING WIND AND TORNADOES POSSIBLE. THE SEVERE
CHANCES REALLY DEPEND ON IF WE CAN GET SOME SUN THIS AFTERNOON TO
HELP REACH THAT PROGGED INSTABILITY...WHICH IS HIGHLY UNCERTAIN
GIVEN THE STREAM OF CLOUDS WITHIN THE 850MB MOISTURE TRANSPORT
ZONE. GREATER CHANCES OF SEVERE WEATHER EXPECTED SOUTH OF THE
FORECAST AREA WHERE DYNAMICAL FORCING IS STRONGER. HIGH
TEMPERATURES ARE TRICKY TODAY. DID END UP COOLING THEM SOME DOWN
INTO THE 50S ALONG AND NORTHEAST OF I-94 WITH THE WARM FRONT
EXPECTED FARTHER SOUTH. ELSEWHERE...ADVECTION AND POTENTIAL FOR
SOME SLIGHT AMOUNT OF SUN SHOULD PUSH HIGHS INTO THE 60S AS
SUGGESTED BY MOST GUIDANCE. SHOULD MORE SUN OCCUR...850MB TEMPS OF
10-13C WOULD ALLOW READINGS TO TOP OUT WELL INTO THE 70S.
TONIGHT INTO SUNDAY...FOLLOWING THE COMPROMISE APPROACH MENTIONED IN
THE UPPER LEVEL DISCUSSION SECTION...WE SHOULD SEE A DEFORMATION
BAND OF PRECIPITATION FORM ON THE NORTH SIDE OF THE WARM FRONT THIS
EVENING. THIS BAND WOULD AFFECT THE SOUTHERN TWO-THIRDS OF THE AREA.
AS THE SURFACE LOW HEADS NORTHEAST INTO FAR SOUTHERN WISCONSIN
SUNDAY MORNING...ANTICIPATE THE BAND TO CONTINUE TO AFFECT THE SAME
AREA AND PERHAPS INTENSIFY AS THE LOW DEEPENS. DUE TO THE SLOWER
PROGRESS OF THE SYSTEM...HAVE HELD ONTO PRECIPITATION CHANCES
LONGER...WITH ONLY SOME OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA
DRYING OUT IN THE AFTERNOON. AN AREA SOUTHEAST OF A LINE FROM
DECORAH TO LA CROSSE AND BLACK RIVER FALLS STILL SEEMS POSSIBLE TO
PICK UP UPWARDS OF 1 TO 2 INCHES DURING THIS TIME PERIOD...
ESPECIALLY IF THE 13.00Z GFS/ECMWF PAN OUT. WITH MORE
CLOUDS/PRECIPITATION ON SUNDAY...COOLED HIGHS DOWN A BIT. MAY HAVE
TO LOWER MORE...AGAIN IF THE 13.00Z GFS/ECMWF PAN OUT. TONIGHTS
LOWS STILL SEEM REASONABLE WITH LITTLE CHANGE NEEDED.
SUNDAY NIGHT THROUGH MONDAY NIGHT...ATTENTION SHIFTS TO HOW QUICKLY
THE UPPER TROUGHING OVER THE FORECAST AREA...LEFT OVER BEHIND THE
STORM SYSTEM AND THE NEXT SHORTWAVE DROPPING INTO THE NORTHERN
PLAINS...SHIFTS OFF TO THE EAST. THE KICKING MECHANISM TO PUSH IT TO
THE EAST IS A SERIES OF SHORTWAVES DROPPING INTO MONTANA ON MONDAY.
THE 13.00Z NAM IS BY FAR THE FASTEST KICKING THE TROUGH OFF TO THE
EAST...RELATED TO THE SPEED OF THE STORM SYSTEM. THE OTHER SIDE OF
THE COIN IS THE 13.00Z GFS WHICH HANGS THE TROUGH UP OVER THE
EASTERN GREAT LAKES FOR MONDAY. THE ECMWF/UKMET LIE BETWEEN THE TWO
AND ARE PREFERRED. SKIES SHOULD GRADUALLY CLEAR SUNDAY NIGHT AS
SUBSIDENCE BUILDS IN BEHIND THE DEPARTING STORM SYSTEM AND HIGH
PRESSURE BUILDS IN AT THE SURFACE. DEPENDING ON THE SPEED OF
CLEARING...COULD SEE LOWS DIP BELOW FREEZING...ESPECIALLY AT THE
TYPICAL COLD SPOTS. DECENT WARMING OCCURS MONDAY...THOUGH...AS THE
SURFACE RIDGE HEADS EAST. 850MB TEMPS COULD POP UP TO 7-11C BY 00Z
TUESDAY. PREVIOUS FORECAST HIGHS HAVE THE WARMING HANDLED WELL.
WARMER NIGHT ON TAP MONDAY NIGHT WITH A RELATIVELY TIGHT PRESSURE
GRADIENT IN PLACE AHEAD OF THE MONTANA SHORTWAVES DROPPING INTO THE
DAKOTAS. NO PRECIPITATION ANTICIPATED WITH A DRY AIRMASS IN PLACE
AND THE BEST FORCING SITUATED NORTH OF THE AREA.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
306 AM CDT SAT OCT 13 2012
GENERAL THEME CONTINUES WITH THE 13.00Z GFS/ECMWF/CANADIAN AND GFS
ENSEMBLES OF DEEP TROUGHING DEVELOPING OVER THE NORTHERN PLAINS AND
UPPER MISSISSIPPI RIVER VALLEY REGION BY THURSDAY. HOWEVER...THE WAY
WE GET THERE IS SLIGHTLY DIFFERENT NOW. AT 12Z TUESDAY...MODELS
DEPICT A POTENT SHORTWAVE COMING INTO SOUTHERN BRITISH COLUMBIA WITH
A 140 KT JET AT 250MB ON ITS SOUTH SIDE. THE SHORTWAVE THEN DIGS
DOWN INTO THE NORTHERN PLAINS WITH ALL MODELS SHOWING UPPER LOW
DEVELOPMENT...PERHAPS AS EARLY AS WEDNESDAY. PRIOR TO THE UPPER LOW
ARRIVAL...THERE IS THOSE SHORTWAVES THAT WERE MOVING INTO THE
DAKOTAS AT 12Z TUESDAY. THESE END UP COMING ACROSS THE FORECAST AREA
TUESDAY NIGHT. ALTHOUGH THE AIRMASS IS SOMEWHAT DRY...THE FORCING
FROM THE WAVE...ESPECIALLY ACROSS NORTHERN PORTIONS OF THE
AREA...MAY BE STRONG ENOUGH TO OVERCOME THE DRY AIR AND RESULT IN
SOME LIGHT PRECIPITATION. NEXT CHANCE OF RAIN COMES WEDNESDAY AS
MOISTURE TRANSPORT AND DPVA INCREASE AHEAD OF THE DEVELOPING UPPER
LOW. THESE CHANCES MAY NEED TO BE RAISED IN FUTURE FORECASTS IF
TRENDS CONTINUE ON THE UPPER LOW DEVELOPMENT. THIS UPPER LOW THEN
SHIFTS INTO THE FORECAST AREA...BRINGING IN COOLER AIR AND LIKELY
MORE SHOWER ACTIVITY. MODELS THEN DIVERGE WITH HOW FAST THE UPPER
LOW LEAVES THE AREA FOR THE END OF THE WEEK. THE ECMWF SUGGESTS IT
GETS CUT OFF DUE TO BUILDING RIDGING ALONG THE EASTERN SEABOARD AND
IN THE WESTERN U.S.. THIS SCENARIO WOULD RESULT IN COOL...SHOWERY
DAYS AND NIGHTS. THE GFS AND MAJORITY OF ITS ENSEMBLES MEMBERS
SUGGEST A SLOW PROGRESSION NORTHEASTWARD...ALLOWING FOR DRYING
CONDITIONS TO COME IN FOR FRIDAY. TAKING THE CONSENSUS APPROACH FOR
NOW WITH 20-30 PERCENT CHANCES. COOL WEATHER STILL LOOKS REASONABLE
EVEN IN THE GFS CAMP AS 850MB TEMPS FALL TO 0-2C.
&&
.AVIATION...THROUGH 06Z SUNDAY
1154 PM CDT FRI OCT 12 2012
FIRST ROUND OF SHOWERS MOVING ACROSS THE AREA NOW WITHOUT ANY
VISIBILITY RESTRICTIONS AND VFR CEILINGS. CONCERNS BASED ON THE
13.00Z NAM AND 12.12Z MESO MODELS IS JUST HOW MUCH RAIN IS GOING
TO DEVELOP OVERNIGHT INTO SATURDAY. REGIONAL RADARS NOT SHOWING A
WHOLE LOT GOING ON TO THE SOUTH AT THIS TIME. HOWEVER...AS THE LOW
LEVEL JET INTERACTS WITH THE WARM FRONT/DEW POINT BOUNDARY ACROSS
CENTRAL IOWA...EXPECT TO SEE AN INCREASE IN THE COVERAGE. THIS MAY
NOT HAPPEN UNTIL LATE TONIGHT OR EARLY SATURDAY MORNING AS INITIAL
DEVELOPMENT WOULD BE TO THE SOUTH WITH THE ACTIVITY THEN MOVING
NORTH. AS A RESULT...PLAN TO JUST STAY WITH VICINITY THUNDER OR
SHOWERS THROUGH THE NIGHT. THEN EXPECT THE ACTIVITY THAT DEVELOPS
TO REDUCE THE VISIBILITY FOR A FEW HOURS SATURDAY MORNING WITH
EITHER VFR OR MVFR BUT TAKING THE CEILINGS DOWN TO IFR. THE
NAM...HI-RES ARW...NMM AND HRRR ALL THEN SHOW THIS ACTIVITY MOVING
OFF TO THE EAST WITH A BREAK DURING THE LATE MORNING INTO THE
AFTERNOON BEFORE THE NEXT ROUND OF DEVELOPS AS THE SURFACE LOW AND
COLD FRONT MOVE IN FROM THE WEST. HOWEVER...WITH THE HIGH RAIN
CHANCES IN THE PUBLIC FORECAST OBLIGATED TO CARRY THUNDER THROUGH
THE DAY EVEN THOUGH IS SEEMS UNLIKELY THAT THIS WILL OCCUR. IT IS
NOW APPEARING THAT THE BEST CHANCE FOR STEADY RAINS WITH REDUCED
VISIBILITY AND IFR CEILINGS WILL OCCUR SATURDAY EVENING AS THE
MAIN SHORT WAVE TROUGH STARTS TO EJECT OUT AND INCREASES THE LIFT
IN THE VICINITY OF THE SURFACE LOW WHICH SHOULD BE OVER WESTERN
IOWA WITH THE WARM FRONT INTO THE AREA. OVERALL CONFIDENCE ON HOW
THIS IS GOING TO ALL PLAY OUT IS NOT HIGH SO NOT A LOT OF DETAILS
IN THE FORECAST YET.
&&
.HYDROLOGY...THROUGH SUNDAY
306 AM CDT SAT OCT 12 2012
QPF FORECAST STILL PROBLEMATIC...AGAIN DUE TO THE TRACK OF THE
STORM SYSTEM. MAIN FOCUS IS GOING TO BE ON THE DEFORMATION BAND ON
THE NORTH SIDE OF THE STORM SYSTEM TRACK...SINCE THIS IS GOING TO
HAVE THE BULK OF THE HEAVIER RAIN. THE LATEST 13.00Z ECMWF PROGS
A BAND OF 3-3.5 INCHES FROM PRAIRIE DU CHEIN NORTHEAST TOWARDS
WISCONSIN RAPIDS. THE 13.00Z GFS IS NOT TOO FAR OFF WITH A SIMILAR
BAND OF 2-4 INCHES IN ABOUT THE SAME PLACE. ON THE OTHER
HAND...THE FARTHER SOUTH AND FASTER 13.00Z NAM ENDS UP PRODUCING
THE HEAVY RAIN BAND ACROSS MUCH OF NORTHERN ILLINOIS. HAVE TAKEN A
COMPROMISE APPROACH BETWEEN THE TWO SCENARIOS...RESULTING IN AN
AREA OF 2 INCHES ACROSS THE SOUTHEASTERN 1/3 OF THE FORECAST AREA.
WILL HAVE TO SEE EVENTUALLY WHERE THE DEFORMATION BAND SETS UP TO
DETERMINE WHICH SCENARIO TO FOLLOW. NEEDLESS TO SAY...THE
LANDSCAPE AND RIVERS REALLY COULD USE THIS RAIN GIVEN THE SEVERE
TO EXTREME DROUGHT CONDITIONS IN PLACE. THEREFORE...NO FLOODING IS
ANTICIPATED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
306 AM CDT SAT OCT 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1154 PM CDT FRI OCT 12 2012
.SHORT TERM...TONIGHT THROUGH MONDAY
345 PM CDT FRI OCT 12 2012
AT 3 PM...A 1030 MB CANADIAN HIGH WAS CENTERED OVER LOWER MICHIGAN.
THIS HIGH KEPT SKIES CLEAR ACROSS THE UPPER MISSISSIPPI RIVER VALLEY
THIS AFTERNOON. DESPITE THE SUNSHINE...TEMPERATURES HAVE ONLY
CLIMBED INTO THE 46 TO 54 DEGREE RANGE. FURTHER SOUTH...CLOUDS HAVE
BEEN RAPIDLY MOVING NORTH INTO SOUTHERN AND WESTERN IOWA. THESE
CLOUDS ARE ASSOCIATED WITH A SHORT WAVE TROUGH THAT IS MOVING
NORTHEAST OUT OF THE SOUTHERN PLAINS. THE 12.12Z MODELS CONTINUE TO
SHOW GOOD CONSISTENCY THAT AS THIS WAVE MOVES NORTHEAST TOWARD OUR
AREA THIS EVENING THERE WILL BE A RAPID INFLUX OF 875 TO 600 MB
MOISTURE INTO THE AREA. THIS WILL RESULT IN THE RAPID DEVELOPMENT OF
SHOWERS ACROSS SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND WESTERN
WISCONSIN BETWEEN 13.03Z AND 13.06Z...AND THEN ACROSS THE REMAINDER
OF THE AREA DURING THE OVERNIGHT. WITH 0-3KM MOST UNSTABLE OF 300 TO
900 J/KG ALONG AND SOUTH OF THE INTERSTATE 90 CORRIDOR...THERE
SHOULD ALSO BE SOME THUNDERSTORMS. WITH THE 1-7 KM BULK SHEAR LESS
THAN 20 KNOTS...NOT EXPECTING ANY OF THESE THUNDERSTORMS TO BECOME
SEVERE.
FOR SATURDAY INTO SUNDAY...THE 12.12Z MODELS ARE STARTING TO
DIVERGE. MUCH OF THIS IS HOW FAST THEY ARE EJECTING THE LOW
PRESSURE SYSTEM OUT OF THE SOUTHWEST UNITED STATES AND HOW IT
INTERACTS WITH THE NORTHERN STREAM TROUGH. THIS ULTIMATELY AFFECTS
THE CYCLOGENESIS THAT MANY OF THE PREVIOUS MODELS HAVE BEEN
SHOWING OVER THE PAST COUPLE OF DAYS OVER THE UPPER MISSISSIPPI
RIVER VALLEY. THE NAM/WRF IS THE SLOWEST AT MOVING THIS WAVE OUT
OF THE SOUTHERN PLAINS. AS A RESULT...IT HAS LITTLE PRECIPITATION
IN THE WAKE OF THE INITIAL SHORT WAVE TROUGH. BY THE TIME THIS
WAVE STARTS TO MOVE NORTHEAST...THE SURFACE LOW IS TOO SOUTHEAST
OF THE FORECAST AREA TO GET MUCH FROM THE LOW PRESSURE SYSTEM ON
SATURDAY NIGHT AND SUNDAY. HOWEVER THE 18Z NAM/WRF IS SHOWING THAT
ANOTHER WAVE WILL COME UP AND IT GENERATES PRECIPITATION DURING
THE AFTERNOON AND EVENING. THE GFS KEEPS SOME INTERACTION BETWEEN
THE NORTHERN AND SOUTHERN STREAMS. THIS RESULTS IN SOME WEAK
CYCLOGENESIS ACROSS THE REGION. AS A RESULT...IT CONTINUES THE
MOISTURE TRANSPORT INTO THE REGION AND THERE ARE SEVERAL ROUND
SHOWERS AND THUNDERSTORMS THAT MOVE THROUGH THE REGION.
FINALLY...THE ECMWF IS SIMILAR TO THE GFS FOR SATURDAY...BUT ON
SATURDAY NIGHT AND SUNDAY IT BRINGS THE SOUTHERN STREAM MUCH
FURTHER NORTHWEST...THEREFORE...IT LINGERS THE PRECIPITATION
THROUGHOUT THE DAY SUNDAY. THIS SOLUTION IS THE WETTEST FOR THE
FORECAST AREA. AS A RESULT...THE FORECAST CONFIDENCE HAS DECLINED
QUITE A BIT. DECIDED THE BEST OPTION WAS TO TRY AND GO WITH A
CONSENSUS FORECAST FOR NOW.
DESPITE THE DIFFERENCES IN THE MODELS...THEY ARE STILL IN AGREEMENT
THAT THERE WILL BE 500 TO 1000 J/KG OF ML CAPE ALONG AND SOUTH OF
THE INTERSTATE 90 CORRIDOR ON SATURDAY AFTERNOON AND EVENING. IN
ADDITION...THE 0-6 KM SHEAR WILL BE FAVORABLE FOR THE DEVELOPMENT OF
SUPERCELLS. THE 0-1 KM SHEAR IS STRONG ENOUGH FOR THE POSSIBILITY OF
TORNADOES. HOWEVER THIS WOULD BE HIGHLY DEPENDENT UPON WHETHER THE
CONVECTION CAN BECOME SURFACE BASED. THIS WOULD ALSO AFFECT OUR
WIND THREAT. WITH THE CAPES BEING SKINNY AND FREEZING LEVELS BEING
HIGH...THERE IS SOME UNCERTAINTY WHETHER THERE WILL BE ANY SEVERE
HAIL. FINALLY...THE CYCLOGENESIS LOOKS MUCH MORE WEAKER. THIS
MEANS THAT THE DYNAMICS ARE MUCH WEAKER. IF SEVERE WEATHER HAPPENS
TO DEVELOP...THE GFS WOULD HAVE ITS THREAT OF SEVERE WEATHER FROM 4 TO
9 PM. MEANWHILE THE NAM/WRF WOULD SUGGEST THAT THE THREAT WOULD
EXIST FROM 12 PM TO 6 PM.
ON MONDAY...THE MAIN FORECAST QUESTION IS HOW WARM WILL WE GET.
THE GFS 850 TEMPERATURES ARE ABOUT 6C COLDER THAN THE NAM/WRF AND
ECMWF. AS RESULT...TOOK THE CONSALL AND BLENDED IT WITH THE ECMWF
TO TREND TOWARD A WARMER SOLUTION.
.LONG TERM...MONDAY NIGHT THROUGH THURSDAY
345 PM CDT FRI OCT 12 2012
LIKE THE PAST COUPLE OF DAYS...THE 12.12Z MODELS ARE IN FAIRLY
GOOD AGREEMENT THAT A BROAD TROUGH DEVELOP ACROSS THE CENTRAL AND
EASTERN UNITED STATES. THE ONLY QUESTION IS HOW DEEP WILL THIS
TROUGH GET AND HOW MUCH COLD AIR IT WILL BRING SOUTHWARD INTO THE
REGION. SINCE THERE CONTINUES TO BE SOME UNCERTAINTY ON
THIS...JUST WENT WITH THE CONSALL.
&&
.AVIATION...THROUGH 06Z SUNDAY
1154 PM CDT FRI OCT 12 2012
FIRST ROUND OF SHOWERS MOVING ACROSS THE AREA NOW WITHOUT ANY
VISIBILITY RESTRICTIONS AND VFR CEILINGS. CONCERNS BASED ON THE
13.00Z NAM AND 12.12Z MESO MODELS IS JUST HOW MUCH RAIN IS GOING
TO DEVELOP OVERNIGHT INTO SATURDAY. REGIONAL RADARS NOT SHOWING A
WHOLE LOT GOING ON TO THE SOUTH AT THIS TIME. HOWEVER...AS THE LOW
LEVEL JET INTERACTS WITH THE WARM FRONT/DEW POINT BOUNDARY ACROSS
CENTRAL IOWA...EXPECT TO SEE AN INCREASE IN THE COVERAGE. THIS MAY
NOT HAPPEN UNTIL LATE TONIGHT OR EARLY SATURDAY MORNING AS INITIAL
DEVELOPMENT WOULD BE TO THE SOUTH WITH THE ACTIVITY THEN MOVING
NORTH. AS A RESULT...PLAN TO JUST STAY WITH VICINITY THUNDER OR
SHOWERS THROUGH THE NIGHT. THEN EXPECT THE ACTIVITY THAT DEVELOPS
TO REDUCE THE VISIBILITY FOR A FEW HOURS SATURDAY MORNING WITH
EITHER VFR OR MVFR BUT TAKING THE CEILINGS DOWN TO IFR. THE
NAM...HI-RES ARW...NMM AND HRRR ALL THEN SHOW THIS ACTIVITY MOVING
OFF TO THE EAST WITH A BREAK DURING THE LATE MORNING INTO THE
AFTERNOON BEFORE THE NEXT ROUND OF DEVELOPS AS THE SURFACE LOW AND
COLD FRONT MOVE IN FROM THE WEST. HOWEVER...WITH THE HIGH RAIN
CHANCES IN THE PUBLIC FORECAST OBLIGATED TO CARRY THUNDER THROUGH
THE DAY EVEN THOUGH IS SEEMS UNLIKELY THAT THIS WILL OCCUR. IT IS
NOW APPEARING THAT THE BEST CHANCE FOR STEADY RAINS WITH REDUCED
VISIBILITY AND IFR CEILINGS WILL OCCUR SATURDAY EVENING AS THE
MAIN SHORT WAVE TROUGH STARTS TO EJECT OUT AND INCREASES THE LIFT
IN THE VICINITY OF THE SURFACE LOW WHICH SHOULD BE OVER WESTERN
IOWA WITH THE WARM FRONT INTO THE AREA. OVERALL CONFIDENCE ON HOW
THIS IS GOING TO ALL PLAY OUT IS NOT HIGH SO NOT A LOT OF DETAILS
IN THE FORECAST YET.
&&
.HYDROLOGY...TONIGHT THROUGH SUNDAY
258 AM CDT FRI OCT 12 2012
QPF WISE FOR THE TONIGHT THROUGH SUNDAY MORNING SYSTEM...REALLY HARD
TO SAY. THE MAXIMUM AREA SHOULD BE OVER THE SOUTHEASTERN 1/3 OF THE
FORECAST AREA...WHERE THE LONGEST PERIOD OF 850MB MOISTURE TRANSPORT
NOSES IN AND THEN GETS HIT BY THE DEFORMATION ON THE BACK SIDE OF
THE SYSTEM. PRECIPITABLE WATER VALUES CLIMB TO AROUND 1.5 INCHES OR
200-250 PERCENT OF NORMAL TONIGHT AND HOVER AROUND THERE INTO SUNDAY
MORNING. POTENTIAL IS DEFINITELY THERE TO GET 1 TO 2 INCHES FOR THE
ENTIRE TIME PERIOD...AS SUGGESTED BY HPC FORECASTS AND SREF
PROBABILITIES...WITH LOCALLY HIGHER AMOUNTS DUE TO THE CONVECTIVE
NATURE. IN FACT...THE LATEST 12.00Z ECMWF HAS UPWARDS OF 3-3.5
INCHES. THE LANDSCAPE AND RIVERS REALLY COULD USE THIS RAIN GIVEN
THE SEVERE TO EXTREME DROUGHT CONDITIONS IN PLACE. THEREFORE...NO
FLOODING IS ANTICIPATED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
345 PM CDT FRI OCT 12 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS MIAMI FL
1051 AM EDT SAT OCT 13 2012
.UPDATE...
NO MAJOR UPDATES ARE ANTICIPATED THIS MORNING AS THE PREVIOUS
FORECAST PACKAGE REMAINS ON TRACK. WE DID SLIGHTLY ADJUST TO
GRIDDED TEMPERATURE DATABASE BASED ON THE LATEST OBSERVATIONS THIS
MORNING...WHICH WERE RUNNING SLIGHTLY COOLER INLAND THAN WHAT WAS
FORECAST. THE LATEST RADAR LOOP SHOWED ISOLATED TO SCATTERED
SHOWERS SPREADING ASHORE ALONG PORTIONS OF THE EAST COAST AREAS
WITHIN THE BREEZY NE FLOW. THE LATEST HRRR MODEL REFLECTIVITIES
INITIALIZED WELL WITH THIS PATTERN AND SHOWED A SIMILAR TREND
CONTINUING THROUGH THE REMAINDER OF THE DAY. 85/AG
&&
.PREV DISCUSSION... /ISSUED 733 AM EDT SAT OCT 13 2012/
AVIATION...
STRONG NORTHEAST FLOW WILL CONTINUE TO BUILD INTO THE
REGION THIS MORNING AND IS EXPECTED TO PERSIST THROUGH THE DAY.
STRATOCUMULUS IN THE 3 KFT TO 6 KFT RANGE WITH EMBEDDED SHOWERS WILL
CONTINUE TO STREAM SOUTHWEST ACROSS THE ATLANTIC WATERS WITH THE
EAST COAST TAF SITES EXPERIENCING BRIEF PASSING SHOWERS FROM TIME TO
TIME WITH GUSTS TO NEAR 30 KNOTS OCCASIONALLY WITH A PASSING SHOWER
WITH VERY BRIEF SUB-VFR CONDITIONS POSSIBLE.
PREV DISCUSSION... /ISSUED 452 AM EDT SAT OCT 13 2012/
UPDATE...SHOWERS HAVE INCREASED IN COVERAGE ACROSS THE ATLANTIC
WATERS AND IR SATELLITE IMAGERY SHOWS A BAND OF MOISTURE EXTENDING
ACROSS GRAND BAHAMA AND TO THE NORTH WITH MOVEMENT TOWARDS SOUTH
FLORIDA. GIVEN THIS CURRENT TREND, HAVE UPDATED THE POPS INTO THE
SCATTERED CATEGORY FOR THE INTERIOR/EAST COAST TODAY ALONG WITH
INCREASING SKY COVER AS WELL. /GREGORIA
PREV DISCUSSION... /ISSUED 319 AM EDT SAT OCT 13 2012/
WINDY THIS WEEKEND WITH A HIGH RISK OF RIP CURRENTS ATLANTIC COAST...
FEW FAST MOVING SHOWERS EXPECTED, FOCUSED EAST COAST, BECOMING
SCATTERED SUNDAY WITH A SLIGHT CHANCE OF THUNDERSTORMS...
DISCUSSION...
THE PRESSURE GRADIENT WILL CONTINUE TIGHT ACROSS SOUTH FLORIDA
THROUGH SUNDAY, DUE TO STRONG HIGH PRESSURE OVER THE MID ATLANTIC
STATES AND T.D. PATTY EAST OF THE BAHAMAS, WHICH IS FORECAST BY NHC
TO DISSIPATE INTO A REMNANT LOW BY THIS EVENING WHILE MOVING SW. THE
RESULT ACROSS SOUTH FL WILL BE WINDY CONDITIONS THROUGH SUNDAY,
ESPECIALLY ALONG THE ATLANTIC COAST, ALONG WITH INCREASING MOISTURE
FROM THE EAST. AS THE REMNANTS OF PATTY MOVE OVER THE STRAITS AND
CUBA SUN-MON, MOISTURE WILL CONTINUE TO INCREASE WELL NORTH OF THIS
FEATURE. THE PWAT IS FORECAST TO INCREASE FROM AROUND AN INCH NOW TO
1.6-1.8" BY SUN AFTERNOON. THIS WILL LEAD TO A BETTER CHANCE OF FAST
MOVING SHOWERS SUN-SUN NIGHT. FORECAST SOUNDINGS SHOW THE CAP IN
PLACE NOW ERODING WITH MORE INSTABILITY, SO CANNOT RULE OUT A TSTORM
OR TWO AS WELL SO PLACED A SLIGHT CHANCE IN THE FORECAST SUN-MON.
STRONG RIP CURRENTS ARE LIKELY ALONG THE ATLANTIC BEACHES THROUGH
THE WEEKEND. MINOR COASTAL FLOODING WILL BE POSSIBLE IN THE MORE
VULNERABLE LOCALES ALONG THE ATLANTIC COAST, DUE TO A COMBINATION OF
HIGHER THAN NORMAL TIDES AND THE STRONG ONSHORE WIND FLOW. WILL
CONTINUE TO HIGHLIGHT THIS, ESPECIALLY THE RIPS WHICH ARE THE
BIGGEST THREAT.
WINDS BEGIN TO WEAKEN SUN NIGHT-MON AS THE ATLANTIC HIGH MOVES EAST.
BOTH GFS/ECMWF SHOW A SHORTWAVE TROUGH MOVING ACROSS THE EASTERN
STATES MON NIGHT-TUE. THIS IS FORECAST TO TAKE T.S. RAFAEL, NOW OVER
THE EASTERN CARIBBEAN, ON A NNW TRACK THEN RECURVING OUT TO SEA
TOWARDS BERMUDA AS PER NHC. LOCALLY, A WEAKENING COLD FRONTAL
BOUNDARY WILL MOVE INTO SOUTH FL MON NIGHT AND MOVE JUST SOUTH OF
THE AREA TUE-WED WITH HIGH PRESSURE RE-BUILDING TO THE NORTH. THIS
WILL LEAD TO A DECREASING MOISTURE TREND SO WILL CONTINUE WITH LOW
POPS THIS PERIOD. SO THE MID/LATE PERIOD NEXT WEEK LOOKS RATHER
TRANQUIL WITH NO MAJOR WEATHER SYSTEMS EXPECTED. HUMIDITY WILL
GRADUALLY INCREASE OVER THE NEXT FEW DAYS BUT IT NEVER GETS OUT OF
HAND.
LOOKING WAY OUT INTO THE EXTENDED FOR NEXT WEEKEND - ECWMF AND GFS
BOTH SHOW A DEEPENING MID/UPPER CLOSED LOW MOVING FROM THE GREAT
LAKE TO NEW ENGLAND. THE 12.12Z ECMWF AMPLIFIED THE TROUGH,
SENDING A STRONG COLD FRONT ACROSS SOUTH FL WITH DEWPOINTS FALLING
INTO THE 40S AND 50S! HOWEVER, THE LATEST ECMWF RUN IS NOT AS
STRONG AND THE LATEST GFS RUN IS NOT AS AGGRESSIVE WITH THE
TROUGH, BRINGING A COLD FRONT THROUGH BRIEFLY NEXT WEEKEND WITH A
QUICK TURN OF THE WINDS TO THE NORTHEAST, KEEPING CONDITIONS WARM
AND RATHER HUMID. NO SIGNIFICANT WEATHER IS EXPECTED THROUGH THE
PERIOD.
MARINE...OBS SHOW SUSTAINED WINDS NEAR 20 KT ACROSS THE WATERS.
WILL CONTINUE THE SMALL CRAFT ADVISORY FOR THE ATLANTIC, BISCAYNE
BAY AND THE LAKE...AND ADD THE OFFSHORE GULF WATERS AS WELL. WINDS
WILL STAY UP THROUGH TONIGHT THEN BEGIN TO GRADUALLY SUBSIDE SUN-
MON. SEAS WILL CONTINUE AT 7 FT OR HIGHER ACROSS THE ATLANTIC
THROUGH SUNDAY BEFORE GRADUALLY SUBSIDING.
FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN WELL
ABOVE CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 85 78 87 76 / 40 20 40 30
FORT LAUDERDALE 85 78 88 79 / 40 20 40 40
MIAMI 85 79 88 77 / 40 20 40 40
NAPLES 89 72 90 75 / 20 10 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH SUNDAY EVENING FOR COASTAL BROWARD-
COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR BISCAYNE BAY-
LAKE OKEECHOBEE.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT SUNDAY FOR COASTAL WATERS
FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-COASTAL
WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING
FROM 20 NM TO THE TERRITORIAL WATERS OF THE BAHAMAS-WATERS
FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20
NM TO 60 NM.
GM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR GULF WATERS FROM
CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING FROM 20 TO 60 NM.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1032 AM CDT SAT OCT 13 2012
.DISCUSSION...
ISSUED 1030 AM CDT SAT OCT 13 2012
ELEVATED SHOWERS AND THUNDERSTORMS WERE WIDESPREAD ACROSS THE
NORTHERN HALF OF ILLINOIS AT 10 AM. WILL CONTINUE TO SEE THAT
SPREAD EASTWARD THE REMAINDER OF THE MORNING...BEFORE A BREAK IN
THE RAIN OCCURS EARLY THIS AFTERNOON. MAIN QUESTION WILL BE HOW
MUCH RENEWED INSTABILITY CAN DEVELOP THIS AFTERNOON. TEMPERATURES
CURRENTLY ONLY IN THE 50S OVER ALMOST ALL THE CWA EXCEPT THE
EXTREME SOUTHEAST. LOW CLOUDS WERE EXTENSIVE WESTWARD ALL THE WAY
INTO KANSAS...ALTHOUGH RECENT VISIBLE SATELLITE IMAGERY SHOWING
SOME SIZABLE BREAKS DEVELOPING IN CENTRAL MISSOURI. LATEST RAP...
HRRR AND NAM SHOWING SHOWERS AND STORMS CURRENTLY IN NORTHWEST
MISSOURI AND EASTERN KANSAS ADVECTING NORTHEAST...WITH SOME
ADDITIONAL REDEVELOPING OVER NORTHERN MISSOURI THIS AFTERNOON
BEFORE MOVING INTO ILLINOIS.
UPDATED ZONES/GRIDS WERE SENT ABOUT A HALF HOUR AGO TO ADDRESS THE
LATEST RAIN AND TEMPERATURE TRENDS. WILL NEED TO MONITOR
TEMPERATURES CLOSELY...AS THE RAIN AND EXTENSIVE CLOUD COVER WILL
LIKELY PREVENT ANY RAPID WARM UPS. TEMPERATURES WERE LOWERED BY A
FEW DEGREES IN THE RECENT UPDATE.
GEELHART
&&
.AVIATION...
ISSUED 658 AM CDT SAT OCT 13 2012
PERIODS OF SHOWERS AND THUNDERSTORMS WILL IMPACT THE CENTRAL
ILLINOIS TERMINALS THROUGH THE 12Z TAF VALID TIME AS A SLOW MOVING
STORM SYSTEM MOVES THROUGH THE AREA. THE FIRST WAVE SHOULD MOVE
THROUGH MAINLY KPIA/KBMI/KSPI IN THE NEXT FEW HOURS...WITH
KDEC/KCMI MISSING OUT FOR NOW. A PERIOD OF MVFR CIGS WILL DEVELOP
SHORTLY AND LAST INTO THE AFTERNOON UNTIL DIURNAL MIXING AND THE
PASSAGE OF A WARM FRONT LIFT THEM BACK TO VFR. EXPECT
PRECIPITATION COVERAGE TO BECOME MORE WIDESPREAD TONIGHT AHEAD OF
AN ADVANCING COLD FRONT...BUT LIMITED THUNDER MENTION TO VCTS UNTIL
COVERAGE IS BETTER DEFINED. CIGS SHOULD GRADUALLY DROP BACK TO
MVFR AS PRECIP EXPANDS TONIGHT. GUSTY SOUTHERLY WINDS ARE EXPECTED
TODAY...ESPECIALLY TOWARD MIDDAY IN THE WAKE OF THE WARM FRONT.
EXPECT THE GUSTS TO DROP OFF TONIGHT AWAY FROM ANY STORMS...BUT
THEY SHOULD HOLD ABOVE 10 KTS.
BAK
&&
.PREV DISCUSSION...
ISSUED 327 AM CDT SAT OCT 13 2012
SHORT TERM...TODAY THROUGH SUNDAY
MAIN CONCERNS THIS FORECAST PERIOD WILL BE ANTICIPATED CONVECTION
AND ANY ASSOCIATED STRONG/SEVERE STORMS AND HEAVY RAINFALL.
ELEVATED CONVECTION WAS ONGOING IN NORTHERN IL...AS WELL AS
NORTHERN AND CENTRAL MO. THIS WAS ASSOCIATED WITH LOWER LEVEL WARM
AIR ADVECTION/ISENTROPIC LIFT. THE GFS 300K SURFACE INDICATED THAT
THIS WILL CONTINUE THROUGH MUCH OF THE MORNING IN NORTHERN AND
CENTRAL IL. THE HRRR MODEL CONCURS THAT PERIODS OF SHOWERS AND
T-STORMS CAN BE EXPECTED THIS MORNING... ESPECIALLY ALONG AND
NORTH OF A TAYLORVILLE- DANVILLE LINE.
HIGH TEMPERATURES...AND PARTICULARLY SFC BASED INSTABILITY...WILL BE
CHALLENGING BECAUSE OF CONVECTIVE DEBRIS AS WELL AS PLENTY OF LOW
LEVEL MOISTURE AND AN INVERSION ON FORECAST SOUNDINGS UNTIL LATE
THIS AFTERNOON IN CENTRAL IL. WILL KNOCK DOWN HIGH TEMPS IN CENTRAL
IL AS A RESULT...BUT KEEP WARMER READINGS IN THE SOUTHEAST.
DESPITE MARGINAL INSTABILITY IN MOST AREAS THIS EVENING...INCREASING
UPPER LEVEL DIVERGENCE AHEAD OF AN UPPER LOW IN NORTHEAST KS ALONG
WITH 30-40KTS OF BULK SHEAR WILL RESULT IN A DEVELOPING LINE OF
STORMS APPROACHING WEST CENTRAL IL LATE THIS EVENING.
UNIDIRECTIONAL FLOW ALOFT AND INCREASING LOW LEVEL WINDS BELOW
850 MB COULD RESULT IN GUSTY WINDS WITH THE STRONGEST STORMS.
WITH EACH SUCCESSIVE MODEL RUN A BIT SLOWER...AM NOT EXPECTING THE
T-STORMS TO REACH EXTREME EAST AND SOUTHEAST IL UNTIL VERY LATE
TONIGHT. EXPECT SHOWERS AND ISOLATED T-STORMS TO LINGER IN
CENTRAL IL MUCH OF THE DAY SUNDAY AHEAD OF THE UPPER LEVEL TROUGH
AXIS...BEFORE DEPARTING THE STATE LATE SUNDAY NIGHT.
LONG TERM...MONDAY THROUGH FRIDAY
A SEMI-ZONAL FLOW WILL DEVELOP AFTER THE UPPER LEVEL TROF
DEAMPLIFIES AND LIFTS THROUGH THE NEW ENGLAND STATES LATER MONDAY
AND TUESDAY. THIS WILL RESULT IN TEMPERATURES CLOSE TO SEASONAL
NORMALS FOR MID-OCTOBER.
THE NEXT CHANCE FOR PRECIPITATION IS EXPECTED LATE TUESDAY
NIGHT...BUT PARTICULARLY WEDNESDAY AS AN UPPER LEVEL TROUGH FROM
THE PACIFIC NORTHWEST CROSSES INTO THE NORTHERN PLAINS AND DEEPENS
IN THE UPPER MIDWEST. THERE IS CONSIDERABLE MODEL UNCERTAINTY AT
THIS POINT WITH THE SPEED OF THE SYSTEM AND JUST HOW FAR SOUTH THE
UPPER LEVEL LOW WILL DEVELOP AND HOW STRONG IT WILL BE. FOR NOW
WILL GO WITH SHOWERS AND A FEW T-STORMS AHEAD OF THE SURFACE COLD
FRONT WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY SOMEWHAT COOLER
TEMPERATURES IN THE LOWER TO MIDDLE 60S.
WILL NEED TO KEEP AN EYE ON THIS SYSTEM BECAUSE IF THE UPPER LOW
SETTLES OVER THE MIDWEST THEN TEMPERATURES WILL BE QUITE CHILLY
WITH RAINY CONDITIONS FOR FRIDAY AND BEYOND.
MILLER
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
658 AM CDT SAT OCT 13 2012
.DISCUSSION...
ISSUED 327 AM CDT SAT OCT 13 2012
SHORT TERM...TODAY THROUGH SUNDAY
MAIN CONCERNS THIS FORECAST PERIOD WILL BE ANTICIPATED CONVECTION
AND ANY ASSOCIATED STRONG/SEVERE STORMS AND HEAVY RAINFALL.
ELEVATED CONVECTION WAS ONGOING IN NORTHERN IL...AS WELL AS
NORTHERN AND CENTRAL MO. THIS WAS ASSOCIATED WITH LOWER LEVEL WARM
AIR ADVECTION/ISENTROPIC LIFT. THE GFS 300K SURFACE INDICATED THAT
THIS WILL CONTINUE THROUGH MUCH OF THE MORNING IN NORTHERN AND
CENTRAL IL. THE HRRR MODEL CONCURS THAT PERIODS OF SHOWERS AND
T-STORMS CAN BE EXPECTED THIS MORNING... ESPECIALLY ALONG AND
NORTH OF A TAYLORVILLE- DANVILLE LINE.
HIGH TEMPERATURES...AND PARTICULARLY SFC BASED INSTABILITY...WILL BE
CHALLENGING BECAUSE OF CONVECTIVE DEBRIS AS WELL AS PLENTY OF LOW
LEVEL MOISTURE AND AN INVERSION ON FORECAST SOUNDINGS UNTIL LATE
THIS AFTERNOON IN CENTRAL IL. WILL KNOCK DOWN HIGH TEMPS IN CENTRAL
IL AS A RESULT...BUT KEEP WARMER READINGS IN THE SOUTHEAST.
DESPITE MARGINAL INSTABILITY IN MOST AREAS THIS EVENING...INCREASING
UPPER LEVEL DIVERGENCE AHEAD OF AN UPPER LOW IN NORTHEAST KS ALONG
WITH 30-40KTS OF BULK SHEAR WILL RESULT IN A DEVELOPING LINE OF
STORMS APPROACHING WEST CENTRAL IL LATE THIS EVENING.
UNIDIRECTIONAL FLOW ALOFT AND INCREASING LOW LEVEL WINDS BELOW
850 MB COULD RESULT IN GUSTY WINDS WITH THE STRONGEST STORMS.
WITH EACH SUCCESSIVE MODEL RUN A BIT SLOWER...AM NOT EXPECTING THE
T-STORMS TO REACH EXTREME EAST AND SOUTHEAST IL UNTIL VERY LATE
TONIGHT. EXPECT SHOWERS AND ISOLATED T-STORMS TO LINGER IN
CENTRAL IL MUCH OF THE DAY SUNDAY AHEAD OF THE UPPER LEVEL TROUGH
AXIS...BEFORE DEPARTING THE STATE LATE SUNDAY NIGHT.
LONG TERM...MONDAY THROUGH FRIDAY
A SEMI-ZONAL FLOW WILL DEVELOP AFTER THE UPPER LEVEL TROF
DEAMPLIFIES AND LIFTS THROUGH THE NEW ENGLAND STATES LATER MONDAY
AND TUESDAY. THIS WILL RESULT IN TEMPERATURES CLOSE TO SEASONAL
NORMALS FOR MID-OCTOBER.
THE NEXT CHANCE FOR PRECIPITATION IS EXPECTED LATE TUESDAY
NIGHT...BUT PARTICULARLY WEDNESDAY AS AN UPPER LEVEL TROUGH FROM
THE PACIFIC NORTHWEST CROSSES INTO THE NORTHERN PLAINS AND DEEPENS
IN THE UPPER MIDWEST. THERE IS CONSIDERABLE MODEL UNCERTAINTY AT
THIS POINT WITH THE SPEED OF THE SYSTEM AND JUST HOW FAR SOUTH THE
UPPER LEVEL LOW WILL DEVELOP AND HOW STRONG IT WILL BE. FOR NOW
WILL GO WITH SHOWERS AND A FEW T-STORMS AHEAD OF THE SURFACE COLD
FRONT WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY SOMEWHAT COOLER
TEMPERATURES IN THE LOWER TO MIDDLE 60S.
WILL NEED TO KEEP AN EYE ON THIS SYSTEM BECAUSE IF THE UPPER LOW
SETTLES OVER THE MIDWEST THEN TEMPERATURES WILL BE QUITE CHILLY
WITH RAINY CONDITIONS FOR FRIDAY AND BEYOND.
MILLER
&&
.AVIATION...
ISSUED 658 AM CDT SAT OCT 13 2012
PERIODS OF SHOWERS AND THUNDERSTORMS WILL IMPACT THE CENTRAL
ILLINOIS TERMINALS THROUGH THE 12Z TAF VALID TIME AS A SLOW MOVING
STORM SYSTEM MOVES THROUGH THE AREA. THE FIRST WAVE SHOULD MOVE
THROUGH MAINLY KPIA/KBMI/KSPI IN THE NEXT FEW HOURS...WITH
KDEC/KCMI MISSING OUT FOR NOW. A PERIOD OF MVFR CIGS WILL DEVELOP
SHORTLY AND LAST INTO THE AFTERNOON UNTIL DIURNAL MIXING AND THE
PASSAGE OF A WARM FRONT LIFT THEM BACK TO VFR. EXPECT
PRECIPITATION COVERAGE TO BECOME MORE WIDESPREAD TONIGHT AHEAD OF
AN ADVANCING COLD FRONT...BUT LIMITED THUNDER MENTION TO VCTS UNTIL
COVERAGE IS BETTER DEFINED. CIGS SHOULD GRADUALLY DROP BACK TO
MVFR AS PRECIP EXPANDS TONIGHT. GUSTY SOUTHERLY WINDS ARE EXPECTED
TODAY...ESPECIALLY TOWARD MIDDAY IN THE WAKE OF THE WARM FRONT.
EXPECT THE GUSTS TO DROP OFF TONIGHT AWAY FROM ANY STORMS...BUT
THEY SHOULD HOLD ABOVE 10 KTS.
BAK
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
711 AM CDT SAT OCT 13 2012
.SHORT TERM /TODAY/...
MAIN CONCERN THIS MORNING IS OBVIOUSLY CONVECTIVE TRENDS. LONG WAVE
TROUGH CONTINUES TO MOVE ACROSS THE ROCKIES WITH ASSOCIATED WARM
FRONT FROM WY/SD SURFACE LOW THROUGH MO VALLEY. RAP ANALYSIS
APPEARS TO BE HANDLING CURRENT WEATHER WELL SHOWING INTENSIFYING
THETA-E ADVECTION COINCIDENT WITH NARROW NW-SE MCS FROM NE INTO MO.
REMNANT MCS THAT FORMED NEAR PARENT UPPER LOW IN THE ROCKIES
CONTINUES TO ADVANCE ACROSS KS INTO NE...MERGING WITH WARM ADVECTION
CONVECTION. RAP 300-310K ISENT LAYER ROOTED AT TOP OF INVERSION
ADVANCES THIS MCS INTO IA AND MATURES IT THROUGH THE MORNING WITH
STRONG MOISTURE TRANSPORT. ELEVATED CAPES APPEAR TO BE AROUND 1000
J/KG WITH MARGINAL EFFECTIVE SHEAR UPSTREAM INTO IMMEDIATE MO RIVER
VALLEY. HOWEVER ESTIMATED RAP EFFECTIVE SHEAR /1-6KM/ WANES SO
REALLY DO NOT EXPECT MUCH IN THE WAY OF SEVERE WEATHER THIS
MORNING...JUST MUCH NEEDED RAIN. THE LATEST HRRR SUPPORTS THIS AS
WELL AND SEEMS TO BE CLOSER TO REALITY...UNLIKE MOST WRF RUNS...SO
WIDESPREAD CATEGORICAL POPS HAVE BEEN INCLUDED.
QUESTION BY THIS AFTERNOON TURNS TO SEVERE WEATHER POTENTIAL ALONG
WITH LESS CONFIDENCE. 60F PLUS DEWPOINTS CURRENTLY NOTED SOUTH OF
WARM FRONT ACROSS KS SHOULD ENTER IA BY THIS AFTERNOON RESULTING IN
MAX MLCAPES AROUND 1500 J/KG AND LITTLE CINH. THIS THERMODYNAMIC
ENVIRONMENT WOULD BE COINCIDENT WITH FAVORABLE DEEP SHEAR FOR
SUPERCELLS AND SHALLOW SHEAR FOR A FEW TORNADOES...ESPECIALLY S
CENTRAL/SE LATE. AGREE WITH SPC LOW TOR PROBS SOUTH BECAUSE OF
THIS...BUT UNIDIRECTIONAL S/SWLY FLOW IS NOT TOO CONDUCIVE.
HOWEVER ANOTHER QUESTION WILL BE INITIATION OR SOURCE. FRONTAL
SYSTEM AND CONVERGENCE WILL LAG THIS AREA CONSIDERABLY...STILL BACK
INTO KS/NE/NWRN IA BY 00Z...AS IS STRONGER H7/H5 FORCING IMMEDIATELY
AHEAD OF PARENT LOW. MINOR WAVES AND H85/H7 FORCING EJECTING OUT IN
SWLY UPPER FLOW COULD FORM ANOTHER MCS...OR REMNANTS FROM SRN TAIL
END OF CURRENT KS CONVECTION COULD EVENTUALLY REACH IA. HOWEVER
THIS DEVELOPMENTAL UNCERTAINTY...AND THE POTENTIAL THAT MORNING MCS
COULD HINDER THE THERMODYNAMIC ENVIRONMENT...HAS MADE THIS SEVERE
WEATHER CONDITIONAL AND LESS CERTAIN. MANY MODELS STILL DEVELOP
SOMETHING FROM THE SOUTH INTO SRN IA HOWEVER SO ALTHOUGH DETAILS NOT
CLEAR...HAVE INTRODUCED SEVERE WORDING SOUTH.
REGARDLESS OF PRECIP TRENDS...AIRMASS SHOULD FEEL SUMMERLIKE WITH
MODEL CONSENSUS PUSHING HIGHS INTO THE 70S AND DEWPOINTS INTO THE
60S. RAW MODEL TEMPS AND MOS GUIDANCE ALL SEEM TO BE IN AGREEMENT
ON THIS.
.LONG TERM /TONIGHT THRU FRIDAY/...
MODELS HAVE COME TOGETHER FOR THE MOST PART WITH THE TIMING AND
EVOLUTION OF THE LOW THIS EVENING. SURFACE LOW WILL TRACK ACROSS
IOWA...MOST LIKELY THE SOUTH HALF...THIS EVENING AND KEPT A SHORT
WINDOW FOR POTENTIAL SEVERE. THAT WILL BE OUT OF THE PICTURE BY
03Z. CHANGE IN THE EVOLUTION FROM PREVIOUS RUNS IS THE TRACK A BIT
FARTHER SOUTH...RESULTING IN A DECENT DEFORMATION ZONE CROSSING IOWA
TONIGHT AND LINGERING WELL IN TO SUNDAY MORNING. MADE ADJUSTMENTS
TO COVER THAT BOTH WITH INCREASING POPS AS WELL AS LOWERING MAX
TEMPS FOR SUN. THE NEXT WEATHER SYSTEM IS SLATED TO ARRIVE MID
WEEK. A BIG DIFFERENCE BETWEEN THE GEM AND ECMWF SOLUTIONS AND THE
GFS WITH THE DEEPENING OF THE UPPER LOW. GEM AND EC BOTH SUGGEST
COOLER AND WETTER WEATHER IS IN STORE. CURRENTLY...PRECIP IS IN FOR
THE WED TIME FRAME. KEPT IT IN THE NERN ZONES FOR THE LATER PART OF
THE WEEK...BUT MAY HAVE TO BE ADJUSTED FARTHER SOUTH AND WEST WITH
LATER PACKAGES. WITH THE SYSTEM DURING MID WEEK BEING FROM THE
NORTHERN STREAM INSTEAD OF THE SOUTHERN BRANCH...DON`T SEE THE
THUNDER THREAT AS BEING A BIG DEAL.
&&
.AVIATION...13/12Z
PERIOD OF IFR CONDITIONS ANTICIPATED EARLY THIS MORNING AS SHOWERS
AND THUNDERSTORMS MOVE THROUGH. THIS SHOULD BE FOLLOWED BY A BREAK
IN THE PRECIPITATION BUT PERSISTENT STRATUS WILL MAINTAIN ITSELF
WITH MVFR CIGS MOST PROMINENT. COULD BE LOWER BUT CONFIDENCE IN
THAT TIMING ENOUGH TO MENTION. ADDITIONAL SHOWERS AND STORMS MAY
DEVELOP THIS AFTERNOON AND EVENING SOUTH. LOW CONFIDENCE ON TIMING
AND LOCATION HOWEVER SO NOTHING MORE THAN MVFR OR LESS CIGS AND
VCSH. FARTHER NORTH STRATUS WILL PERSIST...BUT POTENTIAL FOR
THUNDER IS LESS AND MORE LIKELY JUST STEADY RAIN OR SHOWERS DURING
THE EVENING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/AVIATION...SMALL
LONG TERM...MS OCT 12
AREA FORECAST DISCUSSION
NWS WICHITA KS
657 AM CDT SAT OCT 13 2012
.AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
WIDESPREAD SHOWERS AND THUNDERSTORMS WERE ONGOING ACROSS MUCH OF
CENTRAL AND SOUTH CENTRAL KANSAS THIS MORNING WITH MVFR
CIGS/VISIBILITIES PREVAILING. THIS ACTIVITY WILL CONTINUE TO DEVELOP AND
MOVE EASTWARD IMPACTING SOUTHEAST KANSAS THROUGH THE MORNING
HOURS. A VIGOROUS STORM SYSTEM OVER THE CENTRAL AND SOUTHERN
ROCKIES WILL MOVE EAST AND THUNDERSTORMS ARE EXPECTED TO REDEVELOP
ALONG A PACIFIC FRONT ACROSS CENTRAL KANSAS THIS AFTERNOON. SEVERE
THUNDERSTORMS WILL LIKELY IMPACT PORTIONS OF CENTRAL AND MUCH OF SOUTH
CENTRAL AND SOUTHEAST KANSAS THIS AFTERNOON AND EVENING BEFORE
DEPARTING EAST DURING THE OVERNIGHT HOURS.
MWM
&&
.PREV DISCUSSION... /ISSUED 321 AM CDT SAT OCT 13 2012/
DISCUSSION...
TODAY AND TONIGHT:
ONGOING CONVECTION ACROSS WESTERN KANSAS IS MAKING THE CONVECTIVE
FORECAST FOR LATER TODAY A LITTLE MURKY. SYNOPTIC MODELS DID NOT
HANDLE CONVECTION EVOLUTION DURING THE OVERNIGHT HOURS VERY
WELL...WITH MESO-SCALE MODELS PERFORMING ONLY SLIGHTLY BETTER.
RUC13 APPEARS TO HAVE THE BEST HANDLE ON CONVECTIVE EVOLUTION IN
THE VERY SHORT TERM...THUS WILL USE IT AS A GUIDE AT LEAST THROUGH
THE MORNING HOURS.
AFTER MORNING CONVECTION MOVES EAST OF THE CWA...EXPECT A BRIEF
LULL IN ACTIVITY DUE TO SUBSIDENCE BEHIND MORNING
CONVECTION...BEFORE STORMS RE-FIRE BY EARLY TO MID-AFTERNOON.
TIMING OF WHEN STORMS WILL RE-FIRE AND EXACTLY WHERE STILL IS
UNCLEAR...BUT JUXTAPOSITION OF BEST KINEMATICS AND INSTABILITY
SUGGEST INITIATION SHOULD OCCUR IN THE SOUTHWEST CORNER OF CWA.
FORECAST SOUNDINGS NOT DEPICTING LARGE CAPE VALUES...WITH LARGE
SCALE MOISTURE FLUX LIMITING AMOUNT OF MID-LEVEL DRYING. LARGE
SCALE KINEMATICS SUGGEST CONVECTION WILL BE MAINLY LINEAR IN
NATURE...HOWEVER NAM AND RUC HINT AT A DEVELOPMENT OF MESOLOW
ALONG OR JUST NORTH OF OK-KS BORDER...WHICH COULD INCREASE LOW
LEVEL HELICITY ENOUGH TO ALLOW ISOLATED SUPERCELL TO DEVELOP. FEEL
ANY ISOLATED STORM THAT DEVELOPS WILL NOT LAST TOO LONG...WITH
QLCS BEING THE DOMINATE CONVECTION MODE. BEST POTENTIAL FOR SEVERE
CONVECTION WILL BE DURING THE AFTERNOON INTO EARLY EVENING
HOURS...WITH BULK OF CONVECTION EXITING THE CWA BY MIDNIGHT.
SUN-MON:
LARGE SCALE SUBSIDENCE BEHIND DEPARTING UPPER SYSTEM WILL ALLOW
SKIES TO CLEAR QUICKLY AT LEAST MID-MORNING SUNDAY. WEAK COLD AIR
ADVECTION BEHIND SURFACE COLD FRONT WILL KEEP TEMPERATURES
SLIGHTLY COOLER FOR SUNDAY...ESPECIALLY ACROSS EASTERN PART OF THE
CWA. TEMPERATURES WILL REBOUND ON MONDAY WITH WEAK DOWNSLOPE
WARMING. DRY CONDITIONS ARE EXPECTED.
TUE-THU:
BULK OF THE LONGER RANGE PORTION OF THE FORECAST APPEARS
QUIET. GEFS AND LONGER RANGE OPERATIONAL MODELS SHOWING SOME
DIFFLUENCE IN THE WED-THU TIME FRAME IN THE TIMING OF SHORT WAVE
FEATURE MOVING OUT OF WESTERN CANADA. APPEARS AREA WILL EXPERIENCE
THE PASSAGE OF ANOTHER COLD FRONT BY MID-WEEK...HOWEVER
PRECIPITATION CHANCES IN QUESTION. GULF WILL REMAIN SOMEWHAT
BLOCKED...SO ANY PRECIPITATION WILL BE CONCENTRATED IN PROXIMITY
OF UPPER DYNAMICS...WHICH SHOULD BE FOCUSED NORTH AND EAST OF
FORECAST AREA. HOWEVER...THERMODYNAMIC FORCING MAY ALLOW SCATTERED
CONVECTION TO DEVELOP ALONG FRONT...SO WILL MAINTAIN LOW CHANCE
POPS ACROSS MAINLY EASTERN CWA. TEMPERATURES SHOULD NO DEVIATE TOO
MUCH FROM NORMALS...THUS ACCEPTED GUIDANCE AS A WHOLE.
SF
PREV DISCUSSION... /ISSUED 1156 PM CDT FRI OCT 12 2012/
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE ANTICIPATED UPPER LEVEL LOW IS STILL MAKING ITS WAY INTO THE
HIGH PLAINS...BUT LIFT ASSOCIATED WITH IT IS ALREADY FORMING A
NICE LINE OF STORMS IN WESTERN KANSAS. THE STORY FOR MOST SITES
HAS BEEN IFR CONDITIONS WITH OCCASIONAL MVFR AND/OR LIFR. LOW
VISBYS AND CIGS APPEAR TO BE ON A KINGMAN TO SALINA LINE EXTENDING
TO THE NORTHWEST. BASIC EXPECTED TRENDS ARE FOR BANDS OF SHOWERS
AND THUNDERSTORMS TO PASS OVER THE CENTRAL KANSAS SITES NEAR AND
JUST BEFORE SUNRISE...THEN MOVE SLOWLY TO THE NORTH AND EAST AS
THE SURFACE LOW DEEPENS IN THE LEE OF THE ROCKIES. THIS SURFACE
LOW WILL TIGHTEN UP A DRY LINE AND MOVE EAST...AND DEPENDING ON
THE CLEARING BETWEEN THE MORNING CLOUDS AND PRECIP AND THE DRY
LINE...SHOULD FIRE NEW STORMS LATER SATURDAY AFTERNOON. THE AREAL
EXTENT OF THESE STORMS CAN`T BE PINNED DOWN YET...BUT IS EXPECTED
TO AFFECT ALL SITES EXCEPT FOR CNU...WHICH WILL SEE THE EFFECTS OF
THESE STORMS LATER IN THE EVENING. -LAUGEMAN
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 78 52 77 49 / 70 30 0 0
HUTCHINSON 79 51 78 48 / 60 30 0 0
NEWTON 77 51 77 49 / 60 30 0 0
ELDORADO 76 51 77 49 / 70 40 10 0
WINFIELD-KWLD 78 52 78 50 / 70 40 0 0
RUSSELL 79 48 77 46 / 40 30 0 0
GREAT BEND 80 49 77 47 / 50 20 0 0
SALINA 80 50 77 49 / 60 30 10 0
MCPHERSON 79 50 77 48 / 60 30 0 0
COFFEYVILLE 78 56 79 51 / 80 70 10 0
CHANUTE 76 54 77 50 / 80 70 10 0
IOLA 76 54 76 50 / 80 70 10 0
PARSONS-KPPF 77 54 78 50 / 80 80 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
648 AM CDT SAT OCT 13 2012
...UPDATE TO AVIATION...
.DISCUSSION...
WATER VAPOR IMAGERY SHOWING CENTER OF THE UPPER LOW JUST NORTH OF
THE FOUR CORNERS MOVING EASTWARD AS ANOTHER STRONG SHORTWAVE TROUGH
SWINGS EAST SOUTHEASTWARD AROUND THE SOUTHERN PORTIONS OF THE
TROUGH. CONVECTION HAS CONTINUED TO DEVELOP THROUGH THE NIGHT AHEAD
OF THE MAIN TROUGH THROUGH THE CENTRAL AND SOUTHERN HIGH PLAINS AS
IT MARCHES NORTHEASTWARD AND SLOWLY WEAKENS. MANY OF THE MODELS
ARE NOT HANDLING THIS EXPANSIVE AREA OF CONVECTION AND ITS
MOVEMENT..ALTHOUGH THE RAP IS DOING THE BEST AND INITIALLY HAVE
LEANED WITH ITS GRADUAL EASTWARD MOTION THROUGH THE MORNING WITH
ADDITIONAL DEVELOPMENT OUT AHEAD OF THIS INITIAL CONVECTION ACROSS
MUCH OF THE CENTRAL PORTIONS OF THE CWA THIS MORNING. RECENT RADAR
LOOPS ARE CONFIRMING MORE ELEVATED CONVECTION OUT AHEAD OF THE
LINE AND SOUTHWARD INTO OK. ALSO...NAM AND RECENTLY THE NEW EC
SUGGEST A SLOWER...DEEPER AND FURTHER SOUTH TRACK TO THE UPPER
TROUGH AS IT PROGRESSES ACROSS THE CWA LATE TODAY AND TONIGHT.
THIS COULD RESULT IN A MORE BACKED UPPER FLOW TODAY AND DELAY THE
EASTWARD PROGRESSION OF THIS MORNINGS CONVECTION AND MIDDAY
INSOLATION. ALL IN ALL...THIS COULD CREATE A CHALLENGE IN
FORECASTING THE DEGREE OF INSTABILITY AND RESULTING DEGREE OF THE
SEVERE THUNDERSTORM POTENTIAL ACROSS THE CWA THIS AFTERNOON INTO
THE EVENING. EITHER WAY...ELEVATED SHOWERS AND THUNDERSTORMS WILL
BE PREVALENT THIS MORNING WITH AN "EXPECTED" BREAK IN CONVECTION
BY MIDDAY FOLLOWED BY ADDITIONAL STRONGER DEVELOPMENT AHEAD OF THE
FRONT AND WITHIN INCREASING LARGE SCALE ASCENT AS A JET MAX ROUNDS
THE BASE OF THE UPPER TROUGH AS IT MOVES OUT INTO THE CENTRAL
PLAINS. WITH THE VERY STRONG SHEAR AND CAPE...ANY SUSTAINED
DISCRETE STORMS THAT ARE ABLE TO FORM THIS AFTERNOON MAY BE
CAPABLE OF PRODUCING LARGE HAIL...STRONG WINDS AND POSSIBLY AN
ISOLATED TORNADO PRIMARILY ACROSS NORTHEAST AND EAST CENTRAL AREAS.
HOWEVER...WITH THE ORIENTATION OF LARGE SCALE FORCING AND A MORE
PREDOMINANT UNIDIRECTIONAL FLOW...WOULD EXPECT STORMS TO FORM A
LINE OR LINE SEGMENTS WITH THE MAIN SEVERE POTENTIAL BEING VERY
STRONG STRAIGHTLINE WINDS. AGAIN...DEGREE OF INSTABILITY MAY BE
AFFECTED BY PRECIP COVERAGE AND CLOUD COVER. WITH INCREASING
PRECIPITABLE WATER VALUES APPROACHING AN INCH AND THREE
QUARTERS...LOCALLY HEAVY RAINFALL CAN ALSO BE EXPECTED IN SOME
AREAS. WITH THE SLOWER AND MORE SOUTHWARD TRACK OF THE
TROUGH...HAVE EXTENDED HIGHER POPS BEYOND MIDNIGHT TONIGHT...BUT
STILL ENDED BY SUNRISE ON SUNDAY. LOWERED HIGH TEMPS SLIGHTLY
TODAY THROUGH THE LOWER AND MIDDLE 70S AND AGAIN ON
SUNDAY...ESPECIALLY IN THE FAR EAST.
HAVE MAINTAINED A DRY FCST SUNDAY THROUGH TUESDAY WITH HIGHS IN THE
70S...THEN KEPT THE BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS
CENTERED ON WEDNESDAY AS THE NEXT COLD FRONT AND UPPER TROUGH MOVES
THROUGH THE NORTHERN PLAINS AND MIDWEST. WILL KEEP HIGHS BEHIND THE
FRONT IN THE 60S FOR THURSDAY AND FRIDAY...BUT STILL DRY AS MAIN
TROUGH SETS UP TO THE EAST IN THE MS AND OH RIVER VALLEYS. 63
&&
.AVIATION...
EXPECT IFR TO LOW MVFR CEILINGS THROUGH MUCH OF THE NEXT 24 HOURS.
THERE WILL BE PERIODS OF SHOWERS AND THUNDERSTORMS THROUGH THE
DAY AND INTO THE EVENING. SOME OF THE THUNDERSTORMS LATE THIS
AFTERNOON AND INTO THE EARLY EVENING HOURS MAY CONTAIN GUSTY
WINDS AND QUARTER SIZE HAIL.
GARGAN
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
634 AM CDT SAT OCT 13 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
306 AM CDT SAT OCT 13 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES THROUGH SUNDAY
AS WELL AS POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON AND EVENING.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED SPLIT FLOW ACROSS NORTH AMERICA. THE NORTHERN STREAM IS A
WEST-NORTHWEST FLOW FROM SOUTHWEST CANADA INTO NEW ENGLAND...WITH A
100 KT JET STREAK PRESENT OVER ONTARIO AT 200MB WITHIN THE FLOW. IN
THE SOUTHERN STREAM...AN UPPER LOW WAS PRESENT OVER WESTERN COLORADO
WITH A POTENT SHORTWAVE IN EASTERN ARIZONA...WHILE SUBTROPICAL
RIDGING WAS BUILDING AHEAD OF IT ACROSS MUCH OF THE MISSISSIPPI
RIVER VALLEY. 850MB PROFILER AND VWP DATA SHOWING SOUTH TO SOUTHWEST
WINDS OF 40-50 KT UNDER THE SUBTROPICAL RIDGE...HELPING TO ADVECT
GULF OF MEXICO MOISTURE TOWARDS THE FORECAST AREA. GOES DERIVED
PRECIPITABLE WATER SHOWED VALUES OF 1.3 INCHES APPROACHING NORTHEAST
IOWA WITH 1.5-1.7 INCH VALUES LURKING TO THE SOUTHWEST IN THE
KANSAS CITY AREA. SHOWER AND THUNDERSTORM DEVELOPMENT HAS BEEN
TAKING PLACE ON THE LEADING EDGE OF THIS MOISTURE SURGE ACROSS
WISCONSIN...AIDED TOO BY THE RIGHT ENTRANCE REGION OF THE NORTHERN
STREAM UPPER JET STREAK. ANOTHER SURGE OF MOISTURE LEADING TO
SHOWER AND THUNDERSTORM DEVELOPMENT OVER EASTERN NEBRASKA INTO
NORTHERN MISSOURI. AT THE SURFACE...A GENERAL LEE TROUGH WAS
PRESENT ALL UP AND DOWN THE WESTERN SIDE OF THE PLAINS...WITH A
RELATIVELY TIGHT PRESSURE GRADIENT PRESENT AHEAD OF THE TROUGH
EASTWARD ACROSS THE FORECAST AREA. THE COMBINATION OF INCREASING
CLOUDS AND WARM/MOIST ADVECTION ON THE SOUTHERLY BREEZE HAVE
HELPED TO BRING TEMPERATURES UP OVERNIGHT.
UPPER LEVEL PATTERN DISCUSSION...MODELS HAVE DEFINITELY TRENDED
FARTHER SOUTH AND SLOWER WITH THE UPPER LOW COMING OUT OF COLORADO
OVER THE PAST FEW DAYS. LATEST 13.00Z GUIDANCE...WHICH FOLLOWS A
SUGGESTION MADE BY THE 12.06Z NAM YESTERDAY...SUGGESTS THE UPPER LOW
IS GOING TO STAY MORE PHASED WITH THE POTENT SHORTWAVE COMING OUT OF
ARIZONA. AS A RESULT...THE UPPER LOW TAKES A TRACK ACROSS KANSAS
THIS AFTERNOON INTO TONIGHT...REACHING WESTERN MISSOURI BY 12Z
SUNDAY. AFTER 12Z SUNDAY...MODELS SPLIT INTO TWO CAMPS WITH THE
EJECTION NORTHEASTWARD OF THE UPPER LOW BY NORTHERN STREAM SHORTWAVE
TROUGHING DROPPING INTO THE NORTHERN PLAINS. THE 13.00Z
GFS/UKMET/CANADIAN/ECMWF TAKE A TRACK THROUGH CHICAGO INTO NORTHERN
LOWER MICHIGAN BY LATE SUNDAY...WHEREAS THE 13.00Z NAM AND 12.21Z
SREF MEAN HAVE A FARTHER SOUTHEAST TRACK TOWARDS TOLEDO OH. THESE
DIFFERENCES IN TRACKS ARE REFLECTED TOO AT THE SURFACE WITH THE
GFS/UKMET/CANADIAN/ECMWF DEPICTING THE ASSOCIATED SURFACE LOW GOING
FROM ST JOSEPH MO THROUGH MILWAUKEE AT 18Z SUNDAY...COMPARED TO THE
NAM/SREF HEADING THROUGH GARY INDIANA AT THE SAME TIME. THIS SETS UP
ISSUES WITH WHERE THE DEFORMATION BAND WILL IMPACT FOR THE TONIGHT
THROUGH SUNDAY TIME PERIOD...DISCUSSED BELOW. PLAN ON TAKING A
COMPROMISE APPROACH TO GIVE CREDIT TO THE NAM SUGGESTING A FARTHER
SOUTH TRACK WITH THE UPPER LOW TODAY.
TODAY...CURRENT AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS OVER
WESTERN WISCONSIN SHOULD KEEP PRESSING EAST THIS MORNING...AS IT IS
TIED TO THE LEADING EDGE OF 850MB MOISTURE TRANSPORT WHICH IS
PUSHING NORTHEAST. ADDITIONAL CONVECTIVE ACTIVITY LOOKS TO DEVELOP
SHORTLY OVER NORTHERN IOWA...AS SUGGESTED BY THE 13.00Z
NAM/CANADIAN/LOCAL WRF RUN...ASSOCIATED WITH THE NOSE OF A SECOND
MAXIMA OF 850MB MOISTURE TRANSPORT WITHIN THE MAIN MOISTURE
TRANSPORT ZONE. THIS COULD BE THE CURRENT CONVECTION SLIDING INTO
SOUTHWEST IOWA TOO ON THE LEADING EDGE OF HIGHER PRECIPITABLE
WATER. THE CONVECTIVE ACTIVITY WOULD SLIDE EAST ACROSS SOUTHERN
PORTIONS OF THE FORECAST AREA THIS MORNING. THUS...HIGHEST
PRECIPITATION CHANCES EXIST SOUTH OF I-90 THIS MORNING. DURING THE
AFTERNOON...PRECIPITATION SIGNALS ARE LESS CLEAR. ALL 850MB
MOISTURE TRANSPORT IS KIND OF POINTED AWAY FROM THE AREA...OR WE
ARE JUST UNDER THE STREAM WITH NO FOCUS AREAS. ALOFT AT
500MB...THERE REALLY IS NO FEATURE TO AID IN CONVECTIVE
DEVELOPMENT...AND IF ANYTHING WE ARE UNDER SOME WEAK SHORTWAVE
RIDGING AHEAD OF THE UPPER LOW. WE DO HAVE A WARM FRONTAL BOUNDARY
EXTENDING ACROSS NORTHERN IOWA INTO SOUTHERN WISCONSIN...WHICH
COMBINED WITH 500-1000 J/KG OF PROGGED MUCAPE COULD TRIGGER
CONVECTION. MODEL QPF FIELDS REFLECT THE LACK OF A PRECIPITATION
FOCUSING MECHANISM AS WELL. AS SUCH...HAVE KNOCKED PRECIPITATION
CHANCES DOWN INTO THE 50-70 RANGE FOR THE AFTERNOON. SHOULD
CONVECTION FIRE NEAR/ALONG THE WARM FRONT... 0-6KM...0-3KM AND
0-1KM SHEAR STILL SUPPORT POTENTIAL FOR SUPERCELLS AND LINE
SEGMENTS...WITH DAMAGING WIND AND TORNADOES POSSIBLE. THE SEVERE
CHANCES REALLY DEPEND ON IF WE CAN GET SOME SUN THIS AFTERNOON TO
HELP REACH THAT PROGGED INSTABILITY...WHICH IS HIGHLY UNCERTAIN
GIVEN THE STREAM OF CLOUDS WITHIN THE 850MB MOISTURE TRANSPORT
ZONE. GREATER CHANCES OF SEVERE WEATHER EXPECTED SOUTH OF THE
FORECAST AREA WHERE DYNAMICAL FORCING IS STRONGER. HIGH
TEMPERATURES ARE TRICKY TODAY. DID END UP COOLING THEM SOME DOWN
INTO THE 50S ALONG AND NORTHEAST OF I-94 WITH THE WARM FRONT
EXPECTED FARTHER SOUTH. ELSEWHERE...ADVECTION AND POTENTIAL FOR
SOME SLIGHT AMOUNT OF SUN SHOULD PUSH HIGHS INTO THE 60S AS
SUGGESTED BY MOST GUIDANCE. SHOULD MORE SUN OCCUR...850MB TEMPS OF
10-13C WOULD ALLOW READINGS TO TOP OUT WELL INTO THE 70S.
TONIGHT INTO SUNDAY...FOLLOWING THE COMPROMISE APPROACH MENTIONED IN
THE UPPER LEVEL DISCUSSION SECTION...WE SHOULD SEE A DEFORMATION
BAND OF PRECIPITATION FORM ON THE NORTH SIDE OF THE WARM FRONT THIS
EVENING. THIS BAND WOULD AFFECT THE SOUTHERN TWO-THIRDS OF THE AREA.
AS THE SURFACE LOW HEADS NORTHEAST INTO FAR SOUTHERN WISCONSIN
SUNDAY MORNING...ANTICIPATE THE BAND TO CONTINUE TO AFFECT THE SAME
AREA AND PERHAPS INTENSIFY AS THE LOW DEEPENS. DUE TO THE SLOWER
PROGRESS OF THE SYSTEM...HAVE HELD ONTO PRECIPITATION CHANCES
LONGER...WITH ONLY SOME OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA
DRYING OUT IN THE AFTERNOON. AN AREA SOUTHEAST OF A LINE FROM
DECORAH TO LA CROSSE AND BLACK RIVER FALLS STILL SEEMS POSSIBLE TO
PICK UP UPWARDS OF 1 TO 2 INCHES DURING THIS TIME PERIOD...
ESPECIALLY IF THE 13.00Z GFS/ECMWF PAN OUT. WITH MORE
CLOUDS/PRECIPITATION ON SUNDAY...COOLED HIGHS DOWN A BIT. MAY HAVE
TO LOWER MORE...AGAIN IF THE 13.00Z GFS/ECMWF PAN OUT. TONIGHTS
LOWS STILL SEEM REASONABLE WITH LITTLE CHANGE NEEDED.
SUNDAY NIGHT THROUGH MONDAY NIGHT...ATTENTION SHIFTS TO HOW QUICKLY
THE UPPER TROUGHING OVER THE FORECAST AREA...LEFT OVER BEHIND THE
STORM SYSTEM AND THE NEXT SHORTWAVE DROPPING INTO THE NORTHERN
PLAINS...SHIFTS OFF TO THE EAST. THE KICKING MECHANISM TO PUSH IT TO
THE EAST IS A SERIES OF SHORTWAVES DROPPING INTO MONTANA ON MONDAY.
THE 13.00Z NAM IS BY FAR THE FASTEST KICKING THE TROUGH OFF TO THE
EAST...RELATED TO THE SPEED OF THE STORM SYSTEM. THE OTHER SIDE OF
THE COIN IS THE 13.00Z GFS WHICH HANGS THE TROUGH UP OVER THE
EASTERN GREAT LAKES FOR MONDAY. THE ECMWF/UKMET LIE BETWEEN THE TWO
AND ARE PREFERRED. SKIES SHOULD GRADUALLY CLEAR SUNDAY NIGHT AS
SUBSIDENCE BUILDS IN BEHIND THE DEPARTING STORM SYSTEM AND HIGH
PRESSURE BUILDS IN AT THE SURFACE. DEPENDING ON THE SPEED OF
CLEARING...COULD SEE LOWS DIP BELOW FREEZING...ESPECIALLY AT THE
TYPICAL COLD SPOTS. DECENT WARMING OCCURS MONDAY...THOUGH...AS THE
SURFACE RIDGE HEADS EAST. 850MB TEMPS COULD POP UP TO 7-11C BY 00Z
TUESDAY. PREVIOUS FORECAST HIGHS HAVE THE WARMING HANDLED WELL.
WARMER NIGHT ON TAP MONDAY NIGHT WITH A RELATIVELY TIGHT PRESSURE
GRADIENT IN PLACE AHEAD OF THE MONTANA SHORTWAVES DROPPING INTO THE
DAKOTAS. NO PRECIPITATION ANTICIPATED WITH A DRY AIRMASS IN PLACE
AND THE BEST FORCING SITUATED NORTH OF THE AREA.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
306 AM CDT SAT OCT 13 2012
GENERAL THEME CONTINUES WITH THE 13.00Z GFS/ECMWF/CANADIAN AND GFS
ENSEMBLES OF DEEP TROUGHING DEVELOPING OVER THE NORTHERN PLAINS AND
UPPER MISSISSIPPI RIVER VALLEY REGION BY THURSDAY. HOWEVER...THE WAY
WE GET THERE IS SLIGHTLY DIFFERENT NOW. AT 12Z TUESDAY...MODELS
DEPICT A POTENT SHORTWAVE COMING INTO SOUTHERN BRITISH COLUMBIA WITH
A 140 KT JET AT 250MB ON ITS SOUTH SIDE. THE SHORTWAVE THEN DIGS
DOWN INTO THE NORTHERN PLAINS WITH ALL MODELS SHOWING UPPER LOW
DEVELOPMENT...PERHAPS AS EARLY AS WEDNESDAY. PRIOR TO THE UPPER LOW
ARRIVAL...THERE IS THOSE SHORTWAVES THAT WERE MOVING INTO THE
DAKOTAS AT 12Z TUESDAY. THESE END UP COMING ACROSS THE FORECAST AREA
TUESDAY NIGHT. ALTHOUGH THE AIRMASS IS SOMEWHAT DRY...THE FORCING
FROM THE WAVE...ESPECIALLY ACROSS NORTHERN PORTIONS OF THE
AREA...MAY BE STRONG ENOUGH TO OVERCOME THE DRY AIR AND RESULT IN
SOME LIGHT PRECIPITATION. NEXT CHANCE OF RAIN COMES WEDNESDAY AS
MOISTURE TRANSPORT AND DPVA INCREASE AHEAD OF THE DEVELOPING UPPER
LOW. THESE CHANCES MAY NEED TO BE RAISED IN FUTURE FORECASTS IF
TRENDS CONTINUE ON THE UPPER LOW DEVELOPMENT. THIS UPPER LOW THEN
SHIFTS INTO THE FORECAST AREA...BRINGING IN COOLER AIR AND LIKELY
MORE SHOWER ACTIVITY. MODELS THEN DIVERGE WITH HOW FAST THE UPPER
LOW LEAVES THE AREA FOR THE END OF THE WEEK. THE ECMWF SUGGESTS IT
GETS CUT OFF DUE TO BUILDING RIDGING ALONG THE EASTERN SEABOARD AND
IN THE WESTERN U.S.. THIS SCENARIO WOULD RESULT IN COOL...SHOWERY
DAYS AND NIGHTS. THE GFS AND MAJORITY OF ITS ENSEMBLES MEMBERS
SUGGEST A SLOW PROGRESSION NORTHEASTWARD...ALLOWING FOR DRYING
CONDITIONS TO COME IN FOR FRIDAY. TAKING THE CONSENSUS APPROACH FOR
NOW WITH 20-30 PERCENT CHANCES. COOL WEATHER STILL LOOKS REASONABLE
EVEN IN THE GFS CAMP AS 850MB TEMPS FALL TO 0-2C.
&&
.AVIATION...TODAY AND TONIGHT
634 AM CDT SAT OCT 13 2012
IFR/MVFR CONDITIONS ARE EXPECTED AT THE TAF SITES TODAY INTO
TONIGHT. A WARM FRONT WILL LIFT INTO NORTHEAST IOWA AND SOUTHWEST
WISCONSIN TODAY. SHOWERS AND SCATTERED THUNDERSTORMS WILL IMPACT
THE AREA TODAY INTO TONIGHT AS THE WARM FRONT STALLS NEAR THE
INTERSTATE 90 CORRIDOR AND A STRONG LOW PRESSURE SYSTEM OVER THE
CENTRAL PLAINS LIFTS NORTHEAST INTO THE UPPER MISSISSIPPI RIVER
VALLEY. LOW STRATUS WILL BRING IFR/MVFR CONDITIONS TO THE TAF
SITES. BRIEF LIFR CONDITIONS ARE POSSIBLE THIS MORNING AT KRST WITH
CLOUD BASES AROUND 400 FT. CLOUD BASES ARE EXPECTED TO BE AROUND
1000 FT AT KLSE THIS MORNING. CEILINGS SHOULD RISE SLIGHTLY THIS
AFTERNOON TO AROUND 1500FT. FORECAST SOUNDINGS SHOW THE POTENTIAL
FOR IFR/LIFR CONDITIONS IN LOW STRATUS AND FOG THIS EVENING INTO
THE OVERNIGHT HOURS. PLAN ON CEILINGS FALLING TO AROUND 900FT AT
KLSE BY 3Z...AND FALLING TO AROUND 500FT AT KRST BY 08Z. IN
ADDITION...FOG COULD REDUCE VISIBILITIES TO 4SM OR LESS AT KRST
TONIGHT AS EASTERLY UPSLOPE WINDS ADVECT LOW STRATUS INTO THE TAF
SITE.
&&
.HYDROLOGY...THROUGH SUNDAY
306 AM CDT SAT OCT 12 2012
QPF FORECAST STILL PROBLEMATIC...AGAIN DUE TO THE TRACK OF THE
STORM SYSTEM. MAIN FOCUS IS GOING TO BE ON THE DEFORMATION BAND ON
THE NORTH SIDE OF THE STORM SYSTEM TRACK...SINCE THIS IS GOING TO
HAVE THE BULK OF THE HEAVIER RAIN. THE LATEST 13.00Z ECMWF PROGS
A BAND OF 3-3.5 INCHES FROM PRAIRIE DU CHEIN NORTHEAST TOWARDS
WISCONSIN RAPIDS. THE 13.00Z GFS IS NOT TOO FAR OFF WITH A SIMILAR
BAND OF 2-4 INCHES IN ABOUT THE SAME PLACE. ON THE OTHER
HAND...THE FARTHER SOUTH AND FASTER 13.00Z NAM ENDS UP PRODUCING
THE HEAVY RAIN BAND ACROSS MUCH OF NORTHERN ILLINOIS. HAVE TAKEN A
COMPROMISE APPROACH BETWEEN THE TWO SCENARIOS...RESULTING IN AN
AREA OF 2 INCHES ACROSS THE SOUTHEASTERN 1/3 OF THE FORECAST AREA.
WILL HAVE TO SEE EVENTUALLY WHERE THE DEFORMATION BAND SETS UP TO
DETERMINE WHICH SCENARIO TO FOLLOW. NEEDLESS TO SAY...THE
LANDSCAPE AND RIVERS REALLY COULD USE THIS RAIN GIVEN THE SEVERE
TO EXTREME DROUGHT CONDITIONS IN PLACE. THEREFORE...NO FLOODING IS
ANTICIPATED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
306 AM CDT SAT OCT 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS MIAMI FL
145 PM EDT SAT OCT 13 2012
.AVIATION...
ISOLATED SHRAS HAVE PUSHED WELL INLAND AND AWAY FROM THE EAST
COAST TERMINALS AS NORTHEAST WINDS HAVE BECOME GUSTY. BELIEVE ANY
FURTHER SHRA ACTIVITY WILL NOT RESTRICT ANY OF THE TERMINALS.
SLIGHTLY DEEPER MOISTURE WILL BEGIN TO POOL INTO THE SOUTH FLORIDA
AREA TOWARD THE END OF THE TAF PERIOD DUE TO REMNANTS FROM PATTY.
LEFT ANY MENTION OF VCSH OUT OF TAFS FOR NOW. IN THE MEAN TIME,
NORTHEAST TO EAST-NORTHEAST FLOW WILL DOMINATE.
&&
.PREV DISCUSSION... /ISSUED 1051 AM EDT SAT OCT 13 2012/
UPDATE...
NO MAJOR UPDATES ARE ANTICIPATED THIS MORNING AS THE PREVIOUS
FORECAST PACKAGE REMAINS ON TRACK. WE DID SLIGHTLY ADJUST TO
GRIDDED TEMPERATURE DATABASE BASED ON THE LATEST OBSERVATIONS THIS
MORNING...WHICH WERE RUNNING SLIGHTLY COOLER INLAND THAN WHAT WAS
FORECAST. THE LATEST RADAR LOOP SHOWED ISOLATED TO SCATTERED
SHOWERS SPREADING ASHORE ALONG PORTIONS OF THE EAST COAST AREAS
WITHIN THE BREEZY NE FLOW. THE LATEST HRRR MODEL REFLECTIVITIES
INITIALIZED WELL WITH THIS PATTERN AND SHOWED A SIMILAR TREND
CONTINUING THROUGH THE REMAINDER OF THE DAY. 85/AG
PREV DISCUSSION... /ISSUED 733 AM EDT SAT OCT 13 2012/
AVIATION...
STRONG NORTHEAST FLOW WILL CONTINUE TO BUILD INTO THE
REGION THIS MORNING AND IS EXPECTED TO PERSIST THROUGH THE DAY.
STRATOCUMULUS IN THE 3 KFT TO 6 KFT RANGE WITH EMBEDDED SHOWERS WILL
CONTINUE TO STREAM SOUTHWEST ACROSS THE ATLANTIC WATERS WITH THE
EAST COAST TAF SITES EXPERIENCING BRIEF PASSING SHOWERS FROM TIME TO
TIME WITH GUSTS TO NEAR 30 KNOTS OCCASIONALLY WITH A PASSING SHOWER
WITH VERY BRIEF SUB-VFR CONDITIONS POSSIBLE.
PREV DISCUSSION... /ISSUED 452 AM EDT SAT OCT 13 2012/
UPDATE...SHOWERS HAVE INCREASED IN COVERAGE ACROSS THE ATLANTIC
WATERS AND IR SATELLITE IMAGERY SHOWS A BAND OF MOISTURE EXTENDING
ACROSS GRAND BAHAMA AND TO THE NORTH WITH MOVEMENT TOWARDS SOUTH
FLORIDA. GIVEN THIS CURRENT TREND, HAVE UPDATED THE POPS INTO THE
SCATTERED CATEGORY FOR THE INTERIOR/EAST COAST TODAY ALONG WITH
INCREASING SKY COVER AS WELL. /GREGORIA
PREV DISCUSSION... /ISSUED 319 AM EDT SAT OCT 13 2012/
WINDY THIS WEEKEND WITH A HIGH RISK OF RIP CURRENTS ATLANTIC COAST...
FEW FAST MOVING SHOWERS EXPECTED, FOCUSED EAST COAST, BECOMING
SCATTERED SUNDAY WITH A SLIGHT CHANCE OF THUNDERSTORMS...
DISCUSSION...
THE PRESSURE GRADIENT WILL CONTINUE TIGHT ACROSS SOUTH FLORIDA
THROUGH SUNDAY, DUE TO STRONG HIGH PRESSURE OVER THE MID ATLANTIC
STATES AND T.D. PATTY EAST OF THE BAHAMAS, WHICH IS FORECAST BY NHC
TO DISSIPATE INTO A REMNANT LOW BY THIS EVENING WHILE MOVING SW. THE
RESULT ACROSS SOUTH FL WILL BE WINDY CONDITIONS THROUGH SUNDAY,
ESPECIALLY ALONG THE ATLANTIC COAST, ALONG WITH INCREASING MOISTURE
FROM THE EAST. AS THE REMNANTS OF PATTY MOVE OVER THE STRAITS AND
CUBA SUN-MON, MOISTURE WILL CONTINUE TO INCREASE WELL NORTH OF THIS
FEATURE. THE PWAT IS FORECAST TO INCREASE FROM AROUND AN INCH NOW TO
1.6-1.8" BY SUN AFTERNOON. THIS WILL LEAD TO A BETTER CHANCE OF FAST
MOVING SHOWERS SUN-SUN NIGHT. FORECAST SOUNDINGS SHOW THE CAP IN
PLACE NOW ERODING WITH MORE INSTABILITY, SO CANNOT RULE OUT A TSTORM
OR TWO AS WELL SO PLACED A SLIGHT CHANCE IN THE FORECAST SUN-MON.
STRONG RIP CURRENTS ARE LIKELY ALONG THE ATLANTIC BEACHES THROUGH
THE WEEKEND. MINOR COASTAL FLOODING WILL BE POSSIBLE IN THE MORE
VULNERABLE LOCALES ALONG THE ATLANTIC COAST, DUE TO A COMBINATION OF
HIGHER THAN NORMAL TIDES AND THE STRONG ONSHORE WIND FLOW. WILL
CONTINUE TO HIGHLIGHT THIS, ESPECIALLY THE RIPS WHICH ARE THE
BIGGEST THREAT.
WINDS BEGIN TO WEAKEN SUN NIGHT-MON AS THE ATLANTIC HIGH MOVES EAST.
BOTH GFS/ECMWF SHOW A SHORTWAVE TROUGH MOVING ACROSS THE EASTERN
STATES MON NIGHT-TUE. THIS IS FORECAST TO TAKE T.S. RAFAEL, NOW OVER
THE EASTERN CARIBBEAN, ON A NNW TRACK THEN RECURVING OUT TO SEA
TOWARDS BERMUDA AS PER NHC. LOCALLY, A WEAKENING COLD FRONTAL
BOUNDARY WILL MOVE INTO SOUTH FL MON NIGHT AND MOVE JUST SOUTH OF
THE AREA TUE-WED WITH HIGH PRESSURE RE-BUILDING TO THE NORTH. THIS
WILL LEAD TO A DECREASING MOISTURE TREND SO WILL CONTINUE WITH LOW
POPS THIS PERIOD. SO THE MID/LATE PERIOD NEXT WEEK LOOKS RATHER
TRANQUIL WITH NO MAJOR WEATHER SYSTEMS EXPECTED. HUMIDITY WILL
GRADUALLY INCREASE OVER THE NEXT FEW DAYS BUT IT NEVER GETS OUT OF
HAND.
LOOKING WAY OUT INTO THE EXTENDED FOR NEXT WEEKEND - ECWMF AND GFS
BOTH SHOW A DEEPENING MID/UPPER CLOSED LOW MOVING FROM THE GREAT
LAKE TO NEW ENGLAND. THE 12.12Z ECMWF AMPLIFIED THE TROUGH,
SENDING A STRONG COLD FRONT ACROSS SOUTH FL WITH DEWPOINTS FALLING
INTO THE 40S AND 50S! HOWEVER, THE LATEST ECMWF RUN IS NOT AS
STRONG AND THE LATEST GFS RUN IS NOT AS AGGRESSIVE WITH THE
TROUGH, BRINGING A COLD FRONT THROUGH BRIEFLY NEXT WEEKEND WITH A
QUICK TURN OF THE WINDS TO THE NORTHEAST, KEEPING CONDITIONS WARM
AND RATHER HUMID. NO SIGNIFICANT WEATHER IS EXPECTED THROUGH THE
PERIOD.
MARINE...OBS SHOW SUSTAINED WINDS NEAR 20 KT ACROSS THE WATERS.
WILL CONTINUE THE SMALL CRAFT ADVISORY FOR THE ATLANTIC, BISCAYNE
BAY AND THE LAKE...AND ADD THE OFFSHORE GULF WATERS AS WELL. WINDS
WILL STAY UP THROUGH TONIGHT THEN BEGIN TO GRADUALLY SUBSIDE SUN-
MON. SEAS WILL CONTINUE AT 7 FT OR HIGHER ACROSS THE ATLANTIC
THROUGH SUNDAY BEFORE GRADUALLY SUBSIDING.
FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN WELL
ABOVE CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 78 87 76 87 / 20 40 30 30
FORT LAUDERDALE 78 88 79 87 / 20 40 40 30
MIAMI 79 88 77 88 / 20 40 40 30
NAPLES 72 90 75 89 / 10 30 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH SUNDAY EVENING FOR COASTAL BROWARD-
COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR BISCAYNE BAY-
LAKE OKEECHOBEE.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT SUNDAY FOR COASTAL WATERS
FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-COASTAL
WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING
FROM 20 NM TO THE TERRITORIAL WATERS OF THE BAHAMAS-WATERS
FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20
NM TO 60 NM.
GM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR GULF WATERS FROM
CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING FROM 20 TO 60 NM.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1235 PM CDT SAT OCT 13 2012
.DISCUSSION...
ISSUED 1030 AM CDT SAT OCT 13 2012
ELEVATED SHOWERS AND THUNDERSTORMS WERE WIDESPREAD ACROSS THE
NORTHERN HALF OF ILLINOIS AT 10 AM. WILL CONTINUE TO SEE THAT
SPREAD EASTWARD THE REMAINDER OF THE MORNING...BEFORE A BREAK IN
THE RAIN OCCURS EARLY THIS AFTERNOON. MAIN QUESTION WILL BE HOW
MUCH RENEWED INSTABILITY CAN DEVELOP THIS AFTERNOON. TEMPERATURES
CURRENTLY ONLY IN THE 50S OVER ALMOST ALL THE CWA EXCEPT THE
EXTREME SOUTHEAST. LOW CLOUDS WERE EXTENSIVE WESTWARD ALL THE WAY
INTO KANSAS...ALTHOUGH RECENT VISIBLE SATELLITE IMAGERY SHOWING
SOME SIZABLE BREAKS DEVELOPING IN CENTRAL MISSOURI. LATEST RAP...
HRRR AND NAM SHOWING SHOWERS AND STORMS CURRENTLY IN NORTHWEST
MISSOURI AND EASTERN KANSAS ADVECTING NORTHEAST...WITH SOME
ADDITIONAL REDEVELOPING OVER NORTHERN MISSOURI THIS AFTERNOON
BEFORE MOVING INTO ILLINOIS.
UPDATED ZONES/GRIDS WERE SENT ABOUT A HALF HOUR AGO TO ADDRESS THE
LATEST RAIN AND TEMPERATURE TRENDS. WILL NEED TO MONITOR
TEMPERATURES CLOSELY...AS THE RAIN AND EXTENSIVE CLOUD COVER WILL
LIKELY PREVENT ANY RAPID WARM UPS. TEMPERATURES WERE LOWERED BY A
FEW DEGREES IN THE RECENT UPDATE.
GEELHART
&&
.AVIATION...
ISSUED 1235 PM CDT SAT OCT 13 2012
COMPLICATED TAF FORECAST FOR THIS PERIOD. WIDESPREAD MVFR/IFR
CONDITIONS OVER THE TAF SITES AT MIDDAY...WESTWARD ACROSS
MISSOURI...ALTHOUGH SURFACE OBS AND SATELLITE SHOWING SOME
THINNING CLOUDS AND VFR CEILINGS WEST OF KSPI. FORECAST SOUNDINGS
TRYING TO SHOW SOME GRADUAL IMPROVEMENT BY MID TO LATE
AFTERNOON...BUT INVERSION AROUND 2000 FEET MAY BE DIFFICULT TO
OVERCOME IN SOME AREAS. WIDESPREAD SHOWERS AND EMBEDDED
THUNDERSTORMS CONTINUE TO PUSH THROUGH THE AREA...BUT A COUPLE
HOUR BREAK AROUND KPIA/KSPI IS LIKELY BETWEEN THE INITIAL BLOB
OF RAIN AND A LINE OF RAIN EXPANDING FROM SOUTHWEST MISSOURI INTO
EASTERN IOWA. AT THE EASTERN TAF SITES...A MORE EXTENDED BREAK IS
EXPECTED THIS EVENING...WITH RETURN OF RAIN AND MVFR CEILINGS
DEVELOPING AFTER 06Z.
AS STRENGTHENING LOW PRESSURE MOVES ACROSS NORTHWEST ILLINOIS ON
SUNDAY MORNING...SOUTHWEST WINDS WILL RAMP UP...AND GUSTS SHOULD
BE APPROACHING 25-30 KNOTS BY LATE MORNING. LINGERING
SHOWERS/STORMS SHOULD DIMINISH TO SCATTERED ACTIVITY AS A DRY SLOT
STARTS TO WRAP AROUND THE LOW.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 327 AM CDT SAT OCT 13 2012
SHORT TERM...TODAY THROUGH SUNDAY
MAIN CONCERNS THIS FORECAST PERIOD WILL BE ANTICIPATED CONVECTION
AND ANY ASSOCIATED STRONG/SEVERE STORMS AND HEAVY RAINFALL.
ELEVATED CONVECTION WAS ONGOING IN NORTHERN IL...AS WELL AS
NORTHERN AND CENTRAL MO. THIS WAS ASSOCIATED WITH LOWER LEVEL WARM
AIR ADVECTION/ISENTROPIC LIFT. THE GFS 300K SURFACE INDICATED THAT
THIS WILL CONTINUE THROUGH MUCH OF THE MORNING IN NORTHERN AND
CENTRAL IL. THE HRRR MODEL CONCURS THAT PERIODS OF SHOWERS AND
T-STORMS CAN BE EXPECTED THIS MORNING... ESPECIALLY ALONG AND
NORTH OF A TAYLORVILLE- DANVILLE LINE.
HIGH TEMPERATURES...AND PARTICULARLY SFC BASED INSTABILITY...WILL BE
CHALLENGING BECAUSE OF CONVECTIVE DEBRIS AS WELL AS PLENTY OF LOW
LEVEL MOISTURE AND AN INVERSION ON FORECAST SOUNDINGS UNTIL LATE
THIS AFTERNOON IN CENTRAL IL. WILL KNOCK DOWN HIGH TEMPS IN CENTRAL
IL AS A RESULT...BUT KEEP WARMER READINGS IN THE SOUTHEAST.
DESPITE MARGINAL INSTABILITY IN MOST AREAS THIS EVENING...INCREASING
UPPER LEVEL DIVERGENCE AHEAD OF AN UPPER LOW IN NORTHEAST KS ALONG
WITH 30-40KTS OF BULK SHEAR WILL RESULT IN A DEVELOPING LINE OF
STORMS APPROACHING WEST CENTRAL IL LATE THIS EVENING.
UNIDIRECTIONAL FLOW ALOFT AND INCREASING LOW LEVEL WINDS BELOW
850 MB COULD RESULT IN GUSTY WINDS WITH THE STRONGEST STORMS.
WITH EACH SUCCESSIVE MODEL RUN A BIT SLOWER...AM NOT EXPECTING THE
T-STORMS TO REACH EXTREME EAST AND SOUTHEAST IL UNTIL VERY LATE
TONIGHT. EXPECT SHOWERS AND ISOLATED T-STORMS TO LINGER IN
CENTRAL IL MUCH OF THE DAY SUNDAY AHEAD OF THE UPPER LEVEL TROUGH
AXIS...BEFORE DEPARTING THE STATE LATE SUNDAY NIGHT.
LONG TERM...MONDAY THROUGH FRIDAY
A SEMI-ZONAL FLOW WILL DEVELOP AFTER THE UPPER LEVEL TROF
DEAMPLIFIES AND LIFTS THROUGH THE NEW ENGLAND STATES LATER MONDAY
AND TUESDAY. THIS WILL RESULT IN TEMPERATURES CLOSE TO SEASONAL
NORMALS FOR MID-OCTOBER.
THE NEXT CHANCE FOR PRECIPITATION IS EXPECTED LATE TUESDAY
NIGHT...BUT PARTICULARLY WEDNESDAY AS AN UPPER LEVEL TROUGH FROM
THE PACIFIC NORTHWEST CROSSES INTO THE NORTHERN PLAINS AND DEEPENS
IN THE UPPER MIDWEST. THERE IS CONSIDERABLE MODEL UNCERTAINTY AT
THIS POINT WITH THE SPEED OF THE SYSTEM AND JUST HOW FAR SOUTH THE
UPPER LEVEL LOW WILL DEVELOP AND HOW STRONG IT WILL BE. FOR NOW
WILL GO WITH SHOWERS AND A FEW T-STORMS AHEAD OF THE SURFACE COLD
FRONT WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY SOMEWHAT COOLER
TEMPERATURES IN THE LOWER TO MIDDLE 60S.
WILL NEED TO KEEP AN EYE ON THIS SYSTEM BECAUSE IF THE UPPER LOW
SETTLES OVER THE MIDWEST THEN TEMPERATURES WILL BE QUITE CHILLY
WITH RAINY CONDITIONS FOR FRIDAY AND BEYOND.
MILLER
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1243 PM CDT SAT OCT 13 2012
.UPDATE 13/18Z AVIATION DISCUSSION...
.SHORT TERM FORECAST /TODAY/...
FIRST MCS TIED TO STRONG THETAE ADVECTION NOW EAST OF THE AREA WITH
NEXT ROUND OF WARM AIR ADVECTION STORMS HEADING NORTHEAST INTO
SOUTHEAST SECTIONS. FOR NOW...INSTABILITY REMAINS LOW AT THIS TIME
AND MAIN WAVE OVER NEW MEXICO THIS MORNING NOW TURNING NORTH INTO
WESTERN KS/OK/TX AT THIS TIME. THOUGH COLD FRONT REMAINS FAR
NORTHWEST AT THIS TIME...ANOTHER WARM FRONT OVER EASTERN KS/NEBRASKA
WILL MOVE NORTHEAST LATE THIS AFTERNOON AND SHOULD BRING THE
SOUTHERN SECTIONS INTO THE WARM SECTOR AS INSTABILITY INCREASES BY
LATE AFTERNOON. MAIN CONCERNS REMAIN THE SOUTHEAST WHICH SHOULD SEE
BETTER CHANCES FOR SEVERE THIS AFTERNOON AND EVENING HOURS AS THE
SFC LOW CONSOLIDATES AND HEADS INTO NORTHEAST KS/NORTHWEST MO BY
00Z. STRONGER UPPER LEVEL WIND FIELDS REMAIN SOUTH AND EAST OF
FORECAST AREA THIS AFTERNOON...BUT ENOUGH SHEAR STILL EXISTS FOR
SEVERE STORM POTENTIAL. HAVE TRIMMED SEVERE CHANCES BACK TO AFT 21Z
WITH LESSER CHANCES FOR THUNDER MOST AREAS THIS AFTERNOON WITH THE
EXCEPTION OF THE SOUTHEAST WHERE NEXT AREA OF STORMS CURRENTLY OVER
MO WILL IMPACT REGION YET BEFORE 21Z. HIGHS LOOK SLIGHTLY COOLER
NORTH AND HAVE REDUCED HIGHS THERE BY A FEW DEGREES AS WELL.
.PREVIOUS SHORT TERM /TODAY/...
MAIN CONCERN THIS MORNING IS OBVIOUSLY CONVECTIVE TRENDS. LONG WAVE
TROUGH CONTINUES TO MOVE ACROSS THE ROCKIES WITH ASSOCIATED WARM
FRONT FROM WY/SD SURFACE LOW THROUGH MO VALLEY. RAP ANALYSIS
APPEARS TO BE HANDLING CURRENT WEATHER WELL SHOWING INTENSIFYING
THETA-E ADVECTION COINCIDENT WITH NARROW NW-SE MCS FROM NE INTO MO.
REMNANT MCS THAT FORMED NEAR PARENT UPPER LOW IN THE ROCKIES
CONTINUES TO ADVANCE ACROSS KS INTO NE...MERGING WITH WARM ADVECTION
CONVECTION. RAP 300-310K ISENT LAYER ROOTED AT TOP OF INVERSION
ADVANCES THIS MCS INTO IA AND MATURES IT THROUGH THE MORNING WITH
STRONG MOISTURE TRANSPORT. ELEVATED CAPES APPEAR TO BE AROUND 1000
J/KG WITH MARGINAL EFFECTIVE SHEAR UPSTREAM INTO IMMEDIATE MO RIVER
VALLEY. HOWEVER ESTIMATED RAP EFFECTIVE SHEAR /1-6KM/ WANES SO
REALLY DO NOT EXPECT MUCH IN THE WAY OF SEVERE WEATHER THIS
MORNING...JUST MUCH NEEDED RAIN. THE LATEST HRRR SUPPORTS THIS AS
WELL AND SEEMS TO BE CLOSER TO REALITY...UNLIKE MOST WRF RUNS...SO
WIDESPREAD CATEGORICAL POPS HAVE BEEN INCLUDED.
QUESTION BY THIS AFTERNOON TURNS TO SEVERE WEATHER POTENTIAL ALONG
WITH LESS CONFIDENCE. 60F PLUS DEWPOINTS CURRENTLY NOTED SOUTH OF
WARM FRONT ACROSS KS SHOULD ENTER IA BY THIS AFTERNOON RESULTING IN
MAX MLCAPES AROUND 1500 J/KG AND LITTLE CINH. THIS THERMODYNAMIC
ENVIRONMENT WOULD BE COINCIDENT WITH FAVORABLE DEEP SHEAR FOR
SUPERCELLS AND SHALLOW SHEAR FOR A FEW TORNADOES...ESPECIALLY S
CENTRAL/SE LATE. AGREE WITH SPC LOW TOR PROBS SOUTH BECAUSE OF
THIS...BUT UNIDIRECTIONAL S/SWLY FLOW IS NOT TOO CONDUCIVE.
HOWEVER ANOTHER QUESTION WILL BE INITIATION OR SOURCE. FRONTAL
SYSTEM AND CONVERGENCE WILL LAG THIS AREA CONSIDERABLY...STILL BACK
INTO KS/NE/NWRN IA BY 00Z...AS IS STRONGER H7/H5 FORCING IMMEDIATELY
AHEAD OF PARENT LOW. MINOR WAVES AND H85/H7 FORCING EJECTING OUT IN
SWLY UPPER FLOW COULD FORM ANOTHER MCS...OR REMNANTS FROM SRN TAIL
END OF CURRENT KS CONVECTION COULD EVENTUALLY REACH IA. HOWEVER
THIS DEVELOPMENTAL UNCERTAINTY...AND THE POTENTIAL THAT MORNING MCS
COULD HINDER THE THERMODYNAMIC ENVIRONMENT...HAS MADE THIS SEVERE
WEATHER CONDITIONAL AND LESS CERTAIN. MANY MODELS STILL DEVELOP
SOMETHING FROM THE SOUTH INTO SRN IA HOWEVER SO ALTHOUGH DETAILS NOT
CLEAR...HAVE INTRODUCED SEVERE WORDING SOUTH.
REGARDLESS OF PRECIP TRENDS...AIRMASS SHOULD FEEL SUMMERLIKE WITH
MODEL CONSENSUS PUSHING HIGHS INTO THE 70S AND DEWPOINTS INTO THE
60S. RAW MODEL TEMPS AND MOS GUIDANCE ALL SEEM TO BE IN AGREEMENT
ON THIS.
.LONG TERM /TONIGHT THRU FRIDAY/...
MODELS HAVE COME TOGETHER FOR THE MOST PART WITH THE TIMING AND
EVOLUTION OF THE LOW THIS EVENING. SURFACE LOW WILL TRACK ACROSS
IOWA...MOST LIKELY THE SOUTH HALF...THIS EVENING AND KEPT A SHORT
WINDOW FOR POTENTIAL SEVERE. THAT WILL BE OUT OF THE PICTURE BY
03Z. CHANGE IN THE EVOLUTION FROM PREVIOUS RUNS IS THE TRACK A BIT
FARTHER SOUTH...RESULTING IN A DECENT DEFORMATION ZONE CROSSING IOWA
TONIGHT AND LINGERING WELL IN TO SUNDAY MORNING. MADE ADJUSTMENTS
TO COVER THAT BOTH WITH INCREASING POPS AS WELL AS LOWERING MAX
TEMPS FOR SUN. THE NEXT WEATHER SYSTEM IS SLATED TO ARRIVE MID
WEEK. A BIG DIFFERENCE BETWEEN THE GEM AND ECMWF SOLUTIONS AND THE
GFS WITH THE DEEPENING OF THE UPPER LOW. GEM AND EC BOTH SUGGEST
COOLER AND WETTER WEATHER IS IN STORE. CURRENTLY...PRECIP IS IN FOR
THE WED TIME FRAME. KEPT IT IN THE NERN ZONES FOR THE LATER PART OF
THE WEEK...BUT MAY HAVE TO BE ADJUSTED FARTHER SOUTH AND WEST WITH
LATER PACKAGES. WITH THE SYSTEM DURING MID WEEK BEING FROM THE
NORTHERN STREAM INSTEAD OF THE SOUTHERN BRANCH...DON`T SEE THE
THUNDER THREAT AS BEING A BIG DEAL.
&&
.AVIATION...13/18Z
CONTINUE TO DEAL WITH MVFR AND IFR CIGS THIS AFTERNOON WITH SOME
LIFTING OF CEILINGS OVER WESTERN AND CENTRAL SECTIONS AS WARM FRONT
LIFTS NORTH. INSTABILITY TO INCREASE WITH SOME INSOLATION TODAY AND
HAVE INTRODUCED THUNDER AGAIN INTO THE SOUTH TAFS BY LATE AFTERNOON
AND WILL CONTINUE THROUGH NEAR 12Z AS LOW SLOWLY MOVES EAST WITH
TIME. SOME QUESTIONS REGARDING COVERAGE AND TIMING AS MAIN WAVE WILL
ARRIVE BY LATE AFTERNOON AND EARLY EVENING. WINDS TO REMAIN SOUTH
UNTIL FRONT ARRIVES LATE TONIGHT AND EARLY MORNING. WINDS BECOME NW
BETWEEN 09-13Z AND INCREASE THROUGH THE MORNING HOURS. CIGS WILL
SLOWLY IMPROVE TOWARD END OF PERIOD FROM THE NW TO THE SOUTHEAST.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
AVIATION...SMALL
LONG TERM...MS OCT 12
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1132 AM CDT SAT OCT 13 2012
.UPDATE PUBLIC DISCUSSION...
.SHORT TERM FORECAST /TODAY/...
FIRST MCS TIED TO STRONG THETAE ADVECTION NOW EAST OF THE AREA WITH
NEXT ROUND OF WARM AIR ADVECTION STORMS HEADING NORTHEAST INTO
SOUTHEAST SECTIONS. FOR NOW...INSTABILITY REMAINS LOW AT THIS TIME
AND MAIN WAVE OVER NEW MEXICO THIS MORNING NOW TURNING NORTH INTO
WESTERN KS/OK/TX AT THIS TIME. THOUGH COLD FRONT REMAINS FAR
NORTHWEST AT THIS TIME...ANOTHER WARM FRONT OVER EASTERN KS/NEBRASKA
WILL MOVE NORTHEAST LATE THIS AFTERNOON AND SHOULD BRING THE
SOUTHERN SECTIONS INTO THE WARM SECTOR AS INSTABILITY INCREASES BY
LATE AFTERNOON. MAIN CONCERNS REMAIN THE SOUTHEAST WHICH SHOULD SEE
BETTER CHANCES FOR SEVERE THIS AFTERNOON AND EVENING HOURS AS THE
SFC LOW CONSOLIDATES AND HEADS INTO NORTHEAST KS/NORTHWEST MO BY
00Z. STRONGER UPPER LEVEL WIND FIELDS REMAIN SOUTH AND EAST OF
FORECAST AREA THIS AFTERNOON...BUT ENOUGH SHEAR STILL EXISTS FOR
SEVERE STORM POTENTIAL. HAVE TRIMMED SEVERE CHANCES BACK TO AFT 21Z
WITH LESSER CHANCES FOR THUNDER MOST AREAS THIS AFTERNOON WITH THE
EXCEPTION OF THE SOUTHEAST WHERE NEXT AREA OF STORMS CURRENTLY OVER
MO WILL IMPACT REGION YET BEFORE 21Z. HIGHS LOOK SLIGHTLY COOLER
NORTH AND HAVE REDUCED HIGHS THERE BY A FEW DEGREES AS WELL.
.PREVIOUS SHORT TERM /TODAY/...
MAIN CONCERN THIS MORNING IS OBVIOUSLY CONVECTIVE TRENDS. LONG WAVE
TROUGH CONTINUES TO MOVE ACROSS THE ROCKIES WITH ASSOCIATED WARM
FRONT FROM WY/SD SURFACE LOW THROUGH MO VALLEY. RAP ANALYSIS
APPEARS TO BE HANDLING CURRENT WEATHER WELL SHOWING INTENSIFYING
THETA-E ADVECTION COINCIDENT WITH NARROW NW-SE MCS FROM NE INTO MO.
REMNANT MCS THAT FORMED NEAR PARENT UPPER LOW IN THE ROCKIES
CONTINUES TO ADVANCE ACROSS KS INTO NE...MERGING WITH WARM ADVECTION
CONVECTION. RAP 300-310K ISENT LAYER ROOTED AT TOP OF INVERSION
ADVANCES THIS MCS INTO IA AND MATURES IT THROUGH THE MORNING WITH
STRONG MOISTURE TRANSPORT. ELEVATED CAPES APPEAR TO BE AROUND 1000
J/KG WITH MARGINAL EFFECTIVE SHEAR UPSTREAM INTO IMMEDIATE MO RIVER
VALLEY. HOWEVER ESTIMATED RAP EFFECTIVE SHEAR /1-6KM/ WANES SO
REALLY DO NOT EXPECT MUCH IN THE WAY OF SEVERE WEATHER THIS
MORNING...JUST MUCH NEEDED RAIN. THE LATEST HRRR SUPPORTS THIS AS
WELL AND SEEMS TO BE CLOSER TO REALITY...UNLIKE MOST WRF RUNS...SO
WIDESPREAD CATEGORICAL POPS HAVE BEEN INCLUDED.
QUESTION BY THIS AFTERNOON TURNS TO SEVERE WEATHER POTENTIAL ALONG
WITH LESS CONFIDENCE. 60F PLUS DEWPOINTS CURRENTLY NOTED SOUTH OF
WARM FRONT ACROSS KS SHOULD ENTER IA BY THIS AFTERNOON RESULTING IN
MAX MLCAPES AROUND 1500 J/KG AND LITTLE CINH. THIS THERMODYNAMIC
ENVIRONMENT WOULD BE COINCIDENT WITH FAVORABLE DEEP SHEAR FOR
SUPERCELLS AND SHALLOW SHEAR FOR A FEW TORNADOES...ESPECIALLY S
CENTRAL/SE LATE. AGREE WITH SPC LOW TOR PROBS SOUTH BECAUSE OF
THIS...BUT UNIDIRECTIONAL S/SWLY FLOW IS NOT TOO CONDUCIVE.
HOWEVER ANOTHER QUESTION WILL BE INITIATION OR SOURCE. FRONTAL
SYSTEM AND CONVERGENCE WILL LAG THIS AREA CONSIDERABLY...STILL BACK
INTO KS/NE/NWRN IA BY 00Z...AS IS STRONGER H7/H5 FORCING IMMEDIATELY
AHEAD OF PARENT LOW. MINOR WAVES AND H85/H7 FORCING EJECTING OUT IN
SWLY UPPER FLOW COULD FORM ANOTHER MCS...OR REMNANTS FROM SRN TAIL
END OF CURRENT KS CONVECTION COULD EVENTUALLY REACH IA. HOWEVER
THIS DEVELOPMENTAL UNCERTAINTY...AND THE POTENTIAL THAT MORNING MCS
COULD HINDER THE THERMODYNAMIC ENVIRONMENT...HAS MADE THIS SEVERE
WEATHER CONDITIONAL AND LESS CERTAIN. MANY MODELS STILL DEVELOP
SOMETHING FROM THE SOUTH INTO SRN IA HOWEVER SO ALTHOUGH DETAILS NOT
CLEAR...HAVE INTRODUCED SEVERE WORDING SOUTH.
REGARDLESS OF PRECIP TRENDS...AIRMASS SHOULD FEEL SUMMERLIKE WITH
MODEL CONSENSUS PUSHING HIGHS INTO THE 70S AND DEWPOINTS INTO THE
60S. RAW MODEL TEMPS AND MOS GUIDANCE ALL SEEM TO BE IN AGREEMENT
ON THIS.
.LONG TERM /TONIGHT THRU FRIDAY/...
MODELS HAVE COME TOGETHER FOR THE MOST PART WITH THE TIMING AND
EVOLUTION OF THE LOW THIS EVENING. SURFACE LOW WILL TRACK ACROSS
IOWA...MOST LIKELY THE SOUTH HALF...THIS EVENING AND KEPT A SHORT
WINDOW FOR POTENTIAL SEVERE. THAT WILL BE OUT OF THE PICTURE BY
03Z. CHANGE IN THE EVOLUTION FROM PREVIOUS RUNS IS THE TRACK A BIT
FARTHER SOUTH...RESULTING IN A DECENT DEFORMATION ZONE CROSSING IOWA
TONIGHT AND LINGERING WELL IN TO SUNDAY MORNING. MADE ADJUSTMENTS
TO COVER THAT BOTH WITH INCREASING POPS AS WELL AS LOWERING MAX
TEMPS FOR SUN. THE NEXT WEATHER SYSTEM IS SLATED TO ARRIVE MID
WEEK. A BIG DIFFERENCE BETWEEN THE GEM AND ECMWF SOLUTIONS AND THE
GFS WITH THE DEEPENING OF THE UPPER LOW. GEM AND EC BOTH SUGGEST
COOLER AND WETTER WEATHER IS IN STORE. CURRENTLY...PRECIP IS IN FOR
THE WED TIME FRAME. KEPT IT IN THE NERN ZONES FOR THE LATER PART OF
THE WEEK...BUT MAY HAVE TO BE ADJUSTED FARTHER SOUTH AND WEST WITH
LATER PACKAGES. WITH THE SYSTEM DURING MID WEEK BEING FROM THE
NORTHERN STREAM INSTEAD OF THE SOUTHERN BRANCH...DON`T SEE THE
THUNDER THREAT AS BEING A BIG DEAL.
&&
.AVIATION...13/12Z
PERIOD OF IFR CONDITIONS ANTICIPATED EARLY THIS MORNING AS SHOWERS
AND THUNDERSTORMS MOVE THROUGH. THIS SHOULD BE FOLLOWED BY A BREAK
IN THE PRECIPITATION BUT PERSISTENT STRATUS WILL MAINTAIN ITSELF
WITH MVFR CIGS MOST PROMINENT. COULD BE LOWER BUT CONFIDENCE IN
THAT TIMING ENOUGH TO MENTION. ADDITIONAL SHOWERS AND STORMS MAY
DEVELOP THIS AFTERNOON AND EVENING SOUTH. LOW CONFIDENCE ON TIMING
AND LOCATION HOWEVER SO NOTHING MORE THAN MVFR OR LESS CIGS AND
VCSH. FARTHER NORTH STRATUS WILL PERSIST...BUT POTENTIAL FOR
THUNDER IS LESS AND MORE LIKELY JUST STEADY RAIN OR SHOWERS DURING
THE EVENING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
AVIATION...SMALL
LONG TERM...MS OCT 12
AREA FORECAST DISCUSSION
NWS GOODLAND KS
449 PM MDT SAT OCT 13 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 236 PM MDT SAT OCT 13 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW STRONG UPPER LOW CENTERED
ALONG KS/CO BORDER WITH AXIS OF MOISTURE ON BACK SIDE OF UPPER LOW
BEGINNING TO MOVE FROM CENTRAL INTO EASTERN COLORADO. RADAR
CURRENTLY INDICATED SHOWERS/ISOLATED THUNDERSTORMS DEVELOPING OVER
THE WESTERN PART OF OUR CWA ALONG KS/CO STATE LINE. THIS IS AHEAD OF
H7 TROUGH AND ALONG NORTHWESTERN AXIS OF STEEP LAPSE RATES.
LATEST HRRR AND RUC BOTH SHOW SHOWERS AND THUNDERSTORMS CONTINUING
TO DEVELOP EASTWARD ACROSS THE REST OF THE CWA THROUGH THE EARLY
EVENING. THIS ACTIVITY SHOULD DIMINISH AFTER SUNSET AS WE LOOSE THE
STEEP LOW LEVEL LAPSE RATES. WITH SCATTERED COVERAGE...AND LIGHT
NATURE OF MOST OF THIS ACTIVITY...PRECIPITATION SHOULD BE LIGHT.
DESPITE MINIMAL CAPE VALUES IN THE 100-500 J/KG RANGE AND WEAK
0-6KM SHEAR...IT WILL NOT TAKE MUCH TO PRODUCE SEVERE HAIL WITH
-20C HEIGHTS AROUND 15-18KFT ACROSS THE CWA. WITH LOW LCL VALUES
AROUND 1500 KFT AND FAVORABLE AREA BENEATH UPPER LOW WHERE
DIFFERENTIAL HEATING AXIS/SURFACE TROUGH OVERLAP...I CANT RULE OUT
FUNNEL/LANDSPOUT FORMATION WITH THIS ACTIVITY THIS AFTERNOON/EARLY
EVENING. CONSIDERING ABSENCE OF DISTINCT SURFACE BOUNDARY...AND
LOCATION OF BEST SURFACE VORTICITY FURTHER NORTH...THIS THREAT
SEEMS TO BE MINIMAL AT BEST.
THE UPPER LOW WILL SHIFT EAST OF THE CWA BY 06Z TONIGHT...WITH
SHORTWAVE RIDGING AND LARGE SCALE SUBSIDENCE OVERSPREADING THE AREA
BY SUNDAY. WITH SIMILAR H85 TEMPS AND NW WIND PERSISTING...TEMPERATURES
ON SUNDAY SHOULD AT LEAST BE SIMILAR TO THIS AFTERNOON WITH HIGHS
IN THE 70S FOR MOST OF THE AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 236 PM MDT SAT OCT 13 2012
SUNDAY NIGHT THROUGH MONDAY NIGHT DRY NORTHWEST UPPER LEVEL FLOW
WILL CONTINUE OVER THE AREA. A SHORT WAVE TROUGH MOVES THROUGH THE
FLOW LATE MONDAY NIGHT ACCOMPANYING A SURFACE TROUGH/WEAK COLD
FRONT. POINT SOUNDINGS INDICATE THE UPPER LEVELS MOISTEN AS THE
SHORT WAVE MOVES THROUGH...SO AM ONLY EXPECTING A FEW CLOUDS TO
DEVELOP DURING THE OVERNIGHT HOURS.
TUESDAY THROUGH SATURDAY WILL REMAIN DRY. A COLD FRONT AND UPPER
LEVEL SHORT WAVE TROUGH WILL MOVE THROUGH WEDNESDAY. BEHIND THE
COLD FRONT WINDS WILL BECOME GUSTY DURING THE AFTERNOON. MOISTURE
WILL REMAIN NORTH OF THE AREA...SO AM NOT ANTICIPATING ANY PRECIP
WITH THE FRONT. THERE MAY BE SOME LIFT FROM THE LEFT EXIT OF THE 500
MB JET...BUT MODELS DISAGREE WITH THE JET PLACEMENT BEHIND THE
FRONT. WITH THE MOISTURE GENERALLY NORTH OF THE AREA AND THE
POSITION OF THE JET IN QUESTION...WILL LEAVE THE FRONTAL PASSAGE DRY.
OTHERWISE TEMPERATURES WILL BE 10 DEGREES ABOVE NORMAL AHEAD THE
COLD FRONT...WITH NEAR NORMAL TEMPERATURES BEHIND THE FRONT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 441 PM MDT SAT OCT 13 2012
SHOWERS AND STORMS CURRENTLY ON RADAR WILL SLOWLY WEAKEN AFTER
SUNSET. THESE HAVE MOVED EAST OF KGLD BUT KMCK WILL CONTIUE TO
HAVE A SLIGHT CHANCE. OTHERWISE, CLOUDS WILL CLEAR OUT OVERNIGHT
WITH VFR CONDITIONS THROUGH THE END OF THIS FORECAST PERIOD.
GUSTY NORTHWEST WIND AND SCATTERED CUMULUS ARE EXPECTED BY MIDDAY
SUNDAY BEHIND THE EXITING LOW PRESSURE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
241 PM MDT SAT OCT 13 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 236 PM MDT SAT OCT 13 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW STRONG UPPER LOW CENTERED
ALONG KS/CO BORDER WITH AXIS OF MOISTURE ON BACK SIDE OF UPPER LOW
BEGINNING TO MOVE FROM CENTRAL INTO EASTERN COLORADO. RADAR
CURRENTLY INDICATED SHOWERS/ISOLATED THUNDERSTORMS DEVELOPING OVER
THE WESTERN PART OF OUR CWA ALONG KS/CO STATE LINE. THIS IS AHEAD OF
H7 TROUGH AND ALONG NORTHWESTERN AXIS OF STEEP LAPSE RATES.
LATEST HRRR AND RUC BOTH SHOW SHOWERS AND THUNDERSTORMS CONTINUING
TO DEVELOP EASTWARD ACROSS THE REST OF THE CWA THROUGH THE EARLY
EVENING. THIS ACTIVITY SHOULD DIMINISH AFTER SUNSET AS WE LOOSE THE
STEEP LOW LEVEL LAPSE RATES. WITH SCATTERED COVERAGE...AND LIGHT
NATURE OF MOST OF THIS ACTIVITY...PRECIPITATION SHOULD BE LIGHT.
DESPITE MINIMAL CAPE VALUES IN THE 100-500 J/KG RANGE AND WEAK
0-6KM SHEAR...IT WILL NOT TAKE MUCH TO PRODUCE SEVERE HAIL WITH
-20C HEIGHTS AROUND 15-18KFT ACROSS THE CWA. WITH LOW LCL VALUES
AROUND 1500 KFT AND FAVORABLE AREA BENEATH UPPER LOW WHERE
DIFFERENTIAL HEATING AXIS/SURFACE TROUGH OVERLAP...I CANT RULE OUT
FUNNEL/LANDSPOUT FORMATION WITH THIS ACTIVITY THIS AFTERNOON/EARLY
EVENING. CONSIDERING ABSENCE OF DISTINCT SURFACE BOUNDARY...AND
LOCATION OF BEST SURFACE VORTICITY FURTHER NORTH...THIS THREAT
SEEMS TO BE MINIMAL AT BEST.
THE UPPER LOW WILL SHIFT EAST OF THE CWA BY 06Z TONIGHT...WITH
SHORTWAVE RIDGING AND LARGE SCALE SUBSIDENCE OVERSPREADING THE AREA
BY SUNDAY. WITH SIMILAR H85 TEMPS AND NW WIND PERSISTING...TEMPERATURES
ON SUNDAY SHOULD AT LEAST BE SIMILAR TO THIS AFTERNOON WITH HIGHS
IN THE 70S FOR MOST OF THE AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 236 PM MDT SAT OCT 13 2012
SUNDAY NIGHT THROUGH MONDAY NIGHT DRY NORTHWEST UPPER LEVEL FLOW
WILL CONTINUE OVER THE AREA. A SHORT WAVE TROUGH MOVES THROUGH THE
FLOW LATE MONDAY NIGHT ACCOMPANYING A SURFACE TROUGH/WEAK COLD
FRONT. POINT SOUNDINGS INDICATE THE UPPER LEVELS MOISTEN AS THE
SHORT WAVE MOVES THROUGH...SO AM ONLY EXPECTING A FEW CLOUDS TO
DEVELOP DURING THE OVERNIGHT HOURS.
TUESDAY THROUGH SATURDAY WILL REMAIN DRY. A COLD FRONT AND UPPER
LEVEL SHORT WAVE TROUGH WILL MOVE THROUGH WEDNESDAY. BEHIND THE
COLD FRONT WINDS WILL BECOME GUSTY DURING THE AFTERNOON. MOISTURE
WILL REMAIN NORTH OF THE AREA...SO AM NOT ANTICIPATING ANY PRECIP
WITH THE FRONT. THERE MAY BE SOME LIFT FROM THE LEFT EXIT OF THE 500
MB JET...BUT MODELS DISAGREE WITH THE JET PLACEMENT BEHIND THE
FRONT. WITH THE MOISTURE GENERALLY NORTH OF THE AREA AND THE
POSITION OF THE JET IN QUESTION...WILL LEAVE THE FRONTAL PASSAGE DRY.
OTHERWISE TEMPERATURES WILL BE 10 DEGREES ABOVE NORMAL AHEAD THE
COLD FRONT...WITH NEAR NORMAL TEMPERATURES BEHIND THE FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1127 AM MDT SAT OCT 13 2012
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE PERIOD AT BOTH
KGLD AND KMCK TERMINALS. GUSTY NORTHWEST WINDS WILL CONTINUE AT
KGLD THROUGH THE EVENING WITH GUSTS UP TO 30KT POSSIBLE. WINDS
WILL BE SLOWER TO INCREASE AT KMCK WITH SURFACE TROUGH IN
PROXIMITY OF TERMINAL...THOUGH GUSTS AROUND 25KT ARE STILL
EXPECTED TO DEVELOP BY SUNRISE. WINDS SHOULD DIMINISH BY 03Z AT
BOTH TERMINALS AS PRESSURE GRADIENT WEAKENS AND MIXING
DIMINISHES. BASED ON UPSTREAM RADAR TRENDS AND 12Z GUIDANCE
CONFIDENCE HAS INCREASED IN SHOWER/ISO THUNDERSTORM POTENTIAL AT
KGLD...THOUGH COVERAGE IS STILL A QUESTION. FOR NOW I HAVE
INTRODUCED A TEMPO GROUP FOR -SHRA DURING THE AFTERNOON PERIOD.
TOO LITTLE CONFIDENCE AT THIS POINT TO INCLUDE MENTION AT KMCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS WICHITA KS
1250 PM CDT SAT OCT 13 2012
.DISCUSSION...
WARM AIR/MOISTURE ADVECTION WILL KEEP RAIN SHOWERS/THUNDERSTORMS
GOING FOR MOST OF AFTERNOON ALONG/EAST OF I-35. THIS WILL RESULT IN
MAINLY VFR AND BRIEFLY IFR CONDITIONS AT KCNU...AND WILL LIKELY
FLIRT WITH KICT. NAM APPEARS TO BE ON TRACK AND SUGGEST ORGANIZED
STRONG-SEVERE STORMS WILL DEVELOP ALONG DRYLINE THIS AFTERNOON
AND TRAVERSE OVER MOST OF THE AREA LATE THIS AFTERNOON/EARLY
EVENING. DRYLINE MAY BE THROUGH KRSL BEFORE STORMS DEVELOP...BUT
KHUT/KICT/KSLN SHOULD ALL BE IMPACTED. STRONGEST STORMS WOULD BE
AROUND KHUT/KICT WITH G40KT LIKELY AND DECENT THREAT FOR SEVERE
STORMS. DRIER AIR BEHIND FRONT/DRYLINE WILL QUICKLY END PRECIPITATION
AND ERODE LOW CLOUDS WITH GUSTY NORTHWEST WINDS ANTICIPATED FOR
THE REST OF THE PERIOD. -HOWERTON
&&
.PREV DISCUSSION... /ISSUED 657 AM CDT SAT OCT 13 2012/
AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
WIDESPREAD SHOWERS AND THUNDERSTORMS WERE ONGOING ACROSS MUCH OF
CENTRAL AND SOUTH CENTRAL KANSAS THIS MORNING WITH MVFR
CIGS/VISIBILITIES PREVAILING. THIS ACTIVITY WILL CONTINUE TO DEVELOP AND
MOVE EASTWARD IMPACTING SOUTHEAST KANSAS THROUGH THE MORNING
HOURS. A VIGOROUS STORM SYSTEM OVER THE CENTRAL AND SOUTHERN
ROCKIES WILL MOVE EAST AND THUNDERSTORMS ARE EXPECTED TO REDEVELOP
ALONG A PACIFIC FRONT ACROSS CENTRAL KANSAS THIS AFTERNOON. SEVERE
THUNDERSTORMS WILL LIKELY IMPACT PORTIONS OF CENTRAL AND MUCH OF SOUTH
CENTRAL AND SOUTHEAST KANSAS THIS AFTERNOON AND EVENING BEFORE
DEPARTING EAST DURING THE OVERNIGHT HOURS.
MWM
PREV DISCUSSION... /ISSUED 321 AM CDT SAT OCT 13 2012/
DISCUSSION...
TODAY AND TONIGHT:
ONGOING CONVECTION ACROSS WESTERN KANSAS IS MAKING THE CONVECTIVE
FORECAST FOR LATER TODAY A LITTLE MURKY. SYNOPTIC MODELS DID NOT
HANDLE CONVECTION EVOLUTION DURING THE OVERNIGHT HOURS VERY
WELL...WITH MESO-SCALE MODELS PERFORMING ONLY SLIGHTLY BETTER.
RUC13 APPEARS TO HAVE THE BEST HANDLE ON CONVECTIVE EVOLUTION IN
THE VERY SHORT TERM...THUS WILL USE IT AS A GUIDE AT LEAST THROUGH
THE MORNING HOURS.
AFTER MORNING CONVECTION MOVES EAST OF THE CWA...EXPECT A BRIEF
LULL IN ACTIVITY DUE TO SUBSIDENCE BEHIND MORNING
CONVECTION...BEFORE STORMS RE-FIRE BY EARLY TO MID-AFTERNOON.
TIMING OF WHEN STORMS WILL RE-FIRE AND EXACTLY WHERE STILL IS
UNCLEAR...BUT JUXTAPOSITION OF BEST KINEMATICS AND INSTABILITY
SUGGEST INITIATION SHOULD OCCUR IN THE SOUTHWEST CORNER OF CWA.
FORECAST SOUNDINGS NOT DEPICTING LARGE CAPE VALUES...WITH LARGE
SCALE MOISTURE FLUX LIMITING AMOUNT OF MID-LEVEL DRYING. LARGE
SCALE KINEMATICS SUGGEST CONVECTION WILL BE MAINLY LINEAR IN
NATURE...HOWEVER NAM AND RUC HINT AT A DEVELOPMENT OF MESOLOW
ALONG OR JUST NORTH OF OK-KS BORDER...WHICH COULD INCREASE LOW
LEVEL HELICITY ENOUGH TO ALLOW ISOLATED SUPERCELL TO DEVELOP. FEEL
ANY ISOLATED STORM THAT DEVELOPS WILL NOT LAST TOO LONG...WITH
QLCS BEING THE DOMINATE CONVECTION MODE. BEST POTENTIAL FOR SEVERE
CONVECTION WILL BE DURING THE AFTERNOON INTO EARLY EVENING
HOURS...WITH BULK OF CONVECTION EXITING THE CWA BY MIDNIGHT.
SUN-MON:
LARGE SCALE SUBSIDENCE BEHIND DEPARTING UPPER SYSTEM WILL ALLOW
SKIES TO CLEAR QUICKLY AT LEAST MID-MORNING SUNDAY. WEAK COLD AIR
ADVECTION BEHIND SURFACE COLD FRONT WILL KEEP TEMPERATURES
SLIGHTLY COOLER FOR SUNDAY...ESPECIALLY ACROSS EASTERN PART OF THE
CWA. TEMPERATURES WILL REBOUND ON MONDAY WITH WEAK DOWNSLOPE
WARMING. DRY CONDITIONS ARE EXPECTED.
TUE-THU:
BULK OF THE LONGER RANGE PORTION OF THE FORECAST APPEARS
QUIET. GEFS AND LONGER RANGE OPERATIONAL MODELS SHOWING SOME
DIFFLUENCE IN THE WED-THU TIME FRAME IN THE TIMING OF SHORT WAVE
FEATURE MOVING OUT OF WESTERN CANADA. APPEARS AREA WILL EXPERIENCE
THE PASSAGE OF ANOTHER COLD FRONT BY MID-WEEK...HOWEVER
PRECIPITATION CHANCES IN QUESTION. GULF WILL REMAIN SOMEWHAT
BLOCKED...SO ANY PRECIPITATION WILL BE CONCENTRATED IN PROXIMITY
OF UPPER DYNAMICS...WHICH SHOULD BE FOCUSED NORTH AND EAST OF
FORECAST AREA. HOWEVER...THERMODYNAMIC FORCING MAY ALLOW SCATTERED
CONVECTION TO DEVELOP ALONG FRONT...SO WILL MAINTAIN LOW CHANCE
POPS ACROSS MAINLY EASTERN CWA. TEMPERATURES SHOULD NO DEVIATE TOO
MUCH FROM NORMALS...THUS ACCEPTED GUIDANCE AS A WHOLE.
SF
PREV DISCUSSION... /ISSUED 1156 PM CDT FRI OCT 12 2012/
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE ANTICIPATED UPPER LEVEL LOW IS STILL MAKING ITS WAY INTO THE
HIGH PLAINS...BUT LIFT ASSOCIATED WITH IT IS ALREADY FORMING A
NICE LINE OF STORMS IN WESTERN KANSAS. THE STORY FOR MOST SITES
HAS BEEN IFR CONDITIONS WITH OCCASIONAL MVFR AND/OR LIFR. LOW
VISBYS AND CIGS APPEAR TO BE ON A KINGMAN TO SALINA LINE EXTENDING
TO THE NORTHWEST. BASIC EXPECTED TRENDS ARE FOR BANDS OF SHOWERS
AND THUNDERSTORMS TO PASS OVER THE CENTRAL KANSAS SITES NEAR AND
JUST BEFORE SUNRISE...THEN MOVE SLOWLY TO THE NORTH AND EAST AS
THE SURFACE LOW DEEPENS IN THE LEE OF THE ROCKIES. THIS SURFACE
LOW WILL TIGHTEN UP A DRY LINE AND MOVE EAST...AND DEPENDING ON
THE CLEARING BETWEEN THE MORNING CLOUDS AND PRECIP AND THE DRY
LINE...SHOULD FIRE NEW STORMS LATER SATURDAY AFTERNOON. THE AREAL
EXTENT OF THESE STORMS CAN`T BE PINNED DOWN YET...BUT IS EXPECTED
TO AFFECT ALL SITES EXCEPT FOR CNU...WHICH WILL SEE THE EFFECTS OF
THESE STORMS LATER IN THE EVENING. -LAUGEMAN
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 78 52 77 49 / 70 30 0 0
HUTCHINSON 79 51 78 48 / 60 30 0 0
NEWTON 77 51 77 49 / 60 30 0 0
ELDORADO 76 51 77 49 / 70 40 10 0
WINFIELD-KWLD 78 52 78 50 / 70 40 0 0
RUSSELL 79 48 77 46 / 40 30 0 0
GREAT BEND 80 49 77 47 / 50 20 0 0
SALINA 80 50 77 49 / 60 30 10 0
MCPHERSON 79 50 77 48 / 60 30 0 0
COFFEYVILLE 78 56 79 51 / 80 70 10 0
CHANUTE 76 54 77 50 / 80 70 10 0
IOLA 76 54 76 50 / 80 70 10 0
PARSONS-KPPF 77 54 78 50 / 80 80 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1240 PM CDT SAT OCT 13 2012
...UPDATE TO AVIATION...
.DISCUSSION...
WATER VAPOR IMAGERY SHOWING CENTER OF THE UPPER LOW JUST NORTH OF
THE FOUR CORNERS MOVING EASTWARD AS ANOTHER STRONG SHORTWAVE TROUGH
SWINGS EAST SOUTHEASTWARD AROUND THE SOUTHERN PORTIONS OF THE
TROUGH. CONVECTION HAS CONTINUED TO DEVELOP THROUGH THE NIGHT AHEAD
OF THE MAIN TROUGH THROUGH THE CENTRAL AND SOUTHERN HIGH PLAINS AS
IT MARCHES NORTHEASTWARD AND SLOWLY WEAKENS. MANY OF THE MODELS
ARE NOT HANDLING THIS EXPANSIVE AREA OF CONVECTION AND ITS
MOVEMENT..ALTHOUGH THE RAP IS DOING THE BEST AND INITIALLY HAVE
LEANED WITH ITS GRADUAL EASTWARD MOTION THROUGH THE MORNING WITH
ADDITIONAL DEVELOPMENT OUT AHEAD OF THIS INITIAL CONVECTION ACROSS
MUCH OF THE CENTRAL PORTIONS OF THE CWA THIS MORNING. RECENT RADAR
LOOPS ARE CONFIRMING MORE ELEVATED CONVECTION OUT AHEAD OF THE
LINE AND SOUTHWARD INTO OK. ALSO...NAM AND RECENTLY THE NEW EC
SUGGEST A SLOWER...DEEPER AND FURTHER SOUTH TRACK TO THE UPPER
TROUGH AS IT PROGRESSES ACROSS THE CWA LATE TODAY AND TONIGHT.
THIS COULD RESULT IN A MORE BACKED UPPER FLOW TODAY AND DELAY THE
EASTWARD PROGRESSION OF THIS MORNINGS CONVECTION AND MIDDAY
INSOLATION. ALL IN ALL...THIS COULD CREATE A CHALLENGE IN
FORECASTING THE DEGREE OF INSTABILITY AND RESULTING DEGREE OF THE
SEVERE THUNDERSTORM POTENTIAL ACROSS THE CWA THIS AFTERNOON INTO
THE EVENING. EITHER WAY...ELEVATED SHOWERS AND THUNDERSTORMS WILL
BE PREVALENT THIS MORNING WITH AN "EXPECTED" BREAK IN CONVECTION
BY MIDDAY FOLLOWED BY ADDITIONAL STRONGER DEVELOPMENT AHEAD OF THE
FRONT AND WITHIN INCREASING LARGE SCALE ASCENT AS A JET MAX ROUNDS
THE BASE OF THE UPPER TROUGH AS IT MOVES OUT INTO THE CENTRAL
PLAINS. WITH THE VERY STRONG SHEAR AND CAPE...ANY SUSTAINED
DISCRETE STORMS THAT ARE ABLE TO FORM THIS AFTERNOON MAY BE
CAPABLE OF PRODUCING LARGE HAIL...STRONG WINDS AND POSSIBLY AN
ISOLATED TORNADO PRIMARILY ACROSS NORTHEAST AND EAST CENTRAL AREAS.
HOWEVER...WITH THE ORIENTATION OF LARGE SCALE FORCING AND A MORE
PREDOMINANT UNIDIRECTIONAL FLOW...WOULD EXPECT STORMS TO FORM A
LINE OR LINE SEGMENTS WITH THE MAIN SEVERE POTENTIAL BEING VERY
STRONG STRAIGHTLINE WINDS. AGAIN...DEGREE OF INSTABILITY MAY BE
AFFECTED BY PRECIP COVERAGE AND CLOUD COVER. WITH INCREASING
PRECIPITABLE WATER VALUES APPROACHING AN INCH AND THREE
QUARTERS...LOCALLY HEAVY RAINFALL CAN ALSO BE EXPECTED IN SOME
AREAS. WITH THE SLOWER AND MORE SOUTHWARD TRACK OF THE
TROUGH...HAVE EXTENDED HIGHER POPS BEYOND MIDNIGHT TONIGHT...BUT
STILL ENDED BY SUNRISE ON SUNDAY. LOWERED HIGH TEMPS SLIGHTLY
TODAY THROUGH THE LOWER AND MIDDLE 70S AND AGAIN ON
SUNDAY...ESPECIALLY IN THE FAR EAST.
HAVE MAINTAINED A DRY FCST SUNDAY THROUGH TUESDAY WITH HIGHS IN THE
70S...THEN KEPT THE BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS
CENTERED ON WEDNESDAY AS THE NEXT COLD FRONT AND UPPER TROUGH MOVES
THROUGH THE NORTHERN PLAINS AND MIDWEST. WILL KEEP HIGHS BEHIND THE
FRONT IN THE 60S FOR THURSDAY AND FRIDAY...BUT STILL DRY AS MAIN
TROUGH SETS UP TO THE EAST IN THE MS AND OH RIVER VALLEYS. 63
&&
.AVIATION...
MVFR CEILINGS WILL CONTINUE THROUGH 06Z AT TAF SITES. OCCASIONAL
IFR CONDITIONS WILL BE POSSIBLE DURING PERIODS OF PRECIPITATION.
SCATTERED SHOWERS WILL BE POSSIBLE AT TOP/FOE...WITH THUNDERSTORMS
DEVELOPING AND IMPACTING TAF SITES DURING THE 23Z-04Z WINDOW. A
RETURN TO VFR CONDITIONS WILL BECOME POSSIBLE AFTER 06Z...WITH
CLEARING SKIES BY MID MORNING SUNDAY.
BLAIR
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
424 PM EDT SAT OCT 13 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 423 PM EDT SAT OCT 13 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A ZONALLY ORIENTED FLOW
ACROSS SRN CANADA AND THE FAR NRN CONUS. TO THE S...A SHORTWAVE TROF
IS EMERGING FROM CO/NM INTO THE WRN PLAINS. DEEP/MOIST SW FLOW
DOWNSTREAM OF THE TROF HAS GENERATED SEVERAL AREAS OF SHRA AND SOME
TSRA FROM THE SRN PLAINS TO THE GREAT LAKES. WITH THE MORE ZONALLY
ORIENTED FLOW ACROSS THE FAR NRN CONUS...THE AREAS OF SHRA HAVE BEEN
TENDING TO SHIFT MORE EASTWARD THE FARTHER N THEY SPREAD. AS A
RESULT...THERE HAS BEEN LITTLE PCPN OVER THE NW HALF OF THE FCST
AREA TODAY (MUCH OF THE PCPN HAS BEEN DRIZZLE) WHILE THE SE HALF HAS
BEEN GETTING BRUSHED BY SHRA.
PCPN TRENDS/COVERAGE WILL BE THE MAIN FCST ISSUES IN THE SHORT TERM.
FLOW ACROSS SRN CANADA/FAR NRN CONUS IS EXPECTED TO BUCKLE AS HEIGHT
RISES OVER WRN NAMERICA FORCE DOWNSTREAM HEIGHT FALLS INTO
MISSISSIPPI VALLEY REGION. THIS WILL HELP TO PICK UP/LIFT THE WRN
PLAINS SHORTWAVE TO THE NE. EXACTLY HOW FAR N IT LIFTS WILL BE
IMPORTANT TO THE PCPN FCST TONIGHT/SUN. EVEN AT THIS SHORT TIME
RANGE INTO MODEL RUNS...THERE ARE STILL IMPORTANT DIFFERENCES IN THE
MODELS. THE NAM REMAINS MOST SUPPRESSED WITH THE LOW TRACK THOUGH IT
HAS TRENDED SLIGHTLY N...AND IT IS SUPPORTED BY OUR LOCAL REG WRF
RUN AND THE NCEP HIGH RES WRF-ARW AND WRF-NMN. THEY ALL KEEP THE
MAIN PCPN SHIELD ALMOST ENTIRELY SE OF FCST AREA SUN. THE 12Z GFS
HAS TRENDED S AND ONLY BRINGS PCPN SHIELD INTO THE SE FCST AREA. THE
UKMET/REGIONAL GEM PUSH PCPN SHIELD A LITTLE FARTHER N AND W. THE 12Z
ECMWF HAS ALSO TRENDED SLIGHTLY S. GIVEN OVERALL TRENDS AND A
MAJORITY SHOWING A LESS AGGRESSIVE MOISTURE PUSH INTO UPPER MI
SUN...FCST WILL FOLLOW SUIT AND SHOW HIGHER POPS SHIFTED MORE TO THE
S AND E.
CURRENT PUSH OF SHRA ENE THRU WI INTO SRN UPPER MI IS ASSOCIATED
WITH A SURGE OF 850-700MB MOISTURE TRANSPORT AND ISENTROPIC ASCENT
ON THE 305K SFC. WITH THAT MOISTURE TRANSPORT/ASCENT QUICKLY
SHIFTING E THIS EVENING...AND THEN RATHER MEAGER FORCING LEFT BEHIND
FOR THE NIGHT...IT APPEARS THERE WON`T BE MUCH IN THE WAY OF
RAINFALL FOR THE BULK OF TONIGHT AS WE AWAIT THE MAIN PIECE OF
ENERGY TO TRACK INTO THE GREAT LAKES SUN. WITH WINDS BECOMING LIGHT
UPSLOPE OFF LAKE SUPERIOR DURING THE NIGHT...-DZ THAT HAS BEEN
OCCURRING TODAY WILL LIKELY CONTINUE TONIGHT...ESPECIALLY ACROSS THE
NCNTRL.
SHORTWAVE LIFTS INTO THE GREAT LAKES SUN AFTN WITH ASSOCIATED SFC
LOW TRACKING TOWARD NRN LWR MI. AS A RESULT...RAIN WILL SPREAD BACK
TO THE N...BUT AS DISCUSSED ABOVE...LOWERED POPS FROM PREVIOUS FCST.
KEPT CATEGORICAL POPS ONLY ALONG LAKE MICHIGAN INTO THE FAR ERN FCST
AREA WITH POPS DROPPING OFF SHARPLY TO CHC JUST TO THE NW. MAY SEE A
LITTLE LAKE ENHANCED SHRA ACTIVITY IN THE NNE/NE WIND FAVORED
LOCATIONS...SO SHRA CHANCES IN THOSE AREAS WILL BE A LITTLE HIGHER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 423 PM EDT SAT OCT 13 2012
A FAIRLY STRONG UPPER SHORTWAVE TROUGH WILL BE OVER THE CENTRAL CWA
AT 00Z MON...DEEPENING AS IT MOVES TO THE FAR ERN CWA BY 06Z MON DUE
TO A WEAK SHORTWAVE PHASING WITH THE SYSTEM. AT THE SFC...A ROUGHLY
995MB LOW WILL BE OVER OVER NRN LOWER MI AT 00Z MON...MOVING TO
GEORGIAN BAY BY 06Z MON. THE 850MB LOW WILL BE JUST E OF DRUMMOND
ISLAND AT 00Z MON...WITH A NICE DEFORMATION PRECIP BAND JUST ON THE
LEFT SIDE OF THE 850MB LOW TRACK AS IT MOVES NE. THERE SHOULD BE A
PRETTY SHARP CUT OFF BETWEEN THE DEFORMATION BAND AND LITTLE TO NO
SYNOPTIC RAIN...AND AFTER 00Z SUN...THE CWA SHOULD BE ON THE DRIER
SIDE OF THAT CUT OFF. HOWEVER...WITH THE SHORTWAVE DEEPENING
OVERHEAD THEN MOVING E...COLDER 850MB TEMPS WILL FILTER IN FROM THE
NNW. WITH THE NNW LOW LEVEL WINDS AND 850MB TEMPS OF -3C TO
-4C...SOME LIGHT LAKE EFFECT RAIN /MIXING WITH SNOW OVER THE HIGHER
TERRAIN/ WILL LINGER INTO MONDAY MORNING OVER NCENTRAL AND ERN UPPER
MI.
A SFC RIDGE WILL MOVE OVER MON AFTERNOON AND EVENING...BRINGING A
BRIEF DRY PERIOD BEFORE A SHORTWAVE TROUGH AND ASSOCIATED WARM FRONT
MOVE INTO THE CWA. PRECIP CHANCES MOVE BACK IN WITH THIS SYSTEM
AFTER MIDNIGHT MON NIGHT...WITH AT LEAST SLIGHT CHANCE POPS OVER
PARTS OF THE CWA UNTIL MORE PRECIP ARRIVES WITH A LOW PRESSURE
SYSTEM MOVING IN FROM THE W ON WED. HIGHS ON MON LOOK TO BE IN THE
UPPER 40S TO MID 50...WITH WARMER TEMPS ON TUE IN THE 50S. WED LOOKS
TO CONTINUE THE WARM TREND WITH HIGHS AGAIN IN THE 50S. OVERALL GOOD
CONFIDENCE INTO WED.
CONFIDENCE DECREASES AS THE NEXT SYSTEM MOVES IN WED INTO THE END OF
NEXT WEEK SINCE MODELS GENERALLY SHOW THE SAME IDEA OF THE LOW
CLOSING OFF ON THU AND LINGERING SOMEWHERE OVER/NEAR THE REGION
THROUGH THE END OF THE WEEK. HOWEVER...MODELS SHOW SIGNIFICANTLY
VARYING SOLUTIONS WITH WHERE TO HAVE THE LOW...WHICH CAUSES WIDELY
DIFFERENT PRECIP/WIND SCENARIOS. EVEN WITH THE DIFFERENCES...WILL
HAVE CHANCES OF PRECIP FOR THE REST OF THE PERIOD LATE WED THROUGH
SAT...DERIVED FROM CONSENSUS OF MODELS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 130 PM EDT SAT OCT 13 2012
LOW PRES OVER THE PLAINS WILL MOVE NORTHEAST TOWARD THE WRN GREAT
LAKES DURING THE FCST PERIOD. ABUNDANT MOISTURE STREAMING N AHEAD OF
SYSTEM HAS RESULTED IN WIDESPREAD MOSTLY IFR CONDITIONS ACROSS WI
INTO UPPER MI. WHILE A DOWNSLOPE SOUTHERLY WIND MAY SUPPORT BRIEF
VFR CONDITIONS AT KIWD THIS AFTN...EXPECT MVFR CONDITIONS TO
PREVAIL. MAY SEE A PERIOD OF IFR CONDITIONS/-DZ LATER TONIGHT AS NNE
WINDS STRENGTHEN ACROSS LAKE SUPERIOR. AT KCMX...LIFR/IFR CONDITIONS
SHOULD GENERALLY PREVAIL INTO THE EVENING HRS. ADVECTION OF SLIGHTLY
DRIER AIR AND A SLIGHT DOWNSLOPE COMPONENT TO THE WIND LATER
TONIGHT/SUN MORNING SHOULD HELP CIGS RISE TO MVFR. AT KSAW...IFR
CONDITIONS MAY RISE TO LOW MVFR LATE THIS AFTN/EVENING AS WINDS
SHIFT TO A LIGHT DOWNSLOPE DIRECTION. LIFR CONDITIONS EXPECTED LATER
TONIGHT/SUN MORNING AS UPSLOPE NNE WINDS STRENGTHEN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EDT SAT OCT 13 2012
WINDS ARE IN THE PROCESS OF DIMINISHING ACROSS LAKE SUPERIOR AS LOW
PRES TROF/WEAKER PRES GRADIENT SHIFT OVER THE AREA. LATER TONIGHT
AND INTO SUN...N TO NE WINDS WILL INCREASE AS LOW PRES MOVES NE
TOWARD NRN LWR MICHIGAN. DURING SUN AFTN...WINDS SHOULD BE IN THE
20-30KT RANGE OVER THE CNTRL AND ERN PORTIONS OF LAKE SUPERIOR.
WINDS WILL BE LIGHTER OVER THE FAR W. SOME NORTHERLY GALE GUSTS OVER
EASTERN LAKE SUPERIOR ARE POSSIBLE INTO SUNDAY NIGHT AS THE LOW
MOVES EAST OF THE AREA AND HIGH PRESSURE PUSHES IN FROM THE WEST.
WINDS SETTLE DOWN MONDAY AND MONDAY NIGHT WITH ARRIVAL OF HIGH
PRESSURE. ANOTHER LOW PRESSURE WILL MOVE INTO THE UPPER GREAT LAKES
ON WEDNESDAY. SOUTH WINDS COULD PUSH UP TO 25 KTS AHEAD OF THE LOW
ON TUESDAY...MAINLY FOR EASTERN SECTIONS. OTHERWISE...WINDS IN THE
VICINITY OF THE LOW SHOULD REMAIN LESS THAN 20 KTS WEDNESDAY INTO
THURSDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON/TITUS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
318 PM CDT SAT OCT 13 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY
MUCH WARMER AND MOISTER AIR HAS REACHED THE REGION AHEAD OF AN
ADVANCING UPPER-LEVEL LOW. SUBJECTIVE 12Z UPPER AIR ANALYSIS
INDICATES OPENING UPPER LOW CENTERED IN SOUTHERN CO...WITH 500MB
HEIGHT FALLS UP TO 90M IN EASTERN CO INDICATING THE WAVE IS EJECTING
INTO THE CENTRAL PLAINS. CORE OF UPPER-LEVEL JET EXTENDED FROM GULF
OF CA THROUGH WESTERN KS/NEB AND INTO CENTRAL MN...WITH STRONGER
NORTHERN STREAM JET STREAK NOSING INTO THE PACIFIC NORTHWEST. AHEAD
OF THE UPPER LOW...850MB MOISTURE HAD SPREAD NORTHWARD FROM OK/TX
INTO NEB/IA...WITH 850MB WINDS UP TO 50-60KT IN EASTERN KS/EASTERN
NEB. SURFACE LOW AT 19Z WAS CENTERED IN NORTH CENTRAL NEB...WITH
COLD FRONT LAGGING FROM SOUTHWEST NEB THROUGH WESTERN KS TO THE
OK/TX PANHANDLES. SURFACE DEWPOINTS IN EASTERN NEB/WESTERN IA ALONG
AND SOUTH OF I-80 WERE IN THE 60S.
MAIN FORECAST CONCERN IS CONVECTIVE POTENTIAL THIS EVENING...WITH
RAIN LINGERING INTO TONIGHT IN THE SOUTHEASTERN CWA. THOUGH UPPER-
LEVEL WAVE IS OPENING...IT REMAINS POTENT. RAP ANALYSIS INDICATES
MLCAPE OF 1000+ J/KG REACHING SOUTH CENTRAL NEB. DEEP-LAYER
EFFECTIVE BULK SHEAR CERTAINLY IS POTENT...AT OR ABOVE 40KT ACROSS
MOST OF SOUTHEAST NEB/SOUTHWEST IA. INTERMITTENT CLOUDS HAVE BEEN
IN PLACE ALL ACROSS THE AREA...BUT ENOUGH SUN IS BREAKING THROUGH TO
ALLOW SOME HEATING AND DESTABILIZATION. THINK CONVECTION COULD
DEVELOP IN CENTRAL KS IN THE LATE AFTN...THEN MOVE NORTHEASTWARD
INTO SOUTHEAST NEB AND EVENTUALLY SOUTHEAST IA THROUGH THE EVENING
HOURS. DO THINK THAT STORMS THAT MOVE INTO THE AREA COULD CARRY A
RISK OF HAIL...AND ALSO WIND...ESPECIALLY AS THEY ORGANIZE INTO A
LINE LATER THIS EVENING AHEAD OF THE FRONT...AS ORIENTATION OF SHEAR
VECTOR IS NEARLY PARALLEL TO FRONTAL FORCING. DO THINK TORNADO
POTENTIAL IS LIMITED BY VEERED SURFACE WIND PROFILE. STORMS SHOULD
PROGRESS ACROSS THE AREA THROUGH THE EVENING HOURS. ECMWF CONTINUES
TO HOLD ONTO A DEFORMATION-ZONE AREA OF RAIN BEHIND THE UPPER-
LOW...WITH A STRONGER LOW THAN NAM/GFS/GEM/UKMET. HELD ONTO A
SHOWER MENTION LATE TONIGHT IN THE SOUTHEAST CWA AS A NOD TO THE
STRONGER ECMWF SOLUTION.
UPPER-LEVEL SYSTEM LACKS ANY KIND OF COLD AIR PUSH BEHIND IT...AND
MILD TEMPERATURES WILL CONTINUE INTO THE WORK WEEK. TEMPS SHOULD
PEAK ON MONDAY UNDER WARM AIR ADVECTION AND LOW-LEVEL
SOUTH/SOUTHWESTERLY FLOW...WITH HIGHS LIKELY TO CRACK 80 IN PARTS OF
EASTERN NEB. A WEAK FRONTAL PASSAGE ASSOCIATED WITH A WEAK UPPER-
LEVEL WAVE WILL SKIRT THROUGH THE AREA ON TUESDAY...BRINGING MAYBE A
FEW EXTRA CLOUDS AND A SLIGHT DIP IN TEMPERATURES TO LESS ABOVE-
NORMAL READINGS.
MAYES
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
GLOBAL MODELS ARE IN BETTER AGREEMENT TODAY IN THE LARGE SCALE FLOW
ACROSS THE CONUS FOR THE SECOND HALF OF THE WORK WEEK. MOST
OPERATIONAL AND ENSEMBLES MODELS NOW AMPLIFY A STRONG SHORTWAVE
TROUGH DIVING INTO THE CNTRL US ON WED. THIS DRIVES A STRONG COLD
FRONT THROUGH THE FA ON WED. WE WILL CONT WITH THE CHC OF SHOWERS
FOR LATE TUE NIGHT IN THE NORTH...SPREADING ACROSS A GOOD PART OF
OUR FA FOR WED. WE MAY SEE THE SHOWERS SHUT OFF FOR A TIME ON WED
NIGHT AS THE MID LEVEL DRY-SLOT WORKS THROUGH THE FORECAST AREA. BUT
THE WRAP-AROUND/DEFORMATION ZONE LOOKS TO IMPACT AT LEAST OUR
NORTHERN AND ERN FA THU AND THU NIGHT WITH CHC POPS IN THE FORECAST.
IT APPEARS THEN THAT THIS PERIOD OF THE FORECAST WILL SEE WELL BELOW
NORMAL TEMPERATURES FOR HIGHS...ESPECIALLY ON THU WHERE HIGHS MAY
NOT GET OUT OF THE MID 40S WITH BREEZY CONDITIONS. WILL LEAVE THE
LATER HALF OF FRI AND INTO SAT DRY ATTM WITH SOME MODERATION TO
TEMPERATURES.
BOUSTEAD
&&
.AVIATION...
18Z TAFS FOR KOFK...KLNK AND KOMA.
A TRICKY AND MESSY TAF FORECAST TO DEAL WITH AT ALL THREE TAF
SITES THIS PACKAGE. EAST NEBRASKA AND WEST IOWA IS BETWEEN A WARM
FRONT THAT LIFTED NORTH ACROSS THE AREA THIS MORNING...AND AN
APPROACHING COLD FRONT FROM THE WEST THAT WILL IMPACT TAF SITES
AROUND 00Z TO 03Z. UNTIL THE FRONT ARRIVES WILL BE JUMPING IN AND
OUT OF MVFR CIGS. WHEN THE FRONT ARRIVES IT WILL BRING A CHANCE OF
THUNDERSTORMS. EXPECT MOST TSRA ACTIVITY TO CLEAR THE AREA AFTER
03Z WITH TREND TO MVFR AND VFR THROUGH THE REMAINDER OF THE
FORECAST.
MEYER
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
655 PM EDT SAT OCT 13 2012
.SYNOPSIS...
CLOUDS WILL CONTINUE TO THICKEN OVER THE AREA THROUGH LATE EVENING
WITH RAIN DEVELOPING...FIRST ACROSS NEW YORK STATE AND EVENTUALLY
INTO NORTHERN PENNSYLVANIA AFTER MIDNIGHT. RAIN WILL REMAIN LIKELY
OVERNIGHT AS A WARM FRONT MOVES THROUGH. BEHIND THE WARM FRONT A
FEW SHOWERS WILL BE POSSIBLE ACROSS CENTRAL NEW YORK
SUNDAY...OTHERWISE IT WILL BE BREEZY AND WARM WITH HIGHS NEAR 70.
A COLD FRONT WILL CROSS THE REGION MONDAY WITH SHOWERS ALONG WITH
A RETURN TO COOLER WEATHER.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
RADARS SHOW LIGHT RETURNS ACROSS MUCH OF NORTHERN NEW YORK IN
RESPONSE TO INCREASING ISENTROPIC LIFT AND MOISTURE ADVECTION.
MUCH OF THIS WAS VIRGA AT PRESENT. THIS ISEN LIFT/MOISTURE
ADVECTION WAS IN ADVANCE OF A SHORT WAVE RIPPLING THROUGH NORTHERN
ONTARIO. THIS FEATURE WAS INCREASING UPPER CONFLUENCE TO OUR
NORTHEAST ENHANCING THE THERMALLY DIRECT JET STREAK CIRCULATION
FOR NY AND PA. THIS WAS ALLOWING FOR THE STRGR ISEN LIFT AND
PRECIPITATION TO BREAK OUT. BY AROUND 9Z...THIS WAVE PASSES AND THE
WAA IMPULSE WILL WEAKEN AND THE MORE WIDESPREAD RAINS WILL TAPER
TO SCATTERED SHOWERS/SPRINKLES. THIS OCCURS AT THE SAME TIME THAT
THE STRONGER UPPER LEVEL LOW AND ASSOCIATED SURFACE CYCLONE IN THE
PLAINS INTENSIFIES AND INCREASES THE DOWNSTREAM RIDGING ALOFT
OVER THE EAST. THIS WILL ALLOW THE WARM FRONT TO EVENTUALLY PUSH
NORTH OF THE REGION SUNDAY LATER IN THE MORNING AS THE ISENTROPES
WILL EASILY BE ADVECTED NORTH AND NOT BE HELD UP BY A JET STREAK
AND ASSOCIATED GEOSTROPHIC ADJUSTMENTS.
LATEST HRRR HAD THE BEST HANDLE ON THE RADAR ECHOES AT THIS TIME IN
OHIO WHICH WAS MUCH FARTHER SOUTH THAN THE NAM...GFS...AND OTHER
CONVECTION ALLOWING HIGH RES MODELS. SINCE THIS MODEL SEEMS TO HAVE
INITIALIZED WELL AND THE PRECIP IS FARTHER S...I WENT ALONG WITH
THE IDEA OF HAVING MORE PRECIP SLIDE ACROSS NRN PA IN LINE WITH
THE LATEST HRRR LATER TONIGHT. I RAISED POPS IN NE PA FOR LATER TONIGHT
AS A RESULT. OTHERWISE JUST SOME TWEAKS TO AN EXCELLENT FORECAST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/...
330 PM UPDATE...
STRONGEST LIFT MOVES NORTHEAST AS A WARM FRONT LIFTS INTO NNY SUNDAY.
WILL DECREASE POPS FROM SOUTHWEST TO NORTHEAST EARLY...AND
MAINTAIN CHANCE POPS THROUGH THE AFTERNOON ONLY ACROSS NORTHERN
ONEIDA COUNTY. WE WILL REMAIN BREEZY THROUGH EARLY
AFTERNOON...AGAIN WITH THE HIGHER WINDS OVER THE HIGHEST TERRAIN.
WE LOOK FAIRLY DRY THROUGH SUNDAY NIGHT WITH POPS INCREASING
TOWARD DAYBREAK MONDAY AS A COLD FRONT ENTERS THE WESTERN PART OF
THE CWA.
NOT OVERLY IMPRESSED WITH THE FRONTAL PASSAGE MONDAY AND WILL KEEP
POPS IN THE CHANCE RANGE. BY AFTERNOON MOST OF THE CWA SHOULD BE
DRY WITH THE EXCEPTION OF THE FAR SOUTHEAST AS SOME MOISTURE MOVES
UP THE COAST. A TROF MOVES THROUGH MONDAY NIGHT WITH A FEW
SHOWERS. WITH 850S IN THE 0C TO -2C RANGE TUESDAY ON A NORTHWEST
FLOW LAKE SHOWERS WILL BE AROUND BUT STRONG NVA ON THE BACKSIDE OF
THE UPPER TROF WILL LIMIT THE POTENTIAL TO JUST SLIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
330 PM UPDATE...
MAIN FEATURE OF NOTE TO WATCH DURING THIS EXTENDED PERIOD WILL BE AN
UPPER LEVEL CLOSED LOW MOVING SLOWLY EAST FROM THE MIDWEST. MODEL
TRENDS HAVE BEEN TO SLOW THIS FEATURE DOWN WITH TIME. LATEST GFS AND
12Z ECMWF INDICATE THAT THIS SYSTEM MAY NOT BRING ANY RAIN TO OUR
AREA UNTIL FRIDAY. BASED ON THIS WILL GO WITH A DRY MILD FORECAST
WEDNESDAY THROUGH THURSDAY WITH ABOVE NORMAL HIGHS MAINLY IN THE MID
TO UPPER 60S AND LOWS IN THE 40S TO LOWER 50S. WILL BRING HIGH
CHANCE POPS ACROSS THE AREA FRIDAY AND CONTINUED MILD WITH HIGHS
MAINLY IN THE 60S. THE WEEKEND LOOKS COOLER AND CONTINUED UNSETTLED
WITH A CHANCE OF SHOWERS AS THE CLOSED LOW MOVES EAST ACROSS THE
AREA.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL CONTINUE INTO THIS EVENING WITH SOUTHERLY
WINDS INCREASING TO 5 TO 15 KTS. RAIN WILL SPREAD ACROSS CENTRAL
NY THIS EVENING WITH AREAS OF MVFR CIGS AND VSBYS DEVELOPING. THE
HEAVIEST STEADIEST RAIN WILL BE AT AT SYR AND RME. FARTHER SOUTH
JUST A FEW SHOWERS ARE EXPECTED... ALONG WITH AREAS OF MVFR VSBYS
AND CIGS. SOUTH-SOUTHWEST WINDS WILL INCREASE TO 10 TO 20 KTS WITH
A FEW GUSTS TO 25 KTS OVERNIGHT.
CONDITIONS WILL SLOWLY IMPROVE ON SUNDAY WITH CONDITIONS BECOMING
MOSTLY VFR DURING THE AFTERNOON. SOUTHWEST WINDS AT 10 TO 20 KTS
WILL CONTINUE WITH A FEW GUSTS TO 25 KTS THROUGH THE DAY.
OUTLOOK...
SUN NGT/MON/TUE...MVFR IN SHRA.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...HEDEN
LONG TERM...MSE
AVIATION...MSE
AREA FORECAST DISCUSSION
NWS NORMAN OK
345 PM CDT SAT OCT 13 2012
...SEVERE THUNDERSTORMS EXPECTED THROUGH 1 AM CDT TONIGHT
SOUTHEAST OF A CHEROKEE TO QUANAH LINE...
.DISCUSSION...
THE MAIN CONCERN IS ONGOING SEVERE THUNDERSTORMS.
CURRENT STORMS NEAR A SEYMOUR TO EL RENO LINE HAVE DEVELOPED JUST
AHEAD AND EAST OF THE DRYLINE. GENERALLY THINK THESE STORMS WILL
CONGEAL INTO ONE MAIN LINE BY 7 PM CDT NEAR AN ARCHER CITY TO ADA
LINE AND QUICKLY MOVE EAST...LIKELY EXITING ATOKA AND BRYAN
COUNTIES BY 1 AM CDT. THINK THE LATEST HRRR RUNS HANDLE THIS
WELL.
THE MAIN HAZARD IS DAMAGING WINDS UP TO 70 MPH...ESPECIALLY ONCE
STORMS FORM INTO ONE MAIN LINE. A COLD POOL OF AIR SEEMS TO BE
DEVELOPING WITH THE LINE OF STORMS FROM FREDERICK TO EL RENO
WHICH WILL ONLY GET STRONGER OVER THE NEXT FEW HOURS. NOT TO
MENTION...FORCING FROM THE APPROACHING MID/UPPER LOW/TROUGH OVER
WESTERN KANSAS AND THE PANHANDLES WILL ALLOW THE LINE OF STORMS
TO GROW AND PERHAPS ACCELERATE OVER THE NEXT SEVERAL HOURS.
THERE IS A POTENTIAL FOR TORNADOES AND LARGE HAIL UP TO GOLF
BALLS WITH DISCRETE SUPERCELLS AHEAD OF THE MAIN DEVELOPING
LINE...WHICH APPEARS TO BE MOST LIKELY SOUTHEAST OF A KNOX
CITY TO OKLAHOMA CITY TO CHANDLER LINE. LOW LCLS WITH SURFACE
DEWPOINTS AROUND 70 DEGREES...50-100 J/KG 0-3KM MLCAPE...AND
0-1 KM SRH 150 TO 300 M2/S2 SUPPORT LOW LEVEL ROTATING
SUPERCELLS. ANY SUPERCELLS WILL MOVE NORTHEAST AROUND
50 MPH.
ALL SEVERE STORMS WILL END BY 1 AM CDT TONIGHT.
BEYOND TONIGHT...GENERALLY DRY AND QUIET WEATHER WILL
PREVAIL. DID NOT CHANGE ANYTHING BEYOND SUNDAY.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 52 80 53 83 / 70 0 0 0
HOBART OK 51 82 51 82 / 10 0 0 0
WICHITA FALLS TX 55 83 54 86 / 70 0 0 0
GAGE OK 48 81 43 86 / 10 0 0 0
PONCA CITY OK 53 79 48 81 / 40 0 0 0
DURANT OK 60 82 54 84 / 100 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
06/17
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
353 PM CDT SAT OCT 13 2012
.AVIATION...
355 PM
WILL BACK UP TSRA TIMING WITH 21Z AMENDMENTS. PER HRRR AND TX
TECH WRF...FEEL NOW THAT TSRA LINE WILL LIKELY MAKE SLOW EASTWARD
PROGRESS UNTIL COLD FRONT CATCHES UP WITH THE DRY LINE/TROUGH.
CANNOT RULE OUT CONVECTION AHEAD OF LINE...BUT CURRENT
CLOUD/SHOWER ACTIVITY HAS LIMITED HEATING...CURRENTLY ABOUT 2-3
DEGREES BELOW CONVECTIVE TEMPERATURE WITH MAX HEATING ALREADY
BEHIND US AND CLOUD COVER STILL FAIRLY EXTENSIVE. WEAK FORCING
MAY WEAKEN THE INVERSION ENOUGH FOR A FEW TSRA TO FORM THIS
EVENING AHEAD OF THE LINE. 84
&&
.PREV DISCUSSION... /ISSUED 303 PM CDT SAT OCT 13 2012/
SHORTWAVE THIS MORNING NOW TRACKING NORTHEAST ACROSS THE AREA AND
HAS PRODUCED SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS MAINLY
ALONG AND WEST OF INTERSTATE 35W/35E. WITH A RELATIVELY STRONG
CAP THIS MORNING...THIS FIRST DISTURBANCE WILL ACT AS SOMEWHAT OF
A PRIMER TO LIFT AND WEAKEN THE CAP IN ADVANCE OF THE LARGE SCALE
ASCENT THAT IS NOW ENTERING NORTHWEST TEXAS. A PRE-FRONTAL TROUGH
FROM JUST WEST OF WICHITA FALLS TO NEAR SWEETWATER WAS BECOMING
ACTIVE THIS AFTERNOON WITH A FEW SUPERCELLS DEVELOPING IN THE
VICINITY OF HASKELL AS OF THE PAST HOUR. WE EXPECT THE PACIFIC
COLD FRONT FURTHER WEST OVER THE TEXAS PANHANDLE TO EVENTUALLY
OVERTAKE THE PRE-FRONTAL TROUGH THROUGH THIS AFTERNOON WITH
INCREASING STORMS ACROSS OUR FAR WESTERN COUNTIES BY MID-LATE
AFTERNOON. CONVECTIVE TEMPERATURE IS AROUND 85 DEGREES PER THIS
MORNINGS FWD SOUNDING AND AMDAR VAPOR AND WE ARE JUST A FEW
DEGREES BELOW THAT. WITH THIS ALL IN MIND...OUR FIRST WATCH OF
THE DAY HAS BEEN ISSUED ACROSS OUR NORTHWEST COUNTIES. TORNADO
WATCH 661 IS IN EFFECT UNTIL 9 PM NORTHWEST OF AN
EASTLAND...MINERAL WELLS...SAINT JO LINE.
WE DO EXPECT THE SEVERE WEATHER THREAT TO RAMP UP ACROSS THE
WESTERN HALF OF NORTH TEXAS IN THE 4-7 PM TIME FRAME...AS THE
LARGE SCALE ASCENT APPROACHES FROM THE WEST. WITH MORE OF A CAP
TO ERODE ACROSS NORTH TEXAS VERSUS OKLAHOMA...ITS LIKELY THE
STORM MODE WILL BE MORE CELLULAR INITIALLY VERSUS A SOLID SQUALL
LINE THAT IS EXPECTED FURTHER TO THE NORTH. MLCAPE NOW ACROSS THE
WESTERN COUNTIES IS 1000-1500 J/KG WITH 0-3KM/0-1KM HELICITIES
RANGING FROM 150-300 M2/S2 ACROSS THE WATCH AREA. THROW IN 0-6KM
BULK SHEAR ON THE ORDER OF 45-50KTS INDICATES THAT WIND FIELDS
WILL BE MORE THAN ENOUGH FOR THE ORGANIZATION OF STRONG TO SEVERE
STORMS. INITIAL THREATS INTO EARLY EVENING WILL BE LARGE HAIL...
DAMAGING WINDS AND THE POSSIBILITY OF A TORNADO WITH CELLS
REMAINING DISCRETE. BY MID EVENING... A 40-50 KT LLJ WILL LIKELY
CONGEAL STORMS INTO A LINEAR MCS...WHICH WILL MOVE SOUTH AND EAST
OVERNIGHT AND SLOW DOWN. WE THINK THE GREATEST SEVERE WEATHER
RISK WILL REMAIN ACROSS THE NORTHWEST HALF OF THE CWA...THEN
BECOME MORE LOCALIZED WITH A POSSIBLE INCREASING HYDROLOGICAL
SITUATION FOR OUR SOUTHEAST HALF OF THE CWA OVERNIGHT AND EARLY
SUNDAY MORNING...THOUGH A VEERING LLJ OVERNIGHT SHOULD KEEP ANY
FLOODING MINOR AND LOCALIZED.
WE EXPECT THE PACIFIC FRONT TO CONTINUE ITS SOUTHEAST MIGRATION
THROUGH THE MORNING HOURS SUNDAY AND LIKELY ENDING RAIN CHANCES
ACROSS OUR CENTRAL AND SOUTHEAST TEXAS COUNTIES BY EARLY
AFTERNOON. DRY AIR WILL THEN INFILTRATE INTO THE AREA BY SUNDAY
EVENING AND INTO THE FIRST HALF OF THE WORK WEEK WITH HIGHS IN
THE 80S AND LOWS IN THE 50S AND LOWER 60S. A WEAK SOUTHERN BRANCH
SHORTWAVE TROUGH WILL MOVE ACROSS SOUTH TEXAS LATE TUESDAY INTO
WEDNESDAY...BUT NOTHING IS EXPECTED ACROSS NORTH TEXAS OUTSIDE OF
INCREASING SOUTH WINDS AND SOME MODIFIED MOISTURE RETURN BACK
NORTH ACROSS MAINLY EAST TEXAS AND THE LOWER MISSISSIPPI VALLEY.
ACCOMPANYING COLD FRONT WILL ARRIVE WEDNESDAY NIGHT INTO THURSDAY
AND HAVE PUSHED BEST RAIN CHANCES TO THIS TIME PERIOD MAINLY EAST
OF I-35. SEE ENOUGH FORCING WITH THE FRONT AND LAPSE RATES ALOFT
FOR THE MENTION OF THUNDER WITH THIS FRONT.
FOR THURSDAY AND FRIDAY...AN UPPER LOW DEEPENS OVER THE UPPER
MIDWEST AND GREAT LAKES...HELPING TO KEEP A DRY AND COOL
CONTINENTAL AIRMASS ACROSS NORTH TEXAS. AS THE UPPER LOW MOVES
TOWARD NEW ENGLAND NEXT WEEKEND...WE SHOULD SEE AN UPPER RIDGE
ESTABLISH OVER THE SOUTHERN PLAINS WITH A RETURN OF BREEZY SOUTH
WINDS AND WARMER TEMPERATURES ONCE AGAIN.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 66 84 58 85 60 / 70 5 5 0 5
WACO, TX 69 84 55 84 57 / 70 30 5 5 5
PARIS, TX 65 82 54 83 55 / 60 10 5 0 0
DENTON, TX 62 83 52 85 55 / 70 5 0 0 5
MCKINNEY, TX 65 83 52 84 55 / 60 10 5 0 0
DALLAS, TX 67 83 59 86 61 / 60 10 5 0 5
TERRELL, TX 68 83 55 86 57 / 60 20 5 0 5
CORSICANA, TX 69 84 57 84 58 / 70 30 5 5 5
TEMPLE, TX 70 83 56 85 59 / 70 40 5 5 5
MINERAL WELLS, TX 58 86 54 84 55 / 70 5 0 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
305 PM CDT SAT OCT 13 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
305 PM CDT SAT OCT 13 2012
MAIN FORECAST CONCERN IS ON RAIN CHANCES THROUGH SUNDAY.
18Z SURFACE ANALYSIS SHOWS BROAD AREA OF LOW PRESSURE OVER THE
PLAINS...WITH A WARM FRONT DRAPED ACROSS NORTHERN AND EASTERN IOWA.
HIGHER DEW POINT AIR FOUND ALONG AND SOUTH OF THIS BOUNDARY FROM
IOWA SOUTHWARD. AREA RADAR SHOWS HEAVIEST PRECIPITATION OVER EASTERN
WISCONSIN...WITH A DEFORMATION AREA OF LIGHTER RAIN NORTH OF
INTERSTATE 90.
13.12Z MODELS OVERALL OFFER SIMILAR SOLUTIONS...WITH JUST SOME MINOR
DETAIL DIFFERENCES IN CLEARING THE RAIN OUT ON MONDAY.
IN THE NEAR TERM...MAIN WAVE LOOKS TO LIFT EAST-NORTHEAST TONIGHT
INTO ILLINOIS. WITH THE LOW CLOUDS LIMITED INSTABILITY EXPECTED OVER
THE AREA AND THUS SEVERE WEATHER THREAT HAS SHIFTED FURTHER SOUTH
OUT OF THE AREA. LOW LEVEL FRONTOGENESIS STRENGTHENS THIS EVENING
ACROSS NORTHEAST IOWA INTO SOUTHWEST WISCONSIN AND WAVE LIFTS
TOWARDS THE AREA. EXPECT MAIN DEFORMATION OF RAIN TO RE-DEVELOP
ACROSS THE AREA...WITH THE HIGHEST PROBABILITIES AND QPF FROM
NORTHEAST IOWA INTO SOUTHWEST WISCONSIN. 13.15Z HRRR WOULD SUGGEST
NOT A LOT OF RAIN THROUGH 03Z...WITH ONLY SOME LIGHT DRIZZLE OR
LIGHT RAIN. WILL ADD MENTION OF FOG THROUGH THE EARLY EVENING HOURS
BEFORE MORE WIDESPREAD RAIN MOVES IN AFTER 03Z. 13.18Z RAP AND 13.12Z
NAM AND GFS ALL SHOWING JUST 200-300 J/KG OF MOST UNSTABLE CAPES
THIS EVENING AND THUS DID KEEP SCATTERED THUNDER IN THE FORECAST.
WAVE ROTATES THROUGH ILLINOIS EARLY SUNDAY MORNING AND INTO LOWER
MICHIGAN BY AFTERNOON. DEFORMATION PRECIPITATION AREA TO REMAIN OVER
THE FAR SOUTHERN COUNTIES THROUGH THE MORNING HOURS...WITH THE
PRECIPITATION THEN LIFTING TO THE EAST IN THE AFTERNOON. STILL
EXPECTING ANOTHER INCH OR SO OF RAINFALL FOR PORTIONS OF SOUTHWEST
WISCONSIN AND NORTHEAST IOWA THROUGH SUNDAY.
UPPER LEVEL RIDGING THEN BUILDS INTO THE REGION FOR SUNDAY NIGHT
INTO MONDAY. EXPECT THE CLOUDS TO BEGIN CLEARING OUT FROM WEST TO
EAST SUNDAY AFTERNOON...WITH CLEAR SKIES EXPECTED SUNDAY NIGHT. WITH
THE SURFACE HIGH DROPPING SOUTH THROUGH THE CENTRAL
PLAINS...SOUTHERLY WINDS ON MONDAY WILL PULL SOME WARMER AIR
NORTHWARD...WITH TEMPERATURES EXPECTED TO BE ABOVE NORMAL...PERHAPS
HITTING 70 DEGREES OVER SOUTHEAST MINNESOTA AND NORTHEAST IOWA.
THE NEXT WAVE THEN BEGINS TO DROP THROUGH THE NORTHERN PLAINS
MONDAY NIGHT INTO TUESDAY. SOUTHERLY WINDS WILL KEEP THE
TEMPERATURES UP MONDAY NIGHT WITH THE FRONT THEN APPROACHING THE
AREA TUESDAY. UPPER WAVE LOOKS TO TRACK ACROSS NORTHERN WISCONSIN
TUESDAY AND ALTHOUGH NOT A LOT OF MOISTURE TO WORK WITH...COULD SEE
A FEW SHOWERS AND THUS LOWER END PROBABILITIES LOOK REASONABLE.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
305 PM CDT SAT OCT 13 2012
THIS PERIOD LOOKS TO BE DOMINATED BY A DIGGING TROUGH ACROSS THE
NORTHERN PLAINS INTO THE GREAT LAKES REGION. BOTH THE 13.12Z ECMWF
AND GFS BOTH CARVE THIS UPPER LOW OUT IN THE WEDNESDAY/THURSDAY TIME
FRAME...BUT THEN DIVERGE IN THEIR SOLUTIONS BEYOND THURSDAY. GFS
MORE PROGRESSIVE IN OPENING THE WAVE UP AND PUSHING IT EASTWARD
FRIDAY/SATURDAY...WHILE THE ECMWF SPINS THE UPPER LOW OVER THE UPPER
MIDWEST/GREAT LAKES REGION INTO SATURDAY. GIVEN THESE UNCERTAINTIES
FEEL THAT PROBABILITIES ARE WARRANTED THROUGH THE ENTIRE PERIOD.
TEMPERATURES LOOK TO BE AT OR BELOW NORMAL FOR MUCH OF THE TIME
PERIOD.
&&
.AVIATION...THROUGH SUNDAY MORNING
101 AM CDT SAT OCT 13 2012
FOR THIS AFTERNOON...KRST WILL HAVE LIFR CEILINGS AND DENSE FOG
THROUGH 13.21Z AND THEN THE CEILINGS AND VISIBILTIES WILL IMPROVE
A BIT. THERE WILL ALSO BE SOME DRIZZLE/LIGHT RAIN DURING THIS
TIME. KLSE WILL HAVE IFR CEILINGS AND MVFR VISIBILITIES.
FOR TONIGHT...A LOW PRESSURE SYSTEM WILL MOVE NORTHEAST FROM
EASTERN KANSAS TO NORTHERN ILLINOIS. AS THIS LOW PRESSURE SYSTEM
APPROACHES ANOTHER ROUND OF SHOWERS AND SCATTERED THUNDERSTORMS
WILL MOVE INTO THE AREA BETWEEN 14.00Z AND 14.03Z...AND THEN
LINGER INTO SUNDAY MORNING. THE THUNDERSTORM THREAT LOOKS TOO
SMALL TO BE MENTIONED IN THE TAFS. SOUNDINGS SUGGEST THAT THE LOW
LEVELS WILL BE SATURATED SO EXPECT LIFR/IFR CEILINGS TONIGHT.
VISIBILITIES WILL BE RESTRICTED 3 MILES OR LESS MAINLY DUE TO THE
MIST/FOG.
ON SUNDAY MORNING...AS THE LOW PRESSURE SYSTEM SLOWLY PULLS AWAY
FROM THE AREA. BOTH THE CEILINGS AND VISIBILITIES WILL SLOWLY IMPROVE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
305 PM CDT SAT OCT 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION...BOYNE