Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/19/13
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
349 PM EDT THU OCT 17 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM AND SLOW MOVING COLD FRONT WILL CROSS THE
REGION OVERNIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THE SYSTEM FOR
FRIDAY AND REMAIN OVER THE AREA INTO SATURDAY. ANOTHER DISTURBANCE
WILL AFFECT THE AREA SATURDAY NIGHT AND EARLY SUNDAY. MORE HIGH
PRESSURE FROM THE OHIO VALLEY WILL BUILD IN SUNDAY AND REMAIN
THROUGH THE EARLY PART OF NEXT WEEK. ANOTHER DISTURBANCE MAY AFFECT
THE AREA TOWARDS THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE GFS INITIALIZATION LOOKED SLIGHTLY BETTER THAN THE WRF-NMMB, BUT
BOTH MODELS WERE PRETTY CLOSE AND SO IS THEIR SOLUTION FOR TONIGHT.
A STRONG NEGATIVE TILT SHORT WAVE IS PREDICTED TO PASS MAINLY
NORTHWEST OF OUR CWA WITH THE NORTHWEST PART OF OUR CWA GETTING INTO
THE EXIT REGION OF THE JET AND CLOSEST PROXIMITY TO THE LLJ. ITS ALSO
THE BEST LOCALE FOR THE MID LEVEL QVEC CONVERGENCE. ELSEWHERE, A
WEAKER SHORT WAVE GENERATING LIGHTER SHOWERS WILL MOVE ACROSS THE
SOUTHEAST PART OF OUR CWA. THIS MUDDIES THE POP GRADIENT WITH WHAT
IS ASSOCIATED WITH THE PRIMARY NEGATIVE TILT SHORT WAVE. THERE ALSO
MAY BE A POP OR QPF MINIMUM RIGHT ALONG THE I95 CORRIDOR.
WE HAVE MAINTAINED HIGHEST POPS NORTHWEST AND ADDED A LOW CHANCE OF
THUNDER. THUNDER SHOULD BE ONGOING AS OF 3 PM OVER THE APPALACHIANS
AND IT WAS NOT. WE THUS DREW A LINE WHERE THERE WAS COMPLETE
MODEL CONSENSUS AND DID NOT GO WITH THE MORE AGGRESSIVE THUNDER
SOLUTIONS. THE MODELS ARE INCREASING THE ELEVATED CONVECTION AS
THE 500MB TEMPS ARE FORECAST TO COOL (850MB REMAINS ABOUT THE
SAME). THIS IS DONE MOST EFFICIENTLY FAR NW AND IS LOCATION WHERE
SOME HRRR RUNS TODAY HAVE BEEN FORECASTING A NARROW BAND OF
SHOWERS AND TSTMS. GIVEN THE ARRIVAL TIME AND THE EXPECTED
FORMATION OF A PCPN INDUCED INVERSION BASED ON FCST SIMULATED
RADARS, SUSPECT THE WINDS WILL STRUGGLE SOMEWHAT TO MIX DOWNWARD.
BUT, ONCE THE FRONT CLEARS (NOW LOOKS FASTER BETWEEN 03Z AND 06Z),
THE WRF-NMMB IS FORECASTING A PERIOD OF MIXING AS THE SOUNDING
DOES BECOME MORE ADIABATIC. WE HAVE MAINTAINED THE GUSTY MENTION
(ALSO IN TAFS) FOR A COUPLE OF HOURS POST COLD FRONTAL.
GIVEN THE LATTER, WE ARE NOT EXPECTING MUCH FOG TO FORM AND ALSO THE
MIXING SHOULD KEEP MIN TEMPERATURES FROM TANKING. STAT GUIDANCE
LOOKS REASONABLE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
A MORE FALL LIKE DAY ON FRIDAY, MORE SO DUE TO THE LOWER DEW POINTS
THAN A PRECIPITOUS DROP IN TEMPERATURES. A BREEZY MORNING IS
EXPECTED WITH WINDS SLOWLY DECREASING AS THE AFTERNOON PROGRESSES.
THE KATABATIC FLOW AND DECREASE IN WINDS SHOULD GET US CLOSE TO
ADIABATIC O 850MB MAKING STAT GUIDANCE MAX TEMPS LOOK QUITE
REASONABLE. FCST SOUNDINGS DO BRING THE CONVECTIVE TEMPERATURE
CLOSE NORTHWEST AND COUPLED WITH BETTER CONDITIONS FOR CUMULUS IN
NY/PA, EXPECT SOME TO WORK THEIR WAY INTO OUR CWA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A MUCH MORE AMPLIFIED UPPER PATTERN IS BEGINNING TO DEVELOP ACROSS
NORTH AMERICA AND THE ATLANTIC. THIS WILL RESULT IN MORE
FREQUENT...BUT QUICKER MOVING WEATHER SYSTEMS ACROSS THE AREA. AT
THE BEGINNING OF THE LONG TERM...A HIGH PRESSURE SYSTEM WILL BE
ACROSS OUR AREA WITH FAIR WEATHER EXPECTED FRIDAY AND MUCH OF
SATURDAY. AFTER A COOL MORNING SATURDAY...TEMPERATURES LATER
SATURDAY WILL CLIMB ABOVE NORMAL WITH UPPER 60S/LOW 70S EXPECTED
ACROSS THE AREA. MUCH OF SATURDAY WILL BE DRY BUT THERE WILL BE A
SLIGHT CHC FOR A SHOWER DURING THE AFTERNOON. CLOUDS WILL BE
THICKENING ACROSS THE AREA.
AN UPPER DISTURBANCE AND SFC COLD FRONT WILL CROSS THE REGION
SATURDAY NIGHT AND MOVE TO THE EAST BY SUNDAY MORNING. THE SYSTEM IS
NOT VERY ORGANIZED AND THEREFORE WE WILL KEEP THE 30 POPS FOR MUCH
OF THE AREA. PCPN SHOULD AMT TO LESS THAN A TENTH OF AN INCH ACROSS
THE AREA. COLDER AIR AND HIGH PRESSURE WILL FOLLOW FOR SUN AND MON
WITH TEMPERATURES ABOUT 5 DEGREES BELOW NORMAL SUNDAY AND A BIT
CLOSER TO NORMAL MON. DRY WEATHER EXPECTED SUN AND MON.
TEMPERATURES WILL WARM BACK TO ABOVE NORMAL NEXT TUE...BUT THIS IS
JUST IN TIME FOR THE NEXT SYSTEM WHICH IS SLATED TO ARRIVE EITHER
TUE NIGHT OR WED. WE HAVE GONE ALONG WITH THE WPC POPS/WX FOR THIS
SYSTEM WITH SLGT CHC POPS FOR TUE NIGHT AND DRY FOR WED. MUCH COOLER
AIR WILL ARRIVE BEHIND THE SYSTEM FOR LATE NEXT WEEK.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
18Z TAFS FORECASTING SOME MVFR CONDITIONS WITH THE LIKELIHOOD OF
SHOWERS CENTERED ON THIS EVENING.
FOR THE REST OF THIS AFTERNOON THE LOW CIGS ARE JUST ABOUT GONE.
VFR CIGS OUTSIDE OF SHOWERS. SOUTH TO SOUTHWEST WINDS SHOULD AVERAGE
5 TO 10 KTS. SEA BREEZE FRONT HAS FORMED IN EASTERN COUNTIES OF NJ
AND SHOULD REMAIN NEARLY STATIONARY.
FOR THIS EVENING, THIS SHOULD BE THE GREATEST LIKELIHOOD FOR
SHOWERS FOR ALL THE TERMINALS. THE HIGHEST AND MOST CONFIDENT MVFR
CIG AND VSBY IMPACTS SHOULD BE AT KRDG AND KABE. THERE IS ALSO A
LOW CHANCE OF THUNDER FOR PA AIRPORTS, NOT CONFIDENT TO INCLUDE
ATTM.
ONCE THE CDFNT MOVES THROUGH, VFR CIGS OR VFR NO CIGS EXPECTED
WITH NO VSBY RESTRICTIONS. FORECASTS SOUNDINGS SUGGEST THERE COULD
BE A COUPLE OF HOURS OF GUSTY WEST WINDS FOLLOWING THE CFP. PEAK
GUSTS OF AROUND 25 KT ARE POSSIBLE.
THEN ON FRIDAY MORNING INTO EARLY AFTERNOON VFR CONDITIONS WITH NO
CIGS ARE FORECAST. SOME GUSTINESS SHOULD RETURN WITH WEST TO
NORTHWEST WINDS AVERAGING 10 TO 15 KT AND PEAK GUSTS OF 20 TO 25
KT.
OUTLOOK...
FRIDAY NIGHT - SATURDAY...VFR WITH WEST-NORTHWEST WINDS GUSTING
INTO THE LOW-20S ON FRIDAY. LESS WIND ON SATURDAY.
SATURDAY NIGHT - SUNDAY...POSSIBLE MVFR OR LOWER IN SCATTERED
SHOWERS.
MONDAY - TUESDAY...VFR WITH POSSIBLE LATE DAY SHOWERS ON TUESDAY.
&&
.MARINE...
THE SCA ADVISORY REMAINS IN EFFECT INTO FRIDAY AFTERNOON FOR ALL OF
OUR MARINE AREA EXCEPT UPPER DELAWARE BAY. WE BUMPED UP THE STARTING
TIME SLIGHTLY TONIGHT AS PER SLIGHTLY FASTER UPTICK IN WINDS. STRONG
WINDS SHOULD START CLOSE TO THE ARRIVAL OF THE CDFNT AND THEN
PERSIST IN TWO WAVES INTO FRIDAY MORNING. WINDS SHOULD DECREASE
BELOW SMALL CRAFT ADVISORY CRITERIA FRIDAY AFTERNOON. SINCE MOST OF
THE SEAS WILL BE WIND GENERATED, THEY SHOULD ALSO DROP OFF BELOW
SMALL CRAFT ADVISORY CRITERIA AS SOON AS WINDS DIMINISH.
OUTLOOK...
THERE IS A CHANCE FOR SMALL CRAFT ADVISORY CONDITIONS IN THE CAA
FLOW BEHIND THE NEXT COLD FRONT ON SUNDAY. OTHERWISE WIND AND
SEAS ARE EXPECTED TO REMAIN BELOW SCA CONDS FOR THE REMAINDER OF
THE OUTLOOK PD.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 2 PM EDT
FRIDAY FOR ANZ431-450>455.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI
SHORT TERM...GIGI
LONG TERM...O`HARA
AVIATION...GIGI/HEAVENER/O`HARA
MARINE...GIGI/O`HARA
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
720 PM EDT FRI OCT 18 2013
.UPDATE (TONIGHT AND SATURDAY)...
23Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS MUCH OF THE CONUS
UNDERNEATH THE INFLUENCE OF DEEP AND BROAD LONGWAVE TROUGHING. THE
TROUGH AXIS IS CURRENTLY PIVOTING EASTWARD FROM A POSITION EXTENDING
FROM THE UPPER MS VALLEY TO THE SOUTHERN PLAINS. THIS SOUTHERN
"LOBE" OF ENERGY ALOFT OVER THE SOUTHERN PLAINS WILL SWING ACROSS
THE DEEP SOUTH DURING THE NEXT 24 HOURS AND HELP TO SUPPRESS
SOUTHWARD THE UPPER RIDGE THAT HAS DOMINATED OUR WEATHER THE PAST
FEW DAYS. AT LEAST FOR NOW...THE RIDGE IS STILL HOLDING STRONG OVER
THE FL PENINSULA WITH THE DEEPER MID/UPPER LEVEL MOISTURE SHOWN BY
WV IMAGERY STREAMING OVER THE CENTRAL/NE GULF COAST. SOME OF THIS
DEEPER MOISTURE WILL SHIFT SOUTH WITH TIME AND ALLOW FOR BETTER
CHANCES FOR A FEW SCT SHOWERS TO ENTER THE FORECAST DURING THE
UPCOMING WEEKEND.
AT THE SURFACE...A VERY WEAK GRADIENT REMAINS IN PLACE ACROSS THE FL
PENINSULA THIS EVENING TO THE SOUTH OF A QUASI-STATIONARY FRONTAL
BOUNDARY ACROSS THE FL PANHANDLE/SOUTHERN GA. THE WEAK GRADIENT AND
IMPRESSIVE TERRESTRIAL HEATING FOR MID/LATE OCTOBER ALLOWED FOR WELL
DEFINED SEA-BREEZES ALONG BOTH THE WEST AND EAST COASTS OF THE
STATE. LOW LEVEL CONVERGENCE WAS JUST ENOUGH ALONG OUR WEST COAST
SEA-BREEZE TO FORCE A FEW VERY ISOLATED AND SHALLOW SHOWERS EARLY
THIS EVENING. THE ATMOSPHERE WAS REALLY QUITE HOSTILE TO CONVECTION
TODAY WITH A VERY WELL DEFINED SUBSIDENCE INVERSION AROUND 800MB ON
THE MORNING KTBW SOUNDING PROFILE. THIS SHOWS JUST HOW STRONG THE
LOW LEVEL FOCUS CAN GET ALONG OUR SEA-BREEZE TO OVERCOME THE
NEGATIVE FACTORS. IN FACT...THE HOSTILITY OF THE ATMOSPHERE TO
RISING MOTION AND THE STATIONARY NATURE OF THE FIRST ISOLATED SHOWER
LEAD TO DISCUSSION OF WHETHER OR NOT IT WAS A FIRE BEING DETECTED BY
THE RADAR. HOWEVER... ANALYSIS OF THE VARIOUS DUAL-POL RADAR
PRODUCTS CONFIRMED THAT INDEED THE RADAR WAS SAMPLING METEOROLOGICAL
HYDROMETEORS...AKA...RAINDROPS. GO FIGURE...WHEN FLORIDA WANTS TO
RAIN...IT RAINS.
REST OF TONIGHT AND SATURDAY...SUN HAS SET AND THINGS ARE COOLING
OFF. SEA-BREEZE WILL FOLLOW AND DIMINISH IN NEXT HOUR OR 2 ALLOWING
ANY LINGERING ISOLATED SHOWERS TO DISSIPATE. THE REST OF THE
OVERNIGHT WILL BE GENERALLY DRY AND SEASONABLE FOR OUR LAND AREAS.
THE SLOW LOSS OF THE RIDGE STRENGTH BY LATE TONIGHT ALONG WITH A
WEAK INVERTED TROUGH AND ASSOCIATED SURFACE CONVERGENCE IN THE
SOUTHEAST GULF MAY LEAD TO A FEW SHOWERS OFF THE COAST OF
SARASOTA/CHARLOTTE/LEE COUNTIES LATE TONIGHT INTO THE MORNING
HOURS. DURING THE DAY ON SATURDAY...AS MENTIONED ABOVE...WILL SEE A
SLIGHTLY BETTER CHANCE AT A FEW MAINLY AFTERNOON/EARLY EVENING
SHOWERS AND PERHAPS A THUNDERSTORM. WEAK SURFACE FRONT WILL ENTER
NORTHERN FLORIDA...AND ALONG WITH OVERALL LESS SUPPRESSION AND
ANOTHER WELL-DEFINED WEST COAST SEA-BREEZE...WE SHOULD HAVE SOME
ACTIVITY ON THE RADAR FOR SATURDAY AFTERNOON. DO NOT EXPECT THESE
SHOWERS TO BE ENOUGH TO DO ANYTHING BUT BRIEFLY HALT ANY OUTDOOR
ACTIVITIES. A WET AFTERNOON/EVENING IS CERTAINLY NOT EXPECTED. MOST
OF YOUR SATURDAY WILL BE DRY WITH TEMPERATURES WELL UP INTO THE 80S
TO LOWER 90S. ENJOY!
&&
.AVIATION...
19/00Z-20/00Z. PREVAILING VFR EXPECTED TO CONTINUE ALTHOUGH LAL/PGD
MAY SEE MVFR BR TOWARD SUNRISE. LIMITED SHOWERS SAT WITH JUST VCSH
AFT 18Z OR 20Z. AFTERNOON SEA BREEZE WILL COLLAPSE THIS EVENING TO
LIGHT VARIABLE WINDS OVERNIGHT...SOUTHEASTERLY IN THE MORNING...SW
IN THE AFTERNOON.
&&
.MARINE...
A WEAK GRADIENT WILL PROVIDE LOW WINDS AND SEAS ACROSS THE EASTERN
GULF OF MEXICO THROUGH THE FIRST HALF OF THE WEEKEND. EXPECT WINDS
TO BECOME A BIT MORE STEADY AND TURN ONSHORE DURING SATURDAY
AFTERNOON AND EVENING NEAR THE COAST AS A WELL-DEFINED SEA-BREEZE
BECOMES ESTABLISHED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 74 88 73 88 / 10 30 10 30
FMY 73 90 74 90 / 10 30 10 30
GIF 71 90 70 89 / 10 30 10 30
SRQ 72 87 72 87 / 10 30 10 30
BKV 66 89 64 89 / 10 30 10 30
SPG 76 88 75 87 / 10 30 10 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...MROCZKA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
344 PM EDT THU OCT 17 2013
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
SHORT TERM MODELS IN FAIRLY GOOD AGREEMENT...SHOWING WEAKEN FRONT
WASHING OUT AS IT MOVES ACROSS THE FORECAST AREA THIS AFTERNOON AND
EVENING. LATEST RAP HAS INITIALIZED AREA OF SHOWERS WELL AND NEAR
TERM FORECAST WILL LEAN HEAVILY TOWARD RAP AS SHOWERS DISSIPATE IN
THE ATL AREA BY 4-5PM AND OVER THE GVL-AHN AREA BY THIS EVENING.
WILL GO AHEAD AND DROP MENTION OF THUNDER FROM FORECAST AS
INSTABILITY LIMITED AS WEAK WAVES MOVES ACROSS THE AREA THIS
AFTERNOON AND EVENING AND THE SHOWER ACTIVITY IS PUSHING OUT OF
FORECAST AREA AS THE SHORTWAVE APPROACHES. MODELS BRINGING DRIER AIR
INTO THE AREA THIS EVENING WITH CLEARING SKIES BY MORNING. LATEST
SATELLITE SHOWING CLOUDS CONTINUE BACK INTO PORTIONS OF MISSISSIPPI
AND EXPECT THAT WHILE THERE WILL BE DRYING WE CAN ALSO EXPECT SOME
COOL AREA STRATUS TO DEVELOP AS WELL. WILL COMPROMISE FOR NOW AND
SETTLED ON SCATTERING CLOUDS OUT THIS EVENING BUT DID NOT CLEAR THEM
OUT ALTOGETHER. BASED UPON HOLDING SOME CLOUDS IN HAVE GONE WARMER
THAN GUIDANCE TEMPERATURES BY A DEGREE OR SO OVERNIGHT WITH HIGHS
TOMORROW SLIGHTLY WARMER THAN TODAY.
ATWELL
.LONG TERM /SATURDAY THROUGH THURSDAY/...
NO MAJOR CHANGES MADE TO THE EXTENDED FORECAST. MODELS CONSISTENT
INDICATING THE COLD FRONT WITH BE SE OF THE FORECAST AREA TO START
FRIDAY NIGHT. HOWEVER GFS/NAM/EUROPEAN SOMEWHAT DIFFERENT WITH THE
PLACEMENT OF THE DEEPER MOISTURE AXIS THROUGH THE NIGHT. GFS/NAM
SIMILAR WITH SPREADING DEEPER MOISTURE BACK OVER MAINLY CENTRAL GA
AND THE EUROPEAN IS MORE BROADLY SPREADING MOISTURE ACROSS THE
ENTIRE AREA BY NIGHTS END. ALL IN ALL THIS SEEMS TO KEEP BEST
SHOWER CHANCES ACROSS MAINLY CENTRAL GA. GFS/NAM KEEPS THE BEST
MOISTURE AND SHOWER CHANCES ACROSS CENTRAL GA FOR SATURDAY WHILE
THE EUROPEAN SPREADS MOISTURE AND SHOWER CHANCES ACROSS THE ENTIRE
AREA. EITHER WAY THE BEST CHANCES FOR SHOWERS WILL BE ACROSS
CENTRAL GA AND POSSIBLY PORTIONS OF N GA. THE MOISTURE COMING N
DUE MAINLY TO THE APPROACH OF A SHORT WAVE.
THE MOISTURE WILL HAVE EXITED ALL BUT THE FAR SE CWA TO START SUNDAY
BUT WILL EXIT THAT AREA QUICKLY. SURFACE HIGH PRESSURE MOVES INTO
THE ATLANTIC ON MONDAY WHICH BEGINS TO SPREAD MOISTURE INTO THE FAR
SE CWA WITH SMALL SHOWER CHANCES ASSOCIATED. A WEAK COLD FRONT MOVES
TO THE AREA ON TUESDAY WITH INCREASED SHOWER CHANCES ACROSS THE AREA
TUESDAY/TUESDAY NIGHT. SMALL SHOWER CHANCES WILL BE CONFINED TO THE
FAR SE CWA TO START THE DAY ON WEDNESDAY BEFORE ENDING.
TEMPERATURES WILL BE TRENDING TO A LITTLE BELOW NORMAL FOR MUCH OF
THE EXTENDED PERIOD.
BDL/01
01
&&
AVIATION...
18Z UPDATE...
MVFR CONDITIONS...WITH PATCHY IFR WITH HEAVIER SHRA...WILL
PERSIST UNTIL FRONT PUSHES THROUGH TAF SITES. SHRA WILL CONTINUE
IN ATL AREA SITES UNTIL 20Z BEFORE TAPERING OFF AND BY 00Z IN AHN.
MVFR CIGS BEHIND FRONT WILL SLOWLY SCT OUT OVERNIGHT WITH MODELS
HINTING AT POSSIBLE COOL AIR STRATUS...BUT BELIEVE CLOUDS WILL
REMAIN SCT THROUGH THE PERIOD. WINDS WILL SHIFT MORE W-NW BEHIND
THE FRONT WITH SPEEDS OF 5-10KTS.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM TO HIGH CONFIDENCE ALL ELEMENTS.
ATWELL
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 55 74 55 72 / 40 5 20 20
ATLANTA 56 73 59 71 / 40 5 10 20
BLAIRSVILLE 44 68 48 72 / 40 5 5 10
CARTERSVILLE 49 72 52 75 / 30 5 5 10
COLUMBUS 61 79 61 74 / 20 10 30 30
GAINESVILLE 53 69 56 74 / 40 5 5 20
MACON 59 77 61 74 / 20 10 40 30
ROME 49 73 50 75 / 10 5 5 10
PEACHTREE CITY 54 73 54 72 / 40 5 10 20
VIDALIA 65 82 65 77 / 10 30 50 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ATWELL
LONG TERM....01
AVIATION...ATWELL
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
200 PM EDT THU OCT 17 2013
.PREV DISCUSSION... /ISSUED 1201 PM EDT THU OCT 17 2013/
UPDATE...
ONLY MINOR TWEAKS MADE TO POPS/WEATHER BASED UPON CURRENT RADAR
TRENDS AS WELL AS TEMPERATURES BASED UPON LATEST SATELLITE
LOOPS...WITH LOWERED AFTERNOON HIGH TEMPERATURES OVER CENTRAL
GA. UPDATED FORECASTS OUT SHORTLY.
PREV DISCUSSION... /ISSUED 752 AM EDT THU OCT 17 2013/
SHOWERS TODAY FOLLOWED BY COOLER AND DRIER CONDITIONS...
SHORT TERM /TODAY THROUGH FRIDAY/...
LATEST SURFACE ANALYSIS SHOWS HIGH PRESSURE RIDGE HAS SHIFTED
SOUTHWARD IN THE LAST 24 HOURS TO NOW RESIDE ALONG THE COAST OF
SOUTH CAROLINA AND GEORGIA. THIS IS QUICKLY BEING REPLACED BY A
TROUGH OF LOW PRESSURE MOVING INTO WEST GEORGIA FROM THE TENNESSEE
VALLEY AND LOWER MISSISSIPPI VALLEY. SURFACE CONVERGENCE WITHIN THIS
TROUGH HAS BEEN LIMITED THUS FAR AS HAS BEEN THE UPPER LEVEL
SUPPORT WITH LARGELY NON DIVERGENT FLOW NOTED AT UPPER LEVELS ON
LATEST RUC ANALYSIS. THIS HAS RESULTED IN ONLY SPOTTY LIGHT
RETURNS ON REGIONAL RADAR AND VERY LIGHT QPF FOR THE NORTHERN TIER.
FOR THE REMAINDER OF TODAY...WILL NEED TO WAIT FOR MORE
SIGNIFICANT SHORTWAVE ENERGY TO ARRIVE FOR MORE SUBSTANTIAL
COVERAGE AND INTENSITY OF SHOWERS. EVEN THOUGH...MODELS IN
AGREEMENT THAT SHORTWAVE WILL BE WEAKENING QUICKLY AND PROVIDE AT
BEST A GLANCING BLOW TO THE NORTHERN HALF OF THE FORECAST AREA.
RESULT WILL BE A SHARP POP GRADIENT FOR TODAY WITH CATEGORICAL
ADVERTISED FROM ROME THROUGH THE NORTHERN ATLANTA METRO WITH
RAPIDLY DECREASING POPS TO THE SOUTH AS FRONT APPROACHES THIS
EVENING.
AS FAR AS THUNDER POTENTIAL WITH THE LINE...SPC THUNDER PROBS FROM
THE SREF INDICATE SLIGHT CHANCE DEVELOPING ALONG THE I85 CORRIDOR
THIS AFTERNOON AND TRANSITIONING SOUTH THROUGH THE EARLY EVENING.
UPDRAFT STRENGTH WITH STORMS LOOKS TO REMAIN LIMITED AND NOT ALLOW
STRONG WINDS TO MIX DOWN IN MOST CASES ALTHOUGH AN ISOLATED STORM
COULD STILL SHOW GUSTY WIND POTENTIAL.
FRONT LOOKS TO STALL OVER SOUTH GEORGIA FRIDAY WITH ADDITIONAL
UPPER ENERGY TO MOVE OUT OF THE GULF OF MEXICO AND ALLOW FOR
ISENTROPIC INDUCED LIGHT RAIN TO DEVELOP AGAIN. HAVE GONE ABOVE
GUIDANCE AS ADIABATIC OMEGA FIELDS SUPPORT STRONG UPPER SUPPORT
AND AT LEAST LOW CHANCE POPS.
DEESE
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
MODELS CONSISTENT INDICATING THE COLD FRONT WITH BE SE OF THE
FORECAST AREA TO START FRIDAY NIGHT. HOWEVER GFS/NAM/EUROPEAN
SOMEWHAT DIFFERENT WITH THE PLACEMENT OF THE DEEPER MOISTURE AXIS
THROUGH THE NIGHT. GFS/NAM SIMILAR WITH SPREADING DEEPER MOISTURE
BACK OVER MAINLY CENTRAL GA AND THE EUROPEAN IS MORE BROADLY
SPREADING MOISTURE ACROSS THE ENTIRE AREA BY NIGHTS END. ALL IN ALL
THIS SEEMS TO KEEP BEST SHOWER CHANCES ACROSS MAINLY CENTRAL GA.
GFS/NAM KEEPS THE BEST MOISTURE AND SHOWER CHANCES ACROSS CENTRAL GA
FOR SATURDAY WHILE THE EUROPEAN SPREADS MOISTURE AND SHOWER CHANCES
ACROSS THE ENTIRE AREA. EITHER WAY THE BEST CHANCES FOR SHOWERS WILL
BE ACROSS CENTRAL GA AND POSSIBLY PORTIONS OF N GA. THE MOISTURE
COMING N DUE MAINLY TO THE APPROACH OF A SHORT WAVE.
THE MOISTURE WILL HAVE EXITED ALL BUT THE FAR SE CWA TO START SUNDAY
BUT WILL EXIT THAT AREA QUICKLY. SURFACE HIGH PRESSURE MOVES INTO
THE ATLANTIC ON MONDAY WHICH BEGINS TO SPREAD MOISTURE INTO THE FAR
SE CWA WITH SMALL SHOWER CHANCES ASSOCIATED. A WEAK COLD FRONT MOVES
TO THE AREA ON TUESDAY WITH INCREASED SHOWER CHANCES ACROSS THE AREA
TUESDAY/TUESDAY NIGHT. SMALL SHOWER CHANCES WILL BE CONFINED TO THE
FAR SE CWA TO START THE DAY ON WEDNESDAY BEFORE ENDING.
TEMPERATURES WILL BE TRENDING TO A LITTLE BELOW NORMAL FOR MUCH OF
THE EXTENDED PERIOD.
BDL
&&
.AVIATION...
18Z UPDATE...
MVFR CONDITIONS...WITH PATCHY IFR WITH HEAVIER SHRA...WILL
PERSIST UNTIL FRONT PUSHES THROUGH TAF SITES. SHRA WILL CONTINUE
IN ATL AREA SITES UNTIL 20Z BEFORE TAPERING OFF AND BY 00Z IN AHN.
MVFR CIGS BEHIND FRONT WILL SLOWLY SCT OUT OVERNIGHT WITH MODELS
HINTING AT POSSIBLE COOL AIR STRATUS...BUT BELIEVE CLOUDS WILL
REMAIN SCT THROUGH THE PERIOD. WINDS WILL SHIFT MORE W-NW BEHIND
THE FRONT WITH SPEEDS OF 5-10KTS.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM TO HIGH CONFIDENCE ALL ELEMENTS.
ATWELL
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 74 54 74 54 / 50 40 5 20
ATLANTA 72 55 73 58 / 70 30 5 10
BLAIRSVILLE 67 43 69 47 / 80 30 5 5
CARTERSVILLE 70 49 71 51 / 90 20 5 10
COLUMBUS 77 61 78 60 / 30 30 10 40
GAINESVILLE 70 52 72 55 / 80 40 5 10
MACON 80 57 76 60 / 30 40 10 50
ROME 70 48 71 49 / 70 10 5 5
PEACHTREE CITY 74 52 74 53 / 60 30 5 10
VIDALIA 84 64 80 64 / 5 10 30 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ATWELL
LONG TERM....01
AVIATION...ATWELL
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1201 PM EDT THU OCT 17 2013
.UPDATE...
ONLY MINOR TWEAKS MADE TO POPS/WEATHER BASED UPON CURRENT RADAR
TRENDS AS WELL AS TEMPERATURES BASED UPON LATEST SATELLITE
LOOPS...WITH LOWERED AFTERNOON HIGH TEMPERATURES OVER CENTRAL
GA. UPDATED FORECASTS OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 752 AM EDT THU OCT 17 2013/
.SHOWERS TODAY FOLLOWED BY COOLER AND DRIER CONDITIONS...
SHORT TERM /TODAY THROUGH FRIDAY/...
LATEST SURFACE ANALYSIS SHOWS HIGH PRESSURE RIDGE HAS SHIFTED
SOUTHWARD IN THE LAST 24 HOURS TO NOW RESIDE ALONG THE COAST OF
SOUTH CAROLINA AND GEORGIA. THIS IS QUICKLY BEING REPLACED BY A
TROUGH OF LOW PRESSURE MOVING INTO WEST GEORGIA FROM THE TENNESSEE
VALLEY AND LOWER MISSISSIPPI VALLEY. SURFACE CONVERGENCE WITHIN THIS
TROUGH HAS BEEN LIMITED THUS FAR AS HAS BEEN THE UPPER LEVEL
SUPPORT WITH LARGELY NON DIVERGENT FLOW NOTED AT UPPER LEVELS ON
LATEST RUC ANALYSIS. THIS HAS RESULTED IN ONLY SPOTTY LIGHT
RETURNS ON REGIONAL RADAR AND VERY LIGHT QPF FOR THE NORTHERN TIER.
FOR THE REMAINDER OF TODAY...WILL NEED TO WAIT FOR MORE
SIGNIFICANT SHORTWAVE ENERGY TO ARRIVE FOR MORE SUBSTANTIAL
COVERAGE AND INTENSITY OF SHOWERS. EVEN THOUGH...MODELS IN
AGREEMENT THAT SHORTWAVE WILL BE WEAKENING QUICKLY AND PROVIDE AT
BEST A GLANCING BLOW TO THE NORTHERN HALF OF THE FORECAST AREA.
RESULT WILL BE A SHARP POP GRADIENT FOR TODAY WITH CATEGORICAL
ADVERTISED FROM ROME THROUGH THE NORTHERN ATLANTA METRO WITH
RAPIDLY DECREASING POPS TO THE SOUTH AS FRONT APPROACHES THIS
EVENING.
AS FAR AS THUNDER POTENTIAL WITH THE LINE...SPC THUNDER PROBS FROM
THE SREF INDICATE SLIGHT CHANCE DEVELOPING ALONG THE I85 CORRIDOR
THIS AFTERNOON AND TRANSITIONING SOUTH THROUGH THE EARLY EVENING.
UPDRAFT STRENGTH WITH STORMS LOOKS TO REMAIN LIMITED AND NOT ALLOW
STRONG WINDS TO MIX DOWN IN MOST CASES ALTHOUGH AN ISOLATED STORM
COULD STILL SHOW GUSTY WIND POTENTIAL.
FRONT LOOKS TO STALL OVER SOUTH GEORGIA FRIDAY WITH ADDITIONAL
UPPER ENERGY TO MOVE OUT OF THE GULF OF MEXICO AND ALLOW FOR
ISENTROPIC INDUCED LIGHT RAIN TO DEVELOP AGAIN. HAVE GONE ABOVE
GUIDANCE AS ADIABATIC OMEGA FIELDS SUPPORT STRONG UPPER SUPPORT
AND AT LEAST LOW CHANCE POPS.
DEESE
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
MODELS CONSISTENT INDICATING THE COLD FRONT WITH BE SE OF THE
FORECAST AREA TO START FRIDAY NIGHT. HOWEVER GFS/NAM/EUROPEAN
SOMEWHAT DIFFERENT WITH THE PLACEMENT OF THE DEEPER MOISTURE AXIS
THROUGH THE NIGHT. GFS/NAM SIMILAR WITH SPREADING DEEPER MOISTURE
BACK OVER MAINLY CENTRAL GA AND THE EUROPEAN IS MORE BROADLY
SPREADING MOISTURE ACROSS THE ENTIRE AREA BY NIGHTS END. ALL IN ALL
THIS SEEMS TO KEEP BEST SHOWER CHANCES ACROSS MAINLY CENTRAL GA.
GFS/NAM KEEPS THE BEST MOISTURE AND SHOWER CHANCES ACROSS CENTRAL GA
FOR SATURDAY WHILE THE EUROPEAN SPREADS MOISTURE AND SHOWER CHANCES
ACROSS THE ENTIRE AREA. EITHER WAY THE BEST CHANCES FOR SHOWERS WILL
BE ACROSS CENTRAL GA AND POSSIBLY PORTIONS OF N GA. THE MOISTURE
COMING N DUE MAINLY TO THE APPROACH OF A SHORT WAVE.
THE MOISTURE WILL HAVE EXITED ALL BUT THE FAR SE CWA TO START SUNDAY
BUT WILL EXIT THAT AREA QUICKLY. SURFACE HIGH PRESSURE MOVES INTO
THE ATLANTIC ON MONDAY WHICH BEGINS TO SPREAD MOISTURE INTO THE FAR
SE CWA WITH SMALL SHOWER CHANCES ASSOCIATED. A WEAK COLD FRONT MOVES
TO THE AREA ON TUESDAY WITH INCREASED SHOWER CHANCES ACROSS THE AREA
TUESDAY/TUESDAY NIGHT. SMALL SHOWER CHANCES WILL BE CONFINED TO THE
FAR SE CWA TO START THE DAY ON WEDNESDAY BEFORE ENDING.
TEMPERATURES WILL BE TRENDING TO A LITTLE BELOW NORMAL FOR MUCH OF
THE EXTENDED PERIOD.
BDL
AVIATION...
12Z UPDATE...
LATEST RADAR IMAGERY SHOWING VERY LIGHT RETURNS OVER NORTH CENTRAL
GEORGIA BUT HAVING A LITTLE TROUBLE PROGRESSING SOUTHWARD. CIGS HAVE BEEN
A DIFFERENT STORY...HAVING LITTLE TROUBLE MOVING INTO THE NORTHERN
MOST TERMINALS WITH JUST VFR CIGS THUS FAR. EXPECT TREND TO BE A
LOWERING OF THESE CIGS WITH MVFR BY 16Z. SECONDARY SHOT OF -RA IS
EXPECTED TO DEVELOP OVER ALABAMA AND THEN MOVE OVER THE NORTHERN
TAF SITES BY 18Z AND LASTING 3 TO 4 HOURS. SOME RESIDUAL LOW LEVEL
MOISTURE MAY ALLOW FOR ISOLATED REDUCTIONS TO VSBY IN AREAS THAT
RECEIVED RAIN BUT CONFIDENCE TOO LOW FOR INCLUSION AT THIS TIME.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON CIG TIMING AND -SHRA.
POTENTIAL. HIGH ON REMAINING ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 74 54 74 54 / 50 40 5 20
ATLANTA 72 55 73 58 / 70 30 5 10
BLAIRSVILLE 67 43 69 47 / 80 30 5 5
CARTERSVILLE 70 49 71 51 / 80 20 5 10
COLUMBUS 77 61 78 60 / 30 30 10 40
GAINESVILLE 70 52 72 55 / 80 40 5 10
MACON 80 57 76 60 / 30 40 10 50
ROME 70 48 71 49 / 80 10 5 5
PEACHTREE CITY 74 52 74 53 / 60 30 5 10
VIDALIA 84 64 80 64 / 5 10 30 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ATWELL
LONG TERM....BDL
AVIATION...ATWELL
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
752 AM EDT THU OCT 17 2013
.PREV DISCUSSION... /ISSUED 426 AM EDT THU OCT 17 2013/
..SHOWERS TODAY FOLLOWED BY COOLER AND DRIER CONDITIONS...
SHORT TERM /TODAY THROUGH FRIDAY/...
LATEST SURFACE ANALYSIS SHOWS HIGH PRESSURE RIDGE HAS SHIFTED
SOUTHWARD IN THE LAST 24 HOURS TO NOW RESIDE ALONG THE COAST OF
SOUTH CAROLINA AND GEORGIA. THIS IS QUICKLY BEING REPLACED BY A
TROUGH OF LOW PRESSURE MOVING INTO WEST GEORGIA FROM THE TENNESSEE
VALLEY AND LOWER MISSISSIPPI VALLEY. SURFACE CONVERGENCE WITHIN THIS
TROUGH HAS BEEN LIMITED THUS FAR AS HAS BEEN THE UPPER LEVEL
SUPPORT WITH LARGELY NON DIVERGENT FLOW NOTED AT UPPER LEVELS ON
LATEST RUC ANALYSIS. THIS HAS RESULTED IN ONLY SPOTTY LIGHT
RETURNS ON REGIONAL RADAR AND VERY LIGHT QPF FOR THE NORTHERN TIER.
FOR THE REMAINDER OF TODAY...WILL NEED TO WAIT FOR MORE
SIGNIFICANT SHORTWAVE ENERGY TO ARRIVE FOR MORE SUBSTANTIAL
COVERAGE AND INTENSITY OF SHOWERS. EVEN THOUGH...MODELS IN
AGREEMENT THAT SHORTWAVE WILL BE WEAKENING QUICKLY AND PROVIDE AT
BEST A GLANCING BLOW TO THE NORTHERN HALF OF THE FORECAST AREA.
RESULT WILL BE A SHARP POP GRADIENT FOR TODAY WITH CATEGORICAL
ADVERTISED FROM ROME THROUGH THE NORTHERN ATLANTA METRO WITH
RAPIDLY DECREASING POPS TO THE SOUTH AS FRONT APPROACHES THIS
EVENING.
AS FAR AS THUNDER POTENTIAL WITH THE LINE...SPC THUNDER PROBS FROM
THE SREF INDICATE SLIGHT CHANCE DEVELOPING ALONG THE I85 CORRIDOR
THIS AFTERNOON AND TRANSITIONING SOUTH THROUGH THE EARLY EVENING.
UPDRAFT STRENGTH WITH STORMS LOOKS TO REMAIN LIMITED AND NOT ALLOW
STRONG WINDS TO MIX DOWN IN MOST CASES ALTHOUGH AN ISOLATED STORM
COULD STILL SHOW GUSTY WIND POTENTIAL.
FRONT LOOKS TO STALL OVER SOUTH GEORGIA FRIDAY WITH ADDITIONAL
UPPER ENERGY TO MOVE OUT OF THE GULF OF MEXICO AND ALLOW FOR
ISENTROPIC INDUCED LIGHT RAIN TO DEVELOP AGAIN. HAVE GONE ABOVE
GUIDANCE AS ADIABATIC OMEGA FIELDS SUPPORT STRONG UPPER SUPPORT
AND AT LEAST LOW CHANCE POPS.
DEESE
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
MODELS CONSISTENT INDICATING THE COLD FRONT WITH BE SE OF THE
FORECAST AREA TO START FRIDAY NIGHT. HOWEVER GFS/NAM/EUROPEAN
SOMEWHAT DIFFERENT WITH THE PLACEMENT OF THE DEEPER MOISTURE AXIS
THROUGH THE NIGHT. GFS/NAM SIMILAR WITH SPREADING DEEPER MOISTURE
BACK OVER MAINLY CENTRAL GA AND THE EUROPEAN IS MORE BROADLY
SPREADING MOISTURE ACROSS THE ENTIRE AREA BY NIGHTS END. ALL IN ALL
THIS SEEMS TO KEEP BEST SHOWER CHANCES ACROSS MAINLY CENTRAL GA.
GFS/NAM KEEPS THE BEST MOISTURE AND SHOWER CHANCES ACROSS CENTRAL GA
FOR SATURDAY WHILE THE EUROPEAN SPREADS MOISTURE AND SHOWER CHANCES
ACROSS THE ENTIRE AREA. EITHER WAY THE BEST CHANCES FOR SHOWERS WILL
BE ACROSS CENTRAL GA AND POSSIBLY PORTIONS OF N GA. THE MOISTURE
COMING N DUE MAINLY TO THE APPROACH OF A SHORT WAVE.
THE MOISTURE WILL HAVE EXITED ALL BUT THE FAR SE CWA TO START SUNDAY
BUT WILL EXIT THAT AREA QUICKLY. SURFACE HIGH PRESSURE MOVES INTO
THE ATLANTIC ON MONDAY WHICH BEGINS TO SPREAD MOISTURE INTO THE FAR
SE CWA WITH SMALL SHOWER CHANCES ASSOCIATED. A WEAK COLD FRONT MOVES
TO THE AREA ON TUESDAY WITH INCREASED SHOWER CHANCES ACROSS THE AREA
TUESDAY/TUESDAY NIGHT. SMALL SHOWER CHANCES WILL BE CONFINED TO THE
FAR SE CWA TO START THE DAY ON WEDNESDAY BEFORE ENDING.
TEMPERATURES WILL BE TRENDING TO A LITTLE BELOW NORMAL FOR MUCH OF
THE EXTENDED PERIOD.
BDL
&&
.AVIATION...
12Z UPDATE...
LATEST RADAR IMAGERY SHOWING VERY LIGHT RETURNS OVER NORTH CENTRAL
GEORGIA BUT HAVING A LITTLE TROUBLE PROGRESSING SOUTHWARD. CIGS HAVE BEEN
A DIFFERENT STORY...HAVING LITTLE TROUBLE MOVING INTO THE NORTHERN
MOST TERMINALS WITH JUST VFR CIGS THUS FAR. EXPECT TREND TO BE A
LOWERING OF THESE CIGS WITH MVFR BY 16Z. SECONDARY SHOT OF -RA IS
EXPECTED TO DEVELOP OVER ALABAMA AND THEN MOVE OVER THE NORTHERN
TAF SITES BY 18Z AND LASTING 3 TO 4 HOURS. SOME RESIDUAL LOW LEVEL
MOISTURE MAY ALLOW FOR ISOLATED REDUCTIONS TO VSBY IN AREAS THAT
RECEIVED RAIN BUT CONFIDENCE TOO LOW FOR INCLUSION AT THIS TIME.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON CIG TIMING AND -SHRA.
POTENTIAL. HIGH ON REMAINING ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 74 54 74 54 / 50 40 5 20
ATLANTA 72 55 73 58 / 70 30 5 10
BLAIRSVILLE 67 43 69 47 / 80 30 5 5
CARTERSVILLE 70 49 71 51 / 80 20 5 10
COLUMBUS 79 61 78 60 / 30 30 20 40
GAINESVILLE 70 52 72 55 / 80 40 5 10
MACON 82 57 76 60 / 40 40 20 50
ROME 70 48 71 49 / 80 10 5 5
PEACHTREE CITY 74 52 74 53 / 60 30 5 10
VIDALIA 85 64 80 64 / 5 10 30 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DEESE
LONG TERM....BDL
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
426 AM EDT THU OCT 17 2013
...SHOWERS TODAY FOLLOWED BY COOLER AND DRIER CONDITIONS...
.SHORT TERM /TODAY THROUGH FRIDAY/...
LATEST SURFACE ANALYSIS SHOWS HIGH PRESSURE RIDGE HAS SHIFTED
SOUTHWARD IN THE LAST 24 HOURS TO NOW RESIDE ALONG THE COAST OF
SOUTH CAROLINA AND GEORGIA. THIS IS QUICKLY BEING REPLACED BY A
TROUGH OF LOW PRESSURE MOVING INTO WEST GEORGIA FROM THE TENNESSEE
VALLEY AND LOWER MISSISSIPPI VALLEY. SURFACE CONVERGENCE WITHIN THIS
TROUGH HAS BEEN LIMITED THUS FAR AS HAS BEEN THE UPPER LEVEL
SUPPORT WITH LARGELY NON DIVERGENT FLOW NOTED AT UPPER LEVELS ON
LATEST RUC ANALYSIS. THIS HAS RESULTED IN ONLY SPOTTY LIGHT
RETURNS ON REGIONAL RADAR AND VERY LIGHT QPF FOR THE NORTHERN TIER.
FOR THE REMAINDER OF TODAY...WILL NEED TO WAIT FOR MORE
SIGNIFICANT SHORTWAVE ENERGY TO ARRIVE FOR MORE SUBSTANTIAL
COVERAGE AND INTENSITY OF SHOWERS. EVEN THOUGH...MODELS IN
AGREEMENT THAT SHORTWAVE WILL BE WEAKENING QUICKLY AND PROVIDE AT
BEST A GLANCING BLOW TO THE NORTHERN HALF OF THE FORECAST AREA.
RESULT WILL BE A SHARP POP GRADIENT FOR TODAY WITH CATEGORICAL
ADVERTISED FROM ROME THROUGH THE NORTHERN ATLANTA METRO WITH
RAPIDLY DECREASING POPS TO THE SOUTH AS FRONT APPROACHES THIS
EVENING.
AS FAR AS THUNDER POTENTIAL WITH THE LINE...SPC THUNDER PROBS FROM
THE SREF INDICATE SLIGHT CHANCE DEVELOPING ALONG THE I85 CORRIDOR
THIS AFTERNOON AND TRANSITIONING SOUTH THROUGH THE EARLY EVENING.
UPDRAFT STRENGTH WITH STORMS LOOKS TO REMAIN LIMITED AND NOT ALLOW
STRONG WINDS TO MIX DOWN IN MOST CASES ALTHOUGH AN ISOLATED STORM
COULD STILL SHOW GUSTY WIND POTENTIAL.
FRONT LOOKS TO STALL OVER SOUTH GEORGIA FRIDAY WITH ADDITIONAL
UPPER ENERGY TO MOVE OUT OF THE GULF OF MEXICO AND ALLOW FOR
ISENTROPIC INDUCED LIGHT RAIN TO DEVELOP AGAIN. HAVE GONE ABOVE
GUIDANCE AS ADIABATIC OMEGA FIELDS SUPPORT STRONG UPPER SUPPORT
AND AT LEAST LOW CHANCE POPS.
DEESE
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
MODELS CONSISTENT INDICATING THE COLD FRONT WITH BE SE OF THE
FORECAST AREA TO START FRIDAY NIGHT. HOWEVER GFS/NAM/EUROPEAN
SOMEWHAT DIFFERENT WITH THE PLACEMENT OF THE DEEPER MOISTURE AXIS
THROUGH THE NIGHT. GFS/NAM SIMILAR WITH SPREADING DEEPER MOISTURE
BACK OVER MAINLY CENTRAL GA AND THE EUROPEAN IS MORE BROADLY
SPREADING MOISTURE ACROSS THE ENTIRE AREA BY NIGHTS END. ALL IN ALL
THIS SEEMS TO KEEP BEST SHOWER CHANCES ACROSS MAINLY CENTRAL GA.
GFS/NAM KEEPS THE BEST MOISTURE AND SHOWER CHANCES ACROSS CENTRAL GA
FOR SATURDAY WHILE THE EUROPEAN SPREADS MOISTURE AND SHOWER CHANCES
ACROSS THE ENTIRE AREA. EITHER WAY THE BEST CHANCES FOR SHOWERS WILL
BE ACROSS CENTRAL GA AND POSSIBLY PORTIONS OF N GA. THE MOISTURE
COMING N DUE MAINLY TO THE APPROACH OF A SHORT WAVE.
THE MOISTURE WILL HAVE EXITED ALL BUT THE FAR SE CWA TO START SUNDAY
BUT WILL EXIT THAT AREA QUICKLY. SURFACE HIGH PRESSURE MOVES INTO
THE ATLANTIC ON MONDAY WHICH BEGINS TO SPREAD MOISTURE INTO THE FAR
SE CWA WITH SMALL SHOWER CHANCES ASSOCIATED. A WEAK COLD FRONT MOVES
TO THE AREA ON TUESDAY WITH INCREASED SHOWER CHANCES ACROSS THE AREA
TUESDAY/TUESDAY NIGHT. SMALL SHOWER CHANCES WILL BE CONFINED TO THE
FAR SE CWA TO START THE DAY ON WEDNESDAY BEFORE ENDING.
TEMPERATURES WILL BE TRENDING TO A LITTLE BELOW NORMAL FOR MUCH OF
THE EXTENDED PERIOD.
BDL
&&
.AVIATION...
06Z UPDATE...
LATEST RADAR IMAGERY SHOWING VERY LIGHT RETURNS OVER EXTREME NORTH
GEORGIA WITH VERY LITTLE MOVEMENT NOTED SOUTHWARD. CIGS HAVE BEEN
A DIFFERENT STORY...HAVING LITTLE TROUBLE MOVING INTO THE
NORTHERN MOST TERMINALS WITH JUST VFR CIGS THUS FAR. EXPECT TREND
TO BE A LOWERING OF THESE CIGS INTO DAYBREAK WITH MVFR BY 14Z AT
ATL AND SURROUNDING TERMINALS. SECONDARY SHOT OF -RA IS EXPECTED
TO DEVELOP OVER ALABAMA AND THEN MOVE OVER THE NORTHERN TAF SITES
BY 18Z AND LASTING 3 TO 4 HOURS. SOME RESIDUAL LOW LEVEL MOISTURE
MAY ALLOW FOR ISOLATED REDUCTIONS TO VSBY IN AREAS THAT RECEIVED
RAIN BUT CONFIDENCE TOO LOW FOR INCLUSION AT THIS TIME.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON CIG TIMING AND -SHRA.
POTENTIAL. HIGH ON REMAINING ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 74 54 74 54 / 50 40 5 20
ATLANTA 72 55 73 58 / 70 30 5 10
BLAIRSVILLE 67 43 69 47 / 80 30 5 5
CARTERSVILLE 70 49 71 51 / 80 20 5 10
COLUMBUS 79 61 78 60 / 30 30 20 40
GAINESVILLE 70 52 72 55 / 80 40 5 10
MACON 82 57 76 60 / 40 40 20 50
ROME 70 48 71 49 / 80 10 5 5
PEACHTREE CITY 74 52 74 53 / 60 30 5 10
VIDALIA 85 64 80 64 / 5 10 30 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DEESE
LONG TERM....BDL
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1237 AM EDT THU OCT 17 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 124 PM EDT WED OCT 16 2013
UPPER ATMOSPHERE WINDS OVER INDIANA WILL REMAIN NORTHWEST INTO NEXT
WEEK. THAT MEANS AT THE SURFACE WE CAN EXPECT SEVERAL COLD FRONTS
TO PASS. BETWEEN COLD FRONTS...THERE SHOULD BE BRIEF PERIODS WHEN
INDIANA IS UNDER HIGH PRESSURE.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 950 PM EDT WED OCT 16 2013
STRATO CU DECK HAS PUSHED AS FAR EAST AS A KOKOMO TO COVINGTON LINE.
BUT HAS MOVED LITTLE LAST FEW HOURS. EXPECT NO MORE THAN A FEW
TENTH OF CLOUD COVER OVER THE REST OF THE REGION NEXT FEW HOURS.
AFTER THAT MODEL SOUNDINGS INDICATE MID CLOUDS WILL SPREAD INTO ALL
AREAS LATE TONIGHT. ONLY OTHER CHANGE WILL BE TO ADD SLIGHT CHANCE
OF SHOWERS OVER WESTERN SECTIONS PER SREF AND RAP MODELS WHICH
INDICATES POSSIBLE PRECIP THOSE AREAS TOWARDS 12Z.
CONCERNING TEMPERATURES...WENT A LITTLE LOWER ACROSS NORTHEAST AREAS
AS TEMPERATURES THERE ARE APPROACHING CURRENT FORECASTED LOWS.
CURRENT FORECAST SEEMS ON TRACK FOR TEST OF THE REGION.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 124 PM EDT WED OCT 16 2013
MOST PRESSING PROBLEM RAIN CHANCES TOMORROW.
GREAT DIFFERENCE BETWEEN MAV AND MET POPS TOMORROW...WITH MAV
WETTER. I PREFER MAV. IF YOU LOOK AT PRESSURE ADVENTURE ON POTENTIAL
VORTICITY SURFACES...BOTH NAM AND GFS HAVE GOOD FORCING THURSDAY. IN
THESE NORTHWEST FLOW SITUATIONS SUCH FORCING USUALLY AT LEAST CHANCE
FOR RAIN.
MODELS CONCUR ABOUT DRY LATE THURSDAY THROUGH FRIDAY. WITH
BASICALLY CYCLONIC FLOW AND WARM GREAT LAKES WE SHOULD STAY MOSTLY
CLOUDY.
FRIDAY NIGHT...POPS AGAIN DIVERGE. MET LIKELY AND MAV LOW END
CHANCE. MEX SAYS CHANCE WILL LAST INTO SATURDAY. THIS IS A TOUGH
CALL BUT WILL USE MAV BECAUSE GFS USUALLY HANDLES SYNOPTIC SCALE
FORCING THAT FAR OUT.
FOR TEMPS THURSDAY GOING WITH COOLER MAV GIVEN I LIKE ITS RELATIVELY
HIGH RAIN CHANCES. AFTER THURSDAY MOS TEMPS CLOSE. WILL USE
CONSENSUS TO GET WHATEVER SKILL THAT TECHNIQUE HAS. CONFIDENCE IN
TEMPERATURE FORECAST NOT HIGH WITH THIS PACKAGE. RELATIVELY SMALL
CHANGES IN SKY COVER COULD HAVE A BIG EFFECT
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 207 PM EDT WED OCT 16 2013
EXTENDED FORECAST CAN BE CHARACTERIZED BY LARGE SCALE CYCLONIC
FLOW OVER THE GREAT LAKES WITH ONE OR MORE UPPER LEVEL WAVES MOVING
THROUGH THE LARGER SCALE FLOW AND POTENTIALLY CAUSING A FEW PERIODIC
CHANCES FOR SHOWERS. ALLBLEND GUIDANCE APPEARS REASONABLE SO DID NOT
STRAY FAR. HIGHS WILL STRUGGLE TO MUCH OUT OF THE 50S MOST
DAYS...WITH LOWS GENERALLY IN THE LOW 40S...AND PERHAPS COOLER ON
ANY CLEARER NIGHTS. FROST DOES NOT LOOK POSSIBLE AT THIS TIME.
&&
.AVIATION /DISCUSSION FOR THE 17/06Z TAFS/...
ISSUED AT 1237 AM EDT THU OCT 17 2013
LOW CHANCE FOR MVFR CONDITIONS APPROXIMATELY 12Z-18Z...OTHERWISE VFR
EXPECTED ACROSS THE AREA.
MID CLOUD WILL INCREASE AND GRADUALLY LOWER OVERNIGHT AT THE SITES
AS UPPER WAVE MOVES TOWARD AREA. MODELS ARE MORE BULLISH WITH RAIN
AFTER 12Z ACROSS THE AREA...BUT RAIN WILL HAVE TO OVERCOME INITIALLY
DRY ATMOSPHERE.
WILL INCLUDE VCSH TO ACCOUNT FOR THIS POSSIBILITY. AS RAIN DEVELOPS
OVERNIGHT...TAFS CAN BE UPDATED IF NEEDED ONCE TRENDS BECOME
APPARENT. LOW CHANCE FOR MVFR CONDITIONS WITH ANY RAIN THAT MOVES IN.
CONDITIONS WILL IMPROVE THURSDAY AFTERNOON AS SYSTEM EXITS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JK
NEAR TERM...JH
SHORT TERM...JK
LONG TERM....JK/SMF
AVIATION...50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS DES MOINES IA
632 PM CDT FRI OCT 18 2013
.SHORT TERM /TONIGHT/...
ISSUED AT 323 PM CDT FRI OCT 18 2013
IN A NEAR REPEAT OF YESTERDAY AFTERNOONS FORECAST...ANOTHER 500 MB
SHORTWAVE EMBEDDED IN THE MEAN CENTRAL NORTH AMERICAN LONGWAVE
TROUGH IS POISED TO TRACK THROUGH IOWA LATE TONIGHT AND INTO
TOMORROW MORNING. AS WITH ITS PREDECESSOR...FORCING AND MOISTURE
WILL BE SPARSE AND ANY RAIN SHOWERS OVERNIGHT WILL BE CONFINED TO
NORTHERN IOWA. THIS SCENARIO WAS HANDLED WELL BY THE HIGH RES WRF
ARW AND RAP...THUS USED A BLEND OF THESE TWO MODELS FOR THE
PRECIPITATION FORECAST. A SECOND IMPULSE/VORT MAX SLIDES DOWN THE
REAR FLANK OF THE LONGWAVE TROUGH IN WESTERN MINNESOTA AND NORTHWEST
IOWA TOWARDS THE END OF THE PERIOD. MOISTURE PROFILES ARE SLIGHTLY
MORE CONDUCIVE FOR RAINFALL AND HAVE INCREASED POPS ACCORDINGLY IN
THE NORTHWEST TOWARDS 12Z SAT.
290 TO 300K ISENTROPIC ACCENT GENERATED A BAND RAIN AND SNOW ACROSS
KANSAS AND NORTHERN MISSOURI TODAY. THE ASSOCIATED SHIELD OF
CIRROSTRATUS AND ALTOSTRATUS CLOUDS PROPAGATED INTO IOWA THIS
MORNING AND PUT A DAMPER ON HIGHS ACROSS THE SOUTHERN HALF OF THE
CWA. THIS SYSTEM WILL PULL ENE THIS EVENING AS THE UPPER LEVEL
TROUGH DIGS INTO THE CENTRAL PLAINS. THERE IS SOME UNCERTAINTY WITH
HOW MUCH OF THE CLOUD COVER OVER SOUTHERN IOWA WILL CLEAR OUT
BETWEEN THE 06 AND 12Z TIME FRAME. BOTH THE NAM AND RAP SOUNDINGS
HINT AT SOME CLEARING TOWARDS MORNING...SO LOWERED MIN TEMPS IN THE
NISH VALLEY AND OTHER PORTIONS OF SOUTHWEST IOWA.
.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 323 PM CDT FRI OCT 18 2013
BROAD LONG WAVE TROF WILL REMAIN ENTRENCHED ACROSS THE EASTERN
HALF OF THE UNITED STATES DURING THIS FORECAST PERIOD.
THEREFORE...BELOW NORMAL TEMPERATURES ARE EXPECTED FOR MUCH OF THE
NEXT WEEK. THERE WILL ALSO BE THREATS FOR LIGHT PRECIPITATION FROM
TIME TO TIME AS SYSTEMS PASS THROUGH THE STRONG NORTHWEST FLOW.
FIRST WEAK SYSTEM GLANCES THE NORTH TOMORROW MORNING ALTHOUGH THE
BULK OF THE FORCING WILL REMAIN NORTH OF IOWA. HAVE CONTINUED THE
THREAT FOR SOME ISOLATED/SCATTERED SHOWERS IN THE MORNING BUT WITH
SUBSIDENCE ARRIVING BY AFTERNOON...SHOULD SEE ANY ACTIVITY QUICKLY
ENDING. WARM ADVECTION INTO SUNDAY WILL MAKE IT THE WARMEST DAY
OVER THE NEXT WEEK. THE WARMER AIR IS AHEAD OF THE NEXT SYSTEM
DIVING SOUTHEAST INTO THE REGION. ONCE AGAIN...THE FORCING
ASSOCIATED WITH THIS SYSTEM REMAINS NORTH OF IOWA WITH ANY PCPN
THREAT RESIDING NEAR THE MINNESOTA BORDER. STRONG COLD ADVECTION
WILL ARRIVE BY LATE IN THE DAY WITH A MUCH COLDER AIRMASS BECOMING
ESTABLISHED ACROSS THE STATE ON MONDAY. ONE FINAL SYSTEM DROPS
SOUTHEAST TOWARD THE STATE LATE MONDAY NIGHT INTO TUESDAY. THE
EURO IS MOST AGGRESSIVE WITH SATURATION AND LIFT ACROSS IOWA WITH
A FEW TENTHS OF PCPN ON TUESDAY. GIVEN RELATIVELY COLD THERMAL
PROFILES DURING THIS EVENT...WOULDNT BE SURPRISED TO SEE SOME SNOW
MIXED WITH RAIN WITH STRONG DYNAMICAL COOLING SUGGESTED BY THE
LIFT. THE COLDER AIRMASS WILL THEN REMAIN ESSENTIALLY IN PLACE
THROUGH THE END OF NEXT WEEK. THIS SHOULD EFFECTIVELY END THE
GROWING SEASON ACROSS CENTRAL IOWA FOR THOSE LOCATIONS THAT HAVENT
ALREADY SEEN A FREEZE.
&&
.AVIATION...19/00Z
ISSUED AT 632 PM CDT FRI OCT 18 2013
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH 12Z WITH LIGHT
SOUTHWEST WINDS. A FEW SHOWERS AND MVFR CIGS POSSIBLE OVER THE
NORTH AND NORTHEAST SATURDAY MORNING AS A BOUNDARY MOVES THROUGH
REGION. THE LIGHT SOUTHWEST WINDS WILL BECOME BREEZY SATURDAY
MORNING THEN BECOME MORE WESTERLY BY THE AFTERNOON.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SKOW
LONG TERM...COGIL
AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
656 AM CDT Thu Oct 17 2013
...Updated Aviation section for 12Z TAFs...
.SHORT TERM...(Today and tonight)
ISSUED AT 358 AM CDT THU OCT 17 2013
A potential vorticity maximum entering British Columbia early this
morning will move rapidly south-southeastward and approach the
western high plains late tonight. This system will bring mid level
moisture with it. Ahead of this system, a lead shortwave trough
progressing through eastern Montana this morning, was helping to
push a cold front into South Dakota as of 3 am. Behind the front
rain and snow were falling from northwestern South Dakota into
southwest North Dakota and southeastern Montana where temperatures
were between 33 and 36F. Mid level frontogenesis and warm
advection will develop toward Friday morning ahead of the
aforementioned potential vorticity maximum, with the tropospheric
column quickly saturating. Lapse rates will become moist-neutral
above the mid level frontal inversion around 700mb, which favors a
greater amount of lift for a given amount of forcing. Precipitation
in the form of rain will develop between 09 and 12z. Temperatures
may fall initially and then hold steady or slowly rise as cloud
cover increases. Then as evaporational cooling occurs due to
falling precipitation, temperatures will fall once again between
12 and 14Z Friday. The rain may change to snow for some places
after 12z Friday as the freezing level falls below 2000 ft AGL;
but this is covered in the long term section below. The low
temperature grid for Friday extends until 14z and then is when
lows may occur from Garden City north and west to Scott City and
Dighton.
In the nearer term, temperatures should have no trouble reaching
into the 60s today given strong insolation ahead of the cold front.
.LONG TERM...(Friday through Wednesday)
ISSUED AT 428 AM CDT THU OCT 17 2013
Much of the time and effort in the Long Term forecast went into the
Friday forecast...as there is a myriad of challenges...including
precipitation type! A northwest flow jet streak (which can be seen
on water vapor imagery and RAP analysis moving south out of Alberta)
will be the impetus for for out next precipitation event. As the
disturbance approaches Colorado by early Friday morning,
frontogenesis around 700mb will be on the increase from eastern
Colorado into northwestern Kansas. A fairly intense temperature
gradient will exist at this level (-10C at around North Platte, NE
to +2C at Amarillo, TX, per GEM and ECMWF models), so convergence
and deformation in the flow field will certainly result in fairly
decent lift to promote cloud and precipitation...including banded
precipitation. Moderate precipitation (in mainly the form of rain)
will develop and expand southeast during the morning hours with the
peak of the event affecting much of the southwest Kansas region by
midday with the 700mb frontogenesis and saturated RH centered from
Hugoton to Dodge to LaCrosse at 18z Friday. The GEM and ECMWF are in
very good agreement in their respective 42-hour forecast, so will be
following this "blend" for the official forecast.
Confidence is high that measureable precipitation will occur, so we
continued the uptrend in POPs well into the "Likely" range at 70
percent. A further increase into the "Categorical" range (80+) will
likely be needed if the trends continue in the upcoming morning
model solutions. The ECMWF and Canadian GEM models both show a
rather cold solution as well. Given the strong agreement between
the two models, see no reason why not to trust the progs. They both
show midday surface temperatures at the height of the precipitation
event in the 37 to 40F range with 850mb temperatures 0C to perhaps
-1C. Ideally, I would like to see a larger area of -1 to -2C at
850mb for higher confidence in snow given the time of year. There
will need to be some substantial cooling via vigorous ascent...in
combination with evaporative cooling...in order to get snowflakes
reaching the ground. That being said, it would certainly appear that
this is possible in the strongest band of precipitation...where
temperatures could briefly dip down to the mid 30s and some wet
snowflakes mix in with the rain. Will go ahead and add in a small
area of Rain OR Snow in the grids where hourly temperature is less
than or equal to 38F. Most areas, however, should see just a cold
rain.
The timing of the end of the precipitation event will be critical as
far as temperature recovery and MaxT is concerned late Friday. Areas
farther northwest (say, northwest of a Syracuse to Hays line), will
be seeing the precipitation ending earlier, and thus a better chance
at warming back up through the mid 40s. Areas southeast of a Liberal
to Dodge to Stafford line, however, may not see afternoon
temperatures above the lower 40s. As far as precipitation amounts
are concerned, we are looking at a potential widespread two to three
tenths of an inch, on average, across the southwest Kansas region.
The storm system will rapidly clear the area by Friday night with
westerly downslope low level winds in its wake. Lows in the lower to
mid 30s are expected as skies clear. Dewpoints will likely fall into
the mid to upper 20s across the western half of the region with the
downslope. Wind speeds will probably stay up just enough to prevent
a widespread freeze, however this will need to be watched closely
considering the temperature will not need to fall much from the
Friday max.
Saturday and beyond:
The larger scale general circulation regime will not change much at
all this weekend going into next week...with troughing across the
Upper Midwest region toward Hudson Bay and higher heights along the
West Coast. This will keep the Western Plains in a northwest flow
regime with downslope influence across western Kansas. The cold
surges should remain northeast of the southwest Kansas region,
however another weak front Late Sunday/early Monday will provide a
slight cool-down (back into the lower-mid 60s after a fairly decent
Sunday with highs around 70). After this front, the latest ECMWF
shows a potential break-down of the Hudson Bay longwave trough with
the mid level flow becoming more westerly (and weaker). This may be
temporary, though, with the longwave trough potentially reloading
from south-central Canada into the north-central CONUS.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 652 AM CDT THU OCT 17 2013
Light winds this morning will increase to around 12 to 14 knots
out of the north-northwest as a weak cold front pushes south early
this afternoon. A storm system approaching tonight will result in
the development of rain late tonight...with rain beginning to
overspread GCK, DDC, and HYS terminals as early as 09 or 10Z
Friday. Rain and low ceilings in the IFR/LIFR category will
prevail much of the day Friday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 40 44 34 / 0 30 70 10
GCK 64 38 46 33 / 0 50 70 0
EHA 65 38 45 33 / 0 30 50 0
LBL 67 41 45 34 / 0 30 70 0
HYS 64 39 46 35 / 0 60 70 0
P28 69 42 45 36 / 0 10 60 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY until 9 AM CDT this morning FOR KSZ030-031-045-
046-064-065-078>080-088-089.
FREEZE WARNING until 9 AM CDT /8 AM MDT/ this morning FOR KSZ043-
044-061>063-074>077-084>087.
&&
$$
SHORT TERM...Finch
LONG TERM...Umscheid
AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
430 AM CDT Thu Oct 17 2013
...Updated Long Term Section...
.SHORT TERM...(Today and tonight)
ISSUED AT 358 AM CDT THU OCT 17 2013
A potential vorticity maximum entering British Columbia early this
morning will move rapidly south-southeastward and approach the
western high plains late tonight. This system will bring mid level
moisture with it. Ahead of this system, a lead shortwave trough
progressing through eastern Montana this morning, was helping to
push a cold front into South Dakota as of 3 am. Behind the front
rain and snow were falling from northwestern South Dakota into
southwest North Dakota and southeastern Montana where temperatures
were between 33 and 36F. Mid level frontogenesis and warm
advection will develop toward Friday morning ahead of the
aforementioned potential vorticity maximum, with the tropospheric
column quickly saturating. Lapse rates will become moist-neutral
above the mid level frontal inversion around 700mb, which favors a
greater amount of lift for a given amount of forcing. Precipitation
in the form of rain will develop between 09 and 12z. Temperatures
may fall initially and then hold steady or slowly rise as cloud
cover increases. Then as evaporational cooling occurs due to
falling precipitation, temperatures will fall once again between
12 and 14Z Friday. The rain may change to snow for some places
after 12z Friday as the freezing level falls below 2000 ft AGL;
but this is covered in the long term section below. The low
temperature grid for Friday extends until 14z and then is when
lows may occur from Garden City north and west to Scott City and
Dighton.
In the nearer term, temperatures should have no trouble reaching
into the 60s today given strong insolation ahead of the cold front.
.LONG TERM...(Friday through Wednesday)
ISSUED AT 428 AM CDT THU OCT 17 2013
Much of the time and effort in the Long Term forecast went into the
Friday forecast...as there is a myriad of challenges...including
precipitation type! A northwest flow jet streak (which can be seen
on water vapor imagery and RAP analysis moving south out of Alberta)
will be the impetus for for out next precipitation event. As the
disturbance approaches Colorado by early Friday morning,
frontogenesis around 700mb will be on the increase from eastern
Colorado into northwestern Kansas. A fairly intense temperature
gradient will exist at this level (-10C at around North Platte, NE
to +2C at Amarillo, TX, per GEM and ECMWF models), so convergence
and deformation in the flow field will certainly result in fairly
decent lift to promote cloud and precipitation...including banded
precipitation. Moderate precipitation (in mainly the form of rain)
will develop and expand southeast during the morning hours with the
peak of the event affecting much of the southwest Kansas region by
midday with the 700mb frontogenesis and saturated RH centered from
Hugoton to Dodge to LaCrosse at 18z Friday. The GEM and ECMWF are in
very good agreement in their respective 42-hour forecast, so will be
following this "blend" for the official forecast.
Confidence is high that measureable precipitation will occur, so we
continued the uptrend in POPs well into the "Likely" range at 70
percent. A further increase into the "Categorical" range (80+) will
likely be needed if the trends continue in the upcoming morning
model solutions. The ECMWF and Canadian GEM models both show a
rather cold solution as well. Given the strong agreement between
the two models, see no reason why not to trust the progs. They both
show midday surface temperatures at the height of the precipitation
event in the 37 to 40F range with 850mb temperatures 0C to perhaps
-1C. Ideally, I would like to see a larger area of -1 to -2C at
850mb for higher confidence in snow given the time of year. There
will need to be some substantial cooling via vigorous ascent...in
combination with evaporative cooling...in order to get snowflakes
reaching the ground. That being said, it would certainly appear that
this is possible in the strongest band of precipitation...where
temperatures could briefly dip down to the mid 30s and some wet
snowflakes mix in with the rain. Will go ahead and add in a small
area of Rain OR Snow in the grids where hourly temperature is less
than or equal to 38F. Most areas, however, should see just a cold
rain.
The timing of the end of the precipitation event will be critical as
far as temperature recovery and MaxT is concerned late Friday. Areas
farther northwest (say, northwest of a Syracuse to Hays line), will
be seeing the precipitation ending earlier, and thus a better chance
at warming back up through the mid 40s. Areas southeast of a Liberal
to Dodge to Stafford line, however, may not see afternoon
temperatures above the lower 40s. As far as precipitation amounts
are concerned, we are looking at a potential widespread two to three
tenths of an inch, on average, across the southwest Kansas region.
The storm system will rapidly clear the area by Friday night with
westerly downslope low level winds in its wake. Lows in the lower to
mid 30s are expected as skies clear. Dewpoints will likely fall into
the mid to upper 20s across the western half of the region with the
downslope. Wind speeds will probably stay up just enough to prevent
a widespread freeze, however this will need to be watched closely
considering the temperature will not need to fall much from the
Friday max.
Saturday and beyond:
The larger scale general circulation regime will not change much at
all this weekend going into next week...with troughing across the
Upper Midwest region toward Hudson Bay and higher heights along the
West Coast. This will keep the Western Plains in a northwest flow
regime with downslope influence across western Kansas. The cold
surges should remain northeast of the southwest Kansas region,
however another weak front Late Sunday/early Monday will provide a
slight cool-down (back into the lower-mid 60s after a fairly decent
Sunday with highs around 70). After this front, the latest ECMWF
shows a potential break-down of the Hudson Bay longwave trough with
the mid level flow becoming more westerly (and weaker). This may be
temporary, though, with the longwave trough potentially reloading
from south-central Canada into the north-central CONUS.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1257 AM CDT THU OCT 17 2013
A weak cold front will pass across western Kansas Thursday,
shifting winds to the northwest at 10-14 kts. Mid level cloud
AOA100 will spread into western Kansas toward the end of the TAF
period ahead of an upper level disturbance. VFR conditions will
prevail.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 40 44 34 / 0 30 70 10
GCK 64 38 46 33 / 0 50 70 0
EHA 65 38 45 33 / 0 30 50 0
LBL 67 41 45 34 / 0 30 70 0
HYS 64 39 46 35 / 0 60 70 0
P28 69 42 45 36 / 0 10 60 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY until 9 AM CDT this morning FOR KSZ030-031-045-
046-064-065-078>080-088-089.
FREEZE WARNING until 9 AM CDT /8 AM MDT/ this morning FOR KSZ043-
044-061>063-074>077-084>087.
&&
$$
SHORT TERM...Finch
LONG TERM...Umscheid
AVIATION...Finch
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
306 PM EDT THU OCT 17 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TODAY BEFORE PASSING
THROUGH TONIGHT. HIGH PRESSURE WILL BRIEFLY BUILD IN FRIDAY BEFORE A
COLD FRONT PASSES THROUGH LATE SATURDAY INTO SATURDAY NIGHT. HIGH
PRESSURE WILL RETURN EARLY NEXT WEEK...BUT ANOTHER COLD FRONT WILL
PASS THROUGH LATER TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
A COUPLE OF HRS OF ONLY PARTLY CLOUDY CONDITIONS AND PLENTY OF SUN
HELPED TEMPS E OF THE BLUE RIDGE TO REACH THE M-U70S. A FEW
LOCALES MAY BRIEFLY TOUCH 80 BEFORE THE NEXT WAVE OF CLOUDS AND
LIGHT PRECIP ARRIVE. DEPENDING ON WHICH PORTION OF THE CWA...THERE
WILL BE SPOTS THAT GET LARGELY MISSED W/ THE INCOMING PRECIP -
OTHER THAN A FEW SPRINKLES. THE PRE-FRONTAL SHOWER ACTIVITY IS
APPROACHING IN RANDOM WAVES AND BATCHES THAT CONTINUE TO DISSIPATE
ALONG THE FRINGES. THE MORE SOLID WAVES OF LIGHT TO MODERATE RAIN
WILL AFFECT THE POTOMAC HIGHLANDS/NRN SHEN VLY AND ALSO ACROSS
LOWER SRN MD. IN BETWEEN...ONLY PERIODS OF LIGHT AND ISOLATED
SHOWERS ARE EXPECTED. THE LATEST FEW RUNS OF THE HRRR SHOW THE IN
BETWEEN AREAS...INCLUDING MUCH OF THE METRO AREAS - TO STAY MAINLY
DRY ONCE THIS CURRENT BATCH OF RAIN MOVES THRU.
A "KICKER" SHORTWAVE - A COMPACT MID-LEVEL FEATURE THAT IS CAUGHT
IN THE FLOW AT THE BASE OF THE TROUGH WILL SWING ACROSS THE AREA
TONIGHT. THIS FEATURE WILL HELP TO DEVELOP A SFC LOW AND
ACCOMPANYING WARM/COLD FRONTS - OF WHICH THE COLD FRONT WILL SLIDE
THRU LATE TONIGHT. SCATTERED BATCHES OF MOD-HEAVY RAIN POSSIBLE
BUT VERY LOCALIZED AND ONLY A RUMBLE OF THUNDER OR TWO AT BEST -
AND LIMITED TO THE NRN-MOST MD COUNTIES FOR A BRIEF PERIOD.
A QUICK END TO THE PRECIP JUST INTO THE OVERNIGHT HRS AND
DRY/COOLER AIR PUSHES IN FROM BEHIND AND SPREADS E THRU THE
PREDAWN HRS. THIS WILL HELP TEMPS TO DROP 10-15 DEG BELOW THE PREV
NIGHT`S LOW TEMPS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
AS THE WEAK SURFACE LOW MOVES NE IT WILL SWEEP THE COLD FRONT
QUICKLY THRU THE REGION. SKIES WILL LIKELY CLEAR OUT WITHIN A FEW
HOURS AFTER MIDNIGHT AS THE COOLER AIR SWEEPS IN WITH SOME GUSTY
WINDS FOR A TIME. DRY AIR WILL CONTINUE TO FUNNEL INTO THE REGION
UNTIL MIDDAY...W/ A STIFF WLY BREEZE KEEPING TEMPS COOL - ONLY
REACHING THE M-U60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
AN UPPER-LEVEL TROUGH WILL REMAIN OVER THE GREAT LAKES AND CENTRAL
CONUS THROUGHOUT THE PERIOD. A SERIES OF UPPER-LEVEL DISTURBANCES
WILL PASS THROUGH OUR AREA IN THE SOUTHWEST FLOW ALOFT.
FOR FRIDAY...SURFACE HIGH PRESSURE WILL REMAIN OVER THE REGION
USHERING DRY AND SEASONABLE CONDITIONS. HOWEVER...AN UPPER-LEVEL
DISTURBANCE AND ITS ASSOCIATED COLD FRONT ARE EXPECTED TO PASS
THROUGH THE AREA LATER SATURDAY INTO SATURDAY NIGHT. A FEW SHOWERS
ARE POSSIBLE...BUT ANY PRECIPITATION WILL BE LIGHT SINCE THE FRONT
WILL BE WEAK AND IT WILL CONTAIN LITTLE MOISTURE.
HIGH PRESSURE WILL RETURN FOR SUNDAY AND MONDAY...BRINGING MORE DRY
AND SEASONABLE CONDITIONS. THE NEXT DISTURBANCE AND ITS ASSOCIATED
COLD FRONT WILL PASS THROUGH TUESDAY AND WEDNESDAY. THE 00Z GFS
INDICATES STRONGER LOW PRESSURE ASSOCIATED WITH THIS SYSTEM...BUT
KEPT THE FORECAST DRY FOR NOW SINCE IT IS A POSITIVELY TILTED TROUGH
WITH MOST OF THE ENERGY IN THE NORTHERN STREAM. WILL CONTINUE TO
MONITOR THE LATEST GUIDANCE BECAUSE IF THE SURFACE LOW DOES
INTENSIFY QUICK ENOUGH...THEN RAIN CHANCES WILL INCREASE
SIGNIFICANTLY.
CANADIAN HIGH PRESSURE MAY BUILD TOWARD THE REGION BEHIND THIS
DISTURBANCE FOR THE END OF THE WEEK...BRINGING THE COLDEST AIR OF
THE SEASON SO FAR.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
MVFR CIGS AND SHOWERS ARE POSSIBLE THIS EVE BUT QUICKLY EXITING
AROUND MIDNIGHT AS A COLD FRONT SWINGS THRU AND SWITCHES WINDS TO
A GUSTY NWLY FLOW BY DAWN ON FRIDAY.
HIGH PRESSURE WILL BRING VFR CONDITIONS FRIDAY. NORTHWEST WINDS WILL
GUST AROUND 15 TO 20 KNOTS DURING THE DAY.
A WEAK COLD FRONT WILL PASS THROUGH LATE SATURDAY AND SATURDAY
NIGHT. A FEW SHOWERS ARE POSSIBLE...BUT VFR CONDITIONS ARE LIKELY TO
PERSIST. MORE VFR CONDITIONS ARE EXPECTED EARLY NEXT WEEK FROM HIGH
PRESSURE. ANOTHER COLD FRONT ALONG WITH LOW PRESSURE MAY IMPACT THE
TERMINALS DURING THE MIDDLE PORTION OF NEXT WEEK.
&&
.MARINE...
A COLD FRONT WILL CROSS THE WATERS LATE TONIGHT. WINDS JUST AHEAD
OF THE FRONT WILL BE IN THE 10-15KT RANGE OUT OF THE SOUTH...THEN
SWITCH TO GUSTY NW AT 15-20KT FOR A FEW HRS. WINDS WILL REMAIN OF
THE WNW FOR THE REMAINDER OF FRI BUT ONLY PERIODICALLY GUSTING
TOWARD 20KT THRU THE MRNG AND SUBSIDING INTO THE AFTN FRIDAY.
HIGH PRESSURE WILL BUILD OVERHEAD FRIDAY INTO SATURDAY BEFORE A
REINFORCING COLD FRONT MOVES THROUGH LATE SATURDAY AND SATURDAY
NIGHT. HIGH PRESSURE WILL RETURN SUNDAY THROUGH EARLY NEXT WEEK
BEFORE LOW PRESSURE AND ANOTHER COLD FRONT POSSIBLY IMPACT THE
WATERS DURING THE MIDDLE PORTION OF NEXT WEEK.
A SMALL CRAFT ADVISORY IS IN EFFECT FRIDAY FOR NORTHWEST WINDS AHEAD
OF THE HIGH. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF
THE WATERS AHEAD OF THE COLD FRONT SATURDAY AFTERNOON AND BEHIND THE
COLD FRONT SATURDAY NIGHT INTO SUNDAY.
&&
.TIDES/COASTAL FLOODING...
SLY WINDS WILL CONTINUE TO CHANNEL OUT AHEAD OF AN APPROACHING
COLD FRONT. THIS HAS BUILT UP THE ANOMALIES CLOSER TO 1.5FT. THAT
COMBINED WITH THE NEAR FULL MOON AND ITS HIGH ASTRONOMICAL TIDES
IS CAUSING MINOR TIDAL INUNDATION FOR THE UPCOMING H.T. CYCLE
LATE THIS AFTN/EVE - OVER MOST DC/ALEX SITES AND THE MD CHES BAY.
A COLD FRONT LATE TONIGHT WILL BRING GUSTY NWLY WINDS THAT WILL
START TO CUT DOWN ON THESE POSITIVE ANOMALIES FOR FRI MORNING`S
HIGH TIDE.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...COASTAL FLOOD ADVISORY UNTIL 10 PM EDT THIS EVENING FOR DCZ001.
MD...COASTAL FLOOD ADVISORY UNTIL 7 PM EDT THIS EVENING FOR MDZ014-
018.
COASTAL FLOOD ADVISORY UNTIL 11 PM EDT THIS EVENING FOR MDZ007-
011.
VA...COASTAL FLOOD ADVISORY UNTIL 10 PM EDT THIS EVENING FOR VAZ054.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 2 PM EDT FRIDAY
FOR ANZ530>532-538>540.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 2 PM EDT FRIDAY
FOR ANZ533>537-541>543.
&&
$$
UPDATE...GMS
PREV DISCUSSION...CAS/BJL
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1216 PM CDT THU OCT 17 2013
UPDATED TO INCLUDE 18Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CDT THU OCT 17 2013
LATEST WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS SHOW TWO
FEATURES OF INTEREST IN THE SHORT TERM. THE MAIN FEATURE FOR OUR
FORECAST CONCERNS IS A SHORTWAVE DROPPING SOUTHEAST FROM
SASKATCHEWAN INTO THE NORTHERN HIGH PLAINS. THIS SHORTWAVE WILL PUSH
SOUTHEAST THEN EAST TODAY INTO TONIGHT... DRIVING A COLD FRONTAL
BOUNDARY THROUGH THE REGION AND KICKING OF SOME RAINFALL AS IT DOES
SO. THE SECOND FEATURE IS A SOUTHERN STREAM SHORTWAVE CENTERED NEAR
THE KANSAS/MISSOURI BORDER... WHICH WILL TRACK EAST-NORTHEAST AND
MAINLY WORK TO JUST INCREASE SOME MID-HIGH CLOUDS OVER THE EASTERN
PORTION OF THE AREA THIS MORNING AS IT HELPS ENHANCE MID-UPPER LEVEL
DEFORMATION OVER THAT AREA. MODEL GUIDANCE IS IN FAIRLY GOOD
AGREEMENT THROUGH THE SHORT TERM... WITH SIMILAR TIMING OF FROPA AND
PCPN ACROSS THE AREA. THE BEST COALESCENCE OF FORCING AND DEEP LAYER
SATURATION LOOKS TO OCCUR OVER THE NORTHERN AND CENTRAL PORTION OF
THE AREA THIS AFTERNOON INTO THIS EVENING... PRIMARILY BEHIND THE
COLD FRONT GIVEN FRONT-RELATIVE UPGLIDE AND DPVA WORKING TOGETHER IN
THAT AREA. THALER-QG DIAGNOSTICS DO A NICE JOB OF DEPICTING THE
OVERALL AREA OF FORCING PER ITS 700MB VERTICAL VELOCITIES... AND THE
Q-G INDUCED PCPN IS FOCUSED BEST OVER THE NORTH HALF OF THE CWFA.
HOWEVER... ENTIRE AREA HAS A DECENT SHOT OF SEEING AT LEAST SOME
PCPN AS THE FRONT MARCHES ACROSS THE AREA TODAY INTO TONIGHT.
IN ADDITION TO THE MAIN AREA OF PCPN WITH THE FRONT AND UPPER
WAVE... IT LOOKS LIKE THERE MAY BE A SEPARATE AREA OF LIGHT RAIN
LATER THIS MORNING INTO THIS AFTERNOON WHICH WOULD PRECEDE THAT MAIN
BAND OF PCPN. THE HIGH RES MODELS... HOPWRF... HRRR... HIRESW NMM
AND ARW... AND SPCNMM... ALL SUGGEST THE POTENTIAL FOR SOME LIGHT
RAIN TO DEVELOP NEAR AND EAST OF THE I-35 CORRIDOR LATER THIS
MORNING INTO THIS AFTERNOON. THIS APPEARS TO BE IN RESPONSE TO A
QUICK INCREASE IN MOISTURE APPARENT ON THE 295K ISENTROPIC SURFACE
OCCURRING IN CONJUNCTION WITH THE SURFACE ITSELF RISING AS COLDER AIR
PUSHES INTO THE REGION... ESSENTIALLY OFFSETTING THE WEAK NEGATIVE
PRESSURE ADVECTION OCCURRING AT THAT TIME. 11-3.9 MICRON IMAGERY
OVER THE PAST FEW HOURS HAS SHOWN MID-HIGH CLOUDS INCREASING OVER
CENTRAL MINNESOTA... ROUGHLY IN THE SAME AREA WHERE THE
AFOREMENTIONED HIGH RES MODELS ARE GENERATING SOME MID-UPPER LEVEL
REFLECTIVITY WHICH THEY EVENTUALLY GET DOWN CLOSER TO THE GROUND
THIS MORNING INTO THIS AFTERNOON. OVERALL.. WOULD NOT EXPECT THIS
EASTERN AREA OF PCPN TO PRODUCE MUCH... AND THERE WILL LIKELY BE A
GAP BETWEEN IT AND THE MAIN BAND OF PCPN ARRIVING FROM THE WEST
LATER TODAY. HOWEVER... PLAYED THINGS SIMPLE IN THE FORECAST FOR THE
TIME BEING SINCE THINGS HAVE OBVIOUSLY NOT YET DEVELOPED... AND JUST
ALLOWED FOR SOME LOW POPS TO SNEAK INTO THE EASTERN PORTION OF THE
AREA A BIT EARLIER TODAY... WITH THE HIGHER POPS STILL HOLDING OFF
UNTIL LATER IN THE AFTERNOON INTO THE EVENING. OTHERWISE... STUCK
CLOSE TO THE GOING FORECAST THROUGH TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 310 AM CDT THU OCT 17 2013
GENERALLY THE LONG WAVE PATTERN WILL BE CONSISTENT OVER THE NEXT
WEEK WITH A LONG WAVE TROUGH ACROSS THE EASTERN CONUS...AND A
UPPER RIDGE CENTERED OFF THE WESTERN CONUS. THERE IS A TREND OF
THE UPPER RIDGE SLOWLY MOVING EAST-SOUTHEAST INTO THE INTERIOR OF
THE WESTERN U.S. BUT GENERALLY THIS WILL ONLY AFFECT THE ROCKIES
SENSIBLE WX. THIS PATTERN IS COLD FOR THE UPPER MIDWEST...BUT
GENERALLY LOW CHC/S OF WIDESPREAD PRECIPITATION. THIS IS MAINLY
DUE TO TIMING OF SHRTWV/S AND DIFFERENCES IN THE DETERMINISTIC
MODEL MASS FIELDS...ESPECIALLY MOISTURE/TEMPERATURE ADVECTION.
ONE OF THE MAIN TRENDS IS THE THERMAL PROFILE WILL FALL OVER THE
NEXT FEW DAYS...WHICH MEANS A BETTER CHC OF THE PRECIPITATION TO
FALL AS SNOW...ESPECIALLY PAST SUNDAY AS 85H TEMPS FALL BLW -4C.
THE GROUND IS WAY TOO WARM FOR ANY ACCUMULATING SNOWFALL...BUT IF
ANY OF THE SYSTEMS OVER THE WEEKEND...OR NEXT WEEK HAVE ENOUGH
ENERGY TO GENERATE HEAVIER SNOW BURST...I COULD SEE A LIGHT
DUSTING ON GRASSY SURFACES. THIS IS TYPICALLY NOT THE NORM FOR
MID/LATE OCTOBER...ESPECIALLY DUE TO SIMILAR SYSTEMS IN THE PAST
WHICH WERE MUCH COLDER...BUT STILL DID NOT PRODUCE ANY SIGNIFICANT
SNOWFALL.
ANOMALY EXTREMES OR STANDARD DEVIATIONS REMAIN BLW AVERAGE...BUT
NOT TOO FAR OFF WHICH IS TYPICAL FOR MID/LATE OCTOBER. ONLY THE
DEEP SOUTH/SE U.S. HAS ANY TYPE OF MUCH BLW TEMPS DUE TO THE DEPTH
OF THIS LONG WAVE TROUGH NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1215 PM CDT THU OCT 17 2013
COLD FRONT JUST PUSHED THROUGH AXN AND IS EXPECTED TO CONTINUE ESE
THROUGH THE AFTN/EVE HRS. MAIN BAND OF -RA BEHIND THE FRONT WITH
MVFR AND OCCASIONAL IFR CIGS. WHEN THE HEAVIER RA (CURRENTLY IN E SD)
MOVES THROUGH MAINLY AXN/STC/RWF...EXPECTED CIGS TO DROP
DOWN TO IFR LEVELS WHILE VSBYS STAY GENERALLY ABOVE 4SM. -RA WILL
MOVE INTO THE EASTERN TAF SITES AROUND 00Z WITH CIGS/VSBYS DIPPING
DOWN INTO MVFR LEVELS LATER IN THE NIGHT. NOT CONFIDENT ENOUGH TO
GO LOWER OUT EAST...WOULD LIKE TO SEE HOW CONDITIONS MATERIALIZE
FURTHER TO THE WEST BEFORE ADDING TEMPO GROUPS OR GOING TOO LOW IN
THERMS OF CIGS. VFR CONDS WILL DEVELOP LATER IN THE NIGHT AND SPREAD
EASTWARD AS WEAK (AND BRIEF) SFC RIDGING BUILDS IN.
KMSP...-RA TO BEGIN AROUND 22Z WITH THE PASSAGE OF THE
FRONT...THEN HEAVIER SHOWERS COMING IN AFT 01Z. CAPPED CONDITIONS
AT MVFR FOR NOW...BUT CONDS COULD DIP INTO THE IFR RANGE FOR A
TIME OVERNIGHT BASED ON DEVELOPING CONDS IN FAR W MN. CLEARING
EXPECTED LATE TONIGHT AFTER THE RAIN ENDS WITH VFR FOR THE
REMAINDER OF THE PERIOD. WINDS WILL STAY ELEVATED OVERNIGHT BEHIND
THE FRONT...THEN SLACKEN A BIT ON FRI WHILE MAINTAINING A WESTERLY
COMPONENT.
/OUTLOOK FOR KMSP/
FRIDAY NIGHT...MVFR CEILINGS/VISIBILITIES POSSIBLE WITH A CHANCE
OF -RA. WEST WIND 5 TO 10 KT.
SATURDAY...MVFR CEILINGS POSSIBLE EARLY WITH A CHANCE OF -RA.
NORTHWEST WIND 5 TO 15 KT.
SATURDAY NIGHT...VFR. NORTHWEST WIND 5 TO 10 KT DECREASING TO 5 KT
OR LESS.
SUNDAY...VFR. VARIABLE WIND 5 KT OR LESS.
SUNDAY NIGHT...MVFR CEILINGS/VISIBILITIES POSSIBLE LATE WITH A
CHANCE OF -RA/-SN. EAST WIND 5 TO 10 KT.
MONDAY...MVFR CEILINGS/VISIBILITIES POSSIBLE EARLY WITH A CHANCE
OF -RA/-SN. NORTHEAST WIND LESS THAN 10 KT BECOMING NORTHWEST.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...
SHORT TERM...
LONG TERM...JLT
AVIATION...JCA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
537 AM CDT THU OCT 17 2013
.UPDATE...
ISSUED AT 536 AM CDT THU OCT 17 2013
UPDATED TO INCLUDE 12Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CDT THU OCT 17 2013
LATEST WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS SHOW TWO
FEATURES OF INTEREST IN THE SHORT TERM. THE MAIN FEATURE FOR OUR
FORECAST CONCERNS IS A SHORTWAVE DROPPING SOUTHEAST FROM
SASKATCHEWAN INTO THE NORTHERN HIGH PLAINS. THIS SHORTWAVE WILL PUSH
SOUTHEAST THEN EAST TODAY INTO TONIGHT... DRIVING A COLD FRONTAL
BOUNDARY THROUGH THE REGION AND KICKING OF SOME RAINFALL AS IT DOES
SO. THE SECOND FEATURE IS A SOUTHERN STREAM SHORTWAVE CENTERED NEAR
THE KANSAS/MISSOURI BORDER... WHICH WILL TRACK EAST-NORTHEAST AND
MAINLY WORK TO JUST INCREASE SOME MID-HIGH CLOUDS OVER THE EASTERN
PORTION OF THE AREA THIS MORNING AS IT HELPS ENHANCE MID-UPPER LEVEL
DEFORMATION OVER THAT AREA. MODEL GUIDANCE IS IN FAIRLY GOOD
AGREEMENT THROUGH THE SHORT TERM... WITH SIMILAR TIMING OF FROPA AND
PCPN ACROSS THE AREA. THE BEST COALESCENCE OF FORCING AND DEEP LAYER
SATURATION LOOKS TO OCCUR OVER THE NORTHERN AND CENTRAL PORTION OF
THE AREA THIS AFTERNOON INTO THIS EVENING... PRIMARILY BEHIND THE
COLD FRONT GIVEN FRONT-RELATIVE UPGLIDE AND DPVA WORKING TOGETHER IN
THAT AREA. THALER-QG DIAGNOSTICS DO A NICE JOB OF DEPICTING THE
OVERALL AREA OF FORCING PER ITS 700MB VERTICAL VELOCITIES... AND THE
Q-G INDUCED PCPN IS FOCUSED BEST OVER THE NORTH HALF OF THE CWFA.
HOWEVER... ENTIRE AREA HAS A DECENT SHOT OF SEEING AT LEAST SOME
PCPN AS THE FRONT MARCHES ACROSS THE AREA TODAY INTO TONIGHT.
IN ADDITION TO THE MAIN AREA OF PCPN WITH THE FRONT AND UPPER
WAVE... IT LOOKS LIKE THERE MAY BE A SEPARATE AREA OF LIGHT RAIN
LATER THIS MORNING INTO THIS AFTERNOON WHICH WOULD PRECEDE THAT MAIN
BAND OF PCPN. THE HIGH RES MODELS... HOPWRF... HRRR... HIRESW NMM
AND ARW... AND SPCNMM... ALL SUGGEST THE POTENTIAL FOR SOME LIGHT
RAIN TO DEVELOP NEAR AND EAST OF THE I-35 CORRIDOR LATER THIS
MORNING INTO THIS AFTERNOON. THIS APPEARS TO BE IN RESPONSE TO A
QUICK INCREASE IN MOISTURE APPARENT ON THE 295K ISENTROPIC SURFACE
OCCURRING IN CONJUNCTION WITH THE SURFACE ITSELF RISING AS COLDER AIR
PUSHES INTO THE REGION... ESSENTIALLY OFFSETTING THE WEAK NEGATIVE
PRESSURE ADVECTION OCCURRING AT THAT TIME. 11-3.9 MICRON IMAGERY
OVER THE PAST FEW HOURS HAS SHOWN MID-HIGH CLOUDS INCREASING OVER
CENTRAL MINNESOTA... ROUGHLY IN THE SAME AREA WHERE THE
AFOREMENTIONED HIGH RES MODELS ARE GENERATING SOME MID-UPPER LEVEL
REFLECTIVITY WHICH THEY EVENTUALLY GET DOWN CLOSER TO THE GROUND
THIS MORNING INTO THIS AFTERNOON. OVERALL.. WOULD NOT EXPECT THIS
EASTERN AREA OF PCPN TO PRODUCE MUCH... AND THERE WILL LIKELY BE A
GAP BETWEEN IT AND THE MAIN BAND OF PCPN ARRIVING FROM THE WEST
LATER TODAY. HOWEVER... PLAYED THINGS SIMPLE IN THE FORECAST FOR THE
TIME BEING SINCE THINGS HAVE OBVIOUSLY NOT YET DEVELOPED... AND JUST
ALLOWED FOR SOME LOW POPS TO SNEAK INTO THE EASTERN PORTION OF THE
AREA A BIT EARLIER TODAY... WITH THE HIGHER POPS STILL HOLDING OFF
UNTIL LATER IN THE AFTERNOON INTO THE EVENING. OTHERWISE... STUCK
CLOSE TO THE GOING FORECAST THROUGH TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 310 AM CDT THU OCT 17 2013
GENERALLY THE LONG WAVE PATTERN WILL BE CONSISTENT OVER THE NEXT
WEEK WITH A LONG WAVE TROUGH ACROSS THE EASTERN CONUS...AND A
UPPER RIDGE CENTERED OFF THE WESTERN CONUS. THERE IS A TREND OF
THE UPPER RIDGE SLOWLY MOVING EAST-SOUTHEAST INTO THE INTERIOR OF
THE WESTERN U.S. BUT GENERALLY THIS WILL ONLY AFFECT THE ROCKIES
SENSIBLE WX. THIS PATTERN IS COLD FOR THE UPPER MIDWEST...BUT
GENERALLY LOW CHC/S OF WIDESPREAD PRECIPITATION. THIS IS MAINLY
DUE TO TIMING OF SHRTWV/S AND DIFFERENCES IN THE DETERMINISTIC
MODEL MASS FIELDS...ESPECIALLY MOISTURE/TEMPERATURE ADVECTION.
ONE OF THE MAIN TRENDS IS THE THERMAL PROFILE WILL FALL OVER THE
NEXT FEW DAYS...WHICH MEANS A BETTER CHC OF THE PRECIPITATION TO
FALL AS SNOW...ESPECIALLY PAST SUNDAY AS 85H TEMPS FALL BLW -4C.
THE GROUND IS WAY TOO WARM FOR ANY ACCUMULATING SNOWFALL...BUT IF
ANY OF THE SYSTEMS OVER THE WEEKEND...OR NEXT WEEK HAVE ENOUGH
ENERGY TO GENERATE HEAVIER SNOW BURST...I COULD SEE A LIGHT
DUSTING ON GRASSY SURFACES. THIS IS TYPICALLY NOT THE NORM FOR
MID/LATE OCTOBER...ESPECIALLY DUE TO SIMILAR SYSTEMS IN THE PAST
WHICH WERE MUCH COLDER...BUT STILL DID NOT PRODUCE ANY SIGNIFICANT
SNOWFALL.
ANOMALY EXTREMES OR STANDARD DEVIATIONS REMAIN BLW AVERAGE...BUT
NOT TOO FAR OFF WHICH IS TYPICAL FOR MID/LATE OCTOBER. ONLY THE
DEEP SOUTH/SE U.S. HAS ANY TYPE OF MUCH BLW TEMPS DUE TO THE DEPTH
OF THIS LONG WAVE TROUGH NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 536 AM CDT THU OCT 17 2013
VFR CONDITIONS WILL GIVE WAY TO MVFR TODAY INTO TONIGHT AS AN
UPPER LEVEL TROUGH AND SURFACE COLD FRONT OVER THE NORTHERN PLAINS
MOVE THROUGH THE REGION. SOME IFR CONDITIONS... PARTICULARLY WITH
RESPECT TO CEILINGS... LOOK POSSIBLE BEHIND THE FRONT TONIGHT...
ALTHOUGH IT IS TOUGH TO HIT THEM TOO HARD AT THIS POINT SINCE THEY
WILL BE DEVELOPING AS THE SYSTEM MOVES EAST. VISIBILITIES COULD
ALSO GET INTO THE IFR RANGE WITH ANY HEAVY PCPN THAT MOVES THROUGH
THE AREA. OVERALL.. MOST LOCATIONS LOOK TO SEE A 3 TO 5 HOUR
WINDOW OF MAINLY LIGHT PCPN... WITH THE NORTHERN PORTION OF THE
AREA LIKELY SEEING A BETTER CHANCE AT HEAVIER ACTIVITY. CONDITIONS
SHOULD IMPROVE FAIRLY QUICKLY FROM WEST TO EAST AFTER 06Z TONIGHT.
KMSP...TAF REFLECTS EXPECTATIONS WITH GOOD CONFIDENCE IN THE
OVERALL TREND. HOWEVER... TIMING OF CEILING/VISIBILITY CHANGES
COULD DIFFER BY +/- 3 HOURS OR SO FROM WHAT IS FORECAST GIVEN
UNCERTAINTY IN THE TIMING OF THE FRONTAL PASSAGE AND PCPN.
CEILINGS AND/OR VISIBILITY COULD ALSO BE LOWER THAN INDICATED...
SO WILL NEED TO MONITOR THROUGH THE DAY AS THINGS EVOLVE UPSTREAM.
/OUTLOOK FOR KMSP/
FRIDAY AFTERNOON...VFR. WEST WIND 5 TO 10 KT.
FRIDAY NIGHT...MVFR CEILINGS/VISIBILITIES POSSIBLE WITH A CHANCE
OF -RA. WEST WIND 5 TO 10 KT.
SATURDAY...MVFR CEILINGS POSSIBLE EARLY WITH A CHANCE OF -RA.
NORTHWEST WIND 5 TO 15 KT.
SATURDAY NIGHT...VFR. NORTHWEST WIND 5 TO 10 KT DECREASING TO 5 KT
OR LESS.
SUNDAY...VFR. VARIABLE WIND 5 KT OR LESS.
SUNDAY NIGHT...MVFR CEILINGS/VISIBILITIES POSSIBLE LATE WITH A
CHANCE OF -RA/-SN. EAST WIND 5 TO 10 KT.
MONDAY...MVFR CEILINGS/VISIBILITIES POSSIBLE EARLY WITH A CHANCE
OF -RA/-SN. NORTHEAST WIND LESS THAN 10 KT BECOMING NORTHWEST.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...
SHORT TERM...
LONG TERM...JLT
AVIATION...
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
328 AM CDT THU OCT 17 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CDT THU OCT 17 2013
LATEST WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS SHOW TWO
FEATURES OF INTEREST IN THE SHORT TERM. THE MAIN FEATURE FOR OUR
FORECAST CONCERNS IS A SHORTWAVE DROPPING SOUTHEAST FROM
SASKATCHEWAN INTO THE NORTHERN HIGH PLAINS. THIS SHORTWAVE WILL PUSH
SOUTHEAST THEN EAST TODAY INTO TONIGHT... DRIVING A COLD FRONTAL
BOUNDARY THROUGH THE REGION AND KICKING OF SOME RAINFALL AS IT DOES
SO. THE SECOND FEATURE IS A SOUTHERN STREAM SHORTWAVE CENTERED NEAR
THE KANSAS/MISSOURI BORDER... WHICH WILL TRACK EAST-NORTHEAST AND
MAINLY WORK TO JUST INCREASE SOME MID-HIGH CLOUDS OVER THE EASTERN
PORTION OF THE AREA THIS MORNING AS IT HELPS ENHANCE MID-UPPER LEVEL
DEFORMATION OVER THAT AREA. MODEL GUIDANCE IS IN FAIRLY GOOD
AGREEMENT THROUGH THE SHORT TERM... WITH SIMILAR TIMING OF FROPA AND
PCPN ACROSS THE AREA. THE BEST COALESCENCE OF FORCING AND DEEP LAYER
SATURATION LOOKS TO OCCUR OVER THE NORTHERN AND CENTRAL PORTION OF
THE AREA THIS AFTERNOON INTO THIS EVENING... PRIMARILY BEHIND THE
COLD FRONT GIVEN FRONT-RELATIVE UPGLIDE AND DPVA WORKING TOGETHER IN
THAT AREA. THALER-QG DIAGNOSTICS DO A NICE JOB OF DEPICTING THE
OVERALL AREA OF FORCING PER ITS 700MB VERTICAL VELOCITIES... AND THE
Q-G INDUCED PCPN IS FOCUSED BEST OVER THE NORTH HALF OF THE CWFA.
HOWEVER... ENTIRE AREA HAS A DECENT SHOT OF SEEING AT LEAST SOME
PCPN AS THE FRONT MARCHES ACROSS THE AREA TODAY INTO TONIGHT.
IN ADDITION TO THE MAIN AREA OF PCPN WITH THE FRONT AND UPPER
WAVE... IT LOOKS LIKE THERE MAY BE A SEPARATE AREA OF LIGHT RAIN
LATER THIS MORNING INTO THIS AFTERNOON WHICH WOULD PRECEDE THAT MAIN
BAND OF PCPN. THE HIGH RES MODELS... HOPWRF... HRRR... HIRESW NMM
AND ARW... AND SPCNMM... ALL SUGGEST THE POTENTIAL FOR SOME LIGHT
RAIN TO DEVELOP NEAR AND EAST OF THE I-35 CORRIDOR LATER THIS
MORNING INTO THIS AFTERNOON. THIS APPEARS TO BE IN RESPONSE TO A
QUICK INCREASE IN MOISTURE APPARENT ON THE 295K ISENTROPIC SURFACE
OCCURRING IN CONJUNCTION WITH THE SURFACE ITSELF RISING AS COLDER AIR
PUSHES INTO THE REGION... ESSENTIALLY OFFSETTING THE WEAK NEGATIVE
PRESSURE ADVECTION OCCURRING AT THAT TIME. 11-3.9 MICRON IMAGERY
OVER THE PAST FEW HOURS HAS SHOWN MID-HIGH CLOUDS INCREASING OVER
CENTRAL MINNESOTA... ROUGHLY IN THE SAME AREA WHERE THE
AFOREMENTIONED HIGH RES MODELS ARE GENERATING SOME MID-UPPER LEVEL
REFLECTIVITY WHICH THEY EVENTUALLY GET DOWN CLOSER TO THE GROUND
THIS MORNING INTO THIS AFTERNOON. OVERALL.. WOULD NOT EXPECT THIS
EASTERN AREA OF PCPN TO PRODUCE MUCH... AND THERE WILL LIKELY BE A
GAP BETWEEN IT AND THE MAIN BAND OF PCPN ARRIVING FROM THE WEST
LATER TODAY. HOWEVER... PLAYED THINGS SIMPLE IN THE FORECAST FOR THE
TIME BEING SINCE THINGS HAVE OBVIOUSLY NOT YET DEVELOPED... AND JUST
ALLOWED FOR SOME LOW POPS TO SNEAK INTO THE EASTERN PORTION OF THE
AREA A BIT EARLIER TODAY... WITH THE HIGHER POPS STILL HOLDING OFF
UNTIL LATER IN THE AFTERNOON INTO THE EVENING. OTHERWISE... STUCK
CLOSE TO THE GOING FORECAST THROUGH TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 310 AM CDT THU OCT 17 2013
GENERALLY THE LONG WAVE PATTERN WILL BE CONSISTENT OVER THE NEXT
WEEK WITH A LONG WAVE TROUGH ACROSS THE EASTERN CONUS...AND A
UPPER RIDGE CENTERED OFF THE WESTERN CONUS. THERE IS A TREND OF
THE UPPER RIDGE SLOWLY MOVING EAST-SOUTHEAST INTO THE INTERIOR OF
THE WESTERN U.S. BUT GENERALLY THIS WILL ONLY AFFECT THE ROCKIES
SENSIBLE WX. THIS PATTERN IS COLD FOR THE UPPER MIDWEST...BUT
GENERALLY LOW CHC/S OF WIDESPREAD PRECIPITATION. THIS IS MAINLY
DUE TO TIMING OF SHRTWV/S AND DIFFERENCES IN THE DETERMINISTIC
MODEL MASS FIELDS...ESPECIALLY MOISTURE/TEMPERATURE ADVECTION.
ONE OF THE MAIN TRENDS IS THE THERMAL PROFILE WILL FALL OVER THE
NEXT FEW DAYS...WHICH MEANS A BETTER CHC OF THE PRECIPITATION TO
FALL AS SNOW...ESPECIALLY PAST SUNDAY AS 85H TEMPS FALL BLW -4C.
THE GROUND IS WAY TOO WARM FOR ANY ACCUMULATING SNOWFALL...BUT IF
ANY OF THE SYSTEMS OVER THE WEEKEND...OR NEXT WEEK HAVE ENOUGH
ENERGY TO GENERATE HEAVIER SNOW BURST...I COULD SEE A LIGHT
DUSTING ON GRASSY SURFACES. THIS IS TYPICALLY NOT THE NORM FOR
MID/LATE OCTOBER...ESPECIALLY DUE TO SIMILAR SYSTEMS IN THE PAST
WHICH WERE MUCH COLDER...BUT STILL DID NOT PRODUCE ANY SIGNIFICANT
SNOWFALL.
ANOMALY EXTREMES OR STANDARD DEVIATIONS REMAIN BLW AVERAGE...BUT
NOT TOO FAR OFF WHICH IS TYPICAL FOR MID/LATE OCTOBER. ONLY THE
DEEP SOUTH/SE U.S. HAS ANY TYPE OF MUCH BLW TEMPS DUE TO THE DEPTH
OF THIS LONG WAVE TROUGH NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1107 PM CDT WED OCT 16 2013
CLOUDS WILL STEADILY INCRS OVERNIGHT THRU TMRW MRNG...FORMING
UPPER-LEVEL DECKS THAT WILL GRADUALLY LOWER AND INCRS IN COVERAGE.
WI SITES WILL HAVE THE LONGEST DURATION OF CLR SKIES AND LGT WINDS
OVERNIGHT. KEAU HAS ALREADY REPORTED FOG AND IT IS NOT
UNREASONABLE FOR THE SAME TO HAPPEN AT KRNH SO HAVE INDICATED
DEGRADED CONDITIONS AT BOTH THOSE SITES. AM NOT EXPECTING FOG AS
THE MN SITES WITH THE INCREASED CLOUD COVER AND SLIGHTLY ELEVATED
WINDS. AS DECKS LOWER TMRW AFTN INTO TMRW EVE...MN TAF SITES WILL
LIKELY EXPERIENCE MVFR CIGS BEFORE 00Z TMRW EVE ALONG WITH
POSSIBLY -RA BEFORE 21Z. AM NOT LOOKING FOR PRECIP THAT WILL
DEGRADE VSBY BELOW 6SM...EXCEPT FOR POSSIBLY KAXN WHICH WILL BE IN
CLOSEST PROXIMITY TO UPPER LEVEL SUPPORT PRODUCING THE HEAVIEST
RAIN. THE WINDOW FOR PRECIP IS NOT MUCH...POSSIBLY 4 TO 6 HOURS AT
MOST. PRECIP WILL GRADUALLY END AFTER 02-04Z TMRW EVE...WITH CONDS
IMPROVING TO VFR TMRW NIGHT.
KMSP...VFR CONDS EXPECTED TNGT THRU MOST OF TMRW. CLOUDS WILL
INCRS IN COVERAGE THROUGHOUT THE DAY TMRW AND DECKS WILL STEADILY
LOWER. AM EXPECTING CEILINGS TO REMAIN WITHIN VFR RANGE THRU TMRW
AFTN...THEN WILL LOOK FOR CEILINGS TO DROP INTO UPPER-MVFR RANGE
TMRW EVE AS -RA DEVELOPS. AM NOT EXPECTING CEILING TO DROP TO LESS
THAN 2 KFT. AHEAD OF THE COLD FROPA...LGT SW WINDS WILL PREVAIL.
TIMING OF THE FROPA WILL BE LATE MRNG TO EARLY AFTN...THEN WINDS
WILL SWING TO NW AND INCRS TO ARND 10 KT. COULD BE SOME GUSTINESS
TMRW AFTN BUT CONFIDENCE TOO LOW TO INCLUDE ATTM. WINDOW FOR MVFR
CONDS LOOKS TO BE APPROXIMATELY 21Z-04Z...POSSIBLY AN HOUR EITHER
WAY...THEN CONDS WILL IMPROVE TO VFR TMRW NIGHT INTO FRI MRNG.
/OUTLOOK FOR KMSP/
FRI...VFR. MVFR CIGS LIKELY WITH CHC -RA OR -SN LATE FRIDAY NIGHT.
WINDS W 5 KTS.
SAT...VFR. CHC MVFR CIGS AND -RA. WINDS WNW 10-15 KTS.
SUN...VFR. CHC MVFR AND -RA/-SN TURNING TO -SN SUNDAY NIGHT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...TRH
LONG TERM...JLT
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
949 PM CDT Fri Oct 18 2013
.UPDATE...
Issued at 949 PM CDT FRI OCT 18 2013
The going forecast remains on track and only minor changes were made
to temperatures and PoPs to keep up with trends in each. Potential
remains for some patchy frost tonight but there are a few things
that may hinder development despite temperatures falling into the
32-35 degree range across most of the area. The biggest is that it
looks like winds will not be calm and generally be around 5 mph or
so, with the exception of some very sheltered areas. The other is
that there is some uncertainty with how much cloud cover will be
present in the area. Some recent runs of short-term models including
the RAP and HRRR start to develop and/or move lower clouds back into
the area late tonight. Latest fog imagery is showing an area of IFR
stratus forming over eastern KS as the higher level clouds move out.
Short-range models drift this area east through overnight,
encompassing most of western Missouri through the better part of the
overnight. These two factors negatively impact the radiational
cooling potential and thus potential for frost. Will continue to
monitor trends but at this time widespread frost does not seem
likely.
&&
.SHORT TERM...(This Evening through Sunday Night)
Issued at 331 PM CDT FRI OCT 18 2013
For this evening, the main concern will be moderate rain moving
through the southern two thirds of the forecast area in advance of a
southeastward moving shortwave trough. A dry boundary layer and cold
temperatures aloft have allowed a few pellets of sleet to mix with
rain especially as the column initially saturates, and has also
allowed a few flakes of snow to mix with the lighter rain on the
back side of the precipitation shield. Rainfall amounts should be
around a few tenths to a quarter of an inch, and no accumulation of
wintry precipitation is expected. As frontogenesis weakens late this
afternoon into the early evening, precipitation should lighten
considerably and may start to break up a bit as it heads southeast.
After the precipitation clears out during the late evening to early
overnight hours, temperatures and frost potential will be the main
concern. The degree of clearing will be uncertain with additional
clouds working down across Iowa and portions of northern Missouri,
and non-zero surface winds will also make cooling of the ground
layer a bit more difficult, so have held off on a frost advisory for
now. However, temperatures will not have to fall far to get into the
lower to mid 30s since readings have fallen into the upper 30s
across many areas currently experiencing precipitation, so some
precaution will be needed with sensitive vegetation tonight.
Temperatures will slowly recover on Saturday, then will be much
warmer on Sunday as breezy west winds and sunshine help highs climb
into the upper 60s to even lower 70s. Lows should not be a concern
on Sunday or Monday mornings, with better moisture and southerly
winds helping temperatures stay in the upper 30s to mid 40s both
nights. No additional precipitation is expected through Sunday night.
.LONG TERM...(Monday through Friday)
Issued at 349 PM CDT FRI OCT 18 2013
Medium range models maintain a cold pattern during most of the
period as the mean upper trough over the eastern half of the nation
gradually shifts east. A couple of fast moving clipper type systems
are expected to zip down the back side of the upper trough with the
initial one possibly affecting the CWA on Tuesday. The 12z GFS came
into agreement with the 00z ECMWF but now the 12z ECMWF tracks the
clipper further east. Enough uncertainty due to model waffling that
30-40% PoPs are high enough. Cold air advection through Monday night
in previous forecasts called into the possibility of freezing
temperatures is somewhat mitigated due to the expected increase in
cloud cover. So, have raised overnight lows for Monday night.
Latest ECMWF shows stronger cold air advection behind Tuesday system
for Wednesday but believe that is overdone. Nonetheless, the
overriding theme from Wednesday on is well below average
temperatures. A continued northerly component of the boundary layer
winds will funnel the shallow cold air from the Canadian provinces
southward despite rising heights aloft.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 949 PM CDT FRI OCT 18 2013
An area of IFR stratus has develop over eastern KS and western MO,
generally along Interstate 70. Short-range models have started to
indicate these clouds and drift them east through the overnight. Have
amended the TAFS to carry IFR ceilings until late tonight, around
09Z. Ceilings should start to improve after this time as the stratus
drifts into central and northern MO.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...CDB
SHORT TERM...Laflin
LONG TERM...MJ
AVIATION...CDB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
322 PM CDT THU OCT 17 2013
.SHORT TERM...TONIGHT THROUGH SUNDAY.
NORTHWESTERLY FLOW WITH A SERIES OF EMBEDDED WAVES WILL PREVAIL
OVER FORECAST AREA THROUGH THE WEEKEND WITH SOME WARMING EXPECTED.
FOR TONIGHT...FIRST IN SEVERAL WAVES WILL BE TRACKING FM DAKOTAS
INTO MINNESOTA SPREADING CLOUDS ACROSS AREA INTO EARLY TONIGHT
BEFORE PROBABLY DECREASING AFT 06Z. 18Z RAP AND 12Z 4KM WRF AND
SOME HOP WRF MEMBERS SUGGESTED SOME VERY LIGHT PRECIP COULD CLIP
NERN ZONES EARLY. ANOTHER WAVE MOVING TOWARD KS BY MORNING COULD
SPREAD SOME MID/HIGH CLOUDS TOWARD SRN AND ESPECIALLY SWRN ZONES
BY MORNING. THE VARIABLE CLOUDS...SOME WIND AND INITIALLY MODEST
DWPTS WL LEAD TO KEEPING MOST LOWS A BIT ABOVE GUIDANCE.
LITTLE CHANGE TO FRIDAY...KEPT IN SMALL POPS EXTREME SOUTH DUE TO
SRN WAVE...ALTHOUGH APPEARS BULK OF ANY PRECIP COULD REMAIN TO OUR
SOUTH. ALSO SHARP MID LVL TROUGH AXIS MOVING INTO ERN NEBRASKA
TOWARD 00Z COULD ALLOW SOME SHOWER DEVELOPMENT AS H5 TEMPS IN
MINUS UPPER 20S C MOVE OVER AREA. SPREAD SMALL CHANCES A BIT
FARTHER S. SOMEWHAT DISCOUNTED NAM IN DOWNSLOPE MOISTURE LACKING
FLOW BUT THIS COULD FACILITATE FUTURE CHANGES. DID TRIM TEMPS BACK
A FEW DEGREES DUE TO EXPECTED CLOUDS...BUT KEPT THEM ON HIGH SIDE
OF GUIDANCE.
AFTER TROUGH PASSES FRIDAY TEMPERATURES SHOULD BE WARMING SATURDAY
AND SUNDAY AHEAD OF A STRONGER WAVE THAT WILL ARRIVE LATE SUNDAY.
KEPT FORECAST DRY IN WARM ADVECTION AHEAD OF THIS WAVE...BUT CAN
NOT RULE OUT SOME NEED IN LATER FORECASTS. TRENDED MOST MAX
TEMPERATURES UPWARD BOTH DAYS TO REFLECT FORECAST H85 TEMPS...BUT
DIDN/T MIX TO THAT DEPTH DUE TO POSSIBLE CLOUDS.
CHERMOK
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY.
THE REGION WILL REMAIN IN NORTHWEST FLOW ALOFT AS A BROAD TROUGH
REMAINS IN PLACE TO OUR EAST WHILE AN AMPLIFIED RIDGE REMAINS OVER
THE WESTERN STATES. THIS WILL ALLOW A COLD CANADIAN AIRMASS TO DROP
INTO THE NORTHERN PLAINS AND UPPER MIDWEST. THERE CONTINUES TO BE
SOME DISAGREEMENT AS TO HOW FAR WEST THE COLD AIRMASS WILL
REACH...HOWEVER THE TREND CONTINUES TO BE COLD FOR NEXT WEEK WITH
HIGHS IN THE LOW 50S AND LOWS IN THE LOWER TO MID 30S. SOME WEAK
RECOVERY BY THURSDAY MAY BRING HIGHS UP INTO THE MID TO UPPER 50S.
KERN
&&
.AVIATION...
18Z TAFS FOR KOMA...KLNK AND KOFK.
COLD FRONT WAS MOVING INTO AREA AT 18Z WITH KOFK BEHIND THE
FRONT ALREADY. MVFR CIGS AND GUSTY NW WINDS WILL SPREAD INTO KOMA
AND KLNK THROUGH 23Z WITH WINDS DIMINISHING AND VFR CIGS
DEVELOPING THEREAFTER. MODELS DO NOT HANDLE SKY CONDITIONS VERY
WELL SO MAY HAVE TO EXTEND MVFR CIGS INTO THE EVENING.
FOBERT
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
352 PM EDT THU OCT 17 2013
.SYNOPSIS...
WEAK HIGH PRESSURE AREA DEPARTS EARLY THIS EVENING AS A FRONTAL
SYSTEM MOVES ACROSS THE NORTH COUNTRY FROM THE SOUTHWEST TONIGHT.
CONDITIONS GRADUALLY IMPROVE FRIDAY MORNING AS ANOTHER AREA OF
WEAK HIGH PRESSURE BUILDS BACK IN. UNSETTLED WEATHER RETURNS ON
SATURDAY AND SATURDAY NIGHT WITH A TURN TOWARD SEASONABLY COOLER
WEATHER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM FRIDAY MORNING/...
AS OF 340 PM EDT THURSDAY...PARTLY CLOUDY SKIES CONTINUE IN MANY
AREAS ACROSS THE NORTH COUNTRY LATE THIS AFTERNOON...THOUGH SOME
LINGERING LAKE EFFECT MOISTURE RESULTING IN MOSTLY OVERCAST SKIES
IN THE ADIRONDACKS. HOWEVER...CHANGEABLE WEATHER CONDITIONS
EXPECTED LATE AFTERNOON INTO THE EVENING AS VISIBLE SATELLITE
REVEALS A BROAD SHIELD OF CLOUDINESS QUICKLY SPREADING
NORTHEASTWARD FROM THE OHIO VALLEY AND THE CENTRAL/LOWER
APPALACHIANS. WATER VAPOR AND RUC ANALYSES REVEAL A RATHER POTENT
MID-LEVEL SHORTWAVE TROUGH MOVING NORTHEASTWARD FROM THE LOWER
OHIO VALLEY...WITH A WEAK SFC CYCLONE EVIDENT IN LATE AFTERNOON
SFC ANALYSIS CENTERED NEAR SOUTHERN WEST VIRGINIA. LOOK FOR A
MARKED INCREASE IN CLOUD COVER AREAWIDE EARLY THIS EVENING AS
BOTH THE MID-LEVEL TROUGH AND ASSOCIATED SFC CYCLONE PUSH
NORTHEASTWARD.
GUIDANCE REMAINS IN PRETTY GOOD AGREEMENT REGARDING TIMING AND
QPF WITH THIS APPROACHING SYSTEM. THERE`S PLENTY OF SOURCES OF
LARGE-SCALE LIFT AVAILABLE...AS THE NORTH COUNTRY WILL BE IN THE
DIFFLUENT/FAVORABLE POLEWARD EXIT REGION OF A 100 KT 300 MB
UPPER- LEVEL JET BETWEEN 03-10Z...AS WELL AS IN THE MIDST OF
CYCLONIC VORTICITY ADVECTION FROM APPROACHING NEGATIVELY TILTED
MID-LEVEL SHORTWAVE TROUGH. A SUBSTANTIAL NORTHWARD SURGE OF LOW-
LEVEL MOISTURE AIDED BY A SOUTHWESTERLY 35-KT LOW-LEVEL JET
RESULTS IN MODEL PW VALUES AREAWIDE BETWEEN 0.75"-1.25" OVERNIGHT
WITH THE HIGHEST VALUES ACROSS SOUTHERN AND EASTERN VERMONT. ALL
THAT BEING SAID...POPS DO INCREASE STEADILY BETWEEN 00Z-03Z WITH
CATEGORICAL RAIN IN THE FORECAST BETWEEN 03-09Z WITH A TAPER DOWN
IN POPS FROM SOUTHWEST TO NORTHEAST THEREAFTER. QPF REMAINS
CONSISTENT WITH PRIOR FORECASTS...RANGING FROM AROUND A THIRD TO
A HALF-INCH WITH THE HEAVIEST AMOUNTS IN SOUTHERN AND EASTERN
VERMONT.
TEMPERATURES ARE ESSENTIALLY A BLEND TOWARD SOME OF THE WARMER
MOS GUIDANCE...GENERALLY IN THE UPPER 40S TO LOW 50S UNDER MOSTLY
OVERCAST SKIES THROUGH THE OVERNIGHT.
&&
.SHORT TERM /7 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 340 PM EDT THURSDAY...STORM SYSTEM DEPARTS FRIDAY
MORNING...WITH ANY LINGERING SHOWERS WINDING DOWN AND SKY
CONDITIONS BEGINNING TO IMPROVE THROUGH THE MORNING HOURS. SOME
LAKE EFFECT MOISTURE ONCE AGAIN GETS ADVECTED OFF OF LAKE ONTARIO
AS THE SYSTEM DEPARTS...AND SO HAVE OPTED FOR MORE CLOUD COVER AS
WELL AS A SLIGHT CHANCE FOR LAKE EFFECT SHOWERS IN THE
ADIRONDACKS AND SOUTHERN SAINT LAWRENCE COUNTY. WITH 850 MB
TEMPERATURES FALLING TO AROUND +3C HIGHS ON FRIDAY TO RANGE FROM
THE MID 50S IN THE ADIRONDACKS TO THE UPPER 50S TO LOW 60S
ELSEWHERE. MOSTLY CLEAR SKIES UNDER WEAK HIGH PRESSURE SHOULD
ALLOW FOR LOWS ON FRIDAY TO DROP TO THE MID 30S IN THE
ADIRONDACKS AND NORTHEAST KINGDOM TO THE MID 40S IN THE WARMER
VALLEYS.
A LARGE LONGWAVE TROUGH ASSOCIATED WITH COLDER CONTINENTAL AIR
WILL ESTABLISH ITSELF ACROSS THE CENTRAL/EAST-CENTRAL CONUS BY
SATURDAY MORNING...WITH BROADLY CYCLONIC MID-LEVEL FLOW
PREVAILING ACROSS THE NORTHEASTERN STATES. GUIDANCE SHOWS A
COUPLE OF POORLY DEFINED SHORTWAVE TROUGHS ROUNDING THE BASE OF
THE LONGWAVE TROUGH APPROACHING THE NORTH COUNTRY ON
SATURDAY...BRINGING AN INCREASE IN CLOUDS AND POPS. POPS INCREASE
TO LIKELY BY SATURDAY NIGHT WITH MOSTLY RAIN EXPECTED. HOWEVER
LOW-LEVEL THERMAL PROFILES WILL BE COOLING TO THE POINT WHERE A
MIX OF RAIN AND SNOW SHOWERS MAY BE POSSIBLE FOR THE HIGHEST
SUMMITS OF THE ADIRONDACKS. RAINFALL AMOUNTS GENERALLY A QUARTER-
INCH OR LESS THROUGH 12Z SUNDAY...AND ANY ACCUMULATION ON SOME OF
THE HIGHER PEAKS OF THE ADIRONDACKS NOT AMOUNTING TO MORE THAN A
LIGHT COATING. HIGHS SATURDAY GENERALLY IN THE UPPER 50S TO LOW
60S WITH LOWS IN THE LOWER 30S TO LOW 40S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 351 PM EDT THURSDAY...LARGE UPPER LEVEL TROF WILL BE
ANCHORED OVER THE GREAT LAKES REGION THROUGH THE ENTIRE EXTENDED
PORTION OF THE FORECAST...SLOWLY MOVING EASTWARD TOWARDS THE END
OF NEXT WEEK. LOCATION OF THIS TROF WILL KEEP THE WEATHER PATTERN
ACTIVE ACROSS THE NORTH COUNTRY WITH SEVERAL CHANCES FOR
PRECIPITATION. THERE ARE STILL SOME MODEL DIFFERENCES AS FAR AS
TIMING OF THESE SHORTWAVES GO...THEREFORE LOW FORECASTER
CONFIDENCE ON TIMING FOR IMPULSES. AT THIS POINT LOOKS LIKE IT
WILL BE COLD ENOUGH AT NIGHT ABOVE ABOUT 2000 FEET FOR SNOW
SHOWERS TO MIX IN. NOT MUCH ACCUMULATION EXPECTED WITH ANY
PARTICULAR SHORTWAVE...THOUGH AFTER A FEW IMPULSES BRINGING LIGHT
SNOW...HIGHER PEAKS COULD BE LEFT WITH A WHITE COATING. MAINLY
RAIN SHOWERS EXPECTED DURING THE DAYTIME HOURS. HIGHEST POPS ARE
MENTIONED ON TUESDAY WITH BEST CHANCE AT SOME PRECIPITATION AND
BEST MODEL AGREEMENT AS WELL. TEMPERATURES WILL START OUT ABOVE
NORMAL THEN TREND BELOW NORMAL AT THE END OF THE PERIOD. MONDAY
NIGHT AND TUESDAY WILL BE THE WARMEST OF THE PERIOD. COLDEST
TEMPERATURES WILL BE TOWARDS THE END OF NEXT WEEK AS UPPER TROF
FINALLY SHIFTS EASTWARD ACROSS OUR FORECAST AREA.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
THROUGH 18Z FRIDAY...VFR CONDITIONS THRU 00Z FRIDAY WITH SCT-BKN
035-080. LOW PRESSURE APPROACHING FROM THE SSW WILL BEGIN TO
SHIFT CONDITIONS TO MVFR/IFR BY 00Z FRI AS RAIN/LOW CLDS BUILD
INTO AREA. LGT RAIN BEGINS AROUND 00Z-02Z AND REMAINS THRU 12Z
FRIDAY AS SYSTEM LIFTS N AND EAST OF AREA. VSBY IN RAIN/FG MAINLY
3-6SM W/ MPV/SLK SHIFTING LWR AT TIMES BY 06Z FRI TO LESS THAN
2SM. CEILINGS WILL RANGE FROM BKN010-030. WINDS SSW 5-10KTS...
TRANSITIONING TO LGT/VAR FROM THE SW TO NE AS RAIN BEGINS. RAIN
WILL BE ENDING FROM WEST TO EAST ACROSS THE AREA FROM 08-11Z.
CEILINGS WILL IMPROVE TO VFR...THOUGH SOME BR MAY REMAIN THROUGH
12Z. WINDS OUT OF THE WSW AGAIN TOMORROW WITH MAINLY BROKEN
CEILINGS.
OUTLOOK 18Z FRIDAY THROUGH TUESDAY...
18Z FRIDAY THROUGH 00Z SATURDAY...VARIETY OF FLIGHT
CATEGORIES...AS LOW AS IFR...IN PERIODS OF RAIN WITH NEXT LOW
PRESSURE SYSTEM.
00Z SATURDAY THROUGH 00Z SUNDAY...MAINLY VFR UNDER HIGH PRESSURE.
00Z SUNDAY THROUGH TUESDAY...MVFR RAIN SHOWERS POSSIBLE AS
ADDITIONAL SYSTEMS MOVE THROUGH THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...LOCONTO
NEAR TERM...LOCONTO
SHORT TERM...LOCONTO
LONG TERM...NEILES
AVIATION...NEILES
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
340 PM EDT THU OCT 17 2013
.SYNOPSIS...
WEAK HIGH PRESSURE AREA DEPARTS EARLY THIS EVENING AS A FRONTAL
SYSTEM MOVES ACROSS THE NORTH COUNTRY FROM THE SOUTHWEST TONIGHT.
CONDITIONS GRADUALLY IMPROVE FRIDAY MORNING AS ANOTHER AREA OF
WEAK HIGH PRESSURE BUILDS BACK IN. UNSETTLED WEATHER RETURNS ON
SATURDAY AND SATURDAY NIGHT WITH A TURN TOWARD SEASONABLY COOLER
WEATHER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM FRIDAY MORNING/...
AS OF 340 PM EDT THURSDAY...PARTLY CLOUDY SKIES CONTINUE IN MANY
AREAS ACROSS THE NORTH COUNTRY LATE THIS AFTERNOON...THOUGH SOME
LINGERING LAKE EFFECT MOISTURE RESULTING IN MOSTLY OVERCAST SKIES
IN THE ADIRONDACKS. HOWEVER...CHANGEABLE WEATHER CONDITIONS
EXPECTED LATE AFTERNOON INTO THE EVENING AS VISIBLE SATELLITE
REVEALS A BROAD SHIELD OF CLOUDINESS QUICKLY SPREADING
NORTHEASTWARD FROM THE OHIO VALLEY AND THE CENTRAL/LOWER
APPALACHIANS. WATER VAPOR AND RUC ANALYSES REVEAL A RATHER POTENT
MID-LEVEL SHORTWAVE TROUGH MOVING NORTHEASTWARD FROM THE LOWER
OHIO VALLEY...WITH A WEAK SFC CYCLONE EVIDENT IN LATE AFTERNOON
SFC ANALYSIS CENTERED NEAR SOUTHERN WEST VIRGINIA. LOOK FOR A
MARKED INCREASE IN CLOUD COVER AREAWIDE EARLY THIS EVENING AS BOTH
THE MID-LEVEL TROUGH AND ASSOCIATED SFC CYCLONE PUSH
NORTHEASTWARD.
GUIDANCE REMAINS IN PRETTY GOOD AGREEMENT REGARDING TIMING AND QPF
WITH THIS APPROACHING SYSTEM. THERE`S PLENTY OF SOURCES OF
LARGE-SCALE LIFT AVAILABLE...AS THE NORTH COUNTRY WILL BE IN THE
DIFFLUENT/FAVORABLE POLEWARD EXIT REGION OF A 100 KT 300 MB
UPPER-LEVEL JET BETWEEN 03-10Z...AS WELL AS IN THE MIDST OF CYCLONIC
VORTICITY ADVECTION FROM APPROACHING NEGATIVELY TILTED MID-LEVEL
SHORTWAVE TROUGH. A SUBSTANTIAL NORTHWARD SURGE OF LOW-LEVEL
MOISTURE AIDED BY A SOUTHWESTERLY 35-KT LOW-LEVEL JET RESULTS IN
MODEL PW VALUES AREAWIDE BETWEEN 0.75"-1.25" OVERNIGHT WITH THE
HIGHEST VALUES ACROSS SOUTHERN AND EASTERN VERMONT. ALL THAT BEING
SAID...POPS DO INCREASE STEADILY BETWEEN 00Z-03Z WITH CATEGORICAL
RAIN IN THE FORECAST BETWEEN 03-09Z WITH A TAPER DOWN IN POPS FROM
SOUTHWEST TO NORTHEAST THEREAFTER. QPF REMAINS CONSISTENT WITH
PRIOR FORECASTS...RANGING FROM AROUND A THIRD TO A HALF-INCH WITH
THE HEAVIEST AMOUNTS IN SOUTHERN AND EASTERN VERMONT.
TEMPERATURES ARE ESSENTIALLY A BLEND TOWARD SOME OF THE WARMER MOS
GUIDANCE...GENERALLY IN THE UPPER 40S TO LOW 50S UNDER MOSTLY
OVERCAST SKIES THROUGH THE OVERNIGHT.
&&
.SHORT TERM /7 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 340 PM EDT THURSDAY...STORM SYSTEM DEPARTS FRIDAY
MORNING...WITH ANY LINGERING SHOWERS WINDING DOWN AND SKY
CONDITIONS BEGINNING TO IMPROVE THROUGH THE MORNING HOURS. SOME
LAKE EFFECT MOISTURE ONCE AGAIN GETS ADVECTED OFF OF LAKE ONTARIO
AS THE SYSTEM DEPARTS...AND SO HAVE OPTED FOR MORE CLOUD COVER AS
WELL AS A SLIGHT CHANCE FOR LAKE EFFECT SHOWERS IN THE ADIRONDACKS
AND SOUTHERN SAINT LAWRENCE COUNTY. WITH 850 MB TEMPERATURES
FALLING TO AROUND +3C HIGHS ON FRIDAY TO RANGE FROM THE MID 50S IN
THE ADIRONDACKS TO THE UPPER 50S TO LOW 60S ELSEWHERE. MOSTLY
CLEAR SKIES UNDER WEAK HIGH PRESSURE SHOULD ALLOW FOR LOWS ON
FRIDAY TO DROP TO THE MID 30S IN THE ADIRONDACKS AND NORTHEAST
KINGDOM TO THE MID 40S IN THE WARMER VALLEYS.
A LARGE LONGWAVE TROUGH ASSOCIATED WITH COLDER CONTINENTAL AIR WILL
ESTABLISH ITSELF ACROSS THE CENTRAL/EAST-CENTRAL CONUS BY SATURDAY
MORNING...WITH BROADLY CYCLONIC MID-LEVEL FLOW PREVAILING ACROSS
THE NORTHEASTERN STATES. GUIDANCE SHOWS A COUPLE OF POORLY DEFINED
SHORTWAVE TROUGHS ROUNDING THE BASE OF THE LONGWAVE TROUGH
APPROACHING THE NORTH COUNTRY ON SATURDAY...BRINGING AN INCREASE IN
CLOUDS AND POPS. POPS INCREASE TO LIKELY BY SATURDAY NIGHT WITH
MOSTLY RAIN EXPECTED. HOWEVER LOW-LEVEL THERMAL PROFILES WILL BE
COOLING TO THE POINT WHERE A MIX OF RAIN AND SNOW SHOWERS MAY BE
POSSIBLE FOR THE HIGHEST SUMMITS OF THE ADIRONDACKS. RAINFALL
AMOUNTS GENERALLY A QUARTER-INCH OR LESS THROUGH 12Z SUNDAY...AND
ANY ACCUMULATION ON SOME OF THE HIGHER PEAKS OF THE ADIRONDACKS
NOT AMOUNTING TO MORE THAN A LIGHT COATING. HIGHS SATURDAY GENERALLY
IN THE UPPER 50S TO LOW 60S WITH LOWS IN THE LOWER 30S TO LOW
40S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 426 AM EDT THURSDAY...FOR THE EXTENDED PERIOD SATURDAY
NIGHT ON INTO NEXT WEDNESDAY...SYNOPTIC SETUP FOR THE NORTH
COUNTRY REMAINS THE SAME AS OVER THE PAST SEVERAL MDL RUNS. BROAD
UPPER LOW WILL SET UP OVER THE CENTRAL PLAINS OVER THE UPCOMING
WEEKEND AND SHIFT EAST SLOWLY THRU WEDNESDAY. DURING THIS
TIME...SEVERAL SHORTWAVES WILL WORK AROUND THE BASE OF THE TROUGH
AND SWING THRU THE CWA. THERE CONTINUE TO BE MDL DIFFERENCES AS
TO TIMING OF EACH SHORTWAVE THRU THE AREA...ESPECIALLY FOR THE
LATTER HALF OF THE EXTENDED WHEN THE TROUGH STARTS ITS SHIFT
EASTWARD INTO QUEBEC. BULK OF PRECIP INITIALLY WITH EACH SYSTEM
WILL START OVER N NY BFR SHIFTING EAST THRU THE CWA AND EXITING.
HAVE ADJUSTED HIR POPS FOR THESE AREAS FOR FIRST PORTION OF THE
EXTENDED...TAPERING DOWN TO CHANCE/SL CHANCE FOR PRECIP FOR THE
ENTIRE AREA AS MDL UNCERTAINTY INCREASE ON TRACK OF SYSTEM AS
WELL AS TIMING ARRIVAL. CAA WILL WORK INTO AREA ON BACKSIDE OF
EACH EXITING SYSTEM...ALLOWING FOR HIR ELEV(ABV 2000FT) TO SEE
CHANGE TO LIGHT -SW FOR MUCH OF THE OVERNGT PERIOD. OVERALL...HIR
SPOTS COULD SEE A LIGHT COATING OF SNOW WHEN ALL SAID AND DONE.
EXPECTING -RW DURING THE DAY. HIGHS GENERALLY IN THE 50S TAPERING
TO 40S BY WEDNESDAY. OVERNGT LOWS IN THE 30S TO NEAR 40F IN CVLY.
COLDEST TEMPS IN DACKS AND NE VT.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
THROUGH 18Z FRIDAY...VFR CONDITIONS THRU 00Z FRIDAY WITH SCT-BKN
035-080. LOW PRESSURE APPROACHING FROM THE SSW WILL BEGIN TO
SHIFT CONDITIONS TO MVFR/IFR BY 00Z FRI AS RAIN/LOW CLDS BUILD
INTO AREA. LGT RAIN BEGINS AROUND 00Z-02Z AND REMAINS THRU 12Z
FRIDAY AS SYSTEM LIFTS N AND EAST OF AREA. VSBY IN RAIN/FG MAINLY
3-6SM W/ MPV/SLK SHIFTING LWR AT TIMES BY 06Z FRI TO LESS THAN
2SM. CEILINGS WILL RANGE FROM BKN010-030. WINDS SSW 5-10KTS...
TRANSITIONING TO LGT/VAR FROM THE SW TO NE AS RAIN BEGINS. RAIN
WILL BE ENDING FROM WEST TO EAST ACROSS THE AREA FROM 08-11Z.
CEILINGS WILL IMPROVE TO VFR...THOUGH SOME BR MAY REMAIN THROUGH
12Z. WINDS OUT OF THE WSW AGAIN TOMORROW WITH MAINLY BROKEN
CEILINGS.
OUTLOOK 18Z FRIDAY THROUGH TUESDAY...
18Z FRIDAY THROUGH 00Z SATURDAY...VARIETY OF FLIGHT
CATEGORIES...AS LOW AS IFR...IN PERIODS OF RAIN WITH NEXT LOW
PRESSURE SYSTEM.
00Z SATURDAY THROUGH 00Z SUNDAY...MAINLY VFR UNDER HIGH PRESSURE.
00Z SUNDAY THROUGH TUESDAY...MVFR RAIN SHOWERS POSSIBLE AS
ADDITIONAL SYSTEMS MOVE THROUGH THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...LOCONTO
NEAR TERM...LOCONTO
SHORT TERM...LOCONTO
LONG TERM...JN
AVIATION...JN/NEILES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
915 PM EDT FRI OCT 18 2013
.SYNOPSIS...
A WAVE OF LOW PRESSURE WILL DEVELOP ALONG THE COASTAL FRONT TONIGHT
AND WILL TRACK NORTHEAST OFF THE MID-ATLANTIC COAST ON SATURDAY. A
STRONGER SECONDARY COLD FRONT WILL CROSS THE REGION SATURDAY
EVENING.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 915 PM FRIDAY...
MAIN FORECAST CHALLENGE TONIGHT INTO SATURDAY IS HOW FAR WEST-NW
WILL THE THREAT FOR PATCHY LIGHT RAIN EXPAND ACROSS CENTRAL NC.
A SURFACE BOUNDARY REMAINS STALLED ACROSS THE IMMEDIATE SC COAST AMD
JUST OFFSHORE OF SE NC. A WEAK SFC LOW WAS NOTED IN THE SFC WIND
FIELD IN VICINITY OF MYRTLE BEACH. A WEAK SFC RIDGE DID EXTEND SW-NE
ACROSS THE PIEDMONT OF CENTRAL NC. THIS RIDGE IS VERY SHALLOW AS
AREAS VAD WIND PROFILES DEPICT A LIGHT NE WIND CONFINED TO THE
LOWEST 1-2K FT WITH SLY FLOW ALOFT. SFC DEWPOINTS UNDERNEATH THIS
RIDGE WERE IN THE LOW-MID 50S. MEANWHILE DEWPOINTS CLOSER TO
BOUNDARY WERE IN THE 60S.
WATER VAPOR IMAGERY DEPICTS A JETLET LIFTING NE ACROSS THE LOWER MS
VALLEY THIS EVENING ALONG WITH A MINOR MID LEVEL DISTURBANCE LIFTING
NE ACROSS SE LA AND SOUTHERN MS.
THE APPROACH OF THE MID LEVEL DISTURBANCE WILL MAINTAIN AND POSSIBLY
BACK THE FLOW IN THE 925-850MB LAYER OVERNIGHT INTO EARLY SATURDAY.
WHILE THE SLY FLOW IS NOT OVERLY STRONG...THE NEAR TERM MODEL
GUIDANCE DOES SUGGEST ENOUGH UPGLIDE TO CAUSE PATCHY LIGHT RAIN OVER
SECTIONS OF THE SANDHILLS AND THE COASTAL PLAIN. MOST MODEL GUIDANCE
SUGGEST MEASURABLE RAIN A POSSIBILITY AS FAR WEST AS SILER CITY AND
BURLINGTON. THE GFS MODEL VERIFIED FAIRLY WELL AT 00Z IN ITS PRECIP
DEPICTION FIELD WHILE THE 12Z ECMWF ALONG WITH A BULK OF THE CAM
MODELS WERE TOO AGGRESSIVE. LATEST RAP MODEL (23Z) DELAYS EXPANSION
UNTIL 07Z (SEEMS REASONABLE CONSIDERING THE MID LEVEL PERTURBATION
IS WELL SW OF OUR REGION AT 00Z) WITH MEASURABLE RAINFALL AS FAR
WEST AS THE NORTHERN MOUNTAINS AND FOOTHILLS SHORTLY AFTER 12Z
SATURDAY. AT THIS TIME...THIS SEEMS TOO AGGRESSIVE CONSIDERING THE
AMOUNT OF DRY AIR NOW RESIDING OVER THE WESTERN PIEDMONT (PER 00Z
GSO SOUNDING) AND WEAK TO NON-EXISTENT 850MB MOISTURE TRANSPORT
INTO THE PIEDMONT. PLAN TO MAINTAIN HIGHEST THREAT FOR MEASURABLE
RAIN EAST OF HIGHWAY 1...AND MOSTLY OVER THE COASTAL PLAIN.
MIN TEMPS WILL DEPEND UPON THE AREAL EXTENT OF RAIN (SE HALF) AND
THICKNESS OF CLOUD COVER (NW HALF). OVER THE NW HALF...PARTLY
CLOUDY SKIES HAVE ALLOWED TEMPS TO COOL INTO THE MID-UPPER 50S AT
MID EVENING. AS CLOUDS INCREASE/THICKEN...SHOULD SEE TEMPS STABILIZE
AND MAY ACTUALLY RISE A DEGREE OR TWO AFTER MIDNIGHT. OVER THE
EAST-SE...TEMPS WILL HOLD STEADY OR SHOW A VERY SLOW DECLINE THROUGH
THE NIGHT.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
AS OF 245 PM FRIDAY...
PRECIP SHOULD BE COMING TO AN END SATURDAY MORNING AS A WEAK WAVE OF
LOW PRESSURE MOVES ACROSS THE COASTAL PLAIN AND OFF TO THE
NORTHEAST. FORECAST SOUNDINGS SHOW A DEEP SOUTHWESTERLY FLOW AND
RAPID DRYING IN THE MID LEVELS AHEAD OF THE SHORTWAVE SWINGING
THROUGH THE MIDWEST...BUT IF WE GET SUFFICIENT RAIN OVERNIGHT...LOW
CLOUDS MAY BE SLOWER TO SCOUR THAT MODELS PROJECT. ONCE CLOUDS DO
BREAK...LOWER 70S SHOULD BE ATTAINABLE.
A COLD FRONT WILL MOVE INTO WESTERN NC SATURDAY AFTERNOON AND CROSS
CENTRAL NC SATURDAY EVENING. THE MAIN HEIGHT FALLS AND DPVA
ASSOCIATED WITH THE SHORTWAVE WILL PASS TO OUR NORTH...AND WITH
MID-LEVEL DYING AHEAD OF THE FRONT...THERE WILL BE LIMITED
FORCING/MOISTURE TO PRODUCE ANY PRECIP ALONG THE FRONT. ONLY THE
ECMWF SHOWS MUCH QPF ALONG THE FRONT...AND THIS APPEARS OVERDONE.
WILL MAINTAIN JUST A SLIGHT CHANCE DURING THE AFTERNOON. COLD
ADVECTION WILL KICK IN SATURDAY NIGHT AND LOWS SHOULD DROP INTO THE
MID TO UPPER 40S FOR MUCH OF THE AREA.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 230 PM FRIDAY...
THE UPPER TROF OVER THE CENTRAL CONUS WILL BE IN PERSISTENT RELOAD
MODE THROUGH THE EXTENDED PERIOD...RESULTING IN UNSEASONABLY COOL
AND DRY WEATHER SETTLING...THEN DEEPENING OVER AREA NEXT WEEK.
WE WILL BE LOOKING AT MOSTLY CLEAR SKIES SUNDAY AND MONDAY AS HIGH
PRESSURE OVER THE AREA IS GRADUALLY SQUEEZED OFF TO THE NORTHEAST.
HIGHS WILL BE IN THE MID 60S NORTHWEST TO LOWER 70S SOUTHEAST BOTH
DAYS. AS THE HIGH MOVES OFF TO THE NORTHEAST...A FRONT WHICH HAS
BEEN LOOMING OFFSHORE SOUTH AND EAST OF THE AREA WILL MAKE A BRIEF
NORTHERLY AND WESTERLY SURGE. THE BROAD MOISTURE PLUME OF SOUTHERN
STREAM MOISTURE ASSOCIATED WITH THIS FRONT WILL SETTLE OVER THE
COASTAL PLAIN...PRODUCING A CHANCE OF SHOWERS IN THE EASTERN CWFA
LATER MONDAY NIGHT AND TUESDAY. THIS MOISTURE WILL BE SHUNTED
OFFSHORE BY A COLD FRONT LATE TUESDAY...WHICH WILL THEN USHER IN A
DEEPENING POLAR AIRMASS THROUGH THE END OF THE WEEK. HIGHS WEDNESDAY
WILL BE MAINLY IN THE MID 60S...WITH HIGHS BOTH THURSDAY AND FRIDAY
MOSTLY IN THE 60 TO 65 RANGES...BUT STRUGGLING TO REACH 60 IN THE
NORTHWEST. WE WILL SEE THE COLDEST TEMPS OF THE SEASON TO DATE AS
THE POLAR AIRMASS RADIATIONALLY COOLS OVERNIGHT...WITH MINS IN THE
40S SUNDAY THROUGH TUESDAY IN THE 40S...FALLING TO THE MID AND UPPER
30S WEDNESDAY AND THURSDAY NIGHTS.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 830 PM FRIDAY...
24-HR TAF PERIOD:
A WEAK AREA OF LOW PRESSURE WILL LIFT NORTH-NORTHEASTWARD ALONG THE
STALLED FRONT ALONG COASTAL PORTIONS OF THE CAROLINAS TONIGHT. THIS
WILL AGAIN INCREASE THE POTENTIAL FOR SOME RAIN AT THE EASTERN TAF
SITES DURING THE OVERNIGHT HOURS... ALONG WITH SPREADING SUB-VFR
CIGS ACROSS THE AREA... WITH THE LOWEST CIGS EXPECTED AT KFAY AND
KRWI... WHERE COVERAGE AND AMOUNTS OF THE RAIN WILL BE THE GREATEST.
CIGS ARE ALREADY/VERY NEAR THE MVFR RANGE AT THE EASTERN TAF SITES
THIS EVENING (WITH KFAY HAVING BEEN IN THE MVFR CATEGORY ALL DAY).
FURTHER WEST... EXPECTED CIGS WILL BE A BIT SLOWER TO DROP INTO THE
MVFR RANGE... WITH THE BEST LOW LEVEL MOISTURE EXPECTED TO BE ACROSS
THE EAST TONIGHT (SUB-VFR CIGS EXPECTED CLOSER TO MIDNIGHT OR AFTER
AT KGSO/KINT). THUS... EXPECT WE WILL SEE CIGS RANGE FROM IFR/LIFR
AT KFAY/KRWI TO GENERALLY MVFR FOR KGSO/KINT. HOWEVER... AS THE
AFOREMENTIONED SURFACE LOW LIFTS OFF TO THE NORTHEAST ON SATURDAY
MORNING... CIGS WILL FIRST IMPROVE ACROSS THE EASTERN TAF SITES...
THEN LAST AT KGSO/KINT. HAVE WENT A BIT MORE PESSIMISTIC WITH REGARD
TO HOW QUICKLY CIGS WILL LIFT TO VFR THOUGH... WITH THE NEXT SURFACE
COLD FRONT NOT EXPECTED TO CROSS THE AREA UNTIL SATURDAY EVENING.
THINK WE WILL SEE SOUTHWESTERLY SURFACE WINDS AND LIFTING CIGS
DEVELOP FIRST ACROSS THE SOUTHEAST/EAST... THEN LAST AT KGSO/KINT.
IN FACT THE NAM BUFR SOUNDING SHOW THE LINGERING MVFR CIGS NOT
LIFTING UNTIL LATE SATURDAY AFTERNOON... JUST BEFORE THE NEXT COLD
FRONTAL PASSAGE. FOR NOW THOUGH WILL SHOW VFR CIGS RETURNING
EVERYWHERE BY 20Z.
LOOKING AHEAD:
VFR CONDITIONS CONDITIONS SHOULD RETURN SATURDAY EVENING/NIGHT/ WITH
THE PASSAGE OF A DRY COLD FRONT. DRY HIGH PRESSURE WILL RULE SUNDAY
AND INTO EARLY NEXT WEEK... BEFORE ANOTHER SYSTEM APPROACHES/AFFECTS
THE AREA FROM THE SOUTHWEST AND WEST ON MONDAY NIGHT THROUGH MIDWEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...WSS
SHORT TERM...SMITH
LONG TERM...MLM
AVIATION...BSD/SMITH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
903 PM CDT FRI OCT 18 2013
.UPDATE...
ISSUED AT 903 PM CDT FRI OCT 18 2013
THE LATEST HRRR AND RAP13 PRECIPITATION FIELDS OVERALL FIT THE
CURRENT RADAR IMAGERY THIS EVENING. SHORTWAVE NOW INTO FAR NORTH
CENTRAL NORTH DAKOTA PER LATEST WATER VAPOR LOOP IN COMBINATION
WITH THE LEFT EXIT REGION OF A 100KT H3 JET STREAK CONTINUES TO
PROVIDE THE VERTICAL MOTION FOR PRODUCING SCATTERED SHOWERS. THIS
WILL GRADUALLY SHIFT FURTHER SOUTH AND EAST OVERNIGHT...WITH THE
PRECIPITATION EXITING THE JAMES RIVER VALLEY BY AROUND 09Z
SATURDAY. ATTENTION THEN TURNS TO THE NORTHWEST WHERE WARM AIR
ADVECTION ASSOCIATED WITH A WARM FRONTAL BOUNDARY BEGINS TO
IMPINGE FROM SOUTHERN CANADA INTO NORTHWEST AND NORTH CENTRAL
NORTH DAKOTA. ISENTROPIC LIFT PER 00Z NAM WILL LIKELY LEAD TO
ISOLATED RAIN OR SNOW SHOWERS BETWEEN 12Z AND 18Z SATURDAY IN THE
ABOVE MENTIONED AREA. THE CURRENT FORECAST HAS THIS FORECAST
ALREADY IN PLACE.
UPDATE ISSUED AT 524 PM CDT FRI OCT 18 2013
LATEST WATER VAPOR SHOWS A SHORTWAVE ALONG THE SOUTHERN SASKATCHEWAN
AND MANITOBA BORDER DIVING SOUTH WITH TIME. AN AREA OF VERTICAL
MOTION/H85-H3 OMEGA AHEAD OF THIS WAVE CONTINUES TO RESULT IN
SURFACE PRESSURE FALLS AND SCATTERED RAINSHOWERS IN NORTH CENTRAL
NORTH DAKOTA. THE LATEST HRRR FORECASTS THIS AREA TO SHIFT SOUTH
AND INCREASE IN AREAL COVERAGE FOR SOUTH CENTRAL NORTH DAKOTA
THROUGH 04Z. CONCUR WITH THIS IDEA PER LATEST RADAR RETURNS. THERE
COULD BE SOME SNOW OR GRAUPEL WITHIN HEAVIER CONVECTIVE SHOWERS
THIS EVENING AS THE SHALLOW SURFACE WARM LAYER COOLS WITH SUPERCOOLED
WATER DROPLETS DOMINATING ABOVE. MAIN FORECAST REMAINS ON TRACK
WITH MINOR UPDATES TO HOURLY GRIDDED DATA.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 251 PM CDT FRI OCT 18 2013
SMALL POCKETS OF LIGHT RAIN WILL CONTINUE TO DEVELOP AND PUSH
SOUTHEAST THROUGH THE AFTERNOON HOURS. THE HIGHEST PRECIPITATION
COVERAGE IS EXPECTED NORTHEAST OF A LINE FROM KENMARE TO BISMARCK AND
ELLENDALE. AS NEAR SURFACE TEMPS DROP OFF TONIGHT...EXPECT RAIN TO
BECOME MIXED WITH OR CHANGE OVER TO ALL SNOW. THERE MAY BE SOME
VERY MINOR ACCUMULATIONS ON GRASSY SURFACES...MAINLY FROM
BOTTINEAU...TO CARRINGTON AND JAMESTOWN.
ON SATURDAY...A WARM FRONT WILL PUSH INTO WESTERN NORTH DAKOTA
DURING THE MORNING HOURS. A BAROCLINIC ZONE NEAR THE BOUNDARY MAY
BE ENOUGH TO SUPPORT A FEW LIGHT SNOW SHOWERS...MAINLY DURING THE
MORNING HOURS. AGAIN...LITTLE OR NO ACCUMULATION IS EXPECTED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 251 PM CDT FRI OCT 18 2013
THE LONG TERM FORECAST WILL BE DOMINATED BY NORTH/NORTHWEST FLOW
ALOFT WITH A TROUGH OVER EASTERN CANADA/US AND A WESTERN RIDGE OVER
WESTERN CANADA/US.
THE MAIN FOCUS IN THE LONG TERM WILL BE SNOW AMOUNTS IN THE
NORTHEAST PART OF THE FORECAST AREA...BOTTINEAU-ROLLA-RUGBY-HARVEY
LATE SATURDAY NIGHT INTO SUNDAY MORNING. OTHER THAN THAT THERE WILL
BE A CHANCE OF LIGHT PRECIPITATION MONDAY/MONDAY NIGHT.
REGARDING THIS SATURDAY NIGHT/SUNDAY CLIPPER EVENT...TODAY`S MODELS
ARE INDICATING WARM AIR ADVECTION AHEAD OF THE SURFACE CLIPPER -
ENOUGH SUCH THAT PRECIPITATION SATURDAY EVENING AND INTO VERY EARLY
SUNDAY MORNING WOULD BE AHEAD AND EAST OF THE SURFACE LOW AND IN THE
FORM OF RAIN. RAIN WOULD NOT BE CHANGING TO SNOW UNTIL ROUGHLY 3 AM
IN THE TURTLE MOUNTAINS...THOUGH FARTHER WEST THE CHANGE TO SNOW MAY
OCCUR AROUND MIDNIGHT SATURDAY NIGHT. A GOOD AMOUNT OF THE
PRECIPITATION ASSOCIATED WITH THIS SYSTEM IS PROGGED TO BEGIN LATE
AFTERNOON/EARLY EVENING...WITH THE BEST LIFT AND MORE INTENSE
PRECIPITATION OCCURRING BEFORE MIDNIGHT. THE SURFACE LOW IS PROGGED
TO MOVE SOUTH FROM SASKATCHEWAN AND CROSS THE NORTH DAKOTA BORDER
BETWEEN 10 PM AND MIDNIGHT. THUS THE BULK OF THE ASSOCIATED
PRECIPITATION SHOULD BE IN THE FORM OF RAIN.
REGARDING SNOW AMOUNTS...THE LATEST EXPECTATION IS THAT THE TURTLE
MOUNTAINS MAY RECEIVE UP TO 2 INCHES OF SNOW FROM SATURDAY NIGHT
THROUGH SUNDAY...WITH HALF AN INCH TO AN INCH IN THE SURROUNDING
AREAS FROM BOTTINEAU TO NORTHERN MCHENRY TO PIERCE COUNTIES. LESSER
AMOUNTS EXPECTED ACROSS NORTHWESTERN NORTH DAKOTA TO THE NORTHERN
JAMES RIVER VALLEY.
WINDY AS WELL SATURDAY NIGHT AND SUNDAY AS THE CLIPPER LOW MOVES
FROM THE NORTH CENTRAL TO SOUTHEASTERN NORTH DAKOTA. NORTHWEST WINDS
OF 20 TO 30 MPH EARLY SUNDAY MORNING IN THE WEST...AND DAYTIME
SUNDAY OVER WESTERN AND CENTRAL NORTH DAKOTA.
A NEXT WEAKER WAVE IS THROUGH ON MONDAY / TUESDAY...FOLLOWED BY THE
BUILDING H5 RIDGE WITH DRIER AND MORE SEASONAL TEMPERATURES. THE
REST OF THE LONG TERM WILL SEE HIGHS IN THE 30S AND 40S OVER CENTRAL
NORTH DAKOTA...AND 40S TO LOWER 50S OVER WESTERN NORTH DAKOTA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 524 PM CDT FRI OCT 18 2013
LOW VFR TO MVFR CIGS NEXT 24HR AS ISOLATED TO SCATTERED RAIN AND
SNOW SHOWERS MOVE FROM NORTH TO SOUTH. FOR THURSDAY EVENING...IT
APPEARS KBIS/KJMS WILL HAVE THE HIGHEST PROBABILITY FOR SHOWERS
WITH A VCSH IN THE REST OF THE TERMINALS. CIGS WILL LIFT TO VFR
SATURDAY AFTERNOON AS A WARM FRONT MOVES THROUGH CENTRAL NORTH
DAKOTA.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...RP KINNEY
LONG TERM...JV
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1259 AM CDT THU OCT 17 2013
.UPDATE...
ISSUED AT 1259 AM CDT THU OCT 17 2013
NO SIGNIFICANT CHANGES WITH THIS UPDATE AS THE INHERITED FORECAST
IS ON TRACK AND BLENDED TO THE 05-06 UTC OBSERVED TRENDS. AS OF
06 UTC...A BAND OF LIGHT PRECIPITATION WAS OBSERVED FROM MINOT
SOUTHWEST THROUGH DICKINSON AND BAKER. PRECIPITATION WAS ALL IN
THE FORM OF RAIN...EXCEPT ACROSS FAR SOUTHWEST NORTH DAKOTA AND
INTO MONTANA WITH SNOW BEING REPORTED AT BAKER. GIVEN A SURFACE
BASED WARM LAYER...WILL FOLLOW STANDARD THRESHOLDS OF 37 F FOR ALL
RAIN...34 F FOR ALL SNOW AND A MIX IN BETWEEN FOR PRECIPITATION
TYPE THE REMAINDER OF THE NIGHT.
UPDATE ISSUED AT 859 PM CDT WED OCT 16 2013
WATER VAPOR/IR SATELLITE IMAGERY INDICATIVE OF A BAROCLINIC
LEAF/CYCLOGENESIS CONTINUING IN EASTERN MONTANA...ALTHOUGH
INDICATIONS OF AN OVERALL WEAKENING MAY BE UNDERWAY AS PREVIOUS
COOLING CLOUD TOPS ARE NOW BEGINNING TO WARM. LOCAL/REGIONAL
RADAR IN COMBINATION WITH SURFACE OBSERVATIONS SHOW RAIN AND BRISK
NORTHWEST WINDS IN CENTRAL AND EASTERN MONTANA. SURFACE COLD FRONT
NOW SLICING THROUGH HETTINGER TO SAINT ANTHONY AND JUST NORTH OF
JAMESTOWN. SHORTWAVE TROUGH NOW INTO EASTERN MONTANA WITH A
DIVERGENCE FIELD ENTERING WESTERN NORTH DAKOTA VIA THE RIGHT
ENTRANCE REGION OF AN H3 80KT JET STREAK. THIS WILL TRANSLATE EAST
OVERNIGHT WITH SHOWERS INCREASING IN AREAL COVERAGE AS THE UPPER
SHORTWAVE INTERACTS WITH THE SURFACE COLD FRONT. BUFKIT SOUNDINGS
INDICATE THE WARM LAYER DEPTH IS FORECAST TO REMAIN GREATER THAN
1000FT OFF THE SURFACE...SO EXPECTING MOSTLY RAIN WITH THE
POSSIBILITY OF A RAIN/SNOW MIX TOWARD THE TAIL END OF THE EVENT
LATER TONIGHT IN THE SOUTHWEST. HAVE CONTINUED WITH THE HRRR AND
RAP AS THE PRIMARY MODELS FOR FORECASTING PRECIPITATION THROUGH
THURSDAY MORNING. THE PREVIOUS FORECAST HAS THE ABOVE IDEAS
HANDLED WELL...WITH MINOR ADJUSTMENTS TO HOURLY/SENSIBLE WEATHER
ELEMENTS.
UPDATE ISSUED AT 551 PM CDT WED OCT 16 2013
LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH ALOFT WORKING
THROUGH SOUTHWESTERN SASKATCHEWAN AND INTO CENTRAL MONTANA. LOCAL
AND REGIONAL RADAR SHOWS AN AREA OF RAIN SHOWERS OVER MUCH OF
NORTHEAST MONTANA...AND JUST GRAZING NORTHWEST NORTH DAKOTA. A
SURFACE COLD FRONT STRETCHED FROM NEAR BEACH TO DICKINSON...TO
MCCLUSKY AND INTO HARVEY. THE COLD FRONT CONTINUES TO SAG SOUTH
WITH TIME. THE LATEST HIGH RESOLUTION RAPID REFRESH MODEL CONTINUES
TO HAVE A GOOD HANDLE ON THE ABOVE AREAL OF PRECIPITATION. FOR THIS
UPDATE...HAVE SLOWED UP THE PRECIPITATION AREA BY AN HOUR OR TWO
AND CHANGED THE WORDING FROM UNCERTAINTY TO AREAL COVERAGE. SHOWERS
WILL SHIFT FROM MONTANA INTO WESTERN AND CENTRAL NORTH DAKOTA
OVERNIGHT AS THE UPPER TROUGH/OMEGA FIELD MOVES ACROSS. THE
CURRENT FORECAST HAS THIS SCENARIO HANDLED WELL.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 318 PM CDT WED OCT 16 2013
COLD FRONT PUSHING THROUGH NORTH DAKOTA THIS AFTERNOON WITH POST
FRONTAL PRECIPITATION MOVING SOUTHEAST ACROSS SOUTHERN SASKATCHEWAN
AND NORTHEAST MONTANA. SHORT TERM MODELS REMAIN IN GOOD AGREEMENT
AND WILL UTILIZE A MODEL BLEND WITH PERSISTENCE FOR MOST FORECAST
ELEMENTS. DID USE THE SLIGHTLY WARMER RAW GUIDANCE FOR MINIMUM
TEMPERATURES WITH MAINLY CLOUDY SKIES AND BREEZIER CONDITIONS.
WITH THE WARMER TEMPERATURES...FROZEN PRECIPITATION WAS LIMITED TO
THE HIGHER ELEVATIONS OF THE FAR SOUTHWEST LATE THIS EVENING AND
OVERNIGHT. LITTLE IF ANY ACCUMULATIONS ARE EXPECTED. SYSTEM EXITS
THE SOUTHEAST ON THURSDAY WITH SUBSIDENCE DRYING THINGS OUT FROM
NORTH TO SOUTH DIRECTLY BEHIND THE POST FRONTAL PRECIPITATION
BAND. MOISTURE INCREASES AGAIN THROUGH THE AFTERNOON AND WITH
STEEP LAPSE RATES...WE COULD SEE A FEW RAIN OR SNOW SHOWERS. AT
THIS TIME KEPT ANY PRECIPITATION MENTION CONFINED TO THE NORTHWEST
AND FAR SOUTHWEST...CLOSEST TO THE DEEPEST MOISTURE ALOFT. QUITE A
BIT COOLER ON THURSDAY WITH HIGHS MAINLY IN THE 40S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 318 PM CDT WED OCT 16 2013
THE LONG TERM PERIOD BEGINS WITH A LONGWAVE TROUGH EXTENDING FROM
NORTH CENTRAL CANADA AND HUDSON BAY...THROUGH THE DAKOTAS. A
SECONDARY COLD FRONT IS PROGGED TO MOVE SOUTHEASTWARD ACROSS NORTH
DAKOTA THURSDAY NIGHT...WITH COLD ADVECTION CONTINUING ON FRIDAY
WITH NORTHWESTERLY WINDS LINKED FROM THE SURFACE TO ABOVE H800.
EXPECTING NORTHWEST WINDS TO INCREASE FRIDAY TO 15 TO 25 MPH OVER
EASTERN PORTIONS OF CENTRAL NORTH DAKOTA...TO 25 TO 35 MPH NORTHWEST
WINDS OVER THE WESTERN PART OF THE STATE. A H250 NORTHERLY UPPER
LEVEL JET OF AROUND 100 KNOTS IS PROGGED OVER WESTERN NORTH
DAKOTA...AND THE HIGHER ELEVATIONS OF THE SOUTHWEST WILL LIKELY SEE
THE HIGHER END OF THE 25 TO 35 MPH RANGES.
UPPER LEVEL ENERGY IMPULSES MOVING THROUGH THE FLOW...ALONG WITH THE
SURFACE COLD FRONT...WILL KEEP CHANCES OF RAIN OR SNOW SHOWERS IN
THE FORECAST THURSDAY NIGHT AND FRIDAY. LOOKING AT LOWS THURSDAY
NIGHT IN THE LOWER 30S...HIGHS FRIDAY IN THE 40S...AND LOWS FRIDAY
NIGHT FROM THE MID 20S TO LOWER 30S.
ON SATURDAY...ANOTHER SHOT OF COLD AIR MOVES INTO THE REGION BEHIND
ANOTHER COLD FRONT. THIS WILL BE ANOTHER DAY OF GUSTY NORTH WEST
WINDS...BUT WINDS ARE NOT EXPECTED TO BE AS STRONG - BUT STILL 15 TO
25 MPH. AGAIN LOOKING AT HIGHS IN THE 40S. ANOTHER SHOT OF A CHANCE
OF RAIN OR SNOW WITH AN UPPER LEVEL IMPULSE ALONG AND BEHIND THE
COLD FRONT.
NORTHERLY FLOW CONTINUES THROUGH MID-WEEK...WITH A HIGHLY AMPLIFIED
RIDGE OVER THE WEST COAST AND TROUGH OVER EASTERN NORTH AMERICA.
HIGHS MAINLY IN THE 40S...AND LOWS FROM THE MID 20S TO LOWER 30S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1259 AM CDT THU OCT 17 2013
AS OF 06 UTC...A BAND OF PRECIPITATION EXTENDED FROM KMOT THROUGH
KDIK AND KBHK. MVFR CONDITIONS IN RAIN ARE EXPECTED WITH THIS
BAND...POSSIBLY MIXED WITH SNOW ACROSS SOUTHWEST NORTH DAKOTA.
THIS BAND OF PRECIPITATION WILL CONTINUE TO MOVE SOUTHEAST THROUGH
THE NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...TWH
LONG TERM...JV
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
935 AM EDT THU OCT 17 2013
.DISCUSSION...COLD FRONT APPEARS TO BE ROUGHLY ALONG A HUNTSVILLE AL
TO JUST WEST OF CROSSVILLE TN TO NEAR LONDON KY LINE AT 13Z. SHOWERS
OUT AHEAD OF THE FRONT HAVE SCATTERED OUT THIS MORNING...BUT NEW
DEVELOPMENT WAS NOTED WEST OF THE FRONT.
LATEST RUC MODEL SHOWS INCREASING DIVERGENCE ALOFT AS THE RIGHT REAR
QUAD OF THE UPPER LEVEL JET PASSES ACROSS TODAY. SOME WEAK POSITIVE
OMEGA WITH THE FRONT AS WELL...AND THESE TWO FACTORS SHOULD BRING AN
INCREASE IN SHOWERS THROUGH THE AFTERNOON HOURS. WILL CONTINUE THE
LIKELY TO CATEGORICAL POPS.
12Z OHX AND RNK SOUNDINGS WERE SATURATED FROM SURFACE THROUGH AROUND
600 MBS...WITH VERY LITTLE SURFACE BASED CAPE INDICATED. SURFACE
BASED POSITIVE CAPE PROGGED TO REACH AROUND 500 J/KG BY 18Z TO 21Z
TODAY...AIDED BY WEAK COLD AIR ADVECTION IN THE MID LEVELS AS THE
UPPER TROUGH APPROACHES. THERE WILL ALSO BE AN AXIS OF WEAK ELEVATED
INSTABILITY THROUGH 18/00Z. THUS...I WILL KEEP A SLIGHT CHANCE OF
THUNDERSTORMS WHERE MENTIONED IN THE EASTERN SECTIONS.
PLAN TO DO A LATE MORNING UPDATE AND FRESHEN ALL PRODUCTS...ALTHO
HOURLY CONDITIONS MATCHING CLOSE TO GRIDS...AND MAX TEMP FORECAST
LOOKS ON TRACK.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 68 47 70 48 70 / 90 10 0 10 20
KNOXVILLE MCGHEE TYSON AIRPORT, TN 68 45 67 45 69 / 80 10 0 10 10
OAK RIDGE, TN 66 44 67 45 69 / 80 10 0 10 10
TRI CITIES AIRPORT, TN 67 42 65 42 67 / 80 20 0 10 20
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1149 PM CDT WED OCT 16 2013
.UPDATE...
UPDATED FOR 06Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 758 PM CDT WED OCT 16 2013/
UPDATE...
UPDATED TO ADJUST THE POPS SLIGHTLY FOR TONIGHT. PUT 40 PERCENT
POPS ACROSS MUCH OF THE AREA WITH 60 PERCENT POPS ALONG THE EXTREME
SOUTHERN PORTIONS OF NORTH MS. RAIN HAD MOVED OUT OF THE MIDSOUTH
AT EARLY EVENING. HOWEVER...A SHORT WAVE APPROACHING FROM THE WEST WILL
TRIGGER ADDITIONAL RAIN LATER TONIGHT. RADARS ALREADY SHOWED SCATTERED
AREAS OF RAIN ACROSS THE WESTERN HALF OF AR MOVING EASTWARD. A
SLOW MOVING COLD FRONT STRETCHES FROM MIDDLE TN INTO CENTRAL MS.
AS THE UPPER SHORT WAVE MOVES INTO MIDSOUTH...SOME ENHANCEMENT OF
RAIN IS FORECAST ACROSS THE EXTREME SOUTHERN PORTIONS OF NORTH
MS CLOSER TO THE COLD FRONT...SO LEFT LIKELY POPS IN THIS AREA.
REMAINDER OF THE ZONE FORECASTS / GRIDS LOOKS FINE WITH JUST SMALL
TWEAKS FOR TONIGHT.
JCL
&&
.DISCUSSION... /ISSUED 315 PM CDT WED OCT 16 2013/
CURRENTLY...A COLD FRONT STRETCHES FROM EASTERN KENTUCKY THROUGH
KCBM INTO LOUISIANA. THE RAIN SHIELD IS PROGRESSING TO THE EAST
AND NOW COVERS AREAS GENERALLY SOUTH OF I-40 AND EAST OF I-55.
CLOUDS COVER MOST OF THE REST OF THE MIDSOUTH THOUGH THE SUN IS
TEMPORARILY PEAKING OUT ACROSS PARTS OF NORTHEAST ARKANSAS. TEMPS
ARE WELL BELOW NORMAL AS MUCH COOLER AIR FILTERS IN WITH READINGS
HOVERING AROUND 60 WITH A LIGHT NNW WIND.
TONIGHT...THE COLD FRONT WILL PUSH SLOWLY EAST. MEANWHILE A WEAK
LOW PRESSURE SYSTEM WILL RIDE NORTHEAST ALONG THE FRONT AS A PIECE
OF UPPER LEVEL ENERGY NOW MOVING THROUGH THE ARKLATEX PUSHES INTO
THE LOWER MISSISSIPPI VALLEY. AS A RESULT THE POST FRONTAL RAIN
SHIELD SHOULD EXPAND OVERNIGHT AND PUSH ACROSS NORTH MISSISSIPPI.
THE 12Z NAM AND LATEST HRRR DEPICT THIS SCENARIO WHILE THE GFS AND
ECMWF ARE LESS BULLISH. WILL ALSO KEEP SMALL POPS ACROSS THE
REMAINDER OF THE AREA AS A MID LEVEL SHORTWAVE PUSHES THROUGH THE
MID MS VALLEY. THIS FEATURE MAY RESULT IN SOME SPOTTY LIGHT
SHOWERS ACROSS THE AREA LATER THIS EVENING AND AFTER MIDNIGHT.
GENERALLY WENT ABOVE TEMP GUIDANCE DUE TO CLOUDS.
THURSDAY...KEPT A SMALL CHANCE OF RAIN ACROSS EASTERN SECTIONS IN
THE MORNING FOLLOWED BY GRADUAL CLEARING AS HIGH PRESSURE BUILDS
IN. TEMPS WILL BE A FEW DEGREES COOLER THAN NORMAL...IN THE UPPER
60S TO AROUND 70.
THURSDAY NIGHT THROUGH FRIDAY...WEAK HIGH PRESSURE WILL PREVAIL
WITH PLEASANT CONDS. MOSTLY CLEAR AND COOL THURSDAY NIGHT WITH
LOWS IN THE 40S. EXPECT A SUNNY START TO FRIDAY FOLLOWED BY
INCREASING CLOUDS IN THE AFTERNOON WITH THE APPROACH OF THE NEXT
SYSTEM. HIGHS WILL BE A COUPLE OF DEGREES WARMER.
FRIDAY NIGHT AND SATURDAY...A WEAK REINFORCING COLD FRONT WILL
PUSH THROUGH FRIDAY NIGHT WITH THE BEST CHANCE FOR SHOWERS ALONG
THE MISSOURI/KY BORDER. MODELS CONTINUE TO TREND TOWARD A DRIER
FORECAST ACROSS SOUTHERN AREAS WITH THE LOW PRESSURE ALONG THE
GULF REMAINING WELL TO THE SOUTH. WILL LEAVE IN SLIGHT CHANCE POPS
ACROSS THE SOUTH FOR NOW BUT THESE MAY NEED TO BE PULLED IF
CURRENT TRENDS HOLD. EXPECT SOME CLEARING BY SATURDAY AFTERNOON
WITH SEASONABLY COOL TEMPS.
SUNDAY THROUGH WEDNESDAY...LOOKS LIKE A PLEASANT STRETCH OF
WEATHER WITH HIGH PRESSURE AT THE SURFACE AND COOL WNW FLOW ALOFT.
A COUPLE OF WEAK REINFORCING FRONT PUSH THROUGH ON TUESDAY AND
AGAIN ON WEDNESDAY BUT THEY ARE MOISTURE STARVED SO REMOVED
MENTION OF POPS FOR NOW. TEMPS WILL BE SEASONABLE THEN TURNING
COOLER BY MIDWEEK. LONG RANGE MODELS ARE HINTING AT A VERY COOL
AIRMASS PUSHING IN BY THU OR FRI OF NEXT WEEK.
SJM
&&
.AVIATION...
06Z TAF CYCLE
A WEAK UPPER LEVEL DISTURBANCE WILL CONTINUE TO LIFT ACROSS THE
OZARKS THIS MORNING...WITH CIGS MAINLY VFR AT MEM...JBR...AND
MKL. THOUGH SOME PATCHY MVFR IS EXPECTED TO DEVELOP ALONG I-40.
FURTHER SOUTH AT TUP IFR CIGS ARE HOLDING STRONG JUST BEHIND A
STALLED FRONT IN WESTERN ALABAMA. BELIEVE THESE LOW CIGS WON`T
BEGIN IMPROVING UNTIL THE AFOREMENTIONED DISTURBANCE LIFTS OUT.
REMOVED LIGHT RAIN AT MEM AND MKL AND REPLACED WITH VCSH AS
COVERAGE APPEARS MORE ISOLATED. EXPECTING VFR AT ALL SITES FOR THE
LAST HALF OF THE TAF PERIOD WITH SKIES CLEARING. NORTHWEST TO NORTH
WINDS WILL REMAIN LIGHT TONIGHT...INCREASING TO 6-8KTS AFTER
SUNRISE...AND FINALLY DIMINISHING AND BECOMING WESTERLY LATE.
JAB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 55 69 49 73 / 40 10 10 10
MKL 53 67 40 70 / 40 20 10 10
JBR 51 68 43 72 / 40 10 10 10
TUP 57 70 47 72 / 50 20 10 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
751 PM CDT FRI OCT 18 2013
.AVIATION...
SHOWERS INCREASING IN COVERAGE OVER THE AREA WELL IN ADVANCE OF
SPEED MAX NEAR KDRT. LIFT SHOULD CONTINUE AND INCREASE QUICKLY
AFTER 04-07Z AS SPEED MAX NEARS. HAVE STARTED WITH VCSH AT MANY
SITES AND TEMPO FOR SHOWERS. AS THE SPEED MAX NEARS EXPECT
COVERAGE TO CONTINUE TO EXPAND WITH THE PEAK BETWEEN 06-10Z FOR
MOST AREAS. AT THE MOMENT THE GUIDANCE IS SHOWING DEEP INSTABILITY
TO THE WEST OF THE REGION WITH A DISTINCT LACK OF DEEP
INSTABILITY OVER SETX TONIGHT AND EXPECT MOSTLY RA/SHRA TONIGHT.
CAN`T RULE OUT ISOLATED TSRA. FRONT IS CRUISING SOUTH AT 21-24
KNOTS AND TIMING THIS PLACES IT INTO CLL AROUND 07Z AND IAH 09Z
AND GLS 12Z. STRONG CAA WILL JACK UP THE WINDS QUICKLY BECOMING
GUSTY. PRECIP SHIELD SHOULD BE SHIFTING EAST AND OUT OF THE AREA
BY AROUND 10-12Z WITH BKN- OVC040-060 FT CIGS. DRYING DEEPENS AND
SHOULD CLEAR THE SKIES BY 16-19Z FROM WEST TO EAST. VFR WITH GUSTY
NORTH WINDS RELAXING AFTER 21Z BUT WILL PROBABLY COME BACK UP NEAR
THE COAST WITH TEMPERATURES DIPPING LATE IN THE AFTERNOON/EVENING.
45
&&
.PREV DISCUSSION... /ISSUED 345 PM CDT FRI OCT 18 2013/
DISCUSSION...
WIDESPREAD SHOWERS WITH ISOLATED THUNDER HAVE BEEN GOING ON OVER
THE WATERS TODAY. ISOLATED TO SCATTERED COVERAGE HAS BEEN OBSERVED
ALONG THE COASTAL COUNTIES. THIS IS ALL IN THANKS TO WIDESPREAD
ISENTROPIC LIFT. THE 850MB MOISTURE AXIS HAS CONTINUED TO PUSH TO
THE NORTHEAST FROM THE SOUTHWEST THIS AFTERNOON ALLOWING FOR MORE
OF THE RAIN TO REACH THE GROUND THIS AFTERNOON. INSTABILITY
REMAINS LIMITED THOUGH SO THUNDER LOOKS TO BE ISOLATED. A SOUNDING
FROM KCLL AT 15Z SHOWS A SATURATED LAYER JUST ABOVE 800MB TO ABOUT
600MB. INSTABILITY IS LIMITED. LOW LEVEL DRY AIR SHOULD START TO
ERODE AS THE THE WARM FRONT LIFTS NORTHWARDS.
COMPARING A 250MB HAND ANALYSIS FROM THIS MORNING THE ECMWF SEEMS
TO HAVE THE POSITION OF THE JET BEST. BOTH MODELS ARE CLOSE
THOUGH. EITHER WAY SOUTHEAST TEXAS IS IN THE RRQ OR DIVERGENT
REGION OF THE JET STREAK. THIS IN COMBINATION WITH A COLD FRONT
WILL HELP PROVIDE THE LIFTING MECHANISMS FOR RAIN THROUGH THE
EVENING HOURS. THE TEXAS TECH WRF HAS PRECIP LIMITED WITH THE
FRONT WHILE THE HRRR HAS WIDESPREAD RAIN AHEAD OF THE FRONT. BOTH
MODELS SEEMED TO HAVE INITIALIZED WELL. GIVEN SPOTTY COVERAGE NOW
HAVE LEANED TOWARDS THE WETTER SOLUTION. WAS A BIT HESITANT THOUGH
GIVEN WIDESPREAD CONVECTION ONGOING OVER WATERS. THIS COULD HINDER
THE DEVELOPMENT INLAND. BEHIND THIS FRONT BOTH ECMWF AND GFS
POSITION THE SURFACE HIGH PRESSURE OVER CENTRAL TEXAS SUNDAY
MORNING. THIS WILL ALLOW TEMPERATURES TO DROP INTO THE 40S FOR
MOST INLAND LOCATIONS.
THIS FRONT WILL AGAIN BE SHORT LIVED THOUGH AS IT BEGINS TO PULL
NORTHWARDS ON MONDAY. A SIMILAR SET UP TO THIS EVENING WILL AGAIN
BE ON TAP MONDAY NIGHT INTO TUESDAY. THE GFS AND ECMWF APPEAR TO
BE IN AGREEMENT WITH THE BEST UPPER LEVEL DIVERGENCE TO BE OFF THE
COAST AND THEN MOVING INTO LA. BEHIND THIS FRONT A SURFACE HIGH
PRESSURE WILL MOVE DOWN ALLOWING FOR PLEASANT CONDITIONS BEHIND
THE FRONT. THE GFS AND ECMWF HAVE THE BULK OF THE HIGH PRESSURE
MOVING OFF TOWARDS THE EAST IN ASSOCIATION WITH THE LONG WAVE
TROUGH. THIS SHOULD STILL ALLOW FOR NICE CONDITIONS TO CONTINUE
THOUGH THE REMAINDER OF THE WORK WEEK. 23
MARINE...
DIFFICULT MARINE FORECAST THIS AFTERNOON...AND MARINERS ARE URGED
TO CLOSELY MONITOR THE WEATHER AND WEATHER FORECASTS OVER THE NEXT
SEVERAL DAYS FOR POSSIBLE CHANGES. WINDS THAT HAVE BEEN AT CAUTION
LEVELS OFF THE COAST FOR SEVERAL HOURS NOW SHOULD COME DOWN LATER
THIS AFTERNOON AND THIS EVENING AS THE NEXT COLD FRONT APPROACHES
THE AREA. AFTER THE FRONTAL PASSAGE LATE TONIGHT THROUGH EARLY
TOMORROW MORNING...WINDS ARE EXPECTED TO STRENGTHEN AGAIN TO CAUTION
LEVELS FOR THE BAYS AND CLOSE TO ADVISORY LEVELS OFF THE COAST.
INSTEAD OF CARRYING FLAGS THIS AFTERNOON THEN LOWERING THEM THIS
EVENING THEN RAISING THEM AGAIN BEFORE SUNRISE...DECIDED TO JUST
KEEP FLAGS UP THROUGH TOMORROW AS THIS STORM SYSTEM AND ASSOCIATED
SHOWERS AND THUNDERSTORMS MOVE ON THROUGH. WINDS AND SEAS SHOULD
COME DOWN LATE SATURDAY AFTERNOON AND ON INTO SATURDAY NIGHT...THEN
PICK UP AGAIN ON MONDAY NIGHT AND TUESDAY AFTER THE PASSAGE OF THE
NEXT STORM SYSTEM AND COLD FRONT. ELEVATED WINDS AND SEAS EXPECTED
TO THEN PERSIST INTO THE MIDDLE OF THE WEEK SHOULD COME DOWN DURING
THE SECOND HALF OF THE WEEK AS HIGH PRESSURE BUILDS INTO THE AREA
AND THE GRADIENT RELAXES. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 53 69 47 75 58 / 60 20 10 0 20
HOUSTON (IAH) 59 73 50 78 60 / 60 30 10 0 20
GALVESTON (GLS) 68 75 62 76 68 / 70 50 10 10 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION FROM 4 AM CDT SATURDAY
THROUGH SATURDAY AFTERNOON FOR THE FOLLOWING ZONES:
GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY FROM 4 AM TO 6 PM CDT SATURDAY FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 AM CDT SATURDAY FOR
THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA
SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...41
AVIATION/MARINE...45
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
912 PM CDT FRI OCT 18 2013
.UPDATE...
ISSUED AT 911 PM CDT FRI OCT 18 2013
THE CHANCES FOR PRECIPITATION TONIGHT INTO EARLY SATURDAY MORNING
ARE LOOKING LESS LIKELY NOW. THE FOCUS FOR PRECIPITATION TONIGHT
WAS ON A SHORTWAVE COMING ACROSS SOUTHWEST MINNESOTA. KMPX RADAR
SHOWS A BAND OF LIGHT RETURNS WHICH AT MOST HAVE PRODUCED
SPRINKLES AT REDWOOD FALLS IN THE PAST HOUR. OTHERWISE...THE BULK
OF THE RETURNS ARE VIRGA...DUE TO DRY LOW LEVEL AIR BELOW THE
7000-8000 FT CLOUD BASES AS SEEN ON THE 00Z MPX SOUNDING. RECENT
HRRR MODEL RUNS HAVE HAD A GOOD HANDLE ON THIS BAND OF LIGHT
PRECIPITATION...SUGGESTING IT WILL DIMINISH AS IT MOVES FURTHER
EAST INTO THE DRIER AIR. ADDITIONALLY...THE FORCING OVERALL FROM
THE SHORTWAVE JUST SEEMS TO BE WEAKENING. BELIEVE THIS IS DUE TO A
SOMEWHAT STRONGER SHORTWAVE DROPPING INTO EASTERN NORTH DAKOTA AS
SEEN ON WATER VAPOR. ADDITIONALLY...THIS SHORTWAVE HAS A 100-110
KT JET STREAK AT THE TROPOPAUSE ON ITS WESTERN SIDE PER RAP
ANALYSIS. THIS SHORTWAVE WILL BRING A MUCH GREATER CHANCE FOR
PRECIPITATION TO THE FORECAST AREA. TIMING OF THIS PRECIPITATION
HAS BECOME MORE PROBLEMATIC BY THE 18.23Z HRRR HAVING IT STILL
WEST OF I-35 AT 14Z...COMPARED TO THE 18.18Z NAM AND 18.15Z SREF
WHICH SUGGESTED IT ALREADY NEARING RST AT THE TIME.
FOR THE PRECIPITATION FORECAST...HAVE LOWERED CHANCES TO BASICALLY
DRY TONIGHT TO ABOUT 13-14Z SATURDAY MORNING. ONLY LEFT A 20
PERCENT CHANCE AROUND TAYLOR COUNTY PER 18.18Z NAM SUGGESTING
TAYLOR COUNTY COULD GET BRUSHED. CHANCES THEN RAMP UP WEST TO EAST
TO 60 BETWEEN THE 15-19Z PERIOD AS THE NEXT SHORTWAVE AND UPPER
JET STREAK FORCING IMPACTS THE AREA.
TEMPERATURES ARE AN ISSUE TONIGHT TOO. WHERE BREAKS HAVE DEVELOPED
IN THE CIRRUS OVER CENTRAL WISCONSIN...READINGS HAVE ALREADY
DROPPED TO NEAR/AROUND FREEZING. EVEN OVER SOUTHEAST MN DODGE
CENTER HAS FALLEN TO 35. HAVE LOWERED TEMPERATURES A FEW
DEGREES...BUT A STREAM OF BROKEN MID CLOUDS ACROSS MINNESOTA AND
NORTHWEST IOWA WILL MOVE THROUGH THE AREA OVERNIGHT. THESE CLOUDS
MAY CAUSE TEMPERATURES TO FLUCTUATE QUITE A BIT. ADDED AT LEAST
SOME PATCHY-AREAS OF FROST MENTION TO MUCH OF THE FORECAST
AREA RESULTING FROM THE LOWERING OF TEMPERATURES. CONFIDENCE IS
NOT HIGH ENOUGH TO ISSUE ANY FROST ADVISORIES IN OUR AREA THAT ARE
STILL ACTIVE / COUNTIES WEST OF I-94 / GIVEN CLOUD ISSUES.
&&
.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 333 PM CDT FRI OCT 18 2013
MAIN FORECAST CONCERN IS COLDER THAN NORMAL TEMPERATURES AND BOUTS
OF PRECIPITATION.
WATER VAPOR IMAGERY FEATURES A DEEP/ELONGATED LONGWAVE TROUGH OF LOW
PRESSURE EXTENDING FROM WESTERN HUDSONS BAY CANADA THROUGH THE UPPER
MISSISSIPPI RIVER AND INTO THE DESSERT SOUTHWEST. WITHIN THE LONGWAVE
TROUGH...A SHORTWAVE TROUGH WAS DROPPING SOUTHWARD OUT OF SOUTHERN
SASKATCHEWAN. VISIBLE SATELLITE SHOWING THE RESULT OF THE VERY
CHILLY AIR ALOFT WITH WIDESPREAD CUMULUS/STRATOCUMULUS ACROSS THE
DAKOTAS INTO MN/WESTERN WI. RADAR MOSAIC WAS EVEN SHOWING ISOLATED
SHOWERS ACTIVITY ACROSS NORTHEAST MN AND THE EASTERN DAKOTAS IN
ADVANCE OF THE SASKATCHEWAN WAVE. OTHERWISE...UNSEASONABLY COOL
AIRMASS IN PLACE ACROSS THE REGION WITH TEMPERATURES THIS AFTERNOON
STRUGGLING THROUGH THE 40S TO NEAR 50. THIS IS SOME 10-15 DEGREES BELOW
NORMAL.
FOR TONIGHT...THE WAVE OVER SASKATCHEWAN WILL DEEPEN SLIGHTLY AND
MOVE SOUTHEASTWARD INTO THE EASTERN DAKOTAS. NOT MUCH FORCING
ASSOCIATED WITH THIS WAVE OTHER THAN STEEPENING LAPSE RATES AND
SLIGHTLY INCREASED CYCLONIC FLOW. BASED ON THIS...WILL GO WITH
SMALL-END PRECIPITATION PROBABILITIES. IF SHOWERS DO DEVELOP...
THERMAL PROFILES SUPPORT MAINLY RAIN BUT CANNOT RULE OUT SOME SNOW
FLAKES NORTHEAST OF I-94. LOOK FOR OVERNIGHT LOWS IN THE MIDDLE TO
UPPER 30S.
AS THE TROUGH ROTATES OVER THE AREA SATURDAY...A STEEPENING LAPSE
RATE OF 8-10C/KM IN THE LOWEST 3KM AND CYCLONIC FLOW IS EXPECTED TO
GENERATE SCATTERED-NUMEROUS RAIN SHOWERS. OTHERWISE...PLAN ON HIGHS
IN THE 40S.
A FEW SHOWERS MAY LINGER INTO SATURDAY EVENING NORTHEAST OF
I-94...BUT THEN CLEARING IS EXPECTED LATER INTO THE EVENING AND
OVERNIGHT AS A WEAK RIDGE OF HIGH PRESSURE PASSES OVERHEAD. THIS
WILL SET UP GOOD RADIATIONAL COOLING WITH AREAS-WIDESPREAD FROST
LIKELY FOR MOST AREAS. OVERNIGHT LOWS ARE EXPECTED TO BOTTOM OUT IN
THE UPPER 20S NORTHEAST OF I-94...TO NEAR THE FREEZING MARK FOR ALL
OTHER LOCATIONS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 333 PM CDT FRI OCT 18 2013
MODELS SHOWING A FAIRLY VIGOROUS MID-LEVEL TROUGH AND SURFACE LOW
DROPPING ACROSS THE DAKOTAS INTO SOUTHERN MN/WESTERN WI BY SUNDAY
AFTERNOON. MODELS SHOWING FAIRLY STRONG 850-500MB
PV-ADVECTION/ISENTROPIC LIFT ASSOCIATED WITH THIS WAVE. THIS HAS
BEEN A VERY CONSISTENT SIGNAL FOR THE LAST FEW DAYS OF MODEL RUNS
NOW. BASED ON THIS...WILL GO WITH LIKELY TO CATEGORICAL
PROBABILITIES ALONG AND NORTHEAST OF I-94...TAPERING TO CHANCES TO
THE SOUTH OF I-94. THERMAL PROFILES HINT THERE MAY BE A CHANCE THAT
AS THE PRECIPITATION MOVES IN SUNDAY MORNING...IT MAY FALL AS A
SNOW/RAIN MIX NORTH OF I-94. OTHERWISE WITH TEMPERATURES MODERATING
INTO THE 40S AND LOWER 50S DURING THE DAY...LOOK FOR THIS
PRECIPITATION TO BE ALL RAIN FROM MID-MORNING ONWARD THROUGH THE
REST OF THE DAY.
THIS LOW PULLS OFF INTO UPPER MICHIGAN SUNDAY EVENING...SPILLING
COLDER AIR INTO THE AREA. DEPENDING ON THE TIMING OF THIS COLD AIR
WITH THE TAPERING PRECIPITATION...THERE COULD BE A SLUSHY 1/4-1/2
INCH ACROSS NORTHERN PARTS OF TAYLOR COUNTY. THE PRECIPITATION IS
EXPECTED TO DIMINISH COMPLETELY AFTER MIDNIGHT AS THE LOW PULLS INTO
SOUTHERN ONTARIO. LOOK FOR OVERNIGHT LOWS IN THE 30-35 DEGREE RANGE.
ON MONDAY...MODELS SHOWING ANOTHER MID-LEVEL SHORTWAVE TROUGH
ROTATING SOUTHWARD AROUND THE NOW CLOSED/STACKED LOW OVER SOUTHERN
ONTARIO...INTO NORTHERN MN/WI. THE NAM IS SPREADS PRECIPITATION
FARTHEST SOUTH INTO THE AREA ASSOCIATED WITH THIS WAVE. MODEL
CONSENSUS YIELDS A 20-40 PERCENT PROBABILITY OF PRECIPITATION NORTH
OF I-94 WITH THE BULK OF THE PRECIPITATION STAYING NORTH OF THE
AREA. AGAIN...THERMAL PROFILES SHOW PRECIPITATION COULD BE ALL SNOW
IN THE MORNING...CHANGING TO ALL RAIN DURING THE REST OF THE DAY AS
HIGHS TO OFF IN THE UPPER 30S TO THE MIDDLE 40S.
THE EXTENDED MODELS CONTINUE TO SHOW A DEEP TROUGH ACROSS THE
EASTERN CONUS THROUGH THE REST OF THE PERIOD AS A RIDGE BUILDS OVER
THE WEST COAST. THIS KEEPS OUR AREA IN NORTHWEST FLOW ALOFT WITH
TEMPERATURES REMAINING SOME 10 DEGREES BELOW NORMAL WITH HIGHS ONLY
ON THE 40S. WITH MODELS HAVING A HARD TIME WITH STRENGTH AND
TIMING OF WEAKER WAVES RIPPLING THROUGH THIS NORTHWEST
FLOW...MODEL CONSENSUS IS FOR GENERALLY DRY STRETCH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 605 PM CDT FRI OCT 18 2013
DRY AIR ASSOCIATED WITH A RIDGE OF HIGH PRESSURE OVER THE TAF
SITES HAS KEPT CONDITIONS VFR THIS AFTERNOON. THESE VFR CONDITIONS
LOOK TO PERSIST THROUGH THE NIGHT AS THAT DRY AIR STAYS IN PLACE.
NOW THERE IS A WEAKENING LOW PRESSURE TROUGH OVER EASTERN SOUTH
DAKOTA EXPECTED TO MOVE THROUGH THE TAF SITES OVERNIGHT...WHICH
COULD BRING SOME VFR STRATOCUMULUS AND EVEN A FEW SHOWERS.
CONFIDENCE ON THESE SHOWERS IS TOO LOW TO MENTION IN THE TAFS...
THOUGH. A HIGHER CHANCE OF RAIN COMES 15-16Z AT THE TAF SITES
ASSOCIATED WITH A STRONGER COLD FRONT PROGGED TO MOVE THROUGH.
THESE SHOWERS ARE LIKELY TO BRING CEILINGS DOWN TO MVFR AT RST AND
JUST ABOVE MVFR AT LSE. THERE COULD EVEN BE SOME VISIBILITY
RESTRICTIONS BELOW VFR IF THE SHOWERS ARE HEAVY ENOUGH. CEILINGS
SHOULD CLIMB IN THE WAKE OF THE FRONT AS WINDS TURN WEST-
NORTHWESTERLY...BUT KEPT RST AT MVFR AT THIS TIME. CEILINGS ARE
MORE LIKELY TO CLIMB TO VFR AT RST AROUND 00Z SATURDAY EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1240 PM CDT THU OCT 17 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CDT THU OCT 17 2013
MAIN FORECAST CONCERNS ARE ON RAIN CHANCES TONIGHT INTO FRIDAY
MORNING. FOCUS THEN TURNS TO PRECIPITATION CHANCES AND TEMPERATURES
THROUGH THE WEEKEND.
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED A TROUGH
MOVING ACROSS SOUTHERN IOWA/NORTHERN ILLINOIS. AN ELONGATED TROUGH
WAS STRETCHING FROM THE WESTERN SHORES OF HUDSONS BAY SOUTHWEST
THROUGH THE CENTRAL ROCKIES AND MOVING EAST. THIS WILL BE THE NEXT
FEATURE THAT IMPACTS THE REGION BRINGING MUCH COOLER AIR WITH IT.
SURFACE OBSERVATIONS SHOWED A COLD FRONT STRETCHING FROM WESTERN
ONTARIO SOUTHWEST THROUGH NORTHWEST MINNESOTA INTO THE NEBRASKA PAN
HANDLE AND WAS MOVING EAST.
A WEAK SURFACE RIDGE CURRENTLY OVER THE FORECAST AREA WILL SLIDE
EAST TODAY AS THE COLD FRONT PUSHES EAST INTO THE UPPER
MISSISSIPPI RIVER VALLEY. CLOUDS WILL GRADUALLY INCREASE FROM THE
NORTHWEST TODAY AS THE COLD FRONT MOVES IN. THE FRONT IS EXPECTED
TO PUSH ACROSS THE FORECAST AREA THIS EVENING. A BAND OF RAIN
SHOWERS IS EXPECTED BEHIND THE FRONT...ALONG A BAND OF
FRONTOGENESIS IN THE 900-750 MB LAYER. FORECAST MODELS ARE IN VERY
CLOSE AGREEMENT REGARDING THE TIMING OF THIS BAND BRINGING THE
RAIN THROUGH THE FORECAST AREA LATE TONIGHT INTO EARLY FRIDAY
MORNING. HOWEVER THERE IS SOME UNCERTAINTY IN HOW FAR SOUTH THE
PRECIPITATION WILL FALL. MODEL CONSENSUS WOULD PLACE IN MAINLY
ALONG AND NORTH OF THE I-90 CORRIDOR...WITH HIGHER CHANCES NORTH
OF THE I-94 CORRIDOR...SO HAVE INCREASED PRECIPITATION CHANCES
OVER THESE AREAS. PLAN ON OVERNIGHT LOWS FALLING INTO THE UPPER
30S TO AROUND 40.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 AM CDT THU OCT 17 2013
THE FORECAST AREA WILL BE IN BETWEEN SYSTEMS LATE FRIDAY MORNING
INTO FRIDAY AFTERNOON AS THE LEADING TROUGH PUSHES EAST OF THE AREA.
ANOTHER TROUGH DIGS INTO THE REGION FRIDAY NIGHT INTO SATURDAY
MORNING. THIS TROUGH WILL MAKE ITS WAY ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY DURING THE DAY ON SATURDAY. WITH THE TROUGH MOVING
THROUGH AND THE COOL AIR ALOFT...WIDESPREAD RAIN SHOWERS ARE
EXPECTED. THE RAIN AND CLOUD COVER WILL HELP HOLD TEMPERATURES DOWN
ON SATURDAY WITH HIGHS ONLY IN THE 40S. THE SHOWERS WILL TAPER OFF
LATE SATURDAY AFTERNOON INTO SATURDAY EVENING AS A WEAK SURFACE
RIDGE MOVES OVER THE AREA. CHILLY OVERNIGHT LOWS ARE EXPECTED
SATURDAY NIGHT WITH LOWS FALLING INTO THE UPPER 20S TO AROUND 30.
ANOTHER TROUGH DIVES INTO THE EASTERN DAKOTAS AND NORTHERN
MINNESOTA DURING THE DAY ON SUNDAY THEN DIGS INTO THE UPPER
MISSISSIPPI RIVER VALLEY SUNDAY NIGHT. THIS FEATURE WILL BRING
UNSEASONABLY CHILLY AIR WITH IT. 850 MB TEMPERATURES LOOK TO FALL
TO AROUND -8 C BY MONDAY EVENING. 850 MB TEMPERATURES STANDARDIZED
ANOMALIES FALL TO -2.0 TO -1.5 BY 00Z TUESDAY. THE TROUGH WILL
BRING CHANCES FOR RAIN AND POSSIBLY SOME SNOW TO THE AREA FROM
LATE SUNDAY AFTERNOON THROUGH MONDAY. SOME SLUSHY LIGHT SNOW
ACCUMULATIONS CANNOT BE RULED OUT OVER FAR NORTHERN WISCONSIN. THE
UNSEASONABLY COLD AIR LOOKS TO REMAIN OVER THE REGION WELL INTO
NEXT WEEK WITH HIGHS IN THE 40S AND LOWS IN THE UPPER 20S TO LOWER
30S. FORECAST MODELS ARE SHOWING SOME DIFFERENCES REGARDING THE
TIMING AND PLACEMENT OF PRECIPITATION FROM MONDAY NIGHT THROUGH
WEDNESDAY. THE ECMWF OFFERS THE FASTEST SOLUTIONS BRINGING A
POTENT TROUGH THROUGH THE REGION MONDAY NIGHT THROUGH TUESDAY
MORNING. THE GFS IS SLOWER BRINGING THIS FEATURE THROUGH TUESDAY
INTO TUESDAY NIGHT. WILL LEAN TOWARD A MODEL CONSENSUS BLEND FROM
MONDAY NIGHT THROUGH TUESDAY FOR PRECIPITATION CHANCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1240 PM CDT THU OCT 17 2013
CURRENTLY WATCHING A FAIRLY VIGOROUS MID-LEVEL TROUGH OF LOW
PRESSURE ROTATING EASTWARD ACROSS THE DAKOTAS. AT THE SURFACE...A
COLD FRONT EXTENDED FROM THE ARROWHEAD OF MN THROUGH EASTERN MN
INTO WESTERN IA. LOOK FOR THIS SYSTEM TO MOVE ACROSS THE AREA LATE
THIS AFTERNOON AND OVERNIGHT...FINALLY EXITING EAST BY FRIDAY
AFTERNOON. LOOK FOR VFR CONDITIONS THIS AFTERNOON TO DETERIORATE
INTO MVFR WITH SCATTERED SHRA ACTIVITY IN THE VICINITY OF KRST AFT
03Z AND KLSE BY 05Z. AS THE SYSTEM PULLS EAST LATER FRIDAY
MORNING...CONDITIONS EXPECTED TO IMPROVE BACK INTO VFR AT KRST
15Z. IN ADDITION...PLAN ON WINDS VEERING TO THE NORTHWEST WITH THE
FRONTAL PASSAGE THIS EVENING...WITH SOME GUSTINESS AFTER MIDNIGHT
AT KRST INTO THE 15 TO 25KT RANGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
645 AM CDT THU OCT 17 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CDT THU OCT 17 2013
MAIN FORECAST CONCERNS ARE ON RAIN CHANCES TONIGHT INTO FRIDAY
MORNING. FOCUS THEN TURNS TO PRECIPITATION CHANCES AND TEMPERATURES
THROUGH THE WEEKEND.
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED A TROUGH
MOVING ACROSS SOUTHERN IOWA/NORTHERN ILLINOIS. AN ELONGATED TROUGH
WAS STRETCHING FROM THE WESTERN SHORES OF HUDSONS BAY SOUTHWEST
THROUGH THE CENTRAL ROCKIES AND MOVING EAST. THIS WILL BE THE NEXT
FEATURE THAT IMPACTS THE REGION BRINGING MUCH COOLER AIR WITH IT.
SURFACE OBSERVATIONS SHOWED A COLD FRONT STRETCHING FROM WESTERN
ONTARIO SOUTHWEST THROUGH NORTHWEST MINNESOTA INTO THE NEBRASKA PAN
HANDLE AND WAS MOVING EAST.
A WEAK SURFACE RIDGE CURRENTLY OVER THE FORECAST AREA WILL SLIDE
EAST TODAY AS THE COLD FRONT PUSHES EAST INTO THE UPPER
MISSISSIPPI RIVER VALLEY. CLOUDS WILL GRADUALLY INCREASE FROM THE
NORTHWEST TODAY AS THE COLD FRONT MOVES IN. THE FRONT IS EXPECTED
TO PUSH ACROSS THE FORECAST AREA THIS EVENING. A BAND OF RAIN
SHOWERS IS EXPECTED BEHIND THE FRONT...ALONG A BAND OF
FRONTOGENESIS IN THE 900-750 MB LAYER. FORECAST MODELS ARE IN VERY
CLOSE AGREEMENT REGARDING THE TIMING OF THIS BAND BRINGING THE
RAIN THROUGH THE FORECAST AREA LATE TONIGHT INTO EARLY FRIDAY
MORNING. HOWEVER THERE IS SOME UNCERTAINTY IN HOW FAR SOUTH THE
PRECIPITATION WILL FALL. MODEL CONSENSUS WOULD PLACE IN MAINLY
ALONG AND NORTH OF THE I-90 CORRIDOR...WITH HIGHER CHANCES NORTH
OF THE I-94 CORRIDOR...SO HAVE INCREASED PRECIPITATION CHANCES
OVER THESE AREAS. PLAN ON OVERNIGHT LOWS FALLING INTO THE UPPER
30S TO AROUND 40.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 AM CDT THU OCT 17 2013
THE FORECAST AREA WILL BE IN BETWEEN SYSTEMS LATE FRIDAY MORNING
INTO FRIDAY AFTERNOON AS THE LEADING TROUGH PUSHES EAST OF THE AREA.
ANOTHER TROUGH DIGS INTO THE REGION FRIDAY NIGHT INTO SATURDAY
MORNING. THIS TROUGH WILL MAKE ITS WAY ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY DURING THE DAY ON SATURDAY. WITH THE TROUGH MOVING
THROUGH AND THE COOL AIR ALOFT...WIDESPREAD RAIN SHOWERS ARE
EXPECTED. THE RAIN AND CLOUD COVER WILL HELP HOLD TEMPERATURES DOWN
ON SATURDAY WITH HIGHS ONLY IN THE 40S. THE SHOWERS WILL TAPER OFF
LATE SATURDAY AFTERNOON INTO SATURDAY EVENING AS A WEAK SURFACE
RIDGE MOVES OVER THE AREA. CHILLY OVERNIGHT LOWS ARE EXPECTED
SATURDAY NIGHT WITH LOWS FALLING INTO THE UPPER 20S TO AROUND 30.
ANOTHER TROUGH DIVES INTO THE EASTERN DAKOTAS AND NORTHERN
MINNESOTA DURING THE DAY ON SUNDAY THEN DIGS INTO THE UPPER
MISSISSIPPI RIVER VALLEY SUNDAY NIGHT. THIS FEATURE WILL BRING
UNSEASONABLY CHILLY AIR WITH IT. 850 MB TEMPERATURES LOOK TO FALL
TO AROUND -8 C BY MONDAY EVENING. 850 MB TEMPERATURES STANDARDIZED
ANOMALIES FALL TO -2.0 TO -1.5 BY 00Z TUESDAY. THE TROUGH WILL
BRING CHANCES FOR RAIN AND POSSIBLY SOME SNOW TO THE AREA FROM
LATE SUNDAY AFTERNOON THROUGH MONDAY. SOME SLUSHY LIGHT SNOW
ACCUMULATIONS CANNOT BE RULED OUT OVER FAR NORTHERN WISCONSIN. THE
UNSEASONABLY COLD AIR LOOKS TO REMAIN OVER THE REGION WELL INTO
NEXT WEEK WITH HIGHS IN THE 40S AND LOWS IN THE UPPER 20S TO LOWER
30S. FORECAST MODELS ARE SHOWING SOME DIFFERENCES REGARDING THE
TIMING AND PLACEMENT OF PRECIPITATION FROM MONDAY NIGHT THROUGH
WEDNESDAY. THE ECMWF OFFERS THE FASTEST SOLUTIONS BRINGING A
POTENT TROUGH THROUGH THE REGION MONDAY NIGHT THROUGH TUESDAY
MORNING. THE GFS IS SLOWER BRINGING THIS FEATURE THROUGH TUESDAY
INTO TUESDAY NIGHT. WILL LEAN TOWARD A MODEL CONSENSUS BLEND FROM
MONDAY NIGHT THROUGH TUESDAY FOR PRECIPITATION CHANCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 645 AM CDT THU OCT 17 2013
FG HAS DEVELOPING IN THE RIVER VALLEYS AND HAS SLOSHED ACROSS KLSE
EARLY THIS MORNING ON FAVORABLE LIGHT SOUTHEAST WINDS. SOME
IMPROVEMENT OVER THE PAST HOUR AS HIGH CLOUDS HAVE FILTERED IN FROM
THE SOUTH. THIS WILL LIKELY RESULT IN FURTHER IMPROVEMENT OVER THE
NEXT COUPLE HOURS...ALTHOUGH WOULD NOT SURPRISE IF KLSE FLUCTUATED
BELOW 1SM FOR ANOTHER HOUR.
HIGH/MID LEVEL CLOUDS WILL CONTINUE TO SPREAD EASTWARD ACROSS THE
REGION TODAY...THICKENING AND LOWERING THIS EVENING AS A COLD
FRONT/UPPER LEVEL SHORTWAVE MOVES IN FROM THEN NORTHERN PLAINS. SOME
-SHRA ARE EXPECTED MOSTLY POST FRONT AND NORTH...BUT THE SOUTHERN
FLANK OF THE PCPN COULD SLIP ACROSS KRST/KLSE. SEE A POTENTIAL FOR
MVFR CIGS AS THE SYSTEM TRACKS THROUGH...PER RH FIELDS/BUFKIT
SOUNDINGS/AND CURRENT OBSERVATIONS. WILL ADD A MENTION TO THE
FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
309 AM CDT THU OCT 17 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CDT THU OCT 17 2013
MAIN FORECAST CONCERNS ARE ON RAIN CHANCES TONIGHT INTO FRIDAY
MORNING. FOCUS THEN TURNS TO PRECIPITATION CHANCES AND TEMPERATURES
THROUGH THE WEEKEND.
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED A TROUGH
MOVING ACROSS SOUTHERN IOWA/NORTHERN ILLINOIS. AN ELONGATED TROUGH
WAS STRETCHING FROM THE WESTERN SHORES OF HUDSONS BAY SOUTHWEST
THROUGH THE CENTRAL ROCKIES AND MOVING EAST. THIS WILL BE THE NEXT
FEATURE THAT IMPACTS THE REGION BRINGING MUCH COOLER AIR WITH IT.
SURFACE OBSERVATIONS SHOWED A COLD FRONT STRETCHING FROM WESTERN
ONTARIO SOUTHWEST THROUGH NORTHWEST MINNESOTA INTO THE NEBRASKA PAN
HANDLE AND WAS MOVING EAST.
A WEAK SURFACE RIDGE CURRENTLY OVER THE FORECAST AREA WILL SLIDE
EAST TODAY AS THE COLD FRONT PUSHES EAST INTO THE UPPER
MISSISSIPPI RIVER VALLEY. CLOUDS WILL GRADUALLY INCREASE FROM THE
NORTHWEST TODAY AS THE COLD FRONT MOVES IN. THE FRONT IS EXPECTED
TO PUSH ACROSS THE FORECAST AREA THIS EVENING. A BAND OF RAIN
SHOWERS IS EXPECTED BEHIND THE FRONT...ALONG A BAND OF
FRONTOGENESIS IN THE 900-750 MB LAYER. FORECAST MODELS ARE IN VERY
CLOSE AGREEMENT REGARDING THE TIMING OF THIS BAND BRINGING THE
RAIN THROUGH THE FORECAST AREA LATE TONIGHT INTO EARLY FRIDAY
MORNING. HOWEVER THERE IS SOME UNCERTAINTY IN HOW FAR SOUTH THE
PRECIPITATION WILL FALL. MODEL CONSENSUS WOULD PLACE IN MAINLY
ALONG AND NORTH OF THE I-90 CORRIDOR...WITH HIGHER CHANCES NORTH
OF THE I-94 CORRIDOR...SO HAVE INCREASED PRECIPITATION CHANCES
OVER THESE AREAS. PLAN ON OVERNIGHT LOWS FALLING INTO THE UPPER
30S TO AROUND 40.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 AM CDT THU OCT 17 2013
THE FORECAST AREA WILL BE IN BETWEEN SYSTEMS LATE FRIDAY MORNING
INTO FRIDAY AFTERNOON AS THE LEADING TROUGH PUSHES EAST OF THE AREA.
ANOTHER TROUGH DIGS INTO THE REGION FRIDAY NIGHT INTO SATURDAY
MORNING. THIS TROUGH WILL MAKE ITS WAY ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY DURING THE DAY ON SATURDAY. WITH THE TROUGH MOVING
THROUGH AND THE COOL AIR ALOFT...WIDESPREAD RAIN SHOWERS ARE
EXPECTED. THE RAIN AND CLOUD COVER WILL HELP HOLD TEMPERATURES DOWN
ON SATURDAY WITH HIGHS ONLY IN THE 40S. THE SHOWERS WILL TAPER OFF
LATE SATURDAY AFTERNOON INTO SATURDAY EVENING AS A WEAK SURFACE
RIDGE MOVES OVER THE AREA. CHILLY OVERNIGHT LOWS ARE EXPECTED
SATURDAY NIGHT WITH LOWS FALLING INTO THE UPPER 20S TO AROUND 30.
ANOTHER TROUGH DIVES INTO THE EASTERN DAKOTAS AND NORTHERN
MINNESOTA DURING THE DAY ON SUNDAY THEN DIGS INTO THE UPPER
MISSISSIPPI RIVER VALLEY SUNDAY NIGHT. THIS FEATURE WILL BRING
UNSEASONABLY CHILLY AIR WITH IT. 850 MB TEMPERATURES LOOK TO FALL
TO AROUND -8 C BY MONDAY EVENING. 850 MB TEMPERATURES STANDARDIZED
ANOMALIES FALL TO -2.0 TO -1.5 BY 00Z TUESDAY. THE TROUGH WILL
BRING CHANCES FOR RAIN AND POSSIBLY SOME SNOW TO THE AREA FROM
LATE SUNDAY AFTERNOON THROUGH MONDAY. SOME SLUSHY LIGHT SNOW
ACCUMULATIONS CANNOT BE RULED OUT OVER FAR NORTHERN WISCONSIN. THE
UNSEASONABLY COLD AIR LOOKS TO REMAIN OVER THE REGION WELL INTO
NEXT WEEK WITH HIGHS IN THE 40S AND LOWS IN THE UPPER 20S TO LOWER
30S. FORECAST MODELS ARE SHOWING SOME DIFFERENCES REGARDING THE
TIMING AND PLACEMENT OF PRECIPITATION FROM MONDAY NIGHT THROUGH
WEDNESDAY. THE ECMWF OFFERS THE FASTEST SOLUTIONS BRINGING A
POTENT TROUGH THROUGH THE REGION MONDAY NIGHT THROUGH TUESDAY
MORNING. THE GFS IS SLOWER BRINGING THIS FEATURE THROUGH TUESDAY
INTO TUESDAY NIGHT. WILL LEAN TOWARD A MODEL CONSENSUS BLEND FROM
MONDAY NIGHT THROUGH TUESDAY FOR PRECIPITATION CHANCES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1140 PM CDT WED OCT 16 2013
MVFR STRATUS DECK CLEARED THE TAF SITES EARLIER IN THE EVENING.
WINDS HAVE SINCE BECOME LIGHT/VARIABLE...ESPECIALLY IN THE RIVER
VALLEYS/LOWER LAYING LOCATIONS. TEMPERATURES QUICKLY FELL TO THE DEW
POINTS ONCE THE CLOUDS CLEARED...WITH PATCHY MVFR VSBY BR ALREADY
DEVELOPING ACROSS SOUTHEAST MN INTO WESTERN WI.
LOWER LEVEL VAD WINDS FROM AREA WSR-88DS APPEAR TO BE CONTAMINATED
BY MIGRATING BIRDS...WITH 925-850MB WINDS TURNING NORTH IN THE
25-30KT RANGE. THIS NOT SUPPORTED BY 00Z RA-OBS OR RECENT MDCRS
PLANE REPORTS. REAL WINDS ABOVE THE BOUNDARY LAYER LOOK TO BE MORE
WEST AT 10-15KTS. A BIT HIGH FOR WIDESPREAD VALLEY FOG FORMATION...
BUT THE GRAY/COOL DAY FOLLOWED BY EVENING CLEARING WITH LOW TEMP/DEW
POINT SPREADS FAVORS RADIATIONAL FOG FORMATION. CONFIDENCE
INCREASING FOR BR/FG IN AT LEAST THE MS RIVER VALLEY LATE TONIGHT/
THU MORNING AND HAVE ADDED IFR CIG/VSBY IN BR TO KLSE 10-14Z.
ONCE ANY EARLY MORNING BF/FG WOULD LIFT/BURN OFF...GOOD VFR EXPECTED
THRU THU INTO THU EVENING. NEXT APPROACHING TROUGH LOOKS TO SPREAD
SOME 4K-5K FT CIGS INTO THE TAF SITES THU EVENING...WITH A FEW -SHRA
POSSIBLE AROUND KRST AFTER 03Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CDT WED OCT 16 2013
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 233 PM CDT WED OCT 16 2013
MAIN FORECAST CHALLENGES THROUGH THE SHORT TERM WILL BE... 1. CLOUD
TRENDS OVERNIGHT AND IMPACT ON FOG/FROST FORMATION...AND 2. RAIN
CHANCES FROM LATE THURSDAY AFTERNOON THROUGH THURSDAY NIGHT.
WATER VAPOR IMAGERY COUPLED WITH RAP 500MB ANALYSIS SHOWS AN
ELONGATED TROUGH EXTENDING FROM EASTERN ONTARIO CANADA...THROUGH
WI/IA/NEB AND CO. STRATUS IS HOLDING STUBBORNLY ACROSS THE AREA AS A
RESULT OF THE GENERAL CYCLONIC FLOW ALOFT. TEMPERATURES WERE ALSO
SUFFERING AS A RESULT OF THE TROUGH AND CLOUDS...CURRENTLY SITTING
IN THE 40S FOR THE MOST PART.
FOR TONIGHT...A WEAK RIDGE OF HIGH PRESSURE WILL DRIFT ACROSS THE
AREA. AS A RESULT...MODEL CONSENSUS SHOWS FAIRLY GOOD
CLEARING/THINNING OF THE STRATUS DECK FROM NORTHWEST TO SOUTHEAST
THIS EVENING WITH MOSTLY CLEAR CONDITIONS EXPECTED BY MIDNIGHT. THIS
WILL SET UP GOOD RADIATIONAL COOLING...AND WITH A RELATIVELY MOIST
LOWER BOUNDARY LAYER...PATCHY FOG IS LIKELY. IN ADDITION...
TEMPERATURES ARE EXPECTED TO DIVE INTO THE UPPER 20S/LOWER 30S ALONG
AND NORTH OF THE I-94 CORRIDOR FOR AREAS/WIDESPREAD FROST.
ELSEWHERE...LOWS TONIGHT ARE EXPECTED TO BE IN THE MID-UPPER
30S...SO CANNOT RULE OUT SOME POCKETS OF FROST. HOWEVER...
HEADLINE-ABLE FROST IS NOT EXPECTED.
WILL THEN BE WATCHING A MID-LEVEL TROUGH AND SURFACE COLD FRONT DROP
SOUTHEAST ACROSS THE AREA LATER THURSDAY AFTERNOON THROUGH THURSDAY
NIGHT. NAM/GFS SHOWING FAIRLY DECENT PV-ADVECTION IN THE 700-300MB
LAYER ASSOCIATED WITH THIS WAVE FOR A BOUT OF SCATTERED RAIN SHOWER
ACTIVITY MOVING INTO AND ACROSS THE AREA. WARM AIR ADVECTION AHEAD
OF THE MID-LEVEL WAVE/SURFACE COLD FRONT THURSDAY BRING 925MB
TEMPERATURES INTO THE 8-11C RANGE. THIS SHOULD EQUATE TO NEAR
SEASONABLE HIGHS IN THE MIDDLE 50S TO AROUND 60 DEGREES. LOWS
THURSDAY NIGHT BEHIND THE COLD FRONT ARE EXPECTED TO DROP INTO THE
UPPER 30S TO LOWER 40S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 233 PM CDT WED OCT 16 2013
MAIN CONCERN THROUGH THE LONG TERM IS UNSEASONABLY COLD UPPER LEVEL
CYCLONIC FLOW AND PERIODIC SHOTS AT PRECIPITATION.
FRIDAY APPEARS TO BE A DRY DAY AS A WEAK MID-LEVEL/SURFACE RIDGE
DRIFTS ACROSS THE AREA. HOWEVER...TEMPERATURES WILL BE SOME 5 TO 10
DEGREES BELOW NORMAL WITH HIGHS IN THE 50-55 DEGREE RANGE.
FOR SATURDAY...MODELS IN AGREEMENT IN PUSHING ANOTHER DEEP/COLD
MID-LEVEL TROUGH OVER THE REGION FOR UNSEASONABLY COOL TEMPERATURES
ALONG WITH SCATTERED RAIN SHOWER ACTIVITY GIVEN STEEP 925-700MB
LAPSE RATES. LOOK FOR HIGHS IN THE MIDDLE 40S TO THE LOWER 50S.
SATURDAY NIGHT INTO SUNDAY LOOKS DRY AT THIS POINT AS ANOTHER WEAK
RIDGE OF HIGH PRESSURE DRIFTS OVER THE REGION. PLAN ON LOWS SATURDAY
NIGHT IN THE 29-33 DEGREE RANGE WITH HIGHS SUNDAY IN THE MIDDLE 40S
TO NEAR THE 50 DEGREE MARK.
MODELS THEN DIVERGE A BIT FOR MONDAY THROUGH WEDNESDAY IN HANDLING
OF SYSTEMS RIPPLING ACROSS THE AREA IN COLD NORTHWEST FLOW ALOFT.
MODEL CONSENSUS GENERALLY YIELDS A 25-35 PERCENT PROBABILITY OF
PRECIPITATION THROUGH THE PERIOD. WILL HAVE TO WATCH PRECIPITATION
TYPE SUNDAY NIGHT INTO EARLY MONDAY MORNING / MONDAY NIGHT INTO
TUESDAY MORNING / AND TUESDAY NIGHT INTO WEDNESDAY MORNING AS
TEMPERATURES WILL BE COLD ENOUGH TO SUPPORT AT LEAST A RAIN/SNOW
MIX.
OTHERWISE...WITH DAYTIME 925MB TEMPERATURES HOVERING IN THE -1 TO
-2C RANGE...DAYTIME HIGHS ARE EXPECT TO BE SOME 10-15 DEGREES BELOW
NORMAL WITH READINGS IN THE MID 40S TO NEAR 50 MONDAY AND TUESDAY
AND IN THE LOWER AND MIDDLE 40S ON WEDNESDAY. OVERNIGHT LOWS ARE
EXPECTED TO BE IN THE LOW-MID 30S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1140 PM CDT WED OCT 16 2013
MVFR STRATUS DECK CLEARED THE TAF SITES EARLIER IN THE EVENING.
WINDS HAVE SINCE BECOME LIGHT/VARIABLE...ESPECIALLY IN THE RIVER
VALLEYS/LOWER LAYING LOCATIONS. TEMPERATURES QUICKLY FELL TO THE DEW
POINTS ONCE THE CLOUDS CLEARED...WITH PATCHY MVFR VSBY BR ALREADY
DEVELOPING ACROSS SOUTHEAST MN INTO WESTERN WI.
LOWER LEVEL VAD WINDS FROM AREA WSR-88DS APPEAR TO BE CONTAMINATED
BY MIGRATING BIRDS...WITH 925-850MB WINDS TURNING NORTH IN THE
25-30KT RANGE. THIS NOT SUPPORTED BY 00Z RA-OBS OR RECENT MDCRS
PLANE REPORTS. REAL WINDS ABOVE THE BOUNDARY LAYER LOOK TO BE MORE
WEST AT 10-15KTS. A BIT HIGH FOR WIDESPREAD VALLEY FOG FORMATION...
BUT THE GRAY/COOL DAY FOLLOWED BY EVENING CLEARING WITH LOW TEMP/DEW
POINT SPREADS FAVORS RADIATIONAL FOG FORMATION. CONFIDENCE
INCREASING FOR BR/FG IN AT LEAST THE MS RIVER VALLEY LATE TONIGHT/
THU MORNING AND HAVE ADDED IFR CIG/VSBY IN BR TO KLSE 10-14Z.
ONCE ANY EARLY MORNING BF/FG WOULD LIFT/BURN OFF...GOOD VFR EXPECTED
THRU THU INTO THU EVENING. NEXT APPROACHING TROUGH LOOKS TO SPREAD
SOME 4K-5K FT CIGS INTO THE TAF SITES THU EVENING...WITH A FEW -SHRA
POSSIBLE AROUND KRST AFTER 03Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
459 AM EDT SAT OCT 19 2013
.SYNOPSIS...
ISSUED AT 457 AM EDT SAT OCT 19 2013
AN UPPER LEVEL DISTURBANCE WILL QUICKLY SHIFT ACROSS THE REGION
TODAY...BRINGING A GOOD CHANCE FOR LIGHT RAIN AND SHOWERS TO THE
AREA. BY AFTERNOON...MANY AREAS WILL SEE AN END TO THE
PRECIPITATION WITH MAYBE SOME PEAKS OF SUNSHINE. THE EXCEPTION TO
THIS WILL BE ACROSS MUCH OF LOWER MICHIGAN INTO FAR NW INDIANA
WHERE LAKE EFFECT CLOUD COVER AND SOME SHOWER ACTIVITY IS
EXPECTED. BELOW NORMAL TEMPERATURES WILL PERSIST THROUGH THE NEXT
SEVEN TO 10 DAYS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SAT OCT 19 2013
SEVERAL FORECAST ISSUES TO CONSIDER FOR THIS PACKAGE...ALL REVOLVING
AROUND PRECIP CHANCES.
UPPER LEVEL TROUGH AXIS WAS LOCATED FROM WESTERN MINNESOTA TO
CENTRAL OKLAHOMA WITH STG WAVE QUICKLY ROUNDING THE BASE AND HEADING
NE TOWARDS THE LOWER GREAT LAKES/OHIO VALLEY. UPWARD MOTION WAS
RAPIDLY INCREASING ACROSS THE REGION IN RESPONSE TO INCREASING MID
LEVEL HGT FALLS APPROACHING 120 M/12 HRS ONCE AGAIN PASS ACROSS THE
AREA. LIGHT RAIN/DRIZZLE HAS BEEN SLOWLY EXPANDING ACROSS CENTRAL
ILLINOIS AND WAS RAPIDLY MOVING/EXPANDING NE INTO MUCH OF THE
FORECAST AREA. AS A RESULT HAVE HAD TO BUMP UP POPS DRAMATICALLY IN
MANY AREAS AND ALSO SPEED ARRIVAL/DEPARTURE TIMES. PERIODS OF
RAIN/SHOWERS WILL LIKELY IMPACT MANY SPOTS GENERALLY SE OF KNOX TO
THREE RIVERS LINE WITH HIGH LIKELY/CAT POPS WARRANTED IN THESE
AREAS. HRRR HAS HANDLED OVERALL EVOLUTION WELL OVER THE PAST SEVERAL
RUNS AND QUICKLY EXITS PRECIP BY 17Z. GRIDS NOW SHOWING THESE TRENDS
WITH QPF ON THE ORDER OF A FEW HUNDREDTHS TO MAYBE NEAR A QUARTER
INCH (SE AREAS) WITH A BRIEF LULL INTO MID AFTERNOON BEFORE FOCUS
SHIFTS TO LAKE EFFECT/ENHANCEMENT.
COLDER AIR WILL SETTLE IN QUICKLY TODAY AND TONIGHT WITH 850 MB
TEMPS DROPPING TO AROUND 0C. THIS COMBINED WITH LAKE SFC TEMPS IN
THE MID TEENS CELSIUS (ROUGHLY 17 C) WILL ALLOW FOR STRONG
INSTABILITY OVER THE LAKE AND POINTS INLAND (LK-H85 DELTA T`S AROUND
17 AND LK-H7 DELTA T`S PUSHING 30 C BY TONIGHT). DESPITE
THIS...AVAILABLE MSTR MAY BE SOMEWHAT LIMITED WITH SOUTHWARD EXTENT
INTO NW PORTIONS OF THE AREA. ALSO TRAJECTORY WILL BE MORE 230 TO
260 MUCH OF THE PERIOD WITH DEEPER CLOUD LAYER MSTR RESIDING ACROSS
N BERRIEN/NW CASS INTO REMAINDER OF WESTERN LWR MI. HAVE MAINTAINED
LIKELY POPS IN THE BERRIEN/CASS CO AREAS WITH QUICK DROP IN POPS
FURTHER EAST AND SOUTH. CHANCES WILL LINGER INTO AT LEAST THIS
EVENING AND POSSIBLY OVERNIGHT. HOWEVER...DELTA T`S WILL BEGIN TO
DECREASE SOMEWHAT AND FLOW LESS FAVORABLE FOR THE AREA FOR
ADDITIONAL PRECIP.
AWAY FROM THE LAKE AREAS...POTENTIAL DOES EXIST FOR SOME PATCHY
FROST IN MAINLY OUTLYING AREAS AS LOWS DIP INTO THE MID 30S IN MANY
AREAS. WINDS MAY REMAIN JUST STRONG ENOUGH TO KEEP FORMATION LIMITED
WITH FROST CONFINED TO HIGHER SURFACES OR FAVORED DRAINAGE AREAS.
FOR NOW WILL LEAVE MENTION OUT OF FORECAST AND DEFER TO DAY SHIFT TO
MONITOR CLEARING TRENDS AND ANTICIPATED WINDS.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 457 AM EDT SAT OCT 19 2013
SUCCINCT SHARPENING OF MID CANADA/CONUS TROF UNDERWAY WITH CURRENT
SHORTWAVE DIGGING THROUGH WESTERN GREAT LAKES WITH SUBSTANTIVE
BURGEONING BAROCLINIC LEAF SERN MO INTO CENTRAL ILLINOIS. THIS WAVE
TO RAPIDLY TRANSLATE NEWD TO SOUTHEAST ONTARIO BY LATE THIS EVENING.
BUCKLING POSITIVE HEIGHTS SUNDAY AMID PUTRID MOISTURE PROFILES AND
STRONG LOW LEVEL THERMAL PUSH INTO MID MS VLY POINTS TO FINAL DEATH
KNEEL TO PRIOR TOKEN POP MENTION FOR NWRN CWA SUN. A MORE
TIGHTLY PACKED/VIGORED UPSTREAM ENERGY LOBE NOTED IN WV IMAGERY
64N/105W OR JUST NORTH OF MAN/SASK BORDER POISED FOR CROSS
MERIDIONAL FLOW TO DEEPEN WITH MIDLVL SYSTEM DEEPENING INTO WRN
GREAT LAKES SUNDAY NIGHT INTO MONDAY. CONTD SIMILAR THEME WRT POP
COVERAGE LIMITED TO NWRN/NRN CWA IN STRONG LOW LEVEL WAA...WITH BEST
DYNAMICS SHUNTED W-NW-N OF CWA. AND BEST ALBEIT STILL TEMPERED POPS
FOR MONDAY A LA ANAFRONTAL SCENARIO IN TRAILING LOBE OF HEIGHT
FALLS. IT WILL BE THIS SYSTEMS PASSAGE THAT WILL EFFECTIVELY PUT THE
KIBOSH ON THE NOTABLY STRONG/CYCLICAL CAA/WAA LLVL PATTERN
INTERTWIXT BTWN SYSTEMS OF RECENT PAST...AS FINALLY DEEP COLD AIR
BECOMES ENTRENCHED ACROSS GRT LKS REGN. HEREAFTER...STRONG
CONCURRENCE WITH A PRIORI DISCUSSION/GRIDS AS TO INCREASED ACTIVE
LAKE ENHANCED SHRA POTNL WITH 8H/LK THERMAL DIFFERENTIALS INCREASING
TO AROUND 20C. INCREASED CONFIDENCE OF DEEPER COLD PROFILE SUPPORTS
INTRODUCING POTNL FOR LIQUID/FROZEN MIX BY THURSDAY. SOME MINOR
PROBABILISTIC CONCERN FOR FROZEN PTYPE ON WEDNESDAY...THOUGH ONE
PSBL FLY IN THE OINTMENT MAYBE HINTS OF PLAINS TO MID MS VLY CLIPPER
SYSTEM TO DIVE THRU EASTERN PERIPHERY OF BROADLY ARCHED WRN CONUS
RIDGE. THIS SCENARIO SHOULD FAVOR TEMPORARY BACKING CBL
FLOW/INCREASED IN CLOUD SHEAR. THIS ALONG WITH INITIAL WARM SUB
CLOUD REGION...ESPCLY PROXIMAL TO SRN LK MI SHOULD ALLOW FOR
MELT...LENDS TOWARD OMISSION ATTM. GRADUAL THERMAL MODERATION INTO
NEXT WEEKEND AS A TRANSITIONAL PATTERN AND/OR POSSIBLE TEMPORARY
SPLIT FLOW APPEARS FAVORED. DRYING TREND UNTIL GREATER CONFIDENCE OF
NOTEWORTHY SYSTEM POTNL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 133 AM EDT SAT OCT 19 2013
LIFT AHEAD OF SHORT WAVE MOVING TOWARDS THE REGION HAS ALREADY
ALLOWED FOR LARGE AREA OF VRY LGT RAIN/DRIZZLE TO EXPAND ACROSS MUCH
OF CENTRAL ILLINOIS. GIVEN PRESENT TRAJECTORIES HAVE OPTED TO
INCLUDE VFR MENTION OF LIGHT RAIN AT KSBN FOR A FEW HOURS OVERNIGHT
AND THEN IMPROVING CONDITIONS. WILL MONITOR UPSTREAM TRENDS AS
TROUGH AXIS TO THE WEST MAY SHIFT THROUGH FAST ENOUGH TO PUSH PRECIP
EAST OR LINGER LONG ENOUGH IN THE WEST TO ALLOW FOR MORE EXPANSIVE
LIGHT RAIN. AT KFWA...LONGER PERIOD OF LGT RAIN MAY OCCUR BUT STILL
MINIMAL OVERALL IMPACT WITH EXCURSION INTO MVFR RANGE POSSIBLE
TOWARDS 12Z.
WAVE MOVES AWAY BY EARLY AFTERNOON WITH SW/W FLOW SETTING UP ACROSS
THE LAKES TO ALLOW FOR SOME LAKE ENHANCEMENT CLOUDS/LIGHT SHOWERS.
THIS SHOULD REMAIN GENERALLY NORTH OF KSBN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR LMZ043-046.
&&
$$
SYNOPSIS...FISHER
SHORT TERM...FISHER
LONG TERM...MURPHY
AVIATION...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1148 PM CDT FRI OCT 18 2013
.SHORT TERM /TONIGHT/...
ISSUED AT 323 PM CDT FRI OCT 18 2013
IN A NEAR REPEAT OF YESTERDAY AFTERNOONS FORECAST...ANOTHER 500 MB
SHORTWAVE EMBEDDED IN THE MEAN CENTRAL NORTH AMERICAN LONGWAVE
TROUGH IS POISED TO TRACK THROUGH IOWA LATE TONIGHT AND INTO
TOMORROW MORNING. AS WITH ITS PREDECESSOR...FORCING AND MOISTURE
WILL BE SPARSE AND ANY RAIN SHOWERS OVERNIGHT WILL BE CONFINED TO
NORTHERN IOWA. THIS SCENARIO WAS HANDLED WELL BY THE HIGH RES WRF
ARW AND RAP...THUS USED A BLEND OF THESE TWO MODELS FOR THE
PRECIPITATION FORECAST. A SECOND IMPULSE/VORT MAX SLIDES DOWN THE
REAR FLANK OF THE LONGWAVE TROUGH IN WESTERN MINNESOTA AND NORTHWEST
IOWA TOWARDS THE END OF THE PERIOD. MOISTURE PROFILES ARE SLIGHTLY
MORE CONDUCIVE FOR RAINFALL AND HAVE INCREASED POPS ACCORDINGLY IN
THE NORTHWEST TOWARDS 12Z SAT.
290 TO 300K ISENTROPIC ACCENT GENERATED A BAND RAIN AND SNOW ACROSS
KANSAS AND NORTHERN MISSOURI TODAY. THE ASSOCIATED SHIELD OF
CIRROSTRATUS AND ALTOSTRATUS CLOUDS PROPAGATED INTO IOWA THIS
MORNING AND PUT A DAMPER ON HIGHS ACROSS THE SOUTHERN HALF OF THE
CWA. THIS SYSTEM WILL PULL ENE THIS EVENING AS THE UPPER LEVEL
TROUGH DIGS INTO THE CENTRAL PLAINS. THERE IS SOME UNCERTAINTY WITH
HOW MUCH OF THE CLOUD COVER OVER SOUTHERN IOWA WILL CLEAR OUT
BETWEEN THE 06 AND 12Z TIME FRAME. BOTH THE NAM AND RAP SOUNDINGS
HINT AT SOME CLEARING TOWARDS MORNING...SO LOWERED MIN TEMPS IN THE
NISH VALLEY AND OTHER PORTIONS OF SOUTHWEST IOWA.
.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 323 PM CDT FRI OCT 18 2013
BROAD LONG WAVE TROF WILL REMAIN ENTRENCHED ACROSS THE EASTERN
HALF OF THE UNITED STATES DURING THIS FORECAST PERIOD.
THEREFORE...BELOW NORMAL TEMPERATURES ARE EXPECTED FOR MUCH OF THE
NEXT WEEK. THERE WILL ALSO BE THREATS FOR LIGHT PRECIPITATION FROM
TIME TO TIME AS SYSTEMS PASS THROUGH THE STRONG NORTHWEST FLOW.
FIRST WEAK SYSTEM GLANCES THE NORTH TOMORROW MORNING ALTHOUGH THE
BULK OF THE FORCING WILL REMAIN NORTH OF IOWA. HAVE CONTINUED THE
THREAT FOR SOME ISOLATED/SCATTERED SHOWERS IN THE MORNING BUT WITH
SUBSIDENCE ARRIVING BY AFTERNOON...SHOULD SEE ANY ACTIVITY QUICKLY
ENDING. WARM ADVECTION INTO SUNDAY WILL MAKE IT THE WARMEST DAY
OVER THE NEXT WEEK. THE WARMER AIR IS AHEAD OF THE NEXT SYSTEM
DIVING SOUTHEAST INTO THE REGION. ONCE AGAIN...THE FORCING
ASSOCIATED WITH THIS SYSTEM REMAINS NORTH OF IOWA WITH ANY PCPN
THREAT RESIDING NEAR THE MINNESOTA BORDER. STRONG COLD ADVECTION
WILL ARRIVE BY LATE IN THE DAY WITH A MUCH COLDER AIRMASS BECOMING
ESTABLISHED ACROSS THE STATE ON MONDAY. ONE FINAL SYSTEM DROPS
SOUTHEAST TOWARD THE STATE LATE MONDAY NIGHT INTO TUESDAY. THE
EURO IS MOST AGGRESSIVE WITH SATURATION AND LIFT ACROSS IOWA WITH
A FEW TENTHS OF PCPN ON TUESDAY. GIVEN RELATIVELY COLD THERMAL
PROFILES DURING THIS EVENT...WOULDNT BE SURPRISED TO SEE SOME SNOW
MIXED WITH RAIN WITH STRONG DYNAMICAL COOLING SUGGESTED BY THE
LIFT. THE COLDER AIRMASS WILL THEN REMAIN ESSENTIALLY IN PLACE
THROUGH THE END OF NEXT WEEK. THIS SHOULD EFFECTIVELY END THE
GROWING SEASON ACROSS CENTRAL IOWA FOR THOSE LOCATIONS THAT HAVENT
ALREADY SEEN A FREEZE.
&&
.AVIATION...19/06Z
ISSUED AT 1148 PM CDT FRI OCT 18 2013
VFR CONDITIONS EXPECTED TO MAINTAIN THROUGH 12Z. A FEW SHOWERS AND
AREAS OF MVFR CIGS ARE POSSIBLE OVER THE NORTH AND NORTHEAST
SATURDAY MORNING INTO THE EARLY AFTERNOON. THE CIGS WILL GRADUALLY
RISE AND BE PRIMARILY VFR BY THE AFTERNOON. THE WIND WILL BECOME
BREEZY FROM THE WEST DURING THE DAY BEFORE DIMINISHING BY THE
EVENING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SKOW
LONG TERM...COGIL
AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS GAYLORD MI
236 AM EDT SAT OCT 19 2013
.SYNOPSIS...
ISSUED AT 233 AM EDT SAT OCT 19 2013
AN ACTIVE AND CHILLY PATTERN WILL REMAIN ACROSS THE GREAT LAKES
RIGHT THROUGH NEXT WEEK. THE MOST SIGNIFICANT LOW PRESSURE SYSTEM IN
THE NEAR FUTURE WILL MOVE SOUTHEAST FROM CENTRAL CANADA THIS
WEEKEND...REACHING LAKE SUPERIOR BY MONDAY MORNING. THE COLDEST AIR
OF THE FALL SEASON SO FAR WILL ENTER THE REGION BEHIND THE LOW
PRESSURE SYSTEM. TEMPERATURES MAY GET COLD ENOUGH NEXT WEEK TO BRING
THE FIRST SNOWFALL OF THE SEASON...ESPECIALLY TO THE INTERIOR
HIGHLANDS OF NORTHERN LOWER MICHIGAN.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 233 AM EDT SAT OCT 19 2013
FIRST ROUND OF A STEP DOWN PROCESS TO A MUCH COOLER WEATHER REGIME
FIRMLY IN CONTROL OF OUR WEATHER AT THIS EARLY HOUR...COURTESY OF
OVERHEAD TROUGHING IN A REMARKABLY AMPLIFIED NOAM FLOW REGIME.
LATEST RAP HIGH RES ANALYSIS CONFIRMS...WITH H8 TEMPERATURES DIPPING
TO SUB 0C LEVELS ACROSS THE NORTHWEST HALF OF THE AREA. DESPITE
OVERHEAD TROUGHING...MID LEVEL SYNOPTIC DYNAMICS RATHER
NEGLIGIBLE...WITH FIRST WAVE (RESPONSIBLE FOR YESTERDAY`S CONVECTIVE
ACTIVITY) OFF TO OUR NORTHEAST...WITH STRONGER CORE OF MID LEVEL
SUPPORT PINWHEELING IN BASE OF TROUGH AXIS WELL TO OUR SOUTHWEST.
LOW LEVEL FEATURES SOMEWHAT MORE FOCUSED...WITH SURFACE TROUGHING
EXTENDING NORTHEAST TO SOUTHWEST...ESSENTIALLY BISECTING NORTHERN
LOWER MICHIGAN...WITH NOTED H8 TROUGHING JUST OFFSET TO THE WEST OF
THIS SURFACE FRONT. COMBINATION OF ATTENDANT FORCED LOW LEVEL
CONVERGENCE AND FAVORABLE LAKE PROCESSES CONTINUE TO KICK OFF
POCKETS OF SHOWERS...SOME OF WHICH HAVE BEEN LOCALLY HEAVY...
ESPECIALLY ALONG THE LAKE MICHIGAN SHORELINE. SURFACE TEMPERATURES
STILL IN THE 40S AND SURFACE BASED MELTING LAYER AT OR ABOVE 2 KFT
LEADING TO ALL LIQUID SHOWERS. SHORT TERM FORECAST CONCERNS REMAIN
CENTERED ON ADDITIONAL SHOWER POTENTIAL RIGHT THROUGH TONIGHT...AS
WELL AS ADDRESSING THUNDER AND WATERSPOUT CHANCES INTO THIS
EVENING.
REALLY KINDA A LOW CONFIDENCE ENDEAVOR ON FORECASTING SHOWER
EVOLUTION TODAY. NO DOUBT THERMODYNAMIC PROFILES REMAIN VERY
SUPPORTIVE FOR ADDITIONAL LAKE PROCESSES...WITH H8 TEMPERATURES
HOVERING AROUND -2C AND LAKE INDUCED EQUILIBRIUM LEVELS UP AND OVER
20 KFT (LAKE INDUCED CAPE OF AROUND 1.0 J/KG). THAT SAID...
KINEMATICS AND OVERALL SYNOPTIC BACKGROUND SUPPORT NOT NEARLY AS
FAVORABLE FOR WIDESPREAD ORGANIZED LAKE INDUCED SHOWERS. WIND FIELDS
RIGHT UP THROUGH 15 KFT REMAIN RATHER LIGHT AND DISORGANIZED...WITH
LOW LEVEL WINDS STEADILY BACKING THROUGH THE DAY AHEAD OF NEXT
APPROACHING SHORTWAVE TROUGH AND ATTENDANT SURFACE REFLECTION. MAIN
CORE OF ENERGY CURRENTLY TIED TO BASE OF TROUGH AXIS LOOKS TO SLIDE
JUST OFF TO OUR SOUTHEAST...LIKELY NOT HAVING A SIGNIFICANT EFFECT
ON LAKE PROCESS MORPHOLOGY (MAY INCREASE THE ODDS FOR MORE FOCUSED
SHOWERS ACROSS NORTHEAST LOWER THIS MORNING). COMBINE ABOVE WITH
TERRESTRIAL CAPE DEVELOPMENT SIMPLY OVERWHELMING LIMITED CBL
SHEAR...RESULTING IN A DEFINITE CELLULAR COMPONENT TO LAKE SHOWER
ACTIVITY...AND ONE CAN SEE WHY SHOWER COVERAGE REMAINS QUITE
PROBLEMATIC TODAY. SHOWERS WILL NO DOUBT CONTINUE...BUT WILL CONFINE
BETTER COVERAGE CLOSER TO THE LAKE MICHIGAN SHORELINE...WITH BELIEF
OVERALL AREAL COVERAGE WILL DISSIPATE AS THEY MOVE INLAND. SURFACE
BASED CAPE AND H5 TEMPERATURES DIPPING TO -30C WILL DEFINITELY AID
IN AN OVERLAND SHOWER COMPONENT...AND MUCH LIKE YESTERDAY...AN
ISOLATED THUNDERSTORM OR TWO. DEEP MOIST CONVECTION IN SUCH A COLD
ENVIRONMENT WILL DEFINITELY SUPPORT THE THREAT OF BRIEF GRAUPEL
SHOWERS UNDER THE HEAVIER PRECIP CORES. HIGHS TODAY WILL RUN A FEW
DEGREES BELOW NORMAL...WITH AFTERNOON READINGS IN THE 40S AND LOWER
50S.
LAKE PROCESSES LIKELY TO GET A BOOST HEADING INTO THIS EVENING AS
WEAK WAVE AND SURFACE TROUGH/ATTENDANT CORE OF LOW LEVEL CONVERGENCE
CROSS LAKE MICHIGAN. MAY SEE SOME PRETTY HEAVY SHOWERS ALONG THIS
TROUGH AS IT PUSHES ONSHORE...WITH SHOWER COVERAGE ONCE AGAIN
DISSIPATING AS THEY PUSH INLAND. GIVEN MAINTENANCE OF DEEP EQL/S AND
GOOD OVER-WATER CAPE...WILL CONTINUE THUNDER MENTION INTO THIS
EVENING OVER AND NEAR LAKE MICHIGAN. LAKE ENHANCEMENT/SHOWER
COVERAGE BOTH EXPECTED TO DISSIPATE OVERNIGHT AS POST-WAVE
SUBSIDENCE REGIME SPREADS ACROSS AND MOISTURE PROFILES BEGIN TO
THIN.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 233 AM EDT SAT OCT 19 2013
UPPER FLOW IS ANCHORED BY RIDGING ALONG OR JUST OFF THE WEST
COAST...AND BROAD RIDGING IN THE CENTRAL ATLANTIC. IN BETWEEN...
TROFFING REIGNS SUPREME OVER CENTRAL CANADA AND ADJOINING PARTS OF
THE US. THIS PATTERN WILL KEEP NORTHERN MI WX COOL AND UNSETTLED FOR
QUITE SOME TIME. THE REAL FUN ARRIVES TOWARD THE EARLY PART OF NEXT
WEEK...AS THE UPPER LOW NOW OVER NW HUDSON BAY DROPS SOUTHWARD INTO
THE NORTHERN GREAT LAKES. PRECIP TRENDS ARE THE MAIN CONCERN THRU
THE FORECAST.
SUNDAY LOOKS LIKE A /RELATIVE/ LULL IN THE SHOWER ACTIVITY. AS THE
UPPER TROF OVER NORTHERN MI TODAY DEPARTS THE EASTERN LAKES...AND AS
THE NEXT LOW DROPS SOUTH ACROSS MANITOBA...A BIT OF SHORTWAVE
RIDGING GETS PUMPED UP INTO THE CENTRAL/NORTHERN LAKES. SUBTLE
SURFACE RIDGING POKES NORTH TOWARD LAKE HURON AT MIDDAY...THEN MOVES
EAST AS RETURN FLOW RAMPS UP LATE IN THE DAY. THOUGH DEEPER DRYING
IS ARRIVING (850-700MB RH LOWERING BELOW 60 PERCENT)...WITH 850MB
TEMPS -2 TO -3C...WOULD STILL EXPECT AT LEAST SCT SHRA IN THE
MORNING IN W TO WSW FLOW AREAS (MAINLY NW LOWER). MAY CATCH A BIT OF
A PRECIP BREAK MIDDAY TO MID AFTERNOON. AFTER THAT...THE NAM MAY BE
OVERDONE IN DEVELOPING A 45KT 850MB JET PUNCHING UP THE SPINE OF
CENTRAL/SOUTHERN LAKE MI. BUT INCREASING RETURN FLOW WARRANTS A
CHANCE OF SHRA RETURNING VERY LATE IN THE DAY IN SOME WESTERN
SECTIONS. MAX TEMPS NEAR 50 TO THE LOWER 50S.
SUN NIGHT/MONDAY...500MB LOW WILL CONTINUE TO DROP TOWARD INTL FALLS
BY MONDAY MORNING...THEN PIVOT TOWARD CENTRAL LAKE SUPERIOR BY
EVENING. THE ASSOCIATED SURFACE LOW WILL DEEPEN TO AROUND 998MB OVER
CENTRAL SUPERIOR BY MORNING MORNING...THEN FILL A BIT AND ELONGATE
TOWARD THE ENE DURING THE DAY.
ON SUNDAY NIGHT...RAIN WILL SPREAD ENE-WARD FROM NORTHERN/CENTRAL
WI...INITIALLY MAINLY NORTH OF A WARM FRONT THAT LIFTS INTO FAR
NORTHERN LOWER MI BY 06Z. THAT FRONT LIFTS ACROSS EASTERN UPPER MI
OVERNIGHT...BUT THE COLD FRONT IS RIGHT BEHIND...CROSSING MOST OF
THE FORECAST AREA FROM WEST TO EAST. THIS BOUNDARY MAY STILL BE
HANGING AROUND EXTREME EASTERN SECTIONS (OSC-APN-DRUMMOND) AT 12Z.
POPS WILL BE HIGHEST NORTH OF A TVC-APN LINE...WHERE THE LOW LEVEL
JET (850MB WINDS PUSHING 50-55KT AT 03Z) PUNCHES ACROSS THE
ADVANCING WARM FRONT. POPS DIMINISH TO CHANCE IN THE FAR SE.
MONDAY IS A DAY DOMINATED BY MID/UPPER-LEVEL DRY SLOTTING...AS THE
WARM CONVEYOR BELT RACES EAST...AND WRAPAROUND MOISTURE REMAINS BACK
ALONG THE WESTERN AND NORTHERN SHORES OF SUPERIOR. HOWEVER...A
SUBSTANTIAL QUANTITY OF COLD AIR WILL BE PUSHING IN AS THE DAY
PROCEEDS. 850MB TEMPS WILL BE IN THE PROCESS OF SLIDING BACK TO OR
BELOW 0C BY 12Z...READINGS CLOSER TO -6C ARE PROGGED BY SUNSET. THE
INCREASING INSTABILITY SHOULD FIGHT OFF THE DRIER AIR ALOFT...AND
SUPPORT AT LEAST SOME SHRA DOWNWIND OF THE LAKES. WHERE EXACTLY THAT
IT IS STILL CONJECTURE...AS DIFFERENT ORIENTATIONS OF THE SURFACE
LOW TO OUR RESULTS IN DIFFERENT FETCHES (FROM W TO SW). WILL SPLIT
THE DIFFERENCE FOR NOW.
MIN TEMPS NEAR 40F TO THE LOWER 40S. MAX TEMPS ONLY 5F WARMER THAN
THAT WEST...10F EAST...WITH FALLING READINGS IN THE PM. BRISK/WINDY
ON MONDAY.
REST OF THE FORECAST...NO MAJOR CHANGES TO THE EXTENDED.
UNSEASONABLY COOL WX WILL CONTINUE. THOUGH THE UPPER LOW ITSELF WILL
LIFT OUT INTO QUEBEC ON TUESDAY/WEDNESDAY...PLENTY OF TROFFING GETS
LEFT BEHIND. OCCASIONAL REINFORCING SHORTWAVES FROM THE NNW WILL
REINFORCE THE TROFFING...AND THE COLDER AIR AT LOW LEVELS. LAKE
EFFECT SHOWERS WILL CONTINUE DOWNWIND OF THE LAKES...AND MAINTAINED
LIKELY POPS IN THE CLASSIC SNOWBELTS. SPEAKING OF SNOW...PRECIP WILL
GET MIXY TO SNOWY AT TIMES...ESPECIALLY AT NIGHT/MORNING AND
ESPECIALLY IN THE HIGH TERRAIN OF NORTHERN LOWER. THOUGH QUITE
UNCERTAIN WHETHER THIS WILL EVER RISE TO THE LEVEL OF A WINTER WX
HEADLINE...THE MENTION OF THE FIRST SNOW OF THE SEASON PRESENTLY IN
THE HAZ WX OUTLOOK IS REASONABLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 120 AM EDT SAT OCT 19 2013
LOW VFR/HIGH MVFR CIGS WILL PERSIST ACROSS MOST OF NRN LWR MICHIGAN
THRU SATURDAY NIGHT AS NMRS LAKE ENHANCED RAIN SHOWERS CONTINUE TO
STREAM INTO THE REGION. THE EXCEPTION WILL BE APN WHERE A TEMPORARY
DIMINISH IN CLOUD COVER TONIGHT HAS ALLOWED FOR SOME FOG DEVELOPMENT
AND IFR CONDITIONS. SOME FOG WILL PERSIST IN THIS AREA THRU EARLY TO
MID MORNING DESPITE INCREASING CLOUDS LATE TONIGHT. NW LWR MICHIGAN
(PLN/TVC/MBL) WILL SEE THE MOST FREQUENT SHOWER ACTIVITY AS W/SW LOW
LEVEL FLOW THIS EVENING SHIFTS TO THE NW OVERNIGHT AS A TROUGH
SWINGS THRU MICHIGAN. LOW LEVEL WINDS WILL BACK TO THE WEST BY
MIDDAY SATURDAY AHEAD OF THE NEXT WAVE OF LOW PRESSURE AS A DEEP 500
MB TROUGH DIGS INTO THE UPPER MISSISSIPPI VALLEY.
&&
.MARINE...
ISSUED AT 233 AM EDT SAT OCT 19 2013
BIG STORY REMAINS ISOLATED WATERSPOUT POTENTIAL TODAY INTO
THIS EVENING. COMBINATION OF UNSEASONABLY CHILLY AIRMASS/WEAK
PARTIALLY LAKE-DRIVEN SURFACE TROUGH/AND DEEP CONVECTION DEFINITELY
SUPPORT THIS POTENTIAL. PRIMARY THREAT IS EXPECTED ACROSS THE WATERS
OF LAKE MICHIGAN AND LAKE HURON...WITH THE THREAT ENDING OVERNIGHT
AS THE SURFACE TROUGH PASSES. OTHERWISE...MARGINALLY GUSTY GENERAL
WEST FLOW TODAY...ALTHOUGH BOTH WINDS AND WAVES LOOK TO REMAIN BELOW
SCA CRITERIA. WINDS BEGIN TO PICK UP OUT OF THE SOUTHEAST
SUNDAY...BECOMING QUITE GUSTY SUNDAY NIGHT. WINDS VEER SOUTHWEST ON
MONDAY BEHIND PASSAGE OF A STRONG COLD FRONT. HEADLINES WILL
EVENTUALLY BE NEED FOR THE WATERS LATER SUNDAY RIGHT THROUGH MONDAY
(AND LIKELY BEYOND). MAY EVEN SEE GALE CONDITIONS ON NORTHERN LAKE
MICHIGAN ON MONDAY AS STRONG LOW PRESSURE PULLS UP ACROSS LAKE
SUPERIOR.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SYNOPSIS...JZ
SHORT TERM...MB
LONG TERM...JZ
AVIATION...MR
MARINE...MB
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1201 AM CDT Sat Oct 19 2013
.UPDATE...
Issued at 949 PM CDT FRI OCT 18 2013
The going forecast remains on track and only minor changes were made
to temperatures and PoPs to keep up with trends in each. Potential
remains for some patchy frost tonight but there are a few things
that may hinder development despite temperatures falling into the
32-35 degree range across most of the area. The biggest is that it
looks like winds will not be calm and generally be around 5 mph or
so, with the exception of some very sheltered areas. The other is
that there is some uncertainty with how much cloud cover will be
present in the area. Some recent runs of short-term models including
the RAP and HRRR start to develop and/or move lower clouds back into
the area late tonight. Latest fog imagery is showing an area of IFR
stratus forming over eastern KS as the higher level clouds move out.
Short-range models drift this area east through overnight,
encompassing most of western Missouri through the better part of the
overnight. These two factors negatively impact the radiational
cooling potential and thus potential for frost. Will continue to
monitor trends but at this time widespread frost does not seem
likely.
&&
.SHORT TERM...(This Evening through Sunday Night)
Issued at 331 PM CDT FRI OCT 18 2013
For this evening, the main concern will be moderate rain moving
through the southern two thirds of the forecast area in advance of a
southeastward moving shortwave trough. A dry boundary layer and cold
temperatures aloft have allowed a few pellets of sleet to mix with
rain especially as the column initially saturates, and has also
allowed a few flakes of snow to mix with the lighter rain on the
back side of the precipitation shield. Rainfall amounts should be
around a few tenths to a quarter of an inch, and no accumulation of
wintry precipitation is expected. As frontogenesis weakens late this
afternoon into the early evening, precipitation should lighten
considerably and may start to break up a bit as it heads southeast.
After the precipitation clears out during the late evening to early
overnight hours, temperatures and frost potential will be the main
concern. The degree of clearing will be uncertain with additional
clouds working down across Iowa and portions of northern Missouri,
and non-zero surface winds will also make cooling of the ground
layer a bit more difficult, so have held off on a frost advisory for
now. However, temperatures will not have to fall far to get into the
lower to mid 30s since readings have fallen into the upper 30s
across many areas currently experiencing precipitation, so some
precaution will be needed with sensitive vegetation tonight.
Temperatures will slowly recover on Saturday, then will be much
warmer on Sunday as breezy west winds and sunshine help highs climb
into the upper 60s to even lower 70s. Lows should not be a concern
on Sunday or Monday mornings, with better moisture and southerly
winds helping temperatures stay in the upper 30s to mid 40s both
nights. No additional precipitation is expected through Sunday night.
.LONG TERM...(Monday through Friday)
Issued at 349 PM CDT FRI OCT 18 2013
Medium range models maintain a cold pattern during most of the
period as the mean upper trough over the eastern half of the nation
gradually shifts east. A couple of fast moving clipper type systems
are expected to zip down the back side of the upper trough with the
initial one possibly affecting the CWA on Tuesday. The 12z GFS came
into agreement with the 00z ECMWF but now the 12z ECMWF tracks the
clipper further east. Enough uncertainty due to model waffling that
30-40% PoPs are high enough. Cold air advection through Monday night
in previous forecasts called into the possibility of freezing
temperatures is somewhat mitigated due to the expected increase in
cloud cover. So, have raised overnight lows for Monday night.
Latest ECMWF shows stronger cold air advection behind Tuesday system
for Wednesday but believe that is overdone. Nonetheless, the
overriding theme from Wednesday on is well below average
temperatures. A continued northerly component of the boundary layer
winds will funnel the shallow cold air from the Canadian provinces
southward despite rising heights aloft.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1155 PM CDT FRI OCT 18 2013
Low IFR stratus has expanded over eastern Kansas and western
Missouri. This is eroding from the west but it looks to be affecting
the terminals through the overnight hours. Have persisted the IFR
ceilings through about 12Z. Some model guidance suggest ceilings
lifting/moving away earlier. But the latest short-range models
persist IFR ceilings through sunrise over far western Missouri.
Confidence is only medium on the timing of the ending of the IFR
conditions. Once ceilings lift, in the morning, VFR conditions
should prevail with winds becoming gusty from west- northwest. Winds
will taper off towards sunset with skies becoming clear.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...CDB
SHORT TERM...Laflin
LONG TERM...MJ
AVIATION...CDB
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
252 AM EDT SAT OCT 19 2013
.SYNOPSIS...
A WAVE OF LOW PRESSURE WILL FORM ALONG A STATIONARY FRONT OFFSHORE
AND MOVE ALONG THE COAST TONIGHT AND OFF TO THE NORTHEAST
SATURDAY. A SECONDARY COLD FRONT WILL PUSH THROUGH THE AREA
SATURDAY NIGHT. HIGH PRESSURE WILL PASS THROUGH SUNDAY AND MONDAY.
ANOTHER COLD FRONT WILL PUSH THROUGH TUESDAY NIGHT. HIGH PRESSURE
WILL BUILD IN FROM THE NORTHWEST LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF MIDNIGHT...LATEST RADAR IMAGERY SHOWING CONVECTIVE SHOWERS
INC IN COVERAGE...AND BANDED STRUCTURE OF THE PRECIP INDICATE
FGEN/OMEGA INC IN THE LOW/MID LEVELS PER LATEST RUC ANALYSIS. HAVE
CATEGORICAL POPS ACROSS COASTAL AREAS...WITH LIKELY POPS FOR THE
COASTAL PLAIN. HAVE CONTINUED MENTION OF SCT THUNDER WITH DECENT
INSTABILITY DEVELOPING OVERNIGHT EAST OF LOW TRACK ALONG THE HWY
17 CORRIDOR. QPF WILL RANGE A QUARTER TO HALF AN INCH OVERNIGHT
THOUGH LOCALLY HIGHER AMOUNTS WILL FALL WITH EMBEDDED
THUNDERSTORMS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TODAY/...
AS OF 3 PM FRI...AREA OF LOW PRESSURE WILL MOVE OFF TO THE
NORTHEAST DURING MIDDAY. CONTINUED LIKELY POPS THROUGH THE FIRST
HALF OF THE DAY...THEN TAPERED OFF TO CHANCE MAINLY WEST OF
HIGHWAY 17 IN THE AFTERNOON. THICKNESSES AT 18Z SHOW LITTLE CHANGE
FROM THIS AFTERNOON SO NOT MUCH CHANGE IN FORECAST HIGH TEMPS.
EXPECTING LOWER 70S NORTHWEST TO MID 70S SOUTHEAST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
UPPER TROUGH WILL SHIFT EAST OVER EASTERN CANADA AND NEW ENGLAND
WHILE THE COLD FRONT AND ASSOCIATED PRECIP PUSH OFF THE EASTERN
NC COAST EARLY SUNDAY MORNING. MODEST CAA BEHIND THE FRONT WILL
KEEP HIGH TEMPS AROUND 70F SUNDAY AS A SURFACE RIDGE SHIFTS EAST
OFF THE MID-ATLANTIC COAST LATE IN THE DAY. STRONG SW GRADIENT
ALOFT WILL PERSIST THROUGH TUES DUE TO BROAD HIGH HOLDING STRONG
OVER THE WESTERN ATLANTIC OCEAN AND LOW PRESSURE DIGGING SOUTH
THROUGH THE WESTERN GREAT LAKES. THE REGION SHOULD REMAIN DRY
THROUGH MONDAY WITH FRONT STALLING OFFSHORE. AN AREA OF LOW
PRESSURE WILL FORM ALONG THE STALLED BOUNDARY MON NIGHT INTO TUES
AND PUSH NE NEAR THE EASTERN NC COAST...AND THUS HAVE CONTINUED
PREVIOUS TREND OF HIGH CHANCE POPS EAST TAPERING BACK TO LOW CHANCE
DEEP INLAND. A SHORTWAVE IN MEAN SE FLOW ALOFT OVER THE CENTRAL
CONUS WILL ROTATE AROUND THE BASE OF THE POSITIVELY-TITLED UPPER
TROUGH TOWARDS EASTERN NC TUES NIGHT INTO WED...PUSHING A SURFACE
FRONT THROUGH EASTERN NC WED NIGHT WITH MUCH COOLER THAN NORMAL
TEMPS EXPECTED FOR LATE WEEK. WITH THE CONTINUING COLD AIR
INFILTRATING THE AREA, TEMPERATURES WILL SHOW A STEADY DECLINE
LATE IN THE WEEK WITH HIGHS WED UPPER 60S TRENDING COOLER TOWARD
THE LOWER 60S BY FRIDAY. LOWS AT NIGHT FOR INLAND AREAS WILL BE
QUITE COOL WITH LOW 40S WED NIGHT TRENDING TOWARD THE UPPER OR
POSSIBLY EVEN MID 30S LATE IN THE WEEK DUE TO HIGH PRESSURE AT
THE SURFACE WITH AN OVERALL DRY COLUMN SHOULD ALLOWING FOR
EXCELLENT RADIATIONAL COOLING.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH SATURDAY/...
AS OF 650 PM FRI...WEAK LOW PRESSURE WILL MOVE NORTHEAST ALONG A
FRONT STALLED JUT OFF OF THE NC COAST TONIGHT AND SATURDAY. AS THE
LOW APPROACHES LATE THIS EVENING WIDESPREAD RAIN IS EXPECTED TO
DEVELOP OVER EASTERN NC TAPERING OFF SATURDAY. WIDESPREAD PRED
MVFR CEILINGS CONTINUE EARLY THIS EVENING...THEN A PERIOD OF IFR
CONDITIONS LIKELY TO DEVELOP OVERNIGHT AS WIDESPREAD RAIN DEVELOPS.
IFR CONDITIONS ARE EXPECTED TO LINGER INTO SATURDAY MORNING IN FOG
AND STRATUS. THE LOW CLOUDS AND FOG WILL DIMINISH BY SATURDAY
AFTERNOON WITH CEILINGS LIFTING THROUGH MVFR WITH SOME BRIEF VFR
CONDITIONS POSSIBLY DEVELOPING BY MID AFTERNOON.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MAINLY VFR SUN AND MON AS HIGH PRESSURE CROSSES THE REGION. SOME
SCATTERED SHOWERS POSSIBLE TUES INTO TUES NIGHT AS AN AREA OF LOW
PRESSURE FORMS ALONG THE STALLED BOUNDARY OFF THE COAST AND PUSHES
NE OFF THE COAST THROUGH TUES NIGHT. SOME REDUCED CEILINGS AND
VSBYS ARE POSSIBLE...ESPECIALLY FOR EWN/OAJ CLOSER THE COAST.
RETURN TO VFR EXPECTED WED.
&&
.MARINE...
SHORT TERM /THROUGH SATURDAY/...
AS OF 1015 PM FRI...MARINE FORECAST IN GREAT SHAPE...NO CHANGES
NEEDED AT THIS TIME. THE LATEST BUOY OBS CONTINUE TO SHOW NE/E
WINDS 5-15 KT AND SEAS 2-4 FT. THE AREA OF LOW PRESSURE CONTINUES
TO DEVELOP ALONG A STATIONARY BOUNDARY OVER COASTAL SC. THIS LOW
PRESSURE WILL MOVE ALONG THE COAST OVERNIGHT AND IS EXPECTED TO
LIFT TO THE NE BY TOMORROW AFTERNOON. WINDS WILL BE VARIABLE
OVERNIGHT...VEERING INTO SATURDAY MORNING...EVENTUALLY BECOMING
WEST SOUTHWEST THROUGHOUT SATURDAY AFTERNOON. WIND SPEEDS AND SEAS
WILL REMAIN BELOW SMALL CRAFT LEVELS. WIDESPREAD RAIN EXPECTED
FROM LATE TONIGHT INTO MOST OF SATURDAY. SCATTERED THUNDER
POSSIBLE TONIGHT AND ISOLATED THUNDER POSSIBLE SATURDAY.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
A COLD FRONT CROSSES THE WATERS EARLY SUN MORNING WITH A BRIEF
SURGE OF NW TO N WINDS OF 15 TO 20 KTS. WINDS WILL QUICKLY SUBSIDE
TO 10 TO 15 KTS LATER SUN AND BECOME MORE NE AS HIGH PRES BUILDS
TO THE N. MAINLY NE WINDS 5 TO 15 KTS SUN NIGHT AND MON AS HIGH
PRES SLIDES OFFSHORE TO THE N. COLD FRONT WILL APPROACH FROM THE W
TUES WITH A WEAK WAVE DEVELOPING NEAR THE COAST AHEAD OF FRONT.
UNCERTAINTY REMAINS FOR WINDS/SEAS TUES/WED BUT FOR NOW LOOKS LIKE
SPEEDS WILL REMAIN AT OR BELOW 15KTS.
SEAS WILL BUILD TO 3 TO 5 FT CENTRAL AND NORTHERN WATERS EARLY
SUN IN WAKE OF FRONT. SEAS WILL SUBSIDE TO 2 TO 3 FT SUN NIGHT AND
CONT IN THAT RANGE INTO TUES. SEAS BUILD 2-4 FT TUES NIGHT THEN
3-5 FT...MAINLY FOR THE CENTRAL AND NORTHERN WATERS DUE TO
MODERATE NORTHERLY SURGE WED.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HSA
NEAR TERM...HSA/TL/BM
SHORT TERM...HSA
LONG TERM...BTC/DAG
AVIATION...BTC/HSA/CQD/DAG
MARINE...BTC/HSA/CQD/DAG/BM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
140 AM EDT SAT OCT 19 2013
.SYNOPSIS...
A WEAK SURFACE WAVE OF LOW PRESSURE WILL TRACK NORTH ALONG A STALLED
FRONTAL ZONE DRAPED ACROSS THE SOUTHEAST...NC COAST THIS MORNING.
A STRONGER SECONDARY COLD FRONT WILL CROSS THE REGION LATE THIS
EVENING. WEAK HIGH PRESSURE WILL BUILD OVER THE AREA THROUGH EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 915 PM FRIDAY...
MAIN FORECAST CHALLENGE TONIGHT INTO SATURDAY IS HOW FAR WEST-NW
WILL THE THREAT FOR PATCHY LIGHT RAIN EXPAND ACROSS CENTRAL NC.
A SURFACE BOUNDARY REMAINS STALLED ACROSS THE IMMEDIATE SC COAST AMD
JUST OFFSHORE OF SE NC. A WEAK SFC LOW WAS NOTED IN THE SFC WIND
FIELD IN VICINITY OF MYRTLE BEACH. A WEAK SFC RIDGE DID EXTEND SW-NE
ACROSS THE PIEDMONT OF CENTRAL NC. THIS RIDGE IS VERY SHALLOW AS
AREAS VAD WIND PROFILES DEPICT A LIGHT NE WIND CONFINED TO THE
LOWEST 1-2K FT WITH SLY FLOW ALOFT. SFC DEWPOINTS UNDERNEATH THIS
RIDGE WERE IN THE LOW-MID 50S. MEANWHILE DEWPOINTS CLOSER TO
BOUNDARY WERE IN THE 60S.
WATER VAPOR IMAGERY DEPICTS A JETLET LIFTING NE ACROSS THE LOWER MS
VALLEY THIS EVENING ALONG WITH A MINOR MID LEVEL DISTURBANCE LIFTING
NE ACROSS SE LA AND SOUTHERN MS.
THE APPROACH OF THE MID LEVEL DISTURBANCE WILL MAINTAIN AND POSSIBLY
BACK THE FLOW IN THE 925-850MB LAYER OVERNIGHT INTO EARLY SATURDAY.
WHILE THE SLY FLOW IS NOT OVERLY STRONG...THE NEAR TERM MODEL
GUIDANCE DOES SUGGEST ENOUGH UPGLIDE TO CAUSE PATCHY LIGHT RAIN OVER
SECTIONS OF THE SANDHILLS AND THE COASTAL PLAIN. MOST MODEL GUIDANCE
SUGGEST MEASURABLE RAIN A POSSIBILITY AS FAR WEST AS SILER CITY AND
BURLINGTON. THE GFS MODEL VERIFIED FAIRLY WELL AT 00Z IN ITS PRECIP
DEPICTION FIELD WHILE THE 12Z ECMWF ALONG WITH A BULK OF THE CAM
MODELS WERE TOO AGGRESSIVE. LATEST RAP MODEL (23Z) DELAYS EXPANSION
UNTIL 07Z (SEEMS REASONABLE CONSIDERING THE MID LEVEL PERTURBATION
IS WELL SW OF OUR REGION AT 00Z) WITH MEASURABLE RAINFALL AS FAR
WEST AS THE NORTHERN MOUNTAINS AND FOOTHILLS SHORTLY AFTER 12Z
SATURDAY. AT THIS TIME...THIS SEEMS TOO AGGRESSIVE CONSIDERING THE
AMOUNT OF DRY AIR NOW RESIDING OVER THE WESTERN PIEDMONT (PER 00Z
GSO SOUNDING) AND WEAK TO NON-EXISTENT 850MB MOISTURE TRANSPORT
INTO THE PIEDMONT. PLAN TO MAINTAIN HIGHEST THREAT FOR MEASURABLE
RAIN EAST OF HIGHWAY 1...AND MOSTLY OVER THE COASTAL PLAIN.
MIN TEMPS WILL DEPEND UPON THE AREAL EXTENT OF RAIN (SE HALF) AND
THICKNESS OF CLOUD COVER (NW HALF). OVER THE NW HALF...PARTLY
CLOUDY SKIES HAVE ALLOWED TEMPS TO COOL INTO THE MID-UPPER 50S AT
MID EVENING. AS CLOUDS INCREASE/THICKEN...SHOULD SEE TEMPS STABILIZE
AND MAY ACTUALLY RISE A DEGREE OR TWO AFTER MIDNIGHT. OVER THE
EAST-SE...TEMPS WILL HOLD STEADY OR SHOW A VERY SLOW DECLINE THROUGH
THE NIGHT.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
AS OF 245 PM FRIDAY...
PRECIP SHOULD BE COMING TO AN END SATURDAY MORNING AS A WEAK WAVE OF
LOW PRESSURE MOVES ACROSS THE COASTAL PLAIN AND OFF TO THE
NORTHEAST. FORECAST SOUNDINGS SHOW A DEEP SOUTHWESTERLY FLOW AND
RAPID DRYING IN THE MID LEVELS AHEAD OF THE SHORTWAVE SWINGING
THROUGH THE MIDWEST...BUT IF WE GET SUFFICIENT RAIN OVERNIGHT...LOW
CLOUDS MAY BE SLOWER TO SCOUR THAT MODELS PROJECT. ONCE CLOUDS DO
BREAK...LOWER 70S SHOULD BE ATTAINABLE.
A COLD FRONT WILL MOVE INTO WESTERN NC SATURDAY AFTERNOON AND CROSS
CENTRAL NC SATURDAY EVENING. THE MAIN HEIGHT FALLS AND DPVA
ASSOCIATED WITH THE SHORTWAVE WILL PASS TO OUR NORTH...AND WITH
MID-LEVEL DYING AHEAD OF THE FRONT...THERE WILL BE LIMITED
FORCING/MOISTURE TO PRODUCE ANY PRECIP ALONG THE FRONT. ONLY THE
ECMWF SHOWS MUCH QPF ALONG THE FRONT...AND THIS APPEARS OVERDONE.
WILL MAINTAIN JUST A SLIGHT CHANCE DURING THE AFTERNOON. COLD
ADVECTION WILL KICK IN SATURDAY NIGHT AND LOWS SHOULD DROP INTO THE
MID TO UPPER 40S FOR MUCH OF THE AREA.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 230 PM FRIDAY...
THE UPPER TROF OVER THE CENTRAL CONUS WILL BE IN PERSISTENT RELOAD
MODE THROUGH THE EXTENDED PERIOD...RESULTING IN UNSEASONABLY COOL
AND DRY WEATHER SETTLING...THEN DEEPENING OVER AREA NEXT WEEK.
WE WILL BE LOOKING AT MOSTLY CLEAR SKIES SUNDAY AND MONDAY AS HIGH
PRESSURE OVER THE AREA IS GRADUALLY SQUEEZED OFF TO THE NORTHEAST.
HIGHS WILL BE IN THE MID 60S NORTHWEST TO LOWER 70S SOUTHEAST BOTH
DAYS. AS THE HIGH MOVES OFF TO THE NORTHEAST...A FRONT WHICH HAS
BEEN LOOMING OFFSHORE SOUTH AND EAST OF THE AREA WILL MAKE A BRIEF
NORTHERLY AND WESTERLY SURGE. THE BROAD MOISTURE PLUME OF SOUTHERN
STREAM MOISTURE ASSOCIATED WITH THIS FRONT WILL SETTLE OVER THE
COASTAL PLAIN...PRODUCING A CHANCE OF SHOWERS IN THE EASTERN CWFA
LATER MONDAY NIGHT AND TUESDAY. THIS MOISTURE WILL BE SHUNTED
OFFSHORE BY A COLD FRONT LATE TUESDAY...WHICH WILL THEN USHER IN A
DEEPENING POLAR AIRMASS THROUGH THE END OF THE WEEK. HIGHS WEDNESDAY
WILL BE MAINLY IN THE MID 60S...WITH HIGHS BOTH THURSDAY AND FRIDAY
MOSTLY IN THE 60 TO 65 RANGES...BUT STRUGGLING TO REACH 60 IN THE
NORTHWEST. WE WILL SEE THE COLDEST TEMPS OF THE SEASON TO DATE AS
THE POLAR AIRMASS RADIATIONALLY COOLS OVERNIGHT...WITH MINS IN THE
40S SUNDAY THROUGH TUESDAY IN THE 40S...FALLING TO THE MID AND UPPER
30S WEDNESDAY AND THURSDAY NIGHTS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 140 AM SATURDAY...
24-HR TAF PERIOD:
A WEAK AREA OF LOW PRESSURE WILL LIFT NORTH-NORTHEASTWARD ALONG THE
STALLED FRONT ALONG COASTAL PORTIONS OF THE CAROLINAS TONIGHT.
LOW-LEVEL MOISTURE CONVERGENCE ALONG THE LOW PRESSURE WILL RESULT IN
SOME RAIN AND WIDESPREAD SUB-VFR CONDITIONS ACROSS THE AREA THROUGH
LATE MORNING/MIDDAY(15-17Z)....WITH THE HEAVIEST RAINFALL AND MOST
ADVERSE AVIATION IMPACTS OCCURRING IN THE EAST. THUS... EXPECT WE
WILL SEE CIGS RANGE FROM IFR/LIFR AT KFAY/KRWI TO GENERALLY MVFR FOR
KGSO/KINT.
AS THE AFOREMENTIONED SURFACE LOW LIFTS OFF TO THE NORTHEAST...
LOW-LEVEL FLOW WILL VEER TO WEST-SOUTHWESTERLY ADVECTING DRIER AIR
INTO THE AREA...WHICH SHOULD ALLOW CEILINGS TO IMPROVE TO VFR
BY 18Z OR SOON AFTER. THEN BETWEEN 00 TO 06Z SUNDAY...A DRY COLD
FRONT WILL MOVE THROUGH THE AREA. SFC WINDS WILL SWING AROUND TO
NWLY BEHIND THE FRONT.
LOOKING AHEAD:
VFR CONDITIONS CONDITIONS SHOULD RETURN SATURDAY EVENING/NIGHT/ WITH
THE PASSAGE OF A DRY COLD FRONT. DRY HIGH PRESSURE WILL RULE SUNDAY
AND INTO EARLY NEXT WEEK...WITH THE NEXT CHANCE FOR PRECIP AND
POSSIBLY SUB-VFR CONDITIONS ON TUESDAY AS A WAVY FRONTAL ZONE
DEVELOPS NEAR THE SE/NC COAST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...WSS
SHORT TERM...SMITH
LONG TERM...MLM
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1200 AM EDT SAT OCT 19 2013
.SYNOPSIS...
A WAVE OF LOW PRESSURE WILL FORM ALONG A STATIONARY FRONT OFFSHORE
AND MOVE ALONG THE COAST TONIGHT AND OFF TO THE NORTHEAST
SATURDAY. A SECONDARY COLD FRONT WILL PUSH THROUGH THE AREA
SATURDAY NIGHT. HIGH PRESSURE WILL PASS THROUGH SUNDAY AND MONDAY.
ANOTHER COLD FRONT WILL PUSH THROUGH TUESDAY NIGHT. HIGH PRESSURE
WILL BUILD IN FROM THE NORTHWEST LATE IN THE WEEK.
&&
.NEAR TERM /OVERNIGHT/...
AS OF MIDNIGHT...LATEST RADAR IMAGERY SHOWING CONVECTIVE SHOWERS
INC IN COVERAGE...AND BANDED STRUCTURE OF THE PRECIP INDICATE
FGEN/OMEGA INC IN THE LOW/MID LEVELS PER LATEST RUC ANALYSIS. HAVE
CATEGORICAL POPS ACROSS COASTAL AREAS...WITH LIKELY POPS FOR THE
COASTAL PLAIN. HAVE CONTINUED MENTION OF SCT THUNDER WITH DECENT
INSTABILITY DEVELOPING OVERNIGHT EAST OF LOW TRACK ALONG THE HWY
17 CORRIDOR. QPF WILL RANGE A QUARTER TO HALF AN INCH OVERNIGHT
THOUGH LOCALLY HIGHER AMOUNTS WILL FALL WITH EMBEDDED
THUNDERSTORMS.
&&
.SHORT TERM /SATURDAY/...
AS OF 3 PM FRI...AREA OF LOW PRESSURE WILL MOVE OFF TO THE
NORTHEAST DURING MIDDAY. CONTINUED LIKELY POPS THROUGH THE FIRST
HALF OF THE DAY...THEN TAPERED OFF TO CHANCE MAINLY WEST OF
HIGHWAY 17 IN THE AFTERNOON. THICKNESSES AT 18Z SHOW LITTLE CHANGE
FROM THIS AFTERNOON SO NOT MUCH CHANGE IN FORECAST HIGH TEMPS.
EXPECTING LOWER 70S NORTHWEST TO MID 70S SOUTHEAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
AS OF 315 PM FRI...UPPER TROUGH WILL SHIFT EAST OVER EASTERN
CANADA AND NEW ENGLAND SAT NIGHT WHILE THE COLD FRONT AND
ASSOCIATED PRECIP PUSH OFF THE EASTERN NC COAST. CONTINUED
PREVIOUS TREND OF POPS ENDING FROM WEST TO EAST SAT NIGHT AND
COMPLETELY OFF THE COAST AROUND SUNRISE SUN MORNING. MODEST CAA
BEHIND THE FRONT WILL KEEP TEMPS 69-71 F SUN AS A SURFACE RIDGE
SHIFTS EAST OFF THE MID-ATLANTIC COAST. STRONG SW GRADIENT ALOFT
WILL PERSIST THROUGH TUES DUE TO BROAD HIGH HOLDING STRONG OVER
THE WESTERN ATLANTIC OCEAN AND LOW PRESSURE DIGGING SOUTH THROUGH
THE WESTERN GREAT LAKES. THE REGION SHOULD REMAIN DRY SUN THROUGH
MON WITH SATURDAY NIGHTS FRONT STALLING OFFSHORE. AN AREA OF LOW
PRESSURE WILL FORM ALONG THE STALLED BOUNDARY MON NIGHT INTO TUES
AND PUSH NE NEAR THE EASTERN NC COAST...AND THUS HAVE CONTINUED
PREVIOUS TREND OF HIGHER POPS EAST OF HWY 17 AND SLIGHT CHANCE
POPS INLAND. A SHORTWAVE IN MEAN SE FLOW ALOFT OVER THE CENTRAL
CONUS WILL ROTATE AROUND THE BASE OF THE POSITIVELY-TITLED UPPER
TROUGH TOWARDS EASTERN NC TUES NIGHT INTO WED...PUSHING A
SURFACE FRONT THROUGH EASTERN NC WED NIGHT WITH MUCH COOLER THAN
NORMAL TEMPS EXPECTED FOR LATE WEEK. LOW LEVEL THICKNESSES DROP
TO 1330-1340 METERS THURS...1320-1330 METERS FRI...YIELDING MAX
TEMPS IN THE LOW 60S BOTH DAYS. MIN TEMPS WILL FALL INTO THE LOWER
40S WED NIGHT THROUGH FRI NIGHT DUE TO HIGH PRESSURE AT THE
SURFACE WITH AN OVERALL DRY COLUMN SHOULD ALLOW FOR EXCELLENT
RADIATIONAL COOLING.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH SATURDAY/...
AS OF 650 PM FRI...WEAK LOW PRESSURE WILL MOVE NORTHEAST ALONG A
FRONT STALLED JUT OFF OF THE NC COAST TONIGHT AND SATURDAY. AS THE
LOW APPROACHES LATE THIS EVENING WIDESPREAD RAIN IS EXPECTED TO
DEVELOP OVER EASTERN NC TAPERING OFF SATURDAY. WIDESPREAD PRED
MVFR CEILINGS CONTINUE EARLY THIS EVENING...THEN A PERIOD OF IFR
CONDITIONS LIKELY TO DEVELOP OVERNIGHT AS WIDESPREAD RAIN DEVELOPS.
IFR CONDITIONS ARE EXPECTED TO LINGER INTO SATURDAY MORNING IN FOG
AND STRATUS. THE LOW CLOUDS AND FOG WILL DIMINISH BY SATURDAY
AFTERNOON WITH CEILINGS LIFTING THROUGH MVFR WITH SOME BRIEF VFR
CONDITIONS POSSIBLY DEVELOPING BY MID AFTERNOON.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 330 PM FRI...MOISTURE LINGERING BEHIND THE FRONT SAT NIGHT
MAY LEAD TO REDUCED VSBYS/CEILINGS PRIOR TO SUNRISE SUN MORNING. MAINLY
VFR SUN AND MON AS HIGH PRESSURE CROSSES THE REGION. SOME SCATTERED
SHOWERS POSSIBLE TUES INTO TUES NIGHT AS AN AREA OF LOW PRESSURE FORMS
ALONG THE STALLED BOUNDARY OFF THE COAST AND PUSHES NE OFF THE
COAST THROUGH TUES NIGHT. SOME REDUCED CEILINGS AND VSBYS ARE
POSSIBLE...ESPECIALLY FOR EWN/OAJ CLOSER THE COAST. RETURN TO VFR
EXPECTED WED.
&&
.MARINE...
SHORT TERM /THROUGH SATURDAY/...
AS OF 1015 PM FRI...MARINE FORECAST IN GREAT SHAPE...NO CHANGES
NEEDED AT THIS TIME. THE LATEST BUOY OBS CONTINUE TO SHOW NE/E
WINDS 5-15 KT AND SEAS 2-4 FT. THE AREA OF LOW PRESSURE CONTINUES
TO DEVELOP ALONG A STATIONARY BOUNDARY OVER COASTAL SC. THIS LOW
PRESSURE WILL MOVE ALONG THE COAST OVERNIGHT AND IS EXPECTED TO
LIFT TO THE NE BY TOMORROW AFTERNOON. WINDS WILL BE VARIABLE
OVERNIGHT...VEERING INTO SATURDAY MORNING...EVENTUALLY BECOMING
WEST SOUTHWEST THROUGHOUT SATURDAY AFTERNOON. WIND SPEEDS AND SEAS
WILL REMAIN BELOW SMALL CRAFT LEVELS. WIDESPREAD RAIN EXPECTED
FROM LATE TONIGHT INTO MOST OF SATURDAY. SCATTERED THUNDER
POSSIBLE TONIGHT AND ISOLATED THUNDER POSSIBLE SATURDAY.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 340 PM FRI...A COLD FRONT APPROACHES FROM THE NW SAT NIGHT
AND CROSSES THE WATERS BY SUN MORNING. EXPECT A BRIEF SURGE OF NW
TO N WINDS OF 15 TO 20 KTS EARLY SUNDAY. WINDS WILL QUICKLY
SUBSIDE TO 10 TO 15 KTS LATER SUN AND BECOME MORE NE AS HIGH PRES
BUILDS TO THE N. MAINLY NE WINDS 5 TO 15 KTS SUN NIGHT AND MON AS
HIGH PRES SLIDES OFFSHORE TO THE N. COLD FRONT WILL APPROACH FROM
THE W TUES WITH A WEAK WAVE DEVELOPING NEAR THE COAST AHEAD OF
FRONT. UNCERTAINTY REMAINS FOR WINDS/SEAS TUES/WED BUT FOR NOW
LOOKS LIKE SPEEDS WILL REMAIN BELOW 15KTS.
SEAS WILL CONTINUE AT 2 TO 4 FEET SAT EVENING THEN BUILD TO 3 TO
5 FT CENTRAL AND NORTHERN WATERS EARLY SUN IN WAKE OF FRONT. SEAS
WILL SUBSIDE TO 2 TO 3 FT SUN NIGHT AND CONT IN THAT RANGE INTO
TUES. SEAS BUILD 2-4 FT TUES NIGHT THEN 3-5 FT...MAINLY FOR THE
CENTRAL AND NORTHERN WATERS DUE TO MODERATE NORTHERLY SURGE WED.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HSA
NEAR TERM...TL
SHORT TERM...HSA
LONG TERM...DAG
AVIATION...HSA/CQD/DAG
MARINE...HSA/CQD/DAG/BM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1242 AM CDT SAT OCT 19 2013
.UPDATE...
ISSUED AT 1242 AM CDT SAT OCT 19 2013
MAIN FOCUS ON THIS UPDATE WAS RAIN/SNOW CHANCES.
LATEST RADAR TRENDS CONTINUE TO SHOW ISOLATED SHOWERS ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. SHOWERS WILL REMAIN ISOLATED
ACROSS EASTERN AND CENTRAL NORTH DAKOTA AS THE AREA REMAINS IN THE
FAVORED RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET. SHOWERS WILL
COME TO AND END ACROSS CENTRAL NORTH DAKOTA EARLY SATURDAY MORNING
AS THE JET EXITS. WARM AIR ADVECTION AND WEAK ISENTROPIC ASCENT
MAY SPARK SOME ADDITIONAL SHOWERS IN WESTERN NORTH DAKOTA SATURDAY
MORNING.
THEREFORE...UPDATED PRECIP CHANCES TO REFLECT THE LATEST TRENDS
AND FORECAST GUIDANCE.
UPDATE ISSUED AT 903 PM CDT FRI OCT 18 2013
THE LATEST HRRR AND RAP13 PRECIPITATION FIELDS OVERALL FIT THE
CURRENT RADAR IMAGERY THIS EVENING. SHORTWAVE NOW INTO FAR NORTH
CENTRAL NORTH DAKOTA PER LATEST WATER VAPOR LOOP IN COMBINATION
WITH THE LEFT EXIT REGION OF A 100KT H3 JET STREAK CONTINUES TO
PROVIDE THE VERTICAL MOTION FOR PRODUCING SCATTERED SHOWERS. THIS
WILL GRADUALLY SHIFT FURTHER SOUTH AND EAST OVERNIGHT...WITH THE
PRECIPITATION EXITING THE JAMES RIVER VALLEY BY AROUND 09Z
SATURDAY. ATTENTION THEN TURNS TO THE NORTHWEST WHERE WARM AIR
ADVECTION ASSOCIATED WITH A WARM FRONTAL BOUNDARY BEGINS TO
IMPINGE FROM SOUTHERN CANADA INTO NORTHWEST AND NORTH CENTRAL
NORTH DAKOTA. ISENTROPIC LIFT PER 00Z NAM WILL LIKELY LEAD TO
ISOLATED RAIN OR SNOW SHOWERS BETWEEN 12Z AND 18Z SATURDAY IN THE
ABOVE MENTIONED AREA. THE CURRENT FORECAST HAS THIS FORECAST
ALREADY IN PLACE.
UPDATE ISSUED AT 524 PM CDT FRI OCT 18 2013
LATEST WATER VAPOR SHOWS A SHORTWAVE ALONG THE SOUTHERN SASKATCHEWAN
AND MANITOBA BORDER DIVING SOUTH WITH TIME. AN AREA OF VERTICAL
MOTION/H85-H3 OMEGA AHEAD OF THIS WAVE CONTINUES TO RESULT IN
SURFACE PRESSURE FALLS AND SCATTERED RAIN SHOWERS IN NORTH CENTRAL
NORTH DAKOTA. THE LATEST HRRR FORECASTS THIS AREA TO SHIFT SOUTH
AND INCREASE IN AREAL COVERAGE FOR SOUTH CENTRAL NORTH DAKOTA
THROUGH 04Z. CONCUR WITH THIS IDEA PER LATEST RADAR RETURNS. THERE
COULD BE SOME SNOW OR GRAPPLE WITHIN HEAVIER CONVECTIVE SHOWERS
THIS EVENING AS THE SHALLOW SURFACE WARM LAYER COOLS WITH SUPERCOOLED
WATER DROPLETS DOMINATING ABOVE. MAIN FORECAST REMAINS ON TRACK
WITH MINOR UPDATES TO HOURLY GRIDDED DATA.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 251 PM CDT FRI OCT 18 2013
SMALL POCKETS OF LIGHT RAIN WILL CONTINUE TO DEVELOP AND PUSH
SOUTHEAST THROUGH THE AFTERNOON HOURS. THE HIGHEST PRECIPITATION
COVERAGE IS EXPECTED NORTHEAST OF A LINE FROM KENMARE TO BISMARCK AND
ELLENDALE. AS NEAR SURFACE TEMPS DROP OFF TONIGHT...EXPECT RAIN TO
BECOME MIXED WITH OR CHANGE OVER TO ALL SNOW. THERE MAY BE SOME
VERY MINOR ACCUMULATIONS ON GRASSY SURFACES...MAINLY FROM
BOTTINEAU...TO CARRINGTON AND JAMESTOWN.
ON SATURDAY...A WARM FRONT WILL PUSH INTO WESTERN NORTH DAKOTA
DURING THE MORNING HOURS. A BAROCLINIC ZONE NEAR THE BOUNDARY MAY
BE ENOUGH TO SUPPORT A FEW LIGHT SNOW SHOWERS...MAINLY DURING THE
MORNING HOURS. AGAIN...LITTLE OR NO ACCUMULATION IS EXPECTED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 251 PM CDT FRI OCT 18 2013
THE LONG TERM FORECAST WILL BE DOMINATED BY NORTH/NORTHWEST FLOW
ALOFT WITH A TROUGH OVER EASTERN CANADA/US AND A WESTERN RIDGE OVER
WESTERN CANADA/US.
THE MAIN FOCUS IN THE LONG TERM WILL BE SNOW AMOUNTS IN THE
NORTHEAST PART OF THE FORECAST AREA...BOTTINEAU-ROLLA-RUGBY-HARVEY
LATE SATURDAY NIGHT INTO SUNDAY MORNING. OTHER THAN THAT THERE WILL
BE A CHANCE OF LIGHT PRECIPITATION MONDAY/MONDAY NIGHT.
REGARDING THIS SATURDAY NIGHT/SUNDAY CLIPPER EVENT...TODAY`S MODELS
ARE INDICATING WARM AIR ADVECTION AHEAD OF THE SURFACE CLIPPER -
ENOUGH SUCH THAT PRECIPITATION SATURDAY EVENING AND INTO VERY EARLY
SUNDAY MORNING WOULD BE AHEAD AND EAST OF THE SURFACE LOW AND IN THE
FORM OF RAIN. RAIN WOULD NOT BE CHANGING TO SNOW UNTIL ROUGHLY 3 AM
IN THE TURTLE MOUNTAINS...THOUGH FARTHER WEST THE CHANGE TO SNOW MAY
OCCUR AROUND MIDNIGHT SATURDAY NIGHT. A GOOD AMOUNT OF THE
PRECIPITATION ASSOCIATED WITH THIS SYSTEM IS PROGGED TO BEGIN LATE
AFTERNOON/EARLY EVENING...WITH THE BEST LIFT AND MORE INTENSE
PRECIPITATION OCCURRING BEFORE MIDNIGHT. THE SURFACE LOW IS PROGGED
TO MOVE SOUTH FROM SASKATCHEWAN AND CROSS THE NORTH DAKOTA BORDER
BETWEEN 10 PM AND MIDNIGHT. THUS THE BULK OF THE ASSOCIATED
PRECIPITATION SHOULD BE IN THE FORM OF RAIN.
REGARDING SNOW AMOUNTS...THE LATEST EXPECTATION IS THAT THE TURTLE
MOUNTAINS MAY RECEIVE UP TO 2 INCHES OF SNOW FROM SATURDAY NIGHT
THROUGH SUNDAY...WITH HALF AN INCH TO AN INCH IN THE SURROUNDING
AREAS FROM BOTTINEAU TO NORTHERN MCHENRY TO PIERCE COUNTIES. LESSER
AMOUNTS EXPECTED ACROSS NORTHWESTERN NORTH DAKOTA TO THE NORTHERN
JAMES RIVER VALLEY.
WINDY AS WELL SATURDAY NIGHT AND SUNDAY AS THE CLIPPER LOW MOVES
FROM THE NORTH CENTRAL TO SOUTHEASTERN NORTH DAKOTA. NORTHWEST WINDS
OF 20 TO 30 MPH EARLY SUNDAY MORNING IN THE WEST...AND DAYTIME
SUNDAY OVER WESTERN AND CENTRAL NORTH DAKOTA.
A NEXT WEAKER WAVE IS THROUGH ON MONDAY / TUESDAY...FOLLOWED BY THE
BUILDING H5 RIDGE WITH DRIER AND MORE SEASONAL TEMPERATURES. THE
REST OF THE LONG TERM WILL SEE HIGHS IN THE 30S AND 40S OVER CENTRAL
NORTH DAKOTA...AND 40S TO LOWER 50S OVER WESTERN NORTH DAKOTA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1242 AM CDT SAT OCT 19 2013
ISOLATED RAIN/SNOW SHOWERS AND VFR TO MVFR CIGS ARE EXPECTED FOR
THE NEXT 24 HOURS. EARLY SATURDAY MORNING...IT APPEARS KBIS/KJMS
WILL HAVE THE HIGHEST PROBABILITY FOR SHOWERS WITH KISN AND KMOT
SEEING THE BEST CHANCE LATE MORNING. CIGS WILL LIFT TO VFR AND
WINDS WILL SHIFT BRIEFLY OUT OF THE SOUTH SATURDAY AFTERNOON AS
A WARM FRONT MOVES THROUGH CENTRAL NORTH DAKOTA.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AJ
SHORT TERM...RP KINNEY
LONG TERM...JV
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
428 AM CDT SAT OCT 19 2013
.DISCUSSION...
COLD FRONT PUSHING SOUTH THROUGH TEXAS AT 09Z (4AM CDT) ABOUT AT
A KLFK/KUTS/K11R LINE OR BASICALLY A BRENHAM TO LUFKIN LINE. LINE
OF SHOWERS AND THUNDERSTORMS OVER HOUSTON EARLIER TONIGHT HAS
WEAKENED AND ACTIVITY HAS INCREASED MORE OFF THE UPPER TX COAST.
UPPER LEVEL SHORT WAVE LOOKS TO BE MOVING OUT OF THE AREA AND
POSSIBLE THAT UPPER LEVEL DIVERGENCE IS WEAKENING AS A RESULT.
BULK OF EARLIER CONVECTION HAS BEEN SUPPORTED BY SOME ISENTROPIC
LIFT AND FRONTOGENESIS IN 925-850MB LAYER PER SPC MESOANALYSES.
PER LATEST RADAR TRENDS...EXPECT SOME LINGERING SHOWERS ALONG THE
COAST BUT LOOKS LIKE MOST OF THE RAINFALL MAY BE DONE BY 12Z WHICH
IS A GOOD 3-6 HRS SOONER THAN MOST 00Z MODEL SOLUTIONS. HOWEVER
THE 00Z TX TECH 3KM WRF AND LATEST 06Z HRRR ARE IN GOOD AGREEMENT
WITH LATEST TRENDS. FORECAST HAS BE TRENDED TOWARDS THESE MODELS
IN THE SHORT TERM BUT MAY HOLD ONTO PRECIP A LITTLE LONGER. COLD
FRONT SHOULD BE OFF THE COAST BETWEEN 12-15Z THIS MORNING WITH
STRONG NORTHERLY WINDS ARE WIDE. UPPER LEVEL TROUGH AXIS WILL ALSO
HAVE PUSHED BY SE TX WITH RIGHT REAR QUADRANT OF JET STREAK STILL
LINGERING OVER THE AREA. HIGH PRESSURE AT THE SURFACE SHOULD
CONTINUE TO BUILD OVER TX TODAY. MAX TEMPS WILL BE A CHALLENGE AS
DO EXPECT SOME COLD ADVECTION TO OCCUR. HOWEVER 850MB TEMPS ONLY
DROP TO ABOUT 12-13C SO COULD STILL SEE TEMPS REACHING UPPER 60S
TO LOW 70S WITH DAYTIME HEATING. CLOUD COVER SHOULD CLEAR OUT SO
MAY NOT GET QUITE AS COOL AS IT COULD WITH BULK OF COLDER AIRMASS
MOVING EAST OF THE AREA OVER MISS RIVER VALLEY.
LOOKS LIKE RETURN FLOW AND WARM ADVECTION WILL ENSUE ONCE AGAIN
SUN NIGHT INTO MONDAY. VERY SIMILAR SET UP TO THE MOST RECENT RAIN
EVENT WITH WEAK ISENTROPIC LIFT AND A SHORT WAVE TROUGH ROTATING
THROUGH THE S PLAINS PROVIDING ENOUGH LARGE SCALE ASCENT FOR
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. THINK ORIENTATION OF
JET STREAK AND SHORT WAVE TROUGH MAY PUSH BULK OF PRECIP EAST OF
SE TX SO HAVE NOT CHANGED POPS MUCH. BEST CHANCES WILL AGAIN BE
ALONG THE COAST BUT WILL KEEP AROUND 50 PERCENT FOR NOW. ANOTHER
COLD FRONT WILL ALSO PUSH INTO SE TX BUT MORE SO MON NIGHT INTO
TUE MORNING. BEST LIFT WILL HAVE SHIFTED EAST BY THIS TIME SO WILL
BE HAVING DECREASING RAIN CHANCES MON NIGHT INTO TUE.
TUE THROUGH THE REST OF THE WEEK SHOULD BE DRY WITH A RATHER
AMPLIFIED UPPER LEVEL PATTERN. BROAD RIDGE SHOULD REMAIN OVER THE
PACIFIC COAST WITH A DEEP LOW AND LONG WAVE TROUGH OVER THE GREAT
LAKES AND MIDWEST. SEVERAL SHORT WAVE TROUGHS MOVING THROUGH THE
FLOW SHOULD KEEP THE TROUGH OVER THE GREAT LAKES THROUGH THE END
OF THE WEEK. WILL GET SFC HIGH PRESSURE BUILDING OVER TX THROUGH
WED WITH ANOTHER RIDGE BUILDING OVER THE MIDWEST THUR INTO FRI.
PATTERN SHOULD KEEP CONDITIONS DRY AND ON THE COOL SIDE. TRIED TO
BLEND THE TEMP FORECAST BETWEEN GFS AND ENSEMBLE MEAN TEMPS FOR
THE LATER HALF OF THE WEEK. THIS WILL MEAN TEMPS WILL BE NEAR OR
EVEN A DEGREE OR TWO BELOW NORMAL FOR THE END OF NEXT WEEK.
39
&&
.MARINE...
NORTHERLY WINDS HAVE REACHED THE NEARSHORE BUOY THIS MORNING AS A
PREFRONTAL TROUGH PUSHES OUT AHEAD OF THE COLD FRONT MOVING INTO
SOUTHEAST TEXAS. EXPECT OFFSHORE WINDS TO PICK UP THROUGH THE
MORNING WITH BUILDING SEAS AS THE FRONT MOVES OFFSHORE. ADVISORY
FLAGS IN PLACE ACROSS ALL COASTAL WATERS TODAY AND MAY NEED TO BE
EXTENDED FURTHER STILL...ALTHOUGH WILL ALLOW NEXT SHIFT TO
EVALUATE NEW MODEL DATA AND OBSERVATIONS FROM TODAY BEFORE MAKING
THAT DECISION. EXPECT A QUICK RETURN OF ONSHORE WINDS LATE THIS
WEEKEND AHEAD OF YET ANOTHER FRONTAL PASSAGE EXPECTED LATE MONDAY
INTO TUESDAY. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 68 45 75 58 78 / 10 10 0 10 20
HOUSTON (IAH) 72 47 77 59 78 / 20 10 0 10 40
GALVESTON (GLS) 74 58 76 68 79 / 40 10 10 20 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 6 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...39
AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
326 AM CDT SAT OCT 19 2013
.TODAY...FORECAST CONFIDENCE IS HIGH.
FULL LATITUDE TROUGH PHASING JUST ABOUT OVERHEAD CURRENTLY WITH
110 METER 500 MB HEIGHT FALLS CENTERED OVER NORTHERN ILLINOIS
FIRST THING THIS MORNING. DEVELOPING BAROCLINIC LEAF AND SWATH OF
LIGHT PRECIPITATION SHOULD STAY TO THE SOUTH AND EAST.
CIRCULATION WITH DIGGING UPSTREAM TROUGH NOW ALONG MN/ND BORDER
HAS PV1.5 SURFACE POKING BELOW 500 MB AND THIS IS EXPECTED TO MOVE
INTO SOUTHEAST MINNESOTA THIS MORNING AND ACROSS SOUTHERN
WISCONSIN THIS AFTERNOON. EVEN THOUGH HEIGHTS STOP FALLING DURING
THE DAY THE 500 MB COLD CORE OF -30C MOVES ACROSS DURING PEAK
DIURNAL HEATING...WITH MODELS SHOWING STEEP LAPSE RATES IN THE LOW
LEVELS.
LATEST HRRR SHOWS BANDS OF CONVECTIVE SHOWERS MOVING ACROSS DURING
THE LATE MORNING AND AFTERNOON WHICH SEEMS REASONABLE. WOULD NOT
BE SURPRISED IF THERE IS GRAUPEL MIXED IN GIVEN THE LOW FREEZING
LEVEL WITH THE HEAVIER SHOWERS.
.TONIGHT...FORECAST CONFIDENCE IS HIGH.
HEIGHTS RISE ABOUT 90 METERS OVERNIGHT AND MODELS SHOW SIGNIFICANT
MID LEVEL DRYING DURING THE NIGHT. PROBABLY WILL NOT COMPLETELY
CLEAR OUT BUT BREAKS IN CLOUDS AND LIGHT WINDS FROM LATE EVENING
INTO THE 3-4 AM PERIOD SHOULD BE SUFFICIENT FOR READINGS TO DROP
TO AROUND FREEZING. MARGINAL NATURE OF EVENT SUGGESTS THAT A FROST
ADVISORY WOULD WORK BEST.
.SUNDAY THROUGH MONDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM TO
HIGH.
SHORT TERM MODELS IN DECENT AGREEMENT WITH FEATURES DURING THIS
PERIOD. SURFACE LOW PRESSURE TRACKS FROM SOUTHEASTERN NORTH DAKOTA
TO NORTHWEST WISCONSIN SUNDAY...THEN INTO NORTHERN LAKE SUPERIOR
SUNDAY NIGHT. FOCUSED WARM AIR ADVECTION SPREADS THROUGH THE
REGION AHEAD OF THE LOW ON SUNDAY...WITH A STRONG COLD FRONT
PUSHING EAST THROUGH THE AREA LATE SUNDAY/SUNDAY EVENING.
GOOD LOW LEVEL Q VECTOR CONVERGENCE ALSO SEEN SUNDAY ACROSS THE
AREA. AREA FORECAST SOUNDINGS SHOWING GOOD MID LEVEL MOISTURE
SUNDAY...WITH LOW LEVELS SLOWLY TRYING TO MOISTEN BY LATE IN THE
DAY AND EARLY SUNDAY EVENING. BEST UPWARD VERTICAL MOTION AND DEEP
MOISTURE IS TOWARD CENTRAL WISCONSIN...THOUGH QPF DOES PASS
THROUGH MOST OF THE AREA EXCEPT THE FAR SOUTH.
HAVE LIKELY POPS IN THE FAR NORTHWEST COUNTIES LATER SUNDAY
AFTERNOON...WITH HIGHER END CHANCE POPS SUNDAY INTO SUNDAY EVENING
ACROSS THE NORTHERN HALF OF THE AREA. LOW POPS WERE KEPT IN THE
SOUTH. TEMPERATURE PROFILES WILL BE WARM ENOUGH FOR ALL RAIN.
HIGHS IN THE 50S ARE EXPECTED SUNDAY...BEFORE COLD AIR ADVECTION
WITH BRISK WEST WINDS BEHIND COLD FRONT BRINGS COLDER AIRMASS INTO
THE REGION. LOWS SHOULD DROP INTO THE MID TO UPPER 30S SUNDAY
NIGHT. QUIET WEATHER BUT CHILLY DAY EXPECTED ON MONDAY...WITH
HIGHS ONLY IN THE 40S WITH BRISK WEST WINDS CONTINUING.
ADDED LOW POPS FOR LIGHT RAIN/SNOW SHOWERS IN THE FAR NORTH AND
NORTHEAST COUNTIES MONDAY NIGHT...WITH PASSING 500MB VORTICITY
MAXIMUM WITHIN LARGER CYCLONIC FLOW. GOOD SHOT AT FREEZE WARNING
CRITERIA FOR MONDAY NIGHT...AS LOWS SHOULD DROP INTO THE UPPER 20S
TO LOWER 30S ACROSS THE AREA...WITH DECREASING WEST WINDS. LATER
SHIFTS MAY CONSIDER A FREEZE WATCH FOR THE ENTIRE AREA FOR MONDAY
NIGHT.
.TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
ECMWF/GFS SHOWING SOME DIFFERENCES DURING THIS PERIOD. THEY SHOW
A GENERAL NORTHWEST FLOW AT 500MB CONTINUING THROUGH THE
WEEK...WITH SEVERAL VORTICITY MAXIMA SHIFTING THROUGH THE REGION.
THERE ARE TIMING DIFFERENCES WITH THESE FEATURES BETWEEN
ECMWF/GFS.
AT THE SURFACE...WEAK LOW PRESSURE PASSES WELL SOUTHWEST OF THE
AREA TUESDAY ON THE ECMWF/GFS. THEY BOTH THEN BRING HIGH PRESSURE
SOUTHEAST ACROSS THE CENTRAL PLAINS TUESDAY NIGHT. GFS THEN BRINGS
ANOTHER LOW SOUTHEAST THROUGH THE AREA LATER WEDNESDAY AND
WEDNESDAY EVENING...NOT SHOWN ON THE ECMWF.
BOTH MODELS THEN BRING HIGH PRESSURE SOUTHEAST THROUGH THE CENTRAL
PLAINS AGAIN THURSDAY INTO FRIDAY. THEY BOTH DO MAINTAIN THE COLD
AIRMASS OVER THE REGION. FOLLOWED CONSENSUS POPS AND TEMPERATURES
FOR THIS PERIOD. HIGHS SHOULD ONLY REACH THE 40S TUESDAY INTO
FRIDAY. LOWS SHOULD REMAIN IN THE UPPER 20S TO LOWER 30S
INLAND...WITH LOWER TO MID 30S LAKESIDE.
&&
.AVIATION/12Z TAFS/...
VFR MID LEVEL CLOUDS ARE EXPECTED MUCH OF THE TIME. UNSTABLE
CONDITIONS DURING THE LATE MORNING AND AFTERNOON WILL RESULT IN
CONVECTIVE SHOWERS WITH LOCALLY GUSTY WINDS...SMALL HAIL...AND
BRIEF MVFR CONDITIONS. THESE CONDITIONS WILL BE MOST LIKELY IN THE
KMSN AREA AND SOMEWHAT LESS LIKELY UNTIL LATE AFTERNOON IN THE
SOUTHEAST TAF SITES.
PARTIAL CLEARING IS EXPECTED TONIGHT WITH VFR CONDITIONS.
&&
.MARINE...
LAKE TO 850 MB TEMPERATURE DIFFERENCE INCREASES TO ABOUT 19 THIS
AFTERNOON AS COLD CORE MOVES ACROSS LAKE MICHIGAN. WESTERLY FLOW
REGIME SUGGESTS THAT WATERSPOUT THREAT SHOULD BE CONFINED MAINLY
TO CENTRAL AND EASTERN PORTION OF THE LAKE WHICH WOULD INCLUDE
EXTREME EASTERN PORTIONS OF THE OPEN WATERS.
FAST MOVING LOW ON SUNDAY WILL MOVE ACROSS WISCONSIN AND THEN SLOW
DOWN AS IT MOVES ACROSS LAKE SUPERIOR MONDAY AND MONDAY NIGHT.
THIS WILL BE A WINDY SYSTEM WITH STRONG SOUTH TO SOUTHWEST WINDS
SUNDAY NIGHT TURNING TO THE WEST AND EVENTUALLY NORTHWEST MONDAY
AND MONDAY NIGHT. SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED
OVER THE COASTAL WATERS WITH GUSTY WINDS...WITH GALE FORCE WINDS
AND HIGH WAVES POSSIBLE OVER THE OPEN WATERS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY FROM 1 AM TO 8 AM CDT SUNDAY FOR WIZ046-047-051-
052-056>060-062>072.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...CRAVEN
SUNDAY THROUGH FRIDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1105 PM CDT FRI OCT 18 2013
.UPDATE...
ISSUED AT 911 PM CDT FRI OCT 18 2013
THE CHANCES FOR PRECIPITATION TONIGHT INTO EARLY SATURDAY MORNING
ARE LOOKING LESS LIKELY NOW. THE FOCUS FOR PRECIPITATION TONIGHT
WAS ON A SHORTWAVE COMING ACROSS SOUTHWEST MINNESOTA. KMPX RADAR
SHOWS A BAND OF LIGHT RETURNS WHICH AT MOST HAVE PRODUCED
SPRINKLES AT REDWOOD FALLS IN THE PAST HOUR. OTHERWISE...THE BULK
OF THE RETURNS ARE VIRGA...DUE TO DRY LOW LEVEL AIR BELOW THE
7000-8000 FT CLOUD BASES AS SEEN ON THE 00Z MPX SOUNDING. RECENT
HRRR MODEL RUNS HAVE HAD A GOOD HANDLE ON THIS BAND OF LIGHT
PRECIPITATION...SUGGESTING IT WILL DIMINISH AS IT MOVES FURTHER
EAST INTO THE DRIER AIR. ADDITIONALLY...THE FORCING OVERALL FROM
THE SHORTWAVE JUST SEEMS TO BE WEAKENING. BELIEVE THIS IS DUE TO A
SOMEWHAT STRONGER SHORTWAVE DROPPING INTO EASTERN NORTH DAKOTA AS
SEEN ON WATER VAPOR. ADDITIONALLY...THIS SHORTWAVE HAS A 100-110
KT JET STREAK AT THE TROPOPAUSE ON ITS WESTERN SIDE PER RAP
ANALYSIS. THIS SHORTWAVE WILL BRING A MUCH GREATER CHANCE FOR
PRECIPITATION TO THE FORECAST AREA. TIMING OF THIS PRECIPITATION
HAS BECOME MORE PROBLEMATIC BY THE 18.23Z HRRR HAVING IT STILL
WEST OF I-35 AT 14Z...COMPARED TO THE 18.18Z NAM AND 18.15Z SREF
WHICH SUGGESTED IT ALREADY NEARING RST AT THE TIME.
FOR THE PRECIPITATION FORECAST...HAVE LOWERED CHANCES TO BASICALLY
DRY TONIGHT TO ABOUT 13-14Z SATURDAY MORNING. ONLY LEFT A 20
PERCENT CHANCE AROUND TAYLOR COUNTY PER 18.18Z NAM SUGGESTING
TAYLOR COUNTY COULD GET BRUSHED. CHANCES THEN RAMP UP WEST TO EAST
TO 60 BETWEEN THE 15-19Z PERIOD AS THE NEXT SHORTWAVE AND UPPER
JET STREAK FORCING IMPACTS THE AREA.
TEMPERATURES ARE AN ISSUE TONIGHT TOO. WHERE BREAKS HAVE DEVELOPED
IN THE CIRRUS OVER CENTRAL WISCONSIN...READINGS HAVE ALREADY
DROPPED TO NEAR/AROUND FREEZING. EVEN OVER SOUTHEAST MN DODGE
CENTER HAS FALLEN TO 35. HAVE LOWERED TEMPERATURES A FEW
DEGREES...BUT A STREAM OF BROKEN MID CLOUDS ACROSS MINNESOTA AND
NORTHWEST IOWA WILL MOVE THROUGH THE AREA OVERNIGHT. THESE CLOUDS
MAY CAUSE TEMPERATURES TO FLUCTUATE QUITE A BIT. ADDED AT LEAST
SOME PATCHY-AREAS OF FROST MENTION TO MUCH OF THE FORECAST
AREA RESULTING FROM THE LOWERING OF TEMPERATURES. CONFIDENCE IS
NOT HIGH ENOUGH TO ISSUE ANY FROST ADVISORIES IN OUR AREA THAT ARE
STILL ACTIVE / COUNTIES WEST OF I-94 / GIVEN CLOUD ISSUES.
&&
.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 333 PM CDT FRI OCT 18 2013
MAIN FORECAST CONCERN IS COLDER THAN NORMAL TEMPERATURES AND BOUTS
OF PRECIPITATION.
WATER VAPOR IMAGERY FEATURES A DEEP/ELONGATED LONGWAVE TROUGH OF LOW
PRESSURE EXTENDING FROM WESTERN HUDSONS BAY CANADA THROUGH THE UPPER
MISSISSIPPI RIVER AND INTO THE DESSERT SOUTHWEST. WITHIN THE LONGWAVE
TROUGH...A SHORTWAVE TROUGH WAS DROPPING SOUTHWARD OUT OF SOUTHERN
SASKATCHEWAN. VISIBLE SATELLITE SHOWING THE RESULT OF THE VERY
CHILLY AIR ALOFT WITH WIDESPREAD CUMULUS/STRATOCUMULUS ACROSS THE
DAKOTAS INTO MN/WESTERN WI. RADAR MOSAIC WAS EVEN SHOWING ISOLATED
SHOWERS ACTIVITY ACROSS NORTHEAST MN AND THE EASTERN DAKOTAS IN
ADVANCE OF THE SASKATCHEWAN WAVE. OTHERWISE...UNSEASONABLY COOL
AIRMASS IN PLACE ACROSS THE REGION WITH TEMPERATURES THIS AFTERNOON
STRUGGLING THROUGH THE 40S TO NEAR 50. THIS IS SOME 10-15 DEGREES BELOW
NORMAL.
FOR TONIGHT...THE WAVE OVER SASKATCHEWAN WILL DEEPEN SLIGHTLY AND
MOVE SOUTHEASTWARD INTO THE EASTERN DAKOTAS. NOT MUCH FORCING
ASSOCIATED WITH THIS WAVE OTHER THAN STEEPENING LAPSE RATES AND
SLIGHTLY INCREASED CYCLONIC FLOW. BASED ON THIS...WILL GO WITH
SMALL-END PRECIPITATION PROBABILITIES. IF SHOWERS DO DEVELOP...
THERMAL PROFILES SUPPORT MAINLY RAIN BUT CANNOT RULE OUT SOME SNOW
FLAKES NORTHEAST OF I-94. LOOK FOR OVERNIGHT LOWS IN THE MIDDLE TO
UPPER 30S.
AS THE TROUGH ROTATES OVER THE AREA SATURDAY...A STEEPENING LAPSE
RATE OF 8-10C/KM IN THE LOWEST 3KM AND CYCLONIC FLOW IS EXPECTED TO
GENERATE SCATTERED-NUMEROUS RAIN SHOWERS. OTHERWISE...PLAN ON HIGHS
IN THE 40S.
A FEW SHOWERS MAY LINGER INTO SATURDAY EVENING NORTHEAST OF
I-94...BUT THEN CLEARING IS EXPECTED LATER INTO THE EVENING AND
OVERNIGHT AS A WEAK RIDGE OF HIGH PRESSURE PASSES OVERHEAD. THIS
WILL SET UP GOOD RADIATIONAL COOLING WITH AREAS-WIDESPREAD FROST
LIKELY FOR MOST AREAS. OVERNIGHT LOWS ARE EXPECTED TO BOTTOM OUT IN
THE UPPER 20S NORTHEAST OF I-94...TO NEAR THE FREEZING MARK FOR ALL
OTHER LOCATIONS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 333 PM CDT FRI OCT 18 2013
MODELS SHOWING A FAIRLY VIGOROUS MID-LEVEL TROUGH AND SURFACE LOW
DROPPING ACROSS THE DAKOTAS INTO SOUTHERN MN/WESTERN WI BY SUNDAY
AFTERNOON. MODELS SHOWING FAIRLY STRONG 850-500MB
PV-ADVECTION/ISENTROPIC LIFT ASSOCIATED WITH THIS WAVE. THIS HAS
BEEN A VERY CONSISTENT SIGNAL FOR THE LAST FEW DAYS OF MODEL RUNS
NOW. BASED ON THIS...WILL GO WITH LIKELY TO CATEGORICAL
PROBABILITIES ALONG AND NORTHEAST OF I-94...TAPERING TO CHANCES TO
THE SOUTH OF I-94. THERMAL PROFILES HINT THERE MAY BE A CHANCE THAT
AS THE PRECIPITATION MOVES IN SUNDAY MORNING...IT MAY FALL AS A
SNOW/RAIN MIX NORTH OF I-94. OTHERWISE WITH TEMPERATURES MODERATING
INTO THE 40S AND LOWER 50S DURING THE DAY...LOOK FOR THIS
PRECIPITATION TO BE ALL RAIN FROM MID-MORNING ONWARD THROUGH THE
REST OF THE DAY.
THIS LOW PULLS OFF INTO UPPER MICHIGAN SUNDAY EVENING...SPILLING
COLDER AIR INTO THE AREA. DEPENDING ON THE TIMING OF THIS COLD AIR
WITH THE TAPERING PRECIPITATION...THERE COULD BE A SLUSHY 1/4-1/2
INCH ACROSS NORTHERN PARTS OF TAYLOR COUNTY. THE PRECIPITATION IS
EXPECTED TO DIMINISH COMPLETELY AFTER MIDNIGHT AS THE LOW PULLS INTO
SOUTHERN ONTARIO. LOOK FOR OVERNIGHT LOWS IN THE 30-35 DEGREE RANGE.
ON MONDAY...MODELS SHOWING ANOTHER MID-LEVEL SHORTWAVE TROUGH
ROTATING SOUTHWARD AROUND THE NOW CLOSED/STACKED LOW OVER SOUTHERN
ONTARIO...INTO NORTHERN MN/WI. THE NAM IS SPREADS PRECIPITATION
FARTHEST SOUTH INTO THE AREA ASSOCIATED WITH THIS WAVE. MODEL
CONSENSUS YIELDS A 20-40 PERCENT PROBABILITY OF PRECIPITATION NORTH
OF I-94 WITH THE BULK OF THE PRECIPITATION STAYING NORTH OF THE
AREA. AGAIN...THERMAL PROFILES SHOW PRECIPITATION COULD BE ALL SNOW
IN THE MORNING...CHANGING TO ALL RAIN DURING THE REST OF THE DAY AS
HIGHS TO OFF IN THE UPPER 30S TO THE MIDDLE 40S.
THE EXTENDED MODELS CONTINUE TO SHOW A DEEP TROUGH ACROSS THE
EASTERN CONUS THROUGH THE REST OF THE PERIOD AS A RIDGE BUILDS OVER
THE WEST COAST. THIS KEEPS OUR AREA IN NORTHWEST FLOW ALOFT WITH
TEMPERATURES REMAINING SOME 10 DEGREES BELOW NORMAL WITH HIGHS ONLY
ON THE 40S. WITH MODELS HAVING A HARD TIME WITH STRENGTH AND
TIMING OF WEAKER WAVES RIPPLING THROUGH THIS NORTHWEST
FLOW...MODEL CONSENSUS IS FOR GENERALLY DRY STRETCH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1105 PM CDT FRI OCT 18 2013
DRY AIR IN THE LOWER LEVELS OF THE ATMOSPHERE SHOULD HELP TO KEEP
CONDITIONS VFR THROUGH MUCH OF THE MORNING HOURS. THE MAIN CAVEAT
TO THIS IS POSSIBLE VALLEY FOG AT LSE...IF SKIES CAN REMAIN CLEAR
LONG ENOUGH FOR IT TO FORM. RIGHT NOW CONFIDENCE OF A CLEAR SKY
FOR THE REST OF THE NIGHT IS VERY LOW GIVEN MORE HIGH BASED
STRATUS COMING INTO SOUTHEAST MINNESOTA. THE MAIN IMPACT TO THE
TAF SITES DURING THE NEXT 24 HOURS IS A LOW PRESSURE TROUGH MOVING
THROUGH NORTH DAKOTA. THIS TROUGH SHOULD MOVE INTO THE TAF SITES
BETWEEN 16-19Z...PRODUCING SHOWERS AND LOWER CEILINGS. CEILINGS
SHOULD DROP TO MVFR AT RST AND VERY LOW VFR AT LSE. AFTER THE
TROUGH PASSES...BETWEEN 21-22Z...EXPECT VFR CONDITIONS TO RETURN
WITH SKIES CLEARING LATER IN THE EVENING AS DRIER AIR MOVES IN.
LOOK FOR WINDS TO BRIEFLY INCREASE TOO IN THE WAKE OF THE TROUGH
OUT OF THE WEST-NORTHWEST BETWEEN 10-15 KT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1127 AM EDT SAT OCT 19 2013
.SYNOPSIS...
ISSUED AT 1114 AM EDT SAT OCT 19 2013
THE RAIN WILL BE ENDING FOR MUCH OF THE REGION TODAY AS AN UPPER
LEVEL TROUGH MOVES THROUGH THE AREA. AREAS NEAR LAKE MICHIGAN
COULD STILL SEE SOME LAKE EFFECT SHOWERS THROUGH THE DAY AS
TEMPERATURES REMAIN COOL. HIGH TEMPERATURES TODAY WILL RANGE FROM
THE UPPER 40S IN THE EAST TO THE LOWER 50S IN THE WEST. TONIGHT
THE LAKE EFFECT RAIN SHOWERS WILL BE ENDING. THERE WILL BE A
CHANCE FOR SOME PATCHY FROST LATE TONIGHT/EARLY IN THE MORNING AS
TEMPERATURES DROP DOWN INTO THE UPPER 30S. THEN TOMORROW THERE
WILL BE MORE SUNSHINE AS TEMPERATURES REACH TO AROUND 60 TO THE
LOWER 60S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SAT OCT 19 2013
SEVERAL FORECAST ISSUES TO CONSIDER FOR THIS PACKAGE...ALL REVOLVING
AROUND PRECIP CHANCES.
UPPER LEVEL TROUGH AXIS WAS LOCATED FROM WESTERN MINNESOTA TO
CENTRAL OKLAHOMA WITH STG WAVE QUICKLY ROUNDING THE BASE AND HEADING
NE TOWARDS THE LOWER GREAT LAKES/OHIO VALLEY. UPWARD MOTION WAS
RAPIDLY INCREASING ACROSS THE REGION IN RESPONSE TO INCREASING MID
LEVEL HGT FALLS APPROACHING 120 M/12 HRS ONCE AGAIN PASS ACROSS THE
AREA. LIGHT RAIN/DRIZZLE HAS BEEN SLOWLY EXPANDING ACROSS CENTRAL
ILLINOIS AND WAS RAPIDLY MOVING/EXPANDING NE INTO MUCH OF THE
FORECAST AREA. AS A RESULT HAVE HAD TO BUMP UP POPS DRAMATICALLY IN
MANY AREAS AND ALSO SPEED ARRIVAL/DEPARTURE TIMES. PERIODS OF
RAIN/SHOWERS WILL LIKELY IMPACT MANY SPOTS GENERALLY SE OF KNOX TO
THREE RIVERS LINE WITH HIGH LIKELY/CAT POPS WARRANTED IN THESE
AREAS. HRRR HAS HANDLED OVERALL EVOLUTION WELL OVER THE PAST SEVERAL
RUNS AND QUICKLY EXITS PRECIP BY 17Z. GRIDS NOW SHOWING THESE TRENDS
WITH QPF ON THE ORDER OF A FEW HUNDREDTHS TO MAYBE NEAR A QUARTER
INCH (SE AREAS) WITH A BRIEF LULL INTO MID AFTERNOON BEFORE FOCUS
SHIFTS TO LAKE EFFECT/ENHANCEMENT.
COLDER AIR WILL SETTLE IN QUICKLY TODAY AND TONIGHT WITH 850 MB
TEMPS DROPPING TO AROUND 0C. THIS COMBINED WITH LAKE SFC TEMPS IN
THE MID TEENS CELSIUS (ROUGHLY 17 C) WILL ALLOW FOR STRONG
INSTABILITY OVER THE LAKE AND POINTS INLAND (LK-H85 DELTA T`S AROUND
17 AND LK-H7 DELTA T`S PUSHING 30 C BY TONIGHT). DESPITE
THIS...AVAILABLE MSTR MAY BE SOMEWHAT LIMITED WITH SOUTHWARD EXTENT
INTO NW PORTIONS OF THE AREA. ALSO TRAJECTORY WILL BE MORE 230 TO
260 MUCH OF THE PERIOD WITH DEEPER CLOUD LAYER MSTR RESIDING ACROSS
N BERRIEN/NW CASS INTO REMAINDER OF WESTERN LWR MI. HAVE MAINTAINED
LIKELY POPS IN THE BERRIEN/CASS CO AREAS WITH QUICK DROP IN POPS
FURTHER EAST AND SOUTH. CHANCES WILL LINGER INTO AT LEAST THIS
EVENING AND POSSIBLY OVERNIGHT. HOWEVER...DELTA T`S WILL BEGIN TO
DECREASE SOMEWHAT AND FLOW LESS FAVORABLE FOR THE AREA FOR
ADDITIONAL PRECIP.
AWAY FROM THE LAKE AREAS...POTENTIAL DOES EXIST FOR SOME PATCHY
FROST IN MAINLY OUTLYING AREAS AS LOWS DIP INTO THE MID 30S IN MANY
AREAS. WINDS MAY REMAIN JUST STRONG ENOUGH TO KEEP FORMATION LIMITED
WITH FROST CONFINED TO HIGHER SURFACES OR FAVORED DRAINAGE AREAS.
FOR NOW WILL LEAVE MENTION OUT OF FORECAST AND DEFER TO DAY SHIFT TO
MONITOR CLEARING TRENDS AND ANTICIPATED WINDS.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 457 AM EDT SAT OCT 19 2013
SUCCINCT SHARPENING OF MID CANADA/CONUS TROF UNDERWAY WITH CURRENT
SHORTWAVE DIGGING THROUGH WESTERN GREAT LAKES WITH SUBSTANTIVE
BURGEONING BAROCLINIC LEAF SERN MO INTO CENTRAL ILLINOIS. THIS WAVE
TO RAPIDLY TRANSLATE NEWD TO SOUTHEAST ONTARIO BY LATE THIS EVENING.
BUCKLING POSITIVE HEIGHTS SUNDAY AMID PUTRID MOISTURE PROFILES AND
STRONG LOW LEVEL THERMAL PUSH INTO MID MS VLY POINTS TO FINAL DEATH
KNEEL TO PRIOR TOKEN POP MENTION FOR NWRN CWA SUN. A MORE
TIGHTLY PACKED/VIGORED UPSTREAM ENERGY LOBE NOTED IN WV IMAGERY
64N/105W OR JUST NORTH OF MAN/SASK BORDER POISED FOR CROSS
MERIDIONAL FLOW TO DEEPEN WITH MIDLVL SYSTEM DEEPENING INTO WRN
GREAT LAKES SUNDAY NIGHT INTO MONDAY. CONTD SIMILAR THEME WRT POP
COVERAGE LIMITED TO NWRN/NRN CWA IN STRONG LOW LEVEL WAA...WITH BEST
DYNAMICS SHUNTED W-NW-N OF CWA. AND BEST ALBEIT STILL TEMPERED POPS
FOR MONDAY A LA ANAFRONTAL SCENARIO IN TRAILING LOBE OF HEIGHT
FALLS. IT WILL BE THIS SYSTEMS PASSAGE THAT WILL EFFECTIVELY PUT THE
KIBOSH ON THE NOTABLY STRONG/CYCLICAL CAA/WAA LLVL PATTERN
INTERTWIXT BTWN SYSTEMS OF RECENT PAST...AS FINALLY DEEP COLD AIR
BECOMES ENTRENCHED ACROSS GRT LKS REGN. HEREAFTER...STRONG
CONCURRENCE WITH A PRIORI DISCUSSION/GRIDS AS TO INCREASED ACTIVE
LAKE ENHANCED SHRA POTNL WITH 8H/LK THERMAL DIFFERENTIALS INCREASING
TO AROUND 20C. INCREASED CONFIDENCE OF DEEPER COLD PROFILE SUPPORTS
INTRODUCING POTNL FOR LIQUID/FROZEN MIX BY THURSDAY. SOME MINOR
PROBABILISTIC CONCERN FOR FROZEN PTYPE ON WEDNESDAY...THOUGH ONE
PSBL FLY IN THE OINTMENT MAYBE HINTS OF PLAINS TO MID MS VLY CLIPPER
SYSTEM TO DIVE THRU EASTERN PERIPHERY OF BROADLY ARCHED WRN CONUS
RIDGE. THIS SCENARIO SHOULD FAVOR TEMPORARY BACKING CBL
FLOW/INCREASED IN CLOUD SHEAR. THIS ALONG WITH INITIAL WARM SUB
CLOUD REGION...ESPCLY PROXIMAL TO SRN LK MI SHOULD ALLOW FOR
MELT...LENDS TOWARD OMISSION ATTM. GRADUAL THERMAL MODERATION INTO
NEXT WEEKEND AS A TRANSITIONAL PATTERN AND/OR POSSIBLE TEMPORARY
SPLIT FLOW APPEARS FAVORED. DRYING TREND UNTIL GREATER CONFIDENCE OF
NOTEWORTHY SYSTEM POTNL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 133 AM EDT SAT OCT 19 2013
LIFT AHEAD OF SHORT WAVE MOVING TOWARDS THE REGION HAS ALREADY
ALLOWED FOR LARGE AREA OF VRY LGT RAIN/DRIZZLE TO EXPAND ACROSS MUCH
OF CENTRAL ILLINOIS. GIVEN PRESENT TRAJECTORIES HAVE OPTED TO
INCLUDE VFR MENTION OF LIGHT RAIN AT KSBN FOR A FEW HOURS OVERNIGHT
AND THEN IMPROVING CONDITIONS. WILL MONITOR UPSTREAM TRENDS AS
TROUGH AXIS TO THE WEST MAY SHIFT THROUGH FAST ENOUGH TO PUSH PRECIP
EAST OR LINGER LONG ENOUGH IN THE WEST TO ALLOW FOR MORE EXPANSIVE
LIGHT RAIN. AT KFWA...LONGER PERIOD OF LGT RAIN MAY OCCUR BUT STILL
MINIMAL OVERALL IMPACT WITH EXCURSION INTO MVFR RANGE POSSIBLE
TOWARDS 12Z.
WAVE MOVES AWAY BY EARLY AFTERNOON WITH SW/W FLOW SETTING UP ACROSS
THE LAKES TO ALLOW FOR SOME LAKE ENHANCEMENT CLOUDS/LIGHT SHOWERS.
THIS SHOULD REMAIN GENERALLY NORTH OF KSBN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR LMZ043-046.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...FISHER
LONG TERM...MURPHY
AVIATION...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
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WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1111 AM EDT SAT OCT 19 2013
.SYNOPSIS...
ISSUED AT 233 AM EDT SAT OCT 19 2013
AN ACTIVE AND CHILLY PATTERN WILL REMAIN ACROSS THE GREAT LAKES
RIGHT THROUGH NEXT WEEK. THE MOST SIGNIFICANT LOW PRESSURE SYSTEM IN
THE NEAR FUTURE WILL MOVE SOUTHEAST FROM CENTRAL CANADA THIS
WEEKEND...REACHING LAKE SUPERIOR BY MONDAY MORNING. THE COLDEST AIR
OF THE FALL SEASON SO FAR WILL ENTER THE REGION BEHIND THE LOW
PRESSURE SYSTEM. TEMPERATURES MAY GET COLD ENOUGH NEXT WEEK TO BRING
THE FIRST SNOWFALL OF THE SEASON...ESPECIALLY TO THE INTERIOR
HIGHLANDS OF NORTHERN LOWER MICHIGAN.
&&
.UPDATE...
ISSUED AT 1111 AM EDT SAT OCT 19 2013
SHARP SHORT WAVE TROUGH AND FIRST ROUND OF COLDER AIR NOW SWINGING
THROUGH THE WESTERN GREAT LAKES. ASSOCIATED JET CORE AXIS RUNS
NORTHEASTWARD UP THROUGH THE OHIO VALLEY AND ACROSS FAR SE LOWER
MICHIGAN. LEFT EXIT REGION FORCING HELPING TO DEEPEN LOW PRESSURE
OVER NRN LAKE HURON WITH A TRAILING COLD FRONT/SFC TROUGH AXIS
STRETCHING BACK THROUGH NE LOWER MICHIGAN INTO CENTRAL LOWER
MICHIGAN. BATCH OF FAIRLY WIDESPREAD "WRAP AROUND" RAINFALL
MOVING ACROSS NE LOWER MICHIGAN THIS LATE THIS MORNING RIGHT
BEHIND THE FRONT.
FURTHER WEST...WELL DEFINED DRY SLOT/CLEARING LINE POKING UP INTO
THE WESTERN GREAT LAKES AND NOSING INTO EASTERN UPPER/NW LOWER
MICHIGAN.
REST OF TODAY...PER SATELLITE TRENDS...CLEARING LINE WILL WORK ITS
WAY EASTWARD OVER THE NEXT FEW HOURS AS LOW AMPLITUDE LOW-MID
LEVEL RIDGING SLIDES THROUGH THE REGION. THIS WILL BRING VARYING
DEGREES OF SUNSHINE TO THE CWA...AT LEAST FOR A BRIEF PERIOD. BUT
GIVEN THE MAGNITUDE OF COLD AIR AND STEEP LAPSE RATES ALOFT (-2C
AT 850 MB...-30C AT 500 MB LEADING TO 1000-500 MB LAPSE RATES
EXCEEDING 7C/KM) HARD TO IMAGINE WE WONT SEE ANOTHER BATCH OF
SHOWERS DEVELOP THIS AFTERNOON...EITHER UPSTREAM OVER EASTERN
WISCONSIN AND/OR OVER THE LAKE MICHIGAN/NW LOWER MICHIGAN WITHIN
THE LAKE "HEAT PLUME." HAVE SCT-LIKELY SHOWERS IN THE FORECAST
DEVELOPING OVER THE WESTERN PARTS OF THE CWA THIS AFTERNOON INTO
THIS EVENING AS A RESULT.
THUNDER AND SMALL HAIL...NOT OUT OF THE QUESTION GIVEN THE STEEP
LAPSE RATES AND EQUILIBRIUM LEVELS POKING ABOVE -20C.
UPDATE ISSUED AT 651 AM EDT SAT OCT 19 2013
SHOWERS HAVE BEEN SLOW ALL NIGHT TO MOVE INLAND FROM LAKE MI...AND
THAT TREND CONTINUES...THOUGH THERE IS SOMETHING OF A BACK EDGE
PRESSING EASTWARD WEST OF CAD/TVC. HAVE ADJUSTED POP/WX GRIDS THIS
MORNING TO ACCOUNT.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 233 AM EDT SAT OCT 19 2013
FIRST ROUND OF A STEP DOWN PROCESS TO A MUCH COOLER WEATHER REGIME
FIRMLY IN CONTROL OF OUR WEATHER AT THIS EARLY HOUR...COURTESY OF
OVERHEAD TROUGHING IN A REMARKABLY AMPLIFIED NOAM FLOW REGIME.
LATEST RAP HIGH RES ANALYSIS CONFIRMS...WITH H8 TEMPERATURES DIPPING
TO SUB 0C LEVELS ACROSS THE NORTHWEST HALF OF THE AREA. DESPITE
OVERHEAD TROUGHING...MID LEVEL SYNOPTIC DYNAMICS RATHER
NEGLIGIBLE...WITH FIRST WAVE (RESPONSIBLE FOR YESTERDAY`S CONVECTIVE
ACTIVITY) OFF TO OUR NORTHEAST...WITH STRONGER CORE OF MID LEVEL
SUPPORT PINWHEELING IN BASE OF TROUGH AXIS WELL TO OUR SOUTHWEST.
LOW LEVEL FEATURES SOMEWHAT MORE FOCUSED...WITH SURFACE TROUGHING
EXTENDING NORTHEAST TO SOUTHWEST...ESSENTIALLY BISECTING NORTHERN
LOWER MICHIGAN...WITH NOTED H8 TROUGHING JUST OFFSET TO THE WEST OF
THIS SURFACE FRONT. COMBINATION OF ATTENDANT FORCED LOW LEVEL
CONVERGENCE AND FAVORABLE LAKE PROCESSES CONTINUE TO KICK OFF
POCKETS OF SHOWERS...SOME OF WHICH HAVE BEEN LOCALLY HEAVY...
ESPECIALLY ALONG THE LAKE MICHIGAN SHORELINE. SURFACE TEMPERATURES
STILL IN THE 40S AND SURFACE BASED MELTING LAYER AT OR ABOVE 2 KFT
LEADING TO ALL LIQUID SHOWERS. SHORT TERM FORECAST CONCERNS REMAIN
CENTERED ON ADDITIONAL SHOWER POTENTIAL RIGHT THROUGH TONIGHT...AS
WELL AS ADDRESSING THUNDER AND WATERSPOUT CHANCES INTO THIS
EVENING.
REALLY KINDA A LOW CONFIDENCE ENDEAVOR ON FORECASTING SHOWER
EVOLUTION TODAY. NO DOUBT THERMODYNAMIC PROFILES REMAIN VERY
SUPPORTIVE FOR ADDITIONAL LAKE PROCESSES...WITH H8 TEMPERATURES
HOVERING AROUND -2C AND LAKE INDUCED EQUILIBRIUM LEVELS UP AND OVER
20 KFT (LAKE INDUCED CAPE OF AROUND 1.0 J/KG). THAT SAID...
KINEMATICS AND OVERALL SYNOPTIC BACKGROUND SUPPORT NOT NEARLY AS
FAVORABLE FOR WIDESPREAD ORGANIZED LAKE INDUCED SHOWERS. WIND FIELDS
RIGHT UP THROUGH 15 KFT REMAIN RATHER LIGHT AND DISORGANIZED...WITH
LOW LEVEL WINDS STEADILY BACKING THROUGH THE DAY AHEAD OF NEXT
APPROACHING SHORTWAVE TROUGH AND ATTENDANT SURFACE REFLECTION. MAIN
CORE OF ENERGY CURRENTLY TIED TO BASE OF TROUGH AXIS LOOKS TO SLIDE
JUST OFF TO OUR SOUTHEAST...LIKELY NOT HAVING A SIGNIFICANT EFFECT
ON LAKE PROCESS MORPHOLOGY (MAY INCREASE THE ODDS FOR MORE FOCUSED
SHOWERS ACROSS NORTHEAST LOWER THIS MORNING). COMBINE ABOVE WITH
TERRESTRIAL CAPE DEVELOPMENT SIMPLY OVERWHELMING LIMITED CBL
SHEAR...RESULTING IN A DEFINITE CELLULAR COMPONENT TO LAKE SHOWER
ACTIVITY...AND ONE CAN SEE WHY SHOWER COVERAGE REMAINS QUITE
PROBLEMATIC TODAY. SHOWERS WILL NO DOUBT CONTINUE...BUT WILL CONFINE
BETTER COVERAGE CLOSER TO THE LAKE MICHIGAN SHORELINE...WITH BELIEF
OVERALL AREAL COVERAGE WILL DISSIPATE AS THEY MOVE INLAND. SURFACE
BASED CAPE AND H5 TEMPERATURES DIPPING TO -30C WILL DEFINITELY AID
IN AN OVERLAND SHOWER COMPONENT...AND MUCH LIKE YESTERDAY...AN
ISOLATED THUNDERSTORM OR TWO. DEEP MOIST CONVECTION IN SUCH A COLD
ENVIRONMENT WILL DEFINITELY SUPPORT THE THREAT OF BRIEF GRAUPEL
SHOWERS UNDER THE HEAVIER PRECIP CORES. HIGHS TODAY WILL RUN A FEW
DEGREES BELOW NORMAL...WITH AFTERNOON READINGS IN THE 40S AND LOWER
50S.
LAKE PROCESSES LIKELY TO GET A BOOST HEADING INTO THIS EVENING AS
WEAK WAVE AND SURFACE TROUGH/ATTENDANT CORE OF LOW LEVEL CONVERGENCE
CROSS LAKE MICHIGAN. MAY SEE SOME PRETTY HEAVY SHOWERS ALONG THIS
TROUGH AS IT PUSHES ONSHORE...WITH SHOWER COVERAGE ONCE AGAIN
DISSIPATING AS THEY PUSH INLAND. GIVEN MAINTENANCE OF DEEP EQL/S AND
GOOD OVER-WATER CAPE...WILL CONTINUE THUNDER MENTION INTO THIS
EVENING OVER AND NEAR LAKE MICHIGAN. LAKE ENHANCEMENT/SHOWER
COVERAGE BOTH EXPECTED TO DISSIPATE OVERNIGHT AS POST-WAVE
SUBSIDENCE REGIME SPREADS ACROSS AND MOISTURE PROFILES BEGIN TO
THIN.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 233 AM EDT SAT OCT 19 2013
UPPER FLOW IS ANCHORED BY RIDGING ALONG OR JUST OFF THE WEST
COAST...AND BROAD RIDGING IN THE CENTRAL ATLANTIC. IN BETWEEN...
TROFFING REIGNS SUPREME OVER CENTRAL CANADA AND ADJOINING PARTS OF
THE US. THIS PATTERN WILL KEEP NORTHERN MI WX COOL AND UNSETTLED FOR
QUITE SOME TIME. THE REAL FUN ARRIVES TOWARD THE EARLY PART OF NEXT
WEEK...AS THE UPPER LOW NOW OVER NW HUDSON BAY DROPS SOUTHWARD INTO
THE NORTHERN GREAT LAKES. PRECIP TRENDS ARE THE MAIN CONCERN THRU
THE FORECAST.
SUNDAY LOOKS LIKE A /RELATIVE/ LULL IN THE SHOWER ACTIVITY. AS THE
UPPER TROF OVER NORTHERN MI TODAY DEPARTS THE EASTERN LAKES...AND AS
THE NEXT LOW DROPS SOUTH ACROSS MANITOBA...A BIT OF SHORTWAVE
RIDGING GETS PUMPED UP INTO THE CENTRAL/NORTHERN LAKES. SUBTLE
SURFACE RIDGING POKES NORTH TOWARD LAKE HURON AT MIDDAY...THEN MOVES
EAST AS RETURN FLOW RAMPS UP LATE IN THE DAY. THOUGH DEEPER DRYING
IS ARRIVING (850-700MB RH LOWERING BELOW 60 PERCENT)...WITH 850MB
TEMPS -2 TO -3C...WOULD STILL EXPECT AT LEAST SCT SHRA IN THE
MORNING IN W TO WSW FLOW AREAS (MAINLY NW LOWER). MAY CATCH A BIT OF
A PRECIP BREAK MIDDAY TO MID AFTERNOON. AFTER THAT...THE NAM MAY BE
OVERDONE IN DEVELOPING A 45KT 850MB JET PUNCHING UP THE SPINE OF
CENTRAL/SOUTHERN LAKE MI. BUT INCREASING RETURN FLOW WARRANTS A
CHANCE OF SHRA RETURNING VERY LATE IN THE DAY IN SOME WESTERN
SECTIONS. MAX TEMPS NEAR 50 TO THE LOWER 50S.
SUN NIGHT/MONDAY...500MB LOW WILL CONTINUE TO DROP TOWARD INTL FALLS
BY MONDAY MORNING...THEN PIVOT TOWARD CENTRAL LAKE SUPERIOR BY
EVENING. THE ASSOCIATED SURFACE LOW WILL DEEPEN TO AROUND 998MB OVER
CENTRAL SUPERIOR BY MORNING MORNING...THEN FILL A BIT AND ELONGATE
TOWARD THE ENE DURING THE DAY.
ON SUNDAY NIGHT...RAIN WILL SPREAD ENE-WARD FROM NORTHERN/CENTRAL
WI...INITIALLY MAINLY NORTH OF A WARM FRONT THAT LIFTS INTO FAR
NORTHERN LOWER MI BY 06Z. THAT FRONT LIFTS ACROSS EASTERN UPPER MI
OVERNIGHT...BUT THE COLD FRONT IS RIGHT BEHIND...CROSSING MOST OF
THE FORECAST AREA FROM WEST TO EAST. THIS BOUNDARY MAY STILL BE
HANGING AROUND EXTREME EASTERN SECTIONS (OSC-APN-DRUMMOND) AT 12Z.
POPS WILL BE HIGHEST NORTH OF A TVC-APN LINE...WHERE THE LOW LEVEL
JET (850MB WINDS PUSHING 50-55KT AT 03Z) PUNCHES ACROSS THE
ADVANCING WARM FRONT. POPS DIMINISH TO CHANCE IN THE FAR SE.
MONDAY IS A DAY DOMINATED BY MID/UPPER-LEVEL DRY SLOTTING...AS THE
WARM CONVEYOR BELT RACES EAST...AND WRAPAROUND MOISTURE REMAINS BACK
ALONG THE WESTERN AND NORTHERN SHORES OF SUPERIOR. HOWEVER...A
SUBSTANTIAL QUANTITY OF COLD AIR WILL BE PUSHING IN AS THE DAY
PROCEEDS. 850MB TEMPS WILL BE IN THE PROCESS OF SLIDING BACK TO OR
BELOW 0C BY 12Z...READINGS CLOSER TO -6C ARE PROGGED BY SUNSET. THE
INCREASING INSTABILITY SHOULD FIGHT OFF THE DRIER AIR ALOFT...AND
SUPPORT AT LEAST SOME SHRA DOWNWIND OF THE LAKES. WHERE EXACTLY THAT
IT IS STILL CONJECTURE...AS DIFFERENT ORIENTATIONS OF THE SURFACE
LOW TO OUR RESULTS IN DIFFERENT FETCHES (FROM W TO SW). WILL SPLIT
THE DIFFERENCE FOR NOW.
MIN TEMPS NEAR 40F TO THE LOWER 40S. MAX TEMPS ONLY 5F WARMER THAN
THAT WEST...10F EAST...WITH FALLING READINGS IN THE PM. BRISK/WINDY
ON MONDAY.
REST OF THE FORECAST...NO MAJOR CHANGES TO THE EXTENDED.
UNSEASONABLY COOL WX WILL CONTINUE. THOUGH THE UPPER LOW ITSELF WILL
LIFT OUT INTO QUEBEC ON TUESDAY/WEDNESDAY...PLENTY OF TROFFING GETS
LEFT BEHIND. OCCASIONAL REINFORCING SHORTWAVES FROM THE NNW WILL
REINFORCE THE TROFFING...AND THE COLDER AIR AT LOW LEVELS. LAKE
EFFECT SHOWERS WILL CONTINUE DOWNWIND OF THE LAKES...AND MAINTAINED
LIKELY POPS IN THE CLASSIC SNOWBELTS. SPEAKING OF SNOW...PRECIP WILL
GET MIXY TO SNOWY AT TIMES...ESPECIALLY AT NIGHT/MORNING AND
ESPECIALLY IN THE HIGH TERRAIN OF NORTHERN LOWER. THOUGH QUITE
UNCERTAIN WHETHER THIS WILL EVER RISE TO THE LEVEL OF A WINTER WX
HEADLINE...THE MENTION OF THE FIRST SNOW OF THE SEASON PRESENTLY IN
THE HAZ WX OUTLOOK IS REASONABLE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 651 AM EDT SAT OCT 19 2013
LOW VFR/HIGH MVFR CIGS WILL PERSIST ACROSS MOST OF NRN LWR MICHIGAN
THRU TONIGHT...AS NMRS LAKE ENHANCED RAIN SHOWERS CONTINUE TO
STREAM INTO THE REGION. NW LWR MICHIGAN (PLN/TVC/MBL) WILL SEE
THE MOST FREQUENT SHOWER ACTIVITY. LOW LEVEL WINDS WILL BACK TO
THE WEST BY MIDDAY SATURDAY AHEAD OF THE NEXT WAVE OF LOW PRESSURE
AS A DEEP 500 MB TROUGH DIGS INTO THE UPPER MISSISSIPPI VALLEY.
&&
.MARINE...
ISSUED AT 233 AM EDT SAT OCT 19 2013
BIG STORY REMAINS ISOLATED WATERSPOUT POTENTIAL TODAY INTO
THIS EVENING. COMBINATION OF UNSEASONABLY CHILLY AIRMASS/WEAK
PARTIALLY LAKE-DRIVEN SURFACE TROUGH/AND DEEP CONVECTION DEFINITELY
SUPPORT THIS POTENTIAL. PRIMARY THREAT IS EXPECTED ACROSS THE WATERS
OF LAKE MICHIGAN AND LAKE HURON...WITH THE THREAT ENDING OVERNIGHT
AS THE SURFACE TROUGH PASSES. OTHERWISE...MARGINALLY GUSTY GENERAL
WEST FLOW TODAY...ALTHOUGH BOTH WINDS AND WAVES LOOK TO REMAIN BELOW
SCA CRITERIA. WINDS BEGIN TO PICK UP OUT OF THE SOUTHEAST
SUNDAY...BECOMING QUITE GUSTY SUNDAY NIGHT. WINDS VEER SOUTHWEST ON
MONDAY BEHIND PASSAGE OF A STRONG COLD FRONT. HEADLINES WILL
EVENTUALLY BE NEED FOR THE WATERS LATER SUNDAY RIGHT THROUGH MONDAY
(AND LIKELY BEYOND). MAY EVEN SEE GALE CONDITIONS ON NORTHERN LAKE
MICHIGAN ON MONDAY AS STRONG LOW PRESSURE PULLS UP ACROSS LAKE
SUPERIOR.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...BA
SYNOPSIS...JZ
SHORT TERM...MB
LONG TERM...JZ
AVIATION...JZ
MARINE...MB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
652 AM EDT SAT OCT 19 2013
.SYNOPSIS...
ISSUED AT 233 AM EDT SAT OCT 19 2013
AN ACTIVE AND CHILLY PATTERN WILL REMAIN ACROSS THE GREAT LAKES
RIGHT THROUGH NEXT WEEK. THE MOST SIGNIFICANT LOW PRESSURE SYSTEM IN
THE NEAR FUTURE WILL MOVE SOUTHEAST FROM CENTRAL CANADA THIS
WEEKEND...REACHING LAKE SUPERIOR BY MONDAY MORNING. THE COLDEST AIR
OF THE FALL SEASON SO FAR WILL ENTER THE REGION BEHIND THE LOW
PRESSURE SYSTEM. TEMPERATURES MAY GET COLD ENOUGH NEXT WEEK TO BRING
THE FIRST SNOWFALL OF THE SEASON...ESPECIALLY TO THE INTERIOR
HIGHLANDS OF NORTHERN LOWER MICHIGAN.
&&
.UPDATE...
ISSUED AT 651 AM EDT SAT OCT 19 2013
SHOWERS HAVE BEEN SLOW ALL NIGHT TO MOVE INLAND FROM LAKE MI...AND
THAT TREND CONTINUES...THOUGH THERE IS SOMETHING OF A BACK EDGE
PRESSING EASTWARD WEST OF CAD/TVC. HAVE ADJUSTED POP/WX GRIDS THIS
MORNING TO ACCOUNT.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 233 AM EDT SAT OCT 19 2013
FIRST ROUND OF A STEP DOWN PROCESS TO A MUCH COOLER WEATHER REGIME
FIRMLY IN CONTROL OF OUR WEATHER AT THIS EARLY HOUR...COURTESY OF
OVERHEAD TROUGHING IN A REMARKABLY AMPLIFIED NOAM FLOW REGIME.
LATEST RAP HIGH RES ANALYSIS CONFIRMS...WITH H8 TEMPERATURES DIPPING
TO SUB 0C LEVELS ACROSS THE NORTHWEST HALF OF THE AREA. DESPITE
OVERHEAD TROUGHING...MID LEVEL SYNOPTIC DYNAMICS RATHER
NEGLIGIBLE...WITH FIRST WAVE (RESPONSIBLE FOR YESTERDAY`S CONVECTIVE
ACTIVITY) OFF TO OUR NORTHEAST...WITH STRONGER CORE OF MID LEVEL
SUPPORT PINWHEELING IN BASE OF TROUGH AXIS WELL TO OUR SOUTHWEST.
LOW LEVEL FEATURES SOMEWHAT MORE FOCUSED...WITH SURFACE TROUGHING
EXTENDING NORTHEAST TO SOUTHWEST...ESSENTIALLY BISECTING NORTHERN
LOWER MICHIGAN...WITH NOTED H8 TROUGHING JUST OFFSET TO THE WEST OF
THIS SURFACE FRONT. COMBINATION OF ATTENDANT FORCED LOW LEVEL
CONVERGENCE AND FAVORABLE LAKE PROCESSES CONTINUE TO KICK OFF
POCKETS OF SHOWERS...SOME OF WHICH HAVE BEEN LOCALLY HEAVY...
ESPECIALLY ALONG THE LAKE MICHIGAN SHORELINE. SURFACE TEMPERATURES
STILL IN THE 40S AND SURFACE BASED MELTING LAYER AT OR ABOVE 2 KFT
LEADING TO ALL LIQUID SHOWERS. SHORT TERM FORECAST CONCERNS REMAIN
CENTERED ON ADDITIONAL SHOWER POTENTIAL RIGHT THROUGH TONIGHT...AS
WELL AS ADDRESSING THUNDER AND WATERSPOUT CHANCES INTO THIS
EVENING.
REALLY KINDA A LOW CONFIDENCE ENDEAVOR ON FORECASTING SHOWER
EVOLUTION TODAY. NO DOUBT THERMODYNAMIC PROFILES REMAIN VERY
SUPPORTIVE FOR ADDITIONAL LAKE PROCESSES...WITH H8 TEMPERATURES
HOVERING AROUND -2C AND LAKE INDUCED EQUILIBRIUM LEVELS UP AND OVER
20 KFT (LAKE INDUCED CAPE OF AROUND 1.0 J/KG). THAT SAID...
KINEMATICS AND OVERALL SYNOPTIC BACKGROUND SUPPORT NOT NEARLY AS
FAVORABLE FOR WIDESPREAD ORGANIZED LAKE INDUCED SHOWERS. WIND FIELDS
RIGHT UP THROUGH 15 KFT REMAIN RATHER LIGHT AND DISORGANIZED...WITH
LOW LEVEL WINDS STEADILY BACKING THROUGH THE DAY AHEAD OF NEXT
APPROACHING SHORTWAVE TROUGH AND ATTENDANT SURFACE REFLECTION. MAIN
CORE OF ENERGY CURRENTLY TIED TO BASE OF TROUGH AXIS LOOKS TO SLIDE
JUST OFF TO OUR SOUTHEAST...LIKELY NOT HAVING A SIGNIFICANT EFFECT
ON LAKE PROCESS MORPHOLOGY (MAY INCREASE THE ODDS FOR MORE FOCUSED
SHOWERS ACROSS NORTHEAST LOWER THIS MORNING). COMBINE ABOVE WITH
TERRESTRIAL CAPE DEVELOPMENT SIMPLY OVERWHELMING LIMITED CBL
SHEAR...RESULTING IN A DEFINITE CELLULAR COMPONENT TO LAKE SHOWER
ACTIVITY...AND ONE CAN SEE WHY SHOWER COVERAGE REMAINS QUITE
PROBLEMATIC TODAY. SHOWERS WILL NO DOUBT CONTINUE...BUT WILL CONFINE
BETTER COVERAGE CLOSER TO THE LAKE MICHIGAN SHORELINE...WITH BELIEF
OVERALL AREAL COVERAGE WILL DISSIPATE AS THEY MOVE INLAND. SURFACE
BASED CAPE AND H5 TEMPERATURES DIPPING TO -30C WILL DEFINITELY AID
IN AN OVERLAND SHOWER COMPONENT...AND MUCH LIKE YESTERDAY...AN
ISOLATED THUNDERSTORM OR TWO. DEEP MOIST CONVECTION IN SUCH A COLD
ENVIRONMENT WILL DEFINITELY SUPPORT THE THREAT OF BRIEF GRAUPEL
SHOWERS UNDER THE HEAVIER PRECIP CORES. HIGHS TODAY WILL RUN A FEW
DEGREES BELOW NORMAL...WITH AFTERNOON READINGS IN THE 40S AND LOWER
50S.
LAKE PROCESSES LIKELY TO GET A BOOST HEADING INTO THIS EVENING AS
WEAK WAVE AND SURFACE TROUGH/ATTENDANT CORE OF LOW LEVEL CONVERGENCE
CROSS LAKE MICHIGAN. MAY SEE SOME PRETTY HEAVY SHOWERS ALONG THIS
TROUGH AS IT PUSHES ONSHORE...WITH SHOWER COVERAGE ONCE AGAIN
DISSIPATING AS THEY PUSH INLAND. GIVEN MAINTENANCE OF DEEP EQL/S AND
GOOD OVER-WATER CAPE...WILL CONTINUE THUNDER MENTION INTO THIS
EVENING OVER AND NEAR LAKE MICHIGAN. LAKE ENHANCEMENT/SHOWER
COVERAGE BOTH EXPECTED TO DISSIPATE OVERNIGHT AS POST-WAVE
SUBSIDENCE REGIME SPREADS ACROSS AND MOISTURE PROFILES BEGIN TO
THIN.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 233 AM EDT SAT OCT 19 2013
UPPER FLOW IS ANCHORED BY RIDGING ALONG OR JUST OFF THE WEST
COAST...AND BROAD RIDGING IN THE CENTRAL ATLANTIC. IN BETWEEN...
TROFFING REIGNS SUPREME OVER CENTRAL CANADA AND ADJOINING PARTS OF
THE US. THIS PATTERN WILL KEEP NORTHERN MI WX COOL AND UNSETTLED FOR
QUITE SOME TIME. THE REAL FUN ARRIVES TOWARD THE EARLY PART OF NEXT
WEEK...AS THE UPPER LOW NOW OVER NW HUDSON BAY DROPS SOUTHWARD INTO
THE NORTHERN GREAT LAKES. PRECIP TRENDS ARE THE MAIN CONCERN THRU
THE FORECAST.
SUNDAY LOOKS LIKE A /RELATIVE/ LULL IN THE SHOWER ACTIVITY. AS THE
UPPER TROF OVER NORTHERN MI TODAY DEPARTS THE EASTERN LAKES...AND AS
THE NEXT LOW DROPS SOUTH ACROSS MANITOBA...A BIT OF SHORTWAVE
RIDGING GETS PUMPED UP INTO THE CENTRAL/NORTHERN LAKES. SUBTLE
SURFACE RIDGING POKES NORTH TOWARD LAKE HURON AT MIDDAY...THEN MOVES
EAST AS RETURN FLOW RAMPS UP LATE IN THE DAY. THOUGH DEEPER DRYING
IS ARRIVING (850-700MB RH LOWERING BELOW 60 PERCENT)...WITH 850MB
TEMPS -2 TO -3C...WOULD STILL EXPECT AT LEAST SCT SHRA IN THE
MORNING IN W TO WSW FLOW AREAS (MAINLY NW LOWER). MAY CATCH A BIT OF
A PRECIP BREAK MIDDAY TO MID AFTERNOON. AFTER THAT...THE NAM MAY BE
OVERDONE IN DEVELOPING A 45KT 850MB JET PUNCHING UP THE SPINE OF
CENTRAL/SOUTHERN LAKE MI. BUT INCREASING RETURN FLOW WARRANTS A
CHANCE OF SHRA RETURNING VERY LATE IN THE DAY IN SOME WESTERN
SECTIONS. MAX TEMPS NEAR 50 TO THE LOWER 50S.
SUN NIGHT/MONDAY...500MB LOW WILL CONTINUE TO DROP TOWARD INTL FALLS
BY MONDAY MORNING...THEN PIVOT TOWARD CENTRAL LAKE SUPERIOR BY
EVENING. THE ASSOCIATED SURFACE LOW WILL DEEPEN TO AROUND 998MB OVER
CENTRAL SUPERIOR BY MORNING MORNING...THEN FILL A BIT AND ELONGATE
TOWARD THE ENE DURING THE DAY.
ON SUNDAY NIGHT...RAIN WILL SPREAD ENE-WARD FROM NORTHERN/CENTRAL
WI...INITIALLY MAINLY NORTH OF A WARM FRONT THAT LIFTS INTO FAR
NORTHERN LOWER MI BY 06Z. THAT FRONT LIFTS ACROSS EASTERN UPPER MI
OVERNIGHT...BUT THE COLD FRONT IS RIGHT BEHIND...CROSSING MOST OF
THE FORECAST AREA FROM WEST TO EAST. THIS BOUNDARY MAY STILL BE
HANGING AROUND EXTREME EASTERN SECTIONS (OSC-APN-DRUMMOND) AT 12Z.
POPS WILL BE HIGHEST NORTH OF A TVC-APN LINE...WHERE THE LOW LEVEL
JET (850MB WINDS PUSHING 50-55KT AT 03Z) PUNCHES ACROSS THE
ADVANCING WARM FRONT. POPS DIMINISH TO CHANCE IN THE FAR SE.
MONDAY IS A DAY DOMINATED BY MID/UPPER-LEVEL DRY SLOTTING...AS THE
WARM CONVEYOR BELT RACES EAST...AND WRAPAROUND MOISTURE REMAINS BACK
ALONG THE WESTERN AND NORTHERN SHORES OF SUPERIOR. HOWEVER...A
SUBSTANTIAL QUANTITY OF COLD AIR WILL BE PUSHING IN AS THE DAY
PROCEEDS. 850MB TEMPS WILL BE IN THE PROCESS OF SLIDING BACK TO OR
BELOW 0C BY 12Z...READINGS CLOSER TO -6C ARE PROGGED BY SUNSET. THE
INCREASING INSTABILITY SHOULD FIGHT OFF THE DRIER AIR ALOFT...AND
SUPPORT AT LEAST SOME SHRA DOWNWIND OF THE LAKES. WHERE EXACTLY THAT
IT IS STILL CONJECTURE...AS DIFFERENT ORIENTATIONS OF THE SURFACE
LOW TO OUR RESULTS IN DIFFERENT FETCHES (FROM W TO SW). WILL SPLIT
THE DIFFERENCE FOR NOW.
MIN TEMPS NEAR 40F TO THE LOWER 40S. MAX TEMPS ONLY 5F WARMER THAN
THAT WEST...10F EAST...WITH FALLING READINGS IN THE PM. BRISK/WINDY
ON MONDAY.
REST OF THE FORECAST...NO MAJOR CHANGES TO THE EXTENDED.
UNSEASONABLY COOL WX WILL CONTINUE. THOUGH THE UPPER LOW ITSELF WILL
LIFT OUT INTO QUEBEC ON TUESDAY/WEDNESDAY...PLENTY OF TROFFING GETS
LEFT BEHIND. OCCASIONAL REINFORCING SHORTWAVES FROM THE NNW WILL
REINFORCE THE TROFFING...AND THE COLDER AIR AT LOW LEVELS. LAKE
EFFECT SHOWERS WILL CONTINUE DOWNWIND OF THE LAKES...AND MAINTAINED
LIKELY POPS IN THE CLASSIC SNOWBELTS. SPEAKING OF SNOW...PRECIP WILL
GET MIXY TO SNOWY AT TIMES...ESPECIALLY AT NIGHT/MORNING AND
ESPECIALLY IN THE HIGH TERRAIN OF NORTHERN LOWER. THOUGH QUITE
UNCERTAIN WHETHER THIS WILL EVER RISE TO THE LEVEL OF A WINTER WX
HEADLINE...THE MENTION OF THE FIRST SNOW OF THE SEASON PRESENTLY IN
THE HAZ WX OUTLOOK IS REASONABLE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 651 AM EDT SAT OCT 19 2013
LOW VFR/HIGH MVFR CIGS WILL PERSIST ACROSS MOST OF NRN LWR MICHIGAN
THRU TONIGHT...AS NMRS LAKE ENHANCED RAIN SHOWERS CONTINUE TO
STREAM INTO THE REGION. NW LWR MICHIGAN (PLN/TVC/MBL) WILL SEE
THE MOST FREQUENT SHOWER ACTIVITY. LOW LEVEL WINDS WILL BACK TO
THE WEST BY MIDDAY SATURDAY AHEAD OF THE NEXT WAVE OF LOW PRESSURE
AS A DEEP 500 MB TROUGH DIGS INTO THE UPPER MISSISSIPPI VALLEY.
&&
.MARINE...
ISSUED AT 233 AM EDT SAT OCT 19 2013
BIG STORY REMAINS ISOLATED WATERSPOUT POTENTIAL TODAY INTO
THIS EVENING. COMBINATION OF UNSEASONABLY CHILLY AIRMASS/WEAK
PARTIALLY LAKE-DRIVEN SURFACE TROUGH/AND DEEP CONVECTION DEFINITELY
SUPPORT THIS POTENTIAL. PRIMARY THREAT IS EXPECTED ACROSS THE WATERS
OF LAKE MICHIGAN AND LAKE HURON...WITH THE THREAT ENDING OVERNIGHT
AS THE SURFACE TROUGH PASSES. OTHERWISE...MARGINALLY GUSTY GENERAL
WEST FLOW TODAY...ALTHOUGH BOTH WINDS AND WAVES LOOK TO REMAIN BELOW
SCA CRITERIA. WINDS BEGIN TO PICK UP OUT OF THE SOUTHEAST
SUNDAY...BECOMING QUITE GUSTY SUNDAY NIGHT. WINDS VEER SOUTHWEST ON
MONDAY BEHIND PASSAGE OF A STRONG COLD FRONT. HEADLINES WILL
EVENTUALLY BE NEED FOR THE WATERS LATER SUNDAY RIGHT THROUGH MONDAY
(AND LIKELY BEYOND). MAY EVEN SEE GALE CONDITIONS ON NORTHERN LAKE
MICHIGAN ON MONDAY AS STRONG LOW PRESSURE PULLS UP ACROSS LAKE
SUPERIOR.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JZ
SYNOPSIS...JZ
SHORT TERM...MB
LONG TERM...JZ
AVIATION...JZ
MARINE...MB
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1015 AM EDT SAT OCT 19 2013
.SYNOPSIS...
A WEAK SURFACE WAVE OF LOW PRESSURE WILL TRACK NORTH ALONG A STALLED
FRONTAL ZONE DRAPED ACROSS THE SOUTHEAST/NC COAST THIS MORNING. A
STRONGER SECONDARY COLD FRONT WILL CROSS THE REGION LATE THIS
EVENING. WEAK HIGH PRESSURE WILL BUILD OVER THE AREA THROUGH EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM SATURDAY...
THROUGH THIS EVENING...
20-30KT OF 925/850MB FLOW AND WEAK ISENTROPIC LIFT BETWEEN A COASTAL
FRONT AND AN 850MB FRONT OVER THE WESTERN PIEDMONT CONTINUES TO
SUPPORT AREAS OF LIGHT RAIN THIS MORNING...MAINLY OVER THE FOOTHILLS
AND WESTERN PIEDMONT. UPPER DIVERGENCE ASSOCIATED WITH THE RIGHT
ENTRANCE REGION OF A 150KT 300MB JET WEST OF THE MOUNTAINS SHOULD
OFFER ADDITIONAL LIFT THROUGH THIS AFTERNOON...WHILE THE MAIN AXIS
OF DEEP MOISTURE SHIFTS EASTWARD ACROSS THE CWA AHEAD OF AN UPPER
TROUGH THAT WILL BEGIN TO LIFT OUT OF THE MID MISSISSIPPI VALLEY
REGION. MODELS STILL SHOW QUITE A BIT OF DRYING CENTERED AROUND
850MB AFTER 18Z AS THE FLOW VEERS TO A BIT MORE
WEST-SOUTHWESTERLY...WHICH SHOULD EFFECTIVELY SHUT OFF THE LIGHT
PRECIP...EVEN AS THE NORTHWESTERN PORTION OF THE CWA GETS A GLANCING
BLOW OF 60M HEIGHT FALLS AND THE COLD FRONT ENTERS THE AREA FROM THE
WEST. WILL EXTEND A CHANCE POP INTO THE AFTERNOON BEFORE BRINGING
POPS TO AN END FROM WEST TO EAST THIS EVENING WITH THE IMPENDING
FRONTAL PASSAGE.
THE LIGHT RAIN OVERNIGHT HAS LEFT A WEAK STABLE LAYER NEAR THE
SURFACE AND WIDESPREAD LOW STRATUS. DRY AIR ADVECTING IN FROM THE
SOUTHWEST WILL SLOWLY ERODE THE LOW CLOUDS TODAY...BUT EXPECT THE
LOW CLOUDS WILL LINGER INTO THE AFTERNOON WITHOUT A SIGNIFICANT
EROSION MECHANISM PRIOR TO THE COLD FRONT THIS EVENING. EVEN AS THE
LOW CLOUDS BREAK...THERE WILL ABUNDANT MID AND HIGH CLOUDS TO TEMPER
HIGHS. THE LATEST RAP RUNS APPEAR TO HAVE A BETTER HANDLE OF
THIS...SO HAVE ADJUSTED TEMPS TOWARD THE RAP AND LOCAL WRF
ARW...WHICH SHOW A SLOW WARMING TREND THROUGH EARLY AFTERNOON.
HIGHS SHOULD END UP IN THE MID 60S ACROSS THE NORTHERN AREAS AND
POSSIBLE THE LOWER 70S ACROSS THE SOUTH. -SMITH
TONIGHT...
SHEARED SHORTWAVE TROUGH LIFTING NEWD INTO THE GREAT LAKES
AND NORTHEAST WILL DRAG THE TRAILING SFC COLD FRONT ACROSS THE THE
MOUNTAINS LATE THIS AFTERNOON AND ACROSS CENTRAL NC THIS EVENING
BETWEEN 00 TO 06Z. LIMITED MOISTURE...WEAK FORCING AND THE LACK OF
INSTABILITY WILL PREEMPT ANY PRECIP WITH DRY COLD AIR ADVECTION FOR
THE SECOND HALF OF THE NIGHT SPREADING WEST TO EAST. MUCH COOLER
WITH LOWS RANGING FROM MID 40S NW TO LOWER 50S SE. -CBL
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 240 AM SATURDAY...
POST-FRONTAL CAA REGIME SUNDAY MORNING WILL RESULT IN
LOW-LEVEL THICKNESSES STARTING OUT A GOOD 30 METERS BELOW
NORMAL...MORE REPRESENTATIVE OF LATE NOVEMBER THAN LATE OCTOBER.
IN-HOUSE TEMPERATURE FORECASTING TECHNIQUES ARE A GOOD 4 TO 6
DEGREES COOLER THAN MOS STATISTICAL GUIDANCE WITH FORECAST HIGHS ON
SUNDAY. UNDER COMPLIMENTS OF FULL SUNSHINE...EXPECT AFTERNOON HIGHS
IN THE LOWER TO MID 60S ACROSS THE PIEDMONT/NORTHERN COASTAL
PLAIN...TO MID/UPPER 60S SOUTH.
UPPER HEIGHTS LEVEL OUT A BIT OVER THE REGION AS LONG WAVE TROUGH
CENTERED BACK OVER THE CENTRAL US AWAITS RE-LOADING FROM A
SUCCESSION OF BOTH PACIFIC NW AND CANADIAN S/W ENERGY DIVING SEWD
THROUGH THE NATIONS MID-SECTION. THUS...SWLY FLOW ALOFT WILL
CONTINUE WITH LATEST GFS SHOWING A RESURGENCE OF HIGH-LEVEL MOISTURE
BACK ACROSS THE AREA LATE SUNDAY NIGHT...ESPECIALLY ACROSS THE
SOUTHERN HALF. WILL HAVE TO MONITOR CLOUD TRENDS AS THESE HIGHS
CLOUDS COULD MODULATE WHAT OTHERWISE WOULD BE GOOD RADIATIONAL
CONDITIONS WITH SFC HIGH PRESSURE CENTERED OVER THE AREA. LOWS IN
THE LOWER TO MID 40S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 240 AM SATURDAY...
THE UPPER LEVEL LOW OVER SOUTH CENTRAL CANADA MONDAY WILL SWING
THROUGH THE GREAT LAKES REGION AND INTO NORTHEAST CANADA THROUGH
FRIDAY...WITH THE TROUGH SLOWLY PROGRESSING EAST FROM THE MIDWEST TO
THE ATLANTIC COAST. AT THE SURFACE...HIGH PRESSURE TO START THE
PERIOD WILL BE PUSHED NORTH AND EAST OFFSHORE BY A COLD FRONT MOVING
THROUGH THE CAROLINAS BY MID-WEEK. BEHIND THE FRONT...HIGH PRESSURE
WILL BUILD IN...BRINGING WITH IT A COOLER DRIER POLAR AIRMASS...
WHICH SHOULD LINGER THROUGH THE REMAINDER OF THE PERIOD. MODELS
INDICATE A SURGE OF MOISTURE FROM THE GULF MOVING INTO CENTRAL AND
EASTERN NC TUESDAY...AHEAD OF THE COLD FRONTAL PASSAGE...WHICH COULD
BRING AN INCREASE IN UPPER AND MID LEVEL CLOUD COVER MONDAY EVENING
AND INTO THE OVERNIGHT. WITH THE LATEST MODEL SOLUTIONS...EXPECT
BEST CHANCES FOR RAIN TO BE ACROSS THE EAST TUESDAY. ALTHOUGH THERE
MAY BE SOME LINGERING LOW LEVEL MOISTURE ACROSS THE AREA WEDNESDAY
AND WEDNESDAY NIGHT AND LIGHT RAIN CANNOT BE RULED OUT COMPLETELY...
DRY AIR IS EXPECTED TO BE IN PLACE AT THE MID AND UPPER LEVELS...
WITH NORTH TO NORTHWEST FLOW IN THE LOW LEVELS...WHICH SHOULD HELP
TO INHIBIT ADDITIONAL RAINFALL. AS FOR TEMPERATURES...WILL SEE A
STEADY DECREASE IN HIGHS THROUGH THE PERIOD...BEGINNING IN THE UPPER
60S TO LOW 70S ON MONDAY AND UPPER 50S TO MID 60S BY FRIDAY. EXPECT
OVERNIGHT LOWS TO BE THE COOLEST OF THE SEASON BY MID TO LATE IN THE
PERIOD...STARTING IN THE UPPER 40S TO LOW 50S MONDAY NIGHT...
DECREASING INTO THE MID 30S TO LOW 40S BY WEDNESDAY NIGHT...HOLDING
THROUGH THE END OF THE PERIOD.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 623 AM SATURDAY...
24-HR TAF PERIOD:
A WEAK AREA OF LOW PRESSURE WILL MOVE NORTH-NORTHEASTWARD ALONG A
STALLED FRONT ACROSS COASTAL PORTIONS OF THE CAROLINAS THIS MORNING.
LOW-LEVEL MOISTURE CONVERGENCE ALONG THE LOW PRESSURE WILL RESULT IN
SOME RAIN AND WIDESPREAD SUB-VFR CONDITIONS ACROSS THE AREA THROUGH
LATE MORNING/MIDDAY(15-17Z)....WITH THE HEAVIEST RAINFALL AND MOST
ADVERSE AVIATION IMPACTS OCCURRING IN THE EAST. CIGS WILL RANGE FROM
LIFR AT KFAY/KRWI TO GENERALLY MVFR FOR KGSO/KINT.
AS THE AFOREMENTIONED SURFACE LOW LIFTS OFF TO THE NORTHEAST...
LOW-LEVEL FLOW WILL VEER TO WEST-SOUTHWESTERLY ADVECTING DRIER AIR
INTO THE AREA...WHICH SHOULD ALLOW CEILINGS TO LIFT AND IMPROVE TO
VFR FROM SW TO NE BETWEEN 15-18Z. A DRY COLD FRONT WILL MOVE THROUGH
THE AREA FROM WEST TO EAST BETWEEN 00Z TO 06. SFC WINDS WILL SWING
AROUND TO NWLY BEHIND THE FRONT.
LOOKING AHEAD:
VFR CONDITIONS CONDITIONS SHOULD RETURN SATURDAY EVENING/NIGHT/ WITH
THE PASSAGE OF A DRY COLD FRONT. DRY HIGH PRESSURE WILL RULE SUNDAY
AND INTO EARLY NEXT WEEK...WITH THE NEXT CHANCE FOR PRECIP AND
POSSIBLY SUB-VFR CONDITIONS ON TUESDAY AS A WAVY FRONTAL ZONE
DEVELOPS NEAR THE SE/NC COAST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...CBL/SMITH
SHORT TERM...CBL
LONG TERM...KMC
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
952 AM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT HAS STALLED OVER NORTHERN OHIO AS WE AWAIT AN AREA
OF LOW PRESSURE TO MOVE NORTHWARD ALONG IT. THE LOW SHOULD MOVE
EAST OF THE AREA THIS AFTERNOON AND WILL DRAG THE FRONT INTO
CENTRAL PENNSYLVANIA THIS EVENING. HIGH PRESSURE WILL BRIEFLY
BUILD IN ON SUNDAY BEFORE THE NEXT COLD FRONT MOVES INTO THE AREA
ON MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...ADJUSTED MOST GRIDS THROUGH THE DAY HOWEVER MOST CHANGES
WERE MINOR DUE TO TIMING CHANGES. ALSO ADJUSTED HOURLY AND MAX
TEMPS TOWARD THE HRRR HOWEVER LIMITED HIGHS TO UPPER 50S EAST
WHICH WAS LOWER THAN THE HRRR GUIDANCE. BELIEVE RAIN WILL LIMIT
HIGHS.
ORIGINAL...RAIN IS MOVING INTO WESTERN OHIO WITH SPRINKLES TO A
HUNDREDTH OF AN INCH FROM DAYTON TO FORT WAYNE AS OF 10Z. RADAR
INDICATES THAT IT IS A BIT FURTHER EAST AND MAY SEE LIGHT RAIN AT
FINDLAY AND MARION SHORTLY. SO WITH THESE RADAR TRENDS WE HAVE
NUDGED THE ONSET OF RAIN BY A COUPLE HOURS FROM EARLIER THINKING.
PREVIOUS DISCUSSION...
A COLD FRONT HAS STALLED OVER THE AREA AS WE AWAIT A RIPPLE OF
LOW PRESSURE TO MOVE NORTHWARD ALONG IT. THIS BOUNDARY COMBINED
WITH IMPROVING LIFT ASSOCIATED WITH A 5H JET SHOULD BRING
INCREASING CHANCES OF RAIN. THE RAIN WILL REACH THE SOUTHWESTERN
COUNTY WARNING AREA SHORTLY AFTER SUNRISE AND THEN SPREAD EASTWARD
INTO THE AFTERNOON. THE RAIN MAY NOT REACH THE OH/PA BORDER UNTIL
MID AFTERNOON. AFTER THE RAIN BEGINS IT WILL LIKELY PERSIST FOR 6
TO 8 HOURS. RAINFALL AMOUNTS WILL LIKELY BE AROUND A THIRD OF AN
INCH OR SO.
CLOUD COVER AND THE RAINFALL WILL MAKE IT A COOL DAY WITH HIGHS
GENERALLY WITHIN A COUPLE DEGREES OF 50...SLIGHTLY WARMER ACROSS
EXTREME EASTERN OHIO INTO NW PA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
RAINFALL WILL CONTINUE INTO THE EVENING ACROSS THE EASTERN COUNTY
WARNING AREA BUT SHOULD BECOME FOCUSED DOWNWIND OF LAKE ERIE
AFTER SUNSET. A SOUTHWEST TO WEST WIND SHOULD FOCUS THE SHOWERS
INTO EXTREME NE OHIO INTO NW PA THROUGH THE NIGHT. CLOUD COVER AND
A 10 TO 15 MPH BREEZE SHOULD KEEP FROST FROM DEVELOPING OVERNIGHT
AT MOST LOCATIONS EVEN WITH LOWS DIPPING INTO THE 30S. HOWEVER IF
ENOUGH BREAKS DEVELOP AND WINDS CAN DECOUPLE THERE WILL LIKELY BE
PATCHY FROST...ESPECIALLY ACROSS THE SOUTHWEST HALF OF THE REGION.
WILL MENTION THIS POTENTIAL IN THE HWO AND ALLOW THE NEXT SHIFT TO
EVALUATE THE POTENTIAL FOR A FROST ADVISORY.
DRIER AIR SHOULD ARRIVE ON SUNDAY WITH THE SHOWERS ENDING BY
EARLY AFTERNOON ACROSS NORTHERN ERIE COUNTY. HOWEVER WILL KEEP A
SLIGHT CHANCE GOING INTO THE AFTERNOON IF IT DOES NOT END AS EARLY
AS EXPECTED. THE CLOUD COVER FORECAST WILL BE DIFFICULT BUT
BELIEVE THEY WILL INCREASE DURING THE AFTERNOON UNDER THE BROAD
UPPER LEVEL TROUGH. THE CLOUDS WILL DEFINITELY RETURN SUNDAY NIGHT
AS THE NEXT PIECE OF ENERGY MOVES THROUGH THE UPPER TROUGH. SO
WITH THE EXTRA CLOUD COVER WE SHOULD SEE SLIGHTLY WARMER LOWS FOR
MONDAY MORNING.
RAIN CHANCES WILL ONCE AGAIN INCREASE MONDAY AFTERNOON INTO MONDAY
NIGHT. THE BEST CHANCES WILL BE ALONG A COLD FRONT THAT WILL SWEEP
ACROSS THE REGION FROM WEST TO EAST AFTER DARK. THIS FRONTAL
BOUNDARY WILL HAVE COOLER TEMPERATURES IN ITS WAKE THAN THE LAST
COUPLE. THE LAKE EFFECT SHOWERS THAT DEVELOP IN THE WAKE OF THE
FRONT MAY CHANGE TO SOME SNOW OVER THE INLAND HILLS OF NW PA
TUESDAY NIGHT. MORE ON THIS OVER THE NEXT COUPLE DAYS.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
COOL UPPER TROUGH REMAINS OVER THE GREAT LAKES THROUGH FRIDAY. STILL
UNCERTAINTY IN THE SMALLER DETAILS OF INDIVIDUAL TROUGHS TO CROSS
THE LAKES. WILL HAVE TO KEEP CONTINUAL 30-50 PERCENT PRECIP CHANCES
FOR THE SNOWBELT THROUGH THE END OF THE WEEK. BETWEEN THE LAKE
EFFECT AND THE INDIVIDUAL TROUGHS...CANNOT PICK OUT THE DOWN TIMES
JUST YET. THERE MAY BE OPPORTUNITIES FOR PRECIP OUTSIDE OF THE
SNOWBELT WITH THE PASSAGE OF THE TROUGHS. BOUNDARY LAYER TEMPS WILL
REMAIN JUST WARM ENOUGH FOR PRECIP TO BE RAIN. EXCEPTION WOULD BE
FOR PRECIP FALLING DURING THE EARLY MORNING HOURS. TEMPERATURES WILL
REMAIN BELOW NORMAL WITH HIGHS ONLY IN THE UPPER 40S. NIGHT LOWS
WILL BE IN THE 30S...WITH WIDESPREAD LOWER 30S/FREEZING MORE LIKELY
TOWARD FRIDAY AS HIGH PRESSURE BEGINS TO BUILD OVER THE OHIO VALLEY.
ANY AMOUNT OF CLEARING ANY MORNING MAY RESULT IN TEMPS REACHING
FREEZING INLAND.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
RAIN BEGINNING TO MOVE INTO WESTERN OHIO ALONG WITH MVFR CEILINGS
AND VSBYS. EXPECT THIS AREA OF RAIN AND NON VFR CONDITIONS TO
OVERSPREAD THE REST OF NORTHERN OHIO THIS MORNING AND MAKE IT INTO
NW PA BY EARLY AFTERNOON. ONLY MINOR TIMING ADJUSTMENTS IN THIS
SET OF TAFS. OTHERWISE NON-VFR WEATHER WILL BE CONCENTRATED
BETWEEN NOW AND MID EVENING. EMBEDDED AREAS OF IFR POSSIBLE...BUT
OVERALL IT LOOKS TO BE A PREDOMINATELY MVFR EVENT. SSW FLOW
BECOMES MORE WSW BY THIS AFTERNOON. UNEVENTFUL AND VFR TONIGHT.
OUTLOOK...NON-VFR CIGS MAY RETURN FOR NW PA SUNDAY. OTHERWISE
EXPECT NON VFR FOR MONDAY NIGHT. CONTINUED INTERVALS OF NON VFR
CONDITIONS WILL BE POSSIBLE THROUGH WEDNESDAY...BUT MAINLY FOR FAR
NE OH/NW PA.
&&
.MARINE...
CHOPPY/ROUGH WEEK ON THE LAKE CONTINUES THROUGH THE WEEKEND AND INTO
NEXT WEEK. DIRECTION WILL VARY LITTLE...BETWEEN SSW AND WEST FOR THE
NEXT SEVERAL DAYS. WHILE THERE ARE A FEW LULLS IN THE WIND
SPEEDS...WIND WILL PREDOMINATELY RANGE FROM 10 TO 25 KNOTS.
THEREFORE WILL CONTINUE THE EASTERN TWO THIRDS SMALL CRAFT ADVISORY
AS IS. THE ISLANDS WILL NEED SMALL CRAFT ADVISORIES AT TIMES. ALL OF
THIS IS DUE TO A NUMBER OF FAST MOVING SYSTEMS COMING ACROSS THE
MIDWEST AND GREAT LAKES. WATERSPOUTS MAY ALSO BE POSSIBLE OVER
THE NEXT SEVERAL DAYS...BUT WILL NOT MENTION YET IN THE FORECAST
UNTIL CONDITIONS ARE MORE FAVORABLE AND AREAS OF CONVERGENCE CAN
BE PICKED OUT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT SUNDAY FOR LEZ146>149.
&&
$$
SYNOPSIS...MULLEN
NEAR TERM...TK/MULLEN
SHORT TERM...MULLEN
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1039 AM CDT SAT OCT 19 2013
.UPDATE...
SEE MORNING UPDATE.
&&
.DISCUSSION...
A COLD FRONT HAS CLEARED THE COAST AND SIGNIFICANTLY COOLER
TEMPERATURES AND DRIER AIR ARE FILTERING INTO SOUTHEAST TEXAS.
GRADIENT REMAINS RATHER TIGHT AND SO AM EXPECTING BREEZY CONDS TO
PERSIST. BETWEEN COLD AIR ADVECTION AND MIXING...AM NOT SURE THAT
THEY`LL BE MUCH OF A WARM UP TODAY DESPITE FULL SUNSHINE EXPECTED
THIS AFTN. TWEAKED MAX TEMPS A BIT LOWER OVER THE NORTH. TWEAKED
SKY GRIDS A BIT TO REFLECT RAPID CLEARING OVER THE NORTHERN ZONES.
THE CHANGES ARE VERY MINOR AND THE INTEGRITY OF THE PREVIOUS FCST
IS UNCHANGED AND ON TRACK. 43
&&
.PREV DISCUSSION... /ISSUED 631 AM CDT SAT OCT 19 2013/
UPDATE...
EARLY MORNING UPDATE FOR RAIN MOVING OUT OF THE AREA.
DISCUSSION...
KEEPING UP WITH LATEST RADAR TRENDS HAVE UPDATED RAIN CHANCES FOR
THE DAY AS PRECIP CONTINUES TO MOVE EAST OUT INTO THE GULF. LOOKS
LIKE MOSTLY CLOUDY SKIES TO START THIS MORNING AS COLD FRONT
PUSHES THROUGH THE AREA. COLD FRONT CURRENTLY PUSHING THROUGH
CONROE AND APPROACHING THE HOUSTON AREA. FRONT SHOULD PUSH OFF THE
COAST MID MORNING. UPDATED FORECAST PRODUCTS HAVE BEEN ISSUED.
39
PREV DISCUSSION... /ISSUED 608 AM CDT SAT OCT 19 2013/
DISCUSSION...
SEE AVIATION FOR 12Z TAF DISCUSSION
AVIATION...
SHRA HAVE MOVED OFFSHORE THIS MORNING AND ALL PRECIP MENTIONS WILL
BE REMOVED FROM THE TAFS. NORTHERLY WINDS ALREADY ONGOING AT ALL
SITES AS PREFRONTAL TROUGH HAS PUSHED OFFSHORE WITH THE ACTUAL
COLD FRONT HAVING REACHED CLL AND UTS THIS MORNING. EXPECT AN HOUR
OR TWO WITH GUSTS NEAR 20KTS AS THE FRONTAL BOUNDARY PUSHES
THROUGH THIS MORNING. MAIN CONCERN WILL BE SOUTHERLY EXTENT OF
IFR/MVFR CIGS IMMEDIATELY BEHIND THE FRONT. AS THE SUN COMES UP
THIS MORNING FEEL THAT THIS LAYER WILL BEGIN TO SCATTER OUT SO
HAVE NOT INCLUDED CIGS FOR IAH ALTHOUGH A BRIEF PERIOD OF
BKN010-BKN015 IS POSSIBLE THIS MORNING BEFORE CONDITIONS IMPROVE
TO VFR BY AFTERNOON. SURFACE HIGH PRESSURE WILL SPREAD INTO
SOUTHEAST TEXAS SATURDAY EVENING LEADING TO VARIABLE WINDS ACROSS
THE INLAND AREAS OVERNIGHT INTO SUNDAY. 38
PREV DISCUSSION... /ISSUED 428 AM CDT SAT OCT 19 2013/
DISCUSSION...
COLD FRONT PUSHING SOUTH THROUGH TEXAS AT 09Z (4AM CDT) ABOUT AT
A KLFK/KUTS/K11R LINE OR BASICALLY A BRENHAM TO LUFKIN LINE. LINE
OF SHOWERS AND THUNDERSTORMS OVER HOUSTON EARLIER TONIGHT HAS
WEAKENED AND ACTIVITY HAS INCREASED MORE OFF THE UPPER TX COAST.
UPPER LEVEL SHORT WAVE LOOKS TO BE MOVING OUT OF THE AREA AND
POSSIBLE THAT UPPER LEVEL DIVERGENCE IS WEAKENING AS A RESULT.
BULK OF EARLIER CONVECTION HAS BEEN SUPPORTED BY SOME ISENTROPIC
LIFT AND FRONTOGENESIS IN 925-850MB LAYER PER SPC MESOANALYSES.
PER LATEST RADAR TRENDS...EXPECT SOME LINGERING SHOWERS ALONG THE
COAST BUT LOOKS LIKE MOST OF THE RAINFALL MAY BE DONE BY 12Z WHICH
IS A GOOD 3-6 HRS SOONER THAN MOST 00Z MODEL SOLUTIONS. HOWEVER
THE 00Z TX TECH 3KM WRF AND LATEST 06Z HRRR ARE IN GOOD AGREEMENT
WITH LATEST TRENDS. FORECAST HAS BE TRENDED TOWARDS THESE MODELS
IN THE SHORT TERM BUT MAY HOLD ONTO PRECIP A LITTLE LONGER. COLD
FRONT SHOULD BE OFF THE COAST BETWEEN 12-15Z THIS MORNING WITH
STRONG NORTHERLY WINDS ARE WIDE. UPPER LEVEL TROUGH AXIS WILL ALSO
HAVE PUSHED BY SE TX WITH RIGHT REAR QUADRANT OF JET STREAK STILL
LINGERING OVER THE AREA. HIGH PRESSURE AT THE SURFACE SHOULD
CONTINUE TO BUILD OVER TX TODAY. MAX TEMPS WILL BE A CHALLENGE AS
DO EXPECT SOME COLD ADVECTION TO OCCUR. HOWEVER 850MB TEMPS ONLY
DROP TO ABOUT 12-13C SO COULD STILL SEE TEMPS REACHING UPPER 60S
TO LOW 70S WITH DAYTIME HEATING. CLOUD COVER SHOULD CLEAR OUT SO
MAY NOT GET QUITE AS COOL AS IT COULD WITH BULK OF COLDER AIRMASS
MOVING EAST OF THE AREA OVER MISS RIVER VALLEY.
LOOKS LIKE RETURN FLOW AND WARM ADVECTION WILL ENSUE ONCE AGAIN
SUN NIGHT INTO MONDAY. VERY SIMILAR SET UP TO THE MOST RECENT RAIN
EVENT WITH WEAK ISENTROPIC LIFT AND A SHORT WAVE TROUGH ROTATING
THROUGH THE S PLAINS PROVIDING ENOUGH LARGE SCALE ASCENT FOR
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. THINK ORIENTATION OF
JET STREAK AND SHORT WAVE TROUGH MAY PUSH BULK OF PRECIP EAST OF
SE TX SO HAVE NOT CHANGED POPS MUCH. BEST CHANCES WILL AGAIN BE
ALONG THE COAST BUT WILL KEEP AROUND 50 PERCENT FOR NOW. ANOTHER
COLD FRONT WILL ALSO PUSH INTO SE TX BUT MORE SO MON NIGHT INTO
TUE MORNING. BEST LIFT WILL HAVE SHIFTED EAST BY THIS TIME SO WILL
BE HAVING DECREASING RAIN CHANCES MON NIGHT INTO TUE.
TUE THROUGH THE REST OF THE WEEK SHOULD BE DRY WITH A RATHER
AMPLIFIED UPPER LEVEL PATTERN. BROAD RIDGE SHOULD REMAIN OVER THE
PACIFIC COAST WITH A DEEP LOW AND LONG WAVE TROUGH OVER THE GREAT
LAKES AND MIDWEST. SEVERAL SHORT WAVE TROUGHS MOVING THROUGH THE
FLOW SHOULD KEEP THE TROUGH OVER THE GREAT LAKES THROUGH THE END
OF THE WEEK. WILL GET SFC HIGH PRESSURE BUILDING OVER TX THROUGH
WED WITH ANOTHER RIDGE BUILDING OVER THE MIDWEST THUR INTO FRI.
PATTERN SHOULD KEEP CONDITIONS DRY AND ON THE COOL SIDE. TRIED TO
BLEND THE TEMP FORECAST BETWEEN GFS AND ENSEMBLE MEAN TEMPS FOR
THE LATER HALF OF THE WEEK. THIS WILL MEAN TEMPS WILL BE NEAR OR
EVEN A DEGREE OR TWO BELOW NORMAL FOR THE END OF NEXT WEEK.
39
MARINE...
NORTHERLY WINDS HAVE REACHED THE NEARSHORE BUOY THIS MORNING AS A
PREFRONTAL TROUGH PUSHES OUT AHEAD OF THE COLD FRONT MOVING INTO
SOUTHEAST TEXAS. EXPECT OFFSHORE WINDS TO PICK UP THROUGH THE
MORNING WITH BUILDING SEAS AS THE FRONT MOVES OFFSHORE. ADVISORY
FLAGS IN PLACE ACROSS ALL COASTAL WATERS TODAY AND MAY NEED TO BE
EXTENDED FURTHER STILL...ALTHOUGH WILL ALLOW NEXT SHIFT TO
EVALUATE NEW MODEL DATA AND OBSERVATIONS FROM TODAY BEFORE MAKING
THAT DECISION. EXPECT A QUICK RETURN OF ONSHORE WINDS LATE THIS
WEEKEND AHEAD OF YET ANOTHER FRONTAL PASSAGE EXPECTED LATE MONDAY
INTO TUESDAY. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 66 45 75 58 78 / 10 0 0 10 20
HOUSTON (IAH) 69 47 77 59 78 / 10 0 10 10 40
GALVESTON (GLS) 72 58 76 68 79 / 10 0 10 20 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 6 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
859 AM CDT SAT OCT 19 2013
.DISCUSSION...TWEAKED POPS DOWN TO SLIGHT CHANCE ALONG THE COAST
AND RIVER WITH THE FRONT A FEW HOURS AHEAD OF SCHEDULE. OBS FROM
SOUTH PADRE ISLAND ARE MEETING WIND ADVISORY CRITERIA...AND KBRO
VWP TRENDS SHOW STRONGER 1000-2000FT LEVEL WINDS AS THE DEEPER
COLD ADVECTION MOVES IN. BASED ON OBS AND RAP GUIDANCE EXPECT AT
OR NEAR ADVISORY LEVEL CONDITIONS ON SOUTH PADRE ISLAND AND RIGHT
NEAR THE LAGUNA MADRE THROUGH THE NEXT FEW HOURS SO ISSUED A WIND
ADVISORY UNTIL 2PM. THE FREQUENT GUST TRENDS AND EXPECTATIONS DO
NOT QUITE REQUIRE A GALE WARNING FOR THE LAGUNA/NEARSHORE WATERS
AT THIS TIME. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 749 AM CDT SAT OCT 19 2013/
DISCUSSION...12Z RAOB ANALYSIS AND SURFACE OBSERVATIONS SHOW MUCH
MORE EXTENSIVE 925/850MB COLD ADVECTION THAN WHAT WAS ORIGINALLY
ANTICIPATED WITH THIS COLD FRONT. BUOY OBSERVATIONS ARE PUSHING
GALE FORCE GUSTS IN THE LAST HOUR...AND BASED ON RAP AND OBSERVED
ANALYSIS STRONGER COLD ADVECTION/WIND IS EXPECTED THROUGH THE NEXT
FEW HOURS. WITH THAT UPGRADED THE OFFSHORE WATERS TO A GALE
WARNING THROUGH 4 PM THIS AFTERNOON FOR FREQUENT GALE FORCE GUSTS.
/68-JGG/
MARINE...HAVE UPGRADED THE SMALL CRAFT ADVISORY TO A GALE WARNING
FOR FREQUENT GALE FORCE GUSTS IN THE OFFSHORE ZONES.
PREV DISCUSSION... /ISSUED 651 AM CDT SAT OCT 19 2013/
DISCUSSION...UPDATED FOR LATEST MARINE DISCUSSION BELOW.
MARINE...HAVE MOVED UP THE STARTING TIME OF THE SCA WITH WINDS
BEHIND A LINE OF THUNDERSTORMS EXCEEDING SCA CRITERIA. DO NOT
BELIEVE THERE WILL BE MUCH OF LULL BEFORE HIGH PRESSURE BUILDS
TOWARDS THE COAST IN WAKE OF A COLD FRONT NOW MOVING ACROSS THE
NORTHERN RANCHLANDS. WINDS ACROSS THE LAGUNA MADRE WILL ALSO BE ON
THE INCREASE THIS EARLIER THIS MORNING.
PREV DISCUSSION... /ISSUED 628 AM CDT SAT OCT 19 2013/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...IFR CIGS SPREADING ACROSS THE REGION EARLY THIS
MORNING. EXPECT CIGS TO LOWER AT KHRL AND KBRO BY OR SHORTLY AFTER
SUNRISE. THE LOWER CIGS TO PERSIST THROUGH THE MORNING WITH A SLOW
RISE TO MVFR THIS AFTERNOON. VFR CONDITIONS NOT EXPECTED AT THE
REGIONAL AIRPORTS UNTIL THE EVENING HOURS. HIGH PRESSURE BUILDS
SOUTH INCREASING THE NORTH WIND. GUSTS TO 25 KNOTS ARE POSSIBLE
WITH A STEADY 12-18 KNOT WIND THROUGH THE DAY.
PREV DISCUSSION... /ISSUED 426 AM CDT SAT OCT 19 2013/
SHORT TERM /NOW THROUGH SUNDAY/...
SURFACE OBSERVATIONS INDICATE TWO FRONTS ACROSS SOUTH TEXAS THIS
MORNING. THE LEAD STATIONARY FRONT PARALLELS THE COAST WITH A WEAK
SURFACE LOW OR FRONTAL WAVE EAST OF KENEDY COUNTY. THE SECOND FRONT
EXTENDS FROM NEAR SHREVEPORT TO COTULLA.
MAIN CHALLENGE FOR TODAY IS THE POP FORECAST FOLLOWED BY THE
TEMPERATURES. MOST CONVECTION CURRENTLY HAS BEEN DEVELOPING ALONG
THE COASTAL TROUGH AND NORTHEAST OF SURFACE LOW. MOST OF SOUTH TEXAS
REMAINS UNDER LARGE SCALE ASCENT WITH THE REGION UNDER THE RIGHT
REAR QUADRANT OF 100+ KNOT JET. HOWEVER BEST SURFACE CONVERGENCE IS
NOTED ALONG THE LEAD BOUNDARY AND SURFACE LOW. ANOTHER WEAK
DISTURBANCE IS APPROACHING THE COASTAL AREAS OF TAMAULIPAS WHICH
LOOKS TO PASS TO OUR SOUTH. GUT FEELING FROM CURRENT TRENDS IS FOR
THE MAJORITY OF THE CONVECTION TO REMAIN OFFSHORE WITH SOME ISOLATED
TO POSSIBLE SCATTERED ACTIVITY DEVELOPING OVER THE COASTAL COUNTIES
BEFORE SUNRISE. AS THE SECOND FRONT MOVES INTO THE AREA THE BEST
MOISTURE WILL BE SHOVED EAST WITH LITTLE LEFT TO PRODUCE AS MUCH
RAIN AS WHAT IS CURRENTLY PROJECTED IN THE FORECAST. HAVE ALREADY
LOWERED RAIN CHANCES BUT HAVE REDUCE THE MENTION OF THUNDER EXCEPT
OVER KENEDY COUNTY AND THE GULF WATERS. TIMING OF THE SECOND FRONT
IN LINE WITH THE NAM MODEL WHICH IS ABOUT 3 HOURS SLOWER THEN THE
GFS. THE FRONT TO MOVE THROUGH THE NORTHERN ZONES AROUND OR SHORTLY
AFTER SUNRISE WORKING ITS WAY SOUTH OF BROWNSVILLE BY 10 AM. WE CAN
EXPECT OUR WINDS TO TURN NORTH TO NORTHWEST AHEAD OF THE SECOND
FRONT WITH A MORE NOTICEABLE AIRMASS CHANGE WITH STRONGER WIND AND
COOLING TEMPERATURES AS THE SECOND BOUNDARY PASSES THROUGH THE
REGION. CURRENT OBSERVATIONS INDICATE A NICE COOL AIRMASS OVER
NORTH CENTRAL TEXAS AND SOME OF THAT AIR TO SPREAD SOUTH AS NORTH
WINDS INCREASE TO BREEZY LEVELS. EXPECT HIGH TEMPERATURES TO OCCUR
THIS MORNING WITH A SLOW STEADY FALL THROUGH THE AFTERNOON. ANY RAIN
THAT FALLS BEHIND THE FRONT WILL PROVIDE AN EVAPORATIVE COOLING
AFFECT WHICH WILL ALLOW FOR TEMPERATURES TO FALL MORE QUICKLY ALBEIT
FOR A SHORT WHILE. IN ANY CASE HAVE LOWERED TEMPERATURES A FEW
DEGREES AND IT WILL FEEL A BIT CHILLY WITH A GRAY OVERCAST HOLDING
TOUGH ALL DAY.
TONIGHT...COOL SURFACE HIGH BUILDS MORE OVER EAST TEXAS THEN OVER
OUR REGION WITH NORTH WINDS VEERING NORTHEAST AND DIMINISHING
RAPIDLY. THE COLD AIR ADVECTION DURING THE DAYTIME HOURS WILL BE
WEAKENING. GUIDANCE TEMPERATURES HAVE LOWERED A FEW DEGREES OVER
PREVIOUS RUNS AND WITH EVIDENCE OF TEMPERATURES UPSTREAM WILL TREND
IN THIS DIRECTION EVEN WITH AN OVERCAST CONDITIONS. DO NOT EXPECT
THE CLOUDS TO CLEAR AS 700MB FLOW TURNS SOUTHWEST DEVELOPING WEAK
OVERRUNNING.
SUNDAY...HIGH PRESSURE MOVES WELL EAST AND UPPER FLOW REMAINS
WESTERLY WHICH WILL ALLOW FOR OUR AIRMASS TO BEGIN MODIFYING RATHER
QUICKLY. FRONT STALLS WELL SOUTH AND THE EXPECTED DEVELOPMENT OF A
COASTAL TROUGH MIGHT BE DELAYED BY 6 HOURS. THIS WILL KEEP OUR RAIN
CHANCES LOWER AND LIKELY OUT OVER THE GULF. A SHORTWAVE TROUGH IN
THE WESTERLY FLOW EVENTUALLY WORKS ITS WAY NEAR THE BIG BEND AREA
WITH THE SURFACE INFLECTION DEVELOPING LATER IN THE DAY OR IN THE
EVENING WITH RAIN CHANCES POSSIBLY INCREASE AFTER DARK. WINDS TO
VEER EAST AND TEMPERATURES TO WARM UP WITH SOME BREAKS IN THE
OVERCAST ESPECIALLY ACROSS THE NORTH AND WEST. /59/
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
BROAD UPPER-LEVEL TROUGHINESS WILL CONTINUE TO DOMINATE MUCH OF THE
CENTRAL AND EASTERN UNITED STATES AS WE HEAD INTO THE LONG TERM
PORTION OF THE FORECAST. CLOSER TO HOME...IT LOOKS LIKE SHOWER
POSSIBILITIES WILL CONTINUE AS WE HEAD TOWARD THE START OF THE NEW
WORKWEEK AS A COASTAL TROUGH REMAINS IN PLACE.
LOW-LEVEL THETA-E VALUES WILL LIKELY APPROACH 340K DURING THIS
PERIOD...WITH PRECIPITABLE WATER VALUES RANGING FROM 1.8 INCHES NEAR
THE US-281 CORRIDOR TO A LITTLE MORE THAN 2 INCHES ALONG THE COAST
AND OFFSHORE. THESE PRECIPITABLE WATER VALUES ARE ABOVE THE 75TH
PERCENTILE CLIMATOLOGICALLY. IN OTHER WORDS...PLENTY OF MOISTURE
SHOULD BE SEEN THROUGH THE BOUNDARY LAYER SUNDAY NIGHT AND MONDAY.
COMBINED WITH THE PRESENCE OF THE COASTAL TROUGH...AT LEAST A
SCATTERING OF SHOWERS WILL LIKELY BE SEEN.
I HAVE A CONCERN OR TWO ABOUT THIS SCENARIO THOUGH. MOST OF THE
ISENTROPIC ASCENT AND LOWER CONDENSATION PRESSURE DEFICITS /ALONG
THE 310K THETA SURFACE/ SHIFT OFFSHORE SUNDAY EVENING...WITH
ADDITIONAL MOISTURE MOVING INTO THIS REGION OVERNIGHT. THE UPGLIDE
THEN STRENGTHENS AND STARTS TO MOVE NORTHEAST /AND AWAY FROM OUR
AREA/ MONDAY MORNING. EVIDENCE OF THIS ALSO EXISTS IN THE QG
FIELDS...AS A MID-LEVEL SHORTWAVE TROUGH MOVES NORTHEAST THROUGH THE
REGION.
THIS IMPLIES TO ME TWO THINGS. FIRST...THE BEST TIME TO SEE
PRECIPITATION FOR OUR REGION WILL LIKELY BE LATE SUNDAY NIGHT...
WITH DIMINISHING ODDS MONDAY MORNING. THIS IS A TAD FASTER THAN
WHAT THE CURRENT FORECAST IMPLIES. SECOND...THE ODDS OF SEEING
SHOWERS /MAINLY OVER LAND AREAS/ MAY NOT BE AS GREAT AS THE CURRENT
FORECAST. WITH THIS FORECAST PACKAGE...I HAVE MADE SOME TWEAKS TO
TIMING BASED ON THE LATEST DATA. PRECIPITATION PROBABILITIES HAVE
LARGELY REMAINED UNTOUCHED...AND WILL ALLOW SUBSEQUENT SHIFTS TO
FINE TUNE THE FORECAST USING THE LATEST AVAILABLE DATA.
CONDITIONS SHOULD START TO DRY OUT A BIT MONDAY AFTERNOON AND
EVENING...AS THE SURFACE TROUGH MOVES FARTHER OFFSHORE. A SHORTWAVE
TROUGH IS EXPECTED TO SWING THROUGH THE SOUTHERN PLAINS MONDAY NIGHT
INTO TUESDAY MORNING. THERE MAY BE ENOUGH MOMENTUM ASSOCIATED WITH
THIS FEATURE TO PUSH A WEAK COLD FRONT THROUGH THE AREA TUESDAY
MORNING. SOME LOW CLOUDS MAY REMAIN IN PLACE BEHIND THE FRONT
THANKS TO A BIT OF LINGERING THERMAL TROUGHINESS AT 850MB.
THE UPPER TROUGH AXIS IS FORECAST TO SHIFT EAST WEDNESDAY.
NORTHWEST FLOW ALOFT OVER OUR AREA IN WAKE OF THIS SYSTEM SHOULD
ALLOW THE CENTER OF A SURFACE HIGH TO HEAD INTO THE OZARKS
WEDNESDAY. WEAK SHORTWAVE RIDGING...COMBINED WITH A SURFACE HIGH
NEAR THE ARKLAMISS SHOULD ALLOW QUIET WEATHER CONDITIONS TO BE SEEN
FOR THE REMAINDER OF THE UPCOMING WORKWEEK. /BUTTS/
MARINE...
TODAY THROUGH SUNDAY...
SMALL CRAFT ADVISORIES ARE IN PLACE FOR ALL COASTAL WATERS TODAY AS
NORTH WINDS TO INCREASE BEHIND A COLD FRONT POISED TO MOVE OFFSHORE
AFTER SUNRISE. SEAS TO RESPOND RATHER QUICKLY WITH ROUGH CONDITIONS
BY OR BEFORE NOON. HIGH PRESSURE TO BUILDS NORTH AND EAST OF THE
LOWER TEXAS COAST TONIGHT INTO SUNDAY WITH WINDS AND SEAS LOWERING.
SCA COULD PERSIST FOR THE OFFSHORE WATERS THIS EVENING BUT SHOULD
FALL BELOW CRITERIA BY MIDNIGHT. MORNING SHOWERS AND THUNDERSTORMS
TO FAVOR THE NORTHERN WATERS WITH AREAS OF RAIN WITH EMBEDDED
SHOWERS ACROSS THE SOUTH. MOST OF THE STORMS TO PUSH OFF TO THE
NORTHEAST BEFORE NOON. /59/
SUNDAY NIGHT THROUGH WEDNESDAY...
A TROUGH OF LOW PRESSURE JUST OFFSHORE...COMBINED WITH AMPLE
MOISTURE...SHOULD ALLOW SHOWERS AND A FEW STORMS TO BE SEEN OVER THE
MARINE AREA SUNDAY NIGHT THROUGH MONDAY. E WINDS /GENERALLY 10 KTS
OR LESS/ SHOULD BECOME SE SUNDAY NIGHT...THEN BECOME SW-W MONDAY
AFTERNOON AS THE TROUGH MOVES FARTHER OFFSHORE. A WEAK COLD FRONT
IS FORECAST TO MOVE THROUGH THE MARINE AREA TUESDAY. THIS IS
EXPECTED TO RESULT IN STRENGTHENING N-NE WINDS AND BUILDING SEAS.
SMALL CRAFT ADVISORIES MAY BE NEEDED FOR ALL OR PART OF THE MARINE
AREA DURING THIS TIME. /BUTTS/
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 2 PM CDT THIS AFTERNOON FOR TXZ256-257.
GM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR GMZ130-132-
135.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 1 AM CDT SUNDAY
FOR GMZ170-175.
GALE WARNING UNTIL 4 PM CDT THIS AFTERNOON FOR GMZ170-175.
SMALL CRAFT ADVISORY UNTIL 1 AM CDT SUNDAY FOR GMZ150-155.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/61
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
749 AM CDT SAT OCT 19 2013
.DISCUSSION...12Z RAOB ANALYSIS AND SURFACE OBSERVATIONS SHOW MUCH
MORE EXTENSIVE 925/850MB COLD ADVECTION THAN WHAT WAS ORIGINALLY
ANTICIPATED WITH THIS COLD FRONT. BUOY OBSERVATIONS ARE PUSHING
GALE FORCE GUSTS IN THE LAST HOUR...AND BASED ON RAP AND OBSERVED
ANALYSIS STRONGER COLD ADVECTION/WIND IS EXPECTED THROUGH THE NEXT
FEW HOURS. WITH THAT UPGRADED THE OFFSHORE WATERS TO A GALE
WARNING THROUGH 4 PM THIS AFTERNOON FOR FREQUENT GALE FORCE GUSTS.
/68-JGG/
&&
.MARINE...HAVE UPGRADED THE SMALL CRAFT ADVISORY TO A GALE WARNING
FOR FREQUENT GALE FORCE GUSTS IN THE OFFSHORE ZONES.
&&
.PREV DISCUSSION... /ISSUED 651 AM CDT SAT OCT 19 2013/
DISCUSSION...UPDATED FOR LATEST MARINE DISCUSSION BELOW.
MARINE...HAVE MOVED UP THE STARTING TIME OF THE SCA WITH WINDS
BEHIND A LINE OF THUNDERSTORMS EXCEEDING SCA CRITERIA. DO NOT
BELIEVE THERE WILL BE MUCH OF LULL BEFORE HIGH PRESSURE BUILDS
TOWARDS THE COAST IN WAKE OF A COLD FRONT NOW MOVING ACROSS THE
NORTHERN RANCHLANDS. WINDS ACROSS THE LAGUNA MADRE WILL ALSO BE ON
THE INCREASE THIS EARLIER THIS MORNING.
PREV DISCUSSION... /ISSUED 628 AM CDT SAT OCT 19 2013/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...IFR CIGS SPREADING ACROSS THE REGION EARLY THIS
MORNING. EXPECT CIGS TO LOWER AT KHRL AND KBRO BY OR SHORTLY AFTER
SUNRISE. THE LOWER CIGS TO PERSIST THROUGH THE MORNING WITH A SLOW
RISE TO MVFR THIS AFTERNOON. VFR CONDITIONS NOT EXPECTED AT THE
REGIONAL AIRPORTS UNTIL THE EVENING HOURS. HIGH PRESSURE BUILDS
SOUTH INCREASING THE NORTH WIND. GUSTS TO 25 KNOTS ARE POSSIBLE
WITH A STEADY 12-18 KNOT WIND THROUGH THE DAY.
PREV DISCUSSION... /ISSUED 426 AM CDT SAT OCT 19 2013/
SHORT TERM /NOW THROUGH SUNDAY/...
SURFACE OBSERVATIONS INDICATE TWO FRONTS ACROSS SOUTH TEXAS THIS
MORNING. THE LEAD STATIONARY FRONT PARALLELS THE COAST WITH A WEAK
SURFACE LOW OR FRONTAL WAVE EAST OF KENEDY COUNTY. THE SECOND FRONT
EXTENDS FROM NEAR SHREVEPORT TO COTULLA.
MAIN CHALLENGE FOR TODAY IS THE POP FORECAST FOLLOWED BY THE
TEMPERATURES. MOST CONVECTION CURRENTLY HAS BEEN DEVELOPING ALONG
THE COASTAL TROUGH AND NORTHEAST OF SURFACE LOW. MOST OF SOUTH TEXAS
REMAINS UNDER LARGE SCALE ASCENT WITH THE REGION UNDER THE RIGHT
REAR QUADRANT OF 100+ KNOT JET. HOWEVER BEST SURFACE CONVERGENCE IS
NOTED ALONG THE LEAD BOUNDARY AND SURFACE LOW. ANOTHER WEAK
DISTURBANCE IS APPROACHING THE COASTAL AREAS OF TAMAULIPAS WHICH
LOOKS TO PASS TO OUR SOUTH. GUT FEELING FROM CURRENT TRENDS IS FOR
THE MAJORITY OF THE CONVECTION TO REMAIN OFFSHORE WITH SOME ISOLATED
TO POSSIBLE SCATTERED ACTIVITY DEVELOPING OVER THE COASTAL COUNTIES
BEFORE SUNRISE. AS THE SECOND FRONT MOVES INTO THE AREA THE BEST
MOISTURE WILL BE SHOVED EAST WITH LITTLE LEFT TO PRODUCE AS MUCH
RAIN AS WHAT IS CURRENTLY PROJECTED IN THE FORECAST. HAVE ALREADY
LOWERED RAIN CHANCES BUT HAVE REDUCE THE MENTION OF THUNDER EXCEPT
OVER KENEDY COUNTY AND THE GULF WATERS. TIMING OF THE SECOND FRONT
IN LINE WITH THE NAM MODEL WHICH IS ABOUT 3 HOURS SLOWER THEN THE
GFS. THE FRONT TO MOVE THROUGH THE NORTHERN ZONES AROUND OR SHORTLY
AFTER SUNRISE WORKING ITS WAY SOUTH OF BROWNSVILLE BY 10 AM. WE CAN
EXPECT OUR WINDS TO TURN NORTH TO NORTHWEST AHEAD OF THE SECOND
FRONT WITH A MORE NOTICEABLE AIRMASS CHANGE WITH STRONGER WIND AND
COOLING TEMPERATURES AS THE SECOND BOUNDARY PASSES THROUGH THE
REGION. CURRENT OBSERVATIONS INDICATE A NICE COOL AIRMASS OVER
NORTH CENTRAL TEXAS AND SOME OF THAT AIR TO SPREAD SOUTH AS NORTH
WINDS INCREASE TO BREEZY LEVELS. EXPECT HIGH TEMPERATURES TO OCCUR
THIS MORNING WITH A SLOW STEADY FALL THROUGH THE AFTERNOON. ANY RAIN
THAT FALLS BEHIND THE FRONT WILL PROVIDE AN EVAPORATIVE COOLING
AFFECT WHICH WILL ALLOW FOR TEMPERATURES TO FALL MORE QUICKLY ALBEIT
FOR A SHORT WHILE. IN ANY CASE HAVE LOWERED TEMPERATURES A FEW
DEGREES AND IT WILL FEEL A BIT CHILLY WITH A GRAY OVERCAST HOLDING
TOUGH ALL DAY.
TONIGHT...COOL SURFACE HIGH BUILDS MORE OVER EAST TEXAS THEN OVER
OUR REGION WITH NORTH WINDS VEERING NORTHEAST AND DIMINISHING
RAPIDLY. THE COLD AIR ADVECTION DURING THE DAYTIME HOURS WILL BE
WEAKENING. GUIDANCE TEMPERATURES HAVE LOWERED A FEW DEGREES OVER
PREVIOUS RUNS AND WITH EVIDENCE OF TEMPERATURES UPSTREAM WILL TREND
IN THIS DIRECTION EVEN WITH AN OVERCAST CONDITIONS. DO NOT EXPECT
THE CLOUDS TO CLEAR AS 700MB FLOW TURNS SOUTHWEST DEVELOPING WEAK
OVERRUNNING.
SUNDAY...HIGH PRESSURE MOVES WELL EAST AND UPPER FLOW REMAINS
WESTERLY WHICH WILL ALLOW FOR OUR AIRMASS TO BEGIN MODIFYING RATHER
QUICKLY. FRONT STALLS WELL SOUTH AND THE EXPECTED DEVELOPMENT OF A
COASTAL TROUGH MIGHT BE DELAYED BY 6 HOURS. THIS WILL KEEP OUR RAIN
CHANCES LOWER AND LIKELY OUT OVER THE GULF. A SHORTWAVE TROUGH IN
THE WESTERLY FLOW EVENTUALLY WORKS ITS WAY NEAR THE BIG BEND AREA
WITH THE SURFACE INFLECTION DEVELOPING LATER IN THE DAY OR IN THE
EVENING WITH RAIN CHANCES POSSIBLY INCREASE AFTER DARK. WINDS TO
VEER EAST AND TEMPERATURES TO WARM UP WITH SOME BREAKS IN THE
OVERCAST ESPECIALLY ACROSS THE NORTH AND WEST. /59/
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
BROAD UPPER-LEVEL TROUGHINESS WILL CONTINUE TO DOMINATE MUCH OF THE
CENTRAL AND EASTERN UNITED STATES AS WE HEAD INTO THE LONG TERM
PORTION OF THE FORECAST. CLOSER TO HOME...IT LOOKS LIKE SHOWER
POSSIBILITIES WILL CONTINUE AS WE HEAD TOWARD THE START OF THE NEW
WORKWEEK AS A COASTAL TROUGH REMAINS IN PLACE.
LOW-LEVEL THETA-E VALUES WILL LIKELY APPROACH 340K DURING THIS
PERIOD...WITH PRECIPITABLE WATER VALUES RANGING FROM 1.8 INCHES NEAR
THE US-281 CORRIDOR TO A LITTLE MORE THAN 2 INCHES ALONG THE COAST
AND OFFSHORE. THESE PRECIPITABLE WATER VALUES ARE ABOVE THE 75TH
PERCENTILE CLIMATOLOGICALLY. IN OTHER WORDS...PLENTY OF MOISTURE
SHOULD BE SEEN THROUGH THE BOUNDARY LAYER SUNDAY NIGHT AND MONDAY.
COMBINED WITH THE PRESENCE OF THE COASTAL TROUGH...AT LEAST A
SCATTERING OF SHOWERS WILL LIKELY BE SEEN.
I HAVE A CONCERN OR TWO ABOUT THIS SCENARIO THOUGH. MOST OF THE
ISENTROPIC ASCENT AND LOWER CONDENSATION PRESSURE DEFICITS /ALONG
THE 310K THETA SURFACE/ SHIFT OFFSHORE SUNDAY EVENING...WITH
ADDITIONAL MOISTURE MOVING INTO THIS REGION OVERNIGHT. THE UPGLIDE
THEN STRENGTHENS AND STARTS TO MOVE NORTHEAST /AND AWAY FROM OUR
AREA/ MONDAY MORNING. EVIDENCE OF THIS ALSO EXISTS IN THE QG
FIELDS...AS A MID-LEVEL SHORTWAVE TROUGH MOVES NORTHEAST THROUGH THE
REGION.
THIS IMPLIES TO ME TWO THINGS. FIRST...THE BEST TIME TO SEE
PRECIPITATION FOR OUR REGION WILL LIKELY BE LATE SUNDAY NIGHT...
WITH DIMINISHING ODDS MONDAY MORNING. THIS IS A TAD FASTER THAN
WHAT THE CURRENT FORECAST IMPLIES. SECOND...THE ODDS OF SEEING
SHOWERS /MAINLY OVER LAND AREAS/ MAY NOT BE AS GREAT AS THE CURRENT
FORECAST. WITH THIS FORECAST PACKAGE...I HAVE MADE SOME TWEAKS TO
TIMING BASED ON THE LATEST DATA. PRECIPITATION PROBABILITIES HAVE
LARGELY REMAINED UNTOUCHED...AND WILL ALLOW SUBSEQUENT SHIFTS TO
FINE TUNE THE FORECAST USING THE LATEST AVAILABLE DATA.
CONDITIONS SHOULD START TO DRY OUT A BIT MONDAY AFTERNOON AND
EVENING...AS THE SURFACE TROUGH MOVES FARTHER OFFSHORE. A SHORTWAVE
TROUGH IS EXPECTED TO SWING THROUGH THE SOUTHERN PLAINS MONDAY NIGHT
INTO TUESDAY MORNING. THERE MAY BE ENOUGH MOMENTUM ASSOCIATED WITH
THIS FEATURE TO PUSH A WEAK COLD FRONT THROUGH THE AREA TUESDAY
MORNING. SOME LOW CLOUDS MAY REMAIN IN PLACE BEHIND THE FRONT
THANKS TO A BIT OF LINGERING THERMAL TROUGHINESS AT 850MB.
THE UPPER TROUGH AXIS IS FORECAST TO SHIFT EAST WEDNESDAY.
NORTHWEST FLOW ALOFT OVER OUR AREA IN WAKE OF THIS SYSTEM SHOULD
ALLOW THE CENTER OF A SURFACE HIGH TO HEAD INTO THE OZARKS
WEDNESDAY. WEAK SHORTWAVE RIDGING...COMBINED WITH A SURFACE HIGH
NEAR THE ARKLAMISS SHOULD ALLOW QUIET WEATHER CONDITIONS TO BE SEEN
FOR THE REMAINDER OF THE UPCOMING WORKWEEK. /BUTTS/
MARINE...
TODAY THROUGH SUNDAY...
SMALL CRAFT ADVISORIES ARE IN PLACE FOR ALL COASTAL WATERS TODAY AS
NORTH WINDS TO INCREASE BEHIND A COLD FRONT POISED TO MOVE OFFSHORE
AFTER SUNRISE. SEAS TO RESPOND RATHER QUICKLY WITH ROUGH CONDITIONS
BY OR BEFORE NOON. HIGH PRESSURE TO BUILDS NORTH AND EAST OF THE
LOWER TEXAS COAST TONIGHT INTO SUNDAY WITH WINDS AND SEAS LOWERING.
SCA COULD PERSIST FOR THE OFFSHORE WATERS THIS EVENING BUT SHOULD
FALL BELOW CRITERIA BY MIDNIGHT. MORNING SHOWERS AND THUNDERSTORMS
TO FAVOR THE NORTHERN WATERS WITH AREAS OF RAIN WITH EMBEDDED
SHOWERS ACROSS THE SOUTH. MOST OF THE STORMS TO PUSH OFF TO THE
NORTHEAST BEFORE NOON. /59/
SUNDAY NIGHT THROUGH WEDNESDAY...
A TROUGH OF LOW PRESSURE JUST OFFSHORE...COMBINED WITH AMPLE
MOISTURE...SHOULD ALLOW SHOWERS AND A FEW STORMS TO BE SEEN OVER THE
MARINE AREA SUNDAY NIGHT THROUGH MONDAY. E WINDS /GENERALLY 10 KTS
OR LESS/ SHOULD BECOME SE SUNDAY NIGHT...THEN BECOME SW-W MONDAY
AFTERNOON AS THE TROUGH MOVES FARTHER OFFSHORE. A WEAK COLD FRONT
IS FORECAST TO MOVE THROUGH THE MARINE AREA TUESDAY. THIS IS
EXPECTED TO RESULT IN STRENGTHENING N-NE WINDS AND BUILDING SEAS.
SMALL CRAFT ADVISORIES MAY BE NEEDED FOR ALL OR PART OF THE MARINE
AREA DURING THIS TIME. /BUTTS/
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR GMZ130-132-
135.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 1 AM CDT SUNDAY
FOR GMZ170-175.
GALE WARNING UNTIL 4 PM CDT THIS AFTERNOON FOR GMZ170-175.
SMALL CRAFT ADVISORY UNTIL 1 AM CDT SUNDAY FOR GMZ150-155.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/61
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
631 AM CDT SAT OCT 19 2013
.UPDATE...
EARLY MORNING UPDATE FOR RAIN MOVING OUT OF THE AREA.
&&
.DISCUSSION...
KEEPING UP WITH LATEST RADAR TRENDS HAVE UPDATED RAIN CHANCES FOR
THE DAY AS PRECIP CONTINUES TO MOVE EAST OUT INTO THE GULF. LOOKS
LIKE MOSTLY CLOUDY SKIES TO START THIS MORNING AS COLD FRONT
PUSHES THROUGH THE AREA. COLD FRONT CURRENTLY PUSHING THROUGH
CONROE AND APPROACHING THE HOUSTON AREA. FRONT SHOULD PUSH OFF THE
COAST MID MORNING. UPDATED FORECAST PRODUCTS HAVE BEEN ISSUED.
39
&&
.PREV DISCUSSION... /ISSUED 608 AM CDT SAT OCT 19 2013/
DISCUSSION...
SEE AVIATION FOR 12Z TAF DISCUSSION
AVIATION...
SHRA HAVE MOVED OFFSHORE THIS MORNING AND ALL PRECIP MENTIONS WILL
BE REMOVED FROM THE TAFS. NORTHERLY WINDS ALREADY ONGOING AT ALL
SITES AS PREFRONTAL TROUGH HAS PUSHED OFFSHORE WITH THE ACTUAL
COLD FRONT HAVING REACHED CLL AND UTS THIS MORNING. EXPECT AN HOUR
OR TWO WITH GUSTS NEAR 20KTS AS THE FRONTAL BOUNDARY PUSHES
THROUGH THIS MORNING. MAIN CONCERN WILL BE SOUTHERLY EXTENT OF
IFR/MVFR CIGS IMMEDIATELY BEHIND THE FRONT. AS THE SUN COMES UP
THIS MORNING FEEL THAT THIS LAYER WILL BEGIN TO SCATTER OUT SO
HAVE NOT INCLUDED CIGS FOR IAH ALTHOUGH A BRIEF PERIOD OF
BKN010-BKN015 IS POSSIBLE THIS MORNING BEFORE CONDITIONS IMPROVE
TO VFR BY AFTERNOON. SURFACE HIGH PRESSURE WILL SPREAD INTO
SOUTHEAST TEXAS SATURDAY EVENING LEADING TO VARIABLE WINDS ACROSS
THE INLAND AREAS OVERNIGHT INTO SUNDAY. 38
PREV DISCUSSION... /ISSUED 428 AM CDT SAT OCT 19 2013/
DISCUSSION...
COLD FRONT PUSHING SOUTH THROUGH TEXAS AT 09Z (4AM CDT) ABOUT AT
A KLFK/KUTS/K11R LINE OR BASICALLY A BRENHAM TO LUFKIN LINE. LINE
OF SHOWERS AND THUNDERSTORMS OVER HOUSTON EARLIER TONIGHT HAS
WEAKENED AND ACTIVITY HAS INCREASED MORE OFF THE UPPER TX COAST.
UPPER LEVEL SHORT WAVE LOOKS TO BE MOVING OUT OF THE AREA AND
POSSIBLE THAT UPPER LEVEL DIVERGENCE IS WEAKENING AS A RESULT.
BULK OF EARLIER CONVECTION HAS BEEN SUPPORTED BY SOME ISENTROPIC
LIFT AND FRONTOGENESIS IN 925-850MB LAYER PER SPC MESOANALYSES.
PER LATEST RADAR TRENDS...EXPECT SOME LINGERING SHOWERS ALONG THE
COAST BUT LOOKS LIKE MOST OF THE RAINFALL MAY BE DONE BY 12Z WHICH
IS A GOOD 3-6 HRS SOONER THAN MOST 00Z MODEL SOLUTIONS. HOWEVER
THE 00Z TX TECH 3KM WRF AND LATEST 06Z HRRR ARE IN GOOD AGREEMENT
WITH LATEST TRENDS. FORECAST HAS BE TRENDED TOWARDS THESE MODELS
IN THE SHORT TERM BUT MAY HOLD ONTO PRECIP A LITTLE LONGER. COLD
FRONT SHOULD BE OFF THE COAST BETWEEN 12-15Z THIS MORNING WITH
STRONG NORTHERLY WINDS ARE WIDE. UPPER LEVEL TROUGH AXIS WILL ALSO
HAVE PUSHED BY SE TX WITH RIGHT REAR QUADRANT OF JET STREAK STILL
LINGERING OVER THE AREA. HIGH PRESSURE AT THE SURFACE SHOULD
CONTINUE TO BUILD OVER TX TODAY. MAX TEMPS WILL BE A CHALLENGE AS
DO EXPECT SOME COLD ADVECTION TO OCCUR. HOWEVER 850MB TEMPS ONLY
DROP TO ABOUT 12-13C SO COULD STILL SEE TEMPS REACHING UPPER 60S
TO LOW 70S WITH DAYTIME HEATING. CLOUD COVER SHOULD CLEAR OUT SO
MAY NOT GET QUITE AS COOL AS IT COULD WITH BULK OF COLDER AIRMASS
MOVING EAST OF THE AREA OVER MISS RIVER VALLEY.
LOOKS LIKE RETURN FLOW AND WARM ADVECTION WILL ENSUE ONCE AGAIN
SUN NIGHT INTO MONDAY. VERY SIMILAR SET UP TO THE MOST RECENT RAIN
EVENT WITH WEAK ISENTROPIC LIFT AND A SHORT WAVE TROUGH ROTATING
THROUGH THE S PLAINS PROVIDING ENOUGH LARGE SCALE ASCENT FOR
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. THINK ORIENTATION OF
JET STREAK AND SHORT WAVE TROUGH MAY PUSH BULK OF PRECIP EAST OF
SE TX SO HAVE NOT CHANGED POPS MUCH. BEST CHANCES WILL AGAIN BE
ALONG THE COAST BUT WILL KEEP AROUND 50 PERCENT FOR NOW. ANOTHER
COLD FRONT WILL ALSO PUSH INTO SE TX BUT MORE SO MON NIGHT INTO
TUE MORNING. BEST LIFT WILL HAVE SHIFTED EAST BY THIS TIME SO WILL
BE HAVING DECREASING RAIN CHANCES MON NIGHT INTO TUE.
TUE THROUGH THE REST OF THE WEEK SHOULD BE DRY WITH A RATHER
AMPLIFIED UPPER LEVEL PATTERN. BROAD RIDGE SHOULD REMAIN OVER THE
PACIFIC COAST WITH A DEEP LOW AND LONG WAVE TROUGH OVER THE GREAT
LAKES AND MIDWEST. SEVERAL SHORT WAVE TROUGHS MOVING THROUGH THE
FLOW SHOULD KEEP THE TROUGH OVER THE GREAT LAKES THROUGH THE END
OF THE WEEK. WILL GET SFC HIGH PRESSURE BUILDING OVER TX THROUGH
WED WITH ANOTHER RIDGE BUILDING OVER THE MIDWEST THUR INTO FRI.
PATTERN SHOULD KEEP CONDITIONS DRY AND ON THE COOL SIDE. TRIED TO
BLEND THE TEMP FORECAST BETWEEN GFS AND ENSEMBLE MEAN TEMPS FOR
THE LATER HALF OF THE WEEK. THIS WILL MEAN TEMPS WILL BE NEAR OR
EVEN A DEGREE OR TWO BELOW NORMAL FOR THE END OF NEXT WEEK.
39
MARINE...
NORTHERLY WINDS HAVE REACHED THE NEARSHORE BUOY THIS MORNING AS A
PREFRONTAL TROUGH PUSHES OUT AHEAD OF THE COLD FRONT MOVING INTO
SOUTHEAST TEXAS. EXPECT OFFSHORE WINDS TO PICK UP THROUGH THE
MORNING WITH BUILDING SEAS AS THE FRONT MOVES OFFSHORE. ADVISORY
FLAGS IN PLACE ACROSS ALL COASTAL WATERS TODAY AND MAY NEED TO BE
EXTENDED FURTHER STILL...ALTHOUGH WILL ALLOW NEXT SHIFT TO
EVALUATE NEW MODEL DATA AND OBSERVATIONS FROM TODAY BEFORE MAKING
THAT DECISION. EXPECT A QUICK RETURN OF ONSHORE WINDS LATE THIS
WEEKEND AHEAD OF YET ANOTHER FRONTAL PASSAGE EXPECTED LATE MONDAY
INTO TUESDAY. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 68 45 75 58 78 / 10 10 0 10 20
HOUSTON (IAH) 72 47 77 59 78 / 10 10 0 10 40
GALVESTON (GLS) 74 58 76 68 79 / 10 10 10 20 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 6 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
608 AM CDT SAT OCT 19 2013
.DISCUSSION...
SEE AVIATION FOR 12Z TAF DISCUSSION
&&
.AVIATION...
SHRA HAVE MOVED OFFSHORE THIS MORNING AND ALL PRECIP MENTIONS WILL
BE REMOVED FROM THE TAFS. NORTHERLY WINDS ALREADY ONGOING AT ALL
SITES AS PREFRONTAL TROUGH HAS PUSHED OFFSHORE WITH THE ACTUAL
COLD FRONT HAVING REACHED CLL AND UTS THIS MORNING. EXPECT AN HOUR
OR TWO WITH GUSTS NEAR 20KTS AS THE FRONTAL BOUNDARY PUSHES
THROUGH THIS MORNING. MAIN CONCERN WILL BE SOUTHERLY EXTENT OF
IFR/MVFR CIGS IMMEDIATELY BEHIND THE FRONT. AS THE SUN COMES UP
THIS MORNING FEEL THAT THIS LAYER WILL BEGIN TO SCATTER OUT SO
HAVE NOT INCLUDED CIGS FOR IAH ALTHOUGH A BRIEF PERIOD OF
BKN010-BKN015 IS POSSIBLE THIS MORNING BEFORE CONDITIONS IMPROVE
TO VFR BY AFTERNOON. SURFACE HIGH PRESSURE WILL SPREAD INTO
SOUTHEAST TEXAS SATURDAY EVENING LEADING TO VARIABLE WINDS ACROSS
THE INLAND AREAS OVERNIGHT INTO SUNDAY. 38
&&
.PREV DISCUSSION... /ISSUED 428 AM CDT SAT OCT 19 2013/
DISCUSSION...
COLD FRONT PUSHING SOUTH THROUGH TEXAS AT 09Z (4AM CDT) ABOUT AT
A KLFK/KUTS/K11R LINE OR BASICALLY A BRENHAM TO LUFKIN LINE. LINE
OF SHOWERS AND THUNDERSTORMS OVER HOUSTON EARLIER TONIGHT HAS
WEAKENED AND ACTIVITY HAS INCREASED MORE OFF THE UPPER TX COAST.
UPPER LEVEL SHORT WAVE LOOKS TO BE MOVING OUT OF THE AREA AND
POSSIBLE THAT UPPER LEVEL DIVERGENCE IS WEAKENING AS A RESULT.
BULK OF EARLIER CONVECTION HAS BEEN SUPPORTED BY SOME ISENTROPIC
LIFT AND FRONTOGENESIS IN 925-850MB LAYER PER SPC MESOANALYSES.
PER LATEST RADAR TRENDS...EXPECT SOME LINGERING SHOWERS ALONG THE
COAST BUT LOOKS LIKE MOST OF THE RAINFALL MAY BE DONE BY 12Z WHICH
IS A GOOD 3-6 HRS SOONER THAN MOST 00Z MODEL SOLUTIONS. HOWEVER
THE 00Z TX TECH 3KM WRF AND LATEST 06Z HRRR ARE IN GOOD AGREEMENT
WITH LATEST TRENDS. FORECAST HAS BE TRENDED TOWARDS THESE MODELS
IN THE SHORT TERM BUT MAY HOLD ONTO PRECIP A LITTLE LONGER. COLD
FRONT SHOULD BE OFF THE COAST BETWEEN 12-15Z THIS MORNING WITH
STRONG NORTHERLY WINDS ARE WIDE. UPPER LEVEL TROUGH AXIS WILL ALSO
HAVE PUSHED BY SE TX WITH RIGHT REAR QUADRANT OF JET STREAK STILL
LINGERING OVER THE AREA. HIGH PRESSURE AT THE SURFACE SHOULD
CONTINUE TO BUILD OVER TX TODAY. MAX TEMPS WILL BE A CHALLENGE AS
DO EXPECT SOME COLD ADVECTION TO OCCUR. HOWEVER 850MB TEMPS ONLY
DROP TO ABOUT 12-13C SO COULD STILL SEE TEMPS REACHING UPPER 60S
TO LOW 70S WITH DAYTIME HEATING. CLOUD COVER SHOULD CLEAR OUT SO
MAY NOT GET QUITE AS COOL AS IT COULD WITH BULK OF COLDER AIRMASS
MOVING EAST OF THE AREA OVER MISS RIVER VALLEY.
LOOKS LIKE RETURN FLOW AND WARM ADVECTION WILL ENSUE ONCE AGAIN
SUN NIGHT INTO MONDAY. VERY SIMILAR SET UP TO THE MOST RECENT RAIN
EVENT WITH WEAK ISENTROPIC LIFT AND A SHORT WAVE TROUGH ROTATING
THROUGH THE S PLAINS PROVIDING ENOUGH LARGE SCALE ASCENT FOR
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. THINK ORIENTATION OF
JET STREAK AND SHORT WAVE TROUGH MAY PUSH BULK OF PRECIP EAST OF
SE TX SO HAVE NOT CHANGED POPS MUCH. BEST CHANCES WILL AGAIN BE
ALONG THE COAST BUT WILL KEEP AROUND 50 PERCENT FOR NOW. ANOTHER
COLD FRONT WILL ALSO PUSH INTO SE TX BUT MORE SO MON NIGHT INTO
TUE MORNING. BEST LIFT WILL HAVE SHIFTED EAST BY THIS TIME SO WILL
BE HAVING DECREASING RAIN CHANCES MON NIGHT INTO TUE.
TUE THROUGH THE REST OF THE WEEK SHOULD BE DRY WITH A RATHER
AMPLIFIED UPPER LEVEL PATTERN. BROAD RIDGE SHOULD REMAIN OVER THE
PACIFIC COAST WITH A DEEP LOW AND LONG WAVE TROUGH OVER THE GREAT
LAKES AND MIDWEST. SEVERAL SHORT WAVE TROUGHS MOVING THROUGH THE
FLOW SHOULD KEEP THE TROUGH OVER THE GREAT LAKES THROUGH THE END
OF THE WEEK. WILL GET SFC HIGH PRESSURE BUILDING OVER TX THROUGH
WED WITH ANOTHER RIDGE BUILDING OVER THE MIDWEST THUR INTO FRI.
PATTERN SHOULD KEEP CONDITIONS DRY AND ON THE COOL SIDE. TRIED TO
BLEND THE TEMP FORECAST BETWEEN GFS AND ENSEMBLE MEAN TEMPS FOR
THE LATER HALF OF THE WEEK. THIS WILL MEAN TEMPS WILL BE NEAR OR
EVEN A DEGREE OR TWO BELOW NORMAL FOR THE END OF NEXT WEEK.
39
MARINE...
NORTHERLY WINDS HAVE REACHED THE NEARSHORE BUOY THIS MORNING AS A
PREFRONTAL TROUGH PUSHES OUT AHEAD OF THE COLD FRONT MOVING INTO
SOUTHEAST TEXAS. EXPECT OFFSHORE WINDS TO PICK UP THROUGH THE
MORNING WITH BUILDING SEAS AS THE FRONT MOVES OFFSHORE. ADVISORY
FLAGS IN PLACE ACROSS ALL COASTAL WATERS TODAY AND MAY NEED TO BE
EXTENDED FURTHER STILL...ALTHOUGH WILL ALLOW NEXT SHIFT TO
EVALUATE NEW MODEL DATA AND OBSERVATIONS FROM TODAY BEFORE MAKING
THAT DECISION. EXPECT A QUICK RETURN OF ONSHORE WINDS LATE THIS
WEEKEND AHEAD OF YET ANOTHER FRONTAL PASSAGE EXPECTED LATE MONDAY
INTO TUESDAY. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 68 45 75 58 78 / 10 10 0 10 20
HOUSTON (IAH) 72 47 77 59 78 / 20 10 0 10 40
GALVESTON (GLS) 74 58 76 68 79 / 40 10 10 20 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 6 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...39
AVIATION/MARINE...38
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1012 AM CDT SAT OCT 19 2013
.UPDATE...BROKEN LINE OF SHOWERS WILL EXIT SOUTHEAST WISCONSIN
AROUND MIDDAY AS NEXT ROUND OF SHOWERS MOVES INTO SW WI. SHOWERS
WILL DIMINISH WEST TO EAST DURING THE EVENING AS MID LEVEL TROUGH
AND SURFACE TROUGH PUSH OFF TO THE EAST. 925MB HEIGHTS SUPPORT
HIGHS AROUND 50.
&&
.AVIATION/18Z TAFS/...A FEW SHOWERS OUT THERE RIGHT NOW...BUT BEST
CHANCE FOR SHOWERS WILL BE THIS AFTERNOON AS ANOTHER SHORTWAVE
PUSHES INTO SOUTHERN WISCONSIN. BASED ON LATEST SOUNDINGS AND
UPSTREAM OBS...COULD SEE CIGS BRIEFLY DROP TO MVFR AS THE
SHORTWAVE MOVES THROUGH.
SHOULD BE SOME CLEARING TONIGHT BEHIND THE SHORTWAVE. MORE SHOWERS
ARE THEN POSSIBLE SUNDAY AFTERNOON AND EVENING...THE BEST CHANCE
NORTH OF A LINE FROM DARLINGTON TO MILWAUKEE.
&&
.PREV DISCUSSION... /ISSUED 326 AM CDT SAT OCT 19 2013/
TODAY...FORECAST CONFIDENCE IS HIGH.
FULL LATITUDE TROUGH PHASING JUST ABOUT OVERHEAD CURRENTLY WITH
110 METER 500 MB HEIGHT FALLS CENTERED OVER NORTHERN ILLINOIS
FIRST THING THIS MORNING. DEVELOPING BAROCLINIC LEAF AND SWATH OF
LIGHT PRECIPITATION SHOULD STAY TO THE SOUTH AND EAST.
CIRCULATION WITH DIGGING UPSTREAM TROUGH NOW ALONG MN/ND BORDER
HAS PV1.5 SURFACE POKING BELOW 500 MB AND THIS IS EXPECTED TO MOVE
INTO SOUTHEAST MINNESOTA THIS MORNING AND ACROSS SOUTHERN
WISCONSIN THIS AFTERNOON. EVEN THOUGH HEIGHTS STOP FALLING DURING
THE DAY THE 500 MB COLD CORE OF -30C MOVES ACROSS DURING PEAK
DIURNAL HEATING...WITH MODELS SHOWING STEEP LAPSE RATES IN THE LOW
LEVELS.
LATEST HRRR SHOWS BANDS OF CONVECTIVE SHOWERS MOVING ACROSS DURING
THE LATE MORNING AND AFTERNOON WHICH SEEMS REASONABLE. WOULD NOT
BE SURPRISED IF THERE IS GRAUPEL MIXED IN GIVEN THE LOW FREEZING
LEVEL WITH THE HEAVIER SHOWERS.
TONIGHT...FORECAST CONFIDENCE IS HIGH.
HEIGHTS RISE ABOUT 90 METERS OVERNIGHT AND MODELS SHOW SIGNIFICANT
MID LEVEL DRYING DURING THE NIGHT. PROBABLY WILL NOT COMPLETELY
CLEAR OUT BUT BREAKS IN CLOUDS AND LIGHT WINDS FROM LATE EVENING
INTO THE 3-4 AM PERIOD SHOULD BE SUFFICIENT FOR READINGS TO DROP
TO AROUND FREEZING. MARGINAL NATURE OF EVENT SUGGESTS THAT A FROST
ADVISORY WOULD WORK BEST.
SUNDAY THROUGH MONDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM TO
HIGH.
SHORT TERM MODELS IN DECENT AGREEMENT WITH FEATURES DURING THIS
PERIOD. SURFACE LOW PRESSURE TRACKS FROM SOUTHEASTERN NORTH DAKOTA
TO NORTHWEST WISCONSIN SUNDAY...THEN INTO NORTHERN LAKE SUPERIOR
SUNDAY NIGHT. FOCUSED WARM AIR ADVECTION SPREADS THROUGH THE
REGION AHEAD OF THE LOW ON SUNDAY...WITH A STRONG COLD FRONT
PUSHING EAST THROUGH THE AREA LATE SUNDAY/SUNDAY EVENING.
GOOD LOW LEVEL Q VECTOR CONVERGENCE ALSO SEEN SUNDAY ACROSS THE
AREA. AREA FORECAST SOUNDINGS SHOWING GOOD MID LEVEL MOISTURE
SUNDAY...WITH LOW LEVELS SLOWLY TRYING TO MOISTEN BY LATE IN THE
DAY AND EARLY SUNDAY EVENING. BEST UPWARD VERTICAL MOTION AND DEEP
MOISTURE IS TOWARD CENTRAL WISCONSIN...THOUGH QPF DOES PASS
THROUGH MOST OF THE AREA EXCEPT THE FAR SOUTH.
HAVE LIKELY POPS IN THE FAR NORTHWEST COUNTIES LATER SUNDAY
AFTERNOON...WITH HIGHER END CHANCE POPS SUNDAY INTO SUNDAY EVENING
ACROSS THE NORTHERN HALF OF THE AREA. LOW POPS WERE KEPT IN THE
SOUTH. TEMPERATURE PROFILES WILL BE WARM ENOUGH FOR ALL RAIN.
HIGHS IN THE 50S ARE EXPECTED SUNDAY...BEFORE COLD AIR ADVECTION
WITH BRISK WEST WINDS BEHIND COLD FRONT BRINGS COLDER AIRMASS INTO
THE REGION. LOWS SHOULD DROP INTO THE MID TO UPPER 30S SUNDAY
NIGHT. QUIET WEATHER BUT CHILLY DAY EXPECTED ON MONDAY...WITH
HIGHS ONLY IN THE 40S WITH BRISK WEST WINDS CONTINUING.
ADDED LOW POPS FOR LIGHT RAIN/SNOW SHOWERS IN THE FAR NORTH AND
NORTHEAST COUNTIES MONDAY NIGHT...WITH PASSING 500MB VORTICITY
MAXIMUM WITHIN LARGER CYCLONIC FLOW. GOOD SHOT AT FREEZE WARNING
CRITERIA FOR MONDAY NIGHT...AS LOWS SHOULD DROP INTO THE UPPER 20S
TO LOWER 30S ACROSS THE AREA...WITH DECREASING WEST WINDS. LATER
SHIFTS MAY CONSIDER A FREEZE WATCH FOR THE ENTIRE AREA FOR MONDAY
NIGHT.
TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
ECMWF/GFS SHOWING SOME DIFFERENCES DURING THIS PERIOD. THEY SHOW
A GENERAL NORTHWEST FLOW AT 500MB CONTINUING THROUGH THE
WEEK...WITH SEVERAL VORTICITY MAXIMA SHIFTING THROUGH THE REGION.
THERE ARE TIMING DIFFERENCES WITH THESE FEATURES BETWEEN
ECMWF/GFS.
AT THE SURFACE...WEAK LOW PRESSURE PASSES WELL SOUTHWEST OF THE
AREA TUESDAY ON THE ECMWF/GFS. THEY BOTH THEN BRING HIGH PRESSURE
SOUTHEAST ACROSS THE CENTRAL PLAINS TUESDAY NIGHT. GFS THEN BRINGS
ANOTHER LOW SOUTHEAST THROUGH THE AREA LATER WEDNESDAY AND
WEDNESDAY EVENING...NOT SHOWN ON THE ECMWF.
BOTH MODELS THEN BRING HIGH PRESSURE SOUTHEAST THROUGH THE CENTRAL
PLAINS AGAIN THURSDAY INTO FRIDAY. THEY BOTH DO MAINTAIN THE COLD
AIRMASS OVER THE REGION. FOLLOWED CONSENSUS POPS AND TEMPERATURES
FOR THIS PERIOD. HIGHS SHOULD ONLY REACH THE 40S TUESDAY INTO
FRIDAY. LOWS SHOULD REMAIN IN THE UPPER 20S TO LOWER 30S
INLAND...WITH LOWER TO MID 30S LAKESIDE.
AVIATION/12Z TAFS/...
VFR MID LEVEL CLOUDS ARE EXPECTED MUCH OF THE TIME. UNSTABLE
CONDITIONS DURING THE LATE MORNING AND AFTERNOON WILL RESULT IN
CONVECTIVE SHOWERS WITH LOCALLY GUSTY WINDS...SMALL HAIL...AND
BRIEF MVFR CONDITIONS. THESE CONDITIONS WILL BE MOST LIKELY IN THE
KMSN AREA AND SOMEWHAT LESS LIKELY UNTIL LATE AFTERNOON IN THE
SOUTHEAST TAF SITES.
PARTIAL CLEARING IS EXPECTED TONIGHT WITH VFR CONDITIONS.
MARINE...
LAKE TO 850 MB TEMPERATURE DIFFERENCE INCREASES TO ABOUT 19 THIS
AFTERNOON AS COLD CORE MOVES ACROSS LAKE MICHIGAN. WESTERLY FLOW
REGIME SUGGESTS THAT WATERSPOUT THREAT SHOULD BE CONFINED MAINLY
TO CENTRAL AND EASTERN PORTION OF THE LAKE WHICH WOULD INCLUDE
EXTREME EASTERN PORTIONS OF THE OPEN WATERS.
FAST MOVING LOW ON SUNDAY WILL MOVE ACROSS WISCONSIN AND THEN SLOW
DOWN AS IT MOVES ACROSS LAKE SUPERIOR MONDAY AND MONDAY NIGHT.
THIS WILL BE A WINDY SYSTEM WITH STRONG SOUTH TO SOUTHWEST WINDS
SUNDAY NIGHT TURNING TO THE WEST AND EVENTUALLY NORTHWEST MONDAY
AND MONDAY NIGHT. SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED
OVER THE COASTAL WATERS WITH GUSTY WINDS...WITH GALE FORCE WINDS
AND HIGH WAVES POSSIBLE OVER THE OPEN WATERS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY FROM 1 AM TO 8 AM CDT SUNDAY FOR WIZ046-047-051-
052-056>060-062>072.
LM...NONE.
&&
$$
UPDATE...SM/DDV
TODAY/TONIGHT AND AVIATION/MARINE...CRAVEN
SUNDAY THROUGH FRIDAY...WOOD
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
345 PM EDT SAT OCT 19 2013
.SYNOPSIS...
LOW PRESSURE TRACKING ACROSS SOUTHEASTERN CANADA WILL SEND A WEAK
COLD FRONT THROUGH OUR REGION TONIGHT. HIGH PRESSURE TO OUR
SOUTHWEST WILL THEN OVERSPREAD THE MID ATLANTIC SUNDAY BEFORE
PROGRESSING OFFSHORE MONDAY. ANOTHER COLD FRONT IS THEN FORECAST TO
CROSS THE AREA DURING TUESDAY, FOLLOWED BY POSSIBLE LOW PRESSURE
MOVING ACROSS THE REGION WEDNESDAY INTO WEDNESDAY NIGHT. FOR THE END
OF THE WEEK, STRONG HIGH PRESSURE BUILDS TO OUR WEST ACROSS THE
PLAINS AND MIDWEST STATES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A COMBINATION OF THE GFS AND WRF-NMMB INITIALIZATION LOOKED THE
BEST OFF THE 12Z SOUNDINGS THIS MORNING. ALL THE MODELS ARE VERIFYING
QUITE WELL WITH THEIR 6HR QPF FORECASTS ENDING AT 18Z AND THEY ALL
HAVE SIMILAR RESULTS FOR OUR CWA. THEY ALL HAVE A BIFURCATED LOOK TO
THE PCPN MASS FIELDS AS THE EXIT REGION OF THE 250MB JET AND STRONG
MID LEVEL QVEC CONVERGENCE SEPARATE FROM EACH OTHER. WE ARE LEFT
WITH A LIGHT PCPN EVENT OF SHORT MEASURABLE DURATION MAINLY
CONCENTRATED IN THE EVENING HOURS. THIS IS A LEVEL LOWER TO WHAT
OCCURRED ON THURSDAY NIGHT EXCEPT THIS TIME WE HAVE NO THUNDER IN
OUR FORECAST (INSTABILITY IS EVEN LESS AND EVEN FARTHER REMOVED TO
THE NORTHWEST). MOST PLACES SHOULD MEASURE ONE TENTH OF AN INCH OR
LESS TONIGHT.
THE TIMING OF THE HIEST POPS ARE CLOSE TO THE HRRR OUTPUT WHICH TOO
HAS BEEN DOING RATHER WELL TODAY. AROUND THE HIGHEST POP TIME THIS
EVENING THERE COULD BE SOME SPRINKLES WHICH FOR THE SAKE OF
SIMPLICITY WAS CARRIED AS LOWER CHANCE POPS.
LIKE THURSDAY NIGHT, THE FORECAST SOUNDINGS ARE SHOWING SOME
GUSTINESS AFTER THE FRONT MOVES THROUGH (3Z-6Z MOST PLACES). THE
WRF-NMMB WAS TOO BOLD TWO NIGHTS AGO AND GIVEN HOW MUCH MORE BENIGN
THE GFS FCST SOUNDINGS ARE, WE SPLIT THE DIFFERENCE. WE EXPECT MIN
TEMPERATURES TO REMAIN RELATIVELY UP (AND OCCUR VERY LATE AT NIGHT,
IF NOT AFTER SUNRISE SUNDAY MORNING) BECAUSE OF THE WINDS. WE ARE
CLOSER TO THE HIGHER NAM GUIDANCE, ESPECIALLY EAST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
A DELIGHTFUL OCTOBER WEATHER DAY IS FORECAST FOR SUNDAY WITH AMPLE
SUNSHINE AND TEMPERATURES AT OR SLIGHTLY COOLER THAN NORMAL FOR
MAXES. A SPLIT BETWEEN THE WRF-NMMB AND GFS AS TO WHETHER THE
CONVECTIVE TEMP WILL BE REACHED. WE ARE GETTING CLOSER TO THE
STRATOCU SEASON OF NOVEMBER, SO WE SIDED WITH THE WRF AND KEPT SOME
CLOUD COVERAGE (STILL ON THE SUNNIER SIDE OF THE FENCE) IN THE SKY
GRIDS. THERE WILL BE SOME GUSTINESS FROM THE WEST TO NORTHWEST
WINDS. WE ARE FORECASTING IT TO DECREASE AS THE AFTERNOON CONTINUES
AND HIGH PRESSURE GETS CLOSER. MAX TEMPS WERE BASED ON A 925MB/850MB
ADIABATIC AVERAGE BECAUSE OF THE DOWNSLOPING NORTHWEST FLOW. THIS
WAS AT OR SLIGHTLY ABOVE STAT GUIDANCE WHICH WAS PRETTY PRETTY CLOSE
INDEED.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
A QUIET START TO THE LONG TERM AS SURFACE HIGH PRESSURE WILL BE OVER
THE REGION SUNDAY NIGHT BEFORE EVENTUALLY MOVING EAST AND OFFSHORE
DURING MONDAY. DRY CONDITIONS AND FAIRLY SEASONAL MID-OCTOBER
TEMPERATURES ARE EXPECTED WITH LOWS SUNDAY NIGHT RANGING FROM THE
MID 30S NORTH TO THE MID 40S SOUTH AND DAYTIME HIGHS MONDAY MAINLY
IN THE 60S.
AS SURFACE HIGH PRESSURE EXITS OFFSHORE MONDAY, LOW PRESSURE WILL BE
SLOWLY MOVING ACROSS THE GREAT LAKES AND INTO SOUTHEAST CANADA, WITH
ITS TRAILING COLD FRONT APPROACHING OUR REGION FROM THE OHIO VALLEY.
THIS COLD FRONT IS FORECAST TO TRACK THROUGH OUR AREA DURING
TUESDAY, BUT THE BEST FORCING WILL BE FARTHER TO THE NORTH, AND WITH
LIMITED ATMOSPHERIC MOISTURE ACROSS THE AREA, ANY PRECIPITATION
ASSOCIATED WITH THE FRONTAL PASSAGE LOOKS TO FALL APART AS IT NEARS
OUR REGION. WE HAVE, HOWEVER, KEPT SLIGHT CHANCE POPS FOR ISOLATED
SHOWERS IN PLACE FOR OUR NORTHWEST ZONES, AS THERE MAY BE JUST
ENOUGH LIFT AND MOISTURE FOR A TIME.
THE NEXT FEATURE OF INTEREST WILL BE POSSIBLE LOW PRESSURE MOVING
ACROSS OUR REGION DURING THE WEDNESDAY TO WEDNESDAY NIGHT PERIOD.
THERE IS A LITTLE BIT MORE MODEL CONSISTENCY WITH THIS FEATURE AS
THE ECMWF AND GFS SHOW AN INITIAL SHORTWAVE/CLIPPER-TYPE SYSTEM
MOVING SOUTH OUT OF CENTRAL CANADA EARLY TUESDAY AND REACHING THE
OHIO VALLEY REGION LATER TUESDAY NIGHT, WITH AN OVERALL
STRENGTHENING MID LEVEL TROUGH DEVELOPING. THIS DISTURBANCE IS
PROGGED TO THEN CROSS THE APPALACHIANS AND OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT, WITH THE ECMWF AND GFS THEN INDICATING
STRENGTHENING SURFACE LOW PRESSURE AS IT EMERGES OFF THE MID
ATLANTIC COAST WEDNESDAY NIGHT AND TRACKS NORTHEAST OFF THE NEW
ENGLAND SEABOARD BY EARLY THURSDAY MORNING. MODEL THICKNESSES
DECREASE THROUGH THIS PERIOD, AND DEPENDING ON THE TIMING OF PRECIP,
SOME MIXED PRECIPITATION MAY BE IN STORE FOR THE HIGHER ELEVATIONS
THROUGH THE POCONOS. WE HAVE KEPT LOW POPS IN PLACE WITH THE PASSAGE
OF THIS SYSTEM AND THE IDEA OF A SMALL WINDOW OF MIXED PRECIP FOR
OUR FAR NORTHWEST AREAS. AS CONSISTENCY IN MODEL RUNS IS STILL
WAVERING AT THIS TIME, CONFIDENCE REGARDING THE TIMING AND
DEVELOPMENT OF THIS SYSTEM IS BELOW AVERAGE.
ONCE THIS SYSTEM PASSES EAST AND OFFSHORE, A COOL NORTHWEST FLOW
SETS UP ACROSS THE REGION THROUGH THE END OF THE WEEK AS MID LEVEL
TROUGHING STRENGTHENS AND STRONG SURFACE HIGH PRESSURE BUILDS TO OUR
WEST ACROSS THE PLAINS AND MIDWEST STATES. BELOW NORMAL TEMPERATURES
ARE EXPECTED FOR OUR REGION THROUGH THIS TIMEFRAME, AS MAXIMUM TEMPS
WILL ONLY BE IN THE 50S THURSDAY THROUGH SATURDAY FOR MUCH OF THE
AREA. OVERNIGHT LOWS IN THE 30S WILL BE ON TAP, WITH SOME UPPER 20S
POSSIBLE THROUGH THE HIGHER TERRAIN INTO THE POCONOS AND NORTHWEST
NEW JERSEY.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE 18Z TAFS CARRIED A PERIOD OF MVFR CONDITIONS THIS EVENING AS
SHOWERS MOVE THROUGH.
FOR THE REST OF THIS AFTERNOON VFR CONDITIONS ARE FORECAST WITH
LOWERING CIGS. THE FIRST BAND OF SHOWERS SO FAR HAS REMAINED JUST
SOUTHEAST OF KMIV AND KACY. CIGS THERE MIGHT COME CLOSE TO MVFR
LEVELS. SOUTH WINDS SHOULD AVERAGE AROUND 10 KTS. THERE MIGHT BE
SOME GUSTINESS, BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE.
FOR TONIGHT, WE CONTINUE THE PREVIOUS FORECAST IDEA OF A PERIOD OF
MVFR CONDITIONS MAINLY DUE TO CIGS AS SHOWERS MOVE THROUGH
(APPROXIMATELY 00Z TO 03Z). SOUTH WINDS SHOULD CONTINUE UNTIL THE CFP.
THE CFP IS FORECAST TO MOVE THROUGH 03Z-06Z FROM WEST TO EAST. VFR
CIGS SHOULD BE LIFTING AND WE HAVE ACCEPTED A COMPROMISE APPROACH
TO GUIDANCE SUGGESTIONS AS TO HOW MUCH GUSTINESS FOR A COUPLE OF
HOURS WILL OCCUR FOLLOWING THE CFP.
OVERNIGHT SKIES WILL BECOME CLEAR AND TOO MUCH WIND FOR ANY FOG
TO FORM.
ON SUNDAY VFR CONDITIONS WITH FEW TO SCATTERED CUMULUS CLOUDS
AROUND 5K-6K. SOME GUSTINESS SHOULD RETURN (20 - 25 KTS) AS WEST
TO NORTHWEST WINDS CONTINUE.
OUTLOOK...
SUNDAY NIGHT THROUGH TUESDAY...MAINLY VFR CONDITIONS WITH WINDS
BECOMING SOUTH TO SOUTHWEST.
WEDNESDAY...MOSTLY VFR. POSSIBLE SUB-VFR CONDITIONS IN
ISOLATED/SCATTERED SHOWERS.
THURSDAY...MAINLY VFR WITH GUSTY WEST-NORTHWEST WINDS.
&&
.MARINE...
THE SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR A QUICK SHOT OF GUSTY
WINDS BEHIND THE COLD FRONT TONIGHT INTO SUNDAY MORNING. THE LATEST MODEL
RUN IS DECREASING THE WINDS FASTER, SO AS LONG AS SEAS SUBSIDE
(WHICH WE THINK BECAUSE OF THE OFFSHORE FLOW AND SHORT DURATION), WE
DO NOT ENVISION AN EXTENSION BEYOND THE CURRENT ADVISORY EXPIRATION
TIME. WE LEFT UPPER DELAWARE BAY OUT OF THE ADVISORY FOR NOW AS THE
TIGHTEST GRADIENT THERE OCCURS BEFORE THE LARGER AIR AND WATER
TEMPERATURE DIFFERENTIAL.
OUTLOOK...
HIGH PRESSURE WILL BE IN PLACE ACROSS THE REGION INTO SUNDAY NIGHT,
BEFORE GRADUALLY PROGRESSING OFFSHORE DURING MONDAY. THROUGH THIS
TIMEFRAME, SUB-ADVISORY CONDITIONS ARE ANTICIPATED FOR OUR COASTAL
WATERS AND THROUGH DELAWARE BAY. A COLD FRONT WILL THEN APPROACH AND
CROSS THE REGION DURING TUESDAY, FOLLOWED BY POSSIBLE LOW PRESSURE
WEDNESDAY INTO WEDNESDAY NIGHT. AT THIS TIME, SUB-ADVISORY
CONDITIONS ARE EXPECTED TO CONTINUE; ALTHOUGH, SOME WIND GUSTS TO
AROUND 20 KNOTS ARE POSSIBLE FOR OUR COASTAL WATERS. AN INCREASING
WEST-NORTHWEST FLOW TAKES SHAPE THURSDAY INTO THURSDAY NIGHT, WITH
POSSIBLE SCA CONDITIONS DEVELOPING.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 2 PM EDT SUNDAY
FOR ANZ431-450>455.
&&
$$
SYNOPSIS...KLINE
NEAR TERM...GIGI
SHORT TERM...GIGI
LONG TERM...KLINE
AVIATION...GIGI/KLINE
MARINE...GIGI/KLINE
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
533 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT. MAINLY LIGHT
ISOLATED RAINFALL IS EXPECTED TONIGHT DUE TO THE LIMITED MOISTURE
ASSOCIATED WITH THE FRONT. LOW PRESSURE WILL DEVELOP ON A STALLED
FRONTAL BOUNDARY OFFSHORE BY LATE MONDAY BRINGING ANOTHER CHANCE
FOR RAIN TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
CONVERGENCE ASSOCIATED WITH THE COLD FRONT AND A MID-LEVEL
SHORTWAVE TROUGH WERE HELPING TO SUPPORT SCATTERED SHOWERS.
EXPECT COVERAGE WILL REMAIN SCATTERED BECAUSE OF LIMITED MOISTURE.
THE HRRR KEEPS SHOWERS IN THE EAST PART FOR MUCH OF THE NIGHT.
THE SPC WRF SHOWS ISOLATED SHOWERS EXITING THE EAST PART BY
MIDNIGHT. RADAR TRENDS SUPPORT THE FASTER TIMING. EXPECT FURTHER
DRYING BEHIND THE FRONT OVERNIGHT. THE TEMPERATURE GUIDANCE MAY BE
A LITTLE TOO COOL BECAUSE OF MIXING.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
DRY HIGH PRESSURE WILL BRING MORE SEASONABLE CONDITIONS TO THE
REGION. TEMPERATURES SHOULD BE CLOSE TO NORMAL WITH HIGHS IN THE
LOWER TO MIDDLE 70S. LOWS WILL BE BELOW NORMAL SUNDAY
NIGHT...FALLING INTO THE 40S IN MANY LOCATIONS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AN UPPER-LEVEL LOW OVER THE GREAT LAKES REGION WILL MOVE
NORTHEAST ACROSS EASTERN CANADA DURING THE EXTENDED PERIOD.
SURFACE HIGH PRESSURE WILL MOVE OFF THE EAST COAST MONDAY NIGHT AS
A COLD FRONT APPROACHES FROM THE WEST. ISENTROPIC LIFT/MOISTURE
FLUX WILL INCREASE FROM THE SOUTH DUE TO A STALLED FRONT ACROSS
THE GULF COAST STATES. ALSO FORCING WILL BE PROVIDED BY UPPER
DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A STRENGTHENING JET.
THESE FACTORS WILL BRING A CHANCE OF SHOWERS TO THE FORECAST AREA
MONDAY NIGHT INTO TUESDAY. THE COLD FRONT WILL CROSS OUR AREA
BY LATE TUESDAY.
COOL AND DRY HIGH PRESSURE WILL RETURN WEDNESDAY THROUGH SATURDAY. EXPECT
BELOW NORMAL TEMPERATURES FOR THE LATTER HALF OF THE WEEK.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS. WEAK FRONTAL
BOUNDARY OFF THE COAST...WITH ANOTHER FRONT STILL WELL WEST OF THE
CWA POISED TO PUSH THROUGH TONIGHT. WEAK UPPER IMPULSES WILL
CONTRIBUTE TO SOME LIGHT SHOWER ACTIVITY OR SPRINKLES ACROSS THE
REGION. SOME LIGHT SHOWERS MAY IMPACT CSRA TAF SITES EARLY IN THE
PERIOD...BUT CONDITIONS WILL STILL BE VFR. LATER TONIGHT...THE
MAIN COLD FRONT WILL PASS THROUGH THE REGION...WITH WINDS BECOMING
MORE NORTHWESTERLY. WITH SOME WINDS FORECAST JUST OFF THE
SURFACE...SHOULD HAVE ENOUGH LOW- LEVEL MIXING TO HELP LIMIT ANY
WIDESPREAD FOG FORMATION.
EXTENDED AVIATION OUTLOOK...NO IMPACTS TO AVIATION EXPECTED THROUGH
MONDAY. A CHANCE OF SHOWERS AND ASSOCIATED RESTRICTIONS TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
152 PM EDT SAT OCT 19 2013
.SYNOPSIS...
ISSUED AT 1114 AM EDT SAT OCT 19 2013
THE RAIN WILL BE ENDING FOR MUCH OF THE REGION TODAY AS AN UPPER
LEVEL TROUGH MOVES THROUGH THE AREA. AREAS NEAR LAKE MICHIGAN
COULD STILL SEE SOME LAKE EFFECT SHOWERS THROUGH THE DAY AS
TEMPERATURES REMAIN COOL. HIGH TEMPERATURES TODAY WILL RANGE FROM
THE UPPER 40S IN THE EAST TO THE LOWER 50S IN THE WEST. TONIGHT
THE LAKE EFFECT RAIN SHOWERS WILL BE ENDING. THERE WILL BE A
CHANCE FOR SOME PATCHY FROST LATE TONIGHT/EARLY IN THE MORNING AS
TEMPERATURES DROP DOWN INTO THE UPPER 30S. THEN TOMORROW THERE
WILL BE MORE SUNSHINE AS TEMPERATURES REACH TO AROUND 60 TO THE
LOWER 60S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SAT OCT 19 2013
SEVERAL FORECAST ISSUES TO CONSIDER FOR THIS PACKAGE...ALL REVOLVING
AROUND PRECIP CHANCES.
UPPER LEVEL TROUGH AXIS WAS LOCATED FROM WESTERN MINNESOTA TO
CENTRAL OKLAHOMA WITH STG WAVE QUICKLY ROUNDING THE BASE AND HEADING
NE TOWARDS THE LOWER GREAT LAKES/OHIO VALLEY. UPWARD MOTION WAS
RAPIDLY INCREASING ACROSS THE REGION IN RESPONSE TO INCREASING MID
LEVEL HGT FALLS APPROACHING 120 M/12 HRS ONCE AGAIN PASS ACROSS THE
AREA. LIGHT RAIN/DRIZZLE HAS BEEN SLOWLY EXPANDING ACROSS CENTRAL
ILLINOIS AND WAS RAPIDLY MOVING/EXPANDING NE INTO MUCH OF THE
FORECAST AREA. AS A RESULT HAVE HAD TO BUMP UP POPS DRAMATICALLY IN
MANY AREAS AND ALSO SPEED ARRIVAL/DEPARTURE TIMES. PERIODS OF
RAIN/SHOWERS WILL LIKELY IMPACT MANY SPOTS GENERALLY SE OF KNOX TO
THREE RIVERS LINE WITH HIGH LIKELY/CAT POPS WARRANTED IN THESE
AREAS. HRRR HAS HANDLED OVERALL EVOLUTION WELL OVER THE PAST SEVERAL
RUNS AND QUICKLY EXITS PRECIP BY 17Z. GRIDS NOW SHOWING THESE TRENDS
WITH QPF ON THE ORDER OF A FEW HUNDREDTHS TO MAYBE NEAR A QUARTER
INCH (SE AREAS) WITH A BRIEF LULL INTO MID AFTERNOON BEFORE FOCUS
SHIFTS TO LAKE EFFECT/ENHANCEMENT.
COLDER AIR WILL SETTLE IN QUICKLY TODAY AND TONIGHT WITH 850 MB
TEMPS DROPPING TO AROUND 0C. THIS COMBINED WITH LAKE SFC TEMPS IN
THE MID TEENS CELSIUS (ROUGHLY 17 C) WILL ALLOW FOR STRONG
INSTABILITY OVER THE LAKE AND POINTS INLAND (LK-H85 DELTA T`S AROUND
17 AND LK-H7 DELTA T`S PUSHING 30 C BY TONIGHT). DESPITE
THIS...AVAILABLE MSTR MAY BE SOMEWHAT LIMITED WITH SOUTHWARD EXTENT
INTO NW PORTIONS OF THE AREA. ALSO TRAJECTORY WILL BE MORE 230 TO
260 MUCH OF THE PERIOD WITH DEEPER CLOUD LAYER MSTR RESIDING ACROSS
N BERRIEN/NW CASS INTO REMAINDER OF WESTERN LWR MI. HAVE MAINTAINED
LIKELY POPS IN THE BERRIEN/CASS CO AREAS WITH QUICK DROP IN POPS
FURTHER EAST AND SOUTH. CHANCES WILL LINGER INTO AT LEAST THIS
EVENING AND POSSIBLY OVERNIGHT. HOWEVER...DELTA T`S WILL BEGIN TO
DECREASE SOMEWHAT AND FLOW LESS FAVORABLE FOR THE AREA FOR
ADDITIONAL PRECIP.
AWAY FROM THE LAKE AREAS...POTENTIAL DOES EXIST FOR SOME PATCHY
FROST IN MAINLY OUTLYING AREAS AS LOWS DIP INTO THE MID 30S IN MANY
AREAS. WINDS MAY REMAIN JUST STRONG ENOUGH TO KEEP FORMATION LIMITED
WITH FROST CONFINED TO HIGHER SURFACES OR FAVORED DRAINAGE AREAS.
FOR NOW WILL LEAVE MENTION OUT OF FORECAST AND DEFER TO DAY SHIFT TO
MONITOR CLEARING TRENDS AND ANTICIPATED WINDS.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 457 AM EDT SAT OCT 19 2013
SUCCINCT SHARPENING OF MID CANADA/CONUS TROF UNDERWAY WITH CURRENT
SHORTWAVE DIGGING THROUGH WESTERN GREAT LAKES WITH SUBSTANTIVE
BURGEONING BAROCLINIC LEAF SERN MO INTO CENTRAL ILLINOIS. THIS WAVE
TO RAPIDLY TRANSLATE NEWD TO SOUTHEAST ONTARIO BY LATE THIS EVENING.
BUCKLING POSITIVE HEIGHTS SUNDAY AMID PUTRID MOISTURE PROFILES AND
STRONG LOW LEVEL THERMAL PUSH INTO MID MS VLY POINTS TO FINAL DEATH
KNEEL TO PRIOR TOKEN POP MENTION FOR NWRN CWA SUN. A MORE
TIGHTLY PACKED/VIGORED UPSTREAM ENERGY LOBE NOTED IN WV IMAGERY
64N/105W OR JUST NORTH OF MAN/SASK BORDER POISED FOR CROSS
MERIDIONAL FLOW TO DEEPEN WITH MIDLVL SYSTEM DEEPENING INTO WRN
GREAT LAKES SUNDAY NIGHT INTO MONDAY. CONTD SIMILAR THEME WRT POP
COVERAGE LIMITED TO NWRN/NRN CWA IN STRONG LOW LEVEL WAA...WITH BEST
DYNAMICS SHUNTED W-NW-N OF CWA. AND BEST ALBEIT STILL TEMPERED POPS
FOR MONDAY A LA ANAFRONTAL SCENARIO IN TRAILING LOBE OF HEIGHT
FALLS. IT WILL BE THIS SYSTEMS PASSAGE THAT WILL EFFECTIVELY PUT THE
KIBOSH ON THE NOTABLY STRONG/CYCLICAL CAA/WAA LLVL PATTERN
INTERTWIXT BTWN SYSTEMS OF RECENT PAST...AS FINALLY DEEP COLD AIR
BECOMES ENTRENCHED ACROSS GRT LKS REGN. HEREAFTER...STRONG
CONCURRENCE WITH A PRIORI DISCUSSION/GRIDS AS TO INCREASED ACTIVE
LAKE ENHANCED SHRA POTNL WITH 8H/LK THERMAL DIFFERENTIALS INCREASING
TO AROUND 20C. INCREASED CONFIDENCE OF DEEPER COLD PROFILE SUPPORTS
INTRODUCING POTNL FOR LIQUID/FROZEN MIX BY THURSDAY. SOME MINOR
PROBABILISTIC CONCERN FOR FROZEN PTYPE ON WEDNESDAY...THOUGH ONE
PSBL FLY IN THE OINTMENT MAYBE HINTS OF PLAINS TO MID MS VLY CLIPPER
SYSTEM TO DIVE THRU EASTERN PERIPHERY OF BROADLY ARCHED WRN CONUS
RIDGE. THIS SCENARIO SHOULD FAVOR TEMPORARY BACKING CBL
FLOW/INCREASED IN CLOUD SHEAR. THIS ALONG WITH INITIAL WARM SUB
CLOUD REGION...ESPCLY PROXIMAL TO SRN LK MI SHOULD ALLOW FOR
MELT...LENDS TOWARD OMISSION ATTM. GRADUAL THERMAL MODERATION INTO
NEXT WEEKEND AS A TRANSITIONAL PATTERN AND/OR POSSIBLE TEMPORARY
SPLIT FLOW APPEARS FAVORED. DRYING TREND UNTIL GREATER CONFIDENCE OF
NOTEWORTHY SYSTEM POTNL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 147 PM EDT SAT OCT 19 2013
VFR CONDS XPCD THROUGH THE PD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR LMZ043-046.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...FISHER
LONG TERM...MURPHY
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
500 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT CROSSES THE REGION AND MOVES OFF THE COAST OVERNIGHT.
HIGH PRESSURE SETTLES OVER THE MID ATLANTIC STATES SUNDAY AND
MOVES OFF THE COAST MONDAY. ANOTHER COLD FRONT WILL MOVE THROUGH
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
UPPER LEVEL ANALYSIS HAS A LONG WAVE TROUGH FROM CENTRAL CANADA
SOUTH THROUGH THE MISSISSIPPI VALLEY. SOUTHERN JET STREAM FROM
LOUISIANA TO THE MID ATLANTIC COAST WAS BRINGING MID LEVEL MOISTURE
ACROSS THE CWA. A COLD FRONT EXTENDED FROM LOW PRESSURE OVER THE
NORTHERN GREAT LAKES SOUTH THROUGH EASTERN OHIO AND INTO
MISSISSIPPI. A STATIONARY FRONT EXTENDED ALONG THE CAROLINA COAST
SOUTHWEST INTO THE GULF OF MEXICO.
THE MID LEVEL MOISTURE IN COMBINATION WITH A WEAK SURFACE/LOW LEVEL
TROUGH OVER EASTERN WV WAS RESULTING IN SCATTERED VERY LIGHT SHOWERS
ACROSS MUCH OF THE CWA. MODELS HAVE HANDLED THIS ACTIVITY RATHER
POORLY BUT THE RUC SEEMS TO HAVE THE BEST HANDLE ON IT CURRENTLY.
STARTING THE FORECAST THROUGH 00Z WITH AT LEAST 30 PERCENT POPS.
PCPN AMOUNTS WILL CONTINUE TO BE QUITE LIGHT...GENERALLY A FEW
HUNDREDTHS OF AN INCH AT THE MOST. DRIER AIR WILL GRADUALLY FILTER
IN FROM THE SW WITH A CHC FOR PCPN CONTINUING OVER NORTHERN PORTIONS
TIL 04Z AHEAD OF THE COLD FRONT.
THE COLD FRONT WILL BEGIN TO PASS THROUGH SHORTLY AFTER MIDNIGHT AND
REACH THE COAST BY AROUND 4 AM EDT. THIS WILL BRING SHARP CLEARING
AND SWEEP MUCH OF THE MOISTURE OFF TO THE EAST.
KEPT HOURLY TEMPERATURES ELEVATED THIS EVENING FROM A NORMAL DIURNAL
CURVE THEN LOWERED THEM MORE QUICKLY FOLLOWING THE FRONTAL PASSAGE.
MAINLY USED THE SREF FOR LOW TEMPERATURES SUNDAY MORNING WHICH
VERIFIED WELL FRIDAY MORNING. LOWS ARE FORECAST TO RANGE FROM THE
LWR 40S ACROSS THE PIEDMONT TO MID AND UPR 50S IN THE SE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SFC HIGH PRESSURE PERSISTS THROUGH SUNDAY/SUNDAY NIGHT AND SLIDES
OFFSHORE ON MONDAY. A MOSTLY CLEAR SKY AND COOL TEMPERATURES WILL
PERSIST. WITH HIGH PRESSURE OVER THE AREA SUNDAY...SUBSIDENCE WILL
HOLD TEMPERATURES DOWN FROM THEIR POTENTIAL. HIGHS ARE FORECAST TO
RANGE FROM AROUND 60 IN THE NORTHERN NECK AND THE MD EASTERN SHORE
TO THE MID 60S ALONG THE NC BORDER.
IDEAL RADIATIONAL COOLING WILL THEN BRING THE COOLEST NIGHT SO FAR
THIS SEASON. LOWS MONDAY MORNING RANGE FROM THE UPR 30S WELL INLAND
TO THE MID 40S AT THE COAST.
AS HIGH PRESSURE SLIDES OFF THE COAST...TEMPERATURES WARM A BIT
MONDAY WITH HIGHS IN THE MID TO UPR 60S. WITH THE SOUTHERLY WINDS
AND AN INCREASE IN CLOUDINESS...LOW TEMPERATURES WILL BE MILDER
TUESDAY MORNING...RANGING FROM THE MID 40S INLAND TO THE MID 50S
NEAR THE COAST.
DUE TO LOW PRESSURE DEVELOPMENT ON THE FRONT OFF THE CAROLINA
COAST...THERE IS A SLIGHT TO LOW CHC FOR RAIN OVER SE PORTIONS.
THERE IS UNCERTAINTY AS TO WHETHER THIS WILL EVEN MAKE IT INTO OUR
AREA. FOR NOW HAVE A 30 PERCENT CHANCE FOR SHOWERS NEAR THE
ALBEMARLE SOUND WITH 20 PERCENT POPS INTO SOUTHEAST VIRGINIA. HIGH
TEMPERATURES ACROSS THE AREA ON TUESDAY RANGE FROM 65 TO 70.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
WILL LEAN TOWARD THE 12Z ECMWF MODEL FOR THE EXTENDED PERIOD.
ANOTHER SRN STREAM WEAK LO PRES AREA WILL MOVE OFF THE SE AND MID
ATLC CST LATE TUE INTO WED MORNG...FOLLOWED BY A COLD FRONT
PUSHING OFF THE CST BY WED EVENG. THIS SCENARIO WILL PROVIDE A
SLGT CHC OR SML CHC FOR SHOWERS ACRS THE AREA. THEN...A VERY
DRY/COOL AIRMASS WILL DOMINATE THE REGION WED NGT THRU SAT...AS HI
PRES WILL BLD TWD AND INTO THE AREA FM THE W. MIN TEMPS WILL RANGE
FM THE LWR 40S TO LWR 50S WED MORNG...IN THE UPR 30S TO MID 40S
THU MORNG...AND MAINLY IN THE MID 30S TO LWR 40S FRI AND SAT
MORNGS. MAX TEMPS WILL MAINLY RANGE FM THE UPR 50S TO MID 60S THRU
THE PERIOD.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
MOISTURE FROM DEPARTING LOW PRESSURE OFF THE MID ATLANTIC COAST
AND AHEAD OF APPROACHING COLD FRONT HAS RESULTED IN SPORATIC IFR
CIGS PAST FEW HOURS ALONG WITH AREAS OF LIGHT RAIN. EXPECT THESE
CONDITIONS TO CONTINUE FOR THE NEXT 3-6 HRS BEFORE WINDS TURN MORE
SW AHEAD OF THE FRONT THIS EVENING. THIS SHOULD SCOUR OUT THE ST
LEAVING BKN SC BETWEEN 2-4K FT UNTIL FROPA. EXPECT DECREASING
CLOUDINESS ALONG WITH A WIND SHIFT TO THE N LATE TONITE.
OUTLOOK...VFR CONDITIONS EXPECTED SUN AND MON AS HIGH PRESSURE
BUILDS INTO THE AREA. ANOTHER WEAK SYSTEM PASSES OFF THE NC COAST
TUE AND COULD BRING CIGS DOWN TO 3K FT OR LESS AT KECG/KORF.
&&
.MARINE...
WILL MAINTAIN SCA HEADLINES FOR ALL ZNS EXCEPT SRN TWO CSTL WTRS.
A COLD FRONT WILL PUSH OFF THE CST TNGT...AS HI PRES BLDS IN FM
THE W. SSW WINDS LESS THAN 15 KT WILL SHIFT TO THE NW LATE TNGT
AND INCREASE TO 15 TO 25 KT...WITH GUSTS TO AROUND 30 KT BY SUN
MORNG. THIS NW OR N SURGE WILL LAST THRU SUN MORNG...THEN DIMINISH
RATHER QUICKLY SUN AFTN...AS SFC HI PRES BLDS RIGHT OVR THE AREA.
FAIRLY QUIET SUN NGT INTO TUE...AS FCST AREA WILL BE BETWEEN
ANOTHER SFC LO WELL TO THE S AND ANOTHER LO PRES SYSTEM MOVING
ACRS THE GRT LKS. A STRONG COLD FRONT WILL EVENTUALLY PUSH THRU
LATE WED/WED NGT...BRINGING ANOTHER ROUND OF SCA OR POSSIBLY EVEN
GALE CONDITIONS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO NOON EDT SUNDAY FOR
ANZ632>638-650-652-654.
SMALL CRAFT ADVISORY FROM 1 AM TO NOON EDT SUNDAY FOR ANZ630-
631.
&&
$$
SYNOPSIS...LSA
NEAR TERM...LSA
SHORT TERM...LSA
LONG TERM...TMG
AVIATION...MPR
MARINE...TMG
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
349 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT CROSSES THE REGION AND MOVES OFF THE COAST OVERNIGHT.
HIGH PRESSURE SETTLES OVER THE MID ATLANTIC STATES SUNDAY AND
MOVES OFF THE COAST MONDAY. ANOTHER COLD FRONT WILL MOVE THROUGH
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
UPPER LEVEL ANALYSIS HAS A LONG WAVE TROUGH FROM CENTRAL CANADA
SOUTH THROUGH THE MISSISSIPPI VALLEY. SOUTHERN JET STREAM FROM
LOUISIANA TO THE MID ATLANTIC COAST WAS BRINGING MID LEVEL MOISTURE
ACROSS THE CWA. A COLD FRONT EXTENDED FROM LOW PRESSURE OVER THE
NORTHERN GREAT LAKES SOUTH THROUGH EASTERN OHIO AND INTO
MISSISSIPPI. A STATIONARY FRONT EXTENDED ALONG THE CAROLINA COAST
SOUTHWEST INTO THE GULF OF MEXICO.
THE MID LEVEL MOISTURE IN COMBINATION WITH A WEAK SURFACE/LOW LEVEL
TROUGH OVER EASTERN WV WAS RESULTING IN SCATTERED VERY LIGHT SHOWERS
ACROSS MUCH OF THE CWA. MODELS HAVE HANDLED THIS ACTIVITY RATHER
POORLY BUT THE RUC SEEMS TO HAVE THE BEST HANDLE ON IT CURRENTLY.
STARTING THE FORECAST THROUGH 00Z WITH AT LEAST 30 PERCENT POPS.
PCPN AMOUNTS WILL CONTINUE TO BE QUITE LIGHT...GENERALLY A FEW
HUNDREDTHS OF AN INCH AT THE MOST. DRIER AIR WILL GRADUALLY FILTER
IN FROM THE SW WITH A CHC FOR PCPN CONTINUING OVER NORTHERN PORTIONS
TIL 04Z AHEAD OF THE COLD FRONT.
THE COLD FRONT WILL BEGIN TO PASS THROUGH SHORTLY AFTER MIDNIGHT AND
REACH THE COAST BY AROUND 4 AM EDT. THIS WILL BRING SHARP CLEARING
AND SWEEP MUCH OF THE MOISTURE OFF TO THE EAST.
KEPT HOURLY TEMPERATURES ELEVATED THIS EVENING FROM A NORMAL DIURNAL
CURVE THEN LOWERED THEM MORE QUICKLY FOLLOWING THE FRONTAL PASSAGE.
MAINLY USED THE SREF FOR LOW TEMPERATURES SUNDAY MORNING WHICH
VERIFIED WELL FRIDAY MORNING. LOWS ARE FORECAST TO RANGE FROM THE
LWR 40S ACROSS THE PIEDMONT TO MID AND UPR 50S IN THE SE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SFC HIGH PRESSURE PERSISTS THROUGH SUNDAY/SUNDAY NIGHT AND SLIDES
OFFSHORE ON MONDAY. A MOSTLY CLEAR SKY AND COOL TEMPERATURES WILL
PERSIST. WITH HIGH PRESSURE OVER THE AREA SUNDAY...SUBSIDENCE WILL
HOLD TEMPERATURES DOWN FROM THEIR POTENTIAL. HIGHS ARE FORECAST TO
RANGE FROM AROUND 60 IN THE NORTHERN NECK AND THE MD EASTERN SHORE
TO THE MID 60S ALONG THE NC BORDER.
IDEAL RADIATIONAL COOLING WILL THEN BRING THE COOLEST NIGHT SO FAR
THIS SEASON. LOWS MONDAY MORNING RANGE FROM THE UPR 30S WELL INLAND
TO THE MID 40S AT THE COAST.
AS HIGH PRESSURE SLIDES OFF THE COAST...TEMPERATURES WARM A BIT
MONDAY WITH HIGHS IN THE MID TO UPR 60S. WITH THE SOUTHERLY WINDS
AND AN INCREASE IN CLOUDINESS...LOW TEMPERATURES WILL BE MILDER
TUESDAY MORNING...RANGING FROM THE MID 40S INLAND TO THE MID 50S
NEAR THE COAST.
DUE TO LOW PRESSURE DEVELOPMENT ON THE FRONT OFF THE CAROLINA
COAST...THERE IS A SLIGHT TO LOW CHC FOR RAIN OVER SE PORTIONS.
THERE IS UNCERTAINTY AS TO WHETHER THIS WILL EVEN MAKE IT INTO OUR
AREA. FOR NOW HAVE A 30 PERCENT CHANCE FOR SHOWERS NEAR THE
ALBEMARLE SOUND WITH 20 PERCENT POPS INTO SOUTHEAST VIRGINIA. HIGH
TEMPERATURES ACROSS THE AREA ON TUESDAY RANGE FROM 65 TO 70.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
WILL BE UPDATED SHORTLY
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
MOISTURE FROM DEPARTING LOW PRESSURE OFF THE MID ATLANTIC COAST
AND AHEAD OF APPROACHING COLD FRONT HAS RESULTED IN SPORATIC IFR
CIGS PAST FEW HOURS ALONG WITH AREAS OF LIGHT RAIN. EXPECT THESE
CONDITIONS TO CONTINUE FOR THE NEXT 3-6 HRS BEFORE WINDS TURN MORE
SW AHEAD OF THE FRONT THIS EVENING. THIS SHOULD SCOUR OUT THE ST
LEAVING BKN SC BETWEEN 2-4K FT UNTIL FROPA. EXPECT DECREASING
CLOUDINESS ALONG WITH A WIND SHIFT TO THE N LATE TONITE.
OUTLOOK...VFR CONDITIONS EXPECTED SUN AND MON AS HIGH PRESSURE
BUILDS INTO THE AREA. ANOTHER WEAK SYSTEM PASSES OFF THE NC COAST
TUE AND COULD BRING CIGS DOWN TO 3K FT OR LESS AT KECG/KORF.
&&
.MARINE...
NO CHANGE TO SCA HEADLINES. DISCUSSION WILL FOLLOW SHORTLHY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO NOON EDT SUNDAY FOR
ANZ632>638-650-652-654.
SMALL CRAFT ADVISORY FROM 1 AM TO NOON EDT SUNDAY FOR ANZ630-
631.
&&
$$
SYNOPSIS...LSA
NEAR TERM...LSA
SHORT TERM...LSA
LONG TERM...TMG
AVIATION...MPR
MARINE...TMG
AREA FORECAST DISCUSSION
NWS GAYLORD MI
200 PM EDT SAT OCT 19 2013
.SYNOPSIS...
ISSUED AT 233 AM EDT SAT OCT 19 2013
AN ACTIVE AND CHILLY PATTERN WILL REMAIN ACROSS THE GREAT LAKES
RIGHT THROUGH NEXT WEEK. THE MOST SIGNIFICANT LOW PRESSURE SYSTEM IN
THE NEAR FUTURE WILL MOVE SOUTHEAST FROM CENTRAL CANADA THIS
WEEKEND...REACHING LAKE SUPERIOR BY MONDAY MORNING. THE COLDEST AIR
OF THE FALL SEASON SO FAR WILL ENTER THE REGION BEHIND THE LOW
PRESSURE SYSTEM. TEMPERATURES MAY GET COLD ENOUGH NEXT WEEK TO BRING
THE FIRST SNOWFALL OF THE SEASON...ESPECIALLY TO THE INTERIOR
HIGHLANDS OF NORTHERN LOWER MICHIGAN.
&&
.UPDATE...
ISSUED AT 200 PM EDT SAT OCT 19 2013
SYNOPTIC "WRAP AROUND" PRECIP EXITING INTO LAKE HURON.
BUT...CONVECTIVE SHOWERS HAVE ALREADY DEVELOPED OVER NW LOWER
MICHIGAN AND PARTS OF EASTERN UPPER MICHIGAN...WITHIN LAKE
MICHIGAN AND SUPERIOR "HEAT PLUMES" PUSHING INLAND...AND STEEP
LOW-MID LEVEL LAPSE RATES. HEAVIER SHOWERS ARE PRODUCING SMALL
HAIL...WITNESSED AT THIS OFFICE ABOUT AN HOUR AGO.
REST OF THE AFTERNOON...EXPECT MORE OF THE SAME. CORE OF MID
LEVEL COLD AIR (-30C TO -32C) WILL SLIDE INTO THE REGION LATE THIS
AFTERNOON AND THIS EVENING. DAYTIME AND LAKE HEATING DOWN LOW
SHOULD KEEP SHOWERS GOING THROUGH THE AFTERNOON PARTICULARLY ACROSS
EASTERN UPPER AND NORTHWEST LOWER MICHIGAN WITH FLOW OFF THE
LAKES. SMALL HAIL AND SOME THUNDER ALSO POSSIBLE WITH A FEW
HUNDRED JOULES OF CAPE AND EQUILIBRIUM LEVELS POKING ABOVE -20C.
UPDATE ISSUED AT 1111 AM EDT SAT OCT 19 2013
SHARP SHORT WAVE TROUGH AND FIRST ROUND OF COLDER AIR NOW SWINGING
THROUGH THE WESTERN GREAT LAKES. ASSOCIATED JET CORE AXIS RUNS
NORTHEASTWARD UP THROUGH THE OHIO VALLEY AND ACROSS FAR SE LOWER
MICHIGAN. LEFT EXIT REGION FORCING HELPING TO DEEPEN LOW PRESSURE
OVER NRN LAKE HURON WITH A TRAILING COLD FRONT/SFC TROUGH AXIS
STRETCHING BACK THROUGH NE LOWER MICHIGAN INTO CENTRAL LOWER
MICHIGAN. BATCH OF FAIRLY WIDESPREAD "WRAP AROUND" RAINFALL
MOVING ACROSS NE LOWER MICHIGAN THIS LATE THIS MORNING RIGHT
BEHIND THE FRONT.
FURTHER WEST...WELL DEFINED DRY SLOT/CLEARING LINE POKING UP INTO
THE WESTERN GREAT LAKES AND NOSING INTO EASTERN UPPER/NW LOWER
MICHIGAN.
REST OF TODAY...PER SATELLITE TRENDS...CLEARING LINE WILL WORK ITS
WAY EASTWARD OVER THE NEXT FEW HOURS AS LOW AMPLITUDE LOW-MID
LEVEL RIDGING SLIDES THROUGH THE REGION. THIS WILL BRING VARYING
DEGREES OF SUNSHINE TO THE CWA...AT LEAST FOR A BRIEF PERIOD. BUT
GIVEN THE MAGNITUDE OF COLD AIR AND STEEP LAPSE RATES ALOFT (-2C
AT 850 MB...-30C AT 500 MB LEADING TO 1000-500 MB LAPSE RATES
EXCEEDING 7C/KM) HARD TO IMAGINE WE WONT SEE ANOTHER BATCH OF
SHOWERS DEVELOP THIS AFTERNOON...EITHER UPSTREAM OVER EASTERN
WISCONSIN AND/OR OVER THE LAKE MICHIGAN/NW LOWER MICHIGAN WITHIN
THE LAKE "HEAT PLUME." HAVE SCT-LIKELY SHOWERS IN THE FORECAST
DEVELOPING OVER THE WESTERN PARTS OF THE CWA THIS AFTERNOON INTO
THIS EVENING AS A RESULT.
THUNDER AND SMALL HAIL...NOT OUT OF THE QUESTION GIVEN THE STEEP
LAPSE RATES AND EQUILIBRIUM LEVELS POKING ABOVE -20C.
UPDATE ISSUED AT 651 AM EDT SAT OCT 19 2013
SHOWERS HAVE BEEN SLOW ALL NIGHT TO MOVE INLAND FROM LAKE MI...AND
THAT TREND CONTINUES...THOUGH THERE IS SOMETHING OF A BACK EDGE
PRESSING EASTWARD WEST OF CAD/TVC. HAVE ADJUSTED POP/WX GRIDS THIS
MORNING TO ACCOUNT.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 233 AM EDT SAT OCT 19 2013
FIRST ROUND OF A STEP DOWN PROCESS TO A MUCH COOLER WEATHER REGIME
FIRMLY IN CONTROL OF OUR WEATHER AT THIS EARLY HOUR...COURTESY OF
OVERHEAD TROUGHING IN A REMARKABLY AMPLIFIED NOAM FLOW REGIME.
LATEST RAP HIGH RES ANALYSIS CONFIRMS...WITH H8 TEMPERATURES DIPPING
TO SUB 0C LEVELS ACROSS THE NORTHWEST HALF OF THE AREA. DESPITE
OVERHEAD TROUGHING...MID LEVEL SYNOPTIC DYNAMICS RATHER
NEGLIGIBLE...WITH FIRST WAVE (RESPONSIBLE FOR YESTERDAY`S CONVECTIVE
ACTIVITY) OFF TO OUR NORTHEAST...WITH STRONGER CORE OF MID LEVEL
SUPPORT PINWHEELING IN BASE OF TROUGH AXIS WELL TO OUR SOUTHWEST.
LOW LEVEL FEATURES SOMEWHAT MORE FOCUSED...WITH SURFACE TROUGHING
EXTENDING NORTHEAST TO SOUTHWEST...ESSENTIALLY BISECTING NORTHERN
LOWER MICHIGAN...WITH NOTED H8 TROUGHING JUST OFFSET TO THE WEST OF
THIS SURFACE FRONT. COMBINATION OF ATTENDANT FORCED LOW LEVEL
CONVERGENCE AND FAVORABLE LAKE PROCESSES CONTINUE TO KICK OFF
POCKETS OF SHOWERS...SOME OF WHICH HAVE BEEN LOCALLY HEAVY...
ESPECIALLY ALONG THE LAKE MICHIGAN SHORELINE. SURFACE TEMPERATURES
STILL IN THE 40S AND SURFACE BASED MELTING LAYER AT OR ABOVE 2 KFT
LEADING TO ALL LIQUID SHOWERS. SHORT TERM FORECAST CONCERNS REMAIN
CENTERED ON ADDITIONAL SHOWER POTENTIAL RIGHT THROUGH TONIGHT...AS
WELL AS ADDRESSING THUNDER AND WATERSPOUT CHANCES INTO THIS
EVENING.
REALLY KINDA A LOW CONFIDENCE ENDEAVOR ON FORECASTING SHOWER
EVOLUTION TODAY. NO DOUBT THERMODYNAMIC PROFILES REMAIN VERY
SUPPORTIVE FOR ADDITIONAL LAKE PROCESSES...WITH H8 TEMPERATURES
HOVERING AROUND -2C AND LAKE INDUCED EQUILIBRIUM LEVELS UP AND OVER
20 KFT (LAKE INDUCED CAPE OF AROUND 1.0 J/KG). THAT SAID...
KINEMATICS AND OVERALL SYNOPTIC BACKGROUND SUPPORT NOT NEARLY AS
FAVORABLE FOR WIDESPREAD ORGANIZED LAKE INDUCED SHOWERS. WIND FIELDS
RIGHT UP THROUGH 15 KFT REMAIN RATHER LIGHT AND DISORGANIZED...WITH
LOW LEVEL WINDS STEADILY BACKING THROUGH THE DAY AHEAD OF NEXT
APPROACHING SHORTWAVE TROUGH AND ATTENDANT SURFACE REFLECTION. MAIN
CORE OF ENERGY CURRENTLY TIED TO BASE OF TROUGH AXIS LOOKS TO SLIDE
JUST OFF TO OUR SOUTHEAST...LIKELY NOT HAVING A SIGNIFICANT EFFECT
ON LAKE PROCESS MORPHOLOGY (MAY INCREASE THE ODDS FOR MORE FOCUSED
SHOWERS ACROSS NORTHEAST LOWER THIS MORNING). COMBINE ABOVE WITH
TERRESTRIAL CAPE DEVELOPMENT SIMPLY OVERWHELMING LIMITED CBL
SHEAR...RESULTING IN A DEFINITE CELLULAR COMPONENT TO LAKE SHOWER
ACTIVITY...AND ONE CAN SEE WHY SHOWER COVERAGE REMAINS QUITE
PROBLEMATIC TODAY. SHOWERS WILL NO DOUBT CONTINUE...BUT WILL CONFINE
BETTER COVERAGE CLOSER TO THE LAKE MICHIGAN SHORELINE...WITH BELIEF
OVERALL AREAL COVERAGE WILL DISSIPATE AS THEY MOVE INLAND. SURFACE
BASED CAPE AND H5 TEMPERATURES DIPPING TO -30C WILL DEFINITELY AID
IN AN OVERLAND SHOWER COMPONENT...AND MUCH LIKE YESTERDAY...AN
ISOLATED THUNDERSTORM OR TWO. DEEP MOIST CONVECTION IN SUCH A COLD
ENVIRONMENT WILL DEFINITELY SUPPORT THE THREAT OF BRIEF GRAUPEL
SHOWERS UNDER THE HEAVIER PRECIP CORES. HIGHS TODAY WILL RUN A FEW
DEGREES BELOW NORMAL...WITH AFTERNOON READINGS IN THE 40S AND LOWER
50S.
LAKE PROCESSES LIKELY TO GET A BOOST HEADING INTO THIS EVENING AS
WEAK WAVE AND SURFACE TROUGH/ATTENDANT CORE OF LOW LEVEL CONVERGENCE
CROSS LAKE MICHIGAN. MAY SEE SOME PRETTY HEAVY SHOWERS ALONG THIS
TROUGH AS IT PUSHES ONSHORE...WITH SHOWER COVERAGE ONCE AGAIN
DISSIPATING AS THEY PUSH INLAND. GIVEN MAINTENANCE OF DEEP EQL/S AND
GOOD OVER-WATER CAPE...WILL CONTINUE THUNDER MENTION INTO THIS
EVENING OVER AND NEAR LAKE MICHIGAN. LAKE ENHANCEMENT/SHOWER
COVERAGE BOTH EXPECTED TO DISSIPATE OVERNIGHT AS POST-WAVE
SUBSIDENCE REGIME SPREADS ACROSS AND MOISTURE PROFILES BEGIN TO
THIN.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 233 AM EDT SAT OCT 19 2013
UPPER FLOW IS ANCHORED BY RIDGING ALONG OR JUST OFF THE WEST
COAST...AND BROAD RIDGING IN THE CENTRAL ATLANTIC. IN BETWEEN...
TROFFING REIGNS SUPREME OVER CENTRAL CANADA AND ADJOINING PARTS OF
THE US. THIS PATTERN WILL KEEP NORTHERN MI WX COOL AND UNSETTLED FOR
QUITE SOME TIME. THE REAL FUN ARRIVES TOWARD THE EARLY PART OF NEXT
WEEK...AS THE UPPER LOW NOW OVER NW HUDSON BAY DROPS SOUTHWARD INTO
THE NORTHERN GREAT LAKES. PRECIP TRENDS ARE THE MAIN CONCERN THRU
THE FORECAST.
SUNDAY LOOKS LIKE A /RELATIVE/ LULL IN THE SHOWER ACTIVITY. AS THE
UPPER TROF OVER NORTHERN MI TODAY DEPARTS THE EASTERN LAKES...AND AS
THE NEXT LOW DROPS SOUTH ACROSS MANITOBA...A BIT OF SHORTWAVE
RIDGING GETS PUMPED UP INTO THE CENTRAL/NORTHERN LAKES. SUBTLE
SURFACE RIDGING POKES NORTH TOWARD LAKE HURON AT MIDDAY...THEN MOVES
EAST AS RETURN FLOW RAMPS UP LATE IN THE DAY. THOUGH DEEPER DRYING
IS ARRIVING (850-700MB RH LOWERING BELOW 60 PERCENT)...WITH 850MB
TEMPS -2 TO -3C...WOULD STILL EXPECT AT LEAST SCT SHRA IN THE
MORNING IN W TO WSW FLOW AREAS (MAINLY NW LOWER). MAY CATCH A BIT OF
A PRECIP BREAK MIDDAY TO MID AFTERNOON. AFTER THAT...THE NAM MAY BE
OVERDONE IN DEVELOPING A 45KT 850MB JET PUNCHING UP THE SPINE OF
CENTRAL/SOUTHERN LAKE MI. BUT INCREASING RETURN FLOW WARRANTS A
CHANCE OF SHRA RETURNING VERY LATE IN THE DAY IN SOME WESTERN
SECTIONS. MAX TEMPS NEAR 50 TO THE LOWER 50S.
SUN NIGHT/MONDAY...500MB LOW WILL CONTINUE TO DROP TOWARD INTL FALLS
BY MONDAY MORNING...THEN PIVOT TOWARD CENTRAL LAKE SUPERIOR BY
EVENING. THE ASSOCIATED SURFACE LOW WILL DEEPEN TO AROUND 998MB OVER
CENTRAL SUPERIOR BY MORNING MORNING...THEN FILL A BIT AND ELONGATE
TOWARD THE ENE DURING THE DAY.
ON SUNDAY NIGHT...RAIN WILL SPREAD ENE-WARD FROM NORTHERN/CENTRAL
WI...INITIALLY MAINLY NORTH OF A WARM FRONT THAT LIFTS INTO FAR
NORTHERN LOWER MI BY 06Z. THAT FRONT LIFTS ACROSS EASTERN UPPER MI
OVERNIGHT...BUT THE COLD FRONT IS RIGHT BEHIND...CROSSING MOST OF
THE FORECAST AREA FROM WEST TO EAST. THIS BOUNDARY MAY STILL BE
HANGING AROUND EXTREME EASTERN SECTIONS (OSC-APN-DRUMMOND) AT 12Z.
POPS WILL BE HIGHEST NORTH OF A TVC-APN LINE...WHERE THE LOW LEVEL
JET (850MB WINDS PUSHING 50-55KT AT 03Z) PUNCHES ACROSS THE
ADVANCING WARM FRONT. POPS DIMINISH TO CHANCE IN THE FAR SE.
MONDAY IS A DAY DOMINATED BY MID/UPPER-LEVEL DRY SLOTTING...AS THE
WARM CONVEYOR BELT RACES EAST...AND WRAPAROUND MOISTURE REMAINS BACK
ALONG THE WESTERN AND NORTHERN SHORES OF SUPERIOR. HOWEVER...A
SUBSTANTIAL QUANTITY OF COLD AIR WILL BE PUSHING IN AS THE DAY
PROCEEDS. 850MB TEMPS WILL BE IN THE PROCESS OF SLIDING BACK TO OR
BELOW 0C BY 12Z...READINGS CLOSER TO -6C ARE PROGGED BY SUNSET. THE
INCREASING INSTABILITY SHOULD FIGHT OFF THE DRIER AIR ALOFT...AND
SUPPORT AT LEAST SOME SHRA DOWNWIND OF THE LAKES. WHERE EXACTLY THAT
IT IS STILL CONJECTURE...AS DIFFERENT ORIENTATIONS OF THE SURFACE
LOW TO OUR RESULTS IN DIFFERENT FETCHES (FROM W TO SW). WILL SPLIT
THE DIFFERENCE FOR NOW.
MIN TEMPS NEAR 40F TO THE LOWER 40S. MAX TEMPS ONLY 5F WARMER THAN
THAT WEST...10F EAST...WITH FALLING READINGS IN THE PM. BRISK/WINDY
ON MONDAY.
REST OF THE FORECAST...NO MAJOR CHANGES TO THE EXTENDED.
UNSEASONABLY COOL WX WILL CONTINUE. THOUGH THE UPPER LOW ITSELF WILL
LIFT OUT INTO QUEBEC ON TUESDAY/WEDNESDAY...PLENTY OF TROFFING GETS
LEFT BEHIND. OCCASIONAL REINFORCING SHORTWAVES FROM THE NNW WILL
REINFORCE THE TROFFING...AND THE COLDER AIR AT LOW LEVELS. LAKE
EFFECT SHOWERS WILL CONTINUE DOWNWIND OF THE LAKES...AND MAINTAINED
LIKELY POPS IN THE CLASSIC SNOWBELTS. SPEAKING OF SNOW...PRECIP WILL
GET MIXY TO SNOWY AT TIMES...ESPECIALLY AT NIGHT/MORNING AND
ESPECIALLY IN THE HIGH TERRAIN OF NORTHERN LOWER. THOUGH QUITE
UNCERTAIN WHETHER THIS WILL EVER RISE TO THE LEVEL OF A WINTER WX
HEADLINE...THE MENTION OF THE FIRST SNOW OF THE SEASON PRESENTLY IN
THE HAZ WX OUTLOOK IS REASONABLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 200 PM EDT SAT OCT 19 2013
GENERALLY VFR CONDITIONS ANTICIPATED AT THE TAF SITES THROUGH THE
NEXT 24 HOURS...WITH MAINLY BKN CIGS. SHOWERS WITH SMALL HAIL WILL
IMPACT NORTHWEST LOWER MICHIGAN...PLN/TVC/MBL...THROUGH THE
AFTERNOON AND INTO THE EVENING. BUT SHOWERS WILL SLOWLY DIMINISH
THROUGH THE NIGHT INTO SUNDAY MORNING.
SOME GUSTINESS WILL BE HAD AT THE TERMINAL SITES THROUGH THIS
AFTERNOON...GUSTS UP TO 20 KNOTS. BUT WINDS DIMINISH TONIGHT AND
REMAIN LIGHTER THROUGH SUNDAY MORNING.
&&
.MARINE...
ISSUED AT 233 AM EDT SAT OCT 19 2013
BIG STORY REMAINS ISOLATED WATERSPOUT POTENTIAL TODAY INTO
THIS EVENING. COMBINATION OF UNSEASONABLY CHILLY AIRMASS/WEAK
PARTIALLY LAKE-DRIVEN SURFACE TROUGH/AND DEEP CONVECTION DEFINITELY
SUPPORT THIS POTENTIAL. PRIMARY THREAT IS EXPECTED ACROSS THE WATERS
OF LAKE MICHIGAN AND LAKE HURON...WITH THE THREAT ENDING OVERNIGHT
AS THE SURFACE TROUGH PASSES. OTHERWISE...MARGINALLY GUSTY GENERAL
WEST FLOW TODAY...ALTHOUGH BOTH WINDS AND WAVES LOOK TO REMAIN BELOW
SCA CRITERIA. WINDS BEGIN TO PICK UP OUT OF THE SOUTHEAST
SUNDAY...BECOMING QUITE GUSTY SUNDAY NIGHT. WINDS VEER SOUTHWEST ON
MONDAY BEHIND PASSAGE OF A STRONG COLD FRONT. HEADLINES WILL
EVENTUALLY BE NEED FOR THE WATERS LATER SUNDAY RIGHT THROUGH MONDAY
(AND LIKELY BEYOND). MAY EVEN SEE GALE CONDITIONS ON NORTHERN LAKE
MICHIGAN ON MONDAY AS STRONG LOW PRESSURE PULLS UP ACROSS LAKE
SUPERIOR.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...BA
SYNOPSIS...JZ
SHORT TERM...MB
LONG TERM...JZ
AVIATION...BA
MARINE...MB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
441 PM CDT SAT OCT 19 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 342 PM CDT SAT OCT 19 2013
THE COLD FRONT IS NOW ALMOST COMPLETELY THROUGH MN AND IS
CURRENTLY WORKING ITS WAY ACROSS WEST CENTRAL WI. WE HAD NUMEROUS
REPORTS OF ICE PELLETS TODAY DUE TO THE CONVECTIVE NATURE TO THE
SHOWERS. THIS WAS GRAUPEL GIVEN THE NEAR SURFACE WARM LAYER AND
COLD TEMPS ALOFT. THIS SHOWERY ACTIVITY WILL CONTINUE TO DIMINISH
WITH TIME NOW THAT MN/WI IS POST FRONTAL AND WE ARE LOSING ARE
STEEP LOW LEVEL LAPSE RATES. WE ARE ALREADY SEEING LIGHT BANDED
RAIN IN NORTH CENTRAL ND THIS AFTERNOON IN THE WARM AIR ADVECTION
WING OF THE INCOMING CLIPPER SYSTEM. THIS WILL CONTINUE TO DROP
SOUTHEAST WITH TIME AS THE SYSTEM APPROACHES. KUDOS TO THE NAM FOR
BEING THE TREND SETTER YESTERDAY WITH A MORE SOUTHERLY LOW
TRACK...WHICH IS NOW BEING SHOWN BY THE GEM/ECMWF/GFS. THE 12Z
GUIDANCE TAKES THE LOW ACROSS SOUTHERN MN DURING THE DAY
TOMORROW. THE SOUTHERN SHIFT MEANS AREAS SUCH AS ST. CLOUD...THE
TWIN CITIES...AND EAU CLAIRE WILL END UP WITH A BIT MORE PRECIP
/AT LEAST 0.25"/. THE OVERNIGHT FORECAST MADE LAST NIGHT
RIGHTFULLY BEGAN PULLING THE HIGHER POPS FARTHER SOUTH. THERE IS
STILL A REALLY STRONG FRONOTGENESIS SIGNAL ACROSS CENTRAL MN
BETWEEN 12-18Z TOMORROW. THIS SUGGESTS A QUICK CHANGE OVER TO SNOW
IS LOOKING MORE LIKELY. NOT TO MENTION THAT THE FORECAST SOUNDINGS
SHOW QUICK COLUMN COOLING AT THE ONSET OF PRECIP GIVEN THE LOWER
BL WET BULB TEMPERATURE. 2 TO 4 INCHES SEEMS ENTIRELY POSSIBLE ON
GRASSY AND ELEVATED SURFACES IN THE NORTHERN PORTIONS OF THE
FORECAST AREA. NEAR AND SOUTH OF THE I-94 CORRIDOR WILL STRUGGLE
TO GET A FEW TENTHS GIVEN THE WARMTH OF THE NEAR SURFACE WARM
LAYER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 342 PM CDT SAT OCT 19 2013
BY LATE SUNDAY EVENING...THE DRY SLOT OF THE CLIPPER WILL BE
SPREADING ACROSS THE CWA WITH GOOD Q-VECTOR DIVERGENCE. THIS WILL
LIKELY YIELD A DRY NIGHT FOR MOST LOCATIONS SUNDAY NIGHT AND
MONDAY MORNING. THE TROUGH HANGS BACK ACROSS NORTHERN MN ON
MONDAY...SO LIGHT SHOWERS SEEM REASONABLE /AGAIN MAINLY NORTH OF
I-94/. LIGHT SNOW WILL BE THE DOMINATE PRECIP TYPE ON MONDAY. THE
PATTERN REMAINS COOL AND MOSTLY DRY THROUGH THE EXTENDED AFTER THE
WEEKEND...WITH THE LONGWAVE TROUGH BEGINNING TO SHIFT SLIGHTLY EAST
NEAR THE END OF NEXT WEEK OFF THE ECMWF. THE GFS KEEP THE TROUGH
MORE FIRMLY IN PLACE THROUGH THE ENTIRE 240-HR FORECAST...WITH
CONTINUED WELL BELOW NORMAL TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 102 PM CDT SAT OCT 19 2013
MVFR CIGS MAY HANG IN THERE THIS AFTERNOON A LITTLE LONGER THAN
PREVIOUSLY THOUGHT. UPPER TROUGH STILL OVER EASTERN MN AND WI AT
MIDDAY. LATEST RAP SHOWS CYCLONIC LOW LEVEL FLOW DOES NOT REALLY
SHIFT EASTWARD ACROSS WESTERN WISCONSIN UNTIL EARLY EVENING. LAMP
HANGS ON A LITTLE LONGER AS WELL...AND SATELLITE TRENDS CERTAINLY
BEAR THIS OUT EVEN IN WEST CENTRAL MN. BUT CELLULAR CU WILL
DISSIPATE AROUND SUNSET. NEXT SYSTEM IN NW FLOW IS QUICK ON ITS
HEELS... WITH MVFR CIGS/VSBYS MOVING INTO WEST CENTRAL MN LATE
TONIGHT. PREVIOUS FORECAST TIMING LOOKS ABOUT RIGHT...THOUGH WILL
ADD SOME DETAIL TO THE ONSET OF PRECIP IN TERMS OF DEVELOPMENT OF MVFR.
KAXN AND KSTC WILL LIKELY SEE IFR CIGS SUNDAY MORNING...CLOSER TO
THE HEAVIER PRECIP...WHERE IT MAY WELL LEAN MORE TO SNOW THAN
RAIN.
KMSP...
MVFR CIGS AROUND 2500 FT AGL WILL REMAIN AROUND KMSP AT LEAST
THROUGH MID AFTERNOON AMID LOW LEVEL CYCLONIC FLOW. WILL NOT BE
SURPRISED IF 2500 FOOT CEILINGS PERSIST UNTIL 23Z OR SO. QUIET
NIGHT WITH BRIEF RIDGE MOVING ACROSS AS LIGHT WINDS SHIFT FROM NW
TO S. NEXT SYSTEM MOVES IN QUICKLY AFTER 12Z...WITH GOOD POTENTIAL
FOR MVFR CEILING/VISIBILITY AROUND 15Z. MIGHT BE SOME WET SNOW
MOVED IN DURING ONSET OF PRECIP TOMORROW...BUT SHOULD GENERALLY BE
RAIN. IT MIGHT END SHORTLY BEFORE 21/00Z BUT NOT SURE YET SO DID
LET IT PERSIST AFTER 15Z AND THROUGH THE BALANCE OF THE FORECAST.
/OUTLOOK FOR KMSP/
MON...VFR WITH -RA/SN POSSIBLE. WINDS NW AT 10G15KT.
TUE...VFR WITH MVFR CIGS POSSIBLE EARLY. WINDS NW AT 10KTS.
WED...VFR WITH MVFR AND -RA/SN POSSIBLE. WINDS SW AT 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF
LONG TERM...CLF
AVIATION...TDK
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
102 PM CDT SAT OCT 19 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT SAT OCT 19 2013
A WEAK SURFACE TROUGH WAS LOCATED ACROSS WESTERN MINNESOTA THIS
MORNING...WITH AN EQUALLY WEAK RIDGE OVER THE DAKOTAS. FARTHER
UPSTREAM WINDS WERE OUT OF THE SOUTHEAST IN RESPONSE TO THE
DEVELOPING SYSTEM THAT WILL BRING MEASURABLE SNOW ACROSS THE REGION
LATE TONIGHT INTO SUNDAY MORNING. EARLY MORNING WATER VAPOR
IDENTIFIED THIS SYSTEM OVER NORTHERN BRITISH COLUMBIA. OVER THE NEXT
24 HOURS THIS SHORTWAVE WILL DIVE SOUTHEAST AND EMERGE ACROSS THE
HIGH PLAINS. A CLASSIC LOW LEVEL THERMAL SIGNATURE AT H850 WILL
DEVELOP AHEAD OF THIS WAVE AS IDENTIFIED BY MARTIN ET AL 2007. BROAD
ISENTROPIC ASCENT WILL EVENTUALLY BECOME A FOCUSED REGION OF
VERTICAL MOTION DRIVEN BY H850-700 FGEN. THIS MESOSCALE FORCING WILL
DEVELOP A NARROW BAND OF ACCUMULATING SNOW EXPECTED TO ENTER WESTERN
MINNESOTA LATE SATURDAY NIGHT. THE NAM 19.00 FORECAST SOUNDING
AT SAINT CLOUD SHOWS A VEERING WIND PROFILE...WITH MAX OMEGA IN THE
H800-700 LAYER. THE COBB OUTPUT KEEPS THE MAJORITY OF THE PRECIP AS
LIQUID...AND THEREFORE DOESNT PRODUCE VIRTUALLY ANY SNOW.
HOWEVER...JUST UP THE ROAD AT BRAINERD THE COBB OUTPUT HAS 1.9
INCHES...AND BUFKIT OUTPUT HAS UP TO 4 INCHES. SREF PLUMES SHOW 2
INCHES AT AXN...BUT THESE VALUES ARE LIKELY INFLATED BY A FACTOR OF
TWO DUE TO A FEW OF THE MORE ROBUST RUNS.
MORE OFTEN THAN NOT THE LARGE SCALE MODELS ARE TOO SLOW WITH THE
ONSET...AND DEPARTURE OF THE SNOWFALL WITH THESE CLIPPER SYSTEMS.
THE HIRES RUN OF THE NMM AND ARW EAST SHOW THE PRECIP APPROACHING
THE MN/WI BORDER BY 12Z...SO HAVE INCREASED THE TIMING OF THE POPS.
THE PRECIP SHOULD BE GENERALLY SNOW BEFORE 12Z DUE TO BOTH THE
DIURNAL MINIMUM IN TEMPERATURE...AND THE STRENGTH OF THE FGEN
FORCING. ACCUMULATING SNOW WILL FALL BEYOND THE END OF THIS
PERIOD...BUT STILL HAVE AROUND AN INCH IN THE NORTHWEST CWA BY 12Z
SUNDAY MORNING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 315 AM CDT SAT OCT 19 2013
MAIN FORECAST CONCERN IS PRECIPITATION TYPE SUNDAY/SUNDAY AFTN AS
THE ONSET OF THE STORM SYSTEM SATURDAY NIGHT...MOVES QUICKLY
ACROSS THE CWA BY THE EARLY EVENING. THE LONGER TERM CONCERN IS
WHETHER ANOTHER ALBERTA CLIPPER TYPE OF SYSTEM BRUSHES OUR REGION
WEDNESDAY.
THE MAIN ISSUE REMAINS THE LOWER 1KM OF THE ATMOSPHERIC THERMAL
PROFILE ONCE THE SYSTEM MOVES ACROSS THE REGION LATE TONIGHT...AND
INTO SUNDAY AFTN. INITIALLY...THE MEAN TEMP OF LOWEST 1KM OF THE
WET-BLUB TEMP ARE CLOSE TO 0C. USUALLY THESE TEMPS ARE A GOOD
CORRELATION BETWEEN WHERE IT SNOWS AND WHERE THE CHANGE OVER
OCCURS TO RAIN. THE MAGIC TEMP IS +1.5C OR LOWER FOR MAINLY SNOW.
OVERALL ALL MODELS INITIALLY HAVE THIS TEMP NEAR OR SLIGHTLY BLW
0C AFT MIDNIGHT TONIGHT WHICH MEANS THAT ONCE PRECIPITATION
BEGINS...IT SHOULD BE IN THE FORM OF SNOW. ONLY THE FAR WEST/SW
CWA HAS A CHC OF RAIN OR A MIXTURE OF RAIN/SNOW DUE TO SLIGHTLY
HIGHER TEMPS IN THE LOWEST 1KM. THESE TEMPS QUICKLY RISE AS STRONG
WAA DEVELOPS BY 12Z SUNDAY. BY 18Z SUNDAY...MOST AREAS RISE ABV
THE +1.5C TEMP...WITH ONLY PORTIONS OF CENTRAL MN AND WC WI HAVING
TEMPS CLOSE TO 2C. WITH THIS IN MIND...WILL CONTINUE WITH A
RAIN/SNOW MIXTURE DURING THE MORNING /POSSIBLY ALL SNOW INITIALLY
IN CENTRAL EC MN/...THEN QUICKLY CHANGING TO EITHER ALL RAIN...OR
A MIXTURE OF RAIN/SNOW BY LATE SUNDAY MORNING/EARLY AFTN. AS
DISCUSS PREVIOUSLY...THIS SYSTEM IS FAST WHICH WILL TAKE THE BULK
OF THE PRECIPITATION OUT OF MN BY THE MID/LATE AFTN OF SUNDAY. THE
BEST LOCATION OF REMAINING ALL SNOW WILL OCCUR NORTH OF A LITTLE
FALLS TO MORA TO RUSH CITY LINE IN MINNESOTA...AND NORTH OF A LUCK
TO RICE LAKE TO LADYSMITH LINE IN WISCONSIN. AN INCH OR TWO OF
HEAVY WET SNOW IS POSSIBLE IN THESE AREAS. DUE TO THE WARM
GROUND...MOST OF THE SNOW WILL ONLY ACCUMULATE ON GRASSY SURFACES
AND TREES.
AFTER SUNDAY...THICKNESS VALUES WILL REMAIN COLD ENOUGH FOR MAINLY
SNOW OR SNOW SHOWERS...WITH ONLY A SLIGHT CHANCE OF MIXING WITH
RAIN SHOWERS DURING THE DAYTIME HOURS. ANY SYSTEM THAT MOVES
ACROSS THE AREA NEXT WEEK IS RATHER WEAK COMPARED TO SUNDAY/S
WHICH WILL LEAD TO LITTLE OR NO SNOWFALL ACCUMULATIONS. NEXT WEEK
WILL REMAIN WELL BLW NORMAL WITH ONLY A SLIGHT MODIFICATION BY
LATE IN THE WEEK AND INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 102 PM CDT SAT OCT 19 2013
MVFR CIGS MAY HANG IN THERE THIS AFTERNOON A LITTLE LONGER THAN
PREVIOUSLY THOUGHT. UPPER TROUGH STILL OVER EASTERN MN AND WI AT
MIDDAY. LATEST RAP SHOWS CYCLONIC LOW LEVEL FLOW DOES NOT REALLY
SHIFT EASTWARD ACROSS WESTERN WISCONSIN UNTIL EARLY EVENING. LAMP
HANGS ON A LITTLE LONGER AS WELL...AND SATELLITE TRENDS CERTAINLY
BEAR THIS OUT EVEN IN WEST CENTRAL MN. BUT CELLULAR CU WILL
DISSIPATE AROUND SUNSET. NEXT SYSTEM IN NW FLOW IS QUICK ON ITS
HEELS... WITH MVFR CIGS/VSBYS MOVING INTO WEST CENTRAL MN LATE
TONIGHT. PREVIOUS FORECAST TIMING LOOKS ABOUT RIGHT...THOUGH WILL
ADD SOME DETAIL TO THE ONSET OF PRECIP IN TERMS OF DEVELOPMENT OF MVFR.
KAXN AND KSTC WILL LIKELY SEE IFR CIGS SUNDAY MORNING...CLOSER TO
THE HEAVIER PRECIP...WHERE IT MAY WELL LEAN MORE TO SNOW THAN
RAIN.
KMSP...
MVFR CIGS AROUND 2500 FT AGL WILL REMAIN AROUND KMSP AT LEAST
THROUGH MID AFTERNOON AMID LOW LEVEL CYCLONIC FLOW. WILL NOT BE
SURPRISED IF 2500 FOOT CEILINGS PERSIST UNTIL 23Z OR SO. QUIET
NIGHT WITH BRIEF RIDGE MOVING ACROSS AS LIGHT WINDS SHIFT FROM NW
TO S. NEXT SYSTEM MOVES IN QUICKLY AFTER 12Z...WITH GOOD POTENTIAL
FOR MVFR CEILING/VISIBILITY AROUND 15Z. MIGHT BE SOME WET SNOW
MOVED IN DURING ONSET OF PRECIP TOMORROW...BUT SHOULD GENERALLY BE
RAIN. IT MIGHT END SHORTLY BEFORE 21/00Z BUT NOT SURE YET SO DID
LET IT PERSIST AFTER 15Z AND THROUGH THE BALANCE OF THE FORECAST.
/OUTLOOK FOR KMSP/
MON...VFR WITH -RA/SN POSSIBLE. WINDS NW AT 10G15KT.
TUE...VFR WITH MVFR CIGS POSSIBLE EARLY. WINDS NW AT 10KTS.
WED...VFR WITH MVFR AND -RA/SN POSSIBLE. WINDS SW AT 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...JLT
AVIATION...TDK
AREA FORECAST DISCUSSION...COR
NWS WILMINGTON NC
600 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A LINGERING COLD FRONT OVER THE COASTAL CAROLINAS WILL MOVE OFF
SHORE AS HIGH PRESSURE BUILDS IN THROUGH SUNDAY. THE FRONT WILL
SHIFT BACK TOWARD THE COAST AS HIGH PRESSURE MOVES OFF TO THE
NORTHEAST LATE MONDAY INTO TUESDAY. COLDER HIGH PRESSURE WILL
SLOWLY BUILD INTO THE AREA MID THROUGH LATE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 6 PM SATURDAY...THE LATEST RADAR TRENDS SUGGEST FAVORABLE
DYNAMICS ALOFT ARE BEGINNING TO PLAY A ROLE IN THE UPTREND IN
SHOWER ACTIVITY PRESENTLY. AN UPPER JET CROSSING THE APPALACHIANS
IS PRODUCING A ZONE OF DIFFLUENCE ALOFT OVER CENTRAL CAROLINAS
WHICH IS GRADUALLY EDGING EASTWARD. INITIALLY HIGHER POP VALUES
THIS EVENING ARE PLACED ACROSS OUR WESTERN ZONES...SPREADING OVER
MUCH OF THE FORECAST AREA OVERNIGHT. INSTABILITY OVER THE REGION
REMAINS WEAK AND PRECIPITABLE WATERS HIGH...SO WILL MAINTAIN A
MENTION OF ISOLATED SHOWERS THROUGH 12Z SUNDAY. THE LATEST NAM
MODEL RUN DEPICTS EXPANDING STRATIFORM RAIN OVER THE EASTERN
CAROLINAS AFTER 6Z/2AM TONIGHT INTO DAYBREAK SUNDAY...AS MOISTURE
ALOFT FROM THE SW OVER-RUNS THE LEADING EDGE OF BUILDING HIGH
PRESSURE AND NORTHERLY WIND FLOW IN THE LOW-LEVELS. THIS IS
FEASIBLE AND THE ISENTROPIC OMEGA WOULD HELP SATURATE THE LOW AND
MID LEVELS. WITH THIS IN MIND WE MAY NEED TO BRING POP VALUES UP
WITH THE MID EVENING UPDATE FOR THE DAYBREAK SUNDAY TIME FRAME.
WILL ALSO NEED TO TAKE A CLOSER LOOK AT MINIMUMS FOR DAYBREAK
SUNDAY AS THE RUC UPDATES SUGGEST OVERNIGHT WILL REMAIN MILDER
THAN FORECAST WITH CLOUDS AND POTENTIAL STRATIFORM RAIN IN THE
PRE-DAWN HOURS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...COLD FRONT WILL SHIFT SLIGHTLY FURTHER
SOUTH AND EAST OFF THE COAST THROUGH SUNDAY AS HIGH PRESSURE
BUILDS IN BEHIND IT. THIS WILL ALLOW AREA TO DRY OUT THROUGH
SUNDAY. LOOKS LIKE DRYING OUT MAY BE SLOWER THAN PREVIOUS THOUGHT
WITH INCREASING SUNSHINE THROUGH THE LATE MORNING INTO EARLY
AFTERNOON FROM WEST TO EAST ACROSS FORECAST AREA. STILL A
DISCREPANCY OF 5 TO 10 DEGREES BETWEEN NAM AND MAV GUIDANCE FOR
DEWPOINT TEMPS SUNDAY AFTERNOON WITH THE NAM BEING DRIER. EITHER
WAY...SUNDAY LOOKS TO BE SHAPING UP TO BE A NICE FALL-LIKE DAY
WITH A GOOD DEAL OF AFTERNOON SUNSHINE.
THE HIGH PRESSURE WILL SLIP OFF THE DELMARVA COAST BY MONDAY
MORNING ALLOWING THIS LINGERING FRONT TO SHIFT BACK TOWARD THE
COAST PLAGUING THE AREA WITH CLOUDS AND PCP ONCE AGAIN. COASTAL
SECTIONS MAY BE INTO THE CLOUDS BY DAYBREAK BUT THE CLOUDS AND PCP
WILL SPREAD BACK TOWARD THE NORTH. PERTURBATIONS IN THE SOUTHWEST
FLOW ALOFT WILL AID IN GENERATING CLOUDS AND A WAVE OF LOW
PRESSURE AT THE SURFACE WILL ALSO MOVE ALONG THE BOUNDARY FROM
SOUTHWEST TO NORTHEAST INCREASING PCP CHANCES BY LATE MONDAY NIGHT.
EXPECT MORE IN THE WAY OF CLOUDS THROUGH MONDAY WITH LIGHT PCP
MAINLY OFF SHORE AND CLOSE TO THE COAST BY LATE DAY AND BETTER CHC
OF MEASURABLE PCP OVERNIGHT MONDAY.
COOL AND DRY AIR ADVECTION THROUGH SUNDAY WILL KEEP DAY TIME HIGHS
CLOSER TO 70 AND OVERNIGHT LOWS WILL DROP OUT IN MORE IDEAL
RADIATIONAL COOLING CONDITIONS. CLOUDS TOWARD DAYBREAK COULD
HAMPER TEMP FALLS BUT FOR NOW WILL KEEP WITH READINGS BETWEEN 45
AND 50 MOST PLACES. CLOUDS WILL KEEP TMPS SLIGHTLY COOLER ON
MONDAY ONCE AGAIN AND WARMER OVERNIGHT WITH READINGS IN THE MID
TO UPPER 50S BY MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...UNSETTLED WEATHER TO BEGIN THE PERIOD...BUT
THE STORY OF THE EXTENDED WILL FOCUS PRIMARILY ON THE COLD OUTBREAK
EXPECTED FOR THE END OF THE WEEK.
BROAD MID-LEVEL TROUGHING BEGINS TO SHARPEN AT THE START OF THE
PERIOD...BUT THE TROUGH AXIS REMAINS WEST OF THE LOCAL AREA ON
TUESDAY. THIS DRIVES MOIST SW FLOW THROUGH MUCH OF THE
COLUMN...WHICH IS TAPPED BY WEAK WAVES OF LOW PRESSURE WHICH WILL
MOVE ALONG A STALLED BOUNDARY JUST OFF THE SE COAST. THESE WILL WORK
TOGETHER TO CREATE DECENT PRECIP CHANCES TUESDAY. ONLY LIGHT RAIN IS
EXPECTED WITH .1 TO .25 QPF LIKELY...HIGHEST ALONG THE
COAST...BEFORE DRYING BEGINS LATE TUESDAY NIGHT AS SOME NVA DEVELOPS
ALOFT AND SURFACE FLOW VEERS TO THE W/NW.
THE REST OF THE PERIOD WILL BE DRY...BUT THE COOLEST AIR OF THE
SEASON IS EXPECTED TO FLOOD INTO THE CAROLINAS BEGINNING THURSDAY.
WEDNESDAY WILL BE A TRANSITIONAL DAY WITH DRYING OCCURRING...BUT CAA
DELAYED UNTIL LATE AS THE UPPER TROUGH AXIS MOVES EAST OF THE AREA.
WHILE THIS HAPPENS...STRONG CYCLOGENESIS OCCURS OFF THE NEW ENGLAND
COAST...WHICH DRIVES THE SECONDARY COLD FRONT OVER THE AREA AND
HELPS STRONG CAA DEVELOP IN ADVANCE OF A CANADIAN HIGH SINKING SOUTH
ACROSS THE CENTRAL PLAINS. THIS HIGH WILL THEN SLOWLY MIGRATE
EAST...BECOMING OVERHEAD THE CAROLINAS SATURDAY.
WHILE TUESDAY WILL BE UNSETTLED WITH TEMPS AROUND CLIMO...AND
WEDNESDAY WILL BE SIMILAR BUT DRY...MUCH COOLER AIR EXPECTED
THU-SAT. GUIDANCE DISAGREES ON JUST HOW COLD IT WILL GET HERE...BUT
ATTM SUPPORT THE COOLER GFS DUE TO STRONG CAA BEHIND THE LOW
PRESSURE OFF THE NE COAST. THIS DRAGS 850MB TEMPS BELOW
0C...SUPPORTING HIGHS IN THE MID 60S AND LOWS IN THE 40S. AS THE
HIGH MOVES OVERHEAD FRI INTO SAT...GRADIENT WILL RELAX...AND
SATURDAY MAY END UP BEING THE COLDEST OF THE PERIOD...WITH SATURDAY
MORNING LOWS IN SOME PLACES DROPPING INTO THE 30S.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...PRECIPITATION WILL COME TO AN END ALONG THE COAST
SHORTLY AFTER TAF ISSUANCE AS A SHORT WAVE MOVES FAIRLY RAPIDLY TO
THE NORTHEAST. SOME DRYING THIS AFTERNOON IS EXPECTED IN THE MID
LEVELS...BUT RETURNING SOMEWHAT TONIGHT AS A COLD FRONT APPROACHES.
LOOK FOR FROPA AROUND 06-08Z WITH A WIND SHIFT TO THE NORTH
NORTHWEST AND A MID CLOUD CEILING...POST FRONTAL. SUNDAY...SKIES
WILL BECOME SCATTERED BY MID TO LATE MORNING AND WINDS WILL BECOME
GUSTY WITH MODERATE COLD AIR ADVECTION.
EXTENDED OUTLOOK...VFR THROUGH THE EXTENDED. LIGHT RAIN DEVELOPING
TUESDAY MORNING INTO WEDNESDAY IN ASSOCIATION WITH AN APPROACHING
FRONTAL SYSTEM.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6 PM SATURDAY...HIGH PRESSURE APPROACHING FROM THE WEST WILL
BRING A WIND-SHIFT TO NORTH TO THE COASTAL WATERS AROUND 2AM OVER
THE NC WATERS AND BY 5AM SOUTH CAROLINA WATERS. THIS SURGE OF
NORTH WIND WILL BRING INCREASING WIND SPEEDS OF 15 KT AND GUSTY
INTO EARLY SUNDAY...ALTHOUGH THE MAINLY NORTH TRAJECTORY/OFFSHORE
WILL KEEP SEAS RELATIVELY SMALL INSHORE...WITH LARGEST SEAS OUTER
PORTION. THE MODERATE NORTH CHOP WILL INTERACT WITH 2 FT OF ESE
WAVES IN 8-9 SECOND INTERVALS. SHOWERS AND ISOLATED TSTMS WILL BE
POSSIBLE OVERNIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY
NIGHT/... AS OF 3 PM SATURDAY...FRONT WILL BE SHIFTING SOUTH AND
EAST AND SHOULD CLEAR LOCAL WATERS BY SUNDAY MORNING. HIGH
PRESSURE WILL BUILD IN BEHIND IT WITH NORTHERLY WINDS AROUND 10 TO
15 KTS. WINDS WILL VEER AROUND TO THE NORTHEAST SUNDAY NIGHT INTO
MONDAY AS HIGH PRESSURE MOVES OFF THE DELMARVA COAST. MAY SEE
SLIGHT SPIKE IN WINDS AND SEAS SUNDAY NIGHT IN COOL AND DRY
ADVECTION. WINDS WILL WEAKEN THROUGH MONDAY INTO MONDAY NIGHT AS
FRONT SHIFTS BACK NORTHWEST TOWARD THE CAPE FEAR COAST. OVERALL
LIGHT WIND FLOW WILL MAINTAIN SEAS 2 TO 3 FT BUT MAY SEE A FEW 4
FTERS IN OUTER WATERS SUNDAY NIGHT.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...STALLED BOUNDARY ACROSS THE WATERS WILL KEEP
WINDS LIGHT AND GENERALLY OUT OF THE NORTH TUE. PASSAGE OF WEAK
SURFACE WAVE DURING THE DAY TUE MAY RESULT IN WINDS BECOMING MORE
VARIABLE BUT LITTLE CHANGE TO GRADIENT...AND THUS WIND SPEED...IS
EXPECTED. NORTHWEST FLOW DEVELOPS IN ERNEST WED WITH WINDS
BECOMING 10 TO 15 KT. WINDS COULD BECOME GUSTY WED NIGHT AS FIRST
ROUND OF COLD ADVECTION BEGINS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
145 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION LATE THIS EVENING. WEAK HIGH
PRESSURE WILL BUILD OVER THE AREA THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM SATURDAY...
THROUGH THIS EVENING...
20-30KT OF 925/850MB FLOW AND WEAK ISENTROPIC LIFT BETWEEN A COASTAL
FRONT AND AN 850MB FRONT OVER THE WESTERN PIEDMONT CONTINUES TO
SUPPORT AREAS OF LIGHT RAIN THIS MORNING...MAINLY OVER THE FOOTHILLS
AND WESTERN PIEDMONT. UPPER DIVERGENCE ASSOCIATED WITH THE RIGHT
ENTRANCE REGION OF A 150KT 300MB JET WEST OF THE MOUNTAINS SHOULD
OFFER ADDITIONAL LIFT THROUGH THIS AFTERNOON...WHILE THE MAIN AXIS
OF DEEP MOISTURE SHIFTS EASTWARD ACROSS THE CWA AHEAD OF AN UPPER
TROUGH THAT WILL BEGIN TO LIFT OUT OF THE MID MISSISSIPPI VALLEY
REGION. MODELS STILL SHOW QUITE A BIT OF DRYING CENTERED AROUND
850MB AFTER 18Z AS THE FLOW VEERS TO A BIT MORE
WEST-SOUTHWESTERLY...WHICH SHOULD EFFECTIVELY SHUT OFF THE LIGHT
PRECIP...EVEN AS THE NORTHWESTERN PORTION OF THE CWA GETS A GLANCING
BLOW OF 60M HEIGHT FALLS AND THE COLD FRONT ENTERS THE AREA FROM THE
WEST. WILL EXTEND A CHANCE POP INTO THE AFTERNOON BEFORE BRINGING
POPS TO AN END FROM WEST TO EAST THIS EVENING WITH THE IMPENDING
FRONTAL PASSAGE.
THE LIGHT RAIN OVERNIGHT HAS LEFT A WEAK STABLE LAYER NEAR THE
SURFACE AND WIDESPREAD LOW STRATUS. DRY AIR ADVECTING IN FROM THE
SOUTHWEST WILL SLOWLY ERODE THE LOW CLOUDS TODAY...BUT EXPECT THE
LOW CLOUDS WILL LINGER INTO THE AFTERNOON WITHOUT A SIGNIFICANT
EROSION MECHANISM PRIOR TO THE COLD FRONT THIS EVENING. EVEN AS THE
LOW CLOUDS BREAK...THERE WILL ABUNDANT MID AND HIGH CLOUDS TO TEMPER
HIGHS. THE LATEST RAP RUNS APPEAR TO HAVE A BETTER HANDLE OF
THIS...SO HAVE ADJUSTED TEMPS TOWARD THE RAP AND LOCAL WRF
ARW...WHICH SHOW A SLOW WARMING TREND THROUGH EARLY AFTERNOON.
HIGHS SHOULD END UP IN THE MID 60S ACROSS THE NORTHERN AREAS AND
POSSIBLE THE LOWER 70S ACROSS THE SOUTH. -SMITH
TONIGHT...
SHEARED SHORTWAVE TROUGH LIFTING NEWD INTO THE GREAT LAKES
AND NORTHEAST WILL DRAG THE TRAILING SFC COLD FRONT ACROSS THE THE
MOUNTAINS LATE THIS AFTERNOON AND ACROSS CENTRAL NC THIS EVENING
BETWEEN 00 TO 06Z. LIMITED MOISTURE...WEAK FORCING AND THE LACK OF
INSTABILITY WILL PREEMPT ANY PRECIP WITH DRY COLD AIR ADVECTION FOR
THE SECOND HALF OF THE NIGHT SPREADING WEST TO EAST. MUCH COOLER
WITH LOWS RANGING FROM MID 40S NW TO LOWER 50S SE. -CBL
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 240 AM SATURDAY...
POST-FRONTAL CAA REGIME SUNDAY MORNING WILL RESULT IN
LOW-LEVEL THICKNESSES STARTING OUT A GOOD 30 METERS BELOW
NORMAL...MORE REPRESENTATIVE OF LATE NOVEMBER THAN LATE OCTOBER.
IN-HOUSE TEMPERATURE FORECASTING TECHNIQUES ARE A GOOD 4 TO 6
DEGREES COOLER THAN MOS STATISTICAL GUIDANCE WITH FORECAST HIGHS ON
SUNDAY. UNDER COMPLIMENTS OF FULL SUNSHINE...EXPECT AFTERNOON HIGHS
IN THE LOWER TO MID 60S ACROSS THE PIEDMONT/NORTHERN COASTAL
PLAIN...TO MID/UPPER 60S SOUTH.
UPPER HEIGHTS LEVEL OUT A BIT OVER THE REGION AS LONG WAVE TROUGH
CENTERED BACK OVER THE CENTRAL US AWAITS RE-LOADING FROM A
SUCCESSION OF BOTH PACIFIC NW AND CANADIAN S/W ENERGY DIVING SEWD
THROUGH THE NATIONS MID-SECTION. THUS...SWLY FLOW ALOFT WILL
CONTINUE WITH LATEST GFS SHOWING A RESURGENCE OF HIGH-LEVEL MOISTURE
BACK ACROSS THE AREA LATE SUNDAY NIGHT...ESPECIALLY ACROSS THE
SOUTHERN HALF. WILL HAVE TO MONITOR CLOUD TRENDS AS THESE HIGHS
CLOUDS COULD MODULATE WHAT OTHERWISE WOULD BE GOOD RADIATIONAL
CONDITIONS WITH SFC HIGH PRESSURE CENTERED OVER THE AREA. LOWS IN
THE LOWER TO MID 40S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 240 AM SATURDAY...
THE UPPER LEVEL LOW OVER SOUTH CENTRAL CANADA MONDAY WILL SWING
THROUGH THE GREAT LAKES REGION AND INTO NORTHEAST CANADA THROUGH
FRIDAY...WITH THE TROUGH SLOWLY PROGRESSING EAST FROM THE MIDWEST TO
THE ATLANTIC COAST. AT THE SURFACE...HIGH PRESSURE TO START THE
PERIOD WILL BE PUSHED NORTH AND EAST OFFSHORE BY A COLD FRONT MOVING
THROUGH THE CAROLINAS BY MID-WEEK. BEHIND THE FRONT...HIGH PRESSURE
WILL BUILD IN...BRINGING WITH IT A COOLER DRIER POLAR AIRMASS...
WHICH SHOULD LINGER THROUGH THE REMAINDER OF THE PERIOD. MODELS
INDICATE A SURGE OF MOISTURE FROM THE GULF MOVING INTO CENTRAL AND
EASTERN NC TUESDAY...AHEAD OF THE COLD FRONTAL PASSAGE...WHICH COULD
BRING AN INCREASE IN UPPER AND MID LEVEL CLOUD COVER MONDAY EVENING
AND INTO THE OVERNIGHT. WITH THE LATEST MODEL SOLUTIONS...EXPECT
BEST CHANCES FOR RAIN TO BE ACROSS THE EAST TUESDAY. ALTHOUGH THERE
MAY BE SOME LINGERING LOW LEVEL MOISTURE ACROSS THE AREA WEDNESDAY
AND WEDNESDAY NIGHT AND LIGHT RAIN CANNOT BE RULED OUT COMPLETELY...
DRY AIR IS EXPECTED TO BE IN PLACE AT THE MID AND UPPER LEVELS...
WITH NORTH TO NORTHWEST FLOW IN THE LOW LEVELS...WHICH SHOULD HELP
TO INHIBIT ADDITIONAL RAINFALL. AS FOR TEMPERATURES...WILL SEE A
STEADY DECREASE IN HIGHS THROUGH THE PERIOD...BEGINNING IN THE UPPER
60S TO LOW 70S ON MONDAY AND UPPER 50S TO MID 60S BY FRIDAY. EXPECT
OVERNIGHT LOWS TO BE THE COOLEST OF THE SEASON BY MID TO LATE IN THE
PERIOD...STARTING IN THE UPPER 40S TO LOW 50S MONDAY NIGHT...
DECREASING INTO THE MID 30S TO LOW 40S BY WEDNESDAY NIGHT...HOLDING
THROUGH THE END OF THE PERIOD.
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 PM SATURDAY...
24-HOUR TAF PERIOD...
LIGHT RAIN CONTINUES TO STREAM ACROSS THE WESTERN PIEDMONT THIS
AFTERNOON...AND LOW CEILINGS HAVE HELD ACROSS NEARLY ALL OF CENTRAL
NC. HOWEVER... THESE IFR CEILINGS ARE BEGINNING TO ERODE FROM THE
SOUTHWEST AND MVFR OR VFR CONDITIONS SHOULD DEVELOP AT ALL SITES BY
20-21Z. AS THIS DRIER AIR MOVES IN FROM THE WEST AND
SOUTHWEST...PRECIP IS BEGINNING TO DIMINISH...AND THE COLD FRONT
FORECAST TO CROSS THE AREA LATE THIS EVENING SHOULD BE MOSTLY DRY.
WINDS WILL SHIFT TO NORTHWESTERLY BEHIND THE FRONT BUT WILL REMAIN
BELOW 12KT. VFR CONDITIONS AND LIGHT NORTH-NORTHWESTERLY WINDS WILL
CONTINUE THROUGH THE TAF PERIOD.
LOOKING AHEAD:
HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS NC EARLY NEXT WEEK.
THERE IS A SMALL CHANCE OF SUB-VFR CONDITIONS RETURNING BY THE
MIDDLE OF NEXT WEEK...MAINLY AT EASTERN SITES...AS A FRONTAL ZONE
LINGERS NEAT THE COAST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...CBL/SMITH
SHORT TERM...CBL
LONG TERM...KMC
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
541 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION THIS EVENING FOLLOWED
BY A VISIT FROM HIGH PRESSURE ON SUNDAY AND MONDAY. THE PATTERN
WILL TURN NOTICEABLY COOLER AND UNSETTLED NEXT WEEK AS AN UPPER
TROUGH ESTABLISHES ITSELF OVER THE EASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
EARLY EVENING REGIONAL RADAR LOOP SHOWING WIDESPREAD SHOWERS
FALLING ACROSS MOST OF CENTRAL PA...ALONG AXIS OF SOUTHERLY LL
JET/HIGHEST PWATS AHEAD OF APPROACHING COLD FRONT. FINE LINE OF
HIGHER RETURNS ALONG COLD FRONT NOTED ON THE OH/PA BORDER. AS CD
FRONT SWEEPS EAST...WOULDN/T BE SURPRISED TO SEE A COUPLE
LIGHTNING STRIKES ACROSS NORTH CENTRAL PA...WHERE NR TERM MDLS
PLACE SOME MARGINAL INSTABILITY.
LATEST RAP OUTPUT TIMES CDFRONT INTO THE W MTNS ARND 01Z AND
CLEARING THE EASTERNMOST COUNTIES /SCHUYLKILL AND LANCASTER/ BY
MIDNIGHT. WESTERLY FLOW OF MUCH DRIER AIR BEHIND THE FRONT WILL
SHUT OFF RAINFALL OVER NEARLY ALL OF THE AREA LATER THIS
EVENING...WITH THE POSSIBLE EXCEPTION OF THE NW MTNS...WHERE LAKE
EFFECT -SHRA COULD LINGER BEHIND FRONT. A MID-LAKE BAND WILL
PROBABLY DEVELOP ON GOOD INSTABILITY UNDER THE COLD AIR...AND WRLY
FLOW WILL MAKE IT JUST BRUSH AREAS N OF ROUTE 6 TONIGHT AND INTO
SUN MORNING.
CLEARING SHOULD TAKE PLACE OVER THE DOWNSLOPE AREAS OF THE CWA IN
THE POST-FRONTAL FLOW. THE INITIALLY GUSTY WEST WINDS WILL STAY UP
FOR MUCH OF THE NIGHT...BUT COULD SLACKEN IN THE DEEPER VALLEYS.
WILL LEAVE OUT MENTIONS OF VALLEY FOG AT THIS POINT WITH DEWPOINTS
FALLING INTO THE 30S AND WIND STILL GOING ALL NIGHT. BUT IT IS
TOUGH TO KEEP IT FROM FORMING WHEN AIR TEMP IS IN THE 30S AND
WATER MUCH WARMER.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
HIGH PRESSURE TO THE SOUTH OF THE STATE LOOKS VERY SIMILAR TO WHAT
THE PATTERN WAS ON FRIDAY. BUT...MUCH LESS MOISTURE AROUND...SO
THIS SHOULD LEAD TO MORE SUNSHINE. DIURNAL CU IS LIKELY OVER THE
HIGHER ELEVATIONS OF THE ALLEGHENIES...BUT COVERAGE SHOULD BE SCT
AT WORST. THE CLOUDS AND ANY SPRINKLES IN THE FAR NRN TIER SHOULD
LIFT TO THE NORTH THROUGH THE MORNING AND LEAVE A FAIR DAY THERE
AS WELL. WIND WILL INCREASE A BIT FROM ANY MORNING LULL AS THE
ATMOS MIXES. MAXES UNDER THE RATHER HOMOGENEOUS 0C-M2C 8H TEMPS
WILL BE ALMOST ENTIRELY DEPENDENT ON ELEVATION AND DOWNSLOPE
WARMING. THUS...MAXES CLOSE TO 50F IN THE NW MTS AND NEAR 60F IN
THE VALLEYS/LOWER ELEVS OF THE SUSQ VALLEY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
CENTRAL PA WILL BE ON NORTHERN EDGE OF ERODING HIGH PRESSURE RIDGE
SUN NIGHT INTO MON...WITH A WARM FRONT LIFTING THROUGH OHIO VALLEY
AND SKIRTING W PA. THIS WILL KEEP WEATHER FAIR AND MILD...WITH
HIGHS MONDAY SLIPPING INTO THE 60S /ABOUT 4-8F ABOVE NORMAL/.
THINGS START TO GO DOWNHILL MONDAY NIGHT AS NEW ENERGY STARTS
DIVING OUT OF SOUTHERN CANADA ON THE WAY TO CARVING OUT A LARGE
SCALE PERSISTENT TROF OVER THE EASTERN U.S. A BUILDING RIDGE OVER
THE WEST COAST WILL HELP DEEPEN AN ADVANCING LOW...WHICH WILL
DELIVER A STEADY FEED OF INCREASINGLY MORE CHILLY AIR ACROSS THE
UPPER MIDWEST NEXT WEEK. THIS COLD AIR WILL PROPAGATE INTO THE
LOWER LAKES AND LOCAL AREA IN THE WAKE OF A COLD FRONTAL BOUNDARY
PROGGED FOR TUESDAY...AND REINFORCED BY SECONDARY TROUGH ON
WEDNESDAY /AS ANOTHER LOW FORMS ALONG THE BOUNDARY AND SLIDES
ACROSS MID ATLANTIC STATES JUST TO OUR SOUTH BEFORE SLIDING OFF
THE COAST OF NEW ENGLAND/.
SOME DIFFERENCES CONTINUE IN MODEL SOLUTIONS STARTING AROUND
WEDNESDAY WHEN THE ECMWF BRINGS A STRONG SHORTWAVE OUT OF THE
OHIO VALLEY. THE OPERATIONAL GFS AND THE GEFS /PREVIOUSLY WITH A
FLATTER TROUGH/ ARE COMING MORE IN LINE WITH THE EC...WHICH WILL
INCREASE OUR POP CHANCES FOR WED WITH A STEADY LIGHT RAIN POSS.
AFTER THAT...CYCLONIC FLOW WILL CONTINUE TO ALLOW INCREASINGLY
COOLER AIR TO FILTER IN ON NW FLOW. PLENTY OF COLD ADVECTION
STRATOCU AND LAKE/OROGRAPHIC SHOWERS LOOKING LIKELY IN THE HIGHER
WESTERN TERRAIN MID/LATE WEEK...WITH DOWNSLOPE COMPONENT TO WINDS
KEEPING PRECIP AT A MIN FOR THE SE. LOW LEVEL TEMPS GET COLD
ENOUGH /850MB TEMPS DIP BELOW 0C/ THAT LIGHT SHOWERS COULD BE
MIXED WITH WET SNOW DURING THE CHILLIEST PART OF THE DAY AND
OVERNIGHT.
HIGH PRESSURE BUILDS IN LOW LEVELS FOR THE WEEKEND...BRINGING
QUITE CHILLY MORNING TEMPS. BUT AN OVERALL MORE SETTLED WEATHER
PATTERN. REINFORCING SHOT OF COLDER AIR POSS EARLY NEXT WEEK.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
EXCEPT FOR KUNV...ALL CENTRAL PA AIRFIELDS REPORTING VFR
CONDITIONS LATE THIS AFTERNOON...DESPITE A GOOD DEAL OF RAIN AND
SHOWERS MOVING THROUGH THE REGION. SURFACE ANALYSIS SHOWS A BAND
OF LOWER MVFR TO IFR CIGS WITH AND DIRECTLY BEHIND THE APPROACHING
COLD FRONT...SO HAVE INCLUDED THIS PERIOD OF LOWERING CIGS IN TAFS.
FROPA TIMED AT KBFD BETWEEN 23Z AND 00Z...IN CENTRAL AREAS SUCH AS
KUNV BETWEEN 01Z AND 02Z...AND ACROSS THE EASTERN AIRFIELDS
BETWEEN 03Z AND 04Z. AGAIN...DRAMATIC WIND SHIFT TO THE WEST...AND
A BAND OF LOWER CIGS WILL ACCOMPANY THE FRONT.
HIGH PRESSURE BUILDS TO THE WEST FROM THE TENNESSEE VALLEY...BUT
STAYS FAR ENOUGH AWAY TO KEEP SOME GRADIENT WIND...GENERALLY
10 TO 12 KTS...DURING THE DAY ON SUNDAY WITH OTHERWISE VFR
CONDITIONS. SHOWERS MAY LINGER LATE TONIGHT AND VERY EARLY SUN
A.M. VCTY BFD. BUT EVEN AT BFD IMPROVEMENT TO VFR WILL OCCUR IN
THE MORNING.
MONDAY LOOKS FAIR/VFR AS HIGH PRESSURE SLIDES TO THE EAST COAST
AND RETURN FLOW BEGINS. MORE COLD AIR ARRIVES WITH THE NEXT COLD
FRONT MON NIGHT AND TUESDAY.
OUTLOOK...
TUE...FROPA. MVFR/IFR POSS DUE TO SHOWERS/CLOUDS...ESP NW.
WED...MVFR POSS IN SHRA...ESP NW.
THURS...BREEZY...MVFR CLOUDS/SHRA N/W.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...DANGELO/FITZGERALD
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...JUNG/DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
519 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION THIS EVENING FOLLOWED
BY A VISIT FROM HIGH PRESSURE ON SUNDAY AND MONDAY. THE PATTERN
WILL TURN NOTICEABLY COOLER AND UNSETTLED NEXT WEEK AS AN UPPER
TROUGH ESTABLISHES ITSELF OVER THE EASTERN UNITED STATES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
EARLY EVENING REGIONAL RADAR LOOP SHOWING WIDESPREAD SHOWERS
FALLING ACROSS MOST OF CENTRAL PA...ALONG AXIS OF SOUTHERLY LL
JET/HIGHEST PWATS AHEAD OF APPROACHING COLD FRONT. FINE LINE OF
HIGHER RETURNS ALONG COLD FRONT NOTED ON THE OH/PA BORDER. AS CD
FRONT SWEEPS EAST...WOULDN/T BE SURPRISED TO SEE A COUPLE
LIGHTNING STRIKES ACROSS NORTH CENTRAL PA...WHERE NR TERM MDLS
PLACE SOME MARGINAL INSTABILITY.
LATEST RAP OUTPUT TIMES CDFRONT INTO THE W MTNS ARND 01Z AND
CLEARING THE EASTERNMOST COUNTIES /SCHUYLKILL AND LANCASTER/ BY
MIDNIGHT. WESTERLY FLOW OF MUCH DRIER AIR BEHIND THE FRONT WILL
SHUT OFF RAINFALL OVER NEARLY ALL OF THE AREA LATER THIS
EVENING...WITH THE POSSIBLE EXCEPTION OF THE NW MTNS...WHERE LAKE
EFFECT -SHRA COULD LINGER BEHIND FRONT. A MID-LAKE BAND WILL
PROBABLY DEVELOP ON GOOD INSTABILITY UNDER THE COLD AIR...AND WRLY
FLOW WILL MAKE IT JUST BRUSH AREAS N OF ROUTE 6 TONIGHT AND INTO
SUN MORNING.
CLEARING SHOULD TAKE PLACE OVER THE DOWNSLOPE AREAS OF THE CWA IN
THE POST-FRONTAL FLOW. THE INITIALLY GUSTY WEST WINDS WILL STAY UP
FOR MUCH OF THE NIGHT...BUT COULD SLACKEN IN THE DEEPER VALLEYS.
WILL LEAVE OUT MENTIONS OF VALLEY FOG AT THIS POINT WITH DEWPOINTS
FALLING INTO THE 30S AND WIND STILL GOING ALL NIGHT. BUT IT IS
TOUGH TO KEEP IT FROM FORMING WHEN AIR TEMP IS IN THE 30S AND
WATER MUCH WARMER.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
HIGH PRESSURE TO THE SOUTH OF THE STATE LOOKS VERY SIMILAR TO WHAT
THE PATTERN WAS ON FRIDAY. BUT...MUCH LESS MOISTURE AROUND...SO
THIS SHOULD LEAD TO MORE SUNSHINE. DIURNAL CU IS LIKELY OVER THE
HIGHER ELEVATIONS OF THE ALLEGHENIES...BUT COVERAGE SHOULD BE SCT
AT WORST. THE CLOUDS AND ANY SPRINKLES IN THE FAR NRN TIER SHOULD
LIFT TO THE NORTH THROUGH THE MORNING AND LEAVE A FAIR DAY THERE
AS WELL. WIND WILL INCREASE A BIT FROM ANY MORNING LULL AS THE
ATMOS MIXES. MAXES UNDER THE RATHER HOMOGENEOUS 0C-M2C 8H TEMPS
WILL BE ALMOST ENTIRELY DEPENDENT ON ELEVATION AND DOWNSLOPE
WARMING. THUS...MAXES CLOSE TO 50F IN THE NW MTS AND NEAR 60F IN
THE VALLEYS/LOWER ELEVS OF THE SUSQ VALLEY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
CENTRAL PA WILL BE ON NORTHERN EDGE OF ERODING HIGH PRESSURE RIDGE
SUN NIGHT INTO MON...WITH A WARM FRONT LIFTING THROUGH OHIO VALLEY
AND SKIRTING W PA. THIS WILL KEEP WEATHER FAIR AND MILD...WITH
HIGHS MONDAY SLIPPING INTO THE 60S /ABOUT 4-8F ABOVE NORMAL/.
THINGS START TO GO DOWNHILL MONDAY NIGHT AS NEW ENERGY STARTS
DIVING OUT OF SOUTHERN CANADA ON THE WAY TO CARVING OUT A LARGE
SCALE PERSISTENT TROF OVER THE EASTERN U.S. A BUILDING RIDGE OVER
THE WEST COAST WILL HELP DEEPEN AN ADVANCING LOW...WHICH WILL
DELIVER A STEADY FEED OF INCREASINGLY MORE CHILLY AIR ACROSS THE
UPPER MIDWEST NEXT WEEK. THIS COLD AIR WILL PROPAGATE INTO THE
LOWER LAKES AND LOCAL AREA IN THE WAKE OF A COLD FRONTAL BOUNDARY
PROGGED FOR TUESDAY...AND REINFORCED BY SECONDARY TROUGH ON
WEDNESDAY /AS ANOTHER LOW FORMS ALONG THE BOUNDARY AND SLIDES
ACROSS MID ATLANTIC STATES JUST TO OUR SOUTH BEFORE SLIDING OFF
THE COAST OF NEW ENGLAND/.
SOME DIFFERENCES CONTINUE IN MODEL SOLUTIONS STARTING AROUND
WEDNESDAY WHEN THE ECMWF BRINGS A STRONG SHORTWAVE OUT OF THE
OHIO VALLEY. THE OPERATIONAL GFS AND THE GEFS /PREVIOUSLY WITH A
FLATTER TROUGH/ ARE COMING MORE IN LINE WITH THE EC...WHICH WILL
INCREASE OUR POP CHANCES FOR WED WITH A STEADY LIGHT RAIN POSS.
AFTER THAT...CYCLONIC FLOW WILL CONTINUE TO ALLOW INCREASINGLY
COOLER AIR TO FILTER IN ON NW FLOW. PLENTY OF COLD ADVECTION
STRATOCU AND LAKE/OROGRAPHIC SHOWERS LOOKING LIKELY IN THE HIGHER
WESTERN TERRAIN MID/LATE WEEK...WITH DOWNSLOPE COMPONENT TO WINDS
KEEPING PRECIP AT A MIN FOR THE SE. LOW LEVEL TEMPS GET COLD
ENOUGH /850MB TEMPS DIP BELOW 0C/ THAT LIGHT SHOWERS COULD BE
MIXED WITH WET SNOW DURING THE CHILLIEST PART OF THE DAY AND
OVERNIGHT.
HIGH PRESSURE BUILDS IN LOW LEVELS FOR THE WEEKEND...BRINGING
QUITE CHILLY MORNING TEMPS. BUT AN OVERALL MORE SETTLED WEATHER
PATTERN. REINFORCING SHOT OF COLDER AIR POSS EARLY NEXT WEEK.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
HIGHER-END MVFR CIGS AND LOWER-END VFR CIGS EXPECTED THIS EVENING
AS THE COLD FRONT AND ASSOCD SHOWERS PUSH THROUGH FROM W-E.
SHOWERS OVER THE CENTRAL MTS WILL BE THE MAIN STORY AND COULD MAKE
GUSTS INTO THE L20S AT THE EASTERN TERMINALS AS THEY COAGULATE IN
THE NEXT HOUR OR SO. THE LIGHT RAIN TO THE WEST OF THE AREA WILL
LIKELY BEGIN TO DISSIPATE AS IT REACHES A BFD-JST LINE. THE DRY
AIR AT THE SFC WILL MAKE IT EASY FOR THE HUSTY WINDS BEHIND THE
FRONT TO MIX DOWN EARLY TONIGHT...BUT SOME DECOUPLING IS POSSIBLE
IN THE DEEPER VALLEYS IN THE MORNING. CLOUDS SHOULD DECREASE
RAPIDLY TONIGHT OVER THE SERN HALF OF THE FORECAST AREA. HIGH
PRESSURE BUILDS TO THE WEST FROM THE TN VALLEY...BUT STAYS FAR
ENOUGH AWAY TO KEEP SOME GRADIENT WIND - GENERALLY 10-12 KTS
DURING THE DAY ON SUNDAY WITH OTHERWISE VFR CONDITIONS. SHOWERS
MAY LINGER LATE TONIGHT AND VERY EARLY SUN A.M. VCTY BFD. BUT EVEN
AT BFD IMPROVEMENT TO VFR WILL OCCUR IN THE MORNING.
MONDAY LOOKS FAIR/VFR AS HIGH PRESSURE SLIDES TO THE EAST COAST
AND RETURN FLOW BEGINS. MORE COLD AIR ARRIVES WITH THE NEXT COLD
FRONT MON NIGHT AND TUESDAY.
OUTLOOK...
TUE...FROPA. MVFR/IFR POSS DUE TO SHOWERS/CLOUDS...ESP NW.
WED...MVFR POSS IN SHRA...ESP NW.
THURS...BREEZY...MVFR CLOUDS/SHRA N/W.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...DANGELO/FITZGERALD
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
253 PM EDT SAT OCT 19 2013
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION THIS EVENING FOLLOWED
BY A VISIT FROM HIGH PRESSURE ON SUNDAY AND MONDAY. THE PATTERN
WILL TURN NOTICEABLY COOLER AND UNSETTLED NEXT WEEK AS AN UPPER
TROUGH ESTABLISHES ITSELF OVER THE EASTERN UNITED STATES.
&&
.NEAR TERM /THROUGH TONIGHT/...
DRY AIR SEEMS TO BE WINNING OUT AT THIS POINT...AND LITTLE PRECIP
HAS FALLEN. DEWPOINTS HAVE NOT RISEN PAST THE M40S. LITTLE
MOISTURE AVAILABLE...BUT LOWER ATMOS IS TRYING TO MOISTEN UP.
EXPECT THE SHOWERS OVER THE CENTRAL MTS TO CONTINUE DEVELOPING IN
THE IDEA OF THE HRRR AND RUC RUNS OF THE LAST FEW HRS.
THUS...THESE SHOULD BE THE MOST NUMEROUS SHOWERS AND MOVE TO THE
EAST THROUGH THE VERY EARLY EVENING. THESE SHOWERS SHOULD BE OFF
TO THE EAST OF THE CWA BY 8 PM. THE RAIN OVER NRN OH AND FAR WRN
PA IS FEEDING ON POOR DEWPOINTS AS WELL. WILL PAINT THE HIGHEST
POPS IN THE NW AND ALSO FROM UNV TO THE EAST. JUST SCT SHOWERS
WILL BE LEFT ALONG THE NY BORDER AND PERHAPS IN THE LAURELS FOR
THE EARLY PART OF THE NIGHT. A MID-LAKE BAND WILL PROBABLY DEVELOP
ON GOOD INSTABILITY UNDER THE COLD AIR...AND WRLY FLOW WILL MAKE
IT JUST BRUSH AREAS N OF ROUTE 6 TONIGHT AND INTO SUN MORNING.
CLEARING SHOULD TAKE PLACE OVER THE DOWNSLOPE AREAS OF THE CWA IN
THE POST-FRONTAL FLOW. THE INITIALLY GUSTY WEST WINDS WILL STAY
UP FOR MUCH OF THE NIGHT...BUT COULD SLACKEN IN THE DEEPER
VALLEYS. WILL LEAVE OUT MENTIONS OF VALLEY FOG AT THIS POINT WITH
DEWPOINTS FALLING INTO THE 30S AND WIND STILL GOING ALL NIGHT. BUT
IT IS TOUGH TO KEEP IT FROM FORMING WHEN AIR TEMP IS IN THE 30S
AND WATER MUCH WARMER.
&&
.SHORT TERM /SUNDAY/...
HIGH PRESSURE TO THE SOUTH OF THE STATE LOOKS VERY SIMILAR TO WHAT
THE PATTERN WAS ON FRIDAY. BUT...MUCH LESS MOISTURE AROUND...SO
THIS SHOULD LEAD TO MORE SUNSHINE. DIURNAL CU IS LIKELY OVER THE
HIGHER ELEVATIONS OF THE ALLEGHENIES...BUT COVERAGE SHOULD BE SCT
AT WORST. THE CLOUDS AND ANY SPRINKLES IN THE FAR NRN TIER SHOULD
LIFT TO THE NORTH THROUGH THE MORNING AND LEAVE A FAIR DAY THERE
AS WELL. WIND WILL INCREASE A BIT FROM ANY MORNING LULL AS THE
ATMOS MIXES. MAXES UNDER THE RATHER HOMOGENEOUS 0C-M2C 8H TEMPS
WILL BE ALMOST ENTIRELY DEPENDENT ON ELEVATION AND DOWNSLOPE
WARMING. THUS...MAXES CLOSE TO 50F IN THE NW MTS AND NEAR 60F IN
THE VALLEYS/LOWER ELEVS OF THE SUSQ VALLEY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
MONDAY WILL BEGIN THE EXTENDED ON THE FAIR AND MILD SIDE AS THE
HIGH REMAINS IN CONTROL FOR ONE MORE DAY. THINGS START TO GO
DOWNHILL MONDAY NIGHT AS NEW ENERGY STARTS DIVING OUT OF SOUTHERN
CANADA ON THE WAY TO CARVING OUT A LARGE SCALE TROF OVER THE
EASTERN US.
THE BUILDING RIDGE OVER THE WEST COAST...AIDED BY A STRONG
TYPHOON THAT PASSED EAST OF JAPAN SEVERAL DAYS AGO...WILL HELP
DEEPEN AN ADVANCING LOW WHICH WILL DELIVER INCREASINGLY CHILLY
AIR THROUGH THE UPPER MID WEST NEXT WEEK. THIS COLD AIR WILL
PROPAGATE INTO THE LOWER LAKES AND LOCAL AREA BY THE TUESDAY-
WEDNESDAY TIME FRAME.
DIFFERENCES ARISE IN THE PATTERN AROUND WEDNESDAY WHEN THE
ECMWF...FOR THE SECOND RUN IN A ROW SHOWS A STRONG SHORTWAVE
MOVING OUT OF THE OHIO VALLEY. THE OPERATIONAL GFS AND THE GEFS
HAVE A TROF...BUT FLATTER AND MUCH MORE POSITIVELY TILTED. THE
ECMWF EVENTUALLY USES ITS POTENT WAVE TO DEVELOP A COASTAL LOW
THAT BRINGS AN EARLY SEASON NOR`EASTER TO NEW ENGLAND AND THE
MARITIMES...WHILE THE GFS/GEFS JUST KEEPS US IN GENERALLY COOL
AND CYCLONIC UPPER FLOW WHICH AT THIS TIME OF YEAR STARTS TO
MEAN PLENTY OF COLD ADVECTION STRATOCU AND LAKE/OROGRAPHIC
SHOWERS LOOKING LIKELY. THE MAIN DIFFERENCE LOCALLY GIVEN THE
MODEL DIFFERENCES WOULD BE FOR A BETTER CHANCE OF MORE
WIDESPREAD SHOWERS WEDNESDAY INTO WEDNESDAY NIGHT.
STARTING TUESDAY NIGHT...AND LASTING THROUGH THE WEEK...ALL
GUIDANCE AGREES THAT ENOUGH COLD AIR WILL HAVE MOVED INTO THE
REGION THAT ANY OF THE LIGHT SHOWERS THAT FALL COULD BE MIXED
WITH SNOW DURING THE CHILLIEST PART OF THE DAY AND OVERNIGHT.
ACCUMULATIONS WILL BE LIGHT IF ANY...BUT IT`S ALL POINTING TO
IT BEING DOWNHILL TO WINTER FROM HERE.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
HIGHER-END MVFR CIGS AND LOWER-END VFR CIGS EXPECTED THIS EVENING
AS THE COLD FRONT AND ASSOCD SHOWERS PUSH THROUGH FROM W-E.
SHOWERS OVER THE CENTRAL MTS WILL BE THE MAIN STORY AND COULD MAKE
GUSTS INTO THE L20S AT THE EASTERN TERMINALS AS THEY COAGULATE IN
THE NEXT HOUR OR SO. THE LIGHT RAIN TO THE WEST OF THE AREA WILL
LIKELY BEGIN TO DISSIPATE AS IT REACHES A BFD-JST LINE. THE DRY
AIR AT THE SFC WILL MAKE IT EASY FOR THE HUSTY WINDS BEHIND THE
FRONT TO MIX DOWN EARLY TONIGHT...BUT SOME DECOUPLING IS POSSIBLE
IN THE DEEPER VALLEYS IN THE MORNING. CLOUDS SHOULD DECREASE
RAPIDLY TONIGHT OVER THE SERN HALF OF THE FORECAST AREA. HIGH
PRESSURE BUILDS TO THE WEST FROM THE TN VALLEY...BUT STAYS FAR
ENOUGH AWAY TO KEEP SOME GRADIENT WIND - GENERALLY 10-12 KTS
DURING THE DAY ON SUNDAY WITH OTHERWISE VFR CONDITIONS. SHOWERS
MAY LINGER LATE TONIGHT AND VERY EARLY SUN A.M. VCTY BFD. BUT EVEN
AT BFD IMPROVEMENT TO VFR WILL OCCUR IN THE MORNING.
MONDAY LOOKS FAIR/VFR AS HIGH PRESSURE SLIDES TO THE EAST COAST
AND RETURN FLOW BEGINS. MORE COLD AIR ARRIVES WITH THE NEXT COLD
FRONT MON NIGHT AND TUESDAY.
OUTLOOK...
TUE...FROPA. MVFR/IFR POSS DUE TO SHOWERS/CLOUDS...ESP NW.
WED...MVFR POSS IN SHRA...ESP NW.
THURS...BREEZY...MVFR CLOUDS/SHRA N/W.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...LA CORTE
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1230 PM CDT SAT OCT 19 2013
.DISCUSSION...
18Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
VFR IN THIS POST-FRONTAL ENVIRONMENT. AREAWIDE SKY CLEAR BY
19-20Z AND WEAKENING NORTHERLIES TO VRB03KT/CALM SHORTLY AFTER
SUNSET. LIGHT BREEZE WAKES UP FROM THE EAST LATE SUNDAY MORNING
...A GRADUAL LATE SUNDAY AFTERNOON VEERING TO MORE ONSHORE WITH
A MID-LEVEL CLOUD DECK BY 00Z MONDAY. 31
&&
.PREV DISCUSSION... /ISSUED 1039 AM CDT SAT OCT 19 2013/
UPDATE...
SEE MORNING UPDATE.
DISCUSSION...
A COLD FRONT HAS CLEARED THE COAST AND SIGNIFICANTLY COOLER
TEMPERATURES AND DRIER AIR ARE FILTERING INTO SOUTHEAST TEXAS.
GRADIENT REMAINS RATHER TIGHT AND SO AM EXPECTING BREEZY CONDS TO
PERSIST. BETWEEN COLD AIR ADVECTION AND MIXING...AM NOT SURE THAT
THEY`LL BE MUCH OF A WARM UP TODAY DESPITE FULL SUNSHINE EXPECTED
THIS AFTN. TWEAKED MAX TEMPS A BIT LOWER OVER THE NORTH. TWEAKED
SKY GRIDS A BIT TO REFLECT RAPID CLEARING OVER THE NORTHERN ZONES.
THE CHANGES ARE VERY MINOR AND THE INTEGRITY OF THE PREVIOUS FCST
IS UNCHANGED AND ON TRACK. 43
&&
PREV DISCUSSION... /ISSUED 631 AM CDT SAT OCT 19 2013/
UPDATE...
EARLY MORNING UPDATE FOR RAIN MOVING OUT OF THE AREA.
DISCUSSION...
KEEPING UP WITH LATEST RADAR TRENDS HAVE UPDATED RAIN CHANCES FOR
THE DAY AS PRECIP CONTINUES TO MOVE EAST OUT INTO THE GULF. LOOKS
LIKE MOSTLY CLOUDY SKIES TO START THIS MORNING AS COLD FRONT
PUSHES THROUGH THE AREA. COLD FRONT CURRENTLY PUSHING THROUGH
CONROE AND APPROACHING THE HOUSTON AREA. FRONT SHOULD PUSH OFF THE
COAST MID MORNING. UPDATED FORECAST PRODUCTS HAVE BEEN ISSUED. 39
&&
PREV DISCUSSION... /ISSUED 608 AM CDT SAT OCT 19 2013/
DISCUSSION...
SEE AVIATION FOR 12Z TAF DISCUSSION
AVIATION...
SHRA HAVE MOVED OFFSHORE THIS MORNING AND ALL PRECIP MENTIONS WILL
BE REMOVED FROM THE TAFS. NORTHERLY WINDS ALREADY ONGOING AT ALL
SITES AS PREFRONTAL TROUGH HAS PUSHED OFFSHORE WITH THE ACTUAL
COLD FRONT HAVING REACHED CLL AND UTS THIS MORNING. EXPECT AN HOUR
OR TWO WITH GUSTS NEAR 20KTS AS THE FRONTAL BOUNDARY PUSHES
THROUGH THIS MORNING. MAIN CONCERN WILL BE SOUTHERLY EXTENT OF
IFR/MVFR CIGS IMMEDIATELY BEHIND THE FRONT. AS THE SUN COMES UP
THIS MORNING FEEL THAT THIS LAYER WILL BEGIN TO SCATTER OUT SO
HAVE NOT INCLUDED CIGS FOR IAH ALTHOUGH A BRIEF PERIOD OF
BKN010-BKN015 IS POSSIBLE THIS MORNING BEFORE CONDITIONS IMPROVE
TO VFR BY AFTERNOON. SURFACE HIGH PRESSURE WILL SPREAD INTO
SOUTHEAST TEXAS SATURDAY EVENING LEADING TO VARIABLE WINDS ACROSS
THE INLAND AREAS OVERNIGHT INTO SUNDAY. 38
&&
PREV DISCUSSION... /ISSUED 428 AM CDT SAT OCT 19 2013/
DISCUSSION...
COLD FRONT PUSHING SOUTH THROUGH TEXAS AT 09Z (4AM CDT) ABOUT AT
A KLFK/KUTS/K11R LINE OR BASICALLY A BRENHAM TO LUFKIN LINE. LINE
OF SHOWERS AND THUNDERSTORMS OVER HOUSTON EARLIER TONIGHT HAS
WEAKENED AND ACTIVITY HAS INCREASED MORE OFF THE UPPER TX COAST.
UPPER LEVEL SHORT WAVE LOOKS TO BE MOVING OUT OF THE AREA AND
POSSIBLE THAT UPPER LEVEL DIVERGENCE IS WEAKENING AS A RESULT.
BULK OF EARLIER CONVECTION HAS BEEN SUPPORTED BY SOME ISENTROPIC
LIFT AND FRONTOGENESIS IN 925-850MB LAYER PER SPC MESOANALYSES.
PER LATEST RADAR TRENDS...EXPECT SOME LINGERING SHOWERS ALONG THE
COAST BUT LOOKS LIKE MOST OF THE RAINFALL MAY BE DONE BY 12Z WHICH
IS A GOOD 3-6 HRS SOONER THAN MOST 00Z MODEL SOLUTIONS. HOWEVER
THE 00Z TX TECH 3KM WRF AND LATEST 06Z HRRR ARE IN GOOD AGREEMENT
WITH LATEST TRENDS. FORECAST HAS BE TRENDED TOWARDS THESE MODELS
IN THE SHORT TERM BUT MAY HOLD ONTO PRECIP A LITTLE LONGER. COLD
FRONT SHOULD BE OFF THE COAST BETWEEN 12-15Z THIS MORNING WITH
STRONG NORTHERLY WINDS ARE WIDE. UPPER LEVEL TROUGH AXIS WILL ALSO
HAVE PUSHED BY SE TX WITH RIGHT REAR QUADRANT OF JET STREAK STILL
LINGERING OVER THE AREA. HIGH PRESSURE AT THE SURFACE SHOULD
CONTINUE TO BUILD OVER TX TODAY. MAX TEMPS WILL BE A CHALLENGE AS
DO EXPECT SOME COLD ADVECTION TO OCCUR. HOWEVER 850MB TEMPS ONLY
DROP TO ABOUT 12-13C SO COULD STILL SEE TEMPS REACHING UPPER 60S
TO LOW 70S WITH DAYTIME HEATING. CLOUD COVER SHOULD CLEAR OUT SO
MAY NOT GET QUITE AS COOL AS IT COULD WITH BULK OF COLDER AIRMASS
MOVING EAST OF THE AREA OVER MISS RIVER VALLEY.
LOOKS LIKE RETURN FLOW AND WARM ADVECTION WILL ENSUE ONCE AGAIN
SUN NIGHT INTO MONDAY. VERY SIMILAR SET UP TO THE MOST RECENT RAIN
EVENT WITH WEAK ISENTROPIC LIFT AND A SHORT WAVE TROUGH ROTATING
THROUGH THE S PLAINS PROVIDING ENOUGH LARGE SCALE ASCENT FOR
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. THINK ORIENTATION OF
JET STREAK AND SHORT WAVE TROUGH MAY PUSH BULK OF PRECIP EAST OF
SE TX SO HAVE NOT CHANGED POPS MUCH. BEST CHANCES WILL AGAIN BE
ALONG THE COAST BUT WILL KEEP AROUND 50 PERCENT FOR NOW. ANOTHER
COLD FRONT WILL ALSO PUSH INTO SE TX BUT MORE SO MON NIGHT INTO
TUE MORNING. BEST LIFT WILL HAVE SHIFTED EAST BY THIS TIME SO WILL
BE HAVING DECREASING RAIN CHANCES MON NIGHT INTO TUE.
TUE THROUGH THE REST OF THE WEEK SHOULD BE DRY WITH A RATHER
AMPLIFIED UPPER LEVEL PATTERN. BROAD RIDGE SHOULD REMAIN OVER THE
PACIFIC COAST WITH A DEEP LOW AND LONG WAVE TROUGH OVER THE GREAT
LAKES AND MIDWEST. SEVERAL SHORT WAVE TROUGHS MOVING THROUGH THE
FLOW SHOULD KEEP THE TROUGH OVER THE GREAT LAKES THROUGH THE END
OF THE WEEK. WILL GET SFC HIGH PRESSURE BUILDING OVER TX THROUGH
WED WITH ANOTHER RIDGE BUILDING OVER THE MIDWEST THUR INTO FRI.
PATTERN SHOULD KEEP CONDITIONS DRY AND ON THE COOL SIDE. TRIED TO
BLEND THE TEMP FORECAST BETWEEN GFS AND ENSEMBLE MEAN TEMPS FOR
THE LATER HALF OF THE WEEK. THIS WILL MEAN TEMPS WILL BE NEAR OR
EVEN A DEGREE OR TWO BELOW NORMAL FOR THE END OF NEXT WEEK. 39
&&
MARINE...
NORTHERLY WINDS HAVE REACHED THE NEARSHORE BUOY THIS MORNING AS A
PREFRONTAL TROUGH PUSHES OUT AHEAD OF THE COLD FRONT MOVING INTO
SOUTHEAST TEXAS. EXPECT OFFSHORE WINDS TO PICK UP THROUGH THE
MORNING WITH BUILDING SEAS AS THE FRONT MOVES OFFSHORE. ADVISORY
FLAGS IN PLACE ACROSS ALL COASTAL WATERS TODAY AND MAY NEED TO BE
EXTENDED FURTHER STILL...ALTHOUGH WILL ALLOW NEXT SHIFT TO
EVALUATE NEW MODEL DATA AND OBSERVATIONS FROM TODAY BEFORE MAKING
THAT DECISION. EXPECT A QUICK RETURN OF ONSHORE WINDS LATE THIS
WEEKEND AHEAD OF YET ANOTHER FRONTAL PASSAGE EXPECTED LATE MONDAY
INTO TUESDAY. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 45 75 58 78 58 / 0 0 10 20 20
HOUSTON (IAH) 47 77 59 78 60 / 0 10 10 40 20
GALVESTON (GLS) 58 76 68 79 67 / 0 10 20 50 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 6 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...43
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1217 PM CDT SAT OCT 19 2013
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...DRIER AIR IS WORKING INTO THE AREA THIS AFTERNOON.
INTERMITTENT SCT TO BKN 2500 FT WILL GENERALLY BECOME MORE SCT TO
BKN AT 3500 FT THROUGH THE NEXT 3 OR 4 HOURS BEFORE BECOMING MORE
SCATTERED OVERALL. CLOUDS WILL HUG THE SIERRA MADRE KEEPING BKN TO
OVC AT AROUND 2000 FT LINGERING IN ZAPATA COUNTY...AND A BKN DECK
WILL STICK AROUND OVER THE GULF AND VERY CLOSE TO THE COAST FOR A
FEW MORE HOURS. WINDS WILL CONTINUE FROM NORTH TO NORTHEAST
GUSTING AT 20 TO 28KTS. THIS WILL GRADUALLY BEGIN DECREASING IN
THE MID TO LATE AFTERNOON BEFORE SLACKENING SIGNIFICANTLY AFTER SUNSET.
TONIGHT EXPECTING VFR CONDITIONS WITH SCT TO BKN MID CLOUD AND
FAIRLY LIGHT NORTHEAST WINDS. EXPECTING VFR CONDITIONS AT THE
START OF SUNDAY AS WELL WITH WINDS REMAINING LIGHT THROUGH THE
EARLY PART OF THE DAY. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 1108 AM CDT SAT OCT 19 2013/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...IMPROVED THE AVIATION OUTLOOK THROUGH THE NEXT SEVERAL
HOURS WITH CIGS IMPROVING TO MVFR ACROSS MOST OF THE AREA...WITH
THE VALLEY TAF SITES CIGS BETWEEN 2300 AND 2500 FT. AREAS CLOSE TO
THE COAST...ALONG THE NORTHEASTERLY TRAJECTORY OF THE WINDS MAY KEEP
ENOUGH MOISTURE FOR A 2500 TO 3000 FT CIG THROUGH THE AFTERNOON
BUT FURTHER INLAND A LIFTING TO AROUND 3500 FT AND GRADUAL
SCATTERING OF CLOUDS IS ANTICIPATED. TAFS ADJUSTED ACCORDINGLY.
PERIODIC MVFR WILL STILL BE POSSIBLE FOR THE NEXT 3 TO 5 HOURS AT
NON TAF SITES WITH A GRADUAL IMPROVEMENT TO GENERALLY VFR
CONDITIONS WITH CIGS AROUND 3500 FT. WINDS WILL CONTINUE TO GUST
AT AROUND 25 KNOTS AND OCCASIONALLY HIGHER. /68-JGG/
PREV DISCUSSION... /ISSUED 859 AM CDT SAT OCT 19 2013/
DISCUSSION...TWEAKED POPS DOWN TO SLIGHT CHANCE ALONG THE COAST
AND RIVER WITH THE FRONT A FEW HOURS AHEAD OF SCHEDULE. OBS FROM
SOUTH PADRE ISLAND ARE MEETING WIND ADVISORY CRITERIA...AND KBRO
VWP TRENDS SHOW STRONGER 1000-2000FT LEVEL WINDS AS THE DEEPER
COLD ADVECTION MOVES IN. BASED ON OBS AND RAP GUIDANCE EXPECT AT
OR NEAR ADVISORY LEVEL CONDITIONS ON SOUTH PADRE ISLAND AND RIGHT
NEAR THE LAGUNA MADRE THROUGH THE NEXT FEW HOURS SO ISSUED A WIND
ADVISORY UNTIL 2PM. THE FREQUENT GUST TRENDS AND EXPECTATIONS DO
NOT QUITE REQUIRE A GALE WARNING FOR THE LAGUNA/NEARSHORE WATERS
AT THIS TIME. /68-JGG/
PREV DISCUSSION... /ISSUED 749 AM CDT SAT OCT 19 2013/
DISCUSSION...12Z RAOB ANALYSIS AND SURFACE OBSERVATIONS SHOW MUCH
MORE EXTENSIVE 925/850MB COLD ADVECTION THAN WHAT WAS ORIGINALLY
ANTICIPATED WITH THIS COLD FRONT. BUOY OBSERVATIONS ARE PUSHING
GALE FORCE GUSTS IN THE LAST HOUR...AND BASED ON RAP AND OBSERVED
ANALYSIS STRONGER COLD ADVECTION/WIND IS EXPECTED THROUGH THE NEXT
FEW HOURS. WITH THAT UPGRADED THE OFFSHORE WATERS TO A GALE
WARNING THROUGH 4 PM THIS AFTERNOON FOR FREQUENT GALE FORCE GUSTS.
/68-JGG/
MARINE...HAVE UPGRADED THE SMALL CRAFT ADVISORY TO A GALE WARNING
FOR FREQUENT GALE FORCE GUSTS IN THE OFFSHORE ZONES.
PREV DISCUSSION... /ISSUED 651 AM CDT SAT OCT 19 2013/
DISCUSSION...UPDATED FOR LATEST MARINE DISCUSSION BELOW.
MARINE...HAVE MOVED UP THE STARTING TIME OF THE SCA WITH WINDS
BEHIND A LINE OF THUNDERSTORMS EXCEEDING SCA CRITERIA. DO NOT
BELIEVE THERE WILL BE MUCH OF LULL BEFORE HIGH PRESSURE BUILDS
TOWARDS THE COAST IN WAKE OF A COLD FRONT NOW MOVING ACROSS THE
NORTHERN RANCHLANDS. WINDS ACROSS THE LAGUNA MADRE WILL ALSO BE ON
THE INCREASE THIS EARLIER THIS MORNING.
PREV DISCUSSION... /ISSUED 628 AM CDT SAT OCT 19 2013/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...IFR CIGS SPREADING ACROSS THE REGION EARLY THIS
MORNING. EXPECT CIGS TO LOWER AT KHRL AND KBRO BY OR SHORTLY AFTER
SUNRISE. THE LOWER CIGS TO PERSIST THROUGH THE MORNING WITH A SLOW
RISE TO MVFR THIS AFTERNOON. VFR CONDITIONS NOT EXPECTED AT THE
REGIONAL AIRPORTS UNTIL THE EVENING HOURS. HIGH PRESSURE BUILDS
SOUTH INCREASING THE NORTH WIND. GUSTS TO 25 KNOTS ARE POSSIBLE
WITH A STEADY 12-18 KNOT WIND THROUGH THE DAY.
PREV DISCUSSION... /ISSUED 426 AM CDT SAT OCT 19 2013/
SHORT TERM /NOW THROUGH SUNDAY/...
SURFACE OBSERVATIONS INDICATE TWO FRONTS ACROSS SOUTH TEXAS THIS
MORNING. THE LEAD STATIONARY FRONT PARALLELS THE COAST WITH A WEAK
SURFACE LOW OR FRONTAL WAVE EAST OF KENEDY COUNTY. THE SECOND FRONT
EXTENDS FROM NEAR SHREVEPORT TO COTULLA.
MAIN CHALLENGE FOR TODAY IS THE POP FORECAST FOLLOWED BY THE
TEMPERATURES. MOST CONVECTION CURRENTLY HAS BEEN DEVELOPING ALONG
THE COASTAL TROUGH AND NORTHEAST OF SURFACE LOW. MOST OF SOUTH TEXAS
REMAINS UNDER LARGE SCALE ASCENT WITH THE REGION UNDER THE RIGHT
REAR QUADRANT OF 100+ KNOT JET. HOWEVER BEST SURFACE CONVERGENCE IS
NOTED ALONG THE LEAD BOUNDARY AND SURFACE LOW. ANOTHER WEAK
DISTURBANCE IS APPROACHING THE COASTAL AREAS OF TAMAULIPAS WHICH
LOOKS TO PASS TO OUR SOUTH. GUT FEELING FROM CURRENT TRENDS IS FOR
THE MAJORITY OF THE CONVECTION TO REMAIN OFFSHORE WITH SOME ISOLATED
TO POSSIBLE SCATTERED ACTIVITY DEVELOPING OVER THE COASTAL COUNTIES
BEFORE SUNRISE. AS THE SECOND FRONT MOVES INTO THE AREA THE BEST
MOISTURE WILL BE SHOVED EAST WITH LITTLE LEFT TO PRODUCE AS MUCH
RAIN AS WHAT IS CURRENTLY PROJECTED IN THE FORECAST. HAVE ALREADY
LOWERED RAIN CHANCES BUT HAVE REDUCE THE MENTION OF THUNDER EXCEPT
OVER KENEDY COUNTY AND THE GULF WATERS. TIMING OF THE SECOND FRONT
IN LINE WITH THE NAM MODEL WHICH IS ABOUT 3 HOURS SLOWER THEN THE
GFS. THE FRONT TO MOVE THROUGH THE NORTHERN ZONES AROUND OR SHORTLY
AFTER SUNRISE WORKING ITS WAY SOUTH OF BROWNSVILLE BY 10 AM. WE CAN
EXPECT OUR WINDS TO TURN NORTH TO NORTHWEST AHEAD OF THE SECOND
FRONT WITH A MORE NOTICEABLE AIRMASS CHANGE WITH STRONGER WIND AND
COOLING TEMPERATURES AS THE SECOND BOUNDARY PASSES THROUGH THE
REGION. CURRENT OBSERVATIONS INDICATE A NICE COOL AIRMASS OVER
NORTH CENTRAL TEXAS AND SOME OF THAT AIR TO SPREAD SOUTH AS NORTH
WINDS INCREASE TO BREEZY LEVELS. EXPECT HIGH TEMPERATURES TO OCCUR
THIS MORNING WITH A SLOW STEADY FALL THROUGH THE AFTERNOON. ANY RAIN
THAT FALLS BEHIND THE FRONT WILL PROVIDE AN EVAPORATIVE COOLING
AFFECT WHICH WILL ALLOW FOR TEMPERATURES TO FALL MORE QUICKLY ALBEIT
FOR A SHORT WHILE. IN ANY CASE HAVE LOWERED TEMPERATURES A FEW
DEGREES AND IT WILL FEEL A BIT CHILLY WITH A GRAY OVERCAST HOLDING
TOUGH ALL DAY.
TONIGHT...COOL SURFACE HIGH BUILDS MORE OVER EAST TEXAS THEN OVER
OUR REGION WITH NORTH WINDS VEERING NORTHEAST AND DIMINISHING
RAPIDLY. THE COLD AIR ADVECTION DURING THE DAYTIME HOURS WILL BE
WEAKENING. GUIDANCE TEMPERATURES HAVE LOWERED A FEW DEGREES OVER
PREVIOUS RUNS AND WITH EVIDENCE OF TEMPERATURES UPSTREAM WILL TREND
IN THIS DIRECTION EVEN WITH AN OVERCAST CONDITIONS. DO NOT EXPECT
THE CLOUDS TO CLEAR AS 700MB FLOW TURNS SOUTHWEST DEVELOPING WEAK
OVERRUNNING.
SUNDAY...HIGH PRESSURE MOVES WELL EAST AND UPPER FLOW REMAINS
WESTERLY WHICH WILL ALLOW FOR OUR AIRMASS TO BEGIN MODIFYING RATHER
QUICKLY. FRONT STALLS WELL SOUTH AND THE EXPECTED DEVELOPMENT OF A
COASTAL TROUGH MIGHT BE DELAYED BY 6 HOURS. THIS WILL KEEP OUR RAIN
CHANCES LOWER AND LIKELY OUT OVER THE GULF. A SHORTWAVE TROUGH IN
THE WESTERLY FLOW EVENTUALLY WORKS ITS WAY NEAR THE BIG BEND AREA
WITH THE SURFACE INFLECTION DEVELOPING LATER IN THE DAY OR IN THE
EVENING WITH RAIN CHANCES POSSIBLY INCREASE AFTER DARK. WINDS TO
VEER EAST AND TEMPERATURES TO WARM UP WITH SOME BREAKS IN THE
OVERCAST ESPECIALLY ACROSS THE NORTH AND WEST. /59/
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
BROAD UPPER-LEVEL TROUGHINESS WILL CONTINUE TO DOMINATE MUCH OF THE
CENTRAL AND EASTERN UNITED STATES AS WE HEAD INTO THE LONG TERM
PORTION OF THE FORECAST. CLOSER TO HOME...IT LOOKS LIKE SHOWER
POSSIBILITIES WILL CONTINUE AS WE HEAD TOWARD THE START OF THE NEW
WORKWEEK AS A COASTAL TROUGH REMAINS IN PLACE.
LOW-LEVEL THETA-E VALUES WILL LIKELY APPROACH 340K DURING THIS
PERIOD...WITH PRECIPITABLE WATER VALUES RANGING FROM 1.8 INCHES NEAR
THE US-281 CORRIDOR TO A LITTLE MORE THAN 2 INCHES ALONG THE COAST
AND OFFSHORE. THESE PRECIPITABLE WATER VALUES ARE ABOVE THE 75TH
PERCENTILE CLIMATOLOGICALLY. IN OTHER WORDS...PLENTY OF MOISTURE
SHOULD BE SEEN THROUGH THE BOUNDARY LAYER SUNDAY NIGHT AND MONDAY.
COMBINED WITH THE PRESENCE OF THE COASTAL TROUGH...AT LEAST A
SCATTERING OF SHOWERS WILL LIKELY BE SEEN.
I HAVE A CONCERN OR TWO ABOUT THIS SCENARIO THOUGH. MOST OF THE
ISENTROPIC ASCENT AND LOWER CONDENSATION PRESSURE DEFICITS /ALONG
THE 310K THETA SURFACE/ SHIFT OFFSHORE SUNDAY EVENING...WITH
ADDITIONAL MOISTURE MOVING INTO THIS REGION OVERNIGHT. THE UPGLIDE
THEN STRENGTHENS AND STARTS TO MOVE NORTHEAST /AND AWAY FROM OUR
AREA/ MONDAY MORNING. EVIDENCE OF THIS ALSO EXISTS IN THE QG
FIELDS...AS A MID-LEVEL SHORTWAVE TROUGH MOVES NORTHEAST THROUGH THE
REGION.
THIS IMPLIES TO ME TWO THINGS. FIRST...THE BEST TIME TO SEE
PRECIPITATION FOR OUR REGION WILL LIKELY BE LATE SUNDAY NIGHT...
WITH DIMINISHING ODDS MONDAY MORNING. THIS IS A TAD FASTER THAN
WHAT THE CURRENT FORECAST IMPLIES. SECOND...THE ODDS OF SEEING
SHOWERS /MAINLY OVER LAND AREAS/ MAY NOT BE AS GREAT AS THE CURRENT
FORECAST. WITH THIS FORECAST PACKAGE...I HAVE MADE SOME TWEAKS TO
TIMING BASED ON THE LATEST DATA. PRECIPITATION PROBABILITIES HAVE
LARGELY REMAINED UNTOUCHED...AND WILL ALLOW SUBSEQUENT SHIFTS TO
FINE TUNE THE FORECAST USING THE LATEST AVAILABLE DATA.
CONDITIONS SHOULD START TO DRY OUT A BIT MONDAY AFTERNOON AND
EVENING...AS THE SURFACE TROUGH MOVES FARTHER OFFSHORE. A SHORTWAVE
TROUGH IS EXPECTED TO SWING THROUGH THE SOUTHERN PLAINS MONDAY NIGHT
INTO TUESDAY MORNING. THERE MAY BE ENOUGH MOMENTUM ASSOCIATED WITH
THIS FEATURE TO PUSH A WEAK COLD FRONT THROUGH THE AREA TUESDAY
MORNING. SOME LOW CLOUDS MAY REMAIN IN PLACE BEHIND THE FRONT
THANKS TO A BIT OF LINGERING THERMAL TROUGHINESS AT 850MB.
THE UPPER TROUGH AXIS IS FORECAST TO SHIFT EAST WEDNESDAY.
NORTHWEST FLOW ALOFT OVER OUR AREA IN WAKE OF THIS SYSTEM SHOULD
ALLOW THE CENTER OF A SURFACE HIGH TO HEAD INTO THE OZARKS
WEDNESDAY. WEAK SHORTWAVE RIDGING...COMBINED WITH A SURFACE HIGH
NEAR THE ARKLAMISS SHOULD ALLOW QUIET WEATHER CONDITIONS TO BE SEEN
FOR THE REMAINDER OF THE UPCOMING WORKWEEK. /BUTTS/
MARINE...
TODAY THROUGH SUNDAY...
SMALL CRAFT ADVISORIES ARE IN PLACE FOR ALL COASTAL WATERS TODAY AS
NORTH WINDS TO INCREASE BEHIND A COLD FRONT POISED TO MOVE OFFSHORE
AFTER SUNRISE. SEAS TO RESPOND RATHER QUICKLY WITH ROUGH CONDITIONS
BY OR BEFORE NOON. HIGH PRESSURE TO BUILDS NORTH AND EAST OF THE
LOWER TEXAS COAST TONIGHT INTO SUNDAY WITH WINDS AND SEAS LOWERING.
SCA COULD PERSIST FOR THE OFFSHORE WATERS THIS EVENING BUT SHOULD
FALL BELOW CRITERIA BY MIDNIGHT. MORNING SHOWERS AND THUNDERSTORMS
TO FAVOR THE NORTHERN WATERS WITH AREAS OF RAIN WITH EMBEDDED
SHOWERS ACROSS THE SOUTH. MOST OF THE STORMS TO PUSH OFF TO THE
NORTHEAST BEFORE NOON. /59/
SUNDAY NIGHT THROUGH WEDNESDAY...
A TROUGH OF LOW PRESSURE JUST OFFSHORE...COMBINED WITH AMPLE
MOISTURE...SHOULD ALLOW SHOWERS AND A FEW STORMS TO BE SEEN OVER THE
MARINE AREA SUNDAY NIGHT THROUGH MONDAY. E WINDS /GENERALLY 10 KTS
OR LESS/ SHOULD BECOME SE SUNDAY NIGHT...THEN BECOME SW-W MONDAY
AFTERNOON AS THE TROUGH MOVES FARTHER OFFSHORE. A WEAK COLD FRONT
IS FORECAST TO MOVE THROUGH THE MARINE AREA TUESDAY. THIS IS
EXPECTED TO RESULT IN STRENGTHENING N-NE WINDS AND BUILDING SEAS.
SMALL CRAFT ADVISORIES MAY BE NEEDED FOR ALL OR PART OF THE MARINE
AREA DURING THIS TIME. /BUTTS/
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 2 PM CDT THIS AFTERNOON FOR TXZ256-257.
GM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR GMZ130-132-
135.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 1 AM CDT SUNDAY
FOR GMZ170-175.
GALE WARNING UNTIL 4 PM CDT THIS AFTERNOON FOR GMZ170-175.
SMALL CRAFT ADVISORY UNTIL 1 AM CDT SUNDAY FOR GMZ150-155.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/61
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1108 AM CDT SAT OCT 19 2013
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...IMPROVED THE AVIATION OUTLOOK THROUGH THE NEXT SEVERAL
HOURS WITH CIGS IMPROVING TO MVFR ACROSS MOST OF THE AREA...WITH
THE VALLEY TAF SITES CIGS BETWEEN 2300 AND 2500 FT. AREAS CLOSE TO
THE COAST...ALONG THE NORTHEASTERLY TRAJECTORY OF THE WINDS MAY KEEP
ENOUGH MOISTURE FOR A 2500 TO 3000 FT CIG THROUGH THE AFTERNOON
BUT FURTHER INLAND A LIFTING TO AROUND 3500 FT AND GRADUAL
SCATTERING OF CLOUDS IS ANTICIPATED. TAFS ADJUSTED ACCORDINGLY.
PERIODIC MVFR WILL STILL BE POSSIBLE FOR THE NEXT 3 TO 5 HOURS AT
NON TAF SITES WITH A GRADUAL IMPROVEMENT TO GENERALLY VFR
CONDITIONS WITH CIGS AROUND 3500 FT. WINDS WILL CONTINUE TO GUST
AT AROUND 25 KNOTS AND OCCASIONALLY HIGHER. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 859 AM CDT SAT OCT 19 2013/
DISCUSSION...TWEAKED POPS DOWN TO SLIGHT CHANCE ALONG THE COAST
AND RIVER WITH THE FRONT A FEW HOURS AHEAD OF SCHEDULE. OBS FROM
SOUTH PADRE ISLAND ARE MEETING WIND ADVISORY CRITERIA...AND KBRO
VWP TRENDS SHOW STRONGER 1000-2000FT LEVEL WINDS AS THE DEEPER
COLD ADVECTION MOVES IN. BASED ON OBS AND RAP GUIDANCE EXPECT AT
OR NEAR ADVISORY LEVEL CONDITIONS ON SOUTH PADRE ISLAND AND RIGHT
NEAR THE LAGUNA MADRE THROUGH THE NEXT FEW HOURS SO ISSUED A WIND
ADVISORY UNTIL 2PM. THE FREQUENT GUST TRENDS AND EXPECTATIONS DO
NOT QUITE REQUIRE A GALE WARNING FOR THE LAGUNA/NEARSHORE WATERS
AT THIS TIME. /68-JGG/
PREV DISCUSSION... /ISSUED 749 AM CDT SAT OCT 19 2013/
DISCUSSION...12Z RAOB ANALYSIS AND SURFACE OBSERVATIONS SHOW MUCH
MORE EXTENSIVE 925/850MB COLD ADVECTION THAN WHAT WAS ORIGINALLY
ANTICIPATED WITH THIS COLD FRONT. BUOY OBSERVATIONS ARE PUSHING
GALE FORCE GUSTS IN THE LAST HOUR...AND BASED ON RAP AND OBSERVED
ANALYSIS STRONGER COLD ADVECTION/WIND IS EXPECTED THROUGH THE NEXT
FEW HOURS. WITH THAT UPGRADED THE OFFSHORE WATERS TO A GALE
WARNING THROUGH 4 PM THIS AFTERNOON FOR FREQUENT GALE FORCE GUSTS.
/68-JGG/
MARINE...HAVE UPGRADED THE SMALL CRAFT ADVISORY TO A GALE WARNING
FOR FREQUENT GALE FORCE GUSTS IN THE OFFSHORE ZONES.
PREV DISCUSSION... /ISSUED 651 AM CDT SAT OCT 19 2013/
DISCUSSION...UPDATED FOR LATEST MARINE DISCUSSION BELOW.
MARINE...HAVE MOVED UP THE STARTING TIME OF THE SCA WITH WINDS
BEHIND A LINE OF THUNDERSTORMS EXCEEDING SCA CRITERIA. DO NOT
BELIEVE THERE WILL BE MUCH OF LULL BEFORE HIGH PRESSURE BUILDS
TOWARDS THE COAST IN WAKE OF A COLD FRONT NOW MOVING ACROSS THE
NORTHERN RANCHLANDS. WINDS ACROSS THE LAGUNA MADRE WILL ALSO BE ON
THE INCREASE THIS EARLIER THIS MORNING.
PREV DISCUSSION... /ISSUED 628 AM CDT SAT OCT 19 2013/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...IFR CIGS SPREADING ACROSS THE REGION EARLY THIS
MORNING. EXPECT CIGS TO LOWER AT KHRL AND KBRO BY OR SHORTLY AFTER
SUNRISE. THE LOWER CIGS TO PERSIST THROUGH THE MORNING WITH A SLOW
RISE TO MVFR THIS AFTERNOON. VFR CONDITIONS NOT EXPECTED AT THE
REGIONAL AIRPORTS UNTIL THE EVENING HOURS. HIGH PRESSURE BUILDS
SOUTH INCREASING THE NORTH WIND. GUSTS TO 25 KNOTS ARE POSSIBLE
WITH A STEADY 12-18 KNOT WIND THROUGH THE DAY.
PREV DISCUSSION... /ISSUED 426 AM CDT SAT OCT 19 2013/
SHORT TERM /NOW THROUGH SUNDAY/...
SURFACE OBSERVATIONS INDICATE TWO FRONTS ACROSS SOUTH TEXAS THIS
MORNING. THE LEAD STATIONARY FRONT PARALLELS THE COAST WITH A WEAK
SURFACE LOW OR FRONTAL WAVE EAST OF KENEDY COUNTY. THE SECOND FRONT
EXTENDS FROM NEAR SHREVEPORT TO COTULLA.
MAIN CHALLENGE FOR TODAY IS THE POP FORECAST FOLLOWED BY THE
TEMPERATURES. MOST CONVECTION CURRENTLY HAS BEEN DEVELOPING ALONG
THE COASTAL TROUGH AND NORTHEAST OF SURFACE LOW. MOST OF SOUTH TEXAS
REMAINS UNDER LARGE SCALE ASCENT WITH THE REGION UNDER THE RIGHT
REAR QUADRANT OF 100+ KNOT JET. HOWEVER BEST SURFACE CONVERGENCE IS
NOTED ALONG THE LEAD BOUNDARY AND SURFACE LOW. ANOTHER WEAK
DISTURBANCE IS APPROACHING THE COASTAL AREAS OF TAMAULIPAS WHICH
LOOKS TO PASS TO OUR SOUTH. GUT FEELING FROM CURRENT TRENDS IS FOR
THE MAJORITY OF THE CONVECTION TO REMAIN OFFSHORE WITH SOME ISOLATED
TO POSSIBLE SCATTERED ACTIVITY DEVELOPING OVER THE COASTAL COUNTIES
BEFORE SUNRISE. AS THE SECOND FRONT MOVES INTO THE AREA THE BEST
MOISTURE WILL BE SHOVED EAST WITH LITTLE LEFT TO PRODUCE AS MUCH
RAIN AS WHAT IS CURRENTLY PROJECTED IN THE FORECAST. HAVE ALREADY
LOWERED RAIN CHANCES BUT HAVE REDUCE THE MENTION OF THUNDER EXCEPT
OVER KENEDY COUNTY AND THE GULF WATERS. TIMING OF THE SECOND FRONT
IN LINE WITH THE NAM MODEL WHICH IS ABOUT 3 HOURS SLOWER THEN THE
GFS. THE FRONT TO MOVE THROUGH THE NORTHERN ZONES AROUND OR SHORTLY
AFTER SUNRISE WORKING ITS WAY SOUTH OF BROWNSVILLE BY 10 AM. WE CAN
EXPECT OUR WINDS TO TURN NORTH TO NORTHWEST AHEAD OF THE SECOND
FRONT WITH A MORE NOTICEABLE AIRMASS CHANGE WITH STRONGER WIND AND
COOLING TEMPERATURES AS THE SECOND BOUNDARY PASSES THROUGH THE
REGION. CURRENT OBSERVATIONS INDICATE A NICE COOL AIRMASS OVER
NORTH CENTRAL TEXAS AND SOME OF THAT AIR TO SPREAD SOUTH AS NORTH
WINDS INCREASE TO BREEZY LEVELS. EXPECT HIGH TEMPERATURES TO OCCUR
THIS MORNING WITH A SLOW STEADY FALL THROUGH THE AFTERNOON. ANY RAIN
THAT FALLS BEHIND THE FRONT WILL PROVIDE AN EVAPORATIVE COOLING
AFFECT WHICH WILL ALLOW FOR TEMPERATURES TO FALL MORE QUICKLY ALBEIT
FOR A SHORT WHILE. IN ANY CASE HAVE LOWERED TEMPERATURES A FEW
DEGREES AND IT WILL FEEL A BIT CHILLY WITH A GRAY OVERCAST HOLDING
TOUGH ALL DAY.
TONIGHT...COOL SURFACE HIGH BUILDS MORE OVER EAST TEXAS THEN OVER
OUR REGION WITH NORTH WINDS VEERING NORTHEAST AND DIMINISHING
RAPIDLY. THE COLD AIR ADVECTION DURING THE DAYTIME HOURS WILL BE
WEAKENING. GUIDANCE TEMPERATURES HAVE LOWERED A FEW DEGREES OVER
PREVIOUS RUNS AND WITH EVIDENCE OF TEMPERATURES UPSTREAM WILL TREND
IN THIS DIRECTION EVEN WITH AN OVERCAST CONDITIONS. DO NOT EXPECT
THE CLOUDS TO CLEAR AS 700MB FLOW TURNS SOUTHWEST DEVELOPING WEAK
OVERRUNNING.
SUNDAY...HIGH PRESSURE MOVES WELL EAST AND UPPER FLOW REMAINS
WESTERLY WHICH WILL ALLOW FOR OUR AIRMASS TO BEGIN MODIFYING RATHER
QUICKLY. FRONT STALLS WELL SOUTH AND THE EXPECTED DEVELOPMENT OF A
COASTAL TROUGH MIGHT BE DELAYED BY 6 HOURS. THIS WILL KEEP OUR RAIN
CHANCES LOWER AND LIKELY OUT OVER THE GULF. A SHORTWAVE TROUGH IN
THE WESTERLY FLOW EVENTUALLY WORKS ITS WAY NEAR THE BIG BEND AREA
WITH THE SURFACE INFLECTION DEVELOPING LATER IN THE DAY OR IN THE
EVENING WITH RAIN CHANCES POSSIBLY INCREASE AFTER DARK. WINDS TO
VEER EAST AND TEMPERATURES TO WARM UP WITH SOME BREAKS IN THE
OVERCAST ESPECIALLY ACROSS THE NORTH AND WEST. /59/
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
BROAD UPPER-LEVEL TROUGHINESS WILL CONTINUE TO DOMINATE MUCH OF THE
CENTRAL AND EASTERN UNITED STATES AS WE HEAD INTO THE LONG TERM
PORTION OF THE FORECAST. CLOSER TO HOME...IT LOOKS LIKE SHOWER
POSSIBILITIES WILL CONTINUE AS WE HEAD TOWARD THE START OF THE NEW
WORKWEEK AS A COASTAL TROUGH REMAINS IN PLACE.
LOW-LEVEL THETA-E VALUES WILL LIKELY APPROACH 340K DURING THIS
PERIOD...WITH PRECIPITABLE WATER VALUES RANGING FROM 1.8 INCHES NEAR
THE US-281 CORRIDOR TO A LITTLE MORE THAN 2 INCHES ALONG THE COAST
AND OFFSHORE. THESE PRECIPITABLE WATER VALUES ARE ABOVE THE 75TH
PERCENTILE CLIMATOLOGICALLY. IN OTHER WORDS...PLENTY OF MOISTURE
SHOULD BE SEEN THROUGH THE BOUNDARY LAYER SUNDAY NIGHT AND MONDAY.
COMBINED WITH THE PRESENCE OF THE COASTAL TROUGH...AT LEAST A
SCATTERING OF SHOWERS WILL LIKELY BE SEEN.
I HAVE A CONCERN OR TWO ABOUT THIS SCENARIO THOUGH. MOST OF THE
ISENTROPIC ASCENT AND LOWER CONDENSATION PRESSURE DEFICITS /ALONG
THE 310K THETA SURFACE/ SHIFT OFFSHORE SUNDAY EVENING...WITH
ADDITIONAL MOISTURE MOVING INTO THIS REGION OVERNIGHT. THE UPGLIDE
THEN STRENGTHENS AND STARTS TO MOVE NORTHEAST /AND AWAY FROM OUR
AREA/ MONDAY MORNING. EVIDENCE OF THIS ALSO EXISTS IN THE QG
FIELDS...AS A MID-LEVEL SHORTWAVE TROUGH MOVES NORTHEAST THROUGH THE
REGION.
THIS IMPLIES TO ME TWO THINGS. FIRST...THE BEST TIME TO SEE
PRECIPITATION FOR OUR REGION WILL LIKELY BE LATE SUNDAY NIGHT...
WITH DIMINISHING ODDS MONDAY MORNING. THIS IS A TAD FASTER THAN
WHAT THE CURRENT FORECAST IMPLIES. SECOND...THE ODDS OF SEEING
SHOWERS /MAINLY OVER LAND AREAS/ MAY NOT BE AS GREAT AS THE CURRENT
FORECAST. WITH THIS FORECAST PACKAGE...I HAVE MADE SOME TWEAKS TO
TIMING BASED ON THE LATEST DATA. PRECIPITATION PROBABILITIES HAVE
LARGELY REMAINED UNTOUCHED...AND WILL ALLOW SUBSEQUENT SHIFTS TO
FINE TUNE THE FORECAST USING THE LATEST AVAILABLE DATA.
CONDITIONS SHOULD START TO DRY OUT A BIT MONDAY AFTERNOON AND
EVENING...AS THE SURFACE TROUGH MOVES FARTHER OFFSHORE. A SHORTWAVE
TROUGH IS EXPECTED TO SWING THROUGH THE SOUTHERN PLAINS MONDAY NIGHT
INTO TUESDAY MORNING. THERE MAY BE ENOUGH MOMENTUM ASSOCIATED WITH
THIS FEATURE TO PUSH A WEAK COLD FRONT THROUGH THE AREA TUESDAY
MORNING. SOME LOW CLOUDS MAY REMAIN IN PLACE BEHIND THE FRONT
THANKS TO A BIT OF LINGERING THERMAL TROUGHINESS AT 850MB.
THE UPPER TROUGH AXIS IS FORECAST TO SHIFT EAST WEDNESDAY.
NORTHWEST FLOW ALOFT OVER OUR AREA IN WAKE OF THIS SYSTEM SHOULD
ALLOW THE CENTER OF A SURFACE HIGH TO HEAD INTO THE OZARKS
WEDNESDAY. WEAK SHORTWAVE RIDGING...COMBINED WITH A SURFACE HIGH
NEAR THE ARKLAMISS SHOULD ALLOW QUIET WEATHER CONDITIONS TO BE SEEN
FOR THE REMAINDER OF THE UPCOMING WORKWEEK. /BUTTS/
MARINE...
TODAY THROUGH SUNDAY...
SMALL CRAFT ADVISORIES ARE IN PLACE FOR ALL COASTAL WATERS TODAY AS
NORTH WINDS TO INCREASE BEHIND A COLD FRONT POISED TO MOVE OFFSHORE
AFTER SUNRISE. SEAS TO RESPOND RATHER QUICKLY WITH ROUGH CONDITIONS
BY OR BEFORE NOON. HIGH PRESSURE TO BUILDS NORTH AND EAST OF THE
LOWER TEXAS COAST TONIGHT INTO SUNDAY WITH WINDS AND SEAS LOWERING.
SCA COULD PERSIST FOR THE OFFSHORE WATERS THIS EVENING BUT SHOULD
FALL BELOW CRITERIA BY MIDNIGHT. MORNING SHOWERS AND THUNDERSTORMS
TO FAVOR THE NORTHERN WATERS WITH AREAS OF RAIN WITH EMBEDDED
SHOWERS ACROSS THE SOUTH. MOST OF THE STORMS TO PUSH OFF TO THE
NORTHEAST BEFORE NOON. /59/
SUNDAY NIGHT THROUGH WEDNESDAY...
A TROUGH OF LOW PRESSURE JUST OFFSHORE...COMBINED WITH AMPLE
MOISTURE...SHOULD ALLOW SHOWERS AND A FEW STORMS TO BE SEEN OVER THE
MARINE AREA SUNDAY NIGHT THROUGH MONDAY. E WINDS /GENERALLY 10 KTS
OR LESS/ SHOULD BECOME SE SUNDAY NIGHT...THEN BECOME SW-W MONDAY
AFTERNOON AS THE TROUGH MOVES FARTHER OFFSHORE. A WEAK COLD FRONT
IS FORECAST TO MOVE THROUGH THE MARINE AREA TUESDAY. THIS IS
EXPECTED TO RESULT IN STRENGTHENING N-NE WINDS AND BUILDING SEAS.
SMALL CRAFT ADVISORIES MAY BE NEEDED FOR ALL OR PART OF THE MARINE
AREA DURING THIS TIME. /BUTTS/
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 2 PM CDT THIS AFTERNOON FOR TXZ256-257.
GM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR GMZ130-132-
135.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 1 AM CDT SUNDAY
FOR GMZ170-175.
GALE WARNING UNTIL 4 PM CDT THIS AFTERNOON FOR GMZ170-175.
SMALL CRAFT ADVISORY UNTIL 1 AM CDT SUNDAY FOR GMZ150-155.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/61