Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/25/13
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
823 PM MDT FRI MAY 24 2013
.UPDATE...
&&
.SHORT TERM...TSTMS HAVE ENDED OVER THE FAR NERN PLAINS. A BNDRY
HAS WORKED ITS WAY BACK INTO THE FRONT RANGE BUT NO TSTMS HAVE
DEVELOPED ALONG IT AS IT APPEARS AIRMASS IS CAPPED. STILL COULD
SEE AN ISOLD STORM OR TWO OVER THE FAR NERN CORNER THRU MIDNIGHT
SO WILL LEAVE IN LOW POPS OUT THERE.
.AVIATION...DEEPER LOW LVL MOISTURE HAS SURGED BACK INTO THE
AIRPORT. LATEST RAP SHOWS SOME POTENTIAL FOR STRATUS TO DVLP OVER
SRN WELD COUNTY BY 10Z HOWEVER LOW LVL WINDS ARE FCST TO BECOME
MORE SWLY BY THEN SO FOR NOW WILL KEEP STRATUS TO THE N AND NE OF
DIA FOR LATER TONIGHT. AS FOR WINDS WILL KEEP THEN NELY THRU 05Z
AND THEN GRADUALLY SHIFT THEM BACK TO SSW AFTER 06Z.
&&
.HYDROLOGY...NO ISSUES
&&
.PREV DISCUSSION... /ISSUED 249 PM MDT FRI MAY 24 2013/
SHORT TERM...CURRENT DEW POINT READINGS HAVE FALLEN INTO THE 20S-
30S F OVER THE SOUTHERN HALF OF THE PLAINS...AND INTO THE TEENS F
IN THE MOUNTAINS AND FOOTHILLS. OVER THE REST OF THE PLAINS THEY
ARE IN THE 40S-50S F...HIGHEST OVER THE NORTHEAST CORNER.
SATELLITE PICTURES ARE SHOWING VERY LITTLE CONVECTIVE CLOUDINESS
AT THIS TIME. THERE IS QUITE A BIT OF CIN OVER THE PLAINS RIGHT
NOW. THERE IS A DENVER CYCLONE CENTERED NEAR DENVER INTERNATIONAL
AIRPORT ALONG WITH A BOUNDARY STRETCHING FROM AROUND MORRISON IN
JEFFERSON COUNTY TO CENTRAL ADAMS COUNTY. MODELS KEEP
SOUTHWESTERLY FLOW ALOFT FOR THE CWA TONIGHT AND SATURDAY. THE
SYNOPTIC SCALE ENERGY IS PROGGED TO BE BENIGN TONIGHT AND
SATURDAY. BOUNDARY LAYER FLOW IS PROGGED TO BE NORMAL DRAINAGE
TONIGHT AND MAINLY SOUTHWESTERLY DOWNSLOPING ON SATURDAY. SOME OF
THE MODELS HANG ON TO EASTERLY FLOW OVER THE NORTHEAST CORNER ON
SATURDAY. MOISTURE IS NOT GOOD...WITH THE EXCEPTION OF THE LOWER
LEVELS OVER THE EASTERN PLAINS. DEW POINTS ARE PROGGED TO STAY
ABOVE 50S F OVER THE NORTHEAST CORNER THIS EVENING...AND AGAIN
SATURDAY AFTERNOON. PROGGED CAPES ARE FAIRLY DECENT OVER THE
EASTERN PLAINS...OVER 2000 J/KG THIS EVENING. FOR POPS THIS
EVENING...WILL STAY THE COURSE AND KEEP 10-30%S OVER THE NORTHEAST
CORNER THROUGH MID TO LATE EVENING. THE SHEAR IS GOOD AND THE
MOISTURE PLENTIFUL. NO POPS ELSEWHERE. FOR SATURDAY...THE DECENT
CAPE IS PROGGED OVER THE NORTHEAST CORNER AGAIN. THE SHEAR IS NOT
AS GOOD TO NO SEVERE MENTIONED THERE BUT WILL GO WITH 10-20%S FOR
LATER AFTERNOON. SATURDAY`S HIGHS LOOK TO BE 0-1.5 C WARMER THAN
TODAY`S CURRENT HIGHS.
LONG TERM...SOUTHWEST FLOW ALOFT WILL CONTINUE THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK AS UPPER LEVEL TROUGHING STAYS
OVER THE PACIFIC NORTHWEST AND RIDGING REMAINS OVER THE CENTRAL
US. THROUGH TUESDAY...NOT MUCH MOISTURE WILL BE ENTRAINED IN THIS
SOUTHWEST FLOW...SO EXPECTING DRIER AND WARMER CONDITIONS THAN
NORMAL. HIGHS IN THE 80S OVER THE PLAINS...IN THE 60S AND 70S IN
THE MOUNTAINS...AND HUMIDITIES IN THE LOWER TEENS ARE EXPECTED
THROUGH TUESDAY. THESE CONDITIONS DAY AFTER DAY WILL LIKELY BEGIN
TAKING A TOLL ON THE FUELS AROUND THE STATE...HOWEVER CURRENTLY
THE FUELS ARE LISTED AS STILL BEING GREEN ENOUGH AFTER OUR LATE
SEASON MOISTURE. WILL KEEP EVALUATING THE FUELS EACH DAY TO
DETERMINE ANY NEED FOR FIRE WEATHER HIGHLIGHTS. RIGHT NOW WINDS
LOOK TO BE RIGHT AT OR BELOW CRITERIA. A SURFACE LOW WILL REMAIN
NEARLY STATIONARY OVER THE CO/KS/NE STATE BORDERS KEEPING MOST OF
THE AREA DRY AND LEAVING A CHANCE OF SHOWERS AND THUNDERSTORMS
EACH AFTERNOON AND EVENING OVER THE FAR NORTHEASTERN PLAINS. CAPE
VALUES EACH AFTERNOON OVER THE NORTHEAST CORNER WILL VARY BETWEEN
500-1000 J/KG WITH STORM MOTION TO THE NORTHEAST. THERE WILL BE A
VERY SMALL AMOUNT OF CAPE OVER THE MOUNTAINS SUNDAY AND
MONDAY...BUT WITH NOT MUCH MOISTURE AVAILABLE. SO ANY SHOWERS OR
THUNDERSTORMS THAT DO FORM WILL MAINLY HAVE LITTLE RAIN AND GUSTY
WINDS.
BEGINNING MONDAY NIGHT AND INTO MID-WEEK...THE PAC-NW TROUGH WILL
GET AN EXTRA SHOT OF ENERGY AND PUSH A TROUGH SOUTHEAST TOWARD THE
STATE. MODEL DIFFERENCES ARE GETTING LESS AS THE ECMWF USED TO
DEEPEN THE TROUGH INTO A CUT-OFF LOW WHICH ITS DOING LESS NOW. THE
TROUGH IS EXPECTED TO SWING FROM SOUTHWEST TO NORTHEAST ACROSS THE
STATE FROM TUESDAY NIGHT THROUGH THURSDAY. THIS WILL INCREASE
MOISTURE...SHOWER/TSTORM COVERAGE AND DECREASE TEMPERATURES OVER
THIS PERIOD. FORECAST ALREADY HAD THIS TREND...ONLY MADE MINOR
EDITS.
AVIATION...PESKY WIND FIELDS TO DEAL WITH AS A DENVER CYCLONE IS
IN AND NEAR KDEN. NORMAL DRAINAGE WIND PATTERNS SHOULD KICK IN
LATER THIS EVENING. CONVECTION IS NOT EXPECTED TONIGHT OR SATURDAY
WITH MOISTURE LACKING.
HYDROLOGY...THE NORTHEAST CORNER OF THE FORECAST AREA COULD SEE
SOME BRIEF HEAVY RAINS THIS EVENING. RAINFALL AMOUNTS COULD GET UP
TO ONE HALF OF AN INCH...BUT FLOODING ISSUES SHOULD BE MINIMAL.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM....KRIEDERMAN
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1043 AM EDT THU MAY 23 2013
.SYNOPSIS...
A BERMUDA HIGH PRESSURE SYSTEM WELL OFF THE EAST COAST WILL SLOWLY
RECEDE TODAY AND TONIGHT. A LOW PRESSURE SYSTEM MOVING THROUGH THE
SAINT LAWRENCE VALLEY WILL SLOWLY DRAG A COLD FRONT INTO AND THROUGH
THE REGION LATE TONIGHT INTO FRIDAY. A SECOND LOW PRESSURE SYSTEM
WILL DEVELOP ON THE FRONT OFF THE NEW JERSEY COAST FRIDAY AND
SLOWLY TRUNDLE NORTHEAST REACHING THE CANADIAN MARITIMES ON
MONDAY. A HIGH PRESSURE SYSTEM WILL BUILD EAST IN ITS WAKE EARLY
NEXT WEEK. A WARM FRONT IS FORECAST TO APPROACH AND MOVE THROUGH
THE FORECAST AREA ON TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WITH THE MID-MORNING UPDATE, WE DECREASED POPS SOME FOR THE NEXT
FEW HOURS ACROSS EASTERN AND SOUTHERN SECTIONS OF THE FORECAST
AREA, BASED ON CURRENT RADAR IMAGERY AND THE LATEST HRRR GUIDANCE
WHICH LOOKS TO BE CAPTURING TRENDS TODAY FAIRLY WELL. WE ALSO
DECREASED T-STORM COVERAGE FROM SCATTERED TO ISOLATED UNTIL THIS
AFTERNOON. HOURLY TEMPERATURES WERE ADJUSTED USING LAV/LAMP
GUIDANCE, AS TEMPS WERE RISING A LITTLE FASTER THAN FORECAST IN SOME
LOCATIONS. MAXIMUM TEMPERATURES LOOK ON TRACK FOR NOW, CONSIDERING
THE CONSIDERABLE CLOUD COVER ACROSS THE REGION. HOWEVER, A FEW
BREAKS ARE DEVELOPING ACROSS OUR DELMARVA REGION, AND THIS MAY
ALLOW TEMPS TO RISE TO AROUND 80 DEGREES IN SOME LOCATIONS. WE
WILL CONTINUE TO MONITOR AND UPDATE MAX TEMPS AS NEEDED.
OTHERWISE, A RAINY PERIOD IS IN STORE TODAY AS SHOWERS AND
SCATTERED THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE
THROUGH THE DAY. SURFACE LOW PRESSURE WILL MOVE OUT OF THE GREAT
LAKES AND INTO NEW ENGLAND TODAY, WHICH WILL PUSH A COLD FRONT
THROUGH CENTRAL PENNSYLVANIA AND TOWARD OUR AREA LATER TODAY.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE TO DEVELOP
AHEAD OF THE FRONTAL BOUNDARY. A PRE-FRONTAL, LEE-SIDE TROUGH IS
EXPECTED TO DEVELOP DURING THE DAY WHILE A SHORT WAVE/VORT MAX
MOVES ACROSS THE AREA AS WELL. THIS WILL LIKELY BE THE FOCUS FOR A
LINE OF SHOWERS AND THUNDERSTORMS LATE IN THE DAY. THE SPC HAS
PLACED A PORTION OF THE AREA UNDER A SLIGHT RISK FOR SEVERE
WEATHER THIS AFTERNOON. ONE LIMITING FACTOR WILL BE THE EXPECTED
CLOUD COVER ACROSS THE AREA WHICH MAY LIMIT THE AMOUNT OF
INSTABILITY ACROSS THE AREA. BUT WE COULD STILL HAVE CAPE VALUES
AROUND 500-1000 J/KG, AND WITH SHEAR VALUES AROUND 30-40 KNOTS, WE
COULD HAVE A FEW STORMS BECOME ORGANIZED ENOUGH TO PRODUCE SOME
STRONG WINDS.
ANOTHER CONCERN TODAY WILL BE HEAVY RAINFALL. PW VALUES ARE FORECAST
TO BE AROUND 1.50-1.75 INCHES. THEREFORE, SOME SHOWERS/THUNDERSTORMS
COULD BE RATHER EFFICIENT RAIN PRODUCERS. POOR DRAINAGE AND
URBAN/SMALL STREAM FLOODING IS POSSIBLE THIS AFTERNOON, ESPECIALLY
IF ANY TRAINING OCCURS.
MAV/MET MOS GUIDANCE WERE FAIRLY CLOSE, ALTHOUGH THE MAV WAS
SLIGHTLY HIGHER. WE USED A BLEND, WITH MAJORITY OF THE MAV MOS. THIS
WILL GIVE HIGHS GENERALLY IN THE MID-UPPER 70S, AND IF THE SUN COMES
OUT AT ALL FOR AN EXTENDED PERIOD OF TIME, A FEW AREAS COULD REACH
80 DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE ONGOING ACROSS THE AREA
BY WEDNESDAY EVENING AS THE PRE-FRONTAL TROUGH MAKES ITS WAY ACROSS
OUR AREA AND THE INITIAL SHORT WAVE MOVES ACROSS THE AREA.
INSTABILITY WILL LIKELY DECREASE SOME AFTER SUNSET, BUT WITH MORE
PVA EXPECTED TO TAKE PLACE OVERNIGHT IN THE CYCLONIC FLOW ALOFT,
ALONG WITH THE PASSAGE OF THE FRONTAL BOUNDARY, SHOWERS AND
THUNDERSTORMS COULD CONTINUE TO DEVELOP THROUGH THE NIGHT. THE FRONT
WILL NOT CLEAR THE ENTIRE AREA OVERNIGHT, MAY BE NEAR THE COAST BY
SUNRISE. WITH PW VALUES STILL AROUND 1.50-1.75 INCHES AHEAD OF THE
FRONT, SOME HEAVY RAIN REMAINS POSSIBLE.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NEITHER THE GFS NOR WRF-NMMB LOOKED STELLAR OFF THEIR
INITIALIZATION. IN FACT A MODEL COMPROMISE SEEMED TO LOOK THE BEST.
OVERALL THOUGH THE DP/DT WITH THE UPCOMING SYSTEM WAS SLOWER AND
THIS FCST PACKAGE DID GO THAT WAY WITH A WETTER START TO THE HOLIDAY
WEEKEND. THIS PACKAGE IS CLOSE TO THE GEFS MEAN WHICH IS SLIGHTLY
MORE PROGRESSIVE THAN THE OP GFS AND CLOSEST TO A MODELING
CONSENSUS. THE MODEL 500MB PATTERN FORECAST IS ANOMALOUS FOR LATE
MAY, SO WE DID EDGE SLIGHTLY MORE PROGRESSIVE THAN THE SLOWER
SOLUTIONS.
THE SLOWING FRONT WILL BE MOVING THROUGH OUR CWA AS WE START THE
LONG TERM. WITH THE TROF SHARPENING, IT BECOMES AN UNDERRUNNER WITH
INSTABILITY STILL PRESENT ALOFT EVEN WITH THE BOUNDARY MOVING
OFFSHORE. WE INCLUDED THE CHANCE OF THUNDER IN THE MORNING, BUT
THEORETICALLY THUNDER COULD LINGER INTO THE AFTERNOON (FRI NIGHT OFF
THE PREVIOUS ECMWF). NOT CONFIDENT ABOUT TEMP FCST AS DAYTIME MAX
TEMP MAY BE DRIVEN BY HOW FAR TEMPS FALL BY 12Z FRIDAY. KIND OF
RARE TO HAVE TEMPS GO NOWHERE ON A MAY DAY (AND ALSO HAVE THE
CALENDAR DAY HIGH POSSIBLY OCCUR AT 101 AM) AND WE SHOWED A SLIGHT
BUMP UP FOR NOW.
AS THE TROF ALOFT CLOSES, MODEL DIAGS ARE SHOWING SOME RATHER ROBUST
MID LEVEL QVEC CONVERGENCE AND FGEN FORCING FORECAST AND A
DEVELOPING MID LEVEL TROWAL OVER OUR CWA WITH THE ENTRANCE REGION
OF THE 250MB JET TO BOOT. ITS NO WONDER THAT QPF HAVE BECOME
WETTER FRIDAY NIGHT AND SATURDAY. IT STILL DEPENDS UPON HOW
QUICKLY AND FAR SOUTH THE 500MB LOW TRACKS. FOR NOW WE REMAIN MOST
CONFIDENT FOR THE NORTHEASTERN PART OF OUR CWA. WHILE POPS WERE
INCREASED FRIDAY NIGHT AND SATURDAY ACROSS THE BOARD, THE HIGHEST
REMAIN IN THE NORTHEASTERN PART OF OUR CWA. WITH ONLY THE ECMWF
SUPPORTING THUNDER FOR FRIDAY NIGHT (NONE OF THE MODELS DO ON
SATURDAY), WE PRECLUDED THEM. CONDITIONS ARE EXPECTED TO IMPROVE
AS SATURDAY MOVES ALONG, BUT WITH OUR CWA REMAINING UNDER THE
CLOSED LOW, ITS GOING TO BE TOUGH TO GET MUCH SUNSHINE BEFORE WE SELF
DESTRUCT. MIN AND MAX TEMPS WERE EDGED LOWER AND CLOSE TO A STAT
GUIDANCE COMPROMISE.
WE KEPT IN PCPN CHANCES FOR SATURDAY NIGHT NORTHEAST AND KEPT SUNDAY
DRY. WE WILL STILL BE IN THE CYCLONIC FLOW OF THE CLOSED LOW, SO
MORE SELF DESTRUCT SUNSHINE IS POSSIBLE, ESPECIALLY FARTHER
NORTHEAST ONE IS WITHIN OUR CWA. WE SHOWED A TEMPERATURE IMPROVEMENT
VS SATURDAY, CONFIDENCE THOUGH IS NOT HIGH UNTIL THE MODEL TREND
SETTLES.
WE DID NOT CHANGE MUCH IN THE REMAINDER OF THE LONG TERM. MONDAY
LOOKS TO BE THE BEST DAY ON THE HOLIDAY WEEKEND WITH TEMPERATURES
RETURNING TO NEAR NORMAL BY TUESDAY AND ABOVE NORMAL ON WEDNESDAY.
WE KEPT LOW CHANCE POPS IN ASSOCIATED WITH THE NEXT APPROACHING
WARM FRONT.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
A CLOUDY, RAINY PERIOD EXPECTED TODAY AS SHOWERS, AND POSSIBLE
THUNDERSTORMS, ARE EXPECTED TO INCREASE THROUGH THE DAY AHEAD OF AN
APPROACHING COLD FRONT. CEILINGS ACROSS MUCH OF THE REGION ARE IN
THE MVFR RANGE, AND WE EXPECT THIS TREND TO HOLD THROUGH MUCH OF
THE DAY. AS MENTIONED, SHOWERS ARE EXPECTED TO INCREASE IN COVERAGE
THROUGH THE DAY AND COULD REDUCE VSBYS IF HEAVY ENOUGH. THERE IS
ALSO THE POTENTIAL FOR THUNDERSTORMS, MAINLY THIS AFTERNOON INTO
THIS EVENING, SO WE WILL KEEP THEM IN THE FORECAST FOR NOW.
THE COLD FRONT IS NOT EXPECTED TO CROSS THE AREA UNTIL OVERNIGHT
THURSDAY INTO FRIDAY MORNING. CONDITIONS COULD LOWER MORE AHEAD OF
THE FRONTAL BOUNDARY THURSDAY NIGHT, AND SHOWERS WILL LIKELY
CONTINUE AT LEAST UNTIL THE FRONT MOVES INTO THE REGION.
OUTLOOK...
FRIDAY THROUGH SATURDAY...MVFR TO POSSIBLY IFR CONDITIONS DUE TO
CLOUDS AND SHOWERS. WORST CONDITIONS EXPECTED AT NORTHEASTERN
TERMINALS AND AIRPORTS. CONDITIONS COULD IMPROVE AS SATURDAY
CONTINUES. NORTH TO NORTHWEST WIND GUSTS COULD EXCEED 20 KTS.
SATURDAY NIGHT THRU MONDAY...MOSTLY VFR. SOME GUSTY NORTHWEST WINDS
POSSIBLE ON SUNDAY.
&&
.MARINE...
SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR TODAY AND TONIGHT AS
WINDS ARE EXPECTED TO CONTINUE TO GUST NEAR 25 KNOTS IN THE
SOUTH-SOUTHWESTERLY FLOW AHEAD OF AN APPROACHING COLD FRONT. SEAS
ARE EXPECTED TO CONTINUE TO INCREASE TO NEAR 5-6 FEET TODAY INTO
TONIGHT AS WELL.
OUTLOOK...
THE SCA FLAG HAS BEEN EXTENDED INTO FRIDAY DAY FOR NOW. WINDS MAY
NOT BE A FACTOR, BUT SWELLS SHOULD REMAIN. THE INCREASING
NORTHWEST FLOW AROUND THE DEVELOPING LOW SHOULD RESULT IN MORE
SMALL CRAFT ADVISORY CONDITIONS ON ALL OUR AREA WATERS LATER
FRIDAY INTO SATURDAY EVENING. THERE IS A SMALL CHANCE THAT EVEN
GALE FORCE WIND GUSTS MIGHT OCCUR FOR A TIME ON SATURDAY. SMALL
CRAFT ADVISORY WIND GUSTS MIGHT LINGER ON THE OCEAN INTO SUNDAY
MORNING. AFTER THAT SUB SMALL CRAFT ADVISORY CONDITIONS ARE
EXPECTED FOR THE REST OF THE HOLIDAY WEEKEND.
&&
.RIP CURRENTS...
THERE IS A MODERATE RISK FOR THE FORMATION OF DANGEROUS RIP
CURRENTS ALONG THE COAST OF NEW JERSEY TODAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ450>455.
&&
$$
SYNOPSIS...GIGI/O`HARA
NEAR TERM...KLINE/ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...GIGI
AVIATION...GIGI/ROBERTSON/O`HARA/KLINE
MARINE...GIGI/ROBERTSON/O`HARA
RIP CURRENTS...ROBERTSON/KLINE
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
355 PM EDT THU MAY 23 2013
.DISCUSSION...
TONIGHT...
H100-H70 ANTICYCLONE OVER THE N CNTRL GOMEX WILL GENERATE A DEEP NW
FLOW ACRS CENTRAL FL OVERNIGHT. LATEST RAP ANALYSIS SHOWS LIMITED
INSTABILITY ACRS CENTRAL FL...COMMON IN SUCH A FLOW REGIME. WEAK LOW
LVL PGRAD ALLOWED THE EAST COAST SEABREEZE TO DVLP BY MID
AFTN...WHICH WILL PUSH STEADILY INLAND THROUGH SUNSET. ISOLD
SHRAS/TSRAS ALONG AND N OF THE I-4 CORRIDOR SHOULD DISSIPATE BY
SUNSET WITH THE LOSS OF DAYTIME HEATING.
WEAK FRONTAL BNDRY WILL PUSH INTO THE FL STRAITS...ALLOWING A LIGHT
W/NW BREEZE TO PREVAIL OVER LAND OVERNIGHT. DEEP LYR DRY AIR
ADVECTION WILL ALLOW SKIES TO BCM MCLR OVERNIGHT...UPSTREAM SFC
DEWPOINTS OVER N FL SUGGEST MIN TEMPS IN THE M/U60S...GENERALLY
WITHIN A DEG OR TWO OF CLIMO AVG.
FRI-FRI NIGHT...
CONTINENTAL RIDGE OVER THE CENTRAL/NRN PLAINS WILL BUILD INTO THE
DEEP SOUTH...RESULTING IN A STEADY NW TO NE BREEZE THRU THE H100-H70
LYR THAT WILL BRING OVERALL DRY WX TO E CNTRL FL. LATE SEASON COOL
FRONT WILL BRING LIMITED MOISTURE TO THE CENTRAL PENINSULA...WHILE
LATEST RAP ANALYSIS INDICATES LIMITED POTENTIAL FOR MID LVL
VORTICITY ADVECTION OR UPR LVL EVACUATION.
PRECIP CHANCES WILL BE LIMITED TO AREAS S OF THE I-4 CORRIDOR...BUT
WITH LIMITED MOISTURE AND INSTABILITY TO WORK WITH...ANTICIPATE AFTN
COVERAGE AOB 20PCT...SHIFTING OFFSHORE AFT SUNSET. W/NW FLOW WILL
PREVENT SEA BREEZE FORMATION N OF THE CAPE...MAYBE LATE DAY
DEVELOPMENT ALONG THE TREASURE COAST. NEAR FULL SUN WILL ALLOW TEMPS
TO WARM TO THE U80S ALONG THE COAST...L90S INLAND. WEAK ONSHORE FLOW
WILL DVLP OVERNIGHT AS THE RIDGE AXIS DRIFTS EWD...KEEPING MIN TEMPS
SLIGHTLY ABV AVG...M/U60S INTERIOR AND U60S/L70S ALONG THE COAST.
SAT-TUE...(PREV DISC)
IT WILL BE A WARM AND DRY MEMORIAL DAY WEEKEND ACROSS THE AREA AS
NORTH-NORTHWEST FLOW ALOFT BEHIND THE TROUGH USHERS IN DRY AIR THAT
WILL STAY IN PLACE INTO EARLY NEXT WEEK.
AT THE SURFACE...STOUT ONSHORE FLOW WILL DEVELOP ON SATURDAY AS THE
SURFACE HIGH OVER THE GREAT LAKES BUILDS TO THE SOUTHEAST AND OFF
THE CAROLINA COAST WITH ITS AXIS ACROSS NORTH FLORIDA INTO NEXT WEEK.
FLOW WILL BE STRONG ENOUGH AND DEEP ENOUGH THAT A FEW ATLANTIC
SHOWERS REACHING THE COAST CAN`T BE RULED OUT...ESPECIALLY ACROSS
THE TREASURE COAST WHERE MOISTURE WILL BE HIGHER. HOWEVER THE
PROBABILITY THIS FAR OUT REMAINS TO LOW TO MENTION.
ONSHORE FLOW WILL KEEP HIGH TEMPERATURES A FEW DEGREES COOLER IN THE
LOW-MID 80S ALONG THE COAST AND MID-UPPER 80S INLAND. POST FRONTAL
DRY AIR AND MOSTLY CLEAR SKIES SHOULD ALLOW TEMPERATURES TO DROP
INTO THE LOW TO MID 60S ACROSS THE INTERIOR SAT-SUN NIGHTS BEFORE
THE GRADUALLY MOISTENING IN ONSHORE FLOW BRINGS LOWS UP IN THE
MID-UPPER 60S. COASTAL TEMPS REMAIN WARM AND MUGGY IN THE LOW-MID
70S. LOCATIONS WHERE WINDS DROP OVERNIGHT OR WEAK DRAINAGE FLOW
DEVELOPS MAY DROP SEVERAL MORE DEGREES INTO THE MID 60S.
&&
.AVIATION...
VFR ALL SITES UNLESS OTHERWISE NOTED. BTWN 23/20Z-23/24Z...ISOLD
MVFR SHRAS/IFR TSRAS E OF KDAB-KOBE. BTWN 24/08Z-24/12Z...LCL IFR
CIGS/VSBYS IN BR.
&&
.MARINE...
TONIGHT...LIGHT TO GENTLE E/SE BREEZE NEARSHORE THRU SUNSET DUE TO
THE INLAND MOVING EAST COAST SEA BREEZE...WRLY BREEZE OFFSHORE IN
THE WAKE OF A WEAK FRONTAL BNDRY PUSHING INTO THE FL STRAITS.
SFC/BNDRY LYR WINDS LIGHT AND VARIABLE BCMG W/SW OVERNIGHT AS HI
PRES OVER THE CENTRAL GOMEX IS ABSORBED BY A LARGER CONTINENTAL
RIDGE BUILDING OUT OF THE CENTRAL/NRN PLAINS. SEAS MAINLY 2-3FT...
UP TO 4FT IN THE GULF STREAM N OF CAPE CANAVERAL.
FRI-FRI NIGHT...LIGHT TO GENTLE NW WINDS BCMG N/NE THRU THE DAY AS
THE CONTINENTAL RIDGE BUILDS INTO THE DEEP SOUTH. LCL PGRAD WILL
TIGHTEN LATE FRI NIGHT AS THE RIDGE BUILDS INTO THE REGION...WINDS
WILL RESPOND BY FRESHENING TO 10-15KTS NEARSHORE AND ARND 15KTS
OFFSHORE. SEAS 2-3FT NEARSHORE AND 3-4FT OFFSHORE THRU LATE FRI
NIGHT...BUILDING TO 3-5FT N OF SEBASTIAN INLET AND 2-4FT S OF THE
INLET BY DAYBREAK SAT.
MEMORIAL DAY WEEKEND...(PREV DISC)
MODELS HAVE BACKED OFF SLIGHTLY ON THE MAGNITUDE OF THE NORTHEAST
WINDS SURGE SAT MORNING...THOUGH STILL EXPECT SPEEDS AROUND 15-20KTS
THROUGH LATE SAT NIGHT AS HIGH PRESSURE BUILDS IN BEHIND THE FRONTAL
BOUNDARY. WINDS WILL DIMINISH SLIGHTLY INTO THE OVERNIGHT HOURS INTO
SUNDAY AS THEY VEER TO THE EAST AROUND 15KTS. LIGHTEST WINDS WILL BE
NORTH OF CAPE CANAVERAL INTO MONDAY AT 10-15KTS WHICH WILL BE
CLOSEST TO THE RIDGE AXIS.
WIND SURGE WILL BRING SEAS TO AROUND 6FT OFFSHORE SAT
AFTERNOON/NIGHT WITH THE OFFSHORE FLOW KEEPING HEIGHTS 4-5FT THROUGH
THE REMAINDER OF THE HOLIDAY WEEKEND.
&&
.FIRE WEATHER...
NWRLY TRANSPORT FLOW WILL GENERATE MODERATE DRY AIR ADVECTION THRU
THE END OF THE WEEK...RESULTING IN LITTLE IF ANY MEASURABLE PRECIP.
RH VALUES ALONG AND N OF THE I-4 CORRIDOR WILL FALL BLO 35PCT FOR A
FEW HRS EACH AFTN...BUT SFC PGRAD SHOULD BE LOOSE ENOUGH TO ALLOW
THE EAST COAST SEA BREEZE TO DEVELOP...KEEPING COASTAL AFTN RH
VALUES NEAR 50PCT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 70 88 68 80 / 10 10 0 0
MCO 69 92 69 86 / 10 10 0 0
MLB 71 88 72 81 / 10 20 10 0
VRB 71 88 72 82 / 10 20 10 0
LEE 69 91 66 86 / 10 10 0 0
SFB 69 91 69 85 / 10 10 0 0
ORL 70 92 69 86 / 10 10 0 0
FPR 71 89 72 82 / 10 20 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...PENDERGRAST
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
345 PM EDT THU MAY 23 2013
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A RATHER CHAOTIC UPPER
LEVEL PATTERN IN PLACE ACROSS THE CONUS. PATTERN IS DOMINATED BY
THREE LONGWAVE FEATURES. LOOKING FAR UPSTREAM WE FIND A LARGE AND
VIGOROUS UPPER LEVEL LOW SPINNING OVER THE PACIFIC NORTHWEST. MAIN
FLOW AROUND THE SOUTHERN PERIPHERY OF THIS CIRCULATION EMERGES
THROUGH THE FOUR-CORNERS REGION AND THEN RIDGES UP OVER THE CENTRAL
PLAINS. THIS FLOW THEN QUICKLY DIVES BACK TO THE SOUTHEAST AND
MERGES WITH AN IMPRESSIVE LONGWAVE TROUGH PIVOTING THROUGH MUCH OF
EASTERN CANADA AND THE EASTERN CONUS. OUR FORECAST AREA RESIDES NEAR
THE SOUTHERN PERIPHERY/BASE OF THIS EASTERN TROUGH. WV IMAGERY
CLEARLY DEFINES A WEAK SHORTWAVE EMBEDDED WITHIN THE FLOW WITHIN THE
BASE OF THE LONGWAVE TROUGH WHICH IS PIVOTING THROUGH THE REGION
THIS AFTERNOON...AND WILL BE OFF TO OUR EAST BY TONIGHT.
MID/UPPER LEVEL DRY AIR IS EXPANDING ACROSS THE REGION WITH WEAK NVA
AND LARGE SCALE SUBSIDENCE IN THE WAKE OF THIS DEPARTING SHORTWAVE.
AT THE SURFACE...A WEAK PRESSURE GRADIENT IS RESULTING IN MAINLY
SEA-BREEZE DOMINATED FLOW LATE TODAY. THE WEST COAST SEA-BREEZE IS
QUICKLY BEGINNING TO TRANSLATE INLAND CLEARING THE DIURNAL CUMULUS
FIELD AWAY FROM THE BEACHES. MAY STILL SEE A FEW INTERIOR ISOLATED
CONVECTIVE CELLS INTO THE EARLY EVENING...HOWEVER COVERAGE LOOKS TO
BE SIGNIFICANTLY LESS THAN WHAT WAS EXPERIENCED THE PAST COUPLE OF
DAY.
&&
.SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...
TONIGHT...
LARGE SCALE SUBSIDENCE PATTERN SUGGESTS ANY LINGERING STORMS BY
MID-EVENING WILL BE OVER TOWARD THE I-95 CORRIDOR WHICH SHOULD SET
UP A MAINLY DRY...QUIET AND SEASONABLE OVERNIGHT PERIOD FOR OUR
ZONES. TEMPERATURES WILL GENERALLY DROP TO THE MID 60S TO LOWER 70S
BY SUNRISE ON FRIDAY...WITH THE NORMALLY COLDER INLAND SPOTS DOWN
INTO THE LOWER 60S.
FRIDAY/FRIDAY NIGHT...
EASTERN CONUS UPPER LEVEL TROUGH IS FORECAST TO SHARPEN AS ITS AXIS
REACHES THE ATLANTIC COAST DURING FRIDAY. SURGE OF ENERGY ROUNDING
THE BASE OF THIS TROUGH DURING THIS TIME WILL PASS TO OUR
NORTH...HOWEVER IT WILL ACT TO PROPEL A LATE SEASON TROUGH/FRONT
DOWN AND ACROSS THE FL PENINSULA. SIGNIFICANTLY DRIER AIR WILL BE
ARRIVING BEHIND THIS FRONT...ESPECIALLY ABOVE THE SURFACE WHICH
SHOULD SUPPRESS MUCH IF NOT ALL OF THE DIURNAL CONVECTION FROM THE
TAMPA BAY AREA NORTHWARD ALONG THE NATURE COAST. SOME LINGERING
MOISTURE AND SEA-BREEZE COLLISION WITHIN A WEAK GRADIENT OVER THE
SOUTHERN ZONES SHOULD BE ENOUGH FOR A FEW LATE DAY STORMS...MAINLY
INLAND FROM THE I-75 CORRIDOR. STRONG CONTINENTAL HIGH PRESSURE
BEGINS TO BUILD OVER THE PENINSULA DURING FRIDAY NIGHT WITH A
TIGHTENING PRESSURE GRADIENT AND DEVELOPING NE FLOW. DRIER AIR WILL
CONTINUE TO ADVECT INTO THE AREA...EVEN AT THE SURFACE AND LEAD TO A
NOTICEABLY COOLER OVERNIGHT PERIOD. IN FACT...A FEW SPOTS UP TOWARD
CITRUS/LEVY COUNTY MAY FIND THEMSELVES BACK INTO THE 50S FOR A FEW
HOURS TOWARD DAWN ON SATURDAY.
SATURDAY/SATURDAY NIGHT...
ON THE BACKSIDE OF THE DEPARTING UPPER TROUGH...AN UNSEASONABLY DRY
MID-LEVEL AIRMASS WILL DESCEND OVER THE REGION FOR SATURDAY AND
SATURDAY NIGHT. CROSS-SECTION AND TIME-HEIGHT ANALYSIS FROM THE GFS
AND NAM BOTH SHOW AVERAGE RELATIVE HUMIDITY THROUGH THE 850-400MB
LAYER AT UNDER 10%...THAT IS DRY! IN ADDITION...THETA-E VALUES
AROUND 700MB ARE FORECAST TO DROP BELOW 315K ALMOST REGION-WIDE BY
SATURDAY AFTERNOON. THIS COMBINATION ALONG WITH THE SYNOPTIC FLOW
DISRUPTING THE SEA-BREEZE FORMATION WILL LEAD TO LITTLE IF ANY
CHANCES FOR DIURNAL CONVECTION. WILL KEEP THE FORECAST DRY FOR THE
FIRST HALF OF THE WEEKEND UNDER PLENTY OF SUNSHINE AND SEASONABLE
TEMPERATURES. THE DRY CONDITIONS WILL LEAD TO ANOTHER BELOW AVERAGE
NIGHT IN TERMS OF TEMPERATURES...WITH WIDESPREAD LOWER 60S AWAY FROM
THE COAST BY DAWN ON SUNDAY. ONCE AGAIN COLDER SPOTS ACROSS THE
NATURE COAST ARE FORECAST TO DROP INTO THE MID/UPPER 50S.
&&
.LONG TERM (SUNDAY THROUGH NEXT WEDNESDAY)...
MODEL SOLUTIONS REMAIN IN GOOD AGREEMENT SHOWING HIGH PRESSURE RIDGE
AXIS REMAINING NORTH OF THE FORECAST AREA...KEEPING AN EASTERLY
BOUNDARY LAYER FLOW IN PLACE. MOISTURE WILL REMAIN LIMITED THROUGH
MONDAY NIGHT...WITH RAIN FREE CONDITIONS EXPECTED. BOUNDARY LAYER
MOISTURE WILL INCREASE SLIGHTLY DURING THE MID WEEK TIME FRAME...SO
WILL CARRY SLIGHT CHANCE POPS FOR PORTIONS OF THE AREA TUESDAY
THROUGH THURSDAY FOR AFTERNOON/EARLY EVENING SHOWERS AND
THUNDERSTORMS.
&&
.AVIATION...
PREVAILING VFR WITH FEW-SCT CLOUDS...ISOLD TSRA EAST OF THE
TERMINALS THROUGH EARLY EVENING. LIMITED BR MAY BE POSSIBLE AT LAL
AND PGD. WESTERLY WINDS BECOME LIGHT AND VARIABLE OVERNIGHT THEN
NORTHWESTERLY DURING THE DAY.
&&
.MARINE...
WEAK HIGH PRESSURE ACROSS THE EASTERN GULF SLIDES OFF TONIGHT AS A
DRY FRONT MOVES SOUTHWARD FRIDAY AND INTO SOUTH FLORIDA. HIGH
PRESSURE BUILDS INTO THE GULF REGION SATURDAY THEN MOVES EAST...AS
IT CONTINUES TO DOMINATE THE EAST GULF WATERS. THE BUILDING HIGH
PRESSURE RESULTS IN A TIGHTENING PRESSURE GRADIENT WITH GUSTY EAST
AND NORTHEAST WINDS POSSIBLY REACHING CAUTIONARY OR LOW END ADVISORY
CRITERIA AT TIMES.
&&
.FIRE WEATHER..
A LATE SEASON FRONT WILL DROP SOUTH ACROSS THE REGION FRIDAY AND
FRIDAY NIGHT ALLOWING A MUCH DRIER AIRMASS TO FILTER IN FROM THE
NORTH FOR THE UPCOMING WEEKEND. RELATIVE HUMIDITY VALUES ARE
FORECAST TO DROP BELOW CRITICAL VALUES FOR A PERIOD FRIDAY AFTERNOON
AWAY FROM THE COAST WITH THE LOWEST VALUES AND LONGEST DURATIONS
FROM THE I-4 CORRIDOR AND NORTHWARD. ANOTHER DAY WITH A PERIOD OF
CRITICALLY LOW RELATIVE HUMIDITY IS ANTICIPATED FOR SATURDAY. A
NORTHEAST WIND WILL HELP BRING THESE LOW RELATIVE HUMIDITY VALUES
BACK CLOSER TO THE COAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 73 91 69 87 / 0 0 0 0
FMY 72 92 70 91 / 10 10 10 10
GIF 71 93 67 90 / 10 10 10 0
SRQ 71 90 70 90 / 0 0 0 0
BKV 65 91 62 87 / 0 10 10 0
SPG 75 90 73 87 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/FIRE WX...MROCZKA
AVIATION/MARINE/DECISION SUPPORT...RUDE
LONG TERM...JELSEMA
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1057 AM EDT Thu May 23 2013
.NEAR TERM [Rest of Today]...
The 12 UTC sounding from our office had a relatively moist profile
with a PWAT of 1.53". However, drier air is situated just to the
northwest, with the Birmingham (BMX) sounding indicating much
drier air in the 950-800mb layer. This is portrayed in the latest
objective RAP analysis which shows the leading edge of the drier
air just arriving in our southeast Alabama zones. This is expected
to push into the northwest half of our area by early afternoon,
and as boundary layer mixing increases, surface dewpoints should
decrease markedly. The advection of drier air from the northwest
will also set up a low-level thetae gradient somewhere near an
AAF-VLD line by afternoon. Various convection-allowing models show
scattered showers and thunderstorms developing in the unstable
environment ahead of this boundary in the afternoon - mainly in
Taylor, Lafayette, and Dixie counties. Therefore, a 20% PoP was
added in areas southeast of Tallahassee. It wouldn`t be out of the
question for some of the storms to produce some hail or gusty
winds, but widespread or organized severe weather is not expected.
Otherwise, it looks like a mostly sunny and seasonably warm day
with highs within a couple degrees of 90 in most spots.
&&
.SHORT TERM [Tonight through Sunday]...
TONIGHT...the large scale longwave pattern remains highly amplified
with full latitude trough over Wrn, ridge over Cntrl and trough over
Ern states followed by ridge over extreme Wrn Atlc. Low assocd with
Ern trough continuing to weaken as it shears NEWD. At surface, low
vcnty PA with weakening cold front Swd to N GA then SWWD across SE
AL. During the rest of overnight hours, axis of Ern trough to move
to Ern seaboard with rapidly weakening mainly dry front reaching
extreme Nrn Gulf waters by sunrise FRI.
FRIDAY THRU SUNDAY...By Fri eve, trough axis and assocd low just
off Ern seaboard. In their wake, upper ridge will build NWD from
Wrn Gulf of Mex while surface high pressure builds SWD from the
OH/ TN Valleys to the Nrn Gulf. Assocd ridge will continue to
build SEWD Fri night into SAT with high centered NNE of region.
Locally this places local area between departing trough and
advancing upstream ridge yielding a much cooler and drier airmass
with NW steering flow. Flow aloft becoming WNW by Sun, and with
NLY flow at lower levels veering to NE on Sat and ESE on Sun. The
result is a reinforcing dry airmass heralding an ideal weekend
with mostly clear skies, low dew points and cool nights.
10% pops tonight then no POPs thru period. Inland Lows tonight low
to mid 60s dropping Fri and Sat nights in wake of front to mid 50s.
Highs generally mid to upper 80s. Invading drier air should limit
fog chances thru period.
&&
.LONG TERM [Sunday Night through Wednesday]...
Upper ridging will build over the area through Memorial Day and
into the middle of next week. This will leave somewhat tranquil
conditions in place with a seasonably cool start to the period and
a gradual warm up into the early part of the week, with little or
no rain outside of possible isolated showers along the sea breeze.
&&
.AVIATION...[through 06 UTC Friday]
Areas of fog will develop in the pre-dawn hours. Some of the fog may
become dense especially in places that received rain. VFR conditions
will return across the entire region after 14Z. Winds will be from
the west to northwest in the 10 to 15 knot range with higher
gusts.
&&
.MARINE...
Fairly low winds and seas will persist into Friday, when offshore
winds will increase in the wake of a surface cold front late
Friday night into Saturday. Seas will eventually build as well in
the offshore legs with cautionary wind speeds expected Friday night.
winds will veer and along with seas decrease thru the rest of the
weekend.
&&
.FIRE WEATHER...
A much drier airmass will be filtering into the region over the next
few days. Today the minimum relative humidity should stay above
critical levels but is forecast to drop at or just below 28 percent
over interior portions of the Florida Panhandle and western Big Bend
Friday afternoon. This combined with elevated ERC values and
sustained winds at or above 15 mph will possibly meet Red flag
conditions. A fire weather watch has been posted and may be upgraded
to a warning later today. A fire weather watch will also be issued
for our SE Alabama counties Friday due to a combination of long
durations of low RH, KBDI over 500 and sustained winds at or above
10 mph. Low relative humidities are also expected across our Georgia
zones Friday but the 10-hour fuel moisture should remain above 6
percent. Red Flag conditions are also possible across portions of
north Florida and our southeast Alabama counties again on Saturday.
On top of all this, dispersions will be very high across north
Florida this afternoon and again on Friday with forecast values
approaching 120.
&&
.HYDROLOGY...
No issues are forecast along area rivers for the foreseeable future.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 92 66 89 56 87 / 10 10 10 10 0
Panama City 87 75 87 66 81 / 10 10 10 10 0
Dothan 91 66 87 55 86 / 0 10 10 10 0
Albany 90 64 85 55 85 / 10 10 10 10 0
Valdosta 92 63 87 56 85 / 10 10 10 10 0
Cross City 88 67 89 58 86 / 20 10 10 10 0
Apalachicola 84 72 87 66 82 / 10 10 10 10 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...FIRE WEATHER WATCH from Friday afternoon through Friday
evening for Calhoun-Gadsden-Holmes-Inland Walton-Jackson-
Liberty-Washington.
GA...None.
AL...FIRE WEATHER WATCH from Friday afternoon through Friday
evening for Coffee-Dale-Geneva-Henry-Houston.
GM...None.
&&
$$
NEAR TERM...Lamers
SHORT TERM...Block
LONG TERM...Evans
AVIATION...Barry
MARINE...Block
FIRE WEATHER...Barry
HYDROLOGY...Evans/Block
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
950 AM EDT THU MAY 23 2013
.UPDATE (REST OF TODAY AND TONIGHT)...
13Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A RATHER CHAOTIC UPPER
LEVEL PATTERN IN PLACE ACROSS THE CONUS. PATTERN IS DOMINATED BY
THREE LONGWAVE FEATURES. LOOKING FAR UPSTREAM WE FIND A LARGE AND
VIGOROUS UPPER LEVEL LOW SPINNING OVER THE PACIFIC NORTHWEST. MAIN
FLOW AROUND THE SOUTHERN PERIPHERY OF THIS CIRCULATION EMERGES
THROUGH THE FOUR-CORNERS REGION AND THEN RIDGES UP OVER THE CENTRAL
PLAINS. THIS FLOW THEN QUICKLY DIVES BACK TO THE SOUTHEAST AND
MERGES WITH AN IMPRESSIVE LONGWAVE TROUGH PIVOTING THROUGH MUCH OF
EASTERN CANADA AND THE EASTERN CONUS. OUR FORECAST AREA RESIDES NEAR
THE SOUTHERN PERIPHERY/BASE OF THIS EASTERN TROUGH. WV IMAGERY
CLEARLY DEFINES A WEAK SHORTWAVE EMBEDDED WITHIN THE FLOW WITHIN THE
BASE OF THE LONGWAVE TROUGH WHICH WILL PIVOT THROUGH THE REGION THIS
MORNING AND EARLY AFTERNOON.
BEHIND THIS SHORTWAVE FOR THE SECOND HALF OF THE DAY/EVENING THE
DEPTH OF DRY AIR WITHIN THE COLUMN WILL INCREASE (ESPECIALLY OVER
THE NORTHERN HALF OF THE AREA AS WEAK NVA AND DEEP LAYER SUBSIDENCE
ARRIVES FROM THE WEST AND NORTHWEST.
THE PASSAGE OF THIS SHORTWAVE TO OUR EAST BEFORE THE TIME OF PEAK
DIURNAL HEATING WILL WORK IN THE FAVOR FOR THOSE LOOKING FOR LESS
CONVECTIVE ACTIVITY THAN HAS BEEN SEEN THE PAST COUPLE OF DAYS.
STILL UNLIKELY THAT THIS SETUP WILL BE ENOUGH TO COMPLETELY SUPPRESS
THE THUNDERSTORM THREAT FOR ALL AREAS. SEEING A FEW FAVORABLE
ASPECTS IN THE SHORT TERM FOR UPDRAFT INITIATION AND SUPPORT. WILL
BE WATCHING A WEAK LOW LEVEL TROUGH DROP SOUTH TOWARD THE I-10
CORRIDOR EARLY THIS AFTERNOON. LOW LEVEL FOCUS ALONG AND JUST SOUTH
OF THIS BOUNDARY MAY BE ENOUGH TO SUPPORT A FEW SHOWERS/STORMS UP
TOWARD LEVY COUNTY BY MID AFTERNOON BEFORE THE MORE SIGNIFICANTLY
HOSTILE AIR ALOFT TOWARD CONVECTION ARRIVES. LOCAL HIGH-RES WRFARW
SIMULATIONS ARE IN FAVOR OF THIS CONVECTIVE DEVELOPMENT...BUT ALSO
KEEP THE CONVECTION FAIRLY SHALLOW WITH UPDRAFT RATES THAT ARE
GENERALLY UNSUPPORTIVE OF SIGNIFICANT WEATHER. BY THIS
EVENING...THETA-E VALUES AROUND 700MB ARE WELL BELOW 320K UP TOWARD
CHIEFLAND WHICH WILL MAKE IT VERY DIFFICULT FOR ANY CUMULUS TOWERS
ATTEMPTING TO GROW.
THE OTHER AREA WE AREA LOOKING FOR WIDELY SCATTERED CONVECTIVE
ACTIVITY IS ACROSS OUR INTERIOR SOUTHERN ZONES...MAINLY WELL INLAND
FROM I-75. MORE FAVORABLE MOISTURE PROFILES WILL HOLD ON A LITTLE
LONGER DOWN TOWARD THESE AREA...AND A RAPID INLAND PROPAGATION OF
THE SEA-BREEZE WILL ADD SOME LOWER LEVEL FOCUS.
LESS CONVECTIVE ACTIVITY AND 850MB TEMPS OF 16-17C GIVE THE
BOUNDARY LAYER A WARM POTENTIAL TODAY. THOSE AREAS NOT SEEING ANY
QUICK SHOWER AND AWAY FROM THE BEACHES SHOULD EASILY MIX OUT INTO
THE LOWER 90S...WITH WARMER SPOTS PEAKING IN THE MID 90S. ONSHORE
FLOW DEVELOPING QUICKLY TODAY WILL HOLD THE BEACHES IN THE 80S.
PATTERN SUGGESTS ANY LINGERING STORMS BY MID-EVENING WILL BE OVER
TOWARD THE I-95 CORRIDOR WHICH SHOULD SET UP A MAINLY DRY...QUIET
AND SEASONABLE OVERNIGHT PERIOD. ENJOY!
&&
.AVIATION...
PREVAILING VFR WITH FEW-SCT CLOUDS. LIGHT AND VARIABLE WINDS BECOME
WESTERLY LATE MORNING AND AFTERNOON...KEEPING LIMITED TSRA EAST OF
THE TERMINALS.
&&
.MARINE...
WINDS AND SEAS WILL REMAIN RATHER LIGHT THROUGH TODAY AND
TONIGHT. A WEAKENING COLD FRONT WILL SLIDE SOUTHWARD THROUGH THE
WATERS FRIDAY AND FRIDAY NIGHT...WITH STRONG HIGH PRESSURE THEN
BUILDING NORTH OF THE STATE OVER THE WEEKEND INTO EARLY NEXT WEEK.
ELEVATED EASTERLY FLOW WILL LIKELY RESULT IN A NEED FOR EXERCISE
CAUTION OR ADVISORY HEADLINES FOR MUCH OF THE MARINE AREA DURING THE
EVENING AND OVERNIGHT HOURS EACH DAY THROUGH THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 90 73 91 71 / 0 0 0 0
FMY 91 72 91 72 / 10 10 10 10
GIF 92 71 93 68 / 20 10 10 0
SRQ 86 71 89 71 / 0 0 0 0
BKV 90 65 91 63 / 10 0 10 0
SPG 90 75 89 74 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1103 AM CDT THU MAY 23 2013
.DISCUSSION...
240 AM CDT
TODAY...
FORECAST CHALLENGES FOR TODAY RESIDE WITH HIGH TEMPS...AND PRECIP
CHANCES THIS MORNING.
IR IMAGERY EARLY THIS MORNING SHOWS CONSIDERABLE CLOUD COVER
REMAINING ACROSS THE WESTERN GREAT LAKES...EXTENDING SOUTH THROUGH
THE MID-MISSISSIPPI VALLEY. ALONG THE WESTERN PERIPHERY OF THE CLOUD
COVER LIES THE LEADING EDGE OF THE STRONG SFC RIDGE...BEGINNING TO
PUSH INTO THE UPPER MIDWEST/NORTHERN PLAINS. MOISTURE HAS BEEN
CONSISTENTLY PEELING OFF TO THE NORTHEAST...NOTED IN THE STEADILY
LOWERING DEW POINTS. DEW POINTS ACROSS CENTRAL WISC HAVE ALREADY
FALLEN INTO THE UPR 40S...AND EXPECT THIS TREND TO EVENTUALLY ARRIVE
ACROSS NORTHERN IL/NORTHWEST IN. A BROAD SFC TROUGH WAS ANALYZED
ACROSS NORTHEAST IL STRETCHING INTO SOUTHCENTRAL LOWER MI. AS A
RESULT SFC WINDS ACROSS THE CWFA HAVE MAINLY BEEN FROM THE
WEST/SOUTHWEST...HOWEVER JUST NORTH OF THE CWFA INTO WISC WINDS HAVE
ALREADY SHIFTED TO THE NORTHWEST/NORTH. LOCATIONS ADJACENT TO LAKE
MICHIGAN WILL SEE WINDS FLOP OVER TO THE NORTHEAST THIS
MORNING...ALLOWING THE MUCH COOLER MARINE ENVIRONMENT TO READILY
FLOW ACROSS THE LAND.
REGIONAL RADAR EARLY THIS MORNING SHOWS AN AREA OF SHOWERS ACROSS
CENTRAL WISC...SLOWLY SLIDING SOUTHEAST. HI-RES GUIDANCE SUGGESTS
THIS CHANNEL OF PRECIP WILL EVENTUALLY ARRIVE ACROSS NORTHERN IL
JUST BEFORE DAYBREAK. AS A RESULT OF THE INCREASED CONFIDENCE IN
PRECIP...HAVE NUDGED THE 12-15Z TIMEFRAME TO LIKELY POPS FOR FAR
NORTHEAST IL.
DRY AIR CONTINUES TO POUR INTO THE REGION MID-MORNING...AND SHOULD
BRING AN END TO THE PRECIP FROM NORTHWEST TO SOUTHEAST ACROSS THE
CWFA BY EARLY THIS AFTERNOON. THE STEADY PUSH OF DRY AIR WILL ALSO
AID IN ERODING THE CLOUD COVER...AND BY LATE THIS AFTERNOON EXPECT
MOSTLY SUNNY SKIES TO DEVELOP. COLD AIR ADVECTION WILL DOMINATE THE
DAY...COUPLED PRECIP AND CLOUDS...EXPECT MUCH COOLER TEMPS FOR THIS
AFTERNOON. GUIDANCE HAS CONTINUED TO SUGGEST TEMPS WILL STRUGGLE TO
WARM BEYOND THE LOW 60S FOR THE FAR WESTERN CWFA...MEANWHILE FURTHER
EAST TEMPS WILL ONLY WARM A FEW DEGREES FROM THEIR STARTING POINT.
THIS WILL MOST LIKELY LEAD TO AREAS EAST OF I-39 ONLY WARMING INTO
THE MID/UPR 50S. LOCATIONS IMMEDIATELY ADJACENT TO LAKE MICHIGAN
COULD SEE TEMPS STRUGGLE TO WARM BEYOND 50 DEGREES.
CONFIDENCE IN PRECIP ENDING TIME...MEDIUM/HIGH.
CONFIDENCE IN TEMPERATURES...HIGH.
TONIGHT...
ANTI-CYCLONIC FLOW WILL CONTINUE TO BUILD OVERHEAD EARLY THIS
EVENING...AND ERODE ANY LINGERING CLOUDS BY MIDNIGHT. DEW POINTS AS
A RESULT WILL CONTINUE TO DRY...BOTTOMING OUT IN THE MID 30S IN MANY
LOCATIONS. THE COMBINATION OF NEAR CLOUDLESS SKIES...LIGHT NORTH TO
AT TIMES CALM WINDS...AND RECENT RAINFALL...WILL SET THE STAGE FOR
NOT ONLY STRONG RADIATIONAL COOLING BUT PATCHY FROST AWAY FROM LAKE
MICHIGAN. GUIDANCE CONTINUES TO PROG TEMPS FALLING OVERNIGHT INTO
THE MID/UPR 30S FOR AREAS WEST OF WAUKEGAN TO KANKAKEE. FAR SOUTHERN
PORTIONS OF THE CWFA SHOULD HAVE TEMPS HOLD ARND 40 DEGREES
OVERNIGHT...HOWEVER A FEW LOW-LYING AREAS COULD SEE SPOTTY FROST. AT
THIS POINT IT DOES NOT APPEAR TO BE A WIDESPREAD FROST SETUP...SO
WILL HOLD OFF ON ANY HEADLINES AT THIS POINT.
CONFIDENCE...HIGH.
FRIDAY...
SFC HIGH PRESSURE WILL DOMINATE THE REGION FOR THE END OF THE
WEEK...AND MORE THAN LIKELY ONLY ALLOW A FEW DIURNAL CLOUDS TO
DEVELOP. A LIGHT NORTHEAST FLOW OFF OF LAKE MICHIGAN WILL CONTINUE
TO KEEP ADJACENT AREAS MUCH COOLER IN THE MID/UPR 50S...MEANWHILE
INLAND LOCATIONS WILL BEGIN TO WARM INTO THE LOW/MID 60S.
WITH HIGH PRESSURE STILL IN CONTROL FRIDAY NIGHT...EXPECT ANOTHER
NIGHT OF STRONG RADIATIONAL COOLING. THE ONLY DIFFERENCE FOR FRI
NIGHT WILL BE THE RIDGE AXIS WILL HAVE SHIFTED EAST. THIS WILL ALLOW
THE LIGHT WINDS TO BEGIN TURNING SOUTHEASTERLY AFTER MIDNIGHT...AND
COULD SLOW THE RATE OF COOLING. HAVE MAINTAINED TEMPS IN THE LOW 40S
FOR MANY AREAS. COULD SEE A FEW OF THE TRADITIONAL COOL SPOTS DIP TO
THE UPR 30S EARLY SAT MORNING...HOWEVER AT THIS POINT NOT
ANTICIPATING FROST FORMATION.
CONFIDENCE IN TEMPERATURES...HIGH.
SATURDAY...
DISCREPANCIES BEGIN TO EMERGE AMONGST SOLUTIONS FOR SAT...WITH
RESPECT TO PLACEMENT/TIMING OF A MOIST BOUNDARY. GFS HAS CONTINUED
TO BE THE MORE PROGRESSIVE SOLUTION...BRINGING THIS CHANNEL OF
MOISTURE/PRECIP INTO THE REGION AND STRETCHES FROM THE NORTHERN
PLAINS SOUTHEAST THROUGH THE OHIO VALLEY. MEANWHILE THE EC HAS
MAINTAINED THE SFC RIDGE...AND SUPPRESSING THE MOIST CHANNEL TO THE
SOUTHWEST OF THE CWFA.
THE LARGEST WEATHER PLAYER IS THE DOWNSTREAM 500MB RIDGE LOCATED
ACROSS THE WESTERN ATLANTIC. THIS WILL ACT AS A BLOCK...SLOWING THE
DEPARTURE OF THE MID-LVL TROUGH ACROSS THE MID-ATLANTIC REGION. THEN
FURTHER UPSTREAM YET ANOTHER 500MB RIDGE WAS PROGGED TO ARRIVE
ACROSS THE CENTRAL CONUS...AND DOES SHOW SOME SIGNS OF
AMPLIFICATION. BASED ON THIS SETUP IT IS BECOMING MORE EVIDENT THAT
SAT COULD END UP BEING DRY...AND POSSIBLY EXTEND INTO SUN. AT THIS
POINT HAVE ONLY ADJUSTED POPS SAT MARGINALLY...TO SLIGHT CHANCE
WORDING.
SFC TEMPS WILL REMAIN UNSEASONABLY COOL IN THE LOW/MID 60S...WITH
AREAS ADJACENT TO LAKE MICHIGAN BEING EVEN COOLER THAN THIS. DESPITE
THE EXPECTED SOUTHEAST COMPONENT TO THE SFC WINDS...ENOUGH HEATING
COULD ALLOW A LAKE BREEZE TO FORM AND ALLOW WINDS TO BECOME MORE
EASTERLY FOR LOCATIONS ADJACENT TO LAKE MICHIGAN. THIS WILL MOST
LIKELY RESULT IN THOSE AREAS IMMEDIATELY NEXT TO THE LAKE REMAINING
IN THE 50S SAT AFTN.
CONFIDENCE...MEDIUM.
SUNDAY THROUGH WEDNESDAY...
FOR THE EXTENDED PERIODS GUIDANCE HAS CONTINUED TO DEMONSTRATE
MINIMAL CHANGES FROM PREVIOUS SOLUTIONS...HOWEVER OPERATIONAL
ECMWF/GFS CONTINUE TO DIFFER ON THE PLACEMENT/TIMING OF PRECIP. THE
ECMWF CONTINUES TO SUGGEST THE SFC RIDGE FROM LATE IN THE WEEK WILL
HOLD TOUGH AND KEEP NORTHERN IL/NORTHWEST IN DRY THRU THE WEEKEND
AND INTO EARLY NEXT WEEK. MEANWHILE THE GFS IS STILL MORE
PROGRESSIVE AND BRINGS THE BOUNDARY OVERHEAD AND BECOMES
QUASI-STATIONARY THRU THE FIRST HALF OF NEXT WEEK.
ENSEMBLES CONTINUE TO INDICATE THE WESTERN ATLANTIC MID-LVL RIDGE
WILL WEAKEN...ALLOWING THE 500MB TROUGH TO FINALLY EJECT EAST. IN
ADDITION THE UPSTREAM RIDGE WILL BEGIN TO FLATTEN...LEADING TO A
SOMEWHAT PROGRESSIVE FLOW OF SYSTEMS FROM WEST TO EAST TOWARDS THE
MIDDLE OF NEXT WEEK. THUS PRECIP CHC WILL BE ON THE INCREASE TOWARDS
THE FINAL FEW PERIODS OF THE CURRENT EXTENDED FORECAST.
BY TUE/WED OF NEXT WEEK...TEMPS COULD EASILY BE BACK INTO THE UPR
70S TO LOW 80S.
CONFIDENCE IN PRECIPITATION...LOW.
CONFIDENCE IN TEMPERATURES...HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* VARIABLE MVFR/IFR CIG SLOWLY IMPROVING AOA 1500 FT AROUND 17Z.
VFR/CLEARING BY MID AFTN.
* NORTH WIND WITH GUSTS TO AROUND 30 KT CONTINUING THROUGH AFTN.
ALLSOPP/BMD
//DISCUSSION...UPDATED 12Z...
MAIN CONCERN THIS MORNING IS CIG TRENDS...THEN THIS AFTERNOON
FOCUS WILL BE ON STRONG GUSTY NNE WINDS. LOW PRESSURE WAS OVER
THE EASTERN GREAT LAKES WITH A COLD FRONT TRAILING WESTWARD INTO
NORTHERN IL. AT 11Z THE FRONT WAS FROM ABOUT IKK-VYS. BASED ON
NAM AND HRRR MODEL SOUNDINGS...CIGS SHOULD SLOWLY IMPROVE TO
AROUND 1000-1200 FT IN THE NEXT COUPLE HOURS. THIS SEEMS
REASONABLE WITH STRONGER WINDS MIXING COLDER AND SLIGHTLY DRIER
AIR DOWN FROM THE NORTH. ALSO SPOTTY LIGHT RAIN/DRIZZLE WILL BE
DIMINISHING/MOVING OUT AND THAT MAY ALSO HELP IMPROVE CIG AND VSBY
A BIT THIS MORNING. AS OF 11Z THE BACK EDGE OF THE MAIN BAND OF
RAIN ASSOCIATED WITH THE COLD FRONT WAS LINED UP FROM DKB-DPA-
MDW-GYY AND SINKING VERY SLOWLY S. THERE WERE SOME VSBY
RESTRICTIONS DOWN TO 2-3 MILES IN THIS BAND OF RAIN...BUT IT HAS
PUSHED SOUTH OF THE TERMINALS. FURTHER NORTH INTO SOUTHERN WI
THERE WERE SOME PATCHES OF LIGHT RAIN/DRIZZLE..BUT THIS WAS VERY
LIGHT. SHORT RANGE/HI RES MODELS SUGGEST THIS SPOTTY LIGHT RAIN
WILL BE DRYING UP AND MOVING SE OUT OF THE AREA BY MID TO LATE
MORNING. THEREFORE DONT EXPECT ANY SIGNIFICANT VSBY RESTRICTIONS
BELOW 5 OR 6 MILES THE REST OF THE MORNING. AS STRONG NORTH WINDS
CONTINUE TO PUSH COLDER DRIER AIR DOWN...EXPECT CLOUDS TO LIFT TO
1500 FT OR BETTER BY NOON AND BREAK UP THIS AFTERNOON WITH
CLEARING MID TO LATE AFTN.
NORTH WINDS HAVE PICKED UP AND WINDS WILL CONTINUE TO INCREASE TO
20 TO 30 KT BY MID MORNING. DIRECTION MAY VARY SOME FROM 350-030
BUT WILL BE PREDOMINANTLY JUST E OF N TODAY. PRESSURE GRADIENT
SLOWLY BEGINS TO RELAX LATE THIS AFTERNOON AND WINDS MAY DIMINISH
SLIGHTLY DURING THE LATE AFTN. ATMOSPHERE SHOULD BEGIN TO DECOUPLE
THIS EVENING AS PRESSURE GRADIENT CONTINUES TO RELAX.
OUTLOOK FOR FRIDAY IS VFR WITH LIGHT NORTHEAST WINDS.
ALLSOPP
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-HIGH CONFIDENCE IN CIG TRENDS THIS MORNING.
* MEDIUM CONFIDENCE IN TIMING OF CLEARING THIS AFTN.
* HIGH CONFIDENCE IN WIND FORECAST. DIRECTION MAY VARY FROM
350-030.
ALLSOPP/BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT AND SATURDAY...VFR. WX NIL.
SUNDAY AND MONDAY...VFR. CHC SHRA SLIGHT CHC TSRA.
TUESDAY AND WEDNESDAY...CHC TSRA.
ALLSOPP
&&
.MARINE...
147 AM CDT
EARLY THURSDAY MORNING AN ELONGATED AREA OF LOW PRESSURE WAS FROM
THE EASTERN GREAT LAKES BACK TO NORTHERN ILLINOIS...WHILE A STRONG
AREA OF HIGH PRESSURE WAS CENTERED OVER NORTHERN MANITOBA WITH A
RIDGE EXTENDING SOUTHWARD INTO THE NORTHERN PLAINS. AS THE TROF
SWINGS EAST AND THE RIDGE BUILDS INTO THE WESTERN GREAT LAKES
TODAY...GALE FORCE NORTH WINDS WILL DEVELOP OVER LAKE MICHIGAN.
THE GALES WILL DEVELOP OVER CENTRAL LAKE MICHIGAN EARLY THIS
MORNING AND SPREAD TO THE SOUTH END BY MID OR LATE MORNING. WINDS
WILL DIMINISH OVERNIGHT AS THE HIGH SETTLES OVER THE WESTERN GREAT
LAKES AND THE LOW MOVES UP THE EAST COAST. THE HIGH WILL THEN BE
NEARLY STATIONARY OVER THE GREAT LAKES THROUGH THE WEEKEND WITH
LIGHT EAST TO SOUTHEAST FLOW OVER THE LAKE. LOW PRESSURE WILL MOVE
FROM THE CENTRAL PLAINS TO THE UPPER MISSISSIPPI VALLEY MONDAY AND
TUESDAY WHICH WILL CAUSE WINDS TO BECOME SOUTHERLY OVER LAKE
MICHIGAN.
ALLSOPP
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ872-LMZ874-LMZ876-
LMZ878 UNTIL 9 PM THURSDAY.
GALE WARNING...LMZ366-LMZ565-LMZ567-LMZ669-LMZ868-LMZ870 UNTIL 3
PM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
907 AM CDT THU MAY 23 2013
.DISCUSSION...
240 AM CDT
TODAY...
FORECAST CHALLENGES FOR TODAY RESIDE WITH HIGH TEMPS...AND PRECIP
CHANCES THIS MORNING.
IR IMAGERY EARLY THIS MORNING SHOWS CONSIDERABLE CLOUD COVER
REMAINING ACROSS THE WESTERN GREAT LAKES...EXTENDING SOUTH THROUGH
THE MID-MISSISSIPPI VALLEY. ALONG THE WESTERN PERIPHERY OF THE CLOUD
COVER LIES THE LEADING EDGE OF THE STRONG SFC RIDGE...BEGINNING TO
PUSH INTO THE UPPER MIDWEST/NORTHERN PLAINS. MOISTURE HAS BEEN
CONSISTENTLY PEELING OFF TO THE NORTHEAST...NOTED IN THE STEADILY
LOWERING DEW POINTS. DEW POINTS ACROSS CENTRAL WISC HAVE ALREADY
FALLEN INTO THE UPR 40S...AND EXPECT THIS TREND TO EVENTUALLY ARRIVE
ACROSS NORTHERN IL/NORTHWEST IN. A BROAD SFC TROUGH WAS ANALYZED
ACROSS NORTHEAST IL STRETCHING INTO SOUTHCENTRAL LOWER MI. AS A
RESULT SFC WINDS ACROSS THE CWFA HAVE MAINLY BEEN FROM THE
WEST/SOUTHWEST...HOWEVER JUST NORTH OF THE CWFA INTO WISC WINDS HAVE
ALREADY SHIFTED TO THE NORTHWEST/NORTH. LOCATIONS ADJACENT TO LAKE
MICHIGAN WILL SEE WINDS FLOP OVER TO THE NORTHEAST THIS
MORNING...ALLOWING THE MUCH COOLER MARINE ENVIRONMENT TO READILY
FLOW ACROSS THE LAND.
REGIONAL RADAR EARLY THIS MORNING SHOWS AN AREA OF SHOWERS ACROSS
CENTRAL WISC...SLOWLY SLIDING SOUTHEAST. HI-RES GUIDANCE SUGGESTS
THIS CHANNEL OF PRECIP WILL EVENTUALLY ARRIVE ACROSS NORTHERN IL
JUST BEFORE DAYBREAK. AS A RESULT OF THE INCREASED CONFIDENCE IN
PRECIP...HAVE NUDGED THE 12-15Z TIMEFRAME TO LIKELY POPS FOR FAR
NORTHEAST IL.
DRY AIR CONTINUES TO POUR INTO THE REGION MID-MORNING...AND SHOULD
BRING AN END TO THE PRECIP FROM NORTHWEST TO SOUTHEAST ACROSS THE
CWFA BY EARLY THIS AFTERNOON. THE STEADY PUSH OF DRY AIR WILL ALSO
AID IN ERODING THE CLOUD COVER...AND BY LATE THIS AFTERNOON EXPECT
MOSTLY SUNNY SKIES TO DEVELOP. COLD AIR ADVECTION WILL DOMINATE THE
DAY...COUPLED PRECIP AND CLOUDS...EXPECT MUCH COOLER TEMPS FOR THIS
AFTERNOON. GUIDANCE HAS CONTINUED TO SUGGEST TEMPS WILL STRUGGLE TO
WARM BEYOND THE LOW 60S FOR THE FAR WESTERN CWFA...MEANWHILE FURTHER
EAST TEMPS WILL ONLY WARM A FEW DEGREES FROM THEIR STARTING POINT.
THIS WILL MOST LIKELY LEAD TO AREAS EAST OF I-39 ONLY WARMING INTO
THE MID/UPR 50S. LOCATIONS IMMEDIATELY ADJACENT TO LAKE MICHIGAN
COULD SEE TEMPS STRUGGLE TO WARM BEYOND 50 DEGREES.
CONFIDENCE IN PRECIP ENDING TIME...MEDIUM/HIGH.
CONFIDENCE IN TEMPERATURES...HIGH.
TONIGHT...
ANTI-CYCLONIC FLOW WILL CONTINUE TO BUILD OVERHEAD EARLY THIS
EVENING...AND ERODE ANY LINGERING CLOUDS BY MIDNIGHT. DEW POINTS AS
A RESULT WILL CONTINUE TO DRY...BOTTOMING OUT IN THE MID 30S IN MANY
LOCATIONS. THE COMBINATION OF NEAR CLOUDLESS SKIES...LIGHT NORTH TO
AT TIMES CALM WINDS...AND RECENT RAINFALL...WILL SET THE STAGE FOR
NOT ONLY STRONG RADIATIONAL COOLING BUT PATCHY FROST AWAY FROM LAKE
MICHIGAN. GUIDANCE CONTINUES TO PROG TEMPS FALLING OVERNIGHT INTO
THE MID/UPR 30S FOR AREAS WEST OF WAUKEGAN TO KANKAKEE. FAR SOUTHERN
PORTIONS OF THE CWFA SHOULD HAVE TEMPS HOLD ARND 40 DEGREES
OVERNIGHT...HOWEVER A FEW LOW-LYING AREAS COULD SEE SPOTTY FROST. AT
THIS POINT IT DOES NOT APPEAR TO BE A WIDESPREAD FROST SETUP...SO
WILL HOLD OFF ON ANY HEADLINES AT THIS POINT.
CONFIDENCE...HIGH.
FRIDAY...
SFC HIGH PRESSURE WILL DOMINATE THE REGION FOR THE END OF THE
WEEK...AND MORE THAN LIKELY ONLY ALLOW A FEW DIURNAL CLOUDS TO
DEVELOP. A LIGHT NORTHEAST FLOW OFF OF LAKE MICHIGAN WILL CONTINUE
TO KEEP ADJACENT AREAS MUCH COOLER IN THE MID/UPR 50S...MEANWHILE
INLAND LOCATIONS WILL BEGIN TO WARM INTO THE LOW/MID 60S.
WITH HIGH PRESSURE STILL IN CONTROL FRIDAY NIGHT...EXPECT ANOTHER
NIGHT OF STRONG RADIATIONAL COOLING. THE ONLY DIFFERENCE FOR FRI
NIGHT WILL BE THE RIDGE AXIS WILL HAVE SHIFTED EAST. THIS WILL ALLOW
THE LIGHT WINDS TO BEGIN TURNING SOUTHEASTERLY AFTER MIDNIGHT...AND
COULD SLOW THE RATE OF COOLING. HAVE MAINTAINED TEMPS IN THE LOW 40S
FOR MANY AREAS. COULD SEE A FEW OF THE TRADITIONAL COOL SPOTS DIP TO
THE UPR 30S EARLY SAT MORNING...HOWEVER AT THIS POINT NOT
ANTICIPATING FROST FORMATION.
CONFIDENCE IN TEMPERATURES...HIGH.
SATURDAY...
DISCREPANCIES BEGIN TO EMERGE AMONGST SOLUTIONS FOR SAT...WITH
RESPECT TO PLACEMENT/TIMING OF A MOIST BOUNDARY. GFS HAS CONTINUED
TO BE THE MORE PROGRESSIVE SOLUTION...BRINGING THIS CHANNEL OF
MOISTURE/PRECIP INTO THE REGION AND STRETCHES FROM THE NORTHERN
PLAINS SOUTHEAST THROUGH THE OHIO VALLEY. MEANWHILE THE EC HAS
MAINTAINED THE SFC RIDGE...AND SUPPRESSING THE MOIST CHANNEL TO THE
SOUTHWEST OF THE CWFA.
THE LARGEST WEATHER PLAYER IS THE DOWNSTREAM 500MB RIDGE LOCATED
ACROSS THE WESTERN ATLANTIC. THIS WILL ACT AS A BLOCK...SLOWING THE
DEPARTURE OF THE MID-LVL TROUGH ACROSS THE MID-ATLANTIC REGION. THEN
FURTHER UPSTREAM YET ANOTHER 500MB RIDGE WAS PROGGED TO ARRIVE
ACROSS THE CENTRAL CONUS...AND DOES SHOW SOME SIGNS OF
AMPLIFICATION. BASED ON THIS SETUP IT IS BECOMING MORE EVIDENT THAT
SAT COULD END UP BEING DRY...AND POSSIBLY EXTEND INTO SUN. AT THIS
POINT HAVE ONLY ADJUSTED POPS SAT MARGINALLY...TO SLIGHT CHANCE
WORDING.
SFC TEMPS WILL REMAIN UNSEASONABLY COOL IN THE LOW/MID 60S...WITH
AREAS ADJACENT TO LAKE MICHIGAN BEING EVEN COOLER THAN THIS. DESPITE
THE EXPECTED SOUTHEAST COMPONENT TO THE SFC WINDS...ENOUGH HEATING
COULD ALLOW A LAKE BREEZE TO FORM AND ALLOW WINDS TO BECOME MORE
EASTERLY FOR LOCATIONS ADJACENT TO LAKE MICHIGAN. THIS WILL MOST
LIKELY RESULT IN THOSE AREAS IMMEDIATELY NEXT TO THE LAKE REMAINING
IN THE 50S SAT AFTN.
CONFIDENCE...MEDIUM.
SUNDAY THROUGH WEDNESDAY...
FOR THE EXTENDED PERIODS GUIDANCE HAS CONTINUED TO DEMONSTRATE
MINIMAL CHANGES FROM PREVIOUS SOLUTIONS...HOWEVER OPERATIONAL
ECMWF/GFS CONTINUE TO DIFFER ON THE PLACEMENT/TIMING OF PRECIP. THE
ECMWF CONTINUES TO SUGGEST THE SFC RIDGE FROM LATE IN THE WEEK WILL
HOLD TOUGH AND KEEP NORTHERN IL/NORTHWEST IN DRY THRU THE WEEKEND
AND INTO EARLY NEXT WEEK. MEANWHILE THE GFS IS STILL MORE
PROGRESSIVE AND BRINGS THE BOUNDARY OVERHEAD AND BECOMES
QUASI-STATIONARY THRU THE FIRST HALF OF NEXT WEEK.
ENSEMBLES CONTINUE TO INDICATE THE WESTERN ATLANTIC MID-LVL RIDGE
WILL WEAKEN...ALLOWING THE 500MB TROUGH TO FINALLY EJECT EAST. IN
ADDITION THE UPSTREAM RIDGE WILL BEGIN TO FLATTEN...LEADING TO A
SOMEWHAT PROGRESSIVE FLOW OF SYSTEMS FROM WEST TO EAST TOWARDS THE
MIDDLE OF NEXT WEEK. THUS PRECIP CHC WILL BE ON THE INCREASE TOWARDS
THE FINAL FEW PERIODS OF THE CURRENT EXTENDED FORECAST.
BY TUE/WED OF NEXT WEEK...TEMPS COULD EASILY BE BACK INTO THE UPR
70S TO LOW 80S.
CONFIDENCE IN PRECIPITATION...LOW.
CONFIDENCE IN TEMPERATURES...HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* VARIABLE MVFR/IFR CIG SLOWLY IMPROVING AOA 1500 FT AROUND 17Z.
VFR/CLEARING BY MID AFTN.
* NORTH WIND INCREASING TO 20 TO 30 KT BY MID MORNING AND
CONTINUING THROUGH AFTN.
ALLSOPP/BMD
//DISCUSSION...UPDATED 12Z...
MAIN CONCERN THIS MORNING IS CIG TRENDS...THEN THIS AFTERNOON
FOCUS WILL BE ON STRONG GUSTY NNE WINDS. LOW PRESSURE WAS OVER
THE EASTERN GREAT LAKES WITH A COLD FRONT TRAILING WESTWARD INTO
NORTHERN IL. AT 11Z THE FRONT WAS FROM ABOUT IKK-VYS. BASED ON
NAM AND HRRR MODEL SOUNDINGS...CIGS SHOULD SLOWLY IMPROVE TO
AROUND 1000-1200 FT IN THE NEXT COUPLE HOURS. THIS SEEMS
REASONABLE WITH STRONGER WINDS MIXING COLDER AND SLIGHTLY DRIER
AIR DOWN FROM THE NORTH. ALSO SPOTTY LIGHT RAIN/DRIZZLE WILL BE
DIMINISHING/MOVING OUT AND THAT MAY ALSO HELP IMPROVE CIG AND VSBY
A BIT THIS MORNING. AS OF 11Z THE BACK EDGE OF THE MAIN BAND OF
RAIN ASSOCIATED WITH THE COLD FRONT WAS LINED UP FROM DKB-DPA-
MDW-GYY AND SINKING VERY SLOWLY S. THERE WERE SOME VSBY
RESTRICTIONS DOWN TO 2-3 MILES IN THIS BAND OF RAIN...BUT IT HAS
PUSHED SOUTH OF THE TERMINALS. FURTHER NORTH INTO SOUTHERN WI
THERE WERE SOME PATCHES OF LIGHT RAIN/DRIZZLE..BUT THIS WAS VERY
LIGHT. SHORT RANGE/HI RES MODELS SUGGEST THIS SPOTTY LIGHT RAIN
WILL BE DRYING UP AND MOVING SE OUT OF THE AREA BY MID TO LATE
MORNING. THEREFORE DONT EXPECT ANY SIGNIFICANT VSBY RESTRICTIONS
BELOW 5 OR 6 MILES THE REST OF THE MORNING. AS STRONG NORTH WINDS
CONTINUE TO PUSH COLDER DRIER AIR DOWN...EXPECT CLOUDS TO LIFT TO
1500 FT OR BETTER BY NOON AND BREAK UP THIS AFTERNOON WITH
CLEARING MID TO LATE AFTN.
NORTH WINDS HAVE PICKED UP AND WINDS WILL CONTINUE TO INCREASE TO
20 TO 30 KT BY MID MORNING. DIRECTION MAY VARY SOME FROM 350-030
BUT WILL BE PREDOMINANTLY JUST E OF N TODAY. PRESSURE GRADIENT
SLOWLY BEGINS TO RELAX LATE THIS AFTERNOON AND WINDS MAY DIMINISH
SLIGHTLY DURING THE LATE AFTN. ATMOSPHERE SHOULD BEGIN TO DECOUPLE
THIS EVENING AS PRESSURE GRADIENT CONTINUES TO RELAX.
OUTLOOK FOR FRIDAY IS VFR WITH LIGHT NORTHEAST WINDS.
ALLSOPP
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* LOW/MEDIUM CONFIDENCE IN CIG TRENDS THIS MORNING.
* MEDIUM CONFIDENCE IN TIMING OF CLEARING THIS AFTN.
* HIGH CONFIDENCE IN WIND FORECAST. DIRECTION MAY VARY FROM
350-030 BUT SHOULD STAY JUST E OF N.
ALLSOPP
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT AND SATURDAY...VFR. WX NIL.
SUNDAY AND MONDAY...VFR. CHC SHRA SLIGHT CHC TSRA.
TUESDAY AND WEDNESDAY...CHC TSRA.
ALLSOPP
&&
.MARINE...
147 AM CDT
EARLY THURSDAY MORNING AN ELONGATED AREA OF LOW PRESSURE WAS FROM
THE EASTERN GREAT LAKES BACK TO NORTHERN ILLINOIS...WHILE A STRONG
AREA OF HIGH PRESSURE WAS CENTERED OVER NORTHERN MANITOBA WITH A
RIDGE EXTENDING SOUTHWARD INTO THE NORTHERN PLAINS. AS THE TROF
SWINGS EAST AND THE RIDGE BUILDS INTO THE WESTERN GREAT LAKES
TODAY...GALE FORCE NORTH WINDS WILL DEVELOP OVER LAKE MICHIGAN.
THE GALES WILL DEVELOP OVER CENTRAL LAKE MICHIGAN EARLY THIS
MORNING AND SPREAD TO THE SOUTH END BY MID OR LATE MORNING. WINDS
WILL DIMINISH OVERNIGHT AS THE HIGH SETTLES OVER THE WESTERN GREAT
LAKES AND THE LOW MOVES UP THE EAST COAST. THE HIGH WILL THEN BE
NEARLY STATIONARY OVER THE GREAT LAKES THROUGH THE WEEKEND WITH
LIGHT EAST TO SOUTHEAST FLOW OVER THE LAKE. LOW PRESSURE WILL MOVE
FROM THE CENTRAL PLAINS TO THE UPPER MISSISSIPPI VALLEY MONDAY AND
TUESDAY WHICH WILL CAUSE WINDS TO BECOME SOUTHERLY OVER LAKE
MICHIGAN.
ALLSOPP
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ872-LMZ874-LMZ876-
LMZ878 UNTIL 9 PM THURSDAY.
GALE WARNING...LMZ366-LMZ565-LMZ567-LMZ669-LMZ868-LMZ870 UNTIL 3
PM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
648 AM CDT THU MAY 23 2013
.DISCUSSION...
240 AM CDT
TODAY...
FORECAST CHALLENGES FOR TODAY RESIDE WITH HIGH TEMPS...AND PRECIP
CHANCES THIS MORNING.
IR IMAGERY EARLY THIS MORNING SHOWS CONSIDERABLE CLOUD COVER
REMAINING ACROSS THE WESTERN GREAT LAKES...EXTENDING SOUTH THROUGH
THE MID-MISSISSIPPI VALLEY. ALONG THE WESTERN PERIPHERY OF THE CLOUD
COVER LIES THE LEADING EDGE OF THE STRONG SFC RIDGE...BEGINNING TO
PUSH INTO THE UPPER MIDWEST/NORTHERN PLAINS. MOISTURE HAS BEEN
CONSISTENTLY PEELING OFF TO THE NORTHEAST...NOTED IN THE STEADILY
LOWERING DEW POINTS. DEW POINTS ACROSS CENTRAL WISC HAVE ALREADY
FALLEN INTO THE UPR 40S...AND EXPECT THIS TREND TO EVENTUALLY ARRIVE
ACROSS NORTHERN IL/NORTHWEST IN. A BROAD SFC TROUGH WAS ANALYZED
ACROSS NORTHEAST IL STRETCHING INTO SOUTHCENTRAL LOWER MI. AS A
RESULT SFC WINDS ACROSS THE CWFA HAVE MAINLY BEEN FROM THE
WEST/SOUTHWEST...HOWEVER JUST NORTH OF THE CWFA INTO WISC WINDS HAVE
ALREADY SHIFTED TO THE NORTHWEST/NORTH. LOCATIONS ADJACENT TO LAKE
MICHIGAN WILL SEE WINDS FLOP OVER TO THE NORTHEAST THIS
MORNING...ALLOWING THE MUCH COOLER MARINE ENVIRONMENT TO READILY
FLOW ACROSS THE LAND.
REGIONAL RADAR EARLY THIS MORNING SHOWS AN AREA OF SHOWERS ACROSS
CENTRAL WISC...SLOWLY SLIDING SOUTHEAST. HI-RES GUIDANCE SUGGESTS
THIS CHANNEL OF PRECIP WILL EVENTUALLY ARRIVE ACROSS NORTHERN IL
JUST BEFORE DAYBREAK. AS A RESULT OF THE INCREASED CONFIDENCE IN
PRECIP...HAVE NUDGED THE 12-15Z TIMEFRAME TO LIKELY POPS FOR FAR
NORTHEAST IL.
DRY AIR CONTINUES TO POUR INTO THE REGION MID-MORNING...AND SHOULD
BRING AN END TO THE PRECIP FROM NORTHWEST TO SOUTHEAST ACROSS THE
CWFA BY EARLY THIS AFTERNOON. THE STEADY PUSH OF DRY AIR WILL ALSO
AID IN ERODING THE CLOUD COVER...AND BY LATE THIS AFTERNOON EXPECT
MOSTLY SUNNY SKIES TO DEVELOP. COLD AIR ADVECTION WILL DOMINATE THE
DAY...COUPLED PRECIP AND CLOUDS...EXPECT MUCH COOLER TEMPS FOR THIS
AFTERNOON. GUIDANCE HAS CONTINUED TO SUGGEST TEMPS WILL STRUGGLE TO
WARM BEYOND THE LOW 60S FOR THE FAR WESTERN CWFA...MEANWHILE FURTHER
EAST TEMPS WILL ONLY WARM A FEW DEGREES FROM THEIR STARTING POINT.
THIS WILL MOST LIKELY LEAD TO AREAS EAST OF I-39 ONLY WARMING INTO
THE MID/UPR 50S. LOCATIONS IMMEDIATELY ADJACENT TO LAKE MICHIGAN
COULD SEE TEMPS STRUGGLE TO WARM BEYOND 50 DEGREES.
CONFIDENCE IN PRECIP ENDING TIME...MEDIUM/HIGH.
CONFIDENCE IN TEMPERATURES...HIGH.
TONIGHT...
ANTI-CYCLONIC FLOW WILL CONTINUE TO BUILD OVERHEAD EARLY THIS
EVENING...AND ERODE ANY LINGERING CLOUDS BY MIDNIGHT. DEW POINTS AS
A RESULT WILL CONTINUE TO DRY...BOTTOMING OUT IN THE MID 30S IN MANY
LOCATIONS. THE COMBINATION OF NEAR CLOUDLESS SKIES...LIGHT NORTH TO
AT TIMES CALM WINDS...AND RECENT RAINFALL...WILL SET THE STAGE FOR
NOT ONLY STRONG RADIATIONAL COOLING BUT PATCHY FROST AWAY FROM LAKE
MICHIGAN. GUIDANCE CONTINUES TO PROG TEMPS FALLING OVERNIGHT INTO
THE MID/UPR 30S FOR AREAS WEST OF WAUKEGAN TO KANKAKEE. FAR SOUTHERN
PORTIONS OF THE CWFA SHOULD HAVE TEMPS HOLD ARND 40 DEGREES
OVERNIGHT...HOWEVER A FEW LOW-LYING AREAS COULD SEE SPOTTY FROST. AT
THIS POINT IT DOES NOT APPEAR TO BE A WIDESPREAD FROST SETUP...SO
WILL HOLD OFF ON ANY HEADLINES AT THIS POINT.
CONFIDENCE...HIGH.
FRIDAY...
SFC HIGH PRESSURE WILL DOMINATE THE REGION FOR THE END OF THE
WEEK...AND MORE THAN LIKELY ONLY ALLOW A FEW DIURNAL CLOUDS TO
DEVELOP. A LIGHT NORTHEAST FLOW OFF OF LAKE MICHIGAN WILL CONTINUE
TO KEEP ADJACENT AREAS MUCH COOLER IN THE MID/UPR 50S...MEANWHILE
INLAND LOCATIONS WILL BEGIN TO WARM INTO THE LOW/MID 60S.
WITH HIGH PRESSURE STILL IN CONTROL FRIDAY NIGHT...EXPECT ANOTHER
NIGHT OF STRONG RADIATIONAL COOLING. THE ONLY DIFFERENCE FOR FRI
NIGHT WILL BE THE RIDGE AXIS WILL HAVE SHIFTED EAST. THIS WILL ALLOW
THE LIGHT WINDS TO BEGIN TURNING SOUTHEASTERLY AFTER MIDNIGHT...AND
COULD SLOW THE RATE OF COOLING. HAVE MAINTAINED TEMPS IN THE LOW 40S
FOR MANY AREAS. COULD SEE A FEW OF THE TRADITIONAL COOL SPOTS DIP TO
THE UPR 30S EARLY SAT MORNING...HOWEVER AT THIS POINT NOT
ANTICIPATING FROST FORMATION.
CONFIDENCE IN TEMPERATURES...HIGH.
SATURDAY...
DISCREPANCIES BEGIN TO EMERGE AMONGST SOLUTIONS FOR SAT...WITH
RESPECT TO PLACEMENT/TIMING OF A MOIST BOUNDARY. GFS HAS CONTINUED
TO BE THE MORE PROGRESSIVE SOLUTION...BRINGING THIS CHANNEL OF
MOISTURE/PRECIP INTO THE REGION AND STRETCHES FROM THE NORTHERN
PLAINS SOUTHEAST THROUGH THE OHIO VALLEY. MEANWHILE THE EC HAS
MAINTAINED THE SFC RIDGE...AND SUPPRESSING THE MOIST CHANNEL TO THE
SOUTHWEST OF THE CWFA.
THE LARGEST WEATHER PLAYER IS THE DOWNSTREAM 500MB RIDGE LOCATED
ACROSS THE WESTERN ATLANTIC. THIS WILL ACT AS A BLOCK...SLOWING THE
DEPARTURE OF THE MID-LVL TROUGH ACROSS THE MID-ATLANTIC REGION. THEN
FURTHER UPSTREAM YET ANOTHER 500MB RIDGE WAS PROGGED TO ARRIVE
ACROSS THE CENTRAL CONUS...AND DOES SHOW SOME SIGNS OF
AMPLIFICATION. BASED ON THIS SETUP IT IS BECOMING MORE EVIDENT THAT
SAT COULD END UP BEING DRY...AND POSSIBLY EXTEND INTO SUN. AT THIS
POINT HAVE ONLY ADJUSTED POPS SAT MARGINALLY...TO SLIGHT CHANCE
WORDING.
SFC TEMPS WILL REMAIN UNSEASONABLY COOL IN THE LOW/MID 60S...WITH
AREAS ADJACENT TO LAKE MICHIGAN BEING EVEN COOLER THAN THIS. DESPITE
THE EXPECTED SOUTHEAST COMPONENT TO THE SFC WINDS...ENOUGH HEATING
COULD ALLOW A LAKE BREEZE TO FORM AND ALLOW WINDS TO BECOME MORE
EASTERLY FOR LOCATIONS ADJACENT TO LAKE MICHIGAN. THIS WILL MOST
LIKELY RESULT IN THOSE AREAS IMMEDIATELY NEXT TO THE LAKE REMAINING
IN THE 50S SAT AFTN.
CONFIDENCE...MEDIUM.
SUNDAY THROUGH WEDNESDAY...
FOR THE EXTENDED PERIODS GUIDANCE HAS CONTINUED TO DEMONSTRATE
MINIMAL CHANGES FROM PREVIOUS SOLUTIONS...HOWEVER OPERATIONAL
ECMWF/GFS CONTINUE TO DIFFER ON THE PLACEMENT/TIMING OF PRECIP. THE
ECMWF CONTINUES TO SUGGEST THE SFC RIDGE FROM LATE IN THE WEEK WILL
HOLD TOUGH AND KEEP NORTHERN IL/NORTHWEST IN DRY THRU THE WEEKEND
AND INTO EARLY NEXT WEEK. MEANWHILE THE GFS IS STILL MORE
PROGRESSIVE AND BRINGS THE BOUNDARY OVERHEAD AND BECOMES
QUASI-STATIONARY THRU THE FIRST HALF OF NEXT WEEK.
ENSEMBLES CONTINUE TO INDICATE THE WESTERN ATLANTIC MID-LVL RIDGE
WILL WEAKEN...ALLOWING THE 500MB TROUGH TO FINALLY EJECT EAST. IN
ADDITION THE UPSTREAM RIDGE WILL BEGIN TO FLATTEN...LEADING TO A
SOMEWHAT PROGRESSIVE FLOW OF SYSTEMS FROM WEST TO EAST TOWARDS THE
MIDDLE OF NEXT WEEK. THUS PRECIP CHC WILL BE ON THE INCREASE TOWARDS
THE FINAL FEW PERIODS OF THE CURRENT EXTENDED FORECAST.
BY TUE/WED OF NEXT WEEK...TEMPS COULD EASILY BE BACK INTO THE UPR
70S TO LOW 80S.
CONFIDENCE IN PRECIPITATION...LOW.
CONFIDENCE IN TEMPERATURES...HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* IFR CIG SLOWLY IMPROVING TO MVFR AROUND 12-14Z...AND AOA 1500 FT
BY NOON. VFR/CLEARING BY MID AFTN.
* NORTH WIND INCREASING TO 20 TO 30 KT BY MID MORNING AND
CONTINUING THROUGH AFTN.
ALLSOPP
//DISCUSSION...UPDATED 12Z...
MAIN CONCERN THIS MORNING IS CIG TRENDS...THEN THIS AFTERNOON
FOCUS WILL BE ON STRONG GUSTY NNE WINDS. LOW PRESSURE WAS OVER
THE EASTERN GREAT LAKES WITH A COLD FRONT TRAILING WESTWARD INTO
NORTHERN IL. AT 11Z THE FRONT WAS FROM ABOUT IKK-VYS. BASED ON
NAM AND HRRR MODEL SOUNDINGS...CIGS SHOULD SLOWLY IMPROVE TO
AROUND 1000-1200 FT IN THE NEXT COUPLE HOURS. THIS SEEMS
REASONABLE WITH STRONGER WINDS MIXING COLDER AND SLIGHTLY DRIER
AIR DOWN FROM THE NORTH. ALSO SPOTTY LIGHT RAIN/DRIZZLE WILL BE
DIMINISHING/MOVING OUT AND THAT MAY ALSO HELP IMPROVE CIG AND VSBY
A BIT THIS MORNING. AS OF 11Z THE BACK EDGE OF THE MAIN BAND OF
RAIN ASSOCIATED WITH THE COLD FRONT WAS LINED UP FROM DKB-DPA-
MDW-GYY AND SINKING VERY SLOWLY S. THERE WERE SOME VSBY
RESTRICTIONS DOWN TO 2-3 MILES IN THIS BAND OF RAIN...BUT IT HAS
PUSHED SOUTH OF THE TERMINALS. FURTHER NORTH INTO SOUTHERN WI
THERE WERE SOME PATCHES OF LIGHT RAIN/DRIZZLE..BUT THIS WAS VERY
LIGHT. SHORT RANGE/HI RES MODELS SUGGEST THIS SPOTTY LIGHT RAIN
WILL BE DRYING UP AND MOVING SE OUT OF THE AREA BY MID TO LATE
MORNING. THEREFORE DONT EXPECT ANY SIGNIFICANT VSBY RESTRICTIONS
BELOW 5 OR 6 MILES THE REST OF THE MORNING. AS STRONG NORTH WINDS
CONTINUE TO PUSH COLDER DRIER AIR DOWN...EXPECT CLOUDS TO LIFT TO
1500 FT OR BETTER BY NOON AND BREAK UP THIS AFTERNOON WITH
CLEARING MID TO LATE AFTN.
NORTH WINDS HAVE PICKED UP AND WINDS WILL CONTINUE TO INCREASE TO
20 TO 30 KT BY MID MORNING. DIRECTION MAY VARY SOME FROM 350-030
BUT WILL BE PREDOMINANTLY JUST E OF N TODAY. PRESSURE GRADIENT
SLOWLY BEGINS TO RELAX LATE THIS AFTERNOON AND WINDS MAY DIMINISH
SLIGHTLY DURING THE LATE AFTN. ATMOSPHERE SHOULD BEGIN TO DECOUPLE
THIS EVENING AS PRESSURE GRADIENT CONTINUES TO RELAX.
OUTLOOK FOR FRIDAY IS VFR WITH LIGHT NORTHEAST WINDS.
ALLSOPP
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM CONFIDENCE IN CIG TRENDS THIS MORNING.
* MEDIUM CONFIDENCE IN TIMING OF CLEARING THIS AFTN.
* HIGH CONFIDENCE IN WIND FORECAST. DIRECTION MAY VARY FROM
350-030 BUT SHOULD STAY JUST E OF N.
ALLSOPP
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT AND SATURDAY...VFR. WX NIL.
SUNDAY AND MONDAY...VFR. CHC SHRA SLIGHT CHC TSRA.
TUESDAY AND WEDNESDAY...CHC TSRA.
ALLSOPP
&&
.MARINE...
147 AM CDT
EARLY THURSDAY MORNING AN ELONGATED AREA OF LOW PRESSURE WAS FROM
THE EASTERN GREAT LAKES BACK TO NORTHERN ILLINOIS...WHILE A STRONG
AREA OF HIGH PRESSURE WAS CENTERED OVER NORTHERN MANITOBA WITH A
RIDGE EXTENDING SOUTHWARD INTO THE NORTHERN PLAINS. AS THE TROF
SWINGS EAST AND THE RIDGE BUILDS INTO THE WESTERN GREAT LAKES
TODAY...GALE FORCE NORTH WINDS WILL DEVELOP OVER LAKE MICHIGAN.
THE GALES WILL DEVELOP OVER CENTRAL LAKE MICHIGAN EARLY THIS
MORNING AND SPREAD TO THE SOUTH END BY MID OR LATE MORNING. WINDS
WILL DIMINISH OVERNIGHT AS THE HIGH SETTLES OVER THE WESTERN GREAT
LAKES AND THE LOW MOVES UP THE EAST COAST. THE HIGH WILL THEN BE
NEARLY STATIONARY OVER THE GREAT LAKES THROUGH THE WEEKEND WITH
LIGHT EAST TO SOUTHEAST FLOW OVER THE LAKE. LOW PRESSURE WILL MOVE
FROM THE CENTRAL PLAINS TO THE UPPER MISSISSIPPI VALLEY MONDAY AND
TUESDAY WHICH WILL CAUSE WINDS TO BECOME SOUTHERLY OVER LAKE
MICHIGAN.
ALLSOPP
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ872-LMZ874-LMZ876-
LMZ878 UNTIL 9 PM THURSDAY.
GALE WARNING...LMZ366-LMZ565-LMZ567-LMZ669-LMZ868-LMZ870 UNTIL 3
PM THURSDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS TOPEKA KS
312 AM CDT THU MAY 23 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 230 AM CDT THU MAY 23 2013
THE OLD UPPER SYSTEM CONTINUES TO SLIDE EAST AND WEAKEN OVER THE
WESTERN GREAT LAKES...WITH 0Z 500MB HEIGHT CHANGE OBSERVATIONS
DEPICTING WEAK TO MODERATE RISES ACROSS THE PLAINS. LOW LEVEL
RIDGING WAS TAKING SHAPE ACROSS THE CENTRAL PLAINS...WITH SOUTH
WINDS TAKING HOLD OVER THE SOUTHERN HIGH PLAINS. A SHRINKING STRATUS
DECK WAS OOZING SOUTH THROUGH NEBRASKA EARLY THIS MORNING.
SHALLOW NATURE TO THE LOW CLOUDS AND INCREASING LOW LEVEL ISENTROPIC
DOWNGLIDE SHOULD ALLOW THE INVADING STRATUS TO DISSIPATE THIS
MORNING THOUGH MORE COULD REDEVELOP WITH DAYTIME HEATING. TEMPS
AGAIN STAY ON THE COOL SIDE WITH NORTH WINDS VEERING TO THE EAST
THROUGH THE DAY. FURTHER VEERING ON TRACK FOR TONIGHT AS LEE LOW
PRESSURE BEGINS TO TAKE SHAPE AND UPPER HEIGHTS CONTINUE TO RISE.
MID LEVEL MOISTURE INCREASES A BIT IN THE WEST WITH MODEST
ISENTROPIC UPGLIDE VIA WEAK WINDS AND ELEVATED CAPE DEVELOPING. THIS
COULD BE ENOUGH TO USHER ANY HIGH PLAINS CONVECTION INTO NORTH
CENTRAL KANSAS LATE TONIGHT...THOUGH CONFIDENCE IN THE FORMER MAKING
IT THIS FAR NORTH IS NOT VERY HIGH.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 230 AM CDT THU MAY 23 2013
DESPITE THE FACT THAT THERE ARE CHANCES FOR PRECIPITATION THROUGH
THE FORECAST FOR FRIDAY THROUGH NEXT WEDNESDAY...REST ASSURED IT
WONT BE RAINING ALL DAY EVERY DAY. CONVECTION IS BEING DRIVEN BY
SMALL WAVES IN THE FLOW THAT ARE DIFFICULT TO TIME...BY THE
NOCTURNAL LLJ...AS WELL AS THE BOUNDARIES THAT THE CONVECTION
LEAVES BEHIND TO REGENERATE CHANCES FOR THE FOLLOWING DAY...AND
OTHER MESOSCALE INTERACTIONS RELATED TO ALL THESE FEATURES. WILL
LIKELY BE ABLE TO TIME PRECIPITATION CHANCES BETTER IN A WINDOW
CLOSER TO THEIR TIME SCALES...BY A MATTER OF A DAY OR TWO RATHER
THAN SEVERAL DAYS OUT.
FIRST FEATURE IS A FRONTAL BOUNDARY DRAPED N/S FROM THE DAKOTAS
INTO NEBRASKA...THE SOUTHERN EDGE OF WHICH CLIPS ACROSS THE
FORECAST AREA THROUGH THE DAY ON FRIDAY. THE FOLLOWING NIGHT LLJ
SLIDES CONVECTION ALONG THE NORTH AND TO THE NE OF THE CWA AND MAY
RUN THROUGH OUR NORTHERN COUNTIES. BOUNDARY FROM THIS MCS COULD THEN
LAY UP ACROSS THE AREA ON SATURDAY AFTERNOON AND REGENERATE
STORMS...WITH YET ANOTHER WEAK WAVE RIDING ACROSS WRN/CTRL KS AND
BRINGING ANOTHER CHANCE FOR TS SATURDAY NIGHT INTO SUNDAY MORNING.
MAY CATCH A BREAK BETWEEN WAVES ON SUNDAY AFTERNOON BEFORE
POTENTIAL FOR ANOTHER WAVE TO LIFT ACROSS THE WRN THRU NORTHERN
COUNTIES INTO MONDAY. SOME SUGGESTION THAT RIDGE AMPLIFIES TUESDAY
INTO WEDNESDAY IN THE ECMWF...ALTHOUGH GFS AMPLIFIES IT FARTHER TO
THE EAST OF OUR FA AND KEEPS THE DAMP PATTERN GOING FOR ANOTHER
DAY. AFTER A COOLER DAY IN THE 70S ON FRIDAY...AS SFC RIDGE SHIFTS
EAST AND WAA RETURNS...SHOULD SE A SHIFT BACK TOWARD THE LOWER 80S
FOR HIGHS ACROSS THE AREA. IF THE RIDGE CAN AMPLIFY...MAY SEE
WARMER TEMPS TOWARD LATER NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1122 PM CDT WED MAY 22 2013
THE RAP AND NAM CONTINUE TO SHOW THE POTENTIAL FOR MVFR CIGS
MOVING IN FROM THE NORTH BY 12Z. THEREFORE FORECAST THINKING IS
UNCHANGED. CIGS SHOULD GRADUALLY IMPROVE BY NOON WITH THE
POTENTIAL FOR A STRATOCU DECK PERSISTING THROUGH A GOOD PORTION OF
THE DAY. SFC WINDS WILL GRADUALLY VEER WITH RIDGING NOSING IN.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...67
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
104 AM CDT THU MAY 23 2013
...AVIATION SECTION UPDATED FOR 06Z TAFS...
.SYNOPSIS...
ISSUED AT 340 PM CDT WED MAY 22 2013
THE 12Z UPPER AIR ANALYSIS SHOWED THE REMAINS OF THE NORTHERN PLAINS
CLOSED LOW WEAKENING OVER SOUTHERN MINNESOTA AS IT IS GETTING PHASED
WITH A STRONG SHORTWAVE TROUGH OVER HUDSON`S BAY. A DEEP CLOSED LOW
WAS OVER THE PACIFIC NORTHWEST. IN BETWEEN THESE FEATURES, WEAK
UPPER LEVEL RIDGING EXTENDED FROM CENTRAL CANADA SOUTHWARD ALONG THE
EASTERN SLOPES OF THE ROCKIES AND ADJACENT HIGH PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 340 PM CDT WED MAY 22 2013
THE UPPER LOW WILL CONTINUE TO FILL AS IT MOVES INTO THE GREAT
LAKES ON THURSDAY. AS IT MOVES OUT, A SHORTWAVE TROUGH WILL ROTATE
AROUND THE WEST PART OF THE UPPER LOW, WHICH WILL HELP PUSH A COLD
FRONT SOUTH INTO THE CENTRAL HIGH PLAINS TONIGHT. A WEAK DISTURBANCE
WAS EVIDENT IN THE WATER VAPOR IMAGERY MOVING OUT OF THE FOUR
CORNERS REGION THIS AFTERNOON. THE MODELS ARE NOT PICKING UP ON
THIS FEATURE VERY WELL. THEY DO SHOW SOME WARM AIR ADVECTION
DEVELOPING AHEAD OF IT OVER WESTERN KANSAS TONIGHT ALONG WITH SOME
VERY WEAK ELEVATED INSTABILITY ATOP THE COLD FRONT AND LOW LEVEL
COLD ADVECTION THAT WILL BE MOVING INTO WESTERN KANSAS THIS EVENING.
THE HRRR IS STARTING TO SHOW CONVECTION DEVELOPING OVER EASTERN
COLORADO THIS EVENING WORKING INTO WESTERN KANSAS OVERNIGHT. LOW
STRATUS IS ALSO EXPECTED TO DEVELOP BEHIND THE FRONT TONIGHT.
ON THURSDAY, SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS WILL MOVE
INTO CENTRAL KANSAS WHERE THE BEST, ALBEIT WEAK, ELEVATED INSTABILITY
WILL BE. AREAS FARTHER WEST WILL BE CLOUDY TO MOSTLY CLOUDY BUT
STABLE ALOFT. HIGH TEMPERATURES WILL STRUGGLE INTO THE LOW 70S IN
MOST AREAS GIVEN THE CLOUD COVER. AREAS ALONG THE OKLAHOMA BORDER
COULD REACH THE LOW/MID 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 348 PM CDT WED MAY 22 2013
LOW LEVEL MOISTURE WILL SURGE BACK TO THE NORTHWEST INTO THE
SOUTHERN PLAINS BY LATE THURSDAY AS UPPER LEVEL TROUGHING DEVELOPS
ACROSS THE WESTERN UNITED STATES. SURGE HIGH PRESSURE WILL SLIDE
SOUTHEASTWARD INTO THE MIDWEST. A WARM ADVECTION PATTERN WILL
STRENGTHEN THURSDAY NIGHT AND SOME ELEVATED THUNDERSTORM ACTIVITY
IS POSSIBLE. THE UPPER LEVEL RIDGE AXIS BETWEEN THE WESTERN AND
EASTERN UNITED STATES TROUGHS WILL BE OVER THE CENTRAL PLAINS BY
FRIDAY. BUT SOME MID LEVEL FLOW COMING THROUGH THE RIDGE WILL
ALLOW FOR LEE TROUGHING AND A SURGE OF MOISTURE FROM THE SOUTHERN
PLAINS INTO KANSAS. WESTERN KANSAS WILL BE ON THE SOUTHERN EDGE OF
THE WESTERLIES AND THE UPPER LEVEL WINDS WILL NOT BE THAT
IMPRESSIVE. HOWEVER, WITH 2000-3000 J/KG CAPE AND STRONG
DIRECTIONAL TURNING, A FEW SEVERE THUNDERSTORMS ARE POSSIBLE,
PARTICULARLY IN FAR SOUTHWEST KANSAS. HIGH TEMPERATURES FRIDAY WILL
RANGE FROM THE UPPER 70S NEAR HAYS TO THE UPPER 80S IN FAR
SOUTHWEST KANSAS CLOSER TO THE LEE TROUGH.
UPPER LEVEL TROUGHING WILL REMAIN ACROSS THE WESTERN UNITED STATES
THROUGH MID NEXT WEEK, ALTHOUGH THERE IS SOME UNCERTAINTY IN HOW
FAR EAST IT WILL PROGRESS. THE ECMWF IS LESS PROGRESSIVE THAN THE
OTHER MODELS AND GENERALLY A LESS PROGRESSIVE SOLUTION IS THE BEST
ONE. FOR SATURDAY INTO MONDAY, MODERATE TO HIGH SURFACE BASED CAPE
WILL BE IN PLACE AHEAD OF A DRYLINE. A FEW THUNDERSTORMS WILL
DEVELOP EACH DAY ALONG THE DRYLINE AND SLOWLY MOVE EASTWARD. THESE
STORMS COULD BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS. THE
UPPER LEVEL WINDS ARE STILL NOT PROGGED TO BE THAT STRONG, SO
TORNADIC STORMS ARE NOT EXPECTED, BUT CANNOT BE RULED OUT GIVEN THE
STRONG INSTABILITY. TEMPERATURES WILL BE FAIRLY WARM THROUGH THE
EXTENDED WITH LOWS IN THE 60S AND HIGHS IN THE 80S AND 90S SINCE
KANSAS WILL BE IN THE WARM SECTOR. THE WARMEST HIGH TEMPERATURES
OUGHT TO BE IN FAR WESTERN KANSAS BEHIND THE DRYLINE AND THE
WARMEST LOWS SHOULD BE IN SOUTH CENTRAL AND CENTRAL KANSAS WHERE
DEWPOINTS AND WINDS WILL BE HIGHEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1257 AM CDT THU MAY 23 2013
A COLD FRONT WILL SLIDE INTO THE HAYS AREA BY 10Z AND INTO GCK AND
DDC BY 12Z. AT THE SAME TIME A WARM FRONT ACROSS WEST AND CENTRAL
TEXAS WILL LIFT NORTH INTO THE TX PANHANDLE DURING THE OVERNIGHT
PERIOD. MOISTENING EASTERLY WINDS HAVE COMMENCED AND WILL BE
REINFORCED BEHIND THE AFOREMENTIONED COLD FRONT. THERE WAS ALREADY
STRATUS BEHIND THE FRONT AND AS THE SURFACE FLOW MOVES WEST INTO
HIGHER TERRAIN STRATUS WILL BEGIN TO FORM SOUTH OF THE FRONT BY
SUNRISE. INITIAL THINKING IS MVFR CEILINGS MAY BE REACHED AT HYS
BY 12Z BUT SHOULD REMAIN HIGHER AT DDC/GCK. I`VE LEFT PCPN OUT OF
THE TERMINALS FOR NOW BUT WILL WATCH FOR ELEVATED DEVELOPMENT
EARLY THIS MORNING AS HIGH RESOLUTION FORECAST MODELS SHOW SOME
ACTIVITY BY SUNRISE AROUND HAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 58 81 63 89 / 40 30 30 30
GCK 58 83 63 91 / 30 40 40 20
EHA 59 88 63 92 / 30 40 30 20
LBL 60 87 64 91 / 30 40 30 20
HYS 56 77 67 89 / 40 40 30 40
P28 59 78 67 86 / 30 40 30 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GERARD
SHORT TERM...GERARD
LONG TERM...FINCH
AVIATION...HUTTON
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1122 PM CDT WED MAY 22 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 354 PM CDT WED MAY 22 2013
THE UPPER LOW ASSOCIATED WITH THIS WEEKEND`S ACTIVE SEVERE WEATHER
WAS SITUATED OVER IOWA THIS AFTERNOON...WITH THE ASSOCIATED SURFACE
LOW PROGRESSING EASTWARD INTO WISCONSIN AND ILLINOIS. CLOUD COVER IN
ASSOCIATION WITH THIS SYSTEM STRETCHED WESTWARD INTO NORTHEAST AND
FAR EASTERN KANSAS THROUGH THE AFTERNOON HOURS...WHICH RESULTED IN
SOMEWHAT COOLER TEMPERATURES ACROSS THE REGION TODAY. WITH THE CLOUD
COVER...AFTERNOON HIGHS PEAKED IN THE MIDDLE TO UPPER 60S. SURFACE
HIGH PRESSURE OVER THE NORTHERN PLAINS WILL HELP TO PUSH THE LOW
PRESSURE SYSTEM EASTWARD TOWARD THE GREAT LAKES REGION AS THE HIGH
SPREADS SOUTHWARD INTO THE CENTRAL PLAINS TONIGHT INTO THURSDAY.
WITH THE EXITING SURFACE LOW...SHOULD START SEEING SOME BREAKS IN THE
CLOUD COVER TONIGHT INTO THE OVERNIGHT HOURS. THIS DIMINISHING CLOUD
COVER WILL ALLOW FOR MORE RADIATIONAL COOLING EARLY THURSDAY MORNING
WITH LOW TEMPERATURES EXPECTED TO BE A FEW DEGREES COOLER THAN
NORMAL...IN THE UPPER 40S TO LOWER 50S.
THE WEAK UPPER LEVEL RIDGE THAT WAS IN PLACE OVER THE CENTRAL
ROCKIES THIS AFTERNOON WILL CONTINUE TO BUILD AS IT PROGRESSES
EASTWARD INTO THE CENTRAL AND SOUTHERN PLAINS BY THURSDAY. MODELS
CONTINUE TO SHOW AN EMBEDDED SHORTWAVE DEVELOPING ALONG THE NORTHERN
EXTENT OF THE RIDGE OVER WESTERN KANSAS AND WESTERN OKLAHOMA...WHICH
MAY BRING SOME SCATTERED SHOWERS AND THUNDERSTORMS TO THAT REGION
THROUGH THE DAY. WHILE THIS ACTIVITY IS EXPECTED TO REMAIN SOUTHWEST
OF THE FORECAST AREA ON THURSDAY...SHOULD STILL HAVE SCATTERED CLOUD
COVER ACROSS MUCH OF THE AREA THROUGH THE DAY. THIS CLOUD COVER
COMBINED WITH NORTHEASTERLY WINDS AROUND THE SURFACE HIGH WILL KEEP
AFTERNOON HIGHS COOLER THAN NORMAL WITH READINGS LIKING PEAKING IN
THE UPPER 60S TO LOWER 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 354 PM CDT WED MAY 22 2013
OVERALL PATTERN WILL FEATURE A FLAT RIDGE WITH INCREASING WAA AND
MOISTURE ADVECTION WHICH WILL SERVE TO PRODUCE SEVERAL BOUTS OF
THUNDERSTORM CHCS. THE INITIAL FORCING IS WEAK THU NIGHT INTO FRI
AND SHOULD STAY FOCUSED ACROSS THE NORTHWEST PARTS OF THE CWA. WILL
KEEP RAIN CHCS LOW AND CONFINED TO AREAS TOPEKA NORTH AND WEST FOR
FRI BUT AGAIN WITHOUT A FOCUS AND GREATER FORCING NOT SURE HOW
WIDESPREAD ANY PRECIP WILL BE FRI.
BY FRI NIGHT INTO SAT THETA-E (MOISTURE AND TEMP ADVECTION) WILL
INCREASE ACROSS KS INTO NEBRASKA. NOSE OF THE 50KT LLJ WILL TARGET
NORTHEAST NEB SO IT WOULD APPEAR THAT THE MAIN COMPLEX OF ANY MCS
WOULD BE LOCATED NORTH OF THE AREA HOWEVER CANNOT RULE OUT SCT
CONVECTION WITHIN THE LLJ AXIS OVERNIGHT INTO EARLY SAT. ANOTHER
WEAK WAVE WILL MOVE ACROSS THE RIDGE SAT NIGHT INTO SUN AND THIS
SHOULD HELP ANOTHER CONVECTIVE COMPLEX DEVELOP ACROSS NE/NORTHERN KS
SO WILL KEEP 20 TO 40 POPS WITH THE HIGHEST ACROSS THE NORTHERN
COUNTIES.
SAME PATTERN WILL PERSIST INTO SUN NIGHT AND MON SO HAVE TO EXPECT
AT LEAST SOME CHCS FOR MAINLY NIGHTTIME THUNDERSTORMS ACROSS THE
AREA SUN NIGHT AND MON AS WEAK WAVES MOVE INTO THE FLATTENING RIDGE
AND COMBINE WITH THE NIGHTTIME LLJ TO FEED OVERNIGHT STORMS.
MON AND BEYOND...IT APPEARS THAT RIDGING SHOULD STRENGTHEN BY TUES
AHEAD OF A DEEPENING TROUGH ACROSS THE WEST. THIS SHOULD LEAD TO
GRADUALLY WARMER TEMPS AND PERHAPS A LULL IN PRECIP CHCS BY MID
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1122 PM CDT WED MAY 22 2013
THE RAP AND NAM CONTINUE TO SHOW THE POTENTIAL FOR MVFR CIGS
MOVING IN FROM THE NORTH BY 12Z. THEREFORE FORECAST THINKING IS
UNCHANGED. CIGS SHOULD GRADUALLY IMPROVE BY NOON WITH THE
POTENTIAL FOR A STRATOCU DECK PERSISTING THROUGH A GOOD PORTION OF
THE DAY. SFC WINDS WILL GRADUALLY VEER WITH RIDGING NOSING IN.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HENNECKE
LONG TERM...OMITT
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS GRAY ME
1035 PM EDT FRI MAY 24 2013
.SYNOPSIS...
A COLD FRONT WILL PUSH OFFSHORE AND STALL THIS EVENING. LOW
PRESSURE WILL DEVELOP ON THE FRONT NEAR CAPE COD AND WILL SLOWLY
DRIFT NORTH THROUGH THE GULF OF MAINE SATURDAY AND SATURDAY NIGHT.
LOW PRESSURE WILL ACCELERATE NORTH INTO LABRADOR ON SUNDAY. HIGH
PRESSURE WILL BUILD IN FROM THE WEST SUNDAY NIGHT THROUGH MONDAY.
HIGH PRESSURE WILL SHIFT OFFSHORE ON TUESDAY. A WARM FRONT WILL
APPROACH FROM THE SOUTHWEST TUESDAY NIGHT AND WEDNESDAY AND WILL
PUSH EAST OF THE REGION WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH SATURDAY/...
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS...WITH THE COLD
FRONT NOW HAVING SLIPPED SOUTH OF THE COAST WATERS AS OF 0230Z. LOW
PRESSURE WILL CONTINUE TO TAKE SHAPE OFF THE NEW ENG COASTLINE
THEREAFTER...WITH CYCLOGENESIS OCCURRING NEAR CAPE COD THIS
EVENING.
LATEST HRRR MODEL PICKING UP WELL ON CONVECTIVE SEGMENTS CROSSING
THE FORECAST AREA AT THIS TIME. THIS MODEL DEPICTS MORE AREAS OF
RAIN MOVING THROUGH THE REGION LATE TONIGHT AND SATURDAY MORNING.
WILL CONTINUE TO MONITOR COLD AIR RUSHING INTO THE MTNS FROM
CANADA OVERNIGHT. THERE COULD BE SOME MIXED SNOW AND RAIN OVER THE
HIGHER TERRAIN FOR THIS STORM WHICH IS VERY SIMILAR TO THE MAY
26TH 1967 EVENT.
HAVE ADJUSTED WINDS AND TEMPS FOR THE HIGHER TERRAIN. WINDS WILL
BECOME RATHER GUSTY FOR ANY HIKERS OUT OF THE NORTH AND NORTH OVER
THE NEXT COUPLE OF DAYS...WITH SOME SNOW ACROSS THE HIGH TERRAIN.
PREV DISC...
COLD FRONT CURRENTLY MOVING EAST THROUGH EASTERN NEW HAMPSHIRE
AND NORTHWEST MAINE AND THIS BOUNDARY WILL CONTINUE TO PUSH OFF TO
THE EAST THROUGH THE REMAINDER OF THE AFTERNOON. FRONT WILL STALL
OFFSHORE THIS EVENING AND WILL BE THE FOCUS OF LIGHT TO MODERATE
RAINFALL IN MID COAST AND CENTRAL MAINE DURING THE REMAINDER OF
THE AFTERNOON INTO THIS EVENING. WILL SEE A BRIEF BREAK IN THE
ACTION ACROSS NEW HAMPSHIRE DURING THE REST OF THE AFTERNOON
BEFORE NEXT BATCH OF PRECIP EDGES IN FROM THE WEST. WILL TAKE SOME
TIME FOR LOW PRESSURE TO GET SPUN UP OVERNIGHT SO THIS BREAK MAY
TRANSLATE EASTWARD INTO WESTERN MAINE FOR THE EVENING HOURS BEFORE
850 OVER-RUNNING GETS GOING IN EARNEST ACROSS WESTERN MAINE AFTER
MIDNIGHT.
12Z MODELS TRENDING FARTHER WEST WITH AXIS OF HEAVIEST PRECIP AND
COMING INTO LINE WITH LAST NIGHT 00Z ECMWF. 24 HOUR QPF FOR THE
MOUNTAINS AND CONNECTICUT VALLEY DOWN TO AROUND AN INCH TO 1.5
INCHES THROUGH 00Z SUN. WITH THIS IN MIND...DOESN`T APPEAR
FLOODING WILL BE AN ISSUE CONSIDERING THE BREAK IN THE ACTION
THIS AFTERNOON AND LONG DURATION OF THE EVENT ITSELF...SO HOLDING
OFF ON ANY WATCHES AT THIS POINT IN TIME.
&&
.SHORT TERM /SATURDAY NIGHT/...
RAIN WILL CONTINUE SATURDAY THROUGH SATURDAY NIGHT AS SURFACE LOW
BECOMES TRAPPED UNDER UPPER LEVEL SYSTEM AND MEANDERS AROUND THE
GULF OF MAINE THROUGH SUNDAY MORNING. MAY SEE SOME WET SNOW OVER
THE HIGHEST TERRAIN AT SOME POINT ON SATURDAY IN FAR WESTERN ZONES BUT
ENOUGH WARM AIR WRAPS AROUND THE SYSTEM THAT THIS WOULD BE FAIRLY
BRIEF. BETTER CHANCE FOR THIS WOULD BE IN THE GREENS OF VERMONT
AND THE DACKS. WILL BE A COLD AND BLUSTERY DAY WITH TEMPS HOLDING
IN THE 40S IN MOST AREAS AND SHOWING LITTLE CHANGE SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
UPR LVL AND SFC LOWS LIFTING NE ON SUNDAY WITH STEADIER PRCP
BECOMING MORE SCT IN NATURE AND LIGHTER IN INTENSITY. ANY LEFTOVER
SHRA ENDING SUNDAY NGT AS THE SYSTEM MOVES INTO THE MARITIMES.
MEMORIAL DAY LOOKS LIKE FAIR WX NOW WITH SYSTEM PULLING OUT FAR
ENOUGH TO THE NE. STILL SOME CYCLONIC FLOW ALOFT AND SOME LEFTOVER
MOISTURE THAT COULD PRODUCE SOME CLOUDINESS ESPECIALLY IN THE N/MT
ZONES DUE TO UPSLOPING NW SFC WINDS. MIGHT SEE AN ISOLD SHRA IN
THE N/MT ZONES OTRW NO PRCP EXPECTED ON MEMORIAL DAY.
HIGH PRES AND UPR LVL RIDGE BUILD IN FOR TUESDAY INTO WEDNESDAY.
THE UPR LVL RIDGE HOLDS 0N OVER THE ERN U.S. BUT A SERIES OF WEAK
UPR LVL SHORT WAVE TROFS DRIVE THRU THE RIDGE FOR LATE WEDNESDAY
AND THURSDAY. THIS FORMS A WRM FRONTAL BOUNDARY TO OUR S THAT
LIFTS N AND WILL PROVIDE SOME CLOUDINESS AND ISOLD TO SCT SHRA
FROM LATE WEDNESDAY THRU THURSDAY. THE UPR LVL RIDGE BECOMES
BETTER ESTABLISHED OVER THE E COAST THURSDAY NGT AND FRIDAY AS THE
SHORT WAVES EXIT THE COAST. THIS SHOULD ALLOW WRM AIR TO CONT
MOVING IN FROM THE SW. STILL CAN`T RULE OUT PSBL SHRA DUE TO WRM
FNT MOVING THRU.
GENERALLY USED BLEND OF GFS40/NAM/MET/MAV/HPC QPF FOR PERIODS 4
AND 5 THEN GFS40, GMOS, HPC QPF, MEX MOS AND WNA4 FOR THE REST OF
THE LONG TERM FCST.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...IFR/LIFR CEILINGS TONIGHT THROUGH SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...MVFR TO PSBL IFR IN SHRA
THAT WILL BE TAPERING OFF SUNDAY INTO SUNDAY NGT. MAINLY VFR
MONDAY THRU TUESDAY AND MOST OF WEDNESDAY.
&&
.MARINE...
SHORT TERM...HAVE EXTENDED SCA TO GO RIGHT THROUGH SATURDAY.
ALTHOUGH WINDS DROP OFF AT SOME POINT...WAVES WILL REMAIN AT LEAST
IN THE 3 TO 5 FOOT RANGE...WITH GREATER SEAS OUT OVER THE OPEN WATERS.
COASTAL FLOOD ADVISORY FOR MINOR SPLASH-OVER AROUND THE TIME OF
HIGH TIDE.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...SCA WIND GUSTS AND SEAS
PSBL SUNDAY THRU MOST OF SUNDAY NGT THEN HIGH PRES DROPS
CONDITIONS BELOW SCA LEVELS MONDAY THRU WEDNESDAY.
&&
.FIRE WEATHER...
NO PROBLEMS NOTED.
&&
.COASTAL SPLASH-OVER...
VERY MINOR EFFECTS AROUND THE TIME OF HIGH TIDE WHICH WILL OCCUR SHORTLY.
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR
MEZ023>028.
NH...COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NHZ014.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR ANZ150>154.
&&
$$
JC
AREA FORECAST DISCUSSION
NWS GRAY ME
804 PM EDT FRI MAY 24 2013
.SYNOPSIS...
A COLD FRONT WILL PUSH OFFSHORE AND STALL THIS EVENING. LOW
PRESSURE WILL DEVELOP ON THE FRONT NEAR CAPE COD AND WILL SLOWLY
DRIFT NORTH THROUGH THE GULF OF MAINE SATURDAY AND SATURDAY NIGHT.
LOW PRESSURE WILL ACCELERATE NORTH INTO LABRADOR ON SUNDAY. HIGH
PRESSURE WILL BUILD IN FROM THE WEST SUNDAY NIGHT THROUGH MONDAY.
HIGH PRESSURE WILL SHIFT OFFSHORE ON TUESDAY. A WARM FRONT WILL
APPROACH FROM THE SOUTHWEST TUESDAY NIGHT AND WEDNESDAY AND WILL
PUSH EAST OF THE REGION WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH SATURDAY/...
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS...WITH THE COLD
FRONT SLIPPING THROUGH THE COAST WATERS AS OF 00Z. LOW PRESSURE
WILL CONTINUE TO TAKE SHAPE OFF THE NEW ENG COASTLINE
THEREAFTER...WITH CYCLOGENESIS OCCURRING NEAR CAPE COD THIS
EVENING.
LATEST HRRR MODEL PICKING UP WELL ON CONVECTIVE SEGMENTS CROSSING
THE FORECAST AREA AT THIS TIME. THIS MODEL DEPICTS MORE AREAS OF
RAIN MOVING THROUGH THE REGION LATE TONIGHT AFTER A BREAK IN THE
ACTION LATER THIS EVENING.
WILL CONTINUE TO MONITOR COLD AIR RUSHING INTO THE MTNS FROM
CANADA OVERNIGHT. THERE COULD BE SOME MIXED SNOW AND RAIN OVER THE
HIGHER TERRAIN FOR THIS STORM WHICH IS VERY SIMILAR TO THE MAY
26TH 1967 EVENT.
HAVE ADJUSTED WINDS AND TEMPS FOR THE HIGHER TERRAIN. WINDS WILL
BECOME RATHER GUSTY FOR ANY HIKERS OUT OF THE NORTH AND NORTH OVER
THE NEXT COUPLE OF DAYS...WITH SOME SNOW ACROSS THE HIGH TERRAIN.
PREV DISC...
COLD FRONT CURRENTLY MOVING EAST THROUGH EASTERN NEW HAMPSHIRE
AND NORTHWEST MAINE AND THIS BOUNDARY WILL CONTINUE TO PUSH OFF TO
THE EAST THROUGH THE REMAINDER OF THE AFTERNOON. FRONT WILL STALL
OFFSHORE THIS EVENING AND WILL BE THE FOCUS OF LIGHT TO MODERATE
RAINFALL IN MID COAST AND CENTRAL MAINE DURING THE REMAINDER OF
THE AFTERNOON INTO THIS EVENING. WILL SEE A BRIEF BREAK IN THE
ACTION ACROSS NEW HAMPSHIRE DURING THE REST OF THE AFTERNOON
BEFORE NEXT BATCH OF PRECIP EDGES IN FROM THE WEST. WILL TAKE SOME
TIME FOR LOW PRESSURE TO GET SPUN UP OVERNIGHT SO THIS BREAK MAY
TRANSLATE EASTWARD INTO WESTERN MAINE FOR THE EVENING HOURS BEFORE
850 OVER-RUNNING GETS GOING IN EARNEST ACROSS WESTERN MAINE AFTER
MIDNIGHT.
12Z MODELS TRENDING FARTHER WEST WITH AXIS OF HEAVIEST PRECIP AND
COMING INTO LINE WITH LAST NIGHT 00Z ECMWF. 24 HOUR QPF FOR THE
MOUNTAINS AND CONNECTICUT VALLEY DOWN TO AROUND AN INCH TO 1.5
INCHES THROUGH 00Z SUN. WITH THIS IN MIND...DOESN`T APPEAR
FLOODING WILL BE AN ISSUE CONSIDERING THE BREAK IN THE ACTION
THIS AFTERNOON AND LONG DURATION OF THE EVENT ITSELF...SO HOLDING
OFF ON ANY WATCHES AT THIS POINT IN TIME.
&&
.SHORT TERM /SATURDAY NIGHT/...
RAIN WILL CONTINUE SATURDAY THROUGH SATURDAY NIGHT AS SURFACE LOW
BECOMES TRAPPED UNDER UPPER LEVEL SYSTEM AND MEANDERS AROUND THE
GULF OF MAINE THROUGH SUNDAY MORNING. MAY SEE SOME WET SNOW OVER
THE HIGHEST TERRAIN AT SOME POINT ON SATURDAY IN FAR WESTERN ZONES BUT
ENOUGH WARM AIR WRAPS AROUND THE SYSTEM THAT THIS WOULD BE FAIRLY
BRIEF. BETTER CHANCE FOR THIS WOULD BE IN THE GREENS OF VERMONT
AND THE DACKS. WILL BE A COLD AND BLUSTERY DAY WITH TEMPS HOLDING
IN THE 40S IN MOST AREAS AND SHOWING LITTLE CHANGE SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
UPR LVL AND SFC LOWS LIFTING NE ON SUNDAY WITH STEADIER PRCP
BECOMING MORE SCT IN NATURE AND LIGHTER IN INTENSITY. ANY LEFTOVER
SHRA ENDING SUNDAY NGT AS THE SYSTEM MOVES INTO THE MARITIMES.
MEMORIAL DAY LOOKS LIKE FAIR WX NOW WITH SYSTEM PULLING OUT FAR
ENOUGH TO THE NE. STILL SOME CYCLONIC FLOW ALOFT AND SOME LEFTOVER
MOISTURE THAT COULD PRODUCE SOME CLOUDINESS ESPECIALLY IN THE N/MT
ZONES DUE TO UPSLOPING NW SFC WINDS. MIGHT SEE AN ISOLD SHRA IN
THE N/MT ZONES OTRW NO PRCP EXPECTED ON MEMORIAL DAY.
HIGH PRES AND UPR LVL RIDGE BUILD IN FOR TUESDAY INTO WEDNESDAY.
THE UPR LVL RIDGE HOLDS 0N OVER THE ERN U.S. BUT A SERIES OF WEAK
UPR LVL SHORT WAVE TROFS DRIVE THRU THE RIDGE FOR LATE WEDNESDAY
AND THURSDAY. THIS FORMS A WRM FRONTAL BOUNDARY TO OUR S THAT
LIFTS N AND WILL PROVIDE SOME CLOUDINESS AND ISOLD TO SCT SHRA
FROM LATE WEDNESDAY THRU THURSDAY. THE UPR LVL RIDGE BECOMES
BETTER ESTABLISHED OVER THE E COAST THURSDAY NGT AND FRIDAY AS THE
SHORT WAVES EXIT THE COAST. THIS SHOULD ALLOW WRM AIR TO CONT
MOVING IN FROM THE SW. STILL CAN`T RULE OUT PSBL SHRA DUE TO WRM
FNT MOVING THRU.
GENERALLY USED BLEND OF GFS40/NAM/MET/MAV/HPC QPF FOR PERIODS 4
AND 5 THEN GFS40, GMOS, HPC QPF, MEX MOS AND WNA4 FOR THE REST OF
THE LONG TERM FCST.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...IFR/LIFR CEILINGS TONIGHT THROUGH SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...MVFR TO PSBL IFR IN SHRA
THAT WILL BE TAPERING OFF SUNDAY INTO SUNDAY NGT. MAINLY VFR
MONDAY THRU TUESDAY AND MOST OF WEDNESDAY.
&&
.MARINE...
SHORT TERM...HAVE EXTENDED SCA TO GO RIGHT THROUGH SATURDAY.
ALTHOUGH WINDS DROP OFF AT SOME POINT...WAVES WILL REMAIN AT LEAST
IN THE 3 TO 5 FOOT RANGE...WITH GREATER SEAS OUT OVER THE OPEN WATERS.
COASTAL FLOOD ADVISORY FOR MINOR SPLASH-OVER AROUND THE TIME OF
HIGH TIDE.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...SCA WIND GUSTS AND SEAS
PSBL SUNDAY THRU MOST OF SUNDAY NGT THEN HIGH PRES DROPS
CONDITIONS BELOW SCA LEVELS MONDAY THRU WEDNESDAY.
&&
.FIRE WEATHER...
NO PROBLEMS NOTED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR
MEZ023>028.
NH...COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NHZ014.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR ANZ150>154.
&&
$$
JC
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
937 PM EDT FRI MAY 24 2013
.SYNOPSIS...
DRY AND COOL WEATHER CAN BE EXPECTED FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
WINDS ARE WEAKENING QUICKLY AS SURFACE HIGH BUILDS IN A BIT FASTER
THAN MODELS DEPICTED. SUBSIDENCE AND DRY AIR CONTINUE TO ERODE THE
CLOUD COVER FROM WEST TO EAST. STILL DIFFICULT TO TIME EXACTLY
WILL USE LATEST RAP MODEL RUN AS GUIDANCE.
PREVIOUS DISCUSSION...
THE UPPER LEVEL TROUGH WILL CONTINUE TO PIVOT ACROSS THE REGION
THROUGH THE AFTERNOON AND EVENING AS HIGH PRESSURE TRIES TO BUILD
OVERHEAD AT THE SURFACE. COLD NORTHWEST FLOW CONTINUES TO KEEP
CLOUD COVER OVER MUCH OF THE FORECAST AREA THROUGH THIS
AFTERNOON...WHICH IS RIGHT IN LINE WITH THE LATEST RUC FORECAST.
WITH CLOUD COVER STILL IN PLACE...CONTINUED A DOWNWARD TREND IN
THE HIGH TEMPERATURES FOR THE AFTERNOON...WITH PIT LIKELY TO BE
VERY CLOSE TO BREAKING IT`S LOW HIGH TEMPERATURES RECORD FROM
1877.
THE MOST RECENT MODEL RUNS CONTINUE TO SUGGEST THAT CLOUDS WILL
EVENTUALLY DIMINISH OVER THE ENTIRE REGION...LASTING LONGEST IN
THE RIDGES. HOW FAST THE CLOUDS DIMINISH WILL PLAY A BIG ROLE IN
HOW QUICKLY TEMPERATURES DROP OVERNIGHT. HOWEVER...SINCE
TEMPERATURES ARE ALREADY LOWER THAN ORIGINALLY FORECAST...CLEARING
SKIES SHOULD ALLOW LOWS IN THE LOW TO MID 30`S TO BE REALIZED
RELATIVELY QUICKLY. FOR NOW...CONTINUED THE FROST/FREEZE AS
IS...ALTHOUGH SOME COUNTIES MAY NEED TO BE UPGRADED TO A FREEZE IF
SKIES CLEAR SOONER AND WINDS DECOUPLE.
HIGH PRESSURE WILL BUILD OVERHEAD SATURDAY BRINGING A CLEAR DAY
BUT NORTHWEST FLOW WILL KEEP TEMPERATURES 10 TO 15 BELOW SEASONAL
AVERAGES.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL CONTINUE TO DOMINATE THROUGH THE SHORT TERM
PERIOD. TEMPERATURES WERE KEPT 5 DEGREES BELOW SEASONAL AVERAGES
SUNDAY...BUT MODERATED CLOSER TO NORMAL BY MONDAY. AN APPROACHING
WARM FRONT COULD BRING THE CHANCE FOR A SHOWER IN THE SOUTHERN
PORTIONS OF THE FORECAST AREA LATE MONDAY BUT FOR NOW...LEFT LOW
END POPS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A WARM FRONT MOVING NORTH ACROSS THE DISTRICT TUESDAY WILL BRING
A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH WEDNESDAY. AS THE WARM
FRONT MOVES NORTH OF THE FORECAST AREA THURSDAY WARM AND MORE HUMID
CONDITIONS WILL RETURN WITH HIGH TEMPERATURES INTO THE 80S THROUGH
FRIDAY. THERE WILL BE A SLIGHT CHANCE OF DIURNAL THUNDERSTORMS
THURSDAY AND FRIDAY.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
GENERAL STRATO-CU REMAINS IN PLACE EXCEPT AT ZANESVILLE WHERE SKIES
HAVE CLEARED. CLOUD DECK IS THIN AND HAS A DIURNAL LOOK ON SAT
PIX. BREAKS CONTINUE TO DEVELOP AND WITH DEEP DRYING MOVING INTO
REGION OVERNIGHT STILL EXPECT STRATO-CU TO GRADUALLY DISSIPATE
TOWARD OR JUST AFTER MIDNIGHT. WINDS ALREADY BEGINNING TO WEAKEN
AS SURFACE RIDGE BUILDS EAST FROM GREAT LAKES. 18Z SOUNDINGS SHOW
DECOUPLING STILL OCCURRING LATE TONIGHT WITH A NORTH TO NORTHWEST
WIND UNDER 6 KTS. BY MID MORNING SATURDAY SUNSHINE WILL MIX DOWN
NORTHWEST WINDS WITH GUSTS OVER 20 KTS EXPECTED. ONLY SCT VFR CU
EXPECTED.
.OUTLOOK.../SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE WILL
MAINTAIN GENERAL VFR THROUGH MONDAY. A WARM FRONT WILL BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS FOR LATE TUESDAY INTO WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR MDZ001.
OH...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR PAZ020-021-
029-031-073-075.
FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR PAZ007>009-
013>016-022-023-074-076.
WV...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR WVZ001>004-
012-021-022.
FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
726 PM EDT FRI MAY 24 2013
.SYNOPSIS...
DRY AND COOL WEATHER CAN BE EXPECTED FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
ADJUSTMENTS TO WINDS OVERNIGHT...JUST WEAKENED THEM A BIT FASTER.
TRIED TO TIME THE DECAYING OF CLOUD DECK...WITH LOW CONFIDENCE.
WESTERN EDGE OF CLOUDS ARE ERODING QUICKLY...BUT WITH CYCLONIC
FLOW AND COLD AIR ALOFT...TIMING IS DIFFICULT.
PREVIOUS DISCUSSION...
THE UPPER LEVEL TROUGH WILL CONTINUE TO PIVOT ACROSS THE REGION
THROUGH THE AFTERNOON AND EVENING AS HIGH PRESSURE TRIES TO BUILD
OVERHEAD AT THE SURFACE. COLD NORTHWEST FLOW CONTINUES TO KEEP
CLOUD COVER OVER MUCH OF THE FORECAST AREA THROUGH THIS
AFTERNOON...WHICH IS RIGHT IN LINE WITH THE LATEST RUC FORECAST.
WITH CLOUD COVER STILL IN PLACE...CONTINUED A DOWNWARD TREND IN
THE HIGH TEMPERATURES FOR THE AFTERNOON...WITH PIT LIKELY TO BE
VERY CLOSE TO BREAKING IT`S LOW HIGH TEMPERATURES RECORD FROM
1877.
THE MOST RECENT MODEL RUNS CONTINUE TO SUGGEST THAT CLOUDS WILL
EVENTUALLY DIMINISH OVER THE ENTIRE REGION...LASTING LONGEST IN
THE RIDGES. HOW FAST THE CLOUDS DIMINISH WILL PLAY A BIG ROLE IN
HOW QUICKLY TEMPERATURES DROP OVERNIGHT. HOWEVER...SINCE
TEMPERATURES ARE ALREADY LOWER THAN ORIGINALLY FORECAST...CLEARING
SKIES SHOULD ALLOW LOWS IN THE LOW TO MID 30`S TO BE REALIZED
RELATIVELY QUICKLY. FOR NOW...CONTINUED THE FROST/FREEZE AS
IS...ALTHOUGH SOME COUNTIES MAY NEED TO BE UPGRADED TO A FREEZE IF
SKIES CLEAR SOONER AND WINDS DECOUPLE.
HIGH PRESSURE WILL BUILD OVERHEAD SATURDAY BRINGING A CLEAR DAY
BUT NORTHWEST FLOW WILL KEEP TEMPERATURES 10 TO 15 BELOW SEASONAL
AVERAGES.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL CONTINUE TO DOMINATE THROUGH THE SHORT TERM
PERIOD. TEMPERATURES WERE KEPT 5 DEGREES BELOW SEASONAL AVERAGES
SUNDAY...BUT MODERATED CLOSER TO NORMAL BY MONDAY. AN APPROACHING
WARM FRONT COULD BRING THE CHANCE FOR A SHOWER IN THE SOUTHERN
PORTIONS OF THE FORECAST AREA LATE MONDAY BUT FOR NOW...LEFT LOW
END POPS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A WARM FRONT MOVING NORTH ACROSS THE DISTRICT TUESDAY WILL BRING
A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH WEDNESDAY. AS THE WARM
FRONT MOVES NORTH OF THE FORECAST AREA THURSDAY WARM AND MORE HUMID
CONDITIONS WILL RETURN WITH HIGH TEMPERATURES INTO THE 80S THROUGH
FRIDAY. THERE WILL BE A SLIGHT CHANCE OF DIURNAL THUNDERSTORMS
THURSDAY AND FRIDAY.
&&
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
GENERAL STRATO-CU REMAINS IN PLACE EXCEPT AT ZANESVILLE WHERE SKIES
HAVE CLEARED. CLOUD DECK IS THIN AND HAS A DIURNAL LOOK ON SAT
PIX. BREAKS CONTINUE TO DEVELOP AND WITH DEEP DRYING MOVING INTO
REGION OVERNIGHT STILL EXPECT STRATO-CU TO GRADUALLY DISSIPATE
TOWARD OR JUST AFTER MIDNIGHT. WINDS ALREADY BEGINNING TO WEAKEN
AS SURFACE RIDGE BUILDS EAST FROM GREAT LAKES. 18Z SOUNDINGS SHOW
DECOUPLING STILL OCCURRING LATE TONIGHT WITH A NORTH TO NORTHWEST
WIND UNDER 6 KTS. BY MID MORNING SATURDAY SUNSHINE WILL MIX DOWN
NORTHWEST WINDS WITH GUSTS OVER 20 KTS EXPECTED. ONLY SCT VFR CU
EXPECTED.
.OUTLOOK.../SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE WILL
MAINTAIN GENERAL VFR THROUGH MONDAY. A WARM FRONT WILL BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS FOR LATE TUESDAY INTO WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR MDZ001.
OH...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR PAZ020-021-
029-031-073-075.
FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR PAZ007>009-
013>016-022-023-074-076.
WV...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR WVZ001>004-
012-021-022.
FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
523 PM CDT THU MAY 23 2013
.SHORT TERM...THROUGH MONDAY
ISSUED AT 204 PM CDT THU MAY 23 2013
23.12Z RAOBS SHOW GOOD 925-850MB COLD ADVECTION ACROSS THE WRN GREAT
LAKES THIS MORNING IN MODERATE NORTHEAST FLOW. FRONTAL SLOPE OVER
THE STATE IS SOMETHING THAT WILL COME INTO PLAY FOR UPCOMING
FORECAST AND HOW FAR IT SLIDES SOUTHWEST. AT 12Z KINL-KABR HAD A 7C
TEMPERATURE DIFFERENCE AT 850MB /12C AT 925MB/. A MASSIVE DRYING
ACROSS MN OCCURRED OVERNIGHT WITH PRECIPITATELY WATER VALUES
PLUMMETING FROM 0.90 TO 0.32 INCHES...OR 136 TO 48 PERCENT NORMAL.
THE SURFACE RIDGE NOSING IN IS QUITE DRY WITH PRECIPITABLE WATER
VALUES IN THE 30 PERCENT RANGE ACROSS SRN CANADA. THIS GAVE WAY TO A
SUNNY BUT COOL DAY TODAY. A HIGHER AMPLITUDE RIDGE AXIS IS
ANCHORED IN THE DAKOTAS AND SOUTH...WHILE A DEEPER CYCLONE HAS NOW
SHIFTED ONSHORE INTO THE NWRN U.S. NUMEROUS SPOKES OF ENERGY ARE
CIRCULATING AROUND THAT LOW...ONE OF WHICH IS QUITE STRONG OVER
NEVADA WITH RAP ANALYSIS SHOWING A TROPOPAUSE FOLD TO NEAR
500MB...ON THE POLEWARD SIDE OF A MEASURED 100KT 250MB JET CORE
NOSE. THIS IS DRIVING HEIGHT FALLS ACROSS MT/ID/UT. SURFACE DEW
POINTS OF MEANING FOR CONVECTION ARE LOCATED IN OKLAHOMA...SOON TO
RETURN NORTHWARD.
FORECAST IS ON TRACK FOR CALMING WINDS TONIGHT AND CLEAR SKIES.
WIDESPREAD FROST SHOULD OCCUR WITH LOWER 30S FORECAST ACROSS NWRN
WI. WITH LOWER DEW POINTS OVER NWRN WI COUNTIES CURRENTLY...HAVE
DECIDED TO JUST ADD ALL OF THOSE COUNTIES INTO THE FROST ADVISORY.
BIG PICTURE DURING THIS PERIOD IS FALLING HEIGHTS AND PRESSURE IN
THE FRONT RANGE WITH SOUTHERLY FLOW INCREASING AND A RETURN OF
MOISTURE TO NEB/SD FRIDAY NIGHT. THIS WILL PLACE THE LOW-LEVEL
THERMAL BOUNDARY ACROSS THE FORECAST AREA FROM 850-925MB...SLIGHTLY
DISPLACED SWWRD...FROM KABR-KMLI. THE CONSENSUS NCEP MODELS AT
23.12Z REMAIN CONSISTENT WITH THEIR PREVIOUS RUNS ON THE FRONTAL
BOUNDARY BECOMING ACTIVE IN THE DAKOTAS/NEB FRIDAY EVENING AND
SHIFTING EAST INTO MN/IA OVERNIGHT. THE 23.00Z ECMWF/UKMET
SOLUTIONS DO AS WELL...HOWEVER THEY REMAIN FURTHER WEST.
THE 300/305K SURFACE IN THE NCEP SOLUTIONS REMAINS CONSISTENT WITH
AN 8G/KG MOISTURE SURGE ISENTROPICALLY LIFTING AND CONVERGING INTO
CENTRAL AND ERN MN FRIDAY OVERNIGHT WITH A FETCH OF ABOUT 500 J/KG
OF MUCAPE FEEDING IT. THE NAM SEEMS TO BE THE MOST AGRESSIVE. NOT
OVERLY IMPRESSIVE FOR SEVERE WEATHER...BUT RATHER THERE IS ENOUGH
FORCING TO GENERATE RA/TSRA SWWRD OF MSP. THE ECMWF SOLUTIONS
SUGGEST MORE OF A FOCUS IN SRN/SWRN MN. THE MAIN QUESTION IS HOW
FAR EAST DOES THIS CONVECTIVE COMPLEX TRACK FRIDAY NIGHT AND HOW FAR
EAST DOES THE FRONTAL BOUNDARY LIFT. HAVE INCREASED RAIN CHANCES
FURTHER EAST FOR FRIDAY NIGHT AND SATURDAY...HOWEVER WITH THE
VERIFICATION RECORD OF THE ECMWF...THERE IS STILL A CHANCE THE
EASTERN AREAS WILL BE DRY. CONFIDENCE IS LOW ON THE EXACT
LOCATION OF THE WEATHER...BUT HIGHER THAT IT WILL BE AN ACTIVE
FRONTAL ZONE WITH SHRA/ISO TSRA.
THIS QUESTION REMAINS THROUGH MONDAY...HOW FAR EAST WILL THE
FRONTAL BAND BE LOCATED. THE FRONT WILL LIKELY REMAIN ACTIVE WITH
SHOWERS/STORMS AND CLOUDS...AND HIGHS QUITE A BIT COOLER THANOUTSIDE
THE BAND. OVERALL...HAVE INCREASED RAIN CHANCES IN THE WRN/SRN
FORECAST AREA AND TRIED TO REMAIN NEARLY DRY IN THE EAST. SEEMS
LIKE IT WILL BE A CLOUDY WEEKEND...AND THUS HAVE LOWERED HIGHS
SUNDAY AND MONDAY AS WELL. SEVERE WEATHER THREATS ARE MOST
POSSIBLE IN SWRN MN CLOSER TO THE CAPE POOL...AND MONDAY LOOKS
MOST FAVORABLE SHOULD THE INSTABILITY INCREASE AS THE WARM FRONT
MOVES TOWARD MN. HOWEVER...ACTIVITY ALONG THAT FRONT THIS WEEKEND
MAY HAVE MUCH TO DO WITH HOW THE ENVIRONMENT/FRONT EVOLVES MONDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 241 PM CDT THU MAY 23 2013
IT CONTINUES TO LOOK LIKE WE/LL UNFORTUNATELY NEED TO KEEP A
PROLONGED PERIOD OF CHANCE POPS IN THE FORECAST THROUGH THE WEEK
AS THE BAROCLINIC ZONE LINGERS IN THE AREA... WITH ELEVATED
INSTABILITY AND PERSISTENT WARM ADVECTION WORK TO GENERATE
SCATTERED SHRA/TSRA. THERE WILL UNDOUBTEDLY BE SOME DRY PERIODS...
WITH PCPN FOCUSED WHEN INDIVIDUAL SHORTWAVES RIPPLE SOUTHEAST
THROUGH THE UPPER FLOW... BUT AT THIS POINT IT IS IMPOSSIBLE TO
TRY AND PIN POINT WHEN SUCH DRY PERIODS MIGHT OCCUR. THE 12Z ECMWF
HAS COME AROUND MORE IN LINE WITH THE GFS IN KEEPING THINGS MORE
ACTIVE IN OUR AREA THROUGHOUT THE TIME PERIOD... ALTHOUGH BOTH
SUGGEST WE SHOULD FINALLY BRING THE UPPER TROUGH EAST TOWARD THE
REGION BY THE END OF THE WEEK. DEPENDING ON HOW THAT UNFOLDS... WE
COULD HAVE A POSSIBILITY FOR FOCUSED CONVECTION AND POSSIBLE
SEVERE WEATHER DURING THE THURSDAY-FRIDAY TIME FRAME. BUT... UNTIL
THAT POINT THE MAIN ISSUES WOULD LIKELY BE LOCALLY HEAVY RAIN AND
PERHAPS SOME HAIL. IN GENERAL... TEMPERATURES WILL WARM THROUGH
THE WEEK AS THE BONAFIDE WARM SECTOR SLOWLY LIFTS NORTH INTO THE
AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 459 PM CDT THU MAY 23 2013
VFR DURING THE PERIOD. INCREASING HIGH CLOUDS FROM THE WEST DURING
THE DAY FRIDAY. CHANCE OF SHRA LIMITED TO FAR WESTERN SITES.
INTRODUCED VCSH FOR NOW. LIGHT NORTHEAST TO EAST WINDS BECOMING
SOUTHEAST OVERNIGHT AND INCREASING ON FRIDAY. GUSTY AT MN SITES BY
MIDDAY.
KMSP...
VFR THROUGH PERIOD. NEXT CHANCE OF SHOWERS MOVES IN LATER FRIDAY
NIGHT. LIGHT NORTHEAST TO EAST WIND BECOMING SOUTHEAST FRIDAY AND
A BIT GUSTY BY MIDDAY.
/OUTLOOK FOR KMSP/
FRIDAY NIGHT...VFR. CHANCE OF SHOWERS. SOUTHEAST WIND 5 TO 15 KT.
SATURDAY...BRIEF MVFR CEILINGS POSSIBLE WITH A CHANCE OF
SHRA/TSRA. SOUTHEAST WIND 10 TO 20 KT.
SATURDAY NIGHT...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A
CHANCE OF SHRA/TSRA. SOUTHEAST WIND 10 TO 20 KT.
SUNDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE OF
SHRA/TSRA...BRIEF IFR CONDITIONS POSSIBLE. SOUTHEAST WIND 10 TO 20
KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM CDT FRIDAY FOR
MNZ045-052-053-063.
WI...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM CDT FRIDAY FOR
WIZ014>016-023>028.
&&
$$
SHORT TERM...BAUMGARDT/ARX
LONG TERM...
AVIATION...DE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
246 PM CDT THU MAY 23 2013
.SHORT TERM...THROUGH MONDAY
ISSUED AT 204 PM CDT THU MAY 23 2013
23.12Z RAOBS SHOW GOOD 925-850MB COLD ADVECTION ACROSS THE WRN GREAT
LAKES THIS MORNING IN MODERATE NORTHEAST FLOW. FRONTAL SLOPE OVER
THE STATE IS SOMETHING THAT WILL COME INTO PLAY FOR UPCOMING
FORECAST AND HOW FAR IT SLIDES SOUTHWEST. AT 12Z KINL-KABR HAD A 7C
TEMPERATURE DIFFERENCE AT 850MB /12C AT 925MB/. A MASSIVE DRYING
ACROSS MN OCCURRED OVERNIGHT WITH PRECIPITATELY WATER VALUES
PLUMMETING FROM 0.90 TO 0.32 INCHES...OR 136 TO 48 PERCENT NORMAL.
THE SURFACE RIDGE NOSING IN IS QUITE DRY WITH PRECIPITABLE WATER
VALUES IN THE 30 PERCENT RANGE ACROSS SRN CANADA. THIS GAVE WAY TO A
SUNNY BUT COOL DAY TODAY. A HIGHER AMPLITUDE RIDGE AXIS IS
ANCHORED IN THE DAKOTAS AND SOUTH...WHILE A DEEPER CYCLONE HAS NOW
SHIFTED ONSHORE INTO THE NWRN U.S. NUMEROUS SPOKES OF ENERGY ARE
CIRCULATING AROUND THAT LOW...ONE OF WHICH IS QUITE STRONG OVER
NEVADA WITH RAP ANALYSIS SHOWING A TROPOPAUSE FOLD TO NEAR
500MB...ON THE POLEWARD SIDE OF A MEASURED 100KT 250MB JET CORE
NOSE. THIS IS DRIVING HEIGHT FALLS ACROSS MT/ID/UT. SURFACE DEW
POINTS OF MEANING FOR CONVECTION ARE LOCATED IN OKLAHOMA...SOON TO
RETURN NORTHWARD.
FORECAST IS ON TRACK FOR CALMING WINDS TONIGHT AND CLEAR SKIES.
WIDESPREAD FROST SHOULD OCCUR WITH LOWER 30S FORECAST ACROSS NWRN
WI. WITH LOWER DEW POINTS OVER NWRN WI COUNTIES CURRENTLY...HAVE
DECIDED TO JUST ADD ALL OF THOSE COUNTIES INTO THE FROST ADVISORY.
BIG PICTURE DURING THIS PERIOD IS FALLING HEIGHTS AND PRESSURE IN
THE FRONT RANGE WITH SOUTHERLY FLOW INCREASING AND A RETURN OF
MOISTURE TO NEB/SD FRIDAY NIGHT. THIS WILL PLACE THE LOW-LEVEL
THERMAL BOUNDARY ACROSS THE FORECAST AREA FROM 850-925MB...SLIGHTLY
DISPLACED SWWRD...FROM KABR-KMLI. THE CONSENSUS NCEP MODELS AT
23.12Z REMAIN CONSISTENT WITH THEIR PREVIOUS RUNS ON THE FRONTAL
BOUNDARY BECOMING ACTIVE IN THE DAKOTAS/NEB FRIDAY EVENING AND
SHIFTING EAST INTO MN/IA OVERNIGHT. THE 23.00Z ECMWF/UKMET
SOLUTIONS DO AS WELL...HOWEVER THEY REMAIN FURTHER WEST.
THE 300/305K SURFACE IN THE NCEP SOLUTIONS REMAINS CONSISTENT WITH
AN 8G/KG MOISTURE SURGE ISENTROPICALLY LIFTING AND CONVERGING INTO
CENTRAL AND ERN MN FRIDAY OVERNIGHT WITH A FETCH OF ABOUT 500 J/KG
OF MUCAPE FEEDING IT. THE NAM SEEMS TO BE THE MOST AGRESSIVE. NOT
OVERLY IMPRESSIVE FOR SEVERE WEATHER...BUT RATHER THERE IS ENOUGH
FORCING TO GENERATE RA/TSRA SWWRD OF MSP. THE ECMWF SOLUTIONS
SUGGEST MORE OF A FOCUS IN SRN/SWRN MN. THE MAIN QUESTION IS HOW
FAR EAST DOES THIS CONVECTIVE COMPLEX TRACK FRIDAY NIGHT AND HOW FAR
EAST DOES THE FRONTAL BOUNDARY LIFT. HAVE INCREASED RAIN CHANCES
FURTHER EAST FOR FRIDAY NIGHT AND SATURDAY...HOWEVER WITH THE
VERIFICATION RECORD OF THE ECMWF...THERE IS STILL A CHANCE THE
EASTERN AREAS WILL BE DRY. CONFIDENCE IS LOW ON THE EXACT
LOCATION OF THE WEATHER...BUT HIGHER THAT IT WILL BE AN ACTIVE
FRONTAL ZONE WITH SHRA/ISO TSRA.
THIS QUESTION REMAINS THROUGH MONDAY...HOW FAR EAST WILL THE
FRONTAL BAND BE LOCATED. THE FRONT WILL LIKELY REMAIN ACTIVE WITH
SHOWERS/STORMS AND CLOUDS...AND HIGHS QUITE A BIT COOLER THANOUTSIDE
THE BAND. OVERALL...HAVE INCREASED RAIN CHANCES IN THE WRN/SRN
FORECAST AREA AND TRIED TO REMAIN NEARLY DRY IN THE EAST. SEEMS
LIKE IT WILL BE A CLOUDY WEEKEND...AND THUS HAVE LOWERED HIGHS
SUNDAY AND MONDAY AS WELL. SEVERE WEATHER THREATS ARE MOST
POSSIBLE IN SWRN MN CLOSER TO THE CAPE POOL...AND MONDAY LOOKS
MOST FAVORABLE SHOULD THE INSTABILITY INCREASE AS THE WARM FRONT
MOVES TOWARD MN. HOWEVER...ACTIVITY ALONG THAT FRONT THIS WEEKEND
MAY HAVE MUCH TO DO WITH HOW THE ENVIRONMENT/FRONT EVOLVES MONDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 241 PM CDT THU MAY 23 2013
IT CONTINUES TO LOOK LIKE WE/LL UNFORTUNATELY NEED TO KEEP A
PROLONGED PERIOD OF CHANCE POPS IN THE FORECAST THROUGH THE WEEK
AS THE BAROCLINIC ZONE LINGERS IN THE AREA... WITH ELEVATED
INSTABILITY AND PERSISTENT WARM ADVECTION WORK TO GENERATE
SCATTERED SHRA/TSRA. THERE WILL UNDOUBTEDLY BE SOME DRY PERIODS...
WITH PCPN FOCUSED WHEN INDIVIDUAL SHORTWAVES RIPPLE SOUTHEAST
THROUGH THE UPPER FLOW... BUT AT THIS POINT IT IS IMPOSSIBLE TO
TRY AND PIN POINT WHEN SUCH DRY PERIODS MIGHT OCCUR. THE 12Z ECMWF
HAS COME AROUND MORE IN LINE WITH THE GFS IN KEEPING THINGS MORE
ACTIVE IN OUR AREA THROUGHOUT THE TIME PERIOD... ALTHOUGH BOTH
SUGGEST WE SHOULD FINALLY BRING THE UPPER TROUGH EAST TOWARD THE
REGION BY THE END OF THE WEEK. DEPENDING ON HOW THAT UNFOLDS... WE
COULD HAVE A POSSIBILITY FOR FOCUSED CONVECTION AND POSSIBLE
SEVERE WEATHER DURING THE THURSDAY-FRIDAY TIME FRAME. BUT... UNTIL
THAT POINT THE MAIN ISSUES WOULD LIKELY BE LOCALLY HEAVY RAIN AND
PERHAPS SOME HAIL. IN GENERAL... TEMPERATURES WILL WARM THROUGH
THE WEEK AS THE BONAFIDE WARM SECTOR SLOWLY LIFTS NORTH INTO THE
AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM CDT THU MAY 23 2013
HIGH PRESSURE AREA BUILDING IN WITH NEARLY CLEAR SKIES/VFR.
LARGEST 3 HOURLY PRESSURE CLIMBS ARE SHIFTING OFF TO THE SOUTHEAST
SO GRADIENT WILL SLACKEN CONSIDERABLY GOING INTO THIS EVENING.
EXPECT ANY LINGERING GUSTS TO CALM DOWN AND WITH RIDGE AXIS
SPREADING THROUGH TONIGHT...GRADUAL SHIFT TO SOUTHEAST LOW LEVEL
FLOW WILL MATERIALIZE GOING INTO FRIDAY MORNING. DRY AIRMASS SHOULD
KEEP SKIES CLEAR THROUGH MOST OF FRIDAY AS WELL.
KMSP...
VFR CONDITIONS TO CONTINUE. NORTHEAST WIND THIS AFTERNOON WILL
DECREASE AND SLOWLY BECOME SOUTHEAST BY FRIDAY MORNING.
/OUTLOOK FOR KMSP/
FRIDAY NIGHT...VFR. CHANCE OF SHOWERS. SOUTHEAST WIND 5 TO 15 KT.
SATURDAY...BRIEF MVFR CEILINGS POSSIBLE WITH A CHANCE OF
SHRA/TSRA. SOUTHEAST WIND 10 TO 20 KT.
SATURDAY NIGHT...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A
CHANCE OF SHRA/TSRA. SOUTHEAST WIND 10 TO 20 KT.
SUNDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE OF
SHRA/TSRA...BRIEF IFR CONDITIONS POSSIBLE. SOUTHEAST WIND 10 TO 20
KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM CDT FRIDAY FOR
MNZ045-052-053-063.
WI...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM CDT FRIDAY FOR
WIZ014>016-023>028.
&&
$$
SHORT TERM...BAUMGARDT/ARX
LONG TERM...
AVIATION....SHEA/ARX
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
ISSUED BY NATIONAL WEATHER SERVICE LA CROSSE WI
206 PM CDT THU MAY 23 2013
.SHORT TERM...THROUGH MONDAY
ISSUED AT 204 PM CDT THU MAY 23 2013
23.12Z RAOBS SHOW GOOD 925-850MB COLD ADVECTION ACROSS THE WRN GREAT
LAKES THIS MORNING IN MODERATE NORTHEAST FLOW. FRONTAL SLOPE OVER
THE STATE IS SOMETHING THAT WILL COME INTO PLAY FOR UPCOMING
FORECAST AND HOW FAR IT SLIDES SOUTHWEST. AT 12Z KINL-KABR HAD A 7C
TEMPERATURE DIFFERENCE AT 850MB /12C AT 925MB/. A MASSIVE DRYING
ACROSS MN OCCURRED OVERNIGHT WITH PRECIPITATELY WATER VALUES
PLUMMETING FROM 0.90 TO 0.32 INCHES...OR 136 TO 48 PERCENT NORMAL.
THE SURFACE RIDGE NOSING IN IS QUITE DRY WITH PRECIPITABLE WATER
VALUES IN THE 30 PERCENT RANGE ACROSS SRN CANADA. THIS GAVE WAY TO A
SUNNY BUT COOL DAY TODAY. A HIGHER AMPLITUDE RIDGE AXIS IS
ANCHORED IN THE DAKOTAS AND SOUTH...WHILE A DEEPER CYCLONE HAS NOW
SHIFTED ONSHORE INTO THE NWRN U.S. NUMEROUS SPOKES OF ENERGY ARE
CIRCULATING AROUND THAT LOW...ONE OF WHICH IS QUITE STRONG OVER
NEVADA WITH RAP ANALYSIS SHOWING A TROPOPAUSE FOLD TO NEAR
500MB...ON THE POLEWARD SIDE OF A MEASURED 100KT 250MB JET CORE
NOSE. THIS IS DRIVING HEIGHT FALLS ACROSS MT/ID/UT. SURFACE DEW
POINTS OF MEANING FOR CONVECTION ARE LOCATED IN OKLAHOMA...SOON TO
RETURN NORTHWARD.
FORECAST IS ON TRACK FOR CALMING WINDS TONIGHT AND CLEAR SKIES.
WIDESPREAD FROST SHOULD OCCUR WITH LOWER 30S FORECAST ACROSS NWRN
WI. WITH LOWER DEW POINTS OVER NWRN WI COUNTIES CURRENTLY...HAVE
DECIDED TO JUST ADD ALL OF THOSE COUNTIES INTO THE FROST ADVISORY.
BIG PICTURE DURING THIS PERIOD IS FALLING HEIGHTS AND PRESSURE IN
THE FRONT RANGE WITH SOUTHERLY FLOW INCREASING AND A RETURN OF
MOISTURE TO NEB/SD FRIDAY NIGHT. THIS WILL PLACE THE LOW-LEVEL
THERMAL BOUNDARY ACROSS THE FORECAST AREA FROM 850-925MB...SLIGHTLY
DISPLACED SWWRD...FROM KABR-KMLI. THE CONSENSUS NCEP MODELS AT
23.12Z REMAIN CONSISTENT WITH THEIR PREVIOUS RUNS ON THE FRONTAL
BOUNDARY BECOMING ACTIVE IN THE DAKOTAS/NEB FRIDAY EVENING AND
SHIFTING EAST INTO MN/IA OVERNIGHT. THE 23.00Z ECMWF/UKMET
SOLUTIONS DO AS WELL...HOWEVER THEY REMAIN FURTHER WEST.
THE 300/305K SURFACE IN THE NCEP SOLUTIONS REMAINS CONSISTENT WITH
AN 8G/KG MOISTURE SURGE ISENTROPICALLY LIFTING AND CONVERGING INTO
CENTRAL AND ERN MN FRIDAY OVERNIGHT WITH A FETCH OF ABOUT 500 J/KG
OF MUCAPE FEEDING IT. THE NAM SEEMS TO BE THE MOST AGRESSIVE. NOT
OVERLY IMPRESSIVE FOR SEVERE WEATHER...BUT RATHER THERE IS ENOUGH
FORCING TO GENERATE RA/TSRA SWWRD OF MSP. THE ECMWF SOLUTIONS
SUGGEST MORE OF A FOCUS IN SRN/SWRN MN. THE MAIN QUESTION IS HOW
FAR EAST DOES THIS CONVECTIVE COMPLEX TRACK FRIDAY NIGHT AND HOW FAR
EAST DOES THE FRONTAL BOUNDARY LIFT. HAVE INCREASED RAIN CHANCES
FURTHER EAST FOR FRIDAY NIGHT AND SATURDAY...HOWEVER WITH THE
VERIFICATION RECORD OF THE ECMWF...THERE IS STILL A CHANCE THE
EASTERN AREAS WILL BE DRY. CONFIDENCE IS LOW ON THE EXACT
LOCATION OF THE WEATHER...BUT HIGHER THAT IT WILL BE AN ACTIVE
FRONTAL ZONE WITH SHRA/ISO TSRA.
THIS QUESTION REMAINS THROUGH MONDAY...HOW FAR EAST WILL THE
FRONTAL BAND BE LOCATED. THE FRONT WILL LIKELY REMAIN ACTIVE WITH
SHOWERS/STORMS AND CLOUDS...AND HIGHS QUITE A BIT COOLER THANOUTSIDE
THE BAND. OVERALL...HAVE INCREASED RAIN CHANCES IN THE WRN/SRN
FORECAST AREA AND TRIED TO REMAIN NEARLY DRY IN THE EAST. SEEMS
LIKE IT WILL BE A CLOUDY WEEKEND...AND THUS HAVE LOWERED HIGHS
SUNDAY AND MONDAY AS WELL. SEVERE WEATHER THREATS ARE MOST
POSSIBLE IN SWRN MN CLOSER TO THE CAPE POOL...AND MONDAY LOOKS
MOST FAVORABLE SHOULD THE INSTABILITY INCREASE AS THE WARM FRONT
MOVES TOWARD MN. HOWEVER...ACTIVITY ALONG THAT FRONT THIS WEEKEND
MAY HAVE MUCH TO DO WITH HOW THE ENVIRONMENT/FRONT EVOLVES MONDAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 415 AM CDT THU MAY 23 2013
THE LONG TERM BEGINS WITH A LARGE HIGH PRESSURE SYSTEM OVER THE
WESTERN GREAT LAKES REGION. MUCH OF FRIDAY WILL BE DRY...WITH THE
EXCEPTION OF THE FAR WEST WHERE STRONG LOW LEVEL THETA-E ADVECTION
WILL COMMENCE IN THE AFTERNOON ON THE BACK SIDE OF THE HIGH. THIS
COUPLED WITH A SHORT WAVE AND MID LEVEL FRONTOGENESIS MOVING EAST
FROM THE NORTHERN PLAINS WILL DRIVE SHOWERS AND ISOLATED
THUNDERSTORMS INTO THE FAR WEST BY LATE AFTERNOON...WITH THE
ACTIVITY PASSING ACROSS THE FA FRIDAY NIGHT AND EARLY SATURDAY.
ELEVATED INSTABILITY IS MINIMAL FRIDAY NIGHT AND SEVERE WEATHER IS
NOT EXPECTED. THE BEST LOW LEVEL MOISTURE TRANSPORT IS AIMED FROM
THE CENTRAL PLAINS INTO IA FRIDAY NIGHT WITH JUST ABOUT ALL MODEL
SOLUTIONS POINTING TO THE HIGHEST QPF STAYING SOUTH OF MN.
IN THE WAKE OF THE SHORT WAVE ON SATURDAY...WE ARE BEGINNING TO SEE
THE NAM AND SREF TAKING ON MORE OF WHAT THE ECMWF HAS BEEN SHOWING
FOR 3 DAYS NOW...AND THAT IS A MORE AMPLIFIED FLOW ALOFT. THIS IS
VERY EVIDENT LOOKING AT THREE RUNS OF THE ECMWF SPACED 24 HOURS
APART. DEEPER UPPER LOWS ALONG BOTH COAST WITH MORE RIDGING IN THE
CENTER OF THE COUNTRY. WITH TIME...THIS BUILDS THE SURFACE HIGH
PRESSURE SYSTEM OVER THE GREAT LAKES BACK WEST ACROSS THE FA ALONG
WITH DRIER AIR. USING THE ECMWF OUTRIGHT WOULD PLACE DRY WEATHER
OVER ALL BUT OUR FAR WESTERN AND SOUTHERN COUNTIES IN MN FOR
SUNDAY AND MONDAY. GOING AGAINST THE GRAIN HOWEVER ARE THE GFS AND
GEM. BOTH ARE ADAMANT ON DRIVING WAVE AFTER WAVE ALOFT THROUGH THE
REGION BOTH DAYS WITH CONVECTIVE CLUSTERS. MODEL RUN QPF IS IN THE
SEVERAL INCH RANGE ACROSS PARTS OF THE MN CWA. ON THE OTHER HAND...
THE ECMWF ONLY HAS A TENTH TO A HALF INCH FROM NORTHEAST TO
SOUTHWEST ACROSS OUR AREA RESPECTIVELY FROM FRIDAY THROUGH
MONDAY. HENCE...THE WEEKEND/HOLIDAY MAY TURN OUT BETTER THAN THE
FORECAST INDICATES IF THE ECMWF IS MORE CORRECT. POPS ARE MORE
ALIGNED NOW WITH VERY LOW CHANCES IN WI WITH HIGHER CHANCES NEAR THE
WESTERN AND SOUTHERN BORDER.
ALTHOUGH THE RAIN CHANCES ARE DIMINISHING AFTER SATURDAY
MORNING...THERE IS GOOD CONSENSUS THAT ABUNDANT LOW LEVEL MOISTURE
WILL COVER THE AREA WITH A WARM FRONT REMAINING SOUTH OF US. THIS
WILL LIKELY YIELD PLENTY OF CLOUD COVER WITH HIGH TEMPERATURES
REMAINING IN THE 60S SATURDAY AND SUNDAY WITH UPPER 60S TO LOWER
70S ON SUNDAY. SHOWERS AND THUNDERSTORMS SHOULD BECOME MORE COMMON
OVER THE REGION FROM TUESDAY ONWARD AS THE TROUGH IN THE WEST
MOVES EAST. THIS WILL LIFT THE LOW PRESSURE SYSTEM AND WARM FRONT
INTO OUT AREA. THIS WILL ALSO INCREASE OUR THREAT FOR SEVERE
WEATHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM CDT THU MAY 23 2013
HIGH PRESSURE AREA BUILDING IN WITH NEARLY CLEAR SKIES/VFR.
LARGEST 3 HOURLY PRESSURE CLIMBS ARE SHIFTING OFF TO THE SOUTHEAST
SO GRADIENT WILL SLACKEN CONSIDERABLY GOING INTO THIS EVENING.
EXPECT ANY LINGERING GUSTS TO CALM DOWN AND WITH RIDGE AXIS
SPREADING THROUGH TONIGHT...GRADUAL SHIFT TO SOUTHEAST LOW LEVEL
FLOW WILL MATERIALIZE GOING INTO FRIDAY MORNING. DRY AIRMASS SHOULD
KEEP SKIES CLEAR THROUGH MOST OF FRIDAY AS WELL.
KMSP...
VFR CONDITIONS TO CONTINUE. NORTHEAST WIND THIS AFTERNOON WILL
DECREASE AND SLOWLY BECOME SOUTHEAST BY FRIDAY MORNING.
/OUTLOOK FOR KMSP/
FRIDAY NIGHT...VFR. CHANCE OF SHOWERS. SOUTHEAST WIND 5 TO 15 KT.
SATURDAY...BRIEF MVFR CEILINGS POSSIBLE WITH A CHANCE OF
SHRA/TSRA. SOUTHEAST WIND 10 TO 20 KT.
SATURDAY NIGHT...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A
CHANCE OF SHRA/TSRA. SOUTHEAST WIND 10 TO 20 KT.
SUNDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE OF
SHRA/TSRA...BRIEF IFR CONDITIONS POSSIBLE. SOUTHEAST WIND 10 TO 20
KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM CDT FRIDAY FOR
WIZ014>016-023>028.
&&
$$
SHORT TERM...BAUMGARDT/ARX
LONG TERM...RAH
AVIATION....SHEA/ARX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
635 PM CDT FRI MAY 24 2013
.AVIATION...
00Z TAFS FOR KOMA...KLNK AND KOFK.
WILL WATCH PCPN CURRENTLY WEST OF KLNK...BUT DID NOT INCLUDE THIS
IN CURRENT TAF. WILL AMEND IF NEEDED. OTHERWISE...FAIRLY LOW
CONFIDENCE FORECAST ON TIMING OF TSRA. OVERALL...EXPECT CONDITIONS
TO DETERIORATE OVERNIGHT AS LOW LEVEL MOISTURE INCREASES. ALL THREE
SITES SHOULD DROP TO MVFR AND POSSIBLY TO IFR. LOOKING AT THE
LATEST 13KM RAP MODEL...EXPECT ACTIVITY CURRENTLY IN SOUTHWEST
NEBRASKA TO TRACK AND DEVELOP NORTHEAST TOWARD KOFK BY 08Z OR
09Z. CHANCES SEEM LOWER AT KLNK AND KOMA UNTIL LATE TONIGHT. THERE
WILL BE SOME CHANCE OF TSRA AT ALL THREE SITES 18Z-00Z TOMORROW
BUT CONFIDENCE WAS TOO LOW TO INCLUDE IN TAFS AT THIS TIME.
MILLER
&&
.PREV DISCUSSION... /ISSUED 252 PM CDT FRI MAY 24 2013/
DISCUSSION...
TIMING OF BEST PRECIPITATION CHANCES THROUGH MEMORIAL DAY WEEKEND
AND BEYOND MAIN CHALLENGE AND CONFIDENCE OF SKILL BEYOND
CLIMATOLOGY...I.E. HIGHEST POPS AT NIGHT...NOT THE HIGHEST.
18Z SURFACE + 12Z UPPER AIR ANALYSIS HAD SURFACE TO 850 MOIST
AXIS AND SUBJECTIVELY PLACED WARM FRONT FM SCNTRL KS INTO SWRN
NEBR. ALTHOUGH A FEW HIGH BASED SHOWERS DEVELOPING NE OF BOUNDARY
IN SCNTRL NEBR AND OTHER POSSIBLE HIGHER BASED ACTIVITY ACROSS
NRN/NERN ZONES EARLY WILL HAVE TO BE MONITORED...MAIN ACTION OVER
THE FORECAST AREA WILL PROBABLY BE FROM LATE THIS EVENING THROUGH
OVERNIGHT HOURS. ANY CONVECTION THAT INCREASES THROUGH THIS
EVENING WRN HIGH PLAINS WILL BE AIDED BY DECENT THETA ADVECTION
INTO BOUNDARY AS LOW LEVEL JET STRENGTHENS. 12Z GFS WAS PROBABLY
SUFFERING FEEDBACK ISSUES BY 12Z SAT IN SRN PLACEMENT OF MCS.
HOWEVER...SOME SRN EXTENSION OF AN MCS COULD MAKE IT INTO FAR
SWRN ZONES EARLY TONIGHT THUS LIKELY POPS ALL OF WRN ZONES JUST
AFT 06Z WITH ANY ACTIVITY THEN FOCUSING MORE ACROSS NERN ZONES SAT
MORNING BEFORE EXPECTED DECLINE.
AFTER TONIGHT DEEPER MOISTURE WILL OVERSPREAD MUCH OF THE
FORECAST AREA WITH MUCH HIGHER THAN NORMAL PRECIPITABLE WATER
VALUES GENERALLY LOCKED IN TILL MUCH OF THE ENERGY FROM WRN U.S.
TROUGH EJECTS LATE NEXT WEEK. WITH MOISTURE/INSTABILITY IN PLACE
AND SOME SORT OF WARM FRONT OR CONVECTIVELY ENHANCED BOUNDARY
POSSIBLY REMAINING OVER OR NEAR AREA...STRENGTHENING NOCTURNAL LOW
LEVEL JET PLUS ANY DISTURBANCES LIFTING OUT OF WRN TROUGH COULD
KEEP ACTIVE PATTERN IN PLACE...ESPECIALLY THROUGH HOLIDAY WEEKEND
AND THEN AGAIN BY NEXT THURSDAY. ALTHOUGH DID TRY TO DIURNALLY
DECREASE CHCS FROM SW TO NE ACROSS AREA ON SATURDAY...AFTER THAT
MADE LITTLE CHANGES TO POPS THROUGH MONDAY...WITH LIKELY POPS
GENERALLY RESERVED FOR NIGHTTIME WITH DECREASED DAYTIME POPS IN
TUE/WED PERIOD.
OVERNIGHT/EARLY SATURDAY CONVECTION COULD REINFORCE BOUNDARY
ACROSS FORECAST AREA SATURDAY...THUS KEPT TEMPS CLOSER TO A 00Z
ECMWF/12Z NAM COMPROMISE NRN AREAS WITH ANY 80+ MENTION CONFINED
TO SOUTHERN ZONES. AFTER MOISTURE BECOMES MORE UNIFORM OVER THE
AREA BEYOND SATURDAY...BETTER SFC THERMAL GRADIENT MAY SHIFT NE
OF AREA THUS PROVIDING MORE UNIFORM TEMPS ALTHOUGH 00Z ECMWF KEPT
SOME BOUNDARY/SLIGHTLY COOLER TEMPS OVER AREA THROUGH MONDAY.
CHERMOK
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 PM EDT THU MAY 23 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE WEST TODAY...LEADING TO
UNSETTLED WEATHER MOST OF THE DAY. AFTER FRONTAL PASSAGE
TONIGHT...THE INTRODUCTION OF CANADIAN HIGH PRESSURE WILL BRING
COOLER AND MORE SETTLED CONDITIONS TO THE REGION THROUGH THE HOLIDAY
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 PM THURSDAY...
UPPER LEVEL TROUGH CONTINUES TO DIG SOUTHWARD THIS AFTERNOON AIDED
BY A 50-75 KNOT UPPER JET OVER THE UPPER MISSISSIPPI VALLEY. THE
SURFACE COLD FRONT IS CURRENTLY MOVING ACROSS CENTRAL TENNESSEE AND
WILL TAKE ITS TIME MOVING ACROSS THE MOUNTAINS THIS EVENING. THE
MAIN 500 MB VORT MAX ASSOCIATED WITH THE FRONT WILL NOT ARRIVE UNTIL
CLOSER TO 00Z. FRONTAL PASSAGE WILL FINALLY OCCUR AFTER 00Z IN THE
NORTHWEST PIEDMONT...CLOSER TO 3Z IN THE TRIANGLE AREA...AND NEAR 6Z
FOR THE I-95 CORRIDOR.
CURRENT RADAR TRENDS SHOW A MYRIAD OF SURFACE BOUNDARIES LEFT OVER
FROM LAST NIGHTS CONVECTION AND DIFFERENTIAL HEATING THIS MORNING.
IN ADDITION A SMALL SHORTWAVE TROUGH IS MOVING NORTHWARD FROM
UPSTATE SOUTH CAROLINA. AT THIS TIME THE BOUNDARY INITIATING THE
MOST CONVECTION SPANS SW TO NE FROM THE ROCKINGHAM AREA TO ROANOKE
RAPIDS. AT THIS TIME INGREDIENTS FOR THUNDERSTORMS ARE A BIT
HEALTHIER THAN IN PREVIOUS DAYS. CURRENTLY THERE IS ABOUT 1000 ML
CAPE IN THE EAST WITH LOW LEVEL LAPSE RATES BETWEEN 7-8. EFFECTIVE
SHEAR IS AROUND 20 KNOTS. RAP SOUNDINGS SHOW VERY TALL SKINNY CAPE
IN THE HAIL GROWTH ZONE MAKING SEVERE HAIL UNLIKELY IN THIS SCENARIO
BUT PEA HAIL IS CERTAINLY POSSIBLE. STRAIGHT HODOGRAPHS WITH 20
KNOTS OF SHEAR SUPPORT A MORE LINEAR MULTICELLULAR CONVECTIVE MODE.
THERE IS A RELATIVELY DRIER LAYER NEAR 800 MB WITH A VERY MODEST
INVERTED V MAKING SEVERE WINDS A LITTLE BIT MORE POSSIBLE THAN IN
PREVIOUS DAYS BUT GUSTS WILL MORE LIKELY TOP OUT IN THE 30-40 KNOT
RANGE. CURRENT SPC ANALYSIS ALSO SHOWS AN AREA OF 500-700 J/KG OF
DCAPE ACROSS THE SOUTH CENTRAL PORTION OF THE CWA. DESPITE
PARAMETERS BEING RELATIVELY BETTER TODAY...MID LEVEL LAPSE RATES ARE
STILL VERY WEAK. OVERALL BULK SHEAR IS LOW. THERE IS ENOUGH LIFT IN
THE MID LEVELS TO SUPPORT MORE LIGHTNING THAN IN PREVIOUS DAYS BUT
ANY SEVERE THREAT WILL BE FAIRLY SUBDUED. AS THE VORT MAX APPROACHES
FROM THE NORTHWEST...DYNAMICS WILL IMPROVE SLIGHTLY AND IF THERE IS
STILL CONVECTION AROUND THE NORTHWEST PIEDMONT WOULD BE THE MOST
LIKELY LOCATION TO SEE SEVERE WEATHER.
WITH SEVERE POTENTIAL LOW...HEAVY RAIN AND FLOODING WILL AGAIN BE
THE LARGEST THREAT. WHILE ONLY A QUARTER TO A HALF OF AN INCH OF
WIDESPREAD PRECIPITATION IS EXPECTED...AREAS RECEIVING HEAVY RAINS
OVER THE PAST FEW DAYS WOULD BE A BIT MORE PRIMED FOR URBAN AND
SMALL STREAM FLOODING. CORFIDI VECTORS SHOW THAT STORMS SHOULD BE
PROGRESSIVE ENOUGH TO AVOID TRAINING BUT ORIENTATION OF INDIVIDUAL
BOUNDARIES COULD ALLOW FOR SOME TRAINING CELLS THIS AFTERNOON.
MOISTURE TRANSPORT...PW VALUES AND SURFACE CONVERGENCE ARE ALL BEST
IN THE COASTAL PLAIN THIS AFTERNOON...MAKING THIS THE MOST LIKELY
LOCATION FOR FLOODING TODAY.
SOUTH SOUTHWESTERLY WINDS TODAY WILL SHIFT TO NORTHWESTERLY AFTER
FRONTAL PASSAGE AND SUSTAINED WINDS WILL ELEVATE TO 10-15 KNOTS.
HIGHS TODAY WILL BE LARGELY DEPENDENT UPON CONVECTION AND CLOUD
COVER BUT IN GENERAL...UPPER 70S TO NEAR 80 IN THE NW AND LOWER TO
MID 80S IN THE SOUTH. LOWS WILL BE DEPENDENT UPON THE TIMING OF THE
FRONTAL PASSAGE UPPER 50S TO NEAR 60 IN THE NW AND MID 60S SE. SOME
MVFR CEILINGS OR VISIBILITIES COULD BE POSSIBLE IN THE EAST BEFORE
MAIN FRONT MOVES THROUGH EARLY FRIDAY MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 240 PM THURSDAY...
FRIDAY AND FRIDAY NIGHT...
THE COLD FRONT WILL SLOWLY MOVE OUT OF THE EASTERN AREAS OF THE CWA
DURING THE EARLY MORNING. AFTER FRONTAL PASSAGE WINDS WILL SHIFT TO
NORTHWESTERLY AND INCREASE IN SPEED TO 15 KNOTS SUSTAINED. A VERY
TALL MIXED LAYER DURING THE AFTERNOON AND THE PASSAGE OF A 30 KNOT
850 JET WILL HELP TRANSPORT SOME OF THOSE WINDS DOWN TO THE SURFACE
AND GUSTS OF 25-30 KNOTS ARE POSSIBLE FRIDAY AFTERNOON. SKIES WILL
GRADUALLY CLEAR OUT AND THICKNESSES SUPPORT HIGH TEMPERATURES IN THE
MID 70S IN MOST LOCATIONS. ON FRIDAY NIGHT WINDS WILL REMAIN
BLUSTERY WHICH WILL HELP TO OFFSET RADIATIONAL COOLING A BIT AS
THICKNESSES SUPPORT LOWS NEAR 40 DEGREES BUT WILL GO A BIT
CONSERVATIVE IN THE LOWER 40S. STILL VERY POSSIBLE TO BREAK THE LOW
TEMPERATURE RECORDS AT BOTH RDU AND GSO WHICH ARE BOTH 43 DEGREES.
-ELLIS
SATURDAY THROUGH SUNDAY NIGHT...
A DEEP UPPER LEVEL LOW WILL DRIFT NWD ALONG THE NORTHERN MID
ATLANTIC AND NEW ENGLAND COAST THROUGH SUNDAY. DUE TO THE EXTENSIVE
CIRCULATION ASSOCIATED WITH THIS SYSTEM IN TANDEM WITH AN AMPLIFYING
RIDGE OVER THE CENTRAL U.S....THE FLOW ALOFT ACROSS CENTRAL NC WILL
BE NWLY. AT THE SURFACE...COOL CANADIAN HIGH PRESSURE WILL BUILD
SEWD FROM THE GREAT LAKES INTO THE CAROLINAS. THE DEEP N-NW FLOW
WILL RESULT IN A DRY AND COOL HOLIDAY WEEKEND. THICKNESSES SATURDAY
AFTERNOON IN THE 1360S...SOME 30-35M BELOW NORMAL AND SUPPORTIVE OF
TEMPS UPPER 60S TO NEAR 70. ALLOWING FOR THE WARMTH OF A LATE MAY
SUN...FAVOR TEMPS IN THE LOW-MID 70S.
TEMPS WILL COOL OFF QUICKLY SATURDAY EVENING THEN STABILIZE AS MODEL
RH CROSS SECTIONS SUGGEST INCREASING MID-HIGH LEVEL CLOUDINESS AFTER
MIDNIGHT. THESE CLOUDS ASSOCIATED WITH DISTURBANCES IN THE NW FLOW
ALOFT. THIS TYPE OF PATTERN SUPPORTIVE OF OROGRAPHIC ENHANCED
CLOUDINESS...SO THE USUALLY TOO WET GFS MAY BE ONTO SOMETHING. THE
ARRIVAL OF THESE CLOUDS WILL PLAY A ROLE IN DETERMINING MIN TEMPS.
FAVOR COOLEST TEMPS NE WHERE CLOUDS WILL BE LESS/THINNER COMPARED TO
THE WEST-SW. IF CLOUDS ARE SLOW TO ARRIVE OR THIN...MIN TEMPS MAY
END UP BEING 2-3 DEGREES COOLER THAN FORECAST.
MODEST WARM UP EXPECTED SUNDAY AS THICKNESSES RECOVER INTO THE
1370S/LOW 1380S. EXPECT AFTERNOON TEMPS IN THE MID-UPPER 70S UNDER
PARTLY-MOSTLY SUNNY SKIES. SUNDAY NIGHT SHOULD BE A LITTLE MILDER AS
AIR MASS CONTINUES TO MODIFY. MOS GUIDANCE APPEARS TOO WARM BY A
CATEGORY. FAVOR MIN TEMPS NEAR 50 COOLER SPOTS TO LOW-MID 50S
ELSEWHERE. -WSS
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM THURSDAY...
12Z GFS TRENDING TOWARD THE 00Z ECMWF. THE ECMWF HELD ONTO THE L/W
TROUGH ALONG THE EASTERN SEABOARD RESULTING IN A SLOWER WARMING
TREND WHERE AS THE GFS WITH ITS BUILDING MID-UPPER HEIGHTS
ADVERTISES A QUICKER/MORE NOTABLE WARM-UP. THE ECMWF SOLUTION OF A
LINGERING TROUGH NEAR OR OFFSHORE OF THE NEW ENGLAND COAST AND AN
AMPLIFYING RIDGE OVER THE MS RIVER VALLEY WILL MAINTAIN A NW FLOW
ALOFT OVER CENTRAL NC. THE ECMWF HINTS AT POSSIBLE DISTURBANCES
ASSOCIATED WITH MCS ACTIVITY THAT MAY OCCUR IN THE UPPER MID
WEST/GREAT LAKES TUESDAY-THURSDAY CROSSING OUR REGION. IF THIS WERE
TO OCCUR...COULD SEE A PERIOD OF UNSETTLED WEATHER ANYTIME BETWEEN
WEDNESDAY-THURSDAY. IF GFS WERE TO VERIFY WITH THE RIDGE BUILDING
CLOSER TO HOME...MCS ACTIVITY WILL BE SHUNTED MORE TO OUR NORTH. FOR
NOW...WILL KEEP POPS NO HIGHER THAN 20 PERCENT TUESDAY INTO
THURSDAY. LOW LEVEL THICKNESSES RETURN TO NEAR OR SLIGHTLY ABOVE
NORMAL VALUES TUESDAY ONWARD. WILL HAVE AFTERNOON TEMPS NEAR 80-LOWER
80S TUESDAY...AND LOW-MID 80S WEDNESDAY/THURSDAY. AGAIN...IF GFS
VERIFIES...WED/THU COULD SEE TEMPS IN THE UPPER 80S TO NEAR 90.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 140 PM THURSDAY...
24 HOUR TAF PERIOD: COMPLICATED LOW CONFIDENCE FORECAST FOR THIS
AFTERNOON. SEVERAL OUTFLOW AND DIFFERENTIAL HEATING BOUNDARIES HAVE
SET UP ACROSS CENTRAL NORTH CAROLINA THIS AFTERNOON. APPROACHING
FROM THE SOUTHWEST IS A SHORTWAVE TROUGH THAT WAS LOCATED OVER
NORTHERN GA THIS MORNING. ALL OF THESE SURFACE BOUNDARIES WILL BE
FOCI FOR THE GENESIS OF SHOWERS AND STORMS THIS AFTERNOON. THE MOST
PROMINENT BOUNDARY AT THIS TIME IS BISECTING THE CWA FROM SW TO NE
AND WILL BE AFFECTING KFAY AND KRWI IN THE NEXT COUPLE OF HOURS.
HEAVY RAIN AND GUSTY WINDS ARE LIKELY WITH THESE STORMS ALONG WITH
IFR/MVFR CEILINGS AND VISIBILITIES. OTHERWISE VFR CONDITIONS WILL
PREVAIL OUTSIDE OF STORMS WITH WINDS OUT OF THE SOUTH SOUTHWEST AT
5-10 KNOTS. LATER THIS AFTERNOON A MORE CONCENTRATED LINE OF SHOWERS
AND STORMS ASSOCIATED WITH THE PRE-FRONTAL TROUGH WILL MAKE THEIR
WAY ACROSS THE AREA WITH THE TRIAD TERMINALS AFFECTED JUST BEFORE
0Z. THIS LINE WILL SLOWLY PROGRESS EASTWARD GETTING TO KRDU AND KFAY
IN THE VICINITY OF 3Z AND KRWI CLOSER TO 6Z.
FOR FRIDAY CONDITIONS WILL RETURN TO VFR BUT STRONG GUSTY WINDS WILL
BE THE PROBLEM OF THE DAY WITH 15-20 KNOTS SUSTAINED OUT OF THE
NORTHWEST GUSTING TO 25-30 KNOTS. SKIES WILL GRADUALLY CLEAR
THROUGHOUT THE DAY.
LONG TERM: SATURDAY WILL SEE A PROLONGED RETURN TO VFR CONDITIONS
THROUGH MONDAY MAKING CONDITIONS VERY FAVORABLE FOR GENERAL AVIATION
THROUGH THE EXTENDED MEMORIAL DAY WEEKEND.
&&
.CLIMATE...
MORNING LOW TEMPERATURES ON THE 25TH AND 26TH ARE EXPECTED TO BE
NEAR RECORD MIN TEMPS FOR THE DATE.
RECORD MIN TEMP/YEAR SET MAY 25TH MAY 26TH
RDU 43 / 1967 43 / 1979
GSO 43 / 1956 42 / 1930
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ELLIS
NEAR TERM...ELLIS
SHORT TERM...ELLIS/WSS
LONG TERM...WSS
AVIATION...ELLIS
CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
242 PM EDT THU MAY 23 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE WEST TODAY...LEADING TO
UNSETTLED WEATHER MOST OF THE DAY. AFTER FRONTAL PASSAGE
TONIGHT...THE INTRODUCTION OF CANADIAN HIGH PRESSURE WILL BRING
COOLER AND MORE SETTLED CONDITIONS TO THE REGION THROUGH THE HOLIDAY
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 PM THURSDAY...
UPPER LEVEL TROUGH CONTINUES TO DIG SOUTHWARD THIS AFTERNOON AIDED
BY A 50-75 KNOT UPPER JET OVER THE UPPER MISSISSIPPI VALLEY. THE
SURFACE COLD FRONT IS CURRENTLY MOVING ACROSS CENTRAL TENNESSEE AND
WILL TAKE ITS TIME MOVING ACROSS THE MOUNTAINS THIS EVENING. THE
MAIN 500 MB VORT MAX ASSOCIATED WITH THE FRONT WILL NOT ARRIVE UNTIL
CLOSER TO 00Z. FRONTAL PASSAGE WILL FINALLY OCCUR AFTER 00Z IN THE
NORTHWEST PIEDMONT...CLOSER TO 3Z IN THE TRIANGLE AREA...AND NEAR 6Z
FOR THE I-95 CORRIDOR.
CURRENT RADAR TRENDS SHOW A MYRIAD OF SURFACE BOUNDARIES LEFT OVER
FROM LAST NIGHTS CONVECTION AND DIFFERENTIAL HEATING THIS MORNING.
IN ADDITION A SMALL SHORTWAVE TROUGH IS MOVING NORTHWARD FROM
UPSTATE SOUTH CAROLINA. AT THIS TIME THE BOUNDARY INITIATING THE
MOST CONVECTION SPANS SW TO NE FROM THE ROCKINGHAM AREA TO ROANOKE
RAPIDS. AT THIS TIME INGREDIENTS FOR THUNDERSTORMS ARE A BIT
HEALTHIER THAN IN PREVIOUS DAYS. CURRENTLY THERE IS ABOUT 1000 ML
CAPE IN THE EAST WITH LOW LEVEL LAPSE RATES BETWEEN 7-8. EFFECTIVE
SHEAR IS AROUND 20 KNOTS. RAP SOUNDINGS SHOW VERY TALL SKINNY CAPE
IN THE HAIL GROWTH ZONE MAKING SEVERE HAIL UNLIKELY IN THIS SCENARIO
BUT PEA HAIL IS CERTAINLY POSSIBLE. STRAIGHT HODOGRAPHS WITH 20
KNOTS OF SHEAR SUPPORT A MORE LINEAR MULTICELLULAR CONVECTIVE MODE.
THERE IS A RELATIVELY DRIER LAYER NEAR 800 MB WITH A VERY MODEST
INVERTED V MAKING SEVERE WINDS A LITTLE BIT MORE POSSIBLE THAN IN
PREVIOUS DAYS BUT GUSTS WILL MORE LIKELY TOP OUT IN THE 30-40 KNOT
RANGE. CURRENT SPC ANALYSIS ALSO SHOWS AN AREA OF 500-700 J/KG OF
DCAPE ACROSS THE SOUTH CENTRAL PORTION OF THE CWA. DESPITE
PARAMETERS BEING RELATIVELY BETTER TODAY...MID LEVEL LAPSE RATES ARE
STILL VERY WEAK. OVERALL BULK SHEAR IS LOW. THERE IS ENOUGH LIFT IN
THE MID LEVELS TO SUPPORT MORE LIGHTNING THAN IN PREVIOUS DAYS BUT
ANY SEVERE THREAT WILL BE FAIRLY SUBDUED. AS THE VORT MAX APPROACHES
FROM THE NORTHWEST...DYNAMICS WILL IMPROVE SLIGHTLY AND IF THERE IS
STILL CONVECTION AROUND THE NORTHWEST PIEDMONT WOULD BE THE MOST
LIKELY LOCATION TO SEE SEVERE WEATHER.
WITH SEVERE POTENTIAL LOW...HEAVY RAIN AND FLOODING WILL AGAIN BE
THE LARGEST THREAT. WHILE ONLY A QUARTER TO A HALF OF AN INCH OF
WIDESPREAD PRECIPITATION IS EXPECTED...AREAS RECEIVING HEAVY RAINS
OVER THE PAST FEW DAYS WOULD BE A BIT MORE PRIMED FOR URBAN AND
SMALL STREAM FLOODING. CORFIDI VECTORS SHOW THAT STORMS SHOULD BE
PROGRESSIVE ENOUGH TO AVOID TRAINING BUT ORIENTATION OF INDIVIDUAL
BOUNDARIES COULD ALLOW FOR SOME TRAINING CELLS THIS AFTERNOON.
MOISTURE TRANSPORT...PW VALUES AND SURFACE CONVERGENCE ARE ALL BEST
IN THE COASTAL PLAIN THIS AFTERNOON...MAKING THIS THE MOST LIKELY
LOCATION FOR FLOODING TODAY.
SOUTH SOUTHWESTERLY WINDS TODAY WILL SHIFT TO NORTHWESTERLY AFTER
FRONTAL PASSAGE AND SUSTAINED WINDS WILL ELEVATE TO 10-15 KNOTS.
HIGHS TODAY WILL BE LARGELY DEPENDENT UPON CONVECTION AND CLOUD
COVER BUT IN GENERAL...UPPER 70S TO NEAR 80 IN THE NW AND LOWER TO
MID 80S IN THE SOUTH. LOWS WILL BE DEPENDENT UPON THE TIMING OF THE
FRONTAL PASSAGE UPPER 50S TO NEAR 60 IN THE NW AND MID 60S SE. SOME
MVFR CEILINGS OR VISIBILITIES COULD BE POSSIBLE IN THE EAST BEFORE
MAIN FRONT MOVES THROUGH EARLY FRIDAY MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 240 PM THURSDAY...
FRIDAY AND FRIDAY NIGHT...
THE COLD FRONT WILL SLOWLY MOVE OUT OF THE EASTERN AREAS OF THE CWA
DURING THE EARLY MORNING. AFTER FRONTAL PASSAGE WINDS WILL SHIFT TO
NORTHWESTERLY AND INCREASE IN SPEED TO 15 KNOTS SUSTAINED. A VERY
TALL MIXED LAYER DURING THE AFTERNOON AND THE PASSAGE OF A 30 KNOT
850 JET WILL HELP TRANSPORT SOME OF THOSE WINDS DOWN TO THE SURFACE
AND GUSTS OF 25-30 KNOTS ARE POSSIBLE FRIDAY AFTERNOON. SKIES WILL
GRADUALLY CLEAR OUT AND THICKNESSES SUPPORT HIGH TEMPERATURES IN THE
MID 70S IN MOST LOCATIONS. ON FRIDAY NIGHT WINDS WILL REMAIN
BLUSTERY WHICH WILL HELP TO OFFSET RADIATIONAL COOLING A BIT AS
THICKNESSES SUPPORT LOWS NEAR 40 DEGREES BUT WILL GO A BIT
CONSERVATIVE IN THE LOWER 40S. STILL VERY POSSIBLE TO BREAK THE LOW
TEMPERATURE RECORDS AT BOTH RDU AND GSO WHICH ARE BOTH 43 DEGREES.
-ELLIS
SATURDAY THROUGH SUNDAY NIGHT...
A DEEP UPPER LEVEL LOW WILL DRIFT NWD ALONG THE NORTHERN MID
ATLANTIC AND NEW ENGLAND COAST THROUGH SUNDAY. DUE TO THE EXTENSIVE
CIRCULATION ASSOCIATED WITH THIS SYSTEM IN TANDEM WITH AN AMPLIFYING
RIDGE OVER THE CENTRAL U.S....THE FLOW ALOFT ACROSS CENTRAL NC WILL
BE NWLY. AT THE SURFACE...COOL CANADIAN HIGH PRESSURE WILL BUILD
SEWD FROM THE GREAT LAKES INTO THE CAROLINAS. THE DEEP N-NW FLOW
WILL RESULT IN A DRY AND COOL HOLIDAY WEEKEND. THICKNESSES SATURDAY
AFTERNOON IN THE 1360S...SOME 30-35M BELOW NORMAL AND SUPPORTIVE OF
TEMPS UPPER 60S TO NEAR 70. ALLOWING FOR THE WARMTH OF A LATE MAY
SUN...FAVOR TEMPS IN THE LOW-MID 70S.
TEMPS WILL COOL OFF QUICKLY SATURDAY EVENING THEN STABILIZE AS MODEL
RH CROSS SECTIONS SUGGEST INCREASING MID-HIGH LEVEL CLOUDINESS AFTER
MIDNIGHT. THESE CLOUDS ASSOCIATED WITH DISTURBANCES IN THE NW FLOW
ALOFT. THIS TYPE OF PATTERN SUPPORTIVE OF OROGRAPHIC ENHANCED
CLOUDINESS...SO THE USUALLY TOO WET GFS MAY BE ONTO SOMETHING. THE
ARRIVAL OF THESE CLOUDS WILL PLAY A ROLE IN DETERMINING MIN TEMPS.
FAVOR COOLEST TEMPS NE WHERE CLOUDS WILL BE LESS/THINNER COMPARED TO
THE WEST-SW. IF CLOUDS ARE SLOW TO ARRIVE OR THIN...MIN TEMPS MAY
END UP BEING 2-3 DEGREES COOLER THAN FORECAST.
MODEST WARM UP EXPECTED SUNDAY AS THICKNESSES RECOVER INTO THE
1370S/LOW 1380S. EXPECT AFTERNOON TEMPS IN THE MID-UPPER 70S UNDER
PARTLY-MOSTLY SUNNY SKIES. SUNDAY NIGHT SHOULD BE A LITTLE MILDER AS
AIR MASS CONTINUES TO MODIFY. MOS GUIDANCE APPEARS TOO WARM BY A
CATEGORY. FAVOR MIN TEMPS NEAR 50 COOLER SPOTS TO LOW-MID 50S
ELSEWHERE. -WSS
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 255 AM THURSDAY...
SATURDAY AND SUNDAY...
A TERRIFIC WEEKEND IS SHAPING UP AS CANADIAN HIGH PRESSURE WILL
BUILD SOUTH OUT OF THE GREAT LAKES INTO THE EASTERN CONUS. THIS WILL
RESULT IN CLEAR SKIES SATURDAY WITH DRY AND COOLER AIR IN PLACE.
UPPER FLOW WILL BE NORTHWEST AND MODEL CROSS SECTIONS SHOW THAT SOME
HIGH CLOUDINESS COULD MILDLY IMPEDE THE SUNSHINE ON SUNDAY. HIGHS
BOTH DAYS WILL BE MOSTLY IN THE MID 70S. MEANWHILE... SUNDAY
MORNINGS LOW TEMPERATURE WILL BE CONSIDERABLY BELOW NORMAL DUE TO
EXCELLENT RADIATIONAL CONDITIONS...IN THE 45 TO 50 DEGREE RANGE.
MONDAY THROUGH WEDNESDAY....
THE SURFACE HIGH PRESSURE MIGRATES OFFSHORE EARLY NEXT WEEK WHICH
WILL RESULT IN A GRADUAL WARMER AND MOISTER TREND INTO MIDWEEK. WE
WILL BE UNDER A BUILDING LOW AMPLITUDE UPPER RIDGE THROUGH THE
PERIOD WHICH WILL TEND TO SUPPRESS CONVECTION...ESPECIALLY WITH NO
EASILY IDENTIFIABLE FORCING OTHER THAN GENERALLY INCREASING
INSTABILITY WITH LEE TROFFING IN NORTHWEST FLOW AND POTENTIAL FOR
SOME INLAND PENETRATION OF SEA BREEZE CONVECTION IN THE EAST. AS
SUCH...WILL NOT MEDDLE WITH ONGOING SLIGHT CHANCE FOR LATE DAY
CONVECTION MONDAY THROUGH WEDNESDAY. TEMPS WILL BE ON THE UPTICK...
FROM 75 TO 80 ON MONDAY RISING TO 80 TO 85 ON WEDNESDAY...WITH MINS
FOLLOWING A SIMILAR TREND...FROM THE MID 50S MONDAY MORNING TO THE
LOWER 60S WEDNESDAY MORNING.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 140 PM THURSDAY...
24 HOUR TAF PERIOD: COMPLICATED LOW CONFIDENCE FORECAST FOR THIS
AFTERNOON. SEVERAL OUTFLOW AND DIFFERENTIAL HEATING BOUNDARIES HAVE
SET UP ACROSS CENTRAL NORTH CAROLINA THIS AFTERNOON. APPROACHING
FROM THE SOUTHWEST IS A SHORTWAVE TROUGH THAT WAS LOCATED OVER
NORTHERN GA THIS MORNING. ALL OF THESE SURFACE BOUNDARIES WILL BE
FOCI FOR THE GENESIS OF SHOWERS AND STORMS THIS AFTERNOON. THE MOST
PROMINENT BOUNDARY AT THIS TIME IS BISECTING THE CWA FROM SW TO NE
AND WILL BE AFFECTING KFAY AND KRWI IN THE NEXT COUPLE OF HOURS.
HEAVY RAIN AND GUSTY WINDS ARE LIKELY WITH THESE STORMS ALONG WITH
IFR/MVFR CEILINGS AND VISIBILITIES. OTHERWISE VFR CONDITIONS WILL
PREVAIL OUTSIDE OF STORMS WITH WINDS OUT OF THE SOUTH SOUTHWEST AT
5-10 KNOTS. LATER THIS AFTERNOON A MORE CONCENTRATED LINE OF SHOWERS
AND STORMS ASSOCIATED WITH THE PRE-FRONTAL TROUGH WILL MAKE THEIR
WAY ACROSS THE AREA WITH THE TRIAD TERMINALS AFFECTED JUST BEFORE
0Z. THIS LINE WILL SLOWLY PROGRESS EASTWARD GETTING TO KRDU AND KFAY
IN THE VICINITY OF 3Z AND KRWI CLOSER TO 6Z.
FOR FRIDAY CONDITIONS WILL RETURN TO VFR BUT STRONG GUSTY WINDS WILL
BE THE PROBLEM OF THE DAY WITH 15-20 KNOTS SUSTAINED OUT OF THE
NORTHWEST GUSTING TO 25-30 KNOTS. SKIES WILL GRADUALLY CLEAR
THROUGHOUT THE DAY.
LONG TERM: SATURDAY WILL SEE A PROLONGED RETURN TO VFR CONDITIONS
THROUGH MONDAY MAKING CONDITIONS VERY FAVORABLE FOR GENERAL AVIATION
THROUGH THE EXTENDED MEMORIAL DAY WEEKEND.
&&
.CLIMATE...
MORNING LOW TEMPERATURES ON THE 25TH AND 26TH ARE EXPECTED TO BE
NEAR RECORD MIN TEMPS FOR THE DATE.
RECORD MIN TEMP/YEAR SET MAY 25TH MAY 26TH
RDU 43 / 1967 43 / 1979
GSO 43 / 1956 42 / 1930
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ELLIS
NEAR TERM...ELLIS
SHORT TERM...ELLIS/WSS
LONG TERM...MLM
AVIATION...ELLIS
CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
255 AM EDT THU MAY 23 2013
.SYNOPSIS...
A TROUGH ALOFT AND ACCOMPANYING PRE-FRONTAL SURFACE PRESSURE TROUGH
WILL SETTLE INTO CENTRAL NC TODAY...FOLLOWED BY THE PASSAGE OF A
COLD FRONT TONIGHT. CANADIAN HIGH PRESSURE WILL THEN EXPAND ACROSS
OUR REGION THROUGH THE HOLIDAY WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1010 PM WEDNESDAY...
ANY SHOWERS AND THUNDERSTORMS FROM THIS AFTERNOON AND EVENING
ASSOCIATED WITH THE SEA BREEZE AND OUTFLOW ACROSS THE EASTERN
TWO-THIRDS OF THE AREA HAVE DISSIPATED WITH THE LOSS OF DAYTIME
HEATING AND RESULTANT STABILIZING BOUNDARY LAYER. CONVECTION THAT
FIRED ACROSS THE HIGHER TERRAIN TODAY... HAS GENERALLY STAYED TO THE
WEST OF THE REGION WITH A 15 TO 20 KT SOUTH-SOUTHWESTERLY MEAN
STEERING FLOW. HOWEVER... A WEST-NORTHWESTERLY OUTFLOW... GENERATED
FROM THESE CLUSTERS OF SHOWERS AND STORMS THAT ORIGINATED ALONG THE
HIGHER TERRAIN... HAS FINALLY ALLOWED FOR THE DEVELOPMENT OF SHOWERS
AND STORMS ACROSS OUR FAR NORTHWESTERN REACHES OF OUR CWA... ALONG
THE OUTFLOW. THINK THIS OUTFLOW SHOULD SUPPORT AT LEAST SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ACROSS OUR WESTERN PIEDMONT
THROUGH 06/07Z... GIVEN 500 TO 1000 J/KG OF SURFACE BASED CAPE.
THEREAFTER... EXPECT BOUNDARY LAYER COOLING SHOULD YIELD A TREND TO
ISOLATED SHOWERS AT BEST. ANY SIGNIFICANT S/W ENERGY ROTATING
THROUGH THE CYCLONIC FLOW ALOFT FROM THE APPROACHING MID LEVEL
TROUGH WELL TO THE WEST OF THE AREA... INVOF THE MS RIVER THIS
EVENING... IS EXPECTED TO PASS TO THE WEST AND NORTH OF THE REGION
THUS... PLAN TO TRIM POPS TO SLIGHT CHANCE BY EARLY THURSDAY MORNING
ACROSS THE ENTIRE CWA. THIS IS SUPPORTED BY THE LATEST HRRR.
HOWEVER... ITS WORTH NOTING THE LATEST HRRR DOES SHOW SOME SHOWERS
CURRENTLY OFF THE CAROLINA COAST MOVING ONSHORE OVERNIGHT ACROSS THE
COASTAL PLAIN. CURRENT HI-RES MODELS GENERALLY SHOW THIS PRECIP
REMAINING JUST TO THE EAST OF OUR AREA. THUS... WILL KEEP ONLY
SLIGHT CHANCE POPS ACROSS OUR EAST AS WELL. OVERNIGHT LOWS IN THE
MID TO UPPER 60S ARE STILL EXPECTED... WITH GENERALLY PATCHY FOG
(FOG... AT LOCATIONS THAT ARE PICKING UP DECENT SHOWERS/STORMS
ACROSS THE TRIAD NOW) AND WIDESPREAD LOW STATUS.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 300 PM WEDNESDAY...
A COLD FRONT WILL APPROACH CENTRAL NC FROM THE WEST ON FRIDAY. AS A
DEEP 500 MB TROUGH DIGS SOUTHWARD THROUGH THE OHIO VALLEY. AS FAR AS
TIMING IS CONCERNED...SHOWERS AND THUNDERSTORMS AHEAD OF FRONT WILL
BEGIN TO AFFECT THE TRIAD BY LATE THURSDAY MORNING AND CONTINUE TO
PROGRESS SLOWLY EASTWARD ACROSS THE CWA BY AFTERNOON/EVENING. SEVERE
POTENTIAL WITH THIS SYSTEM WILL BE GREATER THAN THE PAST COUPLE OF
DAYS BUT STILL LOOKS VERY LOW. EFFECTIVE SHEAR WILL BE ABOUT 20
KNOTS SUGGESTING MORE LINEAR THUNDERSTORMS. THIS IS SUPPORTED BY THE
STRAIGHT HODOGRAPHS SHOWN BY NAM FORECAST SOUNDINGS. MID LEVEL LAPSE
RATES WILL BE WEEK ALTHOUGH 1000 ML CAPE OF THE TALL AND SKINNY
VARIETY COULD BE REALIZED BY AFTERNOON. LATER IN THE EVENT DYNAMICS
IMPROVE AS A 30 KNOT 850MB APPROACHES THE NORTHWEST. IT IS UNCLEAR
AT THIS TIME WHETHER OR NOT CONVECTION WILL BE TOO FAR TO THE EAST
TO TAKE ADVANTAGE OF THE INCREASED SHEAR. STORMS LINGERING BACK
TOWARDS THE WEST MAY BE ABLE TO TAKE ADVANTAGE OF AN INCREASED AXIS
OF DCAPE EXPECTED TO MOVE THROUGH THE CWA JUST AFTER 00Z FRIDAY.
THEREFORE IF WE DO ENCOUNTER SEVERE WEATHER TOMORROW...IT WILL MOST
LIKELY BE DAMAGING WINDS AND NOT HAIL. FOR NOW SPC HAS KEPT THE
RALEIGH AREA OUT OF THE SLIGHT RISK AREA FOR TOMORROW. PRECIPITABLE
WATERS WILL BE SIMILAR TO TODAY NEAR 1.5 INCHES BUT QPF WITH FRONTAL
PASSAGE IS ONLY EXPECTED TO BE BETWEEN A QUARTER AND A HALF OF AN
INCH WITH LOCALLY HEAVIER AMOUNTS POSSIBLE IN THUNDERSTORMS.
LOCALIZED FLOODING COULD BE AN ISSUE...ESPECIALLY IN URBAN AREAS
UNDER SLOW MOVING OR TRAINING THUNDERSTORMS. CLOUD COVER SHOULD
OVERSPREAD THE AREA FAIRLY EARLY TOMORROW AND THUS WILL TREND
TOWARDS THE COOLER MET GUIDANCE WITH HIGH TEMPERATURES. UPPER 70S IN
THE NORTHWEST TO LOW 80S SOUTHEAST. AS THE LOWER ATMOSPHERE BEGINS
TO DRY OUT LOW TEMPERATURES IN THE TRIAD SHOULD DIP INTO THE UPPER
50S IN THE NORTHWEST FOR THE FIRST TIME IN SEVERAL DAYS BUT FURTHER
TO THE SOUTHEAST LOWS WILL REMAIN IN THE MIDDLE 60S AS THE FRONT IS
EXPECTED TO FULLY MOVE THROUGH THE EAST UNTIL CLOSER TO 6Z ON FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 255 AM THURSDAY...
SATURDAY AND SUNDAY...
A TERRIFIC WEEKEND IS SHAPING UP AS CANADIAN HIGH PRESSURE WILL
BUILD SOUTH OUT OF THE GREAT LAKES INTO THE EASTERN CONUS. THIS WILL
RESULT IN CLEAR SKIES SATURDAY WITH DRY AND COOLER AIR IN PLACE.
UPPER FLOW WILL BE NORTHWEST AND MODEL CROSS SECTIONS SHOW THAT SOME
HIGH CLOUDINESS COULD MILDLY IMPEDE THE SUNSHINE ON SUNDAY. HIGHS
BOTH DAYS WILL BE MOSTLY IN THE MID 70S. MEANWHILE... SUNDAY
MORNINGS LOW TEMPERATURE WILL BE CONSIDERABLY BELOW NORMAL DUE TO
EXCELLENT RADIATIONAL CONDITIONS...IN THE 45 TO 50 DEGREE RANGE.
MONDAY THROUGH WEDNESDAY....
THE SURFACE HIGH PRESSURE MIGRATES OFFSHORE EARLY NEXT WEEK WHICH
WILL RESULT IN A GRADUAL WARMER AND MOISTER TREND INTO MIDWEEK. WE
WILL BE UNDER A BUILDING LOW AMPLITUDE UPPER RIDGE THROUGH THE
PERIOD WHICH WILL TEND TO SUPPRESS CONVECTION...ESPECIALLY WITH NO
EASILY IDENTIFIABLE FORCING OTHER THAN GENERALLY INCREASING
INSTABILITY WITH LEE TROFFING IN NORTHWEST FLOW AND POTENTIAL FOR
SOME INLAND PENETRATION OF SEA BREEZE CONVECTION IN THE EAST. AS
SUCH...WILL NOT MEDDLE WITH ONGOING SLIGHT CHANCE FOR LATE DAY
CONVECTION MONDAY THROUGH WEDNESDAY. TEMPS WILL BE ON THE UPTICK...
FROM 75 TO 80 ON MONDAY RISING TO 80 TO 85 ON WEDNESDAY...WITH MINS
FOLLOWING A SIMILAR TREND...FROM THE MID 50S MONDAY MORNING TO THE
LOWER 60S WEDNESDAY MORNING.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 205 AM THURSDAY...
A LINE OF SHOWERS AND ISOLATED STORMS THAT EARLIER AFFECTED THE
TRIAD TERMINALS WILL CONTINUE TO MOVE SLOWLY EASTWARD AT AROUND 10
MPH...AFFECTING THE KRDU AREA BETWEEN 8-10Z. A GRADUAL
WEAKENING/DISSIPATING TREND SHOULD OCCUR AS THE AIR MASS CONTINUES
TO STABILIZE WITH NOCTURNAL COOLING...HOWEVER...SO CONFIDENCE OF THE
CONVECTION REACHING THE KFAY AND KRWI AREAS IS LOW. OTHERWISE...A
CONTINUED MOIST AIR MASS WILL PROMOTE A HIGH CHANCE OF LIFR-IFR
CEILINGS THIS MORNING...THOUGH WITH RELATIVE LOWEST CHANCES - AROUND
60 PERCENT - AT TRIAD TERMINALS. THESE CEILINGS WILL LIFT AND
SCATTER TO VFR WITH HEATING THROUGH MIDDAY. HEATING OF THE MOIST AIR
MASS WILL ALSO CAUSE SCATTERED TO NUMEROUS SHOWERS AND STORMS TO
DEVELOP THIS AFTERNOON...AND THESE WILL LIKELY CONTINUE UNTIL A COLD
FRONT SWEEPS ACROSS CENTRAL NC FROM WEST TO EAST BETWEEN 04-06Z AT
TRIAD TERMINALS...TO 09-12Z AT EASTERN ONES. AREAS O FOG OR LOW
STRATUS WILL ALSO BE POSSIBLE AHEAD OF THE COLD FRONT...MOST LIKELY
AT KFAY AND KRWI BETWEEN 06-12Z.
VFR CONDITIONS WILL OTHERWISE PREVAIL IN CANADIAN HIGH PRESSURE
THROUGH THE HOLIDAY WEEKEND.
&&
.CLIMATE...
MORNING LOW TEMPERATURES ON THE 25TH AND 26TH ARE EXPECTED TO BE A
FEW DEGREES SHY OF RECORD MIN TEMPS FOR THE DATE.
RECORD MIN TEMP/YEAR SET MAY 25TH MAY 26TH
RDU 43 / 1967 43 / 1979
GSO 43 / 1956 42 / 1930
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...BSD
SHORT TERM...ELLIS
LONG TERM...MLM
AVIATION...MWS
CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
208 AM EDT THU MAY 23 2013
.SYNOPSIS...
A TROUGH ALOFT AND ACCOMPANYING PRE-FRONTAL SURFACE PRESSURE TROUGH
WILL MOVE INTO CENTRAL NC TODAY...FOLLOWED BY THE PASSAGE OF A COLD
FRONT TONIGHT. CANADIAN HIGH PRESSURE WILL THEN EXPAND ACROSS OUR
REGION THROUGH THE HOLIDAY WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1010 PM WEDNESDAY...
ANY SHOWERS AND THUNDERSTORMS FROM THIS AFTERNOON AND EVENING
ASSOCIATED WITH THE SEA BREEZE AND OUTFLOW ACROSS THE EASTERN
TWO-THIRDS OF THE AREA HAVE DISSIPATED WITH THE LOSS OF DAYTIME
HEATING AND RESULTANT STABILIZING BOUNDARY LAYER. CONVECTION THAT
FIRED ACROSS THE HIGHER TERRAIN TODAY... HAS GENERALLY STAYED TO THE
WEST OF THE REGION WITH A 15 TO 20 KT SOUTH-SOUTHWESTERLY MEAN
STEERING FLOW. HOWEVER... A WEST-NORTHWESTERLY OUTFLOW... GENERATED
FROM THESE CLUSTERS OF SHOWERS AND STORMS THAT ORIGINATED ALONG THE
HIGHER TERRAIN... HAS FINALLY ALLOWED FOR THE DEVELOPMENT OF SHOWERS
AND STORMS ACROSS OUR FAR NORTHWESTERN REACHES OF OUR CWA... ALONG
THE OUTFLOW. THINK THIS OUTFLOW SHOULD SUPPORT AT LEAST SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ACROSS OUR WESTERN PIEDMONT
THROUGH 06/07Z... GIVEN 500 TO 1000 J/KG OF SURFACE BASED CAPE.
THEREAFTER... EXPECT BOUNDARY LAYER COOLING SHOULD YIELD A TREND TO
ISOLATED SHOWERS AT BEST. ANY SIGNIFICANT S/W ENERGY ROTATING
THROUGH THE CYCLONIC FLOW ALOFT FROM THE APPROACHING MID LEVEL
TROUGH WELL TO THE WEST OF THE AREA... INVOF THE MS RIVER THIS
EVENING... IS EXPECTED TO PASS TO THE WEST AND NORTH OF THE REGION
THUS... PLAN TO TRIM POPS TO SLIGHT CHANCE BY EARLY THURSDAY MORNING
ACROSS THE ENTIRE CWA. THIS IS SUPPORTED BY THE LATEST HRRR.
HOWEVER... ITS WORTH NOTING THE LATEST HRRR DOES SHOW SOME SHOWERS
CURRENTLY OFF THE CAROLINA COAST MOVING ONSHORE OVERNIGHT ACROSS THE
COASTAL PLAIN. CURRENT HI-RES MODELS GENERALLY SHOW THIS PRECIP
REMAINING JUST TO THE EAST OF OUR AREA. THUS... WILL KEEP ONLY
SLIGHT CHANCE POPS ACROSS OUR EAST AS WELL. OVERNIGHT LOWS IN THE
MID TO UPPER 60S ARE STILL EXPECTED... WITH GENERALLY PATCHY FOG
(FOG... AT LOCATIONS THAT ARE PICKING UP DECENT SHOWERS/STORMS
ACROSS THE TRIAD NOW) AND WIDESPREAD LOW STATUS.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 300 PM WEDNESDAY...
A COLD FRONT WILL APPROACH CENTRAL NC FROM THE WEST ON FRIDAY. AS A
DEEP 500 MB TROUGH DIGS SOUTHWARD THROUGH THE OHIO VALLEY. AS FAR AS
TIMING IS CONCERNED...SHOWERS AND THUNDERSTORMS AHEAD OF FRONT WILL
BEGIN TO AFFECT THE TRIAD BY LATE THURSDAY MORNING AND CONTINUE TO
PROGRESS SLOWLY EASTWARD ACROSS THE CWA BY AFTERNOON/EVENING. SEVERE
POTENTIAL WITH THIS SYSTEM WILL BE GREATER THAN THE PAST COUPLE OF
DAYS BUT STILL LOOKS VERY LOW. EFFECTIVE SHEAR WILL BE ABOUT 20
KNOTS SUGGESTING MORE LINEAR THUNDERSTORMS. THIS IS SUPPORTED BY THE
STRAIGHT HODOGRAPHS SHOWN BY NAM FORECAST SOUNDINGS. MID LEVEL LAPSE
RATES WILL BE WEEK ALTHOUGH 1000 ML CAPE OF THE TALL AND SKINNY
VARIETY COULD BE REALIZED BY AFTERNOON. LATER IN THE EVENT DYNAMICS
IMPROVE AS A 30 KNOT 850MB APPROACHES THE NORTHWEST. IT IS UNCLEAR
AT THIS TIME WHETHER OR NOT CONVECTION WILL BE TOO FAR TO THE EAST
TO TAKE ADVANTAGE OF THE INCREASED SHEAR. STORMS LINGERING BACK
TOWARDS THE WEST MAY BE ABLE TO TAKE ADVANTAGE OF AN INCREASED AXIS
OF DCAPE EXPECTED TO MOVE THROUGH THE CWA JUST AFTER 00Z FRIDAY.
THEREFORE IF WE DO ENCOUNTER SEVERE WEATHER TOMORROW...IT WILL MOST
LIKELY BE DAMAGING WINDS AND NOT HAIL. FOR NOW SPC HAS KEPT THE
RALEIGH AREA OUT OF THE SLIGHT RISK AREA FOR TOMORROW. PRECIPITABLE
WATERS WILL BE SIMILAR TO TODAY NEAR 1.5 INCHES BUT QPF WITH FRONTAL
PASSAGE IS ONLY EXPECTED TO BE BETWEEN A QUARTER AND A HALF OF AN
INCH WITH LOCALLY HEAVIER AMOUNTS POSSIBLE IN THUNDERSTORMS.
LOCALIZED FLOODING COULD BE AN ISSUE...ESPECIALLY IN URBAN AREAS
UNDER SLOW MOVING OR TRAINING THUNDERSTORMS. CLOUD COVER SHOULD
OVERSPREAD THE AREA FAIRLY EARLY TOMORROW AND THUS WILL TREND
TOWARDS THE COOLER MET GUIDANCE WITH HIGH TEMPERATURES. UPPER 70S IN
THE NORTHWEST TO LOW 80S SOUTHEAST. AS THE LOWER ATMOSPHERE BEGINS
TO DRY OUT LOW TEMPERATURES IN THE TRIAD SHOULD DIP INTO THE UPPER
50S IN THE NORTHWEST FOR THE FIRST TIME IN SEVERAL DAYS BUT FURTHER
TO THE SOUTHEAST LOWS WILL REMAIN IN THE MIDDLE 60S AS THE FRONT IS
EXPECTED TO FULLY MOVE THROUGH THE EAST UNTIL CLOSER TO 6Z ON FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 310 PM WEDNESDAY...
FRIDAY THROUGH SATURDAY NIGHT...
A DEEP UPPER LEVEL TROUGH WILL SWING ACROSS CENTRAL NC FRIDAY AND
EXIT THE REGION FRIDAY NIGHT. MAY SEE A FEW INSTABILITY SHOWERS
WITH THE PASSAGE OF THIS SYSTEM HOWEVER MODEL RH CROSS SECTIONS
DEPICT THE AIR MASS DRYING OUT APPRECIABLY ABOVE 5000-8000FT BY
EARLY AFTERNOON. FOR NOW WILL LIMIT POPS TO SLIGHT CHANCE. OTHERWISE
BRISK NW FLOW WILL ADVECT COOLER MORE STABLE AIR INTO THE REGION.
SUSTAINED NW WINDS 10-15 MPH WITH GUSTS AROUND 25 MPH PROBABLE. THE
ARRIVAL OF THIS AIR MASS WILL RESULT IN COOLER CONDITIONS WITH
AFTERNOON MAX TEMPS IN THE LOWER 70S NORTH TO UPPER 70S FAR SE.
FRIDAY NIGHT...SKIES WILL CLEAR EARLY THOUGH A STEADY NW SFC WIND
WILL BE SLOW TO SUBSIDE. LOW LEVEL THICKNESSES CLUSTERING AROUND
1340M. HISTORICALLY...THIS SUGGEST MIN TEMPS NEAR 40-LOWER 40S.
FAVOR THE HIGH END OF THIS REGION DUE TO EXPECTED MIXING WELL INTO
THE NIGHT. MIN TEMPS 45-50.
SATURDAY INTO SATURDAY NIGHT...CANADIAN HIGH PRESSURE OVER THE LOWER
GREAT LAKES WILL BUILD/EXTEND INTO OUR REGION SATURDAY INTO SATURDAY
NIGHT. THIS WEATHER SYSTEM WILL RESULT IN A DRY WEATHER PATTERN WITH
BELOW NORMAL TEMPS. AFTERNOON THICKNESSES PROJECTED TO BE ABOUT 35M
BELOW NORMAL...SUPPORTIVE OF TEMPS CLOSE TO 10 DEGREES BELOW NORMAL.
ALLOWING FOR WARMTH FROM LATE MAY SUN...EXPECT AFTERNOON HIGH TEMPS
IN THE MID-UPPER 70S. MOS GUIDANCE LIKELY TRENDING TOWARD
CLIMATOLOGY BY SATURDAY NIGHT. WITH SFC RIDGE OVERHEAD AND CORE OF
LOW LEVEL DRY ACROSS THE REGION...TEMPS SHOULD COOL QUICKLY INT EH
EVENING THEN STABILIZE. MODEL RH CROSS SECTIONS HINT AT INCREASING
MID-HIGH LEVEL CLOUDS OVERNIGHT INTO EARLY SUNDAY. FIRST GLANCE
SUGGEST THAT CLOUD COVERAGE MAY INITIALLY BE THIN AND SPOTTY SO
COULD SEE DECENT NOCTURNAL COOLING. FAVOR MIN TEMPS A FEW DEGREES
COOLER THAN PREVIOUS FORECAST WITH MIN TEMPS IN THE MID-UPPER 40S.
SUNDAY INTO MONDAY...DEEP UPPER LEVEL LOW OVER NORTHERN NEW
ENGLAND-CANADIAN MARITIME PROVINCES WILL MAINTAIN A NW FLOW OVER THE
FORECAST AREA SUNDAY. WEAK PERTURBATIONS IN THIS FLOW ALOFT WORKING
WITH AVAILABLE MOISTURE WILL LIKELY CAUSE AN INCREASE IN MID-HIGH
LEVEL CLOUDINESS SUNDAY INTO SUNDAY NIGHT...MORE SO ACROSS OUR WEST
AND SOUTH SECTIONS AND LEAST IN THE NE. A MODIFYING AIR MASS WILL
LEAD TO SLIGHTLY WARMER CONDITIONS WITH AFTERNOON TEMPS IN THE
MID-UPPER 70S...AND AND MIN TEMPS IN THE MID 50S. 00Z ECMWF SUGGEST
THAT THERE MAY BE ENOUGH AMPLITUDE TO AN APPROACHING MID LEVEL
TROUGH TO WARRANT A SLIGHT-SMALL CHANCE POP ACROSS CENTRAL NC MONDAY
AFTERNOON-MONDAY EVENING.
TUESDAY INTO WEDNESDAY...AN AMPLIFYING MID-UPPER LEVEL RIDGE OVER
THE EASTERN HALF OF THE U.S. WILL PLACE CENTRAL NC BACK INTO A
SUMMER-LIKE PATTERN WITH A SFC HIGH ANCHORED OFFSHORE BUT EXTENDING
WESTWARD INTO THE SE U.S. THIS SUGGEST A RETURN TO WARM AND SLIGHTLY
HUMID CONDITIONS WITH AFTERNOON TEMPS IN THE LOW-MID 80S AND MIN
TEMPS 60-65. CONVECTION APPEARS TO BE DIURNALLY DRIVEN...ADDED BY A
SEABREEZE TO SE AND NW FLOW ALOFT SENDING CONVECTION OFF THE HIGHER
TERRAIN INTO THE WESTERN PIEDMONT. POPS NO HIGHER THAN SLIGHT
CHANCE-SMALL CHANCE AT THIS TIME...CONFINED TO THE AFTERNOON-EVENING
HOURS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 205 AM THURSDAY...
A LINE OF SHOWERS AND ISOLATED STORMS THAT EARLIER AFFECTED THE
TRIAD TERMINALS WILL CONTINUE TO MOVE SLOWLY EASTWARD AT AROUND 10
MPH...AFFECTING THE KRDU AREA BETWEEN 8-10Z. A GRADUAL
WEAKENING/DISSIPATING TREND SHOULD OCCUR AS THE AIR MASS CONTINUES
TO STABILIZE WITH NOCTURNAL COOLING...HOWEVER...SO CONFIDENCE OF THE
CONVECTION REACHING THE KFAY AND KRWI AREAS IS LOW. OTHERWISE...A
CONTINUED MOIST AIR MASS WILL PROMOTE A HIGH CHANCE OF LIFR-IFR
CEILINGS THIS MORNING...THOUGH WITH RELATIVE LOWEST CHANCES - AROUND
60 PERCENT - AT TRIAD TERMINALS. THESE CEILINGS WILL LIFT AND
SCATTER TO VFR WITH HEATING THROUGH MIDDAY. HEATING OF THE MOIST AIR
MASS WILL ALSO CAUSE SCATTERED TO NUMEROUS SHOWERS AND STORMS TO
DEVELOP THIS AFTERNOON...AND THESE WILL LIKELY CONTINUE UNTIL A COLD
FRONT SWEEPS ACROSS CENTRAL NC FROM WEST TO EAST BETWEEN 04-06Z AT
TRIAD TERMINALS...TO 09-12Z AT EASTERN ONES. AREAS O FOG OR LOW
STRATUS WILL ALSO BE POSSIBLE AHEAD OF THE COLD FRONT...MOST LIKELY
AT KFAY AND KRWI BETWEEN 06-12Z.
VFR CONDITIONS WILL OTHERWISE PREVAIL IN CANADIAN HIGH PRESSURE
THROUGH THE HOLIDAY WEEKEND.
&&
.CLIMATE...
MORNING LOW TEMPERATURES ON THE 25TH AND 26TH ARE EXPECTED TO BE A
FEW DEGREES SHY OF RECORD MIN TEMPS FOR THE DATE.
RECORD MIN TEMP/YEAR SET MAY 25TH MAY 26TH
RDU 43 / 1967 43 / 1979
GSO 43 / 1956 42 / 1930
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...BSD
SHORT TERM...ELLIS
LONG TERM...WSS
AVIATION...MWS
CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
901 PM EDT FRI MAY 24 2013
.SYNOPSIS...
CHILLY HIGH PRESSURE TAKES CHARGE TONIGHT INTO SATURDAY. WARM
FRONT LIFT NORTH INTO THE OHIO VALLEY AND WEST VIRGINIA EARLY
TUESDAY. A WARMING TREND EXPECTED MEMORIAL DAY THROUGH NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
9 PM UPDATE. STILL GOING WITH A FROST SCENARIO FOR THE LOW LANDS
UNDER A FROST ADVISORY. DEWPOINTS ACROSS THE NORTH ARE NOW IN THE
LOW TO MID 30S ON A DECREASING NORTH WIND. WHILE THE MAJOR CITIES
MAY ESCAPE FROST...THE OUTLYING AREAS AND FAVORED LOW SPOTS ARE
INCREASINGLY LIKELY FOR SOME FROST. WILL MAKE NO CHANGE TO HEADLINES
NOR CURRENT FORECAST.
PREVIOUS DISCUSSION...
VERY TOUGH FCST TONIGHT REGARDING FROST/FREEZE POTENTIAL. DWPTS
CURRENTLY STRADDLING THE MARGINAL THRESHOLD FOR FROST TONIGHT
GIVEN AFTN MIXING. NOT SURE IF THESE GO LWR NEXT FEW HRS BEFORE
RECOVERING THIS EVE. GUIDANCE FOR METRO AREAS IN THE LOWLANDS RUN
32 TO 40F FROM KHTS TO KCRW. H925 WINDS STAY UP ARND 20 KTS
OVERNIGHT AS SFC HIGH BUILDS IN TO ALLOW WINDS AT THE GROUND TO
TRY TO GO CALM. ALL OF THIS COMPLICATES MATTERS FOR EXPANDING
FROST ADV. HOWEVER...GIVEN TIME OF YEAR AND FACT THAT MOST FOLKS
HAVE SOME OF THEIR VEGGIES IN THE GROUND ALONG WITH ANNUAL PLANT
INVESTMENTS...FELT PRUDENT TO LEAN A LITTLE LIBERAL AND EXPAND TO
ENCOMPASS REST OF CWA SAVE FOR S COAL FIELDS TO SW VA. OUTLYING
AREAS WILL SEE BEST SHOT OF FROST. HEADLINE SHOULD GARNER MORE
ATTENTION FOR FOLKS TO TAKE PRECAUTIONS TO BE ON SAFE SIDE. ALSO
EXPANDED FRZ WARNING TO RALEIGH BASED ON GUIDANCE RANGING FROM 28F
TO 33F. THEY WILL HAVE GET UNDER INVERSION THOUGH GIVEN H925 WINDS
OFF MDLS OVERNIGHT. OTHER CONCERN IS STRATUS OVERNIGHT ACROSS THE
N. NAM HAS BEEN WAY TOO FAST IN ERADICATING THE LLVL MOISTURE VS
RUC WHICH HAS BEEN PRETTY STEADY. RUC SHOWS CLDS LIFTING AND SCT
THIS EVE ACROSS THE N BEFORE REDEVELOPING IN N MTNS BY 06Z. NAM
KEEPS ENTIRE COLUMN DRY BUT HAS NOT HANDLED TDY WELL AT ALL. SO
WILL LEAN TOWARD RUC AND REDEVELOP SOME STRATUS IN N MTNS LATE
TONIGHT. THIS MAY KEEP TEMPS UP TONIGHT ESPECIALLY IN
VALLEYS...BUT STILL FEEL AOB FRZ TEMPS WILL BE REALIZED.
UPR TROF AXIS SHIFTS TO E COAST ON SAT WITH SOME RECOVERY IN TEMPS
COMPARED TO TDY. INHERITED TEMPS LOOKED GOOD AND ONLY NEEDED
TWEAKING SOME...MAINLY ACROSS THE N.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
MADE MODIFICATIONS TO THE SHORT TERM FORECAST AS FOLLOWS:
HIGH PRESSURE WILL BE IN CONTROL THROUGH THE WEEKEND...KEEPING DRY
CONDITIONS AREAWIDE. MODELS SHOW A MID LEVEL SHORTWAVE...EVIDENT
IN H5 CHARTS...UNDER NORTHWEST FLOW ALOFT...MOVING ACROSS SOUTHERN
OH...SOUTHEAST INTO NORTHWEST KY. REMOVED ANY POPS FOR THE WEEKEND
AS MOISTURE LOOKS VERY LIMITED OVER WV. IN FACT...THERE COULD BE
SOME CLEARING SATURDAY NIGHT INTO SUNDAY MORNING...KEEPING
TEMPERATURES AT OR JUST BELOW FREEZING OVER POCAHONTAS AND
RANDOLPH COUNTIES. INCLUDED PATCHY FROST OVER NORTHEAST MOUNTAINS.
HIGH PRESSURE MOVES EAST OVER THE MID ATLANTIC STATES KEEPING
INFLUENCE OVER WV FOR A DRY SUNDAY THROUGH MONDAY NIGHT.
MINOR CHANGES TO TEMPERATURES THROUGH THE PERIOD...PERHAPS A
COUPLE DEGREES LOWER CLOSER TO THE COOLER MET.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ANOTHER SHORTWAVE UNDER NORTHWEST FLOW ALOFT PASSES ACROSS
SOUTHEAST OH AND WV MONDAY AND TUESDAY. AT THE SAME TIME...A WARM
FRONT LIFTS NORTH INTO SOUTHERN OH...ACROSS WV AND VA ORIENTED
WEST TO EAST BY 12Z TUESDAY. THESE TWO FEATURES WILL BE CAPABLE TO
PRODUCE SHOWERS AND STORMS LATE MONDAY INTO TUESDAY AS THE WARM
FRONT MOVES NORTH OF THE AREA BY EARLY WEDNESDAY. INCREASED POPS
TO CHANCE INCLUDING THUNDER IN WEATHER GRIDS ACCORDINGLY.
HIGH PRESSURE TAKES CONTROL BY EARLY WEDNESDAY PROVIDING DRY
WEATHER WITH A SLOW WARMING TREND THROUGH THE REST OF THE WEEK.
TWEAKED COUPLE OF DEGREES DOWN FROM HPC GUIDANCE IN THE EXTENDED
PERIODS.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
EXCEPT FOR SOME NORTHERN WEST VIRGINIA HIGH ELEVATION MVFR CLOUDS
OVERNIGHT...EXPECT VFR MOSTLY CLEAR THRU THE PERIOD...AS HIGH
PRESSURE SETTLES OVER THE REGION.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY...
FORECAST CONFIDENCE...MEDIUM TO HIGH.
ALTERNATE SCENARIOS: NONE.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SAT 05/25/13
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY M M M M M M M M M M M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H M M M H H H H H
AFTER 00Z SUNDAY...
IFR CONDITIONS POSSIBLE IN FOG EARLY SATURDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR WVZ005>011-
013>020-026>032-039-040.
FREEZE WARNING FROM 2 AM TO 8 AM EDT SATURDAY FOR WVZ035>038-
046-047.
OH...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR OHZ066-067-
075-076-083>087.
KY...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR KYZ101>103-
105.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30
NEAR TERM...JMV/30
SHORT TERM...ARJ
LONG TERM...ARJ
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
748 PM EDT FRI MAY 24 2013
.SYNOPSIS...
CHILLY HIGH PRESSURE TAKES CHARGE TONIGHT INTO SATURDAY. WARM
FRONT LIFT NORTH INTO THE OHIO VALLEY AND WEST VIRGINIA EARLY
TUESDAY. A WARMING TREND EXPECTED MEMORIAL DAY THROUGH NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
VERY TOUGH FCST TONIGHT REGARDING FROST/FREEZE POTENTIAL. DWPTS
CURRENTLY STRADDLING THE MARGINAL THRESHOLD FOR FROST TONIGHT
GIVEN AFTN MIXING. NOT SURE IF THESE GO LWR NEXT FEW HRS BEFORE
RECOVERING THIS EVE. GUIDANCE FOR METRO AREAS IN THE LOWLANDS RUN
32 TO 40F FROM KHTS TO KCRW. H925 WINDS STAY UP ARND 20 KTS
OVERNIGHT AS SFC HIGH BUILDS IN TO ALLOW WINDS AT THE GROUND TO
TRY TO GO CALM. ALL OF THIS COMPLICATES MATTERS FOR EXPANDING
FROST ADV. HOWEVER...GIVEN TIME OF YEAR AND FACT THAT MOST FOLKS
HAVE SOME OF THEIR VEGGIES IN THE GROUND ALONG WITH ANNUAL PLANT
INVESTMENTS...FELT PRUDENT TO LEAN A LITTLE LIBERAL AND EXPAND TO
ENCOMPASS REST OF CWA SAVE FOR S COAL FIELDS TO SW VA. OUTLYING
AREAS WILL SEE BEST SHOT OF FROST. HEADLINE SHOULD GARNER MORE
ATTENTION FOR FOLKS TO TAKE PRECAUTIONS TO BE ON SAFE SIDE. ALSO
EXPANDED FRZ WARNING TO RALEIGH BASED ON GUIDANCE RANGING FROM 28F
TO 33F. THEY WILL HAVE GET UNDER INVERSION THOUGH GIVEN H925 WINDS
OFF MDLS OVERNIGHT. OTHER CONCERN IS STRATUS OVERNIGHT ACROSS THE
N. NAM HAS BEEN WAY TOO FAST IN ERADICATING THE LLVL MOISTURE VS
RUC WHICH HAS BEEN PRETTY STEADY. RUC SHOWS CLDS LIFTING AND SCT
THIS EVE ACROSS THE N BEFORE REDEVELOPING IN N MTNS BY 06Z. NAM
KEEPS ENTIRE COLUMN DRY BUT HAS NOT HANDLED TDY WELL AT ALL. SO
WILL LEAN TOWARD RUC AND REDEVELOP SOME STRATUS IN N MTNS LATE
TONIGHT. THIS MAY KEEP TEMPS UP TONIGHT ESPECIALLY IN
VALLEYS...BUT STILL FEEL AOB FRZ TEMPS WILL BE REALIZED.
UPR TROF AXIS SHIFTS TO E COAST ON SAT WITH SOME RECOVERY IN TEMPS
COMPARED TO TDY. INHERITED TEMPS LOOKED GOOD AND ONLY NEEDED
TWEAKING SOME...MAINLY ACROSS THE N.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
MADE MODIFICATIONS TO THE SHORT TERM FORECAST AS FOLLOWS:
HIGH PRESSURE WILL BE IN CONTROL THROUGH THE WEEKEND...KEEPING DRY
CONDITIONS AREAWIDE. MODELS SHOW A MID LEVEL SHORTWAVE...EVIDENT
IN H5 CHARTS...UNDER NORTHWEST FLOW ALOFT...MOVING ACROSS SOUTHERN
OH...SOUTHEAST INTO NORTHWEST KY. REMOVED ANY POPS FOR THE WEEKEND
AS MOISTURE LOOKS VERY LIMITED OVER WV. IN FACT...THERE COULD BE
SOME CLEARING SATURDAY NIGHT INTO SUNDAY MORNING...KEEPING
TEMPERATURES AT OR JUST BELOW FREEZING OVER POCAHONTAS AND
RANDOLPH COUNTIES. INCLUDED PATCHY FROST OVER NORTHEAST MOUNTAINS.
HIGH PRESSURE MOVES EAST OVER THE MID ATLANTIC STATES KEEPING
INFLUENCE OVER WV FOR A DRY SUNDAY THROUGH MONDAY NIGHT.
MINOR CHANGES TO TEMPERATURES THROUGH THE PERIOD...PERHAPS A
COUPLE DEGREES LOWER CLOSER TO THE COOLER MET.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ANOTHER SHORTWAVE UNDER NORTHWEST FLOW ALOFT PASSES ACROSS
SOUTHEAST OH AND WV MONDAY AND TUESDAY. AT THE SAME TIME...A WARM
FRONT LIFTS NORTH INTO SOUTHERN OH...ACROSS WV AND VA ORIENTED
WEST TO EAST BY 12Z TUESDAY. THESE TWO FEATURES WILL BE CAPABLE TO
PRODUCE SHOWERS AND STORMS LATE MONDAY INTO TUESDAY AS THE WARM
FRONT MOVES NORTH OF THE AREA BY EARLY WEDNESDAY. INCREASED POPS
TO CHANCE INCLUDING THUNDER IN WEATHER GRIDS ACCORDINGLY.
HIGH PRESSURE TAKES CONTROL BY EARLY WEDNESDAY PROVIDING DRY
WEATHER WITH A SLOW WARMING TREND THROUGH THE REST OF THE WEEK.
TWEAKED COUPLE OF DEGREES DOWN FROM HPC GUIDANCE IN THE EXTENDED
PERIODS.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
EXCEPT FOR SOME NORTHERN WEST VIRGINIA HIGH ELEVATION MVFR CLOUDS
OVERNIGHT...EXPECT VFR MOSTLY CLEAR THRU THE PERIOD...AS HIGH
PRESSURE SETTLES OVER THE REGION.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY...
FORECAST CONFIDENCE...MEDIUM TO HIGH.
ALTERNATE SCENARIOS: NONE.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SAT 05/25/13
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY M M M M M M M M M M M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H M M M H H H H H
AFTER 00Z SUNDAY...
IFR CONDITIONS POSSIBLE IN FOG EARLY SATURDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR WVZ005>011-
013>020-026>032-039-040.
FREEZE WARNING FROM 2 AM TO 8 AM EDT SATURDAY FOR WVZ035>038-
046-047.
OH...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR OHZ066-067-
075-076-083>087.
KY...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR KYZ101>103-
105.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30
NEAR TERM...30
SHORT TERM...ARJ
LONG TERM...ARJ
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
718 PM EDT FRI MAY 24 2013
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE CENTERED OVER THE WESTERN GREAT LAKES
WILL MOVE LITTLE THROUGH THE WEEKEND...THEN SLIDE TO THE EAST COAST
MONDAY AND TUESDAY. A WARM FRONT WILL DEVELOP OVER THE MISSISSIPPI
VALLEY BY MONDAY AND LIFT NORTH ACROSS THE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
MADE MINOR ADJUSTMENTS TO THE HOURLY TEMPERATURES AND SKY COVER THIS
EVENING FOR THE EARLY EVENING UPDATE. CALLED IT "CLEARING" FOR THE
NE OH/NW PA COUNTIES...OTHERWISE NO CHANGES TO THE CURRENT FORECAST.
EARLIER DISCUSSION...
GIVEN THE TIME OF YEAR AND IMPACT AND HAVE GONE WITH FROST AND
FREEZE HEADLINES FOR THE ENTIRE AREA. IT APPEARS THAT CLEARING
WILL RAPIDLY OCCUR THIS EVENING. WINDS SHOULD ALSO LESSEN. IF
SPEEDS STAY MORE THAN 5 OR 6 MPH OVERNIGHT FREEZING TEMPS WILL BE
HARD TO ACHIEVE. IF FREEZING TEMPS DO OCCUR IT WILL BE ONE OF THE
LATEST FREEZES EVER AT ALL OF THE CLIMATE SITES. TEMPS REMAIN IN
THE 40S MOST AREAS AND SHOULD DROP QUICKLY AFTER SUNSET. SOME
INDICATION THAT HIGH CLOUDS COULD SPILL INTO WESTERN AREAS LATE
TONIGHT. GIVEN THE STRENGTH OF THE HIGH THIS COULD BE A LITTLE
OVERDONE SO HAVE TAKEN THE FROST HEADLINE ALL THE WAY TO KTOL AND
KFDY. LATEST HRRR HAS SURFACE TEMPS TO 34 DEGREES BY 04Z OVER MOST
OF INLAND NE OH AND NW PA. IF THAT OCCURS FROST IS LIKELY BY EARLY
MORNING.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
DRY HIGH PRESSURE WILL DOMINATE THROUGH THE HOLIDAY WEEKEND. THE
AREA WILL REMAIN COOL WITH ONLY VERY SLOWLY MODERATING TEMPERATURES.
WILL LIKELY NEED MORE FROST HEADLINES SATURDAY NIGHT IN THE EAST.
EXPECT TEMPS TO STRUGGLE TO GET ABOVE 60 ON SATURDAY AND OUT OF
THE LOWER AND MIDDLE 60S ON SUNDAY. TEMPERATURE MAY GET TO 70 ON
MONDAY BUT THAT WILL STILL BELOW NORMAL. MODELS HAVE BEEN SHOWING
A SYSTEM MOVING OUT OF THE PLAINS MONDAY. A WARM FRONT FROM THIS
SYSTEM WILL BEGIN TO IMPACT THE AREA MONDAY NIGHT AND HAVE PUT
SOME WARM AIR ADVECTION PRECIP IN THE WEST MONDAY NIGHT. THINK DRY
WEATHER WILL PREVAIL IN THE EAST TILL AFTER THE SHORT TERM PERIOD.
GIVEN A LOOK AT UPSTREAM SATELLITE TODAY SKIES SHOULD BE ALMOST
COMPLETELY CLEAR ON SATURDAY WITH JUST SOME HIGH CLOUDS THE
REMAINDER OF THE WEEKEND. HAVE TRENDED TO COOL SIDE OF GUIDANCE
THROUGH THE PERIOD.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE TUESDAY AND
TUESDAY NIGHT AS A WARM FRONT LIFTS THROUGH. IN THE WARM AIR MASS
WEDNESDAY THROUGH FRIDAY THERE COULD BE SOME POP UP SHOWERS AND
THUNDERSTORMS...CONTINUING THE 20 POPS. OTHERWISE A WARMING TREND
WITH HIGHS ABOVE NORMAL. USED A BLEND OF GUIDANCE...ESPECIALLY HPC.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDING EAST AT THIS TIME WITH CLEAR SKIES WEST
HALF AND CLEARING SKIES EXPECTED IN THE EAST HALF. CLOUDS ARE
DIURNAL IN NATURE AND SHOULD DISSIPATE AFTER SUNSET. WINDS MAY
TAKE A LITTLE WHILE TO DIMINISH TO LIGHT AND VARIABLE OVERNIGHT.
EXPECTING AN INCREASE IN WINDS TO 10 KNOTS FROM CLEVELAND TO
MANSFIELD WEST AND TO 15 KNOTS POSSIBLE EAST OF THAT LINE
DURING THE DAY. MAINLY CIRRUS EXPECTED TO MOVE EAST OVER THE AREA
LATE TONIGHT INTO TOMORROW. OTHERWISE...VFR.
.OUTLOOK...NON VFR POSSIBLE IN SHOWERS AND THUNDERSTORMS MONDAY
NIGHT THROUGH TUESDAY.
&&
.MARINE...
DROPPING THE SMALL CRAFT ADVISORY ON THE EXTREME WEST END OF THE
LAKE AS THE HIGH IS BUILDING IN. OTHERWISE NO CHANGES TO THE
HEADLINES. THE ONLY CONCERN IS THAT THE WAVES COULD BE NEAR SMALL
CRAFT ADVISORY CRITERIA SATURDAY AFTERNOON IN THE NORTHWEST
FLOW...THIS WILL HAVE TO BE MONITORED.
OTHERWISE NOT EXPECTING CONDITIONS TO MEET SMALL CRAFT ADVISORY
CONDITIONS ON THE LAKE IN A MAINLY SOUTHWEST FLOW.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EDT SATURDAY FOR
OHZ003-006>012-017>019-027-028-036-089.
FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT SATURDAY FOR
OHZ013-014-020>023-029>033-037-038-047.
PA...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EDT SATURDAY FOR
PAZ001.
FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT SATURDAY FOR
PAZ002-003.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR LEZ146>149.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LEZ144-145.
&&
$$
SYNOPSIS...KOSARIK/KUBINA
NEAR TERM...KOSARIK/KUBINA
SHORT TERM...KUBINA
LONG TERM...KIELTYKA
AVIATION...LOMBARDY
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
121 AM EDT THU MAY 23 2013
.SYNOPSIS...
AN APPROACHING UPPER LEVEL TROUGH WILL CONTINUE TO INFLUENCE THE
REGION THROUGH THURSDAY. A COLD FRONT MOVES THROUGH THE AREA
THURSDAY NIGHT...BEFORE A COOLER AND DRIER AIRMASS SETTLES IN FOR
THE WEEKEND AND MODIFIES THROUGH THE EARLY PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
0500 UTC UPDATE...POPS WERE REALIGNED TO CONCUR WITH RADAR
TRENDS...MOVING A LINE OF CONVECTION ACROSS INTERSTATE 77 OVER THE
NET FEW HOURS...ANOTHER CLUSTER OF STORMS ACROSS THE UPPER SAVANNAH
RIVER VALLEY...AND A THIRD GROUP OF STORMS FROM THE GA MOUNTAINS
INTO SC. WINDS WERE UPDATED WITH A BLEND OF THE LATEST ADJMAV AND
NAM...FAVORING THE LATER FOR HIGHER WINDS IN THE MOUNTAINS.
VISIBILITY WAS UPDATED FORM OBSERVATIONS AND A BLEND OF THE ADJMAV
AND ADJMET...LOWERED SLIGHTLY TOWARD THE LAMP GUIDANCE.
AS OF 1045 PM...BROKEN MULTICELL LINE OF THUNDERSTORMS CONTINUES TO
MOVE TO THE EAST NORTHEAST ACROSS THE UPSTATE IN ASSOCIATION WITH
CONVERGENCE NEAR FRONTAL BOUNDARY. ELSEWHERE...DISCRETE PULSE
SHOWERS AND THUNDERSTORMS WERE PRESENT ACROSS PORTIONS OF THE NORTH
CAROLINA FOOTHILLS/PIEDMONT. THE MAIN THREATS WITH ANY OF THESE
THUNDERSTORMS ARE BRIEF HEAVY RAINFALL...LARGE HAIL...DAMAGING
WINDS...AND FREQUENT CLOUD TO GROUND LIGHTNING. AS FOR THE
FCST...THE ACTIVITY CURRENTLY EXTENDING ACROSS THE WESTERN CWFA
SHOULD MOVE EASTWARD ACROSS THE CWFA GRADUALLY DIMINISHING IN
INTENSITY AS INSTABILITY WANES. GENERALLY CHANGED POPS TO REFLECT
THIS WAVE OF ACTIVITY BEING FOLLOWED BY MUCH LOWER POPS IN SCHC TO
LOW CHC RANGE DUE TO CONTINUED PRESENCE OF UPSTREAM ACTIVITY.
ADJUSTED TEMPERATURE TRENDS FURTHER BY LOWERING TEMPS ACROSS THE
NORTH CAROLINA PIEDMONT DUE TO OUTFLOW BOUNDARIES FROM EARLIER
CONVECTION SPREADING ACROSS THIS REGION.
REMAINDER OF PREVIOUS DISCUSSION...
AS OF 800 PM...TOUCHED UP EVENING TEMP TRENDS...WHICH HAVE BEEN
IMPACTED GREATLY BY THUNDERSTORMS AND THEIR COOL OUTFLOW. RADAR
INDICATES SEVERAL BOUNDARIES SPREADING ACROSS THE PIEDMONT...WHERE
TEMPS REMAIN IN THE MID TO UPPER 70S. THINK THESE WILL BE IMPACTED
BY BOTH DIURNAL COOLING AS WELL AS THE OUTFLOW. LAMP TEMPS SEEM TO
REFLECT THE CURRENT SITUATION FAIRLY WELL AND THESE ARE IN DECENT
AGREEMENT WITH LATE EVENING TEMPS...SO NO CHANGES MADE OTHER THAN TO
UPDATE FIRST FEW HRS.
AS OF MID AFTERNOON...A BROKEN BAND OF SHOWERS AND THUNDERSTORMS WAS
LOCATED JUST EAST OF THE BLUE RIDGE IN NC FROM I-40 NEWD...WITH
OTHER STORMS POPPING UP ACROSS THE HIGHER TERRAIN AIDED BY
DIFFERENTIAL HEATING. EXPECT THE STORMS TO BECOME MORE NUMEROUS
ACROSS THE MTNS THROUGH LATE AFTERNOON...WITH THAT CONVECTION MOVING
EAST OVER THE FOOTHILLS AND PIEDMONT INTO THE EVENING. POP HAS BEEN
ADJUSTED ACCORDINGLY. SOME OF THESE STORMS WILL PRODUCE LARGE HAIL
AND DAMAGING WIND GUSTS. HIGH TEMPS STILL LOOK OKAY.
FOR TONIGHT...THE CONVECTION ALLOWING MODELS SUGGEST THAT ANOTHER
ROUND OF STORMS WILL FIRE TO THE WEST AND THEN MOVE EAST INTO THE
FCST AREA IN THE EARLY EVENING. THE HRRR AND 4KM WRF PAINT A SIMILAR
PICTURE WITH NUMEROUS STORMS OVER THE WESTERN HALF OF THE FCST AREA
THROUGH MID TO LATE EVENING. A SHORT WAVE MOVING AROUND THE UPPER
TROF...COMBINED WITH SOME UPPER DIVERGENCE...SHOULD PROVIDE THE
NECESSARY SUPPORT FOR THIS CONVECTION TO THRIVE. WITH THAT IN
MIND...THE POP WAS RAISED TO LIKELY OVER THE WESTERN HALF. AFTER
SOME LOSS OF HEATING...THE STORMS SHOULD BECOME A BIT LESS NUMEROUS
OVER THE NC PIEDMONT. AT THAT POINT...THE POP WAS KEPT BELOW 50 PCT
ONLY BECAUSE OF SOME UNCERTAINTY GIVEN BY THE CONVECTION HAVING NOT
YET DEVELOPED AS OF 18Z. MIN TEMPS SHOULD REMAIN MILD.
THE COLD FRONT WILL MOVE IN FROM THE WEST ON THURSDAY...MOST LIKELY
OVER THE MTNS IN THE MORNING AND THEN MOVING OUT OVER THE FOOTHILLS
IN THE AFTERNOON. NEW CONVECTION SHOULD DEVELOP ALONG THE FRONT
MAINLY OVER THE PIEDMONT IN THE AFTERNOON. THIS IS TRICKY BECAUSE OF
THE LIKELIHOOD OF WIDESPREAD DEBRIS CLOUDINESS INTO THE EARLY
AFTERNOON THAT WOULD LIMIT CONVECTION. THINK THE MTNS STAND A CHANCE
BECAUSE OF THE FRONT EARLY IN THE DAY. THE UPSTATE AND NE GEORGIA
HAS THE LEAST FAVORABLE ENVIRONMENT...SO A 20 PCT POP WAS KEPT. THE
PIEDMONT HAS A BETTER CHANCE AHEAD OF THE FRONT SO A LIKELY POP WAS
CARRIED OVER THE EASTERN ZONES FOR A TIME. SEVERE STORMS ARE
POSSIBLE...BUT MORE LIKELY TO THE EAST OF I-77. HIGH TEMPS WILL BE
A FEW DEGREES COOLER.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AS OF 230 PM WEDNESDAY...A SURFACE COLD FRONT SHOULD BE LOCATED NEAR
THE EDGE OF OUR WESTERN NORTH CAROLINA PIEDMONT EARLY THURSDAY
EVENING. THIS LINES UP WELL WITH THE SHORT TERM SUITE OF MODELS...
AND LINES UP WITH WITH AN AXIS OF DPVA WHICH SHOULD BE CROSSING THAT
REGION LATE IN THE DAY/EARLY EVENING. CONVECTIVE ALLOWING MODELS
ALSO DEPICT THIS TREND AND IS SUPPORTED BY INSTABILITY LINGERING
ACROSS THAT AREA. AS A RESULT WE WILL HAVE A CORRIDOR OF LOWER
CHANCE POPS IN OUR EASTERN FORECAST AREA (FA) UNTIL AROUND DARK OR
SO.
A SECOND AREA OF PRECIPITATION FOR THURSDAY NIGHT WILL BE IN THE NC
MOUNTAINS WHERE ANOTHER LOBE OF ENERGY...EMBEDDED IN A SHARPENING H5
TROF...CROSSES THE AREA. WE WILL CARRY CHANCE POPS IN THE NC
MOUNTAINS THURSDAY NIGHT AND FRIDAY MORNING...IN A CONTINUALLY
DEEPENING FORCED UPPER AIR PATTERN. ALTHOUGH THE SHARPENING TROF
CROSSES ALL OF OUR REGION FRIDAY...THE ATMOSPHERE LOOKS TO DRY FOR
ANY PRECIPITATION.
MEANWHILE THE H85 ISALLOBARIC PATTERN WAS INDICATING SIGNIFICANT
CROSS CONTOURS OF THERMAL STRUCTURE AND HEIGHTS FRIDAY. THIS
SUGGESTS AT LEAST SIGNIFICANT COLD AIR ADVECTION (ESPECIALLY JUST
ABOVE THE SURFACE) AND MIXING DOWN. WE HAVE FOLLOWED BUFKIT
INFORMATION FOR WIND GUSTS FRIDAY...AND IN ALL LIKELIHOOD WE WILL
NEED SOME TYPE OF WIND HEADLINE FRIDAY FOR PART OF OUR FAA...
PARTICULARLY IN THE AFTERNOON.
HIGH PRESSURE WILL EDGE TOWARD THE REGION FRIDAY NIGHT...WHICH WILL
BRING A COOL/COLD NIGHT AROUND THE AREA. SOME MOUNTAIN LOCATIONS TO
DIP INTO THE 30S...BUT BELIEVE ENOUGH MIXING SHOULD PREVENT FROST
DUE TO THE LINGERING GRADIENT OF HIGH PRESSURE OFF TO THE NORTHWEST
AND LOW PRESSURE MOVING UP THE EASTERN SEABOARD. HOWEVER WE WILL
HAVE TO MONITOR TRENDS.
HIGH PRESSURE TO HOLD SWAY SATURDAY WITH A PLEASANT DAY ON
TAP.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 225 PM WEDNESDAY...RATHER GOOD AGREEMENT IS HAD IN THE UPPER
LEVEL OMEGA PATTERN OVER THE EXT RANGE. THE 12Z GFS IS A BIT OF AN
OUTLIER AND SHARPENS THE EAST COAST TROF AND SUBSEQUENT DEEP NW/LY
FLOW GRADIENT MORESO THAN THE OTHER OP MODELS...BUT NOT ENOUGH FOR A
SIGFNT LLVL RESPONSE. AT THE SFC...THERE ARE MAJOR DIFFERENCES
EVOLVING WITH THE SYNOPTIC PATTERN...THUS A LESS THAN AVG
CONFIDENCE IS HAD AS THE EXT RANGE PROGRESSES.
HIGH PRESSURE CONTINUES TO BUILD IN FROM THE NORTH SUN AND KEEPS
THINGS DRY. HIGH TEMPS WILL BE A LITTLE BELOW NORMAL WITH A
REINFORCING CP AIRMASS MIXING IN. THE LLVL FLOW BECOMES DEFINED
SW/LY MON AS THE ATL HIGH NUDGES IN. THIS WILL ALSO ENABLE A WARM
FRONT OR STATIONARY TO PERHAPS IMPINGE UPON THE REGION MON NIGHT
INTO TUE. THERE IS LOW CONFIDENCE IN THIS FEATURE...HOWEVER...AS THE
GFS KEEPS ANY FRONTOGENESIS WELL TO THE NORTH OF THE REGION WITH A
WEAK TROF BUILDING INTO THE SFC SE RIDGE...WHILE THE ECMWF HAS THE
WARM FRONT STALLING OUT ACROSS THE CWFA DURING THE DAY TUE INTO WED.
RIGHT NOW...POPS HAVE BEEN CONTINUED IN THE LOW END CHANCE RANGE MON
THROUGH TUE...AND A DRIER HPC BLEND WAS MAINTAINED FOR WED.
SOUNDINGS SHOW VERY LITTLE SBCAPE DEVELOPING MON AS THE UPPER FLOW
KEEPS A SUBSIDENCE INVERSION IN PLACE...HOWEVER A RELATIVE WEAKENING
ALOFT TUE SHOULD ENABLE THE DEVELOPMENT OF SOME ENHANCE CONVECTION
AND TSTMS. MAX TEMPS WILL WARM EACH DAY MON THROUGH THE PERIOD TO A
LITTLE ABOVE NORMAL IN GOOD SW/LY FLOW AND INSOLATION.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AT KCLT...ANOTHER LINE OF THUNDERSTORMS WILL CROSS THE FIELD
SHORTLY...THEN ACTIVITY WILL DIMINISH. A DAMP AIR MASS AND PRIOR
RAINFALL AMOUNTS SUPPORT VSBY AND CIG RESTRICTIONS TOWARD DAWN...AND
MVFR WILL BE CARRIED. SW WINDS WILL MIX OUT RESTRICTIONS AFTER IN
THE MORNING. ANOTHER ROUND OF CONVECTION WITH POSSIBLE RESTRICTIONS
IS EXPECTED ON THURSDAY AS A COLD FRONT MOVES THROUGH FROM THE
W...AND ANOTHER APPROACHES FROM THE NW. CONVECTION WILL MOVE OFF TO
THE EAST BY THURSDAY EVENING....WHILE SW WINDS VEER TO NW AND BECOME
GUSTY.
ELSEWHERE...CONVECTION WILL MOVE EAST OUR OF THE FOOTHILLS SHORTLY.
EARLIER RAINFALL HAS MOISTENED THE ATMOSPHERE AND GROUND TO THE
POINT THAT AT LEAST MVFR RESTRICTIONS ARE EXPECTED BY DAYBREAK...AND
TEMPORARY IFR AT KAVL. BY MID MORNING RESTRICTIONS WILL END AS THE
WINDS COMES UP FROM THE SW IN THE FOOTHILLS ND NW IN THE MOUNTAINS.
ADDITIONAL CONVECTION AND RESTRICTIONS ARE EXPECTED BY MIDDAY
BETWEEN A DEPARTING COLD FRONT...AND ANOTHER STRONGER FRONT ARRIVING
FROM THE NW. WINDS WILL VEER TO THE WEST DURING THE DAY IN THE
FOOTHILLS AND BECOME GUSTY...VEERING FURTHER TO BECOME NW IN THE
EVENING. PRECIPITATION WILL BE MAINLY CONFINED TO THE MOUNTAINS
THURSDAY EVENING IN NW UPSLOPE FLOW.
OUTLOOK...RESTRICTIONS POSSIBLE WITH LINGERING MOISTURE OVERNIGHT
THU NIGHT AND FRI MORNING. GENERALLY VFR WEATHER FRIDAY AND SATURDAY.
CONFIDENCE TABLE...
05-11Z 11-17Z 17-23Z 23-05Z
KCLT HIGH 84% HIGH 90% HIGH 100% HIGH 100%
KGSP MED 79% HIGH 88% HIGH 100% HIGH 100%
KAVL MED 70% HIGH 88% HIGH 100% HIGH 97%
KHKY LOW 56% HIGH 83% HIGH 100% HIGH 100%
KGMU MED 73% HIGH 83% HIGH 100% HIGH 100%
KAND MED 69% HIGH 94% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...SBK
NEAR TERM...CDG/JAT/PM/WIMBERLEY
SHORT TERM...TS
LONG TERM...SBK
AVIATION...JAT
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1107 PM CDT FRI MAY 24 2013
.UPDATE...
ISSUED AT 930 PM CDT FRI MAY 24 2013
LATE AFTERNOON CONVECTION ROUND HAS MOVED EAST OF THE AREA WHILE
LEAVING VERY SPOTTY LIGHT SHOWERS FAR EAST. NEXT ROUND THE
DEVELOPED OVER WESTERN AND CENTRAL NE HAS BEEN TURNING MORE EAST
NORTHEAST WITH THE STRONGER CONVECTION AND EXPECT THIS TREND TO
CONTINUE. HOWEVER...FEEL THE SHORT TERM RAP CONTINUES TO BE MORE
IN TUNE WITH THE THREAT OF LIGHT TO MODERATE CONVECTION DEVELOPING
NORTH OF THIS AREA AND AFFECTING ESPECIALLY THE SOUTHERN EDGE OF
THE FORECAST AREA...MORE FAR SOUTHEAST VERY LATE TONIGHT. THE NAM
CONTINUES TO DOWNPLAY THIS THREAT. OVERALL LOW TEMPERATURES LOOK
OK WITH HOURLY READING EXPECTED TO GRADUALLY EVEN OUT...THAT IS
THE TEMPERATURES CONTRAST FROM SOUTH TO NORTH SHOULD DECREASE A
LITTLE.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 332 PM CDT FRI MAY 24 2013
SCATTERED SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE CWA WITH
THE MOST CONCENTRATED AREA NORTH OF INTERSTATE 90 AND EAST OF
INTERSTATE 29 THIS EVENING. WITH THE WAVE THAT IS AIDING IN THIS
DEVELOPMENT MOVING NORTHEAST SUSPECT THE TREND TO THE EAST AND
NORTH WITH THIS ACTIVITY WILL CONTINUE. SHEAR AND INSTABILITY NOT
ENOUGH FOR SEVERE THUNDERSTORMS BUT SOME VERY SMALL HAIL POSSIBLE
WITH THE STRONGER STORMS. BETWEEN ABOUT 3Z TO 6Z THE LOW LEVEL JET
INCREASES QUITE A BIT IN CENTRAL NEBRASKA AND BEGINS TO FOCUS THE
BEST CONVERGENCE/ADVECTION TOWARDS THE MISSOURI RIVER ALONG THE
SOUTH DAKOTA NEBRASKA BORDER. THE WEAKEST CIN AND HIGHEST CAPE
VALUES SUGGEST THAT A PARCEL LIFTED FROM ABOUT 850MB TO 800MB WOULD
HAVE ABOUT 1500 J/KG TO WORK WITH. WHILE THE EFFECTIVE SHEAR IS
QUITE WEAK SOME NICKEL TO DIME SIZED HAIL WOULD BE POSSIBLE NEAR THE
MISSOURI RIVER. WITH FAIRLY SLOW STORM MOTION ANY STORMS THAT COULD
DEVELOP WOULD HAVE THE POTENTIAL TO PRODUCE SOME HEAVIER RAINFALL.
WILL KEEP THE HIGHEST POPS ALONG THE MISSOURI RIVER INTO NORTHWEST
IOWA OVERNIGHT WITH A TREND DOWNWARD IN RAIN AND THUNDERSTORM
POTENTIAL ON SATURDAY. OTHER THAN CONVECTIVE BLOW OFF OR SOMETHING
THAT ADVECTS IN IT LOOKS LIKE CAPPING WILL KEEP THUNDERSTORMS AT BAY
MOST OF THE DAY IN MOST LOCATIONS. STILL EXPECTING QUITE A BIT OF
CLOUD COVER AND COOL TEMPERATURES...RANGING FROM THE MID 60S EAST OF
THE BUFFALO RIDGE TO 75 TO 80 IN SOUTH CENTRAL SOUTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 332 PM CDT FRI MAY 24 2013
MODELS SUGGEST THAT A PAIR OF WAVES MAY BEGIN NOSING INTO BLACK
HILLS AREA SATURDAY AFTERNOON AND AGAIN SUNDAY AFTERNOON...
TRIGGERING CONVECTION TO OUR WEST SATURDAY EVENING AND SOUTHWEST ON
SUNDAY EVENING. WITH A QUASI-STATIONARY BOUNDARY DRAPED ACROSS THE
REGION...VERY HIGH PRECIPITABLE WATER AMOUNTS THROUGHOUT THE REGION
AND A STRENGTHENING LOW LEVEL JET NEAR THE MISSOURI RIVER BOTH
NIGHTS...EXPECT SHOWER AND THUNDERSTORM POTENTIAL TO PEAK DURING THE
EVENING AND OVERNIGHT HOURS. MAIN CONCERN WITH THIS CONVECTION WOULD BE
LOCALLY HEAVY RAINFALL AMOUNTS AND STRONG WIND GUSTS. MARGINALLY
SEVERE HAIL WILL ALSO BE POSSIBLE...HOWEVER THIS THREAT WOULD BE
MAINLY DURING THE EVENING HOURS. PRECIPITATION CHANCES DO DIMINISH
SLIGHTLY DURING THE DAY ON SUNDAY...BUT WILL KEEP SCATTERED MENTION
GOING THROUGH THE DAY WITH SOME TIMING UNCERTAINTY.
VERY ACTIVE AND WET PATTERN IS EXPECTED TO PERSIST THROUGH THE
ENTIRE MID AND LONG RANGE WITH PRECIPITATION IN THE FORECAST EACH
PERIOD...INCLUDING MEMORIAL DAY. STILL SEEING QUITE A BIT OF
UNCERTAINTY WITH TIMING ALL OF THE SHORTWAVES TRACKING THROUGH THE
REGION ALONG THE GENERAL UPPER LEVEL SOUTHWEST FLOW. WEST COAST
TROUGHING STARTS NUDGING FURTHER EAST INTO THE HIGH PLAINS LATE WEEK
NEXT WEEK...HOWEVER THE SLOW MOVING NATURE OF THIS SYSTEM KEEPS
IT...AND PRECIPITATION IN THE FORECAST EVEN THROUGH NEXT WEEKEND.
TEMPERATURES WILL WARM A LITTLE TO SLIGHTLY ABOVE NORMAL READINGS
AROUND MID WEEK BUT WILL START TO COOL A BIT LATE WEEK WITH POTENTIAL
TROUGHING ARRIVING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1103 PM CDT FRI MAY 24 2013
MODELS CONTINUE TO SHOW CEILINGS DETERIORATING INTO MVFR-IFR RANGE
LATER TONIGHT AT ALL TAF SITES. STARTING TO SEE HINTS OF MVFR CLOUDS
IN EASTERN NEBRASKA AS OF 04Z...SO WILL CONTINUE THIS DOWNWARD TREND
IN CEILINGS THROUGH THE FIRST 4-6 HOURS OF TAF PERIOD...WITH NEXT
CHANCE OF RAIN EXPANDING INTO SOUTHERN PARTS OF THE AREA ALONG WITH
THE LOWER CEILINGS. SOME MID LEVEL INSTABILITY PRESENT AS THE RAIN
MOVES INTO SOUTHWEST PARTS OF THE FORECAST AREA...BUT PRECIP MOVES
INTO MORE STABLE AIRMASS AS IT PROGRESSES EASTWARD...LEADING TO MORE
ISOLATED THUNDER THREAT ALONG AND EAST OF I-29 CORRIDOR. THUS HAVE
LEFT MENTION OF THUNDER OUT OF KFSD/KSUX TAFS AT THIS TIME...THOUGH
CANNOT COMPLETELY BE RULED OUT 08Z-15Z...ESPECIALLY AT KSUX. BULK OF
MVFR CEILINGS EXPECTED TO BECOME MORE SCATTERED THROUGH THE LATE
MORNING/EARLY AFTERNOON SATURDAY...THOUGH WITH MORE ABUNDANT LOW
LEVEL MOISTURE...POTENTIAL FOR MVFR CUMULUS AT TIMES THROUGH THE
AFTERNOON. GREATER CHANCE OF MVFR-IFR REDEVELOPMENT SATURDAY EVENING
WITH NEXT CHANCE OF CONVECTION SPREADING INTO THE AREA.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...08
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
930 PM CDT FRI MAY 24 2013
.UPDATE...
ISSUED AT 930 PM CDT FRI MAY 24 2013
LATE AFTERNOON CONVECTION ROUND HAS MOVED EAST OF THE AREA WHILE
LEAVING VERY SPOTTY LIGHT SHOWERS FAR EAST. NEXT ROUND THE
DEVELOPED OVER WESTERN AND CENTRAL NE HAS BEEN TURNING MORE EAST
NORTHEAST WITH THE STRONGER CONVECTION AND EXPECT THIS TREND TO
CONTINUE. HOWEVER...FEEL THE SHORT TERM RAP CONTINUES TO BE MORE
IN TUNE WITH THE THREAT OF LIGHT TO MODERATE CONVECTION DEVELOPING
NORTH OF THIS AREA AND AFFECTING ESPECIALLY THE SOUTHERN EDGE OF
THE FORECAST AREA...MORE FAR SOUTHEAST VERY LATE TONIGHT. THE NAM
CONTINUES TO DOWNPLAY THIS THREAT. OVERALL LOW TEMPERATURES LOOK
OK WITH HOURLY READING EXPECTED TO GRADUALLY EVEN OUT...THAT IS
THE TEMPERATURES CONTRAST FROM SOUTH TO NORTH SHOULD DECREASE A
LITTLE.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 332 PM CDT FRI MAY 24 2013
SCATTERED SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE CWA WITH
THE MOST CONCENTRATED AREA NORTH OF INTERSTATE 90 AND EAST OF
INTERSTATE 29 THIS EVENING. WITH THE WAVE THAT IS AIDING IN THIS
DEVELOPMENT MOVING NORTHEAST SUSPECT THE TREND TO THE EAST AND
NORTH WITH THIS ACTIVITY WILL CONTINUE. SHEAR AND INSTABILITY NOT
ENOUGH FOR SEVERE THUNDERSTORMS BUT SOME VERY SMALL HAIL POSSIBLE
WITH THE STRONGER STORMS. BETWEEN ABOUT 3Z TO 6Z THE LOW LEVEL JET
INCREASES QUITE A BIT IN CENTRAL NEBRASKA AND BEGINS TO FOCUS THE
BEST CONVERGENCE/ADVECTION TOWARDS THE MISSOURI RIVER ALONG THE
SOUTH DAKOTA NEBRASKA BORDER. THE WEAKEST CIN AND HIGHEST CAPE
VALUES SUGGEST THAT A PARCEL LIFTED FROM ABOUT 850MB TO 800MB WOULD
HAVE ABOUT 1500 J/KG TO WORK WITH. WHILE THE EFFECTIVE SHEAR IS
QUITE WEAK SOME NICKEL TO DIME SIZED HAIL WOULD BE POSSIBLE NEAR THE
MISSOURI RIVER. WITH FAIRLY SLOW STORM MOTION ANY STORMS THAT COULD
DEVELOP WOULD HAVE THE POTENTIAL TO PRODUCE SOME HEAVIER RAINFALL.
WILL KEEP THE HIGHEST POPS ALONG THE MISSOURI RIVER INTO NORTHWEST
IOWA OVERNIGHT WITH A TREND DOWNWARD IN RAIN AND THUNDERSTORM
POTENTIAL ON SATURDAY. OTHER THAN CONVECTIVE BLOW OFF OR SOMETHING
THAT ADVECTS IN IT LOOKS LIKE CAPPING WILL KEEP THUNDERSTORMS AT BAY
MOST OF THE DAY IN MOST LOCATIONS. STILL EXPECTING QUITE A BIT OF
CLOUD COVER AND COOL TEMPERATURES...RANGING FROM THE MID 60S EAST OF
THE BUFFALO RIDGE TO 75 TO 80 IN SOUTH CENTRAL SOUTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 332 PM CDT FRI MAY 24 2013
MODELS SUGGEST THAT A PAIR OF WAVES MAY BEGIN NOSING INTO BLACK
HILLS AREA SATURDAY AFTERNOON AND AGAIN SUNDAY AFTERNOON...
TRIGGERING CONVECTION TO OUR WEST SATURDAY EVENING AND SOUTHWEST ON
SUNDAY EVENING. WITH A QUASI-STATIONARY BOUNDARY DRAPED ACROSS THE
REGION...VERY HIGH PRECIPITABLE WATER AMOUNTS THROUGHOUT THE REGION
AND A STRENGTHENING LOW LEVEL JET NEAR THE MISSOURI RIVER BOTH
NIGHTS...EXPECT SHOWER AND THUNDERSTORM POTENTIAL TO PEAK DURING THE
EVENING AND OVERNIGHT HOURS. MAIN CONCERN WITH THIS CONVECTION WOULD BE
LOCALLY HEAVY RAINFALL AMOUNTS AND STRONG WIND GUSTS. MARGINALLY
SEVERE HAIL WILL ALSO BE POSSIBLE...HOWEVER THIS THREAT WOULD BE
MAINLY DURING THE EVENING HOURS. PRECIPITATION CHANCES DO DIMINISH
SLIGHTLY DURING THE DAY ON SUNDAY...BUT WILL KEEP SCATTERED MENTION
GOING THROUGH THE DAY WITH SOME TIMING UNCERTAINTY.
VERY ACTIVE AND WET PATTERN IS EXPECTED TO PERSIST THROUGH THE
ENTIRE MID AND LONG RANGE WITH PRECIPITATION IN THE FORECAST EACH
PERIOD...INCLUDING MEMORIAL DAY. STILL SEEING QUITE A BIT OF
UNCERTAINTY WITH TIMING ALL OF THE SHORTWAVES TRACKING THROUGH THE
REGION ALONG THE GENERAL UPPER LEVEL SOUTHWEST FLOW. WEST COAST
TROUGHING STARTS NUDGING FURTHER EAST INTO THE HIGH PLAINS LATE WEEK
NEXT WEEK...HOWEVER THE SLOW MOVING NATURE OF THIS SYSTEM KEEPS
IT...AND PRECIPITATION IN THE FORECAST EVEN THROUGH NEXT WEEKEND.
TEMPERATURES WILL WARM A LITTLE TO SLIGHTLY ABOVE NORMAL READINGS
AROUND MID WEEK BUT WILL START TO COOL A BIT LATE WEEK WITH POTENTIAL
TROUGHING ARRIVING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 650 PM CDT FRI MAY 24 2013
WILL SEE A BREAK FROM PRECIPITATION THE REMAINDER OF THE EVENING AS
FIRST WAVE SHIFTS EAST OF THE FORECAST AREA. MODELS CONTINUE TO SHOW
CEILINGS DETERIORATING INTO MVFR RANGE LATER TONIGHT AT ALL TAF SITES
WITH AREAS OF IFR CEILINGS AS WELL...SO WILL CONTINUE THIS DOWNWARD
TREND IN CEILINGS AFTER 06Z...WITH NEXT CHANCE OF RAIN EXPANDING
INTO SOUTHERN PARTS OF THE AREA ALONG WITH THE LOWER CEILINGS. SOME
MID LEVEL INSTABILITY PRESENT AS THE RAIN MOVES INTO SOUTHWEST PARTS
OF THE FORECAST AREA...BUT PRECIP MOVES INTO MORE STABLE AIRMASS AS
IT PROGRESSES EASTWARD...LEADING TO MORE ISOLATED THUNDER THREAT
ALONG AND EAST OF I-29 CORRIDOR. THUS HAVE LEFT MENTION OF THUNDER
OUT OF KFSD/KSUX TAFS AT THIS TIME...THOUGH CANNOT COMPLETELY BE
RULED OUT 08Z-15Z. BULK OF MVFR CEILINGS EXPECTED TO BECOME MORE
SCATTERED THROUGH THE LATE MORNING/MIDDAY HOURS SATURDAY...THOUGH
WITH MORE ABUNDANT LOW LEVEL MOISTURE...POTENTIAL FOR MVFR CUMULUS
REDEVELOPING ACROSS THE MISSOURI VALLEY INCLUDING KSUX THROUGH THE
AFTERNOON.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...08
LONG TERM...
AVIATION...JH
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
841 PM CDT FRI MAY 24 2013
.DISCUSSION...18Z GFS/NAM CYCLE MAINTAIN AN UPPER LOW/TROUGH OVER
THE REGION OVERNIGHT MOVG SLOWLY EASTWARD. GFS/NAM ALSO PROG LOW
CIN/SIGNIFICANT CAPE OVER THE CWA/MSA OVERNIGHT. PROXIMITY
SOUNDINGS DEPICT SIGNIFICANT MSTR (BASED ON PWAT VALUES
CONTAMINATION FROM C0NVECTION NOTWITHSTANDING.) WL MAINTAIN LOW
POP CONVECTION FOR OVERNIGHT. THE NAM PROG AROUND 20KT ONSHORE
FLOW OVERNIGHT AT 925MB ALONG WITH POSITIVE 0-1KM LAPSE RATES
ALTHOUGH LESS THAN DRY ADIABATIC. NEVERTHELESS...ANTICIPATE THAT
SFC WIND WL REMAIN IN THE 5-10KT RANGE OVER THE CWA OVERNIGHT
SUFFICIENT TO LIMIT FOG DEVELOPMENT. EXPECT INCREASING LOW LEVEL
CLOUDS AGAIN OVERNIGHT. WIND MAY APPROACH SCEC OVERNIGHT OVER THE
COASTAL WATERS OWING TO THE FOREGOING LAPSE RATES/WIND ALOFT.
&&
.PREV DISCUSSION... /ISSUED 702 PM CDT FRI MAY 24 2013/
DISCUSSION...NOTE AVIATION DISCUSSION BELOW.
AVIATION...ANTICIPATE THAT ISOLD CONVECTION THIS EVENING
GENERALLY EAST OF U.S. ROUTE 281 WL DISSIPATE EARLY TONIGHT. A
TRANSITION TO PREDOMINATE MVFR CEILINGS OVERNIGHT. ANTICIPATE THAT
FOG WILL BE LIMITED OVERNIGHT OWING TO SUFFICIENT SFC WIND. EXPECT
AT LEAST ISOLD CONVECTIVE ACTIVITY TO DEVELOP AGAIN BY MID MORNING
SATURDAY AND CONTINUE THROUGH THE EARLY AFTN BEFORE ENDING FROM
WEST TO EAST. EXPECT SFC WIND TO INCREASE TO MODERATE/BREEZY BY
LATE AFTN.
PREV DISCUSSION... /ISSUED 332 PM CDT FRI MAY 24 2013/
SHORT TERM (TONIGHT)...THIS MORNINGS SOUTHERN MCV ASSISTED IN
THE DEVELOPMENT OF A LINE OF SHOWERS AND THUNDERSTORMS ACROSS THE
WESTERN BRUSH COUNTRY LATE MORNING AND EARLY AFTERNOON. FOLLOWING
CLOSE TO THE HIGH RES 18Z HRRR FOR THE REST OF THIS AFTERNOON AND
EVENING...WHICH WAS THE ONLY MODEL THAT SEEMED TO HAVE A DECENT
HANDLE ON THE SITUATION. THE LINE WILL CONTINUE EAST INTO THE
INLAND COASTAL BEND OVER THE NEXT 2 HOURS...THEN POSSIBLY WEAKEN
AS OUTFLOW BOUNDARY PUSHES OUT AHEAD OF IT (MAY BE EVIDENCE OF
THIS OUTFLOW BOUNDARY ALREADY DEVELOPING. THE ENVIRONMENT ACROSS
THE EASTERN BRUSH COUNTRY AND COASTAL BEND IS UNSTABLE...WITH
MLCAPE 2000-2500 J/KG AND UNCAPPED. SHEAR IS RELATIVELY
WEAK...NEVERTHELESS A FEW STRONGER STORMS PRODUCING SMALL HAIL AND
WIND GUSTS UP TO 50 MPH ARE POSSIBLE OVER THE NEXT COUPLE OF
HOURS. CONVECTION SHOULD GRADUALLY END AROUND OR AFTER SUNSET.
LONG TERM (SATURDAY THROUGH FRIDAY)...WEAK SHORTWAVES WILL CONTINUE
TO AFFECT SOUTH TEXAS ON SATURDAY AND INTO SUNDAY. MODELS ALL
INDICATE ENERGY WITH THESE SHORTWAVES...BUT ARE A BIT DIFFERENT IN
THE FINER DETAILS. STILL THINK THE NEXT WAVE TOMORROW COULD BRING A
SLIGHT CHANCE FOR THUNDERSTORMS TO THE AREA. HAVE SPREAD THE SLIGHT
CHANCE AREA FARTHER EAST GIVEN INCREASED MOISTURE FARTHER EAST THAN
PREVIOUS MODELS HAD INDICATED. HAVE A LINGERING 10 POP WITH SLIGHT
CHANCE WORDING FOR SUNDAY AS A SHORTWAVE WEAKER THAN THE OTHERS
PASSES BY...BUT GUIDANCE STILL INDICATING SOME QPF ACROSS THE AREA.
FOR MONDAY AND TUESDAY HIGH PRESSURE RIDGE BUILDS STRONGER ACROSS
THE AREA WHILE 850 THETA E RIDGE SHIFTS WESTWARD. THIS WILL DRY
THINGS OUT A BIT IN THE MID LEVELS AND ALLOW TEMPERATURES TO
INCREASE. INCREASED PRESSURE GRADIENT WITH RESULTING FROM THE
STRENGTHENING RIDGE TO THE EAST WILL ALSO INCREASE WINDS ACROSS THE
AREA EARLY IN THE WEEK. SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE
BY MID-WEEK.
AN UPPER LEVEL TROUGH WILL BE DIGGING INTO THE WESTERN US BY MID
WEEK AS WELL. MODEL SOLUTIONS HAVE NOT BEEN CONSISTENT WITH THE
AMPLITUDE OF THIS TROUGH. SOME MODELS INDICATE A PRETTY DEEP TROUGH
DIGGING AS FAR SOUTH AS NORTHERN MEXICO. OTHER MODELS SHOW A MUCH
WEAKER TROUGH. NOT CONFIDENT YET IN CHANCES FOR PRECIP
THURSDAY/FRIDAY...BUT WILL LEAVE 20 POPS FROM PREVIOUS FORECAST AT
THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 76 89 75 90 75 / 30 10 10 10 10
VICTORIA 74 88 72 90 71 / 30 20 10 10 10
LAREDO 75 92 74 96 74 / 30 20 10 10 10
ALICE 75 89 73 92 73 / 30 20 10 10 10
ROCKPORT 75 87 75 88 76 / 30 10 10 10 10
COTULLA 74 91 72 95 72 / 30 30 10 10 10
KINGSVILLE 76 90 75 91 74 / 30 10 10 10 10
NAVY CORPUS 75 86 75 87 76 / 30 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
WC/87...SHORT TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
702 PM CDT FRI MAY 24 2013
.DISCUSSION...NOTE AVIATION DISCUSSION BELOW.
&&
.AVIATION...ANTICIPATE THAT ISOLD CONVECTION THIS EVENING
GENERALLY EAST OF U.S. ROUTE 281 WL DISSIPATE EARLY TONIGHT. A
TRANSITION TO PREDOMINATE MVFR CEILINGS OVERNIGHT. ANTICIPATE THAT
FOG WILL BE LIMITED OVERNIGHT OWING TO SUFFICIENT SFC WIND. EXPECT
AT LEAST ISOLD CONVECTIVE ACTIVITY TO DEVELOP AGAIN BY MID MORNING
SATURDAY AND CONTINUE THROUGH THE EARLY AFTN BEFORE ENDING FROM
WEST TO EAST. EXPECT SFC WIND TO INCREASE TO MODERATE/BREEZY BY
LATE AFTN.
&&
.PREV DISCUSSION... /ISSUED 332 PM CDT FRI MAY 24 2013/
SHORT TERM (TONIGHT)...THIS MORNINGS SOUTHERN MCV ASSISTED IN
THE DEVELOPMENT OF A LINE OF SHOWERS AND THUNDERSTORMS ACROSS THE
WESTERN BRUSH COUNTRY LATE MORNING AND EARLY AFTERNOON. FOLLOWING
CLOSE TO THE HIGH RES 18Z HRRR FOR THE REST OF THIS AFTERNOON AND
EVENING...WHICH WAS THE ONLY MODEL THAT SEEMED TO HAVE A DECENT
HANDLE ON THE SITUATION. THE LINE WILL CONTINUE EAST INTO THE
INLAND COASTAL BEND OVER THE NEXT 2 HOURS...THEN POSSIBLY WEAKEN
AS OUTFLOW BOUNDARY PUSHES OUT AHEAD OF IT (MAY BE EVIDENCE OF
THIS OUTFLOW BOUNDARY ALREADY DEVELOPING. THE ENVIRONMENT ACROSS
THE EASTERN BRUSH COUNTRY AND COASTAL BEND IS UNSTABLE...WITH
MLCAPE 2000-2500 J/KG AND UNCAPPED. SHEAR IS RELATIVELY
WEAK...NEVERTHELESS A FEW STRONGER STORMS PRODUCING SMALL HAIL AND
WIND GUSTS UP TO 50 MPH ARE POSSIBLE OVER THE NEXT COUPLE OF
HOURS. CONVECTION SHOULD GRADUALLY END AROUND OR AFTER SUNSET.
LONG TERM (SATURDAY THROUGH FRIDAY)...WEAK SHORTWAVES WILL CONTINUE
TO AFFECT SOUTH TEXAS ON SATURDAY AND INTO SUNDAY. MODELS ALL
INDICATE ENERGY WITH THESE SHORTWAVES...BUT ARE A BIT DIFFERENT IN
THE FINER DETAILS. STILL THINK THE NEXT WAVE TOMORROW COULD BRING A
SLIGHT CHANCE FOR THUNDERSTORMS TO THE AREA. HAVE SPREAD THE SLIGHT
CHANCE AREA FARTHER EAST GIVEN INCREASED MOISTURE FARTHER EAST THAN
PREVIOUS MODELS HAD INDICATED. HAVE A LINGERING 10 POP WITH SLIGHT
CHANCE WORDING FOR SUNDAY AS A SHORTWAVE WEAKER THAN THE OTHERS
PASSES BY...BUT GUIDANCE STILL INDICATING SOME QPF ACROSS THE AREA.
FOR MONDAY AND TUESDAY HIGH PRESSURE RIDGE BUILDS STRONGER ACROSS
THE AREA WHILE 850 THETA E RIDGE SHIFTS WESTWARD. THIS WILL DRY
THINGS OUT A BIT IN THE MID LEVELS AND ALLOW TEMPERATURES TO
INCREASE. INCREASED PRESSURE GRADIENT WITH RESULTING FROM THE
STRENGTHENING RIDGE TO THE EAST WILL ALSO INCREASE WINDS ACROSS THE
AREA EARLY IN THE WEEK. SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE
BY MID-WEEK.
AN UPPER LEVEL TROUGH WILL BE DIGGING INTO THE WESTERN US BY MID
WEEK AS WELL. MODEL SOLUTIONS HAVE NOT BEEN CONSISTENT WITH THE
AMPLITUDE OF THIS TROUGH. SOME MODELS INDICATE A PRETTY DEEP TROUGH
DIGGING AS FAR SOUTH AS NORTHERN MEXICO. OTHER MODELS SHOW A MUCH
WEAKER TROUGH. NOT CONFIDENT YET IN CHANCES FOR PRECIP
THURSDAY/FRIDAY...BUT WILL LEAVE 20 POPS FROM PREVIOUS FORECAST AT
THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 76 89 75 90 75 / 30 10 10 10 10
VICTORIA 74 88 72 90 71 / 30 20 10 10 10
LAREDO 75 92 74 96 74 / 30 20 10 10 10
ALICE 75 89 73 92 73 / 30 20 10 10 10
ROCKPORT 75 87 75 88 76 / 30 10 10 10 10
COTULLA 74 91 72 95 72 / 30 30 10 10 10
KINGSVILLE 76 90 75 91 74 / 30 10 10 10 10
NAVY CORPUS 75 86 75 87 76 / 30 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
WC/87...AVIATION
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1047 PM CDT FRI MAY 24 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 248 PM CDT FRI MAY 24 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM HUDSON BAY TO LAKE MICHIGAN TO THE
CENTRAL GULF COAST. A FEW STRANDS OF CIRRUS IS INVADING NW
WISCONSIN EARLY THIS AFTERNOON...BUT OTHERWISE...CLEAR AND COOL
CONDITIONS ARE PREVAILING. LOOKING UPSTREAM...STRENGTHENING RETURN
FLOW OVER THE PLAINS IS CREATING A BAND OF SHOWERS AND
THUNDERSTORMS OVER EASTERN NORTH AND SOUTH DAKOTA. AS THIS WARM
FRONT SHIFTS EAST TONIGHT...PRECIP CHANCES ARE THE MAIN FORECAST
CONCERN.
TONIGHT...A JET STREAK...BETWEEN A SE DIVING SHORTWAVE OVER THE
EASTERN GREAT LAKES AND A MID-LEVEL RIDGE OVER THE GREAT
PLAINS...WILL SLIDE SOUTHEAST ACROSS THE REGION. RIGHT REAR QUAD OF
THIS JET STREAK WILL SHIFT OVER NORTH-CENTRAL AND NORTHEAST
WISCONSIN AFTER MIDNIGHT. DESPITE VERY DRY AIR IN THE LOW
LEVELS...MODELS SPIT OUT A COUPLE BANDS OF PRECIP AS A RESULT OF
MID-LEVEL CONVERGENCE/FGEN AND UPPER DIVERGENCE...THOUGH DIFFER IN
THEIR PLACEMENT. THE LARGEST BAND WILL BE TIED TO THE PRIMARY
BAROCLINIC ZONE OFF TO OUR WEST AND SOUTHWEST...WHICH THE NAM/GFS
HAVE TRENDED A BIT TO THE WEST. HOWEVER...THE 12Z MESOMODELS
CONTINUE TO PUSH THIS BAND OF PRECIP OVER CENTRAL WISCONSIN BETWEEN
06Z AND 12Z. DO NOT HAVE A GOOD FEEL WHERE THIS BAND WILL END UP.
BUT LIGHT LOW LEVEL SE WINDS WILL SUPPLY A STEADY DIET OF DRY
AIR...SO PRECIP WILL HAVE TO FALL OUT OF A MID-DECK...AND GIVEN THE
WEAK FORCING...CANNOT SEE MUCH MORE THAN SPRINKLES LIKE THE PREVIOUS
FORECASTER MENTIONED. GIVEN THE LOW IMPACT AND TO MATCH UP WITH
OFFICES TO THE WEST AND NORTH...WILL KEEP THE MENTION OF SPRINKLES
OVER CENTRAL WISCONSIN. A LOWERING CLOUD DECK WILL KEEP TEMPS WARMER THAN
LAST NIGHT AND WILL GO WITH MID 30S NORTH TO MID 40S SOUTH. PATCHY
FROST WILL REMAIN POSSIBLE OVER FAR NORTHERN WISCONSIN.
SATURDAY...RIGHT REAR QUAD WILL SLIDE TO THE SOUTH-CENTRAL GREAT
LAKES DURING THE MORNING. ANY SPRINKLE ACTIVITY SHOULD BE ENDING
EARLY SO IT DOES NOT SEEM WORTH MENTIONING IN THE FORECAST. THE
DEPARTING MID-LEVEL CONVERGENCE SHOULD ALLOW DRY AIR TO RETURN TO
NORTHEAST WISCONSIN LATE MORNING ONWARD WHEN SHOULD SEE DECREASING
CLOUDS. CLOUDS TO HANG LONGER OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN...CLOSER TO THE PRIMARY BAROCLINIC ZONE. WITH THE
ADDITIONAL CLOUD COVER...TEMPS TO REMAIN NEAR OR SLIGHTLY COOLER
THAN TODAYS READINGS...AND WILL RANGE FROM THE UPPER 50S OVER
CENTRAL WISCONSIN TO THE MIDDLE 60S OVER NORTHEAST WISCONSIN.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 248 PM CDT FRI MAY 24 2013
GOOD AGREEMENT BETWEEN GUIDANCE IN BIG PICTURE WITH STRENGTHENING
RIDGE IN THE EAST WHILE TROF PERSISTS OVER THE WEST. PLEASANT
WEATHER IS EXPECTED THROUGH MUCH OF THIS MEMORIAL DAY WEEKEND.
AT THE SURFACE DRY HIGH PRESSURE TO THE EAST WILL MAINTAIN EAST TO
SOUTHEAST FLOW OVER THE REGION. SOME MODEL DISCONNECT WITH HOW
HANDLE SHORT WAVE ACTIVITY EXITING WESTERN TROF INTO THE PLAINS
AND WESTERN LAKES LATE THIS HOLIDAY PERIOD. HAVE STAYED TOWARD
DRIER EC/GFS...WITH IDEA THAT HIGH WILL KEEP PCPN TO OUR SOUTHWEST
SUN AND MON. NAM APPEARS THE OUTLIER...TOO STRONG AND FAST. LIGHT
WINDS AND DRY CONDITIONS TO LEAD TO ANOTHER COOL NIGHT FOR
NORTHEAST WI...WITH PATCHY FROST OVER PARTS OF FAR NORTHEAST WI.
TROF DEEPENS WEST BEGINNING OF NEXT WEEK PUMPING UP RIDGE JUST TO
OUR EAST. THIS TO LEAD TO WARMER TEMPS AND INCREASING HUMIDITY AND
INSTABILITY AS WARM FRONT LIFTS NORTH TOWARDS...OR THROUGH STATE.
AGAIN SOME DISPARITY ON HOW FAR NORTH FRONT WILL GO...WITH EC
LINGERING IT OVER NORTHERN WI. COULD BE LOOKING A PERIOD OF ACTIVE
WEATHER NEXT WED/THU WITH POSSIBILITY OF PERIODS OF HEAVY RAINFALL
AS PW`S INCREASE TO 1.5.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1045 PM CDT FRI MAY 24 2013
MIDDLE AND HIGH CLOUDS WILL MOVE INTO THE AREA OVERNIGHT AND EARLY
SATURDAY AND COULD PRODUCE VIRGA OR A BRIEF LIGHT SHOWER OVER CENTRAL
OR NORTHCENTRAL WISCONSIN WHILE REMAINING VFR. MOSTLY SUNNY SKIES
FORECAST FOR SATURDAY AFTERNOON WITH RELATIVELY LIGHT SURFACE WINDS.
GOOD FLYING WEATHER SHOULD CONTINUE THROUGH AT LEAST SUNDAY NIGHT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......TE
AVIATION.......RDM
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
943 PM CDT FRI MAY 24 2013
.UPDATE...
HAVE BROUGHT SLIGHT CHANCE POPS INTO THE FAR WEST A BIT EARLIER THAN
PREVIOUS FORECAST...AND MAY HAVE TO UP THE PROBABILITIES IF THE BAND
OF SHOWERS AND A FEW THUNDERSTORMS HOLD TOGETHER. THE WARM AIR
ADVECTION BAND...TRACKING WITH 700MB FRONTOGENETIC FORCING AND
ISENTROPIC LIFT...WILL REACH FAR WESTERN SECTIONS OF IOWA AND
LAFAYETTE COUNTIES BETWEEN 11 PM AND 1115 PM. LATEST NAM AND HI-
RES SHORT TERM MODELS CONTINUE TO SHOW THE PRECIPITATION
WEAKENING/DIMINISHING AS IT MOVES AWAY FROM THE NARROW BAND OF
BETTER FORCING AND LOWER CONDENSATION PRESSURE DEFICITS BACK TO
THE WEST CLOSER TO THE FOCUSED 850-700 MB WRM ADVECTION.
&&
.AVIATION/06Z TAFS/...
WILL KEEP VFR CONDITIONS THROUGH THE FORECAST. WATCHING POTENTIAL
FOR LIGHT RAIN SHOWERS TO REACH KMSN AROUND/AFTER 09Z...HOWEVER
LATEST RAP SOUNDINGS STILL SHOW THE WARM ADVECTION ONLY MOISTENING
THE COLUMN DOWN TO AROUND 6-7K FT...AND VERY DRY BELOW THAT...SO
ONLY EXPECTING SPRINKLES AT BEST FOR NOW. INFLUENCE OF HIGH
PRESSURE WILL HOLD ANY PRECIPITATION OFF TO THE SOUTHWEST PORTION
OF THE CWA...SOUTHWEST OF KLNR OT KJVL...FOR THE REMAINDER OF THE FORECAST.
&&
.PREV DISCUSSION... /ISSUED 315 PM CDT FRI MAY 24 2013/
VERY SHORT TERM...TONIGHT AND SATURDAY.
SHORT RANGE MODELS SHOW HIGH PRESSURE SLOWLY SHIFTING EAST OF THE
AREA TONIGHT AND SATURDAY. MODELS ARE TRYING TO BRING THE 850MB
FOCUSED WARM AIR ADVECTION NORTHEAST INTO THE SOUTHWESTERN PORTIONS
OF THE AREA THIS EVENING...THEN IS SHUNTED FURTHER TO THE SOUTHWEST
LATER TONIGHT. THIS AREA THEN GRADUALLY PUSHES BACK TOWARD THE
SOUTHWEST PORTIONS OF THE AREA SATURDAY.
850MB LOW LEVEL JET NOSE FOCUSES WEST OF THE AREA TONIGHT...BEFORE
POINTING MORE INTO CENTRAL TO NORTHEAST IOWA SATURDAY. SOME
DISAGREEMENT AMONG THE MODELS WITH THE PLACEMENT OF THESE 850MB
FEATURES...AND SUBSEQUENT QPF. ECMWF MOST AGGRESSIVE WITH QPF ACROSS
THE SOUTHWEST HALF OF THE AREA TONIGHT...WITH THE OTHERS MAINLY DRY.
THE NAM IS MOST AGGRESSIVE SATURDAY IN A SIMILAR AREA...WITH THE
OTHER MODELS MAINLY DRY.
GIVEN THE DRY AIR LINGERING IN THE LOW LEVELS WITH THE HIGH TO THE
EAST...WILL LIMIT POPS TO MAINLY THE SOUTH CENTRAL COUNTIES LATER
TONIGHT AND SATURDAY. SHOULD SEE BROKEN TO OVERCAST MID LEVEL CLOUDS
SPREAD ACROSS MOST OF THE AREA LATER TONIGHT AND SATURDAY. THESE
SHOULD LIMIT LOWS TONIGHT AND LIMIT HIGHS ON SATURDAY.
SHORT TERM...SATURDAY NIGHT THROUGH MONDAY.
12Z NAM APPEARS TO BE OUTLIER WITH REGARDS TO MORE NORTHERN
PLACEMENT OF WARM FRONT AND MESO-SCALE CONVECTIVE SYSTEM OVER
CENTRAL WI SUN NGT AS BAROCLINIC ZONE AND ENHANCED LOW LEVEL
CONVERGENCE LIKELY TO BE FURTHER SOUTH AND WEST. NEVER THE
LESS...WL CONTINUE TO KEEP SMALL POPS SOUTH AND WEST OF MADISON SAT
NGT AND SUN DUE TO NEARBY BAROCLINIC ZONE. BETTER THREAT FOR
CONVECTION SUN NGT INTO MONDAY AS NORTHERN EXTENT OF BAROCLINIC
ZONES SHIFTS NORTHEAST INTO THE VICINITY ALONG WITH PIECES OF
UPSTREAM MCS-INDUCED VORTICITY MOVING NORTHEAST ACROSS SOUTHERN WI.
PERSISTENT SOUTHEAST SFC WINDS AND PLENTY OF CLOUDS WILL KEEP TEMPS
IN CHECK FOR THE HOLIDAY WEEKEND.
LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
SHARPENING UPSTREAM LONG WAVE TROFFING OVER WRN CONUS IS EXPECTED
EARLY NEXT WEEK AS VIGOROUS PIECE OF ENERGY SLIDES INTO BASE OF
TROUGH. THIS WILL RESULT IN INCREASING SOUTHERLY MID LEVEL WINDS
WHICH WILL CONTRIBUTE TO THE STRONG FRONTAL BOUNDARY OVER THE
CENTRAL CONUS SHIFTING NORTHWARD. MEDIUM RANGE GUIDANCE IN GENERAL
AGREEMENT HOWEVER DIFFERENCES OF TIMING OF WARM FRONT PROGRESSION
DUE TO AMOUNT AND AREAL EXTENT OF CONVECTION FIRING ALONG AND NORTH
OF FRONT IN BAROCLINIC ZONE. BY 00Z/WED...GEM AND GFS HAS PUSHED
WMFNT INTO NRN WI WHILE ECMWF HAS FRONT STILL SUPPRESSED TO THE
SOUTH. BEST CHANCE FOR MORE WIDESPREAD CONVECTION ALONG AND AHEAD
OF NORTHWARD MOVING WMFNT DURING THIS PERIOD...HENCE HIGHEST CHANCE
POPS MONDAY NIGHT INTO TUESDAY.
NEARBY CONVECTION VCNTY OF WMFNT COULD AFFECT PORTIONS OF SRN WI
LATER PERIODS...ESPECIALLY AT NIGHT...AS CAPPING INVERSION SHOULD
PREVENT MOST DAYTIME ACTIVITY. MORE SUMMER-LIKE TEMPS AND HUMIDITY
SHOULD SETTLE IN DURING THIS PERIOD AS WELL. LATER SHIFTS MAY BE
NUDING MAX TEMPS FURTHER INTO THE 80S.
THREAT FOR STRONGER CONVECTION LATE NEXT WEEK INTO THE FIRST DAYS OF
JUNE AS UPPER LEVEL TROUGH MOVES NORTHEAST THROUGH THE REGION.
AVIATION /00Z TAFS/...VFR CONDITIONS ARE EXPECTED TONIGHT AND
SATURDAY ACROSS TAF SITES. ANY PRECIPITATION SHOULD REMAIN SOUTHWEST
OF THE AREA THROUGH THIS PERIOD...AS HIGH PRESSURE SLOWLY SHIFTS TO
THE EAST. SHOULD SEE BROKEN TO OVERCAST MID LEVEL CLOUDS SHIFT
SOUTHEAST INTO THE AREA LATER TONIGHT AND LINGER INTO SATURDAY.
NORTHEAST WINDS AT THE EASTERN TAF SITES LATE THIS AFTERNOON WILL
WEAKEN AND SHIFT SOUTHEAST TONIGHT INTO SATURDAY. LIGHT WINDS WILL
BECOME SOUTHEAST TONIGHT AND SATURDAY AT MADISON.
MARINE...
SMALL CRAFT ADVISORY FOR HIGH WAVES ACROSS THE SOUTHERN TWO
NEARSHORE MARINE ZONES HAS BEEN CANCELLED. NORTHEAST WINDS WILL
CONTINUE TO SLOWLY DIMINISH LATE THIS AFTERNOON INTO THE
EVENING...AS HIGH PRESSURE SLOWLY MOVES EAST. THIS HAS ALLOWED ANY
REMAINING HIGH WAVES TO SUBSIDE TO UNDER 4 FEET.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...REM
TONIGHT/SATURDAY AND AVIATION/MARINE...WOOD
SATURDAY NIGHT THROUGH FRIDAY...MBK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
715 PM CDT FRI MAY 24 2013
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 248 PM CDT FRI MAY 24 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM HUDSON BAY TO LAKE MICHIGAN TO THE
CENTRAL GULF COAST. A FEW STRANDS OF CIRRUS IS INVADING NW
WISCONSIN EARLY THIS AFTERNOON...BUT OTHERWISE...CLEAR AND COOL
CONDITIONS ARE PREVAILING. LOOKING UPSTREAM...STRENGTHENING RETURN
FLOW OVER THE PLAINS IS CREATING A BAND OF SHOWERS AND
THUNDERSTORMS OVER EASTERN NORTH AND SOUTH DAKOTA. AS THIS WARM
FRONT SHIFTS EAST TONIGHT...PRECIP CHANCES ARE THE MAIN FORECAST
CONCERN.
TONIGHT...A JET STREAK...BETWEEN A SE DIVING SHORTWAVE OVER THE
EASTERN GREAT LAKES AND A MID-LEVEL RIDGE OVER THE GREAT
PLAINS...WILL SLIDE SOUTHEAST ACROSS THE REGION. RIGHT REAR QUAD OF
THIS JET STREAK WILL SHIFT OVER NORTH-CENTRAL AND NORTHEAST
WISCONSIN AFTER MIDNIGHT. DESPITE VERY DRY AIR IN THE LOW
LEVELS...MODELS SPIT OUT A COUPLE BANDS OF PRECIP AS A RESULT OF
MID-LEVEL CONVERGENCE/FGEN AND UPPER DIVERGENCE...THOUGH DIFFER IN
THEIR PLACEMENT. THE LARGEST BAND WILL BE TIED TO THE PRIMARY
BAROCLINIC ZONE OFF TO OUR WEST AND SOUTHWEST...WHICH THE NAM/GFS
HAVE TRENDED A BIT TO THE WEST. HOWEVER...THE 12Z MESOMODELS
CONTINUE TO PUSH THIS BAND OF PRECIP OVER CENTRAL WISCONSIN BETWEEN
06Z AND 12Z. DO NOT HAVE A GOOD FEEL WHERE THIS BAND WILL END UP.
BUT LIGHT LOW LEVEL SE WINDS WILL SUPPLY A STEADY DIET OF DRY
AIR...SO PRECIP WILL HAVE TO FALL OUT OF A MID-DECK...AND GIVEN THE
WEAK FORCING...CANNOT SEE MUCH MORE THAN SPRINKLES LIKE THE PREVIOUS
FORECASTER MENTIONED. GIVEN THE LOW IMPACT AND TO MATCH UP WITH
OFFICES TO THE WEST AND NORTH...WILL KEEP THE MENTION OF SPRINKLES
OVER CENTRAL WISCONSIN. A LOWERING CLOUD DECK WILL KEEP TEMPS WARMER THAN
LAST NIGHT AND WILL GO WITH MID 30S NORTH TO MID 40S SOUTH. PATCHY
FROST WILL REMAIN POSSIBLE OVER FAR NORTHERN WISCONSIN.
SATURDAY...RIGHT REAR QUAD WILL SLIDE TO THE SOUTH-CENTRAL GREAT
LAKES DURING THE MORNING. ANY SPRINKLE ACTIVITY SHOULD BE ENDING
EARLY SO IT DOES NOT SEEM WORTH MENTIONING IN THE FORECAST. THE
DEPARTING MID-LEVEL CONVERGENCE SHOULD ALLOW DRY AIR TO RETURN TO
NORTHEAST WISCONSIN LATE MORNING ONWARD WHEN SHOULD SEE DECREASING
CLOUDS. CLOUDS TO HANG LONGER OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN...CLOSER TO THE PRIMARY BAROCLINIC ZONE. WITH THE
ADDITIONAL CLOUD COVER...TEMPS TO REMAIN NEAR OR SLIGHTLY COOLER
THAN TODAYS READINGS...AND WILL RANGE FROM THE UPPER 50S OVER
CENTRAL WISCONSIN TO THE MIDDLE 60S OVER NORTHEAST WISCONSIN.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 248 PM CDT FRI MAY 24 2013
GOOD AGREEMENT BETWEEN GUIDANCE IN BIG PICTURE WITH STRENGTHENING
RIDGE IN THE EAST WHILE TROF PERSISTS OVER THE WEST. PLEASANT
WEATHER IS EXPECTED THROUGH MUCH OF THIS MEMORIAL DAY WEEKEND.
AT THE SURFACE DRY HIGH PRESSURE TO THE EAST WILL MAINTAIN EAST TO
SOUTHEAST FLOW OVER THE REGION. SOME MODEL DISCONNECT WITH HOW
HANDLE SHORT WAVE ACTIVITY EXITING WESTERN TROF INTO THE PLAINS
AND WESTERN LAKES LATE THIS HOLIDAY PERIOD. HAVE STAYED TOWARD
DRIER EC/GFS...WITH IDEA THAT HIGH WILL KEEP PCPN TO OUR SOUTHWEST
SUN AND MON. NAM APPEARS THE OUTLIER...TOO STRONG AND FAST. LIGHT
WINDS AND DRY CONDITIONS TO LEAD TO ANOTHER COOL NIGHT FOR
NORTHEAST WI...WITH PATCHY FROST OVER PARTS OF FAR NORTHEAST WI.
TROF DEEPENS WEST BEGINNING OF NEXT WEEK PUMPING UP RIDGE JUST TO
OUR EAST. THIS TO LEAD TO WARMER TEMPS AND INCREASING HUMIDITY AND
INSTABILITY AS WARM FRONT LIFTS NORTH TOWARDS...OR THROUGH STATE.
AGAIN SOME DISPARITY ON HOW FAR NORTH FRONT WILL GO...WITH EC
LINGERING IT OVER NORTHERN WI. COULD BE LOOKING A PERIOD OF ACTIVE
WEATHER NEXT WED/THU WITH POSSIBILITY OF PERIODS OF HEAVY RAINFALL
AS PW`S INCREASE TO 1.5.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 715 PM CDT FRI MAY 24 2013
VFR CONDITIONS EXPECTED TONIGHT AND SATURDAY WITH
MIDDLE AND HIGH CLOUDS AT TIMES. IT IS NOT OUT OF THE QUESTION TO
SEE VIRGA OR A LIGHT RAIN SHOWER OVER NORTH CENTRAL AND CENTRAL
WISCONSIN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......TE
AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
646 PM CDT FRI MAY 24 2013
.UPDATE...THIS EVENING
ISSUED AT 646 PM CDT FRI MAY 24 2013
QUICK UPDATE TO REFLECT THE FASTER TIMING OF PRECIPITATION
CURRENTLY ACROSS WESTERN/CENTRAL MINNESOTA. THIS ACTIVITY IS
RIDING ALONG MID LEVEL FRONTOGENESIS AND WARM AIR
ADVECTION...AND COMBINED WITH SOME DECENT UPPER LEVEL FORCING / PV
ADVECTION. MOST OF THE MESO-MODELS AND 18Z GUIDANCE SHOWS THIS
SLIDING SOUTH/EAST MAINLY ALONG AND WEST OF THE MISSISSIPPI RIVER
THROUGH THE OVERNIGHT. SO HAVE SPED UP PRECIPITATION WORDING TO
ACCOUNT FOR THIS. OTHERWISE...FORECAST REMAINS ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 334 PM CDT FRI MAY 24 2013
AT 3 PM...A 1003 MB HIGH PRESSURE SYSTEM...CENTERED OVER LAKE
MICHIGAN...KEPT SKIES PARTLY SUNNY ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY. MEANWHILE FURTHER WEST...A SHORT WAVE WAS PRODUCING
SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN QUARTER OF THE
DAKOTAS AND WESTERN MINNESOTA. THE MESO AND DETERMINISTIC MODELS ARE
CONTINUING TO STRUGGLE WITH THE EASTWARD PROGRESS OF THIS
PRECIPITATION TONIGHT. THE ECMWF AND HRRR MOVE THIS PRECIPITATION
ACROSS MOST OF FORECAST AREA BY 25.06Z. MEANWHILE THE
NMM...ARW...GFS...GEM...RAP... AND NAM MAINLY CONFINE THE
PRECIPITATION WEST OF THE MISSISSIPPI RIVER THIS EVENING...AND
THEN MOVES IT ACROSS THE REMAINDER OF THE AREA OVERNIGHT. SINCE
THE CONVECTION ACROSS THE DAKOTAS WILL BE MOVING INTO AN AREA WITH
LESS FRONTOGENETIC FORCING...MOISTURE TRANSPORT...WEAK ISENTROPIC
LIFT...AND DRIER AIR...DECIDED TO TREND THE FORECAST TOWARD THE
LATTER MODEL SET. IN ADDITION...THE RADAR ECHOS ACROSS WESTERN
MINNESOTA ARE SHOWING A DECREASING TREND. EVEN BY DOING
THIS...THERE IS SOME VARIATIONS AMONGST THEM...SO TRIED TO GO WITH
AN ENSEMBLE APPROACH WHEN ASSIGNING THE HOURLY PRECIPITATION
CHANCES. THE HIGHEST PRECIPITATION CHANCE AND AMOUNTS /UP TO A
HALF INCH/ WILL BE FOUND ACROSS ACROSS SOUTHEAST MINNESOTA AND
NORTHEAST IOWA.
ON SATURDAY...THE SHORT WAVE WILL MOVE EAST SOUTHEAST ACROSS IOWA.
AS THIS OCCURS...THE 850 MB MOISTURE TRANSPORT AND ISENTROPIC LIFT
WILL GRADUALLY WEAKEN. AS A RESULT...WENT WITH A DECREASING TREND
IN THE PRECIPITATION TRENDS FROM LATE MORNING INTO THE AFTERNOON.
ADDITIONAL RAINFALL AMOUNTS WILL BE LESS THAN 2 TENTHS OF AN INCH.
WITH THE 24.12Z AND 24.18Z MODELS IN GOOD AGREEMENT THAT THERE
WILL BE LESS THAN 100 J/KG CAPES...JUST KEPT AN ISOLATED
THUNDERSTORM CHANCE MAINLY WEST AND SOUTH IF THE INTERSTATE 94
CORRIDOR.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 PM CDT FRI MAY 24 2013
FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT...THE WARM FRONT WILL
REMAIN WELL SOUTHWEST OF THE FORECAST AREA. AS A RESULT...
SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST WISCONSIN
WILL REMAIN CLOUDY WITH PERIODIC SHOWERS AND MAYBE AN ISOLATED
THUNDERSTORM. OVER THE PAST 3 DAYS...THE CONSALL HAS CONTINUED
TO TREND TOWARD COOLER HIGH TEMPERATURES FOR SUNDAY. IT NOW HAS
HIGH TEMPERATURES AROUND 60. MEANWHILE THE ECMWF ONLY HAS HIGH
TEMPERATURES IN THE LOWER 50S FOR THESE AREAS. SINCE THE ECMWF
TYPICALLY VERIFIES THE BEST FOR THIS TIME PERIOD...WENT WITH A
BLEND OF THE CONSALL...CONSALLBC...AND ECMWF.
FROM MEMORIAL DAY INTO TUESDAY...THE MODELS ARE CONTINUING TO SHOW
THAT A WARM FRONT WILL MOVE NORTHWARD INTO THE AREA. THIS WILL
ALLOW ML CAPES TO CLIMB INTO THE 1K TO 3K J/KG RANGE. AS A
RESULT...EXPECT THE THUNDERSTORM CHANCES TO INCREASE DURING THIS
TIME PERIOD. THE 0-3KM SHEAR WOULD BE FAVORABLE FOR THE
POSSIBILITY THAT A FEW THUNDERSTORMS MAY BE CAPABLE OF PRODUCING
LARGE HAIL AND DAMAGING WINDS.
FROM TUESDAY NIGHT INTO FRIDAY...THE MODELS CONTINUE TO STRUGGLE
ON WHERE THE WARM SECTOR WILL BE LOCATED. THIS GREATLY AFFECTS
THE WHERE THE PRECIPITATION MAY BE LOCATED. IN ADDITION...IT WILL
ALSO AFFECT THE SHEAR AND INSTABILITY...THUS...THERE IS A LOT OF
UNCERTAINTY ON WHETHER THERE WILL BE ANY SEVERE WEATHER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 646 PM CDT FRI MAY 24 2013
RAIN SHOWERS AND ISOLATED THUNDERSTORMS WORKING EAST ACROSS
CENTRAL MINNESOTA...WITH SCATTERED SPRINKLES OUT AHEAD OF THE MAIN
BAND. THIS WILL IMPACT KRST BY 01Z...AND 03Z KLSE. INSTABILITY IS
VERY LIMITED AND DROPS OFF VERY QUICKLY ACROSS THE AREA...SO
THUNDER CHANCES ARE VERY LOW. THE RAIN IS FALLING OUT OF 10 KFT
BASES MOSTLY...AND THESE VFR CONDITIONS SHOULD PREVAIL THROUGH
MOST OF THE OVERNIGHT. AS THE ATMOSPHERE MOISTENS AND
SATURATES...A LOWERING TO MVFR IS POSSIBLE AT KRST BY 14Z SATURDAY.
AT KLSE...ONLY LOW-END VFR CEILINGS ARE EXPECTED. VISIBILITIES
SHOULD REMAIN VFR...EVEN IN THE RAIN SHOWERS. MOST OF THE FORECAST
MODELS SHOW THE BACK-EDGE OF RAIN SHOWERS CROSSING THE AREA
BETWEEN 15 AND 18Z SATURDAY...SO HAVE INTRODUCED THAT TREND.
CEILINGS WILL HANG ON THROUGHOUT THE REMAINDER OF THE PERIOD
HOWEVER.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...ZT
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1133 PM CDT WED MAY 22 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 902 PM CDT WED MAY 22 2013
SLOW MOVING AREA OF LIGHT RAIN ASSOCIATED WITH PESKY
MID-LEVEL CIRCULATION AND ASSOCIATED DEFORMATION SLOWLY WANING
AND BECOMING INCREASINGLY DISORGANIZED AS NORTHERLY FLOW AND
SUBSIDENCE INCREASES UPSTREAM. GOING SHORT-TERM FORECAST STILL
LOOKING ON TRACK. LAST FEW RUNS OF THE HRRR SEEM TO HAVE A DECENT
HANDLE ON THE DEMISE OF THIS SYSTEM WITH PRECIPITATION ENDING FROM
NORTHWEST TO SOUTHEAST OVERNIGHT. EXPECT BACK EDGE OF WEAKENING
PRECIPITATION SHIELD TO MOVE SOUTHEAST OF THE FORECAST AREA BY
AROUND 10Z OR 11Z FOLLOWED BY CLEARING SKIES AFTER 15Z THURSDAY.
EXPECT NORTHEAST WINDS TO INCREASE OVERNIGHT WITH A FEW GUSTS OF
25 TO 30 MPH MAINLY OVER THE FOX VALLEY FROM GREEN BAY SOUTH TO
OSHKOSH.
&&
.SYNOPSIS...
ISSUED AT 233 PM CDT WED MAY 22 2013
UPPER LEVEL SYSTEM THAT HAS BEEN SITTING OVER THE NORTHERN PLAINS
THE PAST FEW DAYS WAS FINALLY MOVING EAST...WITH THE SFC LOW
PRESSURE SLIDING THROUGH SOUTHERN WISCONSIN THIS AFTERNOON PER
MSAS ANALYSIS. THIS SFC LOW...COMBINED WITH ENERGY FROM A POTENT
SHORTWAVE THAT WAS SWINGING AROUND THE SOUTHEAST SIDE OF THE
UPPER LEVEL TROUGH INTO THE GREAT LAKES AREA...RESULTED IN
WIDESPREAD SHOWERS THIS AFTERNOON. SOME LIGHTNING WAS ALSO
DETECTED IN THIS AREA OF PRECIP...MAINLY IN THE VICINITY OF A NOSE
OF MINOR MU-CAPES AND THE BEST FORCING. SHOWERS HAVE BECOME MORE
NUMEROUS THROUGH THE MORNING AND AFTERNOON AS A DECENT 300MB JET
STREAK MOVED OVER THE STATE...WITH NORTHEAST WISCONSIN SITTING IN
THE RIGHT REAR QUAD. EVEN THOUGH SFC WINDS WERE OUT OF THE EAST TO
NORTHEAST...THIS MORNINGS 12Z SOUNDING OUT OF GRB AND DVN SHOWED
SOUTHWEST FLOW ALOFT...WHICH HELPED CONTINUE TO PUMP MOISTURE
INTO SOUTHERN PORTIONS OF THE CWA. PRECIPITABLE WATER VALUES IN
THIS AREA INCREASED THROUGH THE MORNING AND OCCASIONAL MODERATE TO
HEAVY RAIN WAS REPORTED IN SOME LOCATIONS JUST SOUTH OF OSHKOSH
AND FDL. FURTHER NORTH...SKIES REMAINED CLOUDY BUT NO PRECIP WAS
REPORTED. EXPECT SHOWERS AND ISOLATED THUNDERSTORMS TO CONTINUE TO
PUSH NORTH AND OVERSPREAD THE AREA THROUGH THE REST OF THE
AFTERNOON...WITH PORTIONS OF EASTERN AND CENTRAL WISCONSIN SEEING
OCCASIONAL MODERATE TO HEAVY RAINFALL AS THE BEST FORCING MOVES
THROUGH THE STATE WITH THE MAIN UPPER LEVEL TROUGH.
&&
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 233 PM CDT WED MAY 22 2013
MAIN FORECAST CONCERN WILL BE PRECIPITATION TRENDS TONIGHT AND
EARLY THURSDAY MORNING. OTHERWISE...SKIES WILL CLEAR FROM
NORTHWEST TO SOUTHEAST AS HIGH PRESSURE MOVES IN FROM CANADA ON
THURSDAY.
PRECIPITATION SHOULD OVERSPREAD THE ENTIRE AREA LATE THIS
AFTERNOON...REACHING THE UPPER PENINSULA BORDER BY 21Z-00Z.
GENERALLY SHOWERY CONDITIONS WILL PERSIST THROUGH THE EARLY
OVERNIGHT HOURS FOR THE CWA...WITH SOME MODERATE RAIN POSSIBLE IN
EASTERN WISCONSIN. THERE HAS BEEN A CONSISTENT SIGNAL FROM THE
MODELS FOR STRONG FORCING 21Z TODAY THROUGH 03Z TONIGHT IN CENTRAL
AND EAST CENTRAL WISCONSIN...AND EXPECT THIS TIME FRAME TO BE WHEN
WE WILL SEE THE HEAVIEST AND MOST WIDESPREAD RAINFALL. BUMPED UP
QPF A LITTLE IN EASTERN WISCONSIN FROM 00Z TO 06Z THURSDAY TO
ACCOUNT FOR POSSIBLE HEAVIER SHOWERS WITH THIS FORCING. CONTINUED
TO KEEP ISOLATED THUNDER IN THE FCST UNTIL 03Z THURSDAY AS
WELL...AT WHICH POINT ANY LINGERING MU-CAPE OVER 500 J/KG WILL
DISSIPATE AND THE BEST FORCING WILL MOVE AWAY FROM WISCONSIN...SO
PRECIPITATION WILL BE MAINLY SHOWERS.
DRY AIR WILL RUSH IN BEHIND THE UPPER LEVEL SYSTEM LATE TONIGHT
AND SHOULD QUICKLY USHER OUT PRECIPITATION. THIS COMBINED WITH
STRONG SUBSIDENCE WILL RESULT IN SHOWERS ENDING IN FAR NW PORTIONS
OF THE CWA AROUND MIDNIGHT. THIS TREND WILL CONTINUE FROM
NORTHWEST TO SOUTHEAST THROUGH THE EARLY MORNING HOURS BEFORE THE
LAST OF THE PRECIP EXITS THE LAKESHORE AROUND 15Z THURSDAY. SPED
UP THE EXIT OF PRECIP/CLOUDS A BIT FROM THE PREVIOUS FORECAST DUE
TO MODEL TRENDS...OTHERWISE MADE FEW CHANGES TO WHAT WE HAD GOING
BEFORE. TEMPERATURES WILL BE CHILLY ON THURSDAY AS STRONG COLD AIR
ADVECTION ALOFT SETS UP AND GUSTY NORTH WINDS DEVELOP.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 233 PM CDT WED MAY 22 2013
MAIN FCST CONCERNS INCLUDE FROST/FREEZE POTENTIAL ON THURSDAY NIGHT...
WHETHER OR NOT TO INCLUDE PCPN CHANCES FOR THE HOLIDAY WEEKEND...AND
TEMPERATURES THROUGHOUT THE PERIOD.
HUDSON BAY HIGH PRESSURE WILL RESIDE OVER THE REGION FOR THE END
OF THE WORK WEEK...AND THROUGH THE HOLIDAY WEEKEND. A VERY DRY AIR MASS
WILL BE IN PLACE THURSDAY NIGHT...WITH PRECIPITABLE WATER VALUES
DROPPING TO 0.25 TO 0.33 INCH. CLEAR SKIES AND LIGHT WINDS WILL ALLOW
TEMPERATURES TO PLUMMET TO BLO FREEZING ACROSS MOST OF NC/FAR NE WI...
WITH READINGS POSSIBLY APPROACHING 20 DEGREES IN THE TYPICAL COLD SPOTS.
WILL ISSUE A FREEZE WATCH FOR NC/FAR NE WI...WHERE FREEZING TEMPS ARE
LIKELY. AN SPS WILL BE ISSUED FOR THE REST OF THE CWA...WHERE PATCHY/
AREAS OF FROST ARE A GOOD BET. WILL NEED TO WATCH CENTRAL WI
CLOSELY...AS FCST MIN TEMPS ARE CLOSE TO FREEZING.
THE LARGE HIGH PRESSURE WILL ONLY DRIFT SLIGHTLY TO THE EAST OVER THE
HOLIDAY WEEKEND...WITH THE RIDGE AXIS SETTING UP JUST TO OUR EAST.
THE ECMWF HAS BEEN CONSISTENT IN KEEPING ANY PCPN TO OUR WEST AND SOUTH
THROUGH THE WEEKEND...WHILE THE GFS/GEFS ATTEMPT TO BRING SOME LGT
QPF INTO OUR SW COUNTIES BY ABOUT SUNDAY. HAVE KEPT THE FCST DRY
THROUGH SUNDAY...AND ONLY MENTIONED A SLIGHT CHANCE OF SHOWERS FROM
SUNDAY NIGHT INTO TUESDAY. TEMPERATURES WILL REMAIN A LITTLE BLO
NORMAL THROUGH THE WEEKEND...WITH HIGHS IN THE 60S.
A WARM FRONT IS EXPECTED TO LIFT NORTH INTO THE REGION TUESDAY NIGHT
AND WEDNESDAY...AND MAY BRING A CHANCE OF THUNDERSTORMS AND MILDER
TEMPS TO THE FORECAST AREA.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1130 PM CDT WED MAY 22 2013
A RAPIDLY IMPROVEMENT IN FLIGHT CONDITIONS WILL SWEEP NW-SE ACRS
THE AREA LATE TNGT AND THU MORNING AS THE RAIN-PRODUCING CYCLONE
DEPARTS THE AREA TO THE E AND IS REPLACED BY CANADIAN HIGH
PRESSURE.
.MARINE...
ISSUED AT 233 PM CDT WED MAY 22 2013
HIGH-END SMALL CRAFT ADVISORY ISSUED FOR THIS AFTERNOON THROUGH AT
LEAST FRIDAY FOR GUSTY NORTH TO NORTHEAST WINDS. GUSTS WILL GET
CLOSE TO GALE FORCE TOMORROW LATE MORNING AND EARLY AFTERNOON...
HOWEVER THE BEST MIXING WILL OCCUR AFTER THE STRONGER WINDS OFF
THE SFC BEGIN TO DISSIPATE. SO WILL KEEP THE STRONG WORDED SMALL
CRAFT ADVISORY WITH JUST A MENTION OF A FEW GALE FORCE GUSTS
POSSIBLE. PERSISTENT MARINE FOG HAS BEGUN TO LIFT AND VISIBILITIES
ARE COMING UP THIS AFTERNOON AS WINDS INCREASE. KEPT PATCHY FOG IN
THE FORECAST UNTIL 03Z THURSDAY...BUT AT THIS POINT DEW POINT
DEPRESSIONS AND WINDS INCREASE AND FOG SHOULD NO LONGER BE AN
ISSUE. WILL REMOVE FOG MENTION FROM THE MWW.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY MORNING FOR
WIZ005-010>013-018-019-021.
&&
$$
UPDATE.........ESB
SYNOPSIS.......WOLF
SHORT TERM.....WOLF
LONG TERM......KIECKBUSCH
AVIATION.......JS
MARINE.........WOLF
AREA FORECAST DISCUSSION
NWS GRAY ME
1235 AM EDT SAT MAY 25 2013
.SYNOPSIS...
A COLD FRONT WILL PUSH OFFSHORE AND STALL THIS EVENING. LOW
PRESSURE WILL DEVELOP ON THE FRONT NEAR CAPE COD AND WILL SLOWLY
DRIFT NORTH THROUGH THE GULF OF MAINE SATURDAY AND SATURDAY NIGHT.
LOW PRESSURE WILL ACCELERATE NORTH INTO LABRADOR ON SUNDAY. HIGH
PRESSURE WILL BUILD IN FROM THE WEST SUNDAY NIGHT THROUGH MONDAY.
HIGH PRESSURE WILL SHIFT OFFSHORE ON TUESDAY. A WARM FRONT WILL
APPROACH FROM THE SOUTHWEST TUESDAY NIGHT AND WEDNESDAY AND WILL
PUSH EAST OF THE REGION WEDNESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATE...A QUICK UPDATE TO KEEP FCST UP TO DATE WITH CURRENT OBSERVATIONS.
COLD AIR RUSHING IN ON A NORTHERLY FLOW. PRECIP WILL LIKELY CHANGE
TO A MIX IN THE HIGHER TERRAIN SAT.
PREV UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS...WITH THE COLD
FRONT NOW HAVING SLIPPED SOUTH OF THE COAST WATERS AS OF 0230Z. LOW
PRESSURE WILL CONTINUE TO TAKE SHAPE OFF THE NEW ENG COASTLINE
THEREAFTER...WITH CYCLOGENESIS OCCURRING NEAR CAPE COD THIS
EVENING.
LATEST HRRR MODEL PICKING UP WELL ON CONVECTIVE SEGMENTS CROSSING
THE FORECAST AREA AT THIS TIME. THIS MODEL DEPICTS MORE AREAS OF
RAIN MOVING THROUGH THE REGION LATE TONIGHT AND SATURDAY MORNING.
WILL CONTINUE TO MONITOR COLD AIR RUSHING INTO THE MTNS FROM
CANADA OVERNIGHT. THERE COULD BE SOME MIXED SNOW AND RAIN OVER THE
HIGHER TERRAIN FOR THIS STORM WHICH IS VERY SIMILAR TO THE MAY
26TH 1967 EVENT.
HAVE ADJUSTED WINDS AND TEMPS FOR THE HIGHER TERRAIN. WINDS WILL
BECOME RATHER GUSTY FOR ANY HIKERS OUT OF THE NORTH AND NORTH OVER
THE NEXT COUPLE OF DAYS...WITH SOME SNOW ACROSS THE HIGH TERRAIN.
PREV DISC...
COLD FRONT CURRENTLY MOVING EAST THROUGH EASTERN NEW HAMPSHIRE
AND NORTHWEST MAINE AND THIS BOUNDARY WILL CONTINUE TO PUSH OFF TO
THE EAST THROUGH THE REMAINDER OF THE AFTERNOON. FRONT WILL STALL
OFFSHORE THIS EVENING AND WILL BE THE FOCUS OF LIGHT TO MODERATE
RAINFALL IN MID COAST AND CENTRAL MAINE DURING THE REMAINDER OF
THE AFTERNOON INTO THIS EVENING. WILL SEE A BRIEF BREAK IN THE
ACTION ACROSS NEW HAMPSHIRE DURING THE REST OF THE AFTERNOON
BEFORE NEXT BATCH OF PRECIP EDGES IN FROM THE WEST. WILL TAKE SOME
TIME FOR LOW PRESSURE TO GET SPUN UP OVERNIGHT SO THIS BREAK MAY
TRANSLATE EASTWARD INTO WESTERN MAINE FOR THE EVENING HOURS BEFORE
850 OVER-RUNNING GETS GOING IN EARNEST ACROSS WESTERN MAINE AFTER
MIDNIGHT.
12Z MODELS TRENDING FARTHER WEST WITH AXIS OF HEAVIEST PRECIP AND
COMING INTO LINE WITH LAST NIGHT 00Z ECMWF. 24 HOUR QPF FOR THE
MOUNTAINS AND CONNECTICUT VALLEY DOWN TO AROUND AN INCH TO 1.5
INCHES THROUGH 00Z SUN. WITH THIS IN MIND...DOESN`T APPEAR
FLOODING WILL BE AN ISSUE CONSIDERING THE BREAK IN THE ACTION
THIS AFTERNOON AND LONG DURATION OF THE EVENT ITSELF...SO HOLDING
OFF ON ANY WATCHES AT THIS POINT IN TIME.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM SUNDAY/...
RAIN WILL CONTINUE SATURDAY THROUGH SATURDAY NIGHT AS SURFACE LOW
BECOMES TRAPPED UNDER UPPER LEVEL SYSTEM AND MEANDERS AROUND THE
GULF OF MAINE THROUGH SUNDAY MORNING. MAY SEE SOME WET SNOW OVER
THE HIGHEST TERRAIN AT SOME POINT ON SATURDAY IN FAR WESTERN ZONES BUT
ENOUGH WARM AIR WRAPS AROUND THE SYSTEM THAT THIS WOULD BE FAIRLY
BRIEF. BETTER CHANCE FOR THIS WOULD BE IN THE GREENS OF VERMONT
AND THE DACKS. WILL BE A COLD AND BLUSTERY DAY WITH TEMPS HOLDING
IN THE 40S IN MOST AREAS AND SHOWING LITTLE CHANGE SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
UPR LVL AND SFC LOWS LIFTING NE ON SUNDAY WITH STEADIER PRCP
BECOMING MORE SCT IN NATURE AND LIGHTER IN INTENSITY. ANY LEFTOVER
SHRA ENDING SUNDAY NGT AS THE SYSTEM MOVES INTO THE MARITIMES.
MEMORIAL DAY LOOKS LIKE FAIR WX NOW WITH SYSTEM PULLING OUT FAR
ENOUGH TO THE NE. STILL SOME CYCLONIC FLOW ALOFT AND SOME LEFTOVER
MOISTURE THAT COULD PRODUCE SOME CLOUDINESS ESPECIALLY IN THE N/MT
ZONES DUE TO UPSLOPING NW SFC WINDS. MIGHT SEE AN ISOLD SHRA IN
THE N/MT ZONES OTRW NO PRCP EXPECTED ON MEMORIAL DAY.
HIGH PRES AND UPR LVL RIDGE BUILD IN FOR TUESDAY INTO WEDNESDAY.
THE UPR LVL RIDGE HOLDS 0N OVER THE ERN U.S. BUT A SERIES OF WEAK
UPR LVL SHORT WAVE TROFS DRIVE THRU THE RIDGE FOR LATE WEDNESDAY
AND THURSDAY. THIS FORMS A WRM FRONTAL BOUNDARY TO OUR S THAT
LIFTS N AND WILL PROVIDE SOME CLOUDINESS AND ISOLD TO SCT SHRA
FROM LATE WEDNESDAY THRU THURSDAY. THE UPR LVL RIDGE BECOMES
BETTER ESTABLISHED OVER THE E COAST THURSDAY NGT AND FRIDAY AS THE
SHORT WAVES EXIT THE COAST. THIS SHOULD ALLOW WRM AIR TO CONT
MOVING IN FROM THE SW. STILL CAN`T RULE OUT PSBL SHRA DUE TO WRM
FNT MOVING THRU.
GENERALLY USED BLEND OF GFS40/NAM/MET/MAV/HPC QPF FOR PERIODS 4
AND 5 THEN GFS40, GMOS, HPC QPF, MEX MOS AND WNA4 FOR THE REST OF
THE LONG TERM FCST.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...IFR/LIFR CEILINGS TONIGHT THROUGH SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...MVFR TO PSBL IFR IN SHRA
THAT WILL BE TAPERING OFF SUNDAY INTO SUNDAY NGT. MAINLY VFR
MONDAY THRU TUESDAY AND MOST OF WEDNESDAY.
&&
.MARINE...
SHORT TERM...HAVE EXTENDED SCA TO GO RIGHT THROUGH SATURDAY.
ALTHOUGH WINDS DROP OFF AT SOME POINT...WAVES WILL REMAIN AT LEAST
IN THE 3 TO 5 FOOT RANGE...WITH GREATER SEAS OUT OVER THE OPEN WATERS.
COASTAL FLOOD ADVISORY FOR MINOR SPLASH-OVER AROUND THE TIME OF
HIGH TIDE.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...SCA WIND GUSTS AND SEAS
PSBL SUNDAY THRU MOST OF SUNDAY NGT THEN HIGH PRES DROPS
CONDITIONS BELOW SCA LEVELS MONDAY THRU WEDNESDAY.
&&
.FIRE WEATHER...
NO PROBLEMS NOTED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
ANZ150>154.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
325 AM EDT SAT MAY 25 2013
.SHORT TERM...TODAY AND TONIGHT
EARLY MORNING MSAS ANALYSIS IS SHOWING A SURFACE RIDGE EXTENDING
SOUTHWARD THROUGH THE LAKE SUPERIOR/MICHIGAN/HURON BASINS. THE BEST
SURFACE RIDGING COMPONENT INSIDE OF THE CWA IS ACROSS THE NORTHERN
THUMB DOWN INTO PORT HURON. PERUSING THROUGH THE SURFACE
OBSERVATIONS...FEELING IS THE BEST POTENTIAL FOR ANY FROST FORMATION
WILL BE IN THE THUMB AND LOW LYING AREAS OF THE GLACIAL TERRAIN WITH
THE LOCAL OFFICE TEMPERATURE AT 33 DEGREES AS OF 230 AM LDT. WILL
MAINTAIN THE FROST ADVISORY AS IS FOR SIMPLICITY.
THERE HAS BEEN A DECENT RADAR PRESENTATION OVERNIGHT ACROSS PORTIONS
OF MN/WI/IA TIED TO THE AGEOSTROPHIC RESPONSE OF MERGING AND
SHEARING OF SHORTWAVE ENERGY. ONE HR PRECIPITATION AMOUNTS HAVE BEEN
LESSENING AS THE PRECIPITATION/VIRGA PUSHES FARTHER TO THE SOUTHEAST.
THIS IS LIKELY IN RESPONSE TO INCREASING CONFLUENCE ALOFT AS THE
ENTRANCE REGION LIES DIRECTLY OVER LOWER MICHIGAN. THE BEST UPPER
LEVEL FORCING IN THE FORM OF 700-500MB FRONTOGENESIS WILL BRUSH FAR
SOUTHWESTERN SECTIONS OF THE STATE BETWEEN 12-15Z...BEFORE PASSING
HARMLESSLY TO THE SOUTH. THE AMOUNT OF AMBIENT DRY AIR IN THE LOWEST
12 KFT AGL SUPPORTS VIRTUALLY NO PRECIPITATION POTENTIAL TODAY. THE
PREFERENCE REGARDING HIGH CLOUD PROG LIES WITH THE 25.05Z RUC WHICH
BRINGS HIGH CLOUDS INTO THE SOUTHWESTERN 2/3RDS OF THE CWA BETWEEN
9-16Z THIS MORNING. INCREASED INSOLATION WITH SOME MODERATION OF THE
AIRMASS WILL SUPPORT A SOLID 3-8F DEGREE UPTICK IN HIGH TEMPERATURES.
EXPECT READINGS TO RANGE FROM THE MIDDLE 50S IN THE FAR NORTHERN
THUMB/LAKE HURON SHORELINE TO THE MIDDLE 60S DETROIT SOUTHWARD.
SURFACE HIGH PRESSURE WILL EXPAND ACROSS THE CENTRAL GREAT LAKES
TONIGHT...BRINGING THE PROSPECTS OF ANOTHER COOL TO COLD NIGHT.
DIFFERENTIAL AIRMASS RECOVERY SHOULD BE GOOD FOR A FEW DEGREES OFF
THIS MORNINGS MINS. WORKED WITH A BLEND OF UNDERCUT GUIDANCE WITH
SOME PERSISTENCE. EXPECTED LOWS TONIGHT SHOULD RANGE FROM THE LOWER
TO MIDDLE 30S IN THE THUMB TO LOWER 40S SOUTHEAST OF THE TERRAIN.
&&
.LONG TERM...SUNDAY THROUGH FRIDAY
LOWER MICHIGAN WILL RESIDE BETWEEN A HIGH AMPLITUDE RIDGE ACROSS THE
UPPER MIDWEST AND A DEEP UPPER LOW LIFTING FROM NEW ENGLAND INTO THE
CANADIAN MARITIMES DURING THE LATER HALF OF THE WEEKEND...SUSTAINING
A CONFLUENT FLOW ALOFT. AT THE SFC...THIS WILL TRANSLATE TO HIGH
PRESSURE BUILDING FROM THE UPPER GREAT LAKES ON SUNDAY TO THE
EASTERN GREAT LAKES ON MONDAY. OTHER THAN THE POTENTIAL FOR SOME
HIGH CLOUDS...SKIES SHOULD REMAIN MAINLY CLEAR WITH VERY DRY AIR
OVERHEAD. TEMPS WILL SLOWLY MODERATE...LEADING TO AN OVERALL WARMING
TREND HEADING INTO MEMORIAL DAY. EXPECT MIXING DEPTHS MAY
OVERACHIEVE WITH PLENTY OF SUNSHINE AND SUBSTANTIAL LOW LEVEL DRY
AIR. THIS SUPPORTS LEANING TOWARD THE HIGHER END OF GUIDANCE MAX
TEMPS /MID TO UPPER 60S SUNDAY AND AROUND 70 MONDAY/. THE DRY
AIRMASS AND WEAK SFC GRADIENT WILL SUPPORT OPTIMAL RADIATIONAL
COOLING POTENTIAL...SO MINS SUN NIGHT WILL CONTINUE TO BE QUITE COLD
FOR LATE MAY /UPPER 30S TO MID 40S/.
THE MID LEVEL RIDGE IS FORECAST TO BREAK DOWN EARLY NEXT WEAK AS
NUMEROUS SHORT WAVE IMPULSES ARE EJECTED OUT OF THE LONG WAVE TROUGH
OVER THE WRN US AND ACROSS THE CNTRL/NRN PLAINS. THE BULK OF THE 00Z
MODEL SUITE SUGGEST MCS DEVELOPMENT ACROSS THE UPPER MIDWEST OR WRN
GREAT LAKES MON AFTERNOON/NIGHT AS LOW LEVEL INFLOW STRENGTHENS. THE
POTENTIAL FOR REMNANT MCS ACTIVITY TO ADVANCE INTO SE MI REMAINS
HIGHLY UNCERTAIN AT THIS TIME. WHILE SEVERAL MODEL SOLUTIONS ARE
QUITE BULLISH WITH QPF OVER SE MI MON NIGHT AND TUES...THERE IS
LIKELY SOME SEMBLANCE OF CONVECTIVE FEEDBACK IN THE MODELS. THERE IS
ALSO CONCERN THAT THE MODELS HAVE A POOR HANDLING OF MCS
PROPAGATION...WHICH COULD LEAD TO REMNANT CONVECTION BEING MUCH
FARTHER SOUTH. THUS PLAN TO CARRY VERY LOW CHANCE POPS TUESDAY.
PERSISTENT LOW LEVEL S-SWLY FLOW SHOULD HOWEVER LIFT A WARMER AND
MORE HUMID AIRMASS INTO SRN LOWER MI BY MID WEEK...MARKED BY THE
PASSAGE OF A SFC WARM FRONT. THIS WILL JUSTIFY A CHANCE OF
SHOWERS/THUNDERSTORMS LATE TUES THROUGH WED.
THE ECMWF REMAINS STEADFAST IN DEVELOPING A MORE AMPLIFIED UPPER
TROUGH OVER THE WRN US BY MIDWEEK AS ENERGY EJECTS OUT OF THE GULF
OF ALASKA AND INTO THE WEST COAST. A SEASONALLY STRONG UPPER JET
WITHIN THE BASE OF THE DEEP GULF OF ALASKA UPPER LOW AND CURRENT
AMPLIFIED NATURE OF THE FLOW LENDS SUPPORT TO THE ECMWF. THIS
SOLUTION BUILDS THE SUBTROPICAL RIDGE FARTHER NORTH INTO THE ERN US
LATE IN THE WEEK AND SUGGESTS SE MI MAY BE CAPPED. EVEN THE LESS
AMPLIFIED GFS BUILDS MID LEVEL HEIGHTS SUBSTANTIALLY ACROSS SE MI.
THUS THE FORECAST FOR THE LATER HALF OF NEXT WEEK WILL HAVE VERY LOW
POPS WITH MAX TEMPS WELL INTO THE 80S.
&&
.MARINE...
A STABLE ANTICYCLONE WILL EXPAND ACROSS THE GREAT LAKES THROUGH THE
HOLIDAY WEEKEND. THIS WEATHER FEATURE WILL BE RESPONSIBLE FOR MORE
TYPICAL MARINE CONDITIONS FOR LATE MAY. WAVE HEIGHTS ARE ONLY
EXPECTED TO RANGE IN THE 1 TO 2 FOOT RANGE IN MANY AREAS THROUGHOUT
THE WEEKEND.
&&
.AVIATION...ISSUED 1148 PM EDT FRI MAY 24 2013
//DISCUSSION...
HIGH PRESSURE WILL DOMINATE THE TAF PERIOD WITH NOTHING MORE THAN
MID/HIGH CLOUDS SPREADING ACROSS SOUTHEAST MICHIGAN OVERNIGHT. HIGH
PRESSURE WILL ALSO MAINTAIN A LIGHT NORTHEAST GRADIENT WELL INTO
SATURDAY NIGHT. SCATTERED COVERAGE OF DIURNAL CU AROUND 5-6KFT IS
LIKELY DURING PEAK HEATING ON SATURDAY.
//DTW THRESHOLD THREATS...
* NONE.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY...MIZ047-MIZ048-MIZ049-MIZ053-MIZ054-MIZ055-MIZ060-
MIZ061-MIZ062-MIZ063-MIZ068-MIZ069-MIZ070-MIZ075-MIZ076-MIZ082-
MIZ083...UNTIL 8 AM SATURDAY.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...CB
LONG TERM....SC
MARINE.......CB
AVIATION.....JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
344 AM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CDT SAT MAY 25 2013
INITIAL SHIELD OF WAA SHOWERS THAT WAS DEPICTED WELL ON 310K
ISENTROPIC SFC ON THE NAM/GFS IS FADING AWAY ACROSS WRN WI AS THIS
BATCH OF FORCING WEAKENS AND DIVES SOUTHEAST. IN ITS WAKE...WE HAVE
WAA AT H85...BUT THE DEEPER MOISTURE HAS PUSHED EAST...SO PRECIP HAS
CUT OFF PRETTY QUICK. WITH THE WAA AND WEAK MOISTURE
TRANSPORT...SHOULD BE ABLE TO GET SOME LIGHT SHOWERS/SPRINKLES
ACROSS MN THIS MORNING...BUT NOT MUCH MORE THAN THAT.
BEST CHANCE FOR RAIN TODAY WILL BE ACROSS SRN MN. WARM FRONT NOW CAN
BE FOUND ACROSS SOUTH CENTRAL NEB INTO NE KAN...WITH A STRONG LLJ
OVERRUNNING IT. THIS HAS GENERATED AN MCS OVER ERN NEB THIS MORNING.
THUNDER STARTING TO INCREASE ACROSS IA AS WELL AS THE LLJ HAS SLOWLY
WORKED EAST. MOST OF THIS THUNDERSTORM ACTIVITY WILL REMAIN SOUTH OF
MN THROUGH THE DAY...BUT ALL HI-RES MODELS SHOW SOME OF THIS
MOISTURE FROM IA SNEAKING UP INTO SOUTH CENTRAL MN THROUGH
MORNING...WHERE SOME HIGH CHANCE/LIKELY POPS ARE CONTINUED THROUGH
THE MORNING HOURS. FOR THE AFTERNOON...PRECIP LOOKS TO SHUT
OFF...BUT WE WILL BE STUCK WITH FAIRLY BROAD CLOUD COVER...WITH THE
ONLY HOPE FOR SOME BREAKS ACROSS THE NE MPX CWA THANKS TO THE
INFLUENCE OF A DRY SFC HIGH THAT WILL BE SPLAYED OUT ACROSS THE
GREAT LAKES. GIVEN THE CLOUD COVER WILL BE A COOL DAY...WITH
TEMPERATURES IN SOUTH CENTRAL MN LIKELY STAYING IN THE 50S THANKS TO
BETTER RAIN CHANCES AND THICKER CLOUD COVER.
FOR TONIGHT...ALL MODELS SHOW ANOTHER ROUND OF CONVECTION RIDING
ALONG NORTH OF THE WARM FRONT...KIND OF LIKE WHAT WE HAVE SEEN
OVERNIGHT TO OUR SOUTHWEST. QUESTION BECOMES HOW FAR NORTH DOES THE
ACTIVITY MAKE IT. CONSENSUS PLACEMENT FROM THE WARM FRONT PLACES IT
BY 12Z SUNDAY MORNING FROM THE BLACK HILLS...DOWN THROUGH
YANKTON...SD AND THEN DOWN TO THE CENTRAL IA/MO BORDER. ONCE
AGAIN...WILL SEE A LLJ OVERRUNNING THIS FRONTAL FEATURE...WHICH
SHOULD GENERATE YET ANOTHER MCS. GIVEN THE FRONTS PLACEMENT TO OUR
SOUTHWEST...BEST CHANCES FOR THUNDERSTORMS TONIGHT WILL BE SOUTH OF
THE UPPER MN RIVER IN SW MN INTO SC MN. FOR TIMING...FAVORED HIGHEST
POPS TO AFTER 6Z...AS CONVECTION SHOULD FIRE THIS EVENING OVER SE
SODAK INTO NE NEB...THEN HEAD TOWARD SW/SC MN. ALL OF THIS ACTIVITY
WOULD BE ELEVATED...SO SEVERE THREAT LOOKS MINIMAL...WITH THE MAIN
IMPACT BEING THE POTENTIAL FOR HEAVY RAIN...AS WE HAVE SEEN THIS
EVENING IN NEB.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 344 AM CDT SAT MAY 25 2013
THE LONG TERM PERIOD CONTINUES TO LOOK INCREASINGLY WET AND
STORMY. THIS IS DUE TO THE REGION BEING SANDWICHED BETWEEN A
BUILDING UPPER HIGH ALONG THE EASTERN SEABOARD... WHILE A VERY
DEEP TROUGH PUSHES INTO THE WESTERN HALF OF THE UNITED STATES.
THERE SHOULD BE A ROUND OF CONVECTION PASS ACROSS SOUTHERN MN
SUNDAY MORNING...VERY SIMILAR TO WHAT HAS BEEN ONGOING OVERNIGHT
ACROSS NE/IA. THE STORMS TO OUR SOUTH CURRENTLY HAVE BEEN BASICALLY
SUB SEVERE... BUT VERY EFFICIENT RAIN PRODUCERS... WITH UPWARDS OF
1.75 INCHES OF RAIN IN THREE HOURS. THIS IS THE TREND EXPECTED
SUNDAY MORNING ACROSS SOUTHERN MN... ESPECIALLY THE I-90
CORRIDOR. THEREAFTER... A SIGNIFICANT DIMINISHING TREND IN THE
PRECIPITATION FOR SUNDAY AFTERNOON AND EVENING WITH THE NMM/ARW
WRF/S IN AGREEMENT.
MEMORIAL DAY IS LOOKING A LITTLE WORSE NOW WITH EVEN THE ECMWF
DRIVING A WAVE OF CONVECTION ACROSS THE FA DURING THE DAY AND
EVENING. JUST GENERAL THUNDER INDICATED ON SWODY2 WHICH SEEMS
REASONABLE WITH THE MAIN WARM FRONTAL BOUNDARY MEANDERING FROM THE
CENTRAL PLAINS TO THE LOWER OHIO VALLEY. AGAIN... THE CONCERN WILL
BE LOCALIZED HEAVY RAINFALL. THE DETERMINISTIC RUNS WOULD ALSO
SUGGEST ANOTHER ROUND OF CONVECTION FOR US LATE MONDAY NIGHT AND
TUESDAY MORNING... ESPECIALLY ACROSS SOUTHERN MN.
THIS REPEATING ROUNDS OF POTENTIAL CONVECTION IS DISTURBING WITH
AREAS OF SOUTHERN AND ESPECIALLY SOUTHEAST MN RUNNING WELL ABOVE
NORMAL ON RAINFALL FOR THE MONTH OF MAY. THE THREAT FOR FLASH
FLOODING WILL BE ON THE INCREASE. IT WAS POINTED OUT ON FRIDAY
IN THE WEATHERTALK FROM DR SEELY AT THE UMN THAT SINCE MARCH
1ST...(METEOROLOGICAL SPRING) IT HAS BEEN ONE OF THE WETTEST IN
HISTORY FOR MANY AREAS OF MN. ADD THIS TO THE CIPS ANALOGS
FOR 5 DAYS FROM NOW AND ONE SEES A VERY WET PATTERN ACROSS ALL OF
THE REGION WITH 2 INCHES OF RAINFALL EXCEEDING 30 PERCENT
PROBABILITY WITH EVEN WIDESPREAD 3 INCHES HAVING A 10 PERCENT
PROBABILITY. THIS IS IN ADDITION TO THE RAINS SUNDAY THROUGH
TUESDAY. NOT SURPRISING THEN ARE THE RUN TOTALS FROM THE GFS AND
ECMWF THROUGH NEXT FRIDAY WHICH PAINT THE LANDSCAPE WITH 2 TO 4
INCHES OF RAIN... WITH 4 INCHES OR MORE SOUTH OF US. DIGRESSING
FOR A MOMENT... ONE OF THE MONTHS/YEARS THAT HAS SHOWN UP IN THE
CIPS ANALOGS RECENTLY IS JULY 1993... WITH RECORD FLOODING IN THIS
PART OF THE COUNTRY. A REVIEW FROM NCDC SHOWED LOW PRESSURE ALOFT
OVER THE WESTERN HIGH PLAINS WITH A STRONG SW JET AT 250 MB ACROSS
OUR AREA. THE BERMUDA HIGH HAD PUSHED INTO THE SOUTHEAST UNITED
STATES WITH ORGANIZED 850 MB WINDS FROM THE WESTERN GULF OF MEXICO
TO THE WESTERN GREAT LAKES. HENCE... THE FLOODING POTENTIAL IS A
BIG CONCERN FOR THE WEEK AHEAD AS THE PATTERN IN THE SUMMER OF
1993 MIMICS OUR WEEK AHEAD QUITE WELL.
FINALLY... AND JUST AS IMPORTANT... WILL BE THE THREAT FOR SEVERE
WEATHER NEXT WEEK AS THE WARM FRONT LIFTS NORTH INTO OUR AREA
BEGINNING ON TUESDAY. NOT TOO CONCERN ABOUT SEVERE ON SUNDAY. THE
CHANCE INCREASES SOME ON MONDAY (ISOLATED)...ESPECIALLY IF
AFTERNOON CONVECTION DEVELOPS AS DEEP LAYER SHEAR RISES. THEN FROM
TUESDAY ONWARD THERE IS SEVERE POTENTIAL EACH DAY. THE CIPS
ANALOGS CONTAIN MANY SEVERE REPORTS FOR US FOR THE MIDDLE OF NEXT
WEEK WITH SEVERE PROBABILITIES FROM 15 TO 30 PERCENT FOR THE
ENTIRE FA USING THE TOP 8 ANALOGS. A COLD FRONT MAY MOVE ACROSS
THE FA FROM FRIDAY INTO SATURDAY...DIMINISHING THE SEVERE WEATHER
THREAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1259 AM CDT SAT MAY 25 2013
BATCH OF WARM ADVECTIVE SHOWERS WORKING INTO WI TO START THE
TAF...BUT DRY AIR IS STARTING TO TAKE ITS TOLL...WITH PRECIP
COVERAGE BEGINNING TO DIMINISH. LLJ STARTING TO ORGANIZE INTO ERN
NEB AT THE MOMENT...AND WILL LAY INTO IOWA OVERNIGHT. FOLLOWED
IDEA OF HRRR AND OTHER HI-RES MODELS WITH SHOWERS CURRENTLY OVER
THE MN/WI BORDER SLOWLY DIMINISHING THROUGH 10Z...WITH ANY
SIGNIFICANT TSRA ACTIVITY STAYING SOUTH OF MN THE REST OF THE
NIGHT. HOWEVER...WILL HAVE PLENTY OF CLOUD COVER AND WEAK MOISTURE
TRANSPORT REMAINING INTO THE MORNING...WITH BOUTS OF SPRINKLES/LIGHT
RAIN EXPECTED ACROSS MN...SO DID KEEP SOME VCSH MENTION GOING.
OTHER CHANGE TO THESE TAFS WAS TO START SLOWING DOWN ARRIVAL OF
MVFR CIGS LATER TODAY. BASED TIMING ON THE RAP/HRRR/NAM...WHICH
SHOW MVFR CIGS CURRENTLY DEVELOPING OVER SE NEB NOT ARRIVING INTO
THE RWF AREA UNTIL CLOSE TO 18Z. WITH WARM FRONT EXPECTED TO STAY
DOWN ALONG THE IA/MO BORDER TODAY...EXPECT MAJORITY OF MVFR CIGS
TO STAY DOWN IN IOWA THROUGH THE DAY...WITH A MORE SIGNIFICANT
PUSH OF MVFR CIGS NORTH NOT EXPECTED UNTIL TONIGHT AS THE FRONT
BEGINS A SLOW CRAWL NORTH ACROSS IOWA...BRINGING MVFR CIGS FURTHER
NORTH AS WELL. AS RESULT...DELAYED ARRIVAL OF MVFR CIGS UNTIL
AFTER 00Z FOR ALL MN TERMINALS EXCEPT RWF.
KMSP...GIVEN HOW CIGS WITH RAIN ONLY DROPPED TO 6K FT AT
BEST...FEEL CONFIDENT IN VFR CIGS REMAIN THROUGH THE COURSE OF THE
DAY TODAY. SHOWER COVERAGE WILL BE DIMINISHING THROUGH 8Z...WITH
NOT MUCH MORE THAN SPRINKLES EXPECTED THE REST OF THIS TAF
PERIOD...AS LLJ FORCING REMAINS WELL SOUTH/WEST OF THE FIELD. HAVE
MODERATE CONFIDENCE IN MVFR CIGS DEVELOPING SAT NIGHT...BUT WITH THE
WARM FRONT ONLY MAKING IT INTO CENTRAL IA...MSP MAY REMAIN NE OF THE
MAIN MVFR CIG SHIELD THROUGH THE 30 HRS OF THE TAF.
/OUTLOOK FOR KMSP/
SUN...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10-15 KTS.
MON...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10 KTS.
TUE...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SSE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
327 AM CDT SAT MAY 25 2013
.SHORT TERM...TODAY THROUGH SUNDAY...
AXIS OF WEAK WARM ADVECTION AND FRONTOGENESIS MAXED OUT IN THE
700-600MB LAYER CONTINUES TO TRANSLATE SLOWLY EASTWARD ACROSS
EASTERN MINNESOTA EARLY THIS MORNING WHILE SLOWLY WEAKENING. NW-SE
ORIENTED BAND OF SHOWERS HAS SLOWLY DIMINISHED IN BOTH COVERAGE
AND INTENSITY OVER THE PAST COUPLE OF HOURS..AND SHOULD CONTINUE
TO DO SO THROUGH MID MORNING TODAY. HOWEVER..UNTIL LOW-MID LEVEL
FLOW BACKS AS IT STARTS TO FEEL THE INFLUENCE OF THE NEXT WAVE
MOVING FROM THE ROCKIES INTO THE NRN PLAINS THERE WILL BE AT LEAST
SOME MODEST FORCING FOR ASCENT..AND A FEW SHOWERS COULD PERSIST
INTO LATE MORNING.
BY THIS AFTERNOON..MAIN THREAT FOR ADDITIONAL SHOWERS/TSTORMS IS
EXPECTED TO CONSOLIDATE TO AREAS MOSTLY SOUTH AND WEST OF THE
DULUTH CWA IN CLOSER PROXIMITY TO LOW LEVEL BAROCLINIC ZONE FROM
THE DAKOTAS INTO THE MID MISSOURI VALLEY. AS A RESULT..WE HAVE
CONTINUED THE PREVIOUS TREND OF A DRY FORECAST FOR THIS AFTERNOON
IN MOST AREAS AS EAST/SOUTHEAST LOW LEVEL FLOW BRINGS A FLUX OF
DRIER AIR INTO THE REGION. THE FAR SOUTHWEST CWA WILL REMAIN CLOSE
ENOUGH TO THE LOW LEVEL THERMAL/MOISTURE GRADIENT TO WARRANT AT
LEAST A MENTION OF A FEW SHOWERS TONIGHT. CHANCES FOR SHOWERS THEN
EXPAND A BIT FARTHER EASTWARD ON SUNDAY AS NEXT WAVE BRUSHES
NORTHEASTWARD..ALONG WITH SOME CONTRIBUTION FROM ENHANCED
WARM/MOIST ADVECTION BY THE LLJ LATE SAT NIGHT AND SUNDAY MORNING.
EASTERLY BOUNDARY LAYER FLOW WILL ALSO KEEP AREAS NEAR LAKE
SUPERIOR COOLER TODAY AND SUNDAY..ALONG WITH LOCALLY GUSTY WINDS
IN SOME OF THE FAVORED LOCATIONS NEAR THE TWIN PORTS AND ASHLAND.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY NIGHT...
A PERIOD OF ACTIVE WEATHER WILL DEVELOP THIS WEEK WITH MULTIPLE
DISTURBANCES MOVING ACROSS THE UPPER MIDWEST...PRODUCING RAIN
SHOWERS AND THUNDERSTORMS MONDAY THROUGH SATURDAY. UPPER LEVEL
RIDGE AXIS ACROSS THE REGION LATE THIS WEEKEND WILL SHIFT EWD ON
MONDAY AS A 500MB S/W PUSHES INTO THE RIDGE ACROSS THE NRN PLAINS
ON THE LEADING EDGE OF A LONG WAVE TROUGH OVER THE WRN CONUS. THIS
S/W IS EXPECTED TO HAVE AN ASSOCIATED SFC INVERTED TROUGH/WARM
FRONT LIFT NWD THROUGH CNTRL MN ON MONDAY. RAIN SHOWER CHANCES
WILL INCREASE DURING THE DAY MONDAY...ALONG WITH A SLIGHT CHC OF
T-STORMS. A LLJ WILL DEVELOP MON NIGHT/TUE MORNING AND USHER IN A
MOIST UNSTABLE AIR MASS ACROSS THE REGION. THE INTERACTION OF THIS
S/W AND INCREASED INSTABILITY/MOISTURE WILL ALLOW FOR THE
POTENTIAL OF MDT/HVY RAIN SHOWERS AND EVEN A FEW STRONG STORMS
THROUGH TUE MORNING. THE ACTIVE PATTERN CONTINUES THROUGH THE
MIDDLE AND LATTER PART OF THE WEEK AS THE LONG WAVE TROUGH OVER
THE WEST TRANSITIONS EASTWARD AND CONTINUES TO DRAW UP A ROBUST
AMT OF WARM MOIST AIR FROM THE SOUTH AND PRODUCES RAIN SHOWERS AND
SCATTERED T-STORMS ACROSS THE NORTHLAND INTO THE EARLY PART OF THE
WEEKEND. THERE ARE NOTABLE DIFFERENCES IN THE SYNOPTIC PATTERNS OF
THE ECMWF AND GFS DURING THIS WEEK...WHICH LEAD TO UNRESOLVABLE
CONVECTIVE MODES. AT THIS TIME...WILL CONTINUE WITH HIGH CHC
POPS...LOW LIKELY POPS. IT WILL BE DIFFICULT TO NAIL DOWN SPECIFIC
TIMES/LOCATIONS OF THE BEST/HEAVIEST PRECIP AND ANY T-STORM
CHANCES UNTIL WELL INTO THE WEEK.
TEMPERATURES WILL CONTINUE ON THE WARMING TREND THROUGH THE WEEK
WITH HIGHS ON MONDAY IN THE 60S...AND OVERNIGHT LOWS IN THE 40S. BY
WEDNESDAY...HIGHS WILL BE TOPPING OUT IN THE 70S AND LOWER
80S...WITH NIGHT TIME LOWS IN THE 50S AND 60S.
&&
.AVIATION...06Z TAF ISSUANCE...
VFR CONDITIONS PREVAILED ACROSS THE NORTHLAND LATE THIS EVENING.
AN AREA OF SHOWERS STRETCHED FROM NORTHWEST MINNESOTA INTO
SOUTHEAST MINNESOTA. AN AREA OF MID LEVEL FGEN WAS HELPING TO
DRIVE THESE SHOWERS...AND THIS MOVES EAST THEN DIMINISHES
OVERNIGHT. MVFR CONDITIONS WILL BE POSSIBLE IN THE HEAVIER
SHOWERS...BUT THE OVERALL CHANCE OF THAT IS LOW AND MOST LIKELY
TOWARD KBRD. AN AREA OF MVFR CEILINGS EXISTS OVER PORTIONS OF
CENTRAL NEBRASKA LATE THIS EVENING...AND THE RAP SHOWS THOSE
MOVING QUICKLY NORTH INTO SOUTHWEST MINNESOTA TONIGHT BUT DOES NOT
BRING THEM INTO KBRD ON SATURDAY. WE`LL HAVE TO MONITOR THE
PROGRESSION OF THESE CLOUDS...AS WE WENT VFR FOR PREVAILING
CONDITIONS AT KBRD THROUGH THE PERIOD.
&&
.POINT TEMPS/POPS...
DLH 57 42 60 45 / 20 10 10 10
INL 64 44 68 47 / 10 10 10 20
BRD 61 46 62 50 / 40 20 30 40
HYR 63 42 67 47 / 20 10 10 20
ASX 60 40 61 43 / 10 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM....TENTINGER
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
100 AM CDT SAT MAY 25 2013
.UPDATE...
06Z AVIATION DISCUSSION ADDED BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 355 PM CDT FRI MAY 24 2013
SURFACE CYCLONE AND ASSOCIATED TROUGH NOTED ON IR SATELLITE IMAGERY
FROM SOUTHERN ALBERTA INTO EASTERN WYOMING. WARM FRONT ASSOCIATED
WITH THIS SYSTEM CURRENTLY FIRING UP SHIELD OF MAINLY LIGHT
SHOWERS AND ISOLATED THUNDERSTORMS OVER FAR EASTERN SODAK AND
WESTERN QUARTER OF OUR CWA. USED A COMBO OF HRRR...GFS40 305K
SFC...AND THETA E ADVECTION TO PAINT PICTURE OF FORWARD
PROGRESSION ACROSS REMAINDER OF CWA DURING THE OVERNIGHT. FAIRLY
DRY COLUMN TO CONTEND WITH OVER MUCH OF THE FA THIS AFTERNOON AND
EVENING...THUS AM EXPECTING MAINLY LIGHT PCPN FOR THIS FIRST WAVE
OF ACTIVITY. ALTHOUGH K INDICES AND 850 LI`S INDICATING LITTLE
CHANCE OF THUNDER ATTM...DECIDED TO INCLUDE ISOLATED CHANCE MOST
AREAS INTO TOMORROW AFTN DUE TO FAIR AMOUNT OF LIGHTNING NOTED ON
CURRENT 0.5 REFLECTIVITY. AS PREVIOUSLY ADVERTISED CHANCES FOR
WIDESPREAD CONVECTIVE ACTIVITY DECREASE MARKEDLY AFTER ABOUT
25/15Z TIME FRAME...AS WARM FRONTAL BOUNDARY STALLS OVER NE
MINNESOTA BY LATE SATURDAY MORNING. DECIDED TO INCREASE SATURDAY`S
HIGHS BY ONE CATEGORY CONSIDERING LIMITED PCPN POTENTIAL AND
POSSIBILITY OF MUCH LESS CLOUD COVER THEN CURRENTLY FORECAST.
FOCUS FOR ANY CONVECTIVE ACTIVITY ON SATURDAY AFTERNOON DEFINITELY
NOTED OVER FAR SOUTHERN MINNESOTA...WITH BEST UPPER LEVEL SUPPORT
VIA 250MB WEAK TO MODERATE DIVERGENCE OVER THIS REGION. LEFT SLGT
POPS OVER REMAINDER OF CWA TOMORROW AFTN DUE TO FAIRLY ROBUST
850-500MB LAPSE RATES.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 355 PM CDT FRI MAY 24 2013
THETA E ADVECTION BLOSSOMS FROM SOUTHWEST INTO CENTRAL MN ON
SATURDAY NIGHT INTO SUNDAY...WHEN BOTH GFS AND NAM MODELS FORECAST A
SHORTWAVE TO CARVE THROUGH THE MID LEVEL RIDGE. EXPECT TO SEE
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING...WITH THE HIGHEST
COVERAGE OVER SOUTHWEST MN WHERE 850 MB MOISTURE TRANSPORT IS
SLIGHTLY ENHANCED. HIGH TEMPERATURES ON SUNDAY WILL LIKELY MAX
OUT IN THE UPPER 50S AND LOWER 60S...AS THE WARM FRONT REMAINS TO
THE SOUTH OF THE AREA AND EXTENSIVE CLOUD COVER AND SHOWERS
PERSIST.
YET MORE WEAK SHORTWAVES RIDE NORTH OF THE WARM FRONT ON MEMORIAL
DAY...AND CONTINUE THE POSSIBILITY OF SCATTERED SHOWERS AND
THUNDERSTORMS. SHOULD SEE TEMPS MODERATE SLIGHTLY FOR THE
HOLIDAY...ALTHOUGH IT WILL STILL BE ON THE COOL SIDE WITH UPPER
60S TO MID 70S.
ON TUESDAY...THE AFOREMENTIONED WARM FRONT WILL BEGIN TO LIFT
NORTH...AND ENTER THE FORECAST AREA FROM WEDNESDAY THROUGH
THURSDAY. THIS WILL SIGNAL THE ARRIVAL OF SLIGHTLY WARMER
TEMPERATURES AND AN INCREASE IN HUMIDITY...WITH HIGHS IN THE 75 TO
80 DEGREE RANGE. THE ARRIVAL OF THE FRONT WILL ALSO YIELD AN
INCREASING THREAT FOR SEVERE WEATHER AND EXCESSIVE RAINFALL FOR
THURSDAY AND FRIDAY. FORECAST PRECIPITABLE WATER VALUES INCREASE TO
OVER 1.5 INCHES...WHICH ILLUSTRATES THE POTENTIAL FOR A DOUSING
RAINFALL EVENT. THE SEVERE WEATHER POTENTIAL IS SOMEWHAT UNCERTAIN
DUE TO THE DIFFERENCES IN THE MODELS WITH THE EVOLUTION OF THE
WESTERN TROUGH...AND THE DEGREE OF SURFACE CYCLOGENESIS THAT
ENSUES OVER THE NORTHERN PLAINS TOWARD THE END OF NEXT WEEK.
HOWEVER...IF THE 24.12Z GFS SHEAR AND INSTABILITY PROGS WERE TO
PAN OUT...THERE WOULD BE A FAIRLY HIGH THREAT FOR SEVERE WEATHER
AND TORNADOES ACROSS CENTRAL AND SOUTHERN MN ON THURSDAY
AFTERNOON/EVE. WILL CONTINUE TO MONITOR AND REFINE OVER THE NEXT
FEW MODEL RUNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1259 AM CDT SAT MAY 25 2013
BATCH OF WARM ADVECTIVE SHOWERS WORKING INTO WI TO START THE
TAF...BUT DRY AIR IS STARTING TO TAKE ITS TOLL...WITH PRECIP
COVERAGE BEGINNING TO DIMINISH. LLJ STARTING TO ORGANIZE INTO ERN
NEB AT THE MOMENT...AND WILL LAY INTO IOWA OVERNIGHT. FOLLOWED
IDEA OF HRRR AND OTHER HI-RES MODELS WITH SHOWERS CURRENTLY OVER
THE MN/WI BORDER SLOWLY DIMINISHING THROUGH 10Z...WITH ANY
SIGNIFICANT TSRA ACTIVITY STAYING SOUTH OF MN THE REST OF THE
NIGHT. HOWEVER...WILL HAVE PLENTY OF CLOUD COVER AND WEAK MOISTURE
TRANSPORT REMAINING INTO THE MORNING...WITH BOUTS OF SPRINKLES/LIGHT
RAIN EXPECTED ACROSS MN...SO DID KEEP SOME VCSH MENTION GOING.
OTHER CHANGE TO THESE TAFS WAS TO START SLOWING DOWN ARRIVAL OF
MVFR CIGS LATER TODAY. BASED TIMING ON THE RAP/HRRR/NAM...WHICH
SHOW MVFR CIGS CURRENTLY DEVELOPING OVER SE NEB NOT ARRIVING INTO
THE RWF AREA UNTIL CLOSE TO 18Z. WITH WARM FRONT EXPECTED TO STAY
DOWN ALONG THE IA/MO BORDER TODAY...EXPECT MAJORITY OF MVFR CIGS
TO STAY DOWN IN IOWA THROUGH THE DAY...WITH A MORE SIGNIFICANT
PUSH OF MVFR CIGS NORTH NOT EXPECTED UNTIL TONIGHT AS THE FRONT
BEGINS A SLOW CRAWL NORTH ACROSS IOWA...BRINGING MVFR CIGS FURTHER
NORTH AS WELL. AS RESULT...DELAYED ARRIVAL OF MVFR CIGS UNTIL
AFTER 00Z FOR ALL MN TERMINALS EXCEPT RWF.
KMSP...GIVEN HOW CIGS WITH RAIN ONLY DROPPED TO 6K FT AT
BEST...FEEL CONFIDENT IN VFR CIGS REMAIN THROUGH THE COURSE OF THE
DAY TODAY. SHOWER COVERAGE WILL BE DIMINISHING THROUGH 8Z...WITH
NOT MUCH MORE THAN SPRINKLES EXPECTED THE REST OF THIS TAF
PERIOD...AS LLJ FORCING REMAINS WELL SOUTH/WEST OF THE FIELD. HAVE
MODERATE CONFIDENCE IN MVFR CIGS DEVELOPING SAT NIGHT...BUT WITH THE
WARM FRONT ONLY MAKING IT INTO CENTRAL IA...MSP MAY REMAIN NE OF THE
MAIN MVFR CIG SHIELD THROUGH THE 30 HRS OF THE TAF.
/OUTLOOK FOR KMSP/
SUN...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10-15 KTS.
MON...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10 KTS.
TUE...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SSE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...AJZ
LONG TERM...LS
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1237 AM CDT SAT MAY 25 2013
.AVIATION...06Z TAFS
VFR CONDITIONS PREVAILED ACROSS THE NORTHLAND LATE THIS EVENING. AN
AREA OF SHOWERS STRETCHED FROM NORTHWEST MINNESOTA INTO SOUTHEAST
MINNESOTA. AN AREA OF MID LEVEL FGEN WAS HELPING TO DRIVE THESE
SHOWERS...AND THIS MOVES EAST THEN DIMINISHES OVERNIGHT. MVFR
CONDITIONS WILL BE POSSIBLE IN THE HEAVIER SHOWERS...BUT THE OVERALL
CHANCE OF THAT IS LOW AND MOST LIKELY TOWARD KBRD. AN AREA OF MVFR
CEILINGS EXISTS OVER PORTIONS OF CENTRAL NEBRASKA LATE THIS
EVENING...AND THE RAP SHOWS THOSE MOVING QUICKLY NORTH INTO
SOUTHWEST MINNESOTA TONIGHT BUT DOES NOT BRING THEM INTO KBRD ON
SATURDAY. WE`LL HAVE TO MONITOR THE PROGRESSION OF THESE CLOUDS...AS
WE WENT VFR FOR PREVAILING CONDITIONS AT KBRD THROUGH THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 646 PM CDT FRI MAY 24 2013/
UPDATE...
AREA RADARS SHOW AN AREA OF RAIN...WITH A FEW THUNDERSTORMS...FROM
FAR NORTHWEST MINNESOTA INTO SOUTH CENTRAL MINNESOTA AS OF EARLY
EVENING. THIS IS TIED CLOSELY WITH AN AREA OF 700MB FGEN. THE FGEN
WILL MOVE A BIT TO THE EAST TONIGHT...THEN DIMINISH BY 12Z. WE
WILL UPDATE IN A BIT TO ADJUST POPS AND WE`LL USE THE 700MB FGEN
AS A GUIDE TO WHERE TO PUT THE HIGHER POPS.
AVIATION...00Z TAFS
VFR CONDITIONS COVERED THE NORTHLAND AS OF EARLY EVENING...BUT AN
AREA OF SHOWERS WERE MOVING EAST TOWARD KBRD/KXVG. WE EXPECT THIS
AREA OF SHOWERS...AND POSSIBLY SOME THUNDERSTORMS...TO MOVE EAST
THIS EVENING. IT SHOULD NOT OVERTAKE ALL AREAS AS DRIER AIR
EXISTS OVER THE EAST...AND THE FORCING RESPONSIBLE DOES NOT MOVE
THROUGH THE NORTHLAND EITHER. KBRD WILL HAVE THE BEST CHANCE AT
SEEING RAIN TONIGHT. MVFR CONDITIONS WILL DEVELOP OVER PORTIONS OF
THE WEST...WITH CEILINGS LOWERING OVER OTHER LOCATIONS THROUGH THE
PERIOD.
PREV DISCUSSION... /ISSUED 405 PM CDT FRI MAY 24 2013/
SHORT TERM...TONIGHT AND SATURDAY...
AN AREA OF SHOWERS AND THUNDERSTORMS FROM THE EASTERN DAKOTAS AND
WESTERN MN WILL SLOWLY SPREAD EAST THIS EVENING. THIS AREA IS AN
AREA OF LOW LEVEL WARM AIR ADVECTION AND AN ASSOCIATED UPPER LEVEL
VORT MAX ROUNDING OUT THE TOP OF UPPER RIDGE. MOST OF THE LIFT
ASSOCIATE WITH THE SYSTEMS WILL SLIDE ACROSS THE SOUTHWEST SECTIONS
OF THE CWA...WHERE THERE ARE THE HIGHER POPS. PUT SOME POPS IN
FARTHER NORTH ALONG THE HIGHWAY 2 CORRIDOR IN MN AND NORTHWEST
WI...BUT WITH DEW POINTS IN THE 20S...IT WILL TAKE AWHILE TO
MOISTEN UP FOR RAIN.
THE SHORT TERM MODELS...LOCAL AND THE SREF...ARE CONSISTENT IN
SHOWING THE BAND OF SHOWERS OUT TO THE WEST WITH MORE SPOTTY
SHOWERS OVER THE EAST LATE TONIGHT AND TOMORROW MORNING. BY
AFTERNOON THE MAJOR AREA OF PRECIPITATION WILL MOSTLY BE ACROSS
WESTERN AND SOUTHERN MINNESOTA...LEAVING MOST OF THE NORTHLAND
UNDER CLOUDY SKIES.
LONG TERM [SATURDAY NIGHT - THURSDAY]...
HIGH PRESSURE OVER EASTERN CANADA AND THE EASTERN UNITED STATES WILL
HELP TO SUPPRESS RAIN CHANCES ACROSS THE NORTHLAND SATURDAY NIGHT
AND SUNDAY. THE NORTHLAND WILL BE HEADING INTO A POTENTIALLY
WARM...WET...AND ACTIVE PERIOD NEXT WEEK. A MID/UPPER LEVEL RIDGE
OVER THE CENTRAL UNITED STATES WILL BEGIN TO SHIFT EAST AS A
MID/UPPER LEVEL TROUGH MOVES INTO THE WEST. THE MODELS INDICATE ONE
OR MORE WARM FRONTS MAY MOVE THROUGH OR NEAR THE NORTHLAND DURING
THE MID TO LATE WEEK PERIOD...WHICH COULD BE A STORMY PERIOD FOR THE
NORTHLAND.
&&
.POINT TEMPS/POPS...
DLH 57 41 61 43 / 20 0 10 10
INL 62 43 67 45 / 20 10 0 10
BRD 58 46 63 50 / 50 10 30 30
HYR 61 41 67 47 / 30 0 10 20
ASX 60 39 63 44 / 20 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS HASTINGS NE
428 AM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM CDT SAT MAY 25 2013
FOCUS REMAINS ON TSTM POTENTIAL.
TSTMS CONTINUE EARLY THIS MORNING WITH MCS ROLLING EAST ACROSS
CENTRAL/EASTERN NEBRASKA. MAIN IMPACT CURRENTLY FM CONVECTION IS HEAVY
RAINFALL...WITH MANY LOCATIONS NORTH OF INTERSTATE 80 PICKING UP
AT LEAST AN INCH OF RAIN. WE HAVE HAD ONE REPORT OF 3.13 INCHES SO
FAR AT LOUP CITY WITH RAIN STILL FALLING.
THIS INITIAL ROUND OF CONVECTION WILL CONTINUE TO MOVE EAST/END THIS
MORNING THEN ATTENTION TURNS TO ADDITIONAL CHANCES FOR CONVECTION
THIS AFTN. SFC BOUNDARY HAS SETTLED NEAR THE NEB/KS STATELINE AND
FRONT IS PROGGED TO LIFT NORTHWARD THIS AFTN INTO SC NEB...WITH SFC
LOW ORIENTED IN EASTERN COLORADO AND DRY LINE ALONG THE HIGH PLAINS
REGION. FRONTAL BOUNDARY AND ANY RESIDUAL OUTFLOW BOUNDARIES WILL BE
FOCUS FOR CONVECTION AGAIN THIS AFTN/EVE AND BOUNDARY PLACEMENT
WILL NEED TO BE MONITORED CLOSELY. CAP LOOKS TO HOLD INITIALLY
HOWEVER MODELS ARE INDICATING DEVELOPMENT ALONG THE DRY LINE AND
ALONG/NORTH OF WARM FRONTAL BOUNDARY...AND HAVE FOLLOWED CLOSER TO
RAP MODEL FOR POTENTIAL DEVELOPMENT THIS AFTN. STORMS FOR
TODAY/TONIGHT HAVE THE POTENTIAL TO BE MORE VOLATILE WITH SEVERE
PARAMETERS INDICATING POTENTIAL FOR SUPERCELLS. INSTABILITY IS
PROGGED AROUND 4000 J/KG WITH SHEAR OF 40KTS OR SO AND STORMS WILL
BE CAPABLE OF PRODUCING VERY LARGE HAIL...DAMAGING WINDS AND EVEN
TORNADOES IN VCNTY OF BOUNDARIES. HEAVY RAINFALL/FLOODING ALSO
REMAINS A CONCERN DUE TO THE HEAVY OVERNIGHT/EARLY THIS MORNING
AND PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH TO INCH
AND A HALF AND ARE A 100 TO 150 PERCENT OF NORMAL. ALL OF THIS
BEING SAID...MODELS ARE NOT CONSISTENT IN FRONTAL POSITION WHICH
IS KEY TO DEVELOPMENT THIS AFTN. AGAIN FEEL RAP AND LATEST SREF
RUN HAS A BETTER HANDLE ON THE FARTHER SOUTH WARM FRONTAL POSITION
ACROSS OUR AREA TODAY...AND WILL NEED TO MONITOR CLOSELY.
OTHERWISE...LOOK FOR SOME WARMER TEMPS THIS AFTN AND STEADY/GUSTY
WINDS WITH THE HIGHEST WIND SPEEDS EXPECTED ACROSS NC KANSAS/SOUTH
OF WARM FRONT...WHERE WINDY CONDITIONS ARE POSSIBLE WITH GUSTS OF
30+ MPH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 423 AM CDT SAT MAY 25 2013
SUNDAY THROUGH FRIDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS MOST EVERY DAY AND TEMPERATURES THROUGH
THE PERIOD.
A VERY ACTIVE WEATHER PATTERN WILL AFFECT THE FORECAST AREA THROUGH
THE PERIOD. AN UPPER LEVEL LOW DEVELOPS IN THE WESTERN CONUS AND
GRADUALLY MOVES THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS BY FRIDAY. THIS UPPER LOW WILL SEND WAVES INTO THE FORECAST
AREA THROUGH THE PERIOD. THE MODELS ARE SIMILAR IN THE MAIN
FEATURES...BUT THE ECMWF HAS A LITTLE STRONGER AMPLITUDE MID WEEK.
EACH OF THE WAVES WILL HAVE A CHANCE FOR SOME THUNDERSTORMS WHEN
THEY MOVE THROUGH. IT CERTAINLY WILL NOT BE A RAIN OUT...IT WILL NOT
RAIN ALL OF THE TIME...BUT THERE WILL BE CHANCES FOR SOME SHOWERS
AND THUNDERSTORMS AT VARIOUS TIMES DURING THE PERIOD.
THE BEST CHANCES FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND
SUNDAY NIGHT...DURING WHICH TIME THE CAPE APPROACHES 5000 J/KG.
ANOTHER GOOD CHANCE WILL BE MONDAY AFTERNOON AND MONDAY NIGHT WITH
CAPES OVER 5000 J/KG AGAIN. BEYOND MONDAY THE MODELS HAVE A FEW
TIMING DIFFERENCES WITH THE UPPER LEVEL WAVES THAT MOVE THROUGH THE
AREA AND THEREFORE TIMING THUNDERSTORMS IS MORE OF A CHALLENGE.
TEMPERATURES WILL BE THE WARMEST SUNDAY THROUGH TUESDAY THEN SLOWLY
COOL OFF TOWARD THE END OF THE WEEK. TEMPERATURES SHOULD STILL
REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 1217 AM CDT SAT MAY 25 2013
TSTMS WILL IMPACT THE TERMINAL INTO THE OVERNIGHT HOURS...WITH
POTENTIAL FOR SEVERE WEATHER WITH DAMAGING WINDS...LARGE HAIL AND
HEAVY RAINFALL. CHCS FOR TSTMS AND SEVERE WEATHER RETURN SATURDAY
EVENING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...JCB
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
109 AM EDT SAT MAY 25 2013
.SYNOPSIS...
CHILLY HIGH PRESSURE TAKES CHARGE TONIGHT INTO SATURDAY. WARM
FRONT LIFT NORTH INTO THE OHIO VALLEY AND WEST VIRGINIA EARLY
TUESDAY. A WARMING TREND EXPECTED MEMORIAL DAY THROUGH NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
9 PM UPDATE. STILL GOING WITH A FROST SCENARIO FOR THE LOW LANDS
UNDER A FROST ADVISORY. DEWPOINTS ACROSS THE NORTH ARE NOW IN THE
LOW TO MID 30S ON A DECREASING NORTH WIND. WHILE THE MAJOR CITIES
MAY ESCAPE FROST...THE OUTLYING AREAS AND FAVORED LOW SPOTS ARE
INCREASINGLY LIKELY FOR SOME FROST. WILL MAKE NO CHANGE TO HEADLINES
NOR CURRENT FORECAST.
PREVIOUS DISCUSSION...
VERY TOUGH FCST TONIGHT REGARDING FROST/FREEZE POTENTIAL. DWPTS
CURRENTLY STRADDLING THE MARGINAL THRESHOLD FOR FROST TONIGHT
GIVEN AFTN MIXING. NOT SURE IF THESE GO LWR NEXT FEW HRS BEFORE
RECOVERING THIS EVE. GUIDANCE FOR METRO AREAS IN THE LOWLANDS RUN
32 TO 40F FROM KHTS TO KCRW. H925 WINDS STAY UP ARND 20 KTS
OVERNIGHT AS SFC HIGH BUILDS IN TO ALLOW WINDS AT THE GROUND TO
TRY TO GO CALM. ALL OF THIS COMPLICATES MATTERS FOR EXPANDING
FROST ADV. HOWEVER...GIVEN TIME OF YEAR AND FACT THAT MOST FOLKS
HAVE SOME OF THEIR VEGGIES IN THE GROUND ALONG WITH ANNUAL PLANT
INVESTMENTS...FELT PRUDENT TO LEAN A LITTLE LIBERAL AND EXPAND TO
ENCOMPASS REST OF CWA SAVE FOR S COAL FIELDS TO SW VA. OUTLYING
AREAS WILL SEE BEST SHOT OF FROST. HEADLINE SHOULD GARNER MORE
ATTENTION FOR FOLKS TO TAKE PRECAUTIONS TO BE ON SAFE SIDE. ALSO
EXPANDED FRZ WARNING TO RALEIGH BASED ON GUIDANCE RANGING FROM 28F
TO 33F. THEY WILL HAVE GET UNDER INVERSION THOUGH GIVEN H925 WINDS
OFF MDLS OVERNIGHT. OTHER CONCERN IS STRATUS OVERNIGHT ACROSS THE
N. NAM HAS BEEN WAY TOO FAST IN ERADICATING THE LLVL MOISTURE VS
RUC WHICH HAS BEEN PRETTY STEADY. RUC SHOWS CLDS LIFTING AND SCT
THIS EVE ACROSS THE N BEFORE REDEVELOPING IN N MTNS BY 06Z. NAM
KEEPS ENTIRE COLUMN DRY BUT HAS NOT HANDLED TDY WELL AT ALL. SO
WILL LEAN TOWARD RUC AND REDEVELOP SOME STRATUS IN N MTNS LATE
TONIGHT. THIS MAY KEEP TEMPS UP TONIGHT ESPECIALLY IN
VALLEYS...BUT STILL FEEL AOB FRZ TEMPS WILL BE REALIZED.
UPR TROF AXIS SHIFTS TO E COAST ON SAT WITH SOME RECOVERY IN TEMPS
COMPARED TO TDY. INHERITED TEMPS LOOKED GOOD AND ONLY NEEDED
TWEAKING SOME...MAINLY ACROSS THE N.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
MADE MODIFICATIONS TO THE SHORT TERM FORECAST AS FOLLOWS:
HIGH PRESSURE WILL BE IN CONTROL THROUGH THE WEEKEND...KEEPING DRY
CONDITIONS AREAWIDE. MODELS SHOW A MID LEVEL SHORTWAVE...EVIDENT
IN H5 CHARTS...UNDER NORTHWEST FLOW ALOFT...MOVING ACROSS SOUTHERN
OH...SOUTHEAST INTO NORTHWEST KY. REMOVED ANY POPS FOR THE WEEKEND
AS MOISTURE LOOKS VERY LIMITED OVER WV. IN FACT...THERE COULD BE
SOME CLEARING SATURDAY NIGHT INTO SUNDAY MORNING...KEEPING
TEMPERATURES AT OR JUST BELOW FREEZING OVER POCAHONTAS AND
RANDOLPH COUNTIES. INCLUDED PATCHY FROST OVER NORTHEAST MOUNTAINS.
HIGH PRESSURE MOVES EAST OVER THE MID ATLANTIC STATES KEEPING
INFLUENCE OVER WV FOR A DRY SUNDAY THROUGH MONDAY NIGHT.
MINOR CHANGES TO TEMPERATURES THROUGH THE PERIOD...PERHAPS A
COUPLE DEGREES LOWER CLOSER TO THE COOLER MET.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ANOTHER SHORTWAVE UNDER NORTHWEST FLOW ALOFT PASSES ACROSS
SOUTHEAST OH AND WV MONDAY AND TUESDAY. AT THE SAME TIME...A WARM
FRONT LIFTS NORTH INTO SOUTHERN OH...ACROSS WV AND VA ORIENTED
WEST TO EAST BY 12Z TUESDAY. THESE TWO FEATURES WILL BE CAPABLE TO
PRODUCE SHOWERS AND STORMS LATE MONDAY INTO TUESDAY AS THE WARM
FRONT MOVES NORTH OF THE AREA BY EARLY WEDNESDAY. INCREASED POPS
TO CHANCE INCLUDING THUNDER IN WEATHER GRIDS ACCORDINGLY.
HIGH PRESSURE TAKES CONTROL BY EARLY WEDNESDAY PROVIDING DRY
WEATHER WITH A SLOW WARMING TREND THROUGH THE REST OF THE WEEK.
TWEAKED COUPLE OF DEGREES DOWN FROM HPC GUIDANCE IN THE EXTENDED
PERIODS.
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED ACROSS THE FORECAST AREA THROUGH THE TAF
PERIOD. ONE EXCEPTION IS SOME MVFR CEILINGS CURRENTLY IN
EKN...AND COULD ALSO GET SOME MVFR VISIBILITY THERE BEFORE THE SUN
COMES UP. EKN SHOULD RETURN TO VFR BY 13Z-14Z. VFR CU FIELD WILL
DEVELOP TODAY...GENERALLY 6-9KFT. UPPER LEVEL DISTURBANCE BRINGS
CLOUDS TO THE SOUTH TONIGHT...BUT AGAIN REMAINING VFR.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: TIMING AND DENSITY OF FOG AT EKN MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SAT 05/25/13
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EDT 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY M M M M M M M M M M M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H M M M H H H H H H H
AFTER 06Z SUNDAY...
NO WIDESPREAD IFR EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR WVZ005>011-
013>020-026>032-039-040.
FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR WVZ035>038-046-
047.
OH...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR OHZ066-067-075-
076-083>087.
KY...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR KYZ101>103-105.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30
NEAR TERM...JMV/30
SHORT TERM...ARJ
LONG TERM...ARJ
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
431 AM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT SAT MAY 25 2013
THUNDERSTORM COMPLEX OVER NEBRASKA OVERNIGHT CONTINUES EARLY THIS
MORNING. SEEING SHOWERS AND STORMS BEGINNING TO EXPAND ACROSS
NORTHWEST IOWA AS WELL AS LOW LEVEL THETAE ADVECTION INCREASES. HIGH
RES MODEL SUITE LOOK TO HAVE A PRETTY GOOD HANDLE ON THIS ACTIVITY.
EXPECT IT TO CONTINUE THIS MORNING AND POSSIBLY EXPAND A BIT FURTHER
NORTH INTO PORTIONS OF SOUTHWEST MINNESOTA. LOWERED POPS ACROSS
SOUTHEAST SOUTH DAKOTA...AS ALL INDICATIONS ARE THAT THESE STORMS
WILL NOT DEVELOP NORTHWEST OF THEIR CURRENT LOCATION. MOST OF THE
STORMS SHOULD BE EAST OF THE CWA BY 16Z. MAIN IMPACTS WILL BE
BRIEFLY HEAVY RAIN AND POSSIBLY SMALL HAIL WITH THESE CELLS...AS
EFFECTIVE SHEAR AND CAPE ARE TOO LOW FOR ANY SEVERE THREAT. MUCH OF
THE AFTERNOON SHOULD THEN BE DRY ACROSS THE CWA WITH AN AREA OF
SUBSIDENCE LIKELY BEHIND THIS MORNINGS SHORTWAVE. WARM FRONTAL
BOUNDARY WILL POSITION ITSELF SOUTH OF THE MISSOURI RIVER THIS
AFTERNOON. HRRR AND RAP TRY TO BREAK THE CAP THEIR THIS
AFTERNOON...BUT BOTH THESE MODELS SEEM A BIT OVERDONE WITH DEWPOINTS
AND INSTABILITY. FEEL MORE LIKELY SCENARIO IS ACTIVITY WAITS FOR THE
LOW LEVEL JET TO KICK IN AFTER 0Z BEFORE IT GETS GOING.
OTHER ISSUE TODAY IS CLOUD COVER AND HIGH TEMPERATURES.
INTERESTINGLY THE HRRR AND RAP ARE COMPLETE OPPOSITE OF EACH
OTHER...GIVING AROUND A 20 DEGREE DIFFERENCE IN HIGHS...WITH THE RAP
HAVING MORE STRATUS AND COOLER TEMPERATURES. THE GEM AND ECMWF SIDE
CLOSER TO THE RAP...WITH THE NAM IN BETWEEN. SINCE THE AREAL
COVERAGE OF LOW STRATUS IS CURRENTLY LESS THAN EXPECTED...DID GO
AHEAD AND RAISE HIGHS SEVERAL DEGREES FOR TODAY IN OUR CENTRAL AND
WEST. ALSO THE HRRR HAS A GOOD HANDLE ON THE CURRENT SITUATION...SO
ONE WOULD THINK ITS SHORT RANGE FORECAST SHOULD BE SOMEWHAT
RELIABLE...AND IT HAS CONSISTENTLY BEEN WARM FOR TODAY. LOWERED
HIGHS A FEW IN THE EAST WHERE IT IS RAINING...AND WHERE STRATUS
SHOULD INDEED HOLD IN FOR MUCH OF THE DAY. AGAIN THIS IS A PRETTY
LOW CONFIDENCE TEMPERATURE FORECAST FOR ANYWHERE EAST OF THE JAMES
RIVER. BUT FEEL GOING FORECAST IS A DECENT STARTING POINT...WITH THE
DAY SHIFT LIKELY HAVING TO ADJUST UP OR DOWN DEPENDING ON CLOUD
COVER TRENDS.
QUIET SHORT TERM CONDITIONS FROM THE AFTERNOON HOURS SHOULD TURN
QUICKLY TO MORE STORMY CONDITIONS OVERNIGHT. GAVE A FAIR AMOUNT
OF CREDIT TO THE CONSISTENCY OF THE 00Z HIGH RESOLUTION NAMDNG5
AND WRF-ARW SOLUTIONS...WHICH FIT THE OVERALL CONCEPTUAL MODEL FOR
CONVECTIVE INITIATION TONIGHT. BOUNDARY FROM CURRENT NIGHT MCS
WILL BE FESTERING AND DRIFTING NORTHWARD...WITH LIKELY 1000 TO
1500 J/KG ELEVATED CAPE LIFTED FROM 1 TO 1.5 KM AGL. AS 35 TO 40
KNOT LOW LEVEL JET DEVELOPS TONIGHT THROUGH THE CENTRAL PLAINS...
SHOULD BECOME ENOUGH TO INITIATE ELEVATED THUNDERSTORMS NEAR/NORTH
OF THE BOUNDARY WHICH WILL BE DRIFTING NORTHWARD OF INTERSTATE 80
DURING THE EVENING HOURS. EFFECTIVE SHEAR IN AREAS NORTH OF THE
BOUNDARY WILL BE VERY CONCENTRATED IN THE 1-3KM LAYER WITH STRONGEST
WINDS IN LOW LEVELS AND WEAKENING MID LEVEL WINDS ROUGHLY 20-30
KNOTS...WITH LESSER DEEP LAYER SHEAR CONTRIBUTIONS FROM ABOVE. ALL
SUGGEST AT LEAST A MINIMAL THREAT FOR ISOLATED LARGER HAIL OR
DAMAGING WINDS THROUGH THE MISSOURI RIVER CORRIDOR AND LIFTING
SOMEWHAT NORTHWARD THROUGH 066-08Z. OTHER SIGNIFICANT CONVECTIVE
INITIATION IS LIKELY TO OCCUR BACK THROUGH THE WESTERN HIGH PLAINS
WHERE STRONGER SHEAR EXISTS WITH A BIT STRONGER MID LEVEL WINDS
TO AROUND 25 KNOTS...AS WELL AS THE DEEP UPSLOPE TRANSPORT OF MOISTURE
TO RESULT IN STRONGER INSTABILITY. EVENTUALLY...WHEN SUPERCELL MOTIONS
WHICH WILL TAKE ACTION MORE SOUTHWARD THAN EAST START TO EASE...AND
LOW LEVEL JET VEERS EASTWARD...WILL FIND A MORE LINEAR MCS LIKELY
TAKING SHAPE. MANY HI RES MODELS SUGGEST THIS MCS WILL ZIPPER DOWN
THE LOCATION OF THE WARM ADVECTION WING SPREADING NORTHWARD...MOVING
TOWARD EAST CENTRAL SD AND SOUTHWEST MN LATE NIGHT. SEVERE THREAT
WITH THIS FEATURE WOULD SEEM TO BE SOMEWHAT LOWER...BUT LIKELY TO
GET SOME GUSTY WINDS AND AREAS OF HEAVY RAINFALL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 430 AM CDT SAT MAY 25 2013
MCS EXPECTED TO WEAKEN AND SHIFT EAST ON SUNDAY...AND WITH MID
LEVEL FORCING SHOWING TENDENCY TO FORCE SUBSIDENCE AROUND
MIDDAY...AGAIN EXPECT THAT MUCH OF THE DAYTIME PERIOD WILL
PROBABLY END UP PRECIPITATION FREE. HOWEVER...CLOUDS LIKELY TO
PERSIST WITH STRATUS DEVELOPING IN WAKE OF SYSTEM. MOST LIKELY TO
GET BREAKS THROUGH THE WESTERN AND SOUTHERN CWA DURING THE
AFTERNOON...AND HAVE PUSHED EXPECTED TEMPS TO NEAR 80 THERE...
WHILE MORE MID TO UPPER 60S LINGER IN THE FAR EAST. RESULT OF THIS
WILL BE GENERATION OF DECENT POTENTIAL INSTABILITY OF 1500-2000
J/KG ACROSS THE AREA...WITH WEAKEST OF THE CAPPING INVERSION NEAR
THE MISSOURI RIVER CORRIDOR. SHEAR BECOMES A BIT MORE DISTRIBUTED
THROUGH THE EFFECTIVE LAYER...AND FAIRLY CLOSE TO THOSE VALUES
FROM THIS EVENING FROM 30 TO 35 KNOTS. A FEW MORE SEVERE STORMS
WOULD BE POSSIBLE MAINLY THROUGH THE SOUTHWEST HALF OF THE AREA
DURING THE LATER AFTERNOON AND EVENING HOURS...AS INITIATION
LIKELY TO BE A RESULT OF WEAK IMPULSE SLIDING UP BACK SIDE OF
RIDGE IN THE LATER AFTERNOON AND EARLY EVENING.
THE FURTHER ONE GOES INTO THE FORECAST...THE LESS RELIABLE ANY
GUIDANCE BECOMES GIVEN THE ABUNDANCE OF CONVECTION...AND THE
INCREASINGLY GREAT UNCERTAINTY AS TO WHERE CRITICAL BOUNDARIES MAY
LIE. ONE THING FOR SURE...GIVEN THE CLOSED LOW ACROSS THE WESTERN
U.S. AND THE SOUTHWEST FLOW ALOFT...DIFFICULT TO PINPOINT ANY TIME
FROM MONDAY ON THAT ONE COULD SAY THERE WAS ABSOLUTELY NO CHANCE
FOR PRECIPITATION...BUT ON THE SAME FRONT IT CERTAINLY WILL NOT BE
AN ALL TIME WASHOUT WITH MANY BREAKS DEFINED ON THE MESOSCALE.
MEMORIAL DAY AND MONDAY NIGHT WILL PLACE THE AREA ON THE SOUTHERN
FLANK OF A COUPLE OF WAVES MOVING OVER THE RIDGE...SO LIKELY TO
HAVE ENHANCEMENT OF PRECIPITATION IN THE NOCTURNALLY FAVORED
PERIODS. WHILE A FEW SEVERE STORMS ARE AGAIN WELL WITHIN
REASON...HIGH PRECIPITABLE WATER AND FAIRLY SLOW MOVING WIND
PROFILES BRING THE CONCERN OF AREAS OF HEAVY RAINFALL...AT THIS
RANGE HARD TO DEFINE. AT THE MOMENT...THE PROSPECT FOR MORE
SIGNIFICANT CONVECTION AND SEVERE WEATHER WOULD APPEAR TO BE LATE
DAY WEDNESDAY INTO THURSDAY...AS DEEP WESTERN CLOSED LOW KICKS
STRONGER JET ENERGY INTO THE PLAINS. MOISTURE THROUGH LOWER LEVELS
/THUS INSTABILITY/ WILL CONTINUE TO BENEFIT FROM PERSISTENT
SOUTHERLY FLOW. TEMPERATURES WILL LIKELY GRAVITATE TO SOMEWHAT
ABOVE NORMAL READINGS THROUGH THE UPCOMING WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1103 PM CDT FRI MAY 24 2013
MODELS CONTINUE TO SHOW CEILINGS DETERIORATING INTO MVFR-IFR RANGE
LATER TONIGHT AT ALL TAF SITES. STARTING TO SEE HINTS OF MVFR CLOUDS
IN EASTERN NEBRASKA AS OF 04Z...SO WILL CONTINUE THIS DOWNWARD TREND
IN CEILINGS THROUGH THE FIRST 4-6 HOURS OF TAF PERIOD...WITH NEXT
CHANCE OF RAIN EXPANDING INTO SOUTHERN PARTS OF THE AREA ALONG WITH
THE LOWER CEILINGS. SOME MID LEVEL INSTABILITY PRESENT AS THE RAIN
MOVES INTO SOUTHWEST PARTS OF THE FORECAST AREA...BUT PRECIP MOVES
INTO MORE STABLE AIRMASS AS IT PROGRESSES EASTWARD...LEADING TO MORE
ISOLATED THUNDER THREAT ALONG AND EAST OF I-29 CORRIDOR. THUS HAVE
LEFT MENTION OF THUNDER OUT OF KFSD/KSUX TAFS AT THIS TIME...THOUGH
CANNOT COMPLETELY BE RULED OUT 08Z-15Z...ESPECIALLY AT KSUX. BULK OF
MVFR CEILINGS EXPECTED TO BECOME MORE SCATTERED THROUGH THE LATE
MORNING/EARLY AFTERNOON SATURDAY...THOUGH WITH MORE ABUNDANT LOW
LEVEL MOISTURE...POTENTIAL FOR MVFR CUMULUS AT TIMES THROUGH THE
AFTERNOON. GREATER CHANCE OF MVFR-IFR REDEVELOPMENT SATURDAY EVENING
WITH NEXT CHANCE OF CONVECTION SPREADING INTO THE AREA.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN/CHENARD
LONG TERM...CHAPMAN
AVIATION...
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
347 AM CDT SAT MAY 25 2013
.DISCUSSION...
RADAR/SATELLITE LOOP INDICATES THAT THE WEAK MID LEVEL LOW IS
LIKELY LOCATED NEAR ABILENE AND 00Z 500MB ANALYSIS CONFIRMS IT IS
WARM-CORE IN NATURE. AS IS OFTEN THE CASE WITH WARM-CORE
LOWS...CONVECTION IS FIRING BEFORE SUNRISE ACROSS THE HILL
COUNTRY WITHIN A WEAK LOW LEVEL JET AXIS WHERE THETA-E ADVECTION
AND OROGRAPHIC LIFT ARE OCCURRING. SHORT-TERM MODELS SUCH AS THE
HRRR AND RUC SUGGEST THAT SCATTERED CONVECTION WILL CONTINUE TO
EXPAND NORTHWARD FROM CENTRAL TEXAS INTO THE WESTERN ZONES DURING
THE MORNING HOURS. THE GFS APPEARS TO BE SUFFERING FROM GRID SCALE
CONVECTIVE FEEDBACK WHICH IS RESULTING IN VERY HIGH QPF AND
CONTAMINATED MASS FIELDS...THUS THE GFS WILL NOT BE USED IN THE
SHORT-TERM. THE NAM SEEMS TO BE MATCHING CURRENT TRENDS AND SHORT-
TERM MODELS WELL AND THEREFORE IT GIVES CONFIDENCE TO RAISE POPS
TODAY. WE EXPECT THE BEST COVERAGE OF CONVECTION IN THE WESTERN
ZONES THIS MORNING. SCATTERED CONVECTION WILL BUILD/EXPAND
EASTWARD INTO THE EASTERN ZONES DURING THE MIDDAY/AFTERNOON HOURS.
THE AIRMASS OVER THE EASTERN ZONES WILL BE A BIT MORE UNSTABLE DUE
TO BETTER INSOLATION AND A COUPLE OF STRONG STORMS WITH GUSTY
WINDS WILL BE POSSIBLE...BUT DUE TO WEAK SHEAR THE SEVERE THREAT
IS LOW. HIGHS TODAY IN THE WESTERN ZONES WILL ONLY BE IN THE UPPER
70S TO LOW 80S DUE TO CLOUDS/RAIN...WITH HIGHS IN THE EASTERN
ZONES REACHING THE MID 80S. SCATTERED CONVECTION WILL CONTINUE
INTO THE EVENING HOURS BEFORE DISSIPATING WITH LOSS OF HEATING.
THE WARM CORE MID LEVEL LOW WILL BE EXITING THE REGION TO THE
NORTHEAST TONIGHT...AND THEREFORE THE RAIN CHANCES WILL COME TO AN
END. EXPECT A DRY SUNDAY WITH TEMPERATURES REBOUNDING INTO THE
MID-UPPER 80S AREA WIDE. AS AN UPPER LEVEL TROUGH DEVELOPS ACROSS
THE INTER-MOUNTAIN WEST...A SURFACE LOW WILL DEEPEN IN THE HIGH
PLAINS MONDAY. THIS WILL BRING BREEZY SOUTH WINDS TO THE REGION
MONDAY WHICH WILL LIKELY PERSIST THROUGH THE WEEK. LOW TEMPS WILL
WARM INTO THE 70S AREA WIDE BY MIDWEEK WITH HIGHS GENERALLY IN THE
MID 80S EAST TO LOW 90S WEST. THE SOUTHWEST FLOW ABOVE THE
SURFACE WILL BRING A THERMAL INVERSION INTO THE AREA. THUS THE
FORECAST LOOKS DRY UNLESS/UNTIL FORCING ARRIVES TO WEAKEN THE CAP.
MODEL GUIDANCE REMAINS IN POOR TO FAIR AGREEMENT REGARDING THE
EVOLUTION/EJECTION OF THE WEST COAST UPPER TROUGH MID-LATE WEEK.
THE ECMWF CONTINUES TO SHOW A VERY NEGATIVELY TILTED TROUGH
SWINGING THROUGH THE REGION LATE WEDNESDAY AND THURSDAY WHICH
WOULD BODE WELL FOR RAIN. BUT IT CONTINUES TO BE THE ONLY MODEL
THAT SHOWS THE TROUGH EJECTION LIKE THIS...AND FRANKLY THE 500MB
PATTERN IT PRESENTS JUST DOES NOT LOOK REALISTIC. IF IT WERE NOT
FOR THE ECMWF BEING THE BETTER OF THE LONG RANGE MODELS...I WOULD
DISCOUNT IT ALTOGETHER AND SHOW A DRY FORECAST ON THURSDAY...BUT
FOR NOW HAVE RETAINED THE SLIGHT CHANCE POPS. THE GFS/UKMET/GEM
FORECASTS SHOW THAT THE UPPER ENERGY NEEDED TO BREAK THE CAP WILL
LIKELY REMAIN WELL NORTHWEST OF THE REGION. FURTHERMORE...THE
DRYLINE ALSO LOOKS LIKE IT WILL REMAIN TOO FAR TO THE WEST...WITH
THE GFS SHOWING IT AS FAR WEST AS THE TX PANHANDLE. STORM MOTIONS
WILL GENERALLY BE NORTHEAST AND THIS MEANS STORMS WOULD NOT EVEN
HAVE A CHANCE TO PROPAGATE INTO THE CWA EITHER. SO IN SUMMARY THE
RAIN CHANCES ON THURSDAY AT THIS POINT ARE HINGING ON THE ECMWF
BEING CORRECT...AND THIS MAY BE A BIT OF A LONG SHOT.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 84 69 87 69 87 / 40 30 10 5 0
WACO, TX 83 68 87 68 89 / 50 30 10 5 0
PARIS, TX 83 67 85 66 85 / 30 30 10 5 0
DENTON, TX 85 67 86 68 87 / 40 30 10 5 0
MCKINNEY, TX 84 67 85 68 87 / 30 30 10 5 0
DALLAS, TX 85 71 87 70 89 / 30 30 10 5 0
TERRELL, TX 84 67 86 68 88 / 30 30 10 5 0
CORSICANA, TX 84 67 88 68 89 / 30 30 10 5 0
TEMPLE, TX 82 67 87 68 88 / 50 20 10 5 0
MINERAL WELLS, TX 81 66 87 67 89 / 40 20 10 5 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
246 AM PDT Sat May 25 2013
.SYNOPSIS...
Memorial Day Weekend is expected to be a little cooler than
average, and a series of weak upper level disturbances will bring
the potential for scattered showers Sunday and Monday. The moist,
showery weather pattern is expected to linger into late next week.
&&
.DISCUSSION...
Today through Sunday...General trof pattern continues to influence
the sensible weather over Eastern Washington and Northern Idaho
keeping it unsettled at times along with temperatures on the cool
side of what would be considered normal this time of year. Last
few HRRR model runs hit at surface based convection over the
northern mountains after 11AM PDT today and upon further inspection
GFS runs for this interval show the cold pool aloft at 500mb
helping to keep the instability overhead extends west to overhang
parts of the cascades...thus the minor mention of afternoon and
early evening thunderstorms has been stretched westward to cover
parts of the East Slopes of the Northern cascades roughly north of
Leavenworth. Models also hint at a mesoscale shortwave or two
producing enough forcing to allow for some minor mention of
showers overnight...one near the cascades and the other passing
over the Blue Mountains up into North Idaho Panhandle. Sunday the
trof overhead is very very cluttered with synoptic and mesoscale
shortwave propagation through it which allows for the mention of
showers to persist. Forecast temps show a very slight cooling
trend as the flow turns a bit more southerly, which is a warm
trajectory most of the time, for Sunday. Additionally since the
jet stream is south of the forecast area through this time
interval resulting in a lowered tropopause (down to near 400mb)
some of these showers could produce the typical early spring
precipitation type (graupel or soft hail) for a spell along with
mixing moderate wind gusts down to the surface which is something
to keep in mind over the weekend. /Pelatti
Sunday Night through Wednesday: The cool upper level trough that
has been anchored over the Pacific Northwest since Wednesday is
expected to pivot into western Montana Sunday night into Monday
bringing scattered showers to the eastern third of Washington and
northern Idaho. Despite the displacement of this upper low, our
weather pattern isn`t expected to change much. There is good
agreement between the medium range models that the Polar Jet will
dive into southern Oregon and carve another upper level trough
over the Pacific Northwest. The best jet dynamics (Q-Vector
Divergence) Monday night into Tuesday should be over southern
Oregon into the Great Basin, but there will be enough moisture and
deep layer instability with the weakening frontal occlusion to
maintain a good chance of showers Tuesday and Tuesday night.
Depending on the timing of this system, we may need to add a
mention of thunderstorms on Tuesday. The 00z GFS, Canadian and
ECMWF are in pretty good agreement with a weak, negatively tilted
trough over central and western Washington. The GFS and ECMWF
are producing precipitation that looks convectively driven over
the north Cascades. The potential for thunderstorms over the burn
scars around Wenatchee, Ellensburg, and Chelan will be a concern
through the summer and we will continue to monitor patterns like
this one closely for mudslides and debris flows.
The axis of a west to east oriented upper trough is expected to
linger over the Pacific Northwest Wednesday and through the end of
the week. It does look like Tuesday`s frontal occlusion will bring
the most widespread shower activity to the region this week, but
afternoon and early evening showers will be in the forecast for
much of the week. /GKoch
Wednesday Night through Friday Night: Through this time frame we
continue to see an unsettled pattern that will continue to feature
the chance for precipitation across most of the Inland NW
especially for the higher terrains of the ID Panhandle along with
Cascade Crests earlier in the period. Models are in pretty good
agreement through Friday Afternoon by keeping a large scale
negatively tilted trough pattern in place allowing for moisture to
flow in behind the low center that pushes to our SE throughout the
night on Wednesday. With the increased moisture, there will be
thick cloud cover keeping temps in the lower 60s and 70s for
most correlating to below normal temps for this time of year. Low
temps will follow the same pattern of a couple degrees below
normal due to the lack of daytime heating. Towards the end of the
period models are indicating a ridge builds behind the exiting
trough which should help to diminish the precipitation
threat...lower the cloud coverage and ultimately push temperatures
closer to seasonal averages as we approach next weekend. Overall
not many changes were made to the forecast..just tinkered with the
POPs slightly to reflect most recent model data and trended the
temps in the same manner. /Fliehman
&&
.AVIATION...
06Z TAFS: The Inland Northwest will be under a broad area of low
pressure through tonight. Mid to high level cloud cover is expected
over much of the region through Saturday morning. Some low level
moisture across the northern valleys and Panhandle valleys tonight
may result in some patchy fog by the morning hours. Another
relatively weak system for Saturday afternoon will produce mainly
mountain showers. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 44 65 46 65 47 / 20 10 30 50 30 10
Coeur d`Alene 63 42 65 45 64 44 / 20 20 30 50 40 10
Pullman 64 43 63 44 65 46 / 10 10 30 50 20 20
Lewiston 71 48 70 50 71 51 / 10 10 30 50 20 20
Colville 67 41 72 45 69 44 / 40 30 20 20 50 20
Sandpoint 63 39 66 43 63 42 / 30 20 20 40 50 20
Kellogg 61 44 63 46 62 47 / 40 20 30 60 50 20
Moses Lake 72 46 73 49 73 50 / 10 10 30 20 10 20
Wenatchee 68 47 70 49 71 51 / 10 10 30 10 10 20
Omak 68 41 71 45 70 46 / 30 20 30 10 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1148 PM CDT FRI MAY 24 2013
.UPDATE...
ISSUED AT 646 PM CDT FRI MAY 24 2013
QUICK UPDATE TO REFLECT THE FASTER TIMING OF PRECIPITATION
CURRENTLY ACROSS WESTERN/CENTRAL MINNESOTA. THIS ACTIVITY IS
RIDING ALONG MID LEVEL FRONTOGENESIS AND WARM AIR
ADVECTION...AND COMBINED WITH SOME DECENT UPPER LEVEL FORCING / PV
ADVECTION. MOST OF THE MESO-MODELS AND 18Z GUIDANCE SHOWS THIS
SLIDING SOUTH/EAST MAINLY ALONG AND WEST OF THE MISSISSIPPI RIVER
THROUGH THE OVERNIGHT. SO HAVE SPED UP PRECIPITATION WORDING TO
ACCOUNT FOR THIS. OTHERWISE...FORECAST REMAINS ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 334 PM CDT FRI MAY 24 2013
AT 3 PM...A 1003 MB HIGH PRESSURE SYSTEM...CENTERED OVER LAKE
MICHIGAN...KEPT SKIES PARTLY SUNNY ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY. MEANWHILE FURTHER WEST...A SHORT WAVE WAS PRODUCING
SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN QUARTER OF THE
DAKOTAS AND WESTERN MINNESOTA. THE MESO AND DETERMINISTIC MODELS ARE
CONTINUING TO STRUGGLE WITH THE EASTWARD PROGRESS OF THIS
PRECIPITATION TONIGHT. THE ECMWF AND HRRR MOVE THIS PRECIPITATION
ACROSS MOST OF FORECAST AREA BY 25.06Z. MEANWHILE THE
NMM...ARW...GFS...GEM...RAP... AND NAM MAINLY CONFINE THE
PRECIPITATION WEST OF THE MISSISSIPPI RIVER THIS EVENING...AND
THEN MOVES IT ACROSS THE REMAINDER OF THE AREA OVERNIGHT. SINCE
THE CONVECTION ACROSS THE DAKOTAS WILL BE MOVING INTO AN AREA WITH
LESS FRONTOGENETIC FORCING...MOISTURE TRANSPORT...WEAK ISENTROPIC
LIFT...AND DRIER AIR...DECIDED TO TREND THE FORECAST TOWARD THE
LATTER MODEL SET. IN ADDITION...THE RADAR ECHOS ACROSS WESTERN
MINNESOTA ARE SHOWING A DECREASING TREND. EVEN BY DOING
THIS...THERE IS SOME VARIATIONS AMONGST THEM...SO TRIED TO GO WITH
AN ENSEMBLE APPROACH WHEN ASSIGNING THE HOURLY PRECIPITATION
CHANCES. THE HIGHEST PRECIPITATION CHANCE AND AMOUNTS /UP TO A
HALF INCH/ WILL BE FOUND ACROSS ACROSS SOUTHEAST MINNESOTA AND
NORTHEAST IOWA.
ON SATURDAY...THE SHORT WAVE WILL MOVE EAST SOUTHEAST ACROSS IOWA.
AS THIS OCCURS...THE 850 MB MOISTURE TRANSPORT AND ISENTROPIC LIFT
WILL GRADUALLY WEAKEN. AS A RESULT...WENT WITH A DECREASING TREND
IN THE PRECIPITATION TRENDS FROM LATE MORNING INTO THE AFTERNOON.
ADDITIONAL RAINFALL AMOUNTS WILL BE LESS THAN 2 TENTHS OF AN INCH.
WITH THE 24.12Z AND 24.18Z MODELS IN GOOD AGREEMENT THAT THERE
WILL BE LESS THAN 100 J/KG CAPES...JUST KEPT AN ISOLATED
THUNDERSTORM CHANCE MAINLY WEST AND SOUTH IF THE INTERSTATE 94
CORRIDOR.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 PM CDT FRI MAY 24 2013
FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT...THE WARM FRONT WILL
REMAIN WELL SOUTHWEST OF THE FORECAST AREA. AS A RESULT...
SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST WISCONSIN
WILL REMAIN CLOUDY WITH PERIODIC SHOWERS AND MAYBE AN ISOLATED
THUNDERSTORM. OVER THE PAST 3 DAYS...THE CONSALL HAS CONTINUED
TO TREND TOWARD COOLER HIGH TEMPERATURES FOR SUNDAY. IT NOW HAS
HIGH TEMPERATURES AROUND 60. MEANWHILE THE ECMWF ONLY HAS HIGH
TEMPERATURES IN THE LOWER 50S FOR THESE AREAS. SINCE THE ECMWF
TYPICALLY VERIFIES THE BEST FOR THIS TIME PERIOD...WENT WITH A
BLEND OF THE CONSALL...CONSALLBC...AND ECMWF.
FROM MEMORIAL DAY INTO TUESDAY...THE MODELS ARE CONTINUING TO SHOW
THAT A WARM FRONT WILL MOVE NORTHWARD INTO THE AREA. THIS WILL
ALLOW ML CAPES TO CLIMB INTO THE 1K TO 3K J/KG RANGE. AS A
RESULT...EXPECT THE THUNDERSTORM CHANCES TO INCREASE DURING THIS
TIME PERIOD. THE 0-3KM SHEAR WOULD BE FAVORABLE FOR THE
POSSIBILITY THAT A FEW THUNDERSTORMS MAY BE CAPABLE OF PRODUCING
LARGE HAIL AND DAMAGING WINDS.
FROM TUESDAY NIGHT INTO FRIDAY...THE MODELS CONTINUE TO STRUGGLE
ON WHERE THE WARM SECTOR WILL BE LOCATED. THIS GREATLY AFFECTS
THE WHERE THE PRECIPITATION MAY BE LOCATED. IN ADDITION...IT WILL
ALSO AFFECT THE SHEAR AND INSTABILITY...THUS...THERE IS A LOT OF
UNCERTAINTY ON WHETHER THERE WILL BE ANY SEVERE WEATHER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1148 PM CDT FRI MAY 24 2013
A BAND OF LIGHT TO MODERATE RAIN HAS SET UP ALONG AND JUST TO THE
WEST OF THE MISSISSIPPI RIVER AND IS EXPECTED TO PERSIST THROUGH
THE OVERNIGHT HOURS. AS THE FORCING WEAKENS LATER THIS
MORNING...EXPECT THAT THE RAIN WILL COME TO AN END THOUGH SOME
MVFR CEILINGS WILL BECOME POSSIBLE AT RST. CURRENT THINKING IS
THAT CONDITIONS SHOULD MAINLY BE DRY THROUGH THE REST OF THE DAY
WITH OVERALL FORCING BEING WEAK INTO THE NIGHT. THE MAIN QUESTION
WILL BE WHETHER THERE WILL BE ENOUGH LOW LEVEL MOISTURE TRAPPED
UNDER THE SHALLOW INVERSION AROUND 3KFT TO PRODUCE SOME MVFR
CEILINGS...PARTICULARLY AT RST. WITH CONFIDENCE NOT AS HIGH AS IT
PREVIOUSLY WAS...HAVE REMOVED IT FROM THE FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...ZT
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1011 AM CDT SAT MAY 25 2013
.DISCUSSION...
ISSUED 1011 AM CDT SAT MAY 25 2013
OVERNIGHT MCS FROM IOWA HAS BEEN SHOWING SOME WARMING CLOUD TOPS
AS IT DROPS SOUTHEAST INTO WESTERN ILLINOIS. HAVE BEEN SEEING SOME
LIGHT ECHOES ON RADAR AS FAR EAST AS THE INDIANA BORDER...BUT THE
AIR MASS OVER CENTRAL ILLINOIS IS VERY DRY AS EVIDENCED BY THE
MORNING SOUNDING AND LAPS ANALYSIS...SO A LOT OF THIS HAS BEEN
ALOFT. FINALLY SEEING SOME MEASURABLE RAIN AROUND GALESBURG
THOUGH. RAP AND HRRR MODELS DOING A REASONABLE JOB WITH THE MCS
ITSELF...AND SHOW THE RAIN MOST WIDESPREAD THROUGH EARLY AFTERNOON
BEFORE BREAKING UP. MOST OF THE THUNDERSTORMS HAVE BEEN DROPPING
SOUTHEASTWARD TOWARD WEST CENTRAL ILLINOIS...SO HAVE CUT BACK SOME
ON THE THUNDER CHANCES...ESPECIALLY NORTH OF I-74. HAVE SENT OUT
SOME UPDATES TO SIGNIFICANTLY INCREASE THE RAIN CHANCES ACROSS THE
NORTHWEST HALF OF THE CWA...WITH LESSER CHANGES NEEDED ACROSS THE
SOUTHEAST.
GEELHART
&&
.AVIATION...
ISSUED 657 AM CDT SAT MAY 25 2013...FOR THE 12Z TAFS
SHOWERS ARE ADVANCING INTO THE DRY AIR MASS ACROSS CENTRAL IL FROM
THE W-NW. RADAR IMAGES ARE A LITTLE MISLEADING WITH MOST OF THE
RETURNS BELOW 40 DBZ ASSOCIATED WITH VIRGA AT THIS POINT. THE
AIRMASS WILL EVENTUALLY SUCCUMB TO THE ISENTROPIC LIFT...MOISTURE
CONVERGENCE AND STRENGTHENING LOW LEVEL JET...AS HEAVIER RAINS AND
A FEW THUNDERSTORMS BECOME MORE PROMINENT THIS AFTERNOON AND
TONIGHT. MOST AREAS SHOULD REMAIN VFR WITH CLOUD HEIGHTS ABOVE 3K
FT. VIS MAY DIP TO MVFR 3-5SM DURING HEAVIER SHOWERS AND
STORMS...BUT ANY PERIODS OF IFR CONDITIONS DURING STORMS WILL BE
BRIEF.
FREQUENT RAINS AND ISOLATED THUNDERSTORMS WILL CONTINUE TONIGHT
DESPITE LOSING LOW LEVEL INSTABILITY. A SATURATED AIRMASS AND WEAK
INSTABILITY ABOVE AN ELEVATED MIXED LAYER WITH PROVIDE ENOUGH
SUPPORT FOR SOME STORMS AND PERSISTENT RAIN.
WINDS WILL START OUT EASTERLY...THEN VEER TO THE SOUTHEAST AND
INCREASE INTO THE 10-14KT RANGE AS THE NEXT MESO-VORTEX ARRIVES
FROM THE WEST LATER THIS MORNING AND AFTERNOON. WINDS MAY BACK TO
THE EAST AGAIN THIS EVENING AS WARM FRONTOGENESIS INCREASES
ACROSS CENTRAL IL FROM WEST TO EAST.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 242 AM CDT SAT MAY 25 2013
UNSETTLED WEATHER THROUGH THE MEMORIAL DAY WEEKEND...FOLLOWED BY
MUCH WARMER/DRIER CONDITIONS FOR THE MIDDLE AND END OF NEXT WEEK.
SHORT TERM...TODAY THROUGH MONDAY
CONVECTION CURRENTLY DEVELOPING ALONG THE NOSE OF A 45-50KT LLJ
OVER NEBRASKA IS EXPECTED TO TRACK E/SE INTO THE AREA TODAY. MAIN
QUESTION WILL BE HOW FAR EAST THE PRECIP CAN PENETRATE INTO
SPRAWLING SURFACE RIDGE AXIS EXTENDING FROM THE GREAT LAKES TO THE
GULF COAST. 00Z KILX UPPER AIR SOUNDING SHOWED A VERY DRY PROFILE
FROM THE SURFACE UP TO ABOUT 500MB. ANY PRECIP MOVING INTO THIS
HOSTILE ENVIRONMENT WILL INITIALLY EVAPORATE UNTIL THE AIRMASS IS
SUFFICIENTLY MOISTENED. DUE TO THE CONTINUED DRY E/NE LOW-LEVEL
FLOW...HAVE REMOVED POPS ACROSS EAST-CENTRAL AND SOUTHEAST
ILLINOIS FOR THE MORNING HOURS. FURTHER WEST...HIGH-RES HRRR
SUGGESTS NEBRASKA CONVECTION WILL EVENTUALLY SPREAD INTO
WEST-CENTRAL ILLINOIS TOWARD MIDDAY. WILL THEREFORE CARRY CHANCE
POPS DURING THE MORNING...THEN LIKELY THIS AFTERNOON FOR LOCATIONS
ALONG/WEST OF I-55.
INITIAL AREA OF CONVECTION WILL DISSIPATE AS IT MOVES INTO
EAST-CENTRAL ILLINOIS LATER THIS AFTERNOON AND EVENING.
MEANWHILE...LOW-LEVEL JET WILL ONCE AGAIN STRENGTHEN AND FOCUS A
RENEWED ROUND OF SHOWERS/THUNDER UPSTREAM ACROSS IOWA TONIGHT.
THIS ACTIVITY IS THEN EXPECTED TO TRACK E/SE INTO CENTRAL ILLINOIS
LATE TONIGHT INTO SUNDAY. WITH AIRMASS MOISTENED FROM INITIAL
PRECIP TODAY...THINK RAIN CHANCES WILL BE HIGHER ACROSS THE BOARD
TONIGHT/SUNDAY. WILL THEREFORE CARRY LIKELY POPS EVERYWHERE EXCEPT
THE FAR SE CWA.
ADDITIONAL SHOWERS/STORMS WILL FIRE ON MONDAY...AS PERSISTENT
FRONTAL BOUNDARY FINALLY BEGINS TO SHIFT SLOWLY NORTHWARD ACROSS
THE AREA. WILL CONTINUE TO HIT POPS HARD...ESPECIALLY ACROSS THE
CENTRAL AND NORTHERN ZONES. TOTAL RAINFALL FROM THIS MULTI-DAY
EVENT WILL BE LIGHTEST ALONG THE ILLINOIS/INDIANA BORDER WHERE
AMOUNTS OF ONE HALF TO ONE INCH WILL BE COMMON. HIGHER RAIN TOTALS
WILL BE FOCUSED FURTHER WEST...ESPECIALLY WEST OF I-55 WHERE ONE
AND A HALF TO TWO INCHES WILL BE LIKELY.
LONG TERM...TUESDAY THROUGH FRIDAY
AS UPPER TROUGH DIGS OVER THE WESTERN CONUS...DOWNSTREAM RIDGE
WILL BUILD ACROSS THE MIDWEST/OHIO RIVER VALLEY. THIS WILL FINALLY
GIVE THE SURFACE FRONT A GOOD PUSH NORTHWARD BY TUESDAY...RESULTING
IN LOWER POPS AND HIGHER TEMPS. WILL ONLY CARRY LOW CHANCE POPS
ACROSS THE FAR NORTHERN CWA...WHILE HIGH TEMPS CLIMB INTO THE
LOWER TO MIDDLE 80S. AFTER THAT...MODEL SOLUTIONS VARY SOMEWHAT
CONCERNING HOW QUICKLY THE UPPER RIDGE EVENTUALLY BREAKS DOWN.
GIVEN AMPLIFIED PATTERN...THINK THIS WILL BE LATER RATHER THAN
SOONER...SO HAVE GONE WITH A VERY WARM AND DRY FORECAST THROUGH
THURSDAY. WEAKENING FRONTAL BOUNDARY MAY PUSH INTO THE REGION BY
THE END OF THE WEEK...SO HAVE INCLUDED CHANCE FOR SHOWERS/THUNDER
ON FRIDAY WITH CONTINUED WARM TEMPS WELL INTO THE 80S.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
701 AM EDT SAT MAY 25 2013
.AVIATION...
//DISCUSSION...
AMBIENT DRY AIR THROUGH AN IMPRESSIVE DEPTH WILL KEEP THE DOOR SHUT
ON PRECIPITATION CHANCES AS MIDLEVEL ENERGY PASSES THE STATE TO THE
SOUTH. THE ONLY IMPACT ON AVIATION CONDITIONS WILL BE SOME BKN-OVC
CEILINGS AT UPWARDS OF 25 KFT THIS MORNING. SURFACE WINDS TODAY ARE
EXPECTED TO EMERGE LIGHT NORTHERLY COMMENCING ON BOUNDARY LAYER
GROWTH. MODELS ARE HINTING AT SOME CUMULUS DEVELOPMENT THIS
AFTERNOON BUT THAT SEEMS SUSPECT ATTM.
//DTW THRESHOLD THREATS...
* NONE.
&&
.PREV DISCUSSION...ISSUED 325 AM EDT SAT MAY 25 2013
SHORT TERM...TODAY AND TONIGHT
EARLY MORNING MSAS ANALYSIS IS SHOWING A SURFACE RIDGE EXTENDING
SOUTHWARD THROUGH THE LAKE SUPERIOR/MICHIGAN/HURON BASINS. THE BEST
SURFACE RIDGING COMPONENT INSIDE OF THE CWA IS ACROSS THE NORTHERN
THUMB DOWN INTO PORT HURON. PERUSING THROUGH THE SURFACE
OBSERVATIONS...FEELING IS THE BEST POTENTIAL FOR ANY FROST FORMATION
WILL BE IN THE THUMB AND LOW LYING AREAS OF THE GLACIAL TERRAIN WITH
THE LOCAL OFFICE TEMPERATURE AT 33 DEGREES AS OF 230 AM LDT. WILL
MAINTAIN THE FROST ADVISORY AS IS FOR SIMPLICITY.
THERE HAS BEEN A DECENT RADAR PRESENTATION OVERNIGHT ACROSS PORTIONS
OF MN/WI/IA TIED TO THE AGEOSTROPHIC RESPONSE OF MERGING AND
SHEARING OF SHORTWAVE ENERGY. ONE HR PRECIPITATION AMOUNTS HAVE BEEN
LESSENING AS THE PRECIPITATION/VIRGA PUSHES FARTHER TO THE SOUTHEAST.
THIS IS LIKELY IN RESPONSE TO INCREASING CONFLUENCE ALOFT AS THE
ENTRANCE REGION LIES DIRECTLY OVER LOWER MICHIGAN. THE BEST UPPER
LEVEL FORCING IN THE FORM OF 700-500MB FRONTOGENESIS WILL BRUSH FAR
SOUTHWESTERN SECTIONS OF THE STATE BETWEEN 12-15Z...BEFORE PASSING
HARMLESSLY TO THE SOUTH. THE AMOUNT OF AMBIENT DRY AIR IN THE LOWEST
12 KFT AGL SUPPORTS VIRTUALLY NO PRECIPITATION POTENTIAL TODAY. THE
PREFERENCE REGARDING HIGH CLOUD PROG LIES WITH THE 25.05Z RUC WHICH
BRINGS HIGH CLOUDS INTO THE SOUTHWESTERN 2/3RDS OF THE CWA BETWEEN
9-16Z THIS MORNING. INCREASED INSOLATION WITH SOME MODERATION OF THE
AIRMASS WILL SUPPORT A SOLID 3-8F DEGREE UPTICK IN HIGH TEMPERATURES.
EXPECT READINGS TO RANGE FROM THE MIDDLE 50S IN THE FAR NORTHERN
THUMB/LAKE HURON SHORELINE TO THE MIDDLE 60S DETROIT SOUTHWARD.
SURFACE HIGH PRESSURE WILL EXPAND ACROSS THE CENTRAL GREAT LAKES
TONIGHT...BRINGING THE PROSPECTS OF ANOTHER COOL TO COLD NIGHT.
DIFFERENTIAL AIRMASS RECOVERY SHOULD BE GOOD FOR A FEW DEGREES OFF
THIS MORNINGS MINS. WORKED WITH A BLEND OF UNDERCUT GUIDANCE WITH
SOME PERSISTENCE. EXPECTED LOWS TONIGHT SHOULD RANGE FROM THE LOWER
TO MIDDLE 30S IN THE THUMB TO LOWER 40S SOUTHEAST OF THE TERRAIN.
LONG TERM...SUNDAY THROUGH FRIDAY
LOWER MICHIGAN WILL RESIDE BETWEEN A HIGH AMPLITUDE RIDGE ACROSS THE
UPPER MIDWEST AND A DEEP UPPER LOW LIFTING FROM NEW ENGLAND INTO THE
CANADIAN MARITIMES DURING THE LATER HALF OF THE WEEKEND...SUSTAINING
A CONFLUENT FLOW ALOFT. AT THE SFC...THIS WILL TRANSLATE TO HIGH
PRESSURE BUILDING FROM THE UPPER GREAT LAKES ON SUNDAY TO THE
EASTERN GREAT LAKES ON MONDAY. OTHER THAN THE POTENTIAL FOR SOME
HIGH CLOUDS...SKIES SHOULD REMAIN MAINLY CLEAR WITH VERY DRY AIR
OVERHEAD. TEMPS WILL SLOWLY MODERATE...LEADING TO AN OVERALL WARMING
TREND HEADING INTO MEMORIAL DAY. EXPECT MIXING DEPTHS MAY
OVERACHIEVE WITH PLENTY OF SUNSHINE AND SUBSTANTIAL LOW LEVEL DRY
AIR. THIS SUPPORTS LEANING TOWARD THE HIGHER END OF GUIDANCE MAX
TEMPS /MID TO UPPER 60S SUNDAY AND AROUND 70 MONDAY/. THE DRY
AIRMASS AND WEAK SFC GRADIENT WILL SUPPORT OPTIMAL RADIATIONAL
COOLING POTENTIAL...SO MINS SUN NIGHT WILL CONTINUE TO BE QUITE COLD
FOR LATE MAY /UPPER 30S TO MID 40S/.
THE MID LEVEL RIDGE IS FORECAST TO BREAK DOWN EARLY NEXT WEAK AS
NUMEROUS SHORT WAVE IMPULSES ARE EJECTED OUT OF THE LONG WAVE TROUGH
OVER THE WRN US AND ACROSS THE CNTRL/NRN PLAINS. THE BULK OF THE 00Z
MODEL SUITE SUGGEST MCS DEVELOPMENT ACROSS THE UPPER MIDWEST OR WRN
GREAT LAKES MON AFTERNOON/NIGHT AS LOW LEVEL INFLOW STRENGTHENS. THE
POTENTIAL FOR REMNANT MCS ACTIVITY TO ADVANCE INTO SE MI REMAINS
HIGHLY UNCERTAIN AT THIS TIME. WHILE SEVERAL MODEL SOLUTIONS ARE
QUITE BULLISH WITH QPF OVER SE MI MON NIGHT AND TUES...THERE IS
LIKELY SOME SEMBLANCE OF CONVECTIVE FEEDBACK IN THE MODELS. THERE IS
ALSO CONCERN THAT THE MODELS HAVE A POOR HANDLING OF MCS
PROPAGATION...WHICH COULD LEAD TO REMNANT CONVECTION BEING MUCH
FARTHER SOUTH. THUS PLAN TO CARRY VERY LOW CHANCE POPS TUESDAY.
PERSISTENT LOW LEVEL S-SWLY FLOW SHOULD HOWEVER LIFT A WARMER AND
MORE HUMID AIRMASS INTO SRN LOWER MI BY MID WEEK...MARKED BY THE
PASSAGE OF A SFC WARM FRONT. THIS WILL JUSTIFY A CHANCE OF
SHOWERS/THUNDERSTORMS LATE TUES THROUGH WED.
THE ECMWF REMAINS STEADFAST IN DEVELOPING A MORE AMPLIFIED UPPER
TROUGH OVER THE WRN US BY MIDWEEK AS ENERGY EJECTS OUT OF THE GULF
OF ALASKA AND INTO THE WEST COAST. A SEASONALLY STRONG UPPER JET
WITHIN THE BASE OF THE DEEP GULF OF ALASKA UPPER LOW AND CURRENT
AMPLIFIED NATURE OF THE FLOW LENDS SUPPORT TO THE ECMWF. THIS
SOLUTION BUILDS THE SUBTROPICAL RIDGE FARTHER NORTH INTO THE ERN US
LATE IN THE WEEK AND SUGGESTS SE MI MAY BE CAPPED. EVEN THE LESS
AMPLIFIED GFS BUILDS MID LEVEL HEIGHTS SUBSTANTIALLY ACROSS SE MI.
THUS THE FORECAST FOR THE LATER HALF OF NEXT WEEK WILL HAVE VERY LOW
POPS WITH MAX TEMPS WELL INTO THE 80S.
MARINE...
A STABLE ANTICYCLONE WILL EXPAND ACROSS THE GREAT LAKES THROUGH THE
HOLIDAY WEEKEND. THIS WEATHER FEATURE WILL BE RESPONSIBLE FOR MORE
TYPICAL MARINE CONDITIONS FOR LATE MAY. WAVE HEIGHTS ARE ONLY
EXPECTED TO RANGE IN THE 1 TO 2 FOOT RANGE IN MANY AREAS THROUGHOUT
THE WEEKEND.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY...MIZ047-MIZ048-MIZ049-MIZ053-MIZ054-MIZ055-MIZ060-
MIZ061-MIZ062-MIZ063-MIZ068-MIZ069-MIZ070-MIZ075-MIZ076-MIZ082-
MIZ083...UNTIL 8 AM SATURDAY.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....CB
SHORT TERM...CB
LONG TERM....SC
MARINE.......CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
600 AM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CDT SAT MAY 25 2013
INITIAL SHIELD OF WAA SHOWERS THAT WAS DEPICTED WELL ON 310K
ISENTROPIC SFC ON THE NAM/GFS IS FADING AWAY ACROSS WRN WI AS THIS
BATCH OF FORCING WEAKENS AND DIVES SOUTHEAST. IN ITS WAKE...WE HAVE
WAA AT H85...BUT THE DEEPER MOISTURE HAS PUSHED EAST...SO PRECIP HAS
CUT OFF PRETTY QUICK. WITH THE WAA AND WEAK MOISTURE
TRANSPORT...SHOULD BE ABLE TO GET SOME LIGHT SHOWERS/SPRINKLES
ACROSS MN THIS MORNING...BUT NOT MUCH MORE THAN THAT.
BEST CHANCE FOR RAIN TODAY WILL BE ACROSS SRN MN. WARM FRONT NOW CAN
BE FOUND ACROSS SOUTH CENTRAL NEB INTO NE KAN...WITH A STRONG LLJ
OVERRUNNING IT. THIS HAS GENERATED AN MCS OVER ERN NEB THIS MORNING.
THUNDER STARTING TO INCREASE ACROSS IA AS WELL AS THE LLJ HAS SLOWLY
WORKED EAST. MOST OF THIS THUNDERSTORM ACTIVITY WILL REMAIN SOUTH OF
MN THROUGH THE DAY...BUT ALL HI-RES MODELS SHOW SOME OF THIS
MOISTURE FROM IA SNEAKING UP INTO SOUTH CENTRAL MN THROUGH
MORNING...WHERE SOME HIGH CHANCE/LIKELY POPS ARE CONTINUED THROUGH
THE MORNING HOURS. FOR THE AFTERNOON...PRECIP LOOKS TO SHUT
OFF...BUT WE WILL BE STUCK WITH FAIRLY BROAD CLOUD COVER...WITH THE
ONLY HOPE FOR SOME BREAKS ACROSS THE NE MPX CWA THANKS TO THE
INFLUENCE OF A DRY SFC HIGH THAT WILL BE SPLAYED OUT ACROSS THE
GREAT LAKES. GIVEN THE CLOUD COVER WILL BE A COOL DAY...WITH
TEMPERATURES IN SOUTH CENTRAL MN LIKELY STAYING IN THE 50S THANKS TO
BETTER RAIN CHANCES AND THICKER CLOUD COVER.
FOR TONIGHT...ALL MODELS SHOW ANOTHER ROUND OF CONVECTION RIDING
ALONG NORTH OF THE WARM FRONT...KIND OF LIKE WHAT WE HAVE SEEN
OVERNIGHT TO OUR SOUTHWEST. QUESTION BECOMES HOW FAR NORTH DOES THE
ACTIVITY MAKE IT. CONSENSUS PLACEMENT FROM THE WARM FRONT PLACES IT
BY 12Z SUNDAY MORNING FROM THE BLACK HILLS...DOWN THROUGH
YANKTON...SD AND THEN DOWN TO THE CENTRAL IA/MO BORDER. ONCE
AGAIN...WILL SEE A LLJ OVERRUNNING THIS FRONTAL FEATURE...WHICH
SHOULD GENERATE YET ANOTHER MCS. GIVEN THE FRONTS PLACEMENT TO OUR
SOUTHWEST...BEST CHANCES FOR THUNDERSTORMS TONIGHT WILL BE SOUTH OF
THE UPPER MN RIVER IN SW MN INTO SC MN. FOR TIMING...FAVORED HIGHEST
POPS TO AFTER 6Z...AS CONVECTION SHOULD FIRE THIS EVENING OVER SE
SODAK INTO NE NEB...THEN HEAD TOWARD SW/SC MN. ALL OF THIS ACTIVITY
WOULD BE ELEVATED...SO SEVERE THREAT LOOKS MINIMAL...WITH THE MAIN
IMPACT BEING THE POTENTIAL FOR HEAVY RAIN...AS WE HAVE SEEN THIS
EVENING IN NEB.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 344 AM CDT SAT MAY 25 2013
THE LONG TERM PERIOD CONTINUES TO LOOK INCREASINGLY WET AND
STORMY. THIS IS DUE TO THE REGION BEING SANDWICHED BETWEEN A
BUILDING UPPER HIGH ALONG THE EASTERN SEABOARD... WHILE A VERY
DEEP TROUGH PUSHES INTO THE WESTERN HALF OF THE UNITED STATES.
THERE SHOULD BE A ROUND OF CONVECTION PASS ACROSS SOUTHERN MN
SUNDAY MORNING...VERY SIMILAR TO WHAT HAS BEEN ONGOING OVERNIGHT
ACROSS NE/IA. THE STORMS TO OUR SOUTH CURRENTLY HAVE BEEN BASICALLY
SUB SEVERE... BUT VERY EFFICIENT RAIN PRODUCERS... WITH UPWARDS OF
1.75 INCHES OF RAIN IN THREE HOURS. THIS IS THE TREND EXPECTED
SUNDAY MORNING ACROSS SOUTHERN MN... ESPECIALLY THE I-90
CORRIDOR. THEREAFTER... A SIGNIFICANT DIMINISHING TREND IN THE
PRECIPITATION FOR SUNDAY AFTERNOON AND EVENING WITH THE NMM/ARW
WRF/S IN AGREEMENT.
MEMORIAL DAY IS LOOKING A LITTLE WORSE NOW WITH EVEN THE ECMWF
DRIVING A WAVE OF CONVECTION ACROSS THE FA DURING THE DAY AND
EVENING. JUST GENERAL THUNDER INDICATED ON SWODY2 WHICH SEEMS
REASONABLE WITH THE MAIN WARM FRONTAL BOUNDARY MEANDERING FROM THE
CENTRAL PLAINS TO THE LOWER OHIO VALLEY. AGAIN... THE CONCERN WILL
BE LOCALIZED HEAVY RAINFALL. THE DETERMINISTIC RUNS WOULD ALSO
SUGGEST ANOTHER ROUND OF CONVECTION FOR US LATE MONDAY NIGHT AND
TUESDAY MORNING... ESPECIALLY ACROSS SOUTHERN MN.
THIS REPEATING ROUNDS OF POTENTIAL CONVECTION IS DISTURBING WITH
AREAS OF SOUTHERN AND ESPECIALLY SOUTHEAST MN RUNNING WELL ABOVE
NORMAL ON RAINFALL FOR THE MONTH OF MAY. THE THREAT FOR FLASH
FLOODING WILL BE ON THE INCREASE. IT WAS POINTED OUT ON FRIDAY
IN THE WEATHERTALK FROM DR SEELY AT THE UMN THAT SINCE MARCH
1ST...(METEOROLOGICAL SPRING) IT HAS BEEN ONE OF THE WETTEST IN
HISTORY FOR MANY AREAS OF MN. ADD THIS TO THE CIPS ANALOGS
FOR 5 DAYS FROM NOW AND ONE SEES A VERY WET PATTERN ACROSS ALL OF
THE REGION WITH 2 INCHES OF RAINFALL EXCEEDING 30 PERCENT
PROBABILITY WITH EVEN WIDESPREAD 3 INCHES HAVING A 10 PERCENT
PROBABILITY. THIS IS IN ADDITION TO THE RAINS SUNDAY THROUGH
TUESDAY. NOT SURPRISING THEN ARE THE RUN TOTALS FROM THE GFS AND
ECMWF THROUGH NEXT FRIDAY WHICH PAINT THE LANDSCAPE WITH 2 TO 4
INCHES OF RAIN... WITH 4 INCHES OR MORE SOUTH OF US. DIGRESSING
FOR A MOMENT... ONE OF THE MONTHS/YEARS THAT HAS SHOWN UP IN THE
CIPS ANALOGS RECENTLY IS JULY 1993... WITH RECORD FLOODING IN THIS
PART OF THE COUNTRY. A REVIEW FROM NCDC SHOWED LOW PRESSURE ALOFT
OVER THE WESTERN HIGH PLAINS WITH A STRONG SW JET AT 250 MB ACROSS
OUR AREA. THE BERMUDA HIGH HAD PUSHED INTO THE SOUTHEAST UNITED
STATES WITH ORGANIZED 850 MB WINDS FROM THE WESTERN GULF OF MEXICO
TO THE WESTERN GREAT LAKES. HENCE... THE FLOODING POTENTIAL IS A
BIG CONCERN FOR THE WEEK AHEAD AS THE PATTERN IN THE SUMMER OF
1993 MIMICS OUR WEEK AHEAD QUITE WELL.
FINALLY... AND JUST AS IMPORTANT... WILL BE THE THREAT FOR SEVERE
WEATHER NEXT WEEK AS THE WARM FRONT LIFTS NORTH INTO OUR AREA
BEGINNING ON TUESDAY. NOT TOO CONCERN ABOUT SEVERE ON SUNDAY. THE
CHANCE INCREASES SOME ON MONDAY (ISOLATED)...ESPECIALLY IF
AFTERNOON CONVECTION DEVELOPS AS DEEP LAYER SHEAR RISES. THEN FROM
TUESDAY ONWARD THERE IS SEVERE POTENTIAL EACH DAY. THE CIPS
ANALOGS CONTAIN MANY SEVERE REPORTS FOR US FOR THE MIDDLE OF NEXT
WEEK WITH SEVERE PROBABILITIES FROM 15 TO 30 PERCENT FOR THE
ENTIRE FA USING THE TOP 8 ANALOGS. A COLD FRONT MAY MOVE ACROSS
THE FA FROM FRIDAY INTO SATURDAY...DIMINISHING THE SEVERE WEATHER
THREAT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 600 AM CDT SAT MAY 25 2013
LOTS OF CONVECTION ON THE RADAR...BUT IT IS ALL WELL TO THE SOUTH.
MAY SEE A FEW SPRINKLES/LIGHT SHOWERS ACROSS MN THROUGH THE
MORNING...WITH ANYTHING MORE SUBSTANTIAL STAYING CONFINED TO THE
I-90 CORRIDOR. FOR THE REST OF THE DAY...WILL HAVE TO TRACK MVFR
CIGS EMANATING FROM THE TSRA ACTIVITY IN IOWA. CONTINUED TO FAVOR A
HRRR/RAP DEPICTION FOR THE HANDLING OF THESE LOW CLOUDS...KEEPING
MVFR CIGS DURING THE DAY CONFINED TO RWF. WITH SE FLOW...NAM ALONG
WITH THE RAP SHOW MVFR CIGS WORKING NW INTO NODAK...WHICH SHOULD
BRING MVFR CIGS TO AXN THIS AFTERNOON OR EVENING. MSP/STC LOOK TO BE
SITTING ON THE EDGE OF THE MVFR CIGS BY THE END OF THE TAF PERIOD
AND AT THIS POINT...STUCK WITH VFR CONDITIONS AT BOTH LOCATIONS
THROUGHOUT...THOUGH CERTAINLY SOME MVFR CIGS COULD BE SEEN AFTER
06Z. EXPECT ANOTHER ROUND OF THUNDERSTORMS TONIGHT...THOUGH WITH
WARM FRONT DRIFTING NORTH...STORMS SATURDAY NIGHT SHOULD BE A BIT
FARTHER NORTH OF WHERE THEY ARE NOW. BEST CHANCE FOR THUNDER LOOKS
TO BE ALONG/SOUTH OF THE MN RIVER...SO INTRODUCED SOME VCTS TO THE
END OF THE RWF TAF. FOR WINDS...THEY WILL BE REMARKABLY PERSISTENT
THIS PERIOD OUT OF THE SOUTHEAST...WITH WINDS TODAY EXPECTED TO
INCREASE TO NEAR WHAT WAS SEEN FRIDAY ACROSS MN.
KMSP...CONFIDENCE HIGH IN TAF THROUGH 06Z. AFTER 06Z...MVFR CIGS
THAT WILL BE SOUTHWEST OF THE FIELD WILL START TO PUSH NORTHEAST AND
COULD BEGIN TO IMPACT THE FIELD. HOWEVER...STICKING WITH THE THEME
OF THE GFS...WITH CIGS REMAINING ABOVE 4K FT. WILL ALSO HAVE TO
WATCH HOW ACTIVITY EVOLVES TO THE SOUTHWEST LATE TONIGHT...AS THERE
ARE INDICATIONS FROM THE GFS/ECMWF THAT SOME LIGHT ACTIVITY COULD
APPROACH THE FIELD SUNDAY MORNING. HOWEVER...AT THIS TIME...WITH THE
WARM FRONT EXPECTED DOWN ACROSS CENTRAL IOWA...FEEL BETTER SHRA/TSRA
CHANCES SUNDAY MORNING WILL BE DOWN ACROSS SOUTH CENTRAL MN...SO
KEPT ANY SORT OF PRECIP MENTION OUT OF THE TAF.
/OUTLOOK FOR KMSP/
SUN...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10-15 KTS.
MON...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10 KTS.
TUE...CHC MVFR OR LOWER CIGS. TSRA LIKELY. WINDS SSE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS HASTINGS NE
920 AM CDT SAT MAY 25 2013
.UPDATE...
ISSUED AT 920 AM CDT SAT MAY 25 2013
MCS HAS BASICALLY EXITED. RADAR IS SHOWING SOME SHWRS STILL
PERCOLATING FROM HLC-PHG AND DRIFTING NE TOWARD THE STATE LINE.
THESE SHWRS /WITH AN OCCASIONAL RUMBLE OF THUNDER/ WERE DEVELOPING
AS THE REMAINS OF THE LLJ ARE STILL LARGELY PERPENDICULAR TO THE
CONVECTIVELY-REINFORCED WARM FRONT THAT EXTENDS W-E ACROSS NRN KS.
EXPECT THESE SHWRS TO EVENTUALLY END. SO SHORT-TERM ADJUSTMENTS
THRU NOON HAVE ADJUSTED POPS AND SKYCOVER ACCORDINGLY.
12Z LBF/OAX/TOP SOUNDINGS SUPPORT HIGH TEMPS IN THE LOW-MID 80S E
OF HWY 281 AND MID-UPR 80S TO THE W.
WE WILL CONT TO EVALUATE TSTM AND SVR WX POTENTIAL FOR THIS AFTN-
EVE. CERTAINLY THE BOUNDARY LAID DOWN FROM THIS MCS WILL BE
WATCHED CLOSELY.
PLEASE FOLLOW OUR LSR/RTP/LCO PRODUCTS FOR THE IMPRESSIVE RAINFALL
TOTALS OVERNGT. MANY REPORTS OF 2-3" IN A SWATH FROM SHERMAN-HALL-
HAMILTON-CLAY-THAYER COUNTIES. THIS MAY SET THE STAGE FOR SOME
FLOODING WITH MULTIPLE THREATS OF TSTMS THE NEXT SVRL DAYS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM CDT SAT MAY 25 2013
FOCUS REMAINS ON TSTM POTENTIAL.
TSTMS CONTINUE EARLY THIS MORNING WITH MCS ROLLING EAST ACROSS
CENTRAL/EASTERN NEBRASKA. MAIN IMPACT CURRENTLY FM CONVECTION IS HEAVY
RAINFALL...WITH MANY LOCATIONS NORTH OF INTERSTATE 80 PICKING UP
AT LEAST AN INCH OF RAIN. WE HAVE HAD ONE REPORT OF 3.13 INCHES SO
FAR AT LOUP CITY WITH RAIN STILL FALLING.
THIS INITIAL ROUND OF CONVECTION WILL CONTINUE TO MOVE EAST/END THIS
MORNING THEN ATTENTION TURNS TO ADDITIONAL CHANCES FOR CONVECTION
THIS AFTN. SFC BOUNDARY HAS SETTLED NEAR THE NEB/KS STATELINE AND
FRONT IS PROGGED TO LIFT NORTHWARD THIS AFTN INTO SC NEB...WITH SFC
LOW ORIENTED IN EASTERN COLORADO AND DRY LINE ALONG THE HIGH PLAINS
REGION. FRONTAL BOUNDARY AND ANY RESIDUAL OUTFLOW BOUNDARIES WILL BE
FOCUS FOR CONVECTION AGAIN THIS AFTN/EVE AND BOUNDARY PLACEMENT
WILL NEED TO BE MONITORED CLOSELY. CAP LOOKS TO HOLD INITIALLY
HOWEVER MODELS ARE INDICATING DEVELOPMENT ALONG THE DRY LINE AND
ALONG/NORTH OF WARM FRONTAL BOUNDARY...AND HAVE FOLLOWED CLOSER TO
RAP MODEL FOR POTENTIAL DEVELOPMENT THIS AFTN. STORMS FOR
TODAY/TONIGHT HAVE THE POTENTIAL TO BE MORE VOLATILE WITH SEVERE
PARAMETERS INDICATING POTENTIAL FOR SUPERCELLS. INSTABILITY IS
PROGGED AROUND 4000 J/KG WITH SHEAR OF 40KTS OR SO AND STORMS WILL
BE CAPABLE OF PRODUCING VERY LARGE HAIL...DAMAGING WINDS AND EVEN
TORNADOES IN VCNTY OF BOUNDARIES. HEAVY RAINFALL/FLOODING ALSO
REMAINS A CONCERN DUE TO THE HEAVY OVERNIGHT/EARLY THIS MORNING
AND PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH TO INCH
AND A HALF AND ARE A 100 TO 150 PERCENT OF NORMAL. ALL OF THIS
BEING SAID...MODELS ARE NOT CONSISTENT IN FRONTAL POSITION WHICH
IS KEY TO DEVELOPMENT THIS AFTN. AGAIN FEEL RAP AND LATEST SREF
RUN HAS A BETTER HANDLE ON THE FARTHER SOUTH WARM FRONTAL POSITION
ACROSS OUR AREA TODAY...AND WILL NEED TO MONITOR CLOSELY.
OTHERWISE...LOOK FOR SOME WARMER TEMPS THIS AFTN AND STEADY/GUSTY
WINDS WITH THE HIGHEST WIND SPEEDS EXPECTED ACROSS NC KANSAS/SOUTH
OF WARM FRONT...WHERE WINDY CONDITIONS ARE POSSIBLE WITH GUSTS OF
30+ MPH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 423 AM CDT SAT MAY 25 2013
SUNDAY THROUGH FRIDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS MOST EVERY DAY AND TEMPERATURES THROUGH
THE PERIOD.
A VERY ACTIVE WEATHER PATTERN WILL AFFECT THE FORECAST AREA THROUGH
THE PERIOD. AN UPPER LEVEL LOW DEVELOPS IN THE WESTERN CONUS AND
GRADUALLY MOVES THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS BY FRIDAY. THIS UPPER LOW WILL SEND WAVES INTO THE FORECAST
AREA THROUGH THE PERIOD. THE MODELS ARE SIMILAR IN THE MAIN
FEATURES...BUT THE ECMWF HAS A LITTLE STRONGER AMPLITUDE MID WEEK.
EACH OF THE WAVES WILL HAVE A CHANCE FOR SOME THUNDERSTORMS WHEN
THEY MOVE THROUGH. IT CERTAINLY WILL NOT BE A RAIN OUT...IT WILL NOT
RAIN ALL OF THE TIME...BUT THERE WILL BE CHANCES FOR SOME SHOWERS
AND THUNDERSTORMS AT VARIOUS TIMES DURING THE PERIOD.
THE BEST CHANCES FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND
SUNDAY NIGHT...DURING WHICH TIME THE CAPE APPROACHES 5000 J/KG.
ANOTHER GOOD CHANCE WILL BE MONDAY AFTERNOON AND MONDAY NIGHT WITH
CAPES OVER 5000 J/KG AGAIN. BEYOND MONDAY THE MODELS HAVE A FEW
TIMING DIFFERENCES WITH THE UPPER LEVEL WAVES THAT MOVE THROUGH THE
AREA AND THEREFORE TIMING THUNDERSTORMS IS MORE OF A CHALLENGE.
TEMPERATURES WILL BE THE WARMEST SUNDAY THROUGH TUESDAY THEN SLOWLY
COOL OFF TOWARD THE END OF THE WEEK. TEMPERATURES SHOULD STILL
REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 540 AM CDT SAT MAY 25 2013
TSTMS CONTINUE IN THE VICINITY OF KGRI EARLY THIS MORNING. THIS
INITIAL ROUND OF CONVECTION WILL END THIS MORNING WITH
REDEVELOPMENT OF STORMS FORECAST THIS AFTN AND EVENING. LOOK FOR
VARIABLE WINDS TO TRANSITIION SOUTHERLY TODAY...BUT WILL BE
VARIABLE/GUSTY IN VCNTY OF STORMS. CIGS/VSBYS WILL MAINLY BE VFR BUT
WILL DROP TO MVFR AND POTENTIALLY NEAR IFR DURING TSTM ACTIVITY.
SEVERE STORMS ARE POSSIBLE LATER TODAY/TONIGHT WITH LARGE
HAIL/DAMAGING WINDS/HEAVY RAINFALL THE MAIN HAZARDS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...JCB
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
543 AM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM CDT SAT MAY 25 2013
FOCUS REMAINS ON TSTM POTENTIAL.
TSTMS CONTINUE EARLY THIS MORNING WITH MCS ROLLING EAST ACROSS
CENTRAL/EASTERN NEBRASKA. MAIN IMPACT CURRENTLY FM CONVECTION IS HEAVY
RAINFALL...WITH MANY LOCATIONS NORTH OF INTERSTATE 80 PICKING UP
AT LEAST AN INCH OF RAIN. WE HAVE HAD ONE REPORT OF 3.13 INCHES SO
FAR AT LOUP CITY WITH RAIN STILL FALLING.
THIS INITIAL ROUND OF CONVECTION WILL CONTINUE TO MOVE EAST/END THIS
MORNING THEN ATTENTION TURNS TO ADDITIONAL CHANCES FOR CONVECTION
THIS AFTN. SFC BOUNDARY HAS SETTLED NEAR THE NEB/KS STATELINE AND
FRONT IS PROGGED TO LIFT NORTHWARD THIS AFTN INTO SC NEB...WITH SFC
LOW ORIENTED IN EASTERN COLORADO AND DRY LINE ALONG THE HIGH PLAINS
REGION. FRONTAL BOUNDARY AND ANY RESIDUAL OUTFLOW BOUNDARIES WILL BE
FOCUS FOR CONVECTION AGAIN THIS AFTN/EVE AND BOUNDARY PLACEMENT
WILL NEED TO BE MONITORED CLOSELY. CAP LOOKS TO HOLD INITIALLY
HOWEVER MODELS ARE INDICATING DEVELOPMENT ALONG THE DRY LINE AND
ALONG/NORTH OF WARM FRONTAL BOUNDARY...AND HAVE FOLLOWED CLOSER TO
RAP MODEL FOR POTENTIAL DEVELOPMENT THIS AFTN. STORMS FOR
TODAY/TONIGHT HAVE THE POTENTIAL TO BE MORE VOLATILE WITH SEVERE
PARAMETERS INDICATING POTENTIAL FOR SUPERCELLS. INSTABILITY IS
PROGGED AROUND 4000 J/KG WITH SHEAR OF 40KTS OR SO AND STORMS WILL
BE CAPABLE OF PRODUCING VERY LARGE HAIL...DAMAGING WINDS AND EVEN
TORNADOES IN VCNTY OF BOUNDARIES. HEAVY RAINFALL/FLOODING ALSO
REMAINS A CONCERN DUE TO THE HEAVY OVERNIGHT/EARLY THIS MORNING
AND PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH TO INCH
AND A HALF AND ARE A 100 TO 150 PERCENT OF NORMAL. ALL OF THIS
BEING SAID...MODELS ARE NOT CONSISTENT IN FRONTAL POSITION WHICH
IS KEY TO DEVELOPMENT THIS AFTN. AGAIN FEEL RAP AND LATEST SREF
RUN HAS A BETTER HANDLE ON THE FARTHER SOUTH WARM FRONTAL POSITION
ACROSS OUR AREA TODAY...AND WILL NEED TO MONITOR CLOSELY.
OTHERWISE...LOOK FOR SOME WARMER TEMPS THIS AFTN AND STEADY/GUSTY
WINDS WITH THE HIGHEST WIND SPEEDS EXPECTED ACROSS NC KANSAS/SOUTH
OF WARM FRONT...WHERE WINDY CONDITIONS ARE POSSIBLE WITH GUSTS OF
30+ MPH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 423 AM CDT SAT MAY 25 2013
SUNDAY THROUGH FRIDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS MOST EVERY DAY AND TEMPERATURES THROUGH
THE PERIOD.
A VERY ACTIVE WEATHER PATTERN WILL AFFECT THE FORECAST AREA THROUGH
THE PERIOD. AN UPPER LEVEL LOW DEVELOPS IN THE WESTERN CONUS AND
GRADUALLY MOVES THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS BY FRIDAY. THIS UPPER LOW WILL SEND WAVES INTO THE FORECAST
AREA THROUGH THE PERIOD. THE MODELS ARE SIMILAR IN THE MAIN
FEATURES...BUT THE ECMWF HAS A LITTLE STRONGER AMPLITUDE MID WEEK.
EACH OF THE WAVES WILL HAVE A CHANCE FOR SOME THUNDERSTORMS WHEN
THEY MOVE THROUGH. IT CERTAINLY WILL NOT BE A RAIN OUT...IT WILL NOT
RAIN ALL OF THE TIME...BUT THERE WILL BE CHANCES FOR SOME SHOWERS
AND THUNDERSTORMS AT VARIOUS TIMES DURING THE PERIOD.
THE BEST CHANCES FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND
SUNDAY NIGHT...DURING WHICH TIME THE CAPE APPROACHES 5000 J/KG.
ANOTHER GOOD CHANCE WILL BE MONDAY AFTERNOON AND MONDAY NIGHT WITH
CAPES OVER 5000 J/KG AGAIN. BEYOND MONDAY THE MODELS HAVE A FEW
TIMING DIFFERENCES WITH THE UPPER LEVEL WAVES THAT MOVE THROUGH THE
AREA AND THEREFORE TIMING THUNDERSTORMS IS MORE OF A CHALLENGE.
TEMPERATURES WILL BE THE WARMEST SUNDAY THROUGH TUESDAY THEN SLOWLY
COOL OFF TOWARD THE END OF THE WEEK. TEMPERATURES SHOULD STILL
REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 540 AM CDT SAT MAY 25 2013
TSTMS CONTINUE IN THE VICINITY OF KGRI EARLY THIS MORNING. THIS
INITIAL ROUND OF CONVECTION WILL END THIS MORNING WITH
REDEVELOPMENT OF STORMS FORECAST THIS AFTN AND EVENING. LOOK FOR
VARIABLE WINDS TO TRANSITIION SOUTHERLY TODAY...BUT WILL BE
VARIABLE/GUSTY IN VCNTY OF STORMS. CIGS/VSBYS WILL MAINLY BE VFR BUT
WILL DROP TO MVFR AND POTENTIALLY NEAR IFR DURING TSTM ACTIVITY.
SEVERE STORMS ARE POSSIBLE LATER TODAY/TONIGHT WITH LARGE
HAIL/DAMAGING WINDS/HEAVY RAINFALL THE MAIN HAZARDS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...JCB
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
639 AM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT SAT MAY 25 2013
THUNDERSTORM COMPLEX OVER NEBRASKA OVERNIGHT CONTINUES EARLY THIS
MORNING. SEEING SHOWERS AND STORMS BEGINNING TO EXPAND ACROSS
NORTHWEST IOWA AS WELL AS LOW LEVEL THETAE ADVECTION INCREASES. HIGH
RES MODEL SUITE LOOK TO HAVE A PRETTY GOOD HANDLE ON THIS ACTIVITY.
EXPECT IT TO CONTINUE THIS MORNING AND POSSIBLY EXPAND A BIT FURTHER
NORTH INTO PORTIONS OF SOUTHWEST MINNESOTA. LOWERED POPS ACROSS
SOUTHEAST SOUTH DAKOTA...AS ALL INDICATIONS ARE THAT THESE STORMS
WILL NOT DEVELOP NORTHWEST OF THEIR CURRENT LOCATION. MOST OF THE
STORMS SHOULD BE EAST OF THE CWA BY 16Z. MAIN IMPACTS WILL BE
BRIEFLY HEAVY RAIN AND POSSIBLY SMALL HAIL WITH THESE CELLS...AS
EFFECTIVE SHEAR AND CAPE ARE TOO LOW FOR ANY SEVERE THREAT. MUCH OF
THE AFTERNOON SHOULD THEN BE DRY ACROSS THE CWA WITH AN AREA OF
SUBSIDENCE LIKELY BEHIND THIS MORNINGS SHORTWAVE. WARM FRONTAL
BOUNDARY WILL POSITION ITSELF SOUTH OF THE MISSOURI RIVER THIS
AFTERNOON. HRRR AND RAP TRY TO BREAK THE CAP THEIR THIS
AFTERNOON...BUT BOTH THESE MODELS SEEM A BIT OVERDONE WITH DEWPOINTS
AND INSTABILITY. FEEL MORE LIKELY SCENARIO IS ACTIVITY WAITS FOR THE
LOW LEVEL JET TO KICK IN AFTER 0Z BEFORE IT GETS GOING.
OTHER ISSUE TODAY IS CLOUD COVER AND HIGH TEMPERATURES.
INTERESTINGLY THE HRRR AND RAP ARE COMPLETE OPPOSITE OF EACH
OTHER...GIVING AROUND A 20 DEGREE DIFFERENCE IN HIGHS...WITH THE RAP
HAVING MORE STRATUS AND COOLER TEMPERATURES. THE GEM AND ECMWF SIDE
CLOSER TO THE RAP...WITH THE NAM IN BETWEEN. SINCE THE AREAL
COVERAGE OF LOW STRATUS IS CURRENTLY LESS THAN EXPECTED...DID GO
AHEAD AND RAISE HIGHS SEVERAL DEGREES FOR TODAY IN OUR CENTRAL AND
WEST. ALSO THE HRRR HAS A GOOD HANDLE ON THE CURRENT SITUATION...SO
ONE WOULD THINK ITS SHORT RANGE FORECAST SHOULD BE SOMEWHAT
RELIABLE...AND IT HAS CONSISTENTLY BEEN WARM FOR TODAY. LOWERED
HIGHS A FEW IN THE EAST WHERE IT IS RAINING...AND WHERE STRATUS
SHOULD INDEED HOLD IN FOR MUCH OF THE DAY. AGAIN THIS IS A PRETTY
LOW CONFIDENCE TEMPERATURE FORECAST FOR ANYWHERE EAST OF THE JAMES
RIVER. BUT FEEL GOING FORECAST IS A DECENT STARTING POINT...WITH THE
DAY SHIFT LIKELY HAVING TO ADJUST UP OR DOWN DEPENDING ON CLOUD
COVER TRENDS.
QUIET SHORT TERM CONDITIONS FROM THE AFTERNOON HOURS SHOULD TURN
QUICKLY TO MORE STORMY CONDITIONS OVERNIGHT. GAVE A FAIR AMOUNT
OF CREDIT TO THE CONSISTENCY OF THE 00Z HIGH RESOLUTION NAMDNG5
AND WRF-ARW SOLUTIONS...WHICH FIT THE OVERALL CONCEPTUAL MODEL FOR
CONVECTIVE INITIATION TONIGHT. BOUNDARY FROM CURRENT NIGHT MCS
WILL BE FESTERING AND DRIFTING NORTHWARD...WITH LIKELY 1000 TO
1500 J/KG ELEVATED CAPE LIFTED FROM 1 TO 1.5 KM AGL. AS 35 TO 40
KNOT LOW LEVEL JET DEVELOPS TONIGHT THROUGH THE CENTRAL PLAINS...
SHOULD BECOME ENOUGH TO INITIATE ELEVATED THUNDERSTORMS NEAR/NORTH
OF THE BOUNDARY WHICH WILL BE DRIFTING NORTHWARD OF INTERSTATE 80
DURING THE EVENING HOURS. EFFECTIVE SHEAR IN AREAS NORTH OF THE
BOUNDARY WILL BE VERY CONCENTRATED IN THE 1-3KM LAYER WITH STRONGEST
WINDS IN LOW LEVELS AND WEAKENING MID LEVEL WINDS ROUGHLY 20-30
KNOTS...WITH LESSER DEEP LAYER SHEAR CONTRIBUTIONS FROM ABOVE. ALL
SUGGEST AT LEAST A MINIMAL THREAT FOR ISOLATED LARGER HAIL OR
DAMAGING WINDS THROUGH THE MISSOURI RIVER CORRIDOR AND LIFTING
SOMEWHAT NORTHWARD THROUGH 066-08Z. OTHER SIGNIFICANT CONVECTIVE
INITIATION IS LIKELY TO OCCUR BACK THROUGH THE WESTERN HIGH PLAINS
WHERE STRONGER SHEAR EXISTS WITH A BIT STRONGER MID LEVEL WINDS
TO AROUND 25 KNOTS...AS WELL AS THE DEEP UPSLOPE TRANSPORT OF MOISTURE
TO RESULT IN STRONGER INSTABILITY. EVENTUALLY...WHEN SUPERCELL MOTIONS
WHICH WILL TAKE ACTION MORE SOUTHWARD THAN EAST START TO EASE...AND
LOW LEVEL JET VEERS EASTWARD...WILL FIND A MORE LINEAR MCS LIKELY
TAKING SHAPE. MANY HI RES MODELS SUGGEST THIS MCS WILL ZIPPER DOWN
THE LOCATION OF THE WARM ADVECTION WING SPREADING NORTHWARD...MOVING
TOWARD EAST CENTRAL SD AND SOUTHWEST MN LATE NIGHT. SEVERE THREAT
WITH THIS FEATURE WOULD SEEM TO BE SOMEWHAT LOWER...BUT LIKELY TO
GET SOME GUSTY WINDS AND AREAS OF HEAVY RAINFALL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 430 AM CDT SAT MAY 25 2013
MCS EXPECTED TO WEAKEN AND SHIFT EAST ON SUNDAY...AND WITH MID
LEVEL FORCING SHOWING TENDENCY TO FORCE SUBSIDENCE AROUND
MIDDAY...AGAIN EXPECT THAT MUCH OF THE DAYTIME PERIOD WILL
PROBABLY END UP PRECIPITATION FREE. HOWEVER...CLOUDS LIKELY TO
PERSIST WITH STRATUS DEVELOPING IN WAKE OF SYSTEM. MOST LIKELY TO
GET BREAKS THROUGH THE WESTERN AND SOUTHERN CWA DURING THE
AFTERNOON...AND HAVE PUSHED EXPECTED TEMPS TO NEAR 80 THERE...
WHILE MORE MID TO UPPER 60S LINGER IN THE FAR EAST. RESULT OF THIS
WILL BE GENERATION OF DECENT POTENTIAL INSTABILITY OF 1500-2000
J/KG ACROSS THE AREA...WITH WEAKEST OF THE CAPPING INVERSION NEAR
THE MISSOURI RIVER CORRIDOR. SHEAR BECOMES A BIT MORE DISTRIBUTED
THROUGH THE EFFECTIVE LAYER...AND FAIRLY CLOSE TO THOSE VALUES
FROM THIS EVENING FROM 30 TO 35 KNOTS. A FEW MORE SEVERE STORMS
WOULD BE POSSIBLE MAINLY THROUGH THE SOUTHWEST HALF OF THE AREA
DURING THE LATER AFTERNOON AND EVENING HOURS...AS INITIATION
LIKELY TO BE A RESULT OF WEAK IMPULSE SLIDING UP BACK SIDE OF
RIDGE IN THE LATER AFTERNOON AND EARLY EVENING.
THE FURTHER ONE GOES INTO THE FORECAST...THE LESS RELIABLE ANY
GUIDANCE BECOMES GIVEN THE ABUNDANCE OF CONVECTION...AND THE
INCREASINGLY GREAT UNCERTAINTY AS TO WHERE CRITICAL BOUNDARIES MAY
LIE. ONE THING FOR SURE...GIVEN THE CLOSED LOW ACROSS THE WESTERN
U.S. AND THE SOUTHWEST FLOW ALOFT...DIFFICULT TO PINPOINT ANY TIME
FROM MONDAY ON THAT ONE COULD SAY THERE WAS ABSOLUTELY NO CHANCE
FOR PRECIPITATION...BUT ON THE SAME FRONT IT CERTAINLY WILL NOT BE
AN ALL TIME WASHOUT WITH MANY BREAKS DEFINED ON THE MESOSCALE.
MEMORIAL DAY AND MONDAY NIGHT WILL PLACE THE AREA ON THE SOUTHERN
FLANK OF A COUPLE OF WAVES MOVING OVER THE RIDGE...SO LIKELY TO
HAVE ENHANCEMENT OF PRECIPITATION IN THE NOCTURNALLY FAVORED
PERIODS. WHILE A FEW SEVERE STORMS ARE AGAIN WELL WITHIN
REASON...HIGH PRECIPITABLE WATER AND FAIRLY SLOW MOVING WIND
PROFILES BRING THE CONCERN OF AREAS OF HEAVY RAINFALL...AT THIS
RANGE HARD TO DEFINE. AT THE MOMENT...THE PROSPECT FOR MORE
SIGNIFICANT CONVECTION AND SEVERE WEATHER WOULD APPEAR TO BE LATE
DAY WEDNESDAY INTO THURSDAY...AS DEEP WESTERN CLOSED LOW KICKS
STRONGER JET ENERGY INTO THE PLAINS. MOISTURE THROUGH LOWER LEVELS
/THUS INSTABILITY/ WILL CONTINUE TO BENEFIT FROM PERSISTENT
SOUTHERLY FLOW. TEMPERATURES WILL LIKELY GRAVITATE TO SOMEWHAT
ABOVE NORMAL READINGS THROUGH THE UPCOMING WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 619 AM CDT SAT MAY 25 2013
LOW CONFIDENCE TAF FORECAST. MANY GUIDANCE SOLUTIONS SHOWING IFR TO
MVFR STRATUS THIS MORNING. THESE SOLUTIONS SHOW IT DEVELOPING OVER
NEBRASKA AND IOWA AND ADVECTING INTO OUR AREA. WINDS ARE
SOUTHEASTERLY FROM 1500 FEET AND BELOW AND SOUTHWESTERLY ABOVE THAT.
THAT SOUTHWESTERLY WIND IS ADVECTING IN DRY AIR...THUS ONLY STRATUS
BELOW 1500 FEET WOULD BE ABLE TO ADVECT INTO THE AREA. CURRENTLY NOT
SEEING MUCH OF THAT OUT THERE. THUS CUT BACK ON THE LOW CIGS AND KEPT
MOST OF OUR AREA VFR. HOWEVER WILL HAVE TO MONITOR THINGS THROUGH THE
MORNING. NOT OUT OF THE QUESTION THAT LOW STRATUS STILL FORMS...OR
THAT WE GET SOME MVFR STRATOCU AFTER SUNRISE. NEXT PROBLEM IS
CONVECTION. THIS MORNINGS ACTIVITY SHOULD REMAIN EAST OF THE TAF
SITES AND EXIT THE CWA BY MID TO LATE MORNING. TONIGHT...EXPECT
ACTIVITY TO GET GOING IN THE VICINITY OF A LOW LEVEL WARM FRONT AFTER
03Z. WHERE THIS EXACTLY HAPPENS REMAINS UNCERTAIN. AT THIS POINT IT
APPEAR THAT AREAS NEAR THE MISSOURI RIVER HAVE THE BEST SHOT. ALSO
EXPECT A THUNDERSTORM COMPLEX TO FORM TO OUR NORTHWEST...AND DIVE
THROUGH THE AREA AFTER 7Z INTO THE MORNING HOURS. MAIN THREATS WILL
BE REDUCTIONS TO IFR VIS/CIG IN THE HEAVIER RAIN...BUT SOME HAIL AND
GUSTY WINDS ARE ALSO POSSIBLE. STRATUS MAY ALSO TRY TO FORM
TONIGHT...BUT THAT WILL BE DEPENDENT ON HOW WELL WE MIX OUT THE LOW
LEVEL MOISTURE TODAY. DID PUT MVFR CIGS IN THE TAFS STARTING THIS
EVENING...BUT THIS IS ALSO UNFORTUNATELY UNCERTAIN.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN/CHENARD
LONG TERM...CHAPMAN
AVIATION...CHENARD
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
631 AM CDT SAT MAY 25 2013
.AVIATION...
THE WEAK UPPER LOW OVER THE REGION WILL AGAIN RESULT IN AREAS OF
SHRA/TSRA THROUGHOUT THE DAY. RADAR MOSAIC SHOWS THIS ACTIVITY
CURRENTLY FROM THE KAUS/KSAT AREA NORTHWARD TO THE RED RIVER. AS
THE DAY PROGRESSES EXPECT CONVECTION TO INCREASE IN COVERAGE WITH
SOME AFFECTING THE TAF SITES MAINLY THIS AFTERNOON. AS THE UPPER
LOW MOVES FARTHER NORTHEAST TONIGHT...SOME ACTIVITY WILL LINGER
OVER THE AREA BUT IT SHOULD BE MOSTLY -RA AFTER 26/03Z.
AIRPORT OPERATIONS WILL BE AFFECTED BY LIGHTNING STRIKES...WET
RUNWAYS AND REDUCTIONS IN CIGS AND VIS DURING CONVECTION. KDFW
OPERATIONS SHOULD EXPECT AN AIRPORT WEATHER WARNING TO BE ISSUED
LATER TODAY AS LIGHTNING NEARS THE AIRPORT.
FOR THIS TAF CYCLE...MVFR CIGS ARE ON GOING AT KACT BUT THEY
SHOULD ARRIVE AT THE METROPLEX AIRPORTS 13-14Z. CIGS WILL LIFT
TO VFR BY LATE MORNING. MVFR CIGS WILL RETURN TO KDFW LATE TONIGHT
AROUND 26/09Z AND SHOULD END AROUND 26/16Z. 75
&&
.PREV DISCUSSION... /ISSUED 347 AM CDT SAT MAY 25 2013/
RADAR/SATELLITE LOOP INDICATES THAT THE WEAK MID LEVEL LOW IS
LIKELY LOCATED NEAR ABILENE AND 00Z 500MB ANALYSIS CONFIRMS IT IS
WARM-CORE IN NATURE. AS IS OFTEN THE CASE WITH WARM-CORE
LOWS...CONVECTION IS FIRING BEFORE SUNRISE ACROSS THE HILL
COUNTRY WITHIN A WEAK LOW LEVEL JET AXIS WHERE THETA-E ADVECTION
AND OROGRAPHIC LIFT ARE OCCURRING. SHORT-TERM MODELS SUCH AS THE
HRRR AND RUC SUGGEST THAT SCATTERED CONVECTION WILL CONTINUE TO
EXPAND NORTHWARD FROM CENTRAL TEXAS INTO THE WESTERN ZONES DURING
THE MORNING HOURS. THE GFS APPEARS TO BE SUFFERING FROM GRID SCALE
CONVECTIVE FEEDBACK WHICH IS RESULTING IN VERY HIGH QPF AND
CONTAMINATED MASS FIELDS...THUS THE GFS WILL NOT BE USED IN THE
SHORT-TERM. THE NAM SEEMS TO BE MATCHING CURRENT TRENDS AND SHORT-
TERM MODELS WELL AND THEREFORE IT GIVES CONFIDENCE TO RAISE POPS
TODAY. WE EXPECT THE BEST COVERAGE OF CONVECTION IN THE WESTERN
ZONES THIS MORNING. SCATTERED CONVECTION WILL BUILD/EXPAND
EASTWARD INTO THE EASTERN ZONES DURING THE MIDDAY/AFTERNOON HOURS.
THE AIRMASS OVER THE EASTERN ZONES WILL BE A BIT MORE UNSTABLE DUE
TO BETTER INSOLATION AND A COUPLE OF STRONG STORMS WITH GUSTY
WINDS WILL BE POSSIBLE...BUT DUE TO WEAK SHEAR THE SEVERE THREAT
IS LOW. HIGHS TODAY IN THE WESTERN ZONES WILL ONLY BE IN THE UPPER
70S TO LOW 80S DUE TO CLOUDS/RAIN...WITH HIGHS IN THE EASTERN
ZONES REACHING THE MID 80S. SCATTERED CONVECTION WILL CONTINUE
INTO THE EVENING HOURS BEFORE DISSIPATING WITH LOSS OF HEATING.
THE WARM CORE MID LEVEL LOW WILL BE EXITING THE REGION TO THE
NORTHEAST TONIGHT...AND THEREFORE THE RAIN CHANCES WILL COME TO AN
END. EXPECT A DRY SUNDAY WITH TEMPERATURES REBOUNDING INTO THE
MID-UPPER 80S AREA WIDE. AS AN UPPER LEVEL TROUGH DEVELOPS ACROSS
THE INTER-MOUNTAIN WEST...A SURFACE LOW WILL DEEPEN IN THE HIGH
PLAINS MONDAY. THIS WILL BRING BREEZY SOUTH WINDS TO THE REGION
MONDAY WHICH WILL LIKELY PERSIST THROUGH THE WEEK. LOW TEMPS WILL
WARM INTO THE 70S AREA WIDE BY MIDWEEK WITH HIGHS GENERALLY IN THE
MID 80S EAST TO LOW 90S WEST. THE SOUTHWEST FLOW ABOVE THE
SURFACE WILL BRING A THERMAL INVERSION INTO THE AREA. THUS THE
FORECAST LOOKS DRY UNLESS/UNTIL FORCING ARRIVES TO WEAKEN THE CAP.
MODEL GUIDANCE REMAINS IN POOR TO FAIR AGREEMENT REGARDING THE
EVOLUTION/EJECTION OF THE WEST COAST UPPER TROUGH MID-LATE WEEK.
THE ECMWF CONTINUES TO SHOW A VERY NEGATIVELY TILTED TROUGH
SWINGING THROUGH THE REGION LATE WEDNESDAY AND THURSDAY WHICH
WOULD BODE WELL FOR RAIN. BUT IT CONTINUES TO BE THE ONLY MODEL
THAT SHOWS THE TROUGH EJECTION LIKE THIS...AND FRANKLY THE 500MB
PATTERN IT PRESENTS JUST DOES NOT LOOK REALISTIC. IF IT WERE NOT
FOR THE ECMWF BEING THE BETTER OF THE LONG RANGE MODELS...I WOULD
DISCOUNT IT ALTOGETHER AND SHOW A DRY FORECAST ON THURSDAY...BUT
FOR NOW HAVE RETAINED THE SLIGHT CHANCE POPS. THE GFS/UKMET/GEM
FORECASTS SHOW THAT THE UPPER ENERGY NEEDED TO BREAK THE CAP WILL
LIKELY REMAIN WELL NORTHWEST OF THE REGION. FURTHERMORE...THE
DRYLINE ALSO LOOKS LIKE IT WILL REMAIN TOO FAR TO THE WEST...WITH
THE GFS SHOWING IT AS FAR WEST AS THE TX PANHANDLE. STORM MOTIONS
WILL GENERALLY BE NORTHEAST AND THIS MEANS STORMS WOULD NOT EVEN
HAVE A CHANCE TO PROPAGATE INTO THE CWA EITHER. SO IN SUMMARY THE
RAIN CHANCES ON THURSDAY AT THIS POINT ARE HINGING ON THE ECMWF
BEING CORRECT...AND THIS MAY BE A BIT OF A LONG SHOT.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 84 69 87 69 87 / 40 30 10 5 0
WACO, TX 83 68 87 68 89 / 50 30 10 5 0
PARIS, TX 83 67 85 66 85 / 30 30 10 5 0
DENTON, TX 84 67 86 68 87 / 40 30 10 5 0
MCKINNEY, TX 84 67 85 68 87 / 30 30 10 5 0
DALLAS, TX 85 71 87 70 89 / 30 30 10 5 0
TERRELL, TX 84 67 86 68 88 / 30 30 10 5 0
CORSICANA, TX 84 67 88 68 89 / 30 30 10 5 0
TEMPLE, TX 82 67 87 68 88 / 50 20 10 5 0
MINERAL WELLS, TX 81 66 87 67 89 / 40 20 10 5 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
75/
AREA FORECAST DISCUSSION
NWS SPOKANE WA
833 AM PDT Sat May 25 2013
.SYNOPSIS...
Memorial Day Weekend is expected to be a little cooler than
average, and a series of weak upper level disturbances will bring
the potential for scattered showers Sunday and Monday. The moist,
showery weather pattern is expected to linger into late next week.
&&
.DISCUSSION...
Update: Satellite imagery from this morning shows two closed
lows...one near the north Washington coast and another over
southern Alberta. Models show these two features moving very
little today. With no strong forcing mechanism to generate
showers...there should be less shower activity today compared to
yesterday. The 13z HRRR model shows most of the showers today
will be along the East Slopes of the Cascades and north of the
Columbia Basin over the northern mountains. This make sense given
these areas are in closest proximity to the two aforementioned
lows...and that showers are more likely to develop over the
mountainous terrain. Forecast has this part of the forecast well
handled with only change to lower mountain pops to 20 percent
through the morning with better chances holding off til afternoon
when instability increases.
Latest SREF and SPC guidance, as well as the 13z HRRR model shows
minimal thunder chances today. The better chances will be north of
the Canadian border...and over the Clearwaters. With cloud cover
this morning extensive over the Idaho Panhandle and northeast
Washington mountains...this will further lower convective
potential. Cloud cover was increased this morning over North
Idaho, and thunder was removed from the northern mountains, but a
slight chance was kept for the Camas Prairie with this area on the
edge of the best convective potential. Also lowered high
temperatures today a few degrees for Sandpoint and Kellogg. JW
&&
.AVIATION...
12Z TAFS: General trof over Eastern Washington and Northern Idaho
continues through this interval. Some late night and early morning
valley fog primarily in northern valleys with some showers at
times...primarily in the afternoon and early evening. VFR ceilings
and visibilities are expected to prevail through the 24 hour
interval. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 44 65 46 65 47 / 20 10 30 40 30 10
Coeur d`Alene 63 42 65 45 64 44 / 20 20 30 40 40 10
Pullman 64 43 63 44 65 46 / 10 10 30 40 20 20
Lewiston 71 48 70 50 71 51 / 10 10 30 40 20 20
Colville 67 41 72 45 69 44 / 40 30 20 20 50 20
Sandpoint 61 39 66 43 63 42 / 30 20 20 40 50 20
Kellogg 59 44 63 46 62 47 / 40 20 30 50 50 20
Moses Lake 72 46 73 49 73 50 / 10 10 30 20 10 20
Wenatchee 68 47 70 49 71 51 / 10 10 30 10 10 20
Omak 68 41 71 45 70 46 / 30 20 30 10 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
427 AM PDT Sat May 25 2013
.SYNOPSIS...
Memorial Day Weekend is expected to be a little cooler than
average, and a series of weak upper level disturbances will bring
the potential for scattered showers Sunday and Monday. The moist,
showery weather pattern is expected to linger into late next week.
&&
.DISCUSSION...
Today through Sunday...General trof pattern continues to influence
the sensible weather over Eastern Washington and Northern Idaho
keeping it unsettled at times along with temperatures on the cool
side of what would be considered normal this time of year. Last
few HRRR model runs hit at surface based convection over the
northern mountains after 11AM PDT today and upon further inspection
GFS runs for this interval show the cold pool aloft at 500mb
helping to keep the instability overhead extends west to overhang
parts of the cascades...thus the minor mention of afternoon and
early evening thunderstorms has been stretched westward to cover
parts of the East Slopes of the Northern cascades roughly north of
Leavenworth. Models also hint at a mesoscale shortwave or two
producing enough forcing to allow for some minor mention of
showers overnight...one near the cascades and the other passing
over the Blue Mountains up into North Idaho Panhandle. Sunday the
trof overhead is very very cluttered with synoptic and mesoscale
shortwave propagation through it which allows for the mention of
showers to persist. Forecast temps show a very slight cooling
trend as the flow turns a bit more southerly, which is a warm
trajectory most of the time, for Sunday. Additionally since the
jet stream is south of the forecast area through this time
interval resulting in a lowered tropopause (down to near 400mb)
some of these showers could produce the typical early spring
precipitation type (graupel or soft hail) for a spell along with
mixing moderate wind gusts down to the surface which is something
to keep in mind over the weekend. /Pelatti
Sunday Night through Wednesday: The cool upper level trough that
has been anchored over the Pacific Northwest since Wednesday is
expected to pivot into western Montana Sunday night into Monday
bringing scattered showers to the eastern third of Washington and
northern Idaho. Despite the displacement of this upper low, our
weather pattern isn`t expected to change much. There is good
agreement between the medium range models that the Polar Jet will
dive into southern Oregon and carve another upper level trough
over the Pacific Northwest. The best jet dynamics (Q-Vector
Divergence) Monday night into Tuesday should be over southern
Oregon into the Great Basin, but there will be enough moisture and
deep layer instability with the weakening frontal occlusion to
maintain a good chance of showers Tuesday and Tuesday night.
Depending on the timing of this system, we may need to add a
mention of thunderstorms on Tuesday. The 00z GFS, Canadian and
ECMWF are in pretty good agreement with a weak, negatively tilted
trough over central and western Washington. The GFS and ECMWF
are producing precipitation that looks convectively driven over
the north Cascades. The potential for thunderstorms over the burn
scars around Wenatchee, Ellensburg, and Chelan will be a concern
through the summer and we will continue to monitor patterns like
this one closely for mudslides and debris flows.
The axis of a west to east oriented upper trough is expected to
linger over the Pacific Northwest Wednesday and through the end of
the week. It does look like Tuesday`s frontal occlusion will bring
the most widespread shower activity to the region this week, but
afternoon and early evening showers will be in the forecast for
much of the week. /GKoch
Wednesday Night through Friday Night: Through this time frame we
continue to see an unsettled pattern that will continue to feature
the chance for precipitation across most of the Inland NW
especially for the higher terrains of the ID Panhandle along with
Cascade Crests earlier in the period. Models are in pretty good
agreement through Friday Afternoon by keeping a large scale
negatively tilted trough pattern in place allowing for moisture to
flow in behind the low center that pushes to our SE throughout the
night on Wednesday. With the increased moisture, there will be
thick cloud cover keeping temps in the lower 60s and 70s for
most correlating to below normal temps for this time of year. Low
temps will follow the same pattern of a couple degrees below
normal due to the lack of daytime heating. Towards the end of the
period models are indicating a ridge builds behind the exiting
trough which should help to diminish the precipitation
threat...lower the cloud coverage and ultimately push temperatures
closer to seasonal averages as we approach next weekend. Overall
not many changes were made to the forecast..just tinkered with the
POPs slightly to reflect most recent model data and trended the
temps in the same manner. /Fliehman
&&
.AVIATION...
12Z TAFS: General trof over Eastern Washington and Northern Idaho
continues through this interval. Some late night and early morning
valley fog primarily in northern valleys with some showers at
times...primarily in the afternoon and early evening. VFR ceilings
and visibilities are expected to pravail through the 24 hour
interval. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 44 65 46 65 47 / 20 10 30 50 30 10
Coeur d`Alene 63 42 65 45 64 44 / 20 20 30 50 40 10
Pullman 64 43 63 44 65 46 / 10 10 30 50 20 20
Lewiston 71 48 70 50 71 51 / 10 10 30 50 20 20
Colville 67 41 72 45 69 44 / 40 30 20 20 50 20
Sandpoint 63 39 66 43 63 42 / 30 20 20 40 50 20
Kellogg 61 44 63 46 62 47 / 40 20 30 60 50 20
Moses Lake 72 46 73 49 73 50 / 10 10 30 20 10 20
Wenatchee 68 47 70 49 71 51 / 10 10 30 10 10 20
Omak 68 41 71 45 70 46 / 30 20 30 10 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
302 PM MDT SAT MAY 25 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 301 PM MDT SAT MAY 25 2013
...FIRE WEATHER CONCERNS CONTINUE ACROSS THE MTS...AND INCREASE
ACROSS THE SOUTHERN PLAINS ON SUNDAY..
DEEPENING SFC LOW IN VCNTY OF KLHX HAS SPREAD SOME GUSTY SOUTHWEST
WINDS ACROSS THE MOUNTAINS AND SOUTHERN PORTIONS OF THE SE PLAINS.
AS OF 20Z...SFC DRY LINE IS LOCATED ALONG A LINE FROM JUST EAST OF
KLAA...TO NEAR KSPD. TO THE WEST OF THIS LINE...DEW POINTS HAVE BEEN
DROPPING INTO THE SINGLE DIGITS...TEENS AND EVEN SOME NEGATIVE
READINGS ACROSS THE MOUNTAINS. TO THE EAST OF THE DRY LINE...DEW
POINTS ARE STILL IN THE UPPER 40S TO LOWER 50S. LATEST HRRR STILL
PUSHES THE DRY LINE INTO WESTERN KS BY 22Z...WITH DEW POINTS
DROPPING INTO THE 30S ALONG THE EASTERN BORDER. STILL CONCERNED
THAT SOME INITIAL CONVECTION MAY FIRE ALONG THE DRY LINE LATE THIS
AFTERNOON...SO WILL MAINTAIN SOME ISOLATED POPS OUT THAT WAY. MOST
OF IT WILL BE HIGH BASED...WITH GUSTY WINDS AND LIGHTNING THE MOST
LIKELY THREATS. COULDN`T RULE OUT SOME MARGINAL SEVERE HAIL AND
WIND GUSTS NEAR THE CO/KS BORDER IF CAPES CAN STAY UP HIGH ENOUGH.
SPC HAS UPDATED THE LATEST OUTLOOK TO INCLUDE EASTERN
KIOWA...PROWERS...AND BACA COUNTIES. INITIALLY 0-6 KM SHEAR VALUES
ARE AROUND 20-30 KTS WHICH IS MARGINAL FOR SEVERE...BUT THESE VALUES
DO INCREASE INTO THE EVENING...SO THIS AREA WILL NEED TO BE
MONITORED. EXPECT CONVECTION TO SHIFT QUICKLY EASTWARD INTO KS
THROUGH THE LATE AFTN/EARLY EVENING...THOUGH OUTFLOWS MAY AID
WESTWARD RETREAT OF THE DRY LINE.
OVERNIGHT...DRY LINE PROGRESSES BACK WESTWARD BEFORE MIXING BACK
EASTWARD DURING THE DAY ON SUNDAY AS AN UPPER JET IN SOUTHWEST FLOW
ALOFT MOVES ACROSS THE AREA. CURRENT FIRE WEATHER WATCH WILL BE
UPGRADED TO A RED FLAG WARNING WITH THE AFTERNOON PACKAGE AS ALL
AREAS LOOK TO MEET CRITICAL FIRE WEATHER CONDITIONS. SFC BOUNDARY
HANGS UP JUST NORTH OF THE AREA AND WITH DRY LINE EXPECTED TO PUSH
INTO WESTERN KS DURING THE AFTERNOON...WILL GO WITH NIL POPS FOR THE
ENTIRE CWA. LOOKS LIKE HIGHS TOMORROW SHOULD STAY AROUND 3-5 DEGREES
BELOW RECORDS (COS 90...2012 PUB 97...2012 ALS 84...1969)...THOUGH
STILL WAY ABOVE CLIMATOLOGICAL AVERAGES. -KT
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 301 PM MDT SAT MAY 25 2013
SUNDAY NIGHT-MONDAY NIGHT...MODERATE WARM AND DRY SOUTHWEST FLOW
ALOFT CONTINUES ACROSS THE REGION AS A BROAD UPPER TROUGH SLOWLY
DIGS ACROSS THE PAC NORTHWEST AND INTO THE GREAT BASIN. MODELS
CONTINUE TO INDICATE A WEAK EMBEDDED SHORT WAVE TRANSLATING ACROSS
THE ROCKIES SUNDAY NIGHT WITH ANOTHER MINOR WAVE MOVING ACROSS THE
STATE LATE MONDAY AFTERNOON. FIRST WAVE SENDS A WEAK BACKDOOR COLD
FRONT ACROSS EASTERN COLORADO EARLY MONDAY MORNING BEFORE FRONT
MIXES OUT THROUGH THE EARLY AFTERNOON. MODELS ALSO INDICATING
INCREASING MID AND HIGH LEVEL MOISTURE ASSOCIATED WITH SECOND WAVE
SPREADING ACROSS THE AREA THROUGH THE DAY ON MONDAY...WHICH LOOKS TO
LIMIT STRONGER WINDS ALOFT FROM MIXING DOWN THROUGH THE AFTERNOON.
AT ANY RATE...COULD SEE BRIEF RED FLAG CONDITIONS DEVELOPING ACROSS
THE EASTERN MTS LATE MONDAY AFTERNOON...BUT LOOKS TO BE TOO MARGINAL
TO ISSUE ANY HIGHLIGHTS AT THIS TIME. WITH THE PASSING WAVES...COULD
SEE SOME HIGH BASED CONVECTION MONDAY AFTERNOON AND EARLY EVENING
ACROSS MAINLY THE CENTRAL AND EASTERN MTS WITH HIGHS EXPECTED TO BE
ONLY SLIGHTLY COOLER THAN SUNDAY.
TUESDAY-THURSDAY NIGHT...FIRE DANGER EXPECTED TO INCREASE ACROSS
SOUTHERN COLORADO AS GREAT BASIN UPPER TROUGH SLOWLY LIFTS OUT
ACROSS THE NORTHERN ROCKIES THROUGH THE PERIOD. INCREASING SOUTH TO
SOUTHWEST FLOW ACROSS THE AREA TUESDAY DEVELOPS A LA JUNTA LOW
TUESDAY AFTERNOON SUPPORTING THE POTENTIAL FOR CRITICAL FIRE WEATHER
CONDITIONS ACROSS THE SOUTHERN MTS AND ADJACENT PLAINS AS WELL AS
ACROSS THE FAR SOUTHEAST PLAINS...WITH SOME MORE HIGH BASED STORMS
POSSIBLE ACROSS THE CENTRAL MTS AND SOUTHWEST MTS. MORE WIDESPREAD
CRITICAL FIRE WEATHER CONDITIONS LOOK TO BE POSSIBLE ACROSS SOUTHERN
COLORADO WEDNESDAY AND THURSDAY WITH BREEZY TO WINDY WEST TO
SOUTHWEST FLOW ALOFT. PASSING TROUGH KEEPS CHANCE AND SLIGHT CHANCES
OF THUNDERSTORMS ACROSS THE AREA TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT...WITH BEST CHANCES ACROSS NORTHERN PORTIONS OF THE AREA.
MODELS KEEP BEST LOW LEVEL MOISTURE WELL INTO WESTERN KANSAS
THOUGH LATEST ECMWF IS A TAD FURTHER WEST WITH DRY LINE WEDNESDAY
AFTERNOON AND WILL NEED TO MONITOR FOR POSSIBLE STORMS ACROSS THE
FAR SE PLAINS. AS FOR TEMPS...SHOULD SEE HIGHS FALLING BACK TO
AROUND SEASONAL AVERAGES THROUGH THE PERIOD WITH COOLING ALOFT.
FRIDAY-SATURDAY...COOL AND DRY NORTHWEST FLOW PROGGED TO DEVELOP
BEHIND PASSING TROUGH...KEEPING SLIGHT POPS DIURNAL POPS IN PLACE
ACROSS THE HIGH TERRAIN ALONG WITH TEMPERATURES SLIGHTLY BELOW
AVERAGE INTO THE EARLY WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 301 PM MDT SAT MAY 25 2013
VFR CONDITIONS EXPECTED AT TAF SITES WITH BREEZY SOUTH TO SOUTHWEST
WINDS GUSTING TO 25-30 KTS DECREASING TOWARDS 02Z. SHOULD SEE LIGHT
DIURNALLY DRIVEN WINDS OVERNIGHT...WITH BREEZY SOUTHWEST WINDS
RETURNING FOR THE TAF SITES SUNDAY AFTERNOON. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ221-222-225-
227.
RED FLAG WARNING FROM 11 AM TO 9 PM MDT SUNDAY FOR COZ221-222-
225-227-233-237.
&&
$$
SHORT TERM...KT
LONG TERM...MW
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1105 AM MDT SAT MAY 25 2013
.UPDATE...
ISSUED AT 1009 AM MDT SAT MAY 25 2013
WINDS HAVE ALREADY BEEN QUITE GUSTY ACROSS SOUTHERN PORTIONS OF
THE SOUTHEAST PLAINS AND SOME MOUNTAIN AREAS THIS MORNING...AND IS
FORECAST TO SPREAD INTO MOST OF THE LOWER ELEVATIONS BY THIS
AFTERNOON. WHERE FUELS ARE CRITICAL THIS WILL RESULT IN HIGH FIRE
DANGER. MAIN CHANGE TO THE GRIDS WAS TO DROP SFC DEW POINTS ACROSS
THE MTS/I-25 CORRIDOR AS YESTERDAY THEY DROPPED INTO THE SINGLE
DIGITS AND LOWER TEENS AND SEE NO REASON WHY THEY WON`T DO THE
SAME TODAY. HRRR SEEMS TO HAVE LATCHED ON TO THIS WELL AND HAVE
USED THESE GRIDS TO BLEND TOWARDS. SHORT RANGE HIGH RES MODELS
POINT TO BEST POTENTIAL FOR THUNDERSTORMS ALONG THE CO/KS BORDER
DURING THE LATE AFTERNOON. HAVE TRIMMED BACK WESTERN EXTENT OF
POPS TO BETTER REFLECT THIS.
LOOKS LIKE PORTIONS OF EASTERN LAS ANIMAS AND WESTERN BACA COUNTY
COULD SEE AN HOUR OR TWO OF CRITICAL TO NEAR CRITICAL FIRE WEATHER
CONDITIONS THIS AFTERNOON. HOWEVER DRY LINE SHOULD WAVER BACK
WESTWARD INTO BACA COUNTY EARLY THIS EVENING AS CONVECTION FIRES
ALONG THE DRY LINE. WINDS ALSO APPEAR TO SLACKEN OFF SOME ACROSS
EASTERN LAS ANIMAS COUNTY AS THE SFC TROF DEEPENS AND BEST GRADIENT
SHIFTS SOUTH AND EASTWARD. THUS WILL HOLD OFF ON FIRE WEATHER
HIGHLIGHTS FOR THESE AREAS. -KT
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM MDT SAT MAY 25 2013
...HOT...
JULY-LIKE WX EXPECTED TODAY AS DRY SW WINDS ALOFT CONTINUE TO
OVERSPREAD THE AREA...AND PRECIP REMAINS MOSTLY OUTSIDE OUR CWA.
H7 TEMPS RISE ANOTHER DEGREE OR SO...AND AFTER GETTING BURNED BY MX
TEMPS YESTERDAY ACROSS THE PLAINS...WILL NOT MAKE THE SAME MISTAKE
TODAY AND HAVE GONE ON THE HIGH SIDE OF GUIDANCE...GIVING US LOWER
TO MID 90S ACROSS THE PLAINS. FORECAST HIGH OF 95 FOR KPUB THIS
AFTERNOON WOULD BREAK THE OLD RECORD OF 94 FOR THIS DATE.
FIRE WX STILL A CONCERN THRU THIS AFTERNOON. RED FLAG CONDITIONS
LOOK A BIT SPOTTY ACROSS THE AREA TODAY...MAINLY DUE TO MARGINAL
WIND GUSTS...BUT WITH DRY AND VERY WARM CONDITIONS WILL KEEP THE
RED FLAG WARNING GOING AS ISSUED. WITH THE HOLIDAY WEEKEND...IT
WILL BE PARTICULARLY IMPORTANT TO GUARD AGAINST FIRE STARTS THE
NEXT COUPLE DAYS.
THUNDERSTORMS ACROSS THE NM BORDER ARE SLOWLY DIMINISHING THIS
MORNING AND SHOULD WRAP UP BY SUNRISE. THE DRYLINE RETREATS TO THE
KS BORDER THIS AFTERNOON...SO ONLY A SLIGHT THREAT FOR TS
ACTIVITY...MAINLY ALONG AND E OF HGWY 287 THROUGH BACA...PROWERS AND
KIOWA COUNTIES. THERE COULD POTENTIALLY BE A STRONG STORM OR TWO
RIGHT NR THE BORDER BY LATER THIS AFTERNOON. STORMS WILL GRADUALLY
DIMINISH AFTER SUNSET. WILL BE A RATHER MILD NIGHT AS TEMPS ALOFT
STAY RATHER HIGH...AND S-SW WINDS ARE SLOW TO DIMINISH THROUGH THE
NIGHT...PARTICULARLY OVER THE FAR ERN COUNTIES. ROSE
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM MDT SAT MAY 25 2013
.SUNDAY AND MONDAY...DRY AND WARM SOUTHWEST FLOW ALOFT CONTINUES
OVER THE REGION AHEAD OF THE TROUGH OVER THE PACIFIC NORTHWEST.
DRY LINE MAY MOVE WEST OF THE KANSAS BORDER DURING THE NIGHT...BUT
IT WILL MOVE EAST OF THE KANSAS BORDER DURING THE DAY. HAVE
ISSUED A FIRE WEATHER WATCH FOR SUNDAY FOR ALL REGIONS OF THE CWA
WITH CRITICAL FUELS. THERE WILL NOT BE MUCH OF A PROBLEM REACHING
THE RELATIVE HUMIDITY CRITERIA AS MINIMUM HUMIDITIES ARE MOSTLY IN
THE SINGLE DIGITS. WINDS ARE MORE OF A CONCERN...BUT THERE SHOULD
BE FREQUENT GUSTS ABOVE 25 MPH ON SUNDAY. ON MONDAY...WINDS MAY BE
LIGHTER...ESPECIALLY OVER THE NORTHERN SECTIONS. WOULD NOT BE
SURPRISED LATER SHIFTS ISSUE FIRE WEATHER WATCHES FOR MONDAY FOR
PARTS OF THE REGION. GRIDS ONLY HAVE SILENT POPS FOR BOTH DAYS
GIVEN DRY AIRMASS OVER THE REGION.
.TUESDAY...UPPER TROUGH WILL START APPROACHING COLORADO. MID
LEVEL MOISTURE WILL MOVE INTO CENTRAL COLORADO...WITH A CHANCE FOR
SOME AFTERNOON THUNDERSTORMS OVER THE CENTRAL MOUNTAINS. DRY
SOUTHWEST FLOW MAY CONTINUE OVER THE EASTERN TWO THIRDS OF THE
CWA. SOME FIRE WEATHER HIGHLIGHTS MAY EVENTUALLY BE NEEDED FOR
PORTIONS OF THE CWA ON TUESDAY.
.WEDNESDAY THROUGH FRIDAY...EC AND GFS CONTINUE TO DISAGREE ON THE
SPEED AND TRAJECTORY OF THE STRONGER UPPER TROUGH. EC HAS
CONSISTENTLY BEEN MORE AMPLIFIED AND SLOWER WITH THE TROUGH. THE
EC SOLUTION COULD ALLOW FOR SOME LOW LEVEL MOISTURE TO ADVECT INTO
EASTERN COLORADO RESULTING IN PRECIPITATION OVER MUCH OF THE
REGION WEDNESDAY. THE GFS IS FASTER AND FURTHER NORTH...KEEPING
WESTERLY WINDS OVER MUCH OF THE REGION. THE GFS SOLUTION WOULD
ONLY PRODUCE LIGHT RAIN...IF ANY...FOR MUCH OF THE REGION. A FEW
ENSEMBLE MEMBERS SUPPORT THE EC SOLUTION...BUT A MAJORITY FOLLOW
THE OPERATIONAL GFS. GEM ALSO FOLLOWS GFS SOLUTION. WHILE MAJORITY
OF GUIDANCE FOLLOWS GFS...AM NOT DISMISSING EC SOLUTION YET GIVEN
EC PAST TRACK RECORD.
.THURSDAY AND FRIDAY...MODELS AGREE WITH UPPER LOW DEVELOPING OVER
THE NORTHERN ROCKIES...THEN MOVING EASTWARD INTO THE NORTHERN
PLAINS. THIS PATTERN WOULD CONFINE PRECIPITATION MOSTLY TO
NORTHERN AND CENTRAL COLORADO MOUNTAINS. TEMPERATURES WILL BE
COOLER DUE TO COOLER AIR ALOFT...BUT WESTERLY FLOW WOULD LIMIT ANY
PRECIPITATION TO LIGHT SHOWERS. --PGW--
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1104 AM MDT SAT MAY 25 2013
VFR CONDITIONS EXPECTED AT TAF SITES WITH GUSTY SOUTH TO SOUTHWEST
WINDS EXPECTED TO INCREASE FOR ALL THREE LOCATIONS DURING THE
AFTERNOON. GUSTS TO 25KTS WILL BE POSSIBLE...WITH HIGHER GUSTS TO
AROUND 30-35 KTS POSSIBLE OVER/NEAR THE MOUNTAINS THROUGH THE
AFTERNOON. WINDS SHOULD DECREASE AROUND 02Z...WITH LIGHT DRAINAGE
WINDS EXPECTED OVERNIGHT. ISOLATED -TSRA WILL BE POSSIBLE LATE
THIS AFTERNOON THROUGH THIS EVENING ALONG THE CO/KS BORDER.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ221-222-225-
227.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING
FOR COZ221-222-225-227-233-237.
&&
$$
UPDATE...KT
SHORT TERM...ROSE
LONG TERM...PGW
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1022 AM MDT SAT MAY 25 2013
.UPDATE...
ISSUED AT 1009 AM MDT SAT MAY 25 2013
WINDS HAVE ALREADY BEEN QUITE GUSTY ACROSS SOUTHERN PORTIONS OF
THE SOUTHEAST PLAINS AND SOME MOUNTAIN AREAS THIS MORNING...AND IS
FORECAST TO SPREAD INTO MOST OF THE LOWER ELEVATIONS BY THIS
AFTERNOON. WHERE FUELS ARE CRITICAL THIS WILL RESULT IN HIGH FIRE
DANGER. MAIN CHANGE TO THE GRIDS WAS TO DROP SFC DEW POINTS ACROSS
THE MTS/I-25 CORRIDOR AS YESTERDAY THEY DROPPED INTO THE SINGLE
DIGITS AND LOWER TEENS AND SEE NO REASON WHY THEY WON`T DO THE
SAME TODAY. HRRR SEEMS TO HAVE LATCHED ON TO THIS WELL AND HAVE
USED THESE GRIDS TO BLEND TOWARDS. SHORT RANGE HIGH RES MODELS
POINT TO BEST POTENTIAL FOR THUNDERSTORMS ALONG THE CO/KS BORDER
DURING THE LATE AFTERNOON. HAVE TRIMMED BACK WESTERN EXTENT OF
POPS TO BETTER REFLECT THIS.
LOOKS LIKE PORTIONS OF EASTERN LAS ANIMAS AND WESTERN BACA COUNTY
COULD SEE AN HOUR OR TWO OF CRITICAL TO NEAR CRITICAL FIRE WEATHER
CONDITIONS THIS AFTERNOON. HOWEVER DRY LINE SHOULD WAVER BACK
WESTWARD INTO BACA COUNTY EARLY THIS EVENING AS CONVECTION FIRES
ALONG THE DRY LINE. WINDS ALSO APPEAR TO SLACKEN OFF SOME ACROSS
EASTERN LAS ANIMAS COUNTY AS THE SFC TROF DEEPENS AND BEST GRADIENT
SHIFTS SOUTH AND EASTWARD. THUS WILL HOLD OFF ON FIRE WEATHER
HIGHLIGHTS FOR THESE AREAS. -KT
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM MDT SAT MAY 25 2013
...HOT...
JULY-LIKE WX EXPECTED TODAY AS DRY SW WINDS ALOFT CONTINUE TO
OVERSPREAD THE AREA...AND PRECIP REMAINS MOSTLY OUTSIDE OUR CWA.
H7 TEMPS RISE ANOTHER DEGREE OR SO...AND AFTER GETTING BURNED BY MX
TEMPS YESTERDAY ACROSS THE PLAINS...WILL NOT MAKE THE SAME MISTAKE
TODAY AND HAVE GONE ON THE HIGH SIDE OF GUIDANCE...GIVING US LOWER
TO MID 90S ACROSS THE PLAINS. FORECAST HIGH OF 95 FOR KPUB THIS
AFTERNOON WOULD BREAK THE OLD RECORD OF 94 FOR THIS DATE.
FIRE WX STILL A CONCERN THRU THIS AFTERNOON. RED FLAG CONDITIONS
LOOK A BIT SPOTTY ACROSS THE AREA TODAY...MAINLY DUE TO MARGINAL
WIND GUSTS...BUT WITH DRY AND VERY WARM CONDITIONS WILL KEEP THE
RED FLAG WARNING GOING AS ISSUED. WITH THE HOLIDAY WEEKEND...IT
WILL BE PARTICULARLY IMPORTANT TO GUARD AGAINST FIRE STARTS THE
NEXT COUPLE DAYS.
THUNDERSTORMS ACROSS THE NM BORDER ARE SLOWLY DIMINISHING THIS
MORNING AND SHOULD WRAP UP BY SUNRISE. THE DRYLINE RETREATS TO THE
KS BORDER THIS AFTERNOON...SO ONLY A SLIGHT THREAT FOR TS
ACTIVITY...MAINLY ALONG AND E OF HGWY 287 THROUGH BACA...PROWERS AND
KIOWA COUNTIES. THERE COULD POTENTIALLY BE A STRONG STORM OR TWO
RIGHT NR THE BORDER BY LATER THIS AFTERNOON. STORMS WILL GRADUALLY
DIMINISH AFTER SUNSET. WILL BE A RATHER MILD NIGHT AS TEMPS ALOFT
STAY RATHER HIGH...AND S-SW WINDS ARE SLOW TO DIMINISH THROUGH THE
NIGHT...PARTICULARLY OVER THE FAR ERN COUNTIES. ROSE
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM MDT SAT MAY 25 2013
.SUNDAY AND MONDAY...DRY AND WARM SOUTHWEST FLOW ALOFT CONTINUES
OVER THE REGION AHEAD OF THE TROUGH OVER THE PACIFIC NORTHWEST.
DRY LINE MAY MOVE WEST OF THE KANSAS BORDER DURING THE NIGHT...BUT
IT WILL MOVE EAST OF THE KANSAS BORDER DURING THE DAY. HAVE
ISSUED A FIRE WEATHER WATCH FOR SUNDAY FOR ALL REGIONS OF THE CWA
WITH CRITICAL FUELS. THERE WILL NOT BE MUCH OF A PROBLEM REACHING
THE RELATIVE HUMIDITY CRITERIA AS MINIMUM HUMIDITIES ARE MOSTLY IN
THE SINGLE DIGITS. WINDS ARE MORE OF A CONCERN...BUT THERE SHOULD
BE FREQUENT GUSTS ABOVE 25 MPH ON SUNDAY. ON MONDAY...WINDS MAY BE
LIGHTER...ESPECIALLY OVER THE NORTHERN SECTIONS. WOULD NOT BE
SURPRISED LATER SHIFTS ISSUE FIRE WEATHER WATCHES FOR MONDAY FOR
PARTS OF THE REGION. GRIDS ONLY HAVE SILENT POPS FOR BOTH DAYS
GIVEN DRY AIRMASS OVER THE REGION.
.TUESDAY...UPPER TROUGH WILL START APPROACHING COLORADO. MID
LEVEL MOISTURE WILL MOVE INTO CENTRAL COLORADO...WITH A CHANCE FOR
SOME AFTERNOON THUNDERSTORMS OVER THE CENTRAL MOUNTAINS. DRY
SOUTHWEST FLOW MAY CONTINUE OVER THE EASTERN TWO THIRDS OF THE
CWA. SOME FIRE WEATHER HIGHLIGHTS MAY EVENTUALLY BE NEEDED FOR
PORTIONS OF THE CWA ON TUESDAY.
.WEDNESDAY THROUGH FRIDAY...EC AND GFS CONTINUE TO DISAGREE ON THE
SPEED AND TRAJECTORY OF THE STRONGER UPPER TROUGH. EC HAS
CONSISTENTLY BEEN MORE AMPLIFIED AND SLOWER WITH THE TROUGH. THE
EC SOLUTION COULD ALLOW FOR SOME LOW LEVEL MOISTURE TO ADVECT INTO
EASTERN COLORADO RESULTING IN PRECIPITATION OVER MUCH OF THE
REGION WEDNESDAY. THE GFS IS FASTER AND FURTHER NORTH...KEEPING
WESTERLY WINDS OVER MUCH OF THE REGION. THE GFS SOLUTION WOULD
ONLY PRODUCE LIGHT RAIN...IF ANY...FOR MUCH OF THE REGION. A FEW
ENSEMBLE MEMBERS SUPPORT THE EC SOLUTION...BUT A MAJORITY FOLLOW
THE OPERATIONAL GFS. GEM ALSO FOLLOWS GFS SOLUTION. WHILE MAJORITY
OF GUIDANCE FOLLOWS GFS...AM NOT DISMISSING EC SOLUTION YET GIVEN
EC PAST TRACK RECORD.
.THURSDAY AND FRIDAY...MODELS AGREE WITH UPPER LOW DEVELOPING OVER
THE NORTHERN ROCKIES...THEN MOVING EASTWARD INTO THE NORTHERN
PLAINS. THIS PATTERN WOULD CONFINE PRECIPITATION MOSTLY TO
NORTHERN AND CENTRAL COLORADO MOUNTAINS. TEMPERATURES WILL BE
COOLER DUE TO COOLER AIR ALOFT...BUT WESTERLY FLOW WOULD LIMIT ANY
PRECIPITATION TO LIGHT SHOWERS. --PGW--
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 440 AM MDT SAT MAY 25 2013
VFR CONDITIONS EXPECTED FOR THE TAF SITES NEXT 24 H. STORMS WILL BE
CONFINED TO NEAR THE KS BORDER LATE THIS AFTERNOON...BUT A COUPLE
COULD BE ON THE STRONG SIDE WITH SOME HAIL. WINDS WILL ALSO BE A BIT
GUSTY FROM THE S TO SW OVR THE ERN CO PLAINS. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ221-222-225-
227.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING
FOR COZ221-222-225-227-233-237.
&&
$$
UPDATE...KT
SHORT TERM...ROSE
LONG TERM...PGW
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS MIAMI FL
236 PM EDT SAT MAY 25 2013
.SHORT TERM (TONIGHT-MONDAY NIGHT)...
PLENTY OF DRY AIR ALONG WITH RISING UPPER HEIGHTS IN THE WAKE OF THE
FRONTAL BOUNDARY THAT PASSED THROUGH TODAY WILL LEAD TO MORE OF A
SUPPRESSED ENVIRONMENT THROUGH THE REMAINDER OF THE WEEKEND. MODEL
TIME HEIGHTS/SOUNDINGS AROUND THE LOCAL AREA REFLECT THIS AND
GENERALLY INDICATE MOST OF THE MOISTURE REMAINING CONFINED WITHIN
THE LOWER 4 KFT UNDERNEATH A STRONG SUBSIDENCE INVERSION.
PRECIPITABLE WATER VALUES ARE FORECAST TO STEADILY DROP TONIGHT AND
BOTTOM OUT JUST ABOVE HALF OF AN INCH SUNDAY BEFORE STEADILY
TRENDING BACK UP INTO THE UPCOMING WEEK. HOWEVER...MODERATE
NORTHEASTERLY WINDS AND PLENTY OF LOW-LEVEL MOISTURE MAY ALLOW FOR A
FEW SHALLOW BRIEF SHOWERS TO DEVELOP OVER THE ADJACENT ATLANTIC
WATERS AND SPREAD ASHORE THROUGH THE REMAINDER OF THE
WEEKEND...ESPECIALLY THROUGH THE OVERNIGHT AND EARLY MORNING HOURS.
THIS LINES UP WELL WITH THE LATEST WRF SOLUTIONS...WHICH INDICATE A
FEW LIGHT SHOWERS DEVELOPING AND SPREADING ASHORE OVER THE NORTHERN
AREAS LATER TONIGHT INTO SUNDAY. ON MONDAY...DEEP EASTERLY FLOW UP
TO AROUND 18 KFT ALONG WITH INCREASING MOISTURE MAY LEAD TO FEW
SHOWERS DEVELOPING INLAND AND TOWARD THE GULF COAST AREAS THROUGH
THE AFTERNOON/EVENING HOURS. HOWEVER...IN THE ABSENCE OF A GULF
COAST SEA BREEZE DUE TO THE MODERATE EASTERLY FLOW IN PLACE ALONG
WITH THE MID-LEVEL DRY AIR...MAINLY BRIEF SHOWERS WILL BE
ANTICIPATED. ALONG THE EAST COAST...TEMPERATURES WILL REMAIN
SLIGHTLY BELOW NORMAL EACH DAY. 85/AG
.LONG TERM (TUESDAY-FRIDAY)...
ADDITIONAL MOISTURE IS FORECAST TO ENTER THE REGION EARLY NEXT WEEK
AS A MID TO UPPER LEVEL TROUGH IS FORECAST TO DEEPEN IN THE EASTERN
GULF WITH A CHANCE OF SHOWERS AND THUNDERSTORMS RETURNING TO THE
REGION. THERE IS SOME CONSENSUS AMONGST THE MODEL GUIDANCE THAT
DEEPER LAYERED TROPICAL MOISTURE AND A DEEPENING OF THE MID TO UPPER
LEVEL TROUGH COULD OCCUR AROUND MID-WEEK AND PERSIST FOR A COUPLE OF
DAYS WITH MORE WIDESPREAD CONVECTION POSSIBLE. WILL HAVE TO WAIT AND
SEE IF FUTURE GUIDANCE PERSISTS WITH THESE SYNOPTIC FEATURES.
BD
&&
.AVIATION...
EASTERLY FLOW WILL PREVAIL THROUGH THE REMAINDER OF THE AFTERNOON
ACROSS THE SOUTH FLORIDA AREA WITH VFR CONDITIONS. A FEW SHOWERS
HAVE DEVELOPED THIS AFTERNOON ACROSS EXTREME SOUTHERN MAINLAND
MONROE COUNTY. THE LATEST HRRR DEPICTS A FEW MORE SHOWERS DEVELOPING
ACROSS THIS AREA AND IN COLLIER COUNTY OVER THE NEXT FEW
HOURS...POSSIBLY AFFECTING KAPF. BELIEVE THE SHOWER COVERAGE WILL BE
SPARSE AND DID NOT CARRY ANY MENTION FOR THE KAPF TAF. EASTERLY FLOW
SHOULD CONTINUE OVERNIGHT AT AROUND 10 KNOTS AT ALL TAF SITES BEFORE
BECOMING GUSTY AGAIN TOMORROW.
&&
.MARINE...
WINDS AND SEAS WILL QUICKLY INCREASE THROUGH THE REMAINDER OF THE
WEEKEND IN THE WAKE OF A WEAK FRONTAL BOUNDARY AS HIGH
PRESSURE BUILDS OVER THE REGION. ALTHOUGH ADVISORY LEVEL WINDS AND
SEAS ARE NOT ANTICIPATED AT THIS TIME...MARINERS OPERATING SMALL
CRAFT ARE ENCOURAGED TO EXERCISE CAUTION...MAINLY OVER THE ATLANTIC
WATERS THIS WEEKEND.
AT THE EAST COAST BEACHES...STRONG RIP CURRENTS WILL BE LIKELY BY
SUNDAY DUE TO MODERATE ONSHORE WINDS AND BUILDING SURF.
&&
.FIRE WEATHER...
DESPITE THE DRIER AIR THAT IS FORECAST TO SPREAD OVER THE AREA
THROUGH THE REMAINDER OF THE WEEKEND AND INTO THE UPCOMING
WEEK...RELATIVE HUMIDITIES ARE FORECAST TO REMAIN ABOVE CRITICAL
LEVELS EACH DAY. EASTERLY WINDS WILL BECOME GUSTY THROUGH THE
AFTERNOON PERIODS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 72 82 73 83 / - 10 10 10
FORT LAUDERDALE 76 85 77 86 / - 10 20 10
MIAMI 75 84 75 85 / - 10 20 20
NAPLES 69 91 69 91 / - 10 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT-TERM DISCUSSION/MARINE/FIRE...85/AG
LONG-TERM DISCUSSION...BD
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS LINCOLN IL
315 PM CDT SAT MAY 25 2013
.DISCUSSION...
ISSUED 253 PM CDT SAT MAY 25 2013
HIGH PRESSURE RIDGE JUST TO THE EAST NOT QUITE STRONG ENOUGH TO
DAMPEN LEFTOVER MCS ACTIVITY MOVING INTO CENTRAL ILLINOIS THIS
AFTERNOON. WIDESPREAD SHOWERS AND ISOLATED THUNDER THROUGHOUT THE
EARLY AFTERNOON HOURS SLOWLY LOSING ITS STRENGTH AND THUNDER.
CLEARING SLOWLY MOVING TO THE EAST...THOUGH PLENTY OF -RA AND
SPRINKLES LIKELY. 4KM WRF DOING A FAIR JOB...IF NOT A FEW HOURS
BEHIND SCHEDULE. EXTRAPOLATING THE ERROR WOULD GIVE A BRIEF BREAK
WITH MORE SCATTERED ACTIVITY BEFORE THE NEXT ROUND. TODAYS WEATHER
EXPECTED TO CONTINUE THROUGH MONDAY BEFORE SLOWING ON TUESDAY.
MODELS IN PRETTY DECENT AGREEMENT THROUGH MID WEEK BEFORE
DIVERGING ON THE HANDLING OF THE UPPER WAVE PATTERN WITH THE TROF
OVER THE ERN HALF OF THE CONUS...AND ITS MOVEMENT AND TILT AS IT
PUSHES THE UPPER RIDGE OUT OF THE MIDWEST. TIMING ET AL IN
COMPLETE DISAGREEMENT BEYOND FH120.
SHORT TERM...TONIGHT THROUGH MONDAY...
PERIODIC SHOWERS AND THUNDERSTORMS LIKELY THROUGH MONDAY. WARM AIR
BUILDING UNDER THE RIDGE OVER THE PLAINS...AND A FRONT
DELINEATING THE BOUNDARY BETWEEN THE WARMER AIR TO THE SW AND THE
COOLER AIR OVER THE REGION ALMOST QUASI STATIONARY ALONG THE MISS
RIVER VALLEY FOR THE REMAINDER OF THE HOLIDAY WEEKEND. A SERIES
OF SHORT WAVES TOPPING THE RIDGE AND DIVING INTO ILX WILL KEEP THE
POPS IN PLACE THROUGH THE HOLIDAY WEEKEND. TEMPS CONTINUE TO
REMAIN MILD...EVEN THOUGH WARMING A COUPLE DEGREES EACH DAY...UNTIL THE
WARM FRONT FINALLY PASSES THROUGH THE AREA MON NIGHT/TUESDAY.
LONG TERM...TUESDAY THROUGH FRIDAY...
WARM FRONT LIFTING THROUGH THE REGION MON NIGHT AS THE ERN EDGE OF
THE RIDGE BREAKS DOWN AND PLENTY OF WARM AIR MOVES IN AT
MIDLEVELS. PRECIP SLOWLY REDUCING IN COVERAGE AND MUCH WARMER INTO
THE WORK WEEK. WESTERN TROF DIGS IN...AMPLIFYING THE WAVE PATTERN
OVER THE CONUS AND LEAVING THE UPPER MIDWEST IN SWRLY FLOW...AND
MUCH OF IL IN WEAK FLOW...IF ANY...UNDER THE BUILDING RIDGE. VERY
WARM MIDLEVELS AND THE GUIDANCE STILL BEING PULLED DOWN A BIT BY
CLIMATOLOGY INFLUENCE. HAVE BOOSTED TEMPS TO COMPENSATE...STILL MAY NOT BE
ENOUGH. RETURNING POPS ON THURS NIGHT/FRI GETTING DELAYED A BIT
MORE IN THIS RUN....AND STILL VERY MUCH IN DEBATE AS THE GFS AND
ECMWF DIVERGE QUITE A BIT WITH THE PROGRESSION OF THE WAVE PATTERN
AT DAY 7/8.
HJS
&&
.AVIATION...
ISSUED 1243 PM CDT SAT MAY 25 2013
LARGE RAIN SHIELD HAS OVERSPREAD THE CENTRAL ILLINOIS TAF SITES AT
MIDDAY. THUNDER HAS BEEN ON THE WANE...AND HAVE REMOVED THUNDER AT
ALL SITES BY ABOUT 21-22Z. HAVE SEEN SOME MVFR VISIBILITIES AT
TIMES IN THE HEAVIER SHOWERS...BUT CEILINGS WILL REMAIN FAIRLY
HIGH. MAIN QUESTION LATER ON IS WITH REDEVELOPMENT OF NOCTURNAL
CONVECTION TO THE NORTHWEST. MOST MODELS FAVOR IT DEVELOPING IN
IOWA SIMILAR TO LAST NIGHT THEN MOVING SOUTHEAST...ALTHOUGH THE
LATEST RAP MODEL IS INDICATING NORTHEAST MISSOURI AND WESTERN
ILLINOIS FOR INITIATION. HAVE MADE LITTLE CHANGE TO EARLIER TAFS
IN REGARDS TO THIS...ASIDE FROM MINOR TIMING ADJUSTMENTS...FAVORING
RAIN AND VCTS MENTIONS WHILE THE POTENTIAL CONTINUES TO BE
EVALUATED OVER THE NEXT FEW HOURS. HAVE TRIED TO INDICATE A FEW
HOURS OF DRIER CONDITIONS LATE IN THE PERIOD...BUT CONFIDENCE IS
LOW AT THIS TIME DUE TO THE EARLIER QUESTION OF OVERNIGHT CONVECTION.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1243 PM CDT SAT MAY 25 2013
.DISCUSSION...
ISSUED 1011 AM CDT SAT MAY 25 2013
OVERNIGHT MCS FROM IOWA HAS BEEN SHOWING SOME WARMING CLOUD TOPS
AS IT DROPS SOUTHEAST INTO WESTERN ILLINOIS. HAVE BEEN SEEING SOME
LIGHT ECHOES ON RADAR AS FAR EAST AS THE INDIANA BORDER...BUT THE
AIR MASS OVER CENTRAL ILLINOIS IS VERY DRY AS EVIDENCED BY THE
MORNING SOUNDING AND LAPS ANALYSIS...SO A LOT OF THIS HAS BEEN
ALOFT. FINALLY SEEING SOME MEASURABLE RAIN AROUND GALESBURG
THOUGH. RAP AND HRRR MODELS DOING A REASONABLE JOB WITH THE MCS
ITSELF...AND SHOW THE RAIN MOST WIDESPREAD THROUGH EARLY AFTERNOON
BEFORE BREAKING UP. MOST OF THE THUNDERSTORMS HAVE BEEN DROPPING
SOUTHEASTWARD TOWARD WEST CENTRAL ILLINOIS...SO HAVE CUT BACK SOME
ON THE THUNDER CHANCES...ESPECIALLY NORTH OF I-74. HAVE SENT OUT
SOME UPDATES TO SIGNIFICANTLY INCREASE THE RAIN CHANCES ACROSS THE
NORTHWEST HALF OF THE CWA...WITH LESSER CHANGES NEEDED ACROSS THE
SOUTHEAST.
GEELHART
&&
.AVIATION...
ISSUED 1243 PM CDT SAT MAY 25 2013
LARGE RAIN SHIELD HAS OVERSPREAD THE CENTRAL ILLINOIS TAF SITES AT
MIDDAY. THUNDER HAS BEEN ON THE WANE...AND HAVE REMOVED THUNDER AT
ALL SITES BY ABOUT 21-22Z. HAVE SEEN SOME MVFR VISIBILITIES AT
TIMES IN THE HEAVIER SHOWERS...BUT CEILINGS WILL REMAIN FAIRLY
HIGH. MAIN QUESTION LATER ON IS WITH REDEVELOPMENT OF NOCTURNAL
CONVECTION TO THE NORTHWEST. MOST MODELS FAVOR IT DEVELOPING IN
IOWA SIMILAR TO LAST NIGHT THEN MOVING SOUTHEAST...ALTHOUGH THE
LATEST RAP MODEL IS INDICATING NORTHEAST MISSOURI AND WESTERN
ILLINOIS FOR INITIATION. HAVE MADE LITTLE CHANGE TO EARLIER TAFS
IN REGARDS TO THIS...ASIDE FROM MINOR TIMING ADJUSTMENTS...FAVORING
RAIN AND VCTS MENTIONS WHILE THE POTENTIAL CONTINUES TO BE
EVALUATED OVER THE NEXT FEW HOURS. HAVE TRIED TO INDICATE A FEW
HOURS OF DRIER CONDITIONS LATE IN THE PERIOD...BUT CONFIDENCE IS
LOW AT THIS TIME DUE TO THE EARLIER QUESTION OF OVERNIGHT CONVECTION.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 242 AM CDT SAT MAY 25 2013
UNSETTLED WEATHER THROUGH THE MEMORIAL DAY WEEKEND...FOLLOWED BY
MUCH WARMER/DRIER CONDITIONS FOR THE MIDDLE AND END OF NEXT WEEK.
SHORT TERM...TODAY THROUGH MONDAY
CONVECTION CURRENTLY DEVELOPING ALONG THE NOSE OF A 45-50KT LLJ
OVER NEBRASKA IS EXPECTED TO TRACK E/SE INTO THE AREA TODAY. MAIN
QUESTION WILL BE HOW FAR EAST THE PRECIP CAN PENETRATE INTO
SPRAWLING SURFACE RIDGE AXIS EXTENDING FROM THE GREAT LAKES TO THE
GULF COAST. 00Z KILX UPPER AIR SOUNDING SHOWED A VERY DRY PROFILE
FROM THE SURFACE UP TO ABOUT 500MB. ANY PRECIP MOVING INTO THIS
HOSTILE ENVIRONMENT WILL INITIALLY EVAPORATE UNTIL THE AIRMASS IS
SUFFICIENTLY MOISTENED. DUE TO THE CONTINUED DRY E/NE LOW-LEVEL
FLOW...HAVE REMOVED POPS ACROSS EAST-CENTRAL AND SOUTHEAST
ILLINOIS FOR THE MORNING HOURS. FURTHER WEST...HIGH-RES HRRR
SUGGESTS NEBRASKA CONVECTION WILL EVENTUALLY SPREAD INTO
WEST-CENTRAL ILLINOIS TOWARD MIDDAY. WILL THEREFORE CARRY CHANCE
POPS DURING THE MORNING...THEN LIKELY THIS AFTERNOON FOR LOCATIONS
ALONG/WEST OF I-55.
INITIAL AREA OF CONVECTION WILL DISSIPATE AS IT MOVES INTO
EAST-CENTRAL ILLINOIS LATER THIS AFTERNOON AND EVENING.
MEANWHILE...LOW-LEVEL JET WILL ONCE AGAIN STRENGTHEN AND FOCUS A
RENEWED ROUND OF SHOWERS/THUNDER UPSTREAM ACROSS IOWA TONIGHT.
THIS ACTIVITY IS THEN EXPECTED TO TRACK E/SE INTO CENTRAL ILLINOIS
LATE TONIGHT INTO SUNDAY. WITH AIRMASS MOISTENED FROM INITIAL
PRECIP TODAY...THINK RAIN CHANCES WILL BE HIGHER ACROSS THE BOARD
TONIGHT/SUNDAY. WILL THEREFORE CARRY LIKELY POPS EVERYWHERE EXCEPT
THE FAR SE CWA.
ADDITIONAL SHOWERS/STORMS WILL FIRE ON MONDAY...AS PERSISTENT
FRONTAL BOUNDARY FINALLY BEGINS TO SHIFT SLOWLY NORTHWARD ACROSS
THE AREA. WILL CONTINUE TO HIT POPS HARD...ESPECIALLY ACROSS THE
CENTRAL AND NORTHERN ZONES. TOTAL RAINFALL FROM THIS MULTI-DAY
EVENT WILL BE LIGHTEST ALONG THE ILLINOIS/INDIANA BORDER WHERE
AMOUNTS OF ONE HALF TO ONE INCH WILL BE COMMON. HIGHER RAIN TOTALS
WILL BE FOCUSED FURTHER WEST...ESPECIALLY WEST OF I-55 WHERE ONE
AND A HALF TO TWO INCHES WILL BE LIKELY.
LONG TERM...TUESDAY THROUGH FRIDAY
AS UPPER TROUGH DIGS OVER THE WESTERN CONUS...DOWNSTREAM RIDGE
WILL BUILD ACROSS THE MIDWEST/OHIO RIVER VALLEY. THIS WILL FINALLY
GIVE THE SURFACE FRONT A GOOD PUSH NORTHWARD BY TUESDAY...RESULTING
IN LOWER POPS AND HIGHER TEMPS. WILL ONLY CARRY LOW CHANCE POPS
ACROSS THE FAR NORTHERN CWA...WHILE HIGH TEMPS CLIMB INTO THE
LOWER TO MIDDLE 80S. AFTER THAT...MODEL SOLUTIONS VARY SOMEWHAT
CONCERNING HOW QUICKLY THE UPPER RIDGE EVENTUALLY BREAKS DOWN.
GIVEN AMPLIFIED PATTERN...THINK THIS WILL BE LATER RATHER THAN
SOONER...SO HAVE GONE WITH A VERY WARM AND DRY FORECAST THROUGH
THURSDAY. WEAKENING FRONTAL BOUNDARY MAY PUSH INTO THE REGION BY
THE END OF THE WEEK...SO HAVE INCLUDED CHANCE FOR SHOWERS/THUNDER
ON FRIDAY WITH CONTINUED WARM TEMPS WELL INTO THE 80S.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
125 PM EDT SAT MAY 25 2013
.AVIATION...
//DISCUSSION...
DRY AND STABLE CONDITIONS WILL EXIST THROUGH THE TAF PERIOD AS HIGH
PRESSURE REMAINS CONTROL. RIDGE POSITIONING WILL FAVOR A LIGHT
NORTHERLY WIND COMPONENT. FEW DIURNAL CU WILL QUICKLY DISSIPATE
WITH THE LOSS OF HEATING. SE MICHIGAN WILL REMAIN ALONG THE
EASTERN FRINGE OF A THICKER MID LEVEL CLOUD DECK WITH A BRIEF PERIOD
OF BKN CIRRUS POSSIBLE THROUGH THE LATTER HALF OF THE DAY.
//DTW THRESHOLD THREATS...
* NONE.
&&
.PREV DISCUSSION...ISSUED 325 AM EDT SAT MAY 25 2013
SHORT TERM...TODAY AND TONIGHT
EARLY MORNING MSAS ANALYSIS IS SHOWING A SURFACE RIDGE EXTENDING
SOUTHWARD THROUGH THE LAKE SUPERIOR/MICHIGAN/HURON BASINS. THE BEST
SURFACE RIDGING COMPONENT INSIDE OF THE CWA IS ACROSS THE NORTHERN
THUMB DOWN INTO PORT HURON. PERUSING THROUGH THE SURFACE
OBSERVATIONS...FEELING IS THE BEST POTENTIAL FOR ANY FROST FORMATION
WILL BE IN THE THUMB AND LOW LYING AREAS OF THE GLACIAL TERRAIN WITH
THE LOCAL OFFICE TEMPERATURE AT 33 DEGREES AS OF 230 AM LDT. WILL
MAINTAIN THE FROST ADVISORY AS IS FOR SIMPLICITY.
THERE HAS BEEN A DECENT RADAR PRESENTATION OVERNIGHT ACROSS PORTIONS
OF MN/WI/IA TIED TO THE AGEOSTROPHIC RESPONSE OF MERGING AND
SHEARING OF SHORTWAVE ENERGY. ONE HR PRECIPITATION AMOUNTS HAVE BEEN
LESSENING AS THE PRECIPITATION/VIRGA PUSHES FARTHER TO THE SOUTHEAST.
THIS IS LIKELY IN RESPONSE TO INCREASING CONFLUENCE ALOFT AS THE
ENTRANCE REGION LIES DIRECTLY OVER LOWER MICHIGAN. THE BEST UPPER
LEVEL FORCING IN THE FORM OF 700-500MB FRONTOGENESIS WILL BRUSH FAR
SOUTHWESTERN SECTIONS OF THE STATE BETWEEN 12-15Z...BEFORE PASSING
HARMLESSLY TO THE SOUTH. THE AMOUNT OF AMBIENT DRY AIR IN THE LOWEST
12 KFT AGL SUPPORTS VIRTUALLY NO PRECIPITATION POTENTIAL TODAY. THE
PREFERENCE REGARDING HIGH CLOUD PROG LIES WITH THE 25.05Z RUC WHICH
BRINGS HIGH CLOUDS INTO THE SOUTHWESTERN 2/3RDS OF THE CWA BETWEEN
9-16Z THIS MORNING. INCREASED INSOLATION WITH SOME MODERATION OF THE
AIRMASS WILL SUPPORT A SOLID 3-8F DEGREE UPTICK IN HIGH TEMPERATURES.
EXPECT READINGS TO RANGE FROM THE MIDDLE 50S IN THE FAR NORTHERN
THUMB/LAKE HURON SHORELINE TO THE MIDDLE 60S DETROIT SOUTHWARD.
SURFACE HIGH PRESSURE WILL EXPAND ACROSS THE CENTRAL GREAT LAKES
TONIGHT...BRINGING THE PROSPECTS OF ANOTHER COOL TO COLD NIGHT.
DIFFERENTIAL AIRMASS RECOVERY SHOULD BE GOOD FOR A FEW DEGREES OFF
THIS MORNINGS MINS. WORKED WITH A BLEND OF UNDERCUT GUIDANCE WITH
SOME PERSISTENCE. EXPECTED LOWS TONIGHT SHOULD RANGE FROM THE LOWER
TO MIDDLE 30S IN THE THUMB TO LOWER 40S SOUTHEAST OF THE TERRAIN.
LONG TERM...SUNDAY THROUGH FRIDAY
LOWER MICHIGAN WILL RESIDE BETWEEN A HIGH AMPLITUDE RIDGE ACROSS THE
UPPER MIDWEST AND A DEEP UPPER LOW LIFTING FROM NEW ENGLAND INTO THE
CANADIAN MARITIMES DURING THE LATER HALF OF THE WEEKEND...SUSTAINING
A CONFLUENT FLOW ALOFT. AT THE SFC...THIS WILL TRANSLATE TO HIGH
PRESSURE BUILDING FROM THE UPPER GREAT LAKES ON SUNDAY TO THE
EASTERN GREAT LAKES ON MONDAY. OTHER THAN THE POTENTIAL FOR SOME
HIGH CLOUDS...SKIES SHOULD REMAIN MAINLY CLEAR WITH VERY DRY AIR
OVERHEAD. TEMPS WILL SLOWLY MODERATE...LEADING TO AN OVERALL WARMING
TREND HEADING INTO MEMORIAL DAY. EXPECT MIXING DEPTHS MAY
OVERACHIEVE WITH PLENTY OF SUNSHINE AND SUBSTANTIAL LOW LEVEL DRY
AIR. THIS SUPPORTS LEANING TOWARD THE HIGHER END OF GUIDANCE MAX
TEMPS /MID TO UPPER 60S SUNDAY AND AROUND 70 MONDAY/. THE DRY
AIRMASS AND WEAK SFC GRADIENT WILL SUPPORT OPTIMAL RADIATIONAL
COOLING POTENTIAL...SO MINS SUN NIGHT WILL CONTINUE TO BE QUITE COLD
FOR LATE MAY /UPPER 30S TO MID 40S/.
THE MID LEVEL RIDGE IS FORECAST TO BREAK DOWN EARLY NEXT WEAK AS
NUMEROUS SHORT WAVE IMPULSES ARE EJECTED OUT OF THE LONG WAVE TROUGH
OVER THE WRN US AND ACROSS THE CNTRL/NRN PLAINS. THE BULK OF THE 00Z
MODEL SUITE SUGGEST MCS DEVELOPMENT ACROSS THE UPPER MIDWEST OR WRN
GREAT LAKES MON AFTERNOON/NIGHT AS LOW LEVEL INFLOW STRENGTHENS. THE
POTENTIAL FOR REMNANT MCS ACTIVITY TO ADVANCE INTO SE MI REMAINS
HIGHLY UNCERTAIN AT THIS TIME. WHILE SEVERAL MODEL SOLUTIONS ARE
QUITE BULLISH WITH QPF OVER SE MI MON NIGHT AND TUES...THERE IS
LIKELY SOME SEMBLANCE OF CONVECTIVE FEEDBACK IN THE MODELS. THERE IS
ALSO CONCERN THAT THE MODELS HAVE A POOR HANDLING OF MCS
PROPAGATION...WHICH COULD LEAD TO REMNANT CONVECTION BEING MUCH
FARTHER SOUTH. THUS PLAN TO CARRY VERY LOW CHANCE POPS TUESDAY.
PERSISTENT LOW LEVEL S-SWLY FLOW SHOULD HOWEVER LIFT A WARMER AND
MORE HUMID AIRMASS INTO SRN LOWER MI BY MID WEEK...MARKED BY THE
PASSAGE OF A SFC WARM FRONT. THIS WILL JUSTIFY A CHANCE OF
SHOWERS/THUNDERSTORMS LATE TUES THROUGH WED.
THE ECMWF REMAINS STEADFAST IN DEVELOPING A MORE AMPLIFIED UPPER
TROUGH OVER THE WRN US BY MIDWEEK AS ENERGY EJECTS OUT OF THE GULF
OF ALASKA AND INTO THE WEST COAST. A SEASONALLY STRONG UPPER JET
WITHIN THE BASE OF THE DEEP GULF OF ALASKA UPPER LOW AND CURRENT
AMPLIFIED NATURE OF THE FLOW LENDS SUPPORT TO THE ECMWF. THIS
SOLUTION BUILDS THE SUBTROPICAL RIDGE FARTHER NORTH INTO THE ERN US
LATE IN THE WEEK AND SUGGESTS SE MI MAY BE CAPPED. EVEN THE LESS
AMPLIFIED GFS BUILDS MID LEVEL HEIGHTS SUBSTANTIALLY ACROSS SE MI.
THUS THE FORECAST FOR THE LATER HALF OF NEXT WEEK WILL HAVE VERY LOW
POPS WITH MAX TEMPS WELL INTO THE 80S.
MARINE...
A STABLE ANTICYCLONE WILL EXPAND ACROSS THE GREAT LAKES THROUGH THE
HOLIDAY WEEKEND. THIS WEATHER FEATURE WILL BE RESPONSIBLE FOR MORE
TYPICAL MARINE CONDITIONS FOR LATE MAY. WAVE HEIGHTS ARE ONLY
EXPECTED TO RANGE IN THE 1 TO 2 FOOT RANGE IN MANY AREAS THROUGHOUT
THE WEEKEND.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
SHORT TERM...CB
LONG TERM....SC
MARINE.......CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
603 PM CDT Sat May 25 2013
.SHORT TERM...(This Evening through Sunday)
Issued at 345 PM CDT SAT MAY 25 2013
Very few changes were needed to the forecast through tomorrow. Based
on latest high res models, radar, and satellite trends it appears,
other than a stray shower across the MO/IA border, the CWA should
remain dry this evening. Later tonight a small cluster of storms is
progged to work in from the west, but the latest HRRR depicts a
weaker system than what much of the NRN third of the CWA experienced
early this morning. At this time I have an overnight precip forecast
that favors the northern half of the CWA with higher chance pops
compared to lower chances to the south. As for tomorrow, more of
the same with lingering scattered morning showers and weak
thunderstorms with perhaps redevelopment in the afternoon.
Temperature wise the CWA will remain mild and rather muggy as
compared to the past several days under partly to mostly cloudy
skies.
.LONG TERM...(Sunday Night through Saturday)
Issued at 345 PM CDT SAT MAY 25 2013
The potential for wet weather looks to bracket either end of the
work week, though there will be plenty of dry days in between.
Shortwave ridge will be dominating the Central Plains as Memorial
Day dawns, with nocturnal thunderstorm activity likely lingering
through the morning hours. In general, operational and ensemble
models continue to advertise that this modest ridge will stay in
place across the Plains States through Tuesday, when the west CONUS
trough will finally begin to shift east. As the trough begins to
move into the Plains the storm track will shift farther north which
should give most locations in our forecast areas a break from the
rain chances. However, given the negative tilt to the trough as it
shifts into the Plains, and the general synoptic pattern, thoughts
are that storms will not only return tot he forecast, but severe
weather may plague the region by the end of the work week.
Currently, the best potential for storms looks to be Thursday night
and Friday night as the nocturnal jet cranks up ahead of the west
CONUS trough.
Otherwise, with the prevailing storm track, and by extension the
prevailing westerlies, remaining to the north of Kansas and Missouri
through the work week we expect temperatures to rise to a category
or two above normal through the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday Evening)
Issued at 603 PM CDT SAT MAY 25 2013
Convection has blossomed across western Kansas however models seem to
be evaporating this convection as it moves eastward tonight. With
temperature/dewpoint spreads of 15-20 degrees across the area, that
seems reasonable so have left TAFs dry overnight. It appears better chance for
convection may come tomorrow afternoon but no confidence in timing or
placement to include in the TAF at the moment. GFS MOS/LAMP as well
as NAM BUFR soundings are hinting at MVFR cigs tomorrow morning but
continue to think boundary layer is too moist so have held off on
inclusion in the TAF. Winds will be out of the south between 10-15kts
through tomorrow afternoon when they will become gusty around
20-25kts.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Pietrycha
LONG TERM...Cutter
AVIATION...73
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
347 PM CDT Sat May 25 2013
.SHORT TERM...(This Evening through Sunday)
Issued at 345 PM CDT SAT MAY 25 2013
Very few changes were needed to the forecast through tomorrow. Based
on latest high res models, radar, and satellite trends it appears,
other than a stray shower across the MO/IA border, the CWA should
remain dry this evening. Later tonight a small cluster of storms is
progged to work in from the west, but the latest HRRR depicts a
weaker system than what much of the NRN third of the CWA experienced
early this morning. At this time I have an overnight precip forecast
that favors the northern half of the CWA with higher chance pops
compared to lower chances to the south. As for tomorrow, more of
the same with lingering scattered morning showers and weak
thunderstorms with perhaps redevelopment in the afternoon.
Temperature wise the CWA will remain mild and rather muggy as
compared to the past several days under partly to mostly cloudy
skies.
.LONG TERM...(Sunday Night through Saturday)
Issued at 345 PM CDT SAT MAY 25 2013
The potential for wet weather looks to bracket either end of the
work week, though there will be plenty of dry days in between.
Shortwave ridge will be dominating the Central Plains as Memorial
Day dawns, with nocturnal thunderstorm activity likely lingering
through the morning hours. In general, operational and ensemble
models continue to advertise that this modest ridge will stay in
place across the Plains States through Tuesday, when the west CONUS
trough will finally begin to shift east. As the trough begins to
move into the Plains the storm track will shift farther north which
should give most locations in our forecast areas a break from the
rain chances. However, given the negative tilt to the trough as it
shifts into the Plains, and the general synoptic pattern, thoughts
are that storms will not only return tot he forecast, but severe
weather may plague the region by the end of the work week.
Currently, the best potential for storms looks to be Thursday night
and Friday night as the nocturnal jet cranks up ahead of the west
CONUS trough.
Otherwise, with the prevailing storm track, and by extension the
prevailing westerlies, remaining to the north of Kansas and Missouri
through the work week we expect temperatures to rise to a category
or two above normal through the week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1232 PM CDT SAT MAY 25 2013
For this afternoon, I am expecting VFR cigs and vis along with south
to southwest winds under 10 kts with brief gusts to 15 kts. Later
tonight the possibility exists for the development of scattered SHRA
and TSRA. Forecast confidence is low as to whether the three
terminals will see any of the activity. For that reason have placed
VCTS in the TAFS beginning late tonight. The scattered SHRA/TSRA are expected
to persist through the remainder of the TAF period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Pietrycha
LONG TERM...Cutter
AVIATION...Pietrycha
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
311 PM CDT SAT MAY 25 2013
.DISCUSSION...
ALTHOUGH TIMING OF HIGHEST CONCENTRATION OF ANY CONVECTION IS THE
MAIN CHALLENGE FOR ANY GIVEN PERIOD WELL INTO NEXT WEEK...PATTERN
LOOKS TO REMAIN ACTIVE WITH PRECIP CHANCES GOOD IF NOT LIKELY MOST
AREAS MOST EVENINGS/OVERNIGHT PDS.
AT 19Z SURFACE BOUNDARY EXTENDED FROM JUST N OF FNB TO JUST SW OF
OLU/BVN WITH RESIDUAL COOL OUTFLOW FROM MORNING CONVECTION
REINFORCING FRONT. CONVERGENCE NEAR BOUNDARY HAD INCREASED CU
FIELD WCNTRL ZONES AND LATEST RAP MESO ANALYSIS PLACED AXIS OF
2000-3000 J/KG ML CAPE ACROSS THAT AREA WITH LITTLE/NO CIN. SO
THERE REMAINS SOME POSSIBILITY OF CONVECTION DEVELOPING NEAR/N OF
THIS BOUNDARY EARLY THIS EVENING...ESPECIALLY AS ANY SUBSIDENCE
EFFECTS OF DEPARTING MCV FROM EARLIER CONVECTION GETS FARTHER
REMOVED. LATER THIS EVENING/OVERNIGHT HIGH PLAINS CONVECTION WILL
PROBABLY MAKE A RUN TOWARD/INTO FA...POSSIBLY CONSOLIDATING MORE
ACROSS NRN ZONES AIDED BY RR ENTRANCE REGION OF WEAK UPPER JET
SEGMENT. HOWEVER...CAN/T RULE OUT ACTIVITY FARTHER S AS WELL SINCE
BOUNDARY MAY NOT MOVE MUCH TONIGHT. LOW LEVEL JET DOES STRENGTHEN
SOME INTO FRONT OVERNIGHT...BUT STRONGEST/MORE CONVERGENT AREA NOT
NECESSARILY FOCUSED ACROSS THE FORECAST AREA...SO CONFIDENCE ON
WIDESPREAD HEAVY RAINFALL NOT VERY GOOD. THAT SAID...SMALL AREA OF
NRN IA ZONES DID PICK UP 1-2+ INCHES OF RAIN LAST NIGHT AND THAT
AREA APPEARS TO HAVE THE HIGHEST CHANCE OF SIGNIFICANT RAINS
TONIGHT AS MOISTURE REMAINS PLENTIFUL WITH PWATS AROUND 1.5
INCHES. THUS ISSUED A SMALL FLASH FLOOD WATCH NE OF OMAHA TO MATCH
UP WITH DMX WHERE HEAVIER RAIN WAS MORE WIDESPREAD.
DECREASED POPS DIURNALLY ON SUNDAY LIKE TODAY ALTHOUGH IT WAS
NOTED THAT FOR SEVERAL RUNS NOW NAM HAD DEVELOPED A SMALL MCS AND
DROPPED IT SE ACROSS FA DURING THE AFTERNOON. FORECAST WAS NOT
BASED ON THAT SCENARIO. ALSO MODELS HINTING AT MORE LOW LEVEL
MOISTURE WITH LOW CLOUDS POSSIBLY LINGERING INTO THE AFTERNOON.
THUS INCREASED SKY COVER. IF CLOUDS HOLD ALL DAY CONVECTIVE
DEVELOPMENT COULD BE ALTERED AS WELL AS HIGH TEMPERATURES.
OTHERWISE...LIKELY POPS MANY AREAS AGAIN WERE MENTIONED SUN NIGHT.
MONDAY POSSIBLY A VERY SIMILAR SCENARIO...ALTHOUGH FINER DETAILS
PROBABLY IMPACTED BY PREVIOUS PERIODS CONVECTION BOTH DAYS.
SOME INDICATION BY MODELS THAT A FRONT...POSSIBLY AIDED BY
OVERNIGHT CONVECTION...WILL PUSH S INTO NRN ZONES ON TUESDAY AS A
STRONGER WAVE EJECTS ACROSS CANADIAN PRAIRIE. COOLING AT H85
MINIMAL FOR THAT AREA...BUT NE WINDS AND POSSIBLE LOW CLOUDS
COULD KEEP MAX TEMPS COOLER AND THIS COULD NEED ATTENTION IN LATER
FORECASTS. OTHERWISE...THIS BOUNDARY AND UPPER TROUGH BEGINNING TO
APPROACH AREA WILL KEEP AREA ACTIVE TUESDAY/TUE NGT. WEDNESDAY
COULD POSSIBLY BE MORE OF A LULL WITH WARMER TEMPERATURES BEFORE
STRONGER ENERGY PUNCHES ACROSS CNTRL PLAINS WED NGT/THURSDAY
INCREASING COVERAGE/CHCS AGAIN. ALTHOUGH SEVERE POTENTIAL WILL
EXIST INTO TUESDAY...THIS STRONGER TROUGH COULD BRING A HEIGHTENED
RISK OF SVR WEATHER TO AREA LATE NEXT WEEK.
CHERMOK
&&
.AVIATION...
18Z TAFS FOR KOMA...KLNK AND KOFK.
A WARM FRONT SLOWLY LIFTING OVER THE CNTRL PLAINS WILL BE THE
FOCUS FOR TSRA ACTIVITY OVER ERN NEB LATER TONIGHT. LLVL MOISTURE
WILL CONTINUE STREAMING NWD INTO THE REGION THROUGH THIS EVENING.
THIS ALONG WITH A STRENGTHENING LLVL JET...TSRA ACTIVITY SHOULD
INCREASE SOMEWHAT IN AREAL COVERAGE...MAINLY OVER NERN NEB. DUE
TO SOME UNCERTAINTY THOUGH HOW FAST THE SFC BNDRY WILL
LIFT...HAVE DECIDED TO JUST COVER ALL SITES WITH PROB30 GROUPS
BTWN 26/03Z- 12Z. MEANWHILE...WITH PERSISTENT MOISTURE ADVECTION
EXPECTED...CONDITIONS SHOULD BEGIN DETERIORATING FROM VFR TO IFR
BY OR SHORTLY AFT 26/06Z. GOOD INDICATION FROM MODEL GUIDANCE THAT
MVFR CONDITIONS THEN WILL PREVAIL THE REST OF THE FCST PD.
DEE
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...FLASH FLOOD WATCH FROM MIDNIGHT CDT TONIGHT THROUGH SUNDAY
MORNING FOR IAZ043-055-056.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1245 PM CDT SAT MAY 25 2013
.UPDATE...
ISSUED AT 1131 AM CDT SAT MAY 25 2013
THIS WILL SERVE AS THE NOON ESTF UPDATE.
TEMPS OVER OUR KS COUNTIES ARE RAPIDLY APPROACHING 80F. SO HIGH
TEMPS HAVE BEEN RAISED ALL AREAS FOR THIS AFTN.
THE FLOOD WARNING FOR SHERMAN/HOWARD COUNTIES WAS ALLOWED TO
EXPIRE AT 1030AM. CALLS TO REGIONAL DISPATCH INDICATE WATERS WERE
RECEDING. HOWEVER...COORDINATED WITH THE RFC AND WE WILL BE
CLOSELY MONITORING AREA RIVERS PARTICULARLY N OF I-80 AFTER THE
VERY HVY RAINS LAST NGT. HIGHEST TOTAL SO FAR IS 4.28" 2 W OF LOUP
CITY.
THANK YOU VERY MUCH TO ALL COOP/SPOTTER/NE-RAIN/COCORAHS OBSERVERS.
THE BOUNDARY LEFT BY LAST NGT`S MCS WILL PLAY AN IMPORTANT ROLE IN
TSTM DEVELOPMENT THIS AFTN-EVE. MEAN S LOW-LVL FLOW WILL BE
MAINTAINED JUST E OF THE LEE TROF WHICH WILL RESULT IN CONVERGENCE
AND ASCENT ALONG THIS BOUNDARY. WE/VE NOTED A PLUME OF VERY WARM
MID-LVL TEMPS ON THE DDC SOUNDING WHICH WILL ADVECT OVER THE FCST
AREA TODAY. THIS WILL DELAY TSTM DEVELOP UNTIL LATE...AND COULD
KEEP IT FROM OCCURRING AT ALL S OF THE BOUNDARY.
RADAR AND VIS SATELLITE SHOWS AN MCV JUST SW OF THE FCST AREA NEAR
HYS. THIS WILL BE A WILDCARD AS IT COULD TRIGGER TSTMS IN THE WARM
SECTOR...BUT DOES IT OCCUR DURING THE DAYLGT HRS? IT/S HEADING NE
AND WILL MOVE ACROSS OUR SE COUNTIES. IF IT HOLDS OFF UNTIL TNGT
THEN IT COULD BE E OF THE FCST AREA.
WITH VERY LITTLE CLOUD COVER N OF THE BOUNDARY...DIABATIC HEATING
WILL DESTABILIZE THE ATMS. TEMPS IN THE 80S...DWPTS IN THE 60S AND
MID-LVL LAPSE RATES OF 8 DEG C/KM WILL RESULT IN MLCAPE OF
2000-3000 J/KG. MID-LVL SHEAR WILL BE AROUND 30 KTS...SUPPORTIVE
OF SUPERCELLS DUE TO BACKED LOW-LVL SE WINDS.
0-1 KM EHI WILL BE IN EXCESS OF 1 WHERE WINDS ARE BACKED. THIS
COMBINED WITH LOWEST LCL HGTS SUGGESTS TORNADO POTENTIAL WILL BE
ALONG AND N OF A LINE FROM LXN-HJH.
SATELLITE-DERIVED PW SHOWS A PLUME OF SUBTROPICAL MSTR EXTENDING N
FROM THE CARIBBEAN INTO THE CNTRL PLAINS. LBF/OAX/TOP 12Z SOUNDINGS
ARE ALL 150-170% OF NORMAL. ANY CLUSTERING OF TSTMS WILL THREATEN
FLASH FLOODING...ESPECIALLY HERE HVY RAIN OCCURRED LAST NGT.
ORDINARY STORM MVMT WILL BE 05025 KTS. SUPERCELL MVMT: E 10-15 KTS
WHICH COULD ALSO BE TROUBLE FOR EXCESSIVE RAINFALL.
HWO AND EHWO HAVE BEEN UPDATED WITH OUR LATEST THINKING.
UPDATE ISSUED AT 920 AM CDT SAT MAY 25 2013
MCS HAS BASICALLY EXITED. RADAR IS SHOWING SOME SHWRS STILL
PERCOLATING FROM HLC-PHG AND DRIFTING NE TOWARD THE STATE LINE.
THESE SHWRS /WITH AN OCCASIONAL RUMBLE OF THUNDER/ WERE DEVELOPING
AS THE REMAINS OF THE LLJ ARE STILL LARGELY PERPENDICULAR TO THE
CONVECTIVELY-REINFORCED WARM FRONT THAT EXTENDS W-E ACROSS NRN KS.
EXPECT THESE SHWRS TO EVENTUALLY END. SO SHORT-TERM ADJUSTMENTS
THRU NOON HAVE ADJUSTED POPS AND SKYCOVER ACCORDINGLY.
12Z LBF/OAX/TOP SOUNDINGS SUPPORT HIGH TEMPS IN THE LOW-MID 80S E
OF HWY 281 AND MID-UPR 80S TO THE W.
WE WILL CONT TO EVALUATE TSTM AND SVR WX POTENTIAL FOR THIS AFTN-
EVE. CERTAINLY THE BOUNDARY LAID DOWN FROM THIS MCS WILL BE
WATCHED CLOSELY.
PLEASE FOLLOW OUR LSR/RTP/LCO PRODUCTS FOR THE IMPRESSIVE RAINFALL
TOTALS OVERNGT. MANY REPORTS OF 2-3" IN A SWATH FROM SHERMAN-HALL-
HAMILTON-CLAY-THAYER COUNTIES. THIS MAY SET THE STAGE FOR SOME
FLOODING WITH MULTIPLE THREATS OF TSTMS THE NEXT SVRL DAYS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM CDT SAT MAY 25 2013
FOCUS REMAINS ON TSTM POTENTIAL.
TSTMS CONTINUE EARLY THIS MORNING WITH MCS ROLLING EAST ACROSS
CENTRAL/EASTERN NEBRASKA. MAIN IMPACT CURRENTLY FM CONVECTION IS HEAVY
RAINFALL...WITH MANY LOCATIONS NORTH OF INTERSTATE 80 PICKING UP
AT LEAST AN INCH OF RAIN. WE HAVE HAD ONE REPORT OF 3.13 INCHES SO
FAR AT LOUP CITY WITH RAIN STILL FALLING.
THIS INITIAL ROUND OF CONVECTION WILL CONTINUE TO MOVE EAST/END THIS
MORNING THEN ATTENTION TURNS TO ADDITIONAL CHANCES FOR CONVECTION
THIS AFTN. SFC BOUNDARY HAS SETTLED NEAR THE NEB/KS STATELINE AND
FRONT IS PROGGED TO LIFT NORTHWARD THIS AFTN INTO SC NEB...WITH SFC
LOW ORIENTED IN EASTERN COLORADO AND DRY LINE ALONG THE HIGH PLAINS
REGION. FRONTAL BOUNDARY AND ANY RESIDUAL OUTFLOW BOUNDARIES WILL BE
FOCUS FOR CONVECTION AGAIN THIS AFTN/EVE AND BOUNDARY PLACEMENT
WILL NEED TO BE MONITORED CLOSELY. CAP LOOKS TO HOLD INITIALLY
HOWEVER MODELS ARE INDICATING DEVELOPMENT ALONG THE DRY LINE AND
ALONG/NORTH OF WARM FRONTAL BOUNDARY...AND HAVE FOLLOWED CLOSER TO
RAP MODEL FOR POTENTIAL DEVELOPMENT THIS AFTN. STORMS FOR
TODAY/TONIGHT HAVE THE POTENTIAL TO BE MORE VOLATILE WITH SEVERE
PARAMETERS INDICATING POTENTIAL FOR SUPERCELLS. INSTABILITY IS
PROGGED AROUND 4000 J/KG WITH SHEAR OF 40KTS OR SO AND STORMS WILL
BE CAPABLE OF PRODUCING VERY LARGE HAIL...DAMAGING WINDS AND EVEN
TORNADOES IN VCNTY OF BOUNDARIES. HEAVY RAINFALL/FLOODING ALSO
REMAINS A CONCERN DUE TO THE HEAVY OVERNIGHT/EARLY THIS MORNING
AND PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH TO INCH
AND A HALF AND ARE A 100 TO 150 PERCENT OF NORMAL. ALL OF THIS
BEING SAID...MODELS ARE NOT CONSISTENT IN FRONTAL POSITION WHICH
IS KEY TO DEVELOPMENT THIS AFTN. AGAIN FEEL RAP AND LATEST SREF
RUN HAS A BETTER HANDLE ON THE FARTHER SOUTH WARM FRONTAL POSITION
ACROSS OUR AREA TODAY...AND WILL NEED TO MONITOR CLOSELY.
OTHERWISE...LOOK FOR SOME WARMER TEMPS THIS AFTN AND STEADY/GUSTY
WINDS WITH THE HIGHEST WIND SPEEDS EXPECTED ACROSS NC KANSAS/SOUTH
OF WARM FRONT...WHERE WINDY CONDITIONS ARE POSSIBLE WITH GUSTS OF
30+ MPH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 423 AM CDT SAT MAY 25 2013
SUNDAY THROUGH FRIDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS MOST EVERY DAY AND TEMPERATURES THROUGH
THE PERIOD.
A VERY ACTIVE WEATHER PATTERN WILL AFFECT THE FORECAST AREA THROUGH
THE PERIOD. AN UPPER LEVEL LOW DEVELOPS IN THE WESTERN CONUS AND
GRADUALLY MOVES THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS BY FRIDAY. THIS UPPER LOW WILL SEND WAVES INTO THE FORECAST
AREA THROUGH THE PERIOD. THE MODELS ARE SIMILAR IN THE MAIN
FEATURES...BUT THE ECMWF HAS A LITTLE STRONGER AMPLITUDE MID WEEK.
EACH OF THE WAVES WILL HAVE A CHANCE FOR SOME THUNDERSTORMS WHEN
THEY MOVE THROUGH. IT CERTAINLY WILL NOT BE A RAIN OUT...IT WILL NOT
RAIN ALL OF THE TIME...BUT THERE WILL BE CHANCES FOR SOME SHOWERS
AND THUNDERSTORMS AT VARIOUS TIMES DURING THE PERIOD.
THE BEST CHANCES FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND
SUNDAY NIGHT...DURING WHICH TIME THE CAPE APPROACHES 5000 J/KG.
ANOTHER GOOD CHANCE WILL BE MONDAY AFTERNOON AND MONDAY NIGHT WITH
CAPES OVER 5000 J/KG AGAIN. BEYOND MONDAY THE MODELS HAVE A FEW
TIMING DIFFERENCES WITH THE UPPER LEVEL WAVES THAT MOVE THROUGH THE
AREA AND THEREFORE TIMING THUNDERSTORMS IS MORE OF A CHALLENGE.
TEMPERATURES WILL BE THE WARMEST SUNDAY THROUGH TUESDAY THEN SLOWLY
COOL OFF TOWARD THE END OF THE WEEK. TEMPERATURES SHOULD STILL
REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1244 PM CDT SAT MAY 25 2013
UNCERTAINTY IS ABOVE AVERAGE DUE TO TSTM POTENTIAL.
THIS AFTN: VFR WITH A SLGT CHC OF AN IFR TSTM AFTER 21Z. SSE WINDS
WILL GUST TO AROUND 22 KTS.
TNGT: VFR MUCH OF THE NGT BUT THERE IS A SLGT CHC OF A TSTM. JUST
CANNOT PINPOINT IT ATTM. GUSTINESS OF SSE WINDS WILL DIMINISH
AROUND SUNSET...BUT THERE COULD BE SOME OCCASIONAL GUSTS TO NEAR
20 KTS.
SUN THRU 18Z: VFR. SSE WINDS GUST UP TO 25 KTS.
CIG CONFIDENCE: MEDIUM
VSBY CONFIDENCE: MEDIUM
WIND CONFIDENCE: HIGH EXCEPT NEAR TSTMS
WX CONFIDENCE: LOW DUE TO TSTM POTENTIAL
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...JCB
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION...CORRECTED
NWS HASTINGS NE
1138 AM CDT SAT MAY 25 2013
.UPDATE...
ISSUED AT 1131 AM CDT SAT MAY 25 2013
THIS WILL SERVE AS THE NOON ESTF UPDATE.
TEMPS OVER OUR KS COUNTIES ARE RAPIDLY APPROACHING 80F. SO HIGH
TEMPS HAVE BEEN RAISED ALL AREAS FOR THIS AFTN.
THE FLOOD WARNING FOR SHERMAN/HOWARD COUNTIES WAS ALLOWED TO
EXPIRE AT 1030AM. CALLS TO REGIONAL DISPATCH INDICATE WATERS WERE
RECEDING. HOWEVER...COORDINATED WITH THE RFC AND WE WILL BE
CLOSELY MONITORING AREA RIVERS PARTICULARLY N OF I-80 AFTER THE
VERY HVY RAINS LAST NGT. HIGHEST TOTAL SO FAR IS 4.28" 2 W OF LOUP
CITY.
THANK YOU VERY MUCH TO ALL COOP/SPOTTER/NE-RAIN/COCORAHS OBSERVERS.
THE BOUNDARY LEFT BY LAST NGT`S MCS WILL PLAY AN IMPORTANT ROLE IN
TSTM DEVELOPMENT THIS AFTN-EVE. MEAN S LOW-LVL FLOW WILL BE
MAINTAINED JUST E OF THE LEE TROF WHICH WILL RESULT IN CONVERGENCE
AND ASCENT ALONG THIS BOUNDARY. WE/VE NOTED A PLUME OF VERY WARM
MID-LVL TEMPS ON THE DDC SOUNDING WHICH WILL ADVECT OVER THE FCST
AREA TODAY. THIS WILL DELAY TSTM DEVELOP UNTIL LATE...AND COULD
KEEP IT FROM OCCURRING AT ALL S OF THE BOUNDARY.
RADAR AND VIS SATELLITE SHOWS AN MCV JUST SW OF THE FCST AREA NEAR
HYS. THIS WILL BE A WILDCARD AS IT COULD TRIGGER TSTMS IN THE WARM
SECTOR...BUT DOES IT OCCUR DURING THE DAYLGT HRS? IT/S HEADING NE
AND WILL MOVE ACROSS OUR SE COUNTIES. IF IT HOLDS OFF UNTIL TNGT
THEN IT COULD BE E OF THE FCST AREA.
WITH VERY LITTLE CLOUD COVER N OF THE BOUNDARY...DIABATIC HEATING
WILL DESTABILIZE THE ATMS. TEMPS IN THE 80S...DWPTS IN THE 60S AND
MID-LVL LAPSE RATES OF 8 DEG C/KM WILL RESULT IN MLCAPE OF
2000-3000 J/KG. MID-LVL SHEAR WILL BE AROUND 30 KTS...SUPPORTIVE
OF SUPERCELLS DUE TO BACKED LOW-LVL SE WINDS.
0-1 KM EHI WILL BE IN EXCESS OF 1 WHERE WINDS ARE BACKED. THIS
COMBINED WITH LOWEST LCL HGTS SUGGESTS TORNADO POTENTIAL WILL BE
ALONG AND N OF A LINE FROM LXN-HJH.
SATELLITE-DERIVED PW SHOWS A PLUME OF SUBTROPICAL MSTR EXTENDING N
FROM THE CARIBBEAN INTO THE CNTRL PLAINS. LBF/OAX/TOP 12Z SOUNDINGS
ARE ALL 150-170% OF NORMAL. ANY CLUSTERING OF TSTMS WILL THREATEN
FLASH FLOODING...ESPECIALLY HERE HVY RAIN OCCURRED LAST NGT.
ORDINARY STORM MVMT WILL BE 05025 KTS. SUPERCELL MVMT: E 10-15 KTS
WHICH COULD ALSO BE TROUBLE FOR EXCESSIVE RAINFALL.
HWO AND EHWO HAVE BEEN UPDATED WITH OUR LATEST THINKING.
UPDATE ISSUED AT 920 AM CDT SAT MAY 25 2013
MCS HAS BASICALLY EXITED. RADAR IS SHOWING SOME SHWRS STILL
PERCOLATING FROM HLC-PHG AND DRIFTING NE TOWARD THE STATE LINE.
THESE SHWRS /WITH AN OCCASIONAL RUMBLE OF THUNDER/ WERE DEVELOPING
AS THE REMAINS OF THE LLJ ARE STILL LARGELY PERPENDICULAR TO THE
CONVECTIVELY-REINFORCED WARM FRONT THAT EXTENDS W-E ACROSS NRN KS.
EXPECT THESE SHWRS TO EVENTUALLY END. SO SHORT-TERM ADJUSTMENTS
THRU NOON HAVE ADJUSTED POPS AND SKYCOVER ACCORDINGLY.
12Z LBF/OAX/TOP SOUNDINGS SUPPORT HIGH TEMPS IN THE LOW-MID 80S E
OF HWY 281 AND MID-UPR 80S TO THE W.
WE WILL CONT TO EVALUATE TSTM AND SVR WX POTENTIAL FOR THIS AFTN-
EVE. CERTAINLY THE BOUNDARY LAID DOWN FROM THIS MCS WILL BE
WATCHED CLOSELY.
PLEASE FOLLOW OUR LSR/RTP/LCO PRODUCTS FOR THE IMPRESSIVE RAINFALL
TOTALS OVERNGT. MANY REPORTS OF 2-3" IN A SWATH FROM SHERMAN-HALL-
HAMILTON-CLAY-THAYER COUNTIES. THIS MAY SET THE STAGE FOR SOME
FLOODING WITH MULTIPLE THREATS OF TSTMS THE NEXT SVRL DAYS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM CDT SAT MAY 25 2013
FOCUS REMAINS ON TSTM POTENTIAL.
TSTMS CONTINUE EARLY THIS MORNING WITH MCS ROLLING EAST ACROSS
CENTRAL/EASTERN NEBRASKA. MAIN IMPACT CURRENTLY FM CONVECTION IS HEAVY
RAINFALL...WITH MANY LOCATIONS NORTH OF INTERSTATE 80 PICKING UP
AT LEAST AN INCH OF RAIN. WE HAVE HAD ONE REPORT OF 3.13 INCHES SO
FAR AT LOUP CITY WITH RAIN STILL FALLING.
THIS INITIAL ROUND OF CONVECTION WILL CONTINUE TO MOVE EAST/END THIS
MORNING THEN ATTENTION TURNS TO ADDITIONAL CHANCES FOR CONVECTION
THIS AFTN. SFC BOUNDARY HAS SETTLED NEAR THE NEB/KS STATELINE AND
FRONT IS PROGGED TO LIFT NORTHWARD THIS AFTN INTO SC NEB...WITH SFC
LOW ORIENTED IN EASTERN COLORADO AND DRY LINE ALONG THE HIGH PLAINS
REGION. FRONTAL BOUNDARY AND ANY RESIDUAL OUTFLOW BOUNDARIES WILL BE
FOCUS FOR CONVECTION AGAIN THIS AFTN/EVE AND BOUNDARY PLACEMENT
WILL NEED TO BE MONITORED CLOSELY. CAP LOOKS TO HOLD INITIALLY
HOWEVER MODELS ARE INDICATING DEVELOPMENT ALONG THE DRY LINE AND
ALONG/NORTH OF WARM FRONTAL BOUNDARY...AND HAVE FOLLOWED CLOSER TO
RAP MODEL FOR POTENTIAL DEVELOPMENT THIS AFTN. STORMS FOR
TODAY/TONIGHT HAVE THE POTENTIAL TO BE MORE VOLATILE WITH SEVERE
PARAMETERS INDICATING POTENTIAL FOR SUPERCELLS. INSTABILITY IS
PROGGED AROUND 4000 J/KG WITH SHEAR OF 40KTS OR SO AND STORMS WILL
BE CAPABLE OF PRODUCING VERY LARGE HAIL...DAMAGING WINDS AND EVEN
TORNADOES IN VCNTY OF BOUNDARIES. HEAVY RAINFALL/FLOODING ALSO
REMAINS A CONCERN DUE TO THE HEAVY OVERNIGHT/EARLY THIS MORNING
AND PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH TO INCH
AND A HALF AND ARE A 100 TO 150 PERCENT OF NORMAL. ALL OF THIS
BEING SAID...MODELS ARE NOT CONSISTENT IN FRONTAL POSITION WHICH
IS KEY TO DEVELOPMENT THIS AFTN. AGAIN FEEL RAP AND LATEST SREF
RUN HAS A BETTER HANDLE ON THE FARTHER SOUTH WARM FRONTAL POSITION
ACROSS OUR AREA TODAY...AND WILL NEED TO MONITOR CLOSELY.
OTHERWISE...LOOK FOR SOME WARMER TEMPS THIS AFTN AND STEADY/GUSTY
WINDS WITH THE HIGHEST WIND SPEEDS EXPECTED ACROSS NC KANSAS/SOUTH
OF WARM FRONT...WHERE WINDY CONDITIONS ARE POSSIBLE WITH GUSTS OF
30+ MPH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 423 AM CDT SAT MAY 25 2013
SUNDAY THROUGH FRIDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS MOST EVERY DAY AND TEMPERATURES THROUGH
THE PERIOD.
A VERY ACTIVE WEATHER PATTERN WILL AFFECT THE FORECAST AREA THROUGH
THE PERIOD. AN UPPER LEVEL LOW DEVELOPS IN THE WESTERN CONUS AND
GRADUALLY MOVES THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS BY FRIDAY. THIS UPPER LOW WILL SEND WAVES INTO THE FORECAST
AREA THROUGH THE PERIOD. THE MODELS ARE SIMILAR IN THE MAIN
FEATURES...BUT THE ECMWF HAS A LITTLE STRONGER AMPLITUDE MID WEEK.
EACH OF THE WAVES WILL HAVE A CHANCE FOR SOME THUNDERSTORMS WHEN
THEY MOVE THROUGH. IT CERTAINLY WILL NOT BE A RAIN OUT...IT WILL NOT
RAIN ALL OF THE TIME...BUT THERE WILL BE CHANCES FOR SOME SHOWERS
AND THUNDERSTORMS AT VARIOUS TIMES DURING THE PERIOD.
THE BEST CHANCES FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND
SUNDAY NIGHT...DURING WHICH TIME THE CAPE APPROACHES 5000 J/KG.
ANOTHER GOOD CHANCE WILL BE MONDAY AFTERNOON AND MONDAY NIGHT WITH
CAPES OVER 5000 J/KG AGAIN. BEYOND MONDAY THE MODELS HAVE A FEW
TIMING DIFFERENCES WITH THE UPPER LEVEL WAVES THAT MOVE THROUGH THE
AREA AND THEREFORE TIMING THUNDERSTORMS IS MORE OF A CHALLENGE.
TEMPERATURES WILL BE THE WARMEST SUNDAY THROUGH TUESDAY THEN SLOWLY
COOL OFF TOWARD THE END OF THE WEEK. TEMPERATURES SHOULD STILL
REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 540 AM CDT SAT MAY 25 2013
TSTMS CONTINUE IN THE VICINITY OF KGRI EARLY THIS MORNING. THIS
INITIAL ROUND OF CONVECTION WILL END THIS MORNING WITH
REDEVELOPMENT OF STORMS FORECAST THIS AFTN AND EVENING. LOOK FOR
VARIABLE WINDS TO TRANSITIION SOUTHERLY TODAY...BUT WILL BE
VARIABLE/GUSTY IN VCNTY OF STORMS. CIGS/VSBYS WILL MAINLY BE VFR BUT
WILL DROP TO MVFR AND POTENTIALLY NEAR IFR DURING TSTM ACTIVITY.
SEVERE STORMS ARE POSSIBLE LATER TODAY/TONIGHT WITH LARGE
HAIL/DAMAGING WINDS/HEAVY RAINFALL THE MAIN HAZARDS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...JCB
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1132 AM CDT SAT MAY 25 2013
.UPDATE...
ISSUED AT 1131 AM CDT SAT MAY 25 2013
THIS WILL SERVE AS THE NOON ESTF UPDATE.
TEMPS OVER OUR KS COUNTIES ARE RAPIDLY APPROACHING 80F. SO HIGH
TEMPS HAVE BEEN RAISED ALL AREAS FOR THIS AFTN.
THE FLOOD WARNING FOR SHERMAN/HOWARD COUNTIES WAS ALLOWED TO
EXPIRE AT 1030AM. CALLS TO REGIONAL DISPATCH INDICATE WATERS WERE
RECEDING. HOWEVER...COORDINATED WITH THE RFC AND WE WILL BE
CLOSELY MONITORING AREA RIVERS PARTICULARLY N OF I-80 AFTER THE
VERY HVY RAINS LAST NGT. HIGHEST TOTAL SO FAR IS 4.28" 2 W OF LOUP
CITY.
THANK YOU VERY MUCH TO ALL COOP/SPOTTER/NE-RAIN/COCORAHS OBSERVERS.
WE BOUNDARY LEFT BY LAST NGT`S MCS WILL PLAY AN IMPORTANT ROLE IN
TSTM DEVELOPMENT THIS AFTN-EVE. MEAN S LOW-LVL FLOW WILL BE
MAINTAINED JUST E OF THE LEE TROF WHICH WILL RESULT IN CONVERGENCE
AND ASCENT ALONG THIS BOUNDARY. WE/VE NOTED A PLUME OF VERY WARM
MID-LVL TEMPS ON THE DDC SOUNDING WHICH WILL ADVECT OVER THE FCST
AREA TODAY. THIS WILL DELAY TSTM DEVELOP UNTIL LATE...AND COULD
KEEP IT FROM OCCURRING AT ALL S OF THE BOUNDARY.
RADAR AND VIS SATELLITE SHOWS AN MCV JUST SW OF THE FCST AREA NEAR
HYS. THIS WILL BE A WILDCARD AS IT COULD TRIGGER TSTMS IN THE WARM
SECTOR...BUT DOES IT OCCUR DURING THE DAYLGT HRS? IT/S HEADING NE
AND WILL MOVE ACROSS OUR SE COUNTIES. IF IT HOLDS OFF UNTIL TNGT
THEN IT COULD BE E OF THE FCST AREA.
WITH VERY LITTLE CLOUD COVER N OF THE BOUNDARY...DIABATIC HEATING
WILL DESTABILIZE THE ATMS. TEMPS IN THE 80S...DWPTS IN THE 60S AND
MID-LVL LAPSE RATES OF 8 DEG C/KM WILL RESULT IN MLCAPE OF
2000-3000 J/KG. MID-LVL SHEAR WILL BE AROUND 30 KTS...SUPPORTIVE
OF SUPERCELLS DUE TO BACKED LOW-LVL SE WINDS.
0-1 KM EHI WILL BE IN EXCESS OF 1 WHERE WINDS ARE BACKED. THIS
COMBINED WITH LOWEST LCL HGTS SUGGESTS TORNADO POTENTIAL WILL BE
ALONG AND N OF A LINE FROM LXN-HJH.
SATELLITE-DERIVED PW SHOWS A PLUME OF SUBTROPICAL MSTR EXTENDING N
FROM THE CARIBBEAN INTO THE CNTRL PLAINS. LBF/OAX/TOP 12Z SOUNDINGS
ARE ALL 150-170% OF NORMAL. ANY CLUSTERING OF TSTMS WILL THREATEN
FLASH FLOODING...ESPECIALLY HERE HVY RAIN OCCURRED LAST NGT.
ORDINARY STORM MVMT WILL BE 05025 KTS. SUPERCELL MVMT: E 10-15 KTS
WHICH COULD ALSO BE TROUBLE FOR EXCESSIVE RAINFALL.
HWO AND EHWO HAVE BEEN UPDATED WITH OUR LATEST THINKING.
UPDATE ISSUED AT 920 AM CDT SAT MAY 25 2013
MCS HAS BASICALLY EXITED. RADAR IS SHOWING SOME SHWRS STILL
PERCOLATING FROM HLC-PHG AND DRIFTING NE TOWARD THE STATE LINE.
THESE SHWRS /WITH AN OCCASIONAL RUMBLE OF THUNDER/ WERE DEVELOPING
AS THE REMAINS OF THE LLJ ARE STILL LARGELY PERPENDICULAR TO THE
CONVECTIVELY-REINFORCED WARM FRONT THAT EXTENDS W-E ACROSS NRN KS.
EXPECT THESE SHWRS TO EVENTUALLY END. SO SHORT-TERM ADJUSTMENTS
THRU NOON HAVE ADJUSTED POPS AND SKYCOVER ACCORDINGLY.
12Z LBF/OAX/TOP SOUNDINGS SUPPORT HIGH TEMPS IN THE LOW-MID 80S E
OF HWY 281 AND MID-UPR 80S TO THE W.
WE WILL CONT TO EVALUATE TSTM AND SVR WX POTENTIAL FOR THIS AFTN-
EVE. CERTAINLY THE BOUNDARY LAID DOWN FROM THIS MCS WILL BE
WATCHED CLOSELY.
PLEASE FOLLOW OUR LSR/RTP/LCO PRODUCTS FOR THE IMPRESSIVE RAINFALL
TOTALS OVERNGT. MANY REPORTS OF 2-3" IN A SWATH FROM SHERMAN-HALL-
HAMILTON-CLAY-THAYER COUNTIES. THIS MAY SET THE STAGE FOR SOME
FLOODING WITH MULTIPLE THREATS OF TSTMS THE NEXT SVRL DAYS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM CDT SAT MAY 25 2013
FOCUS REMAINS ON TSTM POTENTIAL.
TSTMS CONTINUE EARLY THIS MORNING WITH MCS ROLLING EAST ACROSS
CENTRAL/EASTERN NEBRASKA. MAIN IMPACT CURRENTLY FM CONVECTION IS HEAVY
RAINFALL...WITH MANY LOCATIONS NORTH OF INTERSTATE 80 PICKING UP
AT LEAST AN INCH OF RAIN. WE HAVE HAD ONE REPORT OF 3.13 INCHES SO
FAR AT LOUP CITY WITH RAIN STILL FALLING.
THIS INITIAL ROUND OF CONVECTION WILL CONTINUE TO MOVE EAST/END THIS
MORNING THEN ATTENTION TURNS TO ADDITIONAL CHANCES FOR CONVECTION
THIS AFTN. SFC BOUNDARY HAS SETTLED NEAR THE NEB/KS STATELINE AND
FRONT IS PROGGED TO LIFT NORTHWARD THIS AFTN INTO SC NEB...WITH SFC
LOW ORIENTED IN EASTERN COLORADO AND DRY LINE ALONG THE HIGH PLAINS
REGION. FRONTAL BOUNDARY AND ANY RESIDUAL OUTFLOW BOUNDARIES WILL BE
FOCUS FOR CONVECTION AGAIN THIS AFTN/EVE AND BOUNDARY PLACEMENT
WILL NEED TO BE MONITORED CLOSELY. CAP LOOKS TO HOLD INITIALLY
HOWEVER MODELS ARE INDICATING DEVELOPMENT ALONG THE DRY LINE AND
ALONG/NORTH OF WARM FRONTAL BOUNDARY...AND HAVE FOLLOWED CLOSER TO
RAP MODEL FOR POTENTIAL DEVELOPMENT THIS AFTN. STORMS FOR
TODAY/TONIGHT HAVE THE POTENTIAL TO BE MORE VOLATILE WITH SEVERE
PARAMETERS INDICATING POTENTIAL FOR SUPERCELLS. INSTABILITY IS
PROGGED AROUND 4000 J/KG WITH SHEAR OF 40KTS OR SO AND STORMS WILL
BE CAPABLE OF PRODUCING VERY LARGE HAIL...DAMAGING WINDS AND EVEN
TORNADOES IN VCNTY OF BOUNDARIES. HEAVY RAINFALL/FLOODING ALSO
REMAINS A CONCERN DUE TO THE HEAVY OVERNIGHT/EARLY THIS MORNING
AND PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH TO INCH
AND A HALF AND ARE A 100 TO 150 PERCENT OF NORMAL. ALL OF THIS
BEING SAID...MODELS ARE NOT CONSISTENT IN FRONTAL POSITION WHICH
IS KEY TO DEVELOPMENT THIS AFTN. AGAIN FEEL RAP AND LATEST SREF
RUN HAS A BETTER HANDLE ON THE FARTHER SOUTH WARM FRONTAL POSITION
ACROSS OUR AREA TODAY...AND WILL NEED TO MONITOR CLOSELY.
OTHERWISE...LOOK FOR SOME WARMER TEMPS THIS AFTN AND STEADY/GUSTY
WINDS WITH THE HIGHEST WIND SPEEDS EXPECTED ACROSS NC KANSAS/SOUTH
OF WARM FRONT...WHERE WINDY CONDITIONS ARE POSSIBLE WITH GUSTS OF
30+ MPH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 423 AM CDT SAT MAY 25 2013
SUNDAY THROUGH FRIDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS MOST EVERY DAY AND TEMPERATURES THROUGH
THE PERIOD.
A VERY ACTIVE WEATHER PATTERN WILL AFFECT THE FORECAST AREA THROUGH
THE PERIOD. AN UPPER LEVEL LOW DEVELOPS IN THE WESTERN CONUS AND
GRADUALLY MOVES THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS BY FRIDAY. THIS UPPER LOW WILL SEND WAVES INTO THE FORECAST
AREA THROUGH THE PERIOD. THE MODELS ARE SIMILAR IN THE MAIN
FEATURES...BUT THE ECMWF HAS A LITTLE STRONGER AMPLITUDE MID WEEK.
EACH OF THE WAVES WILL HAVE A CHANCE FOR SOME THUNDERSTORMS WHEN
THEY MOVE THROUGH. IT CERTAINLY WILL NOT BE A RAIN OUT...IT WILL NOT
RAIN ALL OF THE TIME...BUT THERE WILL BE CHANCES FOR SOME SHOWERS
AND THUNDERSTORMS AT VARIOUS TIMES DURING THE PERIOD.
THE BEST CHANCES FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND
SUNDAY NIGHT...DURING WHICH TIME THE CAPE APPROACHES 5000 J/KG.
ANOTHER GOOD CHANCE WILL BE MONDAY AFTERNOON AND MONDAY NIGHT WITH
CAPES OVER 5000 J/KG AGAIN. BEYOND MONDAY THE MODELS HAVE A FEW
TIMING DIFFERENCES WITH THE UPPER LEVEL WAVES THAT MOVE THROUGH THE
AREA AND THEREFORE TIMING THUNDERSTORMS IS MORE OF A CHALLENGE.
TEMPERATURES WILL BE THE WARMEST SUNDAY THROUGH TUESDAY THEN SLOWLY
COOL OFF TOWARD THE END OF THE WEEK. TEMPERATURES SHOULD STILL
REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 540 AM CDT SAT MAY 25 2013
TSTMS CONTINUE IN THE VICINITY OF KGRI EARLY THIS MORNING. THIS
INITIAL ROUND OF CONVECTION WILL END THIS MORNING WITH
REDEVELOPMENT OF STORMS FORECAST THIS AFTN AND EVENING. LOOK FOR
VARIABLE WINDS TO TRANSITIION SOUTHERLY TODAY...BUT WILL BE
VARIABLE/GUSTY IN VCNTY OF STORMS. CIGS/VSBYS WILL MAINLY BE VFR BUT
WILL DROP TO MVFR AND POTENTIALLY NEAR IFR DURING TSTM ACTIVITY.
SEVERE STORMS ARE POSSIBLE LATER TODAY/TONIGHT WITH LARGE
HAIL/DAMAGING WINDS/HEAVY RAINFALL THE MAIN HAZARDS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...JCB
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1239 PM CDT SAT MAY 25 2013
.UPDATE...
ISSUED AT 1239 PM CDT SAT MAY 25 2013
BASED ON LATEST MESOANALYSIS...ADDED A SLIGHT CHANCE THIS
AFTERNOON FOR WESTERN CWA IN SOUTH CENTRAL SOUTH DAKOTA. LATEST
SURFACE PLOT SHOWS THE NORTHWARD MOVING WARM FRONT NOW LOCATED
FROM NORTH OF RAPID CITY...TO NORTH OF ALLIANCE/O`NEILL
NEBRASKA...AND SOUTHEAST THROUGH SE NEBRASKA. CU ALSO DEVELOPING
BETWEEN KIEN/KVTN WITH SURFACE HEATING. LATEST SPC MESOANALYSIS
SHOWS AXIS OF LITTLE CIN AND SBCAPE OF 1500+ J/KG STRETCHED ACROSS
SOUTH CENTRAL SOUTH DAKOTA. WITH DAYTIME HEATING AND WEAK VORT
MAX IN FLOW ALOFT APPROACHING...ISOLATED CELL INITIATION IS
POSSIBLE THIS AFTERNOON...ALTHOUGH MUCH OF THE INITIATION IS
EXPECTED OUT IN WESTERN SODAK WITH STRONGER SHORT WAVE AND HIGHER
INSTABILITY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT SAT MAY 25 2013
THUNDERSTORM COMPLEX OVER NEBRASKA OVERNIGHT CONTINUES EARLY THIS
MORNING. SEEING SHOWERS AND STORMS BEGINNING TO EXPAND ACROSS
NORTHWEST IOWA AS WELL AS LOW LEVEL THETAE ADVECTION INCREASES. HIGH
RES MODEL SUITE LOOK TO HAVE A PRETTY GOOD HANDLE ON THIS ACTIVITY.
EXPECT IT TO CONTINUE THIS MORNING AND POSSIBLY EXPAND A BIT FURTHER
NORTH INTO PORTIONS OF SOUTHWEST MINNESOTA. LOWERED POPS ACROSS
SOUTHEAST SOUTH DAKOTA...AS ALL INDICATIONS ARE THAT THESE STORMS
WILL NOT DEVELOP NORTHWEST OF THEIR CURRENT LOCATION. MOST OF THE
STORMS SHOULD BE EAST OF THE CWA BY 16Z. MAIN IMPACTS WILL BE
BRIEFLY HEAVY RAIN AND POSSIBLY SMALL HAIL WITH THESE CELLS...AS
EFFECTIVE SHEAR AND CAPE ARE TOO LOW FOR ANY SEVERE THREAT. MUCH OF
THE AFTERNOON SHOULD THEN BE DRY ACROSS THE CWA WITH AN AREA OF
SUBSIDENCE LIKELY BEHIND THIS MORNINGS SHORTWAVE. WARM FRONTAL
BOUNDARY WILL POSITION ITSELF SOUTH OF THE MISSOURI RIVER THIS
AFTERNOON. HRRR AND RAP TRY TO BREAK THE CAP THEIR THIS
AFTERNOON...BUT BOTH THESE MODELS SEEM A BIT OVERDONE WITH DEWPOINTS
AND INSTABILITY. FEEL MORE LIKELY SCENARIO IS ACTIVITY WAITS FOR THE
LOW LEVEL JET TO KICK IN AFTER 0Z BEFORE IT GETS GOING.
OTHER ISSUE TODAY IS CLOUD COVER AND HIGH TEMPERATURES.
INTERESTINGLY THE HRRR AND RAP ARE COMPLETE OPPOSITE OF EACH
OTHER...GIVING AROUND A 20 DEGREE DIFFERENCE IN HIGHS...WITH THE RAP
HAVING MORE STRATUS AND COOLER TEMPERATURES. THE GEM AND ECMWF SIDE
CLOSER TO THE RAP...WITH THE NAM IN BETWEEN. SINCE THE AREAL
COVERAGE OF LOW STRATUS IS CURRENTLY LESS THAN EXPECTED...DID GO
AHEAD AND RAISE HIGHS SEVERAL DEGREES FOR TODAY IN OUR CENTRAL AND
WEST. ALSO THE HRRR HAS A GOOD HANDLE ON THE CURRENT SITUATION...SO
ONE WOULD THINK ITS SHORT RANGE FORECAST SHOULD BE SOMEWHAT
RELIABLE...AND IT HAS CONSISTENTLY BEEN WARM FOR TODAY. LOWERED
HIGHS A FEW IN THE EAST WHERE IT IS RAINING...AND WHERE STRATUS
SHOULD INDEED HOLD IN FOR MUCH OF THE DAY. AGAIN THIS IS A PRETTY
LOW CONFIDENCE TEMPERATURE FORECAST FOR ANYWHERE EAST OF THE JAMES
RIVER. BUT FEEL GOING FORECAST IS A DECENT STARTING POINT...WITH THE
DAY SHIFT LIKELY HAVING TO ADJUST UP OR DOWN DEPENDING ON CLOUD
COVER TRENDS.
QUIET SHORT TERM CONDITIONS FROM THE AFTERNOON HOURS SHOULD TURN
QUICKLY TO MORE STORMY CONDITIONS OVERNIGHT. GAVE A FAIR AMOUNT
OF CREDIT TO THE CONSISTENCY OF THE 00Z HIGH RESOLUTION NAMDNG5
AND WRF-ARW SOLUTIONS...WHICH FIT THE OVERALL CONCEPTUAL MODEL FOR
CONVECTIVE INITIATION TONIGHT. BOUNDARY FROM CURRENT NIGHT MCS
WILL BE FESTERING AND DRIFTING NORTHWARD...WITH LIKELY 1000 TO
1500 J/KG ELEVATED CAPE LIFTED FROM 1 TO 1.5 KM AGL. AS 35 TO 40
KNOT LOW LEVEL JET DEVELOPS TONIGHT THROUGH THE CENTRAL PLAINS...
SHOULD BECOME ENOUGH TO INITIATE ELEVATED THUNDERSTORMS NEAR/NORTH
OF THE BOUNDARY WHICH WILL BE DRIFTING NORTHWARD OF INTERSTATE 80
DURING THE EVENING HOURS. EFFECTIVE SHEAR IN AREAS NORTH OF THE
BOUNDARY WILL BE VERY CONCENTRATED IN THE 1-3KM LAYER WITH STRONGEST
WINDS IN LOW LEVELS AND WEAKENING MID LEVEL WINDS ROUGHLY 20-30
KNOTS...WITH LESSER DEEP LAYER SHEAR CONTRIBUTIONS FROM ABOVE. ALL
SUGGEST AT LEAST A MINIMAL THREAT FOR ISOLATED LARGER HAIL OR
DAMAGING WINDS THROUGH THE MISSOURI RIVER CORRIDOR AND LIFTING
SOMEWHAT NORTHWARD THROUGH 066-08Z. OTHER SIGNIFICANT CONVECTIVE
INITIATION IS LIKELY TO OCCUR BACK THROUGH THE WESTERN HIGH PLAINS
WHERE STRONGER SHEAR EXISTS WITH A BIT STRONGER MID LEVEL WINDS
TO AROUND 25 KNOTS...AS WELL AS THE DEEP UPSLOPE TRANSPORT OF MOISTURE
TO RESULT IN STRONGER INSTABILITY. EVENTUALLY...WHEN SUPERCELL MOTIONS
WHICH WILL TAKE ACTION MORE SOUTHWARD THAN EAST START TO EASE...AND
LOW LEVEL JET VEERS EASTWARD...WILL FIND A MORE LINEAR MCS LIKELY
TAKING SHAPE. MANY HI RES MODELS SUGGEST THIS MCS WILL ZIPPER DOWN
THE LOCATION OF THE WARM ADVECTION WING SPREADING NORTHWARD...MOVING
TOWARD EAST CENTRAL SD AND SOUTHWEST MN LATE NIGHT. SEVERE THREAT
WITH THIS FEATURE WOULD SEEM TO BE SOMEWHAT LOWER...BUT LIKELY TO
GET SOME GUSTY WINDS AND AREAS OF HEAVY RAINFALL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 430 AM CDT SAT MAY 25 2013
MCS EXPECTED TO WEAKEN AND SHIFT EAST ON SUNDAY...AND WITH MID
LEVEL FORCING SHOWING TENDENCY TO FORCE SUBSIDENCE AROUND
MIDDAY...AGAIN EXPECT THAT MUCH OF THE DAYTIME PERIOD WILL
PROBABLY END UP PRECIPITATION FREE. HOWEVER...CLOUDS LIKELY TO
PERSIST WITH STRATUS DEVELOPING IN WAKE OF SYSTEM. MOST LIKELY TO
GET BREAKS THROUGH THE WESTERN AND SOUTHERN CWA DURING THE
AFTERNOON...AND HAVE PUSHED EXPECTED TEMPS TO NEAR 80 THERE...
WHILE MORE MID TO UPPER 60S LINGER IN THE FAR EAST. RESULT OF THIS
WILL BE GENERATION OF DECENT POTENTIAL INSTABILITY OF 1500-2000
J/KG ACROSS THE AREA...WITH WEAKEST OF THE CAPPING INVERSION NEAR
THE MISSOURI RIVER CORRIDOR. SHEAR BECOMES A BIT MORE DISTRIBUTED
THROUGH THE EFFECTIVE LAYER...AND FAIRLY CLOSE TO THOSE VALUES
FROM THIS EVENING FROM 30 TO 35 KNOTS. A FEW MORE SEVERE STORMS
WOULD BE POSSIBLE MAINLY THROUGH THE SOUTHWEST HALF OF THE AREA
DURING THE LATER AFTERNOON AND EVENING HOURS...AS INITIATION
LIKELY TO BE A RESULT OF WEAK IMPULSE SLIDING UP BACK SIDE OF
RIDGE IN THE LATER AFTERNOON AND EARLY EVENING.
THE FURTHER ONE GOES INTO THE FORECAST...THE LESS RELIABLE ANY
GUIDANCE BECOMES GIVEN THE ABUNDANCE OF CONVECTION...AND THE
INCREASINGLY GREAT UNCERTAINTY AS TO WHERE CRITICAL BOUNDARIES MAY
LIE. ONE THING FOR SURE...GIVEN THE CLOSED LOW ACROSS THE WESTERN
U.S. AND THE SOUTHWEST FLOW ALOFT...DIFFICULT TO PINPOINT ANY TIME
FROM MONDAY ON THAT ONE COULD SAY THERE WAS ABSOLUTELY NO CHANCE
FOR PRECIPITATION...BUT ON THE SAME FRONT IT CERTAINLY WILL NOT BE
AN ALL TIME WASHOUT WITH MANY BREAKS DEFINED ON THE MESOSCALE.
MEMORIAL DAY AND MONDAY NIGHT WILL PLACE THE AREA ON THE SOUTHERN
FLANK OF A COUPLE OF WAVES MOVING OVER THE RIDGE...SO LIKELY TO
HAVE ENHANCEMENT OF PRECIPITATION IN THE NOCTURNALLY FAVORED
PERIODS. WHILE A FEW SEVERE STORMS ARE AGAIN WELL WITHIN
REASON...HIGH PRECIPITABLE WATER AND FAIRLY SLOW MOVING WIND
PROFILES BRING THE CONCERN OF AREAS OF HEAVY RAINFALL...AT THIS
RANGE HARD TO DEFINE. AT THE MOMENT...THE PROSPECT FOR MORE
SIGNIFICANT CONVECTION AND SEVERE WEATHER WOULD APPEAR TO BE LATE
DAY WEDNESDAY INTO THURSDAY...AS DEEP WESTERN CLOSED LOW KICKS
STRONGER JET ENERGY INTO THE PLAINS. MOISTURE THROUGH LOWER LEVELS
/THUS INSTABILITY/ WILL CONTINUE TO BENEFIT FROM PERSISTENT
SOUTHERLY FLOW. TEMPERATURES WILL LIKELY GRAVITATE TO SOMEWHAT
ABOVE NORMAL READINGS THROUGH THE UPCOMING WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1239 PM CDT SAT MAY 25 2013
MVFR CIGS ACROSS SW MN AND NW IA DID ADVECT INTO THE FSD/SUX TAF
SITES THIS MORNING WITH ESE LOW LEVEL FLOW IN PLACE. EXPECT MVFR
CIGS TO CONTINUE THROUGH THIS AFTERNOON WITH THE EDGE RIGHT AT FSD
POSSIBLY WAVERING...ALTHOUGH ADDITIONAL EXPANSION OF THIS STRATUS
IS NOT EXPECTED TOWARD HON UNTIL LATER THIS EVENING. EXPECTING
CONVECTION TO DEVELOP THIS EVENING ALONG THE WARM FRONT EXTENDING
ACROSS SW SD AND NE NEBRASKA THEN PUSH EAST AND NORTHEAST ACROSS
THE AREA LATE EVENING AND OVERNIGHT. IN ADDITION...LOW LEVEL
MOISTURE WILL CONTINUE TO INCREASE WITH ...RESULTING IN IFR CIGS
WITH SOME AREAS OF HAZE LIKELY. BY EARLY MORNING /2Z/ CONVECTION
SHOULD BE EXITING THE AREA...ALTHOUGH IFR/MVFR CIGS ARE EXPECTED
TO PERSIST THROUGH MID MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...CHAPMAN/CHENARD
LONG TERM...CHAPMAN
AVIATION...
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
609 PM CDT SAT MAY 25 2013
.DISCUSSION...SEE 00Z AVIATION DISCUSSION.
&&
.AVIATION...MVFR CONDITIONS ARE EXPECTED TO DEVELOP AGAIN AFTER
SUNSET...STARTING AT KCRP AND KALI BETWEEN 03Z-04Z...THEN AT KVCT
ABT 06Z...WITH MVFR CIGS AT KLRD BFR 12Z. VFR CONDITIONS SHOULD
DEVELOP AOA 16Z AREA-WIDE. CONCERNING THUNDER/SHRA IN TAFS...ONLY
HAVE THAT IN KVCT FOR NOW ENDING BY 03Z. THINK ANY OTHER
CONVECTION TONIGHT WILL BE AWAY FROM TERMINALS...AND ANY WHICH MAY
DEVELOP OVERNIGHT WILL BE TOO ISOLATED. CONCERNING WINDS...
SOUTHEAST WINDS WILL TAPER OFF TONIGHT...WITH INCREASING WINDS
WITH GUSTS AROUND 18Z...EXCEPT AT KLRD WHERE WINDS WILL BE SE WITH
GUSTS LIMITED IF ANY.
&&
.PREV DISCUSSION... /ISSUED 420 PM CDT SAT MAY 25 2013/
SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)...ACTIVE AFTERNOON WITH A
WEAK PATTERN CONTINUES. GOOD CAPE...BUT MARGINAL LAPSE RATES AND
WEAK SHEAR...BUT CONTINUE TO HAVE STORMS DEVELOP...A FEW PRODUCING
BRIEF FUNNEL CLOUDS OR TORNADOES. FLOOD CONCERNS ARE DECREASING AS
STORMS ARE MOVING BETTER THAN EARLIER IN THE DAY...AND NOT
TRAINING.
INITIAL VORT MAX CURRENTLY INTO NORTHEAST PORTIONS OF OUR FORECAST
AREA BUT RUC GUIDANCE SHOWS ADDITIONAL VORT MAX COMING ACROSS
OVERNIGHT. HAVE INCREASE POPS TO 30 OVERNIGHT...BUT SORT OF A
HEDGE BET AT THIS POINT AS MESO MODELS ARENT SHOWING A WHOLE LOT.
IF WE GET CONVECTION TO RE FIRE WITH THIS VORT MAX COULD BECOME
ANOTHER MORE WIDE SPREAD EVENT OVERNIGHT. WILL KEEP ISOLATED
SHOWERS AND STORMS IN THE FORECAST FOR TOMORROW AS WEAK SHORTWAVES
CONTINUE TO AFFECT THE AREA. BY SUNDAY AFTERNOON THINGS SHOULD
QUIET DOWN WITH PRECIP MOVING OUT OF THE AREA. COULD EVEN SEE SOME
BREAKS IN THE CLOUDS BY THE AFTERNOON. MILD MIN TEMPS AND WARM
HIGHS CONTINUE.
LONG TERM...(MONDAY THROUGH FRIDAY)...DID NOT MAKE MANY CHANGES
TO THE EXTENDED PART OF THE FORECAST. UPPER LEVEL RIDGE WILL BUILD
IN FOR MONDAY WITH DRIER AIR ACROSS THE AREA. TEMPERATURES WILL
REBOUND FOR THE EARLY PART OF THE WEEK WITH UPPER 90S OUT WEST TO
UPPER 80S OVER THE VICTORIA CROSSROADS. RIDGE WILL BEGIN TO SHIFT
EASTWARD TUESDAY INTO WEDNESDAY. MODELS NOW INDICATE UPPER TROUGH
MOVING INTO THE FOUR CORNERS WEDNESDAY AND INTO THE PLAINS WEDNESDAY
NIGHT. MOISTURE DOES INCREASE BY WEDNESDAY OVER THE RIO GRANDE
PLAINS BUT BELIEVE ATMOSPHERE MAY BE CAPPED...SO WILL CONTINUE WITH
POPS BELOW MENTIONABLE LEVELS. LEFT INHERITED LOW END POPS IN FOR
THURSDAY FOR THE TIME BEING...BUT CAPPING COULD BE AN ISSUE THIS DAY
AS WELL. ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
EXTENDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 76 89 73 88 75 / 20 20 10 10 10
VICTORIA 73 89 71 88 73 / 20 20 10 10 10
LAREDO 76 93 76 97 75 / 20 20 10 10 10
ALICE 72 90 72 91 74 / 20 20 10 10 10
ROCKPORT 76 86 76 86 76 / 20 20 10 10 10
COTULLA 72 92 72 93 73 / 20 20 10 10 10
KINGSVILLE 74 90 73 90 75 / 20 20 10 10 10
NAVY CORPUS 76 85 76 86 77 / 20 20 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...AVIATION
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
420 PM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)...ACTIVE AFTERNOON WITH A
WEAK PATTERN CONTINUES. GOOD CAPE...BUT MARGINAL LAPSE RATES AND
WEAK SHEAR...BUT CONTINUE TO HAVE STORMS DEVELOP...A FEW PRODUCING
BRIEF FUNNEL CLOUDS OR TORNADOES. FLOOD CONCERNS ARE DECREASING AS
STORMS ARE MOVING BETTER THAN EARLIER IN THE DAY...AND NOT
TRAINING.
INITIAL VORT MAX CURRENTLY INTO NORTHEAST PORTIONS OF OUR FORECAST
AREA BUT RUC GUIDANCE SHOWS ADDITIONAL VORT MAX COMING ACROSS
OVERNIGHT. HAVE INCREASE POPS TO 30 OVERNIGHT...BUT SORT OF A
HEDGE BET AT THIS POINT AS MESO MODELS ARENT SHOWING A WHOLE LOT.
IF WE GET CONVECTION TO RE FIRE WITH THIS VORT MAX COULD BECOME
ANOTHER MORE WIDE SPREAD EVENT OVERNIGHT. WILL KEEP ISOLATED
SHOWERS AND STORMS IN THE FORECAST FOR TOMORROW AS WEAK SHORTWAVES
CONTINUE TO AFFECT THE AREA. BY SUNDAY AFTERNOON THINGS SHOULD
QUIET DOWN WITH PRECIP MOVING OUT OF THE AREA. COULD EVEN SEE SOME
BREAKS IN THE CLOUDS BY THE AFTERNOON. MILD MIN TEMPS AND WARM
HIGHS CONTINUE.
&&
.LONG TERM...(MONDAY THROUGH FRIDAY)...DID NOT MAKE MANY CHANGES
TO THE EXTENDED PART OF THE FORECAST. UPPER LEVEL RIDGE WILL BUILD
IN FOR MONDAY WITH DRIER AIR ACROSS THE AREA. TEMPERATURES WILL
REBOUND FOR THE EARLY PART OF THE WEEK WITH UPPER 90S OUT WEST TO
UPPER 80S OVER THE VICTORIA CROSSROADS. RIDGE WILL BEGIN TO SHIFT
EASTWARD TUESDAY INTO WEDNESDAY. MODELS NOW INDICATE UPPER TROUGH
MOVING INTO THE FOUR CORNERS WEDNESDAY AND INTO THE PLAINS WEDNESDAY
NIGHT. MOISTURE DOES INCREASE BY WEDNESDAY OVER THE RIO GRANDE
PLAINS BUT BELIEVE ATMOSPHERE MAY BE CAPPED...SO WILL CONTINUE WITH
POPS BELOW MENTIONABLE LEVELS. LEFT INHERITED LOW END POPS IN FOR
THURSDAY FOR THE TIME BEING...BUT CAPPING COULD BE AN ISSUE THIS DAY
AS WELL. ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
EXTENDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 76 89 73 88 75 / 20 20 10 10 10
VICTORIA 73 89 71 88 73 / 20 20 10 10 10
LAREDO 76 93 76 97 75 / 20 20 10 10 10
ALICE 72 90 72 91 74 / 20 20 10 10 10
ROCKPORT 76 86 76 86 76 / 20 20 10 10 10
COTULLA 72 92 72 93 73 / 20 20 10 10 10
KINGSVILLE 74 90 73 90 75 / 20 20 10 10 10
NAVY CORPUS 76 85 76 86 77 / 20 20 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
PZ/83...SHORT TERM
TB/78...LONG TERM
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
414 PM CDT SAT MAY 25 2013
.DISCUSSION...
THROUGH TONIGHT...LEFT THE EARLY AFTERNOON UPDATE FORECAST
DISCUSSION ATTACHED BELOW FOR REFERENCE AND MORE DETAILS ON THE
SHORT TERM FORECAST CONCERNS.
CHANGES FROM EARLIER DISCUSSION...THE MCV THAT WAS EXPECTED TO
DEVELOP NEAR SAN ANTONIO WAS APPARENT IN REGIONAL RADAR RETURNS
NEAR AUSTIN AND GONZALEZ AT THE TIME OF THIS DISCUSSION. ASSUMING
THAT THIS IS THE PRIMARY MID-LEVEL LOW/MCV PRODUCED BY THE
PERSISTENT SAN ANTONIO AREA CONVECTION THIS MORNING...ADJUSTED
RAIN CHANCES THIS EVENING AND OVERNIGHT IN LINE WITH ITS EXPECTED
TRAJECTORY. THE 19Z RUN OF THE RAP SEEMS TO HAVE A GOOD HANDLE ON
THE POSITION OF THIS MCV...SO GENERALLY USED THIS MODEL FOR
GUIDANCE OVER THE NEXT 12 TO 18 HRS.
THE MCV IS EXPECTED TO MOVE GENERALLY IN A NORTHEASTERLY DIRECTION
THROUGH TONIGHT...TAKING IT FROM ITS CURRENT LOCATION TO JUST
NORTHEAST OF TYLER BY SUNRISE SUNDAY. THE GFS INDICATES THAT THE
UPPER TROUGH THAT WAS ANALYZED IN THE 12Z RAOB ANALYSIS TO THE
WEST OF THE CWA WILL INTERACT WITH THIS MCV FAVORABLY AND RESULT
IN WIDESPREAD THUNDERSTORM ACTIVITY GENERALLY EAST OF I-35 AND
SOUTH OF I-20 AFTER MIDNIGHT...SPREADING NORTHEAST INTO THE
ARKLATEX AREA JUST AFTER SUNRISE. BOTH OF THESE FEATURES
EXIST...SO THIS SOLUTION IS VIABLE...HOWEVER THE FORCING FOR
ASCENT ADVERTISED BY THE GFS IS GREATLY ENHANCED BY CONVECTIVE
FEEDBACK. THAT IS...MODEL GENERATED STORMS COOL OFF LOCATIONS
DOWNSTREAM /NORTHEAST/ ALLOWING WARM AIR ADVECTION TO ARTIFICIALLY
RAMP UP RESULTING IN THE GENERATION OF MORE STORMS. IN SHORT...A
MODEL GENERATED FEEDBACK LOOP. THIS LOOP MAY VERIFY AND RESULT IN
A HEAVY RAINFALL EVENT EAST OF I-35 TO THE ARKLATEX AREA TONIGHT
THROUGH SUNDAY MORNING. HOWEVER THERE IS NOT REALLY ANY HIGH
RESOLUTION MODEL OUTPUT SUPPORT FOR THIS SOLUTION AT THIS
TIME...THEREFORE CONFIDENCE IS SOMEWHAT LOW IN A WIDESPREAD HEAVY
RAIN EVENT.
THAT SAID...MANY FACTORS ARE IN PLACE TO SUPPORT A LOCALIZED HEAVY
RAINFALL EVENT ANYWHERE STORMS EXIST OVER THE NEXT 12 TO 18 HRS.
PRECIPITABLE WATER VALUES ARE ABOVE THE 75TH PERCENTILE OF
HISTORICAL PRECIPITABLE WATER VALUES FOR THIS REGION IN LATE MAY.
MID-LEVEL LAPSE RATES ARE POOR BUT THE ENVIRONMENT IS
UNCAPPED...IN SHORT A FAVORABLE ENVIRONMENT FOR VERY TALL RAIN
SHOWERS WITH LITTLE LIGHTNING ACTIVITY AND ONLY WEAK GENERATION OF
OUTFLOW BOUNDARIES. WEAK OUTFLOW MEANS THAT STORMS CAN REMAIN IN
ONE PLACE FOR A LONGER PERIOD OF TIME INCREASING THE CHANCES FOR
TRAINING OF STORMS AND A LOCALIZED FLOODING THREAT. AT THIS TIME
WENT WITH A MENTION OF LOCALIZED HEAVY RAIN AND FLOODING IN THE
HAZARDOUS WEATHER OUTLOOK AND WORDED FORECAST.
WITH WEAK WIND SHEAR IN THIS THERMODYNAMIC ENVIRONMENT STORMS ARE
EXPECTED TO BEHAVE IN A NEARLY TROPICAL NATURE WITH EFFICIENT
RAINFALL PRODUCTION. THEREFORE CHANCES OF SEVERE WEATHER APPEAR TO
BE VERY SMALL TONIGHT. WE WILL HAVE TO KEEP A CLOSE EYE ON THE
EVOLUTION OF A LOCALIZED FLOODING EVENT...ESPECIALLY WITH MANY
PEOPLE LIKELY CAMPING OUTDOORS IN FLOOD PRONE AREAS THROUGH
TONIGHT.
SUNDAY...SUNDAY MORNING WE WILL LIKELY HAVE SOME REMNANT POCKETS
OF HEAVY RAIN ALONG A SULPHUR SPRINGS TO PALESTINE LINE...LIKELY
MOVING NORTHEAST TOWARDS THE ARKLATEX REGION THROUGHOUT THE
MORNING HOURS. FROM THE WEST...THE HRRR HAS CONSISTENTLY INDICATED
THAT A SQUALL LINE WILL ORGANIZE OVER THE SOUTHERN HIGH PLAINS/TX
PANHANDLE TONIGHT AND MOVE EAST TOWARDS OUR WESTERN CWA EARLY
SUNDAY MORNING. WE WILL HAVE TO KEEP AN EYE ON THIS...NOT SO MUCH
FROM A SEVERE WEATHER STAND POINT BUT FROM ANOTHER POTENTIAL
SOURCE FOR MCV PRODUCTION. WITH THE SAN ANTONIO AREA MCV AND
LARGER UPPER TROUGH MOVING EAST...SUBSIDENCE WILL LIKELY DOMINATE
ANY MCV MOVING OFF THE HIGH PLAINS AND THRU NORTH TX TOMORROW.
HOWEVER UNTIL WE GET SOME DRIER AIR IN OVER THE REGION CAPPING OFF
THE ATMOSPHERE FOR THUNDERSTORM DEVELOPMENT...WILL HOLD ON TO A
BROAD BRUSHED MENTION OF SHOWERS AND THUNDERSTORMS IN THE FORECAST
ACROSS ALL OF NORTH TX THROUGH SUNDAY.
NEXT WEEK...BEGINNING MONDAY A WESTERN CONUS TROUGH IS EXPECTED TO
ORGANIZE SENDING THE WEAK UPPER LEVEL RIDGE AND ENTRAPPED MCV
FEATURES OFF TO THE EAST OF THE REGION. THIS IS EXPECTED TO RESULT
IN SOUTHWEST FLOW ALOFT OVER NORTH TX ON MONDAY WHICH SHOULD HELP
TO ADVECT A RELATIVELY STOUT CAP IN PLACE OVER THE REGION BY
MONDAY AFTERNOON. THIS CAP IS EXPECTED TO HOLD IN PLACE THROUGH
THE WEEK UNLESS THE DRYLINE OR A STRONG SHORTWAVE TROUGH CAN LIFT
THE CAP AND RESULT IN THUNDERSTORM INITIATION DURING THE WEEK
AHEAD.
WE ARE EXPECTED TO HAVE RELATIVELY PERSISTENT...BREEZY SOUTH
WINDS IN PLACE BELOW THE CAP THROUGH THE WEEK. THIS WILL HELP KEEP
GOOD GULF MOISTURE IN PLACE UNDER THE CAP PROVIDING PLENTY OF
POSITIVE CAPE FOR THUNDERSTORM DEVELOPMENT IF ANYTHING CAN REMOVE
THE CAP. WITHOUT STORMS...WE WILL LIKELY SEE HIGHS HOLD IN THE
UPPER 80S WITH LOWS IN THE LOWER TO MID 70S EACH DAY. THE GFS AND
ECMWF BOTH INDICATE THAT A STRONG SHORTWAVE TROUGH WILL MOVE OVER
THE SOUTH PLAINS WEDNESDAY THROUGH WEDNESDAY EVENING. THE ECMWF
REMAINS FURTHER SOUTH WITH THIS TROUGH WHICH IS WHAT WE WILL NEED
TO LIFT THE CAP AND RESULT IN STORMS ACROSS THE CWA WEDNESDAY
AFTERNOON AND EVENING. THE GFS INDICATES THE BEST FORCING STAYS
NORTH OF THE CWA. WENT AHEAD WITH 20 TO 30 POPS WEST OF INTERSTATE
35...CLOSEST TO THE UPPER TROUGH WEDNESDAY AFTERNOON THROUGH
WEDNESDAY NIGHT AS RESULT. REMOVED POPS THEREAFTER WITH ALL
GUIDANCE INDICATING SUBSIDENCE BEHIND THIS UPPER TROUGH ON
THURSDAY.
CAVANAUGH
&&
.PREV UPDATE FOR SHORT TERM FORECAST...
THE PRIMARY FORECAST CHALLENGE FOR THE NEXT 24 HRS IS DETERMINING
WHERE AND WHEN A MID-LEVEL LOW PRESSURE SYSTEM /MCV...CAUSED BY
PERSISTENT THUNDERSTORM ACTIVITY THAT HAS DISSIPATED/ WILL MOVE
OVER NORTH TX AND BRING US MORE THUNDERSTORM ACTIVITY. THE MID-
LEVEL LOW FROM YESTERDAYS THUNDERSTORM ACTIVITY WAS DIFFICULT TO
LOCATE THIS MORNING. 12Z UPPER AIR ANALYSIS INDICATED MID-LEVEL
CYCLONIC CIRCULATIONS FROM NORTHWEST TX SOUTH TO THE HILL COUNTRY.
IT IS POSSIBLE THAT THIS CYCLONIC SHEAR AXIS IS YESTERDAYS MID-
LEVEL LOW...BUT SHEARED APART IN THE LARGER SCALE UPPER LEVEL
RIDGE OVER THE REGION. JUST BEFORE NOON...THERE WAS A BAND OF RAIN
SHOWERS AND EMBEDDED STORMS EXTENDING FROM STEPHENVILLE SOUTH TO
THE AUSTIN AND SAN ANTONIO AREAS WHICH APPEARED TO BE ASSOCIATED
WITH THIS SHEAR AXIS.
THE MORE INTENSE THUNDERSTORMS AND RAIN SHOWERS WERE LOCATED AT
THE FAR SOUTHERN END OF THIS LINE...CAUSING WIDESPREAD FLOODING
AROUND THE CITY OF SAN ANTONIO AT THE TIME OF THIS DISCUSSION. DUE
TO THE PERSISTENCE OF INTENSE RAIN SHOWER AND THUNDERSTORM
ACTIVITY TO THE SOUTH OF THE CWA...WOULD EXPECT THAT A NEW OR
REINFORCED MID-LEVEL LOW PRESSURE SYSTEM WOULD DEVELOP AROUND SAN
ANTONIO SOMETIME TODAY. THERE HAS BEEN SOME INDICATION OF WEAK
CYCLONIC CIRCULATIONS IN THE LIGHTER RAINFALL RETURNS TO THE NORTH
OF SAN ANTONIO...IN BETWEEN TEMPLE AND AUSTIN.
MID-LEVEL LOW PRESSURE SYSTEMS ARE CREATED BY THUNDERSTORMS DUE
TO LARGE AMOUNTS OF LATENT HEAT RELEASED IN THE MIDDLE OF THE
ATMOSPHERE DUE TO WATER VAPOR CONDENSING INTO WATER DROPLETS OR
RAIN. BECAUSE THIS HAS BEEN GOING ON IN AN INTENSE FASHION NEAR
SAN ANTONIO ALL MORNING...THINK THAT A MID-LEVEL LOW PRESSURE
SYSTEM WILL LIKELY DEVELOP AROUND SAN ANTONIO /IF IT HAS NOT
ALREADY/ AND BECOME THE DOMINANT MESOSCALE FEATURE DRIVING RAIN
AND STORM CHANCES FOR NORTH TX OVER THE NEXT 24 HRS. THROUGH THIS
AFTERNOON JUST ADJUSTED POPS TO HIGHLIGHT AREAS SOUTH OF
INTERSTATE 20 AS HAVING THE HIGHEST RAIN CHANCES TODAY ASSUMING
THE SAN ANTONIO LOW MOVES SLIGHTLY EAST THROUGH 7 PM.
DID NOT REMOVE RAIN CHANCES TO THE NORTH BECAUSE THE WEAK
CYCLONIC SHEAR AXIS STILL EXISTS AS FAR NORTH AS WICHITA
FALLS...SO SOME RAIN AND THUNDERSTORM CHANCES ARE STILL WARRANTED
NORTH OF INTERSTATE 20 THIS AFTERNOON. SEVERE WEATHER CHANCES
REMAIN SMALL ACROSS ALL OF NORTH TX AS MID-LEVEL LAPSE RATES ARE
POOR DUE TO YESTERDAYS THUNDERSTORM ACTIVITY AND DEEP LAYER SHEAR
REMAINS WEAK AT THIS TIME.
CAVANAUGH
&&
.AVIATION...
/18Z TAFS/
CONCERNS...THUNDER THROUGH THE EVENING AND MVFR CIGS THROUGH THE
PERIOD.
A MESSY TAF PERIOD CONTINUES WITH LOW CONFIDENCE IN CLOUD AND
PRECIPITATION TRENDS FOR THE NEXT 18-24 HOURS. AT ALL THE TAF
AIRPORTS...SCATTERED TO BROKEN MVFR CIGS WITH BASES BETWEEN
1200-2000 FEET PERSIST. HOWEVER...IFR CIGS ARE BEING REPORTED
SOUTHWEST OF KACT WHERE LIGHT RAIN HAS PERSISTED FOR MUCH OF THE
MORNING. CEILINGS SHOULD LIFT ABOVE 2000 FEET THIS AFTERNOON AND
POSSIBLY INTO VFR CATEGORY BEFORE THE EVENING HOURS BUT THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS IN THE REGION MAY AFFECT
IMPROVING CLOUD TRENDS. MOST OF THE PRECIPITATION THIS MORNING HAS
REMAINED WEST OF THE AIRPORTS BUT RADAR INDICATES NEW DEVELOPMENT
CLOSER TO THE TAF TERMINALS. EXPECT ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS TO DEVELOP THROUGHOUT THE AFTERNOON. SHOWERS
AND THUNDERSTORMS COULD DIRECTLY IMPACT ANY OF THE AIRPORTS THIS
AFTERNOON BUT THINK KACT AS THE HIGHEST CHANCES OF BEING IMPACTS
BY CONVECTION AND INCLUDED A TEMPO FROM 19-23Z FOR TSRA. ONCE
AGAIN...EXPECT MOST OF THE CONVECTIVE ACTIVITY TO DECREASE THIS
AFTERNOON AND A FAIRLY QUIET AND DRY OVERNIGHT PERIOD...BUT WILL BE
MONITORING THE MOVEMENT OF AN UPPER LEVEL LOW OVER THE REGION FOR
ANY CHANGES TO RAIN/CONVECTIVE CHANCES. ALSO WILL BE MONITORING
FOR ANOTHER AREA OF WIDESPREAD RAIN/STORMS TO AFFECT ANY OF THE
AIRPORTS LATER TODAY. MVFR CIGS WILL LIKELY RETURN TO ALL TAF
AIRPORTS OVERNIGHT BETWEEN 09-11Z.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 69 87 69 87 70 / 30 10 5 0 0
WACO, TX 68 87 68 89 71 / 30 10 5 0 0
PARIS, TX 67 85 66 85 67 / 30 10 5 0 0
DENTON, TX 67 86 68 87 68 / 30 10 5 0 0
MCKINNEY, TX 67 85 68 87 69 / 30 10 5 0 0
DALLAS, TX 71 87 70 89 72 / 30 10 5 0 0
TERRELL, TX 67 86 68 88 70 / 30 10 5 0 0
CORSICANA, TX 67 88 68 89 70 / 30 10 5 0 0
TEMPLE, TX 67 87 68 88 70 / 20 10 5 0 0
MINERAL WELLS, TX 66 87 67 89 68 / 20 10 5 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
339 PM CDT SAT MAY 25 2013
.SHORT TERM...
MOIST UPSLOPE FLOW ACROSS EASTERN NEW MEXICO HAS ALREADY SUPPORTED
SCATTERED TSTMS FROM THE SACRAMENTOS NORTH TO SANTA ROSA. A SECOND
AREA OF INTEREST IS EVIDENT ON VIS SATELLITE ALONG THE MESCALERO
ESCARPMENT WHERE AGITATED CU HAVE RECENTLY DEVELOPED. HRRR AND
NAM-WRF BOTH PROG TSTM DEVELOPMENT ALONG THIS CU LINE BEFORE 00Z
AND CARRY IT EASTWARD TO VARIOUS DEGREES WITHIN 20 KNOTS OF
700-500MB FLOW. CONSIDERING CINH IS TRENDING NEGLIGIBLE ALONG THE
NM/TX STATE LINE AND SBCAPE IS AROUND 2K J/KG...HAVE ADDED SEVERE
MENTION TO OUR WESTERNMOST COUNTIES WHERE THIS ACTIVITY WILL LIKELY
PEAK IN INTENSITY BEFORE DIMINISHING THEREAFTER AS THE MIXING LAYER
DECOUPLES. LITTLE/NO BACKGROUND SUPPORT MAY FURTHER LIMIT THE
CHANCES OF THIS PERSISTING OVER THE REMAINDER OF THE SOUTH
PLAINS...BUT WILL KEEP SOME ISOLATED MENTION THROUGH 06Z.
SUNDAY WILL SEE IMPROVED W-SWLY FLOW OVERSPREAD THE REGION RESULTING
IN THE DRYLINE MIXING OUT OF NEW MEXICO AND STALLING SOMEWHERE OVER
THE WESTERN 1/3 OF THE CWA. ALBEIT MODEST...AN ADDITIONAL INFLUX OF
GULF MOISTURE BY EARLY SUNDAY IS PROGGED TO SECURE HIGHER SBCAPES
GENERALLY AROUND 3500 J/KG ALONG THE DRYLINE WITH EVEN EXTREME
VALUES IN THE ROLLING PLAINS...HOWEVER THE LATTER IS SHOWN TO REMAIN
CAPPED AND TOO FAR REMOVED FROM THE DRYLINE. NO DISCERNIBLE SHORT
WAVE TROUGHS ARE PROGGED...BUT AS IS THE CASE TODAY DEEP MIXING
SHOULD PROVE MORE THAN ADEQUATE FOR AT LEAST ISO TSTMS. WINDOW FOR
SUPERCELLS WILL BE OPENED 0-6KM BULK SHEAR VECTORS RISE TO NEARLY 40
KNOTS AND MAINTAIN A PERPENDICULAR ORIENTATION TO THE DRYLINE.
ROBUST CAPE IN THE HAIL GROWTH LAYER COMBINED WITH RELATIVELY HIGH
LCL VALUES WILL OPEN THE WINDOW FOR SOME VERY LARGE HAIL AND DMGG
DOWNBURSTS. MOST HIGH TEMPS WERE KEPT A FEW DEGREES ABOVE
MOS...PARTICULARLY WEST OF THE DRYLINE WHERE OUR HIGHEST ELEVATIONS
COULD END UP WITH THE HOTTEST VALUES FOR THE DAY.
&&
.LONG TERM...
HIGH AMPLITUDE RIDGE ORIENTED FROM THE BIG BEND TO THE WESTERN GREAT
LAKES THENCE WELL INTO CENTRAL CANADA WILL CONTINUE ITS SLOW
EASTWARD PROGRESSION AS A COUPLE OF STORM SYSTEMS COME ASHORE THE
PACIFIC NORTHWEST. TOWARD MID WEEK...FLOW ACROSS WEST TEXAS WILL
STRENGTHEN AS NEGATIVELY TILTED TROUGH DEEPENS FROM THE PAC NW.
THURSDAY SHOULD SEE A RETURN TO ZONAL FLOW AS UPPER LOW SETTLES
ACROSS WYOMING THOUGH ANOTHER LOBE OF ENERGY ROTATING AROUND THE WY
SYSTEM WILL APPROACH LATE THU/EARLY FRIDAY WITH SOUTHWESTERLIES
PERSISTING THROUGH DAY 7.
WILL CONTINUE MENTION OF TSRA INTO THE EVENING HOURS ON SUNDAY WITH
CONDITIONS SETTLING AFTER SUNSET. DRYLINE SHOULD PUSH INTO NEW
MEXICO OVERNIGHT THEN TIGHTEN UP AGAIN MONDAY AFTERNOON WITH
CONVECTION LOOKING MOST LIKELY EAST OF A SILVERTON TO BROWNFIELD
LINE THOUGH SOME VARIANCE WILL BE POSSIBLE GIVEN THE INFLUENCES OF
SUNDAY NIGHT/S STORMS. WEDNESDAY LOOKS TO KEEP THE DRYLINE A BIT
FURTHER WEST THUS GIVING MORE OF THE AREA A SHOT AT THE MUCH NEEDED
RAINFALL. WITH THE MORE STRONGLY DIFLUENT FLOW ON WEDNESDAY...THIS
COULD BE THE MOST PRONOUNCED OF THE SEVERE WEATHER THIS WEEK THOUGH
EACH DAY WILL HAVE SEVERE POTENTIAL. THE LONG AND SHORT OF IT IS
THAT EACH DAY OVER THE NEXT WEEK...WE WILL SEE AT LEAST SCATTERED
CONVECTION POTENTIAL EACH AFTERNOON AS THE DRYLINE SLOSHES ACROSS
THE REGION. AT PRESENT...IT WOULD APPEAR THE TORNADO THREAT THIS
WEEK WOULD BE MAXIMIZED ACROSS THE NORTHEASTERN ZONES ON WEDNESDAY.
TO THE WEST OF THE DRYLINE...ELEVATED TO LOW END CRITICAL FIRE
WEATHER CONDITIONS WILL EXIST NEARLY EVERY AFTERNOON AS MIN AFTN RH
DROPS TO THE LOWER TEENS WITH THE BREEZY WEST-OF-THE-DRYLINE WINDS.
OUR NORTHWEST HAS SEEN THE LOWEST AMOUNT OF GREEN-UP DUE TO THE LACK
OF PRECIPITATION THIS SPRING AND WHILE FUELS ARE NOT
PLENTIFUL...WHAT IS THERE WOULD BE EXPECTED TO BURN QUITE EASILY
GIVEN THE RIGHT METEOROLOGICAL CONDITIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 61 94 62 94 61 / 30 20 20 10 10
TULIA 61 94 65 94 64 / 20 20 20 20 20
PLAINVIEW 62 93 65 95 65 / 20 20 20 20 20
LEVELLAND 63 95 68 95 67 / 20 20 20 20 20
LUBBOCK 65 94 67 95 67 / 20 20 20 20 20
DENVER CITY 62 95 68 95 68 / 20 10 10 10 20
BROWNFIELD 63 95 68 96 68 / 20 20 20 20 20
CHILDRESS 68 94 67 94 67 / 10 10 10 10 20
SPUR 65 92 68 95 68 / 10 10 10 10 20
ASPERMONT 68 93 69 92 69 / 10 10 10 10 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93/26
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1247 PM CDT SAT MAY 25 2013
.AVIATION...
/18Z TAFS/
CONCERNS...THUNDER THROUGH THE EVENING AND MVFR CIGS THROUGH THE
PERIOD.
A MESSY TAF PERIOD CONTINUES WITH LOW CONFIDENCE IN CLOUD AND
PRECIPITATION TRENDS FOR THE NEXT 18-24 HOURS. AT ALL THE TAF
AIRPORTS...SCATTERED TO BROKEN MVFR CIGS WITH BASES BETWEEN
1200-2000 FEET PERSIST. HOWEVER...IFR CIGS ARE BEING REPORTED
SOUTHWEST OF KACT WHERE LIGHT RAIN HAS PERSISTED FOR MUCH OF THE
MORNING. CEILINGS SHOULD LIFT ABOVE 2000 FEET THIS AFTERNOON AND
POSSIBLY INTO VFR CATEGORY BEFORE THE EVENING HOURS BUT THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS IN THE REGION MAY AFFECT
IMPROVING CLOUD TRENDS. MOST OF THE PRECIPITATION THIS MORNING HAS
REMAINED WEST OF THE AIRPORTS BUT RADAR INDICATES NEW DEVELOPMENT
CLOSER TO THE TAF TERMINALS. EXPECT ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS TO DEVELOP THROUGHOUT THE AFTERNOON. SHOWERS
AND THUNDERSTORMS COULD DIRECTLY IMPACT ANY OF THE AIRPORTS THIS
AFTERNOON BUT THINK KACT AS THE HIGHEST CHANCES OF BEING IMPACTS
BY CONVECTION AND INCLUDED A TEMPO FROM 19-23Z FOR TSRA. ONCE
AGAIN...EXPECT MOST OF THE CONVECTIVE ACTIVITY TO DECREASE THIS
AFTERNOON AND A FAIRLY QUIET AND DRY OVERNIGHT PERIOD...BUT WILL BE
MONITORING THE MOVEMENT OF AN UPPER LEVEL LOW OVER THE REGION FOR
ANY CHANGES TO RAIN/CONVECTIVE CHANCES. ALSO WILL BE MONITORING
FOR ANOTHER AREA OF WIDESPREAD RAIN/STORMS TO AFFECT ANY OF THE
AIRPORTS LATER TODAY. MVFR CIGS WILL LIKELY RETURN TO ALL TAF
AIRPORTS OVERNIGHT BETWEEN 09-11Z.
82/JLD
&&
.UPDATE...
THE PRIMARY FORECAST CHALLENGE FOR THE NEXT 24 HRS IS DETERMINING
WHERE AND WHEN A MID-LEVEL LOW PRESSURE SYSTEM /MCV...CAUSED BY
PERSISTENT THUNDERSTORM ACTIVITY THAT HAS DISSIPATED/ WILL MOVE
OVER NORTH TX AND BRING US MORE THUNDERSTORM ACTIVITY. THE MID-
LEVEL LOW FROM YESTERDAYS THUNDERSTORM ACTIVITY WAS DIFFICULT TO
LOCATE THIS MORNING. 12Z UPPER AIR ANALYSIS INDICATED MID-LEVEL
CYCLONIC CIRCULATIONS FROM NORTHWEST TX SOUTH TO THE HILL COUNTRY.
IT IS POSSIBLE THAT THIS CYCLONIC SHEAR AXIS IS YESTERDAYS MID-
LEVEL LOW...BUT SHEARED APART IN THE LARGER SCALE UPPER LEVEL
RIDGE OVER THE REGION. JUST BEFORE NOON...THERE WAS A BAND OF RAIN
SHOWERS AND EMBEDDED STORMS EXTENDING FROM STEPHENVILLE SOUTH TO
THE AUSTIN AND SAN ANTONIO AREAS WHICH APPEARED TO BE ASSOCIATED
WITH THIS SHEAR AXIS.
THE MORE INTENSE THUNDERSTORMS AND RAIN SHOWERS WERE LOCATED AT
THE FAR SOUTHERN END OF THIS LINE...CAUSING WIDESPREAD FLOODING
AROUND THE CITY OF SAN ANTONIO AT THE TIME OF THIS DISCUSSION. DUE
TO THE PERSISTENCE OF INTENSE RAIN SHOWER AND THUNDERSTORM
ACTIVITY TO THE SOUTH OF THE CWA...WOULD EXPECT THAT A NEW OR
REINFORCED MID-LEVEL LOW PRESSURE SYSTEM WOULD DEVELOP AROUND SAN
ANTONIO SOMETIME TODAY. THERE HAS BEEN SOME INDICATION OF WEAK
CYCLONIC CIRCULATIONS IN THE LIGHTER RAINFALL RETURNS TO THE NORTH
OF SAN ANTONIO...IN BETWEEN TEMPLE AND AUSTIN.
MID-LEVEL LOW PRESSURE SYSTEMS ARE CREATED BY THUNDERSTORMS DUE
TO LARGE AMOUNTS OF LATENT HEAT RELEASED IN THE MIDDLE OF THE
ATMOSPHERE DUE TO WATER VAPOR CONDENSING INTO WATER DROPLETS OR
RAIN. BECAUSE THIS HAS BEEN GOING ON IN AN INTENSE FASHION NEAR
SAN ANTONIO ALL MORNING...THINK THAT A MID-LEVEL LOW PRESSURE
SYSTEM WILL LIKELY DEVELOP AROUND SAN ANTONIO /IF IT HAS NOT
ALREADY/ AND BECOME THE DOMINANT MESOSCALE FEATURE DRIVING RAIN
AND STORM CHANCES FOR NORTH TX OVER THE NEXT 24 HRS. THROUGH THIS
AFTERNOON JUST ADJUSTED POPS TO HIGHLIGHT AREAS SOUTH OF
INTERSTATE 20 AS HAVING THE HIGHEST RAIN CHANCES TODAY ASSUMING
THE SAN ANTONIO LOW MOVES SLIGHTLY EAST THROUGH 7 PM.
DID NOT REMOVE RAIN CHANCES TO THE NORTH BECAUSE THE WEAK
CYCLONIC SHEAR AXIS STILL EXISTS AS FAR NORTH AS WICHITA
FALLS...SO SOME RAIN AND THUNDERSTORM CHANCES ARE STILL WARRANTED
NORTH OF INTERSTATE 20 THIS AFTERNOON. SEVERE WEATHER CHANCES
REMAIN SMALL ACROSS ALL OF NORTH TX AS MID-LEVEL LAPSE RATES ARE
POOR DUE TO YESTERDAYS THUNDERSTORM ACTIVITY AND DEEP LAYER SHEAR
REMAINS WEAK AT THIS TIME.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 347 AM CDT SAT MAY 25 2013/
RADAR/SATELLITE LOOP INDICATES THAT THE WEAK MID LEVEL LOW IS
LIKELY LOCATED NEAR ABILENE AND 00Z 500MB ANALYSIS CONFIRMS IT IS
WARM-CORE IN NATURE. AS IS OFTEN THE CASE WITH WARM-CORE
LOWS...CONVECTION IS FIRING BEFORE SUNRISE ACROSS THE HILL
COUNTRY WITHIN A WEAK LOW LEVEL JET AXIS WHERE THETA-E ADVECTION
AND OROGRAPHIC LIFT ARE OCCURRING. SHORT-TERM MODELS SUCH AS THE
HRRR AND RUC SUGGEST THAT SCATTERED CONVECTION WILL CONTINUE TO
EXPAND NORTHWARD FROM CENTRAL TEXAS INTO THE WESTERN ZONES DURING
THE MORNING HOURS. THE GFS APPEARS TO BE SUFFERING FROM GRID SCALE
CONVECTIVE FEEDBACK WHICH IS RESULTING IN VERY HIGH QPF AND
CONTAMINATED MASS FIELDS...THUS THE GFS WILL NOT BE USED IN THE
SHORT-TERM. THE NAM SEEMS TO BE MATCHING CURRENT TRENDS AND SHORT-
TERM MODELS WELL AND THEREFORE IT GIVES CONFIDENCE TO RAISE POPS
TODAY. WE EXPECT THE BEST COVERAGE OF CONVECTION IN THE WESTERN
ZONES THIS MORNING. SCATTERED CONVECTION WILL BUILD/EXPAND
EASTWARD INTO THE EASTERN ZONES DURING THE MIDDAY/AFTERNOON HOURS.
THE AIRMASS OVER THE EASTERN ZONES WILL BE A BIT MORE UNSTABLE DUE
TO BETTER INSOLATION AND A COUPLE OF STRONG STORMS WITH GUSTY
WINDS WILL BE POSSIBLE...BUT DUE TO WEAK SHEAR THE SEVERE THREAT
IS LOW. HIGHS TODAY IN THE WESTERN ZONES WILL ONLY BE IN THE UPPER
70S TO LOW 80S DUE TO CLOUDS/RAIN...WITH HIGHS IN THE EASTERN
ZONES REACHING THE MID 80S. SCATTERED CONVECTION WILL CONTINUE
INTO THE EVENING HOURS BEFORE DISSIPATING WITH LOSS OF HEATING.
THE WARM CORE MID LEVEL LOW WILL BE EXITING THE REGION TO THE
NORTHEAST TONIGHT...AND THEREFORE THE RAIN CHANCES WILL COME TO AN
END. EXPECT A DRY SUNDAY WITH TEMPERATURES REBOUNDING INTO THE
MID-UPPER 80S AREA WIDE. AS AN UPPER LEVEL TROUGH DEVELOPS ACROSS
THE INTER-MOUNTAIN WEST...A SURFACE LOW WILL DEEPEN IN THE HIGH
PLAINS MONDAY. THIS WILL BRING BREEZY SOUTH WINDS TO THE REGION
MONDAY WHICH WILL LIKELY PERSIST THROUGH THE WEEK. LOW TEMPS WILL
WARM INTO THE 70S AREA WIDE BY MIDWEEK WITH HIGHS GENERALLY IN THE
MID 80S EAST TO LOW 90S WEST. THE SOUTHWEST FLOW ABOVE THE
SURFACE WILL BRING A THERMAL INVERSION INTO THE AREA. THUS THE
FORECAST LOOKS DRY UNLESS/UNTIL FORCING ARRIVES TO WEAKEN THE CAP.
MODEL GUIDANCE REMAINS IN POOR TO FAIR AGREEMENT REGARDING THE
EVOLUTION/EJECTION OF THE WEST COAST UPPER TROUGH MID-LATE WEEK.
THE ECMWF CONTINUES TO SHOW A VERY NEGATIVELY TILTED TROUGH
SWINGING THROUGH THE REGION LATE WEDNESDAY AND THURSDAY WHICH
WOULD BODE WELL FOR RAIN. BUT IT CONTINUES TO BE THE ONLY MODEL
THAT SHOWS THE TROUGH EJECTION LIKE THIS...AND FRANKLY THE 500MB
PATTERN IT PRESENTS JUST DOES NOT LOOK REALISTIC. IF IT WERE NOT
FOR THE ECMWF BEING THE BETTER OF THE LONG RANGE MODELS...I WOULD
DISCOUNT IT ALTOGETHER AND SHOW A DRY FORECAST ON THURSDAY...BUT
FOR NOW HAVE RETAINED THE SLIGHT CHANCE POPS. THE GFS/UKMET/GEM
FORECASTS SHOW THAT THE UPPER ENERGY NEEDED TO BREAK THE CAP WILL
LIKELY REMAIN WELL NORTHWEST OF THE REGION. FURTHERMORE...THE
DRYLINE ALSO LOOKS LIKE IT WILL REMAIN TOO FAR TO THE WEST...WITH
THE GFS SHOWING IT AS FAR WEST AS THE TX PANHANDLE. STORM MOTIONS
WILL GENERALLY BE NORTHEAST AND THIS MEANS STORMS WOULD NOT EVEN
HAVE A CHANCE TO PROPAGATE INTO THE CWA EITHER. SO IN SUMMARY THE
RAIN CHANCES ON THURSDAY AT THIS POINT ARE HINGING ON THE ECMWF
BEING CORRECT...AND THIS MAY BE A BIT OF A LONG SHOT.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 84 69 87 69 87 / 40 30 10 5 0
WACO, TX 83 68 87 68 89 / 50 30 10 5 0
PARIS, TX 83 67 85 66 85 / 30 30 10 5 0
DENTON, TX 84 67 86 68 87 / 40 30 10 5 0
MCKINNEY, TX 84 67 85 68 87 / 30 30 10 5 0
DALLAS, TX 85 71 87 70 89 / 40 30 10 5 0
TERRELL, TX 84 67 86 68 88 / 40 30 10 5 0
CORSICANA, TX 84 67 88 68 89 / 40 30 10 5 0
TEMPLE, TX 82 67 87 68 88 / 60 20 10 5 0
MINERAL WELLS, TX 81 66 87 67 89 / 40 20 10 5 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
82/69
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1213 PM CDT SAT MAY 25 2013
.UPDATE...
THE PRIMARY FORECAST CHALLENGE FOR THE NEXT 24 HRS IS DETERMINING
WHERE AND WHEN A MID-LEVEL LOW PRESSURE SYSTEM /MCV...CAUSED BY
PERSISTENT THUNDERSTORM ACTIVITY THAT HAS DISSIPATED/ WILL MOVE
OVER NORTH TX AND BRING US MORE THUNDERSTORM ACTIVITY. THE MID-
LEVEL LOW FROM YESTERDAYS THUNDERSTORM ACTIVITY WAS DIFFICULT TO
LOCATE THIS MORNING. 12Z UPPER AIR ANALYSIS INDICATED MID-LEVEL
CYCLONIC CIRCULATIONS FROM NORTHWEST TX SOUTH TO THE HILL COUNTRY.
IT IS POSSIBLE THAT THIS CYCLONIC SHEAR AXIS IS YESTERDAYS MID-
LEVEL LOW...BUT SHEARED APART IN THE LARGER SCALE UPPER LEVEL
RIDGE OVER THE REGION. JUST BEFORE NOON...THERE WAS A BAND OF RAIN
SHOWERS AND EMBEDDED STORMS EXTENDING FROM STEPHENVILLE SOUTH TO
THE AUSTIN AND SAN ANTONIO AREAS WHICH APPEARED TO BE ASSOCIATED
WITH THIS SHEAR AXIS.
THE MORE INTENSE THUNDERSTORMS AND RAIN SHOWERS WERE LOCATED AT
THE FAR SOUTHERN END OF THIS LINE...CAUSING WIDESPREAD FLOODING
AROUND THE CITY OF SAN ANTONIO AT THE TIME OF THIS DISCUSSION. DUE
TO THE PERSISTENCE OF INTENSE RAIN SHOWER AND THUNDERSTORM
ACTIVITY TO THE SOUTH OF THE CWA...WOULD EXPECT THAT A NEW OR
REINFORCED MID-LEVEL LOW PRESSURE SYSTEM WOULD DEVELOP AROUND SAN
ANTONIO SOMETIME TODAY. THERE HAS BEEN SOME INDICATION OF WEAK
CYCLONIC CIRCULATIONS IN THE LIGHTER RAINFALL RETURNS TO THE NORTH
OF SAN ANTONIO...IN BETWEEN TEMPLE AND AUSTIN.
MID-LEVEL LOW PRESSURE SYSTEMS ARE CREATED BY THUNDERSTORMS DUE
TO LARGE AMOUNTS OF LATENT HEAT RELEASED IN THE MIDDLE OF THE
ATMOSPHERE DUE TO WATER VAPOR CONDENSING INTO WATER DROPLETS OR
RAIN. BECAUSE THIS HAS BEEN GOING ON IN AN INTENSE FASHION NEAR
SAN ANTONIO ALL MORNING...THINK THAT A MID-LEVEL LOW PRESSURE
SYSTEM WILL LIKELY DEVELOP AROUND SAN ANTONIO /IF IT HAS NOT
ALREADY/ AND BECOME THE DOMINANT MESOSCALE FEATURE DRIVING RAIN
AND STORM CHANCES FOR NORTH TX OVER THE NEXT 24 HRS. THROUGH THIS
AFTERNOON JUST ADJUSTED POPS TO HIGHLIGHT AREAS SOUTH OF
INTERSTATE 20 AS HAVING THE HIGHEST RAIN CHANCES TODAY ASSUMING
THE SAN ANTONIO LOW MOVES SLIGHTLY EAST THROUGH 7 PM.
DID NOT REMOVE RAIN CHANCES TO THE NORTH BECAUSE THE WEAK
CYCLONIC SHEAR AXIS STILL EXISTS AS FAR NORTH AS WICHITA
FALLS...SO SOME RAIN AND THUNDERSTORM CHANCES ARE STILL WARRANTED
NORTH OF INTERSTATE 20 THIS AFTERNOON. SEVERE WEATHER CHANCES
REMAIN SMALL ACROSS ALL OF NORTH TX AS MID-LEVEL LAPSE RATES ARE
POOR DUE TO YESTERDAYS THUNDERSTORM ACTIVITY AND DEEP LAYER SHEAR
REMAINS WEAK AT THIS TIME.
CAVANAUGH
&&
.AVIATION...
THE WEAK UPPER LOW OVER THE REGION WILL AGAIN RESULT IN AREAS OF
SHRA/TSRA THROUGHOUT THE DAY. RADAR MOSAIC SHOWS THIS ACTIVITY
CURRENTLY FROM THE KAUS/KSAT AREA NORTHWARD TO THE RED RIVER. AS
THE DAY PROGRESSES EXPECT CONVECTION TO INCREASE IN COVERAGE WITH
SOME AFFECTING THE TAF SITES MAINLY THIS AFTERNOON. AS THE UPPER
LOW MOVES FARTHER NORTHEAST TONIGHT...SOME ACTIVITY WILL LINGER
OVER THE AREA BUT IT SHOULD BE MOSTLY -RA AFTER 26/03Z.
AIRPORT OPERATIONS WILL BE AFFECTED BY LIGHTNING STRIKES...WET
RUNWAYS AND REDUCTIONS IN CIGS AND VIS DURING CONVECTION. KDFW
OPERATIONS SHOULD EXPECT AN AIRPORT WEATHER WARNING TO BE ISSUED
LATER TODAY AS LIGHTNING NEARS THE AIRPORT.
FOR THIS TAF CYCLE...MVFR CIGS ARE ON GOING AT KACT BUT THEY
SHOULD ARRIVE AT THE METROPLEX AIRPORTS 13-14Z. CIGS WILL LIFT
TO VFR BY LATE MORNING. MVFR CIGS WILL RETURN TO KDFW LATE TONIGHT
AROUND 26/09Z AND SHOULD END AROUND 26/16Z. 75
&&
.PREV DISCUSSION... /ISSUED 347 AM CDT SAT MAY 25 2013/
RADAR/SATELLITE LOOP INDICATES THAT THE WEAK MID LEVEL LOW IS
LIKELY LOCATED NEAR ABILENE AND 00Z 500MB ANALYSIS CONFIRMS IT IS
WARM-CORE IN NATURE. AS IS OFTEN THE CASE WITH WARM-CORE
LOWS...CONVECTION IS FIRING BEFORE SUNRISE ACROSS THE HILL
COUNTRY WITHIN A WEAK LOW LEVEL JET AXIS WHERE THETA-E ADVECTION
AND OROGRAPHIC LIFT ARE OCCURRING. SHORT-TERM MODELS SUCH AS THE
HRRR AND RUC SUGGEST THAT SCATTERED CONVECTION WILL CONTINUE TO
EXPAND NORTHWARD FROM CENTRAL TEXAS INTO THE WESTERN ZONES DURING
THE MORNING HOURS. THE GFS APPEARS TO BE SUFFERING FROM GRID SCALE
CONVECTIVE FEEDBACK WHICH IS RESULTING IN VERY HIGH QPF AND
CONTAMINATED MASS FIELDS...THUS THE GFS WILL NOT BE USED IN THE
SHORT-TERM. THE NAM SEEMS TO BE MATCHING CURRENT TRENDS AND SHORT-
TERM MODELS WELL AND THEREFORE IT GIVES CONFIDENCE TO RAISE POPS
TODAY. WE EXPECT THE BEST COVERAGE OF CONVECTION IN THE WESTERN
ZONES THIS MORNING. SCATTERED CONVECTION WILL BUILD/EXPAND
EASTWARD INTO THE EASTERN ZONES DURING THE MIDDAY/AFTERNOON HOURS.
THE AIRMASS OVER THE EASTERN ZONES WILL BE A BIT MORE UNSTABLE DUE
TO BETTER INSOLATION AND A COUPLE OF STRONG STORMS WITH GUSTY
WINDS WILL BE POSSIBLE...BUT DUE TO WEAK SHEAR THE SEVERE THREAT
IS LOW. HIGHS TODAY IN THE WESTERN ZONES WILL ONLY BE IN THE UPPER
70S TO LOW 80S DUE TO CLOUDS/RAIN...WITH HIGHS IN THE EASTERN
ZONES REACHING THE MID 80S. SCATTERED CONVECTION WILL CONTINUE
INTO THE EVENING HOURS BEFORE DISSIPATING WITH LOSS OF HEATING.
THE WARM CORE MID LEVEL LOW WILL BE EXITING THE REGION TO THE
NORTHEAST TONIGHT...AND THEREFORE THE RAIN CHANCES WILL COME TO AN
END. EXPECT A DRY SUNDAY WITH TEMPERATURES REBOUNDING INTO THE
MID-UPPER 80S AREA WIDE. AS AN UPPER LEVEL TROUGH DEVELOPS ACROSS
THE INTER-MOUNTAIN WEST...A SURFACE LOW WILL DEEPEN IN THE HIGH
PLAINS MONDAY. THIS WILL BRING BREEZY SOUTH WINDS TO THE REGION
MONDAY WHICH WILL LIKELY PERSIST THROUGH THE WEEK. LOW TEMPS WILL
WARM INTO THE 70S AREA WIDE BY MIDWEEK WITH HIGHS GENERALLY IN THE
MID 80S EAST TO LOW 90S WEST. THE SOUTHWEST FLOW ABOVE THE
SURFACE WILL BRING A THERMAL INVERSION INTO THE AREA. THUS THE
FORECAST LOOKS DRY UNLESS/UNTIL FORCING ARRIVES TO WEAKEN THE CAP.
MODEL GUIDANCE REMAINS IN POOR TO FAIR AGREEMENT REGARDING THE
EVOLUTION/EJECTION OF THE WEST COAST UPPER TROUGH MID-LATE WEEK.
THE ECMWF CONTINUES TO SHOW A VERY NEGATIVELY TILTED TROUGH
SWINGING THROUGH THE REGION LATE WEDNESDAY AND THURSDAY WHICH
WOULD BODE WELL FOR RAIN. BUT IT CONTINUES TO BE THE ONLY MODEL
THAT SHOWS THE TROUGH EJECTION LIKE THIS...AND FRANKLY THE 500MB
PATTERN IT PRESENTS JUST DOES NOT LOOK REALISTIC. IF IT WERE NOT
FOR THE ECMWF BEING THE BETTER OF THE LONG RANGE MODELS...I WOULD
DISCOUNT IT ALTOGETHER AND SHOW A DRY FORECAST ON THURSDAY...BUT
FOR NOW HAVE RETAINED THE SLIGHT CHANCE POPS. THE GFS/UKMET/GEM
FORECASTS SHOW THAT THE UPPER ENERGY NEEDED TO BREAK THE CAP WILL
LIKELY REMAIN WELL NORTHWEST OF THE REGION. FURTHERMORE...THE
DRYLINE ALSO LOOKS LIKE IT WILL REMAIN TOO FAR TO THE WEST...WITH
THE GFS SHOWING IT AS FAR WEST AS THE TX PANHANDLE. STORM MOTIONS
WILL GENERALLY BE NORTHEAST AND THIS MEANS STORMS WOULD NOT EVEN
HAVE A CHANCE TO PROPAGATE INTO THE CWA EITHER. SO IN SUMMARY THE
RAIN CHANCES ON THURSDAY AT THIS POINT ARE HINGING ON THE ECMWF
BEING CORRECT...AND THIS MAY BE A BIT OF A LONG SHOT.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 84 69 87 69 87 / 40 30 10 5 0
WACO, TX 83 68 87 68 89 / 50 30 10 5 0
PARIS, TX 83 67 85 66 85 / 30 30 10 5 0
DENTON, TX 84 67 86 68 87 / 40 30 10 5 0
MCKINNEY, TX 84 67 85 68 87 / 30 30 10 5 0
DALLAS, TX 85 71 87 70 89 / 40 30 10 5 0
TERRELL, TX 84 67 86 68 88 / 40 30 10 5 0
CORSICANA, TX 84 67 88 68 89 / 40 30 10 5 0
TEMPLE, TX 82 67 87 68 88 / 60 20 10 5 0
MINERAL WELLS, TX 81 66 87 67 89 / 40 20 10 5 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1038 AM PDT Sat May 25 2013
.SYNOPSIS...
Memorial Day Weekend is expected to be a little cooler than
average, and a series of weak upper level disturbances will bring
the potential for scattered showers Sunday and Monday. The moist,
showery weather pattern is expected to linger into late next week.
&&
.DISCUSSION...
Update: Satellite imagery from this morning shows two closed
lows...one near the north Washington coast and another over
southern Alberta. Models show these two features moving very
little today. With no strong forcing mechanism to generate
showers...there should be less shower activity today compared to
yesterday. The 13z HRRR model shows most of the showers today
will be along the East Slopes of the Cascades and north of the
Columbia Basin over the northern mountains. This make sense given
these areas are in closest proximity to the two aforementioned
lows...and that showers are more likely to develop over the
mountainous terrain. Forecast has this part of the forecast well
handled with only change to lower mountain pops to 20 percent
through the morning with better chances holding off til afternoon
when instability increases.
Latest SREF and SPC guidance, as well as the 13z HRRR model shows
minimal thunder chances today. The better chances will be north of
the Canadian border...and over the Clearwaters. With cloud cover
this morning extensive over the Idaho Panhandle and northeast
Washington mountains...this will further lower convective
potential. Cloud cover was increased this morning over North
Idaho, and thunder was removed from the northern mountains, but a
slight chance was kept for the Camas Prairie with this area on the
edge of the best convective potential. Also lowered high
temperatures today a few degrees for Sandpoint and Kellogg. JW
&&
.AVIATION...
18Z TAFS: An upper level trough will remain over the Inland
Northwest over the next 24 hours. Today showers will increase
mainly over the mountains but instability is marginal for
thunderstorms with none expected. These showers will die off after
03z with the loss of daytime heating. Another disturbance embedded
within this trough will spreading thickening cloud cover into the
region between after 14z Sunday especially KEAT/KMWH where a few
showers may develop. The bulk of the showers should hold off til
after 18z Sunday. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 44 65 46 65 47 / 20 10 30 40 30 10
Coeur d`Alene 63 42 65 45 64 44 / 20 20 30 40 40 10
Pullman 64 43 63 44 65 46 / 10 10 30 40 20 20
Lewiston 71 48 70 50 71 51 / 10 10 30 40 20 20
Colville 67 41 72 45 69 44 / 40 30 20 20 50 20
Sandpoint 61 39 66 43 63 42 / 30 20 20 40 50 20
Kellogg 59 44 63 46 62 47 / 40 20 30 50 50 20
Moses Lake 72 46 73 49 73 50 / 10 10 30 20 10 20
Wenatchee 68 47 70 49 71 51 / 10 10 30 10 10 20
Omak 68 41 71 45 70 46 / 30 20 30 10 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
345 PM CDT SAT MAY 25 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 341 PM CDT SAT MAY 25 2013
AT 3 PM...A DYING MESOSCALE CONVECTIVE COMPLEX WAS LOCATED OVER
CENTRAL ILLINOIS. THIS SYSTEM PRODUCED UP TO 4 INCHES OF RAIN
ACROSS PARTS OF STORY...MARSHALL...AND JASPER COUNTIES IN CENTRAL
IOWA. MEANWHILE NORTHEAST IOWA AND MOWER COUNTY IN SOUTHEAST
MINNESOTA...RECEIVED UP TO A THIRD OF AN INCH /KARX RADAR WAS
OVERESTIMATING BY UP TO 300 PERCENT IN SOME LOCATIONS/. THE RAIN
AND CLOUDS FROM THIS SYSTEM KEPT TEMPERATURES IN THE LOWER AND MID
50S IN THESE AREAS WHICH IS VERY CLOSE TO THE RECORD COLDEST
MAXIMUM TEMPERATURES FOR THE DATE. THE RECORD COLD MAXIMUM FOR THE
DATE IS 46 IN 1992 FOR AUSTIN MN...48 IN 1943 IN CHARLES CITY
IA...AND 53 IN 1992 IN DECORAH IA. THE DECORAH RECORD IS THE ONLY
ONE THAT COULD POSSIBLY BE BROKEN OR TIED. MEANWHILE AREAS NORTH
OF INTERSTATE 94 SAW A BIT OF SUNSHINE AND THEY WERE ABLE TO WARM
INTO THE MID 60S.
FOR TONIGHT AND SUNDAY...THE MAIN CONCERN IS THE TRACK OF THE
MESOSCALE CONVECTIVE COMPLEX OVER WESTERN NORTH DAKOTA. CORFIDI
VECTORS SUGGEST THAT THIS SYSTEM WILL MOVE EAST ACROSS THE DAKOTAS
THIS EVENING...AND THEN IT WILL MOVE SOUTHEAST ACROSS THE EASTERN
THIRD OF SOUTH DAKOTA...SOUTHERN AND WESTERN MINNESOTA AND NORTHERN
IOWA TONIGHT. OVERALL...THE 25.18Z HRRR HAS THE BEST HANDLE ON THIS
SYSTEM AND IT HAS THIS SYSTEM OVER SOUTHWEST MINNESOTA BY 26.06Z.
WITH THAT SPEED...IT SHOULD MOVE INTO NORTHEAST IOWA AND PARTS OF
SOUTHEAST MINNESOTA BY 26.10Z...AND THEN LINGER ACROSS THESE AREAS
THROUGH MUCH OF SUNDAY MORNING. AHEAD OF THIS SYSTEM...THE
RAP...GFS...NAM/WRF...AND ECMWF SHOW THAT SCATTERED SHOWERS AND
THUNDERSTORMS WILL DEVELOP NORTH OF A WARM FRONT FROM NORTHWEST
IOWA TO SOUTHEAST IOWA. THIS PRECIPITATION IS ASSOCIATED WITH
MODERATE 925 TO 850 MB MOISTURE TRANSPORT AND 310K ISENTROPIC
LIFT.
LIKE TODAY...EXPECT THE LOW CLOUDS AND PRECIPITATION TO KEEP
TEMPERATURES IN THE MID AND UPPER 50S ACROSS SOUTHEAST
MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST WISCONSIN ON SUNDAY.
MEANWHILE SOME SUN NORTH OF INTERSTATE 94 WILL ALLOW TEMPERATURES
TO WARM INTO THE MID 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 341 PM CDT SAT MAY 25 2013
ON SUNDAY NIGHT AND MONDAY...THE WARM FRONT WILL MOVE INTO NORTH
SOUTHWEST IOWA. WEAK TO MODERATE 925 AND 850 MB MOISTURE TRANSPORT
WILL RESULT IN THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS NORTH
OF THE WARM FRONT FROM NORTH CENTRAL IOWA SOUTHEAST INTO SOUTHEAST
IOWA. THE GFS...ECMWF...AND GEM SUGGEST THAT A MESOSCALE
CONVECTIVE COMPLEX WILL DEVELOP ACROSS EASTERN SOUTH DAKOTA LATE
SUNDAY NIGHT...AND THE DYING SYSTEM MOVES EAST THROUGH OUR AREA
MONDAY.
FROM MONDAY NIGHT INTO TUESDAY...THE MODELS ARE CONTINUING TO
STRUGGLE WITH THE LOCATION OF THE WARM FRONT. THE NAM/WRF STALLS
THE WARM FRONT NEAR THE MINNESOTA AND IOWA BORDER. THIS MAKES A
LOT OF SENSE IF A LOT OF CONVECTION DEVELOPS NORTH OF THIS FRONT
AND ITS COLD POOL PREVENTS THIS WARM FRONT MOVING ANY FURTHER
NORTH. MEANWHILE THE GFS AND ECMWF WOULD SYNOPTICALLY FAVOR THAT
THE WARM FRONT WOULD MOVE NORTHWARD THROUGH THE AREA. HOWEVER THE
CAP IN THE WARM SECTOR REMAINS SOUTHWEST OF THE FORECAST
AREA...THUS THERE WOULD BE THE POTENTIAL FOR A SERIES OF MESOSCALE
CONVECTIVE SYSTEMS TO MOVE THROUGH THE AREA. SO IN EITHER
SCENARIO...IT LOOKS LIKE THE FORECAST AREA WILL REMAIN WET. WITH
PRECIPITABLE WATER VALUES AROUND 1.5 INCHES AND WARM CLOUD LAYER
DEPTHS UP TO 4KM...THERE WILL BE THE POTENTIAL FOR HEAVY RAIN FROM
ANY SHOWERS AND THUNDERSTORMS THAT DEVELOP. IN ADDITION...WILL
HAVE TO WATCH FOR THE POTENTIAL OF SEVERE WEATHER...BUT THIS IS
HIGHLY DEPENDENT UPON THE LOCATION OF THE WARM FRONT.
FROM TUESDAY NIGHT INTO SATURDAY...IT CONTINUES TO LOOK LIKE A
SERIES OF SHORT WAVE TROUGHS WILL MOVE THROUGH THE REGION. HOWEVER
THE TIMING OF THESE WAVES IS UNCERTAIN...THUS KEPT PRECIPITATION
CHANCES IN THE 40 TO 60 PERCENT RANGE THROUGH THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1208 PM CDT SAT MAY 25 2013
AREA OF MVFR CEILINGS OVER SOUTHERN INTO WESTERN MINNESOTA HAS
SLIPPED INTO KRST. THE 25.15Z RAP INDICATES THESE SHOULD REMAIN
THROUGH ABOUT THE MIDDLE OF THE AFTERNOON BEFORE THEY RISE TO A
LOW VFR LEVEL FROM THE HEATING OF THE DAY. THE CONCERN FOR THE
OVERNIGHT HOURS IS WHETHER THE NEXT CONVECTIVE COMPLEX WILL IMPACT
THE TAF SITES. THE 25.12Z NAM ALONG WITH THE 25.06Z HI-RES ARW
BOTH SUGGEST THE WARM FRONT WILL REMAIN SOUTH OF THE AREA. THE
NEXT COMPLEX IS EXPECTED TO DEVELOP OVER SOUTH DAKOTA AND THEN
RIDE SOUTHEAST ALONG THE FRONT MOVING ACROSS IOWA INTO ILLINOIS
STAYING SOUTH OF BOTH AIRPORTS. AT THIS POINT...WILL NOT EVEN
INCLUDE A VCSH BUT WILL LOWER THE CEILINGS EXPECTING THE NORTHERN
EDGE OF THE LOWER CLOUDS FROM THE CONVECTIVE COMPLEX TO IMPACT
BOTH AIRPORTS. THE NAM BUFKIT SOUNDINGS SHOWS KRST GOING DOWN TO
MVFR WITH KLSE STAYING VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1209 PM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 230 AM CDT SAT MAY 25 2013
LOW/MID LEVEL FRONTOGENETIC FORCING...COUPLED WITH SOME LOW LEVEL
MOISTURE TRANSPORT AND A BIT OF UPPER LEVEL ENERGY...WERE HELPING
CONTINUE AN AREA OF EAST/SOUTHEAST MOVING SHOWERS. TRENDS IN THE
LATEST HRRR/NAM12 IS TO DIMINISH THIS ACTIVITY THROUGH THE PRE DAWN
HOURS...WHILE FIRING CONVECTION OVER THE SOUTHERN PLAINS/WESTERN IA.
SATELLITE IMAGERY AND RADAR RETURNS ALREADY SHOW THIS
HAPPENING...WHERE THE NOSE OF THE LOW LEVEL JET/MOISTURE TRANSPORT
WAS LOCATED. THIS COMPLEX SHOULD MOVE EAST THROUGH THE REST OF THE
MORNING INTO THE AFTERNOON...RIDING ALONG AND NORTH OF A WARM FRONT.
THIS REGION SHOULD SERVE AS THE FOCUS FOR MORE SHOWER/STORM
DEVELOPMENT TONIGHT...WITH THE LOW LEVEL JET REASSERTING ITSELF AND
SOME UPPER LEVEL ENERGY MOVING OUT OF A WEST COAST TROUGH. EASTWARD
MOVEMENT WOULD AGAIN BE FAVORED...KEEPING THE BULK OF THE PCPN SOUTH
OF THE FORECAST AREA.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 230 AM CDT SAT MAY 25 2013
HIGH CONFIDENCE ITS GOING TO RAIN ACROSS PARTS OF THE REGION THROUGH
THE UPCOMING WORK WEEK. TIMING AND PLACEMENT IS MORE SHAKY.
THE FORECAST KEYS ON A FEW AREAS...A SFC WARM FRONT...LOW LEVEL
JET/MOISTURE TRANSPORT...AND VARIOUS MCVS. WHERE THESE ELEMENTS ALL
COME TOGETHER WILL BE WHERE THE GREATER THREAT FOR RAIN WILL LIE.
CLARITY FOR THE MESOSCALE VORTICIES/SPAWNING GROUNDS AND MOVEMENT
IS THE MAIN STICKING POINT FOR INCREASING CONFIDENCE.
THE UPPER LEVEL PATTERN IS SLOW TO PROGRESS EAST AS THERE IS LITTLE
IMPETUS VIA 250/300MB JET INTERACTION - RELATIVELY QUIET A LOFT.
SO...THE 500 MB RIDGE WILL REMAIN ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY/GREAT LAKES INTO AT LEAST THE MIDDLE PART OF THE NEW WORK
WEEK...WITH A BROAD TROUGH OVER THE WEST COAST. BITS OF ENERGY WILL
SPIN OUT OF THE TROUGH...AND THEN ENHANCE VIA CONVECTION SPAWNED BY
IT AND THE LOW LEVEL JET/MOISTURE TRANSPORT. WITH THE RIDGE OVERHEAD
THE NEXT FEW DAYS...AND THE SFC WARM FRONT HOLDING TO THE
SOUTH...THESE UPPER AIR INFLECTIONS ARE PROGGED TO RIDE ALONG AND
NORTH OF THE WARM FRONT...KEEPING THE BEST RAIN CHANCES JUST SOUTH
-BUT NOT COMPLETELY OUT- OF THE FORECAST AREA.
THE WARM FRONT WILL START TO LIFT NORTH ON TUE...A FAIRLY CONSISTENT
SIGNAL IN THE NAM/GFS/ECMWF. HOW FAR NORTH IS NOT THOUGH...WITH THE
GFS APPEARING THE MORE AGGRESSIVE IN HOW FAR NORTH AND HOW FAST.
RAIN CHANCES LOOK TO BECOME MORE WIDESPREAD FOR THE FORECAST AREA
MON-TUE AS A RESULT.
DEPENDING ON HOW QUICKLY AND HOW FAR NORTH THE WARM FRONT MAKES
IT...THE AREA COULD GET INTO THE WARM SECTOR...WHICH WOULD HELP CAP
OFF THE ATMOSPHERE TO CONVECTION - OUTSIDE OF A KICKER MOVING IN.
MODEL DIFFERENCES START TO BECOME BIGGER AS WE MOVE TOWARD NEXT
WEEKEND...WITH THE EC SUGGESTING A CLOSED LOW WILL DEVELOP IN THE
WEST COAST TROUGH...SLOWLY PUSHING EAST ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY NEXT WEEKEND. THIS COULD LAY UP A SFC TROUGH ACROSS THE
REGION FOR SEVERAL DAYS. THE GFS IS MORE PROGRESSIVE...MOVING THE
UPPER LEVEL ENERGY NORTHEAST...BUT STILL HAS A COUPLE SFC BOUNDARIES
THAT COULD ACT AS SHOWER/STORM PRODUCERS. WILL LIKELY STAY WITH THE
CONSENSUS SOLUTION FOR THE DETAILS IN THIS PART OF THE FORECAST.
AS FOR STORM CHANCES...INSTABILITY IS LIMITED THE NEXT COUPLE
DAYS...AND SO SHOULD BE THE THUNDERSTORMS. THE CHANCE FOR BOOMERS
WILL INCREASE WITH THE ENCROACHMENT OF THE WARM FRONT...AND
SUBSEQUENT INCREASE IN CAPES. DON/T SEE A SIGNIFICANT THREAT FOR
ORGANIZED SEVERE WEATHER THROUGH NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1208 PM CDT SAT MAY 25 2013
AREA OF MVFR CEILINGS OVER SOUTHERN INTO WESTERN MINNESOTA HAS
SLIPPED INTO KRST. THE 25.15Z RAP INDICATES THESE SHOULD REMAIN
THROUGH ABOUT THE MIDDLE OF THE AFTERNOON BEFORE THEY RISE TO A
LOW VFR LEVEL FROM THE HEATING OF THE DAY. THE CONCERN FOR THE
OVERNIGHT HOURS IS WHETHER THE NEXT CONVECTIVE COMPLEX WILL IMPACT
THE TAF SITES. THE 25.12Z NAM ALONG WITH THE 25.06Z HI-RES ARW
BOTH SUGGEST THE WARM FRONT WILL REMAIN SOUTH OF THE AREA. THE
NEXT COMPLEX IS EXPECTED TO DEVELOP OVER SOUTH DAKOTA AND THEN
RIDE SOUTHEAST ALONG THE FRONT MOVING ACROSS IOWA INTO ILLINOIS
STAYING SOUTH OF BOTH AIRPORTS. AT THIS POINT...WILL NOT EVEN
INCLUDE A VCSH BUT WILL LOWER THE CEILINGS EXPECTING THE NORTHERN
EDGE OF THE LOWER CLOUDS FROM THE CONVECTIVE COMPLEX TO IMPACT
BOTH AIRPORTS. THE NAM BUFKIT SOUNDINGS SHOWS KRST GOING DOWN TO
MVFR WITH KLSE STAYING VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04