Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/17/12
AREA FORECAST DISCUSSION
NWS EUREKA CA
340 AM PDT TUE MAY 15 2012
.SYNOPSIS...LOW CLOUDS AND FOG WILL PERSIST ALONG THE PACIFIC
COAST THROUGH WEDNESDAY MORNING. ISOLATED THUNDERSTORMS WILL BE
POSSIBLE WEDNESDAY AND THURSDAY AFTERNOONS OVER THE MOUNTAINS OF
EXTREME EASTERN TRINITY COUNTY.
&&
.DISCUSSION...UPPER LOW WHICH MOVED ACROSS THE S PORTION OF THE
AREA ON MON CONTINUES TO FILL AS IT MOVES SLOWLY E NEAR LAKE
TAHOE. BEHIND THE LOW...A WEAK UPPER RIDGE WILL BUILD OVER THE
LOCAL AREA TODAY. ALTHO THERE WILL BE SOME LINGERING MOISTURE OVER
THE TRINITY MOUNTAINS ALONG WITH MODEST INSTABILITY...FEEL THAT
RIDGE...MINIMAL DYNAMICS...AND CONVECTIVE INHIBITION SHOULD LIMIT
SHOWER ACTIVITY. AS A RESULT...HAVE REMOVED MENTIONABLE POPS FROM
THE FORECAST FOR TODAY.
LOW CLOUDS AND FOG WILL PERSIST ALONG THE PAC COAST TODAY...
EXPANDING INLAND LATER THIS EVENING AND OVERNIGHT. FOG IS EXPECTED
TO DECREASE IN COVERAGE ON WEDNESDAY...BUT WILL LIKELY HOLD FIRM
ALONG THE IMMEDIATE COASTAL AREAS OF N HUMBOLDT INTO EARLY THU AS
WELL AS COASTAL MENDOCINO COUNTY.
ISOLATED CONVECTION MAY RETURN TO THE TRINITY MOUNTAINS ON WED
AFTERNOON...BUT NEXT BEST SHOT OF PRECIP WILL LIKELY BE ASSOCIATED
WITH A DIGGING UPPER TROF THAT WILL SWING INTO THE AREA ON
THU. MOISTURE WILL AGAIN BE SOMEWHAT LIMITED WITH THIS SYSTEM.
HOWEVER...MODELS ARE INDICATING ENUF MOISTURE AND INSTABILITY TO
PRODUCE BETTER CHANCES OF PRECIP E OF THE COUNTY WARNING AREA.
HAVE INCLUDED LOW END CHANCE POPS OVER THE TRINITY HORN.
A COLD FRONT WILL APPROACH THE N PORTION OF THE AREA SUN NIGHT AND
EARLY MON...AND HAVE GONE ABOVE CLIMO POPS DURING THIS PERIOD
MAINLY OVER DEL NORTE COUNTY. /SEC
&&
.AVIATION...CURRENT 11-3.9U SAT AND SURFACE OBS SHOW A BROAD AREA OF
STRATUS ALONG THE COAST AND OFFSHORE. THIS STRATUS MAINLY APPEARS TO
BE LIFR WITH SOME IFR. THERE IS A HOLE IN THIS STRATUS FROM NORTH OF
HUMBOLDT BAY TO NORTH OF THE OR BORDER ALTHOUGH THIS HAS BEGUN TO
FILL IN. SATELLITE ALSO SHOWS A DECENT FINGER OF STRATUS UP THE EEL
RIVER VALLEY UP TO NEARLY WEOTT. THE NAM HAS A DECENT HANDLE ON THIS
AREA OF STRATUS AND SHOWS IT STAYING ALONG THE COAST THROUGH
TONIGHT. THE LOCAL WRF AND 3K HRRR MODELS SHOW THE SAME IDEA
ALTHOUGH THEY SHOW THE STRATUS PUSHING BACK TO NEARLY THE COAST IN
THE AFTERNOON. THE EXACT IMPACT ON THE COASTAL TAF SITES IS
DIFFICULT TO DETERMINE BUT EXPECT A FEW HOURS IN THE AFTERNOON OF
SCATTERED CLOUDS. TONIGHT AS THE NORTHERLIES PICK BACK UP MODELS
SHOW AREAS IMMEDIATELY SOUTH OF CAPE MENDOCINO CLEARING IN THE
AFTERNOON AND REMAINING CLEARING TONIGHT. INLAND AREAS LOOK TO
REMAIN MAINLY CLEAR. MKK
&&
.MARINE...LIGHT TO MODERATE WINDS ARE EXPECTED TO CONTINUE ACROSS
THE WATERS THROUGH TONIGHT IN RESPONSE TO WEAK HIGH PRESSURE.
WEDNESDAY HIGH PRESSURE LOOKS TO BUILD INTO THE NORTHEAST PACIFIC
AND IN CONJUNCTION WITH A THERMAL TROUGH ALONG THE COAST WILL CAUSE
NORTHERLY WINDS TO INCREASE. WINDS LOOK AT PEAK AROUND 20 TO 30 KT.
MODELS ARE IN GOOD AGREEMENT ON THESE NORTHERLIES THROUGH SATURDAY
AND CONFIDENCE IS FAIRLY HIGH. SUNDAY THE GFS BRINGS ANOTHER SYSTEM
THROUGH WHICH WOULD SHIFT THE WINDS TO THE SOUTH. THE ECMWF IS
SLOWER WITH THIS SYSTEM AND DOESNT BRING SOUTHERLIES TO OUR WATERS
UNTIL MONDAY. PREFERENCE WOULD BE TO LEAN TOWARD THE SLOWER ECMWF
BUT LEFT THE GOING FORECAST WHICH IS A COMPROMISE BETWEEN THE TWO
MODELS BRINGING SOME SOUTHERLIES IN SUNDAY NIGHT. SOUTHERLIES LOOK
TO PEAK AROUND 10 TO 20 KT.
WAVES ARE EXPECTED TO BE MAINLY LOCALLY GENERATED THROUGH THE PERIOD
AS THE GLOBAL MODELS ARENT DEVELOPING ANY SIGNIFICANT DISTANT
SYSTEMS TO GENERATE WAVES. WIND WAVES LOOK TO PEAK AROUND 11 FEET ON
THURSDAY IN RESPONSE TO THE NORTHERLIES. MKK
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...NONE.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AT:
HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
940 PM EDT WED MAY 16 2012
.UPDATE (TONIGHT - THURSDAY)...
01Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUES TO SHOW OUR REGION ON
THE EASTERN SIDE OF A DEEP LONGWAVE TROUGH EXTENDING SOUTHWARD OVER
THE WESTERN/CENTRAL GULF OF MEXICO. DEEP COLUMN MOISTURE HAS BEEN
STREAMING NORTHWARD AHEAD OF THIS FEATURE OVER THE FL PENINSULA
THROUGH THE DAY. THIS MOISTURE COMBINED WITH A BROAD SWATH OF DEEP
LAYER SYNOPTIC/QG-FORCING HAS RESULTED IN A FAIRLY WET EVENING
ACROSS THE FORECAST AREA. NUMEROUS SHOWERS AND SOME THUNDERSTORMS
HAVE BEEN STREAMING INLAND FROM THE EASTERN GULF DURING THE PAST
SEVERAL HOURS WITH THE HEAVIEST AND MOST CONCENTRATED RAINFALL
OCCURRING OVER THE TAMPA BAY REGION. THE SHOWERS HAVE BEEN OF A MORE
SCATTERED VARIETY FURTHER NORTH UP THE NATURE COAST...AND ALSO DOWN
TOWARD THE FT. MYERS VICINITY...HOWEVER STILL ENOUGH IN MOST
LOCATIONS FOR MEASURABLE PRECIPITATION.
SHOWERS/AREAS OF RAINFALL WITH EMBEDDED THUNDER LOOK TO REMAIN IN
THE FORECAST INTO THURSDAY MORNING. WV IMAGERY DOES SHOW SOME HIGH
LEVEL DRYING ATTEMPTING TO MOVE OVER OUR NORTHERN ZONES...BUT DO NOT
THINK THAT THIS DRYING WILL BE SUFFICIENT TO SIGNIFICANTLY DISRUPT
CONVECTIVE DEVELOPMENT. GFS/ECMWF BOTH SHOW ANOTHER IMPULSE ROUNDING
THE BASE OF THE MAIN LONGWAVE TROUGH INTO THE EASTERN GULF THROUGH
THURSDAY MORNING. LARGE SCALE FORCING FOR ASCENT AHEAD OF THIS
FEATURE WILL AGAIN INCREASE LATER TONIGHT INTO OUR REGION...AND
COMBINE WITH RESIDUAL MOISTURE TO KEEP AT LEAST SCATTERED CONVECTION
DEVELOPING OVER THE COASTAL WATERS AND MOVING ASHORE. THEREFORE WILL
KEEP CHANCE POPS IN THE FORECAST. HOWEVER...WILL NEED TO MONITOR
TRENDS...ESPECIALLY DURING THE LATER OVERNIGHT HOURS AS THIS ENERGY
CROSSES THE GULF TO DETERMINE IF RAIN CHANCES WILL NEED TO BE
INCREASED NEAR THE COAST THURSDAY MORNING.
BY LATE IN THE DAY...AS THE AXIS OF THIS IMPULSE APPROACHES...DEEPER
DRY AIR APPROACHING THE COAST...AND BETTER SYNOPTIC FORCING HEADING
EAST SHOULD RESULT IN THE BEST THUNDERSTORM CHANCES OVER THE
INTERIOR ZONES...AND DO NOT SEE MUCH REASON FOR SIGNIFICANT CHANGES
TO THE AFTERNOON GRIDS AT THIS TIME.
&&
.AVIATION...
SCT SHOWERS WITH LCL MVFR CIGS/VSBYS ENDING AROUND MIDNIGHT.
OTHERWISE VFR CIGS AOA 120 THROUGH THE NIGHT. SCT TO NUMEROUS
SHOWERS AND THUNDERSTORMS WILL REDEVELOP THURSDAY WITH LCL MVFR CIGS
AND VSBYS...AND ISOLD IFR CIGS/VSBYS WITH STRONGER THUNDERSTORMS.
&&
.MARINE...
TRANQUIL BOATING CONDITIONS WITH LIGHT WINDS AND LOW SEAS WILL
CONTINUE OVER THE GULF WATERS TONIGHT THROUGH FRIDAY. WIND AND
SEAS WILL INCREASE SOME OVER THE UPCOMING WEEKEND AS THE PRESSURE
GRADIENT TIGHTENS IN RESPONSE TO STRONGER HIGH PRESSURE BUILDING
DOWN THE EASTERN SEABOARD AND LOWER PRESSURE OVER THE CARIBBEAN
WITH EXERCISE CAUTION CONDITIONS A POSSIBILITY LATE IN THE WEEKEND
AND INTO EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 71 86 70 89 / 80 40 20 20
FMY 69 85 69 89 / 70 40 20 30
GIF 69 87 70 89 / 80 60 20 30
SRQ 69 83 69 88 / 80 40 20 20
BKV 64 87 63 89 / 60 50 20 20
SPG 72 84 72 87 / 80 40 20 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...14/MROCZKA
AVIATION...13/OGLESBY
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1101 AM EDT Tue May 15 2012
.UPDATE...
Previous forecast seems generally on track and very few changes
were made. Most of the focus was on the evolution of convection
through this afternoon, the associated distribution of PoPs, and
severe weather potential. PoPs were split out into 3-hourly grids
to get a bit more detail on timing of the best rain chances. So
far, the evolution of cumulus fields and light showers appear to
be close to a sea-breeze `regime 5` from our local climatology
(stronger W-SW flow in the 1000-700mb layer). This should be
augmented slightly by a NW-SE low-level moisture gradient with
higher 0-1km mixing ratios situated over the SE half of our area.
Additionally, a weakly defined and stalled front is lingering over
our forecast area which should place the best focus for storms in
the eastern half. PoP grids were a combination of convection-
allowing model (CAM) guidance, ongoing trends, and sea-breeze
`regime 5` climatology. This places likely PoPs along and SE of a
Tallahassee to Tifton line.
The latest SPC Day 1 Convective Outlook places the eastern half of
our area in a region of 5% probabilities for severe wind and hail
(within 25 miles of a point). This seems reasonable as there will
be an abundance of instability. Additionally, wind shear will be
slightly stronger today as compared to yesterday - when storms
failed to show much organization. 14z objective RAP analysis shows
effective bulk shear has now climbed to around 30 knots over much
of our area, near the lower bound for supercell parameter space.
The greatest threat would seem to be for isolated occurences of
damaging winds, particularly in the area of likely PoPs (SE of a
TMA-TLH line) - or SC GA and FL Big Bend. Storm scale ensembles
of high-res model guidance show max gusts in that area around 20
m/s (close to 40 knots) with lower values to the north and west.
Forecast soundings also reveal favorable downburst parameters in
that area with an abundance of dry air in the mid-levels: max
delta thetae around 25C and higher WMSI values. As such, a mention
of damaging winds and heavy rain was added to the forecast in the
aforementioned areas.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 85 65 87 63 88 / 60 30 30 20 30
Panama City 81 67 84 66 84 / 30 10 20 20 20
Dothan 84 64 86 63 88 / 30 30 20 10 20
Albany 86 64 86 63 90 / 20 30 20 10 30
Valdosta 86 64 87 63 89 / 70 20 30 20 40
Cross City 85 65 86 63 88 / 40 20 40 20 40
Apalachicola 82 67 82 65 83 / 30 10 30 20 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
Lamers
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
241 PM EDT TUE MAY 15 2012
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY ACROSS THE REGION WILL PROVIDE A FOCUS FOR
SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND THIS EVENING.
THE FRONT WILL SLOWLY PUSH EASTWARD TONIGHT BUT AGAIN PROVIDE
INCREASED CHANCES OF RAIN ACROSS THE EASTERN MIDLANDS ON WEDNESDAY
BEFORE SHIFTING TO THE COAST. SURFACE HIGH PRESSURE WILL BUILD
INTO THE REGION THURSDAY AND PROVIDE DRY WEATHER THROUGH THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...A WEAK FRONTAL BOUNDARY AND LEFT OVER OUTFLOW
BOUNDARIES WILL PROVIDE A FOCUS FOR SHOWER AND THUNDERSTORM
DEVELOPMENT. SPC HAS AREA IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS
THIS AFTERNOON INTO THE EVENING HOURS. THE LATEST RAP SOUNDING FOR
LATE THIS AFTERNOON CONFIRMS THAT THE ATMOSPHERE SHOULD BE UNSTABLE
ENOUGH TO PRODUCE STRONG TO POTENTIALLY SEVERE STORMS. RAP LIS -5
...CAPES OVER 2000 J/KG...TOTALS OVER 50. NAM SOUNDING GIVES
CONVECTIVE TEMPERATURES 82-84 DEGREE THIS AFTERNOON. TEMPERATURES
SHOULD RISE INTO THE LOWER TO MIDDLE 80S DURING THE AFTERNOON.
THIS IS EXPECTED TO ENHANCE SHOWERS AND THUNDERSTORMS...ESPECIALLY
LATE THIS AFTERNOON. WILL START WITH A 20-30 PERCENT CHANCE THIS
AFTERNOON. LOCAL WRF SHOWS INCREASING TREND...ESPECIALLY LATER
THIS AFTERNOON. JUST ISSUED SEVERE THUNDERSTORM WATCH IN EFFECT.
TONIGHT...BEST CHANCES OF SHOWERS AND THUNDERSTORMS WITH CHANCES
INCREASING TO 40-50 PERCENT. AGREE WITH LOCAL 4 KM WRF MODEL GIVING
HIGHEST CHANCES IN THE EVENING. AS TEMPERATURES DROP BY MIDNIGHT...
DECIDED TO GO JUST 20 PERCENT CHANCE REST OF NIGHT AFTER MIDNIGHT.
THERE MAY BE SOME PATCHY FOG AFTER MIDNIGHT AS WELL BUT LEFT OUT
FOR TIME BEING AS SHOWERS MAY LINGER WELL AFTER MIDNIGHT WITH SOME
CLOUDINESS NOT ALLOWING WIDESPREAD FOG LIKE THIS MORNING. WENT ABOVE
GUIDANCE LOWS 1-2 DEGREES AS PREVIOUS RUNS HAVE BEEN A BIT COOL.
SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 9 PM.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
LOW PRESSURE WILL BE TRACKING FROM NEW ENGLAND INTO THE FAR EASTERN
CANADIAN PROVINCES AS A WEAK FRONTAL BOUNDARY SLOWLY CROSSES THE
FORECAST AREA. ON WEDNESDAY THE FRONT WILL BE OVER THE UPSTATE WITH
ANOTHER UNSTABLE DAY FOR CONVECTIVE ACTIVITY. WITH AROUND 2000 J/KG
CAPE AND LI/S AROUND -5 EXPECT ANOTHER AFTERNOON AND EVENING WITH
SCATTERED SHOWERS AND THUNDERSTORMS. MODELS INDICATE THE BEST
INSTABILITY OVER THE EASTERN MIDLANDS AND...WITH THE POSITION OF THE
FRONT AND HIGHER MOISTURE IN THE EASTERN MIDLANDS...AGREE HIGHEST
POPS TO START IN THAT AREA. WILL EXPAND POPS TO THE REMAINDER OF THE
AREA AS PLENTIFUL INSTABILITY COMBINING WITH OUTFLOWS WILL LIKELY
SPUR ADDITIONAL ACTIVITY. SPC CONTINUES TO KEEP THE REGION IN
GENERAL THUNDER WHICH CURRENTLY SEEMS APPROPRIATE. MAIN THREAT OF
SEVERE ON WEDNESDAY AFTERNOON WILL BE HAIL WITH A LOWER CHANCE FOR
WIND GUSTS. CONVECTIVE ACTIVITY WILL DIMINISH WITH THE LOSS OF
HEATING WEDNESDAY EVENING...HOWEVER WITH OUTFLOW BOUNDARIES REMAINING
OVER THE FORECAST AREA BELIEVE CONVECTION WILL LINGER INTO THE LATE
EVENING/EARLY OVERNIGHT HOURS. AFTERNOON HIGH TEMPERATURES
WEDNESDAY WILL GENERALLY BE IN THE MIDDLE 80S. WITH SOME LINGERING
CLOUDS AND PATCHY FOG EXPECT OVERNIGHT LOWS WEDNESDAY NIGHT IN THE
LOWER 60S.
ON THURSDAY THE FRONT WILL BE OVER THE EASTERN MIDLANDS DURING THE
AFTERNOON AND TRACKING OFFSHORE DURING THE EVENING. INSTABILITY WILL
BE LESS THAN WEDNESDAY...HOWEVER THERE WILL STILL BE ENOUGH TO
INITIATE CONVECTION. BEST INSTABILITY WILL BE CLOSER TO THE FRONT SO
WILL AGAIN INCREASE POPS CLOSEST TO THE FRONT THEN EXPAND A BIT
WESTWARD AS OUTFLOWS TRIGGER SOME ADDITIONAL CONVECTION. SEVERE
THREAT WILL AGAIN BE FROM HAIL WITH LOWER POTENTIAL FOR DAMAGING
WINDS. HIGH TEMPERATURES THURSDAY AFTERNOON WILL GENERALLY BE IN THE
LOWER 80S. CONVECTION WILL DISSIPATE WITH LOSS OF HEATING AND THE
FRONT EDGING OFFSHORE. EXPECT SOME CONVECTION INTO THE EVENING HOURS
AND WITH THE FRONT MOVING OFFSHORE EXPECT CONVECTION TO END BEFORE
THE OVERNIGHT HOURS. LOW TEMPERATURES THURSDAY NIGHT WILL BE A FEW
DEGREES COOLER BEHIND THE FRONT WITH LOWS IN THE UPPER 50S TO LOWER
60S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MODELS REMAIN IN GOOD AGREEMENT THROUGH THE LONG TERM WITH SOME
TYPICAL TIMING AND INTENSITY DIFFERENCES FOR SUNDAY AND MONDAY.
UPPER LEVEL TROUGH WILL EXIT THE REGION EARLY FRIDAY AS THE UPPER
LEVEL RIDGE BUILDS BACK IN. THIS WILL LEAVE A STATIONARY FRONT
ALONG THE COAST TO JUST SOUTH OF THE AREA. MODELS DIFFER ON THE
LOCATION OF THE FRONT...HOWEVER WITH HIGH PRESSURE DOMINATING THE
SURFACE EXPECT MUCH OF THE CONVECTIVE POTENTIAL TO BE SUPPRESSED
THROUGH THE WEEKEND. AS THE HIGH MOVES OFFSHORE MONDAY THE CHANCE
OF THUNDERSTORMS WILL RETURN. MODELS CONTINUE TO HAVE SIGNIFICANT
RUN TO RUN CHANGES ASSOCIATED WITH A LOW WHICH DEVELOPS ALONG THE
COAST. AS A RESULT HAVE REMAINED PESSIMISTIC CONCERNING THIS
FEATURE. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
UPPER TROUGH STILL TO THE WEST BRINGING MOISTURE TO AREA.
WEAK FRONTAL BOUNDARY ACROSS THE REGION AND LEFT OVER OUTFLOW
BOUNDARIES FROM CONVECTIVE ACTIVITY SHOULD PROVIDE A FOCUS FOR
SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING. MAINLY VFR
CONDITIONS BUT BRIEF IFR-MVFR CONDITIONS ARE POSSIBLE IN CONVECTIVE
ACTIVITY. DECIDED NOT TO INCLUDE IN TAFS SITES DUE TO UNCERTAINTY
AS TO TIMING AND COVERAGE. ACTIVITY IS EXPECTED TO TAPER OFF 03Z-04Z
TIME FRAME BUT MAY LINGER NORTH AND EAST OF TAF SITES. AFTER
MIDNIGHT WITH PLENTY OF MOISTURE AND LEFT OVER CLOUDS...NO AS MUCH
FOG EXPECTED BUT STRATUS WILL PROBABLY DEVELOP AGAIN. EXPECT IFR
CEILINGS TO DEVELOP BEFORE DAYBREAK WEDNESDAY. THE UPPER TROUGH
SHOULD HAVE SHIFTED EASTWARD BY WEDNESDAY BUT THERE WILL STILL BE
ENOUGH MOISTURE AND INSTABILITY FOR SOME AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS. WILL GO VFR BUT LOWER CONDITIONS MAY
OCCUR IN CONVECTIVE ACTIVITY.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT RESTRICTIONS ARE
EXPECTED WEDNESDAY NIGHT THROUGH SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1228 PM EDT TUE MAY 15 2012
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY ACROSS THE REGION WILL PROVIDE A FOCUS FOR
SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND THIS EVENING.
THE FRONT WILL SLOWLY PUSH EASTWARD TONIGHT BUT AGAIN PROVIDE
INCREASED CHANCES OF RAIN ACROSS THE EASTERN MIDLANDS ON WEDNESDAY
BEFORE SHIFTING TO THE COAST. SURFACE HIGH PRESSURE WILL BUILD
INTO THE REGION THURSDAY AND PROVIDE DRY WEATHER THROUGH THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WEAK FRONTAL BOUNDARY AND LEFT OVER OUTFLOW BOUNDARIES WILL
PROVIDE A FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT. SPC HAS
REGION IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS THIS AFTERNOON
AND THIS EVENING. THE LATEST RAP SOUNDING FOR LATE THIS AFTERNOON
CONFIRMS THAT THE ATMOSPHERE SHOULD BE UNSTABLE ENOUGH TO PRODUCE
STRONG TO POTENTIALLY SEVERE STORMS. RAP LIS -5...CAPES OVER 2000
J/KG...TOTALS OVER 50. NAM SOUNDING GIVES CONVECTIVE TEMPERATURES
82-84 DEGREE THIS AFTERNOON. TEMPERATURES NOW RISING ABOVE 80...
SO CONVECTIVE ACTIVITY SHOULD BE ON THE INCREASE OVER THE NEXT
2-3 HOURS. WILL START WITH A SLIGHT CHANCE THIS AFTERNOON...THEN
INCREASE TO 40-50 PERCENT THIS EVENING. LOCAL WRF SHOWS SAME TREND
...LESS COVERAGE IN THE AFTERNOON WITH MOST OF THE COVERAGE BEING
IN THE EVENING HOURS. UPDATED HIGH TEMPERATURES THIS AFTERNOON
WITH MOSTLY LOWER 80S BUT DID INCLUDE SOME MIDDLE 80S IN THE SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
EXPECT LINGERING CONVECTION THIS EVENING ACROSS THE FORECAST AREA
SUPPORTED BY UPPER IMPULSES MOVING THROUGH THE SOUTHWESTERLY FLOW
ALOFT. WILL MAINTAIN HIGH CHANCE POPS EARLY WITH DIMINISHING
CHANCES THROUGH THE OVERNIGHT HOURS AS THE ATMOSPHERE BECOMES MORE
STABLE. EXPECT PLENTY OF CONVECTIVE DEBRIS CLOUDS AND THIS SHOULD
LIMIT THE AMOUNT OF RADIATIONAL COOLING OVERNIGHT. MIN
TEMPERATURES SHOULD REMAIN ABOVE NORMAL IN THE LOWER TO MID 60S.
THE SURFACE BOUNDARY SHIFTS VERY SLOWLY EASTWARD ACROSS THE
FORECAST AREA ON WEDNESDAY AND WILL AGAIN PROVIDE A FOCUS FOR
CONVECTIVE DEVELOPMENT. A WEST TO EAST GRADIENT IN DEEPER MOISTURE
WILL EXIST ACROSS THE REGION ON WEDNESDAY WITH THE BEST MOISTURE
BEING FOCUS CLOSER TO THE COASTAL PLAIN AND EASTERN MIDLANDS. THE
ATMOSPHERE WILL DESTABILIZE WITH DAYTIME HEATING AIDED BY COOLING
500 MB TEMPERATURES (-13C). WILL CONTINUE WITH THE CHANCE FOR
SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS...WITH
THE HIGHEST POPS ACROSS THE EASTERN MIDLANDS WHERE BETTER MOISTURE
IS FORECAST AND IN THE VICINITY OF THE SLOW MOVING SURFACE
BOUNDARY. ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE BUT THE
COVERAGE IS NOT EXPECTED TO BE AS GREAT. TEMPERATURES ON WEDNESDAY
WILL GENERALLY BE IN THE LOWER TO MID 80S.
THE UPPER TROUGH AXIS FINALLY SHIFTS EAST ACROSS THE FORECAST AREA
WEDNESDAY NIGHT AND THURSDAY AND DRIER AIR WILL BUILD IN FROM THE
NORTHWEST AS SURFACE HIGH PRESSURE BUILDS IN BEHIND THE DEPARTED
SURFACE FRONT. DESPITE THE COOLER AND DRIER AIR BUILDING INTO THE
REGION...PLENTY OF SUNSHINE IS EXPECTED THURSDAY WHICH WILL OFFSET
ANY WEAK COLD ADVECTION AND TEMPERATURES SHOULD REMAIN SEASONABLE
IN THE LOWER 80S WITH LITTLE CHANCE OF RAIN.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MEDIUM RANGE MODELS ARE IN REASONABLE AGREEMENT INDICATING
TROUGHING ALONG THE WEST COAST DURING THE EXTENDED PERIOD WHICH
WILL RESULT IN DOWNSTREAM RIDGING AND RISING UPPER HEIGHTS OVER
THE FORECAST AREA. DRY WEATHER IS EXPECTED THROUGH THIS PERIOD AS
HIGH PRESSURE AT THE SURFACE AND ALOFT PROVIDE A RELATIVELY STABLE
AND DRY ATMOSPHERE. TEMPERATURES DURING THE PERIOD WILL BE NEAR
NORMAL WITH HIGHS IN THE 80S AND LOWS IN THE 50S TO LOWER 60S.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
MORNING SUN HAS HELPED TO BREAK UP THE FOG AND STRATUS. CONDITIONS
WILL BECOME VFR BY LATE MORNING. CONVERGENCE ASSOCIATED WITH THE
SURFACE TROUGH AND ANOTHER MID-LEVEL SHORTWAVE TROUGH PLUS
HEATING SUPPORTS THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON.
DID NOT INCLUDE THUNDERSTORMS IN THE TERMINAL FORECAST BECAUSE OF
TIMING UNCERTAINTY. STRONG HEATING WITH COLD AIR ALOFT ASSOCIATED
WITH THE UPPER TROUGH WILL RESULT IN MODERATE TO STRONG
INSTABILITY. ANY THUNDERSTORMS MAY CONTAIN STRONG WIND AND HAIL.
EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
ASSOCIATED WITH THE SLOW MOVING FRONT MAY OCCUR THROUGH WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...07
NEAR TERM...07
SHORT TERM...
LONG TERM...
AVIATION...07
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
949 AM EDT TUE MAY 15 2012
.SYNOPSIS...
A NEARLY STATIONARY FRONTAL BOUNDARY WILL PROVIDE A FOCUS FOR
SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON. THE FRONT WILL
SLOWLY PUSH EASTWARD TONIGHT BUT AGAIN PROVIDE INCREASED CHANCES
OF RAIN ACROSS THE EASTERN MIDLANDS ON WEDNESDAY BEFORE SHIFTING
TO THE COAST. SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION
THURSDAY AND PROVIDE DRY WEATHER THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CONVERGENCE ASSOCIATED WITH THE SURFACE TROUGH AND ANOTHER MID-
LEVEL SHORTWAVE TROUGH PLUS HEATING SUPPORTS SHOWERS AND
THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. USED THE HIGHER
GUIDANCE POPS BECAUSE OF THIS SUPPORT. LOW-LEVEL MOISTURE
ASSOCIATED WITH CONVERGENCE INTO THE SURFACE TROUGH WILL REMAIN
HIGH TODAY. UPPER-LEVEL MOISTURE WILL BE A LITTLE LESS COMPARED TO
THE PAST FEW DAYS. EXPECT THE DIMINISHED MOISTURE WILL LEAD TO
MORE HEATING AND INSTABILITY. LATEST RAP SOUNDING SHOWS ATMOSPHERE
BECOMING UNSTABLE LATE THIS AFTERNOON WITH LIS -5...CAPES OVER
2000 J/KG...AND TOTALS OVER 50. OTHER MODELS ALSO SHOW MODERATE
TO STRONG INSTABILITY THIS AFTERNOON. SPC HAS ARE OUTLOOKED IN A
SLIGHT RISK...SO THERE COULD BE POSSIBLY DAMAGING WIND AND HAIL
WITH A FEW OF THE THUNDERSTORMS. USED THE GUIDANCE CONSENSUS FOR
THE TEMPERATURE FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
EXPECT LINGERING CONVECTION THIS EVENING ACROSS THE FORECAST AREA
SUPPORTED BY UPPER IMPULSES MOVING THROUGH THE SOUTHWESTERLY FLOW
ALOFT. WILL MAINTAIN HIGH CHANCE POPS EARLY WITH DIMINISHING
CHANCES THROUGH THE OVERNIGHT HOURS AS THE ATMOSPHERE BECOMES MORE
STABLE. EXPECT PLENTY OF CONVECTIVE DEBRIS CLOUDS AND THIS SHOULD
LIMIT THE AMOUNT OF RADIATIONAL COOLING OVERNIGHT. MIN
TEMPERATURES SHOULD REMAIN ABOVE NORMAL IN THE LOWER TO MID 60S.
THE SURFACE BOUNDARY SHIFTS VERY SLOWLY EASTWARD ACROSS THE
FORECAST AREA ON WEDNESDAY AND WILL AGAIN PROVIDE A FOCUS FOR
CONVECTIVE DEVELOPMENT. A WEST TO EAST GRADIENT IN DEEPER MOISTURE
WILL EXIST ACROSS THE REGION ON WEDNESDAY WITH THE BEST MOISTURE
BEING FOCUS CLOSER TO THE COASTAL PLAIN AND EASTERN MIDLANDS. THE
ATMOSPHERE WILL DESTABILIZE WITH DAYTIME HEATING AIDED BY COOLING
500 MB TEMPERATURES (-13C). WILL CONTINUE WITH THE CHANCE FOR
SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS...WITH
THE HIGHEST POPS ACROSS THE EASTERN MIDLANDS WHERE BETTER MOISTURE
IS FORECAST AND IN THE VICINITY OF THE SLOW MOVING SURFACE
BOUNDARY. ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE BUT THE
COVERAGE IS NOT EXPECTED TO BE AS GREAT. TEMPERATURES ON WEDNESDAY
WILL GENERALLY BE IN THE LOWER TO MID 80S.
THE UPPER TROUGH AXIS FINALLY SHIFTS EAST ACROSS THE FORECAST AREA
WEDNESDAY NIGHT AND THURSDAY AND DRIER AIR WILL BUILD IN FROM THE
NORTHWEST AS SURFACE HIGH PRESSURE BUILDS IN BEHIND THE DEPARTED
SURFACE FRONT. DESPITE THE COOLER AND DRIER AIR BUILDING INTO THE
REGION...PLENTY OF SUNSHINE IS EXPECTED THURSDAY WHICH WILL OFFSET
ANY WEAK COLD ADVECTION AND TEMPERATURES SHOULD REMAIN SEASONABLE
IN THE LOWER 80S WITH LITTLE CHANCE OF RAIN.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MEDIUM RANGE MODELS ARE IN REASONABLE AGREEMENT INDICATING
TROUGHING ALONG THE WEST COAST DURING THE EXTENDED PERIOD WHICH
WILL RESULT IN DOWNSTREAM RIDGING AND RISING UPPER HEIGHTS OVER
THE FORECAST AREA. DRY WEATHER IS EXPECTED THROUGH THIS PERIOD AS
HIGH PRESSURE AT THE SURFACE AND ALOFT PROVIDE A RELATIVELY STABLE
AND DRY ATMOSPHERE. TEMPERATURES DURING THE PERIOD WILL BE NEAR
NORMAL WITH HIGHS IN THE 80S AND LOWS IN THE 50S TO LOWER 60S.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
MORNING SUN HAS HELPED TO BREAK UP THE FOG AND STRATUS. CONDITIONS
WILL BECOME VFR BY LATE MORNING. CONVERGENCE ASSOCIATED WITH THE
SURFACE TROUGH AND ANOTHER MID-LEVEL SHORTWAVE TROUGH PLUS
HEATING SUPPORTS THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON.
DID NOT INCLUDE THUNDERSTORMS IN THE TERMINAL FORECAST BECAUSE OF
TIMING UNCERTAINTY. STRONG HEATING WITH COLD AIR ALOFT ASSOCIATED
WITH THE UPPER TROUGH WILL RESULT IN MODERATE TO STRONG
INSTABILITY. ANY THUNDERSTORMS MAY CONTAIN STRONG WIND AND HAIL.
EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
ASSOCIATED WITH THE SLOW MOVING FRONT MAY OCCUR THROUGH WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...07
SHORT TERM...
LONG TERM...
AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
402 PM CDT TUE MAY 15 2012
.DISCUSSION...
251 PM CDT
FORECAST FOCUS IN NEAR TERM REMAINS COLD FRONTAL PASSAGE THIS
EVENING AND THE POTENTIAL FOR ISOLATED/SCATTERED CONVECTION. AFTER A
MUCH COOLER DAY WEDNESDAY...A WARMING TREND BACK TO SUMMER-LIKE
TEMPERATURES AND EVENTUALLY AND INCREASING POTENTIAL FOR
THUNDERSTORMS IS EXPECTED THROUGH THE WEEKEND.
AT 19Z...SFC ANALYSIS DEPICTS COLD FRONT STRETCHING FROM NEAR GREEN
BAY WISCONSIN...TO AMES IN CENTRAL IOWA. WARM SECTOR AHEAD OF FRONT
IS CHARACTERIZED BY TEMPS IN MID-UPPER 80S FROM NORTHERN IL BACK
INTO EASTERN IA...THOUGH VERY DRY LOW LEVELS AS INDICATED BY SFC DEW
PTS GENERALLY IN THE UPPER 30S TO MID 40S. THIS NOT SURPRISING GIVEN
EXTREMELY DRY LOW-MID LEVELS SEEN IN 12Z RAOBS AT UPSTREAM AT
MPX/OAX...THOUGH THERE IS A NARROW AXIS OF SLIGHTLY HIGHER DWPTS
FROM WESTERN IL INTO NORTHEAST IL. 18Z RAP APPEARS TO HAVE A DECENT
HANDLE ON THE LOW LEVEL MOISTURE FIELD...AND REMAINS CONSISTENT IN
DEVELOPING CONVECTIVE PRECIP AHEAD OF FRONT ACROSS CNTRL/EASTERN WI
AND DEVELOPING IT SOUTHEAST INTO NORTHERN/NORTHEAST IL EARLY THIS
EVENING. DESPITE VIGOROUS MID-LEVEL SHORT WAVE DIGGING SOUTHEAST
ACROSS THE NORTHERN LAKES...STEEP LOW/MID LEVEL LAPSE RATES AND THE
APPROACH OF A RELATIVELY STRONG COLD FRONTAL BOUNDARY...DEARTH OF
LOW LEVEL MOISTURE SUGGESTS IT WILL LIKELY BE DIFFICULT TO DEVELOP
SIGNIFICANT THUNDERSTORM COVERAGE...WITH HIGH LCL/LFC AND FAIRLY
SKINNY CAPE PROFILES OF 200-300 J/KG ALOFT PER RAP SOUNDINGS. THUS
WHILE ISOLATED-SCATTERED STORMS CANT BE RULED OUT COMPLETELY WITH
FROPA EARLY THIS EVENING...CONTINUE TO SUSPECT COVERAGE WILL BE
RELATIVELY LOW AND CONDITIONAL SEVERE THREAT MINIMAL. AS NOTED
PREVIOUSLY...ANY ACTIVITY WHICH DOES DEVELOP SHOULD HAVE A FAIRLY
STRONG DIURNAL COMPONENT AND SHOULD FADE QUICKLY WITH COOLING OF
BOUNDARY LAYER BEYOND SUNSET. WILL CONTINUE TO MAINTAIN ONLY LOW
CHANCE POPS.
HIGH PRESSURE WILL THEN BUILD ACROSS THE GREAT LAKES REGION
WEDNESDAY IN THE WAKE OF THE MID-LEVEL WAVE AND COLD FRONT. MUCH
COOLER TEMPS THAN TODAY CAN BE EXPECTED...RANGING FROM AROUND 60
NEAR THE LAKE MICHIGAN SHORE TO THE LOW 70S IN THE FAR WEST/SOUTH
REACHES OF THE CWA. FLAT UPPER LEVEL RIDGE THEN SPREADS ACROSS THE
MIDWEST THURSDAY...WITH LOW LEVEL WARM ADVECTION FOCUSING ACROSS THE
UPPER MISSISSIPPI VALLEY AND ACROSS THE NORTHERN LAKES FRIDAY. AXIS
OF LOW LEVEL 40-50 KT JET KEEPS THUNDERSTORM FOCUS NORTH/NORTHWEST
OF THE CWA THROUGH THIS TIME. UPPER RIDGE STRENGTHENS OVER THE
MIDWEST INTO THE WEEKEND AS BROAD TROUGH PUSHES EAST ACROSS THE
WESTERN HALF OF THE CONUS. SOUTHEAST/SOUTH FLOW THROUGH THE PERIOD
WILL LEAD TO TEMPS GRADUALLY WARMING FROM THE 70S THURSDAY INTO THE
LOW-MID80S FRI AND MID 80S SAT. LOW LEVEL MOISTURE WILL ALSO
GRADUALLY INCREASE FROM THE WEST/SOUTHWEST OVER THE WEEKEND AS
WESTERN TROUGH AND COLD FRONT SLOWLY APPROACH. GUIDANCE HAS SLOWED
FRONTAL ARRIVAL SOMEWHAT...HOLDING OFF GREATER PRECIP/THUNDERSTORM
THREAT UNTIL SUNDAY NIGHT AND MONDAY. UPPER TROUGH THEN MOVES SLOWLY
ACROSS THE AREA EARLY NEXT WEEK WITH COOLER WEATHER AS LOW LEVEL
FLOW BECOMES NORTHERLY BEHIND THE FRONT.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* GUSTY WSWLY-WLY WINDS TODAY...TURNING NELY LATE TONIGHT.
* CHANCE OF TSRA EARLY THIS EVENING.
KREIN
//DISCUSSION...UPDATED 18Z...
FOR THE REMAINDER OF THE AFTERNOON...THE MAIN CONCERN WILL BE
WINDS. WITH A FRONTAL TROUGH APPROACHING FROM THE NORTH AND HIGH
PRESSURE OVER THE OHIO VALLEY...BRISK WSWLY-WLY WINDS WILL
CONTINUE. UNDER GENERALLY CLEAR SKIES...HIGHER WINDS HAVE BEEN
ABLE TO MIX DOWN TO THE SFC WITH GUSTS TO AROUND 25KT LIKELY TO
CONTINUE THOUGH THE AFTERNOON.
BY EARLY EVENING...THE FOCUS OF CONCERN WILL SHIFT TO THUNDERSTORM
POSSIBILITIES. A COLD FRONT CONTINUES TO DROP SWD THROUGH
WISCONSIN AND IS EXPECTED TO CROSS THE BORDER INTO IL BY ARND 00Z.
WHILE SFC MOISTURE IS RATHER LOW OVER NRN IL/IN...FRONTAL FORCING
AND ADEQUATE WARMTH WILL BE IN PLACE TO GENERATE SHOWERS AND
WIDELY SCATTERED THUNDERSTORMS. THE GREATEST CHANCE FOR THUNDER
WILL BE BEFORE SUNSET...WITH CHANCES DECREASING AFTER SUNSET AND
THROUGH THE EVENING. GIVEN THAT THUNDER COVERAGE IS EXPECTED TO BE
SPARSE...WILL ONLY CARRY A VCTS MENTION IN THE TAFS.
FOLLOWING THE FROPA...WINDS WILL RAPIDLY SHIFT THROUGH NWLY TO NLY
TO NELY OVERNIGHT. WITH HIGH PRESSURE BUILDING IN BEHIND THE
FRONT...WINDS ARE EXPECTED TO REMAIN NELY THROUGH TOMORROW.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM TO HIGH CONFIDENCE REGARDING WIND DIRECTION/SPEEDS/GUSTS
THROUGH THE PERIOD.
* LOW TO MEDIUM CONFIDENCE REGARDING TSRA LATE AFTERNOON THROUGH
EARLY THIS EVENING.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT THROUGH SATURDAY...VFR.
* SUNDAY...CHANCE OF TSRA. GUSTY SOUTHWEST WINDS.
* MONDAY...CHANCE OF TSRA.
KJB
&&
.MARINE...
353 PM CDT
A COLD FRONT TRAILING BACK SOUTHWESTWARD FROM LOW PRESSURE OVER
FAR EASTERN ONTARIO BETWEEN JAMES BAY AND GEORGIAN BAY...ACROSS
THE FAR EASTERN UPPER PENINSULA OF MI...CENTRAL WI AND SE IA WILL
CONTINUE TO PUSH SE ACROSS THE UPPER GREAT LAKES AND MID MS VALLEY
THIS EVENING AS THE LOW CONTINUES TO MOVE E TO CENTRAL QUEBEC
DURING THE NIGHT. HIGH PRESSURE CENTERED OVER SOUTHERN MANITOBA
AND EXTENDING S ACROSS THE NORTHERN PLAINS WILL BUILD ACROSS THE
UPPER MIDWEST AND MID MO VALLEY OVERNIGHT BEHIND THE COLD FRONT.
COLD AIR ADVECTION AND A SIGNIFICANT 3 HR PRESSURE RISE CENTER OF
5-6 MB WAS MOVING SE ACROSS CENTRAL LAKE SUPERIOR AND THE U.P. OF
MI GENERATING SOME NW GUSTS TO AROUND 30 KT BEHIND THE COLD FRONT.
THIS PRESSURE RISE CENTER IS EXPECTED TO SWING ACROSS NORTHERN
LAKE MI THIS EVE CAUSING SOME GUSTY NW AND N WINDS MAINLY ON THE N
PORTION OF THE LAKE.
HIGH PRESSURE CENTERED OVER SOUTHERN MANITOBA AND EXTENDING S
ACROSS THE NORTHERN PLAINS WILL BUILD ACROSS THE UPPER MIDWEST AND
MID MO VALLEY OVERNIGHT BEHIND THE COLD FRONT WITH THE PRESSURE
GRADIENT OVER LAKE MI GRADUALLY WEAKENING AND THE RESULTANT WINDS
SLACKING. THIS HIGH THEN MOVES E OVER THE UPPER GREAT LAKES DURING
WED BRINGING LIGHTER WINDS TO THE LAKE. AS THE HIGH SHIFTS FURTHER
E TO THE LOWER GREAT LAKES DURING THU SE WINDS WILL START TO
SLOWLY INCREASE THU NIGHT AND FRI AS LOW PRESSURE MOVES E OVER THE
CENTRAL PLAINS.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
252 PM CDT TUE MAY 15 2012
.DISCUSSION...
251 PM CDT
FORECAST FOCUS IN NEAR TERM REMAINS COLD FRONTAL PASSAGE THIS
EVENING AND THE POTENTIAL FOR ISOLATED/SCATTERED CONVECTION. AFTER A
MUCH COOLER DAY WEDNESDAY...A WARMING TREND BACK TO SUMMER-LIKE
TEMPERATURES AND EVENTUALLY AND INCREASING POTENTIAL FOR
THUNDERSTORMS IS EXPECTED THROUGH THE WEEKEND.
AT 19Z...SFC ANALYSIS DEPICTS COLD FRONT STRETCHING FROM NEAR GREEN
BAY WISCONSIN...TO AMES IN CENTRAL IOWA. WARM SECTOR AHEAD OF FRONT
IS CHARACTERIZED BY TEMPS IN MID-UPPER 80S FROM NORTHERN IL BACK
INTO EASTERN IA...THOUGH VERY DRY LOW LEVELS AS INDICATED BY SFC DEW
PTS GENERALLY IN THE UPPER 30S TO MID 40S. THIS NOT SURPRISING GIVEN
EXTREMELY DRY LOW-MID LEVELS SEEN IN 12Z RAOBS AT UPSTREAM AT
MPX/OAX...THOUGH THERE IS A NARROW AXIS OF SLIGHTLY HIGHER DWPTS
FROM WESTERN IL INTO NORTHEAST IL. 18Z RAP APPEARS TO HAVE A DECENT
HANDLE ON THE LOW LEVEL MOISTURE FIELD...AND REMAINS CONSISTENT IN
DEVELOPING CONVECTIVE PRECIP AHEAD OF FRONT ACROSS CNTRL/EASTERN WI
AND DEVELOPING IT SOUTHEAST INTO NORTHERN/NORTHEAST IL EARLY THIS
EVENING. DESPITE VIGOROUS MID-LEVEL SHORT WAVE DIGGING SOUTHEAST
ACROSS THE NORTHERN LAKES...STEEP LOW/MID LEVEL LAPSE RATES AND THE
APPROACH OF A RELATIVELY STRONG COLD FRONTAL BOUNDARY...DEARTH OF
LOW LEVEL MOISTURE SUGGESTS IT WILL LIKELY BE DIFFICULT TO DEVELOP
SIGNIFICANT THUNDERSTORM COVERAGE...WITH HIGH LCL/LFC AND FAIRLY
SKINNY CAPE PROFILES OF 200-300 J/KG ALOFT PER RAP SOUNDINGS. THUS
WHILE ISOLATED-SCATTERED STORMS CANT BE RULED OUT COMPLETELY WITH
FROPA EARLY THIS EVENING...CONTINUE TO SUSPECT COVERAGE WILL BE
RELATIVELY LOW AND CONDITIONAL SEVERE THREAT MINIMAL. AS NOTED
PREVIOUSLY...ANY ACTIVITY WHICH DOES DEVELOP SHOULD HAVE A FAIRLY
STRONG DIURNAL COMPONENT AND SHOULD FADE QUICKLY WITH COOLING OF
BOUNDARY LAYER BEYOND SUNSET. WILL CONTINUE TO MAINTAIN ONLY LOW
CHANCE POPS.
HIGH PRESSURE WILL THEN BUILD ACROSS THE GREAT LAKES REGION
WEDNESDAY IN THE WAKE OF THE MID-LEVEL WAVE AND COLD FRONT. MUCH
COOLER TEMPS THAN TODAY CAN BE EXPECTED...RANGING FROM AROUND 60
NEAR THE LAKE MICHIGAN SHORE TO THE LOW 70S IN THE FAR WEST/SOUTH
REACHES OF THE CWA. FLAT UPPER LEVEL RIDGE THEN SPREADS ACROSS THE
MIDWEST THURSDAY...WITH LOW LEVEL WARM ADVECTION FOCUSING ACROSS THE
UPPER MISSISSIPPI VALLEY AND ACROSS THE NORTHERN LAKES FRIDAY. AXIS
OF LOW LEVEL 40-50 KT JET KEEPS THUNDERSTORM FOCUS NORTH/NORTHWEST
OF THE CWA THROUGH THIS TIME. UPPER RIDGE STRENGTHENS OVER THE
MIDWEST INTO THE WEEKEND AS BROAD TROUGH PUSHES EAST ACROSS THE
WESTERN HALF OF THE CONUS. SOUTHEAST/SOUTH FLOW THROUGH THE PERIOD
WILL LEAD TO TEMPS GRADUALLY WARMING FROM THE 70S THURSDAY INTO THE
LOW-MID80S FRI AND MID 80S SAT. LOW LEVEL MOISTURE WILL ALSO
GRADUALLY INCREASE FROM THE WEST/SOUTHWEST OVER THE WEEKEND AS
WESTERN TROUGH AND COLD FRONT SLOWLY APPROACH. GUIDANCE HAS SLOWED
FRONTAL ARRIVAL SOMEWHAT...HOLDING OFF GREATER PRECIP/THUNDERSTORM
THREAT UNTIL SUNDAY NIGHT AND MONDAY. UPPER TROUGH THEN MOVES SLOWLY
ACROSS THE AREA EARLY NEXT WEEK WITH COOLER WEATHER AS LOW LEVEL
FLOW BECOMES NORTHERLY BEHIND THE FRONT.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* GUSTY WSWLY-WLY WINDS TODAY...TURNING NELY LATE TONIGHT.
* CHANCE OF TSRA EARLY THIS EVENING.
KREIN
//DISCUSSION...UPDATED 18Z...
FOR THE REMAINDER OF THE AFTERNOON...THE MAIN CONCERN WILL BE
WINDS. WITH A FRONTAL TROUGH APPROACHING FROM THE NORTH AND HIGH
PRESSURE OVER THE OHIO VALLEY...BRISK WSWLY-WLY WINDS WILL
CONTINUE. UNDER GENERALLY CLEAR SKIES...HIGHER WINDS HAVE BEEN
ABLE TO MIX DOWN TO THE SFC WITH GUSTS TO AROUND 25KT LIKELY TO
CONTINUE THOUGH THE AFTERNOON.
BY EARLY EVENING...THE FOCUS OF CONCERN WILL SHIFT TO THUNDERSTORM
POSSIBILITIES. A COLD FRONT CONTINUES TO DROP SWD THROUGH
WISCONSIN AND IS EXPECTED TO CROSS THE BORDER INTO IL BY ARND 00Z.
WHILE SFC MOISTURE IS RATHER LOW OVER NRN IL/IN...FRONTAL FORCING
AND ADEQUATE WARMTH WILL BE IN PLACE TO GENERATE SHOWERS AND
WIDELY SCATTERED THUNDERSTORMS. THE GREATEST CHANCE FOR THUNDER
WILL BE BEFORE SUNSET...WITH CHANCES DECREASING AFTER SUNSET AND
THROUGH THE EVENING. GIVEN THAT THUNDER COVERAGE IS EXPECTED TO BE
SPARSE...WILL ONLY CARRY A VCTS MENTION IN THE TAFS.
FOLLOWING THE FROPA...WINDS WILL RAPIDLY SHIFT THROUGH NWLY TO NLY
TO NELY OVERNIGHT. WITH HIGH PRESSURE BUILDING IN BEHIND THE
FRONT...WINDS ARE EXPECTED TO REMAIN NELY THROUGH TOMORROW.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM TO HIGH CONFIDENCE REGARDING WIND DIRECTION/SPEEDS/GUSTS
THROUGH THE PERIOD.
* LOW TO MEDIUM CONFIDENCE REGARDING TSRA LATE AFTERNOON THROUGH
EARLY THIS EVENING.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT THROUGH SATURDAY...VFR.
* SUNDAY...CHANCE OF TSRA. GUSTY SOUTHWEST WINDS.
* MONDAY...CHANCE OF TSRA.
KJB
&&
.MARINE...
219 AM CDT
A COLD FRONT WILL PROGRESS DOWN THE LENGTH OF LAKE MICHIGAN THIS
AFTERNOON AND EVENING. A WIND SHIFT OUT OF THE NORTH CAN BE EXPECTED
FOLLOWING THE PASSAGE OF THIS FRONT. THE FRONT SHOULD BEGIN TO MOVE
ACROSS THE NORTHERN HALF OF THE LAKE LATER THIS AFTERNOON AND THEN
PROGRESS ACROSS THE SOUTHERN HALF OF THE LAKE DURING THE EVENING. IT
APPEARS THAT ONCE THE FRONT PASSES THERE COULD BE A SHORT PERIOD OF
NORTHERLY WINDS UP AROUND 30 KT. THE WINDS WILL BECOME LIGHTER LATER
ON WEDNESDAY AS A SURFACE AREA OF HIGH PRESSURE MOVES ACROSS THE
LAKE. ONCE THIS HIGH SHIFTS EAST OF THE LAKE ON THURSDAY...LOW
PRESSURE ACROSS THE PLAINS WILL ALLOW WINDS TO BECOME SOUTHERLY
AGAIN FOR AN EXTENDED PERIOD THROUGH THE UPCOMING WEEKEND.
FOR THE NEAR SHORE WATERS IT APPEARS WINDS WILL BECOME GUSTY OUT OF
THE WEST SOUTHWEST TODAY AHEAD OF THE AFOREMENTIONED FRONT
DROPPING DOWN LAKE MICHIGAN. IT APPEARS THE WINDS COULD GUST INTO
THE 20 TO 25 KT RANGE UP NEAR THE ILLINOIS AND WISCONSIN
BOARDER...WITH SLIGHTLY LIGHTER GUSTS AROUND 20 KT EXPECTED
FARTHER SOUTH. I WILL HOLD OFF ON A SMALL CRAFT ADVISORY AND
MENTION 15 TO 25 KT WINDS FOR MY FAR NORTHERN MARINE NEAR SHORE
ZONE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
430 PM EDT TUE MAY 15 2012
.SHORT TERM.../TONIGHT-WED NGT/
CDFNT MOVG ACROSS WI/IA THIS AFTN WILL MOVE SE ACROSS OUR CWA
TONIGHT. BKN HIGH BASED CU AND ISOLATED LIGHTNING STRIKES ALONG
FRONT OVER WI/IA ATTM. SFC OBS AND 12Z UPR AIR ANALYSIS SUGGESTS
LATEST NCEP MODELS CONT TO BE TOO MOIST IN LOW LEVELS... THUS
CONFIDENCE IN BKN LINE OF SHOWERS/TSTMS DVLPG FROM MI-SE IA BY 00Z
AS DEPICTED BY LATEST 4KM SPC WRF IS LOW. HRRR INDICATING
CONSIDERABLY LOWER CHC OF CONVECTION REACHING OUR AREA AND APPEARS
TO BE HANDLING THE SFC DWPTS AHEAD OF THE FRONT A LITTLE BETTER. IN
EITHER CASE... ANY SHOWERS/TSTMS WHICH DEVELOP ALONG FRONT LATE
THIS AFTN/EARLY EVE SHOULD BE IN A WKNG/DISSIPATING STAGE UPON
REACHING OUR CWA GIVEN DRY AIRMASS IN PLACE AND DIURNAL
STABILIZATION. ALTHOUGH CONFIDENCE LOW IN CONVECTION REACHING OUR
AREA... FELT GOING LOW CHC OF TSTMS TONIGHT WORTH LEAVING IN FCST
ATTM. GIVEN STEEP LAPSE RATES ABOVE DVLPG SHALLOW NOCTURNAL SFC
BASED INVERSION... POTENTIAL FOR SOME GUSTY WINDS IF CONVECTION
DOES REACH OUR CWA.
HIGH PRESSURE BUILDING INTO THE AREA BEHIND THE FRONT WED WILL
RESULT IN CLEARING SKIES. FAIRLY STRONG CAA SHOULD HOLD TEMPS DOWN
ABOUT 10F FROM TODAYS READINGS DESPITE SUNNY SKIES MOST OF THE DAY.
WITH HIGH MOVG OVERHEAD WED NGT LIGHT WINDS AND DRY AIRMASS WILL
RESULT IN GOOD RADIATIONAL COOLING WITH LOWS IN THE L-M40S ACROSS
THE AREA.
&&
.LONG TERM...
PROGRESSIVE PATTN ALOFT CONTS TO HOLD SWAY THIS PD. LEAD SW TROUGH
OVR SRN ON THIS AFTN WILL RAPIDLY DRIVE EWD UP THROUGH THE ST LAW
VALLEY THU AS SFC RIDGING SHIFTS EWD W/ROBUST WAA DVLPG DURING THE
DAY. MEXMOS APPROXIMATION STILL HOLDS AND SEE NO REASON TO CHG
ANYTHING.
AFT THAT...SIG UPR RIDGING DVLPS EWD OF WRN US TROUGHING AND
INTENSIFIES ACRS THE MID ATL COAST THIS WEEKEND. THERMAL RIDGE
INBTWN WILL BE QUITE WARM FOR MID MAY STANDARDS WITH LOW-MID 80S
XPCD FRI-SUN. EJECTING WRN TROUGH SAT PROGGED TO QUICKLY DEAMPLIFY
EWD MON IN RESPONSE TO DOWNSTREAM UPR RIDGING AND RENEWED FOCUS ON A
MORE SIG WAVE TRAIN ENTERING NWPAC/SW CANADA. IN ADDN...CONTD
SUGGESTION OF A TROPICAL DISTURBANCE OVR THE WRN CARIBBEAN WILL
ELIMINATE ANY SIG GOMEX MSTR RTN. GIVEN CONTD POOR MODEL HANDLING OF
BNDRY LYR MSTR AND XPCD WKNG FNTL SYS...WILL SLASH GOING POPS LWR
MON/MON NIGHT. REMAINDER ON TRACK.
&&
.AVIATION...
VFR CONDITIONS WILL CONT THROUGH THE PERIOD. COLD FRONT WILL CROSS
THE AREA OVERNIGHT WITH WIND SHIFT LATE EVENING TO NORTH AND
EVENTUALLY NORTHEAST. MOISTURE LIMITED ALONG FRONT AND CHANCES FOR
CONVECTION SMALL SO CONTD WITH NO INCLUSION OF PRECIPITATION AT TAF
SITES AT THIS TIME... THOUGH IF CONVECTION DOES DEVELOP AND SURVIVES
LONG ENOUGH INTO THE NIGHT TO REACH THE TERMINALS... COULD BE
ACCOMPANIED BY GUSTY WINDS GIVEN STEEP LAPSE RATES IN PLACE ABOVE
DVLPG SHALLOW SFC BASED NOCTURNAL INVERSION.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 4 PM EDT WEDNESDAY
FOR LMZ043-046.
&&
$$
SHORT TERM...JT
LONG TERM...T
AVIATION...JT
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
632 AM CDT TUE MAY 15 2012
.AVIATION...
VFR CONDITIONS EXPECTED NEXT 24 HRS. COLD FRONT TO PASS THROUGH
THE TERMINALS BETWEEN 21Z AND 03Z BRINGING SHIFT IN WINDS FROM
W/SW TO N/NW. THERE IS A SMALL CHANCE OF A SHOWER OR THUNDERSTORM
AHEAD OF FRONT... BUT CONSIDERABLE UNCERTAINTY WITH DEVELOPMENT
AS MODELS VERIFYING TOO MOIST WITH SFC DEWPTS. THUS...FAVORING
A DRY FRONTAL PASSAGE AS DEPICTED BY RECENT RAP AND HRRR MODEL
RUNS GIVEN DEEP MIXING AND GUSTY SOUTHWEST WINDS 10-20+ KTS PRE-
FRONTAL DRYING OUT THE LOW LEVELS.
&&
.PREV DISCUSSION... /ISSUED 353 AM CDT TUE MAY 15 2012/
SYNOPSIS...
RATHER VIGOROUS COMPACT SHORTWAVE DIVING E/SE INTO WRN ONTARIO
PROVINCE AND NRN MN EARLY THIS AM. ATTENDANT WEAK SFC LOW WAS
LOCATED OVER THE ARROWHEAD OF MN WITH COLD FRONT TRAILING SWWD
THROUGH SD. LIMITED MOISTURE WITH FRONT WITH SFC DEWPTS IN THE
30S AND 40S... AND PRECIPITABLE WATER VALUES AROUND 0.5 INCH
OR LESS OVER THE UPPER MIDWEST.
SHORT TERM...TODAY AND TONIGHT...
MAIN FCST CONCERN IS PCPN CHCS AND SEVERE POTENTIAL WITH FRONT
THIS AFTN/EVE.
SHORTWAVE OVER NRN MN AND WESTERN ONTARIO AND ATTENDANT 100 KT
H3 JET WILL SLIDE S/E THROUGH GREAT LAKES TDY... WITH
CWA GENERALLY S/W OF MAIN FORCING IN FORM OF LEFT EXIT REGION
OF JET AND POSITIVE VORTICITY ADVECTION. COLD FRONT IS
EXPECTED TO MOVE INTO NORTHERN CWA BY MID AFTN AND CONTINUE
SLIDING S/E EXITING THE SOUTHERN CWA BY LATE EVE. MODELS INSIST
ON INCREASING SFC DEWPTS INTO THE MID/UPPER 50S AHEAD OF THE
FRONT WITH LAYER PRECIPITABLE WATER VALUES CLIMBING TO AROUND
1 INCH. BELIEVE THIS IS AGGRESSIVE GIVEN RECENT DRY STRETCH
COUPLED WITH GUSTY SW WINDS AND DEEP MIXING... AND VEERING H85
WINDS TO WESTERLY. ADJUSTING SFC DEWPTS INTO THE 40S TO
POSSIBLY LOWER 50S YIELDS MLCAPE GENERALLY ON THE ORDER OF 750-
1100 J/KG OR SO. WEAK SFC CONVERGENCE AND CONVECTIVE TEMPS
(83-86F) BREACHED SHOULD BE SUFFICIENT TO GENERATE AT LEAST
WIDELY SCT CONVECTION BY MID AFTN AHEAD OF THE FRONT SLIDING E/SE
INTO EVE. 0-6 KM BULK SHEAR OF 30-35 KTS AND STEEP MID LEVEL
LAPSE RATES COUPLED WITH DRY AIR WILL SUPPORT HAIL RISK WITH
LOCAL CALCULATIONS FOR KCID AT 21Z BASED ON T/TD OF 85/46F
SUGGESTS HAIL POTENTIAL AROUND 1.25 INCH IN DIAMETER. LARGE DEWPT
DEPRESSIONS SFC TO CLOUD BASE WITH INVERTED V TYPE SOUNDINGS
WOULD ALSO SUPPORT STRONG GUSTY WINDS. SO... BOTTOM LINE ANTICIPATE
ISOLD-SCT BKN LINE OF CONVECTION FIRING AHEAD OF FRONT AND
SLIDING S/E BETWEEN ROUGHLY 20Z-03Z... WITH ISOLD SEVERE THREAT IN
FORM OF OF LARGE HAIL AND DAMAGING WINDS. SEVERE RISK SUBJECT TO
CHANGE DEPENDING ON LOW LEVEL MOISTURE WITH SIGNFICANT IMPACT ON
THERMODYNAMICS. DEEP MIXING AOA 700 MB WITH GUSTY PRE-FRONTAL
COMPRESSIONAL HEATING SHOULD RESULT IN WIDESPREAD HIGHS IN MID 80S
WITH SOME UPPER 80S ESPECIALLY IN CORRIDOR FROM NEAR KDBQ AND KCID
TO KBRL WITHIN LOW LEVEL THERMAL RIDGE. FRONT TO BE SOUTH OF THE
CWA BY 03Z-06Z WITH CLEARING AND NORTH WINDS USHERING IN COOLER AND
DRIER AIR... WITH COOLEST LOWS NORTH (46-49F) AND WARMEST FAR SOUTH
(52-55F). ..05..
LONG TERM...WEDNESDAY THROUGH NEXT MONDAY...
WEDNESDAY...LATEST 00Z MODEL RUNS CONTINUE TO ADVERTISE THE IDEA OF
A BACKDOOR TYPE HIGH PRESSURE SYSTEM BUILDING DOWN THE WESTERN GRT
LKS EFFECTIVELY SHUNTING SFC BOUNDARY DOWN THROUGH THE MID/LOWER MS
RVR VALLEY...AS UPPER RIDGING AMPLIFIES ACRS THE NORTHERN PLAINS. THE
LATEST RUNS NOT AS ROBUST WITH STRENGTH AND DEPTH OF INCOMING POST-
FRONTAL NORTHEASTERN FETCH BUT STILL ENOUGH COOL AIR ADVECTION TO
HOLD DOWN TEMPS WELL IN THE 70S FOR WED HIGHS. SOME UPPER 60S EVEN
POSSIBLE IN NORTHWESTERN IL. WED NIGHT...LATEST INDICATIONS STILL
SUGGEST NOCTURNAL MCS GENERATION PARAMETERS INCLUDING A SOUTHERLY 50+
KT LLJ COME TOGETHER ACRS THE NORTHERN PLAINS AND THEN FEED ANY
RESULTANT CONVECTIVE SYSTEM EASTWARD ACRS THE EASTERN DAKOTAS...MN
AND WI INTO THU MORNING. THUS IT APPEARS LOW CHANCE OF ANY CONVECTION
MAKING IT INTO THE NORTHERN CWA BY THU MORNING AND WILL REMOVE
MENTIONABLE POPS. WED NIGHT RELATIVELY COOL IN THE LOWER 50S TO MID
40S BEFORE RETURN FLOW INCREASES TOWARD THU MORNING.
THURSDAY AND FRIDAY...00Z RUN MEDIUM RANGE SOLUTIONS INCLUDING THE
NEW GFS AND ECMWF GENERALLY AGREE THAT WARM FRONTAL RETREAT PROCESS
WILL COMBINE WITH RIDGE-RIDING VORT MAX/S FOR MCS GENERATION OR
REGENERATION THIS PERIOD MAINLY UP ACRS THE NORTHWESTERN HIGH
PLAINS...EASTWARD ACRS MN...WI AND INTO THE GRT LKS. THE DVN CWA
STILL LOOKS TO BE MAINLY SOUTH OF THESE CONVECTIVELY ACTION ZONES AND
INCREASINGLY IN THE WARM SECTOR WITH FRI HIGHS WELL UP IN THE 80S.
WILL IGNORE THE 00Z GFS SPURIOUS CONVECTIVE DEVELOPMENT RIGHT ACRS
THE DVN CWA FRI AFTERNOON AS CAPPING INVERSION WILL BE ON THE
INCREASE.
SATURDAY THROUGH MONDAY...LONGER RANGE TRENDS CONTINUING TO SUGGEST
EASTERN PACIFIC UPPER JET ENERGY AND INLAND PROPAGATING UPPER WAVES
WILL COMBINE TO PUMMEL OUT A L/W COMPLEX ACRS THE WESTERN ROCKIES BY
THE WEEKEND. IF THIS PROCESS UNFOLDS AS CURRENTLY INDICATED BY THE
FAVORED ECMWF AND UKMET SOLUTIONS...RESULTANT AMPLIFIED LEE SIDE
UPPER RIDGE WOULD MEAN A VERY WARM AND DRY SAT AND SAT NIGHT FOR THE
LOCAL FCST AREA WITH SAT HIGHS IN THE UPPER 80S. LOOKING AT UPPER
JET PROJECTILE PATHS...A LARGE PIECE OF THE WESTERN UPPER TROF WILL
HAVE TO EVENTUALLY PUSH ACRS THE UPPER MIDWEST AND PREFER THE SLOWER
ECMWF SOLUTION OF SHUNTING AN ASSOCIATED SFC FRONT TOWARD THE AREA
SOMETIME LATE SUNDAY NIGHT OR MONDAY MORNING. WITH ANY KIND OF
MOISTURE RETURN OFF THE WESTERN GULF/ALTHOUGH LATEST SOLUTIONS ARE
NOW MARGINAL WITH THIS PROCESS/...THERE WILL BE AN INCREASING
CHANCE OF SHOWERS AND STORMS FROM THE WEST WITH THE HIGHER POP WINDOW
APPEARING TO BE LATE SUNDAY...SUNDAY NIGHT AND LINGERING INTO MONDAY
MORNING IN POST-FRONTAL FORM BY THEN. TIMING AN HANDLING OF THIS
FEATURE AS WELL AS PHASING WITH THE BROAD SCALE FORCING STILL
SOMEWHAT UNCERTAIN AND DIFFICULT TO BETTER TO DEFINE AT THIS POINT.
ANY SLOW DOWN OF THESE PROCESSES WOULD MEAN A ANOTHER UNSEASONABLY
WARM AND MAINLY DRY DAY ON SUNDAY AND A STORMY MONDAY. THIS IS WHAT
THE 00Z ECMWF IS ADVERTISING WHILE THE MORE PROGRESSIVE GFS TARGETS
THE MAIN CONVECTIVE EVENT ON SUNDAY. LATEST AO/NAO PROGS SUGGEST A
DECENT COOL DOWN ACRS THE UPPER MIDWEST/WESTERN GRT LKS EARLY NEXT
WEEK BEHIND THE PASSING UPPER TROF. ..12..
AVIATION... /ISSUED 1158 PM CDT MON MAY 14 2012/
HIGH PRESSURE SOUTHEAST OF THE REGION WILL CONTINUE THE VFR
CONDITIONS WITH CLEAR SKIES AND LIGHT WEST WINDS THROUGH TUESDAY
AFTERNOON. TUESDAY MORNING WINDS WILL INCREASE OUT OF THE
SOUTHWEST AT 10 TO 20KTS WITH GUSTS. THERE IS A CHANCE OF
THUNDERSTORMS AFTER 21Z AS A COLD FRONT SLOWLY DROPS INTO THE
REGION. COVERAGE AND PROBABILITY IS STILL SOMEWHAT LOW...AS THERE
MAY BE MORE DRY AIR WHICH WOULD ACT TO SUPPRESS STORMS. FOR
NOW...HAVE PUT IN SOME VCSH TO KCID...KDBQ AND KMLI AS THESE WILL
BE CLOSEST TO THE FRONT AT THE TIMES WHEN IT IS MOST LIKELY TO
PRODUCE ANYTHING CONVECTIVE. THE REDUCED LOW LEVEL MOISTURE MAY DO
NO MORE THAN REDUCE STORM COVERAGE AND KEEP STORMS THAT DO FORM
RELATIVELY WEAK...SO HAVE GONE WITH JUST THE SHOWERS FOR NOW.
LATER FORECASTS WILL HAVE TO REFINE FURTHER. FOR NOW HAVE JUST VFR
CONDITIONS THOUGH ANY STORMS MAY HAVE MVFR CIGS AND VSBYS. LE
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
841 PM MDT WED MAY 16 2012
.UPDATE...
ISSUED AT 827 PM MDT WED MAY 16 2012
MAIN UPDATE WAS TO REMOVE THREAT OF THUNDERSTORMS FROM EASTERN
COLORADO TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 150 PM MDT WED MAY 16 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW SHORTWAVE RIDGE
OVER WESTERN KS BEGINNING TO BREAK DOWN AS SHORTWAVE TROUGH OVER
GREAT BASIN CONTINUES TO MOVE EAST INTO THE CENTRAL ROCKIES. TIGHT
GRADIENT CURRENTLY IN PLACE ACROSS CWA NO EASTERN EXTENT OF LEE
TROUGH HAS LED TO BREEZY CONDITIONS ACROSS THE AREA...WITH WINDS
GUSTING AROUND 30KT AT SEVERAL LOCATIONS. A WARM FRONT JUST
SOUTHWEST OF GOODLAND LIFTING TO THE NORTHEAST. WEST OF THIS FRONT
RH VALUES HAVE DROPPED TO 15% OR LOWER. WITH SEVERAL LOCATIONS
ALREADY WITHIN RED FLAG CRITERIA...PLAN ON KEEPING RFW IN PLACE
THROUGH EXPIRATION (02Z).
SHORTWAVE TROUGH WILL CONTINUE TO MOVE EAST WITH LARGE SCALE ASCENT
SPREADING INTO EASTERN COLORADO. RADAR RETURNS ALREADY SHOWING
SHOWERS/THUNDERSTORMS ALONG FRONT RANGE...WITH ACTIVITY GENERALLY
MOVING FROM THE SOUTH TO NORTH. LATEST RUC/HRRR SHOW THIS ACTIVITY
REMAINING JUST EAST OF THE CWA. WITH LARGE SCALE ASCENT STILL
EXPECTED TO OVERSPREAD THE CWA...AND THE CLOSE PROXIMITY OF
ACTIVITY...I DECIDED TO LEAVE ISOLATED THUNDERSTORMS IN FORECAST
THIS EVENING.
SHORTWAVE TROUGH AXIS CURRENTLY PROGGED TO MOVE EAST ACROSS WESTERN
KS. GUIDANCE IN GENERAL AGREEMENT ON TIMING...HOWEVER STRENGTH AND
POSITION OF SHORTWAVE ARE STILL ISSUES...WITH KEEPING OUR CWA
DRY...AND OTHER GUIDANCE FAVORING THE SOUTH AND EAST LATE THURSDAY
AFTERNOON. WITH INSTABILITY/LARGE SCALE ASCENT ACROSS THE CWA
THURSDAY...SLIGHT CHANCE POPS FROM PREVIOUS FORECAST SEEMED
REASONABLE. TIGHT SURFACE GRADIENT WILL REMAIN IN PLACE OVER EASTERN
PARTS OF CWA...WITH NAM/GFS BL WINDS APPROACHING ADVISORY CRITERIA
FOR A PERIOD OF TIME THURSDAY AFTERNOON. CONFIDENCE IS NOT THERE
THAT ADVISORY CRITERIA WINDS WILL LAST 3HR...SO NO HAZARD PLANNED.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 248 PM MDT WED MAY 16 2012
THURSDAY EVENING THE SHORT WAVE TROUGH WILL CONTINUE TO MOVE EAST
ACROSS THE AREA. LATEST GUIDANCE DISAGREES WITH THE LOCATION OF THE
SHORT WAVE TROUGH DURING THE EVENING...WITH THE GFS SHIFTING THE
TROUGH FURTHER NORTH WHILE THE NAM HAS KEPT THE TROUGH OVER THE
SOUTHERN PART OF THE AREA. WITH MODELS NOT BEING CONSISTENT WITH
THE PLACEMENT OF THE SHORT WAVE TROUGH...WILL EXPAND THE SLIGHT
CHANCES TO INCLUDE THE ENTIRE AREA EAST OF THE COLORADO LINE. WITH
A DEEP WELL MIXED LAYER IN PLACE OVER THE AREA...STRONG DOWN BURST
WINDS WILL BE POSSIBLE WITH ANY THUNDERSTORM THAT DEVELOPS DURING
THE EARLY EVENING. THE SHORT WAVE TROUGH AND MID LEVEL CAPE WILL
EXIT THE AREA AROUND MIDNIGHT BRINGING ANY CHANCE FOR PRECIPITATION
TO AN END.
FRIDAY A DRY LINE SETS UP OVER THE CENTRAL PART OF THE AREA. DURING THE
MID TO LATE AFTERNOON A SHORT WAVE TROUGH MOVES OVER THE DRY LINE.
POINT SOUNDINGS FOR THE AREA SHOW THE ENVIRONMENT NEARING SATURATION
AROUND THE 500MB LEVEL ON UP...SO AM THINKING THE STORM DEVELOPMENT
WILL BE TIED TO THE LOCATION OF THE 500MB LIFT. HOWEVER CANNOT RULE
OUT ENOUGH CONVERGENCE OCCURRING OVER THE DRY LINE FOR A STORM OR TWO
TO INITIATION...SO HAVE PLACED SLIGHT CHANCES ALONG THE DRY LINE WITH
FOCUS ON THE BETTER AREA OF 500MB LIFT DURING THE LATE
AFTERNOON. WITH THE DEEP WELL MIXED ENVIRONMENT OVER THE
AREA...STRONG DOWN BURST WINDS ARE POSSIBLE WITH ANY STORM THAT
DEVELOPS DURING THE EARLY EVENING. THE SHORT WAVE TROUGH EXITS THE
AREA AROUND MIDNIGHT...BRINGING PRECIPITATION CHANCES TO AN END.
SOUTH WINDS WILL INCREASE DURING THE LATE MORNING AND AFTERNOON AS
STRONGER WINDS ABOVE THE SURFACE MIX DOWN TO THE GROUND. THE
SURFACE PRESSURE GRADIENT WILL ALSO TIGHTEN THROUGH THE AFTERNOON
AHEAD OF THE COLD FRONT THAT WILL MOVE THROUGH DURING THE OVERNIGHT
HOURS. WINDS WILL PEAK DURING THE LATE AFTERNOON...WITH GUSTS UP TO
40 MPH POSSIBLE. THE WINDS WILL EASE SOME DURING THEN EVENING AS
MIXING CEASES...BUT WILL STILL BE GUSTY DUE TO THE TIGHT PRESSURE
GRADIENT IN PLACE AHEAD OF THE COLD FRONT.
DURING THE OVERNIGHT HOURS A COLD FRONT WILL MOVE INTO THE AREA FROM
THE NORTHWEST. LATEST CROSS SECTIONS SHOW THE LIFT TO BE SITUATED
AHEAD OF THE FRONT IN THE DRIER AIR. WILL BE KEEPING THE FRONTAL
PASSAGE FOR THE OVERNIGHT PERIOD DRY AS A RESULT.
THE SATURDAY THROUGH FRIDAY PERIOD WILL START OFF WITH PRECIPITATION
CHANCES ACROSS MOST OF THE AREA SATURDAY...FOLLOWING A SHORT WAVE
TROUGH AND COLD FRONT THAT WILL MOVE THROUGH THE AREA DURING THE
DAY. BULK OF THE MOISTURE WILL BE OVER THE NORTHERN HALF OF THE
AREA...CAUSING PRECIPITATION CHANCES TO QUICKLY DECREASE OVER THE
SOUTHERN PART OF THE AREA THAT WILL BE IN THE DRIER AIR. BEHIND THE
FRONT WINDS WILL BE GUSTY...BUT SHOULD DECLINE THROUGH THE DAY AS
THE FRONT MOVES FURTHER SOUTH.
SATURDAY EVENING PRECIPITATION CHANCES CONTINUE AS THE SHORT WAVE
TROUGH MOVES ACROSS THE EASTERN PART OF THE AREA. MODELS HAVE A
SECOND SHORT WAVE TROUGH FOLLOWING THE FIRST ONE OVER THE WESTERN
PART OF THE AREA. AM NOT TOO CONFIDENT THERE WILL BE MUCH MOISTURE
FOR THE SECOND SHORT WAVE TO WORK WITH...BUT KEPT IN SLIGHT CHANCES
FOR THE REST OF THE AREA TO STAY CONSIST ANT WITH NEIGHBORS.
PRECIPITATION CHANCES RETURN WEDNESDAY TO THE EASTERN PART OF THE
AREA AS ANOTHER SHORT WAVE TROUGH MOVES ACROSS THE AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 449 PM MDT WED MAY 16 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT BOTH
TERMINALS. A LEE TROUGH WILL CONTINUE TO BE LOCATED OVER EASTERN
COLORADO TONIGHT AND SLOWLY MOVE INTO WESTERN KANSAS THURSDAY.
WINDS WILL CONTINUE TO BE GUSTY THROUGH THE OVERNIGHT HOURS WITH
GUSTS OF 18-20 KNOTS POSSIBLE. LOW LEVEL JET WILL STRENGTHEN
OVERNIGHT WITH LLWS POSSIBLE AT BOTH TERMINALS. HOWEVER...WITH
SURFACE WINDS GUSTY OVERNIGHT...FEEL THAT WILL NOT MEET LLWS
CRITERIA SO WILL KEEP OUT OF SIGHT ATTM AND CONTINUE TO WATCH
THROUGH THE EVENING HOURS. WINDS WILL BE GUSTY ON THURSDAY AND
MID LEVEL CLOUDS WILL INCREASE AS A DISTURBANCE MOVES INTO THE
REGION. ISOLATED THUNDERSTORMS ARE POSSIBLE THURSDAY BUT
TIMING/COVERAGE IS UNCERTAIN SO WILL KEEP OUT OF TAFS.
&&
.FIRE WEATHER...
ISSUED AT 248 PM MDT WED MAY 16 2012
FRIDAY AFTERNOON SOUTH WINDS WILL STRENGTHEN...WITH GUSTS UP TO 40
MPH ACROSS THE AREA. RELATIVE HUMIDITIES WILL FALL INTO THE 10 TO
20 PERCENT RANGE DURING THE AFTERNOON FOR LOCATIONS WEST OF A
MCCOOK TO GOVE LINE...LEADING TO HAZARDOUS FIRE WEATHER
CONDITIONS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...007
SHORT TERM...DR
LONG TERM...JTL
AVIATION...BAS
FIRE WEATHER...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
243 PM MDT TUE MAY 15 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 1249 PM MDT TUE MAY 15 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW SHORTWAVE
RIDGE ACROSS CENTRAL ROCKIES...WITH DEEP UPPER LOW UPSTREAM OVER
NORTHERN CALIFORNIA. A COLD FRONT IS CURRENTLY JUST NORTH OF OUR
CWA...WITH TEMPERATURES AHEAD OF THE FRONT OVER OUR CWA IN THE MID
TO UPPER 80S...AND TEMPERATURES BEHIND THE FRONT IN THE MID TO
UPPER 70S.
THE COLD FRONT TO THE NORTH OF THE CWA WILL DROP SOUTH AND EAST
THIS EVENING...WITH INCREASING TD NORTH OF THE FRONT AS WINDS
SHIFT TO THE EAST-SOUTHEAST. IF TD VALUES IN THE LOW-MID 40S WERE
TO ADVECT INTO THE NORTHERN HALF OF OUR CWA...RADIATIONAL FOG
COULDNT BE RULED OUT. GUIDANCE IS CURRENTLY SHOWING BL REMAINING
UNSATURATED THROUGH WED MORNING...SO FOG WAS LEFT OUT OF
FORECAST.
LARGE SCALE SUBSIDENCE AND A VERY DRY/STABLE AIR MASS WILL REMAIN
IN PLACE THROUGH WEDNESDAY AFTERNOON. SHORTWAVE TROUGH BEGINS TO
MOVE EAST INTO THE CENTRAL ROCKIES BY WED AFTERNOON...WHICH
COULD BRING THUNDERSTORM CHANCES TO EASTERN COLORADO COUNTIES BY
LATE WEDNESDAY AFTERNOON. OVERALL TREND IS TO SLOW DOWN THE
ARRIVAL OF LIFT/MOISTURE WITH THIS FEATURE...SO I LIMITED SLIGHT
CHANCE MENTION CLOSER TO 00Z OVER NW PART OF YUMA COUNTY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 239 PM MDT TUE MAY 15 2012
THE NORTHERN PERIPHERY OF AN UPPER LEVEL RIDGE WILL MOVE OVER THE
AREA WEDNESDAY NIGHT. MEANWHILE A SHORT WAVE TROUGH WILL MOVE ALONG
THE PERIPHERY OF THE RIDGE...ENTERING THE NORTHWEST PART OF THE AREA
DURING THE EVENING. SLIGHT CHANCES FOR PRECIPITATION START DURING
THE EARLY EVENING AS POINT SOUNDINGS FROM 550 MB ON UP BEGIN TO
SATURATE OVER THE WESTERN PART OF YUMA COUNTY. WITH 100J/KG OF
700-500MB MOST UNSTABLE CAPE IN THE VICINITY AND CONVECTIVE
TEMPERATURES BEING REACHED DURING THE EARLY EVENING...AN ISOLATED
THUNDERSTORM IS CERTAINLY POSSIBLE AHEAD OF THE SHORT WAVE TROUGH.
WITH MOISTURE INCREASING ABOVE 600MB AND A LOBE OF 500MB VORTICITY
MOVING OVER THE NORTHWEST PART OF THE AREA AROUND MIDNIGHT...HAVE
PRECIPITATION CHANCES PEAKING AT THIS TIME THEN DECLINING TOWARDS
MORNING AS THE 500MB VORTICITY AND SHORT WAVE TROUGH MOVE NORTHEAST
INTO NEBRASKA. WITH A DEEP DRY LAYER IN PLACE...AM NOT TOO
CONFIDENT THAT ANY RAINFALL PRODUCED WILL MAKE IT TO THE
GROUND...BUT CANNOT COMPLETELY RULE OUT MEASURABLE PRECIPITATION
FROM OCCURRING.
THURSDAY ANOTHER SHORT WAVE TROUGH WILL MOVE INTO THE AREA DURING
THE LATE MORNING HOURS...MOVING ACROSS THE AREA THROUGH THE DAY AND
EXITING THE AREA DURING THE LATE EVENING. LATEST NAM HAS SHIFTED THE
TRACK OF THE TROUGH FURTHER SOUTH WHICH IS IN LINE WITH THE GFS. AS
SUCH HAVE SHIFTED THE BULK OF THE PRECIPITATION CHANCES TO AREAS
GENERALLY ALONG AND SOUTH OF HIGHWAY 24 DURING THE AFTERNOON. AS
THE TROUGH MOVES THROUGH...THE AREA OF 500MB VORTICITY BECOMES MORE
DISJOINTED. IN ADDITION THE DEEP DRY LAYER WILL PERSIST THROUGH THE
AFTERNOON AND EVENING...SO DECIDED TO KEEP PRECIPITATION CHANCES IN
THE SLIGHT CATEGORY. PRECIPITATION CHANCES SHIFT TO THE EASTERN
PART OF THE AREA DURING THE MID TO LATE AFTERNOON AS 500MB VORTICITY
SPREADS NORTH WHILE THE SHORT WAVE TROUGH MOVES THROUGH THE EASTERN
HALF OF THE AREA.
LATE THURSDAY MORNING AND THROUGH THE AFTERNOON SOUTH WINDS WILL STRENGTHEN
FOR LOCATIONS GENERALLY EAST OF A RUSSELL SPRINGS TO MCCOOK LINE AHEAD
OF A SURFACE TROUGH OF LOW PRESSURE. 850MB WINDS OF 20 TO 30 KTS
WILL MIX DOWN TO THE SURFACE AHEAD OF THE SURFACE TROUGH PRODUCING
GUSTS UP TO 40 MPH FOR THE ABOVE LOCATIONS. THE WINDS WILL DECLINE
DURING THE LATE AFTERNOON AS THE STRONGER WINDS MOVE EAST OF THE
AREA. SEE FIRE WEATHER SECTION FOR FIRE WEATHER INFORMATION.
FOR THE FRIDAY THROUGH TUESDAY PERIOD AN UPPER LEVEL SHORT WAVE
TROUGH WILL MOVE THROUGH THE AREA SATURDAY WITH ANOTHER ON MONDAY.
THE STRONGEST SHORT WAVE WILL MOVE THROUGH ON SATURDAY ACCOMPANIED
BY A COLD FRONT. AS A RESULT THE BEST CHANCE FOR PRECIPITATION WILL
BE SATURDAY...MAINLY TIED TO THE FRONTAL PASSAGE. A DRY SLOT WILL
MOVE OVER THE SOUTHERN PART OF THE AREA SATURDAY...DIMINISHING
PRECIPITATION CHANCES FOR THAT AREA. A MINOR SHORT WAVE THROUGH
WILL MOVE THROUGH THE AREA MONDAY...SO HAVE SLIGHT CHANCES IN PLACE
ACROSS MOST OF THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1136 AM MDT TUE MAY 15 2012
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD AT BOTH KGLD AND
KMCK. COLD FRONT ALREADY DROPPING SOUTH OVER KMCK WITH WINDS
SHIFTING TO THE NORTHEAST WITH GUSTS 15-17KT THROUGH SUNSET. WINDS
WILL REMAIN VARIABLE AT KGLD THROUGH ABOUT 04Z...WHEN FRONT DROPS
JUST EAST OF TERMINAL AND WINDS SHIFT TO THE SOUTHEAST AROUND
10KT. SURFACE LOW DEVELOPS BY WEDNESDAY AFTERNOON OVER EASTERN
COLORADO...WITH INCREASED GRADIENT LEADING TO GUSTY SOUTH WINDS
DEVELOPING BY 18Z. STRONGEST WINDS SHOULD OCCUR AFTER 18Z...SO I
ONLY SHOWED INCREASING TREND AFTER 15Z IN THE CURRENT TAF
PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 239 PM MDT TUE MAY 15 2012
FIRE WEATHER WATCH FOR WED WAS UPGRADED TO RED FLAG WARNING...WITH
CONFIDENCE HIGH IN RFW CRITERIA BEING MET. WINDS ACROSS THE
WESTERN HALF OF THE AREA SHOULD BE WELL WITHIN CRITERIA WITH GUSTS
AROUND 35 MPH POSSIBLE. THERE WERE SOME QUESTIONS REGARDING TO
RH...WITH SHORTWAVE TROUGH OVER CENTRAL COLORADO POSSIBLY BRINGING
HIGHER TD VALUES INTO WESTERN PARTS OF CWA. EVEN IF MIXING WERE TO
BE LIMITED IN THE WEST AND TD VALUES REMAIN SLIGHTLY HIGHER...RH
VALUES AROUND 15-17% WOULD STILL BE EXPECTED. BASED ON LOWER MODEL
TRENDS AND BETTER MIXING...CURRENT FORECAST SHOWS RH 12-15%. WITH
WINDS GUSTING AROUND 35 MPH...RFW CRITERIA IS LIKELY UNDER EITHER
SCENARIO.
LOW RELATIVE HUMIDITIES OF 15 TO 20 PERCENT AND STRONG SOUTH WINDS
WITH GUSTS UP TO 40 MPH WILL DEVELOP FOR LOCATIONS EAST OF A
RUSSELL SPRINGS TO MCCOOK LINE THURSDAY AFTERNOON. THESE CONDITIONS WILL
CREATE HAZARDOUS FIRE WEATHER CONDITIONS DURING THE AFTERNOON.
LATEST FUEL STATUS FOR THE NORTON AND HILL CITY AREA WHERE WINDS
WILL BE THE STRONGEST INDICATES THE FUELS ARE STILL GREEN ENOUGH
NOT TO BE A CONCERN...SO WILL NOT BE ISSUING A FIRE WEATHER
HIGHLIGHT AT THIS TIME FOR THURSDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING FROM 10 AM TO 8 PM MDT WEDNESDAY FOR KSZ013-027.
CO...RED FLAG WARNING FROM 10 AM TO 8 PM MDT WEDNESDAY FOR COZ252>254.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...DR
FIRE WEATHER...DR/JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1250 PM MDT TUE MAY 15 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 1249 PM MDT TUE MAY 15 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW SHORTWAVE
RIDGE ACROSS CENTRAL ROCKIES...WITH DEEP UPPER LOW UPSTREAM OVER
NORTHERN CALIFORNIA. A COLD FRONT IS CURRENTLY JUST NORTH OF OUR
CWA...WITH TEMPERATURES AHEAD OF THE FRONT OVER OUR CWA IN THE MID
TO UPPER 80S...AND TEMPERATURES BEHIND THE FRONT IN THE MID TO
UPPER 70S.
THE COLD FRONT TO THE NORTH OF THE CWA WILL DROP SOUTH AND EAST
THIS EVENING...WITH INCREASING TD NORTH OF THE FRONT AS WINDS
SHIFT TO THE EAST-SOUTHEAST. IF TD VALUES IN THE LOW-MID 40S WERE
TO ADVECT INTO THE NORTHERN HALF OF OUR CWA...RADIATIONAL FOG
COULDNT BE RULED OUT. GUIDANCE IS CURRENTLY SHOWING BL REMAINING
UNSATURATED THROUGH WED MORNING...SO FOG WAS LEFT OUT OF
FORECAST.
LARGE SCALE SUBSIDENCE AND A VERY DRY/STABLE AIR MASS WILL REMAIN
IN PLACE THROUGH WEDNESDAY AFTERNOON. SHORTWAVE TROUGH BEGINS TO
MOVE EAST INTO THE CENTRAL ROCKIES BY WED AFTERNOON...WHICH
COULD BRING THUNDERSTORM CHANCES TO EASTERN COLORADO COUNTIES BY
LATE WEDNESDAY AFTERNOON. OVERALL TREND IS TO SLOW DOWN THE
ARRIVAL OF LIFT/MOISTURE WITH THIS FEATURE...SO I LIMITED SLIGHT
CHANCE MENTION CLOSER TO 00Z OVER NW PART OF YUMA COUNTY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 323 AM MDT TUE MAY 15 2012
WEDNESDAY NIGHT-THURSDAY NIGHT...STRONG SHORT WAVE TROUGH WILL MOVE
ACROSS THE CWA DURING THE EVENING HOURS...WITH LARGE SCALE ASCENT
INCREASING THROUGH THE EVENING HOURS AS PV ADVECTION INCREASES
THROUGH THE NIGHT. WHILE FORCING LOOKS SUFFICIENT TO SUPPORT A
PRECIPITATION THREAT...HAVE CONCERNS ABOUT COVERAGE/LIKELY HOOD ANY
PORTION OF AIR MASS WILL SATURATE ENOUGH TO SUPPORT PRECIPITATION
GIVEN MEAGER QPF OUTPUT FROM OPERATIONAL MODELS AND OVERALL LOW POPS
FROM ENSEMBLE DATA. WHILE THESE FACTORS LIMIT CONFIDENCE...THINK
SMALL POPS WARRANTED GIVEN THE STRENGTH OF THE SYSTEM. WILL SEE
ANOTHER CHANCE FOR STORMS ON THURSDAY AFTERNOON ALONG FRONTAL ZONE
ASSOCIATED WITH PV ANOMALY...MAINLY ACROSS EASTERN ZONES. POTENTIAL
LOOKS A BIT HIGHER THAN THE NIGHT BEFORE...BUT EXPECTED CLOUD COVER
IN THE MORNING AND EXPECTED POSITION OF UPPER TROUGHS HAVE TO MANY
CONCERNS ABOUT DEGREE OF DESTABILIZATION AND OVERALL LOCATION OF THE
FRONT TO GO MUCH HIGHER THAN THE 30 PERCENT RANGE AT THIS TIME.
SHORTWAVE RIDGING ON FRIDAY WILL ALLOW DAYTIME TEMPERATURES TO CLIMB
WELL ABOVE NORMAL BEFORE A RATHER STRONG SHORTWAVE TROUGH AND
ASSOCIATED COLD FRONT MOVE THROUGH THE REGION SATURDAY. GUSTY SOUTH
TO SOUTHWEST FLOW WILL DEVELOP AHEAD OF THE DEEPENING SURFACE TROUGH
WITH COOLER TEMPERATURES AND NORTHWEST WINDS BEHIND FRONTAL PASSAGE.
THERE MAY BE A CHANCE FOR SCATTERED THUNDERSTORMS TO DEVELOP AS THE
TROUGH MOVES ACROSS THE HIGH PLAINS SATURDAY AFTERNOON AND EVENING.
SURFACE HIGH PRESSURE WILL THEN MOVE INTO THE REGION WITH BROAD
UPPER LEVEL RIDGING BUILDING ACROSS THE HIGH AND CENTRAL PLAINS BY
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1136 AM MDT TUE MAY 15 2012
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD AT BOTH KGLD AND
KMCK. COLD FRONT ALREADY DROPPING SOUTH OVER KMCK WITH WINDS
SHIFTING TO THE NORTHEAST WITH GUSTS 15-17KT THROUGH SUNSET. WINDS
WILL REMAIN VARIABLE AT KGLD THROUGH ABOUT 04Z...WHEN FRONT DROPS
JUST EAST OF TERMINAL AND WINDS SHIFT TO THE SOUTHEAST AROUND
10KT. SURFACE LOW DEVELOPS BY WEDNESDAY AFTERNOON OVER EASTERN
COLORADO...WITH INCREASED GRADIENT LEADING TO GUSTY SOUTH WINDS
DEVELOPING BY 18Z. STRONGEST WINDS SHOULD OCCUR AFTER 18Z...SO I
ONLY SHOWED INCREASING TREND AFTER 15Z IN THE CURRENT TAF
PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 1249 PM MDT TUE MAY 15 2012
FIRE WEATHER WATCH FOR WED WAS UPGRADED TO RED FLAG WARNING...WITH
CONFIDENCE HIGH IN RFW CRITERIA BEING MET. WINDS ACROSS THE
WESTERN HALF OF THE AREA SHOULD BE WELL WITHIN CRITERIA WITH GUSTS
AROUND 35 MPH POSSIBLE. THERE WERE SOME QUESTIONS REGARDING TO
RH...WITH SHORTWAVE TROUGH OVER CENTRAL COLORADO POSSIBLY BRINGING
HIGHER TD VALUES INTO WESTERN PARTS OF CWA. EVEN IF MIXING WERE TO
BE LIMITED IN THE WEST AND TD VALUES REMAIN SLIGHTLY HIGHER...RH
VALUES AROUND 15-17% WOULD STILL BE EXPECTED. BASED ON LOWER MODEL
TRENDS AND BETTER MIXING...CURRENT FORECAST SHOWS RH 12-15%. WITH
WINDS GUSTING AROUND 35 MPH...RFW CRITERIA IS LIKELY UNDER EITHER
SCENARIO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING FROM 10 AM TO 8 PM MDT WEDNESDAY FOR KSZ013-027.
CO...RED FLAG WARNING FROM 10 AM TO 8 PM MDT WEDNESDAY FOR COZ252>254.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JRM/PM
AVIATION...DR
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS GAYLORD MI
148 PM EDT TUE MAY 15 2012
.SYNOPSIS...
ISSUED AT 301 AM EDT TUE MAY 15 2012
LOW PRESSURE WILL PASS NORTH OF LAKE SUPERIOR AND LAKE HURON TODAY
AND TONIGHT. THIS SYSTEM WILL PUSH A COLD FRONT ACROSS THE REGION
TONIGHT. OUR FIRE DANGER WILL REMAIN QUITE ELEVATED UNTIL THE FRONT
PASSES. IN ADDITION...SHOWERS AND A FEW THUNDERSTORMS ARE
POSSIBLE...ESPECIALLY AS THE FRONT GOES THROUGH. AFTER A WARM DAY
TODAY...MUCH COOLER WEATHER IS EXPECTED WEDNESDAY AND
THURSDAY...INCLUDING POTENTIAL FROST ON WEDNESDAY NIGHT. MUCH WARMER
WEATHER WILL ARRIVE FOR THE WEEKEND.
&&
.UPDATE...
ISSUED AT 148 PM EDT TUE MAY 15 2012
AFTERNOON DEW POINT/INSTABILITY UPDATE: DEW POINTS STILL STRUGGLE
TO CLIMB OUT OF THE 30S ACROSS MUCH OF NORTH CENTRAL/NORTHEAST
LOWER...WITH LOWER-MID 40S ACROSS SOUTHWEST QUARTER OF THE
FORECAST AREA. OBJECTIVE ANALYSES SUGGESTS 300-500J/KG MLCAPE WEST
OF I-75 IN NORTHERN LOWER WITH >50J/KG MLCINH...CORRIDOR OF
500-750J/KG MLCAPE ACROSS CENTRAL/WESTERN UPPER AND EASTERN
WISCONSIN AHEAD OF APPROACHING COLD FRONT...GETTING SOME SCATTERED
CONVECTION TO POP OVER CENTRAL UPPER ALONG THE FRONT AND CLOSER TO
UPPER VORTICITY CENTER. NOT SURE IF THIS WILL MAKE IT INTO EASTERN
UPPER WHERE INSTABILITY IS MINIMAL AS OF NOW. WILL CONTINUE TO
MONITOR...BUT LIKELY STILL SEVERAL HOURS OFF BEFORE ANYTHING
EXCITING HAPPENS OVER NORTHERN MICHIGAN.
UPDATE ISSUED AT 1054 AM EDT TUE MAY 15 2012
12Z SURFACE ANALYSIS SHOWS 1004MB LOW OVER WESTERN LAKE SUPERIOR
WITH A TRAILING COLD FRONT INTO NORTHWEST WISCONSIN/FAR SOUTHEAST
MINNESOTA. ASSOCIATED MID LEVEL SHORT WAVE TROUGH DIGGING SOUTHEAST
OUT OF NORTHWEST ONTARIO...FORCING AHEAD OF THIS WAVE PRODUCING SOME
AC/ACCAS AND SCATTERED LIGHT SHOWERS ACROSS EASTERN UPPER/FAR
NORTHERN LOWER. 12Z APX SOUNDING HAD A RESIDUAL MIXED LAYER FROM
JUST OFF THE DECK TO 700MB...MEAN MIXING RATIO WITHIN THIS LAYER
AROUND 4G/KG WITH DEW POINT DEPRESSIONS OF 14C 850MB/17C 925MB.
SHOULD BE A VERY INTERESTING AFTERNOON AS DIFFERENCES IN GUIDANCE
DEW POINT FORECASTS AND RESULTANT INSTABILITY FORECASTS HAVE SPARKED
A NICE INTRA-OFFICE DISCUSSION/DEBATE. FIRST OFF...THE OLD "BRAIN
MODEL" ADJUSTED APX SOUNDING BASED ON MIXING TO 700MB AND INCREASING
MEAN 925-850MB MIXING RATIOS INTO THE 5-6 G/KG RANGE BASED ON
UPSTREAM SOUNDINGS YIELDS A PARCEL OF 76/45 AND AN MLCAPE VALUE IN
THE VICINITY OF 500J/KG. SO IT WON`T TAKE MUCH ADDITIONAL MOISTURE
(LOWER-MID 40S DEW POINTS) TO GENERATE ENOUGH HIGH BASED CAPE TO GIN
UP SOME CONVECTION AHEAD OF COLD FRONT WHICH IS NOT EXPECTED TO
ARRIVE UNTIL THE 19-21Z TIME FRAME. LATEST RAP FORECASTS HOLDING
DEW POINTS DOWN IN THE 30S THROUGH THE AFTERNOON...PROBABLY A BIT
TOO LOW. NAM-WRF HOWEVER PUSHES DEW POINTS INTO THE LOWER-MID
50S...AND RESULTS IN FORECAST MLCAPE VALUES OVER 1500J/KG...A BIG
DIFFERENCE FROM 500J/KG WITH REGARD TO CONVECTIVE EVOLUTION/SEVERE
WEATHER POTENTIAL. GIVEN THE RATHER UNIFORM LOW LEVEL MOISTURE
PROFILES ON UPSTREAM SOUNDINGS...THINK SUSTAINED DEW POINTS IN THE
50S WILL BE HARD TO COME BY. BUT THAT WILL BE THE THING TO WATCH
FOR THE AFTERNOON...IF DEW POINTS CAN CLIMB INTO THE 50S AND STAY
THERE (SUGGEST A CERTAIN AMOUNT OF "DEPTH" TO THE LOW LEVEL MOIST
LAYER) THEN WE WILL HAVE SOME ISSUES. AS IT STANDS...GIVEN STEEP
LOW LEVEL LAPSE RATES AND DRY SUB-CLOUD LAYER DAMAGING WIND GUSTS
WOULD BE THE PRIMARY THREAT WITH ANY CONVECTION THAT DEVELOPS
(ORGANIZED OR NOT)...MORE INSTABILITY WOULD INCREASE THE THREAT FOR
HAIL AS WELL AS STRONGER WIND GUSTS. SHOULD HAVE A PRETTY GOOD
IDEA BY 18-19Z WHERE WE STAND WITH THIS...WILL ELABORATE MORE IN
EARLY AFTERNOON UPDATE.
UPDATE ISSUED AT 630 AM EDT TUE MAY 15 2012
HAVE UPDATED GRIDS TO ADJUST MORNING POPS. AREA RADARS ARE STILL
RUNNING HOT THANKS TO DRY AIR DOWN LOW...BUT GIVEN TRENDS HAVE
PUSHED POPS A BIT HIGHER...AND HAVE EXTENDED AT LEAST A SLIGHT
CHANCE FOR A SPRINKLE/SHRA INTO PART OF FAR NORTHERN LOWER MI.
AM ALSO TRYING TO FINE-TUNE PRECIP EXPECTATIONS FOR THIS
AFTERNOON/EVENING. ALL THE HIGH RESOLUTION OUTPUT I CAN FIND
(INCLUDING VARIOUS NMM/ARW OUTPUT) SUPPORT CONVECTION KICKING OFF
IN CENTRAL AND ESPECIALLY SOUTHERN SECTIONS...MAINLY BETWEEN 21Z
AND 03Z (A FEW GO SOMEWHAT EARLIER). THIS OCCURS AS THE 500MB TROF
DIGS/DEEPENS ACROSS SUPERIOR AND UPPER MI...WITH 500MB TEMPS
LOWERING TO -20C OVER NORTHERN LOWER...AND 700-500MB LAPSE RATES
INCREASING TO NEAR 8.5C/KM. CAN WE SUSTAIN SURFACE DEW POINTS TO
INITIATE DEEP CONVECTION? WE/LL BE ADVECTING IN LOW/MID 40S FROM
SOUTHERN WI/EASTERN IOWA...BUT WE/VE SEEN OUR TREMENDOUS ABILITY
TO MIX THAT OUT ON MULTIPLE OCCASIONS OVER THE LAST WEEK.
STILL...THEY ARE NOT MANY SIGNALS THAT SAY THAT NOTHING IS GOING
TO HAPPEN.
AM GOING TO KICK POPS UP TO LOW-END LIKELY IN SOUTHERN SECTIONS
LATE AFTERNOON/EARLY EVENING. (THIS LINES UP BETTER WITH OUR
SOUTHERN NEIGHBORS.) WILL ALSO UPDATE HWO TO MENTION AN ISOLATED
SVR WIND GUST POSSIBLE. NEITHER MLCAPE (500-700J/KG) NOR 0-6KM
BULK SHEAR (20-25KT) ARE IMPRESSIVE. BUT SIMPLY THE AMOUNT OF DRY
AIR SUPPORTS CONSIDERABLE EVAP COOLING POTENTIAL WITHIN
DOWNDRAFTS. STORMS WILL NOT BE WELL ORGANIZED...DOWNDRAFT AIR/COLD
POOLS ARE GOING TO OVERWHELM INSTABILITY ON THE STORM SCALE VERY
QUICKLY. NOTE THAT THIS THINKING LINES UP WITH THE SPC DAY 1
OUTLOOK...WHICH HAS A SLIGHT RISK ESSENTIALLY ON OUR SOUTHERN
DOORSTEP.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 301 AM EDT TUE MAY 15 2012
TODAY...THERE ARE A HOST OF ISSUES TO TACKLE TODAY AND THEY ARE
SOMEWHAT INTERRELATED. FIRST OFF, THE RAIN SHOWERS THAT ARE MAKING
THEIR WAY THROUGH UPPER MICHIGAN ARE FAIRLY LIGHT AND ALIGNED
ALONG THE WARM FRONT THAT IS OUT AHEAD OF THE SFC LOW HEADING INTO
WESTERN LAKE SUPERIOR. HOWEVER, THE 00Z SOUNDINGS AT INL AND MPX,
LOOK A LOT LIKE OUR 00Z SOUNDING, THAT IS VERY DRY AND WARM. SO
AGREE WITH THE MODEL SOUNDINGS THAT THE LOWER LEVELS OF THE
SOUNDINGS WILL SHOW SIGNIFICANT DRY AIR. AS THE FRONT MOVES
THROUGH THE REGION AND THE SFC LOW WITH IT, THERE WILL BE SOME
RAIN SHOWERS AND THUNDER. HOWEVER, WITH SOME MUCH DRY AIR, IT
DOESN`T LOOK LIKE MUCH WILL HIT THE GROUND A THE WARMER AIR MOVES
INTO THE REGION. THE MODELS SHOW THAT THE LARGEST AREA OF
CONVECTION WILL PROBABLY BE ON THE EAST SIDE OF THE STATE IN THE
AFTERNOON AS THE 500 MB SHORTWAVE AND THE COLD FRONT BEGIN TO
MARCH ACROSS THE REGION. WINDS PICK UP AHEAD OF THE FRONT WITH THE
SUSTAINED WINDS AROUND 15 MPH. IF THE SOUNDINGS FROM THE UPSTREAM
AREAS ARE ANYTHING TO TAKE INTO ACCOUNT, THEN WE ARE EXPECTING
THAT THE RH IN THE AFTERNOON WILL BE AROUND 20% PRIOR TO THE
FROPA. WHILE THUNDER IS POSSIBLE, AND WITH THE DRY AIR IN THE
LOWER LEVELS EXPECTED, THIS COULD BE A RARE SET UP FOR SOME DRY
LIGHTNING ACTIVITY. TEMPERATURES ARE GOING TO MAKE A RUN AT 80F IN
NE LOWER AS WELL WITH THE 850 MB TEMPERATURES SPIKING TO AROUND
13C ON BOTH THE ECMWF AND THE GFS. SO WITH THE WARM TEMPS, DRY RH,
AND WINDS, THERE WILL BE A RED FLAG WARNING ISSUED WITH THE FIRE
WEATHER PACKAGE COMING UP.
TONIGHT...ANY RAIN THAT GETS STARTED IN THE AFTERNOON WILL BE ON
THE WAY OUT AS BOTH MODELS START TO PUSH THIS SYSTEM RAPIDLY TO
THE EAST. ONCE THE FRONT GOES THROUGH THE RED FLAG WARNING WILL
EXPIRE (AROUND 01Z) WITH TEMPERATURES COOLING, BU THE WINDS WILL
SWITCH TO THE NORTHWEST AND RAMP BACK UP, INITIALLY, IT WILL TAKE
SOME TIME TO RECOVER THE RH, BUT BY 03 OR 04Z, THE TEMPERATURES
SHOULD HAVE COOLED ENOUGH FOR THE RH TO RECOVER OVERNIGHT. ALL THE
RAIN SHOULD BE OUT OF THE REGION BY 06Z. THE REST OF THE OVERNIGHT
SHOULD BE DRY.
WEDNESDAY...MODELS REMAINED CONSISTENT FOR THE DAY WITH THE SFC
HIGH BUILT INTO THE REGION. IT LOOKS LIKE THERE COULD BE SOME
RAIN SHOWERS NORTHEAST OF ANJ AS THE ECMWF DIGS ANOTHER 500 MB
SHORTWAVE INTO THE AREA NE OF ANJ, HOWEVER, FOR THE FORECAST AREA,
THE DAY SHOULD BE DRY, WITH THE HIGH BUILDING INTO THE AREA. WILL
HAVE TO WATCH FOR SOME ELEVATED FIRE ISSUES, WITH THE LOW SFC RH,
AND THE WINDS, NEAR LAKE HURON, OUT OF THE NW AT 10-15 MPH.
FARTHER WEST NOT AS FAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 301 AM EDT TUE MAY 15 2012
SUMMER WILL ASSERT ITSELF THIS WEEKEND...BUT ONLY TEMPORARILY. THE
UPPER TROF THAT STARTS IN THE EASTERN LAKES WED EVENING...WILL EJECT
TO EASTERN CANADA BY FRIDAY. THAT WILL ALLOW RIDGING TO PROGRESS
INTO THE MS VALLEY AND CENTRAL CANADA...AND OUR TEMPS WILL WARM IN
RESPONSE. HOWEVER...WE MAY HAVE SOME ACTIVE WX TO PASS THRU IN ORDER
TO GET THE WARM AIR HERE.
WED NIGHT/THURSDAY...HIGH PRESSURE WILL BE OVERHEAD WED NIGHT.
THOUGH SOME WARM ADVECTION MID/HIGH CLOUDS COULD ARRIVE FROM THE
WEST LATE AT NIGHT...SKIES WILL BE CLEAR ENOUGH LONG ENOUGH TO
READILY DECOUPLE. TEMPS WILL PLUNGE AS A RESULT...AND A FROSTY NIGHT
APPEARS INEVITABLE IN SPOTS. GUIDANCE TEMPS ARE MAINLY IN THE
30S...WITH SOME UPPER 20S IN THE USUAL COLD SPOTS. TEMPS COULD WELL
GO A FEW DEGREES COLDER THAN THIS. WILL CONTINUE TO ADVERTISE FROST
POTENTIAL IN BOTH PENINSULAS IN THE HWO (NOTE THAT WE BEGAN THE
FROST/FREEZE SEASON IN EASTERN UPPER MI YESTERDAY).
THURSDAY IS LOOKING INCREASINGLY LIKE IT WILL BE DRY. THERE/S A NICE
SURGE OF WARM ADVECTION OFF THE DECK...AS SURFACE HIGH PRESSURE
MOVES TO THE EASTERN LAKES. A SLOW-MOVING WARM FRONT WILL GRADUALLY
EXTEND EASTWARD ACROSS UPPER MI. BUT WARM ADVECTION PROGGED TO
GENERALLY BE STRONGER WITH HEIGHT...THUS THE AIRMASS IS TENDING TO
BECOME MORE STABLE WITH TIME. MID AND UPPER LEVEL MOISTURE BECOMES
PLENTIFUL DURING THE DAY (ABOVE 700MB)...BUT THE LOW LEVELS ARE
RELATIVELY DRY (BELOW 800MB). WILL HANG INTO POPS IN EASTERN
UPPER...WHERE ASCENT IS SOMEWHAT STRONGER AND WHERE THE WARM FRONT
TRIES TO POKE IN DURING THE DAY...BUT EVEN THERE GUIDANCE POPS ARE
IN THE SINGLE DIGITS TO LOWER TEENS. WE/LL SEE. THEY ARE EVEN LESS
IN NORTHERN LOWER...AND POPS WILL BE REMOVED THERE. CLOUDS WILL KEEP
MAX TEMPS IN THE 60S TO LOWER 70S.
REST OF THE FORECAST...NAM/GFS ARE IN REASONABLE AGREEMENT THAT
WE/LL SEE A BETTER (THOUGH NOT GREAT) CHANCE OF RAIN THU NIGHT...AS
THE LOW LEVEL JET DEVELOPS AND WARM/MOIST INFLOW INCREASES. BOTH
MODELS SUGGEST CENTRAL/NORTHERN PORTIONS OF THE FORECAST AREA HAVE
THE BEST CHANCE FOR RAIN. POSSIBILITY EXISTS FOR ONE MORE ROUND
DURING THE DAY ON FRIDAY (AGAIN ESPECIALLY NORTHERN SECTIONS)...
BEFORE THE WARM FRONT MORE EMPHATICALLY LIFTS TO OUR NORTH AND WE
BECOME MORE ENTRENCHED IN THE WARM SECTOR. THAT LEAVES SATURDAY DRY
AND TOASTY. STILL TOASTY SUNDAY...BUT HEIGHT FALLS BEGIN AND A COLD
FRONT IS INBOUND SUNDAY NIGHT. SO PRECIP CHANCES SUNDAY-MONDAY...
WITH MUCH COOLER TEMPS MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 141 PM EDT TUE MAY 15 2012
VFR CONDITIONS AND GUSTY NORTHWEST WINDS EXPECTED THIS AFTERNOON...
WILL WATCH POTENTIAL CONVECTIVE THREAT THROUGH THE AFTERNOON.
WINDS SHIFT TO NORTHWEST BEHIND COLD FRONT THIS EVENING...POSSIBLE
PERIOD OF MVFR CEILINGS AT PLN/APN OVERNIGHT.
&&
.MARINE...
ISSUED AT 301 AM EDT TUE MAY 15 2012
THROUGH THE FORECAST PERIOD, DESPITE THE RAMP UP OF THE WIND TODAY
PRE AND POST FRONTAL WINDS AND WAVES TODAY, TONIGHT, AND WEDNESDAY
WILL REMAIN BELOW SMALL CRAFT CRITERIA, ALTHOUGH CAN`T COUNT OUT A
HIGHER GUST ALONG NEAR THE LAND/WATER INTERFACE. ONCE THE HIGH
BUILDS BACK INTO THE REGION ON WEDNESDAY AFTERNOON, WINDS WILL
SLACKEN AND WAVES WILL SUBSIDE FOR WEDNESDAY NIGHT.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...RED FLAG WARNING UNTIL 9 PM EDT THIS EVENING FOR MIZ016>036-041-
042.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JPB
SYNOPSIS...JZ
SHORT TERM...JL
LONG TERM...JZ
MARINE...JL
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1055 AM EDT TUE MAY 15 2012
.SYNOPSIS...
ISSUED AT 301 AM EDT TUE MAY 15 2012
LOW PRESSURE WILL PASS NORTH OF LAKE SUPERIOR AND LAKE HURON TODAY
AND TONIGHT. THIS SYSTEM WILL PUSH A COLD FRONT ACROSS THE REGION
TONIGHT. OUR FIRE DANGER WILL REMAIN QUITE ELEVATED UNTIL THE FRONT
PASSES. IN ADDITION...SHOWERS AND A FEW THUNDERSTORMS ARE
POSSIBLE...ESPECIALLY AS THE FRONT GOES THROUGH. AFTER A WARM DAY
TODAY...MUCH COOLER WEATHER IS EXPECTED WEDNESDAY AND
THURSDAY...INCLUDING POTENTIAL FROST ON WEDNESDAY NIGHT. MUCH WARMER
WEATHER WILL ARRIVE FOR THE WEEKEND.
&&
.UPDATE...
ISSUED AT 1054 AM EDT TUE MAY 15 2012
12Z SURFACE ANALYSIS SHOWS 1004MB LOW OVER WESTERN LAKE SUPERIOR
WITH A TRAILING COLD FRONT INTO NORTHWEST WISCONSIN/FAR SOUTHEAST
MINNESOTA. ASSOCIATED MID LEVEL SHORT WAVE TROUGH DIGGING SOUTHEAST
OUT OF NORTHWEST ONTARIO...FORCING AHEAD OF THIS WAVE PRODUCING SOME
AC/ACCAS AND SCATTERED LIGHT SHOWERS ACROSS EASTERN UPPER/FAR
NORTHERN LOWER. 12Z APX SOUNDING HAD A RESIDUAL MIXED LAYER FROM
JUST OFF THE DECK TO 700MB...MEAN MIXING RATIO WITHIN THIS LAYER
AROUND 4G/KG WITH DEW POINT DEPRESSIONS OF 14C 850MB/17C 925MB.
SHOULD BE A VERY INTERESTING AFTERNOON AS DIFFERENCES IN GUIDANCE
DEW POINT FORECASTS AND RESULTANT INSTABILITY FORECASTS HAVE SPARKED
A NICE INTRA-OFFICE DISCUSSION/DEBATE. FIRST OFF...THE OLD "BRAIN
MODEL" ADJUSTED APX SOUNDING BASED ON MIXING TO 700MB AND INCREASING
MEAN 925-850MB MIXING RATIOS INTO THE 5-6 G/KG RANGE BASED ON
UPSTREAM SOUNDINGS YIELDS A PARCEL OF 76/45 AND AN MLCAPE VALUE IN
THE VICINITY OF 500J/KG. SO IT WON`T TAKE MUCH ADDITIONAL MOISTURE
(LOWER-MID 40S DEW POINTS) TO GENERATE ENOUGH HIGH BASED CAPE TO GIN
UP SOME CONVECTION AHEAD OF COLD FRONT WHICH IS NOT EXPECTED TO
ARRIVE UNTIL THE 19-21Z TIME FRAME. LATEST RAP FORECASTS HOLDING
DEW POINTS DOWN IN THE 30S THROUGH THE AFTERNOON...PROBABLY A BIT
TOO LOW. NAM-WRF HOWEVER PUSHES DEW POINTS INTO THE LOWER-MID
50S...AND RESULTS IN FORECAST MLCAPE VALUES OVER 1500J/KG...A BIG
DIFFERENCE FROM 500J/KG WITH REGARD TO CONVECTIVE EVOLUTION/SEVERE
WEATHER POTENTIAL. GIVEN THE RATHER UNIFORM LOW LEVEL MOISTURE
PROFILES ON UPSTREAM SOUNDINGS...THINK SUSTAINED DEW POINTS IN THE
50S WILL BE HARD TO COME BY. BUT THAT WILL BE THE THING TO WATCH
FOR THE AFTERNOON...IF DEW POINTS CAN CLIMB INTO THE 50S AND STAY
THERE (SUGGEST A CERTAIN AMOUNT OF "DEPTH" TO THE LOW LEVEL MOIST
LAYER) THEN WE WILL HAVE SOME ISSUES. AS IT STANDS...GIVEN STEEP
LOW LEVEL LAPSE RATES AND DRY SUB-CLOUD LAYER DAMAGING WIND GUSTS
WOULD BE THE PRIMARY THREAT WITH ANY CONVECTION THAT DEVELOPS
(ORGANIZED OR NOT)...MORE INSTABILITY WOULD INCREASE THE THREAT FOR
HAIL AS WELL AS STRONGER WIND GUSTS. SHOULD HAVE A PRETTY GOOD
IDEA BY 18-19Z WHERE WE STAND WITH THIS...WILL ELABORATE MORE IN
EARLY AFTERNOON UPDATE.
UPDATE ISSUED AT 630 AM EDT TUE MAY 15 2012
HAVE UPDATED GRIDS TO ADJUST MORNING POPS. AREA RADARS ARE STILL
RUNNING HOT THANKS TO DRY AIR DOWN LOW...BUT GIVEN TRENDS HAVE
PUSHED POPS A BIT HIGHER...AND HAVE EXTENDED AT LEAST A SLIGHT
CHANCE FOR A SPRINKLE/SHRA INTO PART OF FAR NORTHERN LOWER MI.
AM ALSO TRYING TO FINE-TUNE PRECIP EXPECTATIONS FOR THIS
AFTERNOON/EVENING. ALL THE HIGH RESOLUTION OUTPUT I CAN FIND
(INCLUDING VARIOUS NMM/ARW OUTPUT) SUPPORT CONVECTION KICKING OFF
IN CENTRAL AND ESPECIALLY SOUTHERN SECTIONS...MAINLY BETWEEN 21Z
AND 03Z (A FEW GO SOMEWHAT EARLIER). THIS OCCURS AS THE 500MB TROF
DIGS/DEEPENS ACROSS SUPERIOR AND UPPER MI...WITH 500MB TEMPS
LOWERING TO -20C OVER NORTHERN LOWER...AND 700-500MB LAPSE RATES
INCREASING TO NEAR 8.5C/KM. CAN WE SUSTAIN SURFACE DEW POINTS TO
INITIATE DEEP CONVECTION? WE/LL BE ADVECTING IN LOW/MID 40S FROM
SOUTHERN WI/EASTERN IOWA...BUT WE/VE SEEN OUR TREMENDOUS ABILITY
TO MIX THAT OUT ON MULTIPLE OCCASIONS OVER THE LAST WEEK.
STILL...THEY ARE NOT MANY SIGNALS THAT SAY THAT NOTHING IS GOING
TO HAPPEN.
AM GOING TO KICK POPS UP TO LOW-END LIKELY IN SOUTHERN SECTIONS
LATE AFTERNOON/EARLY EVENING. (THIS LINES UP BETTER WITH OUR
SOUTHERN NEIGHBORS.) WILL ALSO UPDATE HWO TO MENTION AN ISOLATED
SVR WIND GUST POSSIBLE. NEITHER MLCAPE (500-700J/KG) NOR 0-6KM
BULK SHEAR (20-25KT) ARE IMPRESSIVE. BUT SIMPLY THE AMOUNT OF DRY
AIR SUPPORTS CONSIDERABLE EVAP COOLING POTENTIAL WITHIN
DOWNDRAFTS. STORMS WILL NOT BE WELL ORGANIZED...DOWNDRAFT AIR/COLD
POOLS ARE GOING TO OVERWHELM INSTABILITY ON THE STORM SCALE VERY
QUICKLY. NOTE THAT THIS THINKING LINES UP WITH THE SPC DAY 1
OUTLOOK...WHICH HAS A SLIGHT RISK ESSENTIALLY ON OUR SOUTHERN
DOORSTEP.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 301 AM EDT TUE MAY 15 2012
TODAY...THERE ARE A HOST OF ISSUES TO TACKLE TODAY AND THEY ARE
SOMEWHAT INTERRELATED. FIRST OFF, THE RAIN SHOWERS THAT ARE MAKING
THEIR WAY THROUGH UPPER MICHIGAN ARE FAIRLY LIGHT AND ALIGNED
ALONG THE WARM FRONT THAT IS OUT AHEAD OF THE SFC LOW HEADING INTO
WESTERN LAKE SUPERIOR. HOWEVER, THE 00Z SOUNDINGS AT INL AND MPX,
LOOK A LOT LIKE OUR 00Z SOUNDING, THAT IS VERY DRY AND WARM. SO
AGREE WITH THE MODEL SOUNDINGS THAT THE LOWER LEVELS OF THE
SOUNDINGS WILL SHOW SIGNIFICANT DRY AIR. AS THE FRONT MOVES
THROUGH THE REGION AND THE SFC LOW WITH IT, THERE WILL BE SOME
RAIN SHOWERS AND THUNDER. HOWEVER, WITH SOME MUCH DRY AIR, IT
DOESN`T LOOK LIKE MUCH WILL HIT THE GROUND A THE WARMER AIR MOVES
INTO THE REGION. THE MODELS SHOW THAT THE LARGEST AREA OF
CONVECTION WILL PROBABLY BE ON THE EAST SIDE OF THE STATE IN THE
AFTERNOON AS THE 500 MB SHORTWAVE AND THE COLD FRONT BEGIN TO
MARCH ACROSS THE REGION. WINDS PICK UP AHEAD OF THE FRONT WITH THE
SUSTAINED WINDS AROUND 15 MPH. IF THE SOUNDINGS FROM THE UPSTREAM
AREAS ARE ANYTHING TO TAKE INTO ACCOUNT, THEN WE ARE EXPECTING
THAT THE RH IN THE AFTERNOON WILL BE AROUND 20% PRIOR TO THE
FROPA. WHILE THUNDER IS POSSIBLE, AND WITH THE DRY AIR IN THE
LOWER LEVELS EXPECTED, THIS COULD BE A RARE SET UP FOR SOME DRY
LIGHTNING ACTIVITY. TEMPERATURES ARE GOING TO MAKE A RUN AT 80F IN
NE LOWER AS WELL WITH THE 850 MB TEMPERATURES SPIKING TO AROUND
13C ON BOTH THE ECMWF AND THE GFS. SO WITH THE WARM TEMPS, DRY RH,
AND WINDS, THERE WILL BE A RED FLAG WARNING ISSUED WITH THE FIRE
WEATHER PACKAGE COMING UP.
TONIGHT...ANY RAIN THAT GETS STARTED IN THE AFTERNOON WILL BE ON
THE WAY OUT AS BOTH MODELS START TO PUSH THIS SYSTEM RAPIDLY TO
THE EAST. ONCE THE FRONT GOES THROUGH THE RED FLAG WARNING WILL
EXPIRE (AROUND 01Z) WITH TEMPERATURES COOLING, BU THE WINDS WILL
SWITCH TO THE NORTHWEST AND RAMP BACK UP, INITIALLY, IT WILL TAKE
SOME TIME TO RECOVER THE RH, BUT BY 03 OR 04Z, THE TEMPERATURES
SHOULD HAVE COOLED ENOUGH FOR THE RH TO RECOVER OVERNIGHT. ALL THE
RAIN SHOULD BE OUT OF THE REGION BY 06Z. THE REST OF THE OVERNIGHT
SHOULD BE DRY.
WEDNESDAY...MODELS REMAINED CONSISTENT FOR THE DAY WITH THE SFC
HIGH BUILT INTO THE REGION. IT LOOKS LIKE THERE COULD BE SOME
RAIN SHOWERS NORTHEAST OF ANJ AS THE ECMWF DIGS ANOTHER 500 MB
SHORTWAVE INTO THE AREA NE OF ANJ, HOWEVER, FOR THE FORECAST AREA,
THE DAY SHOULD BE DRY, WITH THE HIGH BUILDING INTO THE AREA. WILL
HAVE TO WATCH FOR SOME ELEVATED FIRE ISSUES, WITH THE LOW SFC RH,
AND THE WINDS, NEAR LAKE HURON, OUT OF THE NW AT 10-15 MPH.
FARTHER WEST NOT AS FAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 301 AM EDT TUE MAY 15 2012
SUMMER WILL ASSERT ITSELF THIS WEEKEND...BUT ONLY TEMPORARILY. THE
UPPER TROF THAT STARTS IN THE EASTERN LAKES WED EVENING...WILL EJECT
TO EASTERN CANADA BY FRIDAY. THAT WILL ALLOW RIDGING TO PROGRESS
INTO THE MS VALLEY AND CENTRAL CANADA...AND OUR TEMPS WILL WARM IN
RESPONSE. HOWEVER...WE MAY HAVE SOME ACTIVE WX TO PASS THRU IN ORDER
TO GET THE WARM AIR HERE.
WED NIGHT/THURSDAY...HIGH PRESSURE WILL BE OVERHEAD WED NIGHT.
THOUGH SOME WARM ADVECTION MID/HIGH CLOUDS COULD ARRIVE FROM THE
WEST LATE AT NIGHT...SKIES WILL BE CLEAR ENOUGH LONG ENOUGH TO
READILY DECOUPLE. TEMPS WILL PLUNGE AS A RESULT...AND A FROSTY NIGHT
APPEARS INEVITABLE IN SPOTS. GUIDANCE TEMPS ARE MAINLY IN THE
30S...WITH SOME UPPER 20S IN THE USUAL COLD SPOTS. TEMPS COULD WELL
GO A FEW DEGREES COLDER THAN THIS. WILL CONTINUE TO ADVERTISE FROST
POTENTIAL IN BOTH PENINSULAS IN THE HWO (NOTE THAT WE BEGAN THE
FROST/FREEZE SEASON IN EASTERN UPPER MI YESTERDAY).
THURSDAY IS LOOKING INCREASINGLY LIKE IT WILL BE DRY. THERE/S A NICE
SURGE OF WARM ADVECTION OFF THE DECK...AS SURFACE HIGH PRESSURE
MOVES TO THE EASTERN LAKES. A SLOW-MOVING WARM FRONT WILL GRADUALLY
EXTEND EASTWARD ACROSS UPPER MI. BUT WARM ADVECTION PROGGED TO
GENERALLY BE STRONGER WITH HEIGHT...THUS THE AIRMASS IS TENDING TO
BECOME MORE STABLE WITH TIME. MID AND UPPER LEVEL MOISTURE BECOMES
PLENTIFUL DURING THE DAY (ABOVE 700MB)...BUT THE LOW LEVELS ARE
RELATIVELY DRY (BELOW 800MB). WILL HANG INTO POPS IN EASTERN
UPPER...WHERE ASCENT IS SOMEWHAT STRONGER AND WHERE THE WARM FRONT
TRIES TO POKE IN DURING THE DAY...BUT EVEN THERE GUIDANCE POPS ARE
IN THE SINGLE DIGITS TO LOWER TEENS. WE/LL SEE. THEY ARE EVEN LESS
IN NORTHERN LOWER...AND POPS WILL BE REMOVED THERE. CLOUDS WILL KEEP
MAX TEMPS IN THE 60S TO LOWER 70S.
REST OF THE FORECAST...NAM/GFS ARE IN REASONABLE AGREEMENT THAT
WE/LL SEE A BETTER (THOUGH NOT GREAT) CHANCE OF RAIN THU NIGHT...AS
THE LOW LEVEL JET DEVELOPS AND WARM/MOIST INFLOW INCREASES. BOTH
MODELS SUGGEST CENTRAL/NORTHERN PORTIONS OF THE FORECAST AREA HAVE
THE BEST CHANCE FOR RAIN. POSSIBILITY EXISTS FOR ONE MORE ROUND
DURING THE DAY ON FRIDAY (AGAIN ESPECIALLY NORTHERN SECTIONS)...
BEFORE THE WARM FRONT MORE EMPHATICALLY LIFTS TO OUR NORTH AND WE
BECOME MORE ENTRENCHED IN THE WARM SECTOR. THAT LEAVES SATURDAY DRY
AND TOASTY. STILL TOASTY SUNDAY...BUT HEIGHT FALLS BEGIN AND A COLD
FRONT IS INBOUND SUNDAY NIGHT. SO PRECIP CHANCES SUNDAY-MONDAY...
WITH MUCH COOLER TEMPS MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 726 AM EDT TUE MAY 15 2012
MAINLY VFR...THOUGH SOME RISK FOR MVFR CIGS AT PLN/APN TONIGHT.
SMALL CHANCE FOR TSRA LATE AFTERNOON NEAR MBL/TVC.
LOW PRESSURE NEAR THUNDER BAY ONTARIO THIS MORNING...WILL GRAZE
THE NORTH COAST OF SUPERIOR AND PASS NORTH OF LAKE HURON TODAY. AN
ASSOCIATED COLD FRONT WILL CROSS NORTHERN MI LATE THIS AFTERNOON
AND EARLY THIS EVENING. SOMEWHAT GUSTY SW WINDS WILL DEVELOP THIS
MORNING...AND CONTINUE UNTIL THE FRONT MOVES THRU. HIGH BASED SHRA
AND PERHAPS A FEW TSRA WILL DEVELOP AS THE FRONT GOES THRU...
CHANCES OF TAF SITES BEING IMPACTED INCREASE AS YOU HEAD SOUTH.
(PLN SHOULD NOT BE IMPACTED AT ALL...BUT WILL SEE SOME WEAK SHRA
IN THE AREA THIS MORNING). BEHIND THE FRONT...A RELATIVELY SMALL
AREA OF LOW CLOUDS (MVFR CIGS) WILL SKIRT BY APN/PLN ON ITS WAY TO
THE SOUTH AND EAST.
&&
.MARINE...
ISSUED AT 301 AM EDT TUE MAY 15 2012
THROUGH THE FORECAST PERIOD, DESPITE THE RAMP UP OF THE WIND TODAY
PRE AND POST FRONTAL WINDS AND WAVES TODAY, TONIGHT, AND WEDNESDAY
WILL REMAIN BELOW SMALL CRAFT CRITERIA, ALTHOUGH CAN`T COUNT OUT A
HIGHER GUST ALONG NEAR THE LAND/WATER INTERFACE. ONCE THE HIGH
BUILDS BACK INTO THE REGION ON WEDNESDAY AFTERNOON, WINDS WILL
SLACKEN AND WAVES WILL SUBSIDE FOR WEDNESDAY NIGHT.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...RED FLAG WARNING UNTIL 9 PM EDT THIS EVENING FOR MIZ016>036-041-
042.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JPB
SYNOPSIS...JZ
SHORT TERM...JL
LONG TERM...JZ
AVIATION...JL
MARINE...JL
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
312 PM CDT TUE MAY 15 2012
.DISCUSSION...
A FAIRLY PROGRESSIVE UPPER LEVEL PATTERN WILL BE THE RULE ACROSS
THE NORTHERN CONUS OVER THE UPCOMING WEEK. LATEST WATER VAPOR
IMAGERY AND RAP ANALYSES SHOW A BROAD RIDGE OVER THE WEST... WITH
TROUGHING OVER THE EAST. A HEALTHY SHORTWAVE CAN BE SEEN ROTATING
SOUTHEAST ACROSS THE NORTHERN GREAT LAKES AT THE CURRENT TIME.
THIS FEATURE IS HELPING TO ENHANCE THE CU FIELD ACROSS NORTHEAST
MINNESOTA AND NORTHERN WISCONSIN... BUT ANY SHRA ARE STAYING WELL
NORTH AND EAST OF OUR AREA. THE WESTERN RIDGE WILL MOVE EAST OVER
THE NEXT FEW DAYS... GENERALLY BRINGING DRY WEATHER AND A WARMING
TREND. HOWEVER... CHANCES FOR SHRA/TSRA WILL STEADILY INCREASE
DURING THE SECOND HALF OF THE WEEK INTO THE WEEKEND... WITH AN
UPPER TROUGH EVENTUALLY PUSHING THROUGH TOWARD THE END OF THE
WEEKEND... WHICH WILL HELP PUSH A SURFACE LOW AND FRONTAL BOUNDARY
ACROSS THE REGION. FAVORED THE NAM FOR THE SHORT TERM DETAILS...
THEN TRENDED TOWARD A BLEND OF THE PREVIOUS FORECAST AND ECMWF...
WHICH WAS A BIT SLOWER TO KICK THE RIDGE EASTWARD. THE LATEST
ECMWF IS A BIT FASTER HOWEVER... WHICH MAKES THE WEEKEND FORECAST
TRICKY IN TERMS OF PINPOINTING WHEN PCPN IS MOST LIKELY.
SURFACE RIDGE WILL CONTINUE TO BUILD SOUTHEAST ACROSS THE AREA
TONIGHT... FURTHER DRYING OUT DEWPOINTS THROUGH THE EARLY
EVENING... WITH A REASONABLY COOL NIGHT EXPECTED FOR THE OVERNIGHT
HOURS. THE WESTERN PART OF THE AREA SHOULD MANAGE TO GET ON THE
BACKSIDE OF THE RIDGE BY TOMORROW AFTERNOON... WITH SOME RETURN
FLOW WORKING INTO THAT AREA BY EVENING. A BETTER LOW LEVEL JET AND
WARM ADVECTION LOOK TO SETUP ACROSS THE AREA LATER WEDNESDAY
NIGHT AS LOW PRESSURE EDGED OUT INTO THE HIGH PLAINS. A LOOK AT
FORECAST 850-500MB DIFFERENTIAL THETA-E VALUES... 850MB THETA-E
ADVECTION... AND ISENTROPIC ASCENT ON THE 305K SURFACE SUGGEST
THAT ELEVATED SHRA/TSRA MAY INITIALLY GET GOING OVER THE NORTH
CENTRAL PART OF THE AREA... BUT SHOULD WORK ITS WAY SOUTHEAST
THROUGH THE OVERNIGHT AS SATURATION OCCURS SOUTHWARD ALONG THE
ELEVATED FRONTAL BOUNDARY. SOME ACTIVITY SHOULD REMAIN FOCUSED
NEAR THE FRONTAL BOUNDARY THROUGH THE DAY ON THURSDAY INTO
THURSDAY NIGHT AS WARM ADVECTION PERSISTS IN AN AREA OF CONVECTIVE
INSTABILITY. HOWEVER... BY FRIDAY THROUGH FRIDAY NIGHT THE FOCUS OF
THIS ACTIVITY LOOKS LIKE IT SHOULD SHIFT NORTHEAST OF MOST OF THE
AREA... SO TRIMMED BACK POPS DURING THAT TIME FRAME TO MAINLY
INCLUDE ONLY THE FAR NORTHERN PORTION OF THE CWFA. BY SATURDAY WE
WILL START TO FEEL THE INFLUENCE OF THE APPROACHING SURFACE FRONT
AS THE AIRMASS ACROSS THE REGION CONTINUES TO DESTABILIZE... SO
INCREASED POPS ACROSS MUCH OF THE AREA FROM WEST TO EAST. THE
BOUNDARY ITSELF LOOKS TO MOVE ACROSS THE REGION SATURDAY NIGHT OR
EARLY SUNDAY... BUT AT THIS POINT THAT TIMING COULD EASILY SHIFT
FOR 12-24 HOURS... WHICH WILL CERTAINLY HAVE AN IMPACT ON WHEN
WIDESPREAD SHRA/TSRA IS MOST LIKELY... AS WELL AS WHETHER MUCH IF
ANY SEVERE WEATHER WILL OCCUR. THINGS LOOK TO DRY OUT MONDAY AND
TUESDAY IN THE WAKE OF THE FRONT AND UPPER TROUGH... WITH HIGH
PRESSURE QUICKLY SETTLING IN ON MONDAY... THEN THE PROGRESSIVE
PATTERN BRINGING RETURN FLOW BACK INTO THE REGION BY TUESDAY
AFTERNOON.
&&
.AVIATION.../18Z TAF ISSUANCE/
/ISSUED 1200 PM CDT TUE MAY 15 2012/
SFC HIGH PRESSURE RIDGE BUILDING OVER THE FORECAST AREA DURING THE
PERIOD. NORTHWEST WINDS DIMINISHING TO UNDER 10 KT THIS
EVENING...BECOMING LIGHT AND VARIABLE AFTER MIDNIGHT. WINDS
BECOMING SOUTHERLY 5 TO 10 KNOTS WEDNESDAY. VFR CONDITIONS
PREVAILING THROUGH WEDNESDAY EVENING.
MSP...NO AVIATION PROBLEMS OR CONCERNS DURING THE PERIOD. VFR
CONDITION PREVAILING THROUGH WED EVENING.
OUTLOOK...
THU-SAT...CHANCE OF SHRA/TSRA WITH MVFR CEILINGS POSSIBLE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
/JVM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1257 PM EDT TUE MAY 15 2012
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO SPREAD RAIN ACROSS THE AREA THROUGH
TODAY...MAINLY EAST OF ROUTE 81...BEFORE ENDING TONIGHT. SKIES
WILL CLEAR EARLY WEDNESDAY AHEAD OF A COLD FRONT. THIS FRONT WILL
MOVE THROUGH LATE WEDNESDAY WITH SHOWERS AND A FEW THUNDERSTORMS.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND BRING DRY WEATHER
FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...
BATCH OF MDT TO HVY RAIN MOVG THRU NE PA AND THE SUSQ RGN/CATSILLS
OF NY. THUS FAR NO PRBLMS BUT RR RATES OF UP TO .4 IN/HR ARE NOTED
ACRS PORTIONS OF NE PA. FORTUNATELY...BACKEDGE OF HEAVIER RAIN IS
NOW ENTERING SW LUZERNE...AND HEAVIER RAINS THIS AFTN SHUD BE
FOCUSED E OF THIS AREA WHERE ANTECEDENT RAINFALL HAS BEEN LOWER. NO
PRBLMS SO FAR FROM LACK/LUZ EMO`S. AS THIS S/WV EXITS...OTHER WEAK
IMPUSLES IN THE WSW FLOW ALOFT ARE NOTED UPSTREAM. REMNANTS OF SFC
TROF...ALSO EVIDENT IN THE 925/850 MB FCSTS FOR THIS AFTN...WILL
RESULT IN WEAK LOW LVL MSTR CONVERGENCE ACRS THE CNTRL SRN TIER
AND FINGER LAKES. RUC/GFS INDICATE POTNL CAPES UP TO NEARLY
1000 J/KG...BUT THE LOW LVL TD`S SEEM ON THE HIGH SIDE. FROM OUR
PERSPECTIVE...THE NAM LOOKED MORE RSNBL WITH CAPES IN THE 300-500
RNG. TCNTRL SRN TIER AND FINGER LAKES ARE MOST LIKELY TO SEE SOME
SUNSHINE THIS AFTN....SO ISOLD TO WDLY SCT TSRA PSBL THIS AFTN
ACRS CNTRL NY...MAINLY W OF I-81. MINOR TWEEKS TO CRNT FCST...OTRW
NO SIG CHGS.
LOW PRESSURE WILL CONTINUE TO BRING RAIN TO THE CWA THROUGH THE
DAY TODAY. MODELS SHOW A WEAK AREA OF LOW PRESSURE STALLING OVER
THE AREA TODAY, BEFORE BEING PUSHED OUT TONIGHT BY AN UPPER LEVEL
TROUGH. THE BEST LIFT WILL BE FROM THE EASTERN ZONE EASTWARD.
LOOKING AT RAINFALL ACCUMULATIONS FROM THE PRECIPITATION THAT HAS
OCCURRED, MODELS HAVE OVERDONE AMOUNTS. GOING WITH THIS SAME TREND
FOR TODAY WILL ALLOW FOR LOWER STORM TOTALS AND REINFORCE THE
FORECAST FOR NO FLOODING IN THE RIVERS. SO FAR, STORM TOTAL
FORECASTS ARE ABOUT ONE HALF TO THREE QUARTERS OF AN INCH LOWER
THAN PREVIOUSLY THOUGHT.
AS THE DAY PROGRESSES, THERE WILL ALSO BE SOME INSTABILITY IN THE
AREA. CAPES OF BETWEEN 500 AND 1000 JOULES WILL BE ACROSS THE
AREA. HOWEVER, FORCING IS WEAK AND DAYTIME HEATING WILL BE
LIMITED. SO, HAVE RAIN SHOWERS IN THE FORECAST WITH ISOLD THUNDER
FOR THE AFTERNOON, EXCEPT IN THE SE ZONES WHERE SCATTERED
THUNDERSTORMS ARE FORECAST. THIS COULD CHANGE IF CLOUDS BREAK UP
OVER THE WESTERN ZONES AND TEMPS ARE HIGHER THAN FORECAST. WILL
LOOK AT THE NEW MODEL RUNS AND POSSIBLY CHANGE THUNDERSTORM
COVERAGE WITH NEXT FORECAST ISSUANCE AT 19Z.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
LOW PRESSURE BEGINS TO SLIDE OF TO THE EAST THIS EVENING, TAKING
THE PRECIPITATION ALONG WITH IT. THIS WILL ALLOW FOR A BREAK
THROUGH A GOOD PORTION OF THE NIGHT.
WEDNESDAY WILL SEE A COLD FRONT APPROACH THE CWA FROM THE WEST. IT
LOOKS TO PROVIDE ENOUGH LIFT BY TOMORROW AFTERNOON THAT SOME
ADDITIONAL THUNDERSTORMS MAY DEVELOP, ESPECIALLY ALONG THE FRONT.
MODELS ARE INDICATING THAT THE STRONGEST LIFT WILL BE OVER THE NY
ZONES. THE FURTHER SOUTH, THE DRIER THE FRONTAL PASSAGE, ALTHOUGH
SOME SHOWERS AND STORMS COULD STILL DEVELOP OVER NEPA. CURRENT SPC
OUTLOOK HAS THE CWA IN GENERAL THUNDERSTORMS. MODELS ARE SHOWING
THAT THE BEST CAPE TOMORROW WILL BE IN THE FAR EASTERN ZONES
DURING THE AFTERNOON HOURS. THE NAM HAS ABOUT 1200 JOULES TOMORROW
AFTERNOON IN THESE AREAS.
THIS FRONT WILL MOVE QUICKLY THROUGH THE CWA AND SHOULD BE EXITING
BY TOMORROW EVENING. BEHIND IT, HIGH PRESSURE WILL BUILD IN FOR
THE REMAINDER OF THE SHORT TERM FORECAST PERIOD. THERE WILL BE A
SOMEWHAT COOLER AIR MASS IN PLACE THROUGH THURSDAY NIGHT. HIGH
TEMPS THURSDAY WILL BE IN THE LOW TO MID 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
RDG BLDG OVER THE GREAT LAKES AND NE US DOMINATES THE LONG TERM
PD. SUBTLE DFRNCS IN THE PSN OF THE RDG BY THE MODELS ALLOW FOR
SOME MINOR DAY TO DAY FCST DFRNCS FOR THE PD. IN GNRL...THE ECMWF
KEEPS THE UPR RIDGE ORIENTED DIRECTLY OVER THE FCST AREA KEEPING
THE WEAK TROF OVER THE WRN LAKES FROM AFFECTING THE AREA...WHILE
THE GFS POSITIONS THE RDG LINE FURTHER SOUTH ALLOWING FOR SOME
SHRT WV ENERGY TO TRIGGER SCT SHWRS AND TRWS...ESP LATE IN THE PD.
ALSO...GFS ALLOWS SOMEWHAT WRMR AIR INTO THE FCST AREA ON A SLY
FLOW...THEREBY KEEPING TEMPS A BIT HIER. FOR THE PD...GNRLY USED
HPC GUID ALTHOUGH DID SOME ADJUSTMENTS TWRDS THE GFS SOLN BY
BUMPING UP TEMPS AND ADDING SOME VERY LOW CHANCE AND SLGT CHANCE
POS AT THE ENDS OF THE PD. IN GNRL THOUGH...PD WILL BE DRY AND
WARM AND A MARKED CONTRAST FROM THE FIRST PART OF THE WEEK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
UPR WV SLOWLY PULLING NE AND RAIN COMING TO AN END. DRIER IS WRKG IN
BEHIND THE RAIN AND SHD SLOWLY RAISE CIGS AND VSBY TO VFR LVLS THIS
AFTN. SFC HIPRES LATE TNGT WILL BRING CLRG SKIES...BUT WITH LGT
WIND SHALLOW FOG IS XPCTD LATE. DFCLT FCST ON CONDS AS FOG SHD BE
VERY PTCHY...BUT MOST TERMINALS SHD XPCT SOME BRIEF IFR CONDS
LATE...ENDING QUICKLY AS DRY AIR AND BRIGHT SUN ABV MIX OUT THE
FOG.
STRONGER COLD FNT APRCHS LATE IN THE TAF PD AND COULD BRING SOME
SHWRS AND TRWS IN THE NORTH AND WEST BEFORE THE END OF THE PD.
.OUTLOOK...
WED AFTN...MAINLY VFR...WDLY SCT AFTN -TSRA...WITH MVFR PSBL.
THU/FRI/SAT/SUN...VFR...XCPT LATE NGT VLY FOG AFFECTING KELM.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...
SHORT TERM...SLI
LONG TERM...DGM
AVIATION...DGM/HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1134 AM EDT TUE MAY 15 2012
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO SPREAD RAIN ACROSS THE AREA THROUGH
TODAY...MAINLY EAST OF ROUTE 81...BEFORE ENDING TONIGHT. SKIES
WILL CLEAR EARLY WEDNESDAY AHEAD OF A COLD FRONT. THIS FRONT WILL
MOVE THROUGH LATE WEDNESDAY WITH SHOWERS AND A FEW THUNDERSTORMS.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND BRING DRY WEATHER
FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...
BATCH OF MDT TO HVY RAIN MOVG THRU NE PA AND THE SUSQ RGN/CATSILLS
OF NY. THUS FAR NO PRBLMS BUT RR RATES OF UP TO .4 IN/HR ARE NOTED
ACRS PORTIONS OF NE PA. FORTUNATELY...BACKEDGE OF HEAVIER RAIN IS
NOW ENTERING SW LUZERNE...AND HEAVIER RAINS THIS AFTN SHUD BE
FOCUSED E OF THIS AREA WHERE ANTECEDENT RAINFALL HAS BEEN LOWER. NO
PRBLMS SO FAR FROM LACK/LUZ EMO`S. AS THIS S/WV EXITS...OTHER WEAK
IMPUSLES IN THE WSW FLOW ALOFT ARE NOTED UPSTREAM. REMNANTS OF SFC
TROF...ALSO EVIDENT IN THE 925/850 MB FCSTS FOR THIS AFTN...WILL
RESULT IN WEAK LOW LVL MSTR CONVERGENCE ACRS THE CNTRL SRN TIER
AND FINGER LAKES. RUC/GFS INDICATE POTNL CAPES UP TO NEARLY
1000 J/KG...BUT THE LOW LVL TD`S SEEM ON THE HIGH SIDE. FROM OUR
PERSPECTIVE...THE NAM LOOKED MORE RSNBL WITH CAPES IN THE 300-500
RNG. TCNTRL SRN TIER AND FINGER LAKES ARE MOST LIKELY TO SEE SOME
SUNSHINE THIS AFTN....SO ISOLD TO WDLY SCT TSRA PSBL THIS AFTN
ACRS CNTRL NY...MAINLY W OF I-81. MINOR TWEEKS TO CRNT FCST...OTRW
NO SIG CHGS.
LOW PRESSURE WILL CONTINUE TO BRING RAIN TO THE CWA THROUGH THE
DAY TODAY. MODELS SHOW A WEAK AREA OF LOW PRESSURE STALLING OVER
THE AREA TODAY, BEFORE BEING PUSHED OUT TONIGHT BY AN UPPER LEVEL
TROUGH. THE BEST LIFT WILL BE FROM THE EASTERN ZONE EASTWARD.
LOOKING AT RAINFALL ACCUMULATIONS FROM THE PRECIPITATION THAT HAS
OCCURRED, MODELS HAVE OVERDONE AMOUNTS. GOING WITH THIS SAME TREND
FOR TODAY WILL ALLOW FOR LOWER STORM TOTALS AND REINFORCE THE
FORECAST FOR NO FLOODING IN THE RIVERS. SO FAR, STORM TOTAL
FORECASTS ARE ABOUT ONE HALF TO THREE QUARTERS OF AN INCH LOWER
THAN PREVIOUSLY THOUGHT.
AS THE DAY PROGRESSES, THERE WILL ALSO BE SOME INSTABILITY IN THE
AREA. CAPES OF BETWEEN 500 AND 1000 JOULES WILL BE ACROSS THE
AREA. HOWEVER, FORCING IS WEAK AND DAYTIME HEATING WILL BE
LIMITED. SO, HAVE RAIN SHOWERS IN THE FORECAST WITH ISOLD THUNDER
FOR THE AFTERNOON, EXCEPT IN THE SE ZONES WHERE SCATTERED
THUNDERSTORMS ARE FORECAST. THIS COULD CHANGE IF CLOUDS BREAK UP
OVER THE WESTERN ZONES AND TEMPS ARE HIGHER THAN FORECAST. WILL
LOOK AT THE NEW MODEL RUNS AND POSSIBLY CHANGE THUNDERSTORM
COVERAGE WITH NEXT FORECAST ISSUANCE AT 19Z.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
LOW PRESSURE BEGINS TO SLIDE OF TO THE EAST THIS EVENING, TAKING
THE PRECIPITATION ALONG WITH IT. THIS WILL ALLOW FOR A BREAK
THROUGH A GOOD PORTION OF THE NIGHT.
WEDNESDAY WILL SEE A COLD FRONT APPROACH THE CWA FROM THE WEST. IT
LOOKS TO PROVIDE ENOUGH LIFT BY TOMORROW AFTERNOON THAT SOME
ADDITIONAL THUNDERSTORMS MAY DEVELOP, ESPECIALLY ALONG THE FRONT.
MODELS ARE INDICATING THAT THE STRONGEST LIFT WILL BE OVER THE NY
ZONES. THE FURTHER SOUTH, THE DRIER THE FRONTAL PASSAGE, ALTHOUGH
SOME SHOWERS AND STORMS COULD STILL DEVELOP OVER NEPA. CURRENT SPC
OUTLOOK HAS THE CWA IN GENERAL THUNDERSTORMS. MODELS ARE SHOWING
THAT THE BEST CAPE TOMORROW WILL BE IN THE FAR EASTERN ZONES
DURING THE AFTERNOON HOURS. THE NAM HAS ABOUT 1200 JOULES TOMORROW
AFTERNOON IN THESE AREAS.
THIS FRONT WILL MOVE QUICKLY THROUGH THE CWA AND SHOULD BE EXITING
BY TOMORROW EVENING. BEHIND IT, HIGH PRESSURE WILL BUILD IN FOR
THE REMAINDER OF THE SHORT TERM FORECAST PERIOD. THERE WILL BE A
SOMEWHAT COOLER AIR MASS IN PLACE THROUGH THURSDAY NIGHT. HIGH
TEMPS THURSDAY WILL BE IN THE LOW TO MID 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
RDG BLDG OVER THE GREAT LAKES AND NE US DOMINATES THE LONG TERM
PD. SUBTLE DFRNCS IN THE PSN OF THE RDG BY THE MODELS ALLOW FOR
SOME MINOR DAY TO DAY FCST DFRNCS FOR THE PD. IN GNRL...THE ECMWF
KEEPS THE UPR RIDGE ORIENTED DIRECTLY OVER THE FCST AREA KEEPING
THE WEAK TROF OVER THE WRN LAKES FROM AFFECTING THE AREA...WHILE
THE GFS POSITIONS THE RDG LINE FURTHER SOUTH ALLOWING FOR SOME
SHRT WV ENERGY TO TRIGGER SCT SHWRS AND TRWS...ESP LATE IN THE PD.
ALSO...GFS ALLOWS SOMEWHAT WRMR AIR INTO THE FCST AREA ON A SLY
FLOW...THEREBY KEEPING TEMPS A BIT HIER. FOR THE PD...GNRLY USED
HPC GUID ALTHOUGH DID SOME ADJUSTMENTS TWRDS THE GFS SOLN BY
BUMPING UP TEMPS AND ADDING SOME VERY LOW CHANCE AND SLGT CHANCE
POS AT THE ENDS OF THE PD. IN GNRL THOUGH...PD WILL BE DRY AND
WARM AND A MARKED CONTRAST FROM THE FIRST PART OF THE WEEK.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
12Z UPDATE...MVFR TO IFR CONDITIONS EXPECTED THROUGH THE NEXT FEW
HOURS WITH A SLOW IMPROVEMENT TO VFR FROM MID MORNING INTO THE
AFTERNOON. HIGHLY VARIABLE FORECAST ACROSS THE TERMINALS SO HERE
ARE THE SPECIFICS.
KBGM...WORST CONDITIONS EXPECTED HERE WITH IFR CIGS AND VSBYS
THROUGH 13Z...WITH PERIODS OF LIFR CIGS AND VSBYS POSSIBLE.
SLOW IMPROVEMENT TO MVFR WILL NOT OCCUR UNTIL MID-MORNING WITH VFR
NOT UNTIL AFTERNOON.
KITH/KRME...MVFR CONDITIONS NOW MAY BRIEFLY LOWER TO IFR THROUGH
13ZBASED ON OBS TO THE SOUTH AND EAST. MVFR TO VFR BY LATE MORNING.
KSYR...A BRIEF PERIOD OF IFR/MVFR CIGS POSSIBLE THROUGH
13Z...OTHERWISE VFR WITH LIGHT SHOWERS THROUGH EARLY AFTERNOON.
KELM...IFR CIGS AND VSBYS IMPROVE TO MVFR THROUGH MID-MORNING
THEN VFR.
KAVP...MVFR LOWRING TO IFR IN THE NEXT HOUR OR SO. IFR THROUGH
MID-MORNING THEN MVFR THROUGH AFTERNOON.
MAINLY SOUTHEAST TO EAST WINDS THIS MORNING...WILL BECOME W TO NW AT
KELM/KITH/KSYR/KRME...AND W TO SW AT KBGM/KAVP THIS AFTERNOON...AT
5-10 KT.
.OUTLOOK...
TUE NGT...VFR EARLY...WITH POTNL FOR VLY FOG LATE AFFECTING KELM.
WED...MAINLY VFR...WDLY SCT AFTN -TSRA...WITH MVFR PSBL.
THU/FRI/SAT...VFR...XCPT LATE NGT VLY FOG AFFECTING KELM.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...
SHORT TERM...SLI
LONG TERM...DGM
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
938 AM EDT TUE MAY 15 2012
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO SPREAD RAIN ACROSS THE AREA THROUGH
TODAY...MAINLY EAST OF ROUTE 81...BEFORE ENDING TONIGHT. SKIES
WILL CLEAR EARLY WEDNESDAY AHEAD OF A COLD FRONT. THIS FRONT WILL
MOVE THROUGH LATE WEDNESDAY WITH SHOWERS AND A FEW THUNDERSTORMS.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND BRING DRY WEATHER
FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...
BATCH OF MDT TO HVY RAIN MOVG THRU NE PA AND THE SUSQ RGN/CATSILLS
OF NY. THUS FAR NO PRBLMS BUT RR RATES OF UP TO .4 IN/HR ARE NOTED
ACRS PORTIONS OF NE PA. FORTUNATELY...BACKEDGE OF HEAVIER RAIN IS
NOW ENTERING SW LUZERNE...AND HEAVIER RAINS THIS AFTN SHUD BE
FOCUSED E OF THIS AREA WHERE ANTECEDENT RAINFALL HAS BEEN LOWER. NO
PRBLMS SO FAR FROM LACK/LUZ EMO`S. AS THIS S/WV EXITS...OTHER WEAK
IMPUSLES IN THE WSW FLOW ALOFT ARE NOTED UPSTREAM. REMNANTS OF SFC
TROF...ALSO EVIDENT IN THE 925/850 MB FCSTS FOR THIS AFTN...WILL
RESULT IN WEAK LOW LVL MSTR CONVERGENCE ACRS THE CNTRL SRN TIER
AND FINGER LAKES. RUC/GFS INDICATE POTNL CAPES UP TO NEARLY
1000 J/KG...BUT THE LOW LVL TD`S SEEM ON THE HIGH SIDE. FROM OUR
PERSPECTIVE...THE NAM LOOKED MORE RSNBL WITH CAPES IN THE 300-500
RNG. TCNTRL SRN TIER AND FINGER LAKES ARE MOST LIKELY TO SEE SOME
SUNSHINE THIS AFTN....SO ISOLD TO WDLY SCT TSRA PSBL THIS AFTN
ACRS CNTRL NY...MAINLY W OF I-81. MINOR TWEEKS TO CRNT FCST...OTRW
NO SIG CHGS.
LOW PRESSURE WILL CONTINUE TO BRING RAIN TO THE CWA THROUGH THE
DAY TODAY. MODELS SHOW A WEAK AREA OF LOW PRESSURE STALLING OVER
THE AREA TODAY, BEFORE BEING PUSHED OUT TONIGHT BY AN UPPER LEVEL
TROUGH. THE BEST LIFT WILL BE FROM THE EASTERN ZONE EASTWARD.
LOOKING AT RAINFALL ACCUMULATIONS FROM THE PRECIPITATION THAT HAS
OCCURRED, MODELS HAVE OVERDONE AMOUNTS. GOING WITH THIS SAME TREND
FOR TODAY WILL ALLOW FOR LOWER STORM TOTALS AND REINFORCE THE
FORECAST FOR NO FLOODING IN THE RIVERS. SO FAR, STORM TOTAL
FORECASTS ARE ABOUT ONE HALF TO THREE QUARTERS OF AN INCH LOWER
THAN PREVIOUSLY THOUGHT.
AS THE DAY PROGRESSES, THERE WILL ALSO BE SOME INSTABILITY IN THE
AREA. CAPES OF BETWEEN 500 AND 1000 JOULES WILL BE ACROSS THE
AREA. HOWEVER, FORCING IS WEAK AND DAYTIME HEATING WILL BE
LIMITED. SO, HAVE RAIN SHOWERS IN THE FORECAST WITH ISOLD THUNDER
FOR THE AFTERNOON, EXCEPT IN THE SE ZONES WHERE SCATTERED
THUNDERSTORMS ARE FORECAST. THIS COULD CHANGE IF CLOUDS BREAK UP
OVER THE WESTERN ZONES AND TEMPS ARE HIGHER THAN FORECAST. WILL
LOOK AT THE NEW MODEL RUNS AND POSSIBLY CHANGE THUNDERSTORM
COVERAGE WITH NEXT FORECAST ISSUANCE AT 19Z.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
LOW PRESSURE BEGINS TO SLIDE OF TO THE EAST THIS EVENING, TAKING
THE PRECIPITATION ALONG WITH IT. THIS WILL ALLOW FOR A BREAK
THROUGH A GOOD PORTION OF THE NIGHT.
WEDNESDAY WILL SEE A COLD FRONT APPROACH THE CWA FROM THE WEST. IT
LOOKS TO PROVIDE ENOUGH LIFT BY TOMORROW AFTERNOON THAT SOME
ADDITIONAL THUNDERSTORMS MAY DEVELOP, ESPECIALLY ALONG THE FRONT.
MODELS ARE INDICATING THAT THE STRONGEST LIFT WILL BE OVER THE NY
ZONES. THE FURTHER SOUTH, THE DRIER THE FRONTAL PASSAGE, ALTHOUGH
SOME SHOWERS AND STORMS COULD STILL DEVELOP OVER NEPA. CURRENT SPC
OUTLOOK HAS THE CWA IN GENERAL THUNDERSTORMS. MODELS ARE SHOWING
THAT THE BEST CAPE TOMORROW WILL BE IN THE FAR EASTERN ZONES
DURING THE AFTERNOON HOURS. THE NAM HAS ABOUT 1200 JOULES TOMORROW
AFTERNOON IN THESE AREAS.
THIS FRONT WILL MOVE QUICKLY THROUGH THE CWA AND SHOULD BE EXITING
BY TOMORROW EVENING. BEHIND IT, HIGH PRESSURE WILL BUILD IN FOR
THE REMAINDER OF THE SHORT TERM FORECAST PERIOD. THERE WILL BE A
SOMEWHAT COOLER AIR MASS IN PLACE THROUGH THURSDAY NIGHT. HIGH
TEMPS THURSDAY WILL BE IN THE LOW TO MID 60S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
IMPRVMNT WITH A WARMING TREND FOR THE MEDIUM RNG AS THE NE U.S.
TROF BEGINS TO PULL OUT AND UPR LVL/SFC RIDGING COMMENCES. BY
LATER IN THE WEEKEND THE PTRN DOES BCM MORE FVRBL FOR THE DVLPMNT
OF SOME ISOLD/WDLY SCT -TSRA MAINLY DUE TO DIURNAL EFFECTS...AND
THE PREV 00Z EURO SUGGESTED SOME POTNL FOR MCS ACTIVITY WITH
SYSTEMS DROPPING OUT OF CANADA OVER THE WEEKEND. GFS NOT SHOWING
THIS...AND INDEED HPC POPS INDICATE A DRY FCST UNTIL MONDAY OF NXT
WEEK. WE SEE NO REASON TO TO DISAGREE. WE DID GO MORE OPTIMISTIC
WITH THE SKY COVER THAN THE HPC FCST...WITH GNRLY PARTLY
SUNNY/PARTLY CLOUDY SKIES THRU THE PD.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
12Z UPDATE...MVFR TO IFR CONDITIONS EXPECTED THROUGH THE NEXT FEW
HOURS WITH A SLOW IMPROVEMENT TO VFR FROM MID MORNING INTO THE
AFTERNOON. HIGHLY VARIABLE FORECAST ACROSS THE TERMINALS SO HERE
ARE THE SPECIFICS.
KBGM...WORST CONDITIONS EXPECTED HERE WITH IFR CIGS AND VSBYS
THROUGH 13Z...WITH PERIODS OF LIFR CIGS AND VSBYS POSSIBLE.
SLOW IMPROVEMENT TO MVFR WILL NOT OCCUR UNTIL MID-MORNING WITH VFR
NOT UNTIL AFTERNOON.
KITH/KRME...MVFR CONDITIONS NOW MAY BRIEFLY LOWER TO IFR THROUGH
13ZBASED ON OBS TO THE SOUTH AND EAST. MVFR TO VFR BY LATE MORNING.
KSYR...A BRIEF PERIOD OF IFR/MVFR CIGS POSSIBLE THROUGH
13Z...OTHERWISE VFR WITH LIGHT SHOWERS THROUGH EARLY AFTERNOON.
KELM...IFR CIGS AND VSBYS IMPROVE TO MVFR THROUGH MID-MORNING
THEN VFR.
KAVP...MVFR LOWRING TO IFR IN THE NEXT HOUR OR SO. IFR THROUGH
MID-MORNING THEN MVFR THROUGH AFTERNOON.
MAINLY SOUTHEAST TO EAST WINDS THIS MORNING...WILL BECOME W TO NW AT
KELM/KITH/KSYR/KRME...AND W TO SW AT KBGM/KAVP THIS AFTERNOON...AT
5-10 KT.
.OUTLOOK...
TUE NGT...VFR EARLY...WITH POTNL FOR VLY FOG LATE AFFECTING KELM.
WED...MAINLY VFR...WDLY SCT AFTN -TSRA...WITH MVFR PSBL.
THU/FRI/SAT...VFR...XCPT LATE NGT VLY FOG AFFECTING KELM.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
SHORT TERM...SLI
LONG TERM...HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
202 AM EDT TUE MAY 15 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE UP THE EAST COAST TONIGHT, AND SPREAD RAIN
INTO THE AREA THROUGH TUESDAY, BEFORE ENDING LATE TUESDAY AND
TUESDAY NIGHT. SKIES WILL CLEAR BRIEFLY LATE TUESDAY AND EARLY
WEDNESDAY AHEAD OF A COLD FRONT. THIS FRONT WILL MOVE THROUGH LATE
WEDNESDAY WITH SHOWERS. HIGH PRESSURE WILL BUILD IN BEHIND THE
FRONT AND BRING DRY WEATHER FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
9PM UPDATE...
WITH PRECIP ADVANCING TO THE MOHAWK VALLEY AND ELMIRA UPPED POPS.
RAINFALL AMOUNTS LAST 6 HOURS UNDER HALF AN INCH. HEAVIER RAIN
STILL EXPECTED DURING THE OVERNIGHT BUT AT THIS RATE MAY BE HARD
TO GET 2 INCHES IN THE SE. MINOR OTHER CHANGES.
625 PM UPDATE...
MINOR ADJUSTMENTS...MOSTLY FOR THE SPEED AND COVERAGE OF THE RAIN.
IN GENERAL FORECAST ON TRACK. RAINFALL AMOUNTS SO FAR UNDER AN
INCH.
PREVIOUS DISCUSSION...
MODELS STILL RESOLVING THE UPCOMING RAIN EVENT. OPERATIONAL NAM
HAS GONE BACK TO IT/S EARLIER SOLN AND BRINGS RAIN BACK TO THE
WEST WITHOUT GENERATING THE QPF BULLSEYE OVER THE ERN ZONES. SREF
MEAN SOLN IS MORE IN LINE WITH THE OPERATIONAL GFS WHICH HAS A
PCPN MAX OVER THE UPSLOPE AREAS IN THE CATSKILLS AND POCONOS.
HWVR...GFS MAX ACCUMULATED QPF OF OVER 4.5 INCHES SEEMS TOO
HIGH...AND MODEL MAY BE SUFFERING FROM CONV FEEDBACK WITH STRONG
STORMS FIRING OVER THE SE. SYSTEM HAS GOOD JET STRUCTURE WITH UPR
DIVERGENCE IN THE RR QUAD AND GOOD LL SLY INFLOW. PWATS APRCHS 2"
OVER THE EAST CST...A BIT LESS OVER THE FCST AREA.
CONSENSUS AVGD QPF PUTS 30 HR AMTS OVER THE WRN CATS APRCHG 2
INCHES...WELL BLO FFG AND HEADWATERS GUID. AREA HAS ACTUALLY BEEN A
BIT DRY AND HAS SOME OF THE HIGHEST GUID IN THEN FCST AREA.
SO...AFTER XTNSV COORD WITH SURROUNDING OFFICES HAVE DECIDED TO
HOLD OFF ON A WATCH ATTM. WILL KEEP HWO GOING WITH A MENTION OF
PTNL PRBLMS IF AMTS ARE HIGHER.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
OLD FNT IS SLOW TO MVE AS YET ANOTHER WV RIDES UP ON TUE...SLOWING
THE EWRD ADVANCE. LOOKS LIKE SOME HEAVIER RAIN COULD LINGER IN THE
EAST THRU ABT 18Z TUE AS THE WV PASSES. STILL...BNDRY REMAINS
NEARLY STATIONARY INTO EARLY WED BEFORE A STRONGER SHRT WV AND
SFC FNT APRCHS FROM THE WEST AND PUSHES IT ALONG.
WED/S FNT DOES NOT HAVE THE MOISTURE CONNECTION THAT TUE/S
DOES...SO DESPITE GOOD LL CONVERGENCE AND SUPPORT ALOFT...FNT MAY
NOT GENERATE ALL THAT MUCH PCPN. SOME MRGNL INSTABILITY DOES BRING
THE CHANCE OF CONV WITH THE FNT...ESP OVER THE NORTH NEAR THE
BETTER DYNAMICS AND SOME POOLED LL MOISTURE.
MUCH COOLER AND DRIER AIR FOLLOWS THE FNT ON THU AS A SFC HIPRES
BLDS INTO THE OH VLY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
IMPRVMNT WITH A WARMING TREND FOR THE MEDIUM RNG AS THE NE U.S.
TROF BEGINS TO PULL OUT AND UPR LVL/SFC RIDGING COMMENCES. BY
LATER IN THE WEEKEND THE PTRN DOES BCM MORE FVRBL FOR THE DVLPMNT
OF SOME ISOLD/WDLY SCT -TSRA MAINLY DUE TO DIURNAL EFFECTS...AND
THE PREV 00Z EURO SUGGESTED SOME POTNL FOR MCS ACTIVITY WITH
SYSTEMS DROPPING OUT OF CANADA OVER THE WEEKEND. GFS NOT SHOWING
THIS...AND INDEED HPC POPS INDICATE A DRY FCST UNTIL MONDAY OF NXT
WEEK. WE SEE NO REASON TO TO DISAGREE. WE DID GO MORE OPTIMISTIC
WITH THE SKY COVER THAN THE HPC FCST...WITH GNRLY PARTLY
SUNNY/PARTLY CLOUDY SKIES THRU THE PD.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
06Z UPDATE...MVFR TO IFR CONDITIONS EXPECTED THROUGH
DAYBREAK...WITH A SLOW IMPROVEMENT TO VFR FROM MID MORNING INTO
THE AFTERNOON. HIGHLY VARIABLE FORECAST ACROSS THE TERMINALS SO
HERE ARE THE SPECIFICS.
KBGM...WORST CONDITIONS EXPECTED HERE WITH IFR CIGS AND VSBYS
THROUGH DAYBREAK...WITH PERIODS OF LIFR CIGS AND VSBYS POSSIBLE.
SLOW IMPROVEMENT TO MVFR WILL NOT OCCUR UNTIL MID-MORNING WITH VFR
NOT UNTIL AFTERNOON.
KITH/KRME...CONDITIONS SHOULD GRADUALLY LOWER TO MVFR THROUGH THE
NEXT FEW HOURS. BASED ON OBS TO THE SOUTH AND EAST...IFR CIGS
APPEAR TO BE MOST LIKELY BETWEEN 09Z AND 13Z. IMPROVEMENT TO MVFR
BY MID-MORNING WITH VFR BY AFTERNOON.
KSYR...GENERALLY VFR WEATHER IS EXPECTED. AS STEADIER RAIN
APPROACHES THE TERMINAL FROM THE SOUTHEAST...LOWER CIGS (MVFR) ARE
POSSIBLE JUST PRIOR TO DAYBREAK.
KELM...SOME IFR CIGS POSSIBLE THE NEXT HOUR OR SO BUT GENERALLY
MVFR THROUGH MID-MORNING THEN VFR.
KAVP...GRADUALLY LOWERING TO MVFR BY 09Z. MOST MODEL GUIDANCE
CONTINUES TO SUGGEST IFR CIGS FOR A SIGNIFICANT PERIOD BEYOND 09Z.
CONTINUED THE COURSE BASED ON OBS TO THE SOUTHWEST...WITH IFR
THROUGH MID-MORNING THEN MVFR THROUGH AFTERNOON.
MAINLY SOUTHEAST TO EAST WINDS THIS MORNING...WILL BECOME W TO NW AT
KELM/KITH/KSYR/KRME...AND W TO SW AT KBGM/KAVP THIS AFTERNOON...AT
5-10 KT.
.OUTLOOK...
TUE NGT...VFR EARLY...WITH POTNL FOR VLY FOG LATE AFFECTING KELM.
WED...MAINLY VFR...WDLY SCT AFTN -TSRA...WITH MVFR PSBL.
THU/FRI/SAT...VFR...XCPT LATE NGT VLY FOG AFFECTING KELM.
&&
.HYDROLOGY...
IN GENERAL FLASH FLOOD AND HEADWATER GUID BLO FCSTD QPF FROM
NEARLY ALL SOURCES. OUTLIER IS THE GFS WHICH DROPS A 30 HR TTL OF
ARND 4.5 INCHES OVER THE UPR DELAWARE BASIN. THAT AMT WLD CAUSE
FLOODING ISSUES BUT CONSENSUS IS THAT THE MODEL IS SUFFERING SOME
CONV FEEDBACK ISSUES. HWVR...PLACEMENT FROM THE GFS SEEMS CORRECT
SO BEST LOCATION FOR THE HIGHEST QPF APPEARS TO BE OVER ERN
DELAWARE AND NRN SULLIVAN...IN THE DELAWARE BASIN. HERE THE TOTAL QPF
IS 2 TO 2.5 INCHES WHICH COULD CAUSE MINOR FLOODING OF THE
FLASHIER CREEKS AND STREAMS SUCH AS THE WEST BRANCH AT WALTON. TO
THE WEST OVER THE UPR AND NORTH BRANCH SUSQ BASINS...AVERAGED
AMTS WILL BE LESS SO RVRS SHD STAY WELL BLO FLOOD STAGE. FOR THE
FINGER LAKES AND CHEMUNG BASINS AMOUNTS AN INCH OR LESS SO NO
PROBLEMS EXPECTED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM/TAC
SHORT TERM...DGM
LONG TERM...
AVIATION...HEDEN
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
142 PM EDT TUE MAY 15 2012
.SYNOPSIS...
A VERY SLOW MOVING COLD FRONT WILL BE A FOCUS FOR SHOWERS AND
THUNDERSTORMS TODAY...WITH A FEW THUNDERSTORMS PRODUCING HEAVY
RAIN AND GUSTY WINDS. SHOWERS AND THUNDERSTORMS WILL DEVELOP AGAIN
WEDNESDAY BEFORE COLD FRONT MOVES OFFSHORE WEDNESDAY NIGHT. HIGH
PRESSURE WILL BUILD INTO THE REGION THURSDAY...BRINGING DRIER AND
SEASONABLE WEATHER INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2:00 PM TUESDAY...STATIONARY FRONT REMAINS TO THE WEST AS A
BROAD SOUTHWESTERLY FLOW CONTINUES ALOFT. SEA BREEZE CONVECTION
HAS FIRED AND SPC MESO-ANALYSIS PAGE SHOWS MIXED LAYER CAPE VALUES
NEAR 2000 J/KG INLAND. SHOULD SEE CONVECTION FIRE SHORTLY IN THESE
AREAS AS HEATING CONTINUES. GFS HAS BACKED OFF THE POPS INLAND FOR
OVERNIGHT BUT THE NAM AND HRRR CONTINUE TO BE QUITE AGGRESSIVE.
BACKED OFF POPS SLIGHTLY BUT WILL CONTINUE TO ADVERTISE LIKELY
VALUES MAXIMIZED AROUND 0000 UTC ACROSS WESTERN COUNTIES WITH
CHANCE ELSEWHERE. LATEST SPC DAY ONE OUTLOOK HAS NOT CHANGED FROM
EARLIER VERSIONS. FOR OVERNIGHT LOWS...WITH THE TROPICAL AIRMASS
IN PLACE CONTINUED TO GO WARMER THAN GUIDANCE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 2:00 PM TUESDAY...COLD FRONT WILL REMAIN A FOCUS FOR
CONVECTION ON WEDNESDAY AS IT MOVES SLOWLY SOUTHEAST ACROSS THE
FORECAST AREA. AIR MASS WILL REMAIN JUICY AND WARM AND AT LEAST
MARGINALLY UNSTABLE...WITH DEW POINTS WELL IN THE 60S AND P/W
VALUES OF AROUND AN INCH AND A HALF. FRONT SHOULD MOVE OFFSHORE
AROUND DAYBREAK ON THURSDAY.
LATEST GUIDANCE HINTS AT FRONT LINGERING JUST OFFSHORE INTO THE
DAYLIGHT HOURS ON THURSDAY AS AN UPPER WEAKNESS LINGERS OVER THE
EASTERN CAROLINAS. THIS WILL KEEP IN THE POSSIBILITY OF
CONVECTION ON THURSDAY...ESPECIALLY FOR THE COASTAL COUNTIES.
MODEL SOUNDINGS ALSO KEEP IN DEEP MOISTURE FOR MUCH OF THAT DAY.
HAVE RAMPED UP POPS FOR THURSDAY AS A RESULT...ALTHOUGH CONFIDENCE
NOT HIGH AT THIS POINT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 AM TUESDAY...THERE ARE TWO GUIDANCE CAMPS FOR THE
EXTENDED. THE GFS/CMC DEVELOP ELONGATED RIDGING ACROSS THE OH VLY
WITH A BAGGY TROUGH PERSISTING FROM THE WESTERN ATLANTIC INTO
FLORIDA...WHILE THE ECMWF STILL DEVELOPS A CLOSED UPPER LOW OVER THE
WESTERN ATLANTIC ABOVE A HYBRID SURFACE CYCLONE. ALTHOUGH THE ECMWF
HAS BEEN SHOWING THIS FOR SEVERAL RUNS...WEAKER BLOCKING UPSTREAM
COMBINED WITH THE VERY SIMILAR GFS/CMC AND OVERALL DRIER FORECAST
PROFILES SUGGEST MUCH LESS CHANCE OF HYBRID CYCLONE DEVELOPMENT.
STILL...SOME LOWERED HEIGHTS TROUGHING BACK TOWARDS THE SOUTHEAST
SUGGEST THAT THE GFS IS NOT GIVING UP ON THIS SOLUTION
ENTIRELY...AND EVEN SO...WOULD NOT JUMP EXCLUSIVELY ON THE CMC/GFS
BANDWAGON SINCE THIS MARKS A LARGE DEPARTURE FROM PREVIOUS
SOLUTIONS. HOWEVER...WILL GO WITH A DRY FORECAST THROUGH THE PERIOD
THANKS TO SURFACE RIDGING PERSISTING FROM THE NORTH...AND THE NOW
EXPECTED DRY/STABLE LAYERS ABOVE THE SURFACE.
WITH NE FLOW THROUGH THE PERIOD...TEMPS WILL REMAIN RIGHT AROUND
CLIMO FOR BOTH HIGHS AND LOWS...EVEN AS THICKNESSES BEGIN TO RETURN
TO MORE SUBTROPICAL LEVELS. SOME PRECIP MAY AGAIN APPROACH THE
REGION MONDAY...BUT FOR NOW WILL KEEP POP OUT OF THE FORECAST 7 DAYS
OUT.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...THERE MAY BE ENOUGH OF A DRY PUNCH ALOFT TO KEEP STORMS
FROM BEING NUMEROUS THIS AFTERNOON. THERE WILL BE TWO MAIN
AREAS...ALONG THE SEA BREEZE BOUNDARY EARLY...MAINLY OVER NORTH
CAROLINA...AND ALONG A TROUGH OVER THE WESTERN CWA TOWARDS EVENING.
THE AREA WEST WILL PROBABLY HAVE THE STRONGEST STORMS.
OVERNIGHT...CONVECTION WILL STILL BE ONGOING AND WILL LIKELY NOT DIE
OUT UNTIL AFTER MIDNIGHT...AND EVEN THEN WE MAY GET ISOLATED
ACTIVITY REACHING THE COAST. STRATUS/FOG WILL COME INTO THE PICTURE
AGAIN WITH ALL THE LOW LEVEL MOISTURE AVAILABLE. WEDNESDAY...SLOW
IMPROVEMENT IN THE CEILINGS...BUT ANOTHER ROUND OF CONVECTION LIKELY
WITH DAYTIME HEATING. CONTINUED SOUTHWEST FLOW.
EXTENDED OUTLOOK...UNSETTLED WEATHER THROUGH THURSDAY WITH A GOOD
CHANCE FOR SHOWERS/ISOLATED THUNDERSTORMS/TEMPO MVFR. VFR FRIDAY
THROUGH SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2:00 PM TUESDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE
COASTAL WATERS WITH THE SOUTH TO SOUTHWESTERLY FLOW BETWEEN A WEAK
STATIONARY FRONT TO THE WEST AND BERMUDA HIGH PRESSURE TO THE
EAST. WILL PROBABLY SEE A SIMILAR PATTERN OF WINDS BACKING OFF A
COUPLE OF KNOTS LATE TONIGHT TO NEAR TEN KNOTS AS THE GRADIENT
DECREASES SLIGHTLY. SEAS REMAIN CONSISTENT AS WELL WITH 2-4 FEET.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 2:00 PM TUESDAY...A COLD FRONT WILL DROP SLOWLY SOUTHEAST
ACROSS THE CAROLINAS ON WEDNESDAY...MOVING ACROSS THE WATERS ON
THURSDAY MORNING. SLACK GRADIENT WILL KEEP WINDS LIGHT AND
SOUTHERLY UNTIL THEN...MAINLY IN THE 10 TO 15 KT RANGE...WITH SEAS
IN THE 3 TO 4 FT RANGE. WINDS WILL SHIFT NE ON
THURSDAY...INCREASING TO AROUND 15 KTS LATE OVERNIGHT. SEAS WILL
BE IN THE 2 TO 4 FT RANGE FOR MUCH OF THURSDAY.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3:00 AM TUESDAY...HIGH PRESSURE RIDGING DOWN THE EAST COAST
WILL KEEP MODERATE-TO-STRONG NE WINDS THROUGH THE PERIOD. WINDS OF
15-20 KTS...WITH ONLY MINOR DIURNAL VARIATIONS...WILL OCCUR THROUGH
SATURDAY. ALTHOUGH A WEAK SE SWELL WILL PERSIST...THE SIGNIFICANT
WAVES WILL BE A NE WIND CHOP OF 5FT/5SEC WHICH BUILDS SEAS TO 4-5 FT
FRIDAY...WITH 6 FT SEAS DEVELOPING ON SATURDAY. CAUTIONARY HEADLINES
ARE LIKELY FRIDAY...WITH SCA CONDITIONS POSSIBLE FOR THE WEEKEND.
ONCE AGAIN...THERE WILL BE A SIGNIFICANT SHADOW REGION SW OF FRYING
PAN SHOALS...WHERE SEAS WILL PERSIST AT ONLY 1-3 FT IN THE INNER 10
NM OF AMZ252 AND AMZ254.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...SHK
SHORT TERM...REK
LONG TERM...JDW
AVIATION...DL
MARINE...REK/JDW/SHK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1030 PM EDT WED MAY 16 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTH THROUGH THE AREA THIS EVENING
OFFERING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS EARLY. HIGH
PRESSURE WILL BUILD INTO THE REGION PROVIDING DRY WEATHER THROUGH
THE REMAINDER OF THE WEEK. TEMPERATURES WILL GRADUALLY WARM TO ABOVE
NORMAL BY FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
THE SURFACE COLD FRONT HAS JUST ABOUT CLEARED THE CWA...WITH ALL
SHOWER ACTIVITY NOW SOUTH OF THE BORDERING COUNTIES. ALTHOUGH
WINDS ARE OUT OF THE NORTHEAST AT ALL LOCATIONS...THE DEWPOINT
GRADIENT IS STILL LOCATED NEAR THE OHIO RIVER...WITH DEWPOINTS IN
THE MID 50S SOUTH OF THERE (AND MUCH DRIER CONDITIONS TO THE
NORTH).
ONLY MINOR ADJUSTMENTS WERE NECESSARY TO THE FORECAST...PRIMARILY
TO END POPS AND CLEAN UP THE SKY GRIDS TO REFLECT CURRENT
CONDITIONS. LOW TEMPERATURES APPEAR TO BE ON TRACK...AND SOME
READINGS BELOW 40 ARE POSSIBLE IN CENTRAL OHIO.
PREVIOUS DISCUSSION >
UPPER LEVEL TROF TO PIVOT EAST THRU THE GREAT LAKES INTO NEW
ENGLAND/SE CANADA BY THURSDAY MORNING. ASSOCIATED COLD FRONT WHICH
EXTENDS FROM WESTERN PA THRU SW OHIO AND SRN INDIANA TO DROP
SOUTH OF THE OHIO RIVER BY LATE AFTERNOON. BOTH NAM/GFS APPEAR
OVERDONE WITH SURFACE DEWPOINTS POOLED IN THE MID 60S ALONG AND
SOUTH OF THE FRONTAL BOUNDARY. 13 KM RAP MODEL SOLN LOOKS MORE
REALISTIC WITH DEWPOINTS IN THE UPPER 50S YIELDING MARGINAL BLYR
CAPES LESS THAN 1000 J/KG ACRS SE OHIO AND NRN KY. WL CONTINUE TO
LIMIT POPS TO SLIGHT CHANCE FOR THUNDERSTORMS ACRS THESE AREAS
EARLY. SINCE CONVECTION IS STARTING TO DEVELOP WILL OPT FOR AREAL
COVERAGE WORDING...ISOLATED THUNDERSTORMS.
IN THE WAKE OF THIS FRONT SFC HIGH PRESSURE BUILDS INTO THE GREAT
LAKES OVERNIGHT. SUBSIDENCE WILL LEAD TO CLEARING SKIES. DRY AIRMASS
AND LOW LEVEL CAA WILL LEAD TO BELOW NORMAL TEMPERATURES. HAVE FCST
LOWS RANGING FROM NEAR 40 NE TO LOWER 50S FAR SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
SURFACE HIGH PRESSURE TO BUILD ACROSS THE GREAT LAKES ON THURSDAY.
DRY AIRMASS WILL RESULT IN MOSTLY SUNNY SKY CONDITIONS. EXPECT TEMPS
TO BE SLIGHTLY BELOW NORMAL. AFTER A COOL START TO THE DAY EXPECT
HIGHS TO RANGE FROM NEAR 70 NE TO THE MID 70S SW.
SURFACE HIGH PRESSURE TO SLIDE OFF TO THE EAST THURSDAY NIGHT.
EXPECT MAINLY CLEAR SKIES WITH ONLY SOME THIN HIGH LEVEL CLOUDS
SPILLING IN. HAVE FCST TEMPS RANGING FROM MID 40S NORTHEAST TO THE
LOWER 50S SOUTH.
MID/UPR LEVEL RIDGE TO BUILD INTO OHIO ON FRIDAY. EXPECT TO SEE A
GOOD DEAL OF SUNSHINE WITH JUST SOME HIGH LEVEL CLOUDINESS. UNDER
THE INFLUENCE OF WAA TEMPS WILL WARM TO VALUES ABOVE NORMAL. HAVE
FCST HIGHS FROM NEAR 80 NORTH TO THE LOWER 80S SOUTH.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
WITH AN UPPER RIDGE BUILDING OVERHEAD AND SURFACE HIGH PRESSURE
CENTERED TO THE EAST...A PERIOD OF DRY WEATHER IS INDICATED FOR
SATURDAY THROUGH MONDAY. CONFIDENCE IS RATHER HIGH FOR THIS TIME
FRAME DUE TO MODEL CONSISTENCY FROM RUN TO RUN.
AN UPPER LOW IS SHOWN TO DEVELOP OVER THE MISSISSIPPI VALLEY ON
TUESDAY...ACCOMPANIED BY INCREASING MOISTURE. THE LOW IS FORECAST TO
MOVE TO INDIANA ON WEDNESDAY. MODELS HAVE BEEN INCONSISTENT WITH THE
PATH OF THE UPPER LOW...MAKING THIS PART OF THE FORECAST LESS
CERTAIN. WENT WITH A CHANCE OF THUNDERSTORMS IN WESTERN COUNTIES ON
TUESDAY...EXPANDING TO THE WHOLE AREA ON WEDNESDAY.
WITH THE AREA IN A SOUTHERLY FLOW AND WITH CONSIDERABLE SUNSHINE TO
START...TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD. HIGHS
WILL BE MAINLY IN THE 80S SATURDAY THROUGH MONDAY...WITH INCREASING
CLOUDS AND POSSIBLE PRECIPITATION CAUSING READINGS TO SLIP TO THE
MID AND UPPER 70S BY WEDNESDAY.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
A COLD FRONT HAS PASSED THROUGH THE TAF SITES...BRINGING AN END TO
THE THREAT FOR A SHOWER OR THUNDERSTORM. A FEW CLOUDS WILL REMAIN
OVER THE SOUTHERN TAF SITES FOR AN HOUR OR TWO...BUT CLEAR
CONDITIONS ARE EXPECTED AFTER THAT WINDS BEHIND THE FRONT WILL
BECOME LESS GUSTY OVER THE NEXT FEW HOURS...AS THEY SHIFT TO THE
NORTHEAST. FOG IS NOT EXPECTED TONIGHT...WITH A VERY DRY AIR MASS
AND WINDS THAT WILL NOT BECOME COMPLETELY CALM.
NO IMPACTS TO FLIGHT CONDITIONS ARE EXPECTED FOR THURSDAY. WINDS
WILL REMAIN OUT OF THE NORTHEAST...AT AROUND 10 KNOTS OR SLIGHTLY
HIGHER.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...HATZOS/AR
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
725 PM EDT WED MAY 16 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTH THROUGH THE AREA THIS EVENING
OFFERING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS EARLY. HIGH
PRESSURE WILL BUILD INTO THE REGION PROVIDING DRY WEATHER THROUGH
THE REMAINDER OF THE WEEK. TEMPERATURES WILL GRADUALLY WARM TO ABOVE
NORMAL BY FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
UPPER LEVEL TROF TO PIVOT EAST THRU THE GREAT LAKES INTO NEW
ENGLAND/SE CANADA BY THURSDAY MORNING. ASSOCIATED COLD FRONT WHICH
EXTENDS FROM WESTERN PA THRU SW OHIO AND SRN INDIANA TO DROP
SOUTH OF THE OHIO RIVER BY LATE AFTERNOON. BOTH NAM/GFS APPEAR
OVERDONE WITH SURFACE DEWPOINTS POOLED IN THE MID 60S ALONG AND
SOUTH OF THE FRONTAL BOUNDARY. 13 KM RAP MODEL SOLN LOOKS MORE
REALISTIC WITH DEWPOINTS IN THE UPPER 50S YIELDING MARGINAL BLYR
CAPES LESS THAN 1000 J/KG ACRS SE OHIO AND NRN KY. WL CONTINUE TO
LIMIT POPS TO SLIGHT CHANCE FOR THUNDERSTORMS ACRS THESE AREAS
EARLY. SINCE CONVECTION IS STARTING TO DEVELOP WILL OPT FOR AREAL
COVERAGE WORDING...ISOLATED THUNDERSTORMS.
IN THE WAKE OF THIS FRONT SFC HIGH PRESSURE BUILDS INTO THE GREAT
LAKES OVERNIGHT. SUBSIDENCE WILL LEAD TO CLEARING SKIES. DRY AIRMASS
AND LOW LEVEL CAA WILL LEAD TO BELOW NORMAL TEMPERATURES. HAVE FCST
LOWS RANGING FROM NEAR 40 NE TO LOWER 50S FAR SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
SURFACE HIGH PRESSURE TO BUILD ACROSS THE GREAT LAKES ON THURSDAY.
DRY AIRMASS WILL RESULT IN MOSTLY SUNNY SKY CONDITIONS. EXPECT TEMPS
TO BE SLIGHTLY BELOW NORMAL. AFTER A COOL START TO THE DAY EXPECT
HIGHS TO RANGE FROM NEAR 70 NE TO THE MID 70S SW.
SURFACE HIGH PRESSURE TO SLIDE OFF TO THE EAST THURSDAY NIGHT.
EXPECT MAINLY CLEAR SKIES WITH ONLY SOME THIN HIGH LEVEL CLOUDS
SPILLING IN. HAVE FCST TEMPS RANGING FROM MID 40S NORTHEAST TO THE
LOWER 50S SOUTH.
MID/UPR LEVEL RIDGE TO BUILD INTO OHIO ON FRIDAY. EXPECT TO SEE A
GOOD DEAL OF SUNSHINE WITH JUST SOME HIGH LEVEL CLOUDINESS. UNDER
THE INFLUENCE OF WAA TEMPS WILL WARM TO VALUES ABOVE NORMAL. HAVE
FCST HIGHS FROM NEAR 80 NORTH TO THE LOWER 80S SOUTH.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
WITH AN UPPER RIDGE BUILDING OVERHEAD AND SURFACE HIGH PRESSURE
CENTERED TO THE EAST...A PERIOD OF DRY WEATHER IS INDICATED FOR
SATURDAY THROUGH MONDAY. CONFIDENCE IS RATHER HIGH FOR THIS TIME
FRAME DUE TO MODEL CONSISTENCY FROM RUN TO RUN.
AN UPPER LOW IS SHOWN TO DEVELOP OVER THE MISSISSIPPI VALLEY ON
TUESDAY...ACCOMPANIED BY INCREASING MOISTURE. THE LOW IS FORECAST TO
MOVE TO INDIANA ON WEDNESDAY. MODELS HAVE BEEN INCONSISTENT WITH THE
PATH OF THE UPPER LOW...MAKING THIS PART OF THE FORECAST LESS
CERTAIN. WENT WITH A CHANCE OF THUNDERSTORMS IN WESTERN COUNTIES ON
TUESDAY...EXPANDING TO THE WHOLE AREA ON WEDNESDAY.
WITH THE AREA IN A SOUTHERLY FLOW AND WITH CONSIDERABLE SUNSHINE TO
START...TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD. HIGHS
WILL BE MAINLY IN THE 80S SATURDAY THROUGH MONDAY...WITH INCREASING
CLOUDS AND POSSIBLE PRECIPITATION CAUSING READINGS TO SLIP TO THE
MID AND UPPER 70S BY WEDNESDAY.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
A COLD FRONT HAS PASSED THROUGH THE TAF SITES...BRINGING AN END TO
THE THREAT FOR A SHOWER OR THUNDERSTORM. A FEW CLOUDS WILL REMAIN
OVER THE SOUTHERN TAF SITES FOR AN HOUR OR TWO...BUT CLEAR
CONDITIONS ARE EXPECTED AFTER THAT WINDS BEHIND THE FRONT WILL
BECOME LESS GUSTY OVER THE NEXT FEW HOURS...AS THEY SHIFT TO THE
NORTHEAST. FOG IS NOT EXPECTED TONIGHT...WITH A VERY DRY AIR MASS
AND WINDS THAT WILL NOT BECOME COMPLETELY CALM.
NO IMPACTS TO FLIGHT CONDITIONS ARE EXPECTED FOR THURSDAY. WINDS
WILL REMAIN OUT OF THE NORTHEAST...AT AROUND 10 KNOTS OR SLIGHTLY
HIGHER.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...HATZOS
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1242 PM CDT TUE MAY 15 2012
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...THE LATEST MODEL INFO IS A LITTLE UNCERTAIN ABOUT THE
INITIATION OF AN AFTERNOON WEATHER EVENT. NOT SEEING MUCH HAPPEN
YET ACROSS THE CWA...AND THE BRUNT OF THE SHORT WAVE ENERGY LOOKS
LIKE IT WILL ROTATE THROUGH AND OVER CENTRAL AND EAST TEXAS...
WITH LESS ENERGY THIS FAR SOUTH. NONETHELESS...DECIDED TO KEEP THE
CURRENT SCATTERED CONVECTION IN THE FORECAST FOR THIS AFTERNOON...
WITH VCTS IN THE TAFS FOR THE SECOND HALF OF THE AFTERNOON. A FEW
SHOWERS ARE BEGINNING TO DEVELOP IN THE DEL RIO AREA AND EVEN
INLAND ALONG THE MIDDLE TEXAS COAST...AND THE RUC SHOWS ENERGY IN
THAT AREA RIGHT ON SCHEDULE. THUS...NOT OUT OF THE WOODS YET. WILL
GO AHEAD AND EXTEND POP CHANCES INTO EARLY EVENING FOR DELAYED
DEVELOPMENT AND POTENTIAL FOR CONVECTION UPSTREAM TO MOVE
SOUTHEAST INTO THE UPPER VALLEY AND EVENTUALLY DEEPER INTO THE
CWA.
&&
.PREV DISCUSSION... /ISSUED 652 AM CDT TUE MAY 15 2012/
DISCUSSION...TWEAKED MORNING GRIDS AS WEATHER EVENT THAT JUST
PUSHED THROUGH ALL BUT OVER. DO NOT SEE SIGNIFICANT REDEVELOPMENT
IN NEXT SIX HOURS. MAINTAINED ISOLATED SHOWERS THIS MORNING
HOWEVER...BEFORE CONVECTION REDEVELOPS AHEAD OF APPROACHING SHORT
WAVE TROUGH.
UPDATED AVIATION DISCUSSION BELOW.
AVIATION...LOW CLOUDS ARE STILL IN THE AREA AT BRO BUT HRL AND
MFE ARE VFR. EARLY MORNING CONVECTION PUSHED OFF SHORE AND NOT
EXPECTING MUCH ADDITIONAL DEVELOPMENT BEFORE ABOUT NOON. LIGHT
NORTHWEST FLOW SHOULD VEER TO NORTHEAST TODAY. APPROACHING SHORT
WAVE TROUGH AXIS WILL SWING OVERHEAD LATER TODAY...WITH POTENTIAL
FOR AREA WIDE THUNDERSTORMS CAUSING FLIGHT DELAYS. HAZARDS NEAR
THUNDERSTORMS WILL INCLUDE LIGHTNING...SMALL HAIL...GUSTY WINDS
AND TURBULENCE.
PREV DISCUSSION... /ISSUED 427 AM CDT TUE MAY 15 2012/
SHORT TERM /TODAY THROUGH WEDNESDAY/...A POSITIVELY-TILTED 500 MB
TROUGH OVER WEST TEXAS EARLY THIS MORNING WILL MOVE SOUTHEAST
OVER DEEP SOUTH TEXAS TONIGHT. AN MCS MOVING SOUTHEAST ACROSS SOUTH
CENTRAL TEXAS LAST NIGHT HAS BECOME MORE OF A LINEAR FEATURE AS IT
MOVES ACROSS THE RIO GRANDE VALLEY THIS MORNING. THE MODEL GUIDANCE
DID NOT HANDLE THIS PIECE OF SHORTWAVE ENERGY WELL ESPECIALLY IN THE
TIMING OF THE MCS. ONE INTERESTING THING OVERNIGHT WAS THE STRONG
WINDS OCCURRING BEHIND THE THUNDERSTORM COMPLEX. SURFACE
OBSERVATIONS INDICATED AN EAST WIND BETWEEN 25 AND 35 MPH WITH
HIGHER GUSTS. THE WINDS WERE SHORT LIVED ONLY LASTING FOR AN HOUR OR
SO. BRO WSR-88D VELOCITIES ALSO INDICATED 45 TO 55 KNOTS ABOUT 10 TO
12000 FEET ABOVE GROUND BEHIND THUNDERSTORMS.
THE GFS/ECMWF SOLUTIONS ARE PERSISTENT IN BRINGING ANOTHER PIECE OF
SHORTWAVE ENERGY OVER DEEP SOUTH TEXAS LATER TODAY. CONFIDENCE IS
SOMEWHAT LOW THAT MORE WIDESPREAD CONVECTIVE WILL OCCUR
TODAY...SINCE THE ATMOSPHERE HAS BECOME STABLE IN THE WAKE OF THE
PASSING CONVECTIVE COMPLEX AND THE POOR HANDLING THAT THE MODELS DID
ON THIS PREVIOUS THUNDERSTORM ACTIVITY. MODELS DO INDICATE SOME
INSTABILITY OVER THE AREA LATER TODAY. THE LATEST NAM FORECAST
SOUNDING SUGGEST CAPE VALUES OF 1140 J/KG IS POSSIBLE OVER THE AREA
LATER THIS AFTERNOON. HOWEVER ANY SEVERE STORM THREAT APPEARS TO BE
MARGINAL. STRONGER STORMS HAVE THE POSSIBILITY OF PRODUCING SMALL
HAIL AND GUSTY WINDS. HAVE LOWER POPS FOR TODAY BUT HAVE STAYED
CLOSE TO A MAV/MET MOS BLEND. HIGH TEMPERATURES THIS AFTERNOON WILL
BE IN THE MID 80S NEAR THE COAST TO THE UPPER 80S FAR INLAND.
THE MID LEVEL TROUGH AND WEAK SURFACE FRONT MOVES THROUGH THE CWA
LATE TONIGHT INTO WEDNESDAY MORNING. LEFT 20 POPS BEFORE MIDNIGHT
AND 10 POPS AFTER MIDNIGHT. LOW TEMPERATURES WILL BE IN THE UPPER
60S INLAND TO AROUND 70 NEAR THE COAST. CLEARING SKIES EXPECTED ON
WEDNESDAY AS 500 MB RIDGING BUILDS IN OVER THE DEEP SOUTH TEXAS WITH
HIGH PRESSURE AND A WEAK GRADIENT ALSO PREVAILING AT THE SURFACE.
HIGH TEMPERATURES ON WEDNESDAY WILL BE IN THE MID TO UPPER 80S NEAR
THE COAST AND LOWER 90S OVER THE WEST.
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...BENIGN CONDITIONS ARE
EXPECTED THROUGH THE LONG TERM PORTION OF THE FORECAST...WITH DRY
WEATHER AND NEAR TO ABOVE NORMAL TEMPERATURES ANTICIPATED...AS MID-
LEVEL HIGH PRESSURE GRADUALLY SHIFTS EAST FROM THE BAJA PENINSULA
TO NORTH-CENTRAL MEXICO...PRODUCING A PERSISTENT NORTHWEST-TO-
SOUTHEAST MID-LEVEL FLOW OVER DEEP SOUTH TEXAS AND THE RIO GRANDE
VALLEY.
MARINE...TODAY THROUGH WEDNESDAY...BUOY 42020 REPORTED SOUTHEAST
WINDS AROUND 8 KNOTS GUSTING TO AROUND 10 KNOTS WITH SEAS SLIGHTLY
OVER 2.3 FEET WITH A PERIOD OF 7 SECONDS AT 0250 CDT/0750 UTC.
LIGHT SOUTHEAST TO EAST WINDS THIS MORNING BECOMING NORTHEAST THIS
AFTERNOON. WINDS AND SEAS HIGHER IN AND AROUND SHOWERS AND
THUNDERSTORMS. WINDS WILL SHIFT TO THE NORTH LATE TONIGHT INTO
WEDNESDAY MORNING. GENERALLY LOW SEAS AND LIGHT TO MODERATE WINDS
ARE EXPECTED THROUGH WEDNESDAY.
WEDNESDAY NIGHT THROUGH MONDAY...LIGHT TO MODERATE WINDS AND SEAS
WILL PREVAIL ALONG THE LOWER TEXAS COAST THROUGH THE PERIOD...
WITH NO SMALL CRAFT EXERCISE CAUTION OR SMALL CRAFT ADVISORY
EXPECTED...AS HIGH PRESSURE REMAINS THE DOMINANT FEATURE OVER THE
WESTERN GULF OF MEXICO.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
54/68
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1110 PM MDT WED MAY 16 2012
.UPDATE...
ISSUED AT 827 PM MDT WED MAY 16 2012
MAIN UPDATE WAS TO REMOVE THREAT OF THUNDERSTORMS FROM EASTERN
COLORADO TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 150 PM MDT WED MAY 16 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW SHORTWAVE RIDGE
OVER WESTERN KS BEGINNING TO BREAK DOWN AS SHORTWAVE TROUGH OVER
GREAT BASIN CONTINUES TO MOVE EAST INTO THE CENTRAL ROCKIES. TIGHT
GRADIENT CURRENTLY IN PLACE ACROSS CWA NO EASTERN EXTENT OF LEE
TROUGH HAS LED TO BREEZY CONDITIONS ACROSS THE AREA...WITH WINDS
GUSTING AROUND 30KT AT SEVERAL LOCATIONS. A WARM FRONT JUST
SOUTHWEST OF GOODLAND LIFTING TO THE NORTHEAST. WEST OF THIS FRONT
RH VALUES HAVE DROPPED TO 15% OR LOWER. WITH SEVERAL LOCATIONS
ALREADY WITHIN RED FLAG CRITERIA...PLAN ON KEEPING RFW IN PLACE
THROUGH EXPIRATION (02Z).
SHORTWAVE TROUGH WILL CONTINUE TO MOVE EAST WITH LARGE SCALE ASCENT
SPREADING INTO EASTERN COLORADO. RADAR RETURNS ALREADY SHOWING
SHOWERS/THUNDERSTORMS ALONG FRONT RANGE...WITH ACTIVITY GENERALLY
MOVING FROM THE SOUTH TO NORTH. LATEST RUC/HRRR SHOW THIS ACTIVITY
REMAINING JUST EAST OF THE CWA. WITH LARGE SCALE ASCENT STILL
EXPECTED TO OVERSPREAD THE CWA...AND THE CLOSE PROXIMITY OF
ACTIVITY...I DECIDED TO LEAVE ISOLATED THUNDERSTORMS IN FORECAST
THIS EVENING.
SHORTWAVE TROUGH AXIS CURRENTLY PROGGED TO MOVE EAST ACROSS WESTERN
KS. GUIDANCE IN GENERAL AGREEMENT ON TIMING...HOWEVER STRENGTH AND
POSITION OF SHORTWAVE ARE STILL ISSUES...WITH KEEPING OUR CWA
DRY...AND OTHER GUIDANCE FAVORING THE SOUTH AND EAST LATE THURSDAY
AFTERNOON. WITH INSTABILITY/LARGE SCALE ASCENT ACROSS THE CWA
THURSDAY...SLIGHT CHANCE POPS FROM PREVIOUS FORECAST SEEMED
REASONABLE. TIGHT SURFACE GRADIENT WILL REMAIN IN PLACE OVER EASTERN
PARTS OF CWA...WITH NAM/GFS BL WINDS APPROACHING ADVISORY CRITERIA
FOR A PERIOD OF TIME THURSDAY AFTERNOON. CONFIDENCE IS NOT THERE
THAT ADVISORY CRITERIA WINDS WILL LAST 3HR...SO NO HAZARD PLANNED.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 248 PM MDT WED MAY 16 2012
THURSDAY EVENING THE SHORT WAVE TROUGH WILL CONTINUE TO MOVE EAST
ACROSS THE AREA. LATEST GUIDANCE DISAGREES WITH THE LOCATION OF THE
SHORT WAVE TROUGH DURING THE EVENING...WITH THE GFS SHIFTING THE
TROUGH FURTHER NORTH WHILE THE NAM HAS KEPT THE TROUGH OVER THE
SOUTHERN PART OF THE AREA. WITH MODELS NOT BEING CONSISTENT WITH
THE PLACEMENT OF THE SHORT WAVE TROUGH...WILL EXPAND THE SLIGHT
CHANCES TO INCLUDE THE ENTIRE AREA EAST OF THE COLORADO LINE. WITH
A DEEP WELL MIXED LAYER IN PLACE OVER THE AREA...STRONG DOWN BURST
WINDS WILL BE POSSIBLE WITH ANY THUNDERSTORM THAT DEVELOPS DURING
THE EARLY EVENING. THE SHORT WAVE TROUGH AND MID LEVEL CAPE WILL
EXIT THE AREA AROUND MIDNIGHT BRINGING ANY CHANCE FOR PRECIPITATION
TO AN END.
FRIDAY A DRY LINE SETS UP OVER THE CENTRAL PART OF THE AREA. DURING THE
MID TO LATE AFTERNOON A SHORT WAVE TROUGH MOVES OVER THE DRY LINE.
POINT SOUNDINGS FOR THE AREA SHOW THE ENVIRONMENT NEARING SATURATION
AROUND THE 500MB LEVEL ON UP...SO AM THINKING THE STORM DEVELOPMENT
WILL BE TIED TO THE LOCATION OF THE 500MB LIFT. HOWEVER CANNOT RULE
OUT ENOUGH CONVERGENCE OCCURRING OVER THE DRY LINE FOR A STORM OR TWO
TO INITIATION...SO HAVE PLACED SLIGHT CHANCES ALONG THE DRY LINE WITH
FOCUS ON THE BETTER AREA OF 500MB LIFT DURING THE LATE
AFTERNOON. WITH THE DEEP WELL MIXED ENVIRONMENT OVER THE
AREA...STRONG DOWN BURST WINDS ARE POSSIBLE WITH ANY STORM THAT
DEVELOPS DURING THE EARLY EVENING. THE SHORT WAVE TROUGH EXITS THE
AREA AROUND MIDNIGHT...BRINGING PRECIPITATION CHANCES TO AN END.
SOUTH WINDS WILL INCREASE DURING THE LATE MORNING AND AFTERNOON AS
STRONGER WINDS ABOVE THE SURFACE MIX DOWN TO THE GROUND. THE
SURFACE PRESSURE GRADIENT WILL ALSO TIGHTEN THROUGH THE AFTERNOON
AHEAD OF THE COLD FRONT THAT WILL MOVE THROUGH DURING THE OVERNIGHT
HOURS. WINDS WILL PEAK DURING THE LATE AFTERNOON...WITH GUSTS UP TO
40 MPH POSSIBLE. THE WINDS WILL EASE SOME DURING THEN EVENING AS
MIXING CEASES...BUT WILL STILL BE GUSTY DUE TO THE TIGHT PRESSURE
GRADIENT IN PLACE AHEAD OF THE COLD FRONT.
DURING THE OVERNIGHT HOURS A COLD FRONT WILL MOVE INTO THE AREA FROM
THE NORTHWEST. LATEST CROSS SECTIONS SHOW THE LIFT TO BE SITUATED
AHEAD OF THE FRONT IN THE DRIER AIR. WILL BE KEEPING THE FRONTAL
PASSAGE FOR THE OVERNIGHT PERIOD DRY AS A RESULT.
THE SATURDAY THROUGH FRIDAY PERIOD WILL START OFF WITH PRECIPITATION
CHANCES ACROSS MOST OF THE AREA SATURDAY...FOLLOWING A SHORT WAVE
TROUGH AND COLD FRONT THAT WILL MOVE THROUGH THE AREA DURING THE
DAY. BULK OF THE MOISTURE WILL BE OVER THE NORTHERN HALF OF THE
AREA...CAUSING PRECIPITATION CHANCES TO QUICKLY DECREASE OVER THE
SOUTHERN PART OF THE AREA THAT WILL BE IN THE DRIER AIR. BEHIND THE
FRONT WINDS WILL BE GUSTY...BUT SHOULD DECLINE THROUGH THE DAY AS
THE FRONT MOVES FURTHER SOUTH.
SATURDAY EVENING PRECIPITATION CHANCES CONTINUE AS THE SHORT WAVE
TROUGH MOVES ACROSS THE EASTERN PART OF THE AREA. MODELS HAVE A
SECOND SHORT WAVE TROUGH FOLLOWING THE FIRST ONE OVER THE WESTERN
PART OF THE AREA. AM NOT TOO CONFIDENT THERE WILL BE MUCH MOISTURE
FOR THE SECOND SHORT WAVE TO WORK WITH...BUT KEPT IN SLIGHT CHANCES
FOR THE REST OF THE AREA TO STAY CONSIST ANT WITH NEIGHBORS.
PRECIPITATION CHANCES RETURN WEDNESDAY TO THE EASTERN PART OF THE
AREA AS ANOTHER SHORT WAVE TROUGH MOVES ACROSS THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1106 PM MDT WED MAY 16 2012
VFR EXPECTED THROUGH THE PERIOD AT KGLD AND KMCK. MID AND HIGH
LEVEL CLOUDS WILL BE PREVALENT AHEAD OF AN UPPER LEVEL TROUGH THAT
WILL MOVE ACROSS THE TERMINALS DURING AFTERNOON AND EARLY EVENING
HOURS BEFORE EXITING THE AREA TOWARD THE END OF THE TAF PERIOD. A
FEW THUNDERSTORMS ARE EXPECTED WITH THE TROUGH PASSAGE AND BEST
GUESS IS AFTER 21Z. GIVEN THE ISOLATED NATURE WILL NOT INCLUDE A
CB MENTION AT PRESENT TIME. SOUTH WINDS AROUND 20 KTS WITH HIGHER
GUSTS EXPECTED AT KMCK AROUND 18Z-02Z.
&&
.FIRE WEATHER...
ISSUED AT 248 PM MDT WED MAY 16 2012
FRIDAY AFTERNOON SOUTH WINDS WILL STRENGTHEN...WITH GUSTS UP TO 40
MPH ACROSS THE AREA. RELATIVE HUMIDITIES WILL FALL INTO THE 10 TO
20 PERCENT RANGE DURING THE AFTERNOON FOR LOCATIONS WEST OF A
MCCOOK TO GOVE LINE...LEADING TO HAZARDOUS FIRE WEATHER
CONDITIONS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...007
SHORT TERM...DR
LONG TERM...JTL
AVIATION...DDT
FIRE WEATHER...JTL
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
516 AM EDT THU MAY 17 2012
.SYNOPSIS...
ISSUED AT 512 AM EDT THU MAY 17 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE FROM
THE PLAINS INTO CNTRL CANADA AND A DOWNSTREAM TROUGH FROM QUEBEC
INTO THE NE CONUS RESULTING IN NW FLOW THROUGH THE NRN GREAT LAKES.
AT THE SFC...HIGH PRES WAS CENTERED OVER LOWER MI WHILE LOW PRES WAS
DEVELOPING OVER THE PLAINS FROM SRN SASK INTO WRN SOUTH DAKOTA. MID
LEVEL WARM ADVECTION AHEAD OF A WARM FRONT OVER THE CNTRL PLAINS
SUPPORTED DEVELOPING SHRA AND A FEW TSRA OVER SW MN.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 512 AM EDT THU MAY 17 2012
TODAY...EXPECT THE BAND OF STRONGER 310K ISENTROPIC LIFT AND
POSITION OF THE 750-650 MB WARM FRONT TO EXPAND TO THE ENE
TODAY...PER NAM/GFS. HOWEVER...SINCE THE PCPN IS MOVING AWAY FROM
THE GREATER LOW LEVEL MOISTURE INTO THE DRY LOW LEVEL AIRMASS TO THE
EAST...PER 00Z MPX/INL/GRB SOUNDINGS...THE PCPN SHOULD REMAIN LIGHT
AND MAINLY TO THE WEST AND SOUTH OF THE CWA. LOCATIONS FROM IWD-IMT
WILL SEE THE BEST CHANCE OF ANY PCPN BUT ONLY SLIGHT CHANCE POPS
WERE INCLUDED WITH ANY PCPN AMOUNTS LESS THAN A TENTH OF AN INCH.
OTHERWISE...WAA WILL HELP PUSH TEMPS INTO THE MID 50S TO LOWER 70S
DESPITE AN INCREASE IN MID HIGH CLOUDS.
TONIGHT...THE FOCUS OF THE LLJ AND STRONGEST MOISTURE TRANSPORT IS
EXPECTED OVER NE MN AND NW WI INTO WRN LAKE SUPERIOR. AREAS OF
SHRA/TSRA SHOULD DEVELOP AND EVENTUALLY SPREAD TO THE EAST AFFECTING
MAINLY THE NW HALF OF THE CWA AS THE LLJ VEERS OVERNIGHT.
HOWEVER...THERE IS STILL SIGNIFICANT UNCERTAINTY WITH THE
TIMING/POSITION OF THE CONVECTION.
FRIDAY...ANY LEFTOVER SHRA/TSRA OVER MAINLY NORTH UPPER MI INTO LAKE
SUPERIOR SHOULD SLIDE TO THE ENE AND DIMINISH DURING THE MORNING AS
THE LLJ WEAKENS. THE COMBINATION OF BUILDING MID-LVL RDG HEIGHTS AND
850 MB WARM FRONT LIFTING WELL NORTH OF THE AREA SHOULD KEEP THE CWA
DRY FRI AFTERNOON. RESIDUAL CLOUDS FROM CONVECTION SHOULD DISSIPATE
FRI AFTERNOON ALLOWING FOR INCREASED SUNSHINE. MIXING OF 850 MB
TEMPS OF AROUND 16C TO THE SFC SHOULD ALLOW FOR HIGH TEMPS FRIDAY TO
REACH INTO THE LOWER 80S OVER WRN INTERIOR LOCATION. COOLER SRLY
FLOW OFF LAKE MI WILL KEEP INLAND HIGHS OVER ERN COUNTIES IN THE LOW
TO MID 70S.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 512 AM EDT THU MAY 17 2012
PERIOD STARTS 00Z SAT WITH A 500MB RIDGE OVER THE CWA...AND A 500MB
TROUGH OVER THE INTERMOUNTAIN WEST. AT THE SFC...994MB LOW PRESSURE
WILL BE STRETCHED E FROM ERN CO TO SRN ND...AND WITH HIGH PRESSURE
SITTING OVER THE ERN SEABOARD...THAT PUTS US UNDER S/SSW FLOW.
THAT/S RIGHT...WE WILL BE IN THE WARM SECTOR AS THE WARM FRONT
ASSOCIATED WITH THE SYSTEM TO OUR W WILL BE N OF LAKE SUPERIOR BY 00Z
SAT. AND WARM IT WILL BE WITH 850MB TEMPS AROUND 17C.
FRI NIGHT AND SAT...SOLID S/SW FLOW IN THE WARM LOW LEVELS WILL KEEP
TEMPS FROM FALLING TOO FAR FRI NIGHT...ESPECIALLY IN DOWNSLOPING
AREAS. HAVE LOW TEMPS AROUND 60 IN THE DOWNSLOPE AREAS...AND IN THE
UPPER 40S TO 50S ELSEWHERE. WITH HIGHER DEW PTS AND WAA...COULD SEE
FOG OVER MAINLY NRN LAKE SUPERIOR AND EVENTUALLY NRN LAKE MI /WHICH
WOULD LAST UNTIL FROPA SUNDAY/...WHICH I ADDED TO THE FORECAST FOR
FRI NIGHT THROUGH SUN. 850MB TEMPS STAY AROUND 17C THROUGH
SAT...WITH GOOD S/SW FLOW CONTINUING...ALLOWING MIXING TO AROUND
800MB. THIS YIELDS HIGH TEMPS IN THE 80S OVER THE W HALF AND NEAR
LAKE SUPERIOR OVER THE E HALF...WITH HIGHS IN THE 60S CLOSE TO NRN
LAKE MI DUE TO S/SSW FLOW OF THE RELATIVELY COLD LAKE. ATMOSPHERE
LOOKS TOO DRY AND TOO CAPPED FOR CONVECTION TO FORM ON SAT...WHICH
IS GOOD SINCE WE SHOULD HAVE 1500-2000J/KG OF CAPE SAT AFTERNOON.
LOWERED DEW PTS A FEW DEGREES AS MIXING WILL ALLOW DRY AIR TO GET TO
THE SFC. THIS LEADS TO MIN RH VALUES DOWN OF 25 TO 35 PERCENT OVER
THE W HALF OF UPPER MI...AND GREATER THAN 35 PERCENT RH OVER THE E
HALF. THIS BECOMES MORE PROBLEMATIC WHEN CONSIDERING WINDS WILL BE
SLY AT 15-20MPH WITH GUSTS OF 25-35MPH. LOOKS LIKE IT MAY BE A
CRITICAL FIRE WEATHER DAY...BUT THAT WILL NEED TO BE LOOKED AT MORE
CLOSELY BY LATER SHIFTS FOR POSSIBLE FIRE WEATHER HEADLINES.
SAT NIGHT THROUGH MON...BY 00Z SUN...THE UPPER TROUGH WILL HAVE MOVED
FARTHER E...WITH A SHORTWAVE TROUGH OVER MANITOBA...AND POSSIBLY
ANOTHER OVER KS/NE. THE SFC LOW WILL HAVE WEAKENED TO 1002MB AS IT
MOVED TO N OF THE MN ARROWHEAD. THIS PUTS THE COLD JUST W OF LAKE
SUPERIOR AT 00Z SUN. SAT NIGHT WILL BE ANOTHER WARM ONE WITH
CONTINUED STRONG LOW LEVEL FLOW AND WARM LOW LEVEL TEMPS. OVERNIGHT
LOWS LOOK TO BE IN THE 50S AND LOW 60S. DIFFERING MODEL SOLUTIONS
BEGIN TO LOWER CONFIDENCE ON EXACT TIMING OF THE COLD FRONT/PRECIP
DUE MAINLY WITH HOW TO HANDLE A SHORTWAVE MOVING AROUND THE MAIN
UPPER TROUGH SAT NIGHT INTO SUN. THE GFS CONTINUES TO BE THE MOST
AGGRESSIVE WITH THE SHORTWAVE...SHOWING IT STRONGER THAN PRETTY MUCH
ANY OTHER MODEL. THIS MEANS THE GFS ALSO BRINGS THE COLD FRONT
THROUGH FASTER THAN OTHER MODELS. FOR THIS REASON...WILL NOT PUT AS
MUCH OF THE GFS INTO THIS FORECAST. WITH THE IDEA THAT THE GFS IS
ABOUT 6 HOURS TOO FAST WITH FROPA...THE FRONT SHOULD MOVE OVER WRN
UPPER MI SUN AFTERNOON...AND MOVE TO ERN UPPER MI BY 12Z MON...NOTE
THE SLOW EASTWARD PROGRESSION OF THE FRONT. SBCAPES OF AROUND
1000-1500J/KG WILL BE POSSIBLE SUN AFTERNOON AHEAD OF THE
FRONT...BUT CONFIDENCE IN THIS IS A BIT LOW RIGHT NOW DUE TO MODEL
TIMING DIFFERENCES AND UNCERTAINTY IN HOW MUCH CLEARING WILL OCCUR
AHEAD OF THE FRONT. 0-6KM BULK SHEAR LOOKS TO BE AROUND
30KTS...SUFFICIENT FOR ORGANIZED CONVECTION. SO...IT LOOKS LIKE SOME
STRONG TO SEVERE STORMS WILL BE A POSSIBILITY SUN
AFTERNOON/EVENING...BUT CONFIDENCE IS STILL LIMITED. THE COLD FRONT
LOOKS TO COMPLETELY CLEAR THE CWA AROUND 18Z MON...AS THE UPPER
TROUGH AND A SFC RIDGE MOVE INTO THE WRN CWA. 850MB TEMPS OF AROUND
7C MON AFTERNOON WILL MAKE FOR COOLER TEMPS IN THE 60S...EXCEPT IN
THE 50S NEAR LAKE SUPERIOR IN THE NLY WINDS.
MON NIGHT THROUGH WED...EXPECT A GRADUAL WARMING TREND AS AN UPPER
RIDGE MOVES OVERHEAD AND SFC RIDGING SLOWLY MOVES TO E OF THE CWA BY
WED AFTERNOON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 130 AM EDT THU MAY 17 2012
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH THE PERIOD.
MAIN ITEM OF CONCERN IS POTENTIAL SHOWERS APPROACHING KIWD
TOMORROW. MUCH OF IT DEPENDS ON SHOWERS DEVELOPMENT IN THE ERN
DAKOTAS TONIGHT...WHICH WILL RIDE NE WITH THE INCREASING SRLY FLOW
THROUGH THE DAY THURSDAY. LIMITED CONFIDENCE ON THIS OCCURRING...SO
WILL LEAVE OUT OF THE FORECAST. ADDED IN LLWS TO ALL OF THE TAF
SITES FOR TOMORROW EVENING WITH THE STRONG LLVL JET MOVING OVER
UPPER MI.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EDT THU MAY 17 2012
WINDS ACROSS LAKE SUPERIOR SHOULD REMAIN BELOW 30KTS THROUGH THE
PERIOD. HIGH PRESSURE ACROSS THE UPPER GREAT LAKES WILL SHIFT TO THE
LOWER GREAT LAKES THIS AFTERNOON...BEFORE PUSHING OFF THE MID
ATLANTIC SHORELINE ON FRIDAY INTO SATURDAY. LOW PRESSURE OVER
SOUTHERN SASKATCHEWAN AND THE WESTERN DAKOTAS WILL PUSH ACROSS THE
NORTHERN AND CENTRAL PLAINS TONIGHT THROUGH SATURDAY...BEFORE
SLIDING NORTH INTO ONTARIO SATURDAY. THIS WILL ALLOW A COLD FRONT TO
PUSH ACROSS THE UPPER GREAT LAKES SUNDAY INTO EARLY MONDAY. BEHIND
THE FRONT...HIGH PRESSURE WILL BUILD IN FROM THE CENTRAL AND
NORTHERN PLAINS THROUGH TUESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MIZ006-007-013-
014-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KC
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
122 AM EDT THU MAY 17 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION PROVIDING DRY WEATHER
THROUGH THE REMAINDER OF THE WEEK. TEMPERATURES WILL GRADUALLY
WARM TO ABOVE NORMAL BY FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE SURFACE COLD FRONT HAS JUST ABOUT CLEARED THE CWA...WITH ALL
SHOWER ACTIVITY NOW SOUTH OF THE BORDERING COUNTIES. ALTHOUGH
WINDS ARE OUT OF THE NORTHEAST AT ALL LOCATIONS...THE DEWPOINT
GRADIENT IS STILL LOCATED NEAR THE OHIO RIVER...WITH DEWPOINTS IN
THE MID 50S SOUTH OF THERE (AND MUCH DRIER CONDITIONS TO THE
NORTH).
ONLY MINOR ADJUSTMENTS WERE NECESSARY TO THE FORECAST...PRIMARILY
TO END POPS AND CLEAN UP THE SKY GRIDS TO REFLECT CURRENT
CONDITIONS. LOW TEMPERATURES APPEAR TO BE ON TRACK...AND SOME
READINGS BELOW 40 ARE POSSIBLE IN CENTRAL OHIO.
PREVIOUS DISCUSSION >
UPPER LEVEL TROF TO PIVOT EAST THRU THE GREAT LAKES INTO NEW
ENGLAND/SE CANADA BY THURSDAY MORNING. ASSOCIATED COLD FRONT WHICH
EXTENDS FROM WESTERN PA THRU SW OHIO AND SRN INDIANA TO DROP
SOUTH OF THE OHIO RIVER BY LATE AFTERNOON. BOTH NAM/GFS APPEAR
OVERDONE WITH SURFACE DEWPOINTS POOLED IN THE MID 60S ALONG AND
SOUTH OF THE FRONTAL BOUNDARY. 13 KM RAP MODEL SOLN LOOKS MORE
REALISTIC WITH DEWPOINTS IN THE UPPER 50S YIELDING MARGINAL BLYR
CAPES LESS THAN 1000 J/KG ACRS SE OHIO AND NRN KY. WL CONTINUE TO
LIMIT POPS TO SLIGHT CHANCE FOR THUNDERSTORMS ACRS THESE AREAS
EARLY. SINCE CONVECTION IS STARTING TO DEVELOP WILL OPT FOR AREAL
COVERAGE WORDING...ISOLATED THUNDERSTORMS.
IN THE WAKE OF THIS FRONT SFC HIGH PRESSURE BUILDS INTO THE GREAT
LAKES OVERNIGHT. SUBSIDENCE WILL LEAD TO CLEARING SKIES. DRY AIRMASS
AND LOW LEVEL CAA WILL LEAD TO BELOW NORMAL TEMPERATURES. HAVE FCST
LOWS RANGING FROM NEAR 40 NE TO LOWER 50S FAR SOUTH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
SURFACE HIGH PRESSURE TO BUILD ACROSS THE GREAT LAKES ON THURSDAY.
DRY AIRMASS WILL RESULT IN MOSTLY SUNNY SKY CONDITIONS. EXPECT TEMPS
TO BE SLIGHTLY BELOW NORMAL. AFTER A COOL START TO THE DAY EXPECT
HIGHS TO RANGE FROM NEAR 70 NE TO THE MID 70S SW.
SURFACE HIGH PRESSURE TO SLIDE OFF TO THE EAST THURSDAY NIGHT.
EXPECT MAINLY CLEAR SKIES WITH ONLY SOME THIN HIGH LEVEL CLOUDS
SPILLING IN. HAVE FCST TEMPS RANGING FROM MID 40S NORTHEAST TO THE
LOWER 50S SOUTH.
MID/UPR LEVEL RIDGE TO BUILD INTO OHIO ON FRIDAY. EXPECT TO SEE A
GOOD DEAL OF SUNSHINE WITH JUST SOME HIGH LEVEL CLOUDINESS. UNDER
THE INFLUENCE OF WAA TEMPS WILL WARM TO VALUES ABOVE NORMAL. HAVE
FCST HIGHS FROM NEAR 80 NORTH TO THE LOWER 80S SOUTH.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
WITH AN UPPER RIDGE BUILDING OVERHEAD AND SURFACE HIGH PRESSURE
CENTERED TO THE EAST...A PERIOD OF DRY WEATHER IS INDICATED FOR
SATURDAY THROUGH MONDAY. CONFIDENCE IS RATHER HIGH FOR THIS TIME
FRAME DUE TO MODEL CONSISTENCY FROM RUN TO RUN.
AN UPPER LOW IS SHOWN TO DEVELOP OVER THE MISSISSIPPI VALLEY ON
TUESDAY...ACCOMPANIED BY INCREASING MOISTURE. THE LOW IS FORECAST TO
MOVE TO INDIANA ON WEDNESDAY. MODELS HAVE BEEN INCONSISTENT WITH THE
PATH OF THE UPPER LOW...MAKING THIS PART OF THE FORECAST LESS
CERTAIN. WENT WITH A CHANCE OF THUNDERSTORMS IN WESTERN COUNTIES ON
TUESDAY...EXPANDING TO THE WHOLE AREA ON WEDNESDAY.
WITH THE AREA IN A SOUTHERLY FLOW AND WITH CONSIDERABLE SUNSHINE TO
START...TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD. HIGHS
WILL BE MAINLY IN THE 80S SATURDAY THROUGH MONDAY...WITH INCREASING
CLOUDS AND POSSIBLE PRECIPITATION CAUSING READINGS TO SLIP TO THE
MID AND UPPER 70S BY WEDNESDAY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE AND AN ASSOCIATED DRY AIRMASS WILL REMAIN IN PLACE
ACROSS THE REGION THROUGH TONIGHT. VFR CONDITIONS ARE EXPECTED
THROUGH THE TAF PERIOD.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...HATZOS/AR
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS PORTLAND OR
928 PM PDT WED MAY 16 2012
.SYNOPSIS...ONSHORE FLOW WILL CONTINUE AS A WEAK UPPER LEVEL
TROUGH APPROACHES TONIGHT AND CROSSES THURSDAY. LOW CLOUDS WILL
SPREAD INLAND BY THURSDAY EVENING WITH PATCHY DRIZZLE POSSIBLE AS
THE UPPER TROUGH MOVES EAST THURSDAY NIGHT AND FRIDAY. MOST AREAS
WILL REMAIN DRY THROUGH THE WEEKEND. A RETURN TO WET WEATHER IS
LIKELY NEXT WEEK.
&&
.SHORT TERM...TONIGHT THROUGH SATURDAY...MINIMAL CLOUD COVER THIS
EVENING WITH HIGH CLOUDS REMAINING DOMINANT..ALBEIT THIN. SURFACE
DEWPOINTS CONTINUE TO DROP AS WELL BOTH INLAND AND TO A LESSER AMOUNT
AT THE COAST. AS SUCH...FEEL PREVIOUS THOUGHTS OF LOW CLOUDS
PROGRESSING INLAND MAY NOT MATERIALIZE. UPDATE WILL BE AVAILABLE
SHORTLY TO REDUCE CLOUD COVER FROM THE OVERNIGHT PERIOD AND EARLY
TOMORROW MORNING. AS AN UPPER TROUGH SLIDES ACROSS THE REGION
TOMORROW...EXPECT MARINE MOISTURE WILL STAND A BETTER CHANCE OF
STRENGTHENING AND PUSHING INLAND SO WILL LEAVE THE HIGHER CLOUD COVER
IN PLACE FOR TOMORROW AFTERNOON AND THEREAFTER. BY REMOVING
CLOUDS...HAVE ALSO DROPPED TEMPERATURES TONIGHT CLOSER TO WHAT WAS
SEEN LAST NIGHT OR EVEN A LITTLE COOLER.
EXTENSIVE LOW CLOUDS LOOK TO CONTINUE FRI MORNING AS ONSHORE FLOW
CONTINUES AND THE MARINE LAYER REMAINS DEEP...WITH SOME DRIZZLE OR
ISOLATED SHOWERS POSSIBLE OVER THE HIGHER TERRAIN. THE CLOUD COVER
AND COOLER AIR MASS WILL KEEP TEMPERATURES BELOW NORMAL LEVELS
THURSDAY AND FRIDAY.
HIGH PRESSURE WILL AGAIN BUILD INTO THE PACIFIC NORTHWEST SATURDAY
FOR A RETURN TO DRY SUNNY WEATHER WITH TEMPERATURES WARMING UP TO
NEAR 70 DEGREES. /JBONK
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...THE EXTENDED
FORECAST PERIOD BEGINS SATURDAY EVENING AS UPPER LEVEL RIDGING OVER
THE PACIFIC NORTHWEST IS ABOUT TO BREAK DOWN AND OPEN THE DOOR FOR
COOLER AND WETTER WEATHER AFTER SUNDAY. AN UPPER TROUGH APPROACHES
THE AREA...BRINGING A FRONT ONSHORE MONDAY. AS THE FRONT MOVES
THROUGH...THE JET STREAM DIPS SOUTH AND STRENGTHENS OVER THE EASTERN
PACIFIC. THIS DIRECTS A STORM TRACK AT THE NORTHWEST COAST THROUGH
ABOUT MIDWEEK. MODELS BEGIN TO DISAGREE AFTER MIDWEEK THOUGH AS THE
GFS AND THE GEM BUILD A RELATIVELY HIGH AMPLITUDE RIDGE OFFSHORE
WITH A TROUGH OVER THE WEST COAST. THE ECMWF LEANS TOWARD A MORE
ZONAL FLOW WITH POTENTIALLY WETTER WEATHER ON THE WAY. EITHER
WAY...IT APPEARS THAT THE SHORT BOUT OF SUNNY WEATHER MAY BE
TEMPORARILY ENDING. KELSON
&&
.AVIATION...MVFR STRATUS IS LINGERING NEAR THE COLUMBIA RIVER
MOUTH...WITH SOME PATCHY FOG FURTHER SOUTH ALONG THE IMMEDIATE
COASTLINE NEAR KONP. EXPECT IFR/MVFR STRATUS TO REDEVELOP ALONG
THE COAST OVERNIGHT BEFORE POSSIBLY SPREADING INLAND LATE
TONIGHT...PARTICULARLY ALONG THE COLUMBIA RIVER.
AT THIS TIME...MODELS INCLUDING THE RAP AND NAM CONTINUE TO SUGGEST
STRATUS SPREADING DOWN THE COLUMBIA RIVER. THE HI RESOLUTION RAPID
REFRESH MODELS DOES INDICATE SOME INLAND PENETRATION DOWN THE
RIVER...BUT NOT TO THE INLAND TAF SITES AND NOT THROUGH THE COASTAL
GAPS. THEREFORE CONFIDENCE AT THIS TIME IS LOW IN SEEING INLAND
STRATUS...AND WILL ELIMINATE THE BROKEN CEILING AND JUST LEAVE A
SCATTERED MENTION FOR NOW. THAT SAID...WE DO HAVE AN UPPER TROUGH
MOVING IN WHICH MAY ACT TO STRENGTHEN THE MARINE LAYER. IF IT DOES
DEVELOP ACROSS THE INTERIOR...IT SHOULD BURN OFF FAIRLY QUICKLY
THURSDAY. EXPECT A DIURNAL INCREASE IN NW WINDS LATE AFTERNOON AND
EARLY EVENING. KMD
&&
.MARINE...HIGH PRESSURE CENTERED NEAR 50 N/140W WILL WEAKEN SLOWLY
THE NEXT FEW DAYS AND MIGRATE CLOSER TO SHORE. MARGINAL SMALL CRAFT
ADVISORY LEVEL WINDS WILL CONTINUE MAINLY OVER THE OUTER WATERS WITH
ONSHORE NNW FLOW. WINDS PEAK IN THE AFTERNOON THURSDAY...BEFORE
EASING FRIDAY AS HIGH PRESSURE BECOMES CENTERED OVER THE COASTAL
WATERS. THIS WILL OPEN THE DOOR FOR A WEATHER PATTERN CHANGE...AND
ALLOW A FEW PACIFIC FRONTAL SYSTEMS TO MOVE INTO THE WATERS NEXT
WEEK.
THE PROLONGED NW WINDS STILL APPEAR LIKELY TO DRIVE SEAS UP TO NEAR
10 TO 11 FT BY THURSDAY ACROSS THE NORTHERN OUTER WATERS...BEFORE
SUBSIDING THURSDAY NIGHT. KMD
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT THURSDAY FOR
WATERS FROM CAPE SHOALWATER WA TOFLORENCE OR FROM
10 TO 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 5 AM TO 5 PM PDT
THURSDAY FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD
OR FROM 10 TO 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
357 AM CDT THU MAY 17 2012
.DISCUSSION.../ISSUED AT 355 AM CDT/
WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS HAVE
DEVELOPED FROM JUST WEST OF SIOUX FALLS NORTHWARD ALONG THE
INTERSTATE 29 CORRIDOR OVERNIGHT UNDER THE INFLUENCE OF WARM
AIR/THETA E ADVECTION FACILITATED BY THE LOW LEVEL JET. ELEVATED CONVECTION
ALIGNS FAIRLY WELL WITH THE RUC 850-500MB OMEGA AND INSTABILITY
FIELDS...ALBEIT BOTH ARE RELATIVELY WEAK. THEREFORE EXPECT THE
ACTIVITY TO REMAIN ISOLATED IN NATURE. CONSIDERING WINDS ARE
HAULING AT 50-60 KTS AT TWO THOUSAND FEET...WILL NEED TO KEEP A
CLOSE EYE ON CELLS THAT DEVELOP AS THEY COULD BE WIND PRODUCERS.
BY DAYBREAK...ISOLATED ACTIVITY SHOULD BE MOSTLY CONFINED TO SW
MN...AND GRADUALLY WANE WITH LOSS OF THE LLJ INFLUENCE.
AFTER THE NOCTURNAL CONVECTION...THE NEXT ITEM OF FOCUS IS THE WIND
TODAY AND FRIDAY. 08Z SURFACE ANALYSIS ILLUSTRATED THE LOW
PRESSURE CENTER OVER WESTERN ND/SD. RELATIVELY TIGHT PRESSURE
GRADIENT AHEAD OF THIS FEATURE WILL SUPPORT WIND SPEEDS NEARING
ADVISORY CRITERIA /SUSTAINED 30 MPH/. NAM BUFKIT WINDS AT THE TOP OF
THE MIXED LAYER ARE CIRCA 40 KTS...BUT THERE WILL BE INCREASING
HIGH CLOUDS. WHILE ISOLATED LOCATIONS /ESPECIALLY HIGHER TERRAIN
AREAS/ COULD BRIEFLY HIT CRITERIA...DO NOT CURRENTLY EXPECTED
WIDESPREAD SUSTAINED SPEEDS AT 30 MPH. THEREFORE...WILL HOLD OFF
ON AN ADVISORY FOR NOW. TEMPERATURES WILL SOAR NEARLY 15 DEGREES
ABOVE NORMAL FOR THIS TIME OF YEAR...WITH HIGHS IN THE MID/UPPER
80S STILL APPEARING LIKELY.
LOWS TONIGHT WILL NOT DROP MUCH DUE TO THE PERSISTENT SOUTHERLY
FLOW AHEAD OF THE TROUGH. LOW TO MID 60S ARE EXPECTED TO BE COMMON
AT DAYBREAK FRIDAY. H85 TEMPERATURES CLIMB TO AROUND +22C ON
FRIDAY...WHICH SHOULD MAKE UPPER 80S AND LOWER 90S EASILY
ATTAINABLE.
THE COLD FRONT SHOULD REACH CENTRAL SD BY DAYBREAK SATURDAY...AND
TRACK EASTWARD ACROSS THE FORECAST AREA THROUGHOUT THE DAY. LIKELY
POPS SEEM WARRANTED ON SATURDAY AND SATURDAY NIGHT. INSTABILITY
AND SHEAR PARAMETERS ARE RATHER MARGINAL ON SATURDAY...SO SEVERE
THREAT STILL APPEARS TO BE FARTHER SOUTH. A FEW SHOWERS MAY LINGER
ON SUNDAY MAINLY EAST OF INTERSTATE 29...AND THEN RIDGING WILL
DEVELOP FOR THE START OF NEXT WEEK. AFTER TEMPERATURES ARE REDUCED
BACK INTO HE MID 60S TO LOWER 70S RANGE ON SUNDAY IN THE WAKE OF
THE FRONT...READINGS WILL GRADUALLY MODERATE TO VALUES IN THE
UPPER 70S AND LOWER 80S FOR TUESDAY.
SHOWER AND THUNDERSTORM CHANCES WILL RETURN FOR WEDNESDAY AND
THURSDAY...AS A RELATIVELY HEALTHY TROUGH TRACKS ACROSS THE NORTH
CENTRAL CONUS. HAVE INCLUDED 50-70 POPS FOR THIS SYSTEM.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED TO REMAIN THROUGH THURSDAY EVENING. COULD
SEE A BRIEF SHOWER OR THUNDERSTORM LATE TONIGHT INTO EARLY THURSDAY
ACROSS SOUTHWEST MINNESOTA...OTHERWISE WILL JUST HAVE SOME MID AND
HIGH CLOUDS WORK ACROSS THE AREA. A STRONG LOW LEVEL JET DEVELOPING
TONIGHT WILL PRODUCE LLWS AT THE TAF SITES THROUGH THE MORNING
HOURS. AFTER SUNRISE...THESE STRONGER WINDS WILL BEGIN TO MIX OUT
INCREASING THE SURFACE SPEEDS. SHOULD SEE SOUTHERLY WINDS GUSTING UP
TO 35 KTS DURING THE AFTERNOON MOST LOCATIONS. /CHENARD
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
315 AM CDT THU MAY 17 2012
.SHORT TERM...TONIGHT THROUGH SATURDAY
315 AM CDT THU MAY 17 2012
FORECAST CONCERNS INCLUDE SHRA CHANCES ACROSS THE NORTH TODAY AND
THEN INCREASING WARMTH THROUGH THE REMAINDER OF THE PERIOD.
LATEST WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW RIDGING OVER THE
IMMEDIATE FORECAST AREA WITH A WEAK MID-LEVEL TROUGH OVER THE
NORTHERN PLAINS. SURFACE ANALYSIS AT 3 AM HAS HIGH PRESSURE OVER THE
GREAT LAKES REGION WITH AN AREA OF LOW PRESSURE OVER THE NORTHERN
PLAINS. A WARM FRONT EXTENDED FROM THIS LOW EAST-SOUTHEASTWARD
ACROSS SOUTHERN MN INTO NORTHEAST IA. MOISTURE TRANSPORT/ISENTROPIC
LIFT AHEAD OF THE LOW AND OVER THE WARM FRONT WAS PRODUCING SOME
VERY HIGH-BASED SHRA/ISOLATED THUNDER ACROSS CENTRAL SD INTO FAR
SOUTHWEST MN.
17.00Z NCEP MODELS/17.21Z SREF IN GOOD AGREEMENT WITH OVERALL
SYNOPTIC SETUP THROUGH THE PERIOD.
FOR TODAY...LOW PRESSURE WILL STAY PUT ACROSS THE NORTHERN PLAINS AS
THE WARM FRONT LIFTS NORTH INTO CENTRAL MN/NORTHERN WI BY EARLY THIS
EVENING. AXIS OF LIGHT TO MODERATE 925-850MB MOISTURE TRANSPORT
STAYS NORTH OF THE AREA WITH BULK FAIRLY STRONG ISENTROPIC LIFT
FOLLOWING SUIT. EITHER WAY...LOWEST 700-600MB VERY DRY AS EVIDENCED
BY THE 17.00Z MPX SOUNDING AND NAM BUFKIT SOUNDINGS. MOST SHRA
ACTIVITY WILL BE FALLING OUT OF ACCAS CLOUD AT OR ABOVE 10-12KFT.
WOULD TAKE VIGOROUS CONVECTION FOR ANYTHING TO REACH THE GROUND. AS
SUCH...HAVE TRIMMED POPS FARTHER NORTH AND KEPT A SMALL CHANCE OF
SHRA/ISOLD THUNDER CONFINED NORTH OF HIGHWAY 10 IN WISCONSIN.
OTHERWISE...LOOK FOR INCREASING SOUTH WINDS TODAY WITH INCREASING
PRESSURE GRADIENT. WINDS ACROSS MUCH OF THE AREA SHOULD BE IN THE
15-25 MPH RANGE...BUT THE HIGHER/MORE WIND-PRONE AREAS OF SOUTHEAST
MN/NORTHEAST IA WILL LIKELY SEE WINDS MORE IN THE 20-25 MPH RANGE
WITH GUSTS AROUND 35 MPH. WITH WARM ADVECTION/RISING MOTIONS IN THE
BOUNDARY LAYER MITIGATING DOWNWARD TRANSFER OF STRONGER WINDS
ALOFT...FEEL WINDS WILL BE JUST SHY OF WIND ADVISORY. WILL HAVE TO
KEEP A CLOSE EYE ON THIS. TEMPERATURES ARE EXPECTED TO RESPOND TO
INCREASING SOUTHERLY FLOW WITH AFTERNOON HIGHS TOPPING OFF IN THE
UPPER 60S ACROSS NORTHERN WISCONSIN...TO THE MID-UPPER 70S
ELSEWHERE.
WARM FRONT PUSHES NORTH OF THE AREA THIS EVENING WITH A STRONG CAP
SETTING UP ACROSS THE AREA IN THE WARM SECTOR ON FRIDAY. WITH MOSTLY
SUNNY SKIES AND STRONG SOUTHERLY FLOW...TEMPERATURES SHOULD HAVE NO
PROBLEM REACHING INTO THE UPPER 70S TO MIDDLE 80S. DEW POINTS WILL
ALSO BE ON THE RISE INTO THE 50S FOR A SLIGHTLY MORE MUGGY FEEL
COMPARED TO THE LAST FEW DAYS.
COLD FRONT AND ASSOCIATED CONVECTION OVER THE NORTHERN PLAINS MAKES A MOVE
EASTWARD INTO MN/WESTERN IA ON SATURDAY WITH CAP HOLDING FIRM ACROSS
OUR FORECAST AREA. CONTINUED STRONG SOUTHERLY FLOW AND PARTLY TO
MOSTLY SUNNY SKIES SHOULD PUSH TEMPERATURES INTO THE MID-UPPER 80S.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
315 AM CDT THU MAY 17 2012
17.00Z ECMWF/GFS STILL SHOWING DIFFERENCE IN TIMING OF THE COLD
FRONTAL PASSAGE ACROSS THE AREA/ASSOCIATED SHRA/TS CHANCES IN THE SATURDAY
NIGHT/SUNDAY TIME FRAME. THE GFS REMAINS THE FASTER OF THE TWO
MODELS WITH PASSAGE AROUND 18Z WHEREAS THE ECMWF HOLDS OFF TIL
EVENING. WITH THIS UNCERTAINTY...WILL KEEP MODEL CONSENSUS APPROACH
GOING FOR NOW. WITH SLOWER TIMING...THERE STANDS A CHANCE FOR
STRONG/SEVERE THUNDERSTORMS WITH AMPLE CAPE/BULK SHEAR DEPICTED BY
THE ECMWF. HOPEFULLY THE MODELS WILL HAVE THIS RESOLVED A BIT BETTER
WITHIN THE NEXT FEW RUNS. MODELS THEN KEEP DIFFERENCES GOING THROUGH
THE REMAINDER OF THE PERIOD WITH THE GFS MAINTAINING A MORE
PROGRESSIVE WAVE PATTERN COMPARED TO THE ECMWF. ECMWF KEEPS
TROUGH/COOLER CYCLONIC FLOW AROUND THE AREA SUNDAY NIGHT THROUGH
TUESDAY FOR A SMALL CHANCE OF SHOWERS/ISOLATED THUNDER. THE GFS
BRINGS RIDGING IN FAIRLY QUICK FOR A DRIER SOLUTION. WILL KEEP MODEL
CONSENSUS GOING HERE AS WELL DUE TO THE UNCERTAINTY. UPPER/SURFACE
FLOW BECOMES SOUTHERLY ON WEDNESDAY WITH BOTH MODELS SHOWING A WEAK
EMBEDDED WAVE ALOFT. THE ECMWF SHOWS LIGHT QPF SIGNAL WITH THIS
FEATURE WHILE THE GFS REMAINS DRY. WILL INCLUDE A SLIGHT CHANCE OF
SHOWERS/THUNDER FOR NOW. OTHERWISE...LOOKS LIKE TEMPERATURES WILL
START OFF SOME 10 DEGREES ABOVE NORMAL ON SUNDAY IN THE MID 70-LOWER
80S...THEN NEAR NORMAL IN THE 70S MON/TUE/WED.
&&
.AVIATION...THROUGH 06Z FRIDAY
1151 PM CDT WED MAY 16 2012
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. WINDS WILL
CONTINUE TO SWING AROUND TO THE SOUTH OVERNIGHT AS THE SURFACE
HIGH SLIDES EASTWARD. MOISTURE TRANSPORT WILL NOSE INTO WESTERN
MINNESOTA BETWEEN 09Z-12Z TONIGHT WHICH WILL RESULT IN SOME
SHOWERS. THESE SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED TO
LIFT EAST-NORTHEAST AND REMAIN NORTH OF THE TAF SITES THROUGH
THURSDAY. 17.01Z HRRR DOES SHOW THE SHOWERS JUST SKIRTING
KRST...BUT WILL LEAVE ANY MENTION OUT OF THE FORECAST AT THIS
TIME...WITH ONLY A SCT-BKN BAND OF MID LEVEL CLOUDS. PRESSURE
GRADIENT WILL TIGHTEN LATE THIS MORNING...BETWEEN 15Z-18Z WITH
SOUTH WINDS INCREASING WITH SOME GUSTS TO BETWEEN 25 AND 35 KNOTS.
WINDS WILL SUBSIDE AFTER 00Z...BUT STILL REMAIN ABOVE 12 KNOTS AT
KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 AM CDT THU MAY 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1151 PM CDT WED MAY 16 2012
.SHORT TERM...TONIGHT THROUGH SATURDAY
237 PM CDT WED MAY 16 2012
MAIN FORECAST CONCERNS ARE ON BREEZY SOUTH WINDS ON THURSDAY ALONG
WITH SHOWER CHANCES ACROSS PORTIONS OF SOUTHEAST MINNESOTA INTO NORTH
CENTRAL WISCONSIN. FOCUS THEN TURNS TO TEMPERATURES FRIDAY INTO
SATURDAY.
AT 235 PM...SURFACE ANALYSIS PLACED A SURFACE RIDGE OF HIGH
PRESSURE CENTERED OVER THE UPPER MISSISSIPPI RIVER VALLEY. SKIES
WERE SUNNY ACROSS THE FORECAST AREA WITH AFTERNOON TEMPERATURES
RANGING FROM THE LOWER 60S ACROSS NORTH CENTRAL WISCONSIN TO
AROUND 70 ACROSS NORTHEAST IOWA.
THE HIGH WILL SLIDE EAST OF THE FORECAST AREA TONIGHT AS A TROUGH
DIGS INTO THE WESTERN CONUS. SURFACE LOW PRESSURE NEAR THE
MONTANA/SASKATCHEWAN BORDER WILL DEEPEN TONIGHT. A SURFACE TROUGH
IS EXPECTED TO EXTEND SOUTH THROUGH THE WESTERN DAKOTAS/NEBRASKA
PANHANDLE INTO EASTERN COLORADO. SOUTHERLY FLOW WILL INCREASE
ACROSS THE FORECAST AREA AHEAD OF THIS SYSTEM LATE TONIGHT INTO
EARLY THURSDAY MORNING AS A WARM FRONT PUSHES EAST ACROSS
MINNESOTA...AND IS EXPECTED TO BE POSITIONED ALONG THE MISSISSIPPI
RIVER AROUND 12Z. 850 MB MOISTURE TRANSPORT WILL BE FOCUSED INTO
NORTHERN MINNESOTA/NORTHWEST WISCONSIN THROUGH MUCH OF THE DAY ON
THURSDAY SO WOULD EXPECT THE BEST CHANCES FOR SHOWERS AND
THUNDERSTORMS ACROSS THESE AREAS. CANNOT RULE OUT A FEW SPRINKLES
OR LIGHT RAIN SHOWERS ACROSS NORTH CENTRAL INTO WEST CENTRAL
WISCONSIN LATE THURSDAY MORNING INTO THURSDAY AFTERNOON AS A WEAK
UPPER LEVEL SHORTWAVE MOVES EAST ACROSS CENTRAL MINNESOTA INTO
CENTRAL WISCONSIN. FORECAST SOUNDINGS SHOW A VERY DRY LAYER FROM
THE SURFACE THROUGH 600 MB. PRECIPITATION WILL HAVE A TOUGH TIME
MAKING IT THROUGH THIS LAYER. SHOULD SEE MAINLY A MID CLOUD DECK
OR POSSIBLY SOME ALTOCUMULUS CASTELLANAS/ACCAS/ THURSDAY MORNING
INTO THURSDAY AFTERNOON. WILL MAINTAIN SHOWER CHANCES ACROSS
PORTIONS OF SOUTHEAST MINNESOTA AND NORTH CENTRAL INTO WEST
CENTRAL WISCONSIN TO ACCOUNT FOR A FEW LIGHT SHOWERS OR SPRINKLES.
FORECAST SOUNDINGS ACROSS NORTH CENTRAL WISCONSIN INDICATING
AROUND 277 J/KG ELEVATED CAPE LIFTING FROM 600 THROUGH 300 MB...SO
WOULD EXPECT THIS INSTABILITY GO INTO ACCAS PRODUCTION. MUCH
WARMER AIR WILL MOVE INTO THE REGION BEHIND THE FRONT WITH 850 MB
TEMPERATURES WARMING TO AROUND 17 C BY LATE THURSDAY AFTERNOON.
HIGHS WILL CLIMB INTO THE UPPER 70S TO AROUND 80 ACROSS SOUTHEAST
MINNESOTA INTO NORTHEAST IOWA...WITH HIGHS RANGING FROM THE UPPER
60S ACROSS NORTH CENTRAL WISCONSIN TO THE UPPER 70S ACROSS FAR
SOUTHWEST WISCONSIN. IT WILL BE RATHER BREEZY ON
THURSDAY...ESPECIALLY ACROSS THE OPEN AREAS OF SOUTHEAST
MINNESOTA/NORTHEAST IOWA...AND THE BLUFF TOPS ACROSS WESTERN
WISCONSIN...WHERE SUSTAINED SOUTH WINDS OF 20 TO 25 MPH ARE
EXPECTED WITH GUSTS AROUND 44 MPH POSSIBLE DURING PEAK HEATING. IT
APPEARS THE WINDS WILL BE JUST SHY OF WIND ADVISORY CRITERIA SO
WILL HOLD OFF ON ISSUING AN ADVISORY. HOWEVER...WILL BE INCREASING
WIND SPEEDS ACROSS MUCH OF THE FORECAST AREA.
THE WARM FRONT WILL LIFT INTO UPPER MICHIGAN AND EXTREME NORTHERN
MINNESOTA THURSDAY EVENING. SHOWER AND THUNDERSTORM CHANCES WILL
SHIFT NORTH OF THE FORECAST AREA AS 850 MB MOISTURE TRANSPORT
REMAINS FOCUSES NORTH AND WEST OF THE AREA. IN ADDITION...UPPER
LEVEL RIDGING WILL BE BUILDING ACROSS THE FORECAST AREA...WITH NO
APPRECIABLE UPPER LEVEL FORCING TO GENERATE PRECIPITATION. UNDER
MOSTLY CLEAR SKIES...SOUTHERLY WINDS WILL KEEP TEMPERATURES ON THE
MILD SIDE THURSDAY NIGHT WITH LOWS RANGING FROM THE LOWER 60S ACROSS
SOUTHEAST MINNESOTA INTO NORTHEAST IOWA...TO THE MID 50S ACROSS
CENTRAL INTO FAR SOUTHWEST WISCONSIN.
A WARM DAY IS ON TAP FOR THE REGION ON FRIDAY WITH HIGHS RANGING
FROM THE LOWER 80S ACROSS NORTH CENTRAL WISCONSIN TO THE UPPER 80S
ACROSS NORTHEAST IOWA. IN ADDITION...HIGHER DEWPOINTS WILL MAKE A
RETURN TO THE AREA WITH DEWPOINTS CLIMBING INTO THE UPPER 50S TO
LOWER 60S. THE COMBINATION OF THESE TEMPERATURES AND DEWPOINTS WILL
MAKE IT FEEL A LITTLE ON THE MUGGY SIDE COMPARED TO THE DRY AIR WE
EXPERIENCED THIS PAST WEEK. ANOTHER BREEZY DAY IS EXPECTED WITH
SOUTH WINDS IN THE 15 TO 20 MPH RANGE...POSSIBLY GUSTING TO AROUND
30 MPH AT TIMES IN THE OPEN AREAS OF SOUTHEAST MINNESOTA AND
NORTHEAST IOWA. THE TROUGH OVER THE WESTERN US WILL MOVE EAST INTO
THE PLAINS FRIDAY NIGHT INTO SATURDAY WITH THE SURFACE LOW LIFTING
NORTH OUT OF THE DAKOTAS INTO WESTERN ONTARIO. A COLD FRONT WILL
DRIFT INTO WESTERN MINNESOTA BY LATE SATURDAY AFTERNOON WITH
SHOWERS/THUNDERSTORMS EXPECTED AHEAD OF THE FRONT. ANOTHER WARM
DAY IS EXPECTED ACROSS THE FORECAST AREA WITH HIGHS CLIMBING INTO
THE MID TO UPPER 80S UNDER PARTLY SUNNY SKIES. IN
ADDITION...DEWPOINTS WILL REMAIN IN THE UPPER 50S TO LOWER 60S
MAKING IT FEEL A LITTLE ON THE MUGGY SIDE. THE COLD FRONT IS
EXPECTED TO REMAIN WEST OF THE FORECAST AREA ON SATURDAY.
AFTERNOON MUCAPE VALUES INCREASING INTO THE 1500 TO 2000 J/KG
RANGE. FORECAST SOUNDINGS SHOW A WEAK CAP IN PLACE BY SATURDAY
AFTERNOON. NOT EXPECTING TO SEE MUCH DEVELOPMENT WITH VIRTUALLY NO
FORCING TO HELP SPARK SHOWERS/THUNDERSTORM UNTIL THE COLD FRONT
MOVES IN. EVEN IF STORMS COULD DEVELOP...SHEAR IS VERY WEAK SO
WOULD NOT EXPECT TO SEE SEVERE THUNDERSTORMS DURING THE DAY ON
SATURDAY.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
237 PM CDT WED MAY 16 2012
16.12 FORECAST MODELS SHOWING SOME SLIGHT DIFFERENCES IN TIMING OF
THE COLD FRONT MOVING THROUGH THE FORECAST AREA SATURDAY NIGHT
THROUGH SUNDAY. THE GFS/GEM ARE THE FASTER SOLUTIONS...BRINGING THE
FRONT THROUGH THE FORECAST AREA LATE SATURDAY NIGHT INTO EARLY
SUNDAY AFTERNOON. THE ECMWF IS A LITTLE SLOWER...BRINGING THE FRONT
THROUGH THE AREA LATE SUNDAY AFTERNOON INTO SUNDAY EVENING. 0-6 KM
BULK SHEAR VALUES INCREASE ACROSS THE AREA SATURDAY NIGHT THROUGH
SUNDAY INTO THE 30 TO 35 KT RANGE. DEPENDING ON THE TIMING OF THE
FRONT STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE BUT DO NOT APPEAR
LIKELY AT THIS TIME. GIVEN THE UNCERTAINTY ON EXACTLY WHEN THE FRONT
WILL MOVE THROUGH...ITS DIFFICULT TO PIN DOWN EXACT SEVERE WEATHER
THREATS AT THIS TIME IF IT OCCURS. WEAK HIGH PRESSURE WILL BUILD
INTO THE REGION BEHIND THE FRONT MONDAY NIGHT INTO TUESDAY. LOOK
FOR HIGHS TO FALL BACK INTO THE 70S ON MONDAY. THE HIGH LOOKS TO
SLIDE EAST OF THE AREA TUESDAY NIGHT INTO WEDNESDAY AS A TROUGH
MOVES ACROSS THE PACIFIC NORTHWEST AND PUSHES EAST THROUGH THE
DAKOTAS ON TUESDAY NIGHT INTO WEDNESDAY. SOUTHERLY FLOW WILL
INCREASE AHEAD OF THIS SYSTEM PUMPING MOIST UNSTABLE AIR BACK INTO
THE REGION. FLOW ALOFT LOOKS TO TURN SOUTHWEST ON WEDNESDAY AS THE
TROUGH PUSHES EAST INTO THE UPPER MISSISSIPPI RIVER VALLEY.
EMBEDDED SHORTWAVE COULD TRIGGER SHOWERS AND THUNDERSTORMS ACROSS
THE REGION WEDNESDAY INTO WEDNESDAY NIGHT. MODELS ARE HINTING AT
AN ACTIVE PATTERN TO END THE WEEK BUT WILL HAVE TO TAKE A CLOSER
LOOK AT THIS WITH LATER MODEL RUNS.
&&
.AVIATION...THROUGH 06Z FRIDAY
1151 PM CDT WED MAY 16 2012
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. WINDS WILL
CONTINUE TO SWING AROUND TO THE SOUTH OVERNIGHT AS THE SURFACE
HIGH SLIDES EASTWARD. MOISTURE TRANSPORT WILL NOSE INTO WESTERN
MINNESOTA BETWEEN 09Z-12Z TONIGHT WHICH WILL RESULT IN SOME
SHOWERS. THESE SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED TO
LIFT EAST-NORTHEAST AND REMAIN NORTH OF THE TAF SITES THROUGH
THURSDAY. 17.01Z HRRR DOES SHOW THE SHOWERS JUST SKIRTING
KRST...BUT WILL LEAVE ANY MENTION OUT OF THE FORECAST AT THIS
TIME...WITH ONLY A SCT-BKN BAND OF MID LEVEL CLOUDS. PRESSURE
GRADIENT WILL TIGHTEN LATE THIS MORNING...BETWEEN 15Z-18Z WITH
SOUTH WINDS INCREASING WITH SOME GUSTS TO BETWEEN 25 AND 35 KNOTS.
WINDS WILL SUBSIDE AFTER 00Z...BUT STILL REMAIN ABOVE 12 KNOTS AT
KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
237 PM CDT WED MAY 16 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
940 AM EDT THU MAY 17 2012
.DISCUSSION...
CURRENTLY...WEAK SURFACE TROUGH EXTENDS NNE FROM THE YUCATAN TO
APALACHEE BAY AND INTO SE GA WITH BROAD MID/UPPER TROUGH COVERING
THE NRN GOMEX. RUC INIT PANELS 80-90KT H25 JET CORE PUNCHING OVER
THE TOP OF THE STATE WITH BEST DIVG HAVING SHIFTED EAST..AND NOW
EXTENDS FROM SOUTH FL NEWD ACROSS THE BAHAMAS AND INTO THE ATLC.
VISIBLE SAT IMAGERY SHOWS EXTENSIVE MULTI-LAYERED CLOUDS COVERING
THE CWA FROM OSCEOLA/BREVARD SWD...WITH SOME OCNL BREAKS DEVELOPING
TO THE N/W. SOUNDER/RAOB DATA SHOW PWATS RANGING FROM 1.5" ACROSS
THE NORTH TO 1.8" OR SO NEAR LAKE OKEE...WITH H50 TEMPS -10C/-11C
AND EVEN COOLER (-14C @JAX) OVER NORTH FL.
TODAY...LIGHT S-SW FLOW EXPECTED AGAIN TODAY ON EAST SIDE OF WEAK
SURFACE TROUGH. AXIS OF THE MID LEVEL TROUGH WILL SLIDE EWD WITH
INCREASING MID LEVEL PVA COUNTERACTING THE EWD SHIFT OF JET FORCED
ASCENT AWAY FROM THE PENINSULA TO SOME DEGREE. EXPECT TODAY TO BE
MORE CONVECTIVELY ACTIVE OVERALL...WITH EARLIER ONSET COMPARED TO
WED. LACK OF WIDESPREAD OVC CLOUD DECK SHOULD ALLOW BETTER SURFACE
HEATING AND THUS GREATER INSTABILITY AND STRONGER MORE NUMEROUS
AFTERNOON STORMS...WHILE CONTINUATION OF SOME COMPONENT OF FORCED
ASCENT WOULD FAVOR ACTIVITY CONTINUING PAST SUNSET FOR AT LEAST A
FEW HOURS.
CURRENT FCST HAS A GOOD HANDLE ON SITUATION WITH SLIGHTLY HIGHER POP
DISTRIBUTION SOUTH.
&&
.AVIATION...MULTILAYERED BROKEN CLOUDS/SHRA SOUTH/EAST OF KTIX-KAGR
WITH SOME IFR STRATUS OVER NORTH FL....SWD TO ABOUT KLEE. ISOLATED
SHRA/TS STARTING AROUND 16Z. ACTIVITY INCREASING IN COVERAGE AND
BECOMING NMRS AFTER 18Z WITH LOCAL IFR CIGS/VSBYS IN STORMS. SOME
STORMS MAY PRODUCE WIND GUSTS OVER 35KT THIS AFTERNOON AND EVENING
THROUGH ABOUT 02Z-03Z.
&&
.MARINE...
TODAY-TONIGHT...PRIMARY MARINE CONCERN CONTINUES TO BE OFFSHORE
MOVING THUNDERSTORMS THIS AFTERNOON/EVENING. WINDS REMAIN 10KTS OR
LESS OUT OF THE S-SW WITH SEAS 1-2FT NEARSHORE AND 2-3FT OFFSHORE
IN A LONG PERIOD SWELL.
&&
.FIRE WEATHER...
NO RH/WIND CONCERNS TODAY. NUMEROUS AFTERNOON/EVENING SHRAS/TS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...CRISTALDI
LONG TERM/IMPACT WX...WIMMER
AREA FORECAST DISCUSSION
NWS MIAMI FL
908 AM EDT THU MAY 17 2012
.UPDATE...
SOME CHANGES WERE MADE TO THE SHORT TERM FORECAST. THE SHORT TERM
WIND FORECAST IS PROBLEMATIC IN THAT THE CONVECTION THAT PASSED
THROUGH THE REGION EARLIER THIS MORNING DISRUPTED THE SYNOPTIC
FLOW AND THE WINDS ARE CURRENTLY SOMEWHAT VARIABLE. BUT THE
CONSENSUS OF THE LATEST GUIDANCE SUGGESTS THAT A SOUTH TO
SOUTHWESTERLY FLOW IS LIKELY TO BECOME RE-ESTABLISHED ACROSS THE
REGION LATER THIS MORNING OR THIS AFTERNOON. ALSO UPDATED THE
MARINE FORECAST TO REFLECT THE SHOWER AND THUNDERSTORM ACTIVITY
ACROSS THE ATLANTIC WATERS FROM EARLIER THIS MORNING BUT THE
THUNDERSTORM ACTIVITY IS CURRENTLY SUBSIDING. FOR THE FORECAST FOR
THE REMAINDER OF THE DAY...WILL LEAVE CURRENT FORECAST FOR
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. ALTHOUGH ACTIVITY
HAS SUBSIDED THIS MORNING...SEVERAL SYNOPTIC FACTORS SUGGEST THAT
CONVECTION COULD START LATER THIS MORNING OR INTO THE AFTERNOON.
THE FACTORS INCLUDE AN UPPER LEVEL JET PASSING THROUGH THE
REGION AND LOW LEVEL MASS AND MOISTURE CONVERGENCE CONTINUING
ACROSS THE REGION. PLUS RECENT SATELLITE IMAGERY INDICATES SOME
AREAS OF CLEARING ACROSS THE PENINSULA WHICH MAY ALLOW SUFFICIENT
DAY TIME HEATING TO INITIATE CONVECTION. BUT BEST CHANCES OF
CONVECTION IS PROBABLY STILL THE EASTERN HALF OF THE PENINSULA AND
THE ADJACENT ATLANTIC WATERS.
60
&&
.PREV DISCUSSION... /ISSUED 741 AM EDT THU MAY 17 2012/
AVIATION...VFR WILL PREVAIL WITH EXTENSIVE MID/HIGH LEVEL
CLOUDINESS BEHIND DEPARTING CONVECTION NOW OVER THE ATLANTIC.
IT WILL TAKE TIME FOR THE AIRMASS TO RECOVER, AND HRRR ACTUALLY
DOES NOT SHOW CONVECTION ON THE EAST COAST UNTIL NEAR KPBI BY 4
PM. IT DOES DEVELOP A BROKEN LINE OF CONVECTION LATE THIS
AFTERNOON FROM JUST NORTH OF LAKE OKEECHOBEE TO ACROSS LEE COUNTY
BEFORE MOVING SLOWLY SE INTO THE AREA. THIS LATE START TO
CONVECTION LOOKS REASONABLE, SO HAVE TEMPO TSRA/MVFR FROM 19-23Z
FOR ALL EAST COAST TERMINALS AND VCTS FOR KAPF. MAY NEED TO ADD
TEMPO THERE SHOULD A BROKEN LINE OF CONVECTION DEVELOP SO WILL
MONITOR TRENDS. ANY STORM LATE THIS AFTERNOON/EVENING WILL BE
CAPABLE OF PRODUCING BRIEF IFR CONDITIONS ALONG WITH STRONG WIND
GUSTS. /GREGORIA
PREV DISCUSSION... /ISSUED 330 AM EDT THU MAY 17 2012/
DISCUSSION...S FLA HAS BEEN UNDER THE INFLUENCE OF THE UPPER TROUGH
OVER THE E U.S. COAST THAT CURRENTLY EXTENDS SW ACROSS THE SE U.S.
INTO THE GULF OF MEX. TODAY AND INTO THE WEEKEND...A CLOSED LOW WILL
DEVELOP OVER THE SE U.S./ADJACENT ATLC AND WILL PERSIST THROUGH THE
WEEKEND INTO EARLY NEXT WEEK DUE TO THE DEVELOPMENT OF A REX BLOCK
AS A STRONG UPPER RIDGE EXTENDS NW OVER NEW ENGLAND FROM THE ALTC
HIGH. THIS STOPS THE MOVEMENT OF THE UPPER LOW. BY MIDWEEK NEXT
WEEK...LONG RANGE MODELS DIFFER SOME ON THE SCENARIO...BUT A DEEP
UPPER TROUGH OVER THE WESTERN U.S. MOVES E WHICH PULLS THE CLOSED
LOW N AND ABSORBING THE FORMER SYSTEM. THE GFS INDICATES MULTIPLE
SMALL UPPER TROUGHS THAT MAY CROSS FLA WITH THE ECMWF INDICATING A
WESTERLY FLOW ALOFT WHICH MAY BRING MINIMAL SHORT WAVES ACROSS THE
AREA.
SHORT TERM...(TODAY-SATURDAY)...TODAY COULD BE MORE ACTIVE THAN
THURSDAY. A 500 MB 40 KT WIND AXIS MOVES NE ACROSS S CENTRAL FLA
WITH S FLA IN THE RFQ WITH SOME SPEED DIVERGENCE. WITH E/W COAST SEA
BREEZES DEVELOPING ALONG WITH THE AMPLE POSSIBILITY OF MORE
INSOLATION...VERY HIGH POPS WITH NUMEROUS TO WIDESPREAD
SHOWERS/THUNDERSTORMS POSSIBLE INTERIOR AND E. THERE WILL BE MAINLY
EVENING SHOWERS/THUNDERSTORMS E THIS EVENING BUT WITH THE MOIST
SW FLOW...ACTIVITY WILL STILL MOVE FROM THE GULF ACROSS THE
PENINSULA. POPS DIFFER BETWEEN MODELS FRIDAY BUT THE SURFACE
TROUGH...WHICH IS A REFLECTION OF THE UPPER TROUGH TO THE
NW...REMAINS NW OF S FLA AND S FLA REMAINS UNDER THE VERY MOIST
REGIME LIKE TODAY. THUS...WILL GO ABOVE MAV POPS. FRIDAY NIGHT A
SW FLOW ALOFT REMAINS BUT WITH THE SURFACE TROUGH DRAGGING
THROUGH...POPS LOWER. ON SATURDAY...SOME DRYING OCCURS.
EXTENDED PERIOD...(SUNDAY-WEDNESDAY)...AS MENTIONED ABOVE...THE
LONG RANGE PATTERN VARIES PER MODEL AND SOME DECREASE IN CONFIDENCE
OF THE POSSIBILITIES EXISTS. WITH THE SW UPPER FLOW PROJECTED TO
PERSIST...SOME RIPPLES MOVING THROUGH AND WITH VARIATION ON MODEL
PRECIPITATION FORECAST...WILL FOLLOW MEX GUIDANCE BUT EXPECT MORE
ACTIVITY IN THE INTERIOR AND NE THROUGH THE PERIOD AS THE LOW LEVEL
EASTERLY FLOW EXPECTED SHUNTING PRECIPITATION A BIT TO THE N.
MARINE...
WINDS GENERALLY LESS THAN 10 KNOTS WITH AND SEAS 3 FEET OR LESS. THE
MAIN PROBLEMS WILL BE THE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS.
FIRE WEATHER...
AMPLE RAIN AND HIGH HUMIDITY EQUAL NO PROBLEMS TODAY AND THROUGH THE
WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 72 86 72 / 70 50 50 40
FORT LAUDERDALE 85 74 87 75 / 70 50 50 40
MIAMI 85 73 88 74 / 70 50 50 40
NAPLES 83 71 85 70 / 50 50 50 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...60/BD
AVIATION/RADAR...57/DG
AREA FORECAST DISCUSSION
NWS MIAMI FL
741 AM EDT THU MAY 17 2012
.AVIATION...VFR WILL PREVAIL WITH EXTENSIVE MID/HIGH LEVEL
CLOUDINESS BEHIND DEPARTING CONVECTION NOW OVER THE ATLANTIC.
IT WILL TAKE TIME FOR THE AIRMASS TO RECOVER, AND HRRR ACTUALLY
DOES NOT SHOW CONVECTION ON THE EAST COAST UNTIL NEAR KPBI BY 4
PM. IT DOES DEVELOP A BROKEN LINE OF CONVECTION LATE THIS
AFTERNOON FROM JUST NORTH OF LAKE OKEECHOBEE TO ACROSS LEE COUNTY
BEFORE MOVING SLOWLY SE INTO THE AREA. THIS LATE START TO
CONVECTION LOOKS REASONABLE, SO HAVE TEMPO TSRA/MVFR FROM 19-23Z
FOR ALL EAST COAST TERMINALS AND VCTS FOR KAPF. MAY NEED TO ADD
TEMPO THERE SHOULD A BROKEN LINE OF CONVECTION DEVELOP SO WILL
MONITOR TRENDS. ANY STORM LATE THIS AFTERNOON/EVENING WILL BE
CAPABLE OF PRODUCING BRIEF IFR CONDITIONS ALONG WITH STRONG WIND
GUSTS. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 330 AM EDT THU MAY 17 2012/
DISCUSSION...S FLA HAS BEEN UNDER THE INFLUENCE OF THE UPPER TROUGH
OVER THE E U.S. COAST THAT CURRENTLY EXTENDS SW ACROSS THE SE U.S.
INTO THE GULF OF MEX. TODAY AND INTO THE WEEKEND...A CLOSED LOW WILL
DEVELOP OVER THE SE U.S./ADJACENT ATLC AND WILL PERSIST THROUGH THE
WEEKEND INTO EARLY NEXT WEEK DUE TO THE DEVELOPMENT OF A REX BLOCK
AS A STRONG UPPER RIDGE EXTENDS NW OVER NEW ENGLAND FROM THE ALTC
HIGH. THIS STOPS THE MOVEMENT OF THE UPPER LOW. BY MIDWEEK NEXT
WEEK...LONG RANGE MODELS DIFFER SOME ON THE SCENARIO...BUT A DEEP
UPPER TROUGH OVER THE WESTERN U.S. MOVES E WHICH PULLS THE CLOSED
LOW N AND ABSORBING THE FORMER SYSTEM. THE GFS INDICATES MULTIPLE
SMALL UPPER TROUGHS THAT MAY CROSS FLA WITH THE ECMWF INDICATING A
WESTERLY FLOW ALOFT WHICH MAY BRING MINIMAL SHORT WAVES ACROSS THE
AREA.
SHORT TERM...(TODAY-SATURDAY)...TODAY COULD BE MORE ACTIVE THAN
THURSDAY. A 500 MB 40 KT WIND AXIS MOVES NE ACROSS S CENTRAL FLA
WITH S FLA IN THE RFQ WITH SOME SPEED DIVERGENCE. WITH E/W COAST SEA
BREEZES DEVELOPING ALONG WITH THE AMPLE POSSIBILITY OF MORE
INSOLATION...VERY HIGH POPS WITH NUMEROUS TO WIDESPREAD
SHOWERS/THUNDERSTORMS POSSIBLE INTERIOR AND E. THERE WILL BE MAINLY
EVENING SHOWERS/THUNDERSTORMS E THIS EVENING BUT WITH THE MOIST
SW FLOW...ACTIVITY WILL STILL MOVE FROM THE GULF ACROSS THE
PENINSULA. POPS DIFFER BETWEEN MODELS FRIDAY BUT THE SURFACE
TROUGH...WHICH IS A REFLECTION OF THE UPPER TROUGH TO THE
NW...REMAINS NW OF S FLA AND S FLA REMAINS UNDER THE VERY MOIST
REGIME LIKE TODAY. THUS...WILL GO ABOVE MAV POPS. FRIDAY NIGHT A
SW FLOW ALOFT REMAINS BUT WITH THE SURFACE TROUGH DRAGGING
THROUGH...POPS LOWER. ON SATURDAY...SOME DRYING OCCURS.
EXTENDED PERIOD...(SUNDAY-WEDNESDAY)...AS MENTIONED ABOVE...THE
LONG RANGE PATTERN VARIES PER MODEL AND SOME DECREASE IN CONFIDENCE
OF THE POSSIBILITIES EXISTS. WITH THE SW UPPER FLOW PROJECTED TO
PERSIST...SOME RIPPLES MOVING THROUGH AND WITH VARIATION ON MODEL
PRECIPITATION FORECAST...WILL FOLLOW MEX GUIDANCE BUT EXPECT MORE
ACTIVITY IN THE INTERIOR AND NE THROUGH THE PERIOD AS THE LOW LEVEL
EASTERLY FLOW EXPECTED SHUNTING PRECIPITATION A BIT TO THE N.
MARINE...
WINDS GENERALLY LESS THAN 10 KNOTS WITH AND SEAS 3 FEET OR LESS. THE
MAIN PROBLEMS WILL BE THE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS.
FIRE WEATHER...
AMPLE RAIN AND HIGH HUMIDITY EQUAL NO PROBLEMS TODAY AND THROUGH THE
WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 72 86 72 / 70 50 50 40
FORT LAUDERDALE 85 74 87 75 / 70 50 50 40
MIAMI 85 73 88 74 / 70 50 50 40
NAPLES 83 71 85 70 / 50 50 50 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...15/JR
AVIATION/RADAR...17/ERA
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1043 AM EDT THU MAY 17 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 140 AM EDT THU MAY 17 2012
HIGH PRESSURE OVER THE APPALACHIANS WILL DOMINATE INDIANA WEATHER
THROUGH THE WEEKEND. A COLD FRONT IS FORECAST TO APPROACH AND THEN
CROSS THE HOOSIER STATE MONDAY AND TUESDAY. AFTER THAT...HIGH
PRESSURE SHOULD RETURN FROM THE WEST.
&&
.NEAR TERM /TODAY/...
ISSUED AT 1010 AM EDT THU MAY 17 2012
NO SIGNIFICANT CHANGES NEEDED AT THIS TIME. MADE SOME CHANGES TO
THE DEWPOINT GRIDS TO LOWER THEM ACROSS THE SOUTH AS SOME DRY
ADVECTION OCCURRING. PREVIOUS FORECAST HAD LEANED TOWARDS WARMER MAV
AND THIS SEEMS REASONABLE GIVEN THERE WILL BE FULL SUNSHINE TODAY.
THE RUC MODEL SOUNDINGS WERE A LITTLE WARMER WHILE THE 00Z NAM
SOUNDINGS WERE A LITTLE COOLER. MADE A FEW MINOR TWEAKS TO
TEMPERATURE GRIDS MAINLY TO LOWER THEM A DEGREE IN THE EAST.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 140 AM EDT THU MAY 17 2012
ALL MODELS CLOSE..BUT NAM IS A MINOR OUTLIER COMPARED TO NEARLY
IDENTICAL SREF AND GFS. WITH GFS LOOKING A LITTLE BETTER WILL USE
THAT AS UNDERLYING MODEL.
THIS DOES NOT MAKE MUCH DIFFERENCE SINCE ALL MODELS CALLING FOR
MOSTLY CLEAR THROUGH SATURDAY AND MET AND MAV ARE CLOSE ON TEMPS.
USING MAV WHEN ANY DIFFERENCE FROM MET BECAUSE FAVOR GFS AND MAV
HAD LONGER DEVELOPMENT CYCLE.
PRECIP NOT ABSOLUTELY OUT OF QUESTION SATURDAY NIGHT IN WARM
ADVECTION. HOWEVER POSSIBILITY IS MARGINAL AT MOST AND WILL
CONTINUE WITH DRY FORECAST FOR NOW.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 220 AM EDT THU MAY 17 2012
MAIN FOCUS ON THE LONG TERM WILL BE TIMING OF THUNDERSTORM CHANCES
BACK TO CENTRAL INDIANA ALONG WITH TEMPERATURES AS A COLD FRONT
APPROACHES LATE IN THE WEEKEND AND EARLY NEXT WEEK.
THE 00Z GEM IS NOW LEANING SLOWER WITH A COLD FRONT LATE THIS
WEEKEND AND EARLY NEXT WEEK PER THE 12Z ECMWF AND EURO TRENDS AND AS
OPPOSED TO THE FASTER 00Z GFS AND GFS TRENDS. THIS WOULD FAVOR
HOLDING OFF POPS INTIL SUNDAY NIGHT ACROSS THE WEST AND ACROSS ALL
OF CENTRAL INDIANA BY MONDAY. THE FRONT AND ASSOCIATED CONVECTION
ARE EXPECTED TO RESULT IN NOT AS WARM TEMPERATURES BY MONDAY WITH
REASONABLE CR INIT HIGHS ONLY IN THE 70S BY TUESDAY WITH 80S SUNDAY
AND MONDAY AHEAD OF THE FRONT. INSTABILITY PROGS SUGGEST PLENTY OF
INSTABILITY THROUGH THE PERIOD FOR THUNDERSTORM MENTION.
&&
.AVIATION /DISCUSSION FOR THE 17/1500Z TAF UPDATE/...
ISSUED AT 1041 AM EDT THU MAY 17 2012
UPDATE...
NO CHANGES.
PREVIOUS DISCUSSION...
VFR CONDITIONS EXPECTED TODAY WITH JUST SOME HIGH CLOUDS LATE. CU
PROGS WERE NOT INDICATING ANY DIURNAL CU. WOULD NOT RULE OUT FOG
OVERNIGHT TONIGHT WITH MODELS AGREEING ON DEW POINTS INCREASING TO
THE UPPER 40S AS HIGH PRESSURE SHIFTS TO THE EASTERN GREAT LAKES
ALLOW FOR LIGHT SOUTHEAST ATLANTIC FETCH OF MOISTURE. HOWEVER...MOS
IS NOT INDICATING ANY YET...SO WILL HOLD OFF FOR NOW DESPITE EAST
WINDS NEAR 10 KNOTS TODAY BECOMING LIGHT TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JH
LONG TERM....MK
AVIATION...MK/TDUD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1010 AM EDT FRI MAY 17 2012
.UPDATE...
NEAR TERM FR THE REST OF TODAY HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 140 AM EDT THU MAY 17 2012
HIGH PRESSURE OVER THE APPALACHIANS WILL DOMINATE INDIANA WEATHER
THROUGH THE WEEKEND. A COLD FRONT IS FORECAST TO APPROACH AND THEN
CROSS THE HOOSIER STATE MONDAY AND TUESDAY. AFTER THAT...HIGH
PRESSURE SHOULD RETURN FROM THE WEST.
&&
.NEAR TERM /TODAY/...
ISSUED AT 1010 AM EDT THU MAY 17 2012
NO SIGNIFICANT CHANGES NEEDED AT THIS TIME. MADE SOME CHANGES TO
THE DEWPOINT GRIDS TO LOWER THEM ACROSS THE SOUTH AS SOME DRY
ADVECTION OCCURRING. PREVIOUS FORECAST HAD LEANED TOWARDS WARMER MAV
AND THIS SEEMS REASONABLE GIVEN THERE WILL BE FULL SUNSHINE TODAY.
THE RUC MODEL SOUNDINGS WERE A LITTLE WARMER WHILE THE 00Z NAM
SOUNDINGS WERE A LITTLE COOLER. MADE A FEW MINOR TWEAKS TO
TEMPERATURE GRIDS MAINLY TO LOWER THEM A DEGREE IN THE EAST.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 140 AM EDT THU MAY 17 2012
ALL MODELS CLOSE..BUT NAM IS A MINOR OUTLIER COMPARED TO NEARLY
IDENTICAL SREF AND GFS. WITH GFS LOOKING A LITTLE BETTER WILL USE
THAT AS UNDERLYING MODEL.
THIS DOES NOT MAKE MUCH DIFFERENCE SINCE ALL MODELS CALLING FOR
MOSTLY CLEAR THROUGH SATURDAY AND MET AND MAV ARE CLOSE ON TEMPS.
USING MAV WHEN ANY DIFFERENCE FROM MET BECAUSE FAVOR GFS AND MAV
HAD LONGER DEVELOPMENT CYCLE.
PRECIP NOT ABSOLUTELY OUT OF QUESTION SATURDAY NIGHT IN WARM
ADVECTION. HOWEVER POSSIBILITY IS MARGINAL AT MOST AND WILL
CONTINUE WITH DRY FORECAST FOR NOW.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 220 AM EDT THU MAY 17 2012
MAIN FOCUS ON THE LONG TERM WILL BE TIMING OF THUNDERSTORM CHANCES
BACK TO CENTRAL INDIANA ALONG WITH TEMPERATURES AS A COLD FRONT
APPROACHES LATE IN THE WEEKEND AND EARLY NEXT WEEK.
THE 00Z GEM IS NOW LEANING SLOWER WITH A COLD FRONT LATE THIS
WEEKEND AND EARLY NEXT WEEK PER THE 12Z ECMWF AND EURO TRENDS AND AS
OPPOSED TO THE FASTER 00Z GFS AND GFS TRENDS. THIS WOULD FAVOR
HOLDING OFF POPS INTIL SUNDAY NIGHT ACROSS THE WEST AND ACROSS ALL
OF CENTRAL INDIANA BY MONDAY. THE FRONT AND ASSOCIATED CONVECTION
ARE EXPECTED TO RESULT IN NOT AS WARM TEMPERATURES BY MONDAY WITH
REASONABLE CR INIT HIGHS ONLY IN THE 70S BY TUESDAY WITH 80S SUNDAY
AND MONDAY AHEAD OF THE FRONT. INSTABILITY PROGS SUGGEST PLENTY OF
INSTABILITY THROUGH THE PERIOD FOR THUNDERSTORM MENTION.
&&
.AVIATION /DISCUSSION FOR 171200Z TAF ISSUANCE/...
ISSUED AT 617 AM EDT WED MAY 17 2012
VFR CONDITIONS EXPECTED TODAY WITH JUST SOME HIGH CLOUDS LATE. CU
PROGS WERE NOT INDICATING ANY DIURNAL CU. WOULD NOT RULE OUT FOG
OVERNIGHT TONIGHT WITH MODELS AGREEING ON DEW POINTS INCREASING TO
THE UPPER 40S AS HIGH PRESSURE SHIFTS TO THE EASTERN GREAT LAKES
ALLOW FOR LIGHT SOUTHEAST ATLANTIC FETCH OF MOISTURE. HOWEVER...MOS
IS NOT INDICATING ANY YET...SO WILL HOLD OFF FOR NOW DESPITE EAST
WINDS NEAR 10 KNOTS TODAY BECOMING LIGHT TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JH
LONG TERM....MK
AVIATION...MK
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1135 AM EDT THU MAY 17 2012
.Forecast Update...
Issued at 1135 AM EDT May 17 2012
The clouds that were moving in from the northeast earlier this
morning dissipated right on schedule, leaving us with mostly sunny
skies by 15Z.
Surface dew points have been increasing and pooling over southern
Kentucky this morning. HRRR has been trending much more bullish
with convection in the south this afternoon. After coordination
with neighboring offices, and considering the afternoon development
we saw over the past two days, have decided to go ahead and throw in
a SLGT CHC of showers/storms during peak heating this afternoon in
the south. Will restrict PoPs to the south of where the 1000 foot
overcast was earlier.
Issued at 830 AM EDT May 17 2012
This update primarily dealt with a 1000 foot overcast that developed
over the southern Blue Grass. It appears that the clouds should mix
out by 15Z, but in the meantime we have significantly increased
cloudcover in and near that patch of clouds.
A shower managed to pop up over Hart County between 11Z and 12Z but
it has since fallen apart. Munfordville web cam did show some
elevated instability revealed in the cumuliform cloud structures
overhead...as also seen on visible satellite channel. A rogue
shower will still be possible in southeastern sections of the LMK
CWA near a diffuse cold front, but coverage should remain minimal.
Went ahead an increased PoPs to a silent 13% southeast of a BWG-LEX
line.
.Short Term (Today through Friday)...
Issued at 308 AM EDT May 17 2012
The weak frontal boundary that brought scattered showers/storms to
the region last evening has stalled across south-central KY early
this morning. South of this boundary, winds are calm and dewpoints
are still in the upper 50s. With this moist air in place, light
ground fog will again be possible towards dawn, mainly over lakes or
low-lying areas or river valleys. North of the boundary however,
winds are out of the northeast with dewpoints dropping into the
upper 40s. Even further north, a secondary dewpoint boundary across
southern IN has upper 30 dewpoints behind it. Needless to say, high
pressure over the Great Lakes is on the way. This surface high will
push south and bring drier air into the region through the
short-term period. Only hang up will be added cloud cover near the
stalled boundary across the TN/KY border. Think this boundary will
eventually push south into TN today, so precip should remain south
of our CWA with dry weather forecast.
With clear skies for the most part today, think we`ll be able to
reach the upper 70s northeast into the lower 80s southwest. With
high pressure continuing on Friday and even more dry air in place,
good mixing and veering winds will allow for temps to climb even
higher, with low to mid 80s being the rule under sunny skies again.
Lows tonight will drop into the low to mid 50s with no fog expected.
.Long Term (Friday Night through Wednesday)...
Issued at 250 AM EDT May 17 2012
A mostly dry and quite warm weekend is setting up for the region as
we remain under the influence of surface high pressure and an upper
level ridge. Regarding precip chances Saturday and Sunday afternoon,
there is still a lot of uncertainty as to whether any storms will
be able to develop. The GFS continues to develop some precip, though
it now paints the best chance on Sunday across the entire are, with
less on Saturday. The ECMWF remains dry and we will continue to
advertise a dry solution for now, though pops may be needed at some
point in time. With southerly winds and mostly sunny skies under the
high pressure, temperatures will be quite warm this weekend. Highs
will top out in the mid to upper 80s with lows in the lower 60s.
A front will begin to approach the region on Monday and move through
Monday night into Tuesday. Isolated to scattered thunderstorms will
develop ahead of this front on Monday. Storm coverage will increase
Monday night and Tuesday as the front passes through the area.
Beyond Tuesday the forecast is a bit less certain. The GFS is much
faster than the ECMWF at clearing things out behind the front as the
ECMWF is slower to move out an upper level low. There is quite a bit
of spread in the ensembles on precip chances for Wednesday, so will
carry a slight chance of shower/storms for now. With increased
cloud/precip coverage Monday through Wednesday, high temperatures
will be a bit cooler, in the upper 70s to lower 80s. Lows will
continue to drop into the lower 60s.
&&
.Aviation (06Z TAF Issuance)...
Updated at 645 AM EDT May 17 2012
The weak cold front is still located across south-central KY. Based
on BWG`s pressure, it may be just south of that location. Winds will
remain light and variable at BWG for another 1-2 hours with a light
haze, as well. Otherwise, this boundary will slowly sag southward,
possibly leading to a stray shower near the BWG terminal through
18z. Will keep BWG dry though due to limited coverage. North of this
boundary, LEX and SDF will continue to have decent northeasterly
winds today (8-12 knots on average) with a few higher gusts. Expect
FEW mid-level clouds at those terminals through midday with clear
skies thereafter. With the front nearby, more SCT cloud coverage
will affect BWG with cloud bases from 6-12kft.
Tonight, skies will clear at all locations as winds veer a little to
the east, not quite tapering off to calm overnight.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........13
Short Term.......AL
Long Term........EER
Aviation.........13
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
730 AM EDT THU MAY 17 2012
.SYNOPSIS...
ISSUED AT 512 AM EDT THU MAY 17 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE FROM
THE PLAINS INTO CNTRL CANADA AND A DOWNSTREAM TROUGH FROM QUEBEC
INTO THE NE CONUS RESULTING IN NW FLOW THROUGH THE NRN GREAT LAKES.
AT THE SFC...HIGH PRES WAS CENTERED OVER LOWER MI WHILE LOW PRES WAS
DEVELOPING OVER THE PLAINS FROM SRN SASK INTO WRN SOUTH DAKOTA. MID
LEVEL WARM ADVECTION AHEAD OF A WARM FRONT OVER THE CNTRL PLAINS
SUPPORTED DEVELOPING SHRA AND A FEW TSRA OVER SW MN.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 512 AM EDT THU MAY 17 2012
TODAY...EXPECT THE BAND OF STRONGER 310K ISENTROPIC LIFT AND
POSITION OF THE 750-650 MB WARM FRONT TO EXPAND TO THE ENE
TODAY...PER NAM/GFS. HOWEVER...SINCE THE PCPN IS MOVING AWAY FROM
THE GREATER LOW LEVEL MOISTURE INTO THE DRY LOW LEVEL AIRMASS TO THE
EAST...PER 00Z MPX/INL/GRB SOUNDINGS...THE PCPN SHOULD REMAIN LIGHT
AND MAINLY TO THE WEST AND SOUTH OF THE CWA. LOCATIONS FROM IWD-IMT
WILL SEE THE BEST CHANCE OF ANY PCPN BUT ONLY SLIGHT CHANCE POPS
WERE INCLUDED WITH ANY PCPN AMOUNTS LESS THAN A TENTH OF AN INCH.
OTHERWISE...WAA WILL HELP PUSH TEMPS INTO THE MID 50S TO LOWER 70S
DESPITE AN INCREASE IN MID HIGH CLOUDS.
TONIGHT...THE FOCUS OF THE LLJ AND STRONGEST MOISTURE TRANSPORT IS
EXPECTED OVER NE MN AND NW WI INTO WRN LAKE SUPERIOR. AREAS OF
SHRA/TSRA SHOULD DEVELOP AND EVENTUALLY SPREAD TO THE EAST AFFECTING
MAINLY THE NW HALF OF THE CWA AS THE LLJ VEERS OVERNIGHT.
HOWEVER...THERE IS STILL SIGNIFICANT UNCERTAINTY WITH THE
TIMING/POSITION OF THE CONVECTION.
FRIDAY...ANY LEFTOVER SHRA/TSRA OVER MAINLY NORTH UPPER MI INTO LAKE
SUPERIOR SHOULD SLIDE TO THE ENE AND DIMINISH DURING THE MORNING AS
THE LLJ WEAKENS. THE COMBINATION OF BUILDING MID-LVL RDG HEIGHTS AND
850 MB WARM FRONT LIFTING WELL NORTH OF THE AREA SHOULD KEEP THE CWA
DRY FRI AFTERNOON. RESIDUAL CLOUDS FROM CONVECTION SHOULD DISSIPATE
FRI AFTERNOON ALLOWING FOR INCREASED SUNSHINE. MIXING OF 850 MB
TEMPS OF AROUND 16C TO THE SFC SHOULD ALLOW FOR HIGH TEMPS FRIDAY TO
REACH INTO THE LOWER 80S OVER WRN INTERIOR LOCATION. COOLER SRLY
FLOW OFF LAKE MI WILL KEEP INLAND HIGHS OVER ERN COUNTIES IN THE LOW
TO MID 70S.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 512 AM EDT THU MAY 17 2012
PERIOD STARTS 00Z SAT WITH A 500MB RIDGE OVER THE CWA...AND A 500MB
TROUGH OVER THE INTERMOUNTAIN WEST. AT THE SFC...994MB LOW PRESSURE
WILL BE STRETCHED E FROM ERN CO TO SRN ND...AND WITH HIGH PRESSURE
SITTING OVER THE ERN SEABOARD...THAT PUTS US UNDER S/SSW FLOW.
THAT/S RIGHT...WE WILL BE IN THE WARM SECTOR AS THE WARM FRONT
ASSOCIATED WITH THE SYSTEM TO OUR W WILL BE N OF LAKE SUPERIOR BY 00Z
SAT. AND WARM IT WILL BE WITH 850MB TEMPS AROUND 17C.
FRI NIGHT AND SAT...SOLID S/SW FLOW IN THE WARM LOW LEVELS WILL KEEP
TEMPS FROM FALLING TOO FAR FRI NIGHT...ESPECIALLY IN DOWNSLOPING
AREAS. HAVE LOW TEMPS AROUND 60 IN THE DOWNSLOPE AREAS...AND IN THE
UPPER 40S TO 50S ELSEWHERE. WITH HIGHER DEW PTS AND WAA...COULD SEE
FOG OVER MAINLY NRN LAKE SUPERIOR AND EVENTUALLY NRN LAKE MI /WHICH
WOULD LAST UNTIL FROPA SUNDAY/...WHICH I ADDED TO THE FORECAST FOR
FRI NIGHT THROUGH SUN. 850MB TEMPS STAY AROUND 17C THROUGH
SAT...WITH GOOD S/SW FLOW CONTINUING...ALLOWING MIXING TO AROUND
800MB. THIS YIELDS HIGH TEMPS IN THE 80S OVER THE W HALF AND NEAR
LAKE SUPERIOR OVER THE E HALF...WITH HIGHS IN THE 60S CLOSE TO NRN
LAKE MI DUE TO S/SSW FLOW OF THE RELATIVELY COLD LAKE. ATMOSPHERE
LOOKS TOO DRY AND TOO CAPPED FOR CONVECTION TO FORM ON SAT...WHICH
IS GOOD SINCE WE SHOULD HAVE 1500-2000J/KG OF CAPE SAT AFTERNOON.
LOWERED DEW PTS A FEW DEGREES AS MIXING WILL ALLOW DRY AIR TO GET TO
THE SFC. THIS LEADS TO MIN RH VALUES DOWN OF 25 TO 35 PERCENT OVER
THE W HALF OF UPPER MI...AND GREATER THAN 35 PERCENT RH OVER THE E
HALF. THIS BECOMES MORE PROBLEMATIC WHEN CONSIDERING WINDS WILL BE
SLY AT 15-20MPH WITH GUSTS OF 25-35MPH. LOOKS LIKE IT MAY BE A
CRITICAL FIRE WEATHER DAY...BUT THAT WILL NEED TO BE LOOKED AT MORE
CLOSELY BY LATER SHIFTS FOR POSSIBLE FIRE WEATHER HEADLINES.
SAT NIGHT THROUGH MON...BY 00Z SUN...THE UPPER TROUGH WILL HAVE MOVED
FARTHER E...WITH A SHORTWAVE TROUGH OVER MANITOBA...AND POSSIBLY
ANOTHER OVER KS/NE. THE SFC LOW WILL HAVE WEAKENED TO 1002MB AS IT
MOVED TO N OF THE MN ARROWHEAD. THIS PUTS THE COLD JUST W OF LAKE
SUPERIOR AT 00Z SUN. SAT NIGHT WILL BE ANOTHER WARM ONE WITH
CONTINUED STRONG LOW LEVEL FLOW AND WARM LOW LEVEL TEMPS. OVERNIGHT
LOWS LOOK TO BE IN THE 50S AND LOW 60S. DIFFERING MODEL SOLUTIONS
BEGIN TO LOWER CONFIDENCE ON EXACT TIMING OF THE COLD FRONT/PRECIP
DUE MAINLY WITH HOW TO HANDLE A SHORTWAVE MOVING AROUND THE MAIN
UPPER TROUGH SAT NIGHT INTO SUN. THE GFS CONTINUES TO BE THE MOST
AGGRESSIVE WITH THE SHORTWAVE...SHOWING IT STRONGER THAN PRETTY MUCH
ANY OTHER MODEL. THIS MEANS THE GFS ALSO BRINGS THE COLD FRONT
THROUGH FASTER THAN OTHER MODELS. FOR THIS REASON...WILL NOT PUT AS
MUCH OF THE GFS INTO THIS FORECAST. WITH THE IDEA THAT THE GFS IS
ABOUT 6 HOURS TOO FAST WITH FROPA...THE FRONT SHOULD MOVE OVER WRN
UPPER MI SUN AFTERNOON...AND MOVE TO ERN UPPER MI BY 12Z MON...NOTE
THE SLOW EASTWARD PROGRESSION OF THE FRONT. SBCAPES OF AROUND
1000-1500J/KG WILL BE POSSIBLE SUN AFTERNOON AHEAD OF THE
FRONT...BUT CONFIDENCE IN THIS IS A BIT LOW RIGHT NOW DUE TO MODEL
TIMING DIFFERENCES AND UNCERTAINTY IN HOW MUCH CLEARING WILL OCCUR
AHEAD OF THE FRONT. 0-6KM BULK SHEAR LOOKS TO BE AROUND
30KTS...SUFFICIENT FOR ORGANIZED CONVECTION. SO...IT LOOKS LIKE SOME
STRONG TO SEVERE STORMS WILL BE A POSSIBILITY SUN
AFTERNOON/EVENING...BUT CONFIDENCE IS STILL LIMITED. THE COLD FRONT
LOOKS TO COMPLETELY CLEAR THE CWA AROUND 18Z MON...AS THE UPPER
TROUGH AND A SFC RIDGE MOVE INTO THE WRN CWA. 850MB TEMPS OF AROUND
7C MON AFTERNOON WILL MAKE FOR COOLER TEMPS IN THE 60S...EXCEPT IN
THE 50S NEAR LAKE SUPERIOR IN THE NLY WINDS.
MON NIGHT THROUGH WED...EXPECT A GRADUAL WARMING TREND AS AN UPPER
RIDGE MOVES OVERHEAD AND SFC RIDGING SLOWLY MOVES TO E OF THE CWA BY
WED AFTERNOON.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 729 AM EDT THU MAY 17 2012
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH THE PERIOD.
MAIN ITEM OF CONCERN IS POTENTIAL SHOWERS APPROACHING KIWD TODAY.
MUCH OF IT DEPENDS ON HOW AND WHERE SHOWERS OVER SOUTHERN MN WILL
RIDE NE TOWARD WITH THE INCREASING SRLY FLOW TODAY. LIMITED
CONFIDENCE ON THIS OCCURRING...SO WILL LEAVE OUT OF THE FORECAST
GIVEN DRY LOW LEVELS. LLWS STILL EXPECTED AT ALL OF THE TAF SITES
FOR THIS EVENING AND TONIGHT WITH THE STRONG LLVL JET MOVING OVER
UPPER MI. MORE SHOWERS MAY APPROACH CMX TONIGHT...BUT AGAIN KEPT
THOSE OUT OF THE FORECAST GIVEN DRY LOW LEVELS AND LIMITED
CONFIDENCE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EDT THU MAY 17 2012
WINDS ACROSS LAKE SUPERIOR SHOULD REMAIN BELOW 30KTS THROUGH THE
PERIOD. HIGH PRESSURE ACROSS THE UPPER GREAT LAKES WILL SHIFT TO THE
LOWER GREAT LAKES THIS AFTERNOON...BEFORE PUSHING OFF THE MID
ATLANTIC SHORELINE ON FRIDAY INTO SATURDAY. LOW PRESSURE OVER
SOUTHERN SASKATCHEWAN AND THE WESTERN DAKOTAS WILL PUSH ACROSS THE
NORTHERN AND CENTRAL PLAINS TONIGHT THROUGH SATURDAY...BEFORE
SLIDING NORTH INTO ONTARIO SATURDAY. THIS WILL ALLOW A COLD FRONT TO
PUSH ACROSS THE UPPER GREAT LAKES SUNDAY INTO EARLY MONDAY. BEHIND
THE FRONT...HIGH PRESSURE WILL BUILD IN FROM THE CENTRAL AND
NORTHERN PLAINS THROUGH TUESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MIZ006-007-013-
014-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1007 AM CDT THU MAY 17 2012
.DISCUSSION.../ISSUED AT 1007 AM CDT/
NOT MUCH CHANGE TO CURRENT FORECAST. ACCAS SHOWERS NORTH OF WARM
FRONT HAS EXITED CWA WITH PARTLY TO MOSTLY SUNNY SKIES EXPECTED THIS
AFTERNOON. WINDS WILL BE GUSTY THIS AFTERNOON AND WILL BE CLOSE TO
WIND ADVISORY CRITERIA BUT WILL NOT ISSUE SINCE EVERYONE PRETTY MUCH
KNOWS IT IS WINDY. CURRENT TEMPERATURE FORECAST ON TRACK.
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED TO REMAIN THROUGH FRIDAY MORNING. A STRONG
LOW LEVEL JET WILL CONTINUE TO PRODUCE LOW LEVEL WIND SHEAR AT THE
TAF SITES EAST OF THE JAMES RIVER VALLEY THROUGH 18Z. THESE STRONGER
WINDS WILL BEGIN TO MIX OUT BY 15Z INCREASING THE SURFACE SPEEDS...
GUSTING UP TO 35 KTS DURING THE AFTERNOON MOST LOCATIONS. SURFACE
WIND GUSTS WILL DECREASE SOME OVERNIGHT THURSDAY NIGHT...THOUGH
WINDS WILL REMAIN STRONG ALOFT CREATING ADDITIONAL LOW LEVEL WIND
SHEAR FRIDAY MORNING.
&&
.PREVIOUS DISCUSSION.../ISSUED AT 355 AM CDT/
WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS HAVE
DEVELOPED FROM JUST WEST OF SIOUX FALLS NORTHWARD ALONG THE
INTERSTATE 29 CORRIDOR OVERNIGHT UNDER THE INFLUENCE OF WARM
AIR/THETA E ADVECTION FACILITATED BY THE LOW LEVEL JET. ELEVATED
CONVECTION ALIGNS FAIRLY WELL WITH THE RUC 850-500MB OMEGA AND
INSTABILITY FIELDS...ALBEIT BOTH ARE RELATIVELY WEAK. THEREFORE
EXPECT THE ACTIVITY TO REMAIN ISOLATED IN NATURE. CONSIDERING WINDS
ARE HAULING AT 50-60 KTS AT TWO THOUSAND FEET...WILL NEED TO KEEP A
CLOSE EYE ON CELLS THAT DEVELOP AS THEY COULD BE WIND PRODUCERS. BY
DAYBREAK...ISOLATED ACTIVITY SHOULD BE MOSTLY CONFINED TO SW
MN...AND GRADUALLY WANE WITH LOSS OF THE LLJ INFLUENCE.
AFTER THE NOCTURNAL CONVECTION...THE NEXT ITEM OF FOCUS IS THE WIND
TODAY AND FRIDAY. 08Z SURFACE ANALYSIS ILLUSTRATED THE LOW
PRESSURE CENTER OVER WESTERN ND/SD. RELATIVELY TIGHT PRESSURE
GRADIENT AHEAD OF THIS FEATURE WILL SUPPORT WIND SPEEDS NEARING
ADVISORY CRITERIA /SUSTAINED 30 MPH/. NAM BUFKIT WINDS AT THE TOP OF
THE MIXED LAYER ARE CIRCA 40 KTS...BUT THERE WILL BE INCREASING
HIGH CLOUDS. WHILE ISOLATED LOCATIONS /ESPECIALLY HIGHER TERRAIN
AREAS/ COULD BRIEFLY HIT CRITERIA...DO NOT CURRENTLY EXPECTED
WIDESPREAD SUSTAINED SPEEDS AT 30 MPH. THEREFORE...WILL HOLD OFF
ON AN ADVISORY FOR NOW. TEMPERATURES WILL SOAR NEARLY 15 DEGREES
ABOVE NORMAL FOR THIS TIME OF YEAR...WITH HIGHS IN THE MID/UPPER
80S STILL APPEARING LIKELY.
LOWS TONIGHT WILL NOT DROP MUCH DUE TO THE PERSISTENT SOUTHERLY
FLOW AHEAD OF THE TROUGH. LOW TO MID 60S ARE EXPECTED TO BE COMMON
AT DAYBREAK FRIDAY. H85 TEMPERATURES CLIMB TO AROUND +22C ON
FRIDAY...WHICH SHOULD MAKE UPPER 80S AND LOWER 90S EASILY
ATTAINABLE.
THE COLD FRONT SHOULD REACH CENTRAL SD BY DAYBREAK SATURDAY...AND
TRACK EASTWARD ACROSS THE FORECAST AREA THROUGHOUT THE DAY. LIKELY
POPS SEEM WARRANTED ON SATURDAY AND SATURDAY NIGHT. INSTABILITY
AND SHEAR PARAMETERS ARE RATHER MARGINAL ON SATURDAY...SO SEVERE
THREAT STILL APPEARS TO BE FARTHER SOUTH. A FEW SHOWERS MAY LINGER
ON SUNDAY MAINLY EAST OF INTERSTATE 29...AND THEN RIDGING WILL
DEVELOP FOR THE START OF NEXT WEEK. AFTER TEMPERATURES ARE REDUCED
BACK INTO HE MID 60S TO LOWER 70S RANGE ON SUNDAY IN THE WAKE OF
THE FRONT...READINGS WILL GRADUALLY MODERATE TO VALUES IN THE
UPPER 70S AND LOWER 80S FOR TUESDAY.
SHOWER AND THUNDERSTORM CHANCES WILL RETURN FOR WEDNESDAY AND
THURSDAY...AS A RELATIVELY HEALTHY TROUGH TRACKS ACROSS THE NORTH
CENTRAL CONUS. HAVE INCLUDED 50-70 POPS FOR THIS SYSTEM.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1022 AM CDT THU MAY 17 2012
.SHORT TERM...
1022 AM CDT THU MAY 17 2012
MAIN FORECAST CONCERNS FOR THE AFTERNOON ARE WINDS AND DEWPOINTS.
15Z SURFACE ANALYSIS SHOWS LOW PRESSURE OVER THE DAKOTAS WITH A
PRESSURE FALL AREA OF NEAR 1 MB/HOUR OVER CENTRAL AND NORTHERN
MINNESOTA. THIS PRESSURE FALL AREA HAS BEEN TRANSLATING EASTWARD
THROUGH THE MORNING. THE PRESSURE GRADIENT HAS ALSO BEEN GRADUALLY
TIGHTENING THROUGH THE MORNING FROM WESTERN IOWA THROUGH MUCH OF
MINNESOTA. 12Z SOUNDING FROM MPX SHOWED A VERY DRY SOUNDING BELOW
650MB...BUT ALSO IMPORTANTLY 40 KT WINDS NEAR 950MB. A FEW SITES
THAT ARE ON THE HIGHER TERRAIN JUST SOUTH OF THE MINNESOTA RIVER
VALLEY HAVE BEEN EXPERIENCING WINDS OF 30 TO 40 MPH AND GUSTS NEAR
50 MPH. MEANWHILE...ALTOSTRATUS CLOUDS WITH BASES OF 9000 FT OR
HIGHER HAVE BEEN PUSHING EAST ACROSS MINNESOTA AND THE NORTH HALF OF
WISCONSIN...A RESULT OF ISENTROPIC LIFT IN THE WARM ADVECTION
PATTERN IN PLACE AHEAD OF THE LOW. IN ADDITION...ON WATER VAPOR A
SHORTWAVE TROUGH IS EVIDENT IN THE EASTERN DAKOTAS...LIKELY HELPING
OUT TOO TO PRODUCE THE CLOUDS. RADAR SHOWING SOME
PRECIPITATION...BUT MOST OF THIS HAS REMAINED AS VIRGA DUE TO THE
DRY SUB CLOUD AIR SEEN ON THAT MPX SOUNDING. KRST JUST REPORTED A
SPRINKLE...SO A LITTLE OF THIS VIRGA IS REACHING THE SURFACE.
REGARDING DEWPOINTS...THEY HAVE COME UP A LITTLE BIT DUE TO THE
NORMAL DIURNAL INCREASE...BUT THERE ARE LOWER ONES LURKING IN
SOUTHEAST IOWA (LOW TO MID 30S THERE).
WITH THE PRESSURE FALL AREA ANTICIPATED TO CONTINUE TRANSLATING
EASTWARD AND THE PRESSURE GRADIENT TIGHTENING...AND ALL OF THIS
HAPPENING DURING THE PEAK HEATING OF THE DAY...CONCERNED THAT
WINDS COULD TRY TO PUSH ADVISORY CRITERIA. CLOUDS RIGHT NOW OVER
MINNESOTA AND NORTHERN WISCONSIN ARE HOLDING MIXING DOWN
SOME...BUT THESE SHOULD DISSIPATE IN THE AFTERNOON AS THE
SHORTWAVE TROUGH WEAKENS AND PUSHES EAST...ALONG WITH THE
ISENTROPIC LIFT SHIFTING NORTH. 06Z MAV/00Z MET GUIDANCE BOTH
PUSH KRST AND KTOB TO AROUND 25 KT AT 21Z...WITH LATEST RAP
GUIDANCE SUGGESTING THE SAME THING. THESE SPEEDS ARE CLOSE TO
ADVISORY CRITERIA. AFTER COLLABORATION WITH MPX...DECIDED TO ERR
ON THE CAUTIOUS SIDE AND ISSUE THE ADVISORY FOR SOUTHEAST
MINNESOTA. TYPICALLY SOME OF NORTHEAST IOWA IS INCLUDED IN THESE
ADVISORY SITUATIONS TOO...BUT IT APPEARS RIGHT NOW THAT WINDS
ACROSS NORTHEAST IOWA WILL STAY BELOW ADVISORY CRITERIA.
REGARDING DEWPOINTS...WITH A PERSISTENT SOUTH FLOW...CONCERNED
THAT LOWER DEWPOINTS IN SOUTHEAST IOWA COULD ADVECT INTO THE
FORECAST AREA. CERTAINLY THE LACK OF RAIN LATELY WOULD SUPPORT
DEWPOINTS MIXING OUT...THOUGH WE HAVE GREENED UP. RAP RUNS HAVE
SUGGESTED DEWPOINTS DROPPING INTO THE 20S WITH SOUNDINGS THAT
SUGGEST LITTLE HELP FROM EVAPOTRANSPIRATION. MEANWHILE MOST OTHER
MODELS SUGGEST UPPER 30S TO LOW 40S AT BEST. FOR NOW HAVE
DISCOUNTED THE RAP RUNS...BUT LEANED TO THE LOW SIDE OF ALL OTHER
GUIDANCE. WILL BE INTERESTING TO SEE HOW LOW DEWPOINTS GET TODAY.
IF WE WERE NOT GREENED UP...TODAY WOULD BE CONCERNING FOR FIRE
WEATHER.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
315 AM CDT THU MAY 17 2012
17.00Z ECMWF/GFS STILL SHOWING DIFFERENCE IN TIMING OF THE COLD
FRONTAL PASSAGE ACROSS THE AREA/ASSOCIATED SHRA/TS CHANCES IN THE
SATURDAY NIGHT/SUNDAY TIME FRAME. THE GFS REMAINS THE FASTER OF
THE TWO MODELS WITH PASSAGE AROUND 18Z WHEREAS THE ECMWF HOLDS OFF
TIL EVENING. WITH THIS UNCERTAINTY...WILL KEEP MODEL CONSENSUS
APPROACH GOING FOR NOW. WITH SLOWER TIMING...THERE STANDS A CHANCE
FOR STRONG/SEVERE THUNDERSTORMS WITH AMPLE CAPE/BULK SHEAR
DEPICTED BY THE ECMWF. HOPEFULLY THE MODELS WILL HAVE THIS
RESOLVED A BIT BETTER WITHIN THE NEXT FEW RUNS. MODELS THEN KEEP
DIFFERENCES GOING THROUGH THE REMAINDER OF THE PERIOD WITH THE GFS
MAINTAINING A MORE PROGRESSIVE WAVE PATTERN COMPARED TO THE ECMWF.
ECMWF KEEPS TROUGH/COOLER CYCLONIC FLOW AROUND THE AREA SUNDAY
NIGHT THROUGH TUESDAY FOR A SMALL CHANCE OF SHOWERS/ISOLATED
THUNDER. THE GFS BRINGS RIDGING IN FAIRLY QUICK FOR A DRIER
SOLUTION. WILL KEEP MODEL CONSENSUS GOING HERE AS WELL DUE TO THE
UNCERTAINTY. UPPER/SURFACE FLOW BECOMES SOUTHERLY ON WEDNESDAY
WITH BOTH MODELS SHOWING A WEAK EMBEDDED WAVE ALOFT. THE ECMWF
SHOWS LIGHT QPF SIGNAL WITH THIS FEATURE WHILE THE GFS REMAINS
DRY. WILL INCLUDE A SLIGHT CHANCE OF SHOWERS/THUNDER FOR NOW.
OTHERWISE...LOOKS LIKE TEMPERATURES WILL START OFF SOME 10 DEGREES
ABOVE NORMAL ON SUNDAY IN THE MID 70-LOWER 80S...THEN NEAR NORMAL
IN THE 70S MON/TUE/WED.
&&
.AVIATION...TODAY AND TONIGHT
618 AM CDT THU MAY 17 2012
BREEZY VFR CONDITIONS EXPECTED THROUGH THE PERIOD. AS A STORM
SYSTEM DEVELOPS OVER SOUTH DAKOTA TODAY...THE GRADIENT WILL
TIGHTEN OVER THE REGION. THIS WILL PRODUCE SOUTH WINDS AT BOTH TAF
SITES WITH SUSTAINED SPEEDS AROUND 20 KNOTS. GUSTS WILL DEVELOP BY
MID TO LATE MORNING AND CONTINUE INTO THE EARLY EVENING. KLSE
SHOULD GUST TO AROUND 25 KNOTS WITH GUSTS TO AROUND 30 KNOTS
EXPECTED AT KRST. THE GUSTS SHOULD DIMINISH BY EARLY EVENING BUT
LOOK FOR SUSTAINED SPEEDS TO REMAIN BETWEEN 10 AND 15 KNOTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1022 AM CDT THU MAY 17 2012
WI...NONE.
MN...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING
FOR MNZ079-086-087-094-095.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
618 AM CDT THU MAY 17 2012
.SHORT TERM...TONIGHT THROUGH SATURDAY
315 AM CDT THU MAY 17 2012
FORECAST CONCERNS INCLUDE SHRA CHANCES ACROSS THE NORTH TODAY AND
THEN INCREASING WARMTH THROUGH THE REMAINDER OF THE PERIOD.
LATEST WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW RIDGING OVER THE
IMMEDIATE FORECAST AREA WITH A WEAK MID-LEVEL TROUGH OVER THE
NORTHERN PLAINS. SURFACE ANALYSIS AT 3 AM HAS HIGH PRESSURE OVER THE
GREAT LAKES REGION WITH AN AREA OF LOW PRESSURE OVER THE NORTHERN
PLAINS. A WARM FRONT EXTENDED FROM THIS LOW EAST-SOUTHEASTWARD
ACROSS SOUTHERN MN INTO NORTHEAST IA. MOISTURE TRANSPORT/ISENTROPIC
LIFT AHEAD OF THE LOW AND OVER THE WARM FRONT WAS PRODUCING SOME
VERY HIGH-BASED SHRA/ISOLATED THUNDER ACROSS CENTRAL SD INTO FAR
SOUTHWEST MN.
17.00Z NCEP MODELS/17.21Z SREF IN GOOD AGREEMENT WITH OVERALL
SYNOPTIC SETUP THROUGH THE PERIOD.
FOR TODAY...LOW PRESSURE WILL STAY PUT ACROSS THE NORTHERN PLAINS AS
THE WARM FRONT LIFTS NORTH INTO CENTRAL MN/NORTHERN WI BY EARLY THIS
EVENING. AXIS OF LIGHT TO MODERATE 925-850MB MOISTURE TRANSPORT
STAYS NORTH OF THE AREA WITH BULK FAIRLY STRONG ISENTROPIC LIFT
FOLLOWING SUIT. EITHER WAY...LOWEST 700-600MB VERY DRY AS EVIDENCED
BY THE 17.00Z MPX SOUNDING AND NAM BUFKIT SOUNDINGS. MOST SHRA
ACTIVITY WILL BE FALLING OUT OF ACCAS CLOUD AT OR ABOVE 10-12KFT.
WOULD TAKE VIGOROUS CONVECTION FOR ANYTHING TO REACH THE GROUND. AS
SUCH...HAVE TRIMMED POPS FARTHER NORTH AND KEPT A SMALL CHANCE OF
SHRA/ISOLD THUNDER CONFINED NORTH OF HIGHWAY 10 IN WISCONSIN.
OTHERWISE...LOOK FOR INCREASING SOUTH WINDS TODAY WITH INCREASING
PRESSURE GRADIENT. WINDS ACROSS MUCH OF THE AREA SHOULD BE IN THE
15-25 MPH RANGE...BUT THE HIGHER/MORE WIND-PRONE AREAS OF SOUTHEAST
MN/NORTHEAST IA WILL LIKELY SEE WINDS MORE IN THE 20-25 MPH RANGE
WITH GUSTS AROUND 35 MPH. WITH WARM ADVECTION/RISING MOTIONS IN THE
BOUNDARY LAYER MITIGATING DOWNWARD TRANSFER OF STRONGER WINDS
ALOFT...FEEL WINDS WILL BE JUST SHY OF WIND ADVISORY. WILL HAVE TO
KEEP A CLOSE EYE ON THIS. TEMPERATURES ARE EXPECTED TO RESPOND TO
INCREASING SOUTHERLY FLOW WITH AFTERNOON HIGHS TOPPING OFF IN THE
UPPER 60S ACROSS NORTHERN WISCONSIN...TO THE MID-UPPER 70S
ELSEWHERE.
WARM FRONT PUSHES NORTH OF THE AREA THIS EVENING WITH A STRONG CAP
SETTING UP ACROSS THE AREA IN THE WARM SECTOR ON FRIDAY. WITH MOSTLY
SUNNY SKIES AND STRONG SOUTHERLY FLOW...TEMPERATURES SHOULD HAVE NO
PROBLEM REACHING INTO THE UPPER 70S TO MIDDLE 80S. DEW POINTS WILL
ALSO BE ON THE RISE INTO THE 50S FOR A SLIGHTLY MORE MUGGY FEEL
COMPARED TO THE LAST FEW DAYS.
COLD FRONT AND ASSOCIATED CONVECTION OVER THE NORTHERN PLAINS MAKES A MOVE
EASTWARD INTO MN/WESTERN IA ON SATURDAY WITH CAP HOLDING FIRM ACROSS
OUR FORECAST AREA. CONTINUED STRONG SOUTHERLY FLOW AND PARTLY TO
MOSTLY SUNNY SKIES SHOULD PUSH TEMPERATURES INTO THE MID-UPPER 80S.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
315 AM CDT THU MAY 17 2012
17.00Z ECMWF/GFS STILL SHOWING DIFFERENCE IN TIMING OF THE COLD
FRONTAL PASSAGE ACROSS THE AREA/ASSOCIATED SHRA/TS CHANCES IN THE SATURDAY
NIGHT/SUNDAY TIME FRAME. THE GFS REMAINS THE FASTER OF THE TWO
MODELS WITH PASSAGE AROUND 18Z WHEREAS THE ECMWF HOLDS OFF TIL
EVENING. WITH THIS UNCERTAINTY...WILL KEEP MODEL CONSENSUS APPROACH
GOING FOR NOW. WITH SLOWER TIMING...THERE STANDS A CHANCE FOR
STRONG/SEVERE THUNDERSTORMS WITH AMPLE CAPE/BULK SHEAR DEPICTED BY
THE ECMWF. HOPEFULLY THE MODELS WILL HAVE THIS RESOLVED A BIT BETTER
WITHIN THE NEXT FEW RUNS. MODELS THEN KEEP DIFFERENCES GOING THROUGH
THE REMAINDER OF THE PERIOD WITH THE GFS MAINTAINING A MORE
PROGRESSIVE WAVE PATTERN COMPARED TO THE ECMWF. ECMWF KEEPS
TROUGH/COOLER CYCLONIC FLOW AROUND THE AREA SUNDAY NIGHT THROUGH
TUESDAY FOR A SMALL CHANCE OF SHOWERS/ISOLATED THUNDER. THE GFS
BRINGS RIDGING IN FAIRLY QUICK FOR A DRIER SOLUTION. WILL KEEP MODEL
CONSENSUS GOING HERE AS WELL DUE TO THE UNCERTAINTY. UPPER/SURFACE
FLOW BECOMES SOUTHERLY ON WEDNESDAY WITH BOTH MODELS SHOWING A WEAK
EMBEDDED WAVE ALOFT. THE ECMWF SHOWS LIGHT QPF SIGNAL WITH THIS
FEATURE WHILE THE GFS REMAINS DRY. WILL INCLUDE A SLIGHT CHANCE OF
SHOWERS/THUNDER FOR NOW. OTHERWISE...LOOKS LIKE TEMPERATURES WILL
START OFF SOME 10 DEGREES ABOVE NORMAL ON SUNDAY IN THE MID 70-LOWER
80S...THEN NEAR NORMAL IN THE 70S MON/TUE/WED.
&&
.AVIATION...TODAY AND TONIGHT
618 AM CDT THU MAY 17 2012
BREEZY VFR CONDITIONS EXPECTED THROUGH THE PERIOD. AS A STORM
SYSTEM DEVELOPS OVER SOUTH DAKOTA TODAY...THE GRADIENT WILL
TIGHTEN OVER THE REGION. THIS WILL PRODUCE SOUTH WINDS AT BOTH TAF
SITES WITH SUSTAINED SPEEDS AROUND 20 KNOTS. GUSTS WILL DEVELOP BY
MID TO LATE MORNING AND CONTINUE INTO THE EARLY EVENING. KLSE
SHOULD GUST TO AROUND 25 KNOTS WITH GUSTS TO AROUND 30 KNOTS
EXPECTED AT KRST. THE GUSTS SHOULD DIMINISH BY EARLY EVENING BUT
LOOK FOR SUSTAINED SPEEDS TO REMAIN BETWEEN 10 AND 15 KNOTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 AM CDT THU MAY 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS MIAMI FL
159 PM EDT THU MAY 17 2012
.AVIATION...VFR PREVAILS. THERE HAVE BEEN PERIODS OF MVFR CIGS.
HOWEVER, THEY`VE BROKEN UP IN THE PAST HOUR. BIG CHALLENGE IS WITH
REGARDS TO CONVECTION. LIKE YESTERDAY, THE AREA IS SHROUDED IN
CLOUD COVER AND TEMPERATURES ARE ONLY IN THE LOWER 80S. HOWEVER,
THERE IS A SOUTHEAST WIND ALONG THE ATLANTIC COAST SO WE COULD
STILL GET CONVERGENCE AND THE DEVELOPMENT OF SHRA/TSRA IN THE NEXT
FEW HOURS...SO MAINTAINED TEMPO FOR TSRA. ANY STORMS COULD PRODUCE
BRIEF IFR CONDITIONS ALONG WITH STRONG WIND GUSTS, SHOULD THEY
DEVELOP. ANY ACTIVITY WHICH DEVELOPS IS EXPECTED TO GRADUALLY WANE
THIS EVENING...BUT MAINTAINED VCSH OVERNIGHT. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 908 AM EDT THU MAY 17 2012/
UPDATE...
SOME CHANGES WERE MADE TO THE SHORT TERM FORECAST. THE SHORT TERM
WIND FORECAST IS PROBLEMATIC IN THAT THE CONVECTION THAT PASSED
THROUGH THE REGION EARLIER THIS MORNING DISRUPTED THE SYNOPTIC
FLOW AND THE WINDS ARE CURRENTLY SOMEWHAT VARIABLE. BUT THE
CONSENSUS OF THE LATEST GUIDANCE SUGGESTS THAT A SOUTH TO
SOUTHWESTERLY FLOW IS LIKELY TO BECOME RE-ESTABLISHED ACROSS THE
REGION LATER THIS MORNING OR THIS AFTERNOON. ALSO UPDATED THE
MARINE FORECAST TO REFLECT THE SHOWER AND THUNDERSTORM ACTIVITY
ACROSS THE ATLANTIC WATERS FROM EARLIER THIS MORNING BUT THE
THUNDERSTORM ACTIVITY IS CURRENTLY SUBSIDING. FOR THE FORECAST FOR
THE REMAINDER OF THE DAY...WILL LEAVE CURRENT FORECAST FOR
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. ALTHOUGH ACTIVITY
HAS SUBSIDED THIS MORNING...SEVERAL SYNOPTIC FACTORS SUGGEST THAT
CONVECTION COULD START LATER THIS MORNING OR INTO THE AFTERNOON.
THE FACTORS INCLUDE AN UPPER LEVEL JET PASSING THROUGH THE
REGION AND LOW LEVEL MASS AND MOISTURE CONVERGENCE CONTINUING
ACROSS THE REGION. PLUS RECENT SATELLITE IMAGERY INDICATES SOME
AREAS OF CLEARING ACROSS THE PENINSULA WHICH MAY ALLOW SUFFICIENT
DAY TIME HEATING TO INITIATE CONVECTION. BUT BEST CHANCES OF
CONVECTION IS PROBABLY STILL THE EASTERN HALF OF THE PENINSULA AND
THE ADJACENT ATLANTIC WATERS.
60
PREV DISCUSSION... /ISSUED 741 AM EDT THU MAY 17 2012/
AVIATION...VFR WILL PREVAIL WITH EXTENSIVE MID/HIGH LEVEL
CLOUDINESS BEHIND DEPARTING CONVECTION NOW OVER THE ATLANTIC.
IT WILL TAKE TIME FOR THE AIRMASS TO RECOVER, AND HRRR ACTUALLY
DOES NOT SHOW CONVECTION ON THE EAST COAST UNTIL NEAR KPBI BY 4
PM. IT DOES DEVELOP A BROKEN LINE OF CONVECTION LATE THIS
AFTERNOON FROM JUST NORTH OF LAKE OKEECHOBEE TO ACROSS LEE COUNTY
BEFORE MOVING SLOWLY SE INTO THE AREA. THIS LATE START TO
CONVECTION LOOKS REASONABLE, SO HAVE TEMPO TSRA/MVFR FROM 19-23Z
FOR ALL EAST COAST TERMINALS AND VCTS FOR KAPF. MAY NEED TO ADD
TEMPO THERE SHOULD A BROKEN LINE OF CONVECTION DEVELOP SO WILL
MONITOR TRENDS. ANY STORM LATE THIS AFTERNOON/EVENING WILL BE
CAPABLE OF PRODUCING BRIEF IFR CONDITIONS ALONG WITH STRONG WIND
GUSTS. /GREGORIA
PREV DISCUSSION... /ISSUED 330 AM EDT THU MAY 17 2012/
DISCUSSION...S FLA HAS BEEN UNDER THE INFLUENCE OF THE UPPER TROUGH
OVER THE E U.S. COAST THAT CURRENTLY EXTENDS SW ACROSS THE SE U.S.
INTO THE GULF OF MEX. TODAY AND INTO THE WEEKEND...A CLOSED LOW WILL
DEVELOP OVER THE SE U.S./ADJACENT ATLC AND WILL PERSIST THROUGH THE
WEEKEND INTO EARLY NEXT WEEK DUE TO THE DEVELOPMENT OF A REX BLOCK
AS A STRONG UPPER RIDGE EXTENDS NW OVER NEW ENGLAND FROM THE ALTC
HIGH. THIS STOPS THE MOVEMENT OF THE UPPER LOW. BY MIDWEEK NEXT
WEEK...LONG RANGE MODELS DIFFER SOME ON THE SCENARIO...BUT A DEEP
UPPER TROUGH OVER THE WESTERN U.S. MOVES E WHICH PULLS THE CLOSED
LOW N AND ABSORBING THE FORMER SYSTEM. THE GFS INDICATES MULTIPLE
SMALL UPPER TROUGHS THAT MAY CROSS FLA WITH THE ECMWF INDICATING A
WESTERLY FLOW ALOFT WHICH MAY BRING MINIMAL SHORT WAVES ACROSS THE
AREA.
SHORT TERM...(TODAY-SATURDAY)...TODAY COULD BE MORE ACTIVE THAN
THURSDAY. A 500 MB 40 KT WIND AXIS MOVES NE ACROSS S CENTRAL FLA
WITH S FLA IN THE RFQ WITH SOME SPEED DIVERGENCE. WITH E/W COAST SEA
BREEZES DEVELOPING ALONG WITH THE AMPLE POSSIBILITY OF MORE
INSOLATION...VERY HIGH POPS WITH NUMEROUS TO WIDESPREAD
SHOWERS/THUNDERSTORMS POSSIBLE INTERIOR AND E. THERE WILL BE MAINLY
EVENING SHOWERS/THUNDERSTORMS E THIS EVENING BUT WITH THE MOIST
SW FLOW...ACTIVITY WILL STILL MOVE FROM THE GULF ACROSS THE
PENINSULA. POPS DIFFER BETWEEN MODELS FRIDAY BUT THE SURFACE
TROUGH...WHICH IS A REFLECTION OF THE UPPER TROUGH TO THE
NW...REMAINS NW OF S FLA AND S FLA REMAINS UNDER THE VERY MOIST
REGIME LIKE TODAY. THUS...WILL GO ABOVE MAV POPS. FRIDAY NIGHT A
SW FLOW ALOFT REMAINS BUT WITH THE SURFACE TROUGH DRAGGING
THROUGH...POPS LOWER. ON SATURDAY...SOME DRYING OCCURS.
EXTENDED PERIOD...(SUNDAY-WEDNESDAY)...AS MENTIONED ABOVE...THE
LONG RANGE PATTERN VARIES PER MODEL AND SOME DECREASE IN CONFIDENCE
OF THE POSSIBILITIES EXISTS. WITH THE SW UPPER FLOW PROJECTED TO
PERSIST...SOME RIPPLES MOVING THROUGH AND WITH VARIATION ON MODEL
PRECIPITATION FORECAST...WILL FOLLOW MEX GUIDANCE BUT EXPECT MORE
ACTIVITY IN THE INTERIOR AND NE THROUGH THE PERIOD AS THE LOW LEVEL
EASTERLY FLOW EXPECTED SHUNTING PRECIPITATION A BIT TO THE N.
MARINE...
WINDS GENERALLY LESS THAN 10 KNOTS WITH AND SEAS 3 FEET OR LESS. THE
MAIN PROBLEMS WILL BE THE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS.
FIRE WEATHER...
AMPLE RAIN AND HIGH HUMIDITY EQUAL NO PROBLEMS TODAY AND THROUGH THE
WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 72 86 72 / 70 50 50 40
FORT LAUDERDALE 85 74 87 75 / 70 50 50 40
MIAMI 85 73 88 74 / 70 50 50 40
NAPLES 83 71 85 70 / 50 50 50 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
113 PM EDT THU MAY 17 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 140 AM EDT THU MAY 17 2012
HIGH PRESSURE OVER THE APPALACHIANS WILL DOMINATE INDIANA WEATHER
THROUGH THE WEEKEND. A COLD FRONT IS FORECAST TO APPROACH AND THEN
CROSS THE HOOSIER STATE MONDAY AND TUESDAY. AFTER THAT...HIGH
PRESSURE SHOULD RETURN FROM THE WEST.
&&
.NEAR TERM /TODAY/...
ISSUED AT 1010 AM EDT THU MAY 17 2012
NO SIGNIFICANT CHANGES NEEDED AT THIS TIME. MADE SOME CHANGES TO
THE DEWPOINT GRIDS TO LOWER THEM ACROSS THE SOUTH AS SOME DRY
ADVECTION OCCURRING. PREVIOUS FORECAST HAD LEANED TOWARDS WARMER MAV
AND THIS SEEMS REASONABLE GIVEN THERE WILL BE FULL SUNSHINE TODAY.
THE RUC MODEL SOUNDINGS WERE A LITTLE WARMER WHILE THE 00Z NAM
SOUNDINGS WERE A LITTLE COOLER. MADE A FEW MINOR TWEAKS TO
TEMPERATURE GRIDS MAINLY TO LOWER THEM A DEGREE IN THE EAST.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 140 AM EDT THU MAY 17 2012
ALL MODELS CLOSE..BUT NAM IS A MINOR OUTLIER COMPARED TO NEARLY
IDENTICAL SREF AND GFS. WITH GFS LOOKING A LITTLE BETTER WILL USE
THAT AS UNDERLYING MODEL.
THIS DOES NOT MAKE MUCH DIFFERENCE SINCE ALL MODELS CALLING FOR
MOSTLY CLEAR THROUGH SATURDAY AND MET AND MAV ARE CLOSE ON TEMPS.
USING MAV WHEN ANY DIFFERENCE FROM MET BECAUSE FAVOR GFS AND MAV
HAD LONGER DEVELOPMENT CYCLE.
PRECIP NOT ABSOLUTELY OUT OF QUESTION SATURDAY NIGHT IN WARM
ADVECTION. HOWEVER POSSIBILITY IS MARGINAL AT MOST AND WILL
CONTINUE WITH DRY FORECAST FOR NOW.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 220 AM EDT THU MAY 17 2012
MAIN FOCUS ON THE LONG TERM WILL BE TIMING OF THUNDERSTORM CHANCES
BACK TO CENTRAL INDIANA ALONG WITH TEMPERATURES AS A COLD FRONT
APPROACHES LATE IN THE WEEKEND AND EARLY NEXT WEEK.
THE 00Z GEM IS NOW LEANING SLOWER WITH A COLD FRONT LATE THIS
WEEKEND AND EARLY NEXT WEEK PER THE 12Z ECMWF AND EURO TRENDS AND AS
OPPOSED TO THE FASTER 00Z GFS AND GFS TRENDS. THIS WOULD FAVOR
HOLDING OFF POPS INTIL SUNDAY NIGHT ACROSS THE WEST AND ACROSS ALL
OF CENTRAL INDIANA BY MONDAY. THE FRONT AND ASSOCIATED CONVECTION
ARE EXPECTED TO RESULT IN NOT AS WARM TEMPERATURES BY MONDAY WITH
REASONABLE CR INIT HIGHS ONLY IN THE 70S BY TUESDAY WITH 80S SUNDAY
AND MONDAY AHEAD OF THE FRONT. INSTABILITY PROGS SUGGEST PLENTY OF
INSTABILITY THROUGH THE PERIOD FOR THUNDERSTORM MENTION.
&&
.AVIATION /DISCUSSION FOR THE 17/1800Z TAF ISSUANCE/...
ISSUED AT 104 PM EDT THU MAY 17 2012
VFR CONDITIONS EXPECTED FOR ENTIRE TAF PERIOD WITH HIGH PRESSURE
STILL IN CONTROL OVER TAF SITES. WILL NOT INSERT ANY FOG FOR
TONIGHT...MODELS ARE NOT INDICATING ANY FORMATION. WINDS WILL BE
EASTERLY AT 4 TO 8 KTS THROUGH THIS EVENING...AND WILL THEN
DECREASE TO 2 TO 4 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JH
LONG TERM....MK
AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1244 PM EDT THU MAY 17 2012
.Forecast Update...
Issued at 1135 AM EDT May 17 2012
The clouds that were moving in from the northeast earlier this
morning dissipated right on schedule, leaving us with mostly sunny
skies by 15Z.
Surface dew points have been increasing and pooling over southern
Kentucky this morning. HRRR has been trending much more bullish
with convection in the south this afternoon. After coordination
with neighboring offices, and considering the afternoon development
we saw over the past two days, have decided to go ahead and throw in
a SLGT CHC of showers/storms during peak heating this afternoon in
the south. Will restrict PoPs to the south of where the 1000 foot
overcast was earlier.
Issued at 830 AM EDT May 17 2012
This update primarily dealt with a 1000 foot overcast that developed
over the southern Blue Grass. It appears that the clouds should mix
out by 15Z, but in the meantime we have significantly increased
cloudcover in and near that patch of clouds.
A shower managed to pop up over Hart County between 11Z and 12Z but
it has since fallen apart. Munfordville web cam did show some
elevated instability revealed in the cumuliform cloud structures
overhead...as also seen on visible satellite channel. A rogue
shower will still be possible in southeastern sections of the LMK
CWA near a diffuse cold front, but coverage should remain minimal.
Went ahead an increased PoPs to a silent 13% southeast of a BWG-LEX
line.
.Short Term (Today through Friday)...
Issued at 308 AM EDT May 17 2012
The weak frontal boundary that brought scattered showers/storms to
the region last evening has stalled across south-central KY early
this morning. South of this boundary, winds are calm and dewpoints
are still in the upper 50s. With this moist air in place, light
ground fog will again be possible towards dawn, mainly over lakes or
low-lying areas or river valleys. North of the boundary however,
winds are out of the northeast with dewpoints dropping into the
upper 40s. Even further north, a secondary dewpoint boundary across
southern IN has upper 30 dewpoints behind it. Needless to say, high
pressure over the Great Lakes is on the way. This surface high will
push south and bring drier air into the region through the
short-term period. Only hang up will be added cloud cover near the
stalled boundary across the TN/KY border. Think this boundary will
eventually push south into TN today, so precip should remain south
of our CWA with dry weather forecast.
With clear skies for the most part today, think we`ll be able to
reach the upper 70s northeast into the lower 80s southwest. With
high pressure continuing on Friday and even more dry air in place,
good mixing and veering winds will allow for temps to climb even
higher, with low to mid 80s being the rule under sunny skies again.
Lows tonight will drop into the low to mid 50s with no fog expected.
.Long Term (Friday Night through Wednesday)...
Issued at 250 AM EDT May 17 2012
A mostly dry and quite warm weekend is setting up for the region as
we remain under the influence of surface high pressure and an upper
level ridge. Regarding precip chances Saturday and Sunday afternoon,
there is still a lot of uncertainty as to whether any storms will
be able to develop. The GFS continues to develop some precip, though
it now paints the best chance on Sunday across the entire are, with
less on Saturday. The ECMWF remains dry and we will continue to
advertise a dry solution for now, though pops may be needed at some
point in time. With southerly winds and mostly sunny skies under the
high pressure, temperatures will be quite warm this weekend. Highs
will top out in the mid to upper 80s with lows in the lower 60s.
A front will begin to approach the region on Monday and move through
Monday night into Tuesday. Isolated to scattered thunderstorms will
develop ahead of this front on Monday. Storm coverage will increase
Monday night and Tuesday as the front passes through the area.
Beyond Tuesday the forecast is a bit less certain. The GFS is much
faster than the ECMWF at clearing things out behind the front as the
ECMWF is slower to move out an upper level low. There is quite a bit
of spread in the ensembles on precip chances for Wednesday, so will
carry a slight chance of shower/storms for now. With increased
cloud/precip coverage Monday through Wednesday, high temperatures
will be a bit cooler, in the upper 70s to lower 80s. Lows will
continue to drop into the lower 60s.
&&
.Aviation (18Z TAF Issuance)...
Updated at 1244 PM EDT May 17 2012
High pressure moving by to the north will keep our skies mostly
clear through the TAF period. A stray storm or two may pop up
around BWG this afternoon but chances of the airport getting hit are
very slim at this point.
BWG avoided any sub-VFR fog this morning, and it appears that will
be the case again Friday morning.
Northeast breezes today will go calm tonight and veer slightly to
the east and southeast tomorrow though they will remain light.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........13
Short Term.......AL
Long Term........EER
Aviation.........13
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
358 PM EDT THU MAY 17 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE NORTHEASTERN STATES WHILE LOW
PRESSURE MOVES SLOWLY NORTH OFF THE CAROLINA COAST THROUGH THE
WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY/...
THE COLD FRONT HAS PUSHED TO SOUTH INTO THE CAROLINAS AS SURFACE
HIGH PRESSURE OVER THE EASTERN GREAT LAKES BEGINS TO INFLUENCE THE
REGION. UPPER LEVEL LOW PRESSURE WAS SPINNING OVER EASTERN GEORGIA.
NORTHEAST WINDS HAVE KEPT CLOUDS (BASES 1 TO 3K FT) OVER PORTIONS OF
SE VIRGINIA AND NE NORTH CAROLINA. SHOWERS APPEAR TO HAVE ENDED OVER
OUR AREA AS DRIER AIR MOVES IN ALOFT.
WILL KEEP CONSIDERABLE CLOUDINESS OVER FAR SOUTHEAST PORTIONS AND
THE REST OF THE AREA WILL GRADUALLY CLEAR. LOW TEMPERATURES WILL
RANGE FROM AROUND 50 OVER THE MD LOWER EASTERN SHORE AND THE
NORTHERN PIEDMONT TO NEAR 60 ON THE SRN VA/NC COAST.
HIGH PRESSURE REMAINS ANCHORED ACROSS THE NORTHEAST U.S. ON FRIDAY.
MEANWHILE...THE AFOREMENTIONED COLD FRONT STALLS OFF THE SOUTHEAST
COAST. LOW PRESSURE FORMS ALONG THIS FRONTAL BOUNDARY OVER THE
WESTERN ATLANTIC. THE COMBINATION OF HIGH PRESSURE TO THE NORTH AND
LOW PRESSURE OFF THE COAST WILL RESULT IN PERSISTENT ONSHORE FLOW.
THIS WILL MAINTAIN PLEASANT HIGH TEMPERATURES WITH READINGS RANGING
FROM THE LOW 70S ALONG THE COAST TO THE UPPER 70S OVER THE PIEDMONT.
ON FRIDAY...SKIES WILL BE MOSTLY CLEAR WELL INLAND BUT MOSTLY CLOUDY
ACROSS SOUTHEAST VA AND NORTHEAST NORTH CAROLINA. THERE WILL BE A
SLIGHT CHANCE FOR RAIN OVER A SMALL PORTION OF OUR NORTH CAROLINA
COUNTIES NEAR THE COAST..
HIGH TEMPERATURES WILL RANGE FROM THE MID TO UPPER 60S NEAR THE
COAST TO THE MID TO UPPER 70S WELL INLAND.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
UNCERTAINTY CONTINUES FOR THE UPCOMING WEEKEND DUE TO QUESTIONS
SURROUNDING THE PROGRESS OF THE SYSTEM IN THE SOUTHEAST. SOME
GUIDANCE RETROGRADES THE LOW TO THE WEST OVER THE CAROLINAS AND THEN
DISSIPATES. THIS SOLUTION WOULD BRING WET WEATHER TO THE AREA THIS
WEEKEND. IT DOESN`T APPEAR THAT BLOCKING TO THE NORTH WOULD BE
STRONG ENOUGH FOR THIS TO OCCUR.
HPC PREFERS THE TREND OF THE EURO AND GFS WITH KEEPING THE LOW
OFFSHORE AND THUS A RELATIVELY DRY SOLUTION FOR THE MID ATLANTIC
STATES. THE EURO SEEMS TO BE FAIRLY CONSISTENT AND APPEARS RIGHT NOW
TO HAVE THE BEST HANDLE ON IT.
THE RESULT IS SLIGHT CHANCE OF RAIN NEAR THE NORTH CAROLINA COAST
FRIDAY NIGHT INCREASING TO A 30 PERCENT CHANCE OF RAIN BY SATURDAY
NIGHT. SLIGHT CHANCE POPS SPREADS INTO SOUTHEAST VIRGINIA BY
SATURDAY NIGHT AND TO OUR ENTIRE AREA ON SUNDAY. IN SUMMARY...MOST
OF THE AREA IS FORECAST TO BE DRY THIS WEEKEND. RESIDENTS ESPECIALLY
NEAR THE COAST SHOULD CONTINUE TO MONITOR THE LATEST FORECAST FOR
UPDATES.
GENERALLY DID A BLEND OF NAM AND MAV GUIDANCE AND BLENDED IT WITH
MOS GUIDE FOR TEMPERATURES. THERE IS A SIGNIFICANT DIFFERENCE WITH
HIGH TEMPERATURES SATURDAY BETWEEN THE MET AND MAV DUE TO A
VARIATION IN FORECAST CLOUD COVER (THE MAV BEING 10 OR MORE DEGREES
WARMER THAN THE MET ACROSS INLAND AREAS.
HIGH TEMPERATURES SATURDAY AND SUNDAY ARE FORECAST TO BE IN THE 70S
EXCEPT UPPER 60S NEAR THE COAST (POSSIBLY COOLER IF RAIN DEVELOPS).
LOWS IN THE MID TO UPPER 40S WEST OF INTERSTATE 95 SATURDAY MORNING
(DUE TO MOSTLY CLEAR SKIES) WILL RANGE TO THE MID 50S TOWARD THE
COAST. LOWS SUNDAY MORNING ARE FORECAST TO BE IN THE 50S ACROSS THE
AREA.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
BROAD UPR-LVL TROF REMAINS IN PLACE OVR THE EASTERN SEABOARD INTO
ERLY NEXT WEEK LEADING TO A TRICKY FORECAST SCENARIO. VARIOUS
SHORTWAVES PIVOTING AROUND THE TROF WILL LEAD TO SFC LOW DEVELOPMENT
OFFSHORE...WITH MODELS CONTINUING TO DIFFER ON THE TIMING AND
STRENGTH OF THESE SFC LOWS. 12Z ECMWF BRINGS A LOW UP THE EASTERN
SEABOARD MON INTO TUE LEADING TO A BETTER CHC FOR RAIN (ESPECIALLY
OVR EASTERN AREAS) THAN THE 12Z GFS WHICH STALLS THE SFC LOW NEAR
THE SOUTH CAROLINA COAST MON AND TUE. WILL CAP POPS AT 30% FOR NOW.
THE BROAD UPR-LVL TROF WILL BE REINFORCED INTO THE MIDDLE OF NEXT
WEEK AS PLENTY OF ENERGY SLIDES DOWN THE WESTERN HALF OF THE TROF
FROM THE RIDGE OVR THE HIGH PLAINS. SO WILL MAINTAIN SLGT CHC TO CHC
POPS FOR THE REMAINDER OF THE LONG TERM PERIOD. TEMPS WILL BE
SEASONABLE...HIGHS GENERALLY IN THE UPR 70S TO LWR 80S.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
COLD FRONT HAS MOVED SOUTH OF THE AREA EARLY THIS AFTERNOON. CAN
SEE ON VWP THAT WINDS HAVE SHIFTED TO NE THRU AT LEAST 7 THOUSAND
FEET. THIS IS BRINGING SOME MOISTURE FROM OFF THE ATLANTIC AND
WITH COOLING TEMPERATURES GETTING SOME CLOUD FORMATION GENERALLY
AROUND 2 THOUSAND FEET. THIS IS WELL DEPICTED BY RH AT 925 MB ON
THE RAP MODEL. WILL USE THE TIMING FROM THE RAP TO SCATTERED THE
CLOUDS FROM NORTH TO SOUTH AROUND SUNRISE. SBY ALREADY HAS DRY AIR
COMING IN AND THIS IS KEEPING CLOUDS SCATTERED THERE.
MODELS ALL HAVE DIFFERING SOLUTIONS WITH CUTOFF LOW TO THE SOUTH
OF THE AREA AND THIS IMPACTS MOISTURE FEED OFF THE ATLANTIC. THE
NAM BRINGS LOW CLOUDS BACK AS EARLY AS FRIDAY MORNING BUT NONE OF
THE OTHER MODELS DO. WHILE FEEL WITH FLOW OFF THE WATER COULD HAVE
AT LEAST SOME SCATTERED CLOUDS SO WENT AROUND 3 THOUSAND SCATTERED.
AS THE WEEKEND PROGRESSES MORE MOISTURE WILL COME IN FROM THE
ATLANTIC AND CEILINGS WILL BECOME MVFR AND POTENTIALLY DOWN TO IFR
BY LATE IN THE WEEKEND. WITH DIFFERENT TIMINGS FROM THE MODELS
THERE IS STILL A LOT OF UNCERTAINTY ON THE TIMING OF THESE CONDITIONS.
&&
.MARINE...
HI PRES WILL CONTINUE TO BLD OVR THE MID ATLANTIC THIS EVNG
FOLLOWING THE COLD FROPA EARLIER TDY. THIS WILL LEAD TO PERSISTENT
ONSHORE FLOW AND INCREASING EASTERLY SWELL CAUSING 5 FT SEAS OVR
COASTAL WATERS OVRNGT. SCA HEADLINES ALSO IN EFFECT OVR THE
BAY/SOUND/LWR JAMES RIVER WHERE NE WNDS WILL INCREASE OVRNGT. DUE
TO UNCERTAINTY REGARDING START TIME OF REACHING SCA WNDS...THESE
WNDS EXPECTED WITHIN 12 HR...AND HEADLINES ALREADY IN
PLACE...DECIDED TO PUT THE SCA INTO EFFECT WITH THIS FORECAST
PACKAGE. OTHER THREE MARINE ZONES (OVR THE RIVERS) MAY NEED TO BE
INCLUDED AS WELL AT SOME POINT. NE WNDS INCREASE FRI AND FRI NGT AS
LO PRES MOVES UP THE SE COAST WHILE HI PRES HOLDS STEADY OVR THE
NE...LEADING TO A TIGHTENING PRES GRADIENT. FAVORED SREF/ECMWF
REGARDING WND DIRECTION WITH THIS SYSTM. WILL END THE HEADLINES
UP FOR WNDS SAT MRNG DUE TO UNCERTAINTY REGARDING THE TRACK OF THE
LOW PRES SYSTM. SEAS EXPECTED TO STAY AOA 5 FT THRU THE DAY SAT.
&&
.EQUIPMENT...
ASOS OBSERVATION FOR PHF IS NOT AVAILABLE ONLINE DUE TO COMMS
ISSUE. THE PROBLEM IS BEING WORKED ON AND RTS IS NOT KNOWN AT THIS
TIME.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT SATURDAY FOR ANZ630>634-
638.
SMALL CRAFT ADVISORY UNTIL 7 PM EDT SATURDAY FOR ANZ650-652-
654-656-658.
&&
$$
SYNOPSIS...LSA
NEAR TERM...LSA
SHORT TERM...LSA
LONG TERM...MAS
AVIATION...JAB
MARINE...MAS
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
145 PM EDT THU MAY 17 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE GREAT LAKES BUILDS IN FROM THE NORTHWEST
TODAY BEHIND A COLD FRONT AND BECOMES ANCHORED OVER THE NORTHEAST
FROM FRIDAY THROUGH THE WEEKEND. MEANWHILE...THE COLD FRONT STALLS
OFF THE SOUTHEAST COAST. LOW PRESSURE DEVELOPS ALONG THIS FRONT AND
MEANDERS OVER THE WESTERN ATLANTIC THROUGH THE WEEKEND WITH MUCH
UNCERTAINTY WITH RESPECT TO THE EVENTUAL TRACK OF THE SYSTEM.
&&
.NEAR TERM /THROUGH FRIDAY/...
EARLY AFTN UPDATE INCREASED CLOUD COVER FOR TODAY AS WIDESPREAD
CUMULUS HAS FORMED. HIGH CLOUDS ARE ALSO CONTRIBUTING TO THE CLOUD
COVER. ALSO INCLUDED SLGT CHC THUNDER IN PORTIONS OF THE NORTH
CAROLINA COUNTIES.
ONSHORE WINDS ARE KEEPING SURFACE DEW POINTS RATHER HIGH IN THE
SOUTHEAST AND MOST INLAND AREAS HAVE READINGS IN THE UPPER 50S TO
LOWER 60S. THIS IS RESULTING IN A LOW LCL OF 15 TO 25 HUNDRED FEET
(THUS THE CUMULUS) ACRS SRN AND EASTERN SECTIONS OF THE CWA.
THE HIGHER DEW POINTS ARE HELPING TO PRODUCE WIDELY SCATTERED
CONVECTIVE SHOWERS AND ISOLATED TSTMS OVER PORTIONS OF THE NORTH
CAROLINA COUNTIES. DRYING ALOFT SHOULD KEEP ANY TSTMS TO A MINIMUM
AND ARE EXPECTED TO END BY 20Z.
THE COLD FRONT HAS PUSHED SOUTH OF THE AREA AS OF 14Z. DEW POINTS
ARE STILL IN THE 60S TO AROUND 70 OVER MOST OF THE AREA BUT SHOULD
FALL INTO THE UPR 40S TO LWR 50S OVER NORTHERN SECTIONS BY THIS
AFTN.
CLOUDS WILL KEEP HIGH TEMPERATURES GENERALLY IN THE 70S WITH
ONSHORE FLOW HOLDING AFTERNOON TEMPERATURES NEAR THE COAST IN THE
UPPER 60S. WARMEST READINGS WILL BE IN THE MID TO UPR 70S.
FROM PREVIOUS DISCUSSION... HIGH PRESSURE SHOULD CONTINUE TO
PREVAIL TONIGHT. THE SKY SHOULD RANGE FROM MOSTLY CLEAR OVER MOST
OF THE AREA TO PARTLY CLOUDY OVER COASTAL NE NC. LOW TEMPERATURES
ARE EXPECTED TO RANGE FROM THE UPPER 40S N...TO THE MID TO UPPER
50S OVER EXTREME SE VA AND COASTAL NE NC.
HIGH PRESSURE REMAINS ANCHORED ACROSS THE NORTHEAST US ON FRIDAY.
MEANWHILE...THE AFOREMENTIONED COLD FRONT STALLS OFF THE SOUTHEAST
COAST. LOW PRESSURE FORMS ALONG THIS FRONTAL BOUNDARY OVER THE
WESTERN ATLANTIC. THE COMBINATION OF HIGH PRESSURE TO THE NORTH AND
LOW PRESSURE OFF THE COAST WILL RESULT IN PERSISTENT ONSHORE FLOW.
THIS WILL MAINTAIN PLEASANT HIGH TEMPERATURES WITH READINGS RANGING
FROM THE LOW 70S ALONG THE COAST TO THE UPPER 70S OVER THE PIEDMONT.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
THERE IS MUCH UNCERTAINTY FOR THE UPCOMING WEEKEND. INDIVIDUAL MODEL
SOLUTIONS HAVE LARGELY BEEN CONSISTENT FROM RUN-TO-RUN...BUT
INCONSISTENT AMONGST EACH OTHER WITH RESPECT TO THE EVENTUAL TRACK
OF THE AFOREMENTIONED AREA OF LOW PRESSURE OFF THE WESTERN ATLANTIC.
THE NAM AND GEM GLOBAL MOVE THE LOW PRESSURE SYSTEM NORTHWARD OFF
THE OUTER BANKS BEFORE RETROGRADING IT WESTWARD INTO THE MID
ATLANTIC OVER THE WEEKEND. THIS WOULD LEAD TO WET CONDITIONS
ESPECIALLY ALONG THE COAST. THE ECMWF IS SLOWER WITH WITH ANY
MOISTURE NOT ARRIVING UNTIL LATER IN THE WEEKEND AND EARLY NEXT
WEEK. MEANWHILE...THE GFS IS MOST OPTIMISTIC WITH HIGH PRESSURE
PREVAILING THROUGH THE WEEKEND. ADDITIONALLY THE SREF MEAN IS MORE
IN LINE WITH THE NAM/GEM. CHANCE POPS WILL BE FORECAST FOR SE
COASTAL LOCATIONS THROUGH THE WEEKEND ALONG WITH INCREASED SKY COVER
MAINLY ALONG THE COAST. ONSHORE FLOW WILL KEEP HIGHS IN THE
70S...BUT IF RAIN DOES MOVE OVER THE COAST HIGHS WILL BE COOLER.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
BROAD UPR-LVL TROF REMAINS IN PLACE OVR THE EASTERN SEABOARD INTO
ERLY NEXT WEEK SO WILL KEEP SLGT CHC/LOW CHC POPS IN THE FORECAST.
HIGH TEMPERATURES APPEAR TO WARM INTO THE LOW 80S BY THE MIDDLE OF
NEXT WEEK.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
COLD FRONT HAS MOVED SOUTH OF THE AREA EARLY THIS AFTERNOON. CAN
SEE ON VWP THAT WINDS HAVE SHIFTED TO NE THRU AT LEAST 7 THOUSAND
FEET. THIS IS BRINGING SOME MOISTURE FROM OFF THE ATLANTIC AND
WITH COOLING TEMPERATURES GETTING SOME CLOUD FORMATION GENERALLY
AROUND 2 THOUSAND FEET. THIS IS WELL DEPICTED BY RH AT 925 MB ON
THE RAP MODEL. WILL USE THE TIMING FROM THE RAP TO SCATTERED THE
CLOUDS FROM NORTH TO SOUTH AROUND SUNRISE. SBY ALREADY HAS DRY AIR
COMING IN AND THIS IS KEEPING CLOUDS SCATTERED THERE.
MODELS ALL HAVE DIFFERING SOLUTIONS WITH CUTOFF LOW TO THE SOUTH
OF THE AREA AND THIS IMPACTS MOISTURE FEED OFF THE ATLANTIC. THE
NAM BRINGS LOW CLOUDS BACK AS EARLY AS FRIDAY MORNING BUT NONE OF
THE OTHER MODELS DO. WHILE FEEL WITH FLOW OFF THE WATER COULD HAVE
AT LEAST SOME SCATTERED CLOUDS SO WENT AROUND 3 THOUSAND SCATTERED.
AS THE WEEKEND PROGRESSES MORE MOISTURE WILL COME IN FROM THE
ATLANTIC AND CEILINGS WILL BECOME MVFR AND POTENTIALLY DOWN TO IFR
BY LATE IN THE WEEKEND. WITH DIFFERENT TIMINGS FROM THE MODELS
THERE IS STILL A LOT OF UNCERTAINTY ON THE TIMING OF THESE CONDITIONS.
&&
.MARINE...
COLD FRONT HAS NOW PUSHED SOUTH OF THE AREA. WITH THE LOW LEVEL
FLOW COMING OUT OF THE NE AND TEMPERATURES COOLING GETTING A DECK
OF CLOUDS BETWEEN 2 AND 3 THOUSAND FEET OVER MUCH OF THE AREA.
THIS IS COLD FRNT WILL PUSH THRU THE MARINE AREA FM N TO S THRU
THIS MORNG...WITH LGT SSW WNDS SHIFTING TO THE NNE AND INCREASING
TO 15 TO 20 KT. WILL HAVE SCA FOR THE CHES BAY DURING TDY...THEN
HAVE SCA FOR THE SRN TWO CHES BAY ZNS...CURRITUCK SND...AND ALL
THE CSTL ZNS FM LATE THIS AFTN THRU LATE FRI NGT...AS NE WNDS 15
TO ARND 20 KT PRODUCES WAVES 3 TO 4 FT IN THE SRN CHES BAY...AND
SEAS 5 TO 6 FT OVR THE CSTL ZNS. THIS NE FLO WILL RESULT FM HI
PRES BLDNG BY TO THE N AND LO PRES LINGERING OFF THE MID ATLC CST.
&&
.EQUIPMENT...
ASOS OBSERVATION FOR PHF IS NOT AVAILABLE ONLINE DUE TO COMMS
ISSUE. THE PROBLEM IS BEING WORKED ON AND RTS IS NOT KNOWN AT THIS
TIME.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT SATURDAY FOR ANZ632-634.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT SATURDAY FOR ANZ633-650-
652-654-656-658.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ630-
631.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ/LSA
SHORT TERM...AJZ
LONG TERM...MAS
AVIATION...JAB
MARINE...TMG
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
149 PM EDT THU MAY 17 2012
.SYNOPSIS...
ISSUED AT 512 AM EDT THU MAY 17 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE FROM
THE PLAINS INTO CNTRL CANADA AND A DOWNSTREAM TROUGH FROM QUEBEC
INTO THE NE CONUS RESULTING IN NW FLOW THROUGH THE NRN GREAT LAKES.
AT THE SFC...HIGH PRES WAS CENTERED OVER LOWER MI WHILE LOW PRES WAS
DEVELOPING OVER THE PLAINS FROM SRN SASK INTO WRN SOUTH DAKOTA. MID
LEVEL WARM ADVECTION AHEAD OF A WARM FRONT OVER THE CNTRL PLAINS
SUPPORTED DEVELOPING SHRA AND A FEW TSRA OVER SW MN.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 512 AM EDT THU MAY 17 2012
TODAY...EXPECT THE BAND OF STRONGER 310K ISENTROPIC LIFT AND
POSITION OF THE 750-650 MB WARM FRONT TO EXPAND TO THE ENE
TODAY...PER NAM/GFS. HOWEVER...SINCE THE PCPN IS MOVING AWAY FROM
THE GREATER LOW LEVEL MOISTURE INTO THE DRY LOW LEVEL AIRMASS TO THE
EAST...PER 00Z MPX/INL/GRB SOUNDINGS...THE PCPN SHOULD REMAIN LIGHT
AND MAINLY TO THE WEST AND SOUTH OF THE CWA. LOCATIONS FROM IWD-IMT
WILL SEE THE BEST CHANCE OF ANY PCPN BUT ONLY SLIGHT CHANCE POPS
WERE INCLUDED WITH ANY PCPN AMOUNTS LESS THAN A TENTH OF AN INCH.
OTHERWISE...WAA WILL HELP PUSH TEMPS INTO THE MID 50S TO LOWER 70S
DESPITE AN INCREASE IN MID HIGH CLOUDS.
TONIGHT...THE FOCUS OF THE LLJ AND STRONGEST MOISTURE TRANSPORT IS
EXPECTED OVER NE MN AND NW WI INTO WRN LAKE SUPERIOR. AREAS OF
SHRA/TSRA SHOULD DEVELOP AND EVENTUALLY SPREAD TO THE EAST AFFECTING
MAINLY THE NW HALF OF THE CWA AS THE LLJ VEERS OVERNIGHT.
HOWEVER...THERE IS STILL SIGNIFICANT UNCERTAINTY WITH THE
TIMING/POSITION OF THE CONVECTION.
FRIDAY...ANY LEFTOVER SHRA/TSRA OVER MAINLY NORTH UPPER MI INTO LAKE
SUPERIOR SHOULD SLIDE TO THE ENE AND DIMINISH DURING THE MORNING AS
THE LLJ WEAKENS. THE COMBINATION OF BUILDING MID-LVL RDG HEIGHTS AND
850 MB WARM FRONT LIFTING WELL NORTH OF THE AREA SHOULD KEEP THE CWA
DRY FRI AFTERNOON. RESIDUAL CLOUDS FROM CONVECTION SHOULD DISSIPATE
FRI AFTERNOON ALLOWING FOR INCREASED SUNSHINE. MIXING OF 850 MB
TEMPS OF AROUND 16C TO THE SFC SHOULD ALLOW FOR HIGH TEMPS FRIDAY TO
REACH INTO THE LOWER 80S OVER WRN INTERIOR LOCATION. COOLER SRLY
FLOW OFF LAKE MI WILL KEEP INLAND HIGHS OVER ERN COUNTIES IN THE LOW
TO MID 70S.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 512 AM EDT THU MAY 17 2012
PERIOD STARTS 00Z SAT WITH A 500MB RIDGE OVER THE CWA...AND A 500MB
TROUGH OVER THE INTERMOUNTAIN WEST. AT THE SFC...994MB LOW PRESSURE
WILL BE STRETCHED E FROM ERN CO TO SRN ND...AND WITH HIGH PRESSURE
SITTING OVER THE ERN SEABOARD...THAT PUTS US UNDER S/SSW FLOW.
THAT/S RIGHT...WE WILL BE IN THE WARM SECTOR AS THE WARM FRONT
ASSOCIATED WITH THE SYSTEM TO OUR W WILL BE N OF LAKE SUPERIOR BY 00Z
SAT. AND WARM IT WILL BE WITH 850MB TEMPS AROUND 17C.
FRI NIGHT AND SAT...SOLID S/SW FLOW IN THE WARM LOW LEVELS WILL KEEP
TEMPS FROM FALLING TOO FAR FRI NIGHT...ESPECIALLY IN DOWNSLOPING
AREAS. HAVE LOW TEMPS AROUND 60 IN THE DOWNSLOPE AREAS...AND IN THE
UPPER 40S TO 50S ELSEWHERE. WITH HIGHER DEW PTS AND WAA...COULD SEE
FOG OVER MAINLY NRN LAKE SUPERIOR AND EVENTUALLY NRN LAKE MI /WHICH
WOULD LAST UNTIL FROPA SUNDAY/...WHICH I ADDED TO THE FORECAST FOR
FRI NIGHT THROUGH SUN. 850MB TEMPS STAY AROUND 17C THROUGH
SAT...WITH GOOD S/SW FLOW CONTINUING...ALLOWING MIXING TO AROUND
800MB. THIS YIELDS HIGH TEMPS IN THE 80S OVER THE W HALF AND NEAR
LAKE SUPERIOR OVER THE E HALF...WITH HIGHS IN THE 60S CLOSE TO NRN
LAKE MI DUE TO S/SSW FLOW OF THE RELATIVELY COLD LAKE. ATMOSPHERE
LOOKS TOO DRY AND TOO CAPPED FOR CONVECTION TO FORM ON SAT...WHICH
IS GOOD SINCE WE SHOULD HAVE 1500-2000J/KG OF CAPE SAT AFTERNOON.
LOWERED DEW PTS A FEW DEGREES AS MIXING WILL ALLOW DRY AIR TO GET TO
THE SFC. THIS LEADS TO MIN RH VALUES DOWN OF 25 TO 35 PERCENT OVER
THE W HALF OF UPPER MI...AND GREATER THAN 35 PERCENT RH OVER THE E
HALF. THIS BECOMES MORE PROBLEMATIC WHEN CONSIDERING WINDS WILL BE
SLY AT 15-20MPH WITH GUSTS OF 25-35MPH. LOOKS LIKE IT MAY BE A
CRITICAL FIRE WEATHER DAY...BUT THAT WILL NEED TO BE LOOKED AT MORE
CLOSELY BY LATER SHIFTS FOR POSSIBLE FIRE WEATHER HEADLINES.
SAT NIGHT THROUGH MON...BY 00Z SUN...THE UPPER TROUGH WILL HAVE MOVED
FARTHER E...WITH A SHORTWAVE TROUGH OVER MANITOBA...AND POSSIBLY
ANOTHER OVER KS/NE. THE SFC LOW WILL HAVE WEAKENED TO 1002MB AS IT
MOVED TO N OF THE MN ARROWHEAD. THIS PUTS THE COLD JUST W OF LAKE
SUPERIOR AT 00Z SUN. SAT NIGHT WILL BE ANOTHER WARM ONE WITH
CONTINUED STRONG LOW LEVEL FLOW AND WARM LOW LEVEL TEMPS. OVERNIGHT
LOWS LOOK TO BE IN THE 50S AND LOW 60S. DIFFERING MODEL SOLUTIONS
BEGIN TO LOWER CONFIDENCE ON EXACT TIMING OF THE COLD FRONT/PRECIP
DUE MAINLY WITH HOW TO HANDLE A SHORTWAVE MOVING AROUND THE MAIN
UPPER TROUGH SAT NIGHT INTO SUN. THE GFS CONTINUES TO BE THE MOST
AGGRESSIVE WITH THE SHORTWAVE...SHOWING IT STRONGER THAN PRETTY MUCH
ANY OTHER MODEL. THIS MEANS THE GFS ALSO BRINGS THE COLD FRONT
THROUGH FASTER THAN OTHER MODELS. FOR THIS REASON...WILL NOT PUT AS
MUCH OF THE GFS INTO THIS FORECAST. WITH THE IDEA THAT THE GFS IS
ABOUT 6 HOURS TOO FAST WITH FROPA...THE FRONT SHOULD MOVE OVER WRN
UPPER MI SUN AFTERNOON...AND MOVE TO ERN UPPER MI BY 12Z MON...NOTE
THE SLOW EASTWARD PROGRESSION OF THE FRONT. SBCAPES OF AROUND
1000-1500J/KG WILL BE POSSIBLE SUN AFTERNOON AHEAD OF THE
FRONT...BUT CONFIDENCE IN THIS IS A BIT LOW RIGHT NOW DUE TO MODEL
TIMING DIFFERENCES AND UNCERTAINTY IN HOW MUCH CLEARING WILL OCCUR
AHEAD OF THE FRONT. 0-6KM BULK SHEAR LOOKS TO BE AROUND
30KTS...SUFFICIENT FOR ORGANIZED CONVECTION. SO...IT LOOKS LIKE SOME
STRONG TO SEVERE STORMS WILL BE A POSSIBILITY SUN
AFTERNOON/EVENING...BUT CONFIDENCE IS STILL LIMITED. THE COLD FRONT
LOOKS TO COMPLETELY CLEAR THE CWA AROUND 18Z MON...AS THE UPPER
TROUGH AND A SFC RIDGE MOVE INTO THE WRN CWA. 850MB TEMPS OF AROUND
7C MON AFTERNOON WILL MAKE FOR COOLER TEMPS IN THE 60S...EXCEPT IN
THE 50S NEAR LAKE SUPERIOR IN THE NLY WINDS.
MON NIGHT THROUGH WED...EXPECT A GRADUAL WARMING TREND AS AN UPPER
RIDGE MOVES OVERHEAD AND SFC RIDGING SLOWLY MOVES TO E OF THE CWA BY
WED AFTERNOON.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 148 PM EDT THU MAY 17 2012
WARM FRONT OVER SOUTHERN MINNESOTA WILL LIFT THROUGH UPPER MICHIGAN
LATE TONIGHT AND INTO LK SUPERIOR AND ONTARIO BY LATE DAY FRIDAY.
MAY SEE SHOWERS AS THE FRONT MOVES THROUGH...BUT AIR MASS OVER UPR
MICHIGAN IS QUITE DRY SO THINK COVERAGE WILL REMAIN SCATTERED. BEST
CHANCE FOR RAIN IS EARLY THIS AFTN AT IWD AND OVERNIGHT TONIGHT AT
CMX. ISOLD TSRA MAY OCCUR TONIGHT AT IWD AND CMX...BUT CONFIDENCE IS
TOO LOW TO PUT INTO FCST. MAIN HAZARD AT ALL TAF SITES TONIGHT IS
LOW LEVEL WIND SHEAR AS SOUTHWEST LOW-LEVEL JET UP TO 45 KTS MOVES
OVER THE AREA. SFC WINDS WILL BE GENERALLY LIGHT AND MAINLY SOUTH OR
SOUTH-SOUTHEAST DIRECTION SO THERE WILL BE SOME DIRECTIONAL SHEAR AS
WELL. ANY LLWS WILL END AROUND SUNRISE FRIDAY. GUSTY SW WINDS WILL
DEVELOP FRIDAY AS MID CLOUDS SCATTER OUT. GIVEN THE DRY AIR OVR THE
REGION...EVEN IF SHRA/TSRA OCCUR...EXPECT VFR CONDITIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EDT THU MAY 17 2012
WINDS ACROSS LAKE SUPERIOR SHOULD REMAIN BELOW 30KTS THROUGH THE
PERIOD. HIGH PRESSURE ACROSS THE UPPER GREAT LAKES WILL SHIFT TO THE
LOWER GREAT LAKES THIS AFTERNOON...BEFORE PUSHING OFF THE MID
ATLANTIC SHORELINE ON FRIDAY INTO SATURDAY. LOW PRESSURE OVER
SOUTHERN SASKATCHEWAN AND THE WESTERN DAKOTAS WILL PUSH ACROSS THE
NORTHERN AND CENTRAL PLAINS TONIGHT THROUGH SATURDAY...BEFORE
SLIDING NORTH INTO ONTARIO SATURDAY. THIS WILL ALLOW A COLD FRONT TO
PUSH ACROSS THE UPPER GREAT LAKES SUNDAY INTO EARLY MONDAY. BEHIND
THE FRONT...HIGH PRESSURE WILL BUILD IN FROM THE CENTRAL AND
NORTHERN PLAINS THROUGH TUESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLA
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
256 PM CDT THU MAY 17 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT...WINDY CONDITIONS HAVE
DEVELOPED ACROSS MUCH OF THE FORECAST AREA TODAY AS DEEP MIXING HAS
BEEN REALIZED ALONG WITH A TIGHTENING PRESSURE GRADIENT IN RESPONSE
TO AN AREA OF SURFACE LOW PRESSURE TO OUR WEST. DO NOT EXPECT THESE
WINDS TO DIMINISH RAPIDLY THROUGH THE LATE AFTERNOON AND EARLY
EVENING HOURS AS PRESSURE GRADIENT WILL BE SLOW TO RELAX AND WINDS
FROM ALOFT WILL NOT DECOUPLE UNTIL AFTER SUNSET...SO WENT AHEAD AN
KEPT WIND ADVISORY GOING UNTIL 02Z THIS EVENING. IN ADDITION TO THE
WINDS...THERE REMAINS A SLIGHT CHANCE FOR A FEW THUNDERSTORMS THIS
EVENING ACROSS THE WESTERN FRINGES OF THE FORECAST AREA...AS FORCING
FROM WELL DEFINED UPPER LEVEL LOW MAY HELP INITIATE A FEW STORMS.
BOTH 12Z HRRR AND WRF HINT AT THIS TYPE OF DEVELOPMENT...BUT
CONFIDENCE NOT HIGH ENOUGH TO INCREASE COVERAGE AS INSTABILITY
REMAINS FAIRLY MARGINAL AND SIGNIFICANT COVERAGE IS NOT EXPECTED. IF
STORMS DO DEVELOP HOWEVER...MAIN THREAT APPEARS TO BE VERY GUSTY
WINDS AND SMALL HAIL.
OVERNIGHT...THE COMBINATION OF A SCT-BKN CIRRUS SHIELD AND CONTINUED
BREEZY SOUTHERLY WINDS SHOULD KEEP TEMPERATURES ELEVATED ABOVE
SEASONAL LEVELS...WITH LOW TEMPERATURES STRUGGLING TO FALL TO NEAR
60 IN MOST LOCATIONS.
WHILE DRY CONDITIONS ARE EXPECTED TO PREVAIL ON FRIDAY...ANOTHER
WINDY DAY APPEARS TO BE IN STORE ACROSS THE REGION AS THE PRESSURE
GRADIENT REMAINS TIGHT ACROSS THE REGION AND ONCE AGAIN GOOD MIXING
IS ANTICIPATED. WHILE A WIND ADVISORY MAY EVENTUALLY BECOME
NECESSARY ACROSS THE EASTERN HALF OF THE FORECAST AREA DURING THE
AFTERNOON HOURS...DECIDED TO HOLD OFF AT THIS POINT AS WE PRESENTLY
ALREADY HAVE AN ADVISORY HIGHLIGHTED FOR TODAY. DID HOWEVER INCLUDE
ADVISORY LEVEL WINDS FOR MUCH OF THE EASTERN HALF OF THE AREA DURING
THE AFTERNOON HOURS TOMORROW IN LATEST GRIDS. IN ADDITION TO
WINDS...EXPECT ANOTHER VERY WARM AFTERNOON FOR MID MAY...AND
INCREASED AFTERNOON TEMPS SEVERAL DEGREES IN RESPONSE TO WARMING 850
MB TEMPS AND A WARM START TO THE DAY ANTICIPATED.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY. THE PRIMARY WEATHER
FEATURES ARE A COLD FRONT THAT WILL TRACK ACROSS THE CWA ON SATURDAY
AND THEN A WESTERN CONUS UPPER TROUGH THAT DEVELOPS BY THE MIDDLE
OF NEXT WEEK.
FRIDAY NIGHT...MOST FORECAST MODELS ARE DRY FOR OUR FORECAST AREA
WITH THE BETTER CHANCE OF SHOWERS AND THUNDERSTORMS LOCATED ACROSS
PORTIONS OF WESTERN AND NORTHERN NEBRASKA. WILL CONTINUE WITH A
SLIGHT CHANCE OF THUNDERSTORMS ACROSS OUR NORTHWEST
ZONES...PRIMARILY NORTHWEST OF A HOLDREGE TO GRAND ISLAND LINE.
SATURDAY...THIS WILL BE OUR BEST CHANCE OF SEEING SHOWERS AND
THUNDERSTORMS WITHIN THE NEXT 5 DAYS...OR AT LEAST THROUGH TUESDAY.
AN UPPER LEVEL SHORT WAVE WILL SLIDE ACROSS THE CENTRAL PLAINS
ACCOMPANIED BY A FAIRLY STRONG SFC COLD FRONT. THE MORNING SHOULD BE
DRY...BUT SHOWERS AND THUNDERSTORMS WILL FORM ALONG AND BEHIND THE
COLD FRONT BY MID TO LATE AFTERNOON. THE COLD FRONT WILL PRIMARILY
TRACK ACROSS OUR CWA DURING THE AFTERNOON HOURS...BUT MAY NOT EXIT
OUR FAR SOUTHEASTERN ZONES UNTIL AROUND OR A BIT AFTER SUNSET. THERE
MAY BE TWO AREAS OF PRECIPITATION ASSOCIATED WITH THIS SYSTEM. THE
FIRST WILL BE AN AREA OF STRATIFORM RAIN SHOWERS WITH GENERAL NON
SEVERE THUNDERSTORMS WELL BEHIND THE FRONT. THE SECOND AREA WILL BE
STRONG TO SEVERE THUNDERSTORMS THAT SHOULD FORM RIGHT ALONG OR VERY
NEAR THE COLD FRONT. INSTABILITY WILL BE RATHER HIGH ALONG THE FRONT
BY LATE AFTERNOON...ALTHOUGH THE WIND SHEAR WILL BE MORE MARGINAL
AND UNIDIRECTIONAL. BULK SHEAR VECTORS ARE ORIENTED RATHER PARALLEL
TO THE SFC COLD FRONT AND THERE SHOULD BE PRETTY GOOD FORCING RIGHT
ALONG THE FRONT. CONSEQUENTLY...THUNDERSTORMS MAY TEND TO BE MORE
LINEAR OR MULTI CELL RATHER THAN DISCRETE SUPERCELLS. THE PRIMARY
THREAT WILL BE LARGE HAIL AND DAMAGING WINDS.
HIGH TEMPERATURES SATURDAY WILL BE A DIFFICULT CALL AND GREATLY
DEPEND ON THE PROGRESSION OF THE COLD FRONT AND CLOUD COVER. WOULD
NOT BE SURPRISED TO SEE A FEW 90S ACROSS SOUTHEAST ZONES...WHILE
NORTHWEST ZONES MAY STALL OUT IN THE UPPER 70S TO AROUND 80 BY EARLY
AFTERNOON. TEMPERATURES MAY EVEN FALL A FEW DEGREES BY EARLY TO MID
AFTERNOON FOR AREAS THAT SEE THE EARLIER FRONTAL PASSAGE.
SUNDAY...GREAT DAY BEHIND THE COLD FRONT WITH DRY WEATHER AND HIGHS
IN THE LOWER TO MID 70S
MONDAY AND TUESDAY...EXPECT DRY WEATHER TO CONTINUE WITH A GRADUAL
MODERATING TREND AS A WEAK UPPER RIDGE MOVES ACROSS AREA. HIGHS
SHOULD CLIMB FROM THE 70S ON MONDAY BACK INTO THE 80S BY TUESDAY.
WEDNESDAY AND THURSDAY...AN UPPER LEVEL TROUGH WILL DEEPEN ACROSS
THE NORTHWESTERN CONUS AND MAY BEGIN TO ENHANCE THE FORCING/LIFT
OVER THE CENTRAL PLAINS. THERE IS STILL A GOOD DEAL OF MODEL
UNCERTAINTY WITH THIS SYSTEM AND HOW IT WILL EVOLVE AND PUSH OUT
INTO THE PLAINS. THERE WILL BE AT LEAST SOME THREAT OF
THUNDERSTORMS ACROSS THE CENTRAL OR NORTHERN PLAINS...BUT DIFFICULT
TO GET INTO SPECIFICS AT THIS TIME GIVEN THE MODEL UNCERTAINTY.
TEMPERATURES ARE MORE LIKELY TO BE ABOVE NORMAL IN THE 80S AHEAD OF
THIS NEXT TROUGH.
&&
.AVIATION...12Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE
NEXT 24 HOURS...WITH LLWS PERSISTING THROUGH 14Z. THE COMBINATION
OF A SHALLOW LOW LEVEL INVERSION AND A STRONG LOW LEVEL JET IS
PROMOTING SIGNIFICANT LLWS STARTING AROUND 300FT AGL. THIS LLWS
SHOULD DIMINISH BY 14Z AS DIABATIC HEATING ALLOWS FOR DEEPER
BOUNDARY LAYER MIXING...THUS RESULTING IN STRONGER WINDS AT THE
SURFACE AND LESS IN THE WAY OF LLWS. STRONG SURFACE WINDS WILL BE
OBSERVED AT THE TERMINAL ONCE THE BOUNDARY LAYER BEGINS TO
DEEPEN...WITH SUSTAINED SOUTHERLY WINDS OF 24KTS...GUSTING TO
AROUND 34KTS...EXPECTED THIS AFTERNOON. SURFACE WINDS WILL THEN
DIMINISH SOMEWHAT BY SUNSET AS DIABATIC HEATING IS LOST AND THE
BOUNDARY LAYER DECOUPLES FROM THE STRONGER WINDS ALOFT. A SIMILAR
SYNOPTIC SETUP MAY PROMOTE WEAK LLWS AGAIN TONIGHT...HOWEVER IT
DOES NOT APPEAR AS THOUGH THE LOW LEVEL JET WILL BE QUITE AS
STRONG TONIGHT AND WILL GO AHEAD AND LEAVE LLWS OUT OF THE TAF FOR
THE TIME BEING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR NEZ060-061-072>074-
082>084.
KS...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR KSZ005-006-017-018.
&&
$$
SHORT...ROSSI
LONG...WESELY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
229 PM EDT THU MAY 17 2012
.SYNOPSIS...
AN UPPER LEVEL LOW WILL FORM OVER SOUTH CAROLINA...AND WILL MOVE TO
THE NORTH CAROLINA COAST...WHERE IT WILL LINGER INTO EARLY NEXT
WEEK. HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND REMAIN THROUGH
MONDAY. A COLD FRONT WILL APPROACH THE AREA FROM THE WEST ON
TUESDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
WATER VAPOR IMAGERY AND THE LATEST RAP MODEL RUN SHOW A NE TO SW
ORIENTED UPPER LOW STRETCHED OVER THE MIDLANDS OF SOUTH
CAROLINA...BACK ACROSS SOUTHEAST GEORGIA. A SPOKE OF PVA ON THE WEST
SIDE OF THE LOW IS HELPING TO ORGANIZE STRONG TO SEVERE CONVECTION
ACROSS THE SOUTHERN PART OF THE UPSTATE. ELSEWHERE...OTHER STORMS
WERE DEVELOPING OVER THE BLUE RIDGE OF NE GA AND SW NC. SOMEWHAT
DRIER AIR HAS PUSHED INTO THE NRN PIEDMONT AND FOOTHILLS OF NE...BUT
AREAS TO THE SOUTH REMAIN QUITE UNSTABLE WITH SB-CAPE VALUES RUNNING
FROM 1500-2000 J/JG. OUR LOCAL WORKSTATION WRF...THE NCEP 4KM WRF
AND THE HRRR ALL AGREE IN DEVELOPING CONVECTION OVER MUCH OF THE
UPSTATE...SOUTHERN NC MTNS AND FOOTHILLS AND NE GA INTO THE EVENING
HOURS. THIS WOULD BE SIMILAR TO WHAT HAPPENED LAST NIGHT. CONFIDENCE
IN THIS DEVELOPMENT IS FAIRLY HIGH...AND POPS WILL BE PUSHED UP TO
50 PERCENT ACROSS THE I-85 CORRIDOR AND UP INTO THE WRN NC FOOTHILLS
FOR THE EVENING HOURS. COOL MID-LEVEL TEMPS AND DRY AIR ALOFT WILL
CONTINUE TO SUPPORT SEVERE WIND AND HAIL EVENTS.
A BACK DOOR COLD FRONT WILL CROSS THE REGION LATE TONIGHT. THE NAM
MIXES DEWPOINTS INTO THE U40S TO L50S ACROSS THE NC FOOTHILLS AND
PIEDMONT AND THE ERN UPSTATE. THIS SHOULD FINALLY END THE THREAT OF
STORMS FOR THESE AREAS. BACK ACROSS THE MOUNTAINS...ESPECIALLY
CLOSER TO THE TN LINE...SCT CONVECTION SHOULD DEVELOP AGAIN TMRW
WHERE LLVL MOISTURE CONVERGENCE WILL BE MAXIMIZED.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AT 1430 EDT THURSDAY...A CLOSED UPPER LOW...PART OF AN EAST COAST
REX ...WILL BE LOCATED NEAR THE NC COAST ON FRIDAY NIGHT AND
SATURDAY. ON SUNDAY THIS FEATURE RETROGRADES SLIGHTLY INLAND. THE
MODELS SHOW DRIER AIR MOVING SW INTO OUR AREA ON THE BACK SIDE OF
THE LOW FRIDAY NIGHT AND SATURDAY....WHILE SOME MOISTURE LINGERS
ALONG THE BLUE RIDGE. ON SATURDAY NIGHT THE NAM SHOWS MOISTURE
SPREADING WEST ACROSS THE INTERSTATE 77 CORRIDOR TO THE NC BLUE
RIDGE...WHILE THE GFS REMAINS RATHER DRY UNTIL SUNDAY NIGHT.
POPS WILL INITIALLY BE QUITE LOW AND FOCUSED ALONG THE BLUE
RIDGE...THEN WILL INCREASE SLIGHTLY FROM THE EAST TOWARD SUNDAY...
BUT REMAINING RATHER LOW AS CONFIDENCE IS LIMITED ON THE AMOUNT AND
TIMING OF MOISTURE ENCROACHMENT FROM THE EAST. TEMPERATURES WILL
GENERALLY BE SLIGHTLY BELLOW NORMAL UNDER THE UPPER LOW HEIGHT
ANOMALY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AT 1430 EDT THURSDAY...A LONGWAVE TROUGH WILL PROGRESS ACROSS THE
EASTERN USA FROM MONDAY THROUGH WEDNESDAY...PROGRESSING OFFSHORE ON
THURSDAY WHEN A LONGWAVE RIDGE AXIS CROSSES THE MS RIVER VALLEY. A
CLOSED UPPER LOW WILL REMAIN NEAR THE CAROLINA COAST ON MONDAY. THIS
LOW FILLS AND DRIFTS NORTHEAST ON TUESDAY. A SHORTWAVE TROUGH DROPS
SOUTHEAST OVER THE SOUTHERN APPALACHIANS LATE TUESDAY...MOVING OFF
TO THE EAST ON WEDNESDAY.
SURFACE HIGH PRESSURE WILL BE OVER OUR ARE ON MONDAY...BETWEEN A
COASTAL LOW AND A COLD FRONT IN THE MS RIVER VALLEY. CONFIDENCE IS
LIMITED ON THE WESTERN EXTENT OF MOISTURE THAT WILL WRAP AROUND THE
COASTAL LOW TOWARD THE SOUTHERN APPALACHIANS...AND THE RESULTANT
POPS. THE COLD FRONT TO OUR WEST REACHES THE SOUTHERN APPALACHIANS
ON TUESDAY WHILE WEAKENING...WITH THE REMAINS OF THE BOUNDARY
SUPPORTING LENDING SUPPORT TO AT LEAST SMALL POPS. WEDNESDAY AND
THURSDAY FIND OUR AREA UNDER WEAK HIGH PRESSURE...BUT THE MODELS
DEPICT SOME AMOUNT OF LINGERING MOISTURE...OSTENSIBLY ASSOCIATED
WITH THE REMAINS OF THE FORMER FRONT. WITH GULF INFLOW EVENTUALLY
SETTING UP TO OUR WEST...SMALL POPS WILL BE MAINTAINED INTO
THURSDAY...ESPECIALLY IN THE WEST. TEMPERATURES WILL BE SLIGHTLY
ABOVE NORMAL IN MINOR HEIGHTS RISES BEHIND THE DEPARTING UPPER LOW.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AT KCLT...STRONG THUNDERSTORMS WILL CONTINUE TO FIRE ABOUT 15 MILES
SOUTH OF THE AIRFIELD...THEN DRIFT SOUTH FROM THERE...OVER THE NEXT
COUPLE HOURS. HOWEVER...THE AIRMASS WILL BECOME MORE UNSTABLE BY
LATE AFTN. MOST OF THE SHORT RANGE MODELS WANT TO DEVELOP TSTMS
AROUND THE AIRFIELD STARTING IN A COUPLE HOURS AND THE NNE TO SSW
ORIENTED BANDS OF CU ACROSS THE REGION WILL LIKELY START TO DEEPEN
INTO CB/S WITH TIME. I/VE HELD ON TO VCSH TO ACCOUNT FOR THIS...BUT
A PERIOD OF TEMPO TSRA WILL PROBABLY NEED TO BE ADDED ONCE
DEVELOPMENT STARTS TO OCCUR FARTHER NORTH.
WINDS WILL REMAIN OUT OF THE NE THIS AFTN...THOUGH OUTFLOW BNDRYS
MAY PLAY HAVOC WITH THE WINDS AT TIMES. MVFR CIGS ARE EXPECTED AFTER
MIDNIGHT AS A BACK DOOR COLD FRONT SURGES THROUGH THE REGION. THE
CIGS ARE EXPECTED TO CLEAR OUT BEFORE SUNRISE HOWEVER.
ELSEWHERE...MUCH LIKE AT KCLT...THE ATMOSPHERE WILL BECOME MORE
UNSTABLE OVER THE UPSTATE...AND TSTMS WILL LIKELY BEGIN TO DEVELOP
ON OUTFLOW BNDRYS FROM STORMS EAST OF THE REGION NOW. THIS PROCESS
WILL TAKE A COUPLE HOURS. VCHS IS IN THE TAFS NOW...BUT A PERIOD OF
TEMPO GROUPS IS A GOOD BET ONCE THE NEW CELLS BEGIN TO FIRE.
CONFIDENCE IN TIMING JUST ISN/T HIGH ENUF TO TEMPO YET. KAVL IS MORE
STABLE...BUT SHRA MAY CONTINUE THERE FOR A GOOD BIT OF THE NIGHT.
WINDS OVER THE UPSTATE WILL GENERALLY BE OUT OF THE EAST THE REST OF
THE AFTN...TURNING NE LATE TONIGHT AS A BACK DOOR FRONT SURGES
THROUGH. A PERIOD OF MVFR CIGS IS EXPECTED TO ACCOMPANY THE FRONT.
OUTLOOK...EXPECT ISOLD LATE DAY SHOWERS AND TSTMS IN THE MTNS FRI
AFTN....THEN DRYING OVER THE WEEKEND. MRNG FOG WILL BE PSBL...ESP
MTN VALLEYS AND NEAR LAKES/RIVERS.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JAT
NEAR TERM...MCAVOY
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...MCAVOY
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
257 PM MDT THU MAY 17 2012
.DISCUSSION...
A BROAD...FLAT LONG WAVE TROF EXTENDS FROM COAST TO COAST THIS
MORNING WITH A SHORT WAVE TROF OVER CO. MODELS ARE IN GOOD
AGREEMENT IN BRINING A STRONGER TROF INLAND FROM THE PAC TO A
POSITION JUST W OF OUR CWA BY 12Z SAT. AIR MASS OVER THE AREA IS
CHARACTERIZED BY VERY STEEP LOW LEVEL LAPSE RATES AND LIMITED
MOISTURE. A FEW TSTMS HAVE DVLPD THIS AFTN MAINLY OVER THE HIER
TERRAIN OF THE BLACK HILLS WITH A FEW SHOWERS OVER NE WY AND NW SD.
GIVEN THE DRY LOW LVLS AND STEEP BELOW CLOUD LAPSE RATES THESE
STORMS COULD PRODUCE STRONG...GUSTY SFC WINDS DURING THE EVNG
HOURS. THE HRRR MODEL SHOWS A N TO S LINE OF TSTMS FROM NW SD
THROUGH RAP AND S WARD AT 03Z.
WITH THE APPROACH OF THE SECOND TROF FRIDAY AFTN THERE IS THE
CHANCE FOR MORE WIDESPREAD AND VIGOROUS CONVECTION. MOISTURE WILL
REAMIN LIMITED...BUT SFC BASED CAPE FCSTS OF ABT 1000 J/KG BY THE
18Z NAM LOOK REASONABLE. SFC TO 6KM SHEAR IS FCST TO RANGE FROM
ABOUT 40KTS OVER NW SD TO 20 KTS SE PORTIONS OF OUR CWA. A
BOUNDARY FROM TONIGHTS CONVECTION MAY PROVIDE SOME FOCUS AND WILL
BE REINFORCED BY INCREASING NRLY FLOW OVER WRN AND NWRN PORTIONS
OF THE CWA. NAM FCSTS THIS BOUNDARY TO BE FROM S OF RAP TO ROUGHLY
PHP AT 21Z FRIDAY.
WITH THE APPROACHING TROF...500 MB Q VECTOR CONVERGENCE REMAINS
OVER THE AREA FRIDAY NIGHT INTO SATURDAY EVG. POST FRONTAL SHOWERS
AND TSTMS SHOULD CONTINUE OVER MUCH THE AREA...GRADUALLY ENDING
FROM THE NW.
EXTENDED...AN UPPER RIDGE WILL BUILD INTO THE REGION EARLY NEXT WEEK
BRINGING DRY CONDITIONS. TEMPERATURES WILL BE NEAR AVERAGE
SUNDAY...WITH A GRADUAL WARMING TREND TO START THE WORK WEEK. MODELS
CONTINUE TO SHOW A SLOW MOVING UPPER TROUGH PUSHING INTO THE REGION
LATE TUESDAY INTO WEDNESDAY AND THURSDAY. MODELS CONSISTENCY IS
STILL LACKING (ECMWF CLOSES THE SYSTEM OFF WHILE GEM/GFS KEEP IT
OPEN)...BUT THIS COULD BRING A ROUND OF SHOWERS SHOWERS AND
THUNDERSTORMS TO THE AREA.
&&
.AVIATION...18Z TAFS
ISOLD/SCT TSRA AND SHRA WILL BE POSSIBLE THIS AFT AND EVE. VARIABLE
AND GUSTY WINDS ARE EXPECTED IN THE VICINITY OF ANY SHRA OR TSRA.
OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...BARBER
LONG TERM....77
AVIATION...77
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1218 PM CDT THU MAY 17 2012
.DISCUSSION.../ISSUED AT 1007 AM CDT/
NOT MUCH CHANGE TO CURRENT FORECAST. ACCAS SHOWERS NORTH OF WARM
FRONT HAS EXITED CWA WITH PARTLY TO MOSTLY SUNNY SKIES EXPECTED THIS
AFTERNOON. WINDS WILL BE GUSTY THIS AFTERNOON AND WILL BE CLOSE TO
WIND ADVISORY CRITERIA BUT WILL NOT ISSUE SINCE EVERYONE PRETTY MUCH
KNOWS IT IS WINDY. CURRENT TEMPERATURE FORECAST ON TRACK.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED TO REMAIN THROUGH 18Z FRIDAY. A STRONG LOW
LEVEL SOUTHERLY JET WILL PRODUCE LOW LEVEL WIND SHEAR AFTER 03Z
TONIGHT THROUGH 16Z FRIDAY. OTHERWISE...SURFACE WIND GUSTS TO 35
KNOTS CAN BE EXPECTED THROUGH 00Z TONIGHT AND DECREASE TO 15 TO 20
KNOTS 03Z TO 16Z FRIDAY AND THEN INCREASE TO 20 TO 35 KNOTS AGAIN
DURING THE DAY ON FRIDAY.
&&
.PREVIOUS DISCUSSION.../ISSUED AT 355 AM CDT/
WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS HAVE
DEVELOPED FROM JUST WEST OF SIOUX FALLS NORTHWARD ALONG THE
INTERSTATE 29 CORRIDOR OVERNIGHT UNDER THE INFLUENCE OF WARM
AIR/THETA E ADVECTION FACILITATED BY THE LOW LEVEL JET. ELEVATED
CONVECTION ALIGNS FAIRLY WELL WITH THE RUC 850-500MB OMEGA AND
INSTABILITY FIELDS...ALBEIT BOTH ARE RELATIVELY WEAK. THEREFORE
EXPECT THE ACTIVITY TO REMAIN ISOLATED IN NATURE. CONSIDERING WINDS
ARE HAULING AT 50-60 KTS AT TWO THOUSAND FEET...WILL NEED TO KEEP A
CLOSE EYE ON CELLS THAT DEVELOP AS THEY COULD BE WIND PRODUCERS. BY
DAYBREAK...ISOLATED ACTIVITY SHOULD BE MOSTLY CONFINED TO SW
MN...AND GRADUALLY WANE WITH LOSS OF THE LLJ INFLUENCE.
AFTER THE NOCTURNAL CONVECTION...THE NEXT ITEM OF FOCUS IS THE WIND
TODAY AND FRIDAY. 08Z SURFACE ANALYSIS ILLUSTRATED THE LOW
PRESSURE CENTER OVER WESTERN ND/SD. RELATIVELY TIGHT PRESSURE
GRADIENT AHEAD OF THIS FEATURE WILL SUPPORT WIND SPEEDS NEARING
ADVISORY CRITERIA /SUSTAINED 30 MPH/. NAM BUFKIT WINDS AT THE TOP OF
THE MIXED LAYER ARE CIRCA 40 KTS...BUT THERE WILL BE INCREASING
HIGH CLOUDS. WHILE ISOLATED LOCATIONS /ESPECIALLY HIGHER TERRAIN
AREAS/ COULD BRIEFLY HIT CRITERIA...DO NOT CURRENTLY EXPECTED
WIDESPREAD SUSTAINED SPEEDS AT 30 MPH. THEREFORE...WILL HOLD OFF
ON AN ADVISORY FOR NOW. TEMPERATURES WILL SOAR NEARLY 15 DEGREES
ABOVE NORMAL FOR THIS TIME OF YEAR...WITH HIGHS IN THE MID/UPPER
80S STILL APPEARING LIKELY.
LOWS TONIGHT WILL NOT DROP MUCH DUE TO THE PERSISTENT SOUTHERLY
FLOW AHEAD OF THE TROUGH. LOW TO MID 60S ARE EXPECTED TO BE COMMON
AT DAYBREAK FRIDAY. H85 TEMPERATURES CLIMB TO AROUND +22C ON
FRIDAY...WHICH SHOULD MAKE UPPER 80S AND LOWER 90S EASILY
ATTAINABLE.
THE COLD FRONT SHOULD REACH CENTRAL SD BY DAYBREAK SATURDAY...AND
TRACK EASTWARD ACROSS THE FORECAST AREA THROUGHOUT THE DAY. LIKELY
POPS SEEM WARRANTED ON SATURDAY AND SATURDAY NIGHT. INSTABILITY
AND SHEAR PARAMETERS ARE RATHER MARGINAL ON SATURDAY...SO SEVERE
THREAT STILL APPEARS TO BE FARTHER SOUTH. A FEW SHOWERS MAY LINGER
ON SUNDAY MAINLY EAST OF INTERSTATE 29...AND THEN RIDGING WILL
DEVELOP FOR THE START OF NEXT WEEK. AFTER TEMPERATURES ARE REDUCED
BACK INTO HE MID 60S TO LOWER 70S RANGE ON SUNDAY IN THE WAKE OF
THE FRONT...READINGS WILL GRADUALLY MODERATE TO VALUES IN THE
UPPER 70S AND LOWER 80S FOR TUESDAY.
SHOWER AND THUNDERSTORM CHANCES WILL RETURN FOR WEDNESDAY AND
THURSDAY...AS A RELATIVELY HEALTHY TROUGH TRACKS ACROSS THE NORTH
CENTRAL CONUS. HAVE INCLUDED 50-70 POPS FOR THIS SYSTEM.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MNZ071-072-080-081-
090.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1224 PM CDT THU MAY 17 2012
.SHORT TERM...
1022 AM CDT THU MAY 17 2012
MAIN FORECAST CONCERNS FOR THE AFTERNOON ARE WINDS AND DEWPOINTS.
15Z SURFACE ANALYSIS SHOWS LOW PRESSURE OVER THE DAKOTAS WITH A
PRESSURE FALL AREA OF NEAR 1 MB/HOUR OVER CENTRAL AND NORTHERN
MINNESOTA. THIS PRESSURE FALL AREA HAS BEEN TRANSLATING EASTWARD
THROUGH THE MORNING. THE PRESSURE GRADIENT HAS ALSO BEEN GRADUALLY
TIGHTENING THROUGH THE MORNING FROM WESTERN IOWA THROUGH MUCH OF
MINNESOTA. 12Z SOUNDING FROM MPX SHOWED A VERY DRY SOUNDING BELOW
650MB...BUT ALSO IMPORTANTLY 40 KT WINDS NEAR 950MB. A FEW SITES
THAT ARE ON THE HIGHER TERRAIN JUST SOUTH OF THE MINNESOTA RIVER
VALLEY HAVE BEEN EXPERIENCING WINDS OF 30 TO 40 MPH AND GUSTS NEAR
50 MPH. MEANWHILE...ALTOSTRATUS CLOUDS WITH BASES OF 9000 FT OR
HIGHER HAVE BEEN PUSHING EAST ACROSS MINNESOTA AND THE NORTH HALF OF
WISCONSIN...A RESULT OF ISENTROPIC LIFT IN THE WARM ADVECTION
PATTERN IN PLACE AHEAD OF THE LOW. IN ADDITION...ON WATER VAPOR A
SHORTWAVE TROUGH IS EVIDENT IN THE EASTERN DAKOTAS...LIKELY HELPING
OUT TOO TO PRODUCE THE CLOUDS. RADAR SHOWING SOME
PRECIPITATION...BUT MOST OF THIS HAS REMAINED AS VIRGA DUE TO THE
DRY SUB CLOUD AIR SEEN ON THAT MPX SOUNDING. KRST JUST REPORTED A
SPRINKLE...SO A LITTLE OF THIS VIRGA IS REACHING THE SURFACE.
REGARDING DEWPOINTS...THEY HAVE COME UP A LITTLE BIT DUE TO THE
NORMAL DIURNAL INCREASE...BUT THERE ARE LOWER ONES LURKING IN
SOUTHEAST IOWA (LOW TO MID 30S THERE).
WITH THE PRESSURE FALL AREA ANTICIPATED TO CONTINUE TRANSLATING
EASTWARD AND THE PRESSURE GRADIENT TIGHTENING...AND ALL OF THIS
HAPPENING DURING THE PEAK HEATING OF THE DAY...CONCERNED THAT
WINDS COULD TRY TO PUSH ADVISORY CRITERIA. CLOUDS RIGHT NOW OVER
MINNESOTA AND NORTHERN WISCONSIN ARE HOLDING MIXING DOWN
SOME...BUT THESE SHOULD DISSIPATE IN THE AFTERNOON AS THE
SHORTWAVE TROUGH WEAKENS AND PUSHES EAST...ALONG WITH THE
ISENTROPIC LIFT SHIFTING NORTH. 06Z MAV/00Z MET GUIDANCE BOTH
PUSH KRST AND KTOB TO AROUND 25 KT AT 21Z...WITH LATEST RAP
GUIDANCE SUGGESTING THE SAME THING. THESE SPEEDS ARE CLOSE TO
ADVISORY CRITERIA. AFTER COLLABORATION WITH MPX...DECIDED TO ERR
ON THE CAUTIOUS SIDE AND ISSUE THE ADVISORY FOR SOUTHEAST
MINNESOTA. TYPICALLY SOME OF NORTHEAST IOWA IS INCLUDED IN THESE
ADVISORY SITUATIONS TOO...BUT IT APPEARS RIGHT NOW THAT WINDS
ACROSS NORTHEAST IOWA WILL STAY BELOW ADVISORY CRITERIA.
REGARDING DEWPOINTS...WITH A PERSISTENT SOUTH FLOW...CONCERNED
THAT LOWER DEWPOINTS IN SOUTHEAST IOWA COULD ADVECT INTO THE
FORECAST AREA. CERTAINLY THE LACK OF RAIN LATELY WOULD SUPPORT
DEWPOINTS MIXING OUT...THOUGH WE HAVE GREENED UP. RAP RUNS HAVE
SUGGESTED DEWPOINTS DROPPING INTO THE 20S WITH SOUNDINGS THAT
SUGGEST LITTLE HELP FROM EVAPOTRANSPIRATION. MEANWHILE MOST OTHER
MODELS SUGGEST UPPER 30S TO LOW 40S AT BEST. FOR NOW HAVE
DISCOUNTED THE RAP RUNS...BUT LEANED TO THE LOW SIDE OF ALL OTHER
GUIDANCE. WILL BE INTERESTING TO SEE HOW LOW DEWPOINTS GET TODAY.
IF WE WERE NOT GREENED UP...TODAY WOULD BE CONCERNING FOR FIRE
WEATHER.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
315 AM CDT THU MAY 17 2012
17.00Z ECMWF/GFS STILL SHOWING DIFFERENCE IN TIMING OF THE COLD
FRONTAL PASSAGE ACROSS THE AREA/ASSOCIATED SHRA/TS CHANCES IN THE
SATURDAY NIGHT/SUNDAY TIME FRAME. THE GFS REMAINS THE FASTER OF
THE TWO MODELS WITH PASSAGE AROUND 18Z WHEREAS THE ECMWF HOLDS OFF
TIL EVENING. WITH THIS UNCERTAINTY...WILL KEEP MODEL CONSENSUS
APPROACH GOING FOR NOW. WITH SLOWER TIMING...THERE STANDS A CHANCE
FOR STRONG/SEVERE THUNDERSTORMS WITH AMPLE CAPE/BULK SHEAR
DEPICTED BY THE ECMWF. HOPEFULLY THE MODELS WILL HAVE THIS
RESOLVED A BIT BETTER WITHIN THE NEXT FEW RUNS. MODELS THEN KEEP
DIFFERENCES GOING THROUGH THE REMAINDER OF THE PERIOD WITH THE GFS
MAINTAINING A MORE PROGRESSIVE WAVE PATTERN COMPARED TO THE ECMWF.
ECMWF KEEPS TROUGH/COOLER CYCLONIC FLOW AROUND THE AREA SUNDAY
NIGHT THROUGH TUESDAY FOR A SMALL CHANCE OF SHOWERS/ISOLATED
THUNDER. THE GFS BRINGS RIDGING IN FAIRLY QUICK FOR A DRIER
SOLUTION. WILL KEEP MODEL CONSENSUS GOING HERE AS WELL DUE TO THE
UNCERTAINTY. UPPER/SURFACE FLOW BECOMES SOUTHERLY ON WEDNESDAY
WITH BOTH MODELS SHOWING A WEAK EMBEDDED WAVE ALOFT. THE ECMWF
SHOWS LIGHT QPF SIGNAL WITH THIS FEATURE WHILE THE GFS REMAINS
DRY. WILL INCLUDE A SLIGHT CHANCE OF SHOWERS/THUNDER FOR NOW.
OTHERWISE...LOOKS LIKE TEMPERATURES WILL START OFF SOME 10 DEGREES
ABOVE NORMAL ON SUNDAY IN THE MID 70-LOWER 80S...THEN NEAR NORMAL
IN THE 70S MON/TUE/WED.
&&
.AVIATION...THROUGH 18Z FRIDAY
1224 PM CDT THU MAY 17 2012
A PERSISTENT SOUTHERLY FLOW OF DRY AIR WILL HELP TO MAINTAIN VFR
CONDITIONS THROUGH THE FRIDAY. THE BIGGER ISSUE IS WINDS. A TIGHT
PRESSURE GRADIENT IN PLACE AHEAD OF LOW PRESSURE IN THE DAKOTAS
HAS ALREADY RESULTED IN GUSTS BETWEEN 20-30 KT AT BOTH TAF SITES.
LOOK FOR THE GUSTS AS WELL AS SUSTAINED SPEEDS TO INCREASE A
LITTLE MORE THIS AFTERNOON WITH DAYTIME HEATING. WINDS SHOULD COME
DOWN SOME THIS EVENING WITH LOSS OF HEATING...BUT A STRONG LOW
LEVEL JET COMING ACROSS TONIGHT SHOULD KEEP KRST GUSTY THROUGH
MUCH OF THE NIGHT. WITH KLSE IN THE VALLEY...FAVORING LIGHTER
WINDS AT THE SURFACE...HAVE INCLUDED LOW LEVEL WIND SHEAR FOR THE
LOW LEVEL JET. PLAN ON SOUTHERLY WINDS TO PICK BACK UP FRIDAY
MORNING WITHIN A FEW HOURS OF SUNRISE DUE TO MIXING. WINDS ON
FRIDAY DO NOT LOOK AS STRONG AS TODAY...DUE TO A WEAKER PRESSURE
GRADIENT FORECAST...BUT SUSTAINED SPEEDS OF 15 KT WITH GUSTS TO
25 KT OR SO LOOK LIKELY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1022 AM CDT THU MAY 17 2012
WI...NONE.
MN...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING
FOR MNZ079-086-087-094-095.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...DAS
AVIATION...AJ