Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/25/14
AREA FORECAST DISCUSSION
NWS TUCSON AZ
235 PM MST WED JUL 23 2014
.SYNOPSIS...ENOUGH MOISTURE IS BACK IN PLACE FOR A CHANCE OF SHOWERS
AND THUNDERSTORMS THIS AFTERNOON. HOTTER TEMPERATURES ARE POSSIBLE
AGAIN TODAY AND THURSDAY. THUNDERSTORMS ARE EXPECTED TO INCREASE
THIS WEEKEND... ESPECIALLY SATURDAY AFTERNOON AND SATURDAY NIGHT.
&&
.DISCUSSION...STORMS ARE CURRENTLY FORMING ACROSS CENTRAL PIMA
COUNTY AND ACROSS THE RIM. STORM MOTION IS PITIFUL THOUGH...WITH
MAYBE 10 MPH OF WESTERLY MOTION WITH THE FASTER MOVING STORMS. GIVEN
THE DECENT PRECIP WATER VALUES...I AM CONCERNED FOR ISOLATED FLOOD
THREAT. LATEST HRRR SEEMS TO HAVE THE BEST HANDLE ON THE CONVECTION
THUS FAR AND HINTS AT CONVECTION FOCUSED MAINLY ACROSS THE CENTRAL
PORTION OF OUR AREA...OR NEAR THE I-10 CORRIDOR. COULD SEE SOME
MARGINALLY SEVERE STORMS TODAY. BUT THE TALL SKINNY CAPE
PROFILE...ALSO NOTED WITH THE .05 NORMALIZED CAPE VALUE...SUGGEST
LIMITED PARCEL ACCELERATION TODAY SO IT MAY BE DIFFICULT TO SUSTAIN
STRONG A LASTING UPDRAFTS.
I INCREASED TOMORROWS MIN TEMPERATURES IN THE VALLEYS BY A FEW
DEGREES BASED ON MIN TEMPS FROM THIS MORNING. THE NEAR RECORD WARM
LOWS ARE AGAIN POSSIBLE UNLESS CONVECTIVE OUTFLOWS PROVIDE LOCALIZED
COOLING. THE UPPER RIDGE AGAIN DROPS SOUTH TOMORROW AND THE MODELS
RESPOND BY DECREASING THE MID LEVEL MOISTURE. SO CONVECTIVE ACTIVITY
SHOULD BE DOWN...BUT THE TEMPS WILL BE UP AGAIN. MOISTURE SLOWLY
RETURNS FRIDAY AND AN INVERTED TROUGH SHOULD MOVE ACROSS THE AREA
SATURDAY. SO WE CURRENTLY FOCUS THE HIGHEST POPS OVER THE NEXT 7
DAYS ON SATURDAY THINKING THE ADDED LIFT FROM THE INVERTED TROUGH
WILL BE ENOUGH TO OVERCOME THE MARGINAL MOISTURE CONTENT. MOISTURE
CONTENT STARTS TO DISSIPATE SUNDAY BEFORE A MORE PRONOUNCED DRYING
TREND BEGINS MONDAY.
NEXT WEEK...THE LONG WAVE PATTERN SHOWS A HIGH AMPLITUDE RIDGE OVER
THE WEST WITH A DEEP TROUGH OVER THE EAST. THIS TYPE OF BLOCKING
PATTERN CAN GREATLY REDUCE THE PRECIP CHANCES AND PROMOTE WARMER
THAN NORMAL CONDITIONS. CERTAINLY CAN NOT RULE OUT SOME ISOLATED
STORMS NEXT WEEK...BUT I`M MORE CONCERNED FOR THE EXCESSIVE HEAT
POTENTIAL. CURRENT GUIDANCE IS SHOWING SIMILAR TEMPS AS WE
EXPERIENCED THIS WEEK...BUT 850-700MB THICKNESS VALUES SUGGEST WE
MAY BE A FEW DEGREES TOO COOL FOR MAX TEMPS NEXT WEEK.
JJB
&&
.AVIATION...VALID THRU 24/18Z.
FAIR AMOUNT OF CLEARING HAS OCCURRED THIS MORNING WHICH HAS ALLOW
FOR SOME GOOD MIXING. THE GOOD THING IS THERE ISN`T MUCH WIND IN THE
LOW/MID LEVELS TO TAP INTO. THIS SHOULD KEEP MOST OF THE GUST WELL
BELOW 20KTS. THE ONE CAVEAT TO THAT WILL BE GIVEN THE INVERTED V
PROFILE SEEN IN POINT SOUNDINGS FROM ACROSS THE AREA ALL TERMINALS
WILL HAVE THE POTENTIAL FOR GUSTY OUTFLOW WINDS WITH THE CONVECTION.
ENOUGH INSTABILITY EXIST OVER THE AREA FOR CONVECTION THOUGH THERE
ISN/T MUCH IN THE HAIL GROWTH ZONE WHICH WILL LIMIT LIGHTNING
ACTIVITY. THAT BEING SAID...ONCE STORMS DEVELOP AND MODIFY THE
ENVIRONMENT THIS WILL LIKELY CHANGE QUICKLY. HOWEVER...GIVEN THE LOW
CONFIDENCE IN WHERE STORMS WILL DEVELOP AT THIS TIME WILL KEEP TS
OUT OF ALL TERMINALS AND WILL HANDLE WITH AMD ONCE DEVELOPMENT
OCCURS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...MOISTURE HAS RETURNED TO SOUTHEAST ARIZONA WITH
SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
ACROSS MOST OF SOUTHEAST ARIZONA. THERE WILL BE A BRIEF DOWNTURN IN
STORM COVERAGE THURSDAY BEFORE A MORE TYPICAL MONSOON PATTERN MOVES
IN BY THIS WEEKEND. EXPECT STRONG...GUSTY AND ERRATIC WINDS WITH THE
STRONGER THUNDERSTORMS. POTENTIALLY HOTTER TEMPERATURES WEDNESDAY
AND THURSDAY WITH STRONG HIGH PRESSURE NEARBY...BUT WITH THIS WILL
BE MITIGATED SOMEWHAT BY THE MOISTURE BACK IN THE PICTURE.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS TUCSON AZ
955 AM MST WED JUL 23 2014
.SYNOPSIS...ENOUGH MOISTURE IS BACK IN PLACE FOR A CHANCE OF SHOWERS
AND THUNDERSTORMS. HOTTER TEMPERATURES ARE POSSIBLE AGAIN TODAY AND
THURSDAY. THUNDERSTORMS ARE EXPECTED TO INCREASE THIS WEEKEND...
ESPECIALLY SATURDAY AFTERNOON AND SATURDAY NIGHT.
&&
.UPDATE...AVIATION DISCUSSION UPDATED BELOW.
&&
.DISCUSSION...A LITTLE MORE CONFIDENT IN STORM DEVELOPMENT TODAY
THAN WE HAVE EXPERIENCE RECENTLY. SOUTHEAST LOW LEVEL WINDS BASED ON
THE 12Z SOUNDING HELPED IMPROVE OUR MOISTURE CONTENT. PRECIP WATER
VALUE HIT 1.59...WHICH MATCHES THE SATELLITE DERIVED PRECIP WATER
FIELDS WITH THE 1.50 INCH VALUES ACROSS MUCH OF S.E. AZ. SOUNDING
ALSO SHOWED MORE INSTABILITY IN PLACE THAN RECENT DAYS...AND WITH
ABUNDANT SUNSHINE SO FAR TODAY AND EXPECTED HIGH TEMPS A FEW DEGREES
ABOVE CLIMO...WE ARE IN GOOD SHAPE TO REALIZE THAT POTENTIAL. THERE
WERE ALSO A FEW MCS EVENTS OVERNIGHT ACROSS NORTHERN MEXICO WHICH
LIKELY CONTRIBUTED TO OUR MOISTURE INCREASE TODAY.
HI RESOLUTION MODELS...HRRR AND WRF VARIANTS...HAVE A FEW
CONSISTENCIES FOR TODAY. THE CONSISTENCIES WOULD POINT TO THE BEST
SHOT FOR STORMS DEVELOPING IN THE 18 TO 20Z RANGE OVER THE EASTERN
ZONES...THEN SPREAD WEST INTO PIMA COUNTY DUE TO THE BETTER LL
EASTERLY MEAN FLOW STARTING AROUND 22 OR 23Z. CERTAINLY SOME
POTENTIAL FOR A STRONG WIND GUST OR TWO. IN FACT...OUR LOCAL WRF RUN
AND THE UOFA WRF BOTH HINT AT STRONG OUTFLOW IMPACTING PINAL COUNTY
TODAY. THAT MAKES ME A LITTLE NERVOUS FOR BLOWING DUST...BUT GIVEN
THAT THE HRRR IS NOT SHOWING THE OUTFLOW AT ALL...I PLAN TO PLAY THE
WAIT AND SEE GAME TODAY AND HOLD OFF ON ISSUING ANY DUST ADVISORIES.
FINGERS WILL BE ON THE TRIGGER THOUGH IF RADAR TRENDS SUPPORT THE
WRF RUNS. EITHER WAY...BE AWARE OF THE BLOWING DUST POTENTIAL ACROSS
PINAL COUNTY TODAY.
JJB
&&
.AVIATION...VALID THRU 24/18Z.
FAIR AMOUNT OF CLEARING HAS OCCURRED THIS MORNING WHICH HAS ALLOW
FOR SOME GOOD MIXING. THE GOOD THING IS THERE ISN`T MUCH WIND IN THE
LOW/MID LEVELS TO TAP INTO. THIS SHOULD KEEP MOST OF THE GUST WELL
BELOW 20KTS. THE ONE CAVEAT TO THAT WILL BE GIVEN THE INVERTED V
PROFILE SEEN IN POINT SOUNDINGS FROM ACROSS THE AREA ALL TERMINALS
WILL HAVE THE POTENTIAL FOR GUSTY OUTFLOW WINDS WITH THE CONVECTION.
ENOUGH INSTABILITY EXIST OVER THE AREA FOR CONVECTION THOUGH THERE
ISN/T MUCH IN THE HAIL GROWTH ZONE WHICH WILL LIMIT LIGHTNING
ACTIVITY. THAT BEING SAID...ONCE STORMS DEVELOP AND MODIFY THE
ENVIRONMENT THIS WILL LIKELY CHANGE QUICKLY. HOWEVER...GIVEN THE LOW
CONFIDENCE IN WHERE STORMS WILL DEVELOP AT THIS TIME WILL KEEP TS
OUT OF ALL TERMINALS AND WILL HANDLE WITH AMD ONCE DEVELOPMENT
OCCURS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...MOISTURE HAS RETURNED TO SOUTHEAST ARIZONA TODAY
WITH SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS ACROSS MOST OF SOUTHEAST ARIZONA TODAY. THERE WILL BE
A BRIEF DOWNTURN IN STORM COVERAGE THURSDAY BEFORE A MORE TYPICAL
MONSOON PATTERN MOVES IN BY THIS WEEKEND. EXPECT STRONG...GUSTY AND
ERRATIC WINDS WITH THE STRONGER THUNDERSTORMS. POTENTIALLY HOTTER
TEMPERATURES WEDNESDAY AND THURSDAY WITH STRONG HIGH PRESSURE
NEARBY...BUT WITH THIS WILL BE MITIGATED SOMEWHAT BY THE MOISTURE
BACK IN THE PICTURE.
&&
.PREV DISCUSSION...MOISTURE HAD FINALLY RETURNED TO SOUTHEAST
ARIZONA AS DEWPOINT TEMPERATURES WERE RUNNING AROUND 60 DEGREES
EARLY THIS MORNING. RECENT IR SATELLITE IMAGERY WAS SHOWING SOME
EXTENSIVE CLOUD COVER ACROSS THE AREA...WITH RADAR SHOWING A FEW
LIGHT SHOWERS AROUND ESPECIALLY ACROSS CENTRAL PIMA COUNTY. THAT
SAID...STILL EXPECTING HOTTER AFTERNOON TEMPERATURES TODAY EVEN
THOUGH THE RAIN CHANCES HAVE INCREASED AND A CLOUDY SKY WAS PRESENT.
THIS MOISTURE INCREASE WILL BE BRIEF AS DRIER AIR PUSHES IN FROM THE
EAST AND THE UPPER HIGH SHIFTS SOUTHWARD TOMORROW. THIS BREAK WILL
ALSO BE SHORT LIVED AS MODELS TRACK AN UPPER LEVEL DISTURBANCE
THROUGH MEXICO WHICH WILL LIKELY BRING A NOTICEABLE UPSWING IN
THUNDERSTORMS ACTIVITY OVER THE WEEKEND. HIGH TEMPERATURES WILL BE
ABOVE NORMAL THROUGHOUT THE FORECAST PERIOD...BUT THE WARMEST DAYS
WILL OCCUR TODAY THROUGH FRIDAY...WHEN READINGS WILL BE 8 TO 12 DEGS
ABOVE NORMAL. OTHERWISE...EXPECT HIGHS TO BE 3 TO 6 DEGS ABOVE
NORMAL. LOWS GENERALLY 4 TO 6 DEGS ABOVE NORMAL EACH DAY...BUT THE
WARMEST MORNINGS SHOULD OCCUR WEDNESDAY THROUGH FRIDAY.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS PUEBLO CO
327 PM MDT WED JUL 23 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 308 PM MDT WED JUL 23 2014
BOUNDARY FROM EARLY MORNING CONVECTION ACROSS NORTHEAST COLORADO
HAS PUSHED BACK WESTWARD INTO KIOWA AND NORTHEAST BENT COUNTY AS
OF 1 PM...AND EXTENDS TO THE NORTHEAST TO NEAR KLIC...TO
KDEN...THEN BACK TO THE SOUTHWEST TOWARDS THE NORTHERN BORDER OF
TELLER COUNTY. WHILE WESTERN PORTIONS OF THIS BOUNDARY HAVE
STALLED AND IS BEGINNING TO SHIFT BACK NORTHWARD...EASTERN
PORTIONS OF THIS BOUNDARY CONTINUE TO BACKDOOR WESTWARD INTO THE
SOUTHEAST PLAINS WITH DEW POINTS IN THE 60S BEHIND IT. TO THE
SOUTH OF THIS BOUNDARY...SOUTHERLY WINDS ARE INCREASING...BUT DEW
POINTS HAVE BEEN MORE STUBBORN TO MIX OUT TODAY...AND REMAIN IN
THE 40S AND 50S. STILL THINK THERE IS SOME FURTHER MIXING OUT THAT
WILL OCCUR DURING THE AFTERNOON AND EVENING HOURS...BUT HRRR AND
RAP13 APPEAR TO BE DRYING OUT DEW POINTS TOO VIGOROUSLY...EVEN IN
THE LATEST RUNS. THIS ELEVATES CONCERNS FOR POTENTIAL FOR A SLOW
MOVING THUNDERSTORM TO DEVELOP OVER THE WALDO BURN SCAR SOMETIME
THIS AFTERNOON AND EVENING. ANOTHER AREA OF CONCERN WILL BE ACROSS
THE WEST FORK BURN SCAR....THOUGH LATEST OBS OUT THAT WAY SHOW DEW
POINTS HAVE ALREADY DROPPED INTO THE 30S AND CONVECTION DOES NOT
LOOK ALL THAT STRONG YET. THUS APPEARS MAIN AREA TO MONITOR WILL
BE ACROSS TELLER AND EL PASO COUNTIES THIS EVENING...AND THREAT
AREA MAY END UP BEING JUST TO THE NORTH OF TELLER COUNTY. WILL
ALSO HAVE TO WATCH THE BOUNDARY ACROSS THE FAR SOUTHEAST PLAINS
FOR THUNDERSTORM DEVELOPMENT. MIXED LAYER CAPES ALONG THIS
BOUNDARY ARE AROUND 4000 J/KG OFF THE SPC MESO ANALYSIS...HOWEVER
THERE IS ALSO A FAIR OF CIN BEHIND THE OUTFLOW BOUNDARY AS WELL.
NONE OF THE SHORT RANGE MODELS ARE DEVELOPING THUNDERSTORMS ALONG
THIS BOUNDARY BENEATH THE UPPER HIGH. DEEP LAYER SHEAR IS
WEAK...SO ANY SEVERE POTENTIAL WOULD BE MORE LIKELY TO BE FROM A
PULSE TYPE SEVERE WHICH COULD PERSIST IF A STORM CAN ANCHOR TO THE
BOUNDARY. BUT WITH THE LACK OF FORCING THIS SEEMS TO BE A LOW END
PROBABILITY OF OCCURRENCE. HOWEVER...IT DEFINITELY BEARS WATCHING.
THUNDERSTORMS SHOULD DIMINISH THIS EVENING WITH LOSS OF
HEATING...THOUGH WITH MONSOON PLUME OVER THE MOUNTAINS WILL MAINTAIN
SOME ISOLATED POPS THROUGH THE NIGHT AS IS TYPICAL THIS TIME OF
YEAR.
FOR THURSDAY...UPPER RIDGE FLATTENS WHICH PUTS THE MONSOON PLUME
ALOFT ACROSS MOST OF CO. MODELS SUGGEST A WEAK SHORTWAVE WILL MOVE
OVERTOP THE RIDGE WHICH WILL HELP TO FIRE OFF THUNDERSTORMS ACROSS
THE MOUNTAINS THEN SEND THEM TO THE EAST ACROSS THE ADJACENT PLAINS.
BOTH NAM AND GFS SUGGEST NORTHERN PORTION SO OF THE FORECAST AREA
MAY SEE A BETTER CHANCE FOR THUNDERSTORMS TOMORROW...AND THIS WILL
PUT WALDO UNDER A SLIGHTLY HIGHER THREAT THAN TODAY. AGAIN...DEEP
LAYER SHEARS ARE WEAK...SO THREAT FOR SEVERE WEATHER OVERALL LOOKS
LOW. STORM MOTIONS SHOULD BE A LITTLE FASTER AND TOWARDS THE
EAST...BUT PROBABLY NOT FAST ENOUGH TO MITIGATE THE POTENTIAL
LOCALIZED FLASH FLOODING ON THE BURN SCARS SHOULD THEY TAKE AN
UNLUCKY STRIKE. SO ANOTHER DAY OF MONITORING THE WALDO BURN SCAR
CLOSELY WILL BE IN STORE. STORM STRENGTH WILL DEPEND ON HOW MUCH
SURFACE DEW POINTS MIX OUT...AND WITH WESTERLY FLOW OVER THE
AREA...UPPER 30S TO LOWER 40 DEW POINTS LOOK LIKELY...WHICH SHOULD
KEEP CAPE VALUES GENERALLY BELOW 1000 J/KG. HAVE KEPT HIGHER POPS
ACROSS THE CENTRAL MOUNTAINS AND PIKES PEAK REGION FOR TOMORROW.
OTHERWISE...WESTERLY FLOW SHOULD HELP DRY OUT SURFACE DEW POINTS
ACROSS THE PLAINS...WHICH SHOULD LIMIT CAPE AND THUNDERSTORM
COVERAGE. THIS MAY ALSO BE SUFFICIENT TO BOOST TEMPS INTO THE LOWER
100S ACROSS THE LOWER ARKANSAS RIVER VALLEY. HOWEVER...AN INCREASE
IN CONVECTIVE CLOUD COVER MAY ALSO LIMIT HEATING SOME...ESPECIALLY
FOR THE I-25 CORRIDOR SO HAVE KEPT PUB BELOW THE CENTURY MARK FOR
NOW. LOCATIONS FARTHER EAST SHOULD HAVE AN EASIER TIME OF HITTING
AROUND 100. -KT
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 308 PM MDT WED JUL 23 2014
...MORE MONSOON NEXT WEEK...
THE EXTENDED FORECAST LOOKS PRETTY TYPICAL FOR LATE JULY...AS
AN UPPER RIDGE DOMINATES THE WEATHER THROUGH NEXT WEEK. BUT THERE
WILL BE TWO DISTINCT PATTERNS THAT WILL SHAPE OUR WEATHER.
THE FIRST HALF OF THE PERIOD WILL BE A CONTINUATION OF THE HOT AND
RELATIVELY DRY WEATHER WE HAVE BEEN EXPERIENCING THIS WEEK. A WEAK
FRONTAL SURGE WILL USHER IN A LITTLE MORE UPSLOPE THU NIGHT INTO
FRIDAY...AND THIS MAY HELP GENERATE A FEW MORE SHOWERS AND STORMS
OVER THE AREA FRIDAY AFTERNOON AND EVENING. WE WILL STILL BE UNDER
THE UPPER RIDGE AXIS...AND WITH TEMPS ALOFT STILL PRETTY
HIGH...EXPECT ANOTHER HOT DAY WITH TEMPS SOARING INTO THE HIGH 90S
OVER THE PLAINS. MAYBE EVEN A DEGREE OR TWO HOTTER ON SATURDAY
AS THE RIDGE EXPANDS A BIT TO THE NORTH.
THEN...A FRONTAL SURGE ASSOCIATED WITH A STRONG TROUGH DIGGING
OVER ERN CANADA WILL BRING A CHANGE TO OUR WEATHER BEGINNING
SUNDAY. IT LOOKS SOMEWHAT SIMILAR TO OUR LAST PERIOD OF WET
WEATHER...AS A STRONG UPSLOPE REGIME SETS UP OVER THE PLAINS AND
DEWPOINTS CLIMB FROM THE 40S AND LOWER 50S TO THE UPPER 50S AND
EVEN 60 DEGREE MARK BY EARLY NEXT WEEK. AT THIS TIME...IT LOOKS
LIKE SUNDAY AFTERNOON-EVE...WITH THE INITIAL SURGE...AND THEN
TUESDAY AFTERNOON AND EVE...WITH A SECONDARY PUSH OVER THE CENTRAL
PLAINS...WILL BE THE WETTEST DAYS. EVERY DAY WILL SEE THE
POTENTIAL FOR SOME LOCALLY HEAVY RAINFALL...BUT THOSE PERIODS ARE
PROBABLY THE HIGHEST THREAT FOR THE BURN SCARS AND POTENTIAL FLASH
FLOODING. COULD ALSO SEE SOME SVR STORMS ESPECIALLY ON TUESDAY OVR
THE PLAINS...AS NW FLOW ALOFT INCREASES A BIT AS THE RIDGE MOVE
WWD. TEMPS SHOULD SETTLE BACK INTO THE 70S AND 80S FROM SUNDAY
ONWARD THROUGH NEXT WEEK AS COOLER AND MOISTER AIR ARRIVES FROM
THE NORTH. ROSE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 308 PM MDT WED JUL 23 2014
VFR CONDITIONS EXPECTED AT THE TAF SITES OVER THE NEXT 24 HOURS.
ISOLATED THUNDERSTORMS OVER THE MOUNTAINS COULD AFFECT KALS AND
KCOS LATE THIS AFTERNOON THROUGH THIS EVENING...SO WILL MAINTAIN
VCTS FOR THESE SITES. ERRATIC WIND GUSTS TO 45 KTS AND LOCALIZED
HEAVY RAINFALL WILL BE THE PRIMARY THREATS...BUT PROBABILITY LOOKS
TOO LOW AT THIS POINT TO INCLUDE IN A TEMPO GROUP. THUNDERSTORMS
WILL DIMINISH THIS EVENING. ANOTHER ROUND OF THUNDERSTORMS WILL
DEVELOP ACROSS THE MOUNTAINS ON THURSDAY. WINDS WILL INCREASE OUT
OF THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AT 10-20 KTS. KCOS
MAY SEE A SLIGHTLY BETTER CHANCE OF SEEING -TSRA AT THE TERMINAL
DURING THE LATE AFTERNOON AND EARLY EVENING. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT
LONG TERM...ROSE
AVIATION...KT
AREA FORECAST DISCUSSION
NWS TAUNTON MA
418 PM EDT WED JUL 23 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TONIGHT TRIGGERING SCATTERED
SHOWERS AND THUNDERSTORMS. A FEW STRONG THUNDERSTORMS ARE
POSSIBLE WEST OF THE CENTRAL HILLS. SHOWERS WILL LIKELY LINGER
INTO THURSDAY SOUTHEAST OF THE BOSTON TO PROVIDENCE CORRIDOR. HIGH
PRESSURE BUILDS WITH DRIER WEATHER FOR FRIDAY AND SATURDAY. AN
APPROACHING WARM FRONT SUNDAY WILL BRING MORE HUMID UNSETTLED
WEATHER FOR THE EARLY PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
* A FEW STRONG TO SEVERE STORMS POSSIBLE LATE THIS AFTERNOON INTO
THE EVENING HOURS *
415 PM MESO-UPDATE...
CONTINUING TO MONITOR FOR THE POTENTIAL FOR STRONG TO SEVERE
THUNDERSTORMS LATE THIS AFTERNOON INTO THE EVENING HOURS.
CURRENTLY THE COLD FRONT HAS JUST PUSHED THROUGH ITHACA NY UP TO
MONTPELIER VT...AND WILL CONTINUE A EASTWARD PROGRESSION TOWARDS
SOUTHERN NEW ENGLAND THROUGH THE REMAINDER OF THE DAY. OVER THE
NEXT FEW HOURS...BELIEVE A FEW ISOLATED SHOWERS AND THUNDERSTORMS
WILL POP- UP /JUST LIKE THEY ARE IN MOHAWK VALLEY REGION/. THEN
EXPECT A MORE BROKEN LINE SEGMENT TO MOVE THROUGH BY THE EVENING
HOURS AS THE FRONT MOVES CLOSER TO THE REGION.
LOOKING AT SPC MESO ANALYSIS...SB CAPE VALUES HAVE REACHED TO 2500
J/KG WITH NOT MUCH IN THE TERMS OF EFFECTIVE SHEAR FOR SOUTHERN NEW
ENGLAND. RAP 0-6 KM BULK SHEAR VALUES HAVE INCREASED
SLIGHTLY...AND ARE NOW 15-20 KTS. AS OF 20Z...THE STRONGER WIND
SHEAR AND UPPER LEVEL JET DYNAMICS ARE STILL SITUATED ACROSS
UPSTATE NEW YORK WHICH IS ALSO WHERE THE DEEP LAYER MOISTURE IS
LOCATED PER THE K-INDEX. HENCE WHY THE STORMS ARE SUSTAINING
THEMSELVES.
OVERVIEW AND INTO TONIGHT...
A COLD FRONT WILL PASS ACROSS THE NORTHEAST EARLY THIS EVENING AND
INTO THE EARLY OVERNIGHT HOURS. ALTHOUGH WE ARE CURRENTLY LACKING
MOISTURE AND SHEAR AS MENTIONED ABOVE...RAP GUIDANCE SHOWS THAT
BOTH OF THESE PARAMETERS WILL INCREASE CLOSER TO 00Z. THEREFORE
BELIEVE THAT SHOWERS AND STRONGER THUNDERSTORMS WILL DEVELOP AND
OVERSPREAD THE REGION AS THE FRONT PUSHES CLOSER TO SOUTHERN NEW
ENGLAND.
THROUGHOUT THE EVENING HOURS...THE MAIN CONCERN IS THE AMOUNT OF
INSTABILITY WITH LACK OF SOLAR HEATING BY THE LATE EVENING HOURS.
CURRENT THINKING THOUGH IS THAT SINCE THE ATMOSPHERE HAS NOT BEEN
WORKED OVER AND THE GUIDANCE SHOWS LINGER ELEVATED INSTABILITY
OVERNIGHT BELIEVE THAT THE THUNDERSTORM POTENTIAL WILL LINGER TIL
ABOUT MIDNIGHT. BY THEN THE STORMS WILL ENTER THE THE EASTERN
PORTION OF THE AREA WHICH IS BEING INFLUENCED BY THE ADVECTING
MARITIME AIR FROM TODAYS GUSTY SOUTHWEST WINDS.
STILL CANNOT RULE OUT THE POTENTIAL FOR SEVERE WEATHER BUT HAVE
INCREASING CONFIDENCE THAT AT LEAST STRONG STORMS WILL DEVELOP LATE
THIS AFTERNOON INTO THE EVENING HOURS. AFTER DISCUSSING WITH SPC
DECIDED TO ISSUE A WATCH FOR THE LOCATIONS THAT HAVE THE BEST
POTENTIAL TO SEE THE BEST MOISTURE/INSTABILITY AND SHEAR OVERLAPPING
ONE ANOTHER. THE MAIN THREATS ARE DAMAGING WINDS AND LOCALIZED
FLOODING AS PWATS CONTINUE TO INCREASE ABOVE 1.8 INCHES.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
THURSDAY...
COLD FRONT WILL SLOW DOWN DURING ITS PASSAGE ACROSS SOUTHERN NEW
ENGLAND THURSDAY MORNING. BOTH THE EC AND NAM SHOW A WAVE DEVELOPING
ALONG THE FRONT ALLOWING FOR THE SLOW DOWN WHILE THE GFS SEEMS TO BE
THE OUTLIER ON PUSHING THE FRONT THOUGH BY 12Z. IN FACT THE UPPER
LEVEL TROUGH AXIS IS STILL ACROSS UPSTATE NY BY 12/15Z RESULTING IN
CLOUDS AND THE CONFIDENCE THAT PRECIP WILL LINGER ESP FOR AREAS
SOUTH AND EAST OF THE BOS-PVD CORRIDOR. BELIEVE THAT BY 00Z THE
FRONT AND THE BULK OF THE PRECIP WILL BE OFFSHORE BUT CANNOT RULE
OUT A FEW LINGERING SHOWERS ESP FOR THE CAPE AND THE ISLANDS.
BECAUSE OF THE SLOW DOWN AND THE POTENTIAL WAVE
DEVELOPMENT...CANT RULE OUT THE POTENTIAL FOR EMBEDDED
THUNDERSTORMS DURING THE DAY.
DRIER AIR WILL WORK ITS WAY IN BEHIND THE FRONT RESULTING IN A
COOLER DAY WITH HIGHS WELL BELOW AVERAGE AND CLOSE TO 15 DEGREES
COOLER THEN TODAY. ASIDE FROM THE CLOUDS AND LINGERING PRECIP
CHANCES...SHOULD BE A PLEASANT DAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
*/ HIGHLIGHTS...
- DRY AND SEASONABLE INTO FRIDAY
- RETURN OF WARM AND MUGGIER CONDITIONS FOR SATURDAY
- SIGNIFICANT WEATHER SATURDAY NIGHT INTO EARLY NEXT WEEK
- A RETURN OF DRY AND SEASONABLE WEATHER BY MIDWEEK
*/ OVERVIEW AND MODEL PREFERENCE...
SURPRISING PATTERN AS WE CLOSE OUT THE MONTH OF JULY! AS PRESENT NW
PACIFIC IMPULSE EJECTS E IT COUPLES WITH AN UPPER-LEVEL LOW PARKED
OVER NE CANADA RESULTING IN TROUGH ENHANCEMENT THROUGH THE GREAT
LAKES REGION. SUBSEQUENT DOWNSTREAM RIDGING OVER THE N-ATLANTIC AND
RIDGE STRENGTHENING OVER THE W-CONUS AHEAD OF A PACIFIC IMPULSE
BOTTLED IN THE GULF OF ALASKA...THE ATMOSPHERIC PATTERN BUCKLES.
WITH THE STAGNANT PATTERN IN PLACE...ANOMALOUS CONDITIONS PREVAIL AS
DECENT AGREEMENT AMONG ENSEMBLE MEMBERS SIGNAL A -3 TO -4 SD IN
HEIGHTS/TEMPERATURE/HUMIDITY.
BUT A NOTE OF CAUTION: SIMILAR ENSEMBLE MEMBERS OUT TO D8 AND INTO
EARLY AUGUST ARE EXHIBITING CONSIDERABLE SPREAD WITHIN NAO/PNA
TRENDS. IT IS WITH NO CERTAINTY AS TO HOW THIS PATTERN WILL EVOLVE.
THIS MAKES THE FORECAST OVER THE NE-CONUS DIFFICULT FURTHER OUT IN
TIME AS NEW ENGLAND ESPECIALLY FINDS ITSELF WITHIN THE E-PERIPHERY
OF THE AFOREMENTIONED TROUGH. JUST A SLIGHT WOBBLE OF THE OVERALL
BUCKLED PATTERN E OR W CAN RESULT IN CONSIDERABLE CHANGES IN THE
FORECAST.
FEEL THE DECENT AGREEMENT BETWEEN DETERMINISTIC AND ENSEMBLE MEMBERS
WARRANTS A BLEND OF MODEL GUIDANCE TOWARDS THE FORECAST. WILL HIT ON
THE MAIN POINTS ALONG WITH ANY PREFERRED GUIDANCE IN THE DAILIES
BELOW.
*/ DAY-TO-DAY DETAILS...
THURSDAY NIGHT THROUGH SATURDAY...
THINKING A DRY FORECAST PERIOD WITH THE RRQ OF THE UPPER-LEVEL JET
SHIFTING SE. FEEL THE COLD FRONT AND ATTENDANT WAVE LOW WILL REMAIN
OVER THE WATERS. SHOWERS DISSIPATING /IF ANY/ TOWARDS MIDNIGHT AS
DYNAMICS ARE SHUNTED OUT OF THE REGION.
OTHERWISE...HIGH PRESSURE AND LIGHT NW-FLOW SWEEPS ACROSS NEW
ENGLAND FRIDAY /SEA-BREEZES ALONG THE SHORES/ FOLLOWED BY RETURN
BREEZY S/SW-FLOW FOR THE REMAINDER OF THE PERIOD AS THE HIGH SLIDES
E/SE AND LOW PRESSURE BEGINS TO BUILD IN FROM THE W. SEASONABLE WX
INITIALLY...BUT EXPECT THE RETURN OF WARMER/MUGGIER CONDITIONS BY
SATURDAY. LOOKING CLEAR FOR FRIDAY...DIURNAL CUMULUS FOR SATURDAY.
SATURDAY NIGHT INTO EARLY NEXT WEEK...
THE EVOLUTION OF THE TROUGH AND THE PROXIMITY OF ITS E-PERIPHERY ARE
KEYS TO THE FORECAST /AS IS THE OFFSHORE ENHACING RIDGE ACROSS THE N-
ATLANTIC/. THE TRACK TIMING AND MORPHOLOGY OF INDIVIDUAL IMPULSES
THROUGH THE CYCLONIC FLOW WILL ULTIMATELY DETERMINE THE POTENTIAL
OUTCOMES FOR THE REGION.
FOR SATURDAY NIGHT INTO SUNDAY...SEEMINGLY AN INITIAL IMPULSE IS A
FOCUS FOR CONVECTIVE ACTIVITY /PERHAPS A MCS/ WHERE THERMAL/MOIST
AXES AND SUBSEQUENT INSTABILITY CONVERGE AT THE SURFACE AND ALONG
THE NOSE OF A LLJ REAR OF AN ATTENDANT WARM-FRONT. THE MORE ZONAL
REGIME ADVECTS THIS ACTIVITY W-TO-E. NEARLY UNI-DIRECTIONAL SHEAR
PRESENTS A THREAT OF DAMAGING WIND. BUT EARLY IN TIME AND LIKELY
ABUNDANCE OF CLOUD COVER...THREAT MAY BE LIMITED. HINTS OF MID-LEVEL
DRYING AND WAKE SUBSIDENCE? JUST A HUGE MESS. MAY BE LOOKING AT MORE
WIDESPREAD STRATIFORM WITH EMBEDDED THUNDERSTORMS. WHO KNOWS...JUST
A FIRST GUESS. BIGGEST CONCERN IS THE PLUME OF PWATS EXCEEDING 1.5
INCHES AND A POSSIBLE RISK OF FLASH FLOODING. SOME CONFIDENCE OF
THAT AT LEAST.
INTO MONDAY...THE LOW DEEPENS AS IT OCCLUDES OVER THE GREAT LAKES.
ALONG AND AHEAD OF THE COLD FRONT WITHIN WARM/MUGGY/UNSTABLE
CONDITIONS...CONVECTION IS LIKELY WITHIN AN ENVIRONMENT OF DEEP-
LAYER FORCING...BUT IT IS JUST TOO EARLY TO GO INTO DETAIL. MANY
QUESTIONS AS TO WHETHER THE ENVIRONMENT WILL DESTABILIZE BENEATH
STRONG SW-NE UNI-DIRECTIONAL SHEAR. APPEARS ACTIVITY MAY OCCUR IN
THE MORNING ONCE AGAIN FOLLOWED BY MID-LEVEL DRYING AND SUBSIDENCE.
YEESH. AGAIN...LOTS OF UNCERTAINTY. ONLY CONFIDENCE IS WITH SURGING
PWATS IN EXCESS OF 2-INCHES CONINTUING THE POSSIBLE RISK OF FLASH
FLOODING.
A FINAL NOTE...EVALUATING THE 23.0Z AND 23.12Z CIPS ANALOGS...BOTH
PING UPON POTENTIAL CONVECTIVE THREATS SUNDAY AND MONDAY. THE
PROBABILITIES OF SEVERE WEATHER IMPACTS HAVE SLIGHTLY INCREASED WITH
THE 23.12Z ANALOGS /UP TO 70-PERCENT/. SO WHILE THE ABOVE DISCUSSION
CONTAINS A FAIR AMOUNT OF UNCERTAINTY...THE FORECAST STILL WARRANTS
CLOSE MONITORING.
AT SOME POINT THE COLD FRONT SHOULD PUSH E BEHIND WHICH DRIER AND
COOLER AIR WRAPPING INTO THE OCCULUSION SHOULD PREVAIL RESULTING IN
SEASONABLE CONDITIONS FOR THE REGION. WHETHER THIS OCCURS ON TUESDAY
OR WEDNESDAY...JUST TOO UNCERTAIN.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH THURSDAY/...
GENERALLY MODERATE CONFIDENCE ON FORECAST.
THROUGH 22Z...GENERALLY VFR.
AFTER 22Z INTO TONIGHT...MVFR CIGS AND VSBYS IN VICINITY OF SCT
TSTMS AHEAD OF A COLD FRONT. A FEW TSTMS MAY BRIEFLY LOWER
CIGS/VSBYS TO IFR LEVELS. ALSO...A FEW TSRA MAY PRODUCE STRONG
WIND GUSTS. THERE IS ALSO A MODERATE POTENTIAL FOR IFR CIGS
FORMING TONIGHT ACROSS THE CAPE AND ISLANDS.
THURSDAY...GENERALLY MVFR CIGS AND VSBYS TO START IN ANTICIPATED
RAIN OR SHOWERS. CONDITIONS WILL BE IMPROVING FROM NW TO SE
THROUGH MUCH OF THE DAY. EXCEPT ALONG AND SE OF A PYM-UUU LINE
WHICH MAY STAY IN LOWER CLOUDS THROUGH MUCH OF
THURSDAY...IMPROVING LATE.
KBOS TAF...HIGH CONFIDENCE. VFR THROUGH MOST OF THE DAY. TSTMS
POSSIBLE AFT 00Z TO THE N AND W OF BOS AND CLOSER TO THE AIRFIELD
ITSELF BY 03Z.
KBDL TAF...HIGH CONFIDENCE IN TAF. TSTMS POSSIBLE AFT 22Z. ANY
TSTMS COULD CONTAIN STRONG WIND GUSTS.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
THURSDAY NIGHT THROUGH SATURDAY...HIGH CONFIDENCE.
VFR. -RA MOVES OUT THURSDAY NIGHT UNDER NW FLOW. LIGHT WINDS AND
MOSTLY CLEAR ON FRIDAY /SEA-BREEZES ALONG THE SHORES/. SCT-BKN 5 KFT
CIGS SATURDAY WITH BREEZY S/SW WINDS.
SATURDAY NIGHT THROUGH MONDAY...LOW CONFIDENCE.
PERIODS OF RA/TSRA. MIX OF MVFR-IFR CONDITIONS...WORST OF WHICH
ANTICIPATED DURING OVERNIGHT PERIODS AND +RA. CONTINUED BLUSTERY
S/SW WINDS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH THURSDAY/...MODERATE CONFIDENCE.
THE SW FLOW WILL STRENGTHEN AHEAD OF A COLD FRONT TO PRODUCE GUSTS
APPROACHING 25 KT ACROSS MANY OF THE NEAR SHORE WATERS...THEREFORESCA
IS STILL IN EFFECT. SEAS MAY APPROACH 5 FEET EAST OF CAPE ANN THIS
EVENING. OTHERWISE WILL NEED TO MONITOR FOR AREAS OF FOG THAT MAY
DEVELOP ALONG THE SOUTH COASTAL WATERS TONIGHT.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
THURSDAY NIGHT THROUGH SATURDAY...HIGH CONFIDENCE.
TRANQUIL BOATING WEATHER. SOME SHOWERS MAY LINGER ALONG THE SE OUTER-
WATERS THURSDAY NIGHT...BUT SHOULD BE GOOD AFTER MIDNIGHT. HIGH
PRESSURE AND LIGHT NW-FLOW FRIDAY /SEA-BREEZES ALONG THE SHORES/.
WINDS VEER S/SW OVERNIGHT AND BECOME BREEZY DURING THE DAY SATURDAY.
SATURDAY NIGHT THROUGH MONDAY...LOW CONFIDENCE.
WEATHER TURNING SOUR. INCREASE S/SW WINDS AHEAD OF A STRONG LOW OVER
THE GREAT LAKES REGION WILL RESULT IN SIGNIFICANT WAVE HEIGHTS OVER
THE S-WATERS ESPECIALLY. SHOWERS/THUNDERSTORMS ANTICIPATED SOME OF
WHICH COULD BE STRONG.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
ANZ230>237-251.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT THURSDAY FOR ANZ250-254.
&&
$$
SYNOPSIS...DUNTEN/SIPPRELL
NEAR TERM...DUNTEN/SIPPRELL
SHORT TERM...DUNTEN
LONG TERM...SIPPRELL
AVIATION...DUNTEN/SIPPRELL
MARINE...DUNTEN/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
240 PM EDT WED JUL 23 2014
.SYNOPSIS...
WEATHER WILL BE HOT AND HUMID WEATHER TODAY AHEAD OF AN
APPROACHING COLD FRONT. THE FRONT WILL TRIGGER SCATTERED SHOWERS
AND THUNDERSTORMS LATE THIS AFTERNOON AND EVENING. A FEW STRONG
THUNDERSTORMS ARE POSSIBLE WEST OF I-495 AND NORTH OF THE MASS
PIKE AND I-84. SHOWERS WILL LIKELY LINGER INTO THURSDAY SOUTHEAST
OF THE BOSTON TO PROVIDENCE CORRIDOR. HIGH PRESSURE BUILDS WITH
DRIER WEATHER FOR FRIDAY AND SATURDAY. AN APPROACHING WARM FRONT
SUNDAY WILL BRING MORE HUMID UNSETTLED WEATHER FOR THE EARLY PART
OF NEXT WEEK.
&&
.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
* A FEW STRONG TO SEVERE STORMS POSSIBLE LATE THIS AFTERNOON INTO
THE EVENING HOURS *
CONTINUE TO MONITOR FOR THE POTENTIAL FOR STRONG TO SEVERE
THUNDERSTORMS LATE THIS AFTERNOON INTO THE LATE EVENING HOURS.
CURRENTLY THE COLD FRONT HAS JUST PUSHED THROUGH SYRACUSE NY AND
WILL CONTINUE ITS EASTWARD PROGRESSION TOWARDS SOUTHERN NEW
ENGLAND THROUGH THE AFTERNOON. AS IT APPROACHES ANTICIPATE
ISOLATED SHOWERS AND THUNDERSTORMS TO POP-UP AT FIRST BUT THEN A
MORE BROKEN LINE SEGMENT TO MOVE THROUGH BY THE EVENING HOURS.
LOOKING AT SPC MESO ANALYSIS...SB CAPE VALUES HAVE REACHED TO 2500
J/KG WITH NOT MUCH IN THE TERMS OF EFFECTIVE SHEAR FOR SOUTHERN
NEW ENGLAND. RAP 0-6KM BULK SHEAR VALUES ARE WEAK AS WELL...WITH
ONLY 10-15 KTS. AS OF 18Z...THE STRONGER WIND SHEAR AND UPPER
LEVEL JET DYNAMICS ARE STILL SITUATED UP NEAR THE COLD FRONT WHICH
IS ALSO WHERE THE DEEP LAYER MOISTURE IS LOCATED PER THE K-INDEX.
HENCE WHY THE STORMS ARE STARTING TO FIRE ACROSS UPSTATE NEW
YORK.
AS THE FRONT MOVES EASTWARD DURING THE AFTERNOON...SOME OF THESE
PARAMETERS WILL ALSO SHIFT EASTWARD. THE BIGGEST LIMITING FACTOR
FOR US RIGHT NOW IS THE LACK OF DEEP LAYER MOISTURE AND SHEAR...WHICH
IS NOT PROJECTED TO MOVE INTO THE REGION UNTIL CLOSER TO 00Z.
THEREFORE BELIEVE THAT JUST A FEW ISOLATED LOW TOP SHOWERS WILL
DEVELOP OVER THE NEXT FEW HOURS. AFTER 00Z THE FRONT WOULD HAVE
MOVED CLOSER TO THE REGION WITH BETTER SHEAR AND MOISTURE. THE ONE
THING TO BE CONCERN IS THE AMOUNT OF INSTABILITY. WITH THE
ATMOSPHERE NOT BEING WORKED OVER AND THE WARM...MOIST ATMOSPHERE
BOILING OVER THE REGION TODAY BELIEVE ONCE THE STORMS MOVE INTO
THE REGION THEY WILL EAT UP ANY INSTABILITY AND DEVELOP INTO
STRONG STORMS.
STILL CANNOT RULE OUT THE POTENTIAL FOR SEVERE WEATHER BUT HAVE
INCREASING CONFIDENCE THAT AT LEAST STRONG STORMS WILL DEVELOP.
AFTER DISCUSSING WITH SPC DECIDED TO ISSUE A WATCH FOR THE
LOCATIONS THAT ARE PROGGED TO HAVE THE BEST MOISTURE/INSTABILITY
AND SHEAR FOR WHEN/IF THUNDERSTORMS MOVE OVER THOSE LOCATIONS.
MAIN THREATS ARE DAMAGING WINDS AND LOCALIZED FLOODING AS PWATS
CONTINUE TO INCREASE ABOVE 1.8 INCHES.
&&
.SHORT TERM /MIDNIGHT THROUGH 6 PM THURSDAY/...
* SHOWERS WILL LIKELY LINGER ACROSS THE CAPE...ISLANDS AND
ADJACENT SE MASSACHUSETTS DURING MUCH OF THURSDAY
THURSDAY...
THE FRONT DEACCELERATES AS IT APPROACHES SOUTHEAST NEW ENGLAND AND
THEN A WAVE MOVES ALONG THE FRONT DURING THE DAY THURSDAY.
THUS...EXPECT SHOWERS TO LINGER THURSDAY MORNING ACROSS THE
SOUTHEAST HALF OF THE AREA AND FOR MOST OF THE DAY ACROSS CAPE
COD...THE ISLANDS AND ADJACENT SOUTHEAST MA.
WILL BE MUCH COOLER THURSDAY BEHIND THE FRONT...AND SOUTHEAST OF
THE BOSTON TO PROVIDENCE CORRIDOR CLOUDS WILL ALSO ACT TO CAP THE
TEMPERATURE. FOR MOST LOCATION...EXPECT HIGHS IN THE 70S ON
THURSDAY. THE ATMOSPHERE MAY BE MARGINALLY UNSTABLE ENOUGH TO
SUPPORT A FEW EMBEDDED THUNDERSTORMS OVER THE CAPE AND ISLANDS AS
WELL AS SOUTHEAST COASTAL WATERS ON THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
BIG PICTURE...
FOUR FEATURES IN THE LARGE SCALE FLOW. TROUGH ALONG THE PACIFIC
NORTHWEST COAST...RIDGE EXTENDING FROM THE ROCKIES AND PLAINS TO
NORTHERN CANADA...CLOSED LOW OVER NORTHERN QUEBEC WITH TROUGH AXIS
ACROSS THE GREAT LAKES...BUILDING RIDGE OVER THE WESTERN ATLANTIC.
THE QUEBEC TROUGH HANGS OVER NORTHEAST NORTH AMERICA...THE TROUGH
AXIS AND COLDEST TEMPS ALOFT SWING ACROSS NEW ENGLAND THURSDAY
NIGHT/FRIDAY. THE PACIFIC NORTHWEST TROUGH RUNS OVER THE TOP OF THE
ROCKIES RIDGE...THEN MERGES WITH THE QUEBEC LOW OVER THE WEEKEND.
THIS DRAWS THE CLOSED LOW SOUTH OVER THE GREAT LAKES/NORTHEAST EARLY
NEXT WEEK. THE ATLANTIC HIGH PRESSURE MEANWHILE BLOCKS OFF THE
EASTWARD EXIT OF THIS MERGER. THE COMBINATION OF UPPER LOW PRESSURE
OVER THE LAKES AND HIGH PRESSURE OVER THE ATLANTIC CREATES A
SOUTHWEST FLOW UP THE EAST COAST FROM THE DEEP SOUTH FOR THE FIRST
HALF OF NEXT WEEK.
MODELS HAVE BEEN SHOWING CONSISTENCY BOTH RUN TO RUN AND WITH EACH
OTHER. THIS INCREASES CONFIDENCE IN THE OVERALL SOLUTION...BUT WITH
THE USUAL UNCERTAINTY IN TIMING SHORTWAVES MOVING THROUGH THE
FLOW. THIS IS ESPECIALLY TRUE FOR MONDAY AND TUESDAY.
THE DAILIES...
THURSDAY NIGHT...COLD FRONT LINGERS OFFSHORE WHILE THE UPPER JET
RIGHT ENTRANCE REGION MOVES OVERHEAD. THIS MAY SUPPORT A WAVE ALONG
THE FRONT DURING THE FIRST PART OF THE NIGHT...BUT THE JET SHIFTS
EAST AFTER MIDNIGHT AS SHOULD THE SUPPORTING DYNAMICS. WE WILL KEEP
CHANCE POPS ON THE CAPE AND ISLANDS EARLY IN THE NIGHT. IF THE JET
POSITION AT 00Z IS AS ADVERTISED...WE MAY BE A LITTLE CONSERVATIVE
ON EVENING POPS. OTHERWISE THE MOVEMENT OF THE UPPER JET SHOULD
TREND SOUTHERN NEW ENGLAND TO END ANY REMAINING PCPN AND BRING
CLEARING SKIES.
FRIDAY-SATURDAY... SURFACE HIGH PRESSURE BUILDS OVER THE REGION WITH
DRY WEATHER AND DEWPOINTS IN THE 50S. TEMPS AT THE TOP OF THE MIXED
LAYER WILL SUPPORT UPPER 70S TO MID 80S BOTH DAYS...A LITTLE WARMER
SATURDAY.
ONE CONCERN WILL BE SEA BREEZE DEVELOPMENT ON FRIDAY WHICH MAY HOLD
DOWN AFTERNOON TEMPS ON THE EASTERN COAST. OTHER CONCERN WOULD BE
THE PASSAGE OF THE UPPER TROUGH AND COLDER TEMPS ALOFT. THIS LATTER
CONCERN COULD DESTABILIZE THE AIRMASS AND PROMOTE CUMULUS
DEVELOPMENT. BUT MODEL RH FIELDS SHOW A DRY AIRMASS WITH RH VALUES
BELOW 700 MB BELOW 50 PERCENT. WILL KEEP SKY COVER LOW FRIDAY...THEN
INCREASING CIRRUS ON SATURDAY AFTERNOON.
SUNDAY... PACIFIC NORTHWEST SHORTWAVE DIGS AS IT APPROACHES THE
GREAT LAKES AND GENERATES A SURFACE LOW. STRONG LOW LEVEL JET IS
EXPECTED TO DEVELOP IN THE OHIO VALLEY SATURDAY WITH 35-40 KNOT
WINDS AT 850 AND 900 MB. AS THIS MOVES EAST IT WILL BRING DEEPER
MOISTURE TO NEW ENGLAND WITH PRECIP WATER VALUES CLIMBING TO 1.5
INCHES BY SUNDAY. THE LIFTING OF THIS AIR OVER THE DEPARTING SURFACE
LAYER WOULD GENERATE SOME SHOWERS/SCT TSTMS. WE WILL MENTION CHANCE
POPS LATER SATURDAY NIGHT INTO SUNDAY.
MONDAY-TUESDAY...THE MERGING LOW OVER THE GREAT LAKES SURFACE AND
ALOFT WILL SWING A FRONT THROUGH NEW ENGLAND. TIMING IS IN QUESTION
AT THIS POINT WITH THE GFS SHOWING FROPA MONDAY NIGHT WHILE THE
ECMWF STALLS THE FRONT OVER US. WITH NO CLEAR TREND ON A DAY 7
FORECAST...WE WILL STAY CLOSE TO BLENDED GUIDANCE SOLUTION OF
DIMINISHING POPS TUESDAY. BUT WITH LOW CONFIDENCE.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH THURSDAY/...
GENERALLY MODERATE CONFIDENCE ON FORECAST.
THROUGH 22Z...GENERALLY VFR.
AFTER 22Z INTO TONIGHT...MVFR CIGS AND VSBYS IN VICINITY OF SCT
TSTMS AHEAD OF A COLD FRONT. A FEW TSTMS MAY BRIEFLY LOWER
CIGS/VSBYS TO IFR LEVELS. ALSO...A FEW TSRA MAY PRODUCE STRONG
WIND GUSTS. THERE IS ALSO A MODERATE POTENTIAL FOR IFR CIGS
FORMING TONIGHT ACROSS THE CAPE AND ISLANDS.
THURSDAY...GENERALLY MVFR CIGS AND VSBYS TO START IN ANTICIPATED
RAIN OR SHOWERS. CONDITIONS WILL BE IMPROVING FROM NW TO SE
THROUGH MUCH OF THE DAY. EXCEPT ALONG AND SE OF A PYM-UUU LINE
WHICH MAY STAY IN LOWER CLOUDS THROUGH MUCH OF
THURSDAY...IMPROVING LATE.
KBOS TAF...HIGH CONFIDENCE. VFR THROUGH MOST OF THE DAY. TSTMS
POSSIBLE AFT 00Z TO THE N AND W OF BOS AND CLOSER TO THE AIRFIELD
ITSELF AFT 03Z.
KBDL TAF...HIGH CONFIDENCE IN TAF. TSTMS POSSIBLE AFT 22Z. ANY
TSTMS COULD CONTAIN STRONG WIND GUSTS.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...MODERATE CONFIDENCE.
THURSDAY NIGHT THROUGH SATURDAY...VFR. LOCAL IFR POSSIBLE IN EARLY
MORNING FOG/LOW CLOUDS. POTENTIAL SEA BREEZE FRIDAY AFTERNOON.
SUNDAY...
VFR BUT WITH AREAS OF MVFR IN SHOWERS/TSTMS/FOG.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH THURSDAY/...MODERATE CONFIDENCE.
THE SW FLOW WILL STRENGTHEN AHEAD OF A COLD FRONT TO PRODUCE GUSTS
APPROACHING 25 KT ACROSS MANY OF THE WATERS. SEAS MAY APPROACH 5
FEET EAST OF CAPE ANN...ACROSS THE E PORTION OF STELLWAGEN
BANK...AND E OF CAPE COD THIS AFTERNOON. ALTHOUGH THE WIND WAVE
WILL BE FORMED FROM THE SW FLOW...THERE IS ALSO A SWELL THAT IS
ENCROACHING THE COASTAL WATERS FROM THE EAST. ALTHOUGH OF FAIRLY
LOW AMPLITUDE OF LESS THAN 3 FEET...THE SWELL APPEARS TO BE
ENOUGH TO TRIGGER A MODERATE RIP CURRENT RISK ALONG PORTIONS OF
THE EAST FACING COAST. AREAS OF FOG MAY DEVELOP ALONG THE SOUTH
COASTAL WATERS TONIGHT.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...MODERATE CONFIDENCE.
THURSDAY NIGHT-FRIDAY-SATURDAY... NORTH TO NORTHEAST WIND THURSDAY
NIGHT BECOMES LIGHT FRIDAY WITH AFTERNOON SEA BREEZES DEVELOPING.
WINDS BECOME SOUTHWEST SATURDAY BUT REMAIN BELOW 25 KNOTS. SEAS 4
FEET OR LESS THROUGH THE PERIOD.
SUNDAY...A WARM FRONT APPROACHES THE WATERS WITH WARMER MORE HUMID
AIR AND WITH CLOUDS/SHOWERS/TSTMS. INCREASING SOUTH-SOUTHWEST WINDS
WITH GUSTS 20-22 KNOTS...APPROACHING SMALL CRAFT THRESHOLD. THESE
WINDS WILL ALSO BUILD SEAS ON THE EXPOSED WATERS TO 5 OR 6 FEET. A
SMALL CRAFT ADVISORY MAY BE NEEDED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ230>237-251.
SMALL CRAFT ADVISORY UNTIL 3 AM EDT THURSDAY FOR ANZ250-254.
&&
$$
SYNOPSIS...WTB/THOMPSON
NEAR TERM...DUNTEN
SHORT TERM...THOMPSON
LONG TERM...WTB
AVIATION...WTB/DUNTEN
MARINE...WTB/THOMPSON
AREA FORECAST DISCUSSION
NWS ALBANY NY
122 PM EDT WED JUL 23 2014
.SYNOPSIS...
HAZY...HAZY...HOT AND HUMID CONDITIONS EXPECTED THIS AFTERNOON AHEAD
OF A COLD FRONT. THIS COLD FRONT WILL BRING SHOWERS AND
THUNDERSTORMS TO THE AREA THROUGH THIS EVENING. BEHIND THE COLD
FRONT...COOLER AND LESS HUMID AIR IS EXPECTED FOR THURSDAY AND
FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM EDT...RADARS INDICATED A FEW CELLS POPPING UP ACROSS
NORTHERN HERKIMER AND PORTIONS OF CENTRAL NEW YORK. THE COLD FRONT
WAS WORKING THROUGH THE SAINT LAWRENCE VALLEY WITH PERHAPS A
PRE-FRONTAL TROUGH SETTING UP WELL TO THE WEST OF THE HUDSON
VALLEY.
TEMPERATURES WERE ALREADY INTO THE MID 80S IN THE HUDSON VALLEY SO
FOR THIS UPDATE WENT AHEAD AND BUMPED SOME OF THESE UP SEVERAL
DEGREES...WHICH WOULD MEAN THE CAPITAL REGION SHOULD APPROACH OR
EVEN ECLIPSE 90 DEGREES.
SO FOR THIS UPDATE...BUMPED TEMPERATURES UPWARD...RE-TOOLED HOURLY
GRIDS BUT LEFT THE REMAINDER OF THE FORECAST ALONE.
AREA 12Z SOUNDINGS SHOW QUITE A BIT OF INSTABILITY OVER THE
REGION...ESPECIALLY UPSTREAM...WHERE CONVECTION IS EXPECTED TO
INITIATE EARLY THIS AFTERNOON. WE ARE CAPPED AT MIDLEVELS HERE IN
EASTERN NY AND WESTERN NEW ENGLAND BUT AGAIN...UPSTREAM...THE CAP
IS MUCH LESS.
BOUNDARY LAYER WINDS ARE NOT TOO STRONG...BUT ENOUGH SO THAT
THUNDERSTORM DOWNDRAFTS WILL ENHANCE THE WINDS FOR A DAMAGING WIND
THREAT IN THUNDERSTORMS THROUGH THIS EVENING. LOW LEVEL WINDS ARE
LIGHT FROM THE SOUTH AND SOUTHEAST OVER EASTERN NY NOW...BUT WEST
TO SOUTHWEST IN CENTRAL AND WESTERN NY. WILL HAVE TO SEE IF LOW
LEVEL WINDS REMAIN SOUTH TO SOUTHEAST IN EASTERN NY...AS SHEAR
COULD BE ENOUGH FOR STRONGER ROTATING THUNDERSTORMS.
IT COULD BE A BUSY AFTERNOON AND EVENING WITH REGARD TO COVERAGE AN
STRENGTH OF THUNDERSTORMS...WITH A DAMAGING WIND AND LARGE HAIL
THREAT. THE LATEST HRRR INDICATED ACTIVITY IN OUR REGION SHOULD
BLOSSOM BETWEEN 2 AND 5 PM.
MORE ANALYSIS OF GUIDANCE WAS DESCRIBED IN THE PREVIOUS AFD WHICH
IS BELOW...
THE WARM SECTOR IS WELL ENTRENCHED ACROSS THE REGION AS METAR
DEWPOINTS WERE BETWEEN 65-70F AND VERY LITTLE IN THE WAY OF CLOUD
COVER. THIS WILL SET THE STAGE FOR AN ACTIVE WEATHER DAY ACROSS
THE REGION /AS ALREADY SEEN UPSTREAM WITH A LINE OF STRONG
CONVECTION UNDERWAY/ AS GOOD INSOLATION...HIGH MOISTURE CONTENT
AS PWATS CLIMB TO NEAR 2 INCHES...SBCAPES AT OR ABOVE 2K J/KG AND
DEEP LAYER SHEAR AROUND 30KTS /THE HIGHER VALUES ACROSS THE
NORTHERN PORTIONS OF THE REGION/ TO SUPPORT THE EXTENSION OF THE
SLIGHT RISK PER SPC COORDINATION ACROSS THE ENTIRE REGION. THE
MAIN THREAT REMAINS FROM DAMAGING WIND GUSTS AND/OR WET
MICROBURSTS GIVEN THE PRECIP LOADING IN A VERY MOIST COLUMN. HAIL
POTENTIAL LOOKS LOW AT THIS TIME AS WET BULB FREEZING LEVELS PER
THE BUFR PROFILES ARE EXPECTED AT OR ABOVE 13K FEET. WE WILL
RETAIN THE ENHANCED WORDING FOR HEAVY RAINFALL AND GUSTY WINDS IN
THE GRIDS ALONG WITH THE STRONGLY WORDED HWO. NCEP MODEL SUITE IS
IN GOOD AGREEMENT WITH THE TIMING OF THE FROPA WHICH REACHES OUR
DACKS REGION AROUND THE LUNCH HOUR...CAPITAL REGION BETWEEN 2PM-
4PM...AND THE MID HUDSON VALLEY AND NW CT BETWEEN 5PM-8PM.
IN THE WAKE OF FROPA...WINDS SHIFT TO WEST AND NORTHWEST BEFORE
MIDNIGHT. HOWEVER...A WAVE IS EXPECTED TO DEVELOP ALONG THE
BOUNDARY WHICH WILL SLOW DOWN THE FORWARD PROGRESS SOMEWHAT TO
KEEP CHC-SCT POPS SOUTH OF I90. WHILE THIS FROPA WILL USHER IN
MORE STABLE AND LESS HUMID CONDITIONS...LOW LEVEL MOISTURE CONTENT
REMAINS HIGH SO WE WILL RETAIN THE PARTLY-MOSTLY CLOUDY SKIES IN
THE FORECAST.
HIGHS TODAY WILL BE NEAR 90 IN MOST VALLEY LOCATIONS...WITH HEAT
INDICES INTO THE MID AND UPPER 90S. HIGHER TERRAIN WILL SEE HIGHS IN
THE MID TO UPPER 80S...EXCEPT COOLER ACROSS THE ADRIONDACKS WHERE
CLOUDS AND SHOWERS SHOULD KEEP HIGHS BELOW 80. A SOUTH WIND 5 TO 15
MPH WILL DO LITTLE TO STIFLE THE HEAT. HOWEVER...THE SHOWERS AND
THUNDERSTORMS WILL BEGIN TO COOL US DOWN AFTER 400 PM.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
A MORE STABLE...COOLER AND LESS HUMID AIR MASS ADVECTS INTO THE
REGION THURSDAY AND FRIDAY AS HIGH PRESSURE BUILDS INTO THE
REGION. RESIDUAL CLOUD COVER ACROSS THE REGION...ESPECIALLY ACROSS
THE SOUTHERN PORTIONS OF THE REGION...WILL MIX OUT TO PARTLY
CLOUDY/SUNNY CONDITIONS. CYCLONIC FLOW ALOFT REMAINS ALOFT A H850
TEMPS DIP BACK TO AROUND 10C. HIGHS THURSDAY WILL AVERAGE AT OR
JUST BELOW 80F FOR VALLEY LOCATIONS WITH THURSDAY NIGHT LOWS INTO
THE 50S WITH 40S ACROSS THE DACKS AND PORTIONS OF THE MOHAWK
VALLEY. HIGHS FRIDAY REBOUND BACK INTO THE LOWER 80S FOR VALLEY
LOCATIONS...MID-UPR 70S ELSEWHERE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PERIOD LOOKS RATHER UNSETTLED STARTING WITH THE SECOND
HALF OF THE WEEKEND.
FOR FRIDAY NIGHT AND SATURDAY EXPECT DRY AND SEASONABLE CONDITIONS
AS A RIDGE OF HIGH PRESSURE SLIDES OFF THE EASTERN SEABOARD. EXPECT
LOWS FRIDAY NIGHT IN THE 50S WITH HIGHS ON SATURDAY IN THE MID 70S
TO MID 80S.
START TO INCREASE POPS FROM SLIGHT CHANCE SATURDAY EVENING TO CHANCE
POPS LATE SATURDAY AS FA STARTS TO BE CONVERGED UPON BY SEVERAL LOW
PRESSURE SYSTEMS ONE PASSING THROUGH THE MID ATLANTIC REGION AND A
SECOND ONE PASSING THROUGH THE UPPER GREAT LAKES REGION. LOWS
SATURDAY NIGHT ARE EXPECTED TO BE IN THE MID 50S TO MID 60S.
SUNDAY THROUGH TUESDAY LOOKS TO BE ACTIVE AS THE SERIES OF LOW
PRESSURE SYSTEMS CONVERGE ACROSS THE NORTHEAST. TIMING AND LOCATION
OF INDIVIDUAL LOW PRESSURE SYSTEMS DIFFER AMONGST THE MODELS. SO AT
THIS POINT IN TIME WILL PLACE CHANCE POPS IN THE GRIDS THROUGH THE
PERIOD WITH MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.
HIGHS ARE EXPECTED TO RANGE FROM THE MID 70S TO MID 80S SUNDAY AND
MONDAY AND IN THE UPPER 60S TO UPPER 70S ON TUESDAY. LOWS ARE
EXPECTED TO BE IN THE MID 50S MID 60S.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A BROKEN BAND OF SHOWERS AND THUNDERSTORMS IS DEVELOPING IN NORTHERN
AND WESTERN NY...WITH MORE ISOLATED ACTIVITY IN CENTRAL NY. A STRONG
COLD FRONT WILL SUPPORT MORE WIDESPREAD SHOWERS AND THUNDERSTORMS
TRACKING ACROSS THE REGION LATER THIS AFTERNOON AND EVENING. OUTSIDE
OF SHOWERS AND THUNDERSTORMS...CONDITIONS SHOULD BE VFR. TIMING OF
THUNDERSTORMS IN TAFS BASED ON CURRENT TRENDS AND TIMING INDICATED
IN MESOSCALE MODELS. IT LOOKS LIKE AROUND 21Z-22Z AT KGFL AND
KALB...22Z-23Z AT KPSF AND 23Z-24Z AT KPOU. SOME LOCALIZED
CONVERGENCE ASSOCIATED WITH THE MOHAWK/HUDSON RIVER INTERSECTION
NEAR THE KALB AIRPORT COULD SPARK A LOCALIZED SHOWER OR STORM BEFORE
22Z BUT WILL WATCH TRENDS CAREFULLY. WILL AMEND ONCE THUNDERSTORMS
DEVELOP AND CAN BE TIMED MORE PRECISELY... BUT INDICATED MVFR
CONDITIONS IN THUNDERSTORMS. THERE COULD BE SOME BRIEF IFR
CONDITIONS IN BRIEF BURSTS AND AGAIN WILL AMEND IF THESE CONDITIONS
LOOK IMMINENT LATER THIS AFTERNOON AND EVENING. THERE COULD BE GUSTY
VARIABLE WINDS AROUND 25 KT OR MORE IN THUNDERSTORMS AS WELL.
ONCE THE THUNDERSTORMS END...KEEPING VCSH FOR A FEW HOURS FOR
LINGERING ACTIVITY...BUT LONGER...THROUGH ABOUT 09Z AT KPOU SINCE
THE FRONT MAY SLOW ITS PROGRESS IN SOUTHERN AREAS. SOME FOG MAY
FORM AFTER SOME CLEARING AT KGFL...KALB AND KPSF TOWARD DAYBREAK BUT
ONLY INDICATING 6SM BR UNTIL WE CAN ANALYZE SHORT TERM TRENDS BEHIND
THE FRONT AFTER SUNSET.
AFTER SUNRISE TOMORROW...VFR EVERYWHERE...BUT WILL HAVE TO SEE IF
ANY SHOWERS LINGER AROUND KPOU AFTER 09Z IF THE PROGRESS OF THE
FRONT SLOWS.
SOUTH TO SOUTHWEST WINDS THIS AFTERNOON AT 10 KT OR LESS COULD BE
VARIABLE AND GUSTY TO 25 KT OR MORE IN THUNDERSTORMS. THE WINDS
SHOULD SHIFT TO WEST AND NORTHWEST BY THIS EVENING AT LESS THAN 10
KT...THE DIMINISH TO LESS THAN 6 KT AND TREND TOWARD NORTH.
TOMORROW MORNING...WINDS SHOULD BE NORTH NORTHWEST TO NORTH
NORTHEAST AT LESS THAN 10 KT.
OUTLOOK...
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. CHANCE OF SHRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
&&
.FIRE WEATHER...
SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE REGION TODAY ALONG
AND AHEAD OF A COLD FRONT. RELATIVELY HIGH MOISTURE CONTENT AHEAD
OF THIS BOUNDARY WILL KEEP RH VALUES AT OR ABOVE 50 PERCENT. THE
RH VALUES TONIGHT AT BETTER THAN 80 PERCENT.
THE SURFACE WIND WILL BE SOUTH TO SOUTHWEST THIS MORNING AT 5 TO 10
MPH...THEN BECOMING SOUTHWEST TO WEST MID DAY AT 5 TO 15 MPH WITH
SOME GUSTS TO 20 MPH. WINDS SHIFT TO A WEST THEN NORTHWEST
DIRECTION TONIGHT.
&&
.HYDROLOGY...
SHOWERS AND THUNDERSTORM WILL OCCUR ACROSS THE AREA AS A COLD
FRONT APPROACHES AND INTERACTS WITH THE VERY WARM AND HUMID AIR
MASS IN PLACE ACROSS THE REGION. PRECIPITABLE WATER VALUES ARE
EXPECTED TO INCREASE NEAR 2 INCHES...SO ANY STORM WILL CAPABLE OF
VERY HEAVY DOWNPOURS WHICH COULD CAUSE LOCALIZED FLOODING OF LOW
LYING AND POOR DRAINAGE AREAS. HAVE CONTINUED ENHANCED WORDING FOR
THE HEAVY RAINFALL TO THE FORECAST FOR THIS AFTERNOON AND EVENING
AND WILL RETAIN THIS MENTION IN OUR HAZARDOUS WEATHER OUTLOOK.
WITH THE PASSAGE OF THE COLD FRONT...A COOLER AND LESS HUMID AIR
WILL BE USHERED IN. EXPECTED SOME LINGERING SHOWERS INTO THURSDAY
MORNING AS THE FRONT WILL BE SLOW TO MOVE OFF TO THE EAST. THEN
LOOKING AT DRY WEATHER INTO AT LEAST THE FIRST HALF OF THE
WEEKEND. THE WEATHER WILL TURN UNSETTLED AS WE HEAD INTO THE
SECOND HALF OF THE WEEKEND AND INTO NEXT WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/BGM
NEAR TERM...HWJIV/BGM/NAS
SHORT TERM...BGM
LONG TERM...11
AVIATION...NAS
FIRE WEATHER...BGM
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
1230 PM EDT WED JUL 23 2014
.SYNOPSIS...
HAZY...HAZY...HOT AND HUMID CONDITIONS EXPECTED THIS AFTERNOON AHEAD
OF A COLD FRONT. THIS COLD FRONT WILL BRING SHOWERS AND
THUNDERSTORMS TO THE AREA THROUGH THIS EVENING. BEHIND THE COLD
FRONT...COOLER AND LESS HUMID AIR IS EXPECTED FOR THURSDAY AND
FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM EDT...RADARS INDICATED A FEW CELLS POPPING UP ACROSS
NORTHERN HERKIMER AND PORTIONS OF CENTRAL NEW YORK. THE COLD FRONT
WAS WORKING THROUGH THE SAINT LAWRENCE VALLEY WITH PERHAPS A
PRE-FRONTAL TROUGH SETTING UP WELL TO THE WEST OF THE HUDSON
VALLEY.
TEMPERATURES WERE ALREADY INTO THE MID 80S IN THE HUDSON VALLEY SO
FOR THIS UPDATE WENT AHEAD AND BUMPED SOME OF THESE UP SEVERAL
DEGREES...WHICH WOULD MEAN THE CAPITAL REGION SHOULD APPROACH OR
EVEN ECLIPSE 90 DEGREES.
SO FOR THIS UPDATE...BUMPED TEMPERATURES UPWARD...RE-TOOLED HOURLY
GRIDS BUT LEFT THE REMAINDER OF THE FORECAST ALONE.
AREA 12Z SOUNDINGS SHOW QUITE A BIT OF INSTABILITY OVER THE
REGION...ESPECIALLY UPSTREAM...WHERE CONVECTION IS EXPECTED TO
INITIATE EARLY THIS AFTERNOON. WE ARE CAPPED AT MIDLEVELS HERE IN
EASTERN NY AND WESTERN NEW ENGLAND BUT AGAIN...UPSTREAM...THE CAP
IS MUCH LESS.
BOUNDARY LAYER WINDS ARE NOT TOO STRONG...BUT ENOUGH SO THAT
THUNDERSTORM DOWNDRAFTS WILL ENHANCE THE WINDS FOR A DAMAGING WIND
THREAT IN THUNDERSTORMS THROUGH THIS EVENING. LOW LEVEL WINDS ARE
LIGHT FROM THE SOUTH AND SOUTHEAST OVER EASTERN NY NOW...BUT WEST
TO SOUTHWEST IN CENTRAL AND WESTERN NY. WILL HAVE TO SEE IF LOW
LEVEL WINDS REMAIN SOUTH TO SOUTHEAST IN EASTERN NY...AS SHEAR
COULD BE ENOUGH FOR STRONGER ROTATING THUNDERSTORMS.
IT COULD BE A BUSY AFTERNOON AND EVENING WITH REGARD TO COVERAGE AN
STRENGTH OF THUNDERSTORMS...WITH A DAMAGING WIND AND LARGE HAIL
THREAT. THE LATEST HRRR INDICATED ACTIVITY IN OUR REGION SHOULD
BLOSSOM BETWEEN 2 AND 5 PM.
MORE ANALYSIS OF GUIDANCE WAS DESCRIBED IN THE PREVIOUS AFD WHICH
IS BELOW...
THE WARM SECTOR IS WELL ENTRENCHED ACROSS THE REGION AS METAR
DEWPOINTS WERE BETWEEN 65-70F AND VERY LITTLE IN THE WAY OF CLOUD
COVER. THIS WILL SET THE STAGE FOR AN ACTIVE WEATHER DAY ACROSS
THE REGION /AS ALREADY SEEN UPSTREAM WITH A LINE OF STRONG
CONVECTION UNDERWAY/ AS GOOD INSOLATION...HIGH MOISTURE CONTENT
AS PWATS CLIMB TO NEAR 2 INCHES...SBCAPES AT OR ABOVE 2K J/KG AND
DEEP LAYER SHEAR AROUND 30KTS /THE HIGHER VALUES ACROSS THE
NORTHERN PORTIONS OF THE REGION/ TO SUPPORT THE EXTENSION OF THE
SLIGHT RISK PER SPC COORDINATION ACROSS THE ENTIRE REGION. THE
MAIN THREAT REMAINS FROM DAMAGING WIND GUSTS AND/OR WET
MICROBURSTS GIVEN THE PRECIP LOADING IN A VERY MOIST COLUMN. HAIL
POTENTIAL LOOKS LOW AT THIS TIME AS WET BULB FREEZING LEVELS PER
THE BUFR PROFILES ARE EXPECTED AT OR ABOVE 13K FEET. WE WILL
RETAIN THE ENHANCED WORDING FOR HEAVY RAINFALL AND GUSTY WINDS IN
THE GRIDS ALONG WITH THE STRONGLY WORDED HWO. NCEP MODEL SUITE IS
IN GOOD AGREEMENT WITH THE TIMING OF THE FROPA WHICH REACHES OUR
DACKS REGION AROUND THE LUNCH HOUR...CAPITAL REGION BETWEEN 2PM-
4PM...AND THE MID HUDSON VALLEY AND NW CT BETWEEN 5PM-8PM.
IN THE WAKE OF FROPA...WINDS SHIFT TO WEST AND NORTHWEST BEFORE
MIDNIGHT. HOWEVER...A WAVE IS EXPECTED TO DEVELOP ALONG THE
BOUNDARY WHICH WILL SLOW DOWN THE FORWARD PROGRESS SOMEWHAT TO
KEEP CHC-SCT POPS SOUTH OF I90. WHILE THIS FROPA WILL USHER IN
MORE STABLE AND LESS HUMID CONDITIONS...LOW LEVEL MOISTURE CONTENT
REMAINS HIGH SO WE WILL RETAIN THE PARTLY-MOSTLY CLOUDY SKIES IN
THE FORECAST.
HIGHS TODAY WILL BE NEAR 90 IN MOST VALLEY LOCATIONS...WITH HEAT
INDICES INTO THE MID AND UPPER 90S. HIGHER TERRAIN WILL SEE HIGHS IN
THE MID TO UPPER 80S...EXCEPT COOLER ACROSS THE ADRIONDACKS WHERE
CLOUDS AND SHOWERS SHOULD KEEP HIGHS BELOW 80. A SOUTH WIND 5 TO 15
MPH WILL DO LITTLE TO STIFLE THE HEAT. HOWEVER...THE SHOWERS AND
THUNDERSTORMS WILL BEGIN TO COOL US DOWN AFTER 400 PM.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
A MORE STABLE...COOLER AND LESS HUMID AIR MASS ADVECTS INTO THE
REGION THURSDAY AND FRIDAY AS HIGH PRESSURE BUILDS INTO THE
REGION. RESIDUAL CLOUD COVER ACROSS THE REGION...ESPECIALLY ACROSS
THE SOUTHERN PORTIONS OF THE REGION...WILL MIX OUT TO PARTLY
CLOUDY/SUNNY CONDITIONS. CYCLONIC FLOW ALOFT REMAINS ALOFT A H850
TEMPS DIP BACK TO AROUND 10C. HIGHS THURSDAY WILL AVERAGE AT OR
JUST BELOW 80F FOR VALLEY LOCATIONS WITH THURSDAY NIGHT LOWS INTO
THE 50S WITH 40S ACROSS THE DACKS AND PORTIONS OF THE MOHAWK
VALLEY. HIGHS FRIDAY REBOUND BACK INTO THE LOWER 80S FOR VALLEY
LOCATIONS...MID-UPR 70S ELSEWHERE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PERIOD LOOKS RATHER UNSETTLED STARTING WITH THE SECOND
HALF OF THE WEEKEND.
FOR FRIDAY NIGHT AND SATURDAY EXPECT DRY AND SEASONABLE CONDITIONS
AS A RIDGE OF HIGH PRESSURE SLIDES OFF THE EASTERN SEABOARD. EXPECT
LOWS FRIDAY NIGHT IN THE 50S WITH HIGHS ON SATURDAY IN THE MID 70S
TO MID 80S.
START TO INCREASE POPS FROM SLIGHT CHANCE SATURDAY EVENING TO CHANCE
POPS LATE SATURDAY AS FA STARTS TO BE CONVERGED UPON BY SEVERAL LOW
PRESSURE SYSTEMS ONE PASSING THROUGH THE MID ATLANTIC REGION AND A
SECOND ONE PASSING THROUGH THE UPPER GREAT LAKES REGION. LOWS
SATURDAY NIGHT ARE EXPECTED TO BE IN THE MID 50S TO MID 60S.
SUNDAY THROUGH TUESDAY LOOKS TO BE ACTIVE AS THE SERIES OF LOW
PRESSURE SYSTEMS CONVERGE ACROSS THE NORTHEAST. TIMING AND LOCATION
OF INDIVIDUAL LOW PRESSURE SYSTEMS DIFFER AMONGST THE MODELS. SO AT
THIS POINT IN TIME WILL PLACE CHANCE POPS IN THE GRIDS THROUGH THE
PERIOD WITH MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.
HIGHS ARE EXPECTED TO RANGE FROM THE MID 70S TO MID 80S SUNDAY AND
MONDAY AND IN THE UPPER 60S TO UPPER 70S ON TUESDAY. LOWS ARE
EXPECTED TO BE IN THE MID 50S MID 60S.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
FOR TODAY...MAINLY VFR CONDITIONS...BUT SOME INTERMITTENT MVFR
CEILINGS AT KPSF FROM 12Z-14Z. SHOWERS AND THUNDERSTORMS WILL OCCUR
ACROSS THE AREA AS A COLD FRONT APPROACHES AND INTERACTS WITH THE
VERY WARM AND HUMID AIR MASS IN PLACE ACROSS THE REGION. THERE ARE
NOW INDICATIONS THAT THE FRONT WILL SLOW DOWN AS A WAVE OF LOW
PRESSURE MOVES NORTHEAST ALONG IT. HAVE USED PROB30 GROUPS FOR MVFR
CONDITIONS...BORDERING ON IFR...TO ADDRESS THE TIMING OF THE
CONVECTION...FOR THE LATE AFTERNOON INTO THE EVENING HOURS.
SOME STORMS MAY BECOME STRONG TO SEVERE DURING THE AFTERNOON AND
EVENING HOURS.
WE WILL START OFF WITH A SOUTH-SOUTHWEST WIND OF 5 TO 10 KNOTS TODAY
SHIFTING MORE TO THE WEST AND THEN NORTHWEST IN THE WAKE OF THE COLD
FRONT DURING THE EVENING HOURS.
OUTLOOK...
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. CHANCE OF SHRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
&&
.FIRE WEATHER...
SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE REGION TODAY ALONG
AND AHEAD OF A COLD FRONT. RELATIVELY HIGH MOISTURE CONTENT AHEAD
OF THIS BOUNDARY WILL KEEP RH VALUES AT OR ABOVE 50 PERCENT. THE
RH VALUES TONIGHT AT BETTER THAN 80 PERCENT.
THE SURFACE WIND WILL BE SOUTH TO SOUTHWEST THIS MORNING AT 5 TO 10
MPH...THEN BECOMING SOUTHWEST TO WEST MID DAY AT 5 TO 15 MPH WITH
SOME GUSTS TO 20 MPH. WINDS SHIFT TO A WEST THEN NORTHWEST
DIRECTION TONIGHT.
&&
.HYDROLOGY...
SHOWERS AND THUNDERSTORM WILL OCCUR ACROSS THE AREA AS A COLD
FRONT APPROACHES AND INTERACTS WITH THE VERY WARM AND HUMID AIR
MASS IN PLACE ACROSS THE REGION. PRECIPITABLE WATER VALUES ARE
EXPECTED TO INCREASE NEAR 2 INCHES...SO ANY STORM WILL CAPABLE OF
VERY HEAVY DOWNPOURS WHICH COULD CAUSE LOCALIZED FLOODING OF LOW
LYING AND POOR DRAINAGE AREAS. HAVE CONTINUED ENHANCED WORDING FOR
THE HEAVY RAINFALL TO THE FORECAST FOR THIS AFTERNOON AND EVENING
AND WILL RETAIN THIS MENTION IN OUR HAZARDOUS WEATHER OUTLOOK.
WITH THE PASSAGE OF THE COLD FRONT...A COOLER AND LESS HUMID AIR
WILL BE USHERED IN. EXPECTED SOME LINGERING SHOWERS INTO THURSDAY
MORNING AS THE FRONT WILL BE SLOW TO MOVE OFF TO THE EAST. THEN
LOOKING AT DRY WEATHER INTO AT LEAST THE FIRST HALF OF THE
WEEKEND. THE WEATHER WILL TURN UNSETTLED AS WE HEAD INTO THE
SECOND HALF OF THE WEEKEND AND INTO NEXT WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/BGM
NEAR TERM...HWJIV/BGM/NAS
SHORT TERM...BGM
LONG TERM...11
AVIATION...11
FIRE WEATHER...BGM
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS MIAMI FL
143 PM EDT WED JUL 23 2014
.AVIATION...
RADAR IS SHOWING SIGNS THAT CONVECTION IS FINALLY PUSHING TO THE
WEST OF THE EASTERN TAF SITES. HOWEVER, THERE ARE STILL A FEW
CONVECTIVE CELLS DEVELOPING ALONG THE COAST. SO HAVE PLACED TEMPO
FOR KPBI AND KFXE, AND LEFT VCTS IN FOR THE REMAINING EASTERN TAF
SITES FOR ANOTHER COUPLE OF HOURS. EXPECT MOSTLY VFR CONDITIONS,
EXCEPT WHEN THE SITES ARE BEING AFFECTED BY CONVECTIVE SHOWERS AND
THUNDERSTORMS THIS AFTERNOON. ONCE THEY MOVE OUT, CONDITIONS WILL
BE VFR THROUGH TOMORROW MORNING.
&&
.PREV DISCUSSION... /ISSUED 947 AM EDT WED JUL 23 2014/
UPDATE...
PLAN TO MAKE SOME ADJUSTMENTS TO THE POPS OVER AT LEAST THE
INTERIOR AS THEY SEEM A BIT HIGH BASED ON CURRENT TRENDS. WATER
VAPOR IMAGERY AND THE 12Z MFL SOUNDING BOTH SHOW SIGNIFICANT
DRYING HAS OCCURRED ABOVE THE 500MB LEVEL. HOWEVER, THE LOW LEVELS
REMAIN QUITE MOIST WITH A PWAT OF JUST UNDER 2 INCHES AND WITH
DIURNAL HEATING BEGINNING IN EARNEST THIS MORNING ALREADY HAVE
CONVECTION FIRING ACROSS THE EAST COAST METRO REGION. LOOKING AT
THE CONVECTIVE PARAMETERS, THE CAPE IS OVER 2000 J/KG, 500MB
TEMPERATURE WARMED TO 4.7C AND THE MID LEVEL LAPSE RATE IS NEAR
5.5C/KG. WITH THE EXCEPTION OF THE CAPE AND THE PWAT, THESE
NUMBERS ARE VERY UNIMPRESSIVE AND BELOW THE AVERAGE FOR MID/LATE
JULY. STILL, IT SEEMS THE HIGH PWAT AND CAPE ALONG WITH STRONG
DIURNAL HEATING WILL SOMEWHAT COUNTERACT THE OTHER LOW CONVECTIVE
ELEMENTS. THE HRRR HAS BEGUN TO SHOW LESS OVERALL COVERAGE OVER
THE INTERIOR FOR THIS AFTERNOON THAN THE 70-80% ORIGINALLY
ADVERTISED, SO WITH THE LESS THAN AMPLE PARAMETERS WILL ONLY LOWER
THE POPS SLIGHTLY UNTIL LATER TRENDS DICTATE OTHERWISE.
KOB
PREV DISCUSSION... /ISSUED 400 AM EDT WED JUL 23 2014/
SYNOPSIS...
SLIGHT DRIER AIR WILL MOVE INTO THE AREA THIS AFTERNOON AND
TONIGHT...AS HIGH PRESSURE BUILDS IN. THIS HIGH PRESSURE WILL
DOMINATE SOUTH FLORIDA WEATHER AT LEAST INTO EARLY NEXT WEEK.
SHORT TERM /TODAY THROUGH FRIDAY/...
HIGH PRESSURE CENTERED NORTH AND EAST OF THE BAHAMAS WILL
GRADUALLY STRENGTHEN TODAY...WITH DRIER AIR SPILLING NORTHWARD
INTO SOUTH FLORIDA THIS AFTERNOON AND TONIGHT. STILL PLENTY OF
MOISTURE FOR SEA-BREEZE TO INDUCE SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS...BUT COVERAGE WILL BE LESS THAN PREVIOUS FEW
DAYS...ESPECIALLY OVER EAST COAST URBAN AREAS WHERE DRY AIR WILL
BE FIRST TO REACH. THIS DRIER THAN NORMAL AIRMASS WILL REMAIN OVER
SOUTH FLORIDA THROUGH THE SHORT TERM...AS RIDGE AXIS ORIENTS OVER
THE PENINSULA. RAIN CHANCES WILL BE LOWER THAN NORMAL BOTH
THURSDAY AND FRIDAY...AND SHOULD BE MOSTLY FOCUSED OVER THE
INTERIOR WHERE SEA-BREEZES INTERACT.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
DEEP LAYER RIDGE WILL STRENGTHEN FURTHER OVER THE WEEKEND.
SCATTERED DAYTIME SHOWERS AND THUNDERSTORMS WILL STILL BE
POSSIBLE...BUT ACTIVITY WILL BE LESS WIDESPREAD THAN TYPICAL OF
LATE JULY RAINY SEASON. EARLY NEXT WEEK...AN UPPER LEVEL TROUGH
AND ASSOCIATED COLD FRONT WILL DIG INTO THE DEEP SOUTH AND
SOUTHEAST CONUS. AFOREMENTIONED HIGH PRESSURE SHOULD KEEP THESE
FEATURES FROM HAVING MUCH IMPACT ON SOUTH FLORIDA...BUT OVERALL
WINDS BECOMING MORE SOUTHERLY/SOUTHWESTERLY...AS OPPOSED TO
SOUTHEAST...MAY ALLOW FOR CONVECTION TO SPREAD TOWARD EAST COAST
MORE. SLIGHTLY WARMER TEMPERATURES COULD ALSO RESULT.
MARINE...
HIGH PRESSURE BUILDING OVER THE WATERS WILL RESULT LIGHT
WINDS...SOUTH AT 10 KTS OR LESS...AND SEAS OF 2 FEET OR
LESS...THROUGH THE WEEKEND. THUNDERSTORMS WILL BE LESS WIDESPREAD
THAN PREVIOUS FEW DAYS...BUT SCATTERED ACTIVITY IS STILL POSSIBLE
THROUGHOUT THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 90 78 90 / 10 20 10 30
FORT LAUDERDALE 80 90 81 91 / 10 30 10 30
MIAMI 79 91 78 91 / 20 30 10 30
NAPLES 76 91 77 92 / 20 30 20 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...30/KOB
LONG TERM....23/SK
AVIATION...13/SI
AREA FORECAST DISCUSSION
NWS MIAMI FL
947 AM EDT WED JUL 23 2014
.UPDATE...
PLAN TO MAKE SOME ADJUSTMENTS TO THE POPS OVER AT LEAST THE
INTERIOR AS THEY SEEM A BIT HIGH BASED ON CURRENT TRENDS. WATER
VAPOR IMAGERY AND THE 12Z MFL SOUNDING BOTH SHOW SIGNIFICANT
DRYING HAS OCCURRED ABOVE THE 500MB LEVEL. HOWEVER, THE LOW LEVELS
REMAIN QUITE MOIST WITH A PWAT OF JUST UNDER 2 INCHES AND WITH
DIURNAL HEATING BEGINNING IN EARNEST THIS MORNING ALREADY HAVE
CONVECTION FIRING ACROSS THE EAST COAST METRO REGION. LOOKING AT
THE CONVECTIVE PARAMETERS, THE CAPE IS OVER 2000 J/KG, 500MB
TEMPERATURE WARMED TO 4.7C AND THE MID LEVEL LAPSE RATE IS NEAR
5.5C/KG. WITH THE EXCEPTION OF THE CAPE AND THE PWAT, THESE
NUMBERS ARE VERY UNIMPRESSIVE AND BELOW THE AVERAGE FOR MID/LATE
JULY. STILL, IT SEEMS THE HIGH PWAT AND CAPE ALONG WITH STRONG
DIURNAL HEATING WILL SOMEWHAT COUNTERACT THE OTHER LOW CONVECTIVE
ELEMENTS. THE HRRR HAS BEGUN TO SHOW LESS OVERALL COVERAGE OVER
THE INTERIOR FOR THIS AFTERNOON THAN THE 70-80% ORIGINALLY
ADVERTISED, SO WITH THE LESS THAN AMPLE PARAMETERS WILL ONLY LOWER
THE POPS SLIGHTLY UNTIL LATER TRENDS DICTATE OTHERWISE.
KOB
&&
.PREV DISCUSSION... /ISSUED 740 AM EDT WED JUL 23 2014/
AVIATION...
HIGH PRESSURE IS SLOWLY BEGINNING TO BUILD OVER THE AREA FROM THE
EAST. THIS WILL KEEP A SOUTH TO SOUTHEAST FLOW OVER SOUTH FLORIDA.
THIS WILL ALSO HELP TO PUSH SHOWERS AND THUNDERSTORMS INTO THE
INTERIOR BY THE EARLY AFTERNOON. DID KEEP VCTS IN THE TAFS UNTIL
AROUND 10Z FOR THE EASTERN TAF LOCATIONS. KAPF MAY SEE A LONGER
DURATION OF IMPACT FROM CONVECTION, SO KEPT THE VCTS IN UNTIL
23Z. SO, GENERALLY VFR CONDITIONS WITH BRIEF IFR POSSIBLE DUE TO
ANY SHOWERS AND OR THUNDERSTORMS THAT MOVE OVER THE TAF SITES. THE
WIND WILL GO LIGHT AND VARIABLE ONCE AGAIN, BY LATE EVENING.
PREV DISCUSSION... /ISSUED 400 AM EDT WED JUL 23 2014/
SYNOPSIS...
SLIGHT DRIER AIR WILL MOVE INTO THE AREA THIS AFTERNOON AND
TONIGHT...AS HIGH PRESSURE BUILDS IN. THIS HIGH PRESSURE WILL
DOMINATE SOUTH FLORIDA WEATHER AT LEAST INTO EARLY NEXT WEEK.
SHORT TERM /TODAY THROUGH FRIDAY/...
HIGH PRESSURE CENTERED NORTH AND EAST OF THE BAHAMAS WILL
GRADUALLY STRENGTHEN TODAY...WITH DRIER AIR SPILLING NORTHWARD
INTO SOUTH FLORIDA THIS AFTERNOON AND TONIGHT. STILL PLENTY OF
MOISTURE FOR SEA-BREEZE TO INDUCE SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS...BUT COVERAGE WILL BE LESS THAN PREVIOUS FEW
DAYS...ESPECIALLY OVER EAST COAST URBAN AREAS WHERE DRY AIR WILL
BE FIRST TO REACH. THIS DRIER THAN NORMAL AIRMASS WILL REMAIN OVER
SOUTH FLORIDA THROUGH THE SHORT TERM...AS RIDGE AXIS ORIENTS OVER
THE PENINSULA. RAIN CHANCES WILL BE LOWER THAN NORMAL BOTH
THURSDAY AND FRIDAY...AND SHOULD BE MOSTLY FOCUSED OVER THE
INTERIOR WHERE SEA-BREEZES INTERACT.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
DEEP LAYER RIDGE WILL STRENGTHEN FURTHER OVER THE WEEKEND.
SCATTERED DAYTIME SHOWERS AND THUNDERSTORMS WILL STILL BE
POSSIBLE...BUT ACTIVITY WILL BE LESS WIDESPREAD THAN TYPICAL OF
LATE JULY RAINY SEASON. EARLY NEXT WEEK...AN UPPER LEVEL TROUGH
AND ASSOCIATED COLD FRONT WILL DIG INTO THE DEEP SOUTH AND
SOUTHEAST CONUS. AFOREMENTIONED HIGH PRESSURE SHOULD KEEP THESE
FEATURES FROM HAVING MUCH IMPACT ON SOUTH FLORIDA...BUT OVERALL
WINDS BECOMING MORE SOUTHERLY/SOUTHWESTERLY...AS OPPOSED TO
SOUTHEAST...MAY ALLOW FOR CONVECTION TO SPREAD TOWARD EAST COAST
MORE. SLIGHTLY WARMER TEMPERATURES COULD ALSO RESULT.
MARINE...
HIGH PRESSURE BUILDING OVER THE WATERS WILL RESULT LIGHT
WINDS...SOUTH AT 10 KTS OR LESS...AND SEAS OF 2 FEET OR
LESS...THROUGH THE WEEKEND. THUNDERSTORMS WILL BE LESS WIDESPREAD
THAN PREVIOUS FEW DAYS...BUT SCATTERED ACTIVITY IS STILL POSSIBLE
THROUGHOUT THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 90 77 90 78 / 40 10 20 10
FORT LAUDERDALE 89 80 90 81 / 30 10 30 10
MIAMI 91 79 91 78 / 40 20 30 10
NAPLES 91 76 91 77 / 40 20 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
146 AM EDT WED JUL 23 2014
.AVIATION...
THE WINDS WILL BE LIGHT OVER SOUTH FLORIDA TAF SITES EARLY THIS
MORNING BEFORE BECOMING EASTERLY AT 5 TO 10 KNOTS AFTER 15Z TODAY.
THE ONLY EXCEPTION TO THIS IS AT KAPF TAF SITE WITH THE WIND FLOW
WILL BE WESTERLY AFTER 16Z DUE TO THE WEST COAST SEA BREEZE
PUSHING INLAND. DRIER AIR IS STARTING TO WORK INTO SOUTH FLORIDA
EARLY THIS MORNING...BUT THERE WILL BE ENOUGH MOISTURE AROUND TO
ALLOW FOR THUNDERSTORMS TO DEVELOP ALONG BOTH SEA BREEZE TODAY.
THEREFORE...THE VCTS WILL REMAIN IN PLACE FOR ALL OF THE SOUTH
FLORIDA TAF SITES AFTER 15Z TODAY.
AT THIS TIME...THE TIMING OF THE SHOWERS AND THUNDERSTORMS TO
AFFECT THE TAF SITES IS UNKNOWN. THEREFORE...THE CEILING AND VIS
WILL REMAIN IN VFR CONDITIONS FOR TODAY FOR ALL OF THE TAF SITES.
HOWEVER...WHEN THE THUNDERSTORMS DO DEVELOP AROUND THE TAF SITES
THEN A TEMPO GROUP WILL BE ADDED FOR THE CEILING AND VIS.
&&
.AVIATION...54/BNB
.PREV DISCUSSION... /ISSUED 937 PM EDT TUE JUL 22 2014/
UPDATE...
THE AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY DIMINISHED EARLIER
WITH VERY QUIET CONDITIONS EXPECTED TO PERSIST INTO THE OVERNIGHT
HOURS. THE LATEST HRRR MODEL RUN REFLECTS THIS
TREND...HOWEVER...DOES INDICATE SOME ISLTD/SCT ACTIVITY DEVELOPING
OVER THE ADJACENT ATLANTIC WATERS BY DAYBREAK WEDNESDAY. OVERNIGHT
TEMPERATURES ARE PROJECTED TO DIP INTO THE MID TO UPPER 70S ACROSS
THE LOCAL AREA FOR THE LOWS. OUTSIDE OF A FEW MINOR
ADJUSTMENTS...THE PREVIOUS FORECAST PACKAGE REMAINS ON TRACK THIS
EVENING WITH NO MAJOR UPDATES ANTICIPATED.
&&
85/AG
PREV DISCUSSION... /ISSUED 738 PM EDT TUE JUL 22 2014/
AVIATION...
MAINLY VFR CONDITIONS TO PREVAIL OVER THE NEXT 24 HOURS AT ALL
SITES OUTSIDE OF ANY THUNDERSTORMS. WINDS SHOULD BE MAINLY LIGHT
AND VARIABLE THROUGH THE NIGHT BEFORE SOUTHEASTERLY FLOW RETURNS
TOMORROW AFTERNOON. PLACED VCTS IN AT ALL SITES AFTER 15Z-16Z
TOMORROW ALTHOUGH BELIEVE MOST OF THE CONVECTION WILL REMAIN
ACROSS THE INTERIOR AND GULF COAST AS A GULF BREEZE SHOULD
DEVELOP.
**
PREV DISCUSSION... /ISSUED 230 PM EDT TUE JUL 22 2014/
DISCUSSION...
THE WEATHER PATTERN HAS NOT CHANGED MUCH FROM YESTERDAY. A LOW
PRESSURE CENTER IS SITTING OVER THE MOBILE ALABAMA AREA, AND AN
AREA OF HIGH PRESSURE IS SITUATED TO THE EAST. THIS HAS CONTINUED
THE SOUTHERLY FLOW OVER SOUTH FLORIDA, WHICH HAS MAINTAINED
ABUNDANT MOISTURE AND ENOUGH INSTABILITY TO BRING SHOWERS AND
THUNDERSTORMS TO THE AREA. THE CONVECTIVE ACTIVITY SHOULD DWINDLE
THROUGH THE EVENING HOURS, WITH THE LOSS OF DAYTIME HEATING.
MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE LOW WEAKENING AND THE
HIGH STRENGTHENING SOMEWHAT AND BUILDING SLOWLY WESTWARD. THIS
WILL KEEP A GENERALLY SOUTHERLY FLOW OVER SOUTH FLORIDA. WHILE
TOMORROW WILL SEE ANOTHER ROUND OF WIDESPREAD ACTIVITY, THURSDAY
AND FRIDAY LOOK TO BE MORE TOWARDS THE INTERIOR, WITH SLIGHTLY
LOWER PROBABILITY EACH DAY, AS THE LOW SLOWLY WEAKENS AND THE HIGH
GRADUALLY BUILDS.
LONG TERM...
BERMUDA RIDGE AND RELATIVELY DRY ATLANTIC AIR WILL REGULATE
WEATHER THROUGH THE WEEKEND...RESULTING IN A BIT BELOW NORMAL RAIN
CHANCES...HIGHEST OVER INTERIOR DURING THE AFTERNOONS. MAXIMA WILL
BE NEAR AVERAGE FOR LATE JULY...MAINLY LOWER 90S...WITH MINIMA A
FEW DEGREES ABOVE NORMAL...RANGING FROM MID 70S TO AROUND 80F
ALONG THE ATLANTIC COAST.
MARINE...
HIGH PRESSURE WILL SLOWLY BUILD OVER THE ATLANTIC WATERS. WITH
THE CENTER OF THE HIGH TO THE EAST OF THE AREA, SOUTHERLY FLOW
WILL CONTINUE THROUGH THE REST OF THE WEEK. WITH THE FLOW BEING
RELATIVELY LIGHT, SEAS ARE NOT EXPECTED TO BUILD OVER THE NEXT
FEW DAYS. HOWEVER, THUNDERSTORMS MAY PRODUCE LOCALLY ROUGH
CONDITIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 78 91 79 91 / 20 30 30 30
FORT LAUDERDALE 82 91 82 91 / 20 20 20 30
MIAMI 80 91 80 91 / 20 30 20 30
NAPLES 76 92 77 92 / 20 40 20 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...30/KOB
LONG TERM....13/SI
AVIATION...54/BNB
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
138 PM EDT WED JUL 23 2014
.PREV DISCUSSION... /ISSUED 1052 AM EDT WED JUL 23 2014/
UPDATE...
UPPER LOW CONTINUES ACROSS THE LA COAST THIS MORNING. AT THE
SURFACE...A WEAK BOUNDARY REMAINS ACROSS SOUTHERN GA. REGIONAL
RADAR TRENDS SHOW SOME ISOLD SHOWERS DEVELOPING ACROSS THE
NORTHERN METRO AREA. LATEST RUNS OF THE HRRR LOOK PRETTY GOOD WITH
THE HIGHEST POPS ACROSS THE NORTHERN HALF OF THE CWFA THIS
AFTERNOON...WITH COVERAGE OF STORMS REMAINING ISOLD TO SCT. 12Z
SOUNDING SHOWS HIGH PWATS AND BL WINDS BELOW 15KT...SO ANY STORMS
THAT DEVELOP WILL BE SLOW MOVERS AND CAPABLE OF PRODUCING LOCALLY
HEAVY RAINFALL.
PREV DISCUSSION... /ISSUED 727 AM EDT WED JUL 23 2014/
SHORT TERM /TODAY THROUGH THURSDAY/...
/ISSUED AT 503 AM EDT WED JUL 23 2014/
MODELS CONTINUE IN GOOD AGREEMENT THROUGH THE SHORT TERM. WIDELY
SCATTERED SHOWERS CONTINUE ACROSS MAINLY NORTH GA EARLY THIS MORNING
AND WHILE THIS WILL DIMINISH TOWARD SUNRISE...EXPECT CONVECTION TO
INCREASE AGAIN LATE THIS MORNING AND AFTERNOON. THE BEST CHANCES
WILL BE ACROSS NORTH GA. A SHORT WAVE WILL MOVE INTO THE CWA
THURSDAY ALONG WITH AN ASSOCIATED WEAK FRONT. THIS WILL BE ENOUGH TO
INCREASE CHANCES OF TSTORMS TO HIGH CHANCE TO LIKELY ACROSS THE
CWA...MAINLY DURING THE AFTERNOON ON THURSDAY. AT THIS TIME WE DO
NOT EXPECT SEVERE THUNDERSTORMS THURSDAY...HOWEVER BRIEF HEAVY RAIN
IS POSSIBLE.
17
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
/ISSUED AT 503 AM EDT WED JUL 23 2014/
ACTIVE PATTERN IS EXPECTED TO CONTINUE THROUGH THE EXTENDED
PERIODS WITH SEVERAL FEATURES IMPACTING THE AREA...BUT MODELS ARE
IN BETTER AGREEMENT WITH SHOWING RELATIVELY QUIET PERIODS IN
BETWEEN. HAVE ACTUALLY DECREASED POPS SLIGHTLY FRIDAY AND INTO THE
WEEKEND BEHIND THE AFOREMENTIONED FRONT. ALTHOUGH SEVERAL MODELS
PUSH THE FRONT THROUGH THE ENTIRE CWA BY SATURDAY...THERE IS STILL
SOME UNCERTAINTY REGARDING THE POSITION OF THE FRONT AND
ASSOCIATED MOISTURE ACROSS SOUTH GEORGIA. AS A RESULT...HAVE
CONTINUED MENTION OF CHANCE POPS ACROSS THE FAR SOUTH AND
SOUTHEAST CWA ON SATURDAY. MOISTURE RETURNS TO THE AREA SUNDAY AS
NEXT SHORTWAVE APPROACHES AND LONGWAVE TROUGH STARTS TO SET UP
OVER THE EASTERN UNITED STATES. CHANCE POPS SUNDAY CONTINUE INTO
EARLY WEEK AND THEN EXIT QUICKLY LATE MONDAY AS SECOND FRONT
PUSHES THROUGH. LONGWAVE TROUGH MAINTAINS ITS POSITION OVER THE
EASTERN U.S. THROUGH MID WEEK...AND WITH SURFACE HIGH ACROSS THE
AREA BEHIND THE FRONT...LOWER PRECIP CHANCES AND COOLER
TEMPERATURES ARE IN STORE.
IN GENERAL...EXPECT A SLIGHT WARMING TREND OVER THE WEEKEND...THEN
BACK TO NEAR NORMAL OR SLIGHTLY BELOW NORMAL TEMPERATURES WITH THE
SECOND FRONT EARLY NEXT WEEK.
31
&&
.AVIATION...
18Z UPDATE...
SCATTERED SHOWERS HAVE DEVELOPED ACROSS NORTHERN GA THIS
AFTERNOON. BETTER COVERAGE SHOULD BE UP TO THE NORTH...BUT ENOUGH
CONFIDENCE THAT THERE WILL BE ENOUGH CELLS IN THE VICINITY OF ATL.
MODELS ARE NOT PROGGING IFR/LIFR CIGS OVERNIGHT. DO THINK THAT
THERE WILL BE ENOUGH LOW LEVEL MOISTURE FOR SOME SCT MVFR CIGS
THO. A COLD FRONT WILL MOVE THROUGH ON THURSDAY...WITH BETTER
COVERAGE OF PRECIPITATION.
//ATL CONFIDENCE...18Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 70 89 70 / 30 20 60 30
ATLANTA 88 71 87 71 / 30 20 60 30
BLAIRSVILLE 80 66 82 64 / 40 30 60 20
CARTERSVILLE 87 69 87 68 / 40 30 60 20
COLUMBUS 91 72 90 73 / 30 20 60 30
GAINESVILLE 86 70 87 69 / 40 20 60 20
MACON 91 72 91 72 / 30 20 60 30
ROME 87 70 87 68 / 50 30 60 20
PEACHTREE CITY 89 70 87 69 / 30 20 60 30
VIDALIA 93 74 94 74 / 30 20 60 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1052 AM EDT WED JUL 23 2014
.UPDATE...
UPPER LOW CONTINUES ACROSS THE LA COAST THIS MORNING. AT THE
SURFACE...A WEAK BOUNDARY REMAINS ACROSS SOUTHERN GA. REGIONAL
RADAR TRENDS SHOW SOME ISOLD SHOWERS DEVELOPING ACROSS THE
NORTHERN METRO AREA. LATEST RUNS OF THE HRRR LOOK PRETTY GOOD WITH
THE HIGHEST POPS ACROSS THE NORTHERN HALF OF THE CWFA THIS
AFTERNOON...WITH COVERAGE OF STORMS REMAINING ISOLD TO SCT. 12Z
SOUNDING SHOWS HIGH PWATS AND BL WINDS BELOW 15KT...SO ANY STORMS
THAT DEVELOP WILL BE SLOW MOVERS AND CAPABLE OF PRODUCING LOCALLY
HEAVY RAINFALL.
&&
.PREV DISCUSSION... /ISSUED 727 AM EDT WED JUL 23 2014/
SHORT TERM /TODAY THROUGH THURSDAY/...
/ISSUED AT 503 AM EDT WED JUL 23 2014/
MODELS CONTINUE IN GOOD AGREEMENT THROUGH THE SHORT TERM. WIDELY
SCATTERED SHOWERS CONTINUE ACROSS MAINLY NORTH GA EARLY THIS MORNING
AND WHILE THIS WILL DIMINISH TOWARD SUNRISE...EXPECT CONVECTION TO
INCREASE AGAIN LATE THIS MORNING AND AFTERNOON. THE BEST CHANCES
WILL BE ACROSS NORTH GA. A SHORT WAVE WILL MOVE INTO THE CWA
THURSDAY ALONG WITH AN ASSOCIATED WEAK FRONT. THIS WILL BE ENOUGH TO
INCREASE CHANCES OF TSTORMS TO HIGH CHANCE TO LIKELY ACROSS THE
CWA...MAINLY DURING THE AFTERNOON ON THURSDAY. AT THIS TIME WE DO
NOT EXPECT SEVERE THUNDERSTORMS THURSDAY...HOWEVER BRIEF HEAVY RAIN
IS POSSIBLE.
17
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
/ISSUED AT 503 AM EDT WED JUL 23 2014/
ACTIVE PATTERN IS EXPECTED TO CONTINUE THROUGH THE EXTENDED
PERIODS WITH SEVERAL FEATURES IMPACTING THE AREA...BUT MODELS ARE
IN BETTER AGREEMENT WITH SHOWING RELATIVELY QUIET PERIODS IN
BETWEEN. HAVE ACTUALLY DECREASED POPS SLIGHTLY FRIDAY AND INTO THE
WEEKEND BEHIND THE AFOREMENTIONED FRONT. ALTHOUGH SEVERAL MODELS
PUSH THE FRONT THROUGH THE ENTIRE CWA BY SATURDAY...THERE IS STILL
SOME UNCERTAINTY REGARDING THE POSITION OF THE FRONT AND
ASSOCIATED MOISTURE ACROSS SOUTH GEORGIA. AS A RESULT...HAVE
CONTINUED MENTION OF CHANCE POPS ACROSS THE FAR SOUTH AND
SOUTHEAST CWA ON SATURDAY. MOISTURE RETURNS TO THE AREA SUNDAY AS
NEXT SHORTWAVE APPROACHES AND LONGWAVE TROUGH STARTS TO SET UP
OVER THE EASTERN UNITED STATES. CHANCE POPS SUNDAY CONTINUE INTO
EARLY WEEK AND THEN EXIT QUICKLY LATE MONDAY AS SECOND FRONT
PUSHES THROUGH. LONGWAVE TROUGH MAINTAINS ITS POSITION OVER THE
EASTERN U.S. THROUGH MID WEEK...AND WITH SURFACE HIGH ACROSS THE
AREA BEHIND THE FRONT...LOWER PRECIP CHANCES AND COOLER
TEMPERATURES ARE IN STORE.
IN GENERAL...EXPECT A SLIGHT WARMING TREND OVER THE WEEKEND...THEN
BACK TO NEAR NORMAL OR SLIGHTLY BELOW NORMAL TEMPERATURES WITH THE
SECOND FRONT EARLY NEXT WEEK.
31
AVIATION...
12Z UPDATE...
SCATTERED SHOWERS CONTINUE ACROSS PARTS OF NORTH GA. SHOWERS WILL
CONTINUE TO DEVELOP ACROSS NORTH GEORGIA THROUGH THE MORNING WITH
THUNDER DEVELOPING LATE THIS MORNING/AFTERNOON...MAINLY ACROSS NORTH
GA. THE CONVECTION WILL DIMINISH LATE THIS EVENING. VFR SKIES
CURRENTLY OVER THE TAF SITES AND EXPECT VFR CONDITIONS TO PREVAIL
THROUGH THIS EVENING. WINDS ARE CURRENTLY LIGHT AND VARIABLE...BUT
WITH MIXING THEY WILL COME AROUND TO THE WEST BUT REMAIN LIGHT IN
SPEED.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM TO HIGH ON ALL ELEMENTS.
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 70 89 70 / 30 30 60 40
ATLANTA 88 71 87 71 / 30 30 60 20
BLAIRSVILLE 80 66 82 64 / 40 40 60 20
CARTERSVILLE 87 69 87 68 / 40 40 60 20
COLUMBUS 91 72 90 73 / 30 20 60 30
GAINESVILLE 86 70 87 69 / 40 30 60 30
MACON 91 72 91 72 / 30 20 60 40
ROME 87 70 87 68 / 50 40 60 10
PEACHTREE CITY 89 70 87 69 / 30 20 60 30
VIDALIA 93 74 94 74 / 30 20 30 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
126 AM EDT WED JUL 23 2014
.SYNOPSIS...
ISSUED AT 727 PM EDT TUE JUL 22 2014
A COLD FRONT WILL MOVE ACROSS THE REGION OVERNIGHT INTO WEDNESDAY
MORNING. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ALONG THE
FRONT AS IT PASSES THROUGH THE AREA. COOLER AND DRIER AIR WILL
FILTER IN BEHIND THE FRONT FOR WEDNESDAY THROUGH THE END OF THE
WEEK. LOWS TONIGHT WILL BE IN THE MID 60S TO AROUND 70 DEGREES WITH
HIGHS ON WEDNESDAY IN THE 70S.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 306 PM EDT TUE JUL 22 2014
REGIONAL RADARS SHOWING ONGOING CONVECTION CONTINUES TO MOVE ACROSS
FAR NORTHERN GREAT LAKES/SOUTHERN CANADA WITH SURFACE LOW WHILE
EARLIER MCS DISSIPATING OVER THE MID MISSISSIPPI VALLEY WITH NEW
CELLS STARTING TO FORM OVER IOWA THIS AFTERNOON. WATER VAPOR IMAGERY
AND LATEST RUC ANALYSIS SHOWS SHORT WAVE TROF MOVING ACROSS LAKE
SUPERIOR WITH UPPER JET WELL TO THE NORTH OVER THE HUDSON BAY. THIS
DETACHMENT OF UPPER FORCING WILL BE PROBLEMATIC FOR CONVECTION
MAINTAINING ALONG THE COLD FRONT AS IT MOVES THROUGH OVERNIGHT. BEST
CHANCES APPEAR TO BE IN THE NW CWA AS DECENT MASS CONVERGENCE ALONG
COLD FRONT WILL COMBINE WITH MODEST ELEVATED INSTABILITY...CAPES
AROUND 1500J/KG...SO IF CONVECTION IN IOWA IS ABLE TO BECOME MORE
ORGANIZED IT MAY HAVE ENOUGH SUPPORT TO MAINTAIN CONVECTIVE
COMPLEX...HOWEVER FORMING RIGHT ALONG THICKNESS RIDGE WILL HAVE SOME
UNCERTAINTY IN ITS FORWARD PROPAGATION. FRONT EXPECTED TO PUSH
THROUGH MUCH OF THE CWA BY WEDNESDAY MORNING WITH JUST LINGERING
CHANCES IN THE FAR SE CWA...TRENDING TOWARD A DRY FORECAST FOR THE
ENTIRE AREA BY AFTERNOON. WARM AND MUGGY CONDITIONS EXPECTED TONIGHT
FOR THE SE HALF WITH LOWS AROUND 70 WHILE FRONTAL PASSAGE WILL ALLOW
TEMPS TO DROP INTO THE MID 60S NW. COOLER AND LESS HUMID FOR
WEDNESDAY WITH HIGHS 75-80.
&&
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 306 PM EDT TUE JUL 22 2014
COMFORTABLE/FAIR WX WILL PREVAIL WEDNESDAY NIGHT THROUGH FRIDAY
MORNING AS STABLE CANADIAN HIGH PRESSURE DROPS THROUGH. MID-UPPER
LEVEL FLOW WILL BRIEFLY TRANSITION TO A FLATTER/SEMI-ZONAL WNW
REGIME BY LATE FRIDAY INTO SATURDAY...WHILE IN THE LOW LEVELS WINDS
VEER MORE SOUTHERLY ALLOWING AN ACTIVE WARM FRONT TO WORK ENE INTO
THE REGION. LEAD/WEAK SHORTWAVE IN ADVANCE OF PRIMARY SHORTWAVE
TROUGH AND INCREASING MASS/MOISTURE CONVERGENCE ALONG THE DEVELOPING
FRONT SUPPORT INHERITED CHANCE POPS FOR SHOWERS/STORMS DURING THIS
TIME...MAINLY LATER FRIDAY NIGHT INTO SATURDAY.
RE-AMPLIFICATION OF EASTERN CONUS TROUGH REMAINS A CONSISTENT SIGNAL
IN MODEL GUIDANCE SUNDAY INTO EARLY NEXT WEEK. COLD FRONT ON LEADING
EDGE OF HEIGHT FALLS MAY SUPPORT ANOTHER ROUND OF CONVECTION LATER
SATURDAY NIGHT-SUNDAY DEPENDING ON TIMING. UNSEASONABLY COOL AND
MAINLY DRY WX LIKELY RETURNS EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 112 AM EDT WED JUL 23 2014
TSRA WHICH DEVELOPED ALONG THE CDFNT THIS EVE MOVG INTO NWRN
INDIANA ATTM. WILL CONT TEMPO TSRA MENTION INTO FOR NEXT COUPLE OF
HOURS AT SBN... ALSO ADDED TSRA TO FWA FROM 07-09Z... THOUGH CONFIDENCE
NOT AS HIGH FOR THIS TERMINAL AS STORMS MOVING INTO AN AREA WITH
HIGHER CIN. CDFNT STILL EXPECTED TO MOVE THROUGH THE AREA EARLY
THIS MORNING WITH BRISK N-NW WINDS DEVELOPING BEHIND IT. SOME MVFR
CIGS BEHIND THE FRONT OVER NRN MI SHOULD MOVE THROUGH NRN INDIANA
DURING THE MORNING WITH CIGS SCATTERING OUT IN THE AFTN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT THROUGH THURSDAY MORNING FOR INZ003.
MI...BEACH HAZARDS STATEMENT THROUGH THURSDAY MORNING FOR MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THURSDAY FOR LMZ043-046.
&&
$$
SYNOPSIS...OBERGFELL
SHORT TERM...JAL
LONG TERM...STEINWEDEL
AVIATION...JT
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1237 AM EDT WED JUL 23 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 226 PM EDT TUE JUL 22 2014
THE CURRENT UPPER RIDGE BRIDGING FROM THE WEST ACROSS THE GREAT
LAKES WILL RETROGRADE WESTWARD. A SERIES OF MINOR LOW PRESSURE
TROUGHS TOP THE REBUILDING WESTERN US RIDGE TO REDEVELOP THE
EASTERN TROUGH NEXT WEEK. THIS MEANS A RETURN TO COOLER AND LESS
HUMID WEATHER.
AN INITIAL FRONTAL BOUNDARY WILL SWEEP ACROSS CENTRAL INDIANA
WEDNESDAY FOLLOWED BY RESORT LIKE HIGH PRESSURE FOR THURSDAY AND
FRIDAY. THE SERIES OF LOW PRESSURE SYSTEMS TOPPING THE RIDGE WILL
PRODUCE PERIODS OF THUNDERSTORM FRIDAY NIGHT INTO MONDAY OR
TUESDAY BEFORE ANOTHER DRY-OUT AND COOL DOWN WITH LOWS IN THE 50S
AND HIGHS IN THE 70S BY MID-WEEK NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 1050 PM EDT TUE JUL 22 2014
BASED ON EVENING CONVECTIVE/RADAR TRENDS AND HRRR GUIDANCE...HAVE
PUSHED POPS BACK SEVERAL HOURS AND LOWERED THEM. STRONGEST
CONVECTION ONGOING ACROSS LAKE MICHIGAN AND NORTHERN ILLINOIS
WHERE DYNAMICS ARE STRONGER. THIS ACTIVITY MAY BE ABLE TO EXPAND
ENOUGH TO IMPACT NORTHWESTERN FORECAST AREA LATER TONIGHT...BUT
THIS IS FAR FROM CERTAIN. PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 226 PM EDT TUE JUL 22 2014
ISSUE OF CONCERN IS STORM POTENTIAL TONIGHT. CURRENT WARM CAP ALOFT
MAY HELP INHIBIT WHATEVER CONVECTION DEVELOPS THIS EVENING OUT WEST.
COMBINED WITH OVERNIGHT STORM ARRIVAL AND STABILIZING TEMPS AND
STRONGEST FORCING REMAINING IN THE GREAT LAKES...EXPECT
DIMINISHING LINE OF STORMS/SHOWERS TO MOVE TO NEAR I-70 BY DAYBREAK
WEDNESDAY. WITH DEWPOINTS LIKELY TO CLIMB TO THE LOWER 70S AHEAD
OF THE FRONT...MIN TEMPS SHOULD BE NEAR 70 EXCEPT WHERE ANY HEAVY
DOWNPOURS DROP MINS TO UPPER 60S. WIDESPREAD RAIN IS UNCERTAIN BUT
LOCAL HALF INCH DOWNPOURS CAN BE EXPECTED WITH THE STRONGER
STORMS. SOME POTENTIAL FOR GUSTINESS WITH THESE STRONGER STORMS
BUT THESE SHOULD STAY BELOW SEVERE LIMITS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 226 PM EDT TUE JUL 22 2014
WEDNESDAY...ISSUE IS HOW LONG RAIN THREAT LINGERS AND POTENTIAL
FOR SEVERE. MODELS DIFFER SLIGHTLY ON TIMING BUT CLOSE ENOUGH TO
BLEND FOR GOOD FORECAST.
INITIAL THRUST OF CONVECTION SHOULD SAG SLOWLY SOUTH DURING
MORNING HOURS AHEAD OF WIND SHIFT/FRONTAL BOUNDARY. LOCATIONS
NORTHWEST OF A TERRE HAUTE TO MUNCIE LINE WILL LIKELY HAVE
ALREADY SEEN RAIN THREAT ENDED. SOUTH OF THERE...MORNING HEATING
WILL RENEW STORM COVERAGE AND STRENGTH IN OUR SOUTHERN COUNTIES.
GREATEST GROWTH IN COVERAGE AND STRENGTH...SUGGESTED BY ALL MODELS
WILL OCCUR SOUTH AND EAST OF OUR FORECAST AREA. STILL ENOUGH
ENERGY TO BUILD THAT LOCALIZED STRONG WIND GUSTS COULD OCCUR IN
OUR SOUTHERN MOST AREAS.
WEDNESDAY NIGHT INTO FRIDAY...
NO ISSUES THIS FORECAST PERIOD. CANADIAN HIGH PRESSURE BUILDS IN
AND DROPS DEWPOINTS BACK TO LOWER 50S...MIN TEMPS BACK INTO THE
MID AND UPPER 50S...AND MAX TEMPS BACK TO THE UPPER 70S AND LOWER
80S. FRONTAL BOUNDARY THAT DROPPED TO THE OHIO RIVER BEGINS
GETTING PULLED BACK NORTH AS LOW PRESSURE TRACKS INTO THE PLAINS
BRINGING A RETURN TO SOUTHWEST FLOW FRIDAY BUT NO STORMS BEFORE
FRIDAY NIGHT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ISSUED AT 138 PM EDT TUE JUL 22 2014
THERE IS A HIGH CONFIDENCE FORECAST WITH LITTLE REASON TO CHANGE THE
REGIONAL INITIALIZATION.
UNUSUALLY LARGE STRONG WEATHER PATTERNS FOR THIS TIME OF YEAR ARE
GOING TO PERSIST INTO NEXT WEEK. SUCH WELL DEFINED SYSTEMS ARE
RELATIVELY EASY FOR THE MODELS TO FORECAST. GIVEN THEIR FORECASTS
ARE CLOSE THERE IS A GOOD CHANCE THEY WILL WORK OUT.
FORECAST CONFIDENCE IS A LITTLE LOWER FOR SUNDAY AND SUNDAY NIGHT
THAN AT OTHER TIMES. THE REASON IS A FRONT WILL BE CROSSING THE
AREA...AND EVEN MINOR DIFFERENCES IN TIMING COULD HAVE A BIG
EFFECT ON THE SENSIBLE WEATHER.
&&
.AVIATION /DISCUSSION FOR THE 23/06Z TAFS/...
ISSUED AT 1237 AM EDT WED JUL 23 2014
VFR THROUGH THE PERIOD SAVE FOR POSSIBLE MVFR CONDITIONS IN ANY
SHOWERS...WHICH ARE TOO LOW PROBABILITY FOR INCLUSION...AND FOG AT
BMG WHICH MAY MAKE IT INTO IFR TERRITORY NEAR DAYBREAK.
IT NOW APPEARS SOMEWHAT LESS LIKELY THAT THUNDERSTORMS WILL IMPACT
THE TERMINALS AS INSTABILITY IS RELATIVELY WEAKER ACROSS THE AREA.
LATEST SHORT TERM MODELS SHOW CONVECTION WEAKENING AS WELL. WILL
BACK EVERYONE DOWN TO A VCSH MENTION.
FRONT WILL MOVE THROUGH AND WINDS WILL SWING TO THE NORTHWEST/NORTH
IN ITS WAKE TOMORROW...WITH ONLY SCATTERED FAIR WEATHER CUMULUS AND
SOME HIGH CLOUDS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...DT
NEAR TERM...DT/NIELD
SHORT TERM...DT
LONG TERM...JK
AVIATION...NIELD/50
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
1140 AM MDT WED JUL 23 2014
.UPDATE...
ISSUED AT 1050 AM MDT WED JUL 23 2014
THUNDERSTORMS CONTINUE ALONG PERIPHERY OF LARGE H5 TROUGH CENTERED
SOUTHWEST OF CWA. INTENSITY HAS NOTICEABLY DIMINISHED OVER THE
PAST HOUR OR SO AND THINK TREND WILL LIKELY CONTINUE WITH OVERALL
WEAK FORCING EXPECTED TO WEAKEN FURTHER.
STRONG OUTFLOW BOUNDARY HAS CREATED FAIRLY GUSTY EASTERLY WINDS
AND A PERIOD OF LIGHT DRIZZLE AS IT MOVED THROUGH ACROSS WESTERN
CWA. THIS WILL CONTINUE TO DECREASE IN COVERAGE AND ALLOW FOR THE
WINDS TO ONCE AGAIN BECOME SOUTHEASTERLY IN RESPONSE TO LEE TROUGH.
TEMPS ARE VERY MUCH A CONCERN AS STORMS...OUTFLOW AND FOG HAVE
HELD TEMPS DOWN CONSIDERABLY. HAVE LOWERED MAXES A FEW
DEGREES...BUT WITH STRONG JULY SUN THINK THINGS WILL REBOUND
QUICKLY WITH CLEARING.
UPDATE ISSUED AT 700 AM MDT WED JUL 23 2014
STRONG THUNDERSTORMS HAVE REDEVELOPED TO THE NORTH ACROSS WEST
CENTRAL NEBRASKA ALONG AND NORTH OF AREA OF H8 TO H75 PERSISTENT
WAA. WHILE FORCING GENERALLY DECREASES INTO THE CWA AS WINDS ALOFT
DIMINISH...AM CONCERNED ABOUT CURRENT RAP DEPICTION OF NEARLY 3000
J/KG OF ELEVATED CAPE AND LITTLE CINH LOCATED AROUND H725. WHILE
FORCING MAY BE DIMINISHED...WILL NOT BE OUT OF THE QUESTION FOR
THESE STORMS TO PROPAGATE INTO THIS POTENTIALLY UNSTABLE AIRMASS.
HAVE INCREASED/REFINED POPS TO ACCOUNT FOR THIS BUT THERE STILL IS
A LOT OF QUESTION WITH REGARDS TO HOW FAR SOUTH STORMS WILL MAKE
IT. GIVEN AFOREMENTIONED INSTABILITY...SEVERE STORMS WILL BE
POSSIBLE THROUGH THE MORNING HOURS.
UPDATE ISSUED AT 552 AM MDT WED JUL 23 2014
NO MAJOR UPDATES FOR THIS ESTF ISSUANCE. CONTINUING MENTION OF
PATCHY FOG IN FORECAST AS SPOTTY FOG SHOWING UP IN LATEST OBS.
LATEST RADAR LOOP SHOWING ISOLATED/SCATTERED RW/TRW ALONG PORTIONS
OF OUR CWA...SO HAVE LEFT IN CURRENT MENTION OF PRECIPITATION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 215 AM MDT WED JUL 23 2014
SCATTERED THUNDERSTORMS ALONG NORTHERN BORDER ZONES THIS MORNING IN
CONNECTION WITH FRONTAL BOUNDARY...REMNANTS WHICH HAS BEEN
MEANDERING OVER KANSAS/NEBRASKA OVERNIGHT. MOST OF THE PRECIPITATION
WILL OCCUR OUT OF CWA...BUT HAVE INCLUDED SL CHANCE POPS FOR TRW
THRU 14Z-15Z FOR NORTHERN ZONES. HIGH DEWPTS AROUND THE AREA
CREATING MUGGY CONDITIONS WHICH COULD TRANSLATE INTO A FEW HOURS OF
PATCHY FOG THIS MORNING UNTIL SUNRISE SO HAVE MENTIONED FOR ALL
AREAS. MID/UPPER LEVEL RIDGE WILL RE-ASSERT ITSELF AGAIN ACROSS THE
CWA TODAY INTO TONIGHT. WITH THIS...EXPECTING YET ANOTHER HOT DAY
ACROSS THE AREA...WITH MID TO UPPER 90S FOR HIGHS...AND MID TO
UPPER 60S FOR OVERNIGHT LOWS. ONLY WESTERN ZONES WILL POTENTIALLY
SEE A LATE DAY REPRIEVE AS ISOLATED TRW MAY DEVELOP AS LEE-SIDE
TROUGH SETS UP ALONG EASTERN ROCKIES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 215 AM MDT WED JUL 23 2014
FOR THE THURSDAY THROUGH FRIDAY NIGHT PERIODS...THE CWA WILL
CONTINUE TO SEE MAINLY HOT AND DRY CONDITIONS AS BROAD H5/H7 RIDGE
REMAINS OVER THE AREA. DOWN TO THE SURFACE...LEE-SIDE TROUGH
DEVELOPS AND MOVES ACROSS THE REGION THURSDAY/THURSDAY NIGHT WITH A
WEAK SHORTWAVE WORKING OVER TOP OF RIDGE...AS MODELS DO SHOW SOME
FLATTENING POTENTIAL FRIDAY/FRIDAY NIGHT WHICH MAY BRING A CHANCE
FOR CONVECTION. WITH 925 MB TEMPERATURES REMAINING IN THE +35C TO
+40C...FORECASTED HIGHS WILL STAY IN THE 95-100 DEGREE RANGE FOR
BOTH DAYS. OVERNIGHT LOWS WILL STAY IN 60S...WARMEST IN EASTERN
ZONES. BOTH HIGHS/LOWS WILL BE AFFECTED AT TIMES FROM EXPECTED CLOUD
COVER/PRECIP...BUT WILL BE LOCALIZED AS WILL BE KEEPING SL CHANCE
POPS IN FOR TRW. BEST CHANCES FOR CONVECTION THURSDAY/THURSDAY NIGHT
WILL BE SPLIT DUE TO SLOW MOVEMENT OF TROUGH OFF THE ROCKIES...AND
FOR FRIDAY/FRIDAY NIGHT THE MAIN FOCUS WILL SHIFT TO NORTHERN
SECTIONS DUE TO TRACK OF SHORTWAVE.
COOLING TREND LATE THIS WEEKEND INTO NEXT WEEK WITH A FEW CHANCES
FOR PRECIP ALONG THE WAY. HAVE GENERALLY LOWERED POPS ACROSS THE
FORECAST PERIOD...BUT AM STILL CONFIDENT WE WILL SEE SOME CONVECTIVE
ACTIVITY MOST DAYS. UPPER FLOW WILL BE MAINLY OUT OF THE NORTHWEST
AS AN UPPER HIGH OVER THE FOUR CORNERS REGION RETROGRADES WEST A BIT
AND A RIDGE DEVELOPS ACROSS THE GREAT BASIN REGION EARLY NEXT WEEK.
COLD FRONT ARRIVING OVER THE WEEKEND WILL BRING RELATIVELY COOLER
TEMPS AND /THANKFULLY/ LOWER DEW POINTS.
SATURDAY...WEAK IMPULSES MOVING ACROSS THE COLORADO ROCKIES COULD
PROVIDE AMPLE LARGE SCALE LIFT FOR ISOLATED STORMS TO DEVELOP DURING
THE DAY. PREVIOUS GUIDANCE HAD INDICATED SUFFICIENT INSTABILITY FOR
STRONG TO SEVERE THUNDERSTORMS...BUT IT SEEMS THE ECMWF IS NOW
LEANING TOWARDS WHAT HAS RECENTLY BEEN A VERY DRY GFS. GEM REMAINS
STEADFAST IN SOME INSTABILITY DUE TO BETTER MOISTURE THROUGHOUT THE
COLUMN...SO WILL CONTINUE TO KEEP SOME POPS IN PLACE DESPITE THE DRY
GFS AND ECMWF. SATURDAY NIGHT IS A DIFFERENT STORY...WITH
GEFS/ECMWF/GEM INDICATING INCREASED MOISTURE AVAILABILITY AS COLD
FRONT PUSHES THROUGH FROM THE NORTH/NORTHWEST. THIS SHOULD SUPPORT
AT LEAST ISOLATED STORMS LATE IN THE DAY...POSSIBLY LASTING THROUGH
THE NIGHT. UPPER LEVEL SUPPORT FOR LARGE SCALE LIFT ACROSS THE
LATEST GUIDANCE IS NOT AS SUPPORTIVE ON LATEST GUIDANCE AS PREVIOUS
RUNS HAVE BEEN...SO A BIT LOWER CONFIDENCE THAN USUAL FOR OVERNIGHT
STORMS.
SUNDAY...COOLER FOLLOWING FROPA. SOME CLOUDS DURING THE MORNING
CLEARING OUT TO A MOSTLY SUNNY DAY. SOME AFTERNOON CONVECTION
POSSIBLE BEHIND THE FRONT...THOUGH THERE IS CHANCE THE MODERATELY
STRONG CAP COULD PREVENT DEVELOPMENT. GUIDANCE IN GOOD AGREEMENT ON
AN INVERTED-V SOUNDING...SO WITH ANY STORMS THAT DEVELOP GUSTY WINDS
COULD BE POSSIBLE. A FEW STORMS COULD LAST INTO THE EVENING...ENDING
BEFORE MIDNIGHT. HIGHS LIMITED TO THE MID/UPPER 80S. OVERNIGHT LOWS
DIPPING BELOW 60 IN SOME SPOTS FOR THE FIRST TIME IN A WEEK.
MONDAY AND TUESDAY...SLIGHT CHANCE FOR SHOWERS/STORMS BOTH
DAYS...WITH THE BETTER CHANCE FOR PRECIP ON TUESDAY. A NUMBER OF
WEAK MID-LEVEL IMPULSES WILL MOVE ACROSS THE CENTRAL ROCKIES AND
INTO THE CENTRAL HIGH PLAINS IN THE NORTH-NORTHWESTERLY FLOW. IN
THIS FAVORABLE ENVIRONMENT EXPECT MOSTLY TERRAIN-BASED STORMS TO
FIRE IN THE DAY AND MOVE EAST INTO THE AREA DURING THE LATE
AFTERNOON. LOW LEVEL FLOW WILL BE OUT OF THE SOUTH WHICH WILL
INCREASE LOW LEVEL MOISTURE...AND THUS PROVIDE SOME INSTABILITY FOR
STORMS TO WORK WITH. 0-6KM BULK SHEAR IN THE 30-40KT RANGE COULD
HELP SUSTAIN STORMS THROUGH THE LATE NIGHT HOURS. HIGHS IN THE
MID/UPPER 80S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1137 AM MDT WED JUL 23 2014
MVFR CONDITIONS AT KGLD SHOUKLD END BEFORE 20Z AS AREA OF LOW
CLOUDS BEHIND THIS MORNINGS OUTFLOW BOUNDARY ARE ALREADY BEGINNING
TO BREAK UP AND EXPECT THIS TO CONTINUE. WITH COOLER...MORE STABLE
AIR IN PLACE DO NOT THINK THERE WILL BE MUCH OF A THUNDERSTORM
THREAT AT EITHER SITE AND EXPECT VFR FLIGHT CATEGORIES TO PREVAIL.
SMALL THREAT FOR RADIATIONAL FOG AT MCK TOMORROW MORNING...BUT
FAR TOO LOW TO INCLUDE IN TAF ATTM.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...JN
LONG TERM...JJM
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1055 AM MDT WED JUL 23 2014
.UPDATE...
ISSUED AT 1050 AM MDT WED JUL 23 2014
THUNDERSTORMS CONTINUE ALONG PERIPHERY OF LARGE H5 TROUGH CENTERED
SOUTHWEST OF CWA. INTENSITY HAS NOTICEABLY DIMINISHED OVER THE
PAST HOUR OR SO AND THINK TREND WILL LIKELY CONTINUE WITH OVERALL
WEAK FORCING EXPECTED TO WEAKEN FURTHER.
STRONG OUTFLOW BOUNDARY HAS CREATED FAIRLY GUSTY EASTERLY WINDS
AND A PERIOD OF LIGHT DRIZZLE AS IT MOVED THROUGH ACROSS WESTERN
CWA. THIS WILL CONTINUE TO DECREASE IN COVERAGE AND ALLOW FOR THE
WINDS TO ONCE AGAIN BECOME SOUTHEASTERLY IN RESPONSE TO LEE TROUGH.
TEMPS ARE VERY MUCH A CONCERN AS STORMS...OUTFLOW AND FOG HAVE
HELD TEMPS DOWN CONSIDERABLY. HAVE LOWERED MAXES A FEW
DEGREES...BUT WITH STRONG JULY SUN THINK THINGS WILL REBOUND
QUICKLY WITH CLEARING.
UPDATE ISSUED AT 700 AM MDT WED JUL 23 2014
STRONG THUNDERSTORMS HAVE REDEVELOPED TO THE NORTH ACROSS WEST
CENTRAL NEBRASKA ALONG AND NORTH OF AREA OF H8 TO H75 PERSISTENT
WAA. WHILE FORCING GENERALLY DECREASES INTO THE CWA AS WINDS ALOFT
DIMINISH...AM CONCERNED ABOUT CURRENT RAP DEPICTION OF NEARLY 3000
J/KG OF ELEVATED CAPE AND LITTLE CINH LOCATED AROUND H725. WHILE
FORCING MAY BE DIMINISHED...WILL NOT BE OUT OF THE QUESTION FOR
THESE STORMS TO PROPAGATE INTO THIS POTENTIALLY UNSTABLE AIRMASS.
HAVE INCREASED/REFINED POPS TO ACCOUNT FOR THIS BUT THERE STILL IS
A LOT OF QUESTION WITH REGARDS TO HOW FAR SOUTH STORMS WILL MAKE
IT. GIVEN AFOREMENTIONED INSTABILITY...SEVERE STORMS WILL BE
POSSIBLE THROUGH THE MORNING HOURS.
UPDATE ISSUED AT 552 AM MDT WED JUL 23 2014
NO MAJOR UPDATES FOR THIS ESTF ISSUANCE. CONTINUING MENTION OF
PATCHY FOG IN FORECAST AS SPOTTY FOG SHOWING UP IN LATEST OBS.
LATEST RADAR LOOP SHOWING ISOLATED/SCATTERED RW/TRW ALONG PORTIONS
OF OUR CWA...SO HAVE LEFT IN CURRENT MENTION OF PRECIPITATION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 215 AM MDT WED JUL 23 2014
SCATTERED THUNDERSTORMS ALONG NORTHERN BORDER ZONES THIS MORNING IN
CONNECTION WITH FRONTAL BOUNDARY...REMNANTS WHICH HAS BEEN
MEANDERING OVER KANSAS/NEBRASKA OVERNIGHT. MOST OF THE PRECIPITATION
WILL OCCUR OUT OF CWA...BUT HAVE INCLUDED SL CHANCE POPS FOR TRW
THRU 14Z-15Z FOR NORTHERN ZONES. HIGH DEWPTS AROUND THE AREA
CREATING MUGGY CONDITIONS WHICH COULD TRANSLATE INTO A FEW HOURS OF
PATCHY FOG THIS MORNING UNTIL SUNRISE SO HAVE MENTIONED FOR ALL
AREAS. MID/UPPER LEVEL RIDGE WILL RE-ASSERT ITSELF AGAIN ACROSS THE
CWA TODAY INTO TONIGHT. WITH THIS...EXPECTING YET ANOTHER HOT DAY
ACROSS THE AREA...WITH MID TO UPPER 90S FOR HIGHS...AND MID TO
UPPER 60S FOR OVERNIGHT LOWS. ONLY WESTERN ZONES WILL POTENTIALLY
SEE A LATE DAY REPRIEVE AS ISOLATED TRW MAY DEVELOP AS LEE-SIDE
TROUGH SETS UP ALONG EASTERN ROCKIES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 215 AM MDT WED JUL 23 2014
FOR THE THURSDAY THROUGH FRIDAY NIGHT PERIODS...THE CWA WILL
CONTINUE TO SEE MAINLY HOT AND DRY CONDITIONS AS BROAD H5/H7 RIDGE
REMAINS OVER THE AREA. DOWN TO THE SURFACE...LEE-SIDE TROUGH
DEVELOPS AND MOVES ACROSS THE REGION THURSDAY/THURSDAY NIGHT WITH A
WEAK SHORTWAVE WORKING OVER TOP OF RIDGE...AS MODELS DO SHOW SOME
FLATTENING POTENTIAL FRIDAY/FRIDAY NIGHT WHICH MAY BRING A CHANCE
FOR CONVECTION. WITH 925 MB TEMPERATURES REMAINING IN THE +35C TO
+40C...FORECASTED HIGHS WILL STAY IN THE 95-100 DEGREE RANGE FOR
BOTH DAYS. OVERNIGHT LOWS WILL STAY IN 60S...WARMEST IN EASTERN
ZONES. BOTH HIGHS/LOWS WILL BE AFFECTED AT TIMES FROM EXPECTED CLOUD
COVER/PRECIP...BUT WILL BE LOCALIZED AS WILL BE KEEPING SL CHANCE
POPS IN FOR TRW. BEST CHANCES FOR CONVECTION THURSDAY/THURSDAY NIGHT
WILL BE SPLIT DUE TO SLOW MOVEMENT OF TROUGH OFF THE ROCKIES...AND
FOR FRIDAY/FRIDAY NIGHT THE MAIN FOCUS WILL SHIFT TO NORTHERN
SECTIONS DUE TO TRACK OF SHORTWAVE.
COOLING TREND LATE THIS WEEKEND INTO NEXT WEEK WITH A FEW CHANCES
FOR PRECIP ALONG THE WAY. HAVE GENERALLY LOWERED POPS ACROSS THE
FORECAST PERIOD...BUT AM STILL CONFIDENT WE WILL SEE SOME CONVECTIVE
ACTIVITY MOST DAYS. UPPER FLOW WILL BE MAINLY OUT OF THE NORTHWEST
AS AN UPPER HIGH OVER THE FOUR CORNERS REGION RETROGRADES WEST A BIT
AND A RIDGE DEVELOPS ACROSS THE GREAT BASIN REGION EARLY NEXT WEEK.
COLD FRONT ARRIVING OVER THE WEEKEND WILL BRING RELATIVELY COOLER
TEMPS AND /THANKFULLY/ LOWER DEW POINTS.
SATURDAY...WEAK IMPULSES MOVING ACROSS THE COLORADO ROCKIES COULD
PROVIDE AMPLE LARGE SCALE LIFT FOR ISOLATED STORMS TO DEVELOP DURING
THE DAY. PREVIOUS GUIDANCE HAD INDICATED SUFFICIENT INSTABILITY FOR
STRONG TO SEVERE THUNDERSTORMS...BUT IT SEEMS THE ECMWF IS NOW
LEANING TOWARDS WHAT HAS RECENTLY BEEN A VERY DRY GFS. GEM REMAINS
STEADFAST IN SOME INSTABILITY DUE TO BETTER MOISTURE THROUGHOUT THE
COLUMN...SO WILL CONTINUE TO KEEP SOME POPS IN PLACE DESPITE THE DRY
GFS AND ECMWF. SATURDAY NIGHT IS A DIFFERENT STORY...WITH
GEFS/ECMWF/GEM INDICATING INCREASED MOISTURE AVAILABILITY AS COLD
FRONT PUSHES THROUGH FROM THE NORTH/NORTHWEST. THIS SHOULD SUPPORT
AT LEAST ISOLATED STORMS LATE IN THE DAY...POSSIBLY LASTING THROUGH
THE NIGHT. UPPER LEVEL SUPPORT FOR LARGE SCALE LIFT ACROSS THE
LATEST GUIDANCE IS NOT AS SUPPORTIVE ON LATEST GUIDANCE AS PREVIOUS
RUNS HAVE BEEN...SO A BIT LOWER CONFIDENCE THAN USUAL FOR OVERNIGHT
STORMS.
SUNDAY...COOLER FOLLOWING FROPA. SOME CLOUDS DURING THE MORNING
CLEARING OUT TO A MOSTLY SUNNY DAY. SOME AFTERNOON CONVECTION
POSSIBLE BEHIND THE FRONT...THOUGH THERE IS CHANCE THE MODERATELY
STRONG CAP COULD PREVENT DEVELOPMENT. GUIDANCE IN GOOD AGREEMENT ON
AN INVERTED-V SOUNDING...SO WITH ANY STORMS THAT DEVELOP GUSTY WINDS
COULD BE POSSIBLE. A FEW STORMS COULD LAST INTO THE EVENING...ENDING
BEFORE MIDNIGHT. HIGHS LIMITED TO THE MID/UPPER 80S. OVERNIGHT LOWS
DIPPING BELOW 60 IN SOME SPOTS FOR THE FIRST TIME IN A WEEK.
MONDAY AND TUESDAY...SLIGHT CHANCE FOR SHOWERS/STORMS BOTH
DAYS...WITH THE BETTER CHANCE FOR PRECIP ON TUESDAY. A NUMBER OF
WEAK MID-LEVEL IMPULSES WILL MOVE ACROSS THE CENTRAL ROCKIES AND
INTO THE CENTRAL HIGH PLAINS IN THE NORTH-NORTHWESTERLY FLOW. IN
THIS FAVORABLE ENVIRONMENT EXPECT MOSTLY TERRAIN-BASED STORMS TO
FIRE IN THE DAY AND MOVE EAST INTO THE AREA DURING THE LATE
AFTERNOON. LOW LEVEL FLOW WILL BE OUT OF THE SOUTH WHICH WILL
INCREASE LOW LEVEL MOISTURE...AND THUS PROVIDE SOME INSTABILITY FOR
STORMS TO WORK WITH. 0-6KM BULK SHEAR IN THE 30-40KT RANGE COULD
HELP SUSTAIN STORMS THROUGH THE LATE NIGHT HOURS. HIGHS IN THE
MID/UPPER 80S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 523 AM MDT WED JUL 23 2014
FOR GLD/MCK THROUGH 14Z...MIX OF CONDITIONS FROM MVFR DOWN TO LIFR
WITH FOG 4-6SM AND CEILINGS RANGING FROM BKN004-010. AFT 14Z VFR
CONDITIONS WITH FEW020-030 SCT200-300. VCTS POSSIBLE FOR GLD 01Z-
06Z WITH SCT060CB. WINDS RANGE FROM ENE TO ESE 5-10KTS BECM SSE
10-20KTS BY 14Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...JN
LONG TERM...JJM
AVIATION...JN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
706 AM MDT WED JUL 23 2014
.UPDATE...
ISSUED AT 700 AM MDT WED JUL 23 2014
STRONG THUNDERSTORMS HAVE REDEVELOPED TO THE NORTH ACROSS WEST
CENTRAL NEBRASKA ALONG AND NORTH OF AREA OF H8 TO H75 PERSISTENT
WAA. WHILE FORCING GENERALLY DECREASES INTO THE CWA AS WINDS ALOFT
DIMINISH...AM CONCERNED ABOUT CURRENT RAP DEPICTION OF NEARLY 3000
J/KG OF ELEVATED CAPE AND LITTLE CINH LOCATED AROUND H725. WHILE
FORCING MAY BE DIMINISHED...WILL NOT BE OUT OF THE QUESTION FOR
THESE STORMS TO PROPAGATE INTO THIS POTENTIALLY UNSTABLE AIRMASS.
HAVE INCREASED/REFINED POPS TO ACCOUNT FOR THIS BUT THERE STILL IS
A LOT OF QUESTION WITH REGARDS TO HOW FAR SOUTH STORMS WILL MAKE
IT. GIVEN AFOREMENTIONED INSTABILITY...SEVERE STORMS WILL BE
POSSIBLE THROUGH THE MORNING HOURS.
UPDATE ISSUED AT 552 AM MDT WED JUL 23 2014
NO MAJOR UPDATES FOR THIS ESTF ISSUANCE. CONTINUING MENTION OF
PATCHY FOG IN FORECAST AS SPOTTY FOG SHOWING UP IN LATEST OBS.
LATEST RADAR LOOP SHOWING ISOLATED/SCATTERED RW/TRW ALONG PORTIONS
OF OUR CWA...SO HAVE LEFT IN CURRENT MENTION OF PRECIPITATION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 215 AM MDT WED JUL 23 2014
SCATTERED THUNDERSTORMS ALONG NORTHERN BORDER ZONES THIS MORNING IN
CONNECTION WITH FRONTAL BOUNDARY...REMNANTS WHICH HAS BEEN
MEANDERING OVER KANSAS/NEBRASKA OVERNIGHT. MOST OF THE PRECIPITATION
WILL OCCUR OUT OF CWA...BUT HAVE INCLUDED SL CHANCE POPS FOR TRW
THRU 14Z-15Z FOR NORTHERN ZONES. HIGH DEWPTS AROUND THE AREA
CREATING MUGGY CONDITIONS WHICH COULD TRANSLATE INTO A FEW HOURS OF
PATCHY FOG THIS MORNING UNTIL SUNRISE SO HAVE MENTIONED FOR ALL
AREAS. MID/UPPER LEVEL RIDGE WILL RE-ASSERT ITSELF AGAIN ACROSS THE
CWA TODAY INTO TONIGHT. WITH THIS...EXPECTING YET ANOTHER HOT DAY
ACROSS THE AREA...WITH MID TO UPPER 90S FOR HIGHS...AND MID TO
UPPER 60S FOR OVERNIGHT LOWS. ONLY WESTERN ZONES WILL POTENTIALLY
SEE A LATE DAY REPRIEVE AS ISOLATED TRW MAY DEVELOP AS LEE-SIDE
TROUGH SETS UP ALONG EASTERN ROCKIES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 215 AM MDT WED JUL 23 2014
FOR THE THURSDAY THROUGH FRIDAY NIGHT PERIODS...THE CWA WILL
CONTINUE TO SEE MAINLY HOT AND DRY CONDITIONS AS BROAD H5/H7 RIDGE
REMAINS OVER THE AREA. DOWN TO THE SURFACE...LEE-SIDE TROUGH
DEVELOPS AND MOVES ACROSS THE REGION THURSDAY/THURSDAY NIGHT WITH A
WEAK SHORTWAVE WORKING OVER TOP OF RIDGE...AS MODELS DO SHOW SOME
FLATTENING POTENTIAL FRIDAY/FRIDAY NIGHT WHICH MAY BRING A CHANCE
FOR CONVECTION. WITH 925 MB TEMPERATURES REMAINING IN THE +35C TO
+40C...FORECASTED HIGHS WILL STAY IN THE 95-100 DEGREE RANGE FOR
BOTH DAYS. OVERNIGHT LOWS WILL STAY IN 60S...WARMEST IN EASTERN
ZONES. BOTH HIGHS/LOWS WILL BE AFFECTED AT TIMES FROM EXPECTED CLOUD
COVER/PRECIP...BUT WILL BE LOCALIZED AS WILL BE KEEPING SL CHANCE
POPS IN FOR TRW. BEST CHANCES FOR CONVECTION THURSDAY/THURSDAY NIGHT
WILL BE SPLIT DUE TO SLOW MOVEMENT OF TROUGH OFF THE ROCKIES...AND
FOR FRIDAY/FRIDAY NIGHT THE MAIN FOCUS WILL SHIFT TO NORTHERN
SECTIONS DUE TO TRACK OF SHORTWAVE.
COOLING TREND LATE THIS WEEKEND INTO NEXT WEEK WITH A FEW CHANCES
FOR PRECIP ALONG THE WAY. HAVE GENERALLY LOWERED POPS ACROSS THE
FORECAST PERIOD...BUT AM STILL CONFIDENT WE WILL SEE SOME CONVECTIVE
ACTIVITY MOST DAYS. UPPER FLOW WILL BE MAINLY OUT OF THE NORTHWEST
AS AN UPPER HIGH OVER THE FOUR CORNERS REGION RETROGRADES WEST A BIT
AND A RIDGE DEVELOPS ACROSS THE GREAT BASIN REGION EARLY NEXT WEEK.
COLD FRONT ARRIVING OVER THE WEEKEND WILL BRING RELATIVELY COOLER
TEMPS AND /THANKFULLY/ LOWER DEW POINTS.
SATURDAY...WEAK IMPULSES MOVING ACROSS THE COLORADO ROCKIES COULD
PROVIDE AMPLE LARGE SCALE LIFT FOR ISOLATED STORMS TO DEVELOP DURING
THE DAY. PREVIOUS GUIDANCE HAD INDICATED SUFFICIENT INSTABILITY FOR
STRONG TO SEVERE THUNDERSTORMS...BUT IT SEEMS THE ECMWF IS NOW
LEANING TOWARDS WHAT HAS RECENTLY BEEN A VERY DRY GFS. GEM REMAINS
STEADFAST IN SOME INSTABILITY DUE TO BETTER MOISTURE THROUGHOUT THE
COLUMN...SO WILL CONTINUE TO KEEP SOME POPS IN PLACE DESPITE THE DRY
GFS AND ECMWF. SATURDAY NIGHT IS A DIFFERENT STORY...WITH
GEFS/ECMWF/GEM INDICATING INCREASED MOISTURE AVAILABILITY AS COLD
FRONT PUSHES THROUGH FROM THE NORTH/NORTHWEST. THIS SHOULD SUPPORT
AT LEAST ISOLATED STORMS LATE IN THE DAY...POSSIBLY LASTING THROUGH
THE NIGHT. UPPER LEVEL SUPPORT FOR LARGE SCALE LIFT ACROSS THE
LATEST GUIDANCE IS NOT AS SUPPORTIVE ON LATEST GUIDANCE AS PREVIOUS
RUNS HAVE BEEN...SO A BIT LOWER CONFIDENCE THAN USUAL FOR OVERNIGHT
STORMS.
SUNDAY...COOLER FOLLOWING FROPA. SOME CLOUDS DURING THE MORNING
CLEARING OUT TO A MOSTLY SUNNY DAY. SOME AFTERNOON CONVECTION
POSSIBLE BEHIND THE FRONT...THOUGH THERE IS CHANCE THE MODERATELY
STRONG CAP COULD PREVENT DEVELOPMENT. GUIDANCE IN GOOD AGREEMENT ON
AN INVERTED-V SOUNDING...SO WITH ANY STORMS THAT DEVELOP GUSTY WINDS
COULD BE POSSIBLE. A FEW STORMS COULD LAST INTO THE EVENING...ENDING
BEFORE MIDNIGHT. HIGHS LIMITED TO THE MID/UPPER 80S. OVERNIGHT LOWS
DIPPING BELOW 60 IN SOME SPOTS FOR THE FIRST TIME IN A WEEK.
MONDAY AND TUESDAY...SLIGHT CHANCE FOR SHOWERS/STORMS BOTH
DAYS...WITH THE BETTER CHANCE FOR PRECIP ON TUESDAY. A NUMBER OF
WEAK MID-LEVEL IMPULSES WILL MOVE ACROSS THE CENTRAL ROCKIES AND
INTO THE CENTRAL HIGH PLAINS IN THE NORTH-NORTHWESTERLY FLOW. IN
THIS FAVORABLE ENVIRONMENT EXPECT MOSTLY TERRAIN-BASED STORMS TO
FIRE IN THE DAY AND MOVE EAST INTO THE AREA DURING THE LATE
AFTERNOON. LOW LEVEL FLOW WILL BE OUT OF THE SOUTH WHICH WILL
INCREASE LOW LEVEL MOISTURE...AND THUS PROVIDE SOME INSTABILITY FOR
STORMS TO WORK WITH. 0-6KM BULK SHEAR IN THE 30-40KT RANGE COULD
HELP SUSTAIN STORMS THROUGH THE LATE NIGHT HOURS. HIGHS IN THE
MID/UPPER 80S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 523 AM MDT WED JUL 23 2014
FOR GLD/MCK THROUGH 14Z...MIX OF CONDITIONS FROM MVFR DOWN TO LIFR
WITH FOG 4-6SM AND CEILINGS RANGING FROM BKN004-010. AFT 14Z VFR
CONDITIONS WITH FEW020-030 SCT200-300. VCTS POSSIBLE FOR GLD 01Z-
06Z WITH SCT060CB. WINDS RANGE FROM ENE TO ESE 5-10KTS BECM SSE
10-20KTS BY 14Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...JN
LONG TERM...JJM
AVIATION...JN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1200 AM MDT WED JUL 23 2014
.UPDATE...
ISSUED AT 552 PM MDT TUE JUL 22 2014
UPDATED TO REMOVE THE HEAT ADVISORY SINCE TEMPERATURES ARE ON THE
DECLINE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 1255 PM MDT TUE JUL 22 2014
18Z WATER VAPOR IMAGERY INDICATED LARGE UPPER LEVEL RIDGE CENTERED
OVER NEW MEXICO WITH RUC ANALYSIS INDICATING A 600 DM RIDGE IN
PLACE AT H5. AT THE SFC...OUTFLOW BOUNDARY HAS STALLED ACROSS THE
EXTREME SOUTHERN CWA...BETWEEN TRIBUNE AND LEOTI EXTENDING
NORTHEAST TOWARDS HILL CITY.
MAIN CONCERNS FOR THE SHORT TERM WILL BE TEMPS AND PRECIP CHANCES
THIS EVENING AND TOMORROW AFTERNOON.
LACK OF ANY MEANINGFUL CU FIELD AT 19Z LOWERS OVERALL CONFIDENCE
IN LATE AFTERNOON THUNDERSTORM FORECAST AND WHILE AN ISOLATED
STORM IS STILL POSSIBLE...HAVE DOUBTS THAT ANYTHING WILL FIRE
ALONG REMAINING OUTFLOW BOUNDARY. WITH H85-H7 WAA INCREASING
TONIGHT...IT WILL BE POSSIBLE FOR STORMS COMING OUT OF THE
NORTHWEST TO MAINTAIN THEMSELVES BUT WITH WEAK WINDS THROUGHOUT
THE COLUMN STORM MOTION WOULD BE SLOW. A FEW MODELS SUGGEST
ELEVATED CONVECTION DEVELOPING AFTER 06Z AND WHILE THE FORCING
WILL BE THERE...CONDENSATION PRESSURE DEFICITS AND PRESSURE
ADVECTION VALUES ON 310 AND 315K SURFACES WOULD SUGGEST SATURATION
UNLIKELY. IF STORMS/CLOUDS CANNOT DEVELOP...BACKED EASTERLY FLOW
WITH A 100MB POCKET OF LOW LEVEL MOISTURE WOULD SUPPORT AT LEAST
PATCHY FOG PRIOR TO 15Z. GENERAL CONSENSUS OF MODELS SUGGESTS
TEMPERATURES AROUND 5 DEGREES COOLER ON WEDNESDAY THAN
TODAY...GIVEN EXPECTED SFC PATTERN THAT APPEARS REASONABLE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 231 PM MDT TUE JUL 22 2014
A RIDGE OVER THE ROCKIES/PLAINS WILL SHIFT TO THE DESERT SOUTHWEST
BY FRIDAY. A SURFACE TROUGH WILL BE IN EASTERN COLORADO FROM
WEDNESDAY NIGHT UNTIL IT SHIFTS INTO SOUTHWEST KANSAS FRIDAY.
THE SURFACE TROUGH WILL FOCUS THUNDERSTORM DEVELOPMENT WEDNESDAY
EVENING. A SHORTWAVE MOVES INTO THE AREA WILL PROVIDE FORCING. CAPE
WILL RANGE FROM 1000 TO 2000J/KG AND SHEAR WILL BE 20KTS. FORECAST
SOUNDINGS INDICATE AN OVERALL LACK OF MID LEVEL MOISTURE SO WILL
CONTINUE SLIGHT CHANCE POPS.
FOR THURSDAY AFTERNOON AND EVENING, THE SURFACE TROUGH WILL BE
ORIENTED ACROSS NORTHWEST KANSAS BUT ONCE AGAIN FORECAST SOUNDINGS
SHOW HIGH BASED MOISTURE AROUND 600MB. CAPE RANGES FROM 200J/KG IN
EASTERN COLORADO TO 800J/KG IN THE EAST. DUE TO THESE MARGINAL
PARAMETERS WILL STAY WITH SLIGHT CHANCE POPS WITH COVERAGE OVER THE
ENTIRE FA AS THE TROUGH SHIFTS SOUTH DURING THE EVENING.
SURFACE CONVERGENCE AND HEATING WILL BE THE MAIN FORCING FRIDAY
AFTERNOON WITH THE TROUGH WELL TO THE SOUTH OF THE FA. STORMS SHOULD
INITIATE ON THE HIGHER TERRAIN IN EASTERN COLORADO WHERE LIFT WILL BE
MAXIMIZED. SLIGHT CHANCE POPS WILL CONTINUE FOR FRIDAY AFTERNOON.
MAX TEMPERATURES WILL REACH THE UPPER 90S THURSDAY AND FRIDAY. MIN
TEMPERATURES WILL COOL TO THE UPPER 60S WITH AROUND 70 IN THE EAST.
IN THE EXTENDED...(FRIDAY NIGHT THROUGH TUESDAY)...
THE RIDGE OVER THE SOUTHERN ROCKIES WITH SHIFT TO THE DESERT
SOUTHWEST BY SATURDAY AND CONTINUE THROUGH TUESDAY. THERE IS A
SLIGHT CHANCE OF THUNDERSTORMS FRIDAY/SATURDAY WITH STORMS
DEVELOPING DUE TO UPSLOPE WIND/SURFACE CONVERGENCE OVER THE HIGHER
TERRAIN IN EASTERN COLORADO. THESE STORMS WILL MOVE SLOWLY EAST
INTO NORTHWEST KANSAS. NUMEROUS WEAK DISTURBANCES IN NORTHWEST FLOW
WILL PROVIDE FORCING FOR AT LEAST A SLIGHT CHANCE/CHANCE OF
THUNDERSTORMS EACH DAY FROM SUNDAY THROUGH TUESDAY.
MIN TEMPERATURES WILL RANGE FROM 65 TO 70 FRIDAY AND SATURDAY NIGHTS
COOLING TO THE MID 60S SUNDAY AND MONDAY NIGHTS. MAX TEMPERATURES
WILL REACH THE MID 90S SATURDAY COOLING TO THE UPPER 80S FROM SUNDAY
THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1157 PM MDT TUE JUL 22 2014
VFR CONDITIONS ARE EXPECTED AT MCK AND GLD THROUGH THE TAF PERIOD.
MCK MAY SEE SOME SHOWERS IN THE VICINITY BETWEEN 09Z-11Z AS THE
REMNANTS OF A THUNDERSTORM IN THE NEBRASKA PANHANDLE CONTINUES
SOUTHEASTWARD INTO NORTH CENTRAL KANSAS. ADDITIONALLY...THERE MAY
BE PATCHY FOG BETWEEN 11Z-13Z AT MCK. MCK AND GLD WITH OTHERWISE
SEE MOSTLY CLEAR SKIES WITH GENERALLY SOUTHEAST WINDS BECOMING
GUSTY DURING THE AFTERNOON HOURS ON WEDNESDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...LOCKHART
SHORT TERM...JRM
LONG TERM...FS
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1210 AM CDT Wed Jul 23 2014
...Updated synopsis and aviation discussion...
.SYNOPSIS...
ISSUED AT 1205 AM CDT WED JUL 23 2014
At 00z Wednesday a 500mb high was centered over central Colorado
with an upper ridge axis extending north across the northern
Rockies. A 500mb low was located off the southwest coast of
British Columbia. A 300mb jet streak was located between the upper
high and upper low and extended from central California into Idaho.
A 700mb high was located over the Central High Plains and
temperatures varied from +12c at Omaha to +14c at Dodge City to
+17c at Denver. A 850mb cold front extended from northeast Wyoming
to southeast Nebraska at 00z Wednesday and the surface cold front
extended from northwest Kansas into northern Missouri.
&&
.UPDATE...
ISSUED AT 747 PM CDT TUE JUL 22 2014
Executing a bunch of superficial/minor tweaks... 1) will allow the heat
advisory to expire at 8 PM CDT. 2) feeble showers have tried to develop
across Rush county this evening, but are not developing vertically any
more. Looks very weak visually and have removed pops for this evening.
The HRRR suggests more convection, but this model is initializing poorly.
3) updated the HWO and EHWO. 4) running the usual ESTF grids to get
hourly t`s and sky grids in line with reality.
&&
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 1234 PM CDT TUE JUL 22 2014
The upper level high pressure system over Colorado and New Mexico
will not be going anywhere over the next two days. A cold front was
draped south across northern Kansas late this morning, with a
surface low pressure system over eastern Colorado. The cold front
will sag slowly south today, and be just north of the I-70
interstate by 7 pm CDT. This front should serve as a convergence
zone, as well as will the trough near the Colorado border. We have
small 20 percent Pops in our west and northerly zones after 23z
today/tonight, extending in the north through about midnight. The
chances are small, but if any storm does break through the cap, they
will likely be high based and with mainly down burst, strong winds
as hazards. The surface is heating up nicely and highs today should
reach the forecasted maxes of 100 to 102F. I plan to keep the Heat
Advisory ongoing through 8 pm, as currently forecast, and will
update it shortly. The convective temp from the DDC 12Z RAOB
showed 98F. I Will brief the next shift on the high based storm
low chances and the main threat being down burst winds.
There will be a few clouds tonight, resulting in partly cloudy
skies. Minimum temperatures should be from near 70F in the west
along the Colorado border, to the mid 70s in the Coldwater and
Medicine lodge areas. Again, the small chances for thunderstorms
will continue through midnight in our northern counties.
The cold front will push south to near our southern border with
Oklahoma Wednesday. This should allow slightly cooler air and some
high level clouds to cover our CWA. Max temperatures will lower
from the past two days, into the mid 90s north of I-70 to the
upper 90s in our south along the Oklahoma border. Winds on
Wednesday should be from the east at 5 to 20 mph.
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 342 PM CDT TUE JUL 22 2014
Upper level ridging will build back into the high plains region for
Thursday and into the weekend. With renewed surface troughing over
western Kansas, high temperatures ought to warm back to the high
90s, with possibly some readings over 100F. Little in the way of
thunderstorm activity is expected, although isolated thunderstorms
can`t be ruled out, particularly in far western Kansas with
elevated heating. The next cold front is expected to pass through
western Kansas by Saturday night as an upper level system over the
northwestern United States passes over the upper level ridge into
the Great Lakes. High temperatures ought to drop at least several
degrees by Sunday to the lower and mid 90s, and probably to around
90F by Monday and Tuesday. There will be small chances for
thunderstorms as the front passes and even behind the front into
Monday. A large upper level trough will persist over the upper
Midwest and Great Lakes regions through the remainder of next
week, resulting in a continued break from the hot temperatures.
There will be small chances for thunderstorms given the lack of
mid level capping; but it appears as though the upper level
pattern may be too amplified for sufficient lee troughing and
destabilization in the presence of the northwesterly mid to upper
level flow.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1205 AM CDT WED JUL 23 2014
VFR conditions are expected given that the 00Z NAM BUFR soundings
indicating limited mid to high level moisture will be present across
western Kansas as an upper high slowly moves east across Colorado
through late Wednesday. A weak cold front will move across western
Kansas early Wednesday morning. Winds at less than 10knots will
shift from the south to the northeast as this front passes. Light
northeast winds will then gradually veer to the southeast by late
day as a surface pressures begin to fall along the lee of the
Rockies and the surface ridge axis moves east towards Iowa and
Missouri.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 100 74 100 / 10 10 10 10
GCK 69 101 73 101 / 10 10 10 10
EHA 70 100 72 101 / 10 10 10 10
LBL 69 101 73 101 / 10 10 10 10
HYS 69 99 74 100 / 10 10 10 10
P28 71 99 74 100 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Sugden
SYNOPSIS...Burgert
SHORT TERM...Burke
LONG TERM...Finch
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS JACKSON KY
139 AM EDT WED JUL 23 2014
.UPDATE...
ISSUED AT 139 AM EDT WED JUL 23 2014
CONDITIONS ACROSS THE AREA REFLECT THE CURRENT FORECAST QUITE WELL.
PERHAPS SOME LESSENING OF THE CLOUD COVER IS IN ORDER AS THE MORE
WIDE SPREAD COVER IS STILL UP STREAM. OTHERWISE...THE CURRENT
FORECAST REMAINS ON TRACK AND HAVE UPLOADED THE CURRENT OBS INTO THE
GRIDS.
UPDATE ISSUED AT 1040 PM EDT TUE JUL 22 2014
THE SHOWERS HAVE DRIED UP ACROSS THE ENTIRE AREA BESIDES A SMALL CELL
OVER NORTHERN PULASKI COUNTY. THIS WILL DIMINISH THROUGH 11
PM...LEAVING MOSTLY CLEAR TO PARTLY CLOUDY SKIES OVERHEAD FOR THE
MAJORITY OF THE OVERNIGHT. EXPECT MOISTURE TO INCREASE BETWEEN 4 AND
8 AM...WITH PERHAPS A SMALL UPTICK IN CONVECTIVE ACTIVITY THREATENING
ALONG THE SOUTHEAST TERRAIN. THE LATEST HRRR IS SUGGESTING SOME
ACTIVITY MAKING IT IN FROM THE NORTHWEST BEFORE DAWN...HOWEVER THE
CONVECTIVE OUTCOME LOOKS A BIT QUICK ACCORDING TO THE LATEST
SATELLITE TRENDS...SO STUCK WITH THE INHERITED DRY POPS IN THE
BLUEGRASS FOR NOW. BALMY LOWS OF AROUND THE 70 DEGREE MARK FOR MOST
LOCATIONS STILL LOOK ON TARGET. DID INCORPORATE THE LATEST HOURLY
OBSERVATIONS INTO THE DIURNAL DROP OFF FOR THE REST OF THE NIGHT.
UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 817 PM EDT TUE JUL 22 2014
CONVECTION IS ON THE DECLINE WITH THE LOSS OF HEATING. WILL HANG ONTO
ISOLATED SHOWERS AND A RUMBLE OF THUNDER FOR ANOTHER HOUR OR TWO...
BEFORE A LULL IS THEN EXPECTED INTO THE OVERNIGHT. AS WEAKER
SOUTHWEST FLOW ENGAGES IN TH LOW LEVELS TOWARDS DAWN...THERE MAY BE A
SMALL INCREASE IN CONVECTION ONCE AGAIN...WHICH THE CURRENT FORECAST
ALREADY HAS WELL IN HAND. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 420 PM EDT TUE JUL 22 2014
AS OF LATE AFTERNOON...AN UPPER LEVEL LOW IS MEANDERING ALONG THE
GULF COAST WHILE THE EASTERN EXTENT OF AN UPPER LEVEL RIDGE CENTERED
NEAR THE FOUR CORNERS REGION EXTENDS INTO THE LOWER OH VALLEY REGION.
A SHORTWAVE IS ROTATING ACROSS THE NORTHERN GREAT LAKES AND ONTARIO
WITH ANOTHER UPSTREAM ENTERING NORTHWEST ONTARIO.
THE SHORTWAVES WILL COMBINE TO HELP FORM AN EASTERN CONUS TROUGH
THROUGH THE PERIOD WHILE THE RIDGE AMPLIFIES ACROSS THE ROCKIES. A
SFC LOW ASSOCIATED WITH THE DEVELOPING TROUGH WILL TRACK FROM JUST
NORTH OF THE NORTHERN GREAT LAKES AND INTO THE MARITIMES THROUGH WED
NIGHT WITH THE DEVELOPING TROUGH AND NORTHWEST FLOW PUSHING THE
TRAILING COLD FRONT INTO THE OH VALLEY LATE TONIGHT INTO THE DAY ON
WED. THIS FRONT WILL GRADUALLY CROSS THE REGION LATE ON WED AFTERNOON
INTO WED EVENING.
IN THE MEANTIME...ISOLATED SHOWERS AND POSSIBLY A STRAY THUNDERSTORM
WILL REMAIN POSSIBLE MAINLY UNTIL NEAR SUNSET AND DAYTIME HEATING IS
LOST. THERE WILL BE SOME MINOR HEIGHT FALLS OVERNIGHT AND WITH A
MOIST AIR MASS IN PLACE...A STRAY SHOWER CANNOT BE RULED OUT
OVERNIGHT...BUT THIS WOULD BE FEW AND FAR BETWEEN OTHERWISE...THE
CONSECUTIVELY DRIVEN CU SHOULD DISSIPATE OVERNIGHT AND PATCHY RIVER
VALLEY FOG IS AGAIN ANTICIPATED.
MORE ORGANIZED CONVECTION IS ANTICIPATED AS THE FRONT APPROACHES AND
CROSSES THE REGION AND THE UPPER LEVEL TROUGH DEVELOPS OVER THE
EASTERN CONUS. THIS FRONT AND UPPER LEVEL FORCING FROM THE DEVELOPING
TROUGH WILL INTERACT WITH A MOIST PREFONTAL AIR MASS TO BRING MORE
ORGANIZED CONVECTION TO THE REGION FROM WED AFTERNOON INTO WED NIGHT.
MORNING HEATING WILL BE DE PENDANT ON HOW MUCH CLOUD COVER THERE IS IN
THE AM AND THIS WILL ULTIMATELY DETERMINE INSTABILITY. MODERATE
INSTABILITY IS ANTICIPATED WITH TEMPS IN THE MID 80S TO AROUND 90 AND
DEWPOINTS IN THE UPPER 60S TO AROUND 70. THE LOW LEVEL GRADIENT WILL
BE RATHER WEAK AND SO WILL THE WINDS WHILE THE UPPER LEVEL WINDS WILL
NOT BE ALL THAT STRONG SO SHEAR WILL BE WEAK. PWS IS PROGGED TO CLIMB
1.5 TO 1.8 INCH RANGE FROM MIDDAY WED INTO WED NIGHT...SO STORMS
SHOULD BE ABLE TO PRODUCE LOCALLY HEAVY RAIN. A STRONGER STORM OR TWO
MIGHT ALSO BE ABLE TO PRODUCE STRONG WIND GUSTS. ONCE THE FRONT
CROSSES THE REGION...INSTABILITY WILL DIMINISH AND THE THREAT FOR
THUNDER SHOULD ALSO DIMINISH LATE WED NIGHT.
TEMPS WILL CONTINUE TO BE ABOVE NORMAL THROUGH THE PERIOD...BUT A
COLDER AND DRIER AIR MASS WILL ALREADY BE STARTING TO ADVECT INTO THE
AREA LATE IN THE PERIOD.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 348 AM EDT TUE JUL 22 2014
THE MODELS ARE IN ONLY FAIR AGREEMENT ALOFT THROUGH THE EXTENDED
PORTION OF THE FORECAST. WHILE THEY ALL DEPICT THE ABNORMAL PATTERN
OF A STRONG FOUR CORNERS REGION RIDGE AND DEEP TROUGHING IN THE EAST
CONTINUING THROUGH THE END OF THE WEEK AND INTO THE START OF THE
NEXT WEEK...THEY DIFFER ON THE MAGNITUDE AND TIMING OF THE EVOLVING
EASTERN TROUGH...PARTICULARLY OVER THE WEEKEND AND INTO MONDAY.
SPECIFICALLY...FALLING HEIGHTS OVER KENTUCKY WILL BE THE RULE INTO
THURSDAY NIGHT AS THE RETROGRADING LOW TO THE SOUTH PULLS AWAY AND
THE NORTHERN STREAM SENDS A SERIES OF SHORTWAVES THROUGH THE AREA IN
NORTHWEST FLOW. THIS EASTERN TROUGH PULLS AWAY TO START THE WEEKEND
WITH HEIGHTS CLIMBING TEMPORARILY BEFORE THEY FALL AGAIN IN THE FACE
OF A NODE OF THE LARGE NORTHEAST TROUGH GEARING UP FOR A DIVE INTO
THE UPPER MIDWEST AND OHIO VALLEY. THE 00Z GFS IS MOST AGGRESSIVE
WITH THIS EVOLUTION WHILE THE 12 ECMWF KEEPS ITS CORE WAVE FURTHER
TO THE NORTHWEST AND LAGS THE GFS DEVELOPMENT. HOWEVER...THE LATEST
CMC AND ECMWF ARE TRENDING MORE TOWARD THE GFS. REGARDLESS...
NORTHWEST FLOW WILL DOMINATE THE LOCAL PATTERN AS HEIGHTS FALL INTO
MONDAY MORNING. EVENTUALLY...THE ECMWF CATCHES UP...WITH THE DEEPER
AND MORE WESTERN TROUGH IDEA OF THE GFS BUT SOME SIGNIFICANT
DIFFERENCES REMAIN WITH THE PATTERN OVER THE OHIO VALLEY TO CLOSE
OUT THE WEEK. THE BETTER AGREEMENT EARLIER IN THE EXTENDED SUPPORTS
A BLENDED SOLUTION WHILE THE LARGER SPREAD LATER ON LOWERS
CONFIDENCE SO THAT THE ENSEMBLES AND A SLIGHT LEAN TOWARD THE GFS
ARE PREFERRED SOLUTIONS.
SENSIBLE WEATHER WILL FEATURE AN APPROACHING COLD FRONT SERVING AS A
FOCUSING MECHANISM FOR SHOWERS AND THUNDERSTORMS WEDNESDAY NIGHT
INTO THURSDAY. COOLER AND DRIER AIR WILL FILTER INTO THIS PART OF
THE STATE LATER IN THE DAY THURSDAY PUTTING AN END TO THE CONVECTIVE
CHANCES FROM NORTHWEST TO SOUTHEAST. DRY AND RELATIVELY COOL WEATHER
FOLLOWS INTO THE START OF THE WEEKEND THANKS TO A BRIEF VISIT OF
HIGH PRESSURE. HOWEVER...THE COLD FRONT THAT BROUGHT THE DRIER
WEATHER WILL START TO SURGE NORTH OVER THE WESTERN PARTS OF THE
REGION AND BRING WARMTH...MOISTURE...AND BETTER CONVECTIVE CHANCES
BACK INTO THE AREA ON SATURDAY. A SERIES OF SHORT WAVES AT MID
LEVELS...THE DEVELOPING TROUGH...AND THE SFC FRONTAL STRUCTURE OVER
THE OHIO VALLEY KEEP SHOWER AND THUNDERSTORM CHANCES GOING INTO
SUNDAY AND MONDAY.
THE CR GRID LOAD PROVIDED A DECENT START TO THE FORECAST FOR THE
EXTENDED...THOUGH DID ADJUST THE POPS TO ADD A TINGE OF DIURNAL TO
THE TIMING OF THE CONVECTION. ALSO...TWEAKED THE LOW TEMPERATURE
GRIDS A TAD TO REFLECT RIDGE AND VALLEY DIFFERENCES WEDNESDAY AND
THURSDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 139 AM EDT WED JUL 23 2014
SKIES ARE CLEARING OUT ACROSS THE AREA AND WITH SOUTHWESTERLY FLOW
BRINGING IN MOIST AIR...SOME FOG WILL DEVELOP IN THE MORNING HOURS.
TAF SITES SHOULD GO DOWN TO AT LEAST MVFR IF NOT SOME IFR TOWARDS
DAWN. JKL IS MORE LIKELY TO SOME VALLEY FOG ADVECTED IN ON STATION.
HEADING INTO THE DAY...CLOUD COVER WILL BE ON THE INCREASE AS A COLD
FRONT MOVES THROUGH. HAVE PUT THUNDER IN THE TAF SITES AND ON STATION
BY 19Z AS THE BEST CHANCE FOR THUNDERSTORMS WILL BE DURING THE
AFTERNOON TOWARDS THE EVENING WITH THE FRONT APPROACHING AS WELL.
MOST LOCATIONS SHOULD GO DOWN TO IFR CONDITIONS WITH THIS DURATION OF
PRECIP. CEILINGS SHOULD THEN BE IFR THROUGH THE REST OF THE TAF
PERIOD AS WELL. WINDS SHOULD BR LIGHT BUT INCREASE OUT OF THE WEST
WITH THE FRONT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...JP
LONG TERM...GREIF
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
555 PM CDT WED JUL 23 2014
.AVIATION...
WOW...JUST AMENDED KTXK...HOPE IT IS ENOUGH AS GUSTS TO 91KTS
COMING DOWN THE PIPE. A LARGE WIDESPREAD OPEN ENDED DERECHO IS
NEARLY ENTERING THE CITY LIMITS WITH WIDE SPREAD GUSTS OVER 60KTS.
OUR RADAR IS NOW IN THE PURPLE HAZE LAST SCAN. LOOK FOR MANY
TERMINALS TO BE EFFECTED THIS EVENING WITH MANY AMENDMENTS YET TO
COME EVEN IN THE NEW ISSUANCE. WE WILL MONITOR CLOSELY...BUT THE
NON AMENDMENTS PERIOD IS NEARLY UPON US. THE GOOD NEWS IS THAT
TOPS ARE WANNING NOW IN THE LATE AFTERNOON HEAT OF THE DAY. WHY
ALOFT WE ARE NE THROUGHOUT THE COLUMN...45KTS PEAK SO FAR AT KTXK.
/24/
&&
.PREV DISCUSSION... /ISSUED 340 PM CDT WED JUL 23 2014/
DISCUSSION...
SVR MCS ONGOING THIS AFTERNOON ACROSS ERN OK/WRN AND CNTRL
AR...WITH THE CNTRL AR CONVECTION EXPECTED TO MERGE INTO THE BOW
ECHO RIDING S ALONG THE OK/AR LINE. SBCAPES ARE VERY UNSTABLE THIS
AFTERNOON...WITH 4500-5000+ J/KG NOTED JUST S OF THIS
COMPLEX...WHERE STRONG HEATING AND LOW LEVEL MOISTURE POOLING
ALONG/JUST AHEAD OF A SFC TROUGH WHICH HAS BEEN CONVECTIVELY
REINFORCED OVER NRN/ERN OK INTO CNTRL AR. HAVE NOTICED A TREND OF
INCREASING INSTABILITY S OF THE RED RIVER ACROSS EXTREME NE TX/SW
AR...THUS HAVE ADDED SVR MENTION INTO THE FORECAST THIS EVENING AS
THIS MCS CONTINUES SWD BEFORE GRADUALLY WEAKENING WITH THE LOSS OF
HEATING. HOWEVER...ITS FORWARD MOMENTUM MAY KEEP THIS LINE
STRONG/POSSIBLY SVR PERHAPS AS FAR S AS I-30...IF NOT EVEN FARTHER
S TOWARDS TYR/GGG BEFORE DISSIPATING. THE HRRR INITIALIZED WELL
THIS MORNING ON THE SE KS CONVECTION AND REMAINS CONSISTENT
PROPAGATING THIS MCS SSWWD ACROSS NE TX/SW AR BEFORE
WEAKENING...ALTHOUGH PORTIONS OF EXTREME NW LA CAN/T BE RULED OUT
COMPLETELY.
AFTERWARDS...THE SFC TROUGH REMAINS PROGGED TO SLOWLY DRIFT S INTO
EXTREME SE OK/NRN SECTIONS OF SW AR BY 12Z THURSDAY...AND SLOWLY
BACKDOORING SW INTO N LA/NE TX BY AFTERNOON BEFORE BECOMING
STATIONARY. THIS REMAINS CONSISTENT WITH THE AFTERNOON PROGS
TUESDAY...WITH THIS BNDRY LIKELY CONTRIBUTING TO COMPRESSIONAL
WARMING NEAR AND S OF IT OVER NE TX/N LA. IT IS POSSIBLE THAT LOW
LEVEL MOISTURE POOLING COULD BE AN ISSUE ALONG THIS BNDRY AS HAS
BEEN THE CASE TODAY FARTHER N...WHICH COULD RESULT IN HEAT INDICES
NEAR 105 DEGREES THURSDAY AFTERNOON. BUT GIVEN THE UNCERTAINTY AS
TO THE EFFECT OF THE ONGOING CONVECTION WILL HAVE ON THE CURRENT
AIR MASS...HAVE OPTED NOT TO INCLUDE A HEAT ADVISORY FOR PORTIONS
OF THE REGION. AS HAS BEEN THE CASE TODAY...THE SFC TROUGH MAY
FOCUS SCT CONVECTION THURSDAY AFTERNOON MAINLY OVER PORTIONS OF
EXTREME ERN TX/N LA. DEPENDING ON THE EXTENT OF INSTABILITY
PRESENT GIVEN THE COMPRESSIONAL WARMING/POTENTIAL LOW LEVEL
MOISTURE POOLING...CAN/T RULE OUT AN ISOLATED SVR STORM
THREAT...ALTHOUGH THIS POTENTIAL MAY BE MINIMIZED GIVEN THE LACK
OF AN UPPER LEVEL FOCUS/SLIGHTLY WEAKER BULK SHEAR. HAVE
MAINTAINED LOW CHANCE POPS S OF THE TROUGH...WITH SLIGHT CHANCE
POPS NEAR AND N OF IT...WITH ANY CONVECTION EXPECTED TO WIND DOWN
THURSDAY EVENING WITH THE LOSS OF HEATING.
AFTERWARDS...THE UPPER LEVEL RIDGE CENTERED OVER THE FOUR CORNERS
REGION WILL EXPAND E ACROSS THE PLAINS INTO THE MS VALLEY...DIALING
UP THE HEAT AND ELIMINATING RAIN CHANCES FOR THE WEEKEND. MAX
TEMPS SHOULD NEAR THE CENTURY MARK ESPECIALLY OVER E TX THIS
WEEKEND...WITH THE RIDGE EXPECTED TO SLOWLY RETROGRADE BACK TO THE
W EARLY NEXT WEEK IN RESPONSE TO THE NEXT LONGWAVE TROUGH THAT
WILL DIG SE ACROSS THE NRN PLAINS AND MS VALLEY. THIS TROUGH WILL
EVENTUALLY HELP TO USHER IN ANOTHER UNUSUAL JULY COOL FRONT LATE
MONDAY THROUGH TUESDAY. HOWEVER...IT APPEARS MOISTURE AND UPPER
LEVEL FORCING WILL BE LIMITED WITH THIS FROPA...ALTHOUGH COOLER
AND DRIER AIR SHOULD SPILL SWD FOR THE MID AND LATE WEEK
TIMEFRAME. BOTH THE GFS AND ECMWF ARE CONSISTENT THOUGH IN THE
DEVELOPMENT OF A SHORTWAVE TROUGH OVER THE SRN PLAINS
WEDNESDAY...WHICH MAY RESULT IN SCT CONVECTION AFFECTING THE
REGION BY THE END OF THE EXTENDED. THESE COOLER TEMPS LOOK TO
LINGER AS WE ENTER AUGUST.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 74 96 75 96 75 / 20 30 10 10 0
MLU 72 93 70 93 73 / 20 30 10 10 0
DEQ 72 93 70 96 72 / 40 20 10 10 0
TXK 73 94 70 95 74 / 40 20 10 10 0
ELD 72 93 68 93 72 / 30 20 10 10 0
TYR 74 97 76 98 76 / 30 20 10 10 0
GGG 73 95 75 96 75 / 30 20 10 10 0
LFK 74 97 75 97 75 / 20 20 20 10 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
24/99/99
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
340 PM CDT WED JUL 23 2014
.DISCUSSION...
SVR MCS ONGOING THIS AFTERNOON ACROSS ERN OK/WRN AND CNTRL
AR...WITH THE CNTRL AR CONVECTION EXPECTED TO MERGE INTO THE BOW
ECHO RIDING S ALONG THE OK/AR LINE. SBCAPES ARE VERY UNSTABLE THIS
AFTERNOON...WITH 4500-5000+ J/KG NOTED JUST S OF THIS
COMPLEX...WHERE STRONG HEATING AND LOW LEVEL MOISTURE POOLING
ALONG/JUST AHEAD OF A SFC TROUGH WHICH HAS BEEN CONVECTIVELY
REINFORCED OVER NRN/ERN OK INTO CNTRL AR. HAVE NOTICED A TREND OF
INCREASING INSTABILITY S OF THE RED RIVER ACROSS EXTREME NE TX/SW
AR...THUS HAVE ADDED SVR MENTION INTO THE FORECAST THIS EVENING AS
THIS MCS CONTINUES SWD BEFORE GRADUALLY WEAKENING WITH THE LOSS OF
HEATING. HOWEVER...ITS FORWARD MOMENTUM MAY KEEP THIS LINE
STRONG/POSSIBLY SVR PERHAPS AS FAR S AS I-30...IF NOT EVEN FARTHER
S TOWARDS TYR/GGG BEFORE DISSIPATING. THE HRRR INITIALIZED WELL
THIS MORNING ON THE SE KS CONVECTION AND REMAINS CONSISTENT
PROPAGATING THIS MCS SSWWD ACROSS NE TX/SW AR BEFORE
WEAKENING...ALTHOUGH PORTIONS OF EXTREME NW LA CAN/T BE RULED OUT
COMPLETELY.
AFTERWARDS...THE SFC TROUGH REMAINS PROGGED TO SLOWLY DRIFT S INTO
EXTREME SE OK/NRN SECTIONS OF SW AR BY 12Z THURSDAY...AND SLOWLY
BACKDOORING SW INTO N LA/NE TX BY AFTERNOON BEFORE BECOMING
STATIONARY. THIS REMAINS CONSISTENT WITH THE AFTERNOON PROGS
TUESDAY...WITH THIS BNDRY LIKELY CONTRIBUTING TO COMPRESSIONAL
WARMING NEAR AND S OF IT OVER NE TX/N LA. IT IS POSSIBLE THAT LOW
LEVEL MOISTURE POOLING COULD BE AN ISSUE ALONG THIS BNDRY AS HAS
BEEN THE CASE TODAY FARTHER N...WHICH COULD RESULT IN HEAT INDICES
NEAR 105 DEGREES THURSDAY AFTERNOON. BUT GIVEN THE UNCERTAINTY AS
TO THE EFFECT OF THE ONGOING CONVECTION WILL HAVE ON THE CURRENT
AIR MASS...HAVE OPTED NOT TO INCLUDE A HEAT ADVISORY FOR PORTIONS
OF THE REGION. AS HAS BEEN THE CASE TODAY...THE SFC TROUGH MAY
FOCUS SCT CONVECTION THURSDAY AFTERNOON MAINLY OVER PORTIONS OF
EXTREME ERN TX/N LA. DEPENDING ON THE EXTENT OF INSTABILITY
PRESENT GIVEN THE COMPRESSIONAL WARMING/POTENTIAL LOW LEVEL
MOISTURE POOLING...CAN/T RULE OUT AN ISOLATED SVR STORM
THREAT...ALTHOUGH THIS POTENTIAL MAY BE MINIMIZED GIVEN THE LACK
OF AN UPPER LEVEL FOCUS/SLIGHTLY WEAKER BULK SHEAR. HAVE
MAINTAINED LOW CHANCE POPS S OF THE TROUGH...WITH SLIGHT CHANCE
POPS NEAR AND N OF IT...WITH ANY CONVECTION EXPECTED TO WIND DOWN
THURSDAY EVENING WITH THE LOSS OF HEATING.
AFTERWARDS...THE UPPER LEVEL RIDGE CENTERED OVER THE FOUR CORNERS
REGION WILL EXPAND E ACROSS THE PLAINS INTO THE MS VALLEY...DIALING
UP THE HEAT AND ELIMINATING RAIN CHANCES FOR THE WEEKEND. MAX
TEMPS SHOULD NEAR THE CENTURY MARK ESPECIALLY OVER E TX THIS
WEEKEND...WITH THE RIDGE EXPECTED TO SLOWLY RETROGRADE BACK TO THE
W EARLY NEXT WEEK IN RESPONSE TO THE NEXT LONGWAVE TROUGH THAT
WILL DIG SE ACROSS THE NRN PLAINS AND MS VALLEY. THIS TROUGH WILL
EVENTUALLY HELP TO USHER IN ANOTHER UNUSUAL JULY COOL FRONT LATE
MONDAY THROUGH TUESDAY. HOWEVER...IT APPEARS MOISTURE AND UPPER
LEVEL FORCING WILL BE LIMITED WITH THIS FROPA...ALTHOUGH COOLER
AND DRIER AIR SHOULD SPILL SWD FOR THE MID AND LATE WEEK
TIMEFRAME. BOTH THE GFS AND ECMWF ARE CONSISTENT THOUGH IN THE
DEVELOPMENT OF A SHORTWAVE TROUGH OVER THE SRN PLAINS
WEDNESDAY...WHICH MAY RESULT IN SCT CONVECTION AFFECTING THE
REGION BY THE END OF THE EXTENDED. THESE COOLER TEMPS LOOK TO
LINGER AS WE ENTER AUGUST.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 74 96 75 96 75 / 20 30 10 10 0
MLU 72 93 70 93 73 / 20 30 10 10 0
DEQ 72 93 70 96 72 / 40 20 10 10 0
TXK 73 94 70 95 74 / 40 20 10 10 0
ELD 72 93 68 93 72 / 30 20 10 10 0
TYR 74 97 76 98 76 / 30 20 10 10 0
GGG 73 95 75 96 75 / 30 20 10 10 0
LFK 74 97 75 97 75 / 20 20 20 10 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION...UPDATED
NWS SHREVEPORT LA
112 PM CDT WED JUL 23 2014
.UPDATE...
ZONE UPDATE JUST SENT TO INCLUDE SVR WATCH 431 FOR MCCURTAIN
COUNTY OK AS WELL AS LITTLE RIVER/SEVIER/HOWARD COUNTIES IN SW AR
THROUGH 01Z. SEE PREVIOUS DISCUSSION BELOW ISSUED AT 1137 AM FOR
REASONING.
15
&&
.AVIATION...
VFR FLIGHT CONDITIONS PERSIST ACROSS THE ARKLATEX THIS
AFTERNOON...AND THIS WILL LIKELY CONTINUE TO PREVAIL IN AREA TAFS.
SOME SCATTERED TSRA ACTIVITY MAY BE OBSERVED BETWEEN 20Z AND 01Z
ALONG AND NORTH OF THE I30 CORRIDOR...SO WE MAY HAVE TO AMD TXK FOR
THUNDERSTORMS IF THEY DEVELOP. OTHERWISE LIGHT WINDS AND VFR
CONDITIONS WILL PERSIST THROUGH THE 18Z TAF PERIOD. /11/
&&
.PREV DISCUSSION... /ISSUED 1137 AM CDT WED JUL 23 2014/
DISCUSSION...
AM EYEING TWO FEATURES THIS MORNING...ONE IS THE UPPER LOW CENTERED
OVER SE LA...AND THE SECOND IS A WEAK TROUGH AXIS SLIDING SWD ACROSS
THE MID MS VALLEY. THE SHORT TERM PROGS ARE IN GOOD AGREEMENT KEEPING
THE UPPER LOW STATIONARY THROUGH THE AFTERNOON...WITH SCT CONVECTION
EXPECTED TO FIRE BY AFTERNOON ON THE NW PERIPHERY OF THE
LOW...AFFECTING PRIMARILY THE SE SECTIONS OF NCNTRL LA. ALREADY SEEING
SOME LIGHT ELEVATED RADAR RETURNS NOW ALONG AND E OF THE MS
RIVER...WITH THIS CONVECTION EXPECTED TO SPREAD SW THROUGH THE
AFTERNOON. HOWEVER...PRIMARY FOCUS IS FARTHER TO THE N...WHERE THE
TROUGH AXIS SHOULD SHEAR SW INTO CNTRL AR AND POSSIBLY EXTREME SE
OK/NE TX THIS AFTERNOON. MOSAIC RADAR INDICATES ISOLATED CONVECTION
DEVELOPING JUST W OF LIT...JUST AHEAD OF A WEAK SFC TROUGH OVER NE OK
INTO NRN AR...IN VC OF THIS SHEARING TROUGH. THE WRF AND HRRR ARE
AGGRESSIVE IN DEVELOPING SCT CONVECTION BY EARLY/MID AFTERNOON OVER
WRN AR/SE OK...AND SLIDING SW AROUND THE PERIPHERY OF THE UPPER RIDGE
INTO EXTREME NE TX. IN ADDITION...THE SMALL COMPLEX OF CONVECTION
OVER SE KS COULD ACTUALLY PLAY A ROLE IN INTENSIFYING CONVECTION
THIS AFTERNOON OVER SE OK/WRN AR AS IT COULD BECOME ABSORBED INTO
THE CONVECTION FARTHER E...BEFORE ACCELERATING SW. DON/T BELIEVE THE
SFC TROUGH WILL MAKE MUCH PROGRESS S DURING THE AFTERNOON UNLESS
BEING REINFORCED SWD FROM THE STORMS...WITH CONVECTION BECOMING
OUTFLOW DOMINANT AND RIDING THE MEAN FLOW AS IT FOLLOWS THE BETTER
INSTABILITY OVER THE NRN ZONES. GIVEN THE MODERATE/STRONG
INSTABILITY IN PLACE OVER ERN OK/WRN AR WHERE LOW LEVEL MOISTURE
POOLING IS IN PLACE NEAR THE SFC TROUGH /WITH TEMPS HAVING ALREADY
REACHED NEAR 90 ALREADY/...CAN/T RULE OUT A SMALL COMPLEX OF SVR
CONVECTION DEVELOPING AND AFFECTING AREAS ALONG/N OF THE I-30
CORRIDOR. A CAVEAT THOUGH WOULD BE THE SWWD EXTENT OF THE CONVECTION
LATE THIS AFTERNOON...AS IT COULD ENCOUNTER LESS INSTABILITY
/THROUGH SUFFICIENT MIXING/ AS IT REACHES THE I-30 CORRIDOR OF NE TX
AND BECOMES MORE REMOVED FROM THE SHEAR AXIS ALOFT.
HAVE INCREASED POPS TO MID CHANCE THIS AFTERNOON FOR EXTREME NE TX/SE
OK/SW AR...WHILE ALSO EXPANDING SLIGHT CHANCE POPS TO COVER THE I-20
CORRIDOR OF E TX/N LA IN CASE THIS CONVECTION DOES MATERIALIZE AND
SENDS OUTFLOW BNDRYS SWD. 16Z TEMPS HAVE ALSO QUICKLY CLIMBED TO THE
MID/UPPER 80S...AND HAVE BUMPED MAX TEMPS UP A DEGREE OR TWO
ESPECIALLY OVER NE TX/NW LA. OTHERWISE...THE REMAINDER OF THE FORECAST
IS ON TRACK.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 94 72 95 72 96 / 20 20 20 10 10
MLU 93 71 93 69 93 / 20 20 20 20 10
DEQ 92 70 94 68 95 / 40 30 0 10 0
TXK 93 72 94 70 95 / 40 30 10 10 0
ELD 93 71 93 69 94 / 20 20 20 10 0
TYR 95 74 97 75 97 / 20 20 20 10 0
GGG 94 73 96 74 97 / 20 20 20 10 0
LFK 95 74 95 76 96 / 30 20 30 20 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION...UPDATED
NWS SHREVEPORT LA
1137 AM CDT WED JUL 23 2014
.DISCUSSION...
AM EYEING TWO FEATURES THIS MORNING...ONE IS THE UPPER LOW CENTERED
OVER SE LA...AND THE SECOND IS A WEAK TROUGH AXIS SLIDING SWD ACROSS
THE MID MS VALLEY. THE SHORT TERM PROGS ARE IN GOOD AGREEMENT KEEPING
THE UPPER LOW STATIONARY THROUGH THE AFTERNOON...WITH SCT CONVECTION
EXPECTED TO FIRE BY AFTERNOON ON THE NW PERIPHERY OF THE
LOW...AFFECTING PRIMARILY THE SE SECTIONS OF NCNTRL LA. ALREADY SEEING
SOME LIGHT ELEVATED RADAR RETURNS NOW ALONG AND E OF THE MS
RIVER...WITH THIS CONVECTION EXPECTED TO SPREAD SW THROUGH THE
AFTERNOON. HOWEVER...PRIMARY FOCUS IS FARTHER TO THE N...WHERE THE
TROUGH AXIS SHOULD SHEAR SW INTO CNTRL AR AND POSSIBLY EXTREME SE
OK/NE TX THIS AFTERNOON. MOSAIC RADAR INDICATES ISOLATED CONVECTION
DEVELOPING JUST W OF LIT...JUST AHEAD OF A WEAK SFC TROUGH OVER NE OK
INTO NRN AR...IN VC OF THIS SHEARING TROUGH. THE WRF AND HRRR ARE
AGGRESSIVE IN DEVELOPING SCT CONVECTION BY EARLY/MID AFTERNOON OVER
WRN AR/SE OK...AND SLIDING SW AROUND THE PERIPHERY OF THE UPPER RIDGE
INTO EXTREME NE TX. IN ADDITION...THE SMALL COMPLEX OF CONVECTION
OVER SE KS COULD ACTUALLY PLAY A ROLE IN INTENSIFYING CONVECTION
THIS AFTERNOON OVER SE OK/WRN AR AS IT COULD BECOME ABSORBED INTO
THE CONVECTION FARTHER E...BEFORE ACCELERATING SW. DON/T BELIEVE THE
SFC TROUGH WILL MAKE MUCH PROGRESS S DURING THE AFTERNOON UNLESS
BEING REINFORCED SWD FROM THE STORMS...WITH CONVECTION BECOMING
OUTFLOW DOMINANT AND RIDING THE MEAN FLOW AS IT FOLLOWS THE BETTER
INSTABILITY OVER THE NRN ZONES. GIVEN THE MODERATE/STRONG
INSTABILITY IN PLACE OVER ERN OK/WRN AR WHERE LOW LEVEL MOISTURE
POOLING IS IN PLACE NEAR THE SFC TROUGH /WITH TEMPS HAVING ALREADY
REACHED NEAR 90 ALREADY/...CAN/T RULE OUT A SMALL COMPLEX OF SVR
CONVECTION DEVELOPING AND AFFECTING AREAS ALONG/N OF THE I-30
CORRIDOR. A CAVEAT THOUGH WOULD BE THE SWWD EXTENT OF THE CONVECTION
LATE THIS AFTERNOON...AS IT COULD ENCOUNTER LESS INSTABILITY
/THROUGH SUFFICIENT MIXING/ AS IT REACHES THE I-30 CORRIDOR OF NE TX
AND BECOMES MORE REMOVED FROM THE SHEAR AXIS ALOFT.
HAVE INCREASED POPS TO MID CHANCE THIS AFTERNOON FOR EXTREME NE TX/SE
OK/SW AR...WHILE ALSO EXPANDING SLIGHT CHANCE POPS TO COVER THE I-20
CORRIDOR OF E TX/N LA IN CASE THIS CONVECTION DOES MATERIALIZE AND
SENDS OUTFLOW BNDRYS SWD. 16Z TEMPS HAVE ALSO QUICKLY CLIMBED TO THE
MID/UPPER 80S...AND HAVE BUMPED MAX TEMPS UP A DEGREE OR TWO
ESPECIALLY OVER NE TX/NW LA. OTHERWISE...THE REMAINDER OF THE FORECAST
IS ON TRACK.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 94 72 95 72 96 / 20 20 20 10 10
MLU 93 71 93 69 93 / 20 20 20 20 10
DEQ 92 70 94 68 95 / 40 30 0 10 0
TXK 93 72 94 70 95 / 40 30 10 10 0
ELD 93 71 93 69 94 / 20 20 20 10 0
TYR 95 74 97 75 97 / 20 20 20 10 0
GGG 94 73 96 74 97 / 20 20 20 10 0
LFK 95 74 95 76 96 / 30 20 30 20 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1123 AM CDT WED JUL 23 2014
.DISCUSSION...
AM EYEING TWO FEATURES THIS MORNING...ONE IS THE UPPER LOW CENTERED
OVER SE LA...AND THE SECOND IS A WEAK TROUGH AXIS SLIDING SWD ACROSS
THE MID MS VALLEY. THE SHORT TERM PROGS ARE IN GOOD AGREEMENT KEEPING
THE UPPER LOW STATIONARY THROUGH THE AFTERNOON...WITH SCT CONVECTION
EXPECTED TO FIRE BY AFTERNOON ON THE NW PERIPHERY OF THE
LOW...AFFECTING PRIMARILY THE SE SECTIONS OF NCNTRL LA. ALREADY SEEING
SOME LIGHT ELEVATED RADAR RETURNS NOW ALONG AND E OF THE MS
RIVER...WITH THIS CONVECTION EXPECTED TO SPREAD SW THROUGH THE
AFTERNOON. HOWEVER...PRIMARY FOCUS IS FARTHER TO THE N...WHERE THE
TROUGH AXIS SHOULD SHEAR SW INTO CNTRL AR AND POSSIBLY EXTREME SE
OK/NE TX THIS AFTERNOON. MOSAIC RADAR INDICATES ISOLATED CONVECTION
DEVELOPING JUST W OF LIT...JUST AHEAD OF A WEAK SFC TROUGH OVER NE OK
INTO NRN AR...IN VC OF THIS SHEARING TROUGH. THE WRF AND HRRR ARE
AGGRESSIVE IN DEVELOPING SCT CONVECTION BY EARLY/MID AFTERNOON OVER
WRN AR/SE OK...AND SLIDING SW AROUND THE PERIPHERY OF THE UPPER RIDGE
INTO EXTREME NE TX. DON/T BELIEVE THE SFC TROUGH WILL MAKE MUCH
PROGRESS S DURING THE AFTERNOON...WITH CONVECTION BECOMING OUTFLOW
DOMINANT AND RIDING THE MEAN FLOW AS IT FOLLOWS THE BETTER INSTABILITY
OVER THE NRN ZONES. A CAVEAT THOUGH WOULD BE THE SWWD EXTENT OF THE
CONVECTION LATE THIS AFTERNOON...AS IT COULD ENCOUNTER LESS
INSTABILITY /THROUGH SUFFICIENT MIXING/ AS IT REACHES THE I-30
CORRIDOR OF NE TX AND BECOMES MORE REMOVED FROM THE SHEAR AXIS ALOFT.
HAVE INCREASED POPS TO MID CHANCE THIS AFTERNOON FOR EXTREME NE TX/SE
OK/SW AR...WHILE ALSO EXPANDING SLIGHT CHANCE POPS TO COVER THE I-20
CORRIDOR OF E TX/N LA IN CASE THIS CONVECTION DOES MATERIALIZE AND
SENDS OUTFLOW BNDRYS SWD. 16Z TEMPS HAVE ALSO QUICKLY CLIMBED TO THE
MID/UPPER 80S...AND HAVE BUMPED MAX TEMPS UP A DEGREE OR TWO
ESPECIALLY OVER NE TX/NW LA. OTHERWISE...THE REMAINDER OF THE FORECAST
IS ON TRACK.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 94 72 95 72 96 / 20 20 20 10 10
MLU 93 71 93 69 93 / 20 20 20 20 10
DEQ 92 70 94 68 95 / 40 30 0 10 0
TXK 93 72 94 70 95 / 40 30 10 10 0
ELD 93 71 93 69 94 / 20 20 20 10 0
TYR 95 74 97 75 97 / 20 20 20 10 0
GGG 94 73 96 74 97 / 20 20 20 10 0
LFK 95 74 95 76 96 / 30 20 30 20 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
449 PM EDT WED JUL 23 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION TONIGHT AND EXITS
OFFSHORE THURSDAY MORNING. HIGH PRESSURE BUILDS IN FROM THE WEST
FRIDAY AND SATURDAY. WET WEATHER WILL ONCE AGAIN BE POSSIBLE LATE
IN THE WEEKEND AND EARLY NEXT WEEK AS THE NEXT UPPER TROUGH DIVES
IN.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
.UPDATE..
SEVERE THUNDERSTORM WATCH CONTINUES FOR THE ENTIRE AREA THROUGH 10
PM. LINE OF STRONG STORMS ARE NOW MOVING SLOWLY SE THROUGH NH AND
MAINE. AREA OF OUTFLOW NOW MOVING AHEAD OF THE STORMS IN OXFORD
AND CARROLL COUNTIES MAY EVENTUALLY INTERACT WITH THE SEABREEZE IN
ANDROSCOGGIN/ CUMBERLAND COUNTIES. STRONGER/ SEVERE STORMS ARE
LOCATED IN VT AND MAY MOVE INTO NH IN THE NEXT HOUR OR TWO.
ADDITIONAL DEVELOPMENT ALONG A PRE FRONTAL TROUGH IS SUGGESTED BY
THE HRRR MODEL AHEAD OF THE CURRENT LINE OF STORMS. SO FAR THE LACK
OF MOISTURE AT 700MB IS LIKELY THE REASON FOR STORMS NOT REALIZING
THEIR FULL POTENTIAL TODAY...SOMETHING TO BE THANKFUL FOR. SHOULD
BE ABLE TO DROP THE NORTHERN COUNTIES FROM THE WATCH SHORTLY.
ADJUSTED POPS...MAX TEMPERATURE...DEW POINTS...AND WEATHER GRIDS
FOR THIS UPDATE.
&&
PREVIOUS DISCUSSION...
SEVERE THUNDERSTORM WATCH IN EFFECT FOR THE ENTIRE CWA UNTIL 10
PM. THUNDERSTORMS ACROSS FAR NORTHERN ZONES AS WELL AS VT ARE
EXPECTED TO CONTINUE TO DEVELOP AND MOVE FURTHER INTO THE CWA BY
EARLY EVENING. THE MAIN THREAT WILL BE DAMAGING WINDS AND
LOCALIZED FLASH FLOODING. THE CONVECTION SHOULD WEAKEN LATE THIS
EVENING WITH SHOWERS LINGERING FOR THE BALANCE OF THE NIGHT.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
LINGERING SHOWERS ACROSS S AND SE ZONES THROUGH MIDDAY THURS OR
SO...THEN SOME CLEARING TAKES PLACE. A FAIR NIGHT IS IN STORE FOR
THURS NIGHT AS HIGH PRESSURE BUILDS IN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A SLOW MOVING LOW PRESSURE SYSTEM WILL AFFECT THE AREA LATER IN
THE WEEKEND INTO EARLY NEXT WEEK WITH OCCASIONAL SHOWERS AND
POSSIBLY SOME THUNDERSTORMS.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM /THROUGH THURSDAY/...IFR OR LOWER IN SHOWERS AND
THUNDERSTORMS THROUGH THIS EVENING...THEN IMPROVING CONDITIONS ARE
FORESEEN. MAINLY VFR THU NIGHT AND FRI.
LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...IFR CONDITIONS WITH
SCT SHRA/TSTMS LIKELY TO DEVELOP SATURDAY NGT AND SUNDAY.
&&
.MARINE...
SHORT TERM /THROUGH FRIDAY/...SCA FOR TONIGHT FOR THE OCEAN WATERS FOR
MARGINAL 25 KT GUSTS AND SEAS 4-6 FT. QUIETER WINDS AND SEAS THU
THROUGH FRI.
LONG TERM /FRIDAY THROUGH MONDAY/...WINDS AND SEAS BELOW SCA
LEVELS THRU SATURDAY MORNING THEN SOUTHERLY FLOW INCREASES
POSSIBLY PUSHING WINDS AND SEAS TO SCA LEVELS OVER THE OPEN WATERS
LATE SATURDAY THRU SUNDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ150-152-
154.
&&
$$
UPDATE...HANES
AREA FORECAST DISCUSSION...CORRECTED
NWS TWIN CITIES/CHANHASSEN MN
805 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 804 PM CDT THU JUL 24 2014
ONLY UNTIL RECENTLY HAVE MODELS BEGUN TO LATCH ONTO THE CURRENT
SITUATION. HRRR AND NOW HOPWRF HAVE BEGUN TO CONVERGE TOWARD A
SOLUTION WHICH ALLOWS CONVECTION OVER THE WESTERN DAKOTAS AND
EASTERN MONTANA TO EXPAND EASTWARD RAPIDLY DURING THE LATE EVENING
AND SPILL INTO MINNESOTA OVERNIGHT. THE GLOBAL MODELS THROUGH 18Z
DID NOT HANDLE THIS IDEA WELL...SO WHILE CONFIDENCE HAS BEEN QUITE
LOW IT IS STARTING TO INCREASE. IT REMAINS TO BE SEEN WHETHER THE
00Z GLOBAL MODELS WILL LATCH ONTO THIS SOLUTION...BUT GIVEN THE
RECENT TRENDS IN THE CAMS THERE IS A PRETTY GOOD CHANCE.
STRONG MOISTURE ADVECTION OVER EASTERN SOUTH DAKOTA/NEBRASKA WHERE
PW VALUES ARE 1.5 TO 1.9 INCHES WILL CONTINUE TO IMPROVE OVERNIGHT
AS A 40 TO 50 KT LLJ DEVELOPS. THIS LLJ WILL THEN VEER EASTWARD INTO
SWRN MN OVERNIGHT AND FOCUS THIS MOISTURE TRANSPORT OVER THE MPX
CWA. A STRONGLY TO EXTREMELY UNSTABLE AIRMASS TO THE WEST SHOULD
MAINTAIN THIS DEVELOPING MCS AS IT CONTINUES EAST FOR THE NEXT 12
HOURS. THUS...THE SOLUTION KEEPING ACTIVITY CONFINED TO IOWA /A
LA NAM...GFS...AND CMC/ IS LOOKING LESS AND LESS LIKELY. INCREASED
POPS ACROSS CENTRAL MN INTO THE LIKELY RANGE AND THE TIMING WAS
BASED ON THE LATEST HRRR/HOPWRF.
ANY SEVERE THREAT WILL BE DETERMINED BY HOW FAR EAST THE EML AND
ASSOCIATED INSTABILITY CAN PROGRESS. BEST CHANCE FOR ANY SEVERE
WOULD BE ACROSS WRN MN...CLOSEST TO THE EML. LARGE HAIL WOULD BE
THE PRIMARY CONCERN.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 233 PM CDT THU JUL 24 2014
SHORT TERM CONCERNS REMAIN COVERAGE OF THUNDER OVERNIGHT INTO
FRIDAY. ALSO...CHANCE OF LARGE HAIL MAINLY LATER TONIGHT INTO SOUTH
CENTRAL MN WITH SOME SEVERE POTENTIAL LINGERING INTO FRIDAY AHEAD OF
FRONT.
UPPER RIDGE IS BEGINNING TO MOVE EAST WITH ONE IMPULSE DROPPING
SOUTHEAST OVER WESTERN MINNESOTA AND THE NEXT WAVE LIFTING INTO
NORTHWEST NODAK AND SOUTHERN MANITOBA. IT APPEARS THE INITIAL WAVE
WILL DROP SOUTHEAST THIS EVENING ALONG THE EASTERN PERIPHERY OF THE
INSTABILITY GRADIENT TO THE WEST AND THE EDGE OF LOW LEVEL WAA/STEEP
MID LEVEL LAPSE RATES. MODELS DIVERGE ON DEVELOPMENT THEREAFTER...
WITH SEVERAL HIRES MODELS INDICATING CANADIAN SYSTEM TAKES OVER AND
DROPS SOUTHEAST OVERNIGHT. STILL SOME POTENTIAL OF LLJ DRIVING
CONVECTION INTO MAINLY SOUTH CENTRAL MN LATE. WILL CARRY HIGHER
POPS TO THE SOUTH ONCE AGAIN...IN SPIRIT WITH THE PREVIOUS
FORECAST. SHOULD SEE SOME QPF MOVE THROUGH THE MOST OF AREA.
FRIDAY STILL SEE SOME POTENTIAL OF ISOLATED/WIDELY SCATTERED
CONVECTION DEVELOPING ALONG THE FRONT AS IT MOVES ACROSS THE EASTERN
PORTION OF THE AREA INTO THE AFTERNOON. WILL HOLD ONTO SOME LOW END
POPS FOR THIS POTENTIAL. INSTABILITY ALONG THE FRONT DOES INCREASE
DURING THE DAY BUT LOW LEVEL CONVERGENCE REMAINS WEAK. MUCH OF THE
HIGH END FORCING IS DRIVEN EAST DURING THE MORNING AS WELL.
TEMPERATURES SHOULD WARM INTO THE MID 80S TO THE SOUTHWEST WITH MIX
WITH THE WEAK FRONT AND UPPER 70S/LOWER 80S ELSEWHERE.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 233 PM CDT THU JUL 24 2014
MAIN CONCERN IN THE EXTENDED PERIOD IS WHETHER SHRA/TSRA DEVELOP
FURTHER SOUTHWARD ACROSS MN THAN EXPECTED FOR LATE SAT AFTN/EARLY
SUNDAY AS A STRONG...AND UNUSUAL UPPER LOW FOR THIS TIME OF YEAR
MOVES EAST-SE ACROSS THE NORTHERN PLAINS...AND INTO THE WESTERN
GREAT LAKES BY SUNDAY. WILL FOLLOW PREVIOUS FORECAST WITH THE MAIN
AREA OF SHRA ACROSS CENTRAL MN/EC MN AND WC WI WHERE BOTH UPPER
LEVEL ENERGY AND HIGHER RH FIELDS ARE EVIDENT. K-INDEX AND 85H
SHOWALTER INDEX FIELDS INDICATED MAINLY SHRA WITH SOME EMBEDDED
TSRA FOR THE TYPICAL DIURNAL TIME FRAME. SUNDAY MORNING/AFTN WILL
LIKELY BE BREEZY AS THE SFC LOW DEEPENS AS IT MOVES SE ACROSS THE
WESTERN GREAT LAKES IN RESPONSE TO THE UPPER JET.
NO CHGS IN THE EXTENDED PERIOD BEYOND THIS WEEKEND WITH BOTH THE
EC/GFS ADVERTISING A STRONG UPPER RIDGE BUILDING OFF THE EAST
COAST OF NORTH AMERICA WITH A DEEPENING LONG WAVE TROUGH ACROSS
THE EASTERN 1/3 OF THE CONUS. THIS WILL KEEP OUR REGION COOLER
THAN NORMAL AND MAINLY DRY. ALTHOUGH COOLER TEMPS ARE
EXPECTED...STANDARD ANOMALIES ARE NOT TOO IMPRESSIVE COMPARED TO
THE DEEP SE U.S. WHERE ANOMALIES COULD DROP TO 2-3 BLW NORMAL.
FOR COMPARISON...OUR REGION WILL BE SLIGHTLY COOLER...BUT STILL
NICE FOR LATE JULY/EARLY AUGUST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 630 PM CDT THU JUL 24 2014
MUCH TO CONSIDER FOR THIS TAF ISSUANCE. DECAYING SHOWERS ACROSS
SOUTHERN MN HAVE PRODUCED STRONG WINDS AS RECENTLY AS 23Z AT MSP
AND STP WHERE GUSTS OF 35 TO 41 KTS WERE REPORTED. GUSTINESS WILL
SUBSIDE THIS EVENING AS THE BOUNDARY LAYER STABILIZES SOMEWHAT.
STRONG MOISTURE TRANSPORT OVER THE EASTERN DAKOTAS HAVE PRODUCED
MID LEVEL CLOUDS OVER WRN MN AT TAF ISSUANCE TIME...AND COULD
FOSTER DEVELOPMENT OF SHRA THIS EVENING. OTHER CIGS...THE MVFR
VARIETY...HAVE ALSO DEVELOPED NORTHWEST OF MSP ALONG I-94. THESE
APPEAR TO BE SOMEWHAT TRANSIENT...SO MADE MENTION OF IT FOR THE
FIRST HOUR IN STC AND AXN TAFS. WILL NEED TO WATCH FOR FURTHER
EXPANSION. OVERNIGHT...MODELS ARE ALL AT ODDS WITH EACH OTHER WITH
THE POTENTIAL NEXT ROUND OF SHRA/TSRA. THE HRRR MODEL SEEMS TO BE
IMPROVING ITS HANDLE ON CURRENT ACTIVITY OVER IA AND ERN MT...AND
IT SHOWS A BAND OF SHRA/TSRA ARRIVING BETWEEN 06-07Z OVER FAR WRN
MN AND HEADING EAST INTO WRN WI BY 09Z OR 10Z. THIS SEEMS LIKE THE
MOST LIKELY SCENARIO AT THIS POINT...BUT SINCE SO MANY OTHER
MODELS ARE SHOWING LITTLE OR NO ACTIVITY OVERNIGHT WAS ONLY
CONFIDENT ENOUGH TO MENTION A PROB30 ATTM.
KMSP...THE GUSTS HAVE CEASED FOLLOWING THE UNEXPECTED 41 KT GUST
AT 23Z. MOSTLY CLEAR CONDITIONS ARE ANTICIPATED FOR THE REMAINDER
OF THE EVENING...ALTHOUGH THE MVFR CIGS TO THE NORTHWEST ARE A
LITTLE CLOSE TO COMPLETELY IGNORE THE POSSIBILITY OF BRIEF MVFR
CONDITIONS IN THE NEXT COUPLE HOURS. AS MENTIONED IN THE GENERAL
DISCUSSION...CONFIDENCE IS LOW OVERNIGHT FOR THE NEXT ROUND OF
SHRA/TSRA SO KEPT THE TAF AT PROB30. COME THE 03Z AMD...SHOULD
HAVE A BETTER HANDLE ON THE OVERNIGHT FORECAST AND BE ABLE TO
REMOVE COMPLETELY OR REINTRODUCE PREVAILING.
/OUTLOOK FOR KMSP/
SAT...VFR. WINDS WSW AT 5-10KTS.
SUN...VFR. CHANCE SHRA/MVFR CIGS. WINDS NW AT 10-15 KTS.
MON...VFR. WINDS N 5 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...BORGHOFF
SHORT TERM...DWE
LONG TERM...JLT
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
804 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 804 PM CDT THU JUL 24 2014
ONLY UNTIL RECENTLY HAVE MODELS BEGUN TO LATCH ONTO THE CURRENT
SITUATION. HRRR AND NOW HOPWRF HAVE BEGUN TO CONVERGE TOWARD A
SOLUTION WHICH ALLOWS CONVECTION OVER THE WESTERN DAKOTAS AND
EASTERN MONTANA TO EXPAND EASTWARD RAPIDLY DURING THE LATE EVENING
AND SPILL INTO MINNESOTA OVERNIGHT. THE GLOBAL MODELS THROUGH 18Z
DID NOT HANDLE THIS IDEA WELL...SO WHILE CONFIDENCE HAS BEEN QUITE
LOW IT IS STARTING TO INCREASE. IT REMAINS TO BE SEEN WHETHER THE
00Z GLOBAL MODELS WILL LATCH ONTO THIS SOLUTION...BUT GIVEN THE
RECENT TRENDS IN THE CAMS THERE IS A PRETTY GOOD CHANCE.
STRONG MOISTURE ADVECTION OVER EASTERN SOUTH DAKOTA/NEBRASKA WHERE
PW VALUES ARE 1.5 TO 1.9 INCHES WILL CONTINUE TO IMPROVE OVERNIGHT
AS A 40 TO 50 KT LLJ DEVELOPS. THIS LLJ WILL THEN VEER EASTWARD INTO
SWRN MN OVERNIGHT AND FOCUS THIS MOISTURE TRANSPORT OVER THE MPX
CWA. A STRONGLY TO EXTREMELY UNSTABLE AIRMASS TO THE WEST SHOULD
MAINTAIN THIS DEVELOPING MCS AS IT CONTINUES EAST FOR THE NEXT 12
HOURS. THUS...THE SOLUTIONS KEEPING ACTIVITY CONFINED TO IOWA
/A LA NAM...GFS...AND CMC/ IS LOOKING LESS AND LESS LIKELY. INCREASED
POPS ACROSS CENTRAL MN INTO THE LIKELY RANGE AND THE TIMING WAS
BASED ON THE LATEST HRRR/HOPWRF.
ANY SEVERE THREAT WILL BE DETERMINED BY HOW FAR EAST THE EML AND
ASSOCIATED INSTABILITY CAN PROGRESS. BEST CHANCE FOR ANY SEVERE
WOULD BE ACROSS WRN MN...CLOSEST TO THE EML. LARGE HAIL WOULD BE
THE PRIMARY CONCERN.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 233 PM CDT THU JUL 24 2014
SHORT TERM CONCERNS REMAIN COVERAGE OF THUNDER OVERNIGHT INTO
FRIDAY. ALSO...CHANCE OF LARGE HAIL MAINLY LATER TONIGHT INTO SOUTH
CENTRAL MN WITH SOME SEVERE POTENTIAL LINGERING INTO FRIDAY AHEAD OF
FRONT.
UPPER RIDGE IS BEGINNING TO MOVE EAST WITH ONE IMPULSE DROPPING
SOUTHEAST OVER WESTERN MINNESOTA AND THE NEXT WAVE LIFTING INTO
NORTHWEST NODAK AND SOUTHERN MANITOBA. IT APPEARS THE INITIAL WAVE
WILL DROP SOUTHEAST THIS EVENING ALONG THE EASTERN PERIPHERY OF THE
INSTABILITY GRADIENT TO THE WEST AND THE EDGE OF LOW LEVEL WAA/STEEP
MID LEVEL LAPSE RATES. MODELS DIVERGE ON DEVELOPMENT THEREAFTER...
WITH SEVERAL HIRES MODELS INDICATING CANADIAN SYSTEM TAKES OVER AND
DROPS SOUTHEAST OVERNIGHT. STILL SOME POTENTIAL OF LLJ DRIVING
CONVECTION INTO MAINLY SOUTH CENTRAL MN LATE. WILL CARRY HIGHER
POPS TO THE SOUTH ONCE AGAIN...IN SPIRIT WITH THE PREVIOUS
FORECAST. SHOULD SEE SOME QPF MOVE THROUGH THE MOST OF AREA.
FRIDAY STILL SEE SOME POTENTIAL OF ISOLATED/WIDELY SCATTERED
CONVECTION DEVELOPING ALONG THE FRONT AS IT MOVES ACROSS THE EASTERN
PORTION OF THE AREA INTO THE AFTERNOON. WILL HOLD ONTO SOME LOW END
POPS FOR THIS POTENTIAL. INSTABILITY ALONG THE FRONT DOES INCREASE
DURING THE DAY BUT LOW LEVEL CONVERGENCE REMAINS WEAK. MUCH OF THE
HIGH END FORCING IS DRIVEN EAST DURING THE MORNING AS WELL.
TEMPERATURES SHOULD WARM INTO THE MID 80S TO THE SOUTHWEST WITH MIX
WITH THE WEAK FRONT AND UPPER 70S/LOWER 80S ELSEWHERE.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 233 PM CDT THU JUL 24 2014
MAIN CONCERN IN THE EXTENDED PERIOD IS WHETHER SHRA/TSRA DEVELOP
FURTHER SOUTHWARD ACROSS MN THAN EXPECTED FOR LATE SAT AFTN/EARLY
SUNDAY AS A STRONG...AND UNUSUAL UPPER LOW FOR THIS TIME OF YEAR
MOVES EAST-SE ACROSS THE NORTHERN PLAINS...AND INTO THE WESTERN
GREAT LAKES BY SUNDAY. WILL FOLLOW PREVIOUS FORECAST WITH THE MAIN
AREA OF SHRA ACROSS CENTRAL MN/EC MN AND WC WI WHERE BOTH UPPER
LEVEL ENERGY AND HIGHER RH FIELDS ARE EVIDENT. K-INDEX AND 85H
SHOWALTER INDEX FIELDS INDICATED MAINLY SHRA WITH SOME EMBEDDED
TSRA FOR THE TYPICAL DIURNAL TIME FRAME. SUNDAY MORNING/AFTN WILL
LIKELY BE BREEZY AS THE SFC LOW DEEPENS AS IT MOVES SE ACROSS THE
WESTERN GREAT LAKES IN RESPONSE TO THE UPPER JET.
NO CHGS IN THE EXTENDED PERIOD BEYOND THIS WEEKEND WITH BOTH THE
EC/GFS ADVERTISING A STRONG UPPER RIDGE BUILDING OFF THE EAST
COAST OF NORTH AMERICA WITH A DEEPENING LONG WAVE TROUGH ACROSS
THE EASTERN 1/3 OF THE CONUS. THIS WILL KEEP OUR REGION COOLER
THAN NORMAL AND MAINLY DRY. ALTHOUGH COOLER TEMPS ARE
EXPECTED...STANDARD ANOMALIES ARE NOT TOO IMPRESSIVE COMPARED TO
THE DEEP SE U.S. WHERE ANOMALIES COULD DROP TO 2-3 BLW NORMAL.
FOR COMPARISON...OUR REGION WILL BE SLIGHTLY COOLER...BUT STILL
NICE FOR LATE JULY/EARLY AUGUST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 630 PM CDT THU JUL 24 2014
MUCH TO CONSIDER FOR THIS TAF ISSUANCE. DECAYING SHOWERS ACROSS
SOUTHERN MN HAVE PRODUCED STRONG WINDS AS RECENTLY AS 23Z AT MSP
AND STP WHERE GUSTS OF 35 TO 41 KTS WERE REPORTED. GUSTINESS WILL
SUBSIDE THIS EVENING AS THE BOUNDARY LAYER STABILIZES SOMEWHAT.
STRONG MOISTURE TRANSPORT OVER THE EASTERN DAKOTAS HAVE PRODUCED
MID LEVEL CLOUDS OVER WRN MN AT TAF ISSUANCE TIME...AND COULD
FOSTER DEVELOPMENT OF SHRA THIS EVENING. OTHER CIGS...THE MVFR
VARIETY...HAVE ALSO DEVELOPED NORTHWEST OF MSP ALONG I-94. THESE
APPEAR TO BE SOMEWHAT TRANSIENT...SO MADE MENTION OF IT FOR THE
FIRST HOUR IN STC AND AXN TAFS. WILL NEED TO WATCH FOR FURTHER
EXPANSION. OVERNIGHT...MODELS ARE ALL AT ODDS WITH EACH OTHER WITH
THE POTENTIAL NEXT ROUND OF SHRA/TSRA. THE HRRR MODEL SEEMS TO BE
IMPROVING ITS HANDLE ON CURRENT ACTIVITY OVER IA AND ERN MT...AND
IT SHOWS A BAND OF SHRA/TSRA ARRIVING BETWEEN 06-07Z OVER FAR WRN
MN AND HEADING EAST INTO WRN WI BY 09Z OR 10Z. THIS SEEMS LIKE THE
MOST LIKELY SCENARIO AT THIS POINT...BUT SINCE SO MANY OTHER
MODELS ARE SHOWING LITTLE OR NO ACTIVITY OVERNIGHT WAS ONLY
CONFIDENT ENOUGH TO MENTION A PROB30 ATTM.
KMSP...THE GUSTS HAVE CEASED FOLLOWING THE UNEXPECTED 41 KT GUST
AT 23Z. MOSTLY CLEAR CONDITIONS ARE ANTICIPATED FOR THE REMAINDER
OF THE EVENING...ALTHOUGH THE MVFR CIGS TO THE NORTHWEST ARE A
LITTLE CLOSE TO COMPLETELY IGNORE THE POSSIBILITY OF BRIEF MVFR
CONDITIONS IN THE NEXT COUPLE HOURS. AS MENTIONED IN THE GENERAL
DISCUSSION...CONFIDENCE IS LOW OVERNIGHT FOR THE NEXT ROUND OF
SHRA/TSRA SO KEPT THE TAF AT PROB30. COME THE 03Z AMD...SHOULD
HAVE A BETTER HANDLE ON THE OVERNIGHT FORECAST AND BE ABLE TO
REMOVE COMPLETELY OR REINTRODUCE PREVAILING.
/OUTLOOK FOR KMSP/
SAT...VFR. WINDS WSW AT 5-10KTS.
SUN...VFR. CHANCE SHRA/MVFR CIGS. WINDS NW AT 10-15 KTS.
MON...VFR. WINDS N 5 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...BORGHOFF
SHORT TERM...DWE
LONG TERM...JLT
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
642 PM CDT THU JUL 24 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 233 PM CDT THU JUL 24 2014
SHORT TERM CONCERNS REMAIN COVERAGE OF THUNDER OVERNIGHT INTO
FRIDAY. ALSO...CHANCE OF LARGE HAIL MAINLY LATER TONIGHT INTO SOUTH
CENTRAL MN WITH SOME SEVERE POTENTIAL LINGERING INTO FRIDAY AHEAD OF
FRONT.
UPPER RIDGE IS BEGINNING TO MOVE EAST WITH ONE IMPULSE DROPPING
SOUTHEAST OVER WESTERN MINNESOTA AND THE NEXT WAVE LIFTING INTO
NORTHWEST NODAK AND SOUTHERN MANITOBA. IT APPEARS THE INITIAL WAVE
WILL DROP SOUTHEAST THIS EVENING ALONG THE EASTERN PERIPHERY OF THE
INSTABILITY GRADIENT TO THE WEST AND THE EDGE OF LOW LEVEL WAA/STEEP
MID LEVEL LAPSE RATES. MODELS DIVERGE ON DEVELOPMENT THEREAFTER...
WITH SEVERAL HIRES MODELS INDICATING CANADIAN SYSTEM TAKES OVER AND
DROPS SOUTHEAST OVERNIGHT. STILL SOME POTENTIAL OF LLJ DRIVING
CONVECTION INTO MAINLY SOUTH CENTRAL MN LATE. WILL CARRY HIGHER
POPS TO THE SOUTH ONCE AGAIN...IN SPIRIT WITH THE PREVIOUS
FORECAST. SHOULD SEE SOME QPF MOVE THROUGH THE MOST OF AREA.
FRIDAY STILL SEE SOME POTENTIAL OF ISOLATED/WIDELY SCATTERED
CONVECTION DEVELOPING ALONG THE FRONT AS IT MOVES ACROSS THE EASTERN
PORTION OF THE AREA INTO THE AFTERNOON. WILL HOLD ONTO SOME LOW END
POPS FOR THIS POTENTIAL. INSTABILITY ALONG THE FRONT DOES INCREASE
DURING THE DAY BUT LOW LEVEL CONVERGENCE REMAINS WEAK. MUCH OF THE
HIGH END FORCING IS DRIVEN EAST DURING THE MORNING AS WELL.
TEMPERATURES SHOULD WARM INTO THE MID 80S TO THE SOUTHWEST WITH MIX
WITH THE WEAK FRONT AND UPPER 70S/LOWER 80S ELSEWHERE.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 233 PM CDT THU JUL 24 2014
MAIN CONCERN IN THE EXTENDED PERIOD IS WHETHER SHRA/TSRA DEVELOP
FURTHER SOUTHWARD ACROSS MN THAN EXPECTED FOR LATE SAT AFTN/EARLY
SUNDAY AS A STRONG...AND UNUSUAL UPPER LOW FOR THIS TIME OF YEAR
MOVES EAST-SE ACROSS THE NORTHERN PLAINS...AND INTO THE WESTERN
GREAT LAKES BY SUNDAY. WILL FOLLOW PREVIOUS FORECAST WITH THE MAIN
AREA OF SHRA ACROSS CENTRAL MN/EC MN AND WC WI WHERE BOTH UPPER
LEVEL ENERGY AND HIGHER RH FIELDS ARE EVIDENT. K-INDEX AND 85H
SHOWALTER INDEX FIELDS INDICATED MAINLY SHRA WITH SOME EMBEDDED
TSRA FOR THE TYPICAL DIURNAL TIME FRAME. SUNDAY MORNING/AFTN WILL
LIKELY BE BREEZY AS THE SFC LOW DEEPENS AS IT MOVES SE ACROSS THE
WESTERN GREAT LAKES IN RESPONSE TO THE UPPER JET.
NO CHGS IN THE EXTENDED PERIOD BEYOND THIS WEEKEND WITH BOTH THE
EC/GFS ADVERTISING A STRONG UPPER RIDGE BUILDING OFF THE EAST
COAST OF NORTH AMERICA WITH A DEEPENING LONG WAVE TROUGH ACROSS
THE EASTERN 1/3 OF THE CONUS. THIS WILL KEEP OUR REGION COOLER
THAN NORMAL AND MAINLY DRY. ALTHOUGH COOLER TEMPS ARE
EXPECTED...STANDARD ANOMALIES ARE NOT TOO IMPRESSIVE COMPARED TO
THE DEEP SE U.S. WHERE ANOMALIES COULD DROP TO 2-3 BLW NORMAL.
FOR COMPARISON...OUR REGION WILL BE SLIGHTLY COOLER...BUT STILL
NICE FOR LATE JULY/EARLY AUGUST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 630 PM CDT THU JUL 24 2014
MUCH TO CONSIDER FOR THIS TAF ISSUANCE. DECAYING SHOWERS ACROSS
SOUTHERN MN HAVE PRODUCED STRONG WINDS AS RECENTLY AS 23Z AT MSP
AND STP WHERE GUSTS OF 35 TO 41 KTS WERE REPORTED. GUSTINESS WILL
SUBSIDE THIS EVENING AS THE BOUNDARY LAYER STABILIZES SOMEWHAT.
STRONG MOISTURE TRANSPORT OVER THE EASTERN DAKOTAS HAVE PRODUCED
MID LEVEL CLOUDS OVER WRN MN AT TAF ISSUANCE TIME...AND COULD
FOSTER DEVELOPMENT OF SHRA THIS EVENING. OTHER CIGS...THE MVFR
VARIETY...HAVE ALSO DEVELOPED NORTHWEST OF MSP ALONG I-94. THESE
APPEAR TO BE SOMEWHAT TRANSIENT...SO MADE MENTION OF IT FOR THE
FIRST HOUR IN STC AND AXN TAFS. WILL NEED TO WATCH FOR FURTHER
EXPANSION. OVERNIGHT...MODELS ARE ALL AT ODDS WITH EACH OTHER WITH
THE POTENTIAL NEXT ROUND OF SHRA/TSRA. THE HRRR MODEL SEEMS TO BE
IMPROVING ITS HANDLE ON CURRENT ACTIVITY OVER IA AND ERN MT...AND
IT SHOWS A BAND OF SHRA/TSRA ARRIVING BETWEEN 06-07Z OVER FAR WRN
MN AND HEADING EAST INTO WRN WI BY 09Z OR 10Z. THIS SEEMS LIKE THE
MOST LIKELY SCENARIO AT THIS POINT...BUT SINCE SO MANY OTHER
MODELS ARE SHOWING LITTLE OR NO ACTIVITY OVERNIGHT WAS ONLY
CONFIDENT ENOUGH TO MENTION A PROB30 ATTM.
KMSP...THE GUSTS HAVE CEASED FOLLOWING THE UNEXPECTED 41 KT GUST
AT 23Z. MOSTLY CLEAR CONDITIONS ARE ANTICIPATED FOR THE REMAINDER
OF THE EVENING...ALTHOUGH THE MVFR CIGS TO THE NORTHWEST ARE A
LITTLE CLOSE TO COMPLETELY IGNORE THE POSSIBILITY OF BRIEF MVFR
CONDITIONS IN THE NEXT COUPLE HOURS. AS MENTIONED IN THE GENERAL
DISCUSSION...CONFIDENCE IS LOW OVERNIGHT FOR THE NEXT ROUND OF
SHRA/TSRA SO KEPT THE TAF AT PROB30. COME THE 03Z AMD...SHOULD
HAVE A BETTER HANDLE ON THE OVERNIGHT FORECAST AND BE ABLE TO
REMOVE COMPLETELY OR REINTRODUCE PREVAILING.
/OUTLOOK FOR KMSP/
SAT...VFR. WINDS WSW AT 5-10KTS.
SUN...VFR. CHANCE SHRA/MVFR CIGS. WINDS NW AT 10-15 KTS.
MON...VFR. WINDS N 5 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...JLT
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1206 PM CDT WED JUL 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CDT WED JUL 23 2014
MOST IMPRESSIVE FEATURE ON THE H5 CHART LAST NIGHT WAS THE RIDGE
CENTERED OVER COLORADO...WHERE THE H5 HEIGHT MEASURED AT GRAND
JUNCTION REACHED THE LOFTY HEIGHT OF 6000 M. ITS ASSOCIATED RIDGE
AXIS EXTENDS NORTH INTO SASKATCHEWAN...WITH CONVERGENT NW FLOW NOTED
FROM MANITOBA INTO NW MN...HENCE THE 1028 MB SFC HIGH THAT IS
CENTERED OVER THE MANITOBA LAKES THIS MORNING. DURING THE SHORT
TERM...THE UPPER RIDGE WILL SHIFT EAST INTO THE UPPER MISS VALLEY
WHILE THE SFC HIGH WILL SHIFT OVER TO LAKE MICHIGAN BY 12Z THU.
FOR TODAY...NAM CU RULE SHOWS SCT-BKN CU FIELD DEVELOPING ACROSS WRN
WI...TRAILING OFF TO LITTLE IF ANY CU FOR WRN MN. HOWEVER...WRN MN
WILL HAVE TO DEAL WITH REMNANT CLOUD COVER FROM UPPER WAVES ROTATING
AROUND THE COLORADO RIDGE. IN PARTICULAR...THE RAP SHOWS THE WAVE
CURRENTLY OVER CENTRAL NODAK WORKING TOWARD WRN MN BY THE AFTERNOON.
DRY LOW LEVELS COURTESY THE 1028 MB HIGH WILL MAKE IT TOUGH TO GET
THE PRECIP IN THE MINOT AREA INTO MN...THOUGH A FEW SPRINKLES CAN
NOT BE COMPLETELY RULED OUT. DID BOOST SKY COVER WEST TO ACCOUNT FOR
THIS WAVE AND ITS ASSOCIATED CLOUD COVER THOUGH. H85 TEMPS WILL BE
FAIRLY UNIFORM AROUND 12/13C...WHICH HAS BEEN PRETTY GOOD THIS
SUMMER AT PRODUCING HIGHS IN THE 77 TO 81 DEGREE RANGE...SO NO BIG
CHANGES WERE NEEDED TO THE GOING FORECAST.
TONIGHT...AS THE RIDGE WORKS ACROSS WI...RETURN FLOW WILL BE
STRENGTHENING ACROSS THE DAKOTAS...WITH ISENTROPIC LIFT AND THETA-E
ADVECTION BOTH BLOSSOMING. LLJ ORIENTATION FAVORS ACTIVITY
DEVELOPING ALONG THE MO RIVER TONIGHT...MAKING ABOUT AS FAR EAST AS
SE SODAK...SO KEPT THE FORECAST DRY THROUGH 12Z THU...THOUGH WE
PROBABLY WILL NOT HAVE TO WAIT VERY LONG ON THU TO START SEEING
PRECIP PUSH INTO THE UPPER MN VALLEY. OVER WI...WITH THE HIGH
OVERHEAD THE QUESTION BECOMES HOW LOW TO GO...ALONG WITH THE
POTENTIAL FOR FOG. DID NUDGE LOWS DOWN A DEGREE OR TWO CLOSER TO THE
CONSENSUS RAW MODEL BLEND /BEST PERFORMING GUIDANCE OVER THE LAST
WEEK/...WHICH HAS LADYSMITH DIPPING INTO THE UPPER 40S. THE FOG
POTENTIAL IS A BIT TOUGHER TO PIN DOWN AT THIS POINT...BUT CERTAINLY
IF WE DO SEE LOWS DOWN AROUND 50...SOME PATCHY FOG...ESPECIALLY NEAR
BODIES OF WATER WILL CERTAINLY BE POSSIBLE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 338 AM CDT WED JUL 23 2014
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE OVER
EASTERN DAKOTAS AT DAYBREAK ON THURSDAY ALONG AND AHEAD OF A
STRENGTHENING BAROCLINIC ZONE STRETCHING NW-SE ACROSS THE NORTHERN
PLAINS. THE SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS THE MN
CWA DURING THE DAY AND INTO WESTERN WI BY EVENING AS THE
FRONTOGENETIC ZONE MOVES EAST. THE FA IS IN THE RIGHT ENTRANCE REGION
OF AN 80 PLUS KNOT JET SEGMENT ACROSS THE WESTERN GREAT LAKES
WITH UPPER LEVEL DIVERGENCE INDICATED. BY THE END OF THE DAY...A
COUPLED JET STRUCTURE BEGINS TO DEVELOP...ALONG WITH INCREASING
DIVERGENCE...AS THE LEFT EXIT REGION OF A NEW SEGMENT ARRIVES FROM
THE EASTERN DAKOTAS. THIS FEATURE THEN PASSES ACROSS SOUTHERN
AREAS OF MN AND IA THURSDAY NIGHT. WHILE THIS IS OCCURRING...LOW
LEVEL MOISTURE TRANSPORT IN THE CENTRAL PLAINS VEERS INTO IA AND
SOUTHERN MN. THIS SHOULD RESULT IN THUNDERSTORMS INCREASING IN
COVERAGE ACROSS THE AFOREMENTIONED AREAS ALONG WITH THE POTENTIAL
FOR HEAVY RAIN. THE ECMWF HAS A GREAT HANDLE ON THIS SITUATION
WHILE OTHER DETERMINISTIC MODELS STRUGGLE TO DEVELOP MUCH
PRECIPITATION...WHICH IS A CHARACTERISTIC OF WARM AIR ADVECTION
EVENTS. HENCE...CHANCE POPS DURING THE DAY THURSDAY INCREASE TO
LIKELY THURSDAY NIGHT ACROSS SOUTHERN AREAS OF MN.
THE PRECIPITATION WILL MOVE ESE FRIDAY MORNING WITH A DRYING TREND
FRIDAY AFTERNOON AS A FAIRLY STRONG SHORT WAVE MOVES THROUGH.
HOWEVER...A WEAK SURFACE FRONT WILL SLOWLY TRAVERSE THE FA FRIDAY
AFTERNOON AND NIGHT WITH SOME SMALL POPS REMAINING. MUCH OF
SATURDAY LOOKS DRY BEFORE A COMPACT VERTICALLY STACKED LOW
PRESSURE SYSTEM SWINGS SOUTHEAST ACROSS THE UPPER MISSISSIPPI
VALLEY REGION SATURDAY NIGHT AND SUNDAY. THIS NECESSITATES MORE
CHANCE POPS FOR THE LATTER HALF OF THE WEEKEND. HIGHS FROM
THURSDAY TO SATURDAY WILL BE SLOWLY RISING FROM AROUND 80 TO THE
LOWER AND MIDDLE 80S RESPECTIVELY. HIGHS WILL THEN TREND DOWN INTO
THE MIDDLE TO UPPER 70S FOR SUNDAY AND AT LEAST THE FIRST HALF OF
NEXT WEEK. THE REASON FOR THE EXTENDED COOL DOWN IS A DEEPENING
EASTERN NORTH AMERICA TROUGH WITH A BUILDING RIDGE IN THE WEST.
LONGER RANGE MODEL SOLUTIONS HAVE BEEN VERY CONSISTENT ON THIS
DEVELOPMENT WITH A H5 CLOSED LOW JUST NORTH OF THE GREAT LAKES
NEXT WEDNESDAY. H5 HEIGHTS ACROSS THE GREAT LAKES AND OHIO VALLEY
ARE FORECAST TO BE 2 TO 3 STANDARD DEVIATIONS BELOW NORMAL.
ACCOMPANYING THE COOLER TEMPERATURES WILL BE MAINLY DRY CONDITIONS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1157 AM CDT WED JUL 23 2014
OUTSIDE OF COMMON CLEAR SKIES - LIGHT WIND FOG AT KSTC/KRNH/KEAU
TOMORROW MORNING FOR A A COUPLE HOURS...LOOK FOR VFR CONDITIONS
AND AN OVERALL DRY SET OF TAFS. WE DO EXPECT A BATCH OF SHOWERS
AND WEAK THUNDERSTORMS TO FORM IN THE EASTERN DAKOTAS AND MOVE
INTO WEST CENTRAL AND SOUTHWEST MN TOMORROW MORNING...BUT MOST OF
THE ACTIVITY SHOULD STAY WEST OF THE TAF SITES. THE EXCEPTION
COULD BE KRWF...WHICH APPEARS CLOSE ENOUGH TO GET SOME RAIN. IT
APPEARS THE ACTIVITY WILL REMAIN FARTHER WEST THAN PREVIOUS
THOUGH...BUT LATER SHIFTS WILL MONITOR THE EASTERN EXTEND OF THE
RAIN AND ADD IT TO SITES IF NEEDED. THURSDAY NIGHT LOOKS A LITTLE
BETTER FOR RAIN AT THE REST OF THE MINNESOTA TAF SITES.
KMSP...
NO AVIATION WEATHER CONCERNS IN THE SHORT TERM WITH CLOUDS THAT
HAVE VFR BASES. WE`LL HAVE TO KEEP AN EYE OUT FOR THE THURSDAY
EVENING COMMUTE IF SOME OF THE THUNDERSTORMS THAT ARE LIKELY IN
WESTERN MN START TO TRANSLATE FARTHER EAST THAN EXPECTED.
/OUTLOOK FOR KMSP/
THU NIGHT...VFR. CHANCE MVFR CONDS W/ TSRA OVERNIGHT. WINDS SE AT
10KTS.
FRI...VFR. CHANCE TSRA. WINDS SSE AT 5-10KTS.
SAT...VFR. WINDS W AT 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...CLF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
553 AM CDT WED JUL 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CDT WED JUL 23 2014
MOST IMPRESSIVE FEATURE ON THE H5 CHART LAST NIGHT WAS THE RIDGE
CENTERED OVER COLORADO...WHERE THE H5 HEIGHT MEASURED AT GRAND
JUNCTION REACHED THE LOFTY HEIGHT OF 6000 M. ITS ASSOCIATED RIDGE
AXIS EXTENDS NORTH INTO SASKATCHEWAN...WITH CONVERGENT NW FLOW NOTED
FROM MANITOBA INTO NW MN...HENCE THE 1028 MB SFC HIGH THAT IS
CENTERED OVER THE MANITOBA LAKES THIS MORNING. DURING THE SHORT
TERM...THE UPPER RIDGE WILL SHIFT EAST INTO THE UPPER MISS VALLEY
WHILE THE SFC HIGH WILL SHIFT OVER TO LAKE MICHIGAN BY 12Z THU.
FOR TODAY...NAM CU RULE SHOWS SCT-BKN CU FIELD DEVELOPING ACROSS WRN
WI...TRAILING OFF TO LITTLE IF ANY CU FOR WRN MN. HOWEVER...WRN MN
WILL HAVE TO DEAL WITH REMNANT CLOUD COVER FROM UPPER WAVES ROTATING
AROUND THE COLORADO RIDGE. IN PARTICULAR...THE RAP SHOWS THE WAVE
CURRENTLY OVER CENTRAL NODAK WORKING TOWARD WRN MN BY THE AFTERNOON.
DRY LOW LEVELS COURTESY THE 1028 MB HIGH WILL MAKE IT TOUGH TO GET
THE PRECIP IN THE MINOT AREA INTO MN...THOUGH A FEW SPRINKLES CAN
NOT BE COMPLETELY RULED OUT. DID BOOST SKY COVER WEST TO ACCOUNT FOR
THIS WAVE AND ITS ASSOCIATED CLOUD COVER THOUGH. H85 TEMPS WILL BE
FAIRLY UNIFORM AROUND 12/13C...WHICH HAS BEEN PRETTY GOOD THIS
SUMMER AT PRODUCING HIGHS IN THE 77 TO 81 DEGREE RANGE...SO NO BIG
CHANGES WERE NEEDED TO THE GOING FORECAST.
TONIGHT...AS THE RIDGE WORKS ACROSS WI...RETURN FLOW WILL BE
STRENGTHENING ACROSS THE DAKOTAS...WITH ISENTROPIC LIFT AND THETA-E
ADVECTION BOTH BLOSSOMING. LLJ ORIENTATION FAVORS ACTIVITY
DEVELOPING ALONG THE MO RIVER TONIGHT...MAKING ABOUT AS FAR EAST AS
SE SODAK...SO KEPT THE FORECAST DRY THROUGH 12Z THU...THOUGH WE
PROBABLY WILL NOT HAVE TO WAIT VERY LONG ON THU TO START SEEING
PRECIP PUSH INTO THE UPPER MN VALLEY. OVER WI...WITH THE HIGH
OVERHEAD THE QUESTION BECOMES HOW LOW TO GO...ALONG WITH THE
POTENTIAL FOR FOG. DID NUDGE LOWS DOWN A DEGREE OR TWO CLOSER TO THE
CONSENSUS RAW MODEL BLEND /BEST PERFORMING GUIDANCE OVER THE LAST
WEEK/...WHICH HAS LADYSMITH DIPPING INTO THE UPPER 40S. THE FOG
POTENTIAL IS A BIT TOUGHER TO PIN DOWN AT THIS POINT...BUT CERTAINLY
IF WE DO SEE LOWS DOWN AROUND 50...SOME PATCHY FOG...ESPECIALLY NEAR
BODIES OF WATER WILL CERTAINLY BE POSSIBLE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 338 AM CDT WED JUL 23 2014
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE OVER
EASTERN DAKOTAS AT DAYBREAK ON THURSDAY ALONG AND AHEAD OF A
STRENGTHENING BAROCLINIC ZONE STRETCHING NW-SE ACROSS THE NORTHERN
PLAINS. THE SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS THE MN
CWA DURING THE DAY AND INTO WESTERN WI BY EVENING AS THE
FRONTOGENETIC ZONE MOVES EAST. THE FA IS IN THE RIGHT ENTRANCE REGION
OF AN 80 PLUS KNOT JET SEGMENT ACROSS THE WESTERN GREAT LAKES
WITH UPPER LEVEL DIVERGENCE INDICATED. BY THE END OF THE DAY...A
COUPLED JET STRUCTURE BEGINS TO DEVELOP...ALONG WITH INCREASING
DIVERGENCE...AS THE LEFT EXIT REGION OF A NEW SEGMENT ARRIVES FROM
THE EASTERN DAKOTAS. THIS FEATURE THEN PASSES ACROSS SOUTHERN
AREAS OF MN AND IA THURSDAY NIGHT. WHILE THIS IS OCCURRING...LOW
LEVEL MOISTURE TRANSPORT IN THE CENTRAL PLAINS VEERS INTO IA AND
SOUTHERN MN. THIS SHOULD RESULT IN THUNDERSTORMS INCREASING IN
COVERAGE ACROSS THE AFOREMENTIONED AREAS ALONG WITH THE POTENTIAL
FOR HEAVY RAIN. THE ECMWF HAS A GREAT HANDLE ON THIS SITUATION
WHILE OTHER DETERMINISTIC MODELS STRUGGLE TO DEVELOP MUCH
PRECIPITATION...WHICH IS A CHARACTERISTIC OF WARM AIR ADVECTION
EVENTS. HENCE...CHANCE POPS DURING THE DAY THURSDAY INCREASE TO
LIKELY THURSDAY NIGHT ACROSS SOUTHERN AREAS OF MN.
THE PRECIPITATION WILL MOVE ESE FRIDAY MORNING WITH A DRYING TREND
FRIDAY AFTERNOON AS A FAIRLY STRONG SHORT WAVE MOVES THROUGH.
HOWEVER...A WEAK SURFACE FRONT WILL SLOWLY TRAVERSE THE FA FRIDAY
AFTERNOON AND NIGHT WITH SOME SMALL POPS REMAINING. MUCH OF
SATURDAY LOOKS DRY BEFORE A COMPACT VERTICALLY STACKED LOW
PRESSURE SYSTEM SWINGS SOUTHEAST ACROSS THE UPPER MISSISSIPPI
VALLEY REGION SATURDAY NIGHT AND SUNDAY. THIS NECESSITATES MORE
CHANCE POPS FOR THE LATTER HALF OF THE WEEKEND. HIGHS FROM
THURSDAY TO SATURDAY WILL BE SLOWLY RISING FROM AROUND 80 TO THE
LOWER AND MIDDLE 80S RESPECTIVELY. HIGHS WILL THEN TREND DOWN INTO
THE MIDDLE TO UPPER 70S FOR SUNDAY AND AT LEAST THE FIRST HALF OF
NEXT WEEK. THE REASON FOR THE EXTENDED COOL DOWN IS A DEEPENING
EASTERN NORTH AMERICA TROUGH WITH A BUILDING RIDGE IN THE WEST.
LONGER RANGE MODEL SOLUTIONS HAVE BEEN VERY CONSISTENT ON THIS
DEVELOPMENT WITH A H5 CLOSED LOW JUST NORTH OF THE GREAT LAKES
NEXT WEDNESDAY. H5 HEIGHTS ACROSS THE GREAT LAKES AND OHIO VALLEY
ARE FORECAST TO BE 2 TO 3 STANDARD DEVIATIONS BELOW NORMAL.
ACCOMPANYING THE COOLER TEMPERATURES WILL BE MAINLY DRY CONDITIONS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 548 AM CDT WED JUL 23 2014
HIGH PRESSURE WILL MOVE ACROSS MN AND INTO WI THIS
PERIOD...RESULTING IN QUIET CONDITIONS WITH LIGHT WINDS. VFR
CONDITIONS WILL DOMINATE...WITH THE ONLY EXCEPTION BEING THE
POTENTIAL FOR FOG THIS MORNING AND ESPECIALLY THURSDAY MORNING OVER
IN EAU...WHEN THE CENTER OF THE HIGH WILL BE NEAR CENTRAL WI. THIS
WILL MAINLY BE A RIVER VALLEY FOG THOUGH...HENCE THE PREVAILING MVFR
WITH A TEMPORARY LIFR VIS THU MORNING. OTHER THAN THAT...CU FIELD
WILL DEVELOP OVER ERN MN/WRN WI LATE THIS MORNING...STARTING OUT
NEAR 4K FEET...BUT CLIMBING TO NEAR 6K FEET BY THE LATE AFTERNOON.
OUT WEST...MID LEVEL CLOUDS OUT IN THE DAKOTAS WILL SPILL INTO WRN
MN BY THE AFTERNOON...BUT EXPECTING NOTHING MORE THAN THAT FROM THE
NODAK DISTURBANCE.
KMSP...HIGH CONFIDENCE TAF WITH VFR CONDITIONS PREVAILING WITH LIGHT
NORTH WINDS TODAY...CALM WINDS TONIGHT...FOLLOWED BY LIGHT SE WINDS
THURSDAY.
/OUTLOOK FOR KMSP/
THU...VFR. CHANCE MVFR CONDS W/ TSRA LATE AFTERNOON AND
OVERNIGHT. WINDS SE AT 10KTS.
FRI...VFR. CHANCE TSRA. WINDS SSE AT 5-10KTS.
SAT...VFR. WINDS W AT 10KTS.
KMSP...
/OUTLOOK FOR KMSP/
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
338 AM CDT WED JUL 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CDT WED JUL 23 2014
MOST IMPRESSIVE FEATURE ON THE H5 CHART LAST NIGHT WAS THE RIDGE
CENTERED OVER COLORADO...WHERE THE H5 HEIGHT MEASURED AT GRAND
JUNCTION REACHED THE LOFTY HEIGHT OF 6000 M. ITS ASSOCIATED RIDGE
AXIS EXTENDS NORTH INTO SASKATCHEWAN...WITH CONVERGENT NW FLOW NOTED
FROM MANITOBA INTO NW MN...HENCE THE 1028 MB SFC HIGH THAT IS
CENTERED OVER THE MANITOBA LAKES THIS MORNING. DURING THE SHORT
TERM...THE UPPER RIDGE WILL SHIFT EAST INTO THE UPPER MISS VALLEY
WHILE THE SFC HIGH WILL SHIFT OVER TO LAKE MICHIGAN BY 12Z THU.
FOR TODAY...NAM CU RULE SHOWS SCT-BKN CU FIELD DEVELOPING ACROSS WRN
WI...TRAILING OFF TO LITTLE IF ANY CU FOR WRN MN. HOWEVER...WRN MN
WILL HAVE TO DEAL WITH REMNANT CLOUD COVER FROM UPPER WAVES ROTATING
AROUND THE COLORADO RIDGE. IN PARTICULAR...THE RAP SHOWS THE WAVE
CURRENTLY OVER CENTRAL NODAK WORKING TOWARD WRN MN BY THE AFTERNOON.
DRY LOW LEVELS COURTESY THE 1028 MB HIGH WILL MAKE IT TOUGH TO GET
THE PRECIP IN THE MINOT AREA INTO MN...THOUGH A FEW SPRINKLES CAN
NOT BE COMPLETELY RULED OUT. DID BOOST SKY COVER WEST TO ACCOUNT FOR
THIS WAVE AND ITS ASSOCIATED CLOUD COVER THOUGH. H85 TEMPS WILL BE
FAIRLY UNIFORM AROUND 12/13C...WHICH HAS BEEN PRETTY GOOD THIS
SUMMER AT PRODUCING HIGHS IN THE 77 TO 81 DEGREE RANGE...SO NO BIG
CHANGES WERE NEEDED TO THE GOING FORECAST.
TONIGHT...AS THE RIDGE WORKS ACROSS WI...RETURN FLOW WILL BE
STRENGTHENING ACROSS THE DAKOTAS...WITH ISENTROPIC LIFT AND THETA-E
ADVECTION BOTH BLOSSOMING. LLJ ORIENTATION FAVORS ACTIVITY
DEVELOPING ALONG THE MO RIVER TONIGHT...MAKING ABOUT AS FAR EAST AS
SE SODAK...SO KEPT THE FORECAST DRY THROUGH 12Z THU...THOUGH WE
PROBABLY WILL NOT HAVE TO WAIT VERY LONG ON THU TO START SEEING
PRECIP PUSH INTO THE UPPER MN VALLEY. OVER WI...WITH THE HIGH
OVERHEAD THE QUESTION BECOMES HOW LOW TO GO...ALONG WITH THE
POTENTIAL FOR FOG. DID NUDGE LOWS DOWN A DEGREE OR TWO CLOSER TO THE
CONSENSUS RAW MODEL BLEND /BEST PERFORMING GUIDANCE OVER THE LAST
WEEK/...WHICH HAS LADYSMITH DIPPING INTO THE UPPER 40S. THE FOG
POTENTIAL IS A BIT TOUGHER TO PIN DOWN AT THIS POINT...BUT CERTAINLY
IF WE DO SEE LOWS DOWN AROUND 50...SOME PATCHY FOG...ESPECIALLY NEAR
BODIES OF WATER WILL CERTAINLY BE POSSIBLE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 338 AM CDT WED JUL 23 2014
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE OVER
EASTERN DAKOTAS AT DAYBREAK ON THURSDAY ALONG AND AHEAD OF A
STRENGTHENING BAROCLINIC ZONE STRETCHING NW-SE ACROSS THE NORTHERN
PLAINS. THE SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS THE MN
CWA DURING THE DAY AND INTO WESTERN WI BY EVENING AS THE
FRONTOGENETIC ZONE MOVES EAST. THE FA IS IN THE RIGHT ENTRANCE REGION
OF AN 80 PLUS KNOT JET SEGMENT ACROSS THE WESTERN GREAT LAKES
WITH UPPER LEVEL DIVERGENCE INDICATED. BY THE END OF THE DAY...A
COUPLED JET STRUCTURE BEGINS TO DEVELOP...ALONG WITH INCREASING
DIVERGENCE...AS THE LEFT EXIT REGION OF A NEW SEGMENT ARRIVES FROM
THE EASTERN DAKOTAS. THIS FEATURE THEN PASSES ACROSS SOUTHERN
AREAS OF MN AND IA THURSDAY NIGHT. WHILE THIS IS OCCURRING...LOW
LEVEL MOISTURE TRANSPORT IN THE CENTRAL PLAINS VEERS INTO IA AND
SOUTHERN MN. THIS SHOULD RESULT IN THUNDERSTORMS INCREASING IN
COVERAGE ACROSS THE AFOREMENTIONED AREAS ALONG WITH THE POTENTIAL
FOR HEAVY RAIN. THE ECMWF HAS A GREAT HANDLE ON THIS SITUATION
WHILE OTHER DETERMINISTIC MODELS STRUGGLE TO DEVELOP MUCH
PRECIPITATION...WHICH IS A CHARACTERISTIC OF WARM AIR ADVECTION
EVENTS. HENCE...CHANCE POPS DURING THE DAY THURSDAY INCREASE TO
LIKELY THURSDAY NIGHT ACROSS SOUTHERN AREAS OF MN.
THE PRECIPITATION WILL MOVE ESE FRIDAY MORNING WITH A DRYING TREND
FRIDAY AFTERNOON AS A FAIRLY STRONG SHORT WAVE MOVES THROUGH.
HOWEVER...A WEAK SURFACE FRONT WILL SLOWLY TRAVERSE THE FA FRIDAY
AFTERNOON AND NIGHT WITH SOME SMALL POPS REMAINING. MUCH OF
SATURDAY LOOKS DRY BEFORE A COMPACT VERTICALLY STACKED LOW
PRESSURE SYSTEM SWINGS SOUTHEAST ACROSS THE UPPER MISSISSIPPI
VALLEY REGION SATURDAY NIGHT AND SUNDAY. THIS NECESSITATES MORE
CHANCE POPS FOR THE LATTER HALF OF THE WEEKEND. HIGHS FROM
THURSDAY TO SATURDAY WILL BE SLOWLY RISING FROM AROUND 80 TO THE
LOWER AND MIDDLE 80S RESPECTIVELY. HIGHS WILL THEN TREND DOWN INTO
THE MIDDLE TO UPPER 70S FOR SUNDAY AND AT LEAST THE FIRST HALF OF
NEXT WEEK. THE REASON FOR THE EXTENDED COOL DOWN IS A DEEPENING
EASTERN NORTH AMERICA TROUGH WITH A BUILDING RIDGE IN THE WEST.
LONGER RANGE MODEL SOLUTIONS HAVE BEEN VERY CONSISTENT ON THIS
DEVELOPMENT WITH A H5 CLOSED LOW JUST NORTH OF THE GREAT LAKES
NEXT WEDNESDAY. H5 HEIGHTS ACROSS THE GREAT LAKES AND OHIO VALLEY
ARE FORECAST TO BE 2 TO 3 STANDARD DEVIATIONS BELOW NORMAL.
ACCOMPANYING THE COOLER TEMPERATURES WILL BE MAINLY DRY CONDITIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1041 PM CDT TUE JUL 22 2014
VFR CONDS XPCTD AT ALL SITES WITH NO IMPACTS. N WINDS AOB 10 KT
XPCTD THROUGHOUT THE DURATION OF THE 06Z TAFS. SKC CONDS
OVERNIGHT FOLLOWED BY A RETURN OF SCT MIDLVL CU CLOUDS BY MIDDAY
TMRW.
KMSP...NO SIGNIFICANT IMPACTS XPCTD THROUGHOUT THIS TAF SET
DURATION.
/OUTLOOK FOR KMSP/
THU...VFR. WINDS SE AT 10KTS.
THU NGT...VFR. MVFR CONDITIONS/TSRA POSSIBLE. WINDS SE 10 KNOTS.
FRI...VFR. MVFR CONDITIONS TSRA. WINDS SSE AT 10-15KTS.
FRI NGT...VFR. MVFR CONDITIONS IN SCT TSRA. WINDS S/SE AT 5-8KTS.
SAT...VFR. WINDS W/NW AT 10-15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1224 AM CDT Wed Jul 23 2014
.DISCUSSION...
Issued at 333 PM CDT TUE JUL 22 2014
Mid to upper 90s prevailing across much of the region this afternoon
as the warmest airmass of the season continues to grip the area.
Latest 850-mb analysis from the SPC meso site showing the 28C temp
contour directly over the fcst region this afternoon. This combined
with steep low-level lapse rates and dewpoints largely in the lower
to middle 70s has resulted in a very hot and oppressive day across
the area. Current heat advisory for the entire fcst area needs no
adjustments and is set to expire at 7 PM this evening.
In addition to the heat...the other main concern remains focused on
possible severe convection later this evening as main cold front now
found over southwestern IA and eastern NE continues to slowly track
south with time. For what its worth...high-res convection allowing
models struggled mightily with this mornings convection across
our northeastern zones...and very little guidance from these models
appears to be in the offering for activity later this evening as
well. Not surprisingly...overall confidence for tonight/s fcst is
less than desired as some models show developing convection...while
others such as the HRRR continue to backtrack towards a drier and
drier fcst with each successive run. So here/s what we know so far...
Sfc boundary set to arrive towards the IA/MO state line around 00z
this evening. Out ahead of this feature...airmass remains capped with
a significant amount of inhibition thanks that 700-mb temps ranging
in the 12-14C range. Additionally...northerly 925-850-mb winds will
provide little if any low-level convergence into the arriving
frontal boundary as we continue into the evening hrs. Despite
this...quick look at latest water vapor imagery does show an inbound
shortwave trough now seen over south-central NE and north-central
KS. This feature combined with very modest frontal convergence may be
enough to get this going...however concerns for widespread severe
remain marginal as of this writing. Latest SPC day 1 outlook has
trimmed the SLGT risk mention further to the southeast...which is
more in line with where convection may develop as front continues to
drop south. That said...main severe threat with any activity that
forms will likely be strong wind gusts as nearly dry adiabatic lapse
rates will support favorable low-level and boundary layer mixing.
High wet-bulb zero heights (>16 kft) will likely negate the threat
for very large hail until later on when any lingering activity begins
to go elevated with due to loss of daytime heating. Overall concerns
for hail though remain the lowest of the two forms of severe outlined
above however. In general...severe threat this evening looks to be
isolated with the most likely areas to possibly see a rogue storm or
two residing in our northeastern zones where better potential exists
to break the cap thanks to slightly cooler temps aloft. If activity gets
going...severe threat should transition south of the I-70 corridor as
front continues to make progress through the area. As mentioned above
through...a widespread severe event does not look to be in the
offering this evening.
Region should largely reside in a post frontal airmass
tomorrow...with weak dry air advection allowing for cooler and less
humid conditions. In fact...fcst models suggest dewpoints anywhere
between 5-10 degrees cooler than today...which should be a welcomed
relief following today/s oppressive conditions. High temps should
round out in the middle to upper 80s.
Large scale pattern shift expected from Thursday into Friday as southern
Plains ridge retrograde west as northern stream energy traverses the
northern Rockies/Plains. As this occurs...upper flow will become
decidedly more northwesterly which will set the stage for unsettled
conditions heading into the upcoming weekend. Closer to the
surface...fcst models still paint a northward retreating warm front
by late week as return flow reestablishes itself across the Great
Plains in advance of lee side troughing along the Front Range. Several
upper shortwaves embedded in northwest flow will allow for continued
chances for showers and storms through at least Saturday...if not
Sunday. As is the case with convection this time of year...hard to
pin your hat on any one feature of interest as long range models to
include both the ECMWF and GFS normally suffer from convective
feedback issues to some degree. As a result...have maintained Chc
pops through the weekend before high pressure arrives by early next
week following the passage of a cold front on Sunday. Temps early
next week look to fall below normal with highs possibly only reaching
into the lower to middle 80s come Monday and Tuesday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday Night)
Issued at 1224 AM CDT WED JUL 23 2014
VFR conds will cont thru the TAF period. A few-sct clouds around
3-4kft will affect the terminals thru the first couple hours of the
TAF period otherwise expect just few-sct high cirrus clouds. Winds
will be out of the NNE around 10kts through this evening before
veering to the ENE and diminishing to btn 5-10kts.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...32
AVIATION...73
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1158 PM CDT Tue Jul 22 2014
.SHORT TERM: (Through Late Tonight)
Issued at 330 PM CDT Tue Jul 22 2014
There is a considerable amount of uncertainty in the convective
evolution and coverage tonight. Dew points in the 70s, strong
heating and steep mid level lapse rates are currently contributing
to SBCAPE of 3500-6000 j/kg across the northwest 2/3rds of the CWA
with the highest values across central and north central MO. There
also is a significant cap in place due to warm mid level temperatures.
The big question is when and how much of the cap will be reduced
as the front moves southward out of Iowa and southeast Nebraska
into northern MO this evening. Model solutions including the
convection allowing models are quite varied on QPF and implied
coverage. Recent runs of the HRRR are quite stingy on coverage
with isolated storms at best. I don`t have a great feel for what
is going to occur, but the deterministic models suggest that height
falls/cooling aloft should be sufficient to weaken the cap and
allow for scattered development along front, mainly late this
evening and especially overnight. I have attempted to follow this
trend with the greatest coverage along/east of the MS river. The
severe threat is conditional on development early enough this
evening to realize the big CAPE, and the main threat would appear
to be damaging winds given the warm air aloft.
Glass
.LONG TERM: (Wednesday through Next Tuesday)
Issued at 330 PM CDT Tue Jul 22 2014
The cold front should lie roughly from south central IL to near
St. Louis into southwest MO at 12z and exit the CWA by early
afternoon. There will continue to be a threat of scattered showers
and storms ahead of the advancing front. Temperatures should be
cooler tomorrow with the main thrust of cooling and drying in the
afternoon. Unseasonably deep upper troffing in the eastern U.S.
will keep a large surface high dominating the area Wednesday night
into Friday, with most of this period dominated by lower humidity
and below average temperatures.
Beginning late Thursday night and into Friday the threat of precipitation
will return in association with elevated showers/thunderstorms due to
strong warm advection/moisture transport via a southwesterly LLJ ahead
of the slowly retreating warm front and in association with impulses
aloft dropping southeastward along the eastern periphery of the
upper high. A cold front will then drop through the area Saturday
afternoon-Sunday as a upper trof digs southeastward from the upper
MS valley and into the Great Lakes bringing another threat of
showers and thunderstorms. This upper wave will be part of large
scale amplification of the upper air pattern across NOAM and will
feature another deep trof over the eastern U.S. through the first
part of next week and send out July with another period of below
average temperatures.
Glass
&&
.AVIATION: (For the 06z TAFs through 06z Wednesday Night)
Issued at 1147 PM CDT Tue Jul 22 2014
TSTMs have struggled to maintain vs a strong cap this evening.
don`t expect much to change overnight with isld activity
continuing thru the night. Removed prevailing thunder group
completely from KCOU and KUIN and changed to VCTS at STL metro
sites at a later time. Band of CIGS near 2.5kft has dvlpd just
behind the front...as indicated by the models...across nthrn MO
and on into cntrl/nthrn IL. Expect this to follow the front south
overnight and possibly expand some. MVFR fog is also possible
towards mrng with a moist bndry lyr in place. Otherwise...expect
diurnal cu and N/NNE winds aob 12kts.
Specifics for KSTL:
Coverage for TSTMs has been minimal this evng as the convection
struggles to survive against a strong cap...so have a VCTS group
to cover the threat. A band of post frontal high end MVFR CIGs
has dvlpd across nthrn IL and cntrl IL. This should push S in
concert with the front. Otherwise...expect diurnal cu and a N/NNE
wind aob 12kts.
2%
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
621 PM CDT THU JUL 24 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 332 PM CDT THU JUL 24 2014
FAIRLY QUIET DAY WITH MOSTLY SUNNY SKIES AS THE UPPER LEVEL RIDGE
AXIS CONTINUES TO MOVE OVERHEAD. 12Z SUBJECTIVE UPPER AIR ANALYSIS
IN ADDITION TO RAP ANALYSIS SHOWS A STOUT MID LEVEL WARM POCKET OVER
THE HIGH PLAINS REGION. THIS CONTINUES TO DRIFT EWD WHICH WOULD
TYPICALLY CAP OFF ANY POTENTIAL THUNDERSTORM DEVELOPMENT. THIS BEING
SAID...AN AREA OF CONVECTION HAS MANAGED TO DEVELOP OVER THE
NEBRASKA PANHANDLE AND PORTIONS OF NORTHEAST COLORADO IN ADVANCE OF
A WEAK VORT MAX. LATEST RUNS OF THE HRRR AND RAP INDICATE THIS
CONVECTION HOLDING ON AND SPREADING EAST THROUGHOUT THE LATER
EVENING HOURS. AS A RESULT...WILL HOLD ONTO SMALL POPS ACROSS THE
NORTHERN CWA.
ATTENTION THEN TURNS TO HEAT TOMORROW. HIGHS SHOULD REACH THE 100
DEGREE MARK ACROSS THE KANSAS COUNTIES WITH UPPER 90S SOUTH OF
INTERSTATE 80. COMBINED WITH SFC DEWPOINTS IN THE UPPER 60S...WE
SHOULD APPROACH HEAT INDICES IN THE 105+ RANGE. AS A RESULT...WILL
GO AHEAD AND ISSUE A HEAT ADVISORY FOR PORTIONS OF SOUTH CENTRAL
NEBRASKA AND ALL THE NORTH CENTRAL KANSAS COUNTIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 332 PM CDT THU JUL 24 2014
ANOTHER HOT DAY IS EXPECTED ON SATURDAY WITH POTENTIAL FOR HEAT
ADVISORY CRITERIA AGAIN. WILL LET LATER SHIFTS EVALUATE FOR
ADDITIONAL HEADLINES. A COLD FRONT WILL DROP OVER THE AREA SATURDAY
NIGHT WITH HIGH PRESSURE BUILDING ACROSS THE AREA SUNDAY INTO
MONDAY. MUCH COOLER AND DRIER AIRMASS WILL ALLOW TEMPS TO DROP INTO
THE LOW 80S FOR HIGHS AND LOW 60S FOR LOWS.
RETURN FLOW WILL SET UP EARLY NEXT WEEK WHILE A SERIES OF UPPER
LEVEL SHORTWAVES ARE FORECAST TO PASS THROUGH THE REGION IN
MID/UPPER LEVEL NORTHWESTERLY FLOW. MODEL CONSENSUS HAS PUT AT LEAST
A SLIGHT CHANCE OR CHANCE OF TSTMS FROM MONDAY NIGHT THROUGH
THURSDAY. ALTHOUGH WIDESPREAD CONTINUOUS PCPN IS NOT
ANTICIPATED...WILL LEAVE THESE CHANCES IN DUE TO UNCERTAINTY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 618 PM CDT THU JUL 24 2014
EXPECT VFR CONDITIONS THROUGH THE PERIOD. THERE ARE A FEW TSTMS IN
WESTERN NEB BUT CHANCE OF THEM MAKING IT INTO THE TERMINAL AREA
ARE LESS THAN 30 PERCENT. ONLY OTHER CONCERN IS A WIND SHIFT WHICH
SHOULD OCCUR BETWEEN 14-15Z IN THE EAR AND GRI AREAS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM NOON TO 7 PM CDT FRIDAY FOR NEZ063-064-
074>077-083>087.
KS...HEAT ADVISORY FROM NOON TO 7 PM CDT FRIDAY FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...EWALD
AREA FORECAST DISCUSSION
NWS BUFFALO NY
224 AM EDT WED JUL 23 2014
.SYNOPSIS...
AS A COLD FRONT WILL CROSS MUCH OF THE CWA THIS MORNING AND BE SOUTH
AND EAST OF MUCH OF THE AREA BY LATER THIS AFTERNOON. THE HUMID AIR
WILL KEEP THE WARM AND MUGGY CONDITIONS IN PLACE ACROSS THE AREA FOR
THE REMAINDER OF THE OVERNIGHT. THEN EXPECT A ROUND SHOWERS AND
SCATTERED THUNDERSTORMS AS THE COLD FRONT CROSSES THE REGION FROM
NORTHWEST TO SOUTHEAST WEDNESDAY. COOLER AND DRYER WEATHER WILL
FOLLOW THIS COLD FRONT. EXPECT COMFORTABLE CONDITIONS WITH TEMPS
AVERAGING A BIT BELOW NORMAL THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
SURFACE HIGH PRESSURE CENTERED OFF THE MID ATLANTIC COAST AND LOW
PRESSURE PASSING NORTH OF THE GREAT LAKES WILL MAINTAIN A WARM
AND HUMID SSW BREEZE ACROSS THE REGION OVERNIGHT. THIS WILL KEEP IT
FEEL RATHER MUGGY...WITH LOWS IN THE UPPER 60S TO LOWER 70S.
A LINE OF CONVECTION HAS CONSOLIDATED NICELY ACROSS SOUTHWESTERN
ONTARIO...STRETCHING ROUGHLY FROM TORONTO SOUTHWESTWARD ALONG THE
NORTHERN SHORELINE OF WESTERN LAKE ERIE. LINE IS PROGRESSING
EASTWARD AT A PRETTY SLOW PACE...SO DID NOT MAKE ANY CHANGES TO POPS
AT THIS TIME. IF THIS LINE HOLDS TOGETHER MAY SEE A SHOWER OR
THUNDERSTORM ACROSS THE NIAGARA FRONTIER BY DAWN OR A LITTLE
THEREAFTER.
THE HRRR ALONG WITH THE NAM12/RGEM APPEAR TO SHOW A REASONABLE
PROGRESSION FOR THIS LINE...WITH MOST OF THE RAINFALL WILL HAVE
CROSSED THE FORECAST AREA BEFORE NOONTIME...FOLLOWED SHORTLY
THEREAFTER BY THE COLD FRONT. HEAVIEST RAINS SHOULD FALL MID TO LATE
MORNING...PROBABLY NORTHEAST OF THE LAKES WHERE A MOIST PRE-
FRONTAL SW FLOW WILL CLASH WITH THE NW WINDS BEHIND THE FRONT. HIGH
DEWPOINTS AND 8KFT TO 10KFT DEPTH OF MOISTURE WILL YIELD
PRECIPITABLE WATER VALUES RANGING FROM 1.6 TO 1.8 INCH AND THE
GREATEST OMEGA IS WITHIN THE LOWER MOIST LAYER...INDICATING
EXCLUSIVE WARM RAIN PROCESS AND THE POTENTIAL FOR SOME DOWNPOURS.
THE COLD FRONT CROSSES THE REGION DURING THE EARLY AFTERNOON WITH
MUCH DRIER AIR BY THE END OF THE DAY.
HIGH TEMPS MAY RECOVER A COUPLE OF DEGREES IN THE MORNING WITH
READINGS IN THE MID TO UPPER 70S.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
THE COLD FRONT WILL BE PUSHING TO THE EAST COAST WEDNESDAY EVENING
WITH THE LAST FEW LINGERING SHOWERS ACROSS CENTRAL NEW YORK
TAPERING OFF BEFORE MIDNIGHT. A COOLER AND DRIER AIRMASS WILL BUILD
IN BEHIND THE FRONT THROUGH THE END OF THE WEEK. LINGERING MOISTURE
FROM RAIN EARLIER WEDNESDAY MAY BRING SOME PATCHY FOG LATER
WEDNESDAY NIGHT MAINLY ACROSS THE SOUTHERN TIER AND NORTH COUNTY
OTHERWISE TEMPS WILL FALL INTO THE 50S EXCEPT ALONG THE LAKESHORES
AND IN URBAN AREAS.
THURSDAY THROUGH FRIDAY HIGH PRESSURE WILL SHIFT ACROSS NEW YORK
BRINGING VERY COMFORTABLE TEMPERATURES AND HUMIDITY A FEW DEGREES
BELOW AVERAGE. (HIGHS IN THE 70S AND LOWS IN THE 50S) DIURNAL
CUMULUS WILL SPROUT UP THURSDAY AS OVERNIGHT MOISTURE MIXES OUT
ALONG WITH A LIGHT NORTHERLY BREEZE. THURSDAY NIGHT MAINLY CLEAR SKIES
AND LIGHT WINDS WILL BRING RIVER VALLEY FOG ACROSS THE SOUTHERN TIER
OTHERWISE MAINLY CLEAR SKIES. ON FRIDAY MORE IN THE WAY OF DRYING
WILL KEEP MAINLY SUNNY SKIES WITH SOME HIGH CIRRUS WORKING IN FROM
THE WEST AHEAD OF A CENTRAL GREAT LAKES SYSTEM. OVERALL VERY
PLEASANT WEATHER TO CLOSE OUT THE WEEK.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
OVER THE WEEKEND INTO THE START OF NEXT WEEK AN AMPLIFYING EAST
COAST 500MB TROUGH FORECASTED BY THE MEDIUM RANGE MODELS WILL BRING
BACK A THREAT OF SOME SHOWERS AND THUNDERSTORMS WHILE KEEPING
TEMPERATURES NEAR TO A FEW DEGREES BELOW AVERAGE. QUITE A BIT OF
UNCERTAINTY IS PRESENT FOR SATURDAYS FORECAST WITH MODELS NOT IN
ALIGNMENT ON THE INITIAL UPPER LOW DROPPING ACROSS THE GREAT LAKES.
THE 12Z GFS IS FASTEST BRINGING IN SHOWERS BY SATURDAY AFTERNOON
WHILE OTHER MODELS DELAY THIS. HAVE INTRODUCED A SLIGHT CHANCE OF
SHOWERS ON SATURDAY ACROSS WNY BUT OVER ALL FEEL THE DAY WILL END UP
BEING DRY.
BETTER AGREEMENT DEVELOPS BY SUNDAY INTO MONDAY WHERE MODELS SHIFT
SEVERAL SHORTWAVES THROUGH THE UPPER TROUGH WITH EACH OF THESE
BRINGING A THREAT FOR SHOWERS AND THUNDERSTORMS. HAVE FEATURED THE
HIGHEST POPS ON MONDAY WHERE THE BEST MODEL ALIGNMENT IS FOUND IN
THE 500MB PATTERN WITH THE TROUGH CENTERED ACROSS THE GREAT LAKES.
TUESDAY THE CENTER OF THE TROUGH LOOKS TO BE OVER NEW YORK WITH A
CHANCE OF DIURNAL INSTABILITY SHOWERS. THIS UPPER TROUGH WILL KEEP
HIGH TEMPS LIMITED TO THE LOW TO MID 70S NEXT WEEK WHERE WE
TYPICALLY WOULD EXPECT NEAR 80.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
EXPECT MAINLY VFR CONDITIONS OVERNIGHT...WITH INCREASING CLOUDS
AHEAD OF A FRONTAL BOUNDARY. THERE MAY BE A FEW SHOWERS OR TSTMS
NEAR BUF/IAG TOWARD DAYBREAK...WITH WIDESPREAD SHOWERS AND
THUNDERSTORMS LIKELY TO HOLD OFF UNTIL THE MORNING HOURS WEDNESDAY.
THIS MAY RESULT IN LOCALIZED CONDITIONS OF LOWER CEILINGS AND LOCALLY
HEAVY DOWNPOURS...HOWEVER THE MAJORITY OF THE MORNING IS LIKELY TO
REMAIN VFR. AFTER THIS...MVFR CIGS ARE LIKELY TO BUILD BEHIND THE
FRONT WEDNESDAY AFTERNOON AND EVENING IN THE NW FLOW. SOME OF THE
LATEST GUIDANCE IS SUGGESTING THAT MOISTURE IN THE LOWER AND MID
LEVELS MAY REMAIN HIGH INTO TONIGHT BEHIND THE COLD FRONT. WILL TAKE
A CLOSER LOOK AT THIS AND ADJUST CLOUD COVER AND CEILINGS
ACCORDINGLY IF NEEDED.
OUTLOOK...
WEDNESDAY NIGHT...MAINLY VFR...PATCHY IFR/MVFR CIGS AND FOG POSSIBLE.
THURSDAY...VFR.
THURSDAY NIGHT THROUGH SATURDAY...MAINLY VFR...SAVE FOR IFR/MVFR
IN PATCHY SOUTHERN TIER VALLEY FOG LATER EACH NIGHT/EARLY EACH
MORNING.
SUNDAY...VFR/MVFR SCATTERED SHOWERS.
&&
.MARINE...
AREA OF HIGH PRESSURE WILL CONTINUE TO SLIP EASTWARD AND ALLOW FOR A
COLD FRONT TO CROSS THE LAKES ON WEDNESDAY. WINDS WILL INCREASE IN
SPEED AHEAD OF THE COLD FRONT THROUGH THE REMAINDER OF THE
OVERNIGHT...AND BECOME SSW. CONDITIONS MAY BRIEFLY APPROACH SMALL
CRAFT CRITERIA ON LAKE ERIE VERY LATE TONIGHT INTO WEDNESDAY MORNING
IN THIS FLOW. BEHIND THE COLD FRONT...WAVES 2 TO 3 FEET WILL BE
POSSIBLE ON BOTH LAKES WEDNESDAY NIGHT AND INTO THURSDAY. WINDS WILL
LESSEN THURSDAY AFTERNOON AND WAVES WILL DIMINISH ACCORDINGLY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JM
NEAR TERM...APFFEL/JM/WCH
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...APFFEL/JM
MARINE...APFFEL/JM/WCH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1019 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 1018 PM CDT THU JUL 24 2014
SEVERE THUNDERSTORM WATCH 439 WAS ALLOWED TO EXPIRE AT 03 UTC AS
STORMS WILL BE PROPAGATING INTO A LESS FAVORABLE ENVIRONMENT ACROSS
CENTRAL NORTH DAKOTA. STRONG WINDS BEHIND THE LINE OF
THUNDERSTORMS ACROSS WESTERN NORTH DAKOTA HAVE STEADILY DECREASED
WITH SUNSET. WIND GUSTS ARE EXPECTED TO REMAIN BELOW 40 MPH...AND
THE HIGH WIND WARNING AND WIND ADVISORY THAT WERE IN EFFECT HAVE
BEEN CANCELLED.
UPDATE ISSUED AT 851 PM CDT THU JUL 24 2014
ISSUED A WIND ADVISORY FOR STRONG WINDS BEHIND THE OCCLUDING FRONT
ACROSS SOUTHWEST NORTH DAKOTA THROUGH 06 UTC.
UPDATE ISSUED AT 812 PM CDT THU JUL 24 2014
VERY STRONG WESTERLY WINDS WITH GUSTS IN EXCESS OF 50KTS HAVE BEEN
WIDESPREAD BEHIND THE LINE OF CONVECTION AND OCCLUDING FRONT
ACROSS NORTHEAST MONTANA. THIS IS EXPECTED TO CONTINUE INTO MUCH
OF WESTERN NORTH DAKOTA BEHIND THE LINE OF STORMS. THUS...A HIGH
WIND WARNING HAS BEEN ISSUED THROUGH 06 UTC FOR MUCH OF THE WEST.
UPDATE ISSUED AT 655 PM CDT THU JUL 24 2014
PER COORDINATION WITH SPC...SEVERE THUNDERSTORM WATCH 439 HAS BEEN
EXPANDED TO INCLUDE THE SOUTHWEST COUNTIES OF GOLDEN
VALLEY...BILLINGS...STARK...SLOPE...BOWMAN...HETTINGER AND ADAMS
COUNTIES UNTIL 03 UTC.
UPDATE ISSUED AT 540 PM CDT THU JUL 24 2014
THE 20 UTC AND INCOMING 21 UTC HRRR ITERATIONS HAVE A GOOD HANDLE
ON THE CURRENT CONVECTION ACROSS EASTERN MONTANA...AND WILL LEAN
HEAVILY ON THEIR SOLUTIONS FOR THE REMAINDER OF THE EVENING AND
OVERNIGHT. DID COORDINATE WITH SPC AT 2230 UTC REGARDING A
POTENTIAL EXPANSION OF SEVERE THUNDERSTORM WATCH 439 INTO
SOUTHWEST NORTH DAKOTA AS ROBUST CONVECTION ACROSS SOUTHEAST
MONTANA CONTINUES TO PROPAGATE NORTHEAST. WILL HOLD OFF FOR
NOW AS ALL REPORTS HAVE BEEN SUB-SEVERE. HOWEVER...SHOULD
CONVECTION STRENGTHEN AS IT APPROACHES BAKER...A WATCH EXPANSION
MAY BE NEEDED.
UPDATE ISSUED AT 410 PM CDT THU JUL 24 2014
SEVERE THUNDERSTORM WATCH 439 HAS BEEN ISSUED FOR NORTHWEST NORTH
DAKOTA THROUGH 03 UTC. PER COORDINATION WITH SPC...SEVERE
CONVECTION ACROSS NORTHWEST NORTH DAKOTA WILL LIKELY HOLD OFF
UNTIL AROUND 00-01 UTC AS STORMS ACROSS NORTH CENTRAL AND NORTHEAST
MONTANA COINCIDENT WITH THE BEST UPPER LEVEL FORCING PROPAGATE
EAST INTO NORTH DAKOTA...CLOSE TO THE 19 UTC HRRR SOLUTION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
SURFACE LOW OVER CENTRAL ALBERTA WITH A TROUGH EXTENDING SOUTHWARD
INTO CENTRAL/EASTERN MONTANA TO THE WYOMING/SOUTH DAKOTA BORDER. AT
UPPER LEVELS...STRONG UPPER LOW OVER CENTRAL ALBERTA WITH SOUTHWEST
FLOW ALOFT AND EMBEDDED SHORTWAVE ENERGY IMPULSES FORECAST TO MOVE
THROUGH THE UPPER LEVEL FLOW. MOST OF THE UPPER LEVEL ENERGY APPEARS
TO BE FOCUSED MORE NORTH OF THE CANADIAN BORDER...BUT PLENTY OF CAPE
AND SHEAR IN PLACE SOUTHWARD ALONG AND AHEAD OF THE SURFACE TROUGH.
MID-LEVEL CAP WAS BUILDING AHEAD OF THE TROUGH...BUT ISOLATED
ELEVATED THUNDERSTORMS HAD DEVELOPED OVER WESTERN NORTH DAKOTA AND
WERE MOVING EAST AT 30-35 MPH...LIKELY ASSOCIATED WITH WEAK UPPER
LEVEL IMPULSES IN THE UPPER FLOW - BUT NOT SURFACE-BASED.
THE MAIN ACTION IS EXPECTED LATER THIS AFTERNOON/EARLY EVENING AS
THE SURFACE TROUGH MOVES INTO WESTERN NORTH DAKOTA...AND INTO
CENTRAL NORTH DAKOTA THROUGH THE EVENING. THIS WILL BE SUPPORTED BY
MORE VIGOROUS UPPER LEVEL IMPULSES. SEVERE STORMS POSSIBLE...BUT
BEST CAPE IS ALONG AND AHEAD OF THE TROUGH...AND THE BEST SHEAR IS
RIGHT ALONG AND BEHIND THE TROUGH.
EXPECTING BEST CHANCES OF THUNDERSTORMS IN THE WEST LATE AFTERNOON
AND EARLY EVENING...AND BEST CHANCES IN THE CENTRAL FROM MID/LATE
EVENING INTO THE EARLY MORNING HOURS.
FRIDAY LOOKS DRY AND BREEZY WEST WINDS WITH HIGHS MAINLY IN THE
UPPER 70S TO MID 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
UPPER LEVEL LOW PROPAGATING EAST ACROSS SOUTH CENTRAL
CANADA...INTO FAR SOUTHEASTERN SASKATCHEWAN BY 12Z SAT...WILL
DRAG A SURFACE COLD FRONT THROUGH THE NORTHERN PLAINS SATURDAY
MORNING...THEN A SECONDARY COLD FRONT SATURDAY AFTERNOON/EVENING
AS THE LOW CONTINUES TOWARDS NORTHWESTERN MN. UPPER LEVEL FORCING
WITH THE LOW COUPLED WITH SFC CONVERGENCE ALONG THE FRONT WILL
BOTH COMBINE WITH LINGERING BOUNDARY LAYER MOISTURE TO RESULT IN
SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE NORTH SAT
MORNING...WITH COVERAGE OF PRECIPITATION SPREADING SOUTHEAST
DURING THE DAY.
SLIGHT CHANCES FOR PRECIPITATION OVER MY FAR EASTERN COUNTIES SAT
NIGHT/SUNDAY WITH THE UPPER LEVEL JET ACROSS THE MIDWEST.
STRONG SURFACE HIGH PRESSURE BUILDS INTO THE REGION SUNDAY/SUNDAY
NIGHT AHEAD OF AN UPPER LEVEL RIDGE OVER THE WESTERN CONUS...THEN
REMAINS QUASI-STATIONARY THROUGH THE DAY TUESDAY GIVING THE
NORTHERN PLAINS REGION A DRY WEATHER SPELL. BOTH THE 12Z GFS/ECMWF
INDICATE RIDGE RIDER S/WVS MOVING THROUGH THE DAKOTAS TUESDAY
NIGHT THROUGH THURSDAY. WITH THE SFC HIGH MOVING SOUTHEAST...WILL
SEE SPOTTY SHOWER/THUNDERSTORM CHANCES BEGINNING MID-WEEK.
TEMPERATURES WILL BE ON THE COOL SIDE FOR THE END OF JULY SAT-
MON...IN THE 70S...THEN WARM INTO THE 80S TUE-THURS WITH THE
BUILDING RIDGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1018 PM CDT THU JUL 24 2014
THUNDERSTORMS ALONG A FRONTAL BOUNDARY ACROSS WESTERN NORTH DAKOTA
THIS EVENING WILL CONTINUE TO MOVE EAST INTO CENTRAL NORTH DAKOTA
INTO THE OVERNIGHT. VFR CONDITIONS ARE EXPECTED OUTSIDE OF THUNDERSTORMS.
SEE TAF FORECASTS FOR THUNDERSTORM TIMING AND DETAILS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
852 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 851 PM CDT THU JUL 24 2014
ISSUED A WIND ADVISORY FOR STRONG WINDS BEHIND THE OCCLUDING FRONT
ACROSS SOUTHWEST NORTH DAKOTA THROUGH 06 UTC.
UPDATE ISSUED AT 812 PM CDT THU JUL 24 2014
VERY STRONG WESTERLY WINDS WITH GUSTS IN EXCESS OF 50KTS HAVE BEEN
WIDESPREAD BEHIND THE LINE OF CONVECTION AND OCCLUDING FRONT
ACROSS NORTHEAST MONTANA. THIS IS EXPECTED TO CONTINUE INTO MUCH
OF WESTERN NORTH DAKOTA BEHIND THE LINE OF STORMS. THUS...A HIGH
WIND WARNING HAS BEEN ISSUED THROUGH 06 UTC FOR MUCH OF THE WEST.
UPDATE ISSUED AT 655 PM CDT THU JUL 24 2014
PER COORDINATION WITH SPC...SEVERE THUNDERSTORM WATCH 439 HAS BEEN
EXPANDED TO INCLUDE THE SOUTHWEST COUNTIES OF GOLDEN
VALLEY...BILLINGS...STARK...SLOPE...BOWMAN...HETTINGER AND ADAMS
COUNTIES UNTIL 03 UTC.
UPDATE ISSUED AT 540 PM CDT THU JUL 24 2014
THE 20 UTC AND INCOMING 21 UTC HRRR ITERATIONS HAVE A GOOD HANDLE
ON THE CURRENT CONVECTION ACROSS EASTERN MONTANA...AND WILL LEAN
HEAVILY ON THEIR SOLUTIONS FOR THE REMAINDER OF THE EVENING AND
OVERNIGHT. DID COORDINATE WITH SPC AT 2230 UTC REGARDING A
POTENTIAL EXPANSION OF SEVERE THUNDERSTORM WATCH 439 INTO
SOUTHWEST NORTH DAKOTA AS ROBUST CONVECTION ACROSS SOUTHEAST
MONTANA CONTINUES TO PROPAGATE NORTHEAST. WILL HOLD OFF FOR
NOW AS ALL REPORTS HAVE BEEN SUB-SEVERE. HOWEVER...SHOULD
CONVECTION STRENGTHEN AS IT APPROACHES BAKER...A WATCH EXPANSION
MAY BE NEEDED.
UPDATE ISSUED AT 410 PM CDT THU JUL 24 2014
SEVERE THUNDERSTORM WATCH 439 HAS BEEN ISSUED FOR NORTHWEST NORTH
DAKOTA THROUGH 03 UTC. PER COORDINATION WITH SPC...SEVERE
CONVECTION ACROSS NORTHWEST NORTH DAKOTA WILL LIKELY HOLD OFF
UNTIL AROUND 00-01 UTC AS STORMS ACROSS NORTH CENTRAL AND NORTHEAST
MONTANA COINCIDENT WITH THE BEST UPPER LEVEL FORCING PROPAGATE
EAST INTO NORTH DAKOTA...CLOSE TO THE 19 UTC HRRR SOLUTION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
SURFACE LOW OVER CENTRAL ALBERTA WITH A TROUGH EXTENDING SOUTHWARD
INTO CENTRAL/EASTERN MONTANA TO THE WYOMING/SOUTH DAKOTA BORDER. AT
UPPER LEVELS...STRONG UPPER LOW OVER CENTRAL ALBERTA WITH SOUTHWEST
FLOW ALOFT AND EMBEDDED SHORTWAVE ENERGY IMPULSES FORECAST TO MOVE
THROUGH THE UPPER LEVEL FLOW. MOST OF THE UPPER LEVEL ENERGY APPEARS
TO BE FOCUSED MORE NORTH OF THE CANADIAN BORDER...BUT PLENTY OF CAPE
AND SHEAR IN PLACE SOUTHWARD ALONG AND AHEAD OF THE SURFACE TROUGH.
MID-LEVEL CAP WAS BUILDING AHEAD OF THE TROUGH...BUT ISOLATED
ELEVATED THUNDERSTORMS HAD DEVELOPED OVER WESTERN NORTH DAKOTA AND
WERE MOVING EAST AT 30-35 MPH...LIKELY ASSOCIATED WITH WEAK UPPER
LEVEL IMPULSES IN THE UPPER FLOW - BUT NOT SURFACE-BASED.
THE MAIN ACTION IS EXPECTED LATER THIS AFTERNOON/EARLY EVENING AS
THE SURFACE TROUGH MOVES INTO WESTERN NORTH DAKOTA...AND INTO
CENTRAL NORTH DAKOTA THROUGH THE EVENING. THIS WILL BE SUPPORTED BY
MORE VIGOROUS UPPER LEVEL IMPULSES. SEVERE STORMS POSSIBLE...BUT
BEST CAPE IS ALONG AND AHEAD OF THE TROUGH...AND THE BEST SHEAR IS
RIGHT ALONG AND BEHIND THE TROUGH.
EXPECTING BEST CHANCES OF THUNDERSTORMS IN THE WEST LATE AFTERNOON
AND EARLY EVENING...AND BEST CHANCES IN THE CENTRAL FROM MID/LATE
EVENING INTO THE EARLY MORNING HOURS.
FRIDAY LOOKS DRY AND BREEZY WEST WINDS WITH HIGHS MAINLY IN THE
UPPER 70S TO MID 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
UPPER LEVEL LOW PROPAGATING EAST ACROSS SOUTH CENTRAL
CANADA...INTO FAR SOUTHEASTERN SASKATCHEWAN BY 12Z SAT...WILL
DRAG A SURFACE COLD FRONT THROUGH THE NORTHERN PLAINS SATURDAY
MORNING...THEN A SECONDARY COLD FRONT SATURDAY AFTERNOON/EVENING
AS THE LOW CONTINUES TOWARDS NORTHWESTERN MN. UPPER LEVEL FORCING
WITH THE LOW COUPLED WITH SFC CONVERGENCE ALONG THE FRONT WILL
BOTH COMBINE WITH LINGERING BOUNDARY LAYER MOISTURE TO RESULT IN
SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE NORTH SAT
MORNING...WITH COVERAGE OF PRECIPITATION SPREADING SOUTHEAST
DURING THE DAY.
SLIGHT CHANCES FOR PRECIPITATION OVER MY FAR EASTERN COUNTIES SAT
NIGHT/SUNDAY WITH THE UPPER LEVEL JET ACROSS THE MIDWEST.
STRONG SURFACE HIGH PRESSURE BUILDS INTO THE REGION SUNDAY/SUNDAY
NIGHT AHEAD OF AN UPPER LEVEL RIDGE OVER THE WESTERN CONUS...THEN
REMAINS QUASI-STATIONARY THROUGH THE DAY TUESDAY GIVING THE
NORTHERN PLAINS REGION A DRY WEATHER SPELL. BOTH THE 12Z GFS/ECMWF
INDICATE RIDGE RIDER S/WVS MOVING THROUGH THE DAKOTAS TUESDAY
NIGHT THROUGH THURSDAY. WITH THE SFC HIGH MOVING SOUTHEAST...WILL
SEE SPOTTY SHOWER/THUNDERSTORM CHANCES BEGINNING MID-WEEK.
TEMPERATURES WILL BE ON THE COOL SIDE FOR THE END OF JULY SAT-
MON...IN THE 70S...THEN WARM INTO THE 80S TUE-THURS WITH THE
BUILDING RIDGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 850 PM CDT THU JUL 24 2014
STRONG TO SEVERE THUNDERSTORMS ALONG A FRONTAL BOUNDARY ACROSS
EASTERN MONTANA EARLY THIS EVENING WILL CONTINUE TO MOVE EAST INTO
WESTERN AND CENTRAL NORTH DAKOTA LATER THIS EVENING AND INTO THE
OVERNIGHT. VFR CONDITIONS ARE EXPECTED OUTSIDE OF THUNDERSTORMS.
SEE TAF FORECASTS FOR THUNDERSTORM TIMING AND DETAIL. STRONG
WESTERLY WIND GUSTS IN EXCESS OF 50 KTS ARE EXPECTED TO CONTINUE
BEHIND THE LINE OF STORMS AT KISN THROUGH 05-06 UTC...WITH GUSTS
OF 35-40KTS AT KDIK.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 1 AM CDT /MIDNIGHT MDT/ FRIDAY FOR
NDZ001-002-009-010-017-018-031-032.
WIND ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR NDZ033-040-041-043-
044.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
812 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 812 PM CDT THU JUL 24 2014
VERY STRONG WESTERLY WINDS WITH GUSTS IN EXCESS OF 50KTS HAVE BEEN
WIDESPREAD BEHIND THE LINE OF CONVECTION AND OCCLUDING FRONT
ACROSS NORTHEAST MONTANA. THIS IS EXPECTED TO CONTINUE INTO MUCH
OF WESTERN NORTH DAKOTA BEHIND THE LINE OF STORMS. THUS...A HIGH
WIND WARNING HAS BEEN ISSUED THROUGH 06 UTC FOR MUCH OF THE WEST.
UPDATE ISSUED AT 655 PM CDT THU JUL 24 2014
PER COORDINATION WITH SPC...SEVERE THUNDERSTORM WATCH 439 HAS BEEN
EXPANDED TO INCLUDE THE SOUTHWEST COUNTIES OF GOLDEN
VALLEY...BILLINGS...STARK...SLOPE...BOWMAN...HETTINGER AND ADAMS
COUNTIES UNTIL 03 UTC.
UPDATE ISSUED AT 540 PM CDT THU JUL 24 2014
THE 20 UTC AND INCOMING 21 UTC HRRR ITERATIONS HAVE A GOOD HANDLE
ON THE CURRENT CONVECTION ACROSS EASTERN MONTANA...AND WILL LEAN
HEAVILY ON THEIR SOLUTIONS FOR THE REMAINDER OF THE EVENING AND
OVERNIGHT. DID COORDINATE WITH SPC AT 2230 UTC REGARDING A
POTENTIAL EXPANSION OF SEVERE THUNDERSTORM WATCH 439 INTO
SOUTHWEST NORTH DAKOTA AS ROBUST CONVECTION ACROSS SOUTHEAST
MONTANA CONTINUES TO PROPAGATE NORTHEAST. WILL HOLD OFF FOR
NOW AS ALL REPORTS HAVE BEEN SUB-SEVERE. HOWEVER...SHOULD
CONVECTION STRENGTHEN AS IT APPROACHES BAKER...A WATCH EXPANSION
MAY BE NEEDED.
UPDATE ISSUED AT 410 PM CDT THU JUL 24 2014
SEVERE THUNDERSTORM WATCH 439 HAS BEEN ISSUED FOR NORTHWEST NORTH
DAKOTA THROUGH 03 UTC. PER COORDINATION WITH SPC...SEVERE
CONVECTION ACROSS NORTHWEST NORTH DAKOTA WILL LIKELY HOLD OFF
UNTIL AROUND 00-01 UTC AS STORMS ACROSS NORTH CENTRAL AND NORTHEAST
MONTANA COINCIDENT WITH THE BEST UPPER LEVEL FORCING PROPAGATE
EAST INTO NORTH DAKOTA...CLOSE TO THE 19 UTC HRRR SOLUTION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
SURFACE LOW OVER CENTRAL ALBERTA WITH A TROUGH EXTENDING SOUTHWARD
INTO CENTRAL/EASTERN MONTANA TO THE WYOMING/SOUTH DAKOTA BORDER. AT
UPPER LEVELS...STRONG UPPER LOW OVER CENTRAL ALBERTA WITH SOUTHWEST
FLOW ALOFT AND EMBEDDED SHORTWAVE ENERGY IMPULSES FORECAST TO MOVE
THROUGH THE UPPER LEVEL FLOW. MOST OF THE UPPER LEVEL ENERGY APPEARS
TO BE FOCUSED MORE NORTH OF THE CANADIAN BORDER...BUT PLENTY OF CAPE
AND SHEAR IN PLACE SOUTHWARD ALONG AND AHEAD OF THE SURFACE TROUGH.
MID-LEVEL CAP WAS BUILDING AHEAD OF THE TROUGH...BUT ISOLATED
ELEVATED THUNDERSTORMS HAD DEVELOPED OVER WESTERN NORTH DAKOTA AND
WERE MOVING EAST AT 30-35 MPH...LIKELY ASSOCIATED WITH WEAK UPPER
LEVEL IMPULSES IN THE UPPER FLOW - BUT NOT SURFACE-BASED.
THE MAIN ACTION IS EXPECTED LATER THIS AFTERNOON/EARLY EVENING AS
THE SURFACE TROUGH MOVES INTO WESTERN NORTH DAKOTA...AND INTO
CENTRAL NORTH DAKOTA THROUGH THE EVENING. THIS WILL BE SUPPORTED BY
MORE VIGOROUS UPPER LEVEL IMPULSES. SEVERE STORMS POSSIBLE...BUT
BEST CAPE IS ALONG AND AHEAD OF THE TROUGH...AND THE BEST SHEAR IS
RIGHT ALONG AND BEHIND THE TROUGH.
EXPECTING BEST CHANCES OF THUNDERSTORMS IN THE WEST LATE AFTERNOON
AND EARLY EVENING...AND BEST CHANCES IN THE CENTRAL FROM MID/LATE
EVENING INTO THE EARLY MORNING HOURS.
FRIDAY LOOKS DRY AND BREEZY WEST WINDS WITH HIGHS MAINLY IN THE
UPPER 70S TO MID 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
UPPER LEVEL LOW PROPAGATING EAST ACROSS SOUTH CENTRAL
CANADA...INTO FAR SOUTHEASTERN SASKATCHEWAN BY 12Z SAT...WILL
DRAG A SURFACE COLD FRONT THROUGH THE NORTHERN PLAINS SATURDAY
MORNING...THEN A SECONDARY COLD FRONT SATURDAY AFTERNOON/EVENING
AS THE LOW CONTINUES TOWARDS NORTHWESTERN MN. UPPER LEVEL FORCING
WITH THE LOW COUPLED WITH SFC CONVERGENCE ALONG THE FRONT WILL
BOTH COMBINE WITH LINGERING BOUNDARY LAYER MOISTURE TO RESULT IN
SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE NORTH SAT
MORNING...WITH COVERAGE OF PRECIPITATION SPREADING SOUTHEAST
DURING THE DAY.
SLIGHT CHANCES FOR PRECIPITATION OVER MY FAR EASTERN COUNTIES SAT
NIGHT/SUNDAY WITH THE UPPER LEVEL JET ACROSS THE MIDWEST.
STRONG SURFACE HIGH PRESSURE BUILDS INTO THE REGION SUNDAY/SUNDAY
NIGHT AHEAD OF AN UPPER LEVEL RIDGE OVER THE WESTERN CONUS...THEN
REMAINS QUASI-STATIONARY THROUGH THE DAY TUESDAY GIVING THE
NORTHERN PLAINS REGION A DRY WEATHER SPELL. BOTH THE 12Z GFS/ECMWF
INDICATE RIDGE RIDER S/WVS MOVING THROUGH THE DAKOTAS TUESDAY
NIGHT THROUGH THURSDAY. WITH THE SFC HIGH MOVING SOUTHEAST...WILL
SEE SPOTTY SHOWER/THUNDERSTORM CHANCES BEGINNING MID-WEEK.
TEMPERATURES WILL BE ON THE COOL SIDE FOR THE END OF JULY SAT-
MON...IN THE 70S...THEN WARM INTO THE 80S TUE-THURS WITH THE
BUILDING RIDGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 812 PM CDT THU JUL 24 2014
STRONG TO SEVERE THUNDERSTORMS ALONG A FRONTAL BOUNDARY ACROSS
EASTERN MONTANA EARLY THIS EVENING WILL CONTINUE TO MOVE EAST INTO
WESTERN AND CENTRAL NORTH DAKOTA LATER THIS EVENING AND INTO THE
OVERNIGHT. VFR CONDITIONS ARE EXPECTED OUTSIDE OF THUNDERSTORMS.
SEE TAF FORECASTS FOR THUNDERSTORM TIMING AND DETAIL. STRONG
WESTERLY WIND GUSTS IN EXCESS OF 50 KTS ARE EXPECTED TO CONTINUE
BEHIND THE LINE OF STORMS AT KISN THROUGH 05-06 UTC.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 1 AM CDT /MIDNIGHT MDT/ FRIDAY FOR
NDZ001-002-009-010-017-018-031-032.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
656 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 655 PM CDT THU JUL 24 2014
PER COORDINATION WITH SPC...SEVERE THUNDERSTORM WATCH 439 HAS BEEN
EXPANDED TO INCLUDE THE SOUTHWEST COUNTIES OF GOLDEN
VALLEY...BILLINGS...STARK...SLOPE...BOWMAN...HETTINGER AND ADAMS
COUNTIES UNTIL 03 UTC.
UPDATE ISSUED AT 540 PM CDT THU JUL 24 2014
THE 20 UTC AND INCOMING 21 UTC HRRR ITERATIONS HAVE A GOOD HANDLE
ON THE CURRENT CONVECTION ACROSS EASTERN MONTANA...AND WILL LEAN
HEAVILY ON THEIR SOLUTIONS FOR THE REMAINDER OF THE EVENING AND
OVERNIGHT. DID COORDINATE WITH SPC AT 2230 UTC REGARDING A
POTENTIAL EXPANSION OF SEVERE THUNDERSTORM WATCH 439 INTO
SOUTHWEST NORTH DAKOTA AS ROBUST CONVECTION ACROSS SOUTHEAST
MONTANA CONTINUES TO PROPAGATE NORTHEAST. WILL HOLD OFF FOR
NOW AS ALL REPORTS HAVE BEEN SUB-SEVERE. HOWEVER...SHOULD
CONVECTION STRENGTHEN AS IT APPROACHES BAKER...A WATCH EXPANSION
MAY BE NEEDED.
UPDATE ISSUED AT 410 PM CDT THU JUL 24 2014
SEVERE THUNDERSTORM WATCH 439 HAS BEEN ISSUED FOR NORTHWEST NORTH
DAKOTA THROUGH 03 UTC. PER COORDINATION WITH SPC...SEVERE
CONVECTION ACROSS NORTHWEST NORTH DAKOTA WILL LIKELY HOLD OFF
UNTIL AROUND 00-01 UTC AS STORMS ACROSS NORTH CENTRAL AND NORTHEAST
MONTANA COINCIDENT WITH THE BEST UPPER LEVEL FORCING PROPAGATE
EAST INTO NORTH DAKOTA...CLOSE TO THE 19 UTC HRRR SOLUTION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
SURFACE LOW OVER CENTRAL ALBERTA WITH A TROUGH EXTENDING SOUTHWARD
INTO CENTRAL/EASTERN MONTANA TO THE WYOMING/SOUTH DAKOTA BORDER. AT
UPPER LEVELS...STRONG UPPER LOW OVER CENTRAL ALBERTA WITH SOUTHWEST
FLOW ALOFT AND EMBEDDED SHORTWAVE ENERGY IMPULSES FORECAST TO MOVE
THROUGH THE UPPER LEVEL FLOW. MOST OF THE UPPER LEVEL ENERGY APPEARS
TO BE FOCUSED MORE NORTH OF THE CANADIAN BORDER...BUT PLENTY OF CAPE
AND SHEAR IN PLACE SOUTHWARD ALONG AND AHEAD OF THE SURFACE TROUGH.
MID-LEVEL CAP WAS BUILDING AHEAD OF THE TROUGH...BUT ISOLATED
ELEVATED THUNDERSTORMS HAD DEVELOPED OVER WESTERN NORTH DAKOTA AND
WERE MOVING EAST AT 30-35 MPH...LIKELY ASSOCIATED WITH WEAK UPPER
LEVEL IMPULSES IN THE UPPER FLOW - BUT NOT SURFACE-BASED.
THE MAIN ACTION IS EXPECTED LATER THIS AFTERNOON/EARLY EVENING AS
THE SURFACE TROUGH MOVES INTO WESTERN NORTH DAKOTA...AND INTO
CENTRAL NORTH DAKOTA THROUGH THE EVENING. THIS WILL BE SUPPORTED BY
MORE VIGOROUS UPPER LEVEL IMPULSES. SEVERE STORMS POSSIBLE...BUT
BEST CAPE IS ALONG AND AHEAD OF THE TROUGH...AND THE BEST SHEAR IS
RIGHT ALONG AND BEHIND THE TROUGH.
EXPECTING BEST CHANCES OF THUNDERSTORMS IN THE WEST LATE AFTERNOON
AND EARLY EVENING...AND BEST CHANCES IN THE CENTRAL FROM MID/LATE
EVENING INTO THE EARLY MORNING HOURS.
FRIDAY LOOKS DRY AND BREEZY WEST WINDS WITH HIGHS MAINLY IN THE
UPPER 70S TO MID 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
UPPER LEVEL LOW PROPAGATING EAST ACROSS SOUTH CENTRAL
CANADA...INTO FAR SOUTHEASTERN SASKATCHEWAN BY 12Z SAT...WILL
DRAG A SURFACE COLD FRONT THROUGH THE NORTHERN PLAINS SATURDAY
MORNING...THEN A SECONDARY COLD FRONT SATURDAY AFTERNOON/EVENING
AS THE LOW CONTINUES TOWARDS NORTHWESTERN MN. UPPER LEVEL FORCING
WITH THE LOW COUPLED WITH SFC CONVERGENCE ALONG THE FRONT WILL
BOTH COMBINE WITH LINGERING BOUNDARY LAYER MOISTURE TO RESULT IN
SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE NORTH SAT
MORNING...WITH COVERAGE OF PRECIPITATION SPREADING SOUTHEAST
DURING THE DAY.
SLIGHT CHANCES FOR PRECIPITATION OVER MY FAR EASTERN COUNTIES SAT
NIGHT/SUNDAY WITH THE UPPER LEVEL JET ACROSS THE MIDWEST.
STRONG SURFACE HIGH PRESSURE BUILDS INTO THE REGION SUNDAY/SUNDAY
NIGHT AHEAD OF AN UPPER LEVEL RIDGE OVER THE WESTERN CONUS...THEN
REMAINS QUASI-STATIONARY THROUGH THE DAY TUESDAY GIVING THE
NORTHERN PLAINS REGION A DRY WEATHER SPELL. BOTH THE 12Z GFS/ECMWF
INDICATE RIDGE RIDER S/WVS MOVING THROUGH THE DAKOTAS TUESDAY
NIGHT THROUGH THURSDAY. WITH THE SFC HIGH MOVING SOUTHEAST...WILL
SEE SPOTTY SHOWER/THUNDERSTORM CHANCES BEGINNING MID-WEEK.
TEMPERATURES WILL BE ON THE COOL SIDE FOR THE END OF JULY SAT-
MON...IN THE 70S...THEN WARM INTO THE 80S TUE-THURS WITH THE
BUILDING RIDGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 540 PM CDT THU JUL 24 2014
STRONG TO SEVERE THUNDERSTORMS ALONG A FRONTAL BOUNDARY ACROSS
EASTERN MONTANA EARLY THIS EVENING WILL CONTINUE TO MOVE EAST INTO
WESTERN AND CENTRAL NORTH DAKOTA LATER THIS EVENING AND INTO THE
OVERNIGHT. VFR CONDITIONS ARE EXPECTED OUTSIDE OF THUNDERSTORMS.
SEE TAF FORECASTS FOR THUNDERSTORM TIMING AND DETAILS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
540 PM CDT WED JUL 23 2014
.UPDATE...
ISSUED AT 539 PM CDT WED JUL 23 2014
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE. STILL MONITORING
FOR CONVECTIVE INITIATION ACROSS CENTRAL INTO EASTERN MONTANA OVER
THE NEXT ONE TO TWO HOURS. THE 20 UTC HRRR WOULD SUGGEST
MONTANA SURFACE BASED CONVECTION APPROACHING THE NORTH DAKOTA BORDER
BY 03-04 UTC...CONTINUING TO PROPAGATE INTO CENTRAL NORTH DAKOTA
BY 08-09 UTC SUSTAINED BY A 30-35 KT LOW LEVEL JET. THE BEST
CHANCE FOR LARGE HAIL AND DAMAGING WINDS ARE GENERALLY ALONG AND
WEST OF HIGHWAY 85 AS THE MONTANA CONVECTION PROPAGATES INTO
WESTERN NORTH DAKOTA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 320 PM CDT WED JUL 23 2014
FORECAST ISSUES IN THE SHORT TERM ARE THUNDERSTORM CHANCES...AND
POSSIBILITY OF SEVERE STORMS.
CURRENTLY...SURFACE HIGH WAS OVER MANITOBA SOUTHWARD THROUGH THE RED
RIVER VALLEY...WITH LOW PRESSURE IN THE LEE OF THE ROCKIES.
SOUTHEASTERLY FLOW WAS KEEPING MOIST LOW LEVELS WITH DEWPOINTS IN
THE 60S OVER WESTERN AND CENTRAL NORTH DAKOTA. AT UPPER LEVELS...A
SHARP RIDGE WAS IN PLACE FROM SASKATCHEWAN TO THE WESTERN DAKOTAS
AND EASTERN MT/WY. BEST SHEAR AND MID LEVEL LAPSE RATES WERE OVER
THE FRONT RANGE THIS AFTERNOON...WITH MOST UNSTABLE CAPES OVER THE
FRONT RANGE INTO THE WESTERN DAKOTAS.
LATEST MODEL RUNS SUGGEST THUNDERSTORMS DEVELOPING OVER CENTRAL AND
EASTERN MONTANA THIS EVENING IN THE VICINITY OF A MID LEVEL
SHORTWAVE ENERGY IMPULSE FORECAST TO MOVE/DEVELOP INTO NORTHEASTERN
MONTANA DURING THE EVENING. ONCE CONVECTION BECOMES BETTER
ESTABLISHED...THE SCENARIO IS FOR STORMS TO MIGRATE EASTWARD INTO
WESTERN NORTH DAKOTA LATER THIS EVENING...THEN SPREAD INTO CENTRAL
NORTH DAKOTA AFTER MIDNIGHT. THE WESTERN THIRD OF NORTH DAKOTA HAS
THE BEST POTENTIAL FOR SEVERE STORMS LATE THIS EVENING INTO THE
EARLY MORNING HOURS.
ONGOING CONVECTION DAYBREAK THURSDAY OVER MUCH OF CENTRAL NORTH
DAKOTA EXPECTED TO CONTINUE MOVING EASTWARD. THEN...ATTENTION TURNS
TO THE WEST AS A SIGNIFICANT UPPER LOW EMERGES INTO THE FRONT RANGE
FROM THE ROCKIES WITH STRONG SOUTHWEST FLOW ALOFT INTO THE DAKOTAS.
AT THE SAME TIME...THE AFOREMENTIONED SURFACE LOW OVER THE FRONT
RANGE WILL HAVE MOVED/DEVELOPED EASTWARD INTO THE WESTERN DAKOTAS.
THESE INGREDIENTS WILL BE FAVORABLE FOR PLENTY OF SHEAR...CAPE
(ESPECIALLY WITH SURFACE DEWPOINTS IN THE 65 TO 70 DEGREE
RANGE)...AND UPPER LEVEL IMPULSES. GOOD CHANCE OF THUNDERSTORMS
THURSDAY AFTERNOON OVER THE WESTERN THIRD OF THE STATE. THIS WILL
CONTINUE INTO THE EVENING HOURS AS WELL...WITH SEVERE WEATHER
POSSIBLE OVER MUCH OF THE FORECAST AREA THURSDAY AFTERNOON/NIGHT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT WED JUL 23 2014
THE MAIN FEATURES IN THE LONG TERM PERIOD CONTINUE TO BE AN UPPER
LOW OFF THE WA/OR COAST AND ITS INTERACTION WITH THE DOWNSTREAM
H500 RIDGE OVER THE NORTHERN PLAINS. AS THE UPPER LOW MOVES EAST
AND FLATTENS THE RIDGE...A COLD FRONT AT THE SURFACE WILL
POSITION ITSELF ACROSS EASTERN MONTANA BY THURSDAY AFTERNOON. THE
FRONT WILL THEN PUSH EAST ACROSS NORTH DAKOTA THURSDAY
EVENING AND OVERNIGHT INTO FRIDAY MORNING. THUNDERSTORMS...A FEW
POSSIBLY SEVERE WITH STRONG WINDS AND HAIL THE MAIN THREATS WILL
ACCOMPANY THE FRONT AS IT PROGRESSES EAST THROUGH THE STATE
THURSDAY AFTERNOON AND EVENING. ON FRIDAY COOLER BUT STILL
REASONABLY MILD TEMPERATURES IN THE UPPER 70S TO LOWER 80S SHOULD
BE THE RULE. ANY SHOWERS AND ISOLATED THUNDERSTORMS SHOULD BE
LIMITED TO THE EAST. ONE MORE DAY OF SHOWERS/SCATTERED
THUNDERSTORMS ON SATURDAY AS THE SLOW MOVING UPPER LOW TRACKS
SOUTH ACROSS MINNESOTA. WHILE THE STATE WILL GENERALLY BE ON THE
DRY SIDE OF THE UPPER LOW CANT RULE OUT SHOWERS AS COOL AIR ALOFT
SHOULD SUPPORT SOME INSTABILITY...ESPECIALLY NORTH. AS THE UPPER
LOW DRIFTS EAST AND A RIDGE POPS UP IN MONTANA SUNDAY THROUGH
TUESDAY...SHOULD BE DRY WITH GENERALLY PLEASANT TEMPERATURES AND
HUMIDITY FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 539 PM CDT WED JUL 23 2014
VFR CONDITIONS OUTSIDE OF THUNDERSTORMS ARE FORECAST FOR THE 00
UTC TAF CYCLE ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
THUNDERSTORMS ARE FORECAST TO ENTER WESTERN NORTH DAKOTA AROUND
03-04 UTC...AND MOVE INTO CENTRAL NORTH DAKOTA BY 08-09 UTC. SEE
TAFS FOR TIMING AND THREAT DETAILS. ANOTHER ROUND OF THUNDERSTORMS
IS EXPECTED LATE THURSDAY AFTERNOON AND INTO THE EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
207 AM EDT WED JUL 23 2014
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL CONTINUE TO KEEP SOUTHWEST WINDS
AND HUMID AIR OVER THE OHIO VALLEY AHEAD OF IT. THIS FRONT WILL
PUSH THROUGH THE REGION WEDNESDAY AND SPARK A ROUND OF SHOWERS
AND THUNDERSTORMS. A LARGE AREA OF HIGH PRESSURE WILL BUILD BEHIND
IT AND PROVIDE DRY AND COOL WEATHER THROUGH THE END OF THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
DIURNAL CU HAVE DISSIPATED ACROSS THE AREA WITH SKIES CURRENTLY
MOSTLY CLEAR. WE SHOULD SEE AN INCREASE IN HIGH AND MID LEVEL
CLOUDS AS WE HEAD INTO THE OVERNIGHT HOURS AS A COLD FRONT
APPROACHES FROM THE NORTHWEST. A NARROW LINE OF SHOWERS AND
THUNDERSTORMS CURRENTLY ALONG THE FRONT STRETCHING FROM SOUTHERN
WISCONSIN INTO LOWER MICHIGAN WILL CONTINUE TO WORK ITS WAY
SOUTHEAST TOWARD OUR AREA OVERNIGHT. THE HRRR CONTINUES TO SUGGEST
THAT SOME OF THIS COULD MAKE IT DOWN INTO OUR NORTHWEST FA THROUGH
THE EARLY MORNING HOURS...WHILE THE ARW AND NMM WEAKEN AND
DISSIPATE THE STORMS AS THEY MOVE INTO OUR AREA. WILL CONTINUE WITH
SOME LOWER CHANCE POPS ACROSS THE NORTHWEST TO ACCOUNT FOR THE
POSSIBILITY...BUT WITH DECREASING INSTABILITIES...DO EXPECT A
GENERAL WEAKENING TREND TO ANY THUNDERSTORMS THAT DO MAKE IT INTO
OUR FA.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
COLD FRONT IS BEING PROGGED WITH A CONTINUOUSLY FASTER SOLUTION
WITH EACH MODEL RUN. IN THE NW CWA AT 12Z IT IS WELL SOUTHEAST OF
THE I-71 CORRIDOR BY 18Z. PRECIP IN THE COLD POOL BEHIND THE WIND
SHIFT WILL BE HARD PRESSED TO SEE DAMAGING WINDS WITH ANY
CONVECTIVE ELEMENTS AND THE SWODY2 OUTLOOK APPEARS TO WHITTLE AWAY
AT THE SEVERE PROSPECTS WITH EACH DISCUSSION. AT THIS MOMENT...I
WOULD EXPECT A RAINY PERIOD WITH THUNDER BUT THE LACK OF DISTINCT
STRONG CORES/UPDRAFTS NECESSARY FOR WIND/HAIL. ELEVATED
INSTABILITY WILL MAKE FOR OCCASIONAL DOWNPOURS AND WINDS WHEN
THESE ELEVATED CORES COLLAPSE...BUT THE EXPECTED HIGH MOISTURE AND
COLD NATURE OF THE AIR IN THE BOUNDARY LAYER WOULD LIMIT ANY VERY
STRONG WINDS FROM OCCURRING.
HIGHS WERE PROGGED TO BE A BIT WARMER THAN I WOULD EXPECT IN THE
SOUTHEAST WITH A GRUNGY DAY OF CLOUD COVER. LOWERED READINGS A BIT
TO TOP OUT AT 90 DEGREES AS A MAXIMUM AND THINK THAT THIS WOULD BE
AN EARLY AFTERNOON HIGH WITH STRONG ADVECTION FROM A SUNNY POCKET
OVER KY BEING PULLED INTO MY NRN KY AND SERN OH COUNTIES. NW CWA
WILL BE THOROUGHLY GRUNGED AND NOT REACH PAST THE 70S.
AFTER PRECIP ENDS TOMORROW NIGHT...HIGH PRESSURE WILL PUSH IN
DRIER AND COOLER AIR TO THE OHIO VALLEY AND THIS WILL REMAIN IN
PLACE THROUGH THE END OF THE WORK WEEK.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
SURFACE HIGH PRESSURE WILL BE CENTERED ACROSS THE OHIO VALLEY ON
FRIDAY. THIS HIGH WILL QUICKLY SLIDE SOUTHEAST OF OUR REGION AND
WEAKEN AS AN UPPER LEVEL DISTURBANCE EMBEDDED IN NORTHWESTERLY
FLOW APPROACHES OUR REGION. MODELS HAVE ACCELERATED THE ARRIVAL OF
THIS DISTURBANCE...YET STILL VARY BY SEVERAL HOURS ON THEIR
FORECAST ARRIVAL OF PRECIPITATION ON SATURDAY. ADDED LOW CHANCE
POPS EARLY SATURDAY MORNING WITH POPS RAMPING UP INTO THE DAY
SATURDAY BASED ON THE FASTER TREND. KEPT ONLY CHANCE POPS ON
SATURDAY DUE TO TIMING AND COVERAGE UNCERTAINTIES FOR
PRECIPITATION ON SATURDAY. TEMPERATURES UNDER THE HIGH ON FRIDAY
WILL REMAIN A FEW DEGREES BELOW NORMAL. ONCE THE HIGH SHIFTS TO
OUR SOUTHEAST...A REBOUND TO NEAR NORMAL TEMPERATURES CAN BE
EXPECTED FOR SATURDAY.
ON SUNDAY...A UNSEASONABLY DEEP TROUGH IS EXPECTED TO DIG
SOUTHEASTWARD ACROSS THE MID WEST AND INTO THE OHIO VALLEY. LOW
PRESSURE DOWNSTREAM OF THIS TROUGH WILL DRAG A COLD FRONT ACROSS OUR
AREA. THE CMC AND GFS ARE IN FAIRLY GOOD AGREEMENT ON BRINGING
ENHANCED CHANCES FOR PRECIPITATION TO OUR AREA ON SUNDAY AHEAD OF
THIS FRONT...WITH THE COLD FRONT CROSSING OUR AREA AT SOME POINT
LATE SUNDAY. BEST CHANCES FOR PRECIPITATION APPEAR TO BE DURING THE
DAY SUNDAY IN THE WARM SECTOR...WITH COOLER AIR MOVING INTO THE
REGION BY MONDAY. THE TROUGH IS FORECAST TO REMAIN IN THE REGION
THROUGH THE EARLY PARTS OF NEXT WEEK. MODELS VARY ON HOW MUCH
MOISTURE LINGERS BEHIND THE FRONT. AM FORECASTING MAINLY LOW CHANCE
DIURNALLY DRIVEN SHOWERS AND ISOLATED THUNDERSTORMS IN THE COLD
SECTOR. THIS HIGH AMPLITUDE TROUGH WILL BRING ANOTHER ROUND OF WELL
BELOW NORMAL TEMPERATURES TO THE OHIO VALLEY EARLY NEXT WEEK...WITH
CURRENT INDICATIONS BEING THAT HIGHS MAY ONLY REACH THE LOWER 70S ON
MONDAY AND POSSIBLY AGAIN ON TUESDAY.
&&
.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
A STRONG COLD FRONT WILL DROP DOWN FROM THE NORTHWEST TODAY AND
PUSH ACROSS THE TAF SITES LATE THIS MORNING INTO EARLY AFTERNOON.
LATEST RADAR MOSAIC SHOWS CONVECTION ALONG AND AHEAD OF THIS FRONT
PUSHING INTO NORTHWEST OHIO. THESE STORMS WILL MOVE SE PUSHING INTO
TAF SITES EARLY THIS MORNING. INSTABILITY WILL BE DECREASING...SO
STORMS EXPECTED TO WEAKEN AND DIMINISH IN COVERAGE. EXPECT MID/HIGH
LEVEL CLOUDS TO INCREASE AHEAD OF THIS FRONT. PRIOR TO THIS INCREASE
IN CLOUDS SOME FOG AND MVFR VSBY RESTRICTION WILL BE PSBL AT
KLUK...KILN AND KLCK. HAVE A MENTION OF VCTS FOR THIS INITIAL
POTENTIAL OF THUNDERSTORMS EARLY. BETTER THUNDERSTORM CONVERGE
EXPECTED TO DEVELOP ALONG THE FRONT AS MODERATE INSTBY DEVELOPS
THIS AFTN. THE BEST CHANCE FOR THIS LOOKS TO BE ALONG AND SE OF
I-71. HAVE A MENTION OF SHOWERS WITH VCTS TO ACCOUNT FOR FROPA
INTO MID AFTERNOON. EXPECT WINDS TO SHIFT TO THE NORTHWEST AND
THEN NE WITH VFR CONDITIONS THIS EVENING.
OUTLOOK...THUNDERSTORMS POSSIBLE SATURDAY AND SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...JGL
SHORT TERM...FRANKS
LONG TERM...LATTO
AVIATION...AR
AREA FORECAST DISCUSSION
NWS TULSA OK
1140 PM CDT TUE JUL 22 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
CONVECTION IS EXPECTED TO INCREASE IN COVERAGE POSSIBLY LATER
TONIGHT AND/OR TUESDAY AFTERNOON. THIS WILL BE ASSOCIATED WITH A
WEAKENING FRONTAL BOUNDARY AS IT SETTLES INTO THE REGION. PATCHY
LIGHT FOG WILL ALSO BE POSSIBLE TONIGHT...OTHERWISE VFR CONDITIONS
ARE EXPECTED TO PREVAIL OUTSIDE OF ANY STRONGER CONVECTION.
&&
.PREV DISCUSSION... /ISSUED 921 PM CDT TUE JUL 22 2014/
..UPDATE...
DISCUSSION...
TEMPS IN THE UPPER 70S TO UPPER 80S REMAINED COMMON ACROSS EASTERN
OKLAHOMA AND NORTHWEST ARKANSAS THIS EVENING. HEAT INDICES HAVE
ALSO COME DOWN SOME WITH VALUES IN THE RANGE FORM THE MID 80S TO
MID 90S STILL BEING REPORTED OVER NORTHEAST OKLAHOMA. TO THE NORTH
OF THE CWA...A WEAK COLD FRONT REMAINED POSITIONED ACROSS NORTHERN
KANSAS AND NORTHERN MISSOURI. THIS FRONT IS EXPECTED TO SAG
SOUTHWARD OVERNIGHT AND MOVE INTO THE FAR NORTHERN PART OF THE CWA
WEDNESDAY MORNING. LATEST RUNS OF THE LOCAL IN-HOUSE MODEL AS
WELL AS THE HRRR TRY TO DEVELOP THUNDERSTORMS ALONG/AHEAD OF THE
FRONT AND PUSH THEM INTO NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS
ALONG AN OUTFLOW BOUNDARY LATE TONIGHT. THE HRRR RUNS SAYS THAT
THERE SHOULD ALREADY BE ONGOING CONVECTION ACROSS CENTRAL
KANSAS...THROUGH LOOKING AT LATEST SATELLITE DATA...THERE SEEMS BE
LITTLE IN THE WAY OF CLOUD COVER. THE CAP OVER THE REGION LOOKS TO
BE NOT QUITE AS STRONG COMPARED TO OVER KANSAS THIS EVENING AND
THIS COULD ALLOW FOR SOME THUNDERSTORM ACTIVITY LATE TONIGHT TO
DEVELOP AND MOVE INTO THE CWA. THUS...WILL KEEP A SLIGHT CHANCE
POP OVER PARTS OF NORTHEAST OKLAHOMA INTO NORTHWEST ARKANSAS LATE
TONIGHT. THE BETTER CHANCES LOOK TO BE DURING THE DAY WEDNESDAY AS
THE FRONT ENTERS THE CWA AND INTERACTS WITH DAYTIME
HEATING/INSTABILITY. EVENING UPDATE WILL BE TO TWEAK POPS/WX A BIT
OTHERWISE THE REST OF THE FORECAST SEEMS TO BE HANDLING WELL.
EVEN WITH THE WEAK FRONT MOVING THROUGH THE REGION...HOT AND HUMID
CONDITIONS STILL LOOK POSSIBLE OVER THE REGION...ESPECIALLY SOUTH
OF THE BOUNDARY. WILL KEEP THE CURRENT HEAT HEADLINES AS IS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 76 98 72 94 / 10 30 10 0
FSM 73 96 72 93 / 20 50 20 10
MLC 71 95 72 96 / 10 20 20 10
BVO 71 95 68 94 / 10 30 10 0
FYV 68 90 67 88 / 20 50 20 10
BYV 69 90 65 86 / 20 50 10 10
MKO 72 96 71 94 / 20 30 10 10
MIO 72 92 68 91 / 20 50 10 10
F10 73 96 72 94 / 10 20 10 10
HHW 71 95 74 96 / 10 10 20 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...EXCESSIVE HEAT WARNING UNTIL 8 PM WEDNESDAY FOR OKZ060.
HEAT ADVISORY FROM 1 PM WEDNESDAY TO 8 PM WEDNESDAY FOR OKZ054-
OKZ055-OKZ056-OKZ059-OKZ061-OKZ062-OKZ064-OKZ065-OKZ066-
OKZ067-OKZ068-OKZ070-OKZ071-OKZ072-OKZ074.
AR...NONE.
&&
$$
AVIATION...07
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1035 AM EDT WED JUL 23 2014
.SYNOPSIS...
A COLD FRONT WILL PUSH SOUTHEAST ACROSS THE COMMONWEALTH LATE
TODAY AND TONIGHT. A REFRESHING...COOLER AND LESS HUMID AIRMASS
WILL OVERSPREAD THE COMMONWEALTH FOR THE END OF THE WEEK INTO THE
WEEKEND.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
10 AM UPDATE...
RADAR ECHOES IN NW PA NOT BELOW FL120...SO LITTLE PRECIP FORSEEN
THERE UNTIL ANY DIURNAL CONVECTION FLARES UP ALONG THE BEST WIND
SHIFT/DEWPOINT BOUNDARY WHICH IS JUST CROSSING THE LAKES NOW.
ALSO...TEMPS RUNNING A FEW DEGS AHEAD OF THE CURVE AT THIS POINT
WITH STRONG SUNSHINE OVER THE SERN 2/3RDS OF THE AREA.
THUS...CONVECTIVE TEMPS SHOULD BE REACHED VERY SOON - ESP ON THE
HIGHER HILLS OF THE SERN HALF OF THE AREA. THIS COMBINE WITH A BIT
OF A PRE-FRONTAL TROUGH EVIDENT IN THE SFC PRESSURES AT 15Z WILL
CREATE SCT SHRA IN THE SE BY 18Z. EXPECT THE WARM AIR ALOFT WHICH
IS SEEN IN BOTH BALLOON AND MODEL SOUNDINGS TO KEEP THE CONVECTION
SHORT UNTIL MID AFTERNOON. HOWEVER...THE INSTABILITY AND LLVL
MOISTURE SHOULD BE ENOUGH TO GENERATE VERY LARGE CAPES THIS AFTN
AND EARLY THIS EVENING. WILL TWEAK POPS WITH AN EYE TOWARD MORE IN
THE SE AND LESS IN THE NW FOR THE FIRST FEW HRS OF THE PERIOD.
TEMPS WILL PROBABLY RISE ABOVE 90F IN MANY LOCATION IN THE EASTERN
VALLEYS...EXCEPT WHERE THE EARLY AFTN ISOLD/SCT CONVECTION COOLS
THEM OFF.
PREV...
WEAK RIDGING OVER THE REGION AT THE SURFACE AND ALOFT...COMBINED
WITH VERY WARM MID LEVEL TEMPS OF 9-11C WILL KEEP CONDITIONS
MAINLY CLEAR BUT MUGGY INTO THE LATE MORNING HOURS.
CURRENT DEWPOINTS IN THE MID TO UPPER 60S ARE A FEW DEG SHY OF
THE EXPECTED MIN TEMPS AROUND SUNRISE.
CIRRUS BLOWOFF FROM A WEAKENING LINE OF SHOWERS AND THUNDERSTORMS
OVER LAKE ERIE WILL OVERSPREAD THE NW MTNS THIS MORNING...BUT
THEN DISSIPATE FOR THE MIDDAY HOURS BEFORE NEW CONVECTION
INITIATES ALONG/AHEAD OF AN APPROACHING COLD FRONT.
THE BKN LINE OF SHRA/TSRA SLIDING SE ACROSS CENTRAL LAKE ERIE ATTM
IS OVER LOCALLY COOLER AND MORE STABLE LLVLS...AND IS PROGGED BY
THE LAST FEW RUNS OF THE HRRR TO STEADILY WEAKEN...AND EVEN
DISSIPATE AS IT MOVES ONTO THE SOUTH SHORE DURING THE NEXT
FEW HOURS AND ENCOUNTERS THE VERY STRONG MID-LEVEL CAP ACROSS
NWRN PENN. 15-MINUTE LIGHTNING FREQUENCY HAS DROPPED OFF
DRAMATICALLY OVER THE PAST HOUR. STILL PAINTED CHC POPS FOR
SHOWERS OR A RUMBLE OF THUNDER ACROSS NW WARREN COUNTY AROUND 12Z
SINCE EARLIER RUNS OF THE HRRR HAD NO SIGN OF CONVECTION EVEN
REACHING THE CENTRAL WATERS OF LAKE ERIE ATTM.
A DRY START TO THE DAY AND MAINLY SUNNY SKIES ACROSS ALL BUT THE
FAR NW ZONES...WILL GIVE WAY TO INCREASING CHANCES FOR SHOWERS
AND THUNDERSTORMS THIS AFTERNOON AS LARGE SCALE FORCING INCREASES
ASSOCIATED WITH THE APPROACHING COLD FRONT.
SPC HAS MAINTAINED A /SEE TEXT/ FOR ALL OF PENN WITHIN THEIR DAY
1 CONVECTIVE OUTLOOK...WITH EASTERN NEW YORK AND NEW ENGLAND UNDER
THE GUN FOR A SLIGHT RISK OF SVR TSRA GIVEN THE BETTER COMBINATION
OF STRONGER DEEP LAYER SHEAR AND CAPE. STILL...MODERATE-HIGH SFC
BASED CAPE IN EXCESS OF 2000 J/KG...COMBINED WITH ABOUT 20 KTS OF
0-6KM BULK SHEAR SHOULD BE SUFFICIENT FOR A FEW OCCURRENCES OF
DAMAGING MICROBURSTS AND HAIL ACROSS THE CWA THIS AFTERNOON INTO
THIS EVENING.
THE LOW-LEVEL...WSW DOWNSLOPE FLOW/COMPRESSIONAL WARMING OF THE
AIRMASS AHEAD OF THE CFRONT...WILL LEAD TO THE HIGHEST TEMPS OF
THE WEEK. AFTERNOON MAX TEMPS WILL RANGE FROM THE LOWER 80S
ACROSS THE HIGH TERRAIN OF THE NORTH AND WEST...TO THE MID AND
UPPER 80S IN THE CENTRAL VALLEYS...AND LOWER 90S IN THE GREATER
YORK/HARRISBURG AREA.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 AM THURSDAY/...
THE FOCUS FOR SHOWERS AND THUNDERSTORMS /SOME WITH HEAVY
RAIN...GUSTY WINDS...FQT LIGHTNING AND EVEN SOME FAIRLY LARGE
HAIL/ WILL OCCUR ACROSS THE LOWER SUSQ VALLEY THIS EVENING...
WHILE THE FAR NW SEES SHOWERS DECREASE/MOVE OFF TO THE SOUTH AS
THE CFRONT PUSHES THROUGH THE KBFD AREA LATE THIS AFTERNOON...AND
REACHES THE CENTRAL ZONES AOB 00Z THUR. SCATTERED SHOWERS AND A
STRAY TSRA WILL LINGER ACROSS THE CENTRAL RIDGE AND VALLEY REGION
THROUGH EARLY THIS EVENING.
24-HOUR...STORM TOTAL RAINFALL WILL BE ABOUT 4-5 TENTHS OF AN
INCH...WITH THE BULK OF IT FALLING FROM JUST ONE OR TWO
THUNDERSTORMS. GIVEN THE ANOMALOUSLY HIGH PWATS OF 1.5-2 INCHES
ACROSS THE STATE...THERE IS A CHANCE FOR LOCALLY HEAVY RAINFALL OF
OVER 1 INCH.
TEMPS TONIGHT WILL STILL BE QUITE MUGGY IN THE SOUTHEAST. LOWS
WILL RANGE FROM THE UPPER 60S ACROSS THE LOWER SUSQ REGION...TO
THE MUCH MORE COMFORTABLE UPPER 50S ACROSS THE NORTHERN MTNS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
OVERALL SCENARIO REMAINS UNCHANGED IN THE LONG TERM PERIOD AS A
LARGE UPPER RIDGE BUILDING OVER THE FOUR CORNERS REGION IS
FORECAST TO EXPAND NORTH AND EAST INTO THE ROCKIES AND PLAINS
DURING THE PERIOD. DOWNSTREAM...THIS WILL LEAD TO LONG WAVE
TROFFING OVER THE EASTERN THIRD OF THE COUNTRY. UPPER LOW TO THE
EAST OF HUDSON BAY WILL BE STRENGTHENED AT TIMES BY SHORTWAVE
ENERGY IN THE STRONGER JET STREAM FLOW ACROSS CANADA. SOUTHWARD
EXTENSION OF THIS LOW/TROF WILL AT TIMES DURING THE PERIOD
STRENGTHENING THE TROFFING ACROSS THE NORTHEASTERN U.S./OUR
REGION. THE TREND OF MEDIUM RANGE MODEL GUIDANCE IS FOR
STRONGER/DEEPER TROFFING DOWNSTREAM ACROSS THE EASTERN
U.S...DEVELOPING AN ALMOST FULL LATITUDE TROF EXTENDING FROM THE
EASTERN CANADA LOW SWD TO FLORIDA. THIS WILL LIKELY SERVE TO
EXPAND AND PROLONG THE CHANCES FOR PCPN THIS WEEKEND.
GUIDANCE FORECASTS CONTINUE TO BRING A FRONT AND INCREASED
CHANGES FOR PRECIPITATION TOWARD PA IN THE WEDNESDAY/THURSDAY TIME
FRAME AND SHOW A SECOND...POTENTIALLY STRONGER SYSTEM LATE NEXT
WEEKEND. THE TREND OF STRONGER TROUGHING MENTIONED ABOVE HAS LEAD
TO SLOWER ARRIVAL AND DEPARTURE OF THE FRONTAL SYSTEM IN THE DAILY
PROGS. THE ECMWF IN LATEST RUN HAS SLOWED UP THE PROGRESSION OF
THIS UPPER LEVEL LOW...WHERE THE GFS OPERATIONAL AND ENSEMBLES
HAVE SPED UP ITS PROGRESSION THROUGH THE GREAT LAKES REGION. A
WARM FRONT WILL BE ON THE DOORSTEP OF PA SUNDAY...AS THE EC
CONTINUES TO SLOW ITS PROGRESSION SO EXPECT THE WARM FRONT TO MOVE
IN CLOSER TO MIDDAY SUNDAY. HAVE THUS ADJUSTED POPS/TIME.
ASSOCIATED COLD FRONT DOES NOT CROSS THE STATE TIL MONDAY...WHERE
SURPRISINGLY AT THIS POINT...THE EC AND GFS COME CLOSELY IN PHASE.
THIS LARGE UPPER LEVEL LOW COULD BECOME QUASI STATIONARY OVER
SOUTHERN CANADA...GREAT LAKES REGION WHICH COULD LEAD TO A
POTENTIAL PROLONGED PERIOD OF SHOWERS AND THUNDERSTORM THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AFTER A QUIET START TO THE DAY...SCT TO NMRS SHWRS AND TSTMS
WILL DEVELOP THIS AFTN INTO THE EVE ALONG AND AHEAD OF A COLD
FRONT SHIFTING SEWD FROM THE GREAT LAKES. CVRG PROJECTED TO BE
GREATEST OVER THE CNTRL AND ERN PRTNS OF THE AIRSPACE WITH SOME
STG TO MARGINALLY SVR STORMS POSSIBLE. PREVAILING CONDS WILL BE
VFR WITH BRIEF MVFR-IFR VIS REDUCTIONS IN TSRA. WND SHIFT FROM SW
TO NW BY TONIGHT WITH MAIN PCPN ACTIVITY BCMG CONFINED TO SERN
AREAS INTO THU. MVFR CIGS SEEM PROBABLE OVER WRN SXNS LATE TNGT IN
POST- FRONTAL UPSLOPE NW FLOW.
OUTLOOK...
THU...SCT TSTM IMPACTS PSBL SERN AIRFIELDS AS COLD FRONT SLOWS
ALONG THE MID-ATLC COAST.
FRI...PATCHY MORNING FOG...OTHERWISE VFR/NO SIG WX.
SAT...PATCHY MORNING FOG...OTHERWISE VFR. ISOLD PM TSTM PSBL.
SUN...TSTM IMPACTS LKLY AS WARM FRONT LIFTS NWD ACRS AIRSPACE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/CERU
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
719 AM EDT WED JUL 23 2014
.SYNOPSIS...
A COLD FRONT WILL PUSH SOUTHEAST ACROSS THE COMMONWEALTH LATE
TODAY AND TONIGHT. A REFRESHING...COOLER AND LESS HUMID AIRMASS
WILL OVERSPREAD THE COMMONWEALTH FOR THE END OF THE WEEK INTO THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK RIDGING OVER THE REGION AT THE SURFACE AND ALOFT...COMBINED
WITH VERY WARM MID LEVEL TEMPS OF 9-11C WILL KEEP CONDITIONS
MAINLY CLEAR BUT MUGGY INTO THE LATE MORNING HOURS.
CURRENT DEWPOINTS IN THE MID TO UPPER 60S ARE A FEW DEG SHY OF
THE EXPECTED MIN TEMPS AROUND SUNRISE.
CIRRUS BLOWOFF FROM A WEAKENING LINE OF SHOWERS AND THUNDERSTORMS
OVER LAKE ERIE WILL OVERSPREAD THE NW MTNS THIS MORNING...BUT
THEN DISSIPATE FOR THE MIDDAY HOURS BEFORE NEW CONVECTION
INITIATES ALONG/AHEAD OF AN APPROACHING COLD FRONT.
THE BKN LINE OF SHRA/TSRA SLIDING SE ACROSS CENTRAL LAKE ERIE ATTM
IS OVER LOCALLY COOLER AND MORE STABLE LLVLS...AND IS PROGGED BY
THE LAST FEW RUNS OF THE HRRR TO STEADILY WEAKEN...AND EVEN
DISSIPATE AS IT MOVES ONTO THE SOUTH SHORE DURING THE NEXT
FEW HOURS AND ENCOUNTERS THE VERY STRONG MID-LEVEL CAP ACROSS
NWRN PENN. 15-MINUTE LIGHTNING FREQUENCY HAS DROPPED OFF
DRAMATICALLY OVER THE PAST HOUR. STILL PAINTED CHC POPS FOR
SHOWERS OR A RUMBLE OF THUNDER ACROSS NW WARREN COUNTY AROUND 12Z
SINCE EARLIER RUNS OF THE HRRR HAD NO SIGN OF CONVECTION EVEN
REACHING THE CENTRAL WATERS OF LAKE ERIE ATTM.
A DRY START TO THE DAY AND MAINLY SUNNY SKIES ACROSS ALL BUT THE
FAR NW ZONES...WILL GIVE WAY TO INCREASING CHANCES FOR SHOWERS
AND THUNDERSTORMS THIS AFTERNOON AS LARGE SCALE FORCING INCREASES
ASSOCIATED WITH THE APPROACHING COLD FRONT.
SPC HAS MAINTAINED A /SEE TEXT/ FOR ALL OF PENN WITHIN THEIR DAY
1 CONVECTIVE OUTLOOK...WITH EASTERN NEW YORK AND NEW ENGLAND UNDER
THE GUN FOR A SLIGHT RISK OF SVR TSRA GIVEN THE BETTER COMBINATION
OF STRONGER DEEP LAYER SHEAR AND CAPE. STILL...MODERATE-HIGH SFC
BASED CAPE IN EXCESS OF 2000 J/KG...COMBINED WITH ABOUT 20 KTS OF
0-6KM BULK SHEAR SHOULD BE SUFFICIENT FOR A FEW OCCURRENCES OF
DAMAGING MICROBURSTS AND HAIL ACROSS THE CWA THIS AFTERNOON INTO
THIS EVENING.
THE LOW-LEVEL...WSW DOWNSLOPE FLOW/COMPRESSIONAL WARMING OF THE
AIRMASS AHEAD OF THE CFRONT...WILL LEAD TO THE HIGHEST TEMPS OF
THE WEEK. AFTERNOON MAX TEMPS WILL RANGE FROM THE LOWER 80S
ACROSS THE HIGH TERRAIN OF THE NORTH AND WEST...TO THE MID AND
UPPER 80S IN THE CENTRAL VALLEYS...AND LOWER 90S IN THE GREATER
YORK/HARRISBURG AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
THE FOCUS FOR SHOWERS AND THUNDERSTORMS /SOME WITH HEAVY
RAIN...GUSTY WINDS...FQT LIGHTNING AND EVEN SOME FAIRLY LARGE
HAIL/ WILL OCCUR ACROSS THE LOWER SUSQ VALLEY THIS EVENING...
WHILE THE FAR NW SEES SHOWERS DECREASE/MOVE OFF TO THE SOUTH AS
THE CFRONT PUSHES THROUGH THE KBFD AREA LATE THIS AFTERNOON...AND
REACHES THE CENTRAL ZONES AOB 00Z THUR. SCATTERED SHOWERS AND A
STRAY TSRA WILL LINGER ACROSS THE CENTRAL RIDGE AND VALLEY REGION
THROUGH EARLY THIS EVENING.
24-HOUR...STORM TOTAL RAINFALL WILL BE ABOUT 4-5 TENTHS OF AN
INCH...WITH THE BULK OF IT FALLING FROM JUST ONE OR TWO
THUNDERSTORMS. GIVEN THE ANOMALOUSLY HIGH PWATS OF 1.5-2 INCHES
ACROSS THE STATE...THERE IS A CHANCE FOR LOCALLY HEAVY RAINFALL OF
OVER 1 INCH.
TEMPS TONIGHT WILL STILL BE QUITE MUGGY IN THE SOUTHEAST. LOWS
WILL RANGE FROM THE UPPER 60S ACROSS THE LOWER SUSQ REGION...TO
THE MUCH MORE COMFORTABLE UPPER 50S ACROSS THE NORTHERN MTNS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
OVERALL SCENARIO REMAINS UNCHANGED IN THE LONG TERM PERIOD AS A
LARGE UPPER RIDGE BUILDING OVER THE FOUR CORNERS REGION IS
FORECAST TO EXPAND NORTH AND EAST INTO THE ROCKIES AND PLAINS
DURING THE PERIOD. DOWNSTREAM...THIS WILL LEAD TO LONG WAVE
TROFFING OVER THE EASTERN THIRD OF THE COUNTRY. UPPER LOW TO THE
EAST OF HUDSON BAY WILL BE STRENGTHENED AT TIMES BY SHORTWAVE
ENERGY IN THE STRONGER JET STREAM FLOW ACROSS CANADA. SOUTHWARD
EXTENSION OF THIS LOW/TROF WILL AT TIMES DURING THE PERIOD
STRENGTHENING THE TROFFING ACROSS THE NORTHEASTERN U.S./OUR
REGION. THE TREND OF MEDIUM RANGE MODEL GUIDANCE IS FOR
STRONGER/DEEPER TROFFING DOWNSTREAM ACROSS THE EASTERN
U.S...DEVELOPING AN ALMOST FULL LATITUDE TROF EXTENDING FROM THE
EASTERN CANADA LOW SWD TO FLORIDA. THIS WILL LIKELY SERVE TO
EXPAND AND PROLONG THE CHANCES FOR PCPN THIS WEEKEND.
GUIDANCE FORECASTS CONTINUE TO BRING A FRONT AND INCREASED
CHANGES FOR PRECIPITATION TOWARD PA IN THE WEDNESDAY/THURSDAY TIME
FRAME AND SHOW A SECOND...POTENTIALLY STRONGER SYSTEM LATE NEXT
WEEKEND. THE TREND OF STRONGER TROUGHING MENTIONED ABOVE HAS LEAD
TO SLOWER ARRIVAL AND DEPARTURE OF THE FRONTAL SYSTEM IN THE DAILY
PROGS. THE ECMWF IN LATEST RUN HAS SLOWED UP THE PROGRESSION OF
THIS UPPER LEVEL LOW...WHERE THE GFS OPERATIONAL AND ENSEMBLES
HAVE SPED UP ITS PROGRESSION THROUGH THE GREAT LAKES REGION. A
WARM FRONT WILL BE ON THE DOORSTEP OF PA SUNDAY...AS THE EC
CONTINUES TO SLOW ITS PROGRESSION SO EXPECT THE WARM FRONT TO MOVE
IN CLOSER TO MIDDAY SUNDAY. HAVE THUS ADJUSTED POPS/TIME.
ASSOCIATED COLD FRONT DOES NOT CROSS THE STATE TIL MONDAY...WHERE
SURPRISINGLY AT THIS POINT...THE EC AND GFS COME CLOSELY IN PHASE.
THIS LARGE UPPER LEVEL LOW COULD BECOME QUASI STATIONARY OVER
SOUTHERN CANADA...GREAT LAKES REGION WHICH COULD LEAD TO A
POTENTIAL PROLONGED PERIOD OF SHOWERS AND THUNDERSTORM THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
23/12Z...PATCHY MVFR BR/HZ WILL IMPROVE TO VFR BY 14Z. AFTER A
QUIET START TO THE DAY...EXPECT SCT TO NMRS SHWRS AND TSTMS TO
DEVELOP THIS AFTN INTO THE EVE ALONG AND AHEAD OF A COLD FRONT
SHIFTING SEWD FROM THE GREAT LAKES. CVRG PROJECTED TO BE GREATEST
OVER THE CNTRL AND ERN PRTNS OF THE AIRSPACE WITH SOME STG TO
MARGINALLY SVR STORMS POSSIBLE. PREVAILING CONDS WILL BE VFR WITH
BRIEF MVFR- IFR VIS REDUCTIONS IN TSRA. WND SHIFT FROM SW TO NW BY
TONIGHT WITH MAIN PCPN ACTIVITY BCMG CONFINED TO SERN AREAS INTO
THU. MVFR CIGS SEEM PROBABLE OVER WRN SXNS LATE TNGT IN POST-
FRONTAL UPSLOPE NW FLOW.
OUTLOOK...
THU...SCT TSTM IMPACTS PSBL SERN AIRFIELDS AS COLD FRONT SLOWS
ALONG THE MID-ATLC COAST.
FRI...PATCHY MORNING FOG...OTHERWISE VFR/NO SIG WX.
SAT...PATCHY MORNING FOG...OTHERWISE VFR. ISOLD PM TSTM PSBL.
SUN...TSTM IMPACTS LKLY AS WARM FRONT LIFTS NWD ACRS AIRSPACE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/CERU
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
554 AM EDT WED JUL 23 2014
.SYNOPSIS...
A COLD FRONT WILL PUSH SOUTHEAST ACROSS THE COMMONWEALTH LATE
TODAY AND TONIGHT. A REFRESHING...COOLER AND LESS HUMID AIRMASS
WILL OVERSPREAD THE COMMONWEALTH FOR THE END OF THE WEEK INTO THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK RIDGING OVER THE REGION AT THE SURFACE AND ALOFT...COMBINED
WITH VERY WARM MID LEVEL TEMPS OF 9-11C WILL KEEP CONDITIONS
MAINLY CLEAR BUT MUGGY INTO THE LATE MORNING HOURS.
CURRENT DEWPOINTS IN THE MID TO UPPER 60S ARE A FEW DEG SHY OF
THE EXPECTED MIN TEMPS AROUND SUNRISE.
CIRRUS BLOWOFF FROM A WEAKENING LINE OF SHOWERS AND THUNDERSTORMS
OVER LAKE ERIE WILL OVERSPREAD THE NW MTNS THIS MORNING...BUT
THEN DISSIPATE FOR THE MIDDAY HOURS BEFORE NEW CONVECTION
INITIATES ALONG/AHEAD OF AN APPROACHING COLD FRONT.
THE BKN LINE OF SHRA/TSRA SLIDING SE ACROSS CENTRAL LAKE ERIE ATTM
IS OVER LOCALLY COOLER AND MORE STABLE LLVLS...AND IS PROGGED BY
THE LAST FEW RUNS OF THE HRRR TO STEADILY WEAKEN...AND EVEN
DISSIPATE AS IT MOVES ONTO THE SOUTH SHORE DURING THE NEXT
FEW HOURS AND ENCOUNTERS THE VERY STRONG MID-LEVEL CAP ACROSS
NWRN PENN. 15-MINUTE LIGHTNING FREQUENCY HAS DROPPED OFF
DRAMATICALLY OVER THE PAST HOUR. STILL PAINTED CHC POPS FOR
SHOWERS OR A RUMBLE OF THUNDER ACROSS NW WARREN COUNTY AROUND 12Z
SINCE EARLIER RUNS OF THE HRRR HAD NO SIGN OF CONVECTION EVEN
REACHING THE CENTRAL WATERS OF LAKE ERIE ATTM.
A DRY START TO THE DAY AND MAINLY SUNNY SKIES ACROSS ALL BUT THE
FAR NW ZONES...WILL GIVE WAY TO INCREASING CHANCES FOR SHOWERS
AND THUNDERSTORMS THIS AFTERNOON AS LARGE SCALE FORCING INCREASES
ASSOCIATED WITH THE APPROACHING COLD FRONT.
SPC HAS MAINTAINED A /SEE TEXT/ FOR ALL OF PENN WITHIN THEIR DAY
1 CONVECTIVE OUTLOOK...WITH EASTERN NEW YORK AND NEW ENGLAND UNDER
THE GUN FOR A SLIGHT RISK OF SVR TSRA GIVEN THE BETTER COMBINATION
OF STRONGER DEEP LAYER SHEAR AND CAPE. STILL...MODERATE-HIGH SFC
BASED CAPE IN EXCESS OF 2000 J/KG...COMBINED WITH ABOUT 20 KTS OF
0-6KM BULK SHEAR SHOULD BE SUFFICIENT FOR A FEW OCCURRENCES OF
DAMAGING MICROBURSTS AND HAIL ACROSS THE CWA THIS AFTERNOON INTO
THIS EVENING.
THE LOW-LEVEL...WSW DOWNSLOPE FLOW/COMPRESSIONAL WARMING OF THE
AIRMASS AHEAD OF THE CFRONT...WILL LEAD TO THE HIGHEST TEMPS OF
THE WEEK. AFTERNOON MAX TEMPS WILL RANGE FROM THE LOWER 80S
ACROSS THE HIGH TERRAIN OF THE NORTH AND WEST...TO THE MID AND
UPPER 80S IN THE CENTRAL VALLEYS...AND LOWER 90S IN THE GREATER
YORK/HARRISBURG AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
THE FOCUS FOR SHOWERS AND THUNDERSTORMS /SOME WITH HEAVY
RAIN...GUSTY WINDS...FQT LIGHTNING AND EVEN SOME FAIRLY LARGE
HAIL/ WILL OCCUR ACROSS THE LOWER SUSQ VALLEY THIS EVENING...
WHILE THE FAR NW SEES SHOWERS DECREASE/MOVE OFF TO THE SOUTH AS
THE CFRONT PUSHES THROUGH THE KBFD AREA LATE THIS AFTERNOON...AND
REACHES THE CENTRAL ZONES AOB 00Z THUR. SCATTERED SHOWERS AND A
STRAY TSRA WILL LINGER ACROSS THE CENTRAL RIDGE AND VALLEY REGION
THROUGH EARLY THIS EVENING.
24-HOUR...STORM TOTAL RAINFALL WILL BE ABOUT 4-5 TENTHS OF AN
INCH...WITH THE BULK OF IT FALLING FROM JUST ONE OR TWO
THUNDERSTORMS. GIVEN THE ANOMALOUSLY HIGH PWATS OF 1.5-2 INCHES
ACROSS THE STATE...THERE IS A CHANCE FOR LOCALLY HEAVY RAINFALL OF
OVER 1 INCH.
TEMPS TONIGHT WILL STILL BE QUITE MUGGY IN THE SOUTHEAST. LOWS
WILL RANGE FROM THE UPPER 60S ACROSS THE LOWER SUSQ REGION...TO
THE MUCH MORE COMFORTABLE UPPER 50S ACROSS THE NORTHERN MTNS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
OVERALL SCENARIO REMAINS UNCHANGED IN THE LONG TERM PERIOD AS A
LARGE UPPER RIDGE BUILDING OVER THE FOUR CORNERS REGION IS
FORECAST TO EXPAND NORTH AND EAST INTO THE ROCKIES AND PLAINS
DURING THE PERIOD. DOWNSTREAM...THIS WILL LEAD TO LONG WAVE
TROFFING OVER THE EASTERN THIRD OF THE COUNTRY. UPPER LOW TO THE
EAST OF HUDSON BAY WILL BE STRENGTHENED AT TIMES BY SHORTWAVE
ENERGY IN THE STRONGER JET STREAM FLOW ACROSS CANADA. SOUTHWARD
EXTENSION OF THIS LOW/TROF WILL AT TIMES DURING THE PERIOD
STRENGTHENING THE TROFFING ACROSS THE NORTHEASTERN U.S./OUR
REGION. THE TREND OF MEDIUM RANGE MODEL GUIDANCE IS FOR
STRONGER/DEEPER TROFFING DOWNSTREAM ACROSS THE EASTERN
U.S...DEVELOPING AN ALMOST FULL LATITUDE TROF EXTENDING FROM THE
EASTERN CANADA LOW SWD TO FLORIDA. THIS WILL LIKELY SERVE TO
EXPAND AND PROLONG THE CHANCES FOR PCPN THIS WEEKEND.
GUIDANCE FORECASTS CONTINUE TO BRING A FRONT AND INCREASED
CHANGES FOR PRECIPITATION TOWARD PA IN THE WEDNESDAY/THURSDAY TIME
FRAME AND SHOW A SECOND...POTENTIALLY STRONGER SYSTEM LATE NEXT
WEEKEND. THE TREND OF STRONGER TROUGHING MENTIONED ABOVE HAS LEAD
TO SLOWER ARRIVAL AND DEPARTURE OF THE FRONTAL SYSTEM IN THE DAILY
PROGS. THE ECMWF IN LATEST RUN HAS SLOWED UP THE PROGRESSION OF
THIS UPPER LEVEL LOW...WHERE THE GFS OPERATIONAL AND ENSEMBLES
HAVE SPED UP ITS PROGRESSION THROUGH THE GREAT LAKES REGION. A
WARM FRONT WILL BE ON THE DOORSTEP OF PA SUNDAY...AS THE EC
CONTINUES TO SLOW ITS PROGRESSION SO EXPECT THE WARM FRONT TO MOVE
IN CLOSER TO MIDDAY SUNDAY. HAVE THUS ADJUSTED POPS/TIME.
ASSOCIATED COLD FRONT DOES NOT CROSS THE STATE TIL MONDAY...WHERE
SURPRISINGLY AT THIS POINT...THE EC AND GFS COME CLOSELY IN PHASE.
THIS LARGE UPPER LEVEL LOW COULD BECOME QUASI STATIONARY OVER
SOUTHERN CANADA...GREAT LAKES REGION WHICH COULD LEAD TO A
POTENTIAL PROLONGED PERIOD OF SHOWERS AND THUNDERSTORM THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
23/09Z...UPDATE...IR STLT/SFC OBS DEPICT SIGNIFICANTLY LESS FOG/ST
IMPACTING TERMINALS THAN IN RECENT MORNINGS. RADAR SHOWS LINE OF
STORMS CROSSING LK ERIE HAS WEAKENED CONSIDERABLY AS PREV FCST
BELOW. A SECOND LINE OF SCT SHOWERS RECENTLY DEVELOPED NEAR AFJ-
DUJ LINE AND SHOULD ALSO WEAKEN AS THEY APPROACH THE LAURELS BY 12Z.
23/06Z...CUT BACK ON FOG THIS MORNING GIVEN OBS TRENDS AND LGT
S-SW GRADIENT SFC WIND IN ADVANCE OF COLD FRONT SEWD ACRS LWR MI
TWD THE ERN LKS. LINE OF STORMS IN ADVANCE OF COLD FRONT MOVG ACRS
LK ERIE ARE FCST BY COSPA/HRRR/SPC 4KM WRF TO WEAKEN OR DISSIPATE
AS THEY REACH NW PA AROUND DAYBREAK.
AFTER SOMEWHAT OF A LULL IN CONVECTION DURING THE MID TO LATE
MORNING...EXPECT SCT TO NMRS SHWRS AND TSTMS TO DEVELOP FROM THIS
AFTN INTO THE EVE ALONG AND AHEAD OF THE COLD FRONT..AS IT SHIFTS
SEWD ACRS THE AIRSPACE. CVRG SHOULD BE GREATEST OVER THE CNTRL AND
ERN PRTNS OF THE AIRSPACE WITH SOME STG TO LCLY SVR STORMS
POSSIBLE. PREVAILING CONDS WILL VFR WITH BRIEF MVFR-IFR VIS
REDUCTIONS IN TSRA IMPACTS. WND SHIFT FROM SW TO NW BY TONIGHT
WITH MAIN PCPN ACTIVITY BCMG CONFINED TO SERN AREAS INTO THU.
POST-FRONTAL MVFR SEEMS PROBABLE OVER WRN SXNS TNGT.
OUTLOOK...
THU...SCT TSTM IMPACTS PSBL SERN AIRFIELDS AS COLD FRONT SLOWS
ALONG THE MID-ATLC COAST.
FRI...PATCHY MORNING FOG...OTHERWISE VFR/NO SIG WX.
SAT...PATCHY MORNING FOG...OTHERWISE VFR. ISOLD PM TSTM PSBL.
SUN...TSTM IMPACTS LKLY AS WARM FRONT LIFTS NWD ACRS AIRSPACE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/CERU
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
537 AM EDT WED JUL 23 2014
.SYNOPSIS...
A COLD FRONT WILL PUSH SOUTHEAST ACROSS THE COMMONWEALTH LATE
TODAY AND TONIGHT. A REFRESHING...COOLER AND LESS HUMID AIRMASS
WILL OVERSPREAD THE COMMONWEALTH FOR THE END OF THE WEEK INTO THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK RIDGING OVER THE REGION AT THE SURFACE AND ALOFT...COMBINED
WITH VERY WARM MID LEVEL TEMPS OF 9-11C WILL KEEP CONDITIONS
MAINLY CLEAR BUT MUGGY INTO THE LATE MORNING HOURS.
CURRENT DEWPOINTS IN THE MID TO UPPER 60S ARE A FEW DEG SHY OF
THE EXPECTED MIN TEMPS AROUND SUNRISE.
CIRRUS BLOWOFF FROM A WEAKENING LINE OF SHOWERS AND THUNDERSTORMS
OVER LAKE ERIE WILL OVERSPREAD THE NW MTNS THIS MORNING...BUT
THEN DISSIPATE FOR THE MIDDAY HOURS BEFORE NEW CONVECTION
INITIATES ALONG/AHEAD OF AN APPROACHING COLD FRONT.
THE BKN LINE OF SHRA/TSRA SLIDING SE ACROSS CENTRAL LAKE ERIE ATTM
IS OVER LOCALLY COOLER AND MORE STABLE LLVLS...AND IS PROGGED BY
THE LAST FEW RUNS OF THE HRRR TO STEADILY WEAKEN...AND EVEN
DISSIPATE AS IT MOVES ONTO THE SOUTH SHORE DURING THE NEXT
FEW HOURS AND ENCOUNTERS THE VERY STRONG MID-LEVEL CAP ACROSS
NWRN PENN. 15-MINUTE LIGHTNING FREQUENCY HAS DROPPED OFF
DRAMATICALLY OVER THE PAST HOUR. STILL PAINTED CHC POPS FOR
SHOWERS OR A RUMBLE OF THUNDER ACROSS NW WARREN COUNTY AROUND 12Z
SINCE EARLIER RUNS OF THE HRRR HAD NO SIGN OF CONVECTION EVEN
REACHING THE CENTRAL WATERS OF LAKE ERIE ATTM.
A DRY START TO THE DAY AND MAINLY SUNNY SKIES ACROSS ALL BUT THE
FAR NW ZONES...WILL GIVE WAY TO INCREASING CHANCES FOR SHOWERS
AND THUNDERSTORMS THIS AFTERNOON AS LARGE SCALE FORCING INCREASES
ASSOCIATED WITH THE APPROACHING COLD FRONT.
SPC HAS MAINTAINED A /SEE TEXT/ FOR ALL OF PENN WITHIN THEIR DAY
1 CONVECTIVE OUTLOOK...WITH EASTERN NEW YORK AND NEW ENGLAND UNDER
THE GUN FOR A SLIGHT RISK OF SVR TSRA GIVEN THE BETTER COMBINATION
OF STRONGER DEEP LAYER SHEAR AND CAPE. STILL...MODERATE-HIGH SFC
BASED CAPE IN EXCESS OF 2000 J/KG...COMBINED WITH ABOUT 20 KTS OF
0-6KM BULK SHEAR SHOULD BE SUFFICIENT FOR A FEW OCCURENCES OF
DAMAGING MICROBURSTS AND HAIL ACROSS THE CWA THIS AFTERNOON INTO
THIS EVENING.
THE LOW-LEVEL...WSW DOWNSLOPE FLOW/COMPRESSIONAL WARMING OF THE
AIRMASS AHEAD OF THE CFRONT...WILL LEAD TO THE HIGHEST TEMPS OF
THE WEEK. AFTERNOON MAX TEMPS WILL RANGE FROM THE LOWER 80S
ACROSS THE HIGH TERRAIN OF THE NORTH AND WEST...TO THE MID AND
UPPER 80S IN THE CENTRAL VALLEYS...AND LOWER 90S IN THE GREATER
YORK/HARRISBURG AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
THE FOCUS FOR SHOWERS AND THUNDERSTORMS /SOME WITH HEAVY
RAIN...GUSTY WINDS...FQT LIGHTNING AND EVEN SOME FAIRLY LARGE
HAIL/ WILL OCCUR ACROSS THE LOWER SUSQ VALLEY THIS EVENING...
WHILE THE FAR NW SEES SHOWERS DECREASE/MOVE OFF TO THE SOUTH AS
THE CFRONT PUSHES THROUGH THE KBFD AREA LATE THIS AFTERNOON...AND
REACHES THE CENTRAL ZONES AOB 00Z THUR. SCATTERED SHOWERS AND A
STRAY TSRA WILL LINGER ACROSS THE CENTRAL RIDGE AND VALLEY REGION
THROUGH EARLY THIS EVENING.
24-HOUR...STORM TOTAL RAINFALL WILL BE ABOUT 4-5 TENTHS OF AN
INCH...WITH THE BULK OF IT FALLING FROM JUST ONE OR TWO
THUNDERSTORMS. GIVEN THE ANOMALOUSLY HIGH PWATS OF 1.5-2 INCHES
ACROSS THE STATE...THERE IS A CHANCE FOR LOCALLY HEAVY RANFALL OF
OVER 1 INCH.
TEMPS TONIGHT WILL STILL BE QUITE MUGGY IN THE SOUTHEAST. LOWS
WILL RANGE FROM THE UPPER 60S ACROSS THE LOWER SUSQ REGION...TO
THE MUCH MORE COMFORTABLE UPPER 50S ACROSS THE NORTHERN MTNS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
OVERALL SCENARIO REMAINS UNCHANGED IN THE LONG TERM PERIOD AS A
LARGE UPPER RIDGE BUILDING OVER THE FOUR CORNERS REGION IS
FORECAST TO EXPAND NORTH AND EAST INTO THE ROCKIES AND PLAINS
DURING THE PERIOD. DOWNSTREAM...THIS WILL LEAD TO LONG WAVE
TROFFING OVER THE EASTERN THIRD OF THE COUNTRY. UPPER LOW TO THE
EAST OF HUDSON BAY WILL BE STRENGTHENED AT TIMES BY SHORTWAVE
ENERGY IN THE STRONGER JET STREAM FLOW ACROSS CANADA. SOUTHWARD
EXTENSION OF THIS LOW/TROF WILL AT TIMES DURING THE PERIOD
STRENGTHENING THE TROFFING ACROSS THE NORTHEASTERN U.S./OUR
REGION. THE TREND OF MEDIUM RANGE MODEL GUIDANCE IS FOR
STRONGER/DEEPER TROFFING DOWNSTREAM ACROSS THE EASTERN
U.S...DEVELOPING AN ALMOST FULL LATITUDE TROF EXTENDING FROM THE
EASTERN CANADA LOW SWD TO FLORIDA. THIS WILL LIKELY SERVE TO
EXPAND AND PROLONG THE CHANCES FOR PCPN THIS WEEKEND.
GUIDANCE FORECASTS CONTINUE TO BRING A FRONT AND INCREASED
CHANGES FOR PRECIPITATION TOWARD PA IN THE WEDNESDAY/THURSDAY TIME
FRAME AND SHOW A SECOND...POTENTIALLY STRONGER SYSTEM LATE NEXT
WEEKEND. THE TREND OF STRONGER TROUGHING MENTIONED ABOVE HAS LEAD
TO SLOWER ARRIVAL AND DEPARTURE OF THE FRONTAL SYSTEM IN THE DAILY
PROGS. THE ECMWF IN LATEST RUN HAS SLOWED UP THE PROGRESSION OF
THIS UPPER LEVEL LOW...WHERE THE GFS OPERATIONAL AND ENSEMBLES
HAVE SPED UP ITS PROGRESSION THROUGH THE GREAT LAKES REGION. A
WARM FRONT WILL BE ON THE DOORSTEP OF PA SUNDAY...AS THE EC
CONTINUES TO SLOW ITS PROGRESSION SO EXPECT THE WARM FRONT TO MOVE
IN CLOSER TO MIDDAY SUNDAY. HAVE THUS ADJUSTED POPS/TIME.
ASSOCIATED COLD FRONT DOES NOT CROSS THE STATE TIL MONDAY...WHERE
SURPRISINGLY AT THIS POINT...THE EC AND GFS COME CLOSELY IN PHASE.
THIS LARGE UPPER LEVEL LOW COULD BECOME QUASI STATIONARY OVER
SOUTHERN CANADA...GREAT LAKES REGION WHICH COULD LEAD TO A
POTENTIAL PROLONGED PERIOD OF SHOWERS AND THUNDERSTORM THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
23/06Z...CUT BACK ON FOG THIS MORNING GIVEN OBS TRENDS AND LGT
S-SW GRADIENT SFC WIND IN ADVANCE OF COLD FRONT SEWD ACRS LWR MI
TWD THE ERN LKS. LINE OF STORMS IN ADVANCE OF COLD FRONT MOVG ACRS
LK ERIE ARE FCST BY COSPA/HRRR/SPC 4KM WRF TO WEAKEN OR DISSIPATE
AS THEY REACH NW PA AROUND DAYBREAK.
AFTER SOMEWHAT OF A LULL IN CONVECTION DURING THE MID TO LATE
MORNING...EXPECT SCT TO NMRS SHWRS AND TSTMS TO DEVELOP FROM THIS
AFTN INTO THE EVE ALONG AND AHEAD OF THE COLD FRONT..AS IT SHIFTS
SEWD ACRS THE AIRSPACE. CVRG SHOULD BE GREATEST OVER THE CNTRL AND
ERN PRTNS OF THE AIRSPACE WITH SOME STG TO LCLY SVR STORMS
POSSIBLE. PREVAILING CONDS WILL VFR WITH BRIEF MVFR-IFR VIS
REDUCTIONS IN TSRA IMPACTS. WND SHIFT FROM SW TO NW BY TONIGHT
WITH MAIN PCPN ACTIVITY BCMG CONFINED TO SERN AREAS INTO THU.
POST-FRONTAL MVFR SEEMS PROBABLE OVER WRN SXNS TNGT.
OUTLOOK...
THU...SCT TSTM IMPACTS PSBL SERN AIRFIELDS AS COLD FRONT SLOWS
ALONG THE MID-ATLC COAST.
FRI...PATCHY MORNING FOG...OTHERWISE VFR/NO SIG WX.
SAT...PATCHY MORNING FOG...OTHERWISE VFR. ISOLD PM TSTM PSBL.
SUN...TSTM IMPACTS LKLY AS WARM FRONT LIFTS NWD ACRS AIRSPACE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/CERU
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
508 PM EDT WED JUL 23 2014
.SYNOPSIS...
WEAK HIGH PRESSURE ATOP THE REGION WILL GIVE WAY TO A SURFACE FRONT
APPROACHING FROM THE NORTHWEST TONIGHT. THE FRONT IS EXPECTED TO
MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THURSDAY AFTERNOON AND
EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR FRIDAY AND
THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON MONDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AT 450 PM EDT...COVERAGE HAS EXPANDED EAST OF THE BLUE RIDGE TO
WARRANT BRIEF CATEGORICAL POP VALUES ACROSS THE NC FOOTHILLS BACK TO
THE IMMEDIATE ESCARPMENT AREAS. OUTFLOWS MAY DRIVE ADDITIONAL
CONVECTION FARTHER S INTO THE SRN FOOTHILLS AND PIEDMONT...SO CHC
POPS HAVE BEEN RAMPED UP THERE AS WELL THROUGH 7 PM. STILL
ANTICIPATE THAT THE STRONGEST STORMS WILL BE MAINLY MARGINAL FOR
SEVERE WIND AND HAIL AS DCAPE VALUES ARE NOT VERY HIGH IN THE BEST
COVERAGE AREAS AND THE PROFILES ARE QUITE WARM WITH FREEZING LEVELS
ABOVE 15 KFT. THE CONVECTION SHOULD WANE QUICKLY WITH THE LOSS OF
HEATING THIS EVENING...SO WILL LOWER POPS QUICKLY IN THE 23Z TO 02Z
TIMEFRAME.
AN UPPER TROUGH IS STILL FORECAST TO BECOME ESTABLISHED ACROSS THE
EASTERN U.S. ON THU AS A STRONG SHORT MOVES THROUGH THE GREAT LAKES.
THE ASSOCIATED SURFACE COLD FRONT CURRENTLY OVER OHIO VALLEY WILL
PUSH SOUTHEAST TO JUST NW OF THE NC MOUNTAINS BY 12Z THU....AND THEN
MOVE ACROSS THE REGION ON THU. WILL CONTINUE WITH THE IDEA THAT SOME
SHOWERS/THUNDERSTORMS COULD REACH THE MOUNTAINS BY SUNRISE.
GUIDANCE IS IN AGREEMENT THAT THE FRONT SHOULD BE ACCOMPANIED BY
NUMEROUS SHOWERS AND THUNDERSTORMS...EVEN OUTSIDE THE MOUNTAINS
WHERE WINDS THROUGH THE VERTICAL PROFILE ARE WESTERLY/DOWNSLOPE IN
NATURE. WILL BUY INTO THE HIGH POPS BEING ADVERTISED AS THE
SURFACE CONVERGENCE ALONG THE FRONT COMBINED WITH THE DIGGING UPPER
TROUGH/FALLING HEIGHTS WILL TAP INTO CAPES POOLING TO BETWEEN 1000-2000J
DURING THE AFTERNOON. SPC IS STILL JUST HIGHLIGHTING THE I-77
CORRIDOR EASTWARD WITH A 5% SEVERE THREAT ON THURSDAY. WITH
IMPROVING SHEAR...WOULD NOT BE SURPRISED TO SEE A FEW SEVERE STORMS
THURSDAY AFTERNOON. MAX TEMPS ON THU WILL BE TEMPERED BY CLOUDS AND
CONVECTION SO THEY SHOULD BE A COUPLE DEGREES LOWER THAN TODAY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 200 PM WED...COLD FRONT WILL CONTINUE TO PUSH THRU THE PIEDMONT
THURSDAY EVENING...WITH AXIS OF DEEP UPPER TROUGH MOVING THRU EARLY
FRI. POPS WILL DECLINE EAST OF THE MTNS FOLLOWING THE END OF
HEATING...WITH LLVL CONVERGENCE UNLIKELY TO OVERCOME THE INHIBITION
RESULTING FROM POOR LAPSE RATES ABOVE THE PBL. PROFILES FROM THE
HIGHER TERRAIN HOWEVER DO SHOW THE EFFECTS OF MIDLEVEL CAA FOLLOWING
THE FRONT...THUS A SCHC POP IS KEPT INTO EARLY FRI MRNG. GOING
FORWARD HOWEVER...HIGH PRESSURE EXPANDS OUT OF THE MIDWEST WHICH
SHOULD PROVIDE AT LEAST A WEAK SUBSIDENCE INVERSION TO CAP OFF MOST
DEEP CONVECTION FRI AND SAT. THE NAM AND A PORTION OF THE SREF
MEMBERS DO NOT SHOW THE INVERSION BEING STRONG ENOUGH TO KEEP THE
ENTIRE CWFA DRY DURING THIS TIME. WILL ADVERTISE SCHC POPS OVER THE
BLUE RIDGE FRI AS WELL AS IN THE LOWER PIEDMONT...WELL SE OF
I-85...WHERE THE HIGH WILL HAVE THE LEAST INFLUENCE. THERE IS BETTER
CONSENSUS FOR A DRY FCST SATURDAY...THOUGH BY THAT TIME THE HIGH HAS
BECOME INDISTINCT DUE TO THE UPPER FLOW BECOMING NEARLY ZONAL. POPS
THUS COULD BE EASILY REINTRODUCED FOR SAT IN SUBSEQUENT FCST
PACKAGES. TEMPS DURING THE SHORT RANGE WILL RETURN TO NEAR NORMAL AS
THICKNESS VALUES INCREASE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 1215 PM WEDNESDAY...DURING THE LATTER HALF OF THE UPCOMING
WEEKEND...DIURNALLY ENHANCED TSTM ACTIVITY HAS THE OPPORTUNITY TO
BECOME CONSIDERABLE ON SUNDAY WITHIN DEVELOPING LLVL RETURN FLOW
REGIME UNDERNEATH PROGRESSIVELY LOWERING UPPER HEIGHTS. L/WV TROUGH
AXIS IS PROGGED TO CONTINUE TO DIG INTO THE SE CONUS THROUGH
MONDAY...EVENTUALLY FORCING A COLD FRONT ACRS THE REGION BY MONDAY
NIGHT. WITH PRONOUNCED UPPER LEVEL TROUGH ACRS THE ERN CONUS AND
A CONTINENTAL AIRMASS OVERSPREADING THE REGION...A NOTABLY DRY AND
COOLER FCST IS ON TAP FOR TUESDAY AND WEDNESDAY.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...ALL CONVECTION THIS AFTN HAS THUS FAR REMAINED WELL NW OR
S OF THE AIRFIELD...AND THE LATEST HRRR RUN STILL DOES NOT SHOW MUCH
CONVECTIVE DEVELOPMENT IN IMMEDIATE AREA LATE THIS AFTERNOON. ..SO
WILL CONTINUE THE VCSH MENTION FOR NOW UNLESS ANY TS GETS CLOSER
THROUGH 00Z. OTHERWISE...THE NIGHT AND EARLY MORNING SHOULD BE QUIET
AND VFR. THE APPROACH OF A COLD FRONT ON THU WARRANTS A PROB30 FOR
TSRA AT THE END OF THE TAF PERIOD.
ELSEWHERE...FAIRLY SOLID COVERAGE HAS DEVELOPED FROM KAVL TO
KHKY...AND ALSO NEARING KGMU TO KGSP ON A SWD MOVING OUTFLOW. THESE
SITES WILL GET TEMPO TSRA THROUGH LATE AFTN...WITH JUST VCTS
MENTIONED AT KAND. OTHERWISE...THE NIGHT SHOULD BE QUIET AND VFR.
THE EXCEPTION IS AT KAVL WHERE LIFR FOG WILL BE IN THE FORECAST
AGAIN FOR EARLY THU. AN APPROACH OF A COLD FRONT ON THU WARRANTS
PROB30 TSRA FOR THE END OF THE TAF PERIOD AT ALL SITES.
OUTLOOK... SHOWERS AND THUNDERSTORMS WILL END THURSDAY EVENING AS A
COLD FRONT MOVES SOUTHEAST OF THE AREA. FRIDAY AND SAT SHOULD BE
QUIET AND VFR...THE EXCEPTION WILL BE THE MOUNTAIN VALLEYS WHERE
EARLY MORNING FOG MAY OCCUR. THUNDERSTORMS WILL RETURN TO THE
FORECAST FOR SUNDAY AFTERNOON THROUGH MONDAY AS ANOTHER COLD FRONT
APPROACHES AND THEN MOVES THROUGH THE AREA ON MONDAY.
CONFIDENCE TABLE...
21-03Z 03-09Z 09-15Z 15-21Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 93%
KAVL HIGH 98% HIGH 94% MED 75% HIGH 85%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 93%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 93%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...CSH
NEAR TERM...HG/LG
SHORT TERM...WIMBERLEY
LONG TERM...CSH
AVIATION...HG/LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
235 PM EDT WED JUL 23 2014
.SYNOPSIS...
WEAK HIGH PRESSURE ATOP THE REGION WILL GIVE WAY TO A SURFACE FRONT
APPROACHING FROM THE NORTHWEST TONIGHT. THE FRONT IS EXPECTED TO
MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THURSDAY AFTERNOON AND
EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR FRIDAY AND
THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON MONDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AT 215 PM...CURRENT RADAR SHOWS THAT THE BEST COVERAGE OF SHOWERS
AND THUNDERSTORMS WAS ALONG THE BLUE RIDGE WITH ONLY ISOLATED
SHOWERS OUTSIDE THE MOUNTAINS. HOWEVER...THE SPC MESO-ANAL SHOWS
SBCAPES ANYWHERE FROM 1500-2000J WITH NO CIN INDICATED.
THEREFORE...SOME SCT TSRA SHOULD DEVELOP IN THE VICINITY OF THE WEAK
LEE TROUGH IN THE MID TO LATE AFTERNOON HOURS...SO WILL CONTINUE THE
FORECAST OF SCATTERED SHOWERS/THUNDERSTORMS. CONVECTION SHOULD WANE
QUICKLY WITH THE LOSS OF HEATING THIS EVENING...SO WILL LOWER POPS
QUICKLY IN THE 23Z-02Z TIMEFRAME.
AN UPPER TROUGH IS STILL FORECAST TO BECOME ESTABLISHED ACROSS THE
EASTERN U.S. ON THU AS A STRONG SHORT MOVES THROUGH THE GREAT LAKES.
THE ASSOCIATED SURFACE COLD FRONT CURRENTLY OVER OHIO VALLEY WILL
PUSH SOUTHEAST TO JUST NW OF THE NC MOUNTAINS BY 12Z THU....AND THEN
MOVE ACROSS THE REGION ON THU. WILL CONTINUE WITH THE IDEA THAT SOME
SHOWERS/THUNDERSTORMS COULD REACH THE MOUNTAINS BY SUNRISE.
GUIDANCE IS IN AGREEMENT THAT THE FRONT SHOULD BE ACCOMPANIED BY
NUMEROUS SHOWERS AND THUNDERSTORMS...EVEN OUTSIDE THE MOUNTAINS
WHERE WINDS THROUGH THE VERTICAL PROFILE ARE WESTERLY/DOWNSLOPE IN
NATURE. WILL BUY INTO THE HIGH POPS BEING ADVERTISED AS THE
SURFACE CONVERGENCE ALONG THE FRONT COMBINED WITH THE DIGGING
UPPER TROUGH/FALLING HEIGHTS WILL TAP INTO CAPES POOLING TO
BETWEEN 1000-2000J DURING THE AFTERNOON. SPC IS STILL JUST
HIGHLIGHTING THE I-77 CORRIDOR EASTWARD WITH A 5% SEVERE THREAT ON
THURSDAY. WITH IMPROVING SHEAR...WOULD NOT BE SURPRISED TO SEE A
FEW SEVERE STORMS THURSDAY AFTERNOON. MAX TEMPS ON THU WILL BE
TEMPERED BY CLOUDS AND CONVECTION SO THEY SHOULD BE A COUPLE
DEGREES LOWER THAN TODAY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 200 PM WED...COLD FRONT WILL CONTINUE TO PUSH THRU THE PIEDMONT
THURSDAY EVENING...WITH AXIS OF DEEP UPPER TROUGH MOVING THRU EARLY
FRI. POPS WILL DECLINE EAST OF THE MTNS FOLLOWING THE END OF
HEATING...WITH LLVL CONVERGENCE UNLIKELY TO OVERCOME THE INHIBITION
RESULTING FROM POOR LAPSE RATES ABOVE THE PBL. PROFILES FROM THE
HIGHER TERRAIN HOWEVER DO SHOW THE EFFECTS OF MIDLEVEL CAA FOLLOWING
THE FRONT...THUS A SCHC POP IS KEPT INTO EARLY FRI MRNG. GOING
FORWARD HOWEVER...HIGH PRESSURE EXPANDS OUT OF THE MIDWEST WHICH
SHOULD PROVIDE AT LEAST A WEAK SUBSIDENCE INVERSION TO CAP OFF MOST
DEEP CONVECTION FRI AND SAT. THE NAM AND A PORTION OF THE SREF
MEMBERS DO NOT SHOW THE INVERSION BEING STRONG ENOUGH TO KEEP THE
ENTIRE CWFA DRY DURING THIS TIME. WILL ADVERTISE SCHC POPS OVER THE
BLUE RIDGE FRI AS WELL AS IN THE LOWER PIEDMONT...WELL SE OF
I-85...WHERE THE HIGH WILL HAVE THE LEAST INFLUENCE. THERE IS BETTER
CONSENSUS FOR A DRY FCST SATURDAY...THOUGH BY THAT TIME THE HIGH HAS
BECOME INDISTINCT DUE TO THE UPPER FLOW BECOMING NEARLY ZONAL. POPS
THUS COULD BE EASILY REINTRODUCED FOR SAT IN SUBSEQUENT FCST
PACKAGES. TEMPS DURING THE SHORT RANGE WILL RETURN TO NEAR NORMAL AS
THICKNESS VALUES INCREASE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF 1215 PM WEDNESDAY...DURING THE LATTER HALF OF THE UPCOMING
WEEKEND...DIURNALLY ENHANCED TSTM ACTIVITY HAS THE OPPORTUNITY TO
BECOME CONSIDERABLE ON SUNDAY WITHIN DEVELOPING LLVL RETURN FLOW
REGIME UNDERNEATH PROGRESSIVELY LOWERING UPPER HEIGHTS. L/WV TROUGH
AXIS IS PROGGED TO CONTINUE TO DIG INTO THE SE CONUS THROUGH
MONDAY...EVENTUALLY FORCING A COLD FRONT ACRS THE REGION BY MONDAY
NIGHT. WITH PRONOUNCED UPPER LEVEL TROUGH ACRS THE ERN CONUS AND
A CONTINENTAL AIRMASS OVERSPREADING THE REGION...A NOTABLY DRY AND
COOLER FCST IS ON TAP FOR TUESDAY AND WEDNESDAY.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...MAIN CONCERN IN THE FORECAST IS WHETHER A THUNDERSTORM
WILL AFFECT THE AIRFIELD THIS AFTERNOON. LATEST HRRR RUN DOES NOT
SHOW MUCH CONVECTIVE DEVELOPMENT IN TEH CLT AREA THIS AFTERNOON.
HENCE...WILL STAY THE COURSE WITH JUST A VCSH 20-23Z WHICH SHOULD BE
THE WINDOW FOR THE BEST COVERAGE AROUND THE AIRPORT. OTHERWISE THE
NIGHT AND EARLY MORNIGN SHOULD BE QUIET AND VFR. THE APPROACH OF A
COLD FRONT ON THU WARRANTS A PROB30 FOR TSRA AT THE END OF THE TAF
PERIOD.
ELSEWHERE...THE ONLY TAF SITE IN WHICH CONFIDENCE IS HIGH ENOUGH TO
CARRY TEMPO TSRA IS AT KAVL THIS AFTERNOON. WILL JUST MENTION A VCTS
AT OTHER AIR FIELDS. OTHERWISE...THE NIGHT SHOULD BE QUIET AND VFR.
THE EXCEPTION IS AT KAVL WHERE LIFR FOG WILL BE IN THE FORECAST
AGAIN FOR EARLY THU. AN APPROACH OF A COLD FRONT ON THU WARRANTS
PROB30 TSRA FOR THE END OF THE TAF PERIOD AT ALL SITES.
OUTLOOK... SHOWERS AND THUNDERSTORMS WILL END THURSDAY EVENING AS A
COLD FRONT MOVES SOUTHEAST OF THE AREA. FRIDAY AND SAT SHOULD BE
QUIET AND VFR...THE EXCEPTION WILL BE THE MOUNTAIN VALLEYS WHERE
EARLY MORNING FOG MAY OCCUR. THUNDERSTORMS WILL RETURN TO THE
FORECAST FOR SUNDAY AFTERNOON THROUGH MONDAY AS ANOTHER COLD FRONT
APPROACHES AND THEN MOVES THROUGH THE AREA ON MONDAY.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 98% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 92% HIGH 100% MED 76% HIGH 84%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...CSH
NEAR TERM...LG
SHORT TERM...WIMBERLEY
LONG TERM...CSH
AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
148 PM EDT WED JUL 23 2014
.SYNOPSIS...
WEAK HIGH PRESSURE ATOP THE REGION WILL GIVE WAY TO A SURFACE FRONT
APPROACHING FROM THE NORTHWEST TONIGHT. THE FRONT IS EXPECTED TO
MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THURSDAY AFTERNOON AND
EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR FRIDAY AND
THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT NOON EDT...RADAR SHOWS NUMEROUS SHOWERS DEVELOPING OVER THE
MOUNTAINS...SO THE IDEA OF HIGHER POPS OVER THE TERRAIN IS WORKING
OUT. THE LATEST HRRR IS SHOWING A BIT MORE CONVECTIVE COVERAGE OVER
THE FOOTHILLS AND PIEDMONT THIS AFTERNOON WHICH ISN`T SURPRISING
SINCE CAPES HAVE INCREASED TO 1500-2000J. HOWEVER...COVERAGE SHOULD
STILL BE SCATTERED IN NATURE. THEREFORE...ADJUSTED POPS PER CURRENT
TRENDS FOR THE AFTERNOON. ALSO MADE SOME MINOR ADJUSTMENTS TO OTHER
GRID FIELDS BASED ON CURRENT OBS AND LATEST CONSHORT RUN.
AS OF 1015 AM...SEE NO REASON BASED ON CURRENT TRENDS AND CAMS TO
DEVIATE MUCH FROM THE OFFICIAL GRIDS. BASED ON OUR CAMPOP AND TCU
DEVLOPING PER SAT PICS...I DID BUMP UP THE POPS IN THE NC CENTRAL
AND SW MOUNTAINS TO SOLID LIKELY THIS AFTERNOON. OTHERWISE...
CONVECTIVE DEVELOPMENT SHOULD BE SCATTERED. TEMPS ARE CURRENTLY
RISING RAPIDLY SO UPPER 80S STILL LOOKS GOOD FOR MAX TEMPS.
AS OF 6 AM...LATEST 11U-3.9U SATELLITE IMAGES INDICATED AN EXPANDING
AREA OF LOW CLOUDS ACROSS THE PIEDMONT AND WEST TO THE SOUTHERN NC
FOOTHILLS. SFC OBSERVATIONS SHOW A WIDE RANGE OF
VISIBILITIES...RANGING FROM M1/4SM AT KMRN TO 10SM ACROSS THE
GREENVILLE/SPARTANBURG/ANDERSON AREAS. THE LOWEST VISIBILITIES ARE
GENERALLY ACROSS THE I-77 CORRIDOR AND WITHIN THE MTN VALLEYS. ALL
PREFERRED GUIDANCE INDICATES THAT THE FOG WILL DISSIPATE DURING THE
TWO HOURS FOLLOWING SUNRISE. I WILL UPDATE THE FORECAST TO ADJUST
FOG AND VISIBILITIES TO THE LATEST OBSERVATIONS AND THINKING. IN
ADDITION...LATEST MOS HAS TRENDED WARMER FOR THIS AFTERNOON...I WILL
WARM FORECAST HIGHS A CLICK. OTHERWISE...THE CURRENT FORECAST IS IN
GOOD SHAPE.
AS OF 320 AM...EARLY MORNING FOG IS EXPECTED TO DEVELOP AND EXPAND
ACROSS THE I-77 CORRDIOR AND WITHIN THE MTN VALLEYS. THE HRRR
CONDENSATION PRESSURE DEFICITS INDICATES THAT THE LOWEST VALUES
WILL EXIST ACROSS THE SOUTHEASTERN HALF OF THE CHARLOTTE METRO AREAS
AND WITHIN THE MTN VALLEYS. FOG SHOULD DISSIPATE DURING THE FIRST
TWO HOURS OF SUNLIGHT. IN ADDITION...EARLY MIXING SHOULD YIELD A
LIGHT SOUTHWEST WIND. GREATER INSOLATION AND SOUTHWEST WINDS SHOULD
RESULT IN STEADILY WARMING TEMPERATURES FROM SUNRISE TO MID
AFTERNOON. I WILL FORECAST HIGHS TO RANGE FROM THE L80S WITHIN THE
MTNS VALLEYS TO U80S TO NEAR 90 EAST OF I-85.
RECENT W/V LOOP INDICATED THAT THE MID LEVEL LOW WAS DRIFTING WEST
ACROSS THE MISSISSIPPI RIVER DELTA...AS ANOTHER TROUGH WILL DIGGING
OVER THE OHIO RIVER VALLEY. AT THE SFC...A WEAK LEE TROUGH MAY
DEVELOP ACROSS THE PIEDMONT DURING THE AFTERNOON. A COLD FRONT WILL
APPROACH FROM THE NW TODAY...REACHING THE SOUTHERN APPALACHIANS LATE
TONIGHT. CAMS INDICATE THAT SHRA AND TSRA WILL FAVOR THE MTNS AND
ADJACENT FOOTHILLS AS EARLY AS MID MORNING TODAY. COVERAGE WILL
INCREASE THROUGH THE HEAT OF THE AFTERNOON...BECOMING SCT ACROSS THE
PIEDMONT. CONVECTION SHOULD GENERALLY DISSIPATE EAST OF THE MTNS ONE
TO TWO HOURS AFTER SUNSET. HOWEVER...I WILL MAINTAIN CHC TO LIKELY
POPS ACROSS THE TN BORDER COUNTIES TO COVER THE ARRIVAL OF PRE
FRONTAL CONVECTION. LOW TEMPERATURES TONIGHT ARE FORECAST TO RANGE
FROM THE MID 60S ACROSS THE MTNS TO LOW 70S EAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM EDT WEDNESDAY...THE MODEL GUIDANCE HAS COME INTO BETTER
AGREEMENT WITH THE PASSAGE OF A SURFACE FRONT MORE OR LESS DURING
PEAK HEATING ON THURSDAY. THE FRONT WILL BE DRIVEN ACROSS THE FCST
AREA BY A FAIRLY STRONG SHORT WAVE IN THE PRESENCE OF SOME UPPER
DIVERGENCE IN THE ENTRANCE REGION OF THE JET OVER THE NORTHEAST.
PLENTY OF LOW LEVEL MOISTURE WILL REMAIN AHEAD OF THE FRONT AS WELL.
THUS...WITH THE TIMING A BIT MORE IN FOCUS...FEEL IT APPROPRIATE TO
BUMP THE PRECIP PROBABILITY UP INTO THE LIKELY RANGE ACROSS THE
ENTIRE FCST AREA IN THE AFTERNOON. MIGHT BE A BIT TOO EARLY TO TALK
TOO MUCH ABOUT SEVERE WEATHER POTENTIAL...BUT THE FRONT SHOULD FOCUS
STORMS IN AN AIR MASS WITH 1500-2500 J/KG OF CAPE...SO THE DAY2
OUTLOOK SEEMS APPROPRIATE. SUSPECT WE WILL HAVE TO CONTEND WITH
SEVERAL SEVERE THUNDERSTORMS. THE FRONT WILL DROP SE DURING THE
EVENING HOURS ENDING THE PRECIP CHANCE BY THE EARLY MORNING HOURS ON
FRIDAY.
BEHIND THE FRONT...THE AIR MASS WILL NOT REALLY BE MUCH COOLER...BUT
IT SHOULD BE A BIT DRIER ON FRIDAY. HIGH PRESSURE SHOULD MOVE IN
DURING THE DAY. NOT REALLY SEEING MUCH TO SUPPORT ANY SHOWERS IN THE
AFTERNOON SO THE PRECIP CHANCES WERE LOWERED. FRIDAY NIGHT SHOULD BE
DRY AS WELL WITH SEASONAL TEMPS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 1215 PM WEDNESDAY...DURING THE LATTER HALF OF THE UPCOMING
WEEKEND...DIURNALLY ENHANCED TSTM ACTIVITY HAS THE OPPORTUNITY TO
BECOME CONSIDERABLE ON SUNDAY WITHIN DEVELOPING LLVL RETURN FLOW
REGIME UNDERNEATH PROGRESSIVELY LOWERING UPPER HEIGHTS. L/WV TROUGH
AXIS IS PROGGED TO CONTINUE TO DIG INTO THE SE CONUS THROUGH
MONDAY...EVENTUALLY FORCING A COLD FRONT ACRS THE REGION BY MONDAY
NIGHT. WITH PRONOUNCED UPPER LEVEL TROUGH ACRS THE ERN CONUS AND
A CONTINENTAL AIRMASS OVERSPREADING THE REGION...A NOTABLY DRY AND
COOLER FCST IS ON TAP FOR TUESDAY AND WEDNESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...MAIN CONCERN IN THE FORECAST IS WHETHER A THUNDERSTORM
WILL AFFECT THE AIRFIELD THIS AFTERNOON. LATEST HRRR RUN DOES NOT
SHOW MUCH CONVECTIVE DEVELOPMENT IN TEH CLT AREA THIS AFTERNOON.
HENCE...WILL STAY THE COURSE WITH JUST A VCSH 20-23Z WHICH SHOULD BE
THE WINDOW FOR THE BEST COVERAGE AROUND THE AIRPORT. OTHERWISE THE
NIGHT AND EARLY MORNIGN SHOULD BE QUIET AND VFR. THE APPROACH OF A
COLD FRONT ON THU WARRANTS A PROB30 FOR TSRA AT THE END OF THE TAF
PERIOD.
ELSEWHERE...THE ONLY TAF SITE IN WHICH CONFIDENCE IS HIGH ENOUGH
TO CARRY TEMPO TSRA IS AT KAVL THIS AFTERNOON. WILL JUST MENTION A
VCTS AT OTHER AIR FIELDS. OTHERWISE...THE NIGHT SHOULD BE QUIET
AND VFR. THE EXCEPTION IS AT KAVL WHERE LIFR FOG WILL BE IN THE
FORECAST AGAIN FOR EARLY THU. AN APPROACH OF A COLD FRONT ON THU
WARRANTS PROB30 TSRA FOR THE END OF THE TAF PERIOD AT ALL SITES.
OUTLOOK... SHOWERS AND THUNDERSTORMS WILL END THURSDAY EVENING AS A
COLD FRONT MOVES SOUTHEAST OF THE AREA. FRIDAY AND SAT SHOULD BE
QUIET AND VFR...THE EXCEPTION WILL BE THE MOUNTAIN VALLEYS WHERE
EARLY MORNING FOG MAY OCCUR. THUNDERSTORMS WILL RETURN TO THE
FORECAST FOR SUNDAY AFTERNOON THROUGH MONDAY AS ANOTHER COLD FRONT
APPROACHES AND THEN MOVES THROUGH THE AREA ON MONDAY.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-17Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 92% HIGH 100% MED 76% MED 77%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...LG
SHORT TERM...PM
LONG TERM...PM
AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1202 PM EDT WED JUL 23 2014
.SYNOPSIS...
WEAK HIGH PRESSURE ACROSS THE AREA TODAY WILL MOVE AWAY TONIGHT. A
SURFACE FRONT WILL APPROACH FROM THE NORTHWEST TONIGHT AND IS
EXPECTED TO MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THURSDAY
AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT
FOR FRIDAY AND THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON
MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT NOON EDT...RADAR SHOWS NUMEROUS SHOWERS DEVELOPING OVER THE
MOUNTAINS...SO THE IDEA OF HIGHER POPS OVER THE TERRAIN IS WORKING
OUT. THE LATEST HRRR IS SHOWING A BIT MORE CONVECTIVE COVERAGE OVER
THE FOOTHILLS AND PIEDMONT THIS AFTERNOON WHICH ISN`T SURPRISING
SINCE CAPES HAVE INCREASED TO 1500-2000J. HOWEVER...COVERAGE SHOULD
STILL BE SCATTERED IN NATURE. THEREFORE...ADJUSTED POPS PER CURRENT
TRENDS FOR THE AFTERNOON. ALSO MADE SOME MINOR ADJUSTMENTS TO OTHER
GRID FIELDS BASED ON CURRENT OBS AND LATEST CONSHORT RUN.
AS OF 1015 AM...SEE NO REASON BASED ON CURRENT TRENDS AND CAMS TO
DEVIATE MUCH FROM THE OFFICIAL GRIDS. BASED ON OUR CAMPOP AND TCU
DEVLOPING PER SAT PICS...I DID BUMP UP THE POPS IN THE NC CENTRAL
AND SW MOUNTAINS TO SOLID LIKELY THIS AFTERNOON. OTHERWISE...
CONVECTIVE DEVELOPMENT SHOULD BE SCATTERED. TEMPS ARE CURRENTLY
RISING RAPIDLY SO UPPER 80S STILL LOOKS GOOD FOR MAX TEMPS.
AS OF 6 AM...LATEST 11U-3.9U SATELLITE IMAGES INDICATED AN EXPANDING
AREA OF LOW CLOUDS ACROSS THE PIEDMONT AND WEST TO THE SOUTHERN NC
FOOTHILLS. SFC OBSERVATIONS SHOW A WIDE RANGE OF
VISIBILITIES...RANGING FROM M1/4SM AT KMRN TO 10SM ACROSS THE
GREENVILLE/SPARTANBURG/ANDERSON AREAS. THE LOWEST VISIBILITIES ARE
GENERALLY ACROSS THE I-77 CORRIDOR AND WITHIN THE MTN VALLEYS. ALL
PREFERRED GUIDANCE INDICATES THAT THE FOG WILL DISSIPATE DURING THE
TWO HOURS FOLLOWING SUNRISE. I WILL UPDATE THE FORECAST TO ADJUST
FOG AND VISIBILITIES TO THE LATEST OBSERVATIONS AND THINKING. IN
ADDITION...LATEST MOS HAS TRENDED WARMER FOR THIS AFTERNOON...I WILL
WARM FORECAST HIGHS A CLICK. OTHERWISE...THE CURRENT FORECAST IS IN
GOOD SHAPE.
AS OF 320 AM...EARLY MORNING FOG IS EXPECTED TO DEVELOP AND EXPAND
ACROSS THE I-77 CORRDIOR AND WITHIN THE MTN VALLEYS. THE HRRR
CONDENSATION PRESSURE DEFICITS INDICATES THAT THE LOWEST VALUES
WILL EXIST ACROSS THE SOUTHEASTERN HALF OF THE CHARLOTTE METRO AREAS
AND WITHIN THE MTN VALLEYS. FOG SHOULD DISSIPATE DURING THE FIRST
TWO HOURS OF SUNLIGHT. IN ADDITION...EARLY MIXING SHOULD YIELD A
LIGHT SOUTHWEST WIND. GREATER INSOLATION AND SOUTHWEST WINDS SHOULD
RESULT IN STEADILY WARMING TEMPERATURES FROM SUNRISE TO MID
AFTERNOON. I WILL FORECAST HIGHS TO RANGE FROM THE L80S WITHIN THE
MTNS VALLEYS TO U80S TO NEAR 90 EAST OF I-85.
RECENT W/V LOOP INDICATED THAT THE MID LEVEL LOW WAS DRIFTING WEST
ACROSS THE MISSISSIPPI RIVER DELTA...AS ANOTHER TROUGH WILL DIGGING
OVER THE OHIO RIVER VALLEY. AT THE SFC...A WEAK LEE TROUGH MAY
DEVELOP ACROSS THE PIEDMONT DURING THE AFTERNOON. A COLD FRONT WILL
APPROACH FROM THE NW TODAY...REACHING THE SOUTHERN APPALACHIANS LATE
TONIGHT. CAMS INDICATE THAT SHRA AND TSRA WILL FAVOR THE MTNS AND
ADJACENT FOOTHILLS AS EARLY AS MID MORNING TODAY. COVERAGE WILL
INCREASE THROUGH THE HEAT OF THE AFTERNOON...BECOMING SCT ACROSS THE
PIEDMONT. CONVECTION SHOULD GENERALLY DISSIPATE EAST OF THE MTNS ONE
TO TWO HOURS AFTER SUNSET. HOWEVER...I WILL MAINTAIN CHC TO LIKELY
POPS ACROSS THE TN BORDER COUNTIES TO COVER THE ARRIVAL OF PRE
FRONTAL CONVECTION. LOW TEMPERATURES TONIGHT ARE FORECAST TO RANGE
FROM THE MID 60S ACROSS THE MTNS TO LOW 70S EAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM EDT WEDNESDAY...THE MODEL GUIDANCE HAS COME INTO BETTER
AGREEMENT WITH THE PASSAGE OF A SURFACE FRONT MORE OR LESS DURING
PEAK HEATING ON THURSDAY. THE FRONT WILL BE DRIVEN ACROSS THE FCST
AREA BY A FAIRLY STRONG SHORT WAVE IN THE PRESENCE OF SOME UPPER
DIVERGENCE IN THE ENTRANCE REGION OF THE JET OVER THE NORTHEAST.
PLENTY OF LOW LEVEL MOISTURE WILL REMAIN AHEAD OF THE FRONT AS WELL.
THUS...WITH THE TIMING A BIT MORE IN FOCUS...FEEL IT APPROPRIATE TO
BUMP THE PRECIP PROBABILITY UP INTO THE LIKELY RANGE ACROSS THE
ENTIRE FCST AREA IN THE AFTERNOON. MIGHT BE A BIT TOO EARLY TO TALK
TOO MUCH ABOUT SEVERE WEATHER POTENTIAL...BUT THE FRONT SHOULD FOCUS
STORMS IN AN AIR MASS WITH 1500-2500 J/KG OF CAPE...SO THE DAY2
OUTLOOK SEEMS APPROPRIATE. SUSPECT WE WILL HAVE TO CONTEND WITH
SEVERAL SEVERE THUNDERSTORMS. THE FRONT WILL DROP SE DURING THE
EVENING HOURS ENDING THE PRECIP CHANCE BY THE EARLY MORNING HOURS ON
FRIDAY.
BEHIND THE FRONT...THE AIR MASS WILL NOT REALLY BE MUCH COOLER...BUT
IT SHOULD BE A BIT DRIER ON FRIDAY. HIGH PRESSURE SHOULD MOVE IN
DURING THE DAY. NOT REALLY SEEING MUCH TO SUPPORT ANY SHOWERS IN THE
AFTERNOON SO THE PRECIP CHANCES WERE LOWERED. FRIDAY NIGHT SHOULD BE
DRY AS WELL WITH SEASONAL TEMPS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 315 AM WEDNESDAY...STILL EXPECTING THE MEAN UPPER TROF OVER
THE EAST TO FILL OVER THE WEEKEND AS A SHORT WAVE RIDGE MOVES
THROUGH. THIS WILL SUPPORT WEAK HIGH PRESSURE FOR SATURDAY AND INTO
SUNDAY. THINK CONVECTION WILL BE LIMITED TO THE RIDGETOPS SATURDAY
AFTERNOON AND HAVE CUT BACK THE ALREADY MEAGER POP A BIT MORE.
EARLIER RUNS OF THE MODELS SHOWED THE POTENTIAL FOR UPSTREAM MCS
DEVELOPMENT ON SATURDAY NIGHT...AND THAT COULD STILL HAPPEN...BUT
THE MAIN FOCUS LOOKS LIKE IT WILL BE MORE LIKE THE OH VALLEY AND
CENTRAL APPALACHIANS. SO...SATURDAY NIGHT WAS KEPT DRY ACROSS THE
MOUNTAINS AS WELL. EXPECT MORE OF A RETURN TO DIURNAL THUNDERSTORMS
FOR SUNDAY. ANOTHER IN A SERIES OF FAIRLY STRONG SHORT WAVES WILL
ONCE AGAIN CARVE OUT AN UPPER TROF OVER THE EAST EARLY NEXT WEEK. IT
STILL LOOKS LIKE THIS WAVE WILL DRIVE ANOTHER COLD FRONT OVER THE
REGION ON MONDAY. UNLIKE THE EARLIER FRONT...THIS ONE SHOULD USHER
IN A NOTICEABLY DIFFERENT AIR MASS FOR NEXT TUESDAY AS A COOL
CONTINENTAL HIGH MOVES DOWN OVER THE NRN PLAINS...THEN MODIFIES AND
BUILDS IN FROM THE WEST. THAT SHOULD DROP TEMPS A CATEGORY OR MORE
BELOW NORMAL.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...LATEST 11U-3.9U SATELLITE IMAGES INDICATED AN
EXPANDING AREA OF LOW CLOUDS ACROSS THE PIEDMONT AND WEST TO THE
SOUTHERN NC FOOTHILLS. SFC OBSERVATIONS SHOW A WIDE RANGE OF
VISIBILITIES...RANGING FROM M1/4SM AT KAVL/KMRN TO 10SM ACROSS THE
GREENVILLE/SPARTANBURG/ANDERSON AREAS. THE LOWEST VISIBILITIES ARE
GENERALLY ACROSS THE I-77 CORRIDOR AND WITHIN THE MTN VALLEYS. ALL
PREFERRED GUIDANCE INDICATES THAT THE FOG WILL DISSIPATE DURING THE
TWO HOURS FOLLOWING SUNRISE THIS MORNING. BY 14Z...SW WINDS SHOULD
DEVELOP WITH VFR CLOUD COVER. SCT PIEDMONT COVERAGE OF LATE
AFTERNOON TSRA ARE POSSIBLE 18Z TO 24Z. TSRA COVERAGE WILL BE
SIGNIFICANTLY GREATER ACROSS THE MTNS...HIGHLIGHTED WITH A TEMPO
18Z-21Z. ANOTHER ROUND OF LIFR FOG/CIGS ARE POSSIBLE ACROSS THE MTNS
LATE TONIGHT...PATCHY MVFR OVER WET GROUND EAST.
OUTLOOK... SHOWERS AND THUNDERSTORMS THURSDAY WITH THE PASSAGE OF A
COLD FRONT. SCATTERED SHOWERS AND THUNDERSTORMS MAINLY DURING THE
AFTERNOONS AND EVENINGS THROUGH THE END OF THE WEEK.
CONFIDENCE TABLE...
16-22Z 22-04Z 04-10Z 10-16Z
KCLT HIGH 99% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 92% HIGH 97% MED 71% LOW 50%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 89%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...LG
SHORT TERM...PM
LONG TERM...PM
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
624 AM EDT WED JUL 23 2014
.SYNOPSIS...
WEAK HIGH PRESSURE ACROSS THE AREA TODAY WILL MOVE AWAY TONIGHT. A
SURFACE FRONT WILL APPROACH FROM THE NORTHWEST TONIGHT AND IS
EXPECTED TO MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THURSDAY
AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT
FOR FRIDAY AND THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON
MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM...LATEST 11U-3.9U SATELLITE IMAGES INDICATED AN EXPANDING
AREA OF LOW CLOUDS ACROSS THE PIEDMONT AND WEST TO THE SOUTHERN NC
FOOTHILLS. SFC OBSERVATIONS SHOW A WIDE RANGE OF
VISIBILITIES...RANGING FROM M1/4SM AT KMRN TO 10SM ACROSS THE
GREENVILLE/SPARTANBURG/ANDERSON AREAS. THE LOWEST VISIBILITIES ARE
GENERALLY ACROSS THE I-77 CORRIDOR AND WITHIN THE MTN VALLEYS. ALL
PREFERRED GUIDANCE INDICATES THAT THE FOG WILL DISSIPATE DURING THE
TWO HOURS FOLLOWING SUNRISE. I WILL UPDATE THE FORECAST TO ADJUST
FOG AND VISIBILITIES TO THE LATEST OBSERVATIONS AND THINKING. IN
ADDITION...LATEST MOS HAS TRENDED WARMER FOR THIS AFTERNOON...I WILL
WARM FORECAST HIGHS A CLICK. OTHERWISE...THE CURRENT FORECAST IS IN
GOOD SHAPE.
AS OF 320 AM...EARLY MORNING FOG IS EXPECTED TO DEVELOP AND EXPAND
ACROSS THE I-77 CORRDIOR AND WITHIN THE MTN VALLEYS. THE HRRR
CONDENSATION PRESSURE DEFICITS INDICATES THAT THE LOWEST VALUES
WILL EXIST ACROSS THE SOUTHEASTERN HALF OF THE CHARLOTTE METRO AREAS
AND WITHIN THE MTN VALLEYS. FOG SHOULD DISSIPATE DURING THE FIRST
TWO HOURS OF SUNLIGHT. IN ADDITION...EARLY MIXING SHOULD YIELD A
LIGHT SOUTHWEST WIND. GREATER INSOLATION AND SOUTHWEST WINDS SHOULD
RESULT IN STEADILY WARMING TEMPERATURES FROM SUNRISE TO MID
AFTERNOON. I WILL FORECAST HIGHS TO RANGE FROM THE L80S WITHIN THE
MTNS VALLEYS TO U80S TO NEAR 90 EAST OF I-85.
RECENT W/V LOOP INDICATED THAT THE MID LEVEL LOW WAS DRIFTING WEST
ACROSS THE MISSISSIPPI RIVER DELTA...AS ANOTHER TROUGH WILL DIGGING
OVER THE OHIO RIVER VALLEY. AT THE SFC...A WEAK LEE TROUGH MAY
DEVELOP ACROSS THE PIEDMONT DURING THE AFTERNOON. A COLD FRONT WILL
APPROACH FROM THE NW TODAY...REACHING THE SOUTHERN APPALACHIANS LATE
TONIGHT. CAMS INDICATE THAT SHRA AND TSRA WILL FAVOR THE MTNS AND
ADJACENT FOOTHILLS AS EARLY AS MID MORNING TODAY. COVERAGE WILL
INCREASE THROUGH THE HEAT OF THE AFTERNOON...BECOMING SCT ACROSS THE
PIEDMONT. CONVECTION SHOULD GENERALLY DISSIPATE EAST OF THE MTNS ONE
TO TWO HOURS AFTER SUNSET. HOWEVER...I WILL MAINTAIN CHC TO LIKELY
POPS ACROSS THE TN BORDER COUNTIES TO COVER THE ARRIVAL OF PRE
FRONTAL CONVECTION. LOW TEMPERATURES TONIGHT ARE FORECAST TO RANGE
FROM THE MID 60S ACROSS THE MTNS TO LOW 70S EAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM EDT WEDNESDAY...THE MODEL GUIDANCE HAS COME INTO BETTER
AGREEMENT WITH THE PASSAGE OF A SURFACE FRONT MORE OR LESS DURING
PEAK HEATING ON THURSDAY. THE FRONT WILL BE DRIVEN ACROSS THE FCST
AREA BY A FAIRLY STRONG SHORT WAVE IN THE PRESENCE OF SOME UPPER
DIVERGENCE IN THE ENTRANCE REGION OF THE JET OVER THE NORTHEAST.
PLENTY OF LOW LEVEL MOISTURE WILL REMAIN AHEAD OF THE FRONT AS WELL.
THUS...WITH THE TIMING A BIT MORE IN FOCUS...FEEL IT APPROPRIATE TO
BUMP THE PRECIP PROBABILITY UP INTO THE LIKELY RANGE ACROSS THE
ENTIRE FCST AREA IN THE AFTERNOON. MIGHT BE A BIT TOO EARLY TO TALK
TOO MUCH ABOUT SEVERE WEATHER POTENTIAL...BUT THE FRONT SHOULD FOCUS
STORMS IN AN AIR MASS WITH 1500-2500 J/KG OF CAPE...SO THE DAY2
OUTLOOK SEEMS APPROPRIATE. SUSPECT WE WILL HAVE TO CONTEND WITH
SEVERAL SEVERE THUNDERSTORMS. THE FRONT WILL DROP SE DURING THE
EVENING HOURS ENDING THE PRECIP CHANCE BY THE EARLY MORNING HOURS ON
FRIDAY.
BEHIND THE FRONT...THE AIR MASS WILL NOT REALLY BE MUCH COOLER...BUT
IT SHOULD BE A BIT DRIER ON FRIDAY. HIGH PRESSURE SHOULD MOVE IN
DURING THE DAY. NOT REALLY SEEING MUCH TO SUPPORT ANY SHOWERS IN THE
AFTERNOON SO THE PRECIP CHANCES WERE LOWERED. FRIDAY NIGHT SHOULD BE
DRY AS WELL WITH SEASONAL TEMPS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 315 AM WEDNESDAY...STILL EXPECTING THE MEAN UPPER TROF OVER
THE EAST TO FILL OVER THE WEEKEND AS A SHORT WAVE RIDGE MOVES
THROUGH. THIS WILL SUPPORT WEAK HIGH PRESSURE FOR SATURDAY AND INTO
SUNDAY. THINK CONVECTION WILL BE LIMITED TO THE RIDGETOPS SATURDAY
AFTERNOON AND HAVE CUT BACK THE ALREADY MEAGER POP A BIT MORE.
EARLIER RUNS OF THE MODELS SHOWED THE POTENTIAL FOR UPSTREAM MCS
DEVELOPMENT ON SATURDAY NIGHT...AND THAT COULD STILL HAPPEN...BUT
THE MAIN FOCUS LOOKS LIKE IT WILL BE MORE LIKE THE OH VALLEY AND
CENTRAL APPALACHIANS. SO...SATURDAY NIGHT WAS KEPT DRY ACROSS THE
MOUNTAINS AS WELL. EXPECT MORE OF A RETURN TO DIURNAL THUNDERSTORMS
FOR SUNDAY. ANOTHER IN A SERIES OF FAIRLY STRONG SHORT WAVES WILL
ONCE AGAIN CARVE OUT AN UPPER TROF OVER THE EAST EARLY NEXT WEEK. IT
STILL LOOKS LIKE THIS WAVE WILL DRIVE ANOTHER COLD FRONT OVER THE
REGION ON MONDAY. UNLIKE THE EARLIER FRONT...THIS ONE SHOULD USHER
IN A NOTICEABLY DIFFERENT AIR MASS FOR NEXT TUESDAY AS A COOL
CONTINENTAL HIGH MOVES DOWN OVER THE NRN PLAINS...THEN MODIFIES AND
BUILDS IN FROM THE WEST. THAT SHOULD DROP TEMPS A CATEGORY OR MORE
BELOW NORMAL.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...LATEST OBSERVATION INDICATE THAT THE DEWPOINT DEPRESSION
WAS AROUND ONE DEGREE. HRRR AND NAM INDICATE THAT CONDENSATION
PRESSURE DEFICITS WILL FALL ACROSS THE CLT METRO AREA TO LESS THAN 1
MB BETWEEN 9Z TO 12Z. I WILL HIGHLIGHT THE FOG POTENTIAL WITH A
TEMPO GROUP FOR MVFR FOG BETWEEN 9Z TO 12Z. SHORTLY AFTER
SUNRISE...SW WINDS SHOULD DEVELOP WITH VFR CLOUD COVER. SCT COVERAGE
OF LATE AFTERNOON TSRA ARE POSSIBLE 18Z TO 24Z.
ELSEWHERE...THE PRIMARY CONCERN FOR THE REST OF THE NIGHT WILL BE THE
DENSITY AND PLACEMENT OF FOG. KAVL WILL SEE THE GREATEST POTENTIAL
FOR VLIFR FOG AND CEILINGS. ELSEWHERE...I WILL HIGHLIGHT THE FOG
POTENTIAL WITH A TEMPO GROUP FOR MVFR FOG BETWEEN 9Z TO 12Z. SHORTLY
AFTER SUNRISE...SW WINDS SHOULD DEVELOP WITH VFR CLOUD COVER. SCT
COVERAGE OF LATE AFTERNOON TSRA ARE POSSIBLE 18Z TO 24Z
OUTLOOK... SHOWERS AND THUNDERSTORMS THURSDAY WITH THE PASSAGE OF A
COLD FRONT. SCATTERED SHOWERS AND THUNDERSTORMS MAINLY DURING THE
AFTERNOONS AND EVENINGS THROUGH THE END OF THE WEEK.
CONFIDENCE TABLE...
10-16Z 16-22Z 22-04Z 04-10Z
KCLT HIGH 83% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 90% MED 71% HIGH 100% HIGH 100%
KAVL MED 77% HIGH 82% HIGH 100% HIGH 100%
KHKY HIGH 94% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 95% HIGH 94% HIGH 100% HIGH 100%
KAND MED 79% HIGH 99% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...NED
SHORT TERM...PM
LONG TERM...PM
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
323 AM EDT WED JUL 23 2014
.SYNOPSIS...
WEAK HIGH PRESSURE ACROSS THE AREA TODAY WILL MOVE AWAY TONIGHT. A
SURFACE FRONT WILL APPROACH FROM THE NORTHWEST TONIGHT AND IS
EXPECTED TO MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THURSDAY
AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT
FOR FRIDAY AND THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON
MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM...EARLY MORNING FOG IS EXPECTED TO DEVELOP AND EXPAND
ACROSS THE I-77 CORRDIOR AND WITHIN THE MTN VALLEYS. THE HRRR
CONDENSATION PRESSURE DEFICITS INDICATES THAT THE LOWEST VALUES
WILL EXIST ACROSS THE SOUTHEASTERN HALF OF THE CHARLOTTE METRO AREAS
AND WITHIN THE MTN VALLEYS. FOG SHOULD DISSIPATE DURING THE FIRST
TWO HOURS OF SUNLIGHT. IN ADDITION...EARLY MIXING SHOULD YIELD A
LIGHT SOUTHWEST WIND. GREATER INSOLATION AND SOUTHWEST WINDS SHOULD
RESULT IN STEADILY WARMING TEMPERATURES FROM SUNRISE TO MID
AFTERNOON. I WILL FORECAST HIGHS TO RANGE FROM THE L80S WITHIN THE
MTNS VALLEYS TO U80S TO NEAR 90 EAST OF I-85.
RECENT W/V LOOP INDICATED THAT THE MID LEVEL LOW WAS DRIFTING WEST
ACROSS THE MISSISSIPPI RIVER DELTA...AS ANOTHER TROUGH WILL DIGGING
OVER THE OHIO RIVER VALLEY. AT THE SFC...A WEAK LEE TROUGH MAY
DEVELOP ACROSS THE PIEDMONT DURING THE AFTERNOON. A COLD FRONT WILL
APPROACH FROM THE NW TODAY...REACHING THE SOUTHERN APPALACHIANS LATE
TONIGHT. CAMS INDICATE THAT SHRA AND TSRA WILL FAVOR THE MTNS AND
ADJACENT FOOTHILLS AS EARLY AS MID MORNING TODAY. COVERAGE WILL
INCREASE THROUGH THE HEAT OF THE AFTERNOON...BECOMING SCT ACROSS THE
PIEDMONT. CONVECTION SHOULD GENERALLY DISSIPATE EAST OF THE MTNS ONE
TO TWO HOURS AFTER SUNSET. HOWEVER...I WILL MAINTAIN CHC TO LIKELY
POPS ACROSS THE TN BORDER COUNTIES TO COVER THE ARRIVAL OF PRE
FRONTAL CONVECTION. LOW TEMPERATURES TONIGHT ARE FORECAST TO RANGE
FROM THE MID 60S ACROSS THE MTNS TO LOW 70S EAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM EDT WEDNESDAY...THE MODEL GUIDANCE HAS COME INTO BETTER
AGREEMENT WITH THE PASSAGE OF A SURFACE FRONT MORE OR LESS DURING
PEAK HEATING ON THURSDAY. THE FRONT WILL BE DRIVEN ACROSS THE FCST
AREA BY A FAIRLY STRONG SHORT WAVE IN THE PRESENCE OF SOME UPPER
DIVERGENCE IN THE ENTRANCE REGION OF THE JET OVER THE NORTHEAST.
PLENTY OF LOW LEVEL MOISTURE WILL REMAIN AHEAD OF THE FRONT AS WELL.
THUS...WITH THE TIMING A BIT MORE IN FOCUS...FEEL IT APPROPRIATE TO
BUMP THE PRECIP PROBABILITY UP INTO THE LIKELY RANGE ACROSS THE
ENTIRE FCST AREA IN THE AFTERNOON. MIGHT BE A BIT TOO EARLY TO TALK
TOO MUCH ABOUT SEVERE WEATHER POTENTIAL...BUT THE FRONT SHOULD FOCUS
STORMS IN AN AIR MASS WITH 1500-2500 J/KG OF CAPE...SO THE DAY2
OUTLOOK SEEMS APPROPRIATE. SUSPECT WE WILL HAVE TO CONTEND WITH
SEVERAL SEVERE THUNDERSTORMS. THE FRONT WILL DROP SE DURING THE
EVENING HOURS ENDING THE PRECIP CHANCE BY THE EARLY MORNING HOURS ON
FRIDAY.
BEHIND THE FRONT...THE AIR MASS WILL NOT REALLY BE MUCH COOLER...BUT
IT SHOULD BE A BIT DRIER ON FRIDAY. HIGH PRESSURE SHOULD MOVE IN
DURING THE DAY. NOT REALLY SEEING MUCH TO SUPPORT ANY SHOWERS IN THE
AFTERNOON SO THE PRECIP CHANCES WERE LOWERED. FRIDAY NIGHT SHOULD BE
DRY AS WELL WITH SEASONAL TEMPS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 315 AM WEDNESDAY...STILL EXPECTING THE MEAN UPPER TROF OVER
THE EAST TO FILL OVER THE WEEKEND AS A SHORT WAVE RIDGE MOVES
THROUGH. THIS WILL SUPPORT WEAK HIGH PRESSURE FOR SATURDAY AND INTO
SUNDAY. THINK CONVECTION WILL BE LIMITED TO THE RIDGETOPS SATURDAY
AFTERNOON AND HAVE CUT BACK THE ALREADY MEAGER POP A BIT MORE.
EARLIER RUNS OF THE MODELS SHOWED THE POTENTIAL FOR UPSTREAM MCS
DEVELOPMENT ON SATURDAY NIGHT...AND THAT COULD STILL HAPPEN...BUT
THE MAIN FOCUS LOOKS LIKE IT WILL BE MORE LIKE THE OH VALLEY AND
CENTRAL APPALACHIANS. SO...SATURDAY NIGHT WAS KEPT DRY ACROSS THE
MOUNTAINS AS WELL. EXPECT MORE OF A RETURN TO DIURNAL THUNDERSTORMS
FOR SUNDAY. ANOTHER IN A SERIES OF FAIRLY STRONG SHORT WAVES WILL
ONCE AGAIN CARVE OUT AN UPPER TROF OVER THE EAST EARLY NEXT WEEK. IT
STILL LOOKS LIKE THIS WAVE WILL DRIVE ANOTHER COLD FRONT OVER THE
REGION ON MONDAY. UNLIKE THE EARLIER FRONT...THIS ONE SHOULD USHER
IN A NOTICEABLY DIFFERENT AIR MASS FOR NEXT TUESDAY AS A COOL
CONTINENTAL HIGH MOVES DOWN OVER THE NRN PLAINS...THEN MODIFIES AND
BUILDS IN FROM THE WEST. THAT SHOULD DROP TEMPS A CATEGORY OR MORE
BELOW NORMAL.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...LATEST OBSERVATION INDICATE THAT THE DEWPOINT DEPRESSION
WAS AROUND ONE DEGREE. HRRR AND NAM INDICATE THAT CONDENSATION
PRESSURE DEFICITS WILL FALL ACROSS THE CLT METRO AREA TO LESS THAN 1
MB BETWEEN 9Z TO 12Z. I WILL HIGHLIGHT THE FOG POTENTIAL WITH A
TEMPO GROUP FOR MVFR FOG BETWEEN 9Z TO 12Z. SHORTLY AFTER
SUNRISE...SW WINDS SHOULD DEVELOP WITH VFR CLOUD COVER. SCT COVERAGE
OF LATE AFTERNOON TSRA ARE POSSIBLE 18Z TO 24Z.
ELSEWHERE...THE PRIMARY CONCERN FOR THE REST OF THE NIGHT WILL BE THE
DENSITY AND PLACEMENT OF FOG. KAVL WILL SEE THE GREATEST POTENTIAL
FOR VLIFR FOG AND CEILINGS. ELSEWHERE...I WILL HIGHLIGHT THE FOG
POTENTIAL WITH A TEMPO GROUP FOR MVFR FOG BETWEEN 9Z TO 12Z. SHORTLY
AFTER SUNRISE...SW WINDS SHOULD DEVELOP WITH VFR CLOUD COVER. SCT
COVERAGE OF LATE AFTERNOON TSRA ARE POSSIBLE 18Z TO 24Z
OUTLOOK... SHOWERS AND THUNDERSTORMS THURSDAY WITH THE PASSAGE OF A
COLD FRONT. SCATTERED SHOWERS AND THUNDERSTORMS MAINLY DURING THE
AFTERNOONS AND EVENINGS THROUGH THE END OF THE WEEK.
CONFIDENCE TABLE...
07-13Z 13-19Z 19-01Z 01-07Z
KCLT MED 74% HIGH 92% HIGH 100% HIGH 100%
KGSP MED 78% HIGH 89% MED 78% HIGH 100%
KAVL HIGH 86% MED 67% HIGH 100% HIGH 100%
KHKY HIGH 91% HIGH 97% HIGH 100% HIGH 100%
KGMU MED 79% HIGH 91% HIGH 100% HIGH 100%
KAND MED 74% HIGH 91% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...NED
SHORT TERM...PM
LONG TERM...PM
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
258 AM EDT WED JUL 23 2014
.SYNOPSIS...
EXPECT A BRIEF RETURN TO MORE TYPICAL SUMMER WEATHER ON WEDNESDAY
BEFORE A FRONT APPROACHES AND MOVES ACROSS THE REGION ON THURSDAY.
THE PASSAGE OF THE FRONT WILL NOT BRING COOLER AIR...BUT IT SHOULD
BRING DRIER AIR FOR FRIDAY AND INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 250 AM...I WILL UPDATE THE FORECAST TO INCREASE THE FOG
MENTION WITHIN THE MTN VALLEYS AND I-77 CORRDIOR...BASED ON HRRR AND
NAM CONDENSATION PRESSURE DEFICITS.
AS OF 1020 PM...ONLY A FEW SHRA REMAIN ACROSS VARIED PARTS OF THE
CWFA THIS EVENING. ISOLATED SHRA MAY CONTINUE UNTIL SHORTLY AFTER
MIDNIGHT BUT SHUD END SHORTLY THEREAFTER. CURRENTLY MUCH LESS
CLOUDINESS THAN THE MDLS WERE SUGGESTING. HAVE BACKED OFF ON CLOUDS
THIS EVENING...BUT ALLOW SOME CLOUDS TO DEVELOP AFTER MIDNIGHT. LOWS
LOOK ON TRACK.
AS OF 740 PM...CONVECTIVE COVERAGE BEGINNING TO WANE WITH THE LOSS
OF HEATING. COVERAGE WILL CONTINUE TO DIMINISH THRU THE EVENING WITH
MOST CELLS GONE BY MIDNIGHT. HAVE UPDATED POP FOR THESE TRENDS. HAVE
BACKED OFF ON CLOUDS EARLY AS WELL GIVEN SAT PIX...BUT STILL EXPECT
LOW CLOUDS TO RETURN OVERNIGHT. OTHERWISE...GOING FORECAST ON TRACK
WITH UPDATES MAINLY FOR CURRENT CONDITIONS.
AS OF 420 PM...CONVECTION DEVELOPING ALONG AND SOUTH OF THE I-85
CORRIDOR AND SLOWLY MOVING NE. EXPECT THESE TRENDS TO CONTINUE INTO
THE EVENING WITH GREATEST COVERAGE OUTSIDE OF THE MTNS EARLY...THEN
ACROSS THE MTNS NEAR SUNSET. CONVECTION SHUD THEN SLOWLY TAPER OFF
WITH ONLY ISOLATED COVERAGE EXPECTED AFTER MIDNIGHT. HAVE UPDATED
POP...MAINLY EARLY...FOR THESE TRENDS. REST OF THE FCST LOOKS TO BE
IN GOOD SHAPE WITH ONLY UPDATES FOR CURRENT CONDITIONS NEEDED.
AT 230 PM EDT TUESDAY... FOR THE REMAINDER OF THE AFTERNOON AND
EVENING... SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL PERSIST
IN A MOIST BUT ONLY MODESTLY UNSTABLE AIR MASS. NO SIGNIFICANT
SURFACE FEATURES EXIST IN THE CWA TO PROVIDE AN OBVIOUS FOCUS FOR
CONVECTIVE DEVELOPMENT. EXPECT SHOWERS TO DRIFT SLOWLY TO THE
NORTHWEST WITH PERHAPS A SLIGHT PREFERENCE FOR ENHANCEMENT AND BEST
COVERAGE THIS EVENING IN AREAS WITH UPSLOPE FLOW. WINDS ALOFT
THROUGH THE EVENING WILL REMAIN QUITE LIGHT IN THE COL REGION OF THE
MID AND UPPER TROPOSPHERIC HEIGHT FIELD... SO SLOW MOVEMENT OF
CONVECTIVE CELLS IS LIKELY. OVERNIGHT FOG IS POSSIBLE... BUT MODELS
AT THIS TIME ARE NOT DEFINITIVE IN INDICATING WIDESPREAD LOW
VISIBILITY CONDITIONS. NONETHELESS... THE POTENTIAL BEARS WATCHING
OVERNIGHT. THE PRIME AREA FOR SIGNIFICANT FOG WILL BE IN THE
MOUNTAIN VALLEYS AND ACROSS THE NORTHERN FOOTHILLS INTO THE
NORTHWEST PIEDMONT OF NC.
UPPER LEVEL PATTERN ACROSS THE AREA WILL UNDERGO A TRANSITION
TONIGHT AND WEDNESDAY. THE CUTOFF LOW OVER GULF COAST STATES WILL
CONTINUE A SLOW DRIFT TO THE WEST AND HEIGHTS WILL FALL TO OUR NORTH
IN ADVANCE OF SIGNIFICANT TROUGH DIGGING INTO THE EAST. AS TROUGH
HEADS ACROSS THE GREAT LAKES TOWARD THE ATLANTIC COAST... THE
SURFACE RIDGE THAT HAS EXTENDED FROM THE MID-ATLANTIC INTO THE
CAROLINAS FOR A COUPLE OF DAYS WILL DISAPPEAR. IN ITS PLACE WE ARE
LIKELY TO HAVE A LEE TROUGH RETURN TO THE PIEDMONT PORTION OF THE
CWA BY WEDNESDAY AFTERNOON. THE FALLING HEIGHTS AND APPROACHING
DIGGING TROUGH WEDNESDAY AFTERNOON WILL BE ACCOMPANIED BY A WESTERLY
WIND FLOW ALOFT AND SOUTH TO SOUTHWEST WIND IN THE BOUNDARY LAYER.
THE RESULT WILL BE A RETURN TO A MORE DIURNAL PATTERN OF CONVECTION
WITH THE HIGHEST POPS OVER AND NEAR THE HIGHER TERRAIN. WITHOUT A
MAJOR CHANGE IN AIR MASS... SIGNIFICANT TEMPERATURE CHANGES WILL NOT
OCCUR. TUESDAY MORNING LOWS ARE EXPECTED TO BE NEAR 70 WITH 60S IN
THE MOUNTAIN VALLEYS. WEDNESDAY AFTERNOON TEMPERATURES WILL BE
BETWEEN 85 AND 90 EXCEPT IN THE LOWER AND MIDDLE 80S IN THE MOUNTAIN
VALLEYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
AS OF 200 PM EDT TUESDAY...ALL NUMERICAL GUIDANCE IS FORECASTING A
STRONG SHORT WAVE TO MOVE THROUGH THE GREAT LAKES WED NIGHT INTO THU
WHICH WILL DRIVE A SURFACE COLD FRONT SOUTHEASTWARD INTO THE
SOUTHEAST STATES. THE NAM AND GFS HAVE SETTLED ON SIMILAR TIMING
IN REGARD TO THE FRONT WITH BOTH MODELS BRINGING IT TO JUST NW OF
THE NC MOUNTAINS BY 12Z THU...AND THEN BRINGING IT ACROSS THE
MOUNTAINS INTO THE LOWER PIEMDONT BY THURSDAY EVENING. THE FRONT IS
THEN FORECAST TO CLEAR THE AREA BY MIDNIGHT. A DRYER AND MORE STABLE
AIR MASS IS EXPECTED TO OVERSPREAD THE AREA ON FRIDAY AS HIGH
PRESSURE RIDGES SOUTHEASTWARD FROM THE OHIO VALLEY.
IN REGARD TO SENSIBLE WEATHER...SOME LINGERING SHOWERS AND STORMS
MAY BE OVER THE AREA WED EVENING...BUT THEY SHOULD DISSIPATE WITH
LOSS OF HEATING WED NIGHT. HOWEVER...WILL NEED TO RAMP POPS UPWARD
LATE THURSDAY NIGHT AS SOME PREFRONTAL SHOWERS MAY REACH THE
MOUNTAINS BY SUNRISE THURSDAY. WILL CONTINUE TO ADVERTISE LIKELY
POPS IN PORTIONS OF THE MOUNTAINS AND ALSO IN NC PIEDMONT ON THU
AFTERNOON...BUT CONVECTION SHOULD BE SCATTERED ELSEWHERE AS WINDS IN
PROFILES ARE DECIDELY DOWNSLOPE IN NATURE. THERE SHOULD BE PLENTY OF
INSTABILITY THU AFTERNOON WITH CAPES POOLING TO 1500-2000J OVER THE
PIEMDONT. HENCE...A FEW SEVERE STORMS ARE POSSIBLE. WILL FORECAST
DECREASING POPS THU NIGHT AND THEN A DRY DAY ON FRI. MAX TEMPS WILL
BE BELOW CLIMO BOTH THU AND FRI IN THE MOUNTAINS...BUT NEAR CLIMO
OUTSIDE THE MOUNTAINS ON THU AND THEN ABOUT A CATEGORY BELOW CLIMO
ON FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 215 PM TUESDAY...THE MEDIUM RANGE GUIDANCE SUGGESTS THAT THE
EASTERN U.S. TROUGH WILL FLATTEN AS HEIGHTS RISE IN RESPONSE TO
ANOTHER STRONG UPPER WAVE DIGGING INTO THE NORTHERN PLAINS OVER THE
WEEKEND. THIS WAVE IS FORECAST TO SWING ACROSS THE GREAT LAKES AND
RE-ESTABLISH THE EASTERN U.S TROUGH BY MONDAY.
LOOKS LIKE WE SHOULD BE ABLE TO SQUEEZE OUT ONE MORE NICE DAY ON
SATURDAY BEHIND THE THURSDAY FRONTAL PASSAGE AS HIGH PRESSURE
REMAINS WEEKLY RIDGED OVER THE AREA AND MOISTURE LEVELS REMAIN
RELATIVELY LOW. HOWEVER...IT LOOKS LIKE THE FIRST PART OF NEXT
WEEK WILL TURN STORMY. ALL THE MEDIUM RANGE MODELS HINT AT A
POSSIBLE MCS MAKING A RUN AT THE SOUTHERN APPALACHIANS ON SUNDAY. IT
IS DIFFICULT TO SAY WHETHER ANY OF THE PARENT STORMS WILL MAKE IT
ACROSS THE MOUNTAINS...BUT THE OUTFLOW MAY TRIGGER ADDITIONAL STORMS
ACROSS THE PIEDMONT SUNDAY AFTERNOON AND NIGHT. ALSO..AS THE UPPER
TROUGH DIGS OVER THE GREAT LAKES EARLY NEXT WEEK A COLD FRONT IS
FORECAST TO ARRIVE ON MONDAY PROVIDING THE TRIGGER FOR MORE
THUNDERSTORMS. SEVERE STORMS ARE A POSSIBILITY FROM SUNDAY INTO
MONDAY.
THE FRONT IS FORECAST TO CLEAR THE AREA MONDAY NIGHT WHICH SHOULD
ALLOW FOR DRYER AND MORE STABLE AIR TO OVERSPREAD THE AREA FROM THE
NW ON TUESDAY. MAX TEMPS ARE FORECAST TO BE NEAR OR EVEN SLIGHTLY
ABOVE CLIMO SAT THROUGH MONDAY...AND THEN BELOW CLIMO ON TUE BEHIND
THE COLD FRONT
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...LATEST OBSERVATION INDICATE THAT THE DEWPOINT DEPRESSION
WAS AROUND ONE DEGREE. HRRR AND NAM INDICATE THAT CONDENSATION
PRESSURE DEFICITS WILL FALL ACROSS THE CLT METRO AREA TO LESS THAN 1
MB BETWEEN 9Z TO 12Z. I WILL HIGHLIGHT THE FOG POTENTIAL WITH A
TEMPO GROUP FOR MVFR FOG BETWEEN 9Z TO 12Z. SHORTLY AFTER
SUNRISE...SW WINDS SHOULD DEVELOP WITH VFR CLOUD COVER. SCT COVERAGE
OF LATE AFTERNOON TSRA ARE POSSIBLE 18Z TO 24Z.
ELSEWHERE...THE PRIMARY CONCERN FOR THE REST OF THE NIGHT WILL BE THE
DENSITY AND PLACEMENT OF FOG. KAVL WILL SEE THE GREATEST POTENTIAL
FOR VLIFR FOG AND CEILINGS. ELSEWHERE...I WILL HIGHLIGHT THE FOG
POTENTIAL WITH A TEMPO GROUP FOR MVFR FOG BETWEEN 9Z TO 12Z. SHORTLY
AFTER SUNRISE...SW WINDS SHOULD DEVELOP WITH VFR CLOUD COVER. SCT
COVERAGE OF LATE AFTERNOON TSRA ARE POSSIBLE 18Z TO 24Z
OUTLOOK... SHOWERS AND THUNDERSTORMS THURSDAY WITH THE PASSAGE OF A
COLD FRONT. SCATTERED SHOWERS AND THUNDERSTORMS MAINLY DURING THE
AFTERNOONS AND EVENINGS THROUGH THE END OF THE WEEK.
CONFIDENCE TABLE...
07-13Z 13-19Z 19-01Z 01-07Z
KCLT MED 74% HIGH 92% HIGH 100% HIGH 100%
KGSP MED 78% HIGH 89% MED 78% HIGH 100%
KAVL HIGH 86% MED 67% HIGH 100% HIGH 100%
KHKY HIGH 91% HIGH 97% HIGH 100% HIGH 100%
KGMU MED 79% HIGH 91% HIGH 100% HIGH 100%
KAND MED 74% HIGH 91% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...CSH
NEAR TERM...NED
SHORT TERM...LG
LONG TERM...LG
AVIATION...NED
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
242 PM MDT WED JUL 23 2014
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 240 PM MDT WED JUL 23 2014
WATER VAPOR IMAGERY SHOWS STRONG UPPER RIDGING ACROSS MUCH OF THE
WRN TO CNTRL CONUS WITH THE MAIN AXIS FROM CO TO MT. AN UPPER LOW IS
SITTING JUST OFFSHORE THE PACIFIC NORTHWEST WITH SW FLOW OVER THE NW
CONUS...THEN TRANSITIONING TO NW FLOW OVER THE CWA. SURFACE ANALYSIS
SHOWS HIGH PRESSURE ACROSS THE UPPER MIDWEST...AND LOW PRESSURE OVER
MONTANA WITH RETURN FLOW OVER THE HIGH PLAINS. TEMPS HAVE STRUGGLED
TO REACH FORECAST HIGHS WITH TEMPS SO FAR IN THE 80S TO LOWER 90S.
STRONG CAP IN PLACE ACROSS MUCH OF THE CWA WILL KEEP DIURNALLY
TRIGGERED CONVECTION FROM DEVELOPING TODAY. THE CAP WAS EXPECTED TO
BE WEAKEST ACROSS NE WY WHERE TEMPS REACHING MID 90S WOULD BE ENOUGH
TO ERODE IT...BUT TEMPS HAVE BEEN SHORT OF THAT SO FAR. CONVECTION
HAS INITIATED OVER LARAMIE RANGE...AND THE LATEST HRRR RUN SHOWS
THIS CONVECTION MOVING N/NE INTO NE WY AND SW SD THIS EVENING. HAVE
PUT IN ISOLATED POPS THIS EVENING TO ACCOUNT FOR THIS...AND POSSIBLE
OTHER CONVECTION THAT MOVES IN FROM THE WEST. BUT OVERALL MOST AREAS
WILL STAY DRY TONIGHT. ANY STORMS THAT MAKE IT INTO THE AREA MAY BE
SEVERE...BUT OVERALL SEVERE THREAT TONIGHT IS VERY LOW.
UPPER RIDGE AXIS SLIDES EASTWARD THURSDAY...CROSSING THE NRN PLAINS.
UPPER LOW WILL CROSS THE NRN ROCKIES WITH THE SURFACE LOW PUSHING
ACROSS THE CWA. TEMPS ARE EXPECTED TO REACH THE 90S TO 100. A COLD
FRONT WILL SLIDE SE...CROSSING THE CWA THU AFTN/NIGHT. A STRONG CAP
IN PLACE AGAIN WILL HELP KEEP CONVECTION FROM DEVELOPING...BUT COULD
SEE ISOLATED STORMS DEVELOP AS THE FRONT PUSHES THROUGH...PERHAPS
ELEVATED STORMS. CANT RULE OUT A COUPLE STORMS BECOMING SEVERE...BUT
OVERALL THREAT LOOKS MINIMAL AGAIN.
&&
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 240 PM MDT WED JUL 23 2014
UPPER-LEVEL RIDGE OVER THE REGION BREAKS DOWN BY THE END OF THE WEEK
AS AN UPPER LOW SLIDES SOUTHEAST ACROSS SOUTH CENTRAL CANADA. A WEAK
SHORTWAVE IN ZONAL FLOW TO THE SOUTH COULD BRING ANOTHER CHANCE FOR
SHOWERS AND THUNDERSTORMS TO AT LEAST PORTIONS OF THE CWA FRIDAY
AFTERNOON AND NIGHT.
AS THE UPPER LOW SLIDES FURTHER EAST OF THE REGION...THE UPPER RIDGE
WILL REBUILD OVER THE WESTERN CONUS...BRINGING PREDOMINANTLY
NORTHWEST FLOW TO THE NORTHERN PLAINS. THIS WILL RESULT IN COOLER
TEMPERATURES FOR THE REST OF THE EXTENDED PERIOD...ALONG WITH MAINLY
DRY CONDITIONS FROM SATURDAY THROUGH MONDAY. WEAK SHORTWAVE
DISTURBANCES WILL BEGIN TO ROTATE AROUND THE RIDGE AND INTO THE
NORTHERN PLAINS AGAIN BY THE MIDDLE OF NEXT WEEK. WILL KEEP LOW
CHANCE POPS ACROSS PORTIONS OF THE AREA FROM MONDAY NIGHT THROUGH
WEDNESDAY.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 240 PM MDT WED JUL 23 2014
VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH THE FORECAST PERIOD.
ISOLATED THUNDERSTORMS ARE POSSIBLE LATE TODAY ACROSS NORTHEAST WY
AND TONIGHT ACROSS NORTHEAST WY AND MUCH OF WESTERN SD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...13
LONG TERM...26
AVIATION...26
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1142 AM MDT WED JUL 23 2014
.UPDATE...
ISSUED AT 1141 AM MDT WED JUL 23 2014
UPPER RIDGE REMAINS ACROSS THE REGION WITH LOW LEVEL RETURN FLOW
AND THERMAL RIDGE BRINGING WARMER AIR BACK INTO TO THE CWA. 12Z
MODELS ARE TRENDING DRIER FOR THIS AFTN AND EVNG AS MORE
SIGNIFICANT UPPER WAVE ACTIVITY STAYS NORTH OF THE CWA. STRONG CAP
IN PLACE WILL KEEP CONVECTION FROM FORMING ACROSS MOST OF WRN SD.
WILL DROP POPS THIS AFTERNOON NOW...AND THIS EVENING WITH THE
LATER FORECAST ISSUANCE. NAM SHOWS ENOUGH EROSION OF THE CAP
ACROSS THE WARMER NE WY TO WILL LEAVE SL CHC POPS THIS AFTN...AND
OVER THE BLKHLS AREA. HRRR IS SHOWING VERY ISOLATED STORMS
DEVELOPING OVER PORTIONS OF NE WY INTO THE NW SD PLAINS INTO THE
EARLY EVENING.
&&
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 230 AM MDT WED JUL 23 2014
08Z SURFACE ANALYSIS HAD LEE TROUGH FROM CENTRAL MT INTO
SOUTHEAST WY. WEAK OUTFLOW BOUNDARIES NOTED ACROSS SOUTHEAST MT
INTO CENTRAL SD. CLUSTER OF SEVERE CONVECTION HEADING SOUTHEAST
ACROSS SOUTHERN PORTIONS OF THE CWA EARLY THIS MORNING...SPURRED
ON BY WEAK SHORTWAVE OVER NORTHEAST WY PER WATER VAPOUR LOOP AND
30KT LOW LEVEL JET. BEHIND IT...UPPER RIDGE BUILDING OVER MT/WY
WITH UPSTREAM WAVES OVER ID/WESTERN MT. SHORT RANGE GUIDANCE SHOWS
ORGANIZED TSRA EXITING CWA BY 12Z...BUT COULD BE A FEW LINGERING
CELLS EARLY.
TODAY...UPPER RIDGE AMPLIFIES INTO THE NORTHERN PLAINS WITH THERMAL
RIDGE SLOWLY BUILDING. LEE TROUGH SHIFTS EAST A BIT WITH LOW
PRESSURE DEVELOPING OVER CENTRAL WY IN RESPONSE TO SHORTWAVE
ROTATING AROUND RIDGE INTO MT. SURFACE HIGH OVER THE MIDWEST
COMBINED WITH WY LOW RESULTS IN SOMEWHAT TIGHT PRESSURE GRADIENT AND
STRENGTHENING SOUTH/SOUTHEAST FLOW UP TO 25KTS. AHEAD OF LEE
TROUGH...2-4KJ/KG MLCAPE DEVELOPS BY AFTERNOON WITH MLCIN
WEAKENING...ESPECIALLY AFTER 21Z. DIRECT UPSTREAM MID-LEVEL
SHORTWAVES HARD TO DEPICT IN GUIDANCE OR TO SEE UPSTREAM ON WATER
VAPOUR...BUT A COUPLE OF WEAK 700MB SHORTWAVES FORECAST BY MODELS
TO SHIFT INTO EASTERN WY LATE IN THE DAY. THIS SHOULD PROVIDE THE
LAST NUDGE TO ALLOW TSRA TO ERUPT. 0-6KM BULK SHEAR 15-20M/S WITH
RATHER SLOW RIGHT-MOVING SUPERCELL MOVEMENT...IN THE 5-10KT RANGE.
0-6KM MEAN WIND 15-20KTS. WITH SLIGHTLY FASTER MOVEMENT THAN
GUIDANCE SHOWED YESTERDAY...IT APPEARS FLASH FLOOD POTENTIAL NOT
AS CLEARLY DEFINED...ALTHOUGH PRECIPITABLE WATERS DO REACH 150
PERCENT OF NORMAL. LOCAL FLASH FLOOD COMPOSITE PARAMETER HAS
BACKED OFF NOTICEABLY. THUS WILL HOLD OFF ON ANY WATER HEADLINES
AT THIS POINT AND PASS ON CONCERN TO DAY SHIFT. TEMPERATURES WILL
BE NEAR GUIDANCE IN THE WEST AND NEAR BIAS CORRECTED VALUES IN THE
EAST.
TONIGHT...LOW PRESSURE CONSOLIDATES OVER EASTERN MT WITH WARM FRONT
ACROSS NORTHERN SD. ACTIVITY WILL SLOWLY SHIFT EAST AS 30-40KT LOW
LEVEL JET DEVELOPS/INTERSECTS WARM FRONT...TRANSLATING BEST
850-700MB THETA-E ADVECTION EAST OF AREA AFTER MIDNIGHT.
TEMPERATURES WILL STAY UP GIVEN PERSISTENT SOUTHERLY FLOW.
THURSDAY...UPPER RIDGE FLOPS OVER IN RESPONSE TO SHORTWAVE/UPPER LOW
MOVING ACROSS SOUTHERN BC/AB. LOW PRESSURE OVER EASTERN MT WILL MOVE
INTO CENTRAL SD. AHEAD OF IT...STRONG THERMAL RIDGE PEAKS OVER CWA
WITH DRY LINE SURGING INTO SOUTHWEST SD FROM WY. TRAILING COOL FRONT
BEHIND LOW WILL DROP INTO CWA IN THE AFTERNOON. 1-2KJ/KG POST
FRONTAL MLCAPE DEVELOPS OVER THE NORTHERN HALF OF CWA. 2-3KJ/KG
MLCAPE IN WARM SECTOR LIKELY...BUT MLCIN WILL BE MUCH STRONGER
THERE. 0-6KM SHEAR SUFFICIENT FOR SUPERCELLS POST FRONTAL IN THE
NORTH...WITH MARGINAL VALUES IN THE SOUTH...BUT DEEP MIXING MAY
PROMOTE SEVERE WIND GUSTS WITH ANY CONVECTION THAT DEVELOPS OVER
SOUTHWEST SD. EXPECT SEVERE STORMS LATER THURSDAY AFTERNOON IN THE
FAR NORTH. TEMPERATURES WILL BE SLIGHTLY BELOW GUIDANCE POST FRONTAL
AND HAVE ADJUSTED NEAR/ABOVE GUIDANCE SOUTH OF DRY LINE.
THURSDAY NIGHT...COOL FRONT SURGES THROUGH CWA WITH BREEZY SPOTS
BEHIND IT AND CONVECTION MOVING EAST OF THE CWA OVERNIGHT.
TEMPERATURES NEAR GUIDANCE.
&&
.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 230 AM MDT WED JUL 23 2014
UPPER-LEVEL RIDGE BREAKS DOWN BY THE END OF THE WEEK AS A STRONG
SHORTWAVE TROF SLIDES SOUTHEAST ACROSS SOUTH CENTRAL CANADA. THIS
WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS TO THE AREA ON
FRIDAY INTO SATURDAY.
AS THE SHORTWAVE TROF SLIDES EAST...THE UPPER RIDGE WILL RETROGRADE
WEST...BRINGING PREDOMINANTLY NORTHWEST UPPER FLOW TO THE NORTHERN
PLAINS. THIS WILL RESULT IN COOLER TEMPERATURES FOR THE REST OF THE
EXTENDED PERIOD...ALONG WITH MAINLY DRY CONDITIONS.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 1115 AM MDT WED JUL 23 2014
VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH THE FORECAST PERIOD.
ISOLATED THUNDERSTORMS ARE POSSIBLE LATE TODAY ACROSS NORTHEAST WY
AND TONIGHT ACROSS NORTHEAST WY AND MUCH OF WESTERN SD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...13
SHORT TERM...HELGESON
LONG TERM...15
AVIATION...26
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
315 PM CDT WED JUL 23 2014
.DISCUSSION...
CURRENTLY...A COLD FRONT IS PUSHING SOUTH TOWARD THE REGION THIS
AFTERNOON TRIGGERING SHOWERS AND THUNDERSTORMS ACROSS PARTS OF THE
MIDSOUTH. ONE MCS HAS MOVED ACROSS WRN KY/SE MO INTO THE MO
BOOTHEEL AND NE AR THIS AFTERNOON WITH SOME REPORTS OF WIND
DAMAGE. ANOTHER CLUSTER OF STRONG STORMS AND HEAVY RAIN EXTENDS
JUST SOUTH OF I-40 FROM SELMER NORTHEAST TOWARD LEXINGTON
INCLUDING JACKSON.
STORMS ARE FEEDING ON A VERY UNSTABLE AIRMASS WITH DEWPOINTS IN
THE LOWER 70S...CAPES GREATER THAN 3000 J/KG AND LIFTED INDEX
VALUES OF -7C TO -8C. WIND FIELDS ALOFT ARE NOT THAT STRONG WITH
MID LEVEL AT ABOUT 30 KTS...BUT ENOUGH TO SUSTAIN ORGANIZATION.
A SEVERE THUNDERSTORM WATCH CONTINUES UNTIL 7 PM ACROSS MO
BOOTHEEL AND MUCH OF EAST ARKANSAS. THE MCS OVER NE AR WILL
CONTINUE TO PROPAGATE SSW OVER THE NEXT COUPLE OF HOURS WITH
MAINLY A WIND THREAT. ELSEWHERE EXPECT ISOLD-SCT STORMS TO DEVELOP
SOME OF WHICH MAY BE STRONG TO SEVERE WITH MAINLY A WIND THREAT AS
WELL. LOCALIZED FLASH FLOODING IS ALSO POSSIBLE WITH HEAVIER SLOW
MOVING STORMS.
TONIGHT...MCS WILL DEPART INTO CENTRAL ARKANSAS BY EARLY THIS
EVENING AND A COLD FRONT WILL SWEEP SOUTH. MODELS ARE INDICATING
SOME ADDITIONAL DEVELOPMENT ALONG THE FRONT AS IT PASSES THROUGH.
AT THAT POINT INSTABILITY SHOULD BE ON THE WANE WITH A DIMINISHING
SEVERE THREAT. BY MIDNIGHT MOST OF THE ACTIVITY WILL BE SOUTH OF
I-40 WITH A DRIER...COOLER AIRMASS BEGINNING TO MOVE INTO NORTHERN
AREAS.
THURSDAY AND FRIDAY...THE FRONT WILL PUSH SOUTH OF THE AREA
THURSDAY MORNING WITH CLEARING SKIES AND DIMINISHING RAIN CHANCES.
AN UNSEASONABLY COOL AND DRY AIRMASS WILL PUSH IN FOR THURSDAY AND
THURSDAY NIGHT. HIGHS WILL BE IN THE LOWER TO MID 80S WITH LOWS IN
THE UPPER 50S TO MID 60S. FRIDAY WILL BE A LITTLE WARMER...THOUGH
HUMIDITY LEVELS WILL STILL BE LOW...AS UPPER LEVEL HIGH PRESSURE
STARTS TO BUILD BACK IN.
SATURDAY AND SUNDAY...SUMMER HEAT TRIES TO BUILD OVER THE AREA
THANKS TO A STRENGTHENING 594 DM UPPER RIDGE OVER THE SOUTHERN
PLAINS. LOOKS LIKE HIGHS WILL REBOUND INTO THE LOWER AND MID 90S
WITH INCREASING HUMIDITY LEVELS. STILL THINK THE MEX IS TOO HOT
WITH ITS UPPER 90S. HEAT INDEX VALUES MAY CLIMB ABOVE 100 DEGREES
OVER THE WEEKEND. BY SATURDAY NIGHT AN APPROACHING COLD FRONT MAY
LAUNCH AN MCS ACROSS THE NORTHERN TIER OF THE MIDSOUTH SO KEPT
SLIGHT CHANCE POPS ACROSS THE NORTHERN TIER. THUNDERSTORMS CHANCES
WILL INCREASE ACROSS THE AREA SUNDAY INTO SUNDAY NIGHT AS ANOTHER
COLD FRONT IS DRIVEN THROUGH THE AREA BY ANOTHER UNSEASONABLY
STRONG UPPER TROF ACROSS THE GREAT LAKES.
MONDAY INTO WEDNESDAY...DRY AND COOL WEATHER FILTERS IN BEHIND THE
FRONT. WELL BELOW NORMAL TEMPERATURES AND DRY WEATHER EXPECTED.
SJM
&&
.AVIATION...
18Z TAF CYCLE
VFR AND POSSIBLY MVFR CONDITIONS ARE EXPECTED THROUGHOUT
THE FORECAST PERIOD. THUNDERSTORMS HAVE BEGUN TO MOVE INTO THE
AREA AHEAD OF A COLD FRONT EXTENDING FROM QUEBEC INTO THE
SOUTHERN PLAINS. THE HRRR MODEL HAS COVERAGE OF THESE STORMS
DECREASING AS THEY ENTER INTO THE REGION. ADDED VCTS FOR KJBR AND
KMKL THROUGH THIS EVENING. A LOW PRESSURE SYSTEM OVER THE NORTHERN
GULF HAS CAUSED THUNDERSTORM ACTIVITY OVER NORTH MISSISSIPPI SO I
ADDED VCTS AT KTUP. FOG IS POSSIBLE TONIGHT AT KTUP AND KMKL DUE
TO LIGHT WINDS AND LOWER LEVEL MOISTURE. WINDS WILL BE SOUTH AHEAD
OF THE FRONT AND WILL TURN TO THE NORTH AFTER THE FRONT PASSES
EACH TAF SITE BEGINNING WITH KJBR AROUND 00Z.
JPM3
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
305 PM CDT WED JUL 23 2014
.DISCUSSION...A FRONT ALONG THE OHIO RIVER THIS AFTERNOON WILL
PUSH INTO MID TN WITH AT LEAST SCATTERED THUNDERSTORMS CONTINUING
INTO TONIGHT. THE DYNAMICS AND WIND WITH THIS FRONT ARE FAIRLY
WEAK...AND SHORT RANGE MODELS ARE DEPICTING RATHER SPARSE THUNDERSTORM
COVERAGE THIS EVENING. STILL...WE WILL STICK WITH LIKELY POPS FOR
AREAS AROUND BNA AND EASTWARD SINCE THE FRONT WILL BE ENCOUNTERING
A MODERATELY UNSTABLE ATMOSPHERE WITH PW VALUES NEAR 2 INCHES.
THIS WILL NOT BE A WIDESPREAD BIG RAINFALL PRODUCER...BUT A FEW
SPOTS WILL PICK UP SOME HEAVY DOWNPOURS. POPS WILL TREND DOWNWARD
AFTER DARK...SINCE MUCH OF THE CONVECTION WILL BE HEAT DRIVEN.
ON THURSDAY...WE WILL KEEP SMALL POPS IN THE FORECAST DUE TO THE
SLUGGISH FRONT MOVEMENT AND A SECONDARY MID LEVEL TROUGH PASSAGE.
COOLER AND DRIER AIR WILL BE MOVING IN WITH NORTH WINDS AND HIGHS
MAINLY IN THE LOW TO MID 80S.
THURSDAY NIGHT THROUGH SATURDAY...MID TN WILL BE UNDER THE
INFLUENCE OF HIGH PRESSURE. UPPER HEIGHTS WILL BE ELEVATED ...SO
TEMPERATURES WILL REBOUND QUICKLY. HIGHS WILL BE WELL INTO THE 80S
FRIDAY...AND LOWER 90S SATURDAY. HUMIDITY LEVELS WILL BE PLEASANT
ENOUGH THURSDAY NIGHT...BUT BECOMING STICKY BY LATE SATURDAY.
THE NEXT SYSTEM WILL BRING A CHANCE FOR THUNDERSTORMS BY SUNDAY
WITH A FRONTAL PASSAGE EXPECTED SUNDAY NIGHT. INSTABILITY
PARAMETERS ON SUNDAY AFTERNOON ARE RATHER IMPRESSIVE SO STRONG
STORMS WITH SOME HEAVY DOWNPOURS LOOKS POSSIBLE.
A FAIRLY POTENT SURFACE HIGH FOR LATE JULY WILL THEN BUILD IN
FROM THE NORTH. THERMAL TROUGHING LOOKS IMPRESSIVE WITH 850 MB
TEMPS DOWN TO 10 DEG C. HIGHS IN THE LOWER TO MID 80S WITH LOW
RELATIVE HUMIDITY ARE EXPECTED MONDAY THROUGH WEDNESDAY.
13
&&
.PREV DISCUSSION... /ISSUED 1210 PM CDT WED JUL 23 2014/
AVIATION...
RADAR SHOWS SHRA/TSRA NOW SCATTERED AROUND THE ENTIRE MID STATE
AND NEAR ALL 3 TAF SITES. LEANED HEAVILY ON LATEST HRRR MODEL
RUNS...AND WILL MENTION VCTS AT ALL AIRPORTS THROUGH THE AFTERNOON
WITH A BRIEF FEW HOURS BREAK IN ACTIVITY BEFORE MORE CONVECTION IN
THE EVENING. VFR CONDITIONS GENERALLY EXPECTED OVERALL BUT MVFR
CIGS/VIS POSSIBLE IN HEAVIER SHOWERS/STORMS. LIGHT WEST TO
SOUTHWEST WINDS THIS AFTERNOON WILL BECOME NORTHWEST BY EVENING AS
WEAK FRONTAL BOUNDARY SHIFTS SOUTHWARD.
SHAMBURGER
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 70 83 63 89 / 60 20 0 0
CLARKSVILLE 65 81 58 88 / 40 10 0 0
CROSSVILLE 66 79 58 84 / 70 30 10 0
COLUMBIA 68 83 62 90 / 60 20 05 0
LAWRENCEBURG 69 83 63 89 / 50 30 10 0
WAVERLY 65 81 59 89 / 40 10 0 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
110 PM CDT WED JUL 23 2014
.UPDATE...
UPDATED FOR 18Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 1110 AM CDT WED JUL 23 2014/
DISCUSSION...
THE MIDSOUTH IS BETWEEN TWO SYSTEMS TODAY. THERE IS THE WEAK UPPER
LOW SITTING TO THE SOUTH NEAR NEW ORLEANS AND A COLD FRONT
APPROACHING FROM THE NORTH. THE WEAK UPPER LOW IS THROWING SOME
MOISTURE UP OVER NORTH MISSISSIPPI AND THIS SHOULD RESULT IN ISOLD-
SCT SHOWERS AND THUNDERSTORMS THIS AFTERNOON AS THE AIRMASS
CONTINUES TO DESTABILIZE. MEANWHILE TO THE NORTH...A COLD FRONT IS
PRESSING SOUTH. THIS FEATURE HAS KICKED OF AN AREA OF
THUNDERSTORMS NEAR THE CONFLUENCE OF THE OH/MS RIVERS. THESE
STORMS HAVE BEEN PROPAGATING SWWD THANKS TO THE DEEP NORTHEAST FLOW
ALOFT. THIS TREND WILL PROBABLY CONTINUE AND ADDITIONAL ACTIVITY
SHOULD DEVELOP ACROSS NORTHEAST ARKANSAS AND THE MO BOOTHEEL THIS
AFTERNOON...PER 13Z HRRR. UPPED POPS SLIGHTLY...TO 50 PERCENT
ACROSS MUCH OF THE NORTH WHILE DROPPING POPS BACK TO 20 PERCENT IN
THE MEMPHIS METRO AREA. A FEW STRONG TO SEVERE STORMS ARE POSSIBLE
LATER THIS AFTERNOON...ESPECIALLY ACROSS NORTHEAST ARKANSAS AND
THE MO BOOTHEEL. DAMAGING WINDS WILL BE THE MAIN THREAT. UPDATE
ALREADY OUT.
SJM
PREV DISCUSSION... /ISSUED 221 AM CDT WED JUL 23 2014/
AN UPPER LEVEL LOW LOCATED NEAR NEW ORLEANS WILL CONTINUE TO BRING
CHANCES FOR SHOWERS AND THUNDERSTORMS TO NORTHEAST MISSISSIPPI
TODAY. ALTHOUGH...THE SHOWERS AND THUNDERSTORMS HAVE DISSIPATED
OVER THE LAST COUPLE OF HOURS. EXPECT REDEVELOPMENT TO OCCUR BY
MID-MORNING WITH CHANCES INCREASING BY THE AFTERNOON HOURS. THE
SHOWERS AND THUNDERSTORMS MAY ALSO AFFECT PORTIONS OF WEST
TENNESSEE NEAR THE TENNESSEE RIVER.
MEANWHILE...A COLD FRONT WILL APPROACH THE MIDSOUTH TODAY. EXPECT
SOME SHOWERS AND POSSIBLY A FEW THUNDERSTORMS AHEAD OF THE FRONT
TO AFFECT NORTHEAST ARKANSAS AND THE MISSOURI BOOTHEEL THIS
MORNING. CHANCES WILL INCREASE BY THIS AFTERNOON ACROSS THIS AREA
AND INTO NORTHWEST TENNESSEE AS THE FRONT PUSHES INTO THE AREA.
CAN/T RULE OUT A FEW STORMS BECOMING STRONG TO SEVERE THIS
AFTERNOON INTO THIS EVENING. DAMAGING WINDS AND/OR LARGE HAIL
WOULD BE THE MAIN THREATS FROM THESE STORMS. HIGHS WILL BE IN THE
UPPER 80S TO LOWER 90S.
THE COLD FRONT WILL CONTINUE TO PUSH THROUGH THE REST OF THE
MIDSOUTH TONIGHT. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL SHIFT
SOUTH TO SOUTHWEST TENNESSEE AND NORTH MISSISSIPPI BY THE LATE
EVENING AND OVERNIGHT HOURS.
THURSDAY INTO FRIDAY...PLEASANT WEATHER WILL OCCUR BEHIND THE
FRONT AS SFC HIGH PRESSURE BUILDS INTO THE AREA FROM THE OHIO
VALLEY BRINGING COOLER AND DRIER AIR INTO THE MIDSOUTH. HIGHS ON
THURSDAY WILL BE IN THE LOWER TO MID 80S. LOWS THURSDAY NIGHT WILL
BE IN THE UPPER 50S TO MID 60S. THE HIGH WILL QUICKLY SHIFT EAST
BY FRIDAY BUT EVEN THOUGH WARMER TEMPERATURES ARE EXPECTED ON
FRIDAY THE DRY AIR WILL REMAIN IN PLACE THUS NOT FEELING AS WARM.
HOT AND HUMID CONDITIONS WILL RETURN ON SATURDAY AND WILL CONTINUE
UNTIL ANOTHER COLD FRONT PUSHES THROUGH THE AREA SUNDAY INTO
SUNDAY NIGHT. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL OCCUR
AHEAD OF THE FRONT.
BEAUTIFUL WEATHER WILL RETURN FOR THE BEGINNING AND MIDDLE PART OF
NEXT WEEK AS SFC HIGH PRESSURE SETTLES OVER THE REGION BEHIND THE
FRONT. HIGHS WILL BE IN THE LOWER TO MIDDLE 80S WITH LOWS LIKELY
IN THE UPPER 50S TO MID 60S.
&&
.AVIATION...
18Z TAF CYCLE
VFR AND POSSIBLY MVFR CONDITIONS ARE EXPECTED THROUGHOUT
THE FORECAST PERIOD. THUNDERSTORMS HAVE BEGUN TO MOVE INTO THE
AREA AHEAD OF A COLD FRONT EXTENDING FROME QUEBEC INTO THE
SOUTHERN PLAINS. THE HRRR MODEL HAS COVERAGE OF THESE STORMS
DECREASING AS THEY ENTER INTO THE REGION. ADDED VCTS FOR KJBR AND
KMKL THROUGH THIS EVENING. A LOW PRESSURE SYSTEM OVER THE NORTHERN
GULF HAS CAUSED THUNDERSTORM ACTIVITY OVER NORTH MISSISSIPPI SO I
ADDED VCTS AT KTUP. FOG IS POSSIBLE TONIGHT AT KTUP AND KMKL DUE
TO LIGHT WINDS AND LOWER LEVEL MOISTURE. WINDS WILL BE SOUTH AHEAD
OF THE FRONT AND WILL TURN TO THE NORTH AFTER THE FRONT PASSES
EACH TAF SITE BEGINNING WITH KJBR AROUND 00Z.
JPM3
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1210 PM CDT WED JUL 23 2014
.UPDATE...
18Z TAF DISCUSSION.
&&
.AVIATION...
RADAR SHOWS SHRA/TSRA NOW SCATTERED AROUND THE ENTIRE MID STATE
AND NEAR ALL 3 TAF SITES. LEANED HEAVILY ON LATEST HRRR MODEL
RUNS...AND WILL MENTION VCTS AT ALL AIRPORTS THROUGH THE
AFTERNOON WITH A BRIEF FEW HOURS BREAK IN ACTIVITY BEFORE MORE
CONVECTION IN THE EVENING. VFR CONDITIONS GENERALLY EXPECTED
OVERALL BUT MVFR CIGS/VIS POSSIBLE IN HEAVIER SHOWERS/STORMS.
LIGHT WEST TO SOUTHWEST WINDS THIS AFTERNOON WILL BECOME NORTHWEST
BY EVENING AS WEAK FRONTAL BOUNDARY SHIFTS SOUTHWARD.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 1036 AM CDT WED JUL 23 2014/
UPDATE...
RADAR IMAGERY THIS MORNING SHOWS MCS MOVING SOUTHWARD ACROSS
WESTERN KY CONTINUES TO WEAKEN...BUT ADDITIONAL CONVECTION IS
FORMING ON OUTFLOW AHEAD OF THE COMPLEX. OTHER SHOWERS AND STORMS
ARE NOW DEVELOPING ACROSS THE MID STATE. LATEST HRRR RUNS SUGGEST
SCATTERED SHOWERS AND STORMS WILL BLOSSOM THROUGH NOON THEN
CONTINUE INTO THE AFTERNOON BEFORE DIMINISHING...WITH ADDITIONAL
ACTIVITY DEVELOPING THIS EVENING. HOWEVER...EARLIER RUNS HAD
DIFFERENT SOLUTIONS...LEADING TO LOW CONFIDENCE IN EVENTUAL
COVERAGE AND PLACEMENT OF STORMS. NEVERTHELESS...WILL BEGIN HIGH
CHANCE POPS NOW AND CONTINUE THROUGH THE AFTERNOON. CANNOT RULE
OUT SOME STRONGER STORMS MAINLY THIS AFTERNOON WITH LI VALUES NEAR
-6 AND CONSIDERABLE DRY AIR NOTED ALOFT ON 12Z OHX SOUNDING...BUT
NOT ANTICIPATING ANY WIDESPREAD STRONG OR SEVERE ACTIVITY. OTHER
ADJUSTMENTS WERE MADE TO GRIDS BASED ON LATEST OBS...BUT REST OF
FORECAST IS ESSENTIALLY UNCHANGED.
SHAMBURGER
PREV DISCUSSION... /ISSUED 738 AM CDT WED JUL 23 2014/
UPDATE...FOR 12Z TAFS
AVIATION...
A FRONTAL BOUNDARY WILL MOVE INTO MIDDLE TN FROM THE NW LATER TODAY
BRINGING THUNDERSTORMS AND SHOWERS. SOME STRONG STORMS WILL BE
POSSIBLE. INTRODUCED VICINITY STORMS AT CKV AROUND 18Z. WILL HAVE
TO SEE HOW CONVECTION MOVING INTO WESTERN KENTUCKY TRACKS THIS
MORNING TO INCLUDE SOMETHING MORE THAN VICINITY. LATEST HRRR IS
FORECASTING REDEVELOPMENT OF A LINE OF STORMS LATER THIS MORNING
THAT FALLS APART BEFORE IMPACTING NW MIDDLE TN. REGARDLESS IF THAT
LINE DOES FALL APART CONDITIONS WILL BE FAVORABLE FOR SCATTERED
THUNDERSTORMS BY 22Z FOR BNA AND CSV. WINDS WILL SHIFT TO BE OUT
OF THE NW AROUND 00Z TODAY FOR CKV AND BNA...AROUND 02Z FOR CSV.
SOME LIGHT SHOWERS MAY LINGER OVERNIGHT TONIGHT WITH CIGS FALLING
TO 3KFT OR LESS BY MIDNIGHT AND DECREASING VIS FOR CKV AND BNA.
PREV DISCUSSION... /ISSUED 344 AM CDT WED JUL 23 2014/
DISCUSSION...
UPPER LOW IS LOCATED NEAR NEW ORLEANS THIS MORNING WITH AN
INVERTED TROUGH AXIS EXTENDING NORTHEASTWARD ACROSS EASTERN TN.
MEANWHILE...SFC BOUNDARY EXTENDS FROM LAKE ERIE SW THROUGH MO.
NORTHWESTERLY FLOW ALOFT TO BECOME MORE ENHANCED AS WE MOVE
THROUGH TODAY. THIS WILL ALLOW THIS FRONTAL BOUNDARY TO MOVE OUR
WAY AND MOVE ACROSS THE AREA TONIGHT. 18Z AND 00Z DEPICTIONS OF
THE UPPER LEVEL FLOW REVEAL A DIVERGING FLOW ALOFT AND THIS WILL
COUPLE WITH ELEVATED LEVELS OF CURVATURE AND SHEAR JUST TO THE
NORTHWEST OF THE DIVERGING FLOW. LATEST HRRR IN SUPPORT OF LATE
MORNING TO EARLY AFTERNOON CONVECTIVE DEVELOPMENT ACROSS OUR
SOUTHEAST WHICH IS IN CLOSER PROXIMITY TO THE INVERTED TROUGH.
THEN...BY MID AND LATE AFTERNOON...THE APPROACHING FRONTAL
BOUNDARY WILL KICK OFF SOME CONVECTION ACROSS THE NORTHWEST HALF
OF MIDDLE TN. ALL IN ALL...POPS OF 30-50 PERCENT LOOKS REASONABLE
FOR TODAY. CAPES WILL REACH 2000 J/KG BY LATE AFTERNOON SO CANNOT
RULE OUT SOME STRONG STORMS THIS AFTERNOON AND EVENING AS WELL.
SO...AGAIN TONIGHT...A GOOD CHANCE OF SHOWERS AND TSTMS WILL BE IN
THE FORECAST AS THE FROPA OCCURS AND PVA WORKS ACROSS OUR AREA.
THE FRONTAL BOUNDARY WILL BE A SLOW MOVER. THUS...LOW POPS WILL BE
INCLUDED FOR THURSDAY AS WELL.
FOR THE NEAR TERM TEMPS...ANOTHER WARM TO HOT DAY TODAY AS THE FRONT
PRESSES DOWN SLOWLY FROM THE NORTH. NOT NEARLY AS HOT ON THURSDAY AS
THE REPLACING AIRMASS FEATURES A REASONABLY IMPRESSIVE THERMAL
TROUGH FOR THIS TIME OF YEAR. THURSDAY LOOKS LIKE HIGHS IN THE
LOWER TO MID 80S WITH DEWPOINTS IN THE LOWER 60S. LOWER 60S FOR
LOWS ARE EXPECTED THU NT.
IN THE EXT FCST...UPPER TROUGHING WILL PULL EAST AS RIDGING ATTEMPTS
TO EXPAND EASTWARD FROM THE SOUTHWESTERN U.S.. NORTHWEST FLOW WILL
BE WEAKER BUT JUST STRONG ENOUGH TO ALLOW ANOTHER COLD FRONT TO MOVE
OUR WAY THIS WEEKEND. AS THE FRONT REACHES THE MID STATE ON SUNDAY
NIGHT...UPPER TROUGHING OVER THE EASTERN U.S. IS EXPECTED TO
AMPLIFY. LOOKS LIKE WE COULD SEE SOME APPRECIABLE RAINFALL FOR
SUNDAY AND SUNDAY NIGHT. INSTABILITY PARAMETERS ON SUNDAY AFTERNOON
ARE RATHER IMPRESSIVE SO ANOTHER ROUND OF STRONG STORMS LOOKS
POSSIBLE.
A FAIRLY POTENT SFC HIGH FOR LATE JULY WILL THEN BUILD IN FROM THE
NORTH. THERMAL TROUGHING LOOKS IMPRESSIVE WITH 850 MB TEMPS OF
AROUND 12C. HIGH TEMPS IN THE LOWER TO MID 80S WITH LOW RELATIVE
HUMIDITY IS EXPECTED MON THROUGH WED OF NEXT WEEK. WILL BE
UNDERCUTTING THE MEX NUMBERS AS THE EURO SOLUTION IS EVEN STRONGER
WITH THE THERMAL TROUGHING.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1036 AM CDT WED JUL 23 2014
.UPDATE...
RADAR IMAGERY THIS MORNING SHOWS MCS MOVING SOUTHWARD ACROSS
WESTERN KY CONTINUES TO WEAKEN...BUT ADDITIONAL CONVECTION IS
FORMING ON OUTFLOW AHEAD OF THE COMPLEX. OTHER SHOWERS AND STORMS
ARE NOW DEVELOPING ACROSS THE MID STATE. LATEST HRRR RUNS SUGGEST
SCATTERED SHOWERS AND STORMS WILL BLOSSOM THROUGH NOON THEN
CONTINUE INTO THE AFTERNOON BEFORE DIMINISHING...WITH ADDITIONAL
ACTIVITY DEVELOPING THIS EVENING. HOWEVER...EARLIER RUNS HAD
DIFFERENT SOLUTIONS...LEADING TO LOW CONFIDENCE IN EVENTUAL
COVERAGE AND PLACEMENT OF STORMS. NEVERTHELESS...WILL BEGIN HIGH
CHANCE POPS NOW AND CONTINUE THROUGH THE AFTERNOON. CANNOT RULE
OUT SOME STRONGER STORMS MAINLY THIS AFTERNOON WITH LI VALUES NEAR
-6 AND CONSIDERABLE DRY AIR NOTED ALOFT ON 12Z OHX SOUNDING...BUT
NOT ANTICIPATING ANY WIDESPREAD STRONG OR SEVERE ACTIVITY. OTHER
ADJUSTMENTS WERE MADE TO GRIDS BASED ON LATEST OBS...BUT REST OF
FORECAST IS ESSENTIALLY UNCHANGED.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 738 AM CDT WED JUL 23 2014/
UPDATE...FOR 12Z TAFS
AVIATION...
A FRONTAL BOUNDARY WILL MOVE INTO MIDDLE TN FROM THE NW LATER TODAY
BRINGING THUNDERSTORMS AND SHOWERS. SOME STRONG STORMS WILL BE
POSSIBLE. INTRODUCED VICINITY STORMS AT CKV AROUND 18Z. WILL HAVE
TO SEE HOW CONVECTION MOVING INTO WESTERN KENTUCKY TRACKS THIS
MORNING TO INCLUDE SOMETHING MORE THAN VICINITY. LATEST HRRR IS
FORECASTING REDEVELOPMENT OF A LINE OF STORMS LATER THIS MORNING
THAT FALLS APART BEFORE IMPACTING NW MIDDLE TN. REGARDLESS IF THAT
LINE DOES FALL APART CONDITIONS WILL BE FAVORABLE FOR SCATTERED
THUNDERSTORMS BY 22Z FOR BNA AND CSV. WINDS WILL SHIFT TO BE OUT
OF THE NW AROUND 00Z TODAY FOR CKV AND BNA...AROUND 02Z FOR CSV.
SOME LIGHT SHOWERS MAY LINGER OVERNIGHT TONIGHT WITH CIGS FALLING
TO 3KFT OR LESS BY MIDNIGHT AND DECREASING VIS FOR CKV AND BNA.
PREV DISCUSSION... /ISSUED 344 AM CDT WED JUL 23 2014/
DISCUSSION...
UPPER LOW IS LOCATED NEAR NEW ORLEANS THIS MORNING WITH AN
INVERTED TROUGH AXIS EXTENDING NORTHEASTWARD ACROSS EASTERN TN.
MEANWHILE...SFC BOUNDARY EXTENDS FROM LAKE ERIE SW THROUGH MO.
NORTHWESTERLY FLOW ALOFT TO BECOME MORE ENHANCED AS WE MOVE
THROUGH TODAY. THIS WILL ALLOW THIS FRONTAL BOUNDARY TO MOVE OUR
WAY AND MOVE ACROSS THE AREA TONIGHT. 18Z AND 00Z DEPICTIONS OF
THE UPPER LEVEL FLOW REVEAL A DIVERGING FLOW ALOFT AND THIS WILL
COUPLE WITH ELEVATED LEVELS OF CURVATURE AND SHEAR JUST TO THE
NORTHWEST OF THE DIVERGING FLOW. LATEST HRRR IN SUPPORT OF LATE
MORNING TO EARLY AFTERNOON CONVECTIVE DEVELOPMENT ACROSS OUR
SOUTHEAST WHICH IS IN CLOSER PROXIMITY TO THE INVERTED TROUGH.
THEN...BY MID AND LATE AFTERNOON...THE APPROACHING FRONTAL
BOUNDARY WILL KICK OFF SOME CONVECTION ACROSS THE NORTHWEST HALF
OF MIDDLE TN. ALL IN ALL...POPS OF 30-50 PERCENT LOOKS REASONABLE
FOR TODAY. CAPES WILL REACH 2000 J/KG BY LATE AFTERNOON SO CANNOT
RULE OUT SOME STRONG STORMS THIS AFTERNOON AND EVENING AS WELL.
SO...AGAIN TONIGHT...A GOOD CHANCE OF SHOWERS AND TSTMS WILL BE IN
THE FORECAST AS THE FROPA OCCURS AND PVA WORKS ACROSS OUR AREA.
THE FRONTAL BOUNDARY WILL BE A SLOW MOVER. THUS...LOW POPS WILL BE
INCLUDED FOR THURSDAY AS WELL.
FOR THE NEAR TERM TEMPS...ANOTHER WARM TO HOT DAY TODAY AS THE FRONT
PRESSES DOWN SLOWLY FROM THE NORTH. NOT NEARLY AS HOT ON THURSDAY AS
THE REPLACING AIRMASS FEATURES A REASONABLY IMPRESSIVE THERMAL
TROUGH FOR THIS TIME OF YEAR. THURSDAY LOOKS LIKE HIGHS IN THE
LOWER TO MID 80S WITH DEWPOINTS IN THE LOWER 60S. LOWER 60S FOR
LOWS ARE EXPECTED THU NT.
IN THE EXT FCST...UPPER TROUGHING WILL PULL EAST AS RIDGING ATTEMPTS
TO EXPAND EASTWARD FROM THE SOUTHWESTERN U.S.. NORTHWEST FLOW WILL
BE WEAKER BUT JUST STRONG ENOUGH TO ALLOW ANOTHER COLD FRONT TO MOVE
OUR WAY THIS WEEKEND. AS THE FRONT REACHES THE MID STATE ON SUNDAY
NIGHT...UPPER TROUGHING OVER THE EASTERN U.S. IS EXPECTED TO
AMPLIFY. LOOKS LIKE WE COULD SEE SOME APPRECIABLE RAINFALL FOR
SUNDAY AND SUNDAY NIGHT. INSTABILITY PARAMETERS ON SUNDAY AFTERNOON
ARE RATHER IMPRESSIVE SO ANOTHER ROUND OF STRONG STORMS LOOKS
POSSIBLE.
A FAIRLY POTENT SFC HIGH FOR LATE JULY WILL THEN BUILD IN FROM THE
NORTH. THERMAL TROUGHING LOOKS IMPRESSIVE WITH 850 MB TEMPS OF
AROUND 12C. HIGH TEMPS IN THE LOWER TO MID 80S WITH LOW RELATIVE
HUMIDITY IS EXPECTED MON THROUGH WED OF NEXT WEEK. WILL BE
UNDERCUTTING THE MEX NUMBERS AS THE EURO SOLUTION IS EVEN STRONGER
WITH THE THERMAL TROUGHING.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
738 AM CDT WED JUL 23 2014
.UPDATE...FOR 12Z TAFS
&&
.AVIATION...
A FRONTAL BOUNDARY WILL MOVE INTO MIDDLE TN FROM THE NW LATER TODAY
BRINGING THUNDERSTORMS AND SHOWERS. SOME STRONG STORMS WILL BE
POSSIBLE. INTRODUCED VICINITY STORMS AT CKV AROUND 18Z. WILL HAVE
TO SEE HOW CONVECTION MOVING INTO WESTERN KENTUCKY TRACKS THIS
MORNING TO INCLUDE SOMETHING MORE THAN VICINITY. LATEST HRRR IS
FORECASTING REDEVELOPMENT OF A LINE OF STORMS LATER THIS MORNING
THAT FALLS APART BEFORE IMPACTING NW MIDDLE TN. REGARDLESS IF THAT
LINE DOES FALL APART CONDITIONS WILL BE FAVORABLE FOR SCATTERED
THUNDERSTORMS BY 22Z FOR BNA AND CSV. WINDS WILL SHIFT TO BE OUT
OF THE NW AROUND 00Z TODAY FOR CKV AND BNA...AROUND 02Z FOR CSV.
SOME LIGHT SHOWERS MAY LINGER OVERNIGHT TONIGHT WITH CIGS FALLING
TO 3KFT OR LESS BY MIDNIGHT AND DECREASING VIS FOR CKV AND BNA.
&&
.PREV DISCUSSION... /ISSUED 344 AM CDT WED JUL 23 2014/
DISCUSSION...
UPPER LOW IS LOCATED NEAR NEW ORLEANS THIS MORNING WITH AN
INVERTED TROUGH AXIS EXTENDING NORTHEASTWARD ACROSS EASTERN TN.
MEANWHILE...SFC BOUNDARY EXTENDS FROM LAKE ERIE SW THROUGH MO.
NORTHWESTERLY FLOW ALOFT TO BECOME MORE ENHANCED AS WE MOVE
THROUGH TODAY. THIS WILL ALLOW THIS FRONTAL BOUNDARY TO MOVE OUR
WAY AND MOVE ACROSS THE AREA TONIGHT. 18Z AND 00Z DEPICTIONS OF
THE UPPER LEVEL FLOW REVEAL A DIVERGING FLOW ALOFT AND THIS WILL
COUPLE WITH ELEVATED LEVELS OF CURVATURE AND SHEAR JUST TO THE
NORTHWEST OF THE DIVERGING FLOW. LATEST HRRR IN SUPPORT OF LATE
MORNING TO EARLY AFTERNOON CONVECTIVE DEVELOPMENT ACROSS OUR
SOUTHEAST WHICH IS IN CLOSER PROXIMITY TO THE INVERTED TROUGH.
THEN...BY MID AND LATE AFTERNOON...THE APPROACHING FRONTAL
BOUNDARY WILL KICK OFF SOME CONVECTION ACROSS THE NORTHWEST HALF
OF MIDDLE TN. ALL IN ALL...POPS OF 30-50 PERCENT LOOKS REASONABLE
FOR TODAY. CAPES WILL REACH 2000 J/KG BY LATE AFTERNOON SO CANNOT
RULE OUT SOME STRONG STORMS THIS AFTERNOON AND EVENING AS WELL.
SO...AGAIN TONIGHT...A GOOD CHANCE OF SHOWERS AND TSTMS WILL BE IN
THE FORECAST AS THE FROPA OCCURS AND PVA WORKS ACROSS OUR AREA.
THE FRONTAL BOUNDARY WILL BE A SLOW MOVER. THUS...LOW POPS WILL BE
INCLUDED FOR THURSDAY AS WELL.
FOR THE NEAR TERM TEMPS...ANOTHER WARM TO HOT DAY TODAY AS THE FRONT
PRESSES DOWN SLOWLY FROM THE NORTH. NOT NEARLY AS HOT ON THURSDAY AS
THE REPLACING AIRMASS FEATURES A REASONABLY IMPRESSIVE THERMAL
TROUGH FOR THIS TIME OF YEAR. THURSDAY LOOKS LIKE HIGHS IN THE
LOWER TO MID 80S WITH DEWPOINTS IN THE LOWER 60S. LOWER 60S FOR
LOWS ARE EXPECTED THU NT.
IN THE EXT FCST...UPPER TROUGHING WILL PULL EAST AS RIDGING ATTEMPTS
TO EXPAND EASTWARD FROM THE SOUTHWESTERN U.S.. NORTHWEST FLOW WILL
BE WEAKER BUT JUST STRONG ENOUGH TO ALLOW ANOTHER COLD FRONT TO MOVE
OUR WAY THIS WEEKEND. AS THE FRONT REACHES THE MID STATE ON SUNDAY
NIGHT...UPPER TROUGHING OVER THE EASTERN U.S. IS EXPECTED TO
AMPLIFY. LOOKS LIKE WE COULD SEE SOME APPRECIABLE RAINFALL FOR
SUNDAY AND SUNDAY NIGHT. INSTABILITY PARAMETERS ON SUNDAY AFTERNOON
ARE RATHER IMPRESSIVE SO ANOTHER ROUND OF STRONG STORMS LOOKS
POSSIBLE.
A FAIRLY POTENT SFC HIGH FOR LATE JULY WILL THEN BUILD IN FROM THE
NORTH. THERMAL TROUGHING LOOKS IMPRESSIVE WITH 850 MB TEMPS OF
AROUND 12C. HIGH TEMPS IN THE LOWER TO MID 80S WITH LOW RELATIVE
HUMIDITY IS EXPECTED MON THROUGH WED OF NEXT WEEK. WILL BE
UNDERCUTTING THE MEX NUMBERS AS THE EURO SOLUTION IS EVEN STRONGER
WITH THE THERMAL TROUGHING.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
11
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
344 AM CDT WED JUL 23 2014
.DISCUSSION...
UPPER LOW IS LOCATED NEAR NEW ORLEANS THIS MORNING WITH AN
INVERTED TROUGH AXIS EXTENDING NORTHEASTWARD ACROSS EASTERN TN.
MEANWHILE...SFC BOUNDARY EXTENDS FROM LAKE ERIE SW THROUGH MO.
NORTHWESTERLY FLOW ALOFT TO BECOME MORE ENHANCED AS WE MOVE
THROUGH TODAY. THIS WILL ALLOW THIS FRONTAL BOUNDARY TO MOVE OUR
WAY AND MOVE ACROSS THE AREA TONIGHT. 18Z AND 00Z DEPICTIONS OF
THE UPPER LEVEL FLOW REVEAL A DIVERGING FLOW ALOFT AND THIS WILL
COUPLE WITH ELEVATED LEVELS OF CURVATURE AND SHEAR JUST TO THE
NORTHWEST OF THE DIVERGING FLOW. LATEST HRRR IN SUPPORT OF LATE
MORNING TO EARLY AFTERNOON CONVECTIVE DEVELOPMENT ACROSS OUR
SOUTHEAST WHICH IS IN CLOSER PROXIMITY TO THE INVERTED TROUGH.
THEN...BY MID AND LATE AFTERNOON...THE APPROACHING FRONTAL
BOUNDARY WILL KICK OFF SOME CONVECTION ACROSS THE NORTHWEST HALF
OF MIDDLE TN. ALL IN ALL...POPS OF 30-50 PERCENT LOOKS REASONABLE
FOR TODAY. CAPES WILL REACH 2000 J/KG BY LATE AFTERNOON SO CANNOT
RULE OUT SOME STRONG STORMS THIS AFTERNOON AND EVENING AS WELL.
SO...AGAIN TONIGHT...A GOOD CHANCE OF SHOWERS AND TSTMS WILL BE IN
THE FORECAST AS THE FROPA OCCURS AND PVA WORKS ACROSS OUR AREA.
THE FRONTAL BOUNDARY WILL BE A SLOW MOVER. THUS...LOW POPS WILL BE
INCLUDED FOR THURSDAY AS WELL.
FOR THE NEAR TERM TEMPS...ANOTHER WARM TO HOT DAY TODAY AS THE FRONT
PRESSES DOWN SLOWLY FROM THE NORTH. NOT NEARLY AS HOT ON THURSDAY AS
THE REPLACING AIRMASS FEATURES A REASONABLY IMPRESSIVE THERMAL
TROUGH FOR THIS TIME OF YEAR. THURSDAY LOOKS LIKE HIGHS IN THE
LOWER TO MID 80S WITH DEWPOINTS IN THE LOWER 60S. LOWER 60S FOR
LOWS ARE EXPECTED THU NT.
IN THE EXT FCST...UPPER TROUGHING WILL PULL EAST AS RIDGING ATTEMPTS
TO EXPAND EASTWARD FROM THE SOUTHWESTERN U.S.. NORTHWEST FLOW WILL
BE WEAKER BUT JUST STRONG ENOUGH TO ALLOW ANOTHER COLD FRONT TO MOVE
OUR WAY THIS WEEKEND. AS THE FRONT REACHES THE MID STATE ON SUNDAY
NIGHT...UPPER TROUGHING OVER THE EASTERN U.S. IS EXPECTED TO
AMPLIFY. LOOKS LIKE WE COULD SEE SOME APPRECIABLE RAINFALL FOR
SUNDAY AND SUNDAY NIGHT. INSTABILITY PARAMETERS ON SUNDAY AFTERNOON
ARE RATHER IMPRESSIVE SO ANOTHER ROUND OF STRONG STORMS LOOKS
POSSIBLE.
A FAIRLY POTENT SFC HIGH FOR LATE JULY WILL THEN BUILD IN FROM THE
NORTH. THERMAL TROUGHING LOOKS IMPRESSIVE WITH 850 MB TEMPS OF
AROUND 12C. HIGH TEMPS IN THE LOWER TO MID 80S WITH LOW RELATIVE
HUMIDITY IS EXPECTED MON THROUGH WED OF NEXT WEEK. WILL BE
UNDERCUTTING THE MEX NUMBERS AS THE EURO SOLUTION IS EVEN STRONGER
WITH THE THERMAL TROUGHING.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 92 70 83 62 / 50 60 30 0
CLARKSVILLE 92 66 82 58 / 50 50 20 0
CROSSVILLE 85 67 81 58 / 50 60 50 10
COLUMBIA 92 70 84 63 / 40 60 30 05
LAWRENCEBURG 91 69 84 63 / 40 60 30 10
WAVERLY 92 67 82 59 / 50 50 20 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1235 AM CDT WED JUL 23 2014
.UPDATE...AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 1059 PM CDT TUE JUL 22 2014/
UPDATE...
SATELLITE AND RADAR HAVE SHOWN SOME REDEVELOPMENT OF SHOWERS AND
THUNDERSTORMS OVER NORTHWEST AL THAT ARE MOVING GENERALLY
WESTWARD. OTHER SHOWERS AND THUNDERSTORMS CONTINUE TO CLIP
TALLAHATCHIE AND YALOBUSHA COUNTIES IN NORTH MS. BASED ON THE 00Z
NAM AND LATEST HRRR...UPDATED TO INCLUDE AT LEAST A 20 PERCENT
CHANCE OF SHOWERS AND THUNDERSTORMS THE REMAINDER OF THE NIGHT
ACROSS MOST OF NORTH MS.
JCL
UPDATE... /ISSUED 948 PM CDT TUE JUL 22 2014/
AN UPPER LEVEL LOW PRESSURE SYSTEM WAS LOCATED ALONG THE SOUTH AL
AND SOUTH MS BORDER THIS EVENING MOVING SLOWLY WESTWARD. SCATTERED
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THIS SYSTEM THAT SPREAD
INTO PORTIONS OF NORTH MS AND WEST TN EARLIER TODAY HAVE JUST
ABOUT DISSIPATED OR MOVED OUT OF THE REGION FOR THE NIGHT. LINGERING
SHOWERS AND THUNDERSTORMS ROTATING AROUND THIS LOW PRESSURE SYSTEM
WERE MOVING SOUTHWESTWARD OUT OF YALOBUSHA COUNTY IN NORTH MS AND
MAY CLIP THE SOUTHERN PORTIONS OF TALLAHATCHIE COUNTY. OTHERWISE
RAIN FREE WEATHER IS EXPECTED ACROSS MOST OF THE REGION THE
REMAINDER OF THE NIGHT. THE LATEST NAM AND HRRR MODELS CONTINUE TO
INDICATE THE POSSIBILITY OF A FEW SHOWERS AND THUNDERSTORMS MOVING
INTO PORTIONS OF NORTHEAST AR AND THE MO BOOTHEEL LATE TONIGHT
AHEAD OF A WEAK UPPER LEVEL SHORT WAVE EMBEDDED IN NORTHWEST FLOW
ALOFT...THIS IS ALREADY INDICATED IN THE EARLIER FORECAST.
SURFACE DEW POINTS HAVE REALLY INCREASED FROM RECENT DAYS AND ARE
PRESENTLY MAINLY IN THE LOWER AND MIDDLE 70S ACROSS MOST OF THE
AREA. THIS WILL MAKE FOR A WARMER NIGHT. ADDED PATCHY FOG WITH
DECREASING TEMPERATURE AND DEW POINT DEPRESSIONS ALONG WITH LIGHT
WINDS.
UPDATED GRIDS AND GRIDS WILL BE SENT SOON.
JCL
PREV DISCUSSION... /ISSUED 345 PM CDT TUE JUL 22 2014/
CURRENTLY...A WEAK UPPER LOW LOCATED ALONG THE NORTHERN GULF
COAST IS RETROGRADING SLOWLY. MEANWHILE TO THE NORTH AN UPPER
RIDGE EXTENDS INTO THE MID MISSISSIPPI VALLEY. DEEPER MOISTURE
ASSOCIATED WITH THE UPPER LOW HAS MOVED INTO NORTH MISSISSIPPI AND
INTO AREAS NEAR THE TENNESSEE RIVER WHERE THE AIRMASS IS FAIRLY
UNSTABLE WITH SBCAPES AROUND 2500 J/KG. AS A RESULT ISOLD SHOWERS
AND THUNDERSTORMS HAVE DEVELOPED IN THOSE AFOREMENTIONED AREAS.
ELSW SKIES ARE PARTLY TO MOSTLY SUNNY. TEMPS RANGE FROM THE MID
80S AND NE MS TO AROUND 90 ELSW.
TONIGHT...THE UPPER LOW WILL CONTINUE TO RETROGRADE AND WEAKEN
OVERNIGHT. ISOLD SHOWERS AND THUNDERSTORMS ACROSS NE MISSISSIPPI AND
ALONG THE TN RIVER WILL DISSIPATE WITH LOSS OF HEATING EARLY THIS
EVENING. OTRW EXPECT A QUIET AND MILD NIGHT WITH TEMPS A FEW
DEGREES WARMER THAN LAST NIGHT SINCE SURFACE DEWPOINTS HAVE
INCREASED A BIT IN THE LAST 24 HOURS. LATER TONIGHT A COLD FRONT
WILL START TO MOVE INTO THE MIDDLE MISSISSIPPI VALLEY WHICH WILL
TRIGGER SHOWERS AND THUNDERSTORMS ACROSS MISSOURI. SOME OF THESE
COULD SNEAK INTO NE ARKANSAS BY MORNING SO ADDED A SMALL POP
THERE.
WEDNESDAY AND WEDNESDAY NIGHT...THE UPPER RIDGE BRIEFLY SNEAKS IN
AHEAD OF APPROACHING COLD FRONT ALLOWING FOR A WARM AND MUGGY DAY
FOR THE MIDSOUTH. MEANWHILE THE WEAK UPPER LOW ALONG THE NORTHERN
GULF COAST WILL PERSIST AND MAY HELP TRIGGER A FEW SHOWERS AND
THUNDERSTORMS ACROSS NORTH MISSISSIPPI. MORE IMPORTANTLY BY
AFTERNOON A COLD FRONT WILL BE APPROACHING NORTHERN AREAS OF THE
MIDSOUTH WITH CHANCES FOR SHOWERS AND THUNDERSTORMS. THE FRONT
WILL CONTINUE TO PUSH SOUTH THROUGH THE AREA WEDNESDAY NIGHT WITH
CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUING. THE AIRMASS WILL
BE QUITE UNSTABLE AHEAD OF THE FRONT AND SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED WITH THE BEST CHANCES ACROSS THE
NORTHERN TIER. A FEW STRONG TO SEVERE STORMS ARE POSSIBLE WITH
DAMAGING WINDS THE MAIN THREAT WEDNESDAY AFTERNOON INTO WEDNESDAY
NIGHT. BY LATE WEDNESDAY NIGHT THE FRONT WILL BE LOCATED ACROSS
NORTHERN MISSISSIPPI AND COOLER/DRIER AIR WILL FILTER INTO
NORTHERN AREAS WITH TEMPS DROPPING INTO THE 60S.
THURSDAY THROUGH SATURDAY...THE COLD FRONT WILL EXIT NORTH
MISSISSIPPI IN THE MORNING AND HIGH PRESSURE WILL BUILD IN WITH A
LESS HUMID AIRMASS AND COOLER TEMPS. BELOW NORMAL TEMPS ARE
EXPECTED WITH HIGHS ON THURSDAY IN THE 80S AND LOWS THURSDAY NIGHT
IN THE 60S. TEMPS WILL CLIMB FRIDAY AND SATURDAY AS UPPER RIDGING
BUILDS IN. HIGHS WILL APPROACH 90 ON FRIDAY AND LOWER 90S ON
SATURDAY. CUT MEX TEMPS A FEW DEGREES SINCE IT HAS BEEN TOO WARM
ALL SUMMER.
SATURDAY NIGHT THROUGH SUNDAY NIGHT...UPPER RIDGE STARTS TO
WEAKEN SATURDAY NIGHT AND WEAK NORTHWEST FLOW DEVELOPS WITH A
BOUNDARY LOCATED TO THE NORTH OF THE AREA. THIS COULD BE AN MCS
SCENARIO. BY SUNDAY AND SUNDAY NIGHT THE EASTERN U.S. TROF
STRENGTHENS ONCE AGAIN AS MORE ENERGY DIPS SOUTH FROM CANADA. THIS
DRIVES A COLD FRONT SOUTH THROUGH THE AREA SUNDAY AND SUNDAY
NIGHT. EXPECT CHANCES FOR SHOWERS AND THUNDERSTORMS FOLLOWED BY
COOLER AND DRIER WEATHER BY EARLY NEXT WEEK. TEMPS LOOKS TO BE
WELL BELOW NORMAL MONDAY INTO MUCH OF NEXT WEEK.
SJM
&&
.AVIATION...06Z TAF CYCLE
MAINLY VFR CONDITIONS WILL CONTINUE FOR MUCH OF THE FORECAST
PERIOD. SOME AREAS OF FOG ARE EXPECTED TO DEVELOP OVERNIGHT WHICH
MAY REDUCE VISIBILITIES TO MVFR OR EVEN IFR LEVELS. A FEW
THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS THE FORECAST AREA
WEDNESDAY AFTERNOON AND EVENING BUT COVERAGE APPEARS TO BE LIMITED
SO HAVE NOT MENTIONED IN TAFS AT THIS TIME. WINDS WILL BE LIGHT
AND MAINLY FROM THE SOUTHWEST FOR MUCH OF THE FORECAST PERIOD BUT
WILL START TO SHIFT TO THE NORTHWEST WEDNESDAY EVENING. &&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1152 PM CDT TUE JUL 22 2014
.AVIATION...
/06Z TAFS/
VFR conditions to prevail across West Central Texas terminals
through the period. A veil of high clouds will spread across the
area from storms across Mexico, but should not effect aviation
concerns. Light east and southeast winds should continue.
&&
.PREV DISCUSSION... /ISSUED 615 PM CDT Tue Jul 22 2014/
AVIATION...
/00Z TAFS/
A few very high based, very isolated, showers and thunderstorms
developing across West Central Texas. Radar trends suggest that the
Junction and Sonora sites, KJCT and KSOA, would be the only 2 that
might be affected by one of the storms, and even that would be highly
unlikely. Thus, will not mention in the terminal forecast at this
time. Will monitor and update as needed. Otherwise, VFR conditions
and east to southeast winds should continue.
PREV DISCUSSION... /ISSUED 330 PM CDT TUE JUL 22 2014/
SHORT TERM...
(Tonight and Wednesday)
A strong subtropical ridge remains anchored over the southern
Rockies this afternoon with 500 mb heights approaching 600 dam at
the center of the anticyclone. Isolated thunderstorms have developed
over portions of West TX, basically between Lubbock and San Angelo,
moving southwest toward the Permian Basin. A few cells have
developed within the CWA from near Sweetwater to Sterling City.
Surface temperatures approaching 100 degrees have effectively
removed the cap, tapping into sufficient instability to support
thunderstorms. SPC mesoanalysis from the RAP indicates MLCAPE values
on the order of 1500 J/kg. With weak winds aloft, ordinary cells
will be the convective mode with a classic microburst profile in
place per point soundings. Isolated thunderstorms were carried
through 10 PM generally west of a line from Sweetwater to Mertzon.
Otherwise, we`ll see light winds overnight with temperatures falling
into the low to mid 70s by sunrise. Any thunderstorms lingering into
the evening hours should quickly dissipate by sunset. Temperatures
will again warm to near 100 degrees Wednesday afternoon with light
winds from a generally easterly direction.
Johnson
LONG TERM...
(Wednesday Night through Tuesday)
An upper ridge centered over northern New Mexico and the northern
Panhandle and extending north into south-central Canada will
continue to minimize our precipitation chances while giving us above
normal temperatures through the coming weekend. A developing upper
trough over the eastern half of then nation will displace the upper
ridge to the west through the by the beginning of next week. As the
upper ridge moves west there will be some relief from the unseasonal
heat as afternoon highs drop from the upper 90s and triple digits
down to the mid and upper 90s beginning next Monday. Models are
indicating a frontal boundary moving as far south as the Red River
Valley on Monday may provide a focus for some convective activity.
At this time the best chances of rainfall would be north of the
forecast area with a slight chance of some activity moving south
into at least our northern CWA. The models are also showing a TUTT
low mowing west over deep south Texas which should keep any
associated rainfall south of our area. In any event, given the
inherent uncertainty in the models this far out, will keep the
forecast dry at this time.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 74 99 74 100 74 / 0 5 5 5 5
San Angelo 73 100 71 101 72 / 5 5 5 10 5
Junction 71 98 71 98 72 / 5 5 5 10 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
858 PM CDT THU JUL 24 2014
.UPDATE...
IT/S LOOKING PRETTY QUIET ACROSS THE FORECAST AREA FOR TONIGHT.
THE GENESIS AREA FOR THUNDERSTORMS WILL BE ALONG THE WESTERN SIDE
OF AN ORPHANED COLD POOL LEFT OVER FROM EARLIER CONVECTION OVER
MN AND IOWA. THE LOW LEVEL JET IS INCREASING ACROSS THE CENTRAL
PLAINS AND WILL IMPINGE ON THIS COLD POOL AFTER MIDNIGHT RESULTING
IN A LINE OF SHOWERS AND STORMS DEVELOPING WELL UPSTREAM OF
WISCONSIN. I LIKE THE LATEST HRRR TRENDS AND OTHER HI RES MODELS
FROM EARLIER TODAY. THEY SHOW THE PRECIP MOVING EAST...BUT THEN
TAKING A DIVE TO THE SOUTH/SOUTHEAST WITH TIME...CONSISTENT WITH
CORFIDI VECTORS AND THE BETTER FORCING WITH THE LOW LEVEL JET
TRENDS. THE AIR MASS OVER THE FORECAST AREA IS QUITE DRY AND IT/S
NOT EXPECTED TO REALLY MOISTEN UP UNTIL FRI AFTERNOON. SO THIS
INITIAL CONVECTION MAY JUST FIZZLE AS IT MOVES IN TOWARD 12Z
FRI...WITH THE BETTER ACTION MOVING ACROSS EASTERN IOWA AND
POSSIBLY ILLINOIS. CURRENT RADAR AND THE HRRR SHOWS A VERY
ELEVATED BAND OF SHOWERS OVER NCNTRL WI MOVING SOUTHEAST. THIS
LOOKS TO BE WITH SOME WARM ADVECTION AND COULD EXPAND INTO THE
FORECAST AREA LATER ON. CONFIDENCE IS VERY LOW AND AT THIS POINT
WILL IGNORE IT FOR NOW.
ONLY ADJUSTMENT TO THE FORECAST TONIGHT IS TO DELAY THE PRECIP
INTO THE WEST A FEW HOURS...OTHERWISE NOT MUCH NEED FOR
ADJUSTMENTS AT THIS POINT GIVEN LIMITED NEW DATA.
&&
.AVIATION/06Z TAFS/...
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. THERE IS A CHANCE
OF THUNDERSTORMS AFTER ABOUT 15Z AT KMSN...BUT THIS WILL LIKELY BE
FROM A DIMINISHING LINE OF STORMS ARRIVING FROM THE WEST. WILL
HOLD OFF ON MENTION STORMS UNTIL FRIDAY AFTERNOON...AND AT THIS
POINT IT WILL ONLY BE VICINITY TERMINOLOGY. THERE IS GROWING
EVIDENCE THAT PRECIP WILL STAY MOSTLY SOUTH AND WEST OF THE
FORECAST AREA UNTIL FRIDAY EVENING.
&&
.PREV DISCUSSION... /ISSUED 344 PM CDT THU JUL 24 2014/
SHORT TERM...
TONIGHT AND FRIDAY...FORECAST CONFIDENCE LOW.
PLAN ON CLEAR SKIES AND LIGHT WINDS ACROSS SOUTHERN WI THIS
EVENING. LOWS WILL BE IN THE MID 50S TO AROUND 60.
SHOWERS AND THUNDERSTORMS SHOULD DEVELOP OVER SOUTH CENTRAL
MN AROUND MIDNIGHT AND SLIDE SOUTHEAST ALONG THE 850MB TEMP GRADIENT
AND WITH THE CORFIDI VECTORS. THESE MAY CLIP SOUTHWEST WISCONSIN
LATE TONIGHT INTO FRIDAY MORNING. THE LOW LEVELS WILL REMAIN DRY
THROUGH THE NIGHT...SO IT IS A QUESTION OF HOW STRONG THE ELEVATED
THUNDERSTORMS APPROACHING THE AREA END UP BEING TO DETERMINE IF THEY
CAN SATURATE FROM THE TOP DOWN AND PRECIPITATE. OVERALL FORCING
APPEARS QUITE WEAK OVER SOUTHERN WI IN THE ABSENCE OF A STRONG
SHORTWAVE OR FAVORABLE POSITION OF THE UPPER JET. I
CONTINUED THE LIKELY POPS FOR SOUTH CENTRAL WI FRI MORNING DUE TO
THE 12Z SYNOPTIC SCALE MODELS. HOWEVER...I DO NOT HAVE VERY MUCH
CONFIDENCE IN THIS GIVEN THE WRF-ARW AND WRF-NMM MODELS AND EVEN
EARLY SIGNS IN THE HRRR.
THE NOSE OF THE LOW LEVEL JET /LLJ/ WILL POINT INTO SOUTH CENTRAL MN
AROUND MIDNIGHT TONIGHT AND THEN VEER SOUTHEAST INTO SOUTH CENTRAL
WI MIDDAY FRIDAY. THE LLJ WILL BE THE MAIN DRIVER FOR ANY
CONVECTION AND IT ALL LOOKS ELEVATED. MODELS ARE ALL OVER THE PLACE
FOR PRECIP PLACEMENT FRIDAY AFTERNOON. PERSISTENT 850MB WARM AIR
ADVECTION...THE NOSE OF THE LLJ AND WEAK SHORTWAVE ACTIVITY COULD BE
ENOUGH TO DEVELOP SOME SCATTERED SHOWERS AND THUNDERSTORMS DURING
THE AFTERNOON. ELEVATED CAPE COULD BE UP TO 1000 J/KG WITH DECENT
SHEAR. IF STORMS DEVELOP...CANNOT RULE OUT SOME HALF INCH TO ONE
INCH HAIL.
FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE...HIGH
THE UPPER FLOW BECOMES ZONAL WITH A WEST/NORTHWEST FLOW AS A 100
KNOT JET MAX OVER THE NORTHERN PLAINS PUSHES EAST SOUTHEAST
TOWARD THE WISCONSIN/ILLINOIS BORDER. WEAK UPPER DIVERGENCE
EXISTS ACROSS SOUTHERN WISCONSIN.
THE 700 MB THERMAL RIDGE EXTENDS INTO SOUTHERN WISCONSIN FRIDAY
NIGHT...THEN SAGGING SOUTH ACROSS NORTHERN ILLINOIS SATURDAY.
WEAK 700 MB UPWARD MOTION MOVES ACROSS SOUTHERN WISCONSIN FRIDAY
NIGHT ALONG WITH A SUBTLE MID LEVEL SHORTWAVE. 700 MB RH DRIES
FRIDAY NIGHT AND IS VERY LOW SATURDAY. 850 MB RH IS SATURATED
FRIDAY NIGHT WITH DEW POINTS OF 16 TO 18 CELSIUS AND DRIES FROM
THE WEST SATURDAY. SOUTHEAST WISCONSIN IS AT THE NOSE OF THE
40 KNOT 850 MB LOW LEVEL JET FRIDAY EVENING BEFORE IT SAGS SOUTH.
THE NAM BRINGS SOME PRECIPITATION TO THE SOUTHEAST OVERNIGHT. THE
NAM HAS ALMOST 3000 JOULES/KG OF ELEVATED CAPE LIFTING FROM AROUND
870 MB. NSHARP HAIL PARAMETERS INDICATE A SEVERE POTENTIAL FRIDAY
NIGHT. THE HAIL PARAMETERS INCREASE SATURDAY...ALTHOUGH A STRONG
CAP AT 825 MB WOULD LIKELY PREVENT ANY DEEP MOIST CONVECTION.
SATURDAY NIGHT AND SUNDAY...FORECAST CONFIDENCE...HIGH
THE ZONAL FLOW BEGINS TO BREAK DOWN AS A MID/UPPER LEVEL
SHORTWAVE BEGINS TO DROP SOUTHEAST INTO NORTHERN MINNESOTA
SATURDAY NIGHT....AND INTO THE WESTERN GREAT LAKES SUNDAY. THE
UPPER DIVERGENCE AND 700 MB CONVERGENCE INCREASES AGAIN SUNDAY.
NSHARP HAIL PARAMETERS STILL INDICATE A SEVERE POTENTIAL SUNDAY
MORNING AS THE CAP WEAKENS. NAM INCREASES PRECIPITATION DURING THE
DAY SUNDAY.
LONG TERM...
MONDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE...HIGH
THE SHORTWAVE OVER THE GREAT LAKES CONTINUES TO DIG ACROSS THE
EASTERN GREAT LAKES MONDAY...AND SOUTH ACROSS THE EASTERN U.S.
TUESDAY AND TUESDAY NIGHT AND WEDNESDAY.
HIGH PRESSURE BECOMES CENTERED OVER THE EASTERN PLAINS AND UPPER
MISSISSIPPI VALLEY ALTHOUGH THE COOL AIR ALOFT COULD BRING
DIURNAL SHOWERS...ESPECIALLY TUESDAY AND WEDNESDAY.
THURSDAY...FORECAST CONFIDENCE...MEDIUM
A SECOND SHORTWAVE DROPS INTO THE UPPER MISSISSIPPI VALLEY
WEDNESDAY NIGHT INTO THURSDAY...RETROGRATING THE TROUGH BACK
ACROSS THE GREAT LAKES.
THIS BRINGS MORE DIURNAL PRECIPITATION CHANCES AND CONTINUES THE
RATHER COOL TEMPERATURES.
AVIATION/00Z TAFS/...
VFR CONDITIONS THROUGH TONIGHT. WARM ADVECTION AHEAD OF APPROACHING
SHORTWAVE TROUGH BRINGS INCREASING PCPN CHANCES TO MAINLY THE FAR
WESTERN FORECAST AREA LATE TONIGHT INTO FRIDAY MORNING WITH A
DIMINISHING THUNDERSTORM COMPLEX. ANY PRECIP SHOULD REMAIN TO THE
SOUTHWEST OF MADISON.
THERE IS A GENERAL CHANCE FOR SHOWERS AND THUNDERSTORMS FRIDAY
AFTERNOON FOR THE WHOLE AREA. OVERALL WEAK FORCING...BUT MODERATE
INSTABILITY COULD LEAD TO SMALL HAIL IF THUNDERSTORMS DEVELOP.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...DAVIS
TONIGHT/FRIDAY AND AVIATION/MARINE...MRC
FRIDAY NIGHT THROUGH THURSDAY...HENTZ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
849 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 849 PM CDT THU JUL 24 2014
HAVE DRIED OUT THE FORECAST FOR THE REST OF THE EVENING WITH
SUBSIDENCE IN THE WAKE OF THE AFTERNOON/EARLY EVENING COMPLEX IN
CONTROL. HOWEVER...SOMETHING TO MONITOR IS A SHOWER DEVELOPING
WEST OF ALEXANDRIA MN. ATTENTION OTHERWISE FOCUSES TO A CLUSTER
OF STORMS OVER NORTHWEST SOUTH DAKOTA. 24.23Z HRRR AND 25.00Z RAP
TAKE THIS CLUSTER ACROSS NORTHERN SOUTH DAKOTA...BASICALLY
CROSSING THE UPPER RIDGE AXIS THERE. AS THE COMPLEX APPROACHES
NORTHEAST SOUTH DAKOTA...A LOW LEVEL JET INCREASE IS EXPECTED
ALONG WITH VEERING TO POINT TOWARDS THE FORECAST AREA. IN
FACT...THIS INCREASE AND TURNING IS ALREADY TAKING PLACE AT FSD
WHERE SOUTH-SOUTHWEST 45 KT 850MB WINDS EXIST ON THEIR RADAR. A
BAND OF SHOWERS AND STORMS IS LIKELY TO INITIATE ON THE NOSE OF
THE LOW LEVEL JET...EVENTUALLY PROGRESSING INTO WESTERN PORTIONS
OF THE FORECAST AREA BETWEEN 09-10Z AND PERHAPS TO THE MS RIVER BY
12Z.
HAVE UPDATED PRECIPITATION CHANCES AND QPF TO REFLECT THE
AFOREMENTIONED SCENARIO. SOME HINTS IN THE HRRR THAT THE STORMS
WITHIN THE SHOWERS MAY FALL APART AROUND 12Z. IF THIS TREND
CONTINUES...MAY HAVE TO PULL OR AT LEAST REDUCE THUNDER CHANCES.
UPDATE ISSUED AT 550 PM CDT THU JUL 24 2014
HAVING SOME SERIOUS CONCERNS WITH THE PRECIPITATION CHANCES THIS
EVENING...AND POSSIBLY OVERNIGHT TOO.
CURRENTLY...WATER VAPOR LOOP AND RADAR IMAGERY SHOWED A COMPLEX
OF SHOWERS AND STORMS DROPPING SOUTH...NOW INTO NORTHWEST AND
NORTH CENTRAL IOWA. THE EASTWARD PROGRESSION OF THE PRECIPITATION
TOWARDS THE FORECAST AREA HAS COME TO A HALT DUE TO THE COMPLEX
MOTION...ALONG WITH PLENTIFUL DRY AIR OVER THE FORECAST AREA.
2030Z TAMDAR SOUNDING FROM MSP SHOWED 10C OR HIGHER DEWPOINT
DEPRESSIONS FROM 770-600MB AND A DEEP INVERTED-V AT 800MB.
SUBSIDENCE IN THE WAKE OF THIS COMPLEX SHOWING UP AS A SIGNIFICANT
AREA OF CLEARING OVER WEST-CENTRAL MN...DRYING IN THE SAME
LOCATION ON WATER VAPOR...AND SURFACE PRESSURE FALLS UP TO 2
MB/HR.
ITS TOUGH FINDING A MODEL WITH A GREAT HANDLE ON THIS CURRENT
COMPLEX. THE 24.21Z RAP...24.19Z HRRR AND 24.18Z GFS SEEM TO BE
THE BEST AND ALL THREE SUGGEST THAT THE EVENING MAY NOW END UP
DRY ACROSS THE FORECAST AREA. THIS SEEMS REASONABLE AS THE
SUBSIDENCE COMES INTO THE FORECAST AREA IN THE WAKE OF THE
COMPLEX. IN FACT...GIVEN THE CLEARING UPSTREAM...ITS POSSIBLE
THAT CLEARING COMES INTO THE AREA. NEXT CONCERN THEN TURNS TO THE
OVERNIGHT CONVECTION POSSIBILITIES. WITH SUBSIDENCE AND COLD POOL
IN PLACE OVER MN AND NORTH CENTRAL IOWA...WHEN THE LOW LEVEL JET
INCREASES TONIGHT...THE CONVECTION MAY END FIRING MORE ALONG THE
WESTERN MN/IOWA BORDER. THE AFOREMENTIONED MODELS ALONG WITH THE
24.12Z ECMWF AND EVEN TO SOME DEGREE THE 24.18Z NAM ALL SHOW THAT
IDEA. IF THE CONVECTION DEVELOPS AN MCV...THEN THE CONVECTION WILL
DROP SOUTHEAST AND STAY MOSTLY WEST OF THE FORECAST AREA. THIS IS
WHAT THE 24.18Z NAM AND 24.12Z HIRES-ARW SUGGESTED. HOWEVER...IF
NO MCV FORMS...A FRONTOGENETICAL BAND OF SHOWERS AND EMBEDDED
STORMS WOULD MOVE WEST TO EAST INTO THE FORECAST AREA AFTER
07Z...PERHAPS REACHING THE MS RIVER BY 12Z.
FOR NOW...HAVE TRENDED PRECIPITATION CHANCES DOWN SOME FOR THE
EVENING AND FURTHER DECREASES ARE POSSIBLE. HAVE NOT ADJUSTED THE
OVERNIGHT YET...BUT COULD SEE A NEED TO DECREASE PRECIPITATION
CHANCES ALONG/EAST OF THE MS RIVER. NEEDLESS TO SAY THE
PRECIPITATION CHANCES FOR TONIGHT IS A FLUID SITUATION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 320 PM CDT THU JUL 24 2014
MAIN FORECAST PROBLEM WAS THE STORMS/WEATHER MOVING IN OVERNIGHT
INTO FRIDAY MORNING.
A TALE OF TWO AIR MASSES ACROSS THE REGION THIS MORNING IN THE
OBSERVATIONAL DATA. 24.12Z RAOBS SHOWING STEEP 700-500MB LAPSE RATES
OVER THE WESTERN DAKOTAS /9C PER KM/ AND MID-LEVEL SATURATION
OCCURRING ON THE EASTERN EDGE OF THE DEEPER N-S MOIST PLUME IN
PLACE. PRECIPITABLE WATER /PWAT/ VALUES AT KBIS/KABR BOTH ARE BOTH
OVER 125 PERCENT THIS MORNING. KBIS AND KABR SOUNDINGS BOTH SHOW
SATURATION AROUND 700MB WITH 500-1000J/KG OF ELEVATED CAPE ABOVE
700MB. EAST OF THE MOIST PLUME...STABILITY REIGNS WITH 5-6C/KM
500-700MB LAPSE RATES AND BELOW NORMAL PWAT VALUES /65 PERCENT/ AT
KMPX. THIS GRADIENT AND MOISTURE TRANSPORT CONVERGENCE OVER THE
DAKOTAS/MN BORDER AT 16Z MATCHED WELL WITH THE MORNING STORMS AND
WEATHER IN THE DAKOTAS. THIS ALL ENHANCED BY A VERY VISIBLE
SHORTWAVE TROUGH SEWRD OF KBIS AND ANOTHER NORTH OF THE MT/ND/SRN
CANADA BORDER.
AS THE LARGE SCALE SHIFTS OVER NORTH AMERICA AND THE LONG WAVE
TROUGH OVER THE EAST WEAKENS...FLAT RIDGING BUILDS ACROSS THE
NORTHERN STATES /THROUGH SATURDAY/. THIS WILL PROMOTE WARMING AND
RICHER MOISTURE TO MOVE INTO THE REGION FOR A PERIOD...BEFORE
REAMPLIFICATION OF THE TROUGH OVER THE ERN CONUS OCCURS /SUNDAY/.
BEGINNING OVERNIGHT...THE DAKOTAS AIR MASS WILL ADVECT EASTWARD
AND INTO THE AREA. THIS AIRMASS IS CHARACTERIZED BY HIGHER
MOISTURE BUT ALSO VERY WARM TEMPERATURES ALOFT AS AN ELEVATED
MIXED LAYER MOVES IN. WHILE THIS HAS STEEP MID-LEVEL LAPSE
RATES...THE 700MB TEMPERATURES WARM FROM 8C TO 12-14C
FRIDAY...PROVIDING A STOUT CAPPING INVERSION TO SURFACE BASED
CONVECTION BY AFTERNOON. THIS TRANSLATES TO A 600 J/KG SBCIN. THIS
CAP BUILDING HAS VERY GOOD CONSENSUS AMOUNT THE DETERMINISTIC
MODELS...AND HAVE LOWERED RAIN CHANCES FRIDAY AFTERNOON
ACCORDINGLY.
PRIOR TO THE ELEVATED MIXED LAYER BUILDING IN FRIDAY...LOW-LEVEL
WARM ADVECTION AND MOISTURE TRANSPORT INCREASES WITH HEIGHT FALLS
AND INCREASED SOUTHERLY FLOW OVERNIGHT. THIS EVENING THERE IS SOME
SIGNAL FOR MID-LEVEL MOISTURE TRANSPORT CONVERGENCE /700MB/ TO
MOVE IN FROM THE WEST DURING THE EVENING AND LAPSE RATES WOULD SAY
SOME MID-LEVEL TOWERING CU COULD DEVELOP SOME SHOWERS
/100-300J/KG MUCAPE/. HAVE BEEN MONITORING THE CONVECTION ENTERING
WESTERN MN AND WHILE MUCAPE VALUES HAVE INCREASED A FEW HUNDRED
FROM 15-18Z...MUCH OF MN IS STILL QUITE STABLE. HOWEVER...THE
NORTHERN SIDE SEEMS TO BE TIED TO THE 700 MB TRANSPORT CONVERGENCE
AND SHORTWAVE TROUGH APPROACHING FARGO. WOULD EXPECT ECHO TO
WEAKEN AS IT MOVES TOWARD I-35...ALTHOUGH THERE IS WEAK
FORCING...THE AIR MASS IS VERY DRY. WILL HAVE TO MONITOR...BUT
TIMING LOOKS TO FIT THE EVENING INCREASE OF PRECIPITATION CHANCES.
BY MIDNIGHT...AS THE RIDGE BUILDS EAST...MOISTURE TRANSPORT AND A 40-
50KT LOW-LEVEL JET AT 850 MB FEED THE EASTERN EDGE OF THE MOISTURE
PLUME UP THE . BY 09Z...A MESOSCALE CONVECTIVE SYSTEM IS EXPECTED
TO ENTER THE WESTERN FORECAST AREA ON VERY STRONG MOISTURE
TRANSPORT CONVERGENCE AT 850 MB /50KTS DECREASING TO 15 KTS...KDSM
TO KLSE/. THIS SIGNAL IS VERY CONSISTENT AMONG THE 24.12Z MODELS
AND LATEST RAP GUIDANCE. CORFIDI VECTORS SUGGEST SOUTHEAST
MOVEMENT TO THE STRONGER CONVECTIVE ELEMENTS...AND THIS COULD POSE
SOME PROBLEMS WITH THE COMPLEX MISSING TO THE SOUTHWEST. WITH THE
MOISTURE TRANSPORT CONVERGENCE INTO THE HEART OF THE FORECAST
AREA...WOULD THINK A MISS IS PROBABLY UNLIKELY. THIS WOULD FAVOR
THE AREAS SOUTHWEST OF I-94...ESPECIALLY INTO NORTHEAST IOWA AND
LITTLE CHANGE TO THE RAIN CHANCES WERE MADE.
PRECIPITABLE WATER VALUES INCREASE RAPIDLY OVERNIGHT WITH OVER
1.75 INCHES IN THE AREA BY MORNING AND WARM CLOUD DEPTHS OF 4 KM.
THUS HEAVY RAINFALL RATES WILL OCCUR IN THE SYSTEM...BUT MANY
AREAS CAN USE THE RAINS. SOME BRIEF CITY FLOODING IS POSSIBLE.
ISOLATED HAIL AND GUSTY WINDS HAVE BEEN ADDED TO AREAS WEST OF THE
MISS RIVER IN THE HAZ WEATHER OUTLOOK DUE TO THE MAGNITUDE OF
CONVERGENCE/FORCING AND ABOUT 1500 J/KG OF MUCAPE. SPC HAS ALSO
SHIFTED THEIR DAY 1 CONVECTIVE OUTLOOK TO NEAR OUR WESTERN
FORECAST AREA EDGE...WHICH IS APPROPRIATE. CAPPING SHOULD THEN
BUILD IN AND THE SYSTEM MOVES EAST/SOUTHEAST IN THE AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 320 PM CDT THU JUL 24 2014
FRIDAY NIGHT POSES AN INTERESTING PROBLEM IN SRN WISCONSIN AS THE
CAP IS STILL FULLY IN PLACE WITH NO SURFACE BASED CONVECTION
ALLOWED PER ALL GUIDANCE /600 SBCIN AND 700MB TEMPS NEAR 14C/.
YET A HANDFUL OF DETERMINISTIC MODELS CONTINUE A SIGNAL OF QPF
ACROSS SRN WISCONSIN IN THE EVENING. HAVE KEPT A SMALL RAIN CHANCE
THERE AS IT WOULD BE SOME MID-LEVEL INSTABILITY THAT WOULD HAVE TO
BE TAPPED NORTH OF THE SURFACE LOW SHIFTING THROUGH ERN IA. THE
24.12Z NAM DOES HAVE SOME 900-800MB FRONOTGENESIS WORKING WITHIN
THE CAPPED AREA...AND POSSIBLY SOME ISENTROPIC LIFT GENERATES
STABLE SHOWERS. PREFER THE 24.12Z NAM WITH RAINFALL SOUTH OF THE
FORECAST AREA...BUT HAVE KEPT A SLIGHT CHANCE OF RAIN TO COVER
THIS SITUATION FRIDAY EVENING.
A DRYING TREND THEN IN NORTHWEST FLOW AFTER MIDNIGHT...THROUGH
SATURDAY PROVIDES A VERY NICE DRY DAY. THE HIGH PRECIPITABLE WATER
AIRMASS SHOULD PUSH SOUTH TO NEAR I-80 CORRIDOR.
STRONG QG CONVERGENCE FORCING MOVES IN SUNDAY WITH THE STRONG
TROUGH MOVING THROUGH MN/WI AS THE LONG WAVE AMPLIFIES AGAIN OVER
THE EASTERN CONUS. FORCING COMES IN LATER SATURDAY NIGHT AND IS
STRONGEST SUNDAY WITH SOME INSTABILITY. HAVE INCREASED RAIN
CHANCES FOR SUNDAY. RAIN CHANCES MAY NEED TO BE PULLED FURTHER
SOUTHWEST AS WELL DEPENDING ON THE WAVE TRACK. A CLOUDY BREEZY
SHOWERY DAY FOR MOST AREAS IT SEEMS.
MONDAY THROUGH THURSDAY HAVE BELOW NORMAL TEMPERATURES AND MOSTLY
DRY WEATHER UNDER THE INFLUENCE OF THE LONGWAVE TROUGH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 631 PM CDT THU JUL 24 2014
THE AVIATION FORECAST HAS BECOME MORE UNCERTAIN...PRIMARILY WITH
SHOWER AND THUNDERSTORM CHANCES. MUCH OF THIS UNCERTAINTY STEMS
FROM A COMPLEX OF SHOWERS AND EMBEDDED THUNDERSTORMS THAT RECENTLY
DROPPED SOUTH THROUGH WESTERN MN AND IA.
BOTH TAF SITES CURRENTLY SIT IN A PLENTIFUL DRY AIRMASS WHICH
SHOULD KEEP CONDITIONS VFR THROUGH THE EVENING. THERE COULD BE
SOME BRIEF GUSTS AT RST OF 20-25 KT PRIOR TO 01Z AS THE DECAYING
PORTION OF THE COMPLEX MOVES THROUGH. DURING THE OVERNIGHT...
SHOWERS AND THUNDERSTORMS LOOK LIKELY TO FORM AGAIN IN MN AND IA
AND EVENTUALLY PROGRESS EAST-SOUTHEASTWARD THROUGH FRIDAY MORNING.
HOWEVER...WHERE THEY FORM AND IF THEY CAN DEVELOP INTO A COMPLEX
GREATLY AFFECTS THE TAFS. THE LOCATION MAY BE FARTHER WEST THANKS
TO THE CURRENT STORM COMPLEX...WHICH WOULD LEAN TO A BETTER CHANCE
THE TAF SITES STAY DRIER. THEREFORE...HAVE CHANGED THE -TSRA TO
VCTS AND REMOVED ANY LOWER CEILING POTENTIAL AT LSE. STILL
MAINTAINED THE MVFR VISIBILITY AT RST GIVEN THE HIGHER CHANCE FOR
PRECIPITATION TO OCCUR THERE VS LSE. ANY PRECIPITATION SHOULD MOVE
AWAY FROM THE TAF SITES BY 17Z WITH VFR CONDITIONS THEREAFTER.
WINDS COULD GET GUSTY AT RST AGAIN BRIEFLY IN THE LATE MORNING AND
AFTERNOON IN THE WAKE OF THE MORNING STORMS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
631 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 550 PM CDT THU JUL 24 2014
HAVING SOME SERIOUS CONCERNS WITH THE PRECIPITATION CHANCES THIS
EVENING...AND POSSIBLY OVERNIGHT TOO.
CURRENTLY...WATER VAPOR LOOP AND RADAR IMAGERY SHOWED A COMPLEX
OF SHOWERS AND STORMS DROPPING SOUTH...NOW INTO NORTHWEST AND
NORTH CENTRAL IOWA. THE EASTWARD PROGRESSION OF THE PRECIPITATION
TOWARDS THE FORECAST AREA HAS COME TO A HALT DUE TO THE COMPLEX
MOTION...ALONG WITH PLENTIFUL DRY AIR OVER THE FORECAST AREA.
2030Z TAMDAR SOUNDING FROM MSP SHOWED 10C OR HIGHER DEWPOINT
DEPRESSIONS FROM 770-600MB AND A DEEP INVERTED-V AT 800MB.
SUBSIDENCE IN THE WAKE OF THIS COMPLEX SHOWING UP AS A SIGNIFICANT
AREA OF CLEARING OVER WEST-CENTRAL MN...DRYING IN THE SAME
LOCATION ON WATER VAPOR...AND SURFACE PRESSURE FALLS UP TO 2
MB/HR.
ITS TOUGH FINDING A MODEL WITH A GREAT HANDLE ON THIS CURRENT
COMPLEX. THE 24.21Z RAP...24.19Z HRRR AND 24.18Z GFS SEEM TO BE
THE BEST AND ALL THREE SUGGEST THAT THE EVENING MAY NOW END UP
DRY ACROSS THE FORECAST AREA. THIS SEEMS REASONABLE AS THE
SUBSIDENCE COMES INTO THE FORECAST AREA IN THE WAKE OF THE
COMPLEX. IN FACT...GIVEN THE CLEARING UPSTREAM...ITS POSSIBLE
THAT CLEARING COMES INTO THE AREA. NEXT CONCERN THEN TURNS TO THE
OVERNIGHT CONVECTION POSSIBILITIES. WITH SUBSIDENCE AND COLD POOL
IN PLACE OVER MN AND NORTH CENTRAL IOWA...WHEN THE LOW LEVEL JET
INCREASES TONIGHT...THE CONVECTION MAY END FIRING MORE ALONG THE
WESTERN MN/IOWA BORDER. THE AFOREMENTIONED MODELS ALONG WITH THE
24.12Z ECMWF AND EVEN TO SOME DEGREE THE 24.18Z NAM ALL SHOW THAT
IDEA. IF THE CONVECTION DEVELOPS AN MCV...THEN THE CONVECTION WILL
DROP SOUTHEAST AND STAY MOSTLY WEST OF THE FORECAST AREA. THIS IS
WHAT THE 24.18Z NAM AND 24.12Z HIRES-ARW SUGGESTED. HOWEVER...IF
NO MCV FORMS...A FRONTOGENETICAL BAND OF SHOWERS AND EMBEDDED
STORMS WOULD MOVE WEST TO EAST INTO THE FORECAST AREA AFTER
07Z...PERHAPS REACHING THE MS RIVER BY 12Z.
FOR NOW...HAVE TRENDED PRECIPITATION CHANCES DOWN SOME FOR THE
EVENING AND FURTHER DECREASES ARE POSSIBLE. HAVE NOT ADJUSTED THE
OVERNIGHT YET...BUT COULD SEE A NEED TO DECREASE PRECIPITATION
CHANCES ALONG/EAST OF THE MS RIVER. NEEDLESS TO SAY THE
PRECIPITATION CHANCES FOR TONIGHT IS A FLUID SITUATION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 320 PM CDT THU JUL 24 2014
MAIN FORECAST PROBLEM WAS THE STORMS/WEATHER MOVING IN OVERNIGHT
INTO FRIDAY MORNING.
A TALE OF TWO AIR MASSES ACROSS THE REGION THIS MORNING IN THE
OBSERVATIONAL DATA. 24.12Z RAOBS SHOWING STEEP 700-500MB LAPSE RATES
OVER THE WESTERN DAKOTAS /9C PER KM/ AND MID-LEVEL SATURATION
OCCURRING ON THE EASTERN EDGE OF THE DEEPER N-S MOIST PLUME IN
PLACE. PRECIPITABLE WATER /PWAT/ VALUES AT KBIS/KABR BOTH ARE BOTH
OVER 125 PERCENT THIS MORNING. KBIS AND KABR SOUNDINGS BOTH SHOW
SATURATION AROUND 700MB WITH 500-1000J/KG OF ELEVATED CAPE ABOVE
700MB. EAST OF THE MOIST PLUME...STABILITY REIGNS WITH 5-6C/KM
500-700MB LAPSE RATES AND BELOW NORMAL PWAT VALUES /65 PERCENT/ AT
KMPX. THIS GRADIENT AND MOISTURE TRANSPORT CONVERGENCE OVER THE
DAKOTAS/MN BORDER AT 16Z MATCHED WELL WITH THE MORNING STORMS AND
WEATHER IN THE DAKOTAS. THIS ALL ENHANCED BY A VERY VISIBLE
SHORTWAVE TROUGH SEWRD OF KBIS AND ANOTHER NORTH OF THE MT/ND/SRN
CANADA BORDER.
AS THE LARGE SCALE SHIFTS OVER NORTH AMERICA AND THE LONG WAVE
TROUGH OVER THE EAST WEAKENS...FLAT RIDGING BUILDS ACROSS THE
NORTHERN STATES /THROUGH SATURDAY/. THIS WILL PROMOTE WARMING AND
RICHER MOISTURE TO MOVE INTO THE REGION FOR A PERIOD...BEFORE
REAMPLIFICATION OF THE TROUGH OVER THE ERN CONUS OCCURS /SUNDAY/.
BEGINNING OVERNIGHT...THE DAKOTAS AIR MASS WILL ADVECT EASTWARD
AND INTO THE AREA. THIS AIRMASS IS CHARACTERIZED BY HIGHER
MOISTURE BUT ALSO VERY WARM TEMPERATURES ALOFT AS AN ELEVATED
MIXED LAYER MOVES IN. WHILE THIS HAS STEEP MID-LEVEL LAPSE
RATES...THE 700MB TEMPERATURES WARM FROM 8C TO 12-14C
FRIDAY...PROVIDING A STOUT CAPPING INVERSION TO SURFACE BASED
CONVECTION BY AFTERNOON. THIS TRANSLATES TO A 600 J/KG SBCIN. THIS
CAP BUILDING HAS VERY GOOD CONSENSUS AMOUNT THE DETERMINISTIC
MODELS...AND HAVE LOWERED RAIN CHANCES FRIDAY AFTERNOON
ACCORDINGLY.
PRIOR TO THE ELEVATED MIXED LAYER BUILDING IN FRIDAY...LOW-LEVEL
WARM ADVECTION AND MOISTURE TRANSPORT INCREASES WITH HEIGHT FALLS
AND INCREASED SOUTHERLY FLOW OVERNIGHT. THIS EVENING THERE IS SOME
SIGNAL FOR MID-LEVEL MOISTURE TRANSPORT CONVERGENCE /700MB/ TO
MOVE IN FROM THE WEST DURING THE EVENING AND LAPSE RATES WOULD SAY
SOME MID-LEVEL TOWERING CU COULD DEVELOP SOME SHOWERS
/100-300J/KG MUCAPE/. HAVE BEEN MONITORING THE CONVECTION ENTERING
WESTERN MN AND WHILE MUCAPE VALUES HAVE INCREASED A FEW HUNDRED
FROM 15-18Z...MUCH OF MN IS STILL QUITE STABLE. HOWEVER...THE
NORTHERN SIDE SEEMS TO BE TIED TO THE 700 MB TRANSPORT CONVERGENCE
AND SHORTWAVE TROUGH APPROACHING FARGO. WOULD EXPECT ECHO TO
WEAKEN AS IT MOVES TOWARD I-35...ALTHOUGH THERE IS WEAK
FORCING...THE AIR MASS IS VERY DRY. WILL HAVE TO MONITOR...BUT
TIMING LOOKS TO FIT THE EVENING INCREASE OF PRECIPITATION CHANCES.
BY MIDNIGHT...AS THE RIDGE BUILDS EAST...MOISTURE TRANSPORT AND A 40-
50KT LOW-LEVEL JET AT 850 MB FEED THE EASTERN EDGE OF THE MOISTURE
PLUME UP THE . BY 09Z...A MESOSCALE CONVECTIVE SYSTEM IS EXPECTED
TO ENTER THE WESTERN FORECAST AREA ON VERY STRONG MOISTURE
TRANSPORT CONVERGENCE AT 850 MB /50KTS DECREASING TO 15 KTS...KDSM
TO KLSE/. THIS SIGNAL IS VERY CONSISTENT AMONG THE 24.12Z MODELS
AND LATEST RAP GUIDANCE. CORFIDI VECTORS SUGGEST SOUTHEAST
MOVEMENT TO THE STRONGER CONVECTIVE ELEMENTS...AND THIS COULD POSE
SOME PROBLEMS WITH THE COMPLEX MISSING TO THE SOUTHWEST. WITH THE
MOISTURE TRANSPORT CONVERGENCE INTO THE HEART OF THE FORECAST
AREA...WOULD THINK A MISS IS PROBABLY UNLIKELY. THIS WOULD FAVOR
THE AREAS SOUTHWEST OF I-94...ESPECIALLY INTO NORTHEAST IOWA AND
LITTLE CHANGE TO THE RAIN CHANCES WERE MADE.
PRECIPITABLE WATER VALUES INCREASE RAPIDLY OVERNIGHT WITH OVER
1.75 INCHES IN THE AREA BY MORNING AND WARM CLOUD DEPTHS OF 4 KM.
THUS HEAVY RAINFALL RATES WILL OCCUR IN THE SYSTEM...BUT MANY
AREAS CAN USE THE RAINS. SOME BRIEF CITY FLOODING IS POSSIBLE.
ISOLATED HAIL AND GUSTY WINDS HAVE BEEN ADDED TO AREAS WEST OF THE
MISS RIVER IN THE HAZ WEATHER OUTLOOK DUE TO THE MAGNITUDE OF
CONVERGENCE/FORCING AND ABOUT 1500 J/KG OF MUCAPE. SPC HAS ALSO
SHIFTED THEIR DAY 1 CONVECTIVE OUTLOOK TO NEAR OUR WESTERN
FORECAST AREA EDGE...WHICH IS APPROPRIATE. CAPPING SHOULD THEN
BUILD IN AND THE SYSTEM MOVES EAST/SOUTHEAST IN THE AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 320 PM CDT THU JUL 24 2014
FRIDAY NIGHT POSES AN INTERESTING PROBLEM IN SRN WISCONSIN AS THE
CAP IS STILL FULLY IN PLACE WITH NO SURFACE BASED CONVECTION
ALLOWED PER ALL GUIDANCE /600 SBCIN AND 700MB TEMPS NEAR 14C/.
YET A HANDFUL OF DETERMINISTIC MODELS CONTINUE A SIGNAL OF QPF
ACROSS SRN WISCONSIN IN THE EVENING. HAVE KEPT A SMALL RAIN CHANCE
THERE AS IT WOULD BE SOME MID-LEVEL INSTABILITY THAT WOULD HAVE TO
BE TAPPED NORTH OF THE SURFACE LOW SHIFTING THROUGH ERN IA. THE
24.12Z NAM DOES HAVE SOME 900-800MB FRONOTGENESIS WORKING WITHIN
THE CAPPED AREA...AND POSSIBLY SOME ISENTROPIC LIFT GENERATES
STABLE SHOWERS. PREFER THE 24.12Z NAM WITH RAINFALL SOUTH OF THE
FORECAST AREA...BUT HAVE KEPT A SLIGHT CHANCE OF RAIN TO COVER
THIS SITUATION FRIDAY EVENING.
A DRYING TREND THEN IN NORTHWEST FLOW AFTER MIDNIGHT...THROUGH
SATURDAY PROVIDES A VERY NICE DRY DAY. THE HIGH PRECIPITABLE WATER
AIRMASS SHOULD PUSH SOUTH TO NEAR I-80 CORRIDOR.
STRONG QG CONVERGENCE FORCING MOVES IN SUNDAY WITH THE STRONG
TROUGH MOVING THROUGH MN/WI AS THE LONG WAVE AMPLIFIES AGAIN OVER
THE EASTERN CONUS. FORCING COMES IN LATER SATURDAY NIGHT AND IS
STRONGEST SUNDAY WITH SOME INSTABILITY. HAVE INCREASED RAIN
CHANCES FOR SUNDAY. RAIN CHANCES MAY NEED TO BE PULLED FURTHER
SOUTHWEST AS WELL DEPENDING ON THE WAVE TRACK. A CLOUDY BREEZY
SHOWERY DAY FOR MOST AREAS IT SEEMS.
MONDAY THROUGH THURSDAY HAVE BELOW NORMAL TEMPERATURES AND MOSTLY
DRY WEATHER UNDER THE INFLUENCE OF THE LONGWAVE TROUGH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 631 PM CDT THU JUL 24 2014
THE AVIATION FORECAST HAS BECOME MORE UNCERTAIN...PRIMARILY WITH
SHOWER AND THUNDERSTORM CHANCES. MUCH OF THIS UNCERTAINTY STEMS
FROM A COMPLEX OF SHOWERS AND EMBEDDED THUNDERSTORMS THAT RECENTLY
DROPPED SOUTH THROUGH WESTERN MN AND IA.
BOTH TAF SITES CURRENTLY SIT IN A PLENTIFUL DRY AIRMASS WHICH
SHOULD KEEP CONDITIONS VFR THROUGH THE EVENING. THERE COULD BE
SOME BRIEF GUSTS AT RST OF 20-25 KT PRIOR TO 01Z AS THE DECAYING
PORTION OF THE COMPLEX MOVES THROUGH. DURING THE OVERNIGHT...
SHOWERS AND THUNDERSTORMS LOOK LIKELY TO FORM AGAIN IN MN AND IA
AND EVENTUALLY PROGRESS EAST-SOUTHEASTWARD THROUGH FRIDAY MORNING.
HOWEVER...WHERE THEY FORM AND IF THEY CAN DEVELOP INTO A COMPLEX
GREATLY AFFECTS THE TAFS. THE LOCATION MAY BE FARTHER WEST THANKS
TO THE CURRENT STORM COMPLEX...WHICH WOULD LEAN TO A BETTER CHANCE
THE TAF SITES STAY DRIER. THEREFORE...HAVE CHANGED THE -TSRA TO
VCTS AND REMOVED ANY LOWER CEILING POTENTIAL AT LSE. STILL
MAINTAINED THE MVFR VISIBILITY AT RST GIVEN THE HIGHER CHANCE FOR
PRECIPITATION TO OCCUR THERE VS LSE. ANY PRECIPITATION SHOULD MOVE
AWAY FROM THE TAF SITES BY 17Z WITH VFR CONDITIONS THEREAFTER.
WINDS COULD GET GUSTY AT RST AGAIN BRIEFLY IN THE LATE MORNING AND
AFTERNOON IN THE WAKE OF THE MORNING STORMS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1118 AM MDT WED JUL 23 2014
.UPDATE...
ISSUED AT 850 AM MDT WED JUL 23 2014
EAST UPSLOPE FLOW IS CURRENTLY HOLDING THE LOW CLOUDS IN PLACE
ACROSS MUCH OF SOUTHEAST WYOMING EAST OF THE LARAMIE RANGE AND
INTO PARTS OF THE NEBRASKA PANHANDLE. LOW CLOUDS SHOULD MIX OUT BY
LATE THIS MORNING. NOT EXPECTING A BIG IMPACT ON HIGH TEMPERATURES
OR CHANCES FOR THUNDERSTORMS TODAY. ISOLATED CONVECTION
TO DEVELOP OVER THE MOUNTAINS BY EARLY THIS AFTERNOON. LOW CLOUDS
AND STABLE MID LEVEL AIR LEFT BEHIND FORM LAST NIGHTS
THUNDERSTORMS WILL INITIALLY INHIBIT EASTWARD MOVEMENT OF
THUNDERSTORMS INTO THE PLAINS. ONE THING OF NOTE IS THE STABLE
LAYER THAT IS IN PLACE MAY BE STRONGER THAN MODELS SUGGEST...WHICH
COULD HAVE A BROADER IMPACT ON DECREASING THUNDERSTORM CHANCES.
AT THIS TIME IS APPEARS THE MAIN CHANCES FOR THUNDERSTORMS IN THE
PLAINS WILL BE LATE THIS AFTERNOON AND EVENING WITH THE GREATEST
THREAT INTO EAST CENTRAL WYOMING AND THE NORTHERN NEBRASKA
PANHANDLE. THIS IS ALSO WHERE THE MAIN THREAT FOR SEVERE
THUNDERSTORMS WILL BE GIVEN A STRONGER SHEAR PROFILE AND HIGHER
CAPE VALUES. MAIN THREAT WILL BE THE LARGE HAIL BUT STRONG WINDS
AND AN AN ISOLATED TORNADO POSSIBLE. WITH ANY LUCK MOST
THUNDERSTORM ACTIVITY IN THE PLAINS WILL HOLD OFF UNTIL LATE THIS
EVENING AS THE LOW LEVEL JET RAMPS UP AND STRONGER MID LEVEL
THETAE ADVECTION KICKS IN. THIS WILL MAKE FOR THE MAIN THUNDERSTORM
CHANCES TOWARD CHADRON AND POINTS NORTH AND EAST OF THE FORECAST
AREA.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 300 AM MDT WED JUL 23 2014
LOTS OF FORECAST CHALLENGES WITH THIS FORECAST PACKAGE...RANGING
FROM SEVERE CONVECTIVE WEATHER TODAY TO FIRE WEATHER CONCERNS
THURSDAY AND FRIDAY.
CURRENTLY...THE MUCH ANTICIPATED COLD FRONT DID MOVE INTO THE AREA
LAST EVENING AND IS CURRENTLY LOCATED GENERALLY ALONG A LINE FROM
CASPER...ALONG THE LARAMIE RANGE DOWN TO LARAMIE AND THEN INTO
NORTHEASTERN COLORADO. THIS FRONT IS SEPARATING VERY MOIST AIR
EAST OF THE FRONT...CHEYENNE HAS A 1AM DEWPOINT OF 57F/LARAMIE
55F...FROM VERY DRY AIR OUT OVER CARBON COUNTY WHERE THE DEWPOINT
AT RAWLINS IS 29F. THIS FEATURE IS GOING TO PLAY A MAJOR ROLE IN
TODAYS FORECAST WEATHER.
FOR TODAY...FRONT IS GOING TO REMAIN AT ITS CURRENT LOCATION
THROUGH THE MORNING HOURS BEFORE IT STARTS TO GET FORCED EAST WITH
INCREASING WESTERLY FLOW. LATEST HRRR FORECAST COMPOSITE
REFLECTIVITY HAS CONVECTION INITIATING ACROSS ALBANY COUNTY AND
THE SOUTH LARAMIE RANGE RIGHT AROUND 20Z TODAY DURING PEAK
HEATING. NAM SOUNDING FOR CHEYENNE HAS CAPE AROUND 1300 J/KG AT
THAT TIME WITH NO CONVECTIVE INHIBITION. PANHANDLE STAYS CAPPED A
LITTLE LONGER...NOT BREAKING THE CAP UNTIL AFTER 00Z. MUCH MORE
UNSTABLE OUT THERE WITH CHADRON NAM SOUNDING SHOWING SBCAPE CLOSE
TO 3500 J/KG. THINK DAY 1 SPC SLIGHT RISK AREA IS PRETTY
GOOD...BUT DO THINK THE LARAMIE COUNTY IS GOING TO SEE SOME SEVERE
THUNDERSTORMS AS WELL AND HAVE TAILORED OUR FORECAST WITH LARAMIE
COUNTY EXPERIENCING SEVERE THUNDERSTORMS THIS AFTERNOON. SEVERE
THUNDERSTORMS INITIALLY OVER THE SOUTHEAST WYOMING PLAINS...THEN
SPREADING EAST INTO THE PANHANDLE AFTER 00Z...AS THE FRONT MOVES
EAST AS A DRY LINE.
FOR THURSDAY...UPPER LOW MOVES INTO MONTANA THURSDAY AFTERNOON
WITH 700MB WINDS INCREASING OVER WYOMING. BY 18Z GFS 700MB WINDS
INCREASE TO 25-30KTS OVER CARBON AND ALBANY COUNTIES. BOTH THE GFS
AND ECMWF SHOW A UPPER LEVEL SHORTWAVE TRACKING THROUGH THE UPPER
RIDGE ALONG THE COLORADO/WYOMING LINE THAT WILL INTERACT WITH SOME
RESIDUAL MONSOONAL MOISTURE TO CREATE AFTERNOON THUNDERSTORMS. GFS
HAS PRECIP MAINLY OVER COLORADO...WHILE ECMWF SPREAD THIS MOISTURE
NORTH INTO WYOMING. DID A BLEND OF THE TWO MODELS WITH CHANCE
SHOWERS AND THUNDERSTORMS OVER SOUTHERN WYOMING NEAR THE COLORADO
BORDER, FORECAST SOUNDING SHOW THE POSSIBILITY OF DRY
THUNDERSTORMS OUT WEST OF THE LARAMIE RANGE THAT HAS ME A LITTLE
WORRIED ABOUT FIRE STARTS AS AFTERNOON MIN HUMIDITIES FALL TO 10
PERCENT ACROSS CARBON...NORTH ALBANY AND WEST CONVERSE COUNTIES.
WENT AHEAD WITH A FIRE WEATHER WATCH FOR THURSDAY FOR CONVERSE
COUNTY AS THIS AREA LOOKS TO BE THE BEST FOR A COMBINATION OF LOW
HUMIDITIES...GUSTY WINDS AND DRY THUNDERSTORMS.
GUSTY WEST WINDS CONTINUE INTO FRIDAY WITH VERY DRY DOWNSLOPING
WINDS OFF THE LARAMIE RANGE. COULD BE LOOKING AT WIDESPREAD FIRE
WEATHER CONDITIONS FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 240 AM MDT WED JUL 23 2014
MODELS GENERALLY IN GOOD AGREEMENT THROUGH THE WEEKEND WITH THE
OVERALL PATTERN...SHOWING A POTENT UPPER LEVEL TROUGH DIGGING
SOUTHWARD OUT OF CANADA AND INTO THE GREAT LAKES REGION BY EARLY
SUNDAY. THIS WILL RESULT IN NORTHWEST FLOW OVER THE FORECAST AREA
AS THE STRONG UPPER LEVEL HIGH NUDGES SOUTHWARD AND THE
ASSOCIATED RIDGE AXIS WILL EXTEND NORTHWEST INTO THE GREAT BASIN
REGION. THERE ARE STILL DISCREPANCIES BETWEEN MODELS REGARDING
AVAILABLE LOW TO MIDLEVEL MOISTURE THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK. ALTHOUGH A SERIES OF COOL FRONTS ARE EXPECTED TO
PUSH SOUTHWARD ACROSS THE FORECAST AREA BEGINNING FRIDAY
NIGHT...THE LACK OF ANY DEFINED DISTURBANCES IS CREATING QUITE A
BIT OF UNCERTAINTY WITH TSTORM CHANCES INTO MONDAY. CURRENT 00Z
MODELS ARE BEGINNING TO TREND DRIER...AS THE NORTHWEST FLOW
RESULTS IN A BIT MORE STABILITY THAN PREVIOUSLY EXPECTED...NUDGING
THE MONSOON MOISTURE FURTHER SOUTH INTO THE FOUR CORNERS REGION
AND COLORADO. STARTED TO LOWER POP FOR THIS WEEKEND ACROSS MOST OF
THE AREA...ESPECIALLY FURTHER NORTH SINCE THE ECMWF IS NOW
TRENDING DRIER AS WELL. CURRENT SOUNDINGS SHOW TOO MUCH DRY AIR
ALOFT...SUPPRESSING ANY CONVECTION THAT DOES FORM. AFTER ANOTHER
WARM DAY ON SATURDAY...EXPECT TEMPERATURES TO LOWER BELOW NORMAL
ON SUNDAY WITH HIGHS IN THE 70S TO MID 80S UNDER COOL EAST TO
NORTHEAST FLOW.
CONDITIONS BECOME A LITTLE MORE INTERESTING AFTER MONDAY AS BOTH
THE GFS AND ECMWF SHOW SHORTWAVE ENERGY MOVING CLOCKWISE AROUND
THE MAIN UPPER LEVEL HIGH AND INTO WYOMING. INCREASED POP LATE MONDAY
THROUGH WEDNESDAY...MAINLY IN THE AFTERNOON AND EVENINGS. BOTH THE
GFS AND ECMWF ARE ON THE AGGRESSIVE SIDE WITH A HIGHER COVERAGE OF
SHOWERS AND TSTORMS...AT LEAST SCATTERED DURING THE AFTERNOON...AS
THE SHORTWAVE ENERGY PUSHES ACROSS EASTERN WYOMING BY WEDNESDAY.
KEPT TEMPERATURES A FEW DEGREES BELOW NORMAL DUE TO EASTERLY
UPSLOPE FLOW AND 700MB TEMPERATURES LOWERING TO BELOW 10C.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
VFR EXPECTED OVERALL FOR ALL AERODROMES THROUGH THURSDAY. ISOLATED
SHOWERS AND TSTRMS OVER THE PLAINS THIS AFTERNOON AND EVENING WITH
ASSOCIATED MVFR VSBYS BUT LOOKING TOO ISOLATED TO MENTION IN
INDIVIDUAL TAFS.
&&
.FIRE WEATHER...
ISSUED AT 300 AM MDT WED JUL 23 2014
DRY CONDITIONS ACROSS WESTERN CARBON COUNTY AGAIN TODAY. A COLD
FRONT GENERALLY ALONG A LINE FROM CASPER TO LARAMIE WILL SEPARATE
RELATIVELY MOIST AIR EAST OF THE FRONT FROM THE REALLY DRY AIR TO
THE WEST. WETTING RAINS ARE LIKELY IN THE EASTERN SECTOR TODAY AND
TONIGHT WITH EXCELLENT OVERNIGHT RH RECOVERIES. CONDITIONS CHANGE
FOR THURSDAY THOUGH AS THE FRONT BEGINS TO MOVE EAST AGAIN AND
WINDS BEGIN TO PICK UP WEST OF THE LARAMIE RANGE. CRITICAL FIRE
WEATHER CONDITIONS FROM GUSTY WINDS AND LOW HUMIDITIES EARLY
THURSDAY AFTERNOON. TO COMPLICATE THE CONDITIONS MORE...WE HAVE
THE POSSIBILITY OF DRY THUNDERSTORMS WEST OF THE LARAMIE RANGE
THAT COULD CREATE SOME FIRE STARTS THURSDAY AFTERNOON. A FIRE
WEATHER WATCH HAS BEEN ISSUED FOR FWZ 301 FOR THURSDAY LATE
MORNING THROUGH THE AFTERNOON. DRY AND WINDY CONDITIONS TO
CONTINUE INTO SATURDAY FOR MORE WIDESPREAD FIRE WEATHER CONDITIONS
ACROSS SOUTHEAST WYOMING.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR WYZ301.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...CLAYCOMB
LONG TERM...TJT
AVIATION...RE
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
912 AM MDT WED JUL 23 2014
.UPDATE...
ISSUED AT 850 AM MDT WED JUL 23 2014
EAST UPSLOPE FLOW IS CURRENTLY HOLDING THE LOW CLOUDS IN PLACE
ACROSS MUCH OF SOUTHEAST WYOMING EAST OF THE LARAMIE RANGE AND
INTO PARTS OF THE NEBRASKA PANHANDLE. LOW CLOUDS SHOULD MIX OUT BY
LATE THIS MORNING. NOT EXPECTING A BIG IMPACT ON HIGH TEMPERATURES
OR CHANCES FOR THUNDERSTORMS TODAY. ISOLATED CONVECTION
TO DEVELOP OVER THE MOUNTAINS BY EARLY THIS AFTERNOON. LOW CLOUDS
AND STABLE MID LEVEL AIR LEFT BEHIND FORM LAST NIGHTS
THUNDERSTORMS WILL INITIALLY INHIBIT EASTWARD MOVEMENT OF
THUNDERSTORMS INTO THE PLAINS. ONE THING OF NOTE IS THE STABLE
LAYER THAT IS IN PLACE MAY BE STRONGER THAN MODELS SUGGEST...WHICH
COULD HAVE A BROADER IMPACT ON DECREASING THUNDERSTORM CHANCES.
AT THIS TIME IS APPEARS THE MAIN CHANCES FOR THUNDERSTORMS IN THE
PLAINS WILL BE LATE THIS AFTERNOON AND EVENING WITH THE GREATEST
THREAT INTO EAST CENTRAL WYOMING AND THE NORTHERN NEBRASKA
PANHANDLE. THIS IS ALSO WHERE THE MAIN THREAT FOR SEVERE
THUNDERSTORMS WILL BE GIVEN A STRONGER SHEAR PROFILE AND HIGHER
CAPE VALUES. MAIN THREAT WILL BE THE LARGE HAIL BUT STRONG WINDS
AND AN AN ISOLATED TORNADO POSSIBLE. WITH ANY LUCK MOST
THUNDERSTORM ACTIVITY IN THE PLAINS WILL HOLD OFF UNTIL LATE THIS
EVENING AS THE LOW LEVEL JET RAMPS UP AND STRONGER MID LEVEL
THETAE ADVECTION KICKS IN. THIS WILL MAKE FOR THE MAIN THUNDERSTORM
CHANCES TOWARD CHADRON AND POINTS NORTH AND EAST OF THE FORECAST AREA.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 300 AM MDT WED JUL 23 2014
LOTS OF FORECAST CHALLENGES WITH THIS FORECAST PACKAGE...RANGING
FROM SEVERE CONVECTIVE WEATHER TODAY TO FIRE WEATHER CONCERNS
THURSDAY AND FRIDAY.
CURRENTLY...THE MUCH ANTICIPATED COLD FRONT DID MOVE INTO THE AREA
LAST EVENING AND IS CURRENTLY LOCATED GENERALLY ALONG A LINE FROM
CASPER...ALONG THE LARAMIE RANGE DOWN TO LARAMIE AND THEN INTO
NORTHEASTERN COLORADO. THIS FRONT IS SEPARATING VERY MOIST AIR
EAST OF THE FRONT...CHEYENNE HAS A 1AM DEWPOINT OF 57F/LARAMIE
55F...FROM VERY DRY AIR OUT OVER CARBON COUNTY WHERE THE DEWPOINT
AT RAWLINS IS 29F. THIS FEATURE IS GOING TO PLAY A MAJOR ROLE IN
TODAYS FORECAST WEATHER.
FOR TODAY...FRONT IS GOING TO REMAIN AT ITS CURRENT LOCATION
THROUGH THE MORNING HOURS BEFORE IT STARTS TO GET FORCED EAST WITH
INCREASING WESTERLY FLOW. LATEST HRRR FORECAST COMPOSITE
REFLECTIVITY HAS CONVECTION INITIATING ACROSS ALBANY COUNTY AND
THE SOUTH LARAMIE RANGE RIGHT AROUND 20Z TODAY DURING PEAK
HEATING. NAM SOUNDING FOR CHEYENNE HAS CAPE AROUND 1300 J/KG AT
THAT TIME WITH NO CONVECTIVE INHIBITION. PANHANDLE STAYS CAPPED A
LITTLE LONGER...NOT BREAKING THE CAP UNTIL AFTER 00Z. MUCH MORE
UNSTABLE OUT THERE WITH CHADRON NAM SOUNDING SHOWING SBCAPE CLOSE
TO 3500 J/KG. THINK DAY 1 SPC SLIGHT RISK AREA IS PRETTY
GOOD...BUT DO THINK THE LARAMIE COUNTY IS GOING TO SEE SOME SEVERE
THUNDERSTORMS AS WELL AND HAVE TAILORED OUR FORECAST WITH LARAMIE
COUNTY EXPERIENCING SEVERE THUNDERSTORMS THIS AFTERNOON. SEVERE
THUNDERSTORMS INITIALLY OVER THE SOUTHEAST WYOMING PLAINS...THEN
SPREADING EAST INTO THE PANHANDLE AFTER 00Z...AS THE FRONT MOVES
EAST AS A DRY LINE.
FOR THURSDAY...UPPER LOW MOVES INTO MONTANA THURSDAY AFTERNOON
WITH 700MB WINDS INCREASING OVER WYOMING. BY 18Z GFS 700MB WINDS
INCREASE TO 25-30KTS OVER CARBON AND ALBANY COUNTIES. BOTH THE GFS
AND ECMWF SHOW A UPPER LEVEL SHORTWAVE TRACKING THROUGH THE UPPER
RIDGE ALONG THE COLORADO/WYOMING LINE THAT WILL INTERACT WITH SOME
RESIDUAL MONSOONAL MOISTURE TO CREATE AFTERNOON THUNDERSTORMS. GFS
HAS PRECIP MAINLY OVER COLORADO...WHILE ECMWF SPREAD THIS MOISTURE
NORTH INTO WYOMING. DID A BLEND OF THE TWO MODELS WITH CHANCE
SHOWERS AND THUNDERSTORMS OVER SOUTHERN WYOMING NEAR THE COLORADO
BORDER, FORECAST SOUNDING SHOW THE POSSIBILITY OF DRY
THUNDERSTORMS OUT WEST OF THE LARAMIE RANGE THAT HAS ME A LITTLE
WORRIED ABOUT FIRE STARTS AS AFTERNOON MIN HUMIDITIES FALL TO 10
PERCENT ACROSS CARBON...NORTH ALBANY AND WEST CONVERSE COUNTIES.
WENT AHEAD WITH A FIRE WEATHER WATCH FOR THURSDAY FOR CONVERSE
COUNTY AS THIS AREA LOOKS TO BE THE BEST FOR A COMBINATION OF LOW
HUMIDITIES...GUSTY WINDS AND DRY THUNDERSTORMS.
GUSTY WEST WINDS CONTINUE INTO FRIDAY WITH VERY DRY DOWNSLOPING
WINDS OFF THE LARAMIE RANGE. COULD BE LOOKING AT WIDESPREAD FIRE
WEATHER CONDITIONS FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 240 AM MDT WED JUL 23 2014
MODELS GENERALLY IN GOOD AGREEMENT THROUGH THE WEEKEND WITH THE
OVERALL PATTERN...SHOWING A POTENT UPPER LEVEL TROUGH DIGGING
SOUTHWARD OUT OF CANADA AND INTO THE GREAT LAKES REGION BY EARLY
SUNDAY. THIS WILL RESULT IN NORTHWEST FLOW OVER THE FORECAST AREA
AS THE STRONG UPPER LEVEL HIGH NUDGES SOUTHWARD AND THE
ASSOCIATED RIDGE AXIS WILL EXTEND NORTHWEST INTO THE GREAT BASIN
REGION. THERE ARE STILL DISCREPANCIES BETWEEN MODELS REGARDING
AVAILABLE LOW TO MIDLEVEL MOISTURE THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK. ALTHOUGH A SERIES OF COOL FRONTS ARE EXPECTED TO
PUSH SOUTHWARD ACROSS THE FORECAST AREA BEGINNING FRIDAY
NIGHT...THE LACK OF ANY DEFINED DISTURBANCES IS CREATING QUITE A
BIT OF UNCERTAINTY WITH TSTORM CHANCES INTO MONDAY. CURRENT 00Z
MODELS ARE BEGINNING TO TREND DRIER...AS THE NORTHWEST FLOW
RESULTS IN A BIT MORE STABILITY THAN PREVIOUSLY EXPECTED...NUDGING
THE MONSOON MOISTURE FURTHER SOUTH INTO THE FOUR CORNERS REGION
AND COLORADO. STARTED TO LOWER POP FOR THIS WEEKEND ACROSS MOST OF
THE AREA...ESPECIALLY FURTHER NORTH SINCE THE ECMWF IS NOW
TRENDING DRIER AS WELL. CURRENT SOUNDINGS SHOW TOO MUCH DRY AIR
ALOFT...SUPPRESSING ANY CONVECTION THAT DOES FORM. AFTER ANOTHER
WARM DAY ON SATURDAY...EXPECT TEMPERATURES TO LOWER BELOW NORMAL
ON SUNDAY WITH HIGHS IN THE 70S TO MID 80S UNDER COOL EAST TO
NORTHEAST FLOW.
CONDITIONS BECOME A LITTLE MORE INTERESTING AFTER MONDAY AS BOTH
THE GFS AND ECMWF SHOW SHORTWAVE ENERGY MOVING CLOCKWISE AROUND
THE MAIN UPPER LEVEL HIGH AND INTO WYOMING. INCREASED POP LATE MONDAY
THROUGH WEDNESDAY...MAINLY IN THE AFTERNOON AND EVENINGS. BOTH THE
GFS AND ECMWF ARE ON THE AGGRESSIVE SIDE WITH A HIGHER COVERAGE OF
SHOWERS AND TSTORMS...AT LEAST SCATTERED DURING THE AFTERNOON...AS
THE SHORTWAVE ENERGY PUSHES ACROSS EASTERN WYOMING BY WEDNESDAY.
KEPT TEMPERATURES A FEW DEGREES BELOW NORMAL DUE TO EASTERLY
UPSLOPE FLOW AND 700MB TEMPERATURES LOWERING TO BELOW 10C.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH WEDNESDAY NIGHT)
VFR CONDITIONS WILL PREVAIL THROUGH WEDNESDAY NIGHT...ALTHOUGH
BRIEF MVFR VIS ARE POSSIBLE IN AND AROUND THUNDERSTORM ACTIVITY
THIS AFTERNOON AND THIS EVENING. ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS WILL AFFECT THE HIGH PLAINS IN ADDITION TO KLAR
BEGINNING EARLY THIS AFTERNOON. THERE IS A SLIGHT CHANCE OF LOW
CIGS EARLY THIS MORNING ACROSS PARTS OF THE HIGH PLAINS...BUT
THERE IS STILL TOO MUCH UNCERTAINTY AT THIS TIME TO ADD TO AREA
TAFS.
&&
.FIRE WEATHER...
ISSUED AT 300 AM MDT WED JUL 23 2014
DRY CONDITIONS ACROSS WESTERN CARBON COUNTY AGAIN TODAY. A COLD
FRONT GENERALLY ALONG A LINE FROM CASPER TO LARAMIE WILL SEPARATE
RELATIVELY MOIST AIR EAST OF THE FRONT FROM THE REALLY DRY AIR TO
THE WEST. WETTING RAINS ARE LIKELY IN THE EASTERN SECTOR TODAY AND
TONIGHT WITH EXCELLENT OVERNIGHT RH RECOVERIES. CONDITIONS CHANGE
FOR THURSDAY THOUGH AS THE FRONT BEGINS TO MOVE EAST AGAIN AND
WINDS BEGIN TO PICK UP WEST OF THE LARAMIE RANGE. CRITICAL FIRE
WEATHER CONDITIONS FROM GUSTY WINDS AND LOW HUMIDITIES EARLY
THURSDAY AFTERNOON. TO COMPLICATE THE CONDITIONS MORE...WE HAVE
THE POSSIBILITY OF DRY THUNDERSTORMS WEST OF THE LARAMIE RANGE
THAT COULD CREATE SOME FIRE STARTS THURSDAY AFTERNOON. A FIRE
WEATHER WATCH HAS BEEN ISSUED FOR FWZ 301 FOR THURSDAY LATE
MORNING THROUGH THE AFTERNOON. DRY AND WINDY CONDITIONS TO
CONTINUE INTO SATURDAY FOR MORE WIDESPREAD FIRE WEATHER CONDITIONS
ACROSS SOUTHEAST WYOMING.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR WYZ301.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...CLAYCOMB
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
253 AM MDT WED JUL 23 2014
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 300 AM MDT WED JUL 23 2014
LOTS OF FORECAST CHALLENGES WITH THIS FORECAST PACKAGE...RANGING
FROM SEVERE CONVECTIVE WEATHER TODAY TO FIRE WEATHER CONCERNS
THURSDAY AND FRIDAY.
CURRENTLY...THE MUCH ANTICIPATED COLD FRONT DID MOVE INTO THE AREA
LAST EVENING AND IS CURRENTLY LOCATED GENERALLY ALONG A LINE FROM
CASPER...ALONG THE LARAMIE RANGE DOWN TO LARAMIE AND THEN INTO
NORTHEASTERN COLORADO. THIS FRONT IS SEPARATING VERY MOIST AIR
EAST OF THE FRONT...CHEYENNE HAS A 1AM DEWPOINT OF 57F/LARAMIE
55F...FROM VERY DRY AIR OUT OVER CARBON COUNTY WHERE THE DEWPOINT
AT RAWLINS IS 29F. THIS FEATURE IS GOING TO PLAY A MAJOR ROLE IN
TODAYS FORECAST WEATHER.
FOR TODAY...FRONT IS GOING TO REMAIN AT ITS CURRENT LOCATION
THROUGH THE MORNING HOURS BEFORE IT STARTS TO GET FORCED EAST WITH
INCREASING WESTERLY FLOW. LATEST HRRR FORECAST COMPOSITE
REFLECTIVITY HAS CONVECTION INITIATING ACROSS ALBANY COUNTY AND
THE SOUTH LARAMIE RANGE RIGHT AROUND 20Z TODAY DURING PEAK
HEATING. NAM SOUNDING FOR CHEYENNE HAS CAPE AROUND 1300 J/KG AT
THAT TIME WITH NO CONVECTIVE INHIBITION. PANHANDLE STAYS CAPPED A
LITTLE LONGER...NOT BREAKING THE CAP UNTIL AFTER 00Z. MUCH MORE
UNSTABLE OUT THERE WITH CHADRON NAM SOUNDING SHOWING SBCAPE CLOSE
TO 3500 J/KG. THINK DAY 1 SPC SLIGHT RISK AREA IS PRETTY
GOOD...BUT DO THINK THE LARAMIE COUNTY IS GOING TO SEE SOME SEVERE
THUNDERSTORMS AS WELL AND HAVE TAILORED OUR FORECAST WITH LARAMIE
COUNTY EXPERIENCING SEVERE THUNDERSTORMS THIS AFTERNOON. SEVERE
THUNDERSTORMS INITIALLY OVER THE SOUTHEAST WYOMING PLAINS...THEN
SPREADING EAST INTO THE PANHANDLE AFTER 00Z...AS THE FRONT MOVES
EAST AS A DRY LINE.
FOR THURSDAY...UPPER LOW MOVES INTO MONTANA THURSDAY AFTERNOON
WITH 700MB WINDS INCREASING OVER WYOMING. BY 18Z GFS 700MB WINDS
INCREASE TO 25-30KTS OVER CARBON AND ALBANY COUNTIES. BOTH THE GFS
AND ECMWF SHOW A UPPER LEVEL SHORTWAVE TRACKING THROUGH THE UPPER
RIDGE ALONG THE COLORADO/WYOMING LINE THAT WILL INTERACT WITH SOME
RESIDUAL MONSOONAL MOISTURE TO CREATE AFTERNOON THUNDERSTORMS. GFS
HAS PRECIP MAINLY OVER COLORADO...WHILE ECMWF SPREAD THIS MOISTURE
NORTH INTO WYOMING. DID A BLEND OF THE TWO MODELS WITH CHANCE
SHOWERS AND THUNDERSTORMS OVER SOUTHERN WYOMING NEAR THE COLORADO
BORDER, FORECAST SOUNDING SHOW THE POSSIBILITY OF DRY
THUNDERSTORMS OUT WEST OF THE LARAMIE RANGE THAT HAS ME A LITTLE
WORRIED ABOUT FIRE STARTS AS AFTERNOON MIN HUMIDITIES FALL TO 10
PERCENT ACROSS CARBON...NORTH ALBANY AND WEST CONVERSE COUNTIES.
WENT AHEAD WITH A FIRE WEATHER WATCH FOR THURSDAY FOR CONVERSE
COUNTY AS THIS AREA LOOKS TO BE THE BEST FOR A COMBINATION OF LOW
HUMIDITIES...GUSTY WINDS AND DRY THUNDERSTORMS.
GUSTY WEST WINDS CONTINUE INTO FRIDAY WITH VERY DRY DOWNSLOPING
WINDS OFF THE LARAMIE RANGE. COULD BE LOOKING AT WIDESPREAD FIRE
WEATHER CONDITIONS FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 240 AM MDT WED JUL 23 2014
MODELS GENERALLY IN GOOD AGREEMENT THROUGH THE WEEKEND WITH THE
OVERALL PATTERN...SHOWING A POTENT UPPER LEVEL TROUGH DIGGING
SOUTHWARD OUT OF CANADA AND INTO THE GREAT LAKES REGION BY EARLY
SUNDAY. THIS WILL RESULT IN NORTHWEST FLOW OVER THE FORECAST AREA
AS THE STRONG UPPER LEVEL HIGH NUDGES SOUTHWARD AND THE
ASSOCIATED RIDGE AXIS WILL EXTEND NORTHWEST INTO THE GREAT BASIN
REGION. THERE ARE STILL DISCREPANCIES BETWEEN MODELS REGARDING
AVAILABLE LOW TO MIDLEVEL MOISTURE THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK. ALTHOUGH A SERIES OF COOL FRONTS ARE EXPECTED TO
PUSH SOUTHWARD ACROSS THE FORECAST AREA BEGINNING FRIDAY
NIGHT...THE LACK OF ANY DEFINED DISTURBANCES IS CREATING QUITE A
BIT OF UNCERTAINTY WITH TSTORM CHANCES INTO MONDAY. CURRENT 00Z
MODELS ARE BEGINNING TO TREND DRIER...AS THE NORTHWEST FLOW
RESULTS IN A BIT MORE STABILITY THAN PREVIOUSLY EXPECTED...NUDGING
THE MONSOON MOISTURE FURTHER SOUTH INTO THE FOUR CORNERS REGION
AND COLORADO. STARTED TO LOWER POP FOR THIS WEEKEND ACROSS MOST OF
THE AREA...ESPECIALLY FURTHER NORTH SINCE THE ECMWF IS NOW
TRENDING DRIER AS WELL. CURRENT SOUNDINGS SHOW TOO MUCH DRY AIR
ALOFT...SUPPRESSING ANY CONVECTION THAT DOES FORM. AFTER ANOTHER
WARM DAY ON SATURDAY...EXPECT TEMPERATURES TO LOWER BELOW NORMAL
ON SUNDAY WITH HIGHS IN THE 70S TO MID 80S UNDER COOL EAST TO
NORTHEAST FLOW.
CONDITIONS BECOME A LITTLE MORE INTERESTING AFTER MONDAY AS BOTH
THE GFS AND ECMWF SHOW SHORTWAVE ENERGY MOVING CLOCKWISE AROUND
THE MAIN UPPER LEVEL HIGH AND INTO WYOMING. INCREASED POP LATE MONDAY
THROUGH WEDNESDAY...MAINLY IN THE AFTERNOON AND EVENINGS. BOTH THE
GFS AND ECMWF ARE ON THE AGGRESSIVE SIDE WITH A HIGHER COVERAGE OF
SHOWERS AND TSTORMS...AT LEAST SCATTERED DURING THE AFTERNOON...AS
THE SHORTWAVE ENERGY PUSHES ACROSS EASTERN WYOMING BY WEDNESDAY.
KEPT TEMPERATURES A FEW DEGREES BELOW NORMAL DUE TO EASTERLY
UPSLOPE FLOW AND 700MB TEMPERATURES LOWERING TO BELOW 10C.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH WEDNESDAY NIGHT)
VFR CONDITIONS WILL PREVAIL THROUGH WEDNESDAY NIGHT...ALTHOUGH
BRIEF MVFR VIS ARE POSSIBLE IN AND AROUND THUNDERSTORM ACTIVITY
THIS AFTERNOON AND THIS EVENING. ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS WILL AFFECT THE HIGH PLAINS IN ADDITION TO KLAR
BEGINNING EARLY THIS AFTERNOON. THERE IS A SLIGHT CHANCE OF LOW
CIGS EARLY THIS MORNING ACROSS PARTS OF THE HIGH PLAINS...BUT
THERE IS STILL TOO MUCH UNCERTAINTY AT THIS TIME TO ADD TO AREA
TAFS.
&&
.FIRE WEATHER...
ISSUED AT 300 AM MDT WED JUL 23 2014
DRY CONDITIONS ACROSS WESTERN CARBON COUNTY AGAIN TODAY. A COLD
FRONT GENERALLY ALONG A LINE FROM CASPER TO LARAMIE WILL SEPARATE
RELATIVELY MOIST AIR EAST OF THE FRONT FROM THE REALLY DRY AIR TO
THE WEST. WETTING RAINS ARE LIKELY IN THE EASTERN SECTOR TODAY AND
TONIGHT WITH EXCELLENT OVERNIGHT RH RECOVERIES. CONDITIONS CHANGE
FOR THURSDAY THOUGH AS THE FRONT BEGINS TO MOVE EAST AGAIN AND
WINDS BEGIN TO PICK UP WEST OF THE LARAMIE RANGE. CRITICAL FIRE
WEATHER CONDITIONS FROM GUSTY WINDS AND LOW HUMIDITIES EARLY
THURSDAY AFTERNOON. TO COMPLICATE THE CONDITIONS MORE...WE HAVE
THE POSSIBILITY OF DRY THUNDERSTORMS WEST OF THE LARAMIE RANGE
THAT COULD CREATE SOME FIRE STARTS THURSDAY AFTERNOON. A FIRE
WEATHER WATCH HAS BEEN ISSUED FOR FWZ 301 FOR THURSDAY LATE
MORNING THROUGH THE AFTERNOON. DRY AND WINDY CONDITIONS TO
CONTINUE INTO SATURDAY FOR MORE WIDESPREAD FIRE WEATHER CONDITIONS
ACROSS SOUTHEAST WYOMING.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR WYZ301.
NE...NONE.
&&
$$
SHORT TERM...CLAYCOMB
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1135 PM MDT TUE JUL 22 2014
.UPDATE...
ISSUED AT 835 PM MDT TUE JUL 22 2014
REGIONAL RADARS SHOWED ISOLATED STRONG CONVECTION THAT PRODUCED
LARGE HAIL NORTHWEST OF CHEYENNE EARLIER THIS EVENING HAS DISSIPATED
AS IT MOVED INTO THE SOUTHERN NEBRASKA PANHANDLE. A CLUSTER OF
STRONG TO SEVERE TSTORMS WAS MOVING SOUTHEAST ALONG A INSTABILITY
AXIS /SBCAPES 2000-3000 J/KG/ TOWARD THE NORTHERN NEBRASKA PANHANDLE.
THESE STORMS SHOULD EXIT OUR NORTHERN PANHANDLE ZONES BY MIDNIGHT.
ANOTHER ACTIVE TSTORM CLUSTER OVER SOUTHEAST MT SHOULD PASS NORTH OF
OUR NORTHERN CWA TONIGHT. UPDATED ZONES TO INCREASE POPS OVER THE
NORTHERN PANHANDLE AND REMOVE THEM OVER SOUTHEAST WY AND SOUTHERN
NEBRASKA PANHANDLE.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 306 PM MDT TUE JUL 22 2014
FAR LESS COVERAGE OF CU COMPARED TO THE SAME TIME MONDAY WHICH
SURELY IS INDICATIVE OF THE WARMER TEMPS ALOFT. SFC MOISTURE HAS
INCREASED BEHIND LAST NIGHTS WEAK BOUNDARY...WITH THE 50F
ISODROSOTHERM BANKED UP TO THE FRONT RANGE. AM BEGINNING TO SEE SOME
WEAK CONVECTIVE DEVELOPMENT MAINLY IN THE VICINITY OF THE NRN
LARAMIE RANGE...AND SOME NR THE SNOWY AND SOUTHERN LARAMIE RANGE
TOO. MESOANALYSIS SHOWS A PRETTY HEALTHY CAPPING INVERSION REMAINS
IN PLACE...ESPECIALLY OVR THE ERN PLAINS. EXPECT THIS CAP CONTINUE
TO ERODE THRU THE AFTERNOON. THE STRONGER CAP WILL MEAN DEEP
CONVECTION WILL BE A BIT LATER IN DEVELOPING...WHICH ACCORDING TO
THE HRRR WILL BE BETWEEN 3-6 PM. LARAMIE COUNTY AND THE SOUTHERN END
OF GOSHEN/PLATTE COUNTIES LOOK TO SEE THE BEST CHANCE INITIALLY.
WILL SEE ADDITIONAL DEVELOPMENT OVR NORTHEAST WYOMING DIVE SOUTHEAST INTO
FAR EAST CENTRAL WYOMING AND THE NRN NEBRASKA PANHANDLE THIS
EVENING. IT IS THIS AREA WHERE SEVERE POTENTIAL WILL BE GREATEST
WITH SBCAPES OF AROUND 2000 J/KG ONCE THE CAP BREAKS. THIS
CONVECTION WILL DISSIPATE BY AROUND SUNSET.
ATTENTION THEN TURNS TO A BETTER CHANCE FOR SEVERE THUNDERSTORM
DEVELOPMENT WEDNESDAY AFTERNOON. THERMODYNAMIC PROFILES WILL BE MORE
CONDUCIVE FOR THUNDERSTORM DEVELOPMENT WEDNESDAY AS MID-LEVEL
HEIGHTS/TEMPS FALL WITH THE APPROACH OF SHORTWAVE ENERGY. THIS WILL
MEAN LESS OF A CAP AND A LIKELY EARLIER START TO CONVECTIVE
INITIATION...WHICH SHOULD OCCUR OVR THE SNOWY/SIERRA MADRE RANGES BY
MIDDAY. PROGGED SBCAPES OVR THE ERN PLAINS CLIMB ABOVE 3000 J/KG
WEDNESDAY AFTERNOON AND WHEN COMBINED WITH DEEP LAYER SHEAR OF 25-30
KNOTS SHOULD BE SUFFICIENT FOR SOME CONVECTIVE ACTIVITY BECOMING
SEVERE. STORMS WILL SPREAD ONTO THE SOUTHEAST WYOMING PLAINS
WEDNESDAY AFTERNOON AND INTO THE WESTERN NEBRASKA PANHANDLE DURING
THE EVENING. AREAS OVR THE SOUTHERN PANHANDLE MAY BE INFLUENCED A
BIT TOO MUCH BY THE CAP...WHICH MAY LIMIT CONVECTIVE STRENGTH THERE.
CONVECTION AGAIN WILL WANE WITH LOSS OF INSOLATION.
FIRST SHORTWAVE PUSHES THRU THURSDAY MORNING WITH A TRAILING
SHORTWAVE POISED TO MOVE THRU THURSDAY AFTERNOON. INSTABILITY AXIS
WILL BE FLATTENED AND WEAKENED BY THE INITIAL SHORTWAVE. SO EXPECT A
LESS FAVORABLE ENVIRONMENT FOR SEVERE THUNDERSTORM POTENTIAL. EVEN
SO...WEAK INSTABILITY PARAMETERS WILL BE SUFFICIENT FOR AT LEAST
SOME ISOLATED CONVECTIVE POTENTIAL. THURSDAY WILL BE THE WARMEST DAY
OF THE PERIOD WITH HIGH TEMPERATURES THAT WILL AGAIN REACH 90S AT
MOST LOCATION AND LOW TRIPLE DIGITS OVER LOWER ELEVATIONS OF THE
WESTERN NEBRASKA PANHANDLE.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 306 PM MDT TUE JUL 22 2014
HIGH PRESSURE CONTINUES TO REMAIN DOMINANT OVER THE FOUR CORNERS
REGION BUT BEGINS TO ERODE TO THE SOUTH OVER THE WEEKEND. FAIRLY POTENT
TROUGH OF LOW PRESSURE MOVES ACROSS THE SOUTHERN CANADIAN PROVINCES
AND BRINGS A SERIES OF ASSOCIATED COOL FRONTS ACROSS THE AREA (THE
STRONGEST FRONT WILL BE SAT EVENING). UPSLOPE FLOW LOOKS TO DEVELOP
BY FRI AFTN AS DEW POINTS APPROACH THE MID 50S OVER THE PANHANDLE.
COULD SEE SOME ISOLATED SHOWERS AND THUNDERSTORMS DURING THIS
TIME FRAME BOTH FRI AND SAT SO HAVE KEPT SOME SLIGHT POPS IN THE
FCST. THE ECMWF IS MORE MOIST THAN THE GFS ATTM AND GENERATES A
BETTER COVERAGE OF STORMS EACH AFTN AND EVENING. TEMPS BEGIN TO COOL
TO MORE SEASONABLE LEVELS IN THE LOW TO MID 80S FOR SUNDAY...BUT THE
RIDGE BEGINS TO BUILD BACK INTO THE AREA AND TEMPS SHOULD WARM TO
THE MID 80S BY MONDAY FOR SOUTHEASTERN WY AND NEAR 90 FOR AREAS OF
THE PANHANDLE AS 700 MB TEMPS WARM TO NEAR 15C.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH WEDNESDAY EVENING)
ISSUED AT 1131 PM MDT TUE JUL 22 2014
VFR CONDITIONS WILL PREVAIL THROUGH WEDNESDAY. INCREASING MOISTURE
IN THE MID LEVELS ON WEDNESDAY AFTERNOON MAY RESULT IN ANOTHER ROUND
OF SHOWERS AND THUNDERSTORMS AFFECTING THE HIGH PLAINS AND KLAR.
MVFR VIS ARE POSSIBLE IN THE AREAS OF HEAVIER RAINFALL. THERE IS A
SLIGHT CHANCE OF LOW CIGS EARLY WEDNESDAY MORNING ACROSS PARTS OF
THE HIGH PLAINS...BUT THERE IS TOO MUCH UNCERTAINTY WITH THE
LOCATION TO ADD LOW CIGS TO ANY TERMINAL AT THIS TIME.
&&
.FIRE WEATHER...
ISSUED AT 306 PM MDT TUE JUL 22 2014
WINDS HAVE HELD BELOW CRITICAL THRESHOLDS THUS FAR TODAY...DESPITE
RELATIVE HUMIDITIES THAT HAVE DROPPED BELOW 15 PERCENT. SOME
ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER
LARAMIE COUNTY LATE THIS AFTERNOON AND OVER EXTREME EAST CENTRAL
WYOMING AND THE NORTHERN NEBRASKA PANHANDLE THIS EVENING. WEDNESDAY
WILL PROVIDE A BETTER OPPORTUNITY FOR AFTERNOON AND EVENING
THUNDERSTORMS ACROSS THE DISTRICT...SOME OF WHICH COULD POTENTIALLY
BECOME SEVERE IN LOCATIONS EAST OF THE LARAMIE RANGE. DRIER AND
BREEZIER CONDITIONS WILL EXIST OVER WESTERN CARBON AND CONVERSE
COUNTIES ON WEDNESDAY. CONDITIONS WILL LIKELY BECOME NEAR CRITICAL
IN THESE AREAS WEDNESDAY. THURSDAY LOOKS POTENTIALLY MORE CRITICAL
OVER WESTERN CARBON AND CONVERSE COUNTIES AND WILL LIKELY NEED TO
ISSUE A HEADLINE IN TIME. AFTERNOON AND EVENING SHOWER AND
THUNDERSTORM CHANCES WILL CONTINUE THURSDAY AND FRIDAY MAINLY FOR
AREAS EAST OF THE LARAMIE RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...JAMSKI
SHORT TERM...HAHN
LONG TERM...FINCH
AVIATION...HAMMER
FIRE WEATHER...HAHN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
328 AM MDT FRI JUL 25 2014
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 330 AM MDT FRI JUL 25 2014
THE UPPER HIGH HAS SHIFTED SOUTH OF COLORADO DURING THE PAST 12
HOURS AND IS NOW CENTERED OVER NEW MEXICO AND WESTERN TEXAS. THIS
HAS RESULTED IN A MORE WESTERLY FLOW ALOFT OVER COLORADO WITH MAIN
MOISTURE PLUME ACROSS NORTHERN AND CENTRAL PORTIONS OF THE STATE.
INTEGRATED PRECIPITABLE WATER VALUES ARE JUST UNDER AN INCH OVER
FRONT RANGE. EXPECT THIS PLUME OF MOISTURE TO HOLD OVER THE REGION
FOR THIS AFTERNOON AND TONIGHT WITH PW VALUES REMAINING CLOSE TO
AN INCH. THERE ARE STILL ISOLATED SHOWERS AND THUNDERSTORMS
CONTINUING OVER MOUNTAINS AND WEST AND HAVE ADDED LOW POPS FOR THE
PRE DAWN HOURS.
A WEAK COLD FRONT WILL MOVE SOUTH FROM WYOMING DURING THE EARLY
MORNING HOURS OVER NORTHEAST COLORADO WITH NORTHEAST TO EAST WINDS
DEVELOPING BEHIND THE FRONT. THERE WILL BE SOME COOLING AND LOW
LEVEL STABILITY THIS AFTERNOON BUT LOW LEVEL CAP LOOKS TO ERODE BY
LATE AFTERNOON WHILE SURFACE DEWPOINTS REMAIN IN THE UPPER 40S AND
LOWER 50S. SHOULD BE ENOUGH INSTABILITY AND AMPLE MOISTURE FOR A
ROUND OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. LATEST HRRR
SHOWING A BROAD AREA OF SHOWERS MOVING OFF THE FOOTHILLS BETWEEN
20-22Z. THE RAP/NAM SEEM TO HOLD MORE OF THE SHOWERS ANCHORED ON
HIGHER TERRAIN WITH MORE ISOLATED ACTIVITY ON THE PLAINS. GIVEN
THE AMOUNT OF MOISTURE WOULD FAVOR THE HRRR SOLUTION AND WILL BUMP
POPS UP SLIGHTLY TO CHANCE CATEGORIES BY LATE AFTERNOON OVER THE
FRONT RANGE AND ADJACENT PLAINS. LIKE YESTERDAY...MAIN THREATS
WILL BE BRIEF HEAVY RAIN AND GUSTY WINDS TO AROUND 50 MPH WITH THE
STRONGER STORMS.
TEMPERATURES WILL BE COOLER TODAY FOLLOWING THE
FRONTAL PASSAGE WITH READINGS AROUND 90 DEGREES OVER LOWER
ELEVATIONS. MOST OF THE STORMS WILL DIMINISH BY LATER THIS EVENING
WITH LACK OF ANY SIGNIFICANT FORCING ALOFT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 AM MDT FRI JUL 25 2014
ANOTHER WEAK BACKDOOR COLD FRONT IS EXPECTED TO PUSH ACROSS THE
PLAINS ON SATURDAY...RESULTING IN SLIGHT COOLING AND
STABILIZATION. THE AIRMASS WILL LIKELY REMAIN CAPPED OVER THE
NORTHEAST CORNER OF THE STATE...WHILE THE MOUNTAINS WILL STILL SEE
SCATTERED SHOWERS AND STORMS IN THE AFTERNOON AND EVENING AS
MID/UPPER LEVEL MOISTURE PLUME REMAINS ACROSS THE FORECAST AREA.
IN BETWEEN...THE ENVIRONMENT WILL BE MARGINAL FOR STORMS...BUT
WITH WESTERLY FLOW ALOFT WE SHOULD SEE ISOLATED SHOWERS/STORMS DRIFT
OFF THE FRONT RANGE AND HELP POP A FEW CELLS THROUGH THE CAP.
ON SUNDAY...TEMPERATURES WILL TREND A GOOD 5-10 DEGREES COOLER
ACROSS THE PLAINS BEHIND A DEEPENING POOL OF COOL AIR. THERE WILL
BE A THETA-E MINIMUM AND SLIGHT DRYING ACROSS MOST OF THE PLAINS
AS WELL...WHICH SHOULD EFFECTIVELY CUT OFF THE NORTHEAST PLAINS
FROM CONVECTION. MEANWHILE...MOUNTAIN AREAS WILL SEE ENOUGH
INSTABILITY FOR ANOTHER ROUND OF SCATTERED SHOWERS AND
STORMS...WITH A FEW POSSIBLY DRIFTING OFF THE FOOTHILLS INTO THE
I-25 CORRIDOR ONCE AGAIN BY LATE AFTERNOON/EVENING. AT THIS
TIME...LOOKS LIKE MAIN THREAT WOULD BE CLOSER TO THE PALMER DIVIDE
AREA HOWEVER AS AIRMASS FARTHER NORTH IS DRYING.
BY MONDAY...LOW LEVEL MOISTURE BEGINS TO RETURN AND INCREASE IN
SOUTH/SOUTHEAST FLOW. MEANWHILE...THETA-E RIDGE BUILDS IN/NEAR THE
FRONT RANGE WITH CAPES INCREASING TO AROUND 1500 J/KG. THIS ALONG
WITH SUFFICIENT SHEAR IN NORTHWEST FLOW ALOFT COULD LEAD TO A FEW
SEVERE STORMS.
ON TUESDAY...LOW LEVEL MOISTURE WILL LIKELY CONTINUE TO POOL ALONG
THE FRONT RANGE WHILE A SHORT WAVE IS STILL BEING ADVERTISED TO
DROP ACROSS THE REGION IN NORTHWEST FLOW ALOFT. THE UPSLOPE
COMPONENT IS ALSO PROGGED BY VARIOUS MODELS TO DEEPEN THROUGH 700
MB...COLLECTIVELY RESULTING IN A GOOD CHANCE OF SHOWERS AND
THUNDERSTORMS. CAPE MAY BE LIMITED BY COOLER TEMPERATURES...BUT
HIGH PRECIPITABLE WATER VALUES AND LIKELY SKINNY CAPE PROFILE
SUGGESTS POTENTIAL FOR HEAVY RAINFALL.
WEDNESDAY AND THURSDAY WILL FEATURE A CONTINUATION OF A COOL AND
SOMEWHAT UNSETTLED WEATHER PATTERN. BEST CHANCE SHOULD REFOCUS TO
THE ELEVATED TERRAIN THOUGH AS AIRMASS ON THE PLAINS WOULD BE MORE
STABLE BEHIND TUESDAYS WAVE AND WITH COOLER TEMPERATURES HOLDING
IN PLACE. PLAINS LOCATIONS MAY STRUGGLE TO REACH 80F BOTH DAYS.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 330 AM MDT FRI JUL 25 2014
SURFACE WINDS HAVE SETTLED INTO A SOUTHERLY DIRECTION AND WILL
STAY THAT WAY UNTIL WEAK COLD FRONT SHIFTS WINDS TO THE NORTHEAST
BETWEEN 14Z-15Z TIME RANGE. EXPECT ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON...WITH BEST CHANCE BETWEEN 21Z-24Z.
WILL ADJUST TIMING OF STORMS SLIGHTLY IN THE NEXT UPCOMING 12Z
ISSUANCE. AGAIN...MAY THREAT WILL BE HEAVY RAIN AND ERRATIC AND
GUSTY WINDS TO 40KT WITH THE STRONGER STORMS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM...BARJENBRUCH
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS GAYLORD MI
305 AM EDT FRI JUL 25 2014
.SYNOPSIS...
ISSUED AT 303 AM EDT FRI JUL 25 2014
HIGH PRESSURE WILL GIVE WAY TO A FAST MOVING SYSTEM TONIGHT AND
SATURDAY. CLOUDS WILL BE ON THE INCREASE TODAY...WITH A CHANCE FOR
SHOWERS AND A FEW THUNDERSTORMS TONIGHT INTO THE START OF THE
WEEKEND. A MUCH STRONGER SYSTEM WILL ARRIVE TO END THE WEEKEND...
BRINGING BETTER POTENTIAL FOR SHOWERS SUNDAY AND SUNDAY NIGHT. A
RETURN TO MUCH BELOW NORMAL TEMPERATURES ON MONDAY...WITH ONLY A
SLOW MODERATION EXPECTED THROUGH THE REMAINDER OF THE WEEK.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 303 AM EDT FRI JUL 25 2014
...MORE CLOUDS AND A SHADE WARMER WITH STORM CHANCES TONIGHT...
IMPACTS: LIGHTNING...BUT NO SEVERE WEATHER EXPECTED.
CURRENT WEATHER AND SYNOPTIC PATTERN:
BROAD UPPER RIDGING SEEN OVER THE SW PART OF THE COUNTRY WHILE
TROUGHING IS STILL THE THEME OVER THE EASTERN CONUS. THE RIDGING HAS
BEEN SQUASHED DUE TO A WRAPPED UP CLOSED LOW DRIFTS ACROSS SW
CANADA. THIS HAS INDUCED LOW PRESSURE OVER EASTERN CANADA AND THE
NRN PLAINS. AN AXIS OF DEEP THETA-E AIR...LEADING EDGE OF STEEP
LAPSE RATES ALOFT (6.5C/KM-7.5C/KM) AND LLJ (45-55KT) CONVERGENCE
AHEAD OF THE PLAINS SFC LOW HAS RESULTED IN POCKETS OF SHOWERS AND
STORMS IN THE DAKOTAS DOWN TO NE. CLOSER TO HOME...AREA VAD WIND
PROFILES AND RUC ANALYSIS SHOWING A TROUGH AXIS AND H8 MOISTURE
ADVECTION FROM THE ARROWHEAD OF MN DOWN THROUGH WISCONSIN. THERE
WERE A FEW ELEVATED RETURNS...BUT ONLY A FEW SPRINKLES HITTING
GROUND PER AREA OBS. OVER NRN MICHIGAN...WE ARE STILL UNDER THE
INFLUENCE OF SFC HIGH PRESSURE...BUT THOSE SAME VAD WIND PROFILES
SHOW THAT THIS HAS SHIFTED JUST EAST OF US WITH A RETURN TO A SW
WIND. AIR MASS IS STILL QUITE DRY WITH PWATS RELATIVELY LOWER THAN
ANYWHERE NEARBY. ONLY A BAND OF HIGHER LEVEL CLOUD STREAMING DOWN
THROUGH THE NW FLOW ALOFT. THE DRY AIR AND MOSTLY CLEAR SKIES HAVE
ALLOWED TEMPERATURES TO FALL INTO THE LOWER HALF OF THE 40S IN THE
LOW LYING AREAS...WHILE COASTAL AREAS AND SOME EXPOSED HIGHER
TERRAIN ARE IN THE LOWER HALF OF THE 50S.
SYNOPTIC PATTERN/WEATHER EVOLUTION:
THE SFC HIGH GRADUALLY SINKS OFF TO THE SE TODAY...WHILE THE
SOUTHERLY PRESSURE GRADIENT TIGHTENS AND DRAWS IN MORE LOW LEVEL
MOISTURE THROUGH THE DAY AND NIGHT. THE INITIAL H8 TROUGH AND
MOISTURE ADVECTION WILL DRIFT OVERHEAD TODAY...AND MAYBE SOME
SPRINKLES ARE POSSIBLE EARLY THIS MORNING...BUT DAYTIME MIXING AND
DRYING OF THE LOWER LEVELS WILL MOST LIKELY SEAL OFF ANY CHANCES FOR
SPRINKLES TO HIT GROUND. THE MOISTURE WILL REVEAL ITSELF IN A HIGHER
BASED CUMULUS FIELD...BUT ALSO MAY GET STUCK UNDERNEATH AN INVERSION
IN FCST BFR SOUNDINGS. THIS COULD LEAD TO A PERIOD OF MOSTLY CLOUDY
SKIES...BUT REALLY DOUBT THIS WILL HAVE MUCH AFFECT ON RISING TEMPS
REACHING THE MIDDLE 70S MOST AREAS. THIS INVERSION AND DRY SFC TDS
RESULT IN A PRETTY PRONOUNCED CAPPING FOR THE ENTIRE DAY...WITH
LITTLE TO NO CHANCE FOR AFTERNOON CONVECTION.
THERE ARE DIFFERENCES IN HOW THIS LID EVOLVES OVER THE NIGHT...BUT
WE WILL AT LEAST BE TRENDING TOWARD MORE UNSTABLE CONDITIONS. SOME
SHORTWAVE ENERGY/VORTICITY EJECTS FROM AFOREMENTIONED CLOSED LOW
DRIFTING THROUGH SRN CANADA. THIS FORCING ARRIVES LATE EVENING AND
OVERNIGHT. WEAK LOW PRESSURE AND A WARM FRONT LIFT UP TOWARD/INTO
NRN MICHIGAN. THE SAME FCST BFR SOUNDINGS...IN A SCENARIO LIKE
THIS...WOULD LIKELY ERODE/SUPPRESS THE CAP...UNLIKE THE GFS
SUGGESTION. RATHER...WILL GO WITH SHOWERS AND EMBEDDED
GARDEN-VARIETY THUNDERSTORMS DEVELOPING LATE EVENING/OVERNIGHT.
NOTHING SEVERE ANTICIPATED...AS OUR LAPSE RATES AND OVERALL
INSTABILITY WILL NOT MIRROR CURRENT ENVIRONMENT ACROSS THE NRN
PLAINS. WE WILL ONLY HAVE SEVERAL HUNDRED J/KG MUCAPE WITH LAPSE
RATES ALOFT 6-6.5C/KM. THE GREATEST MUCAPE LIKELY TO BE DOWN AROUND
THE MANISTEE/CADILLAC AREAS...ALSO WHERE SOME ADDITIONAL LIFT
ASSISTANCE WILL BE PROVIDED BY UPPER DIVERGENCE IN SOMEWHAT OF A
DOUBLE JET STRUCTURE. WOULD GO WITH LIKELY CHANCES FOR SEEING
PRECIPITATION...BUT BULK OF INSTABILITY AND LLJ FORCING WILL ONCE
AGAIN BE ACROSS SRN WI/NRN IL/SRN LAKE MICHIGAN. THIS COULD BLOCK US
FROM SEEING SOME OF THE ACTION. REGARDLESS...LIKELY TO BE SOME
PRECIPITATION...BEST DESCRIPTION OF WHICH CAN BE PROVIDED BY LATER
SHIFTS AS THE EVENT UNFOLDS.
LOWS TONIGHT WILL LIKELY BE MILD WITH THICKENING CLOUDS...LOWER HALF
OF THE 60S MOST AREAS.
&&
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 303 AM EDT FRI JUL 25 2014
...RAINY END TO THE WEEKEND/COOL TEMPERATURES ON THE WAY FOR THE
START OF NEXT WEEK...
HIGH IMPACT WEATHER POTENTIAL: NOT A BUNCH. CHANCES FOR A FEW
NON-SEVERE THUNDERSTORMS HEADING THROUGH THE WEEKEND.
PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: WHILE STILL PLENTY OF THE
FINER DETAILS TO WORK OUT...MUCH TALKED ABOUT TRANSITION TO A MORE
MERIDIONAL NOAM UPPER FLOW PATTERN STILL ON TARGET TO DEVELOP HEADING
INTO AND THROUGH NEXT WEEK. NO LINGERING DOUBT MICHIGAN WILL BE
CENTERED IN UNSEASONABLY CHILL PRODUCING TROUGH AXIS...WHICH WILL BE
A SLOW ONE TO DEPART ONCE IT DEVELOPS. PLAYERS FOR SUCH UNUSUAL
DEVELOPMENTS ALREADY ON THE TABLE...WITH LARGE NORTHERN QUEBEC GYRE
SIMPLY STUCK IN PLACE...ALL THE WHILE STRONG PACIFIC SHORTWAVE MAKES
STEADY EAST PROGRESS ACROSS THE SOUTHERN CANADIAN ROCKIES. THE
LATTER WILL SIMPLY REINFORCE AND EXTEND THE FORMER AS IT
SLING-SHOTS AROUND IT THROUGH EARLY NEXT WEEK. COMBINE THAT WITH
DEVELOPMENT OF FULLY MATURE GULF OF ALASKA TROUGH/WEST NOAM RIDGE
COUPLET (NOT TO MENTION ONE REALLY AMPLIFIED ATLANTIC RIDGE)...AND
ONE CAN SEE WHY A PATTERN MUCH MORE RESEMBLING THE COOL SEASON IS
EXPECTED.
PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS THROUGHOUT
AND EVOLUTION OF PERIODIC RAIN CHANCES. THUNDERSTORM POTENTIAL AND
INTENSITY WILL ALSO NEED ADDRESSING THIS WEEKEND.
DETAILS: SATURDAY CONTINUES TO REMAIN A CHALLENGE...WITH TIGHT
THETA-E GRADIENT AND SURGE OF BEST UPPER JET FORCING EXITING STAGE
RIGHT RATHER QUICKLY DURING THE MORNING. LEFT BEHIND WILL BE A MUCH
MORE MOIST LOW LEVEL AIRMASS...WITH DEWPOINTS EXPECTED TO BE UP IN
THE MID AND PERHAPS UPPER 60S. KINDA EXPECT WHAT EVER PUNCHES
THROUGH HERE TONIGHT WILL LARGELY EXIT DURING THE MORNING
HOURS...LEAVING NEXT LOW AMP WAVE AND DIURNAL DRIVEN DESTABILIZATION
TO DRIVE ADDITIONAL SHOWER AND STORM DEVELOPMENT. MOISTURE CROSS
SECTIONS SHOW GOOD TO EXCELLENT MOISTURE DEPTH UP THROUGH H7...WITH
AGGRESSIVE DRYING ABOVE THIS LAYER. MANIPULATING MODEL DERIVED
SOUNDINGS WITH ANTICIPATED DEWPOINTS/TEMPERATURES DOES YIELD
DEVELOPMENT OF UPWARDS OF 1K-1.5K J/KG OF ML CAPE DURING THE
AFTERNOON. THINK THIS MIGHT BE A TOUCH AGGRESSIVE...EXPECTING LOW
LEVELS TO BE NOT QUITE AS SATURATED AS GUIDANCE WOULD SUGGEST. WHILE
BEST DYNAMICS WILL HAVE EXITED...NOT ALL IS LOST...WITH MID LEVEL
JET ROTATING THROUGH THE SOUTHWEST LAKES...COMBINING WITH LAKE
INDUCED LOW LEVEL CONVERGENCE /PARTICULARLY IN NORTHEAST LOWER AND
INTERIOR EASTERN UPPER MICHIGAN/ AND SAID WEAK WAVE. ABOVE
DEFINITELY SUPPORTS SOME ADDITIONAL CONVECTIVE POTENTIAL...
ESPECIALLY IN CLIMATOLOGICALLY FAVORED AREAS. INHERITED FORECAST
ALREADY WELL TRENDED IN THIS DIRECTION...WITH ONLY SOME MASSAGING
NEEDED TO POP/WEATHER GRID. DECENT DEEP LAYER SHEAR OF 30 TO 40
KNOTS LARGELY OFFSET BY LIMITED MID LEVEL LAPSE RATES AND SKINNY
CAPE PROFILE UP THROUGH HAIL GROWTH ZONE. SO...IF STORMS CAN DEVELOP
(A BIG IF)...WOULD EXPECT THEM TO REMAIN BELOW SEVERE LIMITS.
LOSS OF INSTABILITY AND RAPID APPROACH OF SHORTWAVE RIDGING EXPECTED
TO BRING A MOSTLY DRY SATURDAY NIGHT. RATHER VIGOROUS CURRENT
SOUTHERN CANADA WAVE QUICKLY FOLLOWS FOR SUNDAY...AND WHEN COMBINED
WITH GOOD SLUG OF LEFT EXIT REGION UPPER JET DYNAMICS...LOOKS TO
BRING A RATHER WIDESPREAD SHOWER EVENT SUNDAY INTO SUNDAY NIGHT.
SYSTEM EVEN LOOKS TO TAKE ON COLD SEASON CHARACTERISTICS...WITH MORE
STEADY RAIN POTENTIAL IN FAVORED NORTH SIDE DEFORMATION FIELD. SOME
THUNDER THREAT REMAINS SUNDAY WITH OPPORTUNITY FOR SOME
DESTABILIZATION BEFORE BETTER FORCING ARRIVES.
TROUGHING DIGS IN AND STAYS THERE-ON-AFTER...PERHAPS LASTING THROUGH
ALL OF NEXT WEEK. COLDEST ANOMALIES EXPECTED TO SLIDE JUST OFF TO
OUR NORTHEAST. THAT SAID...COLD AIR ADVECTION ON FRONTSIDE OF
SPRAWLING NORTHERN PLAINS HIGH WILL BE IMPRESSIVE INDEED...ONCE
AGAIN NOT ALLOWING TEMPERATURES TO GET OUT OF THE 60S ON MONDAY. A
VERY SLOW MODERATION TO FOLLOW...WITH HIGHS WARMING A FEW DEGREES
EACH DAY THROUGH THURSDAY (EVEN BY THURSDAY...HIGHS WILL STILL BE A
FEW DEGREES BELOW NORMAL). DESPITE TROUGHING...JUST NOT OVERLY
IMPRESSED WITH RAIN CHANCES AFTER SUNDAY NIGHTS WAVE PASSAGE. DEEP
LAYER FLOW WILL REMAIN NORTH TO NORTHWEST...AND MID LEVEL
TEMPERATURE REALLY NEVER GET TOO COLD...REACHING THE NEGATIVE UPPER
TEENS AT H5 LATER MONDAY INTO TUESDAY. OF COURSE...ANY WAVES
ROTATING THROUGH WILL ONLY HELP THE SHOWER CAUSE...BUT TIMING AND
MAGNITUDE OF SUCH NOT POSSIBLE TO DETERMINE JUST YET. NO REASON TO
CHANGE THAT WHICH WAS INHERITED...FEATURING JUST ISOLATED/LOW CHANCE
SHOWER POTENTIAL DURING THE DAYTIME HOURS. THIS WILL CHANGE...OF
COURSE...BUT PLENTY OF TIME TO FIGURE THOSE DETAILS OUT IN THE
COMING DAYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 136 AM EDT FRI JUL 25 2014
VFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF SITES THRU
FRIDAY NIGHT. SCT CU AND INCREASING MID CLOUDS ON FRIDAY WILL LEND
TO PARTLY TO MOSTLY CLOUDY SKIES. CHANCES OF SHOWERS AND
THUNDERSTORMS WILL BEGIN TO INCREASE AFTER 00Z SATURDAY AHEAD OF A
WEAK COOL FRONT...BUT CHANCES ARE TOO SMALL TO INCLUDE IN THE TAF AT
THIS POINT. LIGHT/VARIABLE WINDS OVERNIGHT INTO THE MORNING HOURS
WILL BECOME S/SW AT AROUND 10 KTS BY LATE MORNING.
&&
.MARINE...
ISSUED AT 303 AM EDT FRI JUL 25 2014
SW WINDS WILL INCREASE HEADING THROUGH TONIGHT...AHEAD OF SFC LOW
PRESSURE AND A WARM FRONT...WHICH WILL BRING AREAS OF SHOWERS AND
GARDEN-VARIETY STORMS TO THE GREAT LAKES. NOTHING SEVERE....AND
WINDS TO REMAIN ABOVE ADVISORY LEVELS. EXPECTING NO MORE THAN
20KTS..WHICH WILL LARGELY RESIDE ACROSS LAKE MICHIGAN. WINDS REMAIN
UNDER ADVISORY LEVELS SATURDAY AND SUNDAY IN WEAK GRADIENT. ANOTHER
SFC LOW CROSSES SUNDAY MORNING WITH A BETTER CHANCE FOR SHOWERS AND
STORMS...AND MUCH COOLER AIR SET TO ARRIVE THROUGH THE DAY SUNDAY
AND SUNDAY NIGHT.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SYNOPSIS...MSB
SHORT TERM...SMD
LONG TERM...MSB
AVIATION...MR
MARINE...SMD
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
330 AM CDT FRI JUL 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT FRI JUL 25 2014
EARLY MORNING THUNDERSTORMS CONTINUED TO DEVELOP ACROSS THE REGION
THIS MORNING FUELED BY THE VEERING WINDS ASSOCIATED WITH THE THETA_E
ADVECTION IN CONNECTION WITH THE LOW LEVEL JET. OVER THE NEXT FEW
HOURS THIS 40KT JET WILL BECOME MORE FOCUSED ACROSS SOUTHERN...AND
EVENTUALLY SOUTHEASTERN MN. AS A RESULT PRECIPITATION WILL CONTINUE
TO DEVELOP FOR THE NEXT FEW HOURS...BUT SHOULD GRADUALLY WANE
SHORTLY AFTER SUNSET AS IT ENTERS WESTERN WI.
EARLIER RUNS OF THE RAP MISSED THE PRECIP THAT DEVELOPED IN
NORTHEAST SD...SO IT IS NO SURPRISE THAT HIGHRES MODELS HAVE BEEN
STRUGGLING TO GET A HANDLE ON THE TWO AREAS OF PRECIP THAT DEVELOPED
EARLIER. AS A RESULT MOST OF THE RUNS HAVE BEEN ALL BUT DISCARDED.
THE 25.06HRRR HAS FINALLY CAUGHT UP AND IT SUPPORTS THE IDEA OF
CONTINUED CONVECTION THIS MORNING...BUT WITH A WEAKENING TREND AFTER
11Z. THE SEVERE WEATHER THREAT IS VERY LOW GIVEN THE DEEP STABLE
LAYER BENEATH THE ELEVATED CAPE...AND ONLY MARGINAL 30-35KTS OF
EFFECTIVE SHEAR.
LOOKING AHEAD...SKIES SHOULD CLEAR BEHIND THE MORNING PRECIP
YIELDING ANOTHER MUGGY AFTERNOON AS DEWPOINTS CLIMB BACK TO NEAR
70F. INCREASED TEMPS SLIGHTLY ACROSS WEST OF I35...AND RAISED
DEWPOINTS AS WELL. OVERNIGHT NORTHWESTERLY WINDS WILL PUSH A COLD
FRONT THROUGH THE REGION SENDING DEWPOINTS BACK INTO THE UPPER 50S
BY SATURDAY MORNING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 AM CDT FRI JUL 25 2014
THE WEEKEND STARTS OUT ON A MILD NOTE...AS THE AREA REMAINS
SANDWICHED BETWEEN A SOUTHERN CONUS RIDGE TO THE SOUTH...AND A
MID LEVEL LOW TO THE NORTH IN SASKATCHEWAN/MANITOBA. THE RESULT WILL
BE SLIGHTLY WARMER THAN NORMAL HIGHS IN THE MID 80S ON
SATURDAY...FOLLOWED BY INCREASING PRECIPITATION CHANCES INTO
SUNDAY AS THE AFOREMENTIONED LOW DROPS SOUTH-SOUTHEAST FROM
SOUTHERN MANITOBA. AS IS COMMON WITH THESE TYPES OF
LOWS...PRECIPITATION CHANCES APPEAR THE HIGHEST FROM CENTRAL MN
INTO WI...WHERE FORCING/MOISTURE IS DEEPER. EXPECT SHOWERS WITH
ISOLATED THUNDERSTORMS ON SUNDAY...PARTICULARLY DURING THE AFTERNOON
HOURS AS DIURNAL HEATING AIDS DESTABILIZATION.
NEXT WEEK STARTS OUT ON A DRY AND MILD NOTE AS THE WEEKEND LOW
SHIFTS SOUTHEAST AND A BROAD SURFACE RIDGE BUILDS ACROSS THE
CENTRAL CONUS. THE LOCAL AREA REMAINS CRAMMED BETWEEN WESTERN
RIDGING AND EASTERN TROUGHING AT THE MID TO UPPER LEVELS OF THE
ATMOSPHERE...YIELDING COOLER THAN NORMAL HIGHS FROM MONDAY THROUGH
WEDNESDAY MOSTLY IN THE 70S...AND LOWS IN THE 50S.
THURSDAY AND FRIDAY BRING THE NEXT CHANCE FOR MEASURABLE
PRECIPITATION AS SHORTWAVE ENERGY BEGINS TO TRICKLE SOUTH ON THE
WESTERN PERIPHERY OF THE EASTERN CONUS TROUGH. CHANCES ARE NOT
HIGH AT THIS POINT GIVEN MODEST FORCING AND MOISTURE...BUT
SUFFICIENT FOR THE INCLUSION OF 20-30 POPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1059 PM CDT THU JUL 24 2014
CONFIDENCE HAS INCREASED QUITE A BIT IN THE LAST FEW HOURS WITH
REGARD TO THE PRECIPITATION EVOLUTION OVERNIGHT INTO EARLY FRIDAY
MORNING. EXPECT TO SEE SHOWERS AND THUNDERSTORMS RAPIDLY DEVELOP
AROUND 07Z ACROSS SOUTHWESTERN MN AND EXPAND EASTWARD IN THE HOURS
FOLLOWING...REACHING STC AROUND 09Z...MSP AROUND 10Z...AND RNH BY
11Z. SOME THUNDER MAY ACCOMPANY THIS PRECIP...ESPECIALLY ACROSS
SOUTHERN AND WESTERN MN. ANY SHOWER/STORM ACTIVITY SHOULD DIMINISH
2 TO 4 HOURS AFTER IT BEGINS. FOLLOWING THE PRECIP...MODELS INSIST
ON DEVELOPING IFR OR MVFR CIGS. NOT CONFIDENT IN THIS SCENARIO AS
THEY HAVE OVERDONE THESE EVENTS TIME AND TIME AGAIN THIS SUMMER.
WILL CONTINUE THE SCT MENTION AROUND 2 KFT BEFORE CIGS RISE TOWARD
4 KFT BY AFTERNOON.
KMSP...CURRENT PROJECTIONS INDICATE PRECIP WILL ARRIVE AT MSP
AROUND 10Z AND PERSIST THROUGH ABOUT 12 OR 13Z. CONFIDENCE HAS
INCREASED AND BROUGHT BACK THE PREVAILING GROUP FOR THIS
TIMEFRAME.
/OUTLOOK FOR KMSP/
SAT...VFR. WINDS WSW AT 5-10KTS.
SUN...VFR. CHANCE SHRA/MVFR CIGS. WINDS NW AT 10-15 KTS.
MON...VFR. WINDS N 5 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...LS
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1106 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 804 PM CDT THU JUL 24 2014
ONLY UNTIL RECENTLY HAVE MODELS BEGUN TO LATCH ONTO THE CURRENT
SITUATION. HRRR AND NOW HOPWRF HAVE BEGUN TO CONVERGE TOWARD A
SOLUTION WHICH ALLOWS CONVECTION OVER THE WESTERN DAKOTAS AND
EASTERN MONTANA TO EXPAND EASTWARD RAPIDLY DURING THE LATE EVENING
AND SPILL INTO MINNESOTA OVERNIGHT. THE GLOBAL MODELS THROUGH 18Z
DID NOT HANDLE THIS IDEA WELL...SO WHILE CONFIDENCE HAS BEEN QUITE
LOW IT IS STARTING TO INCREASE. IT REMAINS TO BE SEEN WHETHER THE
00Z GLOBAL MODELS WILL LATCH ONTO THIS SOLUTION...BUT GIVEN THE
RECENT TRENDS IN THE CAMS THERE IS A PRETTY GOOD CHANCE.
STRONG MOISTURE ADVECTION OVER EASTERN SOUTH DAKOTA/NEBRASKA WHERE
PW VALUES ARE 1.5 TO 1.9 INCHES WILL CONTINUE TO IMPROVE OVERNIGHT
AS A 40 TO 50 KT LLJ DEVELOPS. THIS LLJ WILL THEN VEER EASTWARD INTO
SWRN MN OVERNIGHT AND FOCUS THIS MOISTURE TRANSPORT OVER THE MPX
CWA. A STRONGLY TO EXTREMELY UNSTABLE AIRMASS TO THE WEST SHOULD
MAINTAIN THIS DEVELOPING MCS AS IT CONTINUES EAST FOR THE NEXT 12
HOURS. THUS...THE SOLUTION KEEPING ACTIVITY CONFINED TO IOWA /A
LA NAM...GFS...AND CMC/ IS LOOKING LESS AND LESS LIKELY. INCREASED
POPS ACROSS CENTRAL MN INTO THE LIKELY RANGE AND THE TIMING WAS
BASED ON THE LATEST HRRR/HOPWRF.
ANY SEVERE THREAT WILL BE DETERMINED BY HOW FAR EAST THE EML AND
ASSOCIATED INSTABILITY CAN PROGRESS. BEST CHANCE FOR ANY SEVERE
WOULD BE ACROSS WRN MN...CLOSEST TO THE EML. LARGE HAIL WOULD BE
THE PRIMARY CONCERN.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 233 PM CDT THU JUL 24 2014
SHORT TERM CONCERNS REMAIN COVERAGE OF THUNDER OVERNIGHT INTO
FRIDAY. ALSO...CHANCE OF LARGE HAIL MAINLY LATER TONIGHT INTO SOUTH
CENTRAL MN WITH SOME SEVERE POTENTIAL LINGERING INTO FRIDAY AHEAD OF
FRONT.
UPPER RIDGE IS BEGINNING TO MOVE EAST WITH ONE IMPULSE DROPPING
SOUTHEAST OVER WESTERN MINNESOTA AND THE NEXT WAVE LIFTING INTO
NORTHWEST NODAK AND SOUTHERN MANITOBA. IT APPEARS THE INITIAL WAVE
WILL DROP SOUTHEAST THIS EVENING ALONG THE EASTERN PERIPHERY OF THE
INSTABILITY GRADIENT TO THE WEST AND THE EDGE OF LOW LEVEL WAA/STEEP
MID LEVEL LAPSE RATES. MODELS DIVERGE ON DEVELOPMENT THEREAFTER...
WITH SEVERAL HIRES MODELS INDICATING CANADIAN SYSTEM TAKES OVER AND
DROPS SOUTHEAST OVERNIGHT. STILL SOME POTENTIAL OF LLJ DRIVING
CONVECTION INTO MAINLY SOUTH CENTRAL MN LATE. WILL CARRY HIGHER
POPS TO THE SOUTH ONCE AGAIN...IN SPIRIT WITH THE PREVIOUS
FORECAST. SHOULD SEE SOME QPF MOVE THROUGH THE MOST OF AREA.
FRIDAY STILL SEE SOME POTENTIAL OF ISOLATED/WIDELY SCATTERED
CONVECTION DEVELOPING ALONG THE FRONT AS IT MOVES ACROSS THE EASTERN
PORTION OF THE AREA INTO THE AFTERNOON. WILL HOLD ONTO SOME LOW END
POPS FOR THIS POTENTIAL. INSTABILITY ALONG THE FRONT DOES INCREASE
DURING THE DAY BUT LOW LEVEL CONVERGENCE REMAINS WEAK. MUCH OF THE
HIGH END FORCING IS DRIVEN EAST DURING THE MORNING AS WELL.
TEMPERATURES SHOULD WARM INTO THE MID 80S TO THE SOUTHWEST WITH MIX
WITH THE WEAK FRONT AND UPPER 70S/LOWER 80S ELSEWHERE.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 233 PM CDT THU JUL 24 2014
MAIN CONCERN IN THE EXTENDED PERIOD IS WHETHER SHRA/TSRA DEVELOP
FURTHER SOUTHWARD ACROSS MN THAN EXPECTED FOR LATE SAT AFTN/EARLY
SUNDAY AS A STRONG...AND UNUSUAL UPPER LOW FOR THIS TIME OF YEAR
MOVES EAST-SE ACROSS THE NORTHERN PLAINS...AND INTO THE WESTERN
GREAT LAKES BY SUNDAY. WILL FOLLOW PREVIOUS FORECAST WITH THE MAIN
AREA OF SHRA ACROSS CENTRAL MN/EC MN AND WC WI WHERE BOTH UPPER
LEVEL ENERGY AND HIGHER RH FIELDS ARE EVIDENT. K-INDEX AND 85H
SHOWALTER INDEX FIELDS INDICATED MAINLY SHRA WITH SOME EMBEDDED
TSRA FOR THE TYPICAL DIURNAL TIME FRAME. SUNDAY MORNING/AFTN WILL
LIKELY BE BREEZY AS THE SFC LOW DEEPENS AS IT MOVES SE ACROSS THE
WESTERN GREAT LAKES IN RESPONSE TO THE UPPER JET.
NO CHGS IN THE EXTENDED PERIOD BEYOND THIS WEEKEND WITH BOTH THE
EC/GFS ADVERTISING A STRONG UPPER RIDGE BUILDING OFF THE EAST
COAST OF NORTH AMERICA WITH A DEEPENING LONG WAVE TROUGH ACROSS
THE EASTERN 1/3 OF THE CONUS. THIS WILL KEEP OUR REGION COOLER
THAN NORMAL AND MAINLY DRY. ALTHOUGH COOLER TEMPS ARE
EXPECTED...STANDARD ANOMALIES ARE NOT TOO IMPRESSIVE COMPARED TO
THE DEEP SE U.S. WHERE ANOMALIES COULD DROP TO 2-3 BLW NORMAL.
FOR COMPARISON...OUR REGION WILL BE SLIGHTLY COOLER...BUT STILL
NICE FOR LATE JULY/EARLY AUGUST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1059 PM CDT THU JUL 24 2014
CONFIDENCE HAS INCREASED QUITE A BIT IN THE LAST FEW HOURS WITH
REGARD TO THE PRECIPITATION EVOLUTION OVERNIGHT INTO EARLY FRIDAY
MORNING. EXPECT TO SEE SHOWERS AND THUNDERSTORMS RAPIDLY DEVELOP
AROUND 07Z ACROSS SOUTHWESTERN MN AND EXPAND EASTWARD IN THE HOURS
FOLLOWING...REACHING STC AROUND 09Z...MSP AROUND 10Z...AND RNH BY
11Z. SOME THUNDER MAY ACCOMPANY THIS PRECIP...ESPECIALLY ACROSS
SOUTHERN AND WESTERN MN. ANY SHOWER/STORM ACTIVITY SHOULD DIMINISH
2 TO 4 HOURS AFTER IT BEGINS. FOLLOWING THE PRECIP...MODELS INSIST
ON DEVELOPING IFR OR MVFR CIGS. NOT CONFIDENT IN THIS SCENARIO AS
THEY HAVE OVERDONE THESE EVENTS TIME AND TIME AGAIN THIS SUMMER.
WILL CONTINUE THE SCT MENTION AROUND 2 KFT BEFORE CIGS RISE TOWARD
4 KFT BY AFTERNOON.
KMSP...CURRENT PROJECTIONS INDICATE PRECIP WILL ARRIVE AT MSP
AROUND 10Z AND PERSIST THROUGH ABOUT 12 OR 13Z. CONFIDENCE HAS
INCREASED AND BROUGHT BACK THE PREVAILING GROUP FOR THIS
TIMEFRAME.
/OUTLOOK FOR KMSP/
SAT...VFR. WINDS WSW AT 5-10KTS.
SUN...VFR. CHANCE SHRA/MVFR CIGS. WINDS NW AT 10-15 KTS.
MON...VFR. WINDS N 5 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...BORGHOFF
SHORT TERM...DWE
LONG TERM...JLT
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
346 AM CDT Fri Jul 25 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 330 AM CDT Fri Jul 25 2014
Convective trends and the extent of pops are the biggest forecast
challenge today. Thunderstorms have blossomed within the last
several hours across central Iowa at the terminus of a stout
southwesterly LLJ, and along the eastern periphery of elevated
instability, deeper moisture and steep mid level lapse rates.
Short range guidance shows the LLJ slowly veering this morning,
providing favorable moisture transport and forcing as the flow
aloft and northwestely deep layer shear steer the activity east
and southeastward. The HRRR runs since 01Z have been very emphatic
supporting this scenario bringing showers and thunderstorms into
northeast Missouri and west central Illinois. I have increased
pops into the likely range in this area tapered to slight chances
just north of interstate 70. Believe that most of this activity
will be east of the MS river by early afternoon and exiting the
CWA shortly thereafter. This activity will likely delay/impeed the
northward retreat of the warm front, however in central MO there
should be no issue where highs will be around 90.
Glass
.LONG TERM: (Tonight through Thursday)
Issued at 330 AM CDT Fri Jul 25 2014
The warm front should have exited the entire CWA by early evening
while the upstream cold frontal system will be slowly advancing
and stretching from the upper MS valley into the central Plains.
High heights aloft and warm mid level temperatures should suppress
any surface-based storm development within the large warm sector
spanning the CWA, however the area will remain subject to an
elevated shower and thunderstorm threat. While there is no defined
focus for thuunderstorms, a westerly LLJ will be poised across the
area in conjunction with steep mid level lapse rates and good
elevated instability supporting a least a chance pop. These same
unfocused conditions will exist on Saturday morning. The set-up
should improve on Saturday afternoon. Strong surface heating
should yield temperatures well into the 90s with dew points in the
70s. This will result in afternoon heat indices in the 100-104 degree
range, just below advisory criteria. We will need to monitor this
closely as just a bit higher dew points and/or temperatures and a
heat advisory will be warranted. The aforementioned conditions along
with the presence of steep mid level lapse rates will yield very
unstable conditions during the afternoon/evening. There are
indications that the combo of heating and a disturbance in the
west northwest flow aloft should sufficiently weaken the cap
allowing for robust thunderstorm development along the west-east
oriented front stretching in the vicinity of far northern MO
through central IL into the OH valley. How far west development
occurs is uncertain but height falls/cooling aloft on Saturday
night could aid this process. Deep layer shear and instability is
quite favorable for organized severe with damaging winds the most
apparent severe threat at this time. I have some low pops on
Sunday ahead of the advancing front, but the overall threat of
precipitation will be lower as compared to the Saturday night.
Cooler and drier air will advect in ernest into the area on Sunday
night with a large surface high settling into the Nation`s
midsection on Monday. An unseasonably deep upper trof over eastern
NOAM through the first part of next week will keep the large
surface high in control and allow for another period of below
average temperatures as we exit July and head into August.
Glass
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1111 PM CDT Thu Jul 24 2014
VFR fcst with the only real concern being new convection fcst to
dvlp around 8-9Z across cntrl IA out ahead of the ongoing
convection across ern NEB. This new activity is fcst to drop SE
during the early mrng hrs making it as far SE as NE MO and W cntrl
IL by daybreak. There is some question as to how far SE this
precip will be able to push before dssptng...but given how far the
precip from earlier this evng made it...wouldn`t be at all
surprised if it made it all the way into the STL metro area by
17-18Z. Given the uncertainty in intensity...coverage and timing have
left the metro sites dry for now. After this activity passes SE of
the terminals...expect srly winds with just some left over
mid/high clouds
Specifics for KSTL:
VFR fcst with the possibility of precip mvng into the terminal around
noon. Convection is fcst to dvlp across IA after midnight and then
track SE thru the mrng possibly reaching the terminal by very late
mrng. There is still some question as to whether the precip will
hold together that long...hence have a dry fcst attm. This is
something that will obviously need to be monitored for future
updates. Otherwise...expect srly winds with mid/high level
cloudiness.
2%
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
100 AM CDT FRI JUL 25 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 332 PM CDT THU JUL 24 2014
FAIRLY QUIET DAY WITH MOSTLY SUNNY SKIES AS THE UPPER LEVEL RIDGE
AXIS CONTINUES TO MOVE OVERHEAD. 12Z SUBJECTIVE UPPER AIR ANALYSIS
IN ADDITION TO RAP ANALYSIS SHOWS A STOUT MID LEVEL WARM POCKET OVER
THE HIGH PLAINS REGION. THIS CONTINUES TO DRIFT EWD WHICH WOULD
TYPICALLY CAP OFF ANY POTENTIAL THUNDERSTORM DEVELOPMENT. THIS BEING
SAID...AN AREA OF CONVECTION HAS MANAGED TO DEVELOP OVER THE
NEBRASKA PANHANDLE AND PORTIONS OF NORTHEAST COLORADO IN ADVANCE OF
A WEAK VORT MAX. LATEST RUNS OF THE HRRR AND RAP INDICATE THIS
CONVECTION HOLDING ON AND SPREADING EAST THROUGHOUT THE LATER
EVENING HOURS. AS A RESULT...WILL HOLD ONTO SMALL POPS ACROSS THE
NORTHERN CWA.
ATTENTION THEN TURNS TO HEAT TOMORROW. HIGHS SHOULD REACH THE 100
DEGREE MARK ACROSS THE KANSAS COUNTIES WITH UPPER 90S SOUTH OF
INTERSTATE 80. COMBINED WITH SFC DEWPOINTS IN THE UPPER 60S...WE
SHOULD APPROACH HEAT INDICES IN THE 105+ RANGE. AS A RESULT...WILL
GO AHEAD AND ISSUE A HEAT ADVISORY FOR PORTIONS OF SOUTH CENTRAL
NEBRASKA AND ALL THE NORTH CENTRAL KANSAS COUNTIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 332 PM CDT THU JUL 24 2014
ANOTHER HOT DAY IS EXPECTED ON SATURDAY WITH POTENTIAL FOR HEAT
ADVISORY CRITERIA AGAIN. WILL LET LATER SHIFTS EVALUATE FOR
ADDITIONAL HEADLINES. A COLD FRONT WILL DROP OVER THE AREA SATURDAY
NIGHT WITH HIGH PRESSURE BUILDING ACROSS THE AREA SUNDAY INTO
MONDAY. MUCH COOLER AND DRIER AIRMASS WILL ALLOW TEMPS TO DROP INTO
THE LOW 80S FOR HIGHS AND LOW 60S FOR LOWS.
RETURN FLOW WILL SET UP EARLY NEXT WEEK WHILE A SERIES OF UPPER
LEVEL SHORTWAVES ARE FORECAST TO PASS THROUGH THE REGION IN
MID/UPPER LEVEL NORTHWESTERLY FLOW. MODEL CONSENSUS HAS PUT AT LEAST
A SLIGHT CHANCE OR CHANCE OF TSTMS FROM MONDAY NIGHT THROUGH
THURSDAY. ALTHOUGH WIDESPREAD CONTINUOUS PCPN IS NOT
ANTICIPATED...WILL LEAVE THESE CHANCES IN DUE TO UNCERTAINTY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1255 AM CDT FRI JUL 25 2014
BIGGEST CONCERN IS LOW-LEVEL WIND SHEAR OVERNIGHT INTO EARLY
FRIDAY MORNING. ALSO...WIND WILL EVENTUALLY VEER OVERNIGHT AS A
COLD FRONT APPROACHES FROM THE NORTH. VFR CONDITIONS ARE FORECAST.
ANY THUNDERSTORMS SHOULD REMAIN NORTH AND EAST OVERNIGHT...AND
THUNDERSTORMS FRIDAY NIGHT WILL REMAIN NORTH AND MOSTLY DURING THE
OVERNIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
NEZ063-064-074>077-083>087.
KS...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
KSZ005>007-017>019.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1130 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 1130 PM CDT THU JUL 24 2014
CLUSTER OF THUNDERSTORMS NOW MOVING INTO NORTHEAST NEBRASKA SEEMS
TO MAINTAINING ITSELF BASED ON RADAR/LIGHTNING/SATELLITE TRENDS...
AND COULD VERY WELL CONTINUE ROLL EAST SOUTHEAST AS IT REMAINS
WITHIN A LOW LEVEL MOIST JET AXIS TONIGHT. MOST RECENT HRRR MODEL
RUNS SEEM TO CAPTURE THIS TREND WELL...THUS THE FORECAST WAS
UPDATED TO AT LEAST INCLUDE SOME CHANCE OF RAIN ACROSS THE
REMAINDER OF THE FORECAST AREA. BEST CHANCES WILL LIE ALONG THE
PLATTE RIVER BASIN. FREEZING LEVEL IS AROUND 15000 FEET AND WET
BULB ZERO LEVELS AROUND 11600 FEET. THUS LARGE HAIL WILL BE HARD
TO ACHIEVE...BUT SMALL HAIL MAY BE POSSIBLE IN THE STRONGER STORMS.
30 TO 45 MPH GUSTY WINDS WILL BE POSSIBLE AS STORMS MOVE IN.
A COUPLE OF SPOTTY SHOWERS WERE ALSO TRYING TO DEVELOP AROUND THE
KSUX AREA...AND THIS MAY BE THE PRECURSOR TO ACTIVITY THAT WILL
MOVE THROUGH CENTRAL IOWA...BUT THE WESTERN EDGE COULD ALSO CLIP
OUR COUNTIES IN WESTERN IOWA AS WELL.
UPDATE ISSUED AT 847 PM CDT THU JUL 24 2014
ALTHOUGH 00Z OMAHA SOUNDING AND SPC MESO-ANALYSIS PAGE INDICATED A
FORMIDABLE CAP/WARM MID LEVEL TEMPERATURES ACROSS THE
FA...ELEVATED CONVECTION CONTINUED TO DEVELOP TOWARD NWRN ZONES
SHORTLY BEFORE 02Z. RADAR TRENDS WOULD PUT SCATTERED ACTIVITY
TOWARD ALBION BY 03-04Z. UPDATED GRIDS/ZONES TO INCLUDE POPS AS
FAR EAST AS LINCOLN TO NEAR FREMONT THROUGH 07Z BEFORE PRECIP
POSSIBLY SHUTS OFF DUE TO ITS FARTHER EAST REMOVAL OF ITS ELEVATED
ROOTS. HOWEVER...CONFIDENCE IS LOW IN THIS AND SOME SHORT RANGE
MODELS BROUGHT AN MCS ACROSS LINCOLN/OMAHA TONIGHT. SECOND AREA
WHERE DEVELOPMENT IS POSSIBLE LATER WOULD NEAR EDGE OF WARMER
TEMPS ALOFT/CAP...ACROSS FAR ERN ZONES. NO MENTION WAS MADE THERE
JUST YET. NEEDLESS TO SAY...RADAR IMAGERY WILL CONTINUED TO BE
MONITORED FOR ADDITIONAL UPDATES.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 316 PM CDT THU JUL 24 2014
MOST OF THE SENSIBLE WEATHER THIS FORECAST IS IN THE SHORT TERM.
TSRA ASSOCIATED WITH PERSISTENT WAA PATTERN CONTINUE TO RIDE THE
EDGE OF THE INCREASING CAP THIS AFTERNOON AND MAY CONT TO AFFECT
A SMALL PORTION OF OUR WESTERN IOWA COUNTIES FOR A COUPLE OF MORE
HOURS BEFORE THE CAPPING INVERSION BECOMES TO STRONG FOR OUR CWA.
OTHER CONVECTION WILL LIKELY GET GOING OVER THE HIGH PLAINS
ASSOCIATED WITH A LEE TROUGH WHERE TEMPERATURES HAVE SOARED INTO
THE LOWER 100S...AND LOW-LEVEL LAPSE RATES HAVE STEEPENED
SUFFICIENTLY TO ALLOW FOR CI. SOME HIGH-RES GUIDANCE INDICATES
THAT SOME OF THIS ACTIVITY MAY WANT TO TRY AND MAKE IT INTO NE NEB
LATE THIS EVENING BUT WE FEEL THIS APPEARS A BIT OVERDONE GIVEN
THE INCREASE CAP AHEAD OF THIS AREA OF DEEP MIXING. THUS IT SHOULD
BE A FAIRLY QUIET BUT WARM NIGHT WITH BREEZY SOUTH WINDS.
THE MODELS ARE IN BETTER AGREEMENT TODAY IN THE CDFNT TIMING FOR
FRI AS THE NAM HAS SLOWED THE PROGRESSION OF THE FRONT CLOSER TO
THE EC/GEM OF YESTERDAY. THUS HIGHS IN THE CNTRL/SRN CWA SHOULD
CLIMB INTO THE MID AND UPPER 90S...AND WITH DEW POINTS IN THE
LOWER TO MID 70S...WE WILL LIKELY SEE A PERIOD OF HEAT ADVISORY
CRITERIA BEING MET. THE FRONTAL BOUNDARY STILL LOOKS LIKE IT WILL
REMAIN CAPPED OVER THE FA GIVEN THE WARM MID-LEVEL TEMPERATURES
AND LACK OF LARGE-SCALE FORCING FOR ASCENT. THE COLD FRONT WILL
STALL NEAR THE KS/NEB BORDER ON FRI NIGHT WITH THE LOW-LEVEL FLOW
TURNING TO THE EAST OVERNIGHT KEEPING MOISTURE LOCKED INTO THE FA.
TSRA MAY STILL DEVELOP IN THE UPSLOPE REGIME OVER THE HIGH PLAINS
FRI AFTN AND ATTEMPT TO ROLL ALONG THE EDGE OF THE MID LEVEL
CAP/INSTABILITY GRADIENT OVER NRN NEB/SRN SD FRI NIGHT. THE
NAM/EC ARE THE STRONGEST WITH THIS PATTERN AS THE GFS SCOURS OUT
MORE OF THE MOISTURE POST FRONTAL. CURRENTLY WE PREFER MORE THE
EC/NAM LOOK TO THE PATTERN AND WILL CONT WITH SOME POPS AFTER 09Z
FRI NIGHT. SOME CONVECTION MAY TRY AND LINGER INTO THE DAY ON SAT
OR REGENERATE GIVEN THE RESIDUAL MOISTURE AND INVERTED TROUGH
SLIDING SEWD THROUGH THE CWA. CONFIDENCE IS LOWER DURING THIS
PERIOD...BUT SYNOPTIC PATTERN DOES FAVOR SOME CONVECTION ON
SAT...EITHER A CONTINUATION OF OVERNIGHT ACTIVITY OR NEW
DEVELOPMENT ALONG THE INVERTED TROUGH DURING THE AFTN. EFFECTIVE
SHEAR AND INSTABILITY WOULD SUPPORT AN ISO SVR THREAT IF THIS
PATTERN ENDS UP DEVELOPING. ONCE THE INVERTED TROUGH MOVES THROUGH
THE SOUTHERN CWA ON SAT EVENING THE CONVECTIVE CHANCES LOOK TO END
FOR THE REST OF THE SHORT TERM WITH MUCH COOLER AND DRIER AIR
MOVS INTO THE AREA FOR SUNDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 316 PM CDT THU JUL 24 2014
MOST OF THE EXTENDED PERIOD STILL APPEARS QUIET WITH SEASONABLY
COOL AIR IN PLACE WITH NORTHWEST FLOW ALOFT. HIGHS IN THE UPPER
70S TO LOWER 80S APPEAR LIKELY FOR MON/TUE BEFORE TEMPERATURES
START TO SLOWLY MODERATE TOWARD NORMAL. AS RETURN FLOW DEVELOPS BY
MID WEEK WE WILL CONT TO MENTION THE CHANCES FOR MAINLY NOCTURNAL
SHOWERS AND THUNDERSTORMS TO END THE PERIOD.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1130 PM CDT THU JUL 24 2014
WINDS WILL CONTINUE TO GRADUALLY VEER TONIGHT THROUGH FRIDAY.
INITIALLY...WINDS WILL BE SOUTHEAST AT 12 TO 15 KNOTS...WITH
GUSTS UP TO 20 TO 25 KNOTS...BECOMING SOUTHWEST AND EVENTUALLY
NORTHWEST THROUGH THE PERIOD. A FEW SHOWERS AND THUNDERSTORMS WILL
ALSO BE POSSIBLE BETWEEN 6-8Z AT KOFK AND 7-09Z AT KLNK AND 8-10Z
AT KOMA. BUT ANY STORMS THAT DO MAKE THEIR WAY TO THOSE SITES ARE
EXPECTED TO BE FAIRLY SHORT LIVED.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM NOON TO 7 PM CDT FRIDAY FOR NEZ065>068-078-
088>093.
IA...HEAT ADVISORY FROM NOON TO 7 PM CDT FRIDAY FOR IAZ079-080-090-
091.
&&
$$
UPDATE...DEWALD
SHORT TERM...BOUSTEAD
LONG TERM...BOUSTEAD
AVIATION...DEWALD/GROSS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
334 AM CDT FRI JUL 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT FRI JUL 25 2014
THE LATEST SURFACE ANALYSIS PLACES A COLD FRONT FROM NEAR SHERWOOD
TO JUST EAST OF MINOT AND SOUTH TO NEAR LINTON. WEAK PRESSURE
FALLS CONTINUE AHEAD OF THE FRONT WITH AN AREA OF SHOWERS AND
ISOLATED THUNDERSTORMS MOSTLY OVER NORTH CENTRAL NORTH DAKOTA.
THE FOG/STRATUS LOOP INDICATES POCKETS OF LOWER CLOUDS BEHIND THE
FRONT BUT STEADILY MOVING EAST. THE HRRR CEILING FORECAST HAS A
GOOD HANDLE ON THE CURRENT SITUATION AND ALSO PROGRESSIVELY MOVES
THE BACK EDGE OF THE LOWER CLOUDS THROUGH THE JAMES RIVER VALLEY
BY 14Z. WATER VAPOR IMAGERY LOOP SHOWS AN UPPER LOW SPINNING OVER
SOUTHEASTERN ALBERTA WITH A DRIER WESTERLY FLOW INTO NORTH DAKOTA.
ALBEIT A FEW DISTURBANCES ARE EMBEDDED WITHIN THE FLOW BUT THESE
ARE NOT EXPECTED TO HAVE MUCH OF AN IMPACT DURING THE SHORT TERM
PERIOD. THUS EXPECT A MOSTLY SUNNY SKY WITH BREEZY CONDITIONS AS
WESTERLY WINDS WILL RANGE BETWEEN 15 AND 25 MPH. HIGHS TODAY WILL
RANGE FROM THE UPPER 70S NORTH TO LOWER 80S SOUTH. AN AREA OF
SHOWERS WILL DEVELOP OVER SOUTH DAKOTA TONIGHT AND REMAIN SOUTH OF
NORTH DAKOTA/SOUTH DAKOTA BORDER. LATE FRIDAY NIGHT THERE WILL
ALSO BE AN AREA OF SHOWERS SLIDING INTO SOUTHERN SASKATCHEWAN AND
MANITOBA...BUT THESE SHOWERS WILL REMAIN NORTH OF THE BORDER
THROUGH 12Z SATURDAY. THUS DRY CONDITIONS WILL PREVAIL THROUGH
FRIDAY NIGHT. OVERNIGHT LOWS FRIDAY NIGHT WILL BE IN THE 50S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 335 AM CDT FRI JUL 25 2014
THE MAIN FEATURE OF THIS FORECAST PERIOD WILL BE THE UPPER LEVEL
LOW FORECAST BY MODELS TO MOVE SOUTHEAST FROM SASK THROUGH
MINNESOTA EVENTUALLY MERGING WITH A LONGWAVE TROUGH OVER THE
EASTERN US. AS THIS PROCESS TAKES PLACE THE LOW WILL USHER IN
COOLER SURFACE TEMPERATURES AND MORE STABLE AIR. SCATTERED SHOWERS
AND POSSIBLE AN ISOLATED THUNDERSTORM ARE FORECAST FOR THE NORTH
AND EAST ON SATURDAY. SUNDAY THROUGH TUESDAY WILL BE DRY AND
COOLER WITH HIGHS AS COOL AS THE UPPER 60S ACROSS THE TURTLE
MOUNTAINS SUNDAY...AND 70S SOUTH AND WEST. EVENTUALLY A HIGH
AMPLITUDE FLOW DEVELOPS ACROSS NORTH AMERICA WITH A LONGWAVE
TROUGH OVER THE EASTERN US AND A RIDGE OVER THE WEST BY THE MIDDLE
OF NEXT WEEK. THIS LEAVES THE NORTHERN PLAINS IN A SLIGHTLY
ANTICYCLONIC NORTHWEST FLOW REGIME THAT SHOULD SUPPRESS MUCH OF
THE CONVECTION WEDNESDAY AND THURSDAY WITH JUST ISOLATED
THUNDERSTORMS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 335 AM CDT FRI JUL 25 2014
SATELLITE IMAGERY ALONG WITH SURFACE OBSERVATIONS INDICATE POCKETS
OF MVFR CIGS AT KMOT/KBIS/KJMS. THIS AREA OF LOW CIGS WILL MAKE
A STEADY PROGRESS EAST AND OUT OF KJMS TERMINAL BY 14Z FRIDAY.
OTHERWISE EXPECT VFR CIGS/VSBYS NEXT 24HR WITH WESTERLY WINDS
BETWEEN 15 AND 25 MPH THROUGH FRIDAY EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM...WAA
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1158 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 1158 PM CDT THU JUL 24 2014
LATEST LOCAL RADAR SHOWS ISOLATED SHOWERS AND THUNDERSTORMS ALONG
AND SOUTH OF I-94 WITH SCATTERED SHOWERS AND THUNDERSTORMS OCCURRING
NORTH. COLD FRONTAL SYSTEM ALONG A KENMARE TO GLEN ULLIN LINE IS
CONTINUING TO MOVE EAST. WILL MAINTAIN AN EASTWARD PROPAGATION OF
POPS/SKY GRIDS OVERNIGHT...DECREASING FROM WEST TO EAST. MINOR
ADJUSTMENTS TO CURRENT FORECAST.
UPDATE ISSUED AT 1018 PM CDT THU JUL 24 2014
SEVERE THUNDERSTORM WATCH 439 WAS ALLOWED TO EXPIRE AT 03 UTC AS
STORMS WILL BE PROPAGATING INTO A LESS FAVORABLE ENVIRONMENT ACROSS
CENTRAL NORTH DAKOTA. STRONG WINDS BEHIND THE LINE OF
THUNDERSTORMS ACROSS WESTERN NORTH DAKOTA HAVE STEADILY DECREASED
WITH SUNSET. WIND GUSTS ARE EXPECTED TO REMAIN BELOW 40 MPH...AND
THE HIGH WIND WARNING AND WIND ADVISORY THAT WERE IN EFFECT HAVE
BEEN CANCELLED.
UPDATE ISSUED AT 851 PM CDT THU JUL 24 2014
ISSUED A WIND ADVISORY FOR STRONG WINDS BEHIND THE OCCLUDING FRONT
ACROSS SOUTHWEST NORTH DAKOTA THROUGH 06 UTC.
UPDATE ISSUED AT 812 PM CDT THU JUL 24 2014
VERY STRONG WESTERLY WINDS WITH GUSTS IN EXCESS OF 50KTS HAVE BEEN
WIDESPREAD BEHIND THE LINE OF CONVECTION AND OCCLUDING FRONT
ACROSS NORTHEAST MONTANA. THIS IS EXPECTED TO CONTINUE INTO MUCH
OF WESTERN NORTH DAKOTA BEHIND THE LINE OF STORMS. THUS...A HIGH
WIND WARNING HAS BEEN ISSUED THROUGH 06 UTC FOR MUCH OF THE WEST.
UPDATE ISSUED AT 655 PM CDT THU JUL 24 2014
PER COORDINATION WITH SPC...SEVERE THUNDERSTORM WATCH 439 HAS BEEN
EXPANDED TO INCLUDE THE SOUTHWEST COUNTIES OF GOLDEN
VALLEY...BILLINGS...STARK...SLOPE...BOWMAN...HETTINGER AND ADAMS
COUNTIES UNTIL 03 UTC.
UPDATE ISSUED AT 540 PM CDT THU JUL 24 2014
THE 20 UTC AND INCOMING 21 UTC HRRR ITERATIONS HAVE A GOOD HANDLE
ON THE CURRENT CONVECTION ACROSS EASTERN MONTANA...AND WILL LEAN
HEAVILY ON THEIR SOLUTIONS FOR THE REMAINDER OF THE EVENING AND
OVERNIGHT. DID COORDINATE WITH SPC AT 2230 UTC REGARDING A
POTENTIAL EXPANSION OF SEVERE THUNDERSTORM WATCH 439 INTO
SOUTHWEST NORTH DAKOTA AS ROBUST CONVECTION ACROSS SOUTHEAST
MONTANA CONTINUES TO PROPAGATE NORTHEAST. WILL HOLD OFF FOR
NOW AS ALL REPORTS HAVE BEEN SUB-SEVERE. HOWEVER...SHOULD
CONVECTION STRENGTHEN AS IT APPROACHES BAKER...A WATCH EXPANSION
MAY BE NEEDED.
UPDATE ISSUED AT 410 PM CDT THU JUL 24 2014
SEVERE THUNDERSTORM WATCH 439 HAS BEEN ISSUED FOR NORTHWEST NORTH
DAKOTA THROUGH 03 UTC. PER COORDINATION WITH SPC...SEVERE
CONVECTION ACROSS NORTHWEST NORTH DAKOTA WILL LIKELY HOLD OFF
UNTIL AROUND 00-01 UTC AS STORMS ACROSS NORTH CENTRAL AND NORTHEAST
MONTANA COINCIDENT WITH THE BEST UPPER LEVEL FORCING PROPAGATE
EAST INTO NORTH DAKOTA...CLOSE TO THE 19 UTC HRRR SOLUTION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
SURFACE LOW OVER CENTRAL ALBERTA WITH A TROUGH EXTENDING SOUTHWARD
INTO CENTRAL/EASTERN MONTANA TO THE WYOMING/SOUTH DAKOTA BORDER. AT
UPPER LEVELS...STRONG UPPER LOW OVER CENTRAL ALBERTA WITH SOUTHWEST
FLOW ALOFT AND EMBEDDED SHORTWAVE ENERGY IMPULSES FORECAST TO MOVE
THROUGH THE UPPER LEVEL FLOW. MOST OF THE UPPER LEVEL ENERGY APPEARS
TO BE FOCUSED MORE NORTH OF THE CANADIAN BORDER...BUT PLENTY OF CAPE
AND SHEAR IN PLACE SOUTHWARD ALONG AND AHEAD OF THE SURFACE TROUGH.
MID-LEVEL CAP WAS BUILDING AHEAD OF THE TROUGH...BUT ISOLATED
ELEVATED THUNDERSTORMS HAD DEVELOPED OVER WESTERN NORTH DAKOTA AND
WERE MOVING EAST AT 30-35 MPH...LIKELY ASSOCIATED WITH WEAK UPPER
LEVEL IMPULSES IN THE UPPER FLOW - BUT NOT SURFACE-BASED.
THE MAIN ACTION IS EXPECTED LATER THIS AFTERNOON/EARLY EVENING AS
THE SURFACE TROUGH MOVES INTO WESTERN NORTH DAKOTA...AND INTO
CENTRAL NORTH DAKOTA THROUGH THE EVENING. THIS WILL BE SUPPORTED BY
MORE VIGOROUS UPPER LEVEL IMPULSES. SEVERE STORMS POSSIBLE...BUT
BEST CAPE IS ALONG AND AHEAD OF THE TROUGH...AND THE BEST SHEAR IS
RIGHT ALONG AND BEHIND THE TROUGH.
EXPECTING BEST CHANCES OF THUNDERSTORMS IN THE WEST LATE AFTERNOON
AND EARLY EVENING...AND BEST CHANCES IN THE CENTRAL FROM MID/LATE
EVENING INTO THE EARLY MORNING HOURS.
FRIDAY LOOKS DRY AND BREEZY WEST WINDS WITH HIGHS MAINLY IN THE
UPPER 70S TO MID 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
UPPER LEVEL LOW PROPAGATING EAST ACROSS SOUTH CENTRAL
CANADA...INTO FAR SOUTHEASTERN SASKATCHEWAN BY 12Z SAT...WILL
DRAG A SURFACE COLD FRONT THROUGH THE NORTHERN PLAINS SATURDAY
MORNING...THEN A SECONDARY COLD FRONT SATURDAY AFTERNOON/EVENING
AS THE LOW CONTINUES TOWARDS NORTHWESTERN MN. UPPER LEVEL FORCING
WITH THE LOW COUPLED WITH SFC CONVERGENCE ALONG THE FRONT WILL
BOTH COMBINE WITH LINGERING BOUNDARY LAYER MOISTURE TO RESULT IN
SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE NORTH SAT
MORNING...WITH COVERAGE OF PRECIPITATION SPREADING SOUTHEAST
DURING THE DAY.
SLIGHT CHANCES FOR PRECIPITATION OVER MY FAR EASTERN COUNTIES SAT
NIGHT/SUNDAY WITH THE UPPER LEVEL JET ACROSS THE MIDWEST.
STRONG SURFACE HIGH PRESSURE BUILDS INTO THE REGION SUNDAY/SUNDAY
NIGHT AHEAD OF AN UPPER LEVEL RIDGE OVER THE WESTERN CONUS...THEN
REMAINS QUASI-STATIONARY THROUGH THE DAY TUESDAY GIVING THE
NORTHERN PLAINS REGION A DRY WEATHER SPELL. BOTH THE 12Z GFS/ECMWF
INDICATE RIDGE RIDER S/WVS MOVING THROUGH THE DAKOTAS TUESDAY
NIGHT THROUGH THURSDAY. WITH THE SFC HIGH MOVING SOUTHEAST...WILL
SEE SPOTTY SHOWER/THUNDERSTORM CHANCES BEGINNING MID-WEEK.
TEMPERATURES WILL BE ON THE COOL SIDE FOR THE END OF JULY SAT-
MON...IN THE 70S...THEN WARM INTO THE 80S TUE-THURS WITH THE
BUILDING RIDGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1158 PM CDT THU JUL 24 2014
A COLD FRONT WILL MAINTAIN AN EASTWARD MOVEMENT ACROSS
KMOT/KBIS/KJMS THROUGH 12Z FRIDAY. ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS WILL CONTINUE OVERNIGHT BUT DECREASE FROM WEST
TO EAST. EXPECT A WIND SHIFT TO THE NORTHWEST BETWEEN 15 AND 25
MPH WHICH WILL CONTINUE INTO FRIDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...JV
LONG TERM...NH
AVIATION...KS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
303 AM CDT FRI JUL 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 303 AM CDT FRI JUL 25 2014
LATEST MOSAIC RADAR SHOWING A LINE OF SHOWERS AND THUNDERSTORMS
DEVELOPING FROM WEST CENTRAL MINNESOTA INTO CENTRAL IOWA EARLY
THIS MORNING. THE SHOWERS AND THUNDERSTORMS IS ON THE NOSE OF THE
LOW LEVEL JET/MOISTURE TRANSPORT AND CONVERGENCE IN THE 925-850MB
LAYER PER THE LATEST 25.03 RAP AND 25.00Z GFS/NAM.
THE 25.00Z NAM/GFS AND THE 25.03Z RAP INDICATE THE NOSE OF LOW LEVEL
JET/MOISTURE TRANSPORT AND CONVERGENCE WILL BE POINTED DIRECTLY INTO
MAINLY THE SOUTHERN FORECAST AREA THROUGH 18Z TODAY. HOWEVER...THE
MODELS SHOW THE CORFIDI VECTORS/UPWIND PROPAGATION VECTORS TO MOVE
THE SHOWERS AND THUNDERSTORMS SOUTH TO SOUTHEAST AND IMPACT MAINLY
THE SOUTHERN FORECAST AREA TODAY. THIS IS EVIDENT WITH MOVEMENT OF
THE THUNDERSTORMS EARLY THIS MORNING PER THE LATEST MOSAIC RADAR.
AT THIS TIME...SEVERE WEATHER THREAT LOOKS TO BE MINIMAL WITH THE
THUNDERSTORMS...AS THE LATEST 25.00Z NAM AND 25.03Z RAP SHOW 0-6KM
MOST UNSTABLE CAPE LESS THAN 1000 J/KG AND THE BETTER ELEVATED
INSTABILITY TO BE WEST OF THE DEVELOPING THUNDERSTORM
ACTIVITY/NOSE OF THE LOW LEVEL JET/MOISTURE CONVERGENCE. THE
MODELS SHOW PRECIPITABLE WATERS APPROACHING 1.5 TO 2 INCHES LATE
THIS MORNING. SOME OF THE THUNDERSTORMS COULD PRODUCE LOCAL HEAVY
RAINFALL.
THE LOW LEVEL JET/MOISTURE CONVERGENCE WEAKENS AND MOVES EAST OF
THE FORECAST AREA THIS AFTERNOON AND EVENING AND WILL ALLOW FOR
SKIES AND PRECIPITATION CHANCES TO DIMINISH WEST TO EAST ACROSS
THE FORECAST AREA.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 303 AM CDT FRI JUL 25 2014
NEXT CONCERN IS CLOSED UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN
AND ALBERTA SLOWLY MEANDERS OVER THE UPPER GREAT LAKES REGION
SATURDAY NIGHT INTO SUNDAY. THE 25.00Z GFS/NAM SHOW MUCH STRONGER
AND DEEPER QG FORCING IN ASSOCIATION WITH THE UPPER LEVEL LOW. BEST
FORCING INCREASES OVER THE NORTHERN PORTIONS OF FORECAST AREA LATE
SATURDAY NIGHT INTO SUNDAY...HENCE THE BETTER PRECIPITATION CHANCES.
THE NAM/GFS BUFKIT SOUNDINGS INDICATE WEAK ELEVATED CAPE MAINLY
ABOVE 800MB BY 18Z SUNDAY AND 0-6KM MOST UNSTABLE CAPE OF 500-1000
J/KG EAST OF THE MISSISSIPPI RIVER. WILL CONTINUE TO MENTION
ISOLATED THUNDERSTORMS SATURDAY NIGHT INTO SUNDAY.
SUNDAY NIGHT THROUGH THURSDAY...NORTHERLY FLOW DEVELOPS OVER THE
UPPER GREAT LAKES REGION PER LATEST 25.00Z GFS/ECMWF/GEM. MAIN
CONCERN IS TIMING OF THE WEAK SHORTWAVE TROUGHS EMBEDDED IN THE
NORTHERLY FLOW ALOFT AND PRODUCE SMALL PRECIPITATION CHANCES ACROSS
PARTS OF THE FORECAST AREA TUESDAY...WEDNESDAY NIGHT INTO
THURSDAY. TEMPERATURES MONDAY THROUGH THURSDAY WILL CONTINUE TO BE
UNSEASONABLY COOL ACROSS FORECAST AREA...AS THE 25.00Z GEFS
INDICATE 850MB TEMPERATURE ANOMALIES IN THE MINUS 0.5 TO MINUS 1.5
DEGREES CELSIUS RANGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1138 PM CDT THU JUL 24 2014
WARM AND HUMID AIR ABOVE THE GROUND IS RAPIDLY TRANSPORTING NORTH
ACROSS THE PLAINS...AND WILL SHORTLY TURN EASTWARD TOWARDS THE TAF
SITES. ANTICIPATING SHOWERS AND THUNDERSTORMS TO FORM ON THE NOSE
OF THIS AIRMASS COMING IN...MOVING INTO RST AROUND 10Z AND LSE
AROUND 11Z. THERE CONTINUES TO BE A SIGNAL FOR THE STORMS TO WANE
AS THEY APPROACH LSE...THUS ONLY A VCTS IS INCLUDED THERE...BUT DO
HAVE AN 11-13Z TEMPO GROUP FOR MVFR VISIBILITY REDUCTION IN
HEAVIER SHOWERS. AT RST...CONFIDENCE IS HIGHER FOR THUNDER WITH
MORE INSTABILITY AVAILABLE...THUS A 10-12Z TEMPO GROUP IS
INCLUDED FOR TSRA...AN IFR VISIBILITY AND MVFR CEILINGS. EXPECT
THE PRECIPITATION TO HEAD OFF TO THE EAST-SOUTHEAST DURING THE MID
MORNING HOURS...ALLOWING PRECIPITATION TO END BY 15Z AT RST AND
17Z AT LSE. VFR CONDITIONS SHOULD THEN BE THE RULE THROUGH THIS
EVENING AS WARM AIR ABOVE THE GROUND HELPS PREVENT STORMS FROM
FIRING.
IN THE WIND DEPARTMENT...A CORRIDOR OF 35-40 KT SOUTHWEST WINDS
AT 1500 FT AGL COMING ACROSS IN THE MID MORNING HOURS COULD MIX
DOWN TO THE SURFACE. THEREFORE...HAVE GUSTS AROUND 20 KT MENTIONED
IN THE TAFS. WILL HAVE TO MONITOR THE WINDS CLOSELY IN THE WAKE OF
THE SHOWERS/STORMS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1138 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 849 PM CDT THU JUL 24 2014
HAVE DRIED OUT THE FORECAST FOR THE REST OF THE EVENING WITH
SUBSIDENCE IN THE WAKE OF THE AFTERNOON/EARLY EVENING COMPLEX IN
CONTROL. HOWEVER...SOMETHING TO MONITOR IS A SHOWER DEVELOPING
WEST OF ALEXANDRIA MN. ATTENTION OTHERWISE FOCUSES TO A CLUSTER
OF STORMS OVER NORTHWEST SOUTH DAKOTA. 24.23Z HRRR AND 25.00Z RAP
TAKE THIS CLUSTER ACROSS NORTHERN SOUTH DAKOTA...BASICALLY
CROSSING THE UPPER RIDGE AXIS THERE. AS THE COMPLEX APPROACHES
NORTHEAST SOUTH DAKOTA...A LOW LEVEL JET INCREASE IS EXPECTED
ALONG WITH VEERING TO POINT TOWARDS THE FORECAST AREA. IN
FACT...THIS INCREASE AND TURNING IS ALREADY TAKING PLACE AT FSD
WHERE SOUTH-SOUTHWEST 45 KT 850MB WINDS EXIST ON THEIR RADAR. A
BAND OF SHOWERS AND STORMS IS LIKELY TO INITIATE ON THE NOSE OF
THE LOW LEVEL JET...EVENTUALLY PROGRESSING INTO WESTERN PORTIONS
OF THE FORECAST AREA BETWEEN 09-10Z AND PERHAPS TO THE MS RIVER BY
12Z.
HAVE UPDATED PRECIPITATION CHANCES AND QPF TO REFLECT THE
AFOREMENTIONED SCENARIO. SOME HINTS IN THE HRRR THAT THE STORMS
WITHIN THE SHOWERS MAY FALL APART AROUND 12Z. IF THIS TREND
CONTINUES...MAY HAVE TO PULL OR AT LEAST REDUCE THUNDER CHANCES.
UPDATE ISSUED AT 550 PM CDT THU JUL 24 2014
HAVING SOME SERIOUS CONCERNS WITH THE PRECIPITATION CHANCES THIS
EVENING...AND POSSIBLY OVERNIGHT TOO.
CURRENTLY...WATER VAPOR LOOP AND RADAR IMAGERY SHOWED A COMPLEX
OF SHOWERS AND STORMS DROPPING SOUTH...NOW INTO NORTHWEST AND
NORTH CENTRAL IOWA. THE EASTWARD PROGRESSION OF THE PRECIPITATION
TOWARDS THE FORECAST AREA HAS COME TO A HALT DUE TO THE COMPLEX
MOTION...ALONG WITH PLENTIFUL DRY AIR OVER THE FORECAST AREA.
2030Z TAMDAR SOUNDING FROM MSP SHOWED 10C OR HIGHER DEWPOINT
DEPRESSIONS FROM 770-600MB AND A DEEP INVERTED-V AT 800MB.
SUBSIDENCE IN THE WAKE OF THIS COMPLEX SHOWING UP AS A SIGNIFICANT
AREA OF CLEARING OVER WEST-CENTRAL MN...DRYING IN THE SAME
LOCATION ON WATER VAPOR...AND SURFACE PRESSURE FALLS UP TO 2
MB/HR.
ITS TOUGH FINDING A MODEL WITH A GREAT HANDLE ON THIS CURRENT
COMPLEX. THE 24.21Z RAP...24.19Z HRRR AND 24.18Z GFS SEEM TO BE
THE BEST AND ALL THREE SUGGEST THAT THE EVENING MAY NOW END UP
DRY ACROSS THE FORECAST AREA. THIS SEEMS REASONABLE AS THE
SUBSIDENCE COMES INTO THE FORECAST AREA IN THE WAKE OF THE
COMPLEX. IN FACT...GIVEN THE CLEARING UPSTREAM...ITS POSSIBLE
THAT CLEARING COMES INTO THE AREA. NEXT CONCERN THEN TURNS TO THE
OVERNIGHT CONVECTION POSSIBILITIES. WITH SUBSIDENCE AND COLD POOL
IN PLACE OVER MN AND NORTH CENTRAL IOWA...WHEN THE LOW LEVEL JET
INCREASES TONIGHT...THE CONVECTION MAY END FIRING MORE ALONG THE
WESTERN MN/IOWA BORDER. THE AFOREMENTIONED MODELS ALONG WITH THE
24.12Z ECMWF AND EVEN TO SOME DEGREE THE 24.18Z NAM ALL SHOW THAT
IDEA. IF THE CONVECTION DEVELOPS AN MCV...THEN THE CONVECTION WILL
DROP SOUTHEAST AND STAY MOSTLY WEST OF THE FORECAST AREA. THIS IS
WHAT THE 24.18Z NAM AND 24.12Z HIRES-ARW SUGGESTED. HOWEVER...IF
NO MCV FORMS...A FRONTOGENETICAL BAND OF SHOWERS AND EMBEDDED
STORMS WOULD MOVE WEST TO EAST INTO THE FORECAST AREA AFTER
07Z...PERHAPS REACHING THE MS RIVER BY 12Z.
FOR NOW...HAVE TRENDED PRECIPITATION CHANCES DOWN SOME FOR THE
EVENING AND FURTHER DECREASES ARE POSSIBLE. HAVE NOT ADJUSTED THE
OVERNIGHT YET...BUT COULD SEE A NEED TO DECREASE PRECIPITATION
CHANCES ALONG/EAST OF THE MS RIVER. NEEDLESS TO SAY THE
PRECIPITATION CHANCES FOR TONIGHT IS A FLUID SITUATION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 320 PM CDT THU JUL 24 2014
MAIN FORECAST PROBLEM WAS THE STORMS/WEATHER MOVING IN OVERNIGHT
INTO FRIDAY MORNING.
A TALE OF TWO AIR MASSES ACROSS THE REGION THIS MORNING IN THE
OBSERVATIONAL DATA. 24.12Z RAOBS SHOWING STEEP 700-500MB LAPSE RATES
OVER THE WESTERN DAKOTAS /9C PER KM/ AND MID-LEVEL SATURATION
OCCURRING ON THE EASTERN EDGE OF THE DEEPER N-S MOIST PLUME IN
PLACE. PRECIPITABLE WATER /PWAT/ VALUES AT KBIS/KABR BOTH ARE BOTH
OVER 125 PERCENT THIS MORNING. KBIS AND KABR SOUNDINGS BOTH SHOW
SATURATION AROUND 700MB WITH 500-1000J/KG OF ELEVATED CAPE ABOVE
700MB. EAST OF THE MOIST PLUME...STABILITY REIGNS WITH 5-6C/KM
500-700MB LAPSE RATES AND BELOW NORMAL PWAT VALUES /65 PERCENT/ AT
KMPX. THIS GRADIENT AND MOISTURE TRANSPORT CONVERGENCE OVER THE
DAKOTAS/MN BORDER AT 16Z MATCHED WELL WITH THE MORNING STORMS AND
WEATHER IN THE DAKOTAS. THIS ALL ENHANCED BY A VERY VISIBLE
SHORTWAVE TROUGH SEWRD OF KBIS AND ANOTHER NORTH OF THE MT/ND/SRN
CANADA BORDER.
AS THE LARGE SCALE SHIFTS OVER NORTH AMERICA AND THE LONG WAVE
TROUGH OVER THE EAST WEAKENS...FLAT RIDGING BUILDS ACROSS THE
NORTHERN STATES /THROUGH SATURDAY/. THIS WILL PROMOTE WARMING AND
RICHER MOISTURE TO MOVE INTO THE REGION FOR A PERIOD...BEFORE
REAMPLIFICATION OF THE TROUGH OVER THE ERN CONUS OCCURS /SUNDAY/.
BEGINNING OVERNIGHT...THE DAKOTAS AIR MASS WILL ADVECT EASTWARD
AND INTO THE AREA. THIS AIRMASS IS CHARACTERIZED BY HIGHER
MOISTURE BUT ALSO VERY WARM TEMPERATURES ALOFT AS AN ELEVATED
MIXED LAYER MOVES IN. WHILE THIS HAS STEEP MID-LEVEL LAPSE
RATES...THE 700MB TEMPERATURES WARM FROM 8C TO 12-14C
FRIDAY...PROVIDING A STOUT CAPPING INVERSION TO SURFACE BASED
CONVECTION BY AFTERNOON. THIS TRANSLATES TO A 600 J/KG SBCIN. THIS
CAP BUILDING HAS VERY GOOD CONSENSUS AMOUNT THE DETERMINISTIC
MODELS...AND HAVE LOWERED RAIN CHANCES FRIDAY AFTERNOON
ACCORDINGLY.
PRIOR TO THE ELEVATED MIXED LAYER BUILDING IN FRIDAY...LOW-LEVEL
WARM ADVECTION AND MOISTURE TRANSPORT INCREASES WITH HEIGHT FALLS
AND INCREASED SOUTHERLY FLOW OVERNIGHT. THIS EVENING THERE IS SOME
SIGNAL FOR MID-LEVEL MOISTURE TRANSPORT CONVERGENCE /700MB/ TO
MOVE IN FROM THE WEST DURING THE EVENING AND LAPSE RATES WOULD SAY
SOME MID-LEVEL TOWERING CU COULD DEVELOP SOME SHOWERS
/100-300J/KG MUCAPE/. HAVE BEEN MONITORING THE CONVECTION ENTERING
WESTERN MN AND WHILE MUCAPE VALUES HAVE INCREASED A FEW HUNDRED
FROM 15-18Z...MUCH OF MN IS STILL QUITE STABLE. HOWEVER...THE
NORTHERN SIDE SEEMS TO BE TIED TO THE 700 MB TRANSPORT CONVERGENCE
AND SHORTWAVE TROUGH APPROACHING FARGO. WOULD EXPECT ECHO TO
WEAKEN AS IT MOVES TOWARD I-35...ALTHOUGH THERE IS WEAK
FORCING...THE AIR MASS IS VERY DRY. WILL HAVE TO MONITOR...BUT
TIMING LOOKS TO FIT THE EVENING INCREASE OF PRECIPITATION CHANCES.
BY MIDNIGHT...AS THE RIDGE BUILDS EAST...MOISTURE TRANSPORT AND A 40-
50KT LOW-LEVEL JET AT 850 MB FEED THE EASTERN EDGE OF THE MOISTURE
PLUME UP THE . BY 09Z...A MESOSCALE CONVECTIVE SYSTEM IS EXPECTED
TO ENTER THE WESTERN FORECAST AREA ON VERY STRONG MOISTURE
TRANSPORT CONVERGENCE AT 850 MB /50KTS DECREASING TO 15 KTS...KDSM
TO KLSE/. THIS SIGNAL IS VERY CONSISTENT AMONG THE 24.12Z MODELS
AND LATEST RAP GUIDANCE. CORFIDI VECTORS SUGGEST SOUTHEAST
MOVEMENT TO THE STRONGER CONVECTIVE ELEMENTS...AND THIS COULD POSE
SOME PROBLEMS WITH THE COMPLEX MISSING TO THE SOUTHWEST. WITH THE
MOISTURE TRANSPORT CONVERGENCE INTO THE HEART OF THE FORECAST
AREA...WOULD THINK A MISS IS PROBABLY UNLIKELY. THIS WOULD FAVOR
THE AREAS SOUTHWEST OF I-94...ESPECIALLY INTO NORTHEAST IOWA AND
LITTLE CHANGE TO THE RAIN CHANCES WERE MADE.
PRECIPITABLE WATER VALUES INCREASE RAPIDLY OVERNIGHT WITH OVER
1.75 INCHES IN THE AREA BY MORNING AND WARM CLOUD DEPTHS OF 4 KM.
THUS HEAVY RAINFALL RATES WILL OCCUR IN THE SYSTEM...BUT MANY
AREAS CAN USE THE RAINS. SOME BRIEF CITY FLOODING IS POSSIBLE.
ISOLATED HAIL AND GUSTY WINDS HAVE BEEN ADDED TO AREAS WEST OF THE
MISS RIVER IN THE HAZ WEATHER OUTLOOK DUE TO THE MAGNITUDE OF
CONVERGENCE/FORCING AND ABOUT 1500 J/KG OF MUCAPE. SPC HAS ALSO
SHIFTED THEIR DAY 1 CONVECTIVE OUTLOOK TO NEAR OUR WESTERN
FORECAST AREA EDGE...WHICH IS APPROPRIATE. CAPPING SHOULD THEN
BUILD IN AND THE SYSTEM MOVES EAST/SOUTHEAST IN THE AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 320 PM CDT THU JUL 24 2014
FRIDAY NIGHT POSES AN INTERESTING PROBLEM IN SRN WISCONSIN AS THE
CAP IS STILL FULLY IN PLACE WITH NO SURFACE BASED CONVECTION
ALLOWED PER ALL GUIDANCE /600 SBCIN AND 700MB TEMPS NEAR 14C/.
YET A HANDFUL OF DETERMINISTIC MODELS CONTINUE A SIGNAL OF QPF
ACROSS SRN WISCONSIN IN THE EVENING. HAVE KEPT A SMALL RAIN CHANCE
THERE AS IT WOULD BE SOME MID-LEVEL INSTABILITY THAT WOULD HAVE TO
BE TAPPED NORTH OF THE SURFACE LOW SHIFTING THROUGH ERN IA. THE
24.12Z NAM DOES HAVE SOME 900-800MB FRONOTGENESIS WORKING WITHIN
THE CAPPED AREA...AND POSSIBLY SOME ISENTROPIC LIFT GENERATES
STABLE SHOWERS. PREFER THE 24.12Z NAM WITH RAINFALL SOUTH OF THE
FORECAST AREA...BUT HAVE KEPT A SLIGHT CHANCE OF RAIN TO COVER
THIS SITUATION FRIDAY EVENING.
A DRYING TREND THEN IN NORTHWEST FLOW AFTER MIDNIGHT...THROUGH
SATURDAY PROVIDES A VERY NICE DRY DAY. THE HIGH PRECIPITABLE WATER
AIRMASS SHOULD PUSH SOUTH TO NEAR I-80 CORRIDOR.
STRONG QG CONVERGENCE FORCING MOVES IN SUNDAY WITH THE STRONG
TROUGH MOVING THROUGH MN/WI AS THE LONG WAVE AMPLIFIES AGAIN OVER
THE EASTERN CONUS. FORCING COMES IN LATER SATURDAY NIGHT AND IS
STRONGEST SUNDAY WITH SOME INSTABILITY. HAVE INCREASED RAIN
CHANCES FOR SUNDAY. RAIN CHANCES MAY NEED TO BE PULLED FURTHER
SOUTHWEST AS WELL DEPENDING ON THE WAVE TRACK. A CLOUDY BREEZY
SHOWERY DAY FOR MOST AREAS IT SEEMS.
MONDAY THROUGH THURSDAY HAVE BELOW NORMAL TEMPERATURES AND MOSTLY
DRY WEATHER UNDER THE INFLUENCE OF THE LONGWAVE TROUGH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1138 PM CDT THU JUL 24 2014
WARM AND HUMID AIR ABOVE THE GROUND IS RAPIDLY TRANSPORTING NORTH
ACROSS THE PLAINS...AND WILL SHORTLY TURN EASTWARD TOWARDS THE TAF
SITES. ANTICIPATING SHOWERS AND THUNDERSTORMS TO FORM ON THE NOSE
OF THIS AIRMASS COMING IN...MOVING INTO RST AROUND 10Z AND LSE
AROUND 11Z. THERE CONTINUES TO BE A SIGNAL FOR THE STORMS TO WANE
AS THEY APPROACH LSE...THUS ONLY A VCTS IS INCLUDED THERE...BUT DO
HAVE AN 11-13Z TEMPO GROUP FOR MVFR VISIBILITY REDUCTION IN
HEAVIER SHOWERS. AT RST...CONFIDENCE IS HIGHER FOR THUNDER WITH
MORE INSTABILITY AVAILABLE...THUS A 10-12Z TEMPO GROUP IS
INCLUDED FOR TSRA...AN IFR VISIBILITY AND MVFR CEILINGS. EXPECT
THE PRECIPITATION TO HEAD OFF TO THE EAST-SOUTHEAST DURING THE MID
MORNING HOURS...ALLOWING PRECIPITATION TO END BY 15Z AT RST AND
17Z AT LSE. VFR CONDITIONS SHOULD THEN BE THE RULE THROUGH THIS
EVENING AS WARM AIR ABOVE THE GROUND HELPS PREVENT STORMS FROM
FIRING.
IN THE WIND DEPARTMENT...A CORRIDOR OF 35-40 KT SOUTHWEST WINDS
AT 1500 FT AGL COMING ACROSS IN THE MID MORNING HOURS COULD MIX
DOWN TO THE SURFACE. THEREFORE...HAVE GUSTS AROUND 20 KT MENTIONED
IN THE TAFS. WILL HAVE TO MONITOR THE WINDS CLOSELY IN THE WAKE OF
THE SHOWERS/STORMS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS TUCSON AZ
300 AM MST FRI JUL 25 2014
.SYNOPSIS...SHOWERS AND THUNDERSTORMS WILL INCREASE ACROSS THE AREA
TODAY AND CONTINUING INTO THIS WEEKEND WITH THE GREATEST COVERAGE
EXPECTED SATURDAY AFTERNOON AND SATURDAY NIGHT. TEMPERATURES WILL
ALSO FALL BACK CLOSER TO AVERAGE OVER THE NEXT FEW DAYS.
&&
.DISCUSSION...THE ATMOSPHERE HAS MOISTENED UP CONSIDERABLY ACROSS
SOUTHEAST ARIZONA /ESPECIALLY FROM TUCSON WESTWARD/AFTER A GULF
SURGE AIDED BY OUTFLOW FROM THUNDERSTORMS TO OUR SOUTHWEST MOVED
THROUGH THE AREA LAST NIGHT. SURFACE DEWPOINTS ARE GENERALLY IN THE
UPPER 50S TO LOWER 60S ACROSS MOST OF THE AREA WITH THE EXCEPTION OF
GRAHAM AND GREENLEE COUNTY WHERE SURFACE DEWPOINTS ARE MOSTLY IN THE
40S. THIS CORRESPONDS TO PWAT VALUES RANGING FROM UNDER AN INCH IN
GRAHAM AND GREENLEE COUNTY TO 1.2 TO 1.6 INCHES FROM TUCSON
WESTWARD.
THE HIGH PRESSURE ALOFT IS NOW IN A FAVORABLE POSITION ACROSS NEW
MEXICO. GIVEN THE INCREASE IN MOISTURE...AMPLE SUNSHINE TO START THE
DAY AND FAVORABLE EAST TO SOUTHEAST STEERING FLOW...IT IS SHAPING UP
TO BE A FAIRLY ACTIVE DAY ESPECIALLY FROM TUCSON WESTWARD WHERE THE
MOISTURE IS GREATEST. CONFIDENCE IS INCREASING ON SHOWERS AND
THUNDERSTORMS PRODUCING STRONG OUTFLOW WINDS AS REFLECTED IN THE
LATEST HRRR ALONG WITH OUR LOCAL WRF. A BLOWING DUST ADVISORY WILL
BE ISSUED ACROSS PORTIONS OF EASTERN PIMA COUNTY /JUST NORTHWEST OF
TUCSON/ ALONG WITH CENTRAL AND WESTERN PIMA COUNTY AND SOUTH-CENTRAL
PINAL COUNTY TO COVER THE DUST THREAT. STORM MOTION AROUND 10 TO 15
MPH SHOULD BE FAST ENOUGH TO PRECLUDE A WIDESPREAD FLOOD THREAT BUT
LOCALLY HEAVY RAINFALL IS POSSIBLE.
THE ACTIVE PATTERN IS EXPECTED TO CONTINUE ON SATURDAY AS THE
MOISTURE REMAINS ACROSS SOUTHEAST ARIZONA WITH AN INVERTED TROUGH
EXPECTED TO MOVE INTO THE AREA FROM THE EAST SATURDAY EVENING. THIS
SHOULD RESULT IN ADDITIONAL LIFT FOR MORE WIDESPREAD SHOWER AND
THUNDERSTORM ACTIVITY...FOCUSED LATE SATURDAY AFTERNOON INTO
SATURDAY NIGHT. GIVEN THE UPPER LEVEL SUPPORT...THE STORMS MAY VERY
LOSE DIURNAL TRENDS AND CONTINUE IN SOME FASHION OVERNIGHT SATURDAY
NIGHT. IN ADDITION...WE ARE ALSO CONCERNED ABOUT BLOWING DUST ONCE
AGAIN SATURDAY AFTERNOON AND EVENING BUT WE HAVE PLENTY OF TIME TO
HONE IN ON THOSE POSSIBLE DETAILS AS IT GETS CLOSER.
THEREAFTER...SUNDAY MAY VERY WELL BE MORE OF A DOWN DAY WITH
CONSIDERABLE CLOUDS AND A WORKED OVER ATMOSPHERE GIVEN THE EXPECTED
STORM COVERAGE SATURDAY/SATURDAY NIGHT. THE MOISTURE PLUME WILL
REMAIN OVER ARIZONA MONDAY BUT THINGS GET A BIT MORE UNCERTAIN BY
THE MIDDLE OF NEXT WEEK AS THE UPPER HIGH SHIFTS SOUTH AND WEST
CLOSER TO SOUTHEAST ARIZONA. IN FACT...THE 00Z ECMWF SHIFTS THE HIGH
CENTER A BIT SOUTH AND WEST OF US BY WEDNESDAY WITH CONSIDERABLE
DRYING. IN CONTRAST...THE 00Z GFS AND CANADIAN KEEP THE HIGH NEAR
THE AZ/NM BORDER WITH SOMEWHAT BETTER MOISTURE IN THE AREA. MADE
ONLY MINOR TWEAKS TO THE FORECAST FOR NEXT WEEK WITH GENERALLY A
LOWER GRADE MONSOON EXPECTED STARTING TUESDAY. WITH THE HIGH BEING
CLOSER TO THE AREA...TEMPERATURES WILL ALSO BE ON THE INCREASE NEXT
WEEK...RISING TO ABOUT 5 TO 7 DEGREES ABOVE NORMAL VALUES FOR LATE
JULY.
&&
.AVIATION...VALID THRU 26/12Z.
HIGH PRESSURE CENTERED OVER WEST TEXAS WILL RESULT IN A MOIST ELY/
SELY MID-LEVEL FLOW REGIME INTO SATURDAY MORNING. THE COMBINATION OF
STRONG DAYTIME HEATING COMBINED WITH ADEQUATE MOISTURE WILL RESULT
IN -TSRA/-SHRA MAINLY NEAR THE MOUNTAINS BY 25/19Z FROM KTUS
VICINITY EWD/SWD. SCATTERED TSRA/SHRA IS THEN FORECAST TO MOVE TO
THE WEST AND NORTHWEST THIS AFTERNOON AND THIS EVENING. AREAS OF
BLDU WITH VSBYS BELOW 1/2SM MAY OCCUR NW OF KTUS INTO PINAL COUNTY
SE OF KPHX THIS AFTERNOON AND THIS EVENING. ELSEWHERE...MVFR VSBYS
WITH WIND GUSTS GENERALLY OF 40-45 KTS WILL OCCUR WITH THE STRONGER
TSRA. THERE WILL BE ENOUGH MOISTURE TO MAINTAIN ISOLATED -TSRA/-SHRA
LATE TONIGHT AND EARLY SATURDAY MORNING. OTHERWISE...CLOUD DECKS
THIS AFTERNOON INTO SATURDAY MORNING WILL GENERALLY BE AT 10-15K FT
AGL. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...AMPLE MOISTURE WILL TRANSLATE INTO SCATTERED
THUNDERSTORMS THIS AFTERNOON AND THIS EVENING. EXPECT SCATTERED TO
NUMEROUS THUNDERSTORMS SATURDAY AFTERNOON AND SATURDAY EVENING AS
MOISTURE INCREASES ACROSS THE AREA. A GRADUAL DECREASE IN
THUNDERSTORM ACTIVITY IS THEN FORECAST TO OCCUR STARTING SUNDAY AND
CONTINUING INTO THE MIDDLE OF NEXT WEEK. HOWEVER...MOISTURE WILL
REMAIN SUFFICIENT FOR ISOLATED TO SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
BLOWING DUST ADVISORY FROM 2 PM THIS AFTERNOON TO 9 PM THIS EVENING
FOR AZZ501-502-504-505.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS MIAMI FL
1042 AM EDT FRI JUL 25 2014
.UPDATE...
DO NOT PLAN TO MAKE ANY MAJOR CHANGES TO THE CURRENT FORECAST. A
WEAK UPPER LEVEL LOW PRESSURE AREA OVER THE FLORIDA PANHANDLE THIS
MORNING HAS BECOME PINCHED OFF BETWEEN TWO STRONG RIDGES, ONE TO
OUR EAST AND EXTENDING ACROSS SOUTH FLORIDA WITH THE OTHER
CENTERED OVER THE SOUTHERN PLAINS. THIS HAS LOWERED THE 500MB
TEMPERATURES FROM A BALMY -4.7C YESTERDAY MORNING TO -7C AT 12Z
THIS MORNING FROM THE MFL SOUNDING. DUE TO THIS COOLING ALOFT, THE
MID LEVEL LAPSE RATES HAVE BECOME MORE CONDUCIVE TO CONVECTIVE
DEVELOPMENT AT 6.2C/KG. THIS FIGURE IS NOT HIGH, BUT SIGNIFICANTLY
MORE UNSTABLE THAN 24 HOURS AGO. THAT BEING SAID, WITH PLENTY OF
DIURNAL HEATING TAKING PLACE THIS MORNING (ALREADY 90 ACROSS THE
INTERIOR) THIS WILL SET THE STAGE FOR A MORE ACTIVE THUNDERSTORM
DAY. THE STEERING FLOW IS FROM NORTH TO SOUTH SO THE MAIN ACTION
IS EXPECTED TO BE OVER THE INTERIOR AREAS AND THE HRRR SEEMS TO
HAVE A GOOD HANDLE ON THIS THINKING. HOWEVER, WITH THE FLOW NEARLY
PARALLEL TO BOTH COASTS THERE COULD BE A FEW STORMS JUST INLAND
FROM THE COASTS UNTIL THE SEA BREEZES CAN STEER THE CELLS MORE
TO THE INTERIOR AREAS.
KOB
&&
.PREV DISCUSSION... /ISSUED 740 AM EDT FRI JUL 25 2014/
AVIATION...
MAINLY VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. SHOWERS
AND STORMS WERE MOVING NORTH OVER THE GULF WATERS TO THE SOUTH OF
KAPF...BUT A FEW SHOWERS OR STORMS COULD GET NEAR THE TAF SITE
THROUGH EARLY AFTERNOON. SLIGHTLY DRIER AIR HAS MOVED INTO THE
EAST COAST TAF SITES OVERNIGHT. GUIDANCE IS INDICATING THAT
SHOWERS AND STORMS WILL FORM WELL AWAY FROM THE EAST COAST TAF
SITES THIS AFTERNOON DUE TO THE DRIER AIR...SO KEPT VCTS OUT OF
THE EAST COAST TAF SITES FOR NOW. LIGHT WINDS THIS MORNING WILL
SHIFT ONSHORE AND INCREASE TO AROUND 10 KNOTS AS SEA BREEZE
BOUNDARIES MOVE INLAND. LIGHT WINDS ARE EXPECTED AGAIN OVERNIGHT.
PREV DISCUSSION... /ISSUED 325 AM EDT FRI JUL 25 2014/
DISCUSSION...
RECENT SATELLITE IMAGERY INDICATES SOME RELATIVELY DRIER AIR
ACROSS THE NORTHWEST BAHAMAS WITH DEEP LAYERED MOISTURE AND
ASSOCIATED CLOUDINESS ACROSS THE FLORIDA STRAITS AND THE LOCAL
GULF WATERS. THE LATEST GUIDANCE INDICATES THAT THE DRIER AIR WILL
LIKELY REMAIN TO THE EAST OF THE REGION WHILE SOUTHERLY FLOW
ACROSS THE FLORIDA STRAITS TODAY WILL CONTINUE TO ADVECT DEEPER
MOISTURE INTO THE REGION THROUGH THE DAY. THE FORECAST PWAT FOR
THE MIAMI SOUNDING LOCATION AROUND 18Z IS ABOUT 1.7 INCHES.
ALTHOUGH THERE WILL BE WEAK SUBSIDENCE AT THE UPPER
LEVELS...AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS ARE STILL
EXPECTED ACROSS THE PENINSULA TODAY WITH THE GREATEST COVERAGE
EXPECTED IN THE WESTERN INTERIOR REGIONS WITH MOSTLY ISOLATED
ACTIVITY ACROSS THE LOCAL WATERS.
THERE IS LIKELY SOME SAHARAN DUST TO THE EAST OF THE BAHAMAS...BUT
LATEST GUIDANCE INDICATES IT IS DIFFUSE AND WILL NOT LIKELY HAVE
MUCH IMPACT ON SOUTH FLORIDA ALTHOUGH THE SKIES COULD BE MORE HAZY
THAN USUAL.
THE AFOREMENTIONED DEEPER MOISTURE EXPECTED ACROSS THE REGION
TODAY IS FORECAST TO LINGER ACROSS THE REGION ON SATURDAY...WITH
FORECAST PWAT VALUES STILL LINGERING AROUND 1.7 INCHES. LATEST
GUIDANCE INDICATES SOME DRIER AIR MOVING INTO THE FLORIDA STRAITS
BUT IS NOT FORECAST TO MOVE FAR ENOUGH NORTH TO HAMPER CONVECTION
ACROSS THE PENINSULA ON SATURDAY AFTERNOON WITH SHOWERS AND
THUNDERSTORMS EXPECTED WITH THE GREATEST COVERAGE EXPECTED IN THE
WESTERN INTERIOR.
BY SUNDAY THE DRIER AIR IN THE STRAITS IS FORECAST TO MOVE NORTH
WITH PWATS POSSIBLY DROPPING TO AROUND 1.2 INCHES WITH COVERAGE OF
SHOWERS ACROSS THE PENINSULA GREATLY REDUCED WITH MAINLY SCATTERED
ACTIVITY AROUND THE LAKE REGION FORECAST.
THE LATEST GLOBAL MODEL EXTENDED GUIDANCE INDICATES A COLD FRONT
COULD ENTER THE SOUTHEASTERN STATES ON MONDAY AND COULD HAVE
SUFFICIENT ENERGY TO MOVE INTO NORTH TO CENTRAL FLORIDA ON
WEDNESDAY. WILL HAVE TO SEE WHAT THE FUTURE GUIDANCE WILL DO WITH
THIS SCENARIO TO SAY WHAT...IF ANY...IMPACTS MIGHT BE EXPECTED IN
SOUTH FLORIDA LATER NEXT WEEK.
MARINE...
GENERALLY SOUTHEASTERLY WINDS 10 KNOTS OR LESS ARE FORECAST TO
PREVAIL ACROSS THE REGIONAL WATERS TODAY AND THROUGH THE UPCOMING
WEEKEND...WITH REGIONAL SEAS 2 FEET OR LESS THROUGH THIS PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 91 78 89 78 / 30 20 40 20
FORT LAUDERDALE 90 81 90 81 / 20 20 30 20
MIAMI 91 79 91 80 / 30 20 30 20
NAPLES 92 77 90 76 / 30 20 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$CV
Area Forecast Discussion
National Weather Service Lincoln IL
1043 AM CDT Fri Jul 25 2014
.DISCUSSION...
ISSUED 1043 AM CDT Fri Jul 25 2014
Already did a major update to the forecast today for more cloud
cover along with much higher chances of showers along with
isolated thunderstorms for areas west of I-57 into early
afternoon. Continued a chance of showers and thunderstorms during
mid/late afternoon over central IL with just slight chances in
southeast IL while far southeast IL near Lawrence county to likely
stay dry today. Trimmed highs down a bit into upper 70s to around
80 degrees due to more showers and clouds over central IL.
MCS over eastern IA, northeast MO and nw half of IL has held
together longer than earlier expected as it tracked se to along
I-72 by late morning. Just isolated thunderstorms west of I-55
while more numerous thunderstorms and heavier rains have been on
western edge of MCS over ne MO and se IA. SPC has 5% risk of large
hail and damaging wind gusts nw of a Shelbville to Tuscola line
today so severe threat quite low today.
12Z ILX sounding showing a lot of dry air below 650 mb so this
should weaken the convection into this afternoon as it continues
moving se toward I-70. Think HRRR model is holding onto convection
too long as it moves it into southeast IL by mid afternoon. NAM
and RUC/RAP model on the other hand appears too quick diminishing
convection during early afternoon. Will blend between the wetter
HRRR and drier NAM/RUC models for the afternoon forecast.
Southerly winds increasing to 10-15 mph this afternoon between
1021 mb high pressure over WV and ridging into the ohio river
valley and 1006 mb low pressure in eastern SD/NE to bring in a bit
more humid air into central IL this afternoon. Dewpoints currently
in the upper 50s to around 60F rising to between 60-65F during the
afternoon and highest west of the IL river.
07
&&
.AVIATION...
ISSUED 657 AM CDT Fri Jul 25 2014
Mainly VFR conditions are expected over central and southeast
Illinois today and tonight. A weakening thunderstorm system will
move across central AZ today bringing increasing low and mid-
level cloud cover along with scattered showers and isolated
thunderstorms. The best chances for showers and thunderstorms
until 18Z will be from KSPI-KBMI northwestward. Have placed
temporary MVFR conditions in the KPIA TAF, but left out of other
area TAFS due to low probabilities and coverage of MVFR
cigs/vsbys. Another disturbance tracking into the area this
evening is expected to bring more showers and thunderstorms
overnight. Winds generally southerly around 10 KTS from 15Z through
12Z Saturday.
Onton
&&
.PREV DISCUSSION...
ISSUED 247 AM CDT Fri Jul 25 2014
Illinois remains on the periphery of high pressure centered over
Ohio early this morning. To our northwest, convection has been
ramping up quickly over the last couple hours in central and
northwest Iowa along a warm front, as the low level jet increases
from the central Plains. The initial concern for this forecast
package involves how much of this convection will affect our area
today. However, the main forecast issue is with severe weather
potential Saturday afternoon and evening.
SHORT TERM...Today through Saturday Night:
The track of this developing thunderstorm cluster has necessitated
some noticeable changes to the going forecast for today. Earlier
grids mainly had the north half affected by the overnight
convection. Latest high-res models are all indicating a
southeast track, which would favor the western parts of the CWA.
However, very dry conditions above 850 mb were observed on our
evening sounding, and LAPS soundings for Peoria and Springfield at
1 am still showed a sizable dry wedge around 800 mb. Model
soundings show this eroding somewhat by mid morning but not
completely going away, so eastward extent is still a bit in
question. Will have the highest PoP`s from around Rushville to
Jacksonville, with lower chances spreading eastward as far as
I-57. Rain chances should be diminishing during the afternoon as
the atmosphere becomes more capped.
Evening models in general agreement with a shortwave tracking
along the periphery of the upper ridge to our southwest, but
convective alignment is more variable. The general consensus is
for a convective complex to develop to our north by late evening.
The ECMWF and GEM track this southeast and just brush by the
forecast area, while the NAM and GFS show some development
extending southwest along a frontal boundary into Kansas. Have not
made much change here at this point, since leftover boundaries
from the daytime activity may also contribute and are not
adequately handled by the synoptic models.
The frontal boundary will likely hang up somewhere in the I-72
vicinity on Saturday. Have gone with only slight chance PoP`s
during the morning, then increased them to around 30-40% in the
afternoon as the cap starts to erode. Very unstable conditions
will be developing, as dew points rise into the mid 70s and yield
CAPE values well over 3000 J/kg. 0-6km shear around 35 knots is
progged by evening, when the best storm chances in our area are
likely. Latest SPC Day2 outlook shows 30% severe probabilities
over the entire forecast area, with damaging winds favored.
Precipitable waters rising to just over 2 inches will also result
in locally heavy rains, and the ECMWF and GFS indicate some
training echoes could also be a concern.
Some secondary concerns also exist on Saturday for heat advisory
potential. With dew points rising into the mid 70s, am expecting
heat index values of 100-102 over most areas except perhaps along
and north of I-74. This is just shy of the 105F criteria for this
area.
LONG TERM...Sunday through Thursday:
Any lingering rain on Sunday will likely be in the morning, before
a cold front passes. This will be ahead of an upper low, currently
entering southwest Saskatchewan, that will be opening up as it
drops southeast through the Great Lakes region. This will evolve
into a broad upper trough that will dominate the eastern U.S.
throughout the week, bringing another period of cooler conditions.
Monday is likely to be the coolest day, with highs mainly in the
mid 70s, and comfortable humidity levels to persist much of the
work week.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1058 AM EDT FRI JUL 25 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 248 AM EDT FRI JUL 25 2014
DRY AND COMFORTABLE WEATHER WILL GIVE WAY TO WARM...HUMID AND
STORMY WEATHER THIS WEEKEND AS A COLD FRONT GRADUALLY DROPS
SOUTHEAST ACROSS THE AREA. SEVERE STORMS ARE A POSSIBILITY BY LATE
SATURDAY. MEANWHILE...AN UPPER WAVE WILL DROP SOUTHEAST ACROSS THE
LOWER GREAT LAKES SUNDAY NIGHT PUSHING THE FRONT TO THE SOUTHERN
STATES AND ALLOWING FOR MORE BELOW NORMAL TEMPERATURES NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1036 AM EDT FRI JUL 25 2014
HIGH LEVEL CLOUD DEBRIS EXPANDING INTO THE REGION THIS MORNING
FROM ONGOING CONVECTION OVER THE MID MISSISSIPPI VALLEY. TEMPS
WERE MAINLY IN THE 60S AT 14Z.
CONVECTION ACROSS EASTERN IOWA AND WESTERN ILLINOIS EXPECTED TO
PROPAGATE SOUTHEAST ALONG THE MISSISSIPPI RIVER IN CLOSER
PROXIMITY TO THE WARM FRONT. CENTRAL INDIANA REMAINS UNDER THE
PROTECTION OF THE SLOWLY DEPARTING HIGH PRESSURE...WITH
MESOANALYSIS SHOWING PWATS STILL BELOW 1 INCH AND AN ABUNDANCE OF
DRY AIR BELOW 15KFT. AIRMASS WILL SLOWLY MOISTEN AS THE AFTERNOON
PROGRESSES AND THE WARM FRONT APPROACHES THE WABASH VALLEY.
HOWEVER...CURRENT HRRR LOOKS FAR TOO AGGRESSIVE IN SPREADING
PRECIP INTO THE REGION OVER THE NEXT 6 HOURS...ESPECIALLY
CONSIDERING THE AMBIENT AIRMASS. MID AND HIGH LEVEL CLOUDS WILL BE
THE PRIMARY IMPACT...LIMITING SUNSHINE AND TEMP RISES A BIT MORE
THAN EARLIER THOUGHT. HAVE THEREFORE BUMPED HIGHS DOWN A COUPLE
DEGREES AND INCREASED CLOUD COVERAGE THROUGH THE REMAINDER OF THE
DAY. ANY PRECIP IS LIKELY TO HOLD OFF IN FAR NORTHWEST COUNTIES
UNTIL EARLY EVENING WITH THE APPROACH OF THE FRONT.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 248 AM EDT FRI JUL 25 2014
A CONVECTIVELY ACTIVE SHORT TERM WILL PROVIDE MANY CHALLENGES TO THE
FORECAST..NOT THE LEAST OF WHICH IS THE POTENTIAL FOR SEVERE WEATHER
AND HEAVY RAIN SATURDAY PM...ILLUSTRATED BY THE DAY2 SPC OUTLOOK.
MODELS ARE IN GOOD AGREEMENT THAT A SHARP UPPER TROUGH WILL DROP
SOUTHEAST ACROSS THE EASTERN GREAT LAKES AND OHIO ON SUNDAY NIGHT
WHICH WILL FORCE A STRONG COLD FRONT SOUTHEAST ACROSS THE FORECAST
AREA. THE FRONT WILL INTERACT WITH INCREASING MOISTURE AND
INSTABILITY AND RESULT IN THUNDERSTORM CHANCES STARTING FRIDAY NIGHT
AND CONTINUING THROUGH SUNDAY NIGHT. THE BEST CHANCES WILL BE
SATURDAY NIGHT AND SUNDAY MORNING AS A LOW LEVEL JET SETTLES ACROSS
SOUTH CENTRAL INDIANA RESULTING IN PRECIPITABLE WATER VALUES AROUND
2 INCHES THERE. IN ADDITION...UPPER JET WILL STRETCH OUT ACROSS THE
LOWER GREAT LAKES WITH EMBEDDED JET MAXIMA AIDING IN RAINFALL
EFFICIENCY AND SEVERE POTENTIAL. SO...WITH ABUNDANT
FORCING...INSTABILITY AND MOISTURE...POTENTIAL SEVERE MCS ACTIVITY
LOOKS LIKE A GOOD BET SATURDAY NIGHT WITH DAMAGING WINDS AND HEAVY
RAIN THE MAIN CONCERNS. IF THE ATMOSPHERE CAN RECOVER ENOUGH FROM
THE FRIDAY NIGHT AND SATURDAY NIGHT STORMS...COULD ALSO SEE A FEW
SEVERE STORMS DURING THE AFTERNOON AND EVENING HOURS SATURDAY AND
SUNDAY BEFORE THE COLD FRONT MOVES THROUGH SUNDAY NIGHT.
SIDED CLOSER TO THE COOLER 00Z NAM MOS FOR AFTERNOON HIGHS AS THE
00Z GFS AND JUL 24 00Z ECM LOOK TOO WARM BY SATURDAY CONSIDERING
CLOUD COVER AND EFFECT OF FRIDAY NIGHT AND SATURDAY MORNING
CONVECTION.
&&
.LONG TERM /MONDAY THROUGH THURSDAY NIGHT/...
ISSUED AT 340 AM EDT FRI JUL 25 2014
SCATTERED RAIN SHOWERS WILL BE POSSIBLE ACROSS CENTRAL INDIANA ON
MONDAY AS AN UPPER LEVEL TROUGH AND ASSOCIATED SURFACE COLD FRONT
DEPART THE AREA. AFTER THAT...HIGH PRESSURE WILL RESULT IN DRY
CONDITIONS THROUGH MID-WEEK. AT THAT POINT...MODELS BECOME
INCONSISTENT FOR THE END OF LONG TERM PERIOD. LATEST REGIONAL
INITIALIZATION IS PICKING UP ON AN UPPER TROUGH FOR THURSDAY...BUT
IS STRUGGLING WITH TIMING. DUE TO THE MODEL INCONSISTENCY...WILL
NOT DEVIATE FROM INITIALIZATION AT THIS TIME WHICH HAS PERIODS OF
SLIGHT CHANCE POPS FOR THURSDAY/THURSDAY NIGHT. TEMPS THROUGH THE
PERIOD WILL BE WELL BELOW NORMAL WITH HIGHS ONLY IN THE 70S AND
LOWS IN THE 50S. TEMPS WILL INCREASE SLIGHTLY BY THE END OF THE
PERIOD...BUT WILL STILL BE BELOW NORMAL.
&&
.AVIATION /DISCUSSION FOR THE 25/1500Z TAF ISSUANCE/...
ISSUED AT 1058 AM EDT FRI JUL 25 2014
TWEAKED CURRENT CONDITIONS ONLY. PREVIOUS DISCUSSION FOLLOWS...
MID CLOUDS WILL INCREASE THROUGHOUT THE TAF PERIOD AS A WARM FRONT
APPROACHES CENTRAL INDIANA TODAY...BUT VFR WILL PREVAIL. AT THIS
TIME...CONFIDENCE IS ONLY HIGH ENOUGH TO INTRODUCE VCTS AT KLAF FOR
TONIGHT. ELSEWHERE...CHANCES COULD IMPROVE AFTER SAT 12Z AS WARM
FRONT MOVES CLOSER. WINDS WILL BE SOUTHWESTERLY AT 3 TO 7 KTS. WINDS
WILL INCREASE AT KIND AROUND MID-MORNING TOMORROW WITH SUSTAINED
SPEEDS OF 12 TO 14 KTS AND GUSTS UP TO 20 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...RYAN
SHORT TERM...MK
LONG TERM....TDUD
AVIATION...TDUD/CP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1036 AM EDT FRI JUL 25 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 248 AM EDT FRI JUL 25 2014
DRY AND COMFORTABLE WEATHER WILL GIVE WAY TO WARM...HUMID AND
STORMY WEATHER THIS WEEKEND AS A COLD FRONT GRADUALLY DROPS
SOUTHEAST ACROSS THE AREA. SEVERE STORMS ARE A POSSIBILITY BY LATE
SATURDAY. MEANWHILE...AN UPPER WAVE WILL DROP SOUTHEAST ACROSS THE
LOWER GREAT LAKES SUNDAY NIGHT PUSHING THE FRONT TO THE SOUTHERN
STATES AND ALLOWING FOR MORE BELOW NORMAL TEMPERATURES NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1036 AM EDT FRI JUL 25 2014
HIGH LEVEL CLOUD DEBRIS EXPANDING INTO THE REGION THIS MORNING
FROM ONGOING CONVECTION OVER THE MID MISSISSIPPI VALLEY. TEMPS
WERE MAINLY IN THE 60S AT 14Z.
CONVECTION ACROSS EASTERN IOWA AND WESTERN ILLINOIS EXPECTED TO
PROPAGATE SOUTHEAST ALONG THE MISSISSIPPI RIVER IN CLOSER
PROXIMITY TO THE WARM FRONT. CENTRAL INDIANA REMAINS UNDER THE
PROTECTION OF THE SLOWLY DEPARTING HIGH PRESSURE...WITH
MESOANALYSIS SHOWING PWATS STILL BELOW 1 INCH AND AN ABUNDANCE OF
DRY AIR BELOW 15KFT. AIRMASS WILL SLOWLY MOISTEN AS THE AFTERNOON
PROGRESSES AND THE WARM FRONT APPROACHES THE WABASH VALLEY.
HOWEVER...CURRENT HRRR LOOKS FAR TOO AGGRESSIVE IN SPREADING
PRECIP INTO THE REGION OVER THE NEXT 6 HOURS...ESPECIALLY
CONSIDERING THE AMBIENT AIRMASS. MID AND HIGH LEVEL CLOUDS WILL BE
THE PRIMARY IMPACT...LIMITING SUNSHINE AND TEMP RISES A BIT MORE
THAN EARLIER THOUGHT. HAVE THEREFORE BUMPED HIGHS DOWN A COUPLE
DEGREES AND INCREASED CLOUD COVERAGE THROUGH THE REMAINDER OF THE
DAY. ANY PRECIP IS LIKELY TO HOLD OFF IN FAR NORTHWEST COUNTIES
UNTIL EARLY EVENING WITH THE APPROACH OF THE FRONT.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 248 AM EDT FRI JUL 25 2014
A CONVECTIVELY ACTIVE SHORT TERM WILL PROVIDE MANY CHALLENGES TO THE
FORECAST..NOT THE LEAST OF WHICH IS THE POTENTIAL FOR SEVERE WEATHER
AND HEAVY RAIN SATURDAY PM...ILLUSTRATED BY THE DAY2 SPC OUTLOOK.
MODELS ARE IN GOOD AGREEMENT THAT A SHARP UPPER TROUGH WILL DROP
SOUTHEAST ACROSS THE EASTERN GREAT LAKES AND OHIO ON SUNDAY NIGHT
WHICH WILL FORCE A STRONG COLD FRONT SOUTHEAST ACROSS THE FORECAST
AREA. THE FRONT WILL INTERACT WITH INCREASING MOISTURE AND
INSTABILITY AND RESULT IN THUNDERSTORM CHANCES STARTING FRIDAY NIGHT
AND CONTINUING THROUGH SUNDAY NIGHT. THE BEST CHANCES WILL BE
SATURDAY NIGHT AND SUNDAY MORNING AS A LOW LEVEL JET SETTLES ACROSS
SOUTH CENTRAL INDIANA RESULTING IN PRECIPITABLE WATER VALUES AROUND
2 INCHES THERE. IN ADDITION...UPPER JET WILL STRETCH OUT ACROSS THE
LOWER GREAT LAKES WITH EMBEDDED JET MAXIMA AIDING IN RAINFALL
EFFICIENCY AND SEVERE POTENTIAL. SO...WITH ABUNDANT
FORCING...INSTABILITY AND MOISTURE...POTENTIAL SEVERE MCS ACTIVITY
LOOKS LIKE A GOOD BET SATURDAY NIGHT WITH DAMAGING WINDS AND HEAVY
RAIN THE MAIN CONCERNS. IF THE ATMOSPHERE CAN RECOVER ENOUGH FROM
THE FRIDAY NIGHT AND SATURDAY NIGHT STORMS...COULD ALSO SEE A FEW
SEVERE STORMS DURING THE AFTERNOON AND EVENING HOURS SATURDAY AND
SUNDAY BEFORE THE COLD FRONT MOVES THROUGH SUNDAY NIGHT.
SIDED CLOSER TO THE COOLER 00Z NAM MOS FOR AFTERNOON HIGHS AS THE
00Z GFS AND JUL 24 00Z ECM LOOK TOO WARM BY SATURDAY CONSIDERING
CLOUD COVER AND EFFECT OF FRIDAY NIGHT AND SATURDAY MORNING
CONVECTION.
&&
.LONG TERM /MONDAY THROUGH THURSDAY NIGHT/...
ISSUED AT 340 AM EDT FRI JUL 25 2014
SCATTERED RAIN SHOWERS WILL BE POSSIBLE ACROSS CENTRAL INDIANA ON
MONDAY AS AN UPPER LEVEL TROUGH AND ASSOCIATED SURFACE COLD FRONT
DEPART THE AREA. AFTER THAT...HIGH PRESSURE WILL RESULT IN DRY
CONDITIONS THROUGH MID-WEEK. AT THAT POINT...MODELS BECOME
INCONSISTENT FOR THE END OF LONG TERM PERIOD. LATEST REGIONAL
INITIALIZATION IS PICKING UP ON AN UPPER TROUGH FOR THURSDAY...BUT
IS STRUGGLING WITH TIMING. DUE TO THE MODEL INCONSISTENCY...WILL
NOT DEVIATE FROM INITIALIZATION AT THIS TIME WHICH HAS PERIODS OF
SLIGHT CHANCE POPS FOR THURSDAY/THURSDAY NIGHT. TEMPS THROUGH THE
PERIOD WILL BE WELL BELOW NORMAL WITH HIGHS ONLY IN THE 70S AND
LOWS IN THE 50S. TEMPS WILL INCREASE SLIGHTLY BY THE END OF THE
PERIOD...BUT WILL STILL BE BELOW NORMAL.
&&
.AVIATION /DISCUSSION FOR THE 25/1200Z TAF ISSUANCE/...
ISSUED AT 728 AM EDT FRI JUL 25 2014
THE FEW HOURS OF IFR CONDITIONS AT OUTLYING SITES EARLY THIS MORNING
HAVE ENDED...AND VFR CONDITIONS SHOULD NOW CONTINUE TO HOLD
STEADY. MID CLOUDS WILL INCREASE THROUGHOUT THE TAF PERIOD AS A
WARM FRONT APPROACHES CENTRAL INDIANA TODAY...BUT VFR WILL PREVAIL.
AT THIS TIME...CONFIDENCE IS ONLY HIGH ENOUGH TO INTRODUCE VCTS AT
KLAF FOR TONIGHT. ELSEWHERE...CHANCES COULD IMPROVE AFTER SAT 12Z
AS WARM FRONT MOVES CLOSER. WINDS WILL BE SOUTHWESTERLY AT 3 TO 7
KTS. WINDS WILL INCREASE AT KIND AROUND MID-MORNING TOMORROW WITH
SUSTAINED SPEEDS OF 12 TO 14 KTS AND GUSTS UP TO 20 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...RYAN
SHORT TERM...MK
LONG TERM....TDUD
AVIATION...TDUD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1047 AM CDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 1041 AM CDT FRI JUL 25 2014
THE CURRENT THUNDERSTORM COMPLEX CONTINUES TO SLOWLY DECAY AS IT
MOVES EAST OF THE MISSISSIPPI. A MESO HIGH OVER NORTHEAST IOWA IS
STARTING TO COLLAPSE WHICH IS CAUSING A PERIOD OF STRONG WINDS ON
THE BACK SIDE OF THE PRECIPITATION.
NEW CONVECTION HAS DEVELOPED ACROSS NORTHERN IOWA WHICH APPEARS TO
BE ASSOCIATED WITH A WEAK THETA E GRADIENT. RECENT RADAR TRENDS
SHOW SOME WEAKENING OF THIS CONVECTION.
THE RAIN WILL END FROM WEST TO EAST THROUGH MID DAY AS WARMER
TEMPERATURES BUILDS IN ALOFT. THE POTENTIAL FOR CONVECTION WILL
HAVE TO BE RE-EVALUATED FOR THE AFTERNOON HOURS.
UPDATE ISSUED AT 700 AM CDT FRI JUL 25 2014
MCS OVER THE DVN CWA EARLY THIS MORNING WITH LOCALLY HEAVY RAINFALL
IN THE SOME OF THE STRONGER STORMS. IR SATELLITE SHOWED WARMING
TOPS IN OUR NORTHERN CWA WHICH ALSO IS INDICATED ON DOPPLER RADAR
WITH A WEAKENING TREND. THE ENTIRE MCS WILL GRADUALLY WEAKEN AS IT
PUSHES SOUTHEAST THIS MORNING AND THE HRRR MESO MODEL SHOWS THE BACK
EDGE OF THE MCS EXITING OUR SE CWA BY 1 PM. MANY AREAS SHOULD PICK
UP 1/4 TO 1/2 INCH OF RAIN WITH ISOLATED 1 INCH POSSIBLE.
&&
.SYNOPSIS...
ISSUED AT 345 AM CDT FRI JUL 25 2014
ELEVATED CONVECTION HAS FIRED IN THE PAST FEW HOURS ACROSS PORTIONS
OF NORTHERN/CENTRAL IA AND INTO WESTERN/SOUTHERN MN. THIS IS OCCURRING
ON THE NOSE OF A 50+ KNOT LOW LEVEL JET ON THE EASTERN EDGE OF A CAPPED
ELEVATED MIXED LAYER. SPC MESO ANALYSIS SHOWS THE BETTER MOISTURE
TRANSPORT IS STILL WEST OF THE DVN CWA WITH THE HIGHEST BULK SHEAR
VALUES IN SOUTHERN MN. PRECIPITABLE WATERS RANGE FROM 2.10 INCHES
IN WESTERN IA TO LESS THAN AN INCH IN NORTHERN IL. IR SATELLITE
LOOPS INDICATE TOPS CONTINUE TO RAPIDLY COOL AS THE THUNDERSTORM
ACTIVITY MOVES SOUTHEAST. A SHORT WAVE TROUGH WAS ALSO LIFTING
EASTWARD ACROSS THE NORTHERN/CENTRAL PLAINS AROUND A CLOSED UPPER
LOW IN SOUTHERN ALBERTA.
A COOL/STABLE SURFACE LAYER WAS NOTED ACROSS THE DVN CWA WITH 3 AM
TEMPERATURES IN THE MID 50S TO MID 60S...WHILE READINGS WERE WELL
INTO THE 70S TO LOWER 80S IN THE CENTRAL/SOUTHERN PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT FRI JUL 25 2014
FORECAST FOCUS ON THUNDERSTORMS MAINLY THIS MORNING AND TEMPERATURES.
TODAY...FORCING AND RAPIDLY INCREASING MOISTURE WILL ALLOW THUNDERSTORMS
TO CONTINUE TO DEVELOP/SPREAD ACROSS MUCH OF THE CWA THIS MORNING ON
THE NOSE OF THE STRONG LOW LEVEL JET...AS IT VEERS INTO THE AREA. DUE
TO THE ELEVATED NATURE OF THE STORMS AND THE COOL/STABLE SURFACE ENVIRONMENT
SEVERE WEATHER IS NOT EXPECTED. FREEZING LEVELS ARE QUITE HIGH AT NEARLY
15K FT. HOWEVER...SOME OF THE STRONGER STORMS MAY PRODUCE FREQUENT LIGHTNING...
SUB-SEVERE HAIL AND LOCALLY HEAVY RAINFALL. LATER THIS MORNING THE LOW
LEVEL JET WILL WEAKEN CONSIDERABLY ALONG WITH THE PASSAGE OF THE SHORT
WAVE TROUGH. A STRENGTHENING CAP WILL ALSO SPREAD EASTWARD INTO THE
CWA. THIS WILL DIMINISH OR END THE THUNDERSTORM ACTIVITY BY AFTERNOON
SO WILL HAVE LIKELY TO CATEGORICAL POPS THIS MORNING AND ONLY SMALL
POPS THIS AFTERNOON. EXPECTING EXTENSIVE CLOUD COVER TO LINGER INTO
THE AFTERNOON ESPECIALLY IN OUR EAST WHILE MORE SUNSHINE DEVELOPS IN
OUR WEST. MODELS REALLY SURGE THE WARM 850 MB TEMPERATURES INTO OUR
WESTERN CWA WITH +20C NOTED LATER IN THE AFTERNOON. I WILL FORECAST
MAXIMUM TEMPERATURES RANGING FROM THE MID 80S SW TO THE MID 70S NE.
HOWEVER...DEPENDING ON AMOUNT OF LINGERING CLOUDS (OR LACK OF) THIS
AFTERNOON THESE READINGS MAY NEED TO BE RE-VISITED.
TONIGHT...STRONG CAPPING ENVIRONMENT OVERSPREADS THE CWA EXCEPT
POSSIBLY OUR FAR EASTERN CWA. MODELS INSIST ON DEVELOPING CONVECTION
IN OUR EASTERN CWA AS THE LOW LEVEL JET STRENGTHENS AGAIN...BUT THERE
IS THE POTENTIAL THE STORMS MAY END UP FIRING EAST OF THE DVN CWA.
WILL HAVE CHANCE POPS TO COVER THIS SCENARIO BUT CONFIDENCE IS RATHER
LOW AT THIS POINT. THIS WILL BE A WARMER NIGHT WITH MINIMUM TEMPERATURES
IN THE MID 60S TO LOWER 70S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 345 AM CDT FRI JUL 25 2014
CHANCES FOR SHOWERS AND STORMS THROUGH THE WEEKEND THEN MAINLY DRY AND
COOLER MUCH OF NEXT WEEK.
SAT-SAT NGT...COVERAGE OF STORMS AND SEVERE POTENTIAL ARE THE MAIN
CHALLENGES. MODEL SOUNDINGS GENERALLY SHOW DECENT ELEVATED MIXED
LAYER OR CAP DEVELOPING OVER MUCH OF THE AREA SUPPRESSING CONVECTION
FOR MUCH OF THE DAY. THIS WILL ALSO SPELL VERY WARM AND HUMID
CONDITIONS WITH HIGHS MID 80S TO NEAR 90F AND DEWPTS UPPER 60S TO
LOWER 70S FOR PM HEAT INDICES FROM NEAR 90 NORTH TO AROUND 100 SOUTH.
SEVERAL FCST SOUNDINGS THOUGH SHOW THE CAP WEAKENING AFTER 20-21Z
WITH PASSAGE OF SFC-850 MB COOL FRONTS AND THEREFORE WOULD ANTICIPATE
INCREASING STORM COVERAGE BY LATE AFTN/EVE MAINLY SOUTH OF I-80
VICINITY OF FRONT AND ELEVATED CONVERGENCE AND MOISTURE ADVECTION ON
NOSE OF INCREASING SWLY LOW LEVEL JET. A FEW SEVERE STORMS POSSIBLE
GIVEN MODERATE TO STRONG INSTABILITY (SBCAPE 2500-3500 J/KG) AND
SHEAR (0-6KM 35-50 KTS). MAIN THREAT BEING DAMAGING WINDS WITH LARGE
HAIL RISK SECONDARY AND CONFINED TO SUPERCELLS OR DECENT MESOCYCLONES
GIVEN ABUNDANCE OF MOISTURE IN ATMOSPHERIC COLUMN CHARACTERIZED BY
PWATS OF 1.6-1.9 INCHES AND WARM CLOUD DEPTHS UP AROUND 13KFT AGL...
WHICH POSES RISK OF LOCALLY HEAVY RAIN OF 2+ INCHES WITH POTENTIAL
FOR BACKBUILDING AND ISOLATED HIGHER AMOUNTS WITH VEERED SWLY LOW LEVEL
JET.
SUN-SUN NGT...DIGGING PV ANOMALY FROM UPPER MIDWEST INTO GREAT LAKES
TO USHER IN SECONDARY AND STRONGER COOL FRONT SUNDAY PM. WILL SEE
CHANCES FOR ADDITIONAL SHOWERS AND STORMS MAINLY DURING THE PM INTO
EARLY EVE WITH THIS FRONT WITH BEST CHANCES OVER NORTHEAST 1/3-1/2 OF THE
CWA. NAM AND GFS SHOWING 40-50 KTS OF 0-6KM BULK SHEAR AND WITH
INVERTED V SOUNDINGS AND DRIER AIR ALOFT WILL NEED TO WATCH FOR POTENTIAL
OF MORE ORGANIZED AND STRONGER STORMS CONTAINING GUSTY WINDS AND HAIL.
SUNDAY LOOKS TO BE THE LAST WARM DAY FOR A WHILE... WHICH OF LATE MEANS
LAST DAY AROUND NORMAL.
MON-THU...MEDIUM RANGE MODELS AND ENSEMBLES IN GOOD AGREEMENT WITH THE
OVERALL PATTERN DEPICTING A DEEP UPPER TROUGH OVER THE EASTERN HALF OF THE
CONUS. THIS WILL RESULT IN ANOTHER PERIOD OF GENERALLY BELOW NORMAL
TEMPS...WHICH MAY FEATURE A MORNING OR TWO OF NEAR RECORD LOWS TUE-WED.
CHALLENGE ASIDE FROM TEMPS WILL BE WHETHER ANY PM SHOWER CHANCES EXIST
WITH THE COOLER AIR ALOFT AND ANY IMPULSES IN NORTHWEST FLOW... BUT TOO
FAR OUT AND PROBS APPEAR TOO LOW FOR MUCH MENTION OF PCPN UNTIL POSSIBLY
LATE WEEK AHEAD OF POTENTIALLY ANOTHER SHOT OF COOLER AIR BEYOND THE
SCOPE OF THE CURRENT EXTENDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 700 AM CDT FRI JUL 25 2014
SHOWERS AND THUNDERSTORMS WILL BE OVER THE TAF SITES THIS MORNING
WITH BRIEF MVFR CIGS/VIS OTHERWISE MAINLY VFR CONDS THROUGH TONIGHT.
SOUTH WINDS 10 TO 20 KNOTS TODAY THEN AROUND 10 KNOTS TONIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...05
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
702 AM CDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 700 AM CDT FRI JUL 25 2014
MCS OVER THE DVN CWA EARLY THIS MORNING WITH LOCALLY HEAVY RAINFALL
IN THE SOME OF THE STRONGER STORMS. IR SATELLITE SHOWED WARMING
TOPS IN OUR NORTHERN CWA WHICH ALSO IS INDICATED ON DOPPLER RADAR
WITH A WEAKENING TREND. THE ENTIRE MCS WILL GRADUALLY WEAKEN AS IT
PUSHES SOUTHEAST THIS MORNING AND THE HRRR MESO MODEL SHOWS THE BACK
EDGE OF THE MCS EXITING OUR SE CWA BY 1 PM. MANY AREAS SHOULD PICK
UP 1/4 TO 1/2 INCH OF RAIN WITH ISOLATED 1 INCH POSSIBLE.
&&
.SYNOPSIS...
ISSUED AT 345 AM CDT FRI JUL 25 2014
ELEVATED CONVECTION HAS FIRED IN THE PAST FEW HOURS ACROSS PORTIONS
OF NORTHERN/CENTRAL IA AND INTO WESTERN/SOUTHERN MN. THIS IS OCCURRING
ON THE NOSE OF A 50+ KNOT LOW LEVEL JET ON THE EASTERN EDGE OF A CAPPED
ELEVATED MIXED LAYER. SPC MESO ANALYSIS SHOWS THE BETTER MOISTURE
TRANSPORT IS STILL WEST OF THE DVN CWA WITH THE HIGHEST BULK SHEAR
VALUES IN SOUTHERN MN. PRECIPITABLE WATERS RANGE FROM 2.10 INCHES
IN WESTERN IA TO LESS THAN AN INCH IN NORTHERN IL. IR SATELLITE
LOOPS INDICATE TOPS CONTINUE TO RAPIDLY COOL AS THE THUNDERSTORM
ACTIVITY MOVES SOUTHEAST. A SHORT WAVE TROUGH WAS ALSO LIFTING
EASTWARD ACROSS THE NORTHERN/CENTRAL PLAINS AROUND A CLOSED UPPER
LOW IN SOUTHERN ALBERTA.
A COOL/STABLE SURFACE LAYER WAS NOTED ACROSS THE DVN CWA WITH 3 AM
TEMPERATURES IN THE MID 50S TO MID 60S...WHILE READINGS WERE WELL
INTO THE 70S TO LOWER 80S IN THE CENTRAL/SOUTHERN PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT FRI JUL 25 2014
FORECAST FOCUS ON THUNDERSTORMS MAINLY THIS MORNING AND TEMPERATURES.
TODAY...FORCING AND RAPIDLY INCREASING MOISTURE WILL ALLOW THUNDERSTORMS
TO CONTINUE TO DEVELOP/SPREAD ACROSS MUCH OF THE CWA THIS MORNING ON
THE NOSE OF THE STRONG LOW LEVEL JET...AS IT VEERS INTO THE AREA. DUE
TO THE ELEVATED NATURE OF THE STORMS AND THE COOL/STABLE SURFACE ENVIRONMENT
SEVERE WEATHER IS NOT EXPECTED. FREEZING LEVELS ARE QUITE HIGH AT NEARLY
15K FT. HOWEVER...SOME OF THE STRONGER STORMS MAY PRODUCE FREQUENT LIGHTNING...
SUB-SEVERE HAIL AND LOCALLY HEAVY RAINFALL. LATER THIS MORNING THE LOW
LEVEL JET WILL WEAKEN CONSIDERABLY ALONG WITH THE PASSAGE OF THE SHORT
WAVE TROUGH. A STRENGTHENING CAP WILL ALSO SPREAD EASTWARD INTO THE
CWA. THIS WILL DIMINISH OR END THE THUNDERSTORM ACTIVITY BY AFTERNOON
SO WILL HAVE LIKELY TO CATEGORICAL POPS THIS MORNING AND ONLY SMALL
POPS THIS AFTERNOON. EXPECTING EXTENSIVE CLOUD COVER TO LINGER INTO
THE AFTERNOON ESPECIALLY IN OUR EAST WHILE MORE SUNSHINE DEVELOPS IN
OUR WEST. MODELS REALLY SURGE THE WARM 850 MB TEMPERATURES INTO OUR
WESTERN CWA WITH +20C NOTED LATER IN THE AFTERNOON. I WILL FORECAST
MAXIMUM TEMPERATURES RANGING FROM THE MID 80S SW TO THE MID 70S NE.
HOWEVER...DEPENDING ON AMOUNT OF LINGERING CLOUDS (OR LACK OF) THIS
AFTERNOON THESE READINGS MAY NEED TO BE RE-VISITED.
TONIGHT...STRONG CAPPING ENVIRONMENT OVERSPREADS THE CWA EXCEPT
POSSIBLY OUR FAR EASTERN CWA. MODELS INSIST ON DEVELOPING CONVECTION
IN OUR EASTERN CWA AS THE LOW LEVEL JET STRENGTHENS AGAIN...BUT THERE
IS THE POTENTIAL THE STORMS MAY END UP FIRING EAST OF THE DVN CWA.
WILL HAVE CHANCE POPS TO COVER THIS SCENARIO BUT CONFIDENCE IS RATHER
LOW AT THIS POINT. THIS WILL BE A WARMER NIGHT WITH MINIMUM TEMPERATURES
IN THE MID 60S TO LOWER 70S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 345 AM CDT FRI JUL 25 2014
CHANCES FOR SHOWERS AND STORMS THROUGH THE WEEKEND THEN MAINLY DRY AND
COOLER MUCH OF NEXT WEEK.
SAT-SAT NGT...COVERAGE OF STORMS AND SEVERE POTENTIAL ARE THE MAIN
CHALLENGES. MODEL SOUNDINGS GENERALLY SHOW DECENT ELEVATED MIXED
LAYER OR CAP DEVELOPING OVER MUCH OF THE AREA SUPPRESSING CONVECTION
FOR MUCH OF THE DAY. THIS WILL ALSO SPELL VERY WARM AND HUMID
CONDITIONS WITH HIGHS MID 80S TO NEAR 90F AND DEWPTS UPPER 60S TO
LOWER 70S FOR PM HEAT INDICES FROM NEAR 90 NORTH TO AROUND 100 SOUTH.
SEVERAL FCST SOUNDINGS THOUGH SHOW THE CAP WEAKENING AFTER 20-21Z
WITH PASSAGE OF SFC-850 MB COOL FRONTS AND THEREFORE WOULD ANTICIPATE
INCREASING STORM COVERAGE BY LATE AFTN/EVE MAINLY SOUTH OF I-80
VICINITY OF FRONT AND ELEVATED CONVERGENCE AND MOISTURE ADVECTION ON
NOSE OF INCREASING SWLY LOW LEVEL JET. A FEW SEVERE STORMS POSSIBLE
GIVEN MODERATE TO STRONG INSTABILITY (SBCAPE 2500-3500 J/KG) AND
SHEAR (0-6KM 35-50 KTS). MAIN THREAT BEING DAMAGING WINDS WITH LARGE
HAIL RISK SECONDARY AND CONFINED TO SUPERCELLS OR DECENT MESOCYCLONES
GIVEN ABUNDANCE OF MOISTURE IN ATMOSPHERIC COLUMN CHARACTERIZED BY
PWATS OF 1.6-1.9 INCHES AND WARM CLOUD DEPTHS UP AROUND 13KFT AGL...
WHICH POSES RISK OF LOCALLY HEAVY RAIN OF 2+ INCHES WITH POTENTIAL
FOR BACKBUILDING AND ISOLATED HIGHER AMOUNTS WITH VEERED SWLY LOW LEVEL
JET.
SUN-SUN NGT...DIGGING PV ANOMALY FROM UPPER MIDWEST INTO GREAT LAKES
TO USHER IN SECONDARY AND STRONGER COOL FRONT SUNDAY PM. WILL SEE
CHANCES FOR ADDITIONAL SHOWERS AND STORMS MAINLY DURING THE PM INTO
EARLY EVE WITH THIS FRONT WITH BEST CHANCES OVER NORTHEAST 1/3-1/2 OF THE
CWA. NAM AND GFS SHOWING 40-50 KTS OF 0-6KM BULK SHEAR AND WITH
INVERTED V SOUNDINGS AND DRIER AIR ALOFT WILL NEED TO WATCH FOR POTENTIAL
OF MORE ORGANIZED AND STRONGER STORMS CONTAINING GUSTY WINDS AND HAIL.
SUNDAY LOOKS TO BE THE LAST WARM DAY FOR A WHILE... WHICH OF LATE MEANS
LAST DAY AROUND NORMAL.
MON-THU...MEDIUM RANGE MODELS AND ENSEMBLES IN GOOD AGREEMENT WITH THE
OVERALL PATTERN DEPICTING A DEEP UPPER TROUGH OVER THE EASTERN HALF OF THE
CONUS. THIS WILL RESULT IN ANOTHER PERIOD OF GENERALLY BELOW NORMAL
TEMPS...WHICH MAY FEATURE A MORNING OR TWO OF NEAR RECORD LOWS TUE-WED.
CHALLENGE ASIDE FROM TEMPS WILL BE WHETHER ANY PM SHOWER CHANCES EXIST
WITH THE COOLER AIR ALOFT AND ANY IMPULSES IN NORTHWEST FLOW... BUT TOO
FAR OUT AND PROBS APPEAR TOO LOW FOR MUCH MENTION OF PCPN UNTIL POSSIBLY
LATE WEEK AHEAD OF POTENTIALLY ANOTHER SHOT OF COOLER AIR BEYOND THE
SCOPE OF THE CURRENT EXTENDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 700 AM CDT FRI JUL 25 2014
SHOWERS AND THUNDERSTORMS WILL BE OVER THE TAF SITES THIS MORNING
WITH BRIEF MVFR CIGS/VIS OTHERWISE MAINLY VFR CONDS THROUGH TONIGHT.
SOUTH WINDS 10 TO 20 KNOTS TODAY THEN AROUND 10 KNOTS TONIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...HAASE
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...05
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS GAYLORD MI
957 AM EDT FRI JUL 25 2014
.SYNOPSIS...
ISSUED AT 303 AM EDT FRI JUL 25 2014
HIGH PRESSURE WILL GIVE WAY TO A FAST MOVING SYSTEM TONIGHT AND
SATURDAY. CLOUDS WILL BE ON THE INCREASE TODAY...WITH A CHANCE FOR
SHOWERS AND A FEW THUNDERSTORMS TONIGHT INTO THE START OF THE
WEEKEND. A MUCH STRONGER SYSTEM WILL ARRIVE TO END THE WEEKEND...
BRINGING BETTER POTENTIAL FOR SHOWERS SUNDAY AND SUNDAY NIGHT. A
RETURN TO MUCH BELOW NORMAL TEMPERATURES ON MONDAY...WITH ONLY A
SLOW MODERATION EXPECTED THROUGH THE REMAINDER OF THE WEEK.
&&
.UPDATE...
ISSUED AT 948 AM EDT FRI JUL 25 2014
RAIN SHOWERS OVER WISCONSIN ARE TRYING TO MAKE THEIR WAY INTO N
LOWER FOR THE AFTERNOON. WILL BE WATCHING THESE AS THEY SEEMED TO
BE HIGH BASED SHOWERS (9000-10000FT BASES) WITH SCT DECKS DOWN
LOWER. KAPX 12Z SOUNDING SHOWED LOTS OF DRY AIR, BUT ACROSS THE
LAKE KGRB 12Z SOUNDING SHOWED SOME MOISTENING BETWEEN 925 MB AND
750 MB. HOWEVER, BOTH SOUNDINGS SHOWED PRONOUNCED CAPPING
INVERSION AROUND 750 MB. SO WE ARE IN A WAIT AND SEE GAME, GUT
FEELING IS THAT WE SEE SOME SPRINKLES IN THE AFTERNOON, BUT NO
MEASURABLE RAIN SHOWERS. MAY HAVE TO BUMP THE POPS UP TO ISOLATED
SHOWERS IN NW LOWER DEPENDING ON THE TRENDS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 303 AM EDT FRI JUL 25 2014
...MORE CLOUDS AND A SHADE WARMER WITH STORM CHANCES TONIGHT...
IMPACTS: LIGHTNING...BUT NO SEVERE WEATHER EXPECTED.
CURRENT WEATHER AND SYNOPTIC PATTERN:
BROAD UPPER RIDGING SEEN OVER THE SW PART OF THE COUNTRY WHILE
TROUGHING IS STILL THE THEME OVER THE EASTERN CONUS. THE RIDGING HAS
BEEN SQUASHED DUE TO A WRAPPED UP CLOSED LOW DRIFTS ACROSS SW
CANADA. THIS HAS INDUCED LOW PRESSURE OVER EASTERN CANADA AND THE
NRN PLAINS. AN AXIS OF DEEP THETA-E AIR...LEADING EDGE OF STEEP
LAPSE RATES ALOFT (6.5C/KM-7.5C/KM) AND LLJ (45-55KT) CONVERGENCE
AHEAD OF THE PLAINS SFC LOW HAS RESULTED IN POCKETS OF SHOWERS AND
STORMS IN THE DAKOTAS DOWN TO NE. CLOSER TO HOME...AREA VAD WIND
PROFILES AND RUC ANALYSIS SHOWING A TROUGH AXIS AND H8 MOISTURE
ADVECTION FROM THE ARROWHEAD OF MN DOWN THROUGH WISCONSIN. THERE
WERE A FEW ELEVATED RETURNS...BUT ONLY A FEW SPRINKLES HITTING
GROUND PER AREA OBS. OVER NRN MICHIGAN...WE ARE STILL UNDER THE
INFLUENCE OF SFC HIGH PRESSURE...BUT THOSE SAME VAD WIND PROFILES
SHOW THAT THIS HAS SHIFTED JUST EAST OF US WITH A RETURN TO A SW
WIND. AIR MASS IS STILL QUITE DRY WITH PWATS RELATIVELY LOWER THAN
ANYWHERE NEARBY. ONLY A BAND OF HIGHER LEVEL CLOUD STREAMING DOWN
THROUGH THE NW FLOW ALOFT. THE DRY AIR AND MOSTLY CLEAR SKIES HAVE
ALLOWED TEMPERATURES TO FALL INTO THE LOWER HALF OF THE 40S IN THE
LOW LYING AREAS...WHILE COASTAL AREAS AND SOME EXPOSED HIGHER
TERRAIN ARE IN THE LOWER HALF OF THE 50S.
SYNOPTIC PATTERN/WEATHER EVOLUTION:
THE SFC HIGH GRADUALLY SINKS OFF TO THE SE TODAY...WHILE THE
SOUTHERLY PRESSURE GRADIENT TIGHTENS AND DRAWS IN MORE LOW LEVEL
MOISTURE THROUGH THE DAY AND NIGHT. THE INITIAL H8 TROUGH AND
MOISTURE ADVECTION WILL DRIFT OVERHEAD TODAY...AND MAYBE SOME
SPRINKLES ARE POSSIBLE EARLY THIS MORNING...BUT DAYTIME MIXING AND
DRYING OF THE LOWER LEVELS WILL MOST LIKELY SEAL OFF ANY CHANCES FOR
SPRINKLES TO HIT GROUND. THE MOISTURE WILL REVEAL ITSELF IN A HIGHER
BASED CUMULUS FIELD...BUT ALSO MAY GET STUCK UNDERNEATH AN INVERSION
IN FCST BFR SOUNDINGS. THIS COULD LEAD TO A PERIOD OF MOSTLY CLOUDY
SKIES...BUT REALLY DOUBT THIS WILL HAVE MUCH AFFECT ON RISING TEMPS
REACHING THE MIDDLE 70S MOST AREAS. THIS INVERSION AND DRY SFC TDS
RESULT IN A PRETTY PRONOUNCED CAPPING FOR THE ENTIRE DAY...WITH
LITTLE TO NO CHANCE FOR AFTERNOON CONVECTION.
THERE ARE DIFFERENCES IN HOW THIS LID EVOLVES OVER THE NIGHT...BUT
WE WILL AT LEAST BE TRENDING TOWARD MORE UNSTABLE CONDITIONS. SOME
SHORTWAVE ENERGY/VORTICITY EJECTS FROM AFOREMENTIONED CLOSED LOW
DRIFTING THROUGH SRN CANADA. THIS FORCING ARRIVES LATE EVENING AND
OVERNIGHT. WEAK LOW PRESSURE AND A WARM FRONT LIFT UP TOWARD/INTO
NRN MICHIGAN. THE SAME FCST BFR SOUNDINGS...IN A SCENARIO LIKE
THIS...WOULD LIKELY ERODE/SUPPRESS THE CAP...UNLIKE THE GFS
SUGGESTION. RATHER...WILL GO WITH SHOWERS AND EMBEDDED
GARDEN-VARIETY THUNDERSTORMS DEVELOPING LATE EVENING/OVERNIGHT.
NOTHING SEVERE ANTICIPATED...AS OUR LAPSE RATES AND OVERALL
INSTABILITY WILL NOT MIRROR CURRENT ENVIRONMENT ACROSS THE NRN
PLAINS. WE WILL ONLY HAVE SEVERAL HUNDRED J/KG MUCAPE WITH LAPSE
RATES ALOFT 6-6.5C/KM. THE GREATEST MUCAPE LIKELY TO BE DOWN AROUND
THE MANISTEE/CADILLAC AREAS...ALSO WHERE SOME ADDITIONAL LIFT
ASSISTANCE WILL BE PROVIDED BY UPPER DIVERGENCE IN SOMEWHAT OF A
DOUBLE JET STRUCTURE. WOULD GO WITH LIKELY CHANCES FOR SEEING
PRECIPITATION...BUT BULK OF INSTABILITY AND LLJ FORCING WILL ONCE
AGAIN BE ACROSS SRN WI/NRN IL/SRN LAKE MICHIGAN. THIS COULD BLOCK US
FROM SEEING SOME OF THE ACTION. REGARDLESS...LIKELY TO BE SOME
PRECIPITATION...BEST DESCRIPTION OF WHICH CAN BE PROVIDED BY LATER
SHIFTS AS THE EVENT UNFOLDS.
LOWS TONIGHT WILL LIKELY BE MILD WITH THICKENING CLOUDS...LOWER HALF
OF THE 60S MOST AREAS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 303 AM EDT FRI JUL 25 2014
...RAINY END TO THE WEEKEND/COOL TEMPERATURES ON THE WAY FOR THE
START OF NEXT WEEK...
HIGH IMPACT WEATHER POTENTIAL: NOT A BUNCH. CHANCES FOR A FEW
NON-SEVERE THUNDERSTORMS HEADING THROUGH THE WEEKEND.
PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: WHILE STILL PLENTY OF THE
FINER DETAILS TO WORK OUT...MUCH TALKED ABOUT TRANSITION TO A MORE
MERIDIONAL NOAM UPPER FLOW PATTERN STILL ON TARGET TO DEVELOP HEADING
INTO AND THROUGH NEXT WEEK. NO LINGERING DOUBT MICHIGAN WILL BE
CENTERED IN UNSEASONABLY CHILL PRODUCING TROUGH AXIS...WHICH WILL BE
A SLOW ONE TO DEPART ONCE IT DEVELOPS. PLAYERS FOR SUCH UNUSUAL
DEVELOPMENTS ALREADY ON THE TABLE...WITH LARGE NORTHERN QUEBEC GYRE
SIMPLY STUCK IN PLACE...ALL THE WHILE STRONG PACIFIC SHORTWAVE MAKES
STEADY EAST PROGRESS ACROSS THE SOUTHERN CANADIAN ROCKIES. THE
LATTER WILL SIMPLY REINFORCE AND EXTEND THE FORMER AS IT
SLING-SHOTS AROUND IT THROUGH EARLY NEXT WEEK. COMBINE THAT WITH
DEVELOPMENT OF FULLY MATURE GULF OF ALASKA TROUGH/WEST NOAM RIDGE
COUPLET (NOT TO MENTION ONE REALLY AMPLIFIED ATLANTIC RIDGE)...AND
ONE CAN SEE WHY A PATTERN MUCH MORE RESEMBLING THE COOL SEASON IS
EXPECTED.
PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS THROUGHOUT
AND EVOLUTION OF PERIODIC RAIN CHANCES. THUNDERSTORM POTENTIAL AND
INTENSITY WILL ALSO NEED ADDRESSING THIS WEEKEND.
DETAILS: SATURDAY CONTINUES TO REMAIN A CHALLENGE...WITH TIGHT
THETA-E GRADIENT AND SURGE OF BEST UPPER JET FORCING EXITING STAGE
RIGHT RATHER QUICKLY DURING THE MORNING. LEFT BEHIND WILL BE A MUCH
MORE MOIST LOW LEVEL AIRMASS...WITH DEWPOINTS EXPECTED TO BE UP IN
THE MID AND PERHAPS UPPER 60S. KINDA EXPECT WHAT EVER PUNCHES
THROUGH HERE TONIGHT WILL LARGELY EXIT DURING THE MORNING
HOURS...LEAVING NEXT LOW AMP WAVE AND DIURNAL DRIVEN DESTABILIZATION
TO DRIVE ADDITIONAL SHOWER AND STORM DEVELOPMENT. MOISTURE CROSS
SECTIONS SHOW GOOD TO EXCELLENT MOISTURE DEPTH UP THROUGH H7...WITH
AGGRESSIVE DRYING ABOVE THIS LAYER. MANIPULATING MODEL DERIVED
SOUNDINGS WITH ANTICIPATED DEWPOINTS/TEMPERATURES DOES YIELD
DEVELOPMENT OF UPWARDS OF 1K-1.5K J/KG OF ML CAPE DURING THE
AFTERNOON. THINK THIS MIGHT BE A TOUCH AGGRESSIVE...EXPECTING LOW
LEVELS TO BE NOT QUITE AS SATURATED AS GUIDANCE WOULD SUGGEST. WHILE
BEST DYNAMICS WILL HAVE EXITED...NOT ALL IS LOST...WITH MID LEVEL
JET ROTATING THROUGH THE SOUTHWEST LAKES...COMBINING WITH LAKE
INDUCED LOW LEVEL CONVERGENCE /PARTICULARLY IN NORTHEAST LOWER AND
INTERIOR EASTERN UPPER MICHIGAN/ AND SAID WEAK WAVE. ABOVE
DEFINITELY SUPPORTS SOME ADDITIONAL CONVECTIVE POTENTIAL...
ESPECIALLY IN CLIMATOLOGICALLY FAVORED AREAS. INHERITED FORECAST
ALREADY WELL TRENDED IN THIS DIRECTION...WITH ONLY SOME MASSAGING
NEEDED TO POP/WEATHER GRID. DECENT DEEP LAYER SHEAR OF 30 TO 40
KNOTS LARGELY OFFSET BY LIMITED MID LEVEL LAPSE RATES AND SKINNY
CAPE PROFILE UP THROUGH HAIL GROWTH ZONE. SO...IF STORMS CAN DEVELOP
(A BIG IF)...WOULD EXPECT THEM TO REMAIN BELOW SEVERE LIMITS.
LOSS OF INSTABILITY AND RAPID APPROACH OF SHORTWAVE RIDGING EXPECTED
TO BRING A MOSTLY DRY SATURDAY NIGHT. RATHER VIGOROUS CURRENT
SOUTHERN CANADA WAVE QUICKLY FOLLOWS FOR SUNDAY...AND WHEN COMBINED
WITH GOOD SLUG OF LEFT EXIT REGION UPPER JET DYNAMICS...LOOKS TO
BRING A RATHER WIDESPREAD SHOWER EVENT SUNDAY INTO SUNDAY NIGHT.
SYSTEM EVEN LOOKS TO TAKE ON COLD SEASON CHARACTERISTICS...WITH MORE
STEADY RAIN POTENTIAL IN FAVORED NORTH SIDE DEFORMATION FIELD. SOME
THUNDER THREAT REMAINS SUNDAY WITH OPPORTUNITY FOR SOME
DESTABILIZATION BEFORE BETTER FORCING ARRIVES.
TROUGHING DIGS IN AND STAYS THERE-ON-AFTER...PERHAPS LASTING THROUGH
ALL OF NEXT WEEK. COLDEST ANOMALIES EXPECTED TO SLIDE JUST OFF TO
OUR NORTHEAST. THAT SAID...COLD AIR ADVECTION ON FRONT SIDE OF
SPRAWLING NORTHERN PLAINS HIGH WILL BE IMPRESSIVE INDEED...ONCE
AGAIN NOT ALLOWING TEMPERATURES TO GET OUT OF THE 60S ON MONDAY. A
VERY SLOW MODERATION TO FOLLOW...WITH HIGHS WARMING A FEW DEGREES
EACH DAY THROUGH THURSDAY (EVEN BY THURSDAY...HIGHS WILL STILL BE A
FEW DEGREES BELOW NORMAL). DESPITE TROUGHING...JUST NOT OVERLY
IMPRESSED WITH RAIN CHANCES AFTER SUNDAY NIGHTS WAVE PASSAGE. DEEP
LAYER FLOW WILL REMAIN NORTH TO NORTHWEST...AND MID LEVEL
TEMPERATURE REALLY NEVER GET TOO COLD...REACHING THE NEGATIVE UPPER
TEENS AT H5 LATER MONDAY INTO TUESDAY. OF COURSE...ANY WAVES
ROTATING THROUGH WILL ONLY HELP THE SHOWER CAUSE...BUT TIMING AND
MAGNITUDE OF SUCH NOT POSSIBLE TO DETERMINE JUST YET. NO REASON TO
CHANGE THAT WHICH WAS INHERITED...FEATURING JUST ISOLATED/LOW CHANCE
SHOWER POTENTIAL DURING THE DAYTIME HOURS. THIS WILL CHANGE...OF
COURSE...BUT PLENTY OF TIME TO FIGURE THOSE DETAILS OUT IN THE
COMING DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 609 AM EDT FRI JUL 25 2014
...MAINLY VFR WITH CHANCES FOR SHOWERS AND STORMS TONIGHT...
SFC HIGH PRESSURE HAS EXITED SOUTHEAST ALLOWING FOR A LIGHT SW
RETURN FLOW. THIS GRADIENT TIGHTENS A TOUCH TODAY WITH GUSTS UP TO
15-18KTS EXPECTED...MAINLY ACROSS NW LOWER. CUMULUS AND SOME
HIGHER CLOUD EXPECTED TO ROLL ON THROUGH TODAY AND POSSIBLY GET
STUCK UNDERNEATH AN INVERSION FOR A PERIOD OF MORE CLOUDY
CONDITIONS. WEAK LOW PRESSURE AND A WARM FRONT ARRIVE TONIGHT WITH
THE CHANCE FOR SHOWERS AND STORMS AHEAD OF IT. EXACT EVOLUTION OF
THE PRECIPITATION NEBULOUS RIGHT NOW...WILL INCLUDE A VCSH FOR THE
NIGHT.
NO SEVERE WEATHER ANTICIPATED. BRIEF HEAVY RAIN AND LIGHTNING
HOWEVER.
&&
.MARINE...
ISSUED AT 303 AM EDT FRI JUL 25 2014
SW WINDS WILL INCREASE HEADING THROUGH TONIGHT...AHEAD OF SFC LOW
PRESSURE AND A WARM FRONT...WHICH WILL BRING AREAS OF SHOWERS AND
GARDEN-VARIETY STORMS TO THE GREAT LAKES. NOTHING SEVERE....AND
WINDS TO REMAIN ABOVE ADVISORY LEVELS. EXPECTING NO MORE THAN
20KTS..WHICH WILL LARGELY RESIDE ACROSS LAKE MICHIGAN. WINDS REMAIN
UNDER ADVISORY LEVELS SATURDAY AND SUNDAY IN WEAK GRADIENT. ANOTHER
SFC LOW CROSSES SUNDAY MORNING WITH A BETTER CHANCE FOR SHOWERS AND
STORMS...AND MUCH COOLER AIR SET TO ARRIVE THROUGH THE DAY SUNDAY
AND SUNDAY NIGHT.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JL
SYNOPSIS...MSB
SHORT TERM...SMD
LONG TERM...MSB
AVIATION...SMD
MARINE...SMD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
912 AM EDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 912 AM EDT FRI JUL 25 2014
ALTHOUGH INFLUX OF MSTR IN SW FLOW BTWN HI PRES IN THE MID ATLANTIC
STATES AND FALLING MSLP IN THE PLAINS ASSOCIATED WITH CLOSED H5 LO
MOVING INTO SASKATCHEWAN WL ALLOW SCT SHOWERS OVER WRN UPR MI THIS
MRNG TO SPREAD TO THE E THRU THE DAY...LOWERED THE CHC FOR TS GIVEN
HI STABILITY SHOWN ON THE 12Z INL AND ESPECIALLY THE GRB RAOBS AS
WELL AS RUC FCST SDNGS FOR EVEN IRONWOOD THRU 21Z.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 427 AM EDT FRI JUL 25 2014
THERE IS CURRENTLY A SFC RIDGE OVER THE CWA EXTENDING HIGH PRESSURE
OVER THE OHIO VALLEY. THIS RIDGE WILL BE FIGHTING OFF AN APPROACHING
LOW PRESSURE SYSTEM THAT IS CURRENTLY OVER THE SRN PORTION OT THE
ALBERTA/SASKATCHEWAN BORDER. BETWEEN THESE TWO FEATURES IS A 500MB
RIDGE...THE AXIS OF WHICH IS OVER THE ERN DAKOTAS AND INTO MANITOBA.
A SHORTWAVE IS CURRENTLY OVER FAR WRN LAKE SUPERIOR AND WILL MOVE
ALONG THE MI/WI BORDER THIS MORNING. SOME SHOWERS HAVE DEVELOPED
ALONG AND AHEAD OF THE SHORTWAVE...BUT WITH DRY LOW LEVELS HAVE ONLY
SEEN ONE OR TWO SFC OBS WITH VERY LIGHT RAIN...ALTHOUGH VIS REMAINED
10SM AND CIGS WERE AROUND 10KFT WITH THE SHOWERS.
THE SFC RIDGE WILL WEAKEN SOME THROUGH THE DAY WHILE BECOMING MORE
CONFINED TO THE FAR ERN/NRN CWA. MOISTURE WILL INCREASE OVER THE WRN
CWA THROUGH THE DAY SLOWLY...ALLOWING FOR INCREASED CHANCES OF
PRECIP THROUGH THE DAY ADDITIONAL WEAK SHORTWAVE ENERGY MOVES
THROUGH WHILE WAA INCREASES. STILL DO NOT HAVE MORE THAN LOW END
CHANCE POPS. WITH THE LINGERING DRY AIR OVER THE E...KEEP THEM DRY
THROUGH MOST OF THE DAY.
THE CONTINUALLY WEAKENING RIDGE PUSHES COMPLETELY E OF THE CWA FRI
NIGHT AS SHORTWAVE ENERGY AND A SFC TROUGH MOVES INTO THE CENTRAL
CWA BY LATE IN THE NIGHT. MAINTAINED CHANCE POPS INTO FRI NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 451 AM EDT FRI JUL 25 2014
A SOMEWHAT ACTIVE WEATHER PATTERN WILL BE IN PLACE ACROSS THE REGION
THROUGH THE WEEKEND...WITH A SIGNIFICANT COOLDOWN STARTING SUNDAY
AND EXTENDING INTO NEXT WEEK.
ON SATURDAY...THE FORECAST AREA WILL REMAIN UNDER ZONAL W-NW FLOW
ALOFT WITH THE LEFT EXIT REGION OF THE JET AND ASSOCIATED SHORT
WAVE EXITING TO THE EAST. ANY REMAINING SHOWER ACTIVITY FROM FRI
NIGHT SHOULD EXIT AS WELL AS DRY ADVECTION MOVES ACROSS THE AREA.
THIS WILL ALLOW FOR CLEARING SKIES WITH TEMPERATURES TO WARM INTO
THE MID-UPPER 70S ACROSS THE AREA. ALL THE NUMERICAL GUIDANCE
SUGGEST THAT INSTABILITY WILL INCREASE ACROSS THE EASTERN HALF OF
THE FORECAST AREA DURING THE AFTERNOON IN RESPONSE TO THE DIURNAL
HEATING. ALTHOUGH THE FORECAST CAPE VALUES OF 1000-2000 J/KG IS
LIKELY TOO HIGH DUE TO THE NORMAL HIGH BIAS OF SFC DEW
POINTS...THERE WILL LIKELY STILL BE INSTABILITY OF AT LEAST 1000
J/KG DURING THE LATE MORNING/AFTERNOON SIMPLY DUE TO THE STEEPER
LAPSE RATES ALOFT OF 6.5 C/KM. AS SUCH...HAVE OPTED TO MAINTAIN
CHANCE POPS ACROSS THE EASTERN LAKE BREEZE AREAS DURING THE
AFTERNOON HOURS ESPECIALLY WITH THE NAM AND GFS KEEPING THE LEFT
EXIT REGION OF THE JET AND ASSOCIATED WEAK Q-VECTOR CONVERGENCE IN
THIS AREA DURING THE AFTERNOON. THE BIG LIMITING FACTOR FOR MORE
WIDESPREAD CONVECTION WILL BE THE DRY AIR ALOFT...AND LACK OF
SIGNIFICANT LOW LEVEL FORCING OTHER THAN THE LAKE BREEZE ACTIVITY.
THIS AGREES WELL WITH THE HIGH RES NUMERICAL GUIDANCE THAT SUGGEST A
FEW STORMS ALONG THE LAKE BREEZE DURING THE DAY.
ON SATURDAY NIGHT INTO SUNDAY...THE UPPER LOW CURRENTLY OVER ALBERTA
WILL MOVE TOWARD THE AREA. MEANWHILE...THE UPPER LOW NE OF JAMES BAY
WILL RETROGRADE SLIGHTLY TO THE WEST AND SOUTH. THESE TWO FEATURES
WILL ALLOW FOR THE FRONT TO THE NORTH OF THE AREA TO MOVE ACROSS THE
REGION LATE SAT NIGHT INTO SUNDAY MORNING. AS THIS OCCURS...LOW
PRESSURE ASSOCIATED WITH THE UPPER LOW TO THE WEST WILL MOVE ALONG
THE FRONT ON SAT NIGHT INTO SUNDAY...TRACKING SOUTH OF THE AREA.
SHOWER AND ISOLATED STORMS WILL MOVE INTO THE AREA LATER SAT NIGHT
AHEAD OF THE UPPER LOW...THEN SPREAD ACROSS THE ENTIRE FORECAST AREA
ON SUNDAY. SUNDAY SHOULD END UP BEING A FAIRLY COOL AND DAMP DAY
WITH A BRISK /AT LEAST FOR SUMMER/ NORTH WIND. TEMPERATURES WILL
REMAIN FAIRLY STEADY IN THE 60S ACROSS THE AREA. IN FACT...IT WOULD
NOT BE SURPRISING IF TEMPS WILL FALL DURING THE DAY ESPECIALLY
CLOSER TO LAKE SUPERIOR AS 850MB TEMPS DROP TO 10C BY SUN EVENING.
THE GOOD NEWS IS THAT THE RAIN SHOULD RAPIDLY END LATE SUN AFTERNOON
INTO SUNDAY EVENING AS THE LOW MOVES EAST OF THE AREA. HOWEVER...BY
MONDAY MORNING 850MB TEMPS WILL DROP TO +6C WHICH WILL ALLOW FOR A
COOL NIGHT SUNDAY NIGHT. MONDAY WILL BE TRANQUIL AS WELL WITH STABLE
NORTH WINDS AND BUILDING HIGH PRESSURE ACROSS THE UPPER GREAT LAKES.
FOR THE TUE-THU TIME PERIOD...THE UPPER GREAT LAKES WILL REMAIN
BELOW NORMAL WITH THE DEEP TROUGH PERSISTING ACROSS THE EASTERN HALF
OF THE U.S. THROUGH THE PERIOD. THE UPPER LOW JUST EAST OF HUDSON
BAY WILL REMAIN FAIRLY STATIONARY THROUGH THE PERIOD. WEAK UPPER
LEVEL SHORT WAVES WILL ROTATE AROUND THE UPPER LOW AND ACROSS THE
AREA...WHICH WILL MAKE TIMING OF PRECIPITATION SOMEWHAT DIFFICULT.
HOWEVER...WITH THE COLD TEMPERATURES ALOFT COMBINED WITH FAIRLY
FREQUENT DISTURBANCES ALOFT...EXPECT THE BEST CHANCES FOR SHOWERS
AND STORMS TO BE DURING THE PEAK HEATING HOURS IN THE AFTERNOON AND
EARLY EVENING HOURS EACH DAY. OTHERWISE...TEMPERATURES WILL REMAIN
BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 744 AM EDT FRI JUL 25 2014
STILL HAVE SIGNIFICANT UNCERTAINTY IN EXACT TIMING/EXTENT OF
POSSIBLE SHOWERS THROUGH THE TAF PERIOD. SUBTLE ENERGY MOVING
THROUGH THE AREA OVER THE NEXT 24 HOURS WILL LEAD TO PERIODS OF
SHOWERS AND THUNDERSTORMS. DRY LOW LEVEL AIRMASS OVER THE AREA
INITIALLY WILL SLOWLY MOISTEN TODAY...SO LEFT PRECIP OUT OF THE
FORECAST THROUGH THIS AFTERNOON. EVEN AT IWD WHERE RADAR SHOWS
DECENT REFLECTIVITIES...LOW LEVEL DRY AIR IS PREVENTING SIGNIFICANT
PRECIP FROM MAKING IT TO THE GROUND...SO JUST PUT A TEMPO FOR -SHRA
THERE THIS MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 AM EDT FRI JUL 25 2014
EXPECT WINDS UNDER 15 KTS THRU SAT NIGHT WITH RELATIVELY WEAK PRES
GRADIENT DOMINATING THE UPPER LAKES. STRONGER N WINDS UP TO 20-25
KTS ARE POSSIBLE ON SUN INTO MON AS COOLER AIR INVADES THE AREA
UNDER TIGHTER GRADIENT BETWEEN HI PRES MOVING INTO THE NORTHERN
PLAINS AND LO PRES OVER THE SE GREAT LAKES. WINDS WILL DIMINISH ON
TUE AND BACK TOWARD THE W WITH CLOSER APPROACH OF HI PRES FROM THE
PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...TITUS
LONG TERM...MRD
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
615 AM EDT FRI JUL 25 2014
.SYNOPSIS...
ISSUED AT 303 AM EDT FRI JUL 25 2014
HIGH PRESSURE WILL GIVE WAY TO A FAST MOVING SYSTEM TONIGHT AND
SATURDAY. CLOUDS WILL BE ON THE INCREASE TODAY...WITH A CHANCE FOR
SHOWERS AND A FEW THUNDERSTORMS TONIGHT INTO THE START OF THE
WEEKEND. A MUCH STRONGER SYSTEM WILL ARRIVE TO END THE WEEKEND...
BRINGING BETTER POTENTIAL FOR SHOWERS SUNDAY AND SUNDAY NIGHT. A
RETURN TO MUCH BELOW NORMAL TEMPERATURES ON MONDAY...WITH ONLY A
SLOW MODERATION EXPECTED THROUGH THE REMAINDER OF THE WEEK.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 303 AM EDT FRI JUL 25 2014
...MORE CLOUDS AND A SHADE WARMER WITH STORM CHANCES TONIGHT...
IMPACTS: LIGHTNING...BUT NO SEVERE WEATHER EXPECTED.
CURRENT WEATHER AND SYNOPTIC PATTERN:
BROAD UPPER RIDGING SEEN OVER THE SW PART OF THE COUNTRY WHILE
TROUGHING IS STILL THE THEME OVER THE EASTERN CONUS. THE RIDGING HAS
BEEN SQUASHED DUE TO A WRAPPED UP CLOSED LOW DRIFTS ACROSS SW
CANADA. THIS HAS INDUCED LOW PRESSURE OVER EASTERN CANADA AND THE
NRN PLAINS. AN AXIS OF DEEP THETA-E AIR...LEADING EDGE OF STEEP
LAPSE RATES ALOFT (6.5C/KM-7.5C/KM) AND LLJ (45-55KT) CONVERGENCE
AHEAD OF THE PLAINS SFC LOW HAS RESULTED IN POCKETS OF SHOWERS AND
STORMS IN THE DAKOTAS DOWN TO NE. CLOSER TO HOME...AREA VAD WIND
PROFILES AND RUC ANALYSIS SHOWING A TROUGH AXIS AND H8 MOISTURE
ADVECTION FROM THE ARROWHEAD OF MN DOWN THROUGH WISCONSIN. THERE
WERE A FEW ELEVATED RETURNS...BUT ONLY A FEW SPRINKLES HITTING
GROUND PER AREA OBS. OVER NRN MICHIGAN...WE ARE STILL UNDER THE
INFLUENCE OF SFC HIGH PRESSURE...BUT THOSE SAME VAD WIND PROFILES
SHOW THAT THIS HAS SHIFTED JUST EAST OF US WITH A RETURN TO A SW
WIND. AIR MASS IS STILL QUITE DRY WITH PWATS RELATIVELY LOWER THAN
ANYWHERE NEARBY. ONLY A BAND OF HIGHER LEVEL CLOUD STREAMING DOWN
THROUGH THE NW FLOW ALOFT. THE DRY AIR AND MOSTLY CLEAR SKIES HAVE
ALLOWED TEMPERATURES TO FALL INTO THE LOWER HALF OF THE 40S IN THE
LOW LYING AREAS...WHILE COASTAL AREAS AND SOME EXPOSED HIGHER
TERRAIN ARE IN THE LOWER HALF OF THE 50S.
SYNOPTIC PATTERN/WEATHER EVOLUTION:
THE SFC HIGH GRADUALLY SINKS OFF TO THE SE TODAY...WHILE THE
SOUTHERLY PRESSURE GRADIENT TIGHTENS AND DRAWS IN MORE LOW LEVEL
MOISTURE THROUGH THE DAY AND NIGHT. THE INITIAL H8 TROUGH AND
MOISTURE ADVECTION WILL DRIFT OVERHEAD TODAY...AND MAYBE SOME
SPRINKLES ARE POSSIBLE EARLY THIS MORNING...BUT DAYTIME MIXING AND
DRYING OF THE LOWER LEVELS WILL MOST LIKELY SEAL OFF ANY CHANCES FOR
SPRINKLES TO HIT GROUND. THE MOISTURE WILL REVEAL ITSELF IN A HIGHER
BASED CUMULUS FIELD...BUT ALSO MAY GET STUCK UNDERNEATH AN INVERSION
IN FCST BFR SOUNDINGS. THIS COULD LEAD TO A PERIOD OF MOSTLY CLOUDY
SKIES...BUT REALLY DOUBT THIS WILL HAVE MUCH AFFECT ON RISING TEMPS
REACHING THE MIDDLE 70S MOST AREAS. THIS INVERSION AND DRY SFC TDS
RESULT IN A PRETTY PRONOUNCED CAPPING FOR THE ENTIRE DAY...WITH
LITTLE TO NO CHANCE FOR AFTERNOON CONVECTION.
THERE ARE DIFFERENCES IN HOW THIS LID EVOLVES OVER THE NIGHT...BUT
WE WILL AT LEAST BE TRENDING TOWARD MORE UNSTABLE CONDITIONS. SOME
SHORTWAVE ENERGY/VORTICITY EJECTS FROM AFOREMENTIONED CLOSED LOW
DRIFTING THROUGH SRN CANADA. THIS FORCING ARRIVES LATE EVENING AND
OVERNIGHT. WEAK LOW PRESSURE AND A WARM FRONT LIFT UP TOWARD/INTO
NRN MICHIGAN. THE SAME FCST BFR SOUNDINGS...IN A SCENARIO LIKE
THIS...WOULD LIKELY ERODE/SUPPRESS THE CAP...UNLIKE THE GFS
SUGGESTION. RATHER...WILL GO WITH SHOWERS AND EMBEDDED
GARDEN-VARIETY THUNDERSTORMS DEVELOPING LATE EVENING/OVERNIGHT.
NOTHING SEVERE ANTICIPATED...AS OUR LAPSE RATES AND OVERALL
INSTABILITY WILL NOT MIRROR CURRENT ENVIRONMENT ACROSS THE NRN
PLAINS. WE WILL ONLY HAVE SEVERAL HUNDRED J/KG MUCAPE WITH LAPSE
RATES ALOFT 6-6.5C/KM. THE GREATEST MUCAPE LIKELY TO BE DOWN AROUND
THE MANISTEE/CADILLAC AREAS...ALSO WHERE SOME ADDITIONAL LIFT
ASSISTANCE WILL BE PROVIDED BY UPPER DIVERGENCE IN SOMEWHAT OF A
DOUBLE JET STRUCTURE. WOULD GO WITH LIKELY CHANCES FOR SEEING
PRECIPITATION...BUT BULK OF INSTABILITY AND LLJ FORCING WILL ONCE
AGAIN BE ACROSS SRN WI/NRN IL/SRN LAKE MICHIGAN. THIS COULD BLOCK US
FROM SEEING SOME OF THE ACTION. REGARDLESS...LIKELY TO BE SOME
PRECIPITATION...BEST DESCRIPTION OF WHICH CAN BE PROVIDED BY LATER
SHIFTS AS THE EVENT UNFOLDS.
LOWS TONIGHT WILL LIKELY BE MILD WITH THICKENING CLOUDS...LOWER HALF
OF THE 60S MOST AREAS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 303 AM EDT FRI JUL 25 2014
...RAINY END TO THE WEEKEND/COOL TEMPERATURES ON THE WAY FOR THE
START OF NEXT WEEK...
HIGH IMPACT WEATHER POTENTIAL: NOT A BUNCH. CHANCES FOR A FEW
NON-SEVERE THUNDERSTORMS HEADING THROUGH THE WEEKEND.
PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: WHILE STILL PLENTY OF THE
FINER DETAILS TO WORK OUT...MUCH TALKED ABOUT TRANSITION TO A MORE
MERIDIONAL NOAM UPPER FLOW PATTERN STILL ON TARGET TO DEVELOP HEADING
INTO AND THROUGH NEXT WEEK. NO LINGERING DOUBT MICHIGAN WILL BE
CENTERED IN UNSEASONABLY CHILL PRODUCING TROUGH AXIS...WHICH WILL BE
A SLOW ONE TO DEPART ONCE IT DEVELOPS. PLAYERS FOR SUCH UNUSUAL
DEVELOPMENTS ALREADY ON THE TABLE...WITH LARGE NORTHERN QUEBEC GYRE
SIMPLY STUCK IN PLACE...ALL THE WHILE STRONG PACIFIC SHORTWAVE MAKES
STEADY EAST PROGRESS ACROSS THE SOUTHERN CANADIAN ROCKIES. THE
LATTER WILL SIMPLY REINFORCE AND EXTEND THE FORMER AS IT
SLING-SHOTS AROUND IT THROUGH EARLY NEXT WEEK. COMBINE THAT WITH
DEVELOPMENT OF FULLY MATURE GULF OF ALASKA TROUGH/WEST NOAM RIDGE
COUPLET (NOT TO MENTION ONE REALLY AMPLIFIED ATLANTIC RIDGE)...AND
ONE CAN SEE WHY A PATTERN MUCH MORE RESEMBLING THE COOL SEASON IS
EXPECTED.
PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS THROUGHOUT
AND EVOLUTION OF PERIODIC RAIN CHANCES. THUNDERSTORM POTENTIAL AND
INTENSITY WILL ALSO NEED ADDRESSING THIS WEEKEND.
DETAILS: SATURDAY CONTINUES TO REMAIN A CHALLENGE...WITH TIGHT
THETA-E GRADIENT AND SURGE OF BEST UPPER JET FORCING EXITING STAGE
RIGHT RATHER QUICKLY DURING THE MORNING. LEFT BEHIND WILL BE A MUCH
MORE MOIST LOW LEVEL AIRMASS...WITH DEWPOINTS EXPECTED TO BE UP IN
THE MID AND PERHAPS UPPER 60S. KINDA EXPECT WHAT EVER PUNCHES
THROUGH HERE TONIGHT WILL LARGELY EXIT DURING THE MORNING
HOURS...LEAVING NEXT LOW AMP WAVE AND DIURNAL DRIVEN DESTABILIZATION
TO DRIVE ADDITIONAL SHOWER AND STORM DEVELOPMENT. MOISTURE CROSS
SECTIONS SHOW GOOD TO EXCELLENT MOISTURE DEPTH UP THROUGH H7...WITH
AGGRESSIVE DRYING ABOVE THIS LAYER. MANIPULATING MODEL DERIVED
SOUNDINGS WITH ANTICIPATED DEWPOINTS/TEMPERATURES DOES YIELD
DEVELOPMENT OF UPWARDS OF 1K-1.5K J/KG OF ML CAPE DURING THE
AFTERNOON. THINK THIS MIGHT BE A TOUCH AGGRESSIVE...EXPECTING LOW
LEVELS TO BE NOT QUITE AS SATURATED AS GUIDANCE WOULD SUGGEST. WHILE
BEST DYNAMICS WILL HAVE EXITED...NOT ALL IS LOST...WITH MID LEVEL
JET ROTATING THROUGH THE SOUTHWEST LAKES...COMBINING WITH LAKE
INDUCED LOW LEVEL CONVERGENCE /PARTICULARLY IN NORTHEAST LOWER AND
INTERIOR EASTERN UPPER MICHIGAN/ AND SAID WEAK WAVE. ABOVE
DEFINITELY SUPPORTS SOME ADDITIONAL CONVECTIVE POTENTIAL...
ESPECIALLY IN CLIMATOLOGICALLY FAVORED AREAS. INHERITED FORECAST
ALREADY WELL TRENDED IN THIS DIRECTION...WITH ONLY SOME MASSAGING
NEEDED TO POP/WEATHER GRID. DECENT DEEP LAYER SHEAR OF 30 TO 40
KNOTS LARGELY OFFSET BY LIMITED MID LEVEL LAPSE RATES AND SKINNY
CAPE PROFILE UP THROUGH HAIL GROWTH ZONE. SO...IF STORMS CAN DEVELOP
(A BIG IF)...WOULD EXPECT THEM TO REMAIN BELOW SEVERE LIMITS.
LOSS OF INSTABILITY AND RAPID APPROACH OF SHORTWAVE RIDGING EXPECTED
TO BRING A MOSTLY DRY SATURDAY NIGHT. RATHER VIGOROUS CURRENT
SOUTHERN CANADA WAVE QUICKLY FOLLOWS FOR SUNDAY...AND WHEN COMBINED
WITH GOOD SLUG OF LEFT EXIT REGION UPPER JET DYNAMICS...LOOKS TO
BRING A RATHER WIDESPREAD SHOWER EVENT SUNDAY INTO SUNDAY NIGHT.
SYSTEM EVEN LOOKS TO TAKE ON COLD SEASON CHARACTERISTICS...WITH MORE
STEADY RAIN POTENTIAL IN FAVORED NORTH SIDE DEFORMATION FIELD. SOME
THUNDER THREAT REMAINS SUNDAY WITH OPPORTUNITY FOR SOME
DESTABILIZATION BEFORE BETTER FORCING ARRIVES.
TROUGHING DIGS IN AND STAYS THERE-ON-AFTER...PERHAPS LASTING THROUGH
ALL OF NEXT WEEK. COLDEST ANOMALIES EXPECTED TO SLIDE JUST OFF TO
OUR NORTHEAST. THAT SAID...COLD AIR ADVECTION ON FRONTSIDE OF
SPRAWLING NORTHERN PLAINS HIGH WILL BE IMPRESSIVE INDEED...ONCE
AGAIN NOT ALLOWING TEMPERATURES TO GET OUT OF THE 60S ON MONDAY. A
VERY SLOW MODERATION TO FOLLOW...WITH HIGHS WARMING A FEW DEGREES
EACH DAY THROUGH THURSDAY (EVEN BY THURSDAY...HIGHS WILL STILL BE A
FEW DEGREES BELOW NORMAL). DESPITE TROUGHING...JUST NOT OVERLY
IMPRESSED WITH RAIN CHANCES AFTER SUNDAY NIGHTS WAVE PASSAGE. DEEP
LAYER FLOW WILL REMAIN NORTH TO NORTHWEST...AND MID LEVEL
TEMPERATURE REALLY NEVER GET TOO COLD...REACHING THE NEGATIVE UPPER
TEENS AT H5 LATER MONDAY INTO TUESDAY. OF COURSE...ANY WAVES
ROTATING THROUGH WILL ONLY HELP THE SHOWER CAUSE...BUT TIMING AND
MAGNITUDE OF SUCH NOT POSSIBLE TO DETERMINE JUST YET. NO REASON TO
CHANGE THAT WHICH WAS INHERITED...FEATURING JUST ISOLATED/LOW CHANCE
SHOWER POTENTIAL DURING THE DAYTIME HOURS. THIS WILL CHANGE...OF
COURSE...BUT PLENTY OF TIME TO FIGURE THOSE DETAILS OUT IN THE
COMING DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 609 AM EDT FRI JUL 25 2014
...MAINLY VFR WITH CHANCES FOR SHOWERS AND STORMS TONIGHT...
SFC HIGH PRESSURE HAS EXITED SOUTHEAST ALLOWING FOR A LIGHT SW
RETURN FLOW. THIS GRADIENT TIGHTENS A TOUCH TODAY WITH GUSTS UP TO
15-18KTS EXPECTED...MAINLY ACROSS NW LOWER. CUMULUS AND SOME
HIGHER CLOUD EXPECTED TO ROLL ON THROUGH TODAY AND POSSIBLY GET
STUCK UNDERNEATH AN INVERSION FOR A PERIOD OF MORE CLOUDY
CONDITIONS. WEAK LOW PRESSURE AND A WARM FRONT ARRIVE TONIGHT WITH
THE CHANCE FOR SHOWERS AND STORMS AHEAD OF IT. EXACT EVOLUTION OF
THE PRECIPITATION NEBULOUS RIGHT NOW...WILL INCLUDE A VCSH FOR THE
NIGHT.
NO SEVERE WEATHER ANTICIPATED. BRIEF HEAVY RAIN AND LIGHTNING
HOWEVER.
&&
.MARINE...
ISSUED AT 303 AM EDT FRI JUL 25 2014
SW WINDS WILL INCREASE HEADING THROUGH TONIGHT...AHEAD OF SFC LOW
PRESSURE AND A WARM FRONT...WHICH WILL BRING AREAS OF SHOWERS AND
GARDEN-VARIETY STORMS TO THE GREAT LAKES. NOTHING SEVERE....AND
WINDS TO REMAIN ABOVE ADVISORY LEVELS. EXPECTING NO MORE THAN
20KTS..WHICH WILL LARGELY RESIDE ACROSS LAKE MICHIGAN. WINDS REMAIN
UNDER ADVISORY LEVELS SATURDAY AND SUNDAY IN WEAK GRADIENT. ANOTHER
SFC LOW CROSSES SUNDAY MORNING WITH A BETTER CHANCE FOR SHOWERS AND
STORMS...AND MUCH COOLER AIR SET TO ARRIVE THROUGH THE DAY SUNDAY
AND SUNDAY NIGHT.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SYNOPSIS...MSB
SHORT TERM...SMD
LONG TERM...MSB
AVIATION...SMD
MARINE...SMD
AREA FORECAST DISCUSSION
NWS DULUTH MN
903 AM CDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 903 AM CDT FRI JUL 25 2014
THE EARLY MORNING SHOWERS HAVE EXITED THE AREA. JUST A FEW
SPRINKLES REMAIN. HOWEVER...WITH THE UNSTABLE AIRMASS AND COLD
FRONT IN EASTERN ND...WAA/ISENTROPIC LIFT AHEAD OF SAID
FRONT...SHOWERS OR ISOLD THUNDERSTORMS MAY POP AT ANY TIME. HAVE
ADJUSTED POPS FOR THESE LATEST TRENDS.
UPDATE ISSUED AT 736 AM CDT FRI JUL 25 2014
UPDATED TO REFINE POPS AND REMOVE PRE-FIRST PERIOD BASED ON
CURRENT PRECIP AREA. THE SHOWERS AND THUNDERSTORMS SHOULD MOVE
SOUTH OUT OF THE FORECAST AREA BY 15Z. REST OF FCST UNCHANGED.
UPDATE ISSUED AT 430 AM CDT FRI JUL 25 2014
UPDATED TO INCREASE POPS ACROSS PORTIONS OF THE FORECAST AREA. AREA
OF SHOWERS AND THUNDERSTORMS MOVING ACROSS THOSE AREAS THIS
MORNING. THIS PRECIPITATION WILL END BY MID-MORNING. REST OF FCST UNCHANGED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 242 AM CDT FRI JUL 25 2014
SHORT TERM CONCERN IS PRECIPITATION CHANCE TODAY AND TONIGHT.
CURRENT SURFACE ANALYSIS INDICATES RAIN SHOWERS NORTH OF THE IRON
RANGE AND IN THE ARROWHEAD. THESE SHOWERS ARE ASSOCIATED WITH A WEAK
SHORTWAVE MOVING THROUGH THE AREA. THEY WILL CONTINUE MOVE
SOUTHEAST AND SLOWLY DISSIPATE EARLY THIS MORNING. THERE IS AN
AREA OF THUNDERSTORMS ALONG THE ND/SD/WRN MN BORDER MOVING ESE.
THE AREA HAS DECREASED IN INTENSITY OVER THE PAST HOUR. THE
NORTHERN EDGE OF THE PRECIPITATION MAY CLIP CASS AND CROW WING
COUNTIES THIS MORNING. A WEAK SURFACE TROUGH WILL MOVE THROUGH MN
TODAY AND NW WI TONIGHT. IT WILL BRING ANOTHER ROUND OF SHOWERS
AND THUNDERSTORMS. THERE WILL BE SOME INCREASED INSTABILITY WITH
THE TROUGH THIS AFTERNOON AND EVENING. MUCAPES ARE
1500-2000...SHEAR IS 20-40...AND SOME SUN TODAY. SPC HAS THE
FORECAST AREA IN A 5% PROBABILITY FOR WIND/HAIL WITH THE MARGINAL
INSTABILITY.
AN AREA OF WEAK HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE
WEST LATE THIS EVENING. THIS WILL END THE THREAT FOR PRECIPITATION
FOR LATE FRIDAY NIGHT AND SATURDAY. HOWEVER..BY THE AFTERNOON...AN
AREA OF LOW PRESSURE ALONG WITH A UPPER TROUGH WILL MOVE INTO
WESTERN MINNESOTA AND WILL EFFECT THE REGION SATURDAY NIGHT.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 242 AM CDT FRI JUL 25 2014
THE MODELS ARE IN PRETTY GOOD AGREEMENT THROUGH MUCH OF THE
PERIOD. AN UPPER TROUGH OVER SOUTHERN MANITOBA SATURDAY EVENING
WILL DROP INTO NORTHERN MINNESOTA BY 12Z SUN...THEN CONTINUE INTO
SOUTHERN WISCONSIN BY SUNDAY EVENING. A SURFACE LOW/TROUGH AXIS
WILL BE ASSOCIATED WITH THIS UPPER WAVE. SHOWERS AND A FEW
THUNDERSTORMS WILL INCREASE IN COVERAGE SATURDAY NIGHT INTO SUNDAY
MORNING...THEN DECREASE FROM NORTH TO SOUTH SUNDAY
AFTERNOON/EVENING. SUNDAY NIGHT SHOULD BE DRY. WE HAVE THE HIGHEST
POPS OVER THE EASTERN PORTION OF THE NORTHLAND LATE SATURDAY NIGHT
INTO SUNDAY MORNING.
HIGH PRESSURE WILL THEN LEAD TO MAINLY DRY CONDITIONS SUNDAY NIGHT
INTO MONDAY NIGHT. THERE MAY BE A FEW SHOWERS TUESDAY INTO WEDNESDAY
OVER THE EASTERN HALF OF THE NORTHLAND WITH A SERIES OF SHORTWAVES
MOVING THROUGH IN THE NORTHERLY FLOW ALOFT. WE ALSO HAVE A SMALL
CHANCE FOR SHOWERS/STORMS THURSDAY FOR MOST AREAS.
THE PERIOD WILL START OUT WITH BELOW NORMAL TEMPERATURES
SUNDAY...WITH HIGHS IN THE MID SIXTIES TO LOWER SEVENTIES.
TEMPERATURES WILL THEN MODERATE THROUGH THE REST OF THE
PERIOD...REACHING THE UPPER SEVENTIES TO LOWER EIGHTIES BY THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 632 AM CDT FRI JUL 25 2014
SHOWERS AND A FEW THUNDERSTORMS WERE MOVING THROUGH
CENTRAL/EASTERN PORTIONS OF THE NORTHLAND EARLY THIS MORNING. WE
EXPECT A LULL IN COVERAGE TO DEVELOP THIS MORNING...THEN
ADDITIONAL DEVELOPMENT THIS AFTERNOON AHEAD OF THE SURFACE
BOUNDARY THAT WILL ONLY MOVE SLOWLY FROM WESTERN MINNESOTA EARLY
THIS AFTERNOON TOWARD THE EAST.
AN AREA OF MVFR/IFR CEILINGS HAVE DEVELOPED OVER WEST CENTRAL
MINNESOTA INTO CENTRAL MINNESOTA. THE RAP IS SUGGESTS THESE
CEILINGS WILL SPREAD NORTH AND EAST TODAY. HOWEVER...THE COVERAGE
CURRENTLY IS NOT AS GREAT AS THE RAP SUGGESTS. WE FEEL MOST
CONFIDENT KBRD WILL SEE THE LOWER CEILINGS AND ADDED A TEMPO GROUP
FOR THE REST OF THE TAF SITES BY MID TO LATE MORNING.
THE COVERAGE OF THE PRECIPITATION WILL DIMINISH THIS EVENING AND
SOME FOG WILL BE POSSIBLE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 75 59 82 59 / 50 30 50 50
INL 76 57 81 56 / 40 50 50 60
BRD 80 58 84 60 / 40 10 30 40
HYR 76 62 85 58 / 50 30 30 50
ASX 77 61 81 57 / 30 40 40 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...STEWART
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
736 AM CDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 736 AM CDT FRI JUL 25 2014
UPDATED TO REFINE POPS AND REMOVE PRE-FIRST PERIOD BASED ON
CURRENT PRECIP AREA. THE SHOWERS AND THUNDERSTORMS SHOULD MOVE
SOUTH OUT OF THE FORECAST AREA BY 15Z. REST OF FCST UNCHANGED.
UPDATE ISSUED AT 430 AM CDT FRI JUL 25 2014
UPDATED TO INCREASE POPS ACROSS PORTIONS OF THE FORECAST AREA. AREA
OF SHOWERS AND THUNDERSTORMS MOVING ACROSS THOSE AREAS THIS
MORNING. THIS PRECIPITATION WILL END BY MID-MORNING. REST OF FCST UNCHANGED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 242 AM CDT FRI JUL 25 2014
SHORT TERM CONCERN IS PRECIPITATION CHANCE TODAY AND TONIGHT.
CURRENT SURFACE ANALYSIS INDICATES RAIN SHOWERS NORTH OF THE IRON
RANGE AND IN THE ARROWHEAD. THESE SHOWERS ARE ASSOCIATED WITH A WEAK
SHORTWAVE MOVING THROUGH THE AREA. THEY WILL CONTINUE MOVE
SOUTHEAST AND SLOWLY DISSIPATE EARLY THIS MORNING. THERE IS AN
AREA OF THUNDERSTORMS ALONG THE ND/SD/WRN MN BORDER MOVING ESE.
THE AREA HAS DECREASED IN INTENSITY OVER THE PAST HOUR. THE
NORTHERN EDGE OF THE PRECIPITATION MAY CLIP CASS AND CROW WING
COUNTIES THIS MORNING. A WEAK SURFACE TROUGH WILL MOVE THROUGH MN
TODAY AND NW WI TONIGHT. IT WILL BRING ANOTHER ROUND OF SHOWERS
AND THUNDERSTORMS. THERE WILL BE SOME INCREASED INSTABILITY WITH
THE TROUGH THIS AFTERNOON AND EVENING. MUCAPES ARE
1500-2000...SHEAR IS 20-40...AND SOME SUN TODAY. SPC HAS THE
FORECAST AREA IN A 5% PROBABILITY FOR WIND/HAIL WITH THE MARGINAL
INSTABILITY.
AN AREA OF WEAK HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE
WEST LATE THIS EVENING. THIS WILL END THE THREAT FOR PRECIPITATION
FOR LATE FRIDAY NIGHT AND SATURDAY. HOWEVER..BY THE AFTERNOON...AN
AREA OF LOW PRESSURE ALONG WITH A UPPER TROUGH WILL MOVE INTO
WESTERN MINNESOTA AND WILL EFFECT THE REGION SATURDAY NIGHT.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 242 AM CDT FRI JUL 25 2014
THE MODELS ARE IN PRETTY GOOD AGREEMENT THROUGH MUCH OF THE
PERIOD. AN UPPER TROUGH OVER SOUTHERN MANITOBA SATURDAY EVENING
WILL DROP INTO NORTHERN MINNESOTA BY 12Z SUN...THEN CONTINUE INTO
SOUTHERN WISCONSIN BY SUNDAY EVENING. A SURFACE LOW/TROUGH AXIS
WILL BE ASSOCIATED WITH THIS UPPER WAVE. SHOWERS AND A FEW
THUNDERSTORMS WILL INCREASE IN COVERAGE SATURDAY NIGHT INTO SUNDAY
MORNING...THEN DECREASE FROM NORTH TO SOUTH SUNDAY
AFTERNOON/EVENING. SUNDAY NIGHT SHOULD BE DRY. WE HAVE THE HIGHEST
POPS OVER THE EASTERN PORTION OF THE NORTHLAND LATE SATURDAY NIGHT
INTO SUNDAY MORNING.
HIGH PRESSURE WILL THEN LEAD TO MAINLY DRY CONDITIONS SUNDAY NIGHT
INTO MONDAY NIGHT. THERE MAY BE A FEW SHOWERS TUESDAY INTO WEDNESDAY
OVER THE EASTERN HALF OF THE NORTHLAND WITH A SERIES OF SHORTWAVES
MOVING THROUGH IN THE NORTHERLY FLOW ALOFT. WE ALSO HAVE A SMALL
CHANCE FOR SHOWERS/STORMS THURSDAY FOR MOST AREAS.
THE PERIOD WILL START OUT WITH BELOW NORMAL TEMPERATURES
SUNDAY...WITH HIGHS IN THE MID SIXTIES TO LOWER SEVENTIES.
TEMPERATURES WILL THEN MODERATE THROUGH THE REST OF THE
PERIOD...REACHING THE UPPER SEVENTIES TO LOWER EIGHTIES BY THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 632 AM CDT FRI JUL 25 2014
SHOWERS AND A FEW THUNDERSTORMS WERE MOVING THROUGH
CENTRAL/EASTERN PORTIONS OF THE NORTHLAND EARLY THIS MORNING. WE
EXPECT A LULL IN COVERAGE TO DEVELOP THIS MORNING...THEN
ADDITIONAL DEVELOPMENT THIS AFTERNOON AHEAD OF THE SURFACE
BOUNDARY THAT WILL ONLY MOVE SLOWLY FROM WESTERN MINNESOTA EARLY
THIS AFTERNOON TOWARD THE EAST.
AN AREA OF MVFR/IFR CEILINGS HAVE DEVELOPED OVER WEST CENTRAL
MINNESOTA INTO CENTRAL MINNESOTA. THE RAP IS SUGGESTS THESE
CEILINGS WILL SPREAD NORTH AND EAST TODAY. HOWEVER...THE COVERAGE
CURRENTLY IS NOT AS GREAT AS THE RAP SUGGESTS. WE FEEL MOST
CONFIDENT KBRD WILL SEE THE LOWER CEILINGS AND ADDED A TEMPO GROUP
FOR THE REST OF THE TAF SITES BY MID TO LATE MORNING.
THE COVERAGE OF THE PRECIPITATION WILL DIMINISH THIS EVENING AND
SOME FOG WILL BE POSSIBLE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 74 59 82 59 / 50 40 50 50
INL 75 57 81 56 / 40 40 50 60
BRD 79 58 84 60 / 60 20 30 40
HYR 75 62 85 58 / 60 30 30 50
ASX 75 61 81 57 / 40 40 40 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...STEWART
SHORT TERM...STEWART
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
632 AM CDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 430 AM CDT FRI JUL 25 2014
UPDATED TO INCREASE POPS ACROSS PORTIONS OF THE FORECAST AREA. AREA
OF SHOWERS AND THUNDERSTORMS MOVING ACROSS THOSE AREAS THIS
MORNING. THIS PRECIPITATION WILL END BY MID-MORNING. REST OF FCST UNCHANGED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 242 AM CDT FRI JUL 25 2014
SHORT TERM CONCERN IS PRECIPITATION CHANCE TODAY AND TONIGHT.
CURRENT SURFACE ANALYSIS INDICATES RAIN SHOWERS NORTH OF THE IRON
RANGE AND IN THE ARROWHEAD. THESE SHOWERS ARE ASSOCIATED WITH A WEAK
SHORTWAVE MOVING THROUGH THE AREA. THEY WILL CONTINUE MOVE
SOUTHEAST AND SLOWLY DISSIPATE EARLY THIS MORNING. THERE IS AN
AREA OF THUNDERSTORMS ALONG THE ND/SD/WRN MN BORDER MOVING ESE.
THE AREA HAS DECREASED IN INTENSITY OVER THE PAST HOUR. THE
NORTHERN EDGE OF THE PRECIPITATION MAY CLIP CASS AND CROW WING
COUNTIES THIS MORNING. A WEAK SURFACE TROUGH WILL MOVE THROUGH MN
TODAY AND NW WI TONIGHT. IT WILL BRING ANOTHER ROUND OF SHOWERS
AND THUNDERSTORMS. THERE WILL BE SOME INCREASED INSTABILITY WITH
THE TROUGH THIS AFTERNOON AND EVENING. MUCAPES ARE
1500-2000...SHEAR IS 20-40...AND SOME SUN TODAY. SPC HAS THE
FORECAST AREA IN A 5% PROBABILITY FOR WIND/HAIL WITH THE MARGINAL
INSTABILITY.
AN AREA OF WEAK HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE
WEST LATE THIS EVENING. THIS WILL END THE THREAT FOR PRECIPITATION
FOR LATE FRIDAY NIGHT AND SATURDAY. HOWEVER..BY THE AFTERNOON...AN
AREA OF LOW PRESSURE ALONG WITH A UPPER TROUGH WILL MOVE INTO
WESTERN MINNESOTA AND WILL EFFECT THE REGION SATURDAY NIGHT.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 242 AM CDT FRI JUL 25 2014
THE MODELS ARE IN PRETTY GOOD AGREEMENT THROUGH MUCH OF THE
PERIOD. AN UPPER TROUGH OVER SOUTHERN MANITOBA SATURDAY EVENING
WILL DROP INTO NORTHERN MINNESOTA BY 12Z SUN...THEN CONTINUE INTO
SOUTHERN WISCONSIN BY SUNDAY EVENING. A SURFACE LOW/TROUGH AXIS
WILL BE ASSOCIATED WITH THIS UPPER WAVE. SHOWERS AND A FEW
THUNDERSTORMS WILL INCREASE IN COVERAGE SATURDAY NIGHT INTO SUNDAY
MORNING...THEN DECREASE FROM NORTH TO SOUTH SUNDAY
AFTERNOON/EVENING. SUNDAY NIGHT SHOULD BE DRY. WE HAVE THE HIGHEST
POPS OVER THE EASTERN PORTION OF THE NORTHLAND LATE SATURDAY NIGHT
INTO SUNDAY MORNING.
HIGH PRESSURE WILL THEN LEAD TO MAINLY DRY CONDITIONS SUNDAY NIGHT
INTO MONDAY NIGHT. THERE MAY BE A FEW SHOWERS TUESDAY INTO WEDNESDAY
OVER THE EASTERN HALF OF THE NORTHLAND WITH A SERIES OF SHORTWAVES
MOVING THROUGH IN THE NORTHERLY FLOW ALOFT. WE ALSO HAVE A SMALL
CHANCE FOR SHOWERS/STORMS THURSDAY FOR MOST AREAS.
THE PERIOD WILL START OUT WITH BELOW NORMAL TEMPERATURES
SUNDAY...WITH HIGHS IN THE MID SIXTIES TO LOWER SEVENTIES.
TEMPERATURES WILL THEN MODERATE THROUGH THE REST OF THE
PERIOD...REACHING THE UPPER SEVENTIES TO LOWER EIGHTIES BY THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 632 AM CDT FRI JUL 25 2014
SHOWERS AND A FEW THUNDERSTORMS WERE MOVING THROUGH
CENTRAL/EASTERN PORTIONS OF THE NORTHLAND EARLY THIS MORNING. WE
EXPECT A LULL IN COVERAGE TO DEVELOP THIS MORNING...THEN
ADDITIONAL DEVELOPMENT THIS AFTERNOON AHEAD OF THE SURFACE
BOUNDARY THAT WILL ONLY MOVE SLOWLY FROM WESTERN MINNESOTA EARLY
THIS AFTERNOON TOWARD THE EAST.
AN AREA OF MVFR/IFR CEILINGS HAVE DEVELOPED OVER WEST CENTRAL
MINNESOTA INTO CENTRAL MINNESOTA. THE RAP IS SUGGESTS THESE
CEILINGS WILL SPREAD NORTH AND EAST TODAY. HOWEVER...THE COVERAGE
CURRENTLY IS NOT AS GREAT AS THE RAP SUGGESTS. WE FEEL MOST
CONFIDENT KBRD WILL SEE THE LOWER CEILINGS AND ADDED A TEMPO GROUP
FOR THE REST OF THE TAF SITES BY MID TO LATE MORNING.
THE COVERAGE OF THE PRECIPITATION WILL DIMINISH THIS EVENING AND
SOME FOG WILL BE POSSIBLE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 74 59 82 59 / 50 40 20 50
INL 75 57 81 56 / 40 40 40 60
BRD 79 58 84 60 / 40 20 10 40
HYR 75 62 85 58 / 50 30 10 50
ASX 75 61 81 57 / 40 40 20 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...STEWART
SHORT TERM...STEWART
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
602 AM CDT FRI JUL 25 2014
.UPDATED FOR 12Z AVIATION DISCUSSION...
ISSUED AT 556 AM CDT FRI JUL 25 2014
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT FRI JUL 25 2014
EARLY MORNING THUNDERSTORMS CONTINUED TO DEVELOP ACROSS THE REGION
THIS MORNING FUELED BY THE VEERING WINDS ASSOCIATED WITH THE THETA_E
ADVECTION IN CONNECTION WITH THE LOW LEVEL JET. OVER THE NEXT FEW
HOURS THIS 40KT JET WILL BECOME MORE FOCUSED ACROSS SOUTHERN...AND
EVENTUALLY SOUTHEASTERN MN. AS A RESULT PRECIPITATION WILL CONTINUE
TO DEVELOP FOR THE NEXT FEW HOURS...BUT SHOULD GRADUALLY WANE
SHORTLY AFTER SUNSET AS IT ENTERS WESTERN WI.
EARLIER RUNS OF THE RAP MISSED THE PRECIP THAT DEVELOPED IN
NORTHEAST SD...SO IT IS NO SURPRISE THAT HIGHRES MODELS HAVE BEEN
STRUGGLING TO GET A HANDLE ON THE TWO AREAS OF PRECIP THAT DEVELOPED
EARLIER. AS A RESULT MOST OF THE RUNS HAVE BEEN ALL BUT DISCARDED.
THE 25.06HRRR HAS FINALLY CAUGHT UP AND IT SUPPORTS THE IDEA OF
CONTINUED CONVECTION THIS MORNING...BUT WITH A WEAKENING TREND AFTER
11Z. THE SEVERE WEATHER THREAT IS VERY LOW GIVEN THE DEEP STABLE
LAYER BENEATH THE ELEVATED CAPE...AND ONLY MARGINAL 30-35KTS OF
EFFECTIVE SHEAR.
LOOKING AHEAD...SKIES SHOULD CLEAR BEHIND THE MORNING PRECIP
YIELDING ANOTHER MUGGY AFTERNOON AS DEWPOINTS CLIMB BACK TO NEAR
70F. INCREASED TEMPS SLIGHTLY ACROSS WEST OF I35...AND RAISED
DEWPOINTS AS WELL. OVERNIGHT NORTHWESTERLY WINDS WILL PUSH A COLD
FRONT THROUGH THE REGION SENDING DEWPOINTS BACK INTO THE UPPER 50S
BY SATURDAY MORNING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 AM CDT FRI JUL 25 2014
THE WEEKEND STARTS OUT ON A MILD NOTE...AS THE AREA REMAINS
SANDWICHED BETWEEN A SOUTHERN CONUS RIDGE TO THE SOUTH...AND A
MID LEVEL LOW TO THE NORTH IN SASKATCHEWAN/MANITOBA. THE RESULT WILL
BE SLIGHTLY WARMER THAN NORMAL HIGHS IN THE MID 80S ON
SATURDAY...FOLLOWED BY INCREASING PRECIPITATION CHANCES INTO
SUNDAY AS THE AFOREMENTIONED LOW DROPS SOUTH-SOUTHEAST FROM
SOUTHERN MANITOBA. AS IS COMMON WITH THESE TYPES OF
LOWS...PRECIPITATION CHANCES APPEAR THE HIGHEST FROM CENTRAL MN
INTO WI...WHERE FORCING/MOISTURE IS DEEPER. EXPECT SHOWERS WITH
ISOLATED THUNDERSTORMS ON SUNDAY...PARTICULARLY DURING THE AFTERNOON
HOURS AS DIURNAL HEATING AIDS DESTABILIZATION.
NEXT WEEK STARTS OUT ON A DRY AND MILD NOTE AS THE WEEKEND LOW
SHIFTS SOUTHEAST AND A BROAD SURFACE RIDGE BUILDS ACROSS THE
CENTRAL CONUS. THE LOCAL AREA REMAINS CRAMMED BETWEEN WESTERN
RIDGING AND EASTERN TROUGHING AT THE MID TO UPPER LEVELS OF THE
ATMOSPHERE...YIELDING COOLER THAN NORMAL HIGHS FROM MONDAY THROUGH
WEDNESDAY MOSTLY IN THE 70S...AND LOWS IN THE 50S.
THURSDAY AND FRIDAY BRING THE NEXT CHANCE FOR MEASURABLE
PRECIPITATION AS SHORTWAVE ENERGY BEGINS TO TRICKLE SOUTH ON THE
WESTERN PERIPHERY OF THE EASTERN CONUS TROUGH. CHANCES ARE NOT
HIGH AT THIS POINT GIVEN MODEST FORCING AND MOISTURE...BUT
SUFFICIENT FOR THE INCLUSION OF 20-30 POPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 556 AM CDT FRI JUL 25 2014
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO WEAKEN AS THEM MOVE
ACROSS THE REGION THIS MORNING. FORECAST GUIDANCE WANTS TO SHOW A
FEW LOW CLOUDS ACROSS NORTHWEST MN LATER TODAY...BUT CONFIDENCE IS
TOO LOW TO INCLUDE IN THE TAF AT THIS TIME. LOOKING AHEAD...FOG
SHOULD DEVELOP AHEAD OF A COLD FRONT THAT IS FORECAST TO SLOWLY
MOVE ACROSS THE REGION LATER TODAY. THE BEST CHANCE FOR FOG IS
ACROSS THE EAST AT KRNH AND KEAU.
KMSP...
PRECIP WILL BE OUT OF THE REGION BEFORE 12Z...WITH VFR CONDITIONS
EXPECTED THROUGHOUT THE PERIOD. CHANCE FOR FOG IS LOW AT KMSP.
/OUTLOOK FOR KMSP/
SUN...VFR WITH MVFR/SHRA POSSIBLE. WINDS NW AT 10G15KTS.
MON...VFR. WINDS N AT 5KTS.
TUE...VFR. WINDS N AT 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...LS
AVIATION...JRB
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
950 AM CDT Fri Jul 25 2014
.UPDATE:
Issued at 950 AM CDT Fri Jul 25 2014
Complex of TSRA continues to maintain itself rather well on its
backside over northeast MO and eastern IA, where lo level jet and
better instability are feeding it. An isolated threat for large
hail exists, but should decrease heading deeper into the morning.
Overall health of TSRA complex should also begin to fail as we
head into the afternoon hours, with strengthening cap of warm air
to the west and weakening lo level jet. This rain should have a
somewhat easier time of advecting in IL versus MO and updated the
forecast accordingly, although will no doubt need to tweak
expected coverage over the next couple hours.
Also adjusted temps further down in IL, where readings should stay
below 80F, but enough recovery expected in the west and south to
maintain previous forecast.
TES
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 330 AM CDT Fri Jul 25 2014
Convective trends and the extent of pops are the biggest forecast
challenge today. Thunderstorms have blossomed within the last
several hours across central Iowa at the terminus of a stout
southwesterly LLJ, and along the eastern periphery of elevated
instability, deeper moisture and steep mid level lapse rates.
Short range guidance shows the LLJ slowly veering this morning,
providing favorable moisture transport and forcing as the flow
aloft and northwestely deep layer shear steer the activity east
and southeastward. The HRRR runs since 01Z have been very emphatic
supporting this scenario bringing showers and thunderstorms into
northeast Missouri and west central Illinois. I have increased
pops into the likely range in this area tapered to slight chances
just north of interstate 70. Believe that most of this activity
will be east of the MS river by early afternoon and exiting the
CWA shortly thereafter. This activity will likely delay/impeed the
northward retreat of the warm front, however in central MO there
should be no issue where highs will be around 90.
Glass
.LONG TERM: (Tonight through Thursday)
Issued at 330 AM CDT Fri Jul 25 2014
The warm front should have exited the entire CWA by early evening
while the upstream cold frontal system will be slowly advancing
and stretching from the upper MS valley into the central Plains.
High heights aloft and warm mid level temperatures should suppress
any surface-based storm development within the large warm sector
spanning the CWA, however the area will remain subject to an
elevated shower and thunderstorm threat. While there is no defined
focus for thunderstorms, a westerly LLJ will be poised across the
area in conjunction with steep mid level lapse rates and good
elevated instability supporting a least a chance pop. These same
unfocused conditions will exist on Saturday morning. The set-up
should improve on Saturday afternoon. Strong surface heating
should yield temperatures well into the 90s with dew points in the
70s. This will result in afternoon heat indices in the 100-104 degree
range, just below advisory criteria. We will need to monitor this
closely as just a bit higher dew points and/or temperatures and a
heat advisory will be warranted. The aforementioned conditions along
with the presence of steep mid level lapse rates will yield very
unstable conditions during the afternoon/evening. There are
indications that the combo of heating and a disturbance in the
west northwest flow aloft should sufficiently weaken the cap
allowing for robust thunderstorm development along the west-east
oriented front stretching in the vicinity of far northern MO
through central IL into the OH valley. How far west development
occurs is uncertain but height falls/cooling aloft on Saturday
night could aid this process. Deep layer shear and instability is
quite favorable for organized severe with damaging winds the most
apparent severe threat at this time. I have some low pops on
Sunday ahead of the advancing front, but the overall threat of
precipitation will be lower as compared to the Saturday night.
Cooler and drier air will advect in earnest into the area on Sunday
night with a large surface high settling into the Nation`s
midsection on Monday. An unseasonably deep upper trof over eastern
NOAM through the first part of next week will keep the large
surface high in control and allow for another period of below
average temperatures as we exit July and head into August.
Glass
&&
.AVIATION: (For the 12z TAFs through 12z Saturday Morning)
Issued at 519 AM CDT Fri Jul 25 2014
Cluster of thunderstorms over southeastern Iowa will continue
tracking southeastward and will arrive at the KUIN TAF site by
around 12z. VSBYS may fall to high end of MVFR range as the
storms pass, but cigs will likely remain AOA 6K feet. Storms will
move into more stable atmosphere as they approach the St. Louis
metro TAF sites, and most model output suggests little or no
precip there. With that in mind, will keep all St. Louis area TAFS
dry. South winds will increase this afternoon.
Specifics for KSTL: Thunderstorms approaching from the northwest
should dissipate before moving into KSTL TAF site as they move
into more stable air. High clouds will remain through
at least midday...with south winds increasing to 10 to 14 mph by
afternoon.
Browning
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
533 AM CDT Fri Jul 25 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 330 AM CDT Fri Jul 25 2014
Convective trends and the extent of pops are the biggest forecast
challenge today. Thunderstorms have blossomed within the last
several hours across central Iowa at the terminus of a stout
southwesterly LLJ, and along the eastern periphery of elevated
instability, deeper moisture and steep mid level lapse rates.
Short range guidance shows the LLJ slowly veering this morning,
providing favorable moisture transport and forcing as the flow
aloft and northwestely deep layer shear steer the activity east
and southeastward. The HRRR runs since 01Z have been very emphatic
supporting this scenario bringing showers and thunderstorms into
northeast Missouri and west central Illinois. I have increased
pops into the likely range in this area tapered to slight chances
just north of interstate 70. Believe that most of this activity
will be east of the MS river by early afternoon and exiting the
CWA shortly thereafter. This activity will likely delay/impeed the
northward retreat of the warm front, however in central MO there
should be no issue where highs will be around 90.
Glass
.LONG TERM: (Tonight through Thursday)
Issued at 330 AM CDT Fri Jul 25 2014
The warm front should have exited the entire CWA by early evening
while the upstream cold frontal system will be slowly advancing
and stretching from the upper MS valley into the central Plains.
High heights aloft and warm mid level temperatures should suppress
any surface-based storm development within the large warm sector
spanning the CWA, however the area will remain subject to an
elevated shower and thunderstorm threat. While there is no defined
focus for thunderstorms, a westerly LLJ will be poised across the
area in conjunction with steep mid level lapse rates and good
elevated instability supporting a least a chance pop. These same
unfocused conditions will exist on Saturday morning. The set-up
should improve on Saturday afternoon. Strong surface heating
should yield temperatures well into the 90s with dew points in the
70s. This will result in afternoon heat indices in the 100-104 degree
range, just below advisory criteria. We will need to monitor this
closely as just a bit higher dew points and/or temperatures and a
heat advisory will be warranted. The aforementioned conditions along
with the presence of steep mid level lapse rates will yield very
unstable conditions during the afternoon/evening. There are
indications that the combo of heating and a disturbance in the
west northwest flow aloft should sufficiently weaken the cap
allowing for robust thunderstorm development along the west-east
oriented front stretching in the vicinity of far northern MO
through central IL into the OH valley. How far west development
occurs is uncertain but height falls/cooling aloft on Saturday
night could aid this process. Deep layer shear and instability is
quite favorable for organized severe with damaging winds the most
apparent severe threat at this time. I have some low pops on
Sunday ahead of the advancing front, but the overall threat of
precipitation will be lower as compared to the Saturday night.
Cooler and drier air will advect in earnest into the area on Sunday
night with a large surface high settling into the Nation`s
midsection on Monday. An unseasonably deep upper trof over eastern
NOAM through the first part of next week will keep the large
surface high in control and allow for another period of below
average temperatures as we exit July and head into August.
Glass
&&
.AVIATION: (For the 12z TAFs through 12z Saturday Morning)
Issued at 519 AM CDT Fri Jul 25 2014
Cluster of thunderstorms over southeastern Iowa will continue
tracking southeastward and will arrive at the KUIN TAF site by
around 12z. VSBYS may fall to high end of MVFR range as the
storms pass, but cigs will likely remain AOA 6K feet. Storms will
move into more stable atmosphere as they approach the St. Louis
metro TAF sites, and most model output suggests little or no
precip there. With that in mind, will keep all St. Louis area TAFS
dry. South winds will increase this afternoon.
Specifics for KSTL: Thunderstorms approaching from the northwest
should dissipate before moving into KSTL TAF site as they move
into more stable air. High clouds will remain through
at least midday...with south winds increasing to 10 to 14 mph by
afternoon.
Browning
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1014 AM EDT FRI JUL 25 2014
.SYNOPSIS...
A STALLED FRONT WILL BECOME INTERTWINED WITH THE SEABREEZE TODAY.
THE FRONT WILL LIFT NORTH AND DISSIPATE TONIGHT. HIGH PRESSURE WILL
FOLLOW AND BRING HOT...HUMID AND SULTRY CONDITIONS THIS WEEKEND AND
ON MONDAY. THE NEXT COLD FRONT WILL DROP ACROSS THE AREA TUESDAY. IN
ITS WAKE...COOLER AND DRIER CONDITIONS WILL OVERSPREAD THE AREA FOR
THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM FRIDAY...THE COLD FRONT HAS PUSHED SURPRISINGLY FAR TO
THE SOUTH AND IS EASILY VISIBLE ON SATELLITE IMAGERY AS A WALL OF
LOW STRATUS AND EVEN SOME PATCHY FOG. THIS BOUNDARY HAS PUSHED INTO
MYRTLE BEACH...CONWAY...AND KINGSTREE SC IN THE PAST HOUR AND SHOULD
STALL SHORTLY IN THE VICINITY OF PAWLEYS ISLAND...ANDREWS AND
GREELEYVILLE SC. MODELS SHOW THIS FRONT RETURNING NORTHWARD THIS
AFTERNOON AS HIGH PRESSURE MOVES OFF THE MID-ATLANTIC COAST...ALSO
HELPED BY A WEAK SEABREEZE CIRCULATION THAT SHOULD ADD SOME
NORTHBOUND MOMENTUM TO OUR LOW-LEVEL WINDS.
DIFFERENTIAL HEATING ALONG THE FRONT SHOULD HELP INTENSIFY LOW-LEVEL
CONVERGENCE BY EARLY AFTERNOON...AND THE LATEST FEW HRRR MODEL RUNS
PLUS LAST NIGHT`S NSSL WRF SHOW THUNDERSTORMS INITIATING ACROSS
GEORGETOWN AND HORRY COUNTIES EARLY THIS AFTERNOON. ALTHOUGH CELL
MOTION SHOULD BE EASTWARD AT 10-15 MPH...STORMS WILL INGEST THE
DRIER AIR ALOFT IN DOWNDRAFTS CREATING A COMPLEX NETWORK OF
BOUNDARIES THAT WILL ULTIMATELY DETERMINE STORM MOTION AND FUTURE
DEVELOPMENT. MY HIGHEST POPS (60-70 PERCENT) ARE CENTERED ACROSS
SOUTHERN HORRY COUNTY...WITH LOWER POPS (30-50 PERCENT) EXTENDING
INTO THE NORTHERN PEE DEE REGION AND SE NORTH CAROLINA.
WATER VAPOR IMAGERY SHOWS THE MID LEVELS HAVE DRIED SINCE YESTERDAY
EVENING. THE 12Z MHX SOUNDING WAS DOWN TO 1.75 INCHES PRECIPITABLE
WATER WITH AROUND 1.9 INCHES ON THE CHS SOUNDING. THE BULK OF THIS
DRYING IS ABOVE THE 700 MB LAYER. 0-6 KM BULK SHEAR HAS DECREASED
FROM YESTERDAY AS HAS OVERALL INSTABILITY VALUES WHICH ARE
ANTICIPATED TO AVERAGE 1500-2500 J/KG TODAY VERSUS 3000-4000 J/KG
YESTERDAY.
I HAVE BUMPED DOWN TEMPERATURES BY A COUPLE DEGREES WHERE CLOUDS
THIS MORNING PLUS ONSHORE WINDS THIS AFTERNOON WILL HELP HOLD DOWN
HEATING. OTHERWISE NO SIGNIFICANT CHANGES ARE PLANNED.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...MODELS CONTINUE WITH THE ONGOING LONGWAVE
UPPER PATTERN THIS PERIOD...WITH TROFFING ALOFT ACROSS THE
EASTERN 1/3RD OF THE U.S. AND RIDGING ALOFT FOR THE WESTERN 2/3RDS
OF THE U.S. THE UPPER TROF AXIS...NOT AS AMPLIFIED AS WAS EARLIER
IN THE WEEK...IS PROGGED TO A POSITION JUST OFF THE CAROLINA
COASTS...BASICALLY ALONG THE EASTERN SEABOARD. AT THE SFC...MODELS
INDICATE THE SFC FRONT WILL DECAY ACROSS THE AREA ON SATURDAY.
THIS WILL LEAVE THE FA UNDER WEAK RIDGING FROM THE ATL
WATERS...AND THE FORMATION OF THE PIEDMONT TROF ACROSS THE CENTRAL
CAROLINAS DURING SATURDAY.
FOR SUNDAY THRU SUNDAY NIGHT...THE MODELS REMAIN IN GOOD
AGREEMENT WITH THE AMPLIFICATION OF BOTH THE UPPER TROF
OVERHEAD...AND THE UPPER RIDGING THAT IS CURRENTLY AFFECTING THE
WESTERN 2/3RDS OF THE U.S. A S/W TROF IS PROGGED TO DIVE OUT OF
CENTRAL CANADA EARLY SUNDAY...AND BASICALLY AID IN THE
AMPLIFICATION PROCESS OF THE FLOW ALOFT ACROSS THE CONTERMINOUS
U.S. AT THE SFC...THE WEAK RIDGING FROM OFF THE COAST WILL GET
SHUNTED SOUTH OF THE AREA. THE PIEDMONT SFC TROF WILL GAIN SOME
STRENGTH AS MODELS CONTINUE WITH THE TIGHTENING OF THE GRADIENT
ASSOCIATED WITH THE PIEDMONT TROF.
THIS PERIOD WILL BE HIGHLIGHTED BY THE 3HS...HAZY HOT AND HUMID.
VERY LITTLE IN THE WAY OF CONVECTION IS EXPECTED EXCEPT FOR ISOLATED
CHANCES ALONG THE SEA BREEZE BOUNDARY...AND ANY CONVECTION THAT
DRIFTS TO THE FA AFTER FIRING UP ALONG THE PIEDMONT TROF. THUS
20-30 POPS ARE THE HIGHEST WILL GO THIS PERIOD. OVERALL...WARMER
TEMPS ALOFT AS WELL AS SUBSIDENCE ALOFT...WILL BOTH AID IN KEEPING
A LID ON CONVECTION THIS WEEKEND. VARIOUS MODEL MOS GUIDANCE DOES
PAINT WIDESPREAD 90+ DEGREE TEMPS FOR SATURDAY...AND EVEN HOTTER
ON SUNDAY. HAVE GONE ALONG WITH THESE NUMBERS ESPECIALLY WITH THE
DECENT W-NW DOWNSLOPE FLOW ALOFT. IN FACT...HEAT ADVISORY CRITERIA
WILL LIKELY BE MET ON SUNDAY WITH HIGHS WELL INTO THE 90S ALONG
WITH HUMIDITY LEVELS HAVING INCHED BACK UPWARDS. THUS THE 2
COMBINED PROVIDE FORECAST HEAT INDICES REACHING A WIDESPREAD
104-106 DEGREES ACROSS THE FA.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM THURSDAY...MID LEVEL TROUGH WILL DOMINATE MUCH OF THE
PERIOD KEEPING TEMPERATURES ACROSS THE REGION BELOW CLIMO. THE
EXCEPTION WILL BE ON SUN WITH MID LEVEL RIDGE TO THE WEST
EXTENDING EAST. 850 TEMPS WILL FLIRT WITH 20-22C WHICH SHOULD
PRODUCE HIGHS IN THE MID TO UPPER 90S. DESPITE THE HOT TEMPS DO NOT
THINK THERE WILL BE MUCH CONVECTION AROUND. WESTERLY MID LEVEL FLOW
AND SUBSIDENCE ON THE RIDGES PERIPHERY WILL KEEP MID LEVELS DRY.
CANNOT RULE OUT ISOLATED CONVECTION...ESPECIALLY LATER IN THE DAY
ASSOCIATED WITH THE PIEDMONT TROUGH BUT SEE NO REASON TO GO ABOVE
INHERITED SILENT POP.
COLD FRONT MOVES INTO THE AREA LATE MON...PUSHED BY IMPRESSIVE MID
LEVEL TROUGH. DOES NOT LOOK LIKE MON WILL BE AS HOT AS SUN GIVEN
INCREASED MID LEVEL MOISTURE AND MORE WIDESPREAD CONVECTION LATER IN
THE DAY...JUST AHEAD OF THE FRONT. SHOULD THE FRONT BE DELAYED A BIT
MON COULD END UP AS HOT AS SUN GIVEN 850 TEMPS HANGING IN THE LOW
20C RANGE FOR MUCH OF THE DAY. LATER MON INTO TUE WILL BE THE MOST
ACTIVE PART OF THE PERIOD CONVECTIVELY SPEAKING AND WILL MAINTAIN
INHERITED HIGH CHC POP.
MID LEVEL TROUGH AXIS WILL REMAIN WEST OF THE AREA THROUGH THE
PERIOD WITH THE FRONT STALLING NOT TOO FAR OFF THE COAST. INITIALLY
MID LEVELS ARE DRY BUT INCREASING MOISTURE ALOFT WILL RESULT IN A
SLOW INCREASE IN POP THROUGH THE MIDDLE OF NEXT WEEK. TEMPS WILL RUN
A LITTLE BELOW CLIMO LATE IN THE PERIOD.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...AREAS OF MVFR/IFR FOR THE NEXT HOUR OR TWO DUE TO
ADVECTION FOG AND LOW CIGS ASSOCIATED WITH A FRONTAL BOUNDARY.
CONDITIONS IMPROVE TO VFR BY LATE MORNING. SHRA/TSRA POSSIBLE THIS
AFTERNOON...ESPECIALLY ALONG THE COAST.
IFR DUE TO LOW CIGS AND FOG IS CURRENTLY BEING OBSERVED AT
KILM/KFLO/KLBT. EXPECT THIS TO IMPROVE TO MVFR AND THEN VFR
WITHIN THE NEXT COUPLE OF HOURS AND FOR NORTHERLY WINDS TO
INCREASE TO AOB 5 KTS. INTO THIS AFTERNOON...WINDS WILL BECOME
SOUTHEAST AOB 10 KTS ALONG THE COAST WHILE LIGHT WINDS REMAIN
INLAND. CHANCES WILL INCREASE FOR ISOLATED TO SCATTERED
TSRA/SHRA...ESPECIALLY ALONG THE COAST...AS THE SEA BREEZE AND
FRONTAL BOUNDARY INTERACT. ANY CONVECTION WILL TAPER OFF LATER
TONIGHT...AND OVERNIGHT INTO THE EARLY MORNING HOURS WINDS WILL
BECOME LIGHT AND VARIABLE WITH MVFR/IFR IS POSSIBLE DUE TO FOG AT
ALL SITES.
EXTENDED OUTLOOK...SHOWERS/TSTMS/TEMPO MVFR POSSIBLE SUNDAY AND
MONDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM FRIDAY...THE COLD FRONT HAS PUSHED ALL THE WAY DOWN TO
MYRTLE BEACH THIS MORNING WITH NORTH WINDS GUSTING AS HIGH AS 15
KNOTS ACROSS THE WATERS OF SOUTHEASTERN NORTH CAROLINA. THE FRONT
SHOULD STALL SOON NEAR MURRELLS INLET OR PAWLEYS ISLAND...THEN WILL
RETURN NORTHWARD THIS AFTERNOON. THE BIGGEST CHANGE TO THE FORECAST
REGARDS WIND DIRECTION THIS MORNING WHICH ARE MAINLY NORTH TO
NORTHEAST BEHIND THE FRONT...BUT REMAIN SOUTHWESTERLY ACROSS THE
GEORGETOWN COUNTY WATERS. LATEST MODELS SHOW A SLOWER VEERING OF THE
SURFACE WINDS NORTH OF THE FRONT THIS AFTERNOON...WITH DIRECTIONS
REMAINING EAST FOR A LONGER PERIOD OF TIME THAN EARLIER THOUGH.
FORTUNATELY WIND SPEEDS SHOULD REMAIN FAIRLY LIGHT.
SEAS ARE RUNNING 2-3 FT CURRENTLY...AND WITH NO SIGNIFICANT INCREASE
EXPECTED IN WIND SPEEDS THROUGH THE DAY I HAVE TRIMMED ABOUT A FOOT
OFF THE PREVIOUS FORECAST. A 9-SECOND SOUTHEAST SWELL CONTINUES.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...FOR SATURDAY...THE AREA WATERS WILL BE
UNDER THE INFLUENCE OF A DECAYING FRONTAL BOUNDARY...RESULTING IN
MAINLY A VARIABLE WIND DIRECTION FOR MUCH OF THE DAY...AND WITH
THE LACK OF ANY GRADIENT...SPEEDS WILL GENERALLY BE 10 KT OR LESS.
FOR SUNDAY...THE AMPLIFYING FLOW ALOFT WILL RESULT IN A
STRENGTHENING SFC PIEDMONT TROF ACROSS THE CENTRAL CAROLINAS AND
THE RIDGING FROM THE BERMUDA HIGH BEING SHUNTED WELL SOUTH OF THE
AREA WATERS. THIS WILL PRODUCE A TIGHTENING SFC PG ACROSS THE
CAROLINAS INCLUDING THE COASTAL WATERS. THE SFC PRESSURE PATTERN
WILL YIELD A SFC SW-WSW WIND DIRECTION...WITH INCREASING SPEEDS
SUNDAY INTO SUNDAY NIGHT. SCEC AND/OR SCA CONDITIONS WILL LIKELY
BE MET SUNDAY AFTERNOON AND/OR NIGHT.
SIGNIFICANT SEAS WILL BE AT THEIR EBB DURING SATURDAY WITH AN ESE-
SE 1-3 FOOT GROUND SWELL DOMINATING THE WATERS. THE AFTN/EVENING SEA
BREEZE CIRCULATION WILL ADD SOME WIND CHOP NEAR SHORE. FOR
SUNDAY...LOOK FOR WIND DRIVEN WAVES TO STEADILY INCREASE IN BOTH
HEIGHT AND PERIODS...AND WILL LIKELY BE THE DOMINANT PLAYER IN THE
SIGNIFICANT SEAS FORMULA. WILL ADVERTISE 6 FOOTERS ACROSS THE
LOCAL WATERS LATE SUNDAY AFTERNOON BUT MORE LIKE SUNDAY NIGHT.
.LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 PM THURSDAY...MODEST SW FLOW ON SUN WILL INCREASE INTO MON
AS GRADIENT TIGHTENS AHEAD OF ADVANCING COLD FRONT. SPEEDS LATER SUN
MAY APPROACH SCEC THRESHOLDS AS PIEDMONT TROUGH STRENGTHENS. SCA
HEADLINES SEEM CERTAIN FOR AT LEAST MON AND POSSIBLY SUN NIGHT AS
PROLONGED STRONG SOUTHWEST FLOW BUILDS SEAS TO 4 TO 6 FT. FRONT
MOVES ACROSS THE WATERS MON NIGHT WITH NORTHERLY FLOW DEVELOPING.
GRADIENT RELAXES BEHIND THE FRONT AND SPEEDS WILL DROP UNDER 10 KT
BY MIDDAY TUE. FRONT ENDS UP STALLED JUST EAST OF THE WATERS WITH
THE PROXIMITY TO THE FRONTAL ZONE KEEPING GRADIENT WEAK AND WINDS
LIGHT AND VARIABLE. SEAS WILL DROP TO 3 TO 4 FT BEHIND THE FRONT AND
BELOW 3 FT BY THE END OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...DCH
LONG TERM...III
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
938 AM CDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 938 AM CDT FRI JUL 25 2014
AREA OF LOW CLOUDS REMAINED ALONG OR EAST OF
CARRINGTON/BISMARCK/LINTON/FORT YATES LINE...AND THIS CLOUD SHIELD
SHOULD CONTINUE MOVING EAST AND/OR ERODING FROM THE WEST AS DRY
HIGH PRESSURE PUSHES INTO THE REGION WITH WEST/NORTHWEST WINDS.
REST OF FORECAST FOR TODAY ON TRACK.
UPDATE ISSUED AT 636 AM CDT FRI JUL 25 2014
NARROW BAND OF CLOUDS REMAIN ACROSS CENTRAL NORTH DAKOTA AND THESE
HAVE BEEN ERODING THROUGH THE MORNING. SKIES WILL CONTINUE TO
CLEAR ACROSS THE REGION. KEPT ISOLATED SHOWERS SOUTH CENTRAL FOR A
FEW HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT FRI JUL 25 2014
THE LATEST SURFACE ANALYSIS PLACES A COLD FRONT FROM NEAR SHERWOOD
TO JUST EAST OF MINOT AND SOUTH TO NEAR LINTON. WEAK PRESSURE
FALLS CONTINUE AHEAD OF THE FRONT WITH AN AREA OF SHOWERS AND
ISOLATED THUNDERSTORMS MOSTLY OVER NORTH CENTRAL NORTH DAKOTA.
THE FOG/STRATUS LOOP INDICATES POCKETS OF LOWER CLOUDS BEHIND THE
FRONT BUT STEADILY MOVING EAST. THE HRRR CEILING FORECAST HAS A
GOOD HANDLE ON THE CURRENT SITUATION AND ALSO PROGRESSIVELY MOVES
THE BACK EDGE OF THE LOWER CLOUDS THROUGH THE JAMES RIVER VALLEY
BY 14Z. WATER VAPOR IMAGERY LOOP SHOWS AN UPPER LOW SPINNING OVER
SOUTHEASTERN ALBERTA WITH A DRIER WESTERLY FLOW INTO NORTH DAKOTA.
ALBEIT A FEW DISTURBANCES ARE EMBEDDED WITHIN THE FLOW BUT THESE
ARE NOT EXPECTED TO HAVE MUCH OF AN IMPACT DURING THE SHORT TERM
PERIOD. THUS EXPECT A MOSTLY SUNNY SKY WITH BREEZY CONDITIONS AS
WESTERLY WINDS WILL RANGE BETWEEN 15 AND 25 MPH. HIGHS TODAY WILL
RANGE FROM THE UPPER 70S NORTH TO LOWER 80S SOUTH. AN AREA OF
SHOWERS WILL DEVELOP OVER SOUTH DAKOTA TONIGHT AND REMAIN SOUTH OF
NORTH DAKOTA/SOUTH DAKOTA BORDER. LATE FRIDAY NIGHT THERE WILL
ALSO BE AN AREA OF SHOWERS SLIDING INTO SOUTHERN SASKATCHEWAN AND
MANITOBA...BUT THESE SHOWERS WILL REMAIN NORTH OF THE BORDER
THROUGH 12Z SATURDAY. THUS DRY CONDITIONS WILL PREVAIL THROUGH
FRIDAY NIGHT. OVERNIGHT LOWS FRIDAY NIGHT WILL BE IN THE 50S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 335 AM CDT FRI JUL 25 2014
THE MAIN FEATURE OF THIS FORECAST PERIOD WILL BE THE UPPER LEVEL
LOW FORECAST BY MODELS TO MOVE SOUTHEAST FROM SASK THROUGH
MINNESOTA EVENTUALLY MERGING WITH A LONGWAVE TROUGH OVER THE
EASTERN US. AS THIS PROCESS TAKES PLACE THE LOW WILL USHER IN
COOLER SURFACE TEMPERATURES AND MORE STABLE AIR. SCATTERED SHOWERS
AND POSSIBLE AN ISOLATED THUNDERSTORM ARE FORECAST FOR THE NORTH
AND EAST ON SATURDAY. SUNDAY THROUGH TUESDAY WILL BE DRY AND
COOLER WITH HIGHS AS COOL AS THE UPPER 60S ACROSS THE TURTLE
MOUNTAINS SUNDAY...AND 70S SOUTH AND WEST. EVENTUALLY A HIGH
AMPLITUDE FLOW DEVELOPS ACROSS NORTH AMERICA WITH A LONGWAVE
TROUGH OVER THE EASTERN US AND A RIDGE OVER THE WEST BY THE MIDDLE
OF NEXT WEEK. THIS LEAVES THE NORTHERN PLAINS IN A SLIGHTLY
ANTICYCLONIC NORTHWEST FLOW REGIME THAT SHOULD SUPPRESS MUCH OF
THE CONVECTION WEDNESDAY AND THURSDAY WITH JUST ISOLATED
THUNDERSTORMS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 636 AM CDT FRI JUL 25 2014
A NARROW LINE OF LOW VFR/MVFR CIGS WILL HOVER FROM KMOT TO KBIS
THROUGH 13Z FRIDAY...AND OVER KJMS UNTIL 16Z FRIDAY. OTHERWISE SKC
WILL DOMINATE THE TERMINALS THROUGH THE TAF PERIOD. WESTERLY WINDS
GUSTING TO 25KT WILL SUBSIDE BY 02Z SATURDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...KS
LONG TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
640 AM CDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 636 AM CDT FRI JUL 25 2014
NARROW BAND OF CLOUDS REMAIN ACROSS CENTRAL NORTH DAKOTA AND THESE
HAVE BEEN ERODING THROUGH THE MORNING. SKIES WILL CONTINUE TO
CLEAR ACROSS THE REGION. KEPT ISOLATED SHOWERS SOUTH CENTRAL FOR A
FEW HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT FRI JUL 25 2014
THE LATEST SURFACE ANALYSIS PLACES A COLD FRONT FROM NEAR SHERWOOD
TO JUST EAST OF MINOT AND SOUTH TO NEAR LINTON. WEAK PRESSURE
FALLS CONTINUE AHEAD OF THE FRONT WITH AN AREA OF SHOWERS AND
ISOLATED THUNDERSTORMS MOSTLY OVER NORTH CENTRAL NORTH DAKOTA.
THE FOG/STRATUS LOOP INDICATES POCKETS OF LOWER CLOUDS BEHIND THE
FRONT BUT STEADILY MOVING EAST. THE HRRR CEILING FORECAST HAS A
GOOD HANDLE ON THE CURRENT SITUATION AND ALSO PROGRESSIVELY MOVES
THE BACK EDGE OF THE LOWER CLOUDS THROUGH THE JAMES RIVER VALLEY
BY 14Z. WATER VAPOR IMAGERY LOOP SHOWS AN UPPER LOW SPINNING OVER
SOUTHEASTERN ALBERTA WITH A DRIER WESTERLY FLOW INTO NORTH DAKOTA.
ALBEIT A FEW DISTURBANCES ARE EMBEDDED WITHIN THE FLOW BUT THESE
ARE NOT EXPECTED TO HAVE MUCH OF AN IMPACT DURING THE SHORT TERM
PERIOD. THUS EXPECT A MOSTLY SUNNY SKY WITH BREEZY CONDITIONS AS
WESTERLY WINDS WILL RANGE BETWEEN 15 AND 25 MPH. HIGHS TODAY WILL
RANGE FROM THE UPPER 70S NORTH TO LOWER 80S SOUTH. AN AREA OF
SHOWERS WILL DEVELOP OVER SOUTH DAKOTA TONIGHT AND REMAIN SOUTH OF
NORTH DAKOTA/SOUTH DAKOTA BORDER. LATE FRIDAY NIGHT THERE WILL
ALSO BE AN AREA OF SHOWERS SLIDING INTO SOUTHERN SASKATCHEWAN AND
MANITOBA...BUT THESE SHOWERS WILL REMAIN NORTH OF THE BORDER
THROUGH 12Z SATURDAY. THUS DRY CONDITIONS WILL PREVAIL THROUGH
FRIDAY NIGHT. OVERNIGHT LOWS FRIDAY NIGHT WILL BE IN THE 50S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 335 AM CDT FRI JUL 25 2014
THE MAIN FEATURE OF THIS FORECAST PERIOD WILL BE THE UPPER LEVEL
LOW FORECAST BY MODELS TO MOVE SOUTHEAST FROM SASK THROUGH
MINNESOTA EVENTUALLY MERGING WITH A LONGWAVE TROUGH OVER THE
EASTERN US. AS THIS PROCESS TAKES PLACE THE LOW WILL USHER IN
COOLER SURFACE TEMPERATURES AND MORE STABLE AIR. SCATTERED SHOWERS
AND POSSIBLE AN ISOLATED THUNDERSTORM ARE FORECAST FOR THE NORTH
AND EAST ON SATURDAY. SUNDAY THROUGH TUESDAY WILL BE DRY AND
COOLER WITH HIGHS AS COOL AS THE UPPER 60S ACROSS THE TURTLE
MOUNTAINS SUNDAY...AND 70S SOUTH AND WEST. EVENTUALLY A HIGH
AMPLITUDE FLOW DEVELOPS ACROSS NORTH AMERICA WITH A LONGWAVE
TROUGH OVER THE EASTERN US AND A RIDGE OVER THE WEST BY THE MIDDLE
OF NEXT WEEK. THIS LEAVES THE NORTHERN PLAINS IN A SLIGHTLY
ANTICYCLONIC NORTHWEST FLOW REGIME THAT SHOULD SUPPRESS MUCH OF
THE CONVECTION WEDNESDAY AND THURSDAY WITH JUST ISOLATED
THUNDERSTORMS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 636 AM CDT FRI JUL 25 2014
A NARROW LINE OF LOW VFR/MVFR CIGS WILL HOVER FROM KMOT TO KBIS
THROUGH 13Z FRIDAY...AND OVER KJMS UNTIL 16Z FRIDAY. OTHERWISE SKC
WILL DOMINATE THE TERMINALS THROUGH THE TAF PERIOD. WESTERLY WINDS
GUSTING TO 25KT WILL SUBSIDE BY 02Z SATURDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...KS
LONG TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1148 AM EDT FRI JUL 25 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN BEHIND A DEPARTING COLD FRONT ON FRIDAY
LASTING THROUGH THE MAJORITY OF THE WEEKEND. ANOTHER COLD FRONT IS
EXPECTED TO REACH THE AREA FROM THE NORTHWEST ON MONDAY MORNING AND
INTO MONDAY AFTERNOON POTENTIALLY LEADING TO SCATTERED
THUNDERSTORMS. HIGH PRESSURE WILL ONCE AGAIN REGAIN CONTROL ON
TUESDAY LASTING THROUGH THE REMAINDER OF THE WORK WEEK WITH ONLY
MINIMAL PRECIPITATION THREATS BY WEEKS END.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 11 AM...ALTHOUGH THE WEAK FRONT HAS SAGGED INTO THE SC
MIDLANDS AND CENTRAL GA THIS MORNING...A MOIST E/NE FLOW NORTH OF
THE BOUNDARY IS RESULTING IN AREAS OF LOW STRATUS AND STRATOCU
ACROSS THE AREA. THIS SHOULD CONTINUE TO LIFT/EVOLVE INTO A FAIRLY
EXTENSIVE AFTERNOON CUMULUS FIELD. THE PRIMARY CONCERN FOR THIS
PERIOD WILL BE WHETHER A FEW OF THESE CUMULUS CLOUDS CAN DEVELOP
INTO THUNDERSTORMS THIS AFTERNOON. THE DIFFERENCE BETWEEN FORECAST
RAP AND NAM SOUNDINGS IS QUITE STRIKING...AS THE RAP MAINTAINS A
RATHER FORMIDABLE CAP ACROSS THE AREA THROUGH THE AFTERNOON...WHILE
THE NAM TRIES TO ELIMINATE IT. ALTHOUGH DEWPOINTS WILL BE A LITTLE
LOWER THAN TYPICAL OF THIS TIME OF YEAR...THEY SHOULD STILL BE HIGH
ENOUGH TO YIELD MODEST AMOUNTS OF CAPE THIS AFTERNOON. THUS...IF THE
CAP DOES INDEED ERODE...IT SEEMS REASONABLE THAT A FEW SHOWERS/TSRA
WILL DEVELOP ACROSS THE HIGH TERRAIN...AS IS INDICATED IN THE
CURRENT FORECAST. THE ONLY REAL CHANGE OF NOTE WILL BE TO INCLUDE A
SLIGHT CHANCE POP NEARER THE FRONT ACROSS THE FAR SOUTHERN PIEDMONT
AREAS. OTHERWISE...MAX TEMPS SHOULD BE ABOUT A CATEGORY BELOW CLIMO
OWING TO THE COOL E/NE FLOW AND CONSIDERABLE CUMULUS COVER.
AS OF 640 AM...LOW CLOUDS SPREADING IN FROM THE EAST OR ALREADY IN
PLACE ACROSS THE MTNS SHUD LIFT OR SCATTER OUT BY NOON. OTHERWISE...
GOING FCST STILL LOOKS ON TRACK. UPDATES MAINLY FOR CURRENT
CONDITIONS.
AS OF 305 AM...SLOW MOVING COLD FRONT KEEPING ENUF LOW LEVEL
CONVERGENCE ACROSS THE SRN UPSTATE TO BREAK THE CAP AND PRODUCE
ISOLATED SHRA. THESE SHUD END OR MOVE SOUTH OF THE AREA BY DAYBREAK
AS THE FRONT MOVES OUT OF THE AREA.
ALTHOUGH THE FRONT MOVES SOUTH OF THE AREA...GUIDANCE IS NEARLY
UNANIMOUS KEEPING LOW LEVEL MOISTURE ACROSS THE AREA. IN ADDITION...
LOW LEVEL FLOW BECOMES SELY LEADING TO WEAK UPSLOPE FLOW. THIS IS
FORECAST TO PROVIDE ENUF LIFT TO TAP THE ELEVATED INSTABILITY AND
PRODUCE ISOLATED TO SCT CONVECTION ALONG THE BLUE RIDGE AND WEST
ACROSS THE MTNS. GIVEN THE MDL SUPPORT...HAVE CHANGED THE FORECAST
TO INCLUDE POP IN THIS AREA. THERE MAY ALSO BE SOME CONVECTION
ACROSS THE FAR SRN CWFA AS THAT AREA WILL BE CLOSE TO THE FRONT.
HOWEVER...BEST CHC WILL BE SOUTH OF THE CWFA. CLOUDS WILL LINGER
THRU THE MORNING ACROSS MUCH OF THE NRN AND ERN CWFA...BEFORE MIXING
OUT BY AFTERNOON. THIS AND THE COOLER AIR MASS BEHIND THE FRONT WILL
LEAD TO HIGHS A LITTLE BELOW NORMAL.
CONVECTION SHUD DISSIPATE DURING THE EVENING WITH LOSS OF HEATING.
HOWEVER...CANNOT RULE OUT SOME LINGERING SHRA OVER THE BLUE RIDGE
LATE INTO THE EVENING OR EARLY OVERNIGHT BEFORE THE LOW LEVEL FLOW
BECOMES SWLY. LOWS SHUD BE NEAR NORMAL.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 230 AM EDT FRIDAY...THE SHORT TERM PERIOD INITIALIZES SATURDAY
MORNING WITH REMNANT FRONT WELL TO THE SOUTHEAST ALONG THE
CAROLINA/GEORGIA COASTLINE. SURFACE HIGH PRESSURE WILL QUICKLY
BUILD UNDER RISING HEIGHTS ALOFT. DESPITE WEAK LEE TROF DEVELOPING
JUST EAST OF THE FORECAST AREA POTENTIALLY PROVIDING A FOCUS FOR
AFTERNOON CONVECTION...SOUNDINGS INDICATE A SUBSTANTIAL LOW/MID
LEVEL CAP IN PLACE. NOT EXPECTING ANY POTENTIAL UPDRAFTS TO BREAK
THROUGH THE DEEP INHIBITION THEREFORE KEPT THE FORECAST DRY FOR
SATURDAY.
ALSO KEPT FORECAST DRY THROUGH SUNDAY MORNING AS UPPER HEIGHTS ARE
SLOW TO FALL DUE TO APPROACHING UPPER TROF AND ASSOCIATED SURFACE
COLD FRONT. STILL THINK AREA OF GREATEST LIFT AND LOWEST INHIBITION
WILL REMAIN TIED TO LEE TROF REDEVELOPMENT EAST OF THE I77 CORRIDOR
THEREFORE CONTINUE WITH DRY FORECAST FOR THE PIEDMONT REGION THROUGH
THE AFTERNOON. FURTHER WEST...HEIGHTS WILL BEGIN TO FALL RAPIDLY AS
UPPER SHORT WAVE AND ASSOCIATED MOISTURE ADVECT INTO THE
CENTRAL/SOUTHERN APPS. MODELS TEND TO AGREE ON AT LEAST SOME
PRECIPITATION PUSHING INTO THE NORTHERN MOUNTAINS BY MID/LATE
AFTERNOON ON SUNDAY...WITH CHANCES INCREASING AHEAD OF THE
APPROACHING FRONT THROUGH THE OVERNIGHT. THEREFORE...SOLID CHANCE
POPS ARE FEATURED SUNDAY EVENING ALONG THE HIGHER TERRAIN OF NC
INCREASING TO NEAR LIKELY POPS BY MONDAY MORNING NEAR THE TN
BORDER. ELSEWHERE POPS TAPER DOWN SHARPLY TO SLIGHT CHANCE LEVELS
OVER THE NC/SC FOOTHILLS AND WESTERN MOST AREAS OF THE PIEDMONT.
TEMPERATURES THROUGH THE SHORT TERM PERIOD WILL GRADUALLY WARM AS
SOUTHERLY FLOW RAMPS UP AHEAD OF APPROACHING SURFACE TROF.
EXPECTING HIGHS ON BOTH SATURDAY AND SUNDAY TO SURGE TO ABOVE NORMAL
LEVELS WITH MID 90S POSSIBLE FOR SOUTHERN PORTIONS OF THE FORECAST
AREA ON SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 315 AM EDT FRIDAY...THE EXTENDED RANGE PERIOD WILL BEGIN WITH
A RATHER ACTIVE PATTERN ON MONDAY MORNING. STRONG HEIGHT FALLS WILL
BE ADVECTING IN FROM THE WEST AS A COLD FRONT STRETCHES ALONG THE
APPALACHIAN CHAIN FROM A PARENT SURFACE CYCLONE ACROSS THE EASTERN
GREAT LAKES. POPS WILL INITIALIZE AT HIGH END CHANCE LEVELS ACROSS
THE HIGHER TERRAIN AS THE PRE-FRONTAL ACTIVITY PUSHES INTO THE REGION
AROUND OR JUST BEFORE DAYBREAK MONDAY. THE ENTIRE COMPLEX WILL
CONTINUE ADVECTING EAST THROUGH THE MORNING AND EARLY AFTERNOON
HOURS ALLOWING FOR SOME DIURNAL DESTABILIZATION AHEAD ACROSS THE
NC/SC PIEDMONT REGIONS. THERE IS STILL SOME UNCERTAINTY REGARDING
OVERALL MAGNITUDE OF INSTABILITY THAT WILL BUILD AHEAD OF THE FRONT
AS ABUNDANT SKY COVER WILL WORK TO LIMIT HEATING. THAT
SAID...MODEST WARM SECTOR ALREADY IN PLACE WILL NOT NEED MUCH
HEATING FOR LAPSE RATES TO SUPPORT SUBSTANTIAL LOW LEVEL LIFT.
ALOFT DRIER AIR WILL BE ADVECTING IN AS STRONG WNW FLOW ASSOCIATED
WITH TROF AXIS PUSHES INTO THE REGION. THIS WILL ALLOW MID LEVEL
LAPSE RATES TO STEEPEN...POTENTIALLY LEADING TO A FAIRLY UNSTABLE
PROFILE. SPEAKING OF...LATEST GFS FORECAST SOUNDINGS INDICATE
NEARLY 1500J/KG SBCAPE AND LONG STRAIGHT HODOGRAPHS PRODUCING DEEP
LAYER SHEAR IN EXCESS OF 35KTS SUGGESTING MULTICELL STRONG/SEVERE
THUNDERSTORMS. ALL THAT SAID...THERE IS STILL PLENTY OF TIME FOR THE
PATTERN TO CHANGE SLIGHTLY WHICH COULD SUBSTANTIALLY ALTER THE
OUTCOME. THUS...DUE TO RANGE IN THE FORECAST...KEPT POPS CAPPED AT
CHANCE LEVELS FOR THE ENTIRE REGION ON MONDAY AFTERNOON.
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION BEHIND THE FRONT
FOR TUESDAY AND WEDNESDAY LEADING TO LOWER PRECIPITATION CHANCES
DESPITE PERSISTENT UPPER TROF REMAINING NEARLY STATIONARY. FORECAST
WILL FEATURE SLIGHT CHANCE POPS ACROSS THE HIGH TERRAIN THROUGH
WEDNESDAY MORNING AMIDST STRONG NW FLOW. THE SURFACE RIDGE REMAINS
DOMINATE THROUGH THE REMAINDER OF THE PERIOD AS IT REPOSITIONS
ITSELF TO THE NORTHEAST AND EXTENDS IN A WEDGE LIKE PATTERN ALONG
THE LEE SIDE OF THE APPALACHIANS BY THURSDAY. SURFACE FLOW WILL
SHIFT TO MORE OF AN EAST TO SOUTHEAST COMPONENT LEADING TO POTENTIAL
UPSLOPE/UPGLIDE PRECIPITATION INTO FRIDAY. THUS CHANCE LEVEL POPS
ARE ONCE AGAIN FEATURED THROUGH THE REMAINDER OF THE FORECAST ALONG
THE HIGH TERRAIN WITH SLIGHT CHANCE POPS HIGHLIGHTED ELSEWHERE.
TEMPERATURES WILL GRADUALLY COOL BEHIND THE FROPA ON MONDAY WITH
HIGHS TOPPING OUT NEARLY A CATEGORY BELOW NORMAL BY THURSDAY FOR
SOME LOCATIONS.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
AT KCLT...IFR STRATUS HAS SPREAD ACROSS THE AIRFIELD AND WILL
CONTINUE THRU MID-MORNING WHEN A SLOW RISE TO LOW VFR BY 18Z
DEVELOPS. THAT SAID...MOISTURE IS SHALLOW AND CIGS COULD SCATTER OUT
BEFORE LIFTING. FEW TO SCT LOW VFR CLOUDS EXPECTED THRU THE EVENING
AND OVERNIGHT. NELY WIND BECOMES ENE THIS AFTERNOON AND EVENING THEN
CALM OVERNIGHT. RIGHT NOW...DO NOT EXPECT ANY RESTRICTIONS
OVERNIGHT.
ELSEWHERE...LOW STRATUS IS MAKING A RUN FROM THE EAST AT THE NON MTN
SITES. LOW VFR CIGS HAVE DEVELOPED AND MVFR OR EVEN THE IFR DECK
COULD DEVELOP. IF SO...SHUD BE A RELATIVELY QUICK RETURN TO VFR...
GENERALLY BEFORE NOON. THEN VFR EXPECTED THRU THE REST OF THE
PERIOD. NELY WIND BECOMES ELY OR SELY BY LATE AFTERNOON WITH
GENERALLY CALM WIND OVERNIGHT. KAVL WILL SEE MVFR OR IFR THIS
MORNING WITH LOW VFR DEVELOPING BY NOON. NLY WIND BECOMES SLY FOR
THE AFTERNOON...THEN CALM OVERNIGHT. ISOLATED CONVECTION WILL
DEVELOP ACROSS THE MTNS...BUT CHC TOO LOW FOR TAF INCLUSION. KAVL
COULD SEE RESTRICTIONS FROM FOG TOWARD DAYBREAK SAT.
OUTLOOK...SAT THROUGH SUNDAY MORNING SHOULD BE QUIET AND VFR...
EXCEPT FOR THE MTN VALLEYS WHERE EARLY MORNING FOG MAY OCCUR. SCT
THUNDERSTORMS MAY RETURN TO THE FORECAST AREA FOR SUNDAY
AFTERNOON...THOUGH MORE LIKELY MON...AS ANOTHER COLD FRONT
APPROACHES AND THEN MOVES THROUGH THE AREA BY MON NIGHT.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-15Z
KCLT HIGH 88% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 97% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 88% HIGH 100% HIGH 89% HIGH 90%
KHKY HIGH 89% HIGH 100% HIGH 100% HIGH 87%
KGMU HIGH 98% HIGH 97% HIGH 100% HIGH 100%
KAND HIGH 88% HIGH 100% HIGH 100% HIGH 93%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...CDG
NEAR TERM...JDL/RWH
SHORT TERM...CDG
LONG TERM...CDG
AVIATION...RWH
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1011 AM CDT FRI JUL 25 2014
.UPDATE...
CHANCE FOR SHOWERS AND A FEW STORMS WILL CONTINUE THROUGH THE DAY
TODAY AS WARM ADVECTION LINGERS ACROSS SOUTHERN WISCONSIN. BEST
CHANCE LOOKS TO BE FROM LATE THIS MORNING UNTIL AROUND 4 PM OR SO
GIVEN LATEST RAP AND HRRR. MIGHT HAVE TO LOWER AFTERNOON HIGHS A
BIT GIVEN EXTENSIVE CLOUD COVER ACROSS THE REGION.
&&
.AVIATION/18Z TAFS/...
CHANCE FOR SHOWERS AND A FEW STORMS WILL CONTINUE THROUGH THE DAY
TODAY AS WARM ADVECTION LINGERS ACROSS SOUTHERN WISCONSIN. BEST
CHANCE LOOKS TO BE FROM LATE THIS MORNING UNTIL AROUND 4 PM OR SO
GIVEN LATEST RAP AND HRRR. THE CHANCE FOR SHOWERS/STORMS WILL
PERSIST INTO TONIGHT AS THE TROUGH AXIS AND SFC FRONT APPROACH.
VFR CONDITIONS WILL GENERALLY PERSIST THROUGH SATURDAY...THROUGH
UPSTREAM OBS AND MODEL SOUNDINGS SHOW THE POTENTIAL FOR SOME MVFR
CIGS AT TIMES.
&&
.PREV DISCUSSION... /ISSUED 558 AM CDT FRI JUL 25 2014/
UPDATE...
CHANGED WORDING IN FORECAST TO ISOLATED/SCATTERED AS OBS UNDER UPSTREAM
RETURNS APPROACHING PORTIONS OF EAST CENTRAL WI ARE REPORTING
SPRINKLES/LIGHT RAIN SHOWERS WITH TRACE AMOUNTS. A FEW GROUND
STROKES WEST OF MADISON SO ISOLATED/SCT THUNDERSTORMS THERE.
ALSO EXPANDED POPS FOR LATER THIS MORNING AS LINE OF CONVECTION
MOVING INTO WEST CENTRAL WI TRACKING MORE WITH THE 850-300 MB MEAN
WIND ALMOST DUE EAST VERSUS THE ANTICIPATED SOUTH-SOUTHEAST PER
CORFIDI VECTORS.
PREV DISCUSSION... /ISSUED 345 AM CDT FRI JUL 25 2014/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
POCKETS OF CONVECTION EXTENDING FROM NORTHEAST SOUTH DAKOTA AND
SW MN INTO ERN NEBRASKA DEVELOPING ALONG LEADING EDGE OF SFC TO
850 MB MOISTURE PLUME IN REGION OF DEEP MOISTURE CONVERGENCE AND
THETA-E ADVECTION AHEAD OF 850 MB LOW/SFC LOW WITH MOST UNSTABLE
CAPE OF 1000 J/KG OR HIGHER.
THESE POCKETS OF CONVECTION ARE SETTING UP TO THE SW AND WEST OF
STRONG 850 MB FRONTOGENETIC RESPONSE TO THE LOW LEVEL JET
IMPINGING ON 850 MB BAROCLINIC ZONE STRETCHING ACROSS W CENTRAL TO
SOUTH CENTRAL MN INTO NE IOWA.
HI RES/RAPID UPDATE MODELS CATCHING ON TO LACK OF MOISTURE AND
INSTABILITY OVER WI AND KEEPING PCPN OUT OF CWA UNTIL AFTER
12Z...WITH A FEW ACCAS SPRINKLES POSSIBLE BEFORE THEN.
MODELS AGREE THAT AREAL COVERAGE AND AMOUNT OF PRECIPITATION WILL
DIMINISH AS WEAKENING FORCING AND OMEGA PUSHES ACROSS STATE WITH
DIURNALLY WEAKENING LLJ THIS MORNING/EARLY AFTERNOON. WILL KEEP
POPS IN CHANCE/SCATTERED CATEGORY AND MAINLY SHOWERS WITH ONLY A
SLGT CHANCE OF THUNDER DUE TO CAPPING AND MARGINAL MID LEVEL
LAPSE RATES.
LOOKING FOR A BREAK IN THE PCPN MID AFTERNOON...THEN REDEVELOPING
AS LOW LEVEL JET BEGINS TO STRENGTHEN LATE THIS AFTERNOON AND
EVENING. CAP AT 700 MB ERODES EARLY TO MID EVENING...BUT STILL
SOME QUESTION TO AMOUNT OF SURFACE BASED CAPE. HOWEVER DECENT
ELEVATED CAPE FOR THUNDERSTORMS. 0 TO 6KM SHEAR SUFFICIENT FOR
SUSTAINED UPDRAFTS...AND WITH STEEPENING MID-LEVEL LAPSE
RATES...SOME HAIL NOT OUT OF THE QUESTION THOUGH PROBABILITY FOR
SEVERE HAIL IS LOW. PW/S REACH NEAR 2 INCHES BY 06Z SO HEAVY
DOWNPOURS POSSIBLE... ESPECIALLY IN THE FAR SOUTH AND SOUTHEAST.
SHORT TERM...SATURDAY THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE
IS MEDIUM.
MODELS SHOWING QPF ASSOCIATED WITH MAIN PUSH OF WARM AIR ADVECTION
MOVING OFF TO THE EAST ON SATURDAY. AREA FORECAST SOUNDINGS
SHOWING CAPPED AIRMASS OVER SOUTHERN WISCONSIN...WITH NOT MUCH
FORCING FOR UPWARD VERTICAL MOTION SEEN. THUS...KEPT SATURDAY DRY
ACROSS THE AREA. WARM AND HUMID CONDITIONS WILL PREVAIL...WITH
HIGHS REACHING THE MID 80S IN MOST AREAS PER 925 MB TEMPERATURE
FIELDS.
KEPT LOW POPS IN THE WESTERN COUNTIES SATURDAY NIGHT...WITH
APPROACH OF 500 MB SHORTWAVE TROUGH. HOWEVER...THIS WILL STILL
HAVE TO CONTEND WITH FAIRLY STRONG CAP OVER THE AREA. SO...MOST OF
THE NIGHT MAY REMAIN DRY IN THIS AREA.
MODELS THEN BRING COLD FRONT SOUTHEASTWARD THROUGH THE AREA SUNDAY
MORNING INTO EARLY AFTERNOON...WITH TRAILING 500 MB SHORTWAVE
TROUGH MOVING THROUGH DURING THE AFTERNOON AND EARLY EVENING. AREA
FORECAST SOUNDINGS DO MIX OUT CAP DURING THE DAY...THOUGH IT MAY
BE AFTER THE FRONTAL PASSAGE IN NORTHERN PORTIONS OF THE AREA.
KEPT LIKELY POPS FOR THUNDERSTORMS MOST OF SUNDAY...THOUGH BEST
CHANCES WILL BE IN THE MORNING BEFORE FRONTAL PASSAGE. SOME
QUESTION AS TO HOW MUCH MEAN LAYER CAPE WILL EXIST BEFORE FRONT
MOVES THROUGH. THIS WILL DETERMINE IF THERE WILL BE A HAIL
RISK...GIVEN THE STRONG DEEP LAYER SHEAR.
COLD AIR ADVECTION SUNDAY NIGHT SHOULD BRING IN COOLER AND LESS
HUMID AIR...AND END THE POPS DURING THE EVENING HOURS.
LONG TERM...MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE IS
MEDIUM.
GFS/ECMWF SHOWING HIGH PRESSURE SLIDE SOUTHEAST FROM THE NORTHERN
PLAINS INTO THE MIDDLE MISSISSIPPI RIVER VALLEY REGION MONDAY INTO
WEDNESDAY. 500 MB TROUGH REMAINS ANCHORED OVER THE NORTHEAST AND
MIDDLE ATLANTIC STATES...WITH NORTH NORTHWEST FLOW OVER THE
WESTERN GREAT LAKES REGION.
VARIOUS 500 MB VORTICITY MAXIMA MOVE THROUGH THE AREA DURING THIS
TIME. ENOUGH MOISTURE LINGERS TO CARRY LOWER END POPS FOR MOST OF
THIS PERIOD. CONTINUED POPS THROUGH THURSDAY USING CONSENSUS
POPS...AS OVERALL PATTERN LINGERS. TEMPERATURES SHOULD BE PLEASANT
FOR THIS TIME OF YEAR.
AVIATION/12Z TAFS/...
AGAIN WATCHING CURRENT ACCAS SHOWER/THUNDERSTORM DEVELOPMENT FOR
ADJUSTMENTS TO TIMING INTO TAF SITES. STILL LOOKS LIKE KMSN AND
POINTS WEST HAVE THE BEST CHANCE TO SEE ISOLATED TO SCATTERED THUNDERSTORMS
WITH VERY BRIEF MVFR VSBYS THIS MORNING...WITH ONLY AN ISOLATED
LIGHT VFR SHOWER/SPRINKLES AT EASTERN TAF SITES. BETTER CHANCE
FOR THUNDER COMES LATE THIS AFTERNOON/EVENING TO ALL SITES. WILL
TRY TO HONE IN ON MOST LIKELY TIMES AT EACH SITE...BUT EVEN VARIED
SHORT-TERM MODEL DIFFERENCES HANDLING CURRENT PCPN...AS WELL AS
TIMING/AMOUNTS LATER TODAY AND TONIGHT. WILL CARRY PREVAILING VFR
WITH MVFR CIGS/VSBYS WITH THUNDER.
MARINE...
SOUTH TO SOUTHWEST WINDS REMAIN LOW ENOUGH TO NOT CAUSE ANY
WIND/WAVE ISSUES INTO SUNDAY EVENING. LOOKING AT THUNDERSTORM
CHANCES INCREASING LATE THIS AFTERNOON INTO TONIGHT...AND AGAIN ON
SUNDAY.
NORTH WINDS TO INCREASE SUNDAY NIGHT INTO MONDAY BRINGING
WINDS/WAVES TOWARD SMALL CRAFT ADVISORY LEVELS...AS WELL AS A
BEACH HAZARD POTENTIAL ON MONDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...DDV
TODAY/TONIGHT AND AVIATION/MARINE...REM
SATURDAY THROUGH THURSDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
651 AM CDT FRI JUL 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 303 AM CDT FRI JUL 25 2014
LATEST MOSAIC RADAR SHOWING A LINE OF SHOWERS AND THUNDERSTORMS
DEVELOPING FROM WEST CENTRAL MINNESOTA INTO CENTRAL IOWA EARLY
THIS MORNING. THE SHOWERS AND THUNDERSTORMS IS ON THE NOSE OF THE
LOW LEVEL JET/MOISTURE TRANSPORT AND CONVERGENCE IN THE 925-850MB
LAYER PER THE LATEST 25.03 RAP AND 25.00Z GFS/NAM.
THE 25.00Z NAM/GFS AND THE 25.03Z RAP INDICATE THE NOSE OF LOW LEVEL
JET/MOISTURE TRANSPORT AND CONVERGENCE WILL BE POINTED DIRECTLY INTO
MAINLY THE SOUTHERN FORECAST AREA THROUGH 18Z TODAY. HOWEVER...THE
MODELS SHOW THE CORFIDI VECTORS/UPWIND PROPAGATION VECTORS TO MOVE
THE SHOWERS AND THUNDERSTORMS SOUTH TO SOUTHEAST AND IMPACT MAINLY
THE SOUTHERN FORECAST AREA TODAY. THIS IS EVIDENT WITH MOVEMENT OF
THE THUNDERSTORMS EARLY THIS MORNING PER THE LATEST MOSAIC RADAR.
AT THIS TIME...SEVERE WEATHER THREAT LOOKS TO BE MINIMAL WITH THE
THUNDERSTORMS...AS THE LATEST 25.00Z NAM AND 25.03Z RAP SHOW 0-6KM
MOST UNSTABLE CAPE LESS THAN 1000 J/KG AND THE BETTER ELEVATED
INSTABILITY TO BE WEST OF THE DEVELOPING THUNDERSTORM
ACTIVITY/NOSE OF THE LOW LEVEL JET/MOISTURE CONVERGENCE. THE
MODELS SHOW PRECIPITABLE WATERS APPROACHING 1.5 TO 2 INCHES LATE
THIS MORNING. SOME OF THE THUNDERSTORMS COULD PRODUCE LOCAL HEAVY
RAINFALL.
THE LOW LEVEL JET/MOISTURE CONVERGENCE WEAKENS AND MOVES EAST OF
THE FORECAST AREA THIS AFTERNOON AND EVENING AND WILL ALLOW FOR
SKIES AND PRECIPITATION CHANCES TO DIMINISH WEST TO EAST ACROSS
THE FORECAST AREA.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 303 AM CDT FRI JUL 25 2014
NEXT CONCERN IS CLOSED UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN
AND ALBERTA SLOWLY MEANDERS OVER THE UPPER GREAT LAKES REGION
SATURDAY NIGHT INTO SUNDAY. THE 25.00Z GFS/NAM SHOW MUCH STRONGER
AND DEEPER QG FORCING IN ASSOCIATION WITH THE UPPER LEVEL LOW. BEST
FORCING INCREASES OVER THE NORTHERN PORTIONS OF FORECAST AREA LATE
SATURDAY NIGHT INTO SUNDAY...HENCE THE BETTER PRECIPITATION CHANCES.
THE NAM/GFS BUFKIT SOUNDINGS INDICATE WEAK ELEVATED CAPE MAINLY
ABOVE 800MB BY 18Z SUNDAY AND 0-6KM MOST UNSTABLE CAPE OF 500-1000
J/KG EAST OF THE MISSISSIPPI RIVER. WILL CONTINUE TO MENTION
ISOLATED THUNDERSTORMS SATURDAY NIGHT INTO SUNDAY.
SUNDAY NIGHT THROUGH THURSDAY...NORTHERLY FLOW DEVELOPS OVER THE
UPPER GREAT LAKES REGION PER LATEST 25.00Z GFS/ECMWF/GEM. MAIN
CONCERN IS TIMING OF THE WEAK SHORTWAVE TROUGHS EMBEDDED IN THE
NORTHERLY FLOW ALOFT AND PRODUCE SMALL PRECIPITATION CHANCES ACROSS
PARTS OF THE FORECAST AREA TUESDAY...WEDNESDAY NIGHT INTO
THURSDAY. TEMPERATURES MONDAY THROUGH THURSDAY WILL CONTINUE TO BE
UNSEASONABLY COOL ACROSS FORECAST AREA...AS THE 25.00Z GEFS
INDICATE 850MB TEMPERATURE ANOMALIES IN THE MINUS 0.5 TO MINUS 1.5
DEGREES CELSIUS RANGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 650 AM CDT FRI JUL 25 2014
A SHORT WAVE TROUGH WILL PRODUCE SHOWERS AND THUNDERSTORMS AT BOTH
TAF SITES THIS MORNING. THIS PRECIPITATION MAY BRIEFLY REDUCE
VISIBILITIES AND CEILINGS TO MVFR. THE HRRR HAS BEEN HANDLING
THIS PRECIPITATION WELL EARLY THIS MORNING...SO FOLLOWED IT WHEN
MAKING THE TAFS. WITH THIS IN MIND...THE PRECIPITATION WILL END AT
KRST BY 25.14Z AND AT KLSE BY 25.15Z.
FOR TONIGHT...THE LAMP GUIDANCE IS SUGGESTING THAT FOG WILL REDUCE
VISIBILITIES TO MVFR AT KRST AFTER 26.06Z...AND LESS THAN A MILE
AT KLSE AFTER 26.08Z. I AM A BIT SKEPTICAL OF THIS SINCE THERE HAS
BEEN VERY LITTLE FOG OVER THE DAKOTAS AND WESTERN MINNESOTA EARLY
THIS MORNING...AND THE SOUNDINGS SHOW SOME MIXING BELOW 2K FEET.
AS A RESULT...JUST INTRODUCED SOME MVRF FOG AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS TUCSON AZ
912 AM MST FRI JUL 25 2014
.SYNOPSIS...SHOWERS AND THUNDERSTORMS WILL INCREASE ACROSS THE
AREA TODAY AND CONTINUING INTO THIS WEEKEND WITH THE GREATEST
COVERAGE EXPECTED SATURDAY AFTERNOON AND SATURDAY NIGHT.
TEMPERATURES WILL ALSO FALL BACK CLOSER TO AVERAGE OVER THE NEXT
FEW DAYS.
&&
.DISCUSSION...SURFACE DEW POINTS HAVE GENERALLY BUMPED UP TO THE
MID 60S THIS MORNING DUE TO THE NICE MOISTURE SURGE EARLY THIS
MORNING. THE OUTFLOW THAT BROUGHT THE MOISTURE ALSO BROUGHT A GOOD
AMOUNT OF DUST FROM SONORA UP HERE...WHICH IS THE REASON FOR THE
HAZY CONDITIONS THIS MORNING. THE PREVIOUS SHIFT ADDED HAZE TO THE
GRIDS THRU 18Z...WHICH IS ABOUT THE TIME ALL HIRES GUIDANCE HAS
CONVECTION BEGINNING ACROSS THE FORECAST AREA. HIRES GUIDANCE HAS
MOST STORMS INITIALIZING ACROSS SANTA CRUZ AND COCHISE
COUNTIES...THOUGH THE STORMS OUT EAST AREN`T EXPECTED TO BE MUCH
IN THE WAY OF LONG LIVED DEVELOPMENT. MOST GUIDANCE HAVE THE
WESTERN EDGE OF THE STORMS BEGIN THE DOMINATE FLANK...WHICH WILL
LIKELY RESULT IN A STRONG OUTFLOW/BLOWING DUST TYPE EVENT.
THEREFORE...A BLOWING DUST ADVISORY IS IN PLACE STARTING AT NOON
GIVEN THE EARLY EXPECTED INITIALIZATION. 12Z SOUNDING SHOWS SOME
WEAK MID LEVEL FLOW THOUGH STRONGER FLOW IS PROGGED TO EDGE IN
THIS AFTERNOON.
THE NORTHEASTERN PORTION OF THE CWA AT THIS TIME LOOKS TO BE THE
ONE AREA THAT WON`T RECEIVE MUCH ACTIVITY. THERE ISN`T NEARLY THE
MOISTURE ACROSS GRAHAM OR GREENLEE COUNTIES. HOWEVER...GOES
SOUNDING PROFILES SHOW ENOUGH INSTABILITY FOR SOME WEAK
CONVECTION. NEVERTHELESS...THE MAIN AREA FOR DEVELOPMENT WILL BE
TUCSON TO NOGALES WESTWARD THIS AFTERNOON. IN FACT...MOST GUIDANCE
HAS THINGS ENDING AROUND TUCSON AFTER 3 PM WITH LITTLE TO NO
ACTIVITY EASTWARD. TIME WILL TELL...WILL HOLD THE INHERITED POP
GRIDS.
&&
.AVIATION...VALID THRU 26/12Z.
HIGH PRESSURE CENTERED OVER WEST TEXAS WILL RESULT IN A MOIST ELY/
SELY MID-LEVEL FLOW REGIME INTO SATURDAY MORNING. THE COMBINATION
OF STRONG DAYTIME HEATING COMBINED WITH ADEQUATE MOISTURE WILL
RESULT IN -TSRA/-SHRA MAINLY NEAR THE MOUNTAINS BY 25/19Z FROM
KTUS VICINITY EWD/SWD. SCATTERED TSRA/SHRA IS THEN FORECAST TO
MOVE TO THE WEST AND NORTHWEST THIS AFTERNOON AND THIS EVENING.
AREAS OF BLDU WITH VSBYS BELOW 1/2SM MAY OCCUR NW OF KTUS INTO
PINAL COUNTY SE OF KPHX THIS AFTERNOON AND THIS EVENING.
ELSEWHERE...MVFR VSBYS WITH WIND GUSTS GENERALLY OF 40-45 KTS WILL
OCCUR WITH THE STRONGER TSRA. THERE WILL BE ENOUGH MOISTURE TO
MAINTAIN ISOLATED -TSRA/-SHRA LATE TONIGHT AND EARLY SATURDAY
MORNING. OTHERWISE...CLOUD DECKS THIS AFTERNOON INTO SATURDAY
MORNING WILL GENERALLY BE AT 10-15K FT AGL. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...AMPLE MOISTURE WILL TRANSLATE INTO SCATTERED
THUNDERSTORMS THIS AFTERNOON AND THIS EVENING. EXPECT SCATTERED TO
NUMEROUS THUNDERSTORMS SATURDAY AFTERNOON AND SATURDAY EVENING AS
MOISTURE INCREASES ACROSS THE AREA. A GRADUAL DECREASE IN
THUNDERSTORM ACTIVITY IS THEN FORECAST TO OCCUR STARTING SUNDAY
AND CONTINUING INTO THE MIDDLE OF NEXT WEEK. HOWEVER...MOISTURE
WILL REMAIN SUFFICIENT FOR ISOLATED TO SCATTERED MAINLY AFTERNOON
AND EVENING THUNDERSTORMS.
&&
.PREV DISCUSSION... /ISSUED 300 AM MST FRI JUL 25 2014/
DISCUSSION...THE ATMOSPHERE HAS MOISTENED UP CONSIDERABLY ACROSS
SOUTHEAST ARIZONA /ESPECIALLY FROM TUCSON WESTWARD/AFTER A GULF
SURGE AIDED BY OUTFLOW FROM THUNDERSTORMS TO OUR SOUTHWEST MOVED
THROUGH THE AREA LAST NIGHT. SURFACE DEWPOINTS ARE GENERALLY IN THE
UPPER 50S TO LOWER 60S ACROSS MOST OF THE AREA WITH THE EXCEPTION OF
GRAHAM AND GREENLEE COUNTY WHERE SURFACE DEWPOINTS ARE MOSTLY IN THE
40S. THIS CORRESPONDS TO PWAT VALUES RANGING FROM UNDER AN INCH IN
GRAHAM AND GREENLEE COUNTY TO 1.2 TO 1.6 INCHES FROM TUCSON
WESTWARD.
THE HIGH PRESSURE ALOFT IS NOW IN A FAVORABLE POSITION ACROSS NEW
MEXICO. GIVEN THE INCREASE IN MOISTURE...AMPLE SUNSHINE TO START THE
DAY AND FAVORABLE EAST TO SOUTHEAST STEERING FLOW...IT IS SHAPING UP
TO BE A FAIRLY ACTIVE DAY ESPECIALLY FROM TUCSON WESTWARD WHERE THE
MOISTURE IS GREATEST. CONFIDENCE IS INCREASING ON SHOWERS AND
THUNDERSTORMS PRODUCING STRONG OUTFLOW WINDS AS REFLECTED IN THE
LATEST HRRR ALONG WITH OUR LOCAL WRF. A BLOWING DUST ADVISORY WILL
BE ISSUED ACROSS PORTIONS OF EASTERN PIMA COUNTY /JUST NORTHWEST OF
TUCSON/ ALONG WITH CENTRAL AND WESTERN PIMA COUNTY AND SOUTH-CENTRAL
PINAL COUNTY TO COVER THE DUST THREAT. STORM MOTION AROUND 10 TO 15
MPH SHOULD BE FAST ENOUGH TO PRECLUDE A WIDESPREAD FLOOD THREAT BUT
LOCALLY HEAVY RAINFALL IS POSSIBLE.
THE ACTIVE PATTERN IS EXPECTED TO CONTINUE ON SATURDAY AS THE
MOISTURE REMAINS ACROSS SOUTHEAST ARIZONA WITH AN INVERTED TROUGH
EXPECTED TO MOVE INTO THE AREA FROM THE EAST SATURDAY EVENING. THIS
SHOULD RESULT IN ADDITIONAL LIFT FOR MORE WIDESPREAD SHOWER AND
THUNDERSTORM ACTIVITY...FOCUSED LATE SATURDAY AFTERNOON INTO
SATURDAY NIGHT. GIVEN THE UPPER LEVEL SUPPORT...THE STORMS MAY VERY
LOSE DIURNAL TRENDS AND CONTINUE IN SOME FASHION OVERNIGHT SATURDAY
NIGHT. IN ADDITION...WE ARE ALSO CONCERNED ABOUT BLOWING DUST ONCE
AGAIN SATURDAY AFTERNOON AND EVENING BUT WE HAVE PLENTY OF TIME TO
HONE IN ON THOSE POSSIBLE DETAILS AS IT GETS CLOSER.
THEREAFTER...SUNDAY MAY VERY WELL BE MORE OF A DOWN DAY WITH
CONSIDERABLE CLOUDS AND A WORKED OVER ATMOSPHERE GIVEN THE EXPECTED
STORM COVERAGE SATURDAY/SATURDAY NIGHT. THE MOISTURE PLUME WILL
REMAIN OVER ARIZONA MONDAY BUT THINGS GET A BIT MORE UNCERTAIN BY
THE MIDDLE OF NEXT WEEK AS THE UPPER HIGH SHIFTS SOUTH AND WEST
CLOSER TO SOUTHEAST ARIZONA. IN FACT...THE 00Z ECMWF SHIFTS THE HIGH
CENTER A BIT SOUTH AND WEST OF US BY WEDNESDAY WITH CONSIDERABLE
DRYING. IN CONTRAST...THE 00Z GFS AND CANADIAN KEEP THE HIGH NEAR
THE AZ/NM BORDER WITH SOMEWHAT BETTER MOISTURE IN THE AREA. MADE
ONLY MINOR TWEAKS TO THE FORECAST FOR NEXT WEEK WITH GENERALLY A
LOWER GRADE MONSOON EXPECTED STARTING TUESDAY. WITH THE HIGH BEING
CLOSER TO THE AREA...TEMPERATURES WILL ALSO BE ON THE INCREASE NEXT
WEEK...RISING TO ABOUT 5 TO 7 DEGREES ABOVE NORMAL VALUES FOR LATE
JULY.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
BLOWING DUST ADVISORY FROM NOON TODAY TO 9 PM MST THIS EVENING
FOR AZZ501-502-504-505.
&&
$$
PUBLIC...MEADOWS
PREV DISCUSSION...LADER
AVIATION/FIRE WEATHER....FRANCIS
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
223 PM PDT FRI JUL 25 2014
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ANCHORED OVER THE DESERT SOUTHWEST THROUGH
THE MIDDLE OF NEXT WEEK RESULTING IN CONTINUED SEASONAL TO ABOVE
NORMAL TEMPERATURES. HIGH CLOUDS WILL STREAM THROUGH THE AREA WITH A
SLIGHT POSSIBILITY OF A THUNDERSTORM OVER THE SAN GABRIELS MAINLY
SUNDAY AFTERNOON. OVERNIGHT LOW CLOUDS AND FOG ARE EXPECTED ALONG
MOST COASTAL AREAS.
&&
.SHORT TERM (REST OF TODAY-MON)...STILL KEEPING AN EYE ON THE LINE
OF THICKER CLOUDS AND ISOLATED CONVECTION INCHING NORTHWARD ON A
LINE FROM JUST NORTH OF LAS VEGAS SOUTHWESTWARD TOWARD JUST SOUTH OF
CATALINA AT THIS TIME. MOST ACTIVE CONVECTION IS IN THE PALM SPRINGS
AREA...OTHERWISE KSOX INDICATING ECHOES OFFSHORE JUST SOUTH OF
CATALINA...ALTHOUGH ONLY WELL ALOFT AT THIS TIME. THIS ACTIVITY IS
IN PART DUE TO A WEAK WAVE APPARENT IN THE FLOW AROUND THE LARGE
HIGH STILL CENTERED OVER THE SOUTHERN HIGH PLAINS. THE RUC MODEL
(PER 400 MB VORT) SORT OF WASHES THIS OUT WITH TIME THIS
EVENING...THOUGH STILL APPARENT. LATEST LIFTED INDEX VALUES STILL
REMAIN LOWEST EAST OF OUR AREA WITH JUST BELOW ZERO VALUES INTO OUR
AREA...BUT FORECAST TO STABILIZE AFTER 21Z. VISIBLE SATELLITE
IMAGERY AND DOWNTOWN LA WEBCAMS SHOW CU TRYING TO BUILD ON THE
NORTHERN EDGE OF THE EASTERN SAN GABRIELS...BUT UPDRAFTS LOOK WEAK
AND DISORGANIZED SO FAR. LATEST HIGH RESOLUTION RAPID REFRESH (HRRR)
MODEL RUN FROM 19Z ALSO KEEPS PRECIPITATION OUT OF OUR AREA. FOR
NOW BELIEVE NOTHING OF SIGNIFICANCE WILL MATERIALIZE FROM THIS OTHER
THAN SOME INCREASING MID AND HIGH CLOUDINESS ACROSS LOS ANGELES AND
PARTS OF VENTURA COUNTIES....BUT WILL CONTINUE TO MONITOR. MAY NEED
TO AT LEAST INCREASE THE FORECAST SKY COVER FOR THIS EVENING OVER
THESE AREAS.
BEYOND THE REST OF THIS AFTERNOON AND EVENING...THE PRIMARY FACTOR
IN THE FORECAST IS THE PERSISTENT HIGH PRESSURE SYSTEM OVER THE
WESTERN U.S. WHICH WILL VARY IN AXIS POSITION AND SHAPE OVER THE
NEXT 7 DAYS. THE RESULT WILL MEAN LITTLE CHANGE IN THE DAY TO DAY
CONDITIONS. AFTERNOON TEMPERATURES WILL CHANGE LITTLE EACH
DAY...REMAINING FROM JUST ABOVE NORMAL VALLEYS AND INLAND...BUT WITH
SOME ONSHORE FLOW THROUGH THE PERIOD...THE COASTAL AREAS WILL REMAIN
AT OR JUST BELOW NORMAL.
EXPECT A SLIGHT INCREASE IN COVERAGE ALONG THE COASTS OF THE
OVERNIGHT CLOUDS AND FOG TONIGHT...AND A REPEAT PERFORMANCE ON
SUNDAY AND MONDAY. WITH THE ONSHORE FLOW COMES GUSTY SOUTHWEST WINDS
EACH AFTERNOON IN THE ANTELOPE VALLEY...BUT STAYING BELOW ADVISORY
CRITERIA.
THE ONE HICCUP IN THE PERSISTENCE FORECAST MAY BE SUNDAY AFTERNOON
AND EVENING IN THE LA AND VTU COUNTY MOUNTAINS AND THE ANTELOPE
VALLEY. SOME INDICATIONS OF SOME CONVECTIVE ACTIVITY THESE AREAS
SUNDAY AFTERNOON. CONVECTIVE PARAMETERS NOT OVERLY IMPRESSIVE OTHER
THAN MODELS INDICATING A POSSIBLE SHORT WAVE THAT ROTATES AROUND THE
SOUTH SIDE OF THE HIGH THEN ROTATES AROUND AND BRUSHES OUR AREA ON
SUNDAY. THIS WILL COME INTO BETTER FOCUS WITH NEW MODEL RUNS BUT
HAVE KEPT THE GOING FORECAST OF A SLIGHT CHANCE OF THUNDER OVER THE
EASTERN SAN GABRIELS FOR NOW.
.LONG TERM (TUE-FRI)...THE UPPER LEVEL HIGH OVER THE WESTERN U.S.
PERSISTS THROUGH THE LONG TERM. THE ONE CHANGE IS THAT IT PUMPS UP
INTO SOUTHWEST CANADA AS OPPOSED TO THE EAST-WEST ELONGATED HIGH
THAT IT`S BEEN AS OF LATE. THE ECMWF PUTS THE HIGH AXIS A LITTLE
FURTHER WEST...THE RESULT BEING AROUND A 585 DM THICKNESS OVER SOCAL
ON WEDN AFTN VERSUS THE 579 DM THICKNESS FORECAST BY THE GFS. THIS
WOULD RESULT IN WARMER TEMPS MIDWEEK. DISCOUNTING THE ECMWF FOR NOW
IN PART SINCE THE OPERATIONAL GFS IS IN LINE WITH THE GFS ENSEMBLES.
SO GOING WITH THE GFS...NOT MUCH CHANGE IN SENSIBLE SURFACE WEATHER
FROM DAY TO DAY. TEMPERATURES JUST ABOVE AVERAGE VALLEYS AND DESERT
AND AT OR JUST BELOW AVERAGE COASTAL AREAS. ONSHORE GRADIENTS WILL
CHANGE LITTLE EACH DAY SO EXPECT SOME OVERNIGHT LOW CLOUDS AND FOG
ALONG THE COASTS...BUT AT THIS TIME WITH NOT MUCH INLAND EXTENT. WE
APPEAR TO BE RIGHT ON THE WESTERN EDGE OF ANY MONSOONAL FLOW SO
DIFFICULT TO TELL AT THIS POINT WHEN WE MAY GET ENOUGH MOISTURE THIS
FAR WEST FOR ANY CONVECTIVE ACTIVITY. AT THIS TIME HAVE NOT INCLUDED
ANY MENTION OF IT DURING THIS PERIOD.
&&
.AVIATION...25/18Z...
MODERATE TO HIGH CONFIDENCE IN THE 18Z TAFS. SLOW CLEARING IN SOME
COASTAL LOCATIONS THOUGH VFR CONDITIONS ARE IN PLACE THROUGHOUT THE
SERVICE AREA. THE MARINE LAYER IS EXPECTED TO RETURN TO ALL COASTAL
SITES OVERNIGHT IN A SIMILAR PATTERN AS THIS MORNING THOUGH FOR A
SLIGHTLY LONGER DURATION. OTHERWISE AND ELSEWHERE VFR CONDITIONS
ARE EXPECTED.
KLAX...MODERATE CONFIDENCE IN THE 18Z TAF. THE MARINE LAYER IS
EXPECTED TO RETURN OVERNIGHT IN A SIMILAR PATTERN AS THIS MORNING
THOUGH FOR A SLIGHTLY LONGER DURATION. THERE IS A 20 PERCENT CHANCE
THAT CIGS WILL SLIP INTO THE IFR CATEGORY FOR ONE TO THREE HOURS
THROUGH 16Z... A 10 TO 20 PERCENT CHANCE THAT CIGS WILL LINGER UNTIL
AS LATE AS 19Z... AND A 20 PERCENT CHANCE THAT EAST WINDS WILL REACH
OR EXCEED 9 KNOTS BETWEEN 13Z AND 16Z. OTHERWISE VFR CONDITIONS ARE
EXPECTED.
KBUR...HIGH CONFIDENCE IN THE 18Z TAF. VFR CONDITIONS EXPECTED
THROUGHOUT THE FORECAST PERIOD.
&&
.MARINE...25/230 PM...
HIGH CONFIDENCE IN CURRENT FORECAST. WINDS AND SEAS ARE CONTINUING
TO DECREASE THOUGH SOME SENSORS INDICATE LOCAL SEA HEIGHTS ARE A BIT
SLOWER TO DECREASE THAN EARLIER EXPECTED... POSSIBLY DUE TO A SMALL
BUMP IN THE WIND WAVES. THEREFORE THE SMALL CRAFT ADVISORY FOR
HAZARDOUS SEAS HAS BEEN EXTENDED INTO THE EVENING HOURS. OTHERWISE
CONDITIONS ARE EXPECTED TO REMAIN BELOW ADVISORY CRITERIA THROUGH
THE REMAINDER OR THE FORECAST PERIOD.
REPORTS OF MOSTLY DRY LIGHTNING TO THE SOUTH AND EAST OF THE
FORECAST AREA TODAY AND ANY FURTHER THUNDERSTORM DEVELOPMENT IS
EXPECTED TO REMAIN OUT OF THE AREA THROUGH TONIGHT. THE BOUNDARY
UPON WHICH THE CONVECTION IS DEVELOPING WILL BE SHIFTING
NORTHWESTWARD THROUGH SUNDAY... HOWEVER... AND MAY MOVE INTO ZONES
676 AND 655 BY SUNDAY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS (SEE LAXMWWLOX).
&&
$$
PUBLIC...MJ
AVIATION...KJ
MARINE...KJ
SYNOPSIS...MJ
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1112 AM MDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 1050 AM MDT FRI JUL 25 2014
MOST OF THE PLAINS SHOW NORTHEASTERLY FLOW LEVEL WINDS RIGHT NOW.
THERE IS PLENTY OF MID AND UPPER LEVEL CLOUDS AROUND. THE
CONVECTIVE CLOUDINESS HAS STARTED IN THE MOUNTAINS AND FOOTHILLS
BUT THERE ARE VERY FEW ECHOES ON THE RADAR. WE ARE ONE DEGREE F
COOLER AT DIA RIGHT NOW THAN WE WERE YESTERDAY. THE LATEST DIA
ACARS SOUNDINGS ARE SHOWING A STABLE LAYER AROUND 15000 FEET MST.
THE PLAINS HAVE DEW POINTS MOSTLY IN THE LOWER 50S F RIGHT
NOW...A FEW PLACES A BIT LOWER. MODELS CONTINUE TO SHOW SOME AREAS
OF 1000 J/KG PLUS CAPES THIS AFTERNOON OVER SOME OF THE CWA. WILL
KEEP THE GOING POPS PRETTY MUCH ALONE FOR NOW. WILL UP
TEMPERATURES A BIT AND MAKE A FEW MINOR CLOUD COVER ALTERATIONS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 330 AM MDT FRI JUL 25 2014
THE UPPER HIGH HAS SHIFTED SOUTH OF COLORADO DURING THE PAST 12
HOURS AND IS NOW CENTERED OVER NEW MEXICO AND WESTERN TEXAS. THIS
HAS RESULTED IN A MORE WESTERLY FLOW ALOFT OVER COLORADO WITH MAIN
MOISTURE PLUME ACROSS NORTHERN AND CENTRAL PORTIONS OF THE STATE.
INTEGRATED PRECIPITABLE WATER VALUES ARE JUST UNDER AN INCH OVER
FRONT RANGE. EXPECT THIS PLUME OF MOISTURE TO HOLD OVER THE REGION
FOR THIS AFTERNOON AND TONIGHT WITH PW VALUES REMAINING CLOSE TO
AN INCH. THERE ARE STILL ISOLATED SHOWERS AND THUNDERSTORMS
CONTINUING OVER MOUNTAINS AND WEST AND HAVE ADDED LOW POPS FOR THE
PRE DAWN HOURS.
A WEAK COLD FRONT WILL MOVE SOUTH FROM WYOMING DURING THE EARLY
MORNING HOURS OVER NORTHEAST COLORADO WITH NORTHEAST TO EAST WINDS
DEVELOPING BEHIND THE FRONT. THERE WILL BE SOME COOLING AND LOW
LEVEL STABILITY THIS AFTERNOON BUT LOW LEVEL CAP LOOKS TO ERODE BY
LATE AFTERNOON WHILE SURFACE DEWPOINTS REMAIN IN THE UPPER 40S AND
LOWER 50S. SHOULD BE ENOUGH INSTABILITY AND AMPLE MOISTURE FOR A
ROUND OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. LATEST HRRR
SHOWING A BROAD AREA OF SHOWERS MOVING OFF THE FOOTHILLS BETWEEN
20-22Z. THE RAP/NAM SEEM TO HOLD MORE OF THE SHOWERS ANCHORED ON
HIGHER TERRAIN WITH MORE ISOLATED ACTIVITY ON THE PLAINS. GIVEN
THE AMOUNT OF MOISTURE WOULD FAVOR THE HRRR SOLUTION AND WILL BUMP
POPS UP SLIGHTLY TO CHANCE CATEGORIES BY LATE AFTERNOON OVER THE
FRONT RANGE AND ADJACENT PLAINS. LIKE YESTERDAY...MAIN THREATS
WILL BE BRIEF HEAVY RAIN AND GUSTY WINDS TO AROUND 50 MPH WITH THE
STRONGER STORMS.
TEMPERATURES WILL BE COOLER TODAY FOLLOWING THE
FRONTAL PASSAGE WITH READINGS AROUND 90 DEGREES OVER LOWER
ELEVATIONS. MOST OF THE STORMS WILL DIMINISH BY LATER THIS EVENING
WITH LACK OF ANY SIGNIFICANT FORCING ALOFT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 AM MDT FRI JUL 25 2014
ANOTHER WEAK BACKDOOR COLD FRONT IS EXPECTED TO PUSH ACROSS THE
PLAINS ON SATURDAY...RESULTING IN SLIGHT COOLING AND
STABILIZATION. THE AIRMASS WILL LIKELY REMAIN CAPPED OVER THE
NORTHEAST CORNER OF THE STATE...WHILE THE MOUNTAINS WILL STILL SEE
SCATTERED SHOWERS AND STORMS IN THE AFTERNOON AND EVENING AS
MID/UPPER LEVEL MOISTURE PLUME REMAINS ACROSS THE FORECAST AREA.
IN BETWEEN...THE ENVIRONMENT WILL BE MARGINAL FOR STORMS...BUT
WITH WESTERLY FLOW ALOFT WE SHOULD SEE ISOLATED SHOWERS/STORMS DRIFT
OFF THE FRONT RANGE AND HELP POP A FEW CELLS THROUGH THE CAP.
ON SUNDAY...TEMPERATURES WILL TREND A GOOD 5-10 DEGREES COOLER
ACROSS THE PLAINS BEHIND A DEEPENING POOL OF COOL AIR. THERE WILL
BE A THETA-E MINIMUM AND SLIGHT DRYING ACROSS MOST OF THE PLAINS
AS WELL...WHICH SHOULD EFFECTIVELY CUT OFF THE NORTHEAST PLAINS
FROM CONVECTION. MEANWHILE...MOUNTAIN AREAS WILL SEE ENOUGH
INSTABILITY FOR ANOTHER ROUND OF SCATTERED SHOWERS AND
STORMS...WITH A FEW POSSIBLY DRIFTING OFF THE FOOTHILLS INTO THE
I-25 CORRIDOR ONCE AGAIN BY LATE AFTERNOON/EVENING. AT THIS
TIME...LOOKS LIKE MAIN THREAT WOULD BE CLOSER TO THE PALMER DIVIDE
AREA HOWEVER AS AIRMASS FARTHER NORTH IS DRYING.
BY MONDAY...LOW LEVEL MOISTURE BEGINS TO RETURN AND INCREASE IN
SOUTH/SOUTHEAST FLOW. MEANWHILE...THETA-E RIDGE BUILDS IN/NEAR THE
FRONT RANGE WITH CAPES INCREASING TO AROUND 1500 J/KG. THIS ALONG
WITH SUFFICIENT SHEAR IN NORTHWEST FLOW ALOFT COULD LEAD TO A FEW
SEVERE STORMS.
ON TUESDAY...LOW LEVEL MOISTURE WILL LIKELY CONTINUE TO POOL ALONG
THE FRONT RANGE WHILE A SHORT WAVE IS STILL BEING ADVERTISED TO
DROP ACROSS THE REGION IN NORTHWEST FLOW ALOFT. THE UPSLOPE
COMPONENT IS ALSO PROGGED BY VARIOUS MODELS TO DEEPEN THROUGH 700
MB...COLLECTIVELY RESULTING IN A GOOD CHANCE OF SHOWERS AND
THUNDERSTORMS. CAPE MAY BE LIMITED BY COOLER TEMPERATURES...BUT
HIGH PRECIPITABLE WATER VALUES AND LIKELY SKINNY CAPE PROFILE
SUGGESTS POTENTIAL FOR HEAVY RAINFALL.
WEDNESDAY AND THURSDAY WILL FEATURE A CONTINUATION OF A COOL AND
SOMEWHAT UNSETTLED WEATHER PATTERN. BEST CHANCE SHOULD REFOCUS TO
THE ELEVATED TERRAIN THOUGH AS AIRMASS ON THE PLAINS WOULD BE MORE
STABLE BEHIND TUESDAYS WAVE AND WITH COOLER TEMPERATURES HOLDING
IN PLACE. PLAINS LOCATIONS MAY STRUGGLE TO REACH 80F BOTH DAYS.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z SATURDAY MORNING)
ISSUED AT 1050 AM MDT FRI JUL 25 2014
WINDS ARE A BIT TROUBLESOME AT DIA RIGHT. THERE IS A PRETTY
UNIFORM NORTHEASTERLY WIND FIELD OVER MOST OF THE PLAINS RIGHT
NOW...EXCEPT FOR THE BIG AIRPORT. THE RADAR POINTS TO
NORTHEASTERLIES AT DIA EVENTUALLY. THERE WILL BE NO CEILING
ISSUES THIS AFTERNOON. WINDS GUSTS ASSOCIATED WITH CONVECTION
COULD BE AN ISSUE THIS AFTERNOON/EARLY EVENING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RJK
SHORT TERM...ENTREKIN
LONG TERM...BARJENBRUCH
AVIATION...RJK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
248 PM CDT FRI JUL 25 2014
.DISCUSSION...
324 AM CDT
SYNOPSIS...A TRICKY UNSETTLED FORECAST IS EXPECTED TODAY THROUGH
SUNDAY. THEN THINGS QUIET DOWN FOR THE BEGINNING OF THE WORK WEEK.
SATURDAY WILL BE THE WARMEST DAY IN THE FORECAST WITH HIGHS NEAR
90. TEMPS THEN FALL TO BELOW NORMAL SUNDAY AND SLOWLY BEGIN TO
CLIMB BACK TO NEAR 80 BY LATE NEXT WEEK.
TODAY AND TONIGHT...
AN UPPER LEVEL HIGH IS OVER THE SOUTHWEST U.S. AND SOUTHERN PLAINS
WHILE LOW PRESSURE IS OVER THE ALBERTA/SASKATCHEWAN BORDER. THE
HIGH WILL SLOWLY RETROGRADE THROUGH MONDAY AFTERNOON TO OVER THE SW
U.S. WHILE THE LOW PASSES OVER LAKE MICHIGAN SUNDAY EVENING. AT THE
SURFACE HIGH PRESSURE IS OVER THE OHIO RIVER VALLEY AND IT WILL MOVE
OFF THE ATLANTIC COAST TONIGHT. THERE ARE TWO SURFACE LOWS...ONE
OVER THE NORTHERN PLAINS AND THE SECOND CO-LOCATED WITH THE UPPER
LEVEL LOW OVER THE ALBERTA/SASKATCHEWAN BORDER.
CONVECTION IS ONGOING OVER WEST CENTRAL MINNESOTA AND IOWA VERY
EARLY THIS MORNING. THE STORMS WILL BE MOVING INTO A MORE STABLE
ENVIRONMENT AND THE LOW LEVEL JET WILL ALSO BE WEAKENING AS IT
PUSHES EAST. THERE IS HIGH CONFIDENCE THAT THE STORMS OVER IOWA WILL
WEAKEN AS THEY APPROACH THE CWA...BUT EXPECTING SHOWERS AND A COUPLE
OF STORMS TO REACH THE I-39 CORRIDOR BY MID MORNING. SOME GUIDANCE
MEMBERS SUGGEST SHOWERS AND STORMS COULD LINGER INTO THE MID
AFTERNOON HOURS BUT THINKING THEY WILL DISSIPATE BY THE EARLY
AFTERNOON.
HIGH CLOUDS WILL BE OVERHEAD AND MAY LIMIT HEATING A BIT...AS SUCH
LEFT HIGH TEMPS TODAY IN THE UPPER 70S.
MULTIPLE ROUNDS OF STORMS ARE EXPECTED WITH THE SECOND ROUND
SPREADING SOUTH THIS EVENING. THE LOW OVER THE PLAINS WILL WEAKEN AS
IT PUSHES EAST AND FORM AN OPEN TROUGH. THE LOWS WARM FRONT WILL
APPROACH THE REGION TONIGHT AND EXPECTING STORMS AHEAD OF IT. THE
NOSE OF THE LOW LEVEL JET WILL ALSO BE OVER NORTHWEST IL THIS
EVENING PROVIDING ADDITIONAL LIFT. CAPE WILL BE LIMITED WITH
MODEL SOUNDINGS SHOWING SHALLOW AREAS OF CAPE AT 1000 J/KG OR LESS.
PWAT VALUES WILL BE AROUND 1.9 INCHES SO TORRENTIAL DOWNPOURS ARE
THE MOST LIKELY HAZARD.
SATURDAY...
THE PLAINS LOW/TROUGH MOVES OVER THE MIDWEST WITH SATURDAY
HAVING THE BEST CHANCE FOR SEVERE WEATHER ESPECIALLY SOUTH OF I-88.
PWAT VALUES REMAIN HIGH AROUND 1.8 INCHES IN THE MORNING AND THEN
INCREASE TO 2-2.3 INCHES SOUTH OF I-80 SATURDAY AFTERNOON. CAPE
VALUES WILL BE MUCH MORE HEALTHY IN THE 3000 J/KG RANGE ESPECIALLY
ALONG AND SOUTH OF THE I-80 CORRIDOR. EXPECTING STORMS TO FIRE
ALONG THE LOWS COLD FRONT SATURDAY AFTERNOON AND EVENING WITH THE
CHANCES OF SHOWERS AND STORMS INCREASING AS YOU HEAD SOUTH. SOME OF
THESE STORMS MAY BE SEVERE WITH TORRENTIAL DOWNPOURS. HAIL AND WIND
LOOK TO BE THE MAIN SEVERE THREATS.
SATURDAY WILL FEEL UNPLEASANT TO MANY WITH HIGHS IN THE UPPER 80S
AND HIGH DEWPOINTS. MAX HEAT INDICES WILL BE IN THE 90S...WITH MID
TO UPPER 90 HEAT INDICES EXPECTED SOUTH OF I-80.
SUNDAY...
THE LOW OVER CANADA DRIFTS SOUTHEAST MOVING OVER WISCONSIN SUNDAY.
ADDITIONAL THUNDERSTORMS ARE POSSIBLE NORTH OF THE I-80
CORRIDOR...WITH THE BEST CHANCES ALONG THE IL/WI STATE LINE. THE
STORMS PUSH EAST OF THE CWA IN THE EVENING. COOLER AIR ASSOCIATED
WITH THE LOW ALSO SPREAD SOUTH WITH HIGHS ON SUNDAY ONLY EXPECTED TO
GET INTO THE LOW TO MID 80S. OVERNIGHT LOWS WILL BE AROUND
60...EXCEPT FOR DOWNTOWN WHICH WILL BE IN THE LOW 60S.
MONDAY THROUGH THURSDAY...
WE REMAIN UNDER THE UPPER LEVEL TROUGH THROUGH NEXT WEEK WITH A
SURFACE HIGH MOVING OVER THE REGION BY MID WEEK. THERE ARE
OCCASIONAL CHANCES OF SHOWERS AND STORMS BUT NONE OF THOSE CHANCES
LOOK ALL THAT IMPRESSIVE AT THIS POINT. THE BIGGER STORY WILL BE
ANOTHER EXTENDED PERIOD OF BELOW NORMAL TEMPS...ALTHOUGH
TEMPERATURES WILL BE SLOWLY RISING THROUGH THE END OF THE FORECAST
PERIOD.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SOUTH-SOUTHWEST WINDS GUSTING AROUND 20 KT THIS AFTERNOON.
* PERIOD OF MVFR CIGS 2500-3000 FT FOR A TIME THIS AFTN/EARLY
EVENING.
* CHANCE OF TSRA INCREASES LATE TONIGHT.
* PERIOD OF MVFR CIG/FOG POSSIBLE EARLY SATURDAY.
* WIND DIRECTION SOMEWHAT VARIABLE SAT MORNING.
RATZER
//DISCUSSION...UPDATED 20Z...
REMNANT BOUNDARY FROM IOWA CONVECTION HAS PUSHED ACROSS NORTHERN
IL WITH AN AREA OF MVFR STRATOCU SPREADING IN FROM THE NORTHWEST
BEHIND IT. HAVE INDICATED A FEW HOUR PERIOD OF CIGS FOR REMAINDER
OF AFTERNOON HOURS. SHRA/TSRA POTENTIAL CONTINUES TO APPEAR FAIRLY
LOW UNTIL LATER TONIGHT.
RATZER
PREVIOUS DISCUSSION FROM 18Z...
LOW PRESSURE WAS OVER EASTERN NEBRASKA AT MIDDAY...WITH A WARM
FRONT EXTENDING SOUTHEAST ACROSS THE LOWER MISSOURI RIVER VALLEY.
CIRCULATION ASSOCIATED WITH A MID-LEVEL DISTURBANCE/REMNANT MCV
OVER SOUTHERN WI WAS PRODUCING SOME RAIN ACROSS WI...BUT ONLY
SPOTTY SHRA INTO NORTHERN FOR THE MOST PART...WHILE A COMPLEX OF
THUNDERSTORMS CONTINUES TO MOVE SOUTHEAST ALONG THE MISSISSIPPI
RIVER INTO WESTERN/SOUTHERN IL. TERMINALS WILL REMAIN IN AN AREA
OF BROAD MOIST ASCENT INTO TONIGHT...WITH NOCTURNAL INCREASE IN
LOW LEVEL JET AND AN APPROACHING MID-LEVEL WAVE EXPECTED TO
EVENTUALLY SHIFT THE ELEVATED WARM FRONTAL ZONE EASTWARD AND
PRODUCE SCATTERED THUNDERSTORM THREAT OVER THE TERMINALS LATER
TONIGHT. PATTERN IS RELATIVELY MESSY HOWEVER...WITH FAIRLY LOW
CONFIDENCE IN TIMING DETAILS BEYOND THE OVERALL TREND AT THIS
TIME. AT THIS TIME HOWEVER...IT APPEARS THAT THE GREATEST
THUNDERSTORM THREAT WILL BE TOWARD/AFTER MIDNIGHT. LOW LEVEL JET
THEN TO BECOME MORE WEST/NORTHWEST BY SATURDAY
MORNING...DECREASING THUNDERSTORM POTENTIAL OVER TERMINALS AFTER
SUNRISE. SOME POTENTIAL WILL EXIST FOR BRIEF PERIOD OF MVFR
CEILING AND SOME GROUND FOG WILL EXIST EARLY SATURDAY MORNING
ESPECIALLY WHERE ORGANIZED RAINS FALL.
SOUTHERLY SURFACE WINDS GUSTING AROUND 20 KT THIS AFTERNOON IN
RESPONSE TO PRESSURE FALLS ACROSS WI/IA...APPARENTLY ENHANCED OVER
WESTERN IL BY WAKE LOW BEHIND MISSISSIPPI VALLEY THUNDERSTORM
COMPLEX. WINDS DIMINISH TONIGHT AFTER SUNSET AS GRADIENT WEAKENS
WITH APPROACH OF SURFACE TROUGH. WINDS SHOULD SHIFT MORE
WEST/NORTHWEST SATURDAY MORNING AS SURFACE TROUGH/COLD FRONT SAGS
SOUTHEAST ACROSS THE AREA...THOUGH GUIDANCE INDICATES SOME
VARIABILITY IN WIND DIRECTION IN WEAK GRADIENT NEAR THE TROUGH.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 120...
* MEDIUM CONFIDENCE IN PERIOD OF MVFR CIGS AT ORD/MDW THIS AFTN.
* LOW CONFIDENCE IN SHRA THIS AFTN/EVENING. MEDIUM CONFIDENCE IN
TSRA LATE TONIGHT.
* MEDIUM CONFIDENCE IN WIND TRENDS THIS AFTERNOON/EVENING. LOW
CONFIDENCE IN WIND DIRECTION DETAILS SATURDAY MORNING.
* LOW CONFIDENCE IN MVFR CIG/VIS DEVELOPMENT LATE TONIGHT/EARLY
SATURDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SMALL CHANCE OF TSRA.
SUNDAY...CHANCE OF TSRA.
MONDAY...VFR LIKELY. STRONG NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-THURSDAY...SLIGHT CHANCE OF TSRA.
MTF
&&
.MARINE...
205 PM CDT
SOUTHERLY WINDS WILL CONTINUE TO STRENGTHEN OVER THE LAKE THIS
AFTERNOON AND TONIGHT AS HIGH PRESSURE MOVES OFF THE MID ATLANTIC
COAST WHILE LOW PRESSURE MOVES ACROSS THE MIDDLE AND UPPER
MISSISSIPPI VALLEY. THE SURFACE TROUGH LEADING TO THE INCREASE IN
WINDS WILL WEAKEN AND DISSIPATE SATURDAY. LOW PRESSURE DROPPING
OUT OF THE CANADIAN ROCKIES AND TRACKING ACROSS THE SOUTHERN
CANADIAN PRAIRIES WILL BECOME THE MORE DOMINANT FEATURE TO AFFECT
LAKE MICHIGAN AS IT TRACKS ACROSS LAKE SUPERIOR AND LAKE MICHIGAN
SATURDAY NIGHT. WINDS WILL BECOME WEAKER AND MORE VARIABLE WITH THE
LOW WEAKENING AS IT PASSES ACROSS THE WESTERN GREAT LAKES REGION
SATURDAY NIGHT. A SURGE OF MUCH COOLER AIR WITH PUSH SOUTH DOWN
THE LENGTH OF THE LAKE SUNDAY NIGHT AND MONDAY WITH WINDS BECOMING
NORTHERLY AND INCREASING TO ARND 30KT...WITH A FEW GALE FORCE
GUSTS TO 35 KT POSSIBLE. THE MOST LIKELY PERIOD TO SEE THE GALE
FORCE GUSTS SHOULD BE SATURDAY NIGHT INTO SUNDAY MORNING WHEN THE
COLD ADVECTION FOLLOWING THE PASSAGE OF THE LOW AND AN ASSOCIATED
COLD FRONT WILL BE THE STRONGEST. HIGH PRESSURE WILL QUICKLY BUILD
ACROSS THE PLAINS MONDAY AND SPREAD ACROSS THE UPPER MISSISSIPPI
VALLEY AND WESTERN GREAT LAKES MONDAY NIGHT AND THEN SETTLE INTO
THE OHIO VALLEY BY TUESDAY. ANOTHER WEAK LOW TRACKING
SOUTHEASTWARD ACROSS ONTARIO WILL KEEP GENERALLY NORTHWESTERLY TO
WESTERLY WINDS OVER THE LAKE INTO TUESDAY.
WHILE A GALE HEADLINE WILL NOT BE ISSUED WITH THE STRONG NORTH
WINDS SUNDAY NIGHT AND MONDAY...WINDS AND WAVES WILL LIKELY BE
SUFFICIENT TO NECESSITATE A SMALL CRAFT ADVISORY.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
229 PM CDT Fri Jul 25 2014
.DISCUSSION...
ISSUED 220 PM CDT Fri Jul 25 2014
SHORT TERM...Tonight through Monday
Main forecast challenge revolves around the threat for severe
thunderstorms tomorrow afternoon and evening as a rather vigorous
upper wave shifts southeast into the upper Great Lakes. A secondary
concern will be with the Heat Index values forecast around 100
tomorrow afternoon.
Warm front forecast to shift northeast across the area tonight
with the better chances for storms along and to its northeast
tonight. That would put the higher pops across the east with
areas in the warm sector seeing a fairly significant warm layer
push in from the west. That capping inversion is now forecast to
break down quicker than earlier forecast as the upper dynamics
associated with the shortwave arrives sooner into our area tomorrow
afternoon. Any morning storms in the east should push out with a
frontal boundary drapped across parts of central Illinois as the main
upper level system approaches. Storms are expected to quickly initiate
tomorrow afternoon and spread east-southeast over central through
east central and southeast Illinois thru the evening hours. Extreme
instability levels and strong shear (Sfc base capes around 4000 j/kg,
and effective shear values 40-50 kts) suggest that supercells may
develop initially before translating into a fast moving Quasi Linear
Convective System by evening. Primary threats will be damaging wind
gusts, large hail and torrential rainfall. Any persistent rotating
storms that interact with the boundary across central Illinois have
the potential to produce a tornado or two early, before translating
to a fast moving line of storms by late afternoon or evening. Models
indicate the low level jet will veer rather quickly into a west
southwest component early tomorrow evening suggesting the potential
for the storms in the evening to back-build, increasing our chances
for heavy rainfall as well.
What`s left of the storms Sunday morning will be affecting southeast
Illinois with the threat for some heavy rainfall. Models indicate
the initial front should be pushing off to our east by mid-afternoon
so there is still a narrow window of opportunity for redevelopment
over parts of southeast Illinois in the afternoon on Sunday, with
low chance pops remaining to the northwest during the afternoon
hours. The cooler and drier air mass will start to settle southeast
into our area Sunday night and Monday as a large trof deepens in north
of the Great Lakes for early next week.
LONG TERM...Tuesday through Friday
Ensembles in reasonable agreement with respect to the unseasonably
deep trof over the eastern portion the country thru at least the first
half of the work week. Only question during this period will be with
several shortwaves forecast to rotate southeast into the lower Great
Lakes coupled with some rather cool temperatures aloft which may bring
us some diurnally driven showers later in the week. That would start
on Wednesday across our far northeast, with the instability shower
threat spreading over the remainder of the forecast area on Thursday
and Friday. Based on the 850 mb temp forecasts during this period, the
coolest temps will be Tue and Wed, with some day to day moderation seen
for the remainder of the period.
Smith
&&
.AVIATION...
ISSUED 1250 PM CDT Fri Jul 25 2014
MCS over central IL and ne MO with widespread showers and isolated
thunderstorms will gradually weaken during the afternoon as cap
increases and low level jet weakens. Showers have just passed se of
PIA and will end at BMI in next hour and along I-72 during mid
afternoon. MVFR ceilings and vsbys to occur at times with rain
showers with isolated thunderstorms possible especially at SPI and
possibly DEC next hour or so. Carried VCSH during mid afternoon
until sunset across central IL. Models have differ solutions
tonight and Sat morning with NAM model generally dry while RUC has
qpf just ne of BMI & CMI after 08Z/3 am tonight. Kept tafs dry
after dusk tonight into Sat morning and feel best chances of
convection will develop during Saturday afternoon as frontal
boundary drops southward toward I-72 into very unstable tropical
airmass. SSW winds 7-13 kts this afternoon and near or just below
10 kts tonight veer more sw on Sat morning. Wind shift with front
dropping south to occur after 18Z Sat especially at northern taf
sites of PIA and BMI.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
112 PM CDT FRI JUL 25 2014
.DISCUSSION...
324 AM CDT
SYNOPSIS...A TRICKY UNSETTLED FORECAST IS EXPECTED TODAY THROUGH
SUNDAY. THEN THINGS QUIET DOWN FOR THE BEGINNING OF THE WORK WEEK.
SATURDAY WILL BE THE WARMEST DAY IN THE FORECAST WITH HIGHS NEAR
90. TEMPS THEN FALL TO BELOW NORMAL SUNDAY AND SLOWLY BEGIN TO
CLIMB BACK TO NEAR 80 BY LATE NEXT WEEK.
TODAY AND TONIGHT...
AN UPPER LEVEL HIGH IS OVER THE SOUTHWEST U.S. AND SOUTHERN PLAINS
WHILE LOW PRESSURE IS OVER THE ALBERTA/SASKATCHEWAN BORDER. THE
HIGH WILL SLOWLY RETROGRADE THROUGH MONDAY AFTERNOON TO OVER THE SW
U.S. WHILE THE LOW PASSES OVER LAKE MICHIGAN SUNDAY EVENING. AT THE
SURFACE HIGH PRESSURE IS OVER THE OHIO RIVER VALLEY AND IT WILL MOVE
OFF THE ATLANTIC COAST TONIGHT. THERE ARE TWO SURFACE LOWS...ONE
OVER THE NORTHERN PLAINS AND THE SECOND CO-LOCATED WITH THE UPPER
LEVEL LOW OVER THE ALBERTA/SASKATCHEWAN BORDER.
CONVECTION IS ONGOING OVER WEST CENTRAL MINNESOTA AND IOWA VERY
EARLY THIS MORNING. THE STORMS WILL BE MOVING INTO A MORE STABLE
ENVIRONMENT AND THE LOW LEVEL JET WILL ALSO BE WEAKENING AS IT
PUSHES EAST. THERE IS HIGH CONFIDENCE THAT THE STORMS OVER IOWA WILL
WEAKEN AS THEY APPROACH THE CWA...BUT EXPECTING SHOWERS AND A COUPLE
OF STORMS TO REACH THE I-39 CORRIDOR BY MID MORNING. SOME GUIDANCE
MEMBERS SUGGEST SHOWERS AND STORMS COULD LINGER INTO THE MID
AFTERNOON HOURS BUT THINKING THEY WILL DISSIPATE BY THE EARLY
AFTERNOON.
HIGH CLOUDS WILL BE OVERHEAD AND MAY LIMIT HEATING A BIT...AS SUCH
LEFT HIGH TEMPS TODAY IN THE UPPER 70S.
MULTIPLE ROUNDS OF STORMS ARE EXPECTED WITH THE SECOND ROUND
SPREADING SOUTH THIS EVENING. THE LOW OVER THE PLAINS WILL WEAKEN AS
IT PUSHES EAST AND FORM AN OPEN TROUGH. THE LOWS WARM FRONT WILL
APPROACH THE REGION TONIGHT AND EXPECTING STORMS AHEAD OF IT. THE
NOSE OF THE LOW LEVEL JET WILL ALSO BE OVER NORTHWEST IL THIS
EVENING PROVIDING ADDITIONAL LIFT. CAPE WILL BE LIMITED WITH
MODEL SOUNDINGS SHOWING SHALLOW AREAS OF CAPE AT 1000 J/KG OR LESS.
PWAT VALUES WILL BE AROUND 1.9 INCHES SO TORRENTIAL DOWNPOURS ARE
THE MOST LIKELY HAZARD.
SATURDAY...
THE PLAINS LOW/TROUGH MOVES OVER THE MIDWEST WITH SATURDAY
HAVING THE BEST CHANCE FOR SEVERE WEATHER ESPECIALLY SOUTH OF I-88.
PWAT VALUES REMAIN HIGH AROUND 1.8 INCHES IN THE MORNING AND THEN
INCREASE TO 2-2.3 INCHES SOUTH OF I-80 SATURDAY AFTERNOON. CAPE
VALUES WILL BE MUCH MORE HEALTHY IN THE 3000 J/KG RANGE ESPECIALLY
ALONG AND SOUTH OF THE I-80 CORRIDOR. EXPECTING STORMS TO FIRE
ALONG THE LOWS COLD FRONT SATURDAY AFTERNOON AND EVENING WITH THE
CHANCES OF SHOWERS AND STORMS INCREASING AS YOU HEAD SOUTH. SOME OF
THESE STORMS MAY BE SEVERE WITH TORRENTIAL DOWNPOURS. HAIL AND WIND
LOOK TO BE THE MAIN SEVERE THREATS.
SATURDAY WILL FEEL UNPLEASANT TO MANY WITH HIGHS IN THE UPPER 80S
AND HIGH DEWPOINTS. MAX HEAT INDICES WILL BE IN THE 90S...WITH MID
TO UPPER 90 HEAT INDICES EXPECTED SOUTH OF I-80.
SUNDAY...
THE LOW OVER CANADA DRIFTS SOUTHEAST MOVING OVER WISCONSIN SUNDAY.
ADDITIONAL THUNDERSTORMS ARE POSSIBLE NORTH OF THE I-80
CORRIDOR...WITH THE BEST CHANCES ALONG THE IL/WI STATE LINE. THE
STORMS PUSH EAST OF THE CWA IN THE EVENING. COOLER AIR ASSOCIATED
WITH THE LOW ALSO SPREAD SOUTH WITH HIGHS ON SUNDAY ONLY EXPECTED TO
GET INTO THE LOW TO MID 80S. OVERNIGHT LOWS WILL BE AROUND
60...EXCEPT FOR DOWNTOWN WHICH WILL BE IN THE LOW 60S.
MONDAY THROUGH THURSDAY...
WE REMAIN UNDER THE UPPER LEVEL TROUGH THROUGH NEXT WEEK WITH A
SURFACE HIGH MOVING OVER THE REGION BY MID WEEK. THERE ARE
OCCASIONAL CHANCES OF SHOWERS AND STORMS BUT NONE OF THOSE CHANCES
LOOK ALL THAT IMPRESSIVE AT THIS POINT. THE BIGGER STORY WILL BE
ANOTHER EXTENDED PERIOD OF BELOW NORMAL TEMPS...ALTHOUGH
TEMPERATURES WILL BE SLOWLY RISING THROUGH THE END OF THE FORECAST
PERIOD.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SOUTH WINDS GUSTING AROUND 20 KT THIS AFTERNOON.
* POTENTIAL FOR A FEW SCATTERED SHRA THIS AFTERNOON.
* CHANCE OF TSRA INCREASES LATE TONIGHT.
* PERIOD OF MVFR CIG/FOG POSSIBLE EARLY SATURDAY.
* WIND DIRECTION SOMEWHAT VARIABLE SAT MORNING.
RATZER
//DISCUSSION...UPDATED 18Z...
LOW PRESSURE WAS OVER EASTERN NEBRASKA AT MIDDAY...WITH A WARM
FRONT EXTENDING SOUTHEAST ACROSS THE LOWER MISSOURI RIVER VALLEY.
CIRCULATION ASSOCIATED WITH A MID-LEVEL DISTURBANCE/REMNANT MCV
OVER SOUTHERN WI WAS PRODUCING SOME RAIN ACROSS WI...BUT ONLY
SPOTTY SHRA INTO NORTHERN FOR THE MOST PART...WHILE A COMPLEX OF
THUNDERSTORMS CONTINUES TO MOVE SOUTHEAST ALONG THE MISSISSIPPI
RIVER INTO WESTERN/SOUTHERN IL. TERMINALS WILL REMAIN IN AN AREA
OF BROAD MOIST ASCENT INTO TONIGHT...WITH NOCTURNAL INCREASE IN
LOW LEVEL JET AND AN APPROACHING MID-LEVEL WAVE EXPECTED TO
EVENTUALLY SHIFT THE ELEVATED WARM FRONTAL ZONE EASTWARD AND
PRODUCE SCATTERED THUNDERSTORM THREAT OVER THE TERMINALS LATER
TONIGHT. PATTERN IS RELATIVELY MESSY HOWEVER...WITH FAIRLY LOW
CONFIDENCE IN TIMING DETAILS BEYOND THE OVERALL TREND AT THIS
TIME. AT THIS TIME HOWEVER...IT APPEARS THAT THE GREATEST
THUNDERSTORM THREAT WILL BE TOWARD/AFTER MIDNIGHT. LOW LEVEL JET
THEN TO BECOME MORE WEST/NORTHWEST BY SATURDAY
MORNING...DECREASING THUNDERSTORM POTENTIAL OVER TERMINALS AFTER
SUNRISE. SOME POTENTIAL WILL EXIST FOR BRIEF PERIOD OF MVFR
CEILING AND SOME GROUND FOG WILL EXIST EARLY SATURDAY MORNING
ESPECIALLY WHERE ORGANIZED RAINS FALL.
SOUTHERLY SURFACE WINDS GUSTING AROUND 20 KT THIS AFTERNOON IN
RESPONSE TO PRESSURE FALLS ACROSS WI/IA...APPARENTLY ENHANCED OVER
WESTERN IL BY WAKE LOW BEHIND MISSISSIPPI VALLEY THUNDERSTORM
COMPLEX. WINDS DIMINISH TONIGHT AFTER SUNSET AS GRADIENT WEAKENS
WITH APPROACH OF SURFACE TROUGH. WINDS SHOULD SHIFT MORE
WEST/NORTHWEST SATURDAY MORNING AS SURFACE TROUGH/COLD FRONT SAGS
SOUTHEAST ACROSS THE AREA...THOUGH GUIDANCE INDICATES SOME
VARIABILITY IN WIND DIRECTION IN WEAK GRADIENT NEAR THE TROUGH.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* LOW CONFIDENCE IN SHRA THIS AFTN/EVENING. MEDIUM CONFIDENCE IN
TSRA LATE TONIGHT.
* MEDIUM CONFIDENCE IN WIND TRENDS THIS AFTERNOON/EVENING. LOW
CONFIDENCE IN WIND DIRECTION DETAILS SATURDAY MORNING.
* LOW CONFIDENCE IN MVFR CIG/VIS DEVELOPMENT LATE TONIGHT/EARLY
SATURDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SMALL CHANCE OF TSRA.
SUNDAY...CHANCE OF TSRA.
MONDAY...VFR LIKELY. STRONG NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-THURSDAY...SLIGHT CHANCE OF TSRA.
MTF
&&
.MARINE...
228 AM CDT
SOUTHERLY FLOW WILL INCREASE OVER THE LAKE TODAY AS HIGH PRESSURE
SCOOTS EASTWARD FROM THE OHIO RIVER VALLEY. THE SURFACE TROUGH
LEADING TO THE INCREASE IN WINDS WILL ARRIVE EARLY
SATURDAY...HOWEVER WEAKEN TO THE POINT WHERE IT WILL NOT SHIFT THE
WINDS MUCH IF ANY FROM THE SOUTH-SOUTHWEST. THE LOW PRESSURE
DRIVING THIS TROUGH WILL EVOLVE OVER THE LAKE ON SUNDAY TURNING
WINDS NORTHERLY AND DRIVING A SHARP INCREASE IN SPEEDS SUNDAY
NIGHT AND PERSISTING INTO MONDAY. FOR JULY STANDARDS THESE WIND
SPEEDS ONCE AGAIN WILL BE QUITE STRONG WITH EVEN POSSIBLY SOME
GALE FORCE NORTHERLY GUSTS LATE SUNDAY NIGHT INTO MONDAY MORNING.
WITH ONCE AGAIN A LONG FETCH WAVES SHOULD REACH HEIGHTS OF OVER 6
FT OVER MUCH OF THE LAKE WITH EVEN POSSIBLY UP TO 10 FT AGAIN
ACROSS THE FAR SOUTH...PRIMARILY NEAR THE INDIANA SHORE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
1251 PM CDT Fri Jul 25 2014
.DISCUSSION...
ISSUED 1043 AM CDT Fri Jul 25 2014
Already did a major update to the forecast today for more cloud
cover along with much higher chances of showers along with
isolated thunderstorms for areas west of I-57 into early
afternoon. Continued a chance of showers and thunderstorms during
mid/late afternoon over central IL with just slight chances in
southeast IL while far southeast IL near Lawrence county to likely
stay dry today. Trimmed highs down a bit into upper 70s to around
80 degrees due to more showers and clouds over central IL.
MCS over eastern IA, northeast MO and nw half of IL has held
together longer than earlier expected as it tracked se to along
I-72 by late morning. Just isolated thunderstorms west of I-55
while more numerous thunderstorms and heavier rains have been on
western edge of MCS over ne MO and se IA. SPC has 5% risk of large
hail and damaging wind gusts nw of a Shelbville to Tuscola line
today so severe threat quite low today.
12Z ILX sounding showing a lot of dry air below 650 mb so this
should weaken the convection into this afternoon as it continues
moving se toward I-70. Think HRRR model is holding onto convection
too long as it moves it into southeast IL by mid afternoon. NAM
and RUC/RAP model on the other hand appears too quick diminishing
convection during early afternoon. Will blend between the wetter
HRRR and drier NAM/RUC models for the afternoon forecast.
Southerly winds increasing to 10-15 mph this afternoon between
1021 mb high pressure over WV and ridging into the ohio river
valley and 1006 mb low pressure in eastern SD/NE to bring in a bit
more humid air into central IL this afternoon. Dewpoints currently
in the upper 50s to around 60F rising to between 60-65F during the
afternoon and highest west of the IL river.
07
&&
.AVIATION...
ISSUED 1250 PM CDT Fri Jul 25 2014
MCS over central IL and ne MO with widespread showers and isolated
thunderstorms will gradually weaken during the afternoon as cap
increases and low level jet weakens. Showers have just passed se of
PIA and will end at BMI in next hour and along I-72 during mid
afternoon. MVFR ceilings and vsbys to occur at times with rain
showers with isolated thunderstorms possible especially at SPI and
possibly DEC next hour or so. Carried VCSH during mid afternoon
until sunset across central IL. Models have differ solutions
tonight and Sat morning with NAM model generally dry while RUC has
qpf just ne of BMI & CMI after 08Z/3 am tonight. Kept tafs dry
after dusk tonight into Sat morning and feel best chances of
convection will develop during Saturday afternoon as frontal
boundary drops southward toward I-72 into very unstable tropical
airmass. SSW winds 7-13 kts this afternoon and near or just below
10 kts tonight veer more sw on Sat morning. Wind shift with front
dropping south to occur after 18Z Sat especially at northern taf
sites of PIA and BMI.
07
&&
.PREV DISCUSSION...
ISSUED 247 AM CDT Fri Jul 25 2014
Illinois remains on the periphery of high pressure centered over
Ohio early this morning. To our northwest, convection has been
ramping up quickly over the last couple hours in central and
northwest Iowa along a warm front, as the low level jet increases
from the central Plains. The initial concern for this forecast
package involves how much of this convection will affect our area
today. However, the main forecast issue is with severe weather
potential Saturday afternoon and evening.
SHORT TERM...Today through Saturday Night:
The track of this developing thunderstorm cluster has necessitated
some noticeable changes to the going forecast for today. Earlier
grids mainly had the north half affected by the overnight
convection. Latest high-res models are all indicating a
southeast track, which would favor the western parts of the CWA.
However, very dry conditions above 850 mb were observed on our
evening sounding, and LAPS soundings for Peoria and Springfield at
1 am still showed a sizable dry wedge around 800 mb. Model
soundings show this eroding somewhat by mid morning but not
completely going away, so eastward extent is still a bit in
question. Will have the highest PoP`s from around Rushville to
Jacksonville, with lower chances spreading eastward as far as
I-57. Rain chances should be diminishing during the afternoon as
the atmosphere becomes more capped.
Evening models in general agreement with a shortwave tracking
along the periphery of the upper ridge to our southwest, but
convective alignment is more variable. The general consensus is
for a convective complex to develop to our north by late evening.
The ECMWF and GEM track this southeast and just brush by the
forecast area, while the NAM and GFS show some development
extending southwest along a frontal boundary into Kansas. Have not
made much change here at this point, since leftover boundaries
from the daytime activity may also contribute and are not
adequately handled by the synoptic models.
The frontal boundary will likely hang up somewhere in the I-72
vicinity on Saturday. Have gone with only slight chance PoP`s
during the morning, then increased them to around 30-40% in the
afternoon as the cap starts to erode. Very unstable conditions
will be developing, as dew points rise into the mid 70s and yield
CAPE values well over 3000 J/kg. 0-6km shear around 35 knots is
progged by evening, when the best storm chances in our area are
likely. Latest SPC Day2 outlook shows 30% severe probabilities
over the entire forecast area, with damaging winds favored.
Precipitable waters rising to just over 2 inches will also result
in locally heavy rains, and the ECMWF and GFS indicate some
training echoes could also be a concern.
Some secondary concerns also exist on Saturday for heat advisory
potential. With dew points rising into the mid 70s, am expecting
heat index values of 100-102 over most areas except perhaps along
and north of I-74. This is just shy of the 105F criteria for this
area.
LONG TERM...Sunday through Thursday:
Any lingering rain on Sunday will likely be in the morning, before
a cold front passes. This will be ahead of an upper low, currently
entering southwest Saskatchewan, that will be opening up as it
drops southeast through the Great Lakes region. This will evolve
into a broad upper trough that will dominate the eastern U.S.
throughout the week, bringing another period of cooler conditions.
Monday is likely to be the coolest day, with highs mainly in the
mid 70s, and comfortable humidity levels to persist much of the
work week.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1121 AM CDT FRI JUL 25 2014
.DISCUSSION...
324 AM CDT
SYNOPSIS...A TRICKY UNSETTLED FORECAST IS EXPECTED TODAY THROUGH
SUNDAY. THEN THINGS QUIET DOWN FOR THE BEGINNING OF THE WORK WEEK.
SATURDAY WILL BE THE WARMEST DAY IN THE FORECAST WITH HIGHS NEAR
90. TEMPS THEN FALL TO BELOW NORMAL SUNDAY AND SLOWLY BEGIN TO
CLIMB BACK TO NEAR 80 BY LATE NEXT WEEK.
TODAY AND TONIGHT...
AN UPPER LEVEL HIGH IS OVER THE SOUTHWEST U.S. AND SOUTHERN PLAINS
WHILE LOW PRESSURE IS OVER THE ALBERTA/SASKATCHEWAN BORDER. THE
HIGH WILL SLOWLY RETROGRADE THROUGH MONDAY AFTERNOON TO OVER THE SW
U.S. WHILE THE LOW PASSES OVER LAKE MICHIGAN SUNDAY EVENING. AT THE
SURFACE HIGH PRESSURE IS OVER THE OHIO RIVER VALLEY AND IT WILL MOVE
OFF THE ATLANTIC COAST TONIGHT. THERE ARE TWO SURFACE LOWS...ONE
OVER THE NORTHERN PLAINS AND THE SECOND CO-LOCATED WITH THE UPPER
LEVEL LOW OVER THE ALBERTA/SASKATCHEWAN BORDER.
CONVECTION IS ONGOING OVER WEST CENTRAL MINNESOTA AND IOWA VERY
EARLY THIS MORNING. THE STORMS WILL BE MOVING INTO A MORE STABLE
ENVIRONMENT AND THE LOW LEVEL JET WILL ALSO BE WEAKENING AS IT
PUSHES EAST. THERE IS HIGH CONFIDENCE THAT THE STORMS OVER IOWA WILL
WEAKEN AS THEY APPROACH THE CWA...BUT EXPECTING SHOWERS AND A COUPLE
OF STORMS TO REACH THE I-39 CORRIDOR BY MID MORNING. SOME GUIDANCE
MEMBERS SUGGEST SHOWERS AND STORMS COULD LINGER INTO THE MID
AFTERNOON HOURS BUT THINKING THEY WILL DISSIPATE BY THE EARLY
AFTERNOON.
HIGH CLOUDS WILL BE OVERHEAD AND MAY LIMIT HEATING A BIT...AS SUCH
LEFT HIGH TEMPS TODAY IN THE UPPER 70S.
MULTIPLE ROUNDS OF STORMS ARE EXPECTED WITH THE SECOND ROUND
SPREADING SOUTH THIS EVENING. THE LOW OVER THE PLAINS WILL WEAKEN AS
IT PUSHES EAST AND FORM AN OPEN TROUGH. THE LOWS WARM FRONT WILL
APPROACH THE REGION TONIGHT AND EXPECTING STORMS AHEAD OF IT. THE
NOSE OF THE LOW LEVEL JET WILL ALSO BE OVER NORTHWEST IL THIS
EVENING PROVIDING ADDITIONAL LIFT. CAPE WILL BE LIMITED WITH
MODEL SOUNDINGS SHOWING SHALLOW AREAS OF CAPE AT 1000 J/KG OR LESS.
PWAT VALUES WILL BE AROUND 1.9 INCHES SO TORRENTIAL DOWNPOURS ARE
THE MOST LIKELY HAZARD.
SATURDAY...
THE PLAINS LOW/TROUGH MOVES OVER THE MIDWEST WITH SATURDAY
HAVING THE BEST CHANCE FOR SEVERE WEATHER ESPECIALLY SOUTH OF I-88.
PWAT VALUES REMAIN HIGH AROUND 1.8 INCHES IN THE MORNING AND THEN
INCREASE TO 2-2.3 INCHES SOUTH OF I-80 SATURDAY AFTERNOON. CAPE
VALUES WILL BE MUCH MORE HEALTHY IN THE 3000 J/KG RANGE ESPECIALLY
ALONG AND SOUTH OF THE I-80 CORRIDOR. EXPECTING STORMS TO FIRE
ALONG THE LOWS COLD FRONT SATURDAY AFTERNOON AND EVENING WITH THE
CHANCES OF SHOWERS AND STORMS INCREASING AS YOU HEAD SOUTH. SOME OF
THESE STORMS MAY BE SEVERE WITH TORRENTIAL DOWNPOURS. HAIL AND WIND
LOOK TO BE THE MAIN SEVERE THREATS.
SATURDAY WILL FEEL UNPLEASANT TO MANY WITH HIGHS IN THE UPPER 80S
AND HIGH DEWPOINTS. MAX HEAT INDICES WILL BE IN THE 90S...WITH MID
TO UPPER 90 HEAT INDICES EXPECTED SOUTH OF I-80.
SUNDAY...
THE LOW OVER CANADA DRIFTS SOUTHEAST MOVING OVER WISCONSIN SUNDAY.
ADDITIONAL THUNDERSTORMS ARE POSSIBLE NORTH OF THE I-80
CORRIDOR...WITH THE BEST CHANCES ALONG THE IL/WI STATE LINE. THE
STORMS PUSH EAST OF THE CWA IN THE EVENING. COOLER AIR ASSOCIATED
WITH THE LOW ALSO SPREAD SOUTH WITH HIGHS ON SUNDAY ONLY EXPECTED TO
GET INTO THE LOW TO MID 80S. OVERNIGHT LOWS WILL BE AROUND
60...EXCEPT FOR DOWNTOWN WHICH WILL BE IN THE LOW 60S.
MONDAY THROUGH THURSDAY...
WE REMAIN UNDER THE UPPER LEVEL TROUGH THROUGH NEXT WEEK WITH A
SURFACE HIGH MOVING OVER THE REGION BY MID WEEK. THERE ARE
OCCASIONAL CHANCES OF SHOWERS AND STORMS BUT NONE OF THOSE CHANCES
LOOK ALL THAT IMPRESSIVE AT THIS POINT. THE BIGGER STORY WILL BE
ANOTHER EXTENDED PERIOD OF BELOW NORMAL TEMPS...ALTHOUGH
TEMPERATURES WILL BE SLOWLY RISING THROUGH THE END OF THE FORECAST
PERIOD.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* SOUTH WINDS GUSTING NEAR 20 KT AT TIMES INTO THIS AFTERNOON.
* SCATTERED LIGHT SHRA THROUGH EARLY AFTERNOON...WITH A BREAK
EXPECTED LATE AFTERNOON/EARLY EVENING.
* CHANCE OF TSRA...MAINLY TONIGHT.
RATZER
//DISCUSSION...UPDATED 16Z...
MID-LEVEL DISTURBANCE MOVING SOUTHEAST ACROSS SOUTHERN WI/NORTHERN
IL THROUGH MID-AFTERNOON WILL BRING POTENTIAL FOR SCATTERED
SHOWERS FROM VFR MID-DECK CIGS. TIMING OF MID-LEVEL CIRCULATION IN
RADAR APPROACHING KDLL SUGGESTS THIS FEATURE WILL PASS ACROSS
WESTERN LAKE MICHIGAN SHORE AROUND 21Z WITH A DECREASE IN SHRA
COVERAGE AFTER THAT TIME. IT APPEARS LITTLE THREAT OF THUNDER WILL
EXIST AT TERMINALS...WITH BETTER CHANCES REMAINING WEST AND FOCUSED
FROM EASTERN IOWA SOUTH ALONG THE MISSISSIPPI RIVER.
SURFACE PRESSURE FALLS ACROSS WI/NORTHERN IL AT 16Z IN ASSOCIATION
WITH ABOVE MENTIONED DISTURBANCE HELPING TO INCREASE WINDS AND
BACK THEM A BIT MORE SOUTHERLY 190-180 DEG. 1-MIN ASOS DATA
SHOWING SOME GUSTS ALREADY APPROACHING 20 KT AT ORD.
RATZER
PREVIOUS DISCUSSION FROM 12Z...
MOIST ADVECTION ALOFT ACROSS IA/NW IL/WI CONTINUES TO SPRING
SCATTERED SHOWERS WITH A FEW STORMS EARLY THIS MORNING. THE MAIN
DRIVING UPPER DISTURBANCE IS IN CENTRAL IA AND WILL CONTINUE TO
MOVE SOUTHEAST. IMMEDIATELY EAST OF THIS SHOULD BE THE MORE
WIDESPREAD SHOWER/STORM ACTIVITY...WITH ONLY ISOLATED/SCATTERED
FURTHER NORTHEAST NEAR THE CHICAGOLAND TAF SITES.
WHILE THE UPPER DISTURBANCE MOVES BEYOND THE AREA IN THE
AFTERNOON...THERE WILL STILL BE MOIST ADVECTION ALONG WITH THE
APPROACH OF A SURFACE TROUGH...SO CANNOT RULE OUT SOME SHRA/TSRA
ACTIVITY. HOWEVER OVERALL SUPPORT IS LOW AND THUS HAVE TAFS MAINLY
DRY IN THE AFTERNOON. THE MORE FAVORABLE CHANCES FOR PRECIP WILL
ARRIVE AFTER DARK AS THE NEXT UPPER DISTURBANCE MOVES ACROSS THE
AREA AND INTO A VERY MOIST ENVIRONMENT. CONTINUE TO MENTION
PROB30S FOR TSRA DURING THE MID/LATE EVE INTO EARLY OVERNIGHT.
SOME GUIDANCE DOES INDICATE MVFR CONDITIONS IN THE IMMEDIATE WAKE
OF THIS AND BELIEVE IF IT DOES RAIN WITH DIMINISHING FLOW LATE
TONIGHT THEN THERE COULD VERY WELL BE SOME LOWERED VISBYS/CIGS
INTO EARLY SATURDAY MORNING.
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM IN SHRA TRENDS. CIGS/VIS SHOULD REMAIN VFR.
* MEDIUM CONFIDENCE IN WIND TRENDS.
* LOW IN TSRA OCCURRING TONIGHT. MEDIUM IN TIMING IF IT WERE TO
OCCUR.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SMALL CHANCE OF TSRA.
SUNDAY...CHANCE OF TSRA.
MONDAY...VFR LIKELY. STRONG NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-THURSDAY...SLIGHT CHANCE OF TSRA.
MTF
&&
.MARINE...
228 AM CDT
SOUTHERLY FLOW WILL INCREASE OVER THE LAKE TODAY AS HIGH PRESSURE
SCOOTS EASTWARD FROM THE OHIO RIVER VALLEY. THE SURFACE TROUGH
LEADING TO THE INCREASE IN WINDS WILL ARRIVE EARLY
SATURDAY...HOWEVER WEAKEN TO THE POINT WHERE IT WILL NOT SHIFT THE
WINDS MUCH IF ANY FROM THE SOUTH-SOUTHWEST. THE LOW PRESSURE
DRIVING THIS TROUGH WILL EVOLVE OVER THE LAKE ON SUNDAY TURNING
WINDS NORTHERLY AND DRIVING A SHARP INCREASE IN SPEEDS SUNDAY
NIGHT AND PERSISTING INTO MONDAY. FOR JULY STANDARDS THESE WIND
SPEEDS ONCE AGAIN WILL BE QUITE STRONG WITH EVEN POSSIBLY SOME
GALE FORCE NORTHERLY GUSTS LATE SUNDAY NIGHT INTO MONDAY MORNING.
WITH ONCE AGAIN A LONG FETCH WAVES SHOULD REACH HEIGHTS OF OVER 6
FT OVER MUCH OF THE LAKE WITH EVEN POSSIBLY UP TO 10 FT AGAIN
ACROSS THE FAR SOUTH...PRIMARILY NEAR THE INDIANA SHORE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
1043 AM CDT Fri Jul 25 2014
.DISCUSSION...
ISSUED 1043 AM CDT Fri Jul 25 2014
Already did a major update to the forecast today for more cloud
cover along with much higher chances of showers along with
isolated thunderstorms for areas west of I-57 into early
afternoon. Continued a chance of showers and thunderstorms during
mid/late afternoon over central IL with just slight chances in
southeast IL while far southeast IL near Lawrence county to likely
stay dry today. Trimmed highs down a bit into upper 70s to around
80 degrees due to more showers and clouds over central IL.
MCS over eastern IA, northeast MO and nw half of IL has held
together longer than earlier expected as it tracked se to along
I-72 by late morning. Just isolated thunderstorms west of I-55
while more numerous thunderstorms and heavier rains have been on
western edge of MCS over ne MO and se IA. SPC has 5% risk of large
hail and damaging wind gusts nw of a Shelbville to Tuscola line
today so severe threat quite low today.
12Z ILX sounding showing a lot of dry air below 650 mb so this
should weaken the convection into this afternoon as it continues
moving se toward I-70. Think HRRR model is holding onto convection
too long as it moves it into southeast IL by mid afternoon. NAM
and RUC/RAP model on the other hand appears too quick diminishing
convection during early afternoon. Will blend between the wetter
HRRR and drier NAM/RUC models for the afternoon forecast.
Southerly winds increasing to 10-15 mph this afternoon between
1021 mb high pressure over WV and ridging into the ohio river
valley and 1006 mb low pressure in eastern SD/NE to bring in a bit
more humid air into central IL this afternoon. Dewpoints currently
in the upper 50s to around 60F rising to between 60-65F during the
afternoon and highest west of the IL river.
07
&&
.AVIATION...
ISSUED 657 AM CDT Fri Jul 25 2014
Mainly VFR conditions are expected over central and southeast
Illinois today and tonight. A weakening thunderstorm system will
move across central AZ today bringing increasing low and mid-
level cloud cover along with scattered showers and isolated
thunderstorms. The best chances for showers and thunderstorms
until 18Z will be from KSPI-KBMI northwestward. Have placed
temporary MVFR conditions in the KPIA TAF, but left out of other
area TAFS due to low probabilities and coverage of MVFR
cigs/vsbys. Another disturbance tracking into the area this
evening is expected to bring more showers and thunderstorms
overnight. Winds generally southerly around 10 KTS from 15Z through
12Z Saturday.
Onton
&&
.PREV DISCUSSION...
ISSUED 247 AM CDT Fri Jul 25 2014
Illinois remains on the periphery of high pressure centered over
Ohio early this morning. To our northwest, convection has been
ramping up quickly over the last couple hours in central and
northwest Iowa along a warm front, as the low level jet increases
from the central Plains. The initial concern for this forecast
package involves how much of this convection will affect our area
today. However, the main forecast issue is with severe weather
potential Saturday afternoon and evening.
SHORT TERM...Today through Saturday Night:
The track of this developing thunderstorm cluster has necessitated
some noticeable changes to the going forecast for today. Earlier
grids mainly had the north half affected by the overnight
convection. Latest high-res models are all indicating a
southeast track, which would favor the western parts of the CWA.
However, very dry conditions above 850 mb were observed on our
evening sounding, and LAPS soundings for Peoria and Springfield at
1 am still showed a sizable dry wedge around 800 mb. Model
soundings show this eroding somewhat by mid morning but not
completely going away, so eastward extent is still a bit in
question. Will have the highest PoP`s from around Rushville to
Jacksonville, with lower chances spreading eastward as far as
I-57. Rain chances should be diminishing during the afternoon as
the atmosphere becomes more capped.
Evening models in general agreement with a shortwave tracking
along the periphery of the upper ridge to our southwest, but
convective alignment is more variable. The general consensus is
for a convective complex to develop to our north by late evening.
The ECMWF and GEM track this southeast and just brush by the
forecast area, while the NAM and GFS show some development
extending southwest along a frontal boundary into Kansas. Have not
made much change here at this point, since leftover boundaries
from the daytime activity may also contribute and are not
adequately handled by the synoptic models.
The frontal boundary will likely hang up somewhere in the I-72
vicinity on Saturday. Have gone with only slight chance PoP`s
during the morning, then increased them to around 30-40% in the
afternoon as the cap starts to erode. Very unstable conditions
will be developing, as dew points rise into the mid 70s and yield
CAPE values well over 3000 J/kg. 0-6km shear around 35 knots is
progged by evening, when the best storm chances in our area are
likely. Latest SPC Day2 outlook shows 30% severe probabilities
over the entire forecast area, with damaging winds favored.
Precipitable waters rising to just over 2 inches will also result
in locally heavy rains, and the ECMWF and GFS indicate some
training echoes could also be a concern.
Some secondary concerns also exist on Saturday for heat advisory
potential. With dew points rising into the mid 70s, am expecting
heat index values of 100-102 over most areas except perhaps along
and north of I-74. This is just shy of the 105F criteria for this
area.
LONG TERM...Sunday through Thursday:
Any lingering rain on Sunday will likely be in the morning, before
a cold front passes. This will be ahead of an upper low, currently
entering southwest Saskatchewan, that will be opening up as it
drops southeast through the Great Lakes region. This will evolve
into a broad upper trough that will dominate the eastern U.S.
throughout the week, bringing another period of cooler conditions.
Monday is likely to be the coolest day, with highs mainly in the
mid 70s, and comfortable humidity levels to persist much of the
work week.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
217 PM EDT FRI JUL 25 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 248 AM EDT FRI JUL 25 2014
DRY AND COMFORTABLE WEATHER WILL GIVE WAY TO WARM...HUMID AND
STORMY WEATHER THIS WEEKEND AS A COLD FRONT GRADUALLY DROPS
SOUTHEAST ACROSS THE AREA. SEVERE STORMS ARE A POSSIBILITY BY LATE
SATURDAY. MEANWHILE...AN UPPER WAVE WILL DROP SOUTHEAST ACROSS THE
LOWER GREAT LAKES SUNDAY NIGHT PUSHING THE FRONT TO THE SOUTHERN
STATES AND ALLOWING FOR MORE BELOW NORMAL TEMPERATURES NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1036 AM EDT FRI JUL 25 2014
HIGH LEVEL CLOUD DEBRIS EXPANDING INTO THE REGION THIS MORNING
FROM ONGOING CONVECTION OVER THE MID MISSISSIPPI VALLEY. TEMPS
WERE MAINLY IN THE 60S AT 14Z.
CONVECTION ACROSS EASTERN IOWA AND WESTERN ILLINOIS EXPECTED TO
PROPAGATE SOUTHEAST ALONG THE MISSISSIPPI RIVER IN CLOSER
PROXIMITY TO THE WARM FRONT. CENTRAL INDIANA REMAINS UNDER THE
PROTECTION OF THE SLOWLY DEPARTING HIGH PRESSURE...WITH
MESOANALYSIS SHOWING PWATS STILL BELOW 1 INCH AND AN ABUNDANCE OF
DRY AIR BELOW 15KFT. AIRMASS WILL SLOWLY MOISTEN AS THE AFTERNOON
PROGRESSES AND THE WARM FRONT APPROACHES THE WABASH VALLEY.
HOWEVER...CURRENT HRRR LOOKS FAR TOO AGGRESSIVE IN SPREADING
PRECIP INTO THE REGION OVER THE NEXT 6 HOURS...ESPECIALLY
CONSIDERING THE AMBIENT AIRMASS. MID AND HIGH LEVEL CLOUDS WILL BE
THE PRIMARY IMPACT...LIMITING SUNSHINE AND TEMP RISES A BIT MORE
THAN EARLIER THOUGHT. HAVE THEREFORE BUMPED HIGHS DOWN A COUPLE
DEGREES AND INCREASED CLOUD COVERAGE THROUGH THE REMAINDER OF THE
DAY. ANY PRECIP IS LIKELY TO HOLD OFF IN FAR NORTHWEST COUNTIES
UNTIL EARLY EVENING WITH THE APPROACH OF THE FRONT.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 248 AM EDT FRI JUL 25 2014
A CONVECTIVELY ACTIVE SHORT TERM WILL PROVIDE MANY CHALLENGES TO THE
FORECAST..NOT THE LEAST OF WHICH IS THE POTENTIAL FOR SEVERE WEATHER
AND HEAVY RAIN SATURDAY PM...ILLUSTRATED BY THE DAY2 SPC OUTLOOK.
MODELS ARE IN GOOD AGREEMENT THAT A SHARP UPPER TROUGH WILL DROP
SOUTHEAST ACROSS THE EASTERN GREAT LAKES AND OHIO ON SUNDAY NIGHT
WHICH WILL FORCE A STRONG COLD FRONT SOUTHEAST ACROSS THE FORECAST
AREA. THE FRONT WILL INTERACT WITH INCREASING MOISTURE AND
INSTABILITY AND RESULT IN THUNDERSTORM CHANCES STARTING FRIDAY NIGHT
AND CONTINUING THROUGH SUNDAY NIGHT. THE BEST CHANCES WILL BE
SATURDAY NIGHT AND SUNDAY MORNING AS A LOW LEVEL JET SETTLES ACROSS
SOUTH CENTRAL INDIANA RESULTING IN PRECIPITABLE WATER VALUES AROUND
2 INCHES THERE. IN ADDITION...UPPER JET WILL STRETCH OUT ACROSS THE
LOWER GREAT LAKES WITH EMBEDDED JET MAXIMA AIDING IN RAINFALL
EFFICIENCY AND SEVERE POTENTIAL. SO...WITH ABUNDANT
FORCING...INSTABILITY AND MOISTURE...POTENTIAL SEVERE MCS ACTIVITY
LOOKS LIKE A GOOD BET SATURDAY NIGHT WITH DAMAGING WINDS AND HEAVY
RAIN THE MAIN CONCERNS. IF THE ATMOSPHERE CAN RECOVER ENOUGH FROM
THE FRIDAY NIGHT AND SATURDAY NIGHT STORMS...COULD ALSO SEE A FEW
SEVERE STORMS DURING THE AFTERNOON AND EVENING HOURS SATURDAY AND
SUNDAY BEFORE THE COLD FRONT MOVES THROUGH SUNDAY NIGHT.
SIDED CLOSER TO THE COOLER 00Z NAM MOS FOR AFTERNOON HIGHS AS THE
00Z GFS AND JUL 24 00Z ECM LOOK TOO WARM BY SATURDAY CONSIDERING
CLOUD COVER AND EFFECT OF FRIDAY NIGHT AND SATURDAY MORNING
CONVECTION.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 216 PM EDT FRI JUL 25 2014
THE LONG TERM WILL START OUT DRY AND COOL WITH HIGH PRESSURE
BUILDING OVER THE AREA. WITH AN UPPER TROUGH OVER THE EASTERN U.S.
COOLER THAN NORMAL CONDITIONS WILL CONTINUE THROUGH THE LONG TERM
WITH TEMPERATURES SLOWLY WARMING BUT STILL NOT GETTING BACK UP TO
NORMAL. WEAK SHORTWAVES MOVING THROUGH THE MAIN NORTHWEST FLOW
PATTERN COULD BRING IN SMALL THUNDERSTORM CHANCES WEDNESDAY THROUGH
FRIDAY ESPECIALLY ACROSS THE NORTHERN COUNTIES. WITH A WIDE SPREAD
IN ENSEMBLE SOLUTIONS FOR THAT TIME WILL LEAVE THE ALLBLEND SLIGHT
TO LOW CHANCE POPS ALONE.
&&
.AVIATION /DISCUSSION FOR 251800Z TAF ISSUANCE/...
ISSUED AT 115 PM EDT FRI JUL 25 2014
CURRENTLY LOOKING VFR THROUGH THE PERIOD. LARGE AREA OF SHOWERS
AND THUNDERSTORMS OVER CENTRAL ILLINOIS THROUGH EASTERN MISSOURI
HAS BEEN WEAKENING AND CONTINUING TO HEAD TO THE SOUTHEAST. BASED
ON CURRENT MOTIONS AND LACK OF MOISTURE OVER INDIANA THINK THIS
TREND WILL CONTINUE...BUT COULD SEE A BRIEF PERIOD OF SHOWERS AT
KHUF SOMETIME AROUND 20Z OR SO. DON/T THINK THIS WILL IMPACT
FLIGHT CATEGORY. ELSEWHERE EXPECT INCREASING CLOUD COVER BUT WITH
VFR CEILINGS. AT KLAF MODELS ARE SHOWING POTENTIAL FOR SOME
THUNDERSTORMS DURING THE OVERNIGHT AND KEPT THESE AS A VCTS FROM
8-14Z WITH STILL A DECENT AMOUNT OF UNCERTAINTY ON EXACT LOCATION
AND TIMING. EXPECT TO SEE MORE WIDESPREAD STORMS OVER THE SITES
LATE SATURDAY NIGHT BUT AT THIS POINT THAT/S OUTSIDE OF THE TAF
PERIOD. WINDS SHOULD REMAIN 5-10 KTS DURING THE OVERNIGHT AND
THINK THIS SHOULD PRECLUDE ANY FOG DEVELOPMENT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...RYAN
SHORT TERM...MK
LONG TERM....CP
AVIATION...CP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
127 PM EDT FRI JUL 25 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 248 AM EDT FRI JUL 25 2014
DRY AND COMFORTABLE WEATHER WILL GIVE WAY TO WARM...HUMID AND
STORMY WEATHER THIS WEEKEND AS A COLD FRONT GRADUALLY DROPS
SOUTHEAST ACROSS THE AREA. SEVERE STORMS ARE A POSSIBILITY BY LATE
SATURDAY. MEANWHILE...AN UPPER WAVE WILL DROP SOUTHEAST ACROSS THE
LOWER GREAT LAKES SUNDAY NIGHT PUSHING THE FRONT TO THE SOUTHERN
STATES AND ALLOWING FOR MORE BELOW NORMAL TEMPERATURES NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1036 AM EDT FRI JUL 25 2014
HIGH LEVEL CLOUD DEBRIS EXPANDING INTO THE REGION THIS MORNING
FROM ONGOING CONVECTION OVER THE MID MISSISSIPPI VALLEY. TEMPS
WERE MAINLY IN THE 60S AT 14Z.
CONVECTION ACROSS EASTERN IOWA AND WESTERN ILLINOIS EXPECTED TO
PROPAGATE SOUTHEAST ALONG THE MISSISSIPPI RIVER IN CLOSER
PROXIMITY TO THE WARM FRONT. CENTRAL INDIANA REMAINS UNDER THE
PROTECTION OF THE SLOWLY DEPARTING HIGH PRESSURE...WITH
MESOANALYSIS SHOWING PWATS STILL BELOW 1 INCH AND AN ABUNDANCE OF
DRY AIR BELOW 15KFT. AIRMASS WILL SLOWLY MOISTEN AS THE AFTERNOON
PROGRESSES AND THE WARM FRONT APPROACHES THE WABASH VALLEY.
HOWEVER...CURRENT HRRR LOOKS FAR TOO AGGRESSIVE IN SPREADING
PRECIP INTO THE REGION OVER THE NEXT 6 HOURS...ESPECIALLY
CONSIDERING THE AMBIENT AIRMASS. MID AND HIGH LEVEL CLOUDS WILL BE
THE PRIMARY IMPACT...LIMITING SUNSHINE AND TEMP RISES A BIT MORE
THAN EARLIER THOUGHT. HAVE THEREFORE BUMPED HIGHS DOWN A COUPLE
DEGREES AND INCREASED CLOUD COVERAGE THROUGH THE REMAINDER OF THE
DAY. ANY PRECIP IS LIKELY TO HOLD OFF IN FAR NORTHWEST COUNTIES
UNTIL EARLY EVENING WITH THE APPROACH OF THE FRONT.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 248 AM EDT FRI JUL 25 2014
A CONVECTIVELY ACTIVE SHORT TERM WILL PROVIDE MANY CHALLENGES TO THE
FORECAST..NOT THE LEAST OF WHICH IS THE POTENTIAL FOR SEVERE WEATHER
AND HEAVY RAIN SATURDAY PM...ILLUSTRATED BY THE DAY2 SPC OUTLOOK.
MODELS ARE IN GOOD AGREEMENT THAT A SHARP UPPER TROUGH WILL DROP
SOUTHEAST ACROSS THE EASTERN GREAT LAKES AND OHIO ON SUNDAY NIGHT
WHICH WILL FORCE A STRONG COLD FRONT SOUTHEAST ACROSS THE FORECAST
AREA. THE FRONT WILL INTERACT WITH INCREASING MOISTURE AND
INSTABILITY AND RESULT IN THUNDERSTORM CHANCES STARTING FRIDAY NIGHT
AND CONTINUING THROUGH SUNDAY NIGHT. THE BEST CHANCES WILL BE
SATURDAY NIGHT AND SUNDAY MORNING AS A LOW LEVEL JET SETTLES ACROSS
SOUTH CENTRAL INDIANA RESULTING IN PRECIPITABLE WATER VALUES AROUND
2 INCHES THERE. IN ADDITION...UPPER JET WILL STRETCH OUT ACROSS THE
LOWER GREAT LAKES WITH EMBEDDED JET MAXIMA AIDING IN RAINFALL
EFFICIENCY AND SEVERE POTENTIAL. SO...WITH ABUNDANT
FORCING...INSTABILITY AND MOISTURE...POTENTIAL SEVERE MCS ACTIVITY
LOOKS LIKE A GOOD BET SATURDAY NIGHT WITH DAMAGING WINDS AND HEAVY
RAIN THE MAIN CONCERNS. IF THE ATMOSPHERE CAN RECOVER ENOUGH FROM
THE FRIDAY NIGHT AND SATURDAY NIGHT STORMS...COULD ALSO SEE A FEW
SEVERE STORMS DURING THE AFTERNOON AND EVENING HOURS SATURDAY AND
SUNDAY BEFORE THE COLD FRONT MOVES THROUGH SUNDAY NIGHT.
SIDED CLOSER TO THE COOLER 00Z NAM MOS FOR AFTERNOON HIGHS AS THE
00Z GFS AND JUL 24 00Z ECM LOOK TOO WARM BY SATURDAY CONSIDERING
CLOUD COVER AND EFFECT OF FRIDAY NIGHT AND SATURDAY MORNING
CONVECTION.
&&
.LONG TERM /MONDAY THROUGH THURSDAY NIGHT/...
ISSUED AT 340 AM EDT FRI JUL 25 2014
SCATTERED RAIN SHOWERS WILL BE POSSIBLE ACROSS CENTRAL INDIANA ON
MONDAY AS AN UPPER LEVEL TROUGH AND ASSOCIATED SURFACE COLD FRONT
DEPART THE AREA. AFTER THAT...HIGH PRESSURE WILL RESULT IN DRY
CONDITIONS THROUGH MID-WEEK. AT THAT POINT...MODELS BECOME
INCONSISTENT FOR THE END OF LONG TERM PERIOD. LATEST REGIONAL
INITIALIZATION IS PICKING UP ON AN UPPER TROUGH FOR THURSDAY...BUT
IS STRUGGLING WITH TIMING. DUE TO THE MODEL INCONSISTENCY...WILL
NOT DEVIATE FROM INITIALIZATION AT THIS TIME WHICH HAS PERIODS OF
SLIGHT CHANCE POPS FOR THURSDAY/THURSDAY NIGHT. TEMPS THROUGH THE
PERIOD WILL BE WELL BELOW NORMAL WITH HIGHS ONLY IN THE 70S AND
LOWS IN THE 50S. TEMPS WILL INCREASE SLIGHTLY BY THE END OF THE
PERIOD...BUT WILL STILL BE BELOW NORMAL.
&&
.AVIATION /DISCUSSION FOR 251800Z TAF ISSUANCE/...
ISSUED AT 115 PM EDT FRI JUL 25 2014
CURRENTLY LOOKING VFR THROUGH THE PERIOD. LARGE AREA OF SHOWERS
AND THUNDERSTORMS OVER CENTRAL ILLINOIS THROUGH EASTERN MISSOURI
HAS BEEN WEAKENING AND CONTINUING TO HEAD TO THE SOUTHEAST. BASED
ON CURRENT MOTIONS AND LACK OF MOISTURE OVER INDIANA THINK THIS
TREND WILL CONTINUE...BUT COULD SEE A BRIEF PERIOD OF SHOWERS AT
KHUF SOMETIME AROUND 20Z OR SO. DON/T THINK THIS WILL IMPACT
FLIGHT CATEGORY. ELSEWHERE EXPECT INCREASING CLOUD COVER BUT WITH
VFR CEILINGS. AT KLAF MODELS ARE SHOWING POTENTIAL FOR SOME
THUNDERSTORMS DURING THE OVERNIGHT AND KEPT THESE AS A VCTS FROM
8-14Z WITH STILL A DECENT AMOUNT OF UNCERTAINTY ON EXACT LOCATION
AND TIMING. EXPECT TO SEE MORE WIDESPREAD STORMS OVER THE SITES
LATE SATURDAY NIGHT BUT AT THIS POINT THAT/S OUTSIDE OF THE TAF
PERIOD. WINDS SHOULD REMAIN 5-10 KTS DURING THE OVERNIGHT AND
THINK THIS SHOULD PRECLUDE ANY FOG DEVELOPMENT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...RYAN
SHORT TERM...MK
LONG TERM....TDUD
AVIATION...CP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1244 PM CDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 1239 PM CDT FRI JUL 25 2014
THE NOCTURNAL THUNDERSTORM COMPLEX HAS ESSENTIALLY MOVED EAST OF
THE AREA. A COMBINATION OF DIFFERENTIAL HEATING AND RESIDUAL
BOUNDARIES HAVE ALLOWED ISOLATED TO SCATTERED CONVECTION TO
DEVELOP BEHIND THE DEPARTING COMPLEX.
FOR THE AFTERNOON SKIES WILL SLOWLY CLEAR ALLOWING TEMPERATURES TO
CLIMB. THE POSSIBILITY DOES EXIST OF SOME ISOLATED LATE AFTERNOON
AND EVENING CONVECTION.
UPDATE ISSUED AT 1041 AM CDT FRI JUL 25 2014
THE CURRENT THUNDERSTORM COMPLEX CONTINUES TO SLOWLY DECAY AS IT
MOVES EAST OF THE MISSISSIPPI. A MESO HIGH OVER NORTHEAST IOWA IS
STARTING TO COLLAPSE WHICH IS CAUSING A PERIOD OF STRONG WINDS ON
THE BACK SIDE OF THE PRECIPITATION.
NEW CONVECTION HAS DEVELOPED ACROSS NORTHERN IOWA WHICH APPEARS TO
BE ASSOCIATED WITH A WEAK THETA E GRADIENT. RECENT RADAR TRENDS
SHOW SOME WEAKENING OF THIS CONVECTION.
THE RAIN WILL END FROM WEST TO EAST THROUGH MID DAY AS WARMER
TEMPERATURES BUILDS IN ALOFT. THE POTENTIAL FOR CONVECTION WILL
HAVE TO BE RE-EVALUATED FOR THE AFTERNOON HOURS.
UPDATE ISSUED AT 700 AM CDT FRI JUL 25 2014
MCS OVER THE DVN CWA EARLY THIS MORNING WITH LOCALLY HEAVY RAINFALL
IN THE SOME OF THE STRONGER STORMS. IR SATELLITE SHOWED WARMING
TOPS IN OUR NORTHERN CWA WHICH ALSO IS INDICATED ON DOPPLER RADAR
WITH A WEAKENING TREND. THE ENTIRE MCS WILL GRADUALLY WEAKEN AS IT
PUSHES SOUTHEAST THIS MORNING AND THE HRRR MESO MODEL SHOWS THE BACK
EDGE OF THE MCS EXITING OUR SE CWA BY 1 PM. MANY AREAS SHOULD PICK
UP 1/4 TO 1/2 INCH OF RAIN WITH ISOLATED 1 INCH POSSIBLE.
&&
.SYNOPSIS...
ISSUED AT 345 AM CDT FRI JUL 25 2014
ELEVATED CONVECTION HAS FIRED IN THE PAST FEW HOURS ACROSS PORTIONS
OF NORTHERN/CENTRAL IA AND INTO WESTERN/SOUTHERN MN. THIS IS OCCURRING
ON THE NOSE OF A 50+ KNOT LOW LEVEL JET ON THE EASTERN EDGE OF A CAPPED
ELEVATED MIXED LAYER. SPC MESO ANALYSIS SHOWS THE BETTER MOISTURE
TRANSPORT IS STILL WEST OF THE DVN CWA WITH THE HIGHEST BULK SHEAR
VALUES IN SOUTHERN MN. PRECIPITABLE WATERS RANGE FROM 2.10 INCHES
IN WESTERN IA TO LESS THAN AN INCH IN NORTHERN IL. IR SATELLITE
LOOPS INDICATE TOPS CONTINUE TO RAPIDLY COOL AS THE THUNDERSTORM
ACTIVITY MOVES SOUTHEAST. A SHORT WAVE TROUGH WAS ALSO LIFTING
EASTWARD ACROSS THE NORTHERN/CENTRAL PLAINS AROUND A CLOSED UPPER
LOW IN SOUTHERN ALBERTA.
A COOL/STABLE SURFACE LAYER WAS NOTED ACROSS THE DVN CWA WITH 3 AM
TEMPERATURES IN THE MID 50S TO MID 60S...WHILE READINGS WERE WELL
INTO THE 70S TO LOWER 80S IN THE CENTRAL/SOUTHERN PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT FRI JUL 25 2014
FORECAST FOCUS ON THUNDERSTORMS MAINLY THIS MORNING AND TEMPERATURES.
TODAY...FORCING AND RAPIDLY INCREASING MOISTURE WILL ALLOW THUNDERSTORMS
TO CONTINUE TO DEVELOP/SPREAD ACROSS MUCH OF THE CWA THIS MORNING ON
THE NOSE OF THE STRONG LOW LEVEL JET...AS IT VEERS INTO THE AREA. DUE
TO THE ELEVATED NATURE OF THE STORMS AND THE COOL/STABLE SURFACE ENVIRONMENT
SEVERE WEATHER IS NOT EXPECTED. FREEZING LEVELS ARE QUITE HIGH AT NEARLY
15K FT. HOWEVER...SOME OF THE STRONGER STORMS MAY PRODUCE FREQUENT LIGHTNING...
SUB-SEVERE HAIL AND LOCALLY HEAVY RAINFALL. LATER THIS MORNING THE LOW
LEVEL JET WILL WEAKEN CONSIDERABLY ALONG WITH THE PASSAGE OF THE SHORT
WAVE TROUGH. A STRENGTHENING CAP WILL ALSO SPREAD EASTWARD INTO THE
CWA. THIS WILL DIMINISH OR END THE THUNDERSTORM ACTIVITY BY AFTERNOON
SO WILL HAVE LIKELY TO CATEGORICAL POPS THIS MORNING AND ONLY SMALL
POPS THIS AFTERNOON. EXPECTING EXTENSIVE CLOUD COVER TO LINGER INTO
THE AFTERNOON ESPECIALLY IN OUR EAST WHILE MORE SUNSHINE DEVELOPS IN
OUR WEST. MODELS REALLY SURGE THE WARM 850 MB TEMPERATURES INTO OUR
WESTERN CWA WITH +20C NOTED LATER IN THE AFTERNOON. I WILL FORECAST
MAXIMUM TEMPERATURES RANGING FROM THE MID 80S SW TO THE MID 70S NE.
HOWEVER...DEPENDING ON AMOUNT OF LINGERING CLOUDS (OR LACK OF) THIS
AFTERNOON THESE READINGS MAY NEED TO BE RE-VISITED.
TONIGHT...STRONG CAPPING ENVIRONMENT OVERSPREADS THE CWA EXCEPT
POSSIBLY OUR FAR EASTERN CWA. MODELS INSIST ON DEVELOPING CONVECTION
IN OUR EASTERN CWA AS THE LOW LEVEL JET STRENGTHENS AGAIN...BUT THERE
IS THE POTENTIAL THE STORMS MAY END UP FIRING EAST OF THE DVN CWA.
WILL HAVE CHANCE POPS TO COVER THIS SCENARIO BUT CONFIDENCE IS RATHER
LOW AT THIS POINT. THIS WILL BE A WARMER NIGHT WITH MINIMUM TEMPERATURES
IN THE MID 60S TO LOWER 70S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 345 AM CDT FRI JUL 25 2014
CHANCES FOR SHOWERS AND STORMS THROUGH THE WEEKEND THEN MAINLY DRY AND
COOLER MUCH OF NEXT WEEK.
SAT-SAT NGT...COVERAGE OF STORMS AND SEVERE POTENTIAL ARE THE MAIN
CHALLENGES. MODEL SOUNDINGS GENERALLY SHOW DECENT ELEVATED MIXED
LAYER OR CAP DEVELOPING OVER MUCH OF THE AREA SUPPRESSING CONVECTION
FOR MUCH OF THE DAY. THIS WILL ALSO SPELL VERY WARM AND HUMID
CONDITIONS WITH HIGHS MID 80S TO NEAR 90F AND DEWPTS UPPER 60S TO
LOWER 70S FOR PM HEAT INDICES FROM NEAR 90 NORTH TO AROUND 100 SOUTH.
SEVERAL FCST SOUNDINGS THOUGH SHOW THE CAP WEAKENING AFTER 20-21Z
WITH PASSAGE OF SFC-850 MB COOL FRONTS AND THEREFORE WOULD ANTICIPATE
INCREASING STORM COVERAGE BY LATE AFTN/EVE MAINLY SOUTH OF I-80
VICINITY OF FRONT AND ELEVATED CONVERGENCE AND MOISTURE ADVECTION ON
NOSE OF INCREASING SWLY LOW LEVEL JET. A FEW SEVERE STORMS POSSIBLE
GIVEN MODERATE TO STRONG INSTABILITY (SBCAPE 2500-3500 J/KG) AND
SHEAR (0-6KM 35-50 KTS). MAIN THREAT BEING DAMAGING WINDS WITH LARGE
HAIL RISK SECONDARY AND CONFINED TO SUPERCELLS OR DECENT MESOCYCLONES
GIVEN ABUNDANCE OF MOISTURE IN ATMOSPHERIC COLUMN CHARACTERIZED BY
PWATS OF 1.6-1.9 INCHES AND WARM CLOUD DEPTHS UP AROUND 13KFT AGL...
WHICH POSES RISK OF LOCALLY HEAVY RAIN OF 2+ INCHES WITH POTENTIAL
FOR BACKBUILDING AND ISOLATED HIGHER AMOUNTS WITH VEERED SWLY LOW LEVEL
JET.
SUN-SUN NGT...DIGGING PV ANOMALY FROM UPPER MIDWEST INTO GREAT LAKES
TO USHER IN SECONDARY AND STRONGER COOL FRONT SUNDAY PM. WILL SEE
CHANCES FOR ADDITIONAL SHOWERS AND STORMS MAINLY DURING THE PM INTO
EARLY EVE WITH THIS FRONT WITH BEST CHANCES OVER NORTHEAST 1/3-1/2 OF THE
CWA. NAM AND GFS SHOWING 40-50 KTS OF 0-6KM BULK SHEAR AND WITH
INVERTED V SOUNDINGS AND DRIER AIR ALOFT WILL NEED TO WATCH FOR POTENTIAL
OF MORE ORGANIZED AND STRONGER STORMS CONTAINING GUSTY WINDS AND HAIL.
SUNDAY LOOKS TO BE THE LAST WARM DAY FOR A WHILE... WHICH OF LATE MEANS
LAST DAY AROUND NORMAL.
MON-THU...MEDIUM RANGE MODELS AND ENSEMBLES IN GOOD AGREEMENT WITH THE
OVERALL PATTERN DEPICTING A DEEP UPPER TROUGH OVER THE EASTERN HALF OF THE
CONUS. THIS WILL RESULT IN ANOTHER PERIOD OF GENERALLY BELOW NORMAL
TEMPS...WHICH MAY FEATURE A MORNING OR TWO OF NEAR RECORD LOWS TUE-WED.
CHALLENGE ASIDE FROM TEMPS WILL BE WHETHER ANY PM SHOWER CHANCES EXIST
WITH THE COOLER AIR ALOFT AND ANY IMPULSES IN NORTHWEST FLOW... BUT TOO
FAR OUT AND PROBS APPEAR TOO LOW FOR MUCH MENTION OF PCPN UNTIL POSSIBLY
LATE WEEK AHEAD OF POTENTIALLY ANOTHER SHOT OF COOLER AIR BEYOND THE
SCOPE OF THE CURRENT EXTENDED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1239 PM CDT FRI JUL 25 2014
CONDITIONS WILL IMPROVE TO VFR THROUGH 00Z/26 AS THE NOCTURNAL
TSRA COMPLEX MOVES INTO SOUTHERN ILLINOIS. THE POTENTIAL DOES
EXIST FOR SOME ISOLATED SHRA/TSRA THROUGH SUNSET THAT MAY PRODUCE
BRIEF MVFR CONDITIONS IF THEY AFFECT A TAF SITE. AFT 06Z/26 VFR
CONDITIONS ARE GENERALLY EXPECTED BUT SPOTTY MVFR CONDITIONS MAY
DEVELOP THROUGH SUNRISE DUE TO WET GROUND.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...05
AVIATION...08
AREA FORECAST DISCUSSION
NWS GOODLAND KS
222 PM MDT FRI JUL 25 2014
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 112 PM MDT FRI JUL 25 2014
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW BROAD
RIDGE STILL IN PLACE FROM THE DESERT SW ACROSS THE SOUTHERN
PLAINS...WITH A PLUME OF MID-UPPER LEVEL MOISTURE AND WEAK VORTICITY
ROTATING AROUND THE NORTHERN PERIPHERY OF THIS RIDGE ACROSS THE
CENTRAL ROCKIES INTO THE HIGH PLAINS. A CLOSED LOW IS MOVING ACROSS
SOUTHERN CANADA WITH SOME WEAK REFLECTION OF THIS EXTENDING FURTHER
SOUTH INTO THE NORTHERN PLAINS. AT THE SURFACE A WEAK COLD FRONT HAS
STALLED OVER THE SOUTHERN PART OF OUR CWA...WITH FAVORABLE JULY
SOLAR ANGLE SUPPORTING GOOD RADIATIONAL WARMING THIS AFTERNOON AS
HIGHS HAVE STILL REACHED THE MID TO UPPER 90S OVER MUCH OF THE CWA
(A LITTLE COOLER TOWARDS THE NW).
STALLED FRONT IN THE SOUTH COMBINED WITH ELEVATED TERRAIN IN
COLORADO SHOULD HELP INITIATE THUNDERSTORMS (WHICH HAVE ALREADY
DEVELOPED ALONG FRONT RANGE). HIGH LCL/LFC OVER OUR CWA SHOULD KEEP
THUNDERSTORM ACTIVITY ELEVATED AND WITH INCREASING INSTABILITY AND
DCAPE WOULD SUPPORT POTENTIAL FOR DOWNBURSTS. IF UPDRAFTS ARE STRONG
ENOUGH...MAYBE LARGE HAIL WOULD BE POSSIBLE THIS
AFTERNOON/EVENING...HOWEVER WITH VERY WARM LOW-MID LEVELS ABOVE
SHALLOW FRONTAL INVERSION CONDITIONS ARE MORE IN LINE WITH A WIND
THREAT. GUIDANCE CONTINUES TO SHOW BETTER COVERAGE OVER
CWA...HOWEVER DESPITE GOOD SURFACE-BL MOISTURE ALONG FRONTAL ZONE
AIR MASS ITSELF IS FAIRLY DRY AND COVERAGE IS A QUESTION. BEST
FORCING WOULD ACTUALLY BE LATER IN THE EVENING AS SHORTWAVE (ALONG
WITH POSSIBLE OUTFLOW FROM POSSIBLE MCS IN THE NORTH) MOVES INTO THE
CWA. AT THIS POINT I WAS COMFORTABLE KEEPING COVERAGE ISOLATED AND
DELAYED EXIT UNTIL AFTER 06Z. WILL NEED TO MONITOR TRENDS AS WESTERN
LOCATIONS COULD SEE SLIGHTLY BETTER COVERAGE BEFORE SUNSET.
DEEPENING ON EVOLUTION OF OUTFLOW (AS INDICATED BY NAM) OR WEAK
FRONTAL PASSAGE SATURDAY TEMPS COULD BE TRICKY ONCE AGAIN AS HEIGHTS
AND PATTERN ALOFT WOULD GENERALLY SUPPORT GOOD DAYTIME HEATING AND A
RECOVERY OF THE AIR MASS IN PLACE. I KEPT TEMPS SIMILAR TO TODAY
WITH ABOVE NORMAL VALUES IN THE 90S (AROUND 100F IN THE EAST). HIGH
BASED THUNDERSTORMS MAY DEVELOP AGAIN SATURDAY AFTERNOON ALONG
FRONTAL ZONE IN THE SOUTH...HOWEVER CONFIDENCE IS LOW ON EARLIER
INITIATION OVER OUR CWA...WITH FLOW MORE SUPPORTIVE OF UPSTREAM
DEVELOPMENT IN COLORADO.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 220 PM MDT FRI JUL 25 2014
UPPER FLOW TRANSITIONS FROM ZONAL TO NORTHWESTERLY IN THE SUN-MON
TIME FRAME...WHICH THEN CONTINUES THROUGH THE REST OF THE WEEK.
AT THE SURFACE...A REINFORCING SHOT OF COOLER AIR DROPS DOWN SATURDAY
NIGHT WHICH PUSHES THE SURFACE FRONT WELL SOUTH OF THE FORECAST
AREA. AS A RESULT...MUCH OF THE PRECIPITATION POTENTIAL EARLY ON
WILL BE SOUTH AND WEST OF THE CWA. THE BEST WINDOW FOR THUNDERSTORMS
IN THE EXTENDED PERIOD WILL BE TUE NIGHT-WED NIGHT WHEN THE EC/GFS
BOTH GENERATE AN EXTENSIVE AREA OF PRECIPITATION WHICH MOVES
SOUTHEAST ACROSS THE REGION AS A SHORT WAVE TROUGH DROPS THROUGH
THE FLOW.
THE PRESENCE OF A CANADIAN AIRMASS WHICH DOMINATES THE ENTIRE WEEK
WILL PROVIDE RELIEF FROM THE RECENT STRETCH OF HOT WEATHER. 850 MB
TEMPERATURES ARE FORECAST TO REMAIN IN THE 22-25C RANGE THROUGH
NEXT WEEKEND...WHICH TRANSLATES TO LOW-MID 80S FOR HIGHS. THE
COOLEST DAY WILL BE WEDNESDAY GIVEN THE LIKELY PRESENCE OF CLOUDS
AND SCATTERED SHOWERS AND THUNDERSTORMS. DEPENDING ON CLOUD COVER
THERE IS POTENTIAL FOR SOME AREAS TO REMAIN IN THE UPPER 70S WED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1106 AM MDT FRI JUL 25 2014
VFR CONDITIONS WILL PREVAIL AT BOTH KGLD AND KMCK THROUGH THE TAF
PERIOD. NW WINDS AROUND 10-15KT GUSTING TO AROUND 20KT WILL
CONTINUE THROUGH THE EARLY PART OF THE TAF PERIOD BEHIND A COLD
FRONT JUST SOUTH OF BOTH TERMINALS. BETTER CHANCE FOR GUSTS WILL
BE AT KGLD. BY MID AFTERNOON THE SURFACE GRADIENT WILL RELAX AND
AS A RESULT WIND SPEED WILL DROP TO 10KT OR LESS SHIFTING TO THE
NORTHEAST THEN SOUTHEAST. THERE WILL BE ANOTHER INCREASE IN WINDS
FROM THE NW MID-MORNING SATURDAY FROM THE WEST...HOWEVER GUSTY
WINDS SHOULD HOLD OFF DURING THIS TAF PERIOD SATURDAY.
ISOLATED THUNDERSTORMS WILL DEVELOP LATE THIS AFTERNOON THROUGH
THE EVENING HOURS MAINLY OVER EASTERN COLORADO AND NW KANSAS.
COVERAGE IS A BIG QUESTION AT THIS POINT...SO I AM LEAVING MENTION
OUT OF BOTH KGLD AND KMCK. WE MAY END UP NEEDING TO ADD VCTS AT
KGLD IF COVERAGE IS A LITTLE BETTER THAN CURRENTLY ANTICIPATED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...DLF
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
113 PM MDT FRI JUL 25 2014
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 112 PM MDT FRI JUL 25 2014
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW BROAD
RIDGE STILL IN PLACE FROM THE DESERT SW ACROSS THE SOUTHERN
PLAINS...WITH A PLUME OF MID-UPPER LEVEL MOISTURE AND WEAK VORTICITY
ROTATING AROUND THE NORTHERN PERIPHERY OF THIS RIDGE ACROSS THE
CENTRAL ROCKIES INTO THE HIGH PLAINS. A CLOSED LOW IS MOVING ACROSS
SOUTHERN CANADA WITH SOME WEAK REFLECTION OF THIS EXTENDING FURTHER
SOUTH INTO THE NORTHERN PLAINS. AT THE SURFACE A WEAK COLD FRONT HAS
STALLED OVER THE SOUTHERN PART OF OUR CWA...WITH FAVORABLE JULY
SOLAR ANGLE SUPPORTING GOOD RADIATIONAL WARMING THIS AFTERNOON AS
HIGHS HAVE STILL REACHED THE MID TO UPPER 90S OVER MUCH OF THE CWA
(A LITTLE COOLER TOWARDS THE NW).
STALLED FRONT IN THE SOUTH COMBINED WITH ELEVATED TERRAIN IN
COLORADO SHOULD HELP INITIATE THUNDERSTORMS (WHICH HAVE ALREADY
DEVELOPED ALONG FRONT RANGE). HIGH LCL/LFC OVER OUR CWA SHOULD KEEP
THUNDERSTORM ACTIVITY ELEVATED AND WITH INCREASING INSTABILITY AND
DCAPE WOULD SUPPORT POTENTIAL FOR DOWNBURSTS. IF UPDRAFTS ARE STRONG
ENOUGH...MAYBE LARGE HAIL WOULD BE POSSIBLE THIS
AFTERNOON/EVENING...HOWEVER WITH VERY WARM LOW-MID LEVELS ABOVE
SHALLOW FRONTAL INVERSION CONDITIONS ARE MORE IN LINE WITH A WIND
THREAT. GUIDANCE CONTINUES TO SHOW BETTER COVERAGE OVER
CWA...HOWEVER DESPITE GOOD SURFACE-BL MOISTURE ALONG FRONTAL ZONE
AIR MASS ITSELF IS FAIRLY DRY AND COVERAGE IS A QUESTION. BEST
FORCING WOULD ACTUALLY BE LATER IN THE EVENING AS SHORTWAVE (ALONG
WITH POSSIBLE OUTFLOW FROM POSSIBLE MCS IN THE NORTH) MOVES INTO THE
CWA. AT THIS POINT I WAS COMFORTABLE KEEPING COVERAGE ISOLATED AND
DELAYED EXIT UNTIL AFTER 06Z. WILL NEED TO MONITOR TRENDS AS WESTERN
LOCATIONS COULD SEE SLIGHTLY BETTER COVERAGE BEFORE SUNSET.
DEEPENING ON EVOLUTION OF OUTFLOW (AS INDICATED BY NAM) OR WEAK
FRONTAL PASSAGE SATURDAY TEMPS COULD BE TRICKY ONCE AGAIN AS HEIGHTS
AND PATTERN ALOFT WOULD GENERALLY SUPPORT GOOD DAYTIME HEATING AND A
RECOVERY OF THE AIR MASS IN PLACE. I KEPT TEMPS SIMILAR TO TODAY
WITH ABOVE NORMAL VALUES IN THE 90S (AROUND 100F IN THE EAST). HIGH
BASED THUNDERSTORMS MAY DEVELOP AGAIN SATURDAY AFTERNOON ALONG
FRONTAL ZONE IN THE SOUTH...HOWEVER CONFIDENCE IS LOW ON EARLIER
INITIATION OVER OUR CWA...WITH FLOW MORE SUPPORTIVE OF UPSTREAM
DEVELOPMENT IN COLORADO.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 206 AM MDT FRI JUL 25 2014
FOR THE EXTENDED PERIOD...NO MAJOR CHANGES IN LATEST MODEL RUNS FOR
OVERALL UPPER LEVEL PATTERN. GOING INTO NEXT MONDAY...BROAD H5/H7
RIDGE OVER THE WESTERN PORTION OF THE COUNTRY...AND A DEEP MID LEVEL
TROUGH OVER THE EASTERN PORTION OF THE COUNTRY. THIS LEAVES THE
FORECAST AREA IN BETWEEN THE TWO SYSTEMS FOR THE ENTIRE 4-DAY
PERIOD. AT THE SURFACE...BOUNDARY STAYS ALONG THE EAST COAST...DOWN
INTO THE GULF REGION AND UP INTO THE CENTRAL PLAINS. MONDAY AND
TUESDAY HAS CWA SEEING LOW PRESSURE FORM ALONG THE TAIL-END OF THE
FRONT IN EASTERN COLORADO. WITH LITTLE FORCING TO MOVE CONVECTION
THAT DEVELOPS...KEEPING HEAVIEST CONCENTRATION OF PRECIPITATION OVER
WESTERN PORTIONS OF THE FORECAST AREA.
BY MIDWEEK...WEAK 700 MB SHORTWAVE MOVES OFF THE FRONT RANGE AND
ALONG THE FRONTAL BOUNDARY SLIDING TO OUR SOUTH THROUGH THE DAY INTO
THE EVENING HOURS. MODEL TRACK WILL PUT HIGHEST POP CHANCES ALONG
WESTERN/SOUTHERN ZONES BEFORE TAPERING OFF. BRIEF RESPITE IN
CONVECTIVE ACTIVITY OVERNIGHT WEDNESDAY AS SURFACE RIDGING OCCURS
INTO THURSDAY MORNING. GOING INTO THURSDAY...TROUGH TO THE EAST DOES
RETROGRADE SOME...HINTING THAT CUTOFF LOW MAY FORM. SEVERAL
SHORTWAVES WILL THEN PINWHEEL SOUTH ON BACKSIDE OF THIS SYSTEM...
ALLOWING FOR 20-30 POP POTENTIAL FOR RW/TRW THURSDAY...DROPPING OFF
THURSDAY NIGHT AND THEN RETURNING FOR FRIDAY. WITH REGION SEEING
BROAD NW THROUGH THE EXTENDED TIMEFRAME...COMBINED WITH FRONTAL
BOUNDARY LOCATED JUST TO OUR SOUTH AND CLOUD COVER FROM EXPECTED
CONVECTION...LOOKING FOR TEMPERATURES TO RANGE A FEW DEGREES BELOW
NORMAL FOR BOTH HIGHS(LOW TO MID 80S)/LOWS(LOW TO MID 60S).
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1106 AM MDT FRI JUL 25 2014
VFR CONDITIONS WILL PREVAIL AT BOTH KGLD AND KMCK THROUGH THE TAF
PERIOD. NW WINDS AROUND 10-15KT GUSTING TO AROUND 20KT WILL
CONTINUE THROUGH THE EARLY PART OF THE TAF PERIOD BEHIND A COLD
FRONT JUST SOUTH OF BOTH TERMINALS. BETTER CHANCE FOR GUSTS WILL
BE AT KGLD. BY MID AFTERNOON THE SURFACE GRADIENT WILL RELAX AND
AS A RESULT WIND SPEED WILL DROP TO 10KT OR LESS SHIFTING TO THE
NORTHEAST THEN SOUTHEAST. THERE WILL BE ANOTHER INCREASE IN WINDS
FROM THE NW MID-MORNING SATURDAY FROM THE WEST...HOWEVER GUSTY
WINDS SHOULD HOLD OFF DURING THIS TAF PERIOD SATURDAY.
ISOLATED THUNDERSTORMS WILL DEVELOP LATE THIS AFTERNOON THROUGH
THE EVENING HOURS MAINLY OVER EASTERN COLORADO AND NW KANSAS.
COVERAGE IS A BIG QUESTION AT THIS POINT...SO I AM LEAVING MENTION
OUT OF BOTH KGLD AND KMCK. WE MAY END UP NEEDING TO ADD VCTS AT
KGLD IF COVERAGE IS A LITTLE BETTER THAN CURRENTLY ANTICIPATED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JN
AVIATION...DR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
409 PM EDT FRI JUL 25 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 343 PM EDT FRI JUL 25 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALF
OVER THE UPR LKS BTWN DEEP CLOSED LO OVER NRN QUEBEC AND SHRTWV RDG
AXIS EXTENDING NNEWD INTO MN/NW ONTARIO FM CENTER OF HIER HGTS OVER
THE SRN ROCKIES. ALTHOUGH SLOW INFLUX OF MOISTER AIR IN THE GENERAL
SW FLOW BTWN SFC/H85 HI OVER THE MID ATLANTIC STATES AND LOWER MSLP
IN THE NRN PLAINS ASSOCIATED WITH A DEEP CLOSED LO IN SRN
SASKATCHEWAN THAT IS RIDING OVER THE RDG CENTERED IN THE SRN ROCKIES
HAS ALLOWED FOR A GOOD DEAL OF CLDS/A FEW SHOWERS OVER MAINLY THE W
HALF OF THE CWA TDAY...MAIN FOCUS FOR HEAVIER PCPN HAS BEEN WELL TO
THE SW CLOSER TO SHARP H85 WARM FNT STRETCHING FM THE DAKOTAS INTO
THE MID MS RIVER VALLEY. HI STABILITY SHOWN ON THE 12Z INL RAOB AND
ESPECIALLY THE GRB RAOB...WHICH DEPICTS A SHARP INVRN ARND H75...HAS
TENDED TO LIMIT THE INTENSITY AND COVERAGE OF THE SHOWERS THAT HAVE
IMPACTED UPR MI. OVER THE ERN CWA...VERY DRY/STABLE AIRMASS SHOWN ON
THE 12Z APX RAOB HAS ALLOWED FOR MORE SUNSHINE. BUT TO THE W...MORE
SHOWERS ARE PRESENT IN NE MN/WRN LK SUP IN AREA OF HIER H85 THETA E
ADVCTN IN ADVANCE OF A WEAK SHRTWV MOVING E ALONG THE CNDN BORDER
ARND CLOSED LO IN SASKATCHEWAN. BUT EWD PUSH OF DRIER AIR IN THE NRN
PLAINS IS TENDING TO LIMIT THE OVERALL COVERAGE OF THESE SHOWERS AS
WELL.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE PCPN CHCS ASSOCIATED
WITH SHRTWV NOW MOVING ALONG THE CNDN BORDER.
LATE TDAY/TNGT...EXPECT AREA OF SHOWERS NOW IN NE MN AND A FEW
TS...THE POTENTIAL OF WHICH WL BE LIMITED BY PERSISTENT HIER MID LVL
STABILITY DEPICTED BEST ON THE GFS FCST SDNGS...TO SPREAD W-E INTO
UPR MI WITH AREA OF POSITIVE H85 THETA E ADVCTN THAT WL LIFT PWAT UP
TO ARND 1.5 INCHES/AXIS OF SOME H85-5 QVECTOR CNVGC IN ADVANCE OF
SHRTWV NOW TRACKING E ALONG THE CNDN BORDER. BUT ARRIVAL OF DRY AIR
NOW IN THE NRN PLAINS WL TEND TO DIMINISH THE POPS LATER EVEN THOUGH
THERE ARE HINTS A 2ND SHRTWV MIGHT FOLLOW INTO THE UPR LKS. FCST
LARGE SCALE QVECTOR DVGC OVER THE W LATE INDICATES THE DRYING WL
OVERCOME ANY PVA ASSOCIATED WITH THIS TRAILING SHRTWV. GOING FCST
POPS ARE IN PRETTY GOOD SHAPE AND NEED ONLY SMALL ADJUSTMENTS.
DESPITE THE MID LVL DRYING LATE...DVLPG LO CLDS WL LIMIT THE DIURNAL
TEMP FALL.
SAT...ANY LINGERING MRNG SHOWERS OVER MAINLY THE NE CWA WL END WITH
ARRIVAL OF DRIER AIR ALF THAT WL DEPRESS PWAT TO 0.75-1.0 INCH/DNVA
AND DEEP LYR QVECTOR DVGC AHEAD OF SHRTWV RDG TRAILING THE DEPARTING
2ND SHRTWV. WITH MRNG LO CLDS GIVING WAY TO MORE SUNSHINE AND FCST
H85 TEMPS AS HI AS 17-18C OVER THE W BY 00Z SUN...EXPECT MAX TEMPS
TO RISE INTO THE 80S AWAY FM THE MODERATING INFLUENCE OF THE GREAT
LKS. GIVEN THE MID LVL DRYING/POTENTIAL FOR DEEP MIXING AND NEAR
ADIABATIC LLVL LAPSE RATES...PREFER THE HIER END OF GUIDANCE FOR MAX
TEMPS...AT LEAST OVER THE INTERIOR W HALF. SOME OF THE HIER RES
MODELS...MAINLY THE 12Z NAM AND REGIONAL CNDN MODEL...DO INDICATE
THIS DAYTIME HEATING WL TRIGGER SOME SHOWERS/TS OVER THE ERN CWA IN
THE AFTN WITH CONVERGING LK BREEZES OFF LKS SUP/MI UNDER SOMEHWAT
LOWER HGTS. THE MAIN LIMITING FACTOR FOR THE DLPMNT OF THESE LK
BREEZE SHOWERS/TS WL BE THE DRYING ALF THAT IS FCST TO MIX TO THE
SFC WITH THE DAYTIME HEATING. IN FACT...DEEP MIXING ON THE GFS/NAM
FCST SDNGS HINT SFC DEWPTS OVER THE INTERIOR W HALF COULD MIX OUT AS
LO AS 45-50 LATE IN THE DAY...WITH KINX DROPPING TO 15-20. THE NAM
FCST SDNG FOR NEWBERRY AT 18Z SHOWS SBCAPE ARND 2K G/KG FOR SFC T/TD
OF 75/65. PREFER THE MORE CONSERVATIVE GFS FCST FOR SFC T/TD OF
75/60 AND SBCAPE CLOSE TO 700 J/KG. DESPITE THE LIMITATION OF THE
LARGE SCALE DRYING...WL MAINTAIN SOME LO CHC POPS OVER THE ERN CWA
TO ACCOUNT FOR THE LK BREEZE CNVGC.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 407 PM EDT FRI JUL 25 2014
COOL SUMMER PATTERN PERSISTS AS LARGE SCALE TROUGHING IS FORECAST TO
CONTINUE THROUGH DAYS 7-10. TEMPERATURES REMAIN BELOW NORMAL WITH
THE COOLEST DAYS EXPECTED MONDAY AND TUESDAY AS CORE OF UPPER LOW
AND COLD AIR MOVES ACROSS GREAT LAKES. MAX TEMPS BOTH DAYS LIKELY
WILL END UP AT LEAST 10 DEGREES BELOW NORMAL. NORMAL HIGHS THIS TIME
OF YEAR ARE IN THE MID 70S TO LOW 80S. MIN TEMPS WILL BE 5 TO 10
DEGREES BELOW NORMAL. NORMAL MIN TEMPS ARE IN THE LOW TO MID 50S.
OVERALL THIS PATTERN LOOKS DRY THROUGH THE NEXT COUPLE WEEKS PER THE
MEDIUM RANGE MODELS AND LATEST CPC OUTLOOKS.
BEST SHOT OF RAIN IS LATER SATURDAY NIGHT THROUGH SUNDAY AS UPPER
LOW AND STRONGER SHORTWAVE CURRENTLY OVER SOUTHERN SASKATCHEWAN
MOVES ACROSS WITH ASSOCIATED DEEP LAYER Q-VECTOR CONVERGENCE.
PASSAGE OF SHORTWAVE OCCURS AS THE INITIAL STRONG SFC-H85 COLD FRONT
IS CROSSING THE UPPER GREAT LAKES. MAIN ISSUE IS HOW FAST WILL THE
RAIN ARRIVE SATURDAY NIGHT AND ALSO IF THERE IS ANY POTENTIAL FOR
TSRA. SI/S BARELY BUMP BLO ZERO AND THAT IS FOCUSED ALONG THE WI
BORDER. HIGHEST POPS EXPECTED JUST TO NORTH OF UPPER LOW/SHORTWAVE
TRACK...MAINLY 09Z-21Z SUNDAY. TSRA CHANCES ARE THERE...BUT ARE
LIMITED TO A CHANCE AT BEST. UNLESS THE STORMS FORM EARLIER SATURDAY
EVENING WHEN DEEP SHEAR IS 30-40 KTS AND MLCAPE IS OVER 1000 J/KG...
DO NOT EXPECT ANY SEVERE STORMS SATURDAY NIGHT. INTO SUNDAY IT IS
POSSIBLE THAT IF THE SYSTEM SLOWS THERE WOULD BE INCREASED POTENTIAL
FOR SFC BASED TSRA SUNDAY AFTN. ATTM THOUGH LI/S BLO ZERO ARE
FORECAST TO STAY OVER WI AS STABLE COOL RAINY NORTH FLOW SHUNTS THE
GREATER INSTABILITY TO THE SOUTH. LOWERED TEMPS MORE ALONG LK
SUPERIOR ON SUNDAY...WITH UPR 50S TO AROUND 60 DEGREES. POINTS
FARTHER INLAND OVER SOUTHERN U.P. MAY BE ABLE TO REACH 70 DEGREES AT
LEAST BRIEFLY BEFORE CLOUDS THICKEN AND WIDESPREAD SHOWERS BEGIN.
SHOULD NOTE THAT THE STRONGER NORTH WINDS AND HIGHER WAVES WILL
INCREASE SWIM RISK FOR BEACHES OF LK SUPERIOR MQT TO GRAND MARAIS
SUNDAY INTO MONDAY. IF THE AIR TEMPS REMAIN IN THE UPPER 50S OR
HIGHER...WOULD NEED A BEACH HAZARD STATEMENT TO HIGHLIGHT THE RISK
EITHER FOR SUNDAY OR MONDAY OR POSSIBLY BOTH DAYS. ULTIMATELY WILL
DEPEND ON THE EXPECTED WEATHER FOR THE DAY.
BEYOND SUNDAY...UPPER TROUGH IN THE VCNTY COUPLED WITH INDIVIDUAL
SHORTWAVES AND AREAS OF DEEPER MOISTURE DROPPING ACROSS THE AREA
WILL COMBINE WITH DAYTIME HEATING/INSOLATION TO PRODUCE ISOLD-SCTD
SHOWERS...MAINLY DURING AFTN AND EVENING HOURS OF TUESDAY AND
WEDNESDAY. GRADUAL RISING HEIGHTS RESULT IN LESS CYCLONIC LOW-LEVEL
FLOW BY THURSDAY AND THERE IS ALSO LESS DEEP MOISTURE BY THAT POINT.
EXPECT THE CHANCES OF DIURNAL SHOWERS TO DIMINISH BY LATE THIS WEEK
AS TEMPS BEGIN TO WARM UP AGAIN. JUST ENOUGH MLCAPE DURING THE AFTN
FAR INLAND TO PUT KEEP SMALL TSRA CHANCES AS WELL WITH THE SHRA. MEAN
WINDS FM NORTH TO SOUTH RESULT IN GREATEST CHANCES FOR RAIN MOST DAYS
FARTHEST INLAND FROM THE MODERATION/STABILIZING INFLUENCE OF LK
SUPERIOR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 129 PM EDT FRI JUL 25 2014
WITH INFLUX OF MOISTER AIR IN LLVL SW FLOW AND APRCH OF AN UPPER
DISTURBANCE...EXPECT SHRA AND AREA OF MVFR CLDS NEAR IWD TO
OVERSPREAD CMX AND SAW BY THIS EVNG. WITH SOME DRYING ALF LATE TNGT
THAT WL END THE SHOWERS...EXPECT IFR CONDITIONS TO DVLP IN THE
PRESENCE OF DIURNAL COOLING. LIFR CONDITIONS ARE NOT OUT OF THE
QUESTION. THE ARRIVAL OF DRIER AIR AND DAYTIME WL RESULT IN
IMPROVEMENT TO VFR ON SAT. THIS PROCESS WL BE SLOWEST AT CMX WITH AN
UPSLOPE W WIND.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 PM EDT FRI JUL 25 2014
EXPECT WINDS UNDER 15 KTS THRU SAT NIGHT WITH RELATIVELY WEAK PRES
GRADIENT DOMINATING THE UPPER LAKES. STRONGER N WINDS UP TO 20-25
KTS EXPECTED SUN INTO MON AS COOLER AIR INVADES THE AREA UNDER
TIGHTER GRADIENT BETWEEN HI PRES MOVING INTO THE NORTHERN PLAINS AND
LO PRES OVER THE SE GREAT LAKES. WINDS WILL DIMINISH ON TUE AND BACK
TOWARD THE W WITH CLOSER APPROACH OF HI PRES FROM THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...TITUS/JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
344 PM EDT FRI JUL 25 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 343 PM EDT FRI JUL 25 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALF
OVER THE UPR LKS BTWN DEEP CLOSED LO OVER NRN QUEBEC AND SHRTWV RDG
AXIS EXTENDING NNEWD INTO MN/NW ONTARIO FM CENTER OF HIER HGTS OVER
THE SRN ROCKIES. ALTHOUGH SLOW INFLUX OF MOISTER AIR IN THE GENERAL
SW FLOW BTWN SFC/H85 HI OVER THE MID ATLANTIC STATES AND LOWER MSLP
IN THE NRN PLAINS ASSOCIATED WITH A DEEP CLOSED LO IN SRN
SASKATCHEWAN THAT IS RIDING OVER THE RDG CENTERED IN THE SRN ROCKIES
HAS ALLOWED FOR A GOOD DEAL OF CLDS/A FEW SHOWERS OVER MAINLY THE W
HALF OF THE CWA TDAY...MAIN FOCUS FOR HEAVIER PCPN HAS BEEN WELL TO
THE SW CLOSER TO SHARP H85 WARM FNT STRETCHING FM THE DAKOTAS INTO
THE MID MS RIVER VALLEY. HI STABILITY SHOWN ON THE 12Z INL RAOB AND
ESPECIALLY THE GRB RAOB...WHICH DEPICTS A SHARP INVRN ARND H75...HAS
TENDED TO LIMIT THE INTENSITY AND COVERAGE OF THE SHOWERS THAT HAVE
IMPACTED UPR MI. OVER THE ERN CWA...VERY DRY/STABLE AIRMASS SHOWN ON
THE 12Z APX RAOB HAS ALLOWED FOR MORE SUNSHINE. BUT TO THE W...MORE
SHOWERS ARE PRESENT IN NE MN/WRN LK SUP IN AREA OF HIER H85 THETA E
ADVCTN IN ADVANCE OF A WEAK SHRTWV MOVING E ALONG THE CNDN BORDER
ARND CLOSED LO IN SASKATCHEWAN. BUT EWD PUSH OF DRIER AIR IN THE NRN
PLAINS IS TENDING TO LIMIT THE OVERALL COVERAGE OF THESE SHOWERS AS
WELL.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE PCPN CHCS ASSOCIATED
WITH SHRTWV NOW MOVING ALONG THE CNDN BORDER.
LATE TDAY/TNGT...EXPECT AREA OF SHOWERS NOW IN NE MN AND A FEW
TS...THE POTENTIAL OF WHICH WL BE LIMITED BY PERSISTENT HIER MID LVL
STABILITY DEPICTED BEST ON THE GFS FCST SDNGS...TO SPREAD W-E INTO
UPR MI WITH AREA OF POSITIVE H85 THETA E ADVCTN THAT WL LIFT PWAT UP
TO ARND 1.5 INCHES/AXIS OF SOME H85-5 QVECTOR CNVGC IN ADVANCE OF
SHRTWV NOW TRACKING E ALONG THE CNDN BORDER. BUT ARRIVAL OF DRY AIR
NOW IN THE NRN PLAINS WL TEND TO DIMINISH THE POPS LATER EVEN THOUGH
THERE ARE HINTS A 2ND SHRTWV MIGHT FOLLOW INTO THE UPR LKS. FCST
LARGE SCALE QVECTOR DVGC OVER THE W LATE INDICATES THE DRYING WL
OVERCOME ANY PVA ASSOCIATED WITH THIS TRAILING SHRTWV. GOING FCST
POPS ARE IN PRETTY GOOD SHAPE AND NEED ONLY SMALL ADJUSTMENTS.
DESPITE THE MID LVL DRYING LATE...DVLPG LO CLDS WL LIMIT THE DIURNAL
TEMP FALL.
SAT...ANY LINGERING MRNG SHOWERS OVER MAINLY THE NE CWA WL END WITH
ARRIVAL OF DRIER AIR ALF THAT WL DEPRESS PWAT TO 0.75-1.0 INCH/DNVA
AND DEEP LYR QVECTOR DVGC AHEAD OF SHRTWV RDG TRAILING THE DEPARTING
2ND SHRTWV. WITH MRNG LO CLDS GIVING WAY TO MORE SUNSHINE AND FCST
H85 TEMPS AS HI AS 17-18C OVER THE W BY 00Z SUN...EXPECT MAX TEMPS
TO RISE INTO THE 80S AWAY FM THE MODERATING INFLUENCE OF THE GREAT
LKS. GIVEN THE MID LVL DRYING/POTENTIAL FOR DEEP MIXING AND NEAR
ADIABATIC LLVL LAPSE RATES...PREFER THE HIER END OF GUIDANCE FOR MAX
TEMPS...AT LEAST OVER THE INTERIOR W HALF. SOME OF THE HIER RES
MODELS...MAINLY THE 12Z NAM AND REGIONAL CNDN MODEL...DO INDICATE
THIS DAYTIME HEATING WL TRIGGER SOME SHOWERS/TS OVER THE ERN CWA IN
THE AFTN WITH CONVERGING LK BREEZES OFF LKS SUP/MI UNDER SOMEHWAT
LOWER HGTS. THE MAIN LIMITING FACTOR FOR THE DLPMNT OF THESE LK
BREEZE SHOWERS/TS WL BE THE DRYING ALF THAT IS FCST TO MIX TO THE
SFC WITH THE DAYTIME HEATING. IN FACT...DEEP MIXING ON THE GFS/NAM
FCST SDNGS HINT SFC DEWPTS OVER THE INTERIOR W HALF COULD MIX OUT AS
LO AS 45-50 LATE IN THE DAY...WITH KINX DROPPING TO 15-20. THE NAM
FCST SDNG FOR NEWBERRY AT 18Z SHOWS SBCAPE ARND 2K G/KG FOR SFC T/TD
OF 75/65. PREFER THE MORE CONSERVATIVE GFS FCST FOR SFC T/TD OF
75/60 AND SBCAPE CLOSE TO 700 J/KG. DESPITE THE LIMITATION OF THE
LARGE SCALE DRYING...WL MAINTAIN SOME LO CHC POPS OVER THE ERN CWA
TO ACCOUNT FOR THE LK BREEZE CNVGC.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 451 AM EDT FRI JUL 25 2014
A SOMEWHAT ACTIVE WEATHER PATTERN WILL BE IN PLACE ACROSS THE REGION
THROUGH THE WEEKEND...WITH A SIGNIFICANT COOLDOWN STARTING SUNDAY
AND EXTENDING INTO NEXT WEEK.
ON SATURDAY...THE FORECAST AREA WILL REMAIN UNDER ZONAL W-NW FLOW
ALOFT WITH THE LEFT EXIT REGION OF THE JET AND ASSOCIATED SHORT
WAVE EXITING TO THE EAST. ANY REMAINING SHOWER ACTIVITY FROM FRI
NIGHT SHOULD EXIT AS WELL AS DRY ADVECTION MOVES ACROSS THE AREA.
THIS WILL ALLOW FOR CLEARING SKIES WITH TEMPERATURES TO WARM INTO
THE MID-UPPER 70S ACROSS THE AREA. ALL THE NUMERICAL GUIDANCE
SUGGEST THAT INSTABILITY WILL INCREASE ACROSS THE EASTERN HALF OF
THE FORECAST AREA DURING THE AFTERNOON IN RESPONSE TO THE DIURNAL
HEATING. ALTHOUGH THE FORECAST CAPE VALUES OF 1000-2000 J/KG IS
LIKELY TOO HIGH DUE TO THE NORMAL HIGH BIAS OF SFC DEW
POINTS...THERE WILL LIKELY STILL BE INSTABILITY OF AT LEAST 1000
J/KG DURING THE LATE MORNING/AFTERNOON SIMPLY DUE TO THE STEEPER
LAPSE RATES ALOFT OF 6.5 C/KM. AS SUCH...HAVE OPTED TO MAINTAIN
CHANCE POPS ACROSS THE EASTERN LAKE BREEZE AREAS DURING THE
AFTERNOON HOURS ESPECIALLY WITH THE NAM AND GFS KEEPING THE LEFT
EXIT REGION OF THE JET AND ASSOCIATED WEAK Q-VECTOR CONVERGENCE IN
THIS AREA DURING THE AFTERNOON. THE BIG LIMITING FACTOR FOR MORE
WIDESPREAD CONVECTION WILL BE THE DRY AIR ALOFT...AND LACK OF
SIGNIFICANT LOW LEVEL FORCING OTHER THAN THE LAKE BREEZE ACTIVITY.
THIS AGREES WELL WITH THE HIGH RES NUMERICAL GUIDANCE THAT SUGGEST A
FEW STORMS ALONG THE LAKE BREEZE DURING THE DAY.
ON SATURDAY NIGHT INTO SUNDAY...THE UPPER LOW CURRENTLY OVER ALBERTA
WILL MOVE TOWARD THE AREA. MEANWHILE...THE UPPER LOW NE OF JAMES BAY
WILL RETROGRADE SLIGHTLY TO THE WEST AND SOUTH. THESE TWO FEATURES
WILL ALLOW FOR THE FRONT TO THE NORTH OF THE AREA TO MOVE ACROSS THE
REGION LATE SAT NIGHT INTO SUNDAY MORNING. AS THIS OCCURS...LOW
PRESSURE ASSOCIATED WITH THE UPPER LOW TO THE WEST WILL MOVE ALONG
THE FRONT ON SAT NIGHT INTO SUNDAY...TRACKING SOUTH OF THE AREA.
SHOWER AND ISOLATED STORMS WILL MOVE INTO THE AREA LATER SAT NIGHT
AHEAD OF THE UPPER LOW...THEN SPREAD ACROSS THE ENTIRE FORECAST AREA
ON SUNDAY. SUNDAY SHOULD END UP BEING A FAIRLY COOL AND DAMP DAY
WITH A BRISK /AT LEAST FOR SUMMER/ NORTH WIND. TEMPERATURES WILL
REMAIN FAIRLY STEADY IN THE 60S ACROSS THE AREA. IN FACT...IT WOULD
NOT BE SURPRISING IF TEMPS WILL FALL DURING THE DAY ESPECIALLY
CLOSER TO LAKE SUPERIOR AS 850MB TEMPS DROP TO 10C BY SUN EVENING.
THE GOOD NEWS IS THAT THE RAIN SHOULD RAPIDLY END LATE SUN AFTERNOON
INTO SUNDAY EVENING AS THE LOW MOVES EAST OF THE AREA. HOWEVER...BY
MONDAY MORNING 850MB TEMPS WILL DROP TO +6C WHICH WILL ALLOW FOR A
COOL NIGHT SUNDAY NIGHT. MONDAY WILL BE TRANQUIL AS WELL WITH STABLE
NORTH WINDS AND BUILDING HIGH PRESSURE ACROSS THE UPPER GREAT LAKES.
FOR THE TUE-THU TIME PERIOD...THE UPPER GREAT LAKES WILL REMAIN
BELOW NORMAL WITH THE DEEP TROUGH PERSISTING ACROSS THE EASTERN HALF
OF THE U.S. THROUGH THE PERIOD. THE UPPER LOW JUST EAST OF HUDSON
BAY WILL REMAIN FAIRLY STATIONARY THROUGH THE PERIOD. WEAK UPPER
LEVEL SHORT WAVES WILL ROTATE AROUND THE UPPER LOW AND ACROSS THE
AREA...WHICH WILL MAKE TIMING OF PRECIPITATION SOMEWHAT DIFFICULT.
HOWEVER...WITH THE COLD TEMPERATURES ALOFT COMBINED WITH FAIRLY
FREQUENT DISTURBANCES ALOFT...EXPECT THE BEST CHANCES FOR SHOWERS
AND STORMS TO BE DURING THE PEAK HEATING HOURS IN THE AFTERNOON AND
EARLY EVENING HOURS EACH DAY. OTHERWISE...TEMPERATURES WILL REMAIN
BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 129 PM EDT FRI JUL 25 2014
WITH INFLUX OF MOISTER AIR IN LLVL SW FLOW AND APRCH OF AN UPPER
DISTURBANCE...EXPECT SHRA AND AREA OF MVFR CLDS NEAR IWD TO
OVERSPREAD CMX AND SAW BY THIS EVNG. WITH SOME DRYING ALF LATE TNGT
THAT WL END THE SHOWERS...EXPECT IFR CONDITIONS TO DVLP IN THE
PRESENCE OF DIURNAL COOLING. LIFR CONDITIONS ARE NOT OUT OF THE
QUESTION. THE ARRIVAL OF DRIER AIR AND DAYTIME WL RESULT IN
IMPROVEMENT TO VFR ON SAT. THIS PROCESS WL BE SLOWEST AT CMX WITH AN
UPSLOPE W WIND.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 AM EDT FRI JUL 25 2014
EXPECT WINDS UNDER 15 KTS THRU SAT NIGHT WITH RELATIVELY WEAK PRES
GRADIENT DOMINATING THE UPPER LAKES. STRONGER N WINDS UP TO 20-25
KTS ARE POSSIBLE ON SUN INTO MON AS COOLER AIR INVADES THE AREA
UNDER TIGHTER GRADIENT BETWEEN HI PRES MOVING INTO THE NORTHERN
PLAINS AND LO PRES OVER THE SE GREAT LAKES. WINDS WILL DIMINISH ON
TUE AND BACK TOWARD THE W WITH CLOSER APPROACH OF HI PRES FROM THE
PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...MRD
AVIATION...KC
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
227 PM EDT FRI JUL 25 2014
.SYNOPSIS...
ISSUED AT 303 AM EDT FRI JUL 25 2014
HIGH PRESSURE WILL GIVE WAY TO A FAST MOVING SYSTEM TONIGHT AND
SATURDAY. CLOUDS WILL BE ON THE INCREASE TODAY...WITH A CHANCE FOR
SHOWERS AND A FEW THUNDERSTORMS TONIGHT INTO THE START OF THE
WEEKEND. A MUCH STRONGER SYSTEM WILL ARRIVE TO END THE WEEKEND...
BRINGING BETTER POTENTIAL FOR SHOWERS SUNDAY AND SUNDAY NIGHT. A
RETURN TO MUCH BELOW NORMAL TEMPERATURES ON MONDAY...WITH ONLY A
SLOW MODERATION EXPECTED THROUGH THE REMAINDER OF THE WEEK.
&&
.UPDATE...
ISSUED AT 201 PM EDT FRI JUL 25 2014
INSERTED SOME ISOLATED POPS IN THE SW COUNTIES AS THE SOME
MOISTURE RIDES DOWN THE FORMING WARM FRONT AND IS GENERATING SOME
SHOWERS. HOWEVER, THEY ARE HAVING A HARD TIME GETTING INTO THE
FORECAST AREA, MUCH WITH THE DRY AIR IT WILL TAKE UNTIL THIS
EVENING BEFORE THAT HAPPENS.
UPDATE ISSUED AT 948 AM EDT FRI JUL 25 2014
RAIN SHOWERS OVER WISCONSIN ARE TRYING TO MAKE THEIR WAY INTO N
LOWER FOR THE AFTERNOON. WILL BE WATCHING THESE AS THEY SEEMED TO
BE HIGH BASED SHOWERS (9000-10000FT BASES) WITH SCT DECKS DOWN
LOWER. KAPX 12Z SOUNDING SHOWED LOTS OF DRY AIR, BUT ACROSS THE
LAKE KGRB 12Z SOUNDING SHOWED SOME MOISTENING BETWEEN 925 MB AND
750 MB. HOWEVER, BOTH SOUNDINGS SHOWED PRONOUNCED CAPPING
INVERSION AROUND 750 MB. SO WE ARE IN A WAIT AND SEE GAME, GUT
FEELING IS THAT WE SEE SOME SPRINKLES IN THE AFTERNOON, BUT NO
MEASURABLE RAIN SHOWERS. MAY HAVE TO BUMP THE POPS UP TO ISOLATED
SHOWERS IN NW LOWER DEPENDING ON THE TRENDS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 303 AM EDT FRI JUL 25 2014
...MORE CLOUDS AND A SHADE WARMER WITH STORM CHANCES TONIGHT...
IMPACTS: LIGHTNING...BUT NO SEVERE WEATHER EXPECTED.
CURRENT WEATHER AND SYNOPTIC PATTERN:
BROAD UPPER RIDGING SEEN OVER THE SW PART OF THE COUNTRY WHILE
TROUGHING IS STILL THE THEME OVER THE EASTERN CONUS. THE RIDGING HAS
BEEN SQUASHED DUE TO A WRAPPED UP CLOSED LOW DRIFTS ACROSS SW
CANADA. THIS HAS INDUCED LOW PRESSURE OVER EASTERN CANADA AND THE
NRN PLAINS. AN AXIS OF DEEP THETA-E AIR...LEADING EDGE OF STEEP
LAPSE RATES ALOFT (6.5C/KM-7.5C/KM) AND LLJ (45-55KT) CONVERGENCE
AHEAD OF THE PLAINS SFC LOW HAS RESULTED IN POCKETS OF SHOWERS AND
STORMS IN THE DAKOTAS DOWN TO NE. CLOSER TO HOME...AREA VAD WIND
PROFILES AND RUC ANALYSIS SHOWING A TROUGH AXIS AND H8 MOISTURE
ADVECTION FROM THE ARROWHEAD OF MN DOWN THROUGH WISCONSIN. THERE
WERE A FEW ELEVATED RETURNS...BUT ONLY A FEW SPRINKLES HITTING
GROUND PER AREA OBS. OVER NRN MICHIGAN...WE ARE STILL UNDER THE
INFLUENCE OF SFC HIGH PRESSURE...BUT THOSE SAME VAD WIND PROFILES
SHOW THAT THIS HAS SHIFTED JUST EAST OF US WITH A RETURN TO A SW
WIND. AIR MASS IS STILL QUITE DRY WITH PWATS RELATIVELY LOWER THAN
ANYWHERE NEARBY. ONLY A BAND OF HIGHER LEVEL CLOUD STREAMING DOWN
THROUGH THE NW FLOW ALOFT. THE DRY AIR AND MOSTLY CLEAR SKIES HAVE
ALLOWED TEMPERATURES TO FALL INTO THE LOWER HALF OF THE 40S IN THE
LOW LYING AREAS...WHILE COASTAL AREAS AND SOME EXPOSED HIGHER
TERRAIN ARE IN THE LOWER HALF OF THE 50S.
SYNOPTIC PATTERN/WEATHER EVOLUTION:
THE SFC HIGH GRADUALLY SINKS OFF TO THE SE TODAY...WHILE THE
SOUTHERLY PRESSURE GRADIENT TIGHTENS AND DRAWS IN MORE LOW LEVEL
MOISTURE THROUGH THE DAY AND NIGHT. THE INITIAL H8 TROUGH AND
MOISTURE ADVECTION WILL DRIFT OVERHEAD TODAY...AND MAYBE SOME
SPRINKLES ARE POSSIBLE EARLY THIS MORNING...BUT DAYTIME MIXING AND
DRYING OF THE LOWER LEVELS WILL MOST LIKELY SEAL OFF ANY CHANCES FOR
SPRINKLES TO HIT GROUND. THE MOISTURE WILL REVEAL ITSELF IN A HIGHER
BASED CUMULUS FIELD...BUT ALSO MAY GET STUCK UNDERNEATH AN INVERSION
IN FCST BFR SOUNDINGS. THIS COULD LEAD TO A PERIOD OF MOSTLY CLOUDY
SKIES...BUT REALLY DOUBT THIS WILL HAVE MUCH AFFECT ON RISING TEMPS
REACHING THE MIDDLE 70S MOST AREAS. THIS INVERSION AND DRY SFC TDS
RESULT IN A PRETTY PRONOUNCED CAPPING FOR THE ENTIRE DAY...WITH
LITTLE TO NO CHANCE FOR AFTERNOON CONVECTION.
THERE ARE DIFFERENCES IN HOW THIS LID EVOLVES OVER THE NIGHT...BUT
WE WILL AT LEAST BE TRENDING TOWARD MORE UNSTABLE CONDITIONS. SOME
SHORTWAVE ENERGY/VORTICITY EJECTS FROM AFOREMENTIONED CLOSED LOW
DRIFTING THROUGH SRN CANADA. THIS FORCING ARRIVES LATE EVENING AND
OVERNIGHT. WEAK LOW PRESSURE AND A WARM FRONT LIFT UP TOWARD/INTO
NRN MICHIGAN. THE SAME FCST BFR SOUNDINGS...IN A SCENARIO LIKE
THIS...WOULD LIKELY ERODE/SUPPRESS THE CAP...UNLIKE THE GFS
SUGGESTION. RATHER...WILL GO WITH SHOWERS AND EMBEDDED
GARDEN-VARIETY THUNDERSTORMS DEVELOPING LATE EVENING/OVERNIGHT.
NOTHING SEVERE ANTICIPATED...AS OUR LAPSE RATES AND OVERALL
INSTABILITY WILL NOT MIRROR CURRENT ENVIRONMENT ACROSS THE NRN
PLAINS. WE WILL ONLY HAVE SEVERAL HUNDRED J/KG MUCAPE WITH LAPSE
RATES ALOFT 6-6.5C/KM. THE GREATEST MUCAPE LIKELY TO BE DOWN AROUND
THE MANISTEE/CADILLAC AREAS...ALSO WHERE SOME ADDITIONAL LIFT
ASSISTANCE WILL BE PROVIDED BY UPPER DIVERGENCE IN SOMEWHAT OF A
DOUBLE JET STRUCTURE. WOULD GO WITH LIKELY CHANCES FOR SEEING
PRECIPITATION...BUT BULK OF INSTABILITY AND LLJ FORCING WILL ONCE
AGAIN BE ACROSS SRN WI/NRN IL/SRN LAKE MICHIGAN. THIS COULD BLOCK US
FROM SEEING SOME OF THE ACTION. REGARDLESS...LIKELY TO BE SOME
PRECIPITATION...BEST DESCRIPTION OF WHICH CAN BE PROVIDED BY LATER
SHIFTS AS THE EVENT UNFOLDS.
LOWS TONIGHT WILL LIKELY BE MILD WITH THICKENING CLOUDS...LOWER HALF
OF THE 60S MOST AREAS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 303 AM EDT FRI JUL 25 2014
...RAINY END TO THE WEEKEND/COOL TEMPERATURES ON THE WAY FOR THE
START OF NEXT WEEK...
HIGH IMPACT WEATHER POTENTIAL: NOT A BUNCH. CHANCES FOR A FEW
NON-SEVERE THUNDERSTORMS HEADING THROUGH THE WEEKEND.
PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: WHILE STILL PLENTY OF THE
FINER DETAILS TO WORK OUT...MUCH TALKED ABOUT TRANSITION TO A MORE
MERIDIONAL NOAM UPPER FLOW PATTERN STILL ON TARGET TO DEVELOP HEADING
INTO AND THROUGH NEXT WEEK. NO LINGERING DOUBT MICHIGAN WILL BE
CENTERED IN UNSEASONABLY CHILL PRODUCING TROUGH AXIS...WHICH WILL BE
A SLOW ONE TO DEPART ONCE IT DEVELOPS. PLAYERS FOR SUCH UNUSUAL
DEVELOPMENTS ALREADY ON THE TABLE...WITH LARGE NORTHERN QUEBEC GYRE
SIMPLY STUCK IN PLACE...ALL THE WHILE STRONG PACIFIC SHORTWAVE MAKES
STEADY EAST PROGRESS ACROSS THE SOUTHERN CANADIAN ROCKIES. THE
LATTER WILL SIMPLY REINFORCE AND EXTEND THE FORMER AS IT
SLING-SHOTS AROUND IT THROUGH EARLY NEXT WEEK. COMBINE THAT WITH
DEVELOPMENT OF FULLY MATURE GULF OF ALASKA TROUGH/WEST NOAM RIDGE
COUPLET (NOT TO MENTION ONE REALLY AMPLIFIED ATLANTIC RIDGE)...AND
ONE CAN SEE WHY A PATTERN MUCH MORE RESEMBLING THE COOL SEASON IS
EXPECTED.
PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS THROUGHOUT
AND EVOLUTION OF PERIODIC RAIN CHANCES. THUNDERSTORM POTENTIAL AND
INTENSITY WILL ALSO NEED ADDRESSING THIS WEEKEND.
DETAILS: SATURDAY CONTINUES TO REMAIN A CHALLENGE...WITH TIGHT
THETA-E GRADIENT AND SURGE OF BEST UPPER JET FORCING EXITING STAGE
RIGHT RATHER QUICKLY DURING THE MORNING. LEFT BEHIND WILL BE A MUCH
MORE MOIST LOW LEVEL AIRMASS...WITH DEWPOINTS EXPECTED TO BE UP IN
THE MID AND PERHAPS UPPER 60S. KINDA EXPECT WHAT EVER PUNCHES
THROUGH HERE TONIGHT WILL LARGELY EXIT DURING THE MORNING
HOURS...LEAVING NEXT LOW AMP WAVE AND DIURNAL DRIVEN DESTABILIZATION
TO DRIVE ADDITIONAL SHOWER AND STORM DEVELOPMENT. MOISTURE CROSS
SECTIONS SHOW GOOD TO EXCELLENT MOISTURE DEPTH UP THROUGH H7...WITH
AGGRESSIVE DRYING ABOVE THIS LAYER. MANIPULATING MODEL DERIVED
SOUNDINGS WITH ANTICIPATED DEWPOINTS/TEMPERATURES DOES YIELD
DEVELOPMENT OF UPWARDS OF 1K-1.5K J/KG OF ML CAPE DURING THE
AFTERNOON. THINK THIS MIGHT BE A TOUCH AGGRESSIVE...EXPECTING LOW
LEVELS TO BE NOT QUITE AS SATURATED AS GUIDANCE WOULD SUGGEST. WHILE
BEST DYNAMICS WILL HAVE EXITED...NOT ALL IS LOST...WITH MID LEVEL
JET ROTATING THROUGH THE SOUTHWEST LAKES...COMBINING WITH LAKE
INDUCED LOW LEVEL CONVERGENCE /PARTICULARLY IN NORTHEAST LOWER AND
INTERIOR EASTERN UPPER MICHIGAN/ AND SAID WEAK WAVE. ABOVE
DEFINITELY SUPPORTS SOME ADDITIONAL CONVECTIVE POTENTIAL...
ESPECIALLY IN CLIMATOLOGICALLY FAVORED AREAS. INHERITED FORECAST
ALREADY WELL TRENDED IN THIS DIRECTION...WITH ONLY SOME MASSAGING
NEEDED TO POP/WEATHER GRID. DECENT DEEP LAYER SHEAR OF 30 TO 40
KNOTS LARGELY OFFSET BY LIMITED MID LEVEL LAPSE RATES AND SKINNY
CAPE PROFILE UP THROUGH HAIL GROWTH ZONE. SO...IF STORMS CAN DEVELOP
(A BIG IF)...WOULD EXPECT THEM TO REMAIN BELOW SEVERE LIMITS.
LOSS OF INSTABILITY AND RAPID APPROACH OF SHORTWAVE RIDGING EXPECTED
TO BRING A MOSTLY DRY SATURDAY NIGHT. RATHER VIGOROUS CURRENT
SOUTHERN CANADA WAVE QUICKLY FOLLOWS FOR SUNDAY...AND WHEN COMBINED
WITH GOOD SLUG OF LEFT EXIT REGION UPPER JET DYNAMICS...LOOKS TO
BRING A RATHER WIDESPREAD SHOWER EVENT SUNDAY INTO SUNDAY NIGHT.
SYSTEM EVEN LOOKS TO TAKE ON COLD SEASON CHARACTERISTICS...WITH MORE
STEADY RAIN POTENTIAL IN FAVORED NORTH SIDE DEFORMATION FIELD. SOME
THUNDER THREAT REMAINS SUNDAY WITH OPPORTUNITY FOR SOME
DESTABILIZATION BEFORE BETTER FORCING ARRIVES.
TROUGHING DIGS IN AND STAYS THERE-ON-AFTER...PERHAPS LASTING THROUGH
ALL OF NEXT WEEK. COLDEST ANOMALIES EXPECTED TO SLIDE JUST OFF TO
OUR NORTHEAST. THAT SAID...COLD AIR ADVECTION ON FRONT SIDE OF
SPRAWLING NORTHERN PLAINS HIGH WILL BE IMPRESSIVE INDEED...ONCE
AGAIN NOT ALLOWING TEMPERATURES TO GET OUT OF THE 60S ON MONDAY. A
VERY SLOW MODERATION TO FOLLOW...WITH HIGHS WARMING A FEW DEGREES
EACH DAY THROUGH THURSDAY (EVEN BY THURSDAY...HIGHS WILL STILL BE A
FEW DEGREES BELOW NORMAL). DESPITE TROUGHING...JUST NOT OVERLY
IMPRESSED WITH RAIN CHANCES AFTER SUNDAY NIGHTS WAVE PASSAGE. DEEP
LAYER FLOW WILL REMAIN NORTH TO NORTHWEST...AND MID LEVEL
TEMPERATURE REALLY NEVER GET TOO COLD...REACHING THE NEGATIVE UPPER
TEENS AT H5 LATER MONDAY INTO TUESDAY. OF COURSE...ANY WAVES
ROTATING THROUGH WILL ONLY HELP THE SHOWER CAUSE...BUT TIMING AND
MAGNITUDE OF SUCH NOT POSSIBLE TO DETERMINE JUST YET. NO REASON TO
CHANGE THAT WHICH WAS INHERITED...FEATURING JUST ISOLATED/LOW CHANCE
SHOWER POTENTIAL DURING THE DAYTIME HOURS. THIS WILL CHANGE...OF
COURSE...BUT PLENTY OF TIME TO FIGURE THOSE DETAILS OUT IN THE
COMING DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 201 PM EDT FRI JUL 25 2014
FOR THE NEXT 18 HOURS (THROUGH 12Z), IT LOOKS LIKE THE DRY AIR
UNDER THE SFC HIGH SHOULD KEEP VFR CONDITIONS OVER N LOWER MI.
HOWEVER, AROUND 12Z SATURDAY, THE WARM FRONT, ASSOCIATED WITH THE
SFC LOW THAT WILL BE NEAR LAKE WINNIPEG, WILL MOVE THROUGH THE
FORECAST AREA, BRINGING MAINLY RAIN SHOWERS AND MVFR CIGS, WITH
SOME POSSIBLE MVFR VSBYS DURING THE MORNING.
&&
.MARINE...
ISSUED AT 303 AM EDT FRI JUL 25 2014
SW WINDS WILL INCREASE HEADING THROUGH TONIGHT...AHEAD OF SFC LOW
PRESSURE AND A WARM FRONT...WHICH WILL BRING AREAS OF SHOWERS AND
GARDEN-VARIETY STORMS TO THE GREAT LAKES. NOTHING SEVERE....AND
WINDS TO REMAIN ABOVE ADVISORY LEVELS. EXPECTING NO MORE THAN
20KTS..WHICH WILL LARGELY RESIDE ACROSS LAKE MICHIGAN. WINDS REMAIN
UNDER ADVISORY LEVELS SATURDAY AND SUNDAY IN WEAK GRADIENT. ANOTHER
SFC LOW CROSSES SUNDAY MORNING WITH A BETTER CHANCE FOR SHOWERS AND
STORMS...AND MUCH COOLER AIR SET TO ARRIVE THROUGH THE DAY SUNDAY
AND SUNDAY NIGHT.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JL
SYNOPSIS...MSB
SHORT TERM...SMD
LONG TERM...MSB
AVIATION...JL
MARINE...SMD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
131 PM EDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 912 AM EDT FRI JUL 25 2014
ALTHOUGH INFLUX OF MSTR IN SW FLOW BTWN HI PRES IN THE MID ATLANTIC
STATES AND FALLING MSLP IN THE PLAINS ASSOCIATED WITH CLOSED H5 LO
MOVING INTO SASKATCHEWAN WL ALLOW SCT SHOWERS OVER WRN UPR MI THIS
MRNG TO SPREAD TO THE E THRU THE DAY...LOWERED THE CHC FOR TS GIVEN
HI STABILITY SHOWN ON THE 12Z INL AND ESPECIALLY THE GRB RAOBS AS
WELL AS RUC FCST SDNGS FOR EVEN IRONWOOD THRU 21Z.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 427 AM EDT FRI JUL 25 2014
THERE IS CURRENTLY A SFC RIDGE OVER THE CWA EXTENDING HIGH PRESSURE
OVER THE OHIO VALLEY. THIS RIDGE WILL BE FIGHTING OFF AN APPROACHING
LOW PRESSURE SYSTEM THAT IS CURRENTLY OVER THE SRN PORTION OT THE
ALBERTA/SASKATCHEWAN BORDER. BETWEEN THESE TWO FEATURES IS A 500MB
RIDGE...THE AXIS OF WHICH IS OVER THE ERN DAKOTAS AND INTO MANITOBA.
A SHORTWAVE IS CURRENTLY OVER FAR WRN LAKE SUPERIOR AND WILL MOVE
ALONG THE MI/WI BORDER THIS MORNING. SOME SHOWERS HAVE DEVELOPED
ALONG AND AHEAD OF THE SHORTWAVE...BUT WITH DRY LOW LEVELS HAVE ONLY
SEEN ONE OR TWO SFC OBS WITH VERY LIGHT RAIN...ALTHOUGH VIS REMAINED
10SM AND CIGS WERE AROUND 10KFT WITH THE SHOWERS.
THE SFC RIDGE WILL WEAKEN SOME THROUGH THE DAY WHILE BECOMING MORE
CONFINED TO THE FAR ERN/NRN CWA. MOISTURE WILL INCREASE OVER THE WRN
CWA THROUGH THE DAY SLOWLY...ALLOWING FOR INCREASED CHANCES OF
PRECIP THROUGH THE DAY ADDITIONAL WEAK SHORTWAVE ENERGY MOVES
THROUGH WHILE WAA INCREASES. STILL DO NOT HAVE MORE THAN LOW END
CHANCE POPS. WITH THE LINGERING DRY AIR OVER THE E...KEEP THEM DRY
THROUGH MOST OF THE DAY.
THE CONTINUALLY WEAKENING RIDGE PUSHES COMPLETELY E OF THE CWA FRI
NIGHT AS SHORTWAVE ENERGY AND A SFC TROUGH MOVES INTO THE CENTRAL
CWA BY LATE IN THE NIGHT. MAINTAINED CHANCE POPS INTO FRI NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 451 AM EDT FRI JUL 25 2014
A SOMEWHAT ACTIVE WEATHER PATTERN WILL BE IN PLACE ACROSS THE REGION
THROUGH THE WEEKEND...WITH A SIGNIFICANT COOLDOWN STARTING SUNDAY
AND EXTENDING INTO NEXT WEEK.
ON SATURDAY...THE FORECAST AREA WILL REMAIN UNDER ZONAL W-NW FLOW
ALOFT WITH THE LEFT EXIT REGION OF THE JET AND ASSOCIATED SHORT
WAVE EXITING TO THE EAST. ANY REMAINING SHOWER ACTIVITY FROM FRI
NIGHT SHOULD EXIT AS WELL AS DRY ADVECTION MOVES ACROSS THE AREA.
THIS WILL ALLOW FOR CLEARING SKIES WITH TEMPERATURES TO WARM INTO
THE MID-UPPER 70S ACROSS THE AREA. ALL THE NUMERICAL GUIDANCE
SUGGEST THAT INSTABILITY WILL INCREASE ACROSS THE EASTERN HALF OF
THE FORECAST AREA DURING THE AFTERNOON IN RESPONSE TO THE DIURNAL
HEATING. ALTHOUGH THE FORECAST CAPE VALUES OF 1000-2000 J/KG IS
LIKELY TOO HIGH DUE TO THE NORMAL HIGH BIAS OF SFC DEW
POINTS...THERE WILL LIKELY STILL BE INSTABILITY OF AT LEAST 1000
J/KG DURING THE LATE MORNING/AFTERNOON SIMPLY DUE TO THE STEEPER
LAPSE RATES ALOFT OF 6.5 C/KM. AS SUCH...HAVE OPTED TO MAINTAIN
CHANCE POPS ACROSS THE EASTERN LAKE BREEZE AREAS DURING THE
AFTERNOON HOURS ESPECIALLY WITH THE NAM AND GFS KEEPING THE LEFT
EXIT REGION OF THE JET AND ASSOCIATED WEAK Q-VECTOR CONVERGENCE IN
THIS AREA DURING THE AFTERNOON. THE BIG LIMITING FACTOR FOR MORE
WIDESPREAD CONVECTION WILL BE THE DRY AIR ALOFT...AND LACK OF
SIGNIFICANT LOW LEVEL FORCING OTHER THAN THE LAKE BREEZE ACTIVITY.
THIS AGREES WELL WITH THE HIGH RES NUMERICAL GUIDANCE THAT SUGGEST A
FEW STORMS ALONG THE LAKE BREEZE DURING THE DAY.
ON SATURDAY NIGHT INTO SUNDAY...THE UPPER LOW CURRENTLY OVER ALBERTA
WILL MOVE TOWARD THE AREA. MEANWHILE...THE UPPER LOW NE OF JAMES BAY
WILL RETROGRADE SLIGHTLY TO THE WEST AND SOUTH. THESE TWO FEATURES
WILL ALLOW FOR THE FRONT TO THE NORTH OF THE AREA TO MOVE ACROSS THE
REGION LATE SAT NIGHT INTO SUNDAY MORNING. AS THIS OCCURS...LOW
PRESSURE ASSOCIATED WITH THE UPPER LOW TO THE WEST WILL MOVE ALONG
THE FRONT ON SAT NIGHT INTO SUNDAY...TRACKING SOUTH OF THE AREA.
SHOWER AND ISOLATED STORMS WILL MOVE INTO THE AREA LATER SAT NIGHT
AHEAD OF THE UPPER LOW...THEN SPREAD ACROSS THE ENTIRE FORECAST AREA
ON SUNDAY. SUNDAY SHOULD END UP BEING A FAIRLY COOL AND DAMP DAY
WITH A BRISK /AT LEAST FOR SUMMER/ NORTH WIND. TEMPERATURES WILL
REMAIN FAIRLY STEADY IN THE 60S ACROSS THE AREA. IN FACT...IT WOULD
NOT BE SURPRISING IF TEMPS WILL FALL DURING THE DAY ESPECIALLY
CLOSER TO LAKE SUPERIOR AS 850MB TEMPS DROP TO 10C BY SUN EVENING.
THE GOOD NEWS IS THAT THE RAIN SHOULD RAPIDLY END LATE SUN AFTERNOON
INTO SUNDAY EVENING AS THE LOW MOVES EAST OF THE AREA. HOWEVER...BY
MONDAY MORNING 850MB TEMPS WILL DROP TO +6C WHICH WILL ALLOW FOR A
COOL NIGHT SUNDAY NIGHT. MONDAY WILL BE TRANQUIL AS WELL WITH STABLE
NORTH WINDS AND BUILDING HIGH PRESSURE ACROSS THE UPPER GREAT LAKES.
FOR THE TUE-THU TIME PERIOD...THE UPPER GREAT LAKES WILL REMAIN
BELOW NORMAL WITH THE DEEP TROUGH PERSISTING ACROSS THE EASTERN HALF
OF THE U.S. THROUGH THE PERIOD. THE UPPER LOW JUST EAST OF HUDSON
BAY WILL REMAIN FAIRLY STATIONARY THROUGH THE PERIOD. WEAK UPPER
LEVEL SHORT WAVES WILL ROTATE AROUND THE UPPER LOW AND ACROSS THE
AREA...WHICH WILL MAKE TIMING OF PRECIPITATION SOMEWHAT DIFFICULT.
HOWEVER...WITH THE COLD TEMPERATURES ALOFT COMBINED WITH FAIRLY
FREQUENT DISTURBANCES ALOFT...EXPECT THE BEST CHANCES FOR SHOWERS
AND STORMS TO BE DURING THE PEAK HEATING HOURS IN THE AFTERNOON AND
EARLY EVENING HOURS EACH DAY. OTHERWISE...TEMPERATURES WILL REMAIN
BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 129 PM EDT FRI JUL 25 2014
WITH INFLUX OF MOISTER AIR IN LLVL SW FLOW AND APRCH OF AN UPPER
DISTURBANCE...EXPECT SHRA AND AREA OF MVFR CLDS NEAR IWD TO
OVERSPREAD CMX AND SAW BY THIS EVNG. WITH SOME DRYING ALF LATE TNGT
THAT WL END THE SHOWERS...EXPECT IFR CONDITIONS TO DVLP IN THE
PRESENCE OF DIURNAL COOLING. LIFR CONDITIONS ARE NOT OUT OF THE
QUESTION. THE ARRIVAL OF DRIER AIR AND DAYTIME WL RESULT IN
IMPROVEMENT TO VFR ON SAT. THIS PROCESS WL BE SLOWEST AT CMX WITH AN
UPSLOPE W WIND.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 AM EDT FRI JUL 25 2014
EXPECT WINDS UNDER 15 KTS THRU SAT NIGHT WITH RELATIVELY WEAK PRES
GRADIENT DOMINATING THE UPPER LAKES. STRONGER N WINDS UP TO 20-25
KTS ARE POSSIBLE ON SUN INTO MON AS COOLER AIR INVADES THE AREA
UNDER TIGHTER GRADIENT BETWEEN HI PRES MOVING INTO THE NORTHERN
PLAINS AND LO PRES OVER THE SE GREAT LAKES. WINDS WILL DIMINISH ON
TUE AND BACK TOWARD THE W WITH CLOSER APPROACH OF HI PRES FROM THE
PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...TITUS
LONG TERM...MRD
AVIATION...KC
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1214 PM CDT FRI JUL 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT FRI JUL 25 2014
EARLY MORNING THUNDERSTORMS CONTINUED TO DEVELOP ACROSS THE REGION
THIS MORNING FUELED BY THE VEERING WINDS ASSOCIATED WITH THE THETA_E
ADVECTION IN CONNECTION WITH THE LOW LEVEL JET. OVER THE NEXT FEW
HOURS THIS 40KT JET WILL BECOME MORE FOCUSED ACROSS SOUTHERN...AND
EVENTUALLY SOUTHEASTERN MN. AS A RESULT PRECIPITATION WILL CONTINUE
TO DEVELOP FOR THE NEXT FEW HOURS...BUT SHOULD GRADUALLY WANE
SHORTLY AFTER SUNSET AS IT ENTERS WESTERN WI.
EARLIER RUNS OF THE RAP MISSED THE PRECIP THAT DEVELOPED IN
NORTHEAST SD...SO IT IS NO SURPRISE THAT HIGHRES MODELS HAVE BEEN
STRUGGLING TO GET A HANDLE ON THE TWO AREAS OF PRECIP THAT DEVELOPED
EARLIER. AS A RESULT MOST OF THE RUNS HAVE BEEN ALL BUT DISCARDED.
THE 25.06HRRR HAS FINALLY CAUGHT UP AND IT SUPPORTS THE IDEA OF
CONTINUED CONVECTION THIS MORNING...BUT WITH A WEAKENING TREND AFTER
11Z. THE SEVERE WEATHER THREAT IS VERY LOW GIVEN THE DEEP STABLE
LAYER BENEATH THE ELEVATED CAPE...AND ONLY MARGINAL 30-35KTS OF
EFFECTIVE SHEAR.
LOOKING AHEAD...SKIES SHOULD CLEAR BEHIND THE MORNING PRECIP
YIELDING ANOTHER MUGGY AFTERNOON AS DEWPOINTS CLIMB BACK TO NEAR
70F. INCREASED TEMPS SLIGHTLY ACROSS WEST OF I35...AND RAISED
DEWPOINTS AS WELL. OVERNIGHT NORTHWESTERLY WINDS WILL PUSH A COLD
FRONT THROUGH THE REGION SENDING DEWPOINTS BACK INTO THE UPPER 50S
BY SATURDAY MORNING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 AM CDT FRI JUL 25 2014
THE WEEKEND STARTS OUT ON A MILD NOTE...AS THE AREA REMAINS
SANDWICHED BETWEEN A SOUTHERN CONUS RIDGE TO THE SOUTH...AND A
MID LEVEL LOW TO THE NORTH IN SASKATCHEWAN/MANITOBA. THE RESULT WILL
BE SLIGHTLY WARMER THAN NORMAL HIGHS IN THE MID 80S ON
SATURDAY...FOLLOWED BY INCREASING PRECIPITATION CHANCES INTO
SUNDAY AS THE AFOREMENTIONED LOW DROPS SOUTH-SOUTHEAST FROM
SOUTHERN MANITOBA. AS IS COMMON WITH THESE TYPES OF
LOWS...PRECIPITATION CHANCES APPEAR THE HIGHEST FROM CENTRAL MN
INTO WI...WHERE FORCING/MOISTURE IS DEEPER. EXPECT SHOWERS WITH
ISOLATED THUNDERSTORMS ON SUNDAY...PARTICULARLY DURING THE AFTERNOON
HOURS AS DIURNAL HEATING AIDS DESTABILIZATION.
NEXT WEEK STARTS OUT ON A DRY AND MILD NOTE AS THE WEEKEND LOW
SHIFTS SOUTHEAST AND A BROAD SURFACE RIDGE BUILDS ACROSS THE
CENTRAL CONUS. THE LOCAL AREA REMAINS CRAMMED BETWEEN WESTERN
RIDGING AND EASTERN TROUGHING AT THE MID TO UPPER LEVELS OF THE
ATMOSPHERE...YIELDING COOLER THAN NORMAL HIGHS FROM MONDAY THROUGH
WEDNESDAY MOSTLY IN THE 70S...AND LOWS IN THE 50S.
THURSDAY AND FRIDAY BRING THE NEXT CHANCE FOR MEASURABLE
PRECIPITATION AS SHORTWAVE ENERGY BEGINS TO TRICKLE SOUTH ON THE
WESTERN PERIPHERY OF THE EASTERN CONUS TROUGH. CHANCES ARE NOT
HIGH AT THIS POINT GIVEN MODEST FORCING AND MOISTURE...BUT
SUFFICIENT FOR THE INCLUSION OF 20-30 POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1205 PM CDT FRI JUL 25 2014
ABUNDANT LOW LEVEL MOSITURE AHEAD OF INCOMING FRONT/TROUGH WILL
CONTINUE BKN MVFR CIGS FOR A COUPLE HOURS OR SO. THEN VFR OVER MN
PORTION OF THE CWA THROUGH THE REMAINDER OF THE PERIOD. SOME
THREAT OF FOG DEVELOPING AHEAD OF WEAK BOUNDARY IF THE SKY CLEARS
TO THE EAST. WILL CONTINUE TO MENTION THAT POTENTIAL AT KSTC-KRNH-
KEAU REGION. SOME THREAT OF THUNDER ALONG BOUNDARY AS WELL...BUT
WOULD BE ISOLD IF IT DID OCCUR. SFC HEATING LIMITED WITH CLOUDS TO
THE EAST AND MID LEVEL CAP IS EXPECTED TO HOLD. SOUTH/SOUTHWEST
WINDS BECOMING WEST/NW WITH FROPA...MAINLY WEST AS FRONT MOVES
EAST AND WEAKENS.
KMSP...
CIGS EXPECTED TO LIFT TO VFR THROUGH 19Z-20Z. THEN BECOMING SCT BY
EVENING WITH SOME MID/HIGH LEVEL CLOUDS INTO SATURDAY. FOG
POTENTIAL WILL BE LIMITED AS WEAK TROUGH EXPECTED TO MOVE THROUGH
THIS EVENING. SOUTHWEST TO WEST WINDS EXPECTED GENERALLY LESS THAN
10KTS THROUGH THE PERIOD. SOME POTENTIAL OF SHRA/TSRA INTO SAT
EVENING. WILL ACCESS THIS FOR NEXT FCST ISSUANCE.
/OUTLOOK FOR KMSP/
SUN...VFR WITH MVFR/SHRA POSSIBLE. WINDS NW AT 10G15KTS.
MON...VFR. WINDS N AT 5KTS.
TUE...VFR. WINDS N AT 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...LS
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1149 AM CDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 1146 AM CDT FRI JUL 25 2014
ISOLD TO WIDELY SCT SHOWERS ARE POPPING UP AND THEN DISSIPATING.
WITH THIS DIFFICULTY...HAVE A LOW POPS TO TRY AND ACCOUNT FOR THIS
ACTIVITY. STILL EXPECTING A FEW THUNDERSTORMS LATER THIS
AFTERNOON. REST OF THE FORECAST ON TRACK.
UPDATE ISSUED AT 903 AM CDT FRI JUL 25 2014
THE EARLY MORNING SHOWERS HAVE EXITED THE AREA. JUST A FEW
SPRINKLES REMAIN. HOWEVER...WITH THE UNSTABLE AIRMASS AND COLD
FRONT IN EASTERN ND...WAA/ISENTROPIC LIFT AHEAD OF SAID
FRONT...SHOWERS OR ISOLD THUNDERSTORMS MAY POP AT ANY TIME. HAVE
ADJUSTED POPS FOR THESE LATEST TRENDS.
UPDATE ISSUED AT 736 AM CDT FRI JUL 25 2014
UPDATED TO REFINE POPS AND REMOVE PRE-FIRST PERIOD BASED ON
CURRENT PRECIP AREA. THE SHOWERS AND THUNDERSTORMS SHOULD MOVE
SOUTH OUT OF THE FORECAST AREA BY 15Z. REST OF FCST UNCHANGED.
UPDATE ISSUED AT 430 AM CDT FRI JUL 25 2014
UPDATED TO INCREASE POPS ACROSS PORTIONS OF THE FORECAST AREA. AREA
OF SHOWERS AND THUNDERSTORMS MOVING ACROSS THOSE AREAS THIS
MORNING. THIS PRECIPITATION WILL END BY MID-MORNING. REST OF FCST UNCHANGED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 242 AM CDT FRI JUL 25 2014
SHORT TERM CONCERN IS PRECIPITATION CHANCE TODAY AND TONIGHT.
CURRENT SURFACE ANALYSIS INDICATES RAIN SHOWERS NORTH OF THE IRON
RANGE AND IN THE ARROWHEAD. THESE SHOWERS ARE ASSOCIATED WITH A WEAK
SHORTWAVE MOVING THROUGH THE AREA. THEY WILL CONTINUE MOVE
SOUTHEAST AND SLOWLY DISSIPATE EARLY THIS MORNING. THERE IS AN
AREA OF THUNDERSTORMS ALONG THE ND/SD/WRN MN BORDER MOVING ESE.
THE AREA HAS DECREASED IN INTENSITY OVER THE PAST HOUR. THE
NORTHERN EDGE OF THE PRECIPITATION MAY CLIP CASS AND CROW WING
COUNTIES THIS MORNING. A WEAK SURFACE TROUGH WILL MOVE THROUGH MN
TODAY AND NW WI TONIGHT. IT WILL BRING ANOTHER ROUND OF SHOWERS
AND THUNDERSTORMS. THERE WILL BE SOME INCREASED INSTABILITY WITH
THE TROUGH THIS AFTERNOON AND EVENING. MUCAPES ARE
1500-2000...SHEAR IS 20-40...AND SOME SUN TODAY. SPC HAS THE
FORECAST AREA IN A 5% PROBABILITY FOR WIND/HAIL WITH THE MARGINAL
INSTABILITY.
AN AREA OF WEAK HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE
WEST LATE THIS EVENING. THIS WILL END THE THREAT FOR PRECIPITATION
FOR LATE FRIDAY NIGHT AND SATURDAY. HOWEVER..BY THE AFTERNOON...AN
AREA OF LOW PRESSURE ALONG WITH A UPPER TROUGH WILL MOVE INTO
WESTERN MINNESOTA AND WILL EFFECT THE REGION SATURDAY NIGHT.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 242 AM CDT FRI JUL 25 2014
THE MODELS ARE IN PRETTY GOOD AGREEMENT THROUGH MUCH OF THE
PERIOD. AN UPPER TROUGH OVER SOUTHERN MANITOBA SATURDAY EVENING
WILL DROP INTO NORTHERN MINNESOTA BY 12Z SUN...THEN CONTINUE INTO
SOUTHERN WISCONSIN BY SUNDAY EVENING. A SURFACE LOW/TROUGH AXIS
WILL BE ASSOCIATED WITH THIS UPPER WAVE. SHOWERS AND A FEW
THUNDERSTORMS WILL INCREASE IN COVERAGE SATURDAY NIGHT INTO SUNDAY
MORNING...THEN DECREASE FROM NORTH TO SOUTH SUNDAY
AFTERNOON/EVENING. SUNDAY NIGHT SHOULD BE DRY. WE HAVE THE HIGHEST
POPS OVER THE EASTERN PORTION OF THE NORTHLAND LATE SATURDAY NIGHT
INTO SUNDAY MORNING.
HIGH PRESSURE WILL THEN LEAD TO MAINLY DRY CONDITIONS SUNDAY NIGHT
INTO MONDAY NIGHT. THERE MAY BE A FEW SHOWERS TUESDAY INTO WEDNESDAY
OVER THE EASTERN HALF OF THE NORTHLAND WITH A SERIES OF SHORTWAVES
MOVING THROUGH IN THE NORTHERLY FLOW ALOFT. WE ALSO HAVE A SMALL
CHANCE FOR SHOWERS/STORMS THURSDAY FOR MOST AREAS.
THE PERIOD WILL START OUT WITH BELOW NORMAL TEMPERATURES
SUNDAY...WITH HIGHS IN THE MID SIXTIES TO LOWER SEVENTIES.
TEMPERATURES WILL THEN MODERATE THROUGH THE REST OF THE
PERIOD...REACHING THE UPPER SEVENTIES TO LOWER EIGHTIES BY THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 632 AM CDT FRI JUL 25 2014
SHOWERS AND A FEW THUNDERSTORMS WERE MOVING THROUGH
CENTRAL/EASTERN PORTIONS OF THE NORTHLAND EARLY THIS MORNING. WE
EXPECT A LULL IN COVERAGE TO DEVELOP THIS MORNING...THEN
ADDITIONAL DEVELOPMENT THIS AFTERNOON AHEAD OF THE SURFACE
BOUNDARY THAT WILL ONLY MOVE SLOWLY FROM WESTERN MINNESOTA EARLY
THIS AFTERNOON TOWARD THE EAST.
AN AREA OF MVFR/IFR CEILINGS HAVE DEVELOPED OVER WEST CENTRAL
MINNESOTA INTO CENTRAL MINNESOTA. THE RAP IS SUGGESTS THESE
CEILINGS WILL SPREAD NORTH AND EAST TODAY. HOWEVER...THE COVERAGE
CURRENTLY IS NOT AS GREAT AS THE RAP SUGGESTS. WE FEEL MOST
CONFIDENT KBRD WILL SEE THE LOWER CEILINGS AND ADDED A TEMPO GROUP
FOR THE REST OF THE TAF SITES BY MID TO LATE MORNING.
THE COVERAGE OF THE PRECIPITATION WILL DIMINISH THIS EVENING AND
SOME FOG WILL BE POSSIBLE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 75 59 82 59 / 50 30 50 50
INL 76 57 81 56 / 40 50 50 60
BRD 80 58 84 60 / 40 10 30 40
HYR 76 62 85 58 / 50 30 30 50
ASX 77 61 81 57 / 30 40 40 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...STEWART
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1255 PM CDT Fri Jul 25 2014
.UPDATE:
Issued at 950 AM CDT Fri Jul 25 2014
Complex of TSRA continues to maintain itself rather well on its
backside over northeast MO and eastern IA, where lo level jet and
better instability are feeding it. An isolated threat for large
hail exists, but should decrease heading deeper into the morning.
Overall health of TSRA complex should also begin to fail as we
head into the afternoon hours, with strengthening cap of warm air
to the west and weakening lo level jet. This rain should have a
somewhat easier time of advecting in IL versus MO and updated the
forecast accordingly, although will no doubt need to tweak
expected coverage over the next couple hours.
Also adjusted temps further down in IL, where readings should stay
below 80F, but enough recovery expected in the west and south to
maintain previous forecast.
TES
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 330 AM CDT Fri Jul 25 2014
Convective trends and the extent of pops are the biggest forecast
challenge today. Thunderstorms have blossomed within the last
several hours across central Iowa at the terminus of a stout
southwesterly LLJ, and along the eastern periphery of elevated
instability, deeper moisture and steep mid level lapse rates.
Short range guidance shows the LLJ slowly veering this morning,
providing favorable moisture transport and forcing as the flow
aloft and northwestely deep layer shear steer the activity east
and southeastward. The HRRR runs since 01Z have been very emphatic
supporting this scenario bringing showers and thunderstorms into
northeast Missouri and west central Illinois. I have increased
pops into the likely range in this area tapered to slight chances
just north of interstate 70. Believe that most of this activity
will be east of the MS river by early afternoon and exiting the
CWA shortly thereafter. This activity will likely delay/impeed the
northward retreat of the warm front, however in central MO there
should be no issue where highs will be around 90.
Glass
.LONG TERM: (Tonight through Thursday)
Issued at 330 AM CDT Fri Jul 25 2014
The warm front should have exited the entire CWA by early evening
while the upstream cold frontal system will be slowly advancing
and stretching from the upper MS valley into the central Plains.
High heights aloft and warm mid level temperatures should suppress
any surface-based storm development within the large warm sector
spanning the CWA, however the area will remain subject to an
elevated shower and thunderstorm threat. While there is no defined
focus for thunderstorms, a westerly LLJ will be poised across the
area in conjunction with steep mid level lapse rates and good
elevated instability supporting a least a chance pop. These same
unfocused conditions will exist on Saturday morning. The set-up
should improve on Saturday afternoon. Strong surface heating
should yield temperatures well into the 90s with dew points in the
70s. This will result in afternoon heat indices in the 100-104 degree
range, just below advisory criteria. We will need to monitor this
closely as just a bit higher dew points and/or temperatures and a
heat advisory will be warranted. The aforementioned conditions along
with the presence of steep mid level lapse rates will yield very
unstable conditions during the afternoon/evening. There are
indications that the combo of heating and a disturbance in the
west northwest flow aloft should sufficiently weaken the cap
allowing for robust thunderstorm development along the west-east
oriented front stretching in the vicinity of far northern MO
through central IL into the OH valley. How far west development
occurs is uncertain but height falls/cooling aloft on Saturday
night could aid this process. Deep layer shear and instability is
quite favorable for organized severe with damaging winds the most
apparent severe threat at this time. I have some low pops on
Sunday ahead of the advancing front, but the overall threat of
precipitation will be lower as compared to the Saturday night.
Cooler and drier air will advect in earnest into the area on Sunday
night with a large surface high settling into the Nation`s
midsection on Monday. An unseasonably deep upper trof over eastern
NOAM through the first part of next week will keep the large
surface high in control and allow for another period of below
average temperatures as we exit July and head into August.
Glass
&&
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1255 PM CDT Fri Jul 25 2014
VFR conditions are expected to prevail outside of TSRA at the TAF
sites thru the valid period. TSRA expected to weaken as it moves
into STL metro with some activity expected to edge into the
northern vicinities of SUS and STL before final anticipated
dissolution. The TSRA is in the process of exiting UIN now. After
this, very iffy on TSRA chances heading into tonight and thru the
first part of Saturday...enough to preclude mention in TAFs.
Otherwise, look for veering wind directions from SE to SW.
Specifics for KSTL: VFR thru the period outside of TSRA with
veering SE winds to SW by Saturday. Current TSRA activity still
expected to fall apart before reaching the aerodrome, but believe
something will edge the northern vicinity before doing so.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
100 PM EDT FRI JUL 25 2014
.SYNOPSIS...
A STALLED FRONT WILL BECOME INTERTWINED WITH THE SEABREEZE TODAY.
THE FRONT WILL LIFT NORTH AND DISSIPATE TONIGHT. HIGH PRESSURE WILL
FOLLOW AND BRING HOT...HUMID AND SULTRY CONDITIONS THIS WEEKEND AND
ON MONDAY. THE NEXT COLD FRONT WILL DROP ACROSS THE AREA TUESDAY. IN
ITS WAKE...COOLER AND DRIER CONDITIONS WILL OVERSPREAD THE AREA FOR
THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM FRIDAY...THICK CLOUDS HAVE STUBBORNLY HELD ON NORTH OF
THE STALLED FRONT. THIS OBVIOUSLY HAS HAD IMPACTS ON TEMPERATURES
AND ALSO WIND DIRECTIONS AS THERE IS NO SEABREEZE CIRCULATION TO
SPEAK OF YET. HIGHS HAVE BEEN ADJUSTED DOWNWARD BY ANOTHER 1-2
DEGREES IN MOST AREAS...WITH AIR TEMPERATURES NOW EXPECTED TO REMAIN
BELOW OCEAN WATER TEMPERATURES AT BEACHES TODAY. (HOW OFTEN DOES
THAT HAPPEN IN JULY?)
CONVECTION HAS BEGUN DEVELOPING ALONG THE FRONT ACROSS WILLIAMSBURG
AND GEORGETOWN COUNTIES IN SC. FORECAST POPS NEAR THE SANTEE RIVER
ARE 60-80 PERCENT WITH AROUND HALF AN INCH OF AREAL RAINFALL TOTALS
EXPECTED. ISOLATED SPOTS WILL UNDOUBTEDLY PICK UP 2-3 INCHES ON ONE
SIDE OR OTHER OF THE SANTEE RIVER. PREVIOUS DISCUSSION FROM 1000 AM
FOLLOWS...
THE COLD FRONT HAS PUSHED SURPRISINGLY FAR TO THE SOUTH AND IS
EASILY VISIBLE ON SATELLITE IMAGERY AS A WALL OF LOW STRATUS AND
EVEN SOME PATCHY FOG. THIS BOUNDARY HAS PUSHED INTO MYRTLE
BEACH...CONWAY...AND KINGSTREE SC IN THE PAST HOUR AND SHOULD STALL
SHORTLY IN THE VICINITY OF PAWLEYS ISLAND...ANDREWS AND GREELEYVILLE
SC. MODELS SHOW THIS FRONT RETURNING NORTHWARD THIS AFTERNOON AS
HIGH PRESSURE MOVES OFF THE MID-ATLANTIC COAST...ALSO HELPED BY A
WEAK SEABREEZE CIRCULATION THAT SHOULD ADD SOME NORTHBOUND MOMENTUM
TO OUR LOW-LEVEL WINDS.
DIFFERENTIAL HEATING ALONG THE FRONT SHOULD HELP INTENSIFY LOW-LEVEL
CONVERGENCE BY EARLY AFTERNOON...AND THE LATEST FEW HRRR MODEL RUNS
PLUS LAST NIGHT`S NSSL WRF SHOW THUNDERSTORMS INITIATING ACROSS
GEORGETOWN AND HORRY COUNTIES EARLY THIS AFTERNOON. ALTHOUGH CELL
MOTION SHOULD BE EASTWARD AT 10-15 MPH...STORMS WILL INGEST THE
DRIER AIR ALOFT IN DOWNDRAFTS CREATING A COMPLEX NETWORK OF
BOUNDARIES THAT WILL ULTIMATELY DETERMINE STORM MOTION AND FUTURE
DEVELOPMENT. MY HIGHEST POPS (60-70 PERCENT) ARE CENTERED ACROSS
SOUTHERN HORRY COUNTY...WITH LOWER POPS (30-50 PERCENT) EXTENDING
INTO THE NORTHERN PEE DEE REGION AND SE NORTH CAROLINA.
WATER VAPOR IMAGERY SHOWS THE MID LEVELS HAVE DRIED SINCE YESTERDAY
EVENING. THE 12Z MHX SOUNDING WAS DOWN TO 1.75 INCHES PRECIPITABLE
WATER WITH AROUND 1.9 INCHES ON THE CHS SOUNDING. THE BULK OF THIS
DRYING IS ABOVE THE 700 MB LAYER. 0-6 KM BULK SHEAR HAS DECREASED
FROM YESTERDAY AS HAS OVERALL INSTABILITY VALUES WHICH ARE
ANTICIPATED TO AVERAGE 1500-2500 J/KG TODAY VERSUS 3000-4000 J/KG
YESTERDAY.
I HAVE BUMPED DOWN TEMPERATURES BY A COUPLE DEGREES WHERE CLOUDS
THIS MORNING PLUS ONSHORE WINDS THIS AFTERNOON WILL HELP HOLD DOWN
HEATING. OTHERWISE NO SIGNIFICANT CHANGES ARE PLANNED.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...MODELS CONTINUE WITH THE ONGOING LONGWAVE
UPPER PATTERN THIS PERIOD...WITH TROFFING ALOFT ACROSS THE
EASTERN 1/3RD OF THE U.S. AND RIDGING ALOFT FOR THE WESTERN 2/3RDS
OF THE U.S. THE UPPER TROF AXIS...NOT AS AMPLIFIED AS WAS EARLIER
IN THE WEEK...IS PROGGED TO A POSITION JUST OFF THE CAROLINA
COASTS...BASICALLY ALONG THE EASTERN SEABOARD. AT THE SFC...MODELS
INDICATE THE SFC FRONT WILL DECAY ACROSS THE AREA ON SATURDAY.
THIS WILL LEAVE THE FA UNDER WEAK RIDGING FROM THE ATL
WATERS...AND THE FORMATION OF THE PIEDMONT TROF ACROSS THE CENTRAL
CAROLINAS DURING SATURDAY.
FOR SUNDAY THRU SUNDAY NIGHT...THE MODELS REMAIN IN GOOD
AGREEMENT WITH THE AMPLIFICATION OF BOTH THE UPPER TROF
OVERHEAD...AND THE UPPER RIDGING THAT IS CURRENTLY AFFECTING THE
WESTERN 2/3RDS OF THE U.S. A S/W TROF IS PROGGED TO DIVE OUT OF
CENTRAL CANADA EARLY SUNDAY...AND BASICALLY AID IN THE
AMPLIFICATION PROCESS OF THE FLOW ALOFT ACROSS THE CONTERMINOUS
U.S. AT THE SFC...THE WEAK RIDGING FROM OFF THE COAST WILL GET
SHUNTED SOUTH OF THE AREA. THE PIEDMONT SFC TROF WILL GAIN SOME
STRENGTH AS MODELS CONTINUE WITH THE TIGHTENING OF THE GRADIENT
ASSOCIATED WITH THE PIEDMONT TROF.
THIS PERIOD WILL BE HIGHLIGHTED BY THE 3HS...HAZY HOT AND HUMID.
VERY LITTLE IN THE WAY OF CONVECTION IS EXPECTED EXCEPT FOR ISOLATED
CHANCES ALONG THE SEA BREEZE BOUNDARY...AND ANY CONVECTION THAT
DRIFTS TO THE FA AFTER FIRING UP ALONG THE PIEDMONT TROF. THUS
20-30 POPS ARE THE HIGHEST WILL GO THIS PERIOD. OVERALL...WARMER
TEMPS ALOFT AS WELL AS SUBSIDENCE ALOFT...WILL BOTH AID IN KEEPING
A LID ON CONVECTION THIS WEEKEND. VARIOUS MODEL MOS GUIDANCE DOES
PAINT WIDESPREAD 90+ DEGREE TEMPS FOR SATURDAY...AND EVEN HOTTER
ON SUNDAY. HAVE GONE ALONG WITH THESE NUMBERS ESPECIALLY WITH THE
DECENT W-NW DOWNSLOPE FLOW ALOFT. IN FACT...HEAT ADVISORY CRITERIA
WILL LIKELY BE MET ON SUNDAY WITH HIGHS WELL INTO THE 90S ALONG
WITH HUMIDITY LEVELS HAVING INCHED BACK UPWARDS. THUS THE 2
COMBINED PROVIDE FORECAST HEAT INDICES REACHING A WIDESPREAD
104-106 DEGREES ACROSS THE FA.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM THURSDAY...MID LEVEL TROUGH WILL DOMINATE MUCH OF THE
PERIOD KEEPING TEMPERATURES ACROSS THE REGION BELOW CLIMO. THE
EXCEPTION WILL BE ON SUN WITH MID LEVEL RIDGE TO THE WEST
EXTENDING EAST. 850 TEMPS WILL FLIRT WITH 20-22C WHICH SHOULD
PRODUCE HIGHS IN THE MID TO UPPER 90S. DESPITE THE HOT TEMPS DO NOT
THINK THERE WILL BE MUCH CONVECTION AROUND. WESTERLY MID LEVEL FLOW
AND SUBSIDENCE ON THE RIDGES PERIPHERY WILL KEEP MID LEVELS DRY.
CANNOT RULE OUT ISOLATED CONVECTION...ESPECIALLY LATER IN THE DAY
ASSOCIATED WITH THE PIEDMONT TROUGH BUT SEE NO REASON TO GO ABOVE
INHERITED SILENT POP.
COLD FRONT MOVES INTO THE AREA LATE MON...PUSHED BY IMPRESSIVE MID
LEVEL TROUGH. DOES NOT LOOK LIKE MON WILL BE AS HOT AS SUN GIVEN
INCREASED MID LEVEL MOISTURE AND MORE WIDESPREAD CONVECTION LATER IN
THE DAY...JUST AHEAD OF THE FRONT. SHOULD THE FRONT BE DELAYED A BIT
MON COULD END UP AS HOT AS SUN GIVEN 850 TEMPS HANGING IN THE LOW
20C RANGE FOR MUCH OF THE DAY. LATER MON INTO TUE WILL BE THE MOST
ACTIVE PART OF THE PERIOD CONVECTIVELY SPEAKING AND WILL MAINTAIN
INHERITED HIGH CHC POP.
MID LEVEL TROUGH AXIS WILL REMAIN WEST OF THE AREA THROUGH THE
PERIOD WITH THE FRONT STALLING NOT TOO FAR OFF THE COAST. INITIALLY
MID LEVELS ARE DRY BUT INCREASING MOISTURE ALOFT WILL RESULT IN A
SLOW INCREASE IN POP THROUGH THE MIDDLE OF NEXT WEEK. TEMPS WILL RUN
A LITTLE BELOW CLIMO LATE IN THE PERIOD.
&&
.AVIATION /12Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...EXPECT VFR THROUGH THIS EVENING WITH INCREASING CHANCES
FOR SHRA/TSRA THROUGH THIS AFTERNOON...ESPECIALLY NEAR & SOUTH OF
MYRTLE BEACH. MVFR/IFR POSSIBLE LATE OVERNIGHT INTO THE EARLY
MORNING HOURS DUE TO FOG/LOW CIGS...IMPROVING TO VFR SATURDAY LATE
MORNING.
MVFR/IFR CIGS HAVE PERSISTED ACROSS THE AREA..AND MAY CONTINUE TO DO
SO AT A FEW OF THE TAF SITES FOR THE NEXT HOUR BEFORE IMPROVING TO
MVFR AND THEN VFR AS THE CLOUD LAYER BURNS OFF. NORTHEAST WINDS WILL
BECOME SOUTHEAST ALONG THE COAST AROUND 10 KTS LATER THIS AFTERNOON
WITH INLAND SITES CONTINUING A LIGHT NORTHEAST WIND. LATEST RADAR
IMAGERY DEPICTS INCREASING SHRA/TSRA NEAR GEORGETOWN AND CHARLESTON
SC...AND COVERAGE AND CHANCES WILL INCREASE THROUGHOUT THE REST OF
THE AFTERNOON AS THE SEA BREEZE AND THE FRONT INTERACT. ANY
SHRA/TSRA COULD PRODUCE HEAVY RAINFALL OR FLIGHT CAT
RESTRICTIONS...AND WILL TAPER OFF LATER THIS EVENING. OVERNIGHT INTO
THE EARLY MORNING HOURS WINDS WILL BECOME LIGHT AND VARIABLE AND
MVFR/IFR IS POSSIBLE DUE TO FOG AT ALL SITES...WHICH WILL DISSIPATE
SATURDAY MORNING GIVING WAY TO VFR WITH LIGHT WINDS.
EXTENDED OUTLOOK...SHOWERS/TSTMS/TEMPO MVFR POSSIBLE SUNDAY AND
MONDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM FRIDAY...LATEST MODELS AND OBSERVATIONS INDICATE
PERHAPS EVEN A SLOWER RETURN NORTHWARD FOR THE FRONT...MAINLY
BECAUSE THICK CLOUD COVER INLAND HAS REDUCED THE RATE TEMPERATURES
ARE RISING WHICH HAS VIRTUALLY ELIMINATED ANY SEABREEZE WINDS SO
FAR. NORTH OF WINYAH BAY NE WINDS SHOULD BECOME EASTERLY IN A FEW
HOURS...THEN WILL VEER MORE SOUTHERLY TONIGHT AS THE FRONT STARTS TO
MOVE NORTHWARD. MARINERS SHOULD BEWARE FOR INCREASING SHOWER AND
T-STORM COVERAGE IN THE GEORGETOWN/MURRELLS INLET VICINITY THIS
AFTERNOON. PREVIOUS DISCUSSION FROM 1000 AM FOLLOWS...
THE COLD FRONT HAS PUSHED ALL THE WAY DOWN TO MYRTLE BEACH THIS
MORNING WITH NORTH WINDS GUSTING AS HIGH AS 15 KNOTS ACROSS THE
WATERS OF SOUTHEASTERN NORTH CAROLINA. THE FRONT SHOULD STALL SOON
NEAR MURRELLS INLET OR PAWLEYS ISLAND...THEN WILL RETURN NORTHWARD
THIS AFTERNOON. THE BIGGEST CHANGE TO THE FORECAST REGARDS WIND
DIRECTION THIS MORNING WHICH ARE MAINLY NORTH TO NORTHEAST BEHIND
THE FRONT...BUT REMAIN SOUTHWESTERLY ACROSS THE GEORGETOWN COUNTY
WATERS. LATEST MODELS SHOW A SLOWER VEERING OF THE SURFACE WINDS
NORTH OF THE FRONT THIS AFTERNOON...WITH DIRECTIONS REMAINING EAST
FOR A LONGER PERIOD OF TIME THAN EARLIER THOUGH. FORTUNATELY WIND
SPEEDS SHOULD REMAIN FAIRLY LIGHT.
SEAS ARE RUNNING 2-3 FT CURRENTLY...AND WITH NO SIGNIFICANT INCREASE
EXPECTED IN WIND SPEEDS THROUGH THE DAY I HAVE TRIMMED ABOUT A FOOT
OFF THE PREVIOUS FORECAST. A 9-SECOND SOUTHEAST SWELL CONTINUES.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...FOR SATURDAY...THE AREA WATERS WILL BE
UNDER THE INFLUENCE OF A DECAYING FRONTAL BOUNDARY...RESULTING IN
MAINLY A VARIABLE WIND DIRECTION FOR MUCH OF THE DAY...AND WITH
THE LACK OF ANY GRADIENT...SPEEDS WILL GENERALLY BE 10 KT OR LESS.
FOR SUNDAY...THE AMPLIFYING FLOW ALOFT WILL RESULT IN A
STRENGTHENING SFC PIEDMONT TROF ACROSS THE CENTRAL CAROLINAS AND
THE RIDGING FROM THE BERMUDA HIGH BEING SHUNTED WELL SOUTH OF THE
AREA WATERS. THIS WILL PRODUCE A TIGHTENING SFC PG ACROSS THE
CAROLINAS INCLUDING THE COASTAL WATERS. THE SFC PRESSURE PATTERN
WILL YIELD A SFC SW-WSW WIND DIRECTION...WITH INCREASING SPEEDS
SUNDAY INTO SUNDAY NIGHT. SCEC AND/OR SCA CONDITIONS WILL LIKELY
BE MET SUNDAY AFTERNOON AND/OR NIGHT.
SIGNIFICANT SEAS WILL BE AT THEIR EBB DURING SATURDAY WITH AN ESE-
SE 1-3 FOOT GROUND SWELL DOMINATING THE WATERS. THE AFTN/EVENING SEA
BREEZE CIRCULATION WILL ADD SOME WIND CHOP NEAR SHORE. FOR
SUNDAY...LOOK FOR WIND DRIVEN WAVES TO STEADILY INCREASE IN BOTH
HEIGHT AND PERIODS...AND WILL LIKELY BE THE DOMINANT PLAYER IN THE
SIGNIFICANT SEAS FORMULA. WILL ADVERTISE 6 FOOTERS ACROSS THE
LOCAL WATERS LATE SUNDAY AFTERNOON BUT MORE LIKE SUNDAY NIGHT.
.LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 PM THURSDAY...MODEST SW FLOW ON SUN WILL INCREASE INTO MON
AS GRADIENT TIGHTENS AHEAD OF ADVANCING COLD FRONT. SPEEDS LATER SUN
MAY APPROACH SCEC THRESHOLDS AS PIEDMONT TROUGH STRENGTHENS. SCA
HEADLINES SEEM CERTAIN FOR AT LEAST MON AND POSSIBLY SUN NIGHT AS
PROLONGED STRONG SOUTHWEST FLOW BUILDS SEAS TO 4 TO 6 FT. FRONT
MOVES ACROSS THE WATERS MON NIGHT WITH NORTHERLY FLOW DEVELOPING.
GRADIENT RELAXES BEHIND THE FRONT AND SPEEDS WILL DROP UNDER 10 KT
BY MIDDAY TUE. FRONT ENDS UP STALLED JUST EAST OF THE WATERS WITH
THE PROXIMITY TO THE FRONTAL ZONE KEEPING GRADIENT WEAK AND WINDS
LIGHT AND VARIABLE. SEAS WILL DROP TO 3 TO 4 FT BEHIND THE FRONT AND
BELOW 3 FT BY THE END OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...DCH
LONG TERM...III
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1237 PM CDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 1237 PM CDT FRI JUL 25 2014
CLOUDS WERE MOVING OUT OF THE JAMES RIVER VALLEY AND SUNNY SKIES
ARE EXPECTED ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS
AFTERNOON. CURRENT FORECAST ON TRACK FOR THE AFTERNOON.
UPDATE ISSUED AT 938 AM CDT FRI JUL 25 2014
AREA OF LOW CLOUDS REMAINED ALONG OR EAST OF
CARRINGTON/BISMARCK/LINTON/FORT YATES LINE...AND THIS CLOUD SHIELD
SHOULD CONTINUE MOVING EAST AND/OR ERODING FROM THE WEST AS DRY
HIGH PRESSURE PUSHES INTO THE REGION WITH WEST/NORTHWEST WINDS.
REST OF FORECAST FOR TODAY ON TRACK.
UPDATE ISSUED AT 636 AM CDT FRI JUL 25 2014
NARROW BAND OF CLOUDS REMAIN ACROSS CENTRAL NORTH DAKOTA AND THESE
HAVE BEEN ERODING THROUGH THE MORNING. SKIES WILL CONTINUE TO
CLEAR ACROSS THE REGION. KEPT ISOLATED SHOWERS SOUTH CENTRAL FOR A
FEW HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT FRI JUL 25 2014
THE LATEST SURFACE ANALYSIS PLACES A COLD FRONT FROM NEAR SHERWOOD
TO JUST EAST OF MINOT AND SOUTH TO NEAR LINTON. WEAK PRESSURE
FALLS CONTINUE AHEAD OF THE FRONT WITH AN AREA OF SHOWERS AND
ISOLATED THUNDERSTORMS MOSTLY OVER NORTH CENTRAL NORTH DAKOTA.
THE FOG/STRATUS LOOP INDICATES POCKETS OF LOWER CLOUDS BEHIND THE
FRONT BUT STEADILY MOVING EAST. THE HRRR CEILING FORECAST HAS A
GOOD HANDLE ON THE CURRENT SITUATION AND ALSO PROGRESSIVELY MOVES
THE BACK EDGE OF THE LOWER CLOUDS THROUGH THE JAMES RIVER VALLEY
BY 14Z. WATER VAPOR IMAGERY LOOP SHOWS AN UPPER LOW SPINNING OVER
SOUTHEASTERN ALBERTA WITH A DRIER WESTERLY FLOW INTO NORTH DAKOTA.
ALBEIT A FEW DISTURBANCES ARE EMBEDDED WITHIN THE FLOW BUT THESE
ARE NOT EXPECTED TO HAVE MUCH OF AN IMPACT DURING THE SHORT TERM
PERIOD. THUS EXPECT A MOSTLY SUNNY SKY WITH BREEZY CONDITIONS AS
WESTERLY WINDS WILL RANGE BETWEEN 15 AND 25 MPH. HIGHS TODAY WILL
RANGE FROM THE UPPER 70S NORTH TO LOWER 80S SOUTH. AN AREA OF
SHOWERS WILL DEVELOP OVER SOUTH DAKOTA TONIGHT AND REMAIN SOUTH OF
NORTH DAKOTA/SOUTH DAKOTA BORDER. LATE FRIDAY NIGHT THERE WILL
ALSO BE AN AREA OF SHOWERS SLIDING INTO SOUTHERN SASKATCHEWAN AND
MANITOBA...BUT THESE SHOWERS WILL REMAIN NORTH OF THE BORDER
THROUGH 12Z SATURDAY. THUS DRY CONDITIONS WILL PREVAIL THROUGH
FRIDAY NIGHT. OVERNIGHT LOWS FRIDAY NIGHT WILL BE IN THE 50S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 335 AM CDT FRI JUL 25 2014
THE MAIN FEATURE OF THIS FORECAST PERIOD WILL BE THE UPPER LEVEL
LOW FORECAST BY MODELS TO MOVE SOUTHEAST FROM SASK THROUGH
MINNESOTA EVENTUALLY MERGING WITH A LONGWAVE TROUGH OVER THE
EASTERN US. AS THIS PROCESS TAKES PLACE THE LOW WILL USHER IN
COOLER SURFACE TEMPERATURES AND MORE STABLE AIR. SCATTERED SHOWERS
AND POSSIBLE AN ISOLATED THUNDERSTORM ARE FORECAST FOR THE NORTH
AND EAST ON SATURDAY. SUNDAY THROUGH TUESDAY WILL BE DRY AND
COOLER WITH HIGHS AS COOL AS THE UPPER 60S ACROSS THE TURTLE
MOUNTAINS SUNDAY...AND 70S SOUTH AND WEST. EVENTUALLY A HIGH
AMPLITUDE FLOW DEVELOPS ACROSS NORTH AMERICA WITH A LONGWAVE
TROUGH OVER THE EASTERN US AND A RIDGE OVER THE WEST BY THE MIDDLE
OF NEXT WEEK. THIS LEAVES THE NORTHERN PLAINS IN A SLIGHTLY
ANTICYCLONIC NORTHWEST FLOW REGIME THAT SHOULD SUPPRESS MUCH OF
THE CONVECTION WEDNESDAY AND THURSDAY WITH JUST ISOLATED
THUNDERSTORMS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1237 PM CDT FRI JUL 25 2014
MVFR/VFR CIGS MOVING OUT OF THE KJMS AREA AND WILL KEEP MENTION OF
CIGS OUT AT 18Z. OTHERWISE SKC WILL DOMINATE THE TERMINALS THROUGH
AT LEAST 06Z...WHEN NORTHERN TAF SITES OF KISN/KMOT MAY BE IMPACTED
BY SCATTERED CLOUDS OF VFR HEIGHT...BECOMING BROKEN AROUND 13Z-14Z.
WESTERLY WINDS GUSTING UP TO 25KT WILL SUBSIDE BY 02Z
SATURDAY...THEN WINDS INCREASE AGAIN AFT 12Z SATURDAY WITH GUSTS
SATURDAY AFTERNOON OVER 25 KNOTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...KS
LONG TERM...WAA
AVIATION...JV
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1235 PM CDT FRI JUL 25 2014
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...
A WEAK SHEAR AXIS IN THE UPPER ATMOSPHERE...COMBINED WITH AMPLE
BOUNDARY LAYER MOISTURE...MAY AID IN THE DEVELOPMENT OF ISOLD
-SHRA/TSRA ACROSS THE REGION THIS AFTERNOON. IT LOOKS LIKE
CONVECTION COULD DEVELOP BETWEEN 25/1700-1900 IN VICINITY OF US-77
CORRIDOR...WITH ADDITIONAL DEVELOPMENT POSSIBLE FARTHER W BY 25/2100
UTC AS THE SEABREEZE MOVES W. CIGS MAY BE LOCALLY REDUCED INTO MVFR
TERRITORY FOR AN HOUR OR SO IN VICINITY OF ANY -SHRA/TSRA. NO
-SHRA/TSRA ARE ANTICIPATED SATURDAY AS THE BOUNDARY LAYER STARTS TO
DRY.
OVERALL...THE ODDS OF SEEING -SHRA/TSRA AT THE MAJOR VALLEY
TERMINALS ARE VERY LOW THIS AFTERNOON. I PLAN ON CONTINUING A DRY
FORECAST FOR KBRO...KHRL...AND KMFE FOR THE 1800 UTC TAF PACKAGE...
WITH ONLY SCTD CU ANTICIPATED THROUGH SUNSET.
GUSTY SE WINDS AROUND 15 KTS SHOULD DIMINISH AFTER SUNSET...THEN
INCREASE AGAIN BY MID-MORNING SATURDAY. /53/
&&
.PREV DISCUSSION... /ISSUED 1123 AM CDT FRI JUL 25 2014/
DISCUSSION...
QUIET WEATHER CONDITIONS ACROSS THE FORECAST AREA LATE THIS
MORNING...WITH HARDLY A CLOUD IN THE SKY. WATER VAPOR
IMAGERY...AND SUBJECTIVE ANALYSES CONTINUE TO INDICATE AN UPPER-
LEVEL SHEAR AXIS EXTENDING FROM THE NORTHERN GULF COAST INTO OUR
AREA. ALL INDICATIONS SUGGEST THAT BOUNDARY LAYER MOISTURE SHOULD
REMAIN SUFFICIENT TO ALLOW SOME ISOLATED CONVECTION TO DEVELOP
THIS AFTERNOON.
CONVECTION COULD DEVELOP NEAR THE IH-69E/US-77 CORRIDOR BETWEEN
NOON AND 2 PM AS THE SEABREEZE STARTS TO MOVE INLAND. HOWEVER...WITH
THE DEEPEST MOISTURE EXPECTED TO REMAIN AROUND THE IH-69C/US-281
CORRIDOR...THE GREATEST COVERAGE IS EXPECTED TO BE IN THIS REGION
THIS AFTERNOON AS SEABREEZE MOVES WESTWARD. THIS TREND IS
GENERALLY SUPPORTED BY RECENT HRRR MODEL RUNS. ALL THAT
SAID...PRECIPITATION PROBABILITIES AND TIMING HAVE BEEN ADJUSTED SLIGHTLY.
OTHERWISE...THE ONGOING FORECAST APPEARS TO BE IN DECENT SHAPE
WITH ONLY MINOR ADJUSTMENTS MADE HERE AND THERE TO ACCOUNT FOR
TRENDS IN THE OBSERVATIONAL DATA. ANY CHANGES TO FORECAST HIGH OR
LOW TEMPERATURES ARE PROVIDED BELOW FOR YOUR PERUSAL.
ISC GRIDS HAVE BEEN SENT AND SHOULD BE POSTED TO THE INTERNET.
UPDATED TEXT FORECAST PRODUCTS WILL BE ISSUED SHORTLY. /53/
PREV DISCUSSION... /ISSUED 629 AM CDT FRI JUL 25 2014/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...VFR CONDITIONS PREVAIL TODAY INTO TONIGHT WITH HIGH
PRESSURE CENTERED OVER NORTHWEST TEXAS. MID TO UPPER LEVEL
NORTHEAST FLOW WITH DRIER AIR TO LIMIT CLOUD COVER TO FEW-SCT. A
WEAKENING UPPER LOW PRESSURE TROUGH REMAINS CLOSE ENOUGH FOR
ISOLATED SHOWERS OR EVEN A THUNDERSTORM TO DEVELOP LATER THIS
AFTERNOON. LITTLE TO NO IMPACT ANTICIPATED AT THE 3 TERMINALS
SITE. LIGHT SOUTHEAST FLOW BECOMING MODERATE AS THE SEA BREEZE
MOVES EAST TO WEST BETWEEN 19-23Z
PREV DISCUSSION... /ISSUED 406 AM CDT FRI JUL 25 2014/
SHORT TERM /TODAY THROUGH SATURDAY/...WEAKENING 250MB SHEAR LINE
LIES ALONG THE TEXAS COAST WITH THE BASE OF THE TROUGH NOTED OVER
OUR WESTERN ZONES THIS MORNING. CENTER OF HOT RIDGE OVER THE TEXAS
PANHANDLE WITH DRIER NORTHEAST FLOW. WE SHOULD SEE A DECREASING
AREAL COVERAGE OF POPS AS THE DRIER AIR INFILTRATES THE REGION AND
THE AND THE TROUGH CONTINUES TO DAMPEN OUT. SPOTTY 20 PERCENT POPS
LOOK FAIR WITH A MORE TYPICAL SEA BREEZE DISTRIBUTION ANTICIPATED.
GRADIENT SLIGHTLY STRONGER TODAY WITH A STRONGER THERMAL LOW.
WINDS PICK UP MOSTLY LATER IN THE AFTERNOON AS THE SEA BREEZE
MOVES INLAND. TEMPERATURES REMAIN ABOVE NORMAL BUT JUST SLIGHTLY
DOWN A DEGREE OR TWO IN THE EAST AS THE SEA BREEZE COMES THROUGH A
BIT EARLIER.
TONIGHT...WARM AND MUGGY AND POSSIBLE A DEGREE WARM IF WINDS STAY UP
PASS MIDNIGHT.
SATURDAY...THE SHEAR LINE IS PRETTY MUCH LOST IN THE STRONGER
NORTHEAST FLOW AROUND THE RIDGE. MEAN RH LOWERS AND 850MB
TEMPERATURES RISE KEEPING RAIN CHANCES BELOW 10 PERCENT. EXPECT
AMBIENT TEMPERATURES TO PEAK ANOTHER DEGREE OR SO WITH LESS CLOUDS
AND LOWER RH. AFTERNOON BREEZES TO MAKE THE HEAT A BIT MORE
TOLERABLE.
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...H5 RIDGE CONTINUES
TO DOMINATE THE LOCAL WEATHER INTO THE MIDDLE OF NEXT
WEEK...KEEPING TEMPERATURES ABOVE NORMAL. THICKNESS VALUES REMAIN
STABLE AND ATMOSPHERIC MOISTURE REMAIN WELL BELOW NORMAL THROUGH
MIDWEEK...WHICH WILL KEEP A CONSISTENT TEMPERATURE REGIME. HIGHS
WILL BE IN THE MID TO UPPER 90S ALONG THE COAST AND 100 TO 105 FOR
THE WESTERN AREAS. HEAT INDEX VALUES WILL REACH 105 TO 110
AREAWIDE EACH AFTERNOON. PW VALUES REMAIN AT OR BELOW 1.5 INCHES
INTO NEXT WEEK...WITH NO RAIN CHANCES AND EVEN MINIMAL CLOUD
COVER. FAR EXTENDED MODELS ARE BEGINNING TO INDICATE THE THE RIDGE
WILL FINALLY DISPLACE SOUTHWARD AS THE EASTERN TROUGH MAKES AN
UNUSUALLY FAR SOUTHWARD DRIVE. AN ACCOMPANYING COLD FRONT MAY
DRIVE INTO TEXAS AGAIN...WITH A POSSIBLE RETURN OF RAIN CHANCES
FOR THE FIRST WEEKEND IN AUGUST.
MARINE...
TODAY THROUGH SATURDAY...PRESSURE GRADIENT TO SLOWLY STRENGTHEN
LATER TODAY INTO SATURDAY. INTERACTION BETWEEN THE SURFACE RIDGE
OVER THE GULF AND THERMAL LOW PRESSURE INLAND TO PROVIDE THE
SLIGHTLY STRONGER WINDS INTO SATURDAY. WINDS STILL REMAIN LOW
ENOUGH WITH NO MENTION OF EXERCISE CAUTION OR ANY ADVISORIES.
STILL A FEW SHOWERS OVER THE OFFSHORE COASTAL WATERS THIS MORNING
BECOMING EVEN MORE ISOLATED THIS AFTERNOON AND TONIGHT.
SATURDAY NIGHT THROUGH MONDAY...MODEST SOUTHEAST WINDS CONTINUE
FOR THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK AS THE
GULF RIDGE REMAINS FIRM AND THE HEAT LOW FLUCTUATES ACROSS WEST
TEXAS. ADVISORIES ARE NOT EXPECTED...BUT CAUTION MAY BE ADVISED
FOR THE LAGUNA SUNDAY AND MONDAY. LONG FETCH ACROSS THE GULF
BEGINS TO BUILD SEAS TO 3 TO 4 FEET EARLY NEXT WEEK.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
SHORT TERM FORECASTER... BUTTS
LONG TERM FORECASTER... TOMASELLI
PSU/GRAPHICAST... MARTINEZ
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1123 AM CDT FRI JUL 25 2014
.DISCUSSION...
QUIET WEATHER CONDITIONS ACROSS THE FORECAST AREA LATE THIS
MORNING...WITH HARDLY A CLOUD IN THE SKY. WATER VAPOR
IMAGERY...AND SUBJECTIVE ANALYSES CONTINUE TO INDICATE AN UPPER-
LEVEL SHEAR AXIS EXTENDING FROM THE NORTHERN GULF COAST INTO OUR
AREA. ALL INDICATIONS SUGGEST THAT BOUNDARY LAYER MOISTURE SHOULD
REMAIN SUFFICIENT TO ALLOW SOME ISOLATED CONVECTION TO DEVELOP
THIS AFTERNOON.
CONVECTION COULD DEVELOP NEAR THE IH-69E/US-77 CORRIDOR BETWEEN
NOON AND 2 PM AS THE SEABREEZE STARTS TO MOVE INLAND. HOWEVER...WITH
THE DEEPEST MOISTURE EXPECTED TO REMAIN AROUND THE IH-69C/US-281
CORRIDOR...THE GREATEST COVERAGE IS EXPECTED TO BE IN THIS REGION
THIS AFTERNOON AS SEABREEZE MOVES WESTWARD. THIS TREND IS
GENERALLY SUPPORTED BY RECENT HRRR MODEL RUNS. ALL THAT
SAID...PRECIPITATION PROBABILITIES AND TIMING HAVE BEEN ADJUSTED SLIGHTLY.
OTHERWISE...THE ONGOING FORECAST APPEARS TO BE IN DECENT SHAPE
WITH ONLY MINOR ADJUSTMENTS MADE HERE AND THERE TO ACCOUNT FOR
TRENDS IN THE OBSERVATIONAL DATA. ANY CHANGES TO FORECAST HIGH OR
LOW TEMPERATURES ARE PROVIDED BELOW FOR YOUR PERUSAL.
ISC GRIDS HAVE BEEN SENT AND SHOULD BE POSTED TO THE INTERNET.
UPDATED TEXT FORECAST PRODUCTS WILL BE ISSUED SHORTLY. /53/
&&
.PREV DISCUSSION... /ISSUED 629 AM CDT FRI JUL 25 2014/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...VFR CONDITIONS PREVAIL TODAY INTO TONIGHT WITH HIGH
PRESSURE CENTERED OVER NORTHWEST TEXAS. MID TO UPPER LEVEL
NORTHEAST FLOW WITH DRIER AIR TO LIMIT CLOUD COVER TO FEW-SCT. A
WEAKENING UPPER LOW PRESSURE TROUGH REMAINS CLOSE ENOUGH FOR
ISOLATED SHOWERS OR EVEN A THUNDERSTORM TO DEVELOP LATER THIS
AFTERNOON. LITTLE TO NO IMPACT ANTICIPATED AT THE 3 TERMINALS
SITE. LIGHT SOUTHEAST FLOW BECOMING MODERATE AS THE SEA BREEZE
MOVES EAST TO WEST BETWEEN 19-23Z
PREV DISCUSSION... /ISSUED 406 AM CDT FRI JUL 25 2014/
SHORT TERM /TODAY THROUGH SATURDAY/...WEAKENING 250MB SHEAR LINE
LIES ALONG THE TEXAS COAST WITH THE BASE OF THE TROUGH NOTED OVER
OUR WESTERN ZONES THIS MORNING. CENTER OF HOT RIDGE OVER THE TEXAS
PANHANDLE WITH DRIER NORTHEAST FLOW. WE SHOULD SEE A DECREASING
AREAL COVERAGE OF POPS AS THE DRIER AIR INFILTRATES THE REGION AND
THE AND THE TROUGH CONTINUES TO DAMPEN OUT. SPOTTY 20 PERCENT POPS
LOOK FAIR WITH A MORE TYPICAL SEA BREEZE DISTRIBUTION ANTICIPATED.
GRADIENT SLIGHTLY STRONGER TODAY WITH A STRONGER THERMAL LOW.
WINDS PICK UP MOSTLY LATER IN THE AFTERNOON AS THE SEA BREEZE
MOVES INLAND. TEMPERATURES REMAIN ABOVE NORMAL BUT JUST SLIGHTLY
DOWN A DEGREE OR TWO IN THE EAST AS THE SEA BREEZE COMES THROUGH A
BIT EARLIER.
TONIGHT...WARM AND MUGGY AND POSSIBLE A DEGREE WARM IF WINDS STAY UP
PASS MIDNIGHT.
SATURDAY...THE SHEAR LINE IS PRETTY MUCH LOST IN THE STRONGER
NORTHEAST FLOW AROUND THE RIDGE. MEAN RH LOWERS AND 850MB
TEMPERATURES RISE KEEPING RAIN CHANCES BELOW 10 PERCENT. EXPECT
AMBIENT TEMPERATURES TO PEAK ANOTHER DEGREE OR SO WITH LESS CLOUDS
AND LOWER RH. AFTERNOON BREEZES TO MAKE THE HEAT A BIT MORE
TOLERABLE.
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...H5 RIDGE CONTINUES
TO DOMINATE THE LOCAL WEATHER INTO THE MIDDLE OF NEXT
WEEK...KEEPING TEMPERATURES ABOVE NORMAL. THICKNESS VALUES REMAIN
STABLE AND ATMOSPHERIC MOISTURE REMAIN WELL BELOW NORMAL THROUGH
MIDWEEK...WHICH WILL KEEP A CONSISTENT TEMPERATURE REGIME. HIGHS
WILL BE IN THE MID TO UPPER 90S ALONG THE COAST AND 100 TO 105 FOR
THE WESTERN AREAS. HEAT INDEX VALUES WILL REACH 105 TO 110
AREAWIDE EACH AFTERNOON. PW VALUES REMAIN AT OR BELOW 1.5 INCHES
INTO NEXT WEEK...WITH NO RAIN CHANCES AND EVEN MINIMAL CLOUD
COVER. FAR EXTENDED MODELS ARE BEGINNING TO INDICATE THE THE RIDGE
WILL FINALLY DISPLACE SOUTHWARD AS THE EASTERN TROUGH MAKES AN
UNUSUALLY FAR SOUTHWARD DRIVE. AN ACCOMPANYING COLD FRONT MAY
DRIVE INTO TEXAS AGAIN...WITH A POSSIBLE RETURN OF RAIN CHANCES
FOR THE FIRST WEEKEND IN AUGUST.
MARINE...
TODAY THROUGH SATURDAY...PRESSURE GRADIENT TO SLOWLY STRENGTHEN
LATER TODAY INTO SATURDAY. INTERACTION BETWEEN THE SURFACE RIDGE
OVER THE GULF AND THERMAL LOW PRESSURE INLAND TO PROVIDE THE
SLIGHTLY STRONGER WINDS INTO SATURDAY. WINDS STILL REMAIN LOW
ENOUGH WITH NO MENTION OF EXERCISE CAUTION OR ANY ADVISORIES.
STILL A FEW SHOWERS OVER THE OFFSHORE COASTAL WATERS THIS MORNING
BECOMING EVEN MORE ISOLATED THIS AFTERNOON AND TONIGHT.
SATURDAY NIGHT THROUGH MONDAY...MODEST SOUTHEAST WINDS CONTINUE
FOR THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK AS THE
GULF RIDGE REMAINS FIRM AND THE HEAT LOW FLUCTUATES ACROSS WEST
TEXAS. ADVISORIES ARE NOT EXPECTED...BUT CAUTION MAY BE ADVISED
FOR THE LAGUNA SUNDAY AND MONDAY. LONG FETCH ACROSS THE GULF
BEGINS TO BUILD SEAS TO 3 TO 4 FEET EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 95 80 95 80 / 10 10 10 10
BROWNSVILLE 96 78 97 79 / 20 10 10 10
HARLINGEN 99 76 100 79 / 20 10 10 10
MCALLEN 100 78 100 79 / 20 10 10 10
RIO GRANDE CITY 102 79 102 78 / 20 10 10 10
SOUTH PADRE ISLAND 91 80 91 81 / 10 20 20 10
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
SHORT TERM FORECASTER... BUTTS
LONG TERM FORECASTER... TOMASELLI
PSU/GRAPHICASTS... CAMPBELL
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 227 PM CDT FRI JUL 25 2014
LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE
LOCATED OVER THE EASTERN U.S. AND A TROUGH OF LOW PRESSURE OVER THE
NORTHERN PLAINS. BETWEEN THESE FEATURES...WARM AIR AND MOISTURE
ADVECTION IS ONGOING IN THE LOW AND MID-LEVELS. THIS WEAK FORCING
COMBINED WITH ONE SHORTWAVE OVER EASTERN WISCONSIN AND ANOTHER OVER
NORTH-CENTRAL WISCONSIN HAS CONTRIBUTED TO SPOTTY SHOWER ACTIVITY
OVER THE COURSE OF THE DAY. SHOWERS ARE MAINLY CONFINED TO N-C
WISCONSIN CURRENTLY AS SHOWERS WITH THE EASTERN WISCONSIN SHORTWAVE
HAVE PUSHED SOUTH OF THE AREA. LOOKING UPSTREAM...SCT TO BKN STRATO
CU EXISTS ALL THE WAY INTO THE EASTERN DAKOTAS WHERE DEWPOINTS ARE
PUSHING INTO THE MIDDLE AND UPPER 60S. AS THIS MOISTURE RICH AIR
SPREADS EAST...SMALL SHOWER CHANCES AND CLOUDS ARE THE MAIN FORECAST
CONCERNS.
TONIGHT...AS ONE SHORTWAVE EXITS SOUTHEAST WISCONSIN EARLY THIS
EVENING...ANOTHER WAVE WILL BE DIVING SOUTHEAST OVER NORTHEAST
WISCONSIN. UNTIL THIS WAVE EXITS...WILL LEAVE AT LEAST AN ISOLATED
MENTION OF SHOWERS OVER N-C AND NORTHEAST WISCONSIN UNTIL LATE IN
THE EVENING. THEREAFTER...THOUGH WEAK THETAE ADVECTION WILL STILL
BE OCCURRING IN THE LOW LEVELS...MODELS SHOW MID-LEVEL MOISTURE
DEPARTING BEHIND THE SHORTWAVE AND A DECENT CAP DEVELOPING AROUND
700MB. SO THINK SMALL PRECIP CHANCES WILL END BY LATE IN THE
EVENING...AND THEN GO DRY THE REST OF THE NIGHT. SURFACE DEWPOINTS
WILL BE INCREASING HOWEVER...AND WITH NOCTURNAL COOLING...LOW
STRATUS SHOULD REMAIN RELATIVELY WIDESPREAD AND LOWER THROUGH THE
NIGHT. THIS WILL MAKE FOR A WARMER AND MUGGIER NIGHT THAN THE PAST
FEW WITH LOWS IN THE LOW TO MID 60S.
SATURDAY...AREAS OF STRATUS WILL LINGER INTO THE MORNING HOURS.
WITH DAYTIME HEATING...MIXING SHOULD BE ABLE TO TAP INTO THE DRY AIR
ABOVE THE INVERSION AND HELP TO DIMINISH THE CLOUDS FROM WEST TO
EAST OVER THE COURSE OF THE DAY. LOW LEVEL TEMPS ARE PROJECTED TO
BE QUIET TOASTY TOMORROW AND HAVE RAISED HIGHS A DEGREE OR TWO IN
MOST AREAS. HIGHS IN THE LOW TO MID 80S.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 227 PM CDT FRI JUL 25 2014
PCPN TRENDS FOR THE LATTER HALF OF THE WEEKEND...AND THE
POTENTIAL FOR SEVERE TSTMS ON SUNDAY AFTERNOON...WILL BE THE
MAIN FCST CHALLENGES.
MODELS ARE STILL TRYING TO FIND CONCENSUS ON THE TIMING OF THE
STRONG UPPER LEVEL TROF AND CANADIAN COLD FRONT ON SATURDAY NIGHT
AND SUNDAY. SLOWER IS USUALLY THE WAY TO GO WHEN DEALING WITH AN
UPPER LOW...SO HAVE LEANED TOWARD THE SLOWER ECMWF FOR THIS
SYSTEM. THIS WOULD SUGGEST A CHANCE OF TSTMS OVER THE NORTHWEST
THIRD OF GRB CWA AFTER MIDNIGHT SATURDAY NIGHT...THEN LIKELY POPS
SPREADING SE ACROSS THE FORECAST AREA ON SUNDAY. IF THE ECMWF
VERIFIES...ITS SLOWER MOVMT WOULD ALLOW FOR A LITTLE MORE HEATING
AND INSTABILITY IN ADVANCE OF THE SYSTEM...AND POTENTIALLY A
LITTLE GREATER THREAT OF SVR TSTMS OVER THE SE HALF OF THE
FORECAST AREA. MODIFIED FCST SOUNDINGS SUGGEST CAPE AROUND
1000-1500 J/KG...LI`S -3 TO -5...AND FAVORABLE WET BULB ZERO HGTS
OF 9.5-10K FT. DEEP LAYER SHEAR IS EXPECTED TO BE 25 TO 35 KTS
IN ADVANCE OF THE COLD FRONT AROUND MIDDAY...BUT SHOULD QUICKLY
WEAKEN AS THE UPPER TROF ARRIVES LATE IN THE DAY. ALTHOUGH A
SIGNIFICANT SVR WX EVENT IS NOT LIKELY DUE TO WIDESPREAD
CLOUDS/SHOWERS...WE CANNOT RULE OUT A FEW SVR TSTMS WITH LARGE
HAIL OVER PARTS OF NE/C/EC WI DURING THE AFTERNOON...SO WILL
CONTINUE TO MENTION THIS THREAT IN THE HWO.
THE EXTENDED FCST FOR THE UPCOMING WORK WEEK IS EXPECTED TO BE
AT OR A LITTLE COOLER THAN COOLER THAN NORMAL...WITH SCATTERED
SHOWERS AND TSTMS...MAINLY DURING THE AFTERNOONS AND EARLY
EVENINGS. A STRONG UPPER LEVEL RIDGE WILL BE SITUATED OVER THE
ROCKIES...WITH A LARGE UPPER TROF OVER THE EASTERN U.S. AND
EASTERN CANADA. ALTHOUGH S/W TROFS IN THE NW FLOW MAY GENERATE
SOME PCPN AT TIMES...IT APPEARS THAT MOST OF THE RAIN WILL BE
DIURNALLY-DRIVEN DUE TO DAYTIME HEATING/INSTABILITY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1232 PM CDT FRI JUL 25 2014
INCREASING LOW LEVEL MOISTURE WILL BE WORKING NORTHEAST
ACROSS THE STATE THROUGH THE PERIOD. THOUGH THE CHANCES OF SHOWERS
WILL DIMINISH LATER THIS AFTERNOON WHEN A WEAK DISTURBANCE
EXITS...MVFR TO IFR CIGS/VSBYS ARE LIKELY TO DEVELOP GENERALLY AFTER
MIDNIGHT TONIGHT. RELATIVELY QUICK IMPROVEMENT TO THE CIGS/VSBYS
SHOULD OCCUR TOMORROW MORNING WITH DAYTIME HEATING AND MIXING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1247 PM CDT FRI JUL 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 303 AM CDT FRI JUL 25 2014
LATEST MOSAIC RADAR SHOWING A LINE OF SHOWERS AND THUNDERSTORMS
DEVELOPING FROM WEST CENTRAL MINNESOTA INTO CENTRAL IOWA EARLY
THIS MORNING. THE SHOWERS AND THUNDERSTORMS IS ON THE NOSE OF THE
LOW LEVEL JET/MOISTURE TRANSPORT AND CONVERGENCE IN THE 925-850MB
LAYER PER THE LATEST 25.03 RAP AND 25.00Z GFS/NAM.
THE 25.00Z NAM/GFS AND THE 25.03Z RAP INDICATE THE NOSE OF LOW LEVEL
JET/MOISTURE TRANSPORT AND CONVERGENCE WILL BE POINTED DIRECTLY INTO
MAINLY THE SOUTHERN FORECAST AREA THROUGH 18Z TODAY. HOWEVER...THE
MODELS SHOW THE CORFIDI VECTORS/UPWIND PROPAGATION VECTORS TO MOVE
THE SHOWERS AND THUNDERSTORMS SOUTH TO SOUTHEAST AND IMPACT MAINLY
THE SOUTHERN FORECAST AREA TODAY. THIS IS EVIDENT WITH MOVEMENT OF
THE THUNDERSTORMS EARLY THIS MORNING PER THE LATEST MOSAIC RADAR.
AT THIS TIME...SEVERE WEATHER THREAT LOOKS TO BE MINIMAL WITH THE
THUNDERSTORMS...AS THE LATEST 25.00Z NAM AND 25.03Z RAP SHOW 0-6KM
MOST UNSTABLE CAPE LESS THAN 1000 J/KG AND THE BETTER ELEVATED
INSTABILITY TO BE WEST OF THE DEVELOPING THUNDERSTORM
ACTIVITY/NOSE OF THE LOW LEVEL JET/MOISTURE CONVERGENCE. THE
MODELS SHOW PRECIPITABLE WATERS APPROACHING 1.5 TO 2 INCHES LATE
THIS MORNING. SOME OF THE THUNDERSTORMS COULD PRODUCE LOCAL HEAVY
RAINFALL.
THE LOW LEVEL JET/MOISTURE CONVERGENCE WEAKENS AND MOVES EAST OF
THE FORECAST AREA THIS AFTERNOON AND EVENING AND WILL ALLOW FOR
SKIES AND PRECIPITATION CHANCES TO DIMINISH WEST TO EAST ACROSS
THE FORECAST AREA.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 303 AM CDT FRI JUL 25 2014
NEXT CONCERN IS CLOSED UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN
AND ALBERTA SLOWLY MEANDERS OVER THE UPPER GREAT LAKES REGION
SATURDAY NIGHT INTO SUNDAY. THE 25.00Z GFS/NAM SHOW MUCH STRONGER
AND DEEPER QG FORCING IN ASSOCIATION WITH THE UPPER LEVEL LOW. BEST
FORCING INCREASES OVER THE NORTHERN PORTIONS OF FORECAST AREA LATE
SATURDAY NIGHT INTO SUNDAY...HENCE THE BETTER PRECIPITATION CHANCES.
THE NAM/GFS BUFKIT SOUNDINGS INDICATE WEAK ELEVATED CAPE MAINLY
ABOVE 800MB BY 18Z SUNDAY AND 0-6KM MOST UNSTABLE CAPE OF 500-1000
J/KG EAST OF THE MISSISSIPPI RIVER. WILL CONTINUE TO MENTION
ISOLATED THUNDERSTORMS SATURDAY NIGHT INTO SUNDAY.
SUNDAY NIGHT THROUGH THURSDAY...NORTHERLY FLOW DEVELOPS OVER THE
UPPER GREAT LAKES REGION PER LATEST 25.00Z GFS/ECMWF/GEM. MAIN
CONCERN IS TIMING OF THE WEAK SHORTWAVE TROUGHS EMBEDDED IN THE
NORTHERLY FLOW ALOFT AND PRODUCE SMALL PRECIPITATION CHANCES ACROSS
PARTS OF THE FORECAST AREA TUESDAY...WEDNESDAY NIGHT INTO
THURSDAY. TEMPERATURES MONDAY THROUGH THURSDAY WILL CONTINUE TO BE
UNSEASONABLY COOL ACROSS FORECAST AREA...AS THE 25.00Z GEFS
INDICATE 850MB TEMPERATURE ANOMALIES IN THE MINUS 0.5 TO MINUS 1.5
DEGREES CELSIUS RANGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1247 PM CDT FRI JUL 25 2014
BROKEN MVFR CEILINGS WILL SLOWLY LIFT AND SCATTER OUT THIS
AFTERNOON...INITIALLY AT KRST AND LIKELY TOWARD LATE AFTERNOON AT
KLSE. ATTENTION THEN TURNS TO FOG/STRATUS OVERNIGHT. SEVERAL
POSITIVES GOING FOR AN IFR PERIOD OVERNIGHT INCLUDE HIGHER
SURFACE DEWPOINTS...RECENT RAINFALL...AND EXPECTED CLEARING SKIES
LATE THIS EVENING. SURFACE WINDS LIKELY SHOULD DROP TO LESS THAN
5 KTS AFTER 06Z...THROUGH A DEPTH OF A FEW HUNDRED FEET. SOUNDINGS
SHOW LESS THAN 10 KTS THROUGH ABOUT 1000 FEET...BUT THE TREND IN
RECENT NAM/GFS/RAP RUNS SHOWS THIS COULD END UP HIGHER. IN THE
END...IF SKIES DO INDEED CLEAR OUT PARTIALLY...AND AHEAD OF HIGH
LEVEL CLOUDS BY MORNING...THEN IFR FOG/STRATUS SEEMS LIKELY AND
COULD GO DOWN TO 1/4SM FOR A LONGER PERIOD. FOR NOW...BROUGHT
VISIBILITIES DOWN TO 1SM AND INCLUDED A SCATTERED IFR CEILING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM....DTJ
AVIATION.....ZT