Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 05/12/12
AREA FORECAST DISCUSSION
NWS DES MOINES IA
650 PM CDT FRI MAY 11 2012
.SHORT TERM /TONIGHT/...
THE COLD FRONT WAS ALONG A NEWTON TO LAMONI LINE AT 20Z THIS
AFTERNOON. VISIBLE SATELLITE IMAGERY WAS SHOWING A FEW CU DEVELOPING
NEAR THE BOUNDARY. SURFACE DEW POINTS ALONG AND AHEAD OF THE FRONT
WERE IN THE MID TO UPPER 50S. THE 19Z SPC THERMODYNAMICS FIELDS
SUGGEST MODEST INSTABILITY WITH VERY WEEK MOISTURE CONVERGENCE ALONG
THE FRONT. THROUGH THE EARLY EVENING...EXPECT THE FRONT TO SLOWLY
MOVE SOUTHEAST REACHING DAVIS COUNTY BY 7 PM. 12Z GFS/NAM AND THE
LATEST HRRR DEVELOP SHOWERS OR THUNDERSTORMS NEAR THE FRONT THIS
EVENING. THERE WILL BE ENOUGH INSTABILITY AND LIFT TO KEEP A SMALL
CONDITIONAL CHANCE OF SHOWERS AND THUNDERSTORMS IN THE FORECAST.
WEAK MID LEVEL FORCING AHEAD OF POSITIVELY TILTED 700 MB TROUGH AND
MID-LEVEL MOISTURE MAY BE ADEQUATE TO PRODUCE SCATTERED SHOWERS OVER
SOUTH CENTRAL IOWA TONIGHT ALONG WITH CLOUDINESS. PREVIOUS
TEMPERATURE FORECAST LOOKED GOOD REQUIRING ONLY MINOR ADJUSTMENTS.
.LONG TERM /SATURDAY THROUGH FRIDAY/...
RATHER QUIET PERIOD TO CONTINUE INTO THE WEEKEND AND NEXT WEEK. A
FEW ITEMS TO MENTION INCLUDING COLD FRONTAL BOUNDARY HANGING UP OVER
CENTRAL TO NORTHERN MO ON SATURDAY MAY HAVE ENOUGH ISENTROPIC LIFT
TO KEEP A FEW SHOWERS OVER FAR SOUTHERN IOWA SATURDAY AND SATURDAY
EVENING. CLOUDS WILL ALSO LINGER OVER THE SOUTH ON SATURDAY BUT
SHOULD EXIT THE REGION BY SATURDAY EVENING LEAVING SUNDAY MAINLY
SUNNY AND QUIET. MODEST FLOW REMAINS ACROSS THE NORTHERN TIER STATES
WITH A FEW WAVES TRAVELING ALONG THE US CAN BORDER. A WEAK COOL
FRONT HAS BEEN ADVERTISED TO CROSS THE REGION BY TUESDAY EVENING OR
WEDNESDAY MORNING. THIS WILL ALLOW FOR SLIGHTLY COOLER AIR TO DROP
INTO THE REGION FOR A DAY PRIOR TO THE FRONT LIFTING BACK NORTH BY
WEDNESDAY NIGHT AND THURSDAY. CLIMATOLOGY FAVORS SOME THUNDER
ACTIVITY AS THE FRONT LIFTS NORTH...BUT MODELS REMAIN RATHER DRY AS
FLOW OVER THE SOUTH HAS BEEN SHUT DOWN WITH WEAK LOW PRESSURE AND
NORTHWEST FLOW HUGGING THE GULF COAST. THUS...AM RELUCTANT TO GET
TOO EXCITED ABOUT POP IN THE REMAINDER OF THE EXTENDED PERIOD UNTIL
A STRONGER WAVE DROPS INTO THE WEST. IT APPEARS THAT THE NEXT
OPPORTUNITY FOR THAT WILL COME 24 TO 48 HOURS FOLLOWING THE CURRENT
EXTENDED FORECAST. FORECAST HIGHS WILL WARM NICELY BY THE END OF THE
EXTENDED PERIOD. WITH SW FLOW IN PLACE AND GOOD MIXING COMBINED WITH
H850 TEMPS OF 17-19C...WILL LIKELY SEE HIGHS IN THE MID TO UPPER 80S
IF THE TREND HOLDS. COORD WITH SURROUNDING OFFICES WITH LOWER 80S IN
MIND AND WILL WAIT FOR A FEW MORE CONFIRMATION RUNS PRIOR TO RAISING
TEMPS HIGHER...BUT BOTH H500 PATTERN WITH RIDGE BUILDING OVER THE
LOWER MS RIVER VALLEY AND INCREASING H850 TEMPS SUPPORT VERY WARM
AND INCREASINGLY HUMID AIRMASS NORTH INTO THE REGION. EURO THICKNESS
BY 00Z SAT 5/19 BACK TO 570-573DM WHICH IS RATHER SUMMER LIKE.
&&
.AVIATION...12/00Z
FIRST CONCERN WILL BE CONVECTIVE TRENDS ALONG COLD FRONT JUST
APPROACHING KOTM. FEEL THUNDER POTENTIAL HAS ENDED THERE FOR THE
TIME BEING SO HAVE PULLED ANY MENTION BEYOND VCSH. COLD FRONT WILL
EXIT FORECAST AREA THIS EVENING WITH ATTENTION TURNING TOWARD
TRAILING PARENT SW-NE UPPER LEVEL SYSTEM ACROSS THE SIOUXLAND
AREA...AND OK UPPER LOW. EITHER OF THESE COULD PRODUCE SCATTERED
SHOWERS SAT...BUT WILL NOT ADD ANY MENTION UNTIL TRENDS BECOME MORE
CLEAR RATHER THAN EXTENDED PERIOD OF VCSH WORDING. EVEN IF PRECIP
DOES DEVELOP...EXPECT CONDITIONS TO REMAIN VFR.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...JOHNSON
LONG TERM...REV
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
631 PM CDT FRI MAY 11 2012
.AVIATION...
A COLD FRONT IS PASSING SOUTHEAST THROUGH EASTERN IA AND NW IL
THIS EVENING. ALONG AND AHEAD OF THE FRONT...THERE WILL BE
POTENTIAL FOR SHOWERS AND PERHAPS AN ISOLATED EVENING
THUNDERSTORM MAINLY AT CID AND DBQ TERMINALS. FOLLOWING THE
FRONTAL PASSAGE BEYOND 06Z...BUT WITH LIMITED COVERAGE
EXPECTED...WILL CONTINUE PROB30 GROUPS AND VC WORDING FOR SHOWERS
LATE TONIGHT INTO SATURDAY MORNING AND NOT INCLUDE ANY MENTION OF
THUNDER...MAINLY AT MLI AND BRL TERMINALS. WINDS AFTER THE FRONT
PASSES WILL VEER TO THE NORTHWEST AND THEN NORTH TO NORTHEAST
SATURDAY MORNING. FLIGHT RULES ARE TO REMAIN VFR THROUGHOUT...WITH
A BRIEF PERIOD OF MVFR CIGS POSSIBLE WITH THE STRONGEST PRECIPITATION
LATE TONIGHT AND SATURDAY MORNING. NICHOLS
&&
.PREV DISCUSSION... /ISSUED 312 PM CDT FRI MAY 11 2012/
SYNOPSIS...
MOISTURE STARVED SURFACE COLD FRONT CONTINUES CRAWL SLOWLY ACROSS IA
THIS AFTERNOON...REACHING FROM WEST CENTRAL WI...TROUGH MASON CITY
TO WEST OF DES MOINES...INTO FAR NW MO AT 19Z. VISIBLE SATELLITE
SHOWED MOSTLY CLEAR SKIES OVER THE FORECAST AREA WITH SIGNIFICANT
CLOUD COVER NEAR THE BOUNDARY LIMITED TO MN AND WI...WHILE POST
FRONTAL CLOUDS ASSOCIATED WITH HIGHER MOISTURE AND MID AND UPPER
LEVEL FORCING WERE WELL TO THE NW FROM NW NEB THROUGH SE SD INTO MN.
AREA RADAR MOSAIC INDICATED A BAND OF SHOWERS WELL BEHIND THE FRONT
FROM W CENTRAL MN INTO N CENTRAL NEB. ISOLATED HIGH BASED SHOWERS
WERE BEGINNING TO POP UP IN W CENTRAL AND NW IA OVER THE PAST HOUR.
TEMPERATURES WERE INTO THE UPPER 70S TO LOWER 80S OVER THE FORECAST
AREA...WHILE UPPER 60S TO LOWER 70S WERE FOUND WEST OF THE BOUNDARY
ACROSS WESTERN IA AND SW MN.
SHORT TERM...TONIGHT AND SATURDAY...
PRIMARY CHALLENGE IS RAIN CHANCES AS THE COLD FRONT PUSHES THROUGH
THE AREA TONIGHT INTO SATURDAY. WITH GULF MOISTURE RATHER MEAGER AND
LIMITED BY A LOW MOVING ACROSS TX TODAY...SURFACE DEWPOINTS HAVE
ONLY REACHED A NARROW AXIS OF MID 50S AHEAD OF THE FRONT...AND 850
MB ANALYSIS FROM THIS MORNING WOULD SUGGEST BULK OF GULF MOISTURE TO
REMAIN CUTOFF IN THE SOUTHERN PLAINS. CLOSE INSPECTION OF THE LATEST
VISIBLE SATELLITE SHOWS THE FIRST CU OF THE DAY STARTING TO POP
ALONG THE BOUNDARY NEAR DSM...AND WILL WATCH THIS DEVELOPMENT ALONG
AND AHEAD OF THE FRONT FOR POSSIBLE SHOWERS AND THUNDERSTORMS THIS
AFTERNOON AS MUCAPES RISE TO VALUES WELL BELOW 1000 J/KG.
OTHERWISE...IT LOOKS LIKE THE BETTER FORCING FOR SHOWERS TONIGHT
WILL MORE CLOSELY TIED TO THE WEAK FORCING AND MOISTURE AROUND 700
MB ASSOCIATED WITH THE CURRENT AXIS OF POST FRONTAL SHOWERS. THIS
FEATURE FOLLOWS THE FRONT INTO THE FORECAST AREA LATER THIS EVENING
AND OVERNIGHT AND WILL KEEP CHANCE POPS IN PLACE. WILL KEEP AN
MENTION OF ISOLATED THUNDERSTORMS FOR THE EVENING FOR THE POSSIBLE
DEVELOPMENT OF CONVECTION ALONG THE ADVANCING BOUNDARY...WHICH IS
STILL SUGGESTED AS POSSIBILITY BY THE HRRR MODEL. OTHERWISE...
INCREASING CLOUD COVER WILL OFFSET THE LOW LEVEL COLD AIR ADVECTION
BEHIND THE WEAKENING COLD FRONT AND LIMIT LOWS TO AROUND 50 NORTH TO
THE MID 50S SOUTH.
SATURDAY...THE FRONT CONTINUES TO WEAKEN AND SLOW AS IT DROPS TOWARD
THE UPPER LEVEL SYSTEM MOVING THROUGH THE MID MS VALLEY. WEAK MID
LEVEL FORCING AND MOISTURE IS SHOWN POOLING NORTH OF THE BOUNDARY
THROUGH AT LEAST THE MORNING HOURS TO JUSTIFY CHANCE POPS FOR LIGHT
RAIN SHOWERS. THIS THEN SHIFTS TO THE FAR SOUTH IN THE AFTERNOON AS
SURFACE HIGH PRESSURE BUILDS OVER THE NORTHERN PLAINS INTO THE UPPER
MS VALLEY...INCREASING THE LOW LEVEL FLOW OF DRY AIR INTO THE AREA.
LINGERING MID AND HIGH LEVEL MOISTURE AND WEAK FORCING EMBEDDED IN
THE MID LEVEL CYCLONIC FLOW TO THE NORTH WILL LIKELY KEEP SKIES
MOSTLY CLOUDY AND WILL LIMIT HIGHS TO THE 60S OVER MOST OF THE
AREA. SHEETS
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
MAIN FOCUS THIS FORECAST TIME RANGE IS ON PRECIPITATION CHANCES
SATURDAY NIGHT AND AGAIN WEDNESDAY THROUGH FRIDAY.
SATURDAY NIGHT AND SUNDAY THE COLD FRONT CONTINUES TO SAG SOUTH. THE
850MB BOUNDARY REMAINS IN THE AREA SATURDAY NIGHT AND A WEAK VORT
MAX WILL DROP SOUTH ACROSS THE AREA. THIS MAY PRODUCE SOME ELEVATED
SHOWERS SATURDAY NIGHT...MAINLY IN THE EVENING. MOISTURE IS A
LIMITING FACTOR SO HAVE KEPT PRECIPITATION CHANCES IN THE SLIGHT
CHANCE CATEGORY. TEMPERATURES TO BE MILD BOTH PERIODS WITH CLOUDS
TEMPERING THE COOLER AND DRIER AIR COMING IN FROM THE NORTH. MINS
SATURDAY NIGHT IN THE 40S AND LOW 50S. HIGHS SUNDAY TO BE IN THE
LOW 70S.
MONDAY AND TUESDAY A WEAK SURFACE RIDGE TO BUILD SOUTH ACROSS THE
AREA WITH WEAK WESTERLY RETURN FLOW SETTING UP FOR TUESDAY. THIS
WILL ALLOW TEMPERATURES TO RISE SO THAT ON TUESDAY WE WILL HAVE
HIGHS IN THE UPPER 70S AGAIN...POSSIBLY EVEN SOME MORE LOW 80S.
FORECAST HIGHS MAY NEED TO BE RAISED IF IT STILL APPEARS WE WILL BE
WORKING WITH VERY DRY AIR AND DEEP MIXING.
WEDNESDAY THROUGH FRIDAY THE SURFACE RIDGE SLIPS OFF TO THE
SOUTHEAST AND SOUTHWEST RETURN FLOW SETS IN IN EARNEST WITH A LONG
FETCH FROM TEXAS...AND BY FRIDAY IT APPEARS THAT THERE WILL BE
STREAM OF GULF MOISTURE HEADING OUR DIRECTION. A FAIRLY STRONG
UPPER LEVEL SYSTEM OVER CANADA WILL PUSH A COLD FRONT TOWARDS THE
AREA WEDNESDAY. THIS FRONT MAY DROP INTO THE AREA WEDNESDAY...
THOUGH THERE IS SOME MODEL DISAGREEMENT HERE...WITH SOME KEEPING IT
NORTH OF THE AREA. FOR NOW HAVE KEPT THE FORECAST DRY AS THERE IS
LITTLE MOISTURE AVAILABLE FOR THIS BOUNDARY TO WORK WITH. A SURFACE
LOW IS GENERATED OVER WESTERN KANSAS...AND BY THURSDAY AND FRIDAY
THE FRONT BECOMES A WARM FRONT AND PUSHES BACK NORTH...AND WILL BE
GENERALLY DRAPED FROM SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND
INTO WISCONSIN. UNLESS THIS CHANGES THIS IS LIKELY TO BE THE STORM
TRACK NEXT WEEK...AND WE WILL BE SITTING IN A VERY WARM AND
INCREASINGLY HUMID AIRMASS BOTH DAYS...WITH HIGHS INTO THE LOW 80S.
HAVE SOME VERY LOW END CHANCE POPS IN THE FORECAST...BUT UNLESS THE
FRONT SHIFTS CLOSER TO THE AREA AM ANTICIPATING WE WILL BE DRY.
LE
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
NICHOLS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
101 AM EDT THU MAY 10 2012
.Forecast Update...
Issued at 1041 PM EDT Wed May 9 2012
One more quick update now that the showers have ended. The gusty
north winds should settle down over the next 1-2 hours.
Issued at 911 PM EDT Wed May 9 2012
Another update to follow radar trends, with big PoPs over small
areas where rain is currently falling. Also spread the PoPs farther
to the west since the western end of the area of scattered showers
has been holding together fairly well. This resulted in introducing
ISO/SCT showers to the Louisville metro roughly northeast of a line
from Palmyra to Shively to Mount Washington.
Issued at 827 PM EDT Wed May 9 2012
Have upped PoPs to 100% where it is currently raining from northern
Washington County through all of Jefferson County Indiana, with a
buffer zone around that of likelies. Still expecting the showers to
fade away as the sun sets.
Issued at 650 PM EDT Wed May 9 2012
Scattered showers in central Indiana have been holding their own as
they push quickly to the southeast, and there has even been some new
development between Indy and Bloomington along with an increase in
lightning production. The showers are only a couple counties away
from the LMK CWFA at this point, so a decision needed to be made
regarding PoPs this evening (which were dry). After looking at KIND
radar and HRRR progs, have decided to go ahead and insert SCT/ISO
PoPs into the north, basically north of a line from Paoli to
Louisville to Lexington. The showers should fizzle as they reach
the Blue Grass around mid-evening, and we have the PoPs stopping at
02Z.
.Short Term (Tonight through Thursday night)...
Issued at 245 PM EDT May 9 2012
A weak upper disturbance is rotating southeast across the lower
Great Lakes region, sparking off not only widespread, high-based
strato-cu, but also showers and even a few storms across IL/IN/OH.
Most of this activity will stay to our north, however our
northeastern CWA could see some sprinkles perhaps by early evening.
By that time, clouds/precip will start to dissipate with the loss of
afternoon heating, so will keep just the sprinkle wording in the
grids. Best time frame/location will be between 5-10pm northeast of
a line from Louisville to Lexington. Until that timeframe, expect
gusty northwest winds and partly cloudy skies.
Once that trough swings through by roughly midnight, we`ll have
clearing skies thereafter as surface high pressure starts to slide
in from the west. Winds will become light and will help overnight
lows drop into the low-mid 40s north to around 50 south.
The center of the surface high will still be to our west Thursday,
so a steady northerly wind will be in place. Even a few gusts to
about 15 knots or so will be possible especially east of I-65
tomorrow with good mixing. Although skies will be sunny, a steady
northerly wind will keep temps around the same highs as today, maybe
even a tad cooler. Look for highs in the mid-upper 60s north and
east, to the low 70s over the southwest.
Thursday night should be the coolest night with the surface high
directly overhead. Winds will be calm, and with excellent
radiational cooling, lows will plummet into the low 40s most places.
Wouldn`t be surprised to see a few sheltered, Bluegrass locations
drop into the upper 30s.
.Long Term (Friday through Wednesday)...
Issued at 318 PM EDT May 9 2012
Friday Through Sunday Night...
The Ohio Valley will start off in northwesterly flow on Friday as a
large trough exits in the northeast US and weak mid-level low moves
into the southern Plains. High pressure will remain in control of
the weather with dry conditions Friday/Friday night. Short term
shot of upper ridging ahead of the approaching southern Plains wave
will keep the region dry on Saturday, but we`ll likely see a quick
increase in cloud cover throughout the day. Combination of
southerly return flow and isentropic ascent will likely lead to some
isolated showers/storms develop Saturday night especially across
southern KY. Better moisture and synoptic scale lift look much
better on Sunday which looks to be rather dreary with extensive
cloud cover and scattered to numerous showers/storms dotting the
region as the upper wave moves across the region. Clouds and
convection are likely to continue Sunday night as the upper wave
slowly moves east and a surface low and cold front push through the
region. Basically have done an incremental update here as the
previous forecast has this well handled. Given the increasing
forecast convergence here, have raised PoPs a little during the
Sun/Sun night period.
Highs Friday and Saturday will generally be in the mid-upper 70s but
cool into the lower 70s for Sunday. Overnight temps look to remain
rather mild with readings in the upper 40s to the lower 50s.
Monday through Wednesday...
This afternoons long term deterministic and ensemble guidance is in
general agreement with the upper level flow across the CONUS in this
time frame. By and large, the models suggest that a large ridge
will build across the western US early in the period which will
force a downstream trough to develop across the eastern US. A
decent mid-level wave looks to crash into the western US coast by
late in the period which will likely knock down that western ridge.
Considerable spread exists in the height fields across the east
during the period with regards to whether we`ll see a closed low
develop. The 09/00Z and 09/12Z GFS offer the one extreme with a
very pronounced cut off low developing over the east and then
meandering slowly to the east as the flow becomes a bit more zonal.
The 09/00Z and 09/12Z GFS ensembles are not as robust with the upper
low development and actually have a little less spread when compared
with the 09/00Z and 09/12Z OP Euro and its ensembles. Suffice to
say, forecast confidence is average at the beginning of the period
with confidence dropping in the day 6/7 (Tue/Wed) timeframe as the
uncertainty with possible closed low develop complicate the
forecast. With this issuance, have leaned closer the 12Z GFS
Ensemble and Euro solutions which gives decent continuity to the
previous forecast.
This period of the forecast will likely be a rather unsettled one
with the upper trough being situated over the eastern US. Variable
cloudiness is likely with chances of rain throughout the period. It
does seem likely that the best chances of precipitation would be in
the Monday/Tuesday time frame as the trough moves over us with
lesser chances on Wednesday as the GEFS/Euro solutions are slightly
more progressive. For now, will keep slight to low chance PoPs
going with a drier trend for Wednesday. Depending on how the upper
level pattern evolves, future forecasts will likely need some
adjustments over the next few days. As for temperatures, readings
should generally be a little below average with daytime highs in the
upper 60s to lower 70s and overnight lows in the lower-middle 50s.
&&
.Aviation (00Z TAF Issuance)...
Updated at 101 AM EDT May 10 2012
Light rain showers and gusty winds from an outflow boundary have
ended across the TAF sites. High pressure will build into the area
through the forecast period, keeping things dry and VFR throughout.
Expect light winds out of the north-northeast overnight, and
generally out of the north between 7-12 mph later this afternoon. A
few gusts around 13-17 mph cannot be ruled out. Otherwise, expect a
few cu around 6 k feet this afternoon, with winds going calm late
this evening.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........13
Short Term.......AL
Long Term........MJ
Aviation.........BJS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
703 AM EDT THU MAY 10 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK ACROSS DOWNEAST MAINE TODAY THEN CONTINUE
INTO NEW BRUNSWICK CANADA TONIGHT. AN UPPER LEVEL TROUGH OF LOW
PRESSURE WILL CROSS THE STATE ON FRIDAY. THE TROUGH WILL MOVE EAST
ON SATURDAY AS DRIER AIR MOVES IN.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE 0700L: BASED ON HRRR MODEL, WILL END RAIN ACROSS DOWNEAST
THIS AFTERNOON AS LOW PRESSURE QUICKLY MOVES NORTHEAST OF THE
AREA...OTHERWISE FORECAST ON TRACK.
PREVIOUS DISCUSSION:
LOW PRESSURE DEVELOPING SOUTH OF LONG ISLAND EARLY THIS MORNING
WILL QUICKLY TRACK NORTHEAST TODAY. MODELS NOW FARTHER WEST WITH
THE TRACK WITH LANDFALL AROUND BAR HARBOR AROUND NOONTIME. THE LOW
WILL THEN QUICKLY EXIT INTO NEW BRUNSWICK LATER THIS AFTERNOON.
RAIN WILL INTENSIFY THIS MORNING ESPECIALLY OVER HANCOCK AND
WASHINGTON COUNTIES AS DEEP MOISTURE, LONG MOISTURE FETCH OVER THE
ATLANTIC, AND STRONG UPPER JET CORE OF 120 KTS MOVES ACROSS THE
STATE. A BLEND OF THE MODEL QPF STILL INDICATING OVER 2 INCHES OF
RAIN POSSIBLE OVER HANCOCK AND WASHINGTON COUNTIES TAPERING TO
AROUND AN INCH ACROSS NORTHERN SECTIONS. WITH STRONG UPPER
DYNAMICS WILL INCLUDE ISOLATED THUNDER ACROSS MAINLY HANCOCK AND
WASHINGTON COUNTIES THIS MORNING. RAIN WILL END FROM WEST TO EAST
ACROSS THE REGION THIS AFTERNOON AS UPPER LEVEL DRY SLOT MOVES
ACROSS THE STATE. SCATTERED SHOWERS MAINLY ACROSS NORTHERN
SECTIONS TONIGHT AS UPPER TROUGH SLOWLY MOVES FROM QUEBEC
EASTWARD.
STRONG SOUTHERLY LOW LEVEL JET OF 60 KTS IN ADVANCE OF THE LOW
PRESSURE WILL NOSE INTO WASHINGTON COUNTY CREATING GUSTS UP TO
35 MPH THIS MORNING. AS LOW PRESSURE MOVES INLAND THIS AFTERNOON,
LOW LEVEL JET WILL MOVE EAST OF THE REGION ALLOWING WINDS TO
DIMINISH THIS AFTERNOON. FOR NOW EXPECT WINDS TO REMAIN BELOW
ADVISORY LEVEL BUT SITUATION WILL NEED TO BE CLOSELY MONITORED
TODAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE UPPER LEVEL TROUGH WHICH IS SUPPORTING OUR STORM TODAY WILL
MOVE ACROSS THE STATE ON FRIDAY. THIS WILL BRING A MOSTLY CLOUDY
DAY WITH SHOWERS SCATTERED THROUGHOUT THE REGION. THE TROUGH WILL
WEAKEN AS IT SLOWLY MOVES TO THE EAST FRIDAY AFTERNOON. THIS MAY
ALLOW SOME BREAKS OF SUNSHINE...ESPECIALLY IN WESTERN AREAS...LATE
IN THE DAY. COOLER AIR FOLLOWING THE TROUGH WILL BRING A CLEAR TO
PARTLY CLOUDY AND COOL NIGHT FRIDAY NIGHT WITH LOWS IN THE MID 30S
IN MOST LOCATIONS. DRIER AIR FOLLOWING THE TROUGH SHOULD THEN
BRING A MOSTLY SUNNY DAY ON SATURDAY IN MOST LOCATIONS. A BIT OF
COOLER AIR POOLED ALOFT AT 850 ACROSS THE NORTH WILL LIKELY RESULT
IN SOME CUMULUS CLOUDS OVER THE NORTH. CLOUDS ARE THEN EXPECTED TO
INCREASE FROM THE WEST LATE IN THE DAY AS A SMALL DISTURBANCE
APPROACHES FROM THE GREAT LAKES REGION. SOME SHOWERS MAY AFFECT
FAR WESTERN AREAS AROUND THE END OF THE DAY WITH THE APPROACH OF
THIS DISTURBANCE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A FEW SHOWERS MAY BE AROUND SATURDAY NIGHT AS A WEAK DISTURBANCE
CROSSES THE AREA. WEAK HIGH PRESSURE SHOULD THEN RETURN BRINGING
DRY CONDITIONS SUNDAY INTO MONDAY. A SOUTHWESTERLY FLOW BETWEEN
HIGH PRESSURE OFF TO THE SOUTHEAST AND A LOW IN CENTRAL CANADA
SHOULD DRAW IN INCREASINGLY WARM AIR LATE THIS WEEKEND INTO EARLY
NEXT WEEK. TEMPS MONDAY AND TUESDAY MAY REACH THE 70S OVER THE
AREA. WEDNESDAY MAY BE ANOTHER VERY WARM DAY BEFORE A COLD FRONT
APPROACHES NORTHERN AREAS LATE IN THE DAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
NEAR TERM: IFR CONDITIONS TODAY AND TONIGHT ACROSS NORTHERN
TERMINALS. IFR CONDITIONS AT KBGR AND KBHB WILL LIFT TO MVFR
AROUND 21Z TODAY AND THEN TO VFR BETWEEN 00Z AND 03Z TONIGHT.
SHORT TERM: MVFR CONDITIONS ON FRIDAY SHOULD IMPROVE TO VFR FRIDAY
NIGHT AND REMAIN VFR ON SATURDAY. CONDITIONS MAY BRIEFLY LOWER TO
MVFR SATURDAY NIGHT THEN RETURN TO VFR SUNDAY INTO MONDAY WITH THE
POSSIBLE EXCEPTION OF SOME PATCHY FOG LATE SUNDAY NIGHT OR EARLY
MONDAY MORNING.
&&
.MARINE...
NEAR TERM: STRONG SOUTHERLY LOW LEVEL JET OF 60 KTS WILL MOVE
ACROSS EASTERN SECTIONS OF OUR WATERS THIS MORNING WITH STRONG SCA
OVER ANZ050. WINDS WILL DIMINISH THIS AFTERNOON AS JET MOVES EAST OF
OUR WATERS. SOUTHERLY SWELL WILL PERSIST TONIGHT INTO FRIDAY.
SHORT TERM: WINDS AND SEAS ARE EXPECTED TO BE BELOW SCA THROUGH
THIS WEEKEND INTO EARLY NEXT WEEK.
&&
.HYDROLOGY...
TWO TO THREE INCHES OF RAIN WILL FALL ACROSS HANCOCK AND
WASHINGTON COUNTIES THROUGH THIS AFTERNOON WITH RAIN HEAVY AT
TIMES THIS MORNING. EXCESSIVE RUNOFF FROM HEAVY RAINFALL MAY CAUSE
ELEVATED LEVELS ON SMALL BROOKS AND STREAMS AND POSSIBLE MINOR
FLOODING IN POOR DRAINAGE AREAS AND LOW LYING SPOTS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT FRIDAY
FOR ANZ052.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT FRIDAY FOR ANZ050-051.
&&
$$
NEAR TERM...FOSTER
SHORT TERM...BLOOMER
LONG TERM...BLOOMER
AVIATION...FOSTER
MARINE...FOSTER/BLOOMER
HYDROLOGY...FOSTER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
454 PM EDT THU MAY 10 2012
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 447 AM EDT THU MAY 10 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE
OVER THE PACIFIC NW/SW CANADA. DOWNSTREAM...A RIDGE EXTENDS FROM THE
ROCKIES TO HUDSON BAY. THE ASSOCIATED SFC HIGH PRES RIDGE AND DRY
AIR MASS WILL DOMINATE THE AREA TODAY. NARROW STREAK OF MID CLOUDS
CURRENTLY EXTENDING FROM FAR NE MANITOBA SSE TO NRN LAKE SUPERIOR IN
A RIBBON OF WEAK WAA/ISENTROPIC ASCENT WILL LIKELY AFFECT PORTIONS
OF THE ERN FCST AREA THIS MORNING. NAM/GFS SHOW CONDENSATION PRES
DEFICITS RISING A BIT THRU THE MORNING...SO THERE MAY BE TREND FOR
MID CLOUDS TO DIMINISH AS THEY STREAK SSE. OTHERWISE...ABUNDANT
SUNSHINE AND DRY AIR MASS TODAY WILL ALLOW FOR VERY DEEP MIXING
UPWARDS OF 750-700MB PER 00Z KINL/CWPL SOUNDINGS AND NAM/GFS FCST
SOUNDINGS. THIS YIELDS MAX TEMPS WELL INTO THE 60S/AROUND 70 W AND
LOW/MID 60S E. LAKE BREEZES WILL BE THE RULE IN THE AFTN TO PROVIDE
COOLING NEAR THE GREAT LAKES. UNDER DRY AIR MASS...AFTN RH WILL BE
LOW...FALLING INTO THE 20-30PCT RANGE. FORTUNATELY...WINDS WILL BE
ON THE LIGHT SIDE.
AS SFC HIGH PRES RIDGE DRIFTS E TONIGHT...S TO SW GRADIENT FLOW WILL
DEVELOP. BEFORE GRADIENT TIGHTENS UP A BIT...TEMPS WILL HAVE A
CHANCE TO FALL QUICKLY THIS EVENING. HOWEVER...WITH PRECIPITABLE
WATER RISING TO NEAR OR ABOVE NORMAL...TEMP FALL THIS EVENING
SHOULDN`T BE ANY MORE THAN TYPICAL. AIR MASS IS DRIER OVER THE
E...SO MIN TEMPS THERE WILL BE LOWEST...PROBABLY IN THE UPPER 30S IN
THE TRADITIONAL COLD SPOTS. OTHERWISE...40S SHOULD BE THE RULE
TONIGHT WITH THE WARMER TEMPS IN THE DOWNSLOPE AREAS OUT W.
MIDLEVEL TROF CURRENTLY MOVING ONSHORE OVER THE PACIFIC NW/SW CANADA
WILL SHIFT ACROSS THE NRN PLAINS FRI WITH ASSOCIATED COLD FRONT
MOVING INTO UPPER MI. TIMING OF FRONT IS OVERALL WELL AGREED UPON BY
THE MODELS WITH MOST SHOWING FRONT REACHING WRN UPPER MI 18-21Z AND
THEN EXTENDING FROM NE LAKE SUPERIOR TO ROUGHLY KMQT/KIMT BY 00Z.
WITH ONLY SOME HIGH CLOUDS AHEAD OF FRONT...IT WILL BE A WARM DAY AS
850MB THERMAL RIDGE OF 10-12C SHIFTS ACROSS THE AREA. MAX TEMPS
SHOULD BE WELL INTO THE 70S ACROSS THE W AND CNTRL AS STRONGER S/SW
WINDS WILL PREVENT LAKE SUPERIOR LAKE BREEZE. WARMEST TEMPS WILL BE
IN THE DOWNSLOPE AREAS...POSSIBLY REACHING 80F IF THICKER CLOUDS
HOLD OFF LONG ENOUGH. TO THE E...SRLY FLOW UP LAKE MICHIGAN WILL
KEEP THE E COOLER. TEMPS SHOULD RANGE FROM THE 50S LAKESIDE E OF
KESC TO AROUND 70 TOWARD LAKE SUPERIOR. WITH HIGHER TEMPS...AN
INCREASE IN WINDS AND RH FALLING INTO THE 30-40PCT RANGE...FIRE
CONCERNS WILL INCREASE FRI IN THOSE AREAS THAT FAILED TO RECEIVE
MUCH RAINFALL DURING THE LAST WEEK. AS FOR PCPN...NARROW RIBBON OF
MOISTURE/INSTABILITY WILL KEEP SHRA CONFINED TO A NARROW CORRIDOR
VCNTY OF FRONT. INCLUDED CHC POPS JUST AFTER 18Z W...SPREADING TO
THE ERN FCST AREA AT 00Z. WHILE THUNDER POTENTIAL IS MINIMAL WITH
GFS MLCAPES 100-200J/KG...THE NAM SHOWS MLCAPE BRIEFLY RISING TO
SEVERAL HUNDRED J/KG TOWARD THE WI BORDER...SUGGESTING THUNDER CAN`T
BE RULED OUT. THUS...OPTED TO MAINTAIN A SLIGHT CHC THUNDER MENTION.
SHRA WILL END W TO E FRI NIGHT AS SHORTWAVE/COLD FRONT MAKE STEADY
EASTWARD PROGRESS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 452 PM EDT THU MAY 10 2012
SHRA WILL END W TO E FRI NIGHT AS SHORTWAVE/COLD FRONT MAKE STEADY
EASTWARD PROGRESS AND RDG BUILDS IN FROM THE WEST.
COLD FRONT WILL BE EAST OF THE CWA BY 12Z SAT SO HAVE REMOVED POPS
AND PCPN FROM SAT FCST. VERY DRY AIRMASS ASSOC WITH SFC RDG WILL
THEN BUILD OVER THE AREA ON SAT AND CONTINUE INTO SUN LEADING TO LOW
MIN RH/S AND ELEVATED FIRE WEATHER CONCERNS OVER THE WEEKEND. THE
DRY AIR WILL RESULT IN MOSTLY SUNNY SKIES OVER THE WEEKEND AND DEEP
DAYTIME MIXING TO H775 AND POSSIBLY H750. EXPECT DEWPOINT VALUES TO
FALL THROUGH THE AFTN ON SAT AND SUN AS DRIER AIR MIXES TO THE
SFC...ESPECIALLY OVER THE WRN HALF OF THE CWA. MODEL ML DEWPOINTS
ARE IN THE MID TEENS TO LOWER 20S OVER THE WEST ON SAT AND IN THE
MID 20S ON SUNDAY WHILE DEWPOINTS DROP INTO LOWER 30S BOTH DAYS
EAST...SO HAVE CONTINUED THE DOWNWARD TREND IN DEW POINTS FOR GRIDS
OVER BOTH DAYS. THE COMBINATION OF LOWERING DEW POINTS AND HIGH
TEMPS REACHING INTO THE MID 60S AWAY FROM LAKE SUPERIOR WILL PRODUCE
RH VALUES ON SAT BTWN 20-25 PERCENT AND PERHAPS EVEN THE UPPER TEENS
WEST. WITH NW WINDS OF 10-15 MPH THERE COULD BE SOME FIRE WX
CONCERNS...BUT HOPEFULLY THE 0.1 INCH OF RAIN ON FRI NIGHT WILL HELP
LIMIT THEM. FIRE WX CONCERNS WILL CONTINUE ON SUNDAY AS THE
COMBINATION OF HIGH TEMPS IN THE UPPER 60S AND LOWER 70S AND DEW
POINTS LOWERING TO MID 20S COULD DRIVE RH/S AGAIN INTO THE 20-25 PCT
RANGE AND MAYBE EVEN UPPER TEENS AT SOME WRN LOCATIONS.
SHORTWAVE ASSOC WITH THE UPPER LOW NEAR HUDSON BAY LOOKS TO STAY
GENERALLY WELL NORTH OF THE FCST AREA ON SUNDAY AND SUNDAY NIGHT PER
MODEL CONSENSUS SO WILL GO WITH DRY FCST FOR THIS TIME FRAME.
MODELS DIFFER ON TIMING OF WEAK SHORTWAVE/S MOVING THROUGH UPPER
GREAT LAKES IN NW FLOW FOR TUE THROUGH THU TIME FRAME. CONFIDENCE
FOR MEASURABLE PCPN IS LOW AT THIS POINT SO HAVE NO MORE THAN SLIGHT
CHC POPS IN FCST FOR TUE NIGHT INTO THU.
TEMPS SHOULD BE AT OR ABOVE NORMAL THROUGH THE EARLY PART OF NEXT
WEEK WITH A TEMPORARY COOL DOWN BY TUE/WED AND THEN WARMING UP ABV
NORMAL FOR THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 152 PM EDT THU MAY 10 2012
SFC HIGH PRESSURE OVER EASTERN UPPER MI WILL CONTINUE TO MOVE EAST
THIS AFTERNOON...ALLOWING FOR LIGHT WINDS AND LAKE BREEZE
DEVELOPMENT AT ALL SITES. HIGH-BASED CUMULUS FIELD SHOULD LINGER AT
IWD AND SAW BEFORE DISSIPATING EARLY THIS EVENING WITH LOSS OF
HEATING. PRESSURE GRADIENT THEN INCREASES OVERNIGHT AHEAD OF AN
APPROACHING COLD FRONT...RESULTING IN INCREASING WINDS FROM WEST TO
EAST. FRIDAY LOOKS TO HAVE FAIRLY DEEP MIXING...SO WINDS MAY GUST
OVER 20 KTS AT TIMES. A SLIGHT MOISTURE SURGE JUST BELOW H8 AROUND
IWD IN THE MORNING...AND SAW IN THE AFTERNOON...WILL BRING IN SOME
LOWER CLOUDS...BUT CONDITIONS SHOULD REMAIN JUST ABOVE VFR. RIGHT AT
THE END OF THE TAF PERIOD...THE COLD FRONT SHOULD REACH IWD WITH
QUICKLY FALLING CIGS. THE TREND WILL BE THE SAME DURING THE
AFTERNOON HOURS AT CMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 452 PM EDT THU MAY 10 2012
HIGH PRESSURE WILL REMAIN OVR MOST OF LK SUPERIOR TONIGHT LEADING TO
LIGHT WINDS. A COLD FRONT APPROACHING FROM THE NORTHERN PLAINS WILL
CAUSE WINDS TO BECOME SOUTHERLY LATE TONIGHT AND FRIDAY...BUT THE
MARINE LAYER SHOULD KEEP WINDS MOSTLY BELOW 15KTS. WINDS WILL SHIFT
TO THE NW BEHIND THE FRONT ON FRIDAY NIGHT AND THEN REMAIN OUT OF
THE WEST THROUGH THE WEEKEND. MOST AREAS SHOULD SEE WINDS STAY BELOW
20KTS DURING THE WEEKEND. WINDS SHOULD REMAIN LESS THAN 20 KTS INTO
MIDDLE PART OF NEXT WEEK AS HIGH PRESSURE IS OVER THE LK SUPERIOR
REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...VOSS
AVIATION...TK
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
152 PM EDT THU MAY 10 2012
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 447 AM EDT THU MAY 10 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE
OVER THE PACIFIC NW/SW CANADA. DOWNSTREAM...A RIDGE EXTENDS FROM THE
ROCKIES TO HUDSON BAY. THE ASSOCIATED SFC HIGH PRES RIDGE AND DRY
AIR MASS WILL DOMINATE THE AREA TODAY. NARROW STREAK OF MID CLOUDS
CURRENTLY EXTENDING FROM FAR NE MANITOBA SSE TO NRN LAKE SUPERIOR IN
A RIBBON OF WEAK WAA/ISENTROPIC ASCENT WILL LIKELY AFFECT PORTIONS
OF THE ERN FCST AREA THIS MORNING. NAM/GFS SHOW CONDENSATION PRES
DEFICITS RISING A BIT THRU THE MORNING...SO THERE MAY BE TREND FOR
MID CLOUDS TO DIMINISH AS THEY STREAK SSE. OTHERWISE...ABUNDANT
SUNSHINE AND DRY AIR MASS TODAY WILL ALLOW FOR VERY DEEP MIXING
UPWARDS OF 750-700MB PER 00Z KINL/CWPL SOUNDINGS AND NAM/GFS FCST
SOUNDINGS. THIS YIELDS MAX TEMPS WELL INTO THE 60S/AROUND 70 W AND
LOW/MID 60S E. LAKE BREEZES WILL BE THE RULE IN THE AFTN TO PROVIDE
COOLING NEAR THE GREAT LAKES. UNDER DRY AIR MASS...AFTN RH WILL BE
LOW...FALLING INTO THE 20-30PCT RANGE. FORTUNATELY...WINDS WILL BE
ON THE LIGHT SIDE.
AS SFC HIGH PRES RIDGE DRIFTS E TONIGHT...S TO SW GRADIENT FLOW WILL
DEVELOP. BEFORE GRADIENT TIGHTENS UP A BIT...TEMPS WILL HAVE A
CHANCE TO FALL QUICKLY THIS EVENING. HOWEVER...WITH PRECIPITABLE
WATER RISING TO NEAR OR ABOVE NORMAL...TEMP FALL THIS EVENING
SHOULDN`T BE ANY MORE THAN TYPICAL. AIR MASS IS DRIER OVER THE
E...SO MIN TEMPS THERE WILL BE LOWEST...PROBABLY IN THE UPPER 30S IN
THE TRADITIONAL COLD SPOTS. OTHERWISE...40S SHOULD BE THE RULE
TONIGHT WITH THE WARMER TEMPS IN THE DOWNSLOPE AREAS OUT W.
MIDLEVEL TROF CURRENTLY MOVING ONSHORE OVER THE PACIFIC NW/SW CANADA
WILL SHIFT ACROSS THE NRN PLAINS FRI WITH ASSOCIATED COLD FRONT
MOVING INTO UPPER MI. TIMING OF FRONT IS OVERALL WELL AGREED UPON BY
THE MODELS WITH MOST SHOWING FRONT REACHING WRN UPPER MI 18-21Z AND
THEN EXTENDING FROM NE LAKE SUPERIOR TO ROUGHLY KMQT/KIMT BY 00Z.
WITH ONLY SOME HIGH CLOUDS AHEAD OF FRONT...IT WILL BE A WARM DAY AS
850MB THERMAL RIDGE OF 10-12C SHIFTS ACROSS THE AREA. MAX TEMPS
SHOULD BE WELL INTO THE 70S ACROSS THE W AND CNTRL AS STRONGER S/SW
WINDS WILL PREVENT LAKE SUPERIOR LAKE BREEZE. WARMEST TEMPS WILL BE
IN THE DOWNSLOPE AREAS...POSSIBLY REACHING 80F IF THICKER CLOUDS
HOLD OFF LONG ENOUGH. TO THE E...SRLY FLOW UP LAKE MICHIGAN WILL
KEEP THE E COOLER. TEMPS SHOULD RANGE FROM THE 50S LAKESIDE E OF
KESC TO AROUND 70 TOWARD LAKE SUPERIOR. WITH HIGHER TEMPS...AN
INCREASE IN WINDS AND RH FALLING INTO THE 30-40PCT RANGE...FIRE
CONCERNS WILL INCREASE FRI IN THOSE AREAS THAT FAILED TO RECEIVE
MUCH RAINFALL DURING THE LAST WEEK. AS FOR PCPN...NARROW RIBBON OF
MOISTURE/INSTABILITY WILL KEEP SHRA CONFINED TO A NARROW CORRIDOR
VCNTY OF FRONT. INCLUDED CHC POPS JUST AFTER 18Z W...SPREADING TO
THE ERN FCST AREA AT 00Z. WHILE THUNDER POTENTIAL IS MINIMAL WITH
GFS MLCAPES 100-200J/KG...THE NAM SHOWS MLCAPE BRIEFLY RISING TO
SEVERAL HUNDRED J/KG TOWARD THE WI BORDER...SUGGESTING THUNDER CAN`T
BE RULED OUT. THUS...OPTED TO MAINTAIN A SLIGHT CHC THUNDER MENTION.
SHRA WILL END W TO E FRI NIGHT AS SHORTWAVE/COLD FRONT MAKE STEADY
EASTWARD PROGRESS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 447 AM EDT THU MAY 10 2012
COLD FRONT WILL BE QUICKLY EXITING THE AREA SAT MORNING...WITH
MUCH IF NOT ALL OF THE PCPN OUT OF UPPER MICHIGAN BY 12Z. DRY NW
FLOW WILL THEN BUILD OVER THE AREA ON SAT AND CONTINUE INTO SUN.
THIS DRY AIR WILL LEAD TO A MOSTLY SUNNY SKY AND PROVIDE DECENT
MIXING. THUS...EXPECT DEWPOINT VALUES TO FALL THROUGH THE
AFTN...ESPECIALLY OVER THE WRN HALF OF THE CWA. MODEL ML DEWPOINTS
ARE IN THE UPPER TEENS TO MID 20S OVER THE WEST...SO HAVE TRENDED
THAT DIRECTION AND DROPPED VALUES 3-5 DEGREES. MIXING TO H800-775
WOULD YIELD HIGHS IN THE LOW/MID 60S AWAY FROM LK SUPERIOR
INFLUENCES UNDER WNW WINDS. THE COMBINATION OF THESE TWO FACTORS
WILL PRODUCE RH VALUES AROUND 20-25 PERCENT...BUT IF BETTER MIXING
OCCURS...COULD SEE VALUES INTO THE UPPER TEENS. WITH WINDS OF
10-15 MPH THERE COULD BE SOME FIRE WX CONCERNS...BUT HOPEFULLY THE
0.1-0.15IN OF RAIN ON FRI NIGHT WILL LIMIT THEM.
SAT NIGHT...HIGH WILL STILL BE CENTERED OVER CNTRL PLAINS/ROCKIES
AND SFC RIDGE SLIDES SE INTO LOWER MI. THIS WILL KEEP A SLIGHTLY
STRONGER PRESSURE GRADIENT ACROSS THE AREA AND SHOULD KEEP LOWS
AT OR SLIGHTLY ABOVE NORMAL EVEN WITH THE CLEAR SKIES.
SUN LOOKS TO BE SIMILAR TO SAT...WITH DRY AIR STILL IN PLACE AND
PRODUCING A MOSTLY SUNNY SKY. ONCE AGAIN...DEWPOINTS ARE THE MAIN
CONCERN AND HAVE DROPPED VALUES INTO THE LOWER 30S. ML DEWPOINTS
ARE SHOWING VALUES IN THE UPPER 20S...SO THEY MAY NEED TO BE
REDUCED IF TREND CONTINUES. WITH HIGHS IN THE 60S...WILL SEE RH
VALUES DROPPING TOWARDS 25 PERCENT AGAIN.
SUN NIGHT THROUGH WED...
MODELS DIFFER IN THE HANDLING OF A SHORTWAVE ROTATING AROUND THE
UPPER LOW STATIONED OVER HUDSON BAY. 12Z ECMWF THE MOST PRONOUNCED
AND S WITH THIS WAVE MOVING THROUGH SRN CANADA AND UPPER GREAT LKS
ON SUN NIGHT...BUT THE LATE ARRIVING 00Z RUN HAS WEAKENED THIS
CONSIDERABLY. 00Z GFS/GEM SHOW WEAKER VARIATIONS OF THIS WAVE MOVING
THROUGH THE NW FLOW AND STAYING MAINLY IN SRN CANADA. PREVIOUS FCST
HAD SLIGHT CHANCES OVER NRN LK SUPERIOR AND FEEL THAT IS THE WAY TO
GO AT THIS POINT. OTHERWISE...THE REST OF THE EXTENDED FORECAST
LOOKS TO BE DOMINATED BY NW FLOW ALOFT. SFC RIDGE FROM THE CNTRL
PLAINS/ROCKIES WILL TRY TO BUILD BACK OVER THE AREA FOR MON/TUES.
THIS LEAVES THE AREA UNDER DRY AIR ALOFT AND FAIRLY LIGHT WINDS.
MODELS HINTING AT ANOTHER WEAK COLD FRONT MOVING THROUGH THE UPPER
GREAT LKS TUES NIGHT INTO WED...BUT CONFIDENCE FOR MEASURABLE
PCPN IS LOW AT THIS POINT. TEMPS SHOULD BE AT OR ABOVE NORMAL
THROUGH THE FIRST PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 152 PM EDT THU MAY 10 2012
SFC HIGH PRESSURE OVER EASTERN UPPER MI WILL CONTINUE TO MOVE EAST
THIS AFTERNOON...ALLOWING FOR LIGHT WINDS AND LAKE BREEZE
DEVELOPMENT AT ALL SITES. HIGH-BASED CUMULUS FIELD SHOULD LINGER AT
IWD AND SAW BEFORE DISSIPATING EARLY THIS EVENING WITH LOSS OF
HEATING. PRESSURE GRADIENT THEN INCREASES OVERNIGHT AHEAD OF AN
APPROACHING COLD FRONT...RESULTING IN INCREASING WINDS FROM WEST TO
EAST. FRIDAY LOOKS TO HAVE FAIRLY DEEP MIXING...SO WINDS MAY GUST
OVER 20 KTS AT TIMES. A SLIGHT MOISTURE SURGE JUST BELOW H8 AROUND
IWD IN THE MORNING...AND SAW IN THE AFTERNOON...WILL BRING IN SOME
LOWER CLOUDS...BUT CONDITIONS SHOULD REMAIN JUST ABOVE VFR. RIGHT AT
THE END OF THE TAF PERIOD...THE COLD FRONT SHOULD REACH IWD WITH
QUICKLY FALLING CIGS. THE TREND WILL BE THE SAME DURING THE
AFTERNOON HOURS AT CMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EDT THU MAY 10 2012
HIGH PRESSURE WILL COVER LAKE SUPERIOR TODAY AND LEAD TO LIGHT
WINDS. A COLD FRONT APPROACHING FROM THE NORTHERN PLAINS WILL CAUSE
WINDS TO BECOME SOUTHERLY TONIGHT AND FRIDAY...BUT THE MARINE
LAYER SHOULD KEEP WINDS BELOW 15KTS. WINDS WILL SHIFT TO THE NW
BEHIND THE FRONT ON FRIDAY NIGHT AND THEN REMAIN OUT OF THE WEST
THROUGH THE WEEKEND. MOSTLY AREAS SHOULD SEE WINDS STAY BELOW 20KTS
DURING THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...TK
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
730 AM EDT THU MAY 10 2012
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 447 AM EDT THU MAY 10 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE
OVER THE PACIFIC NW/SW CANADA. DOWNSTREAM...A RIDGE EXTENDS FROM THE
ROCKIES TO HUDSON BAY. THE ASSOCIATED SFC HIGH PRES RIDGE AND DRY
AIR MASS WILL DOMINATE THE AREA TODAY. NARROW STREAK OF MID CLOUDS
CURRENTLY EXTENDING FROM FAR NE MANITOBA SSE TO NRN LAKE SUPERIOR IN
A RIBBON OF WEAK WAA/ISENTROPIC ASCENT WILL LIKELY AFFECT PORTIONS
OF THE ERN FCST AREA THIS MORNING. NAM/GFS SHOW CONDENSATION PRES
DEFICITS RISING A BIT THRU THE MORNING...SO THERE MAY BE TREND FOR
MID CLOUDS TO DIMINISH AS THEY STREAK SSE. OTHERWISE...ABUNDANT
SUNSHINE AND DRY AIR MASS TODAY WILL ALLOW FOR VERY DEEP MIXING
UPWARDS OF 750-700MB PER 00Z KINL/CWPL SOUNDINGS AND NAM/GFS FCST
SOUNDINGS. THIS YIELDS MAX TEMPS WELL INTO THE 60S/AROUND 70 W AND
LOW/MID 60S E. LAKE BREEZES WILL BE THE RULE IN THE AFTN TO PROVIDE
COOLING NEAR THE GREAT LAKES. UNDER DRY AIR MASS...AFTN RH WILL BE
LOW...FALLING INTO THE 20-30PCT RANGE. FORTUNATELY...WINDS WILL BE
ON THE LIGHT SIDE.
AS SFC HIGH PRES RIDGE DRIFTS E TONIGHT...S TO SW GRADIENT FLOW WILL
DEVELOP. BEFORE GRADIENT TIGHTENS UP A BIT...TEMPS WILL HAVE A
CHANCE TO FALL QUICKLY THIS EVENING. HOWEVER...WITH PRECIPITABLE
WATER RISING TO NEAR OR ABOVE NORMAL...TEMP FALL THIS EVENING
SHOULDN`T BE ANY MORE THAN TYPICAL. AIR MASS IS DRIER OVER THE
E...SO MIN TEMPS THERE WILL BE LOWEST...PROBABLY IN THE UPPER 30S IN
THE TRADITIONAL COLD SPOTS. OTHERWISE...40S SHOULD BE THE RULE
TONIGHT WITH THE WARMER TEMPS IN THE DOWNSLOPE AREAS OUT W.
MIDLEVEL TROF CURRENTLY MOVING ONSHORE OVER THE PACIFIC NW/SW CANADA
WILL SHIFT ACROSS THE NRN PLAINS FRI WITH ASSOCIATED COLD FRONT
MOVING INTO UPPER MI. TIMING OF FRONT IS OVERALL WELL AGREED UPON BY
THE MODELS WITH MOST SHOWING FRONT REACHING WRN UPPER MI 18-21Z AND
THEN EXTENDING FROM NE LAKE SUPERIOR TO ROUGHLY KMQT/KIMT BY 00Z.
WITH ONLY SOME HIGH CLOUDS AHEAD OF FRONT...IT WILL BE A WARM DAY AS
850MB THERMAL RIDGE OF 10-12C SHIFTS ACROSS THE AREA. MAX TEMPS
SHOULD BE WELL INTO THE 70S ACROSS THE W AND CNTRL AS STRONGER S/SW
WINDS WILL PREVENT LAKE SUPERIOR LAKE BREEZE. WARMEST TEMPS WILL BE
IN THE DOWNSLOPE AREAS...POSSIBLY REACHING 80F IF THICKER CLOUDS
HOLD OFF LONG ENOUGH. TO THE E...SRLY FLOW UP LAKE MICHIGAN WILL
KEEP THE E COOLER. TEMPS SHOULD RANGE FROM THE 50S LAKESIDE E OF
KESC TO AROUND 70 TOWARD LAKE SUPERIOR. WITH HIGHER TEMPS...AN
INCREASE IN WINDS AND RH FALLING INTO THE 30-40PCT RANGE...FIRE
CONCERNS WILL INCREASE FRI IN THOSE AREAS THAT FAILED TO RECEIVE
MUCH RAINFALL DURING THE LAST WEEK. AS FOR PCPN...NARROW RIBBON OF
MOISTURE/INSTABILITY WILL KEEP SHRA CONFINED TO A NARROW CORRIDOR
VCNTY OF FRONT. INCLUDED CHC POPS JUST AFTER 18Z W...SPREADING TO
THE ERN FCST AREA AT 00Z. WHILE THUNDER POTENTIAL IS MINIMAL WITH
GFS MLCAPES 100-200J/KG...THE NAM SHOWS MLCAPE BRIEFLY RISING TO
SEVERAL HUNDRED J/KG TOWARD THE WI BORDER...SUGGESTING THUNDER CAN`T
BE RULED OUT. THUS...OPTED TO MAINTAIN A SLIGHT CHC THUNDER MENTION.
SHRA WILL END W TO E FRI NIGHT AS SHORTWAVE/COLD FRONT MAKE STEADY
EASTWARD PROGRESS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 447 AM EDT THU MAY 10 2012
COLD FRONT WILL BE QUICKLY EXITING THE AREA SAT MORNING...WITH
MUCH IF NOT ALL OF THE PCPN OUT OF UPPER MICHIGAN BY 12Z. DRY NW
FLOW WILL THEN BUILD OVER THE AREA ON SAT AND CONTINUE INTO SUN.
THIS DRY AIR WILL LEAD TO A MOSTLY SUNNY SKY AND PROVIDE DECENT
MIXING. THUS...EXPECT DEWPOINT VALUES TO FALL THROUGH THE
AFTN...ESPECIALLY OVER THE WRN HALF OF THE CWA. MODEL ML DEWPOINTS
ARE IN THE UPPER TEENS TO MID 20S OVER THE WEST...SO HAVE TRENDED
THAT DIRECTION AND DROPPED VALUES 3-5 DEGREES. MIXING TO H800-775
WOULD YIELD HIGHS IN THE LOW/MID 60S AWAY FROM LK SUPERIOR
INFLUENCES UNDER WNW WINDS. THE COMBINATION OF THESE TWO FACTORS
WILL PRODUCE RH VALUES AROUND 20-25 PERCENT...BUT IF BETTER MIXING
OCCURS...COULD SEE VALUES INTO THE UPPER TEENS. WITH WINDS OF
10-15 MPH THERE COULD BE SOME FIRE WX CONCERNS...BUT HOPEFULLY THE
0.1-0.15IN OF RAIN ON FRI NIGHT WILL LIMIT THEM.
SAT NIGHT...HIGH WILL STILL BE CENTERED OVER CNTRL PLAINS/ROCKIES
AND SFC RIDGE SLIDES SE INTO LOWER MI. THIS WILL KEEP A SLIGHTLY
STRONGER PRESSURE GRADIENT ACROSS THE AREA AND SHOULD KEEP LOWS
AT OR SLIGHTLY ABOVE NORMAL EVEN WITH THE CLEAR SKIES.
SUN LOOKS TO BE SIMILAR TO SAT...WITH DRY AIR STILL IN PLACE AND
PRODUCING A MOSTLY SUNNY SKY. ONCE AGAIN...DEWPOINTS ARE THE MAIN
CONCERN AND HAVE DROPPED VALUES INTO THE LOWER 30S. ML DEWPOINTS
ARE SHOWING VALUES IN THE UPPER 20S...SO THEY MAY NEED TO BE
REDUCED IF TREND CONTINUES. WITH HIGHS IN THE 60S...WILL SEE RH
VALUES DROPPING TOWARDS 25 PERCENT AGAIN.
SUN NIGHT THROUGH WED...
MODELS DIFFER IN THE HANDLING OF A SHORTWAVE ROTATING AROUND THE
UPPER LOW STATIONED OVER HUDSON BAY. 12Z ECMWF THE MOST PRONOUNCED
AND S WITH THIS WAVE MOVING THROUGH SRN CANADA AND UPPER GREAT LKS
ON SUN NIGHT...BUT THE LATE ARRIVING 00Z RUN HAS WEAKENED THIS
CONSIDERABLY. 00Z GFS/GEM SHOW WEAKER VARIATIONS OF THIS WAVE MOVING
THROUGH THE NW FLOW AND STAYING MAINLY IN SRN CANADA. PREVIOUS FCST
HAD SLIGHT CHANCES OVER NRN LK SUPERIOR AND FEEL THAT IS THE WAY TO
GO AT THIS POINT. OTHERWISE...THE REST OF THE EXTENDED FORECAST
LOOKS TO BE DOMINATED BY NW FLOW ALOFT. SFC RIDGE FROM THE CNTRL
PLAINS/ROCKIES WILL TRY TO BUILD BACK OVER THE AREA FOR MON/TUES.
THIS LEAVES THE AREA UNDER DRY AIR ALOFT AND FAIRLY LIGHT WINDS.
MODELS HINTING AT ANOTHER WEAK COLD FRONT MOVING THROUGH THE UPPER
GREAT LKS TUES NIGHT INTO WED...BUT CONFIDENCE FOR MEASURABLE
PCPN IS LOW AT THIS POINT. TEMPS SHOULD BE AT OR ABOVE NORMAL
THROUGH THE FIRST PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 728 AM EDT THU MAY 10 2012
EXPECT VFR CONDITIONS/LIGHT WINDS WITH DRY HI PRES DOMINATING THIS
FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EDT THU MAY 10 2012
HIGH PRESSURE WILL COVER LAKE SUPERIOR TODAY AND LEAD TO LIGHT
WINDS. A COLD FRONT APPROACHING FROM THE NORTHERN PLAINS WILL CAUSE
WINDS TO BECOME SOUTHERLY TONIGHT AND FRIDAY...BUT THE MARINE
LAYER SHOULD KEEP WINDS BELOW 15KTS. WINDS WILL SHIFT TO THE NW
BEHIND THE FRONT ON FRIDAY NIGHT AND THEN REMAIN OUT OF THE WEST
THROUGH THE WEEKEND. MOSTLY AREAS SHOULD SEE WINDS STAY BELOW 20KTS
DURING THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
448 AM EDT THU MAY 10 2012
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 447 AM EDT THU MAY 10 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING ONSHORE
OVER THE PACIFIC NW/SW CANADA. DOWNSTREAM...A RIDGE EXTENDS FROM THE
ROCKIES TO HUDSON BAY. THE ASSOCIATED SFC HIGH PRES RIDGE AND DRY
AIR MASS WILL DOMINATE THE AREA TODAY. NARROW STREAK OF MID CLOUDS
CURRENTLY EXTENDING FROM FAR NE MANITOBA SSE TO NRN LAKE SUPERIOR IN
A RIBBON OF WEAK WAA/ISENTROPIC ASCENT WILL LIKELY AFFECT PORTIONS
OF THE ERN FCST AREA THIS MORNING. NAM/GFS SHOW CONDENSATION PRES
DEFICITS RISING A BIT THRU THE MORNING...SO THERE MAY BE TREND FOR
MID CLOUDS TO DIMINISH AS THEY STREAK SSE. OTHERWISE...ABUNDANT
SUNSHINE AND DRY AIR MASS TODAY WILL ALLOW FOR VERY DEEP MIXING
UPWARDS OF 750-700MB PER 00Z KINL/CWPL SOUNDINGS AND NAM/GFS FCST
SOUNDINGS. THIS YIELDS MAX TEMPS WELL INTO THE 60S/AROUND 70 W AND
LOW/MID 60S E. LAKE BREEZES WILL BE THE RULE IN THE AFTN TO PROVIDE
COOLING NEAR THE GREAT LAKES. UNDER DRY AIR MASS...AFTN RH WILL BE
LOW...FALLING INTO THE 20-30PCT RANGE. FORTUNATELY...WINDS WILL BE
ON THE LIGHT SIDE.
AS SFC HIGH PRES RIDGE DRIFTS E TONIGHT...S TO SW GRADIENT FLOW WILL
DEVELOP. BEFORE GRADIENT TIGHTENS UP A BIT...TEMPS WILL HAVE A
CHANCE TO FALL QUICKLY THIS EVENING. HOWEVER...WITH PRECIPITABLE
WATER RISING TO NEAR OR ABOVE NORMAL...TEMP FALL THIS EVENING
SHOULDN`T BE ANY MORE THAN TYPICAL. AIR MASS IS DRIER OVER THE
E...SO MIN TEMPS THERE WILL BE LOWEST...PROBABLY IN THE UPPER 30S IN
THE TRADITIONAL COLD SPOTS. OTHERWISE...40S SHOULD BE THE RULE
TONIGHT WITH THE WARMER TEMPS IN THE DOWNSLOPE AREAS OUT W.
MIDLEVEL TROF CURRENTLY MOVING ONSHORE OVER THE PACIFIC NW/SW CANADA
WILL SHIFT ACROSS THE NRN PLAINS FRI WITH ASSOCIATED COLD FRONT
MOVING INTO UPPER MI. TIMING OF FRONT IS OVERALL WELL AGREED UPON BY
THE MODELS WITH MOST SHOWING FRONT REACHING WRN UPPER MI 18-21Z AND
THEN EXTENDING FROM NE LAKE SUPERIOR TO ROUGHLY KMQT/KIMT BY 00Z.
WITH ONLY SOME HIGH CLOUDS AHEAD OF FRONT...IT WILL BE A WARM DAY AS
850MB THERMAL RIDGE OF 10-12C SHIFTS ACROSS THE AREA. MAX TEMPS
SHOULD BE WELL INTO THE 70S ACROSS THE W AND CNTRL AS STRONGER S/SW
WINDS WILL PREVENT LAKE SUPERIOR LAKE BREEZE. WARMEST TEMPS WILL BE
IN THE DOWNSLOPE AREAS...POSSIBLY REACHING 80F IF THICKER CLOUDS
HOLD OFF LONG ENOUGH. TO THE E...SRLY FLOW UP LAKE MICHIGAN WILL
KEEP THE E COOLER. TEMPS SHOULD RANGE FROM THE 50S LAKESIDE E OF
KESC TO AROUND 70 TOWARD LAKE SUPERIOR. WITH HIGHER TEMPS...AN
INCREASE IN WINDS AND RH FALLING INTO THE 30-40PCT RANGE...FIRE
CONCERNS WILL INCREASE FRI IN THOSE AREAS THAT FAILED TO RECEIVE
MUCH RAINFALL DURING THE LAST WEEK. AS FOR PCPN...NARROW RIBBON OF
MOISTURE/INSTABILITY WILL KEEP SHRA CONFINED TO A NARROW CORRIDOR
VCNTY OF FRONT. INCLUDED CHC POPS JUST AFTER 18Z W...SPREADING TO
THE ERN FCST AREA AT 00Z. WHILE THUNDER POTENTIAL IS MINIMAL WITH
GFS MLCAPES 100-200J/KG...THE NAM SHOWS MLCAPE BRIEFLY RISING TO
SEVERAL HUNDRED J/KG TOWARD THE WI BORDER...SUGGESTING THUNDER CAN`T
BE RULED OUT. THUS...OPTED TO MAINTAIN A SLIGHT CHC THUNDER MENTION.
SHRA WILL END W TO E FRI NIGHT AS SHORTWAVE/COLD FRONT MAKE STEADY
EASTWARD PROGRESS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 447 AM EDT THU MAY 10 2012
COLD FRONT WILL BE QUICKLY EXITING THE AREA SAT MORNING...WITH
MUCH IF NOT ALL OF THE PCPN OUT OF UPPER MICHIGAN BY 12Z. DRY NW
FLOW WILL THEN BUILD OVER THE AREA ON SAT AND CONTINUE INTO SUN.
THIS DRY AIR WILL LEAD TO A MOSTLY SUNNY SKY AND PROVIDE DECENT
MIXING. THUS...EXPECT DEWPOINT VALUES TO FALL THROUGH THE
AFTN...ESPECIALLY OVER THE WRN HALF OF THE CWA. MODEL ML DEWPOINTS
ARE IN THE UPPER TEENS TO MID 20S OVER THE WEST...SO HAVE TRENDED
THAT DIRECTION AND DROPPED VALUES 3-5 DEGREES. MIXING TO H800-775
WOULD YIELD HIGHS IN THE LOW/MID 60S AWAY FROM LK SUPERIOR
INFLUENCES UNDER WNW WINDS. THE COMBINATION OF THESE TWO FACTORS
WILL PRODUCE RH VALUES AROUND 20-25 PERCENT...BUT IF BETTER MIXING
OCCURS...COULD SEE VALUES INTO THE UPPER TEENS. WITH WINDS OF
10-15 MPH THERE COULD BE SOME FIRE WX CONCERNS...BUT HOPEFULLY THE
0.1-0.15IN OF RAIN ON FRI NIGHT WILL LIMIT THEM.
SAT NIGHT...HIGH WILL STILL BE CENTERED OVER CNTRL PLAINS/ROCKIES
AND SFC RIDGE SLIDES SE INTO LOWER MI. THIS WILL KEEP A SLIGHTLY
STRONGER PRESSURE GRADIENT ACROSS THE AREA AND SHOULD KEEP LOWS
AT OR SLIGHTLY ABOVE NORMAL EVEN WITH THE CLEAR SKIES.
SUN LOOKS TO BE SIMILAR TO SAT...WITH DRY AIR STILL IN PLACE AND
PRODUCING A MOSTLY SUNNY SKY. ONCE AGAIN...DEWPOINTS ARE THE MAIN
CONCERN AND HAVE DROPPED VALUES INTO THE LOWER 30S. ML DEWPOINTS
ARE SHOWING VALUES IN THE UPPER 20S...SO THEY MAY NEED TO BE
REDUCED IF TREND CONTINUES. WITH HIGHS IN THE 60S...WILL SEE RH
VALUES DROPPING TOWARDS 25 PERCENT AGAIN.
SUN NIGHT THROUGH WED...
MODELS DIFFER IN THE HANDLING OF A SHORTWAVE ROTATING AROUND THE
UPPER LOW STATIONED OVER HUDSON BAY. 12Z ECMWF THE MOST PRONOUNCED
AND S WITH THIS WAVE MOVING THROUGH SRN CANADA AND UPPER GREAT LKS
ON SUN NIGHT...BUT THE LATE ARRIVING 00Z RUN HAS WEAKENED THIS
CONSIDERABLY. 00Z GFS/GEM SHOW WEAKER VARIATIONS OF THIS WAVE MOVING
THROUGH THE NW FLOW AND STAYING MAINLY IN SRN CANADA. PREVIOUS FCST
HAD SLIGHT CHANCES OVER NRN LK SUPERIOR AND FEEL THAT IS THE WAY TO
GO AT THIS POINT. OTHERWISE...THE REST OF THE EXTENDED FORECAST
LOOKS TO BE DOMINATED BY NW FLOW ALOFT. SFC RIDGE FROM THE CNTRL
PLAINS/ROCKIES WILL TRY TO BUILD BACK OVER THE AREA FOR MON/TUES.
THIS LEAVES THE AREA UNDER DRY AIR ALOFT AND FAIRLY LIGHT WINDS.
MODELS HINTING AT ANOTHER WEAK COLD FRONT MOVING THROUGH THE UPPER
GREAT LKS TUES NIGHT INTO WED...BUT CONFIDENCE FOR MEASURABLE
PCPN IS LOW AT THIS POINT. TEMPS SHOULD BE AT OR ABOVE NORMAL
THROUGH THE FIRST PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 130 AM EDT THU MAY 10 2012
EXPECT VFR CONDITIONS/LIGHT WINDS WITH DRY HI PRES DOMINATING THIS
FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EDT THU MAY 10 2012
HIGH PRESSURE WILL COVER LAKE SUPERIOR TODAY AND LEAD TO LIGHT
WINDS. A COLD FRONT APPROACHING FROM THE NORTHERN PLAINS WILL CAUSE
WINDS TO BECOME SOUTHERLY TONIGHT AND FRIDAY...BUT THE MARINE
LAYER SHOULD KEEP WINDS BELOW 15KTS. WINDS WILL SHIFT TO THE NW
BEHIND THE FRONT ON FRIDAY NIGHT AND THEN REMAIN OUT OF THE WEST
THROUGH THE WEEKEND. MOSTLY AREAS SHOULD SEE WINDS STAY BELOW 20KTS
DURING THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1045 PM MDT WED MAY 9 2012
AVIATION SECTION UPDATED
.DISCUSSION...
UPDATE FORTHCOMING. HAVE LOWERED POPS ACROSS THE NORTHERN PORTION OF
THE COUNTY WARNING AREA UNTIL MIDNIGHT. APPROACHING COLD FRONT HAS
SLOWED A LITTLE AND THE AIRMASS OVER THE COUNTY WARNING AREA IS VERY
DRY. EXPECT LITTLE DEVELOPMENT THE REMAINDER OF THE EVENING. THE
COLD FRONT SHOULD PUSH THROUGH THE GREAT FALLS AREA AFTER MIDNIGHT.
SHOWERS LIKELY TO DEVELOP WITH FRONTAL PASSAGE BUT MODELS ARE
BEGINNING TO SCALE BACK QPF NUMBERS. HRRR RADAR PROJECTIONS HAVE A
NARROW BAND OF PRECIPITATION ASSOCIATED WITH THE COLD FRONT AND
LATEST NAM QPF VALUES HAVE NO PRECIPITATION FOR GREAT FALLS AND
POINTS FURTHER NORTH. MIDNIGHT SHIFT WILL HAVE THE COMPLETE 00Z RUNS
TO DETERMINE IF POPS NEED TO BE SCALED BACK THURSDAY MORNING.
EMANUEL
&&
.AVIATION...
UPDATED 0500Z.
PACIFIC COOL FRONT IS SLOWLY MOVING THROUGH THE REGION THIS EVENING.
THE FRONTAL PASSAGE IS NOT A SHARP BOUNDARY...BUT RATHER A GRADUAL
FRONTAL PASSAGE. EXPECT A NARROW BAND OF PRECIPITATION TO
DEVELOP...GENERALLY SOUTH OF A LINE FROM HAVRE TO GREAT FALLS TO
HELENA BY 12Z...AND THEN GRADUALLY MOVE EASTWARD DURING THE MORNING
HOURS. ANOTHER SMALL AREA OF SHOWERS WILL DEVELOP BY LATE MORNING IN
THE CUT BANK AREA. SOME IFR CONDITIONS ARE POSSIBLE IN THE MOUNTAINS
AND THROUGH THE PASSES...ALONG WITH THE CUT BANK UNTIL MID AFTERNOON
THURSDAY. DRY WEATHER WITH VFR CONDITIONS ARE EXPECTED ACROSS THE
REGION AFTER 01Z ON FRIDAY. BRUSDA
&&
.PREV DISCUSSION...ISSUED 241 PM MDT WED MAY 9 2012
TONIGHT THROUGH FRIDAY EVENING...CONTINUED GOOD AGREEMENT AMONG
MODELS WITH A PACIFIC TROF BRINGING A SURFACE COLD FRONT EAST OF
THE CONTINENTAL DIVIDE THIS EVENING. THE FRONT SHOULD PUSH
THROUGH CENTRAL AND SOUTHWEST MT TONIGHT AND DURING THE OVERNIGHT
HOURS. AN ISOLATED SHOWER OR TWO MAY POP UP AHEAD OF THE FRONT BUT
NOTHING MAJOR IS EXPECTED. PROBABILITY FOR PRECIP WILL INCREASE
BEHIND THE FRONT AS ADDITIONAL MOISTURE ARRIVES ALONG WITH COOLER
TEMPERATURES. FREEZING LEVELS WILL FALL THROUGH THE DAY THURSDAY
CREATING FAVORABLE CONDITIONS FOR LIGHT SNOW IN THE MTNS AND FOR
SOME LOCATIONS TO SEE GRAUPEL/SMALL HAIL WITH RAIN SHOWERS THURS
AFTERNOON. PRECIP SHOULD TAPER OFF THURS NIGHT AS THE TROF
CONTINUES EAST ACROSS MONTANA. AN UPPER LEVEL RIDGE BEGINS TO
BUILD BACK IN OVER THE REGION FRI BRINGING A RETURN OF WARM AND
DRY CONDITIONS. AS FOR TEMPERATURES...THE COLDER AIRMASS
ASSOCIATED WITH THE INCOMING FRONT WILL DROP OVERNIGHT LOW TEMPS
TONIGHT INTO THE 20S IN THE MOUNTAINS AND 30S TO LOW 40S ACROSS
THE PLAINS AND VALLEYS. HIGHS IN THE MID 40S TO LOW 50S ON
THURSDAY SHOULD RETURN TO THE UPPER 50S TO LOW 60S ON FRIDAY.
FRIDAY NIGHT THROUGH WEDNESDAY...AN UPPER LEVEL RIDGE OF HIGH
PRESSURE BECOMES ESTABLISHED OVER THE NORTHERN ROCKIES FRIDAY NIGHT
AND STRENGTHENS OVER MUCH OF THE WESTERN U.S. THIS WEEKEND THROUGH
AT LEAST THE FIRST HALF OF NEXT WEEK. THIS WILL BRING AN EXTENDED
PERIOD OF MAINLY DRY WEATHER TO THE FORECAST AREA WITH AFTERNOON
TEMPERATURES INITIALLY NEAR SEASONAL AVERAGES ON SATURDAY...RISING
TO 10-15 DEGREES ABOVE AVERAGE FROM SUNDAY THROUGH THE FIRST HALF OF
NEXT WEEK. OVERNIGHT LOW TEMPERATURES FRIDAY NIGHT/SATURDAY MORNING
WILL LIKELY FALL TO NEAR FREEZING IN MANY AREAS AGAIN WITH WARMING
MINIMUM TEMPS THEREAFTER. SURFACE PRESSURE GRADIENTS AND WINDS ALOFT
ARE RELATIVELY WEAK THROUGH THE PERIOD...WITH SURFACE WINDS EXPECTED
TO BE RELATIVELY LIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 41 52 31 59 / 30 60 20 0
CTB 34 47 27 60 / 10 50 20 0
HLN 41 55 31 63 / 40 60 20 0
BZN 37 54 26 61 / 20 60 10 0
WEY 31 53 24 57 / 10 30 20 0
DLN 39 54 25 61 / 30 40 10 0
HVR 40 50 30 60 / 20 70 30 0
LWT 37 48 29 56 / 30 70 30 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
126 AM EDT THU MAY 10 2012
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL DIG ACROSS THE AREA TODAY GENERATING A
FEW SHOWERS AND THUNDERSTORMS THIS AFTERNOON. HIGH PRESSURE WILL
THEN GRADUALLY BUILD ACROSS THE REGION DURING THE REMAINDER OF THE
WEEK BRINGING IMPROVING CONDITIONS ON THURSDAY AND DRY WEATHER FOR
FRIDAY AND SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1245 AM...HAVE UPDATED THE FORECAST MERELY TO KEEP IT IN
LINE WITH CURRENT OBS AND RECENT RADAR/SATELLITE
TRENDS...OTHERWISE THERE HAVE BEEN NO CHANGES TO THE PREVIOUS
FORECAST THINKING...WHICH FOLLOWS BELOW.
AN UPPER LEVEL TROF WILL VERY SLOWLY APPROACH FROM THE WEST
OVERNIGHT...EVENTUALLY SETTLING ACROSS WESTERN NEW YORK BY DAYBREAK.
DESPITE THE APPROACH OF THIS FEATURE...THE LOSS OF DAYTIME HEATING
HAS KEYED THE DEMISE OF SHOWERS ACROSS WESTERN NEW YORK.
CONSENSUS QPF OF THE NAM12/RGEM BOTH SHOW LIGHT QPF IN UPSLOPE
REGIONS...BUT LOOKING AT THE OMEGA FIELD...NEARLY ALL THE LIFT IS
GENERATED IN THE LOWEST 3000 FT. THIS WILL PROBABLY NOT BE DEEP
ENOUGH TO PRODUCE SHOWERS. THE HRRR TENDS TO SUPPORT THIS
CONCLUSION...FORECASTING MINIMAL QPF OVERNIGHT. WITH THE UPPER
TROF...AND A LIMITED CHANCE FOR DRIZZLE...WILL HANG ONTO 20 SLIGHT
CHANCE POPS...BUT OUTSIDE OF SOME LINGERING SHOWERS...EXPECT A
MAINLY DRY NIGHT. THERE IS QUITE A BIT OF CLOUD COVER ASSOCIATED
WITH THE UPPER LOW...SO THIS WILL LIMIT RADIATIONAL
COOLING...THOUGH THE NORTHERLY FLOW WILL ADVECT SLIGHTLY COLDER
TEMPERATURES IN. LOWS SHOULD MAINLY BE IN THE 40S ACROSS THE
REGION.
THURSDAY...UPPER TROUGH AXIS WILL BE LOCATED OVER WESTERN NEW YORK
SHIFTING EASTWARD AND CUTTING OFF THROUGH THE DAY. 543 DM LOW
CENTERED OVER SOUTHERN QUEBEC WILL PROVIDE COLD AIR ALOFT YIELDING
INSTABILITY CLOUDS ACROSS THE FORECAST AREA WITH A CHANCE FOR
INSTABILITY SHOWERS FOCUSED MAINLY ACROSS THE COUNTIES EAST OF LAKE
ONTARIO CLOSER TO THE UPPER LOW. MANY LOCATIONS WILL ONLY TOP OUT IN
THE MID TO UPPER 50S WITH THE CLOUD COVER AND COLD AIR ALOFT...850MB
TEMPS NEAR 0C. A FEW AREAS COULD SEE 60. BREEZY WEST TO NORTHWEST
WINDS WILL ALSO DEVELOP IN THE AFTERNOON AS THE SURFACE LOW NEAR
OTTAWA CANADA SHIFTS EAST OVER MAINE AND DEEPENS. A COOL...CLOUDY
AND BREEZY DAY TO SUM IT UP.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
A HIGH AMPLITUDE RIDGE WILL FORCE A BROAD SURFACE RIDGE INTO THE
EASTERN GREAT LAKES REGION THURSDAY NIGHT. THIS WILL BRING A
CLEARING TREND AND THE RISK FOR FROST...ESPECIALLY TO INTERIOR
SECTIONS OF THE SOUTHERN TIER WHERE TEMPERATURES WILL FALL TO THE
MID 30S IN SPOTS...POSSIBLY TO NEAR FREEZING IN THE GENESEE VALLEY.
FRIDAY SHOULD SEE PLENTY OF SUNSHINE...ALTHOUGH THERE MAY BE SOME
DIURNALLY DRIVEN CUMULUS WITH DEPARTING COLD POOL. WITH THE
ADDITIONAL SUNSHINE HIGHS WILL BE A SOLID 5 TO 10 DEGREES WARMER
THAN THURSDAY...MAINLY IN THE MID TO UPPER 60S.
SKIES WILL REMAIN CLEAR DURING FRIDAY NIGHT AND THE APPROACH OF A
WEAK COLD FRONT WILL INCREASE THE SOUTHWESTERLY BREEZE OVERNIGHT...
MIXING THE BOUNDARY LAYER AND HOLDING TEMPS LOWER TO MID 40S...
ALLEVIATING THE RISK OF FROST.
SATURDAY WILL ALSO BE A SUNNY DAY FOR THE MOST PART...SOME HIGH
CLOUDS STREAMING IN AND THICKENING THROUGH THE AFTERNOON. WILL SEE
HIGH TEMPS IN THE MID/UPR 60S EAST OF LAKE ONTARIO WITH LOWER 70S
ELSEWHERE AS 850MB TEMPS RISE TO THE +6C TO +8C RANGE PRECEDING A
WEAKENING TROUGH TO THE WEST. SAID TROUGH WILL CROSS THE REGION
SATURDAY NIGHT WITH LITTLE FANFARE...EXPECT THE COOL FRONT
ASSOCIATED WITH THE TROUGH TO WASH OUT ALMOST COMPLETELY. MID AND
HIGH CLOUDS ACCOMPANYING THE TROUGH/FRONT WILL KEEP OVERNIGHT TEMPS
UP INTO THE MID TO UPPER 40S ACROSS THE FORECAST AREA. GFS HAS COME
IN LINE WITH THE LONG STANDING ECMWF CONCEPT OF HAVING VERY LOW POPS
AND QPF ASSOCIATED WITH THE FRONT...SLIGHT CHANCE ACROSS MOST OF THE
FORECAST AREA WITH LOW CHANCE POPS FOR THE SAINT LAWRENCE VALLEY AND
TUG HILL/ WESTERN ADIRONDACKS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ON SUNDAY...HIGH PRESSURE CENTERED OVER THE CENTRAL PLAINS WILL
RIDGE EASTWARD FOLLOWING THE PASSAGE OF THE DYING SURFACE TROUGH.
THE THERMAL BOUNDARY WILL REMAIN JUST SOUTH OF THE FORECAST AREA
WITH LOW CHANCE POPS ACROSS THE SOUTHERN TIER AND NIL POPS
ELSEWHERE. CLOUDS WILL LINGER ALONG THE NORTH OF THIS THERMAL
BOUNDARY WITH AFTERNOON TEMPS REACHING THE MID TO UPPER 60S.
HIGH PRESSURE FROM THE PLAINS TO THE MID GREAT LAKES AND ONWARD TO
WESTERN QUEBEC WILL HOLD A BROAD REGION OF LOW PRESSURE TO THE SOUTH
OF THE FORECAST AREA... ACROSS THE SOUTHEASTERN STATES. THE HIGH
PRESSURE SHOULD SUPPRESS ANY CHANCE OF PRECIP MONDAY THROUGH
WEDNESDAY WITH HIGH TEMPS GENERALLY IN THE MID 60S TO THE LOWER 70S.
LOWS WILL BE IN THE MID 40S TO LOW 50S.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
FOR THE REMAINDER OF THE NIGHT...MOSTLY CLOUDY AND DRY CONDITIONS
WILL CONTINUE TO BE THE GENERAL RULE. CIGS WILL GENERALLY RANGE
FROM MVFR TO LOW-END VFR...WITH MVFR CIGS TENDING TO BE MORE
COMMONPLACE ACROSS THE WESTERN SOUTHERN TIER...FINGER LAKES
REGION...AND NORTH COUNTRY.
ONCE WE GET INTO THE DAYLIGHT HOURS...CIGS WILL TEND TO LIFT BACK
TO VFR FROM WEST TO EAST WITH DIURNAL HEATING/MIXING AND THE SLOW
ENCROACHMENT OF DRIER AIR FROM THE WEST. GENERALLY DRY WEATHER
WILL ALSO CONTINUE...EXCEPT ACROSS THE NORTH COUNTRY WHERE
SCATTERED TO NUMEROUS LIGHT SHOWERS WILL LINGER CLOSER TO THE CORE
OF THE SLOWLY DEPARTING UPPER LEVEL LOW. SURFACE WINDS WILL ALSO
PICK UP WITH INCREASING HEATING OF THE FAIRLY COOL AIRMASS THAT
WILL STILL BE IN PLACE...WITH WEST-NORTHWESTERLY WINDS FREQUENTLY
GUSTING TO AROUND 25 KTS SOUTH OF LAKE ONTARIO AFTER ABOUT 14Z-
15Z.
TONIGHT...EXPECT ANY LINGERING SHOWERS ACROSS THE NORTH COUNTRY TO
WIND DOWN...WHILE CIGS CONTINUE TO IMPROVE FROM WEST TO EAST AS
HIGH PRESSURE AND DRIER AIR BUILD EAST ACROSS NEW YORK STATE.
OUTLOOK...
FRIDAY AND SATURDAY...VFR.
SUNDAY...VFR WITH A CHANCE OF SHOWERS.
MONDAY...VFR.
&&
.MARINE...
A MODEST WEST TO OCCASIONALLY NORTHWESTERLY FLOW WILL PREVAIL ACROSS
THE LOWER GREAT LAKES THROUGH FRIDAY...WITH WINDS AND WAVES EXPECTED
TO REMAIN BELOW ADVISORY CRITERIA. MINIMAL SMALL CRAFT ADVISORY
CONDITIONS NEED TO BE WATCHED ALONG THE SOUTH SHORE OF LK ONTARIO
FOR THURSDAY AFTERNOON THROUGH THURSDAY NIGHT WITH ONSHORE NW
WINDS NEAR 20 KTS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...APFFEL/JJR/SMITH
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...JJR
MARINE...APFFEL/SMITH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1249 AM EDT THU MAY 10 2012
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL DIG ACROSS THE AREA TODAY GENERATING A
FEW SHOWERS AND THUNDERSTORMS THIS AFTERNOON. HIGH PRESSURE WILL
THEN GRADUALLY BUILD ACROSS THE REGION DURING THE REMAINDER OF THE
WEEK BRINGING IMPROVING CONDITIONS ON THURSDAY AND DRY WEATHER FOR
FRIDAY AND SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1245 AM...HAVE UPDATED THE FORECAST MERELY TO KEEP IT IN
LINE WITH CURRENT OBS AND RECENT RADAR/SATELLITE
TRENDS...OTHERWISE THERE HAVE BEEN NO CHANGES TO THE PREVIOUS
FORECAST THINKING...WHICH FOLLOWS BELOW.
AN UPPER LEVEL TROF WILL VERY SLOWLY APPROACH FROM THE WEST
OVERNIGHT...EVENTUALLY SETTLING ACROSS WESTERN NEW YORK BY DAYBREAK.
DESPITE THE APPROACH OF THIS FEATURE...THE LOSS OF DAYTIME HEATING
HAS KEYED THE DEMISE OF SHOWERS ACROSS WESTERN NEW YORK.
CONSENSUS QPF OF THE NAM12/RGEM BOTH SHOW LIGHT QPF IN UPSLOPE
REGIONS...BUT LOOKING AT THE OMEGA FIELD...NEARLY ALL THE LIFT IS
GENERATED IN THE LOWEST 3000 FT. THIS WILL PROBABLY NOT BE DEEP
ENOUGH TO PRODUCE SHOWERS. THE HRRR TENDS TO SUPPORT THIS
CONCLUSION...FORECASTING MINIMAL QPF OVERNIGHT. WITH THE UPPER
TROF...AND A LIMITED CHANCE FOR DRIZZLE...WILL HANG ONTO 20 SLIGHT
CHANCE POPS...BUT OUTSIDE OF SOME LINGERING SHOWERS...EXPECT A
MAINLY DRY NIGHT. THERE IS QUITE A BIT OF CLOUD COVER ASSOCIATED
WITH THE UPPER LOW...SO THIS WILL LIMIT RADIATIONAL
COOLING...THOUGH THE NORTHERLY FLOW WILL ADVECT SLIGHTLY COLDER
TEMPERATURES IN. LOWS SHOULD MAINLY BE IN THE 40S ACROSS THE
REGION.
THURSDAY...UPPER TROUGH AXIS WILL BE LOCATED OVER WESTERN NEW YORK
SHIFTING EASTWARD AND CUTTING OFF THROUGH THE DAY. 543 DM LOW
CENTERED OVER SOUTHERN QUEBEC WILL PROVIDE COLD AIR ALOFT YIELDING
INSTABILITY CLOUDS ACROSS THE FORECAST AREA WITH A CHANCE FOR
INSTABILITY SHOWERS FOCUSED MAINLY ACROSS THE COUNTIES EAST OF LAKE
ONTARIO CLOSER TO THE UPPER LOW. MANY LOCATIONS WILL ONLY TOP OUT IN
THE MID TO UPPER 50S WITH THE CLOUD COVER AND COLD AIR ALOFT...850MB
TEMPS NEAR 0C. A FEW AREAS COULD SEE 60. BREEZY WEST TO NORTHWEST
WINDS WILL ALSO DEVELOP IN THE AFTERNOON AS THE SURFACE LOW NEAR
OTTAWA CANADA SHIFTS EAST OVER MAINE AND DEEPENS. A COOL...CLOUDY
AND BREEZY DAY TO SUM IT UP.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
A HIGH AMPLITUDE RIDGE WILL FORCE A BROAD SURFACE RIDGE INTO THE
EASTERN GREAT LAKES REGION THURSDAY NIGHT. THIS WILL BRING A
CLEARING TREND AND THE RISK FOR FROST...ESPECIALLY TO INTERIOR
SECTIONS OF THE SOUTHERN TIER WHERE TEMPERATURES WILL FALL TO THE
MID 30S IN SPOTS...POSSIBLY TO NEAR FREEZING IN THE GENESEE VALLEY.
FRIDAY SHOULD SEE PLENTY OF SUNSHINE...ALTHOUGH THERE MAY BE SOME
DIURNALLY DRIVEN CUMULUS WITH DEPARTING COLD POOL. WITH THE
ADDITIONAL SUNSHINE HIGHS WILL BE A SOLID 5 TO 10 DEGREES WARMER
THAN THURSDAY...MAINLY IN THE MID TO UPPER 60S.
SKIES WILL REMAIN CLEAR DURING FRIDAY NIGHT AND THE APPROACH OF A
WEAK COLD FRONT WILL INCREASE THE SOUTHWESTERLY BREEZE OVERNIGHT...
MIXING THE BOUNDARY LAYER AND HOLDING TEMPS LOWER TO MID 40S...
ALLEVIATING THE RISK OF FROST.
SATURDAY WILL ALSO BE A SUNNY DAY FOR THE MOST PART...SOME HIGH
CLOUDS STREAMING IN AND THICKENING THROUGH THE AFTERNOON. WILL SEE
HIGH TEMPS IN THE MID/UPR 60S EAST OF LAKE ONTARIO WITH LOWER 70S
ELSEWHERE AS 850MB TEMPS RISE TO THE +6C TO +8C RANGE PRECEDING A
WEAKENING TROUGH TO THE WEST. SAID TROUGH WILL CROSS THE REGION
SATURDAY NIGHT WITH LITTLE FANFARE...EXPECT THE COOL FRONT
ASSOCIATED WITH THE TROUGH TO WASH OUT ALMOST COMPLETELY. MID AND
HIGH CLOUDS ACCOMPANYING THE TROUGH/FRONT WILL KEEP OVERNIGHT TEMPS
UP INTO THE MID TO UPPER 40S ACROSS THE FORECAST AREA. GFS HAS COME
IN LINE WITH THE LONG STANDING ECMWF CONCEPT OF HAVING VERY LOW POPS
AND QPF ASSOCIATED WITH THE FRONT...SLIGHT CHANCE ACROSS MOST OF THE
FORECAST AREA WITH LOW CHANCE POPS FOR THE SAINT LAWRENCE VALLEY AND
TUG HILL/ WESTERN ADIRONDACKS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ON SUNDAY...HIGH PRESSURE CENTERED OVER THE CENTRAL PLAINS WILL
RIDGE EASTWARD FOLLOWING THE PASSAGE OF THE DYING SURFACE TROUGH.
THE THERMAL BOUNDARY WILL REMAIN JUST SOUTH OF THE FORECAST AREA
WITH LOW CHANCE POPS ACROSS THE SOUTHERN TIER AND NIL POPS
ELSEWHERE. CLOUDS WILL LINGER ALONG THE NORTH OF THIS THERMAL
BOUNDARY WITH AFTERNOON TEMPS REACHING THE MID TO UPPER 60S.
HIGH PRESSURE FROM THE PLAINS TO THE MID GREAT LAKES AND ONWARD TO
WESTERN QUEBEC WILL HOLD A BROAD REGION OF LOW PRESSURE TO THE SOUTH
OF THE FORECAST AREA... ACROSS THE SOUTHEASTERN STATES. THE HIGH
PRESSURE SHOULD SUPPRESS ANY CHANCE OF PRECIP MONDAY THROUGH
WEDNESDAY WITH HIGH TEMPS GENERALLY IN THE MID 60S TO THE LOWER 70S.
LOWS WILL BE IN THE MID 40S TO LOW 50S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
EXPECT THE REMAINDER OF THE OVERNIGHT PERIOD TO REMAIN DRY...WITH
LOWERING CIGS THE MAIN CONCERN. EXPECT BKN-OVC LOW CLOUDS TO
DEVELOP ACROSS THE REGION...GENERALLY HOVERING AROUND 3000 FT AT
BUF/IAG/ROC/ART...A BIT LOWER AT JHW. THE TREND SHOULD GENERALLY
BE DOWNWARD OVERNIGHT AS THE UPPER TROF APPROACHES...AND THE
INVERSION LOWERS.
THURSDAY...CIGS IMPROVE AFTER 14Z/15Z AND WIND GUSTS DEVELOP WITH
DAYTIME MIXING. BKN VFR SKIES WILL PREVAIL WITH COOL AIR ALOFT
PROVIDED BY UPPER LEVEL TROUGH OVER NY. SCATTERED SHOWERS HAVE
HIGHEST CHANCES EAST OF LAKE ONTARIO WHERE BEST INSTABILITY AND
HIGHER MOISTURE RESIDE.
OUTLOOK...
FRIDAY AND SATURDAY...VFR.
SUNDAY...VFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
A MODEST WEST TO OCCASIONALLY NORTHWESTERLY FLOW WILL PREVAIL ACROSS
THE LOWER GREAT LAKES THROUGH FRIDAY...WITH WINDS AND WAVES EXPECTED
TO REMAIN BELOW ADVISORY CRITERIA. MINIMAL SMALL CRAFT ADVISORY
CONDITIONS NEED TO BE WATCHED ALONG THE SOUTH SHORE OF LK ONTARIO
FOR THURSDAY AFTERNOON THROUGH THURSDAY NIGHT WITH ONSHORE NW
WINDS NEAR 20 KTS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...APFFEL/JJR/SMITH
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...APFFEL
MARINE...APFFEL/SMITH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
105 AM EDT THU MAY 10 2012
.SYNOPSIS...
A COLD FRONT MUCH DRIER AIR WILL OVERSPREAD THE AREA TODAY AS HIGH
PRESSURE RIDGES IN THROUGH THE UPCOMING WEEKEND. THE HIGH WILL SLIP
OFFSHORE FROM THE COAST LATE SUNDAY. A COLD FRONT WILL APPROACH THE
REGION FROM THE NORTH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 AM THURSDAY...UPDATED FORECAST TO END PRECIP AND BEGIN THE
WEST-TO-EAST CLEARING SEVERAL HOURS QUICKER THAN EARLIER FORECAST.
SKIES SHOULD BECOME CLEAR IN THE DARLINGTON AND BENNETTSVILLE
VICINITY WITHIN AN HOUR. THIS ALSO NECESSITATES A MODEST LOWERING OF
LOW TEMPERATURE FORECASTS GIVEN THE LONG PERIOD TO GO OF CLEAR SKIES
AND LIGHT WINDS INLAND. PREVIOUS DISCUSSION FOLLOWS...
LARGE AMPLIFIED UPPER TROF IN CONTROL OF THE EAST COAST THIS NEAR
TERM. AT THE SFC...A COLD FRONT ORIENTED NE-SW ACROSS THE EASTERN
CAROLINAS AT THE MOMENT...WILL TRACK EASTWARD OVERNIGHT...MOVING OFF
THE ILM CWA MAINLAND BETWEEN MIDNIGHT AND 2 AM THURSDAY. LATEST HRRR
MODEL RUNS ALSO INDICATE THE WELL DEFINED COLD FRONT TO MOVE OFF THE
CAROLINA COASTS BY EARLY THU MORNING. PROGGED SFC WIND FIELDS VIA
HRRR LOOKS LIKE THE BEST WAY TO GO. EXPECT EXCELLENT POST FRONTAL
CAA AFTER FROPA...WITH 850 TEMPS DROPPING FROM ROUGHLY 14C TO 7C AND
ALSO 1K-8H THICKNESS DROPPING FROM ROUGHLY 1396M TO 1366M BY
DAYBREAK THURSDAY. MAIN AREA OF CONVECTION VIA KLTX AND SURROUNDING
88DOS...INDICATE THE MAIN AND STRONGER AREAS OF CONVECTION LIE
ACROSS THE ADJACENT ATLANTIC WATERS. COULD OBSERVE SCATTERED -SHRA
PRIOR TO THE CFP. WILL NEED TO FURTHER ADJUST POPS ESPECIALLY WITH
THE MAIN AREA NOW OFF THE COAST. MIN TEMP GUIDANCE TRICKY DUE TO
POST FRONTAL POSSIBLE LOW STRATUS AND FOG. THE LATTER LIKELY NOT TO
OCCUR DUE TO LOW LEVEL WINDS TO INCREASE ENOUGH TO PREVENT FOG.
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...BY THURSDAY DAYBREAK THE BULK OF COLUMN
MOISTURE ASSOCIATED WITH A DEPARTING FRONTAL SYSTEM WILL RESIDE
OFFSHORE. STRONG MID AND UPPER LEVEL DRYING COUPLED WITH MODERATE
NORTH WINDS WILL ALREADY BE OVERSPREADING THE AREA. MAXIMUM TEMPS
THU MAINLY MID/UPPER 70S WITH A FEW LOCATIONS OVER THE SC INTERIOR
APT TO REACH 80. MAINLY CLEAR UNDER LOW-LEVEL NORTH WIND FLOW THU
NIGHT SHOULD YIELD LOW/MID 50S INTO EARLY FRIDAY. NORTH FLOW WILL
ENDURE MUCH OF FRIDAY DELAYING A SIGNIFICANT DAYTIME WARMING TREND
WITH MAXIMUMS VERY SIMILAR TO THURSDAY. UNDER IDEAL RADIATIONAL
COOLING...UPPER 40S INLAND LOOKS PROBABLE WITH LOWER 50S ALONG THE
COASTAL ZONES...AND SURFACE HIGH PRESSURE NEARLY OVERHEAD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...SURFACE AND UPPER RIDGE AXIS OVERHEAD SAT
WILL SHIFT OFFSHORE SUN AS BROAD 5H TROUGH STARTS TO DEVELOP OVER
THE EASTERN HALF OF THE COUNTRY. SAT INTO SUN LOOKS DRY BUT
WEAKENING INFLUENCE OF THE UPPER RIDGE AND MOISTURE RETURN IN DEEP
SOUTHWEST FLOW COULD PRODUCE SOME ISOLATED CONVECTION SUN AFTERNOON.
INHERITED SLIGHT CHANCE POP LOOKS GOOD AT THIS POINT. FOR THE
REMAINDER OF THE PERIOD WEATHER WILL REMAIN UNSETTLED WITH 5H TROUGH
AXIS TO THE WEST AND DEEP SOUTHWEST FLOW ADVECTING PLENTY OF
MOISTURE INTO THE REGION. ANY PASSING SHORTWAVE WILL ENHANCE DIURNAL
CONVECTION MON AFTERNOON WHICH WARRANTS A SMALL POP INCREASE...NOW
LOW CHANCE. TUE/WED REMAINS UNCERTAIN WITH THE 12Z GFS MUCH MORE
PROGRESSIVE THAN ITS PREVIOUS RUNS. MEDIUM RANGE GUIDANCE AGREES ON
WEAK LOW PRESSURE DEVELOPING ALONG THE GULF COAST WHICH THEN MOVES
ACROSS NORTHERN FL AND UP THE SE COAST. SIGNIFICANT TIMING
DIFFERENCES BETWEEN THE 12Z GFS...12Z CANADIAN...00Z ECMWF AND LACK
OF CONTINUITY BETWEEN THEIR RESPECTIVE RUNS IS KEEPING CONFIDENCE
LOW LATE IN THE PERIOD. THE MAIN ISSUE IS HOW THE GUIDANCE IS
HANDLING THE COLLAPSE OF THE UPPER RIDGE OUT WEST AND THE IMPACT
THIS HAS ON THE TROUGHING OVER THE EAST. WILL CONTINUE TO CARRY A
CHANCE POP TUE/TUE NIGHT WHICH WILL EXTEND INTO WED AD MUCH OF THE
GUIDANCE...SAVE THE GFS...IS SUGGESTING A SLOWER/WETTER SOLUTION.
HIGHS WILL REMAIN SLIGHTLY BELOW CLIMO THROUGH THE PERIOD WITH LOWS
STARTING OUT SLIGHTLY BELOW CLIMO BUT ENDING UP NEAR TO SLIGHTLY
ABOVE CLIMO.
&&
.AVIATION /06Z THURSDAY THROUGH TUESDAY/...
AS OF 06Z...SFC COLD FRONT IS NOW OFFSHORE AND DRIER AIR IS PUNCHING
IN FROM THE WEST AT THE SURFACE AND ALOFT...EXPECTED TO REACH THE
COAST WITHIN THE NEXT FEW HOURS. NW SFC WINDS 5-10 KT WILL INCR TO
10-15 KT AFTER DAYBREAK AS A LITTLE STRONGER FLOW MIXES DOWN FROM
ALOFT. ONCE THE CURRENT MID-LEVEL CLOUDINESS CLEARS OFFSHORE WE ARE
ONLY EXPECTING A FEW HIGH-BASED CU AT THE TOP OF THE DEEP DAYTIME
MIXED LATER TODAY. SKC EXPECTED TONIGHT.
EXTENDED OUTLOOK...ISOLATED CONVECTION LATE FRIDAY EVENING...
BECOMING SCATTERED TO NUMEROUS SATURDAY. ISOLATED CONVECTION
POSSIBLE SUNDAY. VFR MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 AM THURSDAY...TEMPERED WIND SPEED FORECASTS JUST A HAIR
BUT WITH LITTLE REAL CHANGE FROM THE PREVIOUS FORECASTS. BIGGEST
CHANGE WAS TO BRING SEAS AT THE BEACHES UP TO 1-2 FT DESPITE THE
OFFSHORE WIND. PREVIOUS DISCUSSION FOLLOWS.
FOLLOWING THE HRRR MODEL SFC WIND FIELDS. A PRONOUNCED WIND SHIFT
WILL OCCUR...WITH SW 10 TO OCCASIONALLY 15 KT...VEERING TO THE NW 15
TO 20 KT OVERNIGHT. THE LATTER MAY BE A BIT UNDERDONE GIVEN THE
TIGHTENED POST FRONTAL SFC PRESSURE GRADIENT AND COOL/COLD SURGE
RESULTING WITH HIGH. SIG SEAS WILL RUN BASICALLY 2 TO 4 FT.
INITIALLY THE EASTERLY 2 TO 3 FT GROUND SWELL WILL DOMINATE SIG
SEAS. IT WILL GIVE WAY TO AN INCREASING SHORT PERIOD LOCALLY
PRODUCED WIND WAVES EXHIBITING 3 TO 5 SECOND PERIODS. THIS WIND
DRIVEN VARIETY WILL BECOME THE DOMINATE PLAYER WITH REGARD TO SIG.
SEAS LATE TONIGHT.
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 PM WEDNESDAY...A COLD FRONT MAY BRING LIMITED VISIBILITIES
IN RAIN AND ISOLATED TSTMS...ALONG WITH LOCALLY GUSTY WINDS AND
LOCALLY HIGHER WIND-WAVES TONIGHT. MARINERS SHOULD CONSULT RADAR
BEFORE HEADING OUT LATE THIS AFTERNOON OR EVENING. THE FRONT WILL
BRING A WIND-SHIFT IN THE VERY LATE EVENING AROUND MIDNIGHT. THIS
COULD BRING N WIND GUSTS TO 20 KT THROUGH THURSDAY MORNING...BEFORE
EASING IN THE AFTERNOON. REINFORCING HIGH PRESSURE WILL SUSTAIN N
WINDS THROUGH MOST OF FRIDAY...WITH THE HIGH MOVING OVERHEAD FRIDAY
NIGHT. SEAS MAY APPROACH 5 FEET ACROSS THE OUTER PORTION AND THE
NORTH END OF FRYING PAN SHOALS THURSDAY MORNING.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY...WEAK GRADIENT SAT INTO SUN WILL KEEP WINDS
LIGHT AND HIGHLY VARIABLE. THERE WILL BE A GENERAL NORTHEAST TO
EAST FLOW WITH SPEEDS 10 KT OR LESS. GRADIENT BECOMES A LITTLE
MORE DEFINED SUN AS HIGH MOVES FARTHER OF THE COAST AND SOUTHEAST
FLOW DEVELOPS. SOME GUIDANCE HINTING AT WEAK COASTAL TROUGH ALONG
THE GA/SOUTHERN SC COAST WHICH MAY ENHANCE FLOW ACROSS SC ZONES.
HOWEVER SPEEDS SHOULD REMAIN UNDER 15 KT INTO MON. SURFACE HIGH
EAST OF THE WATERS AND LACK OF ANY SIGNIFICANT SURFACE FEATURES TO
THE WEST MEANS SOUTHEAST FLOW WILL CONTINUE ON MON. OVERALL LITTLE
CHANGE TO THE SURFACE GRADIENT BETWEEN SUN AND MON SO SPEEDS
SHOULD BE SIMILAR...10 TO 15 KT. SEAS WILL RUN 2 TO 4 FT THROUGH
THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MJC
LONG TERM...III
AVIATION...TRA
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1227 PM CDT THU MAY 10 2012
.AVIATION...
MVFR TO OCCASIONAL IFR CONDITIONS WILL CONTINUE AT KLBB WITH
PERIODS OF LIGHT TO MODERATE RAINFALL. THERE MAY BE A LIGHTNING
STRIKE OR TWO AS WELL IN THE STRONGER ACTIVITY. CONFIDENCE IS TOO
LOW TO GO PREVAILING AT THIS TIME BECAUSE RAINFALL COVERAGE HAS
STRUGGLED TO MAKE IT TO THE KLBB TERMINAL. ALSO MAY SEE
PRECIPITATION LINGER THROUGH THE OVERNIGHT HOURS AND MVFR TO IFR
CONDITIONS CONTINUE AS WELL. KCDS SHOULD REMAIN FAR ENOUGH NORTH
TO STAY VFR THROUGH THIS TAF CYCLE.
JORDAN
&&
.PREV DISCUSSION... /ISSUED 638 AM CDT THU MAY 10 2012/
AVIATION...
DIFFICULT TAF FOR KLBB TODAY/TONIGHT AS THE TERMINAL MAY BE IMPACTED BY
ONE OR MORE ROUNDS OF SHRA AND/OR TSRA...BUT CONFIDENCE IN
OCCURANCE AND TIMING IS LOW. WILL INCLUDE A TEMPO FOR -TSRA THIS
MORNING BUT LEAVE THE REMAINDER OF THE PERIOD VFR FOR NOW. MVFR
CEILINGS ARE ALSO POSSIBLE LATE TONIGHT. KCDS SHOULD BE VFR UNTIL
POSSIBLY LATER THIS EVENING WHEN SHRA/TSRA COULD APPROACH THAT
TERMINAL AS WELL.
PREV DISCUSSION... /ISSUED 529 AM CDT THU MAY 10 2012/
UPDATE...
A BROAD AREA OF SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY
RAINFALL RATES...ARE MOVING NORTH ACROSS THE WRN PERMIAN BASIN.
THE LATEST HRRR SUGGESTS THIS ACTIVITY WILL PINWHEEL NORTHWESTWARD
AROUND THE BROAD CYCLONIC CIRCULATION OF THE UPPER-LOW. THIS
SHOULD BRING THE ACTIVITY SQUARELY ACROSS COCHRAN...YOAKUM AND
TERRY COUNTIES...WITH A MORE GLANCING BLOW TO LUBBOCK...LYNN AND
HOCKLEY...AND POSSIBLY BAILEY COUNTIES. WE HAVE UPPED POPS AND QPF
FOR THESE AREAS. QUICK RAINFALL OF AN INCH OR SO IS POSSIBLE
ACROSS YOAKUM AND SRN TERRY COUNTIES AND COULD CAUSE SOME MINOR
FLOODING ISSUES.
PREV DISCUSSION... /ISSUED 334 AM CDT THU MAY 10 2012/
SHORT TERM...
THE UPPER-LOW AS SEEN IN SAT. IMAGERY IS MOVING SLOWLY EAST ACROSS
NRN MEXICO THIS MORNING. A BROAD AREA OF LIFT ON THE NORTHERN AND
EASTERN FLANKS OF THE LOW IS SUPPORTING SCATTERED TSTM ACTIVITY
WHICH AT 230 AM WAS CONCENTRATED ACROSS THE TRANS-PECOS AND WESTERN
PERMIAN BASIN...WHICH APPEARS TO BE ENHANCED BY MOISTURE
ADVECTION/LIFT ON A 20 KT SRLY LLJ. MOST MODEL OUTPUT DOES NOT HAVE
A GREAT HANDLE ON THE LOCATION AND EXTENT OF THE CURRENT
ACTIVITY...WHICH IS ALREADY MOVING INTO GAINES COUNTY...AND APPEARS
LIKELY TO MOVE INTO YOAKUM AND POSSIBLY TERRY COUNTIES SHORTLY AFTER
3 AM. THE MAIN FORECAST PROBLEM FOR TODAY WILL BE COVERAGE...TIMING
AND INTENSITY OF PRECIP WITH THIS SYSTEM AS IT MOVES OVER SW TX THIS
AFTN...AND THEN SWINGS NEWD INTO CENTRAL TX THIS EVENING.
OVERALL...THE TRACK FAVORS OUR SW ZONES WITH THE HIGHEST POPS THIS
MORNING....SRN AREAS THIS AFTERNOON...AND THEN EASTERN AREAS THIS
EVENING. THERE MAY BE A FAIRLY ABRUPT CUTOFF TO THE PRECIP SOMEWHERE
ACROSS THE CENTRAL OR NORTHERN ZONES...BUT WE HAVE KEPT A SLIGHT
CHANCE GOING ACROSS MOST OF THE FAR SRN PANHANDLE THIS AFTN AND EVE
BECAUSE IT IS DIFFICULT TO DETERMINE JUST WHERE THAT CUTOFF MAY LIE.
PROGS OF CAPE GENERALLY SHOW SOMEWHERE BETWEEN 400-800 J/KG MAY BE
PRESENT ACROSS THE THE AREA TODAY...WHEN COUPLED WITH WEAK
DEEP-LAYER SHEAR THIS SHOULD BE SUFFICIENT FOR EMBEDDED TSTMS IN THE
SHOWER ACTIVITY BUT LIKELY KEEP THE SVR POTENTIAL VERY LOW. RAINFALL
AMOUNTS ARE LIKELY TO BE MAXIMIZED ACROSS THE SRN ZONES. FORECAST
PWATS CLIMB TO ABOUT 1.25 INCHES ACROSS THE ROLLING PLAINS THIS
EVENING AND WITH THE CYCLONIC FLOW FEEDING DEEPER MOISTURE INTO THAT
AREA AN INCH OR SO OF RAINFALL IS POSSIBLE. OVERALL...IT APPEARS
THAT THE THREAT OF EXCESSIVE RAINFALL WILL REMAIN WELL OFF TO OUR
SOUTHEAST HOWEVER SOME LOCALLY HEAVIER AMOUNTS COULD CAUSE SOME
MINOR FLOODING ISSUES...WITH THE AREAS OF CONCERN MAINLY SRN YOAKUM
AND TERRY COUNTIES THIS MORNING /WHERE THEY SAW POCKETS OF HEAVY
RAINFALL MONDAY/ AND THEN THE SRN ROLLING PLAINS THIS EVENING. WITH
MORE EXTENSIVE CLOUD COVER ACROSS THE WEST AND SOUTH...WE EXPECT
TEMPS TODAY TO BE SOMEWHAT COOLER THAN YESTERDAY...RANGING FROM
HIGHS NEAR 70F IN THE SOUTHWEST TO LOWER 80S IN THE NE.
LONG TERM...
ADDITIONAL CHANCES FOR MEASURABLE RAINFALL WILL BE COMING UP IN
THE LONG TERM FORECAST.
PRECIPITATION WILL CONTINUE THROUGH THE DAY ON FRIDAY. AN AREA OF
DEFORMATION WILL MOVE OVER THE AREA ON THE NORTH AND WEST SIDE OF
THE SLOW MOVING UPPER LEVEL LOW. THE LOW WILL TRACK OVER THE
SOUTHERN ROLLING PLAINS DURING THE DAY ON FRIDAY. THE NAM/SREF
SOLUTIONS STILL TAKE THE LOW FARTHER SOUTH ON FRIDAY AND SATURDAY THAN
ALL OTHER MODEL SOLUTIONS. HEAVY RAIN WILL LIKELY BE A RESULT OF
THIS SLOW MOVING UPPER LOW. UNFORTUNATELY...MOST OF THIS HEAVY
RAIN WILL BE SOUTH OF THE AREA. PRECIPITATION PROCESSES ARE
EXPECTED TO BE VERY EFFICIENT WITH NEARLY SATURATED
SOUNDINGS...ESPECIALLY OFF THE CAPROCK. BEST CHANCES FOR THE FA
WILL BE OVER THE SOUTHERN ROLLING PLAINS.
A FRONT WILL THEN BACK DOOR INTO THE AREA SATURDAY SETTING UP
MOIST UPSLOPE FLOW THROUGH AT LEAST EARLY NEXT WEEK. THE AXIS OF A
SHARP UPPER LEVEL WAVE WILL MOVE SOUTH THROUGH THE ROCKIES FROM
SUNDAY THROUGH MONDAY. THIS WILL BE OUR NEXT SHOT AT PRECIPITATION
WITH NORTHWEST FLOW STORMS DEVELOPING EACH EVENING. THE BEST
CHANCES AT THE MOMENT APPEAR TO BE ON SUNDAY AND MONDAY EVENING
WHEN UPPER LEVEL LIFT WILL BE IN THE AREA. SATURDAY WILL SEE LESS
OF A CHANCE OF PRECIPITATION WITH UPPER LEVEL LIFT LACKING. HAVE
SIDED MORE WITH THE ECMWF SOLUTION GIVEN ITS CONSISTENT MODEL RUNS
OPPOSED TO THE GFS. ADDITIONALLY...THE GFS APPEARS TO BE SUFFERING
FROM SEVERE CONVECTIVE FEEDBACK DURING THIS TIME PERIOD.
FURTHERMORE...A QUICK GLANCE AT ANALOG GUIDANCE SHOWS HIGH
PROBABILITIES FOR SEVERE WEATHER WITH THIS NEXT SHOT OF
THUNDERSTORMS. JDV
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 75 49 70 49 70 / 20 20 20 10 10
TULIA 77 52 68 50 72 / 20 20 30 10 10
PLAINVIEW 75 52 67 50 72 / 20 20 30 10 10
LEVELLAND 71 51 72 53 75 / 50 30 30 10 10
LUBBOCK 73 52 70 51 74 / 40 30 40 10 10
DENVER CITY 69 51 75 53 75 / 90 30 30 10 10
BROWNFIELD 70 52 73 54 76 / 90 30 30 10 10
CHILDRESS 81 57 68 56 75 / 10 30 40 10 10
SPUR 75 54 69 53 76 / 30 40 50 10 10
ASPERMONT 76 56 72 57 76 / 30 60 60 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/99
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1043 AM CDT THU MAY 10 2012
.UPDATE...
MORNING FORECAST UPDATE.
&&
.DISCUSSION...
UPPER LOW CONTINUES TO CHURN AWAY IN THE S ROCKIES NEAR EL PASO
THIS MORNING AND GETTING DEEP CONVECTION ALL THROUGH THE NORTHERN
PORTIONS OF THE RIO GRANDE VALLEY INTO W TX. WEAK SFC LOW WAS
LOCATED OVER THE EDWARDS PLATEAU WITH A WARM FRONT STRETCHING FROM
NEAR JUNCTION TO GALVESTON THIS MORNING. WARM FRONT SHOULD SLOWLY
MOVE NORTHWARD THIS AFTERNOON SO INCREASED POPS A TOUCH FOR ISO
ACTIVITY ALONG THE WARM FRONT. THINK INITIAL CONVECTIVE ACTIVITY
WILL APPROACH WESTERN PORTIONS OF SE TX INTO THE BRAZOS VALLEY
LATE THIS AFTERNOON AND EVENING. THE MAIN SHOW LOOKS TO BE ON
TRACK FOR LATE TONIGHT FRI MORNING AS EXPECTING ORGANIZED
CONVECTION TO MOVE INTO THE AREA BY 12Z FRI. FLASH FLOOD THREAT
WILL BE MARGINAL FOR MUCH OF THE AREA BUT STILL CONCERNED FOR
AREAS MAINLY SOUTH OF A BRENHAM...THE WOODLANDS...BEAUMONT LINE.
THINK THIS WILL BE THE AREA FOR HIGHEST QPF ALTHOUGH AREAS NORTH
OF THAT LINE MAY STILL HAVE SIGNIFICANT RAINFALL BUT HAVE NOT HAD
MUCH IN THE WAY OF RECENT RAINFALL. WILL CONTINUE TO EVALUATE 12Z
MODEL GUIDANCE AND LOOK FOR POSSIBILITY OF FLASH FLOOD WATCH
LATER THIS AFTERNOON.
39
&&
.PREV DISCUSSION... /ISSUED 712 AM CDT THU MAY 10 2012/
DISCUSSION...
SEE AVIATION SECTION BELOW. CORRECTION FOR SOME SPELLING.
AVIATION...
MESSY GUIDANCE FOR TSRA CHANCES ACROSS AREA TAF SITES TODAY. LOTS
OF CLR TO SCT SKIES. OCNL VFR BKN DECKS AT KCLL THIS MORNING BUT
MVFR NOT EXPECTED TIL EVENING. HRRR FCST PCPN FIELDS HAD BEEN
BRING PCPN INTO METRO TAFS BY MID MORNING BUT NEWER RUNS SEEM TO
BE SLOWING DOWN WHICH IS MORE IN AGREEMENT WITH LARGER SCALE GFS
GUIDANCE AND MOS OUTPUT. THERE IS AN ADDITIONAL BOUNDARY VISIBLE
IN 3.9UM IMAGERY MOVING SOUTHWESTWARD FROM NEAR KLBX TO OFFSHORE
PLATFORM KHQI THIS MORNING. WRF AND HRRR RUNS SEEM TO DEVELOP
ADDITIONAL CONVECTION ALONG THIS BOUNDARY THIS MORNING AS WELL.
PROBLEM IS THAT 00Z NAM/GFS SOUNDINGS AGAIN HAD SKINNY CAPE. SORT OF
COMPROMISED ON TAFS WITH VCSH BEGINNING 15Z AT METRO SITES AND VCTS
MOST SITES THIS AFTERNOON. CONFIDENCE IN THIS SET OF TAFS IS LOWER
THAN AVERAGE DUE TO TIMING/OCCURRENCE OF CONVECTION ANDGUIDANCE
DISAGREEMENTS. MAY BE OVERUSING VCTS TODAY AND THIS EVENING BUT
LATER UPDATES CAN FINE TUNE THIS. ANOTHER ROUND OF TSRA EXPECTED
OVERNIGHT AND TRIED TO TIME THIS WITH 5KM WRF ANDARW OUTPUT THAT WE
LIKED...MORE CONFIDENT ON TSRAOCCURRENCE/TIMING OVERNIGHT. 04
PREV DISCUSSION... /ISSUED 541 AM CDT THU MAY 10 2012/
.LOCALLY HEAVY RAINFALL POSSIBLE TONIGHT AND FRIDAY...
DISCUSSION...
THE UPPER LOW CURRENTLY APPROACHING THE EL PASO AREA WILL MOVE
ACROSS THE STATE LATER TODAY AND FRIDAY. SE TX WILL BE UNDER A
FAVORABLE AREA FOR WIDESPREAD SHOWERS AND THUNDERSTORMS BY LATE
TONIGHT THROUGH FRIDAY. FOR THE RAINFALL POTENTIAL...LIKED THE
HIGH RESOLUTION ARW FOR TODAY AND THIS EVENING AND THE GFS
ENSEMBLE QPF OVERNIGHT TONIGHT THROUGH FRIDAY EVENING. THE GFS
THEN LOOKED REASONABLE FOR THE REMAINDER OF THE FORECAST.
FOR TODAY THE MAIN ITEM OF CONCERN WILL BE A POSSIBLE SQUALL LINE
THIS AFTERNOON. EARLY THIS MORNING...FAIRLY DRY AIR WAS IN PLACE
OVER THE NORTHERN HALF OF SE TX WHERE DEWPOINTS WERE IN THE 50S.
THIS FACT INDICATES THAT RAINFALL WILL LIKELY HOLD OFF UNTIL THIS
AFTERNOON OVER THE SOUTHERN-MOST AREAS. THE MODEL FORECAST
SOUNDINGS HAVE A SKINNY TYPE CAPE PROFILE. THE ARW MODEL SHOWS
SQUALL LINE MOVING INTO THE SOUTHWESTERN COUNTIES EARLY THIS
AFTERNOON. THESE SHOULD REACH THE CENTRAL COUNTIES AND
NORTHEASTERN COUNTIES DURING THE LATE AFTERNOON. WITH THE DRY AIR
IN THE MID LEVELS ON THE FORECAST SOUNDINGS...THE POTENTIAL FOR
STRONG OR SEVERE WILL BE MAINLY STRONG WINDS.
THE MAIN CONCERN THEN WILL BE THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL TONIGHT AND FRIDAY. THE ECMWF DOES DIFFER FROM THE GFS...
HOWEVER THE GFS DOES LOOK MORE REASONABLE GIVEN THE MOVEMENT OF
THE UPPER LOW AND ITS DEVELOPMENT OF A COASTAL SURFACE TROUGH. AS
THE UPPER LOW MOVES INTO THE NORTH CENTRAL PORTION OF THE STATE
OVERNIGHT TONIGHT...MORE WIDESPREAD STORMS ARE LIKELY TO
OVERSPREAD THE WESTERN COUNTIES OF THE FORECAST AREA. RAINFALL
AND THUNDERSTORMS WILL BE WIDESPREAD ON FRIDAY AND END FRIDAY
NIGHT AND EARLY SATURDAY. THE LATEST HPC QPF LOOKS REASONABLE IN
PLACING TOTAL RAINFALL AMOUNTS FOR TONIGHT THROUGH EARLY SATURDAY
IN THE 1 TO 3 INCH RANGE. ISOLATED TOTALS OF 3 TO 5 INCHES IS
POSSIBLE.
THE FLASH FLOOD GUIDANCE IS SHOWING 6-HOUR FLASH FLOOD AMOUNTS OF
4 TO 6 INCHES. THERE WERE POCKETS OF 3 TO 5 INCHES OVER THE
COASTAL AREAS WEST OF GALVESTON BAY AND ACROSS GRIMES COUNTY.
HOWEVER...BECAUSE THE POTENTIAL FOR THE HEAVIEST RAINFALL IS ON
FRIDAY AND GIVEN THE HIGH FLASH FLOOD GUIDANCE...DECIDED TO HOLD
OFF ON A FLOOD WATCH FOR NOW. HOWEVER...ANY LOCATION WITH POOR
DRAINAGE THAT DOES RECEIVE RAINFALL APPROACHING 2 TO 3 INCHES IN
A 1 TO 2 HOUR PERIOD MAY EXPERIENCE MINOR FLOODING...ESPECIALLY
AREAS IN URBAN LOCATIONS. WILL RECONSIDER THE POTENTIAL FOR
FLOODING LATER TODAY.
40
MARINE...
EASTERLY WINDS HAVE BEGUN ONSHORE FLOW AND WILL SLOWLY VEER TODAY
AND TONIGHT. AS UPPER LOW APPROACHES FROM THE WEST PRESSURE
GRADIENT BEGINS TO TIGHT AND WINDS FRESHEN UP...RESULTS IN A SCEC
BEGINNING 18Z THIS AFTERNOON THROUGH 18Z FRIDAY FOR 15-20KT WINDS
AND GRADUALLY RISING SIG WAVE HGTS. GFS NO LONGER GENERATES NEAR
GALE FORCE WINDS AS IT DID ON PREVIOUS 00Z RUN AND IS MORE IN LINE
WITH THE REST OF THE GUIDANCE. GENERALLY WENT WITH GFS/ECMWF BLEND
THROUGH 18Z FRIDAY THEN MOSTLY GFS AFTER THAT. DROPPED SIG WAVE
HEIGHTS DOWN TO MAX 6 FEET FRIDAY MORNING PER WW3 AND SWAN
OUTPUT...NOT SURPRISING GIVEN REDUCTION IN GFS WINDS IN RECENT
MODEL RUNS. AFTER THIS MESS OF SHRA/TSRA PASSES THROUGH FRI-SAT
LIGHT TO MODERATE OFFSHORE FLOW RETURNS AND LASTS FOR A FEW DAYS.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 83 64 78 62 78 / 30 80 80 50 40
HOUSTON (IAH) 85 65 78 64 81 / 20 70 80 60 40
GALVESTON (GLS) 83 70 78 70 80 / 20 60 80 60 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH FRIDAY AFTERNOON FOR
THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
712 AM CDT THU MAY 10 2012
.DISCUSSION...
SEE AVIATION SECTION BELOW. CORRECTION FOR SOME SPELLING.
&&
.AVIATION...
MESSY GUIDANCE FOR TSRA CHANCES ACROSS AREA TAF SITES TODAY. LOTS
OF CLR TO SCT SKIES. OCNL VFR BKN DECKS AT KCLL THIS MORNING BUT
MVFR NOT EXPECTED TIL EVENING. HRRR FCST PCPN FIELDS HAD BEEN
BRING PCPN INTO METRO TAFS BY MID MORNING BUT NEWER RUNS SEEM TO
BE SLOWING DOWN WHICH IS MORE IN AGREEMENT WITH LARGER SCALE GFS
GUIDANCE AND MOS OUTPUT. THERE IS AN ADDITIONAL BOUNDARY VISIBLE
IN 3.9UM IMAGERY MOVING SOUTHWESTWARD FROM NEAR KLBX TO OFFSHORE
PLATFORM KHQI THIS MORNING. WRF AND HRRR RUNS SEEM TO DEVELOP
ADDITIONAL CONVECTION ALONG THIS BOUNDARY THIS MORNING AS WELL.
PROBLEM IS THAT 00Z NAM/GFS SOUNDINGS AGAIN HAD SKINNY CAPE. SORT OF
COMPROMISED ON TAFS WITH VCSH BEGINNING 15Z AT METRO SITES AND VCTS
MOST SITES THIS AFTERNOON. CONFIDENCE IN THIS SET OF TAFS IS LOWER
THAN AVERAGE DUE TO TIMING/OCCURRENCE OF CONVECTION ANDGUIDANCE
DISAGREEMENTS. MAY BE OVERUSING VCTS TODAY AND THIS EVENING BUT
LATER UPDATES CAN FINE TUNE THIS. ANOTHER ROUND OF TSRA EXPECTED
OVERNIGHT AND TRIED TO TIME THIS WITH 5KM WRF ANDARW OUTPUT THAT WE
LIKED...MORE CONFIDENT ON TSRAOCCURRENCE/TIMING OVERNIGHT. 04
&&
.PREV DISCUSSION... /ISSUED 541 AM CDT THU MAY 10 2012/
..LOCALLY HEAVY RAINFALL POSSIBLE TONIGHT AND FRIDAY...
DISCUSSION...
THE UPPER LOW CURRENTLY APPROACHING THE EL PASO AREA WILL MOVE
ACROSS THE STATE LATER TODAY AND FRIDAY. SE TX WILL BE UNDER A
FAVORABLE AREA FOR WIDESPREAD SHOWERS AND THUNDERSTORMS BY LATE
TONIGHT THROUGH FRIDAY. FOR THE RAINFALL POTENTIAL...LIKED THE
HIGH RESOLUTION ARW FOR TODAY AND THIS EVENING AND THE GFS
ENSEMBLE QPF OVERNIGHT TONIGHT THROUGH FRIDAY EVENING. THE GFS
THEN LOOKED REASONABLE FOR THE REMAINDER OF THE FORECAST.
FOR TODAY THE MAIN ITEM OF CONCERN WILL BE A POSSIBLE SQUALL LINE
THIS AFTERNOON. EARLY THIS MORNING...FAIRLY DRY AIR WAS IN PLACE
OVER THE NORTHERN HALF OF SE TX WHERE DEWPOINTS WERE IN THE 50S.
THIS FACT INDICATES THAT RAINFALL WILL LIKELY HOLD OFF UNTIL THIS
AFTERNOON OVER THE SOUTHERN-MOST AREAS. THE MODEL FORECAST
SOUNDINGS HAVE A SKINNY TYPE CAPE PROFILE. THE ARW MODEL SHOWS
SQUALL LINE MOVING INTO THE SOUTHWESTERN COUNTIES EARLY THIS
AFTERNOON. THESE SHOULD REACH THE CENTRAL COUNTIES AND
NORTHEASTERN COUNTIES DURING THE LATE AFTERNOON. WITH THE DRY AIR
IN THE MID LEVELS ON THE FORECAST SOUNDINGS...THE POTENTIAL FOR
STRONG OR SEVERE WILL BE MAINLY STRONG WINDS.
THE MAIN CONCERN THEN WILL BE THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL TONIGHT AND FRIDAY. THE ECMWF DOES DIFFER FROM THE GFS...
HOWEVER THE GFS DOES LOOK MORE REASONABLE GIVEN THE MOVEMENT OF
THE UPPER LOW AND ITS DEVELOPMENT OF A COASTAL SURFACE TROUGH. AS
THE UPPER LOW MOVES INTO THE NORTH CENTRAL PORTION OF THE STATE
OVERNIGHT TONIGHT...MORE WIDESPREAD STORMS ARE LIKELY TO
OVERSPREAD THE WESTERN COUNTIES OF THE FORECAST AREA. RAINFALL
AND THUNDERSTORMS WILL BE WIDESPREAD ON FRIDAY AND END FRIDAY
NIGHT AND EARLY SATURDAY. THE LATEST HPC QPF LOOKS REASONABLE IN
PLACING TOTAL RAINFALL AMOUNTS FOR TONIGHT THROUGH EARLY SATURDAY
IN THE 1 TO 3 INCH RANGE. ISOLATED TOTALS OF 3 TO 5 INCHES IS
POSSIBLE.
THE FLASH FLOOD GUIDANCE IS SHOWING 6-HOUR FLASH FLOOD AMOUNTS OF
4 TO 6 INCHES. THERE WERE POCKETS OF 3 TO 5 INCHES OVER THE
COASTAL AREAS WEST OF GALVESTON BAY AND ACROSS GRIMES COUNTY.
HOWEVER...BECAUSE THE POTENTIAL FOR THE HEAVIEST RAINFALL IS ON
FRIDAY AND GIVEN THE HIGH FLASH FLOOD GUIDANCE...DECIDED TO HOLD
OFF ON A FLOOD WATCH FOR NOW. HOWEVER...ANY LOCATION WITH POOR
DRAINAGE THAT DOES RECEIVE RAINFALL APPROACHING 2 TO 3 INCHES IN
A 1 TO 2 HOUR PERIOD MAY EXPERIENCE MINOR FLOODING...ESPECIALLY
AREAS IN URBAN LOCATIONS. WILL RECONSIDER THE POTENTIAL FOR
FLOODING LATER TODAY.
40
MARINE...
EASTERLY WINDS HAVE BEGUN ONSHORE FLOW AND WILL SLOWLY VEER TODAY
AND TONIGHT. AS UPPER LOW APPROACHES FROM THE WEST PRESSURE
GRADIENT BEGINS TO TIGHT AND WINDS FRESHEN UP...RESULTS IN A SCEC
BEGINNING 18Z THIS AFTERNOON THROUGH 18Z FRIDAY FOR 15-20KT WINDS
AND GRADUALLY RISING SIG WAVE HGTS. GFS NO LONGER GENERATES NEAR
GALE FORCE WINDS AS IT DID ON PREVIOUS 00Z RUN AND IS MORE IN LINE
WITH THE REST OF THE GUIDANCE. GENERALLY WENT WITH GFS/ECMWF BLEND
THROUGH 18Z FRIDAY THEN MOSTLY GFS AFTER THAT. DROPPED SIG WAVE
HEIGHTS DOWN TO MAX 6 FEET FRIDAY MORNING PER WW3 AND SWAN
OUTPUT...NOT SURPRISING GIVEN REDUCTION IN GFS WINDS IN RECENT
MODEL RUNS. AFTER THIS MESS OF SHRA/TSRA PASSES THROUGH FRI-SAT
LIGHT TO MODERATE OFFSHORE FLOW RETURNS AND LASTS FOR A FEW DAYS.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 83 64 78 62 78 / 30 80 80 50 40
HOUSTON (IAH) 85 65 78 64 81 / 20 70 80 60 40
GALVESTON (GLS) 83 70 78 70 80 / 20 60 80 60 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION FROM 1 PM CDT THIS AFTERNOON
THROUGH FRIDAY AFTERNOON FOR THE FOLLOWING ZONES: WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...04
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
704 AM CDT THU MAY 10 2012
.DISCUSSION...
SEE AVIATION SECTION BELOW.
&&
.AVIATION...
MESSY GUIDANCE FOR TSRA CHANCES ACROSS AREA TAF SITES TODAY. LOTS
OF CLR TO SCT SKIES. OCNL VFR BKN DECKS AT KCLL THIS MORNING BUT
MVFR NOT EXPECTED TIL EVENING. HRRR FCST PCPN FIELDS HAD BEEN
BRING PCPN INTO METRO TAFS BY MID MORNING BUT NEWER RUNS SEEM TO
BE SLOWING DOWN WHICH IS MORE IN AGREEMENT WITH LARGER SCALE GFS
GUIDANCE AND MOS OUTPUT. THERE IS AN ADDITIONAL BOUNDARY VISIBLE
IN 3.9UM IMAGERY MOVING SOUTHWESTWARD FROM NEAR KLBX TO OFFSHORE
PLATFORM KHQI THIS MORNING. WRF AND HRRR RUNS SEEM TO DEVELOP
ADDITIONAL CONVECTION ALONG THIS BOUNDARY THIS MORNING AS WELL.
PROBABLY IS THAT 00Z NAM/GFS SOUNDINGS AGAIN HAD SKINNY CAPE. SORT
OF COMPROMISED ON TAFS WITH VCSH BEGINNING 15Z AT METRO SITES AND
VCTS MOST SITES THIS AFTERNOON. CONFIDENCE IN THIS SET OF TAFS IS
LOWER THAN AVERAGE DUE TO TIMING/OCCURRENCE OF CONVECTION AND
GUIDANCE DISAGREEMENTS. MAY BE OVERUSING VCTS TODAY AND THIS
EVENIGN BUT LATER UPDATES CAN FINE TUNE THIS. ANOTHER ROUND OF
TSRA EXPECTED OVERNIGHT AND TRIED TO TIME THIS WITH 5KM WRF AND
ARW OUTPUT THAT WE LIKED...MORE CONFIDENT ON TSRA
OCCURRENCE/TIMING OVERNIGHT. 04
&&
.PREV DISCUSSION... /ISSUED 541 AM CDT THU MAY 10 2012/
..LOCALLY HEAVY RAINFALL POSSIBLE TONIGHT AND FRIDAY...
DISCUSSION...
THE UPPER LOW CURRENTLY APPROACHING THE EL PASO AREA WILL MOVE
ACROSS THE STATE LATER TODAY AND FRIDAY. SE TX WILL BE UNDER A
FAVORABLE AREA FOR WIDESPREAD SHOWERS AND THUNDERSTORMS BY LATE
TONIGHT THROUGH FRIDAY. FOR THE RAINFALL POTENTIAL...LIKED THE
HIGH RESOLUTION ARW FOR TODAY AND THIS EVENING AND THE GFS
ENSEMBLE QPF OVERNIGHT TONIGHT THROUGH FRIDAY EVENING. THE GFS
THEN LOOKED REASONABLE FOR THE REMAINDER OF THE FORECAST.
FOR TODAY THE MAIN ITEM OF CONCERN WILL BE A POSSIBLE SQUALL LINE
THIS AFTERNOON. EARLY THIS MORNING...FAIRLY DRY AIR WAS IN PLACE
OVER THE NORTHERN HALF OF SE TX WHERE DEWPOINTS WERE IN THE 50S.
THIS FACT INDICATES THAT RAINFALL WILL LIKELY HOLD OFF UNTIL THIS
AFTERNOON OVER THE SOUTHERN-MOST AREAS. THE MODEL FORECAST
SOUNDINGS HAVE A SKINNY TYPE CAPE PROFILE. THE ARW MODEL SHOWS
SQUALL LINE MOVING INTO THE SOUTHWESTERN COUNTIES EARLY THIS
AFTERNOON. THESE SHOULD REACH THE CENTRAL COUNTIES AND
NORTHEASTERN COUNTIES DURING THE LATE AFTERNOON. WITH THE DRY AIR
IN THE MID LEVELS ON THE FORECAST SOUNDINGS...THE POTENTIAL FOR
STRONG OR SEVERE WILL BE MAINLY STRONG WINDS.
THE MAIN CONCERN THEN WILL BE THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL TONIGHT AND FRIDAY. THE ECMWF DOES DIFFER FROM THE GFS...
HOWEVER THE GFS DOES LOOK MORE REASONABLE GIVEN THE MOVEMENT OF
THE UPPER LOW AND ITS DEVELOPMENT OF A COASTAL SURFACE TROUGH. AS
THE UPPER LOW MOVES INTO THE NORTH CENTRAL PORTION OF THE STATE
OVERNIGHT TONIGHT...MORE WIDESPREAD STORMS ARE LIKELY TO
OVERSPREAD THE WESTERN COUNTIES OF THE FORECAST AREA. RAINFALL
AND THUNDERSTORMS WILL BE WIDESPREAD ON FRIDAY AND END FRIDAY
NIGHT AND EARLY SATURDAY. THE LATEST HPC QPF LOOKS REASONABLE IN
PLACING TOTAL RAINFALL AMOUNTS FOR TONIGHT THROUGH EARLY SATURDAY
IN THE 1 TO 3 INCH RANGE. ISOLATED TOTALS OF 3 TO 5 INCHES IS
POSSIBLE.
THE FLASH FLOOD GUIDANCE IS SHOWING 6-HOUR FLASH FLOOD AMOUNTS OF
4 TO 6 INCHES. THERE WERE POCKETS OF 3 TO 5 INCHES OVER THE
COASTAL AREAS WEST OF GALVESTON BAY AND ACROSS GRIMES COUNTY.
HOWEVER...BECAUSE THE POTENTIAL FOR THE HEAVIEST RAINFALL IS ON
FRIDAY AND GIVEN THE HIGH FLASH FLOOD GUIDANCE...DECIDED TO HOLD
OFF ON A FLOOD WATCH FOR NOW. HOWEVER...ANY LOCATION WITH POOR
DRAINAGE THAT DOES RECEIVE RAINFALL APPROACHING 2 TO 3 INCHES IN
A 1 TO 2 HOUR PERIOD MAY EXPERIENCE MINOR FLOODING...ESPECIALLY
AREAS IN URBAN LOCATIONS. WILL RECONSIDER THE POTENTIAL FOR
FLOODING LATER TODAY.
40
MARINE...
EASTERLY WINDS HAVE BEGUN ONSHORE FLOW AND WILL SLOWLY VEER TODAY
AND TONIGHT. AS UPPER LOW APPROACHES FROM THE WEST PRESSURE
GRADIENT BEGINS TO TIGHT AND WINDS FRESHEN UP...RESULTS IN A SCEC
BEGINNING 18Z THIS AFTERNOON THROUGH 18Z FRIDAY FOR 15-20KT WINDS
AND GRADUALLY RISING SIG WAVE HGTS. GFS NO LONGER GENERATES NEAR
GALE FORCE WINDS AS IT DID ON PREVIOUS 00Z RUN AND IS MORE IN LINE
WITH THE REST OF THE GUIDANCE. GENERALLY WENT WITH GFS/ECMWF BLEND
THROUGH 18Z FRIDAY THEN MOSTLY GFS AFTER THAT. DROPPED SIG WAVE
HEIGHTS DOWN TO MAX 6 FEET FRIDAY MORNING PER WW3 AND SWAN
OUTPUT...NOT SURPRISING GIVEN REDUCTION IN GFS WINDS IN RECENT
MODEL RUNS. AFTER THIS MESS OF SHRA/TSRA PASSES THROUGH FRI-SAT
LIGHT TO MODERATE OFFSHORE FLOW RETURNS AND LASTS FOR A FEW DAYS.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 83 64 78 62 78 / 30 80 80 50 40
HOUSTON (IAH) 85 65 78 64 81 / 20 70 80 60 40
GALVESTON (GLS) 83 70 78 70 80 / 20 60 80 60 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION FROM 1 PM CDT THIS AFTERNOON
THROUGH FRIDAY AFTERNOON FOR THE FOLLOWING ZONES: WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...04
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
638 AM CDT THU MAY 10 2012
.AVIATION...
DIFFICULT TAF FOR KLBB TODAY/TONIGHT AS THE TERMINAL MAY BE IMPACTED BY
ONE OR MORE ROUNDS OF SHRA AND/OR TSRA...BUT CONFIDENCE IN
OCCURANCE AND TIMING IS LOW. WILL INCLUDE A TEMPO FOR -TSRA THIS
MORNING BUT LEAVE THE REMAINDER OF THE PERIOD VFR FOR NOW. MVFR
CEILINGS ARE ALSO POSSIBLE LATE TONIGHT. KCDS SHOULD BE VFR UNTIL
POSSIBLY LATER THIS EVENING WHEN SHRA/TSRA COULD APPROACH THAT
TERMINAL AS WELL.
&&
.PREV DISCUSSION... /ISSUED 529 AM CDT THU MAY 10 2012/
UPDATE...
A BROAD AREA OF SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY
RAINFALL RATES...ARE MOVING NORTH ACROSS THE WRN PERMIAN BASIN.
THE LATEST HRRR SUGGESTS THIS ACTIVITY WILL PINWHEEL NORTHWESTWARD
AROUND THE BROAD CYCLONIC CIRCULATION OF THE UPPER-LOW. THIS
SHOULD BRING THE ACTIVITY SQUARELY ACROSS COCHRAN...YOAKUM AND
TERRY COUNTIES...WITH A MORE GLANCING BLOW TO LUBBOCK...LYNN AND
HOCKLEY...AND POSSIBLY BAILEY COUNTIES. WE HAVE UPPED POPS AND QPF
FOR THESE AREAS. QUICK RAINFALL OF AN INCH OR SO IS POSSIBLE
ACROSS YOAKUM AND SRN TERRY COUNTIES AND COULD CAUSE SOME MINOR
FLOODING ISSUES.
PREV DISCUSSION... /ISSUED 334 AM CDT THU MAY 10 2012/
SHORT TERM...
THE UPPER-LOW AS SEEN IN SAT. IMAGERY IS MOVING SLOWLY EAST ACROSS
NRN MEXICO THIS MORNING. A BROAD AREA OF LIFT ON THE NORTHERN AND
EASTERN FLANKS OF THE LOW IS SUPPORTING SCATTERED TSTM ACTIVITY
WHICH AT 230 AM WAS CONCENTRATED ACROSS THE TRANS-PECOS AND WESTERN
PERMIAN BASIN...WHICH APPEARS TO BE ENHANCED BY MOISTURE
ADVECTION/LIFT ON A 20 KT SRLY LLJ. MOST MODEL OUTPUT DOES NOT HAVE
A GREAT HANDLE ON THE LOCATION AND EXTENT OF THE CURRENT
ACTIVITY...WHICH IS ALREADY MOVING INTO GAINES COUNTY...AND APPEARS
LIKELY TO MOVE INTO YOAKUM AND POSSIBLY TERRY COUNTIES SHORTLY AFTER
3 AM. THE MAIN FORECAST PROBLEM FOR TODAY WILL BE COVERAGE...TIMING
AND INTENSITY OF PRECIP WITH THIS SYSTEM AS IT MOVES OVER SW TX THIS
AFTN...AND THEN SWINGS NEWD INTO CENTRAL TX THIS EVENING.
OVERALL...THE TRACK FAVORS OUR SW ZONES WITH THE HIGHEST POPS THIS
MORNING....SRN AREAS THIS AFTERNOON...AND THEN EASTERN AREAS THIS
EVENING. THERE MAY BE A FAIRLY ABRUPT CUTOFF TO THE PRECIP SOMEWHERE
ACROSS THE CENTRAL OR NORTHERN ZONES...BUT WE HAVE KEPT A SLIGHT
CHANCE GOING ACROSS MOST OF THE FAR SRN PANHANDLE THIS AFTN AND EVE
BECAUSE IT IS DIFFICULT TO DETERMINE JUST WHERE THAT CUTOFF MAY LIE.
PROGS OF CAPE GENERALLY SHOW SOMEWHERE BETWEEN 400-800 J/KG MAY BE
PRESENT ACROSS THE THE AREA TODAY...WHEN COUPLED WITH WEAK
DEEP-LAYER SHEAR THIS SHOULD BE SUFFICIENT FOR EMBEDDED TSTMS IN THE
SHOWER ACTIVITY BUT LIKELY KEEP THE SVR POTENTIAL VERY LOW. RAINFALL
AMOUNTS ARE LIKELY TO BE MAXIMIZED ACROSS THE SRN ZONES. FORECAST
PWATS CLIMB TO ABOUT 1.25 INCHES ACROSS THE ROLLING PLAINS THIS
EVENING AND WITH THE CYCLONIC FLOW FEEDING DEEPER MOISTURE INTO THAT
AREA AN INCH OR SO OF RAINFALL IS POSSIBLE. OVERALL...IT APPEARS
THAT THE THREAT OF EXCESSIVE RAINFALL WILL REMAIN WELL OFF TO OUR
SOUTHEAST HOWEVER SOME LOCALLY HEAVIER AMOUNTS COULD CAUSE SOME
MINOR FLOODING ISSUES...WITH THE AREAS OF CONCERN MAINLY SRN YOAKUM
AND TERRY COUNTIES THIS MORNING /WHERE THEY SAW POCKETS OF HEAVY
RAINFALL MONDAY/ AND THEN THE SRN ROLLING PLAINS THIS EVENING. WITH
MORE EXTENSIVE CLOUD COVER ACROSS THE WEST AND SOUTH...WE EXPECT
TEMPS TODAY TO BE SOMEWHAT COOLER THAN YESTERDAY...RANGING FROM
HIGHS NEAR 70F IN THE SOUTHWEST TO LOWER 80S IN THE NE.
LONG TERM...
ADDITIONAL CHANCES FOR MEASURABLE RAINFALL WILL BE COMING UP IN
THE LONG TERM FORECAST.
PRECIPITATION WILL CONTINUE THROUGH THE DAY ON FRIDAY. AN AREA OF
DEFORMATION WILL MOVE OVER THE AREA ON THE NORTH AND WEST SIDE OF
THE SLOW MOVING UPPER LEVEL LOW. THE LOW WILL TRACK OVER THE
SOUTHERN ROLLING PLAINS DURING THE DAY ON FRIDAY. THE NAM/SREF
SOLUTIONS STILL TAKE THE LOW FARTHER SOUTH ON FRIDAY AND SATURDAY THAN
ALL OTHER MODEL SOLUTIONS. HEAVY RAIN WILL LIKELY BE A RESULT OF
THIS SLOW MOVING UPPER LOW. UNFORTUNATELY...MOST OF THIS HEAVY
RAIN WILL BE SOUTH OF THE AREA. PRECIPITATION PROCESSES ARE
EXPECTED TO BE VERY EFFICIENT WITH NEARLY SATURATED
SOUNDINGS...ESPECIALLY OFF THE CAPROCK. BEST CHANCES FOR THE FA
WILL BE OVER THE SOUTHERN ROLLING PLAINS.
A FRONT WILL THEN BACK DOOR INTO THE AREA SATURDAY SETTING UP
MOIST UPSLOPE FLOW THROUGH AT LEAST EARLY NEXT WEEK. THE AXIS OF A
SHARP UPPER LEVEL WAVE WILL MOVE SOUTH THROUGH THE ROCKIES FROM
SUNDAY THROUGH MONDAY. THIS WILL BE OUR NEXT SHOT AT PRECIPITATION
WITH NORTHWEST FLOW STORMS DEVELOPING EACH EVENING. THE BEST
CHANCES AT THE MOMENT APPEAR TO BE ON SUNDAY AND MONDAY EVENING
WHEN UPPER LEVEL LIFT WILL BE IN THE AREA. SATURDAY WILL SEE LESS
OF A CHANCE OF PRECIPITATION WITH UPPER LEVEL LIFT LACKING. HAVE
SIDED MORE WITH THE ECMWF SOLUTION GIVEN ITS CONSISTENT MODEL RUNS
OPPOSED TO THE GFS. ADDITIONALLY...THE GFS APPEARS TO BE SUFFERING
FROM SEVERE CONVECTIVE FEEDBACK DURING THIS TIME PERIOD.
FURTHERMORE...A QUICK GLANCE AT ANALOG GUIDANCE SHOWS HIGH
PROBABILITIES FOR SEVERE WEATHER WITH THIS NEXT SHOT OF
THUNDERSTORMS. JDV
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 75 49 70 49 70 / 20 20 20 10 10
TULIA 77 52 68 50 72 / 20 20 30 10 10
PLAINVIEW 75 52 67 50 72 / 20 20 30 10 10
LEVELLAND 71 51 72 53 75 / 40 30 30 10 10
LUBBOCK 73 52 70 51 74 / 30 30 40 10 10
DENVER CITY 69 51 75 53 75 / 80 30 30 10 10
BROWNFIELD 70 52 73 54 76 / 70 30 30 10 10
CHILDRESS 81 57 68 56 75 / 10 30 40 10 10
SPUR 75 54 69 53 76 / 30 40 50 10 10
ASPERMONT 76 56 72 57 76 / 30 60 60 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
529 AM CDT THU MAY 10 2012
.UPDATE...
A BROAD AREA OF SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY
RAINFALL RATES...ARE MOVING NORTH ACROSS THE WRN PERMIAN BASIN.
THE LATEST HRRR SUGGESTS THIS ACTIVITY WILL PINWHEEL NORTHWESTWARD
AROUND THE BROAD CYCLONIC CIRCULATION OF THE UPPER-LOW. THIS
SHOULD BRING THE ACTIVITY SQUARELY ACROSS COCHRAN...YOAKUM AND
TERRY COUNTIES...WITH A MORE GLANCING BLOW TO LUBBOCK...LYNN AND
HOCKLEY...AND POSSIBLY BAILEY COUNTIES. WE HAVE UPPED POPS AND QPF
FOR THESE AREAS. QUICK RAINFALL OF AN INCH OR SO IS POSSIBLE
ACROSS YOAKUM AND SRN TERRY COUNTIES AND COULD CAUSE SOME MINOR
FLOODING ISSUES.
&&
.PREV DISCUSSION... /ISSUED 334 AM CDT THU MAY 10 2012/
SHORT TERM...
THE UPPER-LOW AS SEEN IN SAT. IMAGERY IS MOVING SLOWLY EAST ACROSS
NRN MEXICO THIS MORNING. A BROAD AREA OF LIFT ON THE NORTHERN AND
EASTERN FLANKS OF THE LOW IS SUPPORTING SCATTERED TSTM ACTIVITY
WHICH AT 230 AM WAS CONCENTRATED ACROSS THE TRANS-PECOS AND WESTERN
PERMIAN BASIN...WHICH APPEARS TO BE ENHANCED BY MOISTURE
ADVECTION/LIFT ON A 20 KT SRLY LLJ. MOST MODEL OUTPUT DOES NOT HAVE
A GREAT HANDLE ON THE LOCATION AND EXTENT OF THE CURRENT
ACTIVITY...WHICH IS ALREADY MOVING INTO GAINES COUNTY...AND APPEARS
LIKELY TO MOVE INTO YOAKUM AND POSSIBLY TERRY COUNTIES SHORTLY AFTER
3 AM. THE MAIN FORECAST PROBLEM FOR TODAY WILL BE COVERAGE...TIMING
AND INTENSITY OF PRECIP WITH THIS SYSTEM AS IT MOVES OVER SW TX THIS
AFTN...AND THEN SWINGS NEWD INTO CENTRAL TX THIS EVENING.
OVERALL...THE TRACK FAVORS OUR SW ZONES WITH THE HIGHEST POPS THIS
MORNING....SRN AREAS THIS AFTERNOON...AND THEN EASTERN AREAS THIS
EVENING. THERE MAY BE A FAIRLY ABRUPT CUTOFF TO THE PRECIP SOMEWHERE
ACROSS THE CENTRAL OR NORTHERN ZONES...BUT WE HAVE KEPT A SLIGHT
CHANCE GOING ACROSS MOST OF THE FAR SRN PANHANDLE THIS AFTN AND EVE
BECAUSE IT IS DIFFICULT TO DETERMINE JUST WHERE THAT CUTOFF MAY LIE.
PROGS OF CAPE GENERALLY SHOW SOMEWHERE BETWEEN 400-800 J/KG MAY BE
PRESENT ACROSS THE THE AREA TODAY...WHEN COUPLED WITH WEAK
DEEP-LAYER SHEAR THIS SHOULD BE SUFFICIENT FOR EMBEDDED TSTMS IN THE
SHOWER ACTIVITY BUT LIKELY KEEP THE SVR POTENTIAL VERY LOW. RAINFALL
AMOUNTS ARE LIKELY TO BE MAXIMIZED ACROSS THE SRN ZONES. FORECAST
PWATS CLIMB TO ABOUT 1.25 INCHES ACROSS THE ROLLING PLAINS THIS
EVENING AND WITH THE CYCLONIC FLOW FEEDING DEEPER MOISTURE INTO THAT
AREA AN INCH OR SO OF RAINFALL IS POSSIBLE. OVERALL...IT APPEARS
THAT THE THREAT OF EXCESSIVE RAINFALL WILL REMAIN WELL OFF TO OUR
SOUTHEAST HOWEVER SOME LOCALLY HEAVIER AMOUNTS COULD CAUSE SOME
MINOR FLOODING ISSUES...WITH THE AREAS OF CONCERN MAINLY SRN YOAKUM
AND TERRY COUNTIES THIS MORNING /WHERE THEY SAW POCKETS OF HEAVY
RAINFALL MONDAY/ AND THEN THE SRN ROLLING PLAINS THIS EVENING. WITH
MORE EXTENSIVE CLOUD COVER ACROSS THE WEST AND SOUTH...WE EXPECT
TEMPS TODAY TO BE SOMEWHAT COOLER THAN YESTERDAY...RANGING FROM
HIGHS NEAR 70F IN THE SOUTHWEST TO LOWER 80S IN THE NE.
LONG TERM...
ADDITIONAL CHANCES FOR MEASURABLE RAINFALL WILL BE COMING UP IN
THE LONG TERM FORECAST.
PRECIPITATION WILL CONTINUE THROUGH THE DAY ON FRIDAY. AN AREA OF
DEFORMATION WILL MOVE OVER THE AREA ON THE NORTH AND WEST SIDE OF
THE SLOW MOVING UPPER LEVEL LOW. THE LOW WILL TRACK OVER THE
SOUTHERN ROLLING PLAINS DURING THE DAY ON FRIDAY. THE NAM/SREF
SOLUTIONS STILL TAKE THE LOW FARTHER SOUTH ON FRIDAY AND SATURDAY THAN
ALL OTHER MODEL SOLUTIONS. HEAVY RAIN WILL LIKELY BE A RESULT OF
THIS SLOW MOVING UPPER LOW. UNFORTUNATELY...MOST OF THIS HEAVY
RAIN WILL BE SOUTH OF THE AREA. PRECIPITATION PROCESSES ARE
EXPECTED TO BE VERY EFFICIENT WITH NEARLY SATURATED
SOUNDINGS...ESPECIALLY OFF THE CAPROCK. BEST CHANCES FOR THE FA
WILL BE OVER THE SOUTHERN ROLLING PLAINS.
A FRONT WILL THEN BACK DOOR INTO THE AREA SATURDAY SETTING UP
MOIST UPSLOPE FLOW THROUGH AT LEAST EARLY NEXT WEEK. THE AXIS OF A
SHARP UPPER LEVEL WAVE WILL MOVE SOUTH THROUGH THE ROCKIES FROM
SUNDAY THROUGH MONDAY. THIS WILL BE OUR NEXT SHOT AT PRECIPITATION
WITH NORTHWEST FLOW STORMS DEVELOPING EACH EVENING. THE BEST
CHANCES AT THE MOMENT APPEAR TO BE ON SUNDAY AND MONDAY EVENING
WHEN UPPER LEVEL LIFT WILL BE IN THE AREA. SATURDAY WILL SEE LESS
OF A CHANCE OF PRECIPITATION WITH UPPER LEVEL LIFT LACKING. HAVE
SIDED MORE WITH THE ECMWF SOLUTION GIVEN ITS CONSISTENT MODEL RUNS
OPPOSED TO THE GFS. ADDITIONALLY...THE GFS APPEARS TO BE SUFFERING
FROM SEVERE CONVECTIVE FEEDBACK DURING THIS TIME PERIOD.
FURTHERMORE...A QUICK GLANCE AT ANALOG GUIDANCE SHOWS HIGH
PROBABILITIES FOR SEVERE WEATHER WITH THIS NEXT SHOT OF
THUNDERSTORMS. JDV
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 75 49 70 49 70 / 20 20 20 10 10
TULIA 77 52 68 50 72 / 20 20 30 10 10
PLAINVIEW 75 52 67 50 72 / 20 20 30 10 10
LEVELLAND 71 51 72 53 75 / 40 30 30 10 10
LUBBOCK 73 52 70 51 74 / 30 30 40 10 10
DENVER CITY 69 51 75 53 75 / 80 30 30 10 10
BROWNFIELD 70 52 73 54 76 / 70 30 30 10 10
CHILDRESS 81 57 68 56 75 / 10 30 40 10 10
SPUR 75 54 69 53 76 / 30 40 50 10 10
ASPERMONT 76 56 72 57 76 / 30 60 60 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1127 PM EDT FRI MAY 11 2012
.SYNOPSIS...
HIGH PRESSURE WILL SLIDE EAST ACROSS THE REGION TONIGHT BEFORE
PASSING OFFSHORE ON SATURDAY. RETURN SOUTHERLY FLOW AROUND THE
HIGH WILL BRING INCREASING MOISTURE BACK TO THE AREA LATE SATURDAY
THROUGH SUNDAY. A COLD FRONT WILL DRIFT EAST ACROSS THE REGION
SUNDAY NIGHT INTO MONDAY...POSSIBLY RESULTING IN MORE WIDESPREAD
SIGNIFICANT RAINFALL INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 1115 PM EDT FRIDAY...
HIGH CLOUDS FANNING OUT AHEAD OF THE DEEPER MOISTURE AXIS TO THE
WEST SHOULD REMAIN QUITE THIN OVERNIGHT GIVEN DRY AIR IN PLACE PER
EVENING RAOBS AND SUBSIDENCE UNDER HIGH PRESSURE. THEREFORE ONLY
MADE SOME SMALL UPWARD TWEAKS TO SKY COVER MAINLY OVER THE WEST
LATE TONIGHT WHEN THE MORE AGGRESSIVE NAM SHOWS A THICKER CANOPY
ARRIVING BY DAYBREAK. OTRW GOING CLEAR TO MOSTLY CLEAR FORECAST ON
TRACK WITH THE BETTER MOISTURE ADVECTION NOT ARRIVING UNTIL LATER
SATURDAY. SHOULD BE ANOTHER RATHER COOL OVERNIGHT PER LOW
DEWPOINTS AND LIGHT WINDS UNDER HIGH PRESSURE PROVIDING GOOD
RADIATIONAL COOLING DESPITE SOME HIGH CLOUDS. LOOKS LIKE SPOTTY 30S
AGAIN VALLEYS WITH SOME PATCHY FROST POSSIBLE MAINLY FAR NW BUT
NOT ENOUGH FOR AN ADVISORY GIVEN BRIEF NATURE AT THIS POINT. OTRW
APPEARS SHOULD SEE MOST OTHER LOCATIONS IN THE 40S BY MORNING SO
BUMPED DOWN LOWS A LITTLE.
PREVIOUS DISCUSSION AS OF 250 PM EDT FRIDAY...
UPPER RIDGE/SFC HIGH PRESSURE WILL SETTLE OVERHEAD TONIGHT.
EXPECT GOOD RADIATIONAL COOLING CONDITIONS UNDER CLEAR SKIES AND
LIGHT WINDS. LOWS WILL RANGE FROM THE UPPER 30S IN THE COLDER VALLEY
TO THE MID 40S IN THE SOUTH.
MOISTURE SLOWLY INCREASES ON SATURDAY AS SURFACE LOW PRESSURE MOVES
INTO THE LOWER MISSISSIPPI VALLEY. WITH POOLING OF MOISTURE AND
UPSLOPE FLOW...ALLOWED FOR SOME LIGHT SHOWERS IN THE SOUTHWEST
MOUNTAINS SATURDAY AFTERNOON. PLAYED HIGH TEMPERATURES SATURDAY
AFTERNOON FROM THE UPPER 60S IN THE MOUNTAINS TO THE MID 70S IN THE
SOUTHEAST.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT FRIDAY...
DETERIORATING WEATHER CONDITIONS EXPECTED DURING THE SHORT TERM
PERIOD OF THE FORECAST...AS ENERGY FROM SOUTHERN STREAM LOW ACROSS
TEXAS TODAY MERGES WITH A NORTHERN STREAM WAVE MOVING THROUGH THE
GREAT LAKES.
THE FIRST FORECAST CONCERN IS WHEN PRECIP DEVELOPS. THE GFS MOISTENS
THE AIRMASS QUICKLY...INCREASING PWATS TO OVER AN INCH OVER MUCH OF
THE FORECAST AREA BY SUNDAY MORNING. THE NAM IS MUCH SLOWER...BUT
WAS DISREGARDED. WITH THE LOW LEVEL THETA-E RIDGE SNEAKING UP THE
FAR WESTERN PORTION OF THE FORECAST AREA...COMBINED WITH ISENTROPIC
LIFT...KEPT SMALL POPS ACROSS THE FAR WESTERN PORTION OF THE
FORECAST AREA.
ON SUNDAY...WEAK SHORT WAVES BEGIN TO INVADE THE AREA FROM THE
SOUTHWEST IN A DEEP SOUTHWEST FLOW. MOST OF THE PRECIPITATION
SHOULD REMAIN IN THE WESTERN HALF OF THE FORECAST AREA UNDER THE
THETA-E RIDGE.
PRECIP SHOULD EXPAND EAST OF THE BLUE RIDGE BY LATE SUNDAY NIGHT AND
ESPECIALLY MONDAY AS THE SFC COLD FRONT APPROACHES AND LOW LEVEL
WINDS BACK...INCREASING LOW LEVEL CONVERGENCE. PLUS A BROAD AREA OF
UPPER DIVERGENCE FORMS AS OUR FORECAST AREA FALLS UNDER THE RR QUAD
OF NORTHERN STREAM JET.
THIS SPELLS THE POTENTIAL FOR A HEAVY RAIN EVENT ON MONDAY..AS
PWATS INCREASE TO GREATER THAN 2 STANDARD DEVIATIONS ABOVE NORMAL ON
MONDAY...AND WITH GEFS...AND TO LESSER EXTENT...NAEFS HYDROLOGIC
ENSEMBLES SHOWING A SMALL CHANCE SOME RIVER GAUGE LOCATIONS
EXCEEDING ACTION STAGE. THEREFORE...WILL INTRODUCE A MENTION OF THE
THREAT FOR MINOR FLOODING IN THE HWO.
WITH EXTENSIVE CLOUD COVER AND PRECIP EXPANDING IN
COVERAGE...NARROWED THE DIURNAL RANGE IN TEMPS...INCREASING LOWS AND
REDUCING HIGHS...ESPECIALLY MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 230 PM EDT THURSDAY...
AN ACTIVE WEATHER PATTERN IS IN STORE FOR THE EARLY PART OF THE LONG
TERM PERIOD. BOTH THE GFS AND ECMWF PHASE THE SOUTHERN STREAM LOW
CURRENTLY IN TEXAS...WITH A NORTHERN STREAM WAVE MOVING ACROSS THE
GREAT LAKES. THE RESULTS IN A PERSISTENT LONG WAVE TROF ACROSS THE
EASTERN U.S...WITH WAVES OF LOW PRESSURE AT THE SFC RIDING NORTHEAST
ALONG A SLOW MOVING FRONTAL BOUNDARY THROUGH TUESDAY NIGHT AND
POTENTIALLY INTO WEDNESDAY.
THE 00Z ECMWF IS MOST PROGRESSIVE WITH MOVING THE AXIS OF THIS UPPER
TROF TO THE EAST OF OUR AREA WEDNESDAY...WHILE THE 06Z GFS IS MUCH
SLOWER AND DEEPER...WHICH APPEARS TO BE AN OUTLIER WHEN COMPARED TO
ITS ENSEMBLES. A SOLUTION SOMEWHERE BETWEEN IS PROBABLY THE MOST
LIKELY SCENARIO...AS THE ECMWF ENSEMBLE MEAN SUGGESTS. AS A
RESULT...KEPT POPS IN THE FORECAST FOR WEDNESDAY.
LATER THE LONG TERM PERIOD...THE LONG RANGE MODELS DIVERGENCE
CONSIDERABLY ON THE WHAT WILL TRANSPIRE. THE 12Z GFS DEVELOPS A CUT
OFF LOW IN EASTERN NC...WHILE 0Z ECMWF LIFTS THE EASTERN U.S. TROF
WELL AWAY FROM OUR AREA. THE MAJORITY OF THE INDIVIDUAL GFS
ENSEMBLES AGREE WITH THE ECMWF ENSEMBLE MEAN OF KEEPING AN OPEN
UPPER LEVEL TROF OVER THE EASTERN U.S. WITH THE RNK FORECAST AREA
JUST TO THE WEST OF THE UPPER TROF AXIS FROM THE ENSEMBLE
MEANS...WILL KEEP THE FORECAST DRY...BUT CONFIDENCE IS LOW DURING
THIS TIME.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
AS OF 650 PM EDT FRIDAY...
OVERALL VFR TO CONTINUE FOR MOST OF THE PERIOD...WITH SOME
INCREASE IN HIGH CLOUDS OVERNIGHT...FOLLOWED BY A MIX OF SCT/BKN
4-6K CU/SC UNDER A BKN/OVC HIGH CLOUD CANOPY SATURDAY. MOISTURE
MAY ALSO INCREASE ENOUGH AS THE FLOW TURNS MORE SOUTHERLY SATURDAY
AFTERNOON TO PROMOTE A FEW SHOWERS OVER THE FAR WEST AND SW BUT
TOO IFFY TO INCLUDE MENTION IN THE TAFS...PRIMARILY AROUND KBLF
WHERE APPEARS AN ISOLATED SHOWER IS POSSIBLE LATE IN THE DAY.
WINDS WILL BECOME LIGHT AND VARIABLE OVERNIGHT...THEN MIX OUT TO
SOUTH OR SW AT 7-15 KTS DURING SATURDAY AFTERNOON AS HIGH PRESSURE
MOVES TO THE EAST.
BY SATURDAY NIGHT...THE HIGH MOVES OFFSHORE AND DEEPER MOISTURE
BEGINS TO ADVANCE NORTH ACROSS THE SOUTHERN APPALACHIANS WITH
POSSIBLE MVFR CIGS IN SCATTERED SHRA AT TIMES ESPCLY AROUND
KBLF/KLWB. CEILINGS AND VISIBILITIES MAY CONTINUE AT MVFR LEVELS
AT KBLF AND KLWB ON SUNDAY THEN ALSO AT ALL OTHER SITES SUNDAY
NIGHT THROUGH TUESDAY AS LOW PRESSURE AND THE ASSOCIATED
PRECIPITATION MOVE EAST. IFR CONDITIONS WILL ALSO BE POSSIBLE
ESPCLY ACROSS THE WESTERN LOCATIONS SUNDAY NIGHT INTO MONDAY
ASSOCIATED WITH AN AXIS OF RAINFALL ALONG THE FRONT. DRIER AIR
SHOULD FINALLY WORK IN TUESDAY NIGHT INTO WEDNESDAY BRINGING A
RETURN TO VFR BY MIDWEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/KK
SHORT TERM...PH
LONG TERM...PH
AVIATION...JH/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
914 PM EDT FRI MAY 11 2012
.SYNOPSIS...
HIGH PRESSURE WILL SLIDE EAST ACROSS THE REGION TONIGHT BEFORE
PASSING OFFSHORE ON SATURDAY. RETURN SOUTHERLY FLOW AROUND THE
HIGH WILL BRING INCREASING MOISTURE BACK TO THE AREA LATE SATURDAY
THROUGH SUNDAY. A COLD FRONT WILL DRIFT EAST ACROSS THE REGION
SUNDAY NIGHT INTO MONDAY...POSSIBLY RESULTING IN MORE WIDESPREAD
SIGNIFICANT RAINFALL INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 835 PM EDT FRIDAY...
HIGH CLOUDS FANNING OUT AHEAD OF THE DEEPER MOISTURE AXIS TO THE
WEST SHOULD REMAIN QUITE THIN OVERNIGHT GIVEN DRY AIR IN PLACE PER
EVENING RAOBS AND SUBSIDENCE UNDER HIGH PRESSURE. THEREFORE ONLY
MADE SOME SMALL UPWARD TWEAKS TO SKY COVER MAINLY OVER THE WEST
LATE TONIGHT WHEN THE MORE AGGRESSIVE NAM SHOWS A THICKER CANOPY
ARRIVING BY DAYBREAK. OTRW GOING CLEAR TO MOSTLY CLEAR FORECAST ON
TRACK WITH THE BETTER MOISTURE ADVECTION NOT ARRIVING UNTIL LATER
SATURDAY. SHOULD BE ANOTHER RATHER COOL OVERNIGHT PER LOW
DEWPOINTS AND LIGHT WINDS UNDER HIGH PRESSURE PROVIDING GOOD
RADIATIONAL COOLING DESPITE SOME HIGH CLOUDS. LOOKS LIKE SPOTTY 30S
AGAIN POSSIBLE VALLEYS WITH MOST OTHER LOCATIONS IN THE 40S BY
MORNING SO BUMPED DOWN LOWS A LITTLE.
PREVIOUS DISCUSSION AS OF 250 PM EDT FRIDAY...
UPPER RIDGE/SFC HIGH PRESSURE WILL SETTLE OVERHEAD TONIGHT.
EXPECT GOOD RADIATIONAL COOLING CONDITIONS UNDER CLEAR SKIES AND
LIGHT WINDS. LOWS WILL RANGE FROM THE UPPER 30S IN THE COLDER VALLEY
TO THE MID 40S IN THE SOUTH.
MOISTURE SLOWLY INCREASES ON SATURDAY AS SURFACE LOW PRESSURE MOVES
INTO THE LOWER MISSISSIPPI VALLEY. WITH POOLING OF MOISTURE AND
UPSLOPE FLOW...ALLOWED FOR SOME LIGHT SHOWERS IN THE SOUTHWEST
MOUNTAINS SATURDAY AFTERNOON. PLAYED HIGH TEMPERATURES SATURDAY
AFTERNOON FROM THE UPPER 60S IN THE MOUNTAINS TO THE MID 70S IN THE
SOUTHEAST.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT FRIDAY...
DETERIORATING WEATHER CONDITIONS EXPECTED DURING THE SHORT TERM
PERIOD OF THE FORECAST...AS ENERGY FROM SOUTHERN STREAM LOW ACROSS
TEXAS TODAY MERGES WITH A NORTHERN STREAM WAVE MOVING THROUGH THE
GREAT LAKES.
THE FIRST FORECAST CONCERN IS WHEN PRECIP DEVELOPS. THE GFS MOISTENS
THE AIRMASS QUICKLY...INCREASING PWATS TO OVER AN INCH OVER MUCH OF
THE FORECAST AREA BY SUNDAY MORNING. THE NAM IS MUCH SLOWER...BUT
WAS DISREGARDED. WITH THE LOW LEVEL THETA-E RIDGE SNEAKING UP THE
FAR WESTERN PORTION OF THE FORECAST AREA...COMBINED WITH ISENTROPIC
LIFT...KEPT SMALL POPS ACROSS THE FAR WESTERN PORTION OF THE
FORECAST AREA.
ON SUNDAY...WEAK SHORT WAVES BEGIN TO INVADE THE AREA FROM THE
SOUTHWEST IN A DEEP SOUTHWEST FLOW. MOST OF THE PRECIPITATION
SHOULD REMAIN IN THE WESTERN HALF OF THE FORECAST AREA UNDER THE
THETA-E RIDGE.
PRECIP SHOULD EXPAND EAST OF THE BLUE RIDGE BY LATE SUNDAY NIGHT AND
ESPECIALLY MONDAY AS THE SFC COLD FRONT APPROACHES AND LOW LEVEL
WINDS BACK...INCREASING LOW LEVEL CONVERGENCE. PLUS A BROAD AREA OF
UPPER DIVERGENCE FORMS AS OUR FORECAST AREA FALLS UNDER THE RR QUAD
OF NORTHERN STREAM JET.
THIS SPELLS THE POTENTIAL FOR A HEAVY RAIN EVENT ON MONDAY..AS
PWATS INCREASE TO GREATER THAN 2 STANDARD DEVIATIONS ABOVE NORMAL ON
MONDAY...AND WITH GEFS...AND TO LESSER EXTENT...NAEFS HYDROLOGIC
ENSEMBLES SHOWING A SMALL CHANCE SOME RIVER GAUGE LOCATIONS
EXCEEDING ACTION STAGE. THEREFORE...WILL INTRODUCE A MENTION OF THE
THREAT FOR MINOR FLOODING IN THE HWO.
WITH EXTENSIVE CLOUD COVER AND PRECIP EXPANDING IN
COVERAGE...NARROWED THE DIURNAL RANGE IN TEMPS...INCREASING LOWS AND
REDUCING HIGHS...ESPECIALLY MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 230 PM EDT THURSDAY...
AN ACTIVE WEATHER PATTERN IS IN STORE FOR THE EARLY PART OF THE LONG
TERM PERIOD. BOTH THE GFS AND ECMWF PHASE THE SOUTHERN STREAM LOW
CURRENTLY IN TEXAS...WITH A NORTHERN STREAM WAVE MOVING ACROSS THE
GREAT LAKES. THE RESULTS IN A PERSISTENT LONG WAVE TROF ACROSS THE
EASTERN U.S...WITH WAVES OF LOW PRESSURE AT THE SFC RIDING NORTHEAST
ALONG A SLOW MOVING FRONTAL BOUNDARY THROUGH TUESDAY NIGHT AND
POTENTIALLY INTO WEDNESDAY.
THE 00Z ECMWF IS MOST PROGRESSIVE WITH MOVING THE AXIS OF THIS UPPER
TROF TO THE EAST OF OUR AREA WEDNESDAY...WHILE THE 06Z GFS IS MUCH
SLOWER AND DEEPER...WHICH APPEARS TO BE AN OUTLIER WHEN COMPARED TO
ITS ENSEMBLES. A SOLUTION SOMEWHERE BETWEEN IS PROBABLY THE MOST
LIKELY SCENARIO...AS THE ECMWF ENSEMBLE MEAN SUGGESTS. AS A
RESULT...KEPT POPS IN THE FORECAST FOR WEDNESDAY.
LATER THE LONG TERM PERIOD...THE LONG RANGE MODELS DIVERGENCE
CONSIDERABLY ON THE WHAT WILL TRANSPIRE. THE 12Z GFS DEVELOPS A CUT
OFF LOW IN EASTERN NC...WHILE 0Z ECMWF LIFTS THE EASTERN U.S. TROF
WELL AWAY FROM OUR AREA. THE MAJORITY OF THE INDIVIDUAL GFS
ENSEMBLES AGREE WITH THE ECMWF ENSEMBLE MEAN OF KEEPING AN OPEN
UPPER LEVEL TROF OVER THE EASTERN U.S. WITH THE RNK FORECAST AREA
JUST TO THE WEST OF THE UPPER TROF AXIS FROM THE ENSEMBLE
MEANS...WILL KEEP THE FORECAST DRY...BUT CONFIDENCE IS LOW DURING
THIS TIME.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
AS OF 650 PM EDT FRIDAY...
OVERALL VFR TO CONTINUE FOR MOST OF THE PERIOD...WITH SOME
INCREASE IN HIGH CLOUDS OVERNIGHT...FOLLOWED BY A MIX OF SCT/BKN
4-6K CU/SC UNDER A BKN/OVC HIGH CLOUD CANOPY SATURDAY. MOISTURE
MAY ALSO INCREASE ENOUGH AS THE FLOW TURNS MORE SOUTHERLY SATURDAY
AFTERNOON TO PROMOTE A FEW SHOWERS OVER THE FAR WEST AND SW BUT
TOO IFFY TO INCLUDE MENTION IN THE TAFS...PRIMARILY AROUND KBLF
WHERE APPEARS AN ISOLATED SHOWER IS POSSIBLE LATE IN THE DAY.
WINDS WILL BECOME LIGHT AND VARIABLE OVERNIGHT...THEN MIX OUT TO
SOUTH OR SW AT 7-15 KTS DURING SATURDAY AFTERNOON AS HIGH PRESSURE
MOVES TO THE EAST.
BY SATURDAY NIGHT...THE HIGH MOVES OFFSHORE AND DEEPER MOISTURE
BEGINS TO ADVANCE NORTH ACROSS THE SOUTHERN APPALACHIANS WITH
POSSIBLE MVFR CIGS IN SCATTERED SHRA AT TIMES ESPCLY AROUND
KBLF/KLWB. CEILINGS AND VISIBILITIES MAY CONTINUE AT MVFR LEVELS
AT KBLF AND KLWB ON SUNDAY THEN ALSO AT ALL OTHER SITES SUNDAY
NIGHT THROUGH TUESDAY AS LOW PRESSURE AND THE ASSOCIATED
PRECIPITATION MOVE EAST. IFR CONDITIONS WILL ALSO BE POSSIBLE
ESPCLY ACROSS THE WESTERN LOCATIONS SUNDAY NIGHT INTO MONDAY
ASSOCIATED WITH AN AXIS OF RAINFALL ALONG THE FRONT. DRIER AIR
SHOULD FINALLY WORK IN TUESDAY NIGHT INTO WEDNESDAY BRINGING A
RETURN TO VFR BY MIDWEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/KK
SHORT TERM...PH
LONG TERM...PH
AVIATION...JH/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
717 PM EDT FRI MAY 11 2012
.SYNOPSIS...
HIGH PRESSURE WILL SLIDE EAST ACROSS THE REGION TONIGHT BEFORE
PASSING OFFSHORE ON SATURDAY. RETURN SOUTHERLY FLOW AROUND THE
HIGH WILL BRING INCREASING MOISTURE BACK TO THE AREA LATE SATURDAY
THROUGH SUNDAY. A COLD FRONT WILL DRIFT EAST ACROSS THE REGION
SUNDAY NIGHT INTO MONDAY POSSIBLY RESULTING IN MORE WIDESPREAD
SIGNIFICANT RAINFALL INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 250 PM EDT FRIDAY...
UPPER RIDGE/SFC HIGH PRESSURE WILL SETTLE OVERHEAD TONIGHT.
EXPECT GOOD RADIATIONAL COOLING CONDITIONS UNDER CLEAR SKIES AND
LIGHT WINDS. LOWS WILL RANGE FROM THE UPPER 30S IN THE COLDER VALLEY
TO THE MID 40S IN THE SOUTH.
MOISTURE SLOWLY INCREASES ON SATURDAY AS SURFACE LOW PRESSURE MOVES
INTO THE LOWER MISSISSIPPI VALLEY. WITH POOLING OF MOISTURE AND
UPSLOPE FLOW...ALLOWED FOR SOME LIGHT SHOWERS IN THE SOUTHWEST
MOUNTAINS SATURDAY AFTERNOON. PLAYED HIGH TEMPERATURES SATURDAY
AFTERNOON FROM THE UPPER 60S IN THE MOUNTAINS TO THE MID 70S IN THE
SOUTHEAST.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT FRIDAY...
DETERIORATING WEATHER CONDITIONS EXPECTED DURING THE SHORT TERM
PERIOD OF THE FORECAST...AS ENERGY FROM SOUTHERN STREAM LOW ACROSS
TEXAS TODAY MERGES WITH A NORTHERN STREAM WAVE MOVING THROUGH THE
GREAT LAKES.
THE FIRST FORECAST CONCERN IS WHEN PRECIP DEVELOPS. THE GFS MOISTENS
THE AIRMASS QUICKLY...INCREASING PWATS TO OVER AN INCH OVER MUCH OF
THE FORECAST AREA BY SUNDAY MORNING. THE NAM IS MUCH SLOWER...BUT
WAS DISREGARDED. WITH THE LOW LEVEL THETA-E RIDGE SNEAKING UP THE
FAR WESTERN PORTION OF THE FORECAST AREA...COMBINED WITH ISENTROPIC
LIFT...KEPT SMALL POPS ACROSS THE FAR WESTERN PORTION OF THE
FORECAST AREA.
ON SUNDAY...WEAK SHORT WAVES BEGIN TO INVADE THE AREA FROM THE
SOUTHWEST IN A DEEP SOUTHWEST FLOW. MOST OF THE PRECIPITATION
SHOULD REMAIN IN THE WESTERN HALF OF THE FORECAST AREA UNDER THE
THETA-E RIDGE.
PRECIP SHOULD EXPAND EAST OF THE BLUE RIDGE BY LATE SUNDAY NIGHT AND
ESPECIALLY MONDAY AS THE SFC COLD FRONT APPROACHES AND LOW LEVEL
WINDS BACK...INCREASING LOW LEVEL CONVERGENCE. PLUS A BROAD AREA OF
UPPER DIVERGENCE FORMS AS OUR FORECAST AREA FALLS UNDER THE RR QUAD
OF NORTHERN STREAM JET.
THIS SPELLS THE POTENTIAL FOR A HEAVY RAIN EVENT ON MONDAY..AS
PWATS INCREASE TO GREATER THAN 2 STANDARD DEVIATIONS ABOVE NORMAL ON
MONDAY...AND WITH GEFS...AND TO LESSER EXTENT...NAEFS HYDROLOGIC
ENSEMBLES SHOWING A SMALL CHANCE SOME RIVER GAUGE LOCATIONS
EXCEEDING ACTION STAGE. THEREFORE...WILL INTRODUCE A MENTION OF THE
THREAT FOR MINOR FLOODING IN THE HWO.
WITH EXTENSIVE CLOUD COVER AND PRECIP EXPANDING IN
COVERAGE...NARROWED THE DIURNAL RANGE IN TEMPS...INCREASING LOWS AND
REDUCING HIGHS...ESPECIALLY MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 230 PM EDT THURSDAY...
AN ACTIVE WEATHER PATTERN IS IN STORE FOR THE EARLY PART OF THE LONG
TERM PERIOD. BOTH THE GFS AND ECMWF PHASE THE SOUTHERN STREAM LOW
CURRENTLY IN TEXAS...WITH A NORTHERN STREAM WAVE MOVING ACROSS THE
GREAT LAKES. THE RESULTS IN A PERSISTENT LONG WAVE TROF ACROSS THE
EASTERN U.S...WITH WAVES OF LOW PRESSURE AT THE SFC RIDING NORTHEAST
ALONG A SLOW MOVING FRONTAL BOUNDARY THROUGH TUESDAY NIGHT AND
POTENTIALLY INTO WEDNESDAY.
THE 00Z ECMWF IS MOST PROGRESSIVE WITH MOVING THE AXIS OF THIS UPPER
TROF TO THE EAST OF OUR AREA WEDNESDAY...WHILE THE 06Z GFS IS MUCH
SLOWER AND DEEPER...WHICH APPEARS TO BE AN OUTLIER WHEN COMPARED TO
ITS ENSEMBLES. A SOLUTION SOMEWHERE BETWEEN IS PROBABLY THE MOST
LIKELY SCENARIO...AS THE ECMWF ENSEMBLE MEAN SUGGESTS. AS A
RESULT...KEPT POPS IN THE FORECAST FOR WEDNESDAY.
LATER THE LONG TERM PERIOD...THE LONG RANGE MODELS DIVERGENCE
CONSIDERABLY ON THE WHAT WILL TRANSPIRE. THE 12Z GFS DEVELOPS A CUT
OFF LOW IN EASTERN NC...WHILE 0Z ECMWF LIFTS THE EASTERN U.S. TROF
WELL AWAY FROM OUR AREA. THE MAJORITY OF THE INDIVIDUAL GFS
ENSEMBLES AGREE WITH THE ECMWF ENSEMBLE MEAN OF KEEPING AN OPEN
UPPER LEVEL TROF OVER THE EASTERN U.S. WITH THE RNK FORECAST AREA
JUST TO THE WEST OF THE UPPER TROF AXIS FROM THE ENSEMBLE
MEANS...WILL KEEP THE FORECAST DRY...BUT CONFIDENCE IS LOW DURING
THIS TIME.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 650 PM EDT FRIDAY...
OVERALL VFR TO CONTINUE FOR MOST OF THE PERIOD...WITH SOME
INCREASE IN HIGH CLOUDS OVERNIGHT...FOLLOWED BY A MIX OF SCT/BKN
4-6K CU/SC UNDER A BKN/OVC HIGH CLOUD CANOPY SATURDAY. MOISTURE
MAY ALSO INCREASE ENOUGH AS THE FLOW TURNS MORE SOUTHERLY SATURDAY
AFTERNOON TO PROMOTE A FEW SHOWERS OVER THE FAR WEST AND SW BUT
TOO IFFY TO INCLUDE MENTION IN THE TAFS...PRIMARILY AROUND KBLF
WHERE APPEARS AN ISOLATED SHOWER IS POSSIBLE LATE IN THE DAY.
WINDS WILL BECOME LIGHT AND VARIABLE OVERNIGHT...THEN MIX OUT TO
SOUTH OR SW AT 7-15 KTS DURING SATURDAY AFTERNOON AS HIGH PRESSURE
MOVES TO THE EAST.
BY SATURDAY NIGHT...THE HIGH MOVES OFFSHORE AND DEEPER MOISTURE
BEGINS TO ADVANCE NORTH ACROSS THE SOUTHERN APPALACHIANS WITH
POSSIBLE MVFR CIGS IN SCATTERED SHRA AT TIMES ESPCLY AROUND
KBLF/KLWB. CEILINGS AND VISIBILITIES MAY CONTINUE AT MVFR LEVELS
AT KBLF AND KLWB ON SUNDAY THEN ALSO AT ALL OTHER SITES SUNDAY
NIGHT THROUGH TUESDAY AS LOW PRESSURE AND THE ASSOCIATED
PRECIPITATION MOVE EAST. IFR CONDITIONS WILL ALSO BE POSSIBLE
ESPCLY ACROSS THE WESTERN LOCATIONS SUNDAY NIGHT INTO MONDAY
ASSOCIATED WITH AN AXIS OF RAINFALL ALONG THE FRONT. DRIER AIR
SHOULD FINALLY WORK IN TUESDAY NIGHT INTO WEDNESDAY BRINGING A
RETURN TO VFR BY MIDWEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...KK
SHORT TERM...PH
LONG TERM...PH
AVIATION...JH/KK
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
907 PM MDT FRI MAY 11 2012
.UPDATE...CHEYENNE TRANSPORTATION MANAGEMENT CENTER REPORTS AREAS
OF DENSE FOG OVER THE SUMMIT OF INTERSTATE 80 BETWEEN CHEYENNE AND
LARAMIE...ALSO EVIDENT ON WEBCAM IMAGES. WITH CONTINUED MOIST
SOUTHEAST UPSLOPE LOW LEVEL WINDS THROUGH MID MORNING SATURDAY...
WE HAVE ISSUED A DENSE FOG ADVISORY THROUGH 9 AM SATURDAY MORNING
FOR THE SOUTHERN LARAMIE RANGE AND EASTERN FOOTHILLS OF THE SOUTHERN
LARAMIE RANGE...INCLUDING VEDAUWOO AND BUFORD. RUBIN
&&
.PREV DISCUSSION... /ISSUED 637 PM MDT FRI MAY 11 2012/
UPDATE...BASED ON WSR-88D REFLECTIVITY IMAGES FROM CHEYENNE...
GRAND JUNCTION...RIVERTON...RAPID CITY...NORTH PLATTE AND DENVER
(FRONT RANGE)...HAVE REMOVED EVENING SHOWER CHANCES FROM THE
GRIDDED FORECASTS. ALSO ADJUSTED CLOUD COVER GRIDS TO ADJUST
FOR CURRENT CLOUD COVER SOUTH OF A LARAMIE TO CHADRON LINE AND
EXPECTED CLOUD COVER OVERNIGHT. UPDATES HAVE BEEN SENT. RUBIN
PREV DISCUSSION... /ISSUED 526 PM MDT FRI MAY 11 2012/
AVIATION...00Z TAFS
FAVORABLE WIND DIRECTION FOR MARGINAL CONDITIONS AT
CHEYENNE...LARAMIE AND SIDNEY. HRRR GUIDANCE SHOWING IFR
CONDITIONS DEVELOPING AT THESE LOCATIONS OVERNIGHT...CONTINUING
INTO SATURDAY MORNING. WILL NEED TO MONITOR CLOSELY THIS EVENING.
DOUBTS ARE THERE THAT WE HAVE SUFFICIENT LOW LEVEL MOISTURE TO
SUSTAIN THESE LOW CONDITIONS.
CLAYCOMB
PREV DISCUSSION... /ISSUED 311 PM MDT FRI MAY 11 2012/
SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...
WIDELY SCATTERED SHOWERS NOW CONFINED TO MAINLY THE SOUTHEAST PART
OF THE NEBRASKA PANHANDLE AS WELL AS OVER THE HIGHER MOUNTAINS
CLOSE TO THE COLORADO BORDER. EXPECT THESE TO MOVE EAST AND PRETTY
MUCH OUT OF THE CWA BY EARLY THIS EVENING. COOL CONDITIONS WILL
CONTINUE ESPECIALLY OVER THE PLAINS TONIGHT AND SATURDAY AS SFC
HIGH SLOWLY SLIDES EAST OVER THE CENTRAL PLAINS. EXPECT SOME
WIDELY SCATTERED SHOWERS ALONG WITH A WEAK STORM OR TWO TO DEVELOP
MAINLY OVER THE MTNS SATURDAY AFTERNOON AS SOME MOISTURE INTERACTS
WITH AN APPROACHING SHORTWAVE DROPPING ACROSS THE NORTHERN ROCKIES.
SHOWERS SHOULD PERSIST INTO SATURDAY EVENING AS THE WAVE MOVES
ACROSS THEN DRIER AND A LITTLE WARMER SUNDAY BEHIND THE SHORTWAVE.
LONG TERM...MONDAY THROUGH FRIDAY...
THE 12Z SHORT RANGE MODELS HAVE NOT CHANGED MUCH FROM THE PREVIOUS
FEW FORECAST CYCLES. MONDAY AND TUESDAY WILL BE INFLUENCED BY A
RIDGE OF HIGH PRESSURE AT THE SURFACE AND ALOFT. INSTABILITY AND
MOISTURE WILL BE NEGLIGIBLE BOTH DAYS...THEREFORE NO SENSIBLE
WEATHER AND LIGHT WINDS ARE FORECAST. THEN THE MODELS HANDLE THE
CLOSED UPPER LOW MOVING FROM NORTHERN CALIFORNIA THROUGH THE GREAT
BASIN DIFFERENTLY. THE GFS/ECMWF TRANSITION THE LOW INTO A
SHORTWAVE TROUGH ON WEDNESDAY AS IT APPROACHES THE CENTRAL
ROCKIES. THE GEM-NHEM IS SLIGHTLY DEEPER AND SLOWER WITH THIS
FEATURE. DESPITE MARGINAL INSTABILITY OVER THE CWA...LIFT AND
MOISTURE FOR ISOLATED AFTERNOON CONVECTION WILL BE RELEGATED TO
THE HIGHER TERRAIN IN COLORADO. FLOW ALOFT THURSDAY WILL BE
ZONAL...THEN TRANSITION TO SOUTHWEST ON FRIDAY IN ADVANCE OF THE
NEXT SHORTWAVE TROUGH TO THE WEST. LIFT FROM A WEAK WAVE
TRANSLATING EAST ACROSS WYOMING THURSDAY MAY BE SUFFICIENT TO
TRIGGER ISOLATED AFTERNOON CONVECTION OVER THE HIGHER TERRAIN IN
SOUTHEAST WYOMING. FRIDAY APPEARS DRY FOR NOW AS A RIDGE BUILDS
OVER THE HIGH PLAINS. EXPECT BREEZY CONDITIONS WEDNESDAY THROUGH
FRIDAY WEST OF THE LARAMIE RANGE...MAINLY DURING THE DAYLIGHT
HOURS. TEMPERATURES EACH DAY WILL AVERAGE ABOVE SEASONAL
NORMALS...WITH THE WARMEST DAY ON WEDNESDAY.
AVIATION...18Z TAF ISSUANCE...
VFR CEILINGS BETWEEN 5000 AND 10000 FEET AGL WILL PREVAIL FOR
MOST AREA AIRFIELDS THROUGH THE AFTERNOON. SURFACE WINDS WILL VARY
FROM NORTHEAST TO SOUTHEAST IN DIRECTION. IT WILL BE BREEZY AT
TIMES IN AND AROUND THE MOUNTAINS...INCLUDING LARAMIE THIS
AFTERNOON. LEFT IN VICINITY SHOWERS FOR ALL BUT THE WESTERN
AIRFIELDS FOR THIS AFTERNOON. BOTH THE NAM AND SREF MODEL GUIDANCE
LOWER CEILINGS TO MVFR THIS EVENING AT LARAMIE AND CHEYENNE...WITH
MVFR VISIBILITY IN FOG TOWARD THE PREDAWN HOURS. CEILINGS AT
SCOTTSBLUFF AND SIDNEY WILL LOWER TO AROUND 5000 FT AGL BY
SUNRISE.
FIRE WEATHER...
NO CONCERNS ANTICIPATED THROUGH THE WEEKEND WITH MILD TEMPERATURES
SATURDAY AND A LITTLE WARMER FOR SUNDAY. A COUPLE OF WEAK
THUNDERSTORMS ARE POSSIBLE SATURDAY AFTERNOON OVER THE SOUTHERN
MOUNTAINS. DRY AND WARMER WEATHER WILL RETURN FOR EARLY NEXT
WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL 9 AM SATURDAY FOR WYZ116-WYZ117.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...RE
LONG TERM/AVIATION...JAMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
637 PM MDT FRI MAY 11 2012
.UPDATE...BASED ON WSR-88D REFLECTIVITY IMAGES FROM CHEYENNE...
GRAND JUNCTION...RIVERTON...RAPID CITY...NORTH PLATTE AND DENVER
(FRONT RANGE)...HAVE REMOVED EVENING SHOWER CHANCES FROM THE
GRIDDED FORECASTS. ALSO ADJUSTED CLOUD COVER GRIDS TO ADJUST
FOR CURRENT CLOUD COVER SOUTH OF A LARAMIE TO CHADRON LINE AND
EXPECTED CLOUD COVER OVERNIGHT. UPDATES HAVE BEEN SENT. RUBIN
&&
.PREV DISCUSSION... /ISSUED 526 PM MDT FRI MAY 11 2012/
AVIATION...00Z TAFS
FAVORABLE WIND DIRECTION FOR MARGINAL CONDITIONS AT
CHEYENNE...LARAMIE AND SIDNEY. HRRR GUIDANCE SHOWING IFR
CONDITIONS DEVELOPING AT THESE LOCATIONS OVERNIGHT...CONTINUING
INTO SATURDAY MORNING. WILL NEED TO MONITOR CLOSELY THIS EVENING.
DOUBTS ARE THERE THAT WE HAVE SUFFICIENT LOW LEVEL MOISTURE TO
SUSTAIN THESE LOW CONDITIONS.
CLAYCOMB
PREV DISCUSSION... /ISSUED 311 PM MDT FRI MAY 11 2012/
SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...
WIDELY SCATTERED SHOWERS NOW CONFINED TO MAINLY THE SOUTHEAST PART
OF THE NEBRASKA PANHANDLE AS WELL AS OVER THE HIGHER MOUNTAINS
CLOSE TO THE COLORADO BORDER. EXPECT THESE TO MOVE EAST AND PRETTY
MUCH OUT OF THE CWA BY EARLY THIS EVENING. COOL CONDITIONS WILL
CONTINUE ESPECIALLY OVER THE PLAINS TONIGHT AND SATURDAY AS SFC
HIGH SLOWLY SLIDES EAST OVER THE CENTRAL PLAINS. EXPECT SOME
WIDELY SCATTERED SHOWERS ALONG WITH A WEAK STORM OR TWO TO DEVELOP
MAINLY OVER THE MTNS SATURDAY AFTERNOON AS SOME MOISTURE INTERACTS
WITH AN APPROACHING SHORTWAVE DROPPING ACROSS THE NORTHERN ROCKIES.
SHOWERS SHOULD PERSIST INTO SATURDAY EVENING AS THE WAVE MOVES
ACROSS THEN DRIER AND A LITTLE WARMER SUNDAY BEHIND THE SHORTWAVE.
LONG TERM...MONDAY THROUGH FRIDAY...
THE 12Z SHORT RANGE MODELS HAVE NOT CHANGED MUCH FROM THE PREVIOUS
FEW FORECAST CYCLES. MONDAY AND TUESDAY WILL BE INFLUENCED BY A
RIDGE OF HIGH PRESSURE AT THE SURFACE AND ALOFT. INSTABILITY AND
MOISTURE WILL BE NEGLIGIBLE BOTH DAYS...THEREFORE NO SENSIBLE
WEATHER AND LIGHT WINDS ARE FORECAST. THEN THE MODELS HANDLE THE
CLOSED UPPER LOW MOVING FROM NORTHERN CALIFORNIA THROUGH THE GREAT
BASIN DIFFERENTLY. THE GFS/ECMWF TRANSITION THE LOW INTO A
SHORTWAVE TROUGH ON WEDNESDAY AS IT APPROACHES THE CENTRAL
ROCKIES. THE GEM-NHEM IS SLIGHTLY DEEPER AND SLOWER WITH THIS
FEATURE. DESPITE MARGINAL INSTABILITY OVER THE CWA...LIFT AND
MOISTURE FOR ISOLATED AFTERNOON CONVECTION WILL BE RELEGATED TO
THE HIGHER TERRAIN IN COLORADO. FLOW ALOFT THURSDAY WILL BE
ZONAL...THEN TRANSITION TO SOUTHWEST ON FRIDAY IN ADVANCE OF THE
NEXT SHORTWAVE TROUGH TO THE WEST. LIFT FROM A WEAK WAVE
TRANSLATING EAST ACROSS WYOMING THURSDAY MAY BE SUFFICIENT TO
TRIGGER ISOLATED AFTERNOON CONVECTION OVER THE HIGHER TERRAIN IN
SOUTHEAST WYOMING. FRIDAY APPEARS DRY FOR NOW AS A RIDGE BUILDS
OVER THE HIGH PLAINS. EXPECT BREEZY CONDITIONS WEDNESDAY THROUGH
FRIDAY WEST OF THE LARAMIE RANGE...MAINLY DURING THE DAYLIGHT
HOURS. TEMPERATURES EACH DAY WILL AVERAGE ABOVE SEASONAL
NORMALS...WITH THE WARMEST DAY ON WEDNESDAY.
AVIATION...18Z TAF ISSUANCE...
VFR CEILINGS BETWEEN 5000 AND 10000 FEET AGL WILL PREVAIL FOR
MOST AREA AIRFIELDS THROUGH THE AFTERNOON. SURFACE WINDS WILL VARY
FROM NORTHEAST TO SOUTHEAST IN DIRECTION. IT WILL BE BREEZY AT
TIMES IN AND AROUND THE MOUNTAINS...INCLUDING LARAMIE THIS
AFTERNOON. LEFT IN VICINITY SHOWERS FOR ALL BUT THE WESTERN
AIRFIELDS FOR THIS AFTERNOON. BOTH THE NAM AND SREF MODEL GUIDANCE
LOWER CEILINGS TO MVFR THIS EVENING AT LARAMIE AND CHEYENNE...WITH
MVFR VISIBILITY IN FOG TOWARD THE PREDAWN HOURS. CEILINGS AT
SCOTTSBLUFF AND SIDNEY WILL LOWER TO AROUND 5000 FT AGL BY
SUNRISE.
FIRE WEATHER...
NO CONCERNS ANTICIPATED THROUGH THE WEEKEND WITH MILD TEMPERATURES
SATURDAY AND A LITTLE WARMER FOR SUNDAY. A COUPLE OF WEAK
THUNDERSTORMS ARE POSSIBLE SATURDAY AFTERNOON OVER THE SOUTHERN
MOUNTAINS. DRY AND WARMER WEATHER WILL RETURN FOR EARLY NEXT
WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...RE
LONG TERM/AVIATION...JAMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
526 PM MDT FRI MAY 11 2012
.AVIATION...00Z TAFS
FAVORABLE WIND DIRECTION FOR MARGINAL CONDITIONS AT
CHEYENNE...LARAMIE AND SIDNEY. HRRR GUIDANCE SHOWING IFR
CONDITIONS DEVELOPING AT THESE LOCATIONS OVERNIGHT...CONTINUING
INTO SATURDAY MORNING. WILL NEED TO MONITOR CLOSELY THIS EVENING.
DOUBTS ARE THERE THAT WE HAVE SUFFICIENT LOW LEVEL MOISTURE TO
SUSTAIN THESE LOW CONDITIONS.
CLAYCOMB
&&
.PREV DISCUSSION... /ISSUED 311 PM MDT FRI MAY 11 2012/
SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...
WIDELY SCATTERED SHOWERS NOW CONFINED TO MAINLY THE SOUTHEAST PART
OF THE NEBRASKA PANHANDLE AS WELL AS OVER THE HIGHER MOUNTAINS
CLOSE TO THE COLORADO BORDER. EXPECT THESE TO MOVE EAST AND PRETTY
MUCH OUT OF THE CWA BY EARLY THIS EVENING. COOL CONDITIONS WILL
CONTINUE ESPECIALLY OVER THE PLAINS TONIGHT AND SATURDAY AS SFC
HIGH SLOWLY SLIDES EAST OVER THE CENTRAL PLAINS. EXPECT SOME
WIDELY SCATTERED SHOWERS ALONG WITH A WEAK STORM OR TWO TO DEVELOP
MAINLY OVER THE MTNS SATURDAY AFTERNOON AS SOME MOISTURE INTERACTS
WITH AN APPROACHING SHORTWAVE DROPPING ACROSS THE NORTHERN ROCKIES.
SHOWERS SHOULD PERSIST INTO SATURDAY EVENING AS THE WAVE MOVES
ACROSS THEN DRIER AND A LITTLE WARMER SUNDAY BEHIND THE SHORTWAVE.
LONG TERM...MONDAY THROUGH FRIDAY...
THE 12Z SHORT RANGE MODELS HAVE NOT CHANGED MUCH FROM THE PREVIOUS
FEW FORECAST CYCLES. MONDAY AND TUESDAY WILL BE INFLUENCED BY A
RIDGE OF HIGH PRESSURE AT THE SURFACE AND ALOFT. INSTABILITY AND
MOISTURE WILL BE NEGLIGIBLE BOTH DAYS...THEREFORE NO SENSIBLE
WEATHER AND LIGHT WINDS ARE FORECAST. THEN THE MODELS HANDLE THE
CLOSED UPPER LOW MOVING FROM NORTHERN CALIFORNIA THROUGH THE GREAT
BASIN DIFFERENTLY. THE GFS/ECMWF TRANSITION THE LOW INTO A
SHORTWAVE TROUGH ON WEDNESDAY AS IT APPROACHES THE CENTRAL
ROCKIES. THE GEM-NHEM IS SLIGHTLY DEEPER AND SLOWER WITH THIS
FEATURE. DESPITE MARGINAL INSTABILITY OVER THE CWA...LIFT AND
MOISTURE FOR ISOLATED AFTERNOON CONVECTION WILL BE RELEGATED TO
THE HIGHER TERRAIN IN COLORADO. FLOW ALOFT THURSDAY WILL BE
ZONAL...THEN TRANSITION TO SOUTHWEST ON FRIDAY IN ADVANCE OF THE
NEXT SHORTWAVE TROUGH TO THE WEST. LIFT FROM A WEAK WAVE
TRANSLATING EAST ACROSS WYOMING THURSDAY MAY BE SUFFICIENT TO
TRIGGER ISOLATED AFTERNOON CONVECTION OVER THE HIGHER TERRAIN IN
SOUTHEAST WYOMING. FRIDAY APPEARS DRY FOR NOW AS A RIDGE BUILDS
OVER THE HIGH PLAINS. EXPECT BREEZY CONDITIONS WEDNESDAY THROUGH
FRIDAY WEST OF THE LARAMIE RANGE...MAINLY DURING THE DAYLIGHT
HOURS. TEMPERATURES EACH DAY WILL AVERAGE ABOVE SEASONAL
NORMALS...WITH THE WARMEST DAY ON WEDNESDAY.
AVIATION...18Z TAF ISSUANCE...
VFR CEILINGS BETWEEN 5000 AND 10000 FEET AGL WILL PREVAIL FOR
MOST AREA AIRFIELDS THROUGH THE AFTERNOON. SURFACE WINDS WILL VARY
FROM NORTHEAST TO SOUTHEAST IN DIRECTION. IT WILL BE BREEZY AT
TIMES IN AND AROUND THE MOUNTAINS...INCLUDING LARAMIE THIS
AFTERNOON. LEFT IN VICINITY SHOWERS FOR ALL BUT THE WESTERN
AIRFIELDS FOR THIS AFTERNOON. BOTH THE NAM AND SREF MODEL GUIDANCE
LOWER CEILINGS TO MVFR THIS EVENING AT LARAMIE AND CHEYENNE...WITH
MVFR VISIBILITY IN FOG TOWARD THE PREDAWN HOURS. CEILINGS AT
SCOTTSBLUFF AND SIDNEY WILL LOWER TO AROUND 5000 FT AGL BY
SUNRISE.
FIRE WEATHER...
NO CONCERNS ANTICIPATED THROUGH THE WEEKEND WITH MILD TEMPERATURES
SATURDAY AND A LITTLE WARMER FOR SUNDAY. A COUPLE OF WEAK
THUNDERSTORMS ARE POSSIBLE SATURDAY AFTERNOON OVER THE SOUTHERN
MOUNTAINS. DRY AND WARMER WEATHER WILL RETURN FOR EARLY NEXT
WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...RE
LONG TERM/AVIATION...JAMSKI
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1156 PM CDT FRI MAY 11 2012
.SHORT TERM /TONIGHT/...
THE COLD FRONT WAS ALONG A NEWTON TO LAMONI LINE AT 20Z THIS
AFTERNOON. VISIBLE SATELLITE IMAGERY WAS SHOWING A FEW CU DEVELOPING
NEAR THE BOUNDARY. SURFACE DEW POINTS ALONG AND AHEAD OF THE FRONT
WERE IN THE MID TO UPPER 50S. THE 19Z SPC THERMODYNAMICS FIELDS
SUGGEST MODEST INSTABILITY WITH VERY WEEK MOISTURE CONVERGENCE ALONG
THE FRONT. THROUGH THE EARLY EVENING...EXPECT THE FRONT TO SLOWLY
MOVE SOUTHEAST REACHING DAVIS COUNTY BY 7 PM. 12Z GFS/NAM AND THE
LATEST HRRR DEVELOP SHOWERS OR THUNDERSTORMS NEAR THE FRONT THIS
EVENING. THERE WILL BE ENOUGH INSTABILITY AND LIFT TO KEEP A SMALL
CONDITIONAL CHANCE OF SHOWERS AND THUNDERSTORMS IN THE FORECAST.
WEAK MID LEVEL FORCING AHEAD OF POSITIVELY TILTED 700 MB TROUGH AND
MID-LEVEL MOISTURE MAY BE ADEQUATE TO PRODUCE SCATTERED SHOWERS OVER
SOUTH CENTRAL IOWA TONIGHT ALONG WITH CLOUDINESS. PREVIOUS
TEMPERATURE FORECAST LOOKED GOOD REQUIRING ONLY MINOR ADJUSTMENTS.
.LONG TERM /SATURDAY THROUGH FRIDAY/...
RATHER QUIET PERIOD TO CONTINUE INTO THE WEEKEND AND NEXT WEEK. A
FEW ITEMS TO MENTION INCLUDING COLD FRONTAL BOUNDARY HANGING UP OVER
CENTRAL TO NORTHERN MO ON SATURDAY MAY HAVE ENOUGH ISENTROPIC LIFT
TO KEEP A FEW SHOWERS OVER FAR SOUTHERN IOWA SATURDAY AND SATURDAY
EVENING. CLOUDS WILL ALSO LINGER OVER THE SOUTH ON SATURDAY BUT
SHOULD EXIT THE REGION BY SATURDAY EVENING LEAVING SUNDAY MAINLY
SUNNY AND QUIET. MODEST FLOW REMAINS ACROSS THE NORTHERN TIER STATES
WITH A FEW WAVES TRAVELING ALONG THE US CAN BORDER. A WEAK COOL
FRONT HAS BEEN ADVERTISED TO CROSS THE REGION BY TUESDAY EVENING OR
WEDNESDAY MORNING. THIS WILL ALLOW FOR SLIGHTLY COOLER AIR TO DROP
INTO THE REGION FOR A DAY PRIOR TO THE FRONT LIFTING BACK NORTH BY
WEDNESDAY NIGHT AND THURSDAY. CLIMATOLOGY FAVORS SOME THUNDER
ACTIVITY AS THE FRONT LIFTS NORTH...BUT MODELS REMAIN RATHER DRY AS
FLOW OVER THE SOUTH HAS BEEN SHUT DOWN WITH WEAK LOW PRESSURE AND
NORTHWEST FLOW HUGGING THE GULF COAST. THUS...AM RELUCTANT TO GET
TOO EXCITED ABOUT POP IN THE REMAINDER OF THE EXTENDED PERIOD UNTIL
A STRONGER WAVE DROPS INTO THE WEST. IT APPEARS THAT THE NEXT
OPPORTUNITY FOR THAT WILL COME 24 TO 48 HOURS FOLLOWING THE CURRENT
EXTENDED FORECAST. FORECAST HIGHS WILL WARM NICELY BY THE END OF THE
EXTENDED PERIOD. WITH SW FLOW IN PLACE AND GOOD MIXING COMBINED WITH
H850 TEMPS OF 17-19C...WILL LIKELY SEE HIGHS IN THE MID TO UPPER 80S
IF THE TREND HOLDS. COORD WITH SURROUNDING OFFICES WITH LOWER 80S IN
MIND AND WILL WAIT FOR A FEW MORE CONFIRMATION RUNS PRIOR TO RAISING
TEMPS HIGHER...BUT BOTH H500 PATTERN WITH RIDGE BUILDING OVER THE
LOWER MS RIVER VALLEY AND INCREASING H850 TEMPS SUPPORT VERY WARM
AND INCREASINGLY HUMID AIRMASS NORTH INTO THE REGION. EURO THICKNESS
BY 00Z SAT 5/19 BACK TO 570-573DM WHICH IS RATHER SUMMER LIKE.
&&
.AVIATION...12/06Z
COLD FRONT HAS MOVED PAST KOTM WITH NO PRECIPITATION CURRENTLY IN
THE FORECAST AREA. PRECIP ASSOCIATED WITH SW-NE ORIENTED SIOUXLAND
UPPER SYSTEM HAS DISSIPATED AS WELL. ATTENTION WILL THEN TURN TO OK
UPPER LOW AND SCATTERED SHOWERS ACROSS KS. SHOWERS WITH THIS
SYSTEM MAY MOVE NE AND AFFECT SRN TAF SITES /KDSM/KOTM/ AT ANY TIME
THROUGH 00Z BUT CONFIDENCE IN ANY PARTICULAR LOCATION OR TIMING IS
LOW SO WILL LEAVE DRY INSTEAD OF PROLONGED VCSH MENTION. EVEN IF
PRECIP DOES DEVELOP...EXPECT CONDITIONS TO REMAIN VFR.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...JOHNSON
LONG TERM...REV
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1141 PM CDT FRI MAY 11 2012
.AVIATION...
A COLD FRONT WILL PASS SOUTHEAST OF THE AREA BY 07Z. FOLLOWING
THE FRONTAL PASSAGE BEYOND 10Z...BUT WITH LIMITED COVERAGE ISOLATED
TO SCATTERED AREAS OF LIGHT PRECIPITATION EXPECTED...WILL CONTINUE
VC WORDING FOR SHOWERS THIS MORNING INTO SATURDAY AFTERNOON AND
EVENING AND NOT INCLUDE ANY MENTION OF THUNDER...AT CID...MLI...BRL
TERMINALS. PROB30 GROUP AT BRL TERMINAL WHERE GREATEST RISK OF
SHOWERS LATE MORNING INTO MID AFTERNOON. NORTH WINDS OF 5 TO 12
KTS WILL VEER TO THE NORTHEAST SATURDAY MORNING. VFR FLIGHT RULES
TO PERSIST...WITH A BRIEF PERIOD OF MVFR CIGS POSSIBLE WITH THE
STRONGEST PRECIPITATION SATURDAY MORNING INTO AFTERNOON POSSIBLY
AT BRL TERMINAL. NICHOLS
&&
.PREV DISCUSSION... /ISSUED 312 PM CDT FRI MAY 11 2012/
SYNOPSIS...
MOISTURE STARVED SURFACE COLD FRONT CONTINUES CRAWL SLOWLY ACROSS
IA THIS AFTERNOON...REACHING FROM WEST CENTRAL WI...TROUGH MASON
CITY TO WEST OF DES MOINES...INTO FAR NW MO AT 19Z. VISIBLE
SATELLITE SHOWED MOSTLY CLEAR SKIES OVER THE FORECAST AREA WITH
SIGNIFICANT CLOUD COVER NEAR THE BOUNDARY LIMITED TO MN AND
WI...WHILE POST FRONTAL CLOUDS ASSOCIATED WITH HIGHER MOISTURE AND
MID AND UPPER LEVEL FORCING WERE WELL TO THE NW FROM NW NEB
THROUGH SE SD INTO MN. AREA RADAR MOSAIC INDICATED A BAND OF
SHOWERS WELL BEHIND THE FRONT FROM W CENTRAL MN INTO N CENTRAL
NEB. ISOLATED HIGH BASED SHOWERS WERE BEGINNING TO POP UP IN W
CENTRAL AND NW IA OVER THE PAST HOUR. TEMPERATURES WERE INTO THE
UPPER 70S TO LOWER 80S OVER THE FORECAST AREA...WHILE UPPER 60S TO
LOWER 70S WERE FOUND WEST OF THE BOUNDARY ACROSS WESTERN IA AND SW
MN.
SHORT TERM...TONIGHT AND SATURDAY...
PRIMARY CHALLENGE IS RAIN CHANCES AS THE COLD FRONT PUSHES THROUGH
THE AREA TONIGHT INTO SATURDAY. WITH GULF MOISTURE RATHER MEAGER AND
LIMITED BY A LOW MOVING ACROSS TX TODAY...SURFACE DEWPOINTS HAVE
ONLY REACHED A NARROW AXIS OF MID 50S AHEAD OF THE FRONT...AND 850
MB ANALYSIS FROM THIS MORNING WOULD SUGGEST BULK OF GULF MOISTURE TO
REMAIN CUTOFF IN THE SOUTHERN PLAINS. CLOSE INSPECTION OF THE LATEST
VISIBLE SATELLITE SHOWS THE FIRST CU OF THE DAY STARTING TO POP
ALONG THE BOUNDARY NEAR DSM...AND WILL WATCH THIS DEVELOPMENT ALONG
AND AHEAD OF THE FRONT FOR POSSIBLE SHOWERS AND THUNDERSTORMS THIS
AFTERNOON AS MUCAPES RISE TO VALUES WELL BELOW 1000 J/KG.
OTHERWISE...IT LOOKS LIKE THE BETTER FORCING FOR SHOWERS TONIGHT
WILL MORE CLOSELY TIED TO THE WEAK FORCING AND MOISTURE AROUND 700
MB ASSOCIATED WITH THE CURRENT AXIS OF POST FRONTAL SHOWERS. THIS
FEATURE FOLLOWS THE FRONT INTO THE FORECAST AREA LATER THIS EVENING
AND OVERNIGHT AND WILL KEEP CHANCE POPS IN PLACE. WILL KEEP AN
MENTION OF ISOLATED THUNDERSTORMS FOR THE EVENING FOR THE POSSIBLE
DEVELOPMENT OF CONVECTION ALONG THE ADVANCING BOUNDARY...WHICH IS
STILL SUGGESTED AS POSSIBILITY BY THE HRRR MODEL. OTHERWISE...
INCREASING CLOUD COVER WILL OFFSET THE LOW LEVEL COLD AIR ADVECTION
BEHIND THE WEAKENING COLD FRONT AND LIMIT LOWS TO AROUND 50 NORTH TO
THE MID 50S SOUTH.
SATURDAY...THE FRONT CONTINUES TO WEAKEN AND SLOW AS IT DROPS TOWARD
THE UPPER LEVEL SYSTEM MOVING THROUGH THE MID MS VALLEY. WEAK MID
LEVEL FORCING AND MOISTURE IS SHOWN POOLING NORTH OF THE BOUNDARY
THROUGH AT LEAST THE MORNING HOURS TO JUSTIFY CHANCE POPS FOR LIGHT
RAIN SHOWERS. THIS THEN SHIFTS TO THE FAR SOUTH IN THE AFTERNOON AS
SURFACE HIGH PRESSURE BUILDS OVER THE NORTHERN PLAINS INTO THE UPPER
MS VALLEY...INCREASING THE LOW LEVEL FLOW OF DRY AIR INTO THE AREA.
LINGERING MID AND HIGH LEVEL MOISTURE AND WEAK FORCING EMBEDDED IN
THE MID LEVEL CYCLONIC FLOW TO THE NORTH WILL LIKELY KEEP SKIES
MOSTLY CLOUDY AND WILL LIMIT HIGHS TO THE 60S OVER MOST OF THE
AREA. SHEETS
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
MAIN FOCUS THIS FORECAST TIME RANGE IS ON PRECIPITATION CHANCES
SATURDAY NIGHT AND AGAIN WEDNESDAY THROUGH FRIDAY.
SATURDAY NIGHT AND SUNDAY THE COLD FRONT CONTINUES TO SAG SOUTH. THE
850MB BOUNDARY REMAINS IN THE AREA SATURDAY NIGHT AND A WEAK VORT
MAX WILL DROP SOUTH ACROSS THE AREA. THIS MAY PRODUCE SOME ELEVATED
SHOWERS SATURDAY NIGHT...MAINLY IN THE EVENING. MOISTURE IS A
LIMITING FACTOR SO HAVE KEPT PRECIPITATION CHANCES IN THE SLIGHT
CHANCE CATEGORY. TEMPERATURES TO BE MILD BOTH PERIODS WITH CLOUDS
TEMPERING THE COOLER AND DRIER AIR COMING IN FROM THE NORTH. MINS
SATURDAY NIGHT IN THE 40S AND LOW 50S. HIGHS SUNDAY TO BE IN THE
LOW 70S.
MONDAY AND TUESDAY A WEAK SURFACE RIDGE TO BUILD SOUTH ACROSS THE
AREA WITH WEAK WESTERLY RETURN FLOW SETTING UP FOR TUESDAY. THIS
WILL ALLOW TEMPERATURES TO RISE SO THAT ON TUESDAY WE WILL HAVE
HIGHS IN THE UPPER 70S AGAIN...POSSIBLY EVEN SOME MORE LOW 80S.
FORECAST HIGHS MAY NEED TO BE RAISED IF IT STILL APPEARS WE WILL BE
WORKING WITH VERY DRY AIR AND DEEP MIXING.
WEDNESDAY THROUGH FRIDAY THE SURFACE RIDGE SLIPS OFF TO THE
SOUTHEAST AND SOUTHWEST RETURN FLOW SETS IN IN EARNEST WITH A LONG
FETCH FROM TEXAS...AND BY FRIDAY IT APPEARS THAT THERE WILL BE
STREAM OF GULF MOISTURE HEADING OUR DIRECTION. A FAIRLY STRONG
UPPER LEVEL SYSTEM OVER CANADA WILL PUSH A COLD FRONT TOWARDS THE
AREA WEDNESDAY. THIS FRONT MAY DROP INTO THE AREA WEDNESDAY...
THOUGH THERE IS SOME MODEL DISAGREEMENT HERE...WITH SOME KEEPING IT
NORTH OF THE AREA. FOR NOW HAVE KEPT THE FORECAST DRY AS THERE IS
LITTLE MOISTURE AVAILABLE FOR THIS BOUNDARY TO WORK WITH. A SURFACE
LOW IS GENERATED OVER WESTERN KANSAS...AND BY THURSDAY AND FRIDAY
THE FRONT BECOMES A WARM FRONT AND PUSHES BACK NORTH...AND WILL BE
GENERALLY DRAPED FROM SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND
INTO WISCONSIN. UNLESS THIS CHANGES THIS IS LIKELY TO BE THE STORM
TRACK NEXT WEEK...AND WE WILL BE SITTING IN A VERY WARM AND
INCREASINGLY HUMID AIRMASS BOTH DAYS...WITH HIGHS INTO THE LOW 80S.
HAVE SOME VERY LOW END CHANCE POPS IN THE FORECAST...BUT UNLESS THE
FRONT SHIFTS CLOSER TO THE AREA AM ANTICIPATING WE WILL BE DRY.
LE
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
NICHOLS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
302 AM MDT SAT MAY 12 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 259 AM MDT SAT MAY 12 2012
230Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED CLOSE LOW
CIRCULATION ACROSS THE SOUTHERN PLAINS WITH LARGE TROUGH ACROSS THE
NORTHERN PLAINS WITH AN EMBEDDED SHORT WAVE TROUGH MOVING INTO
WESTERN COLORADO. AT THE SURFACE 1028MB SFC HIGH WAS BUILDING OVER
THE AREA BEHIND FRONTAL ZONE WHICH WAS DRAPED FROM SOUTHEAST
COLORADO INTO NW MISSOURI. 00Z RAOBS...ESPECIALLY AT KLBF AND KDNR
INDICATED A FAIRLY DEEP FRONT IN PLACE WITH FRONTAL INVERSION ENDING
AROUND 725 MB AND 675MB RESPECTIVELY. ALTHOUGH FAIRLY DRY AIR WAS
LOCATED BELOW INVERSION AT LBF...PARCELS LIFTED FROM TOP OF
INVERSION DID INDICATE SOME VERY WEAK CAPE PRESENT.
PRECIP CHANCES THIS MORNING THROUGH THE REST OF THE WEEKEND WILL BE
PRIMARY NEAR TERM CONCERNS.
TODAY...ONGOING LIGHT PRECIPITATION WILL BE PRIMARY FORECAST
CHALLENGE THIS MORNING AND WITH TEMPERATURES DROPPING INTO THE 30S
AND WBZ HEIGHTS FALLING TO AROUND 1500FT WOULD NOT RULE OUT A FEW
SNOW FLAKES MIXING IN WITH THE PRECIPITATION IN WESTERN CWA THIS
MORNING...BUT IF IT DOES OCCUR DO NOT THINK IT WILL AMOUNT TO MUCH
WITH SOIL TEMPS WELL ABOVE FREEZING. AREA OF LIGHT PRECIPITATION
WILL GRADUALLY SHIFT TO THE EAST THIS MORNING IN AREA OF WEAK
ISENTROPIC ASCENT AND H7 FRONTOGENESIS. INITIALLY THOUGHT THIS WOULD
BE THE ONLY AREA OF PRECIPITATION...BUT LOOKING UPSTREAM STARTING TO
SEE REDEVELOPMENT OF PRECIPITATION IN AREA THAT LOOKS TO BE DIRECTLY
AHEAD OF WEAK SHORT WAVE TROUGH AS PER WV IMAGERY AND RUC PV
ANALYSIS. TIMING THIS FEATURE PUTS IT OVER NORTHERN CWA BY
15Z...WHICH IS CONSISTENT WITH TIMING OF PRECIP AMONGST VARIOUS
MODELS AND SREF DATA AND HAVE MODIFIED FORECAST TO ACCOUNT FOR THIS
TIMING. THINK PRECIP THREAT WILL END FAIRLY QUICKLY AS THIS TROUGH
PASSES AND THINK WE WILL SEE A PERIOD OF NO PRECIPITATION ACROSS THE
CWA AROUND 21Z. FOR ACTUAL PROBABILITY VALUES...GIVEN A LARGE DEGREE
OF SPREAD IN ACTUAL PLACEMENT OF PRECIP MAXIMA AND SURPRISINGLY LOW
PROBABILITIES OF 0.05 OR GREATER FROM THE GEFS DATA AM A LITTLE
HESITANT TO GO TOO HIGH ON POPS...BUT THINK A GENERAL 30-50% CHANCE
IS WARRANTED FOR A GOOD PORTION OF THE AREA. THE ACTUAL MAGNITUDE OF
POPS WILL DEPEND STRONGLY ON BEHAVIOR OF UPSTREAM PRECIP OVER THE
NEXT FEW HOURS.
TONIGHT-SUNDAY...BRIEF PERIOD OF SUBSIDENCE WILL OVERSPREAD THE AREA
AT THE START OF THE PERIOD AS INITIAL SHORT WAVE TROUGH MOVES TO THE
EAST OF THE AREA....BEFORE NEXT TROUGH BEGINS TO DIVE INTO COLORADO
THROUGH THE OVERNIGHT HOURS. SUBSIDENCE DOES NOT LOOK ALL THAT
STRONG AT THIS POINT BUT DEFINITELY THINK LOWEST CHANCES FOR RAIN WILL
BE IN THE EARLY EVENING. MODELS HAVE HAD A BIT OF DIFFICULTY WITH
THE HANDLING OF THIS SYSTEM...JUMPING FROM VERY WET TO DRY SOLUTIONS
OVER THE PAST SEVERAL RUNS SO OVERALL CONFIDENCE IS NOT THAT HIGH.
LARGE SCALE FORCING FOR ASCENT WILL INCREASE THROUGH THE NIGHT WITH
STRONGEST VALUES BETWEEN 9Z AND 18Z SUNDAY...WITH SYNOPTIC SCALE
FORCING MAXIMIZED OVER COLORADO AND CWA REALLY ON THE FRINGE OF
STRONGEST FORCED ASCENT. APPEARS TO BE A WINDOW WITH STRONG H7 TO H5
FRONTOGENESIS DEVELOPING ACROSS THE SOUTHWESTERN CWA...BUT HAVE SOME
CONCERNS THAT A LOT OF THIS FORCING IS SOMEWHAT DUE TO CONVECTIVE
FEEDBACK ESPECIALLY ON THE GFS WHICH SEEMS TO DEVELOP SMALL LOW
CIRCULATION OVERNIGHT SATURDAY WHICH MAXIMIZES FORCING. VERY HIGH
QPF FIELDS IN SPITE OF MINIMAL INSTABILITY ALSO MAKE ME THINK THAT
THERE IS SOME FEEDBACK ISSUES AT PLAY WITH THE BULLS EYE OF ASCENT.
WITH THAT IN MIND...DO NOT WANT TO RAMP UP POPS/QPFS AT THIS TIME
DUE TO LOW CONFIDENCE IN THE PREDICTABILITY OF THESE FEATURES...BUT
FEEL 30-50% POPS WARRANTED FOR THE TIME BEING. WITH VERY LITTLE IF
ANY ELEVATED CAPE HAVE DECIDED TO KEEP WX GROUPS AS JUST RAIN.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 259 AM MDT SAT MAY 12 2012
SUNDAY NIGHT-MONDAY NIGHT...QUIETER WEATHER EXPECTED THROUGH THE
PERIOD AS MAJORITY OF OPERATIONAL DATA SUGGEST SHORT WAVE RIDGING
BUILDING OVER THE THE AREA THROUGH THE REST OF THE PERIOD BEHIND
DEPARTING TROUGH WITH SUBSIDENCE/DRYING QUICKLY BRINGING AN END TO
ANY PRECIP THREAT ACROSS THE AREA. MAIN FOCUS WILL BE HOW QUICKLY
TEMPERATURES RECOVER THROUGH THE PERIOD. GENERAL WARMING TREND LOOKS
TO BE IN ORDER...BUT GIVEN SOME MUCH COLDER DATA IN SREF PLUMES AM A
LITTLE HESITANT TO WARM THINGS TOO MUCH AT THIS POINT.
THE REGION WILL BE UNDER THE EASTERN PORTION OF AN UPPER LEVEL RIDGE
OF HIGH PRESSURE AT THE BEGINNING OF THE PERIOD...WITH DRY
CONDITIONS EXPECTED THROUGH DAYTIME WEDNESDAY. A SHORTWAVE TROUGH
WILL APPROACH THE REGION ON WEDNESDAY NIGHT AND MOVE OVER THE REGION
DURING THE DAYTIME ON THURSDAY. GIVEN THE INSTABILITY EXPECTED
DURING THIS PERIOD...HAVE INCLUDED MENTION OF THUNDERSTORMS WITH THE
SLIGHT CHANCE OF PRECIPITATION...THOUGH CONVECTIVE INHIBITION IS
STILL FAIRLY STRONG OVER MUCH OF THE AREA DURING THIS TIME. THE
UPPER LEVEL FLOW WILL BEGIN TO BECOME MORE ZONAL BY THE END OF THE
PERIOD AS THE UPPER RIDGE MOVES EASTWARD...AND ANOTHER SHORTWAVE
TROUGH BEGINS TO APPROACH THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1013 PM MDT FRI MAY 11 2012
PERSISTENT AREA OF RAIN SHOWERS IN NORTHEAST COLORADO WILL
GRADUALLY WORK INTO NORTHWEST KANSAS AND SOUTHWEST NEBRASKA
OVERNIGHT AND INTO SATURDAY MORNING. CURRENT RADAR TRENDS AND
LATEST MODEL GUIDANCE SUGGEST AN INCREASING RISK OF MVFR CEILINGS
AND LIGHT RAIN AT KGLD DURING THAT TIME PERIOD. ACTIVITY WILL
PROBABLY STAY WEST OF KMCK BUT WILL GET CLOSE THERE AS WELL. BY
SATURDAY AFTERNOON SHOWERS EXPECTED TO END AND CEILINGS IMPROVE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...JRM/CJS
AVIATION...024
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
516 AM EDT SAT MAY 12 2012
.SYNOPSIS...
ISSUED AT 514 AM EDT SAT MAY 12 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
N CNTRL CANADA THROUGH MANITOBA AND NW ONTARIO INTO THE NRN PLAINS.
A PROMINENT SHORTWAVE TROUGH WAS MOVING THROUGH NRN ONTARIO TOWARD
JAMES BAY WHILE A WEAKER TRAILING SHRTWV WAS SLIDING THROUGH NRN MN.
AT THE SFC...A COLD FRONT EXTENDED FROM LOW PRES NEAR JAMES BAY
THROUGH NRN LOWER MI. -SHRA SUPPORTED BY 850-700 MB FGEN BEHIND THE
FRONT OVER CNTRL UPPER MI WERE QUICKLY DIMINISHING AND MOVING OUT OF
THE CWA. IR LOOP SHOWED CONSIDERABLE MID CLOUDS OVER THE REGION WITH
CLEARING WEST OF LAKE SUPERIOR.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 514 AM EDT SAT MAY 12 2012
TODAY...EXPECT ANY LINGERING LIGHT SHOWERS OR SPRINKLES TO EXIT THE
CWA BY DAYBREAK. SATELLITE TRENDS AND MODELS MID LEVEL RH FCST
SUGGEST THAT SKIES SHOULD CLEAR OVER THE WEST THIS MORNING AND OVER
THE SOUTHEAST EARLY THIS AFTERNOON AS THE SFC RIDGE BUILDS INTO THE
REGION. A VERY DRY AIRMASS WILL SPREAD THROUGH UPPER MI WITH PWAT
VALUES DROPPING TO NEAR 0.20 INCHES (30-35 PERCENT OF NORMAL).
PLENTY OF SUNSHINE AND STRONG MIXING DURING THE AFTERNOON PUSHING
INLAND TEMPS INTO THE MID 60S...WILL DROP RH VALUES TO AROUND 20
PERCENT. HOWEVER...NW WINDS ONLY TO AROUND 10 MPH WILL MITIGATE FIRE
WX CONCERNS.
TONIGHT...EVEN THOUGH THE HIGH AND DRIEST AIR WILL SAG TO THE
SOUTH...FAVORABLE RADIATIONAL COOLING CONDITION SHOULD ALLOW TEMPS
TO DROP TOWARD THE LOWER END OF GUIDANCE VALUES WITH INLAND READINGS
INTO THE LOWER 30S.
SUNDAY...WAA WITH INCREASING WRLY FLOW WILL PUSH TEMPS BACK ABOVE
NORMAL WITH HIGHS IN TO THE LOWER 70S AND COOLER READINGS IN THE 60S
ONLY NEAR LAKE MICHIGAN. EVEN WITH A SLIGHT INCREASE IN LOW LEVEL
MOISTURE...RH VALUES ARE EXPECTED TO FALL INTO THE 20-25 PERCENT
RANGE...LEADING TO CONTINUED ELEVATED FIRE DANGER.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 514 AM EDT SAT MAY 12 2012
THE PERIOD STARTS 00Z MON WITH AN AMPLIFIED 500MB RIDGE OVER THE WRN
CONUS...AND A TROUGH FROM A CLOSED UPPER LOW OVER HUDSON BAY TO THE
LOWER MISSISSIPPI VALLEY. LOW LEVEL FLOW WILL BE FROM THE WSW AS THE
CWA WILL BE BETWEEN A SFC LOW OVER HUDSON BAY AND SFC RIDGING FROM
THE CENTRAL PLAIN STATES TO LAKE HURON. WARM AIR WILL BE SPILLING IN
FROM THE W...WITH 850MB TEMPS AROUND 7C OVER ERN UPPER MI...AND
AROUND 11C OVER WRN LAKE SUPERIOR. A SHORTWAVE TROUGH MOVING OVER
WILL HAVE LITTLE MOISTURE TO WORK WITH...AND WILL JUST INCREASE
CLOUD COVER.
MONDAY...LOOK FOR WARM TEMPERATURES AS 850MB TEMPS INCREASE TO A CWA
AVG TEMP OF AROUND 11C. MODELS FORECAST SOUNDINGS INDICATE POTENTIAL
FOR MIXING UP TO 700MB...PRODUCING HIGH TEMPS IN THE 70S. THIS WILL
ALSO LEAD TO LOW DEW PTS...BUT WINDS WILL BE FAIRLY LIGHT WHICH WILL
HELP REDUCE FIRE WX CONCERNS.
TUESDAY LOOKS A BIT COOLER...ESPECIALLY NEAR LAKE SUPERIOR...AS
MODELS SHOW A COLD FRONT MOVING ACORSS THE AREA. 850MB TEMPS ONLY
DROP DOWN TO A CWA AVG OF 9C...BUT THE NWLY WIND WILL KEEP LOCATIONS
NEAR LAKE SUPERIOR COOLER. 12Z/11 ECMWF AND 12Z/11 GEM SHOW LIGHT
PRECIP ACCUMULATIONS OF A COUPLE TENTHS OF A INCH /AT MOST/...WHILE
THE 00Z/12 GFS KEEPS MOST OF THE AREA DRY WITH THE FRONTAL PASSAGE.
THE AIRMASS LOOKS DRY ENOUGH TO KEEP WIDESPREAD PRECIP AT BAY...BUT
SOME CONVECTION COULD BREAK OUT INLAND AS THE FRONT PASSES. NOT
CONFIDENT ENOUGH WITH PRECIP CHANCES TO GO WITH ANY POPS ABOVE LOW
CHANCE.
A SHORTWAVE TROUGH LOOKS TO DIVE OVER OR E OF THE CWA WED...BUT
MODELS VARY ON THE TRACK...AND THEREFOR THE LOCATION OF ANY
PRECIPITATION FROM THE SYSTEM. MODELS ARE IN BETTER AGREEMENT ON WED
BEING A GOOD DEAL COLDER THAN TUE...AS 850MB TEMPS ARE 5-8 DEGREES
COLDER. WITH UNCERTAINTY ON THE TRACK OF THE SHORTWAVE...WILL USE A
CONSENSUS OF GUIDANCE.
FOR THURSDAY AND FRIDAY...MODELS ARE IN GENERAL AGREEMENT IN
BRINGING THE RIDGE ORIGINALLY OVER THE WRN CONUS OVER THE CWA THU
INTO FRI. LOW LEVEL FLOW SHOULD GENERALLY BE FROM THE S...WITH SFC
TEMPS ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 121 AM EDT SAT MAY 12 2012
EXPECT ANY LINGERING -SHRA AT SAW TO END SHORTLY AFTER TAF ISSUANCE
WITH THE ARRIVAL OF DRIER AIR ASSOCIATED WITH HI PRES MOVING EWD
FROM THE PLAINS. THIS HI WL BRING VFR CONDITIONS TO THE AREA TODAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EDT SAT MAY 12 2012
EXPECT NORTHWEST WINDS LATE TONIGHT INTO EARLY THIS MORNING TO
REMAIN AT OR BLO 20 KTS...WITH GUSTS UP TO 25 KTS. WINDS BECOME
SOUTHWESTERLY AND DIMINISH SATURDAY AFTN AND EVENING AND SHOULD
GENERALLY STAY BLO 25 KTS INTO SUNDAY NIGHT WITH THE STRONGEST WINDS
OCCURRING OVER WESTERN LK SUPERIOR IN A SW WIND REGIME. WINDS BECOME
QUITE LIGHT...LESS THAN 15 KTS FOR MOST OF NEXT WEEK AS HIGH
PRESSURE STAYS IN THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KC
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
120 AM EDT SAT MAY 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL SLIDE EAST ACROSS THE REGION TONIGHT BEFORE
PASSING OFFSHORE ON SATURDAY. RETURN SOUTHERLY FLOW AROUND THE
HIGH WILL BRING INCREASING MOISTURE BACK TO THE AREA LATE SATURDAY
THROUGH SUNDAY. A COLD FRONT WILL DRIFT EAST ACROSS THE REGION
SUNDAY NIGHT INTO MONDAY...POSSIBLY RESULTING IN MORE WIDESPREAD
SIGNIFICANT RAINFALL INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1115 PM EDT FRIDAY...
HIGH CLOUDS FANNING OUT AHEAD OF THE DEEPER MOISTURE AXIS TO THE
WEST SHOULD REMAIN QUITE THIN OVERNIGHT GIVEN DRY AIR IN PLACE PER
EVENING RAOBS AND SUBSIDENCE UNDER HIGH PRESSURE. THEREFORE ONLY
MADE SOME SMALL UPWARD TWEAKS TO SKY COVER MAINLY OVER THE WEST
LATE TONIGHT WHEN THE MORE AGGRESSIVE NAM SHOWS A THICKER CANOPY
ARRIVING BY DAYBREAK. OTRW GOING CLEAR TO MOSTLY CLEAR FORECAST ON
TRACK WITH THE BETTER MOISTURE ADVECTION NOT ARRIVING UNTIL LATER
SATURDAY. SHOULD BE ANOTHER RATHER COOL OVERNIGHT PER LOW
DEWPOINTS AND LIGHT WINDS UNDER HIGH PRESSURE PROVIDING GOOD
RADIATIONAL COOLING DESPITE SOME HIGH CLOUDS. LOOKS LIKE SPOTTY 30S
AGAIN VALLEYS WITH SOME PATCHY FROST POSSIBLE MAINLY FAR NW BUT
NOT ENOUGH FOR AN ADVISORY GIVEN BRIEF NATURE AT THIS POINT. OTRW
APPEARS SHOULD SEE MOST OTHER LOCATIONS IN THE 40S BY MORNING SO
BUMPED DOWN LOWS A LITTLE.
PREVIOUS DISCUSSION AS OF 250 PM EDT FRIDAY...
UPPER RIDGE/SFC HIGH PRESSURE WILL SETTLE OVERHEAD TONIGHT.
EXPECT GOOD RADIATIONAL COOLING CONDITIONS UNDER CLEAR SKIES AND
LIGHT WINDS. LOWS WILL RANGE FROM THE UPPER 30S IN THE COLDER VALLEY
TO THE MID 40S IN THE SOUTH.
MOISTURE SLOWLY INCREASES ON SATURDAY AS SURFACE LOW PRESSURE MOVES
INTO THE LOWER MISSISSIPPI VALLEY. WITH POOLING OF MOISTURE AND
UPSLOPE FLOW...ALLOWED FOR SOME LIGHT SHOWERS IN THE SOUTHWEST
MOUNTAINS SATURDAY AFTERNOON. PLAYED HIGH TEMPERATURES SATURDAY
AFTERNOON FROM THE UPPER 60S IN THE MOUNTAINS TO THE MID 70S IN THE
SOUTHEAST.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 230 PM EDT FRIDAY...
DETERIORATING WEATHER CONDITIONS EXPECTED DURING THE SHORT TERM
PERIOD OF THE FORECAST...AS ENERGY FROM SOUTHERN STREAM LOW ACROSS
TEXAS TODAY MERGES WITH A NORTHERN STREAM WAVE MOVING THROUGH THE
GREAT LAKES.
THE FIRST FORECAST CONCERN IS WHEN PRECIP DEVELOPS. THE GFS MOISTENS
THE AIR MASS QUICKLY...INCREASING PWATS TO OVER AN INCH OVER MUCH OF
THE FORECAST AREA BY SUNDAY MORNING. THE NAM IS MUCH SLOWER...BUT
WAS DISREGARDED. WITH THE LOW LEVEL THETA-E RIDGE SNEAKING UP THE
FAR WESTERN PORTION OF THE FORECAST AREA...COMBINED WITH ISENTROPIC
LIFT...KEPT SMALL POPS ACROSS THE FAR WESTERN PORTION OF THE
FORECAST AREA.
ON SUNDAY...WEAK SHORT WAVES BEGIN TO INVADE THE AREA FROM THE
SOUTHWEST IN A DEEP SOUTHWEST FLOW. MOST OF THE PRECIPITATION
SHOULD REMAIN IN THE WESTERN HALF OF THE FORECAST AREA UNDER THE
THETA-E RIDGE.
PRECIP SHOULD EXPAND EAST OF THE BLUE RIDGE BY LATE SUNDAY NIGHT AND
ESPECIALLY MONDAY AS THE SFC COLD FRONT APPROACHES AND LOW LEVEL
WINDS BACK...INCREASING LOW LEVEL CONVERGENCE. PLUS A BROAD AREA OF
UPPER DIVERGENCE FORMS AS OUR FORECAST AREA FALLS UNDER THE RR QUAD
OF NORTHERN STREAM JET.
THIS SPELLS THE POTENTIAL FOR A HEAVY RAIN EVENT ON MONDAY..AS
PWATS INCREASE TO GREATER THAN 2 STANDARD DEVIATIONS ABOVE NORMAL ON
MONDAY...AND WITH GEFS...AND TO LESSER EXTENT...NAEFS HYDROLOGIC
ENSEMBLES SHOWING A SMALL CHANCE SOME RIVER GAUGE LOCATIONS
EXCEEDING ACTION STAGE. THEREFORE...WILL INTRODUCE A MENTION OF THE
THREAT FOR MINOR FLOODING IN THE HWO.
WITH EXTENSIVE CLOUD COVER AND PRECIP EXPANDING IN
COVERAGE...NARROWED THE DIURNAL RANGE IN TEMPS...INCREASING LOWS AND
REDUCING HIGHS...ESPECIALLY MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 230 PM EDT THURSDAY...
AN ACTIVE WEATHER PATTERN IS IN STORE FOR THE EARLY PART OF THE LONG
TERM PERIOD. BOTH THE GFS AND ECMWF PHASE THE SOUTHERN STREAM LOW
CURRENTLY IN TEXAS...WITH A NORTHERN STREAM WAVE MOVING ACROSS THE
GREAT LAKES. THE RESULTS IN A PERSISTENT LONG WAVE TROF ACROSS THE
EASTERN U.S...WITH WAVES OF LOW PRESSURE AT THE SFC RIDING NORTHEAST
ALONG A SLOW MOVING FRONTAL BOUNDARY THROUGH TUESDAY NIGHT AND
POTENTIALLY INTO WEDNESDAY.
THE 00Z ECMWF IS MOST PROGRESSIVE WITH MOVING THE AXIS OF THIS UPPER
TROF TO THE EAST OF OUR AREA WEDNESDAY...WHILE THE 06Z GFS IS MUCH
SLOWER AND DEEPER...WHICH APPEARS TO BE AN OUTLIER WHEN COMPARED TO
ITS ENSEMBLES. A SOLUTION SOMEWHERE BETWEEN IS PROBABLY THE MOST
LIKELY SCENARIO...AS THE ECMWF ENSEMBLE MEAN SUGGESTS. AS A
RESULT...KEPT POPS IN THE FORECAST FOR WEDNESDAY.
LATER THE LONG TERM PERIOD...THE LONG RANGE MODELS DIVERGENCE
CONSIDERABLY ON THE WHAT WILL TRANSPIRE. THE 12Z GFS DEVELOPS A CUT
OFF LOW IN EASTERN NC...WHILE 0Z ECMWF LIFTS THE EASTERN U.S. TROF
WELL AWAY FROM OUR AREA. THE MAJORITY OF THE INDIVIDUAL GFS
ENSEMBLES AGREE WITH THE ECMWF ENSEMBLE MEAN OF KEEPING AN OPEN
UPPER LEVEL TROF OVER THE EASTERN U.S. WITH THE RNK FORECAST AREA
JUST TO THE WEST OF THE UPPER TROF AXIS FROM THE ENSEMBLE
MEANS...WILL KEEP THE FORECAST DRY...BUT CONFIDENCE IS LOW DURING
THIS TIME.
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
AS OF 115 AM EDT SATURDAY...
HIGH CLOUDS SPREAD INTO THE AREA FROM THE WEST TODAY. LOWER LEVELS
OF THE ATMOSPHERE WILL TAKE LONGER TO MOISTEN UP BUT WITH SURFACE
HIGH PRESSURE OFFSHORE A LOWER CEILING...BUT STILL VFR...WILL
DEVELOP THIS EVENING. HIGH CONFIDENCE THAT CONDITIONS WILL REMAIN
VFR THROUGH SUNDAY MORNING.
CEILINGS AND VISIBILITIES WILL LOWER TO MVFR LEVELS AT KBLF AND
KLWB ON SUNDAY THEN ALSO AT ALL OTHER SITES SUNDAY NIGHT THROUGH
TUESDAY AS LOW PRESSURE AND THE ASSOCIATED PRECIPITATION MOVE
EAST. IFR CONDITIONS WILL ALSO BE POSSIBLE ESPCLY ACROSS THE
WESTERN LOCATIONS SUNDAY NIGHT INTO MONDAY IN ASSOCIATION WITH AN
AXIS OF HEAVIER RAINFALL ALONG THE FRONT.
DRIER AIR SHOULD FINALLY WORK IN TUESDAY NIGHT INTO WEDNESDAY
BRINGING A RETURN TO VFR BY MIDWEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/KK
SHORT TERM...PH
LONG TERM...PH
AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
754 AM MDT SAT MAY 12 2012
.UPDATE...
ISSUED AT 754 AM MDT SAT MAY 12 2012
STRATUS SHROUDS THE UPPER GUNNISON VALLEY THIS MORNING...COVERS
BLUE MESA RESERVOIR AND THE TOWN OF GUNNISON. THESE STRATIFORM
CLOUDS WILL LIFT AND DISSIPATE LATER THIS MORNING...THE
TEMPERATURE AND DEW POINT SPREAD OF 7F AT KGUC SUGGESTS THIS WILL
BE SOONER THAN LATER.
THE HRRR SHOWS CONVECTIVE SHOWERS DEVELOPING OVER THE SAN JUAN
MOUNTAINS...BUT NOTABLY DRY OVER THE NORTHERN AND CENTRAL
MOUNTAINS THIS AFTERNOON. MUCH OF THE FORECAST AREA IS IN A DRY
AND SUBSIDENT AIR MASS THIS MORNING...BUT THIS IS ONLY TEMPORARY
AS THE NEXT UPSTREAM SHORT WAVE WILL BE APPROACHING FROM THE
NORTHWEST THIS AFTERNOON. THE FORECAST MAY BE TOO FAST WITH
SHOWERS AND STORMS REDEVELOPING OVER THE NORTHERN MOUNTAINS...WE
WILL TAKE A LOOK AT THE MODEL SUITE TO CHECK WHETHER OTHER MODELS
SHOW THIS SAME TREND.
&&
.SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 311 AM MDT SAT MAY 12
2012
NEXT UPSTREAM PACIFIC SHORTWAVE TROUGH APPARENT ON SATELLITE
IMAGERY IN SOUTHERN IDAHO. AHEAD OF THAT FEATURE...EXPECT CONVECTION
TO DEVELOP AGAIN OVER OUR CWA THIS AFTERNOON MAINLY NEAR THE
CONTINENTAL DIVIDE...THOUGH NOT AS EXTENSIVE AS ON FRIDAY. MAX
TEMPERATURES TODAY LIKELY TO BE A TAD COOLER ACROSS THE SOUTHERN
THIRD OF OUR CWA...AND SIMILAR TO YESTERDAY ACROSS THE REMAINDER
OF OUR CWA.
THE 00Z NAM HAS COME IN STRONGER WITH THE SHORTWAVE TROUGH THAT IS
PROGGED TO DROP SOUTHWARD ACROSS WY SAT NIGHT...AND THEN PROCEED
ACROSS CO/EASTERN UT ON SUNDAY. THIS SOLUTION IS IN BETTER AGREEMENT
WITH THE GFS THAN THE PREVIOUS RUN. AND BOTH MODELS NOW SEEM TO BE
JUST A LITTLE SLOWER IN MOVING THE SYSTEM SOUTHWARD INTO NM...
KEEPING IT OVER AND JUST SOUTH OF OUR SOUTHERN EDGE THROUGH SUN
EVENING.
EXPECT SCATTERED SHOWERS WILL CONTINUE THROUGH SAT NIGHT AS THIS
SHORTWAVE APPROACHES...MAINLY OVER THE EASTERN MOUNTAINS. THEN BY
SUNDAY THE TROUGH WILL MOVE OVERHEAD FOR AN UPTICK OF ACTIVITY
THROUGH THE DAY AND INTO THE EVENING. WHILE THE EASTERN MOUNTAINS
WILL CONTINUE TO BE FAVORED...WILL EXPAND COVERAGE WESTWARD SOMEWHAT
AS THE NAM SHOWS THE 500 MB LOW DROPPING ALONG THE UT/CO BORDER
THROUGH THE DAY. AN EASTERLY OR DOWNSLOPE COMPONENT QUICKLY FOLLOWS
WITH DIMINISHING ACTIVITY FROM THE NORTH BEGINNING BEFORE SUNSET AS
THE TROUGH AXIS MOVES INTO NM. SHOWERS WILL LINGER LONGEST OVER THE
SOUTHERN DIVIDE.
HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND WEST LATE SUN NIGHT
INTO MONDAY. BY MONDAY AFTERNOON THE HIGH PRESSURE RIDGE WILL BE
JUST UPSTREAM...CENTERED OVER UT WITH DRIER AND WARMER CONDITIONS
FOR OUR CWA.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 311 AM MDT SAT MAY
12 2012
MIGRATORY UPPER RIDGE SHOULD BE MOVING ACROSS OUR CWA MONDAY NIGHT
AND TUESDAY WITH RELATIVELY DRY CONDITIONS EXCEPT FOR ISOLATED
CONVECTION OVER THE MOUNTAINS. THEN A PACIFIC SHORTWAVE
DISTURBANCE IS STILL EXPECTED TO DRIFT ACROSS OUR AREA ON
WEDNESDAY...FOLLOWED BY ANOTHER DISTURBANCE ON THURSDAY... WHICH
SHOULD RESULT IN A FEW SHOWERS AND THUNDERSTORMS MAINLY OVER THE
MOUNTAINS. THESE FEATURES SHOULD HAVE MINIMAL IMPACT ON
TEMPERATURES...EXCEPT FOR THE INFLUENCE OF ANY CLOUD COVER.
AN INCREASING SW FLOW ALOFT IS STILL EXPECTED OVER OUR CWA ON
FRIDAY AS THE MODELS ARE INDICATING A MORE SIGNIFICANT SHORTWAVE
TROUGH APPROACHING OUR CWA. PRESENTLY...NEXT FRIDAY APPEARS TO BE
A RATHER DRY DAY FOR OUR CWA WITH BREEZY SOUTHERLY SURFACE WINDS.
MAX TEMPERATURES DURING THIS PERIOD SHOULD BE NEARLY 10 DEGREES
ABOVE NORMAL AT MOST LOCATIONS...WITH MIN TEMPERATURES 5 TO 10
DEGREES ABOVE NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 311 AM MDT SAT MAY 12 2012
EXPECT VFR CONDITIONS ACROSS MOST OF THE AREA TODAY AND
TONIGHT...EXCEPT FOR SOME EARLY MORNING LOW CLOUDS AND MOUNTAIN
OBSCURATION IN THE EXTREME SOUTHERN PART OF WESTERN CO NEAR THE
CONTINENTAL DIVIDE. SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP THIS AFTERNOON MAINLY OVER THE MOUNTAINS OF
WESTERN COLORADO WITH LOCALIZED MOUNTAIN OBSCURATION/MVFR CIGS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...EH
LONG TERM...JRP
AVIATION...JRP
AREA FORECAST DISCUSSION
NWS GOODLAND KS
929 AM MDT SAT MAY 12 2012
.UPDATE...
ISSUED AT 928 AM MDT SAT MAY 12 2012
AM UPDATING FORECAST TO BETTE DEPICT THE AREA OF LIGHT RAIN WITH
A FEW EMBEDDED STRONGER SHOWERS MOVING ACROSS THE FORECAST AREA
THIS MORNING.
UPDATE ISSUED AT 551 AM MDT SAT MAY 12 2012
AREA OF LIGHT RAIN SHOWERS BECOMING FAIRLY WELL ORGANIZED AHEAD OF
SHORT WAVE TROUGH ACROSS THE NORTHERN PART OF CWA...WITH
MEASURABLE PRECIPITATION BEING OBSERVED WITH WEAKER ECHOES
CONFIDENCE HAS INCREASED IN COVERAGE OF MEASURABLE PRECIP. WHILE
THINK GENERAL TIMING OF FORECAST REMAINS OK...DID INCREASE
MAGNITUDE OF POPS 20-30 PERCENT MAINLY ACROSS NORTHERN CWA TO
ACCOUNT FOR CURRENT ACTIVITY. RADAR ECHOES BECOMING BETTER
ORGANIZED TO THE SOUTH AS WELL...BUT SO FAR HAVE NOT SEEN MUCH IN
THE WAY OF -RA IN OBS SO WILL CONTINUE WITH SCATTERED POPS IN THIS
AREA.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 259 AM MDT SAT MAY 12 2012
230Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED CLOSE LOW
CIRCULATION ACROSS THE SOUTHERN PLAINS WITH LARGE TROUGH ACROSS THE
NORTHERN PLAINS WITH AN EMBEDDED SHORT WAVE TROUGH MOVING INTO
WESTERN COLORADO. AT THE SURFACE 1028MB SFC HIGH WAS BUILDING OVER
THE AREA BEHIND FRONTAL ZONE WHICH WAS DRAPED FROM SOUTHEAST
COLORADO INTO NW MISSOURI. 00Z RAOBS...ESPECIALLY AT KLBF AND KDNR
INDICATED A FAIRLY DEEP FRONT IN PLACE WITH FRONTAL INVERSION ENDING
AROUND 725 MB AND 675MB RESPECTIVELY. ALTHOUGH FAIRLY DRY AIR WAS
LOCATED BELOW INVERSION AT LBF...PARCELS LIFTED FROM TOP OF
INVERSION DID INDICATE SOME VERY WEAK CAPE PRESENT.
PRECIP CHANCES THIS MORNING THROUGH THE REST OF THE WEEKEND WILL BE
PRIMARY NEAR TERM CONCERNS.
TODAY...ONGOING LIGHT PRECIPITATION WILL BE PRIMARY FORECAST
CHALLENGE THIS MORNING AND WITH TEMPERATURES DROPPING INTO THE 30S
AND WBZ HEIGHTS FALLING TO AROUND 1500FT WOULD NOT RULE OUT A FEW
SNOW FLAKES MIXING IN WITH THE PRECIPITATION IN WESTERN CWA THIS
MORNING...BUT IF IT DOES OCCUR DO NOT THINK IT WILL AMOUNT TO MUCH
WITH SOIL TEMPS WELL ABOVE FREEZING. AREA OF LIGHT PRECIPITATION
WILL GRADUALLY SHIFT TO THE EAST THIS MORNING IN AREA OF WEAK
ISENTROPIC ASCENT AND H7 FRONTOGENESIS. INITIALLY THOUGHT THIS WOULD
BE THE ONLY AREA OF PRECIPITATION...BUT LOOKING UPSTREAM STARTING TO
SEE REDEVELOPMENT OF PRECIPITATION IN AREA THAT LOOKS TO BE DIRECTLY
AHEAD OF WEAK SHORT WAVE TROUGH AS PER WV IMAGERY AND RUC PV
ANALYSIS. TIMING THIS FEATURE PUTS IT OVER NORTHERN CWA BY
15Z...WHICH IS CONSISTENT WITH TIMING OF PRECIP AMONGST VARIOUS
MODELS AND SREF DATA AND HAVE MODIFIED FORECAST TO ACCOUNT FOR THIS
TIMING. THINK PRECIP THREAT WILL END FAIRLY QUICKLY AS THIS TROUGH
PASSES AND THINK WE WILL SEE A PERIOD OF NO PRECIPITATION ACROSS THE
CWA AROUND 21Z. FOR ACTUAL PROBABILITY VALUES...GIVEN A LARGE DEGREE
OF SPREAD IN ACTUAL PLACEMENT OF PRECIP MAXIMA AND SURPRISINGLY LOW
PROBABILITIES OF 0.05 OR GREATER FROM THE GEFS DATA AM A LITTLE
HESITANT TO GO TOO HIGH ON POPS...BUT THINK A GENERAL 30-50% CHANCE
IS WARRANTED FOR A GOOD PORTION OF THE AREA. THE ACTUAL MAGNITUDE OF
POPS WILL DEPEND STRONGLY ON BEHAVIOR OF UPSTREAM PRECIP OVER THE
NEXT FEW HOURS.
TONIGHT-SUNDAY...BRIEF PERIOD OF SUBSIDENCE WILL OVERSPREAD THE AREA
AT THE START OF THE PERIOD AS INITIAL SHORT WAVE TROUGH MOVES TO THE
EAST OF THE AREA....BEFORE NEXT TROUGH BEGINS TO DIVE INTO COLORADO
THROUGH THE OVERNIGHT HOURS. SUBSIDENCE DOES NOT LOOK ALL THAT
STRONG AT THIS POINT BUT DEFINITELY THINK LOWEST CHANCES FOR RAIN WILL
BE IN THE EARLY EVENING. MODELS HAVE HAD A BIT OF DIFFICULTY WITH
THE HANDLING OF THIS SYSTEM...JUMPING FROM VERY WET TO DRY SOLUTIONS
OVER THE PAST SEVERAL RUNS SO OVERALL CONFIDENCE IS NOT THAT HIGH.
LARGE SCALE FORCING FOR ASCENT WILL INCREASE THROUGH THE NIGHT WITH
STRONGEST VALUES BETWEEN 9Z AND 18Z SUNDAY...WITH SYNOPTIC SCALE
FORCING MAXIMIZED OVER COLORADO AND CWA REALLY ON THE FRINGE OF
STRONGEST FORCED ASCENT. APPEARS TO BE A WINDOW WITH STRONG H7 TO H5
FRONTOGENESIS DEVELOPING ACROSS THE SOUTHWESTERN CWA...BUT HAVE SOME
CONCERNS THAT A LOT OF THIS FORCING IS SOMEWHAT DUE TO CONVECTIVE
FEEDBACK ESPECIALLY ON THE GFS WHICH SEEMS TO DEVELOP SMALL LOW
CIRCULATION OVERNIGHT SATURDAY WHICH MAXIMIZES FORCING. VERY HIGH
QPF FIELDS IN SPITE OF MINIMAL INSTABILITY ALSO MAKE ME THINK THAT
THERE IS SOME FEEDBACK ISSUES AT PLAY WITH THE BULLS EYE OF ASCENT.
WITH THAT IN MIND...DO NOT WANT TO RAMP UP POPS/QPFS AT THIS TIME
DUE TO LOW CONFIDENCE IN THE PREDICTABILITY OF THESE FEATURES...BUT
FEEL 30-50% POPS WARRANTED FOR THE TIME BEING. WITH VERY LITTLE IF
ANY ELEVATED CAPE HAVE DECIDED TO KEEP WX GROUPS AS JUST RAIN.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 259 AM MDT SAT MAY 12 2012
SUNDAY NIGHT-MONDAY NIGHT...QUIETER WEATHER EXPECTED THROUGH THE
PERIOD AS MAJORITY OF OPERATIONAL DATA SUGGEST SHORT WAVE RIDGING
BUILDING OVER THE THE AREA THROUGH THE REST OF THE PERIOD BEHIND
DEPARTING TROUGH WITH SUBSIDENCE/DRYING QUICKLY BRINGING AN END TO
ANY PRECIP THREAT ACROSS THE AREA. MAIN FOCUS WILL BE HOW QUICKLY
TEMPERATURES RECOVER THROUGH THE PERIOD. GENERAL WARMING TREND LOOKS
TO BE IN ORDER...BUT GIVEN SOME MUCH COLDER DATA IN SREF PLUMES AM A
LITTLE HESITANT TO WARM THINGS TOO MUCH AT THIS POINT.
THE REGION WILL BE UNDER THE EASTERN PORTION OF AN UPPER LEVEL RIDGE
OF HIGH PRESSURE AT THE BEGINNING OF THE PERIOD...WITH DRY
CONDITIONS EXPECTED THROUGH DAYTIME WEDNESDAY. A SHORTWAVE TROUGH
WILL APPROACH THE REGION ON WEDNESDAY NIGHT AND MOVE OVER THE REGION
DURING THE DAYTIME ON THURSDAY. GIVEN THE INSTABILITY EXPECTED
DURING THIS PERIOD...HAVE INCLUDED MENTION OF THUNDERSTORMS WITH THE
SLIGHT CHANCE OF PRECIPITATION...THOUGH CONVECTIVE INHIBITION IS
STILL FAIRLY STRONG OVER MUCH OF THE AREA DURING THIS TIME. THE
UPPER LEVEL FLOW WILL BEGIN TO BECOME MORE ZONAL BY THE END OF THE
PERIOD AS THE UPPER RIDGE MOVES EASTWARD...AND ANOTHER SHORTWAVE
TROUGH BEGINS TO APPROACH THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 551 AM MDT SAT MAY 12 2012
AREA OF PRECIPITATION DEVELOPING AHEAD OF SHORT WAVE TROUGH WILL
BE PRIMARY CONCERN AT BOTH TERMINALS WITH LIGHT RAIN ALREADY
OCCURRING AT GLD AND MCK AND WILL LIKELY PERSIST THROUGH 17Z AT GLD
AND 20Z AT MCK. MAY SEE A PERIOD OF NEAR MVFR CIGS THROUGH THE
MORNING HOURS...BUT BASED OFF OF CURRENT TRENDS DO NOT THINK CIGS
WILL GET MUCH LOWER THAN 3000 FT AT THIS TIME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...LOCKHART
SHORT TERM...JRM
LONG TERM...JRM/CJS
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
605 AM MDT SAT MAY 12 2012
.UPDATE...
ISSUED AT 551 AM MDT SAT MAY 12 2012
AREA OF LIGHT RAIN SHOWERS BECOMING FAIRLY WELL ORGANIZED AHEAD OF
SHORT WAVE TROUGH ACROSS THE NORTHERN PART OF CWA...WITH
MEASURABLE PRECIPITATION BEING OBSERVED WITH WEAKER ECHOES
CONFIDENCE HAS INCREASED IN COVERAGE OF MEASURABLE PRECIP. WHILE
THINK GENERAL TIMING OF FORECAST REMAINS OK...DID INCREASE
MAGNITUDE OF POPS 20-30 PERCENT MAINLY ACROSS NORTHERN CWA TO
ACCOUNT FOR CURRENT ACTIVITY. RADAR ECHOES BECOMING BETTER
ORGANIZED TO THE SOUTH AS WELL...BUT SO FAR HAVE NOT SEEN MUCH IN
THE WAY OF -RA IN OBS SO WILL CONTINUE WITH SCATTERED POPS IN THIS
AREA.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 259 AM MDT SAT MAY 12 2012
230Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED CLOSE LOW
CIRCULATION ACROSS THE SOUTHERN PLAINS WITH LARGE TROUGH ACROSS THE
NORTHERN PLAINS WITH AN EMBEDDED SHORT WAVE TROUGH MOVING INTO
WESTERN COLORADO. AT THE SURFACE 1028MB SFC HIGH WAS BUILDING OVER
THE AREA BEHIND FRONTAL ZONE WHICH WAS DRAPED FROM SOUTHEAST
COLORADO INTO NW MISSOURI. 00Z RAOBS...ESPECIALLY AT KLBF AND KDNR
INDICATED A FAIRLY DEEP FRONT IN PLACE WITH FRONTAL INVERSION ENDING
AROUND 725 MB AND 675MB RESPECTIVELY. ALTHOUGH FAIRLY DRY AIR WAS
LOCATED BELOW INVERSION AT LBF...PARCELS LIFTED FROM TOP OF
INVERSION DID INDICATE SOME VERY WEAK CAPE PRESENT.
PRECIP CHANCES THIS MORNING THROUGH THE REST OF THE WEEKEND WILL BE
PRIMARY NEAR TERM CONCERNS.
TODAY...ONGOING LIGHT PRECIPITATION WILL BE PRIMARY FORECAST
CHALLENGE THIS MORNING AND WITH TEMPERATURES DROPPING INTO THE 30S
AND WBZ HEIGHTS FALLING TO AROUND 1500FT WOULD NOT RULE OUT A FEW
SNOW FLAKES MIXING IN WITH THE PRECIPITATION IN WESTERN CWA THIS
MORNING...BUT IF IT DOES OCCUR DO NOT THINK IT WILL AMOUNT TO MUCH
WITH SOIL TEMPS WELL ABOVE FREEZING. AREA OF LIGHT PRECIPITATION
WILL GRADUALLY SHIFT TO THE EAST THIS MORNING IN AREA OF WEAK
ISENTROPIC ASCENT AND H7 FRONTOGENESIS. INITIALLY THOUGHT THIS WOULD
BE THE ONLY AREA OF PRECIPITATION...BUT LOOKING UPSTREAM STARTING TO
SEE REDEVELOPMENT OF PRECIPITATION IN AREA THAT LOOKS TO BE DIRECTLY
AHEAD OF WEAK SHORT WAVE TROUGH AS PER WV IMAGERY AND RUC PV
ANALYSIS. TIMING THIS FEATURE PUTS IT OVER NORTHERN CWA BY
15Z...WHICH IS CONSISTENT WITH TIMING OF PRECIP AMONGST VARIOUS
MODELS AND SREF DATA AND HAVE MODIFIED FORECAST TO ACCOUNT FOR THIS
TIMING. THINK PRECIP THREAT WILL END FAIRLY QUICKLY AS THIS TROUGH
PASSES AND THINK WE WILL SEE A PERIOD OF NO PRECIPITATION ACROSS THE
CWA AROUND 21Z. FOR ACTUAL PROBABILITY VALUES...GIVEN A LARGE DEGREE
OF SPREAD IN ACTUAL PLACEMENT OF PRECIP MAXIMA AND SURPRISINGLY LOW
PROBABILITIES OF 0.05 OR GREATER FROM THE GEFS DATA AM A LITTLE
HESITANT TO GO TOO HIGH ON POPS...BUT THINK A GENERAL 30-50% CHANCE
IS WARRANTED FOR A GOOD PORTION OF THE AREA. THE ACTUAL MAGNITUDE OF
POPS WILL DEPEND STRONGLY ON BEHAVIOR OF UPSTREAM PRECIP OVER THE
NEXT FEW HOURS.
TONIGHT-SUNDAY...BRIEF PERIOD OF SUBSIDENCE WILL OVERSPREAD THE AREA
AT THE START OF THE PERIOD AS INITIAL SHORT WAVE TROUGH MOVES TO THE
EAST OF THE AREA....BEFORE NEXT TROUGH BEGINS TO DIVE INTO COLORADO
THROUGH THE OVERNIGHT HOURS. SUBSIDENCE DOES NOT LOOK ALL THAT
STRONG AT THIS POINT BUT DEFINITELY THINK LOWEST CHANCES FOR RAIN WILL
BE IN THE EARLY EVENING. MODELS HAVE HAD A BIT OF DIFFICULTY WITH
THE HANDLING OF THIS SYSTEM...JUMPING FROM VERY WET TO DRY SOLUTIONS
OVER THE PAST SEVERAL RUNS SO OVERALL CONFIDENCE IS NOT THAT HIGH.
LARGE SCALE FORCING FOR ASCENT WILL INCREASE THROUGH THE NIGHT WITH
STRONGEST VALUES BETWEEN 9Z AND 18Z SUNDAY...WITH SYNOPTIC SCALE
FORCING MAXIMIZED OVER COLORADO AND CWA REALLY ON THE FRINGE OF
STRONGEST FORCED ASCENT. APPEARS TO BE A WINDOW WITH STRONG H7 TO H5
FRONTOGENESIS DEVELOPING ACROSS THE SOUTHWESTERN CWA...BUT HAVE SOME
CONCERNS THAT A LOT OF THIS FORCING IS SOMEWHAT DUE TO CONVECTIVE
FEEDBACK ESPECIALLY ON THE GFS WHICH SEEMS TO DEVELOP SMALL LOW
CIRCULATION OVERNIGHT SATURDAY WHICH MAXIMIZES FORCING. VERY HIGH
QPF FIELDS IN SPITE OF MINIMAL INSTABILITY ALSO MAKE ME THINK THAT
THERE IS SOME FEEDBACK ISSUES AT PLAY WITH THE BULLS EYE OF ASCENT.
WITH THAT IN MIND...DO NOT WANT TO RAMP UP POPS/QPFS AT THIS TIME
DUE TO LOW CONFIDENCE IN THE PREDICTABILITY OF THESE FEATURES...BUT
FEEL 30-50% POPS WARRANTED FOR THE TIME BEING. WITH VERY LITTLE IF
ANY ELEVATED CAPE HAVE DECIDED TO KEEP WX GROUPS AS JUST RAIN.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 259 AM MDT SAT MAY 12 2012
SUNDAY NIGHT-MONDAY NIGHT...QUIETER WEATHER EXPECTED THROUGH THE
PERIOD AS MAJORITY OF OPERATIONAL DATA SUGGEST SHORT WAVE RIDGING
BUILDING OVER THE THE AREA THROUGH THE REST OF THE PERIOD BEHIND
DEPARTING TROUGH WITH SUBSIDENCE/DRYING QUICKLY BRINGING AN END TO
ANY PRECIP THREAT ACROSS THE AREA. MAIN FOCUS WILL BE HOW QUICKLY
TEMPERATURES RECOVER THROUGH THE PERIOD. GENERAL WARMING TREND LOOKS
TO BE IN ORDER...BUT GIVEN SOME MUCH COLDER DATA IN SREF PLUMES AM A
LITTLE HESITANT TO WARM THINGS TOO MUCH AT THIS POINT.
THE REGION WILL BE UNDER THE EASTERN PORTION OF AN UPPER LEVEL RIDGE
OF HIGH PRESSURE AT THE BEGINNING OF THE PERIOD...WITH DRY
CONDITIONS EXPECTED THROUGH DAYTIME WEDNESDAY. A SHORTWAVE TROUGH
WILL APPROACH THE REGION ON WEDNESDAY NIGHT AND MOVE OVER THE REGION
DURING THE DAYTIME ON THURSDAY. GIVEN THE INSTABILITY EXPECTED
DURING THIS PERIOD...HAVE INCLUDED MENTION OF THUNDERSTORMS WITH THE
SLIGHT CHANCE OF PRECIPITATION...THOUGH CONVECTIVE INHIBITION IS
STILL FAIRLY STRONG OVER MUCH OF THE AREA DURING THIS TIME. THE
UPPER LEVEL FLOW WILL BEGIN TO BECOME MORE ZONAL BY THE END OF THE
PERIOD AS THE UPPER RIDGE MOVES EASTWARD...AND ANOTHER SHORTWAVE
TROUGH BEGINS TO APPROACH THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 551 AM MDT SAT MAY 12 2012
AREA OF PRECIPITATION DEVELOPING AHEAD OF SHORT WAVE TROUGH WILL
BE PRIMARY CONCERN AT BOTH TERMINALS WITH LIGHT RAIN ALREADY
OCCURRING AT GLD AND MCK AND WILL LIKELY PERSIST THROUGH 17Z AT GLD
AND 20Z AT MCK. MAY SEE A PERIOD OF NEAR MVFR CIGS THROUGH THE
MORNING HOURS...BUT BASED OFF OF CURRENT TRENDS DO NOT THINK CIGS
WILL GET MUCH LOWER THAN 3000 FT AT THIS TIME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...JRM
LONG TERM...JRM/CJS
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
822 AM EDT SAT MAY 12 2012
.SYNOPSIS...
ISSUED AT 514 AM EDT SAT MAY 12 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
N CNTRL CANADA THROUGH MANITOBA AND NW ONTARIO INTO THE NRN PLAINS.
A PROMINENT SHORTWAVE TROUGH WAS MOVING THROUGH NRN ONTARIO TOWARD
JAMES BAY WHILE A WEAKER TRAILING SHRTWV WAS SLIDING THROUGH NRN MN.
AT THE SFC...A COLD FRONT EXTENDED FROM LOW PRES NEAR JAMES BAY
THROUGH NRN LOWER MI. -SHRA SUPPORTED BY 850-700 MB FGEN BEHIND THE
FRONT OVER CNTRL UPPER MI WERE QUICKLY DIMINISHING AND MOVING OUT OF
THE CWA. IR LOOP SHOWED CONSIDERABLE MID CLOUDS OVER THE REGION WITH
CLEARING WEST OF LAKE SUPERIOR.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 514 AM EDT SAT MAY 12 2012
TODAY...EXPECT ANY LINGERING LIGHT SHOWERS OR SPRINKLES TO EXIT THE
CWA BY DAYBREAK. SATELLITE TRENDS AND MODELS MID LEVEL RH FCST
SUGGEST THAT SKIES SHOULD CLEAR OVER THE WEST THIS MORNING AND OVER
THE SOUTHEAST EARLY THIS AFTERNOON AS THE SFC RIDGE BUILDS INTO THE
REGION. A VERY DRY AIRMASS WILL SPREAD THROUGH UPPER MI WITH PWAT
VALUES DROPPING TO NEAR 0.20 INCHES (30-35 PERCENT OF NORMAL).
PLENTY OF SUNSHINE AND STRONG MIXING DURING THE AFTERNOON PUSHING
INLAND TEMPS INTO THE MID 60S...WILL DROP RH VALUES TO AROUND 20
PERCENT. HOWEVER...NW WINDS ONLY TO AROUND 10 MPH WILL MITIGATE FIRE
WX CONCERNS.
TONIGHT...EVEN THOUGH THE HIGH AND DRIEST AIR WILL SAG TO THE
SOUTH...FAVORABLE RADIATIONAL COOLING CONDITION SHOULD ALLOW TEMPS
TO DROP TOWARD THE LOWER END OF GUIDANCE VALUES WITH INLAND READINGS
INTO THE LOWER 30S.
SUNDAY...WAA WITH INCREASING WRLY FLOW WILL PUSH TEMPS BACK ABOVE
NORMAL WITH HIGHS IN TO THE LOWER 70S AND COOLER READINGS IN THE 60S
ONLY NEAR LAKE MICHIGAN. EVEN WITH A SLIGHT INCREASE IN LOW LEVEL
MOISTURE...RH VALUES ARE EXPECTED TO FALL INTO THE 20-25 PERCENT
RANGE...LEADING TO CONTINUED ELEVATED FIRE DANGER.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 514 AM EDT SAT MAY 12 2012
THE PERIOD STARTS 00Z MON WITH AN AMPLIFIED 500MB RIDGE OVER THE WRN
CONUS...AND A TROUGH FROM A CLOSED UPPER LOW OVER HUDSON BAY TO THE
LOWER MISSISSIPPI VALLEY. LOW LEVEL FLOW WILL BE FROM THE WSW AS THE
CWA WILL BE BETWEEN A SFC LOW OVER HUDSON BAY AND SFC RIDGING FROM
THE CENTRAL PLAIN STATES TO LAKE HURON. WARM AIR WILL BE SPILLING IN
FROM THE W...WITH 850MB TEMPS AROUND 7C OVER ERN UPPER MI...AND
AROUND 11C OVER WRN LAKE SUPERIOR. A SHORTWAVE TROUGH MOVING OVER
WILL HAVE LITTLE MOISTURE TO WORK WITH...AND WILL JUST INCREASE
CLOUD COVER.
MONDAY...LOOK FOR WARM TEMPERATURES AS 850MB TEMPS INCREASE TO A CWA
AVG TEMP OF AROUND 11C. MODELS FORECAST SOUNDINGS INDICATE POTENTIAL
FOR MIXING UP TO 700MB...PRODUCING HIGH TEMPS IN THE 70S. THIS WILL
ALSO LEAD TO LOW DEW PTS...BUT WINDS WILL BE FAIRLY LIGHT WHICH WILL
HELP REDUCE FIRE WX CONCERNS.
TUESDAY LOOKS A BIT COOLER...ESPECIALLY NEAR LAKE SUPERIOR...AS
MODELS SHOW A COLD FRONT MOVING ACORSS THE AREA. 850MB TEMPS ONLY
DROP DOWN TO A CWA AVG OF 9C...BUT THE NWLY WIND WILL KEEP LOCATIONS
NEAR LAKE SUPERIOR COOLER. 12Z/11 ECMWF AND 12Z/11 GEM SHOW LIGHT
PRECIP ACCUMULATIONS OF A COUPLE TENTHS OF A INCH /AT MOST/...WHILE
THE 00Z/12 GFS KEEPS MOST OF THE AREA DRY WITH THE FRONTAL PASSAGE.
THE AIRMASS LOOKS DRY ENOUGH TO KEEP WIDESPREAD PRECIP AT BAY...BUT
SOME CONVECTION COULD BREAK OUT INLAND AS THE FRONT PASSES. NOT
CONFIDENT ENOUGH WITH PRECIP CHANCES TO GO WITH ANY POPS ABOVE LOW
CHANCE.
A SHORTWAVE TROUGH LOOKS TO DIVE OVER OR E OF THE CWA WED...BUT
MODELS VARY ON THE TRACK...AND THEREFOR THE LOCATION OF ANY
PRECIPITATION FROM THE SYSTEM. MODELS ARE IN BETTER AGREEMENT ON WED
BEING A GOOD DEAL COLDER THAN TUE...AS 850MB TEMPS ARE 5-8 DEGREES
COLDER. WITH UNCERTAINTY ON THE TRACK OF THE SHORTWAVE...WILL USE A
CONSENSUS OF GUIDANCE.
FOR THURSDAY AND FRIDAY...MODELS ARE IN GENERAL AGREEMENT IN
BRINGING THE RIDGE ORIGINALLY OVER THE WRN CONUS OVER THE CWA THU
INTO FRI. LOW LEVEL FLOW SHOULD GENERALLY BE FROM THE S...WITH SFC
TEMPS ABOVE NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 821 AM EDT SAT MAY 12 2012
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH THIS TAF
PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EDT SAT MAY 12 2012
EXPECT NORTHWEST WINDS LATE TONIGHT INTO EARLY THIS MORNING TO
REMAIN AT OR BLO 20 KTS...WITH GUSTS UP TO 25 KTS. WINDS BECOME
SOUTHWESTERLY AND DIMINISH SATURDAY AFTN AND EVENING AND SHOULD
GENERALLY STAY BLO 25 KTS INTO SUNDAY NIGHT WITH THE STRONGEST WINDS
OCCURRING OVER WESTERN LK SUPERIOR IN A SW WIND REGIME. WINDS BECOME
QUITE LIGHT...LESS THAN 15 KTS FOR MOST OF NEXT WEEK AS HIGH
PRESSURE STAYS IN THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1047 AM EDT SAT MAY 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT TO THE CAROLINA COAST TODAY WHILE A WEAK
COLD FRONT PUSHES INTO THE CENTRAL GREAT LAKES. THIS COLD FRONT WILL
GRADUALLY SAG ACROSS THE REGION LATE TONIGHT AND SUNDAY WITH AN
INCREASE IN CLOUD COVER AND A CHANCE OF A FEW LIGHT SHOWERS. THE
FRONT WILL STALL OVER OR JUST SOUTHEAST OF THE AREA SUNDAY NIGHT AND
MONDAY AND BRING MORE CLOUD COVER AND A FEW SHOWERS. THIS FRONT WILL
ONLY PUSH VERY SLOWLY EAST THROUGH THE MIDDLE OF NEXT WEEK WITH A
CHANCE OF SHOWERS LINGERING ACROSS CENTRAL NEW YORK WHILE WESTERN NY
MAY REMAIN MAINLY DRY.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE ANALYSIS LATE THIS MORNING SHOWS HIGH PRESSURE CENTERED
OVER THE PIEDMONT WITH A WEAK COLD FRONT WELL UPSTREAM ACROSS THE
WESTERN GREAT LAKES. SHOWERS ALONG THE BOUNDARY ARE FAIRLY WELL
CAPTURED BY THE HRRR AND 18Z RUNS OF THE NAM/GFS. THIS BOUNDARY
SHOULD BE VERY SLOW TO DRIFT SOUTH...WITH ALL MODEL GUIDANCE
KEEPING WESTERN NEW YORK DRY THROUGH THIS EVENING. ABOUT THE ONLY
IMPACT FROM THIS BOUNDARY WILL BE INCREASING MID AND HIGH CLOUDS
THIS AFTERNOON. OTHERWISE...THIS A QUITE WARM AIRMASS...WITH THE
12Z BUF SOUNDING SHOWING 850 MB TEMPS TO +9C. THIS SOUNDING
SUGGESTS HIGHS MAY EVEN PUSH 80 DEGREES IN INTERIOR LOCATIONS AWAY
FOR THE LAKE BREEZE...WITH HIGHS COOLER ALONG THE IMMEDIATE
LAKESHORE.
SPEAKING OF WINDS...THOSE SOUTHWEST WINDS WILL BECOME
QUITE GUSTY TODAY AS A BELT OF 25-35 KNOT WINDS AT 925MB CROSSES
THE LOWER LAKES DURING PEAK DAYTIME MIXING. THIS WILL ALLOW GUSTS
TO REACH 30-35 MPH AT THE SURFACE FROM THE NIAGARA FRONTIER
NORTHEAST TO KROC...WHICH IS THE FAVORED AREA FOR STRONGER
SOUTHWEST WINDS. THE STRONGEST WINDS WILL LIKELY BE FROM NEAR THE
BUF AIRPORT INTO THE EAST AND NORTHEAST SUBURBS AS THE FLOW
FOLLOWS ISENTROPIC SURFACES AND ESSENTIALLY DOWNSLOPES OFF THE
DOME OF COOLER/STABLE AIR OVER LAKE ERIE. THAT SAME DOME OF COOLER
MORE STABLE AIR WILL KEEP WINDS SOMEWHAT LIGHTER OVER LAKE ERIE
AND IN DOWNTOWN BUFFALO.
FOR TONIGHT...THE WINDS WILL DIMINISH QUICKLY THIS EVENING AS THE
BELT OF STRONGER 925MB WINDS WEAKENS AND DAYTIME MIXING ENDS. CLOUDS
WILL CONTINUE TO THICKEN AND INCREASE FROM NORTHWEST TO SOUTHEAST IN
ADVANCE OF THE WEAK FRONTAL BOUNDARY...WHICH WILL SAG SOUTH INTO THE
REGION AFTER 06Z SUNDAY. MODEST MID LEVEL HEIGHT FALLS AND PVA WILL
SUPPORT WEAK LARGE SCALE ASCENT...AND WEAK FRONTOGENESIS IN THE
850-700MB LAYER WILL SUPPORT SOME CONVERGENCE ALONG AND BEHIND THE
SURFACE COLD FRONT. ALL OF THIS WEAK FORCING MAY BE JUST ENOUGH TO
PRODUCE A FEW SCATTERED LIGHT SHOWERS LATE TONIGHT...MAINLY FROM THE
NIAGARA FRONTIER EAST TO ROCHESTER AND THE NORTH COUNTRY. AMOUNTS
WILL BE MINUSCULE GIVEN WEAK FORCING IN PLAY...WITH A FEW HUNDREDTHS
OF AN INCH IN SPOTTY LIGHT SHOWERS.
THE INCREASE IN CLOUD COVER AND SOME MIXING OVERNIGHT WILL KEEP LOWS
IN THE LOWER 50S ON THE LAKE PLAINS. SOME OF THE SHELTERED SOUTHERN
TIER VALLEYS WILL STILL DECOUPLE...AND CLOUDS WILL BE SLOWER TO
INCREASE THERE WHICH WILL ALLOW A FEW SPOTS TO RADIATE INTO THE MID
40S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
DURING THE COURSE OF SUNDAY...A WEAK COOL FRONT DRAPED ACROSS LAKES
ERIE AND ONTARIO AT THE START OF THE DAY WILL EVER SO SLOWLY SAG
SOUTH ACROSS THE CWA...WITH ITS SLOW PROGRESS DUE BOTH TO ITS NEAR
PARALLEL NATURE TO THE UPPER LEVEL FLOW...AND THE DEVELOPMENT OF A
WEAK WAVE OF LOW PRESSURE OVER THE TENNESSEE AND OHIO VALLEYS. THIS
FRONT WILL BE RELATIVELY STARVED FOR BOTH MOISTURE AND LIFT...SO FOR
MOST AREAS IT WILL ONLY BRING AN INCREASE IN CLOUD COVER AND A
LOW-END CHANCE FOR SOME LIGHT SHOWERS AND/OR SPRINKLES.
THE EXCEPTION TO THIS WILL COME LATER IN THE AFTERNOON ACROSS
THE SOUTHERN TIER AND INTERIOR SECTIONS OF THE FINGER LAKES...WHERE
THE FRONT WILL BEGIN TO INTERCEPT INCREASING AMOUNTS OF MOISTURE
LIFTING NORTHEAST FROM THE OHIO VALLEY...AND MAY ALSO ENCOUNTER SOME
LIMITED SURFACE-BASED INSTABILITY. THIS WILL RESULT IN A SOMEWHAT
HIGHER SHOWER POTENTIAL...AND ALSO THE POSSIBILITY OF A THUNDERSTORM
OR TWO. FOR THIS REASON...HAVE RAISED POPS TO HIGH CHANCE FOR THIS
LATTER AREA AND TIME FRAME...AND HAVE ALSO INSERTED A LOW CHANCE OF
SOME THUNDER.
BY SUNDAY EVENING...A CONSENSUS OF THE 00Z NAM/GFS/GEM/ECMWF HAS THE
SURFACE FRONTAL BOUNDARY TO BE DRAPED FROM WEST-CENTRAL PA
NORTHEASTWARD INTO CENTRAL AND EASTERN NEW YORK...WHERE IT WILL
LIKELY REMAIN IN PLACE THROUGH THE NIGHT AND MUCH OF MONDAY AS THE
AFOREMENTIONED WEAK WAVE OF LOW PRESSURE LIFTS NORTHEAST ALONG THE
BOUNDARY. INCREASING MOISTURE AND LIFT ASSOCIATED WITH THE PASSING
WAVE WILL RESULT IN AN INCREASING LIKELIHOOD OF SHOWERS ALONG THE
BOUNDARY...THOUGH THE BEST POTENTIAL FOR THESE STILL LOOKS TO LIE
JUST A LITTLE TO OUR EAST ACROSS CENTRAL AND EASTERN NY. FOR OUR
CWA...WILL INDICATE A GRADIENT IN POPS...WITH PRECIP CHANCES RANGING
FROM HIGH CHANCE ALONG OUR EASTERN PERIPHERY...TO LOW CHANCE OR EVEN
SLIGHT CHANCE ACROSS EXTREME FAR WESTERN NEW YORK AND THE SAINT
LAWRENCE VALLEY.
WITH THIS INITIAL SURFACE WAVE STILL LOOKING TO LARGELY PASS OFF TO
OUR EAST BY LATER MONDAY AFTERNOON OR EARLY MONDAY EVENING...HAVE
CONTINUED TO INDICATE A DOWNWARD TREND IN PRECIP CHANCES MONDAY
AFTERNOON...WITH JUST SOME LOW-END CHANCE POPS LINGERING ACROSS FAR
EASTERN SECTIONS BY EARLY MONDAY EVENING. AFTER THAT...HAVE PRETTY
MUCH HELD THESE PRECIP CHANCES IN PLACE RIGHT THROUGH MONDAY NIGHT
AS THE GFS/GEM/ECMWF ALL RIDGE A NARROW WEDGE OF HIGH PRESSURE
INTO FAR WESTERN NEW YORK...WHILE LIFTING A SECONDARY WAVE OF LOW
PRESSURE INTO CENTRAL AND EASTERN PA/NY.
DESPITE THE AFOREMENTIONED PRECIP CHANCES AND WHAT SHOULD BE
RELATIVELY CLOUDY CONDITIONS...TEMPS THROUGH THIS PERIOD WILL
AVERAGE CLOSE TO OR A LITTLE ABOVE AVERAGE AS A SEASONABLY MILD
AIRMASS REMAINS IN PLACE ACROSS THE LOWER GREAT LAKES. 850 MB TEMPS
WILL GENERALLY RANGE FROM +7C TO +8C WHICH WILL SUPPORTIVE OF HIGHS
IN THE UPPER 60S/LOWER 70S BOTH DAYS...WHILE NIGHTTIME LOWS FALL
INTO THE MID 40S TO LOWER 50S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ON TUESDAY...THE GFS/ECMWF ARE IN DECENT AGREEMENT THAT THE
SECONDARY LOW PRESSURE WAVE WILL PASS ACROSS CENTRAL AND EASTERN NEW
YORK...GENERALLY ALONG A PATH SIMILAR OR A LITTLE TO THE EAST OF ITS
PREDECESSOR SUNDAY NIGHT AND MONDAY. THIS SHOULD ONCE AGAIN KEEP THE
BULK OF ITS MORE WIDESPREAD SHOWER ACTIVITY TO THE EAST OF OUR
CWA...THOUGH WILL KEEP SOME LOW CHANCE POPS IN PLACE AS FAR WEST AS
THE GENESEE VALLEY TO COVER ITS PASSAGE. FURTHER TO THE WEST...FAR
WESTERN NEW YORK WILL LIKELY REMAIN DRY AS IT WILL BE SITUATED UNDER
NARROW SURFACE RIDGING BETWEEN THE AFOREMENTIONED COASTAL
SYSTEM...AND THE NEXT UPPER LEVEL TROUGH/SURFACE WAVE THAT WILL BE
IN THE PROCESS OF DIGGING INTO THE UPPER GREAT LAKES. THE SECONDARY
COASTAL WAVE WILL THEN LIFT OUT ACROSS NEW ENGLAND DURING THE COURSE
OF TUESDAY NIGHT...WITH LINGERING SHOWER CHANCES DIMINISHING ACROSS
CENTRAL AND EASTERN SECTIONS IN ITS WAKE.
THEREAFTER...THE MEDIUM RANGE GUIDANCE AGREES ON DIGGING THE
APPROACHING UPPER TROUGH/ASSOCIATED SURFACE REFLECTION ACROSS THE
LOWER LAKES REGION ON WEDNESDAY...WITH EXPANSIVE SURFACE-BASED
RIDGING THEN BUILDING ACROSS THE AREA IN ITS WAKE THURSDAY AND
FRIDAY ALONG WITH SLOWLY BUILDING HEIGHTS ALOFT. THIS WILL RESULT IN
THE CHANCE FOR SOME SCATTERED SHOWERS AND THUNDERSTORMS ON
WEDNESDAY...FOLLOWED BY A RETURN TO DRY WEATHER FOR BOTH THURSDAY
AND FRIDAY.
AS FOR TEMPERATURES...EXPECT SEASONABLE TO SLIGHTLY ABOVE AVERAGE
TEMPERATURES TO CONTINUE THROUGH TUESDAY AND WEDNESDAY WITH LITTLE
IN THE WAY OF AN AIRMASS CHANGE EXPECTED THROUGH THAT TIME. SOMEWHAT
COOLER TEMPS MAY THEN BRIEFLY RETURN FOR WEDNESDAY NIGHT AND
THURSDAY WITH THE PASSAGE OF THE UPPER TROUGH...BEFORE READINGS
RECOVER BACK TO SEASONABLE LEVELS ON FRIDAY UNDER THE BUILDING
RIDGING.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL FOR THE 15Z TAF CYCLE. HIGH PRESSURE
WILL DRIFT TO THE CAROLINA COAST TODAY AND PROVIDE CLEAR SKIES
THROUGH THE FIRST HALF OF THE DAY. MEANWHILE A WEAK COLD FRONT
OVER THE UPPER MIDWEST WILL MOVE INTO THE CENTRAL GREAT LAKES AND
BRING AN INCREASE IN MID/HIGH CLOUD FROM NORTHWEST TO SOUTHEAST
LATER THIS AFTERNOON AND EVENING.
IT WILL BECOME WINDY TODAY AS A BELT OF 30 KNOT WINDS JUST OFF THE
DECK CROSSES THE LOWER LAKES REGION...WITH MUCH OF THAT MIXING DOWN
THIS AFTERNOON WITH DAYTIME HEATING. THIS WILL BRING GUSTS IN THE
20-30 KNOT RANGE AT THE SURFACE...WITH THE STRONGEST WINDS EXPECTED
FROM KBUF-KIAG AREA OVER TO KROC. WINDS WILL QUICKLY DIMINISH THIS
EVENING AS WINDS ALOFT RELAX AND DAYTIME MIXING ENDS.
THE COLD FRONT WILL APPROACH LATE TONIGHT AND EARLY SUNDAY WITH MID
LEVEL CLOUDS THICKENING AND LOWERING. A FEW SCATTERED SHOWERS WILL
DEVELOP ALONG AND BEHIND THE SURFACE FRONT...AND A FEW OF THESE MAY
PUSH INTO KIAG-KBUF AND KART LATE TONIGHT...AND THE REMAINDER OF THE
AREA ON SUNDAY.
OUTLOOK...
SUNDAY...MAINLY VFR WITH A CHANCE OF SHOWERS. CHANCE OF A
THUNDERSTORM IN THE SOUTHERN TIER.
MONDAY...VFR/MVFR WITH A CHANCE OF SHOWERS.
TUESDAY...VFR WEST WITH VFR/MVFR EAST OF THE GENESEE VALLEY WITH A
CHANCE OF SHOWERS.
WEDNESDAY...MAINLY VFR WITH A CHANCE OF A FEW SHOWERS AND
THUNDERSTORMS.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE INTO THE 10-15 KNOT RANGE TODAY AS THE
PRESSURE GRADIENT TIGHTENS BETWEEN DEPARTING HIGH PRESSURE OVER THE
CAROLINAS AND A WEAK COLD FRONT OVER THE UPPER GREAT LAKES. WINDS
MAY BRIEFLY EXCEED 15 KNOTS ON LAKE ERIE AND WESTERN LAKE ONTARIO
DURING THE MID TO LATE MORNING...BUT THE WARMER AIRMASS MOVING INTO
THE REGION TODAY SHOULD PROMOTE THE DEVELOPMENT OF A STABLE DOME OF
LAKE COOLED AIR OVER LAKES ERIE AND ONTARIO...WHICH TYPICALLY KEEPS
WINDS LIGHTER OVER THE LAKES THIS TIME OF YEAR. WITH THIS IN MIND...
WILL KEEP CONDITIONS BELOW SMALL CRAFT ADVISORY CRITERIA WITH WINDS
PEAKING AT A LITTLE OVER 15 KNOTS AND WAVES 2-3 FEET.
WINDS WILL BE VERY LIGHT ON SUNDAY AS A WEAK COLD FRONT SLOWLY SAGS
SOUTH ACROSS THE REGION AND WEAKENS THE PRESSURE GRADIENT. LIGHT
WINDS AND FLAT WAVE ACTION WILL CONTINUE THROUGH THE FIRST HALF OF
NEXT WEEK.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL/HITCHCOCK
MARINE...APFFEL/HITCHCOCK
EQUIPMENT...HITCHCOCK
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1204 PM MDT SAT MAY 12 2012
.UPDATE...
ISSUED AT 1203 PM MDT SAT MAY 12 2012
A BATTLE BETWEEN THE DRY AIR ALOFT AND THE CONDITIONALLY UNSTABLE
AIR MASS BENEATH THE SUBSIDENT LAYER. THE SUBSIDENT LAYER IS NOT
THAT STRONG BUT NEITHER IS THE CONVECTIVE POTENTIAL. BUILDING
CUMULUS HAS FIRED OVER THE WESTERN SLOPE HIGH TERRAIN BUT NOT A
SINGLE LIGHTNING STRIKE AS OF 1745Z. DO EXPECT THUNDERSTORMS WITH
THE BEST POTENTIAL OVER THE SAN JUANS AND TOWARD THE DIVIDE. BUT
LESSER ACTIVITY FARTHER WEST AND NO STORMS EXPECTED OVER ERN UTAH
(EXCEPT FOR A POSSIBLE LATE DAY STORM OVER THE ERN UINTAS). GRIDS
HAVE BEEN UPDATED TO REFLECT THIS CURRENT THINKING.
CONSIDERATION FOR SUNDAY...CLOSED LOW CIRCULATION WILL BE MOVING
NORTH TO SOUTH. THE NAM SHOWS A TIGHTER CLOSED LOW CIRCULATION BUT
MOISTURE IS LACKING. WILL TAKE A CLOSER EXAMINATION BEFORE THE
MID AFTERNOON FORECAST UPDATE.
UPDATE ISSUED AT 754 AM MDT SAT MAY 12 2012
STRATUS SHROUDS THE UPPER GUNNISON VALLEY THIS MORNING...COVERS
BLUE MESA RESERVOIR AND THE TOWN OF GUNNISON. THESE STRATIFORM
CLOUDS WILL LIFT AND DISSIPATE LATER THIS MORNING...THE
TEMPERATURE AND DEW POINT SPREAD OF 7F AT KGUC SUGGESTS THIS WILL
BE SOONER THAN LATER.
THE HRRR SHOWS CONVECTIVE SHOWERS DEVELOPING OVER THE SAN JUAN
MOUNTAINS...BUT NOTABLY DRY OVER THE NORTHERN AND CENTRAL
MOUNTAINS THIS AFTERNOON. MUCH OF THE FORECAST AREA IS IN A DRY
AND SUBSIDENT AIR MASS THIS MORNING...BUT THIS IS ONLY TEMPORARY
AS THE NEXT UPSTREAM SHORT WAVE WILL BE APPROACHING FROM THE
NORTHWEST THIS AFTERNOON. THE FORECAST MAY BE TOO FAST WITH
SHOWERS AND STORMS REDEVELOPING OVER THE NORTHERN MOUNTAINS...WE
WILL TAKE A LOOK AT THE MODEL SUITE TO CHECK WHETHER OTHER MODELS
SHOW THIS SAME TREND.
&&
.SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 311 AM MDT SAT MAY 12
2012
NEXT UPSTREAM PACIFIC SHORTWAVE TROUGH APPARENT ON SATELLITE
IMAGERY IN SOUTHERN IDAHO. AHEAD OF THAT FEATURE...EXPECT CONVECTION
TO DEVELOP AGAIN OVER OUR CWA THIS AFTERNOON MAINLY NEAR THE
CONTINENTAL DIVIDE...THOUGH NOT AS EXTENSIVE AS ON FRIDAY. MAX
TEMPERATURES TODAY LIKELY TO BE A TAD COOLER ACROSS THE SOUTHERN
THIRD OF OUR CWA...AND SIMILAR TO YESTERDAY ACROSS THE REMAINDER
OF OUR CWA.
THE 00Z NAM HAS COME IN STRONGER WITH THE SHORTWAVE TROUGH THAT IS
PROGGED TO DROP SOUTHWARD ACROSS WY SAT NIGHT...AND THEN PROCEED
ACROSS CO/EASTERN UT ON SUNDAY. THIS SOLUTION IS IN BETTER AGREEMENT
WITH THE GFS THAN THE PREVIOUS RUN. AND BOTH MODELS NOW SEEM TO BE
JUST A LITTLE SLOWER IN MOVING THE SYSTEM SOUTHWARD INTO NM...
KEEPING IT OVER AND JUST SOUTH OF OUR SOUTHERN EDGE THROUGH SUN
EVENING.
EXPECT SCATTERED SHOWERS WILL CONTINUE THROUGH SAT NIGHT AS THIS
SHORTWAVE APPROACHES...MAINLY OVER THE EASTERN MOUNTAINS. THEN BY
SUNDAY THE TROUGH WILL MOVE OVERHEAD FOR AN UPTICK OF ACTIVITY
THROUGH THE DAY AND INTO THE EVENING. WHILE THE EASTERN MOUNTAINS
WILL CONTINUE TO BE FAVORED...WILL EXPAND COVERAGE WESTWARD SOMEWHAT
AS THE NAM SHOWS THE 500 MB LOW DROPPING ALONG THE UT/CO BORDER
THROUGH THE DAY. AN EASTERLY OR DOWNSLOPE COMPONENT QUICKLY FOLLOWS
WITH DIMINISHING ACTIVITY FROM THE NORTH BEGINNING BEFORE SUNSET AS
THE TROUGH AXIS MOVES INTO NM. SHOWERS WILL LINGER LONGEST OVER THE
SOUTHERN DIVIDE.
HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND WEST LATE SUN NIGHT
INTO MONDAY. BY MONDAY AFTERNOON THE HIGH PRESSURE RIDGE WILL BE
JUST UPSTREAM...CENTERED OVER UT WITH DRIER AND WARMER CONDITIONS
FOR OUR CWA.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 311 AM MDT SAT MAY
12 2012
MIGRATORY UPPER RIDGE SHOULD BE MOVING ACROSS OUR CWA MONDAY NIGHT
AND TUESDAY WITH RELATIVELY DRY CONDITIONS EXCEPT FOR ISOLATED
CONVECTION OVER THE MOUNTAINS. THEN A PACIFIC SHORTWAVE
DISTURBANCE IS STILL EXPECTED TO DRIFT ACROSS OUR AREA ON
WEDNESDAY...FOLLOWED BY ANOTHER DISTURBANCE ON THURSDAY... WHICH
SHOULD RESULT IN A FEW SHOWERS AND THUNDERSTORMS MAINLY OVER THE
MOUNTAINS. THESE FEATURES SHOULD HAVE MINIMAL IMPACT ON
TEMPERATURES...EXCEPT FOR THE INFLUENCE OF ANY CLOUD COVER.
AN INCREASING SW FLOW ALOFT IS STILL EXPECTED OVER OUR CWA ON
FRIDAY AS THE MODELS ARE INDICATING A MORE SIGNIFICANT SHORTWAVE
TROUGH APPROACHING OUR CWA. PRESENTLY...NEXT FRIDAY APPEARS TO BE
A RATHER DRY DAY FOR OUR CWA WITH BREEZY SOUTHERLY SURFACE WINDS.
MAX TEMPERATURES DURING THIS PERIOD SHOULD BE NEARLY 10 DEGREES
ABOVE NORMAL AT MOST LOCATIONS...WITH MIN TEMPERATURES 5 TO 10
DEGREES ABOVE NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1203 PM MDT SAT MAY 12 2012
THE MAIN AVIATION HAZARD WILL BE CONVECTIVE STORMS AND GUSTY
OUTFLOW WINDS. SHOWERS WITH EMBEDDED THUNDERSTORMS WILL HUG THE
HIGHER TERRAIN...BUT A PASSING SHORT LIVED STORM WILL BE IN THE
VICINITY OF KEGE AND KASE. KRIL...KMTJ...AND KGJT COULD EXPERIENCE
GUSTY OUTFLOW WINDS FROM DISTANT STORMS. NO THUNDERSTORMS ARE
EXPECTED OVER ERN UTAH EXCEPT FOR A LATE DAY STORM OVER THE ERN
UINTA MOUNTAINS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...EH
LONG TERM...JRP
AVIATION...PF
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
359 PM EDT SAT MAY 12 2012
.SHORT TERM /TONIGHT THROUGH MONDAY/...
MAIN FORECAST CONCERN WILL BE QPF AND POPS ASSOCIATED WITH
DEVELOPING LOW PRESSURE SYSTEM APPROACHING THE FORECAST AREA FROM
THE WEST. MODELS ARE GENERALLY IN GOOD AGREEMENT WITH THIS FEATURE
HOWEVER THE GFS SEEMS TO HAVE A SLIGHTLY BETTER HANDLE ON IT AND
THE ASSOCIATED PRECIPITATION...THEREFORE MADE MINOR TWEAKES TO MAV
INITIALIZATION. HRRR IS SUGGESTING SOME SCATTERED SHOWER
DEVELOPMENT AHEAD OF THE MAIN SWATH AFTER 21Z THIS EVENING...
WHILE THE MORE WIDESPREAD RAIN SHOULD AFFECT THE WESTERN PORTIONS
AFTER ABOUT 03Z. HAVE THEREFORE KEPT CHANCE POPS THIS AFTERNOON
AND INCREASED TO LIKELY AND CATEGORICAL POPS ACROSS THE
NORTHWESTERN HALF OF THE AREA OVERNIGHT. SOME BREAKS IN THE CLOUD
DECK THIS AFTERNOON HAS ALLOWED CAPE VALUES TO INCREASE SOMEWHAT
SO THERE IS STILL A SLIGHT CHANCE FOR THUNDERSTORMS.
SUNDAY LOOKS TO BE THE WETTEST DAY IN THE SHORT TERM WITH THE
HEAVIEST RAINFALL LIKELY OCCURRING IN THE NORTHERN PORTIONS OF THE
AREA DURING THE MORNING AND SUNDAY OVERNIGHT. LATEST 12Z GFS AND NAM
TIME HEIGHTS ALSO SHOW DEEPEST HIGH RH LAYER INFLUENCING THE AREA ON
SUNDAY WITH LESS MOISTURE ON MONDAY THAN PREVIOUSLY THOUGHT. HAVE
THEREFORE MAINTAINED CATEGORICAL POPS IN THE NORTH... LIKELY POPS
CENTRAL... AND HIGH END CHANCE POPS SOUTH THROUGH SUNDAY. MODELS DO
INDICATED A BIT HIGHER CAPE VALUES AFTER 18Z SUNDAY SO HAVE INCLUDED
CHANCE OF THUNDERSTORMS. THE UPPER LEVEL SHORTWAVE TROUGH AXIS
SHOULD SWING THROUGH THE AREA BY AROUND 18Z MONDAY AND THE WEAK COLD
FRONT ASSOCIATED WITH THE PHASED SURFACE LOW SHOULD PASS AROUND 00Z
TUESDAY...THUS ALLOWING FOR CHANCE POPS TO CONTINUE THROUGH MUCH OF
THE DAY. LESS QPF IS EXPECTED DURING THIS TIME HOWEVER.
FOR TOTAL QPF...HPC GUIDANCE IS OVERALL LEANING MORE TOWARD GFS
AMOUNTS GIVING 48 HOUR RAINFALL TOTALS OF NEAR 2.5 INCHES IN THE NORTH
TO HALF AN INCH IN THE SOUTHEAST BY 00Z TUESDAY. THE HEAVIEST OF
WHICH SHOULD OCCUR SUNDAY MORNING AND SUNDAY OVERNIGHT.
FOR TEMPS...MAV GUIDANCE SEEMS TO HAVE BEEN DOING WELL WITH PROGGED
HIGHS AND LOWS SO MADE ONLY MINOR TWEAKS. MONDAY LOOKS TO BE A BIT
WARMER THAN TUESDAY WITH HIGHS IN THE MID TO UPPER 70S NORTH AND LOW
TO MID 80S SOUTH.
03
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MODELS CONTINUE TO HOLD A BROAD TROUGH ACROSS THE SOUTHEAST THROUGH
THE PERIOD. LOW PRESSURE DEVELOPING IN THE CENTRAL GULF SHOULD BE
INTO THE WESTERN CAROLINAS AT THE BEGINNING OF THE PERIOD...WITH
MOST OF THE RAINFALL EAST OF THE CWA. HAVE HELD ON TO LOW POPS
ACROSS THE EASTERN ZONES INTO WEDNESDAY NIGHT. SOME QUESTION AS TO
HOW MUCH MOISTURE LINGERS BEHIND THIS SYSTEM AS MODELS HOLD THE
BROAD UPPER TROUGH ACROSS THE SOUTHEAST AND REMNANTS OF THE
SURFACE FRONT DRIFT ACROSS CENTRAL OR SOUTH GEORGIA. HAVE NOT
ADDED ANY POPS TO THE LAST FEW DAYS DUE TO LOW CONFIDENCE IN THE
MODEL SOLUTION.
41
&&
HYDROLOGY...
/ISSUED 330 PM EDT SAT MAY 12 2012/
HPC 1-3 DAY QPF TOTAL ENDING 12Z TUESDAY SHOWS 2.5 TO 3.00 ACROSS
EXTREME NORTH GEORGIA AND LESSER AMOUNTS ELSEWHERE. 6 HOUR FFG
VALUES ARE AROUND 4.5 INCHES OVER THE NORTH. WITH EXPECTED
RAINFALL SPREAD OVER A COUPLE OF DAYS...THINK WE SHOULD BE ABLE
TO HANDLE THESE FORECAST AMOUNTS...BUT WILL HAVE TO WATCH FOR
LOCALIZED PROBLEMS ON THE CREEKS AND RIVERS ACROSS THE NORTH.
41
AVIATION...
18Z UPDATE...
CIGS HAVE BEEN BOUNCING BETWEEN VFR AND MVFR THIS AFTERNOON...
HOWEVER SITES SHOULD STAY AT VFR LEVELS FOR THE MOST PART. WINDS
SHOULD REMAIN SOUTHEASTERLY THROUGH THE FORECAST PERIOD AND MOST
SITES SHOULD HAVE GUSTS THIS AFTERNOON STAYING UNDER 20KTS. AFTER
21Z THIS EVENING LOCATIONS EXCEPT FOR KMCN A BIT LATER SHOULD
BEGIN TO HAVE -SHRA WITH CONTINUED CHANCES THROUGH THE PERIOD.
CIGS LOOK TO LOWER TO MVFR LEVELS WITH 0VC020 BY 03Z AND IFR WITH
0VC007 ALONG WITH VISBYS AROUND 4SM BY 10Z SUNDAY. INTRODUCED
-TSRA FOR KATL AFTER 18Z SUNDAY.
//ATL CONFIDENCE...18Z UPDATE...
HIGH.
03
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 59 73 62 79 / 50 70 60 50
ATLANTA 62 73 63 77 / 70 80 50 40
BLAIRSVILLE 57 65 59 74 / 60 80 80 50
CARTERSVILLE 63 71 63 77 / 80 80 70 40
COLUMBUS 65 79 65 81 / 70 60 50 40
GAINESVILLE 59 70 62 77 / 60 80 80 50
MACON 61 79 63 82 / 50 50 50 50
ROME 63 75 62 80 / 80 80 60 40
PEACHTREE CITY 60 75 60 78 / 70 80 50 40
VIDALIA 66 81 67 84 / 30 50 50 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....41
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
135 PM EDT SAT MAY 12 2012
.SYNOPSIS...
ISSUED AT 514 AM EDT SAT MAY 12 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
N CNTRL CANADA THROUGH MANITOBA AND NW ONTARIO INTO THE NRN PLAINS.
A PROMINENT SHORTWAVE TROUGH WAS MOVING THROUGH NRN ONTARIO TOWARD
JAMES BAY WHILE A WEAKER TRAILING SHRTWV WAS SLIDING THROUGH NRN MN.
AT THE SFC...A COLD FRONT EXTENDED FROM LOW PRES NEAR JAMES BAY
THROUGH NRN LOWER MI. -SHRA SUPPORTED BY 850-700 MB FGEN BEHIND THE
FRONT OVER CNTRL UPPER MI WERE QUICKLY DIMINISHING AND MOVING OUT OF
THE CWA. IR LOOP SHOWED CONSIDERABLE MID CLOUDS OVER THE REGION WITH
CLEARING WEST OF LAKE SUPERIOR.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 514 AM EDT SAT MAY 12 2012
TODAY...EXPECT ANY LINGERING LIGHT SHOWERS OR SPRINKLES TO EXIT THE
CWA BY DAYBREAK. SATELLITE TRENDS AND MODELS MID LEVEL RH FCST
SUGGEST THAT SKIES SHOULD CLEAR OVER THE WEST THIS MORNING AND OVER
THE SOUTHEAST EARLY THIS AFTERNOON AS THE SFC RIDGE BUILDS INTO THE
REGION. A VERY DRY AIRMASS WILL SPREAD THROUGH UPPER MI WITH PWAT
VALUES DROPPING TO NEAR 0.20 INCHES (30-35 PERCENT OF NORMAL).
PLENTY OF SUNSHINE AND STRONG MIXING DURING THE AFTERNOON PUSHING
INLAND TEMPS INTO THE MID 60S...WILL DROP RH VALUES TO AROUND 20
PERCENT. HOWEVER...NW WINDS ONLY TO AROUND 10 MPH WILL MITIGATE FIRE
WX CONCERNS.
TONIGHT...EVEN THOUGH THE HIGH AND DRIEST AIR WILL SAG TO THE
SOUTH...FAVORABLE RADIATIONAL COOLING CONDITION SHOULD ALLOW TEMPS
TO DROP TOWARD THE LOWER END OF GUIDANCE VALUES WITH INLAND READINGS
INTO THE LOWER 30S.
SUNDAY...WAA WITH INCREASING WRLY FLOW WILL PUSH TEMPS BACK ABOVE
NORMAL WITH HIGHS IN TO THE LOWER 70S AND COOLER READINGS IN THE 60S
ONLY NEAR LAKE MICHIGAN. EVEN WITH A SLIGHT INCREASE IN LOW LEVEL
MOISTURE...RH VALUES ARE EXPECTED TO FALL INTO THE 20-25 PERCENT
RANGE...LEADING TO CONTINUED ELEVATED FIRE DANGER.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 514 AM EDT SAT MAY 12 2012
THE PERIOD STARTS 00Z MON WITH AN AMPLIFIED 500MB RIDGE OVER THE WRN
CONUS...AND A TROUGH FROM A CLOSED UPPER LOW OVER HUDSON BAY TO THE
LOWER MISSISSIPPI VALLEY. LOW LEVEL FLOW WILL BE FROM THE WSW AS THE
CWA WILL BE BETWEEN A SFC LOW OVER HUDSON BAY AND SFC RIDGING FROM
THE CENTRAL PLAIN STATES TO LAKE HURON. WARM AIR WILL BE SPILLING IN
FROM THE W...WITH 850MB TEMPS AROUND 7C OVER ERN UPPER MI...AND
AROUND 11C OVER WRN LAKE SUPERIOR. A SHORTWAVE TROUGH MOVING OVER
WILL HAVE LITTLE MOISTURE TO WORK WITH...AND WILL JUST INCREASE
CLOUD COVER.
MONDAY...LOOK FOR WARM TEMPERATURES AS 850MB TEMPS INCREASE TO A CWA
AVG TEMP OF AROUND 11C. MODELS FORECAST SOUNDINGS INDICATE POTENTIAL
FOR MIXING UP TO 700MB...PRODUCING HIGH TEMPS IN THE 70S. THIS WILL
ALSO LEAD TO LOW DEW PTS...BUT WINDS WILL BE FAIRLY LIGHT WHICH WILL
HELP REDUCE FIRE WX CONCERNS.
TUESDAY LOOKS A BIT COOLER...ESPECIALLY NEAR LAKE SUPERIOR...AS
MODELS SHOW A COLD FRONT MOVING ACROSS THE AREA. 850MB TEMPS ONLY
DROP DOWN TO A CWA AVG OF 9C...BUT THE NWLY WIND WILL KEEP LOCATIONS
NEAR LAKE SUPERIOR COOLER. 12Z/11 ECMWF AND 12Z/11 GEM SHOW LIGHT
PRECIP ACCUMULATIONS OF A COUPLE TENTHS OF A INCH /AT MOST/...WHILE
THE 00Z/12 GFS KEEPS MOST OF THE AREA DRY WITH THE FRONTAL PASSAGE.
THE AIRMASS LOOKS DRY ENOUGH TO KEEP WIDESPREAD PRECIP AT BAY...BUT
SOME CONVECTION COULD BREAK OUT INLAND AS THE FRONT PASSES. NOT
CONFIDENT ENOUGH WITH PRECIP CHANCES TO GO WITH ANY POPS ABOVE LOW
CHANCE.
A SHORTWAVE TROUGH LOOKS TO DIVE OVER OR E OF THE CWA WED...BUT
MODELS VARY ON THE TRACK...AND THEREFOR THE LOCATION OF ANY
PRECIPITATION FROM THE SYSTEM. MODELS ARE IN BETTER AGREEMENT ON WED
BEING A GOOD DEAL COLDER THAN TUE...AS 850MB TEMPS ARE 5-8 DEGREES
COLDER. WITH UNCERTAINTY ON THE TRACK OF THE SHORTWAVE...WILL USE A
CONSENSUS OF GUIDANCE.
FOR THURSDAY AND FRIDAY...MODELS ARE IN GENERAL AGREEMENT IN
BRINGING THE RIDGE ORIGINALLY OVER THE WRN CONUS OVER THE CWA THU
INTO FRI. LOW LEVEL FLOW SHOULD GENERALLY BE FROM THE S...WITH SFC
TEMPS ABOVE NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 130 PM EDT SAT MAY 12 2012
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH THIS TAF
PERIOD. CONFIDENCE IS NOT HIGH ON WHEN...HOW LONG...OR EVEN IF IWD
AND CMX WILL DECOUPLE ENOUGH TO BRING WINDS LESS THAN 12KTS...SO
TRENDED TOWARD DECREASING WINDS IN THE EVENING BEFORE PRESSURE
GRADIENT INCREASES IN THE EARLY MORNING HOURS AND SHALLOW STABLE
LAYER POTENTIALLY MIXES OUT IN THE HIGHER TERRAIN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EDT SAT MAY 12 2012
EXPECT NORTHWEST WINDS LATE TONIGHT INTO EARLY THIS MORNING TO
REMAIN AT OR BLO 20 KTS...WITH GUSTS UP TO 25 KTS. WINDS BECOME
SOUTHWESTERLY AND DIMINISH SATURDAY AFTN AND EVENING AND SHOULD
GENERALLY STAY BLO 25 KTS INTO SUNDAY NIGHT WITH THE STRONGEST WINDS
OCCURRING OVER WESTERN LK SUPERIOR IN A SW WIND REGIME. WINDS BECOME
QUITE LIGHT...LESS THAN 15 KTS FOR MOST OF NEXT WEEK AS HIGH
PRESSURE STAYS IN THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...TK
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
242 PM EDT SAT MAY 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT TO THE CAROLINA COAST TODAY WHILE A WEAK
COLD FRONT PUSHES INTO THE CENTRAL GREAT LAKES. THIS COLD FRONT WILL
GRADUALLY SAG ACROSS THE REGION LATE TONIGHT AND SUNDAY WITH AN
INCREASE IN CLOUD COVER AND A CHANCE OF A FEW LIGHT SHOWERS. THE
FRONT WILL STALL OVER OR JUST SOUTHEAST OF THE AREA SUNDAY NIGHT AND
MONDAY AND BRING MORE CLOUD COVER AND A FEW SHOWERS. THIS FRONT WILL
ONLY PUSH VERY SLOWLY EAST THROUGH THE MIDDLE OF NEXT WEEK WITH A
CHANCE OF SHOWERS LINGERING ACROSS CENTRAL NEW YORK WHILE WESTERN NY
MAY REMAIN MAINLY DRY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS HIGH PRESSURE
CENTERED OVER THE PIEDMONT WITH A WEAK COLD FRONT WELL UPSTREAM
ACROSS LAKE HURON. SHOWERS ALONG THE BOUNDARY ARE FAIRLY WELL
CAPTURED BY THE HRRR AND 12Z RUNS OF THE NAM/GFS/RGEM. THIS
BOUNDARY WILL BE VERY SLOW TO DRIFT SOUTH...WITH SHOWERS EXPECTED
TO BE VERY SLOW TO APPROACH WESTERN NEW YORK FOR THE REMAINDER OF
TODAY. ABOUT THE ONLY IMPACT FROM THIS BOUNDARY WILL BE
INCREASING MID AND HIGH CLOUDS THIS AFTERNOON. OTHERWISE...THIS A
QUITE WARM AIR MASS...WITH THE 12Z BUF SOUNDING SHOWING 850 MB
TEMPS TO +9C. EXPECT INTERIOR SECTIONS TO RISE INTO THE UPPER
70S...WITH PORTIONS OF THE FINGER LAKES LIKELY TO REACH 80 TODAY.
THE LAKE BREEZE WILL KEEP THE IMMEDIATE LAKESHORES COOLER...WITH
BUFFALO METRO LIKELY TO TOP OUT IN THE UPPER 60S TO LOWER 70S
DEPENDING ON PROXIMITY TO THE LAKESHORE.
SPEAKING OF WINDS...THOSE SOUTHWEST WINDS WILL CONTINUE TO BE
GUSTY THROUGH THIS AFTERNOON AS A BELT OF 25-35 KNOT WINDS AT
925 MB CROSSES THE LOWER LAKES DURING PEAK DAYTIME MIXING. THIS
WILL ALLOW GUSTS TO REACH 30-35 MPH AT THE SURFACE FROM THE
NIAGARA FRONTIER NORTHEAST TO KROC...WHICH IS THE FAVORED AREA FOR
STRONGER SOUTHWEST WINDS. THE STRONGEST WINDS WILL LIKELY BE FROM
NEAR THE BUF AIRPORT INTO THE EAST AND NORTHEAST SUBURBS AS THE
FLOW FOLLOWS ISENTROPIC SURFACES AND ESSENTIALLY DOWNSLOPES OFF
THE DOME OF COOLER/STABLE AIR OVER LAKE ERIE. THAT SAME DOME OF
COOLER MORE STABLE AIR WILL KEEP WINDS SOMEWHAT LIGHTER OVER LAKE
ERIE AND IN DOWNTOWN BUFFALO.
FOR TONIGHT...THE WINDS WILL DIMINISH QUICKLY THIS EVENING AS THE
BELT OF STRONGER 925MB WINDS WEAKENS AND DAYTIME MIXING ENDS. CLOUDS
WILL CONTINUE TO THICKEN AND INCREASE FROM NORTHWEST TO SOUTHEAST IN
ADVANCE OF THE WEAK FRONTAL BOUNDARY...WHICH WILL SAG SOUTH INTO THE
REGION AFTER 06Z SUNDAY. MODEST MID LEVEL HEIGHT FALLS AND PVA WILL
SUPPORT WEAK LARGE SCALE ASCENT...AND WEAK FRONTOGENESIS IN THE
850-700MB LAYER WILL SUPPORT SOME CONVERGENCE ALONG AND BEHIND THE
SURFACE COLD FRONT. ALL OF THIS WEAK FORCING MAY BE JUST ENOUGH TO
PRODUCE A FEW SCATTERED LIGHT SHOWERS LATE TONIGHT...MAINLY FROM THE
NIAGARA FRONTIER EAST TO ROCHESTER AND THE NORTH COUNTRY. AMOUNTS
WILL BE MINUSCULE GIVEN WEAK FORCING IN PLAY...WITH A FEW HUNDREDTHS
OF AN INCH IN SPOTTY LIGHT SHOWERS.
THE INCREASE IN CLOUD COVER AND SOME MIXING OVERNIGHT WILL KEEP LOWS
IN THE LOWER 50S ON THE LAKE PLAINS. SOME OF THE SHELTERED SOUTHERN
TIER VALLEYS WILL STILL DECOUPLE...AND CLOUDS WILL BE SLOWER TO
INCREASE THERE WHICH WILL ALLOW A FEW SPOTS TO RADIATE INTO THE MID
40S.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
DURING THE COURSE OF SUNDAY...A WEAK COOL FRONT DRAPED ACROSS LAKES
ERIE AND ONTARIO AT THE START OF THE DAY WILL EVER SO SLOWLY SAG
SOUTH ACROSS THE CWA...WITH ITS SLOW PROGRESS DUE BOTH TO ITS NEAR
PARALLEL NATURE TO THE UPPER LEVEL FLOW...AND THE DEVELOPMENT OF A
WEAK WAVE OF LOW PRESSURE OVER THE TENNESSEE AND OHIO VALLEYS. THIS
FRONT WILL BE RELATIVELY STARVED FOR BOTH MOISTURE AND LIFT...SO FOR
MOST AREAS IT WILL ONLY BRING AN INCREASE IN CLOUD COVER AND A
LOW-END CHANCE FOR SOME LIGHT SHOWERS AND/OR SPRINKLES.
THE EXCEPTION TO THIS WILL COME LATER IN THE AFTERNOON ACROSS
THE SOUTHERN TIER AND INTERIOR SECTIONS OF THE FINGER LAKES...WHERE
THE FRONT WILL BEGIN TO INTERCEPT INCREASING AMOUNTS OF MOISTURE
LIFTING NORTHEAST FROM THE OHIO VALLEY...AND MAY ALSO ENCOUNTER SOME
LIMITED SURFACE-BASED INSTABILITY. THIS WILL RESULT IN A SOMEWHAT
HIGHER SHOWER POTENTIAL...AND ALSO THE POSSIBILITY OF A THUNDERSTORM
OR TWO. FOR THIS REASON...HAVE RAISED POPS TO HIGH CHANCE FOR THIS
LATTER AREA AND TIME FRAME...AND HAVE ALSO INSERTED A LOW CHANCE OF
SOME THUNDER.
BY SUNDAY EVENING...A CONSENSUS OF THE 00Z NAM/GFS/GEM/ECMWF HAS THE
SURFACE FRONTAL BOUNDARY TO BE DRAPED FROM WEST-CENTRAL PA
NORTHEASTWARD INTO CENTRAL AND EASTERN NEW YORK...WHERE IT WILL
LIKELY REMAIN IN PLACE THROUGH THE NIGHT AND MUCH OF MONDAY AS THE
AFOREMENTIONED WEAK WAVE OF LOW PRESSURE LIFTS NORTHEAST ALONG THE
BOUNDARY. INCREASING MOISTURE AND LIFT ASSOCIATED WITH THE PASSING
WAVE WILL RESULT IN AN INCREASING LIKELIHOOD OF SHOWERS ALONG THE
BOUNDARY...THOUGH THE BEST POTENTIAL FOR THESE STILL LOOKS TO LIE
JUST A LITTLE TO OUR EAST ACROSS CENTRAL AND EASTERN NY. FOR OUR
CWA...WILL INDICATE A GRADIENT IN POPS...WITH PRECIP CHANCES RANGING
FROM HIGH CHANCE ALONG OUR EASTERN PERIPHERY...TO LOW CHANCE OR EVEN
SLIGHT CHANCE ACROSS EXTREME FAR WESTERN NEW YORK AND THE SAINT
LAWRENCE VALLEY.
WITH THIS INITIAL SURFACE WAVE STILL LOOKING TO LARGELY PASS OFF TO
OUR EAST BY LATER MONDAY AFTERNOON OR EARLY MONDAY EVENING...HAVE
CONTINUED TO INDICATE A DOWNWARD TREND IN PRECIP CHANCES MONDAY
AFTERNOON...WITH JUST SOME LOW-END CHANCE POPS LINGERING ACROSS FAR
EASTERN SECTIONS BY EARLY MONDAY EVENING. AFTER THAT...HAVE PRETTY
MUCH HELD THESE PRECIP CHANCES IN PLACE RIGHT THROUGH MONDAY NIGHT
AS THE GFS/GEM/ECMWF ALL RIDGE A NARROW WEDGE OF HIGH PRESSURE
INTO FAR WESTERN NEW YORK...WHILE LIFTING A SECONDARY WAVE OF LOW
PRESSURE INTO CENTRAL AND EASTERN PA/NY.
DESPITE THE AFOREMENTIONED PRECIP CHANCES AND WHAT SHOULD BE
RELATIVELY CLOUDY CONDITIONS...TEMPS THROUGH THIS PERIOD WILL
AVERAGE CLOSE TO OR A LITTLE ABOVE AVERAGE AS A SEASONABLY MILD
AIR MASS REMAINS IN PLACE ACROSS THE LOWER GREAT LAKES. 850 MB TEMPS
WILL GENERALLY RANGE FROM +7C TO +8C WHICH WILL SUPPORTIVE OF HIGHS
IN THE UPPER 60S/LOWER 70S BOTH DAYS...WHILE NIGHTTIME LOWS FALL
INTO THE MID 40S TO LOWER 50S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ON TUESDAY...THE GFS/ECMWF ARE IN DECENT AGREEMENT THAT THE
SECONDARY LOW PRESSURE WAVE WILL PASS ACROSS CENTRAL AND EASTERN NEW
YORK...GENERALLY ALONG A PATH SIMILAR OR A LITTLE TO THE EAST OF ITS
PREDECESSOR SUNDAY NIGHT AND MONDAY. THIS SHOULD ONCE AGAIN KEEP THE
BULK OF ITS MORE WIDESPREAD SHOWER ACTIVITY TO THE EAST OF OUR
CWA...THOUGH WILL KEEP SOME LOW CHANCE POPS IN PLACE AS FAR WEST AS
THE GENESEE VALLEY TO COVER ITS PASSAGE. FURTHER TO THE WEST...FAR
WESTERN NEW YORK WILL LIKELY REMAIN DRY AS IT WILL BE SITUATED UNDER
NARROW SURFACE RIDGING BETWEEN THE AFOREMENTIONED COASTAL
SYSTEM...AND THE NEXT UPPER LEVEL TROUGH/SURFACE WAVE THAT WILL BE
IN THE PROCESS OF DIGGING INTO THE UPPER GREAT LAKES. THE SECONDARY
COASTAL WAVE WILL THEN LIFT OUT ACROSS NEW ENGLAND DURING THE COURSE
OF TUESDAY NIGHT...WITH LINGERING SHOWER CHANCES DIMINISHING ACROSS
CENTRAL AND EASTERN SECTIONS IN ITS WAKE.
THEREAFTER...THE MEDIUM RANGE GUIDANCE AGREES ON DIGGING THE
APPROACHING UPPER TROUGH/ASSOCIATED SURFACE REFLECTION ACROSS THE
LOWER LAKES REGION ON WEDNESDAY...WITH EXPANSIVE SURFACE-BASED
RIDGING THEN BUILDING ACROSS THE AREA IN ITS WAKE THURSDAY AND
FRIDAY ALONG WITH SLOWLY BUILDING HEIGHTS ALOFT. THIS WILL RESULT IN
THE CHANCE FOR SOME SCATTERED SHOWERS AND THUNDERSTORMS ON
WEDNESDAY...FOLLOWED BY A RETURN TO DRY WEATHER FOR BOTH THURSDAY
AND FRIDAY.
AS FOR TEMPERATURES...EXPECT SEASONABLE TO SLIGHTLY ABOVE AVERAGE
TEMPERATURES TO CONTINUE THROUGH TUESDAY AND WEDNESDAY WITH LITTLE
IN THE WAY OF AN AIR MASS CHANGE EXPECTED THROUGH THAT TIME. SOMEWHAT
COOLER TEMPS MAY THEN BRIEFLY RETURN FOR WEDNESDAY NIGHT AND
THURSDAY WITH THE PASSAGE OF THE UPPER TROUGH...BEFORE READINGS
RECOVER BACK TO SEASONABLE LEVELS ON FRIDAY UNDER THE BUILDING
RIDGING.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
WINDS WILL BE GUSTY THROUGH THE REMAINDER OF THE AFTERNOON...
ESPECIALLY AT BUF/IAG/ROC. OTHERWISE...ANY CLOUDS WILL BE
HIGH...WITH VFR CONDITIONS HIGHLY LIKELY.
A WEAK COLD FRONT WILL SLOWLY APPROACH FROM THE NORTHWEST TONIGHT. AT
NIGHT...THIS BOUNDARY SHOULD NOT BE VERY ACTIVE...WITH SHOWERS
EXPECTED TO BE SCATTERED IN NATURE. TIMING IS ALSO PROBLEMATIC
GIVEN THE SLOW MOTION OF THE FRONT. BECAUSE THE FRONT IS
WEAK...IT WILL HAVE MINIMAL IMPACT ON OPERATIONS...WITH ONLY LIGHT
WINDS WITH THE BOUNDARY. ALSO...MARGINAL LOW LEVEL MOISTURE SUGGESTS THERE
WILL LIKELY BE VFR CONDITIONS WITH THE FRONT...THOUGH MVFR CANNOT
COMPLETELY RULED OUT.
EXPECT SHOWERS TO LINGER ON SUNDAY...PERHAPS ENHANCING A BIT
DURING THE AFTERNOON DUE TO DAYTIME HEATING. THE BEST CHANCE FOR
SHOWERS IS AT JHW...CLOSEST TO THE BOUNDARY.
OUTLOOK...
SUNDAY NIGHT AND MONDAY...VFR/MVFR WITH A CHANCE OF SHOWERS.
TUESDAY AND WEDNESDAY...MAINLY VFR WITH A CHANE OF A FEW SHOWERS.
THURSDAY...VFR.
&&
.MARINE...
WINDS WILL VARY DUE TO LAKE INFLUENCES...WITH THE RELATIVELY COOLER
WATERS ON THE LAKES ACTING AS A STABILIZING INFLUENCE. THE RESULT
WILL BE GENERALLY CALMER WINDS CLOSER TO THE CENTER OF THE
LAKES...WITH STRONGER WINDS ON THE IMMEDIATE SHORELINE. SOUTHWEST
WINDS IN THE 10 TO 20 KNOT RANGE ON LAKE ERIE SHOULD QUICKLY
DIMINISH THIS EVENING. BECAUSE OF LESSER WINDS FURTHER
OFFSHORE...EXPECT WAVES TO REMAIN IN THE 2 TO 3 FOOT RANGE...BELOW
SMALL CRAFT CRITERIA.
OTHERWISE...A WEAK COLD FRONT WILL DROP ACROSS THE WATERS
TONIGHT...FOLLOWED BY WEAK HIGH PRESSURE EARLY NEXT WEEK. THIS
SHOULD RESULT IN A RELATIVELY LIGHT WINDS ON THE WATERS WHICH SHOULD
LAST WELL INTO NEXT WEEK. WIND DIRECTION WILL VARY DUE TO LAKE BREEZE
INFLUENCES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
142 PM EDT SAT MAY 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT TO THE CAROLINA COAST TODAY WHILE A WEAK
COLD FRONT PUSHES INTO THE CENTRAL GREAT LAKES. THIS COLD FRONT WILL
GRADUALLY SAG ACROSS THE REGION LATE TONIGHT AND SUNDAY WITH AN
INCREASE IN CLOUD COVER AND A CHANCE OF A FEW LIGHT SHOWERS. THE
FRONT WILL STALL OVER OR JUST SOUTHEAST OF THE AREA SUNDAY NIGHT AND
MONDAY AND BRING MORE CLOUD COVER AND A FEW SHOWERS. THIS FRONT WILL
ONLY PUSH VERY SLOWLY EAST THROUGH THE MIDDLE OF NEXT WEEK WITH A
CHANCE OF SHOWERS LINGERING ACROSS CENTRAL NEW YORK WHILE WESTERN NY
MAY REMAIN MAINLY DRY.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS HIGH PRESSURE
CENTERED OVER THE PIEDMONT WITH A WEAK COLD FRONT WELL UPSTREAM
ACROSS LAKE HURON. SHOWERS ALONG THE BOUNDARY ARE FAIRLY WELL
CAPTURED BY THE HRRR AND 12Z RUNS OF THE NAM/GFS/RGEM. THIS
BOUNDARY WILL BE VERY SLOW TO DRIFT SOUTH...WITH SHOWERS EXPECTED
TO BE VERY SLOW TO APPROACH WESTERN NEW YORK FOR THE REMAINDER OF
TODAY. ABOUT THE ONLY IMPACT FROM THIS BOUNDARY WILL BE
INCREASING MID AND HIGH CLOUDS THIS AFTERNOON. OTHERWISE...THIS A
QUITE WARM AIR MASS...WITH THE 12Z BUF SOUNDING SHOWING 850 MB
TEMPS TO +9C. EXPECT INTERIOR SECTIONS TO RISE INTO THE UPPER
70S...WITH PORTIONS OF THE FINGER LAKES LIKELY TO REACH 80 TODAY.
THE LAKE BREEZE WILL KEEP THE IMMEDIATE LAKESHORES COOLER...WITH
BUFFALO METRO LIKELY TO TOP OUT IN THE UPPER 60S TO LOWER 70S
DEPENDING ON PROXIMITY TO THE LAKESHORE.
SPEAKING OF WINDS...THOSE SOUTHWEST WINDS WILL CONTINUE TO BE
GUSTY THROUGH THIS AFTERNOON AS A BELT OF 25-35 KNOT WINDS AT
925 MB CROSSES THE LOWER LAKES DURING PEAK DAYTIME MIXING. THIS
WILL ALLOW GUSTS TO REACH 30-35 MPH AT THE SURFACE FROM THE
NIAGARA FRONTIER NORTHEAST TO KROC...WHICH IS THE FAVORED AREA FOR
STRONGER SOUTHWEST WINDS. THE STRONGEST WINDS WILL LIKELY BE FROM
NEAR THE BUF AIRPORT INTO THE EAST AND NORTHEAST SUBURBS AS THE
FLOW FOLLOWS ISENTROPIC SURFACES AND ESSENTIALLY DOWNSLOPES OFF
THE DOME OF COOLER/STABLE AIR OVER LAKE ERIE. THAT SAME DOME OF
COOLER MORE STABLE AIR WILL KEEP WINDS SOMEWHAT LIGHTER OVER LAKE
ERIE AND IN DOWNTOWN BUFFALO.
FOR TONIGHT...THE WINDS WILL DIMINISH QUICKLY THIS EVENING AS THE
BELT OF STRONGER 925MB WINDS WEAKENS AND DAYTIME MIXING ENDS. CLOUDS
WILL CONTINUE TO THICKEN AND INCREASE FROM NORTHWEST TO SOUTHEAST IN
ADVANCE OF THE WEAK FRONTAL BOUNDARY...WHICH WILL SAG SOUTH INTO THE
REGION AFTER 06Z SUNDAY. MODEST MID LEVEL HEIGHT FALLS AND PVA WILL
SUPPORT WEAK LARGE SCALE ASCENT...AND WEAK FRONTOGENESIS IN THE
850-700MB LAYER WILL SUPPORT SOME CONVERGENCE ALONG AND BEHIND THE
SURFACE COLD FRONT. ALL OF THIS WEAK FORCING MAY BE JUST ENOUGH TO
PRODUCE A FEW SCATTERED LIGHT SHOWERS LATE TONIGHT...MAINLY FROM THE
NIAGARA FRONTIER EAST TO ROCHESTER AND THE NORTH COUNTRY. AMOUNTS
WILL BE MINUSCULE GIVEN WEAK FORCING IN PLAY...WITH A FEW HUNDREDTHS
OF AN INCH IN SPOTTY LIGHT SHOWERS.
THE INCREASE IN CLOUD COVER AND SOME MIXING OVERNIGHT WILL KEEP LOWS
IN THE LOWER 50S ON THE LAKE PLAINS. SOME OF THE SHELTERED SOUTHERN
TIER VALLEYS WILL STILL DECOUPLE...AND CLOUDS WILL BE SLOWER TO
INCREASE THERE WHICH WILL ALLOW A FEW SPOTS TO RADIATE INTO THE MID
40S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
DURING THE COURSE OF SUNDAY...A WEAK COOL FRONT DRAPED ACROSS LAKES
ERIE AND ONTARIO AT THE START OF THE DAY WILL EVER SO SLOWLY SAG
SOUTH ACROSS THE CWA...WITH ITS SLOW PROGRESS DUE BOTH TO ITS NEAR
PARALLEL NATURE TO THE UPPER LEVEL FLOW...AND THE DEVELOPMENT OF A
WEAK WAVE OF LOW PRESSURE OVER THE TENNESSEE AND OHIO VALLEYS. THIS
FRONT WILL BE RELATIVELY STARVED FOR BOTH MOISTURE AND LIFT...SO FOR
MOST AREAS IT WILL ONLY BRING AN INCREASE IN CLOUD COVER AND A
LOW-END CHANCE FOR SOME LIGHT SHOWERS AND/OR SPRINKLES.
THE EXCEPTION TO THIS WILL COME LATER IN THE AFTERNOON ACROSS
THE SOUTHERN TIER AND INTERIOR SECTIONS OF THE FINGER LAKES...WHERE
THE FRONT WILL BEGIN TO INTERCEPT INCREASING AMOUNTS OF MOISTURE
LIFTING NORTHEAST FROM THE OHIO VALLEY...AND MAY ALSO ENCOUNTER SOME
LIMITED SURFACE-BASED INSTABILITY. THIS WILL RESULT IN A SOMEWHAT
HIGHER SHOWER POTENTIAL...AND ALSO THE POSSIBILITY OF A THUNDERSTORM
OR TWO. FOR THIS REASON...HAVE RAISED POPS TO HIGH CHANCE FOR THIS
LATTER AREA AND TIME FRAME...AND HAVE ALSO INSERTED A LOW CHANCE OF
SOME THUNDER.
BY SUNDAY EVENING...A CONSENSUS OF THE 00Z NAM/GFS/GEM/ECMWF HAS THE
SURFACE FRONTAL BOUNDARY TO BE DRAPED FROM WEST-CENTRAL PA
NORTHEASTWARD INTO CENTRAL AND EASTERN NEW YORK...WHERE IT WILL
LIKELY REMAIN IN PLACE THROUGH THE NIGHT AND MUCH OF MONDAY AS THE
AFOREMENTIONED WEAK WAVE OF LOW PRESSURE LIFTS NORTHEAST ALONG THE
BOUNDARY. INCREASING MOISTURE AND LIFT ASSOCIATED WITH THE PASSING
WAVE WILL RESULT IN AN INCREASING LIKELIHOOD OF SHOWERS ALONG THE
BOUNDARY...THOUGH THE BEST POTENTIAL FOR THESE STILL LOOKS TO LIE
JUST A LITTLE TO OUR EAST ACROSS CENTRAL AND EASTERN NY. FOR OUR
CWA...WILL INDICATE A GRADIENT IN POPS...WITH PRECIP CHANCES RANGING
FROM HIGH CHANCE ALONG OUR EASTERN PERIPHERY...TO LOW CHANCE OR EVEN
SLIGHT CHANCE ACROSS EXTREME FAR WESTERN NEW YORK AND THE SAINT
LAWRENCE VALLEY.
WITH THIS INITIAL SURFACE WAVE STILL LOOKING TO LARGELY PASS OFF TO
OUR EAST BY LATER MONDAY AFTERNOON OR EARLY MONDAY EVENING...HAVE
CONTINUED TO INDICATE A DOWNWARD TREND IN PRECIP CHANCES MONDAY
AFTERNOON...WITH JUST SOME LOW-END CHANCE POPS LINGERING ACROSS FAR
EASTERN SECTIONS BY EARLY MONDAY EVENING. AFTER THAT...HAVE PRETTY
MUCH HELD THESE PRECIP CHANCES IN PLACE RIGHT THROUGH MONDAY NIGHT
AS THE GFS/GEM/ECMWF ALL RIDGE A NARROW WEDGE OF HIGH PRESSURE
INTO FAR WESTERN NEW YORK...WHILE LIFTING A SECONDARY WAVE OF LOW
PRESSURE INTO CENTRAL AND EASTERN PA/NY.
DESPITE THE AFOREMENTIONED PRECIP CHANCES AND WHAT SHOULD BE
RELATIVELY CLOUDY CONDITIONS...TEMPS THROUGH THIS PERIOD WILL
AVERAGE CLOSE TO OR A LITTLE ABOVE AVERAGE AS A SEASONABLY MILD
AIR MASS REMAINS IN PLACE ACROSS THE LOWER GREAT LAKES. 850 MB TEMPS
WILL GENERALLY RANGE FROM +7C TO +8C WHICH WILL SUPPORTIVE OF HIGHS
IN THE UPPER 60S/LOWER 70S BOTH DAYS...WHILE NIGHTTIME LOWS FALL
INTO THE MID 40S TO LOWER 50S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ON TUESDAY...THE GFS/ECMWF ARE IN DECENT AGREEMENT THAT THE
SECONDARY LOW PRESSURE WAVE WILL PASS ACROSS CENTRAL AND EASTERN NEW
YORK...GENERALLY ALONG A PATH SIMILAR OR A LITTLE TO THE EAST OF ITS
PREDECESSOR SUNDAY NIGHT AND MONDAY. THIS SHOULD ONCE AGAIN KEEP THE
BULK OF ITS MORE WIDESPREAD SHOWER ACTIVITY TO THE EAST OF OUR
CWA...THOUGH WILL KEEP SOME LOW CHANCE POPS IN PLACE AS FAR WEST AS
THE GENESEE VALLEY TO COVER ITS PASSAGE. FURTHER TO THE WEST...FAR
WESTERN NEW YORK WILL LIKELY REMAIN DRY AS IT WILL BE SITUATED UNDER
NARROW SURFACE RIDGING BETWEEN THE AFOREMENTIONED COASTAL
SYSTEM...AND THE NEXT UPPER LEVEL TROUGH/SURFACE WAVE THAT WILL BE
IN THE PROCESS OF DIGGING INTO THE UPPER GREAT LAKES. THE SECONDARY
COASTAL WAVE WILL THEN LIFT OUT ACROSS NEW ENGLAND DURING THE COURSE
OF TUESDAY NIGHT...WITH LINGERING SHOWER CHANCES DIMINISHING ACROSS
CENTRAL AND EASTERN SECTIONS IN ITS WAKE.
THEREAFTER...THE MEDIUM RANGE GUIDANCE AGREES ON DIGGING THE
APPROACHING UPPER TROUGH/ASSOCIATED SURFACE REFLECTION ACROSS THE
LOWER LAKES REGION ON WEDNESDAY...WITH EXPANSIVE SURFACE-BASED
RIDGING THEN BUILDING ACROSS THE AREA IN ITS WAKE THURSDAY AND
FRIDAY ALONG WITH SLOWLY BUILDING HEIGHTS ALOFT. THIS WILL RESULT IN
THE CHANCE FOR SOME SCATTERED SHOWERS AND THUNDERSTORMS ON
WEDNESDAY...FOLLOWED BY A RETURN TO DRY WEATHER FOR BOTH THURSDAY
AND FRIDAY.
AS FOR TEMPERATURES...EXPECT SEASONABLE TO SLIGHTLY ABOVE AVERAGE
TEMPERATURES TO CONTINUE THROUGH TUESDAY AND WEDNESDAY WITH LITTLE
IN THE WAY OF AN AIR MASS CHANGE EXPECTED THROUGH THAT TIME. SOMEWHAT
COOLER TEMPS MAY THEN BRIEFLY RETURN FOR WEDNESDAY NIGHT AND
THURSDAY WITH THE PASSAGE OF THE UPPER TROUGH...BEFORE READINGS
RECOVER BACK TO SEASONABLE LEVELS ON FRIDAY UNDER THE BUILDING
RIDGING.
&&
.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
WINDS WILL BE GUSTY THROUGH THE REMAINDER OF THIS AFTERNOON...ESPECIALLY
AT BUF AND IAG. OTHERWISE...ANY CLOUDS WILL BE HIGH...WITH VFR
CONDITIONS HIGHLY LIKELY.
A WEAK COLD FRONT WILL SLOWLY APPROACH FROM THE NORTH TONIGHT. AT
NIGHT...THIS BOUNDARY SHOULD NOT BE VERY ACTIVE...WITH SHOWERS
EXPECTED TO BE SCATTERED IN NATURE. TIMING IS ALSO PROBLEMATIC
GIVEN THE SLOW MOTION OF THE FRONT. BECAUSE THE FRONT IS
WEAK...IT WILL HAVE MINIMAL IMPACT ON OPERATIONS...WITH ONLY
LIGHT POST-FRONTAL WINDS. ALSO...MARGINAL LOW LEVEL MOISTURE
SUGGESTS THERE WILL LIKELY BE VFR CONDITIONS WITH THE
FRONT...THOUGH MVFR CANNOT COMPLETELY RULED OUT.
EXPECT SHOWERS TO LINGER ON SUNDAY...PERHAPS ENHANCING A BIT
DURING THE AFTERNOON DUE TO DAYTIME HEATING. THE BEST CHANCE FOR
SHOWERS IS AT JHW...CLOSEST TO THE BOUNDARY.
OUTLOOK...
SUNDAY NIGHT AND MONDAY...VFR/MVFR WITH A CHANCE OF SHOWERS.
TUESDAY...VFR WEST WITH VFR/MVFR EAST OF THE GENESEE VALLEY WITH A
CHANCE OF SHOWERS.
WEDNESDAY...MAINLY VFR WITH A CHANCE OF A FEW SHOWERS AND
THUNDERSTORMS.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE INTO THE 10-15 KNOT RANGE TODAY AS THE
PRESSURE GRADIENT TIGHTENS BETWEEN DEPARTING HIGH PRESSURE OVER THE
CAROLINAS AND A WEAK COLD FRONT OVER THE UPPER GREAT LAKES. WINDS
MAY BRIEFLY EXCEED 15 KNOTS ON LAKE ERIE AND WESTERN LAKE ONTARIO
DURING THE MID TO LATE MORNING...BUT THE WARMER AIR MASS MOVING
INTO THE REGION TODAY SHOULD PROMOTE THE DEVELOPMENT OF A STABLE
DOME OF LAKE COOLED AIR OVER LAKES ERIE AND ONTARIO...WHICH
TYPICALLY KEEPS WINDS LIGHTER OVER THE LAKES THIS TIME OF YEAR.
WITH THIS IN MIND... WILL KEEP CONDITIONS BELOW SMALL CRAFT
ADVISORY CRITERIA WITH WINDS PEAKING AT A LITTLE OVER 15 KNOTS AND
WAVES 2-3 FEET.
WINDS WILL BE VERY LIGHT ON SUNDAY AS A WEAK COLD FRONT SLOWLY SAGS
SOUTH ACROSS THE REGION AND WEAKENS THE PRESSURE GRADIENT. LIGHT
WINDS AND FLAT WAVE ACTION WILL CONTINUE THROUGH THE FIRST HALF OF
NEXT WEEK.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/HITCHCOCK