Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/22/15
AREA FORECAST DISCUSSION
NWS RENO NV
1020 AM PDT MON APR 20 2015
.AVIATION UPDATE...
FOR THE 18Z TAFS WE`VE ADDED BRIEF TEMPO GROUPS FOR TSTMS AT TVL/TRK
THIS AFTERNOON. LATEST GUIDANCE INCLUDING HRRR SUGGESTS ENOUGH OF A
RISK OF TSTMS TO ADD TEMPO FOR MVFR CONDITIONS AND GUSTY WINDS,
ABOUT A 60% CHANCE. HAVE ALSO ADDED SIMILAR TEMPO PERIODS AT RNO/CXP
FOR GUSTY OUTFLOW WINDS FROM TSTMS OVER THE SIERRA. WITH
SUFFICIENTLY DRY BOUNDARY LAYER ANY TSTMS SHOULD PRODUCE LARGE
OUTFLOWS AND LATEST HRRR RUNS ARE SHOWING THAT WIND MAKING IT INTO
THE RNO/CXP AREAS LATE THIS AFTERNOON. ADMITTEDLY CONFIDENCE IS ONLY
40% IN THAT HAPPENING BUT ENOUGH OF A RISK TO ADD IN THE TAF. CS
&&
.SYNOPSIS...
SCATTERED AFTERNOON SHOWERS AND ISOLATED THUNDERSTORMS WILL
DEVELOP IN THE SIERRA TODAY. LOW PRESSURE WILL MOVE INTO EASTERN
CALIFORNIA AND WESTERN NEVADA TUESDAY AND LAST THROUGH MUCH OF THE
WORK WEEK, BRINGING INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS
OUT INTO WESTERN NEVADA AS WELL AS COOLER TEMPERATURES AREA WIDE.
&&
.SHORT TERM...
CONVECTIVE DEVELOPMENT THIS AFTERNOON AND EVENING LOOKS FAIRLY
SIMILAR TO SUNDAY, WITH THE BULK OF THE SHOWERS AND ISOLATED
THUNDERSTORMS DEVELOPING NEAR THE CREST AND MOVING TO THE WEST
SLOPES OF THE SIERRA IN THE STEERING FLOW ALOFT. A DRY SUB-CLOUD
LAYER COULD PROMOTE GUSTY OUTFLOW WINDS TO AROUND 40 MPH WITH ANY
THUNDERSTORMS. LATE IN THE AFTERNOON YESTERDAY, A LARGE-SCALE
OUTFLOW FROM CONVECTION NEAR THE CREST WAS NOTED IN THE VISIBLE
SATELLITE NEAR THE CALIFORNIA-NEVADA BORDER IN EASTERN MONO
COUNTY. WEB CAMS LOOKING EAST FROM LEE VINING INDICATED IT MAINLY
PRODUCED SOME VIRGA OR A FEW STRAY RAINDROPS. THIS COULD CERTAINLY
OCCUR AGAIN TODAY OUT INTO EXTREME WESTERN NEVADA BUT MEASURABLE
PRECIPITATION IS NOT EXPECTED.
TUESDAY, LOW PRESSURE CURRENTLY OFF THE SOUTHERN CALIFORNIA COAST
WILL MOVE INLAND WHILE THE UPPER RIDGE NEAR THE OREGON COAST TODAY
SHIFTS TO NEAR THE IDAHO BORDER. THIS WILL CAUSE THE UPPER FLOW TO
TURN AROUND TO A MORE SOUTHERLY DIRECTION OVER NORTHEAST CALIFORNIA
AND WESTERN NEVADA. THE SOUTHERLY STEERING FLOW AND SOME LOWER
LEVEL WEST WIND CONVERGENCE IN THE IMMEDIATE LEE OF THE SIERRA
SHOULD ALLOW SHOWERS AND THUNDERSTORMS TO FORM ON THE SIERRA AND
MOVE NORTH AND EAST INTO WESTERN NEVADA DURING THE LATE AFTERNOON
AND EVENING ON TUESDAY. THUNDERSTORMS DO NOT LOOK OVERLY STRONG
BASED ON MODEL INSTABILITY AND SHEAR. HOWEVER, AS WITH MONDAY, ANY
THUNDERSTORMS COULD DROP WIND GUSTS TO 40 MPH OR SO ALONG WITH
BRIEF LIGHT TO MODERATE RAINFALL.
WEDNESDAY, LOTS OF DEBRIS CLOUDS FROM TUESDAY`S CONVECTION MAY
COMBINE WITH UPPER DIVERGENCE/LIFT TO THE NORTH OF THE UPPER LOW
(OVER SOUTHEAST CALIFORNIA) TO BRING WIDESPREAD CLOUD COVER. THIS
WILL TEND TO REDUCE INSTABILITY WITH COOLER AFTERNOON TEMPERATURES
AND CAUSE THE CHANCE FOR THUNDERSTORMS TO WANE. STILL, SCATTERED
SHOWERS ARE EXPECTED FOR WEDNESDAY AFTERNOON WITH INCREASING
MOISTURE AND SOME MODEST UPPER FORCING. SNYDER
.LONG TERM...THURSDAY THROUGH SUNDAY...
FEW CHANGES MADE WITH SHOWERS LOOKING TO CONTINUE INTO THURSDAY WITH
A COUPLE THUNDERSTORMS POSSIBLE AS THE UPPER LOW EJECTS INTO ARIZONA.
A DRIER WEST TO NORTHWEST FLOW FRIDAY WILL PUSH MUCH OF THE MOISTURE
EASTWARD AS A STRONGER LOW MOVES INTO WASHINGTON. A FEW SHOWERS
REMAIN POSSIBLE, BUT WITH THE DRYING AND SOME WARMING ALOFT IT LOOKS
MUCH LESS LIKELY THAN AT THIS TIME YESTERDAY.
A MORE ZONAL FLOW IS EXPECTED FOR NEXT WEEKEND, ALTHOUGH THE SIERRA
AND WESTERN NEVADA SHOULD BE UNDER A SHORT WAVE RIDGE. THIS WILL BE
AHEAD OF A DEEPENING TROUGH NEAR 135W. THEREFORE, DO NOT EXPECT MUCH
IF ANYTHING IN THE WAY OF PRECIPITATION AS THE WEAK ATMOSPHERIC
RIVER IS POINTED INTO WASHINGTON. REGARDING TEMPERATURES, IT WILL
WARM SLIGHTLY BUT OVERALL WILL REMAIN CLOSE TO AVERAGE VALUES FOR
LATE APRIL. WALLMANN
&&
.AVIATION...
A FEW THUNDERSTORMS EXPECTED AGAIN THIS AFTERNOON ALONG THE SIERRA
CREST FROM MAMMOTH MTN TO LASSEN PEAK FROM 20-03Z. LOCAL MVR CONDS
POSSIBLE WITH GUSTY OUTFLOW WINDS. THESE STORMS HAVE ABOUT A 20-30
PCT CHANCE OF IMPACTING KMMH-KTVK-KTRK. ELSEWHERE, VFR CONDITIONS
EXPECTED WITH LIGHT WINDS. MORE STORMS ARE POSSIBLE AROUND THE SAME
TIME TUESDAY AFTERNOON WITH KRNO/KCXP POSSIBLY AFFECTED. WALLMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS PUEBLO CO
318 PM MDT MON APR 20 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 318 PM MDT MON APR 20 2015
CURRENTLY...
MODEST NW FLOW PREVAILS ALOFT ACROSS THE REGION. ISOLD TO SCTD SHRA
AND -TSRA WERE NOTED OVER THE HIGHER TRRN AND WERE MOVING ONTO THE
PLAINS. MOST UNSTABLE ATMOSPHERE WAS NOTED OVER THE SPANISH PEAKS
REGION PER RADAR AND TOTAL LTG DATA. TEMPS WERE COOL AT 3 PM WITH
TEMPS IN THE U50S/L60S PLAINS AND 50S VALLEYS.
REST OF TODAY AND THIS EVENING....
ISOLD PRECIP ACTIVITY WILL CONTINUE OVER THE HIGHER TRRN WITH SOME
OF THIS ACTIVITY MOVING ONTO THE PLAINS. ANY ACTIVITY OVER THE PLAINS
WILL GENERALLY REMAIN ISOLD...WITH A BIT MORE COVERAGE EXPECTED
ALONG THE CO/NM BORDER. ACTIVITY WILL REMAIN WEAK WITH BIGGEST
CONCERN BEING CG ACTIVITY.
TONIGHT...
ANY PRECIP OVER THE REGION WILL DIE BY LATER THIS EVENING IF NOT
EARLIER. HRRR AND NAM GUIDANCE DO SHOW A TSTORM OR TWO OVER THE
PLAINS EARLY THIS EVENING UNDER THE MODEST NW FLOW. TEMPS WILL COO
INTO THE 30-35F RANGE ACROSS THE PLAINS WITH 20S IN THE VALLEYS.
TUESDAY...
IT WILL BE WARMER TOMORROW WITH HIGHS EXPECTED TO REACH INTO THE
LOWER 70S MOST OF THE PLAINS...AND 60S VALLEYS. I DO EXPECT THAT WE
WILL SEE A PRECIP PATTERN SIMILAR TO TODAY IN THAT SHOWERS AND
STORMS WILL FORM OVER THE MTNS AND MOVE ONTO THE PLAINS. ACTIVITY
WILL BE A LITTLE MORE ROBUST TOMORROW AS WE SHOULD SEE A BIT MORE
INSTABILITY TOMORROW...HOWEVER NO STRONG ACTIVITY IS ANTICIPATED AT
THIS TIME. /HODANISH
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 318 PM MDT MON APR 20 2015
RELATIVELY ACTIVE LONGER TERM IS ANTICIPATED WITH PRIMARY
METEOROLOGICAL ISSUES BEING POPS(INCLUDING THUNDERSTORMS
AND MOUNTAIN SNOWS)...TEMPERATURES AND GUSTY WINDS AT TIMES.
RECENT LONGER TERM COMPUTER SIMULATIONS...FORECAST MODEL
SOUNDINGS...PV ANALYSIS AND ADDITIONAL METEOROLOGICAL PARAMETERS
SUGGEST THAT TRANSITORY UPPER RIDGING TO SOUTHWESTERLY UPPER
FLOW WILL BE IN PLACE OVER THE FORECAST DISTRICT FROM TUESDAY
NIGHT INTO THURSDAY IN ADVANCE OF NEXT UPPER DISTURBANCE
IMPACTING CWFA FROM LATER THURSDAY INTO FRIDAY NIGHT WITH
ANOTHER UPPER DISTURBANCE IMPACTING THE FORECAST DISTRICT
FROM SATURDAY INTO SATURDAY NIGHT.
AT LOWER LEVELS...SURFACE HIGH CENTERED OVER SOUTH DAKOTA AT 06Z
WEDNESDAY SLOWLY SHIFTS INTO THE UPPER MIDWEST BY FRIDAY
NIGHT...WHILE SURFACE LOW DEVELOPS OVER SOUTHEASTERN COLORADO BY
06Z FRIDAY BEFORE SHIFTING INTO OKLAHOMA BY 06Z SATURDAY AS
NORTHERLY SURFACE SURGE PUSHES ACROSS EASTERN SECTIONS FRIDAY
NIGHT.
THE COMBINATION OF THESE METEOROLOGICAL PARAMETERS IN
COMBINATION WITH ADEQUATE ATMOSPHERIC MOISTURE WILL ALLOW FOR
UNSETTLED CONDITIONS AT TIMES OVER THE CWFA DURING THE
MAJORITY OF THE LONGER TERM IN COMBINATION WITH TEMPERATURES
RUNNING WITHIN A CATEGORY OR SO OF MID TO LATE APRIL
CLIMATOLOGICAL AVERAGES MOST LOCATIONS...ALTHOUGH SOME
ADDITIONAL WARMING IS PROJECTED TO DEVELOP BY EARLY NEXT WEEK.
AT THIS TIME...IT APPEARS THAT THE HIGHEST POTENTIAL OF STRONGER
CONVECTIVE POTENTIAL DURING THE LONGER TERM MAY BE REALIZED
WEDNESDAY AND THURSDAY(ESPECIALLY EASTERN SECTIONS) AS DEEPER
ATMOSPHERIC MOISTURE INTERACTS WITH UPPER IMPULSES TO PRODUCE
LOCALIZED POTENTIAL CAPES/LIS AND BULK SHEARS VALUES OF -5C/1000+
J/KG AND 40 KNOTS RESPECTIVELY BOTH DAYS. AS ALWAYS...WFO PUEBLO
WILL MONITOR CLOSELY.
IN ADDITION...HIGHER ELEVATION ACCUMULATING SNOW IS ANTICIPATED
AT TIMES WITH GUSTY GRADIENT WINDS ALSO POSSIBLE...PRIMARILY FROM
FRIDAY INTO FRIDAY NIGHT. FINALLY...AS BRIEFLY TOUCHED UPON
EARLIER...WARMEST CONDITIONS DURING THE LONGER TERM SHOULD BE
NOTED BY NEXT MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 318 PM MDT MON APR 20 2015
VFR CONDITIONS ARE ANTICIPATED DURING THE NEXT 24H AT ALL 3 TAF
SITES...KPUB...KALS AND KCOS. VERY ISOLD TSRA WILL BE POSSIBLE THIS
EVENING AND TOMORROW EVENING AT KCOS AND KPUB. WINDS WILL BE
DIURNALLY DRIVEN AND WILL BE LIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1115 PM MDT SUN APR 19 2015
.UPDATE...
ISSUED AT 902 PM MDT SUN APR 19 2015
NARROW BANDS OF SHOWERS CONTINUE TO STREAK OFF THE SOUTHEAST MTS AND
INTO THE ADJACENT INTERSTATE 25 CORRIDOR. THESE HAVE BEEN PRETTY
LOCALIZED SO FAR. NEXT WAVE WILL COME IN AFTER MIDNIGHT ASSOC WITH
DISTURBANCE BACK ACROSS UT/WRN CO. 00Z NAM12 LOOKS CONVECTIVELY
CONTAMINATED...AND WENT WITH A BLEND OF THE LATEST
RAP13...HRRR...AND 18Z GFS. STILL SOME DISCREPANCIES BETWEEN EVEN
THESE MODELS...WITH RAP13 AND HRRR PREFERRING A MORE SOUTHERN
TRACK...ACROSS THE SOUTHWEST MOUNTAINS...SANGRES AND WETS AND
SOUTHERN I-25 CORRIDOR. WHILE GFS...AND THE HEAVY HANDED NAM12
TAKE GREATEST QPF TOTALS ACROSS NORTHERN AND CENTRAL CO...ACROSS
THE PIKES PEAK REGION LATE TONIGHT. HAVE TRENDED TOWARDS THE MORE
SOUTHERN TRACK...AND WILL SEE WHAT 00Z GFS RUN GIVES BEFORE MAKING
DRASTIC CHANGES. OVERALL FORECAST TRENDS POPS UPWARDS INTO THE SCT
CATEGORY LATE TONIGHT...WITH POPS TRENDING DOWNWARD FROM WEST TO
EAST MONDAY MORNING. -KT
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 243 PM MDT SUN APR 19 2015
CURRENTLY...THE UPPER TROUGH HAS MOVED WELL EAST INTO EASTERN KS
THIS AFTN...AND STRONG N-NW WINDS ON THE BACKSIDE OF THE SYSTEM HAVE
BEGUN TO MELLOW AS A RESULT. BRISK WINDS WITH GUSTS UP TO 30 MPH
CONTINUE FROM APPROX LHX AND EASTWARD. UNDER INTERMITTENT CLOUD
COVER WITH ABUNDANT CLOUD BREAKS...TEMPS HAVE WARMED INTO THE 40S TO
LOWER 50S FOR MOST LOWER ELEVATIONS LOCATIONS.
TONIGHT AND TOMORROW...NW FLOW ALOFT HAS SETTLED IN AND WILL BE THE
MAIN STORY OVER THE NEXT FEW DAYS. ONE UPPER WAVE IS NEARING THE
STATE...AND IS EXPECTED TO SPARK ISOLATED TO SCATTERED SHOWERS AND
STORMS OVER THE MTS AND NEARBY PLAINS LATE THIS AFTN AND EVE. AS THE
NIGHT PROGRESSES...MODELS INDICATE THAT THIS WAVE WILL CONTINUE
EAST...PROMOTING MORE CONVECTION OVER THE PALMER DVD AND RAMPART
RANGE AFTER MIDNIGHT. THIS WAS A BIT DIFFERENT THAN WHAT WAS IN THE
FORECAST GRIDS...SO INCREASED POPS IN THOSE LOCATIONS. TOMORROW AFTN
SHOWERS AND STORMS ARE FORECAST TO REDEVELOP OVER THE HIGHER TERRAIN
FOLLOWING A MORE DIURNAL CONVECTIVE PATTERN. THE CHALLENGE TONIGHT
WILL BE MIN TEMPS. TEMPS ARE HOVERING NEAR THE FREEZING MARK...AND
WHETHER THEY STAY JUST ABOVE OR DIP BELOW THAT MARK WILL BE
DETERMINED BY CLOUD COVER. THE WINDS ARE ALREADY STARTING TO DIE
DOWN...SO SIGNIFICANT BREAKS IN THE CLOUD COVER WILL ALLOW MORE
EFFICIENT RADIATIONAL COOLING. HAVE OPTED TO NOT ISSUE ANY SORT OF
FREEZE HIGHLIGHT AT THIS TIME SINCE THE OFFICIAL START IS MAY
1...BUT SOME ATTENTION TO OUTDOOR PLANTS MAY BE IN ORDER FOR
TONIGHT. AS FOR TOMORROW...AFTN MAX TEMPS SHOULD BE ON PAR OR A FEW
DEGREES WARMER THAN THOSE RECORDED TODAY. MOORE
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 243 PM MDT SUN APR 19 2015
...BUSY WEATHER PATTERN DURING THIS PERIOD...
WEATHER WILL LIKELY BE A BIT ACTIVE DURING THE EXTENDED PERIOD AS A
FEW DISTURBANCES WILL KEEP AREAS OF PRECIP AND THUNDER OVER THE
REGION. ON FRIDAY...WE MAY SEE SOME ORGANIZED ROTATING CONVECTION
ON THE PLAINS.
MONDAY EVENING A DISTURBANCE WILL BE MOVING ACROSS THE REGION ND
THIS SHOULD ALLOW FOR SOME SCATTERED SHOWERS AND STORMS...MAINLY
ALONG THE CO/NM BORDER DURING THE EVENING.
ON TUESDAY...MIDLVL RIDGE BUILDS TO THE NW OF THE FCST AREA. A WEAK
COOL FRONT IS EXPECTED TO MOVE DOWN THE PLAINS DURING THE DAY AND
THIS MAY ENHANCE THE SHOWER THREAT OVER THE PLAINS TUES
EVENING...ESPECIALLY ALONG THE PLAINS/MTN INTERFACE AND ONCE AGAIN
ALONG THE CO/NM BORDER.
THIS FRONT IS LIKELY GOING TO GET HUNG UP ALONG THE CO/NM BORDER.
THIS WILL KEEP THE PLAINS IN MOIST UPSLOPE FLOW ON WED. ALTHOUGH
FLOW WILL BE RELATIVELY WEAK ALOFT...WE SHOULD SEE ISOLD/SCTD
THUNDER ON THE PLAINS ONCE AGAIN WED AFTERNOON AND EVENING WITH
SOME SHOWERS AND STORMS OVER THE MTNS.
THU AND FRI...
THESE TWO DAYS APPEAR TO BE A BIT MORE ACTIVE AS A WEATHER SYSTEM
MOVES E-NE ACROSS THE SW CONUS AND OVER THE REGION LATER ON
FRIDAY. MOISTURE WILL BE ON THE INCREASE AS REINFORCING COOL
FRONTS WORK SOUTH ALONG THE PLAINS BRINGING UPSLOPE FLOW AND LLVL
MOISTURE. SHEAR AND INSTABILITY WILL BE ON THE INCREASE SO STORMS
THU AFTERNOON MAY BE A BIT STRONGER...AND ON FRIDAY WE MAY SEE
ENOUGH PARAMETERS COME INTO PLAY THAT WE WILL HAVE A ORGANIZED SVR
WEATHER THREAT. OVERALL...THESE TWO DAYS SHOULD BE WET GIVEN THE
FAVORABLE FORCING OVER THE REGION. THIS SYSTEM WILL ALSO LIKELY
BRING MORE HIGH MTN SNOWS...ESPECIALLY TO THE SAN JUANS AND
POSSIBLY SANGRE DE CRISTO MTNS.
FOR THE WEEKEND...MODEST W-NW FLOW ALOFT WILL PREVAIL. GFS HAS A LEE
TROUGH ALONG THE BORDER WHILE EC STILL HAS WEAK UPSLOPE FLOW OVER
THE FCST AREA. WE WILL LIKELY SEE SOME SHOWERS AND STORMS FOR THE
WEEKEND BUT WILL NOT BE AS MANY AS ON THU AND FRI.
AS FOR TEMPS THROUGH THE PERIOD...EXPECT MAX TEMPS ON THE PLAINS
TO RANGE FROM THE MID 60S TO MID 70S. DO NOT EXPECT ANY FIRE WX
ISSUES GIVEN THE RELATIVELY COOL TEMPS AND HIGHER RH AIR OVER THE
DISTRICT. /HODANISH
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1111 PM MDT SUN APR 19 2015
KALS...GENERALLY VFR CONDITIONS UNTIL LATE TONIGHT INTO MONDAY
MORNING AS SHOWERS WILL BE POSSIBLE AROUND THE SAN LUIS VALLEY
LOWERING CIGS AT THE TERMINAL. BREEZY NORTHWEST WINDS ARE EXPECTED
IN THE AFTERNOON WITH MORE WIDESPREAD SHOWER ACTIVITY...MORE
LIKELY TO IMPACT THE TERMINAL...AFTER 20Z.
KCOS...LIGHT PRECIPITATION IS LOWERING CIGS AROUND THE TERMINAL
WITH MODELS INDICATING THE BEST CHANCE FOR SNOW SHOWERS BETWEEN
11-13Z. EXPECT LOWERED CIGS TO CONTINUE INTO MONDAY MORNING BEFORE
IMPROVING THROUGHOUT THE AFTERNOON.
KPUB...A FEW SHOWERS ARE POSSIBLE AROUND THE TERMINAL PRODUCING
LOWERED CIGS TONIGHT...WITH A SMALL WINDOW AROUND 11Z OF SHOWERS
IMPACTING THE TERMINAL. EXPECTED IMPROVING CONDITIONS BY LATE
MORNING INTO MONDAY AFTERNOON. MOZLEY
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KT
SHORT TERM...MOORE
LONG TERM...HODANISH
AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS ALBANY NY
205 PM EDT MON APR 20 2015
.SYNOPSIS...
OCCASIONAL PERIODS OF RAIN ARE EXPECTED ACROSS EASTERN
NEW YORK AND WESTERN NEW ENGLAND THIS AFTERNOON INTO TONIGHT...AS A
LOW PRESSURE SYSTEM TRACKS INTO THE GREAT LAKES...AND A
FRONTAL SYSTEM ASSOCIATED WITH THE LOW APPROACHES FROM THE WEST.
EAST TO SOUTHEAST WINDS WILL BECOME STRONG AND GUSTY TODAY AHEAD OF
THE SYSTEM. A FEW RUMBLES OF THUNDER WILL BE POSSIBLE TONIGHT AS THE
FRONT PASSES. SOME BREAKS IN THE CLOUDS WILL DEVELOP TUESDAY
AFTERNOON BEHIND THE FRONT...OTHERWISE GENERALLY COOL AND SOMEWHAT
UNSETTLED CONDITIONS WILL PERSIST THROUGH THE REMAINDER OF THE WEEK
...AS A LARGE UPPER LEVEL LOW REMAINS ANCHORED NORTH OF THE GREAT
LAKES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1230 PM EDT...THE SURGE OF WARM ADVECTION PRECIPITATION
AHEAD OF THE WARM OVER THE UPPER MID ATLANTIC REGION IS MOVING
ACROSS THE SOUTHEAST PORTION OF THE FA WITH SCATTERED SHOWERS
ACROSS THE REMAINDER OF THE FA. ONGOING FORECAST IS IN PRETTY
GOOD SHAPE WITH JUST SOME RETOOLING OF THE POPS...AND HOURLY TEMPS
BASED ON THE RADAR AND OBSERVATIONS TRENDS. THERE IS GOOD SUPPORT
FROM THE LATEST HRRR FOR THE PCPN TO EXPAND NORTHWARD INTO THE
CAPITAL REGION...NRN CATSKILLS...MOHAWK VALLEY...SRN VT CORRIDOR.
SOME DOWNSLOPING DUE TO THE STRONG E/SE LLJ MAY LIMIT THE MODERATE
RAINFALL EXPANSION INTO THE UPPER HUDSON REGION...AND WEST OF THE
SRN GREENS. THE HIGHER TOTALS OF A THIRD TO TWO THIRDS OF AN INCH
OF RAINFALL ARE EXPECTED AND EAST OF THE CAPITAL REGION.
THE STEADIER RAIN SHOULD TAPER TO SHOWERS AND SOME DRIZZLE FOR
THIS AFTERNOON AS THE LOW LEVEL JET AND STRONGEST ISENTROPIC LIFT
PASS NORTH AND EAST OF THE REGION. SOUTH/EAST FACING HIGHER
ELEVATIONS WILL BE MOST PRONE TO MORE PERSISTENT SHOWERS AND
DRIZZLE THIS AFTERNOON.
GUSTY EAST/SOUTHEAST WINDS HAVE DEVELOPED LATE THIS MORNING AS
THE LOW LEVEL JET AND TIGHT PRESSURE GRADIENT PASS THROUGH. SOME
GUSTS OF 30-40 MPH HAVE BEEN NOTED AT KDDH AND KAQW. THE BEST
CHANCE FOR STRONGER WINDS TO MIX DOWN WILL BE ACROSS HIGHER
TERRAIN OF THE TACONICS...SOUTHERN GREEN MTNS...AND
BERKSHIRES...WHERE SOME GUSTS OF 50-55 MPH MAY OCCUR...ESP FROM
THE LATE MORNING THROUGH EARLY AFTERNOON. WIND GUSTS OF 35-45 MPH
WILL ALSO BE LIKELY ACROSS PORTIONS OF THE WESTERN
ADIRONDACKS...MOHAWK VALLEY AND EASTERN CATSKILLS. IN MOST VALLEY
AREAS...SOME WIND GUSTS OF 25-35 MPH COULD OCCUR EARLY THIS
MORNING AS THE RAIN INITIALLY REACHES THE GROUND. HOWEVER...THE
BOUNDARY LAYER SHOULD THEN STABILIZE ONCE WET BULB COOLING
OCCURS INTO THE AFTERNOON...DIMINISHING THE THREAT OF STRONGER
WINDS MIXING DOWN TO THE VALLEY FLOOR.
TEMPS WILL MAINLY BE IN THE 40S TO ABOUT 50F OVER THE HIGHER
TERRAIN...AND LOWER TO MID 50S IN THE VALLEY AREAS...EXCEPT IN THE
UPPER HUDSON REGION/LAKE GEORGE REGION AND PARTS OF SRN VT WHERE
SOME OF THE MAX TEMPS MAY ONLY REACH THE UPPER 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...A WARM FRONT WILL SLOWLY ATTEMPT TO LIFT NORTHWARD FROM
THE MID ATLANTIC STATES...AS A COLD/OCCLUDED FRONT APPROACHES FROM
THE GREAT LAKES REGION. ALTHOUGH THE PARENT LOW IS EXPECTED TO
TRACK ACROSS THE GREAT LAKES REGION TONIGHT...A WEAK TRIPLE POINT
LOW MAY FORM ALONG THE JUNCTION OF THE RETREATING WARM FRONT...AND
APPROACHING COLD FRONT FROM THE WEST...SOMEWHERE OVER SOUTH
CENTRAL PA. MODELS SUGGEST THAT SOME ELEVATED INSTABILITY...WITH
SHOWALTER INDICES DIPPING INTO THE -1C TO -3C RANGE OVERSPREADS AT
LEAST THE WESTERN AND SOUTHERN HALF OF THE REGION
OVERNIGHT...WHICH...IN COMBINATION WITH SYNOPTIC LIFT AHEAD OF THE
APPROACHING FRONTS...AND SOME QG FORCING AHEAD OF AN VORT LOBE
APPROACHING FROM THE SOUTHWEST...MAY ALLOW FOR A ROUND OF ELEVATED
CONVECTION LATER THIS EVENING AND OVERNIGHT...ESP FOR AREAS NEAR
AND SOUTH OF INTERSTATE 90. SO...SOME RUMBLES OF THUNDER ARE NOT
OUT OF THE QUESTION. ANY THUNDERSTORMS ARE EXPECTED TO REMAIN
NON-SEVERE ACROSS OUR REGION...WHICH IS IN AGREEMENT WITH LATEST
SPC DAY 1 OUTLOOK...WHICH KEEPS OUR AREA IN THE GENERAL THUNDER
REGION. HOWEVER...ANY THUNDERSTORMS THAT OCCUR OVERNIGHT COULD
HAVE LOCALLY HEAVY DOWNPOURS. TEMPS ARE EXPECTED TO HOLD NEARLY
STEADY MOST OF THE NIGHT...BEFORE FALLING INTO THE 40S CLOSER TO
DAYBREAK.
TUESDAY...SOME LINGERING SHOWERS WILL BE POSSIBLE IN THE MORNING
AS THE AFOREMENTIONED VORT LOBE SWINGS ACROSS. THEN...IT APPEARS
THAT OUR REGION WILL EXPERIENCE A PERIOD OF SUBSIDENCE IN THE
AFTERNOON HOURS...WHEN SOME BREAKS OF SUN COULD OCCUR. SOME LOW
LEVEL INSTABILITY COULD ALLOW FOR ISOLATED SHOWERS TO DEVELOP
LATER IN THE AFTERNOON...MAINLY ACROSS THE WESTERN ADIRONDACK
REGION. MAX TEMPS ARE FORECAST TO REACH THE LOWER/MID 60S IN
VALLEY AREAS AND 50S ACROSS HIGHER ELEVATIONS.
TUE NT-WED...ANOTHER REINFORCING COLD FRONT AND UPPER LEVEL
SHORTWAVE ARE EXPECTED TO CROSS THE REGION ON WED. WEAK RIDGING
JUST AHEAD OF THIS FEATURE MAY ALLOW FOR SOME BREAKS IN THE CLOUDS
TO CONTINUE INTO EARLY TUE NT...BEFORE CLOUDS REDEVELOP...AND
SHOWERS OVERSPREAD THE REGION DURING WED. BOUNDARY LAYER TEMPS MAY
BECOME QUITE CHILLY TUE NT/WED AM IF ENOUGH BREAKS IN THE CLOUDS
CAN DEVELOP...WITH WIDESPREAD LOW TEMPS IN THE 30S. ON
WED...DEPENDING ON THE TIMING OF SHOWER DEVELOPMENT...MAX TEMPS
COULD BRIEFLY REACH THE UPPER 50S TO LOWER 60S IN VALLEYS...BEFORE
FALLING ONCE SHOWERS OCCUR. FOR HIGHER ELEVATIONS...ONLY 40S ARE
EXPECTED. IN FACT...SOME WET SNOW AND/OR GRAUPEL COULD OCCUR
ACROSS THE SOUTHERN ADIRONDACKS AND HIGHER ELEVATIONS ACROSS THE
CATSKILLS AND WESTERN NEW ENGLAND BY LATE WED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
BELOW NORMAL TEMPERATURES AND INTERVALS OF SHOWERS AND SNOW SHOWERS
AS LARGE UPPER LOW AND ASSOCIATED EASTERN NORTH AMERICAN UPPER
TROUGHING CONTROLS THE WEATHER. THERE IS A GOOD CONSENSUS ON THE
LARGE SCALE UPPER LOW AND UPPER TROUGH BUT DISAGREEMENT ON THE TRACK
AND TIMING OF SMALL PIECES OF UPPER ENERGY ROTATING AROUND THE
PERIPHERY OF THE UPPER LOW...SOME OF WHICH ARE EXPECTED TO TRACK
THROUGH OR NEAR OUR REGION. SINCE THE CENTER OF THE UPPER LOW IS
EXPECTED TO TRACK NORTH OF THE REGION...OR ACROSS OUR NORTHERN
PORTION OF THE FORECAST AREA...THE DEEP FLOW ACROSS OUR REGION
SHOULD BE WEST...WHICH TYPICALLY RESULTS ISOLATED TO SCATTERED
COVERAGE OF SHOWERS AND SNOW SHOWERS. THE BEST COVERAGE ALSO IS
TYPICALLY IN LEE OF LAKE ONTARIO INTO THE SOUTHERN ADIRONDACKS AND
WESTERN MOHAWK VALLEY...AND ALSO INTO THE SOUTHERN GREEN MOUNTAINS
TO NORTHERN TACONICS DUE TO SOME UPSLOPE...BUT AGAIN JUST
SCATTERED.
DAYTIME PRECIPITATION TYPE LOOKS TO BE JUST RAIN SHOWERS...BUT
NIGHTTIME COULD SEE SOME SNOW SHOWER ACTIVITY...ESPECIALLY IN HIGHER
ELEVATIONS. THERE ARE ALSO HINTS AT SOME UPPER ENERGY POSSIBLY
INTERACTING WITH THE SOUTHERN STREAM NEXT WEEKEND THAT COULD SUPPORT
MORE ORGANIZED LOW PRESSURE AND MORE ORGANIZED PRECIPITATION...WITH
COLDER THAN NORMAL TEMPERATURES IN PLACE...WILL JUST WATCH
CAREFULLY.
NOT GETTING TO SPECIFIC ON TIMING OF INTERVALS OF SHOWERS/SNOW
SHOWERS DUE TO THE INCONSISTENCIES IN THE FINE DETAILS IN SOURCES OF
GUIDANCE...BUT THERE WILL BE PERIODS OF DRY WEATHER EVEN WITH THE
DOMINANCE OF ISOLATED TO SCATTERED SHOWERS/SNOW SHOWERS IN THE
FORECAST. THERE WILL ALSO BE SOME INTERVALS OF BREAKS IN THE CLOUDS
AND AGAIN...TRYING TO BROADBRUSH TIMING OF ANY CLOUDINESS VERSUS
BREAKS IN THE CLOUDS. HIGHS THURSDAY THROUGH SUNDAY LOOK TO BE IN
THE LOWER TO MID 50S...BUT 40S HIGHER ELEVATIONS...AND MAYBE BARELY
40 IN SOME PARTS OF THE SOUTHERN ADIRONDACKS. LOWS IN THE 20S AND
30S AT NIGHT WITH COLDEST TEMPERATURES IN HIGHER ELEVATIONS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
A LOW PRESSURE SYSTEM WILL CONTINUE TO MOVE INTO SOUTHERN ONTARIO
THIS AFTERNOON INTO TONIGHT. AN OCCLUDED FRONT WILL CONTINUE
PERIODS OF RAIN TONIGHT INTO TOMORROW MORNING.
FLIGHT CONDITIONS ARE GENERALLY LOW VFR/MVFR FOR THE E-CNTRL NY
AND WRN NEW ENGLAND TERMINALS. THERE HAVE BEEN SOME REDUCTIONS TO
IFR LEVELS AT KPOU IN TERMS OF VSBYS. THERE TREND WILL BE FOR THE
CIGS AND VSBYS TO LOWER TO MVFR/IFR LEVELS FOR KPOU/KPSF/KALB/KGFL
WITH THE FIRST BATCH OF RAIN MOVING THROUGH. THE BEST CHC OF IFR
CIGS/VSBYS BTWN 21Z-00Z WILL BE AT KPOU/KPSF.
A BRIEF LULL IN THE PCPN WILL LIKELY OCCUR BTWN 21Z-01Z WITH JUST
SOME DRIZZLE OR VERY LIGHT AROUND. ANOTHER DISTURBANCE AHEAD AN
OCCLUDED FRONTAL BOUNDARY WILL INCREASE THE THREAT OF WIDESPREAD
RAINFALL WITH SOME EMBEDDED RUMBLES OF THUNDER BTWN 01Z-04Z.
EXPECT WIDESPREAD LOW MVFR/IFR CONDITIONS. THE QUESTION WILL BE
HOW QUICKLY THE RAIN MOVES THROUGH...AND IT TRANSITIONS TO PERIODS
OF LIGHT RAIN AND DRIZZLE. DUE TO THE LOW STRATUS/RAIN AND DRIZZLE
IFR CIGS/VSBYS WERE FORECASTED PRIMARILY BTWN 06Z-14Z/TUE.
SLOW IMPROVEMENT IS EXPECTED TO LOW MVFR CONDITIONS BTWN 14Z-
16Z/TUE IN THE WAKE OF THE OCCLUDED FRONT.
LLWS GROUPS WERE KEPT IN UNTIL 21Z/MON AT KGFL/KPOU. THE BEST
LOW-LEVEL JET IS LIFTING NORTH AND EAST OF THE REGION. THE 2FT AGL
WINDS CONTINUE TO BE 30-35 KTS A FEW MORE HOURS.
THE E/SE WINDS CONTINUE AT 8-15 KFT AT KALB/KPSF...WITH SOME GUSTS
IN THE 20-25 KT RANGE. THE WINDS WILL GENERALLY BE FROM THE NE TO
SE AT 5-10 KTS AFTER 21Z...AND THE BE VARIABLE IN DIRECTION FROM
THE TO SOUTH TO SOUTHWEST AT 7 KTS OR LESS OVERNIGHT. THE WINDS
WILL INCREASE FROM THE W TO NW AT 8-12 KTS LATE TOMORROW MORNING
IN THE WAKE OF THE OCCLUDED FRONT.
OUTLOOK...
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THURSDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY TO SATURDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
&&
.FIRE WEATHER...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THE AREA TODAY AND
TONIGHT...WITH RAINFALL AMTS OF 0.75-1.5 INCHES EXPECTED. THE
WEATHER WILL BE COOL AND UNSETTLED FOR MUCH OF THE WEEK.
&&
.HYDROLOGY...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THE AREA TODAY AND
TONIGHT. EXPECTING WIDESPREAD QPF AMOUNTS OF AROUND AN INCH WITH
HIGHER AMOUNTS UP TO AROUND 1.5 INCHES WHERE THE RAINFALL IS
ENHANCED BY THE STRONG EAST TO SOUTHEAST FLOW...PARTICULARLY
ACROSS THE CENTRAL AND SOUTHEASTERN CATSKILLS...TACONICS...BERKSHIRES
INTO THE LITCHFIELD HILLS AND ACROSS SOUTHERN VERMONT. LOCALIZED
HIGHER AMOUNTS OF 2 TO 3 INCHES WILL BE POSSIBLE.
THERE IS STILL SOME SNOW COVER LEFT IN THE FORECAST AREA. BASED
ON NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
THIS IS ACROSS THE PORTIONS OF THE WESTERN ADIRONDACKS AND ACROSS
THE HIGHER TERRAIN OF THE SOUTHERN GREEN MOUNTAINS.
BASED ON CURRENT FORECASTS...ONLY THE WEST CANADA CREEK AT
HINCKLEY DAM IS EXPECTED TO EXCEED ITS FLOOD STAGE BY TUESDAY
EVENING.
THE REST OF THE WEEK THE FORECAST WILL BE DOMINATED BY A PERSISTENT
UPPER LEVEL TROUGH WHICH WILL RESULT IN COOL TEMPERATURES...BREEZY
CONDITIONS AND OCCASIONAL CHANCES FOR MAINLY LIGHT PRECIPITATION.
FOR DETAILS ON SPECIFIC AREA RIVER AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB-
SITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NYZ054-061.
MA...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR MAZ001-025.
VT...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR VTZ013-014.
&&
$$
SYNOPSIS...IAA/KL/WASULA
NEAR TERM...KL/11/WASULA
SHORT TERM...KL
LONG TERM...NAS
AVIATION...WASULA
FIRE WEATHER...IAA/KL
HYDROLOGY...IAA/KL
AREA FORECAST DISCUSSION
NWS ALBANY NY
1232 PM EDT MON APR 20 2015
.SYNOPSIS...
OCCASIONAL PERIODS OF RAIN ARE EXPECTED ACROSS EASTERN
NEW YORK AND WESTERN NEW ENGLAND THIS AFTERNOON INTO TONIGHT...AS A
LOW PRESSURE SYSTEM TRACKS INTO THE GREAT LAKES...AND A
FRONTAL SYSTEM ASSOCIATED WITH THE LOW APPROACHES FROM THE WEST.
EAST TO SOUTHEAST WINDS WILL BECOME STRONG AND GUSTY TODAY AHEAD OF
THE SYSTEM. A FEW RUMBLES OF THUNDER WILL BE POSSIBLE TONIGHT AS THE
FRONT PASSES. SOME BREAKS IN THE CLOUDS WILL DEVELOP TUESDAY
AFTERNOON BEHIND THE FRONT...OTHERWISE GENERALLY COOL AND SOMEWHAT
UNSETTLED CONDITIONS WILL PERSIST THROUGH THE REMAINDER OF THE WEEK
AS A LARGE UPPER LEVEL LOW REMAINS ANCHORED NORTH OF THE GREAT
LAKES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1230 PM EDT...THE SURGE OF WARM ADVECTION PRECIPITATION
AHEAD OF THE WARM OVER THE UPPER MID ATLANTIC REGION IS MOVING
ACROSS THE SOUTHEAST PORTION OF THE FA WITH SCATTERED SHOWERS
ACROSS THE REMAINDER OF THE FA. ONGOING FORECAST IS IN PRETTY
GOOD SHAPE WITH JUST SOME RETOOLING OF THE POPS...AND HOURLY TEMPS
BASED ON THE RADAR AND OBSERVATIONS TRENDS. THERE IS GOOD SUPPORT
FROM THE LATEST HRRR FOR THE PCPN TO EXPAND NORTHWARD INTO THE
CAPITAL REGION...NRN CATSKILLS...MOHAWK VALLEY...SRN VT CORRIDOR.
SOME DOWNSLOPING DUE TO THE STRONG E/SE LLJ MAY LIMIT THE MODERATE
RAINFALL EXPANSION INTO THE UPPER HUDSON REGION...AND WEST OF THE
SRN GREENS. THE HIGHER TOTALS OF A THIRD TO TWO THIRDS OF AN INCH
OF RAINFALL ARE EXPECTED AND EAST OF THE CAPITAL REGION.
THE STEADIER RAIN SHOULD TAPER TO SHOWERS AND SOME DRIZZLE FOR
THIS AFTERNOON AS THE LOW LEVEL JET AND STRONGEST ISENTROPIC LIFT
PASS NORTH AND EAST OF THE REGION. SOUTH/EAST FACING HIGHER
ELEVATIONS WILL BE MOST PRONE TO MORE PERSISTENT SHOWERS AND
DRIZZLE THIS AFTERNOON.
GUSTY EAST/SOUTHEAST WINDS HAVE DEVELOPED LATE THIS MORNING AS
THE LOW LEVEL JET AND TIGHT PRESSURE GRADIENT PASS THROUGH. SOME
GUSTS OF 30-40 MPH HAVE BEEN NOTED AT KDDH AND KAQW. THE BEST
CHANCE FOR STRONGER WINDS TO MIX DOWN WILL BE ACROSS HIGHER
TERRAIN OF THE TACONICS...SOUTHERN GREEN MTNS...AND
BERKSHIRES...WHERE SOME GUSTS OF 50-55 MPH MAY OCCUR...ESP FROM
THE LATE MORNING THROUGH EARLY AFTERNOON. WIND GUSTS OF 35-45 MPH
WILL ALSO BE LIKELY ACROSS PORTIONS OF THE WESTERN
ADIRONDACKS...MOHAWK VALLEY AND EASTERN CATSKILLS. IN MOST VALLEY
AREAS...SOME WIND GUSTS OF 25-35 MPH COULD OCCUR EARLY THIS
MORNING AS THE RAIN INITIALLY REACHES THE GROUND. HOWEVER...THE
BOUNDARY LAYER SHOULD THEN STABILIZE ONCE WET BULB COOLING
OCCURS INTO THE AFTERNOON...DIMINISHING THE THREAT OF STRONGER
WINDS MIXING DOWN TO THE VALLEY FLOOR.
TEMPS WILL MAINLY BE IN THE 40S TO ABOUT 50F OVER THE HIGHER
TERRAIN...AND LOWER TO MID 50S IN THE VALLEY AREAS...EXCEPT IN THE
UPPER HUDSON REGION/LAKE GEORGE REGION AND PARTS OF SRN VT WHERE
SOME OF THE MAX TEMPS MAY ONLY REACH THE UPPER 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...A WARM FRONT WILL SLOWLY ATTEMPT TO LIFT NORTHWARD FROM
THE MID ATLANTIC STATES...AS A COLD/OCCLUDED FRONT APPROACHES FROM
THE GREAT LAKES REGION. ALTHOUGH THE PARENT LOW IS EXPECTED TO
TRACK ACROSS THE GREAT LAKES REGION TONIGHT...A WEAK TRIPLE POINT
LOW MAY FORM ALONG THE JUNCTION OF THE RETREATING WARM FRONT...AND
APPROACHING COLD FRONT FROM THE WEST...SOMEWHERE OVER SOUTH
CENTRAL PA. MODELS SUGGEST THAT SOME ELEVATED INSTABILITY...WITH
SHOWALTER INDICES DIPPING INTO THE -1C TO -3C RANGE OVERSPREADS AT
LEAST THE WESTERN AND SOUTHERN HALF OF THE REGION
OVERNIGHT...WHICH...IN COMBINATION WITH SYNOPTIC LIFT AHEAD OF THE
APPROACHING FRONTS...AND SOME QG FORCING AHEAD OF AN VORT LOBE
APPROACHING FROM THE SOUTHWEST...MAY ALLOW FOR A ROUND OF ELEVATED
CONVECTION LATER THIS EVENING AND OVERNIGHT...ESP FOR AREAS NEAR
AND SOUTH OF INTERSTATE 90. SO...SOME RUMBLES OF THUNDER ARE NOT
OUT OF THE QUESTION. ANY THUNDERSTORMS ARE EXPECTED TO REMAIN
NON-SEVERE ACROSS OUR REGION...WHICH IS IN AGREEMENT WITH LATEST
SPC DAY 1 OUTLOOK...WHICH KEEPS OUR AREA IN THE GENERAL THUNDER
REGION. HOWEVER...ANY THUNDERSTORMS THAT OCCUR OVERNIGHT COULD
HAVE LOCALLY HEAVY DOWNPOURS. TEMPS ARE EXPECTED TO HOLD NEARLY
STEADY MOST OF THE NIGHT...BEFORE FALLING INTO THE 40S CLOSER TO
DAYBREAK.
TUESDAY...SOME LINGERING SHOWERS WILL BE POSSIBLE IN THE MORNING
AS THE AFOREMENTIONED VORT LOBE SWINGS ACROSS. THEN...IT APPEARS
THAT OUR REGION WILL EXPERIENCE A PERIOD OF SUBSIDENCE IN THE
AFTERNOON HOURS...WHEN SOME BREAKS OF SUN COULD OCCUR. SOME LOW
LEVEL INSTABILITY COULD ALLOW FOR ISOLATED SHOWERS TO DEVELOP
LATER IN THE AFTERNOON...MAINLY ACROSS THE WESTERN ADIRONDACK
REGION. MAX TEMPS ARE FORECAST TO REACH THE LOWER/MID 60S IN
VALLEY AREAS AND 50S ACROSS HIGHER ELEVATIONS.
TUE NT-WED...ANOTHER REINFORCING COLD FRONT AND UPPER LEVEL
SHORTWAVE ARE EXPECTED TO CROSS THE REGION ON WED. WEAK RIDGING
JUST AHEAD OF THIS FEATURE MAY ALLOW FOR SOME BREAKS IN THE CLOUDS
TO CONTINUE INTO EARLY TUE NT...BEFORE CLOUDS REDEVELOP...AND
SHOWERS OVERSPREAD THE REGION DURING WED. BOUNDARY LAYER TEMPS MAY
BECOME QUITE CHILLY TUE NT/WED AM IF ENOUGH BREAKS IN THE CLOUDS
CAN DEVELOP...WITH WIDESPREAD LOW TEMPS IN THE 30S. ON
WED...DEPENDING ON THE TIMING OF SHOWER DEVELOPMENT...MAX TEMPS
COULD BRIEFLY REACH THE UPPER 50S TO LOWER 60S IN VALLEYS...BEFORE
FALLING ONCE SHOWERS OCCUR. FOR HIGHER ELEVATIONS...ONLY 40S ARE
EXPECTED. IN FACT...SOME WET SNOW AND/OR GRAUPEL COULD OCCUR
ACROSS THE SOUTHERN ADIRONDACKS AND HIGHER ELEVATIONS ACROSS THE
CATSKILLS AND WESTERN NEW ENGLAND BY LATE WED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
BELOW NORMAL TEMPERATURES AND INTERVALS OF SHOWERS AND SNOW SHOWERS
AS LARGE UPPER LOW AND ASSOCIATED EASTERN NORTH AMERICAN UPPER
TROUGHING CONTROLS THE WEATHER. THERE IS A GOOD CONSENSUS ON THE
LARGE SCALE UPPER LOW AND UPPER TROUGH BUT DISAGREEMENT ON THE TRACK
AND TIMING OF SMALL PIECES OF UPPER ENERGY ROTATING AROUND THE
PERIPHERY OF THE UPPER LOW...SOME OF WHICH ARE EXPECTED TO TRACK
THROUGH OR NEAR OUR REGION. SINCE THE CENTER OF THE UPPER LOW IS
EXPECTED TO TRACK NORTH OF THE REGION...OR ACROSS OUR NORTHERN
PORTION OF THE FORECAST AREA...THE DEEP FLOW ACROSS OUR REGION
SHOULD BE WEST...WHICH TYPICALLY RESULTS ISOLATED TO SCATTERED
COVERAGE OF SHOWERS AND SNOW SHOWERS. THE BEST COVERAGE ALSO IS
TYPICALLY IN LEE OF LAKE ONTARIO INTO THE SOUTHERN ADIRONDACKS AND
WESTERN MOHAWK VALLEY...AND ALSO INTO THE SOUTHERN GREEN MOUNTAINS
TO NORTHERN TACONICS DUE TO SOME UPSLOPE...BUT AGAIN JUST
SCATTERED.
DAYTIME PRECIPITATION TYPE LOOKS TO BE JUST RAIN SHOWERS...BUT
NIGHTTIME COULD SEE SOME SNOW SHOWER ACTIVITY...ESPECIALLY IN HIGHER
ELEVATIONS. THERE ARE ALSO HINTS AT SOME UPPER ENERGY POSSIBLY
INTERACTING WITH THE SOUTHERN STREAM NEXT WEEKEND THAT COULD SUPPORT
MORE ORGANIZED LOW PRESSURE AND MORE ORGANIZED PRECIPITATION...WITH
COLDER THAN NORMAL TEMPERATURES IN PLACE...WILL JUST WATCH
CAREFULLY.
NOT GETTING TO SPECIFIC ON TIMING OF INTERVALS OF SHOWERS/SNOW
SHOWERS DUE TO THE INCONSISTENCIES IN THE FINE DETAILS IN SOURCES OF
GUIDANCE...BUT THERE WILL BE PERIODS OF DRY WEATHER EVEN WITH THE
DOMINANCE OF ISOLATED TO SCATTERED SHOWERS/SNOW SHOWERS IN THE
FORECAST. THERE WILL ALSO BE SOME INTERVALS OF BREAKS IN THE CLOUDS
AND AGAIN...TRYING TO BROADBRUSH TIMING OF ANY CLOUDINESS VERSUS
BREAKS IN THE CLOUDS. HIGHS THURSDAY THROUGH SUNDAY LOOK TO BE IN
THE LOWER TO MID 50S...BUT 40S HIGHER ELEVATIONS...AND MAYBE BARELY
40 IN SOME PARTS OF THE SOUTHERN ADIRONDACKS. LOWS IN THE 20S AND
30S AT NIGHT WITH COLDEST TEMPERATURES IN HIGHER ELEVATIONS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AN APPROACHING WARM FRONT AND A LOW PRESSURE SYSTEM WILL BRING A
WIDESPREAD SOAKING RAINFALL TO THE REGION FROM THIS MORNING
THROUGH TONIGHT.
VFR/LOW MVFR CONDITIONS SHOULD PERSIST THROUGH THE LATE
MORNING...AS RAIN HAS BEEN LIGHT AND THE ATMOSPHERE IS STILL
TAKING SOME TIME TO MOISTEN. CIGS WILL GRADUALLY LOWER...BUT
SHOULD REMAIN VFR THROUGH 14Z-16Z THIS MORNING. OCCASIONAL LIGHT
TO MODERATE RAIN SHOULD PREVAIL AFTER 14Z-16Z. RAIN INTENSITY
SHOULD WEAKEN BY MID TO LATE AFTERNOON BUT OCCASIONAL LIGHT RAIN
IS EXPECTED TO CONTINUE. CONDITIONS WILL GENERALLY DETERIORATE TO
MVFR ALTHOUGH SOME BRIEF IFR IS POSSIBLE BEFORE 00Z TUESDAY. AFTER
00Z... CEILINGS WILL CONTINUE TO LOWER TOWARD IFR BUT ENOUGH
UNCERTAINTY TO JUST INDICATE SCATTERED LAYER BELOW 1000 FEET WITH
CEILINGS AROUND 1000 FEET BETWEEN 00Z-12Z. VISIBILITIES WILL
CONTINUE MVFR WITH PERIODS OF LIGHT RAIN THROUGH THIS EVENING.
LOW LEVEL WIND SHEAR /LLWS/ IS EXPECTED AT KPSF/KPOU AND KGFL
THROUGH THE DAY AND WAS BEGUN AT 12Z...AS A STRONG SOUTHEAST JET
ALOFT MOVES OVERHEAD. SURFACE WINDS SHOULD BE STRONGER AND
OCCASIONALLY GUSTY AT KALB...SO WILL LEAVE OUT MENTION OF LLWS FOR
NOW. LLWS SHOULD END BY 00Z AS THE LOW LEVEL JET SEGMENT EXITS THE
REGION.
SURFACE WINDS WILL BE EAST-SOUTHEAST AROUND 10-16 KT BY THE LATE
MORNING. GUSTS COULD EXCEED 20-25 KT... ESPECIALLY AT KALB/KPSF.
WINDS REMAIN EAST TO SOUTHEAST THIS EVENING BUT DIMINISH TO 10 KT
OR LESS. WINDS WILL SHIFT TO SOUTHWEST AT 6 KT OR LESS LATER
TONIGHT.
OUTLOOK...
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THURSDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
&&
.FIRE WEATHER...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THE AREA TODAY AND
TONIGHT...WITH RAINFALL AMTS OF 0.75-1.5 INCHES EXPECTED. THE
WEATHER WILL BE COOL AND UNSETTLED FOR MUCH OF THE WEEK.
&&
.HYDROLOGY...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THE AREA TODAY AND
TONIGHT. EXPECTING WIDESPREAD QPF AMOUNTS OF AROUND AN INCH WITH
HIGHER AMOUNTS UP TO AROUND 1.5 INCHES WHERE THE RAINFALL IS
ENHANCED BY THE STRONG EAST TO SOUTHEAST FLOW...PARTICULARLY
ACROSS THE CENTRAL AND SOUTHEASTERN CATSKILLS...TACONICS...BERKSHIRES
INTO THE LITCHFIELD HILLS AND ACROSS SOUTHERN VERMONT. LOCALIZED
HIGHER AMOUNTS OF 2 TO 3 INCHES WILL BE POSSIBLE.
THERE IS STILL SOME SNOW COVER LEFT IN THE FORECAST AREA. BASED
ON NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
THIS IS ACROSS THE PORTIONS OF THE WESTERN ADIRONDACKS AND ACROSS
THE HIGHER TERRAIN OF THE SOUTHERN GREEN MOUNTAINS.
BASED ON CURRENT FORECASTS...ONLY THE WEST CANADA CREEK AT
HINCKLEY DAM IS EXPECTED TO EXCEED ITS FLOOD STAGE BY TUESDAY
EVENING.
THE REST OF THE WEEK THE FORECAST WILL BE DOMINATED BY A PERSISTENT
UPPER LEVEL TROUGH WHICH WILL RESULT IN COOL TEMPERATURES...BREEZY
CONDITIONS AND OCCASIONAL CHANCES FOR MAINLY LIGHT PRECIPITATION.
FOR DETAILS ON SPECIFIC AREA RIVER AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB-
SITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NYZ054-061.
MA...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR MAZ001-025.
VT...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR VTZ013-014.
&&
$$
SYNOPSIS...IAA/KL/WASULA
NEAR TERM...KL/11/WASULA
SHORT TERM...KL
LONG TERM...NAS
AVIATION...NAS/JPV
FIRE WEATHER...IAA/KL
HYDROLOGY...IAA/KL
AREA FORECAST DISCUSSION
NWS ALBANY NY
1031 AM EDT MON APR 20 2015
.SYNOPSIS...
OCCASIONAL PERIODS OF RAIN ARE EXPECTED ACROSS EASTERN
NEW YORK AND WESTERN NEW ENGLAND THIS AFTERNOON INTO TONIGHT...AS A
LOW PRESSURE SYSTEM TRACKS INTO THE GREAT LAKES...AND A
FRONTAL SYSTEM ASSOCIATED WITH THE LOW APPROACHES FROM THE WEST.
EAST TO SOUTHEAST WINDS WILL BECOME STRONG AND GUSTY TODAY AHEAD OF
THE SYSTEM. A FEW RUMBLES OF THUNDER WILL BE POSSIBLE TONIGHT AS THE
FRONT PASSES. SOME BREAKS IN THE CLOUDS WILL DEVELOP TUESDAY
AFTERNOON BEHIND THE FRONT...OTHERWISE GENERALLY COOL AND SOMEWHAT
UNSETTLED CONDITIONS WILL PERSIST THROUGH THE REMAINDER OF THE WEEK
...AS A LARGE UPPER LEVEL LOW REMAINS ANCHORED NORTH OF THE GREAT
LAKES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1030 AM EDT...THE SURGE OF WARM ADVECTION PRECIPITATION AHEAD
OF THE WARM OVER THE UPPER MID ATLANTIC REGION IS MOVING INTO THE
MID HUDSON VALLEY...SE CATSKILLS.. SRN TACONICS...SRN BERKS...AND
NW CT. SOME RAINFALL RATES ACROSS NRN NJ REACHED A QUARTER OF AN
INCH AN HOUR EARLIER THIS MORNING. NORTH OF THIS AREA...SCT
SHOWERS OR PERIODS OF LIGHT RAIN PERSIST. ONGOING FORECAST IS IN
PRETTY GOOD SHAPE WITH JUST SOME RETOOLING OF THE POPS...AND
HOURLY TEMPS BASED ON THE RADAR AND OBSERVATIONS TRENDS. THERE IS
GOOD SUPPORT FROM THE LATEST HRRR FOR THE PCPN TO EXPAND NORTHWARD
INTO THE CAPITAL REGION...NRN CATSKILLS...MOHAWK VALLEY...SRN VT
CORRIDOR. SOME DOWNSLOPING DUE TO THE STRONG E/SE LLJ MAY LIMIT
THE MODERATE RAINFALL EXPANSION INTO THE UPPER HUDSON REGION...AND
WEST OF THE SRN GREENS. THE HIGHER TOTALS OF A THIRD TO TWO THIRDS
OF AN INCH OF RAINFALL ARE EXPECTED SOUTH OF THE CAPITAL REGION.
THE STEADIER RAIN SHOULD TAPER TO SHOWERS AND SOME DRIZZLE FOR
THIS AFTERNOON AS THE LOW LEVEL JET AND STRONGEST ISENTROPIC LIFT
PASS NORTH AND EAST OF THE REGION. SOUTH/EAST FACING HIGHER
ELEVATIONS WILL BE MOST PRONE TO MORE PERSISTENT SHOWERS AND
DRIZZLE THIS AFTERNOON.
GUSTY EAST/SOUTHEAST WINDS HAVE DEVELOPED LATE THIS MORNING AS
THE LOW LEVEL JET AND TIGHT PRESSURE GRADIENT PASS THROUGH. SOME
GUSTS OF 30-40 MPH HAVE BEEN NOTED AT KDDH AND KAQW. THE BEST
CHANCE FOR STRONGER WINDS TO MIX DOWN WILL BE ACROSS HIGHER
TERRAIN OF THE TACONICS...SOUTHERN GREEN MTNS...AND
BERKSHIRES...WHERE SOME GUSTS OF 50-55 MPH MAY OCCUR...ESP FROM
THE LATE MORNING THROUGH EARLY AFTERNOON. WIND GUSTS OF 35-45 MPH
WILL ALSO BE LIKELY ACROSS PORTIONS OF THE WESTERN
ADIRONDACKS...MOHAWK VALLEY AND EASTERN CATSKILLS. IN MOST VALLEY
AREAS...SOME WIND GUSTS OF 25-35 MPH COULD OCCUR EARLY THIS
MORNING AS THE RAIN INITIALLY REACHES THE GROUND. HOWEVER...THE
BOUNDARY LAYER SHOULD THEN STABILIZE ONCE WET BULB COOLING
OCCURS INTO THE AFTERNOON...DIMINISHING THE THREAT OF STRONGER
WINDS MIXING DOWN TO THE VALLEY FLOOR.
TEMPS WILL MAINLY BE IN THE 40S TO ABOUT 50F OVER THE HIGHER
TERRAIN...AND LOWER TO MID 50S IN THE VALLEY AREAS...EXCEPT IN THE
UPPER HUDSON REGION/LAKE GEORGE REGION AND PARTS OF SRN VT WHERE
SOME OF THE MAX TEMPS MAY ONLY REACH THE UPPER 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...A WARM FRONT WILL SLOWLY ATTEMPT TO LIFT NORTHWARD FROM
THE MID ATLANTIC STATES...AS A COLD/OCCLUDED FRONT APPROACHES FROM
THE GREAT LAKES REGION. ALTHOUGH THE PARENT LOW IS EXPECTED TO
TRACK ACROSS THE GREAT LAKES REGION TONIGHT...A WEAK TRIPLE POINT
LOW MAY FORM ALONG THE JUNCTION OF THE RETREATING WARM FRONT...AND
APPROACHING COLD FRONT FROM THE WEST...SOMEWHERE OVER SOUTH
CENTRAL PA. MODELS SUGGEST THAT SOME ELEVATED INSTABILITY...WITH
SHOWALTER INDICES DIPPING INTO THE -1C TO -3C RANGE OVERSPREADS AT
LEAST THE WESTERN AND SOUTHERN HALF OF THE REGION
OVERNIGHT...WHICH...IN COMBINATION WITH SYNOPTIC LIFT AHEAD OF THE
APPROACHING FRONTS...AND SOME QG FORCING AHEAD OF AN VORT LOBE
APPROACHING FROM THE SOUTHWEST...MAY ALLOW FOR A ROUND OF ELEVATED
CONVECTION LATER THIS EVENING AND OVERNIGHT...ESP FOR AREAS NEAR
AND SOUTH OF INTERSTATE 90. SO...SOME RUMBLES OF THUNDER ARE NOT
OUT OF THE QUESTION. ANY THUNDERSTORMS ARE EXPECTED TO REMAIN
NON-SEVERE ACROSS OUR REGION...WHICH IS IN AGREEMENT WITH LATEST
SPC DAY 1 OUTLOOK...WHICH KEEPS OUR AREA IN THE GENERAL THUNDER
REGION. HOWEVER...ANY THUNDERSTORMS THAT OCCUR OVERNIGHT COULD
HAVE LOCALLY HEAVY DOWNPOURS. TEMPS ARE EXPECTED TO HOLD NEARLY
STEADY MOST OF THE NIGHT...BEFORE FALLING INTO THE 40S CLOSER TO
DAYBREAK.
TUESDAY...SOME LINGERING SHOWERS WILL BE POSSIBLE IN THE MORNING
AS THE AFOREMENTIONED VORT LOBE SWINGS ACROSS. THEN...IT APPEARS
THAT OUR REGION WILL EXPERIENCE A PERIOD OF SUBSIDENCE IN THE
AFTERNOON HOURS...WHEN SOME BREAKS OF SUN COULD OCCUR. SOME LOW
LEVEL INSTABILITY COULD ALLOW FOR ISOLATED SHOWERS TO DEVELOP
LATER IN THE AFTERNOON...MAINLY ACROSS THE WESTERN ADIRONDACK
REGION. MAX TEMPS ARE FORECAST TO REACH THE LOWER/MID 60S IN
VALLEY AREAS AND 50S ACROSS HIGHER ELEVATIONS.
TUE NT-WED...ANOTHER REINFORCING COLD FRONT AND UPPER LEVEL
SHORTWAVE ARE EXPECTED TO CROSS THE REGION ON WED. WEAK RIDGING
JUST AHEAD OF THIS FEATURE MAY ALLOW FOR SOME BREAKS IN THE CLOUDS
TO CONTINUE INTO EARLY TUE NT...BEFORE CLOUDS REDEVELOP...AND
SHOWERS OVERSPREAD THE REGION DURING WED. BOUNDARY LAYER TEMPS MAY
BECOME QUITE CHILLY TUE NT/WED AM IF ENOUGH BREAKS IN THE CLOUDS
CAN DEVELOP...WITH WIDESPREAD LOW TEMPS IN THE 30S. ON
WED...DEPENDING ON THE TIMING OF SHOWER DEVELOPMENT...MAX TEMPS
COULD BRIEFLY REACH THE UPPER 50S TO LOWER 60S IN VALLEYS...BEFORE
FALLING ONCE SHOWERS OCCUR. FOR HIGHER ELEVATIONS...ONLY 40S ARE
EXPECTED. IN FACT...SOME WET SNOW AND/OR GRAUPEL COULD OCCUR
ACROSS THE SOUTHERN ADIRONDACKS AND HIGHER ELEVATIONS ACROSS THE
CATSKILLS AND WESTERN NEW ENGLAND BY LATE WED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
BELOW NORMAL TEMPERATURES AND INTERVALS OF SHOWERS AND SNOW SHOWERS
AS LARGE UPPER LOW AND ASSOCIATED EASTERN NORTH AMERICAN UPPER
TROUGHING CONTROLS THE WEATHER. THERE IS A GOOD CONSENSUS ON THE
LARGE SCALE UPPER LOW AND UPPER TROUGH BUT DISAGREEMENT ON THE TRACK
AND TIMING OF SMALL PIECES OF UPPER ENERGY ROTATING AROUND THE
PERIPHERY OF THE UPPER LOW...SOME OF WHICH ARE EXPECTED TO TRACK
THROUGH OR NEAR OUR REGION. SINCE THE CENTER OF THE UPPER LOW IS
EXPECTED TO TRACK NORTH OF THE REGION...OR ACROSS OUR NORTHERN
PORTION OF THE FORECAST AREA...THE DEEP FLOW ACROSS OUR REGION
SHOULD BE WEST...WHICH TYPICALLY RESULTS ISOLATED TO SCATTERED
COVERAGE OF SHOWERS AND SNOW SHOWERS. THE BEST COVERAGE ALSO IS
TYPICALLY IN LEE OF LAKE ONTARIO INTO THE SOUTHERN ADIRONDACKS AND
WESTERN MOHAWK VALLEY...AND ALSO INTO THE SOUTHERN GREEN MOUNTAINS
TO NORTHERN TACONICS DUE TO SOME UPSLOPE...BUT AGAIN JUST
SCATTERED.
DAYTIME PRECIPITATION TYPE LOOKS TO BE JUST RAIN SHOWERS...BUT
NIGHTTIME COULD SEE SOME SNOW SHOWER ACTIVITY...ESPECIALLY IN HIGHER
ELEVATIONS. THERE ARE ALSO HINTS AT SOME UPPER ENERGY POSSIBLY
INTERACTING WITH THE SOUTHERN STREAM NEXT WEEKEND THAT COULD SUPPORT
MORE ORGANIZED LOW PRESSURE AND MORE ORGANIZED PRECIPITATION...WITH
COLDER THAN NORMAL TEMPERATURES IN PLACE...WILL JUST WATCH
CAREFULLY.
NOT GETTING TO SPECIFIC ON TIMING OF INTERVALS OF SHOWERS/SNOW
SHOWERS DUE TO THE INCONSISTENCIES IN THE FINE DETAILS IN SOURCES OF
GUIDANCE...BUT THERE WILL BE PERIODS OF DRY WEATHER EVEN WITH THE
DOMINANCE OF ISOLATED TO SCATTERED SHOWERS/SNOW SHOWERS IN THE
FORECAST. THERE WILL ALSO BE SOME INTERVALS OF BREAKS IN THE CLOUDS
AND AGAIN...TRYING TO BROADBRUSH TIMING OF ANY CLOUDINESS VERSUS
BREAKS IN THE CLOUDS. HIGHS THURSDAY THROUGH SUNDAY LOOK TO BE IN
THE LOWER TO MID 50S...BUT 40S HIGHER ELEVATIONS...AND MAYBE BARELY
40 IN SOME PARTS OF THE SOUTHERN ADIRONDACKS. LOWS IN THE 20S AND
30S AT NIGHT WITH COLDEST TEMPERATURES IN HIGHER ELEVATIONS.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AN APPROACHING WARM FRONT AND A LOW PRESSURE SYSTEM WILL BRING A
WIDESPREAD SOAKING RAINFALL TO THE REGION FROM THIS MORNING
THROUGH TONIGHT.
VFR/LOW MVFR CONDITIONS SHOULD PERSIST THROUGH THE LATE
MORNING...AS RAIN HAS BEEN LIGHT AND THE ATMOSPHERE IS STILL
TAKING SOME TIME TO MOISTEN. CIGS WILL GRADUALLY LOWER...BUT
SHOULD REMAIN VFR THROUGH 14Z-16Z THIS MORNING. OCCASIONAL LIGHT
TO MODERATE RAIN SHOULD PREVAIL AFTER 14Z-16Z. RAIN INTENSITY
SHOULD WEAKEN BY MID TO LATE AFTERNOON BUT OCCASIONAL LIGHT RAIN
IS EXPECTED TO CONTINUE. CONDITIONS WILL GENERALLY DETERIORATE TO
MVFR ALTHOUGH SOME BRIEF IFR IS POSSIBLE BEFORE 00Z TUESDAY. AFTER
00Z... CEILINGS WILL CONTINUE TO LOWER TOWARD IFR BUT ENOUGH
UNCERTAINTY TO JUST INDICATE SCATTERED LAYER BELOW 1000 FEET WITH
CEILINGS AROUND 1000 FEET BETWEEN 00Z-12Z. VISIBILITIES WILL
CONTINUE MVFR WITH PERIODS OF LIGHT RAIN THROUGH THIS EVENING.
LOW LEVEL WIND SHEAR /LLWS/ IS EXPECTED AT KPSF/KPOU AND KGFL
THROUGH THE DAY AND WAS BEGUN AT 12Z...AS A STRONG SOUTHEAST JET
ALOFT MOVES OVERHEAD. SURFACE WINDS SHOULD BE STRONGER AND
OCCASIONALLY GUSTY AT KALB...SO WILL LEAVE OUT MENTION OF LLWS FOR
NOW. LLWS SHOULD END BY 00Z AS THE LOW LEVEL JET SEGMENT EXITS THE
REGION.
SURFACE WINDS WILL BE EAST-SOUTHEAST AROUND 10-16 KT BY THE LATE
MORNING. GUSTS COULD EXCEED 20-25 KT... ESPECIALLY AT KALB/KPSF.
WINDS REMAIN EAST TO SOUTHEAST THIS EVENING BUT DIMINISH TO 10 KT
OR LESS. WINDS WILL SHIFT TO SOUTHWEST AT 6 KT OR LESS LATER
TONIGHT.
OUTLOOK...
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THURSDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
&&
.FIRE WEATHER...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THE AREA TODAY AND
TONIGHT...WITH RAINFALL AMTS OF 0.75-1.5 INCHES EXPECTED. THE
WEATHER WILL BE COOL AND UNSETTLED FOR MUCH OF THE WEEK.
&&
.HYDROLOGY...
A WIDESPREAD SOAKING RAINFALL WILL OCCUR ACROSS THE AREA TODAY AND
TONIGHT. EXPECTING WIDESPREAD QPF AMOUNTS OF AROUND AN INCH WITH
HIGHER AMOUNTS UP TO AROUND 1.5 INCHES WHERE THE RAINFALL IS
ENHANCED BY THE STRONG EAST TO SOUTHEAST FLOW...PARTICULARLY
ACROSS THE CENTRAL AND SOUTHEASTERN CATSKILLS...TACONICS...BERKSHIRES
INTO THE LITCHFIELD HILLS AND ACROSS SOUTHERN VERMONT. LOCALIZED
HIGHER AMOUNTS OF 2 TO 3 INCHES WILL BE POSSIBLE.
THERE IS STILL SOME SNOW COVER LEFT IN THE FORECAST AREA. BASED
ON NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
THIS IS ACROSS THE PORTIONS OF THE WESTERN ADIRONDACKS AND ACROSS
THE HIGHER TERRAIN OF THE SOUTHERN GREEN MOUNTAINS.
BASED ON CURRENT FORECASTS...ONLY THE SCHOHARIE CREEK AT GILBOA
DAM IS FORECAST TO REACH ITS FLOOD STAGE AND THE WEST CANADA CREEK
AT HINCKLEY DAM TO EXCEED ITS FLOOD STAGE BOTH BY TUESDAY EVENING.
THE REST OF THE WEEK THE FORECAST WILL BE DOMINATED BY A PERSISTENT
UPPER LEVEL TROUGH WHICH WILL RESULT IN COOL TEMPERATURES...BREEZY
CONDITIONS AND OCCASIONAL CHANCES FOR MAINLY LIGHT PRECIPITATION.
FOR DETAILS ON SPECIFIC AREA RIVER AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB-
SITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NYZ054-061.
MA...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR MAZ001-025.
VT...WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR VTZ013-014.
&&
$$
SYNOPSIS...IAA/KL/WASULA
NEAR TERM...KL/WASULA
SHORT TERM...KL
LONG TERM...NAS
AVIATION...NAS/JPV
FIRE WEATHER...IAA/KL
HYDROLOGY...IAA/KL
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
641 PM EDT MON APR 20 2015
.SYNOPSIS...
A WARM FRONT JUST NORTHWEST OF INTERSTATE 95 WILL MERGE WITH AN
EASTWARD MOVING COLD FRONT AND PUSH OUT TO SEA BY MORNING. SEVERAL
REINFORCING COLD FRONTS WILL MOVE SOUTHEAST THROUGH THE MID ATLANTIC
STATES TUESDAY, WEDNESDAY AND THURSDAY AFTERNOONS. LOW PRESSURE
WILL CROSS TO THE SOUTH OF THE AREA SATURDAY INTO SATURDAY NIGHT.
HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE WEST THROUGH THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
630 PM ESTF: NOT MUCH CHANGE FROM THE 455 PM ESTF. THE HRRR CONTINUES
THE DEVELOPMENT SO WE HOLD ONTO THAT FOR NOW AND THE 12Z SPCWRF IS
NOT TOO BAD, THOUGH IT APPEARS A TOUCH FAST.
KRDG HAD 38 KT AT 2227Z. VERY GOOD FOR A SMALL STORM WITH ELEVATED
ROATION AND PREVIOUS NORTHERLY FLOW.
QSTNRY FRONT JUST NW OF I95. STRONGEST STORMS ANTICIPATED ALONG
OR EAST OF THAT LATE THIS EVENING.
SPC CONTINUES THE TORNADO WATCH FOR THE WRN/SWRN PARTS OF THE REGION
UNTIL 10 PM. MORE SHOWERS AND SCT TSTMS WITH FROPA AROUND MIDNIGHT
WEST -- 03 AM EAST. WINDS SHIFT WRLY BEHIND THE FRNT AND PRECIP
ENDS MOST AREAS BY DAWN.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
DEEP LOW PRESSURE REMAIN ACROSS CANADA WHILE HIGH PRESSURE BUILDS
OVER THE SE STATES. RATHER STRONG PRESSURE GRADIENT WILL CREATE
MODERATE/GUSTY WINDS TUE. MOSTLY FAIR WEATHER IS EXPECTED.
TEMPERATURES WILL BE SEASONABLY COOL WITH HIGHS IN THE LOW/MID 60S
MOST AREAS. WEST WINDS 10 TO 15 MPH WITH GUSTS UP TO 20 MPH DURING
THE AFTERNOON.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
A PERSISTENT UPPER LEVEL TROUGH WILL SPIN OVER THE GREAT LAKES AREA
WITH A GRADUAL PUSH TO EAST THROUGH THE WEEK, SETTLING OVER EXTREME
NORTHEASTERN UNITED STATES AND SPINNING ACROSS EASTERN CANADA
THROUGH THE WEEKEND. SEVERAL SHORTWAVES EMBEDDED IN THE UPPER LEVEL
FLOW WILL ROTATE THROUGH OUR AREA AND WE WILL SEE SHOWERS CROSS
PARTS OF THE REGION THROUGH THE WEEK.
A COLD FRONT WILL PUSH DOWN THROUGH THE REGION WEDNESDAY INTO
WEDNESDAY NIGHT, WITH A CHANCE FOR SOME SHOWERS ACROSS THE AREA.
COLDER AIR LOCATED ALONG AND BEHIND THE FRONT MAY ALLOW FOR SOME
SNOW FLAKES TO FALL ACROSS THE HIGHER TERRAIN OF THE SOUTHERN
POCONOS.
A SECOND COLD FRONT IS FORECAST TO ARRIVE BY THURSDAY EVENING BUT IT
APPEARS TO LACK MUCH MOISTURE. THEREFORE, ONLY A FEW LIGHT SHOWERS
ACROSS THE NORTHWESTERN AREAS MAY OCCUR AS THE MOISTURE LESSENS AS
IT PUSHES THROUGH THE REGION.
THE UPPER LOW FINALLY MOVES EASTWARD BUT THE CYCLONIC FLOW WILL
REMAIN ACROSS THE REGION INTO THE WEEKEND WITH A CHANCE FOR SHOWERS
CONTINUING.
THE MODELS ARE SHOWING THAT A LOW PRESSURE SYSTEM WILL CROSS TO THE
SOUTH OF THE REGION DURING THE WEEKEND. JUST HOW FAR NORTH THE
SYSTEM GETS WILL DICTATE WHETHER OR NOT WE SEE SHOWERS PUSH
NORTHWARD INTO OUR SOUTHERN AREAS. WE HAVE INCLUDED JUST A SLIGHT
CHANCE FOR SOME SHOWERS FOR SATURDAY AND SATURDAY NIGHT ACROSS THE
SOUTHERN PORTION OF THE FORECAST AREA.
HIGH PRESSURE WILL THEN BUILD IN FROM THE WEST FOR SUNDAY AND MONDAY
WITH A DRY PERIOD EXPECTED ACROSS OUR REGION.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY, AND SURROUNDING AREAS.
THROUGH TONIGHT...TAFS HAVE UPDATED WITH SOME TIMING OF POTENTIALLY
STRONGER TSTMS AND GUSTY WINDS PER HRRR. FIRST STORM VCNTY KRDG
HAD A WEST GUST 38 KT AT 2227Z.
IFR CIGS NW OF THE QSTRY FRONT, ESPECIALLY KABE. ELSEWHERE, VFR
CIGS WITH A PERIOD OF IFR CONDS IN SHOWERS AND TSTMS TONIGHT.
LIGHT WINDS, MOSTLY NE-SE NW OF THE QSTRY FNT AND SOUTHERLY
GUSTING TO 15 KT SOUTH OF THE FRONT. ALL WINDS TURNING WNW
OVERNIGHT POST LATE NIGHT CFP.
TUE...VFR SCT-BKN AOA 4500 FT WITH GUSTY W WINDS 20-25 KT.
OUTLOOK...
TUESDAY NIGHT...MAINLY VFR CONDITIONS EXPECTED.
WEDNESDAY...MAINLY VFR CONDITIONS EXPECTED WITH SUB-VFR SHOWERS
POSSIBLE AS A COLD FRONT CROSSES THE REGION.
THURSDAY THROUGH SATURDAY...MAINLY VFR CONDITIONS EXPECTED.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE ACROSS THE OCEAN AREAS THE REST OF
TODAY...TONIGHT AND INTO TUESDAY. SCA FOR SEAS INTO TONIGHT AND
THEN WINDS AND SEAS TUE. SCT TSTMS TONIGHT AND THEN FAIR WEATHER
TUE. AREAS OF FOG INTO TONIGHT.
SUB-SCA CONDITIONS ACROSS DEL BAY ATTM WITH PROBABLE HIGHER WAVES
ACROSS THE MOUTH OF THE BAY AND POSSIBLY SOME HIGHER SEAS UP ACROSS
THE SRN PART OF THE BAY. WE WILL KEEP THE SCA FLAG FOR AWHILE INTO
THE EVENING BUT DROP IT ACROSS NRN DEL BAY. IT MAY NEED TO BE ISSUED
THERE AGAIN FOR WINDS G25 FOR TUESDAY. SCT TSTMS TONIGHT BUT FAIR
WEATHER FOR TUE.
OUTLOOK...
WEDNESDAY...SEAS WILL INCREASE AND NEAR 5 FEET DURING THE
AFTERNOON BUT SHOULD SUBSIDE FAIRLY QUICKLY. WINDS WILL GUST
AROUND 20 KNOTS. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR A TIME
ON WEDNESDAY.
THURSDAY...SUB- ADVISORY CONDITIONS ARE EXPECTED ON THE AREA
WATERS.
FRIDAY...WINDS WILL BE GUSTY OUT OF THE NORTHWEST AND A SMALL
CRAFT ADVISORY MAY BE NEEDED.
SATURDAY...SUB- ADVISORY CONDITIONS ARE EXPECTED ON THE AREA
WATERS.
&&
.EQUIPMENT...
WILL TRY TO RESTORE PHL NWR SHORTLY. ITS OUTAGE SINCE ABOUT 557P.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ431-450>455.
&&
$$
SYNOPSIS...MEOLA
NEAR TERM...DRAG/O`HARA 641 PM
SHORT TERM...O`HARA
LONG TERM...MEOLA
AVIATION...DRAG/MEOLA/O`HARA 641PM
MARINE...DRAG/MEOLA/O`HARA
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
629 PM EDT MON APR 20 2015
.SYNOPSIS...
A WARM FRONT JUST NORTHWEST OF INTERSTATE 95 WILL MERGE WITH AN
EASTWARD MOVING COLD FRONT AND PUSH OUT TO SEA BY MORNING. SEVERAL
REINFORCING COLD FRONTS WILL MOVE SOUTHEAST THROUGH THE MID ATLANTIC
STATES TUESDAY, WEDNESDAY AND THURSDAY AFTERNOONS. LOW PRESSURE
WILL CROSS TO THE SOUTH OF THE AREA SATURDAY INTO SATURDAY NIGHT.
HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE WEST THROUGH THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
630 PM ESTF: NOT MUCH CHANGE FROM THE 455 PM ESTF...THOUGH
CONFIDENCE ON STRONG TSTMS IS A LITTLE LESS THAN WHAT I`D LIKE,
BASED ON DEVELOPMENTS THROUGH 6 PM. THE HRRR CONTINUES THE
DEVELOPMENT SO WE HOLD ONTO THAT FOR NOW AND THE 12Z SPCWRF IS
NOT TOO BAD, THOUGH IT APPEARS A TOUCH FAST.
QSTNRY FRONT JUST NW OF I95. STRONGEST STORMS ANTICIPATED ALONG
OR EAST OF THAT LATE THIS EVENING.
SPC CONTINUES THE TORNADO WATCH FOR THE WRN/SWRN PARTS OF THE REGION
UNTIL 10 PM. MORE SHOWERS AND SCT TSTMS WITH FROPA AROUND MIDNIGHT
WEST -- 03 AM EAST. WINDS SHIFT WRLY BEHIND THE FRNT AND PRECIP
ENDS MOST AREAS BY DAWN.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
DEEP LOW PRESSURE REMAIN ACROSS CANADA WHILE HIGH PRESSURE BUILDS
OVER THE SE STATES. RATHER STRONG PRESSURE GRADIENT WILL CREATE
MODERATE/GUSTY WINDS TUE. MOSTLY FAIR WEATHER IS EXPECTED.
TEMPERATURES WILL BE SEASONABLY COOL WITH HIGHS IN THE LOW/MID 60S
MOST AREAS. WEST WINDS 10 TO 15 MPH WITH GUSTS UP TO 20 MPH DURING
THE AFTERNOON.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
A PERSISTENT UPPER LEVEL TROUGH WILL SPIN OVER THE GREAT LAKES AREA
WITH A GRADUAL PUSH TO EAST THROUGH THE WEEK, SETTLING OVER EXTREME
NORTHEASTERN UNITED STATES AND SPINNING ACROSS EASTERN CANADA
THROUGH THE WEEKEND. SEVERAL SHORTWAVES EMBEDDED IN THE UPPER LEVEL
FLOW WILL ROTATE THROUGH OUR AREA AND WE WILL SEE SHOWERS CROSS
PARTS OF THE REGION THROUGH THE WEEK.
A COLD FRONT WILL PUSH DOWN THROUGH THE REGION WEDNESDAY INTO
WEDNESDAY NIGHT, WITH A CHANCE FOR SOME SHOWERS ACROSS THE AREA.
COLDER AIR LOCATED ALONG AND BEHIND THE FRONT MAY ALLOW FOR SOME
SNOW FLAKES TO FALL ACROSS THE HIGHER TERRAIN OF THE SOUTHERN
POCONOS.
A SECOND COLD FRONT IS FORECAST TO ARRIVE BY THURSDAY EVENING BUT IT
APPEARS TO LACK MUCH MOISTURE. THEREFORE, ONLY A FEW LIGHT SHOWERS
ACROSS THE NORTHWESTERN AREAS MAY OCCUR AS THE MOISTURE LESSENS AS
IT PUSHES THROUGH THE REGION.
THE UPPER LOW FINALLY MOVES EASTWARD BUT THE CYCLONIC FLOW WILL
REMAIN ACROSS THE REGION INTO THE WEEKEND WITH A CHANCE FOR SHOWERS
CONTINUING.
THE MODELS ARE SHOWING THAT A LOW PRESSURE SYSTEM WILL CROSS TO THE
SOUTH OF THE REGION DURING THE WEEKEND. JUST HOW FAR NORTH THE
SYSTEM GETS WILL DICTATE WHETHER OR NOT WE SEE SHOWERS PUSH
NORTHWARD INTO OUR SOUTHERN AREAS. WE HAVE INCLUDED JUST A SLIGHT
CHANCE FOR SOME SHOWERS FOR SATURDAY AND SATURDAY NIGHT ACROSS THE
SOUTHERN PORTION OF THE FORECAST AREA.
HIGH PRESSURE WILL THEN BUILD IN FROM THE WEST FOR SUNDAY AND MONDAY
WITH A DRY PERIOD EXPECTED ACROSS OUR REGION.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY, AND SURROUNDING AREAS.
THROUGH TONIGHT...TAFS HAVE UPDATED WITH SOME TIMING OF POTENTIALLY
STRONGER TSTMS AND GUSTY WINDS PER HRRR. FIRST STORM NOW AT KRDG.
IFR CIGS NW OF THE QSTRY FRONT, ESPECIALLY KABE. ELSEWHERE, VFR
CIGS WITH A PERIOD OF IFR CONDS IN SHOWERS AND TSTMS TONIGHT.
LIGHT WINDS, MOSTLY NE-SE NW OF THE QSTRY FNT AND SOUTHERLY
GUSTING TO 15 KT SOUTH OF THE FRONT. ALL WINDS TURNING WNW
OVERNIGHT POST LATE NIGHT CFP.
TUE...VFR SCT-BKN AOA 4500 FT WITH GUSTY W WINDS 20-25 KT.
OUTLOOK...
TUESDAY NIGHT...MAINLY VFR CONDITIONS EXPECTED.
WEDNESDAY...MAINLY VFR CONDITIONS EXPECTED WITH SUB-VFR SHOWERS
POSSIBLE AS A COLD FRONT CROSSES THE REGION.
THURSDAY THROUGH SATURDAY...MAINLY VFR CONDITIONS EXPECTED.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE ACROSS THE OCEAN AREAS THE REST OF
TODAY...TONIGHT AND INTO TUESDAY. SCA FOR SEAS INTO TONIGHT AND
THEN WINDS AND SEAS TUE. SCT TSTMS TONIGHT AND THEN FAIR WEATHER
TUE. AREAS OF FOG INTO TONIGHT.
SUB-SCA CONDITIONS ACROSS DEL BAY ATTM WITH PROBABLE HIGHER WAVES
ACROSS THE MOUTH OF THE BAY AND POSSIBLY SOME HIGHER SEAS UP ACROSS
THE SRN PART OF THE BAY. WE WILL KEEP THE SCA FLAG FOR AWHILE INTO
THE EVENING BUT DROP IT ACROSS NRN DEL BAY. IT MAY NEED TO BE ISSUED
THERE AGAIN FOR WINDS G25 FOR TUESDAY. SCT TSTMS TONIGHT BUT FAIR
WEATHER FOR TUE.
OUTLOOK...
WEDNESDAY...SEAS WILL INCREASE AND NEAR 5 FEET DURING THE
AFTERNOON BUT SHOULD SUBSIDE FAIRLY QUICKLY. WINDS WILL GUST
AROUND 20 KNOTS. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR A TIME
ON WEDNESDAY.
THURSDAY...SUB- ADVISORY CONDITIONS ARE EXPECTED ON THE AREA
WATERS.
FRIDAY...WINDS WILL BE GUSTY OUT OF THE NORTHWEST AND A SMALL
CRAFT ADVISORY MAY BE NEEDED.
SATURDAY...SUB- ADVISORY CONDITIONS ARE EXPECTED ON THE AREA
WATERS.
&&
.EQUIPMENT...
WILL TRY TO RESTORE PHL NWR SHORTLY. ITS OUTAGE SINCE ABOUT 557P.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ431-450>455.
&&
$$
SYNOPSIS...MEOLA
NEAR TERM...DRAG/O`HARA 630
SHORT TERM...O`HARA
LONG TERM...MEOLA
AVIATION...DRAG/MEOLA/O`HARA 630
MARINE...DRAG/MEOLA/O`HARA
EQUIPMENT...DRAG 630
AREA FORECAST DISCUSSION...UPDATED
NWS TAMPA BAY RUSKIN FL
919 PM EDT TUE APR 21 2015
.UPDATE...
A SHARP MOISTURE GRADIENT EXISTS THIS EVENING ACROSS THE CWA AS
PWAT VALUES ACROSS THE NORTHERN EXTENT OF THE CWA ARE AOB 1 INCH
THIS EVENING WHILE DOWN ACROSS SW FLORIDA VALUES ARE NEAR 2 INCHES.
THIS SHARP GRADIENT IS ASSOCIATED WITH A NEARLY STATIONARY FRONT
DRAPED ACROSS THE PENINSULA. 00Z KTBW SOUNDING IS MUCH DRIER COMPARED
TO THIS MORNING ESPECIALLY IN THE LOWER LEVELS AS THE PWAT VALUE
OBSERVED WAS 1.07 INCHES.
FORECAST TONIGHT IS TRICKY AS A SHORTWAVE OVER THE EASTERN GULF
CONTINUES TO MOVE TOWARDS THE SOUTHERN PART OF THE FL PENINSULA.
WITH AMPLE MOISTURE IN PLACE AND ENHANCED LIFT...STAGE APPEARS
SET FOR DECENT SHOWER CHANCES FOR THE OVERNIGHT ACROSS THE SOUTHERN
ZONES. RAISED POPS ACROSS THE SOUTHERN PORTION OF THE CWA TO ACCOUNT
FOR THIS FORECAST THINKING. BIG QUESTION IS HOW FAR NORTH TO GO WITH
POPS? MOST RECENT HRRR RUN KEEPS AREAS SOUTH OF THE BAY DRY
OVERNIGHT AND I AGREE WITH THIS THINKING GIVEN THE FAIRLY DRY
ATMOSPHERE OBSERVED FROM THE EVENING RAOB. UPDATED ZONES AND GRIDS
TO BE SENT SHORTLY.
&&
.AVIATION...
VFR GENERALLY EXPECTED ALTHOUGH SOME BRIEF MVFR CIGS/VSBYS MAY BE
POSSIBLE ACROSS SOUTHERN TERMINALS AS PERIODS OF HEAVIER RAIN MAY
CAUSE LOCALIZED RESTRICTIONS.
&&
.MARINE...
A COOL FRONT WILL BECOME STATIONARY OVER SOUTH FLORIDA THROUGH
WEDNESDAY KEEPING UNSETTLED WEATHER IN THE FORECAST. BY THURSDAY
ANOTHER COOL FRONT WILL APPROACH THE COASTAL WATERS AND PASS
THROUGH THE STATE INCREASING WINDS FOR SATURDAY OVER THE NORTHERN
WATERS...OTHERWISE WINDS ARE NOT EXPECTED TO REACH ADVISORY
LEVELS. NO CHANGES NEEDED FOR THE EVENING UPDATE.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 69 85 72 84 / 10 20 20 40
FMY 71 88 71 87 / 30 60 20 30
GIF 68 88 69 86 / 10 40 20 50
SRQ 68 84 71 82 / 20 30 20 30
BKV 61 87 63 85 / 10 20 20 40
SPG 69 85 73 82 / 10 20 20 40
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION...11/MCKAUGHAN
MARINE...11/MCKAUGHAN
DECISION SUPPORT...57/MCMICHAEL
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1035 AM EDT MON APR 20 2015
.DISCUSSION...
...STRONG TO ISOLATED SEVERE STORMS POSSIBLE THIS AFTERNOON AND
EVENING...
LATEST RADAR AND LIGHTNING IMAGERY SHOWS SQUALL LINE OVER THE NRN
AND CENTRAL GULF SHIFTING EASTWARD OUT AHEAD OF WEAK FRONT MOVING
INTO THE SOUTHEAST STATES. TRACK ESTIMATES HAS THIS LINE NEARING THE
WEST CENTRAL FL COAST BY EARLY THIS AFT. MID/HIGH LEVEL DEBRIS
CLOUDS FROM THIS CONVECTION ALREADY MOVING ACROSS THE REGION WHICH
WILL LIMIT DAYTIME HEATING TODAY. HOWEVER SHOULD STILL SEE ENOUGH
FILTERED SUNSHINE FOR HIGHS TO REACH THE MID TO UPPER 80S INTO
EARLY/MID AFT. DECENT HEATING...DEEP MOISTURE AND MARGINALLY
FAVORABLE DYNAMIC SUPPORT FROM SUBTROPICAL JET MAY ALLOW THIS LINE
TO MAINTAIN ENOUGH STRENGTH TO HOLD TOGETHER AS IT INITIALLY MOVES
ONSHORE. THE POTENTIAL FOR STRONG TO ISO SEVERE WIND GUSTS WILL
ACCOMPANY THIS CONVECTIVE BAND AS IT MOVES TOWARD LAKE COUNTY AND I-
4 CORRIDOR. STORM PREDICTION CENTER HAS PLACED THIS REGION UNDER A
SLIGHT RISK IN THE LATEST DAY 1 UPDATE. IN ADDITION TO WIND...HAIL
UP TO QUARTER SIZE WILL ALSO BE A CONCERN AS MORNING SOUNDINGS SHOW
COOLER TEMPS ALOFT WITH -10 TO -12C AT 500MB.
IN ADDITION TO THIS LINE...HRRR/WRF MODELS SHOW ADDITIONAL SCT-NMRS
SHOWERS AND STORMS DEVELOPING OUT AHEAD OF THIS SYSTEM AND PUSHING E-
NE ACROSS THE AREA INTO THE AFT HOURS. THESE STORMS COULD ALSO BRING
WITH THEM THREAT FOR STRONG WIND GUSTS AND SMALL HAIL...ESPECIALLY
WITH BOUNDARY INTERACTIONS TOWARD THE COAST IF THE EAST COAST SEA
BREEZE IS ABLE TO FORM. THEREFORE HIGH POPS UP TO 70-80 PERCENT
TODAY STILL LOOK GOOD WITH NO MAJOR CHANGES TO THE FORECAST PLANNED.
&&
.AVIATION...VFR THROUGH THE MORNING. INCREASING COVERAGE OF
SHRA/TSRA INTO THE AFT WITH APPROACHING SQUALL LINE OVER THE GULF
AND ADDITIONAL SCT-NMRS CONVECTION THAT FORMS OUT AHEAD OF THIS LINE
THAT BOTH THE WRF AND HRRR MODELS INDICATE. STRONG TO ISO SEVERE
WIND GUSTS AND HAIL POSSIBLE WITH ANY STORMS TODAY. TEMPO IFR/MVFR
CONDS WILL OCCUR WITH ANY CONVECTION TODAY WITH BEST TIMEFRAME FOR
THIS ACTIVITY BTW 18-00Z.
&&
.MARINE...
TODAY-TONIGHT...(PREVIOUS DISCUSSION) SOUTH TO SOUTHWEST WINDS
AROUND 10 KNOTS NEARSHORE AND 10 TO 15 KNOTS OFFSHORE. SEAS 2 TO 3
FEET NEARSHORE AND 3 TO 4 FEET WELL OFFSHORE. SCATTERED TO NUMEROUS
AFTERNOON WEST TO EAST MOVING SHOWERS AND STORMS. FAST MOVING...20
TO 30 MPH...STORMS AGAIN. BOATERS SHOULD KEEP AN EYE TO THE WEST FOR
FAST APPROACHING STORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 85 67 81 62 / 80 50 20 10
MCO 86 67 86 68 / 80 50 30 20
MLB 87 68 82 70 / 80 50 40 20
VRB 88 69 82 69 / 70 50 40 20
LEE 85 67 84 67 / 80 40 20 20
SFB 86 67 85 65 / 80 50 20 20
ORL 86 68 85 68 / 80 50 30 20
FPR 88 69 83 69 / 70 50 50 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
WEITLICH/KELLY
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
425 AM EDT MON APR 20 2015
.NEAR TERM [THROUGH TODAY]...
AT 08 UTC, A LARGE CLUSTER OF THUNDERSTORMS WAS BEGINNING TO
DEVELOP UPSTREAM NEAR COASTAL LOUISIANA; THIS WILL LIKELY BE THE
NEXT ROUND OF STORMS TO AFFECT THE AREA LATER THIS MORNING. THE
STORMS WERE DEVELOPING JUST AHEAD OF AN ADVANCING COLD FRONT AND
IN THE LEFT EXIT REGION OF A STRONG 120-140 KNOT UPPER LEVEL JET.
BOTH HI-RES AND GLOBAL MODELS ARE IN GOOD AGREEMENT IN ADVANCING
THIS CONVECTION INTO OUR AREA LARGELY BETWEEN 12 UTC AND 18 UTC,
ALTHOUGH SLIGHT TIMING DIFFERENCES (+/- 2 HOURS) STILL EXIST. THEY
ALSO AGREE THAT THE BULK OF THE CONVECTION WILL BE CONCENTRATED
OVER THE SOUTHERN HALF OF OUR FORECAST AREA - PRIMARILY OUR
FLORIDA ZONES AND PERHAPS THE SOUTHERN ROW OR TWO OF GEORGIA
ZONES. WE ADDED LIKELY POPS OF 60 TO 70 PERCENT IN THOSE AREAS FOR
THE MORNING HOURS. THE QUESTION THEN BECOMES WHAT THE WARM SECTOR
WILL LOOK LIKE THIS AFTERNOON AS THE SYNOPTIC COLD FRONT BEGINS TO
ARRIVE IN OUR AREA. MODELS THAT MAINTAIN SOME INSTABILITY IN THE
NORTHERN HALF OF OUR AREA AFTER THE MORNING ROUND OF CONVECTION
ARE INDICATING MORE AFTERNOON CONVECTION, AS WOULD BE EXPECTED.
THEREFORE, AFTERNOON RAIN CHANCES WILL BE TIED TO HOW THINGS
UNFOLD THIS MORNING. FOR NOW WE PLACED 20 TO 30 PERCENT POPS IN
THE NORTHERN HALF OF OUR AREA THIS AFTERNOON.
THE UPSTREAM STORMS APPEAR TO BE DEVELOPING IN THE CUSP OF A PLUME
OF STEEPER MID-LEVEL LAPSE RATES ASSOCIATED WITH AN ELEVATED MIXED
LAYER, BASED ON THE LATEST RAP ANALYSIS AND 00Z SOUNDINGS FROM THE
WESTERN GULF COAST. AS INCREASING ASCENT LEADS TO SOME MID-LEVEL
COOLING, AND THE EML PROPAGATES EAST, LAPSE RATES SHOULD STEEPEN
ACROSS OUR AREA EARLY THIS MORNING. MODEL FORECAST SOUNDINGS SHOW 7
C/KM 700-500MB LAPSE RATES AT TLH BY 12-15Z. COMBINED WITH THE LOW-
LEVEL MOISTURE IN PLACE ACROSS THE AREA, THIS IS EXPECTED TO
GENERATE CAPE VALUES ON THE ORDER OF 2000-2500 J/KG, WHICH WILL ALSO
COINCIDE WITH 0-6KM BULK SHEAR VALUES AROUND 50 KNOTS. ALL OF THESE
ARE INDICATORS OF A FAVORABLE ENVIRONMENT FOR SEVERE STORMS:
ORGANIZED CONVECTIVE LINES (WHICH SEEMS LIKE IT WILL BE THE DOMINANT
MODE THIS MORNING) OR SUPERCELLS. STRAIGHT-LINE HODOGRAPHS THIS
MORNING WOULD FAVOR SPLITTING SUPERCELLS IF THEY WERE TO OCCUR, AND
IN A HIGHLY SHEARED ENVIRONMENT WITH STEEP LAPSE RATES AND LOW WET-
BULB ZERO HEIGHTS (~8500 FT) LARGE HAIL WOULD BE A GREATER THREAT.
THEREFORE, THIS MORNING WE EXPECT THE MAIN THREATS TO BE ASSOCIATED
WITH LARGE HAIL AND DAMAGING WINDS. IF ISOLATED TO SCATTERED STORMS
CAN DEVELOP IN THE AFTERNOON ALONG THE COLD FRONT, SUPERCELLS WOULD
AGAIN BE POSSIBLE AND GREATER LOW LEVEL SHEAR WOULD MEAN THAT
ISOLATED TORNADOES WOULD ALSO BE A THREAT IN ADDITION TO HAIL AND
WINDS. HOWEVER, NEW CONVECTION MAY BE FIGHTING BOTH DIMINISHED
INSTABILITY AND INCREASINGLY DRY MID-LEVEL AIR WHICH CAN DILUTE
UPDRAFT STRENGTH. THEREFORE, CONFIDENCE IS LOWER FOR BOTH RAIN
CHANCES AND SEVERE WEATHER CHANCES IN THE AFTERNOON.
TO RECAP: MORNING ROUND OF STORMS IS LIKELY - MAINLY SOUTH. SOME OF
THOSE MAY BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS. THE
COMBINATION OF STRONG INSTABILITY AND STRONG SHEAR IS A BIT UNUSUAL,
SO A SIGNIFICANT SEVERE REPORT OR TWO CAN`T BE RULED OUT. IN THE
AFTERNOON, ISOLATED STORMS MAY REDEVELOP - ESPECIALLY NORTH. THE
CHANCES OF SEVERE WEATHER MAY BE LOWER AFTER 18 UTC.
.SHORT TERM [TONIGHT THROUGH WEDNESDAY]...
THE SEVERE THREAT SHOULD PRETTY MUCH BE OVER BY TONIGHT WITH JUST
SOME ISOLATED TO SCATTERED SHOWERS AND STORMS OVER OUR EASTERN ZONES
UNTIL AROUND MIDNIGHT. WE WILL THEN FINALLY COME UNDER THE INFLUENCE
OF SURFACE HIGH PRESSURE WHICH WILL BRING US A RARE TWO-DAY STRETCH
WITHOUT APPRECIABLE POPS, AND SOME SUNSHINE AND LOWER HUMIDITY TO
BOOT. TEMPERATURES WILL BE MUCH CLOSER TO SEASONAL LEVELS AS WELL,
ESPECIALLY AT NIGHT.
.LONG TERM [WEDNESDAY NIGHT THROUGH MONDAY]...
RAIN CHANCES AND NIGHTTIME TEMPERATURES WILL GRADUALLY CREEP UP ONCE
AGAIN AS SURFACE HIGH PRESSURE MOVES EAST OF THE AREA AND OUR FLOW
BECOMES ONSHORE ONCE AGAIN. DAYTIME HIGHS WILL GENERALLY BE IN THE
LOWER 80S. THE SOUTHERN BRANCH OF THE JET WILL CONTINUE TO PULL
IMPULSES OF ENERGY ACROSS THE REGION AS A SURFACE FRONT SETS UP JUST
NORTH OF THE REGION, OCCASIONALLY DIPPING INTO OUR NORTHERN ZONES.
THESE FEATURES AND THE SEA BREEZE WILL GENERATED SCATTERED
THUNDERSTORMS EACH DAY. SHEAR AND INSTABILITY LOOK SUFFICIENT FOR
SOME SOME STRONG STORMS ON THURSDAY WITH SEVERE STORMS POSSIBLE
FRIDAY AND SATURDAY.
&&
.AVIATION...
[THROUGH 06Z TUESDAY] SOME LOW CIGS AND PATCHY FOG WILL BE POSSIBLE
THIS MORNING AT ALL TERMINAL SITES WITH IFR CONDITIONS LIKELY FOR A
TIME AND LIFR POSSIBLE. CONDITIONS SHOULD IMPROVE TO MVFR-VFR AFTER
ABOUT 14-15 UTC OVERALL. HOWEVER, TEMPORARY VIS RESTRICTIONS IN
THUNDERSTORMS WILL BE POSSIBLE. ONE ROUND OF STORMS WILL MOVE IN
DURING THE MORNING HOURS - REACHING ECP AROUND 13 UTC, TLH AROUND 15
UTC, AND VLD AROUND 16 UTC (+/- 2 HOURS AT EACH SITE). SOME OF THESE
STORMS COULD BE QUITE STRONG AND PRODUCE HAIL OR BRIEF GUSTS IN
EXCESS OF 30 KNOTS. ISOLATED STORMS MAY REDEVELOP IN THE AFTERNOON,
AFFECTING MAINLY DHN AND ABY.
&&
.MARINE...
STRONG TO SEVERE STORMS WILL BE POSSIBLE TODAY ACROSS THE WATERS.
EVEN OUTSIDE OF THUNDERSTORMS, WINDS ARE EXPECTED TO REACH
CAUTIONARY LEVELS AT TIMES TODAY AND TONIGHT BEFORE DIMINISHING ON
TUESDAY AS HIGH PRESSURE MOVES EAST ALONG THE COAST. THIS HIGH WILL
THEN MOVE OFF THE EAST COAST OF FLORIDA AND BRING A PERIOD OF LIGHT
ONSHORE WINDS FROM WEDNESDAY THROUGH FRIDAY.
&&
.FIRE WEATHER...
WETTING RAINS ARE EXPECTED TODAY ACROSS PRIMARILY THE SOUTHERN HALF
OF THE AREA (FLORIDA ZONES AND THE SOUTHERN ROW OF ZONES IN
GEORGIA). RH WILL STAY ABOVE 60 PERCENT IN MOST AREAS. DRIER AIR
WILL ARRIVE TOMORROW, BUT IT SHOULD NOT BE SUFFICIENTLY DRY FOR RED
FLAG CONDITIONS AND FUEL MOISTURES SHOULD STILL BE HIGH. RAIN
CHANCES AND HIGHER RH RETURN BY THURSDAY.
&&
.HYDROLOGY...
MINOR FLOODING IS OCCURRING ALONG PARTS OF THE CHOCTAWHATCHEE RIVER
AND IS EXPECTED TO CONTINUE. BRUCE IS FORECAST TO EVENTUALLY REACH
MODERATE FLOOD STAGE IN A COUPLE OF DAYS, ALBEIT JUST BARELY. MINOR
FLOODING IS ALSO OCCURRING ON THE KINCHAFOONEE CREEK AT DAWSON. THE
APALACHICOLA RIVER AT BLOUNTSTOWN IS NOW FORECAST TO CREST JUST
BARELY BELOW FLOOD STAGE, BUT THAT COULD QUICKLY CHANGE IF MORE RAIN
FALLS IN THE BASIN THAN THE CURRENTLY PREDICTED HALF INCH FOR
TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TALLAHASSEE 81 62 82 57 85 / 70 20 10 10 10
PANAMA CITY 78 63 76 63 79 / 70 10 0 10 10
DOTHAN 78 57 77 56 81 / 30 10 0 10 10
ALBANY 78 58 78 55 82 / 50 10 0 10 10
VALDOSTA 80 61 79 55 84 / 60 20 10 10 10
CROSS CITY 83 64 82 58 84 / 70 30 10 10 10
APALACHICOLA 79 65 79 63 81 / 70 20 10 10 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH LATE TONIGHT FOR COASTAL BAY-
COASTAL GULF-SOUTH WALTON.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...WOOL
LONG TERM...WOOL
AVIATION...LAMERS
MARINE...WOOL
FIRE WEATHER...WOOL
HYDROLOGY...WOOL
AREA FORECAST DISCUSSION
NWS LINCOLN IL
900 PM CDT TUE APR 21 2015
.UPDATE...
ISSUED AT 855 PM CDT TUE APR 21 2015
LATEST SURFACE ANALYSIS INDICATING A WEAK COLD FRONT MAKING ITS
WAY SOUTHEAST ACROSS THE FORECAST AREA THIS EVENING. AIR MASS
AHEAD OF AND BEHIND THE BOUNDARY WAS QUITE DRY WITH ONLY SOME
LIGHT SHOWERS BEING REPORTED OVER PARTS OF EXTREME EAST CENTRAL
IOWA INTO FAR WESTERN IL. WEAK SHORTWAVE NOTED ON THE WATER VAPOR
LOOP WILL STREAK ACROSS THE AREA TONIGHT BRINGING A LIMITED AMOUNT
OF LIFT AND JUST ENOUGH MOISTURE TO PRODUCE SOME WIDELY SCATTERED
SHOWERS. ANY THREAT OF RAIN OVER FAR EAST CENTRAL AND SOUTHEAST
ILLINOIS SHOULD SHIFT OFF TO OUR EAST BY MORNING WITH ANOTHER
CHILLY AIR MASS SPILLING SOUTHEAST INTO OUR AREA ACCOMPANIED BY
GUSTY NORTHWEST WINDS...ALTHOUGH THE WINDS TOMORROW ARE NOT
EXPECTED TO BE AS GUSTY AS TODAY AS A FEW SITES OVER OUR NORTHERN
COUNTIES TOPPED OUT AROUND 45 MPH AT TIMES LATE THIS MORNING INTO
THE AFTERNOON HOURS. HAVE MADE SOME ADJUSTMENTS TO THE GRIDS WITH
RESPECT TO PRECIP WORDING AND TEMPERATURES FOR THE OVERNIGHT
HOURS. THE UPDATED ZFP SHOULD BE OUT BY 915 PM.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 300 PM CDT TUE APR 21 2015
COLD FRONT EXTENDING FROM NORTHERN LAKE MICHIGAN TO JUST NORTH OF
KANSAS CITY EARLY THIS AFTERNOON. QUITE A BIT OF DRY AIR MIXING DOWN
TO THE SURFACE...RESULTING IN DEW POINTS IN THE LOWER 20S AND EVEN
SOME UPPER TEENS ACROSS THE NORTH HALF OF THE CWA...WHERE WINDS HAVE
ALSO BEEN GUSTING 35-45 MPH. FRONTAL PASSAGE IS EXPECTED IN OUR AREA
DURING THE EVENING...WITH A FEW SHOWERS POSSIBLE ASSOCIATED WITH AN
UPPER DISTURBANCE STREAMING SOUTHEAST OUT OF SOUTH DAKOTA/IOWA. WITH
THE AMOUNT OF DRY AIR AT THE LOWER LEVELS...THERE WILL BE SOME
STRUGGLE TO MOISTEN THE ATMOSPHERE ENOUGH...WITH FORECAST SOUNDINGS
REMAINING RATHER DRY BELOW ABOUT 3000 FEET. HAVE CONTINUED TO
MENTION POP`S OF AROUND 30% MAINLY IN THE CENTRAL AND SOUTHERN
CWA...WITH SOME MINOR REFINEMENTS TO THE HOURLY VALUES. SKIES SHOULD
QUICKLY CLEAR ONCE THE SHOWERS MOVE OUT...BUT REMAIN MOSTLY CLOUDY
ACROSS THE SOUTHEAST MUCH OF THE NIGHT. ALTHOUGH LOWS IN THE FAR
NORTHERN CWA EXPECTED TO DIP INTO THE MID 30S IN SOME AREAS...AM NOT
EXPECTING FROST TONIGHT AS WINDS SHOULD GENERALLY STAY UP AROUND 10
MPH OVERNIGHT.
.LONG TERM...(WEDNESDAY THROUGH TUESDAY)
ISSUED AT 300 PM CDT TUE APR 21 2015
A BREEZY AND COOL DAY AHEAD WEDNESDAY DESPITE MORE SUNSHINE AS
CLOUDS DECREASE WED MORNING OVER SOUTHEAST IL. HIGHS IN THE MID 50S
CENTRAL IL AND UPPER 50S IN SOUTHEAST IL FROM I-70 SOUTHEAST. THESE
TEMPERATURES ARE ABOUT 10 DEGREES BELOW NORMAL FOR LATE APRIL.
FORECAST CONCERN IS POSSIBLITY OF FROST WEDNESDAY AND THURDAY NIGHT
ESPECIALLY NORTH OF I-70 AS GROWING SEASON HAS BEGUN ACROSS
ILLINOIS. STRONG CUTOFF LOW NEAR EASTERN LAKE SUPERIOR SLOWLY PIVOTS
EASTWARD INTO EASTERN ONTARIO AND WESTERN QUEBEC WEDNESDAY NIGHT AND
THURSDAY. MEANWHILE CANADIAN HIGH PRESSURE RIDGE TO NOSE INTO THE
MID MS RIVER VALLEY DIMINISHING WINDS AND CLOUDS. WITH DRY AIRMASS
IN PLACE, THIS WILL ALLOW A COUPLE OF COOL NIGHTS AHEAD. WEDNESDAY
NIGHT APPEARS TO BE THE COOLEST NIGHT ACROSS THE AREA WITH LOWS IN
THE LOW TO MID 30S (NEAR FREEZING TEMPS FROM I-74 NORTH) AND FROST
LIKELY OVERNIGHT INTO EARLY THU MORNING. FROST AND FREEZE HEADLINES
MAY EVENTUALLY BE NEEDED OVERNIGHT WED NIGHT. SURFACE CANADIAN RIDGE
ONLY SLOWLY SHIFTS EAST OF IL BY FRIDAY MORNING SO THINK FROST WILL
AGAIN BE POSSIBLE OVER EASTERN IL OVERNIGHT THU NIGHT INTO EARLY FRI
MORNING WITH LOWS IN THE MID 30S AFTER HIGHS REACH UPPER 50S AND
LOWER 60S ON THURSDAY (MILDEST IN SW CWA).
12Z MEDIUM RANGE MODELS EJECT A SURFACE AND CUTOFF LOW FROM CO TO MO
BY SATURDAY MORNING. THINK MOST AREAS WILL STILL STAY DRY ON FRIDAY
AND ONLY HAVE SLIGHT CHANCES OF LIGHT SHOWERS FAR WESTERN/SW AREAS
LATER FRIDAY AFTERNOON WITH CLOUDS INCREASING DURING THE DAY FRIDAY
FROM THE WSW. HIGHS FRIDAY IN THE LOWER 60S ACROSS MOST OF THE
REGION. HAVE LIKELY CHANCES OF SHOWERS FRIDAY NIGHT INTO SATURDAY
WITH HIGHEST CHANCES SOUTHERN AREAS WHERE ISOLATED THUNDERSTORMS
POSSIBLE. JUST SLIGHT CHANCES OF LIGHT RAIN SHOWERS IN SOUTHEAST IL
SATURDAY EVENING THEN DRY REST OF THE WEEKEND. COOLER HIGHS SAT IN
THE 50S WHILE MORE SUNSHINE SUNDAY RETURNS HIGHS BACK INTO THE LOWER
60S.
THE 12Z EXTENDED FORECAST MODELS HAVE ANOTHER WEATHER SYSTEM
EJECTING OUT OF THE SOUTHERN PLAINS ON MONDAY INTO TUESDAY. THIS
BRINGS NEXT CHANCE OF RAIN SHOWERS AND RAINFALL AMOUNTS FAIRLY LIGHT
DUE TO GULF OF MEXICO BEING CUTOFF.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 602 PM CDT TUE APR 21 2015
VFR CONDITIONS ARE EXPECTED THRU THIS TAF PERIOD. A WEAK COLD
FRONT LOCATED OVER PARTS OF EAST CENTRAL IOWA WILL TRACK ACROSS
THE AREA TONIGHT BRINGING SOME SCATTERED LIGHT SHOWERS WITH IT
WITH BKN-OVC CIGS BETWEEN 3500 AND 4500 FEET. LATEST RAP FORECAST
SOUNDINGS BACKING OFF A BIT WITH THE PRECIP OVER THE PAST FEW
RUNS BUT STILL HOLDING WITH A BRIEF PERIOD OF LOW VFR CIGS ALONG
THE COLD FRONT. THE GUSTY WEST TO NORTHWEST WINDS WILL DIMINISH
RATHER QUICKLY AFTER SUNSET WITH A LIGHT WEST TO NORTHWEST WIND
EXPECTED OVERNIGHT WITH SPEEDS OF 7 TO 12 KTS. THOSE WINDS WILL
BECOME NORTHWEST AND INCREASE IN SPEED ON WEDNESDAY TO BETWEEN
15 AND 25 KTS WITH A FEW GUSTS UP TO 30 KTS AT TIMES BEFORE
DIMINISHING QUICKLY TOWARDS SUNSET.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...GEELHART
LONG TERM...07
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
608 PM CDT TUE APR 21 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 300 PM CDT TUE APR 21 2015
COLD FRONT EXTENDING FROM NORTHERN LAKE MICHIGAN TO JUST NORTH OF
KANSAS CITY EARLY THIS AFTERNOON. QUITE A BIT OF DRY AIR MIXING DOWN
TO THE SURFACE...RESULTING IN DEW POINTS IN THE LOWER 20S AND EVEN
SOME UPPER TEENS ACROSS THE NORTH HALF OF THE CWA...WHERE WINDS HAVE
ALSO BEEN GUSTING 35-45 MPH. FRONTAL PASSAGE IS EXPECTED IN OUR AREA
DURING THE EVENING...WITH A FEW SHOWERS POSSIBLE ASSOCIATED WITH AN
UPPER DISTURBANCE STREAMING SOUTHEAST OUT OF SOUTH DAKOTA/IOWA. WITH
THE AMOUNT OF DRY AIR AT THE LOWER LEVELS...THERE WILL BE SOME
STRUGGLE TO MOISTEN THE ATMOSPHERE ENOUGH...WITH FORECAST SOUNDINGS
REMAINING RATHER DRY BELOW ABOUT 3000 FEET. HAVE CONTINUED TO
MENTION POP`S OF AROUND 30% MAINLY IN THE CENTRAL AND SOUTHERN
CWA...WITH SOME MINOR REFINEMENTS TO THE HOURLY VALUES. SKIES SHOULD
QUICKLY CLEAR ONCE THE SHOWERS MOVE OUT...BUT REMAIN MOSTLY CLOUDY
ACROSS THE SOUTHEAST MUCH OF THE NIGHT. ALTHOUGH LOWS IN THE FAR
NORTHERN CWA EXPECTED TO DIP INTO THE MID 30S IN SOME AREAS...AM NOT
EXPECTING FROST TONIGHT AS WINDS SHOULD GENERALLY STAY UP AROUND 10
MPH OVERNIGHT.
.LONG TERM...(WEDNESDAY THROUGH TUESDAY)
ISSUED AT 300 PM CDT TUE APR 21 2015
A BREEZY AND COOL DAY AHEAD WEDNESDAY DESPITE MORE SUNSHINE AS
CLOUDS DECREASE WED MORNING OVER SOUTHEAST IL. HIGHS IN THE MID 50S
CENTRAL IL AND UPPER 50S IN SOUTHEAST IL FROM I-70 SOUTHEAST. THESE
TEMPERATURES ARE ABOUT 10 DEGREES BELOW NORMAL FOR LATE APRIL.
FORECAST CONCERN IS POSSIBLITY OF FROST WEDNESDAY AND THURDAY NIGHT
ESPECIALLY NORTH OF I-70 AS GROWING SEASON HAS BEGUN ACROSS
ILLINOIS. STRONG CUTOFF LOW NEAR EASTERN LAKE SUPERIOR SLOWLY PIVOTS
EASTWARD INTO EASTERN ONTARIO AND WESTERN QUEBEC WEDNESDAY NIGHT AND
THURSDAY. MEANWHILE CANADIAN HIGH PRESSURE RIDGE TO NOSE INTO THE
MID MS RIVER VALLEY DIMINISHING WINDS AND CLOUDS. WITH DRY AIRMASS
IN PLACE, THIS WILL ALLOW A COUPLE OF COOL NIGHTS AHEAD. WEDNESDAY
NIGHT APPEARS TO BE THE COOLEST NIGHT ACROSS THE AREA WITH LOWS IN
THE LOW TO MID 30S (NEAR FREEZING TEMPS FROM I-74 NORTH) AND FROST
LIKELY OVERNIGHT INTO EARLY THU MORNING. FROST AND FREEZE HEADLINES
MAY EVENTUALLY BE NEEDED OVERNIGHT WED NIGHT. SURFACE CANADIAN RIDGE
ONLY SLOWLY SHIFTS EAST OF IL BY FRIDAY MORNING SO THINK FROST WILL
AGAIN BE POSSIBLE OVER EASTERN IL OVERNIGHT THU NIGHT INTO EARLY FRI
MORNING WITH LOWS IN THE MID 30S AFTER HIGHS REACH UPPER 50S AND
LOWER 60S ON THURSDAY (MILDEST IN SW CWA).
12Z MEDIUM RANGE MODELS EJECT A SURFACE AND CUTOFF LOW FROM CO TO MO
BY SATURDAY MORNING. THINK MOST AREAS WILL STILL STAY DRY ON FRIDAY
AND ONLY HAVE SLIGHT CHANCES OF LIGHT SHOWERS FAR WESTERN/SW AREAS
LATER FRIDAY AFTERNOON WITH CLOUDS INCREASING DURING THE DAY FRIDAY
FROM THE WSW. HIGHS FRIDAY IN THE LOWER 60S ACROSS MOST OF THE
REGION. HAVE LIKELY CHANCES OF SHOWERS FRIDAY NIGHT INTO SATURDAY
WITH HIGHEST CHANCES SOUTHERN AREAS WHERE ISOLATED THUNDERSTORMS
POSSIBLE. JUST SLIGHT CHANCES OF LIGHT RAIN SHOWERS IN SOUTHEAST IL
SATURDAY EVENING THEN DRY REST OF THE WEEKEND. COOLER HIGHS SAT IN
THE 50S WHILE MORE SUNSHINE SUNDAY RETURNS HIGHS BACK INTO THE LOWER
60S.
THE 12Z EXTENDED FORECAST MODELS HAVE ANOTHER WEATHER SYSTEM
EJECTING OUT OF THE SOUTHERN PLAINS ON MONDAY INTO TUESDAY. THIS
BRINGS NEXT CHANCE OF RAIN SHOWERS AND RAINFALL AMOUNTS FAIRLY LIGHT
DUE TO GULF OF MEXICO BEING CUTOFF.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 602 PM CDT TUE APR 21 2015
VFR CONDITIONS ARE EXPECTED THRU THIS TAF PERIOD. A WEAK COLD
FRONT LOCATED OVER PARTS OF EAST CENTRAL IOWA WILL TRACK ACROSS
THE AREA TONIGHT BRINGING SOME SCATTERED LIGHT SHOWERS WITH IT
WITH BKN-OVC CIGS BETWEEN 3500 AND 4500 FEET. LATEST RAP FORECAST
SOUNDINGS BACKING OFF A BIT WITH THE PRECIP OVER THE PAST FEW
RUNS BUT STILL HOLDING WITH A BRIEF PERIOD OF LOW VFR CIGS ALONG
THE COLD FRONT. THE GUSTY WEST TO NORTHWEST WINDS WILL DIMINISH
RATHER QUICKLY AFTER SUNSET WITH A LIGHT WEST TO NORTHWEST WIND
EXPECTED OVERNIGHT WITH SPEEDS OF 7 TO 12 KTS. THOSE WINDS WILL
BECOME NORTHWEST AND INCREASE IN SPEED ON WEDNESDAY TO BETWEEN
15 AND 25 KTS WITH A FEW GUSTS UP TO 30 KTS AT TIMES BEFORE
DIMINISHING QUICKLY TOWARDS SUNSET.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-037-038-
043>046.
&&
$$
SHORT TERM...GEELHART
LONG TERM...07
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1229 PM CDT MON APR 20 2015
.UPDATE...
ISSUED AT 1022 AM CDT MON APR 20 2015
LITTLE CHANGE NEEDED TO THE PREVIOUS FORECAST. SHOWERS HAVE
LARGELY EXITED THE AREA...AND EARLIER CLEARING TREND ACROSS WEST
CENTRAL ILLINOIS HAS BEEN FILLING IN WITH DIURNAL CLOUDS. HIGH-RES
MODEL GUIDANCE SHOWING POTENTIAL FOR SOME LIGHT REDEVELOPMENT
THROUGH THE DAY...WHICH CURRENTLY IS SEEN IN CENTRAL IOWA MOVING
SOUTHEAST. WITH STRONG COLD AIR ADVECTION AND NORTHWEST WINDS
GUSTING 30-40 MPH...HAVE LOWERED AFTERNOON TEMPERATURES BY A
COUPLE DEGREES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT MON APR 20 2015
07Z/2AM WATER VAPOR IMAGERY SHOWS LONG-WAVE TROUGH AXIS EXTENDING
FROM MINNESOTA TO NORTHERN TEXAS, WITH VIGOROUS SHORT-WAVE NOTED ON
ITS EAST SIDE OVER SOUTHEAST MISSOURI. WITH MAIN WAVE STILL TO THE
WEST, SCATTERED SHOWERS ARE ONGOING ACROSS CENTRAL ILLINOIS EARLY
THIS MORNING. AS SOUTHEAST MISSOURI WAVE TRACKS INTO THE OHIO RIVER
VALLEY, THINK AREAL COVERAGE OF SHOWERS WILL DIMINISH AFTER SUNRISE,
WITH LITTLE OR NO PRECIP OCCURRING FOR THE BALANCE OF THE MORNING.
DESPITE LOW-LEVEL DRYING IN THE WAKE OF THIS FEATURE, SYNOPTIC-SCALE
CYCLONIC FLOW ALOFT WILL LEAD TO STEEP LAPSE RATES AND PERHAPS A FEW
SHOWERS FROM LATE MORNING INTO THE AFTERNOON. MOST MODEL GUIDANCE
REMAINS DRY: HOWEVER, BOTH THE HRRR AND 4KM WRF-NMM SUGGEST AT LEAST
ISOLATED SHOWERS AS THE ATMOSPHERE DESTABILIZES. WILL CARRY SLIGHT
CHANCE POPS ACROSS THE BOARD TO COVER THIS POSSIBILITY. COLD FRONT
CURRENTLY APPROACHING THE I-55 CORRIDOR WILL SWEEP EASTWARD THIS
MORNING AND EXIT INTO INDIANA BY MIDDAY. STRONG/GUSTY WINDS WILL
DEVELOP BEHIND THE FRONT AS PRESSURE GRADIENT TIGHTENS. LATEST OBS
ARE ALREADY SHOWING GUSTS IN THE 25 TO 30MPH RANGE AND THINK MIXING
OF HIGHER MOMENTUM AIR ALOFT WILL RESULT IN GUSTS OF 30 TO 35MPH
DURING THE DAY. HIGH TEMPERATURES WILL BE IN THE UPPER 50S AND
LOWER 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 AM CDT MON APR 20 2015
A COOL AND MOSTLY DRY WEEK IS ON TAP ACROSS CENTRAL ILLINOIS, WITH
THE NEXT SIGNIFICANT CHANCE FOR RAIN LIKELY HOLDING OFF UNTIL NEXT
WEEKEND. A DEEP UPPER LOW OVER THE GREAT LAKES WILL BE THE DOMINANT
WEATHER FEATURE EARLY IN THE PERIOD, KEEPING THE MIDWEST LOCKED IN A
NORTHWESTERLY FLOW PATTERN. THANKS TO A TIGHTENING PRESSURE
GRADIENT AHEAD OF AN APPROACHING COLD FRONT, STRONG WESTERLY WINDS
WILL ONCE AGAIN DEVELOP ON TUESDAY. NUMERIC GUIDANCE AND FORECAST
SOUNDINGS BOTH SUGGEST GUSTS REACHING 30 TO 35MPH AT TIMES. THE
FRONT WILL PASS THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY
MORNING: HOWEVER, DEEP-LAYER MOISTURE WILL BE LACKING, SO PRECIP
CHANCES WILL REMAIN NEGLIGIBLE. WILL ONLY CARRY LOW CHANCE POPS
ACROSS THE SOUTHERN KILX CWA AS THE FRONT PASSES. AN EVEN COOLER
AIRMASS WILL ARRIVE FOR THE MIDDLE AND END OF THE WEEK BEHIND THE
DEPARTING FRONT, WITH HIGHS DROPPING INTO THE UPPER 50S/LOWER 60S
FOR WEDNESDAY THROUGH FRIDAY. OVERNIGHT LOWS WILL DIP INTO THE 30S,
WITH THE BEST POTENTIAL FOR FROST LIKELY SETTING UP FOR WEDNESDAY
NIGHT AND THURSDAY NIGHT AS SKIES REMAIN CLEAR AND WINDS DIMINISH.
FURTHER OUT, MAJOR MODEL DISCREPANCIES HAVE DEVELOPED CONCERNING THE
NEXT POTENTIAL SYSTEM FOR THE END OF THE WEEK. THE 00Z APR 20 GFS
HAS MADE A MAJOR SHIFT FROM ITS PREVIOUS RUNS AND NOW SHOWS RAIN
SPREADING INTO CENTRAL ILLINOIS FROM AN APPROACHING UPPER LOW AS
EARLY AS FRIDAY. MEANWHILE, BOTH THE ECMWF AND GEM ARE MUCH SLOWER,
WITH RAIN NOT ARRIVING UNTIL LATE FRIDAY NIGHT INTO SATURDAY. GIVEN
INITIAL PRESENCE OF A STRONG RIDGE AXIS ACROSS THE MIDWEST, THINK
THE RAPID PROGRESSION OF RAIN INTO THE DRY AIRMASS SEEMS SUSPECT.
IN ADDITION, THE SLOWER ECMWF/GEM HAVE MAINTAINED GOOD CONSISTENCY
WITH THEIR EARLIER RUNS. AS A RESULT, HAVE REJECTED THE GFS IN
FAVOR OF THE ECMWF/GEM CONSENSUS FOR THE END OF THE WEEK. HAVE
THEREFORE KEPT FRIDAY DRY, THEN HAVE INTRODUCED POPS MAINLY ACROSS
THE CENTRAL AND SOUTHERN CWA FRIDAY NIGHT INTO SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1229 PM CDT MON APR 20 2015
WEST WINDS WILL REMAIN GUSTY THROUGH THE AFTERNOON WITH SOME
PERIODS OVER 30 KNOTS. WINDS WILL SUBSIDE THIS EVENING...ALTHOUGH
SUSTAINED SPEEDS REMAIN 10 KNOTS OR SO MUCH OF THE NIGHT. SPEEDS
EXPECTED TO PICK UP AGAIN EARLY TUESDAY...WITH THE GFS THE MOST
AGGRESSIVE WITH GUSTS OVER 30 KNOTS AS EARLY AS 15Z. DID NOT GO
QUITE THAT HIGH YET...BUT HAVE INCLUDED GUSTS 25-28 KNOTS AT ALL
SITES TUESDAY MORNING.
SOME LINGERING MVFR CONDITIONS CONTINUING FOR ANOTHER HOUR OR TWO
AT KCMI...BUT GENERAL TREND WILL BE FOR CEILINGS 3500-4500 FEET
ACROSS CENTRAL ILLINOIS THIS AFTERNOON. CLOUDS ARE DIURNAL IN
NATURE AND SHOULD DISSIPATE EARLY EVENING WITH LOSS OF DAYTIME
HEATING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1025 AM CDT MON APR 20 2015
.UPDATE...
ISSUED AT 1022 AM CDT MON APR 20 2015
LITTLE CHANGE NEEDED TO THE PREVIOUS FORECAST. SHOWERS HAVE
LARGELY EXITED THE AREA...AND EARLIER CLEARING TREND ACROSS WEST
CENTRAL ILLINOIS HAS BEEN FILLING IN WITH DIURNAL CLOUDS. HIGH-RES
MODEL GUIDANCE SHOWING POTENTIAL FOR SOME LIGHT REDEVELOPMENT
THROUGH THE DAY...WHICH CURRENTLY IS SEEN IN CENTRAL IOWA MOVING
SOUTHEAST. WITH STRONG COLD AIR ADVECTION AND NORTHWEST WINDS
GUSTING 30-40 MPH...HAVE LOWERED AFTERNOON TEMPERATURES BY A
COUPLE DEGREES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT MON APR 20 2015
07Z/2AM WATER VAPOR IMAGERY SHOWS LONG-WAVE TROUGH AXIS EXTENDING
FROM MINNESOTA TO NORTHERN TEXAS, WITH VIGOROUS SHORT-WAVE NOTED ON
ITS EAST SIDE OVER SOUTHEAST MISSOURI. WITH MAIN WAVE STILL TO THE
WEST, SCATTERED SHOWERS ARE ONGOING ACROSS CENTRAL ILLINOIS EARLY
THIS MORNING. AS SOUTHEAST MISSOURI WAVE TRACKS INTO THE OHIO RIVER
VALLEY, THINK AREAL COVERAGE OF SHOWERS WILL DIMINISH AFTER SUNRISE,
WITH LITTLE OR NO PRECIP OCCURRING FOR THE BALANCE OF THE MORNING.
DESPITE LOW-LEVEL DRYING IN THE WAKE OF THIS FEATURE, SYNOPTIC-SCALE
CYCLONIC FLOW ALOFT WILL LEAD TO STEEP LAPSE RATES AND PERHAPS A FEW
SHOWERS FROM LATE MORNING INTO THE AFTERNOON. MOST MODEL GUIDANCE
REMAINS DRY: HOWEVER, BOTH THE HRRR AND 4KM WRF-NMM SUGGEST AT LEAST
ISOLATED SHOWERS AS THE ATMOSPHERE DESTABILIZES. WILL CARRY SLIGHT
CHANCE POPS ACROSS THE BOARD TO COVER THIS POSSIBILITY. COLD FRONT
CURRENTLY APPROACHING THE I-55 CORRIDOR WILL SWEEP EASTWARD THIS
MORNING AND EXIT INTO INDIANA BY MIDDAY. STRONG/GUSTY WINDS WILL
DEVELOP BEHIND THE FRONT AS PRESSURE GRADIENT TIGHTENS. LATEST OBS
ARE ALREADY SHOWING GUSTS IN THE 25 TO 30MPH RANGE AND THINK MIXING
OF HIGHER MOMENTUM AIR ALOFT WILL RESULT IN GUSTS OF 30 TO 35MPH
DURING THE DAY. HIGH TEMPERATURES WILL BE IN THE UPPER 50S AND
LOWER 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 AM CDT MON APR 20 2015
A COOL AND MOSTLY DRY WEEK IS ON TAP ACROSS CENTRAL ILLINOIS, WITH
THE NEXT SIGNIFICANT CHANCE FOR RAIN LIKELY HOLDING OFF UNTIL NEXT
WEEKEND. A DEEP UPPER LOW OVER THE GREAT LAKES WILL BE THE DOMINANT
WEATHER FEATURE EARLY IN THE PERIOD, KEEPING THE MIDWEST LOCKED IN A
NORTHWESTERLY FLOW PATTERN. THANKS TO A TIGHTENING PRESSURE
GRADIENT AHEAD OF AN APPROACHING COLD FRONT, STRONG WESTERLY WINDS
WILL ONCE AGAIN DEVELOP ON TUESDAY. NUMERIC GUIDANCE AND FORECAST
SOUNDINGS BOTH SUGGEST GUSTS REACHING 30 TO 35MPH AT TIMES. THE
FRONT WILL PASS THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY
MORNING: HOWEVER, DEEP-LAYER MOISTURE WILL BE LACKING, SO PRECIP
CHANCES WILL REMAIN NEGLIGIBLE. WILL ONLY CARRY LOW CHANCE POPS
ACROSS THE SOUTHERN KILX CWA AS THE FRONT PASSES. AN EVEN COOLER
AIRMASS WILL ARRIVE FOR THE MIDDLE AND END OF THE WEEK BEHIND THE
DEPARTING FRONT, WITH HIGHS DROPPING INTO THE UPPER 50S/LOWER 60S
FOR WEDNESDAY THROUGH FRIDAY. OVERNIGHT LOWS WILL DIP INTO THE 30S,
WITH THE BEST POTENTIAL FOR FROST LIKELY SETTING UP FOR WEDNESDAY
NIGHT AND THURSDAY NIGHT AS SKIES REMAIN CLEAR AND WINDS DIMINISH.
FURTHER OUT, MAJOR MODEL DISCREPANCIES HAVE DEVELOPED CONCERNING THE
NEXT POTENTIAL SYSTEM FOR THE END OF THE WEEK. THE 00Z APR 20 GFS
HAS MADE A MAJOR SHIFT FROM ITS PREVIOUS RUNS AND NOW SHOWS RAIN
SPREADING INTO CENTRAL ILLINOIS FROM AN APPROACHING UPPER LOW AS
EARLY AS FRIDAY. MEANWHILE, BOTH THE ECMWF AND GEM ARE MUCH SLOWER,
WITH RAIN NOT ARRIVING UNTIL LATE FRIDAY NIGHT INTO SATURDAY. GIVEN
INITIAL PRESENCE OF A STRONG RIDGE AXIS ACROSS THE MIDWEST, THINK
THE RAPID PROGRESSION OF RAIN INTO THE DRY AIRMASS SEEMS SUSPECT.
IN ADDITION, THE SLOWER ECMWF/GEM HAVE MAINTAINED GOOD CONSISTENCY
WITH THEIR EARLIER RUNS. AS A RESULT, HAVE REJECTED THE GFS IN
FAVOR OF THE ECMWF/GEM CONSENSUS FOR THE END OF THE WEEK. HAVE
THEREFORE KEPT FRIDAY DRY, THEN HAVE INTRODUCED POPS MAINLY ACROSS
THE CENTRAL AND SOUTHERN CWA FRIDAY NIGHT INTO SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 630 AM CDT MON APR 20 2015
CLOUDS OVER THE TAF SITES ARE AT MVFR LEVELS, EXCEPT FOR BMI THAT
IS AT IFR RIGHT NOW. BELIEVE THAT BMI WILL IMPROVE TO LOWER MVFR
SOON, BUT STILL HAVE A TEMPO GROUP FOR A COUPLE HOURS TO COVER.
MVFR CIGS WILL CONTINUE THIS MORNING. SATELLITE TRENDS SHOW
CLEARING TO THE WEST OF SPI, BUT BELIEVE ONCE SUN GETS LITTLE
HIGHER, CU/SC WILL DEVELOP QUICKLY, KEEPING CLOUDS OVER SPI LATE
THIS MORNING. HIRES MODELS CONTINUE TO SHOW SCATTERED SHOWERS
DEVELOPING TO THE WEST AND MOVING INTO THE AREA. AGREE WITH THIS
FORECAST SO HAVE INCLUDED VCSH AT ALL TAF SITES FOR THIS
AFTERNOON. CLOUDS AND PCPN WILL BE DIURNAL, SO SKIES SHOULD CLEAR
JUST AFTER SUNSET. BIGGEST ISSUE WILL BE THE GUSTY WEST WINDS.
WILL HAVE GUSTS TO 25-28KTS THIS MORNING, BUT THEN INCREASE TO
30KTS FOR THIS AFTERNOON. WINDS WILL DIMINISH THIS EVENING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
630 AM CDT MON APR 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT MON APR 20 2015
07Z/2AM WATER VAPOR IMAGERY SHOWS LONG-WAVE TROUGH AXIS EXTENDING
FROM MINNESOTA TO NORTHERN TEXAS, WITH VIGOROUS SHORT-WAVE NOTED ON
ITS EAST SIDE OVER SOUTHEAST MISSOURI. WITH MAIN WAVE STILL TO THE
WEST, SCATTERED SHOWERS ARE ONGOING ACROSS CENTRAL ILLINOIS EARLY
THIS MORNING. AS SOUTHEAST MISSOURI WAVE TRACKS INTO THE OHIO RIVER
VALLEY, THINK AREAL COVERAGE OF SHOWERS WILL DIMINISH AFTER SUNRISE,
WITH LITTLE OR NO PRECIP OCCURRING FOR THE BALANCE OF THE MORNING.
DESPITE LOW-LEVEL DRYING IN THE WAKE OF THIS FEATURE, SYNOPTIC-SCALE
CYCLONIC FLOW ALOFT WILL LEAD TO STEEP LAPSE RATES AND PERHAPS A FEW
SHOWERS FROM LATE MORNING INTO THE AFTERNOON. MOST MODEL GUIDANCE
REMAINS DRY: HOWEVER, BOTH THE HRRR AND 4KM WRF-NMM SUGGEST AT LEAST
ISOLATED SHOWERS AS THE ATMOSPHERE DESTABILIZES. WILL CARRY SLIGHT
CHANCE POPS ACROSS THE BOARD TO COVER THIS POSSIBILITY. COLD FRONT
CURRENTLY APPROACHING THE I-55 CORRIDOR WILL SWEEP EASTWARD THIS
MORNING AND EXIT INTO INDIANA BY MIDDAY. STRONG/GUSTY WINDS WILL
DEVELOP BEHIND THE FRONT AS PRESSURE GRADIENT TIGHTENS. LATEST OBS
ARE ALREADY SHOWING GUSTS IN THE 25 TO 30MPH RANGE AND THINK MIXING
OF HIGHER MOMENTUM AIR ALOFT WILL RESULT IN GUSTS OF 30 TO 35MPH
DURING THE DAY. HIGH TEMPERATURES WILL BE IN THE UPPER 50S AND
LOWER 60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 AM CDT MON APR 20 2015
A COOL AND MOSTLY DRY WEEK IS ON TAP ACROSS CENTRAL ILLINOIS, WITH
THE NEXT SIGNIFICANT CHANCE FOR RAIN LIKELY HOLDING OFF UNTIL NEXT
WEEKEND. A DEEP UPPER LOW OVER THE GREAT LAKES WILL BE THE DOMINANT
WEATHER FEATURE EARLY IN THE PERIOD, KEEPING THE MIDWEST LOCKED IN A
NORTHWESTERLY FLOW PATTERN. THANKS TO A TIGHTENING PRESSURE
GRADIENT AHEAD OF AN APPROACHING COLD FRONT, STRONG WESTERLY WINDS
WILL ONCE AGAIN DEVELOP ON TUESDAY. NUMERIC GUIDANCE AND FORECAST
SOUNDINGS BOTH SUGGEST GUSTS REACHING 30 TO 35MPH AT TIMES. THE
FRONT WILL PASS THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY
MORNING: HOWEVER, DEEP-LAYER MOISTURE WILL BE LACKING, SO PRECIP
CHANCES WILL REMAIN NEGLIGIBLE. WILL ONLY CARRY LOW CHANCE POPS
ACROSS THE SOUTHERN KILX CWA AS THE FRONT PASSES. AN EVEN COOLER
AIRMASS WILL ARRIVE FOR THE MIDDLE AND END OF THE WEEK BEHIND THE
DEPARTING FRONT, WITH HIGHS DROPPING INTO THE UPPER 50S/LOWER 60S
FOR WEDNESDAY THROUGH FRIDAY. OVERNIGHT LOWS WILL DIP INTO THE 30S,
WITH THE BEST POTENTIAL FOR FROST LIKELY SETTING UP FOR WEDNESDAY
NIGHT AND THURSDAY NIGHT AS SKIES REMAIN CLEAR AND WINDS DIMINISH.
FURTHER OUT, MAJOR MODEL DISCREPANCIES HAVE DEVELOPED CONCERNING THE
NEXT POTENTIAL SYSTEM FOR THE END OF THE WEEK. THE 00Z APR 20 GFS
HAS MADE A MAJOR SHIFT FROM ITS PREVIOUS RUNS AND NOW SHOWS RAIN
SPREADING INTO CENTRAL ILLINOIS FROM AN APPROACHING UPPER LOW AS
EARLY AS FRIDAY. MEANWHILE, BOTH THE ECMWF AND GEM ARE MUCH SLOWER,
WITH RAIN NOT ARRIVING UNTIL LATE FRIDAY NIGHT INTO SATURDAY. GIVEN
INITIAL PRESENCE OF A STRONG RIDGE AXIS ACROSS THE MIDWEST, THINK
THE RAPID PROGRESSION OF RAIN INTO THE DRY AIRMASS SEEMS SUSPECT.
IN ADDITION, THE SLOWER ECMWF/GEM HAVE MAINTAINED GOOD CONSISTENCY
WITH THEIR EARLIER RUNS. AS A RESULT, HAVE REJECTED THE GFS IN
FAVOR OF THE ECMWF/GEM CONSENSUS FOR THE END OF THE WEEK. HAVE
THEREFORE KEPT FRIDAY DRY, THEN HAVE INTRODUCED POPS MAINLY ACROSS
THE CENTRAL AND SOUTHERN CWA FRIDAY NIGHT INTO SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 630 AM CDT MON APR 20 2015
CLOUDS OVER THE TAF SITES ARE AT MVFR LEVELS, EXCEPT FOR BMI THAT
IS AT IFR RIGHT NOW. BELIEVE THAT BMI WILL IMPROVE TO LOWER MVFR
SOON, BUT STILL HAVE A TEMPO GROUP FOR A COUPLE HOURS TO COVER.
MVFR CIGS WILL CONTINUE THIS MORNING. SATELLITE TRENDS SHOW
CLEARING TO THE WEST OF SPI, BUT BELIEVE ONCE SUN GETS LITTLE
HIGHER, CU/SC WILL DEVELOP QUICKLY, KEEPING CLOUDS OVER SPI LATE
THIS MORNING. HIRES MODELS CONTINUE TO SHOW SCATTERED SHOWERS
DEVELOPING TO THE WEST AND MOVING INTO THE AREA. AGREE WITH THIS
FORECAST SO HAVE INCLUDED VCSH AT ALL TAF SITES FOR THIS
AFTERNOON. CLOUDS AND PCPN WILL BE DIURNAL, SO SKIES SHOULD CLEAR
JUST AFTER SUNSET. BIGGEST ISSUE WILL BE THE GUSTY WEST WINDS.
WILL HAVE GUSTS TO 25-28KTS THIS MORNING, BUT THEN INCREASE TO
30KTS FOR THIS AFTERNOON. WINDS WILL DIMINISH THIS EVENING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
313 AM CDT MON APR 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT MON APR 20 2015
07Z/2AM WATER VAPOR IMAGERY SHOWS LONG-WAVE TROUGH AXIS EXTENDING
FROM MINNESOTA TO NORTHERN TEXAS, WITH VIGOROUS SHORT-WAVE NOTED ON
ITS EAST SIDE OVER SOUTHEAST MISSOURI. WITH MAIN WAVE STILL TO THE
WEST, SCATTERED SHOWERS ARE ONGOING ACROSS CENTRAL ILLINOIS EARLY
THIS MORNING. AS SOUTHEAST MISSOURI WAVE TRACKS INTO THE OHIO RIVER
VALLEY, THINK AREAL COVERAGE OF SHOWERS WILL DIMINISH AFTER SUNRISE,
WITH LITTLE OR NO PRECIP OCCURRING FOR THE BALANCE OF THE MORNING.
DESPITE LOW-LEVEL DRYING IN THE WAKE OF THIS FEATURE, SYNOPTIC-SCALE
CYCLONIC FLOW ALOFT WILL LEAD TO STEEP LAPSE RATES AND PERHAPS A FEW
SHOWERS FROM LATE MORNING INTO THE AFTERNOON. MOST MODEL GUIDANCE
REMAINS DRY: HOWEVER, BOTH THE HRRR AND 4KM WRF-NMM SUGGEST AT LEAST
ISOLATED SHOWERS AS THE ATMOSPHERE DESTABILIZES. WILL CARRY SLIGHT
CHANCE POPS ACROSS THE BOARD TO COVER THIS POSSIBILITY. COLD FRONT
CURRENTLY APPROACHING THE I-55 CORRIDOR WILL SWEEP EASTWARD THIS
MORNING AND EXIT INTO INDIANA BY MIDDAY. STRONG/GUSTY WINDS WILL
DEVELOP BEHIND THE FRONT AS PRESSURE GRADIENT TIGHTENS. LATEST OBS
ARE ALREADY SHOWING GUSTS IN THE 25 TO 30MPH RANGE AND THINK MIXING
OF HIGHER MOMENTUM AIR ALOFT WILL RESULT IN GUSTS OF 30 TO 35MPH
DURING THE DAY. HIGH TEMPERATURES WILL BE IN THE UPPER 50S AND
LOWER 60S.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 AM CDT MON APR 20 2015
A COOL AND MOSTLY DRY WEEK IS ON TAP ACROSS CENTRAL ILLINOIS, WITH
THE NEXT SIGNIFICANT CHANCE FOR RAIN LIKELY HOLDING OFF UNTIL NEXT
WEEKEND. A DEEP UPPER LOW OVER THE GREAT LAKES WILL BE THE DOMINANT
WEATHER FEATURE EARLY IN THE PERIOD, KEEPING THE MIDWEST LOCKED IN A
NORTHWESTERLY FLOW PATTERN. THANKS TO A TIGHTENING PRESSURE
GRADIENT AHEAD OF AN APPROACHING COLD FRONT, STRONG WESTERLY WINDS
WILL ONCE AGAIN DEVELOP ON TUESDAY. NUMERIC GUIDANCE AND FORECAST
SOUNDINGS BOTH SUGGEST GUSTS REACHING 30 TO 35MPH AT TIMES. THE
FRONT WILL PASS THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY
MORNING: HOWEVER, DEEP-LAYER MOISTURE WILL BE LACKING, SO PRECIP
CHANCES WILL REMAIN NEGLIGIBLE. WILL ONLY CARRY LOW CHANCE POPS
ACROSS THE SOUTHERN KILX CWA AS THE FRONT PASSES. AN EVEN COOLER
AIRMASS WILL ARRIVE FOR THE MIDDLE AND END OF THE WEEK BEHIND THE
DEPARTING FRONT, WITH HIGHS DROPPING INTO THE UPPER 50S/LOWER 60S
FOR WEDNESDAY THROUGH FRIDAY. OVERNIGHT LOWS WILL DIP INTO THE 30S,
WITH THE BEST POTENTIAL FOR FROST LIKELY SETTING UP FOR WEDNESDAY
NIGHT AND THURSDAY NIGHT AS SKIES REMAIN CLEAR AND WINDS DIMINISH.
FURTHER OUT, MAJOR MODEL DISCREPANCIES HAVE DEVELOPED CONCERNING THE
NEXT POTENTIAL SYSTEM FOR THE END OF THE WEEK. THE 00Z APR 20 GFS
HAS MADE A MAJOR SHIFT FROM ITS PREVIOUS RUNS AND NOW SHOWS RAIN
SPREADING INTO CENTRAL ILLINOIS FROM AN APPROACHING UPPER LOW AS
EARLY AS FRIDAY. MEANWHILE, BOTH THE ECMWF AND GEM ARE MUCH SLOWER,
WITH RAIN NOT ARRIVING UNTIL LATE FRIDAY NIGHT INTO SATURDAY. GIVEN
INITIAL PRESENCE OF A STRONG RIDGE AXIS ACROSS THE MIDWEST, THINK
THE RAPID PROGRESSION OF RAIN INTO THE DRY AIRMASS SEEMS SUSPECT.
IN ADDITION, THE SLOWER ECMWF/GEM HAVE MAINTAINED GOOD CONSISTENCY
WITH THEIR EARLIER RUNS. AS A RESULT, HAVE REJECTED THE GFS IN
FAVOR OF THE ECMWF/GEM CONSENSUS FOR THE END OF THE WEEK. HAVE
THEREFORE KEPT FRIDAY DRY, THEN HAVE INTRODUCED POPS MAINLY ACROSS
THE CENTRAL AND SOUTHERN CWA FRIDAY NIGHT INTO SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1146 PM CDT SUN APR 19 2015
COLD FRONT FROM AROUND KGBG-KIJX THIS EVENING WILL CROSS CENTRAL
IL TERMINALS THROUGH 10Z CAUSING A FEW SHOWERS AND BRINGING AN
INCREASE IN WESTERLY WINDS. A MIX OF IFR/LIFR CEILINGS AND MAINLY
MVFR VSBYS IN BR WILL GRADUALLY IMPROVE AFTER FRONTAL
PASSAGE...WITH GENERALLY VFR CONDITIONS BY AROUND 14Z. WINDS
INCREASING TO W 15-20 KTS WITH GUSTS UP TO 30 KTS LATE MORNING
THROUGH AFTERNOON. WINDS AND GUSTS DECREASING AFTER 00Z TUESDAY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
104 AM CDT MON APR 20 2015
.UPDATE...809 PM CDT
STEADY RAIN WILL CONTINUE MUCH OF THE EVENING ACROSS NORTHERN
ILLINOIS. MID-LEVEL DRY SLOT WILL PIVOT ACROSS EAST-CENTRAL
ILLINOIS AND NORTHWEST INDIANA THIS EVENING WITH RAIN TAPERING TO
A LIGHT DRIZZLE FOR THESE AREAS...BEFORE SHOWERS SPREAD BACK IN
FROM THE WEST OVERNIGHT. ADDED PATCHY FOG TO THE GRIDS THIS
EVENING AND TONIGHT AS SATURATED TO NEAR SATURATED CONDITIONS ARE
IN PLACE THIS EVENING. SUSPECT VISIBILITY WILL BEGIN TO IMPROVE AS
WEST WINDS INCREASE AFTER MIDNIGHT TONIGHT.
BMD
&&
.SHORT TERM...
319 PM CDT
THROUGH MONDAY NIGHT...
AFTER ANOTHER WARM EARLY AFTERNOON ACROSS MUCH OF THE REGION RAIN IS
BEGINNING TO SPREAD NORTHWARD ACROSS SOUTHERN SECTIONS OF THE CHICAGO
METRO AREA AS OF THIS WRITING. THIS ACTIVITY WILL CONTINUE TO
OVERSPREAD THE REGION THROUGH THE AFTERNOON AND EVENING...WITH
TEMPERATURES LIKELY TO DROP BACK INTO THE UPPER 50S AND LOW 60S IN
THE RAIN.
THE MID-LEVEL DISTURBANCE...AND THE ASSOCIATED SURFACE SYSTEM WILL
QUICKLY SHIFT NORTHWARD OVER LOWER MICHIGAN OVERNIGHT...AND IT
APPEARS THAT THE RAIN WILL BECOME MORE SHOWERY AND INTERMITTENT OR
POSSIBLY JUST SOME DRIZZLE LATER THIS EVENING AND INTO THE EARLY
MORNING ACROSS MUCH OF THE AREA AS THIS INITIAL MID LEVEL
DISTURBANCE SHIFTS NORTH OF THE AREA AND SOME DRIER MID LEVEL AIR
SHIFTS OVER THE SOUTHEASTERN HALF OF MY AREA. SOME ADDITIONAL RAIN
SHOWERS ARE POSSIBLE AGAIN EARLY MONDAY WITHIN A REGION OF MID LEVEL
DEFORMATION AND RAP AROUND MOISTURE ASSOCIATED WITH THE DEEPENING
LOWER AND MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION AND
SOUTHERN CANADA.
CONDITIONS SHOULD DRY OUT MONDAY AFTERNOON...WITH ONLY A SMALL
CHANCE OF AN ADDITIONAL SHOWER DEVELOPING AS COLDER AIR ALOFT
STEEPENS THE LOWER LEVEL LAPSE RATES. THE MAIN STORY DURING THE
AFTERNOON WILL BE THE WINDS. WINDS ARE EXPECTED TO INCREASE OUT OF
THE WEST-NORTHWEST DURING THE DAY AS STOUT SURFACE PRESSURE
GRADIENT SETS UP OVER THE REGION AS THE SURFACE LOW DEEPENS TO
AROUND 985 MB ACROSS ONTARIO MONDAY AFTERNOON. MODEL SOUNDINGS
SUGGEST GOOD AFTERNOON MIXING TO AROUND 850 MB SHOULD ALLOW FOR
GUSTS OF AROUND 30 KT AT TIMES...ESPECIALLY DURING THE AFTERNOON.
THESE WIND GUSTS SHOULD ABATE MONDAY EVENING...BUT STRONG WINDS
LOOK TO DEVELOP AGAIN ON TUESDAY. SEE LONG TERM DISCUSSION FOR
MORE INFO ON TUESDAY`S WINDS.
KJB
&&
.LONG TERM...
319 PM CDT
TUESDAY THROUGH SUNDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH BELOW NORMAL TEMPS
THROUGH THE FORECAST.
LARGE UPPER LEVEL CENTER WILL BE CENTERED ACROSS THE REGION AT THE
START OF THE PERIOD...AND REMAIN SITUATED THROUGH MUCH OF THE WORK
WEEK AS IT SLOWLY MOVES EAST. SEVERAL VORT LOBES ARE ANTICIPATED TO
WRAP AROUND THIS UPPER LEVEL LOW ON TUESDAY AND WITH STEEPENING
LAPSE RATES...EXPECT SKY COVER TO INCREASE THROUGH THE DAY WHILE
SCATTERED SHOWERS BECOME POSSIBLE...ESPECIALLY ACROSS NORTHERN
ILLINOIS. AS THIS OCCURS...LIKELY DEEP MIXING WITH STRONG FLOW ALOFT
WILL ALLOW FOR ANOTHER WINDY DAY. GUIDANCE IS SUGGESTING THAT
ADVISORY CONDITIONS COULD BE REACHED IN THE AFTERNOON...AND WILL
NEED TO CONTINUE MONITORING THIS POTENTIAL. ANY REMAINING PRECIP AND
CLOUD COVER SHOULD EXIT THE AREA TUESDAY NIGHT WITH DRY CONDITIONS
EXPECTED. SOME GUIDANCE DEVELOPS A SWATH OF PRECIP OVER THE CWA LATE
IN THE NIGHT INTO EARLY WEDNESDAY. HOWEVER...A MORE LIKELY SCENARIO
AT THIS TIME WOULD BE FOR DRY CONDITIONS AND SO HAVE LEFT OUT ANY
POPS AT THIS TIME. ONGOING CAA WILL MAKE FOR CHILLY CONDITIONS
TUESDAY NIGHT...WITH LOW TEMPS IN THE 30S. IF PRECIP WERE TO OCCUR
DURING THIS PERIOD...THESE COLDER CONDITIONS COULD SUPPORT THE
POTENTIAL FOR AT LEAST A RAIN SNOW MIX ACROSS NORTHERN ILLINOIS.
EXPECT DRY CONDITIONS WITH BELOW NORMAL TEMPS THROUGH THE REST OF
THE FORECAST PERIOD...WITH FORECAST HIGHS IN THE 50S. COLD NIGHT
TIME LOWS IN THE 30S COULD BECOME AN ISSUE LATE IN THE WORK WEEK AS
HIGH PRESSURE IS ANTICIPATED TO MOVE OVERHEAD...WITH LIGHTER WINDS
AND THE COLD TEMPS POSSIBLY CREATING A SETUP FOR FROST.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WINDS BACKING NORTHWEST LATE THIS EVENING.
* A PERIOD OF SHOWERS MONDAY MORNING.
* LIFR CIGS LASTING INTO OVERNIGHT WITH SLOW IMPROVEMENT DURING
THE DAYBREAK TIME.
* MVFR VISIBILITY THROUGH THE EARLY MORNING HOURS.
* GUSTY WEST WINDS DEVELOPING MONDAY MORNING WITH MAX GUSTS ARND
30 KT LATE MONDAY MORNING AND AFTERNOON.
KMD
//DISCUSSION...UPDATED 06Z...
IFR/LIFR CIGS ARE COMMON ACROSS THE AREA ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW. VSBYS HAVE NOT DIPPED TOO FAR...HOLDING
AT 3-4SM AND LARGELY BETTER THAN THAT IN MOST AREAS THE LOW
CONTINUES NORTHEAST...EXPECT WINDS TO VEER TO SW. NOT EXPECTING
VSBYS TO DROP MUCH FURTHER AS WINDS STAY UP TONIGHT...THOUGH IFR
VSBYS ARE SLIGHTLY POSIBLE...BUT CIGS ARE EXPECTED TO HOLD IN THE
LIFR/IFR CATEGORY DUE TO A LOW LEVEL MOIST AXIS EXTENDING ACROSS
INTO IOWA.
A COLD FRONT WILL ADVANCE EAST TOWARD THE TERMINALS MONDAY
MORNING. TIME HEIGHTS SUGGSEST A GRADUAL LIFT IN CIGS BACK INTO
MVFR AFTER DAYBREAK...BUT A DIMINISHING TREND IN THE TRACKING OF
SHOWERS ACROSS THE TERMINALS THIS MORNING HAS BEEN SEEN IN LATEST
HI-RES MODEL RUNS. SO THE PERIOD OF -SHRA MENTIONED IN THE TAFS
MAY BE A BIT OVERDONE IN THE LENGTH OF TIME. OF MORE CONCERN ARE
THE WESTERLY WINDS THAT WILL GUSTS INTO THE 20S AND POSSIBLY NEAR
30 KT BEHIND THE COLD FRONT THAT WILL MOVE THROUGH DURING THE
LATTER HALF OF MORNING PUSH.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH IN WIND DIRECTION THROUGH THE TAF. MEDIUM-HIGH IN SPEED.
* HIGH IN RAIN INITIAL TIMING THOUGH LOW IN DURATION.
* HIGH IN CIGS AND DURATION. MEDIUM IN CIGS ONLY DROPPING AS FAR
AS 400-500FT.
* MEDIUM IN VISIBILITY TRENDS AND VISIBILITY DROPPING NO MORE THAN
TO 3SM.
* MEDIUM IN CIGS/VISBYS AND SHRA DURING THE MORNING RUSH ON
MONDAY.
KMD
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...SLIGHT CHANCE OF SHRA AND MVFR. GUSTY WEST WINDS.
WEDNESDAY-THURSDAY...VFR. NORTHWEST WINDS.
FRIDAY-SATURDAY...VFR. WINDS BECOMING NORTHEAST.
MTF
&&
.MARINE...
324 PM CDT
AS A TROUGH OF LOW PRESSURE AND SECONDARY LOW PRESSURE CENTER
MOVE ACROSS THE GREAT LAKES REGION TONIGHT...WINDS WILL LIKELY BE
VARIABLE AT TIMES. THIS WILL ESPECIALLY BE THE CASE OVER THE
SOUTHERN HALF OF THE LAKE WHERE THE LOW PRESSURE SYSTEM IS
EXPECTED TO MOVE THROUGH. IN THE NEAR TERM...EAST NORTHEAST WINDS
WILL PREVAIL OVER THE LAKE WITH THE HIGHEST SPEEDS TO 30 KT
OCCURRING OVER THE NORTHERN HALF AND WHILE 15 TO 25 KT WINDS ARE
BEING OBSERVED OVER THE SOUTH...WITH SPEEDS EXPECTED TO SLIGHTLY
DIMINISH TONIGHT. AS THIS TROUGH/LOW EXIT TO THE EAST ON
MONDAY...STRONGER WESTERLY WINDS WILL DEVELOP. HIGHEST WINDS TO 30
KT WILL OCCUR ALONG THE NEARSHORE WATERS WHILE ONLY 15 TO 25 KT
ARE LIKELY OVER THE OPEN WATERS. A SIMILAR SETUP IS EXPECTED ON
TUESDAY BUT WITH SPEEDS SLIGHTLY HIGHER...AS TO 30 KT WILL LIKELY
PREVAIL FOR BOTH LOCATIONS AND WITH EVEN GALES POSSIBLE ALONG THE
NEARSHORE WATERS DURING THE DAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...11 AM MONDAY TO 9 PM MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
ISSUED BY NATIONAL WEATHER SERVICE LA CROSSE WI
1230 PM CDT MON APR 20 2015
.SYNOPSIS...
ISSUED AT 335 AM CDT MON APR 20 2015
DEEPENING CYCLONE (987 MB) WAS LOCATED IN EXTREME WESTERN LOWER MI
AND BROUGHT WIDESPREAD RAIN TO THE DVN CWA LAST EVENING AND OVERNIGHT.
A COLD FRONT HAS SWEPT THROUGH THE AREA WITH NORTHWEST WINDS GUSTING
TO 35 MPH. DOPPLER RADAR INDICATED LIGHT RAIN STILL FALLING ROUGHLY
ALONG AND NORTH OF HIGHWAY 30 IN IA AND IL AND WAS GRADUALLY LIFTING
NORTHWARD. CURRENT TEMPERATURES RANGED FROM THE LOWER 40S TO MID 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT MON APR 20 2015
FORECAST FOCUS ON RAIN CHANCES...WIND AND TEMPERATURES.
TODAY...THIS WILL BE A VERY WINDY AND MUCH COOLER DAY AS THE DEEPENING
CYCLONE TRACKS NORTHWARD TO JUST NORTH OF LAKE SUPERIOR. THE STRATIFORM
RAIN SHIELD SHOULD LIFT OUT OF THE DVN CWA BY MID TO LATE MORNING.
OTHERWISE PARTLY SUNNY SKIES ARE EXPECTED WITH FORECAST SOUNDINGS
INDICATING DEEP MIXING TO ABOUT 700 MB BRINGING DOWN 35 TO 40 MPH
WIND GUSTS...WHICH IS BELOW ADVISORY CRITERIA. NONETHELESS HANG ONTO
YOUR HAT AND THE STEERING WHEEL! STEEP LAPSE RATES AND ENOUGH MOISTURE
SHOULD ALLOW FOR ISOLATED HIGH-BASED RAIN SHOWERS ANYWHERE IN THE CWA
LATER THIS MORNING THROUGH THE AFTERNOON. THE HRRR AND WRF MODELS DEPICT
THIS SCENARIO QUITE WELL. TEMPERATURES WILL BE A CHALLENGE AGAIN AS
WE HAVE COLD AIR ADVECTION BUT THERE WILL ALSO BE SOME SUNSHINE TO
OFFSET THIS SOMEWHAT. THEREFORE A GOOD COMPROMISE SEEMS TO BE HIGHS
IN THE UPPER 50S TO LOWER 60S.
TONIGHT...DEEP CYCLONE (980 MB) WILL BE ANCHORED NORTH OF LAKE SUPERIOR
DUE TO A STRONG GREENLAND BLOCK. SKIES SHOULD BE PARTLY CLOUDY AND GUSTY
WEST WINDS WILL DIMINISH BY SUNSET WITH DECOUPLING. HOWEVER... THE WINDS
SHOULD STAY AT 10 TO 15 MPH MUCH OF THE NIGHT. MINIMUM TEMPERATURES
IN THE 35 TO 40 RANGE SHOULD BE COMMON. A FEW SHOWERS MAY LINGER INTO
THE EARLY EVENING HOURS FOR LATER SHIFTS TO CONSIDER...BUT FOR NOW I
WILL CONTINUE A DRY FORECAST FOR TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 AM CDT MON APR 20 2015
SEASONABLY COOL AND MAINLY DRY FOR MUCH OF THE WEEK WITH FROST/FREEZE
POTENTIAL LATER IN THE WEEK.
NORTHWEST FLOW PATTERN WILL GOVERN MUCH OF THE LONG TERM PERIOD AS
BLOCKING DEVELOPS OVER EASTERN ATLANTIC AND GREENLAND RESULTING IN
SLOW EASTWARD PROGRESSION OF GREAT LAKES UPPER LOW. SERIES OF
IMPULSES WILL ROTATE AROUND THE CYCLONE WITH NORTHERN CWA IN CLOSER
PROXIMITY AND THUS FAVORED FOR MORE DIURNAL DRIVEN CLOUD COVER ON
TUESDAY ALONG WITH SPRINKLES AND SOME LIGHT POPCORN SHOWERS GIVEN
STEEP LAPSE RATES...COLD AIR ALOFT AND PRESENCE OF SKINNY CAPE NOTED
ON FORECAST SOUNDINGS. MAIN ITEM ON TUESDAY WILL BE WINDY CONDITIONS
WITH POTENTIAL FOR WIND ADVISORY AS NAM/GFS BUFR SOUNDINGS SHOWING
30-35 KTS OF WIND ON AVERAGE THROUGH THE MIXED LAYER WITH 50-55 KTS
SITTING ATOP DEEP MIXED LAYER TO NEAR 650 MB. POSSIBLE AS WELL THAT
ANY SHOWERS COULD ENHANCE WIND GUSTS VIA EVAPORATIVE COOLING OF
PCPN IN LARGE... DRY SUB-CLOUD LAYER WITH CLASSIC INVERTED V TYPE
SOUNDINGS.
CANADIAN SURFACE RIDGE AXIS WILL BUILD IN OVER THE LATTER HALF OF THE
WEEK AS THE UPPER LOW PLODS EASTWARD FROM GREAT LAKES. THIS WILL
BRING DIMINISHING WINDS WEDNESDAY THROUGH FRIDAY BUT ALSO REINFORCE
COOL... DRY AIR WITH MORE IDEAL RADIATIONAL COOLING SETUP LEADING TO
INCREASING RISK FOR AREAS OF FROST AND FREEZING TEMPS POSSIBLY AS
EARLY AS WEDNESDAY AM... BUT MORE LIKELY THURSDAY/FRIDAY AM. FREEZE
HIGHLIGHTS ARE ACTIVE IF NEEDED WITH FRUIT TREES NOW SUSCEPTIBLE
TO TEMPS AT/BELOW 28F PER FEEDBACK FROM ISU EXTENSION COMMERCIAL
HORTICULTURE SPECIALIST. NURSERIES AND STORES ALSO MOVING
STOCK OUTDOORS... AND RECENT WARM SPELL AND MOISTURE HAS CAUSED YARDS
TO ADVANCE QUICKLY.
TOWARD SATURDAY AND INTO THE FIRST HALF OF THE WEEKEND THERE IS THE
POTENTIAL FOR RAIN CHANCES WITH ANOTHER STORM SYSTEM. CONFIDENCE IS
LOW AS MODEL VARIANCE QUITE HIGH. DPROG/DT... OR COMPARISON OF MODELS
RUN TO RUN... SHOWS BETTER CONSISTENCY EXISTS WITH ECMWF WHICH IS
SLOWER AND FAVORS SOUTHERN CWA FOR BETTER RAIN CHANCES DUE TO MORE
SOUTHERLY TRACK OF SYSTEM AND INCREASING EASTERLY FLOW. GFS ENSEMBLE
MEANS SIMILAR LINES OF ECMWF AND ACTUALLY SUGGEST MUCH IF NOT ALL OF
RAIN STAYING TO OUR SOUTH FROM PARTS OF MID TO LOWER MISSISSIPPI VLY
WHICH ALSO FITS WITH PATTERN OF LATE. AS RESULT... HAVE ADJUSTED POPS
TO LOWER OR REMOVE ACROSS THE NORTH/EAST FRIDAY NIGHT AND SATURDAY AND
PLACE THE BEST CHANCES ACROSS THE SOUTHERN CWA.
TEMPS THROUGHOUT THE ENTIRE PERIOD LOOK TO REMAIN SEASONABLY COOL WITH
HIGHS 50S/60S... AND LOWS MAINLY IN THE 30S WITH SOME 20S IN FAVORED
DRAINAGE LOCATIONS WEDNESDAY THROUGH FRIDAY MORNINGS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1230 PM CDT MON APR 20 2015
BROAD CYCLONIC FLOW OVER CORN BELT AND GREAT LAKES IS LEADING TO
COLD AIR ADVECTION STRATUS ALONG WITH DIURNAL CONVECTION. GAPS IN
CLOUD COVER FILLED IN QUICKLY EARLIER TODAY WITH HEATING. CEILINGS
MAINLY IN VFR CATEGORY BUT SOME MVFR THE FURTHER NORTH YOU GO...INTO
THE SYNOPTIC STRATUS. STRONG NORTHWEST FLOW ALSO CREATING HAVOC WITH
AVIATION...BUT PRESSURE GRADIENT SHOULD BEGIN TO RELAX SOMEWHAT AS
AFTERNOON WEARS ON. COULD ALSO SEE SOME INSTABILITY SHOWERS DEVELOP
BUT THEY WILL REMAIN SPOTTY AND SHOULD HAVE LIMITED IMPACT.
DIURNAL CLOUDS THIS AFTERNOON SHOULD CLEAR OUT THIS EVENING...SO
CLOUDS WILL VARY FROM MOSTLY CLEAR SOUTH TO MOSTLY CLOUDY NORTH BUT
SHOULD REMAIN VFR.
ANOTHER WAVE IN NORTHWEST FLOW AROUND LARGE UPPER LOW WILL LEAD TO
MORE DIURNAL CLOUD DEVELOPMENT ON TUESDAY. PRESSURE GRADIENT THAT
DEVELOPS WITH THIS FEATURE COULD BE TIGHTER THAN TODAY SO EXPECT
EVEN STRONGER WINDS IN OUTER FORECAST HOURS AND INTO NEXT TAF UPDATE.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...HAASE
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...MCCLURE
AVIATION...SHEA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
719 AM CDT MON APR 20 2015
.UPDATE...
ISSUED AT 718 AM CDT MON APR 20 2015
DOPPLER RADAR INDICATED THE WEST (BACK) EDGE OF THE DEFORMATION ZONE
PRODUCING LIGHT RAIN AND SPRINKLES EXTENDED FROM ABOUT MANCHESTER IA
TO THE QUAD CITIES AND WAS MOVING EAST AT ABOUT 20 MPH. THIS PUTS THE
BACK EDGE EXITING THE DVN CWA BY AROUND 10 AM OR SO. NORTHWEST
WINDS HAVE BEEN GUSTING TO 30 TO 40 MPH THE PAST SEVERAL HOURS AND
EARLIER I ISSUED A SPECIAL WEATHER STATEMENT FOR THE MORNING COMMUTE.
HOWEVER...WINDS WILL REMAIN STRONG FOR MUCH OF THE DAY AND THEN
DIMINISH QUICKLY TOWARDS SUNSET.
THE LATEST HRRR AND WRF MODELS HAVE COME IN A BIT MORE AGGRESSIVE
WITH THE SHOWERS ACROSS THE CWA. THEREFORE HAVE RAISED POPS TO 30
PERCENT AND DESCRIBED IT AS "ISOLATED TO SCATTERED SHOWERS".
&&
.SYNOPSIS...
ISSUED AT 335 AM CDT MON APR 20 2015
DEEPENING CYCLONE (987 MB) WAS LOCATED IN EXTREME WESTERN LOWER MI
AND BROUGHT WIDESPREAD RAIN TO THE DVN CWA LAST EVENING AND OVERNIGHT.
A COLD FRONT HAS SWEPT THROUGH THE AREA WITH NORTHWEST WINDS GUSTING
TO 35 MPH. DOPPLER RADAR INDICATED LIGHT RAIN STILL FALLING ROUGHLY
ALONG AND NORTH OF HIGHWAY 30 IN IA AND IL AND WAS GRADUALLY LIFTING
NORTHWARD. CURRENT TEMPERATURES RANGED FROM THE LOWER 40S TO MID 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT MON APR 20 2015
FORECAST FOCUS ON RAIN CHANCES...WIND AND TEMPERATURES.
TODAY...THIS WILL BE A VERY WINDY AND MUCH COOLER DAY AS THE DEEPENING
CYCLONE TRACKS NORTHWARD TO JUST NORTH OF LAKE SUPERIOR. THE STRATIFORM
RAIN SHIELD SHOULD LIFT OUT OF THE DVN CWA BY MID TO LATE MORNING.
OTHERWISE PARTLY SUNNY SKIES ARE EXPECTED WITH FORECAST SOUNDINGS
INDICATING DEEP MIXING TO ABOUT 700 MB BRINGING DOWN 35 TO 40 MPH
WIND GUSTS...WHICH IS BELOW ADVISORY CRITERIA. NONETHELESS HANG ONTO
YOUR HAT AND THE STEERING WHEEL! STEEP LAPSE RATES AND ENOUGH MOISTURE
SHOULD ALLOW FOR ISOLATED HIGH-BASED RAIN SHOWERS ANYWHERE IN THE CWA
LATER THIS MORNING THROUGH THE AFTERNOON. THE HRRR AND WRF MODELS DEPICT
THIS SCENARIO QUITE WELL. TEMPERATURES WILL BE A CHALLENGE AGAIN AS
WE HAVE COLD AIR ADVECTION BUT THERE WILL ALSO BE SOME SUNSHINE TO
OFFSET THIS SOMEWHAT. THEREFORE A GOOD COMPROMISE SEEMS TO BE HIGHS
IN THE UPPER 50S TO LOWER 60S.
TONIGHT...DEEP CYCLONE (980 MB) WILL BE ANCHORED NORTH OF LAKE SUPERIOR
DUE TO A STRONG GREENLAND BLOCK. SKIES SHOULD BE PARTLY CLOUDY AND GUSTY
WEST WINDS WILL DIMINISH BY SUNSET WITH DECOUPLING. HOWEVER... THE WINDS
SHOULD STAY AT 10 TO 15 MPH MUCH OF THE NIGHT. MINIMUM TEMPERATURES
IN THE 35 TO 40 RANGE SHOULD BE COMMON. A FEW SHOWERS MAY LINGER INTO
THE EARLY EVENING HOURS FOR LATER SHIFTS TO CONSIDER...BUT FOR NOW I
WILL CONTINUE A DRY FORECAST FOR TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 AM CDT MON APR 20 2015
SEASONABLY COOL AND MAINLY DRY FOR MUCH OF THE WEEK WITH FROST/FREEZE
POTENTIAL LATER IN THE WEEK.
NORTHWEST FLOW PATTERN WILL GOVERN MUCH OF THE LONG TERM PERIOD AS
BLOCKING DEVELOPS OVER EASTERN ATLANTIC AND GREENLAND RESULTING IN
SLOW EASTWARD PROGRESSION OF GREAT LAKES UPPER LOW. SERIES OF
IMPULSES WILL ROTATE AROUND THE CYCLONE WITH NORTHERN CWA IN CLOSER
PROXIMITY AND THUS FAVORED FOR MORE DIURNAL DRIVEN CLOUD COVER ON
TUESDAY ALONG WITH SPRINKLES AND SOME LIGHT POPCORN SHOWERS GIVEN
STEEP LAPSE RATES...COLD AIR ALOFT AND PRESENCE OF SKINNY CAPE NOTED
ON FORECAST SOUNDINGS. MAIN ITEM ON TUESDAY WILL BE WINDY CONDITIONS
WITH POTENTIAL FOR WIND ADVISORY AS NAM/GFS BUFR SOUNDINGS SHOWING
30-35 KTS OF WIND ON AVERAGE THROUGH THE MIXED LAYER WITH 50-55 KTS
SITTING ATOP DEEP MIXED LAYER TO NEAR 650 MB. POSSIBLE AS WELL THAT
ANY SHOWERS COULD ENHANCE WIND GUSTS VIA EVAPORATIVE COOLING OF
PCPN IN LARGE... DRY SUB-CLOUD LAYER WITH CLASSIC INVERTED V TYPE
SOUNDINGS.
CANADIAN SURFACE RIDGE AXIS WILL BUILD IN OVER THE LATTER HALF OF THE
WEEK AS THE UPPER LOW PLODS EASTWARD FROM GREAT LAKES. THIS WILL
BRING DIMINISHING WINDS WEDNESDAY THROUGH FRIDAY BUT ALSO REINFORCE
COOL... DRY AIR WITH MORE IDEAL RADIATIONAL COOLING SETUP LEADING TO
INCREASING RISK FOR AREAS OF FROST AND FREEZING TEMPS POSSIBLY AS
EARLY AS WEDNESDAY AM... BUT MORE LIKELY THURSDAY/FRIDAY AM. FREEZE
HIGHLIGHTS ARE ACTIVE IF NEEDED WITH FRUIT TREES NOW SUSCEPTIBLE
TO TEMPS AT/BELOW 28F PER FEEDBACK FROM ISU EXTENSION COMMERCIAL
HORTICULTURE SPECIALIST. NURSERIES AND STORES ALSO MOVING
STOCK OUTDOORS... AND RECENT WARM SPELL AND MOISTURE HAS CAUSED YARDS
TO ADVANCE QUICKLY.
TOWARD SATURDAY AND INTO THE FIRST HALF OF THE WEEKEND THERE IS THE
POTENTIAL FOR RAIN CHANCES WITH ANOTHER STORM SYSTEM. CONFIDENCE IS
LOW AS MODEL VARIANCE QUITE HIGH. DPROG/DT... OR COMPARISON OF MODELS
RUN TO RUN... SHOWS BETTER CONSISTENCY EXISTS WITH ECMWF WHICH IS
SLOWER AND FAVORS SOUTHERN CWA FOR BETTER RAIN CHANCES DUE TO MORE
SOUTHERLY TRACK OF SYSTEM AND INCREASING EASTERLY FLOW. GFS ENSEMBLE
MEANS SIMILAR LINES OF ECMWF AND ACTUALLY SUGGEST MUCH IF NOT ALL OF
RAIN STAYING TO OUR SOUTH FROM PARTS OF MID TO LOWER MISSISSIPPI VLY
WHICH ALSO FITS WITH PATTERN OF LATE. AS RESULT... HAVE ADJUSTED POPS
TO LOWER OR REMOVE ACROSS THE NORTH/EAST FRIDAY NIGHT AND SATURDAY AND
PLACE THE BEST CHANCES ACROSS THE SOUTHERN CWA.
TEMPS THROUGHOUT THE ENTIRE PERIOD LOOK TO REMAIN SEASONABLY COOL WITH
HIGHS 50S/60S... AND LOWS MAINLY IN THE 30S WITH SOME 20S IN FAVORED
DRAINAGE LOCATIONS WEDNESDAY THROUGH FRIDAY MORNINGS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 648 AM CDT MON APR 20 2015
MVFR CIGS THIS MORNING THEN VFR CIGS THIS AFTERNOON AND VFR NO CIGS
TONIGHT. ISOLATED TO SCATTERED SHOWERS LATE THIS MORNING THROUGH THE
AFTERNOON. NORTHWEST WINDS SUSTAINED 15 TO 20 KNOTS WITH GUSTS TO
30 KNOTS TODAY THEN WEST 10 TO 15 KNOTS TONIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...HAASE
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...MCCLURE
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
651 AM CDT MON APR 20 2015
.SYNOPSIS...
ISSUED AT 335 AM CDT MON APR 20 2015
DEEPENING CYCLONE (987 MB) WAS LOCATED IN EXTREME WESTERN LOWER MI
AND BROUGHT WIDESPREAD RAIN TO THE DVN CWA LAST EVENING AND OVERNIGHT.
A COLD FRONT HAS SWEPT THROUGH THE AREA WITH NORTHWEST WINDS GUSTING
TO 35 MPH. DOPPLER RADAR INDICATED LIGHT RAIN STILL FALLING ROUGHLY
ALONG AND NORTH OF HIGHWAY 30 IN IA AND IL AND WAS GRADUALLY LIFTING
NORTHWARD. CURRENT TEMPERATURES RANGED FROM THE LOWER 40S TO MID 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT MON APR 20 2015
FORECAST FOCUS ON RAIN CHANCES...WIND AND TEMPERATURES.
TODAY...THIS WILL BE A VERY WINDY AND MUCH COOLER DAY AS THE DEEPENING
CYCLONE TRACKS NORTHWARD TO JUST NORTH OF LAKE SUPERIOR. THE STRATIFORM
RAIN SHIELD SHOULD LIFT OUT OF THE DVN CWA BY MID TO LATE MORNING.
OTHERWISE PARTLY SUNNY SKIES ARE EXPECTED WITH FORECAST SOUNDINGS
INDICATING DEEP MIXING TO ABOUT 700 MB BRINGING DOWN 35 TO 40 MPH
WIND GUSTS...WHICH IS BELOW ADVISORY CRITERIA. NONETHELESS HANG ONTO
YOUR HAT AND THE STEERING WHEEL! STEEP LAPSE RATES AND ENOUGH MOISTURE
SHOULD ALLOW FOR ISOLATED HIGH-BASED RAIN SHOWERS ANYWHERE IN THE CWA
LATER THIS MORNING THROUGH THE AFTERNOON. THE HRRR AND WRF MODELS DEPICT
THIS SCENARIO QUITE WELL. TEMPERATURES WILL BE A CHALLENGE AGAIN AS
WE HAVE COLD AIR ADVECTION BUT THERE WILL ALSO BE SOME SUNSHINE TO
OFFSET THIS SOMEWHAT. THEREFORE A GOOD COMPROMISE SEEMS TO BE HIGHS
IN THE UPPER 50S TO LOWER 60S.
TONIGHT...DEEP CYCLONE (980 MB) WILL BE ANCHORED NORTH OF LAKE SUPERIOR
DUE TO A STRONG GREENLAND BLOCK. SKIES SHOULD BE PARTLY CLOUDY AND GUSTY
WEST WINDS WILL DIMINISH BY SUNSET WITH DECOUPLING. HOWEVER... THE WINDS
SHOULD STAY AT 10 TO 15 MPH MUCH OF THE NIGHT. MINIMUM TEMPERATURES
IN THE 35 TO 40 RANGE SHOULD BE COMMON. A FEW SHOWERS MAY LINGER INTO
THE EARLY EVENING HOURS FOR LATER SHIFTS TO CONSIDER...BUT FOR NOW I
WILL CONTINUE A DRY FORECAST FOR TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 AM CDT MON APR 20 2015
SEASONABLY COOL AND MAINLY DRY FOR MUCH OF THE WEEK WITH FROST/FREEZE
POTENTIAL LATER IN THE WEEK.
NORTHWEST FLOW PATTERN WILL GOVERN MUCH OF THE LONG TERM PERIOD AS
BLOCKING DEVELOPS OVER EASTERN ATLANTIC AND GREENLAND RESULTING IN
SLOW EASTWARD PROGRESSION OF GREAT LAKES UPPER LOW. SERIES OF
IMPULSES WILL ROTATE AROUND THE CYCLONE WITH NORTHERN CWA IN CLOSER
PROXIMITY AND THUS FAVORED FOR MORE DIURNAL DRIVEN CLOUD COVER ON
TUESDAY ALONG WITH SPRINKLES AND SOME LIGHT POPCORN SHOWERS GIVEN
STEEP LAPSE RATES...COLD AIR ALOFT AND PRESENCE OF SKINNY CAPE NOTED
ON FORECAST SOUNDINGS. MAIN ITEM ON TUESDAY WILL BE WINDY CONDITIONS
WITH POTENTIAL FOR WIND ADVISORY AS NAM/GFS BUFR SOUNDINGS SHOWING
30-35 KTS OF WIND ON AVERAGE THROUGH THE MIXED LAYER WITH 50-55 KTS
SITTING ATOP DEEP MIXED LAYER TO NEAR 650 MB. POSSIBLE AS WELL THAT
ANY SHOWERS COULD ENHANCE WIND GUSTS VIA EVAPORATIVE COOLING OF
PCPN IN LARGE... DRY SUB-CLOUD LAYER WITH CLASSIC INVERTED V TYPE
SOUNDINGS.
CANADIAN SURFACE RIDGE AXIS WILL BUILD IN OVER THE LATTER HALF OF THE
WEEK AS THE UPPER LOW PLODS EASTWARD FROM GREAT LAKES. THIS WILL
BRING DIMINISHING WINDS WEDNESDAY THROUGH FRIDAY BUT ALSO REINFORCE
COOL... DRY AIR WITH MORE IDEAL RADIATIONAL COOLING SETUP LEADING TO
INCREASING RISK FOR AREAS OF FROST AND FREEZING TEMPS POSSIBLY AS
EARLY AS WEDNESDAY AM... BUT MORE LIKELY THURSDAY/FRIDAY AM. FREEZE
HIGHLIGHTS ARE ACTIVE IF NEEDED WITH FRUIT TREES NOW SUSCEPTIBLE
TO TEMPS AT/BELOW 28F PER FEEDBACK FROM ISU EXTENSION COMMERCIAL
HORTICULTURE SPECIALIST. NURSERIES AND STORES ALSO MOVING
STOCK OUTDOORS... AND RECENT WARM SPELL AND MOISTURE HAS CAUSED YARDS
TO ADVANCE QUICKLY.
TOWARD SATURDAY AND INTO THE FIRST HALF OF THE WEEKEND THERE IS THE
POTENTIAL FOR RAIN CHANCES WITH ANOTHER STORM SYSTEM. CONFIDENCE IS
LOW AS MODEL VARIANCE QUITE HIGH. DPROG/DT... OR COMPARISON OF MODELS
RUN TO RUN... SHOWS BETTER CONSISTENCY EXISTS WITH ECMWF WHICH IS
SLOWER AND FAVORS SOUTHERN CWA FOR BETTER RAIN CHANCES DUE TO MORE
SOUTHERLY TRACK OF SYSTEM AND INCREASING EASTERLY FLOW. GFS ENSEMBLE
MEANS SIMILAR LINES OF ECMWF AND ACTUALLY SUGGEST MUCH IF NOT ALL OF
RAIN STAYING TO OUR SOUTH FROM PARTS OF MID TO LOWER MISSISSIPPI VLY
WHICH ALSO FITS WITH PATTERN OF LATE. AS RESULT... HAVE ADJUSTED POPS
TO LOWER OR REMOVE ACROSS THE NORTH/EAST FRIDAY NIGHT AND SATURDAY AND
PLACE THE BEST CHANCES ACROSS THE SOUTHERN CWA.
TEMPS THROUGHOUT THE ENTIRE PERIOD LOOK TO REMAIN SEASONABLY COOL WITH
HIGHS 50S/60S... AND LOWS MAINLY IN THE 30S WITH SOME 20S IN FAVORED
DRAINAGE LOCATIONS WEDNESDAY THROUGH FRIDAY MORNINGS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 648 AM CDT MON APR 20 2015
MVFR CIGS THIS MORNING THEN VFR CIGS THIS AFTERNOON AND VFR NO CIGS
TONIGHT. ISOLATED TO SCATTERED SHOWERS LATE THIS MORNING THROUGH THE
AFTERNOON. NORTHWEST WINDS SUSTAINED 15 TO 20 KNOTS WITH GUSTS TO
30 KNOTS TODAY THEN WEST 10 TO 15 KNOTS TONIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...MCCLURE
AVIATION...HAASE
AREA FORECAST DISCUSSION...CORRECTED TYPO IN FIRST PARAGRAPH OF LONG TERM
NWS QUAD CITIES IA IL
346 AM CDT MON APR 20 2015
.SYNOPSIS...
ISSUED AT 335 AM CDT MON APR 20 2015
DEEPENING CYCLONE (987 MB) WAS LOCATED IN EXTREME WESTERN LOWER MI
AND BROUGHT WIDESPREAD RAIN TO THE DVN CWA LAST EVENING AND OVERNIGHT.
A COLD FRONT HAS SWEPT THROUGH THE AREA WITH NORTHWEST WINDS GUSTING
TO 35 MPH. DOPPLER RADAR INDICATED LIGHT RAIN STILL FALLING ROUGHLY
ALONG AND NORTH OF HIGHWAY 30 IN IA AND IL AND WAS GRADUALLY LIFTING
NORTHWARD. CURRENT TEMPERATURES RANGED FROM THE LOWER 40S TO MID 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT MON APR 20 2015
FORECAST FOCUS ON RAIN CHANCES...WIND AND TEMPERATURES.
TODAY...THIS WILL BE A VERY WINDY AND MUCH COOLER DAY AS THE DEEPENING
CYCLONE TRACKS NORTHWARD TO JUST NORTH OF LAKE SUPERIOR. THE STRATIFORM
RAIN SHIELD SHOULD LIFT OUT OF THE DVN CWA BY MID TO LATE MORNING.
OTHERWISE PARTLY SUNNY SKIES ARE EXPECTED WITH FORECAST SOUNDINGS
INDICATING DEEP MIXING TO ABOUT 700 MB BRINGING DOWN 35 TO 40 MPH
WIND GUSTS...WHICH IS BELOW ADVISORY CRITERIA. NONETHELESS HANG ONTO
YOUR HAT AND THE STEERING WHEEL! STEEP LAPSE RATES AND ENOUGH MOISTURE
SHOULD ALLOW FOR ISOLATED HIGH-BASED RAIN SHOWERS ANYWHERE IN THE CWA
LATER THIS MORNING THROUGH THE AFTERNOON. THE HRRR AND WRF MODELS DEPICT
THIS SCENARIO QUITE WELL. TEMPERATURES WILL BE A CHALLENGE AGAIN AS
WE HAVE COLD AIR ADVECTION BUT THERE WILL ALSO BE SOME SUNSHINE TO
OFFSET THIS SOMEWHAT. THEREFORE A GOOD COMPROMISE SEEMS TO BE HIGHS
IN THE UPPER 50S TO LOWER 60S.
TONIGHT...DEEP CYCLONE (980 MB) WILL BE ANCHORED NORTH OF LAKE SUPERIOR
DUE TO A STRONG GREENLAND BLOCK. SKIES SHOULD BE PARTLY CLOUDY AND GUSTY
WEST WINDS WILL DIMINISH BY SUNSET WITH DECOUPLING. HOWEVER... THE WINDS
SHOULD STAY AT 10 TO 15 MPH MUCH OF THE NIGHT. MINIMUM TEMPERATURES
IN THE 35 TO 40 RANGE SHOULD BE COMMON. A FEW SHOWERS MAY LINGER INTO
THE EARLY EVENING HOURS FOR LATER SHIFTS TO CONSIDER...BUT FOR NOW I
WILL CONTINUE A DRY FORECAST FOR TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 AM CDT MON APR 20 2015
SEASONABLY COOL AND MAINLY DRY FOR MUCH OF THE WEEK WITH FROST/FREEZE
POTENTIAL LATER IN THE WEEK.
NORTHWEST FLOW PATTERN WILL GOVERN MUCH OF THE LONG TERM PERIOD AS
BLOCKING DEVELOPS OVER EASTERN ATLANTIC AND GREENLAND RESULTING IN
SLOW EASTWARD PROGRESSION OF GREAT LAKES UPPER LOW. SERIES OF
IMPULSES WILL ROTATE AROUND THE CYCLONE WITH NORTHERN CWA IN CLOSER
PROXIMITY AND THUS FAVORED FOR MORE DIURNAL DRIVEN CLOUD COVER ON
TUESDAY ALONG WITH SPRINKLES AND SOME LIGHT POPCORN SHOWERS GIVEN
STEEP LAPSE RATES...COLD AIR ALOFT AND PRESENCE OF SKINNY CAPE NOTED
ON FORECAST SOUNDINGS. MAIN ITEM ON TUESDAY WILL BE WINDY CONDITIONS
WITH POTENTIAL FOR WIND ADVISORY AS NAM/GFS BUFR SOUNDINGS SHOWING
30-35 KTS OF WIND ON AVERAGE THROUGH THE MIXED LAYER WITH 50-55 KTS
SITTING ATOP DEEP MIXED LAYER TO NEAR 650 MB. POSSIBLE AS WELL THAT
ANY SHOWERS COULD ENHANCE WIND GUSTS VIA EVAPORATIVE COOLING OF
PCPN IN LARGE... DRY SUB-CLOUD LAYER WITH CLASSIC INVERTED V TYPE
SOUNDINGS.
CANADIAN SURFACE RIDGE AXIS WILL BUILD IN OVER THE LATTER HALF OF THE
WEEK AS THE UPPER LOW PLODS EASTWARD FROM GREAT LAKES. THIS WILL
BRING DIMINISHING WINDS WEDNESDAY THROUGH FRIDAY BUT ALSO REINFORCE
COOL... DRY AIR WITH MORE IDEAL RADIATIONAL COOLING SETUP LEADING TO
INCREASING RISK FOR AREAS OF FROST AND FREEZING TEMPS POSSIBLY AS
EARLY AS WEDNESDAY AM... BUT MORE LIKELY THURSDAY/FRIDAY AM. FREEZE
HIGHLIGHTS ARE ACTIVE IF NEEDED WITH FRUIT TREES NOW SUSCEPTIBLE
TO TEMPS AT/BELOW 28F PER FEEDBACK FROM ISU EXTENSION COMMERCIAL
HORTICULTURE SPECIALIST. NURSERIES AND STORES ALSO MOVING
STOCK OUTDOORS... AND RECENT WARM SPELL AND MOISTURE HAS CAUSED YARDS
TO ADVANCE QUICKLY.
TOWARD SATURDAY AND INTO THE FIRST HALF OF THE WEEKEND THERE IS THE
POTENTIAL FOR RAIN CHANCES WITH ANOTHER STORM SYSTEM. CONFIDENCE IS
LOW AS MODEL VARIANCE QUITE HIGH. DPROG/DT... OR COMPARISON OF MODELS
RUN TO RUN... SHOWS BETTER CONSISTENCY EXISTS WITH ECMWF WHICH IS
SLOWER AND FAVORS SOUTHERN CWA FOR BETTER RAIN CHANCES DUE TO MORE
SOUTHERLY TRACK OF SYSTEM AND INCREASING EASTERLY FLOW. GFS ENSEMBLE
MEANS SIMILAR LINES OF ECMWF AND ACTUALLY SUGGEST MUCH IF NOT ALL OF
RAIN STAYING TO OUR SOUTH FROM PARTS OF MID TO LOWER MISSISSIPPI VLY
WHICH ALSO FITS WITH PATTERN OF LATE. AS RESULT... HAVE ADJUSTED POPS
TO LOWER OR REMOVE ACROSS THE NORTH/EAST FRIDAY NIGHT AND SATURDAY AND
PLACE THE BEST CHANCES ACROSS THE SOUTHERN CWA.
TEMPS THROUGHOUT THE ENTIRE PERIOD LOOK TO REMAIN SEASONABLY COOL WITH
HIGHS 50S/60S... AND LOWS MAINLY IN THE 30S WITH SOME 20S IN FAVORED
DRAINAGE LOCATIONS WEDNESDAY THROUGH FRIDAY MORNINGS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1131 PM CDT SUN APR 19 2015
COMPLEX STORM SYSTEM CONTINUES PROGRESSING ACROSS THE MIDWEST AND
PRODUCING WIDESPREAD RAIN WITH IFR-MVFR CIGS AND VSBYS IN EASTERN
IOWA AND NORTHWEST ILLINOIS. THE SYSTEM SHOULD BEGIN EXITING THE
REGION TOWARD SUNRISE. MEANWHILE A SURFACE COLD FRONT ASSOCIATED
WITH THE SYSTEM HAS REACHED ROUGHLY ALONG THE MISSISSIPPI RIVER
AT 04Z. VERY STRONG AND GUSTY NORTHWEST WINDS ARE FOLLOWING THE
FRONT AND WILL CONTINUE MONDAY. WHILE VFR CONDITIONS ARE ON TAP
MONDAY...SCATTERED AFTERNOON INSTABILITY SHOWERS MAY DEVELOP
CAUSING LOCALIZED MVFR VSBYS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...MCCLURE
AVIATION...WOLF
AREA FORECAST DISCUSSION
NWS PADUCAH KY
622 PM CDT TUE APR 21 2015
.UPDATE...
FOR AVIATION SECTION ONLY.
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 215 PM CDT TUE APR 21 2015
NEAR TERM ON TRACK...AS CONVECTION CONTINUES TO TAKE SHAPE OVER
SOUTHERN INTO SOUTHEAST MISSOURI...LIGHTNING NOW OBSERVED WEST OF
OUR CWFA. WILL CONTINUE TO MONITOR FOR THE POSSIBILITY OF SOME
HAIL AND GUSTY WINDS GIVEN THE STEEP LAPSE RATES AND LOW FREEZING
LEVELS...DESPITE LACK OF LOW LEVEL MOISTURE. THE CHANCES WILL
CONTINUE THROUGH THE OVERNIGHT AS A BOUNDARY SETTLES SOUTH ACROSS
THE REGION. WILL DIMINISH POPS FROM NW TO SE WEDNESDAY MORNING...DRY
BY AFTERNOON. WILL KEEP IT DRY WEDNESDAY NIGHT THROUGH THURSDAY
WITH WEAK HIGH PRESSURE ANGLING IN FROM THE UPPER MIDWEST. CHANCES
OF SHOWERS MAY EXIST JUST SOUTH OF THE AREA NEAR OUR CWFA BORDER.
CAN ADJUST IF NEED BE. TEMPS A BLEND OF MOS AND EXISTING NUMBERS.
NAM HIGH RES AND HRRR A REASONABLE APPROACH FOR CONVECTIVE TRENDS
THROUGH 06Z.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 215 PM CDT TUE APR 21 2015
THE OPERATIONAL MODELS ARE TRYING TO FALL SOMEWHAT IN LINE WITH
PRIOR ENSEMBLE MEAN SOLUTIONS THROUGH SUNDAY. ALL IN ALL...
CONFIDENCE CONTINUES TO INCREASE FOR THE FIRST SYSTEM FRIDAY
THROUGH SATURDAY. UPPER TROF SHOULD EJECT NE INTO THE PLAINS BY
00Z SAT WITH MOISTURE QUICKLY SPREADING EAST BY FRIDAY AFTERNOON
AND EVENING. S/WV RIDGE AHEAD OF THE TROF NOT STRONG ENOUGH TO
WARD OFF ONCOMING SHRA/TSRA CHANCE. SO WE ARE ON THE AGGRESSIVE
SIDE OF THE ENVELOPE. LIKELY POPS STILL IN PLAY FOR FRIDAY NIGHT
WITH CHANCE TO LOW END LIKELY SATURDAY AS WELL...AS THE UPPER TROF
WEAKENS...AND THE REMNANT ENERGY TURNS ESE ACROSS THE AREA
SATURDAY...CONTINUING THE CHANCE OF CONVECTION. SURFACE BOUNDARY
SHOULD STAY JUST TO OUR SOUTH...SO ESSENTIALLY ELEVATED CONVECTION.
CHANCES TAIL OFF SATURDAY NIGHT WITH A DRY FORECAST IN PLACE FOR
SUNDAY. FOR MONDAY THROUGH TUESDAY...THE ENSEMBLE MEAN SOLUTIONS
WERE UTILIZED AND OPERATIONAL MODELS THROWN OUT. A HIGHLY COMPLEX
PATTERN IS FORECAST TO EVOLVE WITH SOME KIND OF A TROUGH EAST OF
THE PLAINS AND RIDGE WEST. HOWEVER THERE IS TOO MUCH VARIABILITY
IN THE DETAILS TO SIDE WITH ANY OPS SOLUTION AT THIS POINT. ITS
GOING TO CHANGE. WE FEE COMFORTABLE MAINTAINING LOW CHANCE POPS
FOR SHOWERS GIVEN THE UNSETTLED LOOK TO THE PATTERN. TEMPS WERE A
BLEND OF BASE MODEL OUTPUT AND EXISTING FORECAST NUMBERS.
&&
.AVIATION...
ISSUED AT 623 PM CDT TUE APR 21 2015
SHOWER ACTIVITY WILL BE RATHER SCATTERED IN NATURE TONIGHT...I.E.
SHOULD BE ABLE TO FLY AROUND...SO OPTED FOR JUST A VCTS. WILL
UPGRADE TO A TEMPO GROUP IF STORMS BECOME MORE ORGANIZED/WIDESPREAD.
GUSTY WINDS UP TO 50 MPH WILL BE POSSIBLE IN THE STRONGER STORMS
EARLY THIS EVENING. A FRONTAL BOUNDARY WILL BE ADVANCING FROM THE
NORTH LATER TONIGHT INTO EARLY TOMORROW MORNING. THIS WILL BE FOCUS
FOR MORE SCT CONVECTION AND POSSIBLY LOWER CIGS. AGAIN WILL HANDLE
WITH VCSH FOR NOW. THE FRONT WILL ALSO BRING A WIND SHIFT AROUND TO
THE WEST/NORTHWEST AT AROUND 10 KTS BY AROUND 12Z WED.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
550 PM EDT MON APR 20 2015
.SYNOPSIS...
LOW PRESSURE MEANDERING NORTH OF THE GREAT LAKES WILL DRIVE A COLD
FRONT TOWARD THE REGION TONIGHT. THE FRONT WILL SLOWLY CROSS THE
REGION ON TUESDAY. LOW PRESSURE NORTH OF THE GREAT LAKES WILL
GRADUALLY WEAKEN AS IT DRIFTS SOUTHEAST INTO NEW ENGLAND WEDNESDAY
THROUGH THURSDAY. LOW PRESSURE WILL CONTINUE TO WEAKEN AS IT
MEANDERS NORTH OF NEW ENGLAND FRIDAY THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
UPDATE...HAVE MODIFIED THE GRIDS THRU MORNING BASED ON LATEST
HI-RES MODEL GUIDANCE. EXAMINING RECENT HRRR RUNS HAVE A LARGE
AREA FAVORABLE FOR LIGHTNING DEVELOPMENT MOVING ACROSS THE REGION
ON THE LEADING EDGE OF THE DRY SLOT NEAR MORNING. IN
ADDITION...THE SPC SSEO PRODUCTS ALSO FAVOR A CLUSTER OR LINE OF
TSTMS CROSSING THE FORECAST AREA NEAR 12Z. HAVE INCREASED THE
PROBABILITY FOR THUNDER LATE TONIGHT AND EARLY TUE AS A RESULT.
HAVE ALSO INTRODUCED SOME AREAS OF HEAVY RA TO THE GRIDS NEAR THE
COASTAL FRONT AS WELL AS IN THE EAST SLOPES OF THE MTNS WHERE
STRONG SELY LLJ WILL IMPINGE UPON THE TERRAIN.
THIS LLJ...WHICH IS REALLY JUST GETTING UNDERWAY OVER SRN NEW
ENGLAND PER KBOX 88D...WILL SLOWLY TRAVERSE THE COAST THRU ABOUT
06Z. THIS PUTS HEAVIEST PRECIP IN THE FORECAST AREA BETWEEN ABOUT
00Z AND 06Z. IN ADDITION TO THE HEAVY PRECIP...THIS LLJ MAY INDUCE
SOME STRONG DOWNSLOPE WIND GUSTS NW OF THE WHITE MTNS.
PREVIOUS DISCUSSION...THE FIRST BATCH OF RAIN FROM THIS MORNING
WAS MOVING INTO EASTERN MAINE AS A WARM FRONT LIFTED NORTH INTO
SOUTHERN CANADA. SO FAR ONLY A TENTH TO ABOUT A THIRD OF AN INCH
OF RAIN HAS FALLEN TODAY WITH SOME ISOLATED HIGHER AMOUNTS. THIS
MORNINGS GYX SOUNDING HAD PLENTY OF DRY AIR AND THIS INHIBITED
RAINFALL FROM SPREADING FASTER FOR THE FIRST HALF OF THE DAY.
STEADIER RAINS ARE NOW OVER SOUTHERN NH AND MOVING INTO WESTERN
MAINE. THIS TREND WILL CONTINUE INTO THE EVENING HOURS.
A SECONDARY CYCLONE WILL FORM TONIGHT OVER THE VIRGINIAS AND MOVE
NE ALONG THE ATLANTIC COAST. AS IT DEEPENS IN THE GULF OF MAINE A
LLJ WILL STRENGTHEN AND FEED MOISTURE RICH AIR INTO COASTAL NH AND
MAINE. WARM RAIN PROCESSES AND TRAINING OF CELLS WILL SUPPORT HEAVY
RAIN OVERNIGHT AND INTO TUESDAY. A FLOOD WATCH REMAINS IN EFFECT AS
RAIN COMBINES WITH SNOWMELT TO BRING RIVERS AND STREAMS TO NEAR
BANKFULL.
WINDS WILL BE GUSTY... ESPECIALLY ALONG THE COAST... BUT WE
SHOULD FALL SHORT OF WIND ADVISORY CRITERIA. COASTAL FLOODING WILL
ALSO BE A CONCERN FROM PORTLAND WESTWARD AS EASTERLY FLOW
INCREASES AND COINCIDES WITH THE ASTRONOMICAL HIGH TIDE. MORE
INFORMATION ON THESE HAZARDS BELOW.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
MODERATE TO HEAVY RAIN CONTINUES INTO TUESDAY MORNING. MUCAPE
VALUES INDICATE A SLIGHT CHANCE FOR THUNDERSTORMS BETWEEN 12-18Z
TOMORROW AS THE COLD CORE OF THE UPPER LOW SWINGS BY OVERHEAD.
DRIER AIR PUNCHES IN FROM THE SW MIDDAY TUESDAY. SOME LINGERING
SHOWERS WILL BE POSSIBLE OVER THE MOUNTAINS IN UPSLOPE FLOW. HIGHS
SHOULD WARM INTO THE UPPER 40S NORTH TO LOWER 60S SOUTH.
ADDITIONAL SHOWERS WILL BE POSSIBLE TUESDAY NIGHT WITH CYCLONIC
FLOW ALOFT.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
BROAD UPPER LEVEL CLOSED LOW WILL KEEP WEATHER UNSETTLED
IN THE NORTHEAST THROUGH THE WEEK AND INTO THE WEEKEND AS
IT GRADUALLY SHIFTS EAST. EXPECT SEVERAL LOBES OF ENERGY
TO ROTATE AROUND THIS SYSTEM AND INTO THE NORTHEAST. ANY
MORNING SUN ON WEDNESDAY WILL QUICKLY GIVE WAY TO CLOUDS
AND SHOWERS AS THE FIRST OF THESE DISTURBANCES SWINGS INTO
THE REGION. EXPECT THESE SHOWERS TO PERSIST INTO WEDNESDAY
NIGHT AS A WEAK SURFACE LOW SLOWLY CROSSES THE REGION.
STEADIER PRECIP WILL COME TO AN END AS LOW PRESSURE LIFTS INTO
THE MARITIMES ON THURSDAY. EXPECT CLOUDY SKIES AND SCATTERED
SHOWERS THURSDAY THROUGH FRIDAY WITH HIGHS IN THE 40S TO LOWER
50S.
SHOWER ACTIVITY WILL DIMINISH OVER THE WEEKEND BUT SKIES WILL
REMAIN MOSTLY CLOUDY WITH RAIN OR SNOW SHOWERS POSSIBLE MAINLY IN
NORTHERN ZONES.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
SHORT TERM...MVFR WILL DETERIORATE TO LIFR AND IFR SHORTLY AS
HEAVIER RAIN MOVES IN. RAIN MAY BE LIGHTER AT KHIE WHERE WE WILL
SEE THE RAIN SHADOW EFFECT. ALSO SOME SNOW MAY MIX IN LATE IN THE
NORTH. EAST WINDS MAY GUST TO 35 KTS AT TIMES. SOME IMPROVEMENT BY
MID MORNING TUESDAY AS RAIN MOVES EAST.
LONG TERM...AREAS OF MVFR CEILINGS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
SHORT TERM...EASTERLY WINDS AND SEAS CONTINUE TO BUILD TONIGHT. A
GALE WARNING REMAINS IN EFFECT THROUGH 2 PM TUESDAY. WINDS WILL
DECREASE BUT A SCA WILL LIKELY BE NEEDED FOR WAVES THROUGH
WEDNESDAY EVENING.
LONG TERM...SCA`S MAY BE NEEDED THURSDAY AND FRIDAY.
&&
.FIRE WEATHER...
ONSHORE FLOW TODAY BRINGS MORE MOISTURE AND EVENTUALLY RAIN TO
THE AREA. A SOAKING RAIN IS EXPECTED LATE TODAY AND TUESDAY.
&&
.HYDROLOGY...
A WIDESPREAD 1 TO 2 INCHES OF RAIN IS EXPECTED FROM THIS
AFTERNOON THROUGH TUESDAY. HOWEVER...GIVEN STRONG MOISTURE
INFLOW...LOCALIZED AMOUNTS OF UP TO 3 INCHES COULD OCCUR. THIS
WOULD LEAD TO FLOODING PROBLEMS...ESPECIALLY IN AREAS WHERE SNOW
MELT IS STILL OCCURRING. A FLOOD WATCH REMAINS IN EFFECT.
&&
.TIDES/COASTAL FLOODING...
AS EASTERLY WINDS CONTINUE TO INCREASE...SEAS WILL BUILD 10 TO 15
FT. HIGH TIDE ON APRIL 21 IS AT 1:21 AM WITH A PREDICTED HEIGHT OF
11.4 FT MLLW. HOWEVER...ONSHORE WINDS ARE EXPECTED TO RESULT IN A 1-
2 FT STORM SURGE. THE COMBINATION OF WIND, WAVES AND HIGH TIDE WILL
RESULT IN OVERWASH AND POSSIBLE INUNDATION FOR THE BEACHES OF THE
SOUTH COAST OF MAINE AND NEW HAMPSHIRE. FARTHER DOWNEAST THE
EASTERLY WIND DIRECTION IS LESS FAVORABLE FOR ONSHORE INUNDATION.
EVEN SO THE SIGNIFICANT WAVES MAY RESULT IN SOME COASTAL FLOODING
AND A COASTAL FLOOD ADVISORY HAS BEEN POSTED THERE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR MEZ007>009-012>014-
018>028.
COASTAL FLOOD ADVISORY FROM 11 PM THIS EVENING TO 3 AM EDT
TUESDAY FOR MEZ025>028.
COASTAL FLOOD WARNING FROM 11 PM THIS EVENING TO 3 AM EDT
TUESDAY FOR MEZ023-024.
NH...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR NHZ002>015.
COASTAL FLOOD WARNING FROM 11 PM THIS EVENING TO 3 AM EDT
TUESDAY FOR NHZ014.
MARINE...GALE WARNING UNTIL 2 PM EDT TUESDAY FOR ANZ150>154.
&&
$$
NEAR TERM...LEGRO
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
303 PM EDT MON APR 20 2015
.SYNOPSIS...
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL ACCOMPANY A
COLD FRONT LATE TODAY AND THIS EVENING. THE COLD FRONT WILL CROSS
THE AREA TONIGHT. HIGH PRESSURE BUILDS BACK IN FROM THE SOUTHWEST
ON TUESDAY. ANOTHER COLD FRONT CROSSES THE AREA WEDNESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SEVERE THUNDERSTORM WATCH 89 HAS BEEN ISSUED FOR PORTIONS OF THE
ERN VA PIEDMONT...CNTRL VA AND NRN VA UNTIL 10 PM.
AS OF NOON...
LATEST WX ANALYSIS DEPICTS WARM FRONT JUST NORTH OF
THE LOCAL AREA WITH A TRAILING COLD FRONT EXTENDING FROM ~985MB
LOW PRESSURE OVER THE GREAT LAKES SWD TO THE LOWER MS VALLEY.
ALOFT...UPPER LOW HAS LOCATED OVER THE UPPER MIDWEST WITH TROUGH
AXIS EXTENDING SWD ALONG THE MS VALLEY. LATEST REGIONAL RADAR
MOSAIC DEPICTS LAST NIGHTS SHOWERS WELL OFFSHORE WITH DRY
CONDITIONS OVER MUCH OF THE MID-ATLANTIC REGION. SKIES AVG MOSTLY
CLOUDY.
FOR TODAY...SFC LOW LIFTS NWD INTO SRN ONTARIO THIS AFTERNOON AS
THE COLD FRONT APPROACHES THE LOCAL AREA. SEVERAL PERTURBATIONS IN
INCREASING SWLY FLOW ALOFT WILL LIFT TOWARD THE REGION. THE
AIRMASS OVER THE LOCAL AREA WILL BECOME INCREASINGLY WARM/MOIST
AND UNSTABLE...ESPECIALLY WITH A FEW HOLES IN THE CLOUD COVER
EXPECTED THIS AFTERNOON. THETA E ADVECTION ALONG WITH TEMPS IN THE
LOW-MID 80S AND DEWPOINTS AROUND 60 WILL RESULT IN A MARGINALLY
UNSTABLE AIRMASS...WITH MLCAPE VALUES PER RAP GUIDANCE IN THE
1000-1500 J/KG RANGE. MODELS ALSO INDICATE VERY LITTLE MLCIN.
WHILE THERE WILL BE VERY LITTLE INHIBITION THIS AFTERNOON...EXPECT
PRECIP TO STAY TIED TO THE FRONT/CONVERGENCE ZONE. EXPECT
MOISTURE ADVECTION TO RAMP UP IN ADVANCE OF THE FRONT...WITH
PRECIP WATERS APPROACHING 1-1.25 INCHES.
COLD FRONT REACHES THE ERN VA PIEDMONT MID-LATE AFTERNOON. HI-RES
GUIDANCE INDICATING VERY LITTLE CONVECTION ALONG THE FRONT AS IT
CROSSES THE CNTRL APPALACHIANS...BUT ONCE THE FRONT REACHES THE
AIRMASS OVER THE PIEDMONT...MODELS INDICATE INITIATION AROUND
3-5PM THIS AFTERNOON OVER THE PIEDMONT. MODE EXPECTED TO START
OFF AS DISCRETE CELLS...BUT 30-40 KT OF EFFECTIVE BULK SHEAR WILL
TRANSITION TO A LINE FROM THE PIEDMONT INTO CNTRL VIRGINIA. QUICK
W-SW MID LEVEL FLOW WILL PUSH STORMS QUICKLY TO THE E-NE...WITH
THE BEST CHANCES REMAINING ALONG THE INSTABILITY AXIS FROM THE
PIEDMONT INTO CNTRL VA. STORMS PROGGED TO REACH CNTRL VA LATE
TODAY-EARLY THIS EVENING...AND THEN POINTS EWD THRU THE EVENING.
WHILE MORE INSTABILITY IS PROGGED ACROSS THE SE...EVENING TIMING
AND DECREASING SHEAR IS NOT FAVORABLE TO MAINTAIN LINE SEGMENTS
INTO THAT AREA. HI-RES GUIDANCE ALSO BACKS THIS UP. HAVE INCREASED
POPS TO LIKELY ACROSS THE PIEDMONT NEWD TO THE MD ERN SHORE...WITH
HIGH END CHANCE SOUTH AND EAST. DAMAGING WIND GUSTS AND LARGE HAIL
ARE POSSIBLE THANKS TO DEEP INSTABILITY...FAVORABLE LAPSE RATES
AND A RELATIVELY LOW FREEZING LEVEL. TORNADO RISK REMAINS LOW
THANKS TO GOOD MIXING AND HIGH LCL HEIGHTS. THE BEST RISK FOR
SEVERE WEATHER WILL BE ACROSS THE LIKELY POP AREA WITH ISOLATED
STRONG TO SEVERE STORMS STILL POSSIBLE OVER THE SE. BRIEF HEAVY
RAINFALL ALSO EXPECTED...BUT MOVEMENT WILL LIMIT ANY FLOODING
POTENTIAL.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
A COLD FRONT CROSSES THE FA TONIGHT WITH CHC POPS...THEN
DRYING/COOLER WESTERLY FLOW TAKING OVR INTO TUE. PARTLY/MOSTLY
SUNNY TUE WITH HIGH TEMPS IN THE UPR 60S TO NR 70 AT THE
COAST...AND LOW/MID 70S ELSEWHERE.
HIGH PRES MOVES TO NR THE SE CONUS COAST BY WED...PROVIDING WSW
FLOW AND CONTINUING MILD WX. A WEAK TROUGH WILL BE APPROACHING
FROM THE WNW...WHICH SHOULD RESULT IN INCREASING CLOUDS AND THE
POSSIBILITY OF AFTERNOON SHOWERS (ISOLD TSTMS). LOW TEMPS TUE NGT
MID 40S WEST AND NORTH TO LOW 50S SE. HIGH TEMPS WED IN THE
LOW/MID 70S...EXCEPT 60S AT THE IMMEDIATE COAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
BROAD CYCLONIC FLOW PREVAILS THRU THE EXTENDED PERIOD AS UPPER
CLOSED LOW REMAINS IN VIC OF THE GREAT LAKES AND NEW ENGLAND. TO
BEGIN THE PERIOD...FAST MOVING COLD FRONT CROSSES THE REGION LATE
WEDS NIGHT-EARLY THURS MORNING. GFS CONTINUES TO REMAIN ON THE
SLOWER SIDE OF MODEL GUIDANCE WRT FRONTAL PASSAGE...WITH THE ECMWF
QUICKER. BASED ON WLY FLOW ALOFT AND HIGH PRESSURE BACK OVER THE
MIDWEST...OPTED TO REINTRODUCE SLIGHT CHANCE POPS WEDS NIGHT OVER
THE NRN AND NERN ZONES AND THEN THURS SOUTH AND EAST OF
RICHMOND...TRENDING SLIGHTLY TOWARD THE SLOWER GFS. HIGHS THURS
AROUND NORMAL...LOW-MID 60S. THEREAFTER...COOL HIGH PRESSURE BUILDS
SWD FROM THE CANADIAN PRAIRIES INTO THE MIDWEST...EXTENDING INTO THE
MID-ATLANTIC REGION FRI. HIGHS FRI GENERALLY IN THE UPPER 50S NE TO
MID 60S SE UNDER A PARTLY CLOUDY SKY AND NWLY WINDS. SRN STREAM
SHORTWAVE PROGGED TO LIFT INTO THE MIDWEST FRI NIGHT-SAT WITH
ASSOCIATED SFC LOW FORECAST TO PROGRESS EWD ALONG A STATIONARY
BOUNDARY OVER THE GULF STATES SAT. MOISTURE RETURNS SAT TO GO ALONG
WITH OVERRUNNING AND WEAK PERTURBATIONS ALOFT. INCREASED POPS TO
SLIGHT CHANCE N TO CHANCE S. HIGHS SAT GENERALLY AROUND 60 ACROSS
THE REGION. SFC LOW MOVES OFF THE CAROLINA COAST SAT NIGHT...WITH
ANY REMAINING PRECIP EXPECTED ACROSS THE SE LOCAL AREA. HIGH
PRESSURE RETURNS SUN...BUT COOL CONDITIONS PERSIST WITH HIGHS IN THE
UPPER 50S NE TO LOW 60S SE.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
THE FRONTAL RAINBAND IS MOVING OFFSHORE THIS MORNING. CONDITIONS
ARE IMPROVING AND SHOULD CONTINUE THROUGH THE MORNING. CLOUD
COVER ACTUALLY SCATTERING OUT BY THIS AFTERNOON...ALONG WITH A
GUSTY SW WIND. A SECONDARY IMPULSE TRACKS ACROSS THE REGION LATE
THIS AFTERNOON AND EVENING BRINGING A CHC OF SHOWERS/TSTMS. ANY
TSTMS COULD CONTAIN STRONG WIND GUSTS. A COLD FRONT THEN MOVES OFF
THE COAST LATER TONIGHT...WITH HIGH PRESSURE BUILDING INTO THE
REGION TUESDAY...BEFORE MOVING OFFSHORE WEDNESDAY. A COLD FRONT
CROSSES THE AREA WEDNESDAY NIGHT WITH A SLIGHT CHC OF SHOWERS.
HIGH PRESSURE RETURNS THURSDAY AND FRIDAY.
&&
.MARINE...
LOW PRESSURE IS LIFTING NNE OVER THE GREAT LAKES EARLY THIS
MORNING...WITH SECONDARY LOW PRESSURE OVER THE MID ATLANTIC. 3 TO
5 FT WAVES IN THE MOUTH OF THE BAY WILL CONTINUE THROUGH THE
AFTN. SEAS HAVE RISEN TO 5-8FT...AND WILL LIKELY REACH 6-9FT EARLY
TODAY...BEFORE SLOWLY SUBSIDING LATER TODAY THROUGH TUESDAY. A
FRONTAL BOUNDARY IS PRESENTLY CROSSING THE AREA AND SHOULD MOVE
OFFSHORE BY 12Z (15Z FARTHER NE). EXPECT THE WIND TO BECOME
SOUTHERLY BEHIND THE FRONT WITH SPEEDS RELAXING TO 10-15KT.
INHERITED SCA FLAGS REMAIN AS IS. HOWEVER...THE RIVERS COULD
POTENTIALLY END EARLIER THAN THE CURRENT 10 AM TIME. THIS WILL BE
RECONSIDERED AT THE 11Z/7 AM UPDATE. OTHERWISE...A COLD FRONT
APPROACHES FROM THE W THIS AFTERNOON/EVENING...AND MOVES ACROSS
THE COAST LATE TONIGHT. THIS FRONT IS EXPECTED TO TRIGGER
SHOWERS/TSTMS...WHICH WILL HAVE THE POTENTIAL OF PRODUCING STRONG
WIND GUSTS. HIGH PRESSURE BUILDS ACROSS THE SOUTHEAST TUESDAY AND
WEDNESDAY AS LOW PRESSURE LINGERS OVER THE GREAT LAKES. A WEAK
COLD FRONT CROSSES THE REGION WEDNESDAY NIGHT WITH HIGH PRESSURE
RETURNING THURSDAY AND FRIDAY.
&&
.HYDROLOGY...
AVG QPF 0.75-2.00"...LOCALLY UP TO 2.50" OVR MOST OF THE RIVER
BASINS WILL RESULT IN RIVER LVLS TO PSBLY RISE TO 1/2-NR FULL
BANKFULL TUE INTO WED.
&&
.TIDES/COASTAL FLOODING...
SOUTHERLY FLOW TODAY INTO THIS EVENING WILL HELP MAINTAIN ~1.0 FT
ANOMALIES IN THE MIDDLE BAY THROUGH TONIGHT. TIDAL ANOMALIES WILL
BEGIN TO SUBSIDE TUESDAY AS THE FLOW BECOMES OFFSHORE. NO
STATEMENTS HAVE BEEN ISSUED AT THIS TIME...BUT BISHOPS HEAD WILL
COME CLOSE TO THEIR 3.25FT MINOR THRESHOLD.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ634.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT TUESDAY FOR ANZ654-656-658.
SMALL CRAFT ADVISORY UNTIL 1 PM EDT TUESDAY FOR ANZ650-652.
&&
$$
SYNOPSIS...JDM
NEAR TERM...SAM
SHORT TERM...ALB/JDM
LONG TERM...SAM
AVIATION...AJZ
MARINE...AJZ
HYDROLOGY...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1206 PM EDT MON APR 20 2015
.SYNOPSIS...
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL ACCOMPANY A
COLD FRONT LATE TODAY AND THIS EVENING. THE COLD FRONT WILL CROSS
THE AREA TONIGHT. HIGH PRESSURE BUILDS BACK IN FROM THE SOUTHWEST
ON TUESDAY. ANOTHER COLD FRONT CROSSES THE AREA WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST WX ANALYSIS DEPICTS WARM FRONT JUST NORTH OF THE LOCAL AREA
WITH A TRAILING COLD FRONT EXTENDING FROM ~985MB LOW PRESSURE
OVER THE GREAT LAKES SWD TO THE LOWER MS VALLEY. ALOFT...UPPER LOW
HAS LOCATED OVER THE UPPER MIDWEST WITH TROUGH AXIS EXTENDING SWD
ALONG THE MS VALLEY. LATEST REGIONAL RADAR MOSAIC DEPICTS LAST
NIGHTS SHOWERS WELL OFFSHORE WITH DRY CONDITIONS OVER MUCH OF THE
MID-ATLANTIC REGION. SKIES AVG MOSTLY CLOUDY.
FOR TODAY...SFC LOW LIFTS NWD INTO SRN ONTARIO THIS AFTERNOON AS
THE COLD FRONT APPROACHES THE LOCAL AREA. SEVERAL PERTURBATIONS IN
INCREASING SWLY FLOW ALOFT WILL LIFT TOWARD THE REGION. THE
AIRMASS OVER THE LOCAL AREA WILL BECOME INCREASINGLY WARM/MOIST
AND UNSTABLE...ESPECIALLY WITH A FEW HOLES IN THE CLOUD COVER
EXPECTED THIS AFTERNOON. THETA E ADVECTION ALONG WITH TEMPS IN THE
LOW-MID 80S AND DEWPOINTS AROUND 60 WILL RESULT IN A MARGINALLY
UNSTABLE AIRMASS...WITH MLCAPE VALUES PER RAP GUIDANCE IN THE
1000-1500 J/KG RANGE. MODELS ALSO INDICATE VERY LITTLE MLCIN.
WHILE THERE WILL BE VERY LITTLE INHIBITION THIS AFTERNOON...EXPECT
PRECIP TO STAY TIED TO THE FRONT/CONVERGENCE ZONE. EXPECT
MOISTURE ADVECTION TO RAMP UP IN ADVANCE OF THE FRONT...WITH
PRECIP WATERS APPROACHING 1-1.25 INCHES.
COLD FRONT REACHES THE ERN VA PIEDMONT MID-LATE AFTERNOON. HI-RES
GUIDANCE INDICATING VERY LITTLE CONVECTION ALONG THE FRONT AS IT
CROSSES THE CNTRL APPALACHIANS...BUT ONCE THE FRONT REACHES THE
AIRMASS OVER THE PIEDMONT...MODELS INDICATE INITIATION AROUND
3-5PM THIS AFTERNOON OVER THE PIEDMONT. MODE EXPECTED TO START
OFF AS DISCRETE CELLS...BUT 30-40 KT OF EFFECTIVE BULK SHEAR WILL
TRANSITION TO A LINE FROM THE PIEDMONT INTO CNTRL VIRGINIA. QUICK
W-SW MID LEVEL FLOW WILL PUSH STORMS QUICKLY TO THE E-NE...WITH
THE BEST CHANCES REMAINING ALONG THE INSTABILITY AXIS FROM THE
PIEDMONT INTO CNTRL VA. STORMS PROGGED TO REACH CNTRL VA LATE
TODAY-EARLY THIS EVENING...AND THEN POINTS EWD THRU THE EVENING.
WHILE MORE INSTABILITY IS PROGGED ACROSS THE SE...EVENING TIMING
AND DECREASING SHEAR IS NOT FAVORABLE TO MAINTAIN LINE SEGMENTS
INTO THAT AREA. HI-RES GUIDANCE ALSO BACKS THIS UP. HAVE INCREASED
POPS TO LIKELY ACROSS THE PIEDMONT NEWD TO THE MD ERN SHORE...WITH
HIGH END CHANCE SOUTH AND EAST. DAMAGING WIND GUSTS AND LARGE HAIL
ARE POSSIBLE THANKS TO DEEP INSTABILITY...FAVORABLE LAPSE RATES
AND A RELATIVELY LOW FREEZING LEVEL. TORNADO RISK REMAINS LOW
THANKS TO GOOD MIXING AND HIGH LCL HEIGHTS. THE BEST RISK FOR
SEVERE WEATHER WILL BE ACROSS THE LIKELY POP AREA WITH ISOLATED
STRONG TO SEVERE STORMS STILL POSSIBLE OVER THE SE. BRIEF HEAVY
RAINFALL ALSO EXPECTED...BUT MOVEMENT WILL LIMIT ANY FLOODING
POTENTIAL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
A COLD FRONT CROSSES THE FA TONIGHT WITH CHC POPS...THEN
DRYING/COOLER WESTERLY FLOW TAKING OVR INTO TUE. PARTLY/MOSTLY
SUNNY TUE WITH HIGH TEMPS IN THE UPR 60S TO NR 70 AT THE
COAST...AND LOW/MID 70S ELSEWHERE.
HIGH PRES MOVES TO NR THE SE CONUS COAST BY WED...PROVIDING WSW
FLOW AND CONTINUING MILD WX. A WEAK TROUGH WILL BE APPROACHING
FROM THE WNW...WHICH SHOULD RESULT IN INCREASING CLOUDS AND THE
POSSIBILITY OF AFTERNOON SHOWERS (ISOLD TSTMS). LOW TEMPS TUE NGT
MID 40S WEST AND NORTH TO LOW 50S SE. HIGH TEMPS WED IN THE
LOW/MID 70S...EXCEPT 60S AT THE IMMEDIATE COAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
BROAD CYCLONIC FLOW PREVAILS THRU THE EXTENDED PERIOD AS UPPER
CLOSED LOW REMAINS IN VIC OF THE GREAT LAKES AND NEW ENGLAND. TO
BEGIN THE PERIOD...FAST MOVING COLD FRONT CROSSES THE REGION LATE
WEDS NIGHT-EARLY THURS MORNING. GFS CONTINUES TO REMAIN ON THE
SLOWER SIDE OF MODEL GUIDANCE WRT FRONTAL PASSAGE...WITH THE ECMWF
QUICKER. BASED ON WLY FLOW ALOFT AND HIGH PRESSURE BACK OVER THE
MIDWEST...OPTED TO REINTRODUCE SLIGHT CHANCE POPS WEDS NIGHT OVER
THE NRN AND NERN ZONES AND THEN THURS SOUTH AND EAST OF
RICHMOND...TRENDING SLIGHTLY TOWARD THE SLOWER GFS. HIGHS THURS
AROUND NORMAL...LOW-MID 60S. THEREAFTER...COOL HIGH PRESSURE BUILDS
SWD FROM THE CANADIAN PRAIRIES INTO THE MIDWEST...EXTENDING INTO THE
MID-ATLANTIC REGION FRI. HIGHS FRI GENERALLY IN THE UPPER 50S NE TO
MID 60S SE UNDER A PARTLY CLOUDY SKY AND NWLY WINDS. SRN STREAM
SHORTWAVE PROGGED TO LIFT INTO THE MIDWEST FRI NIGHT-SAT WITH
ASSOCIATED SFC LOW FORECAST TO PROGRESS EWD ALONG A STATIONARY
BOUNDARY OVER THE GULF STATES SAT. MOISTURE RETURNS SAT TO GO ALONG
WITH OVERRUNNING AND WEAK PERTURBATIONS ALOFT. INCREASED POPS TO
SLIGHT CHANCE N TO CHANCE S. HIGHS SAT GENERALLY AROUND 60 ACROSS
THE REGION. SFC LOW MOVES OFF THE CAROLINA COAST SAT NIGHT...WITH
ANY REMAINING PRECIP EXPECTED ACROSS THE SE LOCAL AREA. HIGH
PRESSURE RETURNS SUN...BUT COOL CONDITIONS PERSIST WITH HIGHS IN THE
UPPER 50S NE TO LOW 60S SE.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
THE FRONTAL RAINBAND IS MOVING OFFSHORE THIS MORNING. CONDITIONS
ARE IMPROVING AND SHOULD CONTINUE THROUGH THE MORNING. CLOUD
COVER ACTUALLY SCATTERING OUT BY THIS AFTERNOON...ALONG WITH A
GUSTY SW WIND. A SECONDARY IMPULSE TRACKS ACROSS THE REGION LATE
THIS AFTERNOON AND EVENING BRINGING A CHC OF SHOWERS/TSTMS. ANY
TSTMS COULD CONTAIN STRONG WIND GUSTS. A COLD FRONT THEN MOVES OFF
THE COAST LATER TONIGHT...WITH HIGH PRESSURE BUILDING INTO THE
REGION TUESDAY...BEFORE MOVING OFFSHORE WEDNESDAY. A COLD FRONT
CROSSES THE AREA WEDNESDAY NIGHT WITH A SLIGHT CHC OF SHOWERS.
HIGH PRESSURE RETURNS THURSDAY AND FRIDAY.
&&
.MARINE...
LOW PRESSURE IS LIFTING NNE OVER THE GREAT LAKES EARLY THIS
MORNING...WITH SECONDARY LOW PRESSURE OVER THE MID ATLANTIC. 3 TO
5 FT WAVES IN THE MOUTH OF THE BAY WILL CONTINUE THROUGH THE
AFTN. SEAS HAVE RISEN TO 5-8FT...AND WILL LIKELY REACH 6-9FT EARLY
TODAY...BEFORE SLOWLY SUBSIDING LATER TODAY THROUGH TUESDAY. A
FRONTAL BOUNDARY IS PRESENTLY CROSSING THE AREA AND SHOULD MOVE
OFFSHORE BY 12Z (15Z FARTHER NE). EXPECT THE WIND TO BECOME
SOUTHERLY BEHIND THE FRONT WITH SPEEDS RELAXING TO 10-15KT.
INHERITED SCA FLAGS REMAIN AS IS. HOWEVER...THE RIVERS COULD
POTENTIALLY END EARLIER THAN THE CURRENT 10 AM TIME. THIS WILL BE
RECONSIDERED AT THE 11Z/7 AM UPDATE. OTHERWISE...A COLD FRONT
APPROACHES FROM THE W THIS AFTERNOON/EVENING...AND MOVES ACROSS
THE COAST LATE TONIGHT. THIS FRONT IS EXPECTED TO TRIGGER
SHOWERS/TSTMS...WHICH WILL HAVE THE POTENTIAL OF PRODUCING STRONG
WIND GUSTS. HIGH PRESSURE BUILDS ACROSS THE SOUTHEAST TUESDAY AND
WEDNESDAY AS LOW PRESSURE LINGERS OVER THE GREAT LAKES. A WEAK
COLD FRONT CROSSES THE REGION WEDNESDAY NIGHT WITH HIGH PRESSURE
RETURNING THURSDAY AND FRIDAY.
&&
.HYDROLOGY...
AVG QPF 0.75-2.00"...LOCALLY UP TO 2.50" OVR MOST OF THE RIVER
BASINS WILL RESULT IN RIVER LVLS TO PSBLY RISE TO 1/2-NR FULL
BANKFULL TUE INTO WED.
&&
.TIDES/COASTAL FLOODING...
SOUTHERLY FLOW TODAY INTO THIS EVENING WILL HELP MAINTAIN ~1.0 FT
ANOMALIES IN THE MIDDLE BAY THROUGH TONIGHT. TIDAL ANOMALIES WILL
BEGIN TO SUBSIDE TUESDAY AS THE FLOW BECOMES OFFSHORE. NO
STATEMENTS HAVE BEEN ISSUED AT THIS TIME...BUT BISHOPS HEAD WILL
COME CLOSE TO THEIR 3.25FT MINOR THRESHOLD.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ634.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT TUESDAY FOR ANZ654-656-658.
SMALL CRAFT ADVISORY UNTIL 1 PM EDT TUESDAY FOR ANZ650-652.
&&
$$
SYNOPSIS...JDM
NEAR TERM...JDM/SAM
SHORT TERM...ALB/JDM
LONG TERM...SAM
AVIATION...AJZ
MARINE...AJZ
HYDROLOGY...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1115 PM EDT TUE APR 21 2015
.UPDATE...
ISSUED AT 1114 PM EDT TUE APR 21 2015
PREVIOUS SHORT TERM DISCUSSION SPELLED OUT THE SITUATION QUITE WELL
FOR OVERNIGHT INTO WED. AFTER CONSIDERING THE DEEP MOISTURE ON 00Z
KINL/CWPL SOUNDINGS...850MB TEMPS FALLING AT LEAST ANOTHER 2C
OVERNIGHT AND CONTINUED CYCLONIC FLOW...FEEL ADVY ACCUMULATIONS ARE
LIKELY TO OCCUR OVER A DECENT AREA OF GOGEBIC/ONTONAGON COUNTIES...
IN PARTICULAR THE HIGH TERRAIN. WOULD NOT BE SURPRISED TO SEE A FEW
SPOTS IN THE HIGH TERRAIN TOP 5 INCHES BY NOON WED. PROBABLY COULD
HAVE EXTENDED ADVY N AND E THRU THE KEWEENAW AND INTO BARAGA COUNTY
AS AIR MASS PASSING OVER THE LAKE WILL BE A LITTLE COLDER THAN DOWN
TOWARD KIWD. RECENT RADAR TRENDS ARE ALSO A CONCERN WITH INCREASING
COVERAGE AND INTENSITY OF SNOW IN THAT AREA. ALSO BUMPED UP SNOW
ACCUMLATIONS INTO THE ERN FCST AREA...E OF MARQUETTE AS 850MB
THERMAL TROF WITH TEMPS AS LOW AS -14C WILL BE AIMING SE ACROSS THE
LAKE AND INTO THAT AREA WED MORNING. HAVE AMOUNTS UP TO AROUND 3
INCHES IN THAT AREA BY LATE WED MORNING...BUT THAT COULD END UP
BEING TOO CONSERVATIVE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 352 PM EDT TUE APR 21 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO OVER
THE UPR LKS DOWNSTREAM OF HI AMPLITUDE UPR RDG OVER WRN NAMERICA.
COMBINATION OF DEEP CYC FLOW W TO NW FLOW AND INSTABILITY ENHANCED
BY DAYTIME HEATING UNDER ACCOMAPANYING THERMAL TROF /12Z H5 TEMP AT
GRB WAS -31C/ AND DEEP MSTR SHOWN ON THE 12Z RAOBS IS RESULTING IN
SCT-NMRS SN SHOWERS THAT ARE MIXED WITH RA IN THE WARMER LOCATIONS.
BUT COLDER CLD TOP TEMPS/MORE WIDESRPEAD SN SHOWERS ARE CONFINED
MAINLY TO NW ONTARIO/FAR NRN MN IN AREA WHERE MODELS INDICATE DEEP
QVECTOR CNVGC.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS AND POTENTIAL SN
ACCUMS ASSOCIATED WITH DEEP CYC...MOIST NW FLOW ARND SLOW MOVING
CLOSED LO TO THE NE OF UPR MI.
CLOSED LO CENTERED OVER ERN LK SUP THIS AFTN IS FCST TO DRIFT SLOWLY
TO THE NE AND TO JUST S OF JAMES BAY ON WED. ALTHOUGH ACCOMPANYING
DEEP LYR QVECTOR CNVGC THAT IS SUPPORTING COLDER CLD TOPS TO THE NW
IS FCST TO REMAIN TO THE N OF UPR MI...PERSISTENT MOIST...CYC NW
FLOW ARND THIS FEATURE WL MAINTAIN AT LEAST CHC POPS OVER THE CWA
THRU WED...WITH THE LOWER POPS GENERALLY OVER THE SCENTRAL AND THE
HIER POPS OVER THE HIER TERRAIN OF THE NW WITH UPSLOPE WIND
COMPONENT. BUT LOSS OF DAYTIME HEATING TNGT WL CAUSE THE
CHARACTER OF THE SHOWER PATTERN TO TRANSITIONS FM ONE THAT SUPPORTS
THE HIER POPS OVER THE INTERIOR THIS AFTN TO A MORE WINTRY LES
LOOK TNGT. IN FACT...THE NW FLOW IS PROGGED TO ADVECT H85 TEMPS AS
LO AS -13 TO -14C OVER THE KEWEENAW BY 12Z WED...TEMPS LO ENUF TO
SUPPORT LES AND INCRS SN/WATER RATIOS ONCE THE EFFECT OF DAYTIME
INSOLATION HAS FADED. OVER THE HIER TERRAIN OF THE W...THERE WL
LIKELY BE SEVERAL INCHES OF WET SN ACCUM TNGT INTO WED MRNG EVEN IN
THE ABSENCE OF SGNFT LARGER SCALE FORCING. OPTED TO ISSUE AN SPS
TO ALERT THE PUBLIC TO THE POTENTIAL OF SOME SLUSHY SN ACCUMS ON
ROADS LATER THIS EVNG INTO WED MRNG. DAYTIME HEATING ON WED WL
BRING ABOUT A RETURN TO A MORE LAND BASED INSTABILITY SHOWER
PATTERN. BUT SOMEWHAT HIER HGTS/SHARPENING MID LVL INVRN FARTHER FM
THE SLOWLY DEPARTING CLOSED LO THAT RESTRICTS DESTABILIZATION WL
TEND TO LIMIT COVERAGE/INTENSITY OF THE SHOWERS AS COMPARED TO TODAY.
ALTHOUGH H85 TEMPS ARE FCST TO MODERATE TO -10C TO -12C...MAX TEMPS
ON WED WL HOLD IN THE 30S EXPECT WHERE SOME DOWNSLOPE WARMING AIDS
DIURNAL TEMP RECOVERY INTO THE LO 40S OVER THE SCENTRAL. THERE COULD
BE SOME RECORD LO MAX TEMPS ON WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 PM EDT TUE APR 21 2015
THE UPPER LOW THAT IS CURRENTLY AFFECTING THE AREA WILL SHIFT EAST
INTO THE CANADIAN MARITIMES SHORTLY AFTER THE START OF THE LONG TERM
PERIOD. THIS WILL LEAVE THE AREA BETWEEN THAT UPPER LOW AND AN UPPER
RIDGE IN THE CENTRAL/SOUTHERN PLAINS. THUS...THE AREA WILL BE UNDER
NORTHWESTERLY FLOW ALOFT FOR MOST DAYS THROUGH THE UPCOMING WEEKEND.
WITH A SURFACE RIDGE STRETCHING SOUTH FROM A HIGH IN NORTHERN CANADA
MOVING INTO THE AREA BY FRIDAY AND FRIDAY NIGHT...EXPECT DRIER AIR
TO GRADUALLY MOVE INTO THE REGION AND DIMINISH THE PRECIPITATION
POTENTIAL AND LEAD TO A DRY WEEKEND (ALTHOUGH THERE ARE HINTS OF A
WEAK DISTURBANCE BRINGING AN ISOLATED SHOWER TO THE FAR WESTERN U.P.
LATE FRIDAY NIGHT INTO SATURDAY MORNING). WITH THE MAIN UPPER LOW
SHIFTING EAST...TEMPERATURES WILL SLOWLY WARM BUT STILL STAY BELOW
NORMAL FOR LATE APRIL (AIDED BY THE LIGHT NORTHERLY FLOW OFF LAKE
SUPERIOR).
HEADING INTO NEXT WEEK...THE UPPER LOW CURRENTLY OVER THE GULF OF
ALASKA WILL MOVE INTO THE PACIFIC NORTHWEST OVER THE NEXT 24-48HRS
AND THEN INTO THE CENTRAL CONUS ON MONDAY. AS THE WAVE CONTINUES
EAST...IT WILL INTERACT WITH THE UPPER LOW NEAR THE CANADIAN
MARITIMES AND RE-ESTABLISH THE UPPER TROUGH OVER THE EASTERN CONUS.
THIS WILL KEEP BELOW NORMAL TEMPERATURES IN PLACE INTO NEXT WEEK AND
POSSIBLY LEAD TO SOME SHOWERS AROUND THE GREAT LAKES REGION.
OVERALL...FAIRLY COOL AND QUIET END TO APRIL WITH NO HAZARDOUS
WEATHER EXPECTED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 750 PM EDT TUE APR 21 2015
AS DEEP MOISTURE LINGERS AND COLDER AIR ARRIVES TONIGHT...SHSN WILL
TEND TO INCREASE IN FREQUENCY AT KIWD/KCMX WITH USPLOPE NW WIND
COMPONENT OFF LAKE SUPERIOR. EXPECT A TREND TO PREVAILING IFR BY
LATE EVENING...THEN CONTINUING THRU MID MORNING WED. TYPICAL FOR
SHSN...THERE WILL LIKELY BE FLUCTUATION WITH SOME BRIEF PERIODS OF
LIFR AND MVFR. INTO WED AFTN...EXPECT IMPROVEMENT TO MVFR AS SHSN
INTENSITY DIMINISHES. DOWNSLOPE NATURE OF THE NW FLOW WILL LIMIT THE
POTENTIAL FOR LOWER VIS/CIG AT KSAW...BUT MVFR CIGS SHOULD BECOME
PREVAILING MID TO LATE EVENING WITH RATHER MOIST LOW-LEVELS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 305 PM EDT TUE APR 21 2015
NORTHWESTERLY WINDS UP TO 30 KNOTS WILL CONTINUE OVER LAKE SUPERIOR
THROUGH THURSDAY MORNING. THERE COULD BE A FEW PERIODS OF GALE
FORCE GUSTS TO 35KTS LATE TONIGHT INTO WEDNESDAY...BUT THEY
SHOULDN/T BE WIDESPREAD. HIGH PRESSURE WILL BEGIN TO BUILD INTO
WESTERN LAKE SUPERIOR THURSDAY AFTERNOON/NIGHT AND LEAD TO
GRADUALLY DIMINISHING WINDS INTO FRIDAY. LIGHT NORTHERLY WINDS UP
TO 15KTS ARE EXPECTED THIS WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL NOON EDT /11 AM CDT/ WEDNESDAY FOR
MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
750 PM EDT TUE APR 21 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 352 PM EDT TUE APR 21 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO OVER
THE UPR LKS DOWNSTREAM OF HI AMPLITUDE UPR RDG OVER WRN NAMERICA.
COMBINATION OF DEEP CYC FLOW W TO NW FLOW AND INSTABILITY ENHANCED
BY DAYTIME HEATING UNDER ACCOMAPANYING THERMAL TROF /12Z H5 TEMP AT
GRB WAS -31C/ AND DEEP MSTR SHOWN ON THE 12Z RAOBS IS RESULTING IN
SCT-NMRS SN SHOWERS THAT ARE MIXED WITH RA IN THE WARMER LOCATIONS.
BUT COLDER CLD TOP TEMPS/MORE WIDESRPEAD SN SHOWERS ARE CONFINED
MAINLY TO NW ONTARIO/FAR NRN MN IN AREA WHERE MODELS INDICATE DEEP
QVECTOR CNVGC.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS AND POTENTIAL SN
ACCUMS ASSOCIATED WITH DEEP CYC...MOIST NW FLOW ARND SLOW MOVING
CLOSED LO TO THE NE OF UPR MI.
CLOSED LO CENTERED OVER ERN LK SUP THIS AFTN IS FCST TO DRIFT SLOWLY
TO THE NE AND TO JUST S OF JAMES BAY ON WED. ALTHOUGH ACCOMPANYING
DEEP LYR QVECTOR CNVGC THAT IS SUPPORTING COLDER CLD TOPS TO THE NW
IS FCST TO REMAIN TO THE N OF UPR MI...PERSISTENT MOIST...CYC NW
FLOW ARND THIS FEATURE WL MAINTAIN AT LEAST CHC POPS OVER THE CWA
THRU WED...WITH THE LOWER POPS GENERALLY OVER THE SCENTRAL AND THE
HIER POPS OVER THE HIER TERRAIN OF THE NW WITH UPSLOPE WIND
COMPONENT. BUT LOSS OF DAYTIME HEATING TNGT WL CAUSE THE
CHARACTER OF THE SHOWER PATTERN TO TRANSITIONS FM ONE THAT SUPPORTS
THE HIER POPS OVER THE INTERIOR THIS AFTN TO A MORE WINTRY LES
LOOK TNGT. IN FACT...THE NW FLOW IS PROGGED TO ADVECT H85 TEMPS AS
LO AS -13 TO -14C OVER THE KEWEENAW BY 12Z WED...TEMPS LO ENUF TO
SUPPORT LES AND INCRS SN/WATER RATIOS ONCE THE EFFECT OF DAYTIME
INSOLATION HAS FADED. OVER THE HIER TERRAIN OF THE W...THERE WL
LIKELY BE SEVERAL INCHES OF WET SN ACCUM TNGT INTO WED MRNG EVEN IN
THE ABSENCE OF SGNFT LARGER SCALE FORCING. OPTED TO ISSUE AN SPS
TO ALERT THE PUBLIC TO THE POTENTIAL OF SOME SLUSHY SN ACCUMS ON
ROADS LATER THIS EVNG INTO WED MRNG. DAYTIME HEATING ON WED WL
BRING ABOUT A RETURN TO A MORE LAND BASED INSTABILITY SHOWER
PATTERN. BUT SOMEWHAT HIER HGTS/SHARPENING MID LVL INVRN FARTHER FM
THE SLOWLY DEPARTING CLOSED LO THAT RESTRICTS DESTABILIZATION WL
TEND TO LIMIT COVERAGE/INTENSITY OF THE SHOWERS AS COMPARED TO TODAY.
ALTHOUGH H85 TEMPS ARE FCST TO MODERATE TO -10C TO -12C...MAX TEMPS
ON WED WL HOLD IN THE 30S EXPECT WHERE SOME DOWNSLOPE WARMING AIDS
DIURNAL TEMP RECOVERY INTO THE LO 40S OVER THE SCENTRAL. THERE COULD
BE SOME RECORD LO MAX TEMPS ON WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 PM EDT TUE APR 21 2015
THE UPPER LOW THAT IS CURRENTLY AFFECTING THE AREA WILL SHIFT EAST
INTO THE CANADIAN MARITIMES SHORTLY AFTER THE START OF THE LONG TERM
PERIOD. THIS WILL LEAVE THE AREA BETWEEN THAT UPPER LOW AND AN UPPER
RIDGE IN THE CENTRAL/SOUTHERN PLAINS. THUS...THE AREA WILL BE UNDER
NORTHWESTERLY FLOW ALOFT FOR MOST DAYS THROUGH THE UPCOMING WEEKEND.
WITH A SURFACE RIDGE STRETCHING SOUTH FROM A HIGH IN NORTHERN CANADA
MOVING INTO THE AREA BY FRIDAY AND FRIDAY NIGHT...EXPECT DRIER AIR
TO GRADUALLY MOVE INTO THE REGION AND DIMINISH THE PRECIPITATION
POTENTIAL AND LEAD TO A DRY WEEKEND (ALTHOUGH THERE ARE HINTS OF A
WEAK DISTURBANCE BRINGING AN ISOLATED SHOWER TO THE FAR WESTERN U.P.
LATE FRIDAY NIGHT INTO SATURDAY MORNING). WITH THE MAIN UPPER LOW
SHIFTING EAST...TEMPERATURES WILL SLOWLY WARM BUT STILL STAY BELOW
NORMAL FOR LATE APRIL (AIDED BY THE LIGHT NORTHERLY FLOW OFF LAKE
SUPERIOR).
HEADING INTO NEXT WEEK...THE UPPER LOW CURRENTLY OVER THE GULF OF
ALASKA WILL MOVE INTO THE PACIFIC NORTHWEST OVER THE NEXT 24-48HRS
AND THEN INTO THE CENTRAL CONUS ON MONDAY. AS THE WAVE CONTINUES
EAST...IT WILL INTERACT WITH THE UPPER LOW NEAR THE CANADIAN
MARITIMES AND RE-ESTABLISH THE UPPER TROUGH OVER THE EASTERN CONUS.
THIS WILL KEEP BELOW NORMAL TEMPERATURES IN PLACE INTO NEXT WEEK AND
POSSIBLY LEAD TO SOME SHOWERS AROUND THE GREAT LAKES REGION.
OVERALL...FAIRLY COOL AND QUIET END TO APRIL WITH NO HAZARDOUS
WEATHER EXPECTED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 750 PM EDT TUE APR 21 2015
AS DEEP MOISTURE LINGERS AND COLDER AIR ARRIVES TONIGHT...SHSN WILL
TEND TO INCREASE IN FREQUENCY AT KIWD/KCMX WITH USPLOPE NW WIND
COMPONENT OFF LAKE SUPERIOR. EXPECT A TREND TO PREVAILING IFR BY
LATE EVENING...THEN CONTINUING THRU MID MORNING WED. TYPICAL FOR
SHSN...THERE WILL LIKELY BE FLUCTUATION WITH SOME BRIEF PERIODS OF
LIFR AND MVFR. INTO WED AFTN...EXPECT IMPROVEMENT TO MVFR AS SHSN
INTENSITY DIMINISHES. DOWNSLOPE NATURE OF THE NW FLOW WILL LIMIT THE
POTENTIAL FOR LOWER VIS/CIG AT KSAW...BUT MVFR CIGS SHOULD BECOME
PREVAILING MID TO LATE EVENING WITH RATHER MOIST LOW-LEVELS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 305 PM EDT TUE APR 21 2015
NORTHWESTERLY WINDS UP TO 30 KNOTS WILL CONTINUE OVER LAKE SUPERIOR
THROUGH THURSDAY MORNING. THERE COULD BE A FEW PERIODS OF GALE
FORCE GUSTS TO 35KTS LATE TONIGHT INTO WEDNESDAY...BUT THEY
SHOULDN/T BE WIDESPREAD. HIGH PRESSURE WILL BEGIN TO BUILD INTO
WESTERN LAKE SUPERIOR THURSDAY AFTERNOON/NIGHT AND LEAD TO
GRADUALLY DIMINISHING WINDS INTO FRIDAY. LIGHT NORTHERLY WINDS UP
TO 15KTS ARE EXPECTED THIS WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
353 PM EDT MON APR 20 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM EDT MON APR 20 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEPENING UPR TROF
OVER CENTRAL NAMERICA BTWN RDGS ALONG THE E AND W COASTS...WITH 12HR
H5 HGT FALLS UP TO 150M NOTED OVER NRN WI IN ADVANCE OF SHRTWV
LIFTING NWD INTO THE UPR LKS TO THE E OF THE UPR TROF AXIS. IR AND
WV IMAGERY SHOW A WELL DEFINED COMMA HEAD CLD OVER THE UPR GREAT LKS
IN ADVANCE OF SHRTWV AND ON CYC SIDE OF ACCOMPANYING H7 LO TRACK.
STEADY RA UNDER THIS COMMA HEAD HAS MIXED WITH SN OVER THE WRN CWA
WHERE DYNAMIC COOLING AND SOME LLVL CAA HAVE COOLED THE COLUMN
SUFFICIENTLY. FARTHER TO THE E...DRY SLOTTING ON THE ACYC SIDE OF H7
LO TRACK HAS TENDED TO DIMINISH THE PCPN COVERAGE/INTENSITY OVER THE
FAR E. ANOTHER SHRTWV IS DIGGING SWD THRU FAR NW ONTARIO/MANITOBA ON
THE WRN FLANK OF H5 CLOSED LO
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/PTYPE ASSOCIATED
WITH SHRTWV MOVING THRU THE UPR LKS RIGHT NOW AND THEN TNGT/TMRW
ACCOMPANYING PASSAGE OF NEXT SHRTWV AND WITHIN LINGERING DEEP CYC
FLOW UNDER CUTOFF H5 LO PROGGED TO LINGER OVER THE UPR LKS.
LATE TDAY/TNGT...AS SHRTWV E OF THE UPR TROF AXIS LIFTS TO THE N
THRU THIS AFTN AND TENDS TO SHEAR OUT...MODELS SHOW AREA OF SHARP
DEEP LYR QVECTOR CNVGC SUPPORTING AXIS OF COLDER CLD TOPS
DIMINISHING AND GIVING WAY TO SOME DEEP LYR QVECTOR DVGC. SO AREA OF
STEADY RA/SN OVER THE W SHOULD DIMINISH BY LATE AFTN WITH ARRIVAL OF
THE NEGATIVE DYNAMICS/MID LVL DRYING. POPS OVER THE E WL TEND TO
INCREASE LATE THIS AFTN/EARLY EVNG AS COMMA TAIL AXIS OF HIER RH
SWINGS E THRU THAT AREA...BUT PCPN INTENSITY WL NOT BE AS GREAT AS
OVER THE W SINCE THE SUPPORTING AXIS OF DIMINISHING DEEP LYR QVECTOR
CNVGC IS FCST TO REMAIN OVER THE W. NOT OUT OF THE QUESTION THERE
COULD BE A FEW INCHES OF WET SN ACCUM OVER THE HIER TERRAIN OF THE
W...BUT THERE SHOULD BE LTL IF ANY SN OVER THE E HALF WITH WEAKER
DYNAMIC FORCING/COOLING. LATER TNGT...THE TRAILING SHRTWV DIGGING
SWD TOWARD NW MN ON THE WRN FLANK OF CLOSED H5 LO IS FCST TO DIG TO
NEAR NW WI BY 12Z TUE...BRINGING SOME DPVA/MORE DEEP LYR QVECTOR
CNVGC TO THE W LATER TNGT. SHARP CYC UPSLOPE WNW FLOW IN THE
PRESENCE OF THE DEEPER FORCING/MSTR WL SUPPORT LIKELY POPS IN THIS
AREA. THERE COULD BE A FEW INCHES OF WET SN ACCUM OVER MAINLY THE
HIER TERRAIN. OVER THE CENTRAL AND E...THERE WL BE ONLY ISOLD-SCT RA
AND SN SHOWERS.
TUE...SHRTWV/ACCOMPANYING SFC LO PRES TROF ROTATING ARND CLOSED H5
LO SHIFTING SLOWLY TO THE E OVER LK SUP IS FCST TO WEAKEN SLOWLY...
LEADING TO SLOWLY DIMINISHING DEEP LYR QVECTOR CNVGC. ALTHOUGH THESE
TRENDS WL RESULT IN DIMINISHING POPS...DAYTIME HEATING/LLVL
DESTABILIZATION WL ENHANCE POPS ESPECIALLY OVER THE ERN CWA IN THE
AFTN...WHERE LLVL CNVGC WITHIN LO PRES TROF WL BE ENHANCED BY LK
BREEZE DEVELOPMENT. OTRW...LINGERING SHARP LLVL CNVGC AND THE
DAYTIME HEATING WL MAINTAIN AT LEAST CHC POPS. THE PCPN SHOULD BE
MAINLY SN IN THE MRNG...BUT THIS PCPN WL MIX WITH/CHG TO RA OVER THE
SE HALF IN THE AFTN WITH DAYTIME HEATING/TEMPS RISING AOA 40.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015
A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.
AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).
EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015
AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT MON APR 20 2015
SHARP PRES GRADIENT ON THE SW FLANK OF SLOW MOVING LO PRES IN
ONTARIO WILL CAUSE W TO NW WINDS UP TO 25-30 KTS INTO THU. ALTHOUGH
THERE COULD BE SOME GALE FORCE GUSTS AT TIMES...WIDESPREAD GALES ARE
NOT EXPECTED. THE CLOSER APPROACH OF HI PRES LATER IN THE WEEK WILL
RESULT IN NW WINDS DIMINISHING TO NO MORE THAN 20 KTS ON FRI AND
SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
333 AM EDT MON APR 20 2015
.SYNOPSIS...
WIDESPREAD RAIN WILL DEVELOP OVER OUR AREA LATER TONIGHT INTO
EARLY MONDAY AS A STORM SYSTEM MOVES THROUGH THE GREAT LAKES.
AFTER A BRIEF LULL IN RAIN MIDDAY MONDAY, ANOTHER ROUND OF SHOWERS
IS POSSIBLE MONDAY AFTERNOON AND EVENING. DURING THAT TIME
SCATTERED THUNDERSTORMS ARE POSSIBLE. WE WILL REMAIN UNSETTLED AND
VERY COOL THE REST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
940 PM UPDATE...
TIMING OF RAINFALL LOOKS TO BE ON TRACK. I TWEAKED THE OVERNIGHT
WIND GRIDS A BIT. WE STILL HAVE GUSTS OVER 40 MPH ON THE HILLTOPS
ABOVE 1500 FEET. I INCREASED WIND IN THE LAKE PLAIN, SHOWING SOME
GUSTS IN THE LOWER 30S AT KSYR. RUC SOUNDINGS SEEM A BIT LOW HERE
GIVEN FAVORABLE SOUTHEAST DOWNSLOPING AND MAV GUIDANCE SHOWING
SUSTAINED WINDS IN THE LOWER 20S. OTHERWISE PREVIOUS AFD IS
BELOW...
300 PM UPDATE...
A BEAUTIFUL END TO OUR WEEKEND ALBEIT A GOOD 10 DEGREES OR SO
COOLER THAN YESTERDAY AFTERNOON. I HOPE YOU ENJOYED THE WEEKEND
BECAUSE THE WEATHER THROUGH THE END OF THE MONTH DOESN`T LOOK ALL
THAT GOOD.
WE ARE ALREADY SEEING SIGNS OF THOSE CHANGES IN THE FORM OF SOME
THIN WISPY HIGH CLOUDS. THESE ARE WELL AHEAD OF AN AREA OF LOW
PRESSURE NOW OVER ILLINOIS THAT WILL TRACK THROUGH THE GREAT
LAKES MONDAY. A LARGE SHIELD OF RAIN WELL AHEAD OF A WARM FRONT
WITH THIS SYSTEM WILL MOVE IN TONIGHT. NOT EXPECTING ANY HYDRO
ISSUES BUT A QUICK SHOT OF STEADY RAIN IS LIKELY FOR EVERYONE.
THE BIG STORY TONIGHT MAY BE THE WIND, ESPECIALLY ACROSS THE
HIGHER ELEVATIONS THAT FAVOR A SOUTHEAST WIND FLOW. WHILE WE ARE
VERY STABLE JUST A FEW THOUSAND FEET UP AND RAIN WILL LIKELY
TEMPER WINDS A BIT, STRONG WINDS UNDER THE INVERSION WILL FAVOR
LOCALLY STRONG GUSTS ON THE HILLTOPS. IN GENERAL GUSTS TO 20 MPH
ARE LIKELY TONIGHT FOR MOST OF US. FAVORED TERRAIN AREAS WILL
GUST BETWEEN 30 AND 40 MPH. THIS INCLUDES THE CATSKILLS, HIGHER
TERRAIN OF NEPA AND THE WESTERN SOUTHERN TIER AND THE HILLS SOUTH
OF SYRACUSE. WOULD NOT BE SURPRISED TO SEE A FEW GUSTS ABOVE 40
MPH ACROSS AREAS SUCH AS SEMPRONIUS, POMPEY, GEORGETOWN, IN THE
FAVORED SOUTHEAST FLOW AREAS SOUTH OF SYRACUSE.
MONDAY...
MODEL CONSENSUS STILL FAVORS THE STEADIER RAIN SLIDING EAST AND
PERHAPS EVEN OUT OF OUR AREA BY MIDDAY. MOST OF OUR AREA WILL GET
INTO THE WARM SECTOR BY AFTERNOON AND PERHAPS EVEN A FEW BREAKS IN
THE CLOUD COVER. THIS MAY GIVE US JUST ENOUGH INSTABILITY,
ESPECIALLY IF WE CAN SEE SOME SUN, TO COMBINE WITH A COLD FRONT
APPROACHING DURING THE EVENING FOR SOME THUNDERSTORMS. SPC DAY 2
OUTLOOK HAS MOVED THE SLIGHT RISK TOWARD OUR AREA AND JUST BRUSHES
SOUTHERN LUZERNE COUNTY. IN ADDITION A MARGINAL RISK (OLD SEE TEXT
FROM PAST YEARS) IS NOW UP TO NEAR THE NY STATE THRUWAY. WILL
CONTINUE TO MENTION T-STORMS IN THE FORECAST. SHEAR VALUES ARE
GOOD BUT IT WILL COME DOWN TO HOW MUCH INSTABILITY WE CAN REALIZE
DURING THE AFTERNOON TO DETERMINE SEVERE RISK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
345 PM UPDATE...
A COLD FRONT WILL BE MOVING THROUGH THE AREA MONDAY EVENING. WITH
LINGERING INSTABILITY, THUNDERSTORMS WILL BE POSSIBLE ACROSS THE
ENTIRE AREA. ALL HI RESOLUTION GUIDANCE POINTS TO THE POTENTIAL
OF A SQUALL LINE BETWEEN 21Z MONDAY AND 03Z TUESDAY ROUGHLY FROM
THE SOUTHERN TIER OF NY INTO NEPA. ADJUSTED OUR CURRENT HWO TO
REFLECT THIS THREAT ESPECIALLY ACROSS NEPA, WHICH IS CLOSE TO
WHAT SPC IS FORECASTING FOR SEVERE RISK.
BEYOND MONDAY NIGHT, THE PERIOD WILL BE DOMINATED BY A CLOSED
UPPER LOW JUST NORTH OF THE GREAT LAKES. GRADUALLY THROUGH THE
PERIOD WE WILL SEE PROGRESSIVELY COOLER AIR FILTER INTO THE AREA
ALONG WITH PERIODS OF SHOWERS. THIS WILL TRANSLATE INTO NEAR
NORMAL HIGHS TUESDAY (MID TO UPPER 50S) BUT THEN BELOW NORMAL
HIGHS BY WEDNESDAY. IN FACT SOME AREAS MAY NOT GET OUT OF THE 40S
FOR HIGHS WEDNESDAY AFTERNOON. THROUGH WEDNESDAY MOST AREAS WILL
SEE JUST RAIN SHOWERS. 850 TEMPS DO DROP BELOW ZERO BY WED MORNING
SO A STRAY FLAKE COULDN`T BE RULED OUT IN CNY EARLY IN THE DAY,
BUT THE APPRECIABLE COLDER AIR HOLDS OFF UNTIL WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
0330 AM UPDATE...NO CHANGES WERE MADE TO THE LONG TERM GRIDS WITH
THIS UPDATE AS MODELS IN OVERALL GOOD AGREEMENT CONTINUING TO
INDICATE COOL, GENERALLY UNSETTLED CONDITIONS FOR THE LONG RANGE.
PREVIOUS DISCUSSION...THE EXTENDED FORECAST WILL BE DOMINATED BY
AN UPPER LEVEL LOW WHICH SLOWLY MOVES FROM NEARBY SOUTHERN ONTARIO
TO NOVA SCOTIA. WILL CONTINUE TO ADVERTISE CHC/SLIGHT CHC POPS
EACH DAY. BEST CHANCES FOR SHOWERS WILL BE WED NIGHT WITH THE
PASSAGE OF A SFC OCCLUSION AND DURING THE DAYTIME PERIODS AS COLD
POOL ALOFT AND DIURNAL INSTABILITY WILL INCREASE COVERAGE. AIRMASS
IS COLD ENOUGH DURING THE OVERNIGHT PERIODS FOR A SNOW/RAIN SHOWER
MIX. TEMPS WILL RUN 5 TO 15 DEGREES BELOW NORMAL.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
06Z MON UPDATE... THE MOST SIG ISSUE THIS PD IS LIKELY TO BE THE
GUSTY SFC WINDS/LLWS...SPCLY LTR TNT AND MON MRNG. GIVEN AN
EXPECTED SE FLOW...KSYR/KITH/KBGM ARE LIKELY TO EXPERIENCE THE
STGST/MOST PERSISTENT GUSTS...WITH LOCAL TERRAIN EFFECTS (30-35 KT
INDICATED). LLWS WILL ESPECIALLY BE A CONCERN AT KELM/KAVP...WITH
THE MOST SIGNIFICANT WIND SPEED DIFFERENCE BETWEEN THE SFC AND
2000 FEET AGL (PROJECTED WINDS AT THE 2000 FOOT LVL OF 50-60 KT)
HOWEVER WE HAVE ADDED IT FOR THE OTHER SITES AS WELL WITH THIS
UPDATE AS CRITERIA IS EXPECTED TO BE MET.
VFR WILL CONTINUE FOR MUCH OF THE OVERNIGHT PD. SOME RESTRICTIONS
ARE PSBL MON MRNG...WHEN A BAND OF STEADIER RAIN IS EXPECTED TO
CROSS THE RGN. MVFR RESTRICTIONS ARE THE MOST LIKELY SCENARIO
(ROUGHLY 08-16Z)...WITH KRME/KBGM/KITH THE MOST PROBABLE SITES TO
BE IMPACTED.
FOR MOST OF MON AFTN...VFR SHOULD RETURN...AS A LULL IN PCPN IS
EXPECTED. LATE IN THE DAY (AFTER 21Z)...A LN OF SHWRS/PSBL TSTMS
WILL LIKELY IMPACT THE AREA...WITH MVFR RESTRICTIONS AGN PSBL. ANY
STORMS COULD ALSO PRODUCE STRONG WIND GUSTS WITH EVEN THE RISK OF
HAIL. FOR THE TIME BEING...FCST RANGE (OUT NEARLY 18 HRS) AND
UNCERTAIN COVERAGE PRECLUDES MENTION OF THUNDER IN THE TERMINAL
FCSTS BUT THE BEST CHANCE FOR STORMS WILL BE FOR KELM/KAVP/KBGM.
.OUTLOOK...
MON NIGHT-FRI...UNSETTLED PATTERN. RESTRICTIONS IN -SHRA, LOW
CLOUDS...ESP MON NGT.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...HEDEN
SHORT TERM...HEDEN
LONG TERM...PCF/RRM
AVIATION...PCF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
156 AM EDT MON APR 20 2015
.SYNOPSIS...
WIDESPREAD RAIN WILL DEVELOP OVER OUR AREA LATER TONIGHT INTO
EARLY MONDAY AS A STORM SYSTEM MOVES THROUGH THE GREAT LAKES.
AFTER A BRIEF LULL IN RAIN MIDDAY MONDAY, ANOTHER ROUND OF SHOWERS
IS POSSIBLE MONDAY AFTERNOON AND EVENING. DURING THAT TIME
SCATTERED THUNDERSTORMS ARE POSSIBLE. WE WILL REMAIN UNSETTLED AND
VERY COOL THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
940 PM UPDATE...
TIMING OF RAINFALL LOOKS TO BE ON TRACK. I TWEAKED THE OVERNIGHT
WIND GRIDS A BIT. WE STILL HAVE GUSTS OVER 40 MPH ON THE HILLTOPS
ABOVE 1500 FEET. I INCREASED WIND IN THE LAKE PLAIN, SHOWING SOME
GUSTS IN THE LOWER 30S AT KSYR. RUC SOUNDINGS SEEM A BIT LOW HERE
GIVEN FAVORABLE SOUTHEAST DOWNSLOPING AND MAV GUIDANCE SHOWING
SUSTAINED WINDS IN THE LOWER 20S. OTHERWISE PREVIOUS AFD IS
BELOW...
300 PM UPDATE...
A BEAUTIFUL END TO OUR WEEKEND ALBEIT A GOOD 10 DEGREES OR SO
COOLER THAN YESTERDAY AFTERNOON. I HOPE YOU ENJOYED THE WEEKEND
BECAUSE THE WEATHER THROUGH THE END OF THE MONTH DOESN`T LOOK ALL
THAT GOOD.
WE ARE ALREADY SEEING SIGNS OF THOSE CHANGES IN THE FORM OF SOME
THIN WISPY HIGH CLOUDS. THESE ARE WELL AHEAD OF AN AREA OF LOW
PRESSURE NOW OVER ILLINOIS THAT WILL TRACK THROUGH THE GREAT
LAKES MONDAY. A LARGE SHIELD OF RAIN WELL AHEAD OF A WARM FRONT
WITH THIS SYSTEM WILL MOVE IN TONIGHT. NOT EXPECTING ANY HYDRO
ISSUES BUT A QUICK SHOT OF STEADY RAIN IS LIKELY FOR EVERYONE.
THE BIG STORY TONIGHT MAY BE THE WIND, ESPECIALLY ACROSS THE
HIGHER ELEVATIONS THAT FAVOR A SOUTHEAST WIND FLOW. WHILE WE ARE
VERY STABLE JUST A FEW THOUSAND FEET UP AND RAIN WILL LIKELY
TEMPER WINDS A BIT, STRONG WINDS UNDER THE INVERSION WILL FAVOR
LOCALLY STRONG GUSTS ON THE HILLTOPS. IN GENERAL GUSTS TO 20 MPH
ARE LIKELY TONIGHT FOR MOST OF US. FAVORED TERRAIN AREAS WILL
GUST BETWEEN 30 AND 40 MPH. THIS INCLUDES THE CATSKILLS, HIGHER
TERRAIN OF NEPA AND THE WESTERN SOUTHERN TIER AND THE HILLS SOUTH
OF SYRACUSE. WOULD NOT BE SURPRISED TO SEE A FEW GUSTS ABOVE 40
MPH ACROSS AREAS SUCH AS SEMPRONIUS, POMPEY, GEORGETOWN, IN THE
FAVORED SOUTHEAST FLOW AREAS SOUTH OF SYRACUSE.
MONDAY...
MODEL CONSENSUS STILL FAVORS THE STEADIER RAIN SLIDING EAST AND
PERHAPS EVEN OUT OF OUR AREA BY MIDDAY. MOST OF OUR AREA WILL GET
INTO THE WARM SECTOR BY AFTERNOON AND PERHAPS EVEN A FEW BREAKS IN
THE CLOUD COVER. THIS MAY GIVE US JUST ENOUGH INSTABILITY,
ESPECIALLY IF WE CAN SEE SOME SUN, TO COMBINE WITH A COLD FRONT
APPROACHING DURING THE EVENING FOR SOME THUNDERSTORMS. SPC DAY 2
OUTLOOK HAS MOVED THE SLIGHT RISK TOWARD OUR AREA AND JUST BRUSHES
SOUTHERN LUZERNE COUNTY. IN ADDITION A MARGINAL RISK (OLD SEE TEXT
FROM PAST YEARS) IS NOW UP TO NEAR THE NY STATE THRUWAY. WILL
CONTINUE TO MENTION T-STORMS IN THE FORECAST. SHEAR VALUES ARE
GOOD BUT IT WILL COME DOWN TO HOW MUCH INSTABILITY WE CAN REALIZE
DURING THE AFTERNOON TO DETERMINE SEVERE RISK.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
345 PM UPDATE...
A COLD FRONT WILL BE MOVING THROUGH THE AREA MONDAY EVENING. WITH
LINGERING INSTABILITY, THUNDERSTORMS WILL BE POSSIBLE ACROSS THE
ENTIRE AREA. ALL HI RESOLUTION GUIDANCE POINTS TO THE POTENTIAL
OF A SQUALL LINE BETWEEN 21Z MONDAY AND 03Z TUESDAY ROUGHLY FROM
THE SOUTHERN TIER OF NY INTO NEPA. ADJUSTED OUR CURRENT HWO TO
REFLECT THIS THREAT ESPECIALLY ACROSS NEPA, WHICH IS CLOSE TO
WHAT SPC IS FORECASTING FOR SEVERE RISK.
BEYOND MONDAY NIGHT, THE PERIOD WILL BE DOMINATED BY A CLOSED
UPPER LOW JUST NORTH OF THE GREAT LAKES. GRADUALLY THROUGH THE
PERIOD WE WILL SEE PROGRESSIVELY COOLER AIR FILTER INTO THE AREA
ALONG WITH PERIODS OF SHOWERS. THIS WILL TRANSLATE INTO NEAR
NORMAL HIGHS TUESDAY (MID TO UPPER 50S) BUT THEN BELOW NORMAL
HIGHS BY WEDNESDAY. IN FACT SOME AREAS MAY NOT GET OUT OF THE 40S
FOR HIGHS WEDNESDAY AFTERNOON. THROUGH WEDNESDAY MOST AREAS WILL
SEE JUST RAIN SHOWERS. 850 TEMPS DO DROP BELOW ZERO BY WED MORNING
SO A STRAY FLAKE COULDN`T BE RULED OUT IN CNY EARLY IN THE DAY,
BUT THE APPRECIABLE COLDER AIR HOLDS OFF UNTIL WEDNESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE EXTENDED FORECAST WILL BE DOMINATED BY AN UPPER LEVEL LOW
WHICH SLOWLY MOVES FROM NEARBY SOUTHERN ONTARIO TO NOVA SCOTIA.
WILL CONTINUE TO ADVERTISE CHC/SLIGHT CHC POPS EACH DAY. BEST
CHANCES FOR SHOWERS WILL BE WED NIGHT WITH THE PASSAGE OF A SFC
OCCLUSION AND DURING THE DAYTIME PERIODS AS COLD POOL ALOFT AND
DIURNAL INSTABILITY WILL INCREASE COVERAGE. AIRMASS IS COLD ENOUGH
DURING THE OVERNIGHT PERIODS FOR A SNOW/RAIN SHOWER MIX. TEMPS
WILL RUN 5 TO 15 DEGREES BELOW NORMAL.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
06Z MON UPDATE... THE MOST SIG ISSUE THIS PD IS LIKELY TO BE THE
GUSTY SFC WINDS/LLWS...SPCLY LTR TNT AND MON MRNG. GIVEN AN
EXPECTED SE FLOW...KSYR/KITH/KBGM ARE LIKELY TO EXPERIENCE THE
STGST/MOST PERSISTENT GUSTS...WITH LOCAL TERRAIN EFFECTS (30-35 KT
INDICATED). LLWS WILL ESPECIALLY BE A CONCERN AT KELM/KAVP...WITH
THE MOST SIGNIFICANT WIND SPEED DIFFERENCE BETWEEN THE SFC AND
2000 FEET AGL (PROJECTED WINDS AT THE 2000 FOOT LVL OF 50-60 KT)
HOWEVER WE HAVE ADDED IT FOR THE OTHER SITES AS WELL WITH THIS
UPDATE AS CRITERIA IS EXPECTED TO BE MET.
VFR WILL CONTINUE FOR MUCH OF THE OVERNIGHT PD. SOME RESTRICTIONS
ARE PSBL MON MRNG...WHEN A BAND OF STEADIER RAIN IS EXPECTED TO
CROSS THE RGN. MVFR RESTRICTIONS ARE THE MOST LIKELY SCENARIO
(ROUGHLY 08-16Z)...WITH KRME/KBGM/KITH THE MOST PROBABLE SITES TO
BE IMPACTED.
FOR MOST OF MON AFTN...VFR SHOULD RETURN...AS A LULL IN PCPN IS
EXPECTED. LATE IN THE DAY (AFTER 21Z)...A LN OF SHWRS/PSBL TSTMS
WILL LIKELY IMPACT THE AREA...WITH MVFR RESTRICTIONS AGN PSBL. ANY
STORMS COULD ALSO PRODUCE STRONG WIND GUSTS WITH EVEN THE RISK OF
HAIL. FOR THE TIME BEING...FCST RANGE (OUT NEARLY 18 HRS) AND
UNCERTAIN COVERAGE PRECLUDES MENTION OF THUNDER IN THE TERMINAL
FCSTS BUT THE BEST CHANCE FOR STORMS WILL BE FOR KELM/KAVP/KBGM.
.OUTLOOK...
MON NIGHT-FRI...UNSETTLED PATTERN. RESTRICTIONS IN -SHRA...ESP
MON NGT.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...HEDEN
SHORT TERM...HEDEN
LONG TERM...RRM
AVIATION...PCF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 PM EDT MON APR 20 2015
.SYNOPSIS...A COLD FRONT WILL TRACK EAST ACROSS THE REGION TONIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST LATE TONIGHT THROUGH
TUESDAY... THEN SHIFT OFF THE COAST TUESDAY NIGHT INTO WEDNESDAY.
A COLD FRONT WILL APPROACH FROM THE NORTH WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...
NOW THROUGH THIS EVENING: NUMEROUS SIGNALS CONTINUE TO SUPPORT AN
ENHANCED RISK OF SEVERE STORMS IN CENTRAL NC. HEATING/MIXING
DISSIPATED THE WEAK CAP OVER THE REGION NEARLY 2 HOURS AGO...
YIELDING EXPLOSIVE CONVECTION TO OUR SW OVER NE GA AND UPSTATE SC.
SEE NO REASON WHY THIS WON`T CONTINUE TO EXPAND NORTHEASTWARD TOWARD
CENTRAL NC OVER THE NEXT FEW HOURS. KINEMATICS REMAIN ROBUST WITH
EFFECTIVE DEEP LAYER SHEAR OVER 40 KTS (ACCORDING TO SPC
MESOANALYSES) AND RAP ANALYSES REVEALING A LONG STRAIGHT LINE
HODOGRAPH SUPPORTIVE OF SPLITTING SUPERCELLS. MLCAPE AND MUCAPE
VALUES ARE RAPIDLY GROWING AND NOW SIT NEAR 1000 J/KG AND 1500-2000
J/KG RESPECTIVELY... AND LOW LEVEL LAPSE RATES HAVE REACHED NEAR 8
C/KM. THESE FACTORS ALONG WITH DERIVED PARAMETERS INCLUDING THE
CRAVEN SIGSVR AND SUPERCELL COMPOSITE PARAMETER SUPPORT SUSTAINED
SUPERCELLS. PW VALUES ARE ABOVE NORMAL BUT NOT INCREDIBLY HIGH...
AND THIS MAY LIMIT COVERAGE SOMEWHAT INITIALLY... BUT ALL
INDICATIONS ARE THAT CONVECTION WILL GROW AND CONGEAL INTO A LINEAR
MCS OR OR MULTICELL CLUSTERS AFFECTING A LARGER AREA. DAMAGING
STRAIGHT LINE WINDS AND LARGE HAIL STILL LOOK TO BE THE PRIMARY
THREATS... GIVEN THE LONG STRAIGHT HODOGRAPH AND FAT CAPE IN THE 0C
TO -30C LAYER WITH CONVECTION ALLOWING MODELS INDICATING STRONG
UPDRAFTS. INTENSE TORNADOES LOOK TO BE LESS LIKELY WITH LCL HEIGHTS
UP TO 1000 M CURRENTLY AND SOMEWHAT MARGINAL STORM RELATIVE HELICITY
VALUES... BUT A FEW TORNADOES REMAIN POSSIBLE IN THIS ENVIRONMENT.
STORM MOTION IS EXPECTED TO BE 40-50 MPH FROM THE WSW... AND THESE
TRANSLATIONAL SPEEDS WILL EXACERBATE THE EFFECTS OF ANY STRONG WINDS
ASSOCIATED WITH INDIVIDUAL STORMS. STRONG TO SEVERE CONVECTION NOW
OVER THE GSP CWA WILL CONTINUE TO EXPAND TO THE NE... SO EXPECT THE
GREATEST SEVERE RISK OVER CENTRAL NC TO BE BETWEEN 4 PM AND 8 PM...
GRADUALLY TAPERING DOWN AFTERWARD... WITH LITTLE MORE THAN ISOLATED
TRAILING SHOWERS AFTER 11 PM.
AFTER MIDNIGHT: THE COLD FRONT WILL MOVE ESE THROUGH CENTRAL NC
BETWEEN MIDNIGHT AND 6 AM... AND EXPECT CLEARING SKIES WITH THE
ONSET OF DOWNSLOPE LOW LEVEL FLOW AND A DRYING COLUMN. STILL EXPECT
LOWS FROM AROUND 50 IN THE NW TO AROUND 60 SE AS COOLER AIR RUSHES
IN LATE. -GIH
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 PM MONDAY...
THE COLD FRONT WILL HAVE PUSHED JUST SE OF THE FORECAST AREA BY
DAYBREAK TUE... WITH HIGH PRESSURE BUILDING IN FROM THE GULF
STATES... THEN DRIFTING ACROSS GA/SRN SC. FORECAST SOUNDINGS SHOW A
STABLE AND DRY COLUMN WITH JUST A FEW FLAT CU NEAR THE TOP OF THE
MIXED LAYER IN THE AFTERNOON. A PASSING WEAK VORTICITY MAX COULD
ALSO BRING A STREAM OF MID/HIGH CLOUDS IN THE EVENING. HIGHS BELOW
NORMAL AT 68-74 WITH PARTLY TO MOSTLY SUNNY SKIES. MOSTLY CLEAR TUE
NIGHT WITH THE HIGH SHIFTING OFF THE COAST. LOWS 44-50. -GIH
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
WEDNESDAY THROUGH THURSDAY NIGHT...DRY CONDITIONS WILL PERSIST ON
WEDNESDAY AS HIGH PRESSURE ACROSS THE SOUTHEAST US GRADUALLY SLIPS
OFFSHORE WEDNESDAY MORNING/EARLY AFTERNOON. ANOTHER COLD FRONT WILL
APPROACH THE AREA LATE WEDNESDAY INTO THURSDAY. HOWEVER...LIMITED
MOISTURE RETURN AHEAD OF THIS SYSTEM WILL KEEP PRECIP CHANCES
MINIMAL. NEVERTHELESS...WILL KEEP A SLIGHT CHANCE POP IN THE
FORECAST FOR WEDNESDAY NIGHT/EARLY THURSDAY...BUT MOST PLACES WILL
LIKELY STAY DRY AND THOSE THAT SEE PRECIP WILL HAVE MEAGER AMOUNTS.
HIGHS ON WEDNESDAY WILL RISE INTO THE MID/UPPER 70S...WHILE ON
THURSDAY HIGHS WILL RANGE FROM THE UPPER 60S ACROSS THE NORTH
(EARLIER FRONTAL PASSAGE) TO THE MID 70S FURTHER SOUTH. OVERNIGHT
LOWS WILL GENERALLY BE IN THE MID/UPPER 40S TO LOWER 50S (COOLEST
THURSDAY NIGHT BEHIND THE FRONT).
FRIDAY THROUGH MONDAY...UNCERTAINTY REMAINS FAIRLY HIGH WITH RESPECT
TO THE END OF THE WEEK AND ESPECIALLY INTO THE WEEKEND. THE OVERALL
PATTERN INDICATES THE AFOREMENTIONED COLD FRONT WILL STALL JUST
SOUTH OF THE REGION FOR THE END OF THE WEEK. THEN...AS A SOUTHERN
STREAM SYSTEM APPROACHES...MULTIPLE WAVES OF LOW PRESSURE WILL RIDE
ALONG THIS BOUNDARY...SPREADING PRECIP BACK INTO THE AREA.
HOWEVER...AS CAN BE EXPECTED THIS FAR OUT...DETAILS HAVE YET TO BE
WORKED OUT. REGARDLESS...WILL SHOW POPS EARLY IN THE WEEKEND WITH...
AS OF NOW AT LEAST...DRIER CONDITIONS BY SUNDAY. MONDAY ALSO LOOKS
TO BE DRY...BUT ANOTHER SYSTEM IS PROGGED TO BE ON OUR DOORSTEP BY
LATE MONDAY/MONDAY NIGHT. TEMPS WILL GENERALLY BE NEAR TO SLIGHTLY
BELOW NORMAL THROUGH THE TIME FRAME.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 1230 PM MONDAY...
EARLIER MVFR CIGS AT INT/GSO/RDU/FAY HAVE SCATTERED OUT... AND
EXPECT RWI TO FOLLOW SUIT AND BECOME SCT IN THE NEXT HOUR. SCATTERED
STORMS ARE EXPECTED TO FORM OVER NRN GA AND UPSTATE SC THEN MOVE TO
THE NE... LIKELY AFFECTING INT/GSO 19Z-23Z... RDU 20Z-00Z... AND
FAY/RWI 21Z-01Z. VFR CONDITIONS WILL GENERALLY CONTINUE FOR THE NEXT
24 HRS... BUT CIGS/VSBYS IN AND NEAR STORMS WILL DROP TO MVFR OR
BRIEFLY IFR. ENHANCED WIND GUSTS OVER 50 MPH AND HAIL GREATER THAN 1
INCH IN DIAMETER REMAIN POSSIBLE WITH THESE SCATTERED STORMS. EVEN
OUTSIDE OF STORMS... WINDS FROM THE SW AT 10-15 KTS GUSTING TO 20-30
KTS WILL PERSIST... VEERING AROUND TO WESTERLY WITH DIMINISHING
GUSTS AFTER PASSAGE OF A COLD FRONT AFTER 04Z. A SHORT PERIOD OF
MVFR CIGS ARE POSSIBLE WITH FRONTAL PASSAGE... BUT GENERALLY WE
EXPECT VFR CONDITIONS LATE TONIGHT THROUGH THE END OF THE TAF VALID
PERIOD WITH MOSTLY CLEAR SKIES.
LOOKING BEYOND 18Z TUE... VFR CONDITIONS SHOULD HOLD THROUGH WED AS
HIGH PRESSURE BUILDS OVER THE REGION. A FEW HOURS OF SUB-VFR
CIGS/VSBYS WITH A FEW SHOWERS ARE POSSIBLE WED EVENING/NIGHT INTO
EARLY THU AS A DISTURBANCE MOVES QUICKLY ACROSS THE DEEP SOUTH AND
SOUTHEAST STATES. VFR CONDITIONS AND COOLER WEATHER WILL FOLLOW FOR
LATE THU INTO SAT. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...KRD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
312 PM EDT MON APR 20 2015
.SYNOPSIS...A COLD FRONT WILL TRACK EAST ACROSS THE REGION TONIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST LATE TONIGHT THROUGH
TUESDAY... THEN SHIFT OFF THE COAST TUESDAY NIGHT INTO WEDNESDAY.
A COLD FRONT WILL APPROACH FROM THE NORTH WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...
NOW THROUGH THIS EVENING: NUMEROUS SIGNALS CONTINUE TO SUPPORT AN
ENHANCED RISK OF SEVERE STORMS IN CENTRAL NC. HEATING/MIXING
DISSIPATED THE WEAK CAP OVER THE REGION NEARLY 2 HOURS AGO...
YIELDING EXPLOSIVE CONVECTION TO OUR SW OVER NE GA AND UPSTATE SC.
SEE NO REASON WHY THIS WON`T CONTINUE TO EXPAND NORTHEASTWARD TOWARD
CENTRAL NC OVER THE NEXT FEW HOURS. KINEMATICS REMAIN ROBUST WITH
EFFECTIVE DEEP LAYER SHEAR OVER 40 KTS (ACCORDING TO SPC
MESOANALYSES) AND RAP ANALYSES REVEALING A LONG STRAIGHT LINE
HODOGRAPH SUPPORTIVE OF SPLITTING SUPERCELLS. MLCAPE AND MUCAPE
VALUES ARE RAPIDLY GROWING AND NOW SIT NEAR 1000 J/KG AND 1500-2000
J/KG RESPECTIVELY... AND LOW LEVEL LAPSE RATES HAVE REACHED NEAR 8
C/KM. THESE FACTORS ALONG WITH DERIVED PARAMETERS INCLUDING THE
CRAVEN SIGSVR AND SUPERCELL COMPOSITE PARAMETER SUPPORT SUSTAINED
SUPERCELLS. PW VALUES ARE ABOVE NORMAL BUT NOT INCREDIBLY HIGH...
AND THIS MAY LIMIT COVERAGE SOMEWHAT INITIALLY... BUT ALL
INDICATIONS ARE THAT CONVECTION WILL GROW AND CONGEAL INTO A LINEAR
MCS OR OR MULTICELL CLUSTERS AFFECTING A LARGER AREA. DAMAGING
STRAIGHT LINE WINDS AND LARGE HAIL STILL LOOK TO BE THE PRIMARY
THREATS... GIVEN THE LONG STRAIGHT HODOGRAPH AND FAT CAPE IN THE 0C
TO -30C LAYER WITH CONVECTION ALLOWING MODELS INDICATING STRONG
UPDRAFTS. INTENSE TORNADOES LOOK TO BE LESS LIKELY WITH LCL HEIGHTS
UP TO 1000 M CURRENTLY AND SOMEWHAT MARGINAL STORM RELATIVE HELICITY
VALUES... BUT A FEW TORNADOES REMAIN POSSIBLE IN THIS ENVIRONMENT.
STORM MOTION IS EXPECTED TO BE 40-50 MPH FROM THE WSW... AND THESE
TRANSLATIONAL SPEEDS WILL EXACERBATE THE EFFECTS OF ANY STRONG WINDS
ASSOCIATED WITH INDIVIDUAL STORMS. STRONG TO SEVERE CONVECTION NOW
OVER THE GSP CWA WILL CONTINUE TO EXPAND TO THE NE... SO EXPECT THE
GREATEST SEVERE RISK OVER CENTRAL NC TO BE BETWEEN 4 PM AND 8 PM...
GRADUALLY TAPERING DOWN AFTERWARD... WITH LITTLE MORE THAN ISOLATED
TRAILING SHOWERS AFTER 11 PM.
AFTER MIDNIGHT: THE COLD FRONT WILL MOVE ESE THROUGH CENTRAL NC
BETWEEN MIDNIGHT AND 6 AM... AND EXPECT CLEARING SKIES WITH THE
ONSET OF DOWNSLOPE LOW LEVEL FLOW AND A DRYING COLUMN. STILL EXPECT
LOWS FROM AROUND 50 IN THE NW TO AROUND 60 SE AS COOLER AIR RUSHES
IN LATE. -GIH
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 345 AM MONDAY...
DRY CONDITIONS WILL PREVAIL IN THE WAKE OF THE COLD FRONT TUE/TUE
NIGHT...WITH HIGHS IN THE UPPER 60S TO LOWER 70S AND LOWS MID/UPPER
40S TO PERHAPS 50F FAR SE COASTAL PLAIN WED MORNING. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
WEDNESDAY THROUGH THURSDAY NIGHT...DRY CONDITIONS WILL PERSIST ON
WEDNESDAY AS HIGH PRESSURE ACROSS THE SOUTHEAST US GRADUALLY SLIPS
OFFSHORE WEDNESDAY MORNING/EARLY AFTERNOON. ANOTHER COLD FRONT WILL
APPROACH THE AREA LATE WEDNESDAY INTO THURSDAY. HOWEVER...LIMITED
MOISTURE RETURN AHEAD OF THIS SYSTEM WILL KEEP PRECIP CHANCES
MINIMAL. NEVERTHELESS...WILL KEEP A SLIGHT CHANCE POP IN THE
FORECAST FOR WEDNESDAY NIGHT/EARLY THURSDAY...BUT MOST PLACES WILL
LIKELY STAY DRY AND THOSE THAT SEE PRECIP WILL HAVE MEAGER AMOUNTS.
HIGHS ON WEDNESDAY WILL RISE INTO THE MID/UPPER 70S...WHILE ON
THURSDAY HIGHS WILL RANGE FROM THE UPPER 60S ACROSS THE NORTH
(EARLIER FRONTAL PASSAGE) TO THE MID 70S FURTHER SOUTH. OVERNIGHT
LOWS WILL GENERALLY BE IN THE MID/UPPER 40S TO LOWER 50S (COOLEST
THURSDAY NIGHT BEHIND THE FRONT).
FRIDAY THROUGH MONDAY...UNCERTAINTY REMAINS FAIRLY HIGH WITH RESPECT
TO THE END OF THE WEEK AND ESPECIALLY INTO THE WEEKEND. THE OVERALL
PATTERN INDICATES THE AFOREMENTIONED COLD FRONT WILL STALL JUST
SOUTH OF THE REGION FOR THE END OF THE WEEK. THEN...AS A SOUTHERN
STREAM SYSTEM APPROACHES...MULTIPLE WAVES OF LOW PRESSURE WILL RIDE
ALONG THIS BOUNDARY...SPREADING PRECIP BACK INTO THE AREA.
HOWEVER...AS CAN BE EXPECTED THIS FAR OUT...DETAILS HAVE YET TO BE
WORKED OUT. REGARDLESS...WILL SHOW POPS EARLY IN THE WEEKEND WITH...
AS OF NOW AT LEAST...DRIER CONDITIONS BY SUNDAY. MONDAY ALSO LOOKS
TO BE DRY...BUT ANOTHER SYSTEM IS PROGGED TO BE ON OUR DOORSTEP BY
LATE MONDAY/MONDAY NIGHT. TEMPS WILL GENERALLY BE NEAR TO SLIGHTLY
BELOW NORMAL THROUGH THE TIME FRAME.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 1230 PM MONDAY...
EARLIER MVFR CIGS AT INT/GSO/RDU/FAY HAVE SCATTERED OUT... AND
EXPECT RWI TO FOLLOW SUIT AND BECOME SCT IN THE NEXT HOUR. SCATTERED
STORMS ARE EXPECTED TO FORM OVER NRN GA AND UPSTATE SC THEN MOVE TO
THE NE... LIKELY AFFECTING INT/GSO 19Z-23Z... RDU 20Z-00Z... AND
FAY/RWI 21Z-01Z. VFR CONDITIONS WILL GENERALLY CONTINUE FOR THE NEXT
24 HRS... BUT CIGS/VSBYS IN AND NEAR STORMS WILL DROP TO MVFR OR
BRIEFLY IFR. ENHANCED WIND GUSTS OVER 50 MPH AND HAIL GREATER THAN 1
INCH IN DIAMETER REMAIN POSSIBLE WITH THESE SCATTERED STORMS. EVEN
OUTSIDE OF STORMS... WINDS FROM THE SW AT 10-15 KTS GUSTING TO 20-30
KTS WILL PERSIST... VEERING AROUND TO WESTERLY WITH DIMINISHING
GUSTS AFTER PASSAGE OF A COLD FRONT AFTER 04Z. A SHORT PERIOD OF
MVFR CIGS ARE POSSIBLE WITH FRONTAL PASSAGE... BUT GENERALLY WE
EXPECT VFR CONDITIONS LATE TONIGHT THROUGH THE END OF THE TAF VALID
PERIOD WITH MOSTLY CLEAR SKIES.
LOOKING BEYOND 18Z TUE... VFR CONDITIONS SHOULD HOLD THROUGH WED AS
HIGH PRESSURE BUILDS OVER THE REGION. A FEW HOURS OF SUB-VFR
CIGS/VSBYS WITH A FEW SHOWERS ARE POSSIBLE WED EVENING/NIGHT INTO
EARLY THU AS A DISTURBANCE MOVES QUICKLY ACROSS THE DEEP SOUTH AND
SOUTHEAST STATES. VFR CONDITIONS AND COOLER WEATHER WILL FOLLOW FOR
LATE THU INTO SAT. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...VINCENT
LONG TERM...KRD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
230 PM EDT MON APR 20 2015
.SYNOPSIS...A COLD FRONT WILL TRACK EAST ACROSS THE REGION TONIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST LATE TONIGHT THROUGH
TUESDAY... THEN SHIFT OFF THE COAST TUESDAY NIGHT INTO WEDNESDAY.
A COLD FRONT WILL APPROACH FROM THE NORTH WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...
NOW THROUGH THIS EVENING: NUMEROUS SIGNALS CONTINUE TO SUPPORT AN
ENHANCED RISK OF SEVERE STORMS IN CENTRAL NC. HEATING/MIXING
DISSIPATED THE WEAK CAP OVER THE REGION NEARLY 2 HOURS AGO...
YIELDING EXPLOSIVE CONVECTION TO OUR SW OVER NE GA AND UPSTATE SC.
SEE NO REASON WHY THIS WON`T CONTINUE TO EXPAND NORTHEASTWARD TOWARD
CENTRAL NC OVER THE NEXT FEW HOURS. KINEMATICS REMAIN ROBUST WITH
EFFECTIVE DEEP LAYER SHEAR OVER 40 KTS (ACCORDING TO SPC
MESOANALYSES) AND RAP ANALYSES REVEALING A LONG STRAIGHT LINE
HODOGRAPH SUPPORTIVE OF SPLITTING SUPERCELLS. MLCAPE AND MUCAPE
VALUES ARE RAPIDLY GROWING AND NOW SIT NEAR 1000 J/KG AND 1500-2000
J/KG RESPECTIVELY... AND LOW LEVEL LAPSE RATES HAVE REACHED NEAR 8
C/KM. THESE FACTORS ALONG WITH DERIVED PARAMETERS INCLUDING THE
CRAVEN SIGSVR AND SUPERCELL COMPOSITE PARAMETER SUPPORT SUSTAINED
SUPERCELLS. PW VALUES ARE ABOVE NORMAL BUT NOT INCREDIBLY HIGH...
AND THIS MAY LIMIT COVERAGE SOMEWHAT INITIALLY... BUT ALL
INDICATIONS ARE THAT CONVECTION WILL GROW AND CONGEAL INTO A LINEAR
MCS OR OR MULTICELL CLUSTERS AFFECTING A LARGER AREA. DAMAGING
STRAIGHT LINE WINDS AND LARGE HAIL STILL LOOK TO BE THE PRIMARY
THREATS... GIVEN THE LONG STRAIGHT HODOGRAPH AND FAT CAPE IN THE 0C
TO -30C LAYER WITH CONVECTION ALLOWING MODELS INDICATING STRONG
UPDRAFTS. INTENSE TORNADOES LOOK TO BE LESS LIKELY WITH LCL HEIGHTS
UP TO 1000 M CURRENTLY AND SOMEWHAT MARGINAL STORM RELATIVE HELICITY
VALUES... BUT A FEW TORNADOES REMAIN POSSIBLE IN THIS ENVIRONMENT.
STORM MOTION IS EXPECTED TO BE 40-50 MPH FROM THE WSW... AND THESE
TRANSLATIONAL SPEEDS WILL EXACERBATE THE EFFECTS OF ANY STRONG WINDS
ASSOCIATED WITH INDIVIDUAL STORMS. STRONG TO SEVERE CONVECTION NOW
OVER THE GSP CWA WILL CONTINUE TO EXPAND TO THE NE... SO EXPECT THE
GREATEST SEVERE RISK OVER CENTRAL NC TO BE BETWEEN 4 PM AND 8 PM...
GRADUALLY TAPERING DOWN AFTERWARD... WITH LITTLE MORE THAN ISOLATED
TRAILING SHOWERS AFTER 11 PM.
AFTER MIDNIGHT: THE COLD FRONT WILL MOVE ESE THROUGH CENTRAL NC
BETWEEN MIDNIGHT AND 6 AM... AND EXPECT CLEARING SKIES WITH THE
ONSET OF DOWNSLOPE LOW LEVEL FLOW AND A DRYING COLUMN. STILL EXPECT
LOWS FROM AROUND 50 IN THE NW TO AROUND 60 SE AS COOLER AIR RUSHES
IN LATE. -GIH
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 345 AM MONDAY...
DRY CONDITIONS WILL PREVAIL IN THE WAKE OF THE COLD FRONT TUE/TUE
NIGHT...WITH HIGHS IN THE UPPER 60S TO LOWER 70S AND LOWS MID/UPPER
40S TO PERHAPS 50F FAR SE COASTAL PLAIN WED MORNING. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 120 AM MONDAY...
DRY WEATHER EXPECTED WEDNESDAY AND THURSDAY.
HIGH CONFIDENCE FORECAST FOR MID WEEK AS HIGH PRESSURE WILL DOMINATE
AND BRING DRY WEATHER WITH SEASONABLY COOL TEMPERATURES WEDNESDAY
AND THURSDAY.
CONFIDENCE RAPIDLY DECREASES IN THE FORECAST BY FRIDAY THROUGH THE
WEEKEND AS MODELS SHOW SPREAD WITH HANDLING THE PROGRESSIVELY MOVING
SOUTHERN STREAM SYSTEM THAT MAY AFFECT OUR REGION AS EARLY AS
FRIDAY. JUST HOW THIS SYSTEM INTERACTS WITH THE POLAR JET AND THE
ASSOCIATED LOW LEVEL BOUNDARY WILL DETERMINE HOW QUICKLY THIS SYSTEM
MOVES AND HOW FAR NORTH THE SIGNIFICANT RAINFALL REACHES INTO THE MID-
ATLANTIC STATES. FOR NOW... WE WILL CARRY A CHANCE OF SHOWERS FOR
THE WEEKEND (CENTERED ON SATURDAY INTO SATURDAY NIGHT).
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 1230 PM MONDAY...
EARLIER MVFR CIGS AT INT/GSO/RDU/FAY HAVE SCATTERED OUT... AND
EXPECT RWI TO FOLLOW SUIT AND BECOME SCT IN THE NEXT HOUR. SCATTERED
STORMS ARE EXPECTED TO FORM OVER NRN GA AND UPSTATE SC THEN MOVE TO
THE NE... LIKELY AFFECTING INT/GSO 19Z-23Z... RDU 20Z-00Z... AND
FAY/RWI 21Z-01Z. VFR CONDITIONS WILL GENERALLY CONTINUE FOR THE NEXT
24 HRS... BUT CIGS/VSBYS IN AND NEAR STORMS WILL DROP TO MVFR OR
BRIEFLY IFR. ENHANCED WIND GUSTS OVER 50 MPH AND HAIL GREATER THAN 1
INCH IN DIAMETER REMAIN POSSIBLE WITH THESE SCATTERED STORMS. EVEN
OUTSIDE OF STORMS... WINDS FROM THE SW AT 10-15 KTS GUSTING TO 20-30
KTS WILL PERSIST... VEERING AROUND TO WESTERLY WITH DIMINISHING
GUSTS AFTER PASSAGE OF A COLD FRONT AFTER 04Z. A SHORT PERIOD OF
MVFR CIGS ARE POSSIBLE WITH FRONTAL PASSAGE... BUT GENERALLY WE
EXPECT VFR CONDITIONS LATE TONIGHT THROUGH THE END OF THE TAF VALID
PERIOD WITH MOSTLY CLEAR SKIES.
LOOKING BEYOND 18Z TUE... VFR CONDITIONS SHOULD HOLD THROUGH WED AS
HIGH PRESSURE BUILDS OVER THE REGION. A FEW HOURS OF SUB-VFR
CIGS/VSBYS WITH A FEW SHOWERS ARE POSSIBLE WED EVENING/NIGHT INTO
EARLY THU AS A DISTURBANCE MOVES QUICKLY ACROSS THE DEEP SOUTH AND
SOUTHEAST STATES. VFR CONDITIONS AND COOLER WEATHER WILL FOLLOW FOR
LATE THU INTO SAT. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
116 PM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH THIS EVENING AND MOVE OFFSHORE LATE
MONDAY NIGHT. HIGH PRESSURE BUILDS OVER THE REGION TUESDAY AND
WEDNESDAY. A WEAK COLD FRONT WILL CROSS THE AREA THURSDAY. ANOTHER
DISTURBANCE WILL AFFECT THE REGION NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 110 PM MONDAY...STRONG SUBSIDENCE ACROSS THE REGION FOR MUCH
OF THE DAY THUS FAR...BUT A GOOD CUMULUS FIELD DEVELOPING ACROSS
THE REGION NOW. PER LATEST RUNS OF THE 3KM HRRR AND RAP...EXPECT
SHOWERS/TSTMS TO APPROACH OUR WESTERN COUNTIES AROUND 21Z-23Z WITH
ADDITIONAL SHOWERS/TSTMS DEVELOPING FURTHER EAST NEAR THE COAST
LATER IN THE EVENING. INSTABILITY SHOULD INCREASE DURING THE LATE
AFTERNOON/EVENING WITH GOOD SOLAR HEATING. MINIMAL CHANGES TO
CURRENT FORECAST AT THIS TIME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 430 AM MONDAY...THE FRONT WILL CROSS THE AREA EARLY
TUESDAY. THE CHALLENGE WILL BE THE EXTENT OF PRECIPITATION AHEAD
OF THE FRONT AND IF STORMS WILL DEVELOP/MOVE INTO THE AREA. GIVEN
THE TIMING OF THE FRONT...FEEL THE CHANCE OF THUNDERSTORMS WILL BE
LIMITED AS PEAK HEATING WILL HAVE ALREADY OCCURRED.
FURTHERMORE...THE BEST SYNOPTIC FORCING...SFC FRONT AND PEAK
HEATING WILL NOT COEXIST GIVING THIS SCENARIO A LOW CONFIDENCE
LEVEL IN TERMS OF THUNDERSTORM DEVELOPMENT AND SUBSTAINABILITY.
GIVEN MARGINAL LIFT...INSTABILITY AND SHEAR...WE CAN NOT RULE OUT
DISCRETE THUNDERSTORMS POSSIBLY BECOMING LINEAR IN NATURE DURING
THE EVENING HOURS...BUT THE OVERALL SPATIAL EXTENT LOOKS MINIMAL.
BY THE TIME THE MID-LEVEL DRY AIR BECOMES BETTER
SATURATED...INSTABILITY WILL HAVE DIMINISH QUITE A BIT. IF THE
FRONT MOVES A BIT FASTER THAN ANTICIPATED OR THERE IS BETTER
LIFT/SATURATION AHEAD OF THE FRONT...THEN THERE MAY BE BETTER
SPATIAL COVERAGE OF THUNDERSTORMS. AT THIS TIME...WE FEEL ANY
ACTIVITY WILL WANE AS IT CROSSES EASTERN NC DURING THE EVENING
HOURS. KEPT A CHANCE POP IN FOR THE TIME BEING. PRECIPITATION
CHANCES SHOULD DIMINISH AFTER 10Z WITH THE FRONT MOVING THROUGH BY
12Z. LOWS IN THE LOW 60S INLAND TO MID 60S ALONG THE BEACHES.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 545 AM MON...ONLY MINOR CHANGES FOR THE LONG TERM FORECAST
WITH MODELS IN MODEST AGREEMENT THROUGH THE MEDIUM RANGE. FOR
TUESDAY/WEDNESDAY...SEASONABLY MILD CONDITIONS WITH WARM DAYS AND
COOL NIGHTS EXPECTED AS ZONAL FLOW BRINGS NEAR CLIMO TEMPS AND DRY
WEATHER TO THE REGION. HIGHS SHOULD GENERALLY BE IN THE 70S WITH
LOWS IN THE UPR 40S TO MID 50S.
WEDNESDAY NIGHT/THURSDAY...SOME MINOR DIFFERENCES IN MOISTURE
AVAILABILITY WITH COLD FRONT THAT WILL SAG INTO THE AREA ON
THURSDAY. HAVE CONTINUED TO SIDE WITH DRIER SOLN WITH GFS
APPEARING TO HAVE A WET BIAS. DETERMINISTIC ECMWF MORE IN LINE
WITH ITS ENSEMBLE MEAN IN KEEPING THE AREA DRY...THEREFORE HAVE NO
HIGHER THAN A 20 POP LATE WED NIGHT INTO THUR. ANOTHER SEASONABLE
DAY ON THUR WITH HIGHS IN THE 70S AS WINDS SHIFT NORTHWESTERLY
BEHIND THE FRONT.
THURSDAY NIGHT/FRIDAY...DRY WEATHER BEHIND THE FRONT WITH SUNNY DRY
AND COOLER WEATHER. SLIGHTLY BELOW CLIMO EXPECTED WITH LOWS IN THE
40S TO NEAR 50 AND HIGHS IN THE MID 60S TO NEAR 70.
FRIDAY NIGHT/SATURDAY...A PRONOUNCED SOUTHERN STREAM SYSTEM MAY
AFFECT THE AREA THIS WEEKEND. SIGNIFICANT TIMING DIFFERENCES EXIST
THIS FAR OUT HOWEVER AND MAINTAINED THE SMALL CHANCE POPS IN THE
FCST. TEMPS WILL LIKELY REMAIN BELOW CLIMO DUE TO THE INCREASED
CLOUDS AND PRECIP WITH THE AREA ON THE COOL SIDE OF THE FRONTAL
BOUNDARY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 18Z TUESDAY/...
AS OF 115 PM MONDAY...NICE CUMULUS FIELD HAS DEVELOPED ACROSS THE
REGION THIS AFTERNOON WITH VFR CONDITIONS PREVAILING. GUIDANCE
INDICATES PERHAPS A BRIEF PERIOD OF MVFR CEILINGS IN SCATTERED
CONVECTION LATE TONIGHT. COLD FRONT MOVES OFFSHORE BETWEEN 06Z AND
12Z WITH DRIER AIR MOVING IN AND VFR CONDITIONS EXPECTED TO
PREVAIL THROUGH TUESDAY.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 550 AM MON...HIGH PRESSURE BUILDS ACROSS EASTERN NC TUESDAY
INTO WEDNESDAY YIELDING MOSTLY VFR CONDITIONS. A WEAK FRONT WILL
MOVE SOUTH INTO EASTERN NC THURSDAY BUT WITH LIMITED MOISTURE SO
EXPECT MOSTLY VFR CONDITIONS THURSDAY. A BETTER CHANCE FOR PRECIP
ARRIVES NEXT WEEKEND.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 115 PM MONDAY...SW WINDS CONTINUE AT 10 TO 15 KNOTS WITH
SOME GUSTS TO 20 KNOTS OVER THE CENTRAL AND NORTHERN WATERS. SEAS
5 TO 7 FEET NORTH AND 3 TO 6 FEET SOUTH. NO CHANGES NEEDED TO THE
MARINE FORECAST AT THIS TIME.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 550 AM MON...SEAS WILL REMAIN ELEVATED INTO TUESDAY MORNING
AND CURRENT SCA FOR ALL COASTAL WATERS WILL REMAIN IN EFFECT UNTIL
12Z TUESDAY. HIGH PRESSURE WILL BUILD OVER THE NC WATERS TUESDAY
INTO WEDNESDAY WITH WINDS SHIFTING MORE WESTERLY, 5-15 KT. SEAS
WILL DIMINISH TO 2-4 FT TUESDAY NIGHT THROUGH WEDNESDAY. A COLD
FRONT WILL MOVE SOUTH INTO THE NORTHERN WATERS THURSDAY AND SHIFT
SOUTH OF THE WATERS BY THURSDAY NIGHT. WINDS VEER NORTHWEST BEHIND
THE FRONT BUT REMAIN 5-15 KT WITH PLEASANT BOATING CONDITIONS
EXPECTED AND SEAS AROUND 2 TO 3 FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR AMZ150-152-154-
156-158.
&&
$$
SYNOPSIS...CTC/LEP
NEAR TERM...CTC
SHORT TERM...LEP
LONG TERM...DAG
AVIATION...TL/CTC
MARINE...CTC/DAG
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
954 AM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH MONDAY AND MOVE OFFSHORE LATE MONDAY
NIGHT. HIGH PRESSURE BUILDS OVER THE REGION TUESDAY AND WEDNESDAY.
A WEAK COLD FRONT WILL CROSS THE AREA THURSDAY. ANOTHER
DISTURBANCE WILL AFFECT THE REGION NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 950 AM MONDAY...GOOD SUBSIDENCE ACROSS THE REGION THIS
MORNING IN THE WAKE OF LAST NIGHT`S CONVECTION AND PRECIPITATION.
LOTS OF LEFT OVER LOW CLOUDS...BUT THEY SHOULD SCOUT OUT AS
SOUTHWEST FLOW INCREASES. SOME STRONG/SEVERE CONVECTION AROUND THE
CHARLOTTE AREA CURRENTLY AND WILL WATCH THE EVOLUTION OF THIS
ACTIVITY INTO THE AFTERNOON. LATEST 3KM HRRR SHOWS THIS CONVECTION
MOVING NORTHEAST AND DISSIPATING WITH ADDITIONAL STORMS DEVELOPING
IN OUR CWA IN THE 20Z-22Z TIME FRAME. LOOKS WARM THIS AFTERNOON
AHEAD OF THE FRONT WITH HIGHS INTO THE 80S AWAY FROM THE COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 430 AM MONDAY...THE FRONT WILL CROSS THE AREA EARLY
TUESDAY. THE CHALLENGE WILL BE THE EXTENT OF PRECIPITATION AHEAD
OF THE FRONT AND IF STORMS WILL DEVELOP/MOVE INTO THE AREA. GIVEN
THE TIMING OF THE FRONT...FEEL THE CHANCE OF THUNDERSTORMS WILL BE
LIMITED AS PEAK HEATING WILL HAVE ALREADY OCCURRED.
FURTHERMORE...THE BEST SYNOPTIC FORCING...SFC FRONT AND PEAK
HEATING WILL NOT COEXIST GIVING THIS SCENARIO A LOW CONFIDENCE
LEVEL IN TERMS OF THUNDERSTORM DEVELOPMENT AND SUBSTAINABILITY.
GIVEN MARGINAL LIFT...INSTABILITY AND SHEAR...WE CAN NOT RULE OUT
DISCRETE THUNDERSTORMS POSSIBLY BECOMING LINEAR IN NATURE DURING
THE EVENING HOURS...BUT THE OVERALL SPATIAL EXTENT LOOKS MINIMAL.
BY THE TIME THE MID-LEVEL DRY AIR BECOMES BETTER
SATURATED...INSTABILITY WILL HAVE DIMINISH QUITE A BIT. IF THE
FRONT MOVES A BIT FASTER THAN ANTICIPATED OR THERE IS BETTER
LIFT/SATURATION AHEAD OF THE FRONT...THEN THERE MAY BE BETTER
SPATIAL COVERAGE OF THUNDERSTORMS. AT THIS TIME...WE FEEL ANY
ACTIVITY WILL WANE AS IT CROSSES EASTERN NC DURING THE EVENING
HOURS. KEPT A CHANCE POP IN FOR THE TIME BEING. PRECIPITATION
CHANCES SHOULD DIMINISH AFTER 10Z WITH THE FRONT MOVING THROUGH BY
12Z. LOWS IN THE LOW 60S INLAND TO MID 60S ALONG THE BEACHES.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 545 AM MON...ONLY MINOR CHANGES FOR THE LONG TERM FORECAST
WITH MODELS IN MODEST AGREEMENT THROUGH THE MEDIUM RANGE. FOR
TUESDAY/WEDNESDAY...SEASONABLY MILD CONDITIONS WITH WARM DAYS AND
COOL NIGHTS EXPECTED AS ZONAL FLOW BRINGS NEAR CLIMO TEMPS AND DRY
WEATHER TO THE REGION. HIGHS SHOULD GENERALLY BE IN THE 70S WITH
LOWS IN THE UPR 40S TO MID 50S.
WEDNESDAY NIGHT/THURSDAY...SOME MINOR DIFFERENCES IN MOISTURE
AVAILABILITY WITH COLD FRONT THAT WILL SAG INTO THE AREA ON
THURSDAY. HAVE CONTINUED TO SIDE WITH DRIER SOLN WITH GFS
APPEARING TO HAVE A WET BIAS. DETERMINISTIC ECMWF MORE IN LINE
WITH ITS ENSEMBLE MEAN IN KEEPING THE AREA DRY...THEREFORE HAVE NO
HIGHER THAN A 20 POP LATE WED NIGHT INTO THUR. ANOTHER SEASONABLE
DAY ON THUR WITH HIGHS IN THE 70S AS WINDS SHIFT NORTHWESTERLY
BEHIND THE FRONT.
THURSDAY NIGHT/FRIDAY...DRY WEATHER BEHIND THE FRONT WITH SUNNY DRY
AND COOLER WEATHER. SLIGHTLY BELOW CLIMO EXPECTED WITH LOWS IN THE
40S TO NEAR 50 AND HIGHS IN THE MID 60S TO NEAR 70.
FRIDAY NIGHT/SATURDAY...A PRONOUNCED SOUTHERN STREAM SYSTEM MAY
AFFECT THE AREA THIS WEEKEND. SIGNIFICANT TIMING DIFFERENCES EXIST
THIS FAR OUT HOWEVER AND MAINTAINED THE SMALL CHANCE POPS IN THE
FCST. TEMPS WILL LIKELY REMAIN BELOW CLIMO DUE TO THE INCREASED
CLOUDS AND PRECIP WITH THE AREA ON THE COOL SIDE OF THE FRONTAL
BOUNDARY.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 12Z TUESDAY/...
AS OF 700 AM MONDAY...THE BULK OF THE PRECIPITATION HAS MOVED
OFFSHORE AT THIS TIME. LOW LEVEL CLOUDS WILL SLOWLY ERODE GIVING
WAY TO SCATTERED CU BY AFTERNOON. GUSTY SOUTHWEST WINDS CAN BE
EXPECTED AS A FRONT APPROACHES FROM THE WEST. GUSTS EXPECTED AOB
25KTS DURING THE AFTERNOON/EARLY EVENING HOURS. CLOUDS MAY START
TO BUILD IN WEST TO EAST JUST AHEAD OF THE FRONT. SHOWERS/STORMS
ASSOCIATED WITH THIS FRONT LOOKS LIMITED. SO KEPT THE MENTION OUT
OF THE TAFS FOR NOW. WINDS WILL VEER TO THE NW BEHIND THE FRONT BY
TUESDAY MORNING. FOG/STRATUS DOES NOT LOOK PROBABLY OVERNIGHT
MONDAY GIVEN THE MIX BL AND SUFFICIENT DRY AIR.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 550 AM MON...HIGH PRESSURE BUILDS ACROSS EASTERN NC TUESDAY
INTO WEDNESDAY YIELDING MOSTLY VFR CONDITIONS. A WEAK FRONT WILL
MOVE SOUTH INTO EASTERN NC THURSDAY BUT WITH LIMITED MOISTURE SO
EXPECT MOSTLY VFR CONDITIONS THURSDAY. A BETTER CHANCE FOR PRECIP
ARRIVES NEXT WEEKEND.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 950 AM MONDAY...SCA HAS EXPIRED OVER PAMLICO SOUND AS WINDS
HAVE DROPPED OFF TO 10 TO 15 KNOTS. EXPECT S/SW WINDS TO INCREASE
TO 15 TO 20 KNOTS BY MIDDAY. SEAS ARE IN THE 5 TO 8 FOOT RANGE.
CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE AND NO CHANGES NEEDED.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 550 AM MON...SEAS WILL REMAIN ELEVATED INTO TUESDAY MORNING
AND CURRENT SCA FOR ALL COASTAL WATERS WILL REMAIN IN EFFECT UNTIL
12Z TUESDAY. HIGH PRESSURE WILL BUILD OVER THE NC WATERS TUESDAY
INTO WEDNESDAY WITH WINDS SHIFTING MORE WESTERLY, 5-15 KT. SEAS
WILL DIMINISH TO 2-4 FT TUESDAY NIGHT THROUGH WEDNESDAY. A COLD
FRONT WILL MOVE SOUTH INTO THE NORTHERN WATERS THURSDAY AND SHIFT
SOUTH OF THE WATERS BY THURSDAY NIGHT. WINDS VEER NORTHWEST BEHIND
THE FRONT BUT REMAIN 5-15 KT WITH PLEASANT BOATING CONDITIONS
EXPECTED AND SEAS AROUND 2 TO 3 FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR AMZ150-152-154-
156-158.
&&
$$
SYNOPSIS...CTC/LEP
NEAR TERM...CTC
SHORT TERM...LEP
LONG TERM...DAG
AVIATION...DAG/TL/LEP
MARINE...CTC/DAG
AREA FORECAST DISCUSSION
NWS RALEIGH NC
756 AM EDT MON APR 20 2015
.SYNOPSIS...A COLD FRONT WILL APPROACH THE MOUNTAINS FROM THE WEST
THIS AFTERNOON...THEN TRACK EAST ACROSS THE CAROLINAS THIS EVENING.
HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE SOUTHWEST TONIGHT
AND TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 745 AM MONDAY...
UPDATE: THE TN VALLEY MCS HAS PERSISTED LONGER THAN PREVIOUSLY
ANTICIPATED. ALTHOUGH THE ENVIRONMENT DOWNSTREAM OF THIS FEATURE IS
MARGINALLY UNSTABLE BY VIRTUE OF RELATIVELY STEEP MID-LEVEL LAPSE
RATES ATOP A SEASONABLY MOIST WARM-SECTOR AIRMASS...ADDITIONAL (I.E.
SUPPLEMENTAL) FORCING FOR ASCENT IS LARGELY ABSENT. AS A RESULT...
ADDITIONAL WEAKENING OF THE MCS SHOULD ACCELERATE THE WEAKENING
PROCESS AND RESULT IN RAPID DECAY...SIMILAR TO 10Z HRRR SIM REF
FORECASTS. REGARDLESS...HAVE UPDATED THE FORECAST TO INTRODUCE A
SLIGHT CHANCE OF SHOWERS THIS MORNING TO ACCOUNT FOR THE POSSIBILITY
OF A SLOWER WEAKENING TREND. -VINCENT
OVERVIEW: A LOW-LEVEL TROUGH /WEAK WARM FRONT/...ASSOCIATED WITH A
DEEPENING SFC CYCLONE ATTENDANT A POTENT UPPER TROUGH DIGGING SE
INTO THE UPPER GREAT LAKES...WILL LIFT NORTHWARD THROUGH THE
DELMARVA THIS MORNING AND NORTHEAST ALONG THE MID-ATLANTIC COAST
THIS AFT/EVE INTO TONIGHT. MEANWHILE...A COLD FRONT (ATTENDANT THE
AFOREMENTIONED CYCLONE) TRACKING EASTWARD THROUGH THE TN VALLEY THIS
MORNING WILL PROGRESS ACROSS THE SOUTHERN APPALACHIANS LATE THIS
AFTERNOON...THEN TRACK EAST ACROSS THE CAROLINAS THIS EVENING INTO
TONIGHT.
PRECIPITATION: THE RECENT INCREASE IN CONVECTIVE INTENSITY OVER THE
COASTAL PLAIN IS ASSOCIATED WITH ENHANCED LOW-LEVEL CONVERGENCE
/BACKED LOW-LEVEL FLOW/ AND THE ADVECTION OF A HIGHER THETA-E
AIRMASS INTO EASTERN NC...APPARENTLY IN RESPONSE TO DPVA ATTENDANT
THE NEGATIVELY TILTED SHORTWAVE CURRENTLY TRACKING NE ACROSS THE
REGION. NOW THAT THIS ACTIVITY HAS EXITED CENTRAL NC...EXPECT DRY
CONDITIONS TO PREVAIL THROUGH SUNRISE IN ASSOC/W SUBSIDENCE IN THE
WAKE OF THE AFOREMENTIONED SHORTWAVE AND...FOR THE REMAINDER OF THE
MORNING...A LACK OF FORCING DRYING ALOFT COMBINED WITH DRYING ALOFT
ASSOC/W THE ADVECTION OF A MODIFIED ELEVATED MIXED LAYER INTO THE
REGION FROM THE SOUTHWEST. UNCERTAINTY INCREASES BY EARLY AFTERNOON
REGARD TO WHETHER OR NOT THE ONGOING TN VALLEY MCS WILL CROSS THE
SOUTHERN APPALACHIANS AND RESULT IN A POTENTIAL FOR CONVECTION IN
THE FAR WESTERN PIEDMONT BETWEEN 15-18Z. THE LATEST HIGH-RES CAMS
SUGGEST THAT THE MCS WILL DECAY ON APPROACH TO THE MOUNTAINS ~12Z AS
THE THERMODYNAMIC ENVIRONMENT BECOMES LESS FAVORABLE (I.E.
INCREASING CINH). EVEN IF THE MCS DECAYS PRIOR TO CROSSING THE
MOUNTAINS...THE PRESENCE OF AN MCV AND/OR LINGERING CONVECTIVE
DEBRIS/OUTFLOW WOULD INTRODUCE CONSIDERABLE UNCERTAINTY TO THE
CONVECTIVE FORECAST THIS AFTERNOON. EVEN IF ONE ASSUMES THE
AFOREMENTIONED FEATURES ARE ABSENT...THE CONVECTIVE FORECAST REMAINS
UNCERTAIN GIVEN A TEMPORAL/SPATIAL DISCONNECT BETWEEN THE BEST
SYNOPTIC FORCING (DPVA IN SW FLOW ALOFT BETWEEN 00-06Z)...THE BEST
LOW-LEVEL FOCUS (PRE-FRONTAL TROUGH IN THE WESTERN PIEDMONT BY
~00Z)...AND PEAK HEATING. WITH THE ABOVE IN MIND...WILL MAKE LITTLE
CHANGE TO THE PRIOR FORECAST AND INDICATE PRECIP CHANCES OF 40-50%
DURING THE LATE AFTERNOON AND EVENING...ENDING FROM WEST-EAST BY OR
SHORTLY AFTER MIDNIGHT.
SEVERE THREAT: MODERATE DESTABILIZATION (MLCAPE 1000-2000 J/KG) IS
EXPECTED TODAY IN ASSOC/W CLEARING SKIES...A MODIFIED ELEVATED MIXED
LAYER (CHARACTERIZED BY H7-H5 LAPSE RATES ON THE ORDER OF 6.5-7
C/KM)...AND SEASONABLY RICH LOW-LEVEL MOISTURE (DWPTS UPPER
50S/LOWER 60S) WITHIN AN INCREASINGLY WELL-MIXED WARM SECTOR
DOWNSTREAM OF THE APPROACHING COLD FRONT...WITH LITTLE IN THE WAY OF
A CAP /CINH/ PER LATEST FORECAST SOUNDINGS. ANY UPDRAFTS THAT
DEVELOP PRIOR TO ~21Z THIS AFTERNOON ARE UNLIKELY TO SURVIVE
ENTRAINMENT GIVEN A DRY AIRMASS ALOFT AND A GENERAL LACK OF FORCING
THROUGHOUT THE COLUMN...ASSUMING NO CONTRIBUTION FROM UPSTREAM
CONVECTION. BY LATE AFTERNOON...MODERATE/UNTAPPED INSTABILITY AND AN
ABSENCE OF CONVECTIVE INHIBITION ARE EXPECTED TO ALLOW CONVECTIVE
DEVELOPMENT ALONG THE COLD FRONT /PRE-FRONTAL TROUGH/ PROGRESSING
INTO THE FOOTHILLS...WITH UNIDIRECTIONAL DEEP-LAYER SHEAR SUFFICIENT
FOR SPLITTING SUPERCELLS AND UPSCALE GROWTH INTO A LINEAR MCS
THEREAFTER...THOUGH THE LATEST CONVECTION ALLOWING MODELS SUGGEST
MULTIPLE LINE SEGMENTS MAY DEVELOP RATHER THAN A SOLID LINE...WHICH
SEEMS REASONABLE GIVEN THE UNCERTAINTIES MENTIONED ABOVE. SHOULD
SPLITTING SUPERCELLS DEVELOP IN THE WESTERN PIEDMONT...LARGE HAIL
(UP TO GOLFBALL SIZE) AND DAMAGING WINDS WOULD BE POSSIBLE GIVEN
SPEEDY MID-LEVEL FLOW...MDT INSTABILITY AND STEEP MID-LEVEL LAPSE
RATES. FURTHER EAST...DAMAGING WINDS WOULD BE THE PRIMARY THREAT...
WITH SEVERE HAIL CONFINED TO ROTATING UPDRAFTS EMBEDDED WITHIN LINE
SEGMENTS. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 345 AM MONDAY...
DRY CONDITIONS WILL PREVAIL IN THE WAKE OF THE COLD FRONT TUE/TUE
NIGHT...WITH HIGHS IN THE UPPER 60S TO LOWER 70S AND LOWS MID/UPPER
40S TO PERHAPS 50F FAR SE COASTAL PLAIN WED MORNING. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 120 AM MONDAY...
DRY WEATHER EXPECTED WEDNESDAY AND THURSDAY.
HIGH CONFIDENCE FORECAST FOR MID WEEK AS HIGH PRESSURE WILL DOMINATE
AND BRING DRY WEATHER WITH SEASONABLY COOL TEMPERATURES WEDNESDAY
AND THURSDAY.
CONFIDENCE RAPIDLY DECREASES IN THE FORECAST BY FRIDAY THROUGH THE
WEEKEND AS MODELS SHOW SPREAD WITH HANDLING THE PROGRESSIVELY MOVING
SOUTHERN STREAM SYSTEM THAT MAY AFFECT OUR REGION AS EARLY AS
FRIDAY. JUST HOW THIS SYSTEM INTERACTS WITH THE POLAR JET AND THE
ASSOCIATED LOW LEVEL BOUNDARY WILL DETERMINE HOW QUICKLY THIS SYSTEM
MOVES AND HOW FAR NORTH THE SIGNIFICANT RAINFALL REACHES INTO THE MID-
ATLANTIC STATES. FOR NOW... WE WILL CARRY A CHANCE OF SHOWERS FOR
THE WEEKEND (CENTERED ON SATURDAY INTO SATURDAY NIGHT).
&&
.AVIATION /12Z MONDAY THROUGH THURSDAY/...
AS OF 700 AM MONDAY...
CONDITIONS WILL BECOME VFR BY MID/LATE MORNING. VSBYS SHOULD BECOME
VFR IN ALL AREAS THROUGH 09Z WITH THE LINE OF SHOWERS AND ISOLATED
STORMS FINALLY MOVING EAST OF KRWI SHORTLY. A SOUTH FLOW AT 10 MPH
WILL CONTINUE THROUGH DAYBREAK... THE GRADUALLY VEER TO THE SW AT 15-
20 MPH LATE MORNING AND AFTERNOON WITH GUSTS TO 30 MPH.
LOOKING FURTHER AHEAD...ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO FORM ALONG A COLD FRONT MONDAY
AFTERNOON OVER THE WESTERN SECTIONS OF THE AREA. THE CHANCE WILL
PUSH EAST WITH THE FRONT DURING THE LATE AFTERNOON AND EVENING.
OTHERWISE... VFR CONDITIONS WILL PREVAIL TONIGHT THROUGH THE END OF
THE WEEK DOMINATED BY HIGH PRESSURE BEGINNING TONIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...BADGETT
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
723 PM EDT TUE APR 21 2015
.SYNOPSIS...
A COLD FRONT WILL SWEEP ACROSS THE AREA WEDNESDAY...WITH HIGH
PRESSURE TAKING CONTROL THURSDAY AND FRIDAY. LOW PRESSURE TRACKS
SOUTH OF THE AREA THIS WEEKEND. DRIER SUNDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
720 PM UPDATE...INCREASED POPS IN THE COAL FIELDS SOME LATE
TONIGHT...WITH HRRR SHOWING CONVECTION HEADED INTO WESTERN KY
CROSSING SOUTHERN WV AND SOUTHWESTERN VA AS SHOWERS.
PREVIOUS DISCUSSION...MODELS SHOWING A DECENT PRESSURE GRADIENT REMAINING
OVERNIGHT...SO EXPECT THE WINDS TO CONTINUE STIRRING.
THEREFORE...WILL GO ABOVE MOS GUIDANCE ON TEMPERATURES TONIGHT
EVERYWHERE SOUTH OF THE COLD FRONT. MODELS SHOWING A DECENT BAND
OF SHOWERS DEVELOPING ALONG THE FRONT EARLY WEDNESDAY...SO WILL
INCREASE THE POPS AND ATTEMPT SOME BETTER TIMING OF THE
PRECIPITATION.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
COLD FRONT WILL BE WELL EAST OF THE REGION AT THE BEGINNING OF THE
PERIOD. HIGH PRESSURE SHOULD SLOWLY BUILD IN...BRINGING PRECIP
CHANCES TO AN END BY LATE WEDNESDAY NIGHT. THE HIGH SHOULD REMAIN
IN CONTROL OF THE WEATHER ACROSS THE AREA THROUGH THE REMAINDER OF
THE PERIOD.
MET/MAV NUMBERS WERE CLOSE WEDNESDAY NIGHT AND THURSDAY...WHILE THEY
DIFFER BY SEVERAL DEGREES AT SOME LOCATIONS THURSDAY NIGHT. WENT
CLOSER TO THE SLIGHTLY WARMER MAV NUMBERS AS MET NUMBERS APPEAR TOO
COLD. LAST OF ALL...WENT CLOSE TO HPC NUMBERS FOR HIGHS ON FRIDAY.
WITH THE COLD NIGHTTIME TEMPERATURES...ANY PRECIPITATION COULD MIX
WITH OR CHANGE TO SOME LIGHT SNOW ACROSS THE HIGHEST ELEVATIONS
WEDNESDAY NIGHT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MID LEVEL DISTURBANCE STREAKING ESE OVER STRONG BAROCLINIC ZONE
SATURDAY INTO SATURDAY NIGHT. FOR SUCH A TIGHT MOISTURE AND
TEMPERATURE GRADIENT STILL PROJECTED ON SATURDAY INTO SATURDAY
NIGHT...WE HAVE NOT MADE ANY HUGE CHANGES. OUR CHANCE POPS
WORK A BIT FURTHER NORTH SATURDAY AFTERNOON INTO SATURDAY NIGHT.
STILL HITTING SOUTHERN AND CENTRAL COUNTIES HARDER ON THE HIGHER
POPS FOR SATURDAY AFTERNOON INTO SATURDAY NIGHT.
FIGURING AREA WOULD REMAIN ON THE COOL SIDE OF THAT BOUNDARY
SATURDAY INTO SATURDAY NIGHT. STRONG 850 MB TEMPERATURE
GRADIENT ACROSS SOUTHERN WEST VIRGINIA AND EASTERN KENTUCKY. IF
RAIN SHOWERS DEVELOP ACROSS THE SOUTH AS PROJECTED...HAD TO GO LOWER
THAN MOS AND WPC TEMPERATURE GUIDANCE FOR MAXIMUM TEMPERATURE ON
SATURDAY. MAY ACTUALLY BE A FEW DEGREES WARMER IN THE EXTREME NORTH
WITH LESS PCPN COVERAGE.
THAT SYSTEM EXITS SOUTHERN COUNTIES LATE SATURDAY NIGHT INTO EARLY
SUNDAY. SO STILL HAVING MOSTLY DRY CONDITIONS SUNDAY INTO MONDAY.
CONFIDENCE LOWERS FOR MONDAY INTO TUESDAY WITH THE INTERACTION
BETWEEN THE LARGE CYCLONIC MID LEVEL CIRCULATION OFF THE NORTHEAST
COAST AND THE NEXT DISTURBANCE DROPPING SOUTHEAST FROM THE NORTHERN
PLAINS. 12Z ECMWF TAKING THAT ENERGY MUCH FURTHER SOUTH COMPARED TO
12Z GFS. DO HAVE POPS INCREASING BACK INTO CHANCE CATEGORY MONDAY
AFTERNOON INTO TUESDAY WITH SOME SNOW POSSIBLE ACROSS WV
MOUNTAINS.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
WINDS WILL BE DECREASING SOME TONIGHT...BUT DECENT PRESSURE
GRADIENT WILL KEEP AT LEAST SOME FLOW THROUGH THE NIGHT. A COLD
FRONT WILL CROSS LATE TONIGHT INTO WEDNESDAY...WITH SHOWERS.
THUNDER ALSO POSSIBLE MAINLY IN THE MOUNTAINS. HAVE MVFR VIS AND
CIG TIMED WITH THE BEST CHANCE OF PRECIP. COULD EVEN GET BRIEF
IFR. CURRENT SW TO W WINDS WILL SHIFT TO W TO NW THROUGH THE TAF
PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z THURSDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING OF LOWER CEILINGS AND SHOWERS WEDNESDAY
MORNING COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 00Z THURSDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED AT THIS TIME.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JSH/KTB/RPY
NEAR TERM...RPY/MZ
SHORT TERM...JSH
LONG TERM...KTB
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
435 AM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE EAST THROUGH THE GREAT LAKES AND OHIO
VALLEY TODAY. BREEZY TO WINDY CONDITIONS ARE EXPECTED ON TUESDAY
AHEAD OF A WEAK COLD FRONT. THIS FRONT WILL PUSH THROUGH THE
REGION TUESDAY NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
IT WILL BE A COMPLEX POP FORECAST THIS MORNING GIVEN VARIOUS
OPERATIONAL MODELS AND CONVECTION ALLOW MODELS SOLUTIONS. HAVE
USED A BLEND OF THE NCEP HRRR AND THE ESRL HRRR TO TRY TO PINPOINT
POPS AND TIMING OF PCPN TODAY.
AN EMBEDDED S/WV TO OUR SOUTHWEST THIS MORNING IS FORECAST TO
EJECT NORTHEAST ACROSS OUR REGION THROUGH EARLY AFTERNOON. IT WILL
ALSO BE ACCOMPANIED BY A COLD FRONT. MOSAIC RADAR CONTINUES TO
DEPICT AN AREA OF SHOWERS/EMBEDDED THUNDER APPROACHING THE
CINCINNATI TRI-STATE REGION. THIS PCPN SHOULD PUSH INTO THE
SOUTHWESTERN AND WESTERN ZONES EARLY THIS MORNING AND AS SUCH HAVE
GONE WITH LIKELY POPS IN THESE LOCATIONS. FOR THE REMAINDER OF THE
REGION...IT GETS A LITTLE TRICKY AS CAMS TRY TO WEAKEN PCPN SHIELD
AND THEN FOCUS MORE SCATTERED SHOWERS/EMBEDDED THUNDERSTORMS ALONG
AND AHEAD OF THE COLD FRONT. HAVE GONE WITH HIGH CHANCE POPS IN
THE EAST TO ACCOUNT FOR THIS. THERE IS A MARGINAL RISK OF SEVERE
STORMS TODAY OVER OUR EASTERN TWO THIRDS CWFA. INSTABILITY SEEMS
TO BE LACKING OVERALL DESPITE SOME FAVORABLE WINDS ALOFT. BELIEVE
WE WILL PROBABLY SEE SOME GUSTY WINDS WITH SHOWERS/THUNDERSTORMS...
BUT THEY SHOULD STAY BELOW SEVERE LIMITS. WE WILL ALSO SEE SOME
SYNOPTIC SCALE GUSTS IN THE 25 TO 30 KNOT RANGE AS CAA DEVELOPS IN
THE WAKE OF THE FRONT. HIGHS TODAY WILL BE TOUGH GIVEN EARLY
WARMTH AND THEN A GRADUAL DROP TO TEMPERATURES FROM WEST TO EAST
IN THE CAA PATTERN. HAVE RANGED HIGHS FROM NEAR 60 WEST TO THE
UPPER 60S EAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
MODELS INDICATE THAT THERE COULD BE A FEW LIGHT SHOWERS LINGERING
BEHIND THE FRONT THIS EVENING. THEREAFTER...SKIES SHOULD GRADUALLY
BECOME MOSTLY CLEAR AS DRIER AIR ADVECTS INTO THE AREA.
FOR TUESDAY INTO WEDNESDAY...HAVE TAKEN A BLEND OF THE ECMWF AND
THE NAM-WRF. THE OPERATIONAL GFS SEEMS PECULIAR WITH ITS BIG QPF
BULLSEYES FOR TUESDAY NIGHT INTO WEDNESDAY GIVEN THE MOISTURE
STARVED REGIME. WE SHOULD SEE PARTLY TO MOSTLY SUNNY SKIES FOR
MUCH OF THE DAY. BIGGEST WEATHER MAKER WILL BE THE WINDS. PRESSURE
GRADIENT BETWEEN LOW PRESSURE TO OUR NORTH AND HIGH PRESSURE TO
OUR SOUTH...COMBINED WITH DEEP ADIABATIC MIXING...WILL RESULT IN
BREEZY TO WINDY CONDITIONS FROM LATE MORNING INTO THE EARLY
EVENING. THE GFS IS THE ONLY MODEL THAT WOULD INDICATE THE NEED
FOR A WIND ADVISORY ACRS OUR NRN ZONES FOR TUESDAY. SINCE THIS IS
THE OUTLIER ATTM...HAVE GONE WITH THE NAM WHICH KEEPS SUSTAINED
WINDS IN THE 15 TO 25 KNOT RANGE AND GUSTS GENERALLY IN THE 25 TO
35 RANGE. WE NEED SUSTAINED 27 KNOTS AND GUSTS OF 40 KNOTS FOR A
WIND ADVISORY. BY LATE IN THE DAY...MODELS INDICATE THAT A TONGUE
OF MAINLY MID LEVEL MOISTURE WILL PUSH INTO THE SRN ZONES. GIVEN
DRY LOWER LEVELS...HAVE OPTED TO JUST MENTIONED A SLIGHT CHANCE
FOR LIGHT SHOWERS HERE.
FOR TUESDAY NIGHT INTO WEDNESDAY...A WEAK COLD FRONT WILL PUSH
SOUTHEAST THROUGH THE FORECAST AREA. A CONVERGENT CONFIGURATION
IN THE LOW LEVELS MAY BRING A SLIGHT CHC/CHC FOR SHOWERS ACRS THE
SRN ZONES TUESDAY NIGHT. IT NOW LOOKS LIKE WEDNESDAY SHOULD BE DRY
AS WE WILL BE BETWEEN SYSTEMS. IT WILL CONTINUE TO COOL THROUGH
THE PERIOD.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A VERY COOL AND DRY PERIOD EXPECTED FOR THU/FRI BEFORE LARGE SCALE
UPR LOW FINALLY LIFTS JUST ENOUGH NORTH TO ALLOW FOR A MORE VIGOROUS
SOUTHERN STREAM S/WV TO AGAIN BRING SHOWERS TO THE SOUTHERN FCST
AREA.
CONTINUED THE UNSEASONABLY COOL TREND WITH THE UPR LOW DOMINATING
THE NORTHERN AREA AND GENERAL NW FLOW THROUGH MUCH OF THE PERIOD.
POTENTIAL FOR MID/UPR 30S FOR LOW TEMPS WED NIGHT AND LOW/MID 30S
THURS NIGHT.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
SHOWERS ARE MOVING OUT OF THE AREA RIGHT NOW...LEAVING DRY
CONDITIONS FOR THE REST OF THE OVERNIGHT HOURS. CEILINGS SHOULD
GENERALLY REMAIN IN THE MVFR CATEGORY THROUGH MORNING...WITH A FEW
BREAKS TO VFR POSSIBLE.
ANOTHER ROUND OF SHOWERS IS EXPECTED TO MOVE INTO THE REGION
BETWEEN 11Z AND 14Z...WITH A POSSIBILITY FOR REDUCED VISIBILITIES.
MVFR CEILINGS ARE EXPECTED TO BECOME THICKER THROUGH THE MORNING
WITH RAIN IN THE VICINITY. AS THIS IS OCCURRING...WINDS WILL SHIFT
TO THE SSW AND INCREASE IN STRENGTH. WIND GUSTS AS HIGH AS 30
KNOTS WILL BE POSSIBLE.
ADDITIONAL SHOWERS MAY DEVELOP DURING THE AFTERNOON AND EARLY
EVENING...BUT THESE WILL BE DISORGANIZED AND BRIEF...AND ARE
COVERED WITH A VCSH IN THE TAFS. WINDS WILL EVENTUALLY SHIFT TO
THE WSW AND WEAKEN SLIGHTLY BY EVENING...AS CLOUDS BREAK TO VFR
AROUND THE SAME TIME.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...JDR
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS MEDFORD OR
847 PM PDT TUE APR 21 2015
.DISCUSSION...THUNDERSTORMS ARE RUMBLING ACROSS SOUTHEAST SISKIYOU
COUNTY FROM MOUNT SHASTA EASTWARD. RADAR AND SATELLITE IMAGERY
SHOW THREE MORE CELLS ONE OF WHICH LOOKS POTENT ARE APPROACHING
THIS AREA FROM SHASTA COUNTY. SOUTHERN SISKIYOU COUNTY AND
NORTHERN KLAMATH COUNTY WERE THE AREAS THAT MODELS PAINTED THE
MOST INSTABILITY SO CONFIDENCE IS HIGH AS WE MOVE FORWARD INTO THE
REST OF THE NIGHT FORECAST TIMEFRAME. THE SHORT TERM HRRR TAKES
THIS UNSTABLE AREA EAST AND BY MIDNIGHT THE AREA OF CONCERNS SHIFT
TO LAKE COUNTY..ESPECIALLY THE LINE ROUGHLY FOLLOWING HIGHWAY 395
FROM LAKE-HARNEY COUNTY LINE SOUTH INTO MODOC COUNTY...WITH THE
WARNERS SEEING MOST OF THE ACTIVITIES AFTER MIDNIGHT. WE HAVE
UPDATED THE POPS AND WEATHER GRIDS TO INDICATE THIS TREND AND
GRIDS HAVE BEEN POSTED. SO FAR THESE STORMS HAVE PRODUCED RAINFALL
BETWEEN 0.15-0.25 INCH WITH ONE AREA NEAR MCCLOUD RECEIVING ALMOST
HALF AN INCH OF RAIN. /FB
&&
.AVIATION...FOR THE 22/00Z TAF CYCLE...SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS WILL PERSIST THIS EVENING FROM ABOUT THE
SHASTA REGION EASTWARD TO THE WARNERS...THEN NORTHWARD INTO LAKE AND
EASTERN KLAMATH COUNTIES. MOST OF THE ACTIVITY WILL BE SOUTH AND
EAST OF KLMT. OVERALL, CIGS IN THESE AREAS WILL BE VFR, THOUGH
TERRAIN MAY BE PARTLY OBSCURED WITH TEMPORARY MVFR IN HEAVIER
SHOWERS/THUNDERSTORMS.
ALONG THE COAST NORTH OF PORT ORFORD, EXPECT MVFR CIGS WITH AN
ISOLATED SHOWER THROUGH THIS EVENING. MVFR CIGS WILL GRADUALLY LIFT
TO VFR LATER WEDNESDAY MORNING OR AFTERNOON. OFFSHORE FLOW WILL
RESULT IN VFR ALONG THE SOUTH COAST THROUGH WEDNESDAY.
THE REST OF THE WEST SIDE TO THE CASCADES WILL BE MOSTLY VFR THROUGH
LATE THIS EVENING WITH JUST ISOLATED SHOWERS...THOUGH AREAS OF MVFR
AND PARTIAL TERRAIN OBSCURATIONS WILL DEVELOP AND LAST THROUGH ABOUT
MID-LATE MORNING WEDNESDAY. SPILDE
&&
.MARINE...UPDATED 800 PM PDT TUESDAY APR 21, 2015...HIGH PRESSURE
WILL BUILD INTO THE AREA TONIGHT BUT THIS WILL RESULT IN GUSTY NORTH
WINDS AND STEEP TO VERY STEEP SEAS. GALES AND WARNING LEVEL SEAS ARE
EXPECTED AT TIMES SOUTH OF CAPE BLANCO TONIGHT THROUGH WEDNESDAY
NIGHT. THURSDAY THROUGH THE WEEKEND...A SERIES OF FRONTAL SYSTEMS IS
LIKELY TO MOVE THROUGH WITH BUILDING SWELL. NORTHWEST WINDS
WEDNESDAY NIGHT THROUGH FRIDAY ARE EXPECTED TO BECOME SOUTHWESTERLY
THIS WEEKEND. FB
&&
.PREV DISCUSSION... /ISSUED 516 PM PDT TUE APR 21 2015/
SHORT TERM...VISIBLE SATELLITE SHOWS THE ATMOSPHERE HAS
DESTABILIZED AS EXPECTED WITH NUMEROUS CUMULUS BUILDUPS OVER THE
HIGHER TERRAIN AND EAST SIDE. RADAR IS ALREADY SHOWING RETURNS IN
EASTERN SISKIYOU, NORTHERN KLAMATH, AND CENTRAL LAKE COUNTIES.
THERE HAS EVEN BEEN A STRIKE OR TWO RECORDED IN EASTERN SISKIYOU
COUNTY JUST WEST OF TENANT. AND NUMEROUS STRIKES RECORDED JUST
SOUTH OF THE CWA IN LASSEN COUNTY. HI-RES, NEAR TERM MODELS LIKE
THE HRRR (HIGH RESOLUTION RAPID REFRESH) SHOW MOST OF THE ACTION
OVER MODOC, LAKE, AND FAR EASTERN KLAMATH COUNTIES LATER THIS
AFTERNOON. STEERING WINDS ARE FAIRLY LIGHT SO THESE STORMS WILL
LIKELY BE SLOW MOVERS RESULTING IN THE POTENTIAL FOR SOME HEAVIER
DOWNPOURS UNDER THE CORE OF THESE STORMS. ALSO EXPECT SOME GUSTY
OUTFLOW WINDS WITH THE STRONGER STORMS ALONG WITH THE POTENTIAL
FOR SMALL HAIL. MODELS CONTINUE TO SHOW THE ATMOSPHERE STABILIZING
WITH THE LOSS OF DIURNAL HEATING SO CONVECTION SHOULD DIMINISH BY
TONIGHT. THE ATMOSPHERE WEST OF THE CASCADES IS MORE STABLE WITH
WEAKER LAPSE RATES SO NOT EXPECTING ANY THUNDERSTORMS FOR THAT
AREA.
ASIDE FROM THE RAIN EXPECTED WITH THE CONVECTION PREVIOUSLY MENTIONED,
MOST AREAS WILL REMAIN DRY WITH THE PASSAGE OF THE COLD FRONT.
WINDS WILL BE QUITE BREEZY THROUGH THE AFTERNOON IN RESPONSE TO
THIS COLD FRONT MOVING THROUGH THE AREA. THE UPPER LEVEL TROUGH
MOVES THROUGH OVERNIGHT INTO TOMORROW AND DRIER, MORE STABLE AIR
MOVES IN BEHIND IT FOR WEDNESDAY. WEAK RIDGING STARTS TO BUILD
OVER THE AREA WEDNESDAY NIGHT, BUT THIS IS SHORT LIVED AS A WEAK
TROUGH APPROACHES THE AREA THURSDAY MORNING. THERE IS A CHANCE FOR
SOME SHOWERS THURSDAY AFTERNOON, BUT THIS LOOKS MOSTLY CONFINED
FROM THE UMPQUA DIVIDE AND NORTH.
AN UPPER LOW MOVES IN OVER BRITISH COLUMBIA THURSDAY EVENING AND
SHORTWAVES ROTATING AROUND IT CONTINUE THE CHANCE FOR PRECIPITATION
FOR MOST OF THE AREA THROUGH SATURDAY MORNING. MND
LONG TERM...SATURDAY THROUGH TUESDAY...THE OPERATIONAL EC AND
GFS ARE IN SIMILAR AGREEMENT WITH THE OVERALL PATTERN FRIDAY INTO
NEXT WEEKEND. HOWEVER THERE IS DISAGREEMENT WITH THE PLACEMENT AND
STRENGTH OF THE UPPER LOW FRIDAY. THE EC IS STRONGER AND FURTHER
SOUTH WITH THE UPPER LOW AND WETTER. HAVE KEPT IN A CHANCE OF
SHOWERS FOR MOST OF THE FORECAST AREA...THOUGH RAIN AND MOUNTAIN
SNOW AMOUNTS SHOULD BE LIGHT. THE TROUGH AXIS SHIFTS EAST FRIDAY
NIGHT AND RIDGING WILL ATTEMPT TO MOVE IN FROM THE SOUTHWEST. THE
GFS SHOWS MORE OF A DIRTY RIDGE SCENARIO WITH WARM FRONTAL
PRECIPITATION MOVING INTO THE AREA. THE EC HAS A MORE PRONOUNCED
RIDGE AND THUS SHOWS A DRY AND MILDER SOLUTION. SUSPECT THE WARM
FRONTAL PRECIPITATION IS OVERDONE, BUT DID NOT WANT TO DISCOUNT IT
COMPLETELY, SO WITH WITH A BLEND BETWEEN THE EC AND GFS WITH A
SLIGHTLY DRIER BIAS.
A DIRTY RIDGE REMAIN OVER THE AREA SUNDAY WITH THE BEST CHANCE FOR
PRECIPITATION OVER THE NORTHERN PART OF THE CWA. ESPECIALLY WEST OF
THE CASCADES AND NORTH OF THE UMPQUA DIVIDE.
SIGNIFICANT UPPER TROUGHING THAT`S BEEN HANGING OVER THE NORTHEAST
PACIFIC FINALLY REACHES THE FORECAST AREA WITH SIGNIFICANT RAIN
POTENTIALLY MONDAY INTO TUESDAY. THAT SAID...THERE IS SOME
UNCERTAINTY AS TO WHEN THIS TROUGHING REACHES THE AREA. ENSEMBLE
MEMBERS ARE OUT OF PHASE...BUT NOT AS MUCH AS YESTERDAY WITH THE
TROUGH AXIS STARTING TO DROP SOUTH. IN CONTRAST, THE OPERATIONAL EC
SHOWS MORE OF A SPLIT FLOW PATTERN NEAR 150 W AND MORE RIDGING IN
OUR AREA, THUS DELAYING ANY SIGNIFICANT PRECIPITATION.
IN SHORT...CONFIDENCE IS LOW TO MODERATE IN THE EXTENDED PERIOD AND
DID NOT MAKE ANY SIGNIFICANT CHANGES. -PETRUCELLI
AVIATION...FOR THE 22/00Z TAF CYCLE...SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS WILL PERSIST THIS EVENING FROM ABOUT THE
SHASTA REGION EASTWARD TO THE WARNERS...THEN NORTHWARD INTO LAKE AND
EASTERN KLAMATH COUNTIES. MOST OF THE ACTIVITY WILL BE SOUTH AND
EAST OF KLMT. OVERALL, CIGS IN THESE AREAS WILL BE VFR, THOUGH
TERRAIN MAY BE PARTLY OBSCURED WITH TEMPORARY MVFR IN HEAVIER
SHOWERS/THUNDERSTORMS.
ALONG THE COAST NORTH OF PORT ORFORD, EXPECT MVFR CIGS WITH AN
ISOLATED SHOWER THROUGH THIS EVENING. MVFR CIGS WILL GRADUALLY LIFT
TO VFR LATER WEDNESDAY MORNING OR AFTERNOON. OFFSHORE FLOW WILL
RESULT IN VFR ALONG THE SOUTH COAST THROUGH WEDNESDAY.
THE REST OF THE WEST SIDE TO THE CASCADES WILL BE MOSTLY VFR THROUGH
LATE THIS EVENING WITH JUST ISOLATED SHOWERS...THOUGH AREAS OF MVFR
AND PARTIAL TERRAIN OBSCURATIONS WILL DEVELOP AND LAST THROUGH ABOUT
MID-LATE MORNING WEDNESDAY. SPILDE
MARINE...UPDATED 300 PM PDT TUESDAY APR 21, 2015...HIGH PRESSURE
WILL BUILD INTO THE AREA TONIGHT BUT THIS WILL RESULT IN GUSTY NORTH
WINDS AND STEEP TO VERY STEEP SEAS. GALES AND WARNING LEVEL SEAS ARE
EXPECTED AT TIMES SOUTH OF CAPE BLANCO TONIGHT THROUGH WEDNESDAY
NIGHT. THURSDAY THROUGH THE WEEKEND...A SERIES OF FRONTAL SYSTEMS IS
LIKELY TO MOVE THROUGH WITH BUILDING SWELL. NORTHWEST WINDS
WEDNESDAY NIGHT THROUGH FRIDAY ARE EXPECTED TO BECOME SOUTHWESTERLY
THIS WEEKEND. SPILDE
FIRE WEATHER...UPDATED 3 PM PDT TUESDAY, APRIL 21ST, 2015... THE
ATMOSPHERE IS ALREADY STARTING TO BECOME UNSTABLE AHEAD OF A
RATHER SHARP, BUT NOT STRONG, INCOMING TROUGH OF LOW PRESSURE. A
FEW ISOLATED STORMS HAVE DEVELOPED IN NORTHERN CAL AND NORTHERN
KLAMATH COUNTY NORTHEAST OF CHEMULT. THE LATEST HRRR REFLECTIVITY
PRODUCT SHOWS MOST OF THE ACTIVITY DEVELOPING IN NORTHERN CAL,
THEN MIGRATING NORTH INTO PARTS OF LAKE AND KLAMATH COUNTIES LATE
THIS AFTERNOON THROUGH THIS EVENING. UNLIKE THE HIGH IMPACT
LIGHTNING EVENTS THAT SOMETIMES AFFECT OUR REGION MAINLY IN THE
SUMMER, FORCING WITH THE INCOMING SYSTEM IS WEAK IN THAT THERE IS
NO CLEAR COLD POOL MOVING THROUGH. INSTEAD, A WEAK SURFACE FRONT
IS EXPECTED TO DEVELOP ALONG AND NEAR THE CASCADES THIS AFTERNOON.
THIS SHOULD GIVE RISE TO BUILD-UPS ALONG AND NEAR THE TRINITY ALPS
AND CASCADE CREST THIS AFTERNOON, SHIFTING EASTWARD TO THE LEE OF
THE CASCADES TOWARDS THE EVENING. CONDITIONS ARE MOST FAVORABLE
FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN THESE LEE AND
EAST SIDE AREAS. MOST GUIDANCE FOCUSES ACTIVITY THIS EVENING IN
THE WARNER MOUNTAINS OF LAKE COUNTY AND ANOTHER IN NORTHERN LAKE
COUNTY THIS EVENING. WHILE FIRE DANGER DID REACH HIGH IN PORTIONS
OF THE MODOC ON MONDAY, FORECAST FIRE DANGER FOR TODAY IS
MODERATE. ADDITIONALLY, DEPARTURE FROM AVERAGE GREENNESS IS SPOTTY
IN TERMS OF DEFICITS, SO SUSPECT THERE`S SOME GREEN-UP COMPONENT
TO THE LIVE FUELS NOW. MODELS INDICATE THAT ANY STORMS THAT DO GET
GOING WILL PRODUCE GUSTY OUTFLOW WINDS MAINLY IN THE 20 TO 30 MPH
RANGE, BUT ALSO SOME MEASURABLE RAINFALL. THUS, DESPITE UNUSUALLY
DRY CONDITIONS DUE TO THE ONGOING DROUGHT, WE HAVE DECIDED THAT
THIS EVENT DOES NOT WARRANT ANY WARNINGS. INSTEAD, A HEADS-UP TYPE
OF HEADLINE WILL BE MAINTAINED IN THE FORECAST. BTL/PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT THURSDAY FOR
PZZ350-356-370-376.
HAZARDOUS SEAS WARNING UNTIL 5 AM PDT THURSDAY FOR PZZ356-376.
GALE WARNING UNTIL 5 AM PDT THURSDAY FOR PZZ356-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT THURSDAY
FOR PZZ350-356-370-376.
$$
FJB/FJB/MAS
AREA FORECAST DISCUSSION...UPDATED
NWS MEDFORD OR
516 PM PDT TUE APR 21 2015
UPDATED AVIATION SECTION
.SHORT TERM...VISIBLE SATELLITE SHOWS THE ATMOSPHERE HAS
DESTABILIZED AS EXPECTED WITH NUMEROUS CUMULUS BUILDUPS OVER THE
HIGHER TERRAIN AND EAST SIDE. RADAR IS ALREADY SHOWING RETURNS IN
EASTERN SISKIYOU, NORTHERN KLAMATH, AND CENTRAL LAKE COUNTIES.
THERE HAS EVEN BEEN A STRIKE OR TWO RECORDED IN EASTERN SISKIYOU
COUNTY JUST WEST OF TENANT. AND NUMEROUS STRIKES RECORDED JUST
SOUTH OF THE CWA IN LASSEN COUNTY. HI-RES, NEAR TERM MODELS LIKE
THE HRRR (HIGH RESOLUTION RAPID REFRESH) SHOW MOST OF THE ACTION
OVER MODOC, LAKE, AND FAR EASTERN KLAMATH COUNTIES LATER THIS
AFTERNOON. STEERING WINDS ARE FAIRLY LIGHT SO THESE STORMS WILL
LIKELY BE SLOW MOVERS RESULTING IN THE POTENTIAL FOR SOME HEAVIER
DOWNPOURS UNDER THE CORE OF THESE STORMS. ALSO EXPECT SOME GUSTY
OUTFLOW WINDS WITH THE STRONGER STORMS ALONG WITH THE POTENTIAL
FOR SMALL HAIL. MODELS CONTINUE TO SHOW THE ATMOSPHERE STABILIZING
WITH THE LOSS OF DIURNAL HEATING SO CONVECTION SHOULD DIMINISH BY
TONIGHT. THE ATMOSPHERE WEST OF THE CASCADES IS MORE STABLE WITH
WEAKER LAPSE RATES SO NOT EXPECTING ANY THUNDERSTORMS FOR THAT
AREA.
ASIDE FROM THE RAIN EXPECTED WITH THE CONVECTION PREVIOUSLY MENTIONED,
MOST AREAS WILL REMAIN DRY WITH THE PASSAGE OF THE COLD FRONT.
WINDS WILL BE QUITE BREEZY THROUGH THE AFTERNOON IN RESPONSE TO
THIS COLD FRONT MOVING THROUGH THE AREA. THE UPPER LEVEL TROUGH
MOVES THROUGH OVERNIGHT INTO TOMORROW AND DRIER, MORE STABLE AIR
MOVES IN BEHIND IT FOR WEDNESDAY. WEAK RIDGING STARTS TO BUILD
OVER THE AREA WEDNESDAY NIGHT, BUT THIS IS SHORT LIVED AS A WEAK
TROUGH APPROACHES THE AREA THURSDAY MORNING. THERE IS A CHANCE FOR
SOME SHOWERS THURSDAY AFTERNOON, BUT THIS LOOKS MOSTLY CONFINED
FROM THE UMPQUA DIVIDE AND NORTH.
AN UPPER LOW MOVES IN OVER BRITISH COLUMBIA THURSDAY EVENING AND
SHORTWAVES ROTATING AROUND IT CONTINUE THE CHANCE FOR PRECIPITATION
FOR MOST OF THE AREA THROUGH SATURDAY MORNING. MND
.LONG TERM...SATURDAY THROUGH TUESDAY...THE OPERATIONAL EC AND
GFS ARE IN SIMILAR AGREEMENT WITH THE OVERALL PATTERN FRIDAY INTO
NEXT WEEKEND. HOWEVER THERE IS DISAGREEMENT WITH THE PLACEMENT AND
STRENGTH OF THE UPPER LOW FRIDAY. THE EC IS STRONGER AND FURTHER
SOUTH WITH THE UPPER LOW AND WETTER. HAVE KEPT IN A CHANCE OF
SHOWERS FOR MOST OF THE FORECAST AREA...THOUGH RAIN AND MOUNTAIN
SNOW AMOUNTS SHOULD BE LIGHT. THE TROUGH AXIS SHIFTS EAST FRIDAY
NIGHT AND RIDGING WILL ATTEMPT TO MOVE IN FROM THE SOUTHWEST. THE
GFS SHOWS MORE OF A DIRTY RIDGE SCENARIO WITH WARM FRONTAL
PRECIPITATION MOVING INTO THE AREA. THE EC HAS A MORE PRONOUNCED
RIDGE AND THUS SHOWS A DRY AND MILDER SOLUTION. SUSPECT THE WARM
FRONTAL PRECIPITATION IS OVERDONE, BUT DID NOT WANT TO DISCOUNT IT
COMPLETELY, SO WITH WITH A BLEND BETWEEN THE EC AND GFS WITH A
SLIGHTLY DRIER BIAS.
A DIRTY RIDGE REMAIN OVER THE AREA SUNDAY WITH THE BEST CHANCE FOR
PRECIPITATION OVER THE NORTHERN PART OF THE CWA. ESPECIALLY WEST OF
THE CASCADES AND NORTH OF THE UMPQUA DIVIDE.
SIGNIFICANT UPPER TROUGHING THAT`S BEEN HANGING OVER THE NORTHEAST
PACIFIC FINALLY REACHES THE FORECAST AREA WITH SIGNIFICANT RAIN
POTENTIALLY MONDAY INTO TUESDAY. THAT SAID...THERE IS SOME
UNCERTAINTY AS TO WHEN THIS TROUGHING REACHES THE AREA. ENSEMBLE
MEMBERS ARE OUT OF PHASE...BUT NOT AS MUCH AS YESTERDAY WITH THE
TROUGH AXIS STARTING TO DROP SOUTH. IN CONTRAST, THE OPERATIONAL EC
SHOWS MORE OF A SPLIT FLOW PATTERN NEAR 150 W AND MORE RIDGING IN
OUR AREA, THUS DELAYING ANY SIGNIFICANT PRECIPITATION.
IN SHORT...CONFIDENCE IS LOW TO MODERATE IN THE EXTENDED PERIOD AND
DID NOT MAKE ANY SIGNIFICANT CHANGES. -PETRUCELLI
&&
.AVIATION...FOR THE 22/00Z TAF CYCLE...SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS WILL PERSIST THIS EVENING FROM ABOUT THE
SHASTA REGION EASTWARD TO THE WARNERS...THEN NORTHWARD INTO LAKE AND
EASTERN KLAMATH COUNTIES. MOST OF THE ACTIVITY WILL BE SOUTH AND
EAST OF KLMT. OVERALL, CIGS IN THESE AREAS WILL BE VFR, THOUGH
TERRAIN MAY BE PARTLY OBSCURED WITH TEMPORARY MVFR IN HEAVIER
SHOWERS/THUNDERSTORMS.
ALONG THE COAST NORTH OF PORT ORFORD, EXPECT MVFR CIGS WITH AN
ISOLATED SHOWER THROUGH THIS EVENING. MVFR CIGS WILL GRADUALLY LIFT
TO VFR LATER WEDNESDAY MORNING OR AFTERNOON. OFFSHORE FLOW WILL
RESULT IN VFR ALONG THE SOUTH COAST THROUGH WEDNESDAY.
THE REST OF THE WEST SIDE TO THE CASCADES WILL BE MOSTLY VFR THROUGH
LATE THIS EVENING WITH JUST ISOLATED SHOWERS...THOUGH AREAS OF MVFR
AND PARTIAL TERRAIN OBSCURATIONS WILL DEVELOP AND LAST THROUGH ABOUT
MID-LATE MORNING WEDNESDAY. SPILDE
&&
.MARINE...UPDATED 300 PM PDT TUESDAY APR 21, 2015...HIGH PRESSURE
WILL BUILD INTO THE AREA TONIGHT BUT THIS WILL RESULT IN GUSTY NORTH
WINDS AND STEEP TO VERY STEEP SEAS. GALES AND WARNING LEVEL SEAS ARE
EXPECTED AT TIMES SOUTH OF CAPE BLANCO TONIGHT THROUGH WEDNESDAY
NIGHT. THURSDAY THROUGH THE WEEKEND...A SERIES OF FRONTAL SYSTEMS IS
LIKELY TO MOVE THROUGH WITH BUILDING SWELL. NORTHWEST WINDS
WEDNESDAY NIGHT THROUGH FRIDAY ARE EXPECTED TO BECOME SOUTHWESTERLY
THIS WEEKEND. SPILDE
&&
.FIRE WEATHER...UPDATED 3 PM PDT TUESDAY, APRIL 21ST, 2015... THE
ATMOSPHERE IS ALREADY STARTING TO BECOME UNSTABLE AHEAD OF A
RATHER SHARP, BUT NOT STRONG, INCOMING TROUGH OF LOW PRESSURE. A
FEW ISOLATED STORMS HAVE DEVELOPED IN NORTHERN CAL AND NORTHERN
KLAMATH COUNTY NORTHEAST OF CHEMULT. THE LATEST HRRR REFLECTIVITY
PRODUCT SHOWS MOST OF THE ACTIVITY DEVELOPING IN NORTHERN CAL,
THEN MIGRATING NORTH INTO PARTS OF LAKE AND KLAMATH COUNTIES LATE
THIS AFTERNOON THROUGH THIS EVENING. UNLIKE THE HIGH IMPACT
LIGHTNING EVENTS THAT SOMETIMES AFFECT OUR REGION MAINLY IN THE
SUMMER, FORCING WITH THE INCOMING SYSTEM IS WEAK IN THAT THERE IS
NO CLEAR COLD POOL MOVING THROUGH. INSTEAD, A WEAK SURFACE FRONT
IS EXPECTED TO DEVELOP ALONG AND NEAR THE CASCADES THIS AFTERNOON.
THIS SHOULD GIVE RISE TO BUILD-UPS ALONG AND NEAR THE TRINITY ALPS
AND CASCADE CREST THIS AFTERNOON, SHIFTING EASTWARD TO THE LEE OF
THE CASCADES TOWARDS THE EVENING. CONDITIONS ARE MOST FAVORABLE
FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN THESE LEE AND
EAST SIDE AREAS. MOST GUIDANCE FOCUSES ACTIVITY THIS EVENING IN
THE WARNER MOUNTAINS OF LAKE COUNTY AND ANOTHER IN NORTHERN LAKE
COUNTY THIS EVENING. WHILE FIRE DANGER DID REACH HIGH IN PORTIONS
OF THE MODOC ON MONDAY, FORECAST FIRE DANGER FOR TODAY IS
MODERATE. ADDITIONALLY, DEPARTURE FROM AVERAGE GREENNESS IS SPOTTY
IN TERMS OF DEFICITS, SO SUSPECT THERE`S SOME GREEN-UP COMPONENT
TO THE LIVE FUELS NOW. MODELS INDICATE THAT ANY STORMS THAT DO GET
GOING WILL PRODUCE GUSTY OUTFLOW WINDS MAINLY IN THE 20 TO 30 MPH
RANGE, BUT ALSO SOME MEASURABLE RAINFALL. THUS, DESPITE UNUSUALLY
DRY CONDITIONS DUE TO THE ONGOING DROUGHT, WE HAVE DECIDED THAT
THIS EVENT DOES NOT WARRANT ANY WARNINGS. INSTEAD, A HEADS-UP TYPE
OF HEADLINE WILL BE MAINTAINED IN THE FORECAST. BTL/PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT
THURSDAY FOR PZZ350-356-370-376.
HAZARDOUS SEAS WARNING UNTIL 5 AM PDT THURSDAY FOR PZZ356-376.
GALE WARNING UNTIL 5 AM PDT THURSDAY FOR PZZ356-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT THURSDAY
FOR PZZ350-356-370-376.
$$
MAS/MND/MAP
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
102 PM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY BRINGING ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. DRY HIGH PRESSURE BUILDS IN FOR TUESDAY
AND WEDNESDAY. ANOTHER COLD FRONT WILL PUSH IN FROM THE NORTHWEST ON
THURSDAY...POSSIBLY BRINGING SHOWERS BACK TO THE AREA. A STRONGER
STORM SYSTEM WILL MOVE IN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM...GUSTY TSTMS...WHAT APPEAR TO BE DRIVEN BY MCV...
SHOULD TRANSLATE QUICKLY EAST OF THE CWFA BY 15 UTC. IT SEEMS
LIKE THERE WILL BE SVRL HOURS OF ECHO FREE CONDITIONS ACRS THE
CWFA. WITHIN THE BROAD PRE-COLD FRONTAL ENVIRONMENT...PROGRESSIVE
DESTABILIZATION IS EXPECTED THROUGH THE AFTERNOON. THE NEWLY POSTED
12 UTC NAM AND CONVECTION ALLOWING MODELS EXPECTEDLY RESPOND
FAVORABLY WITHIN LLVL FRONTAL CONVERGENCE ZONE...PROGGING WIDESPREAD
DEEP CONVECTION. FAVORABLE SHEAR PROFILES LEND SUPPORT TO THE
PROBABILITY OF DISCRETE STORMS IN THE PIEDMONT LATER TODAY.
AS OF 645 AM...WELL THE NEAR TERM MODELS AND CAMS ARE NOT DOING VERY
WELL WITH THE CONVECTION ENTERING OUR WESTERN ZONES EARLY THIS
MORNING. HAVE BUMPED UP POP IN THE WEST. STILL EXPECT WEAKENING AS
THE REMNANT PRECIP CROSSES THE AREA THRU THE MORNING HOURS. CANNOT
RULE OUT A STRONG OR MARGINALLY SEVERE STORM EARLY ON...BUT
OTHERWISE JUST SOME CG LIGHTNING AND DOWNPOURS WITH THAT ACTIVITY.
THE REST OF THE FCST WAS LEFT UNCHANGED.
AS OF 330 AM...IN THE IMMEDIATE NEAR TERM...THE RADAR HAS GONE INTO
CLEAR AIR MODE...AS A LEAD SHORTWAVE HAS EXITED TO THE NE WITHIN
DEEP LAYER SWLY FLOW. A QUASI-LINEAR MCS IS CURRENTLY CROSSING
CENTRAL TN AND NRN AL. GUIDANCE SEEMS TO BE UNDERESTIMATING THE
STRENGTH/PERSISTENCE OF THIS SYSTEM. THE LATEST RAP ANALYSIS SHOWS
500-1000 J/KG OF MUCAPE WITH 35-45 KTS OF EFFECTIVE SHEAR DOWNSTREAM
OF THIS CLUSTER. THIS RESULTS IN A /MCS MAINTENANCE/ PROB AT 70-80
PCT. SO IT IS NOW EXPECTED THAT THESE STORMS (WHILE STILL ON A
GRADUAL WEAKENING TREND) WILL LIKELY STILL SURVIVE INTO THE NC MTNS
EARLY THIS MORNING. GIVEN THE CURRENT STATE...CANNOT RULE OUT A
STRONG OR SEVERE STORM OR TWO...ESP IN GRAHAM/SWAIN...WHEN THE LINE
GETS INTO THE CWFA. FROM THERE...IT/S DIFFICULT TO SAY HOW MUCH
PRECIP WILL LINGER ACRS THE CWFA THIS MORNING. I HAVE BUMPED UP POP
IN THE WRN MTNS...BUT KEEP JUST A SHOTGUN CHC POP FOR THE REST OF
THE AREA THIS MORNING.
LATER TODAY...GUIDANCE IN GOOD AGREEMENT ON ANOTHER SPOKE OF
VORTICITY ROTATING AROUND THE BROAD CYCLONICALLY CURVED
FLOW...CROSSING THE CWFA FROM THE SOUTHWEST DURING THE PEAK-HEATING
AFTN HOURS. MEANWHILE...A COLD FRONT WILL PUSH INTO THE AREA THIS
AFTN. THE FRONT LOOKS TO ONLY HAVE MODEST LLVL CONVERGENCE.
HOWEVER...GIVEN THE STEEP MID LVL LAPSE RATES AND LINGERING BL
MOISTURE (DEWPTS IN THE MID 60S ACRS THE PIEDMONT). FAIRLY CONFIDENT
IN AT LEAST 40-50 PCT COVERAGE OF CONVECTION...MAYBE HIGHER TO THE
EAST. THE FCST SNDGS SHOW LONG BUT SLIGHTLY CURVED HODOGRAPHS WITH
1500-2500 J/KG OF UNCAPPED SBCAPE. SO EXPECT SOMEWHAT DISCRETE
STORMS INITIALLY...WITH POTENTIAL FOR SUPERCELLS. DEFINITELY WILL
BE A DAMAGING WIND AND HAIL THREAT...WITH AN ISOLD TORNADO THREAT
ACRS THE PIEDMONT THIS AFTN. THE HIGH RES MODELS DO NOT SEEM THAT
IMPRESSED WITH COVERAGE OR INTENSITY. I/M NOT SURE WHAT IS LIMITING
THEIR CONVECTION EXPECT FOR PERHAPS LACK OF DEEPER MOISTURE. THE NEW
DAY 1 CONVECTIVE OUTLOOK STILL HAS ALL AREAS EAST OF THE MTNS IN THE
SLGT RISK...AND A MARGINAL RISK FOR THE MTNS. OTHERWISE...IT WILL BE
BREEZY TODAY UNDER MOSTLY CLOUDY TO PARTLY CLOUDY SKIES WITH TEMPS
BACK ABOVE NORMAL AHEAD OF THE FRONT.
TONIGHT...DRY AIR WILL FILTER IN FROM THE WEST BEHIND THE FRONT.
POPS WILL TAPER OFF...LINGERING THRU THE EVENING ALONG THE TN BORDER
DUE TO UPSLOPE NWLY FLOW. LOWS WILL BE A COUPLE CATEGORIES ABOVE
NORMAL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM MONDAY...THINGS DRY OUT TUE AS DRY HIGH PRESSURE BUILDS
IN FROM THE WEST. EXPECT A MILD AND BREEZY DAY WITH HIGHS UP TO 5
DEGREES BELOW NORMAL. A BROAD AND LOW AMPLITUDE UPPER TROF SETS UP
ACROSS THE AREA FOR WED. WEAK SHORT WAVES MOVING THRU THE TROF WILL
HELP PUSH A WEAK COLD FRONT INTO THE AREA WED AND SOUTH OF THE AREA
WED NITE. THERE IS NOT A LOT OF DEEP MOISTURE WITH THIS SYSTEM AND
THE FORCING IS WEAK. THEREFORE...EXPECT SCT SHRA NEAR THE TN BORDER
WHERE THE MOISTURE IS DEEPEST AND WLY FLOW WILL HELP INCREASE
FORCING. ELSEWHERE...ONLY ISOLATED SHRA ARE EXPECTED...WITH LITTLE
CHC OF PRECIP SOUTH OF I-85. HIGHS WILL RISE TO NEAR NORMAL WED...
WITH LOWS NEAR NORMAL TUE NITE AND ABOVE NORMAL WED NITE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 AM MONDAY...AN UPPER TROF AXIS WILL SLIDE EAST OF THE AREA
THURSDAY ALLOWING FLAT RIDGING TO BUILD IN ON FRI. A SHORT WAVE
CROSSES THE AREA SATURDAY WITH ANOTHER BROAD AND LOW AMPLITUDE UPPER
TROF DEVELOPING ON SUNDAY.
HIGH PRESSURE BRIEFLY RETURNS TO THE AREA FRI BEFORE A STRONGER
STORM SYSTEM MOVES IN ON SATURDAY. PRECIP CHC SLOWLY RAMPS UP FRIDAY
WITH POTENTIALLY HEAVY PRECIP ON SATURDAY. DRY HIGH PRESSURE RETURNS
FOR SUNDAY. NEAR NORMAL HIGHS THURSDAY...FALL BELOW NORMAL FOR THE
REST OF THE PERIOD. LOWS BOUNCE AROUND FROM NEAR TO A LITTLE ABOVE
NORMAL.
&&
.AVIATION /17Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...GUSTY SSW WINDS AHEAD OF AN APPROACHING COLD
FRONT WILL CONTINUE THIS AFTERNOON AS CU FIELD THICKENS AND EXPANDS.
THUNDERSTORM CVRG WILL ALSO CONTINUE TO BLOSSOM WITH TIME AND GIVEN
THE EXPECTED CVRG...A TEMPO TSRA WILL BE INCLUDED AT ALL TERMINAL
LOCATIONS ALONG WITH CIGS OCCASIONALLY DIPPING DIPPING TO MVFR.
CONVECTION ALLOWING MODELS DIMINISH TSTM CVRG 21-23Z TODAY FOLLOWED
BY LLVL DRYING/DROPPING SFC DWPTS AND THE INFLUX OF POST-FRONTAL
AIR. A WIND SHIFT TO WEST IS EXPECTED THIS EVENING AND GUSTS WILL
DROP OFF. CLEARING AND VFR CONDITIONS ARE ON TAP OVERNIGHT AND INTO
TUESDAY MORNING.
OUTLOOK...DRY HIGH PRESSURE WILL BUILD IN ACROSS THE REGION FOR THE
MIDDLE OF THE WEEK...LEADING TO LOW PRECIP/RESTRICTION CHANCES.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-12Z
KCLT MED 60% HIGH 100% HIGH 100% HIGH 100%
KGSP MED 60% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU MED 60% HIGH 100% HIGH 100% HIGH 100%
KAND MED 70% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...ARK/CSH
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK/CSH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1023 AM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY BRINGING ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. DRY HIGH PRESSURE BUILDS IN FOR TUESDAY
AND WEDNESDAY. ANOTHER COLD FRONT WILL PUSH IN FROM THE NORTHWEST ON
THURSDAY...POSSIBLY BRINGING SHOWERS BACK TO THE AREA. A STRONGER
STORM SYSTEM WILL MOVE IN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM...GUSTY TSTMS...WHAT APPEAR TO BE DRIVEN BY MCV...
SHOULD TRANSLATE QUICKLY EAST OF THE CWFA BY 15 UTC. IT SEEMS
LIKE THERE WILL BE SVRL HOURS OF ECHO FREE CONDITIONS ACRS THE
CWFA. WITHIN THE BROAD PRE-COLD FRONTAL ENVIRONMENT...PROGRESSIVE
DESTABILIZATION IS EXPECTED THROUGH THE AFTERNOON. THE NEWLY POSTED
12 UTC NAM AND CONVECTION ALLOWING MODELS EXPECTEDLY RESPOND
FAVORABLY WITHIN LLVL FRONTAL CONVERGENCE ZONE...PROGGING WIDESPREAD
DEEP CONVECTION. FAVORABLE SHEAR PROFILES LEND SUPPORT TO THE
PROBABILITY OF DISCRETE STORMS IN THE PIEDMONT LATER TODAY.
AS OF 645 AM...WELL THE NEAR TERM MODELS AND CAMS ARE NOT DOING VERY
WELL WITH THE CONVECTION ENTERING OUR WESTERN ZONES EARLY THIS
MORNING. HAVE BUMPED UP POP IN THE WEST. STILL EXPECT WEAKENING AS
THE REMNANT PRECIP CROSSES THE AREA THRU THE MORNING HOURS. CANNOT
RULE OUT A STRONG OR MARGINALLY SEVERE STORM EARLY ON...BUT
OTHERWISE JUST SOME CG LIGHTNING AND DOWNPOURS WITH THAT ACTIVITY.
THE REST OF THE FCST WAS LEFT UNCHANGED.
AS OF 330 AM...IN THE IMMEDIATE NEAR TERM...THE RADAR HAS GONE INTO
CLEAR AIR MODE...AS A LEAD SHORTWAVE HAS EXITED TO THE NE WITHIN
DEEP LAYER SWLY FLOW. A QUASI-LINEAR MCS IS CURRENTLY CROSSING
CENTRAL TN AND NRN AL. GUIDANCE SEEMS TO BE UNDERESTIMATING THE
STRENGTH/PERSISTENCE OF THIS SYSTEM. THE LATEST RAP ANALYSIS SHOWS
500-1000 J/KG OF MUCAPE WITH 35-45 KTS OF EFFECTIVE SHEAR DOWNSTREAM
OF THIS CLUSTER. THIS RESULTS IN A /MCS MAINTENANCE/ PROB AT 70-80
PCT. SO IT IS NOW EXPECTED THAT THESE STORMS (WHILE STILL ON A
GRADUAL WEAKENING TREND) WILL LIKELY STILL SURVIVE INTO THE NC MTNS
EARLY THIS MORNING. GIVEN THE CURRENT STATE...CANNOT RULE OUT A
STRONG OR SEVERE STORM OR TWO...ESP IN GRAHAM/SWAIN...WHEN THE LINE
GETS INTO THE CWFA. FROM THERE...IT/S DIFFICULT TO SAY HOW MUCH
PRECIP WILL LINGER ACRS THE CWFA THIS MORNING. I HAVE BUMPED UP POP
IN THE WRN MTNS...BUT KEEP JUST A SHOTGUN CHC POP FOR THE REST OF
THE AREA THIS MORNING.
LATER TODAY...GUIDANCE IN GOOD AGREEMENT ON ANOTHER SPOKE OF
VORTICITY ROTATING AROUND THE BROAD CYCLONICALLY CURVED
FLOW...CROSSING THE CWFA FROM THE SOUTHWEST DURING THE PEAK-HEATING
AFTN HOURS. MEANWHILE...A COLD FRONT WILL PUSH INTO THE AREA THIS
AFTN. THE FRONT LOOKS TO ONLY HAVE MODEST LLVL CONVERGENCE.
HOWEVER...GIVEN THE STEEP MID LVL LAPSE RATES AND LINGERING BL
MOISTURE (DEWPTS IN THE MID 60S ACRS THE PIEDMONT). FAIRLY CONFIDENT
IN AT LEAST 40-50 PCT COVERAGE OF CONVECTION...MAYBE HIGHER TO THE
EAST. THE FCST SNDGS SHOW LONG BUT SLIGHTLY CURVED HODOGRAPHS WITH
1500-2500 J/KG OF UNCAPPED SBCAPE. SO EXPECT SOMEWHAT DISCRETE
STORMS INITIALLY...WITH POTENTIAL FOR SUPERCELLS. DEFINITELY WILL
BE A DAMAGING WIND AND HAIL THREAT...WITH AN ISOLD TORNADO THREAT
ACRS THE PIEDMONT THIS AFTN. THE HIGH RES MODELS DO NOT SEEM THAT
IMPRESSED WITH COVERAGE OR INTENSITY. I/M NOT SURE WHAT IS LIMITING
THEIR CONVECTION EXPECT FOR PERHAPS LACK OF DEEPER MOISTURE. THE NEW
DAY 1 CONVECTIVE OUTLOOK STILL HAS ALL AREAS EAST OF THE MTNS IN THE
SLGT RISK...AND A MARGINAL RISK FOR THE MTNS. OTHERWISE...IT WILL BE
BREEZY TODAY UNDER MOSTLY CLOUDY TO PARTLY CLOUDY SKIES WITH TEMPS
BACK ABOVE NORMAL AHEAD OF THE FRONT.
TONIGHT...DRY AIR WILL FILTER IN FROM THE WEST BEHIND THE FRONT.
POPS WILL TAPER OFF...LINGERING THRU THE EVENING ALONG THE TN BORDER
DUE TO UPSLOPE NWLY FLOW. LOWS WILL BE A COUPLE CATEGORIES ABOVE
NORMAL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM MONDAY...THINGS DRY OUT TUE AS DRY HIGH PRESSURE BUILDS
IN FROM THE WEST. EXPECT A MILD AND BREEZY DAY WITH HIGHS UP TO 5
DEGREES BELOW NORMAL. A BROAD AND LOW AMPLITUDE UPPER TROF SETS UP
ACROSS THE AREA FOR WED. WEAK SHORT WAVES MOVING THRU THE TROF WILL
HELP PUSH A WEAK COLD FRONT INTO THE AREA WED AND SOUTH OF THE AREA
WED NITE. THERE IS NOT A LOT OF DEEP MOISTURE WITH THIS SYSTEM AND
THE FORCING IS WEAK. THEREFORE...EXPECT SCT SHRA NEAR THE TN BORDER
WHERE THE MOISTURE IS DEEPEST AND WLY FLOW WILL HELP INCREASE
FORCING. ELSEWHERE...ONLY ISOLATED SHRA ARE EXPECTED...WITH LITTLE
CHC OF PRECIP SOUTH OF I-85. HIGHS WILL RISE TO NEAR NORMAL WED...
WITH LOWS NEAR NORMAL TUE NITE AND ABOVE NORMAL WED NITE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 AM MONDAY...AN UPPER TROF AXIS WILL SLIDE EAST OF THE AREA
THURSDAY ALLOWING FLAT RIDGING TO BUILD IN ON FRI. A SHORT WAVE
CROSSES THE AREA SATURDAY WITH ANOTHER BROAD AND LOW AMPLITUDE UPPER
TROF DEVELOPING ON SUNDAY.
HIGH PRESSURE BRIEFLY RETURNS TO THE AREA FRI BEFORE A STRONGER
STORM SYSTEM MOVES IN ON SATURDAY. PRECIP CHC SLOWLY RAMPS UP FRIDAY
WITH POTENTIALLY HEAVY PRECIP ON SATURDAY. DRY HIGH PRESSURE RETURNS
FOR SUNDAY. NEAR NORMAL HIGHS THURSDAY...FALL BELOW NORMAL FOR THE
REST OF THE PERIOD. LOWS BOUNCE AROUND FROM NEAR TO A LITTLE ABOVE
NORMAL.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...PLENTY OF IFR TO MVFR LVL STRATUS ACRS THE
PIEDMONT THIS MORNING...SHUD LIFT AND SCATTER OUT TO A VFR LVL
CUMULUS DECK BY 14-16Z TIME FRAME. A BAND OF WEAKENING SHRA AND TSRA
ARE ENTERING WRN NC AT THE TIME OF THE TAF ISSUANCE. THE 06Z NAM
SEEMS TO HAVE THE BEST HANDLE ON THIS CONVECTION...CARRYING AN AREA
OF -RA ACRS THE NC MTNS AND FOOTHILLS...CLIPPING THE UPSTATE SITES
THIS MORNING. WILL MENTION SHRA AT KAVL AND VCTS AT KAND. NOT ENUF
CONFIDENCE ON ANY IMPACT AT GMU/GSP/HKY TO MENTION. BY MIDDAY...SW
WINDS WILL BECOME GUSTY ACRS THE ENTIRE AREA. A COLD FRONT WILL BE
PUSHING IN FROM THE WEST THIS AFTN...WITH GENERALLY ISOLD TO WIDELY
SCATTERED TSRA EXPECTED TO DEVELOP JUST OUT AHEAD OF THE FRONT ACRS
THE PIEDMONT. WILL CONTINUE TO MENTION PROB30 STARTING AT 21Z. WINDS
WILL SHIFT TO WNW EAST OF THE MTNS...AND NW AT KAVL BEHIND THE FRONT
THIS EVENING...GRADUALLY DIMINISHING OVERNIGHT.
OUTLOOK...DRY HIGH PRESSURE WILL BUILD IN ACROSS THE REGION FOR THE
MIDDLE OF THE WEEK...LEADING TO LOW PRECIP/RESTRICTION CHANCES.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-12Z
KCLT MED 79% HIGH 100% HIGH 100% HIGH 100%
KGSP MED 79% HIGH 87% HIGH 100% HIGH 100%
KAVL HIGH 93% HIGH 100% HIGH 100% HIGH 100%
KHKY MED 79% HIGH 81% HIGH 100% HIGH 100%
KGMU MED 76% HIGH 92% HIGH 100% HIGH 100%
KAND MED 76% HIGH 98% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...ARK/CSH
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
655 AM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY BRINGING ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. DRY HIGH PRESSURE BUILDS IN FOR TUESDAY
AND WEDNESDAY. ANOTHER COLD FRONT WILL PUSH IN FROM THE NORTHWEST ON
THURSDAY...POSSIBLY BRINGING SHOWERS BACK TO THE AREA. A STRONGER
STORM SYSTEM WILL MOVE IN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM...WELL THE NEAR TERM MODELS AND CAMS ARE NOT DOING VERY
WELL WITH THE CONVECTION ENTERING OUR WESTERN ZONES EARLY THIS
MORNING. HAVE BUMPED UP POP IN THE WEST. STILL EXPECT WEAKENING AS
THE REMNANT PRECIP CROSSES THE AREA THRU THE MORNING HOURS. CANNOT
RULE OUT A STRONG OR MARGINALLY SEVERE STORM EARLY ON...BUT
OTHERWISE JUST SOME CG LIGHTNING AND DOWNPOURS WITH THAT ACTIVITY.
THE REST OF THE FCST WAS LEFT UNCHANGED.
AS OF 330 AM...IN THE IMMEDIATE NEAR TERM...THE RADAR HAS GONE INTO
CLEAR AIR MODE...AS A LEAD SHORTWAVE HAS EXITED TO THE NE WITHIN
DEEP LAYER SWLY FLOW. A QUASI-LINEAR MCS IS CURRENTLY CROSSING
CENTRAL TN AND NRN AL. GUIDANCE SEEMS TO BE UNDERESTIMATING THE
STRENGTH/PERSISTENCE OF THIS SYSTEM. THE LATEST RAP ANALYSIS SHOWS
500-1000 J/KG OF MUCAPE WITH 35-45 KTS OF EFFECTIVE SHEAR DOWNSTREAM
OF THIS CLUSTER. THIS RESULTS IN A /MCS MAINTENANCE/ PROB AT 70-80
PCT. SO IT IS NOW EXPECTED THAT THESE STORMS (WHILE STILL ON A
GRADUAL WEAKENING TREND) WILL LIKELY STILL SURVIVE INTO THE NC MTNS
EARLY THIS MORNING. GIVEN THE CURRENT STATE...CANNOT RULE OUT A
STRONG OR SEVERE STORM OR TWO...ESP IN GRAHAM/SWAIN...WHEN THE LINE
GETS INTO THE CWFA. FROM THERE...IT/S DIFFICULT TO SAY HOW MUCH
PRECIP WILL LINGER ACRS THE CWFA THIS MORNING. I HAVE BUMPED UP POP
IN THE WRN MTNS...BUT KEEP JUST A SHOTGUN CHC POP FOR THE REST OF
THE AREA THIS MORNING.
LATER TODAY...GUIDANCE IN GOOD AGREEMENT ON ANOTHER SPOKE OF
VORTICITY ROTATING AROUND THE BROAD CYCLONICALLY CURVED
FLOW...CROSSING THE CWFA FROM THE SOUTHWEST DURING THE PEAK-HEATING
AFTN HOURS. MEANWHILE...A COLD FRONT WILL PUSH INTO THE AREA THIS
AFTN. THE FRONT LOOKS TO ONLY HAVE MODEST LLVL CONVERGENCE.
HOWEVER...GIVEN THE STEEP MID LVL LAPSE RATES AND LINGERING BL
MOISTURE (DEWPTS IN THE MID 60S ACRS THE PIEDMONT). FAIRLY CONFIDENT
IN AT LEAST 40-50 PCT COVERAGE OF CONVECTION...MAYBE HIGHER TO THE
EAST. THE FCST SNDGS SHOW LONG BUT SLIGHTLY CURVED HODOGRAPHS WITH
1500-2500 J/KG OF UNCAPPED SBCAPE. SO EXPECT SOMEWHAT DISCRETE
STORMS INITIALLY...WITH POTENTIAL FOR SUPERCELLS. DEFINITELY WILL
BE A DAMAGING WIND AND HAIL THREAT...WITH AN ISOLD TORNADO THREAT
ACRS THE PIEDMONT THIS AFTN. THE HIGH RES MODELS DO NOT SEEM THAT
IMPRESSED WITH COVERAGE OR INTENSITY. I/M NOT SURE WHAT IS LIMITING
THEIR CONVECTION EXPECT FOR PERHAPS LACK OF DEEPER MOISTURE. THE NEW
DAY 1 CONVECTIVE OUTLOOK STILL HAS ALL AREAS EAST OF THE MTNS IN THE
SLGT RISK...AND A MARGINAL RISK FOR THE MTNS. OTHERWISE...IT WILL BE
BREEZY TODAY UNDER MOSTLY CLOUDY TO PARTLY CLOUDY SKIES WITH TEMPS
BACK ABOVE NORMAL AHEAD OF THE FRONT.
TONIGHT...DRY AIR WILL FILTER IN FROM THE WEST BEHIND THE FRONT.
POPS WILL TAPER OFF...LINGERING THRU THE EVENING ALONG THE TN BORDER
DUE TO UPSLOPE NWLY FLOW. LOWS WILL BE A COUPLE CATEGORIES ABOVE
NORMAL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM MONDAY...THINGS DRY OUT TUE AS DRY HIGH PRESSURE BUILDS
IN FROM THE WEST. EXPECT A MILD AND BREEZY DAY WITH HIGHS UP TO 5
DEGREES BELOW NORMAL. A BROAD AND LOW AMPLITUDE UPPER TROF SETS UP
ACROSS THE AREA FOR WED. WEAK SHORT WAVES MOVING THRU THE TROF WILL
HELP PUSH A WEAK COLD FRONT INTO THE AREA WED AND SOUTH OF THE AREA
WED NITE. THERE IS NOT A LOT OF DEEP MOISTURE WITH THIS SYSTEM AND
THE FORCING IS WEAK. THEREFORE...EXPECT SCT SHRA NEAR THE TN BORDER
WHERE THE MOISTURE IS DEEPEST AND WLY FLOW WILL HELP INCREASE
FORCING. ELSEWHERE...ONLY ISOLATED SHRA ARE EXPECTED...WITH LITTLE
CHC OF PRECIP SOUTH OF I-85. HIGHS WILL RISE TO NEAR NORMAL WED...
WITH LOWS NEAR NORMAL TUE NITE AND ABOVE NORMAL WED NITE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 AM MONDAY...AN UPPER TROF AXIS WILL SLIDE EAST OF THE AREA
THURSDAY ALLOWING FLAT RIDGING TO BUILD IN ON FRI. A SHORT WAVE
CROSSES THE AREA SATURDAY WITH ANOTHER BROAD AND LOW AMPLITUDE UPPER
TROF DEVELOPING ON SUNDAY.
HIGH PRESSURE BRIEFLY RETURNS TO THE AREA FRI BEFORE A STRONGER
STORM SYSTEM MOVES IN ON SATURDAY. PRECIP CHC SLOWLY RAMPS UP FRIDAY
WITH POTENTIALLY HEAVY PRECIP ON SATURDAY. DRY HIGH PRESSURE RETURNS
FOR SUNDAY. NEAR NORMAL HIGHS THURSDAY...FALL BELOW NORMAL FOR THE
REST OF THE PERIOD. LOWS BOUNCE AROUND FROM NEAR TO A LITTLE ABOVE
NORMAL.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...PLENTY OF IFR TO MVFR LVL STRATUS ACRS THE
PIEDMONT THIS MORNING...SHUD LIFT AND SCATTER OUT TO A VFR LVL
CUMULUS DECK BY 14-16Z TIME FRAME. A BAND OF WEAKENING SHRA AND TSRA
ARE ENTERING WRN NC AT THE TIME OF THE TAF ISSUANCE. THE 06Z NAM
SEEMS TO HAVE THE BEST HANDLE ON THIS CONVECTION...CARRYING AN AREA
OF -RA ACRS THE NC MTNS AND FOOTHILLS...CLIPPING THE UPSTATE SITES
THIS MORNING. WILL MENTION SHRA AT KAVL AND VCTS AT KAND. NOT ENUF
CONFIDENCE ON ANY IMPACT AT GMU/GSP/HKY TO MENTION. BY MIDDAY...SW
WINDS WILL BECOME GUSTY ACRS THE ENTIRE AREA. A COLD FRONT WILL BE
PUSHING IN FROM THE WEST THIS AFTN...WITH GENERALLY ISOLD TO WIDELY
SCATTERED TSRA EXPECTED TO DEVELOP JUST OUT AHEAD OF THE FRONT ACRS
THE PIEDMONT. WILL CONTINUE TO MENTION PROB30 STARTING AT 21Z. WINDS
WILL SHIFT TO WNW EAST OF THE MTNS...AND NW AT KAVL BEHIND THE FRONT
THIS EVENING...GRADUALLY DIMINISHING OVERNIGHT.
OUTLOOK...DRY HIGH PRESSURE WILL BUILD IN ACROSS THE REGION FOR THE
MIDDLE OF THE WEEK...LEADING TO LOW PRECIP/RESTRICTION CHANCES.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-06Z
KCLT MED 78% MED 69% HIGH 100% HIGH 100%
KGSP HIGH 85% MED 69% LOW 57% HIGH 100%
KAVL HIGH 93% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 87% HIGH 100% HIGH 100%
KGMU HIGH 85% MED 69% HIGH 100% HIGH 100%
KAND HIGH 85% MED 75% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...ARK
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
353 AM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY BRINGING ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. DRY HIGH PRESSURE BUILDS IN FOR TUESDAY
AND WEDNESDAY. ANOTHER COLD FRONT WILL PUSH IN FROM THE NORTHWEST ON
THURSDAY...POSSIBLY BRINGING SHOWERS BACK TO THE AREA. A STRONGER
STORM SYSTEM WILL MOVE IN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM...IN THE IMMEDIATE NEAR TERM...THE RADAR HAS GONE INTO
CLEAR AIR MODE...AS A LEAD SHORTWAVE HAS EXITED TO THE NE WITHIN
DEEP LAYER SWLY FLOW. A QUASI-LINEAR MCS IS CURRENTLY CROSSING
CENTRAL TN AND NRN AL. GUIDANCE SEEMS TO BE UNDERESTIMATING THE
STRENGTH/PERSISTENCE OF THIS SYSTEM. THE LATEST RAP ANALYSIS SHOWS
500-1000 J/KG OF MUCAPE WITH 35-45 KTS OF EFFECTIVE SHEAR DOWNSTREAM
OF THIS CLUSTER. THIS RESULTS IN A /MCS MAINTENANCE/ PROB AT 70-80
PCT. SO IT IS NOW EXPECTED THAT THESE STORMS (WHILE STILL ON A
GRADUAL WEAKENING TREND) WILL LIKELY STILL SURVIVE INTO THE NC MTNS
EARLY THIS MORNING. GIVEN THE CURRENT STATE...CANNOT RULE OUT A
STRONG OR SEVERE STORM OR TWO...ESP IN GRAHAM/SWAIN...WHEN THE LINE
GETS INTO THE CWFA. FROM THERE...IT/S DIFFICULT TO SAY HOW MUCH
PRECIP WILL LINGER ACRS THE CWFA THIS MORNING. I HAVE BUMPED UP POP
IN THE WRN MTNS...BUT KEEP JUST A SHOTGUN CHC POP FOR THE REST OF
THE AREA THIS MORNING.
LATER TODAY...GUIDANCE IN GOOD AGREEMENT ON ANOTHER SPOKE OF
VORTICITY ROTATING AROUND THE BROAD CYCLONICALLY CURVED
FLOW...CROSSING THE CWFA FROM THE SOUTHWEST DURING THE PEAK-HEATING
AFTN HOURS. MEANWHILE...A COLD FRONT WILL PUSH INTO THE AREA THIS
AFTN. THE FRONT LOOKS TO ONLY HAVE MODEST LLVL CONVERGENCE.
HOWEVER...GIVEN THE STEEP MID LVL LAPSE RATES AND LINGERING BL
MOISTURE (DEWPTS IN THE MID 60S ACRS THE PIEDMONT). FAIRLY CONFIDENT
IN AT LEAST 40-50 PCT COVERAGE OF CONVECTION...MAYBE HIGHER TO THE
EAST. THE FCST SNDGS SHOW LONG BUT SLIGHTLY CURVED HODOGRAPHS WITH
1500-2500 J/KG OF UNCAPPED SBCAPE. SO EXPECT SOMEWHAT DISCRETE
STORMS INITIALLY...WITH POTENTIAL FOR SUPERCELLS. DEFINITELY WILL
BE A DAMAGING WIND AND HAIL THREAT...WITH AN ISOLD TORNADO THREAT
ACRS THE PIEDMONT THIS AFTN. THE HIGH RES MODELS DO NOT SEEM THAT
IMPRESSED WITH COVERAGE OR INTENSITY. I/M NOT SURE WHAT IS LIMITING
THEIR CONVECTION EXPECT FOR PERHAPS LACK OF DEEPER MOISTURE. THE NEW
DAY 1 CONVECTIVE OUTLOOK STILL HAS ALL AREAS EAST OF THE MTNS IN THE
SLGT RISK...AND A MARGINAL RISK FOR THE MTNS. OTHERWISE...IT WILL BE
BREEZY TODAY UNDER MOSTLY CLOUDY TO PARTLY CLOUDY SKIES WITH TEMPS
BACK ABOVE NORMAL AHEAD OF THE FRONT.
TONIGHT...DRY AIR WILL FILTER IN FROM THE WEST BEHIND THE FRONT.
POPS WILL TAPER OFF...LINGERING THRU THE EVENING ALONG THE TN BORDER
DUE TO UPSLOPE NWLY FLOW. LOWS WILL BE A COUPLE CATEGORIES ABOVE
NORMAL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM MONDAY...THINGS DRY OUT TUE AS DRY HIGH PRESSURE BUILDS
IN FROM THE WEST. EXPECT A MILD AND BREEZY DAY WITH HIGHS UP TO 5
DEGREES BELOW NORMAL. A BROAD AND LOW AMPLITUDE UPPER TROF SETS UP
ACROSS THE AREA FOR WED. WEAK SHORT WAVES MOVING THRU THE TROF WILL
HELP PUSH A WEAK COLD FRONT INTO THE AREA WED AND SOUTH OF THE AREA
WED NITE. THERE IS NOT A LOT OF DEEP MOISTURE WITH THIS SYSTEM AND
THE FORCING IS WEAK. THEREFORE...EXPECT SCT SHRA NEAR THE TN BORDER
WHERE THE MOISTURE IS DEEPEST AND WLY FLOW WILL HELP INCREASE
FORCING. ELSEWHERE...ONLY ISOLATED SHRA ARE EXPECTED...WITH LITTLE
CHC OF PRECIP SOUTH OF I-85. HIGHS WILL RISE TO NEAR NORMAL WED...
WITH LOWS NEAR NORMAL TUE NITE AND ABOVE NORMAL WED NITE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 AM MONDAY...AN UPPER TROF AXIS WILL SLIDE EAST OF THE AREA
THURSDAY ALLOWING FLAT RIDGING TO BUILD IN ON FRI. A SHORT WAVE
CROSSES THE AREA SATURDAY WITH ANOTHER BROAD AND LOW AMPLITUDE UPPER
TROF DEVELOPING ON SUNDAY.
HIGH PRESSURE BRIEFLY RETURNS TO THE AREA FRI BEFORE A STRONGER
STORM SYSTEM MOVES IN ON SATURDAY. PRECIP CHC SLOWLY RAMPS UP FRIDAY
WITH POTENTIALLY HEAVY PRECIP ON SATURDAY. DRY HIGH PRESSURE RETURNS
FOR SUNDAY. NEAR NORMAL HIGHS THURSDAY...FALL BELOW NORMAL FOR THE
REST OF THE PERIOD. LOWS BOUNCE AROUND FROM NEAR TO A LITTLE ABOVE
NORMAL.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...PLENTY OF LLVL MOISTURE ACRS THE AREA WITH
AN INCREASING SWLY LLVL JET OVERNIGHT SHUD RESULT IN A FAIR AMOUNT
OF LIFR TO MVFR CIGS THRU DAYBREAK. THERE WILL BE A BAND OF DECAYING
CONVECTION APPROACHING THE AREA FROM THE WEST DURING THE PRE-DAWN
HOURS. HOWEVER...GUIDANCE IN GOOD AGREEMENT THAT THE PRECIP SHUD
PRETTY MUCH FIZZLE BY THE TIME IT PUSHES INTO THE NC MTNS AROUND
DAYBREAK. DURING THE DAY TODAY...STRATUS SHUD MIX/SCT INTO AN MVFR
TO LOW VFR CU DECK...WITH INCREASING INSTBY EXPECTED BY THE AFTN.
EXPECTING MAINLY SCATTERED SHRA AND TSRA TO DEVELOP THIS AFTN...SO
WILL KEEP A PROB30 FOR ALL SITES. WINDS WILL BECOME QUITE GUSTY OUT
OF THE SW...WITH GUSTS FREQUENTLY IN THE 20-25 KT RANGE EXPECTED. A
COLD FRONT WILL PUSH THRU THE AREA LATE AFTN INTO THE
EVENING...ENDING THE CONVECTION CHCS AND SHIFTING WINDS TO W AND NW
BY THE END OF THE TAF PERIOD. DRY AIR SHUD FILTER OUT ANY LOW
CLOUDS...AND ONLY CIRRUS EXPECTED THIS EVENING.
OUTLOOK...DRY HIGH PRESSURE WILL BUILD IN ACROSS THE REGION FOR THE
MIDDLE OF THE WEEK...LEADING TO LOW PRECIP/RESTRICTION CHANCES.
CONFIDENCE TABLE...
08-14Z 14-20Z 20-02Z 02-06Z
KCLT MED 75% HIGH 87% HIGH 100% HIGH 100%
KGSP MED 64% MED 79% HIGH 89% HIGH 100%
KAVL MED 73% HIGH 95% MED 65% HIGH 90%
KHKY MED 60% HIGH 82% HIGH 98% HIGH 100%
KGMU LOW 50% MED 78% HIGH 89% HIGH 100%
KAND MED 64% MED 79% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...ARK
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1101 PM CDT TUE APR 21 2015
.DISCUSSION...
UPDATED FOR 06Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 928 PM CDT TUE APR 21 2015/
UPDATE...
SHOWERS AHEAD OF AN APPROACHING COLD FRONT ARE MOVING INTO
NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND EXTREME NORTHWEST
TENNESSEE AT THIS TIME. LATEST HRRR SHOWS SHOWERS DISSIPATING
AROUND MIDNIGHT. UPDATED EARLIER TO GO WITH LIKELY POPS IN AREAS
NEAR THE MO/AR AND TN/KY BORDERS. ADDITIONAL DEVELOPMENT ALONG THE
FRONT MAY OCCUR JUST BEFORE SUNRISE. WILL LIKELY ISSUE ANOTHER
UPDATE AROUND MIDNIGHT TO ADJUST POPS FURTHER. REST OF FORECAST
LOOKS GOOD.
KRM
DISCUSSION... /ISSUED 349 PM CDT TUE APR 21 2015/
AS OF 3PM...
LATEST SURFACE ANALYSIS PLACES AN AREA OF HIGH
PRESSURE OVER THE GULF COAST STATES WITH A COLD FRONT STREWN
ACROSS THE IOWA AND MISSOURI BORDERS AND BACK THROUGH NEBRASKA.
TEMPERATURES ARE MILD ACROSS THE AREA WITH READINGS NEAR 70
DEGREES UNDER MOSTLY SUNNY SKIES. WINDS ARE MODERATELY GUSTY ALONG
AND WEST OF THE RIVER WITH SUSTAINED VALUES OF 10 TO 15 MPH WITH
GUSTS AS HIGH AS 30 MPH.
SHORT TERM...TONIGHT INTO THURSDAY...
A SPLIT FLOW REGIME WILL CONTINUE ACROSS THE COUNTRY KEEPING THE
WEATHER PATTERN UNSETTLED THROUGH THIS PERIOD. THE AFOREMENTIONED
COLD FRONT WILL APPROACH NORTHERN PORTIONS OF THE FA THIS
EVENING...WITH SHORT TERM MODEL GUIDANCE SHOWING A FEW SHOWERS AND
EMBEDDED THUNDERSTORMS DEVELOPING. COVERAGE WILL LIKELY BE SPARSE
AS MOISTURE IS LIMITED...EVIDENCED BY DEWPOINTS STILL ONLY IN THE
UPPER 30S. NEVERTHELESS...THESE STORMS WILL MOVE TO THE SOUTH
EAST BY TOMORROW MORNING AS THE FRONT SLOWLY SAGS SOUTHWARD. BY
WEDNESDAY AFTERNOON...IT APPEARS TO BE A MOSTLY DRY DAY ACROSS THE
REGION WITH THE EXCEPTION OF A FEW ISOLATED SHOWER AND
THUNDERSTORMS POSSIBLY FORMING ALONG THE WEAKENING FRONTAL
BOUNDARY. TEMPERATURES WILL BE SIMILAR TO TODAY WITH READINGS
NEAR 70 DEGREES.
BY WEDNESDAY NIGHT...
WEAK HIGH PRESSURE WILL BUILD IN FROM THE NORTH...WHILE AN MCS IS
EXPECTED TO DEVELOP OVER NORTH TEXAS AND TRANSIT THE ARKLATEX
REGION DURING THE OVERNIGHT HOURS. SOME UNCERTAINTY WITH HOW FAR
NORTH THE TRACK WILL GO...BUT DECIDED TO KEEP A CHANCE OF
THUNDERSTORMS ACROSS THE SOUTHERN HALF OF OUR FA WHERE THE
FAVORABLE ENVIRONMENT WOULD ULTIMATELY BE. CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THE AFTERNOON HOURS ON
THURSDAY BUT WILL BE SCATTERED AT BEST AS HIGH PRESSURE NUDGES ITS
WAY INTO THE REGION.
LONG TERM...FRIDAY INTO EARLY NEXT WEEK...
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE ON THE INCREASE
ONCE AGAIN FRIDAY MORNING AS HIGH PRESSURE PUSHES EAST AND A WARM
FRONT BEGINS TO PUSH NORTHWARD ACROSS THE AREA. OUT WEST...A
SHORTWAVE TROUGH AND ASSOC SURFACE LOW WILL EJECT FROM THE FOUR
CORNERS AND WILL DEEPEN AS IT PUSHES INTO THE SOUTHERN PLAINS.
THE BEST CHANCES OF RAIN WILL EXIST FRIDAY NIGHT INTO SATURDAY AS
THE LOW PRESSURE SYSTEM MOVES DIRECTLY INTO THE MID-SOUTH LATE
FRIDAY NIGHT INTO SATURDAY. THE BEST INSTABILITY WILL RESIDE TO
THE SOUTH AND EAST OF OUR AREA...SO SEVERE WEATHER DOES NOT LOOK
TO BE AN ISSUE AT THIS POINT. ABOUT ONE HALF TO ONE INCH OF QPF IS
FORECAST THROUGH SATURDAY EVENING.
BY SUNDAY...HIGH PRESSURE AND UPPER LEVEL RIDGING WILL KEEP THE
MID-SOUTH DRY AND SEASONABLY WARM WITH HIGHS IN THE 70S. MORE
UNSETTLED WEATHER IS ANTICIPATED EARLY NEXT WEEK AS SPLIT FLOW
SETS UP AGAIN. TEMPERATURES WILL REMAIN NEAR NORMAL THROUGH THE
ENTIRE PERIOD.
AC3
&&
.AVIATION...
06Z TAFS
VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. AREA OF
SHRAS AHEAD OF AN APPROACHING COLD FRONT MOVING ACROSS NORTHERN
SECTIONS OF THE MIDSOUTH ATTM. THE ASSOCIATED WEAK GUST FRONT
WILL BRIEFLY TURN WINDS NWLY AT MKL WITH PERHAPS A SHRA ON
STATION. REMAINDER OF NIGHT WILL FEATURE SSW WINDS AROUND 10 KTS
AT KMEM...KJBR AND KMKL...LIGHTER AT KTUP. COLD FRONT WILL MOVE
THROUGH ON MONDAY. A FEW SHRA ARE POSSIBLE AT KJBR AND KMKL BUT
NOT WORTHY OF VCSH YET. OTRW WINDS WILL SHIFT AROUND TO THE NW/N
AT 10 KTS. SHRAS AND SOME LOWER CLOUDS WILL BEGIN APPROACHING FROM
THE WEST TOWARD THE END OF THE PERIOD AND ADDED A VCSH AND A
BKN050 DECK AT KJBR/KMEM AROUND 23/05Z.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
928 PM CDT TUE APR 21 2015
.UPDATE...
SHOWERS AHEAD OF AN APPROACHING COLD FRONT ARE MOVING INTO
NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND EXTREME NORTHWEST
TENNESSEE AT THIS TIME. LATEST HRRR SHOWS SHOWERS DISSIPATING
AROUND MIDNIGHT. UPDATED EARLIER TO GO WITH LIKELY POPS IN AREAS
NEAR THE MO/AR AND TN/KY BORDERS. ADDITIONAL DEVELOPMENT ALONG THE
FRONT MAY OCCUR JUST BEFORE SUNRISE. WILL LIKELY ISSUE ANOTHER
UPDATE AROUND MIDNIGHT TO ADJUST POPS FURTHER. REST OF FORECAST
LOOKS GOOD.
KRM
&&
.DISCUSSION... /ISSUED 349 PM CDT TUE APR 21 2015/
AS OF 3PM...
LATEST SURFACE ANALYSIS PLACES AN AREA OF HIGH
PRESSURE OVER THE GULF COAST STATES WITH A COLD FRONT STREWN
ACROSS THE IOWA AND MISSOURI BORDERS AND BACK THROUGH NEBRASKA.
TEMPERATURES ARE MILD ACROSS THE AREA WITH READINGS NEAR 70
DEGREES UNDER MOSTLY SUNNY SKIES. WINDS ARE MODERATELY GUSTY ALONG
AND WEST OF THE RIVER WITH SUSTAINED VALUES OF 10 TO 15 MPH WITH
GUSTS AS HIGH AS 30 MPH.
SHORT TERM...TONIGHT INTO THURSDAY...
A SPLIT FLOW REGIME WILL CONTINUE ACROSS THE COUNTRY KEEPING THE
WEATHER PATTERN UNSETTLED THROUGH THIS PERIOD. THE AFOREMENTIONED
COLD FRONT WILL APPROACH NORTHERN PORTIONS OF THE FA THIS
EVENING...WITH SHORT TERM MODEL GUIDANCE SHOWING A FEW SHOWERS AND
EMBEDDED THUNDERSTORMS DEVELOPING. COVERAGE WILL LIKELY BE SPARSE
AS MOISTURE IS LIMITED...EVIDENCED BY DEWPOINTS STILL ONLY IN THE
UPPER 30S. NEVERTHELESS...THESE STORMS WILL MOVE TO THE SOUTH
EAST BY TOMORROW MORNING AS THE FRONT SLOWLY SAGS SOUTHWARD. BY
WEDNESDAY AFTERNOON...IT APPEARS TO BE A MOSTLY DRY DAY ACROSS THE
REGION WITH THE EXCEPTION OF A FEW ISOLATED SHOWER AND
THUNDERSTORMS POSSIBLY FORMING ALONG THE WEAKENING FRONTAL
BOUNDARY. TEMPERATURES WILL BE SIMILAR TO TODAY WITH READINGS
NEAR 70 DEGREES.
BY WEDNESDAY NIGHT...
WEAK HIGH PRESSURE WILL BUILD IN FROM THE NORTH...WHILE AN MCS IS
EXPECTED TO DEVELOP OVER NORTH TEXAS AND TRANSIT THE ARKLATEX
REGION DURING THE OVERNIGHT HOURS. SOME UNCERTAINTY WITH HOW FAR
NORTH THE TRACK WILL GO...BUT DECIDED TO KEEP A CHANCE OF
THUNDERSTORMS ACROSS THE SOUTHERN HALF OF OUR FA WHERE THE
FAVORABLE ENVIRONMENT WOULD ULTIMATELY BE. CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THE AFTERNOON HOURS ON
THURSDAY BUT WILL BE SCATTERED AT BEST AS HIGH PRESSURE NUDGES ITS
WAY INTO THE REGION.
LONG TERM...FRIDAY INTO EARLY NEXT WEEK...
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE ON THE INCREASE
ONCE AGAIN FRIDAY MORNING AS HIGH PRESSURE PUSHES EAST AND A WARM
FRONT BEGINS TO PUSH NORTHWARD ACROSS THE AREA. OUT WEST...A
SHORTWAVE TROUGH AND ASSOC SURFACE LOW WILL EJECT FROM THE FOUR
CORNERS AND WILL DEEPEN AS IT PUSHES INTO THE SOUTHERN PLAINS.
THE BEST CHANCES OF RAIN WILL EXIST FRIDAY NIGHT INTO SATURDAY AS
THE LOW PRESSURE SYSTEM MOVES DIRECTLY INTO THE MID-SOUTH LATE
FRIDAY NIGHT INTO SATURDAY. THE BEST INSTABILITY WILL RESIDE TO
THE SOUTH AND EAST OF OUR AREA...SO SEVERE WEATHER DOES NOT LOOK
TO BE AN ISSUE AT THIS POINT. ABOUT ONE HALF TO ONE INCH OF QPF IS
FORECAST THROUGH SATURDAY EVENING.
BY SUNDAY...HIGH PRESSURE AND UPPER LEVEL RIDGING WILL KEEP THE
MID-SOUTH DRY AND SEASONABLY WARM WITH HIGHS IN THE 70S. MORE
UNSETTLED WEATHER IS ANTICIPATED EARLY NEXT WEEK AS SPLIT FLOW
SETS UP AGAIN. TEMPERATURES WILL REMAIN NEAR NORMAL THROUGH THE
ENTIRE PERIOD.
AC3
&&
.AVIATION...
00Z TAFS
VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. SOME DATA
SHOWING SHRAS MOVING INTO NORTHERN SECTIONS OF THE MIDSOUTH THIS
EVENING. AIRMASS IS QUITE DRY AND CONFIDENCE IS NOT PARTICULARLY
HIGH SO LEFT OUT OF THE TAFS FOR NOW. EXPECT SSW WINDS AROUND 10
KTS OVERNIGHT AT KMEM...KMKL AND KJBR...LIGHTER AT KTUP. A COLD
FRONT WILL PUSH THROUGH ON WEDNESDAY. THIS WILL SHIFT WINDS AROUND
TO THE N/NW AT 10 KTS AND THERE WILL PROBABLY BE A DECK OF POST
FRONTAL STRATOCU FOR A COUPLE OF HRS AT EACH TAF SITE.
SJM
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1131 PM CDT SUN APR 19 2015
.UPDATE...FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION...06Z AVIATION DISCUSSION.
SEVERAL ADMS CONTINUE TO BE POSSIBLE THRU AT LEAST 20/15Z DUE TO CEILING
AND VSBY FLUCTUATIONS AND SHWR/TSTM IMPACTS. AT 06Z...CSV SHOULD BE
EXPERIENCING SHWRS/TSTMS WITH TEMPO MVFR VSBYS/CEILINGS POSSIBLE AS
LEADING CONVECTIVE LINE OF SHWRS/TSTMS WITH AN AREA OF SHWRS/SCT TSTMS
BEHIND MOVES INTO MID STATE. EXPECT THIS TO BE THE EXPERIENCE BY NO
LATER THAN 07Z BNA...WITH CSV AROUND 09Z. EXPECT THESE LINGERING SHWRS/SCT
TSTMS BEHIND MAIN CONVECTIVE LINE FOR AT LEAST A COUPLE OF HRS...WITH
MVFR FOG INDUCED VSBYS DEVELOPING ALSO. MVFR CEILINGS EXPECTED BY 20/15Z...
WITH VFR CEILINGS POSSIBLE 20/18Z AND AFTERWARDS. CEILING EROSION EXPECTED
AT ALL TAF SITES BY 21/02Z.
&&
.PREV DISCUSSION.../ISSUED 818 PM CDT SUN APR 19 2015/
DISCUSSION...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REMOVE WORDING IN THE ZONE
FORECAST PRODUCT FOR THE THRU LATE AFTERNOON GROUPING. HAVE ALSO UPDATED
TO MATCH CURRENT REGIONAL SFC OBS....SATELLITE...AND RADAR TRENDS ALONG
WITH TWEAKS TO HRLY TEMP...DEWPOINT...SKY...AND WIND SPEED/DIRECTION GRIDS.
AN EMBEDDED SHORTWAVE IN UPPER LEVEL TROUGH THAT IS MOVING ACROSS NW INTO
NC PORTIONS OF THE MID STATE THIS EVENING SHOULD CONTINUE MOVING NEWD WITH
DEVELOPING ISO STRONG TO SVR TSTMS ASSOCIATED WITH IT GENERALLY MOVING THIS
WAY ALSO...WITH THE POSSIBILITY OF SHWRS/TSTMS MOVING INTO THE NASHVILLE METRO
AREA PRESENTLY. EXPECT MAYBE SOME ISO SHWRS/TSTMS THRU 05Z ACROSS REST OF MID
STATE. MAIN CONCERN IS LINE OF SVR CONVECTION APPROACHING THE MS RIVER VALLEY
AS OF 01Z AND ITS POTENTIAL IMPACTS ON THE MID STATE`S WX AS IT IS EXPECTED TO
APPROACH THE TN RIVER VALLEY REGION OF THE MID STATE BY 05Z.
LATEST SHORT RANGE MODELS SHOWING BRUNT OF ACTIVITY CURRENTLY OVER AR MOVING
GENERALLY NE OF MID STATE AS IT APPROACHES THE TN RIVER VALLEY BY 05Z...WITH
CONVECTION PRESENTLY ACROSS SRN AR/NRN LA MOVING NEWD DRAGGING A LINE OF
SHWRS/TSTMS INTO THE MID STATE. 00Z MON KOHX SOUNDING PROFILE AND INDICES
SHOWING RELATIVELY LOW CAPE AND LOW SHEAR VALUES AS OF THIS TIME...WITH
MARGINAL INSTABILITY AND PCPN WATER VALUES AROUND 1.2 INCHES AND UNIDIRECTIONAL
SWLY FLOW SFC/ALOFT. MODEL SOUNDINGS SHOWING SOME ENHANCEMENTS IN INSTABILITY
AND SHEAR VALUES BETWEEN 06Z-09Z ACROSS WRN AND CENTRAL PORTIONS OF THE MID
STATE WITH UNIDIRECTIONAL SWLY FLOW SFC/ALOFT CONTINUING. 01Z CONVECTIVE
OUTLOOK CURTAILING THE SLIGHT RISK OF SVR TSTM AREA ACROSS THE PLATEAU COUNTIES
AND NOW GENERALLY LIMITING THIS POSSIBILITY TO LOCATIONS W OF THE PLATEAU.
SPC STILL EXPECTING SOME WEAKENING AS THIS CURRENT LINE OF SHWRS/TSTMS
APPROACHING THE MS RIVER MOVES EWD TONIGHT PER BOUNDARY LAYER DESTABILIZATION.
WITH THIS ALL SAID...DO EXPECT A QUASI-LINEAR LINE OF SHWRS/TSTMS TO MOVE
THRU THE MID STATE FROM AROUND 11 PM ONWARD W THRU THE EARLY MORNING HRS
E...BUT WILL IT STILL CONTAIN STRONG TO SVR CONVECTION WITH IT? ALL INDICATIONS
AT THIS TIME IS THAT IT IS BORDERLINE IF IT DOES OR NOT...AS SFC FRONT ITSELF
SHOULD APPROACH THE MS RIVER BY 06Z AND THEN PUSH EWD INTO THE MID STATE
JUST W OF PLATEAU BY 12Z...AS UPPER LEVEL TROUGHING BECOMES MORE PRONOUNCED
ACROSS THE MID STATE. THUS UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT
THE ABOVE REASONING/TIMINGS MENTIONED.
PREV DISCUSSION.../ISSUED 645 PM CDT SUN APR 19 2015/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
SEVERAL ADMS POSSIBLE THRU AT LEAST 20/15Z DUE TO CEILING AND VSBY
FLUCTUATIONS AND SHWR/TSTM IMPACTS. EXPECT BEST POTENTIAL FOR
SHWRS/TSTMS NEAR CKV THRU 20/05Z PER PROXIMITY TO UPPER LEVEL TROUGH
DYNAMICS. EXPECTING BRUNT OF SHWRS/TSTMS BETWEEN 20/05Z W - 20/11Z E
AS CONVECTIVE LINE MOVES THRU MID STATE. MVFR CEILINGS TO IFR VSBYS
WILL BE POSSIBLE DURING THIS TIME PERIOD...ESPECIALLY WITH ONSET OF
SHWR/TSTM ACTIVITY AT TAF SITES. EXPECT LINGERING SHWRS BEHIND MAIN
CONVECTIVE LINE FOR AT LEAST A COUPLE OF HRS...WITH MVFR FOG INDUCED
VSBYS DEVELOPING ALSO. MVFR CEILINGS EXPECTED BY 20/15Z...WITH VFR
CEILINGS POSSIBLE 20/18Z AND AFTERWARDS.
PREV DISCUSSION.../ISSUED 200 PM CDT SUN APR 19 2015/
DISCUSSION...SURFACE MAP AT 18Z SHOWS A 1000 MB LOW CENTERED OVER
SOUTHERN ILLINOIS, WITH A WARM FROM SITUATED TO OUR NORTH, A
COLD FRONT STILL WEST OF THE MISSISSIPPI RIVER, AND A PRE-FRONTAL
TROUGH JUST NOW CROSSING THE TENNESSEE RIVER THAT IS PROVIDING THE
FOCUS FOR A DEVELOPING LINE OF CONVECTION. SATELLITE IMAGERY IS
STARTING TO SHOW SOME BREAKS IN THE CLOUDS, ESPECIALLY WEST OF
NASHVILLE. LAPS SOUNDING FOR BNA AT 18Z SHOWS WEAK INSTABILITY,
WITH A LIFTED INDEX OF -3.3 AND A CAPE OF 962 J/KG. ATMOSPHERE
REMAINS SUFFICIENTLY MOIST, WITH PRECIPITABLE WATER OF 1.44 INCHES
AND A K-INDEX OF 34. LATEST HRRR SHOWS SCATTERED CELLS ACROSS
MIDDLE TENNESSEE UNTIL A MORE ORGANIZED LINE OF CONVECTION COMES
THROUGH WITH THE COLD FRONT BETWEEN 04Z AND 09Z. GIVEN THE TIMING
OF THE FRONT, THE POTENTIAL FOR WIDESPREAD SEVERE STORMS APPEARS
LOW, ALTHOUGH MIDDLE TENNESSEE DOES REMAIN UNDER A SLIGHT RISK OF
SEVERE WEATHER TODAY AND TONIGHT, SO ISOLATED CASES OF SEVERE
ACTIVITY ARE STILL POSSIBLE. AFTER A FEW LINGERING SHOWERS ON
MONDAY, LOOK FOR A BRIEF RESPITE ON TUESDAY BEFORE THE NEXT COLD
FRONT DROPS SOUTHWARD THROUGH MIDDLE TENNESSEE WEDNESDAY AND
THURSDAY. GIVEN THAT THE UPPER FLOW ACROSS THE REGION WILL REMAIN
EITHER CYCLONIC OR ZONAL, WARM ADVECTION WILL BE HARD TO COME BY,
AND SO TEMPERATURES DURING THE NEXT 7 DAYS WILL REMAIN AT OR BELOW
NORMAL.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
633 PM CDT TUE APR 21 2015
.AVIATION...
ISOLATED SHOWERS NEAR THE NM STATE LINE WEST OF LUBBOCK EXPECTED
TO DISSIPATE BEFORE REACHING KLBB AND KPVW. ATTENTION THEN SHIFTS
TO POTENTIAL FOR LOW CLOUDS WEDNESDAY MORNING. BETTER CHANCES
APPEAR TO BE AT KCDS BEHIND A WEAK COLD FRONT OR OUTFLOW BOUNDARY
THAT WILL BE PUSHED SOUTH THROUGH THE PANHANDLE LATER TONIGHT.
LOW LEVEL MOISTURE ADVECTION BEHIND THE RETREATING DRYLINE COULD
LEAD TO SOME FOG AND/OR STRATUS AT BOTH KLBB AND KPVW TOWARD 12Z
BUT SIGNAL NOT QUITE AS STRONG. WILL KEEP THOSE TAFS AS INHERITED
AND REEVALUATE WITH THE 06Z ISSUANCE.
&&
.PREV DISCUSSION... /ISSUED 344 PM CDT TUE APR 21 2015/
SHORT TERM...
SURFACE DEWPOINTS HAVE BEEN FAIRLY STAGNANT ACROSS THE FORECAST AREA
TODAY AS MODEST ADVECTION BALANCES MIXING. AT 3 PM...SATELLITE
IMAGERY SHOWED A DEVELOPING CUMULUS FIELD IN EASTERN NEW MEXICO
WHERE THE DEWPOINTS ARE MOSTLY IN THE 30S. MORE EXTENSIVE
DEVELOPMENT WAS ONGOING ACROSS THE SACRAMENTOS AND SANGRES OF NM.
THE HRRR HAS BEEN FAIRLY CONSISTENT WITH BRINGING SOME OF THIS
ACTIVITY EASTWARD ACROSS THE WESTERN AND CENTRAL SOUTH PLAINS LATE
THIS AFTERNOON AND EVENING...ALTHOUGH IT IS ABOUT THE ONLY MODEL TO
DO SO. FCST SOUNDINGS IN THESE AREAS INDICATE ANY STORMS THAT DO
DEVELOP WILL BE HIGH-BASED HAVE LITTLE CAPE TO WORK WITH...SO THEY
WILL ONLY BE CAPABLE OF SPOTTY RAIN AND STRONG WIND GUSTS. IF ANY
STORMS CAN SURVIVE FARTHER TO THE EAST THIS EVENING AND ENCOUNTER
THE DEEPER MOISTURE...IT IS NOT OUT OF THE QUESTION THAT A HAIL
THREAT COULD DEVELOP...BUT THIS APPEARS UNLIKELY AT THIS TIME.
TONIGHT...THE LOW LEVEL JET WILL BRING RICHER MOISTURE NWWD INTO
WEST TEXAS...WITH THE SURFACE DRYLINE RETREATING THROUGH MOST IF NOT
ALL OF THE CWA...PERHAPS HOLDING BACK ACROSS THE FAR SW TX
PANHANDLE. NAM FCST SNDGS SHOW FOG POTENTIAL ACROSS THE SOUTHERN AND
CENTRAL SOUTH PLAINS BY EARLY WED MORNING SO WE HAVE ADDED A PATCHY
MENTION IN THE GRIDS....SOME AREAS OF LOW STRATUS ARE POSSIBLE AS
WELL. MEANWHILE TO OUR NORTH ACROSS THE PANHANDLES...THEY WILL
LIKELY SEE SOME OVERNIGHT TSTM ACTIVITY COINCIDING WITH A SWD-MOVING
COLD FRONT. IT IS UNCERTAIN WHAT IMPACT STORM COLD POOLS MAY HAVE ON
THE PROGRESS OF THE FRONT...WHICH TENDS TO LOWER OUR CONFIDENCE ON
HOW THE FRONT/OUTFLOW BOUNDARY WILL BEHAVE ON WEDNESDAY. IN
GENERAL...WE EXPECT THE BOUNDARY TO SINK SOUTH THROUGH THE FAR SRN
PANHANDLE AND POSSIBLY INTO THE NORTHERN ROLLING PLAINS. BACK TO THE
WEST...THE DRYLINE SHOULD FORM UP AND MOVE EAST AS A SURFACE TROUGH
DEVELOPS FROM EASTERN NM INTO THE ROLLING PLAINS. ALTHOUGH WE HAVE
TO STRESS A LARGE UNCERTAINTY IN THE PARTICULARS...A TRIPLE-POINT
MAY DEVELOP SOMEWHERE FROM OUR CENTRAL TO SOUTHEAST COUNTIES. BACKED
FLOW AND HIGH SURFACE MOISTURE WILL BE POSSIBLE ACROSS AT LEAST OUR
NE ZONES. WITH A MID-LVL SHORTWAVE PASSING ACROSS THE AREA DURING
THE DAY...STRONG INSTABILITY AND DEEP SHEAR IS LIKELY TO DEVELOP
ALONG AND TO THE NORTH AND EAST OF THE TRIPLE-POINT. GUIDANCE
GENERALLY SHOWS A STRONG CONVECTIVE SIGNAL IN THIS AREA BY LATE
AFTERNOON...ALTHOUGH WITH A LOT OF SPREAD RECORDING THE AREA
POTENTIALLY IMPACTED. WHERE STORMS OCCUR...SEVERE WEATHER WILL BE A
STRONG POSSIBILITY...INCLUDING THE POSSIBILITY OF TORNADOES
DEPENDING THE ORIENTATION/EVOLUTION ON THE BOUNDARY/S/. FARTHER
WEST...WE HAVE TRIMMED POPS DOWN OUR NEAR THE STATE LINE BUT LEFT A
SLIGHT CHANCE GOING ACROSS MUCH OF THE SOUTH PLAINS IN CASE THE
DRYLINE IS FARTHER WEST THAN ANTICIPATED.
LONG TERM...
THE PATTERN THEME THROUGH EARLY NEXT WEEK REMAINS THAT OF A
PROGRESSIVE ONE AS A SERIES OF SOUTHERN STREAM TROUGHS IMPACT THE
REGION. ONLY UNTIL THEREAFTER DOES THE PATTERN SHOW SIGNS OF
TRENDING MORE STAGNANT IN THE FORM OF MID-CONUS LONGWAVE RIDGING.
ALL DAYS CONSIDERED...WEDNESDAY EVENING LOOKS TO GRAB THE LIMELIGHT
FOR SENSIBLE WEATHER AS A SEVERE CONVECTIVE EPISODE SHOULD BE WELL
UNDERWAY. LOCATION OF THIS EVENT WILL BE HIGHLY DEPENDENT ON A
STATIONARY FRONT CURRENTLY PROGGED TO BISECT OUR CWA FROM NW-SE BY
LATE EVENING...THOUGH MODELS CONTINUE TO FAVOR OUR NERN COUNTIES.
BACKGROUND FORCING APPEARS RATHER SUBDUED AND LINKED MOSTLY TO A
SHORTWAVE TROUGH CRESTING SHALLOW RIDGING ALOFT AND A NORTHWARD PUSH
OF STRONGER SUBTROPICAL WINDS. THIS ALONG WITH FAVORABLE DEEP SHEAR
MAY SERVE TO KEEP CONVECTIVE MODES RESTRICTED TO ISOLATED OR
SCATTERED SUPERCELLS. FEEL 40-50 PERCENT POPS WED EVENING ARE
REPRESENTATIVE OF THIS SCENARIO FOR NOW BEFORE PRECIP EVENTUALLY
MOVES DOWNSTREAM LATE WED NIGHT.
BEYOND WEDNESDAY NIGHT...THE WAVERING FRONTAL BOUNDARY SHOULD LIFT
NORTH AS A WARM FRONT IN ADVANCE OF A MORE ROBUST TROUGH LIFTING OUT
OF THE DESERT SOUTHWEST. THIS WAVE WILL PROJECT EVEN STRONGER WINDS
ATOP THE REGION PERHAPS ACCOMPANIED BY OCCASIONAL IMPULSES AND
SLIGHT CHANCE POPS...ESPECIALLY OFF THE CAPROCK WHERE LL MOISTURE
WILL HAVE A GREATER RESIDENCE TIME. MODEL CONSENSUS IS FOR DRY
SLOTTING TO SURGE ATOP THE CAPROCK COUNTIES BY EARLY FRIDAY AND
QUICKLY SWEEP EAST AS THE BASE OF THE TROUGH LIFTS TO OUR NORTH.
THE TIMING AND PATH OF THIS TROUGH SUGGEST A WINDY DAY IS IN STORE
YET WE REMAIN A BIT RELUCTANT TO BITE ON THE STRONG WINDS AS
PROGGED BY THE GFS AT TIMES. TIME-HEIGHT X-SECTIONS SHOW NEXT TO
NIL CIRRUS...SO WE MAY NEED TO RATCHET UP OUR 20-30 MPH WINDS
EVEN FURTHER IN LATER FORECASTS IF THIS THEME PERSISTS.
BY SATURDAY...QUIETER WEATHER UNDER TRANSIENT RIDGING WILL BE
REPLACED BY ONE FINAL TROUGH AT SOME POINT ON SUNDAY AHEAD OF
MODIFIED CANADIAN AIR WHICH LOOKS TO DIVE INTO THE GULF COME
MONDAY. PRECIP MERIT FROM SUN-SUN NIGHT DOESN/T SHOW MUCH
SUBSTANCE AMONG THE LATEST GLOBAL MODELS...SO POPS WERE SCALED
BACK IN COVERAGE TO BETTER MATCH THE DRIER SUPERBLEND AND
CONSENSUS ROUTES.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 47 80 48 79 / 20 20 10 0
TULIA 50 79 51 78 / 20 30 20 10
PLAINVIEW 50 81 52 78 / 20 20 20 10
LEVELLAND 51 83 51 80 / 20 10 10 0
LUBBOCK 54 83 52 80 / 20 20 10 10
DENVER CITY 53 83 53 80 / 20 10 0 0
BROWNFIELD 54 83 53 81 / 20 10 10 0
CHILDRESS 56 78 56 77 / 30 50 40 20
SPUR 57 82 59 81 / 20 20 20 20
ASPERMONT 60 84 61 82 / 20 20 20 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS AMARILLO TX
250 PM CDT MON APR 20 2015
.SHORT TERM... (TONIGHT)
THE SURFACE HIGH WILL CONTINUE TO SLIDE EAST ALLOWING FOR SOUTHERLY
FLOW TO BRING GULF MOISTURE INTO THE AREA AND BRINGING UPSLOPING
WINDS. THE UPPER LEVEL RIDGE OFF TO THE WEST IS ALSO MOVING
EASTWARD AND BRINGING A VORT LOBE THROUGH THE AREA. THESE TWO
LIFTING MECHANISMS WILL CREATE CHANCES FOR RAIN SHOWERS OVER THE
CENTRAL TO SOUTHERN TX PANHANDLE BETWEEN 6PM THROUGH 1AM. PREFERRED
THE GFS MODEL OVER NAM AS IT CAPTURED QPF LOCATIONS BETTER AS IT
AGREED WITH TEXAS TECH WRF AND HRRR MODELS. THUS WENT WITH MAV
GUIDANCE ON WINDS AND DEW POINTS. TONIGHT SHOULD BE WARMER THAN
LAST NIGHT DUE TO INCREASED CLOUD COVER AND THE SOUTHERLY FLOW
CREATING LOWS IN THE UPPER 30S TO MID 40S OVERNIGHT.
MB/CLK
.LONG TERM... (TOMORROW THROUGH SUNDAY)
THERE IS A VERY LOW PROBABILITY OF RESIDUAL CONVECTION IN THE FAR
EAST TOMORROW MORNING AS SUBTLE MID-LEVEL WAVE EXITS THE AREA. LATER
IN THE DAY WEAK HEIGHT FALLS OCCUR JUST TO OUR WEST AS CLOSED LOW IN
THE SOUTHWEST CONUS DEEPENS. ALTHOUGH SUBTLE (AND DESPITE STILL
RELATIVELY WEAK MEAN WESTERLY-NORTHWESTERLY FLOW) THIS SHOULD STILL
BE SUFFICIENT TO FORCE LEE SURFACE PRESSURE FALLS AND START THE
NORTHWESTWARD MOVEMENT OF LOW LEVEL MOISTURE BACK INTO THE AREA.
CURRENT SURFACE OBSERVATION SHOW OFF SHORE FLOW WITH RICH LOW LEVEL
MOISTURE LIMITED TO COASTAL AREAS AND DEEP SOUTH TEXAS. SHORT RANGE
GUIDANCE GENERALLY SHOWS THE EQUATORWARD PUSH OF THE COLD FRONT HAS
STOPPED AS SURFACE FLOW VEERING IN RESPONSE TO
STRENGTHENING/SOUTHEASTWARD MOVING SURFACE HIGH IN THE LOWER
MISSISSIPPI VALLEY. TIMING OF RELATIVELY RICH LOW-LEVEL MOISTURE IS
SOMEWHAT IN QUESTION GIVEN EVAPOTRANSPIRATIVE PARAMETRIZATION
POSSIBLY EXAGGERATING QUALITY OF MOISTURE RETURN INITIALLY. AM
CONCERNED THAT GOOD QUALITY MOISTURE RETURN MAY BE TOO RAPID THROUGH
LATE AFTERNOON/EARLY EVENING. SOME CONVECTION COULD FORM BY LATE
AFTERNOON BUT COVERAGE OF MEASURABLE PRECIPITATION SHOULD BE LIMITED
NECESSITATING ONLY SLIGHT CHANCE PROBABILITIES THROUGH EARLY EVENING.
0-2KM THETA-E VALUES TREND UPWARD NOTABLY AFTER DARK AND WITH
INCREASING LARGE SCALE FORCING PRECIPITATION PROBABILITIES SHOULD BE
MARKEDLY HIGHER DURING THE EVENING AND OVERNIGHT PERIOD...ESPECIALLY
ACROSS THE EASTERN PORTION OF THE FORECAST AREA. A COLD FRONT FORCED
BY A NORTHERN STREAM WAVE WILL REACH OUR AREA BY WEDNESDAY MORNING
WITH UNCERTAINTY INCREASING SOMEWHAT BY THIS TIME. THE BOUNDARY WILL
PROBABLY PROGRESS SLOWLY SOUTHWARD THROUGH THE AREA BY EVENING WITH
WEAK ISENTROPIC LIFT ATOP SHALLOW COOL LAYER RESULTING IN
CONVECTION. HAVE DIMINISHED PROBABILITIES OVERNIGHT AS MOIST UPGLIDE
OVER THE BOUNDARY WEAKENS AND MID LEVEL HEIGHTS RISE SOME.
CONFIDENCE IS A LITTLE HIGHER IN THE EXTENDED GIVEN BETTER AGREEMENT
OF MEDIUM RANGE DETERMINISTIC GUIDANCE AND LESS SPREAD IN THE
ENSEMBLE MEMBERS. BY THURSDAY A MUCH MORE SIGNIFICANT MID-UPPER
TROUGH IN THE SOUTHWEST APPROACHES CAUSING A FAIRLY DRAMATIC SURFACE
RESPONSE THROUGH FRIDAY. STRENGTHENING LEE TROUGH/LOW WILL RESULT IN
INCREASED LOW-LEVEL MOIST FLOW AGAIN AND WITH MIXING BY THURSDAY
AFTERNOON THE DRYLINE WILL SHARPEN ACROSS THE AREA. THE BEST
OPPORTUNITY FOR PRECIPITATION WITH THIS SYSTEM WILL BE THURSDAY
AFTERNOON AND EVENING AHEAD OF SHARPENING DRYLINE WHICH SEEMS MOST
LIKELY TO BE POSITIONED NORTH-SOUTH ACROSS THE CENTRAL PORTION OF
THE PANHANDLES.
GIVEN THE PROGRESSIVE NATURE OF THIS SYSTEM A PERIOD OF POST-DRYLINE
DEEP MIXING MAY OCCUR FRIDAY AFTERNOON WITH CONCERNS FOR FIRE WEATHER
POSSIBLY DEVELOPING THEN. BY THE WEEKEND IN THE WAKE OF THIS WAVE A
QUASI-ZONAL UPPER FLOW PATTERN EVOLVES WITH SOME FAIRLY SIZABLE
PERTURBATIONS SHOWING UP IN MEDIUM RANGE GUIDANCE...PARTICULARLY
AROUND SUNDAY. ALTHOUGH TIMING IS UNCERTAIN AT THIS POINT IN
TIME...DID MAINTAIN LOW PRECIPITATION PROBABILITIES ON SUNDAY.
BRB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
05/17
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
927 PM EDT TUE APR 21 2015
.SYNOPSIS...
HIGH PRESSURE WILL STAY SOUTH OF US TONIGHT WHILE A FRONT MOVES IN
FROM THE NORTHWEST. THIS FRONT WILL CROSS THE REGION WEDNESDAY AND
SHIFT OFFSHORE BY THURSDAY MORNING RESULTING IN BREEZY CONDITIONS
WEDNESDAY INTO THURSDAY AHEAD AND BEHIND THE FRONT. BY
FRIDAY...HIGH PRESSURE WILL BE SITUATED FROM THE WESTERN GREAT
LAKES...SOUTH INTO THE SOUTHERN APPALACHIANS.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 912 PM EDT TUESDAY...
EVENING SOUNDINGS AND SURFACE OBS SHOW VERY DRY AIR LINGERING OVER
THE REGION THIS EVENING AHEAD OF A WEAK TROUGH JUST WEST OF THE
MOUNTAINS AND THE NEXT COLD FRONT IN THE UPPER MIDWEST. INITIAL
BAND OF BROKEN CLOUDS NOW CROSSING THE OHIO RIVER MAY BRING A FEW
SPRINKLES TO THE WESTERN SLOPES BEFORE FADING AFTER MIDNIGHT GIVEN
DEEP WESTERLY FLOW AND A LINGERING WELL MIXED DRY LAYER JUST OFF
THE SURFACE. APPEARS NEXT ROUND OF POTENTIAL SHOWERS WONT ARRIVE
UNTIL WED MORNING AHEAD OF THE FRONT SO TRIMMING BACK WESTERN POPS
A BIT MORE OVERNIGHT SIMILAR TO THE LATEST HRRR TRENDS. OTRW
MOSTLY CLEAR TO INIT THEN BECOMING PARTLY TO MOSTLY CLOUDY AT
TIMES FAR WEST AND PC ELSW LATE. TEMPS TO ZOOM DOWN IN THE WESTERN
VALLEYS EARLY ON AS WINDS FADE WITH SOME SPOTS FALLING INTO THE
30S BEFORE BUMPING UP WITH CLOUDS LATER ON. LATEST LAV MOS SLOW TO
DROP VALUES BUT LIKELY TOO WARM EXCEPT ON THE RIDGES GIVEN SUCH
LOW DEWPOINTS THIS EVENING SO ONLY MAKING SLIGHT TWEAKS IN SPOTS.
PREVIOUS DISCUSSION AS OF 300 PM EDT TUESDAY...
VERY DRY AT THE MOMENT WITH FEW TO SCATTERED CU. UPSTREAM...SFC FRONT
WORKING INTO THE MIDWEST WILL BE OUR NEXT WEATHER MAKER...AND WIND
WILL BE THE MAIN CULPRIT.
THIS EVENING INTO THE OVERNIGHT THE SKIES WILL BE STAY CLEAR TO
PARTLY CLOUDY THEN SHOULD SEE MORE CLOUDS ARRIVE AFTER MIDNIGHT INTO
THE MTNS. SLOWED DOWN ONSET OF POPS GIVEN DRY LOW LVLS...THOUGH WILL
SEE A FEW SHOWERS MAKE IT TO GREENBRIER TO THE MTN EMPIRE AROUND
DAWN.
TEMPS WILL BE DROPPING QUICKER THIS EVENING ONCE THE WINDS SETTLE
DOWN SOME. ALOFT HOWEVER...WINDS SHOULD STAY UP KEEPING HIGHER
TERRAIN MIXED. KEEPING THE WRN SLOPES IN THE 40S FOR LOWS...WHILE
VALLEYS IN THE MTNS AND FOOTHILLS FALL INTO THE UPPER 30S. NOT
EXPECTING ANY FROST/FREEZE CONCERNS.
FOR WEDNESDAY....THE LOW LEVEL JET SETS UP FROM KENTUCKY TO MARYLAND
DURING THE MORNING/EARLY AFTERNOON. SFC FRONT WILL MAKE IT INTO THE
WV MTNS BY MIDDAY THEN SLOWLY DROP SE INTO THE PIEDMONT BY EVENING.
STABILITY SEEMS MARGINAL BUT WIND ENERGY WITH SHOWERS ARE A CONCERN
FOR GUSTY SHOWERS AND POSSIBLE THUNDERSTORMS. SPC HAS MARGINAL RISK
EAST OF ROANOKE TOWARD LYH/RIC...FOR DAMAGING WINDS. ATTM...WILL
HAVE GUSTY WIND WORDING IN THE THUNDERSTORMS FOR WED AFTERNOON.
THE WAA PATTERN AND WINDS ALOFT FAVOR SOME OF THE HIGHER RIDGES FROM
HSP TO BOONE TO GET CLOSE TO ADVISORY LEVELS OF 46 MPH FOR GUSTS.
OVERALL..THE WINDS WILL STAY BELOW THIS AS WE USUALLY NEED A 50-55
KT 8H JET AND THE MODELS KEEP THE BEST WINDS SITUATED NORTH OF US.
WEDNESDAY WILL NOT BE WASHOUT AND WSW FLOW AT TIMES SHOULD LIMIT
STORM/SHOWER DEVELOPMENT EAST OF THE MTNS...BUT ENOUGH BACKING
SHOULD ALLOW FOR OVERALL LOW LVL CONVERGENCE NOT TO KEEP IT
COMPLETELY DRY.
GOING TOWARD DUSK...THE SHOWERS WILL FADE IN COVERAGE. WEDNESDAY
WILL BE MILD/SEASONAL WITH HIGHS FROM THE UPPER 50S SE WV TO LOWER
TO MID 70 SOUTHEAST.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 230 PM EDT TUESDAY...
A WEAK COLD FRONT WILL SLIDE EAST OF THE AREA WEDNESDAY EVENING. ANY
LINGERING SHOWERS WILL DISSIPATE BY 10P WITH LOSE OF HEATING AND
INCREASE DRIER AIR ADVECTION. THE 12Z GFS IS IN AGREEMENT WITH THIS
SCENARIO...SO THE FORECAST IS MORE HEAVILY WEIGHTED TO THAT
SOLUTION. HIGH PRESSURE CONTINUES TO BUILD EAST INTO THE AREA
THURSDAY...HOWEVER A MODEST PRESSURE GRADIENT WILL KEEP BREEZY AND
GUSTY NORTHWEST WINDS OVER THE AREA THROUGH THE DAY. THE CENTER OF
THE HIGH DRIFTS OVER THE AREA THURSDAY NIGHT WITH CALMING WINDS AND
COOLER THAN NORMAL TEMPERATURES INTO THE DAY FRIDAY. TEMPERATURES
THURSDAY AND FRIDAY WILL RANGE FROM THE UPPER 50S TO LOWER 60S
ACROSS THE MOUNTAINS TO MID TO UPPER 60S EAST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 240 PM EDT TUESDAY...
A WARM FRONT WILL ENTER THE REGION FROM THE SOUTHWEST FRIDAY NIGHT
BRINGING AN INCREASE IN CLOUDS AND THE CHANCE FOR RAIN SATURDAY
MORNING. RAIN CHANCES INCREASE DURING SATURDAY AFTERNOON AS
ISENTROPIC LIFT INCREASES WITH WARM MOIST AIR OVERRUNNING COOLER
SURFACE AIR. A SURFACE WAVE IS EXPECTED TO TRACK OVER THE TENNESSEE
VALLEY SATURDAY...THEN ACROSS THE CAROLINAS SUNDAY. THIS WAVE WILL
CONTINUE THE CHANCE FOR RAIN IN THE AREA THROUGH SUNDAY
MORNING...THEN A BACK DOOR COLD FRONT BRINGS COOLER DRIER AIR INTO
THE REGION FOR SUNDAY AFTERNOON INTO MONDAY. A STRONGER SURFACE WAVE
TRACKS ACROSS THE TENNESSEE VALLEY TO THE CAROLINA MONDAY NIGHT INTO
TUESDAY. THIS WAVE WILL HAVE MORE MOISTURE AND DYNAMICS TO BRING
SOME HEAVY RAIN AND STRONG STORMS TO THE REGION. TEMPERATURES
THROUGH THE PERIOD WILL REMAIN COOLER THAN NORMAL WITH UPPER 50S TO
LOWER 60S ACROSS THE MOUNTAINS TO MID TO UPPER 60S EAST.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
AS OF 635 PM EDT TUESDAY...
A VFR MIX OF HIGH BASED CU AND AC WILL PREVAIL INTO THIS EVENING
WITH GUSTY WESTERLY WINDS SLOWLY DIMINISHING AFTER SUNSET. HOWEVER
GIVEN THE PRESSURE GRADIENT AHEAD OF THE NEXT UPSTREAM COLD
FRONT...ONLY EXPECTING THE VALLEY LOCATIONS SUCH AS KLWB/KBCB/KLYH
AND PERHAPS KDAN TO SEE WINDS BECOME LIGHT LATE WHILE LOCATIONS
SUCH AS KBLF/KROA LIKELY MAINTAIN A SW WIND AT 8-15 KTS THROUGH
MORNING. LOW LEVEL JET ALSO RAMPS UP AHEAD OF THE FRONT ESPCLY
ACROSS THE MOUNTAINS WHICH WOULD SUPPORT SOME SPOTS OF LOW LEVEL
WIND SHEAR LATE TONIGHT. THUS KEPT MENTION AT KLWB AND ADDED AT
KBCB TOWARD DAYBREAK WEDNESDAY WHILE LEAVING OUT ELSEWHERE FOR
NOW.
INCREASE IN CLOUDS LATE TONIGHT IN THE 5-10KFT RANGE WITH THE
PRE-FRONTAL BAND OF MOISTURE STARTING TO ENTER THE FAR WESTERN
MOUNTAINS. AS WE HEAD INTO WED MORNING THE FRONT WILL BE MAKING
ITS TRACK OVER THE RIDGES WITH SHOWERS INCREASING OVER SE WEST VA.
ATTM...WILL HAVE VFR TO HIGH END MVFR...BUT THE THREAT OF
MODERATE TO HEAVY SHOWERS AND EVEN A THUNDERSTORM ARRIVES TOWARD
THE END OF THE TAF PERIOD MAINLY MOUNTAINS. SINCE COVERAGE LOOKS
RATHER LIMITED OUTSIDE OF THE KBLF-KLWB CORRIDOR GIVEN DEEP/STRONG
MIXING...ONLY BROUGHT SHOWERS EAST INTO KBCB IN THE AFTERNOON
WITH A PERIOD OF MVFR VSBYS POSSIBLE AT KBLF/KLWB.
EXPECT STRONG WESTERLY WINDS AHEAD AND BEHIND THIS FRONT...WITH
POTENTIAL GUSTS OVER 30-35 KTS...ESPCLY MOUNTAINS...WITH EVEN
SOME GUSTS TO 30 KTS OR STRONGER IN THE EAST AROUND KDAN WED
AFTERNOON.
EXTENDED AVIATION...
FRONT WILL EXIT BY WEDNESDAY NIGHT WITH HIGH PRESSURE BUILDING INTO
THE REGION FROM THE WEST THU-FRI. SOME GRADIENT REMAINS BETWEEN
DEPARTING FRONT AND HIGH TO THE WEST THURSDAY AND POSSIBLY
FRIDAY...SO GUSTY WINDS WILL REMAIN MAINLY DURING THE DAYTIME.
OVERRUNNING CLOUDS WORK INTO THE AREA FRIDAY AHEAD OF A WARM
FRONT. BY SATURDAY...ENOUGH MOISTURE TO ALLOW FOR SHOWERS AND MVFR
WITH BEST FORCING ACROSS THE CAROLINAS. THIS WILL BE POSSIBLE
INTO SUNDAY MORNING BEFORE THE SYSTEM EXITS AND SOME IMPROVEMENT
IN CIGS STARTS TO OCCUR LATER SUNDAY.
&&
.FIRE WEATHER...
AS OF 330 PM EDT TUESDAY...
WET FUELS WILL DRY OUT AS WE HEAD INTO WEDNESDAY. A FRONT WILL
APPROACH WEDNESDAY WITH GOOD MIXING OUT AHEAD OF IT. GUSTY WINDS
IN THE 25 TO 35 MPH RANGE WILL OCCUR AT TIMES OVER THE PIEDMONT
WHERE MIN RH SINKS TO 30 PERCENT DURING THE AFTERNOON. AT THIS
TIME A FEW SHOWERS AND STORMS COULD BE OCCURRING SO FIRE DANGER
FOR NOW IS LOW TO MODERATE AS 1 AND 10 HOUR FUELS HAVE EITHER
GREENED UP OR ARE GREENING UP. ISSUES WOULD BE WITH ANY LOOSE LEAF
LITTER THAT CAN DRY OUT ENOUGH...THOUGH SOILS THEMSELVES STAY
MOIST.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...JH/WP
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...AMS/JH/WP
FIRE WEATHER...WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
214 PM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION THIS AFTERNOON INTO
TONIGHT AND BRING SHOWERS AND SOME STRONG THUNDERSTORMS TO THE
REGION. WE WILL THEN SETTLE INTO A COOLER...BREEZY...AND SOMEWHAT
UNSETTLED PATTERN THROUGH THE MIDDLE OF THE WORKWEEK...WITH THE
BEST CHANCE OF MORE SHOWERS AND THUNDERSTORMS ARRIVING WITH
ANOTHER FRONT ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1024 AM EDT MONDAY...
ACTIVE WEATHER DAY WITH LINGERING FLOODING ISSUES FROM SUNDAY TO
SUNDAY NIGHT HEAVY RAINS AND A SEVERE WEATHER THREAT FOR THIS
AFTERNOON INTO TONIGHT WITH COLD FRONT. SWODY1 HAS ADDED AN
ENHANCED POTENTIAL (30 PERCENT) TO SLIGHT RISK WHICH COVERS MUCH
OF OUR FORECAST AREA TODAY. THE MAIN THREATS FOR THUNDERSTORMS
PRODUCING DAMAGING WINDS AND LARGE HAIL...ALONG WITH LOCALLY HEAVY
RAIN. MODIFIED MORNING 12Z RNK SOUNDING SUPPORTS CONCERNS WITH
MODIFIED CAPES AROUND 1000 TO 2000 J/KG WITH HEALTHY SHEAR AROUND
40 KNOTS. ADJUSTED TIMING OF POPS CLOSER TO A BLEND OF HRRR AND
WRFRNK-ARW. MODIFIED TEMPERATURES AND DEW POINTS WITH SFC OBS AND
MODEL TRENDS. COLD FRONT PUSHES EAST ACROSS REGION THIS AFTERNOON
INTO THIS EVENING...THEN HIGH PRESSURE BUILDS IN BEHIND FRONT
TUESDAY. MORE CHANGES THIS AFTERNOON...
AS OF 525 AM EDT MONDAY...
THERE ARE LINGERING HYDRO ISSUES EARLY THIS MORNING FOLLOWING THE
WIDESPREAD HEAVY RAIN FROM SUNDAY AND SUNDAY NIGHT...AND SEVERAL
FLOOD WARNINGS REMAIN IN EFFECT FROM THE NORTH CAROLINA MOUNTAINS
THROUGH THE GRAYSON HIGHLANDS AND INTO SOUTHWEST VIRGINIA UNTIL
AROUND 9AM. THE SITUATION WILL CONTINUED TO BE MONITORED WITH
ADJUSTMENTS MADE ACCORDINGLY.
THE NEXT CONCERN IS THE APPROACHING COLD FRONT SET TO CROSS THE
AREA THIS AFTERNOON. MESO MODELS DISSIPATE THE CONVECTIVE COMPLEX
CURRENTLY APPROACHING FROM THE WEST WITH REDEVELOPMENT FIRING
LATER THIS MORNING INTO THIS AFTERNOON ACROSS THE REGION...
ESPECIALLY FRONT HE BLUE RIDGE EAST. EARLY MORNING SATELLITE PICS
SHOW BREAKS IN THE CLOUD COVER AND WITH 850MB TEMPS AROUND 12C WE
SHOULD SEE SURFACE TEMPERATURES RISE WELL INTO THE 70S TODAY. THIS
WILL GENERATE CAPE VALUES OF 1000J/KG TO 1500J/KG WHICH WILL BE
ENOUGH TO SUPPORT VIGOROUS CONVECTION. LOW LEVEL WINDS WILL GIVE
US 0/6KM BULK SHEAR VALUES OF 40KTS TO 50KTS WITH A SOMEWHAT
LINEAR HODOGRAPH. THUS THERE IS ENOUGH INSTABILITY AND SHEAR
PRESENT FOR A SEVERE THREAT...AND THE SPC SLIGHT RISK LOOKS TO BE
ON TARGET. WILL BE ANTICIPATING STORM CLUSTERS EVOLVING INTO
LINEAR ELEMENTS TO PRODUCE A WIND THREAT...AND THE MORE VIGOROUS
CELLS SHOULD HAVE ENOUGH CAPE IN THE HAIL GROWTH ZONE TO SUPPORT
LARGE HAIL POTENTIAL AS WELL. WHILE SWATS REMAIN HIGH BELIEVE ANY
HEAVY RAIN WILL BE LOCALIZED AND FURTHER EAST WHICH SHOULD HELP
AVOID AGGRAVATING THE HYDRO SITUATION. ENOUGH INGREDIENTS FOR A BUSY
AFTERNOON ON RADAR.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 214 PM EDT MONDAY...
UPPER TROUGH WILL BE SITUATED RIGHT OVER THE AREA TUESDAY NIGHT WITH
NEXT SFC FRONT WORKING ACROSS BY WEDNESDAY...THOUGH WITH MORE WNW
FLOW ALOFT AND LACK OF SOUTHERLY INFLOW AHEAD OF THIS
SYSTEM...MOISTURE WILL BE LIMITED. AS SUCH HAVE LIMITED CHANCE POPS
OVER THE MOUNTAINS WITH SOME CHANCE INTO THE NE PIEDMONT OF
VA...WITH LESS COVERAGE INTO THE NC PIEDMONT...AS WE SHOULD SEE SOME
DOWNSLOPE DRYING AND SHEARING OF THE VERTICAL DEVELOPMENT. JUST
ENOUGH INSTABILITY WITH COLDER AIR ALOFT TO MENTION THUNDER IN THE
AFTERNOON WEDNESDAY. SHOULD BE A BREEZY DAY WITH HIGHS FROM THE
UPPER 50S OVER SE WV TO LOWER 70S SOUTHEAST.
WEDNESDAY NIGHT THROUGH THURSDAY WILL BE MAINLY DRY WITH CONTINUED
UPPER TROUGH SLIDING ACROSS THE AREA...BUT AXIS SHIFTING MORE OVER
THE COAST. NW FLOW MAY KEEP SHOWERS GOING INTO THE MOUNTAINS WED
EVENING. UPPER RIDGING ARRIVES OVER THE LOWER MS VALLEY WITH SFC
HIGH IN THE TN VALLEY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 130 PM EDT MONDAY...
NOT MUCH CHANGE TO THIS FORECAST. HIGH PRESSURE AT THE SFC BUILDS
SOUTHEAST FROM THE OHIO VALLEY INTO FRIDAY. A SOUTHERN STREAM LOW
ARRIVES OVER THE AR/OK BORDER BY SATURDAY MORNING WITH OVERRUNNING
CLOUDS WORKING INTO THE AREA FRIDAY AHEAD OF A WARM FRONT. BY
SATURDAY ENOUGH MOISTURE TO ALLOW FOR SHOWERS TO FORM BY SATURDAY
MORNING WITH BEST FORCING ACROSS THE CAROLINAS. THIS SYSTEM EXITS BY
SAT NIGHT WITH SUNDAY BEING A DRY AND COOL/MILD DAY WITH HIGHS IN
THE 50S MOUNTAINS TO 60S EAST. HIGH PRESSURE TO ASSUME POSITION OVER
THE OHIO VALLEY INTO THE SRN APPALACHIANS MONDAY TO KEEP THINGS DRY.
NEXT SOUTHERN STREAM SYSTEM MAY WORK SOME SHOWERS OUR WAY BY TUESDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 140 PM EDT MONDAY...
VFR CONDITIONS WILL LOWER THIS AFTERNOON INTO TONIGHT IN
CONVECTION TO MVFR AND IFR AHEAD AND ALONG A COLD FRONT.
SHOWERS AND THUNDERSTORMS WILL DEVELOP QUICKLY WITH THE COLD FRONT
AS IT MOVES EAST ACROSS THE REGION AND EXITS THIS EVENING.
THERE IS SLIGHT TO ENHANCED RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON INTO TONIGHT ESPECIALLY EAST OF THE BLUE RIDGE
MOUNTAINS. ISOLATED GUSTS AROUND 50 KNOT MAY BE POSSIBLE WITH ANY
SEVERE THUNDERSTORM.
PRESSURE RISES BEHIND THE FRONT WILL BRING BREEZY AND GUSTY
WESTERLY WINDS TO THE AREA THIS EVENING INTO TONIGHT. ALSO
THIS EVENING INTO TONIGHT BEHIND THE FRONT...SOME MVFR CEILINGS
ARE POSSIBLE IN THE MOUNTAINS. UNCERTAINTY ON HOW LOW CEILINGS
WILL GET ONCE THE SHOWERS CLEAR OUT TONIGHT. ANOTHER ISSUE IS THAT
ANY LOCATION THAT RECEIVED OVER AN INCH OF RAIN MAY SEE FOG
DEVELOPING OVERNIGHT INTO TUESDAY. VFR CONDITIONS SHOULD RETURN
LATER TONIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING IN BEHIND
THE FRONT WITH A DRIER AIRMASS.
EXTENDED AVIATION...
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY. HIGH PRESSURE
AT THE SURFACE BUILDS SOUTHEAST FROM THE OHIO VALLEY THURSDAY
NIGHT INTO FRIDAY. OVERRUNNING CLOUDS WORKING INTO THE AREA
FRIDAY AHEAD OF A WARM FRONT. BY SATURDAY...ENOUGH MOISTURE TO
ALLOW FOR SHOWERS TO FORM BY SATURDAY MORNING WITH BEST FORCING
ACROSS THE CAROLINAS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...MBS
NEAR TERM...KK/MBS
SHORT TERM...WP
LONG TERM...WP
AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
156 PM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION THIS AFTERNOON INTO
TONIGHT AND BRING SHOWERS AND SOME STRONG THUNDERSTORMS TO THE
REGION. WE WILL THEN SETTLE INTO A COOLER...BREEZY...AND SOMEWHAT
UNSETTLED PATTERN THROUGH THE MIDDLE OF THE WORKWEEK...WITH THE
BEST CHANCE OF MORE SHOWERS AND THUNDERSTORMS ARRIVING WITH
ANOTHER FRONT ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1024 AM EDT MONDAY...
ACTIVE WEATHER DAY WITH LINGERING FLOODING ISSUES FROM SUNDAY TO
SUNDAY NIGHT HEAVY RAINS AND A SEVERE WEATHER THREAT FOR THIS
AFTERNOON INTO TONIGHT WITH COLD FRONT. SWODY1 HAS ADDED AN
ENHANCED POTENTIAL (30 PERCENT) TO SLIGHT RISK WHICH COVERS MUCH
OF OUR FORECAST AREA TODAY. THE MAIN THREATS FOR THUNDERSTORMS
PRODUCING DAMAGING WINDS AND LARGE HAIL...ALONG WITH LOCALLY HEAVY
RAIN. MODIFIED MORNING 12Z RNK SOUNDING SUPPORTS CONCERNS WITH
MODIFIED CAPES AROUND 1000 TO 2000 J/KG WITH HEALTHY SHEAR AROUND
40 KNOTS. ADJUSTED TIMING OF POPS CLOSER TO A BLEND OF HRRR AND
WRFRNK-ARW. MODIFIED TEMPERATURES AND DEW POINTS WITH SFC OBS AND
MODEL TRENDS. COLD FRONT PUSHES EAST ACROSS REGION THIS AFTERNOON
INTO THIS EVENING...THEN HIGH PRESSURE BUILDS IN BEHIND FRONT
TUESDAY. MORE CHANGES THIS AFTERNOON...
AS OF 525 AM EDT MONDAY...
THERE ARE LINGERING HYDRO ISSUES EARLY THIS MORNING FOLLOWING THE
WIDESPREAD HEAVY RAIN FROM SUNDAY AND SUNDAY NIGHT...AND SEVERAL
FLOOD WARNINGS REMAIN IN EFFECT FROM THE NORTH CAROLINA MOUNTAINS
THROUGH THE GRAYSON HIGHLANDS AND INTO SOUTHWEST VIRGINIA UNTIL
AROUND 9AM. THE SITUATION WILL CONTINUED TO BE MONITORED WITH
ADJUSTMENTS MADE ACCORDINGLY.
THE NEXT CONCERN IS THE APPROACHING COLD FRONT SET TO CROSS THE
AREA THIS AFTERNOON. MESO MODELS DISSIPATE THE CONVECTIVE COMPLEX
CURRENTLY APPROACHING FROM THE WEST WITH REDEVELOPMENT FIRING
LATER THIS MORNING INTO THIS AFTERNOON ACROSS THE REGION...
ESPECIALLY FRONT HE BLUE RIDGE EAST. EARLY MORNING SATELLITE PICS
SHOW BREAKS IN THE CLOUD COVER AND WITH 850MB TEMPS AROUND 12C WE
SHOULD SEE SURFACE TEMPERATURES RISE WELL INTO THE 70S TODAY. THIS
WILL GENERATE CAPE VALUES OF 1000J/KG TO 1500J/KG WHICH WILL BE
ENOUGH TO SUPPORT VIGOROUS CONVECTION. LOW LEVEL WINDS WILL GIVE
US 0/6KM BULK SHEAR VALUES OF 40KTS TO 50KTS WITH A SOMEWHAT
LINEAR HODOGRAPH. THUS THERE IS ENOUGH INSTABILITY AND SHEAR
PRESENT FOR A SEVERE THREAT...AND THE SPC SLIGHT RISK LOOKS TO BE
ON TARGET. WILL BE ANTICIPATING STORM CLUSTERS EVOLVING INTO
LINEAR ELEMENTS TO PRODUCE A WIND THREAT...AND THE MORE VIGOROUS
CELLS SHOULD HAVE ENOUGH CAPE IN THE HAIL GROWTH ZONE TO SUPPORT
LARGE HAIL POTENTIAL AS WELL. WHILE SWATS REMAIN HIGH BELIEVE ANY
HEAVY RAIN WILL BE LOCALIZED AND FURTHER EAST WHICH SHOULD HELP
AVOID AGGRAVATING THE HYDRO SITUATION. ENOUGH INGREDIENTS FOR A BUSY
AFTERNOON ON RADAR.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 525 AM EDT MONDAY...
BEHIND THE FRONT WE START TO SETTLE INTO A COOLER...BREEZY...AND
SOMEWHAT UNSETTLED PATTERN AS A BROAD CLOSED LOW TAKES UP
RESIDENCE OVER THE GREAT LAKES. THE FRONT WILL PUSH OFF TO OUR
EAST EARLY TONIGHT AND TAKE THE SHOWERS AND THUNDERSTORMS WITH
IT...LEAVING SOME UPSLOPE SHOWERS ACROSS THE FAR WEST FOR THE
OVERNIGHT. ANY LINGERING PRECIPITATION WILL DISSIPATE EARLY
TUESDAY MORNING AND TUESDAY LOOKS TO BE MOSTLY DRY. COULD SEE THE
OUTSIDE POSSIBILITY OF COOKING UP SOME SHOWERS ON TUESDAY
AFTERNOON BUT BELIEVE THE POPS ARE TOO SMALL TO MENTION SO WILL
KEEP THINGS UNDER 15 PERCENT. ANOTHER FRONT WILL ROTATE THROUGH
THE REGION ON WEDNESDAY AND WILL HAVE SOME SLIGHT INSTABILITY AND
STEEP LAPSE RATES TO WARRANT A MENTION OF THUNDER. WEAK HIGH
PRESSURE WILL THEN BUILD IN WEDNESDAY NIGHT AND BRING WHAT LOOKS
TO BE MOSTLY DRY WEATHER FOR THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
BROAD UPPER TROUGH REMAINS IN PLACE AND DOMINATES THE EXTENDED
FORECAST...GRADUALLY SHIFTING FURTHER ESE LATE IN THE PERIOD.
THIS KEEPS THE REGION IN AN UNSTABLE/UNSETTLED NORTHWEST FLOW WITH
NUMEROUS EMBEDDED SHORT WAVES. MODELS VARY CONSIDERABLY AS TO THE
TIMING AND PLACEMENT OF THESE DISTURBANCES...BUT ENOUGH AGREEMENT
THAT POPS CANNOT BE DROPPED REALLY AT ANY TIME THE OVERALL TREND
IS TO PUSH THE BETTER MOISTURE FURTHER SOUTH OF THE REGION AS THE
WEEK PROGRESSES AND 850MB TEMPS DROP BELOW 0C IN THE NORTHERN
COUNTIES. THE ENTIRE PERIOD SHOULD FEATURE BELOW NORMAL
TEMPERATURES WITH LOW CHC POPS...HIGHEST ACROSS THE MOUNTAINS AND
TOWARD THE SOUTHERN COUNTIES...WITH THE NORTHERN PIEDMONT THE
DRIEST. ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL THROUGHOUT THE
PERIOD...NO REAL CLEAR CONCERN AT THIS POINT FOR FROST/FREEZE
BECAUSE OF CYCLONIC FLOW AND CLOUDS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 140 PM EDT MONDAY...
VFR CONDITIONS WILL LOWER THIS AFTERNOON INTO TONIGHT IN
CONVECTION TO MVFR AND IFR AHEAD AND ALONG A COLD FRONT.
SHOWERS AND THUNDERSTORMS WILL DEVELOP QUICKLY WITH THE COLD FRONT
AS IT MOVES EAST ACROSS THE REGION AND EXITS THIS EVENING.
THERE IS SLIGHT TO ENHANCED RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON INTO TONIGHT ESPECIALLY EAST OF THE BLUE RIDGE
MOUNTAINS. ISOLATED GUSTS AROUND 50 KNOT MAY BE POSSIBLE WITH ANY
SEVERE THUNDERSTORM.
PRESSURE RISES BEHIND THE FRONT WILL BRING BREEZY AND GUSTY
WESTERLY WINDS TO THE AREA THIS EVENING INTO TONIGHT. ALSO
THIS EVENING INTO TONIGHT BEHIND THE FRONT...SOME MVFR CEILINGS
ARE POSSIBLE IN THE MOUNTAINS. UNCERTAINITY ON HOW LOW CEILINGS
WILL GET ONCE THE SHOWERS CLEAR OUT TONIGHT. ANOTHER ISSUE IS
THAT ANY LOCATION THAT RECIEVED OVER AN INCH OF RAIN MAY SEE
FOG DEVELOPING OVERNIGHT INTO TUESDAY. VFR CONDITIONS SHOULD
RETURN LATER TONIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING IN
BEHIND THE FRONT WITH A DRIER AIRMASS.
EXTENDED AVIATION...
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...MBS
NEAR TERM...KK/MBS
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1025 AM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION TODAY AND BRING SHOWERS
AND SOME STRONG THUNDERSTORMS TO THE REGION. WE WILL THEN SETTLE
INTO A COOLER...BREEZY...AND SOMEWHAT UNSETTLED PATTERN THROUGH
THE MIDDLE OF THE WORKWEEK...WITH THE BEST CHANCE OF MORE SHOWERS
AND THUNDERSTORMS ARRIVING WITH ANOTHER FRONT ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1024 AM EDT MONDAY...
ACTIVE WEATHER DAY WITH LINGERING FLOODING ISSUES FROM SUNDAY TO
SUNDAY NIGHT HEAVY RAINS AND A SEVERE WEATHER THREAT FOR THIS
AFTERNOON INTO TONIGHT WITH COLD FRONT. SWODY1 HAS ADDED AN
ENHANCED POTENTIAL (30 PERCENT) TO SLIGHT RISK WHICH COVERS MUCH
OF OUR FORECAST AREA TODAY. THE MAIN THREATS FOR THUNDERSTORMS
PRODUCING DAMAGING WINDS AND LARGE HAIL...ALONG WITH LOCALLY HEAVY
RAIN. MODIFIED MORNING 12Z RNK SOUNDING SUPPORTS CONCERNS WITH
MODIFIED CAPES AROUND 1000 TO 2000 J/KG WITH HEALTHY SHEAR AROUND
40 KNOTS. ADJUSTED TIMING OF POPS CLOSER TO A BLEND OF HRRR AND
WRFRNK-ARW. MODIFIED TEMPERATURES AND DEW POINTS WITH SFC OBS AND
MODEL TRENDS. COLD FRONT PUSHES EAST ACROSS REGION THIS AFTERNOON
INTO THIS EVENING...THEN HIGH PRESSURE BUILDS IN BEHIND FRONT
TUESDAY. MORE CHANGES THIS AFTERNOON...
AS OF 525 AM EDT MONDAY...
THERE ARE LINGERING HYDRO ISSUES EARLY THIS MORNING FOLLOWING THE
WIDESPREAD HEAVY RAIN FROM SUNDAY AND SUNDAY NIGHT...AND SEVERAL
FLOOD WARNINGS REMAIN IN EFFECT FROM THE NORTH CAROLINA MOUNTAINS
THROUGH THE GRAYSON HIGHLANDS AND INTO SOUTHWEST VIRGINIA UNTIL
AROUND 9AM. THE SITUATION WILL CONTINUED TO BE MONITORED WITH
ADJUSTMENTS MADE ACCORDINGLY.
THE NEXT CONCERN IS THE APPROACHING COLD FRONT SET TO CROSS THE
AREA THIS AFTERNOON. MESO MODELS DISSIPATE THE CONVECTIVE COMPLEX
CURRENTLY APPROACHING FROM THE WEST WITH REDEVELOPMENT FIRING
LATER THIS MORNING INTO THIS AFTERNOON ACROSS THE REGION...
ESPECIALLY FRONT HE BLUE RIDGE EAST. EARLY MORNING SATELLITE PICS
SHOW BREAKS IN THE CLOUD COVER AND WITH 850MB TEMPS AROUND 12C WE
SHOULD SEE SURFACE TEMPERATURES RISE WELL INTO THE 70S TODAY. THIS
WILL GENERATE CAPE VALUES OF 1000J/KG TO 1500J/KG WHICH WILL BE
ENOUGH TO SUPPORT VIGOROUS CONVECTION. LOW LEVEL WINDS WILL GIVE
US 0/6KM BULK SHEAR VALUES OF 40KTS TO 50KTS WITH A SOMEWHAT
LINEAR HODOGRAPH. THUS THERE IS ENOUGH INSTABILITY AND SHEAR
PRESENT FOR A SEVERE THREAT...AND THE SPC SLIGHT RISK LOOKS TO BE
ON TARGET. WILL BE ANTICIPATING STORM CLUSTERS EVOLVING INTO
LINEAR ELEMENTS TO PRODUCE A WIND THREAT...AND THE MORE VIGOROUS
CELLS SHOULD HAVE ENOUGH CAPE IN THE HAIL GROWTH ZONE TO SUPPORT
LARGE HAIL POTENTIAL AS WELL. WHILE SWATS REMAIN HIGH BELIEVE ANY
HEAVY RAIN WILL BE LOCALIZED AND FURTHER EAST WHICH SHOULD HELP
AVOID AGGRAVATING THE HYDRO SITUATION. ENOUGH INGREDIENTS FOR A BUSY
AFTERNOON ON RADAR.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 525 AM EDT MONDAY...
BEHIND THE FRONT WE START TO SETTLE INTO A COOLER...BREEZY...AND
SOMEWHAT UNSETTLED PATTERN AS A BROAD CLOSED LOW TAKES UP
RESIDENCE OVER THE GREAT LAKES. THE FRONT WILL PUSH OFF TO OUR
EAST EARLY TONIGHT AND TAKE THE SHOWERS AND THUNDERSTORMS WITH
IT...LEAVING SOME UPSLOPE SHOWERS ACROSS THE FAR WEST FOR THE
OVERNIGHT. ANY LINGERING PRECIPITATION WILL DISSIPATE EARLY
TUESDAY MORNING AND TUESDAY LOOKS TO BE MOSTLY DRY. COULD SEE THE
OUTSIDE POSSIBILITY OF COOKING UP SOME SHOWERS ON TUESDAY
AFTERNOON BUT BELIEVE THE POPS ARE TOO SMALL TO MENTION SO WILL
KEEP THINGS UNDER 15 PERCENT. ANOTHER FRONT WILL ROTATE THROUGH
THE REGION ON WEDNESDAY AND WILL HAVE SOME SLIGHT INSTABILITY AND
STEEP LAPSE RATES TO WARRANT A MENTION OF THUNDER. WEAK HIGH
PRESSURE WILL THEN BUILD IN WEDNESDAY NIGHT AND BRING WHAT LOOKS
TO BE MOSTLY DRY WEATHER FOR THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
BROAD UPPER TROUGH REMAINS IN PLACE AND DOMINATES THE EXTENDED
FORECAST...GRADUALLY SHIFTING FURTHER ESE LATE IN THE PERIOD.
THIS KEEPS THE REGION IN AN UNSTABLE/UNSETTLED NORTHWEST FLOW WITH
NUMEROUS EMBEDDED SHORT WAVES. MODELS VARY CONSIDERABLY AS TO THE
TIMING AND PLACEMENT OF THESE DISTURBANCES...BUT ENOUGH AGREEMENT
THAT POPS CANNOT BE DROPPED REALLY AT ANY TIME THE OVERALL TREND
IS TO PUSH THE BETTER MOISTURE FURTHER SOUTH OF THE REGION AS THE
WEEK PROGRESSES AND 850MB TEMPS DROP BELOW 0C IN THE NORTHERN
COUNTIES. THE ENTIRE PERIOD SHOULD FEATURE BELOW NORMAL
TEMPERATURES WITH LOW CHC POPS...HIGHEST ACROSS THE MOUNTAINS AND
TOWARD THE SOUTHERN COUNTIES...WITH THE NORTHERN PIEDMONT THE
DRIEST. ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL THROUGHOUT THE
PERIOD...NO REAL CLEAR CONCERN AT THIS POINT FOR FROST/FREEZE
BECAUSE OF CYCLONIC FLOW AND CLOUDS.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 750 AM EDT MONDAY...
CLUSTER OF SHOWERS AND THUNDERSTORMS IN THE TENNESSEE VALLEY WILL
MOVE EAST INTO VIRGINIA AND SOUTHERN WEST VIRGINIA THIS MORNING.
BASED ON CURRENT RADAR TRENDS THIS PRECIPITATION WILL REACH KBLF
BEFORE 16Z.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE REGION
THIS AFTERNOON AHEAD OF A COLD FRONT. PRESSURE RISES BEHIND THE
FRONT WILL BRING BREEZY AND GUSTY WESTERLY WINDS TO THE AREA INTO
MONDAY NIGHT. THERE IS SLIGHT RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON EAST OF THE BLUE RIDGE...SO WIND GUSTS WITH ANY SEVERE
THUNDERSTORMS AT KLYH AND KDAN MAY APPROACH 50 KNOTS. DO NOT
EXPECT TO HAVE ANYTHING THAT INTENSE THAT FAR EAST UNTIL AFTER
18Z.
IN THE EVENING BEHIND THE FRONT...MODELS WERE INDICATING SOME MVFR
CEILINGS IN THE MOUNTAINS. ONLY MODERATE CONFIDENCE HOW LOW
CEILINGS WILL GET ONCE THE SHOWERS CLEAR OUT AFTER SUNSET.
EXTENDED AVIATION...
VFR RETURNS LATER TONIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING
IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...MBS
NEAR TERM...KK/MBS
SHORT TERM...MBS
LONG TERM...RAB
AVIATION...AMS/RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
110 AM EDT MON APR 20 2015
.SYNOPSIS...
LOW PRESSURE OVER WESTERN KENTUCKY WITH A WARM FRONT EXTENDING EAST
AND COLD FRONT TRAILING SOUTHWARD FROM THE LOW WILL LIFT NORTHEAST
TONIGHT INTO MONDAY. A COLD FRONT CROSSES THE REGION ON
MONDAY...THEN HIGH PRESSURE BUILDS IN FOR TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 100 AM EDT MONDAY...
HEAVY RAIN HAS MOVED NORTH OF THE AREA...THEREFORE THE FLOOD WATCH
HAS BEEN CANCELLED FOR THE ENTIRE AREA.
PREVIOUS DISCUSSION...
AS OF 333 PM EDT SUNDAY...
A WARM FRONT TO OUR SOUTH WILL LIFT NORTH THIS EVENING AND CROSS THE
FORECAST AREA TONIGHT. DEEPER MOISTURE AND HIGHER PWATS WILL
INCREASE IN THE WARM ADVECTION WITH THE NORTHWARD ADVANCE OF THE
FRONT. THE REGIONAL RADAR IMAGE SHOWED WIDESPREAD CONVECTION ACROSS
THE MID ATLANTIC REGION SOUTHWARD TO THE SOUTHEAST US. THERE ARE
SOME CONCERNS OF STRONG CONVECTION ACROSS GEORGIA THIS AFTERNOON MAY
TAKE SOME OF THE MOISTURE AWAY FROM OUR AREA. OUR LOCAL RNK
WRFARW...HIRESW-ARW...NAM AND GFS WAIT UNTIL AFTER 00Z BEFORE
BRINGING IN HEAVIER CONVECTION THIS EVENING...WHILE HRRR AND ECMWF
ARE A LITTLE FASTER WITH TIMING. THE HRRR AND HIRESW-ARW LIFTS THE
PRECIPITATION NORTHEAST WITH MOST OF RAIN PULLING OUT BY 06-08Z.
USED A BLEND OF HRRR AND NAM FOR POPS...TAPERING POPS BACK AFTER 06Z
TONIGHT INTO MONDAY MORNING.
NOT EXPECTING ANY STRONG THUNDERSTORMS THIS AFTERNOON INTO TONIGHT
WITH CLOUD COVER HINDERING INSTABILITIES. HOWEVER...THE LOW LEVEL
JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL RESULT IN
STRONG UPSLOPE AND ISENTROPIC LIFT. THE STRONG WINDS THROUGH A
DEEP LAYER WILL PROVIDE LARGE HELICITY VALUES LATE THIS AFTERNOON
INTO THIS EVENING. THE DAY ONE CONVECTIVE OUTLOOK (SWODY1) PLACED
A MARGINAL (5 PERCENT CHANCE OF WIND) ACROSS SOUTHWEST PORTION OF
CWA. PLAYED LOW TEMPERATURES CLOSE TO ADJMAV WITH READINGS FROM
THE UPPER 40S IN THE NORTHWEST MOUNTAINS TO AROUND 60 DEGREES IN
THE PIEDMONT.
A WARM...MOIST AND UNSTABLE AIRMASS EXPECTED MONDAY. THE ATMOSPHERE
WILL DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT WITH SHOWERS
AND THUNDERSTORMS DEVELOPING MONDAY. INITIALLY CUT BACK POPS CLOSER
TO NAM FOR MONDAY MORNING...THEN INCREASED TO LIKELY BY MONDAY
AFTERNOON. SPC CONTINUES OUR SLIGHT RISK FOR MONDAY ACROSS MOST OF
OUR CWA. THIS IS SUPPORTED BY THE DYNAMIC ENVIRONMENT WITH HEALTHY
SHEAR AND DECENT CAPES AROUND 2K. IT WILL ALSO BE QUITE BREEZY WITH
EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER.
THE FRONT SHOULD BE CLEARING MONDAY NIGHT. HIGH TEMPERATURES MONDAY
WILL RANGE FROM THE MID 60S IN THE MOUNTAINS TO THE LOWER 80S IN THE
PIEDMONT.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
AS OF 345 PM EDT SUNDAY...
TAIL END OF COLD FRONT AND ASSOCIATED CONVECTION WILL BE EXITING
THE AREA JUST AFT 00Z. HOWEVER...A BROAD UPPER TROUGH...ALMOST
WINTERLIKE PATTERN CONTINUES TO EVOLVE AND DEEPEN ACROSS THE
GREAT LAKES WITH NUMEROUS SPOKES OF PVA/SHORT WAVES REMAINING
UPSTREAM. THIS LEAVES THE REGION...ESPECIALLY THE MOUNTAINS...WITH
A VERY UNSETTLED PATTERN. AT A MINIMUM...EXPECT VARIABLE
CLOUDINESS. TIMING OF EMBEDDED DISTURBANCES WILL BE THE KEY TO THE
TIMES FOR THE BETTER CHANCES OF SHOWERS. FOR SEVERAL DAYS...THE
GFS HAS INSISTED ON A SIGNIFICANT DISTURBANCE MOVING THROUGH THE
REGION WED WITH WIDESPREAD -SHRA AS A RESULT. THE OTHER MODELS
REMAIN LACKLUSTER WITH THIS FEATURE...BUT DO SUGGEST AT LEAST SOME
SMALL CHANCE WITHIN THIS TIME FRAME. GIVEN THE UNSETTLED NATURE OF
THE PATTERN WITH UPSLOPE FLOW AND VERY DIFFICULT TO TIME UPPER
DISTURBANCES...CANNOT REALLY DROP POPS AT ANY TIME. BEST FOCUS
THROUGH THE PERIOD WILL REMAIN WEST OF THE BLUE RIDGE...AND
ESPECIALLY ACROSS THE MOUNTAINS OF WV/FAR SW VA. IN
ADDITION...ENOUGH INSTABILITY SUGGESTED WITH COLD AIR ALOFT...TO
INTRODUCE ISOLD TSRA WITH THE WED DISTURBANCE AS WELL.
850MB TEMPS DROP TO NEAR 0C ACROSS THE NORTHERN PART OF THE
FORECAST AREA BY WED...BUT THE BETTER COLD ADVECTION COMES IN THE
EXTENDED PERIOD BEHIND THE WED DISTURBANCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
BROAD UPPER TROUGH REMAINS IN PLACE AND DOMINATES THE EXTENDED
FORECAST...GRADUALLY SHIFTING FURTHER ESE LATE IN THE PERIOD.
THIS KEEPS THE REGION IN AN UNSTABLE/UNSETTLED NORTHWEST FLOW WITH
NUMEROUS EMBEDDED SHORT WAVES. MODELS VARY CONSIDERABLY AS TO THE
TIMING AND PLACEMENT OF THESE DISTURBANCES...BUT ENOUGH AGREEMENT
THAT POPS CANNOT BE DROPPED REALLY AT ANY TIME THE OVERALL TREND
IS TO PUSH THE BETTER MOISTURE FURTHER SOUTH OF THE REGION AS THE
WEEK PROGRESSES AND 850MB TEMPS DROP BELOW 0C IN THE NORTHERN
COUNTIES. THE ENTIRE PERIOD SHOULD FEATURE BELOW NORMAL
TEMPERATURES WITH LOW CHC POPS...HIGHEST ACROSS THE MOUNTAINS AND
TOWARD THE SOUTHERN COUNTIES...WITH THE NORTHERN PIEDMONT THE
DRIEST. ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL THROUGHOUT THE
PERIOD...NO REAL CLEAR CONCERN AT THIS POINT FOR FROST/FREEZE
BECAUSE OF CYCLONIC FLOW AND CLOUDS.
&&
.AVIATION /05Z MONDAY THROUGH FRIDAY/...
AS OF 110 AM EDT MONDAY...
BULK OF THE RAIN IS HEADING NORTH OF THE AREA WITH THE WIND BECOMING
SOUTHWESTERLY. VISIBILITIES WILL IMPROVE QUICKLY AS LIGHT RAIN
TRACKS TO THE NORTH BY 08Z...THEN CEILINGS WILL LIFT TO VFR
WITHIN A COUPLE OF HOURS AFTER...DEFINITELY BY 12Z MONDAY.
SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE REGION MONDAY
AFTERNOON...FOLLOWED BY A COLD FRONT. PRESSURE RISES BEHIND THE
FRONT WILL BRING BREEZY AND GUSTY WESTERLY WINDS TO THE AREA INTO
MONDAY NIGHT.
EXTENDED AVIATION...
VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS.
THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE
IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK/RCS
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...AMS/KK/RCS
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
625 PM CDT TUE APR 21 2015
.UPDATE...THIS EVENING
ISSUED AT 624 PM CDT TUE APR 21 2015
EVEN THOUGH WE ARE GETTING SOME OUR STRONGEST WIND GUSTS RIGHT
NOW...SOUNDINGS SHOW THAT WE WILL BE NOT MIXING AS DEEP DURING THE
NEXT HOUR. THIS MEANS THAT THESE STRONG WINDS WILL NOT LAST MUCH
LONGER. SINCE IT WOULD ONLY MEAN EXTENDING THE WIND ADVISORY BY 1
HOUR...DECIDED TO JUST LET IT EXPIRE AND REPLACE IT WITH A SPECIAL
WEATHER STATEMENT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 326 PM CDT TUE APR 21 2015
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO ALBERTA AND VERY DEEP
TROUGHING OVER THE FORECAST AREA INTO THE GREAT LAKES. WITHIN THIS
TROUGH WAS AN UPPER LOW OVER EASTERN LAKE SUPERIOR...A SHORTWAVE
DROPPING SOUTH TOWARDS I-90 IN THE FORECAST AREA...AND ANOTHER
SHORTWAVE OVER NORTHEAST MN. COOL TEMPERATURES ALOFT REFLECTED BY
500MB TEMPS OF -27 TO -33C PER 12Z RAOBS...DAYTIME HEATING...NEAR
SATURATED CONDITIONS BETWEEN 700-850MB AND THE AFOREMENTIONED
SHORTWAVES HELPING TO PRODUCE PLENTY OF SHOWERS ACROSS THE
REGION....ESPECIALLY ALONG AND NORTH OF I-94. TEMPERATURES HAVE
STRUGGLED TO RISE WITH CLOUDS...PRECIP AND 850MB TEMPS OF -3 TO
-7C. READINGS HAVE ONLY CLIMBED INTO THE MID 30S TO LOW 40S. THE
COLD TEMPERATURES HAVE SUPPORTED A MIX OF RAIN AND SNOW...WITH THE
SNOW CONFINED MORESO TO HIGHER ELEVATIONS AND TAYLOR/CLARK
COUNTIES. ON TOP OF THE COOL AIR...A TIGHT PRESSURE GRADIENT AND
925MB WINDS OF 25-35 KT HAS RESULTED IN WINDS GUSTING TO THE 925MB
SPEEDS...MAKING IT FEEL FALL-LIKE. THESE WINDS ARE JUST BELOW
ADVISORY CRITERIA.
THE OVERALL UPPER PATTERN CHANGES LITTLE IN THE NEXT 24 HOURS WITH
ONLY A SLIGHT DRIFT EASTWARD OF THE UPPER LOW AND TROUGHING. THIS
SLIGHT DRIFT LOOKS TO BE ENOUGH SUCH THAT MUCH OF THE SHORTWAVE AND
INSTABILITY INDUCED SHOWERS ON WEDNESDAY WILL FALL EAST OF THE
FORECAST AREA. HOWEVER...PORTIONS OF TAYLOR AND ADAMS COULD GET
CLIPPED IN THE AFTERNOON. GETTING BACK TO TONIGHT...GENERAL MODEL
CONSENSUS SUGGESTS THE LOSS OF DAYTIME HEATING WILL ALLOW SHOWER
ACTIVITY TO BECOME MORE ISOLATED THROUGH THE EVENING...EVENTUALLY
ENDING BY MIDNIGHT.
CLOUDS LOOK TO HOLD OVER MUCH OF THE FORECAST AREA TONIGHT...AIDED
BY A SURGE OF 850MB MOISTURE CURRENTLY IN NORTHWEST ONTARIO DROPPING
SOUTHWARD WITH THE SHORTWAVE IN NORTHEAST MN. SUBSIDENCE IN THE WAKE
OF THIS SHORTWAVE...COMBINED WITH 925-700MB WINDS BACKING A BIT MORE
WESTERLY ON WEDNESDAY...WILL HELP TO RESULT IN MORE SUNSHINE.
DESPITE THE CLOUDS TONIGHT...AND A PERSISTENT BREEZE...TEMPERATURES
WILL STILL FALL AS THAT SHORTWAVE IN NORTHEAST MN DRAGS COLDER AIR
INTO THE FORECAST AREA. BY 12Z WED...850MB TEMPS ARE PROGGED TO DROP
TO -8 TO -11C...OR ALMOST 2 STANDARD DEVIATIONS BELOW NORMAL.
GUIDANCE LOWS IN THE MID 20S TO LOW 30S SEEM REASONABLE. HAVING MORE
SUNSHINE ON WEDNESDAY WILL HELP PRODUCE A WARMER DAY THAN
TODAY...ALBEIT STILL WELL BELOW NORMAL GIVEN 850MB TEMPS ONLY
CLIMBING TO -2 TO -7C BY 00Z THU. MOST LOCATIONS SHOULD CLIMB INTO
THE 40S...WITH LOW 50S LIKELY IN RIVER VALLEYS AND THE SOUTHWEST
PORTION OF THE FORECAST AREA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 PM CDT TUE APR 21 2015
THE UPPER FLOW PATTERN LOOKS TO BECOME MORE PROGRESSIVE THROUGH THE
END OF THE WEEK IN RESPONSE TO A DEEP UPPER TROUGH APPROACHING THE
PACIFIC NORTHWEST. THIS WILL HELP TO PUSH THE UPPER RIDGING AND
WARMER AIR OVER THE WESTERN U.S. TOWARDS THE FORECAST AREA. 850MB
TEMPS DO NOT CHANGE A WHOLE LOT WED NIGHT...BUT MORE IMPRESSIVE WARM
ADVECTION COMES IN FOR THU WITH 850MB TEMPS REACHING 0 TO -2C BY 00Z
FRI...AND 0 TO 4C BY 00Z SAT. LOW PRECIPITABLE WATER ON
THURSDAY...AROUND 0.1 INCHES...SHOULD HELP TO TANK DEWPOINTS AND
RESULTING RHS. COMBINED WITH A DRYING DAY ON WEDNESDAY AND A 10-15
MPH NORTHWEST BREEZE...FIRE WEATHER COULD BE A CONCERN. SEE FIRE
WEATHER SECTION BELOW.
FOR FRIDAY INTO SATURDAY...AN UPPER LOW CURRENTLY NEAR LOS ANGELES
IS PROGGED TO LIFT THROUGH THE CENTRAL PLAINS AND TRACK EASTWARD
ACROSS ILLINOIS. ALTHOUGH THIS TRACK IS SOUTH OF THE FORECAST
AREA...MOISTURE ADVECTION SPREADS NORTHWARD AHEAD OF THE UPPER LOW
TO HELP PRODUCE SOME RAIN. THE SPEED HAS SLOWED DOWN A BIT...AND AS
A RESULT DELAYED THE SPREADING OF CHANCES OF RAINFALL EASTWARD ON
FRIDAY. FURTHER DELAYS MAY BE NEEDED. RAIN CHANCES SPREAD ACROSS THE
FORECAST AREA FRIDAY NIGHT AND THEN SHIFT TO SOUTH OF I-90 ON
SATURDAY...RESULTING FROM EASTERLY FLOW DRAGGING MORE DRY AIR INTO
NORTHERN SECTIONS. OVERALL APPEARS TO BE A LIGHT RAIN...WITH THE
HEAVIER RAIN TO THE SOUTH TIED TO THE UPPER LOW FORCING.
DRIER WEATHER LOOKS TO FOLLOW SATURDAY NIGHT AND SUNDAY AS UPPER
RIDGING BUILDS BACK INTO THE FORECAST AREA FROM THE WEST.
TEMPERATURES SHOULD REBOUND CLOSER TO NORMAL AS WELL WITH MORE SUN
ON SUNDAY AND 850MB TEMPS IN THE 0-4C RANGE.
FOR EARLY NEXT WEEK UNCERTAINTY BEGINS TO INCREASE. NOT SO MUCH ON
THE UPPER PATTERN WHERE MODELS ADVERTISE TROUGHING DEVELOPING FROM
THE NORTHEAST U.S. INTO THE SOUTHEAST U.S....BUT WITH PRECIPITATION
CHANCES AS THIS TROUGH DEVELOPS. THE 21.12Z GFS HAS A SHORTWAVE
TROUGH DROPPING THROUGH THE REGION TO BRING PRECIPITATION TO THE
AREA. MEANWHILE THE 21.12Z ECMWF AND CANADIAN SUGGEST A DRY
PERIOD AS HIGH PRESSURE DOMINATES AT THE SURFACE...WITH THE
AFOREMENTIONED SHORTWAVE TROUGH FALLING APART. FOR NOW HAVE WENT
WITH THE CONSENSUS AND HAVE 20-30 PERCENT CHANCES. HOW THIS
SHORTWAVE TROUGH EVOLVES ALSO HAS AN IMPACT ON TEMPERATURES. IN
THE CASE OF THE 21.12Z GFS...IT SUGGESTS 850MB TEMPS PLUNGE TO
AROUND -4C BY 12Z TUE...ABOUT 8C COLDER THAN THE ECMWF. ALSO
FOLLOWED CONSENSUS HERE FOR NOW WITH TEMPS JUST SHY OF NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 624 PM CDT TUE APR 21 2015
RAP SOUNDINGS SHOW THAT THE WEST NORTHWINDS WILL GUST INTO THE 30
TO 35 KNOT RANGE THROUGH 22.02Z AND THEN QUICKLY DIMINISH WITH THE
LOSS OF DIURNAL HEATING. WITH STEEP LAPSE RATES BELOW 850 MB...
CYCLONIC FLOW...AND SOME MOISTURE TRAPPED BELOW THE
INVERSION...EXPECT THE CLOUDS WILL REMAIN ACROSS THE AREA. SOME
MODELS SUGGEST THAT THE CLOUDS WILL BECOME MVFR AROUND 22.06Z...
AND REMAIN THAT WAY THROUGH 22.15Z. CEILINGS WILL THEN BECOME VFR
FOR THE REMAINDER OF THE MORNING. SOUNDINGS SUGGEST THAT AS WE
HEAD INTO THE AFTERNOON THAT DRY AIR WILL MOVE IN. AS THIS
OCCURS...EXPECT THE BROKEN VFR DECK TO BECOME SCATTERED. WITH
DIURNAL HEATING AND STEEP LAPSE RATE BELOW 850 MB...EXPECT WINDS
TO GUST TO AROUND 30 KNOTS AFTER 22.15Z.
&&
.FIRE WEATHER...
ISSUED AT 326 PM CDT TUE APR 21 2015
AFTER SOME RECENT COOL/WET DAYS...CONDITIONS LOOK TO DRY OUT AGAIN
WEDNESDAY AND THURSDAY. RELATIVE HUMIDITIES ARE EXPECTED TO DROP
INTO THE 20S ON WEDNESDAY AND MAY EVEN DROP BELOW 20 PERCENT IN A
FEW SOUTHEAST MN LOCATIONS ON THURSDAY. FIGURE MUCH OF WEDNESDAY
WILL BE A DRYING DAY FOR FUELS GIVEN THE WET WEATHER...WITH A 15
TO 25 MPH NORTHWEST BREEZE AIDING IN THE DRYING. THEREFORE
THURSDAY WOULD APPEAR TO BE THE MORE CONCERNING DAY...THOUGH WINDS
LOOK LIGHTER IN THE 10 TO 15 MPH RANGE. NEVERTHELESS...WELL HAVE
TO KEEP A CLOSE EYE ON THURSDAY AND SEE TOO WHERE ALL THE
VEGETATION STANDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BOYNE
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1156 AM CDT MON APR 20 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 400 AM CDT MON APR 20 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF
STRENGTHENING LOW PRESSURE MOVING NORTH OVER SOUTHWEST LOWER
MICHIGAN. COMMA HEAD PRECIP AROUND THE LOW IS NOW SHIFTING
NORTHWEST AND EXTENDS FROM WAUTOMA TO WAUSAUKEE. FARTHER
WEST...MID-LEVEL FRONTOGENESIS IS CREATING A BAND OF RAIN OVER
WESTERN WISCONSIN AHEAD OF AN UPPER TROUGH POSITIONED OVER
SOUTH-CENTRAL CANADA AND THE NORTHERN PLAINS. WINDS SHIFT TO THE
NORTHWEST OVER WESTERN WISCONSIN AND ARE GUSTING INTO THE LOWER 30
KTS. SOME SNOW BEING REPORTED OVER NORTHERN MINNESOTA AS WELL. AS
THE LOW CONTINUES TO LIFT TO THE NORTH AND THE UPPER TROUGH SETTLES
OVER THE GREAT LAKES...PRECIP TRENDS ARE THE MAIN FORECAST CONCERN.
TODAY...THE LOW PRESSURE SYSTEM WILL TRAVEL NORTHWARD OVER WESTERN
LOWER MICHIGAN INTO NORTHERN ONTARIO. MODELS INDICATE THAT COMMA
HEAD PRECIP ASSOCIATED WITH THE LOW WILL LIFT NORTH ACROSS THE
CENTRAL FORECAST AREA EARLY THIS MORNING AND ACROSS THE CENTRAL UPPER
PENINSULA LATER IN THE MORNING. MEANWHILE...THE FGEN INDUCED RAIN
BAND WILL PIVOT NORTHEAST ACROSS CENTRAL AND NORTH-CENTRAL WISCONSIN
THIS MORNING AND NORTHEAST WISCONSIN THIS AFTERNOON. THEREFORE
EXPECT PERIODS OF RAIN THROUGH THE MORNING...BEFORE THE RAIN
GRADUALLY EXITS TO THE NORTHEAST IN THE AFTERNOON.
ADDITIONALLY...WEST WINDS WILL DRIVE COLDER AIR ACROSS THE STATE
BEHIND THE SYSTEM WHICH WILL STEEPEN LOW LEVEL LAPSE RATES...AND
PROMOTE GUSTY WINDS DEVELOPING. SOME GUSTS OVER CENTRAL AND
EAST-CENTRAL WISCONSIN COULD EXCEED 30 MPH THIS AFTERNOON. WITH THE
RAIN AND CLOUDS...COOLER HIGHS IN THE MID 40S TO AROUND 50.
TONIGHT...MID-LEVEL DRY SLOTTING WILL BE ROTATING OVERHEAD DURING
THE EVENING BEFORE DEEPER MOISTURE RETURNS AS UPPER LEVEL LOW
PRESSURE SETTLES ACROSS THE REGION. MOISTURE WILL BE THE DEEPEST
OVER FAR NORTH-CENTRAL WISCONSIN FOR THE EVENING HOURS...WHERE WILL
CARRY LOW CHANCES OF PRECIP. THEN PRECIP CHANCES WILL INCREASE FROM
NORTHWEST TO SOUTHEAST THROUGH THE OVERNIGHT. SOUNDINGS COOL ENOUGH
OVERNIGHT FOR SNOW TO BECOME THE DOMINANT PTYPE OVER CENTRAL AND
NORTH-CENTRAL WISCONSIN FOR MINOR ACCUMULATIONS ON GRASSY SURFACES.
LOWS RANGING FROM THE LOW TO MID 30S.
TUESDAY...WITH UPPER LEVEL LOW PRESSURE OVERHEAD...PERIODS OF RAIN
AND SNOW SHOWERS LOOK TO OCCUR OVER NORTH-CENTRAL WISCONSIN. MINOR
SNOW ACCUMULATIONS ARE POSSIBLE ACROSS THE NORTH DURING THE
MORNING. CHANCES OF PRECIP WILL IMPROVE THROUGH THE MORNING OVER
EASTERN WISCONSIN WHERE PRECIP COULD BE A MIX OF RAIN AND SNOW
INITIALLY BEFORE TEMPS RISE WARM ENOUGH FOR ALL RAIN. COOL WITH
HIGHS RANGING FROM NEAR 40 NORTH TO THE UPPER 40S SOUTHEAST.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 400 AM CDT MON APR 20 2015
UPPER LOW ACROSS ONTARIO WILL GRADUALLY SHIFT EAST INTO QUEBEC BY
THE END OF THE WORK WEEK. COOL CYCLONIC FLOW WILL CONTINUE TO BRING
BELOW NORMAL TEMPERATURES INTO THE WEEKEND...ALONG WITH A CHANCE OF
RAIN OR SNOW SHOWERS AT TIMES TUESDAY NIGHT INTO THURSDAY. HIGHEST
CHANCES WILL BE ACROSS THE NORTH...IN CLOSER PROXIMITY TO THE UPPER
LOW AND SHORTWAVE ENERGY. CURRENT FORECAST IS DRY FOR FRIDAY...
BUT COULD NOT RULE OUT A STRAY RAIN/SNOW SHOWER ACROSS THE NORTH.
DRY CONDITIONS ARE EXPECTED THIS WEEKEND AS HIGH PRESSURE DOMINATES
THE WEATHER PATTERN. ONLY MINOR CHANGES MADE TO MAX/MIN TEMPERATURES
AND PRECIPITATION CHANCES.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1144 AM CDT MON APR 20 2015
ANY LINGERING RAIN WITH IFR TO MVFR CIGS WILL END EARLY THIS
AFTERNOON HOURS AS A LOW PRESSURE SYSTEM EXIT THE REGION. A
BRIEF PERIOD OF VFR CONDITIONS SHOULD DEVELOP LATE THIS AFTERNOON
BEFORE AN UPPER LEVEL LOW SETTLES OVER THE REGION THIS
EVENING...BRINGING WITH IT MORE MVFR CIGS AND SHOWERY ACTIVITY. IN
NORTH CENTRAL WISCONSIN...PRECIP IS POSSIBLE STARTING AFTER
MIDNIGHT...WITH LIGHT SNOW EXPECTED THROUGH EARLY TUESDAY MORNING
BEFORE CHANGING OVER TO RAIN. THE WORST CONDITIONS WITH MODERATE
SNOW POSSIBLE AND OCCASIONAL IFR CONDITIONS SHOULD REMAIN IN
NORTHERN WISCONSIN...WITH MVFR EXPECTED ELSEWHERE BASED ON
UPSTREAM OBS WHERE TONIGHTS WEATHER IS CURRENTLY LOCATED. IN
EASTERN WISCONSIN...PRECIP SHOULD NOT DEVELOP UNTIL CLOSER TO
TUESDAY MORNING...WITH RAIN AND MVFR CONDITIONS PREVAILING.
GUSTY WNW WIND WILL DIMINISH SLIGHTLY OVERNIGHT BEFORE ANOTHER
ROUND OF GUSTY WEST WINDS IS EXPECTED FOR TUESDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......ALLEN
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
600 AM CDT MON APR 20 2015
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 400 AM CDT MON APR 20 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF
STRENGTHENING LOW PRESSURE MOVING NORTH OVER SOUTHWEST LOWER
MICHIGAN. COMMA HEAD PRECIP AROUND THE LOW IS NOW SHIFTING
NORTHWEST AND EXTENDS FROM WAUTOMA TO WAUSAUKEE. FARTHER
WEST...MID-LEVEL FRONTOGENESIS IS CREATING A BAND OF RAIN OVER
WESTERN WISCONSIN AHEAD OF AN UPPER TROUGH POSITIONED OVER
SOUTH-CENTRAL CANADA AND THE NORTHERN PLAINS. WINDS SHIFT TO THE
NORTHWEST OVER WESTERN WISCONSIN AND ARE GUSTING INTO THE LOWER 30
KTS. SOME SNOW BEING REPORTED OVER NORTHERN MINNESOTA AS WELL. AS
THE LOW CONTINUES TO LIFT TO THE NORTH AND THE UPPER TROUGH SETTLES
OVER THE GREAT LAKES...PRECIP TRENDS ARE THE MAIN FORECAST CONCERN.
TODAY...THE LOW PRESSURE SYSTEM WILL TRAVEL NORTHWARD OVER WESTERN
LOWER MICHIGAN INTO NORTHERN ONTARIO. MODELS INDICATE THAT COMMA
HEAD PRECIP ASSOCIATED WITH THE LOW WILL LIFT NORTH ACROSS THE
CENTRAL FORECAST AREA EARLY THIS MORNING AND ACROSS THE CENTRAL UPPER
PENINSULA LATER IN THE MORNING. MEANWHILE...THE FGEN INDUCED RAIN
BAND WILL PIVOT NORTHEAST ACROSS CENTRAL AND NORTH-CENTRAL WISCONSIN
THIS MORNING AND NORTHEAST WISCONSIN THIS AFTERNOON. THEREFORE
EXPECT PERIODS OF RAIN THROUGH THE MORNING...BEFORE THE RAIN
GRADUALLY EXITS TO THE NORTHEAST IN THE AFTERNOON.
ADDITIONALLY...WEST WINDS WILL DRIVE COLDER AIR ACROSS THE STATE
BEHIND THE SYSTEM WHICH WILL STEEPEN LOW LEVEL LAPSE RATES...AND
PROMOTE GUSTY WINDS DEVELOPING. SOME GUSTS OVER CENTRAL AND
EAST-CENTRAL WISCONSIN COULD EXCEED 30 MPH THIS AFTERNOON. WITH THE
RAIN AND CLOUDS...COOLER HIGHS IN THE MID 40S TO AROUND 50.
TONIGHT...MID-LEVEL DRY SLOTTING WILL BE ROTATING OVERHEAD DURING
THE EVENING BEFORE DEEPER MOISTURE RETURNS AS UPPER LEVEL LOW
PRESSURE SETTLES ACROSS THE REGION. MOISTURE WILL BE THE DEEPEST
OVER FAR NORTH-CENTRAL WISCONSIN FOR THE EVENING HOURS...WHERE WILL
CARRY LOW CHANCES OF PRECIP. THEN PRECIP CHANCES WILL INCREASE FROM
NORTHWEST TO SOUTHEAST THROUGH THE OVERNIGHT. SOUNDINGS COOL ENOUGH
OVERNIGHT FOR SNOW TO BECOME THE DOMINANT PTYPE OVER CENTRAL AND
NORTH-CENTRAL WISCONSIN FOR MINOR ACCUMULATIONS ON GRASSY SURFACES.
LOWS RANGING FROM THE LOW TO MID 30S.
TUESDAY...WITH UPPER LEVEL LOW PRESSURE OVERHEAD...PERIODS OF RAIN
AND SNOW SHOWERS LOOK TO OCCUR OVER NORTH-CENTRAL WISCONSIN. MINOR
SNOW ACCUMULATIONS ARE POSSIBLE ACROSS THE NORTH DURING THE
MORNING. CHANCES OF PRECIP WILL IMPROVE THROUGH THE MORNING OVER
EASTERN WISCONSIN WHERE PRECIP COULD BE A MIX OF RAIN AND SNOW
INITIALLY BEFORE TEMPS RISE WARM ENOUGH FOR ALL RAIN. COOL WITH
HIGHS RANGING FROM NEAR 40 NORTH TO THE UPPER 40S SOUTHEAST.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 400 AM CDT MON APR 20 2015
UPPER LOW ACROSS ONTARIO WILL GRADUALLY SHIFT EAST INTO QUEBEC BY
THE END OF THE WORK WEEK. COOL CYCLONIC FLOW WILL CONTINUE TO BRING
BELOW NORMAL TEMPERATURES INTO THE WEEKEND...ALONG WITH A CHANCE OF
RAIN OR SNOW SHOWERS AT TIMES TUESDAY NIGHT INTO THURSDAY. HIGHEST
CHANCES WILL BE ACROSS THE NORTH...IN CLOSER PROXIMITY TO THE UPPER
LOW AND SHORTWAVE ENERGY. CURRENT FORECAST IS DRY FOR FRIDAY...
BUT COULD NOT RULE OUT A STRAY RAIN/SNOW SHOWER ACROSS THE NORTH.
DRY CONDITIONS ARE EXPECTED THIS WEEKEND AS HIGH PRESSURE DOMINATES
THE WEATHER PATTERN. ONLY MINOR CHANGES MADE TO MAX/MIN TEMPERATURES
AND PRECIPITATION CHANCES.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 559 AM CDT MON APR 20 2015
STEADY RAIN WITH IFR AND LIFR CIGS WILL END FROM SOUTHWEST TO
NORTHEAST DURING THE AFTERNOON HOURS AS LOW PRESSURE SYSTEM AND
COLD FRONT EXIT THE REGION. AS THE RAIN ENDS...CONDITIONS WILL
EVENTUALLY IMPROVE BACK TO VFR IN THE AFTERNOON. A TIGHT PRESSURE
GRADIENT WILL LEAD TO GUSTY WESTERLY WINDS TODAY. THEN UPPER LEVEL
LOW PRESSURE WILL SETTLE OVER THE REGION TONIGHT WITH RAIN AND
SNOW SHOWERS...AND MVFR CIGS SPREADING SOUTHEAST ACROSS THE TAF
SITES.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......MPC
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 400 AM CDT MON APR 20 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF
STRENGTHENING LOW PRESSURE MOVING NORTH OVER SOUTHWEST LOWER
MICHIGAN. COMMA HEAD PRECIP AROUND THE LOW IS NOW SHIFTING
NORTHWEST AND EXTENDS FROM WAUTOMA TO WAUSAUKEE. FARTHER
WEST...MID-LEVEL FRONTOGENESIS IS CREATING A BAND OF RAIN OVER
WESTERN WISCONSIN AHEAD OF AN UPPER TROUGH POSITIONED OVER
SOUTH-CENTRAL CANADA AND THE NORTHERN PLAINS. WINDS SHIFT TO THE
NORTHWEST OVER WESTERN WISCONSIN AND ARE GUSTING INTO THE LOWER 30
KTS. SOME SNOW BEING REPORTED OVER NORTHERN MINNESOTA AS WELL. AS
THE LOW CONTINUES TO LIFT TO THE NORTH AND THE UPPER TROUGH SETTLES
OVER THE GREAT LAKES...PRECIP TRENDS ARE THE MAIN FORECAST CONCERN.
TODAY...THE LOW PRESSURE SYSTEM WILL TRAVEL NORTHWARD OVER WESTERN
LOWER MICHIGAN INTO NORTHERN ONTARIO. MODELS INDICATE THAT COMMA
HEAD PRECIP ASSOCIATED WITH THE LOW WILL LIFT NORTH ACROSS THE
CENTRAL FORECAST AREA EARLY THIS MORNING AND ACROSS THE CENTRAL UPPER
PENINSULA LATER IN THE MORNING. MEANWHILE...THE FGEN INDUCED RAIN
BAND WILL PIVOT NORTHEAST ACROSS CENTRAL AND NORTH-CENTRAL WISCONSIN
THIS MORNING AND NORTHEAST WISCONSIN THIS AFTERNOON. THEREFORE
EXPECT PERIODS OF RAIN THROUGH THE MORNING...BEFORE THE RAIN
GRADUALLY EXITS TO THE NORTHEAST IN THE AFTERNOON.
ADDITIONALLY...WEST WINDS WILL DRIVE COLDER AIR ACROSS THE STATE
BEHIND THE SYSTEM WHICH WILL STEEPEN LOW LEVEL LAPSE RATES...AND
PROMOTE GUSTY WINDS DEVELOPING. SOME GUSTS OVER CENTRAL AND
EAST-CENTRAL WISCONSIN COULD EXCEED 30 MPH THIS AFTERNOON. WITH THE
RAIN AND CLOUDS...COOLER HIGHS IN THE MID 40S TO AROUND 50.
TONIGHT...MID-LEVEL DRY SLOTTING WILL BE ROTATING OVERHEAD DURING
THE EVENING BEFORE DEEPER MOISTURE RETURNS AS UPPER LEVEL LOW
PRESSURE SETTLES ACROSS THE REGION. MOISTURE WILL BE THE DEEPEST
OVER FAR NORTH-CENTRAL WISCONSIN FOR THE EVENING HOURS...WHERE WILL
CARRY LOW CHANCES OF PRECIP. THEN PRECIP CHANCES WILL INCREASE FROM
NORTHWEST TO SOUTHEAST THROUGH THE OVERNIGHT. SOUNDINGS COOL ENOUGH
OVERNIGHT FOR SNOW TO BECOME THE DOMINANT PTYPE OVER CENTRAL AND
NORTH-CENTRAL WISCONSIN FOR MINOR ACCUMULATIONS ON GRASSY SURFACES.
LOWS RANGING FROM THE LOW TO MID 30S.
TUESDAY...WITH UPPER LEVEL LOW PRESSURE OVERHEAD...PERIODS OF RAIN
AND SNOW SHOWERS LOOK TO OCCUR OVER NORTH-CENTRAL WISCONSIN. MINOR
SNOW ACCUMULATIONS ARE POSSIBLE ACROSS THE NORTH DURING THE
MORNING. CHANCES OF PRECIP WILL IMPROVE THROUGH THE MORNING OVER
EASTERN WISCONSIN WHERE PRECIP COULD BE A MIX OF RAIN AND SNOW
INITIALLY BEFORE TEMPS RISE WARM ENOUGH FOR ALL RAIN. COOL WITH
HIGHS RANGING FROM NEAR 40 NORTH TO THE UPPER 40S SOUTHEAST.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 400 AM CDT MON APR 20 2015
UPPER LOW ACROSS ONTARIO WILL GRADUALLY SHIFT EAST INTO QUEBEC BY
THE END OF THE WORK WEEK. COOL CYCLONIC FLOW WILL CONTINUE TO BRING
BELOW NORMAL TEMPERATURES INTO THE WEEKEND...ALONG WITH A CHANCE OF
RAIN OR SNOW SHOWERS AT TIMES TUESDAY NIGHT INTO THURSDAY. HIGHEST
CHANCES WILL BE ACROSS THE NORTH...IN CLOSER PROXIMITY TO THE UPPER
LOW AND SHORTWAVE ENERGY. CURRENT FORECAST IS DRY FOR FRIDAY...
BUT COULD NOT RULE OUT A STRAY RAIN/SNOW SHOWER ACROSS THE NORTH.
DRY CONDITIONS ARE EXPECTED THIS WEEKEND AS HIGH PRESSURE DOMINATES
THE WEATHER PATTERN. ONLY MINOR CHANGES MADE TO MAX/MIN TEMPERATURES
AND PRECIPITATION CHANCES.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1140 PM CDT SUN APR 19 2015
STEADY RAIN CONTINUES TO SPREAD OVER THE TAF SITES
EARLY THIS MORNING AS LOW PRESSURE LIFTS THROUGH THE CENTRAL
GREAT LAKES. THIS ACTIVITY WILL CAUSE CONDITIONS TO FALL TO
IFR...WITH LIFR CIGS POSSIBLE AT TIMES. RAIN WILL END FROM WEST
TO EAST LATER THIS MORNING AND DURING THE AFTERNOON HOURS AS THE
LOW LIFTS NORTH OVER WESTERN ONTARIO. CONDITIONS WILL EVENTUALLY
IMPROVE BACK TO VFR AS THE RAIN ENDS DURING THE AFTERNOON AND
EVENING HOURS. A TIGHT PRESSURE GRADIENT WILL LEAD TO GUSTY
WESTERLY WINDS SUNDAY AFTERNOON AS THE LOW LIFTS TO THE NORTH.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
1033 PM PDT TUE APR 21 2015
.UPDATE...
A QUICK FORECAST UPDATE WAS SENT TO REMOVE MENTION OF THUNDER AND
REDUCE OVERALL WIND SPEEDS THROUGH THE OVERNIGHT HOURS.
WHILE THE THUNDERSTORM ACTIVITY FROM EARLIER THIS EVENING HAS
DIMINISHED, THERE CONTINUE TO BE SOME SHOWERS MOVING WESTWARD
ACROSS CHURCHILL, MINERAL, LYON AND MONO COUNTIES. THE LATEST NAM
AND HRRR KEEP SOME ACTIVITY GOING MAINLY SOUTH OF HIGHWAY 50, BUT
THERE IS A SMALL POSSIBILITY FOR SOME LATE NIGHT SPRINKLES
REACHING THE RENO AND CARSON VICINITY. LITTLE OR NO MEASURABLE
RAINFALL IS EXPECTED FROM THESE WEAK SHOWERS.
THE HIGHEST RAIN TOTALS FROM EARLIER CONVECTIVE ACTIVITY WERE
ALMOST ONE HALF INCH NEAR DONNER LAKE, AND ISOLATED REPORTS NEAR
0.25 INCH AROUND TRUCKEE AND PLUMAS-EUREKA STATE PARK. OTHERWISE,
RAIN TOTALS WERE SPOTTY AND GENERALLY 0.10 INCH OR LESS.
WHILE THE GENERAL WIND FLOW TONIGHT IS EXPECTED TO BE NORTHWEST TO
NORTH, THE SHOWERS OVER WEST CENTRAL NV HAVE PRODUCED PRODUCED
BRIEF EAST TO NORTHEAST WINDS, INCLUDING A GUST OF 30 MPH AT
FALLON AROUND 930 PM.
DUE TO THE RAIN EARLIER TODAY AROUND TRUCKEE, PATCHY FOG HAS BEGUN
TO DEVELOP AT THE KTRK AIRPORT. VSBY WILL DROP TO 1 MILE OR LESS
AT TIMES THRU EARLY WED MORNING. MJD
&&
.PREVIOUS DISCUSSION... /ISSUED 108 PM PDT TUE APR 21 2015/
SYNOPSIS...
LOW PRESSURE WILL MOVE INLAND TODAY THROUGH THURSDAY BRINGING
HIGHER CHANCES OF SHOWERS AND THUNDERSTORMS AS WELL AS COOLER
TEMPERATURES AREA WIDE. DRIER WESTERLY FLOW RETURNS BY THIS
WEEKEND DECREASING THE POTENTIAL FOR SHOWERS.
SHORT TERM...
UPPER LEVEL LOW ACROSS SOUTHERN CALIFORNIA IS SLOWLY MAKES ITS WAY
NORTH AND EAST TODAY WHILE A PACIFIC TROUGH APPROACHES THE
PACIFIC NORTHWEST. THE COMBINATION OF THESE TWO SYNOPTIC FEATURES
WILL ALLOW FOR SOME LARGE-SCALE ASCENT ACROSS THE SIERRA AND WESTERN
NEVADA OVER THE NEXT COUPLE OF DAYS. THAT COMBINED WITH DAYTIME
HEATING AND SUFFICIENT MOISTURE WILL RESULT IN ENOUGH INSTABILITY TO
PRODUCE THUNDERSTORMS THIS AFTERNOON AND EVENING AND ON WEDNESDAY AS
WELL.
RENO`S MORNING SOUNDING WAS SHOWING A FAIRLY UNSTABLE ATMOSPHERE
THIS MORNING WITH LIFTED INDICES AROUND -4. THAT ALONG WITH
EFFICIENT DAYTIME HEATING SHOULD ALLOW DEVELOPMENT OF THUNDERSTORMS
A BIT EARLIER THAN YESTERDAY. AS OF 11AM, WE ARE ALREADY SEEING SOME
DECENT CUMULUS BUILDUPS ACROSS THE REGION. MAIN CONCERNS WITH THE
STORMS TODAY WILL BE GUSTY WINDS AROUND 40 MPH, SMALL HAIL, AND
LIGHTNING. THERE WERE A COUPLE OF SMALL FIRE STARTS FROM YESTERDAY`S
LIGHTNING, SO A FEW STARTS WILL BE POSSIBLE THIS AFTERNOON AS WELL.
DROUGHT STRESSED LARGE FUELS IN THE HIGHER TERRAIN WILL BE MORE
SUSCEPTIBLE TO LIGHTNING THAN THE FINE FUELS OR GRASSES, WHICH
HAVEN`T CURED YET.
WEDNESDAY`S THUNDERSTORM COVERAGE IS NOT QUITE AS CERTAIN. ALTHOUGH
INSTABILITY AND MOISTURE APPEAR BETTER FOR THUNDERSTORM DEVELOPMENT,
RESIDUAL CLOUD COVER FROM TODAY`S STORMS OR MID LEVEL CLOUDS FROM
THE APPROACHING TROUGH COULD LIMIT THUNDERSTORMS DEVELOPING ON
WEDNESDAY.
BY THURSDAY THE UPPER LOW ACROSS SOUTHERN CA/NV WILL MOVE SOUTH AND
EAST AS THE LARGER TROUGH MOVES INTO THE PACIFIC NORTHWEST. RESIDUAL
MOISTURE AND UPPER LEVEL ASCENT WILL BE ENOUGH TO KEEP SHOWERS
ACROSS THE REGION THROUGH THE END OF THE WEEK, ESPECIALLY SOUTH OF
HIGHWAY 50. ON FRIDAY THE TROUGH DROPS SOUTH ACROSS NEVADA BRINGING
A COOLING TREND AS WELL AS SOME CHANCES FOR PRECIPITATION FOR THE
START OF THE WEEKEND. COOLER TEMPERATURES WILL ALLOW RELATIVE
HUMIDITY VALUES TO START TO RISE THROUGH THE END OF THE WEEK, EASING
FIRE WEATHER CONCERNS AND THE LIKELIHOOD OF ANY HOLDOVERS FROM
LIGHTNING. WEISHAHN
LONG TERM...SATURDAY THROUGH TUESDAY...
UPPER RIDGE WILL DOMINATE MOST OF THIS PERIOD ALTHOUGH MEDIUM
RANGE MODELS CONTINUE TO SHOW VARIATION IN THE AMPLITUDE OF RIDGE.
CONFIDENCE IS HIGH THAT THERE WILL BE NO SIGNIFICANT STORMS.
HOWEVER, DEPENDING ON AMPLITUDE OF TROUGH, THERE COULD BE A SMALL
CHANCE OF SHOWERS NEAR THE OREGON BORDER SATURDAY AND AGAIN
TUESDAY AS SHORTWAVE ENERGY PUSHES THROUGH THE PACNW AND BRUSHES
OUR AREA. IN ADDITION, THIS FLATTER SOLUTION WOULD RESULT IN
LOCALLY BREEZY CONDITIONS EARLY NEXT WEEK. OUR FORECAST WAS
ESSENTIALLY UNCHANGED AND MAINTAINS A LOW CHANCE OF SHOWERS NORTH
SATURDAY AND AGAIN TUESDAY WITH BREEZY AFTERNOON WINDS MON-TUE.
TEMPERATURES WILL REMAIN ABOVE NORMAL WITH 60S AND 70S FOR THE
MOST PART. HOHMANN
AVIATION...
SHOWERS AND THUNDERSTORMS WILL BE A BIT MORE NUMEROUS THIS AFTERNOON
AND EARLY EVENING WITH THE MAIN THREAT BEING GUSTY OUTFLOW WINDS TO
35+KT, ESPECIALLY WITH ANY STORMS THAT MOVE ONTO THE LOWER VALLEY
FLOORS. MOST OF THE EASTERN SIERRA AND FAR WESTERN NV AIRPORTS WILL
REQUIRE A VCTS WITH A 40% CHANCE OF A DIRECT HIT AT KTRK/KTVL AND
20% CHANCE AT KRNO/KCXP/KMMH. CHANCES ARE MUCH LOWER IN THE BASIN
AND RANGE AND ANY STORMS THAT MIGHT AFFECT KNFL/KLOL WOULD BE AFTER
00Z. ONE OF OUR HIGHER RESOLUTION MODELS INDICATE CONVECTION
DEVELOPING VCNTY KNFL AROUND 03Z-05Z.
THAT SAME MODEL INDICATES ANOTHER MESOSCALE GUST FRONT DEVELOPING
ALONG THE EASTERN SLOPES OF THE SIERRA 22Z-24Z, GENERALLY NEAR AND
NORTH OF HIGHWAY 50, AND THEN SPREADING EASTWARD ACROSS THE BASIN
AND RANGE DURING THE EVENING. THIS WOULD PRODUCE A 2-3 HOUR WINDOW
OF GUSTY WEST WINDS TO 25-30KT. A FEW SHOWERS MAY CONTINUE OVERNIGHT
BEFORE SHOWERS AND THUNDERSTORMS INCREASE AGAIN WEDNESDAY AFTERNOON.
HOHMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
320 AM MDT WED APR 22 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 306 AM MDT WED APR 22 2015
A WEAK UPPER LEVEL RIDGE WILL BUILD INTO THE AREA TODAY THRU TONIGHT
WITH MAINLY WLY FLOW ALOFT. AT THE SFC LOW PRES WILL WILL INTENSIFY
OVER WESTERN COLORADO ALLOWING FOR INCREASING SSE LOW LVL FLOW
ACROSS NERN CO THRU THE AFTN HOURS. MAY SEE A DENVER CYCLONE DVLP
THIS AFTN WITH A CONVERGENCE ZONE SETTING UP MAINLY TO THE SOUTH AND
EAST OF DENVER. PRECIPITABLE WATER VALUES ARE FCST TO BE SIMILAR
TO YESTERDAY OVER THE MTNS AND FOOTHILLS WITH SLIGHTLY HIGHER
VALUES DEVELOPING OVER THE PLAINS LATER THIS AFTN AND EVENING. SFC
BASED CAPES WILL GENERALLY BE 500 J/KG OR LESS EXCEPT ACROSS PARK
COUNTY AND OVER THE PALMER DIVIDE WHERE VALUES MAY BE SLIGHTLY
HIGHER.
AT THIS TIME WILL KEEP IN A CHC OF SHOWERS AND A FEW TSTMS OVER THE
HIGHER TERRAIN FOR THIS AFTN AND EVENING WITH BETTER COVERAGE
EXPECTED ALONG AND SOUTH OF I-70. AT LOWER ELEVATIONS APPEARS BEST
CHC FOR INITIAL SHOWER AND TSTM DEVELOPMENT WILL BE ALONG THE DENVER
CONVERGENCE TO THE S AND E OF DENVER SO WILL HAVE CHC POPS ACROSS
THE PALMER DIVIDE EXTENDING TOWARDS LIMON. TO THE NORTH AND NE OF
DENVER PCPN CHANCES LOOK LOWER AT THIS TIME EXTENDING INTO THE FAR
NORTHEAST CORNER. AS FOR HIGHS THIS AFTN 850-700 MB READINGS ARE
FCST TO RISE A FEW MORE DEGREES SO WILL HAVE READINGS IN THE MID
60S TO LOWER 70S OVER NERN CO.
FOR TONIGHT EXPECT LINGERING SHOWERS AND A FEW TSTMS THRU THE EARLY
EVENING HOURS HOWEVER MOST ACTIVITY SHOULD GRADUALLY END BETWEEN 03Z
AND 06Z. A FEW SHOWERS MAY LINGER OVER THE ERN PLAINS AFTER
MIDNIGHT SO WILL KEEP IN SOME LOW POPS IN THESE AREAS BETWEEN 06Z
AND 12Z.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 306 AM MDT WED APR 22 2015
ON THURSDAY...THE UPPER RIDGE AXIS WILL BE LOCATED TO THE EAST OF
COLORADO. THE FLOW ALOFT WILL BECOME SOUTHWESTERLY WITH WEAK MID
LEVEL QG ASCENT DEVELOPING. THE MDLS MAINTAIN A SURFACE TROUGH
ALONG THE FRONT RANGE. THE FORECAST SOUNDINGS FROM THE NAM12
INDICATE DECENT MOISTURE...SHEAR AND INSTABILITY IN THE AFTN FOR A
CHANCE OF SEVERE WEATHER. FORECAST CAPES AT DENVER 1800-1900 J/KG
AT AKRON...FAVORABLE SHEAR PROFILE AS WELL WITH LOW LVL SELY WINDS
TRANSITIONING TO WSWLY IN THE MID LEVELS. WITH THE LOW LEVEL SELY
WIND COMPONENT...LOOKS LIKE FAVORABLE DEVELOPMENT FOR A DENVER
CYCLONE. BEST POTENTIAL FOR SEVERE STORMS NEAR DENVER WILL BE
ALONG THIS CONVERGENCE LINE. THURSDAY NIGHT AND FRIDAY...THE MDLS
MOVE THE UPPER LOW OVER BAJA AND MOVE IT ACROSS COLORADO IN THE
12-18Z TIME FRAME. MDT QG ASCENT ASSOCIATED WITH THE TROUGH OVER
SRN AND ERN COLORADO FRIDAY MORNING. WL KEEP CHANCE OF SHOWERS
GOING IN THE MOUNTAINS THURSDAY NIGHT. WINDS ALOFT TRANSITION FM
SWLY TO NWLY FRIDAY WITH THE PASSAGE OF THE UPPER TROF AXIS.
COOLER TEMPERATURES WITH THE POTENTIAL OF SOME LIGHT SNOW IN THE
MOUNTAINS...MAYBE 1-4 INCHES IN THE 06Z TO 18Z TIME FRAME ON
FRIDAY. ACROSS THE NORTHEAST PLAINS...FAVORABLE INSTABILITY IN
SPITE OF THE COOLER TEMPERATURES. CAPES FRI AFTN COULD BE IN THE
800-1200 J/KG RANGE. THE AMS DOES STABILIZE UNDER THE INFLUENCE OF
A SHORT WAVE RIDGE ON SATURDAY. IT WILL REMAIN UNSETTLED HOWEVER
WITH THE CHC OF SHOWERS AND MAYBE AN EMBEDDED TSTM SATURDAY AFTN.
THE NEXT DEVELOPING SYSTEM IS PROGGED IMPACT COLORADO LATE
SATURDAY AND POSSIBLY INTO EARLY MONDAY. THE ECMWF...CANADIAN AND
GFS MDLS MOVE THIS TROUGH FROM THE PACIFIC NORTHWEST TO NEAR THE
FOUR CORNERS REGION BY 18Z SUNDAY THEN EAST TOWARDS THE TX
PANHANDLE BY 12Z MONDAY. AS A RESULT...THE POTENTIAL FOR ANOTHER
PERIOD OF WIDESPREAD MOUNTAIN SNOW FOR THE FRONT RANGE...WITH A
MIX OF PCPN OVER THE NORTHEAST PLAINS/PALMER DIVIDE DOES EXIST
THROUGH MONDAY MORNING. PLENTY OF UNCERTAINTY AS THE MDLS DO
DIFFER IN TIMING/TRACK ONCE THIS SYSTEM LEAVES THE FOUR CORNERS
AND MAKES ITS WAY ACROSS NEW MX. THE AMOUNT OF PCPN AGAIN
DEPENDENT ON THE TRACK OF THE TROUGH. HIGH PRESSURE AT THE SFC AND
ALOFT WILL BUILD INTO COLORADO FM THE WEST BY TUESDAY OF NEXT
WEEK.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 306 AM MDT WED APR 22 2015
WINDS EARLY THIS MORNING WERE MAINLY SLY AS A WEAK CYCLONE WAS
LOCATED TO THE NW OF DIA. BY EARLY AFTN NOT REAL CONFIDENT AS TO
WHERE THE DENVER CYCLONE WILL BE LOCATED AS IT COULD REMAIN NEAR THE
AIRPORT OR BE FURTHER EAST. BOTH THE HRRR AND RAP KEEP THE
CONVERGENCE ZN TO THE S AND E OF DIA THRU THE AFTN WITH MAINLY
NLY WINDS THRU THE AFTN HOURS. IF THIS IS THE CASE THEN THE BEST
CHANCE OF INITIAL SHOWERS/TSTMS WOULD STAY TO THE S AND E.
HOWEVER OUTFLOW BOUNDARIES COULD MOVE NORTH BY LATE AFTN AND
TRIGGER SOME ADDITIONAL ACTIVITY NR DIA SO WILL KEEP IN A TEMPO
GROUP BETWEEN 22Z AND 01Z.
OVERALL INSTABILITY IS SOMEWHAT LIMITED WHICH WOULD LIMIT
INTENSITY OF STORMS BUT THERE WILL BE SOME ERRACTIC GUSTY WINDS FM
THE STORMS. AFTER 01Z PCPN THREAT SHOULD GRADUALLY DECREASE BY
03Z. WILL TREND WINDS BACK TO DRAINAGE AFTER 03Z WHICH SHOULD
CONTINUE OVERNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM...COOPER
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS MIAMI FL
348 AM EDT WED APR 22 2015
.DISCUSSION...
THE RECENT UPTICK IN STRONG THUNDERSTORMS ACROSS THE REGION THIS
WEEK, IS PARTLY DUE TO THE POSITION OF A ZONAL UPPER JET FROM THE
US/MEXICO BORDER THROUGH THE FLORIDA PANHANDLE. SOUTH FLORIDA HAS
BEEN ON THE SOUTHERN EDGE OF THIS WESTERLY FLOW. THE STRENGTH OF THE
UPPER JET IS UNUSUAL, ROUGHLY 3 STANDARD DEVIATIONS ABOVE NORMAL,
AND IS DRIVEN NOT ONLY BY THE BLOCKY H5 PATTERN ACROSS NORTH
AMERICA, BUT ALSO BY THE UPPER RIDGE OVER THE CARIBBEAN WHICH HAS
DELIVERED MANY OPPRESSIVELY WARM DAYS RECENTLY. HOWEVER, TODAY
CLOUDS WILL BE A MITIGATING FACTOR WITH REGARDS TO STRONG CONVECTIVE
INITIATION, AND PERHAPS THIS IS REFLECTED IN NOT TOO IMPRESSIVE CAPE
VALUES FROM MODEL SOUNDINGS. IN CONTRAST, RUC13 SOUNDINGS DO HAVE 0-
6KM SHEAR VALUES NEAR 45 M/S AND H7-H5 LAPSE RATES 6C/KM AT MIA BY
LATE MORNING. A SHRTWV ARRIVING FROM THE GULF OVERNIGHT HAS KEPT
NORTHERN ZONES WET, AND MOISTURE WILL CONTINUE TO BE ABUNDANT SOUTH
OF THE DWINDLING FRONT OVER LAKE OKEECHOBEE. NUMEROUS SHOWERS AND
THUNDERSTORMS, NOW ENTERING THE FLORIDA STRAITS, MAY ALSO COMPLICATE
MATTERS THIS MORNING. ANY BREAKS IN THE CLOUDINESS THIS AFTERNOON,
CAN VERY WELL LEAD TO STRONG THUNDERSTORMS. MODELS FOCUSING HIGHEST
POP ACROSS BROWARD AND MIAMI-DADE TODAY. PWATS AROUND 2" AND LITTLE
DIRECTIONAL SHEAR THROUGH THE COLUMN WILL MAKE TRAINING OF STORMS
AND VERY HEAVY RAINFALL POSSIBLE.
THURSDAY LOOKS SIMILAR TO TODAY, WITH THE ONLY DIFFERENCE A SLIGHT
BACKING OF MID AND UPPER LEVEL WINDS. THE VERY SUBTLE CAA THIS
PROVIDES ALOFT MAY ENHANCE LAPSE RATES A TAD. MORNING CLOUDS MAY NOT
BE AS MUCH OF AN ISSUE AS THEY ARE TODAY, AS PRECIP TONIGHT LOOKS
LESS COMPARED TO WHAT IS HAPPENING THIS MORNING.
HIGH PRESSURE MOVING INTO THE SOUTHEASTERN CONUS SHOULD DELIVER A
SLUG OF RELATIVELY DRIER AIR IN THE MIDLEVELS ON FRIDAY. THIS
COMBINED WITH SLIGHTLY WARMING H5 TEMPS SHOULD LEAD TO LESS COVERAGE
AND STORMS FOCUSED MORE INLAND WITH CONVERGING SEA BREEZES. EVEN
DRIER AIR ARRIVES THIS WEEKEND AND PWATS CONTINUE TO SLOWLY FALL.
HOWEVER, RISING H85 TEMPS TO +19C MEAN 90F POTENTIALLY FOR ALL THE
BIG CITIES AGAIN, ESPECIALLY ON SUNDAY. THE QUIETER PATTERN SHOULD
LAST INTO EARLIER NEXT WEEK. ALTHOUGH SEVERAL DAYS AWAY, BOTH THE
GFS/ECMWF ARE BULLISH REGARDING A DEEP EASTERN TROUGH AND A NEARING
COLD FRONT AT THE END OF THE FORECAST.
&&
.MARINE...
ALTHOUGH WINDS WILL REMAIN BELOW 15 KTS AND SEAS NO GREATER THAN 3
FEET THROUGH THE FORECAST, SHOWERS AND THUNDERSTORMS MAY BE NUMEROUS
AT TIMES TODAY AND THURSDAY. SOME OF WHICH COULD BE STRONG. WIND
DIRECTION WILL BECOME INCREASINGLY SW AND W THROUGH THE WEEKEND FROM
10-15 KTS BY SUNDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 70 88 72 / 60 10 50 20
FORT LAUDERDALE 85 74 87 74 / 70 20 50 20
MIAMI 87 74 90 75 / 70 30 50 20
NAPLES 84 72 86 74 / 40 10 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...21/KM
LONG TERM....21/KM
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1239 AM CDT WED APR 22 2015
.UPDATE...
ISSUED AT 1238 AM CDT WED APR 22 2015
UPDATED AVIATION SECTION FOR 06Z TAFS.
UPDATE
FOR AVIATION SECTION ONLY.
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 215 PM CDT TUE APR 21 2015
NEAR TERM ON TRACK...AS CONVECTION CONTINUES TO TAKE SHAPE OVER
SOUTHERN INTO SOUTHEAST MISSOURI...LIGHTNING NOW OBSERVED WEST OF
OUR CWFA. WILL CONTINUE TO MONITOR FOR THE POSSIBILITY OF SOME
HAIL AND GUSTY WINDS GIVEN THE STEEP LAPSE RATES AND LOW FREEZING
LEVELS...DESPITE LACK OF LOW LEVEL MOISTURE. THE CHANCES WILL
CONTINUE THROUGH THE OVERNIGHT AS A BOUNDARY SETTLES SOUTH ACROSS
THE REGION. WILL DIMINISH POPS FROM NW TO SE WEDNESDAY MORNING...DRY
BY AFTERNOON. WILL KEEP IT DRY WEDNESDAY NIGHT THROUGH THURSDAY
WITH WEAK HIGH PRESSURE ANGLING IN FROM THE UPPER MIDWEST. CHANCES
OF SHOWERS MAY EXIST JUST SOUTH OF THE AREA NEAR OUR CWFA BORDER.
CAN ADJUST IF NEED BE. TEMPS A BLEND OF MOS AND EXISTING NUMBERS.
NAM HIGH RES AND HRRR A REASONABLE APPROACH FOR CONVECTIVE TRENDS
THROUGH 06Z.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 215 PM CDT TUE APR 21 2015
THE OPERATIONAL MODELS ARE TRYING TO FALL SOMEWHAT IN LINE WITH
PRIOR ENSEMBLE MEAN SOLUTIONS THROUGH SUNDAY. ALL IN ALL...
CONFIDENCE CONTINUES TO INCREASE FOR THE FIRST SYSTEM FRIDAY
THROUGH SATURDAY. UPPER TROF SHOULD EJECT NE INTO THE PLAINS BY
00Z SAT WITH MOISTURE QUICKLY SPREADING EAST BY FRIDAY AFTERNOON
AND EVENING. S/WV RIDGE AHEAD OF THE TROF NOT STRONG ENOUGH TO
WARD OFF ONCOMING SHRA/TSRA CHANCE. SO WE ARE ON THE AGGRESSIVE
SIDE OF THE ENVELOPE. LIKELY POPS STILL IN PLAY FOR FRIDAY NIGHT
WITH CHANCE TO LOW END LIKELY SATURDAY AS WELL...AS THE UPPER TROF
WEAKENS...AND THE REMNANT ENERGY TURNS ESE ACROSS THE AREA
SATURDAY...CONTINUING THE CHANCE OF CONVECTION. SURFACE BOUNDARY
SHOULD STAY JUST TO OUR SOUTH...SO ESSENTIALLY ELEVATED CONVECTION.
CHANCES TAIL OFF SATURDAY NIGHT WITH A DRY FORECAST IN PLACE FOR
SUNDAY. FOR MONDAY THROUGH TUESDAY...THE ENSEMBLE MEAN SOLUTIONS
WERE UTILIZED AND OPERATIONAL MODELS THROWN OUT. A HIGHLY COMPLEX
PATTERN IS FORECAST TO EVOLVE WITH SOME KIND OF A TROUGH EAST OF
THE PLAINS AND RIDGE WEST. HOWEVER THERE IS TOO MUCH VARIABILITY
IN THE DETAILS TO SIDE WITH ANY OPS SOLUTION AT THIS POINT. ITS
GOING TO CHANGE. WE FEE COMFORTABLE MAINTAINING LOW CHANCE POPS
FOR SHOWERS GIVEN THE UNSETTLED LOOK TO THE PATTERN. TEMPS WERE A
BLEND OF BASE MODEL OUTPUT AND EXISTING FORECAST NUMBERS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 215 PM CDT TUE APR 21 2015
NEAR TERM ON TRACK...AS CONVECTION CONTINUES TO TAKE SHAPE OVER
SOUTHERN INTO SOUTHEAST MISSOURI...LIGHTNING NOW OBSERVED WEST OF
OUR CWFA. WILL CONTINUE TO MONITOR FOR THE POSSIBILITY OF SOME
HAIL AND GUSTY WINDS GIVEN THE STEEP LAPSE RATES AND LOW FREEZING
LEVELS...DESPITE LACK OF LOW LEVEL MOISTURE. THE CHANCES WILL
CONTINUE THROUGH THE OVERNIGHT AS A BOUNDARY SETTLES SOUTH ACROSS
THE REGION. WILL DIMINISH POPS FROM NW TO SE WEDNESDAY MORNING...DRY
BY AFTERNOON. WILL KEEP IT DRY WEDNESDAY NIGHT THROUGH THURSDAY
WITH WEAK HIGH PRESSURE ANGLING IN FROM THE UPPER MIDWEST. CHANCES
OF SHOWERS MAY EXIST JUST SOUTH OF THE AREA NEAR OUR CWFA BORDER.
CAN ADJUST IF NEED BE. TEMPS A BLEND OF MOS AND EXISTING NUMBERS.
NAM HIGH RES AND HRRR A REASONABLE APPROACH FOR CONVECTIVE TRENDS
THROUGH 06Z.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 215 PM CDT TUE APR 21 2015
THE OPERATIONAL MODELS ARE TRYING TO FALL SOMEWHAT IN LINE WITH
PRIOR ENSEMBLE MEAN SOLUTIONS THROUGH SUNDAY. ALL IN ALL...
CONFIDENCE CONTINUES TO INCREASE FOR THE FIRST SYSTEM FRIDAY
THROUGH SATURDAY. UPPER TROF SHOULD EJECT NE INTO THE PLAINS BY
00Z SAT WITH MOISTURE QUICKLY SPREADING EAST BY FRIDAY AFTERNOON
AND EVENING. S/WV RIDGE AHEAD OF THE TROF NOT STRONG ENOUGH TO
WARD OFF ONCOMING SHRA/TSRA CHANCE. SO WE ARE ON THE AGGRESSIVE
SIDE OF THE ENVELOPE. LIKELY POPS STILL IN PLAY FOR FRIDAY NIGHT
WITH CHANCE TO LOW END LIKELY SATURDAY AS WELL...AS THE UPPER TROF
WEAKENS...AND THE REMNANT ENERGY TURNS ESE ACROSS THE AREA
SATURDAY...CONTINUING THE CHANCE OF CONVECTION. SURFACE BOUNDARY
SHOULD STAY JUST TO OUR SOUTH...SO ESSENTIALLY ELEVATED CONVECTION.
CHANCES TAIL OFF SATURDAY NIGHT WITH A DRY FORECAST IN PLACE FOR
SUNDAY. FOR MONDAY THROUGH TUESDAY...THE ENSEMBLE MEAN SOLUTIONS
WERE UTILIZED AND OPERATIONAL MODELS THROWN OUT. A HIGHLY COMPLEX
PATTERN IS FORECAST TO EVOLVE WITH SOME KIND OF A TROUGH EAST OF
THE PLAINS AND RIDGE WEST. HOWEVER THERE IS TOO MUCH VARIABILITY
IN THE DETAILS TO SIDE WITH ANY OPS SOLUTION AT THIS POINT. ITS
GOING TO CHANGE. WE FEE COMFORTABLE MAINTAINING LOW CHANCE POPS
FOR SHOWERS GIVEN THE UNSETTLED LOOK TO THE PATTERN. TEMPS WERE A
BLEND OF BASE MODEL OUTPUT AND EXISTING FORECAST NUMBERS.
&&
.AVIATION...
ISSUED AT 1238 AM CDT WED APR 22 2015
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE FORECAST PERIOD. COLD
FRONT ADVANCING IN FROM THE NORTH WILL LEAD TO VCSH AT ALL
TERMINALS TONIGHT WITH WINDS SHIFTING AROUND TO THE NORTHWEST BY
TMRW MORNING. COULD HAVE SOME GUSTS UP TO 20 KTS DURING THE DAY AT
EVV/OWB. HIGH PRESSURE WILL BUILD IN BY TMRW EVENING.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SP
AVIATION...SP
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
302 AM EDT WED APR 22 2015
.UPDATE...
ISSUED AT 1114 PM EDT TUE APR 21 2015
PREVIOUS SHORT TERM DISCUSSION SPELLED OUT THE SITUATION QUITE WELL
FOR OVERNIGHT INTO WED. AFTER CONSIDERING THE DEEP MOISTURE ON 00Z
KINL/CWPL SOUNDINGS...850MB TEMPS FALLING AT LEAST ANOTHER 2C
OVERNIGHT AND CONTINUED CYCLONIC FLOW...FEEL ADVY ACCUMULATIONS ARE
LIKELY TO OCCUR OVER A DECENT AREA OF GOGEBIC/ONTONAGON COUNTIES...
IN PARTICULAR THE HIGH TERRAIN. WOULD NOT BE SURPRISED TO SEE A FEW
SPOTS IN THE HIGH TERRAIN TOP 5 INCHES BY NOON WED. PROBABLY COULD
HAVE EXTENDED ADVY N AND E THRU THE KEWEENAW AND INTO BARAGA COUNTY
AS AIR MASS PASSING OVER THE LAKE WILL BE A LITTLE COLDER THAN DOWN
TOWARD KIWD. RECENT RADAR TRENDS ARE ALSO A CONCERN WITH INCREASING
COVERAGE AND INTENSITY OF SNOW IN THAT AREA. ALSO BUMPED UP SNOW
ACCUMLATIONS INTO THE ERN FCST AREA...E OF MARQUETTE AS 850MB
THERMAL TROF WITH TEMPS AS LOW AS -14C WILL BE AIMING SE ACROSS THE
LAKE AND INTO THAT AREA WED MORNING. HAVE AMOUNTS UP TO AROUND 3
INCHES IN THAT AREA BY LATE WED MORNING...BUT THAT COULD END UP
BEING TOO CONSERVATIVE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 352 PM EDT TUE APR 21 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO OVER
THE UPR LKS DOWNSTREAM OF HI AMPLITUDE UPR RDG OVER WRN NAMERICA.
COMBINATION OF DEEP CYC FLOW W TO NW FLOW AND INSTABILITY ENHANCED
BY DAYTIME HEATING UNDER ACCOMAPANYING THERMAL TROF /12Z H5 TEMP AT
GRB WAS -31C/ AND DEEP MSTR SHOWN ON THE 12Z RAOBS IS RESULTING IN
SCT-NMRS SN SHOWERS THAT ARE MIXED WITH RA IN THE WARMER LOCATIONS.
BUT COLDER CLD TOP TEMPS/MORE WIDESRPEAD SN SHOWERS ARE CONFINED
MAINLY TO NW ONTARIO/FAR NRN MN IN AREA WHERE MODELS INDICATE DEEP
QVECTOR CNVGC.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS AND POTENTIAL SN
ACCUMS ASSOCIATED WITH DEEP CYC...MOIST NW FLOW ARND SLOW MOVING
CLOSED LO TO THE NE OF UPR MI.
CLOSED LO CENTERED OVER ERN LK SUP THIS AFTN IS FCST TO DRIFT SLOWLY
TO THE NE AND TO JUST S OF JAMES BAY ON WED. ALTHOUGH ACCOMPANYING
DEEP LYR QVECTOR CNVGC THAT IS SUPPORTING COLDER CLD TOPS TO THE NW
IS FCST TO REMAIN TO THE N OF UPR MI...PERSISTENT MOIST...CYC NW
FLOW ARND THIS FEATURE WL MAINTAIN AT LEAST CHC POPS OVER THE CWA
THRU WED...WITH THE LOWER POPS GENERALLY OVER THE SCENTRAL AND THE
HIER POPS OVER THE HIER TERRAIN OF THE NW WITH UPSLOPE WIND
COMPONENT. BUT LOSS OF DAYTIME HEATING TNGT WL CAUSE THE
CHARACTER OF THE SHOWER PATTERN TO TRANSITIONS FM ONE THAT SUPPORTS
THE HIER POPS OVER THE INTERIOR THIS AFTN TO A MORE WINTRY LES
LOOK TNGT. IN FACT...THE NW FLOW IS PROGGED TO ADVECT H85 TEMPS AS
LO AS -13 TO -14C OVER THE KEWEENAW BY 12Z WED...TEMPS LO ENUF TO
SUPPORT LES AND INCRS SN/WATER RATIOS ONCE THE EFFECT OF DAYTIME
INSOLATION HAS FADED. OVER THE HIER TERRAIN OF THE W...THERE WL
LIKELY BE SEVERAL INCHES OF WET SN ACCUM TNGT INTO WED MRNG EVEN IN
THE ABSENCE OF SGNFT LARGER SCALE FORCING. OPTED TO ISSUE AN SPS
TO ALERT THE PUBLIC TO THE POTENTIAL OF SOME SLUSHY SN ACCUMS ON
ROADS LATER THIS EVNG INTO WED MRNG. DAYTIME HEATING ON WED WL
BRING ABOUT A RETURN TO A MORE LAND BASED INSTABILITY SHOWER
PATTERN. BUT SOMEWHAT HIER HGTS/SHARPENING MID LVL INVRN FARTHER FM
THE SLOWLY DEPARTING CLOSED LO THAT RESTRICTS DESTABILIZATION WL
TEND TO LIMIT COVERAGE/INTENSITY OF THE SHOWERS AS COMPARED TO TODAY.
ALTHOUGH H85 TEMPS ARE FCST TO MODERATE TO -10C TO -12C...MAX TEMPS
ON WED WL HOLD IN THE 30S EXPECT WHERE SOME DOWNSLOPE WARMING AIDS
DIURNAL TEMP RECOVERY INTO THE LO 40S OVER THE SCENTRAL. THERE COULD
BE SOME RECORD LO MAX TEMPS ON WED.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 302 AM EDT WED APR 22 2015
NAM SHOWS A TROUGH OVER THE EASTERN U.S. 12Z THU WITH MORE TROUGHING
ACROSS THE WEST COAST AND A SHORTWAVE RIDGE OVER THE PLAINS. NAM
SHOWS SOME WEAK 850-500 MB Q-VECTOR CONVERGENCE MOVING THROUGH THE
CWA ON THU WITH MOISTURE MOVING OUT IN THE AFTERNOON. AS THE
SHORTWAVE RIDGE MOVES TOWARDS THE AREA AND A TROUGH OVER THE EASTERN
U.S. MOVES AWAY...THE WRAPAROUND LAKE ENHANCED PCPN WILL SLOWLY WIND
DOWN AND HAVE IT DRYING OUT FRI AND FRI NIGHT WITH SLOWLY
DIMINISHING POPS IN THE CENTRAL AND EAST ON THU INTO THU NIGHT.
OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES OR POPS.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB LOW OVER THE CENTRAL
PLAINS 12Z SAT WITH MORE TROUGHING IN THE WESTERN U.S. THE 500 MB
LOW AND TROUGH IN THE CENTRAL PLAINS GETS SHEARED OUT BY 12Z SUN AND
IS REPLACED BY A SHORTWAVE RIDGE THAT MOVES INTO THE UPPER GREAT
LAKES. THE RIDGE REMAINS OVER THE UPPER GREAT LAKES ON MON WITH
TROUGHING MOVING INTO THE NORTHERN PLAINS. THIS TROUGHING MOVES INTO
THE UPPER GREAT LAKES 12Z TUE. TEMPERATURES WILL STAY BELOW NORMAL
THIS FORECAST PERIOD. WILL CONTINUE WITH DRY WEATHER SAT THROUGH SUN
NIGHT AND THEN GO WITH SLIGHT CHANCE POPS MON THROUGH TUE AS A SFC
FRONT IS WELL OFF TO THE WEST AT THAT TIME AND PRODUCES SOME OVER
RUNNING PCPN THAT IS OFF TO THE WEST MOSTLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1231 AM EDT WED APR 22 2015
AS DEEP MOISTURE LINGERS AND COLDER AIR ARRIVES OVERNIGHT...SHSN
WILL INCREASE IN FREQUENCY AND INTENSITY AT KIWD/KCMX UNDER USPLOPE
NW WIND OFF LAKE SUPERIOR. EXPECT PREVAILING IFR CONDITIONS AT BOTH
TERMINALS THRU MID MORNING. TYPICAL FOR SHSN...THERE WILL BE
FLUCTUATION WITH SOME BRIEF PERIODS OF LIFR AND MVFR...THOUGH LIFR
MAY BE MORE FREQUENT IN THE FEW HRS EITHER SIDE OF SUNRISE. INTO THE
AFTN...EXPECT IMPROVEMENT TO MVFR AS SHSN INTENSITY DIMINISHES.
DOWNSLOPE NATURE OF THE NW FLOW WILL WORK TO LIMIT THE POTENTIAL FOR
LOWER VIS/CIG AT KSAW. WHILE MVFR CONDITIONS SHOULD PREVAIL...THERE
MAY BE BRIEF PERIODS OF IFR THRU MID MORNING. MVFR CONDITIONS WILL
PERSIST AT ALL TERMINALS THRU THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 305 PM EDT TUE APR 21 2015
NORTHWESTERLY WINDS UP TO 30 KNOTS WILL CONTINUE OVER LAKE SUPERIOR
THROUGH THURSDAY MORNING. THERE COULD BE A FEW PERIODS OF GALE
FORCE GUSTS TO 35KTS LATE TONIGHT INTO WEDNESDAY...BUT THEY
SHOULDN/T BE WIDESPREAD. HIGH PRESSURE WILL BEGIN TO BUILD INTO
WESTERN LAKE SUPERIOR THURSDAY AFTERNOON/NIGHT AND LEAD TO
GRADUALLY DIMINISHING WINDS INTO FRIDAY. LIGHT NORTHERLY WINDS UP
TO 15KTS ARE EXPECTED THIS WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL NOON EDT /11 AM CDT/ TODAY FOR
MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...KC
LONG TERM...07
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1232 AM EDT WED APR 22 2015
.UPDATE...
ISSUED AT 1114 PM EDT TUE APR 21 2015
PREVIOUS SHORT TERM DISCUSSION SPELLED OUT THE SITUATION QUITE WELL
FOR OVERNIGHT INTO WED. AFTER CONSIDERING THE DEEP MOISTURE ON 00Z
KINL/CWPL SOUNDINGS...850MB TEMPS FALLING AT LEAST ANOTHER 2C
OVERNIGHT AND CONTINUED CYCLONIC FLOW...FEEL ADVY ACCUMULATIONS ARE
LIKELY TO OCCUR OVER A DECENT AREA OF GOGEBIC/ONTONAGON COUNTIES...
IN PARTICULAR THE HIGH TERRAIN. WOULD NOT BE SURPRISED TO SEE A FEW
SPOTS IN THE HIGH TERRAIN TOP 5 INCHES BY NOON WED. PROBABLY COULD
HAVE EXTENDED ADVY N AND E THRU THE KEWEENAW AND INTO BARAGA COUNTY
AS AIR MASS PASSING OVER THE LAKE WILL BE A LITTLE COLDER THAN DOWN
TOWARD KIWD. RECENT RADAR TRENDS ARE ALSO A CONCERN WITH INCREASING
COVERAGE AND INTENSITY OF SNOW IN THAT AREA. ALSO BUMPED UP SNOW
ACCUMLATIONS INTO THE ERN FCST AREA...E OF MARQUETTE AS 850MB
THERMAL TROF WITH TEMPS AS LOW AS -14C WILL BE AIMING SE ACROSS THE
LAKE AND INTO THAT AREA WED MORNING. HAVE AMOUNTS UP TO AROUND 3
INCHES IN THAT AREA BY LATE WED MORNING...BUT THAT COULD END UP
BEING TOO CONSERVATIVE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 352 PM EDT TUE APR 21 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO OVER
THE UPR LKS DOWNSTREAM OF HI AMPLITUDE UPR RDG OVER WRN NAMERICA.
COMBINATION OF DEEP CYC FLOW W TO NW FLOW AND INSTABILITY ENHANCED
BY DAYTIME HEATING UNDER ACCOMAPANYING THERMAL TROF /12Z H5 TEMP AT
GRB WAS -31C/ AND DEEP MSTR SHOWN ON THE 12Z RAOBS IS RESULTING IN
SCT-NMRS SN SHOWERS THAT ARE MIXED WITH RA IN THE WARMER LOCATIONS.
BUT COLDER CLD TOP TEMPS/MORE WIDESRPEAD SN SHOWERS ARE CONFINED
MAINLY TO NW ONTARIO/FAR NRN MN IN AREA WHERE MODELS INDICATE DEEP
QVECTOR CNVGC.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS AND POTENTIAL SN
ACCUMS ASSOCIATED WITH DEEP CYC...MOIST NW FLOW ARND SLOW MOVING
CLOSED LO TO THE NE OF UPR MI.
CLOSED LO CENTERED OVER ERN LK SUP THIS AFTN IS FCST TO DRIFT SLOWLY
TO THE NE AND TO JUST S OF JAMES BAY ON WED. ALTHOUGH ACCOMPANYING
DEEP LYR QVECTOR CNVGC THAT IS SUPPORTING COLDER CLD TOPS TO THE NW
IS FCST TO REMAIN TO THE N OF UPR MI...PERSISTENT MOIST...CYC NW
FLOW ARND THIS FEATURE WL MAINTAIN AT LEAST CHC POPS OVER THE CWA
THRU WED...WITH THE LOWER POPS GENERALLY OVER THE SCENTRAL AND THE
HIER POPS OVER THE HIER TERRAIN OF THE NW WITH UPSLOPE WIND
COMPONENT. BUT LOSS OF DAYTIME HEATING TNGT WL CAUSE THE
CHARACTER OF THE SHOWER PATTERN TO TRANSITIONS FM ONE THAT SUPPORTS
THE HIER POPS OVER THE INTERIOR THIS AFTN TO A MORE WINTRY LES
LOOK TNGT. IN FACT...THE NW FLOW IS PROGGED TO ADVECT H85 TEMPS AS
LO AS -13 TO -14C OVER THE KEWEENAW BY 12Z WED...TEMPS LO ENUF TO
SUPPORT LES AND INCRS SN/WATER RATIOS ONCE THE EFFECT OF DAYTIME
INSOLATION HAS FADED. OVER THE HIER TERRAIN OF THE W...THERE WL
LIKELY BE SEVERAL INCHES OF WET SN ACCUM TNGT INTO WED MRNG EVEN IN
THE ABSENCE OF SGNFT LARGER SCALE FORCING. OPTED TO ISSUE AN SPS
TO ALERT THE PUBLIC TO THE POTENTIAL OF SOME SLUSHY SN ACCUMS ON
ROADS LATER THIS EVNG INTO WED MRNG. DAYTIME HEATING ON WED WL
BRING ABOUT A RETURN TO A MORE LAND BASED INSTABILITY SHOWER
PATTERN. BUT SOMEWHAT HIER HGTS/SHARPENING MID LVL INVRN FARTHER FM
THE SLOWLY DEPARTING CLOSED LO THAT RESTRICTS DESTABILIZATION WL
TEND TO LIMIT COVERAGE/INTENSITY OF THE SHOWERS AS COMPARED TO TODAY.
ALTHOUGH H85 TEMPS ARE FCST TO MODERATE TO -10C TO -12C...MAX TEMPS
ON WED WL HOLD IN THE 30S EXPECT WHERE SOME DOWNSLOPE WARMING AIDS
DIURNAL TEMP RECOVERY INTO THE LO 40S OVER THE SCENTRAL. THERE COULD
BE SOME RECORD LO MAX TEMPS ON WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 PM EDT TUE APR 21 2015
THE UPPER LOW THAT IS CURRENTLY AFFECTING THE AREA WILL SHIFT EAST
INTO THE CANADIAN MARITIMES SHORTLY AFTER THE START OF THE LONG TERM
PERIOD. THIS WILL LEAVE THE AREA BETWEEN THAT UPPER LOW AND AN UPPER
RIDGE IN THE CENTRAL/SOUTHERN PLAINS. THUS...THE AREA WILL BE UNDER
NORTHWESTERLY FLOW ALOFT FOR MOST DAYS THROUGH THE UPCOMING WEEKEND.
WITH A SURFACE RIDGE STRETCHING SOUTH FROM A HIGH IN NORTHERN CANADA
MOVING INTO THE AREA BY FRIDAY AND FRIDAY NIGHT...EXPECT DRIER AIR
TO GRADUALLY MOVE INTO THE REGION AND DIMINISH THE PRECIPITATION
POTENTIAL AND LEAD TO A DRY WEEKEND (ALTHOUGH THERE ARE HINTS OF A
WEAK DISTURBANCE BRINGING AN ISOLATED SHOWER TO THE FAR WESTERN U.P.
LATE FRIDAY NIGHT INTO SATURDAY MORNING). WITH THE MAIN UPPER LOW
SHIFTING EAST...TEMPERATURES WILL SLOWLY WARM BUT STILL STAY BELOW
NORMAL FOR LATE APRIL (AIDED BY THE LIGHT NORTHERLY FLOW OFF LAKE
SUPERIOR).
HEADING INTO NEXT WEEK...THE UPPER LOW CURRENTLY OVER THE GULF OF
ALASKA WILL MOVE INTO THE PACIFIC NORTHWEST OVER THE NEXT 24-48HRS
AND THEN INTO THE CENTRAL CONUS ON MONDAY. AS THE WAVE CONTINUES
EAST...IT WILL INTERACT WITH THE UPPER LOW NEAR THE CANADIAN
MARITIMES AND RE-ESTABLISH THE UPPER TROUGH OVER THE EASTERN CONUS.
THIS WILL KEEP BELOW NORMAL TEMPERATURES IN PLACE INTO NEXT WEEK AND
POSSIBLY LEAD TO SOME SHOWERS AROUND THE GREAT LAKES REGION.
OVERALL...FAIRLY COOL AND QUIET END TO APRIL WITH NO HAZARDOUS
WEATHER EXPECTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1231 AM EDT WED APR 22 2015
AS DEEP MOISTURE LINGERS AND COLDER AIR ARRIVES OVERNIGHT...SHSN
WILL INCREASE IN FREQUENCY AND INTENSITY AT KIWD/KCMX UNDER USPLOPE
NW WIND OFF LAKE SUPERIOR. EXPECT PREVAILING IFR CONDITIONS AT BOTH
TERMINALS THRU MID MORNING. TYPICAL FOR SHSN...THERE WILL BE
FLUCTUATION WITH SOME BRIEF PERIODS OF LIFR AND MVFR...THOUGH LIFR
MAY BE MORE FREQUENT IN THE FEW HRS EITHER SIDE OF SUNRISE. INTO THE
AFTN...EXPECT IMPROVEMENT TO MVFR AS SHSN INTENSITY DIMINISHES.
DOWNSLOPE NATURE OF THE NW FLOW WILL WORK TO LIMIT THE POTENTIAL FOR
LOWER VIS/CIG AT KSAW. WHILE MVFR CONDITIONS SHOULD PREVAIL...THERE
MAY BE BRIEF PERIODS OF IFR THRU MID MORNING. MVFR CONDITIONS WILL
PERSIST AT ALL TERMINALS THRU THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 305 PM EDT TUE APR 21 2015
NORTHWESTERLY WINDS UP TO 30 KNOTS WILL CONTINUE OVER LAKE SUPERIOR
THROUGH THURSDAY MORNING. THERE COULD BE A FEW PERIODS OF GALE
FORCE GUSTS TO 35KTS LATE TONIGHT INTO WEDNESDAY...BUT THEY
SHOULDN/T BE WIDESPREAD. HIGH PRESSURE WILL BEGIN TO BUILD INTO
WESTERN LAKE SUPERIOR THURSDAY AFTERNOON/NIGHT AND LEAD TO
GRADUALLY DIMINISHING WINDS INTO FRIDAY. LIGHT NORTHERLY WINDS UP
TO 15KTS ARE EXPECTED THIS WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL NOON EDT /11 AM CDT/ TODAY FOR
MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
402 AM CDT WED APR 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM CDT WED APR 22 2015
ELONGATED HIGH PRESSURE FROM CANADA TO THE
MISSOURI BASIN DRIFTS EAST TODAY SETTING UP A COOL SOUTHERLY RETURN
FLOW FROM KANSAS. THE RAP MODEL INDICATES A WARM FRONT WILL DEVELOP
ACROSS WRN NEB WHICH MOVES EAST THIS AFTERNOON AND TONIGHT. THE
MODEL SUGGESTS A NARROW MIDLEVEL CLOUD SHIELD WILL DEVELOP NEAR
VALENTINE TONIGHT WHICH IS WELL SUPPORTED BY THE GFS...LESS SO BY
THE OTHER MODELS. THE OBVIOUS CULPRIT IS 700MB FRONTOGENESIS AND THE
DEVELOPING WARM FRONT. THE FORECAST IS FOR PARTLY CLOUDY SKIES TODAY
AND TONIGHT WITH TEMPERATURES RISING INTO THE 50S AND 60S. LOWS
TONIGHT FALL INTO THE 30S TO NEAR FREEZING EAST OF HIGHWAY 83.
MOISTURE WILL RETURN LATE TONIGHT ACROSS SWRN NEB. THE MODEL
SOUNDINGS SUGGESTS A SUNRISE SPECIAL THURSDAY MORNING WITH STRATUS
DEVELOPING WITH THE ONSET OF MIXING AFTER SUNRISE. A SLIGHT DELAY OF
3 HOURS IN THE MOISTURE RETURN WOULD RESULT IN SUFFICIENT HEATING
AND MIXING TO PRECLUDE CLOUD DEVELOPMENT. MEANWHILE...IF THE MODELS
ARE TOO SLOW THEN CLOUDS COULD FORM BEFORE SUNRISE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 348 AM CDT WED APR 22 2015
LONG WAVE TROUGH WILL BE MOVING ONSHORE THE WEST COAST
THURSDAY...WITH FLOW ALOFT BECOMING SOUTHWEST AHEAD OF THE TROUGH
ACROSS THE CENTRAL PLAINS. ONE DISTURBANCE WILL EJECT NORTHEAST FROM
THE TROUGH THURSDAY NIGHT INTO FRIDAY. MODELS ARE WEAKER WITH THIS
FEATURE COMPARED TO A COUPLE OF DAYS AGO...AND HAVE PUT THE BREAKS
ON THE POPS. WILL LEAVE IN THE CHANCE CATEGORY FOR THE MOST PART.
LIFT IS MARGINAL AND NOT ORGANIZED IN ANY ONE AREA...SO THINKING A
MORE SHOWERY TYPE RAIN WILL OCCUR. ACTUALLY KIND OF HARD TO PIN DOWN
EXACTLY WHERE...BUT THE BETTER CHANCE WOULD LIKELY BE AFTER MIDNIGHT
THURSDAY NIGHT INTO FRIDAY MORNING ON THE NOSE OF A SOUTHERLY LOW
LEVEL JET ACROSS CENTRAL INTO EASTERN NEBRASKA. THEN LATER IN THE
DAY ACROSS THE WESTERN HIGH PLAINS OF NEBRASKA INTO EASTERN
COLORADO...AS CONDITIONS BECOME SOMEWHAT UNSTABLE LEADING TO A
SCATTERING OF THUNDERSTORMS. THESE STORMS WILL BE AIDED BY THE
ACTUAL DISTURBANCE CROSSING THE AREA DURING PEAK HEATING. THESE
STORMS WILL WEAKEN SOMEWHAT AS THEY MOVE EAST...BUT DO EXPECT AT
LEAST SHOWERS TO MOVE ACROSS THE AREA FRIDAY NIGHT. AGAIN...DOESN/T
APPEAR TO BE REAL ORGANIZED...AND CAN/T JUSTIFY LIKELY POPS AT ANY
ONE LOCATION AT THIS TIME.
FOR THE WEEKEND INTO EARLY NEXT WEEK...IT LOOKS RATHER INTERESTING.
THE LONG WAVE TROUGH MOVES INTO THE ROCKIES BY SUNDAY. SATURDAY
LOOKING TO BE A FAIRLY DRY DAY AS RIDGING DEVELOPS ACROSS THE
CENTRAL PLAINS AHEAD OF THE TROUGH. TRIED TO LIMIT POPS TO JUST A
SLIGHT CHANCE FOR THIS REASON SATURDAY. BY SUNDAY NIGHT INTO
MONDAY...THE MODELS DIG THE TROUGH INTO THE FOUR CORNERS WHERE IT
SHOULD CLOSE OFF. VERY GOOD AGREEMENT AMONG THE GFS ENSEMBLE
MEMBERS ON THIS OCCURRING...AND BOTH THE OPERATIONAL GFS AND ECMWF
INDICATE THIS SCENARIO AS WELL. HOWEVER...THE ECMWF CONTINUES TO
DIG THE SYSTEM SOUTH INTO TEXAS LEAVING US WITH LITTLE
PRECIPITATION. THE GFS AND GFS ENSEMBLE MEAN ON THE OTHER HAND ARE
FARTHER NORTH...AND HAVE A CLOSED H700MB LOW CENTER IN SOUTHEAST
COLORADO SUNDAY NIGHT. ALSO THEY HAVE HEAVY RAINFALL SUNDAY NIGHT
INTO MONDAY FROM NORTHWEST KANSAS...NORTH AND WEST ACROSS
NORTHEAST COLORADO...SOUTHWEST NEBRASKA AND THE SOUTHERN NEBRASKA
PANHANDLE. OVERALL THIS STRONG CLOSED SYSTEM IS A NEW DEVELOPMENT
IN THE MODELS/ENSEMBLE TONIGHT...AND WON/T GET CARRIED AWAY WITH
RAIN CHANCES JUST YET. ALSO TONIGHT/S SOLUTIONS ARE A BIT
SLOWER...SO THE HIGHER CHANCES FOR RAIN CURRENTLY IN THE FORECAST
FOR SUNDAY MAY HAVE TO BE EXTENDED INTO SUNDAY NIGHT AND MONDAY.
WILL CONTINUE TO MONITOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1146 PM CDT TUE APR 21 2015
EXPECT CLEAR SKIES ACROSS WESTERN AND NORTH CENTRAL NEBRASKA OVER
THE NEXT 24 HOURS. THE EXCEPTION WILL BE AT THE KLBF TERMINAL
DURING THE AFTERNOON HOURS ON WEDNESDAY AS SOME SCATTERED CLOUDS
AROUND 10000 FT AGL ARE POSSIBLE. WINDS WILL BECOME SOUTHERLY WEDS
MORNING AND INCREASE TO 10 TO 15 KTS DURING THE AFTERNOON HOURS.
WINDS WILL BECOME EASTERLY WEDS EVENING AND DIMINISH TO UNDER 10
KTS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
328 AM EDT WED APR 22 2015
.SYNOPSIS...
A BROAD AREA OF LOW PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER
OVER THE GREAT LAKES THROUGH THE END OF THE WEEK. THIS WILL SUPPORT
BELOW NORMAL TEMPERATURES AND THE CHANCE FOR SOME ON AND OFF RAIN
SHOWERS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LOW REMAINS IN PLACE ACROSS THE ONTARIO/QUEBEC REGION. AT
THE SURFACE A COLD FRONT CONTINUES TO MOVE THROUGH THE AREA
SPREADING RAIN SHOWERS INVOF THE FRONT. THE FRONT WILL CONTINUE
SOUTHEAST TODAY AND SHOULD BE MOVING EAST OF THE AREA EARLY THIS
MORNING. EXPECTING SHOWERS TO CONTINUE MOST AREAS THROUGH THE
PREDAWN HOURS. AFTER DAWN SHOWERS SHOULD AFFECT MAINLY SOUTHERN
AND EASTERN COUNTIES WITH THE MAIN AREA OF RAIN SOUTHEAST BY
14-15Z. HRRR DOES SHOW SOME REDEVELOPMENT EASTERN HALF OF THE AREA
LATE MORNING SO WILL HOLD ONTO POPS THERE. THERE ARE SOME BREAKS
IN THE CLOUDS MAINLY ACROSS NWRN OHIO AND SRN LWR MI BUT THROUGH
THE MORNING THIS SHOULD FILL IN WITH SUCH COLD AIR ALOFT AND
ADDITIONAL WRAP AROUND MOISTURE DROPPING ACROSS THE AREA IN THE
AFTERNOON. HIGHS TODAY WILL LIKELY NOT RISE TOO MUCH FROM MORNING
LOWS GIVEN THE COLD ADVECTION ACROSS THE AREA. RISES LIKELY ON THE
ORDER OF 5 DEGREES OR SO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
THE NAM SHOWS NO BIG CHANGES IN STORE FOR NRN OHIO AND NWRN PA
THROUGH THURSDAY AT LEAST WITH PLENTY OF MOISTURE ROTATING ACROSS
THE AREA AROUND THE CLOSED STAGNANT UPPER LOW. THE CIRCULATION
SHIFTS EAST ENOUGH BY FRIDAY TO GET DRIER AIR INTO THE AREA BUT
STILL NO WARM UP WITH 850MB TEMPS BELOW ZERO AND WELL BELOW NORMAL.
SATURDAY MOISTURE WILL RETURN AS LOW PRESSURE MOVES EAST ACROSS
THE LOWER OHIO VALLEY. DEPENDING ON THE PATH WE COULD GET SHOWERS
ASSOCIATED WITH THE LOW INTO THE AREA SO DID PUT IN A CHANCE POP
WESTERN TWO THIRDS.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE FORECAST PERIOD.
BOTH MODELS CONTINUE IN GOOD AGREEMENT WITH HIGH PRESSURE PUSHING
SOUTHEAST ACROSS THE AREA ON SUNDAY. HIGH REMAINS ENTRENCHED OVER
THE FORECAST AREA MONDAY AS LOW PRESSURE TRACKS UP THE EAST COAST.
MODELS DIVERGE ON TUESDAY AS GFS MOVES LOW PRESSURE SYSTEM ACROSS
THE UPPER OHIO VALLEY WHILE ECMWF CONTINUES WITH HIGH PRESSURE OVER
THE AREA. WILL CONTINUE WITH PREVIOUS FORECAST WHICH TRENDED TOWARD
GFS WITH LOW CHANCE POPS.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
SCATTERED SHOWERS WILL CONTINUE OVERNIGHT WITH A WEAK SHORT WAVE
WILL MOVE ACROSS THE OHIO VALLEY. MAY GET SOME MVFR CONDITIONS IN
THE HEAVIER SHOWERS. WINDY CONDITIONS WILL CONTINUE TODAY...LUCKILY
IT WILL NOT BE AS WINDY AS TUESDAY...MORE LIKE 20-30 KNOT GUSTS
FROM THE WEST.
.OUTLOOK...MVFR CEILINGS AT TIMES THURSDAY MAINLY EXTREME NORTHEAST
OH AND NORTHWEST PA.
&&
.MARINE...
SMALL CRAFT ADVISORY WILL CONTINUE INTO THURSDAY NIGHT. GUSTY WEST
TO SOUTHWEST WINDS WILL CONTINUE INTO THURSDAY NIGHT AS LOW PRESSURE
SLOWLY DRIFTS ACROSS EASTERN CANADA. WINDS WILL BECOME LIGHTER BY
FRIDAY AND FRIDAY NIGHT AS HIGH PRESSURE BUILDS SLOWLY OVER THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THURSDAY FOR LEZ142>146.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS TULSA OK
1112 PM CDT TUE APR 21 2015
.DISCUSSION...
THE 06Z TAF DISCUSSION IS INCLUDED BELOW.
&&
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
THE 00Z SUITE OF DATA WAS NOT AS PESSIMISTIC OVERALL WITH REGARD
TO LOWER CIGS. BASED ON HRRR DATA...A COMPLEX OF STORMS WILL
ORGANIZE AHEAD OF SURGING FRONT AND WILL AFFECT MOST SITES EARLY
WEDNESDAY MORNING. A PERIOD OF MVFR CONDITIONS IS POSSIBLE WITH
THE ACTIVITY...OTHERWISE VFR CIGS WILL PREVAIL. SOME CHANCE OF
SHRA AND TSRA WILL PERSIST THRU THE END OF THE FCST PD...AND HAVE
CHOSEN TO HANDLE THIS WITH PROB30 GROUPS.
LACY
&&
.PREV DISCUSSION... /ISSUED 954 PM CDT TUE APR 21 2015/
DISCUSSION...
MINOR WAVE NORTH TEXAS AND OKLAHOMA PANHANDLE REGION
JUST STARTING TO PRODUCE LIGHTNING. 00Z WRF ALONG WITH
THE LAST SEVERAL HOURLY RUNS OF HR^3 GROW CONVECTION
OVERNIGHT TO WEST AND PUSH IT THROUGH EASTERN OKLAHOMA
VERY LATE TONIGHT AND WEDNESDAY MORNING. RAISED POPS
FOR WEDNESDAY MORNING. LEFT OVER BOUNDARIES MAY BECOME
FOCUS OF MORE SIGNIFICANT THUNDER WEDNESDAY AFTERNOON
AND EVENING. STILL LOOKS LIKE BEST BET NEAR RED RIVER.
GW
PREV DISCUSSION... /ISSUED 608 PM CDT TUE APR 21 2015/
DISCUSSION...
THE 00Z TAF DISCUSSION IS INCLUDED BELOW.
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
VFR CONDITIONS WILL PREVAIL THRU MUCH OF THE NIGHT TONIGHT...THRU
ABOUT 09Z. MVFR CIGS ARE EXPTD AT THE TAF SITES IN THE 09Z TO 12Z
TIME FRAME. SOME SCT SHRA OR TSRA ARE POSSIBLE AS A FRONTAL
BOUNDARY DROPS DOWN INTO THE REGION. CONDITIONS SHOULD IMPROVE BY
MIDDAY WEDNESDAY AT MOST SITES...WITH THE EXCEPTION OF
KMLC...WHICH IS FORECAST TO REMAIN MVFR THRU THE DAY.
LACY
PREV DISCUSSION... /ISSUED 254 PM CDT TUE APR 21 2015/
DISCUSSION...
CENTRAL PLAINS FRONT WILL DROP SOUTH TONIGHT...SETTLING TO NEAR THE
OK/TX BORDER BY WEDNESDAY MORNING. LOW-LEVEL MOISTURE WILL IMPROVE
THROUGH THE NIGHT...WITH LOWER 60S DEWPOINTS LIKELY ACROSS SE OK BY
WEDNESDAY MORNING. A MARGINAL SEVERE WEATHER THREAT WILL EXIST EARLY
WEDNESDAY...AS ELEVATED STORMS NORTH OF THE FRONTAL BOUNDARY WILL
POSE A HAIL THREAT. SOME OF THIS ACTIVITY MAY FESTER INTO THE
AFTERNOON...WITH THE SEVERE WEATHER CHANCES RISING A BIT AS
INSTABILITY INCREASES. ADDITIONAL THUNDERSTORMS MAY FIRE ALONG THE
DRYLINE OVER WRN TX LATE IN THE DAY...WITH THUNDERSTORM CLUSTERS
WORKING E AND SE OVERNIGHT ACROSS PARTS OF SRN OK/NRN TX. OVERALL
SEVERE WEATHER THREAT MAINLY BE FOR LARGE HAIL AND DAMAGING
WINDS...ALTHOUGH A LOW-END TORNADO THREAT WILL EXIST (FROM LATE
AFTERNOON INTO THE EARLY EVENING) FOR STORMS NEAR THE SYNOPTIC
BOUNDARY AND VARIOUS OUTFLOW BOUNDARIES.
SURFACE RIDGING ALONG WITH A MORE STABLE AIRMASS SHOULD KEEP
THURSDAY FAIRLY QUIET...ALTHOUGH HAVE KEPT SOME LOW POPS FOR A FEW
SHOWERS AND PERHAPS A THUNDERSTORM.
SEVERE WEATHER CHANCES...POTENTIALLY SIGNIFICANT AT THAT...RETURN BY
FRIDAY. ECMWF/GFS SIMILAR IN EJECTING AN UPPER CYCLONE INTO THE
CENTRAL PLAINS...WITH A STRONG 75+ KT MID-LEVEL JET SETTING UP
ACROSS THE SRN PLAINS. FORECAST LOW-LEVEL MOISTURE FIELDS SHOW
DRYLINE SURGING INTO CENTRAL OK BY FRIDAY AFTERNOON...WITH
CONVECTION PEELING OFF INTO ERN OK/WRN AR LATE IN THE DAY AND INTO
FRIDAY EVENING. MAIN COMPLICATING FACTOR WILL THE QUALITY OF
MOISTURE/INSTABILITY AS ECMWF/GFS ALSO SHOW SIGNIFICANT QPF EARLY IN
THE DAY ACROSS NRN TX. THIS COULD HAVE A HUGE IMPACT ON WHERE THE
WARM SECTOR SETS UP DURING THE AFTERNOON...AND THE POTENTIAL EXISTS
(IF ECMWF/GFS QPF VERIFIES) THAT THE WARM SECTOR MOSTLY REMAINS TO
OUR SOUTH. THIS IS STILL A FEW DAYS AWAY AND WE`LL CONTINUE TO TWEAK
THE FORECAST SO PLEASE STAY TUNED.
THE WEEKEND IS LOOKING MOSTLY DRY...WITH PRECIPITATION CHANCES
RETURNING BY SUNDAY NIGHT AND INTO EARLY NEXT WEEK AS ANOTHER UPPER
SYSTEM APPROACHES. EXTENDED MODELS ARE SHOWING VARYING TIMING
DIFFERENCE...SO HAVE KEPT POPS RATHER LOW AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 51 66 51 68 / 30 60 40 40
FSM 51 73 56 67 / 10 60 40 30
MLC 53 74 57 71 / 10 60 40 30
BVO 48 65 45 66 / 30 30 20 30
FYV 48 67 49 62 / 20 60 30 30
BYV 50 63 45 59 / 20 30 20 30
MKO 49 71 52 68 / 20 60 40 30
MIO 48 65 45 64 / 30 30 20 40
F10 54 71 54 69 / 20 70 40 30
HHW 53 75 60 73 / 10 70 60 30
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...30
AREA FORECAST DISCUSSION...UPDATED
NWS MEDFORD OR
1124 PM PDT TUE APR 21 2015
.UPDATE...THE ATMOSPHERE IS STABILIZING AND THE LATEST SHORT TERM
FORECAST SHOW LESS CONVECTION POTENTIAL. THEREFOR WE HAVE REMOVED
THUNDERSTORMS IN THE FORECAST FOR THE SECOND HALF OF TONIGHT. THE
SHOWERS WILL CONTINUE TO MOVE EAST AND AREAS FROM GERBER RESERVOIR
SOUTH INTO MEDICINE LAKE OF EASTERN SISKIYOU COUNTY SHOULD SEE
MOST OF THE MODERATE SHOWERS OVERNIGHT...WITH SHOWER COVERAGE
DECREASING TO ISOLATED OVERNIGHT. /FB
&&
.AVIATION...FOR THE 22/06Z TAF CYCLE...ALONG THE COAST NORTH OF
PORT ORFORD, MVFR CIGS WILL GRADUALLY LIFT TO VFR LATER WEDNESDAY
MORNING OR AFTERNOON. OFFSHORE FLOW WILL RESULT IN VFR ALONG THE
SOUTH COAST THROUGH WEDNESDAY.
THE REST OF THE WEST SIDE TO THE CASCADES WILL BE MOSTLY VFR
THOUGH AREAS OF MVFR AND PARTIAL TERRAIN OBSCURATIONS WILL DEVELOP
AND LAST THROUGH ABOUT MID-LATE MORNING WEDNESDAY. NORTH TO
NORTHWEST CAN BE BREEZY AT TIMES ESPECIALLY IN THE KLAMATH BASIN
AND THE SHASTA VALLEY WHERE SUSTAINED WIND 15 TO 20 KNOTS ARE
EXPECTED WEDNESDAY AFTERNOON. /FB
&&
.PREV DISCUSSION... /ISSUED 847 PM PDT TUE APR 21 2015/
DISCUSSION...THUNDERSTORMS ARE RUMBLING ACROSS SOUTHEAST SISKIYOU
COUNTY FROM MOUNT SHASTA EASTWARD. RADAR AND SATELLITE IMAGERY
SHOW THREE MORE CELLS ONE OF WHICH LOOKS POTENT ARE APPROACHING
THIS AREA FROM SHASTA COUNTY. SOUTHERN SISKIYOU COUNTY AND
NORTHERN KLAMATH COUNTY WERE THE AREAS THAT MODELS PAINTED THE
MOST INSTABILITY SO CONFIDENCE IS HIGH AS WE MOVE FORWARD INTO THE
REST OF THE NIGHT FORECAST TIMEFRAME. THE SHORT TERM HRRR TAKES
THIS UNSTABLE AREA EAST AND BY MIDNIGHT THE AREA OF CONCERNS SHIFT
TO LAKE COUNTY..ESPECIALLY THE LINE ROUGHLY FOLLOWING HIGHWAY 395
FROM LAKE-HARNEY COUNTY LINE SOUTH INTO MODOC COUNTY...WITH THE
WARNERS SEEING MOST OF THE ACTIVITIES AFTER MIDNIGHT. WE HAVE
UPDATED THE POPS AND WEATHER GRIDS TO INDICATE THIS TREND AND
GRIDS HAVE BEEN POSTED. SO FAR THESE STORMS HAVE PRODUCED RAINFALL
BETWEEN 0.15-0.25 INCH WITH ONE AREA NEAR MCCLOUD RECEIVING ALMOST
HALF AN INCH OF RAIN. /FB
.MARINE...UPDATED 800 PM PDT TUESDAY APR 21, 2015...HIGH PRESSURE
WILL BUILD INTO THE AREA TONIGHT BUT THIS WILL RESULT IN GUSTY
NORTH WINDS AND STEEP TO VERY STEEP SEAS. GALES AND WARNING LEVEL
SEAS ARE EXPECTED AT TIMES SOUTH OF CAPE BLANCO TONIGHT THROUGH
WEDNESDAY NIGHT. THURSDAY THROUGH THE WEEKEND...A SERIES OF
FRONTAL SYSTEMS IS LIKELY TO MOVE THROUGH WITH BUILDING SWELL.
NORTHWEST WINDS WEDNESDAY NIGHT THROUGH FRIDAY ARE EXPECTED TO
BECOME SOUTHWESTERLY THIS WEEKEND. FB
PREV DISCUSSION... /ISSUED 516 PM PDT TUE APR 21 2015/
SHORT TERM...VISIBLE SATELLITE SHOWS THE ATMOSPHERE HAS
DESTABILIZED AS EXPECTED WITH NUMEROUS CUMULUS BUILDUPS OVER THE
HIGHER TERRAIN AND EAST SIDE. RADAR IS ALREADY SHOWING RETURNS IN
EASTERN SISKIYOU, NORTHERN KLAMATH, AND CENTRAL LAKE COUNTIES.
THERE HAS EVEN BEEN A STRIKE OR TWO RECORDED IN EASTERN SISKIYOU
COUNTY JUST WEST OF TENANT. AND NUMEROUS STRIKES RECORDED JUST
SOUTH OF THE CWA IN LASSEN COUNTY. HI-RES, NEAR TERM MODELS LIKE
THE HRRR (HIGH RESOLUTION RAPID REFRESH) SHOW MOST OF THE ACTION
OVER MODOC, LAKE, AND FAR EASTERN KLAMATH COUNTIES LATER THIS
AFTERNOON. STEERING WINDS ARE FAIRLY LIGHT SO THESE STORMS WILL
LIKELY BE SLOW MOVERS RESULTING IN THE POTENTIAL FOR SOME HEAVIER
DOWNPOURS UNDER THE CORE OF THESE STORMS. ALSO EXPECT SOME GUSTY
OUTFLOW WINDS WITH THE STRONGER STORMS ALONG WITH THE POTENTIAL
FOR SMALL HAIL. MODELS CONTINUE TO SHOW THE ATMOSPHERE STABILIZING
WITH THE LOSS OF DIURNAL HEATING SO CONVECTION SHOULD DIMINISH BY
TONIGHT. THE ATMOSPHERE WEST OF THE CASCADES IS MORE STABLE WITH
WEAKER LAPSE RATES SO NOT EXPECTING ANY THUNDERSTORMS FOR THAT
AREA.
ASIDE FROM THE RAIN EXPECTED WITH THE CONVECTION PREVIOUSLY MENTIONED,
MOST AREAS WILL REMAIN DRY WITH THE PASSAGE OF THE COLD FRONT.
WINDS WILL BE QUITE BREEZY THROUGH THE AFTERNOON IN RESPONSE TO
THIS COLD FRONT MOVING THROUGH THE AREA. THE UPPER LEVEL TROUGH
MOVES THROUGH OVERNIGHT INTO TOMORROW AND DRIER, MORE STABLE AIR
MOVES IN BEHIND IT FOR WEDNESDAY. WEAK RIDGING STARTS TO BUILD
OVER THE AREA WEDNESDAY NIGHT, BUT THIS IS SHORT LIVED AS A WEAK
TROUGH APPROACHES THE AREA THURSDAY MORNING. THERE IS A CHANCE FOR
SOME SHOWERS THURSDAY AFTERNOON, BUT THIS LOOKS MOSTLY CONFINED
FROM THE UMPQUA DIVIDE AND NORTH.
AN UPPER LOW MOVES IN OVER BRITISH COLUMBIA THURSDAY EVENING AND
SHORTWAVES ROTATING AROUND IT CONTINUE THE CHANCE FOR PRECIPITATION
FOR MOST OF THE AREA THROUGH SATURDAY MORNING. MND
LONG TERM...SATURDAY THROUGH TUESDAY...THE OPERATIONAL EC AND
GFS ARE IN SIMILAR AGREEMENT WITH THE OVERALL PATTERN FRIDAY INTO
NEXT WEEKEND. HOWEVER THERE IS DISAGREEMENT WITH THE PLACEMENT AND
STRENGTH OF THE UPPER LOW FRIDAY. THE EC IS STRONGER AND FURTHER
SOUTH WITH THE UPPER LOW AND WETTER. HAVE KEPT IN A CHANCE OF
SHOWERS FOR MOST OF THE FORECAST AREA...THOUGH RAIN AND MOUNTAIN
SNOW AMOUNTS SHOULD BE LIGHT. THE TROUGH AXIS SHIFTS EAST FRIDAY
NIGHT AND RIDGING WILL ATTEMPT TO MOVE IN FROM THE SOUTHWEST. THE
GFS SHOWS MORE OF A DIRTY RIDGE SCENARIO WITH WARM FRONTAL
PRECIPITATION MOVING INTO THE AREA. THE EC HAS A MORE PRONOUNCED
RIDGE AND THUS SHOWS A DRY AND MILDER SOLUTION. SUSPECT THE WARM
FRONTAL PRECIPITATION IS OVERDONE, BUT DID NOT WANT TO DISCOUNT IT
COMPLETELY, SO WITH WITH A BLEND BETWEEN THE EC AND GFS WITH A
SLIGHTLY DRIER BIAS.
A DIRTY RIDGE REMAIN OVER THE AREA SUNDAY WITH THE BEST CHANCE FOR
PRECIPITATION OVER THE NORTHERN PART OF THE CWA. ESPECIALLY WEST OF
THE CASCADES AND NORTH OF THE UMPQUA DIVIDE.
SIGNIFICANT UPPER TROUGHING THAT`S BEEN HANGING OVER THE NORTHEAST
PACIFIC FINALLY REACHES THE FORECAST AREA WITH SIGNIFICANT RAIN
POTENTIALLY MONDAY INTO TUESDAY. THAT SAID...THERE IS SOME
UNCERTAINTY AS TO WHEN THIS TROUGHING REACHES THE AREA. ENSEMBLE
MEMBERS ARE OUT OF PHASE...BUT NOT AS MUCH AS YESTERDAY WITH THE
TROUGH AXIS STARTING TO DROP SOUTH. IN CONTRAST, THE OPERATIONAL EC
SHOWS MORE OF A SPLIT FLOW PATTERN NEAR 150 W AND MORE RIDGING IN
OUR AREA, THUS DELAYING ANY SIGNIFICANT PRECIPITATION.
IN SHORT...CONFIDENCE IS LOW TO MODERATE IN THE EXTENDED PERIOD AND
DID NOT MAKE ANY SIGNIFICANT CHANGES. -PETRUCELLI
.FIRE WEATHER...UPDATED 3 PM PDT TUESDAY, APRIL 21ST, 2015... THE
ATMOSPHERE IS ALREADY STARTING TO BECOME UNSTABLE AHEAD OF A
RATHER SHARP, BUT NOT STRONG, INCOMING TROUGH OF LOW PRESSURE. A
FEW ISOLATED STORMS HAVE DEVELOPED IN NORTHERN CAL AND NORTHERN
KLAMATH COUNTY NORTHEAST OF CHEMULT. THE LATEST HRRR REFLECTIVITY
PRODUCT SHOWS MOST OF THE ACTIVITY DEVELOPING IN NORTHERN CAL,
THEN MIGRATING NORTH INTO PARTS OF LAKE AND KLAMATH COUNTIES LATE
THIS AFTERNOON THROUGH THIS EVENING. UNLIKE THE HIGH IMPACT
LIGHTNING EVENTS THAT SOMETIMES AFFECT OUR REGION MAINLY IN THE
SUMMER, FORCING WITH THE INCOMING SYSTEM IS WEAK IN THAT THERE IS
NO CLEAR COLD POOL MOVING THROUGH. INSTEAD, A WEAK SURFACE FRONT
IS EXPECTED TO DEVELOP ALONG AND NEAR THE CASCADES THIS AFTERNOON.
THIS SHOULD GIVE RISE TO BUILD-UPS ALONG AND NEAR THE TRINITY ALPS
AND CASCADE CREST THIS AFTERNOON, SHIFTING EASTWARD TO THE LEE OF
THE CASCADES TOWARDS THE EVENING. CONDITIONS ARE MOST FAVORABLE
FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN THESE LEE AND
EAST SIDE AREAS. MOST GUIDANCE FOCUSES ACTIVITY THIS EVENING IN
THE WARNER MOUNTAINS OF LAKE COUNTY AND ANOTHER IN NORTHERN LAKE
COUNTY THIS EVENING. WHILE FIRE DANGER DID REACH HIGH IN PORTIONS
OF THE MODOC ON MONDAY, FORECAST FIRE DANGER FOR TODAY IS
MODERATE. ADDITIONALLY, DEPARTURE FROM AVERAGE GREENNESS IS SPOTTY
IN TERMS OF DEFICITS, SO SUSPECT THERE`S SOME GREEN-UP COMPONENT
TO THE LIVE FUELS NOW. MODELS INDICATE THAT ANY STORMS THAT DO GET
GOING WILL PRODUCE GUSTY OUTFLOW WINDS MAINLY IN THE 20 TO 30 MPH
RANGE, BUT ALSO SOME MEASURABLE RAINFALL. THUS, DESPITE UNUSUALLY
DRY CONDITIONS DUE TO THE ONGOING DROUGHT, WE HAVE DECIDED THAT
THIS EVENT DOES NOT WARRANT ANY WARNINGS. INSTEAD, A HEADS-UP TYPE
OF HEADLINE WILL BE MAINTAINED IN THE FORECAST. BTL/PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT THURSDAY FOR
PZZ350-356-370-376.
HAZARDOUS SEAS WARNING UNTIL 5 AM PDT THURSDAY FOR PZZ356-376.
GALE WARNING UNTIL 5 AM PDT THURSDAY FOR PZZ356-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT THURSDAY
FOR PZZ350-356-370-376.
$$
FJB/FJB/FJB
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
216 AM CDT WED APR 22 2015
.AVIATION...
EARLIER TAF CONTINUED TO LEAN TOWARDS STRATUS PROSPECTS LATER
TONIGHT WITH IMPROVED MOISTURE IN SOUTHERLY FLOW AND OLD OUTFLOW
IMPACTING KCDS...WHICH STILL LOOKS LIKE MOST IMMINENT CHANCE FOR
LOW CEILING NEAR DAYBREAK. WE WILL BE WATCHING APPROACHING STRATUS
FROM THE SOUTH AS WELL WHICH COULD IMPACT KLBB AND KPVW BRIEFLY
NEAR OR JUST AFTER DAYBREAK. OTHERWISE...BEST CHANCE FOR THUNDER
LATER TODAY WILL BE ALONG AND JUST NORTH OF A STATIONARY BOUNDARY
THAT WILL BE JUST SOUTH OF KCDS LATER TODAY THUS EARNING A PROB30
FOR THUNDER. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 633 PM CDT TUE APR 21 2015/
AVIATION...
ISOLATED SHOWERS NEAR THE NM STATE LINE WEST OF LUBBOCK EXPECTED
TO DISSIPATE BEFORE REACHING KLBB AND KPVW. ATTENTION THEN SHIFTS
TO POTENTIAL FOR LOW CLOUDS WEDNESDAY MORNING. BETTER CHANCES
APPEAR TO BE AT KCDS BEHIND A WEAK COLD FRONT OR OUTFLOW BOUNDARY
THAT WILL BE PUSHED SOUTH THROUGH THE PANHANDLE LATER TONIGHT.
LOW LEVEL MOISTURE ADVECTION BEHIND THE RETREATING DRYLINE COULD
LEAD TO SOME FOG AND/OR STRATUS AT BOTH KLBB AND KPVW TOWARD 12Z
BUT SIGNAL NOT QUITE AS STRONG. WILL KEEP THOSE TAFS AS INHERITED
AND REEVALUATE WITH THE 06Z ISSUANCE.
PREV DISCUSSION... /ISSUED 344 PM CDT TUE APR 21 2015/
SHORT TERM...
SURFACE DEWPOINTS HAVE BEEN FAIRLY STAGNANT ACROSS THE FORECAST AREA
TODAY AS MODEST ADVECTION BALANCES MIXING. AT 3 PM...SATELLITE
IMAGERY SHOWED A DEVELOPING CUMULUS FIELD IN EASTERN NEW MEXICO
WHERE THE DEWPOINTS ARE MOSTLY IN THE 30S. MORE EXTENSIVE
DEVELOPMENT WAS ONGOING ACROSS THE SACRAMENTOS AND SANGRES OF NM.
THE HRRR HAS BEEN FAIRLY CONSISTENT WITH BRINGING SOME OF THIS
ACTIVITY EASTWARD ACROSS THE WESTERN AND CENTRAL SOUTH PLAINS LATE
THIS AFTERNOON AND EVENING...ALTHOUGH IT IS ABOUT THE ONLY MODEL TO
DO SO. FCST SOUNDINGS IN THESE AREAS INDICATE ANY STORMS THAT DO
DEVELOP WILL BE HIGH-BASED HAVE LITTLE CAPE TO WORK WITH...SO THEY
WILL ONLY BE CAPABLE OF SPOTTY RAIN AND STRONG WIND GUSTS. IF ANY
STORMS CAN SURVIVE FARTHER TO THE EAST THIS EVENING AND ENCOUNTER
THE DEEPER MOISTURE...IT IS NOT OUT OF THE QUESTION THAT A HAIL
THREAT COULD DEVELOP...BUT THIS APPEARS UNLIKELY AT THIS TIME.
TONIGHT...THE LOW LEVEL JET WILL BRING RICHER MOISTURE NWWD INTO
WEST TEXAS...WITH THE SURFACE DRYLINE RETREATING THROUGH MOST IF NOT
ALL OF THE CWA...PERHAPS HOLDING BACK ACROSS THE FAR SW TX
PANHANDLE. NAM FCST SNDGS SHOW FOG POTENTIAL ACROSS THE SOUTHERN AND
CENTRAL SOUTH PLAINS BY EARLY WED MORNING SO WE HAVE ADDED A PATCHY
MENTION IN THE GRIDS....SOME AREAS OF LOW STRATUS ARE POSSIBLE AS
WELL. MEANWHILE TO OUR NORTH ACROSS THE PANHANDLES...THEY WILL
LIKELY SEE SOME OVERNIGHT TSTM ACTIVITY COINCIDING WITH A SWD-MOVING
COLD FRONT. IT IS UNCERTAIN WHAT IMPACT STORM COLD POOLS MAY HAVE ON
THE PROGRESS OF THE FRONT...WHICH TENDS TO LOWER OUR CONFIDENCE ON
HOW THE FRONT/OUTFLOW BOUNDARY WILL BEHAVE ON WEDNESDAY. IN
GENERAL...WE EXPECT THE BOUNDARY TO SINK SOUTH THROUGH THE FAR SRN
PANHANDLE AND POSSIBLY INTO THE NORTHERN ROLLING PLAINS. BACK TO THE
WEST...THE DRYLINE SHOULD FORM UP AND MOVE EAST AS A SURFACE TROUGH
DEVELOPS FROM EASTERN NM INTO THE ROLLING PLAINS. ALTHOUGH WE HAVE
TO STRESS A LARGE UNCERTAINTY IN THE PARTICULARS...A TRIPLE-POINT
MAY DEVELOP SOMEWHERE FROM OUR CENTRAL TO SOUTHEAST COUNTIES. BACKED
FLOW AND HIGH SURFACE MOISTURE WILL BE POSSIBLE ACROSS AT LEAST OUR
NE ZONES. WITH A MID-LVL SHORTWAVE PASSING ACROSS THE AREA DURING
THE DAY...STRONG INSTABILITY AND DEEP SHEAR IS LIKELY TO DEVELOP
ALONG AND TO THE NORTH AND EAST OF THE TRIPLE-POINT. GUIDANCE
GENERALLY SHOWS A STRONG CONVECTIVE SIGNAL IN THIS AREA BY LATE
AFTERNOON...ALTHOUGH WITH A LOT OF SPREAD RECORDING THE AREA
POTENTIALLY IMPACTED. WHERE STORMS OCCUR...SEVERE WEATHER WILL BE A
STRONG POSSIBILITY...INCLUDING THE POSSIBILITY OF TORNADOES
DEPENDING THE ORIENTATION/EVOLUTION ON THE BOUNDARY/S/. FARTHER
WEST...WE HAVE TRIMMED POPS DOWN OUR NEAR THE STATE LINE BUT LEFT A
SLIGHT CHANCE GOING ACROSS MUCH OF THE SOUTH PLAINS IN CASE THE
DRYLINE IS FARTHER WEST THAN ANTICIPATED.
LONG TERM...
THE PATTERN THEME THROUGH EARLY NEXT WEEK REMAINS THAT OF A
PROGRESSIVE ONE AS A SERIES OF SOUTHERN STREAM TROUGHS IMPACT THE
REGION. ONLY UNTIL THEREAFTER DOES THE PATTERN SHOW SIGNS OF
TRENDING MORE STAGNANT IN THE FORM OF MID-CONUS LONGWAVE RIDGING.
ALL DAYS CONSIDERED...WEDNESDAY EVENING LOOKS TO GRAB THE LIMELIGHT
FOR SENSIBLE WEATHER AS A SEVERE CONVECTIVE EPISODE SHOULD BE WELL
UNDERWAY. LOCATION OF THIS EVENT WILL BE HIGHLY DEPENDENT ON A
STATIONARY FRONT CURRENTLY PROGGED TO BISECT OUR CWA FROM NW-SE BY
LATE EVENING...THOUGH MODELS CONTINUE TO FAVOR OUR NERN COUNTIES.
BACKGROUND FORCING APPEARS RATHER SUBDUED AND LINKED MOSTLY TO A
SHORTWAVE TROUGH CRESTING SHALLOW RIDGING ALOFT AND A NORTHWARD PUSH
OF STRONGER SUBTROPICAL WINDS. THIS ALONG WITH FAVORABLE DEEP SHEAR
MAY SERVE TO KEEP CONVECTIVE MODES RESTRICTED TO ISOLATED OR
SCATTERED SUPERCELLS. FEEL 40-50 PERCENT POPS WED EVENING ARE
REPRESENTATIVE OF THIS SCENARIO FOR NOW BEFORE PRECIP EVENTUALLY
MOVES DOWNSTREAM LATE WED NIGHT.
BEYOND WEDNESDAY NIGHT...THE WAVERING FRONTAL BOUNDARY SHOULD LIFT
NORTH AS A WARM FRONT IN ADVANCE OF A MORE ROBUST TROUGH LIFTING OUT
OF THE DESERT SOUTHWEST. THIS WAVE WILL PROJECT EVEN STRONGER WINDS
ATOP THE REGION PERHAPS ACCOMPANIED BY OCCASIONAL IMPULSES AND
SLIGHT CHANCE POPS...ESPECIALLY OFF THE CAPROCK WHERE LL MOISTURE
WILL HAVE A GREATER RESIDENCE TIME. MODEL CONSENSUS IS FOR DRY
SLOTTING TO SURGE ATOP THE CAPROCK COUNTIES BY EARLY FRIDAY AND
QUICKLY SWEEP EAST AS THE BASE OF THE TROUGH LIFTS TO OUR NORTH.
THE TIMING AND PATH OF THIS TROUGH SUGGEST A WINDY DAY IS IN STORE
YET WE REMAIN A BIT RELUCTANT TO BITE ON THE STRONG WINDS AS
PROGGED BY THE GFS AT TIMES. TIME-HEIGHT X-SECTIONS SHOW NEXT TO
NIL CIRRUS...SO WE MAY NEED TO RATCHET UP OUR 20-30 MPH WINDS
EVEN FURTHER IN LATER FORECASTS IF THIS THEME PERSISTS.
BY SATURDAY...QUIETER WEATHER UNDER TRANSIENT RIDGING WILL BE
REPLACED BY ONE FINAL TROUGH AT SOME POINT ON SUNDAY AHEAD OF
MODIFIED CANADIAN AIR WHICH LOOKS TO DIVE INTO THE GULF COME
MONDAY. PRECIP MERIT FROM SUN-SUN NIGHT DOESN/T SHOW MUCH
SUBSTANCE AMONG THE LATEST GLOBAL MODELS...SO POPS WERE SCALED
BACK IN COVERAGE TO BETTER MATCH THE DRIER SUPERBLEND AND
CONSENSUS ROUTES.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 80 48 79 50 / 20 10 0 10
TULIA 79 51 78 53 / 30 20 10 10
PLAINVIEW 81 52 78 54 / 20 20 10 10
LEVELLAND 83 51 80 55 / 10 10 0 10
LUBBOCK 83 52 80 56 / 20 10 10 10
DENVER CITY 83 53 80 54 / 10 0 0 10
BROWNFIELD 83 53 81 57 / 10 10 0 10
CHILDRESS 78 56 77 60 / 50 40 20 20
SPUR 82 59 81 61 / 20 20 20 20
ASPERMONT 84 61 82 63 / 20 20 20 30
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
216 AM EDT WED APR 22 2015
.SYNOPSIS...
HIGH PRESSURE WILL STAY SOUTH OF US TONIGHT WHILE A FRONT MOVES IN
FROM THE NORTHWEST. THIS FRONT WILL CROSS THE REGION WEDNESDAY AND
SHIFT OFFSHORE BY THURSDAY MORNING RESULTING IN BREEZY CONDITIONS
WEDNESDAY INTO THURSDAY AHEAD AND BEHIND THE FRONT. BY
FRIDAY...HIGH PRESSURE WILL BE SITUATED FROM THE WESTERN GREAT
LAKES...SOUTH INTO THE SOUTHERN APPALACHIANS.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 200 AM EDT WEDNESDAY...
SOME TEMPERATURE ADJUSTMENTS WERE NEEDED AS INCREASING CLOUD COVER
ACROSS THE WESTERN MOUNTAINS RESULTING IN TEMPS HOLDING CLOSE TO
50...WHILE PIEDMONT AREAS WELL DOWN INTO THE 40S. CLOUDS WILL BE
INCREASING FROM THE WEST...BUT REMAIN MOSTLY CLEAR EAST OF THE
BLUE RIDGE THROUGH DAYBREAK. HAVE ADJUSTED WESTERN AREAS UP IN
TEMPERATURE...BUT KEPT EASTERN AREAS NEAR OR EVEN A DEGREE OR TWO
BELOW EARLIER ADVERTISED MIN TEMPS. MIN TEMPS COULD WELL BE
REALIZED BY 10Z IN WESTERN AREAS...THEN INCREASING WITH WEST
WINDS AND CLOUD COVER. OTHER FORECAST ELEMENTS APPEAR TO BE ON
TRACK.
AS OF 912 PM EDT TUESDAY...
EVENING SOUNDINGS AND SURFACE OBS SHOW VERY DRY AIR LINGERING OVER
THE REGION THIS EVENING AHEAD OF A WEAK TROUGH JUST WEST OF THE
MOUNTAINS AND THE NEXT COLD FRONT IN THE UPPER MIDWEST. INITIAL
BAND OF BROKEN CLOUDS NOW CROSSING THE OHIO RIVER MAY BRING A FEW
SPRINKLES TO THE WESTERN SLOPES BEFORE FADING AFTER MIDNIGHT GIVEN
DEEP WESTERLY FLOW AND A LINGERING WELL MIXED DRY LAYER JUST OFF
THE SURFACE. APPEARS NEXT ROUND OF POTENTIAL SHOWERS WONT ARRIVE
UNTIL WED MORNING AHEAD OF THE FRONT SO TRIMMING BACK WESTERN POPS
A BIT MORE OVERNIGHT SIMILAR TO THE LATEST HRRR TRENDS. OTRW
MOSTLY CLEAR TO INIT THEN BECOMING PARTLY TO MOSTLY CLOUDY AT
TIMES FAR WEST AND PC ELSW LATE. TEMPS TO ZOOM DOWN IN THE WESTERN
VALLEYS EARLY ON AS WINDS FADE WITH SOME SPOTS FALLING INTO THE
30S BEFORE BUMPING UP WITH CLOUDS LATER ON. LATEST LAV MOS SLOW TO
DROP VALUES BUT LIKELY TOO WARM EXCEPT ON THE RIDGES GIVEN SUCH
LOW DEWPOINTS THIS EVENING SO ONLY MAKING SLIGHT TWEAKS IN SPOTS.
PREVIOUS DISCUSSION AS OF 300 PM EDT TUESDAY...
VERY DRY AT THE MOMENT WITH FEW TO SCATTERED CU. UPSTREAM...SFC FRONT
WORKING INTO THE MIDWEST WILL BE OUR NEXT WEATHER MAKER...AND WIND
WILL BE THE MAIN CULPRIT.
THIS EVENING INTO THE OVERNIGHT THE SKIES WILL BE STAY CLEAR TO
PARTLY CLOUDY THEN SHOULD SEE MORE CLOUDS ARRIVE AFTER MIDNIGHT INTO
THE MTNS. SLOWED DOWN ONSET OF POPS GIVEN DRY LOW LVLS...THOUGH WILL
SEE A FEW SHOWERS MAKE IT TO GREENBRIER TO THE MTN EMPIRE AROUND
DAWN.
TEMPS WILL BE DROPPING QUICKER THIS EVENING ONCE THE WINDS SETTLE
DOWN SOME. ALOFT HOWEVER...WINDS SHOULD STAY UP KEEPING HIGHER
TERRAIN MIXED. KEEPING THE WRN SLOPES IN THE 40S FOR LOWS...WHILE
VALLEYS IN THE MTNS AND FOOTHILLS FALL INTO THE UPPER 30S. NOT
EXPECTING ANY FROST/FREEZE CONCERNS.
FOR WEDNESDAY....THE LOW LEVEL JET SETS UP FROM KENTUCKY TO MARYLAND
DURING THE MORNING/EARLY AFTERNOON. SFC FRONT WILL MAKE IT INTO THE
WV MTNS BY MIDDAY THEN SLOWLY DROP SE INTO THE PIEDMONT BY EVENING.
STABILITY SEEMS MARGINAL BUT WIND ENERGY WITH SHOWERS ARE A CONCERN
FOR GUSTY SHOWERS AND POSSIBLE THUNDERSTORMS. SPC HAS MARGINAL RISK
EAST OF ROANOKE TOWARD LYH/RIC...FOR DAMAGING WINDS. ATTM...WILL
HAVE GUSTY WIND WORDING IN THE THUNDERSTORMS FOR WED AFTERNOON.
THE WAA PATTERN AND WINDS ALOFT FAVOR SOME OF THE HIGHER RIDGES FROM
HSP TO BOONE TO GET CLOSE TO ADVISORY LEVELS OF 46 MPH FOR GUSTS.
OVERALL..THE WINDS WILL STAY BELOW THIS AS WE USUALLY NEED A 50-55
KT 8H JET AND THE MODELS KEEP THE BEST WINDS SITUATED NORTH OF US.
WEDNESDAY WILL NOT BE WASHOUT AND WSW FLOW AT TIMES SHOULD LIMIT
STORM/SHOWER DEVELOPMENT EAST OF THE MTNS...BUT ENOUGH BACKING
SHOULD ALLOW FOR OVERALL LOW LVL CONVERGENCE NOT TO KEEP IT
COMPLETELY DRY.
GOING TOWARD DUSK...THE SHOWERS WILL FADE IN COVERAGE. WEDNESDAY
WILL BE MILD/SEASONAL WITH HIGHS FROM THE UPPER 50S SE WV TO LOWER
TO MID 70 SOUTHEAST.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
AS OF 230 PM EDT TUESDAY...
A WEAK COLD FRONT WILL SLIDE EAST OF THE AREA WEDNESDAY EVENING. ANY
LINGERING SHOWERS WILL DISSIPATE BY 10P WITH LOSE OF HEATING AND
INCREASE DRIER AIR ADVECTION. THE 12Z GFS IS IN AGREEMENT WITH THIS
SCENARIO...SO THE FORECAST IS MORE HEAVILY WEIGHTED TO THAT
SOLUTION. HIGH PRESSURE CONTINUES TO BUILD EAST INTO THE AREA
THURSDAY...HOWEVER A MODEST PRESSURE GRADIENT WILL KEEP BREEZY AND
GUSTY NORTHWEST WINDS OVER THE AREA THROUGH THE DAY. THE CENTER OF
THE HIGH DRIFTS OVER THE AREA THURSDAY NIGHT WITH CALMING WINDS AND
COOLER THAN NORMAL TEMPERATURES INTO THE DAY FRIDAY. TEMPERATURES
THURSDAY AND FRIDAY WILL RANGE FROM THE UPPER 50S TO LOWER 60S
ACROSS THE MOUNTAINS TO MID TO UPPER 60S EAST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 240 PM EDT TUESDAY...
A WARM FRONT WILL ENTER THE REGION FROM THE SOUTHWEST FRIDAY NIGHT
BRINGING AN INCREASE IN CLOUDS AND THE CHANCE FOR RAIN SATURDAY
MORNING. RAIN CHANCES INCREASE DURING SATURDAY AFTERNOON AS
ISENTROPIC LIFT INCREASES WITH WARM MOIST AIR OVERRUNNING COOLER
SURFACE AIR. A SURFACE WAVE IS EXPECTED TO TRACK OVER THE TENNESSEE
VALLEY SATURDAY...THEN ACROSS THE CAROLINAS SUNDAY. THIS WAVE WILL
CONTINUE THE CHANCE FOR RAIN IN THE AREA THROUGH SUNDAY
MORNING...THEN A BACK DOOR COLD FRONT BRINGS COOLER DRIER AIR INTO
THE REGION FOR SUNDAY AFTERNOON INTO MONDAY. A STRONGER SURFACE WAVE
TRACKS ACROSS THE TENNESSEE VALLEY TO THE CAROLINA MONDAY NIGHT INTO
TUESDAY. THIS WAVE WILL HAVE MORE MOISTURE AND DYNAMICS TO BRING
SOME HEAVY RAIN AND STRONG STORMS TO THE REGION. TEMPERATURES
THROUGH THE PERIOD WILL REMAIN COOLER THAN NORMAL WITH UPPER 50S TO
LOWER 60S ACROSS THE MOUNTAINS TO MID TO UPPER 60S EAST.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 200 AM EDT WEDNESDAY...
BROAD UPPER TROUGH CENTERED OVER THE GREAT LAKES WILL CONTINUE TO
DOMINATE THE WEATHER ACROSS THE EASTERN U.S. THROUGH THE PERIOD.
MAIN FOCUS TODAY WILL BE ON A STRONG SHORT WAVE PROGGED TO TRACK
THROUGH THE BASE OF THE TROUGH ACROSS OUR REGION DURING THE
AFTERNOON. ALTHOUGH THE SFC AIR MASS IS VERY DRY IN THE WAKE OF
THE SUN-MON SYSTEM...STRONG DYNAMICS ASSOCIATED WITH THIS SHORT
WAVE WILL OVERCOME THE SFC DRYNESS AND RESULT IN ELEVATED
CONVECTION FROM MID-MORNING INTO THE AFTERNOON. WITH A 50-60KT
WESTERLY LLJ ASSOCIATED WITH THE SHORT WAVE...ANY CONVECTION COULD
BRING THESE STRONG WINDS DOWN TO THE SFC. WINDS WILL BE AN ISSUE
EVEN OUTSIDE CONVECTION...WITH A STRONG GRADIENT DEVELOPING
QUICKLY THIS MORNING. MANY LOCATIONS WILL SEE SW-W WINDS 15-20KTS
WITH GUSTS 25-35KTS IN THE 15Z-23Z TIME FRAME...VEERING MORE TO
THE WNW BY 00Z BEHIND THE SHORT WAVE AND DECREASING INTO THE
10-15KTS WITH GUSTS 20-25KTS. CIGS SHOULD BOTTOM OUT MOSTLY IN THE
040-050 RANGE...EXCEPT IN UPSLOPE AREAS BLF-LWB WHERE CIGS MAY
DROP INTO THE 030-035 RANGE DURING THE AFTERNOON IN ASSOCIATION
WITH SHRA ACTIVITY. VSBYS COULD BRIEFLY BECOME MVFR IN HEAVIER
SHOWERS MAINLY WESTERN MOUNTAINS. SPC HAS THE ENTIRE AREA EAST OF
THE ALLEGHANY FRONT OUTLOOKED FOR MARGINAL SEVERE TODAY...WITH THE
MAIN CONCERNS STRONG WINDS GUSTS GIVEN THE VERY STRONG WINDS ALOFT
AND PENNY TO QUARTER- SIZED HAIL GIVEN THE VERY COLD TEMPERATURES
ALOFT. FOR NOW...HAVE ONLY INTRODUCED TSRA FOR LYH...BUT
CONDITIONS MAY WARRANT ADDING THIS FOR BCB/ROA/DAN WITH LATER TAF
ISSUANCES.
MEDIUM TO HIGH CONFIDENCE IN CIGS AND VSBYS THROUGH THE TAF VALID
PERIOD.
MEDIUM TO HIGH CONFIDENCE IN WIND SPD/DIR THROUGH THE TAF VALID
PERIOD.
MEDIUM CONFIDENCE IN THUNDER POTENTIAL LATE MORNING THROUGH
AFTERNOON.
EXTENDED AVIATION DISCUSSION...
FRONT WILL EXIT BY WEDNESDAY NIGHT WITH HIGH PRESSURE BUILDING INTO
THE REGION FROM THE WEST THU-FRI. SOME GRADIENT REMAINS BETWEEN
DEPARTING FRONT AND HIGH TO THE WEST THURSDAY AND POSSIBLY
FRIDAY...SO GUSTY WINDS WILL REMAIN MAINLY DURING THE DAYTIME.
OVERRUNNING CLOUDS WORK INTO THE AREA FRIDAY AHEAD OF A WARM
FRONT. BY SATURDAY...ENOUGH MOISTURE TO ALLOW FOR SHOWERS AND MVFR
WITH BEST FORCING ACROSS THE CAROLINAS. THIS WILL BE POSSIBLE
INTO SUNDAY MORNING BEFORE THE SYSTEM EXITS AND SOME IMPROVEMENT
IN CIGS STARTS TO OCCUR LATER SUNDAY.
&&
.FIRE WEATHER...
AS OF 330 PM EDT TUESDAY...
WET FUELS WILL DRY OUT AS WE HEAD INTO WEDNESDAY. A FRONT WILL
APPROACH WEDNESDAY WITH GOOD MIXING OUT AHEAD OF IT. GUSTY WINDS
IN THE 25 TO 35 MPH RANGE WILL OCCUR AT TIMES OVER THE PIEDMONT
WHERE MIN RH SINKS TO 30 PERCENT DURING THE AFTERNOON. AT THIS
TIME A FEW SHOWERS AND STORMS COULD BE OCCURRING SO FIRE DANGER
FOR NOW IS LOW TO MODERATE AS 1 AND 10 HOUR FUELS HAVE EITHER
GREENED UP OR ARE GREENING UP. ISSUES WOULD BE WITH ANY LOOSE LEAF
LITTER THAT CAN DRY OUT ENOUGH...THOUGH SOILS THEMSELVES STAY
MOIST.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...JH/RAB/WP
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...RAB
FIRE WEATHER...WP
AREA FORECAST DISCUSSION
NWS PORTLAND
304 AM PDT WED APR 22 2015
.SYNOPSIS...ISOLATED POST-FRONTAL SHOWERS THIS MORNING SHOULD END
THIS AFTERNOON. A COUPLE OF WEAK FRONTS WILL BRING PERIODS OF LIGHT
RAIN THURSDAY AND FRIDAY. FEW SHOWERS WILL LINGER SATURDAY. A WARM
FRONT WILL BRUSH ACROSS THE AREA SUNDAY...BUT AN UPPER RIDGE WILL
HELP WHISK THIS SYSTEM QUICKLY NORTHWARD....AND LIMIT PRECIPITATION
FOR NORTHWEST OREGON MONDAY AND TUESDAY.
&&
.SHORT TERM...TODAY THROUGH SATURDAY...SATELLITE IMAGERY SHOWS
WIDESPREAD OPEN-CELLED CUMULUS OVER THE NE PACIFIC EARLY THIS MORNING
IN THE WAKE OF A WEAK COLD FRONT...THAT IS CURRENTLY MOVING OVER THE
CASCADES. THE FRONT IS ON THE DRY SIDE AND HAVE NOT OBSERVED MUCH IF
ANY PRECIPITATION FROM IT. ONSHORE WINDS WILL BRING THE SHOWERS FROM
THE PACIFIC TO THE NORTH COAST AND NORTH COAST RANGE THIS
MORNING...BUT THE REST OF THE AREA SHOULD REMAIN MOSTLY DRY. MID AND
HIGH CLOUDS OVER THE CASCADES AND CASCADE FOOTHILLS ASSOCIATED WITH
THE DECAYING FRONT SHOULD DEPART THE AREA THIS AFTERNOON. A COLDER
AIRMASS OVER THE REGION WILL MAINTAIN NEAR OR SLIGHTLY BELOW NORMAL
MAXIMUM TEMPERATURES TODAY...DESPITE ANY SUN BREAKS.
MODELS HAVE SLOWED THE TIMING OF THE NEXT APPROACHING FRONT...AND DO
NOT EXPECT PRECIPITATION TO RETURN TO THE COAST UNTIL EARLY THURSDAY
MORNING...AND INLAND AREAS THURSDAY AFTERNOON. SOME CLEARING TONIGHT
WILL RESULT IN COLD OVERNIGHT TEMPERATURES AND EXPECT SOME INLAND
AREAS TO DIP INTO THE 30S. THE FRONT ON THURSDAY HAS A BIT MORE
MOISTURE THAN THE CURRENT FRONT...AND MORE AREAS SHOULD SEE SOME
MEASURABLE PRECIPITATION THURSDAY AFTERNOON AND EVENING...BUT TOTALS
WILL STILL BE LIGHT...LESS THAN 0.25 INCH. THE FRONT WILL MOVE EAST
OF THE AREA LATE THURSDAY NIGHT.
AN UPPER LOW WILL MAINTAIN COOL AND SHOWERY WEATHER FRIDAY AND
SATURDAY WITH SNOW LEVELS REMAINING NEAR OR JUST BELOW THE CASCADE
PASSES. QPF WILL REMAIN LOW...AN DOD NOT EXPECT MUCH IF ANY SNOW
ACCUMULATION WITH THE SHOWERS. TJ
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...MODELS HAVE BEEN
STRUGGLING WITH THE LONG TERM FORECAST...BUT ARE BEGINNING TO SHOW
SOME AGREEMENT THAT A WARM FRONT WILL PRODUCE LIGHT RAIN ACROSS THE
REGION SUNDAY BEFORE AN UPPER RIDGE BUILDS OVER THE AREA. THE UPPER
RIDGE MAY SEND APPROACHING FRONTS NORTH OF THE PORTLAND FORECAST AREA
AND HAVE TRENDED TOWARDS A DRIER AND WARMER FORECAST FOR MUCH OF THE
LONG TERM. THE MODELS HAVE BEEN VERY INCONSISTENT RUN TO RUN...AND SO
DID NOT COMPLETELY REMOVE THE CHANCE FOR PRECIPITATION. TJ
&&
.AVIATION...CIGS ARE STARTING TO RISE AND BREAK UP BEHIND THE
FRONT THIS EVENING. MODELS HAVE BACKED OFF MVFR CIGS RETURNING
OVERNIGHT AND IN THE EARLY WEDNESDAY MORNING HOURS...EXCEPT A FEW
HOURS ALONG THE COAST WITH CIGS POSSIBLY JUST BELOW 3000 FT. WINDS
ARE ALREADY STARTING TO DECREASE AND WILL CONTINUE TO DO SO
OVERNIGHT...BUT NW WINDS MAY REMAIN GUSTY TO AROUND 20 KT ALONG
THE COAST. EXPECT VFR CONDITIONS INLAND THROUGHOUT THE DAY
WEDNESDAY AND BACK TO VFR BY LATE WED MORNING ALONG THE COAST.
KPDX AND APPROACHES...CIGS RISING THIS EVENING AND WILL BREAK UP
OVERNIGHT. COULD SEE A CIG REDEVELOP AROUND 4000 TO 5000 FT WED
MORNING BUT CONDITIONS ARE EXPECTED TO REMAIN VFR THROUGH THE
FORECAST PERIOD. WINDS WILL CONTINUE TO DECREASE THROUGH THE
OVERNIGHT HOURS.
&&
.MARINE...MINOR TWEAKING OF WINDS AND SEAS OVER NEXT 24 HOURS
WITH THE EVENING UPDATE. MODELS ARE IN AGREEMENT WITH TRENDING
WINDS DOWN MORE QUICKLY WEDNESDAY BUT WILL WAIT FOR FURTHER
CONFIRMATION BEFORE SHORTENING THE SMALL CRAFT ADVISORY. BOWEN
PREVIOUS DISCUSSION...AFTER QUITE SOME TIME...BUOY 50 APPEARS TO
HAVE RETURNED THIS AFTERNOON! NWLY SMALL CRAFT ADVISORY WINDS WITH
GUSTS 25-30 KTS WILL CONTINUE ACROSS THE COASTAL WATERS THROUGH
LATE TONIGHT/ EARLY WEDNESDAY MORNING. SEAS SLOWLY RISING THIS
AFTERNOON AS WELL...WITH A NWLY SWELL AROUND 10 FT EXPECTED TO
ARRIVE BY THIS EVENING AND PEAKING AROUND 11-12 FT TONIGHT. SEAS
GRADUALLY SUBSIDE BELOW 10 FT MIDDAY WEDNESDAY. A MUCH STRONGER
FRONT LOOKS TO MOVE ACROSS THE WATERS OVER THE WEEKEND AND WILL
LIKELY BRING GUSTY SOUTHERLY WINDS AND ANOTHER ROUND OF BUILDING
SEAS.
EXPECT ROUGH COLUMBIA RIVER BAR CONDITIONS DURING THE NEXT FEW
EBBS. WILL HAVE TO WATCH THE TONIGHT PERIOD AND IF SEAS RISE A
LITTLE HIGHER THAN ANTICIPATED ROUGH COLUMBIA RIVER BAR CONDITIONS
MAY OCCUR DURING NON EBB TIME. /27
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL NOON PDT WEDNESDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM PDT
WEDNESDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE
OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 PM
PDT THIS EVENING.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 5 AM TO
10 AM PDT WEDNESDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
[top]
Area Forecast Discussion
National Weather Service Spokane WA
238 AM PDT WED APR 22 2015
.SYNOPSIS...
A cold front will move through the area and bring cooler weather
and breezy conditions today. More seasonal temperatures and off
and on showery conditions will linger through the remainder of the
work week. A slightly stronger weather disturbance will result in
scattered, mainly mountains rain and snow showers Thursday night
into the weekend. High pressure with warm temperatures and dry
conditions will return for the beginning of next week.
&&
.DISCUSSION...
Today through Thursday...The upper trough and associated cold
front will slide through the region today bringing a chance of
showers to the Inland Northwest. The front itself is moisture
starved but there is a band of moisture moving up from the south
ahead of the front. This may be enough to conjure up isolated to
scattered showers across the southeast zones and into the Idaho
panhandle mountains but a few hundredths of an inch of
precipitation is likely all we will see from passing showers. The
cooler more dense marine air is accelerating down the Cascade gap
valleys and into the basin and Palouse with gusts generally in the
25 to 35 mph range with some of the windier ridgetop locations
occasionally gusting to 45 mph. Expect breezy to windy conditions
to continue through late this evening then winds will start to
diminish after midnight.
The presence of the upper trough and more cloud cover will keep
daytime temperatures about 12 to 15 degrees cooler that yesterday.
Tonight a flat ridge will briefly move over the region and if we
get a decent period of clearing along with light winds, the
northern valleys could get quite chilly overnight. Some mid to
high clouds will spread across the region in advance of the next
Pacific trough and this may keep overnight temperatures from
falling too much below the freezing mark. For Thursday, expect a
mostly dry day between systems before the next chance of showers
pushes into the Cascades late in the day. Temperatures will be
close to seasonal normals. /Kelch
Thursday night through Tuesday...The models appear to be
converging on a similar solution with the upper level low
Thursday night through Saturday evening. That closed low is
expected to drop through the Gulf of Alaska then take a drunken
and wobbly course south and east through southern B.C. and
northern Washington, before opening into a wave and exiting to the
east on Sunday. This is quite a bit different then what we were
looking at 24 hours ago, and will result in a much drier forecast
for the weekend. Sunday through Tuesday guidance begins to show
some differences as high pressure builds back into the Pac NW
ahead of another incoming Pacific wave.
Thursday night through Sunday moisture and small embedded short
waves will wrap around the upper level low. There is some weak
surface based instability each afternoon. This all adds up to a
chance for showers at times through the period. While just about
anywhere could see showers, the focus, as is typical, will be for
the mountains surrounding the Basin and Palouse. Showers will be
spotty and inconsistent, but should be more prominent with
afternoon heating. Snow levels will result in some light snow
accumulations mainly above 4000 feet. Temperatures will be cool
compared to the past several days with temps in the 50s and lower
60s which is just on the cool side of normal. Expect mainly
southwest winds around 10 mph, but winds are expected to become
breezy on Sunday as the upper low moves out and high pressure
begins to build off the coast.
Sunday through Tuesday...All of the model guidance is showing the
ridge building in from the west Sunday afternoon then
strengthening Monday and Tuesday. The differences show up on just
how strong the ridge becomes and the location of the ridge axis.
Southwest flow will tap into deeper moisture, but it now looks
like the strong atmospheric river is much less potent. In addition
the ridge should push any moisture north of the Inland Northwest.
With that in mind we kept some low end pops for Sunday, but then
dried out the forecast through Tuesday. Some light rain will be
possible along the Cascade crest, but any precipitation amounts
would tend to be light. South to southwest flow will result in
warming temperatures with afternoon temperatures jumping back up
into the mid 60s to mid 70s Monday and Tuesday. Winds will be out
of the south- southwest and remain 5-15 mph. Tobin
&&
.AVIATION...
06Z TAFS: A cold front will sweep across the region tonight. Showers
are expected to develop from around the KLWS/KPUW area and extend
up toward KCOE after 12Z. There is a slight possibility for MVFR
conditions with these showers, but is not expected due to the
amount of dry air that exists at low levels. Winds will be breezy
across much of the region through Wednesday afternoon with gusts
up to between 20-30 mph possible. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 59 36 60 39 57 37 / 10 0 0 20 10 10
Coeur d`Alene 58 34 61 37 57 35 / 20 10 0 20 20 10
Pullman 56 33 59 38 55 35 / 30 0 10 20 10 10
Lewiston 63 37 66 43 62 40 / 30 0 0 20 20 10
Colville 62 34 63 37 60 36 / 20 10 0 30 20 20
Sandpoint 57 32 60 35 56 33 / 30 10 10 30 20 20
Kellogg 54 34 60 36 54 34 / 30 10 0 30 30 10
Moses Lake 65 37 65 39 63 38 / 0 0 0 10 10 10
Wenatchee 64 42 64 43 62 41 / 0 0 0 10 20 20
Omak 64 34 64 37 62 35 / 10 10 10 20 30 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
238 AM PDT WED APR 22 2015
.SYNOPSIS...
A cold front will move through the area and bring cooler weather
and breezy conditions today. More seasonal temperatures and off
and on showery conditions will linger through the remainder of the
work week. A slightly stronger weather disturbance will result in
scattered, mainly mountains rain and snow showers Thursday night
into the weekend. High pressure with warm temperatures and dry
conditions will return for the beginning of next week.
&&
.DISCUSSION...
Today through Thursday...The upper trough and associated cold
front will slide through the region today bringing a chance of
showers to the Inland Northwest. The front itself is moisture
starved but there is a band of moisture moving up from the south
ahead of the front. This may be enough to conjure up isolated to
scattered showers across the southeast zones and into the Idaho
panhandle mountains but a few hundredths of an inch of
precipitation is likely all we will see from passing showers. The
cooler more dense marine air is accelerating down the Cascade gap
valleys and into the basin and Palouse with gusts generally in the
25 to 35 mph range with some of the windier ridgetop locations
occasionally gusting to 45 mph. Expect breezy to windy conditions
to continue through late this evening then winds will start to
diminish after midnight.
The presence of the upper trough and more cloud cover will keep
daytime temperatures about 12 to 15 degrees cooler that yesterday.
Tonight a flat ridge will briefly move over the region and if we
get a decent period of clearing along with light winds, the
northern valleys could get quite chilly overnight. Some mid to
high clouds will spread across the region in advance of the next
Pacific trough and this may keep overnight temperatures from
falling too much below the freezing mark. For Thursday, expect a
mostly dry day between systems before the next chance of showers
pushes into the Cascades late in the day. Temperatures will be
close to seasonal normals. /Kelch
Thursday night through Tuesday...The models appear to be
converging on a similar solution with the upper level low
Thursday night through Saturday evening. That closed low is
expected to drop through the Gulf of Alaska then take a drunken
and wobbly course south and east through southern B.C. and
northern Washington, before opening into a wave and exiting to the
east on Sunday. This is quite a bit different then what we were
looking at 24 hours ago, and will result in a much drier forecast
for the weekend. Sunday through Tuesday guidance begins to show
some differences as high pressure builds back into the Pac NW
ahead of another incoming Pacific wave.
Thursday night through Sunday moisture and small embedded short
waves will wrap around the upper level low. There is some weak
surface based instability each afternoon. This all adds up to a
chance for showers at times through the period. While just about
anywhere could see showers, the focus, as is typical, will be for
the mountains surrounding the Basin and Palouse. Showers will be
spotty and inconsistent, but should be more prominent with
afternoon heating. Snow levels will result in some light snow
accumulations mainly above 4000 feet. Temperatures will be cool
compared to the past several days with temps in the 50s and lower
60s which is just on the cool side of normal. Expect mainly
southwest winds around 10 mph, but winds are expected to become
breezy on Sunday as the upper low moves out and high pressure
begins to build off the coast.
Sunday through Tuesday...All of the model guidance is showing the
ridge building in from the west Sunday afternoon then
strengthening Monday and Tuesday. The differences show up on just
how strong the ridge becomes and the location of the ridge axis.
Southwest flow will tap into deeper moisture, but it now looks
like the strong atmospheric river is much less potent. In addition
the ridge should push any moisture north of the Inland Northwest.
With that in mind we kept some low end pops for Sunday, but then
dried out the forecast through Tuesday. Some light rain will be
possible along the Cascade crest, but any precipitation amounts
would tend to be light. South to southwest flow will result in
warming temperatures with afternoon temperatures jumping back up
into the mid 60s to mid 70s Monday and Tuesday. Winds will be out
of the south- southwest and remain 5-15 mph. Tobin
&&
.AVIATION...
06Z TAFS: A cold front will sweep across the region tonight. Showers
are expected to develop from around the KLWS/KPUW area and extend
up toward KCOE after 12Z. There is a slight possibility for MVFR
conditions with these showers, but is not expected due to the
amount of dry air that exists at low levels. Winds will be breezy
across much of the region through Wednesday afternoon with gusts
up to between 20-30 mph possible. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 59 36 60 39 57 37 / 10 0 0 20 10 10
Coeur d`Alene 58 34 61 37 57 35 / 20 10 0 20 20 10
Pullman 56 33 59 38 55 35 / 30 0 10 20 10 10
Lewiston 63 37 66 43 62 40 / 30 0 0 20 20 10
Colville 62 34 63 37 60 36 / 20 10 0 30 20 20
Sandpoint 57 32 60 35 56 33 / 30 10 10 30 20 20
Kellogg 54 34 60 36 54 34 / 30 10 0 30 30 10
Moses Lake 65 37 65 39 63 38 / 0 0 0 10 10 10
Wenatchee 64 42 64 43 62 41 / 0 0 0 10 20 20
Omak 64 34 64 37 62 35 / 10 10 10 20 30 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
238 AM PDT WED APR 22 2015
.SYNOPSIS...
A cold front will move through the area and bring cooler weather
and breezy conditions today. More seasonal temperatures and off
and on showery conditions will linger through the remainder of the
work week. A slightly stronger weather disturbance will result in
scattered, mainly mountains rain and snow showers Thursday night
into the weekend. High pressure with warm temperatures and dry
conditions will return for the beginning of next week.
&&
.DISCUSSION...
Today through Thursday...The upper trough and associated cold
front will slide through the region today bringing a chance of
showers to the Inland Northwest. The front itself is moisture
starved but there is a band of moisture moving up from the south
ahead of the front. This may be enough to conjure up isolated to
scattered showers across the southeast zones and into the Idaho
panhandle mountains but a few hundredths of an inch of
precipitation is likely all we will see from passing showers. The
cooler more dense marine air is accelerating down the Cascade gap
valleys and into the basin and Palouse with gusts generally in the
25 to 35 mph range with some of the windier ridgetop locations
occasionally gusting to 45 mph. Expect breezy to windy conditions
to continue through late this evening then winds will start to
diminish after midnight.
The presence of the upper trough and more cloud cover will keep
daytime temperatures about 12 to 15 degrees cooler that yesterday.
Tonight a flat ridge will briefly move over the region and if we
get a decent period of clearing along with light winds, the
northern valleys could get quite chilly overnight. Some mid to
high clouds will spread across the region in advance of the next
Pacific trough and this may keep overnight temperatures from
falling too much below the freezing mark. For Thursday, expect a
mostly dry day between systems before the next chance of showers
pushes into the Cascades late in the day. Temperatures will be
close to seasonal normals. /Kelch
Thursday night through Tuesday...The models appear to be
converging on a similar solution with the upper level low
Thursday night through Saturday evening. That closed low is
expected to drop through the Gulf of Alaska then take a drunken
and wobbly course south and east through southern B.C. and
northern Washington, before opening into a wave and exiting to the
east on Sunday. This is quite a bit different then what we were
looking at 24 hours ago, and will result in a much drier forecast
for the weekend. Sunday through Tuesday guidance begins to show
some differences as high pressure builds back into the Pac NW
ahead of another incoming Pacific wave.
Thursday night through Sunday moisture and small embedded short
waves will wrap around the upper level low. There is some weak
surface based instability each afternoon. This all adds up to a
chance for showers at times through the period. While just about
anywhere could see showers, the focus, as is typical, will be for
the mountains surrounding the Basin and Palouse. Showers will be
spotty and inconsistent, but should be more prominent with
afternoon heating. Snow levels will result in some light snow
accumulations mainly above 4000 feet. Temperatures will be cool
compared to the past several days with temps in the 50s and lower
60s which is just on the cool side of normal. Expect mainly
southwest winds around 10 mph, but winds are expected to become
breezy on Sunday as the upper low moves out and high pressure
begins to build off the coast.
Sunday through Tuesday...All of the model guidance is showing the
ridge building in from the west Sunday afternoon then
strengthening Monday and Tuesday. The differences show up on just
how strong the ridge becomes and the location of the ridge axis.
Southwest flow will tap into deeper moisture, but it now looks
like the strong atmospheric river is much less potent. In addition
the ridge should push any moisture north of the Inland Northwest.
With that in mind we kept some low end pops for Sunday, but then
dried out the forecast through Tuesday. Some light rain will be
possible along the Cascade crest, but any precipitation amounts
would tend to be light. South to southwest flow will result in
warming temperatures with afternoon temperatures jumping back up
into the mid 60s to mid 70s Monday and Tuesday. Winds will be out
of the south- southwest and remain 5-15 mph. Tobin
&&
.AVIATION...
06Z TAFS: A cold front will sweep across the region tonight. Showers
are expected to develop from around the KLWS/KPUW area and extend
up toward KCOE after 12Z. There is a slight possibility for MVFR
conditions with these showers, but is not expected due to the
amount of dry air that exists at low levels. Winds will be breezy
across much of the region through Wednesday afternoon with gusts
up to between 20-30 mph possible. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 59 36 60 39 57 37 / 10 0 0 20 10 10
Coeur d`Alene 58 34 61 37 57 35 / 20 10 0 20 20 10
Pullman 56 33 59 38 55 35 / 30 0 10 20 10 10
Lewiston 63 37 66 43 62 40 / 30 0 0 20 20 10
Colville 62 34 63 37 60 36 / 20 10 0 30 20 20
Sandpoint 57 32 60 35 56 33 / 30 10 10 30 20 20
Kellogg 54 34 60 36 54 34 / 30 10 0 30 30 10
Moses Lake 65 37 65 39 63 38 / 0 0 0 10 10 10
Wenatchee 64 42 64 43 62 41 / 0 0 0 10 20 20
Omak 64 34 64 37 62 35 / 10 10 10 20 30 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
238 AM PDT WED APR 22 2015
.SYNOPSIS...
A cold front will move through the area and bring cooler weather
and breezy conditions today. More seasonal temperatures and off
and on showery conditions will linger through the remainder of the
work week. A slightly stronger weather disturbance will result in
scattered, mainly mountains rain and snow showers Thursday night
into the weekend. High pressure with warm temperatures and dry
conditions will return for the beginning of next week.
&&
.DISCUSSION...
Today through Thursday...The upper trough and associated cold
front will slide through the region today bringing a chance of
showers to the Inland Northwest. The front itself is moisture
starved but there is a band of moisture moving up from the south
ahead of the front. This may be enough to conjure up isolated to
scattered showers across the southeast zones and into the Idaho
panhandle mountains but a few hundredths of an inch of
precipitation is likely all we will see from passing showers. The
cooler more dense marine air is accelerating down the Cascade gap
valleys and into the basin and Palouse with gusts generally in the
25 to 35 mph range with some of the windier ridgetop locations
occasionally gusting to 45 mph. Expect breezy to windy conditions
to continue through late this evening then winds will start to
diminish after midnight.
The presence of the upper trough and more cloud cover will keep
daytime temperatures about 12 to 15 degrees cooler that yesterday.
Tonight a flat ridge will briefly move over the region and if we
get a decent period of clearing along with light winds, the
northern valleys could get quite chilly overnight. Some mid to
high clouds will spread across the region in advance of the next
Pacific trough and this may keep overnight temperatures from
falling too much below the freezing mark. For Thursday, expect a
mostly dry day between systems before the next chance of showers
pushes into the Cascades late in the day. Temperatures will be
close to seasonal normals. /Kelch
Thursday night through Tuesday...The models appear to be
converging on a similar solution with the upper level low
Thursday night through Saturday evening. That closed low is
expected to drop through the Gulf of Alaska then take a drunken
and wobbly course south and east through southern B.C. and
northern Washington, before opening into a wave and exiting to the
east on Sunday. This is quite a bit different then what we were
looking at 24 hours ago, and will result in a much drier forecast
for the weekend. Sunday through Tuesday guidance begins to show
some differences as high pressure builds back into the Pac NW
ahead of another incoming Pacific wave.
Thursday night through Sunday moisture and small embedded short
waves will wrap around the upper level low. There is some weak
surface based instability each afternoon. This all adds up to a
chance for showers at times through the period. While just about
anywhere could see showers, the focus, as is typical, will be for
the mountains surrounding the Basin and Palouse. Showers will be
spotty and inconsistent, but should be more prominent with
afternoon heating. Snow levels will result in some light snow
accumulations mainly above 4000 feet. Temperatures will be cool
compared to the past several days with temps in the 50s and lower
60s which is just on the cool side of normal. Expect mainly
southwest winds around 10 mph, but winds are expected to become
breezy on Sunday as the upper low moves out and high pressure
begins to build off the coast.
Sunday through Tuesday...All of the model guidance is showing the
ridge building in from the west Sunday afternoon then
strengthening Monday and Tuesday. The differences show up on just
how strong the ridge becomes and the location of the ridge axis.
Southwest flow will tap into deeper moisture, but it now looks
like the strong atmospheric river is much less potent. In addition
the ridge should push any moisture north of the Inland Northwest.
With that in mind we kept some low end pops for Sunday, but then
dried out the forecast through Tuesday. Some light rain will be
possible along the Cascade crest, but any precipitation amounts
would tend to be light. South to southwest flow will result in
warming temperatures with afternoon temperatures jumping back up
into the mid 60s to mid 70s Monday and Tuesday. Winds will be out
of the south- southwest and remain 5-15 mph. Tobin
&&
.AVIATION...
06Z TAFS: A cold front will sweep across the region tonight. Showers
are expected to develop from around the KLWS/KPUW area and extend
up toward KCOE after 12Z. There is a slight possibility for MVFR
conditions with these showers, but is not expected due to the
amount of dry air that exists at low levels. Winds will be breezy
across much of the region through Wednesday afternoon with gusts
up to between 20-30 mph possible. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 59 36 60 39 57 37 / 10 0 0 20 10 10
Coeur d`Alene 58 34 61 37 57 35 / 20 10 0 20 20 10
Pullman 56 33 59 38 55 35 / 30 0 10 20 10 10
Lewiston 63 37 66 43 62 40 / 30 0 0 20 20 10
Colville 62 34 63 37 60 36 / 20 10 0 30 20 20
Sandpoint 57 32 60 35 56 33 / 30 10 10 30 20 20
Kellogg 54 34 60 36 54 34 / 30 10 0 30 30 10
Moses Lake 65 37 65 39 63 38 / 0 0 0 10 10 10
Wenatchee 64 42 64 43 62 41 / 0 0 0 10 20 20
Omak 64 34 64 37 62 35 / 10 10 10 20 30 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
1058 PM PDT TUE APR 21 2015
.SYNOPSIS...
A cold front will move through the area and bring cooler weather
and breezy conditions late tonight and on into Wednesday. Cooler
temperatures and off and on showery conditions will linger on
through the remainder of the work week. A stronger weather
disturbance will result in widespread and possibly moderate
precipitation Sunday into Monday.
&&
.DISCUSSION...
Satellite imagery shows the mid level cold front beginning to push
into the Cascade Mtns late this evening. Water vapor imagery also
shows some enhancement ahead of this front across central OR and
moving up into central WA. The atmosphere is so dry across the
region that it is going to take another 6 hours or so before the
atmosphere moistens up enough that showers begin to pop up over
the area. The best mid level instability will be across the ID
Panhandle into extreme eastern portions of WA. This is where
models are showing the best chances for precip as that mid level
front cross east of the Cascades through the morning on Wednesday.
The NAM continues to be the most aggresive with a precip as it
shows a convective bullseye over the Northeast Blue Mtns and
extending into the Central Panhandle Mtns. The GFS, ECMWF and
even the HRRR show much less potential for precip with the
showers. This makes more sense as not much precip has fallen west
of the Cascades with the front, which is sign that there just
isn`t much moisture to work with. Shower coverage is expected to
be isolated to scattered.
There will also be a pronounced dry slot that moves in with the
front. This dry air will wrap into the region as the upper level
low pressure system tracks across the southern BC border. The cold
pool aloft is not that deep as well, so not expecting much in the
way of afternoon convection on Wednesday behind the front. The
main changes that were made to the forecast were to lower precip
chances a bit and mainly for Wednesday afternoon. I also lowered
temperatures some for tonight as well. The cold front will advect
in a considerable amount of cold air. Good cold air advection will
also result in breezy winds through tonight. Winds are already
getting fairly gusty in the lee of the Cascades. Expect these
winds to spread eastward into the basin and remain breezy through
Wednesday afternoon. /SVH
&&
.AVIATION...
06Z TAFS: A cold front will sweep across the region tonight. Showers
are expected to develop from around the KLWS/KPUW area and extend
up toward KCOE after 12Z. There is a slight possibility for MVFR
conditions with these showers, but is not expected due to the
amount of dry air that exists at low levels. Winds will be breezy
across much of the region through Wednesday afternoon with gusts
up to between 20-30 mph possible. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 45 59 36 60 38 58 / 10 20 10 10 20 10
Coeur d`Alene 42 59 34 61 37 58 / 10 30 10 0 20 20
Pullman 43 57 32 59 37 56 / 20 30 0 0 20 10
Lewiston 47 64 37 66 43 63 / 20 40 0 0 20 20
Colville 46 63 34 63 35 61 / 10 20 20 10 30 20
Sandpoint 42 57 32 60 35 56 / 10 30 20 10 30 20
Kellogg 41 55 34 60 34 55 / 0 40 10 10 30 30
Moses Lake 45 66 36 63 38 64 / 10 0 0 10 10 10
Wenatchee 45 65 41 63 42 63 / 10 0 0 10 10 20
Omak 43 64 33 63 36 62 / 10 10 10 10 20 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1201 AM CDT WED APR 22 2015
.UPDATE...
ISSUED AT 624 PM CDT TUE APR 21 2015
EVEN THOUGH WE ARE GETTING SOME OUR STRONGEST WIND GUSTS RIGHT
NOW...SOUNDINGS SHOW THAT WE WILL BE NOT MIXING AS DEEP DURING THE
NEXT HOUR. THIS MEANS THAT THESE STRONG WINDS WILL NOT LAST MUCH
LONGER. SINCE IT WOULD ONLY MEAN EXTENDING THE WIND ADVISORY BY 1
HOUR...DECIDED TO JUST LET IT EXPIRE AND REPLACE IT WITH A SPECIAL
WEATHER STATEMENT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 326 PM CDT TUE APR 21 2015
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO ALBERTA AND VERY DEEP
TROUGHING OVER THE FORECAST AREA INTO THE GREAT LAKES. WITHIN THIS
TROUGH WAS AN UPPER LOW OVER EASTERN LAKE SUPERIOR...A SHORTWAVE
DROPPING SOUTH TOWARDS I-90 IN THE FORECAST AREA...AND ANOTHER
SHORTWAVE OVER NORTHEAST MN. COOL TEMPERATURES ALOFT REFLECTED BY
500MB TEMPS OF -27 TO -33C PER 12Z RAOBS...DAYTIME HEATING...NEAR
SATURATED CONDITIONS BETWEEN 700-850MB AND THE AFOREMENTIONED
SHORTWAVES HELPING TO PRODUCE PLENTY OF SHOWERS ACROSS THE
REGION....ESPECIALLY ALONG AND NORTH OF I-94. TEMPERATURES HAVE
STRUGGLED TO RISE WITH CLOUDS...PRECIP AND 850MB TEMPS OF -3 TO
-7C. READINGS HAVE ONLY CLIMBED INTO THE MID 30S TO LOW 40S. THE
COLD TEMPERATURES HAVE SUPPORTED A MIX OF RAIN AND SNOW...WITH THE
SNOW CONFINED MORESO TO HIGHER ELEVATIONS AND TAYLOR/CLARK
COUNTIES. ON TOP OF THE COOL AIR...A TIGHT PRESSURE GRADIENT AND
925MB WINDS OF 25-35 KT HAS RESULTED IN WINDS GUSTING TO THE 925MB
SPEEDS...MAKING IT FEEL FALL-LIKE. THESE WINDS ARE JUST BELOW
ADVISORY CRITERIA.
THE OVERALL UPPER PATTERN CHANGES LITTLE IN THE NEXT 24 HOURS WITH
ONLY A SLIGHT DRIFT EASTWARD OF THE UPPER LOW AND TROUGHING. THIS
SLIGHT DRIFT LOOKS TO BE ENOUGH SUCH THAT MUCH OF THE SHORTWAVE AND
INSTABILITY INDUCED SHOWERS ON WEDNESDAY WILL FALL EAST OF THE
FORECAST AREA. HOWEVER...PORTIONS OF TAYLOR AND ADAMS COULD GET
CLIPPED IN THE AFTERNOON. GETTING BACK TO TONIGHT...GENERAL MODEL
CONSENSUS SUGGESTS THE LOSS OF DAYTIME HEATING WILL ALLOW SHOWER
ACTIVITY TO BECOME MORE ISOLATED THROUGH THE EVENING...EVENTUALLY
ENDING BY MIDNIGHT.
CLOUDS LOOK TO HOLD OVER MUCH OF THE FORECAST AREA TONIGHT...AIDED
BY A SURGE OF 850MB MOISTURE CURRENTLY IN NORTHWEST ONTARIO DROPPING
SOUTHWARD WITH THE SHORTWAVE IN NORTHEAST MN. SUBSIDENCE IN THE WAKE
OF THIS SHORTWAVE...COMBINED WITH 925-700MB WINDS BACKING A BIT MORE
WESTERLY ON WEDNESDAY...WILL HELP TO RESULT IN MORE SUNSHINE.
DESPITE THE CLOUDS TONIGHT...AND A PERSISTENT BREEZE...TEMPERATURES
WILL STILL FALL AS THAT SHORTWAVE IN NORTHEAST MN DRAGS COLDER AIR
INTO THE FORECAST AREA. BY 12Z WED...850MB TEMPS ARE PROGGED TO DROP
TO -8 TO -11C...OR ALMOST 2 STANDARD DEVIATIONS BELOW NORMAL.
GUIDANCE LOWS IN THE MID 20S TO LOW 30S SEEM REASONABLE. HAVING MORE
SUNSHINE ON WEDNESDAY WILL HELP PRODUCE A WARMER DAY THAN
TODAY...ALBEIT STILL WELL BELOW NORMAL GIVEN 850MB TEMPS ONLY
CLIMBING TO -2 TO -7C BY 00Z THU. MOST LOCATIONS SHOULD CLIMB INTO
THE 40S...WITH LOW 50S LIKELY IN RIVER VALLEYS AND THE SOUTHWEST
PORTION OF THE FORECAST AREA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 PM CDT TUE APR 21 2015
THE UPPER FLOW PATTERN LOOKS TO BECOME MORE PROGRESSIVE THROUGH THE
END OF THE WEEK IN RESPONSE TO A DEEP UPPER TROUGH APPROACHING THE
PACIFIC NORTHWEST. THIS WILL HELP TO PUSH THE UPPER RIDGING AND
WARMER AIR OVER THE WESTERN U.S. TOWARDS THE FORECAST AREA. 850MB
TEMPS DO NOT CHANGE A WHOLE LOT WED NIGHT...BUT MORE IMPRESSIVE WARM
ADVECTION COMES IN FOR THU WITH 850MB TEMPS REACHING 0 TO -2C BY 00Z
FRI...AND 0 TO 4C BY 00Z SAT. LOW PRECIPITABLE WATER ON
THURSDAY...AROUND 0.1 INCHES...SHOULD HELP TO TANK DEWPOINTS AND
RESULTING RHS. COMBINED WITH A DRYING DAY ON WEDNESDAY AND A 10-15
MPH NORTHWEST BREEZE...FIRE WEATHER COULD BE A CONCERN. SEE FIRE
WEATHER SECTION BELOW.
FOR FRIDAY INTO SATURDAY...AN UPPER LOW CURRENTLY NEAR LOS ANGELES
IS PROGGED TO LIFT THROUGH THE CENTRAL PLAINS AND TRACK EASTWARD
ACROSS ILLINOIS. ALTHOUGH THIS TRACK IS SOUTH OF THE FORECAST
AREA...MOISTURE ADVECTION SPREADS NORTHWARD AHEAD OF THE UPPER LOW
TO HELP PRODUCE SOME RAIN. THE SPEED HAS SLOWED DOWN A BIT...AND AS
A RESULT DELAYED THE SPREADING OF CHANCES OF RAINFALL EASTWARD ON
FRIDAY. FURTHER DELAYS MAY BE NEEDED. RAIN CHANCES SPREAD ACROSS THE
FORECAST AREA FRIDAY NIGHT AND THEN SHIFT TO SOUTH OF I-90 ON
SATURDAY...RESULTING FROM EASTERLY FLOW DRAGGING MORE DRY AIR INTO
NORTHERN SECTIONS. OVERALL APPEARS TO BE A LIGHT RAIN...WITH THE
HEAVIER RAIN TO THE SOUTH TIED TO THE UPPER LOW FORCING.
DRIER WEATHER LOOKS TO FOLLOW SATURDAY NIGHT AND SUNDAY AS UPPER
RIDGING BUILDS BACK INTO THE FORECAST AREA FROM THE WEST.
TEMPERATURES SHOULD REBOUND CLOSER TO NORMAL AS WELL WITH MORE SUN
ON SUNDAY AND 850MB TEMPS IN THE 0-4C RANGE.
FOR EARLY NEXT WEEK UNCERTAINTY BEGINS TO INCREASE. NOT SO MUCH ON
THE UPPER PATTERN WHERE MODELS ADVERTISE TROUGHING DEVELOPING FROM
THE NORTHEAST U.S. INTO THE SOUTHEAST U.S....BUT WITH PRECIPITATION
CHANCES AS THIS TROUGH DEVELOPS. THE 21.12Z GFS HAS A SHORTWAVE
TROUGH DROPPING THROUGH THE REGION TO BRING PRECIPITATION TO THE
AREA. MEANWHILE THE 21.12Z ECMWF AND CANADIAN SUGGEST A DRY
PERIOD AS HIGH PRESSURE DOMINATES AT THE SURFACE...WITH THE
AFOREMENTIONED SHORTWAVE TROUGH FALLING APART. FOR NOW HAVE WENT
WITH THE CONSENSUS AND HAVE 20-30 PERCENT CHANCES. HOW THIS
SHORTWAVE TROUGH EVOLVES ALSO HAS AN IMPACT ON TEMPERATURES. IN
THE CASE OF THE 21.12Z GFS...IT SUGGESTS 850MB TEMPS PLUNGE TO
AROUND -4C BY 12Z TUE...ABOUT 8C COLDER THAN THE ECMWF. ALSO
FOLLOWED CONSENSUS HERE FOR NOW WITH TEMPS JUST SHY OF NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1200 AM CDT TUE APR 21 2015
A 5 TO 6K BROKEN DECK OF CLOUDS WILL PERSIST ACROSS THE AREA
THROUGH THE OVERNIGHT AND WEDNESDAY MORNING. SCATTERED SNOW
SHOWERS WILL PERSIST DURING THIS TIME PERIOD...BUT ANY VISIBILITIY
RESTRICTIONS WOULD ONLY LAST A FEW MINUTES AT MOST. AS DRIER AIR
MOVES INTO THE REGION AND THE FLOW BECOMES ANTICYCLONIC...EXPECT
SKIES TO QUICKLY CLEAR AT BOTH TAF SITES.
&&
.FIRE WEATHER...
ISSUED AT 326 PM CDT TUE APR 21 2015
AFTER SOME RECENT COOL/WET DAYS...CONDITIONS LOOK TO DRY OUT AGAIN
WEDNESDAY AND THURSDAY. RELATIVE HUMIDITIES ARE EXPECTED TO DROP
INTO THE 20S ON WEDNESDAY AND MAY EVEN DROP BELOW 20 PERCENT IN A
FEW SOUTHEAST MN LOCATIONS ON THURSDAY. FIGURE MUCH OF WEDNESDAY
WILL BE A DRYING DAY FOR FUELS GIVEN THE WET WEATHER...WITH A 15
TO 25 MPH NORTHWEST BREEZE AIDING IN THE DRYING. THEREFORE
THURSDAY WOULD APPEAR TO BE THE MORE CONCERNING DAY...THOUGH WINDS
LOOK LIGHTER IN THE 10 TO 15 MPH RANGE. NEVERTHELESS...WELL HAVE
TO KEEP A CLOSE EYE ON THURSDAY AND SEE TOO WHERE ALL THE
VEGETATION STANDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BOYNE
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1010 AM EDT WED APR 22 2015
.DISCUSSION...
A WEAK STATIONARY FRONT OVER THE S PENINSULA IS PROVIDING THE FOCUS
FOR POCKETS OF LIGHT RAIN STREAMING ACRS THE LAKE OKEECHOBEE REGION.
FURTHER NORTH...SAT PICS SHOW A SLUG OF SIGNIFICANTLY DRIER AIR
PUSHING INTO THE I-4 CORRIDOR...LATEST RAP ANALYSIS SHOWS H100-H70
MEAN RH VALUES AOB 40PCT...H85-H50 VALUES AOB 30PCT. MORNING
SOUNDING DEPICT THE POSITION OF THE FRONT QUITE WELL...HIGH PWAT AIR
ARND 2.0" AT KMFL...DECREASING TO ARND 1.3" AT KTBW/KXMR...THEN TO
0.8" AT KJAX/KTAE.
RAP ANALYSIS ALSO SHOWING LITTLE IN THE WAY OF MID LVL ENERGY IN THE
H85-H50 LVL VORT FIELD...A WEAKLY CONVERGENT H30-H20 LYR DESPITE THE
PRESENCE OF A 120KT ZONAL JET OVER THE DEEP SOUTH...AND H70-H50
LAPSE RATES BTWN 5.0-5.5C/KM STEEPENING FROM NORTH TO SOUTH.
AIRMASS IS A BIT TOO DRY/STABLE TO SUPPORT PRECIP MUCH FARTHER N
THAN SR60...WILL REDUCE POPS ACCORDINGLY TO AOB 20PCT. S OF SR60...
WILL KEEP SCT SHRAS/ISOLD TSRAS IN THE FCST GIVEN THE DEEPER
MOISTURE AND BETTER SFC/LOW LVL FRONTAL CONVERGENCE.
&&
.AVIATION...THRU 23/12Z
SFC WINDS: THRU 22/16Z...N/NW 4-7KTS. BTWN 22/16Z-22/19Z...BCMG E/NE
7-10KTS CONTG THRU 23/02Z. AFT 23/02Z...VRBL AOB 3KTS.
VSBYS/WX/CIGS: PREVAILING VFR ALL SITES WITH CIGS AOA FL100. BTWN
22/17Z-23/01Z...BRIEF MVFR SHRAS S OF KVRB-KSRQ.
&&
.MARINE...
FAVORABLE MARINE CONDITIONS TO CONTINUE AS A WEAK FRONTAL BOUNDARY
WASHES OUT OVER S FL AND NRN BAHAMAS. RIDGE AXIS OVER THE FL STRAITS
WILL GENERATE A LIGHT TO GENTLE WRLY BREEZE ACRS THE LCL ATLC...BCMG
E/SE NEAR THE COAST BY EARLY AFTN WITH THE FORMATION OF THE EAST
COAST SEA BREEZE. SEAS AOB 2FT NEARSHORE AND 2-3FT OFFSHORE.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...VOLKMER
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
1005 AM EDT WED APR 22 2015
.UPDATE...
A FRONTAL BOUNDARY OVER SOUTH FLORIDA THIS MORNING WILL REMAIN
NEARLY STATIONARY THIS AFTERNOON KEEPING THE DEEP TROPICAL
MOISTURE IN PLACE OVER SOUTH FLORIDA. THE WEST AND EAST COAST SEA
BREEZES SHOULD ALSO DEVELOP THIS AFTERNOON WITH THE WEST COAST
SEA BREEZE PUSHING ACROSS THE AREA. THIS WILL KEEP THE BEST
CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON OVER THE
EASTERN AREAS OF SOUTH FLORIDA WHERE THE SEA BREEZES COLLIDE.
THEREFORE...THE POPS WILL REMAIN IN THE CHANCE TO LIKELY RANGE
WITH THE BEST COVERAGE OVER THE EASTERN AREAS OF SOUTH FLORIDA.
THERE COULD ALSO BE A FEW STRONG STORMS THIS AFTERNOON ESPECIALLY
OVER THE EASTERN AREAS OF SOUTH FLORIDA...AS A SHORT WAVE WILL BE
MOVING THROUGH THE AREA FROM THE GULF OF MEXICO. THE PRIMARY
IMPACTS FROM THE STRONGEST STORMS WILL BE GUSTY WINDS, SMALL HAIL,
HEAVY RAINFALL, AND FREQUENT LIGHTNING STRIKES.
REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES
ARE PLANNED AT THIS TIME.
&&
.UPDATE...54/BNB
.PREV DISCUSSION... /ISSUED 742 AM EDT WED APR 22 2015/
AVIATION...
A LINGERING BOUNDARY, THAT WAS A COLD FRONT, WILL HELP TO TRIGGER
CONVECTIVE SHOWERS AND THUNDERSTORMS THROUGH THE DAY, AND INTO THE
EVENING HOURS. EVEN SO, STILL EXPECT VFR CONDITIONS TO BE
PREDOMINATE, WITH BRIEF IFR POSSIBLE. THE IFR OCCURRENCES WOULD
BE TOO BRIEF AND TOO UNCERTAIN TO MENTION IN TAFS AT THIS TIME.
&&
PREV DISCUSSION... /ISSUED 348 AM EDT WED APR 22 2015/
DISCUSSION...
THE RECENT UPTICK IN STRONG THUNDERSTORMS ACROSS THE REGION THIS
WEEK, IS PARTLY DUE TO THE POSITION OF A ZONAL UPPER JET FROM THE
US/MEXICO BORDER THROUGH THE FLORIDA PANHANDLE. SOUTH FLORIDA HAS
BEEN ON THE SOUTHERN EDGE OF THIS WESTERLY FLOW. THE STRENGTH OF THE
UPPER JET IS UNUSUAL, ROUGHLY 3 STANDARD DEVIATIONS ABOVE NORMAL,
AND IS DRIVEN NOT ONLY BY THE BLOCKY H5 PATTERN ACROSS NORTH
AMERICA, BUT ALSO BY THE UPPER RIDGE OVER THE CARIBBEAN WHICH HAS
DELIVERED MANY OPPRESSIVELY WARM DAYS RECENTLY. HOWEVER, TODAY
CLOUDS WILL BE A MITIGATING FACTOR WITH REGARDS TO STRONG CONVECTIVE
INITIATION, AND PERHAPS THIS IS REFLECTED IN NOT TOO IMPRESSIVE CAPE
VALUES FROM MODEL SOUNDINGS. IN CONTRAST, RUC13 SOUNDINGS DO HAVE 0-
6KM SHEAR VALUES NEAR 45 M/S AND H7-H5 LAPSE RATES 6C/KM AT MIA BY
LATE MORNING. A SHRTWV ARRIVING FROM THE GULF OVERNIGHT HAS KEPT
NORTHERN ZONES WET, AND MOISTURE WILL CONTINUE TO BE ABUNDANT SOUTH
OF THE DWINDLING FRONT OVER LAKE OKEECHOBEE. NUMEROUS SHOWERS AND
THUNDERSTORMS, NOW ENTERING THE FLORIDA STRAITS, MAY ALSO COMPLICATE
MATTERS THIS MORNING. ANY BREAKS IN THE CLOUDINESS THIS AFTERNOON,
CAN VERY WELL LEAD TO STRONG THUNDERSTORMS. MODELS FOCUSING HIGHEST
POP ACROSS BROWARD AND MIAMI-DADE TODAY. PWATS AROUND 2" AND LITTLE
DIRECTIONAL SHEAR THROUGH THE COLUMN WILL MAKE TRAINING OF STORMS
AND VERY HEAVY RAINFALL POSSIBLE.
THURSDAY LOOKS SIMILAR TO TODAY, WITH THE ONLY DIFFERENCE A SLIGHT
BACKING OF MID AND UPPER LEVEL WINDS. THE VERY SUBTLE CAA THIS
PROVIDES ALOFT MAY ENHANCE LAPSE RATES A TAD. MORNING CLOUDS MAY NOT
BE AS MUCH OF AN ISSUE AS THEY ARE TODAY, AS PRECIP TONIGHT LOOKS
LESS COMPARED TO WHAT IS HAPPENING THIS MORNING.
HIGH PRESSURE MOVING INTO THE SOUTHEASTERN CONUS SHOULD DELIVER A
SLUG OF RELATIVELY DRIER AIR IN THE MIDLEVELS ON FRIDAY. THIS
COMBINED WITH SLIGHTLY WARMING H5 TEMPS SHOULD LEAD TO LESS COVERAGE
AND STORMS FOCUSED MORE INLAND WITH CONVERGING SEA BREEZES. EVEN
DRIER AIR ARRIVES THIS WEEKEND AND PWATS CONTINUE TO SLOWLY FALL.
HOWEVER, RISING H85 TEMPS TO +19C MEAN 90F POTENTIALLY FOR ALL THE
BIG CITIES AGAIN, ESPECIALLY ON SUNDAY. THE QUIETER PATTERN SHOULD
LAST INTO EARLIER NEXT WEEK. ALTHOUGH SEVERAL DAYS AWAY, BOTH THE
GFS/ECMWF ARE BULLISH REGARDING A DEEP EASTERN TROUGH AND A NEARING
COLD FRONT AT THE END OF THE FORECAST.
MARINE...
ALTHOUGH WINDS WILL REMAIN BELOW 15 KTS AND SEAS NO GREATER THAN 3
FEET THROUGH THE FORECAST, SHOWERS AND THUNDERSTORMS MAY BE NUMEROUS
AT TIMES TODAY AND THURSDAY. SOME OF WHICH COULD BE STRONG. WIND
DIRECTION WILL BECOME INCREASINGLY SW AND W THROUGH THE WEEKEND FROM
10-15 KTS BY SUNDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 70 88 72 / 60 30 50 20
FORT LAUDERDALE 85 74 87 74 / 70 40 50 20
MIAMI 87 74 90 75 / 70 40 50 20
NAPLES 84 72 86 74 / 40 10 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...54/BNB
LONG TERM....21/KM
AREA FORECAST DISCUSSION
NWS MIAMI FL
742 AM EDT WED APR 22 2015
.AVIATION...
A LINGERING BOUNDARY, THAT WAS A COLD FRONT, WILL HELP TO TRIGGER
CONVECTIVE SHOWERS AND THUNDERSTORMS THROUGH THE DAY, AND INTO THE
EVENING HOURS. EVEN SO, STILL EXPECT VFR CONDITIONS TO BE
PREDOMINATE, WITH BRIEF IFR POSSIBLE. THE IFR OCCURRENCES WOULD
BE TOO BRIEF AND TOO UNCERTAIN TO MENTION IN TAFS AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 348 AM EDT WED APR 22 2015/
DISCUSSION...
THE RECENT UPTICK IN STRONG THUNDERSTORMS ACROSS THE REGION THIS
WEEK, IS PARTLY DUE TO THE POSITION OF A ZONAL UPPER JET FROM THE
US/MEXICO BORDER THROUGH THE FLORIDA PANHANDLE. SOUTH FLORIDA HAS
BEEN ON THE SOUTHERN EDGE OF THIS WESTERLY FLOW. THE STRENGTH OF THE
UPPER JET IS UNUSUAL, ROUGHLY 3 STANDARD DEVIATIONS ABOVE NORMAL,
AND IS DRIVEN NOT ONLY BY THE BLOCKY H5 PATTERN ACROSS NORTH
AMERICA, BUT ALSO BY THE UPPER RIDGE OVER THE CARIBBEAN WHICH HAS
DELIVERED MANY OPPRESSIVELY WARM DAYS RECENTLY. HOWEVER, TODAY
CLOUDS WILL BE A MITIGATING FACTOR WITH REGARDS TO STRONG CONVECTIVE
INITIATION, AND PERHAPS THIS IS REFLECTED IN NOT TOO IMPRESSIVE CAPE
VALUES FROM MODEL SOUNDINGS. IN CONTRAST, RUC13 SOUNDINGS DO HAVE 0-
6KM SHEAR VALUES NEAR 45 M/S AND H7-H5 LAPSE RATES 6C/KM AT MIA BY
LATE MORNING. A SHRTWV ARRIVING FROM THE GULF OVERNIGHT HAS KEPT
NORTHERN ZONES WET, AND MOISTURE WILL CONTINUE TO BE ABUNDANT SOUTH
OF THE DWINDLING FRONT OVER LAKE OKEECHOBEE. NUMEROUS SHOWERS AND
THUNDERSTORMS, NOW ENTERING THE FLORIDA STRAITS, MAY ALSO COMPLICATE
MATTERS THIS MORNING. ANY BREAKS IN THE CLOUDINESS THIS AFTERNOON,
CAN VERY WELL LEAD TO STRONG THUNDERSTORMS. MODELS FOCUSING HIGHEST
POP ACROSS BROWARD AND MIAMI-DADE TODAY. PWATS AROUND 2" AND LITTLE
DIRECTIONAL SHEAR THROUGH THE COLUMN WILL MAKE TRAINING OF STORMS
AND VERY HEAVY RAINFALL POSSIBLE.
THURSDAY LOOKS SIMILAR TO TODAY, WITH THE ONLY DIFFERENCE A SLIGHT
BACKING OF MID AND UPPER LEVEL WINDS. THE VERY SUBTLE CAA THIS
PROVIDES ALOFT MAY ENHANCE LAPSE RATES A TAD. MORNING CLOUDS MAY NOT
BE AS MUCH OF AN ISSUE AS THEY ARE TODAY, AS PRECIP TONIGHT LOOKS
LESS COMPARED TO WHAT IS HAPPENING THIS MORNING.
HIGH PRESSURE MOVING INTO THE SOUTHEASTERN CONUS SHOULD DELIVER A
SLUG OF RELATIVELY DRIER AIR IN THE MIDLEVELS ON FRIDAY. THIS
COMBINED WITH SLIGHTLY WARMING H5 TEMPS SHOULD LEAD TO LESS COVERAGE
AND STORMS FOCUSED MORE INLAND WITH CONVERGING SEA BREEZES. EVEN
DRIER AIR ARRIVES THIS WEEKEND AND PWATS CONTINUE TO SLOWLY FALL.
HOWEVER, RISING H85 TEMPS TO +19C MEAN 90F POTENTIALLY FOR ALL THE
BIG CITIES AGAIN, ESPECIALLY ON SUNDAY. THE QUIETER PATTERN SHOULD
LAST INTO EARLIER NEXT WEEK. ALTHOUGH SEVERAL DAYS AWAY, BOTH THE
GFS/ECMWF ARE BULLISH REGARDING A DEEP EASTERN TROUGH AND A NEARING
COLD FRONT AT THE END OF THE FORECAST.
MARINE...
ALTHOUGH WINDS WILL REMAIN BELOW 15 KTS AND SEAS NO GREATER THAN 3
FEET THROUGH THE FORECAST, SHOWERS AND THUNDERSTORMS MAY BE NUMEROUS
AT TIMES TODAY AND THURSDAY. SOME OF WHICH COULD BE STRONG. WIND
DIRECTION WILL BECOME INCREASINGLY SW AND W THROUGH THE WEEKEND FROM
10-15 KTS BY SUNDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 70 88 72 / 60 20 50 20
FORT LAUDERDALE 85 74 87 74 / 60 30 50 20
MIAMI 87 74 90 75 / 60 30 50 20
NAPLES 84 72 86 74 / 40 20 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...21/KM
LONG TERM....21/KM
AVIATION...13/SI
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1038 AM CDT WED APR 22 2015
.DISCUSSION...
WEAKENING MCS MOVG INTO RED RIVER VALLEY. GOOD DAYTIME HEATING
WILL CONTINUE AHEAD OF THE DECAYING SYSTEM OUTFLOW THAT WILL PUSH
EASTWARD INTO SW AR/NW TX AND NW LA THIS AFTN. BETWEEN AIRMASS
RECOVERY ACROSS NORTHERN AREAS NEAR THIS MCS...AND MARGINAL
MOISTURE IN UNSTABLE AIRMASS ACROSS REST OF AREA...EXPECT STG
CONVECTIVE REDEVELOPMENT TO OCCUR LATE AFTN/EARLY EVE.
THUS...LOWERED POPS SLIGHTLY TO 20 AND 30 PERCENT FOR MOST OF
NORTHERN LA...AND PORTIONS OF NE TX ALONG AND SOUTH OF I-20.
ALSO RAISED TEMPS SLIGHTLY TO LOWER/MID 80S ACROSS ROUGHLY THESE
SAME AREAS WHERE POPS HAVE BEEN LOWERED./VII/.
&&
.PREV DISCUSSION... /ISSUED 538 AM CDT WED APR 22 2015/
DISCUSSION...
AIR MASS MODIFICATION IS UNDERWAY THIS MORNING...WITH AN EXTENSIVE
BAND OF 5-6KFT CIGS HAVING DEVELOPED/SPREAD ENE ALONG AND S OF THE
I-20 CORRIDOR OF N LA/E TX. LOW LEVEL WARM/MOISTURE ADVECTION WILL
CONTINUE TODAY...AS A SRLY LOW LEVEL FLOW INCREASES...AHEAD OF
SFC LOW PRESSURE THAT WILL DEEPEN BY AFTERNOON ALONG THE DRY LINE
OVER NW TX. THIS WILL DRIVE A WARM FRONT NWD TO NEAR THE RED RIVER
OF N TX ESE ACROSS NE TX AND TO NEAR THE AR/LA LINE BY AFTERNOON.
MEANWHILE...A WEAK COLD FRONT WILL DRIFT S TODAY BEFORE
TEMPORARILY BECOMING STATIONARY FROM SRN OK INTO CNTRL AR. THE
MORNING WATER VAPOR IMAGERY REVEALS A SHORTWAVE ROUNDING THE
BACKSIDE OF A LARGE UPPER CLOSED LOW/ATTENDENT LONGWAVE TROUGH
EXTENDING FROM THE NRN GREAT LAKES SW THROUGH THE MIDWEST INTO THE
OK/TX PANHANDLE. THIS SHORTWAVE HAS BEEN DRIVING AN INCREASE IN
ELEVATED CONVECTION ALONG THE FRONT OVER WRN OK...WHICH SHOULD
CONTINUE TO SPREAD SSE ALONG THE FRONTAL ZONE THIS MORNING.
ADDITIONAL REDEVELOPMENT SHOULD OCCUR LATER TODAY AS CONVERGENCE
INCREASES ALONG THE TRIPLE POINT NEAR THE RED RIVER...AND LARGE
SCALE FORCING INCREASES ALONG A SECONDARY SHORTWAVE ON THE WATER
VAPOR IMAGERY OVER SRN NM THAT WILL LIFT NE INTO THE TX PANHANDLE
ATOP THE FLAT SRN PLAINS RIDGE AND ACROSS THE RED RIVER VALLEY.
THE AIR MASS ACROSS THE WARM SECTOR IS EXPECTED TO BECOME
MODERATELY UNSTABLE THIS AFTERNOON...CHARACTERIZED BY MLCAPES OF
1500-2500 J/KG AND STEEP LAPSE RATES. IT REMAINS TO BE SEEN THOUGH
WHETHER THE CURRENT WRN OK CONVECTION MAY HELP INITIATE CONVECTION
EARLIER OVER THE RED RIVER VALLEY...BEFORE MAX DESTABILIZATION
OCCURS...THUS TAPERING THE POTENTIAL INSTABILITY. THE 00Z PROGS
ARE NOT IN GOOD AGREEMENT AT ALL IN REGARDS TO CONVECTION
PLACEMENT/TIMING...ALTHOUGH THE NEW 06Z NAM HAS TRENDED CLOSER TO
THE GFS SOLUTION WITH CONVECTION INCREASING ALONG THE WARM FRONT
OVER NE TX DURING PEAK HEATING. MEANWHILE...THE HRRR IS SUGGESTING
LITTLE IF ANY DEVELOPMENT THIS AFTERNOON NEAR THE TRIPLE
POINT...WITH MORE WIDESPREAD CONVECTION DEVELOPING E OF I-35
ACROSS ECNTRL TX BY MID TO LATE AFTERNOON. NEEDLESS TO
SAY...CONFIDENCE IS LOWER TODAY THAN TUESDAY IN REGARDS TO
CONVECTION INITIATION AND PLACEMENT.
DID MAINTAIN HIGH CHANCE POPS WITH SVR WORDING THIS AFTERNOON NW
OF THE I-30 CORRIDOR ALONG/JUST N OF THE WARM FRONT...TAPERING
CHANCE POPS DOWN A TAD FARTHER E WHERE FRONTAL CONVERGENCE IS A
BIT WEAKER AND THIS REGION IS FARTHER REMOVED FROM THE TWO LOBES
OF SHORTWAVE ENERGY TO OUR N AND W. AN MCS MAY DEVELOP THIS
EVENING ALONG THE RED RIVER VALLEY AND SHIFT ESE ALONG THE FRONT
TONIGHT /PER THE CONSISTENT GFS SOLUTION AND TO SOME EXTENT THE
ECMWF/...WITH THE THREAT OF DAMAGING WINDS/LARGE HAIL POSSIBLE.
DID CONTINUE MENTION OF SVR OVERNIGHT AREAWIDE GIVEN THE
UNCERTAINTY...ALTHOUGH THIS THREAT SHOULD DIMINISH LATE WITH THE
STABILIZING BNDRY LYR. THE SHORT TERM PROGS ALSO SUGGEST A
SLIGHTLY FASTER MOVEMENT OF THE COLD FRONT AS IT BEGINS TO
BACKDOOR SW INTO SE OK/SW AR OVERNIGHT...BEFORE PULLING UP
STATIONARY OVER N LA/E TX THURSDAY. WEAK ISENTROPIC ASCENT ATOP
THE BNDRY MAY RESULT IN SCT CONVECTION DURING THE DAY...ALTHOUGH
THE LACK OF UPPER LEVEL ENERGY SHOULD KEEP QPF AMOUNTS LIGHT. IN
ADDITION...MESOSCALE BNDRYS FROM CONVECTION THIS AFTERNOON AND
TONIGHT MAY PLAY A ROLE IN CONVECTION INITIATION THURSDAY ACROSS
THE WARM SECTOR S OF THE FRONT. BUT ATTM...CONFIDENCE IS LOW IN
REGARDS TO THE PLACEMENT OF THE SVR THREAT...THUS HAVE REMOVED SVR
MENTION FROM THE FORECAST THURSDAY...ALTHOUGH CAN/T RULE OUT AN
ISOLATED SVR STORM WITHIN THE MODERATELY UNSTABLE AIR MASS.
WILL BE WATCHING THE CLOSED SRN CA UPPER LOW AS IT EJECTS NE
ACROSS THE FOUR CORNERS REGION AND OPENS UP THURSDAY
NIGHT...ENTERING THE SRN PLAINS FRIDAY. THE WILL SET UP A STRONG
SW FLOW ALOFT...WITH A 70-80KT MID LEVEL SPEED MAX EJECTING OVER
THE SRN PLAINS FRIDAY AFTERNOON. THIS WILL RESULT IN AN INCREASING
SSWRLY LOW LEVEL FLOW THURSDAY NIGHT/FRIDAY MORNING...THUS LIFTING
THE STATIONARY FRONT BACK N AS A WARM FRONT ACROSS OK/AR FRIDAY
AND HENCE BROADING THE WARM SECTOR. THE W TX DRYLINE WILL MIX E
INTO ERN OK TO JUST W OF THE I-35 CORRIDOR OF CNTRL TX FRIDAY
EVENING...WITH BROAD DIFFLUENCE ALOFT CONTRIBUTING TO SCT TO
NUMEROUS CONVECTION AREAWIDE ESPECIALLY DURING PEAK HEATING. LOW
LEVEL WINDS DO VEER MORE ACROSS THE REGION WELL E OF THE DRYLINE
FRIDAY...WITH A MORE UNIDIRECTIONAL FLOW NOTED ABOVE 850MB. GIVEN
THE STRONG DEEP LYR SHEAR AND MODERATE MLCAPES EXPECTED TO BE IN
PLACE...A MORE PRONOUNCED SVR THREAT WILL BE POSSIBLE WITH
DAMAGING WINDS/ISOLATED TORNADOES. MID LEVEL DRY AIR SHOULD ADVECT
ENE AHEAD OF THE EJECTING TROUGH FRIDAY EVENING...THUS TAPERING
THE CONVECTION FROM W TO E OVERNIGHT...WITH THE DRYLINE PULLING UP
STATIONARY JUST W OF THE REGION. THIS BNDRY SHOULD MIX E ACROSS
THE REGION SATURDAY AS WRLY WINDS INCREASE BENEATH THE MIDWEST SFC
CYCLONE...RESULTING IN PERHAPS THE WARMEST TEMPS SO FAR THIS
SRPING SEASON AS READING CLIMB WELL INTO THE MID 80S AND POSSIBLY
90 DEGREES OVER PORTIONS OF E TX/N LA.
UPPER RIDGING SHOULD AMPLIFY OVER THE CNTRL CONUS BY SUNDAY BEFORE
THE NEXT CLOSED LOW DIGS SE INTO THE SRN ROCKIES SUNDAY BEFORE
MOVING INTO THE SRN PLAINS MONDAY. THIS COULD RESULT IN ANOTHER
SVR THREAT FOR THE REGION BY THE MONDAY/TUESDAY
TIMEFRAME...ALTHOUGH DISCREPENCIES IN TIMING AMONGST THE FASTER
GFS/SLOWER ECMWF PRECLUDES A HIGHER CONFIDENCE ATTM. HOWEVER...THE
PROGS DO CONVERGE ON A PATTERN CHANGE BY MID AND LATE WEEK...WITH COOLER
AND DRIER CONDITIONS SPILLING S ACROSS THE ERN TWO-THIRDS OF THE
CONUS.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 82 64 77 67 / 30 70 40 30
MLU 83 63 77 64 / 20 70 40 20
DEQ 76 58 67 58 / 50 70 40 40
TXK 77 60 71 62 / 40 70 40 30
ELD 80 60 71 60 / 30 70 40 30
TYR 79 65 81 69 / 40 60 30 40
GGG 80 65 80 69 / 30 60 30 40
LFK 84 68 85 71 / 30 50 30 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
538 AM CDT WED APR 22 2015
.DISCUSSION...
AIR MASS MODIFICATION IS UNDERWAY THIS MORNING...WITH AN EXTENSIVE
BAND OF 5-6KFT CIGS HAVING DEVELOPED/SPREAD ENE ALONG AND S OF THE
I-20 CORRIDOR OF N LA/E TX. LOW LEVEL WARM/MOISTURE ADVECTION WILL
CONTINUE TODAY...AS A SRLY LOW LEVEL FLOW INCREASES...AHEAD OF
SFC LOW PRESSURE THAT WILL DEEPEN BY AFTERNOON ALONG THE DRY LINE
OVER NW TX. THIS WILL DRIVE A WARM FRONT NWD TO NEAR THE RED RIVER
OF N TX ESE ACROSS NE TX AND TO NEAR THE AR/LA LINE BY AFTERNOON.
MEANWHILE...A WEAK COLD FRONT WILL DRIFT S TODAY BEFORE
TEMPORARILY BECOMING STATIONARY FROM SRN OK INTO CNTRL AR. THE
MORNING WATER VAPOR IMAGERY REVEALS A SHORTWAVE ROUNDING THE
BACKSIDE OF A LARGE UPPER CLOSED LOW/ATTENDENT LONGWAVE TROUGH
EXTENDING FROM THE NRN GREAT LAKES SW THROUGH THE MIDWEST INTO THE
OK/TX PANHANDLE. THIS SHORTWAVE HAS BEEN DRIVING AN INCREASE IN
ELEVATED CONVECTION ALONG THE FRONT OVER WRN OK...WHICH SHOULD
CONTINUE TO SPREAD SSE ALONG THE FRONTAL ZONE THIS MORNING.
ADDITIONAL REDEVELOPMENT SHOULD OCCUR LATER TODAY AS CONVERGENCE
INCREASES ALONG THE TRIPLE POINT NEAR THE RED RIVER...AND LARGE
SCALE FORCING INCREASES ALONG A SECONDARY SHORTWAVE ON THE WATER
VAPOR IMAGERY OVER SRN NM THAT WILL LIFT NE INTO THE TX PANHANDLE
ATOP THE FLAT SRN PLAINS RIDGE AND ACROSS THE RED RIVER VALLEY.
THE AIR MASS ACROSS THE WARM SECTOR IS EXPECTED TO BECOME
MODERATELY UNSTABLE THIS AFTERNOON...CHARACTERIZED BY MLCAPES OF
1500-2500 J/KG AND STEEP LAPSE RATES. IT REMAINS TO BE SEEN THOUGH
WHETHER THE CURRENT WRN OK CONVECTION MAY HELP INITIATE CONVECTION
EARLIER OVER THE RED RIVER VALLEY...BEFORE MAX DESTABILIZATION
OCCURS...THUS TAPERING THE POTENTIAL INSTABILITY. THE 00Z PROGS
ARE NOT IN GOOD AGREEMENT AT ALL IN REGARDS TO CONVECTION
PLACEMENT/TIMING...ALTHOUGH THE NEW 06Z NAM HAS TRENDED CLOSER TO
THE GFS SOLUTION WITH CONVECTION INCREASING ALONG THE WARM FRONT
OVER NE TX DURING PEAK HEATING. MEANWHILE...THE HRRR IS SUGGESTING
LITTLE IF ANY DEVELOPMENT THIS AFTERNOON NEAR THE TRIPLE
POINT...WITH MORE WIDESPREAD CONVECTION DEVELOPING E OF I-35
ACROSS ECNTRL TX BY MID TO LATE AFTERNOON. NEEDLESS TO
SAY...CONFIDENCE IS LOWER TODAY THAN TUESDAY IN REGARDS TO
CONVECTION INITIATION AND PLACEMENT.
DID MAINTAIN HIGH CHANCE POPS WITH SVR WORDING THIS AFTERNOON NW
OF THE I-30 CORRIDOR ALONG/JUST N OF THE WARM FRONT...TAPERING
CHANCE POPS DOWN A TAD FARTHER E WHERE FRONTAL CONVERGENCE IS A
BIT WEAKER AND THIS REGION IS FARTHER REMOVED FROM THE TWO LOBES
OF SHORTWAVE ENERGY TO OUR N AND W. AN MCS MAY DEVELOP THIS
EVENING ALONG THE RED RIVER VALLEY AND SHIFT ESE ALONG THE FRONT
TONIGHT /PER THE CONSISTENT GFS SOLUTION AND TO SOME EXTENT THE
ECMWF/...WITH THE THREAT OF DAMAGING WINDS/LARGE HAIL POSSIBLE.
DID CONTINUE MENTION OF SVR OVERNIGHT AREAWIDE GIVEN THE
UNCERTAINTY...ALTHOUGH THIS THREAT SHOULD DIMINISH LATE WITH THE
STABILIZING BNDRY LYR. THE SHORT TERM PROGS ALSO SUGGEST A
SLIGHTLY FASTER MOVEMENT OF THE COLD FRONT AS IT BEGINS TO
BACKDOOR SW INTO SE OK/SW AR OVERNIGHT...BEFORE PULLING UP
STATIONARY OVER N LA/E TX THURSDAY. WEAK ISENTROPIC ASCENT ATOP
THE BNDRY MAY RESULT IN SCT CONVECTION DURING THE DAY...ALTHOUGH
THE LACK OF UPPER LEVEL ENERGY SHOULD KEEP QPF AMOUNTS LIGHT. IN
ADDITION...MESOSCALE BNDRYS FROM CONVECTION THIS AFTERNOON AND
TONIGHT MAY PLAY A ROLE IN CONVECTION INITIATION THURSDAY ACROSS
THE WARM SECTOR S OF THE FRONT. BUT ATTM...CONFIDENCE IS LOW IN
REGARDS TO THE PLACEMENT OF THE SVR THREAT...THUS HAVE REMOVED SVR
MENTION FROM THE FORECAST THURSDAY...ALTHOUGH CAN/T RULE OUT AN
ISOLATED SVR STORM WITHIN THE MODERATELY UNSTABLE AIR MASS.
WILL BE WATCHING THE CLOSED SRN CA UPPER LOW AS IT EJECTS NE
ACROSS THE FOUR CORNERS REGION AND OPENS UP THURSDAY
NIGHT...ENTERING THE SRN PLAINS FRIDAY. THE WILL SET UP A STRONG
SW FLOW ALOFT...WITH A 70-80KT MID LEVEL SPEED MAX EJECTING OVER
THE SRN PLAINS FRIDAY AFTERNOON. THIS WILL RESULT IN AN INCREASING
SSWRLY LOW LEVEL FLOW THURSDAY NIGHT/FRIDAY MORNING...THUS LIFTING
THE STATIONARY FRONT BACK N AS A WARM FRONT ACROSS OK/AR FRIDAY
AND HENCE BROADING THE WARM SECTOR. THE W TX DRYLINE WILL MIX E
INTO ERN OK TO JUST W OF THE I-35 CORRIDOR OF CNTRL TX FRIDAY
EVENING...WITH BROAD DIFFLUENCE ALOFT CONTRIBUTING TO SCT TO
NUMEROUS CONVECTION AREAWIDE ESPECIALLY DURING PEAK HEATING. LOW
LEVEL WINDS DO VEER MORE ACROSS THE REGION WELL E OF THE DRYLINE
FRIDAY...WITH A MORE UNIDIRECTIONAL FLOW NOTED ABOVE 850MB. GIVEN
THE STRONG DEEP LYR SHEAR AND MODERATE MLCAPES EXPECTED TO BE IN
PLACE...A MORE PRONOUNCED SVR THREAT WILL BE POSSIBLE WITH
DAMAGING WINDS/ISOLATED TORNADOES. MID LEVEL DRY AIR SHOULD ADVECT
ENE AHEAD OF THE EJECTING TROUGH FRIDAY EVENING...THUS TAPERING
THE CONVECTION FROM W TO E OVERNIGHT...WITH THE DRYLINE PULLING UP
STATIONARY JUST W OF THE REGION. THIS BNDRY SHOULD MIX E ACROSS
THE REGION SATURDAY AS WRLY WINDS INCREASE BENEATH THE MIDWEST SFC
CYCLONE...RESULTING IN PERHAPS THE WARMEST TEMPS SO FAR THIS
SRPING SEASON AS READING CLIMB WELL INTO THE MID 80S AND POSSIBLY
90 DEGREES OVER PORTIONS OF E TX/N LA.
UPPER RIDGING SHOULD AMPLIFY OVER THE CNTRL CONUS BY SUNDAY BEFORE
THE NEXT CLOSED LOW DIGS SE INTO THE SRN ROCKIES SUNDAY BEFORE
MOVING INTO THE SRN PLAINS MONDAY. THIS COULD RESULT IN ANOTHER
SVR THREAT FOR THE REGION BY THE MONDAY/TUESDAY
TIMEFRAME...ALTHOUGH DISCREPENCIES IN TIMING AMONGST THE FASTER
GFS/SLOWER ECMWF PRECLUDES A HIGHER CONFIDENCE ATTM. HOWEVER...THE
PROGS DO CONVERGE ON A PATTERN CHANGE BY MID AND LATE WEEK...WITH COOLER
AND DRIER CONDITIONS SPILLING S ACROSS THE ERN TWO-THIRDS OF THE
CONUS.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 80 64 77 67 / 40 70 40 30
MLU 80 63 77 64 / 30 70 40 20
DEQ 76 58 67 58 / 50 70 40 40
TXK 77 60 71 62 / 40 70 40 30
ELD 78 60 71 60 / 30 70 40 30
TYR 79 65 81 69 / 40 60 30 40
GGG 80 65 80 69 / 40 60 30 40
LFK 84 68 85 71 / 40 50 30 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
619 AM CDT WED APR 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM CDT WED APR 22 2015
ELONGATED HIGH PRESSURE FROM CANADA TO THE
MISSOURI BASIN DRIFTS EAST TODAY SETTING UP A COOL SOUTHERLY RETURN
FLOW FROM KANSAS. THE RAP MODEL INDICATES A WARM FRONT WILL DEVELOP
ACROSS WRN NEB WHICH MOVES EAST THIS AFTERNOON AND TONIGHT. THE
MODEL SUGGESTS A NARROW MIDLEVEL CLOUD SHIELD WILL DEVELOP NEAR
VALENTINE TONIGHT WHICH IS WELL SUPPORTED BY THE GFS...LESS SO BY
THE OTHER MODELS. THE OBVIOUS CULPRIT IS 700MB FRONTOGENESIS AND THE
DEVELOPING WARM FRONT. THE FORECAST IS FOR PARTLY CLOUDY SKIES TODAY
AND TONIGHT WITH TEMPERATURES RISING INTO THE 50S AND 60S. LOWS
TONIGHT FALL INTO THE 30S TO NEAR FREEZING EAST OF HIGHWAY 83.
MOISTURE WILL RETURN LATE TONIGHT ACROSS SWRN NEB. THE MODEL
SOUNDINGS SUGGESTS A SUNRISE SURPRISE THURSDAY MORNING WITH STRATUS
DEVELOPING WITH THE ONSET OF MIXING AFTER SUNRISE. A SLIGHT DELAY
OF 3 HOURS IN THE MOISTURE RETURN WOULD RESULT IN SUFFICIENT
HEATING AND MIXING TO PRECLUDE CLOUD DEVELOPMENT. MEANWHILE...IF
THE MODELS ARE TOO SLOW THEN CLOUDS COULD FORM BEFORE SUNRISE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 348 AM CDT WED APR 22 2015
LONG WAVE TROUGH WILL BE MOVING ONSHORE THE WEST COAST
THURSDAY...WITH FLOW ALOFT BECOMING SOUTHWEST AHEAD OF THE TROUGH
ACROSS THE CENTRAL PLAINS. ONE DISTURBANCE WILL EJECT NORTHEAST FROM
THE TROUGH THURSDAY NIGHT INTO FRIDAY. MODELS ARE WEAKER WITH THIS
FEATURE COMPARED TO A COUPLE OF DAYS AGO...AND HAVE PUT THE BREAKS
ON THE POPS. WILL LEAVE IN THE CHANCE CATEGORY FOR THE MOST PART.
LIFT IS MARGINAL AND NOT ORGANIZED IN ANY ONE AREA...SO THINKING A
MORE SHOWERY TYPE RAIN WILL OCCUR. ACTUALLY KIND OF HARD TO PIN DOWN
EXACTLY WHERE...BUT THE BETTER CHANCE WOULD LIKELY BE AFTER MIDNIGHT
THURSDAY NIGHT INTO FRIDAY MORNING ON THE NOSE OF A SOUTHERLY LOW
LEVEL JET ACROSS CENTRAL INTO EASTERN NEBRASKA. THEN LATER IN THE
DAY ACROSS THE WESTERN HIGH PLAINS OF NEBRASKA INTO EASTERN
COLORADO...AS CONDITIONS BECOME SOMEWHAT UNSTABLE LEADING TO A
SCATTERING OF THUNDERSTORMS. THESE STORMS WILL BE AIDED BY THE
ACTUAL DISTURBANCE CROSSING THE AREA DURING PEAK HEATING. THESE
STORMS WILL WEAKEN SOMEWHAT AS THEY MOVE EAST...BUT DO EXPECT AT
LEAST SHOWERS TO MOVE ACROSS THE AREA FRIDAY NIGHT. AGAIN...DOESN/T
APPEAR TO BE REAL ORGANIZED...AND CAN/T JUSTIFY LIKELY POPS AT ANY
ONE LOCATION AT THIS TIME.
FOR THE WEEKEND INTO EARLY NEXT WEEK...IT LOOKS RATHER INTERESTING.
THE LONG WAVE TROUGH MOVES INTO THE ROCKIES BY SUNDAY. SATURDAY
LOOKING TO BE A FAIRLY DRY DAY AS RIDGING DEVELOPS ACROSS THE
CENTRAL PLAINS AHEAD OF THE TROUGH. TRIED TO LIMIT POPS TO JUST A
SLIGHT CHANCE FOR THIS REASON SATURDAY. BY SUNDAY NIGHT INTO
MONDAY...THE MODELS DIG THE TROUGH INTO THE FOUR CORNERS WHERE IT
SHOULD CLOSE OFF. VERY GOOD AGREEMENT AMONG THE GFS ENSEMBLE
MEMBERS ON THIS OCCURRING...AND BOTH THE OPERATIONAL GFS AND ECMWF
INDICATE THIS SCENARIO AS WELL. HOWEVER...THE ECMWF CONTINUES TO
DIG THE SYSTEM SOUTH INTO TEXAS LEAVING US WITH LITTLE
PRECIPITATION. THE GFS AND GFS ENSEMBLE MEAN ON THE OTHER HAND ARE
FARTHER NORTH...AND HAVE A CLOSED H700MB LOW CENTER IN SOUTHEAST
COLORADO SUNDAY NIGHT. ALSO THEY HAVE HEAVY RAINFALL SUNDAY NIGHT
INTO MONDAY FROM NORTHWEST KANSAS...NORTH AND WEST ACROSS
NORTHEAST COLORADO...SOUTHWEST NEBRASKA AND THE SOUTHERN NEBRASKA
PANHANDLE. OVERALL THIS STRONG CLOSED SYSTEM IS A NEW DEVELOPMENT
IN THE MODELS/ENSEMBLE TONIGHT...AND WON/T GET CARRIED AWAY WITH
RAIN CHANCES JUST YET. ALSO TONIGHT/S SOLUTIONS ARE A BIT
SLOWER...SO THE HIGHER CHANCES FOR RAIN CURRENTLY IN THE FORECAST
FOR SUNDAY MAY HAVE TO BE EXTENDED INTO SUNDAY NIGHT AND MONDAY.
WILL CONTINUE TO MONITOR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 614 AM CDT WED APR 22 2015
VFR IS EXPECTED ALL AREAS TODAY AND TONIGHT THROUGH 06Z.
THEREAFTER...THE MODELS SUGGEST MOISTURE ACROSS OKLAHOMA WILL
RETURN NORTH UP THE HIGH PLAINS. THUS THERE IS THE POTENTIAL FOR
MVFR/IFR CIGS TO DEVELOP SOUTH OF INTERSTATE 80 09Z-12Z ASSUMING
THE MODEL TIMING IS CORRECT. IF THE MOISTURE RETURN IS SLOW THESE
LOW CIGS COULD FORM 13Z-15Z OR NOT AT ALL IF THE MOISTURE RETURN
IS EVEN SLOWER.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
736 AM EDT WED APR 22 2015
.SYNOPSIS...
A LARGE UPPER LEVEL LOW PRESSURE SYSTEM ACROSS THE GREAT LAKES AND
ONTARIO WILL DRIFT SLOWLY EASTWARD THROUGH THE END OF THE WEEK. THIS
SYSTEM WILL PROVIDE THE NORTH COUNTRY WITH SEASONABLY COOL
CONDITIONS...ALONG WITH CONSIDERABLE CLOUDINESS. EMBEDDED SMALLER
SCALE DISTURBANCES WILL BRING PERIODS OF RAIN SHOWERS...WHICH WILL
BE MOST WIDESPREAD LATE TODAY INTO TONIGHT. SOME SNOW SHOWERS ARE
POSSIBLE ACROSS THE HIGHER TERRAIN...WITH SOME ACCUMULATING SNOW
FOR THE SUMMITS ESPECIALLY THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 724 AM EDT WEDNESDAY...NORTH COUNTRY WILL REMAIN IN DEEP-
LAYER SWLY FLOW TODAY...AS CLOSED UPPER LOW REMAINS QUASI-
STATIONARY NORTH OF THE U.P. OF MICHIGAN. SHORTWAVE TROUGH
ROUNDING THE BASE OF THE 500MB TROUGH WILL SHIFT NEWD FROM PA
ACROSS NY/NEW ENGLAND DURING THE AFTN HRS. THIS WILL ENHANCE
UPWARD MOTION AND EXPAND COVERAGE OF SHOWER ACTIVITY THIS
AFTERNOON AND EVENING. ALL GUIDANCE CONSISTENT IN SHOWING SHOWER
ACTIVITY MOST WIDESPREAD ACROSS CENTRAL/ERN VT...AND HAVE SHOWN
HIGHEST POPS THERE (80-100 PERCENT)...AND GENERALLY 50-80 PERCENT
ACROSS THE CHAMPLAIN VALLEY WWD INTO THE ADIRONDACKS.
BASED ON EARLY AM RADAR TRENDS...IT APPEARS ISOLD/SCT SHOWERS WILL
MOVE ACROSS NRN NY - AND PERHAPS INTO THE CHAMPLAIN VALLEY -
DURING THE MID MORNING HRS. SHOWERS MOVING GENERALLY NE 30-35
MPH EAST OF LAKE ONTARIO AS OF 1120Z. HAVE CARRIED CHANCE POPS
DURING THE MORNING HRS TO COVER THIS SHOWER ACTIVITY AS IT MOVES
NEWD. OVERALL TREND WILL BE FOR ACTIVITY TO BECOME MORE
WIDESPREAD AS THE AFTERNOON PROGRESSES, ESPECIALLY FOR CENTRAL
AND ERN VT. SUNNY SKIES EXPECTED AT TIMES DURING THE MORNING
HRS...BEFORE TRENDING MOSTLY CLOUDY FOR THE AFTERNOON AND EVENING
PERIOD. RAINFALL AMTS GENERALLY A TENTH TO 0.30" FROM THE
ADIRONDACKS EWD...WITH THE HIGHEST TOTALS EXPECTED ACROSS ERN VT.
MEANWHILE...RAINFALL GENERALLY <0.10" ACROSS THE ST. LAWRENCE
VALLEY. HIGH TEMPERATURES TODAY GENERALLY EXPECTED IN THE MID-UPR
50S. SFC WINDS GENERALLY SOUTH 10-15 MPH THIS MORNING...SHIFTING
INTO THE SW AND WEST THIS AFTN WITH TROUGH PASSAGE.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/...
AS OF 306 AM EDT WEDNESDAY...THE SHORT-TERM WILL FEATURE CONTINUED
SEASONABLY COOL AND MOIST CONDITIONS...WITH POTENTIAL FOR
UPSLOPE/OROGRAPHIC SNOWFALL THURSDAY NIGHT INTO FRIDAY...INCLUDING
LIGHT TO MODERATE ACCUMULATIONS FOR THE HIGHER SUMMITS.
LINGERING RAIN SHOWERS ACROSS CENTRAL INTO NERN VT THIS EVENING WILL
GRADUALLY MOVE NEWD OUT OF THE REGION OVERNIGHT. MAY SEE AN
ADDITIONAL 0.10"-0.20" RAINFALL ACROSS CENTRAL/ERN VT BEFORE
ACTIVITY ENDS AROUND MIDNIGHT. SHOULD SEE AT LEAST SOME MODEST RISES
ON AREA RIVERS TONIGHT...AND MINOR FLOODING IS POSSIBLE FOR THE
BARTON RIVER AT COVENTRY BASED ON CURRENT EXPECTATIONS. WHILE SKIES
WILL REMAIN MOSTLY CLOUDY OVERNIGHT...LOW-LEVEL CAA FROM THE WEST
WILL ALLOW TEMPS TO FALL INTO THE LOW-MID 30S FOR OVERNIGHT LOWS.
UPR LOW CENTER PROGRESSES ACROSS NRN NY AND VT ON
THURSDAY...MAINTAINING CLOUDY SKIES, ALONG WITH COOL AND MOIST
CONDITIONS. HIGH TEMPERATURES ON THURSDAY WILL BE WELL BELOW
SEASONABLE NORMS...AND GENERALLY IN THE MID TO UPPER 40S...AND
LOCALLY IN THE LOWER 40S FOR THE NRN ADIRONDACK REGION.
POTENTIAL FOR SHOWERS WILL GRADUALLY INCREASE AS NWLY FLOW DEVELOPS
ACROSS NRN NY THURSDAY AFTN...AND ACROSS VT THURSDAY NIGHT. LOOKS
LIKE AN UPSLOPE FLOW SETUP FOR A TIME THURSDAY NIGHT...AND THERMAL
FIELDS SUPPORT SNOW AT ELEVATIONS ABOVE 1000`...WITH A RAIN/SNOW MIX
POSSIBLE IN VALLEY LOCATIONS LATER THURSDAY NIGHT. LOWS THURSDAY
NIGHT WILL BE NEAR FREEZING MOST LOCATIONS...AND LOCALLY IN THE LOW-
MID 20S ABOVE 2000 FEET ELEVATION.
CYCLONIC FLOW REMAINS IN PLACE THROUGH FRIDAY...WITH ISOLD VALLEY
SHOWERS AND MORE FREQUENT RAIN/SNOW SHOWERS ACROSS THE HIGHER
ELEVATIONS. HIGHS FRIDAY REMAINING COOL...GENERALLY 45-50F.
MAY SEE SOME DECENT SNOWFALL ACCUMULATIONS ACROSS THE HIGHER SUMMITS
OF THE NRN ADIRONDACKS AND CENTRAL/NRN GREEN MTNS...MAINLY THURSDAY
NIGHT AND FRIDAY. CURRENT INDICATIONS SUPPORT AROUND 6" OF NEW SNOW
ALONG THE RIDGE TOPS FROM JAY PEAK TO MT. MANSFIELD...AND SIMILARLY
ACROSS THE HIGH PEAKS OF THE ADIRONDACKS. MAY SEE A WET COATING-1"
SNOWFALL AMTS DOWN TO ABOUT 1000` DURING THURSDAY NIGHT...WITH SNOW
LEVELS RISING DURING THE DAY FRIDAY TO ABOVE 2000`.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 352 AM EDT WEDNESDAY...CONTINUING THE THEME OF PERIODIC
APRIL SHOWERS WITH MOSTLY CLOUDY AND COOL WEATHER FROM CYCLONIC
NORTHWEST UPSLOPE FLOW AROUND A CLOSED UPPER LOW TO OUR NORTH AND
EAST.
MODEL CONSENSUS IS THAT THE LOW WILL INITIALLY BE OVER NORTHERN
MAINE FRIDAY NIGHT AND IT GRADUALLY FILLS AND MOVES SLOWLY EAST
INTO THE CANADIAN MARITIMES BY THE END OF THE PERIOD ON TUESDAY
WHICH WILL LESSEN THE CHANCE OF SHOWERS AS THE DAYS GO ON. STILL A
CHANCE OF SNOW SHOWERS ON THE UPPER PORTIONS OF THE MOUNTAINS BY
DAY WITH FREEZING LEVELS LOWERING OVERNIGHT POSSIBLY REACHING THE
VALLEY LOCATIONS WITH A MIX OF RAIN AND SNOW SHOWERS EARLY MORNING
HOURS.
MODELS CONTINUE TO BE IN DECENT AGREEMENT WITH THE LOCATION OF THE
UPPER LOW THROUGH SUNDAY THEN DIVERGE ON THE PLACEMENT MONDAY AND
TUESDAY. ECWMF A BIT OF AN OUTLIER COMPARED TO THE GFS, GEFS,
NAEFS, UK, AND CANADIAN MODELS WHICH ARE A BIT MORE PROGRESSIVE
VS THE ECMWF WHICH ACTUALLY SHOWS THE LOW RETROGRADING BACK OVER
NEW ENGLAND BY MONDAY NIGHT AND TUESDAY.
DAYTIME MAX TEMPERATURES WILL BE IN THE UPPER 40S TO MID 50S
THROUGHOUT THE LONG TERM WITH LOWS IN THE UPPER 20S TO MID 30S
WITH A SLIGHT UPWARD TREND NEXT WEEK.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...PERIODS OF MVFR DEVELOPING WITH RAIN AND
MIST DEVELOPING, AND EVEN SOME WET SNOW FLAKES MIXED IN AT KSLK.
POSSIBLE IFR AT RUT/MPV FOR A FEW HOURS THIS AFTERNOON BUT
UNCERTAIN SO LEFT IT OUT FOR NOW.
SCATTERED TO BROKEN VFR CLOUDS AND SCATTERED RAIN SHOWERS WILL
PERSIST ACROSS THE REGION THROUGH TODAY. A WAVE OF LOW PRESSURE
WILL BRING A MORE ORGANIZED PERIOD OF LIGHT RAIN IN THE AFTERNOON
AND EVENING AS DEPICTED IN THE LATEST HRRR WHICH HAS A HANDLE ON
SHOWERS NOW ENTERING THE ST. LAWRENCE VALLEY. WINDS
SOUTH/SOUTHWEST LESS THAN 7 KNOTS BECOMING 10 KNOTS WITH GUSTS
15-20 KNOTS DURING THE DAY TODAY.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY...PERSISTENT MOSTLY CLOUDY
CONDITIONS WITH VFR CEILINGS AS UPPER LOW REMAINS IN PLACE.
PERIODS OF LIGHT RAIN SHOWERS WILL RESULT IN INTERMITTENT MVFR
CEILINGS/VISIBILITIES. ON THURSDAY SOME SNOW POSSIBLY WILL MIX IN
WITH RAIN SHOWERS AT MPV/SLK...AND A MIX OF RAIN/SNOW SHOWERS
POSSIBLE AT ALL TAF LOCATIONS DURING THURSDAY NIGHT AND FRIDAY
NIGHT. OTHERWISE MOSTLY RAIN SHOWERS SATURDAY AND SUNDAY.
&&
.HYDROLOGY...
RAINFALL AMOUNTS OF UP TO 0.50" ARE EXPECTED ACROSS CENTRAL/ERN VT
THIS AFTERNOON THROUGH THE FIRST HALF OF TONIGHT. SOME MODEST
RIVER RISES CAN BE EXPECTED LATE TODAY THROUGH TONIGHT. SINCE THE
BARTON RIVER AT COVENTRY HAD AN OBSERVED STAGE OF 7.6` AT 07Z THIS
MORNING...ANTICIPATE THAT ONE FORECAST POINT WILL LIKELY REACH
MINOR FLOOD STAGE (BETWEEN 8-9`) SOMETIME TONIGHT.
ELSEWHERE...RIVER RISES ARE EXPECTED TO BE WITHIN BANKFULL.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...SISSON
AVIATION...SISSON
HYDROLOGY...TEAM BTV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1200 PM EDT WED APR 22 2015
.SYNOPSIS...
A BROAD AREA OF LOW PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER
OVER THE GREAT LAKES THROUGH THE END OF THE WEEK. THIS WILL SUPPORT
BELOW NORMAL TEMPERATURES AND THE CHANCE FOR SOME ON AND OFF RAIN
SHOWERS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED...A FEW ADJUSTMENTS TO THE FORECAST FOR THIS AFTERNOON.
WE ARE RECEIVING SEVERAL REPORTS OF MIXED PRECIPITATION OVER THE
AREA WITH SNOW AND GRAUPEL MIXING WITH THE RAIN. I WILL ADJUST
THE FORECAST TO MENTION THE MIXED PRECIPITATION. HIGH TEMPERATURES
ARE NOT RISING AS FAST AS EARLIER ANTICIPATED. I WILL BUMP THE
HIGH TEMPERATURES BACK A FEW DEGREES INTO THE MID 40S. I WILL ALSO
INCREASE THE CLOUD COVER.
ORIGINAL...UPPER LOW REMAINS IN PLACE ACROSS THE ONTARIO/QUEBEC
REGION. AT THE SURFACE A COLD FRONT CONTINUES TO MOVE THROUGH THE
AREA SPREADING RAIN SHOWERS INVOF THE FRONT. THE FRONT WILL
CONTINUE SOUTHEAST TODAY AND SHOULD BE MOVING EAST OF THE AREA
EARLY THIS MORNING. EXPECTING SHOWERS TO CONTINUE MOST AREAS
THROUGH THE PREDAWN HOURS. AFTER DAWN SHOWERS SHOULD AFFECT MAINLY
SOUTHERN AND EASTERN COUNTIES WITH THE MAIN AREA OF RAIN SOUTHEAST
BY 14-15Z. HRRR DOES SHOW SOME REDEVELOPMENT EASTERN HALF OF THE
AREA LATE MORNING SO WILL HOLD ONTO POPS THERE. THERE ARE SOME
BREAKS IN THE CLOUDS MAINLY ACROSS NWRN OHIO AND SRN LWR MI BUT
THROUGH THE MORNING THIS SHOULD FILL IN WITH SUCH COLD AIR ALOFT
AND ADDITIONAL WRAP AROUND MOISTURE DROPPING ACROSS THE AREA IN
THE AFTERNOON. HIGHS TODAY WILL LIKELY NOT RISE TOO MUCH FROM
MORNING LOWS GIVEN THE COLD ADVECTION ACROSS THE AREA. RISES
LIKELY ON THE ORDER OF 5 DEGREES OR SO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
THE NAM SHOWS NO BIG CHANGES IN STORE FOR NRN OHIO AND NWRN PA
THROUGH THURSDAY AT LEAST WITH PLENTY OF MOISTURE ROTATING ACROSS
THE AREA AROUND THE CLOSED STAGNANT UPPER LOW. THE CIRCULATION
SHIFTS EAST ENOUGH BY FRIDAY TO GET DRIER AIR INTO THE AREA BUT
STILL NO WARM UP WITH 850MB TEMPS BELOW ZERO AND WELL BELOW NORMAL.
SATURDAY MOISTURE WILL RETURN AS LOW PRESSURE MOVES EAST ACROSS
THE LOWER OHIO VALLEY. DEPENDING ON THE PATH WE COULD GET SHOWERS
ASSOCIATED WITH THE LOW INTO THE AREA SO DID PUT IN A CHANCE POP
WESTERN TWO THIRDS.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE FORECAST PERIOD.
BOTH MODELS CONTINUE IN GOOD AGREEMENT WITH HIGH PRESSURE PUSHING
SOUTHEAST ACROSS THE AREA ON SUNDAY. HIGH REMAINS ENTRENCHED OVER
THE FORECAST AREA MONDAY AS LOW PRESSURE TRACKS UP THE EAST COAST.
MODELS DIVERGE ON TUESDAY AS GFS MOVES LOW PRESSURE SYSTEM ACROSS
THE UPPER OHIO VALLEY WHILE ECMWF CONTINUES WITH HIGH PRESSURE OVER
THE AREA. WILL CONTINUE WITH PREVIOUS FORECAST WHICH TRENDED TOWARD
GFS WITH LOW CHANCE POPS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SHOWERS WILL GRADUALLY MOVE EAST OF THE FORECAST AREA BY MID
MORNING AS WEAK SHORT WAVES MOVES EAST. WINDY CONDITIONS WILL
CONTINUE TODAY WITH WEST WINDS 20-30 KTS AS SECONDARY COLD FRONT
PUSHES THROUGH THIS AFTERNOON. POTENTIAL FOR LAKE EFFECT SNOW NW
PA OVERNIGHT...LITTLE OF NO ACCUMULATION.
.OUTLOOK...MVFR CEILINGS AT TIMES THURSDAY MAINLY EXTREME NORTHEAST
OH AND NORTHWEST PA.
&&
.MARINE...
SMALL CRAFT ADVISORY WILL CONTINUE INTO THURSDAY NIGHT. GUSTY WEST
TO SOUTHWEST WINDS WILL CONTINUE INTO THURSDAY NIGHT AS LOW PRESSURE
SLOWLY DRIFTS ACROSS EASTERN CANADA. WINDS WILL BECOME LIGHTER BY
FRIDAY AND FRIDAY NIGHT AS HIGH PRESSURE BUILDS SLOWLY OVER THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THURSDAY FOR LEZ142>146.
&&
$$
SYNOPSIS...TK
NEAR TERM...GARNET
SHORT TERM...TK
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
926 AM EDT WED APR 22 2015
.SYNOPSIS...
A BROAD AREA OF LOW PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER
OVER THE GREAT LAKES THROUGH THE END OF THE WEEK. THIS WILL SUPPORT
BELOW NORMAL TEMPERATURES AND THE CHANCE FOR SOME ON AND OFF RAIN
SHOWERS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED...A FEW ADJUSTMENTS TO THE MORNING FORECAST. I WILL KEEP
A MENTION OF RAIN OVER THE ENTIRE ARE THIS MORNING AND AFTERNOON
AS DIURNAL CLOUDS AND SHOWERS ARE ALREADY FORMING OVER WESTERN
OHIO AND MICHIGAN. WITH THE COLD AIR AND UPPER LEVEL LOW I EXPECT
WIDELY SCATTERED SHOWER ACTIVITY TO CONTINUE THROUGH THE
AFTERNOON. I HAVE ALSO ADJUSTED THE CLOUD COVER GRIDS TO ACCOUNT
FOR THE CU ALREADY FORMING IN CLOUD COVER BREAKS. CURRENT HIGH
TEMPERATURES MAY BE A FEW DEGREES TOO WARM THIS AFTERNOON. 12Z
SOUNDINGS SUGGEST HIGHS IN THE LOWER 40S. I MAY NEED TO LOWER THE
HIGH TEMPERATURES A FEW DEGREES LATER THIS MORNING. I WILL
CONTINUE TO MONITOR.
ORIGINAL...UPPER LOW REMAINS IN PLACE ACROSS THE ONTARIO/QUEBEC
REGION. AT THE SURFACE A COLD FRONT CONTINUES TO MOVE THROUGH THE
AREA SPREADING RAIN SHOWERS INVOF THE FRONT. THE FRONT WILL
CONTINUE SOUTHEAST TODAY AND SHOULD BE MOVING EAST OF THE AREA
EARLY THIS MORNING. EXPECTING SHOWERS TO CONTINUE MOST AREAS
THROUGH THE PREDAWN HOURS. AFTER DAWN SHOWERS SHOULD AFFECT MAINLY
SOUTHERN AND EASTERN COUNTIES WITH THE MAIN AREA OF RAIN SOUTHEAST
BY 14-15Z. HRRR DOES SHOW SOME REDEVELOPMENT EASTERN HALF OF THE
AREA LATE MORNING SO WILL HOLD ONTO POPS THERE. THERE ARE SOME
BREAKS IN THE CLOUDS MAINLY ACROSS NWRN OHIO AND SRN LWR MI BUT
THROUGH THE MORNING THIS SHOULD FILL IN WITH SUCH COLD AIR ALOFT
AND ADDITIONAL WRAP AROUND MOISTURE DROPPING ACROSS THE AREA IN
THE AFTERNOON. HIGHS TODAY WILL LIKELY NOT RISE TOO MUCH FROM
MORNING LOWS GIVEN THE COLD ADVECTION ACROSS THE AREA. RISES
LIKELY ON THE ORDER OF 5 DEGREES OR SO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
THE NAM SHOWS NO BIG CHANGES IN STORE FOR NRN OHIO AND NWRN PA
THROUGH THURSDAY AT LEAST WITH PLENTY OF MOISTURE ROTATING ACROSS
THE AREA AROUND THE CLOSED STAGNANT UPPER LOW. THE CIRCULATION
SHIFTS EAST ENOUGH BY FRIDAY TO GET DRIER AIR INTO THE AREA BUT
STILL NO WARM UP WITH 850MB TEMPS BELOW ZERO AND WELL BELOW NORMAL.
SATURDAY MOISTURE WILL RETURN AS LOW PRESSURE MOVES EAST ACROSS
THE LOWER OHIO VALLEY. DEPENDING ON THE PATH WE COULD GET SHOWERS
ASSOCIATED WITH THE LOW INTO THE AREA SO DID PUT IN A CHANCE POP
WESTERN TWO THIRDS.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE FORECAST PERIOD.
BOTH MODELS CONTINUE IN GOOD AGREEMENT WITH HIGH PRESSURE PUSHING
SOUTHEAST ACROSS THE AREA ON SUNDAY. HIGH REMAINS ENTRENCHED OVER
THE FORECAST AREA MONDAY AS LOW PRESSURE TRACKS UP THE EAST COAST.
MODELS DIVERGE ON TUESDAY AS GFS MOVES LOW PRESSURE SYSTEM ACROSS
THE UPPER OHIO VALLEY WHILE ECMWF CONTINUES WITH HIGH PRESSURE OVER
THE AREA. WILL CONTINUE WITH PREVIOUS FORECAST WHICH TRENDED TOWARD
GFS WITH LOW CHANCE POPS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SHOWERS WILL GRADUALLY MOVE EAST OF THE FORECAST AREA BY MID
MORNING AS WEAK SHORT WAVES MOVES EAST. WINDY CONDITIONS WILL
CONTINUE TODAY WITH WEST WINDS 20-30 KTS AS SECONDARY COLD FRONT
PUSHES THROUGH THIS AFTERNOON. POTENTIAL FOR LAKE EFFECT SNOW NW
PA OVERNIGHT...LITTLE OF NO ACCUMULATION.
.OUTLOOK...MVFR CEILINGS AT TIMES THURSDAY MAINLY EXTREME NORTHEAST
OH AND NORTHWEST PA.
&&
.MARINE...
SMALL CRAFT ADVISORY WILL CONTINUE INTO THURSDAY NIGHT. GUSTY WEST
TO SOUTHWEST WINDS WILL CONTINUE INTO THURSDAY NIGHT AS LOW PRESSURE
SLOWLY DRIFTS ACROSS EASTERN CANADA. WINDS WILL BECOME LIGHTER BY
FRIDAY AND FRIDAY NIGHT AS HIGH PRESSURE BUILDS SLOWLY OVER THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THURSDAY FOR LEZ142>146.
&&
$$
SYNOPSIS...TK
NEAR TERM...GARNET
SHORT TERM...TK
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
711 AM EDT WED APR 22 2015
.SYNOPSIS...
A BROAD AREA OF LOW PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER
OVER THE GREAT LAKES THROUGH THE END OF THE WEEK. THIS WILL SUPPORT
BELOW NORMAL TEMPERATURES AND THE CHANCE FOR SOME ON AND OFF RAIN
SHOWERS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED...UPDATED SKY AND POP GRIDS BASED ON CURRENT SATELLITE AND
RADAR. RADAR LOOPS SHOW TREND REMAINS IN PLACE OF PRECIP MAINLY IN
THE SOUTH AND EASTERN COUNTIES MOVING SOUTHEAST OUT OF THE AREA
THROUGH THE FIRST HALF OF THE MORNING. SATELLITE ALSO SHOWS
CLEARING MOVING IN FROM THE WEST. THIS WILL BE A BRIEF DRY SLOT
THAT SHOULD FILL IN THROUGH LATE MORNING AND EARLY AFTERNOON AS IT
TRAVERSES EAST/SOUTHEAST.
ORIGINAL...UPPER LOW REMAINS IN PLACE ACROSS THE ONTARIO/QUEBEC
REGION. AT THE SURFACE A COLD FRONT CONTINUES TO MOVE THROUGH THE
AREA SPREADING RAIN SHOWERS INVOF THE FRONT. THE FRONT WILL
CONTINUE SOUTHEAST TODAY AND SHOULD BE MOVING EAST OF THE AREA
EARLY THIS MORNING. EXPECTING SHOWERS TO CONTINUE MOST AREAS
THROUGH THE PREDAWN HOURS. AFTER DAWN SHOWERS SHOULD AFFECT MAINLY
SOUTHERN AND EASTERN COUNTIES WITH THE MAIN AREA OF RAIN SOUTHEAST
BY 14-15Z. HRRR DOES SHOW SOME REDEVELOPMENT EASTERN HALF OF THE
AREA LATE MORNING SO WILL HOLD ONTO POPS THERE. THERE ARE SOME
BREAKS IN THE CLOUDS MAINLY ACROSS NWRN OHIO AND SRN LWR MI BUT
THROUGH THE MORNING THIS SHOULD FILL IN WITH SUCH COLD AIR ALOFT
AND ADDITIONAL WRAP AROUND MOISTURE DROPPING ACROSS THE AREA IN
THE AFTERNOON. HIGHS TODAY WILL LIKELY NOT RISE TOO MUCH FROM
MORNING LOWS GIVEN THE COLD ADVECTION ACROSS THE AREA. RISES
LIKELY ON THE ORDER OF 5 DEGREES OR SO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
THE NAM SHOWS NO BIG CHANGES IN STORE FOR NRN OHIO AND NWRN PA
THROUGH THURSDAY AT LEAST WITH PLENTY OF MOISTURE ROTATING ACROSS
THE AREA AROUND THE CLOSED STAGNANT UPPER LOW. THE CIRCULATION
SHIFTS EAST ENOUGH BY FRIDAY TO GET DRIER AIR INTO THE AREA BUT
STILL NO WARM UP WITH 850MB TEMPS BELOW ZERO AND WELL BELOW NORMAL.
SATURDAY MOISTURE WILL RETURN AS LOW PRESSURE MOVES EAST ACROSS
THE LOWER OHIO VALLEY. DEPENDING ON THE PATH WE COULD GET SHOWERS
ASSOCIATED WITH THE LOW INTO THE AREA SO DID PUT IN A CHANCE POP
WESTERN TWO THIRDS.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE FORECAST PERIOD.
BOTH MODELS CONTINUE IN GOOD AGREEMENT WITH HIGH PRESSURE PUSHING
SOUTHEAST ACROSS THE AREA ON SUNDAY. HIGH REMAINS ENTRENCHED OVER
THE FORECAST AREA MONDAY AS LOW PRESSURE TRACKS UP THE EAST COAST.
MODELS DIVERGE ON TUESDAY AS GFS MOVES LOW PRESSURE SYSTEM ACROSS
THE UPPER OHIO VALLEY WHILE ECMWF CONTINUES WITH HIGH PRESSURE OVER
THE AREA. WILL CONTINUE WITH PREVIOUS FORECAST WHICH TRENDED TOWARD
GFS WITH LOW CHANCE POPS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SHOWERS WILL GRADUALLY MOVE EAST OF THE FORECAST AREA BY MID
MORNING AS WEAK SHORT WAVES MOVES EAST. WINDY CONDITIONS WILL
CONTINUE TODAY WITH WEST WINDS 20-30 KTS AS SECONDARY COLD FRONT
PUSHES THROUGH THIS AFTERNOON. POTENTIAL FOR LAKE EFFECT SNOW NW
PA OVERNIGHT...LITTLE OF NO ACCUMULATION.
.OUTLOOK...MVFR CEILINGS AT TIMES THURSDAY MAINLY EXTREME NORTHEAST
OH AND NORTHWEST PA.
&&
.MARINE...
SMALL CRAFT ADVISORY WILL CONTINUE INTO THURSDAY NIGHT. GUSTY WEST
TO SOUTHWEST WINDS WILL CONTINUE INTO THURSDAY NIGHT AS LOW PRESSURE
SLOWLY DRIFTS ACROSS EASTERN CANADA. WINDS WILL BECOME LIGHTER BY
FRIDAY AND FRIDAY NIGHT AS HIGH PRESSURE BUILDS SLOWLY OVER THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THURSDAY FOR LEZ142>146.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
636 AM EDT WED APR 22 2015
.SYNOPSIS...
A BROAD AREA OF LOW PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER
OVER THE GREAT LAKES THROUGH THE END OF THE WEEK. THIS WILL SUPPORT
BELOW NORMAL TEMPERATURES AND THE CHANCE FOR SOME ON AND OFF RAIN
SHOWERS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED...UPDATED SKY AND POP GRIDS BASED ON CURRENT SATELLITE AND
RADAR. RADAR LOOPS SHOW TREND REMAINS IN PLACE OF PRECIP MAINLY IN
THE SOUTH AND EASTERN COUNTIES MOVING SOUTHEAST OUT OF THE AREA
THROUGH THE FIRST HALF OF THE MORNING. SATELLITE ALSO SHOWS
CLEARING MOVING IN FROM THE WEST. THIS WILL BE A BRIEF DRY SLOT
THAT SHOULD FILL IN THROUGH LATE MORNING AND EARLY AFTERNOON AS IT
TRAVERSES EAST/SOUTHEAST.
ORIGINAL...UPPER LOW REMAINS IN PLACE ACROSS THE ONTARIO/QUEBEC
REGION. AT THE SURFACE A COLD FRONT CONTINUES TO MOVE THROUGH THE
AREA SPREADING RAIN SHOWERS INVOF THE FRONT. THE FRONT WILL
CONTINUE SOUTHEAST TODAY AND SHOULD BE MOVING EAST OF THE AREA
EARLY THIS MORNING. EXPECTING SHOWERS TO CONTINUE MOST AREAS
THROUGH THE PREDAWN HOURS. AFTER DAWN SHOWERS SHOULD AFFECT MAINLY
SOUTHERN AND EASTERN COUNTIES WITH THE MAIN AREA OF RAIN SOUTHEAST
BY 14-15Z. HRRR DOES SHOW SOME REDEVELOPMENT EASTERN HALF OF THE
AREA LATE MORNING SO WILL HOLD ONTO POPS THERE. THERE ARE SOME
BREAKS IN THE CLOUDS MAINLY ACROSS NWRN OHIO AND SRN LWR MI BUT
THROUGH THE MORNING THIS SHOULD FILL IN WITH SUCH COLD AIR ALOFT
AND ADDITIONAL WRAP AROUND MOISTURE DROPPING ACROSS THE AREA IN
THE AFTERNOON. HIGHS TODAY WILL LIKELY NOT RISE TOO MUCH FROM
MORNING LOWS GIVEN THE COLD ADVECTION ACROSS THE AREA. RISES
LIKELY ON THE ORDER OF 5 DEGREES OR SO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
THE NAM SHOWS NO BIG CHANGES IN STORE FOR NRN OHIO AND NWRN PA
THROUGH THURSDAY AT LEAST WITH PLENTY OF MOISTURE ROTATING ACROSS
THE AREA AROUND THE CLOSED STAGNANT UPPER LOW. THE CIRCULATION
SHIFTS EAST ENOUGH BY FRIDAY TO GET DRIER AIR INTO THE AREA BUT
STILL NO WARM UP WITH 850MB TEMPS BELOW ZERO AND WELL BELOW NORMAL.
SATURDAY MOISTURE WILL RETURN AS LOW PRESSURE MOVES EAST ACROSS
THE LOWER OHIO VALLEY. DEPENDING ON THE PATH WE COULD GET SHOWERS
ASSOCIATED WITH THE LOW INTO THE AREA SO DID PUT IN A CHANCE POP
WESTERN TWO THIRDS.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE FORECAST PERIOD.
BOTH MODELS CONTINUE IN GOOD AGREEMENT WITH HIGH PRESSURE PUSHING
SOUTHEAST ACROSS THE AREA ON SUNDAY. HIGH REMAINS ENTRENCHED OVER
THE FORECAST AREA MONDAY AS LOW PRESSURE TRACKS UP THE EAST COAST.
MODELS DIVERGE ON TUESDAY AS GFS MOVES LOW PRESSURE SYSTEM ACROSS
THE UPPER OHIO VALLEY WHILE ECMWF CONTINUES WITH HIGH PRESSURE OVER
THE AREA. WILL CONTINUE WITH PREVIOUS FORECAST WHICH TRENDED TOWARD
GFS WITH LOW CHANCE POPS.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
SCATTERED SHOWERS WILL CONTINUE OVERNIGHT WITH A WEAK SHORT WAVE
WILL MOVE ACROSS THE OHIO VALLEY. MAY GET SOME MVFR CONDITIONS IN
THE HEAVIER SHOWERS. WINDY CONDITIONS WILL CONTINUE TODAY...LUCKILY
IT WILL NOT BE AS WINDY AS TUESDAY...MORE LIKE 20-30 KNOT GUSTS
FROM THE WEST.
.OUTLOOK...MVFR CEILINGS AT TIMES THURSDAY MAINLY EXTREME NORTHEAST
OH AND NORTHWEST PA.
&&
.MARINE...
SMALL CRAFT ADVISORY WILL CONTINUE INTO THURSDAY NIGHT. GUSTY WEST
TO SOUTHWEST WINDS WILL CONTINUE INTO THURSDAY NIGHT AS LOW PRESSURE
SLOWLY DRIFTS ACROSS EASTERN CANADA. WINDS WILL BECOME LIGHTER BY
FRIDAY AND FRIDAY NIGHT AS HIGH PRESSURE BUILDS SLOWLY OVER THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THURSDAY FOR LEZ142>146.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1012 AM CDT WED APR 22 2015
.UPDATE...
BUMPED TEMPERATURES UP SLIGHTLY BASED ON CLOUD COVER AND
TEMPERATURE TRENDS. HIGHS SHOULD INTO THE 70S ACROSS MOST OF THE
AREA...PERHAPS TO NEAR 80 IN THE WARMEST LOCATIONS IN NORTH
MISSISSIPPI. SOME SHOWERS AND THUNDERSTORMS CAN BE SEEN ON RADAR
IN EAST OKLAHOMA AND WEST ARKANSAS. THEY ARE EXPECTED TO MOVE
TOWARD THE MIDSOUTH...BUT WEAKEN AS THEY APPROACH. LOWERED POPS
BEFORE NOON. AFTER NOON...AS TEMPERATURES WARM AND SHOWERS
APPROACH FROM THE WEST ANY LOCATION ACROSS THE MIDSOUTH COULD SEE
A SHOWER OR PERHAPS AN ISOLATED THUNDERSTORM.
&&
.PREV DISCUSSION... /ISSUED 637 AM CDT WED APR 22 2015/
DISCUSSION...09Z SURFACE ANALYSIS PLACES A COLD FRONT FROM
SOUTHEAST MISSOURI BACK THROUGH NORTHWEST ARKANSAS AND NORTHEAST
OKLAHOMA. WSR-88D RADAR TRENDS SHOW A WEAKENING LINE OF SHOWERS
BEGINNING TO ENTER PORTIONS OF NORTHEAST ARKANSAS AND THE MISSOURI
BOOTHEEL. AS OF 4 AM CDT...TEMPERATURES ACROSS THE MID SOUTH ARE
PREDOMINANTLY IN THE LOWER TO MIDDLE 50S AT MOST LOCATIONS. STRONG
TO SEVERE THUNDERSTORM POTENTIAL IN THE SHORT TERM IS THE MAIN
CONCERN IN THIS MORNING/S FORECAST ISSUANCE.
SHORT TERM...(TODAY THROUGH FRIDAY)...A COLD FRONT WILL DROP INTO
THE MID SOUTH TODAY. LATEST SHORT TERM MODELS/MODEL SOUNDINGS
INCLUDING THE HRRR SUGGEST AN AREA OF SHOWERS WILL WEAKEN AND
DISSIPATE AS IT MOVES INTO THE MID SOUTH THIS MORNING. HAVE
INCLUDED LOW END CHANCE POPS ACROSS PORTIONS OF NORTHEAST ARKANSAS
THIS MORNING AND ISOLATED POPS ACROSS THE REMAINDER OF THE
FORECAST AREA NORTH OF I-40. SOME SURFACE BASED INSTABILITY WILL
BE PRESENT MAINLY SOUTH OF I-40 AND HAVE INCLUDED ISOLATED SHOWERS
AND THUNDERSTORMS ACROSS THE MID SOUTH THIS AFTERNOON.
WRF/GFS/ECMWF MODELS INDICATE A MESOSCALE CONVECTIVE SYSTEM /MCS/
MAY DEVELOP OVER THE RED RIVER VALLEY THIS AFTERNOON AND MOVE EAST
SOUTHEAST INTO THE LOWER MISSISSIPPI VALLEY TONIGHT. AT THIS
TIME...THINK A BULK OF THIS ACTIVITY WILL REMAIN MOSTLY TO THE
SOUTH OF THE FORECAST AREA TONIGHT WITH THE BEST SHOWER AND
THUNDERSTORM CHANCES MAINLY ACROSS THE SOUTHERN TIER OF COUNTIES
ACROSS NORTHWEST MISSISSIPPI AND CHANCE POPS ACROSS THE REMAINDER
OF NORTH MISSISSIPPI TONIGHT INTO THURSDAY MORNING.
SHOWER AND THUNDERSTORM CHANCES WILL DECREASE ACROSS MOST OF THE
AREA THURSDAY AFTERNOON AS SHORTWAVE RIDGING BUILDS IN ACROSS THE
MID SOUTH INTO THURSDAY EVENING. THE COLD FRONT TO THE SOUTH OF
THE AREA IS EXPECTED TO BEGIN MOVING BACK NORTH AS WARM FRONT
LATE THURSDAY NIGHT INTO FRIDAY WITH SHOWERS AND THUNDERSTORMS
RETURNING ONCE AGAIN.
INCREASING SURFACE BASED INSTABILITY TO PERHAPS AROUND 1500
J/KG...0-6 KM BULK SHEAR VALUES AVERAGING AROUND 50-55 KTS...0-1
KM STORM RELATIVE HELICITY VALUES BETWEEN 200-300 M2/S2...FAVORABLE
WINDS ALOFT AND BACKED SURFACE WINDS SUGGEST POSSIBLE MCS
DEVELOPMENT ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI
VALLEY AND A SUBSEQUENT POTENTIAL FOR SEVERE THUNDERSTORMS FRIDAY
INTO FRIDAY NIGHT. LARGE HAIL...DAMAGING WINDS...AND PERHAPS A
POTENTIAL FOR TORNADOES ARE THE POTENTIAL SEVERE THUNDERSTORM
THREATS. AS OF THIS MORNING...THE SPC DAY THREE OUTLOOK CURRENTLY
COVERS PORTIONS OF EAST/NORTHEAST ARKANSAS...NORTHWEST MISSISSIPPI
AND FAR SOUTHWEST TENNESSEE AHEAD OF AN APPROACHING COLD FRONT. A
WARM...VERY UNSTABLE AIRMASS WILL BE IN PLACE SATURDAY AS
TEMPERATURES RISE INTO THE UPPER 70S TO LOWER 80S. AT THIS
TIME...IT APPEARS THAT SEVERE THUNDERSTORMS ARE AGAIN POSSIBLE
ON SATURDAY. IN ADDITION TO THE SEVERE THUNDERSTORM THREAT
FRIDAY AND SATURDAY...HIGH PRECIPITABLE WATER VALUES SUGGEST A
POTENTIAL FOR HEAVY RAINFALL DURING THIS TIME FRAME. WILL INCLUDE
MENTION OF THREATS IN THE HAZARDOUS WEATHER OUTLOOK AND LATER
SHIFTS WILL ADJUST POSSIBLE THREATS IN SUBSEQUENT MODEL RUNS. STAY
TUNED...
LONG TERM...(SATURDAY NIGHT THROUGH TUESDAY)...00Z GFS/ECMWF
LONG RANGE MODELS ARE IN DECENT AGREEMENT ON SATURDAY BUT DIVERGE
THEREAFTER AS EVIDENT IN EACH LONG RANGE MODEL/S RUN TO RUN
CONTINUITY AS THEY STRUGGLE TO RESOLVE A SPLIT FLOW REGIME ACROSS
THE CONTINENTAL UNITED STATES. THUS...HAVE LEANED POPS TOWARDS
LOWER CONFIDENCE THROUGH MUCH OF THE FORECAST BEYOND SATURDAY.
CJC
&&
.AVIATION...12Z TAFS
VFR WILL PREVAIL THROUGH THE DAY...AS A REINFORCING PUSH OF
RELATIVELY DRY MIDCONTINENTAL AIR FLOWS INTO THE REGION BEHIND A
WEAK COLD FRONT THIS MORNING. SMALL PATCH OF POST FRONTAL MVFR
CIGS OVER KY SHOULD PASS TO THE EAST OF MKL...BUT WILL NEED TO
MONITORED IN THE SHORT TERM.
EXTENSIVE MIDLEVEL MOISTURE WILL SPREAD OVER THE ELEVATED FRONTAL
SURFACE THIS EVENING. NAM BUFR SOUNDINGS DRY LAYER AT MEM DECREASING
IN DEPTH FROM FL100 AROUND THE TIME OF THE CARGO ARRIVAL PUSH...TO
FL060 NEAR THE END OF THE VALID TAF PERIOD. PERSISTENT ELEVATED
RAINFALL MAY BE SUFFICIENT DROP CIGS INTO THE HIGH MVFR CAT AT TUP
DURING THE LATE OVERNIGHT.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
637 AM CDT WED APR 22 2015
.UPDATE...
UPDATED FOR 12Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 515 AM CDT WED APR 22 2015/
DISCUSSION...09Z SURFACE ANALYSIS PLACES A COLD FRONT FROM
SOUTHEAST MISSOURI BACK THROUGH NORTHWEST ARKANSAS AND NORTHEAST
OKLAHOMA. WSR-88D RADAR TRENDS SHOW A WEAKENING LINE OF SHOWERS
BEGINNING TO ENTER PORTIONS OF NORTHEAST ARKANSAS AND THE MISSOURI
BOOTHEEL. AS OF 4 AM CDT...TEMPERATURES ACROSS THE MID SOUTH ARE
PREDOMINANTLY IN THE LOWER TO MIDDLE 50S AT MOST LOCATIONS. STRONG
TO SEVERE THUNDERSTORM POTENTIAL IN THE SHORT TERM IS THE MAIN
CONCERN IN THIS MORNING/S FORECAST ISSUANCE.
SHORT TERM...(TODAY THROUGH FRIDAY)...A COLD FRONT WILL DROP INTO
THE MID SOUTH TODAY. LATEST SHORT TERM MODELS/MODEL SOUNDINGS
INCLUDING THE HRRR SUGGEST AN AREA OF SHOWERS WILL WEAKEN AND
DISSIPATE AS IT MOVES INTO THE MID SOUTH THIS MORNING. HAVE
INCLUDED LOW END CHANCE POPS ACROSS PORTIONS OF NORTHEAST ARKANSAS
THIS MORNING AND ISOLATED POPS ACROSS THE REMAINDER OF THE
FORECAST AREA NORTH OF I-40. SOME SURFACE BASED INSTABILITY WILL
BE PRESENT MAINLY SOUTH OF I-40 AND HAVE INCLUDED ISOLATED SHOWERS
AND THUNDERSTORMS ACROSS THE MID SOUTH THIS AFTERNOON.
WRF/GFS/ECMWF MODELS INDICATE A MESOSCALE CONVECTIVE SYSTEM /MCS/
MAY DEVELOP OVER THE RED RIVER VALLEY THIS AFTERNOON AND MOVE EAST
SOUTHEAST INTO THE LOWER MISSISSIPPI VALLEY TONIGHT. AT THIS
TIME...THINK A BULK OF THIS ACTIVITY WILL REMAIN MOSTLY TO THE
SOUTH OF THE FORECAST AREA TONIGHT WITH THE BEST SHOWER AND
THUNDERSTORM CHANCES MAINLY ACROSS THE SOUTHERN TIER OF COUNTIES
ACROSS NORTHWEST MISSISSIPPI AND CHANCE POPS ACROSS THE REMAINDER
OF NORTH MISSISSIPPI TONIGHT INTO THURSDAY MORNING.
SHOWER AND THUNDERSTORM CHANCES WILL DECREASE ACROSS MOST OF THE
AREA THURSDAY AFTERNOON AS SHORTWAVE RIDGING BUILDS IN ACROSS THE
MID SOUTH INTO THURSDAY EVENING. THE COLD FRONT TO THE SOUTH OF
THE AREA IS EXPECTED TO BEGIN MOVING BACK NORTH AS WARM FRONT
LATE THURSDAY NIGHT INTO FRIDAY WITH SHOWERS AND THUNDERSTORMS
RETURNING ONCE AGAIN.
INCREASING SURFACE BASED INSTABILITY TO PERHAPS AROUND 1500
J/KG...0-6 KM BULK SHEAR VALUES AVERAGING AROUND 50-55 KTS...0-1
KM STORM RELATIVE HELICITY VALUES BETWEEN 200-300 M2/S2...FAVORABLE
WINDS ALOFT AND BACKED SURFACE WINDS SUGGEST POSSIBLE MCS
DEVELOPMENT ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI
VALLEY AND A SUBSEQUENT POTENTIAL FOR SEVERE THUNDERSTORMS FRIDAY
INTO FRIDAY NIGHT. LARGE HAIL...DAMAGING WINDS...AND PERHAPS A
POTENTIAL FOR TORNADOES ARE THE POTENTIAL SEVERE THUNDERSTORM
THREATS. AS OF THIS MORNING...THE SPC DAY THREE OUTLOOK CURRENTLY
COVERS PORTIONS OF EAST/NORTHEAST ARKANSAS...NORTHWEST MISSISSIPPI
AND FAR SOUTHWEST TENNESSEE AHEAD OF AN APPROACHING COLD FRONT. A
WARM...VERY UNSTABLE AIRMASS WILL BE IN PLACE SATURDAY AS
TEMPERATURES RISE INTO THE UPPER 70S TO LOWER 80S. AT THIS
TIME...IT APPEARS THAT SEVERE THUNDERSTORMS ARE AGAIN POSSIBLE
ON SATURDAY. IN ADDITION TO THE SEVERE THUNDERSTORM THREAT
FRIDAY AND SATURDAY...HIGH PRECIPITABLE WATER VALUES SUGGEST A
POTENTIAL FOR HEAVY RAINFALL DURING THIS TIME FRAME. WILL INCLUDE
MENTION OF THREATS IN THE HAZARDOUS WEATHER OUTLOOK AND LATER
SHIFTS WILL ADJUST POSSIBLE THREATS IN SUBSEQUENT MODEL RUNS. STAY
TUNED...
LONG TERM...(SATURDAY NIGHT THROUGH TUESDAY)...00Z GFS/ECMWF
LONG RANGE MODELS ARE IN DECENT AGREEMENT ON SATURDAY BUT DIVERGE
THEREAFTER AS EVIDENT IN EACH LONG RANGE MODEL/S RUN TO RUN
CONTINUITY AS THEY STRUGGLE TO RESOLVE A SPLIT FLOW REGIME ACROSS
THE CONTINENTAL UNITED STATES. THUS...HAVE LEANED POPS TOWARDS
LOWER CONFIDENCE THROUGH MUCH OF THE FORECAST BEYOND SATURDAY.
CJC
&&
.AVIATION...
12Z TAFS
VFR WILL PREVAIL THROUGH THE DAY...AS A REINFORCING PUSH OF
RELATIVELY DRY MIDCONTINENTAL AIR FLOWS INTO THE REGION BEHIND A
WEAK COLD FRONT THIS MORNING. SMALL PATCH OF POST FRONTAL MVFR
CIGS OVER KY SHOULD PASS TO THE EAST OF MKL...BUT WILL NEED TO
MONITORED IN THE SHORT TERM.
EXTENSIVE MIDLEVEL MOISTURE WILL SPREAD OVER THE ELEVATED FRONTAL
SURFACE THIS EVENING. NAM BUFR SOUNDINGS DRY LAYER AT MEM DECREASING
IN DEPTH FROM FL100 AROUND THE TIME OF THE CARGO ARRIVAL PUSH...TO
FL060 NEAR THE END OF THE VALID TAF PERIOD. PERSISTENT ELEVATED
RAINFALL MAY BE SUFFICIENT DROP CIGS INTO THE HIGH MVFR CAT AT TUP
DURING THE LATE OVERNIGHT.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
515 AM CDT WED APR 22 2015
.DISCUSSION...09Z SURFACE ANALYSIS PLACES A COLD FRONT FROM
SOUTHEAST MISSOURI BACK THROUGH NORTHWEST ARKANSAS AND NORTHEAST
OKLAHOMA. WSR-88D RADAR TRENDS SHOW A WEAKENING LINE OF SHOWERS
BEGINNING TO ENTER PORTIONS OF NORTHEAST ARKANSAS AND THE MISSOURI
BOOTHEEL. AS OF 4 AM CDT...TEMPERATURES ACROSS THE MID SOUTH ARE
PREDOMINANTLY IN THE LOWER TO MIDDLE 50S AT MOST LOCATIONS. STRONG
TO SEVERE THUNDERSTORM POTENTIAL IN THE SHORT TERM IS THE MAIN
CONCERN IN THIS MORNING/S FORECAST ISSUANCE.
.SHORT TERM...(TODAY THROUGH FRIDAY)...A COLD FRONT WILL DROP INTO
THE MID SOUTH TODAY. LATEST SHORT TERM MODELS/MODEL SOUNDINGS
INCLUDING THE HRRR SUGGEST AN AREA OF SHOWERS WILL WEAKEN AND
DISSIPATE AS IT MOVES INTO THE MID SOUTH THIS MORNING. HAVE
INCLUDED LOW END CHANCE POPS ACROSS PORTIONS OF NORTHEAST ARKANSAS
THIS MORNING AND ISOLATED POPS ACROSS THE REMAINDER OF THE
FORECAST AREA NORTH OF I-40. SOME SURFACE BASED INSTABILITY WILL
BE PRESENT MAINLY SOUTH OF I-40 AND HAVE INCLUDED ISOLATED SHOWERS
AND THUNDERSTORMS ACROSS THE MID SOUTH THIS AFTERNOON.
WRF/GFS/ECMWF MODELS INDICATE A MESOSCALE CONVECTIVE SYSTEM /MCS/
MAY DEVELOP OVER THE RED RIVER VALLEY THIS AFTERNOON AND MOVE EAST
SOUTHEAST INTO THE LOWER MISSISSIPPI VALLEY TONIGHT. AT THIS
TIME...THINK A BULK OF THIS ACTIVITY WILL REMAIN MOSTLY TO THE
SOUTH OF THE FORECAST AREA TONIGHT WITH THE BEST SHOWER AND
THUNDERSTORM CHANCES MAINLY ACROSS THE SOUTHERN TIER OF COUNTIES
ACROSS NORTHWEST MISSISSIPPI AND CHANCE POPS ACROSS THE REMAINDER
OF NORTH MISSISSIPPI TONIGHT INTO THURSDAY MORNING.
SHOWER AND THUNDERSTORM CHANCES WILL DECREASE ACROSS MOST OF THE
AREA THURSDAY AFTERNOON AS SHORTWAVE RIDGING BUILDS IN ACROSS THE
MID SOUTH INTO THURSDAY EVENING. THE COLD FRONT TO THE SOUTH OF
THE AREA IS EXPECTED TO BEGIN MOVING BACK NORTH AS WARM FRONT
LATE THURSDAY NIGHT INTO FRIDAY WITH SHOWERS AND THUNDERSTORMS
RETURNING ONCE AGAIN.
INCREASING SURFACE BASED INSTABILITY TO PERHAPS AROUND 1500
J/KG...0-6 KM BULK SHEAR VALUES AVERAGING AROUND 50-55 KTS...0-1
KM STORM RELATIVE HELICITY VALUES BETWEEN 200-300 M2/S2...FAVORABLE
WINDS ALOFT AND BACKED SURFACE WINDS SUGGEST POSSIBLE MCS
DEVELOPMENT ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI
VALLEY AND A SUBSEQUENT POTENTIAL FOR SEVERE THUNDERSTORMS FRIDAY
INTO FRIDAY NIGHT. LARGE HAIL...DAMAGING WINDS...AND PERHAPS A
POTENTIAL FOR TORNADOES ARE THE POTENTIAL SEVERE THUNDERSTORM
THREATS. AS OF THIS MORNING...THE SPC DAY THREE OUTLOOK CURRENTLY
COVERS PORTIONS OF EAST/NORTHEAST ARKANSAS...NORTHWEST MISSISSIPPI
AND FAR SOUTHWEST TENNESSEE AHEAD OF AN APPROACHING COLD FRONT. A
WARM...VERY UNSTABLE AIRMASS WILL BE IN PLACE SATURDAY AS
TEMPERATURES RISE INTO THE UPPER 70S TO LOWER 80S. AT THIS
TIME...IT APPEARS THAT SEVERE THUNDERSTORMS ARE AGAIN POSSIBLE
ON SATURDAY. IN ADDITION TO THE SEVERE THUNDERSTORM THREAT
FRIDAY AND SATURDAY...HIGH PRECIPITABLE WATER VALUES SUGGEST A
POTENTIAL FOR HEAVY RAINFALL DURING THIS TIME FRAME. WILL INCLUDE
MENTION OF THREATS IN THE HAZARDOUS WEATHER OUTLOOK AND LATER
SHIFTS WILL ADJUST POSSIBLE THREATS IN SUBSEQUENT MODEL RUNS. STAY
TUNED...
.LONG TERM...(SATURDAY NIGHT THROUGH TUESDAY)...00Z GFS/ECMWF
LONG RANGE MODELS ARE IN DECENT AGREEMENT ON SATURDAY BUT DIVERGE
THEREAFTER AS EVIDENT IN EACH LONG RANGE MODEL/S RUN TO RUN
CONTINUITY AS THEY STRUGGLE TO RESOLVE A SPLIT FLOW REGIME ACROSS
THE CONTINENTAL UNITED STATES. THUS...HAVE LEANED POPS TOWARDS
LOWER CONFIDENCE THROUGH MUCH OF THE FORECAST BEYOND SATURDAY.
CJC
&&
.AVIATION...
06Z TAFS
VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. AREA OF
SHRAS AHEAD OF AN APPROACHING COLD FRONT MOVING ACROSS NORTHERN
SECTIONS OF THE MIDSOUTH ATTM. THE ASSOCIATED WEAK GUST FRONT
WILL BRIEFLY TURN WINDS NWLY AT MKL WITH PERHAPS A SHRA ON
STATION. REMAINDER OF NIGHT WILL FEATURE SSW WINDS AROUND 10 KTS
AT KMEM...KJBR AND KMKL...LIGHTER AT KTUP. COLD FRONT WILL MOVE
THROUGH ON MONDAY. A FEW SHRA ARE POSSIBLE AT KJBR AND KMKL BUT
NOT WORTHY OF VCSH YET. OTRW WINDS WILL SHIFT AROUND TO THE NW/N
AT 10 KTS. SHRAS AND SOME LOWER CLOUDS WILL BEGIN APPROACHING FROM
THE WEST TOWARD THE END OF THE PERIOD AND ADDED A VCSH AND A
BKN050 DECK AT KJBR/KMEM AROUND 23/05Z.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
952 AM PDT Wed Apr 22 2015
.Synopsis...
The threat of afternoon and evening showers and thunderstorms,
mainly over the mountains, will continue through the week.
&&
.Discussion...
Low clouds over the Delta, srn Sac valley and foothills slow to
lift this morning but should erode by noon. Showers and
thunderstorms will again develop over the Sierra during the
afternoon. Activity should be stronger this afternoon versus the
previous few days...but not expecting much over Cascades/Shasta
county. Short term HRRR model brings activity into the valleys
this evening...but this is not supported by other operational
models. Feel the chances for valley convection is low...especially
with stabilizing delta breeze this evening.
.Previous Discussion... Mostly cloudy skies cover most of the
interior of NorCal early this morning with plenty of mid and
upper-level moisture over the area. Lower-level moisture is quite
plentiful too as dew points across much of the area are in the
upper 40s and lower 50s. The marine layer has deepened
considerably over the past 24 hours and is now over 4000 ft in
depth and quite a bit of stratus and stratocu has spread inland or
will develop early this morning.
The rapidly deepening marine layer yesterday led to a significant
cool down across the region, and this has helped to weaken the
onshore flow as the thermal gradient from the coast to inland has
decreased. Thus, despite the cloud cover many valley areas will
see a rebound in temperatures today.
Expect we`ll see another active day of deep convection over the
mountain areas with lots of moisture (TPW approaching an inch) and
instability still present. Breaks in cloud cover should allow
sufficient surface heating to initiate thunderstorm development
by early afternoon, and presence of mid/upper COL over the region
may allow for more widespread development. Slow movement of the
storms and greater available moisture may result in some locally
heavy rain amounts later today into this evening. Given the amount
of elevated-instability and a favorable easterly steering flow, it
still looks like portions of the valley south of about I-80 will
have a non-zero chance of seeing some showers or an isolated
thunderstorm migrate down from the Sierra foothills late in the
day or this evening.
By Thursday, subtle changes develop in the pattern as we
transition to northwesterly flow with several embedded short-
waves. Normally this pattern would likely mean quite tranquil
weather for most of NorCal, but looks like there will be
sufficient moisture in the flow and lift generated from the
passing waves for a chance of showers Thursday night and again on
Saturday. We`ll continue to monitor trends.
&&
.Extended Discussion (Sunday through Wednesday)
Models build upper ridging inland over Interior NorCal Sunday into
early next week, resulting in above normal temperatures.
GFS/GEM/EC depict a shortwave trough trying to break down the
ridge a bit Tue/Wed. The GEM is the earliest on Tue, while the EC
is the latest on Wed. At any rate, all three models weaken the
trough as it makes landfall, and any chance of precip is limited
to the western Shasta County area. JClapp
&&
.Aviation...
Sct to numerous shwrs/tstms over Sierra this aftn and evening
with isolated to sct over Coastal Range.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
140 PM EDT WED APR 22 2015
.AVIATION...
A WEAK, SLOW MOVING COLD FRONT HAS PUSHED THROUGH THE MIAMI AREA.
THIS HAS KEPT SOME INSTABILITY OVER SOUTH FLORIDA, WHICH HAS
ALLOWED FOR SHOWERS TO PERSIST THROUGH THE DAY. MODELS ARE
INDICATING THAT THERE WILL BE ADDITIONAL INSTABILITY AND AN
ENHANCEMENT OF CONVECTION MAINLY ON THE EASTERN SIDE OF THE AREA,
AND FROM BROWARD COUNTY, SOUTH. SPECIAL UPPER AIR SOUNDINGS
PERFORMED THIS MORNING, HOWEVER, SHOW ONLY A WEAKLY UNSTABLE
ATMOSPHERE, THAT HAS ACTUALLY STABILIZED SOME SINCE 12Z. GIVEN
THIS, AND THE LACK OF ANY LIGHTNING ACROSS SOUTH FLORIDA, HAVE
REMOVED ANY MENTION OF TS FROM THE TAFS. ANOTHER SOUNDING IS BEING
DONE AT THIS TIME, AND IF THAT SHOWS INSTABILITY INCREASING, OR IF
ANY STORMS DO BEGIN TO DEVELOP, THE TS MAY BE ADDED BACK IN. WINDS
WILL CONTINUE TO VARY THROUGH THE OVERNIGHT HOURS AND PICK UP OUT
OF THE SOUTHEAST TOMORROW MORNING.
&&
.PREV DISCUSSION... /ISSUED 1005 AM EDT WED APR 22 2015/
UPDATE...
A FRONTAL BOUNDARY OVER SOUTH FLORIDA THIS MORNING WILL REMAIN
NEARLY STATIONARY THIS AFTERNOON KEEPING THE DEEP TROPICAL
MOISTURE IN PLACE OVER SOUTH FLORIDA. THE WEST AND EAST COAST SEA
BREEZES SHOULD ALSO DEVELOP THIS AFTERNOON WITH THE WEST COAST
SEA BREEZE PUSHING ACROSS THE AREA. THIS WILL KEEP THE BEST
CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON OVER THE
EASTERN AREAS OF SOUTH FLORIDA WHERE THE SEA BREEZES COLLIDE.
THEREFORE...THE POPS WILL REMAIN IN THE CHANCE TO LIKELY RANGE
WITH THE BEST COVERAGE OVER THE EASTERN AREAS OF SOUTH FLORIDA.
THERE COULD ALSO BE A FEW STRONG STORMS THIS AFTERNOON ESPECIALLY
OVER THE EASTERN AREAS OF SOUTH FLORIDA...AS A SHORT WAVE WILL BE
MOVING THROUGH THE AREA FROM THE GULF OF MEXICO. THE PRIMARY
IMPACTS FROM THE STRONGEST STORMS WILL BE GUSTY WINDS, SMALL HAIL,
HEAVY RAINFALL, AND FREQUENT LIGHTNING STRIKES.
REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES
ARE PLANNED AT THIS TIME.
UPDATE...54/BNB
PREV DISCUSSION... /ISSUED 348 AM EDT WED APR 22 2015/
DISCUSSION...
THE RECENT UPTICK IN STRONG THUNDERSTORMS ACROSS THE REGION THIS
WEEK, IS PARTLY DUE TO THE POSITION OF A ZONAL UPPER JET FROM THE
US/MEXICO BORDER THROUGH THE FLORIDA PANHANDLE. SOUTH FLORIDA HAS
BEEN ON THE SOUTHERN EDGE OF THIS WESTERLY FLOW. THE STRENGTH OF THE
UPPER JET IS UNUSUAL, ROUGHLY 3 STANDARD DEVIATIONS ABOVE NORMAL,
AND IS DRIVEN NOT ONLY BY THE BLOCKY H5 PATTERN ACROSS NORTH
AMERICA, BUT ALSO BY THE UPPER RIDGE OVER THE CARIBBEAN WHICH HAS
DELIVERED MANY OPPRESSIVELY WARM DAYS RECENTLY. HOWEVER, TODAY
CLOUDS WILL BE A MITIGATING FACTOR WITH REGARDS TO STRONG CONVECTIVE
INITIATION, AND PERHAPS THIS IS REFLECTED IN NOT TOO IMPRESSIVE CAPE
VALUES FROM MODEL SOUNDINGS. IN CONTRAST, RUC13 SOUNDINGS DO HAVE 0-
6KM SHEAR VALUES NEAR 45 M/S AND H7-H5 LAPSE RATES 6C/KM AT MIA BY
LATE MORNING. A SHRTWV ARRIVING FROM THE GULF OVERNIGHT HAS KEPT
NORTHERN ZONES WET, AND MOISTURE WILL CONTINUE TO BE ABUNDANT SOUTH
OF THE DWINDLING FRONT OVER LAKE OKEECHOBEE. NUMEROUS SHOWERS AND
THUNDERSTORMS, NOW ENTERING THE FLORIDA STRAITS, MAY ALSO COMPLICATE
MATTERS THIS MORNING. ANY BREAKS IN THE CLOUDINESS THIS AFTERNOON,
CAN VERY WELL LEAD TO STRONG THUNDERSTORMS. MODELS FOCUSING HIGHEST
POP ACROSS BROWARD AND MIAMI-DADE TODAY. PWATS AROUND 2" AND LITTLE
DIRECTIONAL SHEAR THROUGH THE COLUMN WILL MAKE TRAINING OF STORMS
AND VERY HEAVY RAINFALL POSSIBLE.
THURSDAY LOOKS SIMILAR TO TODAY, WITH THE ONLY DIFFERENCE A SLIGHT
BACKING OF MID AND UPPER LEVEL WINDS. THE VERY SUBTLE CAA THIS
PROVIDES ALOFT MAY ENHANCE LAPSE RATES A TAD. MORNING CLOUDS MAY NOT
BE AS MUCH OF AN ISSUE AS THEY ARE TODAY, AS PRECIP TONIGHT LOOKS
LESS COMPARED TO WHAT IS HAPPENING THIS MORNING.
HIGH PRESSURE MOVING INTO THE SOUTHEASTERN CONUS SHOULD DELIVER A
SLUG OF RELATIVELY DRIER AIR IN THE MIDLEVELS ON FRIDAY. THIS
COMBINED WITH SLIGHTLY WARMING H5 TEMPS SHOULD LEAD TO LESS COVERAGE
AND STORMS FOCUSED MORE INLAND WITH CONVERGING SEA BREEZES. EVEN
DRIER AIR ARRIVES THIS WEEKEND AND PWATS CONTINUE TO SLOWLY FALL.
HOWEVER, RISING H85 TEMPS TO +19C MEAN 90F POTENTIALLY FOR ALL THE
BIG CITIES AGAIN, ESPECIALLY ON SUNDAY. THE QUIETER PATTERN SHOULD
LAST INTO EARLIER NEXT WEEK. ALTHOUGH SEVERAL DAYS AWAY, BOTH THE
GFS/ECMWF ARE BULLISH REGARDING A DEEP EASTERN TROUGH AND A NEARING
COLD FRONT AT THE END OF THE FORECAST.
MARINE...
ALTHOUGH WINDS WILL REMAIN BELOW 15 KTS AND SEAS NO GREATER THAN 3
FEET THROUGH THE FORECAST, SHOWERS AND THUNDERSTORMS MAY BE NUMEROUS
AT TIMES TODAY AND THURSDAY. SOME OF WHICH COULD BE STRONG. WIND
DIRECTION WILL BECOME INCREASINGLY SW AND W THROUGH THE WEEKEND FROM
10-15 KTS BY SUNDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 70 88 72 88 / 30 50 20 20
FORT LAUDERDALE 74 87 74 88 / 40 50 20 30
MIAMI 74 90 75 89 / 40 50 20 30
NAPLES 72 86 74 87 / 10 20 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...54/BNB
LONG TERM....10/CD
AVIATION...13/SI
AREA FORECAST DISCUSSION
NWS GOODLAND KS
324 PM MDT WED APR 22 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 225 PM MDT WED APR 22 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS
NORTHERN AND SOUTHERN JET STREAMS SPLIT AROUND OUR CWA...WITH WEAK
RIDGING EXTENDING FROM THE SOUTHERN PLAINS AND ACROSS THE CENTRAL
ROCKIES. PACIFIC MOISTURE PLUME IS UNDERCUTTING UPPER RIDGE WITH
WEAK SHORTWAVE TROUGHS ROTATING NORTH AND EAST THROUGH THE
SOUTHERLY STORM TRACK. AT THE SURFACE A STATIONARY FRONT HAS
SLOWLY BEGUN THE PROCESS OF MOVING EAST WITH RADAR SHOWING
CONVECTION DEVELOPING IN THE WEAKLY UNSTABLE AIR MASS BEHIND THIS
FEATURE OVER THE HIGHER TERRAIN IN COLORADO.
THIS AFTERNOON TONIGHT...INITIAL CONCERN IS ON COVERAGE AND
PROGRESS OF THUNDERSTORM ACTIVITY IN COLORADO TOWARDS OUR CWA.
GUIDANCE SHOWS INCREASING INSTABILITY IN OUR WESTERN CWA...WHICH
COULD FAVOR THIS ACTIVITY MAKING AS FAR EAST AS THE CO/KS STATE
LINE. WHILE MOST OF THIS ACTIVITY WILL BE TIED TO DAYTIME
HEATING...WAA OVERNIGHT AND NOSE OF LLJ COULD SUPPORT
THUNDERSTORM LINGERING LATE THIS EVENING...OR SHOWERS AFTER
MIDNIGHT AS INSTABILITY WANES. MID LEVELS ARE NOT PARTICULARLY
MOIST AND DESPITE VERY GOOD OVERNIGHT MOISTURE ADVECTION WITHIN
THE BOUNDARY LAYER CAP ABOVE THIS WOULD LIKELY LIMIT CONVECTIVE
POTENTIAL FOR ANY NON ELEVATED PARCELS. I KEPT SLIGHT CHANCE OF
THUNDERSTORMS IN THE EVENING WITH SHOWERS LINGERING AFTER
MIDNIGHT THROUGH THURSDAY MORNING. CONSIDERING THE NEAR SATURATED
BOUNDARY LAYER THE PRECIP SIGNAL IN GUIDANCE MAY ACTUALLY BE
DRIZZLE/FOG.
THURSDAY...NAM SOUNDINGS INDICATE POTENTIAL FOR LINGERING
STRATUS/DRIZZLE DURING THE DAY...HOWEVER OVERALL PATTERN SHOULD
SUPPORT CLEARING SKIES FROM THE WEST WITH WARMER CONDITIONS ACROSS
EASTERN COLORADO. A STRONGER SHORTWAVE TROUGH WILL BEGIN TO MOVE
INTO THE CWA FROM THE WEST WITH INCREASING THUNDERSTORM CHANCES
ONCE AGAIN IN EASTERN COLORADO WHERE BETTER INSTABILITY IS
ADVERTISED ALONG WITH STRONGER LIFT. CONFIDENCE WAS HIGH ENOUGH
TO KEEP CHANCE POPS IN PLACE LATE THURSDAY AFTERNOON. HIGH
TEMPERATURES THURSDAY WILL BE TRICKY AND HIGHLY DEPENDENT ON
STRATUS CLEARING. HIGHS NEAR 70F (MAINLY IN THE WEST) ARE POSSIBLE
WHERE BEST CHANCE FOR CLEAR SKIES IS CURRENTLY ANTICIPATED.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 232 PM MDT WED APR 22 2015
THE UPPER RIDGE AXIS EXTENDING FROM THE GULF OF MEXICO THROUGH
THE NORTHERN HIGH PLAINS FLATTENS SOMEWHAT LATE THURSDAY INTO
THURSDAY NIGHT AS A SHORT WAVE TROUGH MOVES OUT OF THE SOUTHWEST
U.S. AND OVER THE CENTRAL PLAINS THURSDAY NIGHT. THE LEE SURFACE
TROUGH ALONG THE FRONT RANGE THAT DEEPENS IN RESPONSE TO THE UPPER
SHORT WAVE TROUGH HAS GOOD SOUTHEASTERLY FLOW AHEAD OF IT THAT
WILL BRING AMPLE GULF MOISTURE INTO THE REGION. SCATTERED STRONG
THUNDERSTORMS ARE POSSIBLE ACROSS THE FORECAST AREA THURSDAY NIGHT
AS A RESULT
THE MAIN UPPER TROUGH AXIS BEGINS TO LIFT OUT ACROSS THE
4-CORNERS REGION AND INTO THE CENTRAL AND SOUTHERN HIGH PLAINS
REGION BY FRIDAY AFTERNOON...WITH THE CENTROID OF THE TROUGH
MOVING OVER E CO/NW KS. DEWPOINTS IN THE 40S ACROSS THE AREA ON
THURSDAY AND THURSDAY NIGHT WILL INCREASE INTO THE LOWER 50S
ACROSS MAINLY THE EASTERN PORTION OF THE FORECAST AREA WHILE DRYER
AIR MOVES INTO THE WEST AS THE TROUGH MOVES EAST AND FORMS A
CLOSED LOW THAT MOVES ACROSS SOUTHERN KANSAS FRIDAY EVENING. WITH
AN INSTABILITY AXIS PRESENT OVER CENTRAL KANSAS...IT IS POSSIBLE
THE FORECAST AREA COULD SEE SOME STRONG TO SEVERE THUNDERSTORMS
MAINLY ACROSS THE FAR EASTERN SECTIONS THAT WILL BECOME MORE
WIDESPREAD AND STRONGER OVERNIGHT AS THEY MOVE FURTHER TO THE
EAST.
SHORT WAVE RIDGING IS EXPECTED BETWEEN THE EXITING TROUGH AS IT
LIFTS OUT OF THE REGION AND THE NEXT UPPER TROUGH THAT STARTS TO
DEEPEN OVER THE INTERMOUNTAIN WEST BETWEEN SATURDAY AND SATURDAY
EVENING. MODEL SOLUTIONS HAVE A LOW CENTER CONSOLIDATING AND
MOVING QUICKLY ACROSS NEW MEXICO SUNDAY EVENING. THEN AS MODEL
SOLUTIONS BEGIN TO DIVERGE TO A GREATER DEGREE...THE LOW SLOWS AND
ENDS UP SOMEWHERE OVER E OKLAHOMA/E TEXAS BY TUESDAY MORNING AS A
BLOCKING HIGH AMPLIFIES OVER THE WESTERN UNITED SATES. THAT RIDGE
MOVES OVER THE ROCKIES AND HIGH PLAINS REGION BY WEDNESDAY
EVENING. THE WEEKEND AND FIRST PART OF NEXT WEEK WILL REMAIN
UNSETTLED WITH SCATTERED THUNDERSTORMS POSSIBLE ACROSS THE AREA AS
THE LOW MOVES ACROSS THE SOUTHERN PLAINS. DRYER AND WARMER
CONDITIONS ARE ANTICIPATED BY MID-WEEK AS SURFACE HIGH PRESSURE
AND THE RIDGE ALOFT MOVE OVER THE HIGH PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1121 AM MDT WED APR 22 2015
VFR CONDITIONS WILL PREVAIL THROUGH THE FIRST 12 HOURS OF THE TAF
PERIOD AT BOTH KGLD AND KMCK WITH PRIMARY AVIATION CONCERN BEING
POTENTIAL FOR ISOLATED THUNDERSTORMS OR SHOWERS. WHILE KGLD HAS
THE BEST CHANCE FOR THUNDERSTORM ACTIVITY TO SPREAD EAST OUT OF
COLORADO...CONFIDENCE IN COVERAGE IS STILL TOO LOW FOR TAF
INCLUSION AT THIS TIME.
INCREASING LOW LEVEL MOISTURE ALONG STALLED FRONTAL BOUNDARY LATE
TONIGHT WILL SUPPORT STRATUS AND POSSIBLY LIGHT FOG DEVELOPMENT BY
09Z AT KGLD...TRANSITIONING EAST THROUGH THURSDAY MORNING. WITH
GUIDANCE SHOWING BETTER CONSISTENCY I ADDED IFR CIG GROUP TO KGLD
TAF AFTER 09Z AND KEPT MENTION OF MVFR CIGS AT KMCK AFTER 15Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
225 PM MDT WED APR 22 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 225 PM MDT WED APR 22 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS
NORTHERN AND SOUTHERN JET STREAMS SPLIT AROUND OUR CWA...WITH WEAK
RIDGING EXTENDING FROM THE SOUTHERN PLAINS AND ACROSS THE CENTRAL
ROCKIES. PACIFIC MOISTURE PLUME IS UNDERCUTTING UPPER RIDGE WITH
WEAK SHORTWAVE TROUGHS ROTATING NORTH AND EAST THROUGH THE
SOUTHERLY STORM TRACK. AT THE SURFACE A STATIONARY FRONT HAS
SLOWLY BEGUN THE PROCESS OF MOVING EAST WITH RADAR SHOWING
CONVECTION DEVELOPING IN THE WEAKLY UNSTABLE AIR MASS BEHIND THIS
FEATURE OVER THE HIGHER TERRAIN IN COLORADO.
THIS AFTERNOON TONIGHT...INITIAL CONCERN IS ON COVERAGE AND
PROGRESS OF THUNDERSTORM ACTIVITY IN COLORADO TOWARDS OUR CWA.
GUIDANCE SHOWS INCREASING INSTABILITY IN OUR WESTERN CWA...WHICH
COULD FAVOR THIS ACTIVITY MAKING AS FAR EAST AS THE CO/KS STATE
LINE. WHILE MOST OF THIS ACTIVITY WILL BE TIED TO DAYTIME
HEATING...WAA OVERNIGHT AND NOSE OF LLJ COULD SUPPORT
THUNDERSTORM LINGERING LATE THIS EVENING...OR SHOWERS AFTER
MIDNIGHT AS INSTABILITY WANES. MID LEVELS ARE NOT PARTICULARLY
MOIST AND DESPITE VERY GOOD OVERNIGHT MOISTURE ADVECTION WITHIN
THE BOUNDARY LAYER CAP ABOVE THIS WOULD LIKELY LIMIT CONVECTIVE
POTENTIAL FOR ANY NON ELEVATED PARCELS. I KEPT SLIGHT CHANCE OF
THUNDERSTORMS IN THE EVENING WITH SHOWERS LINGERING AFTER
MIDNIGHT THROUGH THURSDAY MORNING. CONSIDERING THE NEAR SATURATED
BOUNDARY LAYER THE PRECIP SIGNAL IN GUIDANCE MAY ACTUALLY BE
DRIZZLE/FOG.
THURSDAY...NAM SOUNDINGS INDICATE POTENTIAL FOR LINGERING
STRATUS/DRIZZLE DURING THE DAY...HOWEVER OVERALL PATTERN SHOULD
SUPPORT CLEARING SKIES FROM THE WEST WITH WARMER CONDITIONS ACROSS
EASTERN COLORADO. A STRONGER SHORTWAVE TROUGH WILL BEGIN TO MOVE
INTO THE CWA FROM THE WEST WITH INCREASING THUNDERSTORM CHANCES
ONCE AGAIN IN EASTERN COLORADO WHERE BETTER INSTABILITY IS
ADVERTISED ALONG WITH STRONGER LIFT. CONFIDENCE WAS HIGH ENOUGH
TO KEEP CHANCE POPS IN PLACE LATE THURSDAY AFTERNOON. HIGH
TEMPERATURES THURSDAY WILL BE TRICKY AND HIGHLY DEPENDENT ON
STRATUS CLEARING. HIGHS NEAR 70F (MAINLY IN THE WEST) ARE POSSIBLE
WHERE BEST CHANCE FOR CLEAR SKIES IS CURRENTLY ANTICIPATED.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 243 AM MDT WED APR 22 2015
PRECIP WILL MOVE OUT OF THE AREA SATURDAY MORNING BEFORE A TROUGH
ENTERS THE AREA LATE SATURDAY/EARLY SUNDAY. THIS WILL PRODUCE
ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS SATURDAY NIGHT AND
SUNDAY. MODELS HAVE TRENDED STRONGER WITH THIS SYSTEM...INCREASING
PRECIPITATION PROBABILITY. PRECIP CHANCE CONTINUES INTO MONDAY AS
AN UPPER LEVEL LOW CLOSES OFF AND MOVES EAST.
TEMPERATURES LOOK TO BE RELATIVELY CONSISTENT AND IN THE 60S
THROUGH MONDAY. A RIDGE WILL BEGIN TO MOVE INTO THE AREA ON
TUESDAY BRINGING DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1121 AM MDT WED APR 22 2015
VFR CONDITIONS WILL PREVAIL THROUGH THE FIRST 12 HOURS OF THE TAF
PERIOD AT BOTH KGLD AND KMCK WITH PRIMARY AVIATION CONCERN BEING
POTENTIAL FOR ISOLATED THUNDERSTORMS OR SHOWERS. WHILE KGLD HAS
THE BEST CHANCE FOR THUNDERSTORM ACTIVITY TO SPREAD EAST OUT OF
COLORADO...CONFIDENCE IN COVERAGE IS STILL TOO LOW FOR TAF
INCLUSION AT THIS TIME.
INCREASING LOW LEVEL MOISTURE ALONG STALLED FRONTAL BOUNDARY LATE
TONIGHT WILL SUPPORT STRATUS AND POSSIBLY LIGHT FOG DEVELOPMENT BY
09Z AT KGLD...TRANSITIONING EAST THROUGH THURSDAY MORNING. WITH
GUIDANCE SHOWING BETTER CONSISTENCY I ADDED IFR CIG GROUP TO KGLD
TAF AFTER 09Z AND KEPT MENTION OF MVFR CIGS AT KMCK AFTER 15Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JBH
AVIATION...DR
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
141 PM CDT WED APR 22 2015
.AVIATION...
CLUSTER OF TSTMS CURRENTLY OVER SW AR IS EXPECTED TO MOVE EWD OVER
THE NEXT FEW HOURS...BUT SHOULD NOT IMPACT ANY TERMINALS ASIDE
FROM KTXK. LATER TONIGHT...TSTMS ARE EXPECTED TO DEVELOP ACROSS
THE RED RIVER AND MOVE SEWD INTO OUR REGION. THERE IS QUITE A BIT
OF UNCERTAINTY AS TO THE TIMING AND LOCATION OF THESE STORMS...SO
WILL KEEP MENTION OF TSTMS OUT OF THE TAFS ASIDE FROM THE USE OF
VCTS. OTHERWISE...WITH INCREASING LL MOISTURE TO CONTINUE...
STRATUS DEVELOPMENT IS EXPECTED FOR MOST SITES AFTER AROUND
09Z...WITH SOME IMPROVEMENT POSSIBLE AFTER SUNRISE. /12/
&&
.PREV DISCUSSION... /ISSUED 1038 AM CDT WED APR 22 2015/
DISCUSSION...
WEAKENING MCS MOVG INTO RED RIVER VALLEY. GOOD DAYTIME HEATING
WILL CONTINUE AHEAD OF THE DECAYING SYSTEM OUTFLOW THAT WILL PUSH
EASTWARD INTO SW AR/NW TX AND NW LA THIS AFTN. BETWEEN AIRMASS
RECOVERY ACROSS NORTHERN AREAS NEAR THIS MCS...AND MARGINAL
MOISTURE IN UNSTABLE AIRMASS ACROSS REST OF AREA...EXPECT STG
CONVECTIVE REDEVELOPMENT TO OCCUR LATE AFTN/EARLY EVE.
THUS...LOWERED POPS SLIGHTLY TO 20 AND 30 PERCENT FOR MOST OF
NORTHERN LA...AND PORTIONS OF NE TX ALONG AND SOUTH OF I-20.
ALSO RAISED TEMPS SLIGHTLY TO LOWER/MID 80S ACROSS ROUGHLY THESE
SAME AREAS WHERE POPS HAVE BEEN LOWERED./VII/.
PREV DISCUSSION... /ISSUED 538 AM CDT WED APR 22 2015/
DISCUSSION...
AIR MASS MODIFICATION IS UNDERWAY THIS MORNING...WITH AN EXTENSIVE
BAND OF 5-6KFT CIGS HAVING DEVELOPED/SPREAD ENE ALONG AND S OF THE
I-20 CORRIDOR OF N LA/E TX. LOW LEVEL WARM/MOISTURE ADVECTION WILL
CONTINUE TODAY...AS A SLY LOW LEVEL FLOW INCREASES...AHEAD OF SFC
LOW PRESSURE THAT WILL DEEPEN BY AFTERNOON ALONG THE DRY LINE OVER
NW TX. THIS WILL DRIVE A WARM FRONT NWD TO NEAR THE RED RIVER OF N
TX ESE ACROSS NE TX AND TO NEAR THE AR/LA LINE BY AFTERNOON.
MEANWHILE...A WEAK COLD FRONT WILL DRIFT S TODAY BEFORE
TEMPORARILY BECOMING STATIONARY FROM SRN OK INTO CNTRL AR. THE
MORNING WATER VAPOR IMAGERY REVEALS A SHORTWAVE ROUNDING THE
BACKSIDE OF A LARGE UPPER CLOSED LOW/ATTENDANT LONGWAVE TROUGH
EXTENDING FROM THE NRN GREAT LAKES SW THROUGH THE MIDWEST INTO THE
OK/TX PANHANDLE. THIS SHORTWAVE HAS BEEN DRIVING AN INCREASE IN
ELEVATED CONVECTION ALONG THE FRONT OVER WRN OK...WHICH SHOULD
CONTINUE TO SPREAD SSE ALONG THE FRONTAL ZONE THIS MORNING.
ADDITIONAL REDEVELOPMENT SHOULD OCCUR LATER TODAY AS CONVERGENCE
INCREASES ALONG THE TRIPLE POINT NEAR THE RED RIVER...AND LARGE
SCALE FORCING INCREASES ALONG A SECONDARY SHORTWAVE ON THE WATER
VAPOR IMAGERY OVER SRN NM THAT WILL LIFT NE INTO THE TX PANHANDLE
ATOP THE FLAT SRN PLAINS RIDGE AND ACROSS THE RED RIVER VALLEY.
THE AIR MASS ACROSS THE WARM SECTOR IS EXPECTED TO BECOME
MODERATELY UNSTABLE THIS AFTERNOON...CHARACTERIZED BY MLCAPES OF
1500-2500 J/KG AND STEEP LAPSE RATES. IT REMAINS TO BE SEEN THOUGH
WHETHER THE CURRENT WRN OK CONVECTION MAY HELP INITIATE CONVECTION
EARLIER OVER THE RED RIVER VALLEY...BEFORE MAX DESTABILIZATION
OCCURS...THUS TAPERING THE POTENTIAL INSTABILITY. THE 00Z PROGS
ARE NOT IN GOOD AGREEMENT AT ALL IN REGARDS TO CONVECTION
PLACEMENT/TIMING...ALTHOUGH THE NEW 06Z NAM HAS TRENDED CLOSER TO
THE GFS SOLUTION WITH CONVECTION INCREASING ALONG THE WARM FRONT
OVER NE TX DURING PEAK HEATING. MEANWHILE...THE HRRR IS SUGGESTING
LITTLE IF ANY DEVELOPMENT THIS AFTERNOON NEAR THE TRIPLE
POINT...WITH MORE WIDESPREAD CONVECTION DEVELOPING E OF I-35
ACROSS ECNTRL TX BY MID TO LATE AFTERNOON. NEEDLESS TO
SAY...CONFIDENCE IS LOWER TODAY THAN TUESDAY IN REGARDS TO
CONVECTION INITIATION AND PLACEMENT.
DID MAINTAIN HIGH CHANCE POPS WITH SVR WORDING THIS AFTERNOON NW
OF THE I-30 CORRIDOR ALONG/JUST N OF THE WARM FRONT...TAPERING
CHANCE POPS DOWN A TAD FARTHER E WHERE FRONTAL CONVERGENCE IS A
BIT WEAKER AND THIS REGION IS FARTHER REMOVED FROM THE TWO LOBES
OF SHORTWAVE ENERGY TO OUR N AND W. AN MCS MAY DEVELOP THIS
EVENING ALONG THE RED RIVER VALLEY AND SHIFT ESE ALONG THE FRONT
TONIGHT /PER THE CONSISTENT GFS SOLUTION AND TO SOME EXTENT THE
ECMWF/...WITH THE THREAT OF DAMAGING WINDS/LARGE HAIL POSSIBLE.
DID CONTINUE MENTION OF SVR OVERNIGHT AREAWIDE GIVEN THE
UNCERTAINTY...ALTHOUGH THIS THREAT SHOULD DIMINISH LATE WITH THE
STABILIZING BNDRY LYR. THE SHORT TERM PROGS ALSO SUGGEST A
SLIGHTLY FASTER MOVEMENT OF THE COLD FRONT AS IT BEGINS TO
BACKDOOR SW INTO SE OK/SW AR OVERNIGHT...BEFORE PULLING UP
STATIONARY OVER N LA/E TX THURSDAY. WEAK ISENTROPIC ASCENT ATOP
THE BNDRY MAY RESULT IN SCT CONVECTION DURING THE DAY...ALTHOUGH
THE LACK OF UPPER LEVEL ENERGY SHOULD KEEP QPF AMOUNTS LIGHT. IN
ADDITION...MESOSCALE BNDRYS FROM CONVECTION THIS AFTERNOON AND
TONIGHT MAY PLAY A ROLE IN CONVECTION INITIATION THURSDAY ACROSS
THE WARM SECTOR S OF THE FRONT. BUT ATTM...CONFIDENCE IS LOW IN
REGARDS TO THE PLACEMENT OF THE SVR THREAT...THUS HAVE REMOVED SVR
MENTION FROM THE FORECAST THURSDAY...ALTHOUGH CAN/T RULE OUT AN
ISOLATED SVR STORM WITHIN THE MODERATELY UNSTABLE AIR MASS.
WILL BE WATCHING THE CLOSED SRN CA UPPER LOW AS IT EJECTS NE
ACROSS THE FOUR CORNERS REGION AND OPENS UP THURSDAY
NIGHT...ENTERING THE SRN PLAINS FRIDAY. THE WILL SET UP A STRONG
SW FLOW ALOFT...WITH A 70-80KT MID LEVEL SPEED MAX EJECTING OVER
THE SRN PLAINS FRIDAY AFTERNOON. THIS WILL RESULT IN AN INCREASING
SSWLY LOW LEVEL FLOW THURSDAY NIGHT/FRIDAY MORNING...THUS LIFTING
THE STATIONARY FRONT BACK N AS A WARM FRONT ACROSS OK/AR FRIDAY
AND HENCE BROADENING THE WARM SECTOR. THE W TX DRYLINE WILL MIX E
INTO ERN OK TO JUST W OF THE I-35 CORRIDOR OF CNTRL TX FRIDAY
EVENING...WITH BROAD DIFFLUENCE ALOFT CONTRIBUTING TO SCT TO
NUMEROUS CONVECTION AREAWIDE ESPECIALLY DURING PEAK HEATING. LOW
LEVEL WINDS DO VEER MORE ACROSS THE REGION WELL E OF THE DRYLINE
FRIDAY...WITH A MORE UNIDIRECTIONAL FLOW NOTED ABOVE 850MB. GIVEN
THE STRONG DEEP LYR SHEAR AND MODERATE MLCAPES EXPECTED TO BE IN
PLACE...A MORE PRONOUNCED SVR THREAT WILL BE POSSIBLE WITH
DAMAGING WINDS/ISOLATED TORNADOES. MID LEVEL DRY AIR SHOULD ADVECT
ENE AHEAD OF THE EJECTING TROUGH FRIDAY EVENING...THUS TAPERING
THE CONVECTION FROM W TO E OVERNIGHT...WITH THE DRYLINE PULLING UP
STATIONARY JUST W OF THE REGION. THIS BNDRY SHOULD MIX E ACROSS
THE REGION SATURDAY AS WLY WINDS INCREASE BENEATH THE MIDWEST SFC
CYCLONE...RESULTING IN PERHAPS THE WARMEST TEMPS SO FAR THIS
SPRING SEASON AS READING CLIMB WELL INTO THE MID 80S AND POSSIBLY
90 DEGREES OVER PORTIONS OF E TX/N LA.
UPPER RIDGING SHOULD AMPLIFY OVER THE CNTRL CONUS BY SUNDAY BEFORE
THE NEXT CLOSED LOW DIGS SE INTO THE SRN ROCKIES SUNDAY BEFORE
MOVING INTO THE SRN PLAINS MONDAY. THIS COULD RESULT IN ANOTHER
SVR THREAT FOR THE REGION BY THE MONDAY/TUESDAY
TIMEFRAME...ALTHOUGH DISCREPANCIES IN TIMING AMONGST THE FASTER
GFS/SLOWER ECMWF PRECLUDES A HIGHER CONFIDENCE ATTM. HOWEVER...THE
PROGS DO CONVERGE ON A PATTERN CHANGE BY MID AND LATE WEEK...WITH COOLER
AND DRIER CONDITIONS SPILLING S ACROSS THE ERN TWO-THIRDS OF THE
CONUS.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 82 64 77 67 / 30 70 40 30
MLU 83 63 77 64 / 20 70 40 20
DEQ 76 58 67 58 / 50 70 40 40
TXK 77 60 71 62 / 40 70 40 30
ELD 80 60 71 60 / 30 70 40 30
TYR 79 65 81 69 / 40 60 30 40
GGG 80 65 80 69 / 30 60 30 40
LFK 84 68 85 71 / 30 50 30 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
12
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
645 PM EDT WED APR 22 2015
.SYNOPSIS...
LOW PRESSURE TRACKS EASTWARD THROUGH NORTHERN NEW ENGLAND
WEDNESDAY NIGHT SENDING ANOTHER COLD FRONT THROUGH THE AREA. LOW
PRESSURE LINGERS OVER NORTHERN NEW ENGLAND THROUGH THE WEEKEND
AND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
UPDATE...MONITORING AN AREA OF SHOWERS LIFTING NWD OUT OF MA AT
THIS HOUR. OF CONCERN ARE THE STEEP LOW LEVEL LAPSE RATES IN PLACE
OVER MUCH OF SRN NH. WITH LAPSE RATES APPROACHING 8.5 C/KM
ACCORDING TO THE LATEST RAP MESOANALYSIS...IT WILL NOT TAKE MUCH
CONVECTIVE TO GET GUSTY WINDS TO THE SURFACE. UPSTREAM OBS OF 40
PLUS KT GUSTS AT KORH AND SOME TREE DAMAGE HIGHLIGHT THIS
POTENTIAL EVEN FURTHER. NOT SEEING ANY LIGHTNING CURRENTLY...BUT
WILL HIGHLIGHT GUSTY WINDS IN THE GRIDS THRU 00Z.
RAIN SHOWERS INCREASING OVER NEW HAMPSHIRE AND WESTERN MAINE LATE
THIS AFTERNOON AS AN UPPER LOW OVER THE GREAT LAKES AND A WEAK
COLD FRONT MOVES CLOSER. SOME OF THE RADAR RETURNS ARE HAVING
TROUBLE TRANSLATING TO THE GROUND THIS AFTERNOON OVER NEW
HAMPSHIRE AND WESTERN MAINE, WITH MOST OF THE MORE SIGNIFICANT RAIN
BEING BACK IN VERMONT AND UPSTATE NEW YORK. ATMOSPHERE WILL
GRADUALLY MOISTEN AND MOST AREAS WILL GET SHOWERS THIS EVENING,
DECREASING IN COVERAGE AND BECOMING MORE SCATTERED FROM WEST TO
EAST LATER IN THE NIGHT AS THE COLD FRONT PASSES THROUGH. NOT A
TERRIBLY SIGNIFICANT RAIN EVENT WITH GENERALLY A QUARTER TO HALF
INCH, LOCALLY MORE IN THE MOUNTAINS.
LOOKING FOR ISOLATED TO SCATTERED SHOWERS ON THURSDAY, WITH THE
BETTER CHANCE OF SHOWERS BEING INLAND CLOSER TO THE UPPER LOW
WHICH WILL MOVE FROM THE GREAT LAKES THIS AFTERNOON TO FAR
SOUTHERN QUEBEC THURSDAY. THURSDAY WILL BE A COOL, BREEZY DAY WITH
HIGHS IN THE MID 40S TO LOW 50S LOWER ELEVATIONS.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH 6 PM THURSDAY/...
A CLOSED UPPER LOW OVER THE REGION WILL REMAIN GENERALLY
STATIONARY THROUGH THE PERIOD AS BLOCKING PERSISTS IN THE
ATLANTIC. THIS LOW WILL GENERATE DIURNALLY DRIVEN INSTABILITY SHOWERS.
WITH NORTHWEST WINDS AND DOWNSLOPING...EXPECT DRIER CONDITIONS
DOWNWIND OF THE WESTERN MAINE AND NORTHERN NEW HAMPSHIRE
MOUNTAINS. IN SPITE OF H850 MOISTURE...THE DOWNSLOPING SHOULD
PRODUCE SOME PERIODS OF SUNSHINE FRIDAY AND SATURDAY. A WELL-
MIXED ATMOSPHERE WILL GENERATE GUSTY WINDS ON FRIDAY THAT WILL
REACH 20 MPH. IN THE MOUNTAINS...EXPECT UPSLOPE CONDITIONS AS
MOISTURE WRAPS AROUND THE UPPER LOW THROUGH THE ST LAWRENCE
VALLEY. THIS WILL PRODUCE MOSTLY CLOUDY SKIES WITH SHOWERS THROUGH
THE PERIOD. TEMPERATURES WILL BE COLD ENOUGH TO SUPPORT SNOW
SHOWERS LATER THURSDAY NIGHT INTO EARLY FRIDAY MORNING FOR THE
MOUNTAINS OF WESTERN MAINE AND NORTHERN NEW HAMPSHIRE.
TEMPERATURES WILL BE COOL THURSDAY NIGHT INTO SATURDAY WITH HIGHS
IN THE 40S IN THE MOUNTAINS AND INCREASING TOWARDS THE LOW-MID 50S
ALONG THE COASTAL PLAIN. LOWS WILL RANGE FROM THE UPPER 20S TO
LOWER 30S ON FRIDAY MORNING AND WILL DROP INTO THE 30S AGAIN ON
FRIDAY NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THE LONGER TERM FROM SATURDAY NIGHT THROUGH THURSDAY CONTINUES TO
FEATURE THE STAGNANT CLOSED UPPER LOW WITH COOL CONDITIONS AND
DIURNALLY-DRIVEN SHOWER ACTIVITY. HAVE FOLLOWED THE SUPER BLEND
VERY CLOSELY. INCREASED POPS FOR PORTLAND AND THE COASTAL PLAIN
FOR MONDAY AS THE UPPER LOW IS EXPECTED TO MOVE DIRECTLY OVER THE
FORECAST AREA. THESE SHOWERS WILL LINGER INTO TUESDAY...BUT THE
TREND TOWARDS LATER TUESDAY WILL BE FOR THE UPPER LOW TO SLIDE
EASTWARD AND ALLOW AN UPPER RIDGE TO BUILD.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
NEAR TERM...
MVFR CONDITIONS EXPECTED FOR MOST AREAS THIS EVENING WITH THE
SHOWER ACTIVITY, ALTHOUGH SOME SPOTS COULD STAY JUST ABOVE MVFR
LEVELS MAINLY IN SOUTHERN NEW HAMPSHIRE. MOST AREAS WILL BE VFR ON
WEDNESDAY ALTHOUGH LOCALIZED MVFR IS EXPECTED IN ANY OF THE
SCATTERED SHOWERS.
SHORT TERM...
EXPECT MOSTLY VFR OUTSIDE OF SHOWER ACTIVITY THROUGH THE PERIOD.
&&
.MARINE...
NEAR TERM...
EXPECT SMALL CRAFT FOR WINDS AND SEAS TONIGHT FOR ALL BUT INNER
WATERS JUST AHEAD OF A WEAK COLD FRONT. THE WINDS WILL SUBSIDE A
BIT ON THURSDAY, BUT THE SEAS WILL REMAIN ABOVE 5 FEET AWAY FROM
THE IMMEDIATE COAST.
SHORT TERM...
NO HEADLINES EXPECTED THROUGH THE PERIOD. VERY STABLE CONDITIONS
CONTINUE OVER THE WATERS AND THE WIND FORECAST MAY NEED TO BE
TRIMMED THURSDAY NIGHT AND FRIDAY.
&&
.FIRE WEATHER...
GENERALLY WET AND COOL WEATHER IS EXPECTED FOR THE REMAINDER OF
THE WEEK.
&&
.HYDROLOGY...
FLOOD WARNING REMAINS IN EFFECT FOR THE KENNEBEC AT AUGUSTA. AFTER
THIS HIGH TIDE CYCLE...RIVER LEVELS SHOULD REMAIN BELOW FLOOD
STAGE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR ANZ150-152-
154.
&&
$$
NEAR TERM...LEGRO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
356 PM EDT WED APR 22 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 344 PM EDT WED APR 22 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO/
POCKET OF H5 TEMPS NEAR -30C CENTERED OVER ONTARIO TO THE SW OF
JAMES BAY DOWNSTREAM OF HI AMPLITUDE RDG OVER THE ROCKIES. DEEP
MOIST CYC NW FLOW ARND THE CLOSED LO CONTINUES TO IMPACT UPR MI...
DRAWING UNSEASONABLY CHILLY AIR /H85 TEMPS AS LO AS -12 TO -14C THAT
ARE SUFFICIENTLY COLD FOR LES/ INTO THE AREA. THE RESULT HAS BEEN
NMRS SN SHOWERS THAT HAVE BEEN EXACERBATED OVER LAND WITH DAYTIME
HEATING EVEN IN THE ABSENCE OF SGNFT LARGER SCALE FORCING/DEEP LYR
QVECTOR CNVGC.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMOUNTS
ESPECIALLY TNGT AS UPR LO DRIFTS SLOWLY TO THE E. TEMPS WL REMAIN
BLO NORMAL THRU THU.
TNGT...UPR LO IS FCST TO DRIFT SLOWLY TO THE E...ALLOWING FOR SLOWLY
RISING H5 HGT/WEAKENING LLVL CYC FLOW. ALTHOUGH SOME GENERAL LARGER
SCALE SUBSIDENCE IS FCST TO DOMINATE...H85 TEMPS REMAINING AS LO AS
ABOUT -13C IN THE PRESENCE OF SOME LINGERNING DEEP MSTR/NOCTURNAL
COOLING WL BE SUFFICIENT TO MAINTAIN LES IN THE FAVORED NW WIND SN
BELTS OVER THE ERN CWA. EXPECT UP TO A COUPLE INCHES OF SN ACCUM IN
THIS AREA. OVER THE W...WARMING H85 TEMPS TO ARND -10C/ LOWERING
SUBSIDENCE INVRN UNDER THE GREATER HGT RISES SHOULD TEND TO CAUSE
THE SN SHOWERS TO DIMINISH IN THAT AREA. HOWEVER...THE PERSISTENT
UPSLOPE NW FLOW AND LINGERING UPSLOPE FLOW WL ALLOW FOR AT LEAST
SOME SCT SN SHOWERS EVEN IN THAT AREA.
THU...PERSISTENT HGT RISES AND SUBSIDENCE/TENDENCY FOR THE LLVL FLOW
TO BECOME MORE ACYC AS WELL AS SOME LLVL DRYING IN THE PRESENCE OF
DAYTIME HEATING WL DIMINISH THE SN SHOWERS W-E. FCST SDNGS INDICATE
THERE WL BE SOME SUNSHINE IN THE AFTN AS WELL WITH HI PRES RDG FCST
TO BLD INTO THE WRN CWA LATER IN THE DAY. TEMPS SHOULD REBOUND INTO
THE 40S OVER THE INTERIOR W AND SCENTRAL AWAY FM LK MODERATION WITH
H85 TEMPS PROGGED TO REACH NEAR -6C ALONG THE WI BORDER BY 00Z FRI.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM EDT WED APR 22 2015
EVEN AS A SFC RIDGE MOVES IN FROM THE W THU NIGHT...ISOLATED SNOW
SHOWERS SHOULD LINGER INTO THE NIGHT IN NW WIND SNOWBELTS NEAR ERN
LAKE SUPERIOR. THIS AS 850MB TEMPS WILL BE AROUND -10C UNDER NW
WINDS. BY FRI MORNING...THE INCREASING INFLUENCE OF THE RIDGE AND
THE WARNING AIRMASS OVERHEAD WILL MAKE FOR A DRY DAY ACROSS THE U.P.
/RULING AT THE 12Z/22 GFS AS AN OUTLIER WITH THE LIGHT PRECIP OVER
THE FAR W/. CLEARING SKIES FROM W TO E THU NIGHT INTO FRI WILL LEAD
TO MIN TEMPS THU NIGHT IN THE TEENS OVER THE INTERIOR W AND IN THE
20S ELSEWHERE. HIGHS ON FRI WILL RANGE FROM THE MID 30S NEAR
CENTRAL/ERN LAKE SUPERIOR TO THE UPPER 40S ALONG THE WI BORDER.
THE WEEKEND LOOKS DRY...SUNNIER AND WARMER AS A SFC LOW SLIDES WELL
S OF THE CWA WITH SFC AND UPPER RIDGING REMAINING OVER THE CWA.
850MB TEMPS HOVERING AROUND 0C SAT AND SUN COMBINED WITH THE PARTLY
CLOUDS SKIES WILL MAKE FOR HIGHS IN THE 40S TO LOW 50S...COOLEST
NEAR LAKE SUPERIOR OVER AND E OF THE KEWEENAW DUE TO E-NE FLOW OFF
THE LAKE. THE RELATIVELY WEAK FLOW AND MORE LIMITED CLOUD COVER WILL
ALLOW MIN TEMPS SAT AND SUN NIGHTS TO BE IN THE MID 20S INLAND TO
LOW 30S ELSEWHERE.
MON ALSO LOOKS FREE OF PRECIP AS RIDGING WEAKENS BUT REMAINS
OVERHEAD. THE ECMWF SUGGEST THE UPPER LOW CURRENTLY IMPACTING THE
REGION MAY RETROGRADE BACK TOWARD THE AREA AFTER SITTING OVER NEW
ENGLAND...BUT THAT WOULD ONLY LEAD TO LIGHT PRECIP OVER THE E IF
THAT DID OCCUR...BUT WILL LEAVE PRECIP OUT OF THE FORECAST FOR NOW.
850MB TEMPS INCREASE A COUPLE OF DEGREES ON MON...BUT TEMPS SHOULD
BE SIMILAR TO SUN AS CLOUD COVER WILL BE INCREASED.
NOT REAL CONFIDENT FOR TUE AND WED AS MODELS SHOW UPPER LEVEL
IMPULSES MOVING THROUGH THE REGION...BUT THERE IS QUITE A BIT OF RUN
TO RUN AND MODEL TO MODEL DISCONTINUITY DURING THIS TIME AS A MORE
SIGNIFICANT PATTERN SHIFT MAY BE STARTING. PRECIP CHANCES ARE
GREATER THAN FRI-MON...BUT NOT HIGH BY ANY MEANS. TEMPS ON TUE LOOK
TO BE SIMILAR TO TUE...BUT MAY COOL DOWN A BIT ON WED. JUST USED A
CONSENSUS OF GUIDANCE FOR THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 349 PM EDT WED APR 22 2015
EXPECT PREDOMINANT MVFR CONDITIONS WITH CHILLY...MOIST NW FLOW OF
AIR ARND DEEP LO PRES IN SE CANADA THRU TNGT. UNDER THE HEAVIER
SHSN... CONDITIONS THRU THIS AFTN WL BE REDUCED INTO THE IFR RANGE.
THERE WL BE IMPROVEMENT TO VFR CONDITIONS ON THU WITH THE CLOSER
APRCH OF SFC HI PRES AND DRIER AIR UNDER LARGE SCALE SUBSIDENCE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT WED APR 22 2015
A FEW NW WINDS GUSTING TO 30 TO NEAR 35KT GALES WILL REMAIN POSSIBLE
OVER N AND CENTRAL LAKE SUPERIOR THIS EVENING. LOW PRESSURE ACROSS
JAMES BAY WILL FILL LATE TONIGHT AND THURSDAY. THE TROUGH ACROSS
LAKE SUPERIOR THIS MORNING...EXTENDING FROM THE JAMES BAY LOW...WILL
SLOWLY BE REPLACED BY A RIDGE. THIS RIDGE WILL REMAIN IN PLACE FROM
FRIDAY THROUGH SUNDAY...EXTENDING FROM STRONG HIGH OVER FAR NORTHERN
CANADA AND GREENLAND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...KC
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
349 PM EDT WED APR 22 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 344 PM EDT WED APR 22 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO/
POCKET OF H5 TEMPS NEAR -30C CENTERED OVER ONTARIO TO THE SW OF
JAMES BAY DOWNSTREAM OF HI AMPLITUDE RDG OVER THE ROCKIES. DEEP
MOIST CYC NW FLOW ARND THE CLOSED LO CONTINUES TO IMPACT UPR MI...
DRAWING UNSEASONABLY CHILLY AIR /H85 TEMPS AS LO AS -12 TO -14C THAT
ARE SUFFICIENTLY COLD FOR LES/ INTO THE AREA. THE RESULT HAS BEEN
NMRS SN SHOWERS THAT HAVE BEEN EXACERBATED OVER LAND WITH DAYTIME
HEATING EVEN IN THE ABSENCE OF SGNFT LARGER SCALE FORCING/DEEP LYR
QVECTOR CNVGC.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMOUNTS
ESPECIALLY TNGT AS UPR LO DRIFTS SLOWLY TO THE E. TEMPS WL REMAIN
BLO NORMAL THRU THU.
TNGT...UPR LO IS FCST TO DRIFT SLOWLY TO THE E...ALLOWING FOR SLOWLY
RISING H5 HGT/WEAKENING LLVL CYC FLOW. ALTHOUGH SOME GENERAL LARGER
SCALE SUBSIDENCE IS FCST TO DOMINATE...H85 TEMPS REMAINING AS LO AS
ABOUT -13C IN THE PRESENCE OF SOME LINGERNING DEEP MSTR/NOCTURNAL
COOLING WL BE SUFFICIENT TO MAINTAIN LES IN THE FAVORED NW WIND SN
BELTS OVER THE ERN CWA. EXPECT UP TO A COUPLE INCHES OF SN ACCUM IN
THIS AREA. OVER THE W...WARMING H85 TEMPS TO ARND -10C/ LOWERING
SUBSIDENCE INVRN UNDER THE GREATER HGT RISES SHOULD TEND TO CAUSE
THE SN SHOWERS TO DIMINISH IN THAT AREA. HOWEVER...THE PERSISTENT
UPSLOPE NW FLOW AND LINGERING UPSLOPE FLOW WL ALLOW FOR AT LEAST
SOME SCT SN SHOWERS EVEN IN THAT AREA.
THU...PERSISTENT HGT RISES AND SUBSIDENCE/TENDENCY FOR THE LLVL FLOW
TO BECOME MORE ACYC AS WELL AS SOME LLVL DRYING IN THE PRESENCE OF
DAYTIME HEATING WL DIMINISH THE SN SHOWERS W-E. FCST SDNGS INDICATE
THERE WL BE SOME SUNSHINE IN THE AFTN AS WELL WITH HI PRES RDG FCST
TO BLD INTO THE WRN CWA LATER IN THE DAY. TEMPS SHOULD REBOUND INTO
THE 40S OVER THE INTERIOR W AND SCENTRAL AWAY FM LK MODERATION WITH
H85 TEMPS PROGGED TO REACH NEAR -6C ALONG THE WI BORDER BY 00Z FRI.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 302 AM EDT WED APR 22 2015
NAM SHOWS A TROUGH OVER THE EASTERN U.S. 12Z THU WITH MORE TROUGHING
ACROSS THE WEST COAST AND A SHORTWAVE RIDGE OVER THE PLAINS. NAM
SHOWS SOME WEAK 850-500 MB Q-VECTOR CONVERGENCE MOVING THROUGH THE
CWA ON THU WITH MOISTURE MOVING OUT IN THE AFTERNOON. AS THE
SHORTWAVE RIDGE MOVES TOWARDS THE AREA AND A TROUGH OVER THE EASTERN
U.S. MOVES AWAY...THE WRAPAROUND LAKE ENHANCED PCPN WILL SLOWLY WIND
DOWN AND HAVE IT DRYING OUT FRI AND FRI NIGHT WITH SLOWLY
DIMINISHING POPS IN THE CENTRAL AND EAST ON THU INTO THU NIGHT.
OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES OR POPS.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB LOW OVER THE CENTRAL
PLAINS 12Z SAT WITH MORE TROUGHING IN THE WESTERN U.S. THE 500 MB
LOW AND TROUGH IN THE CENTRAL PLAINS GETS SHEARED OUT BY 12Z SUN AND
IS REPLACED BY A SHORTWAVE RIDGE THAT MOVES INTO THE UPPER GREAT
LAKES. THE RIDGE REMAINS OVER THE UPPER GREAT LAKES ON MON WITH
TROUGHING MOVING INTO THE NORTHERN PLAINS. THIS TROUGHING MOVES INTO
THE UPPER GREAT LAKES 12Z TUE. TEMPERATURES WILL STAY BELOW NORMAL
THIS FORECAST PERIOD. WILL CONTINUE WITH DRY WEATHER SAT THROUGH SUN
NIGHT AND THEN GO WITH SLIGHT CHANCE POPS MON THROUGH TUE AS A SFC
FRONT IS WELL OFF TO THE WEST AT THAT TIME AND PRODUCES SOME OVER
RUNNING PCPN THAT IS OFF TO THE WEST MOSTLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 349 PM EDT WED APR 22 2015
EXPECT PREDOMINANT MVFR CONDITIONS WITH CHILLY...MOIST NW FLOW OF
AIR ARND DEEP LO PRES IN SE CANADA THRU TNGT. UNDER THE HEAVIER
SHSN... CONDITIONS THRU THIS AFTN WL BE REDUCED INTO THE IFR RANGE.
THERE WL BE IMPROVEMENT TO VFR CONDITIONS ON THU WITH THE CLOSER
APRCH OF SFC HI PRES AND DRIER AIR UNDER LARGE SCALE SUBSIDENCE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 511 AM EDT WED APR 22 2015
A FEW NW WINDS GUSTING TO 30 TO NEAR 35KT GALES WILL REMAIN POSSIBLE
OVER N AND CENTRAL LAKE SUPERIOR TODAY. LOW PRESSURE ACROSS JAMES
BAY WILL FILL LATE TONIGHT AND THURSDAY. THE TROUGH ACROSS LAKE
SUPERIOR THIS MORNING...EXTENDING FROM THE JAMES BAY LOW...WILL
SLOWLY BE REPLACED BY A RIDGE. THIS RIDGE WILL REMAIN IN PLACE FROM
FRIDAY THROUGH SUNDAY...EXTENDING FROM STRONG HIGH OVER FAR NORTHERN
CANADA AND GREENLAND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...07
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
345 PM EDT WED APR 22 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 344 PM EDT WED APR 22 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO/
POCKET OF H5 TEMPS NEAR -30C CENTERED OVER ONTARIO TO THE SW OF
JAMES BAY DOWNSTREAM OF HI AMPLITUDE RDG OVER THE ROCKIES. DEEP
MOIST CYC NW FLOW ARND THE CLOSED LO CONTINUES TO IMPACT UPR MI...
DRAWING UNSEASONABLY CHILLY AIR /H85 TEMPS AS LO AS -12 TO -14C THAT
ARE SUFFICIENTLY COLD FOR LES/ INTO THE AREA. THE RESULT HAS BEEN
NMRS SN SHOWERS THAT HAVE BEEN EXACERBATED OVER LAND WITH DAYTIME
HEATING EVEN IN THE ABSENCE OF SGNFT LARGER SCALE FORCING/DEEP LYR
QVECTOR CNVGC.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMOUNTS
ESPECIALLY TNGT AS UPR LO DRIFTS SLOWLY TO THE E. TEMPS WL REMAIN
BLO NORMAL THRU THU.
TNGT...UPR LO IS FCST TO DRIFT SLOWLY TO THE E...ALLOWING FOR SLOWLY
RISING H5 HGT/WEAKENING LLVL CYC FLOW. ALTHOUGH SOME GENERAL LARGER
SCALE SUBSIDENCE IS FCST TO DOMINATE...H85 TEMPS REMAINING AS LO AS
ABOUT -13C IN THE PRESENCE OF SOME LINGERNING DEEP MSTR/NOCTURNAL
COOLING WL BE SUFFICIENT TO MAINTAIN LES IN THE FAVORED NW WIND SN
BELTS OVER THE ERN CWA. EXPECT UP TO A COUPLE INCHES OF SN ACCUM IN
THIS AREA. OVER THE W...WARMING H85 TEMPS TO ARND -10C/ LOWERING
SUBSIDENCE INVRN UNDER THE GREATER HGT RISES SHOULD TEND TO CAUSE
THE SN SHOWERS TO DIMINISH IN THAT AREA. HOWEVER...THE PERSISTENT
UPSLOPE NW FLOW AND LINGERING UPSLOPE FLOW WL ALLOW FOR AT LEAST
SOME SCT SN SHOWERS EVEN IN THAT AREA.
THU...PERSISTENT HGT RISES AND SUBSIDENCE/TENDENCY FOR THE LLVL FLOW
TO BECOME MORE ACYC AS WELL AS SOME LLVL DRYING IN THE PRESENCE OF
DAYTIME HEATING WL DIMINISH THE SN SHOWERS W-E. FCST SDNGS INDICATE
THERE WL BE SOME SUNSHINE IN THE AFTN AS WELL WITH HI PRES RDG FCST
TO BLD INTO THE WRN CWA LATER IN THE DAY. TEMPS SHOULD REBOUND INTO
THE 40S OVER THE INTERIOR W AND SCENTRAL AWAY FM LK MODERATION WITH
H85 TEMPS PROGGED TO REACH NEAR -6C ALONG THE WI BORDER BY 00Z FRI.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 302 AM EDT WED APR 22 2015
NAM SHOWS A TROUGH OVER THE EASTERN U.S. 12Z THU WITH MORE TROUGHING
ACROSS THE WEST COAST AND A SHORTWAVE RIDGE OVER THE PLAINS. NAM
SHOWS SOME WEAK 850-500 MB Q-VECTOR CONVERGENCE MOVING THROUGH THE
CWA ON THU WITH MOISTURE MOVING OUT IN THE AFTERNOON. AS THE
SHORTWAVE RIDGE MOVES TOWARDS THE AREA AND A TROUGH OVER THE EASTERN
U.S. MOVES AWAY...THE WRAPAROUND LAKE ENHANCED PCPN WILL SLOWLY WIND
DOWN AND HAVE IT DRYING OUT FRI AND FRI NIGHT WITH SLOWLY
DIMINISHING POPS IN THE CENTRAL AND EAST ON THU INTO THU NIGHT.
OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES OR POPS.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB LOW OVER THE CENTRAL
PLAINS 12Z SAT WITH MORE TROUGHING IN THE WESTERN U.S. THE 500 MB
LOW AND TROUGH IN THE CENTRAL PLAINS GETS SHEARED OUT BY 12Z SUN AND
IS REPLACED BY A SHORTWAVE RIDGE THAT MOVES INTO THE UPPER GREAT
LAKES. THE RIDGE REMAINS OVER THE UPPER GREAT LAKES ON MON WITH
TROUGHING MOVING INTO THE NORTHERN PLAINS. THIS TROUGHING MOVES INTO
THE UPPER GREAT LAKES 12Z TUE. TEMPERATURES WILL STAY BELOW NORMAL
THIS FORECAST PERIOD. WILL CONTINUE WITH DRY WEATHER SAT THROUGH SUN
NIGHT AND THEN GO WITH SLIGHT CHANCE POPS MON THROUGH TUE AS A SFC
FRONT IS WELL OFF TO THE WEST AT THAT TIME AND PRODUCES SOME OVER
RUNNING PCPN THAT IS OFF TO THE WEST MOSTLY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 729 AM EDT WED APR 22 2015
SPOTTY SNOW SHOWERS IN PERSISTENT NW FLOW HAS RESULTED IN VARIABLE
CONDITIONS RANGING MAINLY FROM MVFR TO IFR...WITH THE TEMPORARY VFR
CEILINGS AND VIS IN BETWEEN SNOW SHOWERS. DUE TO THE HIGHLY VARIABLE
REGIME...TEMPO GROUPS WILL REMAIN NECESSARY. EXPECT IMPROVING
CONDITIONS DURING THE DAYTIME HOURS WITH THE ASSISTANCE OF THE LATE
APRIL SUN...WITH CEILINGS IMPROVING A CATEGORY /MAINLY TO MVFR...IF
NOT VFR AT SAW IN THE LESS FAVORABLE NW FLOW/. THE SFC LOW OVER
JAMES BAY THIS MORNING WILL SLOWLY WEAKEN...AND A STRONG RIDGE OF
HIGH PRESSURE ACROSS N AND CENTRAL CANADA WILL BE BUILDING A RIDGE
CLOSER TO THE AREA. LOOK FOR IMPROVING CONDITIONS W TO E LATER
TONIGHT AS DRIER AIR NEARS. MVFR TO VFR CEILINGS/VIS ARE ANTICIPATED
AT IWD AROUND 12Z.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 511 AM EDT WED APR 22 2015
A FEW NW WINDS GUSTING TO 30 TO NEAR 35KT GALES WILL REMAIN POSSIBLE
OVER N AND CENTRAL LAKE SUPERIOR TODAY. LOW PRESSURE ACROSS JAMES
BAY WILL FILL LATE TONIGHT AND THURSDAY. THE TROUGH ACROSS LAKE
SUPERIOR THIS MORNING...EXTENDING FROM THE JAMES BAY LOW...WILL
SLOWLY BE REPLACED BY A RIDGE. THIS RIDGE WILL REMAIN IN PLACE FROM
FRIDAY THROUGH SUNDAY...EXTENDING FROM STRONG HIGH OVER FAR NORTHERN
CANADA AND GREENLAND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...07
AVIATION...KF
MARINE...KF
AREA FORECAST DISCUSSION
NWS BILLINGS MT
325 PM MDT WED APR 22 2015
.SHORT TERM...VALID FOR THU AND FRI...
A DEEP UPPER TROUGH WILL WORK ACROSS SOUTHERN CANADA TONIGHT. THE
SOUTHERN EXTENT OF THE WAVE WILL SWING ACROSS THE FORECAST AREA. A
FLATTENING UPPER RIDGE WILL MOVE EAST AND DEFLECT MOST OF THE
ENERGY OVER NORTHERN MONTANA. HRRR WAS PUSHING SHOWERS WITH
EMBEDDED THUNDERSTORMS ACROSS THE WEST INTO CENTRAL ZONES. HAVE
PUSHED LOW POPS INTO BILLINGS THIS EVENING BASED ON THE HRRR
SOLUTION AND RADAR RETURNS DEVELOPING OVER THE WEST.
WILL KEEP SCATTERED POPS IN THE ZONES THURSDAY AND FRIDAY. THE
STRONGEST ENERGY WILL MOVE INTO THE WEST FRIDAY AFTERNOON AND
EVENING. LOW LEVEL EASTERLY WINDS WILL BE ABLE TO PREVENT THE
DEWPOINTS FROM DRYING OUT. MODEL PROGGED PWATS WERE AROUND 2
STANDARD DEVIATIONS ABOVE NORMAL...ESPECIALLY OVER THE EAST.
INSTABILITY WAS NOT EXPECTED TO BE TREMENDOUS...BUT ENOUGH TO
WARRANT ISOLATED THUNDER MENTION. WEAK MID LEVEL FLOW ON THURSDAY
WILL CAUSE PULSING...SHORT LIVED CELLS. CELLS WILL HAVE BETTER
MOVEMENT AND MORE ORGANIZATION ON FRIDAY. TEMPERATURES WILL BE IN
THE MID 60S TO RIGHT AROUND 70 BOTH THURSDAY AND FRIDAY. TWH
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
PATTERN CONTINUES TO LOOK UNSETTLED GOING INTO EARLY NEXT WEEK.
NEGATIVELY TILTED SHORTWAVE EMBEDDED IN SOUTHWEST FLOW ALOFT WILL
BRING A CHANCE FOR SHOWERS AND A FEW THUNDERSTORMS ON SATURDAY.
STRONGER UPPER LOW DEVELOPS OVER IDAHO AND SLIDES SOUTHEAST TOWARD
COLORADO SATURDAY NIGHT AND SUNDAY WITH 700MB LOW DEVELOPING OVER
NORTHERN WYOMING. THIS IS A GOOD PRECIPITATION PATTERN FOR THE
AREA LATE SATURDAY NIGHT THROUGH SUNDAY NIGHT. INCREASED
PRECIPITATION CHANCES TO LIKELY IN MOST LOCATIONS BY EARLY SUNDAY
MORNING...TAPERING OFF FROM NORTHWEST TO SOUTHEAST SUNDAY NIGHT
INTO MONDAY. MODELS INDICATING MANY AREAS COULD SEE HALF AN INCH
OF PRECIPITATION WITH THIS SYSTEM...WITH LOCALLY HEAVIER AMOUNTS
POSSIBLE. THIS IS A PRETTY WARM PACIFIC SYSTEM AND DYNAMIC
COOLING IS HAMPERED BY STRONGEST JET FORCING STAYING SOUTH OF THE
AREA...SO KEPT PRECIPITATION TYPE MAINLY RAIN BELOW 6000 FEET.
MODELS ALL GRABBING ONTO SOME SORT OF RIDGING TUESDAY INTO
THURSDAY NEXT WEEK FOR WARMER AND DRIER CONDITIONS. CHAMBERS
&&
.AVIATION...
LIGHT EASTERLY WINDS WILL INCREASE SLIGHTLY THIS EVENING AHEAD OF
A DISTURBANCE CROSSING THE REGION EARLY THURSDAY. WINDS WILL SHIFT
WEST TO NORTHWESTERLY AND BECOME MORE GUSTY WITH FROPA. SHOWERS
ARE DEVELOPING OVER THE MOUNTAINS INTO TONIGHT...SOME WILL REACH
NEARBY PLAINS...WITH LOCALIZED MVFR POSSIBLE. THE WAVE CROSSING
THE REGION THURSDAY WILL BRING ANOTHER SLIGHT CHANCE FOR SHOWERS
ACROSS THE REGION. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 046/067 044/068 044/059 039/055 038/066 042/072 044/072
22/T 23/T 43/T 66/R 42/W 11/B 10/B
LVM 039/067 038/066 038/055 035/053 031/065 037/072 040/070
34/T 34/T 54/T 66/R 42/W 11/B 10/B
HDN 040/069 039/071 039/061 039/054 038/066 037/073 043/072
02/T 22/T 33/T 56/R 42/W 11/B 10/B
MLS 038/069 038/070 040/060 039/055 039/066 037/070 042/069
02/T 11/B 35/T 56/R 52/W 11/B 11/B
4BQ 037/071 038/070 041/061 040/055 039/065 039/069 041/068
02/T 22/T 25/T 57/R 63/W 11/B 11/U
BHK 032/065 034/064 036/058 040/053 039/062 038/066 041/064
02/T 11/B 25/T 56/R 63/W 11/B 11/B
SHR 039/067 039/067 039/056 037/050 036/063 037/069 039/066
02/T 22/T 22/T 47/R 52/W 11/B 10/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1227 PM CDT WED APR 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM CDT WED APR 22 2015
ELONGATED HIGH PRESSURE FROM CANADA TO THE
MISSOURI BASIN DRIFTS EAST TODAY SETTING UP A COOL SOUTHERLY RETURN
FLOW FROM KANSAS. THE RAP MODEL INDICATES A WARM FRONT WILL DEVELOP
ACROSS WRN NEB WHICH MOVES EAST THIS AFTERNOON AND TONIGHT. THE
MODEL SUGGESTS A NARROW MIDLEVEL CLOUD SHIELD WILL DEVELOP NEAR
VALENTINE TONIGHT WHICH IS WELL SUPPORTED BY THE GFS...LESS SO BY
THE OTHER MODELS. THE OBVIOUS CULPRIT IS 700MB FRONTOGENESIS AND THE
DEVELOPING WARM FRONT. THE FORECAST IS FOR PARTLY CLOUDY SKIES TODAY
AND TONIGHT WITH TEMPERATURES RISING INTO THE 50S AND 60S. LOWS
TONIGHT FALL INTO THE 30S TO NEAR FREEZING EAST OF HIGHWAY 83.
MOISTURE WILL RETURN LATE TONIGHT ACROSS SWRN NEB. THE MODEL
SOUNDINGS SUGGESTS A SUNRISE SURPRISE THURSDAY MORNING WITH STRATUS
DEVELOPING WITH THE ONSET OF MIXING AFTER SUNRISE. A SLIGHT DELAY
OF 3 HOURS IN THE MOISTURE RETURN WOULD RESULT IN SUFFICIENT
HEATING AND MIXING TO PRECLUDE CLOUD DEVELOPMENT. MEANWHILE...IF
THE MODELS ARE TOO SLOW THEN CLOUDS COULD FORM BEFORE SUNRISE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 348 AM CDT WED APR 22 2015
LONG WAVE TROUGH WILL BE MOVING ONSHORE THE WEST COAST
THURSDAY...WITH FLOW ALOFT BECOMING SOUTHWEST AHEAD OF THE TROUGH
ACROSS THE CENTRAL PLAINS. ONE DISTURBANCE WILL EJECT NORTHEAST FROM
THE TROUGH THURSDAY NIGHT INTO FRIDAY. MODELS ARE WEAKER WITH THIS
FEATURE COMPARED TO A COUPLE OF DAYS AGO...AND HAVE PUT THE BREAKS
ON THE POPS. WILL LEAVE IN THE CHANCE CATEGORY FOR THE MOST PART.
LIFT IS MARGINAL AND NOT ORGANIZED IN ANY ONE AREA...SO THINKING A
MORE SHOWERY TYPE RAIN WILL OCCUR. ACTUALLY KIND OF HARD TO PIN DOWN
EXACTLY WHERE...BUT THE BETTER CHANCE WOULD LIKELY BE AFTER MIDNIGHT
THURSDAY NIGHT INTO FRIDAY MORNING ON THE NOSE OF A SOUTHERLY LOW
LEVEL JET ACROSS CENTRAL INTO EASTERN NEBRASKA. THEN LATER IN THE
DAY ACROSS THE WESTERN HIGH PLAINS OF NEBRASKA INTO EASTERN
COLORADO...AS CONDITIONS BECOME SOMEWHAT UNSTABLE LEADING TO A
SCATTERING OF THUNDERSTORMS. THESE STORMS WILL BE AIDED BY THE
ACTUAL DISTURBANCE CROSSING THE AREA DURING PEAK HEATING. THESE
STORMS WILL WEAKEN SOMEWHAT AS THEY MOVE EAST...BUT DO EXPECT AT
LEAST SHOWERS TO MOVE ACROSS THE AREA FRIDAY NIGHT. AGAIN...DOESN/T
APPEAR TO BE REAL ORGANIZED...AND CAN/T JUSTIFY LIKELY POPS AT ANY
ONE LOCATION AT THIS TIME.
FOR THE WEEKEND INTO EARLY NEXT WEEK...IT LOOKS RATHER INTERESTING.
THE LONG WAVE TROUGH MOVES INTO THE ROCKIES BY SUNDAY. SATURDAY
LOOKING TO BE A FAIRLY DRY DAY AS RIDGING DEVELOPS ACROSS THE
CENTRAL PLAINS AHEAD OF THE TROUGH. TRIED TO LIMIT POPS TO JUST A
SLIGHT CHANCE FOR THIS REASON SATURDAY. BY SUNDAY NIGHT INTO
MONDAY...THE MODELS DIG THE TROUGH INTO THE FOUR CORNERS WHERE IT
SHOULD CLOSE OFF. VERY GOOD AGREEMENT AMONG THE GFS ENSEMBLE
MEMBERS ON THIS OCCURRING...AND BOTH THE OPERATIONAL GFS AND ECMWF
INDICATE THIS SCENARIO AS WELL. HOWEVER...THE ECMWF CONTINUES TO
DIG THE SYSTEM SOUTH INTO TEXAS LEAVING US WITH LITTLE
PRECIPITATION. THE GFS AND GFS ENSEMBLE MEAN ON THE OTHER HAND ARE
FARTHER NORTH...AND HAVE A CLOSED H700MB LOW CENTER IN SOUTHEAST
COLORADO SUNDAY NIGHT. ALSO THEY HAVE HEAVY RAINFALL SUNDAY NIGHT
INTO MONDAY FROM NORTHWEST KANSAS...NORTH AND WEST ACROSS
NORTHEAST COLORADO...SOUTHWEST NEBRASKA AND THE SOUTHERN NEBRASKA
PANHANDLE. OVERALL THIS STRONG CLOSED SYSTEM IS A NEW DEVELOPMENT
IN THE MODELS/ENSEMBLE TONIGHT...AND WON/T GET CARRIED AWAY WITH
RAIN CHANCES JUST YET. ALSO TONIGHT/S SOLUTIONS ARE A BIT
SLOWER...SO THE HIGHER CHANCES FOR RAIN CURRENTLY IN THE FORECAST
FOR SUNDAY MAY HAVE TO BE EXTENDED INTO SUNDAY NIGHT AND MONDAY.
WILL CONTINUE TO MONITOR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1221 PM CDT WED APR 22 2015
VFR CONDITIONS ARE FORECAST FOR MOST OF WESTERN AND NORTH CENTRAL
NEBRASKA THROUGH THE NEXT 24 HOURS. PRIMARY FORECAST CONCERN IS
THE CHANCE FOR LOW CIGS IN SOUTHWEST NEBRASKA THURSDAY MORNING.
MODEL GUIDANCE REMAINS INCONSISTENT WITH THE HANDLING OF
POTENTIAL CLOUD COVER TOMORROW MORNING...HOWEVER AT THIS TIME THE
BEST CHANCE FOR MVFR OR LOWER CIGS LOOKS TO BE JUST WEST AND
SOUTH OF KLBF.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
400 PM EDT WED APR 22 2015
.SYNOPSIS...
A LARGE UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE FROM NORTH OF
THE GREAT LAKES EASTWARD ACROSS ONTARIO AND QUEBEC THIS WEEK. THIS
FEATURE WILL KEEP NORTHERN NEW YORK AND VERMONT TRAPPED IN AN
OVERCAST SHOWERY PERIOD. SOME SNOW SHOWERS ARE POSSIBLE ACROSS THE
HIGHER TERRAIN...WITH SOME ACCUMULATING SNOW FOR THE SUMMITS.
&&
.NEAR TERM /UNTIL 8 AM THURSDAY MORNING/...
AS OF 345 PM EDT WEDNESDAY...NORTH COUNTRY WILL REMAIN IN DEEP-
LAYER SOUTHWESTERLY FLOW THIS EVENING AS CLOSED UPPER LOW BEGINS
TO SLOWLY DRIFT EASTWARD. SHORTWAVE CURRENTLY LIFTING
NORTHEASTWARD ACROSS OUR VERMONT ZONES...THIS WILL ENHANCE UPWARD
MOTION AND EXPAND COVERAGE OF SHOWER ACTIVITY THIS EVENING. EXPECT
WIDESPREAD RAIN ACROSS OUR VERMONT ZONES AND HAVE CATEGORICAL POPS
FOR THIS REASON. LINGERING RAIN SHOWERS THIS EVENING WILL
GRADUALLY MOVE NEWD OUT OF THE REGION OVERNIGHT...ENDING BY
MIDNIGHT. WHILE SKIES WILL REMAIN MOSTLY CLOUDY OVERNIGHT...LOW-
LEVEL CAA FROM THE WEST WILL ALLOW TEMPS TO FALL INTO THE LOW-MID
30S.
&&
.SHORT TERM /8 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 345 PM EDT WEDNESDAY...SEASONABLY COOL AND MOIST
CONDITIONS...WITH POTENTIAL FOR UPSLOPE/OROGRAPHIC SNOWFALL
THURSDAY NIGHT INTO FRIDAY...INCLUDING LIGHT TO MODERATE
ACCUMULATIONS FOR THE HIGHER SUMMITS.
DURING THE DAYTIME HOURS ON THURSDAY UPPER LEVEL LOW WILL BE ITS
CLOSEST IN PROXIMITY TO OUR FORECAST AREA. CLOUDY SKIES...COOL
TEMPERATURES AND MOIST CONDITIONS WILL CONTINUE. COOLER THAN
NORMAL TEMPERATURES CAN BE EXPECTED. POTENTIAL FOR SHOWERS
INCREASES WITH NORTHWESTERLY FLOW DEVELOPING IN THE AFTERNOON AND
OVERNIGHT. PRETTY GOOD UPSLOPE SNOW SET UP FOR THURSDAY NIGHT AND
COLD ENOUGH ABOVE 1000 FEET FOR SNOW...RAIN SNOW MIX IN THE VALLEY
LOCATIONS. BELOW NORMAL MINIMUM TEMPERATURES ARE EXPECTED WITH
MOST OF THE AREA BOTTOMING OUT AROUND FREEZING. REGION REMAINS
STUCK UNDER INFLUENCE OF UPPER LEVEL LOW ALL THE WAY THROUGH
FRIDAY NIGHT...LOW WILL BE REACHING THE GULF OF MAINE BY FRIDAY
NIGHT. GENERALLY ISOLATED VALLEY SHOWERS AND MORE FREQUENT RAIN
AND SNOW SHOWERS ACROSS THE HIGHER ELEVATIONS ON FRIDAY AND FRIDAY
NIGHT. BELOW NORMAL TEMPERATURES CONTINUE THROUGH THIS PERIOD.
COULD SEE SOME DECENT SNOW ACCUMULATIONS IN THE HIGHER ELEVATIONS
FOR LATE MAY THIS WEEK...BEST CHANCE FOR ACCUMULATIONS BEING
THURSDAY NIGHT INTO FRIDAY MORNING WITH THE STRONGEST
NORTHWESTERLY FLOW DURING THAT TIME AND OROGRAPHIC UPSLOPE EFFECTS
HELPING US OUT. AROUND 6 INCHES OF SNOW ALONG THE RIDGE TOPS FROM
JAY PEAK TO MOUNT MANSFIELD...AND SIMILARLY ACROSS THE HIGHEST
PEAKS OF THE ADIRONDACKS. A COATING TO 1 ONE AMOUNTS DOWN TO ABOUT
1000 FEET WITH NO SIGNIFICANT ACCUMULATIONS BELOW THAT. DURING THE
DAYTIME HOURS ON FRIDAY THE SNOW LEVEL SHOULD LIFT TO 2000 FEET OR
HIGHER.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 326 PM EDT WEDNESDAY...THE BEGINNING OF THE WEEKEND WILL
CONTINUE THE THEME OF PERIODIC APRIL SHOWERS WITH MOSTLY CLOUDY
SKIES UNDER PERSISTENT NORTHWEST UPSLOPE FLOW WITH A CLOSED UPPER
LEVEL LOW TO THE NORTHEAST.
BOTH THE GFS AND ECMWF MODEL INDICATE THE UPPER LEVEL LOW WILL BE
CENTERED JUST OFF THE COAST OF MAINE SATURDAY WITH A SURFACE LOW
PRESSURE SYSTEM LOCATED WELL OFFSHORE SOUTHWEST OF NOVA SCOTIA.
THE PERSISTENT NORTHWEST FLOW WILL GENERATE SOME OFF AND ON
UPSLOPE RAIN/SNOW SHOWERS WITH THE SNOW SHOWERS ONLY REALLY BEING
POSSIBLE IN THE HIGHER SUMMITS DURING THE DAYTIMES WITH A MIX OF
RAIN AND SNOW IN THE VALLEYS POSSIBLE IN THE OVERNIGHT HOURS.
BEGINNING NEXT WEEK THE UPPER LEVEL LOW CONTINUES TO STAY IN A
SEMI PERMANENT LOCATION CENTERED OVER NEW ENGLAND AND THEN A
SURFACE LOW PRESSURE SYSTEM WILL SLIDE OFFSHORE JUST SOUTH OF
VIRGINIA AND PHASE WITH THE RETROGRADING LOW FROM THE CANADIAN
MARITIMES. HOWEVER THE STRENGTH AND INTENSITY OF THAT LOW IS
SIGNIFICANTLY BETWEEN THE GFS AND ECMWF. THE ECMWF REMAINS THE
SLOWER MOVING MODEL FROM THE REST OF THE MODEL SUITE BEING FAR
MORE PROGRESSIVE AND ENDS UP DEVELOPING A 962MB LOW OFFSHORE.
GIVEN THE NATURE OF THE SINGLE OUTLIER I STAYED AWAY FROM THAT
SOLUTION AND RELIED MORE ON A BLEND OF THE CANADIAN AND GFS.
REGARDING TEMPERATURES, DAYTIME MAX TEMPS WILL SEE A SLIGHT
WARMING TREND THROUGH THE WEEKEND INTO NEXT WEEK. EXPECT MAX TEMPS
WILL START IN THE UPPER 40S TO MID 50S ON SUNDAY WARMING TO MID
50S TO LOW 60S BY WEDNESDAY NEXT WEEK. OVERNIGHT LOWS WILL BE
PRETTY CONSISTENTLY IN THE UPPER 20S IN THE HIGHER TERRAIN ABOVE
2000 FEET TO THE MID TO UPPER 30S IN THE SAINT LAWRENCE AND
CHAMPLAIN VALLEYS.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...PERIODS OF MVFR CEILINGS AND VISIBILITIES
DEVELOPING AS RAIN SHOWERS MOVE INTO THE REGION, AND EVEN SOME WET
SNOW FLAKES MIXED IN AT SLK OVERNIGHT AS TEMPS DROP IN THE
BOUNDARY LAYER. SOME OF THE HIRES WINDOWS ARE SHOWING THAT THE
RAIN COULD BE HEAVY AT TIMES IN RUT/MPV HOWEVER GIVEN THE
UNCERTAINTY IN HOW HEAVY THE RAIN WILL FAIL I`VE CONTINUED TO
LEAVE IT OUT OF THE TAFS FOR NOW AND WILL MONITOR/UPDATE AS
NECESSARY.
SCATTERED TO BROKEN VFR CLOUDS AND SCATTERED RAIN SHOWERS WILL
PERSIST ACROSS THE REGION THROUGH TODAY. A WAVE OF LOW PRESSURE
WILL BRING A MORE ORGANIZED PERIOD OF LIGHT RAIN IN THE AFTERNOON
AND EVENING AS DEPICTED IN THE LATEST HRRR WHICH HAS A HANDLE ON
SHOWERS NOW ENTERING THE ST. LAWRENCE VALLEY. THE HRRR SEEMS A BIT
ON THE FASTER SIDE TO MOVE THE SHOWERS OUT SO I INITIALIZED THE
FORECAST WITH THE HRRR BUT THEN TRENDED MORE TOWARDS AN ENSEMBLE
OF THE LOCAL WRF`S FOR THE EVENING WITH REGARDS TO WX/VSBY. WINDS
SOUTH/SOUTHWEST LESS THAN 7 KNOTS BECOMING 10 KNOTS WITH GUSTS
15-20 KNOTS DURING THE DAY TODAY.
OUTLOOK 18Z THURSDAY THROUGH SUNDAY... 18Z THURS - 00Z SAT: VFR
WITH PERSISTENT MOSTLY CLOUDY CONDITIONS AND SOME POSSIBLE MVFR
WITH OFF AND ON LIGHT RAIN. COULD BE A SLIGHT MIX OF RAIN/SNOW
LATE THURS EVENING.
00Z SAT - SUNDAY: VFR WITH PERIODS OF MVFR AS RAIN SHOWERS MOVE
THROUGH THE AREA.
&&
.HYDROLOGY...
FLOOD WARNING CONTINUES FOR THE BARTON RIVER NEAR COVENTRY. MAY
SEE SOME RISES ON OTHER SMALLER RIVERS IN THE REGION WITH
WIDESPREAD RAINFALL ACROSS THE AREA. AT THIS POINT DOES NOT LOOK
LIKE WE WILL NEED ANY FURTHER WARNINGS AT THIS TIME.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...NEILES
SHORT TERM...NEILES
LONG TERM...DEAL
AVIATION...DEAL
HYDROLOGY...NEILES
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
327 PM EDT WED APR 22 2015
.SYNOPSIS...
A LARGE UPPER LEVEL LOW PRESSURE SYSTEM ACROSS THE GREAT LAKES
AND ONTARIO WILL DRIFT SLOWLY EASTWARD THROUGH THE END OF THE
WEEK. THIS SYSTEM WILL PROVIDE THE NORTH COUNTRY WITH SEASONABLY
COOL CONDITIONS...ALONG WITH CONSIDERABLE CLOUDINESS. EMBEDDED
SMALLER SCALE DISTURBANCES WILL BRING PERIODS OF RAIN
SHOWERS...WHICH WILL BE MOST WIDESPREAD LATE TODAY INTO TONIGHT.
SOME SNOW SHOWERS ARE POSSIBLE ACROSS THE HIGHER TERRAIN...WITH
SOME ACCUMULATING SNOW FOR THE SUMMITS ESPECIALLY THURSDAY NIGHT
INTO FRIDAY.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 120 PM EDT WEDNESDAY...GOING FORECAST IS IN REALLY GOOD
SHAPE. AREA OF SHOWERS LIFTING NORTH INTO OUR FORECAST AREA
CURRENTLY. ADJUSTED FORECAST TO REFLECT CURRENT OBSERVATIONS.
PREVIOUS DISCUSSION FOLLOWS.
NORTH COUNTRY WILL REMAIN IN DEEP-LAYER SWLY FLOW TODAY...AS
CLOSED UPPER LOW REMAINS QUASI- STATIONARY NORTH OF THE U.P. OF
MICHIGAN. SHORTWAVE TROUGH ROUNDING THE BASE OF THE 500MB TROUGH
WILL SHIFT NEWD FROM PA ACROSS NY/NEW ENGLAND DURING THE AFTN HRS.
THIS WILL ENHANCE UPWARD MOTION AND EXPAND COVERAGE OF SHOWER
ACTIVITY THIS AFTERNOON AND EVENING. ALL GUIDANCE CONSISTENT IN
SHOWING SHOWER ACTIVITY MOST WIDESPREAD ACROSS CENTRAL/ERN
VT...AND HAVE SHOWN HIGHEST POPS THERE (80-100 PERCENT)...AND
GENERALLY 50-80 PERCENT ACROSS THE CHAMPLAIN VALLEY WWD INTO THE
ADIRONDACKS.
BASED ON EARLY AM RADAR TRENDS...IT APPEARS ISOLD/SCT SHOWERS
WILL MOVE ACROSS NRN NY - AND PERHAPS INTO THE CHAMPLAIN VALLEY -
DURING THE MID MORNING HRS. SHOWERS MOVING GENERALLY NE 30-35 MPH
EAST OF LAKE ONTARIO AS OF 1120Z. HAVE CARRIED CHANCE POPS DURING
THE MORNING HRS TO COVER THIS SHOWER ACTIVITY AS IT MOVES NEWD.
OVERALL TREND WILL BE FOR ACTIVITY TO BECOME MORE WIDESPREAD AS
THE AFTERNOON PROGRESSES, ESPECIALLY FOR CENTRAL AND ERN VT. SUNNY
SKIES EXPECTED AT TIMES DURING THE MORNING HRS...BEFORE TRENDING
MOSTLY CLOUDY FOR THE AFTERNOON AND EVENING PERIOD. RAINFALL AMTS
GENERALLY A TENTH TO 0.30" FROM THE ADIRONDACKS EWD...WITH THE
HIGHEST TOTALS EXPECTED ACROSS ERN VT. MEANWHILE...RAINFALL
GENERALLY <0.10" ACROSS THE ST. LAWRENCE VALLEY. HIGH TEMPERATURES
TODAY GENERALLY EXPECTED IN THE MID-UPR 50S. SFC WINDS GENERALLY
SOUTH 10-15 MPH THIS MORNING...SHIFTING INTO THE SW AND WEST THIS
AFTN WITH TROUGH PASSAGE.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY NIGHT/...
AS OF 306 AM EDT WEDNESDAY...THE SHORT-TERM WILL FEATURE
CONTINUED SEASONABLY COOL AND MOIST CONDITIONS...WITH POTENTIAL
FOR UPSLOPE/OROGRAPHIC SNOWFALL THURSDAY NIGHT INTO
FRIDAY...INCLUDING LIGHT TO MODERATE ACCUMULATIONS FOR THE HIGHER
SUMMITS.
LINGERING RAIN SHOWERS ACROSS CENTRAL INTO NERN VT THIS EVENING
WILL GRADUALLY MOVE NEWD OUT OF THE REGION OVERNIGHT. MAY SEE AN
ADDITIONAL 0.10"-0.20" RAINFALL ACROSS CENTRAL/ERN VT BEFORE
ACTIVITY ENDS AROUND MIDNIGHT. SHOULD SEE AT LEAST SOME MODEST
RISES ON AREA RIVERS TONIGHT...AND MINOR FLOODING IS POSSIBLE FOR
THE BARTON RIVER AT COVENTRY BASED ON CURRENT EXPECTATIONS. WHILE
SKIES WILL REMAIN MOSTLY CLOUDY OVERNIGHT...LOW-LEVEL CAA FROM THE
WEST WILL ALLOW TEMPS TO FALL INTO THE LOW-MID 30S FOR OVERNIGHT
LOWS.
UPR LOW CENTER PROGRESSES ACROSS NRN NY AND VT ON
THURSDAY...MAINTAINING CLOUDY SKIES, ALONG WITH COOL AND MOIST
CONDITIONS. HIGH TEMPERATURES ON THURSDAY WILL BE WELL BELOW
SEASONABLE NORMS...AND GENERALLY IN THE MID TO UPPER 40S...AND
LOCALLY IN THE LOWER 40S FOR THE NRN ADIRONDACK REGION.
POTENTIAL FOR SHOWERS WILL GRADUALLY INCREASE AS NWLY FLOW
DEVELOPS ACROSS NRN NY THURSDAY AFTN...AND ACROSS VT THURSDAY
NIGHT. LOOKS LIKE AN UPSLOPE FLOW SETUP FOR A TIME THURSDAY
NIGHT...AND THERMAL FIELDS SUPPORT SNOW AT ELEVATIONS ABOVE
1000`...WITH A RAIN/SNOW MIX POSSIBLE IN VALLEY LOCATIONS LATER
THURSDAY NIGHT. LOWS THURSDAY NIGHT WILL BE NEAR FREEZING MOST
LOCATIONS...AND LOCALLY IN THE LOW- MID 20S ABOVE 2000 FEET
ELEVATION.
CYCLONIC FLOW REMAINS IN PLACE THROUGH FRIDAY...WITH ISOLD VALLEY
SHOWERS AND MORE FREQUENT RAIN/SNOW SHOWERS ACROSS THE HIGHER
ELEVATIONS. HIGHS FRIDAY REMAINING COOL...GENERALLY 45-50F.
MAY SEE SOME DECENT SNOWFALL ACCUMULATIONS ACROSS THE HIGHER
SUMMITS OF THE NRN ADIRONDACKS AND CENTRAL/NRN GREEN MTNS...MAINLY
THURSDAY NIGHT AND FRIDAY. CURRENT INDICATIONS SUPPORT AROUND 6"
OF NEW SNOW ALONG THE RIDGE TOPS FROM JAY PEAK TO MT.
MANSFIELD...AND SIMILARLY ACROSS THE HIGH PEAKS OF THE
ADIRONDACKS. MAY SEE A WET COATING-1" SNOWFALL AMTS DOWN TO ABOUT
1000` DURING THURSDAY NIGHT...WITH SNOW LEVELS RISING DURING THE
DAY FRIDAY TO ABOVE 2000`.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 326 PM EDT WEDNESDAY...THE BEGINNING OF THE WEEKEND WILL
CONTINUE THE THEME OF PERIODIC APRIL SHOWERS WITH MOSTLY CLOUDY
SKIES UNDER PERSISTENT NORTHWEST UPSLOPE FLOW WITH A CLOSED UPPER
LEVEL LOW TO THE NORTHEAST.
BOTH THE GFS AND ECMWF MODEL INDICATE THE UPPER LEVEL LOW WILL BE
CENTERED JUST OFF THE COAST OF MAINE SATURDAY WITH A SURFACE LOW
PRESSURE SYSTEM LOCATED WELL OFFSHORE SOUTHWEST OF NOVA SCOTIA. THE
PERSISTENT NORTHWEST FLOW WILL GENERATE SOME OFF AND ON UPSLOPE
RAIN/SNOW SHOWERS WITH THE SNOW SHOWERS ONLY REALLY BEING POSSIBLE
IN THE HIGHER SUMMITS DURING THE DAYTIMES WITH A MIX OF RAIN AND
SNOW IN THE VALLEYS POSSIBLE IN THE OVERNIGHT HOURS.
BEGINNING NEXT WEEK THE UPPER LEVEL LOW CONTINUES TO STAY IN A SEMI
PERMANENT LOCATION CENTERED OVER NEW ENGLAND AND THEN A SURFACE LOW
PRESSURE SYSTEM WILL SLIDE OFFSHORE JUST SOUTH OF VIRGINIA AND PHASE
WITH THE RETROGRADING LOW FROM THE CANADIAN MARITIMES. HOWEVER THE
STRENGTH AND INTENSITY OF THAT LOW IS SIGNIFICANTLY BETWEEN THE GFS
AND ECMWF. THE ECMWF REMAINS THE SLOWER MOVING MODEL FROM THE REST
OF THE MODEL SUITE BEING FAR MORE PROGRESSIVE AND ENDS UP DEVELOPING
A 962MB LOW OFFSHORE. GIVEN THE NATURE OF THE SINGLE OUTLIER I
STAYED AWAY FROM THAT SOLUTION AND RELIED MORE ON A BLEND OF THE
CANADIAN AND GFS.
REGARDING TEMPERATURES, DAYTIME MAX TEMPS WILL SEE A SLIGHT WARMING
TREND THROUGH THE WEEKEND INTO NEXT WEEK. EXPECT MAX TEMPS WILL
START IN THE UPPER 40S TO MID 50S ON SUNDAY WARMING TO MID 50S TO
LOW 60S BY WEDNESDAY NEXT WEEK. OVERNIGHT LOWS WILL BE PRETTY
CONSISTENTLY IN THE UPPER 20S IN THE HIGHER TERRAIN ABOVE 2000 FEET
TO THE MID TO UPPER 30S IN THE SAINT LAWRENCE AND CHAMPLAIN VALLEYS.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...PERIODS OF MVFR CEILINGS AND VISIBILITIES
DEVELOPING AS RAIN SHOWERS MOVE INTO THE REGION, AND EVEN SOME
WET SNOW FLAKES MIXED IN AT SLK OVERNIGHT AS TEMPS DROP IN THE
BOUNDARY LAYER. SOME OF THE HIRES WINDOWS ARE SHOWING THAT THE
RAIN COULD BE HEAVY AT TIMES IN RUT/MPV HOWEVER GIVEN THE
UNCERTAINTY IN HOW HEAVY THE RAIN WILL FAIL I`VE CONTINUED TO
LEAVE IT OUT OF THE TAFS FOR NOW AND WILL MONITOR/UPDATE AS
NECESSARY.
SCATTERED TO BROKEN VFR CLOUDS AND SCATTERED RAIN SHOWERS WILL
PERSIST ACROSS THE REGION THROUGH TODAY. A WAVE OF LOW PRESSURE
WILL BRING A MORE ORGANIZED PERIOD OF LIGHT RAIN IN THE AFTERNOON
AND EVENING AS DEPICTED IN THE LATEST HRRR WHICH HAS A HANDLE ON
SHOWERS NOW ENTERING THE ST. LAWRENCE VALLEY. THE HRRR SEEMS A BIT
ON THE FASTER SIDE TO MOVE THE SHOWERS OUT SO I INITIALIZED THE
FORECAST WITH THE HRRR BUT THEN TRENDED MORE TOWARDS AN ENSEMBLE
OF THE LOCAL WRF`S FOR THE EVENING WITH REGARDS TO WX/VSBY. WINDS
SOUTH/SOUTHWEST LESS THAN 7 KNOTS BECOMING 10 KNOTS WITH GUSTS
15-20 KNOTS DURING THE DAY TODAY.
OUTLOOK 18Z THURSDAY THROUGH SUNDAY...
18Z THURS - 00Z SAT: VFR WITH PERSISTENT MOSTLY CLOUDY CONDITIONS
AND SOME POSSIBLE MVFR WITH OFF AND ON LIGHT RAIN. COULD BE A
SLIGHT MIX OF RAIN/SNOW LATE THURS EVENING.
00Z SAT - SUNDAY: VFR WITH PERIODS OF MVFR AS RAIN SHOWERS MOVE
THROUGH THE AREA.
&&
.HYDROLOGY...
RAINFALL AMOUNTS OF UP TO 0.50" ARE EXPECTED ACROSS CENTRAL/ERN
VT THIS AFTERNOON THROUGH THE FIRST HALF OF TONIGHT. SOME MODEST
RIVER RISES CAN BE EXPECTED LATE TODAY THROUGH TONIGHT. SINCE THE
BARTON RIVER AT COVENTRY HAD AN OBSERVED STAGE OF 7.6` AT 07Z THIS
MORNING...ANTICIPATE THAT ONE FORECAST POINT WILL LIKELY REACH
MINOR FLOOD STAGE (BETWEEN 8-9`) SOMETIME TONIGHT.
ELSEWHERE...RIVER RISES ARE EXPECTED TO BE WITHIN BANKFULL.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS/NEILES
SHORT TERM...BANACOS
LONG TERM...DEAL
AVIATION...DEAL
HYDROLOGY...TEAM BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
151 PM EDT WED APR 22 2015
.SYNOPSIS...
A LARGE UPPER LEVEL LOW PRESSURE SYSTEM ACROSS THE GREAT LAKES
AND ONTARIO WILL DRIFT SLOWLY EASTWARD THROUGH THE END OF THE
WEEK. THIS SYSTEM WILL PROVIDE THE NORTH COUNTRY WITH SEASONABLY
COOL CONDITIONS...ALONG WITH CONSIDERABLE CLOUDINESS. EMBEDDED
SMALLER SCALE DISTURBANCES WILL BRING PERIODS OF RAIN
SHOWERS...WHICH WILL BE MOST WIDESPREAD LATE TODAY INTO TONIGHT.
SOME SNOW SHOWERS ARE POSSIBLE ACROSS THE HIGHER TERRAIN...WITH
SOME ACCUMULATING SNOW FOR THE SUMMITS ESPECIALLY THURSDAY NIGHT
INTO FRIDAY.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 120 PM EDT WEDNESDAY...GOING FORECAST IS IN REALLY GOOD
SHAPE. AREA OF SHOWERS LIFTING NORTH INTO OUR FORECAST AREA
CURRENTLY. ADJUSTED FORECAST TO REFLECT CURRENT OBSERVATIONS.
PREVIOUS DISCUSSION FOLLOWS.
NORTH COUNTRY WILL REMAIN IN DEEP-LAYER SWLY FLOW TODAY...AS
CLOSED UPPER LOW REMAINS QUASI- STATIONARY NORTH OF THE U.P. OF
MICHIGAN. SHORTWAVE TROUGH ROUNDING THE BASE OF THE 500MB TROUGH
WILL SHIFT NEWD FROM PA ACROSS NY/NEW ENGLAND DURING THE AFTN HRS.
THIS WILL ENHANCE UPWARD MOTION AND EXPAND COVERAGE OF SHOWER
ACTIVITY THIS AFTERNOON AND EVENING. ALL GUIDANCE CONSISTENT IN
SHOWING SHOWER ACTIVITY MOST WIDESPREAD ACROSS CENTRAL/ERN
VT...AND HAVE SHOWN HIGHEST POPS THERE (80-100 PERCENT)...AND
GENERALLY 50-80 PERCENT ACROSS THE CHAMPLAIN VALLEY WWD INTO THE
ADIRONDACKS.
BASED ON EARLY AM RADAR TRENDS...IT APPEARS ISOLD/SCT SHOWERS
WILL MOVE ACROSS NRN NY - AND PERHAPS INTO THE CHAMPLAIN VALLEY -
DURING THE MID MORNING HRS. SHOWERS MOVING GENERALLY NE 30-35 MPH
EAST OF LAKE ONTARIO AS OF 1120Z. HAVE CARRIED CHANCE POPS DURING
THE MORNING HRS TO COVER THIS SHOWER ACTIVITY AS IT MOVES NEWD.
OVERALL TREND WILL BE FOR ACTIVITY TO BECOME MORE WIDESPREAD AS
THE AFTERNOON PROGRESSES, ESPECIALLY FOR CENTRAL AND ERN VT. SUNNY
SKIES EXPECTED AT TIMES DURING THE MORNING HRS...BEFORE TRENDING
MOSTLY CLOUDY FOR THE AFTERNOON AND EVENING PERIOD. RAINFALL AMTS
GENERALLY A TENTH TO 0.30" FROM THE ADIRONDACKS EWD...WITH THE
HIGHEST TOTALS EXPECTED ACROSS ERN VT. MEANWHILE...RAINFALL
GENERALLY <0.10" ACROSS THE ST. LAWRENCE VALLEY. HIGH TEMPERATURES
TODAY GENERALLY EXPECTED IN THE MID-UPR 50S. SFC WINDS GENERALLY
SOUTH 10-15 MPH THIS MORNING...SHIFTING INTO THE SW AND WEST THIS
AFTN WITH TROUGH PASSAGE.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/...
AS OF 306 AM EDT WEDNESDAY...THE SHORT-TERM WILL FEATURE
CONTINUED SEASONABLY COOL AND MOIST CONDITIONS...WITH POTENTIAL
FOR UPSLOPE/OROGRAPHIC SNOWFALL THURSDAY NIGHT INTO
FRIDAY...INCLUDING LIGHT TO MODERATE ACCUMULATIONS FOR THE HIGHER
SUMMITS.
LINGERING RAIN SHOWERS ACROSS CENTRAL INTO NERN VT THIS EVENING
WILL GRADUALLY MOVE NEWD OUT OF THE REGION OVERNIGHT. MAY SEE AN
ADDITIONAL 0.10"-0.20" RAINFALL ACROSS CENTRAL/ERN VT BEFORE
ACTIVITY ENDS AROUND MIDNIGHT. SHOULD SEE AT LEAST SOME MODEST
RISES ON AREA RIVERS TONIGHT...AND MINOR FLOODING IS POSSIBLE FOR
THE BARTON RIVER AT COVENTRY BASED ON CURRENT EXPECTATIONS. WHILE
SKIES WILL REMAIN MOSTLY CLOUDY OVERNIGHT...LOW-LEVEL CAA FROM THE
WEST WILL ALLOW TEMPS TO FALL INTO THE LOW-MID 30S FOR OVERNIGHT
LOWS.
UPR LOW CENTER PROGRESSES ACROSS NRN NY AND VT ON
THURSDAY...MAINTAINING CLOUDY SKIES, ALONG WITH COOL AND MOIST
CONDITIONS. HIGH TEMPERATURES ON THURSDAY WILL BE WELL BELOW
SEASONABLE NORMS...AND GENERALLY IN THE MID TO UPPER 40S...AND
LOCALLY IN THE LOWER 40S FOR THE NRN ADIRONDACK REGION.
POTENTIAL FOR SHOWERS WILL GRADUALLY INCREASE AS NWLY FLOW
DEVELOPS ACROSS NRN NY THURSDAY AFTN...AND ACROSS VT THURSDAY
NIGHT. LOOKS LIKE AN UPSLOPE FLOW SETUP FOR A TIME THURSDAY
NIGHT...AND THERMAL FIELDS SUPPORT SNOW AT ELEVATIONS ABOVE
1000`...WITH A RAIN/SNOW MIX POSSIBLE IN VALLEY LOCATIONS LATER
THURSDAY NIGHT. LOWS THURSDAY NIGHT WILL BE NEAR FREEZING MOST
LOCATIONS...AND LOCALLY IN THE LOW- MID 20S ABOVE 2000 FEET
ELEVATION.
CYCLONIC FLOW REMAINS IN PLACE THROUGH FRIDAY...WITH ISOLD VALLEY
SHOWERS AND MORE FREQUENT RAIN/SNOW SHOWERS ACROSS THE HIGHER
ELEVATIONS. HIGHS FRIDAY REMAINING COOL...GENERALLY 45-50F.
MAY SEE SOME DECENT SNOWFALL ACCUMULATIONS ACROSS THE HIGHER
SUMMITS OF THE NRN ADIRONDACKS AND CENTRAL/NRN GREEN MTNS...MAINLY
THURSDAY NIGHT AND FRIDAY. CURRENT INDICATIONS SUPPORT AROUND 6"
OF NEW SNOW ALONG THE RIDGE TOPS FROM JAY PEAK TO MT.
MANSFIELD...AND SIMILARLY ACROSS THE HIGH PEAKS OF THE
ADIRONDACKS. MAY SEE A WET COATING-1" SNOWFALL AMTS DOWN TO ABOUT
1000` DURING THURSDAY NIGHT...WITH SNOW LEVELS RISING DURING THE
DAY FRIDAY TO ABOVE 2000`.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 352 AM EDT WEDNESDAY...CONTINUING THE THEME OF PERIODIC
APRIL SHOWERS WITH MOSTLY CLOUDY AND COOL WEATHER FROM CYCLONIC
NORTHWEST UPSLOPE FLOW AROUND A CLOSED UPPER LOW TO OUR NORTH AND
EAST.
MODEL CONSENSUS IS THAT THE LOW WILL INITIALLY BE OVER NORTHERN
MAINE FRIDAY NIGHT AND IT GRADUALLY FILLS AND MOVES SLOWLY EAST
INTO THE CANADIAN MARITIMES BY THE END OF THE PERIOD ON TUESDAY
WHICH WILL LESSEN THE CHANCE OF SHOWERS AS THE DAYS GO ON. STILL A
CHANCE OF SNOW SHOWERS ON THE UPPER PORTIONS OF THE MOUNTAINS BY
DAY WITH FREEZING LEVELS LOWERING OVERNIGHT POSSIBLY REACHING THE
VALLEY LOCATIONS WITH A MIX OF RAIN AND SNOW SHOWERS EARLY MORNING
HOURS.
MODELS CONTINUE TO BE IN DECENT AGREEMENT WITH THE LOCATION OF
THE UPPER LOW THROUGH SUNDAY THEN DIVERGE ON THE PLACEMENT MONDAY
AND TUESDAY. ECWMF A BIT OF AN OUTLIER COMPARED TO THE GFS, GEFS,
NAEFS, UK, AND CANADIAN MODELS WHICH ARE A BIT MORE PROGRESSIVE VS
THE ECMWF WHICH ACTUALLY SHOWS THE LOW RETROGRADING BACK OVER NEW
ENGLAND BY MONDAY NIGHT AND TUESDAY.
DAYTIME MAX TEMPERATURES WILL BE IN THE UPPER 40S TO MID 50S
THROUGHOUT THE LONG TERM WITH LOWS IN THE UPPER 20S TO MID 30S
WITH A SLIGHT UPWARD TREND NEXT WEEK.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...PERIODS OF MVFR CEILINGS AND VISIBILITIES
DEVELOPING AS RAIN SHOWERS MOVE INTO THE REGION, AND EVEN SOME
WET SNOW FLAKES MIXED IN AT SLK OVERNIGHT AS TEMPS DROP IN THE
BOUNDARY LAYER. SOME OF THE HIRES WINDOWS ARE SHOWING THAT THE
RAIN COULD BE HEAVY AT TIMES IN RUT/MPV HOWEVER GIVEN THE
UNCERTAINTY IN HOW HEAVY THE RAIN WILL FAIL I`VE CONTINUED TO
LEAVE IT OUT OF THE TAFS FOR NOW AND WILL MONITOR/UPDATE AS
NECESSARY.
SCATTERED TO BROKEN VFR CLOUDS AND SCATTERED RAIN SHOWERS WILL
PERSIST ACROSS THE REGION THROUGH TODAY. A WAVE OF LOW PRESSURE
WILL BRING A MORE ORGANIZED PERIOD OF LIGHT RAIN IN THE AFTERNOON
AND EVENING AS DEPICTED IN THE LATEST HRRR WHICH HAS A HANDLE ON
SHOWERS NOW ENTERING THE ST. LAWRENCE VALLEY. THE HRRR SEEMS A BIT
ON THE FASTER SIDE TO MOVE THE SHOWERS OUT SO I INITIALIZED THE
FORECAST WITH THE HRRR BUT THEN TRENDED MORE TOWARDS AN ENSEMBLE
OF THE LOCAL WRF`S FOR THE EVENING WITH REGARDS TO WX/VSBY. WINDS
SOUTH/SOUTHWEST LESS THAN 7 KNOTS BECOMING 10 KNOTS WITH GUSTS
15-20 KNOTS DURING THE DAY TODAY.
OUTLOOK 18Z THURSDAY THROUGH SUNDAY...
18Z THURS - 00Z SAT: VFR WITH PERSISTENT MOSTLY CLOUDY CONDITIONS
AND SOME POSSIBLE MVFR WITH OFF AND ON LIGHT RAIN. COULD BE A
SLIGHT MIX OF RAIN/SNOW LATE THURS EVENING.
00Z SAT - SUNDAY: VFR WITH PERIODS OF MVFR AS RAIN SHOWERS MOVE
THROUGH THE AREA.
&&
.HYDROLOGY...
RAINFALL AMOUNTS OF UP TO 0.50" ARE EXPECTED ACROSS CENTRAL/ERN
VT THIS AFTERNOON THROUGH THE FIRST HALF OF TONIGHT. SOME MODEST
RIVER RISES CAN BE EXPECTED LATE TODAY THROUGH TONIGHT. SINCE THE
BARTON RIVER AT COVENTRY HAD AN OBSERVED STAGE OF 7.6` AT 07Z THIS
MORNING...ANTICIPATE THAT ONE FORECAST POINT WILL LIKELY REACH
MINOR FLOOD STAGE (BETWEEN 8-9`) SOMETIME TONIGHT.
ELSEWHERE...RIVER RISES ARE EXPECTED TO BE WITHIN BANKFULL.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS/NEILES
SHORT TERM...BANACOS
LONG TERM...SISSON
AVIATION...DEAL/SISSON
HYDROLOGY...TEAM BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
121 PM EDT WED APR 22 2015
.SYNOPSIS...
A LARGE UPPER LEVEL LOW PRESSURE SYSTEM ACROSS THE GREAT LAKES
AND ONTARIO WILL DRIFT SLOWLY EASTWARD THROUGH THE END OF THE
WEEK. THIS SYSTEM WILL PROVIDE THE NORTH COUNTRY WITH SEASONABLY
COOL CONDITIONS...ALONG WITH CONSIDERABLE CLOUDINESS. EMBEDDED
SMALLER SCALE DISTURBANCES WILL BRING PERIODS OF RAIN
SHOWERS...WHICH WILL BE MOST WIDESPREAD LATE TODAY INTO TONIGHT.
SOME SNOW SHOWERS ARE POSSIBLE ACROSS THE HIGHER TERRAIN...WITH
SOME ACCUMULATING SNOW FOR THE SUMMITS ESPECIALLY THURSDAY NIGHT
INTO FRIDAY.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 120 PM EDT WEDNESDAY...GOING FORECAST IS IN REALLY GOOD
SHAPE. AREA OF SHOWERS LIFTING NORTH INTO OUR FORECAST AREA
CURRENTLY. ADJUSTED FORECAST TO REFLECT CURRENT OBSERVATIONS.
PREVIOUS DISCUSSION FOLLOWS.
NORTH COUNTRY WILL REMAIN IN DEEP-LAYER SWLY FLOW TODAY...AS
CLOSED UPPER LOW REMAINS QUASI- STATIONARY NORTH OF THE U.P. OF
MICHIGAN. SHORTWAVE TROUGH ROUNDING THE BASE OF THE 500MB TROUGH
WILL SHIFT NEWD FROM PA ACROSS NY/NEW ENGLAND DURING THE AFTN HRS.
THIS WILL ENHANCE UPWARD MOTION AND EXPAND COVERAGE OF SHOWER
ACTIVITY THIS AFTERNOON AND EVENING. ALL GUIDANCE CONSISTENT IN
SHOWING SHOWER ACTIVITY MOST WIDESPREAD ACROSS CENTRAL/ERN
VT...AND HAVE SHOWN HIGHEST POPS THERE (80-100 PERCENT)...AND
GENERALLY 50-80 PERCENT ACROSS THE CHAMPLAIN VALLEY WWD INTO THE
ADIRONDACKS.
BASED ON EARLY AM RADAR TRENDS...IT APPEARS ISOLD/SCT SHOWERS
WILL MOVE ACROSS NRN NY - AND PERHAPS INTO THE CHAMPLAIN VALLEY -
DURING THE MID MORNING HRS. SHOWERS MOVING GENERALLY NE 30-35 MPH
EAST OF LAKE ONTARIO AS OF 1120Z. HAVE CARRIED CHANCE POPS DURING
THE MORNING HRS TO COVER THIS SHOWER ACTIVITY AS IT MOVES NEWD.
OVERALL TREND WILL BE FOR ACTIVITY TO BECOME MORE WIDESPREAD AS
THE AFTERNOON PROGRESSES, ESPECIALLY FOR CENTRAL AND ERN VT. SUNNY
SKIES EXPECTED AT TIMES DURING THE MORNING HRS...BEFORE TRENDING
MOSTLY CLOUDY FOR THE AFTERNOON AND EVENING PERIOD. RAINFALL AMTS
GENERALLY A TENTH TO 0.30" FROM THE ADIRONDACKS EWD...WITH THE
HIGHEST TOTALS EXPECTED ACROSS ERN VT. MEANWHILE...RAINFALL
GENERALLY <0.10" ACROSS THE ST. LAWRENCE VALLEY. HIGH TEMPERATURES
TODAY GENERALLY EXPECTED IN THE MID-UPR 50S. SFC WINDS GENERALLY
SOUTH 10-15 MPH THIS MORNING...SHIFTING INTO THE SW AND WEST THIS
AFTN WITH TROUGH PASSAGE.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/...
AS OF 306 AM EDT WEDNESDAY...THE SHORT-TERM WILL FEATURE
CONTINUED SEASONABLY COOL AND MOIST CONDITIONS...WITH POTENTIAL
FOR UPSLOPE/OROGRAPHIC SNOWFALL THURSDAY NIGHT INTO
FRIDAY...INCLUDING LIGHT TO MODERATE ACCUMULATIONS FOR THE HIGHER
SUMMITS.
LINGERING RAIN SHOWERS ACROSS CENTRAL INTO NERN VT THIS EVENING
WILL GRADUALLY MOVE NEWD OUT OF THE REGION OVERNIGHT. MAY SEE AN
ADDITIONAL 0.10"-0.20" RAINFALL ACROSS CENTRAL/ERN VT BEFORE
ACTIVITY ENDS AROUND MIDNIGHT. SHOULD SEE AT LEAST SOME MODEST
RISES ON AREA RIVERS TONIGHT...AND MINOR FLOODING IS POSSIBLE FOR
THE BARTON RIVER AT COVENTRY BASED ON CURRENT EXPECTATIONS. WHILE
SKIES WILL REMAIN MOSTLY CLOUDY OVERNIGHT...LOW-LEVEL CAA FROM THE
WEST WILL ALLOW TEMPS TO FALL INTO THE LOW-MID 30S FOR OVERNIGHT
LOWS.
UPR LOW CENTER PROGRESSES ACROSS NRN NY AND VT ON
THURSDAY...MAINTAINING CLOUDY SKIES, ALONG WITH COOL AND MOIST
CONDITIONS. HIGH TEMPERATURES ON THURSDAY WILL BE WELL BELOW
SEASONABLE NORMS...AND GENERALLY IN THE MID TO UPPER 40S...AND
LOCALLY IN THE LOWER 40S FOR THE NRN ADIRONDACK REGION.
POTENTIAL FOR SHOWERS WILL GRADUALLY INCREASE AS NWLY FLOW
DEVELOPS ACROSS NRN NY THURSDAY AFTN...AND ACROSS VT THURSDAY
NIGHT. LOOKS LIKE AN UPSLOPE FLOW SETUP FOR A TIME THURSDAY
NIGHT...AND THERMAL FIELDS SUPPORT SNOW AT ELEVATIONS ABOVE
1000`...WITH A RAIN/SNOW MIX POSSIBLE IN VALLEY LOCATIONS LATER
THURSDAY NIGHT. LOWS THURSDAY NIGHT WILL BE NEAR FREEZING MOST
LOCATIONS...AND LOCALLY IN THE LOW- MID 20S ABOVE 2000 FEET
ELEVATION.
CYCLONIC FLOW REMAINS IN PLACE THROUGH FRIDAY...WITH ISOLD VALLEY
SHOWERS AND MORE FREQUENT RAIN/SNOW SHOWERS ACROSS THE HIGHER
ELEVATIONS. HIGHS FRIDAY REMAINING COOL...GENERALLY 45-50F.
MAY SEE SOME DECENT SNOWFALL ACCUMULATIONS ACROSS THE HIGHER
SUMMITS OF THE NRN ADIRONDACKS AND CENTRAL/NRN GREEN MTNS...MAINLY
THURSDAY NIGHT AND FRIDAY. CURRENT INDICATIONS SUPPORT AROUND 6"
OF NEW SNOW ALONG THE RIDGE TOPS FROM JAY PEAK TO MT.
MANSFIELD...AND SIMILARLY ACROSS THE HIGH PEAKS OF THE
ADIRONDACKS. MAY SEE A WET COATING-1" SNOWFALL AMTS DOWN TO ABOUT
1000` DURING THURSDAY NIGHT...WITH SNOW LEVELS RISING DURING THE
DAY FRIDAY TO ABOVE 2000`.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 352 AM EDT WEDNESDAY...CONTINUING THE THEME OF PERIODIC
APRIL SHOWERS WITH MOSTLY CLOUDY AND COOL WEATHER FROM CYCLONIC
NORTHWEST UPSLOPE FLOW AROUND A CLOSED UPPER LOW TO OUR NORTH AND
EAST.
MODEL CONSENSUS IS THAT THE LOW WILL INITIALLY BE OVER NORTHERN
MAINE FRIDAY NIGHT AND IT GRADUALLY FILLS AND MOVES SLOWLY EAST
INTO THE CANADIAN MARITIMES BY THE END OF THE PERIOD ON TUESDAY
WHICH WILL LESSEN THE CHANCE OF SHOWERS AS THE DAYS GO ON. STILL A
CHANCE OF SNOW SHOWERS ON THE UPPER PORTIONS OF THE MOUNTAINS BY
DAY WITH FREEZING LEVELS LOWERING OVERNIGHT POSSIBLY REACHING THE
VALLEY LOCATIONS WITH A MIX OF RAIN AND SNOW SHOWERS EARLY MORNING
HOURS.
MODELS CONTINUE TO BE IN DECENT AGREEMENT WITH THE LOCATION OF
THE UPPER LOW THROUGH SUNDAY THEN DIVERGE ON THE PLACEMENT MONDAY
AND TUESDAY. ECWMF A BIT OF AN OUTLIER COMPARED TO THE GFS, GEFS,
NAEFS, UK, AND CANADIAN MODELS WHICH ARE A BIT MORE PROGRESSIVE VS
THE ECMWF WHICH ACTUALLY SHOWS THE LOW RETROGRADING BACK OVER NEW
ENGLAND BY MONDAY NIGHT AND TUESDAY.
DAYTIME MAX TEMPERATURES WILL BE IN THE UPPER 40S TO MID 50S
THROUGHOUT THE LONG TERM WITH LOWS IN THE UPPER 20S TO MID 30S
WITH A SLIGHT UPWARD TREND NEXT WEEK.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THROUGH 12Z THURSDAY...PERIODS OF MVFR DEVELOPING WITH RAIN AND
MIST DEVELOPING, AND EVEN SOME WET SNOW FLAKES MIXED IN AT KSLK.
POSSIBLE IFR AT RUT/MPV FOR A FEW HOURS THIS AFTERNOON BUT
UNCERTAIN SO LEFT IT OUT FOR NOW.
SCATTERED TO BROKEN VFR CLOUDS AND SCATTERED RAIN SHOWERS WILL
PERSIST ACROSS THE REGION THROUGH TODAY. A WAVE OF LOW PRESSURE
WILL BRING A MORE ORGANIZED PERIOD OF LIGHT RAIN IN THE AFTERNOON
AND EVENING AS DEPICTED IN THE LATEST HRRR WHICH HAS A HANDLE ON
SHOWERS NOW ENTERING THE ST. LAWRENCE VALLEY. WINDS
SOUTH/SOUTHWEST LESS THAN 7 KNOTS BECOMING 10 KNOTS WITH GUSTS
15-20 KNOTS DURING THE DAY TODAY.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY...PERSISTENT MOSTLY CLOUDY
CONDITIONS WITH VFR CEILINGS AS UPPER LOW REMAINS IN PLACE.
PERIODS OF LIGHT RAIN SHOWERS WILL RESULT IN INTERMITTENT MVFR
CEILINGS/VISIBILITIES. ON THURSDAY SOME SNOW POSSIBLY WILL MIX IN
WITH RAIN SHOWERS AT MPV/SLK...AND A MIX OF RAIN/SNOW SHOWERS
POSSIBLE AT ALL TAF LOCATIONS DURING THURSDAY NIGHT AND FRIDAY
NIGHT. OTHERWISE MOSTLY RAIN SHOWERS SATURDAY AND SUNDAY.
&&
.HYDROLOGY...
RAINFALL AMOUNTS OF UP TO 0.50" ARE EXPECTED ACROSS CENTRAL/ERN
VT THIS AFTERNOON THROUGH THE FIRST HALF OF TONIGHT. SOME MODEST
RIVER RISES CAN BE EXPECTED LATE TODAY THROUGH TONIGHT. SINCE THE
BARTON RIVER AT COVENTRY HAD AN OBSERVED STAGE OF 7.6` AT 07Z THIS
MORNING...ANTICIPATE THAT ONE FORECAST POINT WILL LIKELY REACH
MINOR FLOOD STAGE (BETWEEN 8-9`) SOMETIME TONIGHT.
ELSEWHERE...RIVER RISES ARE EXPECTED TO BE WITHIN BANKFULL.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS/NEILES
SHORT TERM...BANACOS
LONG TERM...SISSON
AVIATION...SISSON
HYDROLOGY...TEAM BTV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
153 PM EDT WED APR 22 2015
.SYNOPSIS...
A BROAD AREA OF LOW PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER
OVER THE GREAT LAKES THROUGH THE END OF THE WEEK. THIS WILL SUPPORT
BELOW NORMAL TEMPERATURES AND THE CHANCE FOR SOME ON AND OFF RAIN
SHOWERS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED...A FEW ADJUSTMENTS TO THE FORECAST FOR THIS AFTERNOON.
WE ARE RECEIVING SEVERAL REPORTS OF MIXED PRECIPITATION OVER THE
AREA WITH SNOW AND GRAUPEL MIXING WITH THE RAIN. I WILL ADJUST
THE FORECAST TO MENTION THE MIXED PRECIPITATION. HIGH TEMPERATURES
ARE NOT RISING AS FAST AS EARLIER ANTICIPATED. I WILL BUMP THE
HIGH TEMPERATURES BACK A FEW DEGREES INTO THE MID 40S. I WILL ALSO
INCREASE THE CLOUD COVER.
ORIGINAL...UPPER LOW REMAINS IN PLACE ACROSS THE ONTARIO/QUEBEC
REGION. AT THE SURFACE A COLD FRONT CONTINUES TO MOVE THROUGH THE
AREA SPREADING RAIN SHOWERS INVOF THE FRONT. THE FRONT WILL
CONTINUE SOUTHEAST TODAY AND SHOULD BE MOVING EAST OF THE AREA
EARLY THIS MORNING. EXPECTING SHOWERS TO CONTINUE MOST AREAS
THROUGH THE PREDAWN HOURS. AFTER DAWN SHOWERS SHOULD AFFECT MAINLY
SOUTHERN AND EASTERN COUNTIES WITH THE MAIN AREA OF RAIN SOUTHEAST
BY 14-15Z. HRRR DOES SHOW SOME REDEVELOPMENT EASTERN HALF OF THE
AREA LATE MORNING SO WILL HOLD ONTO POPS THERE. THERE ARE SOME
BREAKS IN THE CLOUDS MAINLY ACROSS NWRN OHIO AND SRN LWR MI BUT
THROUGH THE MORNING THIS SHOULD FILL IN WITH SUCH COLD AIR ALOFT
AND ADDITIONAL WRAP AROUND MOISTURE DROPPING ACROSS THE AREA IN
THE AFTERNOON. HIGHS TODAY WILL LIKELY NOT RISE TOO MUCH FROM
MORNING LOWS GIVEN THE COLD ADVECTION ACROSS THE AREA. RISES
LIKELY ON THE ORDER OF 5 DEGREES OR SO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
THE NAM SHOWS NO BIG CHANGES IN STORE FOR NRN OHIO AND NWRN PA
THROUGH THURSDAY AT LEAST WITH PLENTY OF MOISTURE ROTATING ACROSS
THE AREA AROUND THE CLOSED STAGNANT UPPER LOW. THE CIRCULATION
SHIFTS EAST ENOUGH BY FRIDAY TO GET DRIER AIR INTO THE AREA BUT
STILL NO WARM UP WITH 850MB TEMPS BELOW ZERO AND WELL BELOW NORMAL.
SATURDAY MOISTURE WILL RETURN AS LOW PRESSURE MOVES EAST ACROSS
THE LOWER OHIO VALLEY. DEPENDING ON THE PATH WE COULD GET SHOWERS
ASSOCIATED WITH THE LOW INTO THE AREA SO DID PUT IN A CHANCE POP
WESTERN TWO THIRDS.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE FORECAST PERIOD.
BOTH MODELS CONTINUE IN GOOD AGREEMENT WITH HIGH PRESSURE PUSHING
SOUTHEAST ACROSS THE AREA ON SUNDAY. HIGH REMAINS ENTRENCHED OVER
THE FORECAST AREA MONDAY AS LOW PRESSURE TRACKS UP THE EAST COAST.
MODELS DIVERGE ON TUESDAY AS GFS MOVES LOW PRESSURE SYSTEM ACROSS
THE UPPER OHIO VALLEY WHILE ECMWF CONTINUES WITH HIGH PRESSURE OVER
THE AREA. WILL CONTINUE WITH PREVIOUS FORECAST WHICH TRENDED TOWARD
GFS WITH LOW CHANCE POPS.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
SCATTERED SHOWERS WILL CONTINUE TO MOVE EAST ACROSS NORTHEAST OHIO
THROUGH 21Z. THESE SHOWERS WILL IMPACT YNG AND POSSIBLY CAK WITH A
CHANCE OF BRIEF ICE PELLETS MIXING IN. OTHERWISE EXPECTING
PREDOMINANTLY VFR CONDITIONS INTO THIS EVENING...LOWERING TO MVFR
OVERNIGHT IN NE OHIO/NW PA. THERE WILL BE A CHANCE OF SNOW
SHOWERS...MAINLY AT ERI/YNG AFTER 05Z. BREEZY WESTERLY WINDS WITH
GUSTS TO AROUND 25 KNOTS WILL CONTINUE THIS AFTERNOON WITH GUSTS
DROPPING OFF AFTER 00Z. GUSTY WINDS WILL RETURN AFTER 14Z ON
THURSDAY.
.OUTLOOK...MVFR CEILINGS AT TIMES THURSDAY MAINLY EXTREME NORTHEAST
OH AND NORTHWEST PA. LOW CONFIDENCE IN NON VFR CONDITIONS
RETURNING SATURDAY NIGHT THROUGH SUNDAY NIGHT.
&&
.MARINE...
SMALL CRAFT ADVISORY WILL CONTINUE INTO THURSDAY NIGHT. GUSTY WEST
TO SOUTHWEST WINDS WILL CONTINUE INTO THURSDAY NIGHT AS LOW PRESSURE
SLOWLY DRIFTS ACROSS EASTERN CANADA. WINDS WILL BECOME LIGHTER BY
FRIDAY AND FRIDAY NIGHT AS HIGH PRESSURE BUILDS SLOWLY OVER THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THURSDAY FOR LEZ142>146.
&&
$$
SYNOPSIS...TK
NEAR TERM...GARNET
SHORT TERM...TK
LONG TERM...DJB
AVIATION...KEC
MARINE...DJB
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
402 PM CDT WED APR 22 2015
.DISCUSSION...
UPPER AIR ANALYSIS AND WATER VAPOR IMAGERY STILL SHOW A RATHER
PERSISTENT SOUTHERN JET STREAM OVER MUCH OF TX. IT IS HARD TO
IDENTIFY BUT IT APPEARS THAT THE CONVECTION OVER THE COASTAL BEND
AND NOW EAST OF SAN ANTONIO MAY BE SUPPORTED BY A WEAK SHORTWAVE
TROUGH. OVERALL PATTERN SHOWS WEAK SHORT WAVE RIDGING BUT THIS
DISTURBANCE MAY BE FLATTENING OUT THE RIDGE A BIT TODAY.
THERMODYNAMIC AND SHEAR PARAMETERS SUPPORT THE THREAT FOR SEVERE
STORMS WITH SOME STORMS BECOMING ORGANIZED. SHEAR WILL SUPPORT
STORM ROTATION AND LOW LEVEL TURNING OF THE WINDS WITH A
DEVELOPING WARM FRONT MAY BE ENOUGH TO SUPPORT LOW LEVEL ROTATION
IN STORMS ESPECIALLY ALONG THE COASTAL BEND. RECENT RAP/HRRR MODEL
RUNS BRING CONVECTION EAST OF KSAT INTO SE TX AROUND 23-01Z.
MODELS SHOW THAT STORMS MAY BE WEAKENING BUT COULD BE MOVING INTO
A MORE FAVORABLE ENVIRONMENT GIVEN TRENDS IN HEATING/INSTABILITY.
MODELS ALSO SHOW CONVECTION ALONG A BOUNDARY STRETCHING NW/SE FROM
MINERAL WELLS TO LUFKIN. THIS HIGHLIGHTS THE SEVERE THREAT FOR THE
NORTHERN MOST COUNTIES IN THE FORECAST AREA MAINLY
MADISON...HOUSTON...TRINITY CO. THE IDEA IS FOR THE THREAT TO END
LATER TONIGHT BUT HRRR TRENDS SHOW CONVECTION COMING DOWN FROM
THE METROPLEX AND AFFECT THE AREAS FROM COLLEGE STATION TO
HUNTSVILLE OVER THE LIVINGSTON BY EARLY MORNING HOURS. SO IT
APPEARS THERE WILL BE AT LEAST SOME OVERNIGHT THREAT.
THURSDAY LOOKS A BIT MORE QUIET AS MODELS DO AMPLIFY RIDGING OVER
THE REGION ALTHOUGH THERE WILL BE PLENTY OF MOISTURE/INSTABILITY
TO SUPPORT SEVERE STORMS. WE DO NOT WANT TO BE COMPLACENT BUT
THINK 20/30 POPS MIGHT BE GENEROUS. MOVING AHEAD TO
FRIDAY...RIDGING MOVES EAST IN RESPONSE TO UPPER LEVEL TROUGH OVER
THE S ROCKIES PUSHING INTO THE TX PANHANDLE AND S PLAINS. SFC LOW
DEEPENS AND MOVES INTO THE C PLAINS IN RESPONSE WITH STRONG JET
STREAK FROM MIDLAND TO OKC. THIS PUTS SE TX ON A MORE SUBSIDENT
SIDE OF THE JET BUT THAT MAY NOT MATTER MUCH WITH THE CURVATURE OF
THE JET. THERE IS ALSO A PACIFIC FRONT THAT DEVELOPS WITH
CONVECTION FORMING IN C TX MOVING EAST. THIS WILL AGAIN PUT AREAS
NORTH OF I-10 IN A THREAT FOR SEVERE WEATHER SINCE THERE WILL
AGAIN BE PLENTY OF MOISTURE/INSTABILITY AND SHEAR. MAIN QUESTION
WILL BE CAP STRENGTH. 850MB WINDS VEER TO SW WITH TEMPS AROUND 20C
OR MORE FOR MUCH OF THE SOUTHERN HALF OF THE AREA. AGAIN THIS
SUPPORTS IDEA OF AREAS NORTH OF I-10 OR EVEN NORTH OF CONROE WILL
HAVE A HIGHER THREAT FOR SEVERE WEATHER FRIDAY.
WE CONTINUE THUNDERSTORM CHANCES SATURDAY AS THE THROUGH PASSES NE
OF THE AREA OVERNIGHT. SOUTHERN JET STILL IS STRONG OVER THE
REGION. PACIFIC FRONT STALLS OVER THE AREA WHICH COULD SUPPORT A
FEW STORMS BUT WITH 850MB FLOW BECOMING MORE WSW...THINK STORMS
WILL BE ISO IN NATURE. WITH THE VEERED BOUNDARY LAYER FLOW...MAX
TEMPS COULD REACH UPPER 80S TO 90F BOTH SAT/SUN.
WHILE THERE MAY BE A BREAK FROM SEVERE WEATHER OVER THE
WEEKEND...MONDAY COULD BE ACTIVE AGAIN. BOTH GFS/ECMWF BRING A
UPPER LOW INTO THE PLAINS DURING THE DAY MON WITH FAVORABLE
SPLITTING JET STRUCTURE. LARGE SCALE ASCENT WILL BE STRONG ENOUGH
TO ERODE ANY CAPPING LEADING TO A MID MORNING TO EARLY AFTERNOON
SEVERE WEATHER CHANCES. DRYLINE/PACIFIC FRONT PUSHES THROUGH MON
NIGHT INTO TUE AS THUNDERSTORM ACTIVITY MOVES EAST. A STRONGER
COLD FRONT PUSHES THROUGH TUESDAY WHICH MUCH COLDER AIR BEHIND IT.
IN FACT THE 850MB TEMPS DROP TO ANYWHERE BETWEEN 4C AND 8C TUE
NIGHT INTO WED DEPENDING ON THE MODEL. SO IT LOOKS LIKE MONDAY
WILL NEED TO BE WATCHED CLOSELY FOR DETAILS ON SEVERE WEATHER BUT
GOOD NEWS THAT THERE COULD BE A STRONG COLD FRONT TO PUSH THROUGH
ONE LAST TIME BEFORE HEADING INTO THE MONTH OF MAY.
39
&&
.MARINE...
AS HIGH PRESSURE LINGERS TO THE EAST AND PRESSURES FALL OVER THE SRN
PLAINS...THE LIGHT/MODERATE ONSHORE FLOW WILL BE CONTINUING OVER THE
UPPER TX COAST THROUGH THE END OF THE WEEK/INTO THE WEEKEND. STRONG-
ER GUSTS/LIMITED VISIBILITIES POSSIBLE WITH STORMS DEVELOPING ACROSS
THE COASTAL WATERS THE REST OF THIS AFTN/EVENING...WITH LATER ROUNDS
OF PCPN POSSIBLE THURS AND FRI. LONG-RANGE MODELS STILL GOING WITH A
STRONG COLD FRONT INTO THE GULF WATERS NEXT TUES. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 70 85 71 83 68 / 40 30 30 60 20
HOUSTON (IAH) 69 86 73 84 71 / 20 20 20 40 20
GALVESTON (GLS) 72 82 73 82 73 / 20 20 20 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AVIATION/MARINE...41
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
231 PM CDT WED APR 22 2015
.SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
SEMI ACTIVE WEATHER PATTERN FOR THE NEXT FEW DAYS FOLLOWED BY A
FRONT THIS WEEKEND THEN DRYING OUT EARLY NEXT WEEK.
AS OF 2 PM THERE IS A MULTICELL CLUSTER OF THUNDERSTORMS
APPROACHING BEXAR COUNTY AND SAN ANTONIO. THE HRRR TAKES THIS
COMPLEX AS WELL AS OTHER SHOWERS AND THUNDERSTORMS OUT AHEAD OF IT
EASTWARD IMPACTING A BASTROP SOUTH TO GONZALES AND KENEDY LINE.
MODEL SOUNDINGS FROM THE NAM SHOW AN UNCAPPED ATMOSPHERE ALONG
AND EAST OF I-35 THIS AFTERNOON WITH 1000-3000 J/KG OF CAPE AND
50-60 KNOTS OF SHEAR. THIS MEANS THAT THIS COMPLEX OF STORMS IS
MOVING INTO A VERY GOOD ENVIRONMENT FOR STRONG TO SEVERE STORMS.
WE CONTINUE UNDER A SLIGHT RISK FROM SPC THIS AFTERNOON ALONG AND
EAST OF US HWY 281. WE HAVE ALSO SEEN HEAVY RAINFALL RATES OUT OF
THE ONGOING STORMS SO SOME LOCALIZED FLOODING IS NOT OUT OF THE
QUESTION WITH THE STRONGER STORMS. THE MAIN THREATS WILL BE LARGE
HAIL AND DAMAGING WINDS WITH ANY SEVERE WEATHER THAT DOES OCCUR
THIS AFTERNOON AND EVENING. THE THREAT FOR TORNADOES REMAINS LOW
AS LOW LEVEL SHEAR IS WEAK.
OTHER FEATURES IN PLAY TODAY ARE A STATIONARY FRONT ACROSS THE
RED RIVER IN NORTH TEXAS AND THE DRYLINE OUT IN WEST
TEXAS...ALTHOUGH OTHER THAN AN ISOLATED DRYLINE STORM NEITHER WILL
IMPACT OUR WEATHER MUCH. GENERAL RIDGING IS FORECAST TO TAKE
PLACE THROUGH THE PERIOD AS HIGH PRESSURE OVER NORTHERN MEXICO
MOVES SLOWLY EAST. CONVECTION WILL DECREASE OVERNIGHT TONIGHT AND
WITH NORTHWEST FLOW CONTINUING ONLY SLIGHT CHANCES FOR
PRECIPITATION ARE FORECAST FOR THURSDAY THROUGH THURSDAY EVENING.
MODEL SOUNDINGS SHOW A STRONG CAP ACROSS MOST OF SOUTH CENTRAL
TEXAS DURING THE DAY TOMORROW. BY LATE IN THE AFTERNOON MODELS DO
WEAKEN THE CAP WHICH COULD ALLOW FOR SOME ISOLATED SHOWERS AND
THUNDERSTORMS. AGAIN...CONDITIONS WILL BE FAVORABLE TOMORROW FOR
SEVERE WEATHER WITH 50 KNOTS OF UPPER LEVEL SHEAR AND 2000-3000
J/KG OF CAPE. THE DAY 2 OUTLOOK FROM SPC HAS THE WHOLE AREA IN A
SLIGHT RISK FOR TOMORROW...WITH LARGE HAIL AND DAMAGING WINDS
AGAIN THE PRIMARY THREATS.
&&
.LONG TERM (FRIDAY THROUGH WEDNESDAY)...
MODELS ARE IN AGREEMENT THAT THURSDAY NIGHT THROUGH FRIDAY MORNING
WILL BE A PERIOD OF HIGHER QPF...HIGHER RAIN CHANCES. THE GREATEST
CHANCES FOR RAIN WILL BE ALONG THE RIO GRANDE PLAINS THURSDAY
NIGHT SPREADING TO AREAS ALONG AND EAST OF I-35 FOR FRIDAY. AN
UPPER LEVEL TROUGH APPROACHING FROM THE WEST WILL PROVIDE THE
NEEDED LIFT FOR THIS PRECIPITATION. CHANCES OF SEVERE WEATHER
CONTINUE INTO FRIDAY WITH THE BEST INSTABILITY LOCATED ALONG AND
WEST OF I-35. AS THE TROUGH MOVES OFF TO THE EAST AND NORTHEAST
SATURDAY CHANCES FOR RAIN WILL DECREASE THROUGH THE DAY. THE NEXT
FRONT WILL MOVE THROUGH SUNDAY INTO MONDAY. THE GFS AND NEW 12Z
ECMWF DISAGREE BY ABOUT 24 ON THE TIMING OF THIS FRONT...WITH THE
ECMWF BRING THE SLOWER OF THE TWO. WILL GO WITH A PERSISTENCE
FORECAST AND CHANCE POPS FOR SUNDAY AND MONDAY...DRYING OUT
TUESDAY. THE ONE BENEFIT OF THIS FRONT IS IT WILL COOL THE AREA
BACK DOWN INTO THE 70S FOR HIGHS FOR A FEW DAYS BY THE MIDDLE OF
NEXT WEEK.
TREADWAY
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 70 88 70 85 67 / 30 30 40 60 30
AUSTIN BERGSTROM INTL AIRPORT 69 87 70 84 66 / 30 30 40 50 30
NEW BRAUNFELS MUNI AIRPORT 69 88 71 85 67 / 20 20 40 50 40
BURNET MUNI AIRPORT 67 87 68 84 64 / 30 40 40 60 20
DEL RIO INTL AIRPORT 69 90 68 88 64 / 10 20 50 30 30
GEORGETOWN MUNI AIRPORT 69 87 70 84 65 / 30 40 40 60 20
HONDO MUNI AIRPORT 70 88 71 85 66 / 20 20 40 40 50
SAN MARCOS MUNI AIRPORT 69 87 70 84 67 / 20 30 40 50 40
LA GRANGE - FAYETTE REGIONAL 70 87 72 85 69 / 30 30 30 50 40
SAN ANTONIO INTL AIRPORT 70 88 71 85 68 / 20 20 40 50 50
STINSON MUNI AIRPORT 71 88 71 85 69 / 20 20 40 40 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...76
SYNOPTIC/GRIDS...12
DATA COLLECTION/RADAR...26/15
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
248 PM CDT WED APR 22 2015
.SHORT TERM...TONIGHT THROUGH SATURDAY
.TONIGHT AND THURSDAY...FORECAST CONFIDENCE HIGH.
LOOK FOR VERY ISOLATED CHANCES OF RAIN AND SNOW SHOWERS TO CONTINUE
THIS AFTERNOON INTO THE EARLY EVENING BUT WILL FINALLY BEGIN TO
BREAK TONIGHT AS AN EXTENSIVE SFC LOW PRESSURE SYSTEM WILL MOVE OFF
TO THE EAST. A 500 MB SHORTWAVE TROUGH WITH ASSOCIATED SHEARED
POSITIVE VORTICITY ADVECTION WILL PERSIST OVER THE REGION THROUGH
THURSDAY AFTERNOON...BUT CONDITIONS LOOK TO BE CLEAR AS THE
ENVIRONMENTAL PROFILES FROM NAM AND RAP BUFKIT SOUNDINGS LOOK TO DRY
OUT OVERNIGHT. GUSTY NORTHWEST WINDS WILL CONTINUE TONIGHT...BUT
WILL WEAKEN AS SFC PRESSURE GRADIENT WEAKENS.
THURSDAY LOOKS LIKE A QUIETER DAY AS SFC HIGH PRESSURE MOVES INTO
THE REGION FROM THE NORTHWEST. MID-LEVEL HEIGHTS WILL RISE AS THE
HIGH PRESSURE APPROACHES. THE CAVEAT THURSDAY WILL BE CONTINUED COLD
TEMPERATURES AS WE REMAIN IN A NORTHWEST FLOW REGIME. 925 MB
TEMPERATURES WILL ONCE AGAIN BE IN THE SINGLE NEGATIVE DIGITS...WITH
LOWS DROPPING INTO THE UPPER 20S ACROSS SOUTHERN WISCONSIN. THE GOOD
NEWS IS SKIES WILL CLEAR THURSDAY AS A DRIER AIRMASS MOVES IN.
ABUNDANT SUNSHINE WILL HELP INCREASE OUR TEMPERATURES BACK INTO THE
LOWER 50S.
.THURSDAY NIGHT THROUGH SATURDAY...FORECAST CONFIDENCE MEDIUM.
QUIET CONDITIONS CONTINUE FOR THURSDAY NIGHT AND FRIDAY AS SFC
RIDGING TAKES HOLD. GOOD RADIATIONAL COOLING THURSDAY NIGHT WILL
ALLOW NEAR TO BELOW FREEZING LOW TEMPERATURES AWAY FROM THE
LAKESHORE. RIDGE SHIFTS EAST OF THE REGION FRIDAY NIGHT AS A
SHORTWAVE IMPULSE EJECTS FROM THE CENTRAL PLAINS INTO IOWA AND
MISSOURI. ASSOCIATED SFC LOW TRACKS FROM NEBRASKA INTO MISSOURI
SATURDAY MORNING...WITH PCPN SHIELD BRUSHING SOUTHERN WISCONSIN
FRIDAY EVENING. BEST OMEGA AND LAYER Q-VECTOR CONVERGENCE ARRIVES
FRIDAY NIGHT AND LASTS THROUGH EARLY SATURDAY. KEPT CHANCE POPS IN
PLACE DURING THIS TIME. TEMPS IN THE NORTHERN CWA WILL BE NEAR
FREEZING FRIDAY NIGHT...WITH A RAIN-SNOW MIX POSSIBLE. WARM
ADVECTION SHOULD KICK IN SATURDAY MORNING...WITH PCPN
TRANSITIONING TO ALL RAIN. ANY LINGERING SHOWERS SHOULD COME TO AN
END SATURDAY NIGHT. HIGHS WARM INTO THE 50S AWAY FROM THE LAKE ON
FRIDAY...BEFORE TURNING COOLER ON SATURDAY.
.LONG TERM...SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE
MEDIUM.
DECENT MODEL AGREEMENT ON SFC RIDGING TAKING HOLD ACROSS THE
EASTERN GREAT LAKES REGION ON SUNDAY AND MONDAY. TEMPERATURES
MODERATE A BIT FROM SATURDAY...WITH HIGHS IN THE 50S LOWER 60S.
THEREAFTER...12Z GFS/00Z ECMWF RUNS ARE TAKING A MORE SOUTHERLY
TRACK WITH A LOW PRESSURE SYSTEM INITIALLY OVER THE TX PANHANDLE
ON MONDAY. WHILE PREVIOUS GFS RUN LIFTED IT WELL INTO
MISSOURI...CONSENSUS TRACK IS NOW INTO THE LOWER MISSISSIPPI
VALLEY. IN LIGHT OF THIS...AND PER COORDINATION WITH SURROUNDING
WFOS...REMOVED POPS FOR MONDAY AND EARLY TUESDAY. KEPT CHANCE
POPS FOR TUESDAY AFTERNOON INTO WEDNESDAY WITH ECMWF SHOWING
BETTER SHORTWAVE ENERGY AND GENERATING SOME LIGHT PCPN.
&&
.AVIATION/00Z TAFS/...LOW END VFR CIGS WILL CONTINUE INTO THE EARLY
EVENING AS A PERSISTENT STRATOCUMULUS DECK WILL STICK AROUND THE
AREA. THE RAP AND NAM BUFKIT SOUNDINGS SHOW THE ATMOSPHERIC PROFILE
DRYING OUT LATER THIS EVENING...IMPROVING CIG HEIGHTS. VERY ISOLATED
RAIN AND SNOW SHOWERS ARE POSSIBLE THIS AFTERNOON AND EARLY EVENING
UNTIL A DRIER AIRMASS MOVES IN DURING THE OVERNIGHT HOURS. NORTHWEST
WINDS WILL REMAIN GUSTY INTO THE EARLY EVENING HOURS...WITH GUSTS
NEAR 25 KTS POSSIBLE. WINDS WILL WEAKEN AFTER 00Z THURSDAY.
&&
.MARINE...A SMALL CRAFT ADVISORY IS IN EFFECT UNTIL 00Z THURSDAY.
NORTHWEST WINDS WILL REMAIN GUSTY INTO THE EARLY EVENING
HOURS...WITH GUSTS NEAR 25 KTS POSSIBLE. WINDS SHOULD WEAKEN AFTER
00Z AS SFC PRESSURE GRADIENT WEAKENS. WAVES WILL BE 1-2 FT UNTIL
THE WINDS WEAKEN.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LMZ643>646.
&&
$$
TONIGHT/THURSDAY AND AVIATION/MARINE...JTS
THURSDAY NIGHT THROUGH WEDNESDAY...SPM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
243 PM CDT WED APR 22 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 243 PM CDT WED APR 22 2015
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER TROUGHS OVER BRITISH COLUMBIA...ALONG THE SOUTHERN
CALIFORNIA COAST...AND OVER THE FORECAST AREA INTO THE GREAT
LAKES...WHILE RIDGING EXTENDED FROM THE FOUR CORNERS OF THE U.S.
INTO ALBERTA. CYCLONIC FLOW OF MOISTURE AROUND THE GREAT LAKES UPPER
TROUGH...NICELY SEEN ON THE 12Z GRB SOUNDING...HELPING TO HOLD
STRATOCUMULUS ACROSS WI. GO A LITTLE MORE TO THE WEST OVER MN AND
IA...MUCH DRIER AIR WAS PRESENT ON THE 12Z MPX SOUNDING WITH A
PRECIPITABLE WATER OF 0.16 INCHES OR 36 PERCENT OF NORMAL. THIS
DRIER AIR HAS RESULTED IN CLEARER SKIES. A RIDGE OF HIGH PRESSURE
ACCOMPANYING THE CLEAR SKIES WAS LOCATED OVER THE EASTERN DAKOTAS. A
TIGHT PRESSURE GRADIENT EAST OF THIS RIDGE MAINTAINING A BRISK
NORTHWEST BREEZE OVER THE FORECAST AREA WITH SPEEDS/GUSTS A LITTLE
LOWER THAN 24 HRS AGO. STILL...THE SPEEDS HAVE BEEN STRONG ENOUGH TO
WARRANT THE EARLIER ISSUED WIND ADVISORY FOR A SMALL PORTION OF
NORTHEAST IOWA. AIRMASS REMAINS UNSEASONABLY COOL WITH 850MB TEMPS
IN THE -5 TO -8C RANGE...RESULTING IN THE PRESENT 40S
TEMPERATURES...AND EVEN 30S AT MEDFORD WI.
THE UPPER TROUGH AFFECTING THE FORECAST AREA INTO THE GREAT LAKES IS
PROGGED TO MAKE MUCH MORE EASTWARD PROGRESS OVER THE NEXT 24
HOURS...REACHING NEW ENGLAND BY 00Z FRI. THIS WILL ALLOW THE RIDGING
AND WARMER/DRIER AIR OVER THE NORTHERN ROCKIES AND PLAINS TO MARCH
TOWARDS THE FORECAST AREA. WE DO HAVE ONE SHORTWAVE TO CONTEND WITH
COMING DOWN THE BACK SIDE OF THE UPPER TROUGH TONIGHT...WHICH ITS
MAIN IMPACT IS TO BRING IN SLIGHTLY COOLER AIR FOR 12Z THU BEFORE
THE WARMING COMMENCES.
CLOUDS MAY BE A BIT PERSISTENT NORTHEAST OF I-94 TONIGHT...THANKS TO
THAT SHORTWAVE COMING THROUGH...BUT ELSEWHERE ANY STRATOCUMULUS WILL
DISSIPATE WITH LOSS OF DAYTIME HEATING. THIS CLEARING COMBINED WITH
WINDS DIMINISHING SOME AS THE RIDGE APPROACHES I-35 BY 12Z THU IS
EXPECTED TO RESULT IN A CHILLY NIGHT. 20S SHOULD BE COMMON ACROSS
MUCH OF THE REGION BY SUNRISE WITH PERHAPS NEAR 30 READINGS IN THE
MS RIVER VALLEY. NO FROST/FREEZE HEADLINES WILL BE POSTED YET AS
VEGETATION GROWTH IS NOT QUITE THERE. 850MB TEMPS ON THU CLIMB TO 0
TO -2C BY 00Z FRI WHICH WITH PLENTY OF SUN SHOULD BE ABLE TO BOOST
TEMPERATURES INTO THE LOW TO MID 50S FOR MOST LOCATIONS. MEDFORD
AGAIN MIGHT BE THE LONE COOLER EXCEPTION BEING CLOSER TO THE
DEPARTING COLD AIR. DEEP MIXING IS LIKELY AS WELL IN THE DRY AIRMASS
FEATURING PRECIPITABLE WATER NEAR 0.10 INCHES...CAUSING LOW RELATIVE
HUMIDITY VALUES. THE COMBINATION OF THESE LOW VALUES AND A 10 TO 15
MPH NORTHWEST BREEZE COULD RESULT IN SOME FIRE WEATHER CONCERN. SEE
FIRE WEATHER SECTION BELOW FOR MORE DETAILS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 243 PM CDT WED APR 22 2015
FIRST FOCUS OF THE LONG TERM PERIOD IS ON THE UPPER TROUGH NEAR THE
SOUTHERN CALIFORNIA COAST. MODELS ARE IN GOOD AGREEMENT LIFTING THIS
TROUGH INTO THE CENTRAL PLAINS ON FRIDAY AND INTO CENTRAL ILLINOIS
ON SATURDAY. ALTHOUGH THIS TRACK IS SOUTH OF THE FORECAST AREA...WE
STILL HAVE SOME SHOT AT PRECIPITATION DURING THE FRIDAY-SATURDAY
TIME FRAME. PART OF THIS IS DUE TO A SOMEWHAT DECENT MOISTURE SURGE
AHEAD OF THE TROUGH UP INTO THE FORECAST AREA ON FRIDAY...REFLECTED
BY PRECIPITABLE WATER CLIMBING TO AROUND 0.75 INCHES BY 00Z SAT.
ADDITIONALLY...A SHORTWAVE IS PROGGED TO EJECT OUT OF THE TROUGH AND
MOVE THROUGH THE AREA ON FRIDAY...INTERACTING WITH THE MOISTURE.
THEREFORE...CHANCES OF PRECIPITATION PERSIST FOR FRIDAY...ESPECIALLY
IN THE AFTERNOON AND INTO THE NIGHT WEST OF THE MS RIVER WHERE MORE
MOISTURE EXISTS. PRECIPITATION SHOULD BEGIN TO WANE NORTH TO SOUTH
ON SATURDAY AS THE UPPER TROUGH MOVES EAST OF OUR LONGITUDE...
CUTTING OFF THE MOISTURE TRANSPORT AND ALLOWING DRIER AIR TO GET
DRAWN IN FROM THE NORTH AND EAST. SOME MODEL DIFFERENCES EXIST ON
HOW MUCH PRECIPITATION EXISTS ON SATURDAY DUE TO SLIGHT NORTH/SOUTH
DIFFERENCES OF THE UPPER TROUGH TRACK...WITH THE 22.12Z GFS/CANADIAN
FARTHEST NORTH UP TO US-10 AND 22.12Z NAM/ECMWF FARTHEST SOUTH TO
AROUND US-20. THEREFORE...PRECIPITATION CHANCES ON SATURDAY REMAIN
AT OR BELOW 50 PERCENT. BETWEEN THE CLOUDS AND PRECIPITATION...HIGH
TEMPERATURES LOOK TO BE A LITTLE COOLER THAN ON THU.
A DRIER AND WARMER PERIOD IS ON TAP FOR SUNDAY AS AN UPPER RIDGE
AXIS APPROACHES THE FORECAST AREA FROM THE WEST. WITH 850MB TEMPS OF
0-2C...SHOULD SEE HIGHS CLIMB WELL UP INTO THE 50S AND POSSIBLY 60S
IN RIVER VALLEYS. EASTERLY FLOW FROM HIGH PRESSURE OVER ONTARIO
LIKELY TO CAUSE RELATIVE HUMIDITIES TO TANK.
MODELS HAVE CHANGED THEIR TUNE A BIT FOR SUNDAY NIGHT THROUGH MONDAY
NIGHT...LEANING TOWARDS DRIER AND WARMER. THIS IS A RESULT OF A
SHORTWAVE TROUGH COMING INTO THE PACIFIC NORTHWEST ON SATURDAY
THAT...INSTEAD OF HEADING TOWARDS THE FORECAST AREA...NOW DIGS DOWN
INTO THE SOUTHERN PLAINS. THEREFORE HAVE FOLLOWED SUIT...DRYING OUT
THE FORECAST AND RAISING TEMPERATURES.
AS WE HEAD INTO TUESDAY AND WEDNESDAY...UPPER RIDGING IS PROGGED TO
DEVELOP OVER THE WESTERN U.S. INTO WESTERN CANADA...CAUSING
SHORTWAVES TO DROP INTO THE REGION ON NORTHERLY FLOW. AS A
RESULT...SOME LOW PRECIPITATION CHANCES ARE IN THE FORECAST. HARD TO
SAY HOW MUCH PRECIPITATION WILL FALL GIVEN LACK OF MOISTURE
AVAILABILITY. DESPITE THE NORTHERLY FLOW...850MB TEMPS ARE STILL
PROGGED IN THE 2-4C RANGE SO TEMPERATURES DO NOT LOOKS TO CHANGE
MUCH FROM MONDAY AND STAY JUST BELOW SEASONABLE NORMALS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1227 PM CDT WED APR 22 2015
ANOTHER DAY OF COLDER CYCLONIC FLOW WITH ENOUGH PRESSURE GRADIENT
AND MIXING TO PRODUCE STRONG NORTHWEST WINDS. WIND GUSTS IN PARTS OF
NORTHEAST IOWA HAVE HIT 30 TO 35 KTS. MEANWHILE VFR CEILINGS STILL
HOLDING TOUGH NEAR AND EAST OF MISSISSIPPI RIVER. CUMULUS FIELD IS
FILLING IN ON WESTERN EDGE BUT DRIER AIR ALOFT IS BATTLING THAT SO
EXPECT CLEARING TO PUSH EAST WITH LOSS OF HEATING GOING INTO THIS
EVENING. THE FURTHER EAST AND NORTHEAST YOU GO...HIGH RISK OF
CEILINGS STICKING AROUND BUT GENERALLY SHOULD REMAIN VFR.
SLOW PROGRESS OF UPPER LOW COULD RESULT IN MORE PREVAILING SUNSHINE
INTO THURSDAY...AND AS COLD POOL ALOFT ALSO SHIFTS...LESS RISK OF
CUMULUS FORMING.
&&
.FIRE WEATHER...
ISSUED AT 243 PM CDT WED APR 22 2015
TODAY HAS BEEN MOSTLY A DRYING DAY WEST OF THE MISSISSIPPI RIVER
WHERE MORE SUN HAS OCCURRED...CLOSER TO THE DRIER AIR OVER WESTERN
MN AND WINDS HAVE BEEN GUSTING 30-40 MPH. A WARMER DAY IS EXPECTED
ACROSS THE REGION ON THURSDAY WITH SUNNY SKIES. ADDITIONALLY...THE
DRY AIR OVER WESTERN MN MOVES IN...PLUMMETING RH VALUES TO 20-30
PERCENT. HOWEVER...WINDS DO NOT LOOK NEARLY AS STRONG WITH HIGH
PRESSURE MOVING IN...ONLY IN THE 10 TO 15 MPH RANGE. WITH SOME
GREEN-UP ALREADY OCCURRING AND THE LIGHTER WINDS...HAVE DECLINED
TO CONSIDER ANY FIRE WEATHER HAZARDS AT THIS TIME. SOME RAIN
REMAINS ON TAP TO MOVE INTO THE REGION FOR FRIDAY...ALONG WITH
CLOUDS...WHICH BOTH SHOULD HELP MITIGATE FIRE WEATHER CONCERNS.
LOOKING AHEAD...SUNDAY COULD BE ANOTHER DAY WORTH WATCH FOR FIRE
WEATHER CONCERNS...BUT SIMILAR TO THURSDAY WINDS ARE EXPECTED ON
THE LIGHTER SIDE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR IAZ008-018-019-029.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...SHEA
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1120 AM CDT WED APR 22 2015
.UPDATE...
ISOLATED RAIN SHOWERS AND LIGHT SNOW WILL CONTINUE ACROSS OUR
FORECAST AREA THIS MORNING AND AFTERNOON AS A SFC LOW PRESSURE
SYSTEM SLOWLY MOVES OFF TO THE EAST. STEEP LOW LEVEL LAPSE RATES
ALONG WITH WEAK 850-700 MB FRONTOGENETICAL FORCING WILL HELP
SUPPORT THIS PRECIPITATION. THE 22.14Z HRRR MODEL IS SHOWING
PRECIPITATION TAPERING OFF BY THE EVENING.
NORTHWEST WINDS WILL ALSO BE STRONG THANKS TO A TIGHT SFC PRESSURE
GRADIENT BEHIND THIS LOW...WITH GUSTS NEAR 25 KTS. BOUNDARY LAYER
LOOKS TO MIX DOWN STRONGER WINDS AS RAP BUFKIT SOUNDINGS ARE
SHOWING MIXING UP TO NEAR THE 800 MB LEVEL. WINDS SHOULD WEAKEN BY
THIS EVENING.
&&
.AVIATION/18Z TAFS/...
MAINLY LOW-END VFR CIGS WILL PERSIST INTO THE AFTERNOON AS A
MOSTLY OVERCAST STRATUS DECK WILL STICK AROUND THE AREA. CIGS
WILL MAINLY BE BETWEEN 3.0-5.0 KFT THIS MORNING AND AFTERNOON.
ISOLATED RAIN SHOWERS AND LIGHT SNOW ARE POSSIBLE THROUGH THE
AFTERNOON AS A LOW PRESSURE SYSTEM OVER ONTARIO CANADA WILL SLOWLY
MOVE OUT THIS EVENING. BRIEF MVFR CONDITIONS ARE POSSIBLE IF
PRECIPITATION MOVES OVER THE TAF SITES. CIG HEIGHTS SHOULD IMPROVE
AS SKIES CLEAR TONIGHT. NORTHWEST WINDS WILL BE GUSTY DURING THE
AFTERNOON WITH DECENT BOUNDARY LAYER MIXING UP TO THE 800 MB
LEVEL. GUSTS NEAR 25 KTS POSSIBLE.
&&
.PREV DISCUSSION... /ISSUED 329 AM CDT WED APR 22 2015/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
THE LARGE OCCLUDED LOW PRESSURE AREA OVER THE GREAT LAKES AND
ONTARIO CANADA WILL MOVE LITTLE TODAY. THUS COOL TEMPS AND ISOLD
INSTABILITY RAIN AND SNOW SHOWERS OR FLURRIES WILL CONTINUE. THERE
COULD BE A SLIGHT ENHANCEMENT IN THE PCPN COVERAGE AND INTENSITY
OVER EAST CENTRAL WI THIS AFTERNOON INTO THE EVENING...WHERE A
SFC TROUGH AND SFC-850 MB FRONTOGENESIS WILL BE FOCUSED. OTHERWISE
FCST SOUNDINGS DO SHOW MORE CLEARING TNT WITH LOWS TEMPS IN THE
UPPER 20S TO LOWER 30S.
SHORT TERM...THURSDAY THROUGH FRIDAY NIGHT...FORECAST CONFIDENCE
IS MEDIUM.
MODELS ARE IN GOOD AGREEMENT WITH WEAK HIGH PRESSURE SHIFTING
EASTWARD ACROSS THE REGION THURSDAY AND THURSDAY NIGHT...SLIDING
TO THE EAST FRIDAY MORNING. AREA FORECAST SOUNDINGS SHOW A FAIRLY
DRY AIRMASS IN PLACE OVER THE REGION DURING THIS TIME.
THUS...CONTINUED THE DRY FORECAST FOR THIS PERIOD. COOL
TEMPERATURES WILL CONTINUE DURING THIS PERIOD.
MODELS SEEM TO BE IN BETTER AGREEMENT WITH THE TRACK OF THE LOW
PRESSURE SYSTEM...SHIFTING EASTWARD FROM KANSAS INTO FAR WESTERN
MISSOURI FRIDAY AND FRIDAY NIGHT. 500 MB SHORTWAVE TROUGH SLIDES
EAST SOUTHEAST FROM NEBRASKA INTO SOUTH CENTRAL IOWA FRIDAY INTO
FRIDAY NIGHT...A CONSENSUS TRACK FROM THE MODELS. THIS FEATURE
GETS CLOSE ENOUGH TO THE AREA TO BRING IN THE NORTHERN PORTIONS OF
THE QPF SHIELD FRIDAY NIGHT. THERE IS ALSO SOME LOW TO MID LEVEL Q
VECTOR CONVERGENCE THAT SHIFTS THROUGH THE REGION FRIDAY NIGHT.
AREA FORECAST SOUNDINGS BRING IN DECENT MOISTURE IN THE 650 MB TO
800 MB LAYER FRIDAY NIGHT PER GFS...WITH THE NAM MORE AGGRESSIVE
WITH DEEPER COLUMN MOISTURE. USED CONSENSUS POPS WITH SOME
UNCERTAINTY WITH THE MOISTURE...WITH HIGHEST IN THE SOUTHWEST
PORTIONS OF THE AREA FRIDAY NIGHT. TEMPERATURE PROFILES MAY GET
COLD ENOUGH LATER FRIDAY NIGHT FOR A MIX OF LIGHT RAIN AND LIGHT
SNOW IN NORTHERN AND EASTERN PORTIONS OF THE AREA. COOL
TEMPERATURES WILL CONTINUE FRIDAY INTO FRIDAY NIGHT.
LONG TERM...SATURDAY THROUGH TUESDAY...FORECAST CONFIDENCE IS
MEDIUM.
CONTINUED POPS INTO SATURDAY...AS 500 MB SHORTWAVE TROUGH SLIDES
EAST ACROSS NORTHERN ILLINOIS AND BRINGS LIGHT QPF TO PORTIONS OF
THE AREA. GFS/ECMWF ARE IN DECENT AGREEMENT WITH THIS.
GFS/ECMWF THEN SHOW SOME DIFFERENCES WITH FEATURES SATURDAY NIGHT
INTO SUNDAY NIGHT. THE GFS IS QUICKER WITH BRINGING 500 MB RIDGE
AXIS EAST ACROSS THE REGION THAN THE ECMWF. STILL...BOTH MODELS
SHOW HIGH PRESSURE TO THE NORTH OF THE REGION...KEEPING THE REGION
DRY. THUS...KEPT THE DRY FORECAST GOING FOR THIS PERIOD.
TEMPERATURES SHOULD SLOWLY MODERATE DURING THIS TIME.
GFS THEN BRINGS A STRONG LOW PRESSURE SYSTEM NORTHEAST FROM THE
SOUTHERN PLAINS INTO EAST CENTRAL MISSOURI MONDAY INTO MONDAY
NIGHT...THEN INTO NORTH CENTRAL ILLINOIS TUESDAY. A POTENT 500 MB
SHORTWAVE TROUGH ACCOMPANIES IT...BRINGING QPF TO THE REGION. THE
ECMWF SHOWS NO SUCH FEATURE. FOR NOW...USED CONSENSUS POPS AND
HAVE LOWER END POPS.
AVIATION/12Z TAFS/...
MOSTLY BROKEN STRATOCUMULUS FROM 3.5-5.0 KFT IS EXPECTED TODAY
WITH ISOLD SNOW OR RAIN SHOWERS DUE TO A LARGE AND SLOW MOVING LOW
PRESSURE AREA OVER THE GREAT LAKES AND SRN CANADA. BRIEF PERIODS
OF MVFR CIGS ARE POSSIBLE. ANY SHOWERS MAY BE ASSOCIATED WITH
MVFR CIGS AND VSBYS AS WELL. BRISK AND GUSTY WNWLY WINDS WILL
CONTINUE. FOR TNT...SKIES WILL BECOME MO CLEAR TO PTLY CLOUDY
WITH LESSENING WINDS.
MARINE...
A SMALL CRAFT ADVISORY IS IN EFFECT UNTIL 00Z THU AS BRISK AND
GUSTY WNWLY WINDS CONTINUE AROUND A LARGE AND STRONG LOW PRESSURE
AREA THAT IS OVER THE GREAT LAKES AND SRN CANADA. BY SUNSET...THE
PRESSURE GRADIENT AND MIXING WILL SUBSIDE ENOUGH TO DROP THE WINDS
BELOW SMALL CRAFT ADVISORY CRITERIA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LMZ643>646.
&&
$$
UPDATE...JTS
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
THURSDAY THROUGH TUESDAY...WOOD