827
FXUS63 KLBF 182141
AFDLBF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
341 PM CST MON NOV 18 2024
KEY MESSAGES
- PRECIPITATION IN THE FORM OF RAIN WILL CONTINUE THROUGH LATE
THIS EVENING. FOR AREAS EAST OF HIGHWAY 83, ALL RAIN IS
EXPECTED. CLOSER TO THE PINE RIDGE, A TRANSITION TO SNOW IS
LIKELY WITH LITTLE TO NO ACCUMULATIONS EXPECTED.
- THE PATTERN WILL REMAIN CONDUCIVE TO STRONG WINDS EACH DAY
TUESDAY AND WEDNESDAY. THIS WILL COINCIDE WITH AN INFLUX AND
DRY AIR AND THE THREAT FOR ELEVATED TO NEAR-CRITICAL FIRE
WEATHER CONCERNS EACH DAY.
- BROAD UPPER-RIDGING WILL HERALD DRY AND MILD WEATHER FOR DAYS
2-5 (TUESDAY THROUGH FRIDAY) BEFORE THE NEXT DISTURBANCE
APPROACHES FROM THE WEST AND BRINGS LOW-END (< 20%) POPS FOR
MAINLY THE NEBRASKA PANHANDLE.
- SIGNS ARE BEGINNING TO POINT TO A PATTERN FLIP LATE NEXT WEEK
THAT WILL BRING MUCH COLDER TEMPERATURES AND THE POTENTIAL FOR
PRECIPITATION INCLUDING SNOW. THIS HAS THE POTENTIAL TO HAVE
IMPLICATIONS FOR HOLIDAY TRAVELERS AND FOLKS ARE ADVISED TO
CONTINUE MONITORING LATER FORECASTS.
SYNOPSIS
ISSUED AT 340 PM CST MON NOV 18 2024
SATELLITE ANALYSIS SHOWS A MATURING MID-LEVEL CYCLONE LIFTING NORTH
AND EAST ACROSS SOUTH CENTRAL AND EASTERN NEBRASKA. TELL-TALE SIGN
INCLUDES THE COMMA-HEAD APPEARANCE OF UPPER-LEVEL IMAGERY INCLUDING
THE LOW-LEVEL WATER VAPOR BAND. RADAR SHOWS CONSOLIDATING
REFLECTIVITY ACROSS CENTRAL NEBRASKA COINCIDENT WITH THE GREATEST
MID-LEVEL CONVERGENCE WITHIN THE DEFORMATION BAND. MESOANALYSIS
SHOWS RAPID PRESSURE FALLS EAST OF THE TRI-CITIES WHICH LINES UP
WITH THE FORECAST TRACK OF THE PRIMARY SURFACE LOW WHICH IS NOW SUB-
990 HPA OVER NORTH CENTRAL TO NORTHEAST KANSAS. TEMPERATURES RANGE
FROM THE LOW 40S UNDER THE HEAVY PRECIPITATION AT BROKEN BOW UP
THROUGH O'NEILL TO THE MIDDLE 50S FURTHER WEST ACROSS THE SANDHILLS
INTO THE NEBRASKA PANHANDLE.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 340 PM CST MON NOV 18 2024
SATELLITE ANALYSIS SHOWS A MATURING MID-LEVEL CYCLONE LIFTING NORTH
AND EAST ACROSS SOUTH CENTRAL AND EASTERN NEBRASKA. TELL-TALE SIGN
INCLUDES THE COMMA-HEAD APPEARANCE OF UPPER-LEVEL IMAGERY INCLUDING
THE LOW-LEVEL WATER VAPOR BAND. RADAR SHOWS CONSOLIDATING
REFLECTIVITY ACROSS CENTRAL NEBRASKA COINCIDENT WITH THE GREATEST
MID-LEVEL CONVERGENCE WITHIN THE DEFORMATION BAND. MESOANALYSIS
SHOWS RAPID PRESSURE FALLS EAST OF THE TRI-CITIES WHICH LINES UP
WITH THE FORECAST TRACK OF THE PRIMARY SURFACE LOW WHICH IS NOW SUB-
990 HPA OVER NORTH CENTRAL TO NORTHEAST KANSAS. TEMPERATURES RANGE
FROM THE LOW 40S UNDER THE HEAVY PRECIPITATION AT BROKEN BOW UP
THROUGH O'NEILL TO THE MIDDLE 50S FURTHER WEST ACROSS THE SANDHILLS
INTO THE NEBRASKA PANHANDLE.
FOR TONIGHT...THE AFOREMENTIONED SURFACE LOW WILL CONTINUE TO LIFT
NORTH AND EAST ACROSS SOUTH CENTRAL AND EASTERN NEBRASKA. WITH THE
LOCAL AREA SQUARELY IN THE NORTHWEST QUADRANT, MAIN FORCING WILL
CONTINUE TO BE FROM STRONG MID-LEVEL CONVERGENCE ON THE BACKSIDE OF
THE SYSTEM. SHORT-TERM GUIDANCE IS QUICK TO WANE THIS FORCING FOR
ASCENT AS THE EVENING PROGRESSES WITH ESSENTIALLY ALL ASSOCIATED
PRECIPITATION EXPECTED TO WRAP UP AROUND MIDNIGHT. COOLER AIR WILL
QUICKLY FILTER IN BEHIND THIS ACTIVITY BUT THE EXPECTATION FOR AREAS
EAST OF HIGHWAY 83 IS THIS WILL BE DELAYED ENOUGH TO PRECLUDE ANY
CONCERNS FOR A PRECIPITATION TYPE TRANSITION TO ANYTHING OTHER THAN
RAIN. LATER THIS EVENING, A STRONG COLD FRONT WILL DIVE SOUTHEAST
THROUGH THE AREA. RAPID PRESSURE RISES ARE EXPECTED IN THE WAKE OF
THIS FEATURE WITH MAGNITUDES OF UP TO 2-3 HPA/HOUR POSSIBLE. THIS
ALONG WITH AN INCREASE IN CAA AND ALREADY CONSTRICTED PRESSURE
GRADIENT SHOULD YIELD STRONG GUSTY WINDS FOR MUCH OF THE AREA
OVERNIGHT. VARIOUS HIGH RESOLUTION SOLUTIONS, NOTABLY THE HRRR AND
RAP, ADVERTISE A VERY QUICK INCREASE FROM 25-35 MPH GUSTS TO 35-45
MPH GUSTS IN THE POST FRONTAL ENVIRONMENT. WHILE PLAN VIEW MAPS
ADVERTISE GUSTS NEARER TO 50 MPH, NWP PERFORMANCE FOR OVERNIGHT WIND
GUSTS HAS BEEN SUSPECT AT BEST. FURTHER EVALUATION SHOWS LIMITED
SIGNAL FOR > 50 KNOTS (58 MPH) ANYWHERE WITHIN THE LOWEST 2KM OF THE
ATMOSPHERE ACROSS THE FORECAST AREA. UTILIZING PROBABILISTIC DATA,
PROBABILITIES OF EXCEEDING 45 MPH GUSTS ARE MAXIMIZED ACROSS FAR
NORTHERN NEBRASKA IN VICINITY OF VALENTINE WHERE PROBABILITIES
EXCEED 70% WITH GREATER PROBABILITIES IMMEDIATELY NORTH INTO SOUTH
DAKOTA. FURTHER SOUTHWEST, INCREASED SIGNALS ALSO EXIST ACROSS
SOUTHWEST NEBRASKA OUTSIDE OF THE PLATTE VALLEY SYSTEM THOUGH NOT
QUITE AS HIGH PEAKING AROUND 65-70%. THE GOING FORECAST UTILIZED A
BLEND OF 90TH PERCENTILE VALUES ALONG WITH SOME OF THE HIGH
RESOLUTION GUIDANCE NOTED PREVIOUSLY. THIS PRODUCED FAIRLY
WIDESPREAD GUSTS NEARING 40 TO 45 MPH WITH A FEW LOCATIONS AROUND
VALENTINE CLIMBING CLOSER TO 50 MPH. IN-HOUSE TOOLS SUGGEST THIS IS
NEAR THE 50TH PERCENTILE OF NBM GUIDANCE AND WHILE THAT SUGGESTS
INCREASES ARE POSSIBLE, TIMING OF THE PEAK WINDS CASTS SOME DOUBT ON
THE HIGHER VALUES PANNING OUT. WITHIN THE NORTHWESTERLY FLOW BEHIND
THE PASSING FRONT, FLOW IN THE LOW LEVELS WILL DIVERGE AROUND THE
BLACK HILLS BUT PERHAPS YIELD ENOUGH LEE-SIDE CONVERGENCE TO LEAD TO
LOCALIZED PRECIPITATION CHANCES NEARER THE PINE RIDGE. IT'S WORTH
NOTING THAT FEW MODEL SOLUTIONS DEPICT ANY QPF FROM THIS. THAT SAID,
ENOUGH SIGNAL EXISTS TO WARRANT INCLUSION OF SOME LOW-END POPS (<
20%). HREF PROBABILITIES SUGGEST PTYPE FAVORING SNOW AND FORECAST
SOUNDINGS SUPPORT THIS WITH A SHALLOW SATURATED LAYER EXTENDING UP
TO THE DGZ. EVEN THE MOST BULLISH GUIDANCE PAINTS VERY LIGHT QPF AND
SO THE GOING FORECAST IS LITTLE TO NO ACCUMULATIONS EXPECTED WITH
ONLY A COUPLE HOUR WINDOW FOR ANYTHING TO OCCUR. LOW TEMPERATURES
WILL FALL INTO THE MIDDLE 20S WEST TO MIDDLE 30S EAST.
LONG TERM /TUESDAY THROUGH MONDAY/
ISSUED AT 340 PM CST MON NOV 18 2024
TUESDAY AND WEDNESDAY...WHILE THE LOCAL AREA WILL SEE DECREASING
IMPACTS FROM THE MAIN DISTURBANCE TRACKING TO THE EAST, COMBINING
FACTORS WILL STILL SET THE STAGE FOR STRONG WIND GUSTS EACH DAY.
MAIN UPPER-LEVEL LOW WILL CONTINUE TO LIFT NORTHEAST EARLY TUESDAY
BUT WILL GRADUALLY PHASE BACK INTO THE FLOW ALOFT AS ANOTHER
SHORTWAVE TROUGH EJECTS ONTO THE NORTHERN PLAINS. THE MAIN SURFACE
LOW WILL BEGIN TO OCCLUDE ACROSS THE NORTHERN MISSISSIPPI VALLEY,
GRADUALLY LIFTING NORTHWEST INTO SOUTHERN CANADA AS IT DOES. AS THE
AREA BECOMES PINCHED OFF FROM A HIGH PRESSURE WEST OF THE
CONTINENTAL DIVIDE AND THE DEEP LOW TO THE NORTHWEST, STEADY
NORTHWEST WINDS WILL PREVAIL ACROSS THE AREA. MID-LEVEL HEIGHT
CONTOURS WILL RELAX SOME HOWEVER WHICH SHOULD ALLOW FLOW ALOFT TO
WEAKEN. THIS IS ILLUSTRATED BY A NOTABLE DECREASE IN 0-2KM AVERAGE
WINDS WHICH SUBSIDE AFTER DAYBREAK AS IT MOVES NORTH INTO THE
DAKOTAS. THIS IS LIKELY WHAT WILL ALLOW FOR SUB-HEADLINE WINDS (HIGH
WIND WARNING: 58 MPH GUSTS OR GREATER) FROM OCCURRING. STILL,
FORECAST GUSTS OF 35 TO 45 MPH ARE EXPECTED WITH THE STRONGEST OF
THESE VALUES ACROSS THE NORTH. THOUGH DAYTIME TEMPERATURES HAVE
ACTUALLY TRENDED UP, MAXIMUM APPARENT TEMPERATURES WILL STRUGGLE TO
CLIMB OUT OF THE LOW TO MIDDLE 30S. SIMILAR THINKING IS EXPECTED FOR
WEDNESDAY. AS THE DEEP LOW PRESSURE SYSTEM DRIFTS ACROSS SOUTHERN
CANADA, STRONG WEST TO NORTHWESTERLY WINDS WILL AGAIN DEVELOP FOR
MUCH OF THE REGION. A TIGHTENING HEIGHT WILL MAINTAIN STRONG
KINEMATICS ALOFT WITH A STRONG SURGE OF CAA LIKELY WEDNESDAY
MORNING. AS THIS OCCURS, A STRONGER PV ANOMALY WILL BEGIN TO DIVE
EAST-SOUTHEAST GRAZING OUR NORTHERN ZONES EARLY IN THE DAY. THIS
SHOULD ALLOW FOR EFFICIENT DOWNWARD MIXING WHICH SHOULD CRATER DEW
POINT VALUES INTO THE SINGLE DIGITS FOR MUCH OF THE AREA. CASTING
SOME UNCERTAINTY IN PEAK SPEEDS HOWEVER IS HOW QUICKLY THE BOUNDARY
LAYER MIXES AND TAPS INTO THE STRONGER FLOW ALOFT. GIVEN LITTLE TO
NO DECOUPLING EXPECTED TUESDAY NIGHT INTO WEDNESDAY, THE THOUGHT IS
THIS OCCURS QUICKLY AND THE BOUNDARY WILL TAP INTO 50+ KNOT H85 FLOW
BY LATE MORNING. WINDS ALOFT THEN SUBSIDE SO ANY THREAT OF HIGH WIND
WARNING CRITERIA GUSTS SHOULD QUICKLY END. LATEST NBM PROBABILITIES
OF SEEING > 34 KNOT (~39 MPH GUSTS) IS NOW HIGHER FOR TUESDAY THAN
WEDNESDAY SO THIS SUPPORTS LATEST THINKING THAT THE WINDOW WILL BE
QUITE SHORT LIVED ON WEDNESDAY AND LIMITS CONFIDENCE ENOUGH TO
PRECLUDE HEADLINES. WITH HIGH TEMPERATURES IN THE MIDDLE TO UPPER
40S EACH DAY, AFTERNOON HUMIDITY MINIMUMS ARE LIKELY TO FALL INTO
THE 20S AND POSSIBLY EVEN THE UPPER TEENS RESPECTIVELY TUESDAY AND
WEDNESDAY. THIS WILL LEAD TO ELEVATED TO NEAR-CRITICAL FIRE WEATHER
CONCERNS WITH MORE WEIGHT GIVEN TO THE EXPECTED WINDS. THE LATEST
SPC OUTLOOK HAS INTRODUCED A DAY 2 ELEVATED CONCERN FOR MAINLY THE
WESTERN ZONES WITH MENTION THAT LATER OUTLOOKS FOR WEDNESDAY MAY
NEED SIMILAR. AM IN AGREEMENT WITH THIS AS ANY FIRE START WILL
LIKELY BECOME DIFFICULT TO CONTAIN IN THE EXPECTED STRONG WINDS.
THURSDAY AND BEYOND...THE EXTENDED FORECAST CALLS FOR A CONTINUATION
OF MOSTLY IF NOT ENTIRELY DRY WEATHER AND ABNORMALLY WARM
TEMPERATURES. THIS IS LARGELY DUE TO THE RETURN OF INCREASING MID-
LEVEL RIDGING EXPECTED TO DEVELOP DURING THE TIME FRAME. BY
SATURDAY, NWP GUIDANCE IS IN GOOD AGREEMENT PLACING THE RIDGE AXIS
ALONG THE SPINE OF THE CENTRAL ROCKIES AND MODEST NORTHWESTERLY FLOW
LOCALLY IN THE DOWNSTREAM FLOW. THE NEXT DISTURBANCE MOVING THROUGH
WESTERN CONUS WILL KICK THIS RIDGE THROUGH THE AREA OVER THE
WEEKEND. TEMPERATURES WILL GRADUALLY FALL TO MORE SEASONABLE VALUES
BY EARLY NEXT WEEK. THE MODEL BLEND HAS INTRODUCED SLIGHT CHANCE (<
20%) POPS FOR OUR FAR NORTHWEST ZONES SUNDAY NIGHT INTO EARLY
MONDAY. THIS IS THE LONE EXCEPTION TO THE DRY FORECAST THROUGH DAY
7. WHILE THE NBM PROBABILITIES SUPPORT THIS, GEFS/EPS PROBABILITIES
ARE SORELY LACKING SO CONFIDENCE IS LOW. EITHER WAY, LITTLE TO NO
IMPACTS ARE EXPECTED. HEADING INTO THE MIDDLE TO LATTER HALF OF NEXT
WEEK, A PATTERN CHANGE APPEARS LIKELY. EPS/GEFS SUGGEST INCREASING
RIDGING OVER ALASKA/GULF OF ALASKA. THIS WILL ALLOW FOR COLDER AIR
TO SPILL SOUTH ACROSS CANADA AND INTO CONUS JUST IN TIME FOR THE
THANKSGIVING TRAVEL WINDOW. BOTH EPS/GEFS SHOWCASE NEGATIVE
ANOMALIES FOR TEMPERATURES OVER MUCH OF THE ROCKIES AND SPILLING
SOUTH ONTO PORTIONS OF THE PLAINS. VARIABILITY WITHIN EACH ENSEMBLE
SUITE REMAINS FAIRLY HIGH, HOWEVER, WITH INNER-QUARTILE SPREADS
APPROACHING 20 DEGF. THAT SAID, THERE APPEARS TO BE A LEFT SKEW
WITHIN THE DATA TOWARDS THE END OF THE MONTH SUGGESTING MORE
GUIDANCE SUPPORTS COLDER TEMPERATURES THAN THE OPPOSITE. THIS WILL
BEAR WATCHING FOR FOLKS WITH TRAVEL PLANS FOR THE HOLIDAY AS THE
COLDER TEMPERATURES WILL BE FAVORABLE FOR WINTRY WEATHER, EVEN
DURING THE DAYTIME. THE LATEST CPC OUTLOOK IS CATCHING ONTO THIS
TREND WITH BELOW NORMAL TEMPERATURES AND ABOVE NORMAL PRECIPITATION
FAVORED IN BOTH THE 6-10 AND 8-14 DAY OUTLOOKS SO STAY TUNED.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1215 PM CST MON NOV 18 2024
THERE WILL BE A TIGHT WEST TO EAST GRADIENT IN CONDITIONS ACROSS
CENTRAL AND WESTERN NEBRASKA THROUGH THE FIRST PART OF THE VALID
PERIOD. LOW PRESSURE MOVING UP FORM THE SOUTH WILL PUSH RAIN AND
SUB-VFR CONDITIONS UP THROUGH EASTERN NEBRASKA PRIMARILY EAST
OF HWY 83 WITH DRY VFR CONDITIONS TO THE WEST. TAF SITES WILL BE
ON THE DIVIDING LINE BUT ANTICIPATE VFR WILL HOLD, THOUGH WILL
USE VCSH AT KLBF WHERE PRECIPITATION WILL BE CLOSE TO THE
AIRFIELD.
AS THE LOW PULLS OFF TO THE NORTH TONIGHT EXPECT STRONG GUSTY
WINDS WILL SURGE IN FROM THE WEST WITH GUSTS GENERALLY AROUND
35KT AT KLBF AND AROUND 40KT AT KVTN. SINCE HAVE ROBUST WIND
GUSTS AT THE SURFACE IN THE TAFS WILL NOT INCLUDE A MENTION OF
LOW LEVEL WIND SHEAR AS ANTICIPATE WINDS ALOFT WILL BE AT OR
BELOW 50KT ABOVE TAF SITES, THOUGH STILL EXPECT IT WILL BE QUITE
A BUMPY RIDE. GUSTS WILL DIMINISH A BIT AROUND DAYBREAK BUT
WILL RAMP UP AGAIN TOWARD THE END OF THE VALID PERIOD AS DIURNAL
HEATING MIXES THE BOUNDARY LAYER. ALSO EXPECT A SUB-VFR CIG AT
KVTN AS THE WINDS ARRIVE WITH PROBABILISTIC GUIDANCE SHOWING A
BETTER THAN EVEN CHANCE FOR A PERIOD OF CIGS AT OR BELOW 3KFT
BEFORE DAYBREAK.
LBF WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...NMJ
SHORT TERM...NMJ
LONG TERM...NMJ
AVIATION...MBS
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