058
FXUS63 KIND 182347
AFDIND
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
647 PM EST MON NOV 18 2024
KEY MESSAGES
- RAIN TONIGHT ALONG WITH GUSTS 25 TO 35 MPH
- RAIN ENDS TUESDAY MORNING, THEN A WARM AND DRY AFTERNOON
- MUCH COLDER WEATHER WEDNESDAY NIGHT THROUGH SATURDAY WITH SNOW
LIKELY NORTHEAST OF INDIANAPOLIS, LITTLE TO NO ACCUMULATIONS
- BREEZY WEDNESDAY AND THURSDAY AFTERNOONS WITH GUSTS OF 25-35 MPH
SHORT TERM (THIS EVENING THROUGH TUESDAY)
ISSUED AT 236 PM EST MON NOV 18 2024
INITIAL ROUND OF ISENTROPIC LIFT WILL CONTINUE TO PUSH NORTH THIS
AFTERNOON, TAKING THE RAIN WITH IT. WILL KEEP SOME POPS AS NEEDED IN
THE NORTH FOR THE REMAINDER OF THE AFTERNOON, DIMINISHING WITH TIME.
SATELLITE SHOWS SOME BREAKS IN THE CLOUDS HAVE DEVELOPED SOUTH OF
THE AREA, AND THESE WILL MOVE INTO AT LEAST THE SOUTHERN AREA. THIS
SUNSHINE PLUS CONTINUED WARM ADVECTION WILL KEEP TEMPERATURES WARM
THIS AFTERNOON.
CENTRAL INDIANA WILL BE IN A LULL BETWEEN AREAS OF FORCING THIS
EVENING, SO WILL GO DRY DURING THE EVENING HOURS. OVERNIGHT THE WARM
CONVEYOR BELT WILL MOVE INTO THE AREA. 850MB WINDS OF 50-60KT WILL
BRING IN PLENTIFUL MOISTURE. A POTENT SYSTEM MOVING INTO THE UPPER
MISSISSIPPI VALLEY WILL PROVIDE GOOD FORCING TO INTERACT WITH THIS
MOISTURE. THUS, EXPECT SOME RAIN TO FALL ACROSS THE AREA FROM WEST
TO EAST DURING THE NIGHT. WILL GO HIGH POPS ALL AREAS.
GIVEN THE STRONG WINDS ALOFT AND LITTLE OR NO INVERSION BELOW, SOME
GUSTS WILL OCCUR AT THE SURFACE. HI-RES MODELS LOOK TO BE OVERDOING
GUSTS AS USUAL (SHOWING 50 MPH GUSTS), BUT ENSEMBLES DO SHOW PEAK
WINDS NEARING 40 MPH IN THE WESTERN FORECAST AREA TONIGHT.
CONVECTION WILL BE POSSIBLE BUT NOT DEEP OR WIDESPREAD GIVEN VERY
LOW INSTABILITY EXPECTED.
GIVEN THE LACK OF NOTABLE CONVECTION, THE LOWER PEAK GUSTS OF THE
ENSEMBLES SEEM MORE REASONABLE. STRONGEST GUSTS WILL BE ACROSS THE
WESTERN FORECAST AREA WHERE THE STRONGER WINDS ALOFT WILL BE.
WITH THE SURFACE COLD FRONT REMAINING WEST OF THE AREA TONIGHT, LOWS
WILL BE VERY WARM FOR THIS TIME OF NOVEMBER, WITH LOWS IN THE MIDDLE
50S TO NEAR 60. RECORD HIGH MINIMUMS FOR NOVEMBER 19 WILL NOT BE IN
JEOPARDY THOUGH AS COLDER AIR WILL MOVE DURING THE EVENING HOURS OF
TUESDAY.
SOME RAIN MAY LINGER EARLY TUESDAY BEFORE DRIER AIR MOVES IN ALOFT,
SO WILL KEEP SOME LOW POPS EARLY, DIMINISHING AS THE MORNING
PROGRESSES. SOME DRYING WILL OCCUR IN THE LOWER LEVELS, BUT THERE IS
A CONCERN OF SOME LOWER CLOUDS REDEVELOPING NORTH WITH SOME COLDER
AIR ALOFT MOVING IN. WILL KEEP SKIES PARTLY CLOUDY NORTH GIVEN THIS
POSSIBILITY.
WITH COLDER AIR AT THE SURFACE HOLDING BACK UNTIL LATER IN THE DAY,
TEMPERATURES ON TUESDAY WILL BE WARM AGAIN, WITH HIGHS IN THE MIDDLE
TO UPPER 60S EXPECTED.
LONG TERM (TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 236 PM EST MON NOV 18 2024
TUESDAY NIGHT THROUGH THURSDAY.
BY TUESDAY NIGHT THE LOW PRESSURE SYSTEM THAT WILL BRING WIDESPREAD
RAIN TO INDIANA TONIGHT WILL HAVE FULLY OCCLUDED AS IT CONTINUES TO
TRACK NORTH INTO CANADA. THE VORT MAX ASSOCIATED WITH THE OCCLUDED
LOW WILL QUICKLY GET INGESTED INTO THE JET STREAM AND BEGIN TO SHIFT
BACK SOUTHEASTWARDS. THE TRACK OF THE SURFACE LOW ASSOCIATED WITH
THE UPPER LEVEL SYSTEM CONTINUES TO SLOWLY TREND NORTHEASTWARD WITH
ENSEMBLES NOW CLUSTERING ON A SLIGHTLY WEAKER AND MORE NORTHEASTERLY
TRACK WHICH WAS THE OUTLIER THIS TIME YESTERDAY.
STRONGER CYCLOGENESIS IS EXPECTED TO KICK OFF WEDNESDAY INTO
WEDNESDAY NIGHT ACROSS MICHIGAN WITH A RAPIDLY STRENGTHENING LLJ
SOUTHWEST OF THE PARENT LOW PRESSURE SYSTEM. RAINFALL LOOKS LIKELY
ACROSS THE NORTHEASTERN COUNTIES WEDNESDAY AFTERNOON IN RESPONSE TO
THIS STRENGTHENING LLJ WITH MORE WIDESPREAD PRECIPITATION WEDNESDAY
NIGHT INTO THURSDAY ON THE BACKEND OF THE SYSTEM AS THE LOW
CONTINUES TO DEEPEN AND ANOTHER JET STREAK IN THE MID LEVELS PUSHES
SOUTHWARD. THESE MINOR CHANGES IN THE FORECAST TRACK AND STRENGTH
ARE ALSO CREATING A TIGHTER GRADIENT ON WHERE PRECIPITATION IS
EXPECTED TO FALL GOING INTO THURSDAY WITH THE POTENTIAL THAT SPOTS
NEAR AND SOUTHWEST OF INDIANAPOLIS ONLY SEE FLURRIES WHILE AREAS TO
THE NORTHEAST SEE SNOW SHOWERS. SURFACE TEMPERATURES WEDNESDAY NIGHT
INTO THURSDAY WILL BE MARGINAL AT BEST WHICH COMBINED WITH THE VERY
WARM GROUND TEMPS SHOULD ANY SNOW ACCUMULATIONS, BUT WITH DECENT
NEAR SURFACE LAPSE RATES THERE MAY BE SHORT PERIODS WHERE SNOWFALL
RATES MAY OVERCOME THE WARMER TEMPERATURES.
WIND CHILLS THURSDAY MAY DROP INTO THE UPPER TEENS WITH THE
COMBINATION OF WIND GUSTS TO 35 MPH AND TEMPERATURES IN THE 30S
WHICH WILL FEEL EVEN COLDER WITH THE RECENT WARMNESS.
FRIDAY THROUGH MONDAY.
LAKE ENHANCED MOISTURE WILL CONTINUE TO STREAM INTO THE NORTHEASTERN
COUNTIES FRIDAY INTO SATURDAY WHICH MAY BRING ADDITIONAL CHANCES FOR
LIGHT SNOW ALONG WITH WIDESPREAD COLDER THAN NORMAL CONDITIONS
ACROSS ALL OF CENTRAL INDIANA INTO THE EARLY WEEKEND. CONDITIONS
WILL REMAIN BREEZY FRIDAY AFTERNOON AS PRESSURE GRADIENTS REMAIN
TIGHT. BY SUNDAY THE FLOW WILL BECOME MORE ZONAL WHICH WILL FAVOR
THE CLEARING OUT OF THE NEAR SURFACE STRATUS AND GRADUALLY WARMING
TEMPERATURES.
FORECAST CONFIDENCE QUICKLY FALLS OF SUNDAY INTO MONDAY WITH MAJOR
DIFFERENCES IN DETERMINISTIC MODELS AND A WIDE SPREAD IN ENSEMBLE
SPAGHETTI PLOTS AS MODELS STRUGGLE IN HANDLING A CLIPPER SYSTEM
ACROSS CANADA AND HOW IT WILL INTERACT WITH A BROAD RIDGE OF HIGH
PRESSURE ACROSS THE APPALACHIANS. THERE ARE SOME SIGNS THAT THE
CLIPPER SYSTEM WILL BE STRONG ENOUGH TO PUSH INTO THE OHIO VALLEY
WHICH WOULD BRING A COLD FRONT AND A RETURN TO RAIN CHANCES, BUT
CONFIDENCE IS LOW AT THIS POINT. WHERE CONFIDENCE IS HIGHER IS THAT
TEMPERATURES WILL GRADUALLY WARM SUNDAY INTO MONDAY WITH A RETURN IN
ABOVE NORMAL HIGHS AND LOWS.
AVIATION (00Z TAF ISSUANCE)
ISSUED AT 647 PM EST MON NOV 18 2024
IMPACTS:
- SURFACE WINDS INCREASING OVERNIGHT FROM THE SOUTHEAST, GUSTS NEAR
20 KT POSSIBLE.
- LOW-LEVEL WIND SHEAR 40-45KT OVERNIGHT THROUGH ABOUT 10Z-12Z.
- RAIN DEVELOPING AROUND 06Z, CONTINUING INTERMITTENTLY THROUGH
ABOUT 14Z, MVFR/IFR POSSIBLE.
- DIMINISHING WINDS AND CLOUDS AFTER 18Z.
DISCUSSION:
A POTENT STORM SYSTEM IS CURRENTLY APPROACHING INDIANA, AND WILL
BRING RAIN AND WIND TO ALL TERMINALS OVERNIGHT.
AT THE SURFACE, STRENGTHENING PRESSURE GRADIENT WILL LEAD TO
INCREASING SOUTHEASTERLY WINDS BETWEEN 10-15KT WITH GUSTS NEAR 20KT.
A FEW GUSTS TO AROUND 25KT ARE POSSIBLE BY MORNING.
JUST OFF THE SURFACE, A STRONG LOW-LEVEL JET ABOVE A SHALLOW
INVERSION WILL ALLOW FOR SOME LOW-LEVEL WIND SHEAR AROUND 2000FT
AGL, BETWEEN 40-45 KT ON AVERAGE.
RAIN ARRIVES AROUND 06Z, CONTINUING ON AN OFF THROUGH 14Z. THOUGH
THUNDERSTORMS SHOULD NOT BE COMMON, A RUMBLE OF THUNDER CANNOT BE
RULED OUT. RAIN MAY LEAD TO MVFR CONDITIONS, WITH ISOLATED IFR
POSSIBLE IN HEAVIER SHOWERS.
THE SYSTEM'S COLD FRONT SWINGS THROUGH TUESDAY MORNING WITH
SOUTHWESTERLY WINDS BEHIND IT. EXPECT DIMINISHING WINDS THEREAFTER
ALONG WITH DECREASING CLOUD COVER. CLOUD COVER AHEAD OF THE FRONT
MAY BECOME MVFR AT TIMES.
IND WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...50
LONG TERM...WHITE
AVIATION...ECKHOFF
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