Alert archive / Oklahoma / Flash Flood Warnings in 1999

Flash Flood Warning 20, NWS Tulsa, OK

April 24, 1999McIntosh County, Oklahoma

NWS Tulsa, OK issued this flash flood warning at Apr 24, 1999, 5:40 PM CDT for McIntosh County, Oklahoma. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued: Apr 24, 1999, 5:40 PM CDT (22:40 UTC)
Expired: Apr 24, 1999, 8:45 PM CDT
In force: 3 hr
Issued by: NWS Tulsa, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

County McIntosh County, OK

The radar

The Tulsa radar (KINX), 92 km from the middle of the area, began a volume at 22:43 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 10.7 hours before the alert went out and 149 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 17 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 372 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 132 m²/s²
0-3 km storm-relative helicity: 175 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 6.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KTSA 242243
FFWTUL
OKC091-250145-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TULSA OK
540 PM CDT SAT APR 24 1999

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* FLASH FLOOD WARNING FOR
  WESTERN MCINTOSH COUNTY IN OKLAHOMA

* UNTIL 845 PM CDT

* AT 537 PM CDT RADAR INDICATED AN AREA OF VERY HEAVY RAIN ALONG A
  LINE EXTENDING FROM 6 MILES NORTHWEST OF STIDHAM TO 4 MILES 
  NORTH OF RAIFORD TO 10 MILES SOUTHWEST OF RAIFORD..MOVING 
  EAST-NORTHEAST AT 20 MPH.

NWS RADAR INDICATES THAT 1 TO 3 INCHES OF RAINFALL HAS FALLEN ACROSS 
WESTERN PARTS OF MCINTOSH COUNTY. AN ADDITIONAL 1 TO 2 INCHES OF 
RAIN CAN BE EXPECTED ACROSS THESE AREAS THROUGH 845 PM.

STIDHAM...HANNA...VIVIAN...RAIFORD AND CHECOTAH AND ADJACENT 
COMMUNITIES MAY BE AFFECTED BY FLASH FLOODING. 

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER MAY BE TOO DEEP TO ALLOW YOUR CAR TO CROSS SAFELY.
VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY. MOVE TO
HIGHER GROUND.

LAT...LON 3531 9596 3518 9580 3542 9546 3558 9566

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Tulsa, OK wrote its last area forecast discussion before this flash flood warning went out at Apr 24, 3:55 PM CDT, 1 hour 45 minutes earlier.

Area forecast discussion, Apr 24, 3:55 PM CDT, 1 hour 45 minutes before

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
355 PM CDT SAT APR 24 1999

PROBLEM(S) OF THE DAY:
WILL THERE BE HEAVY RAINFALL?
WILL THERE BE SEVERE CONVECTION?

20Z SURFACE ANALYSIS SHOWS FRONT ALONG LA/AR BORDER...TO WEAK FRONTAL
WAVE OVER FAR NE TX...THEN SW THROUGH CNTRL TX.  E-W BAND OF
CONVECTION PERSISTS OVER SE OK-WNCTRL AR ALONG 900MB FRONT WHERE BEST
ELEVATED INSTABILITY WAS LOCATED.  INDIVIDUAL STORMS ARE TRACKING
ENE...BUT VERY LITTLE N/S MOTION WAS NOTED WITH LINE SO EXCESSIVE
RAINFALL SHOULD CONTINUE INTO THE EVENING.

MID-LVL VORT EVIDENT OVER FAR SW TX ON LATEST WV IMAGERY APPEARS TO
BE HANDLED REASONABLY WELL BY 12Z MODELS.  THIS FEATURE IS PROGGD TO
LIFT THROUGH CNTRL/NRN TX THIS EVENING WITH IMPRESSIVE 850-500 MB
OMEGA FIELD SPREADING S TO N THROUGH FORECAST AREA AFTER 06Z.  THIS
LARGE SCALE LIFT COMBINDED WITH STRENGTHENING SLY LLVL JET AND
MOISTURE POOLING (PWS AT OR ABOVE 1.5 INCHES) SHOULD RESULT IN
ADDITIONAL ELEVATED CONVECTION OVERNIGHT...ESPECIALLY AFTER MIDNIGHT
AND PERSISTING INTO SUNDAY MORNING.  MESONET/88D DATA INDICATES THAT
3 TO 5 INCHES OF RAIN HAS FALLEN OVER MUCH OF SE OK/WCNTRL AR...SO
WILL EXTEND FLASH FLOOD WATCH IN THESE AREAS FOR TONIGHT AND TOMORROW
MORNING.  WILL HOLD OFF ON WATCH FOR NRN ZONES...BUT EVENING/MID CREW
WILL NEED TO MONITOR.

CONVECTION SHOULD GRADUALLY SLIDE OFF TO THE E SUN AFTERNOON...AND
SOME AREAS MAY GET A BREAK LATER IN THE DAY.  MEANWHILE...STRONG
SHORTWAVE ROUNDING BASE OF WRN US TROF WILL RESULT IN SURFACE LOW
OVER THE TX PANHANDLE WITH A DRYLINE BECOMING BETTER DEFINED OVER FAR
WRN OK.  FRONT CURRENTLY TO OUR S WILL SLOWLY LIFT N AS WARM
FRONT...AND SHOULD BE POSITIONED ACROSS SRN OK LATE IN THE DAY.  WRN
US TROF WILL EJECT BODILY EWD INTO CNTRL PLAINS LATE SUN/SUN
NGT...PUSHING DRYLINE INTO CNTRL OK OVERNIGHT.  EXPECT CONVECTION TO
FORM ALONG/AHEAD OF DRYLINE OVER WRN OK BY LATE AFTERNOON...WITH
ADDITIONAL THUNDERSTORMS POSSIBLE NEAR THE WARM FRONT.  ACTIVITY MAY
EVENTUALLY DEVELOP INTO A SQUALL LINE AND MOVE THROUGH ERN OK/NW AR
SUN NIGHT/EARLY MON MORNING.

ETA SHOWS DRY SLOT PUNCHING INTO FORECAST AREA BY MONDAY...SO SHOULD
SEE SOME CLEARING AND WARMER TEMPS.

NEXT CHC OF PRECIP ARRIVES LATE WED AND ESPECIALLY THU.

FCSTID = 18
TUL   53  65  59  77 /  70  70  60  30
FSM   60  75  61  78 /  70  70  60  40
MLC   55  73  62  80 /  70  70  60  30
BVO   53  65  57  75 /  60  70  60  30
FYV   58  70  59  76 /  50  70  60  40
IDB   65  84  65  84 /  70  50  50  40
BYV   58  70  59  76 /  50  70  60  40
MIO   56  68  59  76 /  50  70  60  40
MKO   53  65  59  77 /  70  70  60  30
F10   53  65  59  77 /  70  70  60  30
HHW   65  84  65  84 /  70  50  50  40

....
AR...FLASH FLOOD WATCH TONIGHT AND SUNDAY MORNING AR ZNS 19/20/29.
OK...FLASH FLOOD WATCH TONIGHT AND SUNDAY MORNING OK ZNS 71>77/49/53.

--------------------
EXPERIMENTAL OUTPUT:

HAZARDOUS WEATHER EXPECTED NEXT 24 HOURS: SLIGHT CHANCE SEVERE
THUNDERSTORMS/CHANCE OF FLASH FLOODING
NGM CONFIDENCE:  6 ON A SCALE OF 0 TO 10
ETA CONFIDENCE:  7 ON A SCALE OF 0 TO 10
AVN CONFIDENCE:  7 ON A SCALE OF 0 TO 10
FCST CONFIDENCE: 7 ON A SCALE OF 0 TO 10

In the hours before

Special weather statement, Apr 24, 1:00 PM CDT, 4 hours 40 minutes before

ARZ001-002-010-011-019-020-029-OKZ049-053>076-251100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
100 PM CDT SAT APR 24 1999

...FLASH FLOODING WILL BE POSSIBLE THIS AFTERNOON ACROSS SOUTHEAST
OKLAHOMA AND WESTCENTRAL ARKANSAS...
...ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS AFTER MIDNIGHT...
...MORE SEVERE WEATHER EXPECTED SUNDAY AND SUNDAY NIGHT...

.SYNOPSIS...
EARLY THIS AFTERNOON...A STATIONARY FRONT WAS LOCATED FROM SOUTHERN
ARKANSAS ACROSS THE SOUTHEAST CORNER OF OKLAHOMA TO CENTRAL TEXAS. SOUTH
OF THE FRONT...VERY HIGH AMOUNTS OF LOW LEVEL MOISTURE WERE PRESENT.
NORTH OF THE FRONT...SOUTHERLY WINDS ALOFT WERE LIFTING THE WARM HUMID
AIRMASS UP AND OVER THE COOLER AIR...ALLOWING FOR THE FORMATION OF
THUNDERSTORMS THIS MORNING...SOME OF THEM SEVERE WITH VERY HEAVY
RAINFALL. THESE STORMS ARE EXPECTED TO WEAKEN THROUGH THE AFTERNOON AND
DISSIPATE BY THIS EVENING. HOWEVER...REDEVELOPMENT OF THUNDERSTORMS ARE
EXPECTED AFTER MIDNIGHT TONIGHT...SOME OF WHICH COULD BE SEVERE WITH
LOCALLY HEAVY RAINFALL. AS A STRONG UPPER LEVEL DISTURBANCE MOVES OUT OF
THE WESTERN U.S. SUNDAY...SEVERE WEATHER IS AGAIN EXPECTED SUNDAY
AFTERNOON AND NIGHT...MOVING FROM WEST TO EAST ACROSS EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS.

.DISCUSSION...
THUNDERSTORMS HAVE PERSISTED ACROSS SOUTHEAST OKLAHOMA SINCE EARLY THIS
MORNING AND WILL CONTINUE TO PRODUCE HEAVY RAINFALL AND SOME FLOODING
THIS AFTERNOON. RADAR ESTIMATES INDICATE UP TO 4 INCHES OF RAINFALL
ACROSS SOUTHWESTERN PITTSBURG COUNTY WITH OTHER BANDS OF 2 TO 3 INCHES
ACROSS LATIMER...HASKELL...LE FLORE...SEBASTIAN AND SOUTHERN FRANKLIN
COUNTIES. THE PERSISTENT STORMS HAVE STABILIZED THE ATMOSPHERE SOMEWHAT
SO STORMS THIS AFTERNOON ARE NOT LIKELY TO PRODUCE HAIL OR DAMAGING
WINDS. THE STORMS ARE EXPECTED TO DISSIPATE BY EARLY EVENING.

LATER TONIGHT...SOUTHERLY WINDS ALOFT WILL INCREASE AND BRING MOISTURE
INTO THE AREA AGAIN. ELEVATED INSTABILITY WILL INCREASE WITH CAPE VALUES
NEAR 1500 J/KG EXPECTED USING PARCELS LIFTED FROM 5000 FEET. THERE WILL
BE A THREAT OF SEVERE STORMS AFTER MIDNIGHT ACROSS ALL OF EASTERN
OKLAHOMA AND NORTHWEST ARKANSAS WITH LARGE HAIL UP TO 1 INCH IN DIAMETER
AND VERY HEAVY RAINFALL THE PRIMARY THREATS.

ANOTHER ROUND OF MORE SIGNIFICANT SEVERE STORMS WILL BE LIKELY LATE
SUNDAY AFTERNOON AND ESPECIALLY SUNDAY NIGHT. A STRONG UPPER LEVEL
DISTURBANCE WILL LIFT OUT OF THE SOUTHWESTERN U.S. EXPECTED INSTABILITY
AND VERTICAL WIND PROFILES INDICATE THAT SUPERCELL STORMS CAN BE
EXPECTED SUNDAY EVENING.

.EMERGENCY MANAGEMENT AGENCY AND SPOTTER ACTIVATION...
SPOTTER ACTIVATION IS NOT EXPECTED THROUGH TONIGHT HOWEVER...SPOTTERS
AND EMERGENCY MANAGEMENT AGENCIES SHOULD BE PREPARED FOR THE POSSIBILITY
OF SIGNIFICANT SEVERE WEATHER LATE SUNDAY AFTERNOON AND SUNDAY NIGHT.

Special weather statement, Apr 24, 1:31 PM CDT, 4 hours 9 minutes before

ARZ001-002-010-011-019-020-029-OKZ049-053>076-251100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
100 PM CDT SAT APR 24 1999

...FLASH FLOODING WILL BE POSSIBLE THIS AFTERNOON ACROSS SOUTHEAST
OKLAHOMA AND WESTCENTRAL ARKANSAS...
...ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS AFTER MIDNIGHT...
...MORE SEVERE WEATHER EXPECTED SUNDAY AND SUNDAY NIGHT...

.SYNOPSIS...
EARLY THIS AFTERNOON...A STATIONARY FRONT WAS LOCATED FROM SOUTHERN
ARKANSAS ACROSS THE SOUTHEAST CORNER OF OKLAHOMA TO CENTRAL TEXAS. SOUTH
OF THE FRONT...VERY HIGH AMOUNTS OF LOW LEVEL MOISTURE WERE PRESENT.
NORTH OF THE FRONT...SOUTHERLY WINDS ALOFT WERE LIFTING THE WARM HUMID
AIRMASS UP AND OVER THE COOLER AIR...ALLOWING FOR THE FORMATION OF
THUNDERSTORMS THIS MORNING...SOME OF THEM SEVERE WITH VERY HEAVY
RAINFALL. THESE STORMS ARE EXPECTED TO WEAKEN THROUGH THE AFTERNOON AND
DISSIPATE BY THIS EVENING. HOWEVER...REDEVELOPMENT OF THUNDERSTORMS ARE
EXPECTED AFTER MIDNIGHT TONIGHT...SOME OF WHICH COULD BE SEVERE WITH
LOCALLY HEAVY RAINFALL. AS A STRONG UPPER LEVEL DISTURBANCE MOVES OUT OF
THE WESTERN U.S. SUNDAY...SEVERE WEATHER IS AGAIN EXPECTED SUNDAY
AFTERNOON AND NIGHT...MOVING FROM WEST TO EAST ACROSS EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS.

.DISCUSSION...
THUNDERSTORMS HAVE PERSISTED ACROSS SOUTHEAST OKLAHOMA SINCE EARLY THIS
MORNING AND WILL CONTINUE TO PRODUCE HEAVY RAINFALL AND SOME FLOODING
THIS AFTERNOON. RADAR ESTIMATES INDICATE UP TO 4 INCHES OF RAINFALL
ACROSS SOUTHWESTERN PITTSBURG COUNTY WITH OTHER BANDS OF 2 TO 3 INCHES
ACROSS LATIMER...HASKELL...LE FLORE...SEBASTIAN AND SOUTHERN FRANKLIN
COUNTIES. THE PERSISTENT STORMS HAVE STABILIZED THE ATMOSPHERE SOMEWHAT
SO STORMS THIS AFTERNOON ARE NOT LIKELY TO PRODUCE HAIL OR DAMAGING
WINDS. THE STORMS ARE EXPECTED TO DISSIPATE BY EARLY EVENING.

LATER TONIGHT...SOUTHERLY WINDS ALOFT WILL INCREASE AND BRING MOISTURE
INTO THE AREA AGAIN. ELEVATED INSTABILITY WILL INCREASE WITH CAPE VALUES
NEAR 1500 J/KG EXPECTED USING PARCELS LIFTED FROM 5000 FEET. THERE WILL
BE A THREAT OF SEVERE STORMS AFTER MIDNIGHT ACROSS ALL OF EASTERN
OKLAHOMA AND NORTHWEST ARKANSAS WITH LARGE HAIL UP TO 1 INCH IN DIAMETER
AND VERY HEAVY RAINFALL THE PRIMARY THREATS.

ANOTHER ROUND OF MORE SIGNIFICANT SEVERE STORMS WILL BE LIKELY LATE
SUNDAY AFTERNOON AND ESPECIALLY SUNDAY NIGHT. A STRONG UPPER LEVEL
DISTURBANCE WILL LIFT OUT OF THE SOUTHWESTERN U.S. EXPECTED INSTABILITY
AND VERTICAL WIND PROFILES INDICATE THAT SUPERCELL STORMS CAN BE
EXPECTED SUNDAY EVENING.

.EMERGENCY MANAGEMENT AGENCY AND SPOTTER ACTIVATION...
SPOTTER ACTIVATION IS NOT EXPECTED THROUGH TONIGHT HOWEVER...SPOTTERS
AND EMERGENCY MANAGEMENT AGENCIES SHOULD BE PREPARED FOR THE POSSIBILITY
OF SIGNIFICANT SEVERE WEATHER LATE SUNDAY AFTERNOON AND SUNDAY NIGHT.

Local storm report, Apr 24, 3:52 PM CDT, 1 hour 48 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
352 PM CDT SAT APR 24 1999

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

1120 AM    TUSKAHOMA                 OK    .88 INCH HAIL
04/24/99   PUSHMATAHA

0112 PM    MC ALESTER                OK    FLOOD
04/24/99   PITTSBURG                       HIGHWAY PATROL REPORTED
                                           HIGHWAY 31 WEST OF
                                           MCALESTER CLOSED AS
                                           WELL AS HIGHWAY 270
                                           NEAR MCALESTER.

0157 PM    WILBURTON                 OK    .75 INCH HAIL
04/24/99   LATIMER

Local storm report, Apr 24, 3:52 PM CDT, 1 hour 48 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
352 PM CDT SAT APR 24 1999

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

1120 AM    TUSKAHOMA                 OK    .88 INCH HAIL
04/24/99   PUSHMATAHA

0112 PM    MC ALESTER                OK    FLOOD
04/24/99   PITTSBURG                       HIGHWAY PATROL REPORTED
                                           HIGHWAY 31 WEST OF
                                           MCALESTER CLOSED AS
                                           WELL AS HIGHWAY 270
                                           NEAR MCALESTER.

0157 PM    WILBURTON                 OK    .75 INCH HAIL
04/24/99   LATIMER

The office that day

Everything else NWS Tulsa, OK issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 24, 6:35 AM CDT	Severe Thunderstorm Warning	TSA	Pittsburg	40 min
Apr 24, 7:09 AM CDT	Severe Thunderstorm Warning	TSA	Haskell, LeFlore	51 min
Apr 24, 7:14 AM CDT	Severe Thunderstorm Warning	TSA	Pittsburg	61 min
Apr 24, 7:33 AM CDT	Flash Flood Warning	TSA	Pittsburg	117 min
Apr 24, 8:09 AM CDT	Severe Thunderstorm Warning	TSA	Haskell, LeFlore	36 min
Apr 24, 8:13 AM CDT	Severe Thunderstorm Warning	TSA	Pittsburg	47 min
Apr 24, 8:42 AM CDT	Severe Thunderstorm Warning	TSA	LeFlore	63 min
Apr 24, 8:52 AM CDT	Flash Flood Warning	TSA	Haskell, LeFlore	3 hr
Apr 24, 9:32 AM CDT	Severe Thunderstorm Warning	TSA	Latimer, Pushmataha	58 min
Apr 24, 10:36 AM CDT	Flash Flood Warning	TSA	Latimer, Pittsburg, Pushmataha	3 hr
Apr 24, 11:13 AM CDT	Severe Thunderstorm Warning	TSA	LeFlore, Pushmataha	47 min
Apr 24, 11:47 AM CDT	Flash Flood Warning	TSA	LeFlore	118 min
Apr 24, 1:29 PM CDT	Flash Flood Warning	TSA	Latimer, Pittsburg	2 hr
Apr 24, 1:55 PM CDT	Severe Thunderstorm Warning	TSA	Latimer	50 min
Apr 24, 2:59 PM CDT	Severe Thunderstorm Warning	TSA	Haskell, Latimer	31 min
Apr 24, 3:27 PM CDT	Flash Flood Warning	TSA	Latimer, Pittsburg	3 hr

Nearby

Flash Flood Warnings in Oklahoma, 1999 Every flash flood warning in 1999

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.