As of 4:00 PM CDT, a significant flash flooding event is unfolding across parts of Arkansas, Kansas, Oklahoma, and Texas. The latest forecast discussion from the Tulsa National Weather Service (NWS) underscores this point and doesn’t mince words as to the significant dangers.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
337 PM CDT SAT MAY 23 2015 .
…LIFE THREATENING FLOOD POTENTIAL TONIGHT THROUGH SUNDAY…
WIDESPREAD CONVECTION IS UNDERWAY ACROSS THE CENTRAL AND SOUTHERN PLAINS WITHIN AN EXPANDING PLUME OF TROPICAL MOISTURE. OBSERVED RAINFALL RATES HAVE BEEN IMPRESSIVE ESPECIALLY FOR AREAS BENEATH ANY CONVECTIVE SEGMENT THAT BECOMES ORIENTATED PERPENDICULAR TO THE LOW LEVEL SOUTHERLY FLOW. FLOW ALOFT WILL CONTINUE TO BACK AS UPPER TROUGH APPROACHES WHILE DIFFLUENT REGION GRADUALLY SPREADS EASTWARD. THIS WILL ALLOW THE ONGOING CONVECTION TO EXPAND IN COVERAGE FROM WEST TX NORTHWARD INTO CENTRAL AND EASTERN OK THIS EVENING AND OVERNIGHT. RAINFALL FORECASTS MAY BE CONSERVATIVE BASED ON OBSERVED CONDITIONS THIS AFTERNOON…AND LATER UPDATES MAY NEED TO INCREASE TOTALS A BIT FURTHER ESPECIALLY FROM LATE TONIGHT THROUGH SUNDAY MORNING ACROSS EASTERN OKLAHOMA.
IMPACT: WET SOILS ALONG WITH MANY LARGER RIVERS NEAR OR CURRENTLY IN FLOOD STAGE WILL ALLOW FOR RAPID ONSET OF FLASH FLOODING. EVEN THE CONSERVATIVE RAINFALL TOTALS WILL PRODUCE LIFE AND PROPERTY THREATENING FLOODING. THE RAINFALL AXIS WILL SHIFT EASTWARD SUNDAY AFTERNOON / OVERNIGHT AND IMPACT WESTERN ARKANSAS. WHILE THE RAINFALL TOTALS MAY TAPER A BIT AS THE UPPER FORCING REMAINS LESS…THE SATURATED CONDITIONS WILL MAINTAIN THE POTENTIAL FOR DANGEROUS FLOODING. OF ADDITIONAL CONCERN WILL BE MONDAY NIGHT INTO TUESDAY AS A LARGE COMPLEX OF STORMS ORIGINATES ACROSS WESTERN TX AND SPREADS NORTHEASTWARD. WHILE THE BULK OF THIS RAINFALL IS CURRENTLY FORECAST NEAR THE ARKLATEX REGION…HEALTHY RAINFALL TOTALS ARE LIKELY TO SPREAD INTO SE OK AND WEST CENTRAL ARKANSAS WHICH WILL QUICKLY WORSEN ANY ONGOING FLOOD CONDITIONS. A LULL IN CONVECTIVE COVERAGE IS EXPECTED FOR THE MID WEEK PERIOD BEFORE A COLD FRONT AND UPPER WAVE IMPACT THE REGION BY LATE NEXT WEEK WITH MORE WIDESPREAD RAINFALL POSSIBLE.
Though rather technical in nature, the basic message behind the forecast discussion is quite simple. Over a vast area of the southern plains, a significant and potentially life-threatening flash flooding potential exists. As a result, the Tulsa NWS has also issued a Flash Flood Watch.
NATIONAL WEATHER SERVICE TULSA OK
355 PM CDT SAT MAY 23 2015
PUSHMATAHA-CHOCTAW-OSAGE-WASHINGTON OK-NOWATA-CRAIG-OTTAWA-PAWNEE- TULSA-ROGERS-MAYES-DELAWARE-CREEK-OKFUSKEE-OKMULGEE-WAGONER- CHEROKEE-ADAIR-MUSKOGEE-MCINTOSH-SEQUOYAH-PITTSBURG-HASKELL- LATIMER-LE FLORE- INCLUDING THE CITIES OF…ANTLERS…CLAYTON…HUGO…PAWHUSKA… BARTLESVILLE…NOWATA…VINITA…MIAMI…PAWNEE…TULSA… CLAREMORE…PRYOR…JAY…BRISTOW…OKEMAH…OKMULGEE…WAGONER… TAHLEQUAH…STILWELL…MUSKOGEE…EUFAULA…SALLISAW… MCALESTER…STIGLER…WILBURTON…POTEAU
355 PM CDT SAT MAY 23 2015
…FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH MONDAY MORNING…
…LIFE AND PROPERTY THREATENING FLOODING EVENT UNDERWAY…
THE FLASH FLOOD WATCH CONTINUES FOR
* PORTIONS OF EAST CENTRAL OKLAHOMA…NORTHEAST OKLAHOMA AND SOUTHEAST OKLAHOMA…INCLUDING THE FOLLOWING AREAS…IN EAST CENTRAL OKLAHOMA…CHEROKEE…MUSKOGEE…OKFUSKEE AND SEQUOYAH. IN NORTHEAST OKLAHOMA…ADAIR…CRAIG…CREEK… DELAWARE…MAYES…NOWATA…OKMULGEE…OSAGE…OTTAWA… PAWNEE…ROGERS…TULSA…WAGONER AND WASHINGTON. IN SOUTHEAST OKLAHOMA…CHOCTAW…HASKELL…LATIMER…LE FLORE…MCINTOSH… PITTSBURG AND PUSHMATAHA.
* THROUGH MONDAY MORNING
* WIDESPREAD SHOWERS AND THUNDERSTORMS WILL OVERSPREAD MUCH OF EASTERN OKLAHOMA TONIGHT…AND SPREAD EASTWARD INTO WESTERN ARKANSAS DURING THE DAY ON SUNDAY. RAINFALL RATES OF 1 TO 2 INCHES PER HOUR WILL BE COMMON WITH THE HEAVIEST RAINS.
* WIDESPREAD RAINFALL TOTALS OF 3 TO 6 INCHES ARE EXPECTED ACROSS MUCH OF EASTERN OKLAHOMA…ESPECIALLY AREAS ALONG AND WEST OF A LINE FROM MIAMI OKLAHOMA TO HUGO OKLAHOMA. LOCAL AMOUNTS OF 8 TO 9 INCHES WILL BE POSSIBLE WITHIN THIS SAME AREA.
LIFE THREATENING FLOODING CAN QUICKLY DEVELOP WITH THESE RAINFALL AMOUNTS…ESPECIALLY NEAR AREA RIVERS AND LAKES. BE PREPARED TO ACT QUICKLY SHOULD WARNINGS BE ISSUED FOR YOUR AREA.
DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVERS THE ROAD TO UNKNOWN DEPTHS. TAKE A DIFFERENT ROUTE TO REACH YOUR DESTINATION OR WAIT UNTIL THE WATER RECEDES.
IF YOU ARE IN THE WATCH AREA…KEEP INFORMED…AND BE READY FOR QUICK ACTION IF FLASH FLOODING IS OBSERVED OR IF A WARNING IS ISSUED. HAVE A MEANS OF RECEIVING ANY WARNINGS ISSUED OVERNIGHT SUCH AS A WEATHER RADIO.
For many parts of Arkansas, Kansas, and Texas, the flooding threat is just as significant. The latest information from your local NWS office can be obtained by NOAA weather radio or clicking your locale on this map which will take you directly to your NWS office. Obviously, the weather media (local and national) outlets of your choice have excellent information as well. Most of the flooding will take place in the Arkansas/Red Basin region. The West Gulf region is also expecting major flooding as well.
Here’s some important flash flooding safety information from the NWS. Remember, Turn Around, Don’t Drown. More people are killed every year from flooding than all other weather hazards combined. Last but not least, here’s some helpful disaster supply kit information from Ready.gov.
Stay safe and stay very weather aware during this event. With knowledge being power, you have all the information at your fingertips to keep you and your loved ones safe.
For the sake of brevity, I’ll keep this short, sweet, and to the point. We’ve an active severe weather period across the Great Plains that, at this time, includes the threat for severe weather from today (Wednesday) through at least Sunday. This has been well forecast several days in advance by the Storm Prediction Center (SPC) and local National Weather Service (NWS) offices. Tuesday, 5 May 2015 was quite an active severe weather day with tornadoes in New Mexico and Texas along with scattered wind damage reports as far northeast as the Tulsa metro.
TUESDAY: 5 MAY 2015
Today’s severe weather scenario is a very complex and challenging one for forecasters. A Tornado Watch will be issued in short order for parts of Kansas, Nebraska, Oklahoma, and Texas. The bottom line is simply this: if and when storms do form, they will likely be severe. Not all areas in the Slight or Enhanced Risk areas will see severe weather. Here’s a look at the overall Storm Prediction Center severe weather outlook.
STORM PREDICTION CENTER CATEGORICAL OUTLOOK FOR WEDNESDAY, 6 MAY 2015 (11:30 AM CDT)
Two separate Enhanced Risk areas have been included within the Slight Risk area for parts of northwest Texas into southwestern Oklahoma and much of central Kansas into south-central Nebraska. These are the areas where the Storm Prediction Center feels the most significant severe weather events will take place. The gap between them over northwestern Oklahoma has some uncertainty at this time…but that could change with the mid afternoon or evening outlooks. Now, let’s take a look at today’s tornado threat.
SPC DAY ONE TORNADO OUTLOOK 6 MAY 2015 (11:30 AM CDT)
As was the case with Tuesday, much of the Slight Risk area is covered with a 2% and 5% tornado threat. A 10% area has been incuded for much of central KS into south-central NE. In addition, a “hatched” area (outlined in black and filled with black dashes) covers the 10% area as well. This is to cover the probability of a few tornadoes (hopefully very few) that are of EF-2 to EF-5 intensity within twenty-five miles of a given point within the hatched area. There’s no reason to panic or fall victim to fear mongers, but folks living anywhere in the tornado threat area, especially for parts of Kansas and Nebraska, need to pay extra close attention to watch and warming information and plan accordingly.
SPC DAY ONE WIND OUTLOOK 6 MAY 2015 (11:30 AM CDT)
Let’s take a quick look at the severe weather wind threat. As expected, the highest probabilities for strong, damaging straight-line winds are over parts of Kansas and Nebraska. The threat extends well into much of Oklahoma and central Texas. This coves the possibilities of damaging winds of 60 mph or higher with any storms. Straight line winds, especially those associated with downbursts or microbursts can be intense enough that people will report a tornado in progress. The challenge with damaging straight line winds is the possibility that, especially over densely populated areas, thousands of people can lose electrical power, etc. over a wide swath in addition to damage to roofs, siding, fences, and even vehicles hit by flying debris. It’s safe to say that any storm that is considered severe today and tonight by your local NWS office carries this threat.
DAY ONE HAIL OUTLOOK 6 MAY 2015 (11:30 AM CDT)
Today’s hail outlook from SPC covers a larger area than the two previous threats. All of the Enhanced Risk areas and much of the Slight Risk is covered by a hatched area with a threat of hail of two inches in diameter and larger within twenty-five miles of any given point. Within the 30% areas, the chances are close to one in three that this will occur. While much of the focus today will be on the tornado threat in Kansas and Nebraska, keep in mind that hail events cover a very wide area and it’s important to keep this in mind if you are in a warned area. Today will be an active severe weather day across the southern and central Great Plains with numerous severe storms expected. Keep in touch with your local NWS office and the SPC and the media outlets of your choice for the latest updates as this setup will evolve throughout the day. Of course, never forget your NOAA weather radio. I’d be remiss to not mention the threat for flash flooding. This will be possible with any storms, even some that are non-severe.
In summary, tornado watches are forthcoming from the SPC for parts of Kansas, Nebraska, Oklahoma, and Texas this afternoon and evening. Stay very weather aware with at least three reliable sources of watch and warning information close at hand and plan your day accordingly. There’s no need for panic or unnecessary worrying (that’s all to often fostered by fear mongers on social media…hence the importance of you getting your watch and warning information from official sources), but do keep abreast of the situation since it will unfold hour by hour and changes are inevitable, especially once storms commence. Tomorrow morning, we’ll take a look at the rest of the week…but now, let’s get today out of the way. Stay safe and weather aware!