September 2023 seems to have the potential to be one of the ten hottest Septembers in OKC history. The current ten hottest are as follows:

1) 1931 - 93.5/70.9
2) 1998 - 92.9/69.5
3) 1939 - 93.6/66.9
4) 1911 - 90.8/69.2
5) 1978 - 90.7/68.7
6) 1954 - 93.1/64.9
7) 2019 - 88.8/68.8
8) 1933 - 88.6/68.5
9) 1947 - 89.9/66.4
10) 1921 - 88.5/67.6

^ I agree. I mentioned several posts back in August thread that I see us making a run at some record highs in OKC coming up. There will be some fronts that swing through and "cool" us down temporarily, but with no meaningful moisture in 50+ days, the drought is going to continue to let air temps climb during the day. Only 4 times in the last two decades has OKC set or tied a record high in September.

Here is record highs each day for OKC in September for us to keep track:


September 1 106 2000
September 2 108 1939, 2000
September 3 108 2000
September 4 107 1998
September 5 106 1913, 1998
September 6 105 1936
September 7 105 1907, 1936, 2012
September 8 102 1896
September 9 102 1896, 1930
September 10 102 1930
September 11 105 2000
September 12 102 1895
September 13 102 1965, 2011
September 14 102 1965
September 15 101 1895
September 16 103 1896
September 17 104 1896
September 18 100 1896
September 19 98 1954
September 20 100 1954
September 21 97 1956, 1980, 1998, 2022
September 22 98 1921
September 23 96 1931, 1938
September 24 98 1898, 1938
September 25 99 1898
September 26 99 1898
September 27 99 1898
September 28 103 1953
September 29 98 1953
September 30 100 1977

Models are showing decent rain chances across the state next Wed/Thurs as a front stalls. Not big rains but any kind of moisture will be welcome.

We'd better get some rain before we head into the windy fall months.

We'd better get some rain before we head into the windy fall months.

Luckily September/October are historically the 3rd and 4th wettest months. You definitely don't want to be in drought heading into December-February

https://weather-and-climate.com/uploads/average-rainfall-united-states-of-america-oklahoma-city.png

Models showing decent rain signals starting mid-next week into the following week. Currently favoring E OK into Missouri/Arkansas but will likely change
https://www.tropicaltidbits.com/analysis/models/gfs/2023090106/gfs_apcpn_scus_64.png

Still hot…. but man these mornings have been very nice. Early walks (or anything outside) are a good activity !

Still hot…. but man these mornings have been very nice. Early walks (or anything outside) are a good activity !

Amazing what dew points in the low 60’s will do when you’re used to the high 70’s! And two weeks ago it was over 80! Humidity will stay lower through the weekend but starts to increase early next week ahead of the frontal boundary

The mornings and evenings have been nice (thanks low dewpoints) but I’m tired of this heat. It’s September dang it! The start of the nicest season in Oklahoma. I’m ready for fall temps!

GFS forecasted rainfall through end of next week. Definitely entering a cooler and wetter pattern starting next weekend
https://www.tropicaltidbits.com/analysis/models/gfs/2023090406/gfs_apcpn_scus_55.png

Echoing BG918, I'm starting to feel pretty good about our chances of a nice cooldown and widespread rainfall as early as Sunday. More likely on Monday, but regardless, relief does seem to be on the way.

In the meantime, expecting scattered thunderstorms to develop along a weak cold front around peak heating tomorrow. Short-range models differ on whether these will develop directly over the Metro, or just to the south, but in any case it'll just end up being a nowcast based on where the front ends up being located at 5-6 p.m. or so. Wouldn't be surprised to see the SPC issue a Marginal Risk for damaging winds but any severe threat should remain fairly localized.

General thinking for today's thunderstorm threat remains roughly the same as what I posted last night. Weak cold front currently extends from Hollis to Cherokee and will continue to sink slowly SE throughout the day. Wherever the cold front is located around 5-6 p.m. is where scattered thunderstorms will initiate. Short-range models seem to think this will be directly over Oklahoma County, so it's still entirely up in the air as to whether or not we will actually get storms this evening, or miss out by a few miles. The SPC has issued a Marginal Risk for the Metro, with a Slight Risk just to the NE. Weak shear and steep lapse rates suggest that the main threat will be downburst winds and marginally severe hail as storms pulse out.

Can clearly see the cold front/wind shift on the KTLX radar along a Perry-Okarche-Hobart line. Satellite imagery shows an altocumulus field just behind the front in Kingfisher and Garfield counties, and this will likely evolve into the first thunderstorm development of the day in approximately three hours. Still looking to be a really close call for whether or not OKC gets storms, though I'm slightly more confident than I was a few hours ago (maybe 50% as opposed to 40%).

HRRR wants to develop a narrow line of storms later this evening between 8-9 pm
https://www.tropicaltidbits.com/analysis/models/hrrr/2023090517/hrrr_ref_frzn_scus_9.png

Convective initiation ongoing over Piedmont, all areas to the SE will have a storm threat for the next 2-4 hours or so.

Severe Watch is out. This will be mostly for sporadic wind gusts, especially coming from collapsing storms.

Rain chances return tonight favoring NE OK. Statewide chances increasing Sunday into Monday with decent totals possible. High temps in the 70’s next week!

^^I always appreciate and look forward to your updates.

Today and Saturday still hot. Should see ridge breakdown Sunday evening and giveaway to cooler temps and some decent rain chances.

Sunday night:
https://www.tropicaltidbits.com/analysis/models/fv3-hires/2023090812/fv3-hires_ref_frzn_scus_60.png

Forecasted rainfall through next weekend. Other models are showing higher totals across western OK. This couldn’t come at a better time, it’s really dry out there

https://www.tropicaltidbits.com/analysis/models/gfs/2023090912/gfs_apcpn_scus_34.png

Any rain is better than no rain, but this rain is a lot lighter than I was hoping for. Are we supposed to get more through the day?

Any rain is better than no rain, but this rain is a lot lighter than I was hoping for. Are we supposed to get more through the day?

Yes, it looks like we should have another round move through around 5-8 p.m. this evening. Probably a half inch or so with that round.

Drier tomorrow and most of the day on Wednesday before another system moves through starting overnight Wednesday. Hopefully another half inch to an inch with that system.

HRRR radar at 9 pm. Heaviest rain will stay north of I-40
https://www.tropicaltidbits.com/analysis/models/hrrr/2023091118/hrrr_ref_frzn_scus_8.png

Really a nice, gentle but steady downpour at my house.

Pretty good little soaker.

I got my roof replaced last week and they have not gotten new gutters on. Would be good to have gutters tonight! Ha

. . .3/4" in my gauge! Meridian/NW 36th area.

That persistent drizzle overnight across C OK really helped out with soaking the ground. Similar system will swing through Thursday into Friday, but [right now] looks to be more focused on SW OK.

Looking ahead, still see above normal temperatures coming to close out the back half of the month. The moisture will likely keep actual air temps from getting too out of hand, but humidity will make it feel worse.

1.5 inch in Yukon.

Rain chances increasing again Wed night into Thursday, best chances across western OK but most of the state should see some rainfall. Another chance across mostly eastern OK on Saturday.

The unsettled weather pattern should stick around for next couple weeks with rain/storm chances every few days. Moderate temps in the 70’s this week and in the 80’s next week. Possibly some 90’s around 9/20-22.

This round of rain is looking more and more abysmal for C OK. Still likely to see random bouts of light rain showers off and on over the next 36 hours beginning tonight.

https://www.tropicaltidbits.com/analysis/models/nam3km/2023091318/nam3km_apcpn_scus_10.png


https://www.tropicaltidbits.com/analysis/models/hrrr/2023091318/hrrr_apcpn_scus_48.png

Yep the system is moving more south than originally forecasted. Good rains for Texas though. There is another weak system that moves through late Friday into Saturday that will have some showers and maybe a few thunderstorms.

Next week is one to watch. There could be multiple rounds of heavy rain through the following week. The exact bulls eye of heaviest rain is still unknown but some areas could pick up 3-4”

Yep the system is moving more south than originally forecasted. Good rains for Texas though. There is another weak system that moves through late Friday into Saturday that will have some showers and maybe a few thunderstorms.

Next week is one to watch. There could be multiple rounds of heavy rain through the following week. The exact bulls eye of heaviest rain is still unknown but some areas could pick up 3-4”

Was going to say, looks like we are entering a springlike pattern starting around the 19th or so. Going to be interesting.

Was going to say, looks like we are entering a springlike pattern starting around the 19th or so. Going to be interesting.

The state fair is here so the rain comes!

Yep the system is moving more south than originally forecasted. Good rains for Texas though. There is another weak system that moves through late Friday into Saturday that will have some showers and maybe a few thunderstorms.

Next week is one to watch. There could be multiple rounds of heavy rain through the following week. The exact bulls eye of heaviest rain is still unknown but some areas could pick up 3-4”

Wherever the bullseye is, we know it won't be OKC. OKC has missed the bullseye for rain 98 times out of the last 100.

Wherever the bullseye is, we know it won't be OKC. OKC has missed the bullseye for rain 98 times out of the last 100.

Well...that would make sense, given that a bullseye is only about 3% of a dartboard. And also, OKC absolutely hit the rainfall bullseye back in early July.

Well...that would make sense, given that a bullseye is only about 3% of a dartboard. And also, OKC absolutely hit the rainfall bullseye back in early July.

Don't let the recent dry weather fool you, this has been a fantastic summer for rainfall across most of the state. There are still some dry areas along the Red River, north-central OK and parts of SE OK but overall we're in much better shape than most years heading into our second wettest period of the year after May/June.

I don't know that I've ever seen a summer rainfall map as evenly distributed from east to west. 16"+ in the Panhandle...in the summer...unbelievable!
https://data.prod.mesonet.org/data/public/mesonet/maps/realtime/rainrfc.2160hr.png?cache_bust=1694703637941

We will possibly get some spotty showers over the next 24 hours or so, but the higher chances will continue to focus to our west. Even if rain does occur, precipitation amounts should be fairly minimal. Our six day stretch of mostly cloudy conditions will come to an end tomorrow evening, as clouds should rapidly clear out starting around sunset. This will set up two of the nicest weather days of the entire year on Sunday and Monday, with high temperatures in the mid 80's, low humidity, plentiful sunshine, and light winds. Thereafter, we will enter into a weather pattern that will be very reminiscent of springtime, with strong S/SE winds bringing in Gulf moisture to the area. A dryline will set up somewhere in the vicinity of Western Oklahoma or the Panhandles, and a large trough over the Western U.S. will eject numerous shortwaves into the area, potentially allowing for repeated rounds of organized convection starting as early as Tuesday. Too early for specifics, but this timeframe definitely deserves close attention IMO.

I would expect to see Risk areas highlighted by the SPC for the end of next week by the end of this weekend.

Stormy week on tap across Oklahoma. Forecasted rainfall totals through next weekend:
https://www.tropicaltidbits.com/analysis/models/gfs/2023091706/gfs_apcpn_scus_31.png

I would expect to see Risk areas highlighted by the SPC for the end of next week by the end of this weekend.

Well I didn't see Tuesday a being the day

Severe risk on Tuesday
http://www.weather.gov/images/oun/graphicast/image3.png?e94059a4147ab0b2a3f0d74ba9c071a3

Could be some locally heavy rain from the storms that develop on Tuesday. Exact areas is still too difficult to call, but I-35 corridor and points NE are favored early this evening.

https://www.tropicaltidbits.com/analysis/models/nam3km/2023091818/nam3km_apcpn_scus_20.png

I presume the storms this morning limit our severe weather threat later today?

I presume the storms this morning limit our severe weather threat later today?

Well it really depends on how quickly they move out and if the atmosphere can destabilize afterward.

From the Storm Prediction Center: https://www.spc.noaa.gov/products/outlook/day1otlk.html

Convective and severe potential should ramp up this afternoon as the
boundary layer diurnally/diabatically destabilizes south of the
morning clouds/convection (across parts of southern OK and north
TX), southwest of it atop a strongly heated/mixed boundary layer
near the dryline, and perhaps behind it over western/central OK late
this afternoon. The latter potential is more uncertain and
conditional, given time needed for both direct heating/
destabilization and warm advection in the recovering low-level air
mass immediately preceding the second mid/upper-level perturbation.

Where convection can develop over northwest TX and OK, especially
near any dryline/outflow intersection, supercells are possible amid
strong veering of winds with height in low/middle levels, yielding
well-curved and favorably enlarged hodographs. Development appears
best focused near the dryline over the southwestern OK/northwest TX
area, with sustained heating and MLCINH erosion likely, but less
low-level shear. Conversely, coverage is more uncertain in and
north of the backed-flow regime, though hodographs will be more
favorable. As such, too much mesoscale uncertainty lingers to
assign a more-specific, focused area of higher unconditional
probabilities at this time.

The convection-allowing models are all over the place with regards to possible solutions for late this afternoon/early this evening, which is fairly typical for events with cloud debris and subtle forcing. Would expect NWS Norman to launch a special sounding at 1 p.m. in order to get a better understanding of what the atmosphere is going to look like. Best guess is that storm coverage will be relatively isolated, but any storm that does form will pose a threat for significant severe hail.

Clearing occurring here in OKC, but short-range models only redevelop strong storms across SW OK. Perhaps a rogue cell could fire W of OKC along I-40... But I would lean towards OKC being done.

Satellite trends have me leaning towards re-initiation NW of OKC between 5-7 p.m. with storms then moving through the Metro around 7-10 p.m. but this will ultimately be a nowcast situation. If storms do form, still looking at large hail as the main threat (isolated significant/2"+ hail not out of the question). Secondary wind threat, especially if upscale growth starts to occur before storms exit the area.

Here is MD for upcoming SVR Watch for most of NW TX into SW OK and nudging into C OK.




Mesoscale Discussion 2162
NWS Storm Prediction Center Norman OK
0336 PM CDT Tue Sep 19 2023

Areas affected...northwest Texas into southwest Oklahoma

Concerning...Severe potential...Severe Thunderstorm Watch likely

Valid 192036Z - 192130Z

Probability of Watch Issuance...80 percent

SUMMARY...Isolated thunderstorm development is expected over the
next 2-3 hours. Very large hail and strong wind gusts will be
possible with these storms. A severe thunderstorm watch is likely
this afternoon or early evening, but timing is uncertain.

DISCUSSION...Strong heating has allowed temperatures to warm into
the upper 80s/low 90s across the OK/TX Panhandles into western
OK/northwest TX. Persistent low-level warm/moist advection also has
maintained dewpoints in the upper 50s/low 60s while aiding in
erosion of convective inhibition. Increasing/deepening cumulus is
evident in visible satellite imagery over the TX Panhandle/South
Plains vicinity, suggesting subtle large-scale ascent is spreading
east across the region. Additional cumulus development beneath
weakening cap has also been noted over western north TX.

A zone of moderate instability (to around 1500 J/kg MLCAPE)
overlapping with effective shear magnitudes greater than 35 kt will
support organized convection, with a mix of supercells and clusters
anticipated. Forecast soundings show enlarged, curved low-level
hodographs becoming straight/elongated above 2-3 km. This wind
profile, coupled with midlevel lapse rates near 8 C/km, suggest very
large hail (some greater than 2 inch diameter) will be possible,
even if storms are somewhat elevated due to lingering low-level
inhibition (which increases with eastward extent and also with time
into the evening). Isolated strong gusts also will be possible. A
severe thunderstorm watch will likely be needed late this afternoon
or early evening, but given subtle forcing mechanisms and lingering
inhibition, timing is a bit uncertain.

..Leitman/Hart.. 09/19/2023

MCD is out for basically all portions of the state to the south and west of OKC with a severe thunderstorm watch likely to be issued at some point in the near future. I still feel that initiation is possible to the north of I-40, but it is admittedly more uncertain than to the south of I-40. If initiation is limited to points south of I-40, storms will likely make a run at southern portions of the Metro between 7-10 p.m. but chances will decrease rapidly the further north you are. If initiation does also occur to the north of I-40, what I said in post #48 is still valid.

https://www.spc.noaa.gov/products/md/md2162.html

Watch is now out just west of OKC and as far north as Kingfisher County so I would say that the entire Metro should remain weather aware heading into the evening.

Pair of cells going up N of Weatherford. These will have a shot at metro impacts.

One cell flying up from SW OK is about to hit southern sides of the metro. Also another smell severe cell moving into W sides of Edmond. SVR Watch has been extended to include all of OKC for these two storms.

Warning just issued for a large chunk of the Metro.

Next round of storms is looking like it could be mid-afternoon tomorrow. We are currently in a Marginal Risk for tomorrow but would not be surprised to see an upgrade to Slight Risk for a hail threat at some point.

Greatest severe weather threat is mostly in southern OK today. Storms move through central OK this evening with even better chances statewide overnight into Friday morning
https://www.tropicaltidbits.com/analysis/models/hrrr/2023092111/hrrr_ref_frzn_scus_13.png

Today MEH. SATURDAY could be the day. A slightly slower trend puts North Central Oklahoma in the bullseye. Right now looking like a NE Oklahoma event including Tulsa area but something to really keep an eye on.

Another loud morning across parts of OK tomorrow. This is 8 am
https://www.tropicaltidbits.com/analysis/models/hrrr/2023092120/hrrr_ref_frzn_scus_17.png

If you are up and down I-35 from Norman north to the Kansas Border and along I-44 from OKC to Tulsa please pay attention to Saturday. It's early I know it's only Thursday things are going to change but just keep paying attention to changes that are going to happen.

https://twitter.com/ConvChronicles/status/1704917434061206005/photo/1 Kind of shocked the OKC TV Mets are not in superhype mode.

Jeez. What a bust this storm system was for okc. There’s not a cloud in the sky so far west of mcalester.