Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/04/24


Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
908 PM CDT Wed Jul 3 2024 .KEY MESSAGES... - Showers and Storms This Evening and Overnight; Uncertainty with Severe Potential - Additional Shower/Storm Development Thursday Afternoon; Conditional Severe Threat - Flooding Possible With Heavy Rainfall && .DISCUSSION... Issued at 402 PM CDT Wed Jul 3 2024 Note, forecast confidence is fairly low. Overnight activity, which is uncertain because of today`s cloud cover, will largely dictate Thursday activity. H3 trough axis is currently moving across the Rockies this afternoon and has been keeping upper-level flow generally southwesterly. This is sending a series of H5 short-waves and localized vort maxes into the upper Midwest and lower Missouri River Valley. Stationary thermal boundary remains parked from far southeast Kansas across Central Missouri. Persistent upper-level divergence ahead of the main trough axis has helped to augment lift and keep sky conditions overcast for most of the day. The first short-wave perturbations is approaching the KS-MO state line and has been generating light shower activity mainly along Interstate 70 and south. Most of the instability is confined to south of the thermal boundary, with MLCAPE values around 1500 J/kg. The cloud cover has prevented further destabilization this afternoon, which is likely the reason for more general shower activity rather than robust thunderstorm activity. Earlier this morning, CAMs were showing some deeper cores attempting to develop, but cycles through the afternoon have held off on convection. May see a few thunderstorms develop with one of the passing short-waves, but overall lapse rates are note greatly impressive. We may again see some wind if we see precipitation loading, but the boundary layer is not as well mixed as it was last night. The HRRR along with other CAMs are pointing to stronger storms developing after 06z this evening along the front that will begin moving southward as H5 height falls continue overnight. This will produce more convergence from Interstate 70 and southward. Some concern that the CAMs may be over estimating the instability a bit. HREF mean values overnight are generally around 1000 J/kg. Instability may be better further south toward the Interstate 44 corridor. The low-level jet will increase low-level wind shear overnight in our southern counties and overall hodographs to lengthen with the mid-level vort max increasing mid-level flow. If convection initiates, it may be able to organize. If convection develops, main issue will be wind gusts around 60 MPH, as LLJ momentum could be dragged down by precipitation and precipitation loading could lead to more downburst like storms. However, confidence in this is rather low. We will also need to watch storm training trends along the front. Overnight, our southern counties are expected to see around 0.50 to 0.75 inches of rainfall, which that itself is not an issue. However, if the probability matched means from HREF output, between 1.50 and 2.00 inches are realized, we may see some flash flooding. This has prompted the Flood Watch for our southern counties. Continued rainfall Thursday may also lead to more flooding. A lot of this is conditional on realizing deep convection. The current front then exits the Ozarks by mid-morning on Thursday. More short-wave trough action over the Central Plains though will continue to provide dCVA and result in surface cyclogenesis across much of Kansas, with surface pressure falls extending eastward into the lower Missouri River Valley. A trailing cold front will begin to propagate across Kansas and eventually reach the MO-KS state line by the middle of Thursday afternoon. The convergence along this front will be strong, and likely augmented by larger scale synoptic ascent ahead of the next localized mid-level vort max. Likely will see thunderstorm development by Thursday afternoon that then continues into the evening, mainly for Hwy. 36 and southward, though some activity will make it to the Iowa state line. The main question is how much instability develops. There will be stronger WAA and theta- e advection into the area that will continue to keep dewpoints in the upper 60s to lower 70s across the region. If there are any breaks in cloud cover or weak subsidence through the morning, insolation through a moist boundary layer will quickly result in destabilization. Current HREF has been depicting mean SBCAPE values near 2000 J/kg. With the surface pressure falls and backing surface winds, with secondary jet streak moving over, long veering hodographs will begin to develop. Stronger updrafts will have the potential to become severe, and could develop supercell structure to a few of the discrete storms. Mid-level lapse rates are again not looking that impressive given how moist the column is, but with rapid boundary layer destabilization and plenty of moisture, stronger updrafts are still possible. Precipitation loading once again will present a wind threat with stronger storms. Perhaps stronger shear could support some larger hail, though with the large amount of melting not sure hailstones much larger than half-dollar would survive to the ground. There could be a conditional tornado threat if the low-level hodographs curve enough at the time of favorable forcing and lower LCLs, however if areal coverage of storms quickly increases would expect a lot of disruptions to the inflow of individual storms. Overall, would be most concerned about downburst winds with storms tomorrow. Will need a close watch on meso analysis for trends in both the wind field and instability to assess threats/hazards with storms. And if there is too much convective debris from morning activity, we may not see much in the way of impressive storms. Even if storms are not overly robust, will still be concerned about lightning activity storms for July 4th activities, and may still see sub-severe wind gusts. In addition, PWATs will likely again exceed 2 inches, which could lead to efficient rainfall production. Again the heavier rainfall may concentrate south of U.S. Hwy. 50, which could result in more flooding. Thus, the flood watch will be in effect through midnight Thursday Night. Overall ensemble probabilities for exceeding one inch of rainfall in our southern counties is around 30 percent. HREF probability matched means for 24 hours totals are around 2 inches, with higher amounts further into the Ozarks Region. For the remainder of the week into the weekend, temperatures will be in the upper 80s to lower 90s. Current ensemble probabilities indicate mostly dry conditions through Friday after the cold frontal passage. However, more short-wave activity into the weekend will bring additional rain shower and thunderstorm chances. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 901 PM CDT Wed Jul 3 2024 Ceilings slowly improving with MVFR conditions returning around 09z for all TAF sites. The shower activity from Kansas has already moved across the area at all TAF sits and moved east as of 02z. However the uncertainty with the thunderstorms past 09z is increasing confidence as the thunderstorm line from Nebraska looks to be pushing southeast towards Missouri with potential to be around 06z-09z. This potential for shower and thunderstorm activity late tonight into the early morning hours with potential between 09-12z. There is a severe thunderstorm risk further on Thursday July 4th particularly for areas highlighted from KMCI, KMKC, and KIXD brining low ceilings, thunderstorms and winds but it will also depends the activity for overnight tonight. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...Flood Watch through late Thursday night for MOZ040-045-046-053- 054. KS...Flood Watch through late Thursday night for KSZ060. && $$ DISCUSSION...Krull AVIATION...Kreller
Area Forecast Discussion
National Weather Service Goodland KS
907 PM MDT Wed Jul 3 2024 .KEY MESSAGES... - Fog may develop tonight through sunrise. - Breezy 4th of July; normal to below normal temperatures into early next week. && .UPDATE... Issued at 904 PM MDT Wed Jul 3 2024 Severe Thunderstorm Watch has been allowed to expire on time. A line of thunderstorms continues across the far eastern portion of the CWA. A rogue gust of 50-60 mph is still possible but the threat has lessened considerably allowing for the expiration of the watch. Will need to watch for fog formation overnight as the RAP continues to show a saturated surface layer along with light and variable winds occurring. If fog were to develop it appears it would be most favorable along and east of a Wray to Gove City line. Locally dense fog may be possible. && .SHORT TERM /THROUGH THURSDAY NIGHT/... Issued at 204 PM MDT Wed Jul 3 2024 Across the Tri State region this afternoon, skies are a partly to mostly sunny mix as lingering/increasing cumulus remains from this morning, and has been slowly increasing this afternoon. Temperatures as of 100 PM MDT are ranging in the 80s with a persistent southerly flow area-wide, with gusts up to 30 mph at times. The main wx concerns for the short term period will be the threat for severe thunderstorms this afternoon and evening. Currently there are a couple weak persistent boundaries along/north of Highway 36, and a large front/trough over northeast Colorado just west of Yuma and Kit Carson counties. The latest CAMs are showing the front to the west to be the main initiator of rw/trw. Both the HRRR and NamNest are showing a broken line of storms developing/approaching the western CWA boundary around 22z, potentially in 2-3 segments to start. These clusters of storms will then push through the CWA and possibly forming into one line around Highway 27 then push E/SE through the remainder of the area. 40-60% chance of precip during the peak times through 03z. The latest SPC Meso Analysis is showing 1500-3000j/kg of SBCape already spread out over the CWA after main cloud cover dissipated west to east by midday. DCape from Highway 27 west is ranging from 1000-1500j/kg with the highest numbers closest to the front previously mentioned. Bulk effective shear is 30-40 knots from the W/NW. Low level lapse rates are increasing into the 8-9C/km over portions of the CWA, while mid level numbers are highest near the front off west around 8-9C/km, but are slowly increasing east towards our area. With this, will be looking for all hazards possible for the region through this evening. SPC still carries a Slight Risk for severe over us with hatched hail/wind threats. Could see the wind more as storms move east into Kansas, but hail could be the initial threat. The difference between today and past few days is the lower levels are not as dry, making hail more possible. Enhanced Stretching parameter around 6 is now over the CWA, and with CAMs showing a potential bowing structure in KS after 00z Thursday, potential for QLCS tornadoes spin ups does exist. High PW values from 1-1.2" west increase to 1.3-1.6" in the east, making locally heavy rainfall a possibility. WPC carries a Marginal Risk for excessive rainfall as a result. Looking for precip to taper from west to east between 00z-06z, with some lingering scattered rw/trw in the east before exiting. Thursday and Thursday night looks to remain mostly dry. There is a low chance(15-20%) for a rw/trw in the far SW due to a weak shortwave passage. For temps, looking for highs on Thursday to range in the upper 70s into the mid 80s. Overnight lows for tonight will range in the mid 50s west into the mid 60s east. For Thursday night, in the 50s area- wide with warmest locales east of Highway 25. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Issued at 1214 PM MDT Wed Jul 3 2024 NW flow looks to be present across the Plains as a highly amplified ridge develops across the western CONUS. Will be continuing to watch for daily chances for showers and storms as this is a pattern that is favorable for subtle waves moving along the eastern periphery of the amplified ridge. Slight chance to chance pops (20-40%) look to remain across the CWA for most days with perhaps the relatively more favorable days looking to be Saturday and Sunday as guidance is hinting at a stronger wave within the northwest flow to impact the area. It does appear that there may be some severe weather potential with it with shear around 30-40 knots across the area and CAPE between 1000-1500 j/kg but is a bit to earlier to nail down exact specifics at this time. As for temperatures they are looking to continue to remain near normal to below normal with highs generally in the 80s across the area. The exception does look to be Saturday where some low 90s could sneak into the area. Temperatures do look to increase as towards the start of the new work week as the ridge and associated surface high start move more easterly. As this occurs then the chances for rain will begin to diminish with it as well. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 511 PM MDT Wed Jul 3 2024 For KGLD, through at least 06z Thursday there will be at least low chances for a thunderstorm to impact the terminal or be in the vicinity. Right now through 02z, 6sm miles reduction to visibility with hail possible. From 06z onward, mainly VFR expected w/ the chance for MVFR ceilings from 11z-13z. Winds, south 15-25kts through 06z Thursday, then dropping to south- southwest 10kts. By 11z, northwest 15-25kts. For KMCK, mainly VFR conditions expected. There could be VCTS impacting the terminal through about 11z Thursday along with light rain. Low confidence on timing, but will update as some develop/approach the area. 11z-14z Thursday, MVFR ceilings possible then VFR from 14z onward. Winds, south-southeast 15-25kts through about 03z, then 10kts. By 11z, northwest 10-20kts. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...None. CO...None. NE...None. && $$ UPDATE...Trigg SHORT TERM...JN LONG TERM...Trigg AVIATION...JN
Area Forecast Discussion
National Weather Service Green Bay WI
1012 PM CDT Wed Jul 3 2024 Updated aviation portion for 06Z TAF issuance .KEY MESSAGES... - Next round of widespread showers/storms arrives from the west Thursday afternoon/evening, becoming more widespread overnight. Confidence is increasing these showers/storms will impact fireworks displays the night of the 4th, especially across central and north-central Wisconsin. - Threat for flooding is increasing Thursday evening into Friday from this next round of heavy rain. Rivers and streams will likely rise, with some urban/rural flooding also possible. - The unsettled weather pattern continues Sunday through (at least) Tuesday with on and off chances for rain/storms. && .DISCUSSION... Issued at 347 PM CDT Wed Jul 3 2024 Heavy Rain Threat / Precip Chances: Showers have developed across northwest and north central WI early this afternoon, so will continue with isolated showers this afternoon and evening, especially over northern WI, as we reach peak heating and the robust cumulus clouds track eastward. Still can`t rule out a rumble of thunder as instability of nearly 1000 J/kg and steep low level lapse rates will continue this afternoon. Dry conditions are expected later tonight into Thursday morning. Attention turns to the arrival of the next round of showers and storms on the 4th. Deterministic and CAMs still showing slightly different scenarios, especially the HRRR which seems to be a fast/more aggressive outlier. Would like to ignore this solution, but it has captured some events in recent weeks, so won`t completely throw it out. Leaning toward a model blend, have only made minor changes to the going forecast for the 4th, bringing in chance PoPs from west to east through the day, with one round possible in the later morning and afternoon associated with a push of some elevated instability and weak warm/moist advection, then the main round in the evening into the overnight as the main shortwave, low pressure and upper trough drop across the region. Still some uncertainty on just how progressive this system will be, which will likely determine how much rain we will get. While PWATs won`t be as tropical as yesterday (when we had spots over 2 inches), still respectable values approaching 1.5 inches late tonight into Friday will be supportive of additional heavy rain. Additional rainfall of an inch or two is looking likely (40-70 percent of an inch or more, highest in central WI) from Thursday afternoon into Friday evening, which could aggravate flooding issues. Considered a flood watch for parts of the area that have received the most rainfall the past 2-3 days, mainly central and east central WI, as the continued bouts of heavier rain have led to flash flood guidance (FFG) to decrease and the overall flood threat to increase with each event. Parts of the Fox Valley have 1-hour FFG around/just under an inch, with 6-hour FFG between 1-2 inches. Parts of central WI are closer to the 1.5-2.5" range. The pockets of heaviest rain have been in different locations over the past few days and there has been at least a day or two of dry conditions to help rivers/low drainage areas to lower. With the heaviest rain still 24+ hours out, and some uncertainty on where the heaviest bullseye will be, will opt to hold off on any flood watch at this time but continue to highlight the flood threat in the HWO. The threat for severe weather will be low, as the better surface instability and effective shear will remain to our southwest. But some of the stronger elevated storms could produce some hail. SPC did maintain a marginal risk for severe weather in the far southwest forecast area. Saturday is looking dry as high pressure slides across the region. Then the pattern turns unsettled again Sunday into at least Tuesday as another large trough slowly rotates across the western Great Lakes. Some bouts of heavy rain will once again be possible with PWATs climbing back over 1 inch, possibly creating additional flooding concerns. Winds / Fog / Temps: Winds have struggled a little today as mixing was a little hampered in spots, but west winds could gust to around 25 mph the rest of the afternoon, then as mixing decreases, winds will decrease toward sunset. Lighter winds are expected tonight into Thursday. Patchy ground fog will be possible late tonight as winds die off, but SREF/HREF showing widespread fog potential under 5%. There will be additional fog chances during the overnight and early morning hours, especially after the heavier rain events and if/when skies clear. Above normal temps will continue into Thursday, then a brief cool down arrives on Friday. Temps rebound close to normal for the weekend and into next week. && .AVIATION...for 06Z TAF Issuance Issued at 1002 PM CDT Wed Jul 3 2024 Mainly VFR conditions expected through Thursday afternoon, with deteriorating flight conditions occurring over north central and central WI Thursday evening. Clear skies, light winds and wet ground from recent rainfall could lead to patchy ground fog overnight, but confidence is too low to add to the TAFs. An approaching low pressure system and warm front will bring a chance of showers and storms to mainly central WI late Thursday afternoon, though timing is still a bit uncertain. More widespread showers and storms should overspread the region Thursday night, possibly reaching the eastern TAFs by late evening. Light west to southwest winds will become southeast to east Thursday afternoon and evening. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....Bersch AVIATION.......Kieckbusch
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
913 PM CDT Wed Jul 3 2024 .KEY MESSAGE... - A couple rounds of showers and storms are expected Thursday; one during the morning and a second during the late evening and overnight. There is increasing confidence in a relative lull in precip coverage during the late afternoon and evening. && .UPDATE... Issued at 913 PM CDT Wed Jul 3 2024 While a stationary frontal boundary remains draped across central Illinois this evening, the effective boundary is much further south from the Ozarks into the Ohio River Valley where a broken line of convection has developed. Other than an isolated shower or two south of I-70, the majority of the KILX CWA will remain dry for the balance of the evening and through a good portion of the overnight hours. Clusters of thunderstorms currently developing on the tail end of the stationary front across Nebraska/western Kansas in association with a short-wave trough ejecting out of the Rockies will track/develop eastward overnight. Latest runs of the HRRR/RAP continue to suggest convection reaching locations along/southwest of a Rushville...to Shelbyville...to Robinson line before dawn Thursday. As the wave approaches, showers and storms will overspread much of central Illinois after sunrise...before shifting eastward into Indiana by midday. Have updated hourly PoPs to better reflect current obs and expected trends tonight. Have also added patchy fog to the forecast tonight as calm winds and dewpoint pooling in the vicinity of the front will be conducive for fog. CAMs have been slow to catch on, but the most recent runs of the HRRR and GFSLAMP are trending foggier. Barnes && .DISCUSSION... Issued at 209 PM CDT Wed Jul 3 2024 This afternoon, synoptic cold front is located roughly near the I-55 corridor, while effective front from earlier convection just barely clips the southeastern forecast area near Lawrenceville. Temps jump from the low 80s north of the effective boundary to around 90F south. Anticipate this to be the main focus of convection as we head into the mid to late afternoon hours. Latest RAP suggests around 1500J/kg or higher MLCAPE is in place on the warm side of the boundary, but deep layer shear is marginal/sub- marginal around 20-30kt. Storms should begin to increase in coverage in this vicinity by late afternoon or early evening, and a few could be strong to marginally severe. Latest HRRR keeps this activity a county or two south of the forecast area which lines up well with current location of the front. Overnight into Thursday morning, a pair of shortwave troughs will move across central Illinois resulting in an increase in showers and a few storms. Weakening surface front will likely stay stalled across portions of southern Illinois with weak/negligible instability in place north of the front across central Illinois which will keep the threat for severe storms out of the local area. After the shortwave exits central Illinois early Thursday afternoon, there is growing confidence in a relative lull in precip later Thursday afternoon and at least early evening before a stronger shortwave digs across the Upper Midwest later Thursday evening into Friday. Despite passage of the weaker shortwave midday Thursday, mid level height falls will persist across central Illinois through the day in advance of the next deeper wave, contributing to at least some spotty convection during the afternoon/early evening, but coverage should be fairly isolated at this point, and should allow many locales to kick off their Independence Day celebrations. By mid to late evening, moderate instability (MUCAPE 1000-1500 J/kg) begins to lift back north into portions of central Illinois coinciding with the arrival of the deeper wave / closed 500mb low into the Midwest. Storm coverage will increase in response. Unfavorable diurnal timing should keep the severe threat low Thursday night into Friday morning, but a few stronger storms are possible, especially west of I-55, with seasonably strong deep layer shear overspreading central Illinois. As upper wave begins to depart the region Friday, strong cold air advection will overspread central Illinois in its wake and scour out some of the low level moisture. There will be a brief respite from the precip chances once this occurs and will persist into Friday. Temps will be lower, too, with afternoon highs generally in the upper 70s to lower 80s Friday and Saturday. Surface ridge axis will shift across the area Saturday afternoon with return flow overspreading the area Sunday. Heat and humidity will begin to creep back up in response and broad upper troughing over the Great Plains will be in place with several shortwaves ejecting across the region Sunday through the first half of next week bringing additional chances for showers and storms. Deubelbeiss && .AVIATION... (For the 00z TAFs through 00z Thursday Evening) Issued at 639 PM CDT Wed Jul 3 2024 Diurnal MVFR ceilings that developed across central Illinois this afternoon have scattered as of 2330z: however, a thick blanket of cloud cover AOA 15,000ft continues to stream across the sky from the southwest. Convective development has thus far been confined to locations much further south near the Ohio River and will continue to be focused south of the TAF sites through tonight. HRRR/RAP have been consistently showing showers/thunder spreading N/NE late tonight into Thursday morning, so have added a period of predominant showers between 12z and 18z at KSPI and between 13z and 19z at KDEC/KCMI. Further northwest, have only mentioned VCSH. While thunder will be possible at the I-72 terminals Thursday morning, have opted not to include it at this time until trends become better established. Once the morning showers depart, a relative lull in precip chances will be on tap for Thursday afternoon. Winds will remain light/variable through the entire 00z TAF period. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Northern Indiana
624 PM EDT Wed Jul 3 2024 .KEY MESSAGES... - There remains a low chance for showers into this evening, mainly along the US 24 corridor. - Chances for showers and thunderstorms remain in the forecast Thursday into Friday, best chances (40-60%) late Thursday night into Friday. Warm and humid with highs in the mid 80s. - Dry conditions and near normal temperatures for the weekend. Near normal temperatures look to stick around for much of next week (highs mid 80s, lows mid 60s) with sporadic, low chances for rain/storms. The best chances for rain/storms will be on Tuesday. && .DISCUSSION... Issued at 224 PM EDT Wed Jul 3 2024 Warm and humid conditions have returned as a warm front lifted north through the area overnight. A weak cold front is currently entering our area, with showers/storms possibly developing out ahead of it this afternoon and early evening. There is a Marginal Risk for severe weather (level 1 of 5) along and south of US 24. A few storms could be strong to severe, with damaging wind gusts and heavy rain as the primary threats. Storm coverage should be isolated to scattered at best. I would not be surprised if SPC chooses to pull the Marginal Risk entirely from our area as there is very low confidence in storms reaching severe criteria. Model guidance continues to trend with less instability (500-1000 MLCAPE) this afternoon, and low/mid level lapse rates are sub- par amidst only 20 to 30 knots of 0-6 km shear to work with. If the RAP is correct, there also could be an EML to work with this afternoon that caps any storm development. There are additional chances for rain/storms for the Fourth of July and again Friday. As a surface low lifts northeast across Missouri Thursday evening, the attendant warm front will lift north through our area. This could result in some rain/storm chances for Thursday evening, although I`ve kept the highest chances (30-40%) confined to along and south of US 30 for now. These PoPs will likely need adjusting in subsequent forecast updates as we get more certainty as to how far north the warm front gets. Should the boundary stall across our area, this would lead to lingering showers/clouds overnight Thursday into Friday morning. Friday`s rain/storm chances are conditional to what happens Thursday; should any clearing occur Friday morning, there would be chances for rain/storms to redevelop again late morning through the afternoon on Friday along a cold front. I would not be surprised if SPC adds us into a Marginal Risk on Friday given the favorable parameters for severe weather, especially on the NAM and NAMNST. Soundings midday Friday from the NAMNST depict an unstable environment with 2000+ J/kg MLCAPE, 40 kts of shear, and moderately steep low and mid level lapse rates. For the weekend, dry conditions, comfortable humidity, and cooler temperatures return! Saturday will be the cooler day of the weekend with highs in the mid 70s. Next week, the latest CPC outlook has near normal temperatures favored (which would mean highs in the low 80s, lows in the mid 60s), which is somewhat unusual for mid July. There has been a pretty consistent signal in model guidance the past few days that next week will be near normal for temperatures with sporadic, low chances for rain/storms. There are no consistent signals for high heat to return until possibly 10 to 14 days from now. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 623 PM EDT Wed Jul 3 2024 Weak cool front will wash out into KFWA tonight into tomorrow. Low chances for an isolated shower remains in the forecast into this evening here, with KSBN dry and mainly clear north of the boundary. Additional low chances for showers then arrive late Thursday morning into Thursday afternoon on the northern fringes of a convectively aided shortwave. Mainly VFR with light winds otherwise, though will have to watch for patchy fog/stratus development at KFWA toward daybreak given moist low levels and light winds. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Johnson AVIATION...Steinwedel
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
814 PM CDT Wed Jul 3 2024 .KEY MESSAGES... - Widely isolated thunderstorms possible south of I-80 Thursday morning and areawide by late afternoon. Conditions do not favor widespread thunderstorm potential. - For prime July 4th fireworks display time Thursday evening (through ~10 PM CDT), thunderstorm chances appear low but not zero, with higher t-storm coverage expected overnight/early Fri. - Next favorable window for scattered or higher thunderstorm coverage appears to be Sunday PM and on Monday. - Temperatures averaging near seasonable through mid next week. && .UPDATE... Issued at 814 PM CDT Wed Jul 3 2024 No significant changes to going forecast for tonight. Main focus continues to be on the potential for isolated (10-20% coverage) showers and thunderstorms south of about a Pontiac IL to Wheatfield IN line this evening, and along the WFO LOT/ILX border region overnight. Latest surface analysis depicts a weak, nearly-stationary cold front along the above mentioned line. Surface temps in the low-80s and dew points in the low-70s characterize the low-level air mass ahead of the front, though RAP forecast soundings indicate fairly poor lapse rates above a shallow boundary layer maintaining some weak capping. Low-level winds are very light, less than 10 kts on either side of the front, providing only weak low-level convergence as well. Mid- level winds (and resulting deep layer shear) have increased a bit since this afternoon however, in association with a weak mid-level short wave tracking east-northeast out of Missouri, which may yet aid in developing a few isolated showers or thunderstorms across our far southeast counties through mid-late evening and a couple of shallow, isolated showers have developed over far southeast Iroquois and Benton counties recently. The weak front is expected to slowly sag toward a Bloomington IL to Rensselaer line overnight, which along with the aforementioned mid-level wave, may result in a few additional isolated showers or storms across our far south cwa overnight. Going forecast has this well-covered, with slight (20%) pops along the boundary through the night. Forecast into Thursday continues to look reasonable as well, with a gradual increase of convective chances south of the Illinois and Kankakee river valleys by mid-late morning as the front begins to lift slowly back north in association with a potential MCV developing from activity currently ongoing across western KS. Ratzer && .DISCUSSION... Issued at 300 PM CDT Wed Jul 3 2024 Through Thursday: A cold front drifting SSE has continued to force isolated warm- core showers within an axis of pooling low to mid 70s dew points roughly south of a Pontiac to Valparaiso line. Modest mid-level warming around 500-600 hPa should greatly mitigate thunderstorm chances, but a few sporadic lightning strikes cannot be ruled out with the strongest cores. This activity will continue to shift SSE with the front into early evening. The cold front will stall/wash out across the far southern CWA and over central Illinois tonight. Isolated showers and perhaps a few lightning strikes cannot be ruled out at anytime tonight south of a Bloomington to Rensselaer line as the right entrance of a 80 knot upper speed max remains generally stationary above a weakly capped and higher theta-e airmass. A mid-level wave crossing southern Colorado this afternoon will force a cluster of convection along a boundary lifting northward across southern Kansas/Missouri overnight. Guidance depicts a decent amount of spread in the downstream trajectory of the (now convectively enhanced) wave is it tracks into central/southern Illinois by late Thursday morning. This is likely the result of the MCV favoring a WNW to ESE MUCAPE gradient toward far southern Illinois in opposition to the stronger WSW steering flow aloft directed into central Illinois. Overall expectations are for the better coverage of convection to remain south of the forecast area, but for the footprint of the wave to potentially force isolated to widely scattered storms south of the IL/Kankakee River Valleys late morning into the early afternoon. Beyond early afternoon, diurnal heating and modest low-level moistening will support a weakly capped airmass across much of the CWA. Overall forcing by this time looks to be quite nebulous with little mid to upper-level forcing in place. However, any subtle low-level convergent boundaries like residual outflows, an expected lake breeze, or axes of differential heating from scattered mid/upper-level clouds could ultimately force isolated showers or possibly a few storms mid-afternoon into early evening. This does not appear to be a wash-out by any means, but enough for those with holiday plans to keep mindful of forecast updates through the day. Kluber Thursday Night through Wednesday: Early to mid Thursday evening, surface low pressure will be centered over southern Minnesota, with its trailing cold front extending southward across central Iowa and northern Missouri. The parent short-wave trough will also be centered well back to the north and west, resulting in only minor mid-level height falls into the western Great Lakes. A majority of forecast soundings depict a largely capped environment, at least to any deeper convection capable of producing lightning. With relatively dry mid-level air being drawn northeastward and sunset, it`s questionable if just enough moisture may materialize at the right level to tap into 250-1000 J/kg of MUCAPE. Given the above with frontal convergence/forcing well west but modest large scale forcing and near climo PWATs, there may be spotty isolated to perhaps widely scattered showers (highest chance/30-40%) near and west of I-39 in the 7-10pm timeframe. Current signs point toward the peak fireworks display time probably being dry in much of the area, though as noted, can`t rule out a few showers in the area. Confidence is lower in any thunderstorms being able to develop, at roughly 15-30%, highest near/west of I-39. This period will needless to say be monitored closely. Shower chances may uptick some/ooze farther east in the late evening, though thunder potential is still questionable. As the cold front sweeps across the region after midnight, stronger large forcing (increased height falls and frontal convergence) and a bit better column moisture should more readily erode MUCIN to offset the diurnally unfavorable timing for numerous showers and scattered thunderstorms. A seasonably muggy night can be expected out ahead of the cold front, with temperatures in the 70s most of the night and dew points well into the 60s. On Friday, following a quieter balance of the morning, the seasonably stout mid- upper trough (500 mb heights in the mid 560s DaM) will translate east from Wisconsin to northern Lake Michigan. Steepened low-mid level lapse rates from cold air advection and maximized mid-level height falls should result in isolated to widely scattered showers near and north of I-80. Can`t rule out an isolated rumble of thunder or two, though diminishing lower level moisture (decreasing Td) looks to be a limiting factor. A fairly tight pressure gradient over the region and deeper mixing will result in westerly winds gusting up to 30-35 mph. Looking at highs in the mid 70s to lower 80s, coolest for the northwest 1/3 or so of the CWA. Friday night through Saturday evening will be quiet from weak surface high pressure sliding east across the area, along with seasonable temperatures, albeit with lower humidity levels. Broad west-southwest to southwest flow aloft and seasonable to above normal column moisture (PWATs 100-150% of normal) will likely open the door for periodic scattered shower and thunderstorm chances Sunday through Monday evening. While there may be sufficient deep layer shear for some storm organization during peak diurnal favorability, it doesn`t appear to be a favorable synoptic pattern for noteworthy severe weather. In the wake of the cold front passage Monday night, humidity levels may come down some, with primarily dry conditions. Castro && .AVIATION /00Z TAFS THROUGH 06Z FRIDAY/... Issued at 649 PM CDT Wed Jul 3 2024 Forecast concerns include... Low chance for showers/thunderstorms Thursday afternoon/evening. Wind directions Thursday morning. Light westerly winds will likely continue through the evening into the early overnight becoming variable or calm by the predawn hours. Wind directions will eventually become more easterly by mid morning Thursday with a lake breeze expected for ORD/MDW/GYY keeping wind directions easterly through the afternoon. Further inland, winds are expected to turn southerly. There will be a chance of showers well south of the terminals Thursday morning. Then there will be a low chance for isolated showers or isolated thunderstorms across northern IL and the terminals Thursday afternoon into Thursday evening. There is little to focus any development, with perhaps the lake breeze aiding any isolated development. Confidence is too low to include any mention for both uncertainty for timing and coverage. There may be better chance for showers and a few thunderstorm late Thursday evening into early Friday morning, ahead of a cold front. cms && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at weather.gov/chicago
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
736 PM CDT Wed Jul 3 2024 .KEY MESSAGES... - Thunderstorms and locally heavy rainfall likely for tomorrow and tomorrow night. - Chances for showers and a few thunderstorms will linger into next week with temperatures remaining below normal. && .DISCUSSION... Issued at 312 PM CDT Wed Jul 3 2024 If you`re a fan of fair weather days... enjoy this one while it lasts! Temperatures will drop into the mid-low 70s around sunset, and cloud cover will begin to increase from the southwest overnight. The upper trough over the northern Rockies is still on track to deepen and develop a closed low as it moves east into the Upper Mississippi Valley early tomorrow. A band of showers and few storms will likely develop along the warm front across western MN shortly after midnight, eventually expanding north and east throughout the morning. Outside of some isolated precip, most locations will likely see a few hours of dry conditions before more scattered to widespread showers and storms develop during the afternoon. CAMS continue to favor less of a widespread heavy rain event, and more of a localized concern depending on what areas see the strongest and most numerous storms. In other words, a broad swath of 1+ inches of rain is still expected across southern and central MN, but CAMS suggest that only a county or so will see values in excess of 2-3 inches. The area of focus looks to be somewhere within south- central MN (just west of the TC metro) where the deformation zone is expected to set up (northwest of the surface low). HREF probabilities have a line of 40-60% chance for greater than 2 inches of rain (in 24 hours) extending from Redwood Falls up towards Rogers, MN. As we head into the evening, precip should become more isolated across southern MN while showers and storms closer to the low should be favored with the continued synoptic lift. A few strong to severe storms are possible during the afternoon and evening, however a few factors could limit things. 1) Lapse rates will be modestly steep at best (about 6-7 C/km); 2) Extensive cloud cover could limit instability, with only 500-1500 J/kg of CAPE expected (greatest over southeast MN); 3) elongated/straight hodos suggest splitting cells could interact/interfere with one another; and 4) vertical wind shear will also be somewhat modest (25-35 kts), potentially limiting storm organization. That said, all hazards will be on the table for any storm that is able to develop and become organized. Given the relatively cooler temperatures aloft and the hodo signatures, hail development would be favored, with a few instances of large hail possible. This hail threat was noted as the main reasoning for our upgrade to a Slight risk (level 2 of 5) on the SPC Day 2 Convective Outlook. Non-supercell tornadoes/funnels will also be possible, especially near the surface low as it tracks through southeastern MN. Bursts of heavy rain and strong winds will be likely with any organized storms as well. Several more chances for rain will be possible through the middle of next week as the upper level heights remain in a western ridge, central trough pattern. QPF amounts continue to look meager from event to event, but could total up to an additional 1-2 inches for some through this period. Temperatures will stay near or below normal into next week, before potentially climbing as we head into mid-July. Both the GEFS and EPS suggest a few days in the 90s will be possible, but this will largely be dependent on how/if the ridge over the western CONUS builds eastward. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 632 PM CDT Wed Jul 3 2024 A very unsettled period is expected as we see a mid-level low track across southern MN on Thursday. Looking at the path of 850mb & 700mb low, the HREF shows these features tracking from roughly Montevideo to Wabasha, along/north of this track will be a favorable zone of forcing for seeing multiple rounds of precipitation and thats what`s expected for most of the MPX terminals. A continuous rain is not expected, but it will be on & off activity for a good 12-20 hours. TS potential looks greatest from the afternoon into evening. Surface pressure pattern will be very baggy through the day on Thursday, so wind directions will be tough to pin down, but speeds will be under 10 kts. Finally, RAP soundings show low levels moistening up enough late in the afternoon to start bringing in MVFR cigs for locations that area expected to be north & west of the developing surface low. KMSP...Models are absolutely all over the place with when/where clusters of SHRA/TSRA will be through the day on Thursday and into Thursday night, hence why precip mentions in the TAF are VCs or PROB30. Current thinking is that the band of showers along the eastern Neb/SoDak border will send an initial round of showers through the metro during the morning, with a brief lull in activity during the afternoon, before thunderstorms quickly redevelop. As mentioned above, winds could be coming from just about any direction on Thursday, though speeds will be generally 5 kts or less. /OUTLOOK FOR KMSP/ FRI...MVFR SHRA/TSRA likely. Wind N 10G20 kts. SAT...Chance PM MVFR SHRA/TSRA. Wind SW 5-10 kts. SUN...MVFR/SHRA/TSRA likely. Wind SW 10G20 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...BED AVIATION...MPG
Area Forecast Discussion
National Weather Service Marquette MI
746 PM EDT Wed Jul 3 2024 .KEY MESSAGES... - Breezy westerly winds through the early evening with gusts up to 20mph common area-wide, and higher gusts to 30-35mph possible across the Keweenaw. - Pop-up showers/thunderstorms (20-30% chance) will be possible into the evening. - Low chance (~25%) of afternoon showers/storms across interior western Upper Michigan on Independence Day. - Widespread moderate rain expected late Thursday night into Friday evening. Some thunder possible. - While not a washout...scattered shower and thunderstorm chances return for Sunday. && .SHORT TERM /THROUGH TONIGHT/... Issued at 230 PM EDT Wed Jul 3 2024 RAP analysis shows mainly zonal flow setting up over the area this afternoon as a closed low continues to move through northern Ontario, towards Hudson Bay. Over the Great Lakes, skies have been able to turn sunny with large-scale subsidence indicated in water vapor imagery. However, with diurnal mixing, plenty of agitated cumulus has popped off over the UP. This remains fairly well capped over the west, but cooler cloud tops are apparent in the eastern UP. This hints at a chance for some isolated to scattered showers and storms across the central and eastern UP as we head through the late afternoon and evening hours. Given only a few hundred j/kg of CAPE over the area, no severe weather is expected. Though any rain totals should be light for the most part, areas where multiple storms can move through could see QPF in excess of a quarter inch. This is most likely in Luce county, where the highest cloud tops are already developing (perhaps some lake breeze convergence?). Otherwise, temperatures are turning much warmer than yesterday, with most of the area already well into the 70s and lower 80s. The exception is in the eastern UP, where areas along Lake Michigan continue to struggle to get out of the 60s courtesy of onshore flow. Meanwhile, winds remain on the breezy side, with gusts up to 20mph common across the western half of the UP. Higher gusts in excess of 30mph continue to be observed at times across the Keweenaw. Winds should fall back as we head into the evening and the boundary layer decouples. Tonight, ridging will continue to strengthen over the forecast area, with any lingering convection over the eastern UP wrapping up by midnight. Outside of that, though, it will be a dry night with overnight lows generally in the 50s, low 60s to the south. && .LONG TERM /THURSDAY THROUGH WEDNESDAY/... Issued at 319 PM EDT Wed Jul 3 2024 High pressure centered over Lake Superior will provide a pleasant Independence Day for most of the U.P. into the afternoon hours. By later afternoon weak shortwave moving east from main upper trough over the Upper Mississippi Valley may help trigger a shra or tsra near the WI border. Most will remain dry through the day. Light onshore flow near Lake Superior will keep temperatures a little cooler than today but inland temperatures will once again climb to around 80. Main upper trough and surface low will move from Wisconsin Thursday night to northern lower Michigan by Friday evening. Shower and isolated thunder chances will increase significantly across the west by late evening with rain chances becoming likely across the remainder of the U.P. during the overnight. On and off rain and isolated thunder will continue through much of the day on Friday. Cool northeast winds off Lake Superior will keep temperatures in the upper 50s to around 60 near Lake Superior with mid 60s inland. Winds will be more easterly over the eastern U.P. so temps will climb into the lower 70s there. Most of the U.P. with the exception of the Keweenaw will see between 0.50- 0.75 inches of rain with locally higher amounts especially along the pivot point of the low track and where any isolated thunder occurs. Precip amounts will be much lighter across the Keweenaw. High pressure and clearing skies will move in Saturday morning leading to a pleasant seasonable summer day. The next quick moving disturbance will move in from the west Sunday afternoon with shower and thunderstorm chances increasing through the day and lasting into Monday. High pressure builds back in by Tuesday afternoon and will persist through the middle of next week with seasonable summery weather continuing. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 744 PM EDT Wed Jul 3 2024 Showers have generally moved east of the terminals this evening and will be dying out after sunset. Gusty winds will also be subsiding after sunset. Otherwise, VFR prevails for the forecast period. && .MARINE... Issued at 319 PM EDT Wed Jul 3 2024 Westerly winds that have been a little gusty around the Keweenaw and Isle Royale will diminish quickly this evening. Winds will then remain below 20 kts into Friday morning. Low pressure moving across WI into northern lower Michigan on Friday will allow northeasterly winds to increase to perhaps as high as 25 knots over the eastern Lake Friday afternoon and early evening before the low moves off to the east later Friday night. Southerly winds ahead of the next front moving across the Lake on Sunday may briefly approach 20 knots but all and all a fairly quiet stretch of marine winds is expected over the weekend into the middle of next week. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...LC LONG TERM...MZ AVIATION...Voss MARINE...MZ
Area Forecast Discussion
National Weather Service Reno NV
249 PM PDT Wed Jul 3 2024 .SYNOPSIS... * High pressure brings a prolonged heatwave starting tomorrow and lasting through the middle of next week. * Afternoon highs will be 10-20 degrees above average by the weekend resulting in a moderate to major HeatRisk, a Heat Advisory for the California portions of the region, and an Excessive Heat Warning for the western Nevada portions. * It will remain very dry with typical afternoon breezes, and a very low chance, less than 5%, for precipitation in the weekend. .DISCUSSION... The latest RAP upper air analysis shows high pressure over the Pacific Ocean allowing for the CWA to have a northwesterly flow aloft being underneath the forward portion of an upper air ridge. Current surface observations along with satellite imagery show sunny skies this afternoon with generally light and variable winds though eastern portions of the CWA are reporting the occasional gust up to around 20 mph. Going forward through the rest of the week and into next week, forecast guidance projects the upper air ridge dominating the upper air pattern over the western CONUS through at least Tuesday night when it may start finally advancing eastward on next Wednesday. With this pattern potentially staying in place, the region looks to see temperatures within the region increase with triple digits possible in some portions for multiple days. While dry conditions are mostly expected to prevail, the main hazard for the upcoming days will be the above normal temperatures and heat. According to the latest run of the NBM, portions of western NV now see a 20-60% probability of reaching 100F or greater on Independence Day. By Friday, these NBM probabilities increase to 50- 80% with portions of northeastern CA starting to enter into the area of coverage. By Saturday and lasting through the following days through Wednesday, NBM probabilities increase even more to around 60- 95% percent within the CWA. As a result of these probabilities showing multiple days of triple digit temperatures as well as the latest HeatRisk guidance being moderate to high in the region, the Excessive Heat Watch for western NV has been upgraded to an Excessive Heat Warning beginning on Saturday and lasting through Wednesday at this time. Also, a Heat Advisory has been issued for the eastern CA counties of the CWA with daytime high temperatures ranging between 90-100F with some locations possibly exceeding the century mark. Please see these heat products for more details on this upcoming heat hazard. It is recommended to take precautions during this time such as limiting outdoor activity, taking breaks in a cool area, staying hydrated, and checking in on neighbors and relatives that may be more susceptible to heat related illness. For more heat safety tips, please visit weather.gov/safety/heat. It is also worth noting that the Reno Area has not had more than two consecutive days of 105F high temperatures in climate history with the last time of this occurring being in mid July of 2023. There could be a chance that this consecutive day record is broken along with daily high temperature records with the upcoming heat. Winds through the period are still are expected to be generally light or typical for this time of the year. However, some models are hinting at a slight uptick with wind gusts up to around 40 mph in mountain areas especially on Sunday. This would bring some concerns for fire weather after a period of hot and dry conditions. Models are also still showing some hints of precipitation on each day beginning Sunday and going into the middle. However, the chances for showers and thunderstorms still remain at or below 5% at this time. Will continue to monitor this in case these chances increase. -078 .AVIATION... VFR conditions expect to persist at all REV TAF sites today and going into tomorrow. Models show clear skies over the region with the exception of a few clouds over western NV tonight during the overnight hours. Winds look to be generally 10 kts or less at most sites with the exception of KMMH seeing gusts up to around 20 kts out of the west between 21Z-03Z. Temperatures continue to rise through the weekend resulting in density altitude concerns across the whole area. -078 .FIRE WEATHER... No major changes from the previous fire weather forecast package with above normal temperatures and dry conditions prevailing for the rest of the week and into next week. However, winds generally look generally light and unsupportive of critical weather at least through the remainder of this week. However, models are hinting at some gusts near or above 30 mph starting on Sunday, especially over mountain areas. So, will continue to monitor these conditions over the next few days as this could lead to periods of near critical conditions for those localized areas. There are also some very slight chances for showers and thunderstorms starting on Sunday afternoon. However, these chances remain at or below 5%. -078 && .REV Watches/Warnings/Advisories... NV...Heat Advisory from 10 AM Saturday to 10 AM PDT Wednesday NVZ002. Excessive Heat Warning from 10 AM Saturday to 10 AM PDT Wednesday NVZ001-003>005. CA...Heat Advisory from 10 AM Saturday to 10 AM PDT Wednesday CAZ070>073. && $$
Area Forecast Discussion
National Weather Service Shreveport LA
957 PM CDT Wed Jul 3 2024 ...New UPDATE, SHORT TERM... .SHORT TERM... (Tonight through Friday Night) Issued at 944 PM CDT Wed Jul 3 2024 Air temps are running all through the 80s, but working down out of the upper end anyway. Shreveport Regional was 84 last hour, but with the deep soil temp so warm, we are still radiating heat into the air and edged back to 87 with a light S/SW wind. KSHV had a nice shower and rainbow late today as the sea breeze rode all the way up I-49 with a nickel in the bucket. As usual, more wind than rain this far north with a gust to 32 mph at 639pm, but what little coverage we managed develop before sunset is nearly all gone at this time, aside from two tiny late arrivals over Toledo Bend at this time. So no planned changes as the pop grid goes silent at 03Z in a few minutes. We will resend the zones at that time to remove any further widespread mention of rainfall this evening. Although the HRRR does crop up a few more QPF blips, coverage will be quite isolated. Most sites are calm with some patchy fog possible where rain did wet the ground. /24/ && .LONG TERM... (Friday through next Tuesday) Issued at 301 PM CDT Wed Jul 3 2024 Thursday night`s storms will only become more widespread Friday morning, moving to cover the entire region into the afternoon hours. At this time, the entire ArkLaTex is highlighted in the general thunder area by the SPC, and careful attention will be given over the next few days to any potential for more organized stronger storms. This will mark the beginning of a more prolonged unsettled pattern for the ArkLaTex, as the upper level ridge which has been locking in our heat all this week finally begins to shift off to the south and east enough to allow the upper level trough digging south over the Plains to swing its associated surface boundary into the region, looking to become stalled here throughout the extended forecast period. This new pattern will be characterized by more seasonable temperatures with highs in the lower 90s and lows in the lower 70s, owing primarily to near daily rainfall chances as several waves of storms keep conditions damp through the weekend and into early next week. Meanwhile, the model guidance consensus continues to track Hurricane Beryl on its westerly course, potentially bringing impacts to southern Texas. While impacts to the ArkLaTex do not likely as of this writing, we will of course be monitoring the latest forecast updates attentively. /26/ && .AVIATION... (00Z TAFS) Issued at 704 PM CDT Wed Jul 3 2024 For the 04/00Z TAF period, outflow driven convection has pushed as far north as the I-20 corridor early this evening with brief impacts at SHV in the form of heavy downpours and gusty winds. This isolated convection will diminish with the setting sun in the next few hours with limited convective debris clouds lingering overnight. However, VFR conditions are expected to prevail although patchy low stratus may become scattered closer to daybreak along and south of I-20. Otherwise, look for a similar trend of expanding cu field Thursday with S/SW winds averaging between 5-10 kts. /19/ && .PRELIMINARY POINT TEMPS/POPS... SHV 82 100 81 98 / 20 10 10 40 MLU 79 97 79 95 / 20 20 10 60 DEQ 76 97 74 91 / 10 10 30 40 TXK 80 99 78 96 / 10 10 20 40 ELD 77 97 75 94 / 20 20 20 60 TYR 80 99 78 96 / 0 0 10 30 GGG 79 98 78 96 / 20 10 10 40 LFK 77 97 77 97 / 20 10 0 30 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...Excessive Heat Warning until 8 PM CDT Thursday for ARZ050-051- 059>061-070>073. LA...Excessive Heat Warning until 8 PM CDT Thursday for LAZ001>006- 010>014-017>022. OK...Heat Advisory until 8 PM CDT Thursday for OKZ077. TX...Excessive Heat Warning until 8 PM CDT Thursday for TXZ097-112- 126-138-150>153-165>167. Heat Advisory until 8 PM CDT Thursday for TXZ096-108>111-124-125- 136-137-149. && $$ SHORT TERM...24 LONG TERM....26 AVIATION...19
Area Forecast Discussion
National Weather Service Topeka KS
616 PM CDT Wed Jul 3 2024 .KEY MESSAGES... - Thunderstorms are forecast across the area late this evening and overnight, which could bring strong winds to central KS and heavy rainfall particularly across east central KS. - A few severe thunderstorms are possible in eastern KS for the late afternoon and early evening hours of Independence Day. - Another chance for storms Saturday night into Sunday, otherwise slightly below normal temperatures continue into next week. && .DISCUSSION... Issued at 254 PM CDT Wed Jul 3 2024 Upper air pattern hasn`t changed a lot in the last 12 hours with broad cyclonic flow over the northern tier of the US and the ridge over the southeastern US leaving us within southwesterly flow aloft. Sfc ridge has been slowly moving southeast from NE into KS today, while the frontal boundary from yesterday has remained stationary across southeastern KS. Scattered showers are still more robust southwest of the area with light rain slowly moving northward. Lapse rates are rather meager over the area, so thunderstorms should be pretty isolated the rest of this afternoon into the early evening with perhaps some dry time before the main round of storms comes in late tonight. A vort max passing through the flow aloft should initiate storms off the High Plains later this afternoon into the early evening, and CAMs remain in good agreement on those moving east into our area late tonight. Most places should stay dry until after midnight, except perhaps far western locations in the CWA. Generally speaking, these storms should also weaken as they move east as MUCAPE looks to remain under 1000 J/kg, but still can`t rule out a few damaging wind gusts toward central KS if storms remain strong enough when they enter the area. Heavy rainfall looks to be the bigger concern for most of the area. At this time, the moisture axis is progged to set up just south of the forecast area where PW is forecast to be 2+ inches. This area in southeast KS to southwest MO is also where the HREF shows the strongest signal for rainfall amounts exceeding FFG, with the 90th percentile having totals of 2-3". That said, the HRRR has not been nearly as aggressive on this as some other individual CAMs have. If more guidance starts to show some of these higher amounts creeping north just a little bit, a Flood Watch may be warranted for our far southeast counties. The overnight batch of storms should push east of the area around sunrise or shortly thereafter. A few additional showers and storms may develop in central KS mid to late morning before moving out or dissipating by afternoon. The main storm chance comes with a frontal boundary crossing the area during the day, although lingering cloud cover does lead to some questions about how well the atmosphere will be able to recover and destabilize ahead of that boundary. Assuming there is enough instability, thunderstorms look to develop near the KS Turnpike around 4pm and then move east/southeast. Damaging wind and heavy rainfall are again the main threats. Think the main time frame for this activity should last until around 8pm, so most can hope to see dry weather by the time fireworks celebrations begin. By Friday, the main upper trough is progged to be in the Upper Midwest and Great Lakes regions, leaving the area in northwest flow. Another shortwave ejecting through that looks to bring our next chance for storms Saturday night through Sunday. Otherwise, temperatures are forecast to remain slightly below average throughout the next 7 days with highs in the 80s and lows in the 60s. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 616 PM CDT Wed Jul 3 2024 Light showers will persist at the terminals over the next few hours, ending at KMHK within the hour and KTOP and KFOE by around 8 PM. Another round of thunderstorms will be possible later, around midnight, and persist into the morning hours. MVFR ceilings moving in behind will remain the main aviation hazard for much of the day Thursday before skies begin to scatter out following a cold front passage. Have kept out mention of VFR ceilings for lack of confidence in timing, but should begin in the mid afternoon Thursday as winds shift out of the northwest. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Picha AVIATION...Griesemer