Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/31/18


Area Forecast Discussion
National Weather Service Albany NY
939 PM EDT Mon Jul 30 2018 .SYNOPSIS... An approaching warm front may kick off a shower or thunderstorm tonight into Tuesday, before more widespread showers and thunderstorms impact the region on Wednesday. There will be a continued threat for wet weather through the remainder of the week, with temperatures running a little above normal. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... SHRA from earlier this evening has pretty much dissipated on schedule. HRRR shows a period of dry weather into the early morning hours with some development of mainly light SHRA overnight. RAP keeps things dry. So, have opted for mainly slight chance POPs for western zones increasing to chance far northwest zones in the overnight hours. A look at thunder parameters suggests slight chance at best. So will keep with the slight chance in places where precipitation is forecast. With skies expected to remain mostly cloudy, have not forecast any FG. With the clouds, temperatures will range in the low to mid 60s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... We return to a wet and unsettled weather pattern this week as our region remains under broad southwest flow aloft. On Tuesday, an upper level shortwave, currently over the upper Mississippi Valley, will dig into the Ohio Valley. This will result in a sharper trough axis, and upper level energy to traverse across our area. PWATs will increase throughout the day as well, with values rising to around 1.5 inches by late afternoon. There could be a few showers or thunderstorm around, mainly in the afternoon, but large scale forcing still will be too far south and west for convection to be widespread. Will keep POPs limited to just slight chc/chc across the area and many areas may wind up staying completely dry the evening hours. Sky cover will vary between partly to mostly cloudy. Highs on Tuesday look to reach into the low to mid 80s for valley areas. By Tuesday night into Wednesday, there will be a better chance for showers and thunderstorms, as the upper level shortwave over the Ohio Valley lifts northeast towards the eastern Great Lakes and our areas continues to be located with a deep south to southwest flow aloft, transporting plenty of tropical moisture into the area. Although the shortwave will be weakening as it slides on the top of the upper level ridging over the western Atlantic, there will be better lift across the area as compared to earlier in the week and moisture will continue to increase as well, with PWATs now as high as 2.10 inches across the area. Any shower or t-storm will be capable of locally heavy downpours, especially during peak heating on Wednesday, where we have posted likely POPs. With the moist airmass in place, lapse rates are expected to be fairly poor and instability may be limited due to widespread cloud cover, but shear looks like it will increase which may allow for some organized convection. Still not overly concerned about widespread severe storms due to the potentially limited instability and lapse rates, but cannot rule out a locally strong storm in a few spots if enough breaks in the clouds can occur during peak heating. The Storm Prediction Center has placed our entire area under a Marginal Risk for severe weather for Wednesday/Wednesday night. Lows on Tuesday and Wednesday nights will be in the upper 60s to near 70 and highs on Wednesday once again look to reach low to mid 80s for valley areas. && .LONG TERM /THURSDAY THROUGH MONDAY/... The latter half of the week will be warm and muggy with scattered late afternoon and evening showers and thunderstorms. A weak frontal boundary will spill in to keep Friday somewhat cooler than Thursday, but there will still be plenty of instability. The severity of the activity should be limited by extensive cloudiness and little atmospheric motion associated with a steady trof along the eastern seaboard. The trof moves to the south of our forecast area by Monday, where the showers and thunderstorms will become more focused. In the meantime, a broad Bermuda high will bring another surge in heat and humidity for the beginning of next week along with lessening cloudiness behind the trof. High temperatures will range from the mid 70s to upper 80s on Thursday, from around 70 degrees to the lower 80s on Friday, from the mid 70s to upper 80s again on Saturday, and from the upper 70s to lower 90s for both Sunday and Monday. Low temperatures all nights will be mostly in the 60s. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... VFR conditions forecast at all terminals. Currently SHRA activity ongoing west of KALB. Covered this with a VCSH for a couple of hours at TAF issuance time. Hi res models point to this activity dissipating in the next hour or two. Had mulled the possibility of at least a period of MVFR BR at KPSF/KGFL. However, with plenty of clouds around decided to continue VFR conditions through the night there. Otherwise, VFR conditions to hold at all terminals. Late in the period, there is a chance for some SHRA activity to encroach on KPOU. Covered with a VCSH. Outlook... Tuesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Wednesday: High Operational Impact. Likely SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Likely SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... Clouds will increase by Tuesday and there could be a shower or thunderstorm around. RH values will only be as low as 50 percent over the next two days with southerly winds of 5 to 10 mph. More widespread showers and thunderstorms, some which may contain heavy rainfall, are expected for Wednesday. && .HYDROLOGY... High pressure will continue to push east out of the area this evening, with the potential for an isolated shower tonight into tomorrow. With a moist air mass returning to the region, periods of showers and thunderstorms look to impact the region between late tomorrow night into Wednesday evening. Locally heavy downpours may accompany any shower or thunderstorm, which will be capable of producing flooding of urban, poor drainage and low lying areas. Although the convection won`t be widespread enough to flood larger or main stem rivers, smaller streams and creeks could locally reach bankfull conditions. Additional showers and thunderstorms are possible through the remainder of the week. We will need to watch the potential for additional heavy downpours, as it will remain quite humid, although coverage of showers and thunderstorms won`t be as widespread as Wednesday. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...OKeefe/JVM NEAR TERM...OKeefe/JVM SHORT TERM...Frugis/JVM LONG TERM...ELH AVIATION...OKeefe FIRE WEATHER...Frugis/JVM HYDROLOGY...MSE/Frugis/JVM
Area Forecast Discussion
National Weather Service Columbia SC
1037 PM EDT Mon Jul 30 2018 .SYNOPSIS... Upper level trough digging into the western Gulf States will result in increasing southerly and moisture as an upper level ridge remains over the western Atlantic. The trough will remain west of the area through the week with Atlantic and Gulf moisture supporting numerous to widespread showers and thunderstorms in the forecast area. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... The region is positioned between a positively tilted upper level trough extending from the Great Lakes region to the upper/central Mississippi Valley and a strong ridge of high pressure over the western Atlantic. Meanwhile at the surface, a general southeasterly flow prevails. This pattern has allowed for a deep feed of tropical moisture to stream into the region, with precipitable water values ranging from 1.8 inches across western areas to 2.2 inches across eastern areas. Model guidance has not handled radar trends very well to this point, but with a short wave lifting northward, we expect the chance of showers and thunderstorms to remain through the overnight hours. The threat for heavy rainfall with localized flooding exists tonight with the high precipitable water values and potential for training cells. Low temperatures will generally be in the lower to mid 70s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... Upper level trough will continue digging southward into the central Gulf States with moisture continuing to stream northward as the upper level ridge in the western Atlantic remains in place. Pwat values will be 2 inches or greater through the majority of the period with the threat of heavy rain continuing. Main time periods of concern will be during diurnal heating and late Tuesday and Wednesday evening into the overnight as models indicate some increased upper level divergence. With the significant rainfall over the region hydrologic concerns will be increased and with potential for widespread rainfall flooding will be a concern and flash flood watches may eventually be needed. WPC has much of the Midlands and CSRA in a Slight Risk, 10 to 20 percent, for Excessive Rain on Tuesday and it shifts slights nw on Wednesday. Temperatures through the period will be in the mid/upper 80s with overnight lows in the lower/middle 70s. && .LONG TERM /THURSDAY THROUGH MONDAY/... Models remain in very good agreement with confidence also remaining high in the wet pattern continuing through the end of the week. The region will be between the upper level trough to the west and the upper level ridge to the east with the trough slowly lifting through the end of the week. This allows the ridging along the Southeast coast to push westward into the Southeast. Models continue to indicate upper level divergence and pwat values around 2 inches the potential for heavy rain...and hydrologic concerns...will continue. Chances of rain will lower for the weekend however southerly flow over the region will keep significant moisture over the region although a trigger mechanism will be lacking. With the clouds and rain expected through much of the period temperatures will be slightly below normal. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... Restrictions possible in showers/thunderstorms and late night/morning stratus and fog through the period. Additional showers/storms have redeveloped along an inland moving boundary from the south and east. Current showers around OGB should last an hour or so, then the hrrr shows the potential for showers to make it into the CSRA sites between 01z-02z. Have mentioned vcsh at those sites, with a tempo at OGB for current activity. At this point, CAE/CUB is forecast to remain dry with the precip remaining south and east of those two sites. Will continue to monitor current activity and amend as necessary at all sites. Through the overnight hours, bigger aviation issue will revolve around redevelopment of early morning stratus and fog development. Ifr/mvfr stratus seems more probable than fog given a 15-20 knot low level jet and cloud cover. Expect a slow improvement back to VFR during the late morning/early afternoon on Tuesday and increasing chances of showers and thunderstorms through the day. EXTENDED AVIATION OUTLOOK...There will be numerous showers and thunderstorms especially during the afternoons and evenings. Widespread stratus and fog may occur during the late nights and early mornings. && .HYDROLOGY... WPC QPF for the 7 day period indicates the potential for 4 to 7 inches of rainfall across the headwaters of many of the area rivers. Due to the expected heavy rainfall, ensemble river forecast models are showing rises on the area rivers. Many of the reservoirs along the Savannah River, Catawba/Wateree are just below or near the curve for late July/early August. However, at this time most of the area rivers remain below advisory criteria. Will need to watch the potential through the week. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$ SYNOPSIS...99 NEAR TERM...99 SHORT TERM...99 LONG TERM...99 AVIATION...99 HYDROLOGY...
Area Forecast Discussion
National Weather Service Dodge City KS
602 PM CDT Mon Jul 30 2018 ...UPDATE TO AVIATION... .SHORT TERM...(This evening through Tuesday) Issued at 240 PM CDT Mon Jul 30 2018 Upper cold pool over the Missouri valley this afternoon may result in southward propagation of shower and thunderstorms into the I-70 corridor and portions of central Kansas by late afternoon. Whatever instability remains will be weakened with the loss of insolation heading into the evening. The rest of the evening and night will bring an increasingly clearer sky and much cooler temperatures. It was noted the low temp record at DDC for Tuesday is 50, and the cooler solutions are not far from these solutions in the low 50s mostly, especially across west central Kansas counties. HRRR soundings and NAM plan views are showing quite low to near saturated dew point depressions as the winds become light under high pressure toward 12 UTC. However, of the convective allowing models, only the NMM is indicative of any limited areas of dense fog development. Tuesday will bring the return of light south winds, and with full insolation, perhaps a warming through the mid 80s at best, as the region will still be under a boundary layer- cool to neutral advection pattern. .LONG TERM...(Tuesday night through Monday) Issued at 240 PM CDT Mon Jul 30 2018 For Wednesday and into the weekend, the ECMWF maintains increasing 500 mb heights across the central High Plains. The westerly momentum is focused across the northern tier of U.S. states and southern Canada during this timframe. A gradual warming and overall dry weather period is likely through the weekend, albeit model and MOS are showing well below average high temperatures through about mid week. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 600 PM CDT Mon Jul 30 2018 VFR conditions will prevail at all TAF sites through early Tuesday afternoon. Light and variable winds will persist across southwest and central Kansas through Tuesday afternoon as surface high pressure in the Dakotas sinks southward into the Central Plains during the period. && .PRELIMINARY POINT TEMPS/POPS... DDC 55 83 61 88 / 10 0 0 0 GCK 50 83 59 89 / 10 0 0 0 EHA 55 84 61 91 / 10 0 0 10 LBL 55 84 61 91 / 10 0 0 0 HYS 56 83 60 88 / 50 0 0 0 P28 60 85 63 90 / 50 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...JJohnson
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
917 PM CDT Mon Jul 30 2018 .UPDATE... Went ahead and increased PoPs for the rest of this evening (through midnight) based on latest radar trends and model data from HRRR and NAM12. These models are picking up on lingering outflow boundaries from earlier convection which generated across central Texas and coastal plains areas. As these outflows interact with each other and move over the escarpment and Hill Country, there is a chance for a line of scattered showers and isolated thunderstorms to develop across the areas above mentioned. Can`t rule out wind gusts of 20 to 30 mph with these storms if they do form. && .PREV DISCUSSION... /ISSUED 710 PM CDT Mon Jul 30 2018/ UPDATE... See below for the 00z aviation discussion... AVIATION... Currently VFR at all terminals under partly cloudy skies and east/southeasterly winds at DRT/SAT/SSF but northerly winds at AUS due to the influence from a strong outflow boundary that passed through earlier today. VFR conditions are expected to continue through the TAF period, although ensemble guidance does suggest a slight chance of some MVFR CIGs developing Tuesday morning. The main aviation concerns of this TAF period will be the chance for showers and thunderstorms impacting the terminals as well as an eventual wind shift to north/northeasterly winds at all sites following the passage of the cold front. Convection allowing models do not seem to have much consensus in terms of where the greatest convection coverage may be. Due to this uncertainty, have painted with a broad brush of VCSH at all terminals beginning near or shortly after midnight Tuesday morning and continuing through Tuesday evening. Better clarity and confidence in the evolution of these showers and storms will hopefully come for subsequent TAF issuances, and any amendments will be made as necessary. The cold front should pass through AUS by around 9z Tuesday, with it passing through SAT/SSF by around 11z and finally DRT by around 12z. This will ultimately shift winds to out of the north/northeast. Shower and thunderstorm activity will taper off from north to south on Tuesday evening as the front continues its gradual trek southward before eventually becoming stationary across south Texas. PREV DISCUSSION... /ISSUED 308 PM CDT Mon Jul 30 2018/ SHORT TERM (Tonight through Tuesday Night)... A strong outflow boundary from early morning convection to the north pushed through the northern half of the CWA late this morning and early this afternoon. The boundary is pretty much washed out by now but some lingering northerly winds are still out there. The larger and more widespread wind shift will occur late tonight and Tue morning as the advertised cool front pushes into the region. An upper short wave trough digging southeast through NE and KS will extend the MS Valley long wave trough down to the western Gulf of Mexico. This will be the upper level support needed to push the cool front down through South Central Texas. Scattered convection is still forecast to develop along and just ahead of the boundary late tonight with the best chances for rain predawn through late morning. Overall QPF will still be low based on current Meso-model output. A few lucky ones may be able to squeeze a half inch out of the activity. Most of the models decrease the SH/TS areal coverage by the Tue PM hours. We are in general thunder from SPC but with the current atmosphere, just like this mornings MCS, cant rule out wind gusts 40-50 mph if storms develop. Expect clouds and pop to decrease as Tue progresses...drying from north to south across the CWA. LONG TERM (Wednesday through Monday)... Kept Wednesday dry for now, a lot depends on the movement of the front and if it is able to fully move out of the cwa. Ridging rebuilds over the desert southwest late in the week so we will see a return of the heat, although it will take a few days to build back to our heat levels of recent days. Long range models do bring back some better moisture return, SAT-MON and thus have included some minor pop along the coastal counties SAT-SUN, and expanded it across the whole cwa on Mon. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 76 94 73 97 73 / 40 40 10 - 0 Austin Bergstrom Intl Airport 76 93 67 97 69 / 40 40 10 - 0 New Braunfels Muni Airport 76 94 71 98 72 / 30 40 10 - 0 Burnet Muni Airport 73 93 69 95 71 / 60 40 10 - 0 Del Rio Intl Airport 79 96 76 101 77 / 20 30 20 - 0 Georgetown Muni Airport 75 93 69 97 72 / 60 40 10 - 0 Hondo Muni Airport 76 96 72 100 71 / 20 40 10 - 0 San Marcos Muni Airport 76 94 71 98 72 / 40 40 10 - 0 La Grange - Fayette Regional 77 94 72 97 72 / 30 50 10 - 0 San Antonio Intl Airport 77 94 74 98 74 / 20 40 10 - 0 Stinson Muni Airport 78 95 75 99 74 / 20 40 10 - 0 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Mesoscale/Aviation...BMW Synoptic/Grids...17
Area Forecast Discussion
National Weather Service Houston/Galveston TX
916 PM CDT Mon Jul 30 2018 .UPDATE... Diurnal moist convection continues to wane across southeast TX this evening, while development persists over parts of e-central to central TX nearer larger scale surface front. While boundaries remain abundant from earlier storms, high res guidance suggests focus overnight for storms moving into our area will be tied to the larger surface convergence as it sags sewd tonight. Texas Tech WRF and latest HRRR both seem to latch onto this scenario, although each dissipate this activity early in the morning. How far south the overnight development can persist is a tough call, and will keep a general north-to-south gradient of higher-to- lower rain chances in place. Regardless, it appears the combination of multiple surface boundaries and moist/unstable air ahead of primary cool front should bring a better chance of rain to most areas Tuesday. Other than PoPs, have only tweaked winds/temps to better match observations. Evans && .PREV DISCUSSION... /ISSUED 641 PM CDT Mon Jul 30 2018/ AVIATION... Convection along/south of I-10 is primarily outflow driven and should wind down in the next couple hours with the loss of heating. Further north, where the area was stable in the wake of the larger outflow that pushed thru this morning has heated up to between 95-100 degrees and we`re starting to see some sct convection pop up near Lake Livingston. This activity may expand & sag closer to the UTS/CXO terminals in the next couple hours. We`ll be keeping an eye on the precip expected to develop across north/cntl Tx overnight ahead of a weak frontal boundary that`ll be sagging into se Tx later tonight and Tue. Confidence on it`s evolution/timing is fairly low at this time and will keep the mention of VCSH`s/VCTS`s already in the TAFs going until trends are better established. 47 PREV DISCUSSION... /ISSUED 330 PM CDT Mon Jul 30 2018/ A weak front moving into the region will bring us our best shot at showers and storms in some time, though the benefits of the rainfall aren`t likely to be seen equally by all. The front will cool things down a touch for the midweek, but we`ll begin slowly warming back up towards the weekend. A chance for showers and storms, particularly at the coast and over the waters, will return this weekend with Saturday looking like the better shot at rain at this time. SHORT TERM [Tuesday Through Wednesday Night]... As we head deeper into tonight, attention will shift back north towards an oncoming weak cold front. It won`t be a very dynamic system as the ingredients for strong forcing seem just a bit out of phase. But, we`ll have a focus for lift and plenty of moisture, so we should manage at least light to moderate rainfall, particularly around our northern border. As the upper jet fractures as it sags down, the trend in the guidance (and especially the HREF members) is for precipitation potential to come down. Some members regenerate precip near the coast Tuesday evening as it brings a portion of the jet streak into a more favorable position. I`m not so sure this is a solid bet, but it`s plausible enough to nudge PoPs back up at the coast for the nighttime hours on Tuesday. Slight chances for rain linger at the coast and over the Gulf into Wednesday as there`s some uncertainty about where the front will stall out, and how coherent it will remain. However, modestly cooler and drier post-frontal air should dry things out pretty effectively to the north and northwest of Houston. With some more available sun, Wednesday may already be a bit warmer than Tuesday, and a slow warming trend looks to continue into the long term. LONG TERM [Thursday Through Monday]... The upper trough that supports the early week cold front will also linger deep into the week, so while the subtropical ridge will try to build back across the southern tier of the US, a weakness remains more or less over our coastal area right into the weekend. Because of that, we don`t totally lose rain chances near the coast Thursday and Friday, despite a relatively poor environment. Odds are pretty good all or nearly all will stay dry in this period, I just can`t guarantee it yet and want to hold onto those low PoPs for now. Saturday will bring us another attempt at showers and storms as the upper weakness slowly fills - but not quite fast enough. As onshore flow resumes, moisture will get built back up. There looks to be a bit of help in the midlevels as the GFS and Euro both hint at increasing vorticity along a shear axis moving over the area, and this looks to be enough to bring us some scattered showers and storms, primarily closer to the coast. This may be somewhat variable, as ensemble members in the NAEFS cause small spikes each day from Friday through Monday, but it does paint a picture that we`ll have an improved chance for precip in this window. Whenever it does happen, and for the purposes of this forecast we`ll say Saturday - the increase in cloudiness and possible rainfall will again take the edge of our high temperatures, but it will only be a brief respite. MARINE... Variable winds and low seas are expected through midweek. Winds and seas could be higher in and near periods of showers and thunderstorms as a cold front approaches the coast. Toward the end of the week and on into the weekend, an onshore flow can be expected to return to the area. 42 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 76 93 72 95 72 / 50 60 20 10 0 Houston (IAH) 78 92 74 94 74 / 20 50 40 10 10 Galveston (GLS) 82 87 79 87 80 / 20 60 40 20 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$
Area Forecast Discussion
National Weather Service Lincoln IL
1051 PM CDT Mon Jul 30 2018 .UPDATE... Issued at 905 PM CDT Mon Jul 30 2018 Most of the showers have dissipated early this evening with the loss of daytime heating. A broad upper level trof remains anchored across the Midwest with several shortwaves noted on the Water Vapor loop rotating southeast across the Plains this evening. These waves will act on the frontal boundary well to our south to bring another band of showers into southeast Illinois late tonight through Tuesday morning mainly over southeast and east central Illinois. Short term forecast models continue to indicate the better 850 mb moisture transport and wind fields to our east and southeast tonight. However, as the upper wave tracks into west central Illinois late tonight, some of the deterministic models suggest showers will redevelop further west across central and west central Illinois. The higher POPs later tonight will continue to be across the east in support of the last several runs of the HRRR model with lower rain chances as you head west late tonight. These aforementioned shortwaves tracking southeast across the Plains tonight will effectively sharpen up the trof over the Midwest as they shift east on Tuesday with our area under the upper low and associated cold pool. This should result in showers redeveloping across the forecast area during the afternoon and then dissipate early tomorrow evening. Have also made some minor adjustments to the POPs and precipitation wording for the overnight hours. Updated ZFP out by 920 pm. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 330 PM CDT Mon Jul 30 2018 A strong upper level trof over the Midwest with 577 dm 500 mb elongated low from Lake MI sw into south central IA. Weak 1013 mb surface low pressure was along the western KY/TN border with its frontal boundary extending from the WV/OH border thru nw KY/TN/MS. A weak surface trof extending nw from surface low near the IL/MO border and into se Iowa. Radar mosaic shows isolated to scattered showers and isolated thunderstorms along and west of I-55 into IA/WI and east of IL over IN/KY. Broken to overcast low/mid clouds over all CWA except Knox and Stark county where partly sunny skies prevailed at mid afternoon. Temps at 3 pm were in the low to mid 70s, with upper 70s to near 80F from Peoria nw where more sunshine. Dewpoints range from around 60F nw of the IL river, to the mid to upper 60s from Pittsfield to Bloomington se with 71F dewpoint at Olney. Latest CAM models show isolated to scattered showers and a few thunderstorms to occur into tonight, though appear to decrease over nw CWA and increase in coverage from CMI, DEC and TAZ se. The 850 mb front that was near I-72 during the past two nights had brought a heavy band of 2-4 inch rain with locally 4-5 inches to central sections of CWA. Models continue to shift this 850 mb front into se IL by 00Z/7 pm today and further southeast toward the Ohio river overnight and back into southeast IL on Tue. Feel better chances of heavier rains will be further southeast overnight into Tue morning over parts of KY and IN. Have higher pops se of I-55 overnight into Tue with precipitable water values of 1.5-1.7 inches south of I-72. SPC day1 update keeps marginal risk of severe storms with damaging winds se of IL over KY and southeast IN thru tonight. With strong upper level trof over the IL river valley by 18Z/Tue, feel more isolated to scattered convection to develop there as well with daytime heating by Tue afternoon. Will also add patchy fog overnight to areas nw of the IL river where less cloud cover expected and temps cool toward dewpoints. Lows overnight range from upper 50s far nw CWA by Knox and Stark counties to mid 60s by Lawrenceville. Highs Tue in the upper 70s to around 80F with warmest readings nw of the IL river again. .LONG TERM...(Tuesday night through Monday) ISSUED AT 330 PM CDT Mon Jul 30 2018 Isolated showers/thunderstorms linger over eastern IL Tue evening, then only a few showers near the IN border overnight Tue night into Wed as upper level trof axis shifts east toward the IL/IN border by 18Z/1 pm Wed as it starts to weaken. Partly to mostly sunny skies expected Wed with warmer highs in the lower 80s. Continued 20-30% chance of showers and isolated thunderstorms over nw CWA Thu afternoon/evening as a weak disturbances tracks se into NW IL. Highs Thu in the mid 80s which is closer to normal readings for this time of year. GFS appears too wet on Fri while ECMWF keeps IL dry while GEM model has isolated convection by Fri afternoon from I-72 south. Consensus of models carries slight chance of convection se of I-55 Fri afternoon into early Fri evening. Highs Fri in the mid to upper 80s. Extended 12Z models continue to build a strong upper level ridge into IL by this weekend, bringing return of summer heat and humidity along with generally dry weather for most of this weekend. Have isolated convection Sunday afternoon into early Sunday evening east of the IL river and across the area on Monday. Highs in the upper 80s Sat thru Mon with a few cities likely reaching near 90F. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 1050 PM CDT Mon Jul 30 2018 Main forecast concern will be how far north the next batch of rain and MVFR cigs tracks late tonight through Tuesday morning. VFR conditions should continue into the early morning hours but the cigs will gradually start to lower later tonight, after 08z, as another wave of showers tracks north of the Ohio River valley. It still appears the areas from SPI to BMI and east have the higher probabilities for seeing at least occasional cigs lowering to MVFR category Tuesday. Further to the west at PIA, it appears other than the possibility for some patchy MVFR fog in the 10z-13z time frame, VFR conditions will dominate. Light east to northeast flow tonight will become northerly on Tuesday with speeds of 10 kts or less. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Smith SHORT TERM...07 LONG TERM...07 AVIATION...Smith
Area Forecast Discussion
National Weather Service Midland/Odessa TX
605 PM CDT Mon Jul 30 2018 .DISCUSSION... See 06Z Aviation Discussion below. && .AVIATION... A complex scenario will evolve over the next 24 hours as a cold front moves into the area. Models all exhibit differing solutions of convective development, timing, and placement. However, sfc analysis shows the cold front just northeast of the terminals, and this should increase moving to the SSE as diurnal cooling sets in. Both the 18Z NAM and GFS develop an impressive MCS and bring it thru KMAF 00-06Z. Elsewhere, models generally keep convection along the front as it sinks southward over the next 18 hrs or so, and we`ve timed it in the TAFs that way. Main concerns will be erratic winds/heavy rainfall. Needless to say, w/convection developing multiple boundaries, expect frequent updates. && .PREV DISCUSSION... /issued 220 PM CDT Mon Jul 30 2018/ DISCUSSION...As of 2:00 PM CDT Monday...well it has been one of those days. Early this morning it looked like a cold front/ boundary was marching south towards Midland. So was ready to update the fcst to lower temps everywhere. Snyder was 69 around 9 am whereas Midland was at 87. It looked like it would go thru Midland shortly thereafter. So we waited...and waited...and waited some more. Five hours later? It`s still 89 in Midland...and rebounded to 76 in Snyder. Could be a secondary boundary further north. It might very well be one of those forecasts where the extended is easier than the short- term. The hi-res models such as the HRRR and the RAP13 haven`t been doing well at all (to be nice about it). The NAM and the GFS are at polar opposites for Midland with the MET having a pop of 90 tonight whereas the MAV is 34. The ECMWF is closer to the NAM. It seems like the "best model" is the NAM Nest 3 km CAM model. It appears that the cold front will finally move south tonight with an increase in convection. The CAM model has two rounds of convection going thru tonight...one in the evening and another round early Thursday morning as a shortwave drops south. Have pops in for Tuesday as the cold front recedes and dissipates. Have temps a little below normal for Tuesday. Thunderstorms tonight could be strong to possibly severe with strong wind gusts. Locally heavy rain is possible. Starting Wednesday ridge parks itself over AZ. It looks like a shortwave rounding the periphery of the ridge will bring a chance of convection to most of the CWA Wednesday night into Thursday night. Timing is a bit of an issue right now. The ridge spreads east late in the week with easterly flow over the area. Therefore...have left convection confined to the Guadalupe Mtns. Temps from midweek thru the weekend will be near normal...mid to upper 90s with temps near the century mark along the Rio Grande. Strobin && .PRELIMINARY POINT TEMPS/POPS... Big Spring 72 90 71 95 / 60 10 0 0 Carlsbad 71 87 70 95 / 60 40 10 10 Dryden 78 91 73 97 / 30 20 10 0 Fort Stockton 73 88 71 95 / 40 30 0 0 Guadalupe Pass 64 79 67 87 / 50 50 10 10 Hobbs 68 88 67 93 / 50 30 0 10 Marfa 69 82 61 87 / 30 20 10 10 Midland Intl Airport 71 90 70 95 / 60 20 0 0 Odessa 71 90 71 95 / 60 20 0 0 Wink 74 90 70 97 / 60 30 0 0 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...None. TX...None. && $$ 44/12/44
Area Forecast Discussion
National Weather Service Miami FL
853 PM EDT Mon Jul 30 2018 .UPDATE... The 00Z MFL sounding continues to indicate a wet tropical atmosphere in place with 2.04" of PWAT. Abundant moisture could be noted from the surface up through the upper levels with a shallow dry layer at around 400mb. Convection has been waning out the last couple of hours and is expected to diminish further tonight, at least over the interior. As southeast flow develops later tonight, short term models prog showers and isolated storms to re-initiate over the Atlantic waters and push slowly towards the east coast metro region. In the update, decreased PoPs over the interior and increased PoPs along the immediate Atlantic coast. Otherwise, all other variables appeared on track. && .PREV DISCUSSION... /issued 735 PM EDT Mon Jul 30 2018/ AVIATION...Remaining SHRA/TSRA lifting north away from KAPF and vcnty this evening with isold activity over local ATLC. Prevailing SHRA/VCTS at KAPF for another hour, then clearing. Models show more SHRA along east coast sites after 08Z, so have included VCSH after this point. Stronger SE flow 10-13kts tomorrow gets going after 13Z along east coast with VCTS through 19Z-21Z when activity should be west of TAF sites. For KAPF, no Gulf breeze but likely see more southerly flow after 18Z with afternoon convection through end of TAF cycle. PREV DISCUSSION... /issued 407 PM EDT Mon Jul 30 2018/ DISCUSSION... Latest water vapor imagery shows deep tropical moisture moving slowly northward over the Florida peninsula, sandwiched between drier over the Gulf of Mexico and out beyond the Bahamas. This mornings MFL sounding depicted over two inches of PWAT, well above seasonal climatology. Southerly flow will continue to bring deep moisture northward through this evening, accompanied by scattered showers and thunderstorms. With such of saturated atmospheric sounding, with a lack of dry air in the mid levels, strong winds and hail are of little concern. The main threat from this afternoon/evenings activity will be minor flooding of urban areas, as storms begin to train south to north over the same areas. By late this evening, the HRRR and WRF indicate dissipating showers inland, which can be attributed to the loss of diurnal heating. However, as is typical with south southeast flow, scattered showers with isolated thunderstorms are expected to persist over the coastal waters, esepcailly over the Atlantic waters. Tuesday through late week: By Tuesday, mid range models strengthen and expand an area of deep layer high pressure near Bermuda. This feature will act to back winds to southeasterly across our CWA. In addition, drier air is also progged to advect over the area from over the Atlantic. PWAT values will typically range from 1.50" to 1.80" during the next several days, appreciably lower than this past weekend. This pattern will remain unchanged through the end of the week, bringing a chance of showers and thunderstorms to the Atlantic waters and adjacent east coast metro region during the nights and mornings, shifting to the interior and Gulf coast regions during the afternoons and early evenings. Maximum temperatures on Tuesday are forecast in the upper 80s to near 90 along both coasts and lower 90s across the interior, a couple of degrees below normal for this time of year. Similar maximum temperatures are expected for the remainder of the week, rising slightly along the Gulf and western interior, due to the southeast flow pattern. MARINE...Surface high pressure will expand near Bermuda the next several days, with southeast flow becoming dominant across the South Florida coastal waters through the week. Showers and thunderstorms will continue to be possible all week. These may bring locally hazardous marine conditions, including locally rough seas, gusty wind, and possibly isolated waterspouts. && .PRELIMINARY POINT TEMPS/POPS... West Palm Beach 76 90 77 90 / 40 40 40 40 Fort Lauderdale 78 89 79 89 / 40 30 30 40 Miami 77 89 78 89 / 40 30 30 50 Naples 75 89 76 90 / 30 50 20 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && DISCUSSION...27/JT MARINE...27/JT AVIATION...88/ALM
Area Forecast Discussion
National Weather Service Medford OR
837 PM PDT Mon Jul 30 2018 .DISCUSSION... Radar is showing a few returns in Lake county this evening, but it looks like just some virga with none of the nearby RAWS sites reporting precipitation. The forecast appears on track with the dense smoke keeping temperatures well below most of the guidance for Medford and portions of the Shasta valley. That trend will continue for tomorrow. Read the previous discussion below for more information beyond tonight and tomorrow. -Smith && .AVIATION...For the 31/00Z TAFs...Along the coast and over the coastal waters...Areas of IFR cigs/vsbys over the coastal waters are returning to the coast and the coastal valleys this evening. The lower conditions will burn back to the coast again by Tuesday afternoon but the window for VFR Tuesday afternoon could be brief. Over the remainder of the area, mostly clear skies will prevail, but areas of MVFR vsbys and local IFR vsbys due to smoke from numerous wildfires will persist. The one inland area that will be relatively free of smoke will be northern Douglas county. -Bunnag && .MARINE...Updated 800 PM PDT Monday 30 July 2018...Light to moderate northerly winds will persist into Wednesday with high pressure offshore and a thermal trough inland. The thermal trough will redevelop near the coast Thursday into Friday, and this will bring stronger north winds and choppier seas to the area. Small Craft Advisory conditions may develop south of Cape Blanco Thursday afternoon through Friday night. Uncertainty increases beyond Friday, but winds and seas will most likely diminish Saturday and Sunday. -Bunnag .FIRE WEATHER...Updated 100 PM PDT Monday 30 July 2018...The big news of the day is the mention of Lightning Activity Level (LAL) 2 northeast of Crater Lake this evening and southwest of the Silver Lake area. This slight chance of a thunderstorm occurring is very small, with buildups being the most likely scenario today as the smoke could prevent the clouds from building altogether. Otherwise, The smoke has largely kept the inversions going strong all the way to the time of this discussion, but once those inversions break, another hot, dry, and unstable day is expected. In fact, there are still areas of Haines 6 forecast for most of Lake County, south and east Modoc County and southeast Siskiyou county with Haines 5 elsewhere (except for the Cascades where there is mid- level moisture.) Overnight recoveries should continue to improve again tonight, although a few mid to upper level slopes and ridges could still see higher end moderate recoveries. For Tuesday, the area of LAL 2 will expand into Lake County and the Warner Mountains of eastern Modoc County. This slight chance for thunderstorms and build ups is expected after 2 PM. Haines indices will generally be somewhat lower due to the increased mid-level moisture, but many of the West-Side fires will still see haines 5 while Eastern Lake and Modoc Counties could see another round of haines 6. Then, the pattern change will take place on Wednesday. The biggest concern will be the winds as they will become breezy. These winds combined with the still dry surface humidities will create for near critical conditions, especially east of the Cascades (including Modoc County). Will headline for now, but pass along to the next set of eyes to take a closer look as to whether or not any watches need to be issued. Temperatures will be less hot Thursday and cooling into the weekend. The winds will continue to be breezy, but humidities could begin a trend upward. That being said, will need to continue to monitor in case any headlines or products are needed. -Schaaf. && .PREV DISCUSSION... /Issued 502 PM PDT Mon Jul 30 2018/ DISCUSSION... Broad southerly flow aloft has been expanding westward today, as is evidenced in water vapor imagery. Despite this broad southerly flow aloft, flow below a 7kft MSL subsidence inversion west of the Cascades remains generally westerly. Meanwhile, flow is generally southerly now across much of Lake and Modoc counties. The net result still remains that most of the forecast area remains in significant wildfire smoke. The exception to this is across much of the coastal counties inland into the Roseburg area, where air quality remains good. The 18Z HRRR Smoke Model`s Near Surface Smoke forecast looks to be very much on track, indicating smoke continuing to affect mainly the same area as it has been today, with a push from the northwest this evening likely to improve air quality at least a little for some areas west of the Cascades. The Air Quality Advisory has been updated to include Jackson, Josephine, most of Klamath, and portions of Lake County. Visible and other satellite imagery this afternoon show evidence of some weak shortwave activity embedded in the broad southerly flow aloft. Currently, this is primarily resulting in increased mid-high level cloudiness across mainly Modoc and Lake counties. As we head into this evening both the NAM12 and the GFS20 indicate a slight threat for thunderstorm activity, generally indicating areas of enough instability for thunderstorm development, but mostly indicating lower mid-level moisture (around 700MB) to be insufficient for storms to develop. However, it is close enough that it bears close watching, especially about 3 hours either side of 03Z/8PM PDT. The area to keep an eye on remains from about the Trinity Alps north and eastward into the Oregon Cascades and across the east side. What model agreement there is indicates maximum instability from Crater Lake National Park northeastward, and over NW Lake County, mainly near and south of Silver Lake. Therefore, we have a slight chance of showers and thunderstorms mentioned through this evening in those two areas. For tonight through Tuesday guidance continues to show a very slight to slight possibility of thunder. Therefore, we`ve continued a mention of a slight chance of showers and thunderstorms over Lake county and small portions of northern Klamath and eastern Modoc counties for Tuesday afternoon and evening. Despite precipitation being output by the 12Z GFS20 in and near Crater Lake NP tomorrow evening, there is no mention of showers or thunder in the forecast for there because instability from the GFS20 and other models show a stabilizing and drying trend as compared to today. Model guidance has continued to trend toward high confidence in a cooling trend for the remainder of this week into this weekend. In fact, temperatures are expected to be at to a few degrees below normal Thursday through early next week, and there is even a possibility of a little bit of rainfall, mainly along and near the coast and in the Umpqua Basin centered on early next week. Temperatures today were adjusted based on a consensus of the model guidance and normalized 500MB heights from the 12Z GEFS. It`s notable that CPC`s 6-10 day forecast indicates increased probabilities for below normal temperatures over our forecast area and for above normal precipitation for the northwestern portion of the area. This forecast indicates a 5 out 5 level of confidence due to very good model agreement. Looking closer at model differences related to the potential inland penetration of this trough into our portion of the PacNW indicates that energy coming across the Bering Sea this Friday to be a key ingredient. Thus, we`ll have more confidence in the rainfall forecast Friday into Saturday. -Lutz && .MFR WATCHES/WARNINGS/ADVISORIES... OR...None. CA...None. Pacific Coastal Waters...None. $$
Area Forecast Discussion
National Weather Service Missoula MT
240 PM MDT Mon Jul 30 2018 ...Dangerous Heat for lower elevations of north-central Idaho through Tuesday... .DISCUSSION... Temperatures will continue to be on the incline for today and Tuesday as a strong high pressure builds over the area. In addition, the valleys of north central Idaho will struggle to drop below 65 degrees overnight, leading to the continuance of the heat advisory for these areas today into Tuesday evening. Meanwhile, plentiful smoke and haze will be spreading into north central Idaho and western Montana for the next couple of days. This encroaching smoke/haze shield, in addition to increased cloud cover, could keep Tuesday`s maximum temperatures from reaching their full potential. In any case, however, it is still expected to be a hot summer day for most. To prevent heat related illness, it is advised to limit outdoor activity to the cooler parts of the day and provide hydration for people and pets. Beginning Tuesday afternoon, isolated thunderstorms are possible for central Idaho and southwest/west-central Montana that would linger into the overnight period. Showers and thunderstorms are then forecast to increase in coverage Wednesday afternoon and evening. These thunderstorms will be relatively dry, which may pose a threat to susceptible dry vegetation due to lightning. Gusty, erratic outflow winds are also a thunderstorm concern. A dry cold front is anticipated to move into the area on Thursday, producing increased gusty winds that will persist through Thursday night. Temperatures should show signs of cooling for Thursday and Friday, providing noticeable relief from the recent hot temperatures. However, long-range models suggest the return of warm high pressure for Sunday into early next week. && .AVIATION... GOES-16 imagery and the HRRR smoke dispersion forecast continue to show incoming smoke and haze today, spreading from the southwest to the northeast. This influx of smoke/haze will start to degrade mountain visibility at times, potentially creating MVFR conditions. Hot temperatures today into Tuesday will increase density altitude, especially for northwest MT and north- central Idaho airfields. Otherwise, VFR with light winds are anticipated for all TAF sites. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...Heat Advisory until 8 PM PDT Tuesday Lower Hells Canyon/Salmon River Region...Northern Clearwater Mountains... Orofino/Grangeville Region. && $$
Area Forecast Discussion
National Weather Service Nashville TN
905 PM CDT Mon Jul 30 2018 .DISCUSSION... A few clusters of thunderstorms were located over eastern parts of the Mid-State this evening, and were moving off to the northeast. Otherwise, it was mostly cloudy and mild, with 8 pm temperatures in the lower and middle 70s. Have made only minor modifications to the ongoing overnight forecast. Nudged PoPs to the likely category along the Cumberland Plateau, where upper level shear axis will be hanging out for the remainder of the night. Still expect another upper level disturbance, currently back over northern Arkansas and southeastern Missouri, to possibly push a new batch of scattered thunderstorms into our northwestern areas later tonight (after midnight). For areas west of the Cumberland Plateau, will keep overnight PoPs in the 30 to 50% range. 00z OHX sounding showed an unstable air mass, with an LI of -3, CAPE of 1317 J/kg, and PW of 1.69 inches. && .AVIATION... 00Z TAF DISCUSSION. BNA/MQY/CKV/CSV...Scattered convection continues to track across Middle Tennessee as we head into the evening, and it is possible the terminals at BNA & MQY will be affected through maybe 01Z. Afterwards, look for another line of cells to affect the mid state overnight, although the HRRR suggests this activity will dissipate before reaching the Cumberland Plateau. Expect low ceilings & some fog toward morning as a surface low moves across the region. Conditions will likely improve by late morning. However, another round of storms is possible during the afternoon on Tuesday. && .PRELIMINARY POINT TEMPS/POPS... Nashville 71 84 69 86 68 / 50 50 40 20 10 Clarksville 68 83 65 83 65 / 50 30 30 10 0 Crossville 67 79 65 78 65 / 50 60 60 50 30 Columbia 69 83 66 84 66 / 50 50 40 20 10 Lawrenceburg 68 83 66 83 66 / 50 50 50 20 10 Waverly 68 84 65 84 66 / 50 40 30 10 0 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION......19 AVIATION........08
Area Forecast Discussion
National Weather Service Phoenix AZ
543 PM MST Mon Jul 30 2018 .UPDATE... Updated Aviation section. && .SYNOPSIS... The Monsoon High will predominate across the Desert Southwest through early next week, resulting in temperatures a few degrees above normal. Storms will be most favored across the higher terrain east of Phoenix, though there will be a slight chance of thunderstorms across south-central Arizona each day. && .DISCUSSION... Today: It looks like clouds were able to clear out early enough this morning to provide us with sufficient day time heating today. The upper-level ridge continues to meander near southern Nevada, providing us with another day of mid-level easterlies. Sufficient moisture continues to exist across the southern half of the state with PWs ranging from 1 to 2 inches and the greatest moisture existing from Maricopa county westward into southeast California. Currently, scattered storms have already started to develop over the higher terrain of Gila county, with some isolated stronger storms apparent on radar. According to the SPC mesoanalysis page, CAPE values in this region range from 1000 to 2500 J/kg with very little CIN. In addition, DCAPE values in this same region are around 1000 to 1300, so stronger storms that develop will have the potential to produce strong downdrafts. With the steering flowing being out of the east-northeast, expect activity to continue to push westward, with most CAMs indicating an outflow boundary pushing across the western portion of our forecast area, starting in Gila county around 22Z/23, then pushing through the PHX metro somewhere between 00Z to 03Z, then exiting Maricopa county somewhere between 04Z and 05Z. Some of these models also continue to indicate that the outflow boundary could even push further westward into La Paz and Yuma county and potentially as far west as southeast California. So the main question is, will these outflows be strong enough to generate additional storms over the lower deserts? The forecast soundings for PHX, show up to 2000 J/kg of CAPE, however there is a pretty moderate cap so it would take a strong outflow boundary to trigger additional storms across the lower deserts. Most CAMs remain pretty optimistic today and do have thunderstorms over the Phoenix metro, so it`s not completely out of the question today and chances definitely look better than yesterday. Tuesday-Monday: Little change in the pattern is anticipated as the aforementioned Monsoon High persists and meanders across the Desert Southwest. This will generally result in temperatures a few degrees above normal and well below records. Latest NAEFS percentiles indicate low-level mixing ratios near climatology, which will generally favor the Mogollon Rim and higher terrain for storm activity. However, it is possible that scattered thunderstorms will materialize across central Arizona one or two days this week, despite the PoPs near Climo. Latest operational GFS and ECMWF depict a well-defined inverted trough approaching the region late in the weekend or early next week. This will likely enhance the threat for precipitation along with other monsoon hazards including strong winds and blowing dust. && .AVIATION... South-Central Arizona including KPHX, KIWA, and KSDL: Strong storms that are ongoing in Gila County and are beginning to push into far northeastern Maricopa County should at least push an outflow through KIWA and KSDL around 0130Z and possibly KPHX most likely after 02Z. These storms would arrive earlier if they maintained their current intensity and W-SW progress, but some weakening is still expected based on recent daily trends. It is worth noting that more hi-res models, including the most recent HRRR runs and a few of the HREF runs, are pushing at least some of this convective activity into the lower deserts than yesterday. The earlier initiation of storms relative to yesterday makes this more likely as well, so we have added VCTS into KIWA and KSDL from 0130-03Z. We kept VCSH for KPHX since the storms may not be able to hold together that far west assuming the outflows push ahead of the storms. However, the strongest thunderstorm cells near Payson may be able to push into lower deserts and hold together after sunset due to a shortwave that may be rotating around the ridge aloft. If this occurs, we will amend as needed. Otherwise, expect easterly winds to return late overnight with the normal diurnal progression to westerly by early afternoon tomorrow. Thunderstorm chances for the lower deserts will be lower tomorrow without the additional shortwave forcing. Southeast California/Southwest Arizona including KIPL and KBLH: Aviation impacts are generally not expected through tomorrow afternoon aside from some midlevel clouds at KIPL and high clouds at KBLH. There is a low chances of thunderstorms making it into La Paz or Yuma Counties that may push a few outflows into the TAF sites, but chances are too low to include at this time. Apart from outflows, southeasterly winds at KIPL and southerly winds at KBLH below 10 knots will be favored. Aviation Discussion not updated for amended TAFs. && FIRE WEATHER... Thursday through Monday: Anticipate a familiar Monsoon weather pattern this week with storm activity occurring mainly over the higher terrain of Arizona with only slight chances over the lower deserts. Storm chances depart from southeast California and southwest AZ on Friday through Monday as atmospheric moisture content aloft declines somewhat. Otherwise, minimum humidities will remain above 15% on the lower deserts (upper teens to mid 20s; mid 20s to mid 30s higher terrain). Overnight recovery will remain good. Apart from thunderstorms, winds will be light except for typical afternoon and evening breeziness. && .SPOTTER INFORMATION STATEMENT... Skywarn amateur radio Nets may need to be activated for this afternoon and evening. Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ DISCUSSION...Hernandez AVIATION...AJ FIRE WEATHER...AJ
Area Forecast Discussion
National Weather Service Charleston WV
726 PM EDT Mon Jul 30 2018 .SYNOPSIS... Instability and moisture return to the area, resulting in several chances of showers and thunderstorms this week. The weather settles down a bit, but remains muggy, late week. && .NEAR TERM /THROUGH TUESDAY/... As of 720 PM Monday... Made some tweaks to POPs tonight into tomorrow based on recent radar trends this evening, and then high res guidance tonight into tomorrow. Main changes were to add POPs this evening where showers are ongoing, and then used the HRRR to carry them forward. Slowed down likely POPs a bit for Tuesday morning. As of 232 PM Monday... Models indicate that a developing sfc low pressure will lift north across TN and KY tonight, and into OH by Tuesday. An associated warm front will lift slowly north tonight to keep mainly showers going through the area. Nighttime pcpn activity should be less intense than during the afternoon. Hi resolution models suggest a lull in pcpn activity overnight, but increasing by 12Z Tuesday across southeast OH pushed by a cold front. At the same time, an H500 trough will cross the area bringing some upper level forcing to maintain pcpn activity tonight into Tuesday. The heaviest precipitation is expected Tuesday morning across southeast OH and northeast KY counties. A marginal risk for excessive rainfall has been placed by WPC in these areas. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 310 PM Monday... We remain in a moist southerly flow, under a moderately unstable atmospheric regime into Thursday. 5H trough lifts and shifts slightly east by midweek with some de-amplification of the pattern. Sensible weather will primarily be driven by convective activity, so there is some model uncertainty in handling the finer details. Diurnal heating will play a significant role in daytime development with nocturnal activity lingering due to mid upper level disturbances which will be present under this southwest flow regime. After a brief respite on Wednesday, channeled vort maxima are progged to ride north along the Appalachian mountains Wednesday night into Thursday. Rainfall amounts will need monitored throughout the period, especially in the mountains. && .LONG TERM /FRIDAY THROUGH MONDAY/... As of 310 PM Monday... Mid to upper flow pattern transitions to zonal pattern as 5H trough weakens and lifts away from the northeastern United States. The unsettled weather pattern will continue with seasonable summer temperatures. Used central guidance for PoPs and temperature forecast, leading to little overall changes to ongoing forecast trends. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... As of 720 PM Monday... Have some showers and thunderstorms across the forecast area now, but not expecting any of these to have much impact on TAF sites. Could get a shower at PKB, CRW or HTS, but not enough confidence to give any restrictions at this time. We keep clouds and flow around tonight, so did not go with much fog outside of EKN. Showers and thunderstorms will be on the increase starting again Tuesday morning. IFR possible as any storm passes over a TAF site. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z WEDNESDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: May see more widespread IFR in fog tonight. Timing of showers and storm tomorrow may vary. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09 EDT 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 CRW CONSISTENCY H H H H H M M L L L L L HTS CONSISTENCY H H H H H H M M H M L L BKW CONSISTENCY H H H H H H M H H H H H EKN CONSISTENCY H H H H M H M H H L L L PKB CONSISTENCY H H H H H H H H H M L L CKB CONSISTENCY H H H H H M M H M L L L AFTER 00Z WEDNESDAY... IFR possible in showers and thunderstorms through Thursday, mainly during the afternoons and evenings. IFR in post-rain fog and stratus will be possible each of these nights. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...KMC/ARJ NEAR TERM...ARJ/MZ SHORT TERM...KMC LONG TERM...KMC AVIATION...MZ
Area Forecast Discussion
National Weather Service Blacksburg VA
1053 PM EDT Mon Jul 30 2018 .SYNOPSIS... East to southeast winds between high pressure to the northeast and low pressure to the southwest will pull in increasingly warm and muggy tropical air back into the mid- Appalachian region for at least the next several days. The threat for more widespread showers and thunderstorms will gradually increase through the period as a weak front approaches from the west and then stalls over or near the area through late in the week. && .NEAR TERM /THROUGH TUESDAY/... As of 1045 PM EDT Monday... Band of moderate to heavy showers and isolated thunderstorms was aligned along the southern Blue Ridge late this evening. Expect overall slow southeast movement of main axis of precipitation but will take until around 4AM for the heavier rainfall to weaken in coverage and intensity. Have adjusted probability of precipitation for these trends. Have made minor adjustments to overnight lows with little to no cooling for the rest of the night. Deeper moisture will enter the mid-Atlantic on Tuesday as the upper trough deepens across the upper Mississippi Valley, resulting in an increasingly southerly wind shift as high pressure moves offshore. Believe coverage of showers and thunderstorms will increase during late morning as heating increases: spotty at first and then filling in during early afternoon and becoming more organized. With precipitable water values increasing into the 1.7 to nearly 2.0 inch range and CAPEs again rising to 1500+J/Kg, heavy rain will be the main concern. Would not be surprised for some storms to produce 2 to 3 inches rainfall amounts locally, possibly more, especially along and east of the Blue Ridge where surface convergence appears stronger. Will let the overnight shift have a look at evening synoptic data to determine if/where a flash flood watch is appropriate. Widespread clouds/scattered rain will hold afternoon temperatures in the upper 70s/low 80s. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... As of 145 PM EDT Monday... We are offering very limited change to the forecast that was in place for this time period. A very generous plume of moisture is expected to advect northeast into the region from the eastern portion of the Gulf of Mexico in advance of a amplifying upper level trough positioned over the Mississippi River Valley. NAEFS Percentile output is still offering 90-99 percent values on elements such as precipitable water and 850mb specific humidity and the V- component of the wind across our region Tuesday afternoon through Wednesday. This suggests high confidence in widespread coverage of showers and storms, with locally heavy rain likely. While the percentile numbers are not as high on Thursday, the overall synoptic pattern does not change that much, so that the weather should be similar to that of Wednesday. Thanks to abundant cloud cover and the expected precipitation, low temperatures are forecast to be slightly above normal and high temperatures will be slightly below normal. Forecast confidence in the above portion of the forecast is moderate to high regarding the overall synoptic pattern and temperature forecast. Confidence in a greater than normal coverage and amounts of precipitation is high. We will need to monitor daily rainfall amounts leading into the middle of the week to assess where any region may become more prone to flash flooding for any potential watches or warnings. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... As of 1215 PM EDT Monday... The weakening upper trough over the Mississippi River valley is expected to continue to do just that, dissipate, all while an upper high off the southeast U.S. coast retrogrades closer to the coast by the start or middle of the weekend. While our area will lose the upper level dynamics associated with its location on the eastern flanks of the trough, we will maintain a decent low level moisture feed off the eastern parts of the Gulf of Mexico. This will allow for a transition of our precipitation becoming progressive diurnally based, and less organized as we head into the weekend. There will also be a trend toward warmer temperatures as heights build over the region and we lose the widespread coverage of cloud cover and precipitation. Our weather picture heading into early next week gets a bit more uncertain. The Canadian solution wants to bring the center of the upper high overhead and keep the better dynamics north of the region along the northern jet which is progged to become zonal over the U.S/Canadian border. The GFS is content to keep the upper high just off the southeast U.S. coast all while a shortwave trough dips south into the the mid-Atlantic region. The European solution is similar to the Canadian in that it keeps the best dynamics to our north near the U.S/Canadian border, but is more nebulous on just where the center of the upper high progresses and/or there is not just one main center, but perhaps as many as three bull`s eye of high pressure, all across the southeast U.S. The European solution is close to a compromise of the other two solutions, and represents what would be close to typical early August summer pattern for the region with near normal temperatures and diurnally based convection. Our forecast will reflect this scenario for Monday. Forecast confidence in the above forecast scenario is moderate heading into the weekend, with levels dipping more to the low to moderate side for the Monday portion of the forecast. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... As of 745 PM EDT Monday... Band of scattered to numerous showers and thunderstorms had developed from KLYH to KROA to KTNB this evening. This band of showers and thunderstorms will drift southeast through midnight and gradually weaken but not completely dissipate as indicated on the last few HRRR runs. Some wind gusts up to 25 knots with a few of these storms. Visibility also reduced to MVFR/IFR due to very heavy rain. Overnight, expect widespread MVFR to IFR stratus to redevelop. Additionally, may see areas of MVFR fog develop, especially where significant rainfall occurred. Expect a return of scattered showers and thunderstorms on Tuesday afternoon as a strong upper level disturbance approaches from the south. Do not expect much improvement in ceilings from the morning into the afternoon. Average confidence on areal coverage of precipitation and above average confidence in formation of stratus overnight. Extended... Tropical airmass is expected to remain over the forecast area through the longer-range terminal forecast period with widespread flight restrictions often to remain in the MVFR range or lower - especially in/near increasing threat/coverage of showers/thunderstorms as a frontal system approaches from the west and then stalls over the area by midweek. Therefore, any VFR flight is expected to be relatively short-lived, not widespread, and mainly confined to afternoon hours each day outside of any areas of precipitation. Confidence is moderate to high, both temporally and spatially throughout the extended period. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...JH/NF NEAR TERM...AMS/NF SHORT TERM...DS LONG TERM...DS AVIATION...AMS/NF
Area Forecast Discussion
National Weather Service Springfield MO
606 PM CDT Mon Jul 30 2018 .SHORT TERM...(This evening through Tuesday) Issued at 205 PM CDT Mon Jul 30 2018 Near term concerns are thunderstorms over our southeast KS and far southwest MO counties. A shortwave over IA into KS will continue to move southeast into MO Tuesday. Short term guidance seems to have a good handle on developing convection over over the four state KS-MO-OK-AR area. Lift is being enhanced by an upper level jet streak nosing into the area ahead of the shortwave axis. Progged instability of the HRRR is fairly modest, about 800-1200 j/kg mlcape and around 1500 j/kg mucapes. Increased 0-6km vertical shear could support some storm organization, but lower level shear is much weaker. The SPC marginal risk looks good for that area for now and will continue to watch radar trends for wind/hail risk. Some showers/tstms may last into the evening hours, but given the weaker overall instability, activity should gradually wane as the evening wears on. Wouldn`t be surprised if there are at least some isolated showers through the night given the approach of the upper wave. Some guidance is hinting at some fog/low cloud development once again. The signal isn`t overwhelmingly there, but the best chances look to be in far southern MO. Additional diurnally driven showers/tstms will be possible Tuesday as the shortwave axis moves through. The best chances look to be the eastern cwfa. Again, instability isn`t terribly overwhelming and vertical shear will be more limited versus today so the severe storm risk looks low. .LONG TERM...(Wednesday through Monday) Issued at 222 PM CDT Mon Jul 30 2018 The shortwave axis will shift slowly off to the east with drier weather expected through midweek. Warmer temperatures with the eastern extension of upper level ridging over the southwest U.S. will occur for us later in the week and over the weekend. No big chances for rain through Monday are indicated by medium range guidance. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 545 PM CDT Mon Jul 30 2018 Convection currently making its way across the southern portion of the area affecting all of the TAF sites. As this convection traverses the area...will see occasional MVFR conditions. Activity should be out of the area between 04-06z. Next concern is fog overnight especially where rain fell today. Have lowered visibilities at all TAF sites to MVFR from 09-14z and could see some IFR conditions at KBBG around sunrise. VFR conditions can be expected from mid to late morning through the remainder of the period. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ SHORT TERM...DSA LONG TERM...DSA AVIATION...Gaede
Area Forecast Discussion
National Weather Service San Diego CA
155 PM PDT Mon Jul 30 2018 .SYNOPSIS... The weather pattern will be relatively unchanged through Wednesday with warm, humid weather and chances for afternoon thunderstorms over the mountains and high deserts. The monsoonal flow will decrease later this week as high pressure aloft builds over Southwest. Marine layer clouds will return to the coastal areas each night. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... The absence of the marine layer this morning resulted in rapid warming in the coastal zones, and by 11 am temperatures were in the 80s near the coast, and in the low 90s in the valleys. The onset of the afternoon sea breeze and the return of low clouds to the beaches this afternoon slowed the warming. The San Diego Airport was 84 degrees at Noon, then fell to 81 at 1 PM. The marine layer will return tonight and that will keep the coastal areas cooler tomorrow. The visible satellite showed low clouds over the coastal waters and they will spread a few miles inland by morning. Farther east over the mountains the convection was limited to flat cumulus over the mountains. Although the atmosphere remains warm and humid, it`s more stable than yesterday when scattered thunderstorms formed over the mountains. The precipitable water is still very high (1.78" on the 12Z NKX sounding), but SBCAPE today (983 J/kg) was half what it was yesterday, and the forecast soundings showed a stable layer at 700 mb and at 425 mb. This is reflected in the output from the WRF and HRRR models that forecasted less thunderstorm coverage this afternoon. Isolated convection is still possible along the sea breeze/desert wind convergence zone over the mountains, but will be less widespread than yesterday afternoon. Tuesday and Wednesday will be a lot like today with very little change in the airmass. It will continue to be warm and humid all areas with a chance for thunderstorms over the mountains. Thursday through Sunday...High pressure aloft will shift southward slightly as a trough of low pressure deepens along the west coast. The GFS and ECMWF are both converging toward this solution. This will continue the drying trend into next weekend but with mostly minor day to day differences with temperatures into next weekend. Expect a greater return of night and morning coastal low clouds and fog through the period. && .AVIATION... 301930Z...Coast/Valleys...Patchy low clouds with bases 900-1200 ft MSL developing along the beaches at this hour could impact KSAN and KCRQ at times this afternoon, but confidence is low. After 06Z, chances improve for cig impacts at the three Coastal TAF sites but timing is uncertain. Elsewhere, SCT-BKN clouds at or abv 15000 ft MSL with unrestricted visibility through tonight. Any low clouds that move in overnight will likely clear to the coast by 16Z Tuesday. Mountains/Deserts...SCT-BKN clouds at or abv 10000 ft MSL with unrestricted visibility through tonight. A few showers and thunderstorms will develop this afternoon and evening. Strong updrafts and downdrafts will be possible near thunderstorms, along with surface wind gusts to 40 KT. && .MARINE... No hazardous marine weather is expected through Friday. && .FIRE WEATHER... Warm and humid again Tuesday and Wednesday with isolated afternoon and early evening thunderstorms over the mountains and high deserts. The monsoon weakens Wednesday through Friday, but it will remain very warm through the end of the week. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC/FIRE WEATHER...Moede AVIATION/MARINE...PG
Area Forecast Discussion
National Weather Service Shreveport LA
1019 PM CDT Mon Jul 30 2018 .UPDATE... To tweak pops and weather a bit for the overnight hours. && .SHORT TERM... Skies are partly to mostly cloudy with just a couple of cells on radar active over our southern tier of counties and parishes at this time. The new 00Z nam is still looking promising for some rain, but hopes of a good nocturnal push may have been dashed by the outflow earlier over our area and others likewise across OK/AR limiting development so far. However, the clouds are gathering and small new cells are cropping up in SE OK and a few thunderstorms in the northern part of OK closer to the potent short wave dropping into the long wave pattern trough over the plains now. The HRRR continues to look dismal for the most part and has for the last 6 hours of rapidly refreshing, but we will see what happens with our 1.67 PWAT. The winds aloft will dig in overnight and radar should be busy after midnight and through daybreak for the most part. The cold front will usher out the moisture during the day and push what ever does manage to develop rain wise along with what`s left of the muggy air. /24/ && .PREV DISCUSSION... /issued 757 PM CDT Mon Jul 30 2018/ AVIATION... For the ArkLaTex, still lots of fair wx cu milling about and a boundary has triggered some new development over deep E TX to Toledo Bend moving S/SEward. The next TS development will occur tonight in OK as a cold front and potent upper level low swing SE in the pattern. We are expecting TS development overnight as this front moves toward the area. VCTS in TAFS will be amended w/ tempo groups as needed for wind/vsby. We should clear out early with N winds 10KT. Aloft we will keep W20-50KT for flight levels. /24/ PREV DISCUSSION... /issued 405 PM CDT Mon Jul 30 2018/ SHORT TERM.../Tonight through Tuesday Night/ The last of the sct convection along the old outflow bndry from the morning MCS has exited the region into Cntrl LA along the MS River. However, the visible satellite imagery does indicate some agitated cu developing over portions of Deep E TX into Wcntrl LA, where the afternoon sfc analysis indicates a sharp theta-e axis from the original cold pool which has served as a lifting mechanism with strong afternoon heating within a moderately unstable air mass. With the 12Z progs not initializing well on the original cold pool/outflow bndry, and the HRRR also having problems with the placement of this bndry/convection initiation, have inserted low chance pops this evening over these areas, buffering to slight chance closer to the I-20 corridor this evening. However, our primary focus will be upstream, where the water vapor imagery depicts sharp troughing diving SE across Nrn OK attm, where sct strong to severe convection has developed over NE OK that was largely unaffected from this morning`s MCS. While this convection should weaken this evening with the loss of heating, and as it encounters an increasingly stable air mass mainly S of I-40, the short term progs continue to suggest sct convection developing over extreme SE OK/NE TX/SW AR late this evening and eventually spreading ESE across the remainder of the region as large scale ascent increases ahead of the positive tilt trough. Have continued mid chance pops mention this evening for the I-30 corridor, before increasing pops to high chance/likely after 06Z S of I-30 across E TX/N LA. Dry slotting aloft will quickly entrain E beneath the trough Tuesday morning, with the convection quickly diminishing across the region from late morning into the afternoon with the associated weak cold fropa. Have continued likely pops Tuesday morning for Lower E TX and N LA, before tapering pops off to slight chance/chance during the afternoon. Should see some cu cigs eventually fill in behind the trough and weak cold front, which should actually hold max temps to near or just below 90, a welcome change to the persistent heat wave (away from the convection). Cigs should eventually clear Tuesday evening, giving way to slightly cooler and drier conditions Tuesday night. /15/ LONG TERM.../Wednesday through Monday Night/ High pressure and a drier airmass movg into the region by mid week. Aftn temps in the lower to middle 90s will be tempered by lower humidity as dewpoints will range thru the 60s for the remainder of the workweek. Upper trough over MS river valley will begin to stall out as it digs swd. Isold to scattered mostly diurnal convection can be expected along this trough axis and exact positioning will dictate amount of convection in cwa. But generally speaking, expect chance pops near the river valley and isold for much of rest of area thru the wknd and likely beyond, and along with that, expect dewpoints to rise into lower to middle 70s as daytime temps continue in the middle to upper 90s. /07/ && .PRELIMINARY POINT TEMPS/POPS... SHV 74 88 69 92 / 60 60 0 0 MLU 73 85 68 91 / 60 70 10 10 DEQ 68 86 63 90 / 40 20 0 0 TXK 70 87 67 90 / 50 40 0 0 ELD 71 85 67 90 / 50 50 10 0 TYR 72 90 69 92 / 60 40 0 0 GGG 73 88 68 91 / 60 50 0 0 LFK 74 89 69 93 / 60 60 10 0 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 24/15/07
Area Forecast Discussion
National Weather Service Sacramento CA
339 PM PDT Mon Jul 30 2018 .SYNOPSIS... Smoke will help to keep daytime temperatures cooler the next couple of days. Then a gradual decrease in high temperatures mid week returning to near average. && .DISCUSSION (TODAY THROUGH WEDNESDAY)... Main concern for the short term period continues to be wildfire smoke. Latest satellite imagery indicates smoke and haze impacting interior NorCal as several wildfires continue to burn across the region. Current temperatures are running a few degrees cooler compared to yesterday`s across the northern / central Sacramento Valley given areas of smoke and cloudiness. Highs across the southern Sacramento and northern San Joaquin valleys are running a few degrees warmer. Upper level ridge has continued to push east as trough approaches the PacNW. Temperatures are anticipated to remain a few degrees above normal through the forecast period. However, wildfire smoke could result in cooler temperatures, especially where wildfire smoke is thicker. Valley highs will range from the mid 90s to low 100s. The hottest spot will be the northern Sac Valley, where moderate heat risk could impact sensitive groups through Tuesday. HRRR smoke forecast indicates some relief across the Delta influenced areas this evening as the Delta breeze kicks in. Latest forecast shows similar smoke conditions developing by Tuesday afternoon throughout the valley and mountains. Zonal flow develops by midweek as the upper level ridge continues to push to the east, bringing a slight cooling trend with highs returning to near normal although the wildfire smoke will likely continue to make for a difficult temperature forecast. Guidance suggests monsoon moisture pushing northward. However, thunderstorms could likely remain outside of the forecast area. && .EXTENDED DISCUSSION (Friday THROUGH Monday) Upper level ridging expected to be flattened at times by disturbances. Wildfire smoke could bring cooler temperatures if it remains widespread. Dry weather is expected to continue through the extended period at this point. Model guidance is hinting at a fairly strong trough early next week, which could bring the potential for some precipitation into Norcal mainly over the northern mountains. Confidence is very low at this point, so will have to wait and see if there is any continuity/consistency in future model runs. Upper trough is expected to bring much cooler temperatures across the area, with Valley highs potentially in the upper 80s to mid 90s so have adjusted temperatures accordingly. && .AVIATION... Lcl MVFR/IFR cigs/vsby in HZ and FU in Cntrl Vly nxt 24 hrs fm fires. Lcl SWly sfc wnd gsts to 25 kts thru Delta and W-NW in favored canyons/ridges of Cstl Mtns aftns and ovngt. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$