Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/17/22

Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
616 PM CDT Fri Sep 16 2022 ...New AVIATION... .SHORT TERM... (Tonight through Saturday night) Issued at 200 PM CDT Fri Sep 16 2022 Latest GOES-16 visible satellite imagery shows partly cloudy skies across the region early this afternoon as the morning low clouds and patchy fog have mixed out. Warm and humid conditions characterize the forecast through the short term with afternoon highs in the low to mid 90s and peak heat indices near or in excess of 100 degrees for areas primarily along and east of I-35. There will also be enough moisture this afternoon and again during Saturday afternoon for isolated to widely scattered showers and thunderstorms with the seabreeze for areas primarily within the coastal plains. However, couldn`t rule out a stray shower or two early this evening in the Hill Country as illustrated on recent HRRR runs. Majority of the activity should dissipate around or soon after sunset with the loss of daytime heating. Very muggy conditions will again be expected tonight and again Saturday night with overnight lows generally in the low to mid 70s. Expect the return of low stratus from the late overnight into the morning both tonight and again on Saturday night with the humid conditions. While patchy fog cannot be ruled out, the latest short term model guidance indicate less of a signal for fog as compared to this morning. && .LONG TERM... (Sunday through Friday) Issued at 200 PM CDT Fri Sep 16 2022 Conditions trending more hot and stable over the weekend continue on through much of next week. Model trends are showing the large upper ridge strengthening and shifting slightly more over TX through the next week, whereas earlier runs had allowed for some slightly more Gulf influenced air over the region. The initial days of the long term have continued high low level humidity pooled over the region, and this me make for a couple days of uncomfortable heat index values over 100 degrees over most areas east of I-35. With the upper ridge trends shifting southward, the mid week focus should transition to lower dew points and ambient temperatures beginning to catch up at the expense of the heat index. Few areas are expected to see 100 degrees maxes through Wednesday, but as dprog/dt analyses depict the upper high shifting south to cover more of TX, the likelihood of us drying out increases, along with increasing diurnal temperature ranges. Run to run trends of the MOS guidances are now sending temperatures upward later in the week, with more Central TX/I-35 corridor locations potentially reaching the century mark if the ECMWF position of the mid level ridge verifies for Thursday. A quick look at records for mid September would suggest that we stay below record levels, and this is a reminder that the subtropical heat waves can be quite potent all the way through the end of this month. && .AVIATION... (00Z TAFS) Issued at 612 PM CDT Fri Sep 16 2022 Main concerns for the forecast revolve around IFR ceilings developing after 10Z at SAT/SSF and the possibility of IFR ceilings at AUS as well. Expect winds to remain somewhat elevated at around 10 kts through midnight before dropping off quickly by 2-3 am. Ceilings should respond with the drop in wind as ample low level moisture remains in play through the night. VFR ceilings should return by 16-17Z Saturday morning. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 75 95 74 95 / 10 10 0 10 Austin Bergstrom Intl Airport 73 94 72 95 / 10 10 0 10 New Braunfels Muni Airport 74 95 72 97 / 10 10 0 10 Burnet Muni Airport 73 93 72 94 / 10 0 0 0 Del Rio Intl Airport 75 94 76 94 / 0 0 0 10 Georgetown Muni Airport 74 94 73 95 / 10 10 0 10 Hondo Muni Airport 74 95 74 95 / 0 0 0 10 San Marcos Muni Airport 73 94 73 96 / 10 10 0 10 La Grange - Fayette Regional 74 94 73 95 / 10 20 0 10 San Antonio Intl Airport 75 94 75 94 / 10 10 0 10 Stinson Muni Airport 76 95 75 96 / 10 10 0 10 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...Brady Long-Term...Oaks Aviation...Morris
Area Forecast Discussion
National Weather Service Grand Forks ND
1012 PM CDT Fri Sep 16 2022 .UPDATE... Issued at 1009 PM CDT Fri Sep 16 2022 500 mb short wave is lifting north and the last of the rain and drizzle is coming to an end in the far northern fcst area near Manitoba border. Sfc low is between Cavalier and Hallock. Some light fog is noted in NE ND/NW MN and kept idea of some additional fog forming overnight. To what degree in terms of low vsbys is uncertain. Cloud clearing trend is advancing north quite quickly and more than prev thought. Clearing into Lisbon, just south of Fargo to near Fergus Falls at 03z. Will update grids for sky cover but the rest was updated about 02z for fog. UPDATE Issued at 706 PM CDT Fri Sep 16 2022 Rain area is lifting slowly north and over the far northern RRV and will move into Manitoba and exit the area completely by midnight. Low clouds will remain, though some low level drying will spread north out of South Dakota into parts of E ND/WC MN. Some clearing is possible in SE ND/WC MN overnight, but chances are more likely clouds will hold. Maintain some overnight/Sat AM patchy fog potential. HRRR and CONSHORT vsby forecasts indicate low vsbys not a widespread issue, at least as forecasted currently. && .SHORT TERM...(This evening through Saturday night) Issued at 213 PM CDT Fri Sep 16 2022 IMPACTS... 1.) For the rest of today, showers will continue to linger in the northern Red River Valley. Some areas of patchy dense fog, with visibilities falling as low as a quarter-mile, are possible. 2.) Rain showers, and a few thunderstorms, will arrive once again tomorrow morning and last into the afternoon. These showers/storms should exit the area in the evening hours. 3.) A highly conditional threat for severe weather exists tomorrow in west-central Minnesota. Severe thunderstorm chances will heavily depend on destabilization of the environment tomorrow afternoon. Should severe storms arise, all hazards are possible. METEOROLOGICAL ANALYSIS... The extratropical cyclone we are dealing with continues to spin over the region. Surface observations at 19z indicate the surface low centered somewhere between Oslo and Thief River Falls. Showers continue on the backside of the surface low in the northern Red River Valley. Additionally, patchy areas of dense fog have arisen, although based on surface observations and webcams, fog appears to be significantly isolated (namely primarily in the city of Grand Forks and surrounding areas). It is unclear when this fog will diminish at this time, as fog has continually gone up and down in visibility. With the ground remaining as saturated as it is and no real signs of a change in low level moisture content, it may persist for several more hours. Showers will begin to diminish tonight as the primary surface low exits the area tonight. This will provide for a brief reprieve in precipitation, although cloud cover will persist ahead of the next shortwave trough currently spinning over the intermountain west. This trough is progged to deepen as it exits in lee of the Rocky Mountains. Ahead of this shortwave trough, solid warm air advection will exist across much of the area Saturday morning, inducing broad scale isentropic ascent. Given the strong moisture content of the airmass, it is anticipated that this will cause showers to arise across the area, and at a minimum continued cloud cover over the area. MUCAPE values appear to be mostly isolated to west central Minnesota, where the greatest thunderstorm risk will exist. Nonetheless, on the North Dakota side of things, there is the potential for some rumbles of thunder (although most thunder would be isolated to the southeastern parts of our CWA in Minnesota). Showers and storms should exit the area tomorrow evening and overnight. REGARDING SEVERE RISK TOMORROW... A highly conditional severe weather risk arises tomorrow afternoon. As stated in the 1730z SPC update, Lakes County has been upgraded to a SLIGHT risk for severe weather. All hazards appear to be in store for us if and only if there is enough destabilization to facilitate thunderstorms. In advance of the aforementioned shortwave lee trough, strong isentropic ascent will be ongoing across much of the area. Additionally, southerly flow in advance of the surface cyclone should allow some moist unstable air to advect into western Minnesota. A very tight theta-e gradient does exist with this surface cyclone, and various ensemble guidance seems to struggle with the location of this gradient. At the moment, the range of potential outcomes indicates the gradient getting as far north as Clay County/Becker County and as far south as outside of the CWA. Unfortunately, most of the severe weather risk will be heavily tied to this theta-e gradient, as this will likely play a role in the majority of instability for any parcel of air. Mid-level lapse rates are still quite pathetic, ranging from 6-7 K/km thanks to the ongoing moisture content of the atmosphere. This is where the issue of destabilization comes into play. With the ongoing isentropic ascent across the area, it seems feasible that clearing may be a struggle in the regions around the surface warm front. Having said that, forecast soundings do indicate a very highly sheared environment, with 0-6km shear approaching 60 knots. In addition, solid veering within the lowest 1-2 kilometers of the atmosphere does increase streamwise vorticity quite substantially. As such, it does seem possible that supercells may be in play tomorrow afternoon. Moreover, given the close proximity to a theta-e gradient, ambient surface vorticity may exist. This lends credence to all hazards being potentially in play tomorrow afternoon, with hail up to 1.5", winds up to 60mph, and a tornado or two possible. Again, all of this is conditional on location of the surface theta-e gradient and the amount of destabilization, both of which are still very uncertain at this time. Certainty will increase as we approach tomorrow afternoon. .LONG TERM...(Sunday through Friday) Issued at 213 PM CDT Fri Sep 16 2022 End of the weekend and into next week flow aloft turns zonal as a ridge continues to break down in the central and southern United States. As this happens shortwaves are able to translate across the northern plains. Chances for rain linger throughout the long term, with the two most notable signals in the early and middle portion of the next work week. These signals are associated with a system moving out of the Pacific Northwest. It shifts through the northern Rockies along the zonal flow and brings a warm front Monday into Tuesday. As this happens rain chances increase across the region. Temperatures also turn warmer, with highs in the mid to upper 70s. The warmth doesn`t last long as the cold front sweeps through Tuesday into Wednesday drastically bringing down temperatures for the middle to later portions of next week. Along the front there is the possibility of a few thunderstorms as CAPE and shear profiles are sufficient (500-1000J/kg of CAPE, 25-30kts shear) for thunderstorm development. The strength of these storms are in question as guidance continues to struggle with their development. None the less, there does exist the chance for some thunderstorms Tuesday into Wednesday along the front. Strong NW Flow behind the cold front helps to bring temperatures down Wednesday through Friday, with highs barely reaching the upper 50s to lower 60s. Morning lows near the end of the week are reaching down into the mid 30s for NE ND and NW MN which increases the chance for frost/freeze in the morning. This will be monitored as guidance suggests a 10-30% chance some areas could reach the freezing mark or dip below it end of next week. We will continue to monitor the chance for thunderstorms early next week and the drastic change in temperatures middle to later next week for any frost or freezes. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 706 PM CDT Fri Sep 16 2022 Aviation forecasts are a mix of flight categories. IFR cigs likely to hold NE ND and far NW MN but some rises into the lower MVFR range likely SE ND/WC MN tonight. Patchy fog but widespread low vsbys in fog not anticipated. Saturday will see showers and t-storms move northeast across the southeast 3/4 of the region. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Riddle SHORT TERM...Perroux LONG TERM...Spender AVIATION...Riddle
Area Forecast Discussion
National Weather Service New Orleans LA
629 PM CDT Fri Sep 16 2022 ...New AVIATION... .SHORT TERM... (This evening through Saturday night) Issued at 148 PM CDT Fri Sep 16 2022 Starting out with a regional synopsis overview, we remain under the influence of surface high pressure dominating the eastern third of the US. Aloft, this high remains supported by large- scale, broad ridging extending into the Great Lakes which will steadily continue to drift east and crawl the surface high, downstream of the ridge axis more towards the New England coastline. What this means for us is overall influence of the ridge will lessen with time. Meanwhile just to our south, what was left of the original frontal boundary that passed through several days ago has lost frontogenetic characteristics and displays more of a broad moisture gradient over the northern Gulf. Within the deeper 1.6-1.7"+ PW rich moist airmass over the southern Marine zones continues to support scattered convection. As discussed yesterday, this convection continues to struggle to pierce through drier continental air still parked in place over land areas, extending down into parts of coastal SE LA where overall total PW remains <1.2". While slight northward moderation will continue today as we lose influence of the ridge, still we`ll continue to see the drier airmass win over late this afternoon/tonight before we decouple later this evening with very little, if any PoP coverage for land persisting. Will continue to see a few scattered showers and storms tonight across Marine areas, but overall anticipating a calm and dry night. Main modifications for early Saturday remains to be a hedge towards a blend of deterministic NBM and NBM 25th percentile MinT`s but backed off the degree of lower nudge given surface dewpoints slowly starting to drift north reaching near the I-10/12 corridor. HRRR model soundings illustrate the increase in dewpoints after 06Z for ASD, west to near BTR offsetting the surface radiational inversion which may keep MinT`s closer to deterministic, just will need to monitor the degree of low-level moisture return and how it will impact temperatures around daybreak. Saturday is looking nice to start yet again with some low-level clouds around. Main focus will be the continued return of low- level moisture drifting north adding to that old familiar more humid feel to the air. Gulf moisture return continues to deepen throughout the late morning and afternoon revealing a more moist low-level mixed profile. However, this ascending moist layer remains sandwiched right underneath the residual dry air in the H7 to H5 layer owing to a persistently warm mid-level thermal profile by compressional warming. In turn, we see some positive bouyancy revealed above the LFC to base of the inversion but very little, if any available energy above the inversion. This supports a shallow Cu field and might be enough available energy to maintain showers and perhaps a few rumbles of thunder north to around the I-10/12 corridor. Did not made noticeable adjustments to PoPs this go around as recent NBM guidance is looking reasonable, but did back off the extent of thunder being mentioned given the shallow available energy in the cloud layer. The north/westward extent will remain limited as residual dry continental air will remain in place, revealing low PoPs for this region. But overall, a passing shower or two can`t be ruled out for mainly coastal areas during the day. Marine convection may persist into parts of the overnight hours but should see a reduction in activity once we lose sfc heating and decouple revealing a mostly Saturday night. && .LONG TERM... (Sunday through Thursday night) Issued at 148 PM CDT Fri Sep 16 2022 We`ll continue to see persistent scattered shower and storm chances along the coast and adjacent marine areas on Sunday, with little change other than perhaps slightly better coverage across SE LA underneath a now fully modified moist airmass in place. Model soundings still reveal dry mid-level air in place yielding very little MLCAPE due to warm temperatures aloft, meaning most activity will remain mostly as shallow showers with not much vertical growth. By Monday, we begin to see a transition in the mid to upper-level pattern as ridging builds and strengthens over the southern Plains. The position of the mid-level height center and attendant surface high nearby or just to our northwest will support largely NE flow helping to drive drier continental air into the region (PW `1.0 to 1.2"). Given anomalously high heights and drier air, this will support above-normal temperatures with dry conditions persisting. No major changes against recent forecast trends with highs 5-8 degrees above normal through mid-week and no notable impacts expected. Sorry fake-fall, you were nice when you lasted but we`ll see you again soon! && .AVIATION... (00Z TAFS) Issued at 627 PM CDT Fri Sep 16 2022 VFR conditions will continue to prevail at all of the terminals through the entire forecast period as a drier and more stable airmass remains in place across the region. && .AVIATION... (18Z TAFS) Issued at 1156 AM CDT Fri Sep 16 2022 Expect VFR conditions for all area terminals through the forecast period. Only mentions in TAFs were sfc winds reaching 06-10kts this afternoon from mixing with a developing spotty Cu field around 3000ft AGL. Winds and Cu will dissipate around sunset this evening revealing primarily SKC and calm winds through mid- morning Saturday. KLG && .MARINE... Issued at 148 PM CDT Fri Sep 16 2022 A remnant frontal boundary will continue to support ongoing scattered showers and storms across marine areas late this week into the upcoming weekend. A few storms may be locally strong with gusty winds the main threat. Otherwise, winds will remain slightly elevated across outer marine zones around the mouth of the MS river out of the east around 15-20 knots going into late this evening. Small Craft Exercise Caution remains in effect for these areas. Otherwise, conditions become more calm and dry next week as high pressure builds into the region. && .PRELIMINARY POINT TEMPS/POPS... MCB 64 89 68 90 / 0 10 0 10 BTR 68 91 71 92 / 0 20 0 20 ASD 67 90 70 91 / 0 30 10 30 MSY 73 90 76 90 / 0 30 10 40 GPT 69 90 72 90 / 10 30 10 30 PQL 68 90 70 91 / 10 30 10 30 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM... AVIATION...PG
Area Forecast Discussion
National Weather Service Marquette MI
733 PM EDT Fri Sep 16 2022 .SHORT TERM...(Into early evening) Issued at 252 PM EDT FRI SEP 16 2022 The warm front attached to a low pressure system centered over nw MN remains situated across Lake Superior and the Keweenaw this afternoon. Water vapor imagery and the RAP analysis show weak shortwaves upstream over the Upper MS Valley and Central Plains which are poised to lift ne along with frontal boundary later this afternoon and tonight bringing additional chances for showers to the area. Radar imagery shows that showers have already moved into western Upper Mi early this afternoon and will continue to spread into central and eastern Upper Mi later this afternoon and evening. Another upstream shortwave over the Central Plains will bring another round of showers into Upper Mi late this evening and overnight. MUCAPE of 100-200 j/kg looks pretty minimal for t-storms but could maybe support an isolated storm. Highs under partly to mostly cloudy skies today have reached into the 70s most areas, except where persistent fog and low stratus have limited heating along Lake Superior in a e-ne flow, mainly over the Keweenaw, the nw shoreline of Marquette county and northern Baraga County. These areas have mostly stayed in the cooler 60s. Patchy dense fog over the Keweenaw could lift some in the next few hours as showers moving over the area stir up the low-levels. .LONG TERM...(Saturday night through Friday) Issued at 316 PM EDT FRI SEP 16 2022 Upper air pattern will consist of a broad 500 mb trough across the western U.S. with a shortwave ridge over the lower Great Lakes and sern U.S. 00z Sat. Numerous shortwaves are embedded in this trough and will pass through the area giving bouts of pcpn and some small breaks in pcpn in this forecast as well. In the extended, the GFS and ECMWF show a 500 mb closed low off the CA coast embedded in a western U.S. trough 12z Tue with a ridge across the central U.S. and a trough in New England. The trough in the western U.S. splits into two 12z Wed with the northern branch heading towards the northern plains. This northern branch quickly moves a shortwave through the upper Great Lakes Wed night. Differences then show up 12z Fri with some troughing in the Rockies and a shortwave ridge over the central U.S. Temperatures stay above normal through Wednesday before falling to below normal Thursday onward. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 733 PM EDT FRI SEP 16 2022 Less than ideal conditions are anticipated for aviation interests, particularly at KCMX. Low cigs and/or low visbys are looking to continue well into the overnight hours as a stalled frontal boundary remains draped across Upper Michigan. SHRAs will be persistent, although there could be some brief breaks during the middle of the day tomorrow. Srly to SWrly winds should prevail at KIWD and KSAW, with a bit more of a variation at KCMX into early tonight with the nearby boundary. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 316 PM EDT FRI SEP 16 2022 The wind looks to stay below 25 knots through the forecast period. Where rain has occurred, could see some marine fog to continue over Lake Superior. Pressure pattern not real strong, so no gales expected. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Voss LONG TERM...07 AVIATION...lg MARINE...07
Area Forecast Discussion
National Weather Service New York NY
1104 PM EDT Fri Sep 16 2022 .SYNOPSIS... High pressure builds slowly southward from eastern Canada through Saturday, moving offshore late Saturday into Saturday night. The high remains south of the region Sunday. After fair weather on Sunday, a frontal system will impact the region for the beginning of next week. A quick round of heat for the middle of the week will then be followed by a strong cold frontal passage by the end of the week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Forecast on track. Updated cloud cover to account for broken stratocu making it down to the western half of the area overnight into Sat AM per RAP fcst soundings, also some high clouds rounding the periphery of an upper ridge to the west. Surface high pressure builds toward the region tonight. Winds will be rather light, becoming N and NE. With a similar air mass to last night over the region for tonight, and near ideal radiation cooling expected, went under the guidance for lows at the normally cooler locations. Otherwise, leaned toward the slightly cooler MOS guidance for lows. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... Weak upper riding remains across the northeast and mid Atlantic Saturday into Saturday night, while the surface high builds over the region Saturday, and offshore late in the day through Saturday night. An easterly flow through most of the day Saturday will keep temperatures in the lower to mid 70s, and again leaned toward the cooler MOS guidance. A return flow setup up Saturday night with weak warm advection. And with the upper ridge weak high clouds continue to move over the region. Lows Saturday night will be higher than Friday night lows, and used the NBM guidance. && .LONG TERM /SUNDAY THROUGH FRIDAY/... High pres builds over the Atlc on Sun. H85 temps warm to around 15C, which will allow all areas to reach the 80s. NJ zones could approach 90 with the wly component llvl flow. Heights begin to fall Sun ngt into Mon as an upr low tracks across Ontario into Quebec. This should trigger shwrs and tstms invof a nearly stationary front over nrn New England into Upstate NY. The convection could cause the boundary to sag swd close to the cwa and produce some pcpn. Based on the latest modeling it is a low probability event however. The best chances for rain come with the main cold front on Mon and Mon ngt. Drying out and cooler on Tue behind the front. Cyclonic flow aloft and steep lapse rates could allow for isold-sct convection during the day, depending on how far south the main h5 low gets. Right now the nrn tier of counties is favored, although this may change over the coming days. A quick warmup on Wed as h85 temps soar to around 20C by Wed ngt into Thu. Timing will be critical as it looks like a cold front will be quick to sweep thru thereafter. If the peak of the thermal ridge sets up during the day, particularly Thu, highs mixing out into the mid and even upr 90s possible. NBM 95 percent reflects this, producing highs right at record lvls for the date, the first day of fall. Shwrs and tstms accompany the front Thu/Thu ngt, then significantly cooler on Fri with h85 temps dropping into the single digits. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... VFR as a back door cold front moves across, followed by high pressure building from the north. The high will then shift offshore on Saturday. Winds should be light/vrb or light NE overnight through mid morning Sat. Then as the high shifts offshore, expect winds to shift to a more easterly direction late Sat AM, then become SE-S at most sites Sat PM. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Timing of wind shifts daytime Sat should be close. .OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY... .Saturday night and Sunday...VFR. .Monday...Brief MVFR or lower cond possible with chance of afternoon/evening showers/tstms. .Tuesday...Mainly VFR. Only slight chance of a shower. .Wednesday...VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/ && .MARINE... Winds and seas will remain below SCA levels through Saturday night with high pressure building over the waters. SW winds could produce SCA conditions on the ocean Sun-Mon. Elsewhere, winds and seas look to remain blw sca lvls attm. All waters fall blw sca lvls on Tue behind a cold front, then sub sca cond are expected to continue on Wed. Increasing swell and swly flow may bring the ocean back to sca lvls on Thu. && .HYDROLOGY... No hydrologic impacts are expected through Friday. && .TIDES/COASTAL FLOODING... There is a low risk for the development of rip currents at the ocean beaches through Saturday, and a moderate risk for Sunday. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...12/MET NEAR TERM...BG/DS/MET SHORT TERM...MET LONG TERM...12 AVIATION...BG MARINE...12/MET HYDROLOGY...BG/MET TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service Raleigh NC
822 PM EDT Fri Sep 16 2022 .SYNOPSIS... High pressure will extend into central North Carolina into early next week. && .NEAR TERM /THROUGH TONIGHT/... As of 822 PM Friday... Current forecast on-track for the rest of the night with mainly clear skies and light winds. The only tweaks that will be needed this evening are dwpts for the next couple hours, as they are currently running several deg higher than forecast at 00Z. However dwpts are still forecast to drop over the next few hours and overnight as noted below, and especially since the latest obs show lower 50s dwpts just to our east that hrrr shows advecting wwd across our NE zones overnight. No major changes this evening. Prev near term AFD as of 150 PM... High pressure remains situated near Delmarva and into VA, with northeast flow persisting into central NC. It is another afternoon of fair weather cumulus as moisture in the low-level increased early this morning. These clouds will dissipate around sunset, leaving mostly clear skies overnight. The latest GOES satellite indicate the vertically integrated smoke has reached central VA, Delmarva and is off the coast of of NJ. This plume is forecast to reach the northeast Piedmont and northern Coastal Plain by early Sat. Dewpoints have not dropped as much as expected but still are very comfortable in the upper 50s in the west to lower 60s in the east. A 1026 mb high over eastern Canada will settle into the NE US early Sat. This will allow drier air to work in, especially across the Coastal Plain, with dewpoints dropping into the low/mid 50s there. As such, radiational cooling will be maximized in this region with temperatures in the low to middle 50s. Elsewhere, lows will dip into the upper 50s to around 60. Cannot rule out another night of some shallow fog, with the best chance along the Coastal Plain and eastern Piedmont near bodies of water. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... As of 150 PM Friday... The vertically integrated smoke over northeast NC Sat will rotate to clockwise to the west during the day/evening, with the greatest concentration over the eastern Piedmont and Coastal Plain. This will be driven by the surface high over the NE that will track southeast off of Delmarva by early Sun. The result of this smoke may be some slight haze. A pretty sunset Sat night is possible with some partial high cloudiness with a disturbance moving into the Ohio Valley. Low- level thicknesses are little changed from Fri so low to middle 80s are again expected under sunny skies. Clear skies and light winds will favor another night of good radiational cooling. Moisture will increase again at low-levels across the Sandhills and Coastal Plain overnight with return flow south of the high pressure system. That could favor fog development in the east. Overnight lows to be in the upper 50s to low 60s. && .LONG TERM /SUNDAY THROUGH FRIDAY/... As of 201 PM Friday... Dry weather with a warming trend will define the beginning of the long term period... with a trough offshore and high pressure extending across our area from the east. Highs Sunday and Monday will be in the mid-upr 80s, which is about 5 or so deg above normal. On Tuesday a shortwave trough will pass by to our north. Given the limited opportunity for deep pre-trough flow and moisture advection, for now will continue to keep the passage of that system dry for Tuesday and Wednesday with temps remaining well above normal. High pressure and dry weather will briefly build back in for Thursday, but yet another s/w trough passing by to our north Thursday night and Friday will push a front through our area Thursday night. GFS suggests a few showers with that fropa while ECMWF keeps us dry with diminishing pwats as the front crosses the mountains. Otherwise, will have a wait more models runs to see to what extent this trough and frontal system has on Fiona. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... As of 727 PM Friday... Through 00Z Sunday: VFR conditions expected under mainly clear skies and winds less than 10 kt...NE tonight, become ESE Saturday afternoon. Outlook: VFR is largely forecast Sat through Wed, though there remains a continued chance of sub-VFR fog Sun and Mon mornings with returning low-level moisture, primarily at FAY/RWI and possibly RDU. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Kren NEAR SHORT TERM...Kren LONG
Area Forecast Discussion...CORRECTED
National Weather Service Reno NV
253 PM PDT Fri Sep 16 2022 .SYNOPSIS... Oppressive smoke and degraded air quality, courtesy of the Mosquito Fire, will persist through the end of the week. But changes are on the way. An early season storm will bring much cooler conditions along with chances for rain and high elevation snow Sunday through Wednesday. Winds will increase ahead of this system Saturday and Sunday. Pleasant fall conditions return by the following weekend. && .DISCUSSION... An early season low pressure system is still on track to drop south offshore the western US Saturday and slowly rotate southeast off the northern and central CA coast before pushing inland early next week. Although current model guidance shows some uncertainty with timing and position, ensemble clusters still show a cooler, wetter trend with the system tapping into additional Pacific moisture as it briefly stalls offshore northern-central CA overnight Saturday into Sunday before lifting northeast into CA- NV overnight Tuesday into Wednesday. Here are the updated highlights: * Winds: Saturday and Sunday will remain rather breezy at the surface over the Sierra and western NV as the increasing southwest upper flow continues to keep pace with the entrance of a 105-115 kt jet streak core over west-central US. ECS/GFS ensemble meteogram simulations continue to project breezes gusting 25-40 mph over some lower valley areas of western NV with ridge-top winds around the Lake Tahoe Basin briefly topping 70+ mph range Sunday into Monday morning. Although these increased winds herald a welcome change to cooler conditions, wind impacts include potential for smoke impacts from the Mosquito fire, choppy lake conditions, and increased turbulent air for aviation interests. A lake wind advisory is in effect to address the recreation concerns on Saturday for Lake Tahoe and Pyramid Lake. * Precipitation: More recent ensemble model simulations continue to trend increased QPF values with the most notable increases centered over windward areas of the Sierra crest with increased spillover into western NV overnight Monday into Tuesday morning. - At least 70-80% chance of a half inch or more across most higher elevation locations along the central and northern Sierra crest through early next week. Some higher terrain favored areas along the central Sierra with better forcing and orographic lift have at least a 50% chance for better than an inch of rainfall overnight Sunday through Monday morning. - Blended guidance show at least a 40-50% chance of a few hundredths of an inch making its way east into the Basin and Range of western NV with one in four chance for as much as a quarter inch of measurable precipitation for some lower elevation areas of Churchill and Pershing counties. - Snow levels will drop overnight Saturday into Sunday to 7000- 7500’ across northeast CA before settling into a 8500’-9000’ range through mid-week. Therefore, the potential for higher elevation snow is still on track with the chance for a couple of inches of white stuff adorning some higher peaks across the Sierra Crest early Sunday morning through Wednesday. * Temperatures: A fairly decent signal for a significant shift to colder temperatures. Daytime highs will be as much as 10-20 degrees below seasonal normal Sunday into the middle of next week with the colder spots in the Sierra are still dropping into the more fall-like 20s overnight next week. Lower elevation gardeners like myself should be safe with overnight lows only bottoming out in the 40s through the forecast period. Time to pull out that cold weather gear from storage because sweater time weather will be upon us sooner than later. -Amanda && .AVIATION... * Smoke plume from the Mosquito fire continues to pump widespread areas of smoke into the the Sierra and far western NV with concurrent haze and reductions in slant range visibility for most other areas across the western NV. Smoke which had settled into those lower valley areas with main terminals (KRNO-KCXP- KMEV) during previous overnight period under very stable conditions will see a brief period of VFR-MVFR through the afternoon with the exception of KTRK which will get no better than IFR with VIS ranging 1-3SM. * With the onset of afternoon breezes, local winds will transport thicker smoke layers east and southeast into the Truckee area (KTRK) and Lake Tahoe basin, as well as far western NV terminals along I-580/US-395 where smoke layers will once again bring periods of IFR CIGS/VIS through tonight. Some smoke and haze may still filter slowly south along the eastern Sierra to KMMH later this evening as local breezes diminish and lower valley stabilize during the early morning hours Saturday. * Current model guidance shows a shift in the prevailing upper flow to a more S-N direction overnight into Saturday morning with FL100- 180 winds increasing from the S-SW at 35-45 kts. HRRR near surface smoke simulations indicate a concurrent shift north of the thicker smoke plumes along the northern Sierra Crest that will signal a return to mostly VFR conditions for main terminal locations through Saturday. With the close proximity to the Mosquito fire, KTRK will be the exception with a return to IFR-MVFR CIGS/VIS as low level winds diminish and decouple overnight with an increased chance for lingering smoke layers going into Saturday evening. But timing still remains an issue dependent upon on local winds and fire activity. * An upper low still projected to influence the west coast later Saturday through early next week will bring increase precipitation chances that could bring reduced fire activity, enhanced winds Saturday-Sunday with gusts approaching 25-30 kts for Sierra and western NV terminals that includes localize turbulent low and mid level air, and mountain obscuration as ceilings lower with the approaching low pressure system. -Amanda && .FIRE WEATHER... Gusty winds along with dry conditions will materialize ahead of an incoming system for the weekend with localized critical fire conditions. Big changes are in store for the weekend as the system pushes into Northern CA and NV. Plan on wetting rains for much of the Sierra and western Nevada as well as some high elevation snow for areas above 8500 feet. Wind Potential: Wind trend about the same for Saturday and Sunday with wind gusts around 30-35 mph for much of the region with a 40% chance of winds along the eastern Sierra Front approaching 40 mph. Wind gusts along the Sierra ridges may be 70+ mph as the upper level jet with the system pushes into the region. The significant dry fuels across the region have us keeping an eye on these more windy conditions, but thankfully the humidity levels will slowly be increasing through the weekend. Wetting Rain/Snow Potential: This will not be a season ending event for the region, but it may help to slow the fire season. Widespread wetting rain and high elevation snow will push into northeast CA and the Sierra late Saturday into Sunday with periods of rain and high Sierra snow through Wednesday. Best chances for spillover and wetting rains across western Nevada will arrive early next week and continue through midweek as the system slowly exits the region. -Edan && .REV Watches/Warnings/Advisories... NV...Lake Wind Advisory from 2 PM to 11 PM PDT Saturday NVZ002. Lake Wind Advisory from 2 PM to 8 PM PDT Saturday NVZ004. CA...Lake Wind Advisory from 2 PM to 11 PM PDT Saturday CAZ072. && $$
Area Forecast Discussion
National Weather Service Topeka KS
602 PM CDT Fri Sep 16 2022 ...AVIATION UPDATE... .DISCUSSION... Issued at 248 PM CDT Fri Sep 16 2022 Key Points: - More chances of showers and storms overnight through Saturday - Hot Sunday through Wednesday with near record temperatures possible The subtle shortwave that has brought light showers to parts of the area this morning can be seen departing to the east via mid-level water vapor imagery. Lingering showers south of I-35 should clear out in the next hour or so with clouds scattering out into the evening. Another subtle wave within the southwest flow over the Rockies is progged to develop scattered thunderstorms initially in northern CO and western NE this evening, with a LLJ aiding in low- level lift further south into KS late tonight. As such, most showers and storms look focused along the KS/NE border with higher PoPs north of I-70 overnight into Saturday morning as storms move east. The majority, if not all, of this first round should be out of the area by 18Z. While that round of activity is ongoing, a surface low is progged to develop in western KS in response to the mid-level perturbation. By late afternoon to early evening, a boundary from that surface trough looks to be the focal point for redeveloping storms. Members of the 12Z HREF are hinting at convergence along the boundary with initiation around 00-01Z, generally along a line from Marysville to Abilene. However, forecast soundings in this area are weakly capped by 21-22Z, so would not rule out development in the late afternoon. This round of storms could produce a few strong to severe storms with MLCAPE of 2000-3000 J/kg, effective bulk shear of 25-30 kt, and forecast soundings showing an inverted-V profile. This would point to a damaging wind threat, though some large hail may be possible as well. There are varying ideas among guidance on how well any activity holds together as it moves east in the evening and overnight, but instability decreases and there is a trend for less lingering activity by Sunday morning. Sunday through Wednesday, upper-level ridging is expected to strengthen and bring a dome of anomalously warm air over the region. Ensemble data shows little spread in temperature guidance and indicates high confidence for hot weather during the first part of next week. Unfortunately, the WAA will bring higher dew points further north as well. Highs in the 90s look likely with heat indices in the low 100s not out of the question, and lows in the 70s provide little opportunity for relief overnight. Record highs and even record warm lows may be in jeopardy during this time period, so we`re not done with summer heat just yet. A cold front does look to bring relief by mid to late week, but there are timing variations between the GFS and ECMWF, which results in low-end PoPs during much of Wednesday and Thursday and a wide range in possible temperatures on Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Sunday) Issued at 602 PM CDT Fri Sep 16 2022 VFR conditions are forecast to continue into Saturday. A good low level jet and isentropic assent could lead to some elevated showers and storms by daybreak Saturday mainly across northern KS. Ensembles show KMHK has the higher probability for precip, but KMHK remains on the southern flank of the most likely area of precip. With the better theta-e advection shifting into SE NEB and SW IA, think a VCTS is the better way to go at this time. Will keep a mention of LLWS in the forecast since RAP and NAM forecast soundings show a 40KT jet forming above the nocturnal inversion. && .CLIMATE... Issued at 248 PM CDT Fri Sep 16 2022 Record temps for Topeka ------------------------ Sep 18 warmest low: 76 (1893) Sep 18 high: 101 (1925) Sep 19 warmest low: 77 (1931) Sep 19 high: 97 (1954) Sep 20 warmest low: 75 (1895) Sep 20 high: 98 (1980) Sep 21 warmest low: 76 (1893) Sep 21 high: 98 (1956) Record temps for Concordia --------------------------- Sep 18 warmest low: 76 (1947) Sep 18 high: 100 (1931) Sep 19 warmest low: 79 (1931) Sep 19 high: 98 (1931) Sep 20 warmest low: 74 (1895) Sep 20 high: 96 (1893) Sep 21 warmest low: 75 (1956) Sep 21 high: 103 (2005) && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...Picha AVIATION...Wolters CLIMATE...Picha