Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/10/20

Area Forecast Discussion
National Weather Service Houston/Galveston TX
918 PM CST Thu Jan 9 2020 .DISCUSSION... The evening update has already been sent and will be awaiting the 00z model suite. Primary change was to lower POPs during the daytime hours on Friday across the SE 2/3 of the area and pared back timing of the mention of possible severe until the late afternoon hours. Most model fcst soundings show a warm nose around 700mb persisting for much of the day. And with lack of a focusing mechanism etc, wouldn`t expect much more than iso/sct shra. Probably could have gone even lower, but didn`t want to make drastic changes between forecast packages. Will let the midnight shift re-evaluate coverage & any potential for iso severe cells during the day Fri as they get a look at the full picture. Expect a line of tstms to develop to our west and move across southeast Texas in the 7pm-3am timeframe. Texas Tech WRF & the 00z HRRR show a slightly faster movement...generally clearing the area and to the east by midnight-2am. Still have a concern whether the cap around 700mb erodes across the far southern part of the area, but should definitely weaken with the approach of the upper trof. But regardless, even forward momentum of the precipitation itself could aid in some of 50-65kt just above the surface mixing down to produce some damaging winds. Otherwise, helicity/shear parameters still look quite impressive and the other hazards (wind/tornado/hail) that have been well advertised remain in play Fri night. 47 && .PREV DISCUSSION... /ISSUED 633 PM CST Thu Jan 9 2020/ AVIATION [00Z TAF Issuance]... Even with breezy conditions persisting tonight, BKN/OVC MVFR cloud decks will likely prevail across much of SE TX. The patchy showers should be moving out to the north, but given the strong WAA, would not be too surprised if -DZ/-RA showed up in the obs overnight. At the coast, sea fog should persist...with visibilities not expected to crater completely given the strong onshore winds. As for tomor- row, models have been trending with the idea that most of the POPs will be with the front/trof axis itself. One of the big issues may be the wind shear pattern setting up tomorrow afternoon/evening as the low-level jet strengthens further. The mention of TS/VCTS will likely be needed for most sites with the 06Z TAF package. 41 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 67 76 45 54 35 / 40 60 100 10 0 Houston (IAH) 68 76 54 60 38 / 20 40 90 10 10 Galveston (GLS) 66 72 57 63 48 / 10 30 90 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...High Rip Current Risk through Friday evening for the following zones: Brazoria Islands...Galveston Island and Bolivar Peninsula...Matagorda Islands. GM...SMALL CRAFT SHOULD EXERCISE CAUTION from 6 AM CST Friday through Friday evening for the following zones: Galveston Bay... Matagorda Bay. Small Craft Advisory from 9 AM Friday to midnight CST Friday night for the following zones: Coastal waters from Freeport to Matagorda Ship Channel TX out 20 NM...Coastal waters from High Island to Freeport TX out 20 NM. SMALL CRAFT SHOULD EXERCISE CAUTION through Friday morning for the following zones: Coastal waters from Freeport to Matagorda Ship Channel TX out 20 NM...Coastal waters from High Island to Freeport TX out 20 NM. Small Craft Advisory until 9 AM CST Friday for the following zones: Waters from Freeport to Matagorda Ship Channel TX from 20 to 60 NM...Waters from High Island to Freeport TX from 20 to 60 NM. Gale Warning from 9 AM Friday to midnight CST Friday night for the following zones: Waters from Freeport to Matagorda Ship Channel TX from 20 to 60 NM...Waters from High Island to Freeport TX from 20 to 60 NM. && $$
Area Forecast Discussion
National Weather Service Wichita KS
540 PM CST Thu Jan 9 2020 .SHORT TERM...(This evening through Sunday night) Issued at 229 PM CST Thu Jan 9 2020 Forecast highlights: *Severe weather and heavy rain threat Friday southeast Kansas. *Wintry precipitation Friday afternoon-evening central Kansas. *Wintry precipitation and possible heavier snow eastern/southeast Kansas late Friday night-Saturday. Continued moisture advection from the south tonight will allow for low clouds to expand across much of southeast Kansas overnight. Low- level lift coupled with the deepening saturation should support patchy drizzle. Large-scale ascent will increase dramatically across the region from the southwest Friday, as potent shortwave energy ejects east onto the southern/central plains, interacting with a sharpening/deepening stalled frontal zone across the region. Increasing moisture, instability and lift should support a round of numerous showers/thunderstorms spreading northeast across the region by late morning Friday. This scenario is supported by the hi-res model suite. This convective activity is expected to spread north/northwest into portions of central KS where the colder air resides, supporting the potential for convective sleet/snow for a time Friday afternoon and evening. If especially the NAM/RAP/HRRR solutions verify, a winter weather advisory may be needed for snow/sleet accumulations of 1-3 inches across central KS along with strong north winds. Evening/night shift will need to monitor trends. Next focus is severe potential southeast Kansas Friday afternoon. The RAP and NAM especially develop/sustain a fairly healthy warm sector south of the stationary front, with unseasonably rich boundary layer dewpoints coupled with modest mid-level lapse rates producing 500-1000 J/kg MUCAPE. While a messy storm mode will likely ensue by midday given veer/back vertical wind profile, strong lift, and boundary mostly parallel to mid/upper flow, strength of deep layer shear coupled with marginal instability could support a few strong to severe storms over southeast KS. Main threats will likely be QLCS damaging wind gusts and to a lesser extent marginally severe hail. Of note...given the strong low and deep layer shear vectors and low LCLs, cannot completely rule out a tornado, especially if impressive RAP/NAM progged low-level CAPE values verify. Stay tuned. -ADK Fri night into Sat...Any destabilization across southeast KS will be on the wane rather quickly by the early evening hours on Friday as the cold front ushers in much colder air during the early evening hours. Any lingering precipitation in the wake of the front will transition to a wintry mix and then snow as the cold air rapidly deepens in the wake of the front but we should see a lull in the activity during the evening hours Friday night. Large-scale forcing for ascent will be on the increase after 07-10Z on Sat and into Sat morning as the mid/upper trough emerges from the Rockies. A transient period of coupled forcing will be most likely during the morning hours on Sat, especially along and east of the Kansas Turnpike where the higher snow accumulations of 4-6 inches (locally higher) are anticipated. There could be a 4-6 hour duration of enhanced lift within the TROWAL airstream on Saturday morning where higher snowfall rates are anticipated. Due to the combination of wind/snow and light wintry mixed precipitation a winter storm watch will be issued for a chunk of south central KS and all of southeast KS. Highs on Sat will hover in the upper 20s for most locations. Large-scale forcing for subsidence will rapidly overspread the region in the wake of the trough late Sat afternoon/early Sat evening as shortwave ridging returns to the central CONUS. Another progressive shortwave trough will sweep across the area on Sunday with limited impacts on sensible weather. Below normal temperatures area anticipated across the area on Sun with highs struggling to climb out of the 30s. A heavy snowpack will likely result in even lower temperatures. -MWM .LONG TERM...(Monday through Thursday) Issued at 229 PM CST Thu Jan 9 2020 A progressive mid/upper flow regime is anticipated through the period resulting in dry weather conditions and seasonable temperatures early in the week. Another blast of Canadian air is progged to arrive on Wednesday driving temperatures well below normal once again. Highs toward the end of the period may struggle to climb out of the 20s although dry weather is expected to prevail through the period. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 524 PM CST Thu Jan 9 2020 The wind and LLWS conditions have moved off to the east. Clouds are starting to encroach on the region. VFR conditions currently rules the region but MVFR ceilings are expected to slowly move into the region and affect all terminals. IFR ceilings will also eventually replace the MVFR toward morning tomorrow. During the day tomorrow, rain and some thunderstorm possibilities will be become prevalent. The thunderstorm threat will primarily affect the CNU terminal but ICT and HUT have a chance for an isolated thunderstorm. Much colder air will be pushing into the region during the day Friday. This will cause the rain to change over to sleet and snow toward the end of the TAF period. For this TAF period, this will primarily affect the RSL, GBD and SLN terminals. HUT and ICT may see some mix wintry precipitation toward the end of the TAF period. Metzger && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 43 45 16 28 / 10 90 60 90 Hutchinson 36 37 13 29 / 10 90 50 50 Newton 39 39 14 26 / 10 90 60 90 ElDorado 45 47 16 26 / 20 90 70 100 Winfield-KWLD 51 55 17 28 / 20 90 70 100 Russell 30 30 9 29 / 0 80 40 10 Great Bend 31 31 9 30 / 0 80 40 10 Salina 33 33 12 28 / 0 80 50 40 McPherson 35 35 11 27 / 10 80 50 50 Coffeyville 56 62 20 29 / 50 100 90 100 Chanute 53 56 19 26 / 50 100 90 100 Iola 51 54 19 26 / 50 100 90 100 Parsons-KPPF 54 60 20 28 / 50 100 90 100 && .ICT WATCHES/WARNINGS/ADVISORIES... Winter Storm Watch from Friday evening through Saturday afternoon for KSZ052-053-068>072-083-091>096-098>100. && $$ SHORT TERM...ADK-MWM LONG TERM...MWM AVIATION...ELM
Area Forecast Discussion
National Weather Service Lincoln IL
703 PM CST Thu Jan 9 2020 .SYNOPSIS... Issued at 703 PM CST Thu Jan 9 2020 A slow-moving storm system will bring heavy rain to central Illinois over the next 48 hours...with many locations picking up 3 to 4 inches of rain. As colder air gradually filters into the region, freezing rain and snow will develop west of the I-55 corridor...particularly on Saturday. Snow accumulations of 3 to 7 inches will be possible west of the Illinois River by Saturday night. && .UPDATE... Issued at 703 PM CST Thu Jan 9 2020 01z/7pm surface analysis shows a slow-moving cold front extending from eastern Iowa southwestward to Oklahoma. Widespread showers and a few thunderstorms have developed in advance of the front from southwest Illinois into the Ozarks. Based on radar trends and the last few runs of the HRRR, it appears these showers will primarily impact locations east of I-55 tonight. Further northwest, the HRRR and 18z NAM both hint at widely scattered showers developing immediately along the front as it pushes into the Illinois River Valley after midnight. Given clear trends, have delayed and significantly lowered PoPs across the N/NW KILX CWA. Think the Peoria area will remain dry until after midnight, then only scattered light showers will occur. The steadiest/heaviest rain with a few embedded thunderstorms will set up along/southeast of a Champaign to Taylorville line where categorical PoPs are warranted. && .SHORT TERM...(This evening through Friday) ISSUED AT 340 PM CST Thu Jan 9 2020 Will continue the wind advisory for the rest of this afternoon til 6 pm for areas along and north of I-72, as south winds of 20-32 mph still gusting 35 to 45 mph. Winds will gradually diminish after sunset and may be able to cancel the wind advisory a little early. Strong south winds brought mild low to mid 50s over the CWA, with 3 pm temps ranging from 47 in Champaign to 58 in Macomb. A broken band of mainly light rain showers lingered over areas along and east of a Champaign to Litchfield line, though more widely scattered se of I-70. Cloudy skies prevailed over central/se IL with ceilings gradually lowering during the day, still in VFR category, though approaching MVFR in sw CWA. Mid afternoon surface map shows 1004 mb low pressure over west central WI with its cold front thru central IA into nw MO and se KS. Strong warm air advection over IL along with some increasing moisture. A tongue of moisture had worked its way into sw and eastern IL with precipitable water values of 0.75 to 1 inch east of I-55 this afternoon with a strong 50-60 kt sw 850 mb jet. Latest CAMs continue to show increasing rain showers over central and se IL during tonight, especially se of the IL river where precipitable water values reach 1-1.25 inches by late tonight. Rain chances look less nw of the IL tonight and Fri morning especially far nw CWA. Continued isolated thunderstorms late evening and overnight from I-72 south. Milder lows tonight in the upper 40s to around 50F, except cooler lower 40s over Knox and Stark counties where a cold front moves into late tonight. Low pressure deepening over the Red River valley along the eastern TX/OK border by late Fri afternoon while the cold front slowly moves se across the IL river valley and approaches I-55 Friday afternoon. Expect rain showers and isolated thunderstorms to ramp up again during Friday afternoon and Fri evening from sw to ne along with moderate to heavy rains arriving. Highs Fri to contrast form the mid to upper 40s nw of the IL river, to the upper 50s and lower 60s over central and se CWA. Surface low pressure deepens as it tracks into ne AR by dawn Sat and into NW Indiana by 6 pm Sat. Widespread moderate to heavy rains Friday night and Sat morning especially east of the IL river with 3-4 inches expected and locally higher amounts with thunderstorms. Heavy rainfall is aided by strong lift with favorable position of upper level jet. Continued Flood Watch for all but far nw 3 counties from Fri afternoon thru noon Sat, except thru 3 pm Sat in eastern IL. The rain is expected to mix with and change to freezing rain and sleet nw of the IL river during overnight Fri night especially late and continue Sat morning. The freezing rain and sleet to mix with and then change to snow over Knox and Stark counties Sat morning, and then over rest of IL river valley late Sat afternoon. Highs Sat contrast from near freezing over Knox and Stark counties, to the upper 50s to mid 60s in southeast IL. Much colder air arriving during Sat evening across rest of central IL changes rain to snow with deformation zone over area Sat evening and expect best snow accumulations late Sat afternoon and Sat evening from I-55 nw. Between 3-7 inches of snow possible nw of the IL river with a tenth to quarter inch of ice too, highest over Knox and Stark counties. Issued a winter storm watch for areas nw of the IL river from midnight Fri night thru midnight Sat night. Some blowing and drifting snow could develop too during Sat evening over nw CWA as winds stay strong and temperatures drop below freezing. Much of light snow diminishes ne of CWA overnight Sat night, with lows Sat night in the mid teens nw of the IL river to upper 20s to near 30F in southeast IL. Dry and seasonably cool weather arrives on Sunday with lighter winds as high pressure settles in by Sunday night. Lows Sunday night range from lower 20s nw of IL river to the lower 30s in southeast IL. A northern stream system could bring a few light snow showers or flurries to areas nw of the IL river Sunday night mainly in the evening hours. Otherwise dry Monday and Mon evening across the area with temps modifying. Highs Sunday in the lower 30s northern/nw CWA and lower 40s in southeast IL. Highs Mon range from upper 30s over northern CWA to 45-50F in southeast IL. Still some differences with models with wx systems during mid week and stayed close to model consensus. This shows small pops overnight Mon night and Tue morning and again Wed and Wed night. Milder Tue with highs in the 40s in central IL and low to mid 50s in southeast IL. Colder air starts moving into central IL on Wed and across the area Wed night and Thu as we return to more winter like temperatures as stronger Canadian high pressure settles into the Midwest late Wed night and Thu. .LONG TERM...(Friday night through Thursday) ISSUED AT 340 PM CST Thu Jan 9 2020 && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 538 PM CST Thu Jan 9 2020 Strong S/SW winds gusting 20-30kt will persist for the next couple of hours before gradually diminishing by mid to late evening. As a frontal boundary pushes into the Illinois River Valley, winds will become light/variable at KPIA toward dawn Friday...while winds decrease to 12kt or less further east at the remaining terminals. Ceilings will steadily lower this evening, with MVFR conditions expected across the board after 02z. Current radar imagery shows numerous showers well upstream across the southern half of Missouri. These showers will track northeastward and primarily impact locations east of the Illinois River from late evening through Friday morning. After that, a lull in precip appears likely before the next wave of heavier rain arrives by Friday evening. && .ILX WATCHES/WARNINGS/ADVISORIES... Flood Watch from Friday afternoon through Saturday afternoon for ILZ045-046-055>057-062-063-066>068-071>073. Flood Watch from Friday afternoon through Saturday morning for ILZ029-031-036>038-040>044-047>054-061. Winter Storm Watch from late Friday night through Saturday evening for ILZ027>030-036-040. && $$ UPDATE...Barnes SYNOPSIS...Barnes SHORT TERM...07 LONG TERM...07 AVIATION...Barnes
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
916 PM EST Thu Jan 9 2020 .SYNOPSIS... High pressure to the north will slide offshore later tonight and Friday. An unsettled pattern is then likely for this weekend and into early next week as a cold front approaches and lingers near or over the area. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... As of 910 PM Thu...High res mdls show the coastal trof pushing onshore over much of the coast after midnight. Only change was to increase temps a bit after 06z central and srn cst as temps jump with SSE flow. Prev disc...Some shallow moisture will creep toward the coast tonight as an inverted trough sets up just off the coast. The latest HRRR and 3km NAM continues to indicate light rain showers or sprinkles approaching the coast overnight, but left dry for all but OBX zones as continued quite dry in the bndry layer. Low temperatures fairly mild with increasing cirrus shield invading from the west, and combined with slowly rising TD`s overnight, expecting mid/upr 30s interior with 40s coast. Temps near coast will likely experience lows pre midnight, with steady or slowly rising trend towards daybreak. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... As of 330 PM Thu...Big warming trend commences on Fri as High pres migrates offshore and Mid Atlantic ridge begins to build towards the SE CONUS, while shortwave trough deepens across the Plains states. Low level flow will veer srly and ocnl sct/bkn strato cu will be present. Despite the clouds, it will be well above climo with highs 65-70 most locales. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... As of 3 AM Thurs...High pressure will be offshore Friday and into Saturday. Unsettled weather is expected Sat night through early to mid next week as a cold front approaches then stalls nearby or across the area. Near record to record highs are expected this weekend. Saturday...Eastern NC will be between two systems; to the east, high pressure extending into the region, and to the west, a low pressure system will take shape over the OH Valley with a cold front extending southward into the Deep South. Expect an increase in southerly flow over the area providing strong WAA. Highs will climb well into the 70s inland, near 70 beaches, approaching or exceeding records, depending on cloud cover. See CLIMATE section for more information. Should see most rainfall hold off until Sat night, though not expecting a lot of rain as most of the energy gets shunted north and west of E NC, and amounts less than a quarter inch or so. Continued the mention of slight chc thunder overnight as TD`s max out in the 60s, so overnight lows extremely warm into the 60s. Sunday into Wednesday...The low pressure system will lift into the Great Lakes region/Central Canada, while the associated cold front will move into the area on Sunday, shall nearby or across the area, before pushing through Wednesday (maybe). The latest models are having timing difference in when the front will push through. Overall, the front is then expected to be more or less orientated east/west across the area Monday into mid week, with continued rain chances. Maintained the likely pops on Monday and Tuesday, with a 30-40% Wednesday, as there is enough consensus between the forecast models and their respective ensembles that this period will be quite unsettled. Temperatures will continue to be well above average, at least +20 degrees F, for this period, with highs generally around 70 and lows in the 50s to near 60, depending on cloud cover and rain coverage. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... Short Term /through 18Z Friday/... As of 610 PM Thursday...High pres to the N will grad slide offshore with a weak coastal trof moving onshore tonight. Expect VFR to cont to dominate with mainly some high clouds. As the low lvl flow turns SE in wake of coastal trof could see some patchy lower SCU develop but confidence in cvrg is low so just kept sct in tafs. As moisture conts to increase Fri some bkn SCU cigs poss but think will be mainly in VFR range. Long Term /Friday night through Monday/... As of 315 AM Wed...VFR conditions prevail through Saturday afternoon as a cold front approaches the area and eventually stall over the area, leading to periods of sub-VFR conditions late weekend through early next week. && .MARINE... Short Term /Today and Tonight/... As of 910 PM Thu...Strongest winds now over far srn outer wtrs and shld grad weaken as coastal front pushes toward the coast overnight. Prev disc....N/NE winds are currently 15 knots. Seas are generally 3-5 feet. As high pressure builds south and east from the Great Lakes to the mid Atlantic tonight, winds will shift to E and diminish to 5 to 15 kts. Seas will drop from 3-5 feet to 2-4 feet on all waters by tonight and remain through Fri. Winds veer srly though remain light Fri. Long Term /Friday night through Monday/... As of 315 AM Thurs...High pressure will extend over the coastal waters from the western Atlantic with winds becoming southerly, and increasing to 15-20 kts by Friday night ahead of an approaching front. Winds gradient will tighter further more Saturday night peaking S to SW 25-30 kts through early Sun morning, with seas building to 8-12 ft. SCA and Gale headlines will likely be needed this weekend, with SCA seas lingering into early next week. && .CLIMATE... Record High temps for 01/11 (Saturday) LOCATION TEMP/YEAR New Bern 77/1974 (KEWN ASOS) Cape Hatteras 70/2014 (KHSE ASOS) Greenville 78/1930 (COOP - Not KPGV AWOS) Morehead City 69/2017 (COOP - Not KMRH ASOS) Kinston 76/1916 (COOP - Not KISO AWOS) Jacksonville 81/1974 (KNCA ASOS) Record High temps for 01/12 (Sunday) LOCATION TEMP/YEAR New Bern 76/2013 (KEWN ASOS) Cape Hatteras 71/1995 (KHSE ASOS) Greenville 79/2005 (COOP - Not KPGV AWOS) Morehead City 72/2005 (COOP - Not KMRH ASOS) Kinston 79/1907 (COOP - Not KISO AWOS) Jacksonville 77/2013 (KNCA ASOS) && .MHX WATCHES/WARNINGS/ADVISORIES... NC...None. MARINE...None. && $$ SYNOPSIS...MHX NEAR TERM...RF/TL SHORT TERM...TL LONG TERM...BM AVIATION...RF/BM MARINE...RF/TL/BM CLIMATE...MHX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
549 PM CST Thu Jan 9 2020 .UPDATE... Issued at 526 PM CST Thu Jan 9 2020 Updated to include 00z aviation discussion below. && .SHORT TERM...(This evening through Friday night) Issued at 200 PM CST Thu Jan 9 2020 Most of the measurable precipitation occurred east of Eau Claire and Ladysmith today as moisture depth was not deep enough to saturate over southern/central Mn. As the main upper wave moves across the region this afternoon, any chances of precipitation will end. Winds will become northwest tonight with a low stratus deck of clouds, possibly mixed with flurries at times, moving across central Minnesota. Otherwise, skies will be clear as temperatures drop back into the single digits and teens. Temperatures in west central/central Minnesota will be close to zero toward morning, and any wind above 10 mph will create wind chill values around -20F. I will highlight wind chill values in the HWO this afternoon, but not anticipating any advisory based on wind chill values holding above -25F. The next storm system will rapidly increase the cloud cover late tonight, and into Friday. Most of the moisture will be limited to mid/upper levels, but the latest RAP has deeper moisture developing Friday afternoon. As the next approaching short wave moves across the Northern Plains, there could be some light snow/flurries development in west central/southwest Minnesota. However, the much drier air advecting southward behind today`s system will likely limit any boundary layer moisture. I did introduce flurries/light snow in the far southwest/south central Mn, but even this area will be hard to see anything accumulate. Friday night will see mostly clear skies with high pressure dominating the Upper Midwest. .LONG TERM...(Saturday through Thursday) Issued at 200 PM CST Thu Jan 9 2020 Longer term trends continue the progressive flow pattern aloft. Timing and strength of embedded short waves will determine overall chances for mainly light snows and influx of colder air. Initially, models have been lifting the overall occluded surface system a bit farther to the west with each model run. Still appears better moisture and forcing will remain east of the area. Will hold onto the chance PoPs to the far east for now just in case further westward shift occurs. Then, GFS and ECMWF continue to lift short waves northeast affecting the area possible Sunday/Sunday night and again Tuesday/Tuesday night. The Sunday system looks weak and if anything did generate it should remain on the light side. The GFS is consistent with lifting a stronger wave over the area Monday night/Tuesday time frame. Depending on moisture available, this could be an advisory type event. The models diverge then into the end of the week, with the GFS continuing to drive the 1048mb ridge southeast across the area Thursday/Friday time frame following the arctic front Wednesday. The ECMWF lifts the Wednesday wave through but holds the arctic air farther north until the western CONUS trough reloads. It brings in modestly cold air in for the following weekend. The GFS has been consistent overall in timing of overall pattern, so will follow more in line with it this forecast at this point. This would bring in bitter cold air Wednesday night and lingering through Thursday night. Wind chills will need to be monitored closely if this trend continues. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 526 PM CST Thu Jan 9 2020 All sites to start out as VFR but the concern is a bank of MVFR clouds over western MN, steadily pressing east. Models are not handling these clouds well at all so have tried to use timing tools to bring the clouds into and out of the terminals this evening through the overnight hours. Will keep watch on trends and issued AMDs as necessary. By late morning Friday, ceilings are expected to be VFR between 070-100 followed by another round of mid-level ceilings in the afternoon hours. No precipitation expected. Winds will remain from the NW throughout this TAF duration, speeds around 10kt though some gustiness can be expected in the afternoon. KMSP...Will look for MVFR ceilings to move into the MSP area later this evening and am expecting them to hold in place through the Friday morning push. Some ceilings below 1700ft are likely but the cloud bases are not uniform through the incoming cloud deck, ranging from 009-025. After daybreak, improved conditions can be expected with mid-level ceilings throughout the day. /OUTLOOK FOR KMSP/ Sat...Mainly VFR. Chc -SN. Wind N-NE 5 kts. Sun...Mainly VFR. Chc -SN. Wind SE 5 kts. Mon...VFR. Wind SSE 5 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ UPDATE...JPC SHORT TERM...JLT LONG TERM...DWE AVIATION...JPC
Area Forecast Discussion
National Weather Service Phoenix AZ
450 PM MST Thu Jan 9 2020 .UPDATE...aviation discussion. && .SYNOPSIS... A low pressure system will move through the region the rest of today and exit during the day Friday. It will bring an opportunity for rain and higher terrain snow, mainly east of the Lower Colorado River Valley. There will be a very slight chance of thunderstorms. The primary time frame for shower activity will be tonight. Anticipate breezy to windy conditions at times through Friday over southeast California and southwest Arizona. Over the weekend, conditions will be dry with below normal temperatures. In fact, some of the colder desert locations will get close to freezing. Anticipate a modest warming trend during the first half of next week. && .DISCUSSION... The upper trough, currently centered over the southern Sierra Nevada mountains, continues to move southeastward. Windy conditions have developed over Imperial County. The Wind Advisory for the southwest corner of the County remains in effect until 03Z. East of there, into the Imperial Valley, there will be windy conditions but anticipate it to be too brief/marginal to expand the Advisory. Earlier cloud cover from lee cirrus and upper level diffluence effects has thinned as it shifts eastward. Cloudiness will redevelop as the QG forcing moves through this afternoon and evening. With the trajectory being largely overland, there isn`t a lot of moist advection with this system. However, with the dynamical forcing and fairly cold nature (500mb temps dipping below -25C), there will be an opportunity for precip - albeit not a lot. Ensemble mean QPF from various sources generally shows QPF favoring our eastern areas (south- central AZ) with lower elevations below one tenth and higher terrain in the 1-2 tenths range. Main window of opportunity continues to be tonight. As for metro Phoenix specifically, hi- res models have vacillated on tracking showers to the south over southwest Maricopa and Pinal Counties (as opposed to greater Phoenix area). Earlier, there were several runs of the HRRR depicting shower activity over the metro and now it seems to have backed off. The converse is true of the HREF and NAMNest. Model CAPE is not very impressive, but HREF and SREF trended upward slightly. And subjectively, it`s not uncommon to get some sort of convection with Wintertime systems despite the meager model CAPE. So, introduced slight chance of thunderstorms for south- central AZ (better chances over Pinal County than northern Maricopa). If something formed, would anticipate it to be isolated and weak. The system exits during the day Friday. Saturday through Thursday the large scale pattern remains largely unchanged with troughing over the western CONUS and ridging offshore as part of a Rex pattern. EPS and GEFS depict a system brushing northeast Arizona Saturday to reinforce cool air. Early next week, the troughing weakens a little bit for a modest warming trend. By midweek, the EPS and GEFS differ for our area with the EPS suggesting a system at least brushing the Desert Southwest and even bringing some very minor precip whereas the GEFS suggests continued warming. The NBM is leaning a bit toward the EPS and has some very low end PoPs Wednesday and Thursday - but slight chances will be very isolated and limited to higher terrain. No real temperature drop though. && .AVIATION...Updated at 2350Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: The two main aviation concerns during the first part of the TAF period will be low ceilings and elevated westerly winds. Ceilings look to drop close to 5 kft by 1Z though can`t rule out ceilings getting down to 3-4 kft temporarily as vicinity showers move through the metro. Any terminal will have a chance of seeing a shower move directly overhead primarily between 1-6Z. This would also be the time frame where`d we see the possibility for lower ceilings and thus have decided to include a tempo group to demonstrate the potential for lower ceilings in isolated showers. A very small chance for an isolated thunderstorm will exist early this evening but chances remain too low to make mention in the TAFs. Winds will be predominantly out of the west with speeds around 10-12 kts, but showers moving through may result in some variability in direction. Sometime around 6Z, we expect west winds to decrease to aob 6 kts, lingering vicinity showers to exit to the east/southeast, and ceilings to improve. There is also the possibility for patchy fog development sometime between 10Z and 16Z. This is all going to depend on how quickly we are able to clear out and how quickly wind speeds diminish. Have opted out of including mention in this TAF package, but have kept lower ceilings lingering into tomorrow morning. Southeast California/Southwest Arizona including KIPL and KBLH: Westerly winds at KIPL will continue to gust to around 30 kts through around 03-04Z, and then diminish below 10 kts for the remainder of the TAF period. At KBLH, winds will favor a northwesterly component with speeds generally remaining aob 12kts through early tomorrow morning. It then appears that breezy north- northwesterly winds with gusts close to 20-25 kts will develop tomorrow afternoon at KBLH. Expect cloud decks around 5-7 kft through around 3-4Z as a weather system moves through. Mostly clear conditions are expected to prevail thereafter with a few high clouds passing through tomorrow afternoon. && .FIRE WEATHER... Saturday through Wednesday: A cool, but mostly dry regime will continue through the first part of next week. Temperatures will remain below seasonal normals for the period. Fairly dry conditions will be seen through early next week with minimal humidities mostly ranging from 20 to 30 percent over the lower deserts. Winds will generally be light for much of the period with only occasional afternoon breezes. && .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...Wind Advisory until 7 PM PST this evening for CAZ562. && $$ DISCUSSION...AJ AVIATION...Hernandez FIRE WEATHER...Kuhlman
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