Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/30/18

Area Forecast Discussion
National Weather Service Birmingham AL
713 PM CDT Thu Mar 29 2018 .UPDATE... For 00Z Aviation. && .SHORT TERM... Convective line was located just east of Heflin to Wadley to near Fort Deposit late this afternoon. An extremely brief area of rotation/velocity was displayed on radar near Marbury, where some trees were blown down. Other than that, no reports of hail or wind with this line. Ahead of this convective line, surface temperatures jumped into the 80s this afternoon. Surface based and Mixed Layer CAPE values are limited and below 1000. Bulk Shear values are good with 0-1 and 0-3 SRH good enough for some rotation. There is an nice theta-e axis ahead of the line but the theta-e advection is best south near the coast. RAP analysis and forecast soundings indicate a cap ahead of the line which is preventing any cellular activity ahead of line. Not a great deal of cloud to ground lightning with the activity either. With all this said, there is just enough to advertise a small risk of severe storms into the early evening hours for east and southeast counties. The main threat will be damaging winds or a brief tornado. Bumped the time out to around 8 pm. If anything occurs, it will be very isolated. 75 Previous short-term discussion: GOES-R water vapor imagery and global numerical model 500 mb height fields remain in agreement with their placement of a deep trough located over northeast Texas and east-central Oklahoma. To our southeast, upper level ridging continues to be analyzed over south Florida, west-central Cuba and much of the Bahamas. Toward the surface, diffuse troughing continues to be depicted in surface analyses from central Texas northeast into the central and northern Ohio River Valley. Convection from overnight and into this morning has produced a cold pool and an extensive outflow boundary from southern Tennessee southwest into eastern Louisiana. This activity continues to advance eastward into northwest and western Alabama, providing a focus for convective development. This activity so far has remained below strong and severe storm limits and lightning activity has been minimal. However, lightning activity has been increasing over the past few hours across southeast Mississippi and into interior southwest Alabama. We performed a special 18Z balloon sounding that featured a subsidence inversion around 700 mb that was acting as a cap to limit the release of convective available potential energy (CAPE). CAPE values were meager with around 360 J/kg with the bulk of that instability residing below the cap. Observed winds have increased since the 12Z sounding with near southerly flow at the surface veering to the southwest generally above 700 mb. Wind speeds were light near the surface and gradually increases to around 50 kts around 750 mb. Wind shear is sufficient for rotating storms and we continue with a non-zero tornado threat. The cap observed in the sounding is limiting the release of instability but surface observation data shows temperature readings are approaching 80 degrees across our far southeast counties. We will continue to monitor convective trends and the severe weather potential will continue across our south-central, southeast and east-central counties this afternoon and into early evening. 05 .LONG TERM... Friday through Wednesday. Surface ridging builds in over Eastern Conus behind the front on Friday with cooler overnight lows in store for Central Alabama for Friday night with skies clearing. The cooler readings don`t last though with a moderating trend expected for the second half of the weekend. A surface low over the Upper Midwest early Saturday is expected to scoot to the east-northeast by Sunday. This will in turn put the squeeze on our Eastern Conus ridge, weakening it, pushing it southeast, and elongating it from the Western Atlantic and into the Southeast U.S. This low will drag another front southeast toward the Deep South with a ridge building over the Upper Plains. However, with zonal flow setting up in the upper levels, the front is expected to stall Sunday as the main surface low pulls away. Although the front approaching should help to bring some low rain chances back to the far north for Sunday and Monday, the lower levels will not get much recovery across Central Alabama until Tuesday when onshore flow returns. Also by Tuesday, we should see the upper flow become southwest oriented as weak upper troughing sets up across Western Conus that should kick some upper shortwaves to interact with our stalled front. Decent rain chances will return Tuesday for all as a result. Higher rain chances continue into Wednesday when we may have just enough west- northwest flow develop as the upper trough moves eastward across Conus to nudge the front south of the area. The GFS has a stronger trough and is more progressive moving the upper system through while the Euro is weaker and drags its feet to bring front through and end precipitation. 08 && .AVIATION... 00Z TAF Discussion. Pre-frontal convection was approaching TOI with stratiform rain now at MGM/ANB. This rain area will continue east and southeast with rain ending at TOI after 05z. The cold front was still located well west of the area and after the rain ends, we will still have a southerly wind component. Expect ceilings to redevelop and MVFR between 05-08z, then some IFR from 08-15z. Winds will begin veering to the west and then northwest through the morning hours. This will produce ceiling rises and eventually VFR after 16-19z. Some area may experience some patchy MVFR fog, but have winds 4-6kts or more overnight. 75 && .FIRE WEATHER... The best rain chances will be through this evening as a front moves through the area. Fog and low clouds may develop again tonight, with the lowest restrictions in the southeast or south and east of the I-85 corridor. Drier conditions are expected by Friday. There are no fire weather concerns at this time. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 52 66 40 71 46 / 50 10 0 0 0 Anniston 54 66 41 71 47 / 90 10 0 0 0 Birmingham 51 66 42 73 50 / 30 10 0 0 0 Tuscaloosa 52 69 43 73 49 / 20 10 0 0 0 Calera 52 68 44 72 49 / 30 10 0 0 0 Auburn 56 70 45 72 48 / 100 10 0 0 0 Montgomery 56 72 45 74 48 / 100 10 0 0 0 Troy 56 72 45 74 47 / 100 10 0 0 0 && .BMX WATCHES/WARNINGS/ADVISORIES/... None. && $$
Area Forecast Discussion
National Weather Service Columbia SC
1023 PM EDT Thu Mar 29 2018 .SYNOPSIS... The chance for showers will increase tonight and into Friday morning ahead of a cold front. The cold front will move east of the area Friday afternoon. The return of high pressure will bring dry weather and mild temperatures for the weekend. Another cold front will cross the area around the middle of next week, bringing a chance for showers. && .NEAR TERM /UNTIL 7 AM FRIDAY MORNING/... Surface cold front is still be west of the area, but will be approaching overnight. Models still consistent with keeping conditions dry early tonight, then increase moisture and rain chances closer midnight across the western counties just ahead of the cold front. Line of showers should cross the forecast area after midnight and into Friday morning. Cannot rule out an isolated thunderstorm, but latest models showing instability is weak, and confidence not high enough to mention in the forecast. Rainfall should remain generally light to moderate, with qpf amounts around 0.25 by 12Z, but the CSRA could see slightly higher amounts. Overnight lows will only fall into the lower 60s. && .SHORT TERM /7 AM FRIDAY MORNING THROUGH SUNDAY/... An upper-level trough will lift northeast across the mid-Atlantic and northeast U.S. Friday. A cold front will cross the area Friday morning with moisture convergence and weak instability ahead of the front. Ongoing showers at daybreak Friday will move east of the area by midday. PWAT values 1.50 to 1.70 inches are forecast to decrease during the afternoon. Have indicated chance pops across the Piedmont Friday morning with likely pops across the eastern Midlands. Total rainfall amounts are expected be less than one half inch. Cannot rule out an isolated thunderstorm. High temperatures will continue above the mid and upper 70s. Models consistent with keeping conditions dry Friday night through Sunday as surface high pressure builds across the region. Near normal temperatures in the low to mid 70s Saturday will warm into the mid and upper 70s for Sunday. Nighttime lows will be in the 40s. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... Models indicate a progressive upper-level pattern during the period. A cold front will sink southward into the area Sunday night and Monday. Although the greatest chance for showers will remain north of the area...have indicated low chance pops across the north Midlands Sunday night and Monday. The frontal boundary is forecast to lift north of the Midlands Monday night. Greater rain chances enter the forecast Tuesday night and Wednesday as another cold front crosses the region. The medium- range models move the cold front offshore Wednesday night with dry weather Thursday. Temperatures are forecast to remain at or above normal. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... Expect a period of MVFR conditions in a band of showers ahead of the cold front during the early morning hours. A strong low- level jet will be associated with the front supporting low-level wind shear during the early morning hours. It will be breezy behind the front Friday. Followed the GFS LAMP and HRRR for the timing of MVFR conditions associated with a band of deeper moisture near the cold front. There may be a period of IFR conditions in possible heavier showers, but most of the guidance and upstream conditions supported MVFR conditions. Forecast soundings indicated weak instability with a diminished thunderstorm chance. There will be a strong low-level jet associated with the front and with diminished mixing because of the nocturnal timing believe low- level wind shear will be an issue. Based on the NAM and the KCAE 88D VAD wind profile trends we included low-level wind shear through the early morning hours. The GFS LAMP indicated gusts 15 to 20 knots behind the front later Friday morning and during the afternoon. EXTENDED AVIATION OUTLOOK...Widespread MVFR or IFR conditions may occur Sunday night and Monday associated with a front in the region. The front may shift north of the area by Tuesday but a moist southerly flow in its wake may result in restrictions mainly during the early morning hours. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$ SYNOPSIS...99 NEAR TERM...99 SHORT TERM...99 LONG TERM...99 AVIATION...99
Area Forecast Discussion
National Weather Service Charleston SC
1031 PM EDT Thu Mar 29 2018 .SYNOPSIS... High pressure will weaken as it moves offshore through tonight. A cold front will move through the area Friday and Friday night followed by dry high pressure through Tuesday. Another cold front could impact the area during the middle of next week before high pressure returns late next week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Late this evening: Regional radar imagery shows an impressive band of showers and thunderstorms along a cold front, stretching from western North Carolina across north Georgia to the far western Florida panhandle. This band will steadily make eastward progress through the night, though with a distinct weakening trend expected as it runs into more stable air. The HRRR seems to have a very good handle on this feature, and has been used for much of the forecast details through sunrise. Current timing forecast brings the band of showers into Jenkins County in the 4-5 am time period and to near the I-95 corridor by around sunrise. Model soundings and the climatologically unfavorable time do not provide much (if any) support for thunder, so it has been removed from the forecast. However, the low level wind field is still quite strong, so it won`t be surprising if these showers are capable of producing some strong wind gusts. The threat of severe weather though is very low given the nonexistent instability. Low level wind fields will be too strong for fog, but some low stratus could accompany the arrival of the band of precipitation. Expect a very mild night with lows in the low 60s. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... Friday: The band of showers should be right along the I-95 corridor around sunrise. However, the showers should be weakening due to the lack of instability and the fact that the primary shortwave energy in the mid/upper levels will be dampening and exiting to the north and east of the forecast area. Thunder has been removed from the forecast given the fact that instability is virtually non-existent. Showers could still produce some gusty winds thanks to the strong low level wind fields. Precipitation should come to an end around midday and the early afternoon as the showers move offshore. Thereafter, a dry forecast is in place as winds become increasingly westerly with time. Despite the cloud cover, highs are still forecast to range around the mid 70s. Cooler and drier air will filter into the area behind the front through Saturday before warmer and more humid air returns for the end of the weekend as high pressure moves offshore. Temperatures will get back above normal by Sunday when it should reach near 80 for most locales away from the coast. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... A fairly quiet weather pattern is anticipated Monday and Tuesday as high pressure over the western Atlantic favors dry and warm conditions within a southerly sfc wind. In general, high temps will approach the lower 80s away from the coast each day, while temps remain in the lower 70s near the coast. The next best chance of precip should arrive during the middle of next week with a cold front that moves through the area Wednesday. Chances of showers are possible over all areas. Dry and cooler high pressure should then arrive behind the front, with high temps generally ranging in the low/mid 70s during the second half of next week. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... VFR conditions will prevail through much of tonight. Then late tonight/early Friday morning, a band of showers along a cold front is expected to approach the terminals. Soundings and guidance both show good chances for MVFR ceilings with this feature, in addition to the showers. Have timed ceilings into KCHS at 13z and at 11z at KSAV. The band of rainfall should be diminished from its current appearance, but could still drop visibilities when it moves through KCHS and KSAV. Added a TEMPO group at both sites to account for lower MVFR conditions, but don`t think that IFR will occur. The band of showers should move east of the terminals by the early afternoon and VFR conditions should return. Extended Aviation Outlook: VFR. && .MARINE... Gusty winds have diminished in the Charleston Harbor and the Small Craft Advisory has expired there. We also have continued 6 ft seas over outer portions of the offshore GA waters where a SCA persists. With the strengthening southerly winds overnight, some 6 ft seas are expected to reach the Charleston County nearshore waters after midnight where we have a Small Craft Advisory beginning. Friday through Tuesday: A cold front will move through the waters Friday into Friday night with high pressure returning and prevailing into early next week. Elevated winds/seas are expected into Friday, especially across the Charleston County waters and offshore GA waters. Then conditions will settle briefly before deteriorating again Friday night as the pressure gradient tightens with incoming high pressure. Advisories will again be possible at least in the same areas. Overall tranquil conditions then expected through early next week, although sea fog will be possible starting Sunday as moister air moves into the area. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...Small Craft Advisory until 3 PM EDT Friday for AMZ374. Small Craft Advisory until 11 AM EDT Friday for AMZ350. && $$ NEAR TERM...BSH SHORT TERM...BSH/RJB LONG TERM...DPB AVIATION...JRL/RJB MARINE...JRL/RJB
Area Forecast Discussion
National Weather Service Peachtree City GA
920 PM EDT Thu Mar 29 2018 .UPDATE... Strong line of showers with occasional embedded thunderstorms continues to move through the forecast area without much fanfare. Have seen some interesting signatures from time to time but nothing worthy of warning on as of yet and no reports to speak of either. Some weakening noted along initial squall portion of the line but rain shield behind remains extensive with another 2 hours or so of rain for areas once leading edge moves through. Timing has been outstanding since last night with the hires models and have basically loaded in the Hrrr for the next 6 hours of pops grids in GFE. Also changed the temps to reflect a non-diurnal pattern to temperature drop for the remainder of the evening. Remainder of the forecast is on track and no additional changes are planned. Deese && .PREV DISCUSSION... /issued 738 PM EDT Thu Mar 29 2018/ PREV DISCUSSION... /issued 241 PM EDT Thu Mar 29 2018/ SHORT TERM /Tonight through Friday Night/... Pre-frontal trough/line of showers and thunderstorms has made some eastward progress this afternoon and is now entering western portions of AL. A secondary frontal boundary is currently situated from the eastern Great Lakes back through the ARLATEX. Both features will continue to push east overnight, with the pre-frontal trough beginning to impact the NW portion of the CWFA before sunset. Surface instability will be waning as the line moves through the area, but shear values remain fairly impressive. Some mid level support is likely, but lapse rates will remain marginal. So, a few strong thunderstorms are likely, with an isolated severe storm possible. Since the line is progged to weaken as it moves eastward, the most likely area for strong/isolated severe thunderstorms is mainly along and west of a line from Hiawassee to Eatonton to Americus. Damaging wind gusts are still expected to be the primary mode of severe weather. However, an isolated brief tornado is not out of the question. Locally heavy rainfall will also create the potential for ponding of water on roadways/low lying areas. The secondary frontal boundary will bring the wind shift to the NW during the day on Friday. Temps near normal are expected behind Friday`s boundary. NListemaa LONG TERM /Saturday through Thursday/... No major changes to the previous forecast. Surface high pressure will be shifting off the east coast Saturday afternoon, ushering in southerly flow across the region through the remainder of the weekend. So yes folks, this means a very pleasant weekend is in store...make it count! With the surface high off the SE coast by Sunday night, this will enable a back-door front to sag south into north GA. This will result in an increase potential for showers across this area early Monday through Monday evening. This front will eventually lift north as a warm front well ahead of the main system/cold front which is progged to cross GA late Tuesday into Wednesday. There continues to be model variability with the timing of the front...GFS the quicker of the solutions (Tuesday night through Wednesday morning) while ECMWF is a bit slower (Wednesday morning through the evening hours). Given this 12-hour difference in model guidance spread, have hedged...bringing the front through mid-day Wednesday. If the ECM comes to fruition, crossing north/central GA during the afternoon, we may then be dealing with a higher probability of thunderstorm development. Although, it should be noted that the overall extent of instability looks minimal at this time. High pressure will build back into the area late Wednesday into Thursday. Temperatures are going to be around climo this weekend (highs in the low 60s across far north GA to low 70s across central GA), eventually rising well above normal ahead of the next front on Wednesday. Temperatures on Tuesday will climb to around 80 in the metro and mid 80s across southeast GA. Behind the front, temperatures will sink back closer to climo for Thursday. 26 AVIATION... 00Z UPDATE... As far as lines of storms are concerned, this one has been very well behaved timing wise with models indicating a 00Z start time for Atl for the last 24 hours. Looks to be just after that but close considering and still anticipating same impacts with occasional strong gusts and lightning. Large rain shield begins the storms so may take awhile to shift east of the terminals. MVFR to move in shortly behind initial squall and stay with us through the overnight and most of the morning hours Friday. Winds to be quite strong Friday afternoon and have included some 14G24kts. //ATL CONFIDENCE...00Z UPDATE... Medium on TSRA duration. High on remaining elements. Deese && .PRELIMINARY POINT TEMPS/POPS... Athens 57 71 41 70 / 80 20 0 0 Atlanta 55 66 42 69 / 100 10 0 0 Blairsville 51 59 33 64 / 100 10 5 0 Cartersville 52 63 38 68 / 100 10 0 0 Columbus 59 71 46 73 / 90 10 0 0 Gainesville 54 65 40 66 / 100 10 0 0 Macon 60 72 44 72 / 70 20 0 0 Rome 52 63 38 69 / 100 10 0 0 Peachtree City 55 68 40 70 / 100 10 0 0 Vidalia 64 74 48 74 / 70 60 0 0 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Deese LONG TERM....Merritt AVIATION...Deese
Area Forecast Discussion
National Weather Service Houston/Galveston TX
915 PM CDT Thu Mar 29 2018 .DISCUSSION... A weak cold front was crossing the area and at 900 PM, the front was located along a Jasper to Liberty to Giddings line. Some of the short term guidance showed some potential for a few weak showers along the boundary tonight but the upper flow is weakly confluent and 00z soundings show a dry moisture profile with PW values under an inch. That said, it looks like a line of weak showers is trying to develop across hardin and Liberty counties. Any precipitation that does develop will be light, spotty and short lived. Cooler and drier air will filter into the region behind the front and morning low temps should fall into the 50`s inland, mid 60`s coast. Sunny skies are expected on Friday with seasonal temperatures. Tweaked sky grids but the rest of the forecast looks on track. 43 && .HYDROLOGY... Canceled the flood warnings for Spring Creek, Davidson Creek and Mound Creek earlier tonight. No change in status on other area rivers. 43 .PREV DISCUSSION... /ISSUED 644 PM CDT Thu Mar 29 2018/ AVIATION... VFR conditions on tap through the TAF period. A lingering FEW/SCT mid level deck will continue to make its way off the coast overnight, leaving behind high clouds. A cold front will continue to push its way through the region this evening and winds will increase out of the N/NE by the morning hours, with wind speeds between 7-12 kts inland and closer to 15kts along the coast at GLS. Winds will subside and turn out of the NE by the afternoon and skies will clear, as a region of high pressure pushes in from the north. Hathaway PREV DISCUSSION... /ISSUED 353 PM CDT Thu Mar 29 2018/ DISCUSSION... Mainly quiet and dry weather with temperatures rising to around 80 each day through the weekend. Also look for onshore winds to return this weekend, boosting humidity and gradually bringing back rain chances early next week. Best chances for rain next week will come with the passage of a cold front. NEAR TERM [Through Tonight]... Skies have cleared across much of the area this afternoon, though some trailing cirrus lingers along the Gulf coast, and a bit of lower cloud north of College Station and Huntsville is gradually scattering out. While dewpoints have mixed out some today, much drier air hasn`t really pushed in, which may help lows tonight from falling perhaps as far as they could. Drier air does look to advect in just early enough that points well north of Houston should still fall to near seasonal averages. Short range models have been fairly insistent in sparking some showers overnight - with the HRRR occasionally being pretty aggressive. This looks to occur on what could be called a reinforcing cold front, and while it is a plausible scenario, not so convinced we`ll actually see measurable precip. Compromise by introducing some very low PoPs and putting a chance of sprinkles in the weather grids. SHORT TERM [Friday Through Saturday Night]... Given recent rain, and in some places flooding, have tempered highs just a little bit for tomorrow, holding temperatures in the mid to upper 70s across Southeast Texas. Surface high pressure looks to drift across the area, returning onshore flow to us by Friday night or Saturday. Meanwhile, ridging just aloft should build in around or just east of Galveston Bay. This should help highs boost up to around 80 degrees to start the weekend, along with gradually increasing dewpoints. LONG TERM [Sunday Through Thursday]... By Sunday, high pressure at the surface through 850 mb will be in place to our east, along with a building 500 mb ridge over Mexico and largely zonal flow (with just a small hint yet of northwest flow) over us. While the pressures/heights aren`t quite there, the qualitative appearance is...uncomfortably...close to summer. Fortunately, the difference is enough that the end result looks to be high temperatures just on the high side of seasonal averages. The onshore flow will boost dewpoints, keeping overnight lows more noticeably above that average. This may give the mornings a bit of a hint of mugginess, but still well shy of the true summer dog breath. Some of the guidance does start light showers as early as Sunday, but will hold off until Monday for now as return flow seems fairly modest at this point. Finally, we`ll see change coming early next week. The GFS and Euro are perhaps surprisingly similar in their upper pattern, but that consensus breaks at the surface. The faster GFS brings the next front through Tuesday night. On the slow end, the Euro waits later into Wednesday to bring the front through. Both drop a quarter to an inch of QPF with the front. However, with precipitable water values coming up to 1.7 or 1.8 inches in the GFS, would not get married to light totals just yet. Timing may also be important for severe potential for available instability. Given the range and scenarios posed by the guidance, predictability of specifics is probably not wise at this point. Suffice to say, the front will bring the best chance of rain for the next several days, and determining its impact seems likely to be the main challenge of the forecast going forward. MARINE... Light winds this afternoon with slowly subsiding seas...will extend the SCA for the 20-60nm waters through 00z. Winds will become north and northeast tonight as the cold front pushes off the coast around 3-5 am. SCA/SCEC conditions may develop in the wake of the front 13- 21z Friday. High pressure slides away quickly east and winds become easterly late Friday. Saturday southeasterly flow sets up and continues in the 5-15kt range through Monday. A s/w passing by to the north will increase the gradient and SCA conditions should return. 45 HYDROLOGY... Minor to Moderate river flooding continues along the Trinity and San Jacinto basins, as well as Lyons Creek in the Brazos River basins. Minor to Major river flooding is still forecast over the next several days. Latest rivers observations show runoff and routed water responding well in many locations, giving more confidence to the updated forecasts. Several changes were made this afternoon to account for additional rises. Changes include raising the Trinity River at Goodrich and Bedias Creek at Madisonville to Major flood, the Trinity River at Riverside and Moss Bluff to Moderate flood, and the Trinity River at Romayor to Minor. Inundation of structures expected near Goodrich and Liberty along the Trinity. Inundation of roads occurring and expected along the Trinity and San Jacinto basins. && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 55 75 54 80 61 / 10 0 0 0 0 Houston (IAH) 58 78 54 79 62 / 10 0 0 0 0 Galveston (GLS) 64 74 64 74 68 / 0 0 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...Small Craft Advisory until 10 PM CDT this evening for the following zones: Waters from Freeport to the Matagorda Ship Channel from 20 to 60 NM...Waters from High Island to Freeport from 20 to 60 NM. SMALL CRAFT SHOULD EXERCISE CAUTION until 4 AM CDT Friday for the following zones: Waters from Freeport to the Matagorda Ship Channel from 20 to 60 NM...Waters from High Island to Freeport from 20 to 60 NM. && $$ Discussion...43
Area Forecast Discussion
National Weather Service Indianapolis IN
1059 PM EDT Thu Mar 29 2018 .UPDATE... The AVIATION Section has been updated below. && .SYNOPSIS... Issued at 227 PM EDT Thu Mar 29 2018 Low pressure will exit Indiana tonight...bringing a short break to the rainy week. High pressure over the southern plains is then expected to build across the Ohio Valley on Friday...bringing the work week to an end on a dry and slightly warmer note. A quick moving cold front is then expected to sweep across Indiana on Saturday from the northern Plains. This will once again bring showers back to the forecast for Saturday afternoon as the from passes. High pressure will then return to the are on Sunday...bringing dry weather. The Active weather pattern will continue on Monday as yet another front returns to the area from the southwest...along with rain chances. && .NEAR TERM /Tonight/... Issued at 227 PM EDT Thu Mar 29 2018 Surface analysis early this shows a broad area of low pressure stretching from NE Ohio to SE Indiana and SW to Arkansas...straddling a frontal boundary. Water vapor imagery shows a plume of tropical moisture stream in from East TExas into the Ohio Valley ahead of a broad trough over the Central Plains. Radar showed extensive rain showers stretching from Western PA...scattered across Ohio to Indiana...KY and TN. Models suggest the precipitation upstream will continue to push across much of Central Indiana this Evening. Time heights show favorable lift with good moisture and forecast soundings show good saturation through the column through the evening hours. The GFS and NAM suggest the upper trough axis to the west does not pivot across Central Indiana until after 12Z Fri. Thus will keep high chances for rain in the forecast this evening...given the favorable dynamics remaining in place and the radar returns upstream. HRRR suggest the precipitation band should begin to drift east overnight...trending toward an end of the precipitation. Forecast sounding do hint at some dry air within the column overnight. Thus will trend pops lower overnight. Given the expected clouds but cold air advection...will stick close to the forecast builder blends on lows. && .SHORT TERM /Friday through Sunday/... Issued at 227 PM EDT Thu Mar 29 2018 THE GFS AND NAM suggest the NW flow aloft persists on Friday as the the trough axis aloft shifts eastward. Models suggest subsidence and High pressure developing in the back side of the trough as a dry column is seen within the time heights and forecast soundings. Models suggests surface high pressure in place across the Tennessee and Kentucky river valleys. This looks to persist through Friday Night as the High drifts east of Central Indiana to the Virginias by Saturday morning. Thus will trend toward a partly cloudy sky and blend on temps Friday and Friday Night. GFS and NAM suggest another short wave and associated cold front pushing out of the upper midwest on Saturday. Models suggests good lower level convergence and good moisture in place ahead of the frontal boundary. Forecast soundings show saturation within the lower levels. Thus will trend pops at or above the forecast builder blends mainly during the afternoon and perhaps the early evening hours on Saturday Night. The quick NW flow looks to persist on Sunday night and Monday...allowing the earlier cold front and associated dynamics to quickly exit. Forecast soundings quickly trend toward a dry column on Sunday Night and early monday. Thus will trend toward a dry forecast at that time. However models are suggesting a return of a warm front and mid level moisture arriving with warm air advection on Monday afternoon. Confidence on this feature is low at this time and will try trend toward a dry forecast for now. && .LONG TERM /Sunday Night through Thursday/... Issued at 235 PM EDT Thu Mar 29 2018 Models suggest a couple of frontal systems will impact the area during the long term period, one a bit stronger early to mid week and another much weaker later in the week. Vast majority of the precipitation will be in the form of rain. Temperatures will remain largely below normal during the period. Blended initialization handled things relatively well and required only few minor tweaks. && .AVIATION /Discussion for the 30/03Z TAF Update/... Issued at 1053 PM EDT Thu Mar 29 2018 Update... MVFR conditions are prevailing at KIND. Previous Discussion... Widespread rain will continue to linger into the night. Conditions are starting to trend more toward MVFR, but IFR category cannot be completely ruled out, yet, as visibilities and ceilings still fluctuate a bit. It won`t be until tomorrow morning when conditions start trending toward the MVFR/VFR mark. Meanwhile, winds will generally be northerly at 5 to 11 kts. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...Puma NEAR TERM...Puma SHORT TERM...Puma LONG TERM...Nield AVIATION...TDUD
National Weather Service Jackson KY
1025 PM EDT Thu Mar 29 2018 .UPDATE... Issued at 1025 PM EDT THU MAR 29 2018 The steadier rains continue to progress east and out of watch area. After calling around to the counties in the flood watch and noting no problems have gone ahead and dropped the watch. Additional showers will be possible through the night, but they should not be substantial enough to result in any high water issues. With this update have also removed the thunder threat and fine tuned the temperatures per the latest guidance and obs. These grids have been sent to the NDFD and web servers along with an issuance of a fresh set of zones and new HWO. UPDATE Issued at 730 PM EDT THU MAR 29 2018 23z sfc analysis shows low pressure moving through the central Appalachians with a cold front to the west of the area. The bulk of the rain from this looks to be passing through eastern Kentucky currently with any additional rains overnight likely to be light according to the HRRR and NAM12. Accordingly, will probably cancel the Flood Watch early once the main rain area departs over the next hour or so. Even so, higher returns and heavier rains fell along and north of the Mountain Parkway earlier this evening necessitating a flood advisory for those areas. This runs through 9:30 pm. Would look to hold on to the Watch until the flood advisory ends. Otherwise, temperatures are fairly uniform across the JKL CWA - generally in the mid to upper 50s along with similar dewpoints. Meanwhile, winds - which did gust to over 30 mph along the earlier line of heavy showers - have settled most places to between 5 and 10 mph from the south to southwest with occasional gusts to 20 mph. Have updated the forecast mainly to fine tune the PoPs and Wx through the night along with a touch up to the T and Td grids per the latest guidance and obs/trends. These updated grids have been sent to the NDFD and web servers. An updated FFA will be issued shortly. && .SHORT TERM...(This evening through Friday night) Issued at 254 PM EDT THU MAR 29 2018 Will continue with flood watch through 8 AM Friday in all current counties. This continuation has been coordinated with neighboring WFOS. Overall flood threat does not appear too great at this point, but with rain on our doorstep and at least the potential for a few thunderstorms this evening it is prudent to continue with the watch. This will also be in good agreement with the neighboring WFOs. QPF from 18Z this afternoon through 12Z Friday is an inch or less across the area. This would not cause problems as long as it is spread out, but still have concern for a few thunderstorms. Stability is not that great but it appears there will be a small window from late afternoon into the evening where a few storms could occur. SPC short range thunderstorm outlooks are all in the 10 to 40 percent range, and latest blended model guidance for this evening is even less. There were some lightning strikes over southern IL earlier today, but recently all strikes have been over southern MS and southern AL. So the threat for thunderstorms is low, but given saturated conditions if a thunderstorm was to develop and drop heavy rain some localized flooding could occur. Waves of low pressure have continued to ripple northeast along the front to our west which has been nearly stationary. However with the passage of one last wave this evening, the front will finally move east across the forecast area tonight as a cold front. There could be some lingering showers behind the front into Friday, but the threat for significant rains will end with the frontal passage tonight. Much cooler air will spread into the area for Friday. Cool high pressure will build into the OH valley by Friday evening, with the high drifting east across the area overnight, and ending up off to our east by 12Z Saturday. Based on the synoptic set up we should see a ridge valley temperature difference develop Friday night. This idea is supported by the COOP MOS which has some lows into the upper 20s, which is colder by several degrees than the model blend low temperature forecast for Friday night. With all that in mind have introduced some colder minimums for Friday night in valley locations, but have not gone as cold as the MOS Guidance would suggest. Coordination with the University of Kentucky Agricultural Weather Center has taken place and based on their field reports frost/freeze headlines are not yet needed here in eastern KY. As such there will not be any headlines for any frost or freeze this weekend in our area. This has also been coordinated with the neighboring WFOs. We will continue to highlight the frost threat in the HWO and include frost in the NDFD if need be. The University of Kentucky indicates we`ll probably need to begin headlining frost/freeze events after the first full week of April. .LONG TERM...(Saturday through Thursday) Issued at 319 PM EDT THU MAR 29 2018 The extended portion of the forecast will begin on Saturday with a rather progressive upper level pattern in place over the country. Persistent ridging over the western CONUS will lead to a broad longwave trough over the central and eastern CONUS. A brief period of high pressure will keep the area dry for much of the day on Saturday. However, the progressive pattern mentioned will bring another front in from the northwest. This will bring a chance of showers late Saturday and lasting into Sunday morning. The question that follows is the temperatures behind the front for late Saturday night as some precip over the Bluegrass may mix with snow. The ground however will likely be too warm for any accumulation. The convective nature of the showers however will likely mean getting snow as high as 35 degrees and mixing with a bit higher. The front pushes through the area by Sunday morning but ridging over the southeastern CONUS causes the front to stall along the KY and TN border becoming a stationary boundary for Sunday and Monday. During this period, weak disturbances will lift north out of the Gulf and across the TN valley bringing a continued chance of showers through Monday. Surface temperatures are pretty warm during this period but cant rule out a few flakes on the cold side of the precip to the north in Bluegrass for Monday morning. By Monday night into Tuesday, the next system develops and moves into the OH Valley. Models suggest a well developed system as a disturbance and decent surge of moisture lifts north out of the Gulf combined with a strong shortwave passing to the north over the Great Lakes region. This system will push a strong cold front across the area by Tuesday night into Wednesday. This will look top be another wet period in the forecast. Model soundings do hint at some instability but the uncertainty too high to put in thunder at this time. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) ISSUED AT 810 PM EDT THU MAR 29 2018 A final wave of low pressure is moving northeast this evening with the formerly stationary front finally beginning to push its way east. this will pass across the forecast area tonight with winds shifting from the southwest to the northwest. VFR or MVFR conditions will hold for another couple of hours at most TAF sites ahead of this boundary. However, in the wake of this current band of showers (and potential thunderstorms), conditions will deteriorate. With this, ceilings are expected to lower to IFR, with IFR cigs remaining in place into Friday afternoon before improving from west to east. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...SBH LONG TERM...SHALLENBERGER AVIATION...GREIF
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
644 PM CDT Thu Mar 29 2018 .SHORT TERM... (Through Late Friday Afternoon) Issued at 252 PM CDT Thu Mar 29 2018 It looks like the trof/weather system that has been affecting us for a while will finally lift out of the area the next 12 hours. However we have to get through the next 12 hours. If it were colder I would say we have a nice winter storm with a good deformation zone developing, but it is warm so all we have to worry about is rain. That said, the HRRR and CONSHORT agree in holding some pops across parts of east and southeast MO and southern IL through the evening. It will likely end up being a narrow band, but will keep at least chance pops going through 06z for much of the southern part of the CWA. Drier air is filtering in from the north so improvement is on the way for Friday. Patchy fog may be an issue overnight given the wet ground, but will let the evening shift tackle that as it develops. With cloud cover holding in for much of the are overnight, have raised low temperatures to the warmer MAV levels. Guidance for Friday looks good. This will be my last forecast shift for the NWS as I am retiring as of March 31. It has been a pleasure working with and serving everyone across the 46 county area of the NWS St. Louis. Take Care. Jim Kramper .LONG TERM... (Friday Night through Next Thursday) Issued at 252 PM CDT Thu Mar 29 2018 Active pattern will continue over the weekend into next week as global models show that the upper flow will be semi-zonal over Missouri and Illinois. The first chance of rain will come late Friday night into Saturday night as GFS/ECMWF/Canadian show a shortwave trough and attendant cold front dropping east southeastward from the northern Plains into Missouri/Illinois. After this first shortwave moves quickly off to the east, a second shortwave will move across southern Missouri and far southern Illinois late Sunday into Sunday night bringing another chance of rain with some snow possibly mixed in based on forecast soundings. The best chance for showers will be Monday into Tuesday ahead of deeper trough that will move across the area on Tuesday night. There will be stronger moisture transport ahead of it along with some instability, so kept the chance of thunderstorms Monday afternoon into Tuesday. Wednesday looks dry at this point behind the upper trough as a surface high moves across the area before the next upper trough and attendant front affects Missouri and Illinois next Thursday. Temperatures still look below normal through this period based on clouds and rain chances as well as the ECMWF MOS and the GEFS mean temps. Britt && .AVIATION... (For the 00z TAFs through 00z Friday Evening) Issued at 639 PM CDT Thu Mar 29 2018 Rain and IFR conditions will continue to move east and southeast of the STL Metro terminals this evening. MVFR conditions will continue overnight though as low level moisture progs from model guidance depict saturation through 12Z. Can`t rule out some patchy fog and drizzle developing overnight. Improving conditions expected on Friday with the sun making an appearance by afternoon. Light northwest wind will back to the west on Friday. VFR conditions to continue at KUIN with improving ceiling height at KCOU this evening. SPECIFICS FOR KSTL: Radar depicts the precipitation shield is rapidly weakening and starting to shift to the east/southeast. This trend will continue with MVFR ceiling conditions likely continuing overnight given abundant low level moisture in the atmosphere. Can`t rule out some patchy fog and light drizzle also developing overnight. Conditions will rapidly improve tomorrow, with scattering cloud cover by afternoon. Northwest wind will back to the west. CVKING && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
Area Forecast Discussion...UPDATED
National Weather Service Memphis TN
918 PM CDT Thu Mar 29 2018 .UPDATE... Midevening GOES East water vapor imagery showed a broad midlevel trof entering the mid MS River valley. A narrow line of showers moved through the Midsouth earlier this evening, preceding a midlevel drying and reduced low and midlevel lapse rates. 00Z NAM low and midlevel lapse rates are depicted to remain low during the overnight, likely limiting additional shower potential late this evening and overnight. Forecast was updated earlier this evening, reflecting reduced measurable rain chances. PWB && .PREV DISCUSSION... /issued 619 PM CDT Thu Mar 29 2018/ UPDATE... Updated to include 00Z Aviation Discussion. PREV DISCUSSION... /issued 322 PM CDT Thu Mar 29 2018/ DISCUSSION... A cold front has just pushed into Northeast Arkansas at this time. A lull in the rain is occurring across much of the area as the rain associated with an old outflow boundary has pushed east with the exception of some lingering showers in Monroe County, Mississippi. Meanwhile, a line of convection is beginning to develop across Eastern Arkansas ahead of the approaching cold front. The latest run of the HRRR shows this line progressing eastward across the Mid-South through early this evening thus one more quick round of rain can be expected across the area. Temperatures will drop behind the front as it pushes across the area late this afternoon into the evening. Clouds will linger and may not clear out until noon on Friday. Lows will be in the mid to upper 40s. Highs on Friday will be in the upper 50s to mid 60s. High pressure will settle over the Mid-South by Friday afternoon into the Friday evening. The high will quickly shift east. Thus winds may turn around back to the south during the overnight hours. Lows will be in the upper 30s to upper 40s. Another cold front will then approach the Mid-South by mid-day Saturday bringing back chances for rain to Northeast Arkansas, the Missouri Bootheel, and Northwest Tennessee. The front will really slow up in its progression southward thus rain may not get into Memphis until late Saturday Night into Sunday morning depending on what model you look at. The front is expected to stall out somewhere over the Mid-South before lifting back to the north as a warm front on Monday. The front will return as a cold front, moving through the Mid-South Tuesday into Tuesday Night. Uncertainties with timing and location of the front will result in lower confidence in the forecast especially with rain chances during the Sunday Night through Tuesday Night. High pressure will then build back into the Mid-South on Wednesday and will bring cooler and drier conditions to the region. KRM && .AVIATION... 00Z TAFs Cold front will move across the area this evening. Gusty S/SW winds will veer NW with frontal passage then diminish to 8-10 kts. VFR condition swill deteriorate back to MVFR conditions tonight into Friday morning then improve to VFR conditions by Friday afternoon. CJC && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion
National Weather Service Marquette MI
749 PM EDT Thu Mar 29 2018 .SHORT TERM...(This evening through Friday) Issued at 342 PM EDT THU MAR 29 2018 WV imagery and RAP analysis indicated a mid/upper level trough from Hudson Bay through the cntrl CONUS resulting in cyclonic wsw flow through the nrn Great Lakes. Any lingering clouds over the north supported by onshore flow of colder air with -12C 850 mb temps will dissipate this evening as sfc ridging and drier air move into the area, per upstream vis loop trends. Tonight, favorable radiational cooling conditions until clouds increase over the west late will still allow temps to drop toward the lower end of guidance with readings into the lower teens inland west to around 20 along the Great Lakes. Friday, a clipper shortwave moving out of the nrn plains will bring an area of light snow into the region. With only weak to moderate 700-300mb qvector conv or fgen associated and little moisture inflow with this feature, QPF at or below models consensus in the 0.01-0.05 inch range is expected. This would support snow amounts of an inch or less up to 18z over the far west and btwn 18z-24z over the cntrl and east. With temps from the the upper 20s to around 30 north and to near 40 south, enough warm air is expected south for rain or a mix or rain/snow. .LONG TERM...(Friday night through Thursday) Issued at 406 PM EDT THU MAR 29 2018 Still some model differences for moderate to heavy snow potential this weekend, especially for the east half; however, widespread accumulating snowfall is expected across much of the Upper Peninsula. Friday night into Saturday: The next chance for accumulating snowfall will slide into the Upper Great Lakes region late Friday night through at least Saturday morning. The GFS/Canadian are similar in taking the surface low just south of the U.P. or across Menominee county as a stronger shortwave slides through the area. The latest NAM and EC has the low taking more of an east to northeast trek, which would bring the low center across the central U.P. into eastern Lake Superior. Either of these solutions would bring moderate to heavy snowfall to the western half of the U.P; however, the GFS/Canadian solution would favor all of the U.P. seeing moderate to heavy snowfall. The increased forcing along with added moisture streaming from the Gulf, will allow for a swath of at least moderate snow to develop across much of Upper Michigan, again exact trek will dictate where the heaviest snow falls. Models are painting around a half inch or possibly a bit more across much of Upper Michigan starting late Friday night, likely after 06Z, and especially Saturday morning into early Saturday afternoon. This would bring a widespread 4 to 8 inches of snow to much of the area, heaviest over the northwest U.P. In addition, 850mb temperatures are progged to be in the -13C to -16C range by late Saturday morning/early afternoon, which combined with northeast to north winds would allow for lake enhancement and orographic lift. This may help to increase snowfall totals over the high terrain of the north- central U.P. Of course, this depends on exact placement of the low pressure system and wind direction. Blowing snow would also be an issue as the tighter gradient depicted would allow for wind gusts around 30 to 40 mph. At this point, with the aforementioned differences in low trek, will hoist a winter storm watch for at least the west half of the U.P., where confidence is higher in the heavy snow potential, as painted out by each of the models. Saturday afternoon through Sunday night: On the back side of the system, with general troughing in place, chilly airmass is expected across the Upper Great Lakes with H85 temps -15c to -20c range. This will lead to an uptick in lake effect snow for northwest to west wind snow belts Saturday afternoon through Sunday night. Could see some moderate lake effect snow accumulations for the aforementioned favored snow belts. Otherwise, much colder air will remain in place across the area with temperatures around 10 degrees below normal. Rest of the extended: Models are trending toward an even colder pattern for early next week as a colder pool of air is expected to spill southward across the Upper Great Lakes. This would lead to additional, intermittent, lake effect snow chances across the area. Locations impacted and extent of the impact will be centered on the low level wind direction and ice coverage. At this point will stick with a consensus of the models from early to mid week, giving intermittent chances of snow. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 748 PM EDT THU MAR 29 2018 VFR cigs will prevail thru the evening at KIWD/KCMX/KSAW. Late tonight, increasingly colder air moving across Lake Superior on wnw winds should result in development of lake effect clouds/MVFR cigs at KCMX and perhaps some flurries or -shsn at times. These lower clouds should scatter out by late Fri aftn. Similar conditions are expected at KIWD, but with a passing disturbance Fri, a period of -sn/MVFR vis is expected late morning into early aftn. At KSAW, VFR conditions will likely continue thru Fri morning before some -sn/MVFR conditions develop in the aftn due to passing disturbance. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 342 PM EDT THU MAR 29 2018 Northwest winds of 20 to 30 knots over the eastern portion of Lake Superior will abate this evening. Winds will then remain generally below 25 knots across the entire lake through Friday evening. Winds will increase markedly early Saturday as a low pressure system approaches the area. Northeast winds of 20 to 30 knots are expected across Lake Superior early Saturday before backing northwesterly Saturday afternoon. Northwesterly gales of 40 to 45 knots are possible across eastern Lake Superior Saturday afternoon and evening. A few areas of heavy freezing spray are possible Saturday afternoon/evening, as well. Winds of 20 to 30 knots are then expected on Sunday, and below 20 knots on Monday. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Winter Storm Watch from late Friday night through Saturday afternoon for MIZ001>005-009>011-084. Lake Superior... Gale Watch from Saturday afternoon through Saturday evening for LSZ248>251-265>267. Lake Michigan... Gale Watch from Saturday afternoon through Saturday evening for LMZ248-250. && $$ SHORT TERM...JLB LONG TERM...KEC AVIATION...Rolfson MARINE...BB
Area Forecast Discussion
National Weather Service San Diego CA
849 PM PDT Thu Mar 29 2018 .SYNOPSIS... High pressure aloft will build over California through Friday and bring fair, dry and warmer weather over southern California. Areas of night and morning low clouds and fog will occur near the coast, with locally dense fog possible. Weak low pressure will bring increasing high clouds and coastal low clouds, and cooler onshore flow this weekend through early next week. It will be a little warmer again around the middle of next week as another ridge of high pressure moves through California. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... ...Update... Patchy low stratus is developing just off the coast. Although there is an offshore synoptic pressure gradient, that will lessen in time overnight and become onshore on Friday. The HRRR continues to show dense fog along the coast, especially the San Diego coast, so the dense fog in the forecast looks good for the overnight. No changes are needed to the forecast this evening. See previous discussion below for further forecast details. ...Previous Discussion (Issued at 200 PM PDT Thu Mar 29 2018)... After the stratus/fog dissipated this morning, mostly sunny skies prevailed today with temperatures a little above normal, mostly in the 70s west of the mountains, with some lower 90s in the lower deserts. Aircraft soundings show the inversion in the 500-700 foot range, and with the inversion expected to continue tonight or even lower slightly under the subsidence of the ridge moving in from the west, there could be dense fog along the coast. Confidence of timing and exact locations/elevations is somewhat low, but midnight-8 AM and within about 5 miles of the coast are the most likely times/locations for dense fog. Away from the coast, clear skies with warmer weather and moderately low humidity will prevail through Friday as the high builds and some very weak offshore flow develops, though the local WRF shows wind gust potential mostly under 30 MPH Friday morning, mainly San Bernardino County. After the ridge Friday, a weak trough, mostly disconnected from the polar jet over Washington/British Columbia, will be off the coast Saturday, slowly moving towards the So-Cal coast by Sunday night/Monday. This will bring high clouds but most likely no precipitation. The marine layer should deepen by Sunday some and result in more widespread coastal/valley stratus but less coastal fog. Eventually the low will move east, and with a high pressure ridge, albeit fairly low amplitude, following. That will result in a warming trend again with temperatures a little above normal. The pattern will be fairly progressive due to the relatively low amplitude of the troughs/ridges, so that high likely will not last more than a couple days as there could be a deeper broader trough moving in late next week. This could bring precipitation the following weekend, 7-8 April, though confidence is low for that. && .AVIATION... 300330Z...Coastal areas: Low clouds and fog returning to the coast through 06Z, then spreading 5-10 inland miles through 14Z Friday with bases between 200 and 700 ft MSL. Vis restrictions of 1/2 mile or less expected on the coastal mesas including KCRQ. There is a moderate potential for 1 mile vis or less at KSAN and KSNA between 06Z and 15Z Friday. The fog should dissipate by 17Z Friday. Valleys, Mountains and Deserts: clear skies and unrestricted visibility tonight and Friday. && .MARINE... Areas of dense fog tonight and Friday morning, and again Friday night into Saturday morning. && .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...Gregoria (Update)/Maxwell (Prev Discussion) AVIATION/MARINE...Moede
...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Friday) Issued at 345 PM CDT Thu Mar 29 2018 Broad cyclonic flow continues over the central CONUS with a stronger wave pushing east across the southern Plains with a weaker wave over western portions of South Dakota and Nebraska. Low-level cold air advection is keeping stratus in place over much of the local area though some clearing has occurred in the northwest with temps recovering somewhat. Scattered high-based showers were reaching central portions of Nebraska and western Kansas but this wave should weaken and enter a less favorable environment for continuation. A smaller-scale upper wave was entering western Missouri and helping generate a small area of light precip in the Jefferson county area at 20Z. HRRR and RAP and been consistent with this area limited to far eastern counties before diminishing as well as this wave exits. Surface high pressure builds into the area tonight but models are consistent with some northerly component remaining in the boundary layer. Stratus south continue to push southeast with high cloud moving off for several hours of fairly clear skies, but enough wind looks to keep fog chances low. Another round of high cloud looks to move through Friday but increasing southwest winds behind the exiting high should finally bring a mostly sunny day and highs in the upper 50s to lower 60s. .LONG TERM...(Friday night through Thursday) Issued at 345 PM CDT Thu Mar 29 2018 The next stronger wave in the northwest flow brings some increase in lapse rates in warm-air advection for Friday night, with moisture return aloft potentially leading to some shower activity in the northeast where saturation is greater. This wave brings another cold front Saturday with still a wide range in highs likely, but highs will likely again struggle to break the 40s in the north. Attention Saturday night into Sunday continues to be an a narrow band of enough saturation and frontogenesis that stretches ESE into the area. Dry air under this should limit intensity of precip but could still see some light snow accumulations if a band can be sustained. The next wave enters the northern Plains Monday night and on toward the local area Tuesday, but remains positively tilted. At this point timing looks unfavorable and capping large enough for limited daytime thunderstorm concerns but will keep a thunder mention Monday night with warmer temps for Monday. Northwest flow looks to persist into the mid week and continues to present occasional chances for mainly light precip. Temps breaking seasonal normals are unlikely beyond Monday night. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 637 PM CDT Thu Mar 29 2018 VFR cigs should scatter out by 01Z. Expect vfr conditions for much of the period, save from 09Z-13Z where mvfr vsbys are possible due to mist at the terminals as soundings keep the lower boundary layer mixed tonight so not anticipating ifr or lifr with fog. Will continue to monitor for next issuance. Winds light north becoming southwest under 10 kts by 19Z. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...65 LONG TERM...65 AVIATION...53