Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 07/07/19

Area Forecast Discussion
National Weather Service Denver/Boulder CO
800 PM MDT Sat Jul 6 2019 .UPDATE... Issued at 800 PM MDT Sat Jul 6 2019 Storms are rolling east/southeast from Wyoming, but have recently weakened a little, perhaps because they`re running into slightly cooler boundary layer air. We still think there is a threat of severe thunderstorms roughly along/north of a line from Wellington to Akron, with the highest probabilities of storms over the northern border area through the midnight hour. The increasing low level jet could be the kicker of additional storm development over the northeast plains late this evening. We`ll look at possible severe thunderstorm watch extension and expansion to the east. Otherwise, we were able to clear more of the Denver area and Palmer Divide from the severe thunderstorm watch, as 00Z sounding shows airmass just a bit too capped to support surface based strong/severe convection. There is one thing that could still pop a few strong/severe storms along the Front Range, and that would be an outflow boundary pushing out of the Wyoming/far northern Colorado convection. It`s a small chance, but a chance nonetheless since we did not tap into much if any of the 1000-1500 J/kg MLCAPE this afternoon along the Front Range. UPDATE Issued at 546 PM MDT Sat Jul 6 2019 Storms have been paltry so far, and a look at the latest aircraft data departing DIA shows a pretty strong stable layer near 725 mb that is effectively capping off the I-25 Corridor. Will be nice to see the 00Z Denver sounding. There were still a few storms on the plains and trying to get going over the mountains, but the main chance of any severe weather is shifting to the north and east. There is some threat with the storms firing over Morgan county and spreading eastward, but the main threat of more organized severe weather appears to be shaping up from the storms dropping east/southeast from Wyoming. These are severe already, and should try to organize into a Mesoscale Convective System (MCS) as they feed on an intensifying low level jet this evening. Most of these should remain north of a line from Wellington to Akron, and will be most likely near the Wyoming border cutting through the northeast corner of the state. Right moving severe supercells with very large hail could definitely be in the picture given existing MLCAPE near 1500-2000 J/kg and stronger shear profile to the north. We`ll keep higher PoPs and severe risk there, but have dropped the chance of storms in/around Denver. && .SHORT TERM...(This evening through Sunday) Issued at 322 PM MDT Sat Jul 6 2019 Storms developing over southern Jefferson County at this time. Two separate areas focused on by the High Res models this afternoon and evening. The first area will around the Denver area including points mainly south and east. Main concern will focus for severe will be around this areas. Weak cyclonic circulation as well around Denver which could enhance the potential for severe thunderstorms. RAP forecast soundings indicate CAPEs around 1200 j/kg with favorable directional shear as well. Precipitable water values still close to 0.80 inches as well. Later this evening, another area of thunderstorms is forecast clip the northeast corner of the forecast area around 03z. Higher CAPES/greater shear in this area. Potential for a weak tornado or two there as well. Most of the cwa has been under a jet max this afternoon which appears to have capped some thunderstorm development, but this will shift eastward this evening which aid deep convection. On Sunday, the flow aloft will remain southwesterly with continued potential for thunderstorms in the afternoon. CAPE values still healthy so potential exists for another period of severe thunderstorms with CAPES 1400 around Denver to 2400 j/kg over the northeast plains. Higher CAPE and weaker shear, but temperatures will be warmer with highs around 85. Expect the storms on Sunday to be more pulse type cells. .LONG TERM...(Sunday night through Saturday) Issued at 322 PM MDT Sat Jul 6 2019 Medium range models continue to show a couple more days of moist southwesterly flow aloft which will set up each afternoon for rounds of afternoon and evening thunderstorms. Monday looks like it will be the last afternoon of highest coverage of thunderstorms as the flow aloft turns more westerly on Tuesday that drops the mid-level moisture a little bit. The GFS is stronger than the ECMWF with the drying effects, so Tuesday and Wednesday will still need the mention of at least some afternoon thunderstorms. Cross sections from the NAM show strong drying Tuesday morning with flow at mid levels around 20 knots, but by Wednesday night a low level surge of northeasterlies and increasing moisture appear to be on their way. The ECMWF backs up this scenario. With all of the ingredients necessary for storm formation in place over northeast Colorado through the majority of the week, the cycle of afternoon and evening thunderstorms will remain in the forecast. Temperatures will reach the mid 80s to mid 90s each afternoon. Each day will need to be assessed with regard to the threat of heavy rainfall. By the end of the week, the upper ridge looks to be centered over the Four Corners area which typically leads to weak flow aloft across northern Colorado. Weak flow patterns and slow moving thunderstorms go hand in hand, so if precipitable water values increase, then the threat of heavy rainfall will also increase. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 800 PM MDT Sat Jul 6 2019 Storm threat is low over the Denver area airports due to a stable layer noted on the aircraft data moving in/out of Denver and the 00Z Denver sounding. We still see a small chance of thunderstorms if an outflow boundary from the southern Wyoming/far northern Colorado convection moves into the Front Range. Otherwise, low level moisture could slip back into KDEN late tonight/early Sunday with redevelopment of a Denver cyclone or convective push from the the north and east. So there`s a risk of stratus and IFR/MVFR ceilings 11Z-15Z. Scattered thunderstorms possible Sunday afternoon after 21Z. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Barjenbruch SHORT TERM...Cooper LONG TERM...Dankers AVIATION...Barjenbruch