Talk about current conditions, forecast analysis, forecast corrections/updates and general thoughts regarding the progression of weather.
Forecast discussion blog
Temperatures are currently well below freezing, and temperatures will go down to the single digits tonight with clear skies. The temperatures will remain below average for the week with a high in the lower 20s tomorrow. A high pressure system will settle in tomorrow. As the high remains over the area dry conditions and below normal temperatures are expected for the beginning of the week.
For the workweek, the polar vortex will make its presence once again in the upper Great Lakes and this will allow cold arctic air to spill south into the area for this period. Expect highs to remain below normal through the work week. Central Indiana is projected to be on the cusp of this air mass and this will allow the northwest flow to track through the area during this period. This may heighten our chances of seeing Alberta Clippers which could possibly deliver some snow to area before it exits. With that being said will keep pops in the forecast for Monday night-Tuesday as a weak disturbance may deliver some snow showers to the area during this time. Other than that, the rest of week looks dry for now, however, will still watch for the possibility of aforementioned clipper systems to change this prediction.
Temperatures are currently hovering around freezing and narrow band of precipitation is currently tracking through the area. A shortwave and frontogenesis are helping to enhance the precipitation occurring in the area and thus having likely POPS for precipitation is still justified. Right now, it appears that 1-3" of snow accumulation will still occur before the morning hours tomorrow. Still looking at high pressure and colder temperatures to arrive after shortwave and precipitation tracks through the area tonight.For Sunday, high pressure, drier air, and colder temperatures will dominate the weather for the day. This intrusion of drier air will help end ongoing precipitation before the wee hours Sunday. The high pressure and drier will allow for decreasing cloudiness during the day except for a some afternoon clouds that may develop during the afternoon hours. Highs will climb into the upper 20's for Sunday. As high pressure and mostly clear skies will dominate the weather Sunday night expect radiational cooling, enhanced by snowpack, and temps to fall rapidly into the upper single digits during the nighttime hours.
Strong 980mb low pressure system is still located directly north of region in Ontario. Temperatures are hovering in the upper 30's currently with the warmest temperatures located to the south and coldest to the northwest. The strong negative tilt of the 980mb is allowing the areas to the northwest to remain colder. Winds are relatively low right now as the low pressure is continuing track north and we are loosing daytime heating.
Saturday should remain mostly cloudy and dry during the day, expect afternoon highs to reach the mid 40s. A short wave will arrive Saturday night and increase our chances for snow Saturday night-Sunday. Right now any accumulation from looks to be minor and less than one-half inch. High pressure will move in behind the disturbance Sunday and this will keep temperatures colder than the last several days with highs temperatures expected to reach only the lower 30's.
A large trough looks to set up the weather pattern for next week. This will allow arctic air to spill south out of Canada for next week. This will keep afternoon highs below normal for all of next week. A relatively strong northwest flow will setup during the middle of next week along the periphery of this deep trough. This may heighten our chances for snow during the week as Alberta Clippers could develop along this boundary. Right now, will only mention the possibility of this and leave it out of the forecast for the time being.
A deepening, strengthening low pressure system will move out plains Thursday and track northward through the western Great Lakes during the day Thursday. The NAM, GFS, and ECMWF are all in fairly good agreement over the track of the low pressure tomorrow. With that being said, a warm front will move the area tomorrow morning and produce a chance for scattered showers and a few thunderstorms after 6am tomorrow. With a strong low level jet in place tomorrow, a strong warm air advection will occur before the cold front arrives Thursday night. This warm air advection will allow for unseasonably warm temperatures to overspread the area with highs in thee upper 50's to low 60's by the late afternoon. The approaching cold front and unseasonably warm temperatures is expected to trigger a squall line of thunderstorms during the late afternoon and early evening hours Thursday. A few of these storms may be severe with damaging wind gust being the primary threat. The cold front will sweep through behind the squall line and this will be followed by strong gusty winds. Winds gusts may exceed 50mph at times Thursday evening. Thinking that flooding will also be concern Thursday as the rate of snow melt will increase due to warmer temperatures and rain. Rainfall totals may approach 1" by the time system exits late Thursday.
Friday should remain dry and breezy. Highs may reach the lower 40's. A few disturbances this weekend will bring a chance for a few snow showers followed by colder than normal temperatures again for next week.
A cold front will move across the area later on tonight. There is little to no moisture with this system and will not begin to form showers until it's well south and east of the Lafayette area. However, a potentially strong storm system will move our way on Thursday. A warm front will move into area in the early morning hours on Thursday, bringing in warm moist gulf air from the south with temperatures possibly in the mid 50's, this will also give us the threat of severe thunderstorms. The best threat for severe weather will be in the late afternoon to early evening. Strong winds associated with a squall line is a good possibility. With the combination of warm temperatures, rain and melting snow pack, there is a good possibility of flooding in the area. The Cold front with this storm system should pass the area in the evening hours on Thursday and cold, drier will follow behind it.
Snow is making its into our area with some falling flakes already being seen. Accumulation between 2-4 inches of snow is predicted as we head into the evening hours. With the warm air aloft, we will be able to see a sleet, freezing rain, and a snow mix but it is not expected to last overnight. It is also possible we hear some thunder and see some lightning. As we head into tomorrow we are looking at temperatures approaching the 40s and we will start to see the snow melt.
The high over Indiana will move out of the area over night, allowing for a low to move in on Monday bringing a wintry mix of freezing rain and snow in late afternoon to the evening. With the low moving out of the area, a high will come in and sit over Indiana bringing dryer air Tuesday afternoon through Thursday morning, keeping the temperatures warmer. Towards the end of the week another low pressure system will move through, bringing precipitation.
Looking at a surface analysis, we can see a surface low pressure system to our Northwest with an associated shortwave aloft at 500mb. This puts us in the warm sector of the system, meaning that a high of 30 today is certainly not out of the question. Note the current progression of this low is on a direct collision course with the nor'easter currently forming along the southern Atlantic coast.
Current radar analysis also shows weak returns of 15dBz over Illinois moving our direction. Not too worried about current forecast as surface stations not reporting any precip on the ground. However, we currently are not mentioning any precip and I think we are under forecasting cloud cover with current partly cloudy forecast.
For tomorrow (Friday) into this weekend, we get a short blast of cold air from a decent surface high (about 1020mb) before a weak clipper system moves in late Saturday (00z-03z Sunday). GFS seems to be the outlier here as it takes the surface mesolow further north than all the NAM, EURO, RPM 12km runs. At this point, guidance supports better chance of snow rather than rain as 700mb-surface temps look to be below freezing.
Long range guidance (next Monday – Thursday) continues to support upper level flow returning to a more zonal pattern with few short wave systems progressing through. This should allow for some increased surface warming next week! WOO! Quick note, EURO and GFS both hint at a big disturbance rolling in late next week (images attached). Positioning is still way off, I just enjoying dreaming. Will continue to analyze next runs.