June 17 - 0200 UTC

FORECASTER: Hilary Smith

SYNOPTIC OVERVIEW
A high pressure system has moved out of the SPADE region into central AB. There is low pressure located at the borders of YK/NWT/BC with a trough going down into central Idaho. According to ECCC weather briefings, conditions will be unsettled tomorrow which could lead to showers or thunderstorms, which is reinforced by the upper low moving west across BC. An isolated severe storm that could bring 2-3 cm hail is predicted in the south-central foothills. 

NIPIKA
The GEM 2.5 km (1800 UTC) model run is showing 1.1 mm of liquid precipitation tomorrow between 2300 UTC June 17 and 0100 UTC June 18 with temperature highs in the mid-twenties. CAPE values will be mostly <1000 J/kg, with very light winds predominantly from the south and west. The HRRR (2300 UTC) model run is showing no precipitation tomorrow morning, and the RAP (2300 UTC) is showing only trace precipitation early tomorrow morning. The NAM (1800 UTC) model run is showing trace precipitation tomorrow morning. All models are showing CAPE values <1000 J/kg. The GEM 25 km (1200 UTC) model run is showing 0.3 mm of liquid precipitation from 1800 UTC to 2100 UTC tomorrow. The long term forecast suggests that substantial precipitation will begin at 1200 UTC June 18 and continue for a few days, with the possibility of solid precipitation on Thursday afternoon and overnight.

STORM LODGE
​The GEM 2.5 km (1800 UTC) model run is showing 9.4 mm  of liquid precipitation tomorrow from 1800 UTC to 2000 UTC and 0.5 mm from 0200 UTC to 0300 UTC June 18 with temperature highs in the high-teens. CAPE values will be >1500 J/kg tomorrow afternoon, with light variable winds. The high CAPE values coincide with the high amounts of precipitation so it is likely that this could be due to a thunderstorm tomorrow afternoon. The HRRR (0000 UTC June 17) is showing no precipitation tomorrow, and the RAP (2300 UTC) model run is showing trace precipitation  late tomorrow morning. The NAM (1800 UTC) model run is showing trace precipitation tomorrow throughout the day. CAPE values are <1000 J/kg in all models. The GEM 25 km (1200 UTC) model run is showing 0.4 mm of liquid precipitation from 1200 UTC to 1500 UTC Tuesday. The long term forecast suggests that substantial precipitation will begin at 0600 UTC June 19 and continue for a few days, with the possibility of solid precipitation on Wednesday afternoon.

FORTRESS
The GEM 2.5 km (1800 UTC) model run is showing 3.1 mm of liquid precipitation tomorrow, with the majority occurring from 1700 UTC June 17 to 0200 UTC June 18. Temperature highs are expected to be in the mid-teens. CAPE values will reach ~1000 J/kg but will be < 1000 J/kg for the majority of the day, with predominantly light SSW winds. The HRRR (2300 UTC) model run is showing no precipitation tomorrow morning, and the RAP (2300 UTC) is showing only trace trace precipitation tomorrow morning and early afternoon. The NAM (1800 UTC) model run is showing 4.7 mm of liquid precipitation tomorrow afternoon and early evening with the possibility of thunderstorms. All models are showing CAPE values <1000 J/kg. The GEM 25 km (1200 UTC) model run is showing 0.5 mm of liquid precipitation from 1800 UTC to 2100 UTC tomorrow. The long term forecast suggests that substantial precipitation will begin at 1800 UTC June 18 and continue for a few days, with the possibility of solid precipitation on Thursday afternoon.