Flymaster Open 2026 Weather Forecast July 13th

 

Synoptic Overview

Yesterday's atmospheric disturbance crossed our region from the west, bringing frontal activity to Kruševo in two distinct phases: the first around 12:00 LT and a secondary wave around 16:00 LT. Residual unstable air from Sunday remains in the atmosphere. Consequently, Monday's cloud development will mirror Sunday's patterns, causing the soaring window to operate in two separate development cycles.
Cloud Development
Early morning cumulus will develop over the ridges, initiating from the west. These clouds will rapidly expand during a first cycle, leading to horizontal overdevelopment in the northwest and northeast areas. The first soaring cycle will peak shortly after 12:00 LT, followed by a period of shading and suppressed lift. A secondary thermal cycle will then follow, peaking after 16:00 LT.
Convective activity
Cloud streets are forecasted along the North-South axes of both Kruševo and Prilep. A distinct convergence line will establish over the center of the valley, extending down to Bitola. This convergence is expected to maximize lift at approximately 15:30 LT. Overall, Monday offers a wider thermal window than Sunday's slow-developing airmass, though it remains divided into two distinct operating periods.
Wind Profile & Temperature Inversions
The strong winds observed on Sunday remained isolated at higher altitudes. On Monday, the upper-level flow will shift northerly but will remain away from the surface due to two inversion levels located at 1,800m and 3,500m ASL.
  • Surface to 1,800m: Surface winds will blow from the NE at 10 km/h, gradually  increasing to 20 km/h near the 1,800m inversion layer with some turbulence especially in the lee side of Cu.
  • Above 3,500m: Winds will shift NNW and exceed 35 km/h.
Thermal Strength & Lift Quality
Mechanical turbulence is anticipated near the inversion layers at 1,700m and 3,400m. Thermal updrafts will initially be capped at 1,800m. During the secondary afternoon cycle, cloud base and thermal heights may lift up to 2,800m+. While the initial morning cycle will give relatively weak lift, the second afternoon cycle seems to offer significantly improved conditions, featuring thermal strengths of up to 4 m/s and highly active valley convergence lines peaking after 15:30 LT.

More Details

Barometric pressure: climbs up 3mb from the previous day assuming stronger Inversion which may block high North Winds to reach lower.

Temperatures: 18-29 (DT=11 C) - Cooler day with good temperature contrast close to the ground and thermal triggering

Dewpoint: 9 C  that later in the day could increase cloudbase at 3.000m

Humidity low: 22%, similar to Sunday, thermals with high air density

Humidity Boundary layer: 60%, meaning high humidity at high altitude, mixed air and turbulence at inversions (1800m)

Cloud base: Initially 2400m to the west, later climbs up to 3000m during the 2nd cycle.

Cloud tops: +600m at peak, but blocked by 3500m inversion and high north continental winds

Cloud types: Cu, overdevelopment west and east, convergence cloud in the valley from North to South

Cloud Coverage: 60% to N later 80%, at Bitola 20% later 40%

Inversion levels: 1800m, 3500m 

Energy flow: slow thermal evolution to the west, better to the NE and Prilep area

Average Thermal expected at 3m/s at 2nd cycle

Thermal tops: 2.850m afte 15.30 

Thermals at Altitude: +2m/s at 1000m, +3,5m/s at 1500m, +4,5m/s at 2000m Stronger higher

Ideal Thermal Zone: 1300m-2000m at peak of Conditions

WINDS at 14:00

Wind Gust at Surface: 30kph at take of  15kph valley surface gusts

0m: NE 10kph

600m: NE 14kph

1200m: NNE 16kph

1800m: N 15-22 above west mountains

2400m NW 25kph

3000m NW 25kph

3600m: NW 35+ kph

Conditions start Organizing: 11.00 at first cycle

Conditions decline after: 16.00

Conditions Best Period: 11:00-1600h with a middle gap at overdevelopment

Conditions Peak time: at 12.00h and at 16.00h

Duration of Conditions: 3h

Calculated XC Speed: 32 kph

Expected Task Distance 80-90 km

Convergence lines: expected in the middle of the valley from North to South peak at 15.30h

Rain Forecast: N/A

Skew-T at 14.00h







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